Laminates for spouted packaging bags and packaging bags

Abstract

To provide a laminate that enables the production of spouted packaging bags that possess sufficient strength and heat resistance, as well as excellent recyclability. [Solution] The laminate for spouted packaging bags of the present invention comprises a base material and a sealant layer, wherein the base material and the sealant layer are made of the same material, the base material is subjected to at least one of stretching and electron beam irradiation, and the same material is polyethylene or polypropylene.

Description

[Technical Field]

[0001] The present invention relates to a laminate used in the manufacture of a spouted packaging bag. The present invention also relates to a packaging bag composed of the laminate.

[0002] Traditionally, resin films made from resin materials have been used as the material for packaging bags. For example, resin films made from polyolefins are widely used for packaging bags because they have moderate flexibility and transparency, as well as excellent heat-sealing properties.

[0003] Typically, resin films made from polyolefins are inferior in terms of strength and heat resistance, and therefore cannot be used as a base material for constructing packaging bags, etc. Instead, they are used in combination with resin films made from polyester, polyamide, etc. Therefore, typical packaging bags are made of a laminate in which the base material and the sealant layer are made of different resin materials (for example, Patent Document 1).

[0004] In recent years, with the growing demand for a circular economy, there is a growing need for high recyclability in packaging bags and other materials. However, as mentioned above, conventional packaging bags are composed of different types of resin materials, making it difficult to separate them, and as a result, they are not currently recycled. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2009-202519 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] The inventors have found that by subjecting a polyethylene film or a polypropylene film to at least one of stretching treatment and electron beam irradiation treatment, the strength and heat resistance thereof can be remarkably improved, and it can be used as a base material included in a laminate used for producing a packaging bag or the like. And, similar to the base material, it has been found that by providing a sealant layer composed of polyolefin, the recyclability of the laminate can be remarkably enhanced.

[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 enables the production of a spouted packaging bag having sufficient strength, heat resistance, and excellent recyclability.

[0008] Another problem to be solved by the present invention is to provide a spouted packaging bag composed of the laminate.

Means for Solving the Problems

[0009] The laminate for a spouted packaging bag of the present invention includes a base material and a sealant layer. The base material and the sealant layer are composed of the same material. At least one of stretching treatment and electron beam irradiation treatment has been performed on the base material. It is characterized in that the same material is polyethylene or polypropylene.

[0010] The spouted packaging bag of the present invention includes a storage part and a spout. The storage part is composed of the above laminate. It is characterized in that the spout is composed of the material constituting the sealant layer of the laminate.

[0011] In one embodiment, the spouted packaging bag of the present invention includes gusset parts on both side parts.

[0012] In one embodiment, the spout includes a cylindrical part, a flange part, and a welded part.

[0013] In one embodiment, the welding part included in the spout has a flat surface.

Advantages of the Invention

[0014] According to the present invention, it is possible to provide a laminate that enables the production of a packaging bag or the like having sufficient strength, heat resistance, and excellent recyclability.

Brief Description of the Drawings

[0015] [Figure 1] It is a schematic cross-sectional view showing one embodiment of the laminate of the present invention. [Figure 2] It is a schematic cross-sectional view showing one embodiment of the laminate of the present invention. [Figure 3] It is a schematic cross-sectional view showing one embodiment of the laminate of the present invention. [Figure 4] It is a schematic cross-sectional view showing one embodiment of the laminate of the present invention. [Figure 5] It is a schematic cross-sectional view showing one embodiment of the laminate of the present invention. [Figure 6] It is a schematic cross-sectional view showing one embodiment of the laminate of the present invention. [Figure 7] It is a front view showing one embodiment of a packaging bag produced using the laminate of the present invention. [Figure 8] It is a perspective view showing one embodiment of a packaging bag produced using the laminate of the present invention. [Figure 9] It is a perspective view showing one embodiment of the spout included in the packaging bag of the present invention. [Figure 10] It is a side view showing one embodiment of the spout included in the packaging bag of the present invention.

Embodiments for Carrying Out the Invention

[0016] (Laminate) As shown in FIG. 1, the laminate 10 of the present invention is characterized by including a base material 11 and a sealant layer 12. In one embodiment, the laminate 10 includes a light-shielding printed layer 13 between the substrate 11 and the sealant layer 12, as shown in Figure 2. In another embodiment, the sealant layer 12 of the laminate 10 includes a light-shielding layer 14, as shown in Figure 3. In this embodiment, the sealant layer 12 may also include a laminate layer 15 and a heat-seal layer 16. In one embodiment, as shown in Figure 4, the laminate 10 includes a barrier coat layer 17 between the substrate 11 and the sealant layer 12. In one embodiment, the laminate 10 comprises a substrate 11, a barrier coat layer 17, a light-shielding printing layer 13, and a sealant layer 12, as shown in Figure 5. Furthermore, in one embodiment, the laminate 10 comprises a substrate, a barrier coat layer 17, and a sealant layer 12 having a light-shielding layer 14, as shown in Figure 6.

[0017] In one embodiment, the laminate of the present invention may include a vapor-deposited film between the substrate and the sealant layer, between the substrate and the barrier coat layer, between the barrier coat layer and the sealant layer, or between the barrier coat layer and the light-shielding printing layer, etc. (not shown).

[0018] Furthermore, the laminate of the present invention may include adhesive layers between any of the layers (not shown). Furthermore, the laminate of the present invention may include an intermediate layer between the substrate and the sealant layer (not shown).

[0019] In this invention, the base material and the sealant layer are made of the same material, namely polyethylene or polypropylene, which improves the recyclability of the laminate.

[0020] (base material) The substrate constituting the laminate of the present invention is made of polyethylene or polypropylene and is characterized by being subjected to at least one of stretching and electron beam irradiation. By applying this stretching and electron beam irradiation treatment, the heat resistance and strength of the substrate can be significantly improved, and the physical properties required for an outer layer of packaging bags and the like can be satisfied. Furthermore, if the substrate has been subjected to electron beam irradiation treatment, the substrate is positioned such that the electron beam-irradiated surface of the substrate becomes the outermost surface of the laminate.

[0021] As polyethylene, high-density polyethylene, medium-density polyethylene, low-density polyethylene, linear low-density polyethylene, and ultra-low-density polyethylene can be used. Among these, high-density polyethylene and medium-density polyethylene are preferred from the viewpoint of the strength and heat resistance of the base material, and medium-density polyethylene is more preferred from the viewpoint of stretchability.

[0022] In this invention, high-density polyethylene has a density of 0.945 g / cm³. 3 The above polyethylenes can be used, and as medium-density polyethylene, the density is 0.925 g / cm³. 3 More than 0.945g / cm 3 Polyethylene with a density of less than 0.900 g / cm³ can be used, and low-density polyethylene has a density of 0.900 g / cm³. 3 More than 0.925g / cm 3 Polyethylene with a density of less than 0.900 g / cm³ can be used, and as linear low-density polyethylene, a density of 0.900 g / cm³ can be used. 3 More than 0.925g / cm 3 Polyethylene with a density of less than 0.900 g / cm³ can be used, and ultra-low density polyethylene has a density of 0.900 g / cm³. 3 Polyethylene less than a certain amount can be used.

[0023] Furthermore, within the limits that do not impair the properties of the present invention, copolymers of ethylene and other monomers may be used as polyethylene. Examples of ethylene copolymers include copolymers consisting of ethylene and α-olefins having 3 to 20 carbon atoms. Examples of 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 limits that do not impair the objectives of the present invention, copolymers with vinyl acetate or acrylic acid esters may be used.

[0024] Furthermore, in the present invention, it is preferable that the base material contains biomass-derived polyethylene. Biomass-derived polyethylene is obtained by using biomass-derived ethylene as a raw material instead of ethylene obtained from fossil fuels. Since such biomass-derived polyethylene is a carbon-neutral material, it can reduce the environmental burden of producing the laminate. Such biomass-derived polyethylene can be produced, for example, by a method described in Japanese Patent Application Publication No. 2013-177531. Alternatively, commercially available biomass-derived polyethylene (for example, Green PE sold by Braschem) may be used.

[0025] In addition, recycled polyethylene can be used through mechanical recycling. Mechanical recycling generally involves crushing collected polyethylene film, washing it with alkali to remove dirt and foreign matter from the film surface, and then drying it under high temperature and reduced pressure for a certain period of time to disperse any contaminants remaining inside the film, thereby decontaminating it and removing the dirt from the polyethylene film, returning it to polyethylene once again.

[0026] When contents are placed in a packaging bag made from the laminate of the present invention and subjected to retort processing, it is preferable that the base material and sealant layer be made of polypropylene from the viewpoint of suitability for retort processing. Polypropylene may be a homopolymer, a random copolymer, or a block copolymer. Polypropylene homopolymer is a polymer consisting solely of propylene; polypropylene random copolymer is a random copolymer of propylene and other α-olefins other than propylene (e.g., ethylene, butene-1, 4-methyl-1-pentene, etc.); and polypropylene block copolymer is a copolymer having polymer blocks made of propylene and polymer blocks made of the aforementioned α-olefins other than propylene. Among these polypropylenes, it is preferable to use homopolymers or random copolymers from the viewpoint of improving the transparency of the substrate and improving the visibility of the image when it is formed on the adhesive layer surface of the substrate. When rigidity and heat resistance of the packaging bag are important, homopolymers can be used, and when impact resistance and other properties are important, random copolymers can be used.

[0027] Additionally, it is possible to use polypropylene derived from biomass or polypropylene recycled through mechanical recycling.

[0028] The base material may contain additives to the extent that they do not impair the properties of the present invention, such as crosslinking agents, antioxidants, antiblocking agents, lubricants, ultraviolet absorbers, light stabilizers, containment agents, reinforcing agents, antistatic agents, pigments, and modifying resins.

[0029] The base material may have a single-layer structure or a multi-layer structure. In one embodiment, the substrate has a multilayer structure comprising a layer made of high-density polyethylene (hereinafter referred to as the high-density polyethylene layer), a layer made of medium-density polyethylene (hereinafter referred to as the medium-density polyethylene layer), and a layer made of high-density polyethylene (hereinafter referred to as the high-density polyethylene layer). This configuration allows for further improvement of the strength and heat resistance of the substrate. It also prevents curling in the substrate and improves its stretchability. In this case, it is preferable that the thickness of the high-density polyethylene layer is 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 substrate can be further improved. Furthermore, 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 stretchability of the substrate can be further improved.

[0030] In one embodiment, the substrate comprises 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 (collectively referred to as a low-density polyethylene layer in this paragraph for simplification), a medium-density polyethylene layer, and a high-density polyethylene layer. This configuration improves the stretchability of the substrate, enhances its strength and heat resistance, prevents curling, and improves the production efficiency of the substrate. In this case, it is preferable that the thickness of the high-density polyethylene layer is 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 substrate can be improved. Furthermore, 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 stretchability of the substrate can be improved. Furthermore, it is preferable that the thickness of the high-density polyethylene layer is the same as or greater 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 of the substrate can be improved. Furthermore, 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. The thickness of each high-density polyethylene layer is preferably 1 μm or more and 20 μm or less, and more preferably 2 μm or more and 10 μm or less. By making the thickness of the high-density polyethylene layer 1 μm or more, the strength and heat resistance of the laminate of the present invention can be further improved. Furthermore, by making the thickness of the high-density polyethylene layer 20 μm or less, the processability of the laminate of the present invention can be further improved. The thickness of the medium-density polyethylene layer is preferably 1 μm or more and 30 μm or less, and more preferably 5 μm or more and 20 μm or less. By making the thickness of the medium-density polyethylene layer 1 μm or more, the stretchability of the film can be further improved. Furthermore, by making the thickness of the medium-density polyethylene layer 30 μm or less, the processability of the laminate of the present invention can be further improved. The thickness of the low-density polyethylene layer is preferably 1 μm or more and 10 μm or less, and more preferably 2 μm or more and 5 μm or less. By making the thickness of the low-density polyethylene layer 1 μm or more, the adhesion between the high-density polyethylene layer and the medium-density polyethylene layer can be further improved. Furthermore, by making the thickness of the low-density polyethylene layer 5 μm or less, the processability of the laminate of the present invention can be further improved. In one embodiment, a substrate with such a configuration can be produced, for example, by an inflation method. Specifically, it can be manufactured by co-extruding a high-density polyethylene layer, a medium-density polyethylene layer, and a low-density polyethylene layer, a linear low-density polyethylene layer, or an ultra-low-density polyethylene layer into a tube shape from the outside, and then pressing the opposing low-density polyethylene layers, linear low-density polyethylene layers, or ultra-low-density polyethylene layers together using a rubber roll or the like. By manufacturing in this manner, the number of defective products in production can be significantly reduced, ultimately improving production efficiency. Furthermore, the inflation film-forming machine can also perform stretching, which further improves production efficiency.

[0031] In one embodiment, the film can be composed of seven layers, from the outside in: a high-density polyethylene layer, a blended resin layer of high-density polyethylene and medium-density polyethylene, a medium-density polyethylene layer, a low-density polyethylene layer, a linear low-density polyethylene layer, or an ultra-low-density polyethylene layer (collectively referred to as a low-density polyethylene layer in this paragraph for simplification), a medium-density polyethylene layer, a blended resin layer of high-density polyethylene and medium-density polyethylene, and a high-density polyethylene layer. This configuration improves the adhesion between the high-density polyethylene layer and the medium-density polyethylene layer. Furthermore, it improves the processability of the laminate according to the present invention. The thickness of each high-density polyethylene layer is preferably 1 μm or more and 20 μm or less, and more preferably 2 μm or more and 10 μm or less. By making the thickness of the high-density polyethylene layer 1 μm or more, the strength and heat resistance of the laminate of the present invention can be further improved. Furthermore, by making the thickness of the high-density polyethylene layer 20 μm or less, the processability of the laminate of the present invention can be further improved. The thickness of each high-density polyethylene and medium-density polyethylene blend resin layer is preferably 1 μm or more and 20 μm or less, and more preferably 2 μm or more and 10 μm or less. This improves the adhesion between the high-density polyethylene layer and the medium-density polyethylene layer. Furthermore, it improves the processability of the laminate of the present invention. The thickness of the medium-density polyethylene layer is preferably 1 μm or more and 30 μm or less, and more preferably 5 μm or more and 20 μm or less. By making the thickness of the medium-density polyethylene layer 1 μm or more, the stretchability of the film can be further improved. Furthermore, by making the thickness of the medium-density polyethylene layer 30 μm or less, the processability of the laminate of the present invention can be further improved. The thickness of the low-density polyethylene layer is preferably 1 μm or more and 10 μm or less, and more preferably 2 μm or more and 5 μm or less. By making the thickness of the low-density polyethylene layer 1 μm or more, the adhesion between the high-density polyethylene layer and the medium-density polyethylene layer can be further improved. Furthermore, by making the thickness of the low-density polyethylene layer 5 μm or less, the processability of the laminate of the present invention can be further improved. In one embodiment, a stretched polyethylene film having such a configuration can be produced by the inflation method described above. By manufacturing in this manner, the number of defective products in production can be significantly reduced, ultimately improving production efficiency. Furthermore, the inflation film-forming machine can also perform stretching, which further improves production efficiency.

[0032] If the base material has been subjected to a stretching process, the stretching may be uniaxial or biaxial. The stretching ratio in the longitudinal direction (MD) of the substrate is preferably 2 times or more and 10 times or less, and preferably 3 times or more and 7 times or less. By increasing the stretching ratio in the longitudinal direction (MD) of the substrate to 2 times or more, the strength and heat resistance of the substrate can be improved. Furthermore, the printability of the substrate can be improved. In addition, the transparency of the substrate can be improved. On the other hand, there is no particular upper limit to the stretching ratio in the longitudinal direction (MD) of the substrate, but from the viewpoint of the breaking limit of the substrate, it is preferable to keep it at 10 times or less. Furthermore, the stretching ratio in the transverse direction (TD) of the substrate is preferably 2 times or more and 10 times or less, and preferably 3 times or more and 7 times or less. By increasing the transverse (TD) stretching ratio of the substrate to 2 times or more, the strength and heat resistance of the substrate can be improved. Furthermore, the printability of the substrate can be improved. In addition, the transparency of the substrate can be improved. On the other hand, there is no particular upper limit to the transverse (TD) stretching ratio of the substrate, but from the viewpoint of the substrate's breaking limit, it is preferable to keep it at 10 times or less.

[0033] When a substrate is subjected to electron beam irradiation, the crosslinking density of the polyethylene or polypropylene contained in the substrate is improved by the electron beam irradiation, significantly improving the heat resistance and strength of the substrate. This embodiment is particularly suitable when the substrate is made of polyethylene.

[0034] The substrate may be one in which the crosslinking density of polyethylene on one side has been improved by electron beam irradiation, or it may be one in which the crosslinking density of polyolefins throughout the substrate has been improved. Furthermore, if the substrate has a multilayer structure, it is sufficient that the crosslinking density of the polyethylene in the outermost layer is improved by electron beam irradiation. From the viewpoint of strength and heat resistance, it is preferable that the overall crosslinking density of polyethylene is improved by electron beam irradiation.

[0035] Conventional and known devices can be used for electron beam irradiation of substrates. For example, curtain-type electron beam irradiation devices (LB1023, manufactured by I-Electron Beam Co., Ltd.), line-type low-energy electron beam irradiation devices (EB-ENGINE, manufactured by Hamamatsu Photonics K.K.), and drum-roll type electron beam irradiation devices (EZ-CURE, manufactured by I-Electron Beam Co., Ltd.) can be suitably used.

[0036] The dose of electron beam irradiated onto the substrate is preferably in the range of 10 kGy to 2000 kGy, more preferably in the range of 20 kGy to 1000 kGy, and even more preferably in the range of 150 kGy to 500 kGy. Furthermore, the acceleration voltage of the electron beam is preferably in the range of 30kV to 300kV, more preferably in the range of 50kV to 300kV, and even more preferably in the range of 50kV to 250kV. Furthermore, the electron beam irradiation energy is preferably in the range of 20 keV to 750 keV, more preferably in the range of 25 keV to 500 keV, even more preferably in the range of 30 keV to 400 keV, and particularly preferably in the range of 20 keV to 200 keV.

[0037] The oxygen concentration inside the electron beam irradiation apparatus is preferably 500 ppm or less, and more preferably 100 ppm or less. By performing electron beam irradiation under these conditions, the generation of ozone can be suppressed, and the deactivation of radicals generated by electron beam irradiation by oxygen in the atmosphere can be suppressed. Such conditions can be achieved, for example, by creating an inert gas atmosphere (nitrogen, argon, etc.) inside the apparatus.

[0038] In one embodiment, electron beam irradiation can be performed simultaneously with cooling using a cooling drum or the like.

[0039] Furthermore, the substrate may be surface-treated. This can improve adhesion with adjacent layers. The surface treatment method is not particularly limited and includes 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. Alternatively, an anchor coat layer may be formed on the substrate surface using a conventionally known anchor coat agent.

[0040] The substrate may have a printed layer on its surface, and the image formed on the printed layer is not particularly limited and may represent characters, patterns, symbols, or combinations thereof. From an environmental perspective, it is preferable to use biomass-derived inks for forming the printed layer on the substrate. The method for forming the printed layer is not particularly limited and can be described as conventionally known printing methods such as gravure printing, offset printing, and flexographic printing. Among these, flexographic printing is preferred from the viewpoint of environmental impact.

[0041] The thickness of the base material is preferably 10 μm or more and 50 μm or less, and more preferably 15 μm or more and 30 μm or less. By making the thickness of the base material 10 μm or more, its strength and heat resistance can be further improved. Furthermore, by making the thickness of the base material 50 μm or less, the processability of the laminate comprising the base material can be improved.

[0042] The base material can be produced by forming a resin film from a resin composition containing at least polyethylene or polypropylene using a T-die method or inflation method, and then stretching and / or irradiating it with an electron beam. By forming the film using the inflation method, the stretching of the resin film can be performed simultaneously. When both stretching and electron beam irradiation of a resin film are performed, either can be done first, but for reasons of suitability for stretching, it is preferable to perform stretching first.

[0043] When preparing a substrate using the T-die method, the MFR of the resin composition is preferably 3 g / 10 min or more and 20 g / 10 min or less. By setting the MFR of the resin composition to 3g / 10min or more, the processability of the substrate can be improved. Furthermore, by setting the MFR of the resin composition to 20g / 10min or less, it is possible to prevent the substrate from breaking during stretching.

[0044] When preparing a substrate by the inflation method, the MFR of the resin composition is preferably 0.5 g / 10 min or more and 5 g / 10 min or less. By setting the MFR of the resin composition to 0.5 g / 10 min or higher, the processability of the substrate can be improved. Furthermore, by setting the MFR of the resin composition to 5 g / 10 min or lower, the film-forming properties can be improved.

[0045] (Sealant layer) In one embodiment, the sealant layer is characterized by being made of the same material as the substrate, namely polyethylene or polypropylene. This improves the recyclability of the laminate.

[0046] From the viewpoint of heat sealability, the sealant layer preferably contains polyethylene, and more preferably contains low-density polyethylene, linear low-density polyethylene, and ultra-low-density polyethylene. Furthermore, in order to improve the tearability of packaging bags made using the laminate of the present invention, it is preferable that the sealant layer contains low-density polyethylene. Furthermore, in order to improve the drop strength of the packaging bag made using the laminate of the present invention, the sealant layer preferably contains linear low-density polyethylene. Examples of linear low-density polyethylene include C-4LLDPE and C-6LLDPE. From the viewpoint of balancing tear strength and impact strength, C-4LLDPE is preferred, and from the viewpoint of improving drop strength, C-6LLDPE is preferred. The sealant layer preferably contains both C-4LLDPE and C-6LLDPE.

[0047] When the sealant layer contains low-density polyethylene and linear low-density polyethylene, the content of low-density polyethylene is preferably 5% by mass or more and 20% by mass or less, and more preferably 9% by mass or more and 15% by mass or less. By setting the low-density polyethylene content to 5% by mass or more, the tear resistance of the packaging bag made using the laminate of the present invention can be further improved. By setting the low-density polyethylene content to 20% by mass or less, the drop strength of the packaging bag made using the laminate of the present invention can be maintained. Furthermore, the linear low-density polyethylene content is preferably 65% ​​by mass or more and 90% by mass or less, and more preferably 70% by mass or more and 80% by mass or less. By setting the linear low-density polyethylene content to 65% by mass or more, the drop strength of the packaging bag made using the laminate of the present invention can be further improved. By setting the linear low-density polyethylene content to 90% by mass or less, additives such as slip agents and anti-blocking agents can be added, and a film with excellent processability can be obtained.

[0048] The sealant layer may also contain the above-mentioned biomass-derived polyethylene, mechanically recycled polyethylene, polypropylene, etc.

[0049] The sealant layer may contain the above-mentioned additives, to the extent that it does not impair the properties of the present invention.

[0050] In one embodiment, the sealant layer comprises a light-shielding layer containing a light-shielding pigment, together with polyethylene or polypropylene. This improves the storage stability of the contents contained in the packaging bag made from the laminate of the present invention. The light-shielding layer may have a single-layer structure or a multi-layer structure.

[0051] Examples of light-shielding pigments include carbon black, acetylene black, lamp black, black soot, iron black, aniline black, titanium dioxide, barium oxide, calcium carbonate, aluminum hydroxide, and zinc oxide. By using these light-shielding pigments, the contents contained in the packaging bag made from the laminate of the present invention can be concealed. Furthermore, by using a white pigment such as titanium dioxide, the sealant layer can be given the function of a background layer, thereby improving the visibility of the image formed on the substrate.

[0052] The content of the light-shielding pigment in the light-shielding layer is preferably 2% by mass or more and 25% by mass or less, and more preferably 4% by mass or more and 23% by mass or less. This makes it possible to further improve the storage stability of the contents contained in the packaging bag made from the laminate of the present invention while maintaining the heat-sealing properties of the heat-seal layer.

[0053] The thickness of the light-shielding layer is preferably 10 μm to 60 μm, and more preferably 15 μm to 40 μm. This further improves the storage stability of the contents contained in the packaging bag made from the laminate of the present invention.

[0054] The sealant layer may have a single-layer structure or a multi-layer structure. For example, it may consist of a substrate, a laminate layer to be laminated, an intermediate layer, and a heat-seal layer. If the sealant layer includes a light-shielding layer, it is preferable to provide it as an intermediate layer. This improves the light-shielding properties without reducing the heat-sealability and lamination properties with the substrate.

[0055] In one embodiment, the intermediate layer of the multilayer sealant layer includes at least one of medium-density polyethylene and high-density polyethylene. This makes it possible to further improve the strength of the laminate of the present invention. Specific examples of intermediate layers containing at least one of medium-density polyethylene and high-density polyethylene include a layer containing at least one of low-density polyethylene, linear low-density polyethylene, and ultra-low-density polyethylene, a layer containing at least one of medium-density polyethylene and high-density polyethylene, and a layer containing at least one of low-density polyethylene, linear low-density polyethylene, and ultra-low-density polyethylene. By adopting the above configuration, it is possible to further improve the suitability for bag making and strength of the laminate of the present invention while maintaining heat sealability.

[0056] The thickness of the sealant layer is preferably 40 μm to 150 μm, and more preferably 60 μm to 100 μm. This further improves the heat sealability of the laminate of the present invention.

[0057] (Light-shielding printing layer) In one embodiment, the laminate of the present invention comprises a light-shielding printing layer between the substrate and the sealant layer. This improves the storage stability of the contents contained in the packaging bag made from the laminate of the present invention. Furthermore, it allows for the concealment of the contents contained in the packaging bag made from the laminate of the present invention.

[0058] The light-blocking printing layer contains light-blocking ink, and while the color is not particularly limited, it is preferable to change it as appropriate depending on the contents, such as black, white, gray, orange, red, yellow, silver, and brown. If the contents contain vitamins, they are susceptible to degradation by light with wavelengths below 500 nm; therefore, it is preferable to use an ink that absorbs light of these wavelengths, such as orange ink. Alternatively, aluminum-containing inks or UV-curing inks can be used as light-shielding inks. The white light-shielding ink layer functions as a background layer, improving the visibility of the image formed on the substrate.

[0059] Examples of light-blocking pigments that can be included in light-blocking inks include, but are not limited to, carbon black, acetylene black, lamp black, black soot, iron black, aniline black, titanium dioxide, and zinc oxide.

[0060] The light-shielding printing layer may have a multilayer structure, for example, a configuration comprising a white ink layer and a gray ink layer, a configuration comprising a white ink layer and a black ink layer, a configuration comprising a white ink layer, a yellow ink layer and a red ink layer, or a configuration comprising a white ink layer and a silver ink layer.

[0061] The thickness of the light-shielding printed layer is preferably 0.2 μm to 8 μm, and more preferably 0.5 μm to 6 μm. By setting the thickness of the light-shielding printed layer to 0.2 μm or more, the storage stability of the contents contained in the packaging bag made from the laminate of the present invention can be further improved. By setting the thickness of the light-shielding printed layer to 8 μm or less, a laminate with stable physical properties can be obtained without hindering adhesion with the sealant layer.

[0062] The method for forming the light-shielding printed layer is not particularly limited and can be described using conventionally known printing methods such as offset printing and flexographic printing. Among these, flexographic printing is preferred from the viewpoint of environmental impact.

[0063] (Barrier coat layer) The laminate of the present invention may include a barrier coat layer between the substrate and the sealant layer. This can improve the oxygen barrier and water vapor barrier properties of the laminate. When the laminate of the present invention includes a light-shielding printed layer, it is preferable to provide the barrier coat layer between the substrate and the light-shielding printed layer.

[0064] In one embodiment, the barrier coat layer is a gas barrier coating film containing at least one resin composition such as a hydrolyzate of a metal alkoxide or a hydrolytic condensate of a metal alkoxide obtained by polycondensing a mixture of a metal alkoxide and a water-soluble polymer by a sol-gel method in the presence of a sol-gel method catalyst, water, an organic solvent, and the like. When the laminate of the present invention includes a vapor deposition film composed of an inorganic oxide, by providing the barrier coat layer of this form adjacent to the vapor deposition film, generation of cracks in the vapor deposition film can be effectively prevented.

[0065] In one embodiment, the metal alkoxide is represented by the following general formula. R 1 n M(OR 2 ) m (However, in the formula, R 1 , R 2 each represent an organic group having 1 to 8 carbon atoms, M represents a metal atom, n represents an integer of 0 or more, m represents an integer of 1 or more, and n + m represents the valence of M.)

[0066] As the metal atom M, for example, silicon, zirconium, titanium, aluminum, and the like can be used. Also, as the organic groups represented by R 1 and R 2 , for example, alkyl groups such as methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, and i-butyl group can be mentioned.

[0067] Examples of the metal alkoxide satisfying the above general formula include tetramethoxysilane (Si(OCH3)4), tetraethoxysilane (Si(OC2H5)4), tetrapropoxysilane (Si(OC3H7)4), tetrabutoxysilane (Si(OC4H9)4), and the like.

[0068] Also, it is preferable to use a silane coupling agent together with the above metal alkoxide. As silane coupling agents, known organic reactive group-containing organoalkoxysilanes can be used, but organoalkoxysilanes having an epoxy group are particularly preferred. Examples of organoalkoxysilanes having an epoxy group include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane.

[0069] Two or more silane coupling agents may be used as described above, and it is preferable to use the silane coupling agent in an amount of about 1 to 20 parts by mass per 100 parts by mass of the total amount of the alkoxides.

[0070] As water-soluble polymers, polyvinyl alcohol and ethylene-vinyl alcohol copolymers are preferred, and from the viewpoint of oxygen barrier properties, water vapor barrier properties, water resistance and weather resistance, it is preferable to use these in combination.

[0071] The content of the water-soluble polymer in the gas barrier coating film is preferably 5 parts by mass or more and 500 parts by mass or less per 100 parts by mass of metal alkoxide. By setting the content of the water-soluble polymer in the gas barrier coating film to 5 parts by mass or more per 100 parts by mass of metal alkoxide, the oxygen barrier and water vapor barrier properties of the laminate can be further improved. Furthermore, by setting the content of the water-soluble polymer in the gas barrier coating film to 500 parts by mass or less per 100 parts by mass of metal alkoxide, the film-forming properties of the gas barrier coating film can be improved.

[0072] The thickness of the gas barrier coating film is preferably 0.01 μm to 100 μm, and more preferably 0.1 μm to 50 μm. This allows for improved oxygen barrier and water vapor barrier properties while maintaining recyclability. By setting the thickness of the gas barrier coating film to 0.01 μm or more, the oxygen barrier and water vapor barrier properties of the laminate can be improved. Furthermore, when it is provided adjacent to a vapor-deposited film composed of inorganic oxides, it can prevent the occurrence of cracks in the vapor-deposited film.

[0073] A gas barrier coating film can be formed by applying a composition containing the above-mentioned materials using conventionally known methods such as roll coating (including gravure roll coaters), spray coating, spin coating, dipping, brushing, barcode application, or applicator application, and then polycondensing the composition by a sol-gel method. Suitable catalysts for the sol-gel process include acids or amine compounds. Suitable amine compounds include tertiary amines that are substantially insoluble in water and soluble in organic solvents, such as N,N-dimethylbenzylamine, tripropylamine, tributylamine, and tripentylamine. Among these, N,N-dimethylbenzylamine is preferred. The sol-gel catalyst is preferably used in an amount of 0.01 parts by mass or more and 1.0 part by mass or less per 100 parts by mass of metal alkoxide, and more preferably in an amount of 0.03 parts by mass or more and 0.3 parts by mass or less. The catalytic effect of the sol-gel method catalyst can be improved by using 0.01 parts by mass or more per 100 parts by mass of metal alkoxide. Furthermore, by using 1.0 part by mass or less per 100 parts by mass of metal alkoxide, the thickness of the formed gas barrier coating film can be made uniform.

[0074] The above composition may further contain an acid. The acid is used as a catalyst for the sol-gel process, mainly as a catalyst for the hydrolysis of alkoxides and silane coupling agents. As acids, mineral acids such as sulfuric acid, hydrochloric acid, and nitric acid, as well as organic acids such as acetic acid and tartaric acid, can be used. The amount of acid used is preferably 0.001 moles or more and 0.05 moles or less relative to the total molar amount of the alkoxide and the alkoxide portion (e.g., silicate portion) of the silane coupling agent. By using an amount of acid equal to 0.001 moles or more relative to the total molar amount of the alkoxide component (e.g., silicate portion) of the alkoxide and silane coupling agent, the catalytic effect can be improved. Furthermore, by using an amount of acid equal to 0.05 moles or less relative to the total molar amount of the alkoxide component (e.g., silicate portion) of the alkoxide and silane coupling agent, the thickness of the formed gas barrier coating film can be made uniform.

[0075] Furthermore, the above composition preferably contains water in an amount of 0.1 moles to 100 moles, more preferably 0.8 moles to 2 moles, per mole of the total molar amount of alkoxide. By setting the water content to 0.1 moles or more per mole of total alkoxide, the oxygen barrier and water vapor barrier properties of the laminate of the present invention can be improved. Furthermore, by setting the water content to 100 moles or more per mole of total alkoxide, the hydrolysis reaction can be carried out rapidly.

[0076] Furthermore, the above composition may contain an organic solvent. Examples of organic solvents include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, and n-butanol.

[0077] The following describes one embodiment of a method for forming a gas barrier coating film. First, a composition is prepared by mixing a metal alkoxide, a water-soluble polymer, a sol-gel catalyst, water, an organic solvent, and, if necessary, a silane coupling agent. A polycondensation reaction gradually proceeds within this composition. Next, the composition is applied to the substrate using the conventionally known method described above and dried. This drying further promotes the polycondensation reaction between the alkoxide and the water-soluble polymer (and the silane coupling agent if the composition contains one), forming a layer of composite polymer. Finally, a gas barrier coating film can be formed by heating the composition at a temperature of 20 to 250°C, preferably 50 to 220°C, for 1 second to 10 minutes.

[0078] The barrier coat layer may have a printed layer formed on it. The method for forming the printed layer is as described above.

[0079] The barrier coating layer may contain the above-mentioned additives to the extent that they do not impair the properties of the present invention.

[0080] (Vaporized film) In one embodiment, the laminate of the present invention may include a vapor-deposited film between the substrate and the sealant layer, between the substrate and the barrier coat layer, between the barrier coat layer and the sealant layer, or between the barrier coat layer and the light-shielding printing layer. This improves the gas barrier properties of the laminate, specifically the oxygen barrier properties and water vapor barrier properties. Furthermore, it is possible to suppress the mass reduction of the contents contained in a packaging bag made using the laminate of the present invention.

[0081] Examples of vapor-deposited films include those composed of metals such as aluminum, as well as inorganic oxides such as aluminum oxide, silicon oxide, magnesium oxide, calcium oxide, zirconium oxide, titanium oxide, boron oxide, hafnium oxide, and barium oxide.

[0082] Furthermore, the thickness of the deposited film is preferably 1 nm to 150 nm, more preferably 5 nm to 60 nm, and even more preferably 10 nm to 40 nm. By making the thickness of the deposited film 1 nm or more, the oxygen barrier and water vapor barrier properties of the laminate can be further improved. Also, by making the thickness of the deposited film 150 nm or less, the occurrence of cracks in the deposited film can be prevented. In addition, the recyclability of the laminate can be maintained.

[0083] The formation of a deposited film on a substrate can be carried out using conventionally known methods, such as physical vapor deposition (PVD) methods including vacuum deposition, sputtering, and ion plating, and chemical vapor deposition (CVD) methods including plasma chemical vapor deposition, thermochemical vapor deposition, and photochemical vapor deposition.

[0084] Furthermore, for example, a composite film consisting of two or more layers of deposited inorganic oxides can be formed and used by combining both physical vapor deposition and chemical vapor deposition methods. The vacuum level of the deposition chamber before oxygen introduction is 10 -2 ~10 -8 A bar of approximately mbar is preferred, and after oxygen introduction, 10 -1 ~10 -6 A pressure of approximately mbar is preferred. The amount of oxygen introduced will vary depending on the size of the deposition machine. Inert gases such as argon, helium, or nitrogen may be used as carrier gases for the oxygen introduced, within reasonable limits. The film transport speed can be approximately 10 to 800 m / min.

[0085] It is preferable that the surface of the deposited film is subjected to the above-mentioned surface treatment. This improves adhesion with adjacent layers.

[0086] (adhesive layer) The adhesive layer may be formed using a conventionally known adhesive. This adhesive may be a one-component curing type, a two-component curing type, or a non-curing type. Furthermore, the adhesive may be either a solvent-free adhesive or a solvent-based adhesive, but from the standpoint of environmental impact, a solvent-free adhesive is preferable. Examples of solvent-free adhesives include polyether-based adhesives, polyester-based adhesives, silicone-based adhesives, epoxy-based adhesives, and urethane-based adhesives. Among these, two-component curing type urethane-based adhesives are preferably used. Examples of solvent-based adhesives include rubber-based adhesives, vinyl-based adhesives, silicone-based adhesives, epoxy-based adhesives, phenol-based adhesives, and olefin-based adhesives.

[0087] Furthermore, if the laminate of the present invention includes an aluminum vapor-deposited film, it is preferable that the adhesive layer provided adjacent to the aluminum vapor-deposited film is made of a cured product of a resin composition containing a polyester polyol, an isocyanate compound, and a phosphate-modified compound. When forming a laminate with a vapor-deposited film into a packaging bag, bending loads are applied to the laminate by the molding machine, which may cause cracks in the aluminum vapor-deposited film. By using the above-described configuration for the adhesive layer, it is possible to prevent the occurrence of cracks in the aluminum vapor-deposited film, and even if cracks do occur, the reduction in oxygen barrier properties and water vapor barrier properties can be suppressed (bending load resistance).

[0088] Polyester polyols have two or more hydroxyl groups as functional groups in one molecule. Isocyanate compounds, on the other hand, have two or more isocyanate groups as functional groups in one molecule. Polyester polyols have, for example, a polyester structure or a polyester polyurethane structure as their main backbone.

[0089] A specific example of a resin composition (adhesive) containing polyester polyol, isocyanate compound, and phosphate-modified compound is the PASLIM series sold by DIC Corporation.

[0090] The resin composition may further contain plate-like inorganic compounds, coupling agents, cyclodextrins and / or their derivatives.

[0091] Examples of polyester polyols having two or more hydroxyl groups in one molecule as functional groups include the following [Example 1] to [Example 3]. [Example 1] Polyester polyol obtained by polycondensation of an ortho-oriented polycarboxylic acid or its anhydride with a polyhydric alcohol [Example 2] Polyester polyol having a glycerol skeleton [Example 3] Polyester polyol having an isocyanuric ring The following describes each type of polyester polyol.

[0092] The polyester polyol of the first example is a polycondensate obtained by polycondensing a polycarboxylic acid component containing at least one orthophthalic acid and its anhydride with 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, polyester polyols in which orthophthalic acid and its anhydride are present in a proportion of 70 to 100% by mass relative to the total polycarboxylic acid components are preferred.

[0093] The polyester polyol according to the first example requires orthophthalic acid and its anhydride as polycarboxylic acid components, but other polycarboxylic acid components may be copolymerized to the extent that the effects of this embodiment are not impaired. Specifically, examples include 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; 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; and polybasic acids such as p-hydroxybenzoic acid, p-(2-hydroxyethoxy)benzoic acid, and ester-forming derivatives of these dihydroxycarboxylic acids. Among these, succinic acid, 1,3-cyclopentanedicarboxylic acid, and isophthalic acid are preferred. Furthermore, two or more of the above-mentioned polycarboxylic acids may be used.

[0094] As an example of a polyester polyol related to the second example, a polyester polyol having a glycerol skeleton represented by general formula (1) can be mentioned. [ka] In general formula (1), R1, R2, and R3 are each independently either H (hydrogen atom) or a group represented by the following general formula (2). [ka]

[0095] In formula (2), n 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 substituents, 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 general formula (2).

[0096] In general formula (1), at least one of R1, R2, and R3 must be a group represented by general formula (2). In particular, it is preferable that all of R1, R2, and R3 are groups represented by general formula (2).

[0097] Furthermore, the compound may be a mixture of two or more compounds in which one of R1, R2, or R3 is a group represented by general formula (2), two of R1, R2, or R3 are groups represented by general formula (2), or all of R1, R2, and R3 are groups represented by general formula (2).

[0098] 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 substituents. If X is substituted by a substituent, it may be substituted by one or more substituents, the substituents being bonded to any carbon atom on X that is different from the free radical. Examples of substituents include chloro, bromo, methyl, ethyl, i-propyl, hydroxyl, methoxy, ethoxy, phenoxy, methylthio, phenylthio, cyano, nitro, amino, phthalimide, carboxyl, carbamoyl, N-ethylcarbamoyl, phenyl, and naphthyl groups.

[0099] In general formula (2), Y represents an alkylene group having 2 to 6 carbon atoms, such as an ethylene group, propylene group, butylene group, neopentylene group, 1,5-pentylene group, 3-methyl-1,5-pentylene group, 1,6-hexylene group, methylpentylene group, and dimethylbutylene group. Among these, propylene and ethylene groups are preferred, with ethylene being the most preferred.

[0100] Polyester resin compounds having a glycerol skeleton represented by general formula (1) can be synthesized by reacting glycerol with an aromatic polycarboxylic acid or its anhydride in which the carboxylic acid is substituted in the ortho position, and a polyhydric alcohol component as essential components.

[0101] Examples of aromatic polycarboxylic acids or their anhydrides in which the carboxylic acid is substituted at the ortho position include orthophthalic 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-anthracenecarboxylic acid or its anhydride. These compounds may have substituents on any carbon atom of the aromatic ring. Examples of substituents include chloro, bromo, methyl, ethyl, i-propyl, hydroxyl, methoxy, ethoxy, phenoxy, methylthio, phenylthio, cyano, nitro, amino, phthalimide, carboxyl, carbamoyl, N-ethylcarbamoyl, phenyl, and naphthyl groups.

[0102] Furthermore, examples of polyhydric alcohol components include alkylenediols having 2 to 6 carbon atoms. Examples of diols include ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, methylpentanediol, and dimethylbutanediol.

[0103] The polyester polyol in the third example is a polyester polyol having an isocyanuric ring represented by the following general formula (3). [ka] In general formula (3), R1, R2, and R3 each independently represent either "-(CH2)n1-OH (where n1 is an integer from 2 to 4)" or the structure of general formula (4). [ka]

[0104] In 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 1,2-phenylene, 1,2-naphthylene, 2,3-naphthylene, 2,3-anthraquinonediyl, and 2,3-anthracenediyl groups, which may have substituents, 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 general formula (4).

[0105] In general formula (3), the alkylene group represented by -(CH2)n1- may be linear or branched. n1 is preferably 2 or 3, with 2 being the most preferred.

[0106] In general formula (4), n² represents an integer between 2 and 4, and n³ represents an integer between 1 and 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 substituents.

[0107] If X is substituted by a substituent, it may be substituted by one or more substituents, the substituents being bonded to any carbon atom on X that is different from the free radical. Examples of substituents include chloro, bromo, methyl, ethyl, i-propyl, hydroxyl, methoxy, ethoxy, phenoxy, methylthio, phenylthio, cyano, nitro, amino, phthalimide, carboxyl, carbamoyl, N-ethylcarbamoyl, phenyl, and naphthyl groups. The substituents of X are preferably hydroxyl, cyano, nitro, amino, phthalimide, carbamoyl, N-ethylcarbamoyl, and phenyl groups, with hydroxyl, phenoxy, cyano, nitro, phthalimide, and phenyl groups being the most preferred.

[0108] In general formula (4), Y represents an alkylene group having 2 to 6 carbon atoms, such as an ethylene group, propylene group, butylene group, neopentylene group, 1,5-pentylene group, 3-methyl-1,5-pentylene group, 1,6-hexylene group, methylpentylene group, and dimethylbutylene group. Among these, propylene and ethylene groups are preferred, with ethylene being the most preferred.

[0109] In general formula (3), at least one of R1, R2, and R3 is a group represented by general formula (4). In particular, it is preferable that all of R1, R2, and R3 are groups represented by general formula (4).

[0110] Furthermore, the compound may be a mixture of two or more compounds in which one of R1, R2, or R3 is a group represented by general formula (4), two of R1, R2, or R3 are groups represented by general formula (4), or all of R1, R2, and R3 are groups represented by general formula (4).

[0111] Polyester polyols having an isocyanuric ring, represented by general formula (3), can be synthesized by reacting a triol having an isocyanuric ring with an aromatic polycarboxylic acid or its anhydride in which the carboxylic acid is substituted in the ortho position, and a polyhydric alcohol component as essential components.

[0112] Examples of triols having an isocyanuric ring include alkylene oxide adducts of isocyanuric acids such as 1,3,5-tris(2-hydroxyethyl)isocyanuric acid and 1,3,5-tris(2-hydroxypropyl)isocyanuric acid.

[0113] Furthermore, examples of aromatic polycarboxylic acids or their anhydrides in which the carboxylic acid is substituted at the ortho position include orthophthalic 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-anthracenecarboxylic acid or its anhydride. These compounds may have substituents on any carbon atom of the aromatic ring.

[0114] Examples of substituents include chloro group, bromo group, methyl group, ethyl group, i-propyl group, hydroxyl group, methoxy group, ethoxy group, phenoxy group, methylthio group, phenylthio group, cyano group, nitro group, amino group, phthalimide group, carboxyl group, carbamoyl group, N-ethylcarbamoyl group, phenyl group, and naphthyl group.

[0115] Furthermore, examples of polyhydric alcohol components include alkylenediols having 2 to 6 carbon atoms. Examples include ethylene glycol, propylene glycol, butylene glycol, neopentyl glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, methylpentanediol, and dimethylbutanediol. In particular, polyester polyol compounds having an isocyanuric ring are preferred when 1,3,5-tris(2-hydroxyethyl)isocyanuric acid or 1,3,5-tris(2-hydroxypropyl)isocyanuric acid is used as the triol compound having an isocyanuric ring, an aromatic polycarboxylic acid in which the carboxylic acid is substituted at the ortho position or orthophthalic anhydride is used as the anhydride, and ethylene glycol is used as the polyhydric alcohol, as these compounds exhibit particularly excellent oxygen barrier properties and adhesion.

[0116] The isocyanuric ring is highly polar and trifunctional, which can increase the overall polarity of the system and increase the crosslinking density. From this viewpoint, it is preferable to contain 5% by mass or more of the isocyanuric ring relative to the total solid content of the adhesive resin.

[0117] Isocyanate compounds have two or more isocyanate groups in their molecule. Furthermore, the isocyanate compound may be aromatic or aliphatic, and may be 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 conventional method. In particular, polyisocyanate compounds having three or more isocyanate groups are preferred from the viewpoint of adhesion and retort resistance, and aromatic compounds are preferred from the viewpoint of oxygen barrier properties and water vapor barrier properties.

[0118] Specific examples of isocyanate compounds 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 low molecular weight active hydrogen compounds or their alkylene oxide adducts, or high molecular weight active hydrogen compounds. Examples of low molecular weight active hydrogen compounds include ethylene glycol, propylene glycol, metaxylylene alcohol, 1,3-bishydroxyethylbenzene, 1,4-bishydroxyethylbenzene, trimethylolpropane, glycerol, pentaerythritol, erythritol, sorbitol, ethylenediamine, monoethanolamine, diethanolamine, triethanolamine, and metaxylylenediamine. Examples of molecular weight active hydrogen compounds include high molecular weight active hydrogen compounds of various polyester resins, polyether polyols, and polyamides.

[0119] Phosphate-modified compounds are, for example, compounds represented by the following general formulas (5) or (6). [ka] 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, an optionally substituted phenyl group, and an alkyl group having 1 to 4 carbon atoms, but at least one of them is a hydrogen atom, and n represents an integer from 1 to 4. [ka] 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, an optionally substituted phenyl group, and an alkyl group having 1 to 4 carbon atoms with a (meth)acryloyloxy group, where n is an integer from 1 to 4, x is an integer from 0 to 30, and y is an integer from 0 to 30, except when both x and y are 0.

[0120] More specifically, examples include phosphoric acid, pyrophosphate, triphosphate, 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, and one or more of these can be used.

[0121] The content of the phosphate-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 phosphate-modified compound to 0.005% by mass or more, the oxygen barrier and water vapor barrier properties of the laminate of the present invention can be improved. Furthermore, by setting the content of the phosphate-modified compound to 10% by mass or less, the adhesion of the adhesive layer can be improved.

[0122] The resin composition containing polyester polyol, isocyanate compound, and phosphate-modified compound may also contain plate-like inorganic compound, which can improve the adhesion of the adhesive layer. Furthermore, it can improve the bending load resistance of the laminate of the present invention. Examples of plate-like inorganic compounds include kaolinite-serpentine clay minerals (haloysite, kaolinite, endelite, dickite, nacrite, antigorite, chrysotile, etc.) and pyrophyllite-talc group minerals (pyrophyllite, talc, kerolite, etc.).

[0123] Examples of coupling agents include silane-based coupling agents, titanium-based coupling agents, and aluminum-based coupling agents represented by the general formula (7) below. These coupling agents may be used individually or in combination of two or more types. [ka]

[0124] 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( Examples include 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-isocyanatetopropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, and 3-triethoxysilyl-N-(1,3-dimethylbutylidene).

[0125] Examples of titanium-based coupling agents include isopropyl triisostearoyl titanate, isopropyl tri(N-aminoethyl-aminoethyl) titanate, isopropyl tridodecylbenzenesulfonyl titanate, isopropyl tris(dioctyl pyrophosphate) titanate, tetraoctyl bis(didodecyl phosphite) titanate, tetraoctyl bis(ditridecyl phosphite) titanate, bis(dioctyl pyrophosphate) oxyacetate titanate, bis(dioctyl pyrophosphate) ethylene titanate, isopropyl trioctainol titanate, isopropyl dimethacrylate isostearoyl titanate, isopropyl isostearoyl diacrylic titanate, diisostearoylethylene titanate, isopropyl tri(dioctyl phosphate) titanate, isopropyl tricumylphenyl titanate, and dicumylphenyl oxyacetate titanate.

[0126] Specific examples of aluminum-based coupling agents include, for example, acetalkoxyaluminum diisopropylate, diisopropoxyaluminum ethyl acetacetate, diisopropoxyaluminum monomethacrylate, isopropoxyaluminum alkyl acetacetate mono(dioctyl phosphate), aluminum-2-ethylhexanoate oxide trimer, aluminum stearate oxide trimer, and alkyl acetacetate aluminum oxide trimer.

[0127] The resin composition may contain cyclodextrin and / or its derivatives, thereby improving the adhesion of the adhesive layer. Furthermore, the bending load resistance of the laminate of the present invention can be further improved. Specifically, for example, cyclodextrins such as alkylated cyclodextrins, acetylated cyclodextrins, and hydroxyalkylated cyclodextrins, in which the hydrogen atom of the hydroxyl group of the glucose unit of a cyclodextrin is substituted with another functional group, can be used. Branched cyclic dextrins can also be used. Furthermore, the cyclodextrin skeleton in cyclodextrins and cyclodextrin derivatives may be any of the following: α-cyclodextrin consisting of 6 glucose units, β-cyclodextrin consisting of 7 glucose units, or γ-cyclodextrin consisting of 8 glucose units. These compounds may be used individually or in combination of two or more. Furthermore, these cyclodextrins and / or their derivatives may collectively be referred to as dextrin compounds from now on.

[0128] From the viewpoint of compatibility and dispersibility with resin compositions, it is preferable to use cyclodextrin derivatives as the cyclodextrin compound.

[0129] Examples of alkylated cyclodextrins include methyl-α-cyclodextrin, methyl-β-cyclodextrin, and methyl-γ-cyclodextrin. These compounds may be used individually or in combination of two or more.

[0130] Examples of acetylated cyclodextrins include monoacetyl-α-cyclodextrin, monoacetyl-β-cyclodextrin, and monoacetyl-γ-cyclodextrin. These compounds may be used individually or in combination of two or more.

[0131] Examples of hydroxyalkylated cyclodextrins include hydroxypropyl-α-cyclodextrin, hydroxypropyl-β-cyclodextrin, and hydroxypropyl-γ-cyclodextrin. These compounds may be used individually or in combination of two or more.

[0132] Within the limits that do not impair the properties of the present invention, the adhesive layer may contain additives such as pigments such as titanium dioxide, zinc oxide, and carbon black, dyes such as disperse dyes, acid dyes, and cationic dyes, antioxidants, lubricants, colorants, stabilizers, wetting agents, thickeners, coagulants, gelling agents, anti-settling agents, softeners, curing agents, plasticizers, leveling agents, ultraviolet absorbers, and flame retardants.

[0133] The thickness of the adhesive layer is not particularly limited and can be, for example, 1 μm or more and 10 μm or less.

[0134] (Middle class) In one embodiment, the laminate of the present invention comprises a polyethylene layer or a polypropylene layer as an intermediate layer.

[0135] The polyethylene or polypropylene layer may be composed of a stretched film, which may be either a uniaxially oriented or biaxially oriented film, and the preferred stretching ratio is as described above. Furthermore, the polyethylene layer or polypropylene layer may be an extruded resin layer formed by melt-extruding polyethylene or polypropylene.

[0136] The thickness of the polyethylene or polypropylene layer is preferably 10 μm or more and 70 μm or less, and more preferably 15 μm or more and 50 μm or less.

[0137] In one embodiment, the laminate of the present invention comprises a gas barrier layer made of a gas barrier resin as an intermediate layer. The laminate of the present invention, by having such an intermediate layer, can improve oxygen barrier properties and water vapor barrier properties. Examples of gas barrier resins include ethylene-vinyl alcohol copolymer (EVOH), polyvinyl alcohol, polyacrylonitrile, polyamides such as nylon 6, nylon 6,6 and polymethaxylylene adipamide (MXD6), polyesters, polyurethanes, and (meth)acrylic resins.

[0138] The thickness of the gas barrier layer is preferably 0.01 μm or more and 10 μm or less, and more preferably 0.1 μm or more and 5 μm or less. By setting the thickness of the gas barrier layer to 0.01 μm or more, the oxygen barrier and water vapor barrier properties of the laminate of the present invention can be further improved. By setting the thickness of the gas barrier layer to 10 μm or less, the recyclability of the laminate of the present invention can be maintained.

[0139] In one embodiment, the intermediate layer comprises a vapor-deposited film. The types of vapor-deposited films that can be used, preferred thickness, and formation method are as described above.

[0140] In one embodiment, the intermediate layer comprises a barrier coat layer. The configuration, preferred thickness, and formation method of the barrier coat layer are as described above.

[0141] (packaging bag) The packaging bag 20 of the present invention includes a spout 21, as shown in Figure 7. A cap 22 can be screwed onto the upper end of the spout 21. The material of the spout is not particularly limited, but it is preferable to use polyethylene when the base material and sealant layer are made of polyethylene, and to use polypropylene when the base material and sealant layer are made of polypropylene. Furthermore, the spout 21 is equipped with a flange portion 23, as shown in Figure 7.

[0142] Furthermore, as shown in Figure 7, the packaging bag 20 includes a storage section 24 for containing contents, which is made up of the laminated material described above. The contents to be stored are not particularly limited, and can be appropriately selected and stored, for example, juices, fruit juices, jelly-like beverages, nutritional drinks, liquid or powdered seasonings or detergents, etc.

[0143] In one embodiment, as shown in Figure 7, the packaging bag 20 can be manufactured by overlapping two of the laminates 25 and 26 so that the sealant layers face each other, heat-sealing three sides to create a storage section 24, then sandwiching the spout 21 with the remaining side, heat-sealing it, and welding it together.

[0144] In one embodiment, as shown in Figure 8, the packaging bag 30 can be manufactured by overlapping two of the laminates 31 and 32 so that the sealant layers face each other, and heat-sealing one side to form the bottom 33; then folding two more laminates 34 and 35 in a V-shape so that the sealant layers face outwards, sandwiching them from both ends of the opposing laminates, and heat-sealing to form a gusset portion and create a storage portion 36; and finally sandwiching the spout 37 with the remaining side, heat-sealing, and welding it together. Here, we have described side-gusset packaging bags, but the gusset may be provided only at the bottom, or it may be provided on both the sides and the bottom.

[0145] The following describes the structure of one embodiment of the spout provided in the packaging bag of the present invention. As shown in Figures 9 and 10, the spout 40 comprises a hollow cylindrical portion 41, a flange portion 42 provided on the outer circumferential surface of the cylindrical portion 41, and a welded portion 43 that is welded to the laminate. The welded portion 43 may be provided with ribs 44 to improve adhesion to the laminate. Furthermore, it is preferable that the welded portion 43 has a flat surface, as shown in Figure 9. This further improves adhesion to the laminate. In the packaging bag, this flat surface extends in a direction parallel to the laminate to which it is welded. As shown in Figure 9, a through-hole is formed in the cylindrical portion 41, through which the contents contained in the packaging bag are poured out. The spout 40 may also be equipped with a threaded portion 46 for screwing on a cap. The spout 40 may also be equipped with an opening 45. While the spout shape is given as an example, it is not limited to this.

[0146] In Figures 7 and 8, the shaded areas represent the heat-sealed portions. The heat-sealing method is not particularly limited and can be carried out using known methods such as bar seals, rotary roll seals, belt seals, impulse seals, high-frequency seals, and ultrasonic seals. [Examples]

[0147] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0148] Example 1 A 25 μm thick, longitudinally uniaxially oriented polyethylene film (stretching ratio: approximately 5 times) was prepared as the base film.

[0149] A silica vapor-deposited film with a thickness of 0.03 μm was formed on one side of the substrate film by CVD.

[0150] Mix 385g of water, 67g of isopropyl alcohol, and 9.1g of 0.5N hydrochloric acid. Solution A was prepared by mixing 175 g of tetraethoxysilane as a metal alkoxide and 9.2 g of glycidoxypropyltrimethoxysilane as a silane coupling agent in a solution adjusted to pH 2.2 while cooling to 10°C. Furthermore, as a water-soluble polymer, solution B was prepared by mixing 14.7 g of polyvinyl alcohol with a saponification value of 99% or higher and a degree of polymerization of 2400, 324 g of water, and 17 g of isopropyl alcohol. Next, solution A and solution B were mixed in a weight ratio of 6.5:3.5 to prepare a barrier coating agent. This agent was then applied to the vapor-deposited film by spin coating and heat-treated to form a barrier coating layer. An image was formed on this barrier coat layer using a gravure printing press.

[0151] On the image-formed barrier coat layer, a 2 μm thick light-shielding printed layer was formed using a gravure printing method, comprising a white ink layer (Finato R794 White, manufactured by DIC Graphics Co., Ltd.), a yellow ink layer (Finato F407B Medium Yellow, manufactured by DIC Graphics Co., Ltd.), and a red ink layer (Finato F114 Red, manufactured by DIC Graphics Co., Ltd.). When the light transmittance of this light-shielding printed layer for ultraviolet light below 570 nm, visible light, and near-infrared light was measured, it was found to be 0.02% or less.

[0152] On the light-shielding printed layer formed as described above, apply a two-component curing polyester adhesive at a rate of 3.5 g / m². 2 The laminate of the present invention was obtained by applying the material and then dry laminating it with an 80 μm thick unstretched polyethylene film.

[0153] The laminated material was cut to a size of 100mm wide x 150mm long. The two laminated pieces cut as described above were placed on top of each other so that the two sealant layers faced each other. At both ends, a laminated piece cut to a size of 100mm wide x 50mm high and folded into a V-shape with the sealant on the outside was sandwiched in between. Next, one vertical side and the side enclosing the V-shaped laminate were heat-sealed to form a gusset and a storage compartment.

[0154] From the remaining side, a polyethylene spout, which contains a jelly drink and has the shape shown in Figure 9, is manufactured by injection molding and welded to the laminate by heat sealing the remaining side. At the same time, a cap made by injection molding is screwed onto the spout to obtain the spout packaging bag of the present invention. No leaks, tipping, or buckling were observed in the packaging bags. Furthermore, five drop tests from 1.2m showed no rupture or leakage. In addition, outdoor sunlight exposure tests under the following conditions showed no discoloration or fading of the contents due to light. <Outdoor sunlight exposure test> Average temperature: 14℃ Average humidity: 72% Test period: 30 days (sunlight hours: 151 hours) Evaluation method: Visually check the color of the contents before and after the test to confirm that there is no discoloration or fading.

[0155] The oxygen permeability of this laminate was measured in accordance with JIS K 7126 (isobaric method) using an OXTRAN2 / 20 manufactured by MOCON, Inc., USA, under conditions of 23°C and 50% relative humidity, and was found to be 1.42 cc / m2·d·atm. Furthermore, the water vapor transmission rate of the laminate was measured in accordance with JIS K 7129 B method using PERMATRAN3 / 31 manufactured by MOCON, Inc., USA, under conditions of 40°C and 90% relative humidity, and was found to be 1.55 g / m2·d.

[0156] Example 2 A 25 μm thick, longitudinally uniaxially oriented polyethylene film (stretching ratio: approximately 5 times) was prepared as the base film.

[0157] A silica vapor-deposited film with a thickness of 0.03 μm was formed on one side of the substrate film by CVD.

[0158] The above barrier coating agent was applied to a vapor-deposited film by spin coating and then heat-treated to form a barrier coating layer. An image was then formed on this barrier coating layer using a gravure printing machine.

[0159] Next, a sealant layer was prepared as described below. First, resin compositions A to D were prepared as follows. Ethylene-α-olefin copolymer polymerized using a single-site catalyst (metallocene catalyst) [manufactured by Sumitomo Mitsui Chemicals, Ltd., product name: Evolu-SP2020, density: 0.916 g / m³] 3 Resin composition A was prepared by thoroughly kneading 100.0 parts by mass of melt flowrate (MFR, 1.5 g / 10 min), 0.1 parts by mass of erucic acid amide, and 0.2 parts by mass of synthetic silica.

[0160] Ethylene-α-olefin copolymer [Manufactured by Asahi Kasei Corporation, trade name MA2010, density 0.921 g / m³] 3 Resin composition B was prepared by thoroughly kneading 80.0 parts by mass of melt flowrate (MFR, 1.0 g / 10 min) with 20.0 parts by mass of titanium dioxide and 1.2 parts by mass of carbon black as light-shielding pigments.

[0161] Ethylene-α-olefin copolymer [Manufactured by Asahi Kasei Corporation, trade name MA2010, density 0.921 g / m³] 3 Resin composition C was prepared by thoroughly kneading 80.0 parts by mass of melt flowrate (MFR, 1.0 g / 10 min) and 20.0 parts by mass of titanium dioxide as a light-shielding pigment.

[0162] Ethylene-α-olefin copolymer [Manufactured by Asahi Kasei Corporation, trade name MA2010, density 0.921 g / m³] 3 Resin composition D was prepared by thoroughly kneading 100.0 parts by mass of melt flowrate (MFR, 1.0 g / 10 min) and 0.1 parts by mass of erucic acid amide.

[0163] The resin compositions A to D prepared above were co-extruded using an air-cooled, top-blown inflation co-extrusion film press to produce a sealant layer consisting of four layers with a total thickness of 130 μm. The layers were made of resin composition A (60 μm), resin composition B (20 μm), resin composition C (20 μm), and resin composition D (30 μm). The sealant layer produced as described above was milky white, aesthetically pleasing, and had sufficient light-shielding or light-blocking properties, with almost no light transmission throughout the entire area, which was extremely good. When the light transmittance of this sealant layer for ultraviolet light below 570 nm, visible light, and near-infrared light was measured, it was found to be 0.3% or less.

[0164] Next, the surface of the layer made of resin composition D in the sealant layer prepared as described above is corona treated, and a two-component curing urethane adhesive (4.0 g / m²) is applied to this surface. 2The laminate of the present invention was obtained by applying the material and then dry laminating it with a barrier coat layer. Similar to Example 1, the oxygen permeability and water vapor permeability of the laminate were measured, and the results were 1.53 cc / m², respectively. 2 ·d·atm, 1.66g / m³ 2 It was d.

[0165] Furthermore, a packaging bag was prepared in the same manner as in Example 1. No leakage, tipping, or buckling was observed in the packaging bag. In addition, when a drop test was performed from 1.2m five times, no rupture or leakage was observed at all. Moreover, no discoloration or fading of the contents due to light was observed.

[0166] Example 3 The laminate of the present invention was prepared in the same manner as in Example 1, except that the base film was changed to a biaxially oriented polypropylene film with a thickness of 25 μm (stretching ratio: 3 to 6 times), and the sealant layer was changed to an unstretched polypropylene film with a thickness of 60 μm. Similar to Example 1, the oxygen permeability and water vapor permeability of the laminate were measured, and the results were 1.27 cc / m², respectively. 2 ·d·atm, 0.75g / m 2 It was d. Furthermore, a packaging bag was prepared in the same manner as in Example 1. No leakage, tipping, or buckling was observed in the packaging bag. In addition, when a drop test was performed from 1.2m five times, no rupture or leakage was observed at all. Moreover, no discoloration or fading of the contents due to light was observed. The spout was made of polypropylene.

[0167] Example 4 The sealant layer was prepared as follows. First, resin compositions A' to C' were prepared as follows. Polypropylene-ethylene block copolymer (density = 0.9 g / cm³) 3Resin composition A' was prepared by thoroughly kneading 100 parts by mass (MFR = 0.5 g / 10 min), 0.5 parts by mass of synthetic silica, 0.05 parts by mass of erucic acid amide, and 0.05 parts by mass of ethylenebisoleic acid amide.

[0168] Functional polypropylene-ethylene block copolymer (density = 0.9 g / cm³) 3 Resin composition B' was prepared by thoroughly kneading 80.0 parts by mass of melt flowrate (MFR = 0.5 g / 10 min) and 20.0 parts by mass of titanium dioxide as a light-shielding pigment.

[0169] Functional polypropylene-ethylene block copolymer (density = 0.9 g / cm³) 3 Resin composition C' was prepared by thoroughly kneading 73.5 parts by mass of (MFR=0.5g / 10min), 1.5 parts by mass of benzopyrene-free carbon black as a light-shielding pigment, and 25.0 parts by mass of titanium dioxide.

[0170] Using an over-blowing air-cooled inflation co-extrusion film manufacturing machine, the resin compositions A' to C' prepared above were used to produce a sealant layer with a total thickness of 70 μm, consisting of three types of five layers: a 10 μm layer of resin composition A', a 20 μm layer of resin composition B', a 10 μm layer of resin composition C', a 10 μm layer of resin composition A', and a 20 μm layer of resin composition A'. Upon visual inspection of the sealant layer, it was found to be milky white and aesthetically pleasing. The laminate was fabricated in the same manner as in Example 3, except that the sealant layer was made using the method described above. Similar to Example 1, the oxygen permeability and water vapor permeability of the laminate were measured, and the results were 1.34 cc / m², respectively. 2 ·d·atm, 0.84g / m³ 2 It was d. Furthermore, a packaging bag was prepared in the same manner as in Example 1. No leakage, tipping, or buckling was observed in the packaging bag. In addition, when a drop test was performed from 1.2m five times, no rupture or leakage was observed at all. Moreover, no discoloration or fading of the contents due to light was observed. The spout was made of polypropylene.

[0171] Comparative Example 1 A laminate was prepared in the same manner as in Example 1, except that the base film was changed to an unstretched polyethylene film with a thickness of 25 μm. Next, an attempt was made to prepare a packaging bag in the same manner as in Example 1, but the heat resistance of the base film was insufficient, and heat sealing was not possible. [Explanation of symbols]

[0172] 10: Laminate, 11: Base material, 12: Sealant layer, 13: Light-shielding printing layer, 14: Light-shielding layer, 15: Laminate layer, 16: Heat seal layer, 17: Barrier coat layer, 20: Packaging bag, 21: Spout, 22: Lid stopper, 23: Flange section, 24: Storage section, 25, 26: Laminate, 30: Packaging bag, 31, 32: Laminate, 33: Bottom section, 34, 35: Laminate, 40: Spout, 41: Cylinder section, 42: Flange section, 43: Welded section, 44: Rib, 45: Opening, 46: Screw section

Claims

1. A laminate comprising a substrate and a sealant layer, The substrate and the sealant layer are made of the same material. The substrate is subjected to at least one of stretching and electron beam irradiation. A laminate for a spouted packaging bag, characterized in that the aforementioned same material is polyethylene or polypropylene.

2. A packaging bag having a storage compartment and a spout, The storage section is made of the laminate described in claim 1, A packaging bag with a spout, characterized in that the spout is made of the material constituting the sealant layer of the laminate.

3. A spouted packaging bag according to claim 2, further comprising gussets on both sides.

4. The spout packaging bag according to claim 2 or 3, wherein the spout comprises a cylindrical portion, a flange portion, and a welded portion.

5. The spouted packaging bag according to claim 4, wherein the welded portion has a flat surface.

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