Laminates for packaging materials and packaging materials

Abstract

To provide a laminate for a packaging material which is excellent in recyclability while having high strength and heat resistance.SOLUTION: A laminate for a packaging material has a base material, a first adhesive layer, an intermediate layer, a second adhesive layer, and a heat seal layer in this order, wherein the base material is a biaxially stretched polypropylene film, the intermediate layer includes a biaxially stretched polypropylene film, a vapor-deposited film, and a gas barrier coating film adjacent to the vapor-deposited film. The gas barrier coating film is a coating film containing at least one resin composition of a hydrolysate of a metal alkoxide obtained by polycondensation of a mixture of a metal alkoxide and a water-soluble polymer, or a resin composition of a hydrolysis condensate of the metal alkoxide. The heat seal layer is an unstretched polypropylene film, the adhesive is a urethane-based adhesive, the biaxially stretched polypropylene films of the base material and the intermediate layer are separately molded, and the content of polypropylene in the whole laminate for packaging material is 80 mass% or more.SELECTED DRAWING: Figure 1

Description

[Technical Field] 【0001】 The present invention relates to a laminate for packaging materials and a packaging material composed of the laminate. [Background technology] 【0002】 Traditionally, resin films made from resin materials have been used as constituent materials for packaging. For example, resin films made from polyolefins are widely used in packaging materials 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 packaging materials. Instead, they are used in combination with resin films made from polyester, polyamide, etc. Therefore, typical packaging materials consist of laminated films in which the base material and the heat-seal layer are made of different materials (for example, Patent Document 1). 【0004】 In recent years, with the growing demand for a circular economy, there has been a need for packaging materials with high recyclability. However, conventional packaging materials are composed of different types of resin materials, as mentioned above, and it is difficult to separate them, so they are not currently recycled. [Prior art documents] [Patent Documents] 【0005】 [Patent Document 1] Japanese Patent Publication No. 2009-202519 [Overview of the project] [Problems that the invention aims to solve] 【0006】 The inventors have found that by using polyolefin resin, which was conventionally used as a heat-seal layer, as a base material by making it into a stretched resin film, and then laminating this base material with a heat-seal layer made of polyolefin, it is possible to create a recyclable packaging material while maintaining the strength and heat resistance required for packaging. Furthermore, we found that the strength can be improved by providing an intermediate layer, which is a stretched resin film, between the base material and the heat-seal layer. 【0007】 This invention has been made in view of the above findings, and the problem it aims to solve is to provide a laminate for packaging materials that can realize a packaging material that has high strength and heat resistance while also being highly recyclable. Furthermore, the problem that the present invention aims to solve is to provide a packaging material composed of a laminate for packaging materials. [Means for solving the problem] 【0008】 The present invention provides a laminate for packaging materials comprising, in this order, a base material, a first adhesive layer containing an adhesive, an intermediate layer, a second adhesive layer containing an adhesive, and a heat seal layer, wherein the base material is a biaxially oriented polypropylene film, the intermediate layer comprises a biaxially oriented polypropylene film and a vapor-deposited film, and a gas barrier coating film is provided adjacent to the vapor-deposited film, the gas barrier coating film is a coating film containing at least one resin composition of a hydrolyzed metal alkoxide or a hydrolyzed condensate of a metal alkoxide obtained by polycondensation of a mixture of a metal alkoxide and a water-soluble polymer (except for the gas barrier coating film further containing an inorganic layered compound), the heat seal layer is an unstretched polypropylene film, the adhesive is a urethane-based adhesive, the biaxially oriented polypropylene film of the base material and the biaxially oriented polypropylene film of the intermediate layer are molded separately, and the polypropylene content in the entire laminate for packaging materials is 80% by mass or more. 【0009】 In one embodiment, an image is formed on the surface of the substrate on the side of the first adhesive layer. 【0010】 The packaging material of the present invention is characterized by being composed of the above-mentioned laminate for packaging materials. 【0011】 The packaging bag of the present invention is characterized by comprising the above-mentioned packaging material. 【0012】 The present invention relates to a method for manufacturing a laminate for packaging materials, wherein the laminate for packaging materials comprises, in this order, at least a base material, a first adhesive layer containing an adhesive, an intermediate layer, a second adhesive layer containing an adhesive, and a heat-seal layer, and the base material is a biaxially oriented polypropylene film. The present invention relates to a laminated film comprising: an intermediate layer comprising a biaxially oriented polypropylene film and a vapor-deposited film, wherein a gas barrier coating film is provided adjacent to the vapor-deposited film, the gas barrier coating film comprising at least one resin composition of a hydrolyzed metal alkoxide or a hydrolyzed condensate of a metal alkoxide obtained by polycondensation of a mixture of a metal alkoxide and a water-soluble polymer (except for the gas barrier coating film further comprising an inorganic layered compound), a heat seal layer comprising an unstretched polypropylene film, an adhesive comprising a urethane-based adhesive, and a polypropylene content of 80% by mass or more in the entire laminate for packaging materials, and comprising the steps of: forming a first adhesive layer by bonding the substrate and the intermediate layer with an adhesive to obtain a laminated film, and forming a second adhesive layer by bonding the intermediate layer side of the laminated film to the heat seal layer with an adhesive to obtain a laminate for packaging materials. 【0013】 In one embodiment, the step of obtaining a laminate for packaging material is to form a second adhesive layer by bonding a biaxially oriented polypropylene film intermediate layer and a heat-seal layer with an adhesive. 【0014】 In one embodiment, the method further includes the step of forming an image on the surface of the substrate on the side of the first adhesive layer. 【0015】 In one embodiment, the adhesives contained in the first adhesive layer and the second adhesive layer are solvent-free adhesives. [Effect of the Invention] 【0016】 According to the present invention, it is possible to provide a laminate for a packaging material that can realize a packaging material having high strength, heat resistance, and excellent recyclability. 【0017】 Furthermore, according to the present invention, it is possible to provide a packaging material composed of the laminate for a packaging material. [Brief Description of the Drawings] 【0018】 [Figure 1] It is a schematic cross-sectional view showing one embodiment of the laminate for a packaging material of the present invention. [Figure 2] It is a schematic cross-sectional view showing one embodiment of the laminate for a packaging material of the present invention. [Figure 3] It is a perspective view showing one embodiment of a packaging material produced using the laminate for a packaging material of the present invention. [Figure 4] It is a perspective view showing one embodiment of a packaging material produced using the laminate for a packaging material of the present invention. [Modes for Carrying Out the Invention] 【0019】 (Laminate for Packaging Material) As shown in FIG. 1, the laminate 10 for a packaging material of the present invention includes at least a base material 11, an intermediate layer 12, and a heat seal layer 13. In the present invention, the base material, the intermediate layer, and the heat seal layer are made of the same material, that is, polyolefin, whereby the recyclability of the laminate for a packaging material of the present invention can be improved. 【0020】 Also, in one embodiment of the present invention, as shown in FIG. 2, the laminate 10 for a packaging material can further include an adhesive layer 14 between the base material 11 and the intermediate layer 12, and between the intermediate layer 12 and the heat seal layer 13. 【0021】 The content of the same polyolefin in the entire laminate for packaging materials of the present invention is preferably 90% by mass or more. By ensuring that the content of the same polyolefin in the entire laminate for packaging materials of the present invention is 90% by mass or more, the recyclability of the laminate for packaging materials of the present invention can be improved. 【0022】 The following describes each layer that constitutes the laminate for packaging materials of the present invention. 【0023】 (base material) The base material of the laminated packaging material of the present invention is made of polyolefin, and this polyolefin is the same as the polyolefin that constitutes the intermediate layer and heat seal layer described below. By adopting this configuration, the recyclability of the laminated packaging material can be improved. 【0024】 The substrate of the laminate for packaging materials of the present invention is subjected to a stretching treatment. This improves the strength and heat resistance of the substrate. Such a substrate may be a uniaxially oriented resin film or a biaxially oriented resin film. 【0025】 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 laminate for packaging materials of the present invention can be improved. Furthermore, the transparency of the substrate can be improved, thereby improving the visibility of images formed on the adhesive layer side surface of the substrate. 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 stretched film, it is preferable to set it to 10 times or less. 【0026】 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 stretching ratio in the transverse direction (TD) of the substrate to 2 times or more, the strength and heat resistance of the laminate for packaging materials of the present invention can be improved. Furthermore, the transparency of the substrate can be improved, thereby improving the visibility of images formed on the adhesive layer side surface of the substrate. On the other hand, there is no particular upper limit to the stretching ratio in the transverse direction (TD) of the substrate, but from the viewpoint of the breaking limit of the stretched film, it is preferable to set it to 10 times or less. 【0027】 As mentioned above, the polyolefin that can be used as the base material must be the same as the polyolefin that constitutes the intermediate layer and the heat seal layer. Examples of such polyolefins include polyethylene, polypropylene, polymethylpentene, ethylene-propylene copolymer, and propylene-butene copolymer, with polyethylene and polypropylene being preferred among these. 【0028】 As polyethylene, its density is 0.945 g / cm³. 3 Ultra-high density polyethylene (HDPE), density 0.925~0.945 g / cm³ 3 Medium-density polyethylene (MDPE), density 0.925 g / cm³ 3 Examples include low-density polyethylene (LDPE) and linear low-density polyethylene (LLDPE) with a density of less than 1.5 mm. 【0029】 In one embodiment, a substrate can be used that comprises a layer containing high-density polyethylene and a layer containing medium-density polyethylene. By providing a high-density polyethylene layer on the outside of the base material, the strength and heat resistance of the laminate for packaging materials of the present invention can be improved. Furthermore, by providing a medium-density polyethylene layer, the stretchability of the resin film constituting the base material can be improved. 【0030】 For example, it has a structure consisting of a high-density polyethylene layer and a medium-density polyethylene layer from the outside in. This configuration improves the stretchability of the film. Furthermore, it improves the strength and heat resistance of the laminate for packaging materials according to the present invention. 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 laminate for packaging materials of the present invention 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 film can be improved. 【0031】 Furthermore, for example, the structure can consist of a high-density polyethylene layer, a medium-density polyethylene layer, and another high-density polyethylene layer from the outside in. This configuration improves the stretchability of the film. Furthermore, it improves the strength and heat resistance of the laminated packaging material of the present invention. Additionally, it prevents curling in 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 laminate for packaging materials of the present invention 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 film can be improved. 【0032】 Furthermore, for example, the structure can consist of a high-density polyethylene layer, a medium-density polyethylene layer, a low-density polyethylene layer or a linear low-density polyethylene layer, a medium-density polyethylene layer, and a high-density polyethylene layer, from the outside in. This configuration improves the stretchability of the film. Furthermore, it improves the strength and heat resistance of the laminated packaging material of the present invention. It also prevents curling in the substrate. Moreover, it improves the processability of the film. 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 laminate for packaging materials of the present invention 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 film can be improved. Furthermore, it is preferable that the thickness of the high-density polyethylene layer be thinner than the thickness of the low-density polyethylene layer or the linear low-density polyethylene layer. The ratio of the thickness of the high-density polyethylene layer to the thickness of the low-density polyethylene layer or linear low-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 low-density polyethylene layer or linear low-density polyethylene layer to 1 / 10 or more, heat resistance can be improved. Furthermore, by making the ratio of the thickness of the high-density polyethylene layer to the thickness of the low-density polyethylene layer or linear low-density polyethylene layer 1 / 1 or less, the processability for stretching can be improved. 【0033】 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 material are important, homopolymers can be used, and when impact resistance and other properties are important, random copolymers can be used. 【0034】 Furthermore, instead of using olefin monomers obtained from fossil fuels as raw materials to obtain polyolefins, biomass-derived olefin monomers may be used. Since such biomass-derived olefin monomers are carbon-neutral materials, they can be used to create packaging materials with an even lower environmental impact. Such biomass-derived polyolefins, such as polyethylene, can be produced by methods described in Japanese Patent Publication No. 2013-177531. Alternatively, commercially available biomass-derived polyolefins (for example, GreenPE, commercially available from Braschem) may be used. 【0035】 In addition, recycled polyolefins obtained through mechanical recycling can also be used. Mechanical recycling generally involves crushing collected polyolefin films, washing them with alkali to remove dirt and foreign matter from the film surface, and then drying them under high temperature and reduced pressure for a certain period of time to disperse contaminants remaining inside the film, thereby decontaminating the polyolefin film and returning it to its original polyolefin state. 【0036】 The substrate may have an image formed on its surface. The image may be formed on any surface of the substrate, but it is preferable to form the image on the surface facing the adhesive layer, as this prevents contact with the outside air and prevents deterioration over time. Furthermore, the resulting images are not particularly limited and may represent letters, patterns, symbols, or combinations thereof. Image formation can be performed using conventionally known inks, but it is preferable to use biomass-derived inks. This makes it possible to produce packaging materials with a lower environmental impact using the laminate of the present invention. The method of image formation is not particularly limited and can include conventionally known printing methods such as gravure printing, offset printing, and flexographic printing. Among these, flexographic printing is preferred because it can reduce the environmental impact. 【0037】 Furthermore, it is preferable that the substrate is surface-treated. This improves 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. 【0038】 The thickness of the substrate is preferably 5 μm to 300 μm, and more preferably 7 μm to 100 μm. By making the substrate thickness 5 μm or more, the strength of the laminate for packaging materials of the present invention can be improved. Furthermore, by making the substrate thickness 300 μm or less, the processability of the laminate for packaging materials of the present invention can be improved. 【0039】 The substrate can be produced by forming a film from polyolefin using a T-die method or inflation method, and then stretching the film. The inflation method allows for simultaneous film formation and stretching. 【0040】 When preparing a substrate using the T-die method, the polyolefin MFR is preferably 5 g / 10 min or more and 20 g / 10 min or less. By setting the polyolefin MFR to 5g / 10min or more, the processability of the laminate for packaging materials of the present invention can be improved. Furthermore, by setting the polyolefin MFR to 20g / 10min or less, it is possible to prevent the resin film from rupturing. 【0041】 When preparing a substrate by the inflation method, the MFR of the polyolefin is preferably 0.5 g / 10 min or more and 5 g / 10 min or less. By setting the polyolefin MFR to 0.5 g / 10 min or more, the processability of the laminate for packaging materials of the present invention can be improved. Furthermore, by setting the polyolefin MFR to 5 g / 10 min or less, the film-forming properties can be improved. 【0042】 Furthermore, the base material is not limited to that prepared by the above method; commercially available materials may also be used. 【0043】 (Middle class) The laminate for packaging materials of the present invention includes an intermediate layer between the base material and the heat-seal layer. This improves the strength of the laminate for packaging materials of the present invention. The intermediate layer contains the same polyolefin as the polyolefin contained in the base material and the heat seal layer. Furthermore, the intermediate layer, like the base material, has undergone a stretching treatment. The stretching to the intermediate layer may be uniaxial or biaxial. The preferred stretching ratio is as described above. 【0044】 The thickness of the intermediate layer is preferably 10 μm or more and 50 μm or less, and more preferably 12 μm or more and 30 μm or less. By making the thickness of the intermediate layer 10 μm or more, the strength of the laminate for packaging materials of the present invention can be further improved. By making the thickness of the intermediate layer 50 μm or less, the processability of the laminate for packaging materials of the present invention can be improved. 【0045】 In one embodiment, the intermediate layer may include a vapor-deposited film. This further improves the gas barrier properties, particularly the oxygen barrier and water vapor barrier properties, of the laminate for packaging materials of the present invention. 【0046】 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. 【0047】 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 setting the thickness of the vapor-deposited film to 1 nm or more, the oxygen barrier and water vapor barrier properties of the laminate for packaging materials of the present invention can be further improved. Furthermore, by setting the thickness of the vapor-deposited film to 150 nm or less, the occurrence of cracks in the vapor-deposited film can be prevented, and the recyclability of the laminate for packaging materials of the present invention can be improved. 【0048】 For the vapor-deposited film to be an aluminum vapor-deposited film, its OD value is preferably between 2 and 3.5. This allows for improved oxygen barrier and water vapor barrier properties while maintaining the productivity of the laminate for packaging materials of the present invention. In this invention, the OD value can be measured in accordance with JIS-K-7361. 【0049】 Deposited films can be formed 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. 【0050】 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. 【0051】 It is preferable that the surface of the deposited film is subjected to the above-mentioned surface treatment. This improves adhesion with adjacent layers. 【0052】 In one embodiment, the intermediate layer may include at least one gas barrier coating film containing a 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. Thereby, the oxygen barrier property and the water vapor barrier property of the laminate for packaging materials of the present invention can be further improved. Furthermore, when the vapor deposition film is composed of an inorganic oxide, by providing the gas barrier coating film adjacent to the vapor deposition film, the generation of cracks in the vapor deposition film can be effectively prevented. 【0053】 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.) 【0054】 As the metal atom M, for example, silicon, zirconium, titanium, aluminum, etc. can be used. Also, as the organic groups represented by R 1 and R 2 , for example, alkyl groups such as methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group and i-butyl group can be mentioned. 【0055】 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. 【0056】 Furthermore, it is preferable to use a silane coupling agent together with the above-mentioned 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. 【0057】 Two or more of the above-mentioned silane coupling agents may be used, 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 above-mentioned alkoxides. 【0058】 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. 【0059】 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 for packaging materials of the present invention 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. 【0060】 The thickness of the gas barrier coating film is preferably 0.01 μm or more and 100 μm or less, and more preferably 0.1 μm or more and 50 μm or less. 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 for packaging materials of the present invention can be improved. Furthermore, when provided adjacent to a vapor-deposited film composed of inorganic oxides, the occurrence of cracks in the vapor-deposited film can be prevented. Furthermore, by setting the thickness of the gas barrier coating film to 100 μm or less, the recyclability and processability of the laminated packaging material of the present invention can be improved. 【0061】 A gas barrier coating film can be formed by applying a composition containing the above-mentioned materials onto a substrate using conventionally known means such as roll coating (including gravure roll coaters), spray coating, spin coating, dipping, brushing, barcode application, or applicator, 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 can be improved by using 0.01 parts by mass or more of the sol-gel catalyst per 100 parts by mass of metal alkoxide. Furthermore, by using 1.0 part by mass or less of the sol-gel catalyst per 100 parts by mass of metal alkoxide, the thickness of the formed gas barrier coating film can be made uniform. 【0062】 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, are 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 silane coupling agent (e.g., silicate portion). The catalytic effect can be improved 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. Furthermore, by limiting the total molar amount of the alkoxide component (e.g., silicate portion) of the alkoxide and silane coupling agent to 0.05 moles or less, the thickness of the formed gas barrier coating film can be made uniform. 【0063】 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 the total molar amount of alkoxide, the oxygen barrier properties and water vapor barrier properties of the laminate for packaging materials of the present invention can be improved. Furthermore, by ensuring that the water content is 100 moles or more per mole of the total molar amount of alkoxide, the hydrolysis reaction can be carried out rapidly. 【0064】 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. 【0065】 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 process 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. 【0066】 (Heat seal layer) The heat seal layer is characterized by being made of the same material (same polyolefin) as the polyolefin constituting the base material and intermediate layer described above. The heat-seal layer is formed from an unstretched polyolefin resin film or by melt extrusion. 【0067】 Furthermore, when polypropylene is used as the resin constituting the heat seal layer, a heat seal modifier may be included to improve heat sealability. The heat seal modifier is not particularly limited as long as it has excellent compatibility with the polyolefin constituting the heat seal layer, but examples include olefin copolymers. 【0068】 The thickness of the heat seal layer is preferably 5 μm to 100 μm, and more preferably 10 μm to 50 μm. By making the heat seal layer thickness 5 μm or more, the heat sealability and recyclability of the heat seal layer can be improved. Furthermore, by making the heat seal layer thickness 100 μm or less, the processability of the laminate for packaging materials of the present invention can be improved. 【0069】 In one embodiment, the heat seal layer may have a multilayer structure. In particular, when a heat seal modifier is added to polypropylene as the heat seal layer, the modifier may migrate (leach out) to the gas barrier laminate side. Therefore, the heat seal layer can be made up of two or more layers, with the heat-sealed side (the innermost layer of the laminate) being a layer containing polyolefin and a heat seal modifier, and the outer layer being a layer made of polyolefin. Specifically, the multilayer structure includes a first heat-seal layer made of polyolefin and a second heat-seal layer made of polyolefin and a heat-seal modifier. 【0070】 The content of the heat seal modifier in the second heat seal layer is preferably 10% by mass or more and 50% by mass or less, and more preferably 20% by mass or more and 40% by mass or less. By setting the heat seal modifier content in the second heat seal layer to 10% by mass or more, the heat sealability of the second heat seal layer can be improved. Furthermore, by setting the heat seal modifier content in the second heat seal layer to 50% by mass or less, the recyclability of the laminate for packaging materials of the present invention can be improved. 【0071】 Furthermore, when the heat seal layer has the above-described two-layer structure, the thickness of the first heat seal layer is preferably 5 μm or more and 50 μm or less, and more preferably 7 μm or more and 45 μm or less. By setting the thickness of the first heat seal layer to 5 μm or more, the recyclability of the laminate for packaging materials of the present invention and the heat sealability of the first heat seal layer can be improved. Furthermore, by setting the thickness of the first heat seal layer to 50 μm or less, the processability of the laminate for packaging materials of the present invention can be improved. Furthermore, the thickness of the second heat seal layer is preferably 5 μm or more and 20 μm or less, and more preferably 7 μm or more and 15 μm or less. By making the thickness of the second heat seal layer 5 μm or more, the heat sealability of the second heat seal layer can be improved. Furthermore, by making the thickness of the second heat seal layer 20 μm or less, it is possible to achieve both the recyclability and processability of the laminate for packaging material of the present invention. 【0072】 (adhesive layer) The laminate for packaging materials of the present invention may include adhesive layers between the base material and the intermediate layer, and between the intermediate layer and the heat-seal layer, thereby improving the adhesion between these layers. 【0073】 The adhesive layer contains at least one type of adhesive, which may be a one-component curing type, a two-component curing type, or a non-curing type. The adhesive may be a solvent-free type or a solvent-based type, but from the viewpoint of environmental impact, a solvent-free type adhesive is preferably used. 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. 【0074】 Furthermore, if the intermediate layer includes an aluminum vapor-deposited film, it is preferable to form the adhesive layer adjacent to the vapor-deposited film using a cured product of a resin composition containing a polyester polyol, an isocyanate compound, and a phosphate-modified compound. When applying laminates with vapor-deposited films to packaging materials, bending loads are applied to the laminate by molding machines, etc., which may cause cracks in the aluminum vapor-deposited film. By using the specific adhesives described above, even if cracks occur in the aluminum vapor-deposited film, the reduction in oxygen barrier properties and water vapor barrier properties can be suppressed. 【0075】 Polyester polyols have two or more hydroxyl groups as functional groups in one molecule. Similarly, isocyanate compounds 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. 【0076】 Specific examples of resin compositions containing polyester polyols, isocyanate compounds, and phosphate-modified compounds include the PASLIM series sold by DIC Corporation. 【0077】 The resin composition may further contain plate-like inorganic compounds, coupling agents, cyclodextrins and / or their derivatives. 【0078】 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. 【0079】 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. 【0080】 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. 【0081】 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] 【0082】 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). 【0083】 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). 【0084】 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). 【0085】 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. 【0086】 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. 【0087】 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. 【0088】 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. 【0089】 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. 【0090】 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] 【0091】 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). 【0092】 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. 【0093】 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. 【0094】 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. 【0095】 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. 【0096】 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). 【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 (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). 【0098】 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. 【0099】 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. 【0100】 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. 【0101】 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. 【0102】 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. 【0103】 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. 【0104】 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. 【0105】 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. 【0106】 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. 【0107】 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. 【0108】 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 for packaging materials 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. 【0109】 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 for packaging materials 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.). 【0110】 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] 【0111】 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). 【0112】 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. 【0113】 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. 【0114】 The resin composition may contain cyclodextrin and / or its derivatives, thereby improving the adhesion of the adhesive layer. Furthermore, it can further improve the bending load resistance of the laminate for packaging materials of the present invention. 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. 【0115】 From the viewpoint of compatibility and dispersibility with resin compositions, it is preferable to use cyclodextrin derivatives as the cyclodextrin compound. 【0116】 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. 【0117】 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. 【0118】 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. 【0119】 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 increasing the thickness of the adhesive layer to 0.5 μm or more, the adhesion of the adhesive layer can be improved. Furthermore, when a cured product of a resin composition containing polyester polyol, isocyanate compound, and phosphate-modified compound is used, the bending load resistance of the laminate for packaging materials can be improved. By reducing the thickness of the adhesive layer to 6 μm or less, the processability of the laminate for packaging materials can be improved. 【0120】 The adhesive layer can be formed by applying and drying it on a substrate or the like using conventionally known methods such as the direct gravure roll coating method, gravure roll coating method, kiss coating method, reverse roll coating method, fontein method, and transfer roll coating method. 【0121】 (packaging material) The packaging material of the present invention is characterized by being composed of the above-mentioned laminate for packaging materials. The shape of the packaging material is not particularly limited, and it may be in the shape of a bag, as shown in Figure 3. 【0122】 In one embodiment, a bag-shaped packaging material can be manufactured by folding the laminate of the present invention in half and overlapping the two layers so that the heat-seal layer faces inward, and then heat-sealing the edges. In another embodiment, the bag-shaped packaging material can also be manufactured by overlapping two laminates so that their heat-seal layers face each other, and then heat-sealing the edges. Note that the shaded areas in the diagram represent the heat-sealed portions. 【0123】 The heat sealing method is not particularly limited and can be carried out by known methods such as bar seals, rotary roll seals, belt seals, impulse seals, high-frequency seals, and ultrasonic seals. 【0124】 In one embodiment, the packaging material has a stand-up pouch shape with a body and a bottom, as shown in Figure 4. 【0125】 The stand-up pouch packaging material can be manufactured by first forming the body of the laminated material by heat-sealing it in a cylindrical shape with the heat-seal layer facing inward, and then folding another laminated material in a V-shape with the heat-seal layer facing inward, sandwiching it from one end of the body, and heat-sealing it to form the bottom. 【0126】 The contents to be filled into the packaging material are not particularly limited and may be liquids, powders, or gels. They may also be food products or non-food products. After filling with contents, the opening can be heat-sealed to create a package. 【0127】 The following describes one embodiment of the present invention. The present invention relates to a laminate for packaging materials comprising at least a base material, an intermediate layer, and a heat-seal layer, wherein the base material, intermediate layer, and heat-seal layer are made of the same material, the base material and intermediate layer are subjected to a stretching treatment, and the same material is polyolefin. 【0128】 In one embodiment, the intermediate layer comprises a vapor-deposited film. 【0129】 In one embodiment, an adhesive layer is provided between the substrate and the intermediate layer, and between the intermediate layer and the heat seal layer. 【0130】 In one embodiment, the adhesive layer comprises a cured product of a resin composition containing a polyester polyol, an isocyanate compound, and a phosphate-modified compound. 【0131】 In one embodiment, the polyolefin content in the entire laminate for packaging material is 90% by mass or more. 【0132】 The packaging material of the present invention is characterized by being composed of the above-mentioned laminate. [Examples] 【0133】 The present invention will now be described in more detail with reference to examples, but the present invention is not limited to these examples. 【0134】 Example 1 As a base material, a biaxially oriented polypropylene film with a thickness of 18 μm (manufactured by Toyobo Co., Ltd., product name: P2108) was prepared. An image was formed on one side of the substrate using a gravure printing method with solvent-based gravure ink (Finato, manufactured by DIC Graphics Co., Ltd.). 【0135】 A biaxially oriented polypropylene film with a thickness of 18 μm (manufactured by Toyobo Co., Ltd., product name: P2108) was prepared, and a 30 nm thick aluminum vapor-deposited film was formed on one side of it by PVD (Physical Vapor Deposition). The vapor deposition concentration (OD value) of the formed film was measured to be 3.0. Furthermore, a polyvinyl alcohol-based barrier coating agent (MFB7010, manufactured by Michelman Co., Ltd.) was applied to the aluminum vapor-deposited film by gravure printing and dried to form a barrier coating layer with a thickness of 1 μm, thereby creating an intermediate layer. 【0136】 As the heat seal layer, polypropylene (manufactured by TPC Corporation, product name: FL7540L, density: 0.90 g / cm³) is used. 3 An unstretched polypropylene film with a thickness of 35 μm was prepared by extrusion using a T-die method with a melting point of 138°C and a melting rate of 7.0 g / 10 min. 【0137】 The printed surface of the substrate and the barrier coat layer-forming surface of the intermediate layer were laminated together using a two-component curing polyurethane adhesive (manufactured by Rock Paint Co., Ltd., product name: RU-3600 / H-689). Furthermore, the intermediate layer surface of the laminated film bonded as described above and the heat-seal layer were bonded together with the adhesive described above to obtain the laminate of the present invention. The proportion of the same polyolefin (PP) in the laminate obtained in this way was 92% by mass. 【0138】 Example 2 A laminate for packaging materials of the present invention was prepared in the same manner as in Example 1, except that the thickness of the aluminum vapor-deposited film was changed to 20 nm and the OD value of the vapor-deposited film was changed to 2.0. The proportion of the same polyolefin (PP) in the laminate for packaging materials obtained in this manner was 92% by mass. 【0139】 Example 3 A laminate for packaging materials of the present invention was prepared in the same manner as in Example 1, except that a barrier coat layer was not provided. The proportion of the same polyolefin (PP) in the laminate for packaging materials obtained in this manner was 93% by mass. 【0140】 Example 4 A two-component curing polyurethane adhesive containing polyester polyol, isocyanate compound, and phosphate-modified compound (manufactured by DIC Corporation, product name: PASLIM). A laminate for packaging materials of the present invention was prepared in the same manner as in Example 3, except that it was changed to VM001 / VM102CP. The proportion of the same polyolefin (PP) in the laminate for packaging materials obtained in this way was 92% by mass. 【0141】 Comparative Example 1 A laminate for packaging material was obtained in the same manner as in Example 1, except that an unstretched polypropylene film with a thickness of 18 μm (manufactured by Toyobo Co., Ltd., product name: P1108) was used as the base material. The proportion of identical polyolefin (PP) in the laminate obtained in this manner was 92% by mass. 【0142】 Comparative Example 2 A laminate for packaging material was obtained in the same manner as in Example 1, except that a vapor-deposited film was not applied. The proportion of the same polyolefin (PP) in the laminate obtained in this way was 92% by mass. 【0143】 Comparative Example 3 A laminate for packaging material was obtained in the same manner as in Example 1, except that the base material was a 12 μm thick biaxially oriented polyester film (manufactured by Toyobo Co., Ltd., product name: E5100). The proportion of the same polyolefin (PP) in the laminate obtained in this manner was 69% by mass. 【0144】 <<Recyclability Assessment>> The recyclability of the laminates for packaging materials obtained in the above examples and comparative examples was evaluated based on the following evaluation criteria. The evaluation results are summarized in Table 1. (Evaluation Criteria) ○: The content of the same polyolefin in the laminate for packaging materials was 80% by mass or more. ×: The content of the same polyolefin in the laminate for packaging materials was less than 80% by mass. 【0145】 <<Strength Evaluation>> The laminated packaging materials prepared in the above examples and comparative examples were tested for their strength when punctured with a 0.5 mm diameter needle using a tensile testing machine (Orientec Co., Ltd., product name: RTC-1310A). The puncture speed was set to 50 mm / min. The measurement results are summarized in Table 1. 【0146】 <<Heat Resistance Evaluation>> Two test pieces measuring 80 mm in length and 80 mm in width were prepared from the laminated packaging materials obtained in the above examples and comparative examples. Two test pieces were placed on top of each other with the heat-seal layers facing each other, and three sides were heat-sealed at 150°C to create a small pouch-shaped packaging material. The fabricated packaging materials were visually inspected, and the heat resistance of the laminated packaging material was evaluated based on the following evaluation criteria. The evaluation results are summarized in Table 1. (Evaluation Criteria) ○: No wrinkles or other defects were observed on the surface of the packaging material, and no adhesion to the heat seal bar was observed. ×: Wrinkles and other defects were present on the surface of the packaging material, and it was also found to be adhering to the heat seal bar, making it impossible to form bags. 【0147】 <<Printability Evaluation>> In the above examples and comparative examples, the images formed on the substrates were visually observed, and their printability was evaluated based on the following evaluation criteria. The evaluation results are summarized in Table 1. (Evaluation Criteria) ○: The dimensional stability during printing was good, and a good image was formed without smudging or bleeding. ×: The film stretched or contracted during printing, resulting in smudging or blurring of the resulting image. 【0148】 <<Oxygen Barrier Assessment>> The laminated packaging material obtained in the above examples and comparative examples was cut to A4 size, and the oxygen permeability (cc / m³) was measured using OXTRAN2 / 20 manufactured by MOCON, Inc., USA, in an environment of 23°C and 90% relative humidity. 2 The / day / atm (atm) was measured. The measurement results are summarized in Table 1. Note that the measurement limit is 200 cc / m³. 2 For amounts exceeding / day / atm, "-" is indicated. 【0149】 <<Evaluation of water vapor barrier properties>> The laminates obtained in the above examples and comparative examples were cut to A4 size, and the water vapor transmission rate (g / m³) was measured using PERMATRAN3 / 31 manufactured by MOCON, Inc., USA, in an environment of 40°C and 90% relative humidity. 2 The / day / atm (atm) was measured. The measurement results are summarized in Table 1. 【0150】 <Bending load resistance evaluation> The laminated packaging material obtained above was subjected to a flex load (stroke: 155 mm, flexing motion: 440°) five times using a Gelboflex teter (manufactured by Tester Industries Co., Ltd., product name: BE1006BE) in accordance with ASTM F 392. After bending, the oxygen and water vapor permeability of the laminate was measured. The measurement results are summarized in Table 1. 【0151】 <<Heat sealability test>> The laminated packaging material obtained in the above examples and comparative examples was cut into 10cm x 10cm pieces to create sample pieces. These sample pieces were folded in half with the heat-seal layer facing inward, and the temperature was set to 150°C and the pressure to 1kgf / cm². 2 A 1cm x 10cm area was heat-sealed under a 1-second condition. The heat-sealed sample pieces were cut into 15mm wide strips, and the unheat-sealed ends were gripped in a tensile testing machine. The peel strength (N / 15mm) was measured under conditions of a speed of 300mm / min and a load range of 50N. The measurement results are summarized in Table 1. In Comparative Example 1, the laminated packaging material obtained adhered to the heat seal bar, making it impossible to measure the peel strength, therefore it was marked as "-". 【0152】 [Table 1] [Explanation of symbols] 【0153】 10: Laminate for packaging materials, 11: Base material, 12: Intermediate layer, 13: Heat seal layer, 14: Adhesive layer

Claims

[Claim 1] A laminate for packaging material comprising, in this order, a base material, a first adhesive layer containing an adhesive, an intermediate layer, a second adhesive layer containing an adhesive, and a heat seal layer, The substrate is a biaxially oriented polypropylene film. The intermediate layer comprises a biaxially oriented polypropylene film and a vapor-deposited film, and a gas barrier coating film is provided adjacent to the vapor-deposited film, wherein the gas barrier coating film contains at least one resin composition of a hydrolyzed metal alkoxide or a hydrolyzed condensate of a metal alkoxide obtained by polycondensation of a mixture of a metal alkoxide and a water-soluble polymer (except for the gas barrier coating film further containing an inorganic layered compound). The heat-seal layer is an unstretched polypropylene film. The aforementioned adhesive is a urethane-based adhesive. The biaxially oriented polypropylene film of the base material and the biaxially oriented polypropylene film of the intermediate layer are formed separately. A laminate for packaging materials, characterized in that the polypropylene content in the entire laminate for packaging materials is 80% by mass or more. [Claim 2] The laminate for packaging material according to claim 1, wherein an image is formed on the surface of the substrate on the first adhesive layer side. [Claim 3] A packaging material comprising a laminate for packaging materials according to claim 1 or 2. [Claim 4] A packaging bag comprising the packaging material described in claim 3. [Claim 5] A method for manufacturing laminates for packaging materials, The laminate for packaging material comprises, in this order, at least, a base material, a first adhesive layer containing an adhesive, an intermediate layer, a second adhesive layer containing an adhesive, and a heat seal layer. The substrate is a biaxially oriented polypropylene film. The intermediate layer comprises a biaxially oriented polypropylene film and a vapor-deposited film, and a gas barrier coating film is provided adjacent to the vapor-deposited film, wherein the gas barrier coating film contains at least one resin composition of a hydrolyzed metal alkoxide or a hydrolyzed condensate of a metal alkoxide obtained by polycondensation of a mixture of a metal alkoxide and a water-soluble polymer (except for the gas barrier coating film further containing an inorganic layered compound). The heat-seal layer is an unstretched polypropylene film. The aforementioned adhesive is a urethane-based adhesive. The polypropylene content in the entire laminate for packaging material is 80% by mass or more. The process of bonding the substrate and the intermediate layer with the adhesive to form the first adhesive layer and obtain a laminated film, A step of forming the second adhesive layer by bonding the intermediate layer side of the laminated film and the heat seal layer with the adhesive to obtain a laminate for packaging material, A method for manufacturing a laminate for packaging materials, characterized by having the following features. [Claim 6] The method for manufacturing a laminate for packaging materials according to claim 5, wherein the step of obtaining the laminate for packaging materials is to form the second adhesive layer by bonding the biaxially oriented polypropylene film of the intermediate layer and the heat seal layer with the adhesive. [Claim 7] A method for manufacturing a laminate for packaging material according to claim 5 or 6, further comprising the step of forming an image on the surface of the substrate on the first adhesive layer side. [Claim 8] A method for manufacturing a laminate for packaging materials according to any one of claims 5 to 7, wherein the adhesive contained in the first adhesive layer and the second adhesive layer is a solvent-free adhesive.

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