Barrier film, laminate, and packaging bag

Abstract

The barrier film of one aspect of the present disclosure successively has a substrate layer containing polypropylene, an evaporation layer containing an inorganic oxide, and a gas barrier layer, the substrate layer has a multilayer structure having at least three layers of a first surface layer, a core layer, and a second surface layer in this order, and when the softening temperature of each layer of the substrate layer is measured by local thermal analysis (LTA), the first surface layer has at least one softening temperature of 120°C or higher, the core layer has at least one softening temperature of 190°C or higher, and the second surface layer has at least one softening temperature of 160°C or lower.

Description

Technical Field

[0001] This disclosure relates to barrier films, laminates, and packaging bags. Background Technology

[0002] Barrier films are widely used as packaging materials for food and pharmaceuticals that undergo heat sterilization processes such as boiling and high-temperature cooking. When packaging these contents, minimizing oxygen permeability is particularly important. For barrier films used in this type of heat sterilization packaging, the base material is typically a heat-resistant polyethylene terephthalate (PET) film.

[0003] However, in recent years, due to increasing awareness of environmental issues, there has been growing attention on so-called single-material packaging materials that use a single raw material in order to make packaging materials suitable for recycling. As the sealant layer of packaging materials, olefin-based films such as polypropylene are generally used. Therefore, in order to use such a sealant layer to manufacture single-material packaging materials, it is required that polypropylene also be used as the base material in the barrier film. For example, single-material packaging materials using polypropylene are proposed in Patent Documents 1 and 2 below.

[0004] Polypropylene (PP) films are widely used in packaging materials due to their excellent transparency, mechanical strength, and heat resistance. However, unlike polyethylene terephthalate (PET), PP lacks secondary processing properties such as metal vapor deposition, adhesion to other resins, and printability. Various methods have been proposed to address these issues. For example, Patent Document 3 proposes a PP-based film formed from a blend of PP and ethylene-α-olefin copolymer, and Patent Document 4 proposes a PP-based film having a layer formed from a blend of PP and ethylene-α-olefin copolymer and a layer formed from a PP resin.

[0005] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2020-40257 Patent Document 2: Japanese Patent Application Publication No. 2021-20391 Patent Document 3: Japanese Patent Application Publication No. 63-291929 Patent Document 4: Japanese Patent Application Publication No. 63-290743 Summary of the Invention

[0006] The technical problem that the invention aims to solve However, existing barrier films or laminates not only have the problem of failing to suppress oxygen permeability to a very low level after heat sterilization, but also have the problem of low interlayer (membrane) sealing strength after heat sterilization, resulting in low bag tear strength when used as a bag filled with contents, and easy damage to the bag due to impacts such as falling.

[0007] This disclosure was made in view of the foregoing facts, and its purpose is to provide a barrier film that can suppress oxygen permeability to a very low level after heat sterilization and can also provide sufficient interlayer (layer) adhesion strength after heat sterilization, a laminate using the barrier film, and a packaging bag.

[0008] Means for solving technical problems (First aspect) This disclosure provides a barrier film comprising a substrate layer containing polypropylene, a vapor-deposited layer containing inorganic oxides, and a gas barrier layer. The substrate layer has a multilayer structure comprising at least a first surface layer, a core layer, and a second surface layer. When the softening temperature of each layer of the substrate layer is determined by local thermal analysis (LTA), the first surface layer has at least one softening temperature above 120°C, the core layer has at least one softening temperature above 190°C, and the second surface layer has at least one softening temperature below 160°C.

[0009] According to the above-described barrier film, by having a first surface layer, a core layer, and a second surface layer with softening temperatures within the aforementioned specific range in the substrate layer, the adhesion strength between the layers constituting the substrate layer and the barrier film can be improved. Oxygen permeability can be suppressed to a very low level after heat sterilization, and sufficient adhesion strength between the films (layers) can be maintained after heat sterilization. Furthermore, when the above-described barrier film is laminated with a sealant layer or a sealant layer and a second substrate layer to form a laminate, the adhesion strength between the barrier film and the sealant layer and / or the second substrate layer can be improved. Therefore, by using the above-described barrier film, a laminate that suppresses oxygen permeability to a very low level after heat sterilization and maintains sufficient adhesion strength between the films (layers) after heat sterilization, and a packaging bag using this laminate, can be obtained.

[0010] In the aforementioned barrier membrane, at least one softening temperature exists between 120°C and 170°C when the softening temperature of the first surface layer is measured using LTA. In this case, the oxygen permeability of the barrier membrane can be suppressed to a lower level after heat sterilization, and the membranes can also achieve a more sufficient seal strength after heat sterilization.

[0011] In the aforementioned barrier membrane, at least one softening temperature exists between 120°C and 160°C when the softening temperature of the second surface layer is measured using LTA. In this case, the oxygen permeability of the barrier membrane can be suppressed to a lower level after heat sterilization, and the membranes can also achieve a more sufficient seal strength after heat sterilization.

[0012] In the aforementioned barrier membrane, the first and second surface layers may comprise a copolymer of propylene and α-olefin. In this case, the barrier membrane can further reduce oxygen permeability after heat sterilization and also achieve a stronger inter-membrane bond after heat sterilization.

[0013] In the aforementioned barrier film, when the softening temperature of each layer of the substrate layer is measured using LTA, the core layer may have a softening temperature that is higher than that of either the first or second surface layer. In this case, the barrier film can also suppress oxygen permeability to an even lower level after heat sterilization treatment.

[0014] In the aforementioned barrier film, when the softening temperature of each layer of the substrate layer is measured using LTA, the softening temperature of the first surface layer is higher than that of any of the softening temperatures present in the second surface layer. In this case, the oxygen permeability of the barrier film can be suppressed to an even lower level after heat sterilization. Furthermore, when the barrier film is laminated with a sealant layer or a sealant layer and a second substrate layer to form a laminate, the adhesion strength between the barrier film and the sealant layer and / or the second substrate layer can be further improved.

[0015] In the aforementioned barrier membrane, the thickness of both the first and second surface layers can be less than 2.0 μm. In this case, the oxygen permeability of the barrier membrane can be further suppressed after heat sterilization, and the membranes can also achieve a more sufficient seal strength after heat sterilization.

[0016] In the aforementioned barrier membrane, the vapor-deposited layer may include at least one selected from alumina and silicon oxide. In this case, the oxygen permeability of the barrier membrane can be further suppressed after heat sterilization, and the membranes can also achieve a more sufficient adhesion strength after heat sterilization.

[0017] In the aforementioned barrier membrane, the gas barrier layer may comprise a water-soluble polymer with hydroxyl groups, and at least one selected from metal alkoxides, silane coupling agents, and their hydrolysates. In this case, the barrier membrane can further suppress oxygen permeability after heat sterilization, and also achieve a more sufficient seal strength between membranes after heat sterilization.

[0018] In the aforementioned barrier film, the vapor-deposited layer can be formed on the surface of the first surface layer opposite to the core layer. Furthermore, the barrier film can have an anchor coating between the first surface layer and the vapor-deposited layer. The barrier film with this configuration can further improve the adhesion strength between the first surface layer and the vapor-deposited layer. Therefore, after heat sterilization, the oxygen permeability of the barrier film can be suppressed to a lower level, and the adhesion strength between the membranes can be improved after heat sterilization.

[0019] This disclosure also provides a laminate comprising the barrier film and sealant layer described above, the sealant layer comprising a polyolefin. The laminate may further comprise a second substrate layer, comprising a polyolefin, on the side of the barrier film opposite to the sealant layer. Because the laminate uses the barrier film described above, oxygen permeability can be suppressed to a lower level after heat sterilization, and sufficient inter-film adhesion strength can be achieved after heat sterilization. Furthermore, the laminate is useful as a single-material packaging material.

[0020] This disclosure also provides a packaging bag manufactured by forming the laminated body described above. Because the packaging bag uses the laminated body described above, oxygen permeability can be suppressed to a very low level after heat sterilization, and sufficient sealing strength can be achieved between the films after heat sterilization. Furthermore, the packaging bag is useful as a single-material packaging material.

[0021] (Second aspect) This disclosure provides a barrier film comprising a substrate layer containing polypropylene, an evaporated layer containing inorganic oxides, and a gas barrier layer. The substrate layer is formed of two layers, a surface layer and a core layer, which are sequentially arranged from the evaporated layer side. When the softening temperature of each layer of the substrate layer is determined by local thermal analysis (LTA), the surface layer has at least one softening temperature between 115°C and 170°C, and the core layer has at least one softening temperature above 190°C.

[0022] According to the above-described barrier film, the substrate layer, by having the surface layer and the core layer having softening temperatures within the aforementioned specific range, can improve the inter-film adhesion strength, suppress oxygen permeability to a very low level after heat sterilization, and maintain sufficient inter-film adhesion strength after heat sterilization. Therefore, by using the above-described barrier film, a laminate that suppresses oxygen permeability to a very low level after heat sterilization and maintains sufficient inter-film adhesion strength after heat sterilization, and a packaging bag using the laminate, can be obtained.

[0023] In the aforementioned barrier membrane, the surface layer may comprise a copolymer of propylene and α-olefin. In this case, the barrier membrane can further suppress oxygen permeability after heat sterilization, and also achieve a stronger inter-membrane bond after heat sterilization.

[0024] In the aforementioned barrier membrane, the surface layer may contain an ethylene-1-butene-propylene random copolymer. In this case, the barrier membrane can also suppress oxygen permeability to an even lower level after heat sterilization treatment.

[0025] In the aforementioned barrier membrane, the thickness of the surface layer can be 0.2 μm or more and 2.0 μm or less. In this case, the barrier membrane can suppress oxygen permeability to a very low level after heat sterilization treatment, and the membrane can also have a more sufficient sealing strength after heat sterilization treatment.

[0026] In the aforementioned barrier membrane, the ratio of the thickness of the surface layer to the thickness of the core layer can be 1 / 100 to 1 / 5. In this case, the oxygen permeability of the barrier membrane can be suppressed to a lower level after heat sterilization, and the membrane can also have a more sufficient sealing strength after heat sterilization.

[0027] In the aforementioned barrier membrane, the vapor-deposited layer may include at least one selected from alumina and silicon oxide. In this case, the oxygen permeability of the barrier membrane can be further suppressed after heat sterilization, and the membranes can also achieve a more sufficient adhesion strength after heat sterilization.

[0028] In the aforementioned barrier membrane, the gas barrier layer may be composed of materials selected from Si (OR) 1 )4 and R 2 Si(OR) 3 3 (OR) 1 and OR 3 Each is an independent hydrolyzable group, R 2 The coating solution is formed from at least one silicon compound (or its hydrolysate) containing an organic functional group and a water-soluble polymer having a hydroxyl group. In this case, the barrier membrane can further suppress oxygen permeability after heat sterilization, and also achieve a more sufficient adhesion strength between membranes after heat sterilization.

[0029] In the aforementioned barrier film, an anchor coating may be provided between the surface layer and the vapor-deposited layer. The barrier film with this configuration can further improve the adhesion strength between the surface layer and the vapor-deposited layer. Therefore, after heat sterilization, the oxygen permeability of the barrier film can be suppressed to a lower level, and the adhesion strength between the films can also be improved after heat sterilization.

[0030] This disclosure also provides a laminate comprising the barrier film and sealant layer described above, the sealant layer comprising a polyolefin. The laminate may further comprise a second substrate layer, comprising a polyolefin, on the side of the barrier film opposite to the sealant layer. Because the laminate uses the barrier film described above, oxygen permeability can be suppressed to a very low level after heat sterilization, and sufficient inter-film adhesion strength can be achieved after heat sterilization. Furthermore, the laminate is useful as a single-material packaging material.

[0031] This disclosure also provides a packaging bag manufactured by forming the laminated body described above. Because the packaging bag uses the laminated body described above, oxygen permeability can be suppressed to a very low level after heat sterilization, and sufficient sealing strength can be achieved between the films after heat sterilization. Furthermore, the packaging bag is useful as a single-material packaging material.

[0032] Invention Effects According to this disclosure, a barrier film that can suppress oxygen permeability to a very low level after heat sterilization and that can also provide sufficient interlayer (layer) sealing strength after heat sterilization, a laminate using the barrier film, and a packaging bag can be provided. Attached Figure Description

[0033] Figure 1 This is a schematic cross-sectional view illustrating a barrier film according to one embodiment of the present disclosure.

[0034] Figure 2 This is a schematic cross-sectional view illustrating a barrier film according to one embodiment of the present disclosure.

[0035] Figure 3 This is a schematic cross-sectional view illustrating a laminate according to one embodiment of the present disclosure.

[0036] Figure 4 This is a schematic cross-sectional view illustrating a laminate according to one embodiment of the present disclosure.

[0037] Figure 5 This is a schematic cross-sectional view illustrating a laminate according to one embodiment of the present disclosure.

[0038] Figure 6 This is a schematic cross-sectional view illustrating a laminate according to one embodiment of the present disclosure. Detailed Implementation

[0039] The following is an example, please refer to the appendix as needed. Figure 1 The embodiments of this disclosure will be described in detail below. However, this disclosure is not limited to the following embodiments.

[0040] This disclosure provides the following barrier films, laminates, and packaging bags.

[0041] [1] A barrier film comprising, in sequence, a substrate layer comprising polypropylene, a vapor-deposited layer comprising inorganic oxide, and a gas barrier layer, wherein the substrate layer has a multilayer structure comprising at least a first surface layer, a core layer and a second surface layer in sequence, wherein when the softening temperature of each layer of the substrate layer is determined by local thermal analysis (LTA), the first surface layer has at least one softening temperature above 120°C, the core layer has at least one softening temperature above 190°C, and the second surface layer has at least one softening temperature below 160°C.

[0042] [2] According to the barrier film described in [1] above, when the softening temperature of the first surface layer is measured by LTA, there is at least one softening temperature between 120°C and 170°C.

[0043] [3] According to the barrier film described in [1] or [2] above, when the softening temperature of the second surface layer is determined by LTA, there is at least one softening temperature between 120°C and 160°C.

[0044] [4] The barrier film according to any one of [1] to [3] above, wherein the first surface layer and the second surface layer comprise a copolymer of propylene and α-olefin.

[0045] [5] According to any one of [1] to [3] above, the barrier film wherein, when the softening temperature of each layer of the substrate layer is measured by LTA, the core layer has a softening temperature that is higher than any softening temperature present in the first surface layer and the second surface layer.

[0046] [6] According to any one of [1] to [5] above, the barrier film wherein, when the softening temperature of each layer of the substrate layer is measured by LTA, the first surface layer has a softening temperature that is higher than any softening temperature present in the second surface layer.

[0047] [7] The barrier film according to any one of [1] to [6] above, wherein the thickness of the first surface layer and the second surface layer is 2.0 μm or less.

[0048] [8] The barrier film according to any one of [1] to [7] above, wherein the vapor-deposited layer comprises at least one selected from alumina and silicon oxide.

[0049] [9] The barrier membrane according to any one of [1] to [8] above, wherein the gas barrier layer comprises a water-soluble polymer having hydroxyl groups and at least one selected from metal alkoxides, silane coupling agents and their hydrolysates.

[0050]

[10] The barrier film according to any one of [1] to [9] above, wherein the vapor-deposited layer is formed on the surface of the first surface layer opposite to the core layer.

[0051]

[11] According to the barrier film described in

[10] above, an anchor coating is provided between the first surface layer and the vapor-deposited layer.

[0052]

[12] A barrier film comprising, in sequence, a substrate layer comprising polypropylene, an evaporated layer comprising inorganic oxide, and a gas barrier layer, wherein the substrate layer is formed of two layers, a surface layer and a core layer, in sequence from the evaporated layer side, wherein when the softening temperature of each layer of the substrate layer is determined by local thermal analysis (LTA), the surface layer has at least one softening temperature between 115°C and 170°C, and the core layer has at least one softening temperature between 190°C and 190°C.

[0053]

[13] According to the barrier film described in

[12] above, wherein the surface layer comprises a copolymer of propylene and α-olefin.

[0054]

[14] According to the barrier film described in

[12] or

[13] above, wherein the surface layer comprises an ethylene-1-butene-propylene random copolymer.

[0055]

[15] The barrier film according to any one of

[12] to

[14] above, wherein the thickness of the surface layer is 0.2 μm or more and 2.0 μm or less.

[0056]

[16] The barrier film according to any one of

[12] to

[15] above, wherein the ratio of the thickness of the surface layer to the thickness of the core layer is 1 / 100 to 1 / 5.

[0057]

[17] The barrier film according to any one of

[12] to

[16] above, wherein the vapor-deposited layer comprises at least one selected from alumina and silicon oxide.

[0058]

[18] The barrier membrane according to any one of

[12] to

[17] above, wherein the gas barrier layer comprises a material containing Si (OR) 1 )4 and R 2 Si(OR) 3 3 (OR) 1 and OR 3 Each is an independent hydrolyzable group, R 2 A coating solution is formed from at least one silicon compound (or its hydrolysate) containing an organic functional group and a water-soluble polymer having a hydroxyl group.

[0059]

[19] The barrier film according to any one of

[12] to

[18] above, wherein an anchor coating is provided between the surface layer and the vapor-deposited layer.

[0060]

[20] A laminate comprising a barrier film and a sealant layer as described in any one of [1] to

[19] above, wherein the sealant layer comprises a polyolefin.

[0061]

[21] According to the laminate described in

[20] above, a second substrate layer is further provided on the surface of the barrier film opposite to the sealant layer, the second substrate layer comprising polyolefin.

[0062]

[22] A packaging bag is made by forming the laminated body described in

[20] or

[21] above.

[0063] <First aspect barrier membrane> The first aspect of the barrier film sequentially comprises a substrate layer containing polypropylene, a vapor-deposited layer containing inorganic oxides, and a gas barrier layer. The substrate layer has a multilayer structure having at least three layers in sequence: a first surface layer, a core layer, and a second surface layer. When the softening temperature of each layer of the substrate layer is determined by local thermal analysis (LTA), the first surface layer has at least one softening temperature above 120°C, the core layer has at least one softening temperature above 190°C, and the second surface layer has at least one softening temperature below 160°C.

[0064] Figure 1 This is a schematic cross-sectional view showing the barrier film of the first aspect of this embodiment. (See attached image.) Figure 1 As shown, the barrier film 10a of this embodiment sequentially comprises a substrate layer 1a, a vapor-deposited layer 2, and a gas barrier layer 3.

[0065] [Substrate Layer] The substrate layer 1a is a membrane (base membrane) that serves as a support and comprises polypropylene. The substrate layer 1a is a multilayer membrane comprising at least three layers: a first surface layer 11a, a core layer 12, and a second surface layer 13. The substrate layer 1a can be a membrane formed from polypropylene, or it can be a membrane formed by sheeting polypropylene and stretching the sheet using conventional methods to achieve uniaxial or biaxial orientation. Stretching can also be performed on multilayer membranes. Known additives can also be added to the substrate layer 1a, depending on the purpose, such as organic additives like antioxidants, stabilizers, calcium stearate, fatty acid amides, erucamides, lubricants, and antistatic agents, and inorganic additives like silica, zeolite, sylate, hydrotalcite, and silicon particles.

[0066] There are no particular limitations on the thickness (total thickness) of the substrate layer 1a. For example, it can be 3μm or more and 200μm or less, 6μm or more and 50μm or less, or 10μm or more and 30μm or less.

[0067] The core layer 12 is a layer that has at least one softening temperature above 190°C when the softening temperature is determined by local thermal analysis (LTA) of the film cross-section, as described later. The aforementioned at least one softening temperature can be above 195°C, or above 198°C and below 220°C. The softening temperature is measured at the center of the core layer 12 in the thickness direction. By having at least one softening temperature above 190°C, the heat resistance of the substrate layer 1a can be improved, and it can withstand the heat during heat sterilization treatment, thereby preventing the substrate layer 1a from shrinking during heat sterilization treatment and becoming unusable as a packaging material. Furthermore, the core layer 12 can be a layer with one softening temperature or a layer with multiple softening temperatures. When the core layer 12 has multiple softening temperatures, at least one softening temperature needs to satisfy the above conditions.

[0068] From the viewpoint of improving the heat resistance of the substrate layer 1a, the polypropylene used in the core layer 12 can be crystalline polypropylene. From the viewpoint of further improving the heat resistance for heat sterilization treatment, it can be homopolymer polypropylene. However, as long as it does not significantly impair the effects of this disclosure, random copolymers of propylene and α-olefins, or mixtures of said copolymers and homopolymer polypropylene, etc., can also be used.

[0069] A first surface layer 11a is provided on one side of the core layer 12, and a second surface layer 13 is provided on the other side. Both surfaces of the substrate layer 1a can be formed by the first surface layer 11a and the second surface layer 13. Other layers besides these can be provided between the core layer 12 and the first surface layer 11a, or the core layer 12 can be in contact with the first surface layer 11a without any other layers in between. Similarly, other layers besides these can be provided between the core layer 12 and the second surface layer 13, or the core layer 12 can be in contact with the second surface layer 13 without any other layers in between.

[0070] The first surface layer 11a is a layer that has at least one softening temperature above 120°C when the softening temperature is determined by local thermal analysis (LTA) of the film cross-section, as described later. The aforementioned at least one softening temperature can be above 120°C and below 170°C, or above 125°C and below 168°C. The softening temperature is measured at the center of the first surface layer 11a in the thickness direction. With at least one softening temperature above 120°C, the heat resistance of the first surface layer 11a will not become too low, and the risk of softening during heat sterilization treatment, leading to reduced adhesion or deterioration of barrier properties, is low. Furthermore, with at least one softening temperature below 170°C, the reduction in the flexibility of the first surface layer 11a can be suppressed, and the adhesion strength between the first surface layer 11a and the core layer 12 can be improved. Moreover, the first surface layer 11a can be a layer with one softening temperature, or it can be a layer with multiple softening temperatures. When the first surface layer 11a has multiple softening temperatures, at least one softening temperature that satisfies the above conditions is sufficient.

[0071] The second surface layer 13 is a layer that has at least one softening temperature below 160°C when the softening temperature is determined by the membrane cross-section using local thermal analysis (LTA) described later. The aforementioned at least one softening temperature can be 120°C or higher and 160°C or lower, or 122°C or higher and 155°C or lower. The softening temperature is measured at the center of the second surface layer 13 in the thickness direction. By having at least one softening temperature below 160°C, the reduction in the flexibility of the second surface layer 13 can be suppressed, and the adhesion strength between the second surface layer 13 and the core layer 12 can be improved. Furthermore, by having at least one softening temperature above 120°C, the heat resistance of the second surface layer 13 will not become too low, and the risk of softening of the second surface layer 13 during heat sterilization treatment, leading to a decrease in adhesion or deterioration of barrier properties, is reduced. In addition, the second surface layer 13 can be a layer with one softening temperature or a layer with multiple softening temperatures. When the second surface layer 13 has multiple softening temperatures, at least one softening temperature that satisfies the above conditions is sufficient.

[0072] The polypropylene used in the first outer layer 11a and the second outer layer 13, from the viewpoint of improving adhesion to the core layer 12, may contain copolymers of propylene and other monomers. Other monomers may include, for example, α-olefins such as ethylene, 1-butene, and 1-hexene. The copolymer may be a random copolymer.

[0073] To improve the rigidity and self-standing properties of single-material packaging materials using polypropylene film, they generally have a three-layer structure: an outer film (second substrate layer), a barrier film, and a sealant layer. In the barrier film 10a of this embodiment, a second surface layer 13 is provided on the surface opposite to the barrier forming surface (the side where the vapor-deposited layer and gas barrier layer are formed) of the substrate layer 1a to improve the lamination strength with adjacent layers (the second substrate layer or the sealant layer). The second surface layer 13 has a softening temperature of 160°C or lower. Because the second surface layer 13 has a softening temperature of 160°C or lower, its flexibility is improved, resulting in good adhesion strength with the core layer 12.

[0074] Regarding the softening temperature of each layer, in order to reduce the shrinkage of the substrate layer 1a during heat sterilization and maintain the adhesion strength between the layers, it is preferable to set the core layer 12 to the highest softening temperature. In other words, it is preferable that the core layer 12 has a softening temperature that is higher than either the softening temperature of the first surface layer 11a or the second surface layer 13. Furthermore, regarding the softening temperatures of the first surface layer 11a and the second surface layer 13, for the reason of easily maintaining a balance between the barrier properties and the adhesion between the layers after heat sterilization, it is preferable that the softening temperature of the first surface layer 11a is higher than the softening temperature of the second surface layer 13. In other words, it is preferable that the first surface layer 11a has a softening temperature that is higher than either the softening temperature of the second surface layer 13.

[0075] The softening temperature of the core layer 12, which is above 190°C, can be at least 10°C higher, and at least 20°C higher, than the softening temperature of the first surface layer 11a, which is above 120°C. This allows for further reduction of the shrinkage of the substrate layer 1a during heat sterilization and more adequate maintenance of the interlayer bonding strength after heat sterilization.

[0076] The softening temperature of the core layer 12, which is above 190°C, can be at least 35°C higher, and at least 45°C higher, than the softening temperature of the second surface layer 13, which is below 160°C. This allows for further reduction of the shrinkage of the substrate layer 1a during heat sterilization and more adequate maintenance of the interlayer bonding strength after heat sterilization.

[0077] The softening temperature of the first surface layer 11a, which is above 120°C, can be at least 5°C higher, and possibly at least 15°C higher, than the softening temperature of the second surface layer 13, which is below 160°C. This makes it easier to maintain a more adequate balance between the barrier properties and the interlayer seal after heat sterilization.

[0078] There are no particular limitations on the method for adjusting the softening temperature of the first surface layer 11a, the core layer 12, and the second surface layer 13. The softening temperature of each layer can be adjusted, for example, by adjusting the type of resin constituting each layer, their mixing ratio when using multiple resins, the monomer ratio when using copolymers, and the manufacturing method of each layer.

[0079] The thickness of both the first surface layer 11a and the second surface layer 13 can be 0.1 μm or more. If this thickness is 0.1 μm or more, the first surface layer 11a, the core layer 12, and the second surface layer 13 can be uniformly stacked, suppressing uneven thicknesses of the first surface layer 11a and the second surface layer 13. Furthermore, it is believed that this sufficiently mitigates the stress on the vapor-deposited layer during heat sterilization, suppressing degradation of barrier properties. From this perspective, the thickness of the first surface layer 11a and the second surface layer 13 is preferably 0.3 μm or more. On the other hand, there is no particular upper limit to the thickness of the first surface layer 11a and the second surface layer 13; however, from the viewpoint of more sufficiently ensuring the overall heat resistance of the substrate layer 1a, it is preferably 2.0 μm or less, and more preferably 1.8 μm or less.

[0080] The thickness of the core layer 12 can be greater than 2μm, greater than 10μm, or greater than 15μm, and can be less than 150μm, less than 50μm, or less than 20μm.

[0081] The ratio of the thickness of the first surface layer 11a to the thickness of the core layer 12 (thickness of the first surface layer 11a / thickness of the core layer 12) can be 1 / 100 to 1 / 5, or 1 / 70 to 1 / 10. If the thickness ratio is within the above range, the overall heat resistance of the substrate layer 1a can be more fully ensured, and the adhesion between the layers in the barrier film and the laminate can be further improved.

[0082] The ratio of the thickness of the second surface layer 13 to the thickness of the core layer 12 (thickness of the second surface layer 13 / thickness of the core layer 12) can be 1 / 100 to 1 / 5, or 1 / 70 to 1 / 10. If the thickness ratio is within the above range, the overall heat resistance of the substrate layer 1a can be more fully ensured, and the adhesion between the layers in the barrier film and the laminate can be further improved.

[0083] The thickness of the first surface layer 11a and the thickness of the second surface layer 13 can be the same or different. The thickness of the first surface layer 11a can be less than or equal to the thickness of the second surface layer 13. The ratio of the thickness of the first surface layer 11a to the thickness of the second surface layer 13 (thickness of the first surface layer 11a / thickness of the second surface layer 13) can be 1 / 5 to 1 / 0.5, or 1 / 3 to 1 / 1. If the thickness ratio is within the above range, the overall heat resistance of the substrate layer 1a can be more fully ensured, and the adhesion between the layers in the barrier film and the laminate can be further improved.

[0084] The polypropylene (comprising copolymers of propylene and other monomers) used in the substrate layer 1a can be recycled resin or resin obtained by polymerizing biomass-derived raw materials such as plants. These resins can be used alone or in combination with resins polymerized from conventional fossil fuels.

[0085] [Cross-section processing method for specimens used in softening temperature determination] In this embodiment, the softening temperature of the substrate layer is measured from a cross-section of the substrate layer. To prevent the embedding resin from peeling off after embedding, the substrate layer may undergo corona treatment as a surface treatment on its front and back surfaces. Furthermore, the sample used for softening temperature measurement may not be limited to the substrate layer state; a barrier film or a laminate state may also be used.

[0086] After surface treatment of the front and back sides of the substrate layer, the substrate layer is cut and embedded using a razor in a strip or wedge shape. A light-curing resin is used as the embedding resin, and it is cured by light irradiation after embedding. For example, D-800 (trade name) manufactured by Toa Synthetic Co., Ltd. can be used as the light-curing resin. Next, the cured sample is fixed in place with the embedded resin using an AFM sample holder insert. The substrate layer is trimmed and its cross-section is cut using a glass cutter at room temperature (25°C), and then the cross-section is cut using a diamond cutter at a low temperature (-140°C) until a mirror finish is achieved. The cross-section cutting using the diamond cutter is performed, for example, at a cutting speed of 1.0 mm / s and a cutting film thickness of 100 nm. The cross-section-processed sample, fixed in place using an AFM sample holder insert, is used for softening temperature measurement. For example, the Ultramicrotome EM UC7 (trade name) or CryoSystem EMFC7 (trade name) manufactured by Leica can be used for cross-section cutting. Furthermore, the cutting direction is parallel to the layer interface.

[0087] [Method for determining softening temperature] The softening temperature refers to the temperature at which a substance, such as a resin, exhibits softening behavior. In this embodiment, the softening temperature is evaluated using localized thermal analysis (LTA) with atomic force microscopy. The sample is heated by applying a voltage to a cantilever equipped with a heater. In LTA, after the shape of the sample is measured, a certain force (pressure) is applied to the sample surface at a specified location using the cantilever. Heating is performed while maintaining a constant pressure, and the temperature at which the height position (Z-displacement) of the cantilever changes due to the change in surface hardness before and after heating is calculated as the softening temperature. The change in the height position of the cantilever refers to the change caused by the vertical rise of the cantilever due to thermal expansion of the sample surface and the vertical fall of the cantilever due to softening of the sample surface. By converting the applied voltage of the heater of the cantilever at the time this change in cantilever height position occurs into temperature, the localized softening temperature near the surface in the nanoscale region can be determined.

[0088] The apparatus used was the MFP-3D-SA (trade name), an atomic force microscope (AFM) manufactured by Oxford Instruments, and the Ztherm as a local thermal analysis option. Shape measurements were performed in AC mode (tapping mode), and softening temperature measurements were performed in contact mode.

[0089] The cantilever uses Anasys Instruments AN2-200 (trade name) springs with a spring constant of 0.5~3.5 N / m.

[0090] The voltage application rate (heating rate) of the cantilever in the determination of softening temperature is 0.5V / second.

[0091] In Ztherm, the contact pressure (change in the deflection of the cantilever) is controlled to be constant for measurement. However, since the deflection of the cantilever changes with the applied voltage even when it is not in contact with the sample, the contact pressure control needs to be performed after subtracting the deflection caused by the applied voltage. Ztherm has a Detrend correction function that acquires the change in the deflection of the cantilever relative to the applied voltage. Detrend correction is performed by applying the maximum applied voltage used for measurement to the cantilever when the cantilever is not in contact with the sample surface. In this embodiment, after shape measurement and before softening temperature measurement, Detrend correction is performed at the maximum applied voltage used for measurement and a voltage application rate (heating rate) of 0.5V / second before measurement. The contact pressure is set to 0.2V.

[0092] The setting value for the downward displacement of the cantilever used to stop the measurement is 30 nm.

[0093] The softening point is the location where the vertical height (Z displacement) of the cantilever is the maximum, and the applied voltage at that point is read.

[0094] To convert the applied voltage of the cantilevered heater into softening temperature, a calibration curve was constructed comparing the applied voltage with the melting point (melting peak temperature). As calibration samples, samples whose melting point (melting peak temperature) had already been determined using a differential scanning calorimeter (DSC) were used. For each calibration sample, softening temperature measurements were performed at different measurement locations. A standard curve was constructed using a cubic function with the least squares method to approximate the average applied voltage at the softening location with the melting point (melting peak temperature), serving as the calibration curve. The calibration samples were polycaprolactone granules (melting point: 60°C), low-density polyethylene granules (melting point: 112°C), polypropylene granules (melting point: 166°C), and biaxially stretched polyethylene terephthalate film (melting point: 255°C), using cross-sectional specimens prepared below their respective glass transition temperatures. Ultramicrotome and CryoSystem were used to prepare the cross-sectional specimens. Polycaprolactone was cut at -80°C, low-density polyethylene at -140°C, polypropylene at -40°C, and polyethylene terephthalate at room temperature (25°C).

[0095] Using the calibration curve of applied voltage and melting point (melting peak temperature), the applied voltage at the softening point is converted into temperature as the softening temperature.

[0096] [Vapor Deposition Layer] The vapor-deposited layer is a layer disposed on the aforementioned substrate layer, for example, from the viewpoint of improving gas barrier properties against water vapor or oxygen, and preferably has transparency. The vapor-deposited layer contains an inorganic oxide, such as aluminum oxide, silicon oxide, tin oxide, magnesium oxide, or mixtures thereof. Considering heat sterilization resistance, from the viewpoint of suppressing oxygen permeability to a lower level after heat sterilization treatment and having a more sufficient adhesion strength between the membranes after heat sterilization treatment, it is particularly more preferable to use at least one selected from aluminum oxide and silicon oxide.

[0097] The thickness of the vapor-deposited layer can be 5 to 300 nm. If the thickness of the vapor-deposited layer is 5 nm or more, it is easy to obtain a film with uniform and sufficient thickness, which can fully perform its function as a gas barrier film. In addition, if the thickness of the vapor-deposited layer is 300 nm or less, the vapor-deposited layer can be given flexibility, and even if external factors such as bending or stretching are applied after film formation, cracking is unlikely to occur in the vapor-deposited layer. From this point of view, the thickness of the vapor-deposited layer is preferably 6 nm or more, more preferably 8 nm or more, and preferably 150 nm or less, more preferably 100 nm or less.

[0098] Vacuum-deposited layers can be formed using conventional vacuum evaporation methods. Other thin-film formation methods include sputtering, ion plating, and plasma vapor deposition (CVD). However, considering productivity, vacuum evaporation is currently the most superior method. For heating in vacuum evaporation, electron beam heating, resistance heating, or induction heating are preferred, but electron beam heating is more preferable considering the selectivity of the evaporation material. Furthermore, to improve the adhesion between the evaporated layer and the substrate layer, as well as the density of the evaporated layer, plasma-assisted or ion beam-assisted evaporation methods can be used. Additionally, to improve the transparency of the evaporated film, reactive evaporation using gases such as oxygen can be employed during the evaporation process.

[0099] To improve the adhesion between the substrate layer and the vapor-deposited layer, surface treatments such as plasma treatment or corona treatment can be applied to the vapor-deposited side surface of the substrate layer. Additionally, an anchor coating (not shown) can be applied between the substrate layer and the vapor-deposited layer. Applying an anchor coating can further improve the adhesion or barrier properties after heat sterilization. Examples of coating agents for applying the anchor coating include acrylic resins, epoxy resins, urethane acrylate resins, polyester polyurethane resins, and polyether polyurethane resins. From the viewpoint of heat resistance and interlayer adhesion strength, urethane acrylate resins and polyester polyurethane resins are preferred among these coating agents.

[0100] [Gas Barrier Layer] The gas barrier layer is provided to protect the vapor-deposited layer and supplement its barrier properties. The gas barrier layer can be formed from a coating liquid containing a silicon compound or its hydrolysate, and a water-soluble polymer having hydroxyl groups. Alternatively, the gas barrier layer can also be formed from a coating liquid containing a water-soluble polymer having hydroxyl groups, and at least one selected from metal alkoxides, silane coupling agents, and their hydrolysates.

[0101] Examples of water-soluble polymers containing hydroxyl groups include polyvinyl alcohol, polyvinylpyrrolidone, starch, methylcellulose, carboxymethylcellulose, and sodium alginate. Polyvinyl alcohol (PVA) is particularly preferred when used in coating agents because its gas barrier properties become even more excellent.

[0102] As a silicon compound, it is preferably selected from Si(OR) 1 )4 and R 2 Si(OR) 3 3 (OR) 1 and OR 3 Each is an independent hydrolyzable group, R 2 At least one of the organic functional groups. As Si (OR) 14. Tetraethoxysilane [Si(OC2H5)4] is preferably used. Tetraethoxysilane is preferred because it is relatively stable in aqueous solvents after hydrolysis. Additionally, as R... 2 Si(OR) 3 R in 3 2 Preferably selected from vinyl, epoxy, methacryloyloxy, urea, and isocyanate groups.

[0103] Examples of metal alkoxides include compounds represented by the following general formula.

[0104] M(OR) 11 ) m (R) 12 ) n-m (1) In the above formula (1), R 11 and R 12 Each is an independent monovalent organic group with 1 to 8 carbon atoms, preferably an alkyl group such as methyl or ethyl. M represents an n-valent metal atom such as Si, Ti, Al, or Zr. m is an integer from 1 to n. Furthermore, R... 11 and R 12 When multiple exist, R 11 Each other or R 12 They can be the same or different.

[0105] Examples of metal alkoxides include tetraethoxysilane [Si(OC2H5)4] and triisopropoxyaluminum [Al(O-2'-C3H7)3]. Tetraethoxysilane and triisopropoxyaluminum are preferred because they are relatively stable in aqueous solvents after hydrolysis.

[0106] Compounds represented by the following general formula can be cited as silane coupling agents.

[0107] Si(OR) 21 ) p (R) 22 ) 3-p R 23 (2) In the above formula (2), R 21 R represents alkyl groups such as methyl and ethyl. 22 R represents a monovalent organic group such as alkyl, aralkyl, aryl, alkenyl, alkyl substituted with acryloyloxy, or alkyl substituted with methacryloyloxy. 23 Let R represent a monovalent organic functional group, and p represent an integer from 1 to 3. Furthermore, when R... 21 Or R 22 When multiple exist, R 21 Each other or R 22 They can be the same or different. As R 23Examples of monovalent organic functional groups shown include glycidoxy, epoxy, mercapto, hydroxyl, amino, alkyl groups substituted with halogen atoms, or monovalent organic functional groups containing isocyanate groups. Compounds containing these silane coupling agents can also be used to form polymers such as dimers and trimers.

[0108] Specific examples of silane coupling agents include vinyltrimethoxysilane, γ-chloropropylmethyldimethoxysilane, γ-chloropropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropylmethyltriethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, and γ-methacryloyloxypropylmethyldimethoxysilane.

[0109] The gas barrier layer can be formed as follows: A water-soluble polymer is dissolved in water or a water / alcohol mixture, and then silicon compounds, metal alkoxides, silane coupling agents, or products that have undergone prior hydrolysis are directly mixed into the solution. This mixed solution is then coated onto the aforementioned vapor-deposited layer and heated to dry, thereby forming the barrier layer. In this solution, isocyanate compounds, or known additives such as dispersants, stabilizers, viscosity modifiers, and colorants can be added as needed, without compromising the gas barrier properties.

[0110] When using PVA as a water-soluble polymer, the proportion of PVA in the mixed solution, based on the total solid content of the mixed solution, is preferably 20% by mass or more and 50% by mass or less, more preferably 25% by mass or more and 40% by mass or less. When the proportion of PVA is 20% by mass or more, it is easier to maintain the flexibility of the membrane and to form a gas barrier layer. If the proportion of PVA is 50% by mass or less, the barrier membrane can be endowed with more sufficient gas barrier properties.

[0111] The thickness of the gas barrier layer can be greater than 0.05μm or greater than 0.1μm, and can be less than 10μm or less than 1μm.

[0112] <Second aspect barrier membrane> The second aspect of the barrier film sequentially comprises a substrate layer containing polypropylene, an evaporated layer containing inorganic oxides, and a gas barrier layer. The substrate layer is formed by two layers, a surface layer and a core layer, starting from the evaporated layer side. When the softening temperature of each layer of the substrate layer is determined by local thermal analysis (LTA), the surface layer has at least one softening temperature above 115°C and below 170°C, and the core layer has at least one softening temperature above 190°C.

[0113] Figure 2 This is a schematic cross-sectional view showing the barrier film of the second aspect of this embodiment. (See attached image.) Figure 2 As shown, the barrier film 10b of this embodiment sequentially comprises a substrate layer 1b, a vapor-deposited layer 2, and a gas barrier layer 3.

[0114] [Substrate Layer] The substrate layer 1b is a film (base film) that serves as a support and contains polypropylene. The substrate layer 1b is a multilayer film formed by two layers, starting from the vapor-deposited layer side: a surface layer 11b and a core layer 12. The substrate layer 1b can be a film formed of polypropylene, or it can be a film formed by stretching a polypropylene sheet into a uniaxial or biaxially oriented film using conventional methods. Stretching can also be performed on multilayer films. Known additives can also be added to the substrate layer 1b, depending on the purpose, such as organic additives like antioxidants, stabilizers, calcium stearate, fatty acid amides, erucamides, lubricants, and antistatic agents, and inorganic additives like silica, zeolite, sylate, hydrotalcite, and silicon particles.

[0115] The thickness (total thickness) of the substrate layer 1b is not particularly limited. For example, it can be 3μm or more and 200μm or less, 6μm or more and 50μm or less, or 10μm or more and 30μm or less.

[0116] The surface layer 11b is a layer that has at least one softening temperature between 115°C and 170°C when the softening temperature is measured from the membrane cross-section using local thermal analysis (LTA) as described later. From the viewpoint of improving heat resistance, the aforementioned at least one softening temperature can be 120°C or higher, 125°C or higher, or 130°C or higher; from the viewpoint of imparting flexibility, it can be 165°C or lower, or 160°C or lower. The softening temperature is measured at the center of the surface layer 11b in the thickness direction. With at least one softening temperature of 115°C or higher, the heat resistance of the surface layer 11b will not become too low, and the risk of softening of the surface layer 11b during heat sterilization treatment, leading to reduced adhesion or deterioration of barrier properties, is low. Furthermore, with at least one softening temperature of 170°C or lower, the reduction of the flexibility of the surface layer 11b can be suppressed, and the adhesion strength between the surface layer 11b and the core layer 12 can be improved. Moreover, the surface layer 11b can be a layer with one softening temperature, or it can be a layer with multiple softening temperatures. When the surface layer 11b has multiple softening temperatures, at least one softening temperature needs to satisfy the above conditions.

[0117] From the viewpoint of improving the adhesion with the core layer 12, the polypropylene used in the surface layer 11b can include copolymers of propylene and other monomers. Other monomers may include, for example, α-olefins such as ethylene, 1-butene, and 1-hexene. The surface layer 11b can contain copolymers of propylene and α-olefins. The copolymer can be a random copolymer. From the viewpoint of suppressing oxygen permeability to a lower level after heat sterilization and of achieving sufficient adhesion strength between membranes after heat sterilization, the polypropylene used in the surface layer 11b can contain random copolymers of propylene and two or more α-olefins, and may also contain ethylene-1-butene-propylene random copolymers.

[0118] From the perspective of suppressing oxygen permeability to a lower level after heat sterilization and of achieving a more sufficient adhesion strength between membranes after heat sterilization, the ethylene content in the polypropylene used in the surface layer 11b can be 1% or more by mass, 1.5% or more by mass, or 2% or more by mass, and can be 7% or less by mass, 6% or less by mass, 5% or less by mass, 4% or less by mass, or 3.5% or less by mass, based on the total amount of polypropylene.

[0119] From the viewpoint that oxygen permeability is also suppressed to a lower level after heat sterilization, the content of 1-butene in the polypropylene used in the surface layer 11b can be more than 1% by mass, more than 1.5% by mass, or more than 2% by mass, and can be less than 5% by mass, less than 4% by mass, or less than 3.5% by mass, based on the total amount of polypropylene.

[0120] The thickness of the surface layer 11b can be 0.2 μm or more. If the thickness of the surface layer 11b is 0.2 μm or more, the surface layer 11b and the core layer 12 can be uniformly laminated. Furthermore, after heat sterilization, oxygen permeability is suppressed to a lower level, and the interlayer adhesion strength is also more sufficient after heat sterilization. From this viewpoint, the thickness of the surface layer 11b is preferably 0.3 μm or more. On the other hand, there is no particular limitation on the upper limit of the thickness of the surface layer 11b; from the viewpoint of more sufficiently ensuring the overall heat resistance of the substrate layer 1b, it is preferably 2.0 μm or less, more preferably 1.8 μm or less. The thickness of the surface layer 11b can be 0.2 μm or more and 2.0 μm or less, or 0.3 μm or more and 1.8 μm or less.

[0121] The core layer 12 is a layer that has at least one softening temperature above 190°C when the softening temperature is measured from the film cross-section using local thermal analysis (LTA) as described later. The aforementioned at least one softening temperature can be above 195°C, above 200°C, above 205°C, or above 210°C, and can be below 220°C, below 215°C, or below 210°C. The softening temperature is measured at the center of the core layer 12 in the thickness direction. By having at least one softening temperature above 190°C, the heat resistance of the substrate layer 1b can be improved, allowing it to withstand the heat during heat sterilization treatment, thereby preventing the substrate layer 1b from shrinking during heat sterilization treatment and becoming unusable as a packaging material. Furthermore, the core layer 12 can be a layer with one softening temperature or a layer with multiple softening temperatures. When the core layer 12 has multiple softening temperatures, at least one softening temperature needs to satisfy the above conditions.

[0122] From the viewpoint of improving the heat resistance of the substrate layer 1b, the polypropylene used in the core layer 12 can be crystalline polypropylene. From the viewpoint of further improving the heat resistance for heat sterilization treatment, it can also be homopolymer polypropylene. However, as long as it does not significantly impair the effects of this disclosure, random copolymers of propylene and α-olefins, or mixtures of said copolymers and homopolymer polypropylene, etc., can also be used.

[0123] The softening temperature of the core layer 12, which is above 190°C, is at least 20°C higher, at least 40°C higher, and at least 50°C higher than the softening temperature of the surface layer 11b, which is between 115°C and 170°C. This further reduces the shrinkage of the substrate layer 1b during heat sterilization and more effectively maintains the bonding strength between the layers after heat sterilization.

[0124] The thickness of the core layer 12 can be greater than 2μm, greater than 10μm, or greater than 15μm, and can be less than 150μm, less than 50μm, or less than 20μm.

[0125] The ratio of the thickness of the surface layer 11b to the thickness of the core layer 12 (thickness of surface layer 11b / thickness of core layer 12) can be 1 / 100 to 1 / 5, 1 / 80 to 1 / 8, or 1 / 70 to 1 / 10. If the thickness ratio is within the above range, the overall heat resistance of the substrate layer 1b can be more fully ensured, and the oxygen permeability can be suppressed to a lower level even after heat sterilization treatment. Furthermore, the inter-membrane bonding strength can be more sufficient after heat sterilization treatment.

[0126] The substrate layer 1b is formed only by the surface layer 11b and the core layer 12. The surface layer 11b and the core layer 12 are in contact without any other layers sandwiched between them. Both surfaces of the substrate layer 1b are formed by the surface layer 11b and the core layer 12.

[0127] There are no particular limitations on the method for adjusting the softening temperature of the surface layer 11b and the core layer 12. The softening temperature of each layer can be adjusted, for example, by adjusting the type of resin that makes up each layer, the mixing ratio of multiple resins when using them, the monomer ratio (e.g., ethylene content) when using copolymers, and the manufacturing method of each layer (e.g., stretching conditions).

[0128] The polypropylene (comprising copolymers of propylene and other monomers) used in the substrate layer 1b can be recycled resin or resin obtained by polymerizing biomass-derived raw materials such as plants. These resins can be used alone or in combination with resins polymerized from conventional fossil fuels.

[0129] The softening temperature of the substrate layer in this embodiment is measured using the same method as the softening temperature measurement described in the first aspect above.

[0130] [Vapor Deposition Layer] The vapor-deposited layer in this embodiment can have the same configuration as the vapor-deposited layer described in the first aspect above.

[0131] [Gas Barrier Layer] The gas barrier layer in this embodiment can have the same configuration as the gas barrier layer described in the first aspect above.

[0132] <Layered Body> Figure 3 and Figure 4 This is a schematic cross-sectional view showing the laminated body of the first aspect of this embodiment. (See attached image.) Figure 3 and Figure 4 As shown, the laminates 20a and 30a of this embodiment have a structure in which a second substrate layer (outer film) 22 and a sealant layer 23 are laminated on both sides of the barrier film 10a through an adhesive layer 24. Figure 3 In the laminate 20a shown, a second substrate layer 22 is laminated on the gas barrier layer 3 of the barrier film 10a, and a sealant layer 23 is laminated on the second surface layer 13 of the barrier film 10a. Figure 4 In the laminate 30a shown, a second substrate layer 22 is laminated on the second surface layer 13 of the barrier film 10a, and a sealant layer 23 is laminated on the gas barrier layer 3 of the barrier film 10a.

[0133] Figure 5 and Figure 6This is a schematic cross-sectional view showing the laminated body according to the second aspect of this embodiment. (See attached image.) Figure 5 and Figure 6 As shown, the laminates 20b and 30b of this embodiment have a structure in which a second substrate layer (outer film) 22 and a sealant layer 23 are laminated on both sides of the barrier film 10b through an adhesive layer 24. Figure 5 In the laminate 20b shown, a second substrate layer 22 is laminated on the gas barrier layer 3 of the barrier film 10b, and a sealant layer 23 is laminated on the core layer 12 of the barrier film 10b. Figure 6 In the laminate 30b shown, a second substrate layer 22 is laminated on the core layer 12 of the barrier film 10b, and a sealant layer 23 is laminated on the gas barrier layer 3 of the barrier film 10b.

[0134] To make the laminates 20a, 30a, 20b, and 30b a single-material packaging material, polyolefin is used as the material for the second substrate layer 22 and the sealant layer 23. Polypropylene is preferably used, similar to the substrate layers 1a and 1b of the barrier films 10a and 10b. For example, a film of homopolymer polypropylene stretched for heat resistance can be used as the polypropylene used in the second substrate layer 22. For example, a stretched or unstretched polypropylene film can be used as the sealant layer 23.

[0135] The thickness of the second substrate layer 22 is not particularly limited; for example, it can be 15 μm or more, or 200 μm or less.

[0136] The thickness of the sealant layer 23 is not particularly limited; for example, it can be 15 μm or more, or 200 μm or less.

[0137] Adhesive layer 24 is a layer that bonds the films together. Examples of adhesives constituting adhesive layer 24 include polyurethane resins obtained by reacting difunctional or higher isocyanate compounds with polyester polyols, polyether polyols, acrylic polyols, carbonate polyols, etc., as the main agent. One type of polyol may be used alone, or two or more may be used in combination. To promote adhesion, adhesive layer 24 may also incorporate carbodiimide compounds, oxazoline compounds, epoxy compounds, phosphorus compounds, silane coupling agents, etc., into the aforementioned polyurethane resin. The amount of adhesive applied to adhesive layer 24, from the viewpoint of obtaining desired adhesive strength, conformability, and processability, may be, for example, 0.5 to 10 g / m³. 2 From an environmental perspective, adhesive layer 24 can be made from polymers that are biomass-derived or biodegradable. Alternatively, adhesive layer 24 can be made from a barrier adhesive.

[0138] <Packaging Bags> The packaging bag can be manufactured using the aforementioned laminated structure. The packaging bag can be formed by folding a single sheet of packaging material with the sealant layers facing each other and then heat-sealing three sides; or it can be formed by overlapping two sheets of packaging material with the sealant layers facing each other and then heat-sealing all four sides. The packaging bag can contain food, medicine, or other similar items. Furthermore, the packaging bag can be a stand-up pouch or similar shape with a curved portion (bend). Even with a curved portion, the packaging bag of this embodiment maintains high gas barrier properties.

[0139] Example The present disclosure will now be described in more detail with reference to the embodiments, but the present disclosure is not limited to these examples.

[0140] <Example 1-1> The first surface layer uses ethylene-1-butene-propylene random copolymer resin, the core layer uses homopolymer polypropylene resin, and the second surface layer uses ethylene-propylene random copolymer resin. These resins are co-extruded and then biaxially stretched to produce a substrate film (substrate layer) with a total thickness of 20 μm. The thickness of the first and second surface layers is 0.7 μm, and the core layer is 18.6 μm thick. The softening temperatures of each layer are shown in Table 1.

[0141] Next, an acrylic primer solution is applied to the first surface layer of the substrate layer using gravure coating and then dried to form an anchor coating with a thickness of 0.1 μm. Then, a 30 nm thick silicon oxide film is deposited on the anchor coating using reactive evaporation with high-frequency excited ion plating in an ambient gas under reduced pressure, forming an inorganic oxide vapor-deposited layer.

[0142] Next, tetraethoxysilane (hereinafter referred to as "TEOS"), methanol, and 0.1N hydrochloric acid were mixed in a mass ratio of 45 / 15 / 40 to obtain a TEOS hydrolysis solution. This solution, a 5% by mass aqueous solution of polyvinyl alcohol (hereinafter referred to as "PVA"), and 1,3,5-tris(3-methoxysilylpropyl)isocyanurate were diluted with a water / IPA (isopropanol) = 1 / 1 solution to a solid content of 5% by mass (R). 2 The coating solution is prepared by mixing these three solutions (Si(OH)3 conversion) together. The coating solution is prepared according to the SiO2 solid content (conversion value) of TEOS and the R of isocyanurate silane. 2The Si(OH)3 solid component (converted value) and PVA solid component were prepared in a mass ratio of 40 / 5 / 55. The coating solution was applied onto the vapor-deposited layer using a gravure coating method and then dried at 80°C for 60 seconds to form a gas barrier layer with a thickness of 0.3 μm. This yields the barrier film of Example 1-1, which has a laminated structure of gas barrier layer / vapor-deposited layer / anchor coating / first surface layer / core layer / second surface layer.

[0143] <Example 1-2> According to the softening temperature of each layer as shown in Table 1, the material of the first surface layer is ethylene-1-butene-propylene random copolymer resin, the material of the core layer is homopolymer polypropylene resin, and the material of the second surface layer is ethylene-1-butene-propylene random copolymer resin. Otherwise, the barrier film is obtained in the same way as in Examples 1-1.

[0144] <Examples 1-3> According to the softening temperature of each layer as shown in Table 1, the material of the first surface layer is ethylene-propylene random copolymer resin, the material of the core layer is homopolymer polypropylene resin, and the material of the second surface layer is ethylene-propylene random copolymer resin. Otherwise, the barrier film is obtained in the same way as in Examples 1-1.

[0145] <Examples 1-4> According to the softening temperature of each layer as shown in Table 1, the material of the first surface layer is ethylene-1-butene-propylene random copolymer resin, the material of the core layer is homopolymer polypropylene resin, and the material of the second surface layer is ethylene-propylene random copolymer resin. Otherwise, the barrier film is obtained in the same way as in Examples 1-1.

[0146] <Comparative Example 1-1> Following the method of changing the softening temperature of each layer as shown in Table 1, homopolymer polypropylene resin was used as the material for the first surface layer, the core layer, and the second surface layer. Otherwise, the barrier film was obtained in the same manner as in Examples 1-1.

[0147] <Comparative Examples 1-2> According to the softening temperature of each layer as shown in Table 1, the material for the first surface layer is ethylene-1-butene-propylene random copolymer resin, and the materials for the core layer and the second surface layer are both homopolymer polypropylene resin. Otherwise, the barrier film is obtained in the same manner as in Examples 1-1.

[0148] <Comparative Examples 1-3> According to the softening temperature of each layer as shown in Table 1, ethylene-propylene random copolymer resin was used as the material for the first and second outer layers, and homopolymer polypropylene resin was used as the material for the core layer. Otherwise, the barrier film was obtained in the same manner as in Examples 1-1.

[0149] <Comparative Examples 1-4> According to the softening temperature of each layer as shown in Table 1, the material of the first surface layer is ethylene-1-butene-propylene random copolymer resin, the material of the core layer is homopolymer polypropylene resin, and the material of the second surface layer is ethylene-propylene random copolymer resin. Otherwise, the barrier film is obtained in the same way as in Examples 1-1.

[0150] <Comparative Examples 1-5> According to the softening temperature of each layer as shown in Table 1, the material of the first surface layer is ethylene-propylene random copolymer resin, the material of the core layer is homopolymer polypropylene resin, and the material of the second surface layer is ethylene-propylene random copolymer resin. Otherwise, the barrier film is obtained in the same way as in Examples 1-1.

[0151] [Creating Layered Objects] A 20 μm thick stretched polypropylene film and the gas barrier layer side of the barrier films prepared in Examples 1-1 to 1-4 and Comparative Examples 1-1 to 1-5 were bonded together using a two-component curable urethane adhesive via dry lamination. Then, the second surface layer side of the barrier film was bonded to a 60 μm thick unstretched polypropylene film using a two-component curable urethane adhesive via dry lamination to create a three-layer laminate.

[0152] [evaluate] (Determination of softening temperature) The softening temperature of each layer constituting the substrate layer was determined using the method shown below.

[0153] The laminates prepared using the barrier films produced in Examples 1-1 to 1-4 and Comparative Examples 1-1 to 1-5 were used as test samples, and corona treatment was performed on the front and back sides of the samples at 0.20 kW. The corona treatment was performed using a corona treatment machine (trade name: CT-0212) manufactured by Kasuga Electric Co., Ltd.

[0154] After corona treatment of the sample's surface and back, the sample was cut into a wedge shape with a base of 1.0 mm and a height of 5.0 mm using a razor (the triangular face with the aforementioned base and height represents the sample's surface and back, and the bottom and side faces represent the sample's cross-sectional shape). The cut sample was embedded in a UV-curable resin and cured using a halogen lamp (Kenko Tokina, trade name: KTX-100R). The UV-curable resin used was D-800 (trade name) manufactured by Toa Synthetic Co., Ltd. The UV-cured sample was fixed in place with the embedded resin using an AFM sample holder. After cross-sectional cutting of the sample using a glass cutter at room temperature (25°C), the final cross-sectional cutting was performed at low temperature (-140°C) using a diamond cutter at a cutting speed of 1.0 mm / s and a cutting film thickness of 100 nm. The cutting was stopped when the sample reached a mirror finish. The Ultramicrotome (manufactured by Leica, trade name: EM UC7) and CryoSystem (manufactured by Leica, trade name: EMFC7) were used as the cross-section cutting apparatus. Furthermore, the cutting direction of the tool was parallel to the layer interface. Cutting was performed from the apex of the wedge shape. The cross-sectioned sample, fixed with inserts using an AFM sample holder, was used for softening temperature determination.

[0155] Atomic force microscopy (AFM) was performed using an Oxford Instruments MFP-3D-SA (trade name), with the local thermal analysis option using a Ztherm system. An Anasys Instruments AN2-200 (trade name) cantilever with a spring constant of 0.5~3.5 N / m was used for softening temperature and shape measurements. Softening temperature measurements were performed at the center of the thickness direction of each layer constituting the substrate (first surface layer, core layer, and second surface layer).

[0156] With the cantilever pressure (change in cantilever deflection) set at 0.2V, the voltage application rate (heating rate) at 0.5V / second, and the maximum applied voltage at 6.0V, the sample surface expanded and the cantilever position rose when heated after Detrend correction. Further heating softened the sample surface, and the measurement ended when the cantilever position decreased by 30nm. If the maximum applied voltage was reached before the Z-displacement point decreased by 30nm, the maximum applied voltage during Detrend correction and measurement was increased by 0.5V, and the measurement was performed again.

[0157] The voltage applied at the point where the vertical height (Z displacement) of the cantilever is maximum is taken as the voltage applied at the softening point, and the voltage value is read.

[0158] To calculate the softening temperature of the samples, a calibration curve was constructed. Four types of samples were used for calibration: polycaprolactone (melting point: 60℃), low-density polyethylene (LDPE, melting point: 112℃), polypropylene (PP, melting point: 166℃), and polyethylene terephthalate (PET, melting point: 255℃). The maximum applied voltage during Detrend correction was 3.5V for polycaprolactone, 5.5V for LDPE, 6.7V for polypropylene, and 7.9V for polyethylene terephthalate. The cantilever pressure (change in cantilever deflection) was set to 0.2V, and the voltage application rate (heating rate) was set to 0.5V / second. Measurements were performed 20 times at different locations on the calibration samples. A standard curve was constructed, approximating the average applied voltage at the softening point and the melting point using a cubic function with the least squares method. This was used to construct the calibration curve.

[0159] Using a calibration curve of applied voltage and melting point (melting peak temperature), the applied voltage at the softening points of each layer constituting the substrate layer (first surface layer, core layer, and second surface layer) was converted into temperature and used as the softening temperature. The results are shown in Table 1.

[0160] (High-temperature steaming treatment) Using the laminates prepared in Examples 1-1 to 1-4 and Comparative Examples 1-1 to 1-5, a packaging bag with four sealed sides was made, and water was filled as the contents. It was then subjected to high-temperature sterilization treatment at 130°C for 30 minutes.

[0161] (Oxygen permeability measurement) Oxygen permeability was measured on the laminated body after high-temperature cooking. The measurement was performed using an oxygen permeability measuring apparatus (Modern Control, OXTRAN 2 / 20) at 30°C and 70% relative humidity. The measurement method followed JIS K-7126, Method B (isobaric method) and ASTM D3985-81. Measured values ​​are expressed in cm⁻¹. 3 (STP) / m 2 [day·atm] represents the time. The results are shown in Table 1.

[0162] (Lamination strength measurement) For laminates subjected to high-temperature cooking, the lamination strength between stretched polypropylene film and barrier film (referred to as "OPP / Barrier" in the table) and between barrier film and unstretched polypropylene film (referred to as "Barrier / CPP" in the table) was determined. The determination was conducted according to JIS K6854, with a test width of 15 mm, a peel speed of 300 mm / min, and a T-shaped peel angle. The measured values ​​are expressed in [N / 15 mm]. The results are shown in Table 1. 1: Membrane rupture without delamination at the interface 2: Delamination occurs at the interface between the first surface layer and the core layer. 3: Delamination occurs at the interface between the core layer and the second surface layer. 4: Peeling occurs at the surface of the second layer. 5: The peeling location shifts towards the interface between the core layer and the second surface layer. The results shown in Table 1 confirm that the packaging bags using the barrier films of Examples 1-1 to 1-4 can maintain very low oxygen permeability even after heat sterilization, while exhibiting excellent interlayer lamination strength. Furthermore, in Comparative Examples 1-1 and 1-3, the increased oxygen permeability after heat sterilization is attributed to cracks generated in the vapor-deposited layer during the heat sterilization process. Additionally, in Comparative Examples 1-4, the decreased interlayer lamination strength between the OPP and the barrier film is due to the peeling point shifting towards the interface between the core layer and the second surface layer.

[0163] <Example 2-1> Ethylene-1-butene-propylene random copolymer resin (ethylene content: 2.5 mol%, 1-butene content: 3.5 mol%) was used as the surface layer material, and homopolymer polypropylene resin was used as the core layer material. These resins were co-extruded and biaxially stretched to produce a substrate film (substrate layer) with a total thickness of 20 μm, consisting of a 0.7 μm thick surface layer and a 19.3 μm thick core layer. The thicknesses of the surface and core layers were measured using the thickness method described later. The softening temperatures of each layer are shown in Table 2.

[0164] Next, an acrylic primer solution is applied to the surface of the substrate layer using gravure coating and then dried to form an anchor coating with a thickness of 0.1 μm. Then, a 30 nm thick silicon oxide film is deposited on the anchor coating using reactive evaporation with high-frequency excited ion plating in an oxygen environment under reduced pressure, forming an inorganic oxide vapor-deposited layer.

[0165] Next, tetraethoxysilane (hereinafter referred to as "TEOS"), methanol, and 0.1N hydrochloric acid were mixed in a mass ratio of 45 / 15 / 40 to obtain a TEOS hydrolysis solution. This solution, a 5% by mass aqueous solution of polyvinyl alcohol (hereinafter referred to as "PVA"), and 1,3,5-tris(3-methoxysilylpropyl)isocyanurate were diluted with a water / IPA (isopropanol) = 1 / 1 solution to a solid content of 5% by mass (R). 2 The coating solution is prepared by mixing these three solutions (Si(OH)3 conversion) together. The coating solution is prepared according to the SiO2 solid content (conversion value) of TEOS and the R of isocyanurate silane.2 The Si(OH)3 solid component (converted value) and PVA solid component were prepared in a mass ratio of 43 / 10 / 47. The coating solution was applied to the vapor-deposited layer using a gravure coating method and then dried at 80°C for 60 seconds to form a gas barrier layer with a thickness of 0.3 μm. This yielded the barrier film of Example 2-1, which has a multilayer structure of gas barrier layer / vapor-deposited layer / anchor coating / surface layer / core layer.

[0166] <Example 2-2> Following the method of changing the softening temperature of each layer as shown in Table 2, an ethylene-1-butene-propylene random copolymer resin (ethylene content: 2.0 mol%, 1-butene content: 2.0 mol%) was used as the material for the surface layer to prepare a substrate film having a surface layer with a thickness of 0.8 μm and a core layer with a thickness of 19.2 μm. Otherwise, the barrier film was obtained in the same manner as in Example 2-1.

[0167] <Example 2-3> Following the method of changing the softening temperature of each layer as shown in Table 2, an ethylene-propylene random copolymer resin (ethylene content: 5.0 mol%) was used as the material for the surface layer to prepare a substrate film having a surface layer with a thickness of 0.8 μm and a core layer with a thickness of 19.2 μm. Otherwise, the barrier film was obtained in the same manner as in Example 2-1.

[0168] <Example 2-4> Following the method of changing the softening temperature of each layer as shown in Table 2, an ethylene-propylene random copolymer resin (ethylene content: 3.2 mol%) was used as the material for the surface layer to prepare a substrate film having a surface layer with a thickness of 1.5 μm and a core layer with a thickness of 18.5 μm. Otherwise, the barrier film was obtained in the same manner as in Example 2-1.

[0169] <Examples 2-5> Following the method of changing the softening temperature of each layer as shown in Table 2, an ethylene-propylene random copolymer resin (ethylene content: 3.2 mol%) was used as the material for the surface layer to prepare a substrate film with a total thickness of 18 μm, having a surface layer with a thickness of 0.3 μm and a core layer with a thickness of 17.7 μm. Otherwise, the barrier film was obtained in the same manner as in Example 2-1.

[0170] <Comparative Example 2-1> A substrate film (substrate layer) with a total thickness of 20 μm was made solely from the core layer material, otherwise the barrier film was obtained in the same manner as in Example 2-1.

[0171] <Comparative Example 2-2> Following the method of changing the softening temperature of each layer as shown in Table 2, the surface layer material was ethylene-1-butene-propylene random copolymer resin (ethylene content: 3.2 mol%, 1-butene content: 5.0 mol%), and the barrier film was otherwise obtained in the same manner as in Example 2-1.

[0172] <Comparative Examples 2-3> Following the method of changing the softening temperature of each layer as shown in Table 2, an ethylene-propylene random copolymer resin (ethylene content: 0.7 mol%) was used as the material for the surface layer to prepare a substrate film having a surface layer with a thickness of 0.8 μm and a core layer with a thickness of 19.2 μm. Otherwise, the barrier film was obtained in the same manner as in Example 2-1.

[0173] [Creating Layered Objects] In Examples 2-1 to 2-5 and Comparative Examples 2-1 to 2-3, a 60 μm thick unstretched polypropylene film was bonded to the gas barrier layer side of the barrier film using a dry lamination method with a two-component curable urethane adhesive to create a two-layer laminate.

[0174] [evaluate] (Determination of the thickness of the surface and core layers) The prepared barrier film was embedded in a photocurable resin to form a block. The block was then cross-sectionally machined using a diamond cutter on an Ultramicrotome (Leica Microsystems EM UC7). The machined cross-section was observed at 5000-20000x magnification using a scanning electron microscope (Hitachi SU8020), and the thickness was determined from the observed images.

[0175] (Determination of softening temperature) The softening temperatures of each layer (surface layer and core layer) constituting the substrate layers of Examples 2-1 to 2-5 and Comparative Examples 2-1 to 2-3 were determined using the same method as that used to determine the softening temperatures of each layer constituting the substrate layers of Examples 1-1 to 1-4 and Comparative Examples 1-1 to 1-5. The results are shown in Table 2.

[0176] (High-temperature steaming treatment) Using the laminated bodies prepared in Examples 2-1 to 2-5 and Comparative Examples 2-1 to 2-3, a packaging bag with four sealed sides was made, and water was filled as the contents. Then, it was subjected to high-temperature sterilization treatment at 130°C for 30 minutes.

[0177] (Oxygen permeability measurement) Oxygen permeability was measured on the laminated body after high-temperature cooking. The measurement was performed using an oxygen permeability measuring apparatus (Modern Control, OXTRAN 2 / 20) at 30°C and 70% relative humidity. The measurement method followed JIS K-7126, Method B (isobaric method) and ASTM D3985-81. Measured values ​​are expressed in cm⁻¹. 3 (STP) / m 2 [day·atm] indicates. If the oxygen permeability is 2.0 cm⁻¹ 3 (STP) / m 2 If the oxygen permeability is below ·day·atm, it is determined that the laminate has a low oxygen permeability even after high-temperature cooking. The results are shown in Table 2.

[0178] (Lamination strength measurement) The lamination strength between the barrier film and the unstretched polypropylene film was determined in the laminate after high-temperature cooking treatment. The determination was performed according to JIS K6854, with a test width of 15 mm, a peel speed of 300 mm / min, and a T-shaped peel angle. The measured values ​​are expressed in [N / 15 mm]. The results are shown in Table 2.

[0179] 1: The membrane breaks without peeling at the interface between the barrier membrane and the unstretched polypropylene membrane. 2: Delamination occurs between the surface layer and the core layer. 3: Peeling occurs at the surface of the substrate film (substrate layer). Industrial availability Packaging bags using the barrier film disclosed herein can be used as packaging materials with minimal degradation of barrier properties and reduction of seal even after heat sterilization treatments such as boiling and high-temperature cooking. Furthermore, as a single-material packaging material, it can provide a gas barrier packaging material suitable for recycling.

[0180] Symbol Explanation 1a, 1b Substrate layer, 2 Evaporated layer, 3 Gas barrier layer, 10a, 10b Barrier film, 11a First surface layer, 11b Surface layer, 12 Core layer, 13 Second surface layer, 20a, 20b, 30a, 30b Laminate, 22 Second substrate layer, 23 Sealant layer, 24 Adhesive layer.

Claims

1. A barrier film comprising, in sequence, a substrate layer comprising polypropylene, a vapor-deposited layer comprising inorganic oxides, and a gas barrier layer. The substrate layer has a multilayer structure comprising at least three layers in sequence: a first surface layer, a core layer, and a second surface layer. The vapor-deposited layer is formed on the surface of the first surface layer opposite to the core layer. When the softening temperature of each layer of the substrate layer is determined using local thermal analysis (LTA), the first surface layer has at least one softening temperature above 120°C, the core layer has at least one softening temperature above 190°C, the second surface layer has at least one softening temperature below 160°C, and the first surface layer has a softening temperature that is higher than any softening temperature present in the second surface layer.

2. The barrier membrane according to claim 1, wherein, When the softening temperature of the first surface layer is determined using LTA, at least one softening temperature exists between 120°C and 170°C.

3. The barrier membrane according to claim 1, wherein, When the softening temperature of the second surface layer is determined using LTA, at least one softening temperature exists between 120°C and 160°C.

4. The barrier membrane according to claim 1, wherein, The first and second surface layers comprise copolymers of propylene and α-olefins.

5. The barrier membrane according to claim 1, wherein, When the softening temperature of each layer of the substrate layer is determined using LTA, the core layer has a softening temperature that is higher than that of either the first or the second surface layer.

6. The barrier membrane according to claim 1, wherein, The thickness of both the first and second surface layers is less than 2.0 μm.

7. The barrier membrane according to claim 1, wherein, The vapor-deposited layer comprises at least one selected from alumina and silicon oxide.

8. The barrier membrane according to claim 1, wherein, The gas barrier layer comprises: a water-soluble polymer having hydroxyl groups; and at least one selected from metal alkoxides, silane coupling agents and their hydrolysates.

9. The barrier film according to claim 1, wherein an anchor coating is provided between the first surface layer and the vapor-deposited layer.

10. A barrier film comprising, in sequence, a substrate layer comprising polypropylene, a vapor-deposited layer comprising inorganic oxides, and a gas barrier layer. The substrate layer is formed by two layers, a surface layer and a core layer, starting from the side of the vapor-deposited layer. When the softening temperature of each layer of the substrate layer is determined using local thermal analysis (LTA), the surface layer has at least one softening temperature above 115°C and below 170°C, and the core layer has at least one softening temperature above 190°C and below 220°C.

11. The barrier film according to claim 10, wherein, The surface layer comprises a copolymer of propylene and α-olefin.

12. The barrier membrane according to claim 10, wherein, The surface layer comprises an ethylene-1-butene-propylene random copolymer.

13. The barrier film according to claim 10, wherein, The thickness of the surface layer is greater than 0.2 μm and less than 2.0 μm.

14. The barrier membrane according to claim 10, wherein, The ratio of the thickness of the surface layer to the thickness of the core layer is 1 / 100 to 1 / 5.

15. The barrier membrane according to claim 10, wherein, The vapor-deposited layer comprises at least one selected from alumina and silicon oxide.

16. The barrier film according to claim 10, wherein, The gas barrier layer is formed from a coating solution containing at least one silicon compound selected from Si(OR 1 )4 and R 2 Si(OR 3 )3, or a hydrolyzate thereof, and a water-soluble high polymer having a hydroxyl group, wherein OR 1 and OR 3 are each independently a hydrolyzable group, and R 2 is an organic functional group.

17. The barrier membrane according to claim 10, wherein, An anchor coating is provided between the surface layer and the vapor-deposited layer.

18. A laminate comprising a barrier film and a sealant layer according to any one of claims 1 to 17, wherein the sealant layer comprises a polyolefin.

19. The laminate according to claim 18, wherein, A second substrate layer comprising polyolefin is further provided on the surface of the barrier film opposite to the sealant layer.

20. A packaging bag made by forming the laminated body of claim 18.

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