Sheet, laminate, packaging bag, and package

Abstract

A sheet containing a polyolefin-based resin as a binder and a zeolite as a hydrogen sulfide adsorption substance, wherein the pore diameter of the zeolite is 3.5-5.5 Å.

Description

Sheets, laminates, packaging bags, and packaging

[0001] This disclosure relates to sheets, laminates, packaging bags, and packaging bodies.

[0002] All-solid-state batteries have seen significant development in recent years due to their ability to operate at higher temperatures compared to conventional liquid lithium-ion batteries. Sulfide-based electrolytes are the mainstream for all-solid-state batteries. However, because all-solid-state batteries using sulfide-based electrolytes contain sulfur, moisture that enters the battery reacts with the sulfur to produce hydrogen sulfide (H), which is harmful to the human body. ２ S) may occur. There is a concern that if the battery's casing is damaged, this hydrogen sulfide may leak out.

[0003] Incidentally, the outer casing of all-solid-state batteries uses a laminate comprising a base layer and a sealant layer. Such laminates may have a barrier layer (such as aluminum foil) to prevent moisture from entering the solid electrolyte. However, even with a barrier layer, it is not possible to completely prevent moisture from entering from the edges of the outer casing, i.e., the edges of the sealant layer. The moisture that enters can cause the generation of hydrogen sulfide.

[0004] As a packaging material for removing hydrogen sulfide generated in this manner, Patent Document 1 discloses a packaging material comprising a base layer, a gas barrier layer, and a sealant layer made of a sulfur-based gas-absorbing sealant film, wherein the sulfur-based gas-absorbing sealant film contains a specific sulfur-based gas absorbent and a heat-sealable resin.

[0005] Furthermore, Patent Document 2 discloses a laminate sheet for sulfide-based all-solid-state batteries having a barrier layer and an absorbent layer containing a desiccant, wherein the absorbent layer further contains a sulfide-based gas absorbent.

[0006] Patent No. 7423964, Patent No. 7356257

[0007] The inventors investigated removing hydrogen sulfide using a sheet containing a binder and a hydrogen sulfide adsorbent. They selected a polyolefin resin as the binder and zeolite as the hydrogen sulfide adsorbent. Zeolite is also a solid acid catalyst and is used as a polyolefin decomposition catalyst. The temperature required for polyolefin decomposition is approximately 400°C.

[0008] When such a sheet is used in an all-solid-state battery, the operating temperature of the all-solid-state battery can reach up to approximately 120°C. However, the inventors' research has revealed that if the battery continues to operate in such a temperature environment for a long period of time, decomposition of the polyolefin resin by the zeolite may occur.

[0009] This disclosure provides a sheet that has sufficient adsorption capacity for hydrogen sulfide while suppressing the decomposition of polyolefin resins even in high-temperature environments. This disclosure also provides laminates, packaging bags, and packaging bodies comprising such sheets.

[0010] One aspect of this disclosure provides the following sheets, laminates, packaging bags, and packaging materials: [1] A sheet comprising a polyolefin resin as a binder and a zeolite as a hydrogen sulfide adsorbent, wherein the pore size of the zeolite is 3.5 Å to 5.5 Å. [2] The sheet according to [1], wherein the skeletal structure of the zeolite is type A. [3] The sheet according to [1] or [2], wherein the silica / alumina ratio of the zeolite is 2.5 or less. [4] The sheet according to any one of [1] to [3], wherein the cation supported on the zeolite is at least one cation selected from the group consisting of zinc ions, silver ions, copper ions, calcium ions, potassium ions, sodium ions, manganese ions, cobalt ions, nickel ions, and ammonium ions. [5] The sheet according to any one of [1] to [4], wherein the polyolefin resin comprises a polypropylene resin. [6] A laminate comprising a base layer and the sheet according to any one of [1] to [5]. [7] The laminate according to [6], further comprising a barrier layer between the base material layer and the sheet. [8] The laminate according to [7], wherein the barrier layer comprises aluminum foil containing iron, and the iron content is 0.1 to 9.0% by mass based on the total amount of aluminum foil. [9] The laminate according to [7] or [8], further comprising a first corrosion-preventive treatment layer between the base material layer and the barrier layer, and further comprising a second corrosion-preventive treatment layer between the barrier layer and the sheet.

[10] The laminate according to [8] or [9], comprising the above-mentioned base layer, a first adhesive layer, the above-mentioned barrier layer, an adhesive resin layer, and the above-mentioned sheet in this order, wherein the pore size of the zeolite is 4.5 Å to 5.5 Å, the skeletal structure of the zeolite is type A, the silica / alumina ratio of the zeolite is 1.5 to 2.5, the cations supported on the zeolite include zinc ions and silver ions, the polyolefin resin includes a polypropylene resin, and the iron content is 0.5 to 2.0% by mass based on the total amount of the aluminum foil.

[11] The laminate according to any one of [6] to

[10] , for use in an all-solid-state battery.

[12] A packaging bag comprising the laminate described in any of [6] to

[11] .

[13] A packaging body comprising a packaging bag and contents contained within the packaging bag, wherein the packaging bag or contents comprises a sheet described in any of [1] to [5].

[14] The packaging body according to

[13] wherein the contents comprise a battery element having a sulfide-based solid electrolyte.

[15] The packaging body according to

[13] wherein the contents comprise a food that releases hydrogen sulfide.

[0011] This disclosure provides a sheet that has sufficient adsorption capacity for hydrogen sulfide while suppressing the decomposition of polyolefin resins even in high-temperature environments. Furthermore, this disclosure provides laminates, packaging bags, and packaging bodies comprising such sheets.

[0012] Figure 1 is a schematic cross-sectional view of a sheet according to one embodiment of the present disclosure. Figure 2 is a schematic cross-sectional view of an outer casing material for an all-solid-state battery according to one embodiment of the present disclosure. Figure 3 is a schematic cross-sectional view of an outer casing material for an all-solid-state battery according to one embodiment of the present disclosure. Figure 4 is a schematic cross-sectional view of an outer casing material for an all-solid-state battery according to one embodiment of the present disclosure. Figure 5 is a schematic cross-sectional view of an outer casing material for an all-solid-state battery according to one embodiment of the present disclosure. Figure 6 is a schematic cross-sectional view of an outer casing material for an all-solid-state battery according to one embodiment of the present disclosure. Figure 7 is a schematic front view of an example of a packaging bag. Figure 8 is a perspective view of an all-solid-state battery according to one embodiment of the present disclosure.

[0013] Preferred embodiments of this disclosure will be described in detail below, with appropriate reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and redundant descriptions are omitted. Furthermore, the dimensional ratios in the drawings are not limited to those shown. Unless otherwise specified, the example materials may be used individually or in combination of two or more types.

[0014] [Sheet] The sheet according to one embodiment of the present disclosure will be described below. Figure 1 is a schematic cross-sectional view of the sheet according to the present embodiment. As shown in Figure 1, the sheet 1 according to the present embodiment is a single layer. The sheet 1 contains a polyolefin resin as a binder and zeolite as a hydrogen sulfide adsorbent. The pore size of the zeolite is 3.5 Å to 5.5 Å. The sheet 1 is a hydrogen sulfide adsorbent sheet that adsorbs hydrogen sulfide.

[0015] Sheet 1 possesses sufficient adsorption capacity for hydrogen sulfide while suppressing the decomposition of polyolefin resin even in high-temperature environments. The inventors speculate on the reason for this effect as follows: Zeolite has the property of being difficult to desorb once it has adsorbed hydrogen sulfide. Furthermore, the pore size of the zeolite is 3.5 Å or larger, which promotes the adsorption of hydrogen sulfide onto the zeolite. In addition, the zeolite functions as a solid acid catalyst. Especially in high-temperature environments, polyolefin resin is decomposed on the surface of the zeolite, and the decomposed polyolefin resin penetrates into the interior of the zeolite through the pores and is further decomposed. The pore size of the zeolite is 5.5 Å or smaller, which prevents the polyolefin resin decomposed on the surface of the zeolite from penetrating into the interior of the zeolite through the pores, thereby suppressing further decomposition. Therefore, Sheet 1 possesses sufficient adsorption capacity for hydrogen sulfide while suppressing the decomposition of polyolefin resin even in high-temperature environments.

[0016] Furthermore, in all-solid-state batteries using sulfide-based solid electrolytes, it is conceivable to use a sheet containing substances that chemically react with hydrogen sulfide, such as metal oxides or metal hydroxides, as hydrogen sulfide adsorbents to remove hydrogen sulfide. However, using such substances as hydrogen sulfide adsorbents generates water as a byproduct. This water reacts with the sulfide-based solid electrolyte to generate hydrogen sulfide. On the other hand, sheet 1 contains zeolite as a hydrogen sulfide adsorbent. Zeolite physically adsorbs hydrogen sulfide, and unlike substances that chemically react with hydrogen sulfide, it does not generate water. Therefore, an all-solid-state battery using sheet 1 can suppress the leakage of hydrogen sulfide even if the outer casing is damaged.

[0017] Furthermore, when sheet 1 is used as a sealant layer for the exterior material of an all-solid-state battery, sheet 1 adsorbs moisture that penetrates from the edges of the sealant layer. As a result, the generation of hydrogen sulfide through reaction with the sulfide-based solid electrolyte is suppressed.

[0018] The binder contains a polyolefin resin. Examples of polyolefin resins include polyethylene resins and polypropylene resins. One type of polyolefin resin may be used alone, or two or more types may be used in combination.

[0019] When sheet 1 is for use in an all-solid-state battery, the operating temperature of the all-solid-state battery can reach up to approximately 120°C. Therefore, it is preferable that sheet 1 has heat resistance. For this reason, when sheet 1 is for use in an all-solid-state battery, it is preferable that the polyolefin resin be a polypropylene resin. The inventors' research has revealed that polypropylene resins are more susceptible to decomposition by zeolite than polyethylene resins. However, since the pore size of the zeolite in sheet 1 is 3.5 Å to 5.5 Å, decomposition can be suppressed even if the resin is a polypropylene resin. Therefore, when sheet 1 uses a polypropylene resin as the polyolefin resin, it will have excellent heat resistance while suppressing the decomposition of the polypropylene resin.

[0020] Examples of polyethylene resins include ethylene homopolymers and ethylene-α-olefin copolymers. The density of the polyethylene resin may be low, medium, or high.

[0021] Examples of polypropylene resins include propylene homopolymers, block or random copolymers containing propylene as a copolymer component, and propylene-α-olefin copolymers.

[0022] The stereoregularity of the polypropylene resin may be isotactic, syndiotactic, or atactic. From the viewpoint of heat resistance and chemical resistance, the polypropylene resin is preferably isotactic. When the polypropylene resin is isotactic, decomposition by zeolite proceeds more easily compared to when it is syndiotactic or atactic. However, since the pore size of the zeolite in sheet 1 is 3.5 Å to 5.5 Å, decomposition can be suppressed even if the polypropylene resin is isotactic. Therefore, when sheet 1 uses an isotactic polypropylene resin, it will have excellent heat resistance and chemical resistance while suppressing the decomposition of the polypropylene resin.

[0023] The polyolefin resin content may be 50% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, 95% by mass or more, 99% by mass or more, or 100% by mass, based on the total amount of the binder.

[0024] The polypropylene resin content may be 50% or more by mass, 60% or more by mass, 70% or more by mass, 80% or more by mass, 90% or more by mass, 95% or more by mass, 99% or more by mass, or 100% by mass, based on the total amount of binder. Sheet 1 has a zeolite pore size of 3.5 Å to 5.5 Å. Therefore, even if the polypropylene resin content is 50% or more by mass, Sheet 1 is less likely to deteriorate. In addition, having a polypropylene resin content of 50% or more by mass gives Sheet 1 excellent heat resistance.

[0025] The binder may contain thermoplastic resins other than polyolefin resins. Examples of such thermoplastic resins include polyester resins such as polyethylene terephthalate and polybutylene terephthalate.

[0026] The binder content may be 70 to 99.5% by mass, or 90 to 99% by mass, based on the total amount of sheet 1.

[0027] Hydrogen sulfide adsorbent materials include zeolite. Zeolite is SiO ４Tetrahedron and AlO ４ It is a crystalline aluminosilicate having a structure in which tetrahedrons and AlO share vertex oxygen and are connected three-dimensionally. Zeolite has a network structure. The composition formula of zeolite is 2 / xM·Al ２ O ３ ·mSiO ２ ·nH ２ O. In the formula, M represents a cation with a valence of x, and m represents the silica / alumina ratio (the ratio of the amount of substance of SiO ２ O ３ to the amount of substance of Al ２ O). The cation (M) is supported on the zeolite.

[0028] Examples of the cation (M) include zinc ion, silver ion, copper ion, calcium ion, potassium ion, sodium ion, manganese ion, cobalt ion, nickel ion, and ammonium ion. The cations contained in the zeolite preferably include zinc ion, silver ion, copper ion, calcium ion, and sodium ion because they can suppress the decomposition of the polyolefin resin while further improving the adsorption amount of hydrogen sulfide, more preferably zinc ion, silver ion, copper ion, and calcium ion, and still more preferably zinc ion, silver ion, and copper ion.

[0029] The pore size of the zeolite is preferably 3.5 Å or larger, more preferably 4.0 Å or larger, and even more preferably 5.0 Å or larger, as this further improves its adsorption of hydrogen sulfide. The pore size of the zeolite is preferably 5.5 Å or smaller, and more preferably 4.5 Å or smaller, as this further suppresses the decomposition of the polyolefin resin. The pore size of the zeolite may be a value obtained by measuring the amount of adsorption using argon gas, in accordance with JIS Z 8831-3 Part 3 "Method for measuring micropore size by gas adsorption". The pore size of the zeolite can be adjusted, for example, by adjusting the silica / alumina ratio or changing the cation (M). The pore size of the zeolite may be 3.5 Å or more and 4.5 Å or less, 4.0 Å or more and 4.5 Å or less, 3.5 Å or more and 5.0 Å or less, 4.0 Å or more and 5.0 Å or less, 3.5 Å or more and 5.5 Å or less, 4.0 Å or more and 5.5 Å or less, 4.5 Å or more and 5.5 Å or less, or 5.0 Å or more and 5.5 Å or less.

[0030] Examples of zeolite skeleton structures include type A (LTA type), ferrielite (FER type), ZSM-5 type (MFI type), modernanite type (MOR), Y type, and Z type (FAU type). Type A (LTA type) is preferred because it further improves adsorption to hydrogen sulfide and further suppresses the decomposition of polyolefin resins. The letters in parentheses represent skeleton codes that have been compiled into a database by the International Zeolite Association.

[0031] The silica / alumina ratio may be 20 or less, but is preferably 2.5 or less, more preferably 2.0 or less, and even more preferably 1.25 or less, as this further improves the adsorption of hydrogen sulfide and further suppresses the decomposition of polyolefin resins. The silica / alumina ratio may be 1 or more, or 1.5 or more. The silica / alumina ratio may be 1 to 1.25, 1 to 2.0, 1 to 2.5, 1 to 20, 1.5 to 2.0, 1.5 to 2.5, or 1.5 to 20.

[0032] The content of zeolite may be 50% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, 95% by mass or more, 99% by mass or more, or 100% by mass based on the total amount of the hydrogen sulfide adsorbent.

[0033] The content of the hydrogen sulfide adsorbent is preferably 0.5 to 30% by mass, more preferably 1 to 10% by mass based on the total amount of Sheet 1. When the content of the hydrogen sulfide adsorbent is 0.5% by mass or more, the adsorption amount of hydrogen sulfide tends to be more sufficient. When the content of the hydrogen sulfide adsorbent is 30% by mass or less, the appearance, moisture barrier property, and laminate strength when Sheets 1 are heat-sealed tend to be sufficient.

[0034] Sheet 1 may contain a polyolefin-based elastomer. The polyolefin-based elastomer may have compatibility with the above-mentioned polyolefin-based resin or may not have compatibility, but may contain both a compatible polyolefin-based elastomer having compatibility and an incompatible polyolefin-based elastomer not having compatibility. "Having compatibility" (compatibilized system) means dispersing in the binder with a dispersed phase size of 1 nm or more and less than 500 nm. "Not having compatibility" (incompatible system) means dispersing in the binder with a dispersed phase size of 500 nm or more and less than 20 μm.

[0035] When the polyolefin-based resin is a polypropylene-based resin, examples of the compatible polyolefin-based elastomer include a propylene-butene-1 random copolymer, and examples of the incompatible polyolefin-based elastomer include an ethylene-butene-1 random copolymer. The polyolefin-based elastomer can be used alone or in combination of two or more.

[0036] Further, Sheet 1 may contain, as additive components, for example, a slip agent, an anti-blocking agent, an antioxidant, a light stabilizer, a flame retardant, etc., and the content of these additive components is preferably 10 parts by mass or less when the total mass of Sheet 1 is 100 parts by mass.

[0037] The thickness of the sheet 1 is not particularly limited, but from the viewpoint of more effectively adsorbing hydrogen sulfide, it is preferably in the range of 5 to 300 μm, more preferably in the range of 10 to 200 μm, and still more preferably in the range of 20 to 100 μm.

[0038] The sheet 1 may be either single-layer or multi-layer, and may be selected according to the required functions.

[0039] The sheet 1 can be obtained, for example, by extruding a composition containing a binder and a hydrogen sulfide adsorbent using an extrusion laminator. When kneading the binder and the hydrogen sulfide adsorbent to obtain a composition, a dispersant may be added. Examples of the dispersant include metal salts such as magnesium stearate, zinc stearate, and sodium stearate. That is, the sheet 1 may contain a dispersant.

[0040] As described later, the sheet 1 may be included in a packaging bag. That is, the sheet 1 may be for a packaging bag. As described later, the sheet 1 may be included in a all-solid-state battery. That is, the sheet 1 may be for a all-solid-state battery. The sheet 1 may be included in a package containing a food that releases hydrogen sulfide as a content. That is, the sheet 1 may be for a package containing a food that releases hydrogen sulfide as a content.

[0041] As described above, the sheet according to one embodiment of the present disclosure has been described, but the sheet of the present disclosure is not limited to the above embodiment.

[0042] [Laminate] Hereinafter, an exterior material for a solid-state battery will be described as an exterior material (laminated) for a solid-state battery according to one embodiment of the present disclosure. Figure 2 is a schematic cross-sectional view showing an exterior material (laminated) for a solid-state battery according to the present embodiment. As shown in Figure 2, the exterior material 10 of this embodiment is a laminate in which a base layer 11, a first adhesive layer 12a provided on one side of the base layer 11, a barrier layer 13 provided on the side of the first adhesive layer 12a opposite to the base layer 11 and having first and second corrosion prevention treatment layers 14a and 14b on both sides, a second adhesive layer 12b provided on the side of the barrier layer 13 opposite to the first adhesive layer 12a, and a sealant layer 16 provided on the side of the second adhesive layer 12b opposite to the barrier layer 13. Here, the first corrosion prevention treatment layer 14a is provided on the side of the barrier layer 13 that is on the base layer 11 side, and the second corrosion prevention treatment layer 14b is provided on the side of the barrier layer 13 that is on the sealant layer 16 side. In the exterior material 10, the base layer 11 is the outermost layer, and the sealant layer 16 is the innermost layer. That is, the exterior material 10 is used with the base layer 11 facing the outside of the all-solid-state battery and the sealant layer 16 facing the inside of the all-solid-state battery. The sealant layer 16 is the sheet 1 according to the above embodiment. Each layer constituting the exterior material 10 will be described in detail below.

[0043] <Base Layer 11> The base layer 11 provides heat resistance during the sealing process when manufacturing solid-state batteries and plays a role in suppressing the occurrence of pinholes that may occur during molding and distribution. In particular, for exterior materials of large solid-state batteries, it can also provide scratch resistance, chemical resistance, and insulation.

[0044] The base layer 11 is preferably a layer formed of an insulating resin. Suitable resins include polyester resin, polyamide resin, polyimide resin, polyamide-imide resin, polyetherketone resin, polyphenylene sulfide resin, polyetherimide resin, polysulfone resin, fluororesin, phenolic resin, melamine resin, urethane resin, allyl resin, silicone resin, epoxy resin, furan resin, acetylcellulose resin, and the like.

[0045] When applied to the substrate layer 11, these resins may be in the form of stretched or unstretched films, or as coating films. The substrate layer 11 may be single-layer or multi-layer, and in the case of multi-layer, different resins can be used in combination. For films, co-extruded films or films laminated with an adhesive can be used. For coating films, films coated multiple times can be used, and multi-layer films can be created by combining films and coating films.

[0046] Among these resins, polyester resins and polyamide resins are preferred as the base layer 11 due to their excellent moldability. Examples of polyester resins include polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate. Examples of polyamide resins that constitute the polyamide film include nylon 6, nylon 6,6, copolymers of nylon 6 and nylon 6,6, nylon 6, nylon 9T, nylon 10, polymetaxylylene adipamide (MXD6), nylon 11, nylon 12, etc.

[0047] When these resins are used in film form, a biaxially oriented film is preferred. Examples of stretching methods for biaxially oriented films include sequential biaxial stretching, tubular biaxial stretching, and simultaneous biaxial stretching. From the viewpoint of obtaining better deep-drawing moldability, a biaxially oriented film is preferably stretched by tubular biaxial stretching.

[0048] The thickness of the base layer 11 is preferably 6 to 40 μm, and more preferably 10 to 30 μm. A base layer thickness of 6 μm or more tends to improve the pinhole resistance and insulation properties of the exterior material 10. When the thickness of the base layer 11 exceeds 40 μm, the total thickness of the exterior material 10 tends to increase.

[0049] The melting peak temperature of the base layer 11 is preferably higher than the melting peak temperature of the sealant layer 16, and more preferably 30°C or more higher than the melting peak temperature of the sealant layer 16, in order to suppress deformation of the base layer 11 during sealing.

[0050] <First adhesive layer 12a> The first adhesive layer 12a is a layer that adheres the base layer 11 and the barrier layer 13. Specifically, the material constituting the first adhesive layer 12a may be a polyurethane resin obtained by reacting a bifunctional or more isocyanate compound (polyfunctional isocyanate compound) with a main component such as a polyester polyol, polyether polyol, acrylic polyol, or carbonate polyol. The various polyols mentioned above can be used alone or in combination of two or more, depending on the function and performance required of the exterior material 10. In addition, epoxy resins with a curing agent added as the main component can also be used, but are not limited to these. Furthermore, depending on the performance required of the adhesive, various other additives and stabilizers may be added to the adhesive mentioned above.

[0051] The thickness of the first adhesive layer 12a is not particularly limited, but from the viewpoint of obtaining desired adhesive strength, conformability, and processability, for example, it is preferably 1 to 10 μm, and more preferably 2 to 7 μm.

[0052] <Barrier Layer 13> The barrier layer 13 has water vapor barrier properties that prevent moisture from entering the interior of the all-solid-state battery. The barrier layer 13 may also have ductility for deep drawing. As the barrier layer 13, for example, various metal foils such as aluminum, stainless steel, and copper, or metal vapor-deposited films, inorganic oxide vapor-deposited films, carbon-containing inorganic oxide vapor-deposited films, or films provided with these vapor-deposited films can be used. As films provided with vapor-deposited films, for example, aluminum vapor-deposited films and inorganic oxide vapor-deposited films can be used. These can be used individually or in combination of two or more types. As the barrier layer 13, metal foil is preferred in terms of mass (specific gravity), moisture resistance, processability and cost, and aluminum foil is more preferred. In the outer material 10, the sheet 1 contains zeolite with a pore size of 3.5 Å to 5.5 Å. Since this zeolite adsorbs hydrogen sulfide, aluminum foil, which is susceptible to corrosion by hydrogen sulfide, can be suitably used in the outer material 10.

[0053] As for the aluminum foil, soft aluminum foil that has undergone annealing treatment is particularly preferred because it can provide the desired ductility during molding. However, it is even more preferable to use aluminum foil containing iron in order to provide further pinhole resistance and ductility during molding. The iron content in the aluminum foil is preferably 0.1 to 9.0% by mass, and more preferably 0.5 to 2.0% by mass, of 100% by mass of aluminum foil. By having an iron content of 0.1% by mass or more, an exterior material 10 with superior pinhole resistance and ductility can be obtained. By having an iron content of 9.0% by mass or less, an exterior material 10 with superior flexibility can be obtained. As for the aluminum foil, untreated aluminum foil may be used, but it is preferable to use degreased aluminum foil in order to provide corrosion resistance. When degreasing the aluminum foil, the degreasing treatment may be applied to only one side of the aluminum foil, or to both sides. "100% by mass of aluminum foil" is synonymous with "based on the total amount of aluminum foil".

[0054] The thickness of the barrier layer 13 is not particularly limited, but is preferably 9 to 200 μm, more preferably 15 to 100 μm, even more preferably 30 to 80 μm, and particularly preferably 40 to 60 μm, considering barrier properties, pinhole resistance, and processability.

[0055] The thickness of the aluminum foil is not particularly limited, but considering barrier properties, pinhole resistance, and processability, it is preferably 9 to 200 μm, more preferably 15 to 100 μm, even more preferably 30 to 80 μm, and particularly preferably 40 to 60 μm.

[0056] <First and Second Corrosion Prevention Treatment Layers 14a, 14b> The first and second corrosion prevention treatment layers 14a and 14b are layers provided to prevent corrosion of the metal foil (metal foil layer) and the like that which constitute the barrier layer 13. The first corrosion prevention treatment layer 14a also plays a role in increasing the adhesion between the barrier layer 13 and the first adhesive layer 12a. The second corrosion prevention treatment layer 14b also plays a role in increasing the adhesion between the barrier layer 13 and the second adhesive layer 12b. The first corrosion prevention treatment layer 14a and the second corrosion prevention treatment layer 14b may be layers with the same composition or layers with different compositions. The first and second corrosion prevention treatment layers 14a and 14b (hereinafter also simply referred to as "corrosion prevention treatment layers 14a and 14b") may be formed by, for example, degreasing, hot water modification, anodizing, chemical conversion, or a combination of these treatments.

[0057] Degreasing treatments include acid degreasing and alkaline degreasing. Acid degreasing methods include using inorganic acids such as sulfuric acid, nitric acid, hydrochloric acid, and hydrofluoric acid individually, or mixtures thereof. Furthermore, as an acid degreasing method, using an acid degreasing agent obtained by dissolving a fluorine-containing compound such as ammonium monohydrogen-difluoride in the above-mentioned inorganic acid not only provides a degreasing effect on aluminum, especially when aluminum foil is used for the barrier layer 13, but also allows the formation of a passive aluminum fluoride, which is effective in terms of corrosion resistance. Alkaline degreasing methods include using sodium hydroxide, etc.

[0058] Examples of hydrothermal alteration treatments include the boehmite treatment, which involves immersing aluminum foil in boiling water to which triethanolamine has been added. Examples of anodizing treatments include the anodizing treatment.

[0059] Chemical treatments can be immersion-type or coating-type. Immersion-type chemical treatments include, for example, chromate treatment, zirconium treatment, titanium treatment, vanadium treatment, molybdenum treatment, calcium phosphate treatment, strontium hydroxide treatment, cerium treatment, ruthenium treatment, or various chemical treatments consisting of mixed phases of these. On the other hand, a coating-type chemical treatment is a method of applying a coating agent having corrosion-preventive properties onto the barrier layer 13.

[0060] Of these corrosion prevention treatments, if at least a portion of the corrosion prevention treatment layer is formed by hot water modification, anodizing, or chemical conversion, it is preferable to perform the degreasing treatment described above beforehand. Furthermore, if a degreased metal foil, such as a metal foil that has undergone an annealing process, is used as the barrier layer 13, it is not necessary to perform degreasing treatment again when forming the corrosion prevention treatment layers 14a and 14b.

[0061] The coating agent used in the coating-type chemical conversion treatment preferably contains trivalent chromium. The coating agent may also contain at least one polymer selected from the group consisting of cationic polymers and anionic polymers, as described later.

[0062] Furthermore, in particular, the hydrothermal alteration treatment and anodic oxidation treatment among the above treatments dissolve the surface of the aluminum foil with a treatment agent, forming aluminum compounds (boehmite, anodized aluminum) with excellent corrosion resistance. As a result, a co-continuous structure is formed from the barrier layer 13 using aluminum foil to the corrosion-preventive treatment layers 14a and 14b, and therefore the above treatment is included in the definition of chemical conversion treatment. On the other hand, as will be described later, it is also possible to form the corrosion-preventive treatment layers 14a and 14b using only a pure coating method that is not included in the definition of chemical conversion treatment. One example of this method is to use a sol of a rare earth element oxide such as cerium oxide with an average particle size of 100 nm or less, which has an aluminum corrosion-preventive effect (inhibitor effect) and is also environmentally suitable. By using this method, it is possible to impart a corrosion-preventive effect to metal foils such as aluminum foil even with a general coating method.

[0063] Examples of sols for the above-mentioned rare earth element oxides include sols using various solvents such as aqueous, alcoholic, hydrocarbon, ketone, ester, and ether-based solvents. Among these, aqueous sols are preferred.

[0064] In the sols of the rare earth element oxides mentioned above, inorganic acids such as nitric acid, hydrochloric acid, and phosphoric acid, or their salts, or organic acids such as acetic acid, malic acid, ascorbic acid, and lactic acid are usually used as dispersion stabilizers to stabilize their dispersion. Of these dispersion stabilizers, phosphoric acid in particular is expected to provide the following benefits in the exterior material 10: (1) stabilization of sol dispersion, (2) improved adhesion with the barrier layer 13 by utilizing the aluminum chelating ability of phosphoric acid, (3) imparting corrosion resistance by capturing aluminum ions (passivation), and (4) improved cohesive force of the corrosion prevention treatment layers (oxide layers) 14a and 14b due to the ease with which dehydration condensation of phosphoric acid occurs even at low temperatures.

[0065] The corrosion-preventive treatment layers 14a and 14b formed by the above-mentioned rare earth element oxide sols are aggregates of inorganic particles, and therefore, even after the drying and curing process, the cohesive force of the layers themselves may decrease. Therefore, in this case, it is preferable that the corrosion-preventive treatment layers 14a and 14b are compounded with an anionic polymer or a cationic polymer to compensate for the cohesive force.

[0066] The corrosion-preventive treatment layers 14a and 14b are not limited to the layers described above. For example, they may be formed using a treatment agent that combines a resin binder (such as aminophenol) with phosphoric acid and a chromium compound, as is known with coated chromate. Using this treatment agent, a layer can be formed that possesses both corrosion-preventive function and adhesion. Furthermore, although it is necessary to consider the stability of the coating liquid, a layer can be formed that possesses both corrosion-preventive function and adhesion by using a coating agent that pre-mixes a rare earth element oxide sol with a polycationic polymer or a polyanionic polymer into a single liquefaction.

[0067] The mass per unit area of ​​the corrosion-preventive treatment layers 14a and 14b is 0.005 to 0.200 g / m², regardless of whether it is a multilayer or single-layer structure. ２ Preferably, 0.010 to 0.100 g / m ２A more preferable mass per unit area is 0.005 g / m². ２ If the above is true, it is easier to impart corrosion prevention function to the barrier layer 13. Also, the above mass per unit area is 0.200 g / m². ２ Even beyond this limit, the corrosion prevention function does not change significantly. On the other hand, when using rare earth element oxide sols, if the coating film is thick, the heat during drying may result in insufficient curing, potentially leading to a decrease in cohesive force. The thickness of the corrosion prevention treatment layers 14a and 14b can be calculated from their specific gravity.

[0068] From the viewpoint of making it easier to maintain adhesion between the sealant layer and the barrier layer, the corrosion-preventive treatment layers 14a and 14b may, for example, contain cerium oxide, 1 to 100 parts by mass of phosphoric acid or phosphate per 100 parts by mass of cerium oxide, and a cationic polymer; they may be formed by applying a chemical conversion treatment to the barrier layer 13; or they may be formed by applying a chemical conversion treatment to the barrier layer 13 and also contain a cationic polymer.

[0069] <Second adhesive layer 12b> The second adhesive layer 12b is a layer that adheres the barrier layer 13 and the sealant layer 16. A general adhesive for adhering the barrier layer 13 and the sealant layer 16 can be used for the second adhesive layer 12b.

[0070] If a corrosion-preventive treatment layer 14b is provided on the barrier layer 13, and the second corrosion-preventive treatment layer 14b has a layer containing at least one polymer selected from the group consisting of cationic polymers and anionic polymers described above, it is preferable that the second adhesive layer 12b is a layer containing a compound that is reactive with the polymer contained in the second corrosion-preventive treatment layer 14b (hereinafter also referred to as "reactive compound").

[0071] For example, if the second corrosion-preventive treatment layer 14b contains a cationic polymer, the second adhesive layer 12b contains a compound that is reactive with the cationic polymer. If the second corrosion-preventive treatment layer 14b contains an anionic polymer, the second adhesive layer 12b contains a compound that is reactive with the anionic polymer. Furthermore, if the second corrosion-preventive treatment layer 14b contains both a cationic polymer and an anionic polymer, the second adhesive layer 12b contains a compound that is reactive with the cationic polymer and a compound that is reactive with the anionic polymer. However, the second adhesive layer 12b does not necessarily have to contain the above two types of compounds, and may contain a compound that is reactive with both the cationic polymer and the anionic polymer. Here, "reactive" means forming a covalent bond with the cationic polymer or the anionic polymer. The second adhesive layer 12b may further contain an acid-modified polyolefin resin.

[0072] Compounds that react with cationic polymers include at least one compound selected from the group consisting of polyfunctional isocyanate compounds, glycidyl compounds, compounds having a carboxyl group, and compounds having an oxazoline group.

[0073] Examples of these polyfunctional isocyanate compounds, glycidyl compounds, compounds having a carboxyl group, and compounds having an oxazoline group include the polyfunctional isocyanate compounds, glycidyl compounds, compounds having a carboxyl group, and compounds having an oxazoline group that were previously exemplified as crosslinking agents for creating a crosslinked structure of cationic polymers. Among these, polyfunctional isocyanate compounds are preferred because they have high reactivity with cationic polymers and readily form crosslinked structures.

[0074] Compounds that react with anionic polymers include at least one compound selected from the group consisting of glycidyl compounds and compounds having an oxazoline group. Examples of these glycidyl compounds and compounds having an oxazoline group include the glycidyl compounds and compounds having an oxazoline group that were previously exemplified as crosslinking agents for creating a crosslinked structure of cationic polymers. Among these, glycidyl compounds are preferred due to their high reactivity with anionic polymers.

[0075] When the second adhesive layer 12b contains an acid-modified polyolefin resin, it is preferable that the reactive compound is also reactive with the acidic groups in the acid-modified polyolefin resin (i.e., forms a covalent bond with the acidic groups). This improves adhesion to the second corrosion-preventive treatment layer 14b. In addition, the acid-modified polyolefin resin becomes a cross-linked structure, improving the solvent resistance of the exterior material 10.

[0076] The content of the reactive compound is preferably equal to or 10 times the amount of the acidic groups in the acid-modified polyolefin resin. If the amount is equal to or greater than the amount, the reactive compound will react sufficiently with the acidic groups in the acid-modified polyolefin resin. On the other hand, if the amount is 10 times or less, the remaining unreacted material in the crosslinking reaction with the acid-modified polyolefin resin can be suppressed, and the deterioration of various performances can be suppressed. Therefore, for example, the content of the reactive compound is preferably 5 to 20 parts by mass (solid content ratio) per 100 parts by mass of the acid-modified polyolefin resin.

[0077] Acid-modified polyolefin resin is a polyolefin resin into which acidic groups have been introduced. Examples of acidic groups include carboxyl groups, sulfonic acid groups, and acid anhydride groups, with maleic anhydride groups and (meth)acrylic acid groups being particularly preferred. As the acid-modified polyolefin resin, for example, the same type as the modified polyolefin resin used in the sealant layer 16 can be used.

[0078] The second adhesive layer 12b may contain various additives such as flame retardants, slip agents, antiblocking agents, antioxidants, light stabilizers, and tackifiers.

[0079] The second adhesive layer 12b may, from the viewpoint of suppressing a decrease in laminate strength when corrosive gases such as hydrogen sulfide or electrolytes are involved, and from the viewpoint of suppressing a decrease in insulating properties, for example, contain an acid-modified polyolefin and at least one curing agent selected from the group consisting of a polyfunctional isocyanate compound, a glycidyl compound, a compound having a carboxyl group, a compound having an oxazoline group, and a carbodiimide compound. Examples of carbodiimide compounds include N,N'-di-o-toluylcarbodiimide, N,N'-diphenylcarbodiimide, N,N'-di-2,6-dimethylphenylcarbodiimide, N,N'-bis(2,6-diisopropylphenyl)carbodiimide, N,N'-dioctyldecylcarbodiimide, N-triyl-N'-cyclohexylcarbodiimide, N,N'-di-2,2-di-t-butylphenylcarbodiimide, N-triyl-N'-phenylcarbodiimide, N,N'-di-p-nitrophenylcarbodiimide, N,N'-di-p-aminophenylcarbodiimide, N,N'-di-p-hydroxyphenylcarbodiimide, N,N'-di-cyclohexylcarbodiimide, and N,N'-di-p-toluylcarbodiimide.

[0080] Furthermore, as the adhesive forming the second adhesive layer 12b, for example, a polyurethane-based adhesive containing a polyester polyol composed of hydrogenated dimer fatty acids and a diol, and a polyisocyanate can be used. Examples of adhesives include polyurethane resins obtained by reacting a bifunctional or more isocyanate compound with a main component such as a polyester polyol, polyether polyol, acrylic polyol, or carbonate polyol, and epoxy resins obtained by reacting an amine compound with a main component having epoxy groups, which are preferred from the viewpoint of heat resistance.

[0081] The thickness of the second adhesive layer 12b is not particularly limited, but from the viewpoint of obtaining the desired adhesive strength and processability, it is preferably 1 to 10 μm, and more preferably 2 to 7 μm.

[0082] <Sealant Layer 16> The sealant layer 16 is a layer that provides heat sealing properties to the exterior material 10, and is placed on the inside and heat-sealed (heat-fused) during the assembly of the all-solid-state battery. The sealant layer 16 is the sheet 1 according to the above embodiment.

[0083] Although a laminate according to one embodiment of the present disclosure has been described above, the laminate of the present disclosure is not limited to the above embodiment.

[0084] For example, Figure 2 shows a case where the barrier layer 13 and the sealant layer 16 are laminated using a second adhesive layer 12b, but the barrier layer 13 and the sealant layer 16 may also be laminated using an adhesive resin layer 15, as in the all-solid-state battery exterior material (laminated) shown in Figure 3. In addition, in the all-solid-state battery exterior material 20 shown in Figure 3, a second adhesive layer 12b may be provided between the barrier layer 13 and the adhesive resin layer 15.

[0085] <Adhesive Resin Layer 15> The adhesive resin layer 15 is generally composed of an adhesive resin composition as the main component and additive components as needed. The adhesive resin composition is not particularly limited, but it is preferable to include a modified polyolefin resin.

[0086] The modified polyolefin resin is preferably a polyolefin resin that has been graft-modified with an unsaturated carboxylic acid, or an unsaturated carboxylic acid derivative derived from either its acid anhydride or ester.

[0087] Examples of polyolefin resins include low-density polyethylene, medium-density polyethylene, high-density polyethylene, ethylene-α-olefin copolymer, homopolypropylene, block polypropylene, random polypropylene, and propylene-α-olefin copolymer.

[0088] The modified polyolefin resin is preferably a polyolefin resin modified with maleic anhydride. Suitable modified polyolefin resins include, for example, "Admer" manufactured by Mitsui Chemicals, Inc. and "Modic" manufactured by Mitsubishi Chemical Corporation. Such modified polyolefin resins exhibit excellent reactivity with various metals and polymers having various functional groups, and this reactivity can be used to impart adhesion to the adhesive resin layer 15. The adhesive resin layer 15 may also contain various additives as needed, such as various compatible and incompatible elastomers, flame retardants, slip agents, antiblocking agents, antioxidants, light stabilizers, and tackifiers.

[0089] The thickness of the adhesive resin layer 15 is not particularly limited, but from the viewpoint of stress relaxation and moisture permeability, it is preferable that it be the same as or less than that of the sealant layer 16.

[0090] Furthermore, in the exterior material 20 for all-solid-state batteries, the total thickness of the adhesive resin layer 15 and the sealant layer 16 is preferably in the range of 5 to 100 μm, and more preferably in the range of 20 to 80 μm, from the viewpoint of achieving both thinning and improved heat seal strength in high-temperature environments.

[0091] Furthermore, the laminate of this disclosure may further include a protective layer 17 disposed on the surface of the base layer 11 opposite to the barrier layer 13 side, as shown in Figure 4, for the exterior material (laminated) 25 for all-solid-state batteries. In Figure 4, the adhesive resin layer 15 may be a second adhesive layer 12b.

[0092] <Protective Layer 17> The protective layer 17 is a layer that protects the base layer 11. The same material as the first adhesive layer 12a can be used to make up the protective layer 17. The protective layer 17 can be formed on the base layer 11 by coating or the like.

[0093] Furthermore, although Figure 2 shows the laminate of this disclosure with corrosion-preventive treatment layers 14a and 14b provided on both sides of the barrier layer 13, only one of the corrosion-preventive treatment layers 14a and 14b may be provided, or the corrosion-preventive treatment layer may not be provided at all. Also, although Figure 2 shows the laminate of this disclosure with a second adhesive layer 12b, the second adhesive layer 12b may not be provided.

[0094] Furthermore, although Figure 2 shows a laminate of the present disclosure that includes a second adhesive layer 12b and corrosion-preventive treatment layers 14a, 14b, these layers may not be included, as is the case with the all-solid-state battery exterior material (laminated) 30 shown in Figure 5. In other words, the exterior material 30 includes a base layer 11 and a sealant layer 16 (sheet 1).

[0095] Furthermore, although Figure 2 shows a laminate of the present disclosure comprising a first adhesive layer 12a, a second adhesive layer 12b, a barrier layer 13, and corrosion prevention treatment layers 14a, 14b, these layers may not be included, as is the case with the all-solid-state battery exterior material (laminated) 35 shown in Figure 6. In other words, the exterior material 35 comprises a base layer 11, a first adhesive layer 12a, a barrier layer 13, and a sealant layer 16 (sheet 1).

[0096] [Method for Manufacturing the Laminate] Hereinafter, an example of a method for manufacturing the exterior material 10 shown in Figure 2 will be described as a method for manufacturing the laminate according to one embodiment of the present disclosure. However, the method for manufacturing the exterior material 10 is not limited to the following method.

[0097] The manufacturing method for the exterior material 10 of this embodiment generally includes the steps of: providing corrosion prevention treatment layers 14a and 14b on the barrier layer 13; bonding the base material layer 11 and the barrier layer 13 using a first adhesive layer 12a; further laminating a sealant layer 16 via a second adhesive layer 12b to produce a laminate; and, if necessary, aging the obtained laminate.

[0098] (Lamination process of corrosion prevention treatment layers 14a and 14b onto the barrier layer 13) This process involves forming corrosion prevention treatment layers 14a and 14b on the barrier layer 13. As described above, methods for doing so include degreasing, hot water modification, anodizing, chemical conversion, or applying a coating agent with corrosion prevention properties to the barrier layer 13.

[0099] Furthermore, if the corrosion prevention treatment layers 14a and 14b are multilayered, for example, the coating liquid (coating agent) constituting the lower layer (barrier layer 13 side) of the corrosion prevention treatment layer can be applied to the barrier layer 13 and baked to form the first layer, and then the coating liquid (coating agent) constituting the upper layer of the corrosion prevention treatment layer can be applied to the first layer and baked to form the second layer.

[0100] Degreasing can be performed by spraying or immersion. Hot water modification and anodizing can be performed by immersion. For chemical conversion treatments, immersion, spraying, coating, etc., can be appropriately selected depending on the type of chemical conversion treatment.

[0101] Various methods can be used for applying coatings with corrosion-preventive properties, including gravure coating, reverse coating, roll coating, and bar coating.

[0102] As described above, the various treatments may be applied to either both sides or one side of the metal foil, but in the case of single-sided treatment, it is preferable that the treated surface be the side on which the sealant layer 16 is laminated. Furthermore, the above treatment may also be applied to the surface of the base layer 11, if required.

[0103] Furthermore, the amount of coating agent applied to form both the first and second layers is 0.005 to 0.200 g / m². ２ Preferably, 0.010 to 0.100 g / m ２ This is preferable.

[0104] Furthermore, if drying curing is required, it can be carried out at a base material temperature in the range of 60 to 300°C, depending on the drying conditions of the corrosion-preventive treatment layers 14a and 14b used.

[0105] (Bonding process between base layer 11 and barrier layer 13) This process involves bonding the barrier layer 13, which is provided with corrosion-preventive treatment layers 14a and 14b, to the base layer 11 via a first adhesive layer 12a. The bonding method involves using techniques such as dry lamination, non-solvent lamination, or wet lamination, and bonding the two using the material that constitutes the first adhesive layer 12a described above. The dry application amount of the first adhesive layer 12a is 1 to 10 g / m². ２ In the range of 2 to 7 g / m², more preferably 2 to 7 g / m² ２ It will be established within the range of [this].

[0106] (Lamination process of the second adhesive layer 12b and sealant layer 16) This process involves bonding the sealant layer 16 to the second corrosion prevention treatment layer 14b side of the barrier layer 13 via the second adhesive layer 12b. Methods of bonding include wet processes and dry lamination.

[0107] In the wet process, a solution or dispersion of the adhesive constituting the second adhesive layer 12b is applied onto the second corrosion-preventive treatment layer 14b, and the solvent is evaporated at a predetermined temperature to form a dry film, or a baking treatment is performed as needed after drying. After that, a sealant layer 16 is laminated to manufacture the exterior material 10. Examples of coating methods include the various coating methods exemplified above. The preferred dry coating amount of the second adhesive layer 12b is the same as that of the first adhesive layer 12a.

[0108] In this case, the sealant layer 16 can be manufactured, for example, by a melt extrusion molding machine using a sheet-forming resin composition containing the components of the sheet 1 described above. From the viewpoint of productivity, the processing speed of the melt extrusion molding machine can be set to 80 m / min or more.

[0109] (Aging Process) This process involves aging (curing) the laminate. Aging the laminate promotes adhesion between the barrier layer 13, the second corrosion-preventive treatment layer 14b, the second adhesive layer 12b, and the sealant layer 16. The aging process can be carried out in a temperature range of room temperature to 100°C. The aging time is, for example, 1 to 10 days.

[0110] In this way, the exterior material 10 according to the above embodiment, as shown in Figure 2, can be manufactured.

[0111] Next, an example of a manufacturing method for the exterior material 20 shown in Figure 3 will be described. Note that the manufacturing method for the exterior material 20 is not limited to the method described below.

[0112] The manufacturing method for the exterior material 20 of this embodiment generally includes the steps of: providing corrosion-preventive treatment layers 14a and 14b on the barrier layer 13; bonding the base layer 11 and the barrier layer 13 using the first adhesive layer 12a; further laminating the adhesive resin layer 15 and the sealant layer 16 to produce a laminate; and, if necessary, heat-treating the obtained laminate. Note that the steps up to bonding the base layer 11 and the barrier layer 13 can be carried out in the same manner as the manufacturing method for the exterior material 10 described above.

[0113] (Lamination process of adhesive resin layer 15 and sealant layer 16) This process involves forming an adhesive resin layer 15 and a sealant layer 16 on the second corrosion-preventive treatment layer 14b formed in the previous process. One method for this is to sand-laminate the adhesive resin layer 15 together with the sealant layer 16 using an extrusion laminating machine. Furthermore, lamination is also possible by tandem lamination or co-extrusion, in which the adhesive resin layer 15 and the sealant layer 16 are extruded. In forming the adhesive resin layer 15 and the sealant layer 16, for example, each component is blended to satisfy the above-described configuration of the adhesive resin layer 15 and sealant layer 16. The above-described sheet-forming resin composition is used to form the sealant layer 16.

[0114] This process yields a laminate in which the layers are stacked in the following order, as shown in Figure 3: base material layer 11 / first adhesive layer 12a / first corrosion prevention treatment layer 14a / barrier layer 13 / second corrosion prevention treatment layer 14b / adhesive resin layer 15 / sealant layer 16.

[0115] The adhesive resin layer 15 may be laminated by directly extruding the dry-blended material using an extrusion laminating machine to achieve the material composition described above. Alternatively, the adhesive resin layer 15 may be laminated by extruding the granulated material, which has been melt-blended using a melt-kneading device such as a single-screw extruder, twin-screw extruder, or Brabender mixer, using an extrusion laminating machine.

[0116] The sealant layer 16 may be laminated by directly extruding a dry-blended material, which has been used as a component of the sheet-forming resin composition to achieve the above-described material composition, using an extrusion laminating machine. Alternatively, the adhesive resin layer 15 and the sealant layer 16 may be laminated using a tandem lamination method or co-extrusion method, in which the adhesive resin layer 15 and the sealant layer 16 are extruded using an extrusion laminating machine after melt-blending the granulated material using a melt-kneading device such as a single-screw extruder, twin-screw extruder, or Brabender mixer. Furthermore, a single sealant film may be prepared in advance as a cast film using the sheet-forming resin composition, and this film may be laminated together with the adhesive resin by sand lamination. From the viewpoint of productivity, the formation speed (processing speed) of the adhesive resin layer 15 and the sealant layer 16 can be, for example, 80 m / min or more.

[0117] (Heat Treatment Process) This process involves heat-treating the laminate. Heat-treating the laminate improves the adhesion between the barrier layer 13, the second corrosion-preventive treatment layer 14b, the adhesive resin layer 15, and the sealant layer 16. Preferably, the heat treatment is performed at a temperature at least equal to or greater than the melting point of the adhesive resin layer 15.

[0118] In this way, the exterior material 20 of this embodiment, as shown in Figure 3, can be manufactured.

[0119] Although a method for manufacturing a laminate according to one embodiment has been described above, the method for manufacturing a laminate according to this disclosure is not limited to the above embodiment.

[0120] [Packaging Bag] A packaging bag according to one embodiment will be described below. Figure 7 is a schematic plan view of an example of a packaging bag according to this embodiment. The packaging bag 40 includes a laminate 10. The packaging bag 40 is formed into a bag shape, for example, by sealing the ends of a laminate 10 that has been folded in half.

[0121] The packaging bag 40 is a three-sided bag having a main body portion 41 in which the contents are contained, a folded portion 42 in which the laminate 10 is folded, and a sealing portion 43 located at the end of the main body portion 41. The shape of the main body portion 41 is not particularly limited, and for example, it may be rectangular when viewed from a predetermined direction. At least a part of the outer surface of the main body portion 41 may be printed. The main body portion 41 may contain, for example, a specific gas such as nitrogen in addition to the contents. The sealing portion 43 is the part in which a part of the sealant layer 70 of the laminate 10 is bonded to the other part. In the sealing portion 43, a part of the sealant layer 70 of the laminate 10 and the other part are in close contact with each other. The sealing portion 43 is formed, for example, by heating and compressing a part of the sealant layer 70 of the laminate 10 (i.e., heat sealing), but is not limited to this. For example, the sealing portion 43 may be formed by cold sealing or the like. In the packaging bag 40, the folded portion 42 forms one side of the main body portion 41, and the sealing portion 43 forms the remaining three sides of the main body portion 41. The ends of the folded portion 42 and the sealing portion 43 overlap.

[0122] The packaging bag 40 may also be used for applications involving heat treatment at 80°C or higher. Examples of heat treatments include retort processing and boiling.

[0123] Retorting is a method of sterilization used to preserve food, pharmaceuticals, etc., by heating and pressurizing to eliminate microorganisms such as mold, yeast, and bacteria. Typically, the packaging bags containing the food are heated and pressurized at 105-140°C and 0.15-0.30 MPa for 10-120 minutes. Retorting equipment comes in two types: steam-type, which uses heated steam, and hot water-type, which uses pressurized heated water. The appropriate type is used depending on the sterilization requirements for the food contents. Boiling is a method of moist heat sterilization used to preserve food, pharmaceuticals, etc. Typically, depending on the contents, the packaging bags containing the food are moist heat sterilized at 60-100°C and atmospheric pressure for 10-120 minutes. Boiling is usually performed at a temperature of 100°C or lower using a hot water bath. There are two methods: a batch method, where the contents are immersed in a hot water bath at a constant temperature for a certain period of time before being removed, and a continuous method, where the contents are passed through a tunnel-type hot water bath.

[0124] The height of the packaging bag may be 120 mm or more, and may be 160 mm or less. Preferably, the height of the packaging bag is 140 mm or less, and more preferably 125 mm or less. This reduces the volume of contents contained in the packaging bag, and tends to improve tear resistance and vibration resistance while maintaining ease of peeling of the printed layer.

[0125] The width of the packaging bag may be 80 mm or more, and may be 120 mm or less. Preferably, the width of the packaging bag is 100 mm or less, and more preferably 90 mm or less. This reduces the volume of contents contained in the packaging bag, and tends to improve tear resistance and vibration resistance while maintaining ease of peeling of the printed layer.

[0126] The capacity of the packaging bag may be, for example, 30 mL or more, 40 mL or more, or 50 mL or more. Preferably, the capacity of the packaging bag is 90 mL or less, more preferably 70 mL or less, and even more preferably 50 mL or less. This reduces the volume of contents contained in the packaging bag, which tends to improve tear resistance and vibration resistance while maintaining the ease of peeling off the printed layer.

[0127] Although a packaging bag according to one embodiment has been described above, the packaging bag of this disclosure is not limited to the above embodiment. For example, the packaging bag may be a standing pouch, a two-sided bag, a four-sided bag, a gusseted bag, or a fold-over bag. In addition, other laminates of this disclosure may be used instead of the laminate 10.

[0128] [Packaging] Hereinafter, a solid-state battery will be described as packaging according to one embodiment of the present disclosure. Figure 8 is a perspective view of a solid-state battery (packaging) according to the present embodiment. As shown in Figure 8, the solid-state battery 50 is composed of a battery element 52, two metal terminals (current extraction terminals) 53 for extracting current from the battery element 52 to the outside, and an outer material (laminated) 10 that encloses the battery element 52 in an airtight state. The outer material 10 is the outer material 10 according to the above embodiment and is used as a packaging bag for housing the battery element 52. In the outer material 10, the base material layer 11 is the outermost layer, and the sealant layer 16 is the innermost layer. That is, the outer material 10 is configured to enclose the battery element 52 inside by folding one laminate film in half and heat-sealing the peripheral edge, or by overlapping two laminate films and heat-sealing the peripheral edge, so that the base material layer 11 is on the outside side of the solid-state battery 50 and the sealant layer 16 is on the inside side of the solid-state battery 50. In other words, the battery element 52 is the contents housed in the packaging bag. The metal terminals 53 are sandwiched and sealed by the outer packaging material 10, which forms the container with the sealant layer 16 on the inside. The metal terminals 53 may also be sandwiched by the outer packaging material 10 via a tab sealant.

[0129] The battery element 52 has a sulfide-based solid electrolyte interposed between the positive electrode and the negative electrode. The metal terminal 53 is a part of the current collector that is exposed to the outside of the outer casing material 10, and is made of metal foil such as copper foil or aluminum foil.

[0130] The all-solid-state battery may be an all-solid-state lithium-ion battery.

[0131] Although a packaging body according to one embodiment has been described above, the packaging body of this disclosure is not limited to the above embodiment. For example, the packaging body does not have to be an all-solid-state battery. Such a packaging body may contain, for example, food that releases hydrogen sulfide as its contents. Examples of such food include meat, eggs, cat food, and fish.

[0132] Furthermore, the packaging bag of the packaging of the present disclosure does not necessarily have to include the laminate according to the above embodiment. In other words, the contents of the packaging of the present disclosure may include the laminate according to the above embodiment. Also, the packaging of the present disclosure may use other laminates of the present disclosure instead of the laminate 10.

[0133] The present disclosure will be described in more detail below based on examples, but the present disclosure is not limited to the following examples.

[0134] [Example 1] <Materials> The following materials were prepared.

[0135] (Base layer (thickness 25 μm)) Polyethylene terephthalate (PET) film (manufactured by Toray Industries, Inc.) was used.

[0136] (First adhesive layer (thickness 5 μm)) A polyurethane adhesive (manufactured by Toyo Ink Co., Ltd.) was used, which was a polyester polyol-based main component combined with a tolylene diisocyanate adduct-type curing agent.

[0137] (Barrier layer (thickness 40 μm)) Annealed and degreased soft aluminum foil (manufactured by Toyo Aluminum Co., Ltd., "8079 material", iron content: 0.7 to 1.3 mass% of 100 mass% of aluminum foil) was used.

[0138] (Adhesive resin layer (thickness 20 μm)) As the adhesive resin, a random polypropylene (PP)-based acid-modified polypropylene resin composition (manufactured by Mitsui Chemicals, Inc.) was used.

[0139] (Sealant layer (thickness 60 μm)) A polypropylene resin (manufactured by Prime Polymer, trade name: F744NP) was prepared as a binder. Zeolite (skeletal structure: type A, silica / alumina ratio: 2, supported cation: sodium ion, pore size: 4 Å) was prepared as a hydrogen sulfide adsorbent. The first composition was obtained by compounding the polypropylene resin with the zeolite and kneading it. The zeolite content was 20% by mass based on the total amount of the first composition. The second composition was obtained by compounding the first composition with the polypropylene resin (manufactured by Prime Polymer, trade name: F744NP) and kneading it. The zeolite content was 5% by mass based on the total amount of the second composition. The second composition was used as a resin composition for forming a sheet (sealant layer).

[0140] <Fabrication of Exterior Material> The barrier layer and the base material layer were laminated by dry lamination using a polyurethane adhesive (first adhesive layer). The lamination of the barrier layer and the base material layer was performed by applying the polyurethane adhesive to a thickness of 5 μm after curing, drying at 80°C for 1 minute, bonding the barrier layer and the base material layer, and aging at 60°C for 72 hours.

[0141] Next, the laminate of the barrier layer and the base layer was set in the unwinding section of an extrusion laminating machine, and an adhesive resin layer (20 μm thick) and a sealant layer (60 μm thick) were laminated in that order by co-extrusion on the barrier layer side surface of the laminate at processing conditions of 270°C and 100 m / min. The adhesive resin layer and sealant layer were prepared in advance by compounding various materials using a twin-screw extruder, and after undergoing water cooling and pelletizing processes, they were used in the above extrusion lamination.

[0142] The laminate obtained in this manner was heat-treated to a maximum temperature of 190°C to produce an exterior material (a laminate of a base layer, a first adhesive layer, a barrier layer, an adhesive resin layer, and a sealant layer).

[0143] <Evaluation of Hydrogen Sulfide Adsorption> The above outer packaging material was cut into 10cm x 10cm pieces to be used as evaluation samples. These samples were placed in a 2L Tedlar bag and the Tedlar bag was sealed. Hydrogen sulfide at a concentration of 20 ppm by mass was placed inside the Tedlar bag. ２ Two liters of S gas were poured into the bag and left at room temperature (25°C) for one week. Afterward, the hydrogen sulfide concentration inside the Tedlar bag was measured, and the amount of hydrogen sulfide adsorbed was calculated. The amount of hydrogen sulfide adsorbed is the percentage (mol%) of hydrogen sulfide adsorbed by the outer packaging material out of the hydrogen sulfide poured into the Tedlar bag. The results are shown in Table 1.

[0144] <Evaluation of Decomposition Inhibition of Polyolefin Resin> The above exterior material was cut into 10 cm x 10 cm pieces to be used as evaluation samples. These samples were placed in an oven and heated to 120°C, and left at that temperature. The heated samples were removed from the oven and the sealant layer of the samples was visually observed. The heating period was 3 days or 1 week. The observation results were evaluated according to the following criteria. The results are shown in Table 1. In the evaluation samples of Comparative Examples 1 to 4, which were heated for 1 week, the sealant layer had crumbled.

[0145] (Criteria) A: No cracks are observed in the sealant layer after both a 3-day and a 1-week heating period. B: No cracks are observed in the sealant layer after a 3-day heating period, but cracks are observed after a 1-week heating period. C: Cracks are observed in the sealant layer after both a 3-day and a 1-week heating period.

[0146] [Example 2] An exterior material was prepared in the same manner as in Example 1, except that the following material was used as the zeolite, and its hydrogen sulfide adsorption and decomposition properties of polyolefin resin were evaluated. • Zeolite (skeletal structure: Type A, silica / alumina ratio: 2, supported cations: calcium ions, pore size: 5 Å)

[0147] [Example 3] An exterior material was prepared in the same manner as in Example 1, except that the following material was used as the zeolite, and its hydrogen sulfide adsorption and decomposition properties of polyolefin resin were evaluated. • Zeolite (skeletal structure: Type A, silica / alumina ratio: 2, supported cations: zinc ions and silver ions, pore size: 5 Å)

[0148] [Example 4] An exterior material was prepared in the same manner as in Example 1, except that the following material was used as the zeolite, and its hydrogen sulfide adsorption and decomposition properties of polyolefin resin were evaluated. • Zeolite (skeletal structure: ferrielite, silica / alumina ratio: 18, supported cations: potassium ions, pore size: 5 Å)

[0149] [Comparative Example 1] An exterior material was prepared in the same manner as in Example 1, except that the following material was used as the zeolite, and its hydrogen sulfide adsorption properties and decomposition properties of polyolefin resin were evaluated. • Zeolite (skeletal structure: X-type, silica / alumina ratio: 2.5, supported cations: sodium ions, pore size: 9 Å)

[0150] [Comparative Example 2] An exterior material was prepared in the same manner as in Example 1, except that the following material was used as the zeolite, and its hydrogen sulfide adsorption and decomposition properties of polyolefin resin were evaluated. • Zeolite (skeletal structure: Y-type, silica / alumina ratio: 5.5, supported cations: zinc ions, pore size: 9 Å)

[0151] [Comparative Example 3] An exterior material was prepared in the same manner as in Example 1, except that the following material was used as the zeolite, and its hydrogen sulfide adsorption and decomposition properties of polyolefin resin were evaluated. • Zeolite (skeletal structure: Y-type, silica / alumina ratio: 5.5, supported cations: copper ions, pore size: 9 Å)

[0152] [Comparative Example 4] An exterior material was prepared in the same manner as in Example 1, except that the following material was used as the zeolite, and its hydrogen sulfide adsorption and decomposition properties of the polyolefin resin were evaluated. • Zeolite (skeletal structure: ZSM-5, silica / alumina ratio: 75, supported cations: sodium ions, pore size: 6 Å)

[0153] [Comparative Example 5] Except for using a polypropylene resin (manufactured by Prime Polymer, trade name: F744NP) as is as the resin composition for sheet formation, an exterior material was prepared in the same manner as in Example 1, and the hydrogen sulfide adsorption properties and the decomposition properties of the polyolefin resin were evaluated.

[0154]

[0155] 1...sheet, 10, 20, 25, 30, 35...laminated body, 11...base layer, 13...barrier layer, 40...packaging bag, 52...battery element.

Claims

1. A sheet comprising a polyolefin resin as a binder and zeolite as a hydrogen sulfide adsorbent, wherein the pore size of the zeolite is 3.5 Å to 5.5 Å.

2. The sheet according to claim 1, wherein the skeletal structure of the zeolite is type A.

3. The sheet according to claim 1, wherein the silica / alumina ratio of the zeolite is 2.5 or less.

4. The sheet according to claim 1, wherein the cation supported on the zeolite is at least one cation selected from the group consisting of zinc ions, silver ions, copper ions, calcium ions, potassium ions, sodium ions, manganese ions, cobalt ions, nickel ions, and ammonium ions.

5. The sheet according to claim 1, wherein the polyolefin resin includes a polypropylene resin.

6. A laminate comprising a base layer and a sheet according to any one of claims 1 to 5.

7. The laminate according to claim 6, further comprising a barrier layer between the base material layer and the sheet.

8. The laminate according to claim 7, wherein the barrier layer comprises aluminum foil containing iron, and the iron content is 0.1 to 9.0% by mass based on the total amount of aluminum foil.

9. The laminate according to claim 7, further comprising a first corrosion-preventive treatment layer between the base material layer and the barrier layer, and a second corrosion-preventive treatment layer between the barrier layer and the sheet.

10. The laminate according to claim 8, comprising the base layer, the first adhesive layer, the barrier layer, the adhesive resin layer, and the sheet, in this order, wherein the pore size of the zeolite is 4.5 Å to 5.5 Å, the skeletal structure of the zeolite is type A, the silica / alumina ratio of the zeolite is 1.5 to 2.5, the cations supported on the zeolite include zinc ions and silver ions, the polyolefin resin includes a polypropylene resin, and the iron content is 0.5 to 2.0% by mass based on the total amount of the aluminum foil.

11. The laminate according to claim 6, for use in an all-solid-state battery.

12. A packaging bag comprising the laminate described in claim 6.

13. A packaging body comprising a packaging bag and contents contained within the packaging bag, wherein the packaging bag or the contents include the sheet described in any one of claims 1 to 5.

14. The packaging according to claim 13, wherein the contents include a battery element having a sulfide-based solid electrolyte.

15. The packaging according to claim 13, wherein the contents include a food that releases hydrogen sulfide.

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