Packaging material for all-solid-state lithium-ion battery, and package

Abstract

To provide a water-absorbing packaging material and a packaging body for a sulfide-based inorganic solid electrolyte type all-solid lithium ion battery which is excellent in manufacturing suitability, and suppress infiltration of moisture into a packaged sulfide-based inorganic solid-state electrolyte type all-solid lithium ion battery to suppress occurrence of a sulfur-based gas from the solid electrolyte regardless of a simple layer structure.SOLUTION: A water-absorbing packaging material 1 includes at least a base material layer 2 formed of a base film, a gas barrier layer 4 formed of a gas barrier film, and a sealant layer 5 formed of a water-absorbing sealant film. The water-absorbing sealant film has an inorganic-based water absorber 7 and a heat-sealing resin. The inorganic-based water absorber has one or more components selected from calcium oxide, anhydrous magnesium sulfate, magnesium oxide, calcium chloride, zeolite, aluminum oxide, silica gel, alumina gel, and burnt alum. The content of the inorganic-based water absorber in the layer having the inorganic-based water absorber is 0.5 to 50 mass%.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a packaging material having the ability to absorb gaseous water and / or liquid (hereinafter referred to as water absorbency) for packaging a sulfide-based inorganic solid electrolyte type all-solid-state lithium ion battery, and a package obtained by packaging a sulfide-based inorganic solid electrolyte type all-solid-state lithium ion battery with the packaging material. The packaging material for a sulfide-based inorganic solid electrolyte type all-solid-state lithium ion battery of the present invention can be applied to sulfide-based inorganic solid electrolyte type all-solid-state lithium ion battery products in various fields, and is particularly suitable for use as a packaging material for packaging a large-capacity all-solid-state lithium ion battery, such as for a home energy storage system or for use as a power source for an electric motor in an automobile.

Background Art

[0002] Conventionally, as a packaging material for packaging a lithium ion battery, improvement in sealing performance, water vapor barrier performance for preventing intrusion of water vapor from the outside, chemical resistance for preventing leakage of the electrolyte, heat resistance for preventing melting when the lithium ion battery generates heat and leakage of the electrolyte, etc. have been demanded (Patent Document 1). In particular, in the case of a sulfide-based inorganic solid electrolyte type all-solid-state lithium ion battery, since the solid electrolyte reacts with moisture to generate a sulfur-based gas, it is necessary to isolate the solid electrolyte from moisture. However, in recent years, assuming that a lithium ion battery package is used for a long period of about 20 years, for example, in in-vehicle or home applications, in the case of an all-solid-state lithium ion battery, sulfur-based gases generated by decomposition of the electrolyte during charging accumulate, and there is a growing concern that the lithium ion battery package may expand or burst. As a method for removing various outgases, a resin film having a flavonoid-based compound has been proposed (Patent Document 2). However, since the flavonoid-based compound is inferior in heat resistance, there are limitations on the heating conditions in the manufacturing process of the resin film, and the effect of removing various outgases is insufficient. In addition, as resin films for removing various outgases, resin films containing zeolite, metal silicate containing copper, and an antifogging agent composed of glycerin esters have been proposed (Patent Document 3). However, they mainly focus on removing moisture and ethylene gas generated from the contents, and the effect of preventing moisture intrusion and removing various outgases is insufficient.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present invention solves the above problems, has excellent manufacturing suitability, and has a simple layer structure. While suppressing the intrusion of moisture into a packaged sulfide-based inorganic solid electrolyte type all-solid-state lithium-ion battery and suppressing the generation of sulfur-based gases from the solid electrolyte, it provides a water-absorbing packaging material for a sulfide-based inorganic solid electrolyte type all-solid-state lithium-ion battery, and a sulfide-based inorganic solid electrolyte type all-solid-state lithium-ion battery package obtained by packaging a sulfide-based inorganic solid electrolyte type all-solid-state lithium-ion battery with the water-absorbing packaging material. This is the object.

Means for Solving the Problems

[0005] As a result of various studies, the present inventors have found that a water-absorbing packaging material for a sulfide-based inorganic solid electrolyte type all-solid-state lithium-ion battery containing a thermoplastic resin and a specific inorganic water absorbent achieves the above object.

[0006] That is, the present invention is characterized by the following points. 1. A water-absorbing packaging material for a sulfide-based inorganic solid electrolyte type all-solid-state lithium-ion battery that absorbs gaseous water and / or liquid water, The water-absorbing packaging material includes at least a base material layer made of a base film, a gas barrier layer made of a gas barrier film, and a sealant layer made of a water-absorbing sealant film. The water-absorbing sealant film contains an inorganic water absorbent and a heat-sealable resin. The inorganic water absorbent contains one or more selected from the group consisting of calcium oxide, magnesium sulfate anhydride, magnesium oxide, calcium chloride, zeolite, aluminum oxide, silica gel, alumina gel, and burnt alum. The content of the inorganic water absorbent in the layer containing the inorganic water absorbent is 0.5% by mass or more and 50% by mass or less. Water-absorbing packaging material. 2. The inorganic water absorbent contains calcium oxide and / or magnesium sulfate anhydride. The water-absorbing packaging material according to 1 above. 3. The base film contains a polyamide resin and / or a polyester resin. The water-absorbing packaging material according to 1 or 2 above. 4. The gas barrier film is an aluminum foil. The water-absorbing packaging material according to any one of 1 to 3 above. 5. An all-solid-state lithium-ion battery package of a sulfide-based inorganic solid electrolyte type produced from the water-absorbing packaging material according to any one of 1 to 4 above.

Advantages of the Invention

[0007] The water-absorbing packaging material for an all-solid-state lithium-ion battery of the present invention solves the above problems, is excellent in manufacturing suitability, has an excellent water absorption property and an excellent heat-sealing property while having a simple layer structure, suppresses the absorption of water by the all-solid-state lithium-ion battery and the generation of sulfur-based gas, and can achieve the effect of being less likely to cause peeling or swelling due to sulfur-based gas.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

[0009] In each figure, for the sake of clarity, the size and ratio of the members may be changed or exaggerated. Also, for the sake of visibility, parts that are not necessary for explanation and repeated reference numerals may be omitted. Also, although omitted in each figure, an adhesive layer can be provided between each layer. Furthermore, if necessary, in order to strengthen the adhesive strength (adhesion strength) between each layer, physical surface treatments such as corona discharge treatment, ozone treatment, plasma treatment, glow discharge treatment, sandblasting treatment, etc., and chemical surface treatments such as oxidation treatment using chemical agents can be performed in advance.

Embodiments for Carrying Out the Invention

[0010] The water-absorbing packaging material for the sulfide-based inorganic solid electrolyte type all-solid-state lithium-ion battery of the present invention will be further described in detail below. Although described with specific examples, the present invention is not limited thereto.

[0011] (Gas to be Absorbed) In the present invention, the gas to be absorbed is gaseous water and / or liquid water. The solid electrolyte of a sulfide-based inorganic solid electrolyte type all-solid-state lithium-ion battery generates sulfur-based gas by absorbing water, so the generation of sulfur-based gas can be suppressed by suppressing water absorption. Specific examples of sulfur-based gases include hydrogen sulfide, dimethyl sulfide, methyl mercaptan, sulfur oxides represented by SO x and the like, and particularly a large amount of hydrogen sulfide.

[0012] ≪All-solid-state lithium-ion battery≫ A typical configuration of a lithium-ion battery includes a positive electrode made of an oxide containing lithium, a negative electrode containing a carbon material as the negative electrode, a separator, and an electrolyte. Here, the properties of the electrolyte are of a liquid type and a solid type, and the all-solid-state lithium-ion battery refers to the type where the above electrolyte is solid. Also, a general lithium-ion battery is a secondary battery capable of charging and discharging by the movement of lithium ions between the positive electrode and the negative electrode. In the present invention as well, the lithium-ion battery refers to this secondary battery. As solid electrolytes, there are oxide-based and sulfide-based. The sulfide-based is preferred because it enables higher output. The above sulfide-based solid electrolyte is a compound that easily reacts with moisture to generate sulfur-based gas. When the all-solid-state lithium-ion battery absorbs moisture, decomposition gas (sulfur-based gas) of the sulfide-based solid electrolyte containing sulfur-based gas is generated. In all-solid-state lithium-ion batteries for in-vehicle use and household power storage system applications assumed to be used for about 20 years or more, the cumulative amount of sulfur-based gas generated is very large. Therefore, for the pouch packaging the all-solid-state lithium-ion battery, there are concerns about expansion, bag breakage due to sulfur-based gas containing sulfur-based gas, and corrosion of the metal foil layer such as aluminum foil, and countermeasures against these are required.

[0013] ≪Water-absorbing packaging material≫ The water-absorbing packaging material for the all-solid-state lithium-ion battery of the present invention is particularly suitable for the all-solid-state lithium-ion battery of the sulfide-based inorganic solid electrolyte type that absorbs water and generates sulfur-based gas. The water-absorbing packaging material for all-solid-state lithium-ion batteries of the present invention can suppress the generation of sulfur-based gases from sulfide-based inorganic solid electrolyte type all-solid-state lithium-ion batteries by having excellent water absorption.

[0014] The water-absorbing packaging material for all-solid-state lithium-ion batteries of the present invention includes at least a base material layer made of a base film, a gas barrier layer made of a gas barrier film, and a sealant layer made of a water-absorbing sealant film. The water-absorbing sealant film contains an inorganic water absorbent and a heat-sealable resin. The gas barrier layer is preferably laminated between the base material layer and the sulfur-based gas absorption layer. The sulfur-based gas absorption packaging material can further include an intermediate layer having various functions, if necessary. In addition, each layer constituting the sulfur-based gas absorption packaging material may be laminated via an adhesive layer. It is also acceptable. The sulfur-based gas absorption packaging material is a packaging material produced from a sulfur-based gas absorption laminate including the above base material layer, gas barrier layer, and sealant layer. One surface of the sulfur-based gas absorption packaging material for all-solid-state lithium-ion batteries preferably has heat sealability. Therefore, it is preferable that the surface having heat sealability of the water-absorbing film constitutes one side surface of the sulfur-based gas absorption packaging material. The water-absorbing packaging material can further contain various plastic compounding agents and additives, etc. for the purpose of improving and modifying, for example, processability, heat resistance, weather resistance, mechanical properties, dimensional stability, antioxidant properties, slipperiness, releasability, flame retardancy, antifungal properties, electrical properties, strength, etc. The content can be arbitrarily contained from a very small amount to several tens of %, depending on the purpose. In the above, general additives can include, for example, antiblocking agents, lubricants, crosslinking agents, antioxidants, ultraviolet absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, pigments, modifying resins, etc.

[0015] <Sealant layer> By including an inorganic absorbent, the sealing layer can impart water absorbency to the water-absorbing packaging material, and by containing a heat-sealable resin, heat sealability can be imparted to the water-absorbing packaging material. The sealing layer is preferably a layer made of a water-absorbing seal film. The water-absorbing seal film is a water-absorbing film having heat sealability, and can be produced by incorporating a heat-sealable resin into the water-absorbing film or laminating a layer containing a heat-sealable resin on the water-absorbing film. By including an inorganic absorbent, the sealing layer can impart water absorbency to the water-absorbing packaging material, and by containing a heat-sealable resin, heat sealability can be imparted to the water-absorbing packaging material. The outer surface of the sealing layer preferably has heat sealability by containing a heat-sealable resin. In addition, the sealing layer may further include a layer derived from other than the water-absorbing seal film, if necessary. For example, a support layer for reinforcing the supportability can be further included. The sealing layer may be a single-layer structure or a multi-layer structure of two or more layers having the same or different compositions. For example, it may be a single layer containing an inorganic absorbent and a heat-sealable resin, or there may be two layers, a water-absorbing layer containing an inorganic absorbent and a heat-sealing layer containing a heat-sealable resin without containing an inorganic absorbent. Further, the water-absorbing layer may be a multi-layer having different types and contents of inorganic absorbents. Here, the water-absorbing layer may contain a heat-sealable resin. Here, the sulfur-based gas absorption layer may contain a heat-sealable resin. There is no particular limitation on the thickness of the sealing layer, but it is preferably 10 μm or more and 100 μm or less. If it is thinner than the above range, the rigidity is too low, it is easily torn, and it is difficult to exhibit a sufficient water absorption effect. If it is thicker than the above range, the rigidity is too strong, and the usability as a packaging material or packaging material tends to deteriorate.

[0016] <<Water-absorbing film>> The water-absorbing film in the present invention is a water-absorbing film that absorbs moisture in gas and / or liquid, and has a water-absorbing layer.

[0017] The water-absorbing layer contains at least a thermoplastic resin and a specific water absorbent. The water-absorbing film exhibits water absorption by containing a water absorbent, and the thermoplastic resin disperses the water absorbent and is contained as a resin component constituting the water-absorbing film. And as the water absorbent, an inorganic water absorbent can be contained. And also, if necessary, the water-absorbing film can further contain a heat-sealable resin. By further containing a heat-sealable resin, the water-absorbing film can exhibit heat-sealability.

[0018] The water-absorbing film may be of a single-layer structure or may be composed of two or more layers with the same or different compositions. For example, there may be two layers, a layer containing an inorganic water absorbent (water-absorbing layer) and a layer not containing an inorganic water absorbent. Also, there may be layers with different contents of the inorganic water absorbent. And the heat-sealable resin may be contained in the water-absorbing layer or may be contained in a layer not containing a water absorbent to form a heat-sealing layer. Furthermore, the water-absorbing film can also have a support layer for reinforcing the supportability if necessary. And each layer constituting the water-absorbing film may be laminated via an adhesive layer.

[0019] The content of the inorganic water absorbent in the layer containing the inorganic water absorbent is preferably 0.1% by mass or more and 50% by mass or less, and more preferably 2% by mass or more and 50% by mass or less. If it is less than the above range, there is a risk that sufficient water absorption cannot be exhibited. If it is more than the above range, the water absorption is not particularly improved, and there is a risk that the interlayer adhesion and heat-sealability decrease, or the rigidity becomes too strong.

[0020] The water-absorbing film can contain various plastic compounding agents, additives, etc. for the purpose of improving and modifying, for example, processability, heat resistance, weather resistance, mechanical properties, dimensional stability, antioxidant properties, slipperiness, releasability, flame retardancy, antibacterial properties, electrical properties, strength, etc. The content can be arbitrarily contained from a very small amount to several tens of %, depending on the purpose. In the above, as general additives, for example, antiblocking agents, lubricants, crosslinking agents, antioxidants, ultraviolet absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, pigments, resins for modification, etc. can be contained.

[0021] There is no particular limitation on the thickness of the water-absorbing film, but it is preferably 10 μm or more and 100 μm or less. If it is thinner than the above range, the rigidity is too low, it is easy to break, and it is difficult to exhibit a sufficient water absorption effect. If it is thicker than the above range, the rigidity is too strong, and it is easy to deteriorate the usability as a packaging material or packaging material.

[0022] [Water-absorbing layer] The water-absorbing layer is a layer containing a water absorbent, and also contains a thermoplastic resin for dispersing the water absorbent. Further, the water-absorbing layer may contain a heat-sealing resin, and if it has sufficient heat-sealing properties, it can also serve as a sealant layer at the same time. There is no particular limitation on the thickness of the water-absorbing layer, but it is preferably 5 μm or more and 50 μm or less. If it is thinner than the above range, it is difficult to exhibit a sufficient water absorption effect. Even if it is thicker than the above range, the water absorption effect does not improve so much, and the rigidity of the film contained becomes too strong, which easily deteriorates the usability as a sealant film or packaging material.

[0023] [Water absorbent]< (Inorganic water absorbent) In order to obtain excellent long-term stability in a low humidity state inside the package, the inorganic water absorbent preferably contains one or more selected from the group consisting of calcium oxide, magnesium sulfate anhydride, magnesium oxide, calcium chloride, zeolite, synthetic zeolite, aluminum oxide, silica gel, alumina gel, silica-alumina gel, and calcined gypsum. In general, among inorganic water absorbents, inorganic chemical water absorbents are more effective than inorganic physical water absorbents. It has a high water absorption effect, and the content can be reduced, making it easy to achieve sufficient water absorption and heat sealability in a single layer. Among inorganic chemical water absorbents, calcium oxide and anhydrous magnesium sulfate are particularly preferred because they release less moisture, have high stability over time in the low humidity state inside the package, and have an absolute dry effect. The bone-drying effect refers to the effect of absorbing water until the relative humidity reaches approximately 0%, and the moisture-regulating effect refers to the effect of absorbing water when the humidity is high and releasing moisture when the humidity is low, thereby keeping the humidity constant.

[0024] The inorganic water absorbing agent contained in the water absorbing layer is preferably contained via a master batch in which a powdered inorganic water absorbing agent is melt-blended with a thermoplastic resin. Specifically, it is preferable to melt-blend a powdered inorganic water absorbent into a thermoplastic resin at a relatively high concentration to prepare a master batch, and then dry-blend the master batch with other components to achieve a desired concentration in the sulfur-based gas absorbing layer. The thermoplastic resin to be melt-blended may be one type or two or more types. The content of the inorganic water absorbing agent in the master batch is preferably 20% by mass or more and 90% by mass or less, and more preferably 30% by mass or more and 70% by mass or less. Within the above range, it is easy to include a necessary and sufficient amount of the inorganic water absorbing agent in the water absorption layer in a dispersed state.

[0025] [Thermoplastic resin] There are no particular limitations on the thermoplastic resin contained together with the sulfur-based gas absorbent, so long as it has excellent dispersibility for the inorganic water absorbing agent and can withstand use as a packaging material. The thermoplastic resin may also contain a heat-sealable resin. The thermoplastic resin preferably contains a polyolefin resin. Specific examples of polyolefin resins include low-density polyethylene (LDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), linear (linear) low-density polyethylene (LLDPE), ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-methyl methacrylate copolymer, ethylene-propylene copolymer, etc., and mixtures of these resins. Among the above, polyethylene-based resins are preferred. Among polyethylene-based resins, LDPE, LLDPE, general-purpose PE, PE-based copolymers, etc. are more preferred, and LLDPE is even more preferred.

[0026] [Heat-sealable resin] The heat-sealable resin can be any resin that can be melted and fused by heat without particular limitation, and known resins can be used. Specific examples of heat-sealable resins include polyethylene, low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear (linear) low-density polyethylene, metallocene polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ionomer resin, ethylene-(meth)ethyl acrylate copolymer, ethylene-(meth)acrylic acid copolymer, ethylene-propylene copolymer, methylpentene polymer, polyolefin resins such as polyethylene or polypropylene modified with unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic anhydride, fumaric acid, etc., ethylene-(meth)acrylate-unsaturated carboxylic acid terpolymer resins, cyclic polyolefin resins, cyclic olefin copolymers, polyethylene terephthalate (PET), polyacrylonitrile (PAN), etc. Among these, polyolefin resins are preferred, polyethylene-based resins are more preferred, and low-density polyethylene and linear (linear) low-density polyethylene are even more preferred.

[0027] [Heat-sealing layer] The heat-sealing layer contains a heat-sealing resin and is a layer having sufficient heat-sealing properties. It may or may not contain a sulfur-based gas absorbent.

[0028] [Support layer] The support layer is a layer included as needed. For example, it is included to supplement the rigidity of the water-absorbing film and can also have the effect of preventing blocking when the water-absorbing film is wound or stacked. As the resin contained in the support layer, LDPE or LLDPE is preferable. Also, it may contain a heat-sealing resin. There is no particular limitation on the thickness of the support layer, but it is preferably 1 μm or more and 50 μm or less. If it is thinner than the above range, it is difficult to exhibit the effect of reinforcing the rigidity. If it is thicker than the above range, the rigidity is too strong and the usability as a packaging material or packaging material tends to deteriorate.

[0029] [Adhesive layer] There is no particular limitation on the adhesive used for the adhesive layer, and a dry lamination adhesive, an EC (extrusion coat) adhesive, a non-solvent lamination adhesive, any anchor coating agent, etc. can be used. Also, the adhesive may be any of thermosetting type, ultraviolet curable type, electron beam curable type, etc., and may be in any form such as aqueous type, solution type, emulsion type, dispersion type, etc. Further, its properties may be in any form such as film / sheet form, powder form, solid form, etc. Moreover, the adhesion mechanism may be in any form such as chemical reaction type, solvent evaporation type, hot melt type, hot press type, etc.

[0030] Examples of components for forming such an adhesive layer include polyvinyl acetate-based adhesives such as polyvinyl acetate and vinyl acetate-ethylene copolymers, polyacrylic acid-based adhesives composed of copolymers of polyacrylic acid with polystyrene, polyester, polyvinyl acetate, etc., cyanoacrylate-based adhesives, ethylene copolymer-based adhesives composed of copolymers of ethylene with monomers such as vinyl acetate, ethyl acrylate, acrylic acid, methacrylic acid, etc., cellulose-based adhesives, polyurethane-based adhesives, polyester-based adhesives, polyamide-based adhesives, polyimide-based adhesives, polyolefin-based adhesives such as LDPE, amino resin-based adhesives composed of urea resin or melamine resin, etc., phenol resin-based adhesives, epoxy-based adhesives, reactive (meth)acrylic-based adhesives, elastomer-based adhesives composed of chloroprene rubber, nitrile rubber, styrene-butadiene rubber, etc., silicone-based adhesives, inorganic-based adhesives composed of alkali metal silicate, low melting point glass, etc.

[0031] ≪Water-absorbing sealant film≫ The water-absorbing sealant film is a sealant film made from a water-absorbing film and has water absorbency similar to that of the water-absorbing film and excellent heat sealability. When the water-absorbing film has sufficient heat sealability and supportability, the water-absorbing film can be used directly as the water-absorbing sealant film. If necessary, a support layer can be further laminated, a heat-sealable resin can be incorporated, or a layer containing a heat-sealable resin can be laminated to produce a water-absorbing sealant film.

[0032] The water-absorbing sealant film may have a single-layer structure or a multi-layer structure of two or more layers. In the case of a multi-layer structure, a support layer or a heat-seal layer can be laminated on the layer derived from the water-absorbing film to produce a water-absorbing sealant film. And if necessary, various functional layers can be further laminated to produce a water-absorbing sealant film. Here, each layer constituting the water-absorbing sealant film may be laminated via an adhesive layer. One or both surfaces of the water-absorbing sealant film preferably have heat-sealability. To achieve this, for example, a heat-seal layer may be laminated on one or both surfaces of the water-absorbing sealant film. By having heat-sealability on both surfaces of the water-absorbing sealant film, a water-absorbing laminate excellent in interlayer adhesion and heat-sealability inside the water-absorbing laminate can be produced.

[0033] There is no particular limitation on the thickness of the water-absorbing sealant film, but it is preferably 10 μm or more and 100 μm or less. If it is thinner than the above range, the rigidity is too low, it is easy to break, and it is difficult to exhibit a sufficient water absorption effect. If it is thicker than the above range, the rigidity is too strong, and it is likely to be inconvenient to use as a packaging material or packaging material.

[0034] <<Production method of water-absorbing film and water-absorbing sealant film> The production method shown below is an example and does not limit the present invention. The film formation and lamination methods of the water-absorbing film or water-absorbing sealant film and each layer constituting them are not particularly limited, and known or conventional film formation methods and lamination methods can be applied. The production of the water-absorbing film or water-absorbing sealant film can be carried out by known film formation methods and / or lamination methods such as the (co)extrusion method, cast molding method, T-die method, cutting method, inflation method, etc. When the water-absorbing film or water-absorbing sealant film is composed of two or more layers, for example, the films constituting each layer prepared in advance may be laminated via an adhesive layer, or a molten resin composition may be laminated on the layer prepared in advance by (co)extrusion, or multiple layers may be laminated by melt pressure bonding while simultaneously producing them, or one or two or more resins may be applied and dried on another layer for coating. For example, an example of producing a water-absorbing sealant film by laminating a heat-seal layer on a water-absorbing film can be described.

[0035] The water-absorbing layer and the heat-sealing layer can also be laminated on other layers by extrusion or co-extrusion using the extrusion coating method, or laminated via an adhesive layer after film formation by the inflation method or the casting method. Even in the case of the extrusion coating method, lamination may be performed via an adhesive layer if necessary. Alternatively, a pre-formed film for the water-absorbing layer or a film for the heat-sealing layer may be laminated and adhered via an adhesive layer laminated by the extrusion coating method, the dry lamination method, the non-solvent lamination method, or the like. And an aging treatment may be performed as necessary.

[0036] For example, when laminating the water-absorbing layer or the heat-sealing layer by the extrusion coating method, first, the resin composition forming the layer is heated and melted, expanded and stretched in the necessary width direction by a T-die, and (co-)extruded in a curtain shape. The molten resin is allowed to flow down onto the surface to be laminated, and the layer is formed, laminated, and adhered to the surface to be laminated simultaneously by sandwiching it between a rubber roll and a cooled metal roll. The melt flow rate (MFR) of the resin component contained in each layer when laminating by the extrusion coating method is preferably 0.2 to 50 g / 10 min, more preferably 0.5 to 30 g / 10 min. If the MFR is smaller or larger than the above range, the processability is likely to be poor. In this specification, the MFR is a value measured by a method conforming to JIS K7210.

[0037] The melt flow rate (MFR) of the resin component contained in each layer when using the inflation method is preferably 0.2 to 10 g / 10 min, more preferably 0.2 to 9.5 g / 10 min. If the MFR is smaller or larger than the above range, the processability is likely to be poor.

[0038] In addition, between each layer constituting the water-absorbing film or the water-absorbing sealant film, in order to improve the adhesiveness, a desired surface treatment can be performed in advance on the surface of each layer as necessary. For example, pretreatment such as corona discharge treatment, ozone treatment, low-temperature plasma treatment using oxygen gas or nitrogen gas, glow discharge treatment, oxidation treatment using chemicals, etc. can be arbitrarily performed to form and provide a corona treatment layer, ozone treatment layer, plasma treatment layer, oxidation treatment layer, etc. Alternatively, various coating agent layers such as a primer coating agent layer, an undercoat agent layer, an anchor coating agent layer, an adhesive layer, a vapor deposition anchor coating agent layer, etc. can be arbitrarily formed on the surface to form a surface treatment layer. For the above various coating agent layers, for example, resin compositions using polyester resins, polyamide resins, polyurethane resins, epoxy resins, phenolic resins, (meth)acrylic resins, polyvinyl acetate resins, polyolefin resins such as polyethylene or polypropylene or copolymers or modified resins thereof, cellulose resins, etc. as the main component of the vehicle can be used.

[0039] Each layer constituting the water-absorbing film or water-absorbing sealant film can be further uniaxially or biaxially stretched by a conventionally known method using, for example, a tenter method or a tubular method as necessary.

[0040] ≪Water-absorbing laminate≫ The water-absorbing laminate of the present invention is a laminate obtained by laminating the water-absorbing film or water-absorbing sealant film of the present invention with, for example, a base material layer or a gas barrier layer, and has water absorption similar to that of the water-absorbing film. The water-absorbing laminate can further include an intermediate layer having various functions as necessary. One surface of the water-absorbing laminate is preferably a heat-sealing layer because the water-absorbing laminate has heat-sealing properties. The gas barrier layer is preferably laminated between the base material layer and the water-absorbing layer. Also, each layer constituting the water-absorbing laminate may be laminated via an adhesive layer. And an aging treatment may be performed as necessary.

[0041] The water-absorbent laminate or each layer constituting the water-absorbent laminate can contain various plastic compounding agents, additives, etc. for the purpose of improving or modifying, for example, processability, heat resistance, weather resistance, mechanical properties, dimensional stability, antioxidant properties, slipperiness, releasability, flame retardancy, antifungal properties, electrical properties, strength, etc. The content can be arbitrarily contained from a very small amount to several tens of %, depending on the purpose. In the above, as general additives, for example, antiblocking agents, lubricants, crosslinking agents, antioxidants, ultraviolet absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, pigments, modifying resins, etc. can be contained.

[0042] <Base material layer> As the material of the base material layer, a generally known and publicly used base material film having excellent properties in terms of mechanical, physical, chemical, and others, particularly having strength, toughness, and heat resistance can be used. As the base material film, various resin films can be used, and furthermore, various paper base materials can be used, and a combination of a resin film and a paper base material can also be used. The base material layer may be composed of one layer or may be composed of two or more layers laminated by any lamination means of the same or different compositions. The thickness of the base material layer can be appropriately set by those skilled in the art, but for the purpose of imparting appropriate strength and firmness to the laminate, the thickness of the base material layer is preferably 5 μm to 100 μm, more preferably 10 μm to 50 μm, and even more preferably 5 to 25 μm.

[0043] Specific resin films include resin films made of tough thermoplastic resins such as polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate, polyolefin resins such as polypropylene, polyamide resins such as nylon, polyaramid resins, polycarbonate resins, polyacetal resins, fluorine-based resins, and others. And the above resin films can be used regardless of whether they are unstretched films or stretched films stretched in one or two directions. Among these, a resin film containing a polyester-based resin and / or a polyamide-based resin is preferable, and a biaxially stretched PET film or a biaxially stretched nylon film is more preferably used.

[0044] The paper substrate can impart formability, flex resistance, rigidity, etc. For example, sized or unsized paper substrates for paper layers with strong sizing properties, or paper substrates such as pure white roll paper, kraft paper, cardboard, processed paper, milk carton paper, etc. can be used. As the paper substrate, those with a basis weight of about 30 g / m 2 ~600 g / m 2 are preferable, and those with a basis weight of about 50 g / m 2 ~450 g / m 2 are more preferable.

[0045] For the resin film used in the base material layer, if necessary, for the purpose of improving and modifying processability, heat resistance, weather resistance, mechanical properties, dimensional stability, antioxidant properties, slipperiness, releasability, flame retardancy, antifungal properties, electrical properties, strength, etc., plastic compounding agents and additives such as lubricants, crosslinking agents, antioxidants, ultraviolet absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, pigments, etc. can be added, and the addition amount can be arbitrarily added according to the purpose within the range that does not adversely affect other performances. Also, a printing layer can be provided on one side or both sides of the base material layer.

[0046] [Printing layer] The printing layer is for decoration, display of contents, display of expiration date, display of manufacturer, seller, etc., and other displays and for imparting aesthetic sense. For example, it visually shows design patterns such as characters, numbers, figures, symbols, patterns, etc., and can form a desired design pattern. The printing layer is preferably formed on one side or both sides of the base material layer by a printing method such as gravure printing or flexographic printing. And the printing layer can be provided on the entire surface of the printed surface or on a part of it. If the printing layer is formed inside the laminate, the adhesion of the printing layer can be improved, and ink rubbing, peeling, etc. of the printing layer due to external impact and friction can be suppressed. When the printing layer is inside the laminate, in order to make the printing layer visible, the layer outside the printing layer at the time of forming the package is preferably transparent.

[0047] [Gas barrier layer] The barrier layer is a layer that suppresses the permeation of gases. When producing a sulfur-based gas absorption package, it suppresses the intrusion of oxygen and water vapor from outside the sulfur-based gas absorption package into the content storage part inside the package, and suppresses the diffusion of gas components generated from the contents to the outside of the barrier layer. In addition, the permeation of the gas to be absorbed in the present invention can be similarly suppressed. Various barrier materials can be used for the gas barrier layer. Further, it may be a barrier material having not only light-shielding properties against sunlight etc. and fragrance retention properties against contents but also against oxygen and water vapor. Further, a barrier material having gas barrier properties against water vapor etc., light-shielding properties against sunlight etc., and fragrance retention properties against contents may be used in combination.

[0048] As the above-described barrier material, it is preferable to use a gas barrier film. Specifically, for example, one or more selected from the group consisting of a metal foil, a resin film having an inorganic vapor deposition layer, a resin coating film or a resin film made of an oxygen barrier resin can be used. In particular, any of a resin film having a metal vapor deposition layer, a resin film having a vapor deposition layer of a metal oxide, a resin coating film or a resin film made of a barrier resin is preferable because it has excellent barrier properties such as oxygen gas, water vapor, light-shielding properties, and fragrance retention properties, and has the advantage of being environmentally friendly on the disposal surface of the container.

[0049] Specific examples of the metal foil include aluminum foil. The thickness of the aluminum foil is preferably 5 μm to 50 μm. Examples of the inorganic compound for forming the inorganic vapor deposition layer include metals, metal oxides, metal nitrides, metal carbides, and the like. Specific examples of the metal elements constituting the above inorganic compound include, for example, aluminum (Al), silicon (Si), magnesium (Mg), calcium (Ca), potassium (K), tin (Sn), sodium (Na), boron (B), titanium (Ti), lead (Pb), zirconium (Zr), yttrium (Y), zinc (Zn), vanadium (V), barium (Ba), chromium (Cr), and the like.

[0050] In addition to these, composite inorganic compounds such as indium tin oxide (ITO) and SiO X C Y films produced by chemical vapor deposition and the like can also be mentioned.

[0051] As the inorganic material for vapor deposition used in the resin film having a vapor deposition layer, silicon oxide and aluminum oxide are preferable. The notation of the average composition of the inorganic compound is, for example, SiO x , AlO x , SiO x C y and so on, such as MO x , MO x C y (However, in the formula, M represents a metal element, and the values of x and y vary depending on the metal element.) It is represented by. In the case of a metal oxide, the range of the value of X is, for example, for silicon, 0 to 2, for aluminum, 0 to 1.5, for magnesium, 0 to 1, for calcium, 0 to 1, for potassium, 0 to 0.5, for tin, 0 to 2, for sodium, 0 to 0.5, for boron, 0 to 1.5, for titanium, 0 to 2, for lead, 0 to 1, for zirconium 0 to 2, and for yttrium, values in the range of 0 to 1.5 can be taken. In the above MO x , when x = 0, it is a metal, for example, and the upper limit of the range of x is the value when completely oxidized.

[0052] For packaging material applications, silicon oxide and aluminum oxide are preferably used, and it is preferable to use those with values of x in the range of 1.0 to 2.0 for silicon oxide and 0.5 to 1.5 for aluminum oxide. The gas barrier layer may be formed of one of these barrier material substances, may be used by combining two or more thereof, or may be used by mixing two or more thereof. Further, it may be composed of a single layer, may be composed of multiple layers of the same or different compositions, and in the case of multiple layers, they may not be laminated adjacent to each other.

[0053] As the resin film that supports the above vapor deposition layer, since a vapor deposition layer is provided thereon, a film of a resin having excellent properties in terms of mechanical, physical, chemical, and others, particularly having strength and toughness, and having heat resistance can be used.

[0054] Specifically, in the present invention, as the resin film that supports the above vapor deposition layer, for example, polyester-based resin films such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT), polyamide-based resin films such as various nylons, polyethylene-based resins, polypropylene-based resins, cyclic polyolefin resins, polystyrene-based resins, ac rylonitrile-styrene copolymer (AS resin), acrylonitrile-butadiene-styrene copolymer (ABS resin), polyolefin films such as polybutadiene resin films, polyvinyl chloride-based resins, polycarbonate-based resins, polyimide-based resins, polyamideimide-based resins, polyaryl phthalate resins, silicone-based resins, polysulfone-based resins, polyphenylene sulfide-based resins, polyether sulfone-based resins, polyurethane-based resins, cellulose-based resins, poly(meth)acrylic-based resins, polyvinylidene chloride films, acetal-based resin films, fluorine-based resins, and others can be used. In the present invention, in particular, it is preferable to use a film of a polypropylene-based resin, a polyester-based resin, or a polyamide-based resin.

[0055] As a method for forming an inorganic vapor deposition layer, an inorganic compound as described above is used as a raw material. For example, physical vapor deposition methods such as vacuum evaporation, sputtering, ion plating, and cluster ion beam methods (Physical Vapor Deposition method, PVD method), or chemical vapor deposition methods such as plasma chemical vapor deposition, thermal chemical vapor deposition, and photo-chemical vapor deposition (Chemical Vapor Deposition method, CVD method) can be utilized to form a vapor deposition layer on a resin film.

[0056] More specifically, in the above PVD method, for example, a roll-to-roll vapor deposition machine is used. In a vacuum chamber, the resin film taken out from the unwind roll is put into the vapor deposition chamber. Here, the vapor deposition source heated in a crucible is evaporated. Further, if necessary, while ejecting oxygen or the like from the oxygen outlet, an inorganic vapor deposition layer is formed on the resin film on the cooled coating drum through a mask, and then the resin film with the inorganic vapor deposition layer formed thereon is wound around the wind-up roll, whereby a resin film having an inorganic vapor deposition layer according to the present invention can be manufactured.

[0057] On the other hand, in the above CVD method, a mixed gas composed of, for example, an organosilicon compound as a monomer gas, oxygen gas, and an inert gas supplied from a vapor deposition raw material volatilization supply device is introduced onto the surface of the resin film fed out from the unwind roll arranged in the vapor deposition chamber on the circumferential surface of the cooling and electrode drum in the vapor deposition chamber, and a resin film having an inorganic vapor deposition layer such as silicon oxide formed by plasma can be manufactured. And in the present invention, in the resin film having an inorganic vapor deposition layer as described above, it prevents oxygen gas, or water vapor or the like from permeating, and functions as a gas barrier layer against these.

[0058] In the above, in order to obtain sufficient barrier properties, the thickness of the vapor deposition layer is preferably 30 Å to 3000 Å, more preferably 40 Å to 2500 Å, and even more preferably 50 Å to 2000 Å. More specifically, in the above PVD method, the thickness of the vapor deposition layer made of aluminum oxide is preferably 30 Å to 1000 Å, and more preferably about 50 Å to 500 Å. Also, in the above CVD method, the thickness of the vapor deposition layer made of silicon oxide is preferably 30 Å to 3000 Å, and more preferably 50 Å to 2000 Å. In general, in the case of a vapor deposition layer made of a metal oxide or an inorganic substance, if the thickness of the vapor deposition layer exceeds the above range, cracks and the like are likely to occur in the vapor deposition layer, and there is a risk that the barrier property will be reduced due to warping, and at the same time, the material cost will increase, which is not preferable. Also, if it is less than the above range, it is not preferable because it becomes difficult to exhibit the barrier property.

[0059] Also, for a resin film having an inorganic vapor deposition layer, the water vapor permeability measured in accordance with JIS K7129 method in an environment of a temperature of 40 °C and a humidity of 100% RH is preferably 3.0 g / m 2 ·day or less, more preferably 2.0 g / m 2 ·day or less, and even more preferably 1.5 g / m 2 ·day or less. If the water vapor permeability satisfies the above numerical range, the intrusion of water vapor from the outside of the package into the content accommodating portion inside the package can be sufficiently suppressed. Also, for a resin film having an inorganic vapor deposition layer, the oxygen permeability measured in accordance with JIS K7126 method in an environment of a temperature of 23 °C and a humidity of 90% RH is preferably 3.0 cc / m ·atm·day or less, more preferably 2.0 cc / m 2 ·atm·day or less, and even more preferably 1.0 cc / m 2 ·atm·day or less. If the oxygen permeability satisfies the above numerical range, the intrusion of oxygen from the outside of the package into the content accommodating portion inside the package can be sufficiently suppressed. 2

[0060] A barrier resin coating film or a barrier resin film made of a barrier resin can also be used as a barrier material and can also exhibit properties such as aroma retention. Examples of the barrier resin include films or coating films of resins rich in gas barrier properties such as polyvinylidene chloride-based resins (PVDC), polyester-based resins, polyamide-based resins (especially aromatic polyamides such as nylon MXD6), ethylene-vinyl alcohol copolymers (EVOH) with an ethylene content of 25 mol% to 50 mol% obtained by completely saponifying ethylene-vinyl acetate copolymers (vinyl acetate being approximately 79 wt% to 92 wt%), polyvinyl alcohol, polyacrylonitrile, and others. The thickness of the barrier resin coating film or the barrier resin film is arbitrary, but preferably 0.5 μm to 300 μm, more preferably 1 μm to 100 μm. As the gas barrier film, a resin film having a metal foil or a vapor deposition layer is preferred, and an aluminum foil is particularly preferred.

[0061] <Method for producing a water-absorbing laminate> For example, an example of producing a water-absorbing laminate by laminating a base material layer and a gas barrier layer on a water-absorbing sealant film will be described. The production method shown below is an example and does not limit the present invention. The lamination of the base material layer and the gas barrier layer can be performed by any method used when manufacturing ordinary packaging materials, such as wet lamination, dry lamination, solventless dry lamination, extrusion lamination, T-die coextrusion molding, coextrusion lamination, inflation method, and others. For example, a water-absorbing laminate can be obtained by laminating and adhering a base material layer, a gas barrier layer, and a water-absorbing sealant film through an adhesive layer laminated by an extrusion coating method, a dry lamination method, a non-solvent lamination method, or the like.

[0062] When laminating by the extrusion coating method, first, the resin composition for forming the adhesive layer is heated and melted, expanded and stretched in the required width direction by a T-die, and (co)-extruded in a curtain shape. The molten resin is allowed to flow down onto the surface to be laminated, and is sandwiched between a rubber roll and a cooled metal roll, so that the formation of the adhesive layer, the lamination on the surface to be laminated, and the adhesion can be carried out simultaneously. Alternatively, for example, first, a dry lamination adhesive is applied to one side of a resin film for a base material layer, dried, and adhered and laminated to a film for a barrier layer. Then, a dry lamination adhesive is applied to the surface of the barrier layer, dried, and adhered and laminated to a water-absorbing sealant film to obtain a water-absorbing laminate. And an aging treatment may be performed as necessary. In this way, a water-absorbing laminate can be obtained.

[0063] ≪All-solid-state lithium-ion battery package≫ The all-solid-state lithium-ion battery package of the present invention is a package produced by packaging a sulfide-based inorganic solid electrolyte type all-solid-state lithium-ion battery using the water-absorbing packaging material of the present invention. In the all-solid-state lithium-ion battery package, gas and / or liquid moisture is absorbed by the water-absorbing packaging material constituting the all-solid-state lithium-ion battery package, so that the generation of outgas is suppressed by suppressing the water absorption reaching the all-solid-state lithium-ion battery, and peeling and swelling are less likely to occur in the all-solid-state lithium-ion battery package.

Examples

[0064] <Raw materials> The main raw materials used in the examples of the present invention are as follows.

[0065] <Inorganic water absorbent> · Water absorbent 1: Calcium oxide, HAL-J, manufactured by Yoshizawa Lime Industry Co., Ltd. Average particle diameter 1 to 2 μm. · Desiccant 2: Magnesium oxide manufactured by Kojima Chemical Industry Co., Ltd., StarMag PSF-150. Average particle size 0.6 μm. · Desiccant 3: Zeolite manufactured by Mizusawa Chemical Industry Co., Ltd., Mizukasebs 5AP. SiO2 / Al2O3 molar ratio = 2 / 1, average particle size 5 μm. · Desiccant 4: Aluminum oxide manufactured by Nippon Light Metal Co., Ltd., A33F (SA30 series). Average particle size 2 μm.

[0066] [Thermoplastic resin, heat-sealable resin] · LDPE1: LDPE manufactured by Nippon Polyethylene Co., Ltd., Novatech LC520. Density 0.923 g / cm3, MFR 3.6 g / 10 min. · LLDPE1: LLDPE manufactured by Prime Polymer Co., Ltd., Ultrex 4020L. Density 0.937 g / cm 3 , MFR 2.3 g / 10 min. · LLDPE2: LLDPE manufactured by Prime Polymer Co., Ltd., Evolue SP2020. Density 0.916 g / cm 3 , MFR 2.0 g / 10 min. · PP1: PP manufactured by Nippon Polypropylene Co., Ltd., Wintech WFW4M. Density 0.9 g / cm 3 , MFR 7.0 g / 10 min.

[0067] [Others] · Nylon film 1: Nylon film manufactured by Toyobo Co., Ltd., Hardene film NAP02. 25 μm thick · PET film 1: Manufactured by Toyobo Co., Ltd. Biaxially oriented PET film, E5100. 12 μm thick. · Aluminum foil 1: Aluminum foil manufactured by Toyo Aluminum Co., Ltd., 8021 material. 40 μm thick. · DL adhesive 1: Dry lamination adhesive manufactured by Rock Paint Co., Ltd., RU-004 / H-1. · EC adhesive 1: Acid-modified polyethylene manufactured by Mitsui Chemicals, Inc., Admer NF528. · EC adhesive 2: Acid-modified polypropylene manufactured by Mitsui Chemicals, Inc., Admer QF551,

[0068] <Preparation of Masterbatch> [Preparation of Masterbatch 1] LDPE1 and water absorbent 1 were melt-blended at the following ratio to obtain masterbatch 1 (MB1). LDPE1 40 parts by mass Water absorbent 1 60 parts by mass [Preparation of Masterbatches 2 - 8] According to the formulation in Table 1, melt-blending was carried out in the same manner as for masterbatch 1 to obtain masterbatches 2 - 8 (MB2 - 8).

[0069]

Table 1

[0070] [Example 1] The following raw materials were mixed by dry blending to obtain a resin composition for the water-absorbing layer. MB1 50 parts by mass LLDPE1 50 parts by mass Next, nylon film 1 for the base material layer and aluminum foil 1 for the gas barrier layer were laminated by dry lamination (drying temperature: 70°C) through DL adhesive 1 (coating amount: 3.0 g / m 2 ) to produce a laminated film of nylon film 1 (25 μm) / DL adhesive 1 (3.5 g / m 2 ). Then, EC adhesive 1 and the resin composition for the water-absorbing layer obtained above were co-extruded on the aluminum foil 1 side of the laminated film obtained above, and a water-absorbing packaging material with the following layer structure was obtained by the co-extrusion lamination method. And various evaluations were carried out. Layer structure: Nylon film 1 (thickness 25 μm) / DL adhesive 1 (coating amount 3.0 g / m 2 ) / Aluminum foil 1 (thickness 40 μm) / EC adhesive 1 (thickness 15 μm) / Water-absorbing layer (thickness 30 μm)

[0071] [Examples 2 - 14, Comparative Examples 3, 4] According to the descriptions in Tables 2 to 5, masterbatches were selected to prepare resin compositions for the water-absorbing layer, materials for each layer were selected, and operations were carried out in the same manner as in Example 1 to obtain water-absorbing packaging materials, which were evaluated in the same way.

[0072] [Comparative Example 1] According to the description in Table 5, operations were carried out in the same manner as in Example 1, and a heat-sealing layer made of LLDPE1 was formed instead of the water-absorbing layer to obtain a packaging material, which was evaluated in the same way.

[0073] [Comparative Example 2] According to the description in Table 5, operations were carried out in the same manner as in Example 1, and a heat-sealing layer made of PP1 was formed instead of the water-absorbing layer to obtain a packaging material, which was evaluated in the same way.

[0074] [Summary of Results] The water-absorbing laminates of all examples of the present invention showed good manufacturing suitability, heat-sealability, and reduction of relative humidity. However, Comparative Example 1 that does not contain an inorganic water absorbent was inferior in the effect of reducing the sulfur-based gas concentration, and Comparative Example 2 in which the content of the inorganic water absorbent was too large was inferior in heat-sealability. Since Comparative Examples 3 and 4 had poor heat-sealability, subsequent evaluations were aborted, and the measurement and evaluation of the sulfur-based gas concentration were not performed.

[0075] [Table 2]

[0076] [Table 3]

[0077] [Table 4]

[0078] [Table 5]

[0079] <Evaluation>

[0080] [Manufacturing suitability] The appearance of the laminate was observed with the naked eye, and the presence or absence of defects was evaluated according to the following evaluation criteria. ◯: The laminate had no wrinkles, bumps, or peeling. ×: Wrinkles, bumps, or peeling were observed in the laminate.

[0081] [Heat sealability] The laminate was cut into 10 cm x 10 cm pieces, the sealant sides were overlapped, and a 1 cm x 10 cm area was heat sealed under the following conditions using a heat seal tester (TP-701-A manufactured by Tester Sangyo Co., Ltd.). The ends were not heat sealed or bonded, and a test piece for peel strength was prepared in which the ends were split into two. This test piece was cut into a strip of 15 mm width, and each bifurcated end was attached to a tensile tester to measure the peel strength (N / 15 mm) under the conditions below, and the pass / fail judgment was made according to the pass / fail judgment criteria below. Heat sealing conditions Temperature: 160℃ Pressure: 1kgf / cm 2 Time: 1 second Test conditions Test speed: 300mm / min Load range: 50N Pass / Fail Criteria ○: 30N / 15mm or more, passed. ×: Less than 30N / 15mm, failing.

[0082] [Relative Humidity] The packaging material was cut to a size of 20 x 20 cm, and 1000 ml of air adjusted to a relative humidity of 80% was placed into a gas sampling bag (IB-PET-PIR 12 μm / adhesive layer / ONy 15 μm / adhesive layer / LLDPE film 60 μm) together with a humidity data logger (T&D Corporation, TR-72wf). The relative humidity after leaving the bag at 25°C for 48 hours was measured using the temperature and humidity data logger. [Explanation of symbols]

[0083] 1 Water-absorbing packaging material 2 Base material layer 3 Intermediate layer 4 Gas barrier layer 5 Sealant layer 6 Water-absorbing layer 7 Inorganic water absorbent 8 Heat-sealing layer

Claims

1. A water-absorbing packaging material for a sulfide-based inorganic solid electrolyte type all-solid-state lithium-ion battery that absorbs gaseous water and / or liquid water, The water-absorbing packaging material includes at least a base layer made of a base film, a gas barrier layer made of a gas barrier film, and a sealant layer made of a water-absorbing sealant film, in this order. The sealant layer is a single-layer structure, and its thickness is 5 μm or more and 50 μm or less. One surface of the water-absorbing packaging material is the sealant layer. The water-absorbing sealant film contains an inorganic water absorbent and a heat-sealable resin (except when an acid trap is included). The inorganic water absorbent contains one or more selected from the group consisting of aluminum oxide, silica gel, alumina gel, and burnt alum. The content of the inorganic water absorbent in the layer containing the inorganic water absorbent is 2% by mass or more and 50% by mass or less. The water-absorbing packaging material is placed in a gas sampling bag adjusted to a relative humidity of 80%, and the relative humidity after leaving it at 25°C for 48 hours is 0 to 50%. Water-absorbing packaging material.

2. The base film contains a polyamide resin and / or a polyester resin. The water-absorbing packaging material according to Claim 1.

3. The gas barrier film is an aluminum foil. The water-absorbing packaging material according to Claim 1 or 2.

4. An all-solid-state lithium-ion battery package of a sulfide-based inorganic solid electrolyte type, produced from the water-absorbing packaging material according to any one of Claims 1 to 3.

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