JP2024050631A - Packaging material and packaging body for all-solid-state lithium-ion batteries - Google Patents

Abstract

The present invention provides a sulfur-based gas absorbing packaging material for all-solid-state lithium ion batteries, which has excellent manufacturability and a simple layer structure, and which absorbs sulfur-based gas generated from an all-solid-state lithium ion battery of a sulfide-based inorganic solid electrolyte type, and a packaging body thereof.
[Solution] A sulfur-based gas absorbing packaging material for an all-solid-state lithium ion battery of a sulfide-based inorganic solid electrolyte type that absorbs sulfur-based gases, the packaging material for all-solid-state lithium ion batteries includes at least a substrate layer made of a substrate film, a gas barrier layer made of a gas barrier film, and a sealant layer made of a sulfur-based gas absorbing sealant film, the sulfur-based gas absorbing sealant film contains a sulfur-based gas absorbent and a heat-sealable resin, and the content of the sulfur-based gas absorbent in the layer containing the sulfur-based gas absorbent is 0.3 mass % or more and 30 mass % or less.
[Selected Figure] Figure 1

Description

The present invention relates to a packaging material having sulfur-based gas absorbency for packaging an all-solid-state lithium ion battery of a sulfide-based inorganic solid electrolyte type, which absorbs sulfur-based gas generated from the all-solid-state lithium ion battery of a sulfide-based inorganic solid electrolyte type, and a package obtained by packaging an all-solid-state lithium ion battery of a sulfide-based inorganic solid electrolyte type 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 all-solid-state lithium ion battery products in various fields, and can be particularly suitably used as a packaging material for packaging large-capacity all-solid-state lithium ion batteries for home power storage systems, power sources for automobile electric motors, and the like.

Conventionally, packaging materials for packaging lithium-ion batteries have been required to have improved properties such as airtightness and water vapor barrier properties to prevent the intrusion of water vapor from the outside, chemical resistance to prevent electrolyte leakage, and heat resistance to prevent melting and electrolyte leakage when the lithium-ion battery generates heat (Patent Document 1).
However, in recent years, when it is assumed that the lithium-ion battery packaging will be used for a long period of time, such as about 20 years, for example, in vehicle or home use, there has been concern that in the case of an all-solid-state lithium-ion battery, sulfur-based gas generated by decomposition of the electrolyte during charging will accumulate, causing the lithium-ion battery packaging to expand or break.
As a method for removing sulfur-based gases, a resin film containing a flavonoid-based compound has been proposed (Patent Document 2). However, since the flavonoid-based compound has poor heat resistance, there are limitations on the heating conditions in the manufacturing process of the resin film, and the effect of removing sulfur-based gases is insufficient.
In addition, as a resin film for removing sulfur-based gases, a resin film containing an antifogging agent made of zeolite, copper-containing metal silicate, and glycerin esters has been proposed (Patent Document 3). However, the main focus was on removing moisture and ethylene gas, and the effect of removing sulfur-based gases was insufficient. The adsorption and decomposition mechanism of sulfur-based gases (hydrogen sulfide) in metal silicates proceeds by oxidation-reduction reactions, but in a closed space such as a lithium battery packaging body, the oxygen concentration (hydrogen concentration) is also limited, so that it is insufficient in terms of the sustainability of the adsorption effect when the durability of about 20 years required for lithium-ion batteries is assumed. The adsorption and decomposition mechanism of sulfur-based gases (hydrogen sulfide) in metal silicates proceeds by oxidation-reduction reactions, but in a closed space such as a lithium battery packaging body, the oxygen concentration (hydrogen concentration) is also limited, so that it is insufficient in terms of the sustainability of the adsorption effect when the durability of about 20 years required for lithium-ion batteries is assumed. The adsorption and decomposition mechanism of sulfur-based gases (hydrogen sulfide) in metal silicates proceeds through an oxidation-reduction reaction. However, in a closed space such as a lithium battery packaging, the oxygen concentration (hydrogen concentration) is also limited, and so the durability of the adsorption effect is insufficient when considering the approximately 20-year lifespan required for lithium-ion batteries.

JP 2015-38881 A Japanese Patent Application Laid-Open No. 1-207339 JP 2019-069817 A

The present invention aims to solve the above-mentioned problems and provide a sulfur-based gas absorbing packaging material for all-solid-state lithium-ion batteries that has excellent manufacturability and a simple layer structure while absorbing sulfur-based gas generated from an all-solid-state lithium-ion battery of a sulfide-based inorganic solid electrolyte type, and a sulfur-based gas absorbing sulfide-based inorganic solid electrolyte type all-solid-state lithium-ion battery package obtained by packaging an all-solid-state lithium-ion battery with the sulfur-based gas absorbing packaging material.

After extensive investigations, the inventors have found that a sulfur-based gas absorbing packaging material for all-solid-state lithium-ion batteries containing a thermoplastic resin and a specific sulfur-based gas absorbent achieves the above-mentioned objective.

That is, the present invention is characterized in the following points.
1. A sulfur-based gas absorbing packaging material for an all-solid-state lithium ion battery of a sulfide-based inorganic solid electrolyte type, which absorbs a sulfur-based gas, comprising:
The packaging material for an all-solid-state lithium-ion battery includes at least a substrate layer made of a substrate film, a gas barrier layer made of a gas barrier film, and a sealant layer made of a sulfur-based gas absorbing sealant film,
The sulfur-based gas absorbing sealant film contains a sulfur-based gas absorbent and a heat-sealable resin,
The content of the sulfur-based gas absorbent in the layer containing the sulfur-based gas absorbent is 0.3 mass% or more and 30 mass% or less.
Sulfur-based gas absorbing packaging material.
2. The sulfur-based gas absorbent contains a sulfur-based gas chemical absorbent and/or a sulfur-based gas physical absorbent;
2. The sulfur-based gas absorbing packaging material according to claim 1.
3. The sulfur-based gas absorbent has a maximum particle size of 20 μm or less and a number average particle size of 0.1 μm or more and 15 μm or less.
3. The sulfur-based gas absorbing packaging material according to 1 or 2 above.
4. The sulfur-based gas chemical absorbent is a metal oxide and/or an inorganic material having a metal or metal ion supported thereon or mixed therein.
4. A sulfur-based gas absorbing packaging material according to 2 or 3 above.
5. The metal oxide contains one or more selected from the group consisting of CuO, ZnO, and AgO.
5. The sulfur-based gas absorbing packaging material according to 4 above.
6. The metal species in the inorganic material in which the metal or metal ion is supported or mixed includes one or more selected from the group consisting of Ca, Mg, Na, Cu, Zn, Ag, Pt, Au, Fe, Al, and Ni;
6. A sulfur-based gas absorbing packaging material according to 4 or 5 above.
7. The sulfur-containing gas physical absorbent contains one or more selected from the group consisting of hydrophobic zeolite, bentonite, and sepiolite having a SiO ₂ /Al ₂ O ₃ molar ratio of 1/1 to 2000/1;
7. A sulfur-based gas absorbing packaging material according to any one of 2 to 6 above.
8. The base film contains a polyamide resin and/or a polyester resin.
8. A sulfur-based gas absorbing packaging material according to any one of 1 to 7 above.
9. The gas barrier film is an aluminum foil.
9. A sulfur-based gas absorbing packaging material according to any one of 1 to 8 above.
10. A sulfur-based gas-absorbing all-solid-state lithium-ion battery packaging body produced from the sulfur-based gas-absorbing packaging material according to any one of 1 to 9 above.

The sulfur-based gas absorbing packaging material for all-solid-state lithium-ion batteries of the present invention solves the above-mentioned problems, has excellent manufacturing suitability, and has a simple layer structure, while having excellent absorption properties and excellent heat sealability for the sulfur-based gas generated from all-solid-state lithium-ion batteries of sulfide-based inorganic solid electrolyte type, and can exert the effect of making peeling and swelling caused by the sulfur-based gas generated from all-solid-state lithium-ion batteries of sulfide-based inorganic solid electrolyte type difficult to occur.

FIG. 1 is a schematic cross-sectional view showing an example of a layer structure of a sulfur-based gas absorbing packaging material for an all-solid-state lithium ion battery according to the present invention. FIG. 2 is a schematic cross-sectional view showing an example of another embodiment of the layer structure of the sulfur-based gas absorbing packaging material for an all-solid-state lithium ion battery of the present invention. FIG. 2 is a schematic cross-sectional view showing another example of the layer structure of the sulfur-based gas absorbing packaging material for an all-solid-state lithium ion battery according to the present invention.

In each drawing, the size and ratio of the components may be changed or exaggerated for ease of understanding. Also, for ease of understanding, parts that are not necessary for the explanation or repeated reference numerals may be omitted.
Although not shown in the drawings, an adhesive layer may be provided between each layer.
Furthermore, if necessary, in order to strengthen the adhesive strength (adhesion strength) between each layer, the laminated surfaces of each layer may be previously subjected to a physical surface treatment such as corona discharge treatment, ozone treatment, plasma treatment, glow discharge treatment, sandblasting treatment, etc., or a chemical surface treatment such as oxidation treatment using chemicals.

The sulfur-based gas absorbing packaging material for an all-solid-state lithium ion battery of the sulfide-based inorganic solid electrolyte type according to the present invention will be described in more detail below. Specific examples will be given, but the present invention is not limited thereto.

(Gas to be absorbed)
In the present invention, the gas to be absorbed is a sulfur-based gas.
In the present invention, examples of sulfur-based gases include hydrogen sulfide, dimethyl sulfide, methyl mercaptan, and sulfur oxides represented by _SOx .

<All-solid-state lithium-ion battery>
A typical lithium-ion battery is composed of a positive electrode made of an oxide containing lithium, a negative electrode containing a carbon material, a separator, and an electrolyte.
Here, the electrolyte can be either liquid or solid, and an all-solid-state lithium-ion battery refers to a battery in which the electrolyte is a solid.
Moreover, a typical lithium ion battery is a secondary battery that can be charged and discharged by the movement of lithium ions between a positive electrode and a negative electrode, and in the present invention, the lithium ion battery refers to such a secondary battery.
As the solid electrolyte, there are oxide-based and sulfide-based electrolytes, with the sulfide-based electrolytes being preferred since they are capable of producing higher output.
The above-mentioned sulfide-based solid electrolyte is a compound that easily reacts with moisture to generate sulfur-based gas. When an 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.
The cumulative amount of sulfur-based gas generated in all-solid-state lithium-ion batteries for in-vehicle use or home energy storage system use, which are expected to be used for approximately 20 years or more, will be extremely large. Therefore, there are concerns about the pouches that contain the sulfur-based gas, such as expansion and tearing due to the sulfur-based gas, and corrosion of metal foil layers such as aluminum foil, and measures to address these issues will be necessary.

<Sulfur gas absorbing packaging material>
The sulfur-based gas absorbing packaging material for lithium ion batteries of the present invention is particularly suitable for use with all-solid-state lithium ion batteries of the sulfide-based inorganic solid electrolyte type, which generate a large amount of sulfur-based gas.
The sulfur-based gas absorbing packaging material for lithium ion batteries of the present invention is capable of absorbing the above-mentioned sulfur-based gas generated from solid electrolyte type lithium ion batteries.

The sulfur-based gas absorbing packaging material for an all-solid-state lithium ion battery of the present invention comprises at least a substrate layer made of a substrate film, a gas barrier layer made of a gas barrier film, and a sealant layer made of a sulfur-based gas absorbing sealant film, and the sulfur-based gas absorbing sealant film preferably contains a sulfur-based gas absorbent and a heat-sealable resin, and the sulfur-based gas absorbent preferably contains a chemical sulfur-based gas absorbent and/or a physical sulfur-based gas absorbent.
The gas barrier layer is preferably laminated between the substrate layer and the sulfur-based gas absorbing layer.
The sulfur-based gas absorbing packaging material may further include intermediate layers that perform various functions, as required.
The layers constituting the sulfur-based gas absorbing packaging material may be laminated via an adhesive layer.
The sulfur-based gas absorbing packaging material is a packaging material made from the sulfur-based gas absorbing laminate including the above-mentioned base layer, gas barrier layer, and sealant layer.
One surface of the sulfur-based gas absorbing packaging material for an all-solid-state lithium ion battery is preferably heat-sealable, and therefore, it is preferable that the sulfur-based gas absorbing film is laminated so that the heat-sealable surface of the sulfur-based gas absorbing packaging material constitutes one surface of the sulfur-based gas absorbing packaging material.
The sulfur-based gas absorbing packaging material may further contain various plastic compounding agents and additives for the purpose of improving or modifying, for example, processability, heat resistance, weather resistance, mechanical properties, dimensional stability, oxidation resistance, slipperiness, release properties, flame retardancy, mold resistance, electrical properties, strength, etc. The content of these may be any amount ranging from a trace amount to several tens of percent depending on the purpose.
In the above, typical additives that may be contained include, for example, antiblocking agents, lubricants, crosslinking agents, antioxidants, ultraviolet absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, pigments, modifying resins, and the like.

<Sealant Layer>
The sealant layer is a layer containing a sulfur-based gas absorbent and a heat-sealable resin, and has sulfur-based gas absorbency and heat-sealability.
The sealant layer is preferably a layer made of a sulfur-based gas absorbing sealant film.
The sulfur-based gas absorbing sealant film is a sulfur-based gas absorbing film having heat sealability, and can be produced by incorporating a heat sealable resin into the sulfur-based gas absorbing film or by laminating a layer containing a heat sealable resin onto the sulfur-based gas absorbing film.
The sealant layer can impart sulfur-based gas absorbency to the sulfur-based gas absorbent packaging material by containing a sulfur-based gas absorbent, and can impart heat sealability to the sulfur-based gas absorbent packaging material by containing a heat sealable resin.
The outer surface of the sealant layer preferably has heat sealability by containing a heat sealable resin.
Furthermore, the sealant layer may further include a layer derived from a material other than the sulfur-based gas absorbing sealant film, if necessary. For example, it may further include a support layer for reinforcing the support.
The sealant layer may be of a single layer construction or of a multi-layer construction of two or more layers having the same or different compositions.
For example, it may be one layer containing a sulfur-based gas absorbent and a heat-sealable resin, or it may be two layers, a sulfur-based gas absorbing layer containing a sulfur-based gas absorbent and a heat-sealable resin without containing a sulfur-based gas absorbent.Furthermore, the sulfur-based gas absorbing layer may be one or more of a layer containing only a sulfur-based gas physical absorbent, a layer containing only a sulfur-based gas chemical absorbent, or a layer containing both a sulfur-based gas physical absorbent and a sulfur-based gas chemical absorbent.Here, the sulfur-based gas absorbing layer may contain a heat-sealable resin.
The thickness of the sealant layer is not particularly limited, but 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 sulfur-based gas absorption effect, and if it is thicker than the above range, the rigidity is too high, and it is easy to deteriorate the usability as a packaging material or packaging material.

<Sulfur gas absorbing film>
The sulfur-containing gas absorbing film of the present invention is a gas absorbing film that absorbs a sulfur-containing gas.

The sulfur-containing gas absorbing layer contains at least a thermoplastic resin and a specific sulfur-containing gas absorbent.
The sulfur-based gas absorbing film exhibits sulfur-based gas absorption by containing a sulfur-based gas absorbent, and the thermoplastic resin disperses the sulfur-based gas absorbent and is contained as a resin component constituting the sulfur-based gas absorbing film.
The sulfur-based gas absorbent may contain a sulfur-based gas chemical absorbent and/or a sulfur-based gas physical absorbent.
Furthermore, the sulfur-based gas absorbing film may further contain a heat-sealable resin, if necessary. By further containing a heat-sealable resin, the sulfur-based gas absorbing film can exhibit heat-sealability.

The sulfur-based gas absorbing film may be composed of one layer, or may be composed of two or more layers having the same or different compositions.
For example, there may be two layers, a layer containing a sulfur-based gas absorbent (sulfur-based gas absorbing layer) and a layer not containing a sulfur-based gas absorbent. There may also be a layer containing only a sulfur-based gas physical absorbent and a layer containing only a sulfur-based gas chemical absorbent, or there may be a layer containing both a sulfur-based gas physical absorbent and a sulfur-based gas chemical absorbent. There may also be layers with different contents of sulfur-based gas absorbents.
The heat-sealable resin may be contained in the sulfur-based gas absorbing layer, or may be contained in a layer that does not contain a sulfur-based gas absorbent to form a heat-sealable layer.
Furthermore, the sulfur-based gas absorbing film may have a support layer for reinforcing the supportability, if necessary.
The layers constituting the sulfur-based gas absorbing film may be laminated via an adhesive layer.

The content of the sulfur-based gas absorbent in the layer containing the sulfur-based gas absorbent is preferably 0.5% by mass or more and 30% by mass or less, and more preferably 1% by mass or more and 29% by mass or less. If the content is less than the above range, there is a risk that sufficient sulfur-based gas absorption cannot be achieved, and if the content is more than the above range, there is a risk that the sulfur-based gas absorption will not be particularly improved, and the interlayer adhesion and heat sealability may decrease, or the layer may become brittle.

The sulfur-based gas absorbing film may contain various plastic compounding agents and additives for the purpose of improving or modifying, for example, processability, heat resistance, weather resistance, mechanical properties, dimensional stability, oxidation resistance, slipperiness, release properties, flame retardancy, mold resistance, electrical properties, strength, etc. The content of these may range from a trace amount to several tens of percent, and may be arbitrarily determined depending on the purpose.
In the above, typical additives that may be contained include, for example, antiblocking agents, lubricants, crosslinking agents, antioxidants, ultraviolet absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, pigments, modifying resins, and the like.

There is no particular limit to the thickness of the sulfur-based gas absorbing film, but it is preferably 10 μm or more and 100 μm or less. If it is thinner than the above range, it will have too low rigidity, be easily torn, and will be difficult to exert a sufficient sulfur-based gas absorbing effect, and if it is thicker than the above range, it will be too rigid and will be difficult to use as a packaging material or packaging supplies.

[Sulfur gas absorption layer]
The sulfur-based gas absorbing layer is a layer containing a sulfur-based gas absorbent, and also contains a thermoplastic resin for dispersing the sulfur-based gas absorbent. The sulfur-based gas absorbing layer may also contain a heat-sealable resin, and if it has sufficient heat-sealability, it can also serve as a sealant layer.
Although there is no particular limitation on the thickness of the sulfur-based gas absorbing layer, 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 sulfur-based gas absorbing effect, and if it is thicker than the above range, the sulfur-based gas absorbing effect is not improved significantly, and the film becomes too rigid, which tends to make it difficult to use as a packaging material.

[Sulfur gas absorbent]
The sulfur-based gas absorbent preferably contains a sulfur-based gas physical absorbent and/or a sulfur-based gas chemical absorbent.
By using various types of sulfur-based gas absorbents in combination, for example, by using a sulfur-based gas physical absorbent and a sulfur-based gas chemical absorbent in combination, it becomes possible to easily absorb a variety of sulfur-based gases.
The sulfur-based gas absorbent is used in the form of a powder, and the maximum particle size is preferably 20 μm or less, and the number average particle size of the powder is preferably 0.1 μm or more and 20 μm or less. If the number average particle size is smaller than the above range, the sulfur-based gas absorbent is likely to aggregate, and if the number average particle size is larger than the above range, the homogeneity of the sulfur-based gas absorbing film may be deteriorated, and the surface area of the sulfur-based gas absorbent may be reduced, resulting in poor sulfur-based gas absorption.

The sulfur-based gas absorbent contained in the sulfur-based gas absorbing layer is preferably contained via a master batch in which a powdered sulfur-based gas absorbent is melt-blended with a thermoplastic resin.
Specifically, it is preferable to melt-blend a powdered sulfur-based gas 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 sulfur-based gas absorbent and the thermoplastic resin to be melt-blended may each be one type or two or more types.
The content of the sulfur-based gas absorbent 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 sulfur-based gas absorbent in the sulfur-based gas absorbing layer in a dispersed state.

(Sulfur gas physical absorbent)
The sulfur-containing gas physical absorbent is a gas absorbent that has the function of physically absorbing the sulfur-containing gas to be absorbed.
The sulfur-containing gas physical absorbent preferably contains one or more types selected from the group consisting of hydrophobic zeolite, bentonite, and sepiolite having a SiO ₂ /Al ₂ O ₃ molar ratio of 1/1 to 2000/1.

Hydrophobic zeolites are zeolites that have excellent absorption properties for molecules with low polarity, such as sulfur-based gases, and have a porous structure.
Generally, the higher the molar ratio of _SiO2 / _Al2O3 , which are the components of zeolite, the more hydrophobic the _zeolite becomes. This increases the hydrophobicity of the zeolite, making it easier to absorb molecules with low polarity, such as sulfur-based gases, but conversely, it decreases the affinity of the zeolite with highly polar molecules, such as water, making it more difficult to absorb these molecules.
The SiO ₂ /Al ₂ O ₃ molar ratio of the hydrophobic zeolite is preferably from 30/1 to 10,000/1, more preferably from 35/1 to 9,000/1, and even more preferably from 40/1 to 8,500/1.
In addition, hydrophobic zeolite has high heat resistance and can maintain its absorption effect even when exposed to high temperatures of 230° C. or higher.
In the present invention, a hydrophobic zeolite having a molar ratio within the above range is preferably used from the viewpoint of the balance between the sulfur-containing gas absorption capacity and the ease of availability.

Bentonite is an inorganic substance whose main component is the clay mineral montmorillonite, containing a large amount of layered aluminum phyllosilicate and containing minerals such as quartz and feldspar as impurities.
Bentonite includes, for example, Na-type bentonite, which contains a lot of Na ⁺ ions, Ca-type bentonite, which contains a lot of ^Ca2+ ions, and activated bentonite, which is artificially converted to Na-type by adding a few wt% of sodium carbonate to Ca-type bentonite.

Sepiolite is a clay mineral whose main component is hydrated magnesium silicate, and has a porous structure with a general chemical composition of Mg ₈ Si ₁₂ O ₃₀ (OH ₂ ) ₄ (OH) _{4.6-8H 2} O. From the viewpoint of availability, the pH (3% suspension) is preferably 8.0-9.0, and more preferably 8.9-9.3.

(Sulfur gas chemical absorbent)
The sulfur-containing gas chemical absorbent is a gas absorbent that has the function of chemically absorbing or decomposing the sulfur-containing gas in the gas to be absorbed.
In addition, since the method is chemical absorption or decomposition, it is not easily affected by water, etc., and the sulfur-based gas molecules once absorbed are not easily desorbed, so that the absorption can be performed efficiently. Furthermore, the decomposition products are absorbed by a physical absorbent for a sulfur-based gas or a chemical absorbent for a sulfur-based gas.
The sulfur-based gas chemical absorbent preferably contains one or more types selected from the group consisting of inorganic materials carrying metal oxides, glass mixed with metals, and glass mixed with metal ions.
The metal oxide in the inorganic material carrying a metal oxide preferably contains one or more types selected from the group consisting of CuO, ZnO and AgO.
The inorganic substance to be supported is preferably an inorganic porous material such as zeolite.
The metal in the glass mixed with a metal, or the metal species of the metal ions in the glass mixed with a metal ion preferably includes one or more species selected from the group consisting of Ca, Mg, Na, Cu, Zn, Ag, Pt, Au, Fe, Al, and Ni.

[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 sulfur-based gas absorbent 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 low-density polyethylene (LLDPE), ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-methyl methacrylic acid copolymer, ethylene-propylene copolymer, and mixtures of these resins.
Among the above, polyethylene-based resins are preferred, and among the polyethylene-based resins, LDPE, LLDPE, general-purpose PE, PE-based copolymers, etc. are more preferred, with LLDPE being even more preferred.

[Heat sealable resin]
The heat-sealable resin is not particularly limited, and any known resin can be used as long as it can be melted and fused by heat.
Specific examples of heat-sealable resins include polyethylene, low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, metallocene polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ionomer resin, ethylene-ethyl (meth)acrylate copolymer, ethylene-(meth)acrylic acid copolymer, ethylene-propylene copolymer, methylpentene polymer, polyolefin resins obtained by modifying polyolefin resins such as polyethylene or polypropylene with unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic anhydride, fumaric acid, and the like, terpolymer resins of ethylene-(meth)acrylic acid ester-unsaturated carboxylic acid, cyclic polyolefin resins, cyclic olefin copolymers, polyethylene terephthalate (PET), polyacrylonitrile (PAN), and the like.
Among these, polyolefin resins are preferred, polyethylene resins are more preferred, and low-density polyethylene and linear low-density polyethylene are even more preferred.

[Heat seal layer]
The heat seal layer is a layer that contains a heat sealable resin and has sufficient heat sealability, and may or may not contain a sulfur-based gas absorbent.

[Support layer]
The support layer is a layer that is included as necessary, and is included, for example, to supplement the rigidity of the sulfur-based gas absorbing film and can also have the effect of preventing blocking when the sulfur-based gas absorbing film is rolled or stacked.
The resin contained in the support layer is preferably LDPE or LLDPE, and may also contain a heat-sealable resin.
The thickness of the support layer is not particularly limited, but is preferably 1 μm or more and 50 μm or less. If it is thinner than the above range, it is difficult to exert the effect of reinforcing rigidity, and if it is thicker than the above range, the rigidity is too strong and it is likely to become difficult to use as a packaging material or packaging material.

<Adhesive Layer>
There are no particular limitations on the adhesive used in the adhesive layer, and adhesives for dry lamination, adhesives for EC (extrusion coating), adhesives for non-solvent lamination, any anchor coating agent, and the like can be used.
The adhesive may be of any of the following types: heat-curable, ultraviolet-curable, and electron-beam-curable types; and may be in any form, such as aqueous, solution, emulsion, and dispersion types. The adhesive may be in any form, such as film/sheet, powder, and solid. The adhesive mechanism may be any of the following types: chemical reaction, solvent volatilization, thermal melting, and thermal pressure.

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

[Sulfur-based gas absorbing sealant film]
The sulfur-based gas-absorbing sealant film is a sealant film produced from a sulfur-based gas-absorbing film, and has the same sulfur-based gas absorption as the sulfur-based gas-absorbing film, and excellent heat sealability.
When the sulfur-based gas absorbing film has sufficient heat sealability and supportability, the sulfur-based gas absorbing film can be used as it is as a sulfur-based gas absorbing sealant film, and if necessary, a support layer can be further laminated thereon, a heat sealable resin can be contained therein, or a layer containing a heat sealable resin can be laminated thereon to produce a sulfur-based gas absorbing sealant film.

The sulfur-based gas absorbing sealant film may have a single layer structure or a multi-layer structure having two or more layers.
In the case of a multi-layer structure, a support layer or a heat seal layer can be laminated on a layer derived from a sulfur-based gas absorbing film to prepare a sulfur-based gas absorbing sealant film. If necessary, various functional layers can be further laminated to prepare a sulfur-based gas absorbing sealant film. Here, each layer constituting the sulfur-based gas absorbing sealant film may be laminated via an adhesive layer.
It is preferable that one or both surfaces of the sulfur-based gas-absorbing sealant film have heat-sealability, and for this purpose, for example, a heat-seal layer may be laminated on one or both surfaces of the sulfur-based gas-absorbing sealant film.
By providing the sulfur-based gas absorbing sealant film with heat sealability on both sides, it is possible to produce a sulfur-based gas absorbing laminate having excellent interlayer adhesion and heat sealability within the sulfur-based gas absorbing laminate.

There is no particular limit to the thickness of the sulfur-based gas absorbing sealant film, but it is preferably 10 μm or more and 100 μm or less. If it is thinner than the above range, it will have too low rigidity, be easily torn, and will be difficult to exert a sufficient sulfur-based gas absorbing effect, and if it is thicker than the above range, it will be too rigid and will be difficult to use as a packaging material or packaging material.

<<Method of producing sulfur-based gas absorbing film and sulfur-based gas absorbing sealant film>>
The preparation method described below is merely an example and is not intended to limit the present invention.
There are no particular limitations on the method for forming and laminating the sulfur-based gas absorbing film or sulfur-based gas absorbing sealant film and the layers that constitute them, and any known or commonly used film forming and laminating method can be used.
The sulfur-based gas absorbing film or sulfur-based gas absorbing sealant film can be produced by a known film forming method and/or lamination method such as (co)extrusion, cast molding, T-die method, cutting method, or inflation method.
When the sulfur-based gas absorbing film or sulfur-based gas absorbing sealant film is composed of two or more layers, for example, films constituting each layer that have been previously prepared may be laminated via an adhesive layer, a molten resin composition may be laminated onto a previously prepared layer by (co)extrusion, a plurality of layers may be simultaneously prepared and laminated by melt pressure bonding, or one or more types of resins may be applied and dried to coat another layer.
For example, a sulfur-based gas absorbing sealant film can be produced by laminating a heat seal layer on a sulfur-based gas absorbing film.

The sulfur-based gas absorbing layer or the heat seal layer may be laminated on another layer by extrusion or coextrusion, or may be laminated via an adhesive layer after film formation by inflation or casting. Even in the case of the extrusion coating method, an adhesive layer may be laminated as necessary.
Alternatively, a film for a sulfur-based gas absorbing layer or a film for a heat seal layer that has been previously formed may be laminated and bonded via an adhesive layer that has been laminated by an extrusion coating method, a dry lamination method, a non-solvent lamination method, or the like.
Then, an aging treatment may be carried out as necessary.

For example, in the case of laminating a sulfur-based gas absorbing layer or a heat seal layer by an extrusion coating method, first, a resin composition forming the layer is heated and melted, and expanded and stretched in the required width direction using a T-die to be (co)extruded in a curtain shape, and the molten resin is caused to flow down onto the surface to be laminated and sandwiched between a rubber roll and a cooled metal roll, thereby simultaneously forming the layer and laminating and adhering to the surface to be laminated.
When laminating layers by extrusion coating, the melt flow rate (MFR) of the resin component contained in each layer 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.

When using the inflation method, the melt flow rate (MFR) of the resin component contained in each layer is preferably 0.2 to 10 g/10 min, and 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.

Furthermore, in order to improve adhesion between the layers constituting the sulfur-based gas absorbing film or the sulfur-based gas absorbing sealant film, a desired surface treatment may be applied in advance to the surface of each layer, if necessary.
For example, a corona-treated layer, an ozone-treated layer, a plasma-treated layer, an oxidation-treated layer, or the like can be formed by optionally carrying out pretreatment such as corona discharge treatment, ozone treatment, low-temperature plasma treatment using oxygen gas or nitrogen gas, or the like, glow discharge treatment, or oxidation treatment using chemicals, or the like.
Alternatively, various coating layers such as a primer coating layer, an undercoating layer, an anchor coating layer, an adhesive layer, and a vapor-deposited anchor coating layer may be optionally formed on the surface to form a surface treatment layer.
For the various coating agent layers, for example, a resin composition containing a polyester-based resin, a polyamide-based resin, a polyurethane-based resin, an epoxy-based resin, a phenol-based resin, a (meth)acrylic resin, a polyvinyl acetate-based resin, a polyolefin-based resin such as polyethylene or polypropylene, or a copolymer or modified resin thereof, a cellulose-based resin, or the like as a main component of the vehicle can be used.

Each layer constituting the sulfur-based gas absorbing film or sulfur-based gas absorbing sealant film can be further uniaxially or biaxially stretched by a conventionally known method using a tenter system, a tubular system, or the like, as necessary.

<Sulfur-based gas absorbing laminate>
The sulfur-based gas absorbing laminate of the present invention is a laminate obtained by laminating the sulfur-based gas absorbing film of the present invention or the sulfur-based gas absorbing sealant film of the present invention with, for example, a base material layer or a gas barrier layer, and has sulfur-based gas absorption similar to that of the sulfur-based gas absorbing film.
The sulfur-based gas absorbing laminate may further include intermediate layers having various functions, as required.
One surface of the sulfur-containing gas absorbing laminate is preferably a heat seal layer so that the sulfur-containing gas absorbing laminate has heat sealability.
The gas barrier layer is preferably laminated between the substrate layer and the sulfur-based gas absorbing layer.
Furthermore, each layer constituting the sulfur-based gas absorbing laminate may be laminated via an adhesive layer.
Then, an aging treatment may be carried out as necessary.

The sulfur-based gas absorbing laminate or each layer constituting the sulfur-based gas absorbing laminate may contain various plastic compounding agents and additives for the purpose of improving or modifying, for example, processability, heat resistance, weather resistance, mechanical properties, dimensional stability, oxidation resistance, slipperiness, releasability, flame retardancy, mold resistance, electrical properties, strength, etc. The content of these may be any amount ranging from a trace amount to several tens of percent depending on the purpose.
In the above, typical additives that may be contained include, for example, antiblocking agents, lubricants, crosslinking agents, antioxidants, ultraviolet absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, pigments, modifying resins, and the like.

<Base layer>
The material of the substrate layer may be a commonly known substrate film having excellent mechanical, physical, chemical, and other properties, particularly strength, toughness, and heat resistance. As the substrate film, various resin films may be used, and further, various paper substrates may be used, and a resin film and a paper substrate may be used in combination.
The substrate layer may be composed of one layer, or may be composed of two or more layers of the same or different compositions laminated by any lamination means.
The thickness of the base material layer can be appropriately set by a person skilled in the art. For the purpose of imparting appropriate strength and stiffness 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.

Specific examples of the resin film include resin films made of tough thermoplastic resins such as polyester-based resins such as polyethylene terephthalate (PET) and polyethylene naphthalate, polyolefin-based resins such as polypropylene, polyamide-based resins such as nylon, polyaramid-based resins, polycarbonate-based resins, polyacetal-based resins, fluorine-based resins, and others.
The resin film may be either an unstretched film or a uniaxially or biaxially stretched film.
Among the above, resin films containing polyester-based resins and/or polyamide-based resins are preferred, and biaxially oriented PET films and biaxially oriented nylon films are more preferably used.

The paper base material can provide properties such as shapeability, flex resistance, and rigidity. For example, a strong sizing bleached or unbleached paper base material for a paper layer, or a paper base material such as pure white roll paper, kraft paper, paperboard, processed paper, milk base paper, and others can be used.
The paper base material preferably has a basis weight of about 30 g/m ² to 600 g/m ² , and more preferably has a basis weight of about 50 g/m ² to 450 g/m ² .

If necessary, plastic compounding agents and additives such as lubricants, crosslinking agents, antioxidants, UV absorbers, light stabilizers, fillers, reinforcing agents, antistatic agents, and pigments may be added to the resin film used for the base layer for the purpose of improving or modifying processability, heat resistance, weather resistance, mechanical properties, dimensional stability, oxidation resistance, slipperiness, release properties, flame retardancy, mildew resistance, electrical properties, strength, and the like. The amount of these additives may be arbitrarily added depending on the purpose as long as it does not adversely affect other performance properties.
A printed layer may be provided on one or both sides of the base layer.

[Printed layer]
The printed layer visually presents design patterns such as letters, numbers, figures, symbols, pictures, patterns, etc. for the purpose of decoration, indication of contents, indication of expiration date, indication of manufacturer, seller, etc., and for imparting aesthetic appeal, and can form the desired design pattern.
The printed layer is preferably formed on one or both sides of the base layer by a printing method such as gravure printing or flexographic printing. The printed layer may be provided on the entire surface of the printed surface, or may be provided on only a part of the surface.
By forming the printed layer inside the laminate, the adhesion of the printed layer can be improved, and the ink on the printed layer can be prevented from being rubbed off or peeled off due to external impact or friction.
When the printed layer is present inside the laminate, it is preferable that the layer that is on the outer side of the printed layer when the package is formed is transparent so that the printed layer can be visually confirmed.

[Gas barrier layer]
The barrier layer is a layer that suppresses the permeation of gas, and when a sulfur-based gas absorbing package is produced, the barrier layer can suppress the intrusion of oxygen and water vapor from the outside of the sulfur-based gas absorbing package into the content storage section inside the package, and can suppress the diffusion of gas components generated from the content to the outside of the barrier layer. The permeation of the gas to be absorbed in the present invention can also be suppressed in the same manner.
Various barrier materials can be used for the gas barrier layer. In addition, the barrier material may have a light-shielding property against sunlight and the like, an aroma-retaining property for the contents, etc., in addition to oxygen and water vapor. In addition, a barrier material having a gas barrier property against water vapor and the like, a light-shielding property against sunlight and the like, an aroma-retaining property for the contents, etc., may be used in combination.

As the above-mentioned barrier material, it is preferable to use a gas barrier film. Specifically, for example, one or more types selected from the group consisting of a metal foil, a resin film having an inorganic vapor deposition layer, and a resin coating film or resin film made of an oxygen barrier resin can be used.
In particular, a resin film having a metal vapor deposition layer, a resin film having a metal oxide vapor deposition layer, or a resin coating film or film made of a barrier resin is preferred, as it has excellent barrier properties against oxygen gas, water vapor, light blocking, aroma retention, etc., and is environmentally friendly in terms of disposal of the container.

A specific example of the metal foil is aluminum foil, and the thickness of the aluminum foil is preferably 5 μm to 50 μm.
Examples of inorganic compounds that form the inorganic vapor deposition layer include metals, metal oxides, metal nitrides, and metal carbides.
Specific examples of metal elements constituting the above inorganic compounds include 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), and chromium (Cr).

In addition to these, indium tin oxide (ITO), chemical vapor deposition, etc.
Also included are composite inorganic compounds such as an O _x C _y film.

As the inorganic material to be vapor-deposited for use in the resin film having a vapor-deposited layer, silicon oxide and aluminum oxide are preferred.
The average composition of inorganic compounds is expressed as _MOx , _MOxCy (wherein M represents a metal element, and the values of x and _y vary depending on the metal element), such as _SiOx , _AlOx , _SiOxCy , _etc. In the case of metal oxides, the value of X can range, for example, from 0 to 2 for silicon, 0 to 1.5 for aluminum, 0 to 1 for magnesium, 0 to 1 for calcium, 0 to 0.5 for potassium, 0 to 2 for tin, 0 to 0.5 for sodium, 0 to 1.5 for boron, 0 to 2 for titanium, 0 to 1 for lead, 0 to 2 for zirconium, and 0 to 1.5 for yttrium.
In the above _MOx , when x=0, it is, for example, a metal, and the upper limit of the range of x is
This is the value when completely oxidized.

For packaging material applications, silicon oxide and aluminum oxide are preferably used, and it is preferable to use silicon oxide with x in the range of 1.0 to 2.0, and aluminum oxide with x in the range of 0.5 to 1.5.
The gas barrier layer may be formed of one of these barrier materials, or may be a combination of two or more of them, or may be a mixture of two or more of them. It may be composed of one layer or multiple layers of the same or different compositions, and in the case of multiple layers, they do not have to be laminated adjacently.

The resin film that supports the above-mentioned deposition layer can be a resin film that has excellent mechanical, physical, chemical, and other properties, and is particularly strong and tough, as well as heat-resistant, since the deposition layer is provided on it.

Specifically, in the present invention, examples of the resin film supporting the deposition layer include 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, acrylonitrile-styrene copolymers (AS resins), acrylonitrile-butadiene-styrene copolymers (ABS resins), polyolefin films such as polybutene resin films, polyvinyl chloride-based resins, polycarbonate-based resins, polyimide-based resins, polyamideimide-based resins, polyarylphthalate resins, silicone-based resins, polysulfone-based resins, polyphenylene sulfide-based resins, polyethersulfone-based resins, polyurethane-based resins, cellulose-based resins, poly(meth)acrylic resins, polyvinylidene chloride films, acetal-based resin films, fluorine-based resins, and others.
In the present invention, it is particularly preferable to use a film made of a polypropylene resin, a polyester resin, or a polyamide resin.

Methods for forming an inorganic vapor deposition layer include using the inorganic compounds described above as raw materials and forming a vapor deposition layer on a resin film using, for example, physical vapor deposition methods (Physical Vapor Deposition, PVD methods) such as vacuum deposition, sputtering, ion plating, cluster ion beam methods, etc., or chemical vapor deposition methods (Chemical Vapor Deposition, CVD methods) such as plasma chemical vapor deposition, thermal chemical vapor deposition, photochemical vapor deposition, etc.

More specifically, in the above-mentioned PVD method, for example, a take-up type deposition machine is used, and a resin film coming off a winding roll in a vacuum chamber is placed into a deposition chamber, where a deposition source heated in a crucible is evaporated, and if necessary, an inorganic deposition layer is formed through a mask on the resin film on a cooled coating drum while oxygen or the like is sprayed from an oxygen outlet, and then the resin film with the inorganic deposition layer formed thereon is wound up onto a take-up roll, thereby producing a resin film having an inorganic deposition layer according to the present invention.

On the other hand, in the above-mentioned CVD method, a mixed gas of, for example, an organic silicon 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 a resin film unwound from a winding roll arranged in a vapor deposition chamber, and onto the peripheral surface of an electrode drum in the vapor deposition chamber, whereby a resin film on which an inorganic vapor deposition layer of silicon oxide or the like is formed by plasma can be produced. In the present invention, the resin film having the above-mentioned inorganic vapor deposition layer prevents oxygen gas or water vapor from passing through, and functions as a gas barrier layer against these.

In the above, 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, in order to obtain sufficient barrier properties.
More specifically, in the above PVD method, the thickness of the vapor-deposited layer of aluminum oxide is preferably 30 Å to 1000 Å, and more preferably about 50 Å to 500 Å.
In the above CVD method, the thickness of the vapor-deposited layer of silicon oxide is preferably 30 Å to 3000 Å, and more preferably 50 Å to 2000 Å.
In the above, in the case of a vapor-deposited layer made of a metal oxide or an inorganic substance, if the thickness of the vapor-deposited layer exceeds the above range, cracks or the like are likely to occur in the vapor-deposited layer, and there is a risk that the barrier properties will be reduced due to warping, and there are problems such as high material costs, which are undesirable. Also, if the thickness is less than the above range, it is undesirable because it becomes difficult to exhibit the barrier properties.

Furthermore, the resin film having an inorganic vapor deposition layer has a water vapor permeability measured in accordance with JIS K7129 under an environment of a temperature of 40° C. and a humidity of 100% RH of preferably 3.0 g/ ^m2 ·day or less, more preferably 2.0 g/ ^m2 ·day or less, and even more preferably 1.5 g/ ^m2 ·day or less. If the water vapor permeability falls within the above numerical range, the intrusion of water vapor from the outside of the package into the content storage section inside the package can be sufficiently suppressed.
The resin film having an inorganic vapor deposition layer preferably has an acid permeability of 3.0 cc/ ^m2 or less when measured in accordance with JIS K7126 under an environment of a temperature of 23° C. and a humidity of 90% RH.
If the oxygen permeability satisfies ^the above numerical range, the intrusion of oxygen from the outside of the package into the content-accommodating section inside the package can ^be sufficiently suppressed.

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 aroma retention and the like.
Examples of the barrier resin that can be used include films or coatings of resins with excellent gas barrier properties, such as polyvinylidene chloride resins (PVDC), polyester resins, polyamide resins (particularly aromatic polyamides such as nylon MXD6), ethylene-vinyl alcohol copolymers (EVOH) having an ethylene content of 25 mol % to 50 mol % obtained by fully saponifying an ethylene-vinyl acetate copolymer (vinyl acetate is approximately 79 wt % to 92 wt %), polyvinyl alcohol, polyacrylonitrile, and the like.
The thickness of the barrier resin coating film or the barrier resin film is not limited, but is preferably 0.5 μm to 300 μm, and more preferably 1 μm to 100 μm.
As the gas barrier film, a metal foil or a resin film having a vapor deposition layer is preferred, and an aluminum foil is particularly preferred.

[Preparation of sulfur-based gas absorbing packaging material]
For example, a method for producing a sulfur-based gas absorbing laminate by laminating a substrate layer and a gas barrier layer on a sulfur-based gas absorbing sealant film will be described. The production method shown below is only one example and does not limit the present invention.
The lamination of the base material layer and the gas barrier layer can be carried out by any method commonly used in the production of packaging materials, such as a wet lamination method, a dry lamination method, a solventless dry lamination method, an extrusion lamination method, a T-die coextrusion molding method, a coextrusion lamination method, an inflation method, or the like.
For example, a substrate layer, a gas barrier layer, and a sulfur-based gas absorbing sealant film can be laminated and bonded via an adhesive layer laminated by an extrusion coating method, a dry lamination method, a non-solvent lamination method, or the like to obtain a sulfur-based gas absorbing laminate.

When laminating by the extrusion coating method, first, the resin composition that forms the adhesive layer is heated and melted, and then expanded and stretched in the required width direction using a T-die to be (co)extruded in a curtain shape. The molten resin is then caused to flow down onto the surface to be laminated and sandwiched between a rubber roll and a cooled metal roll, thereby simultaneously forming the adhesive layer and laminating and adhering to the surface to be laminated.
Alternatively, for example, first, a dry lamination adhesive is applied to one side of a resin film for the base layer, the film is dried, and the film is adhered and laminated to the barrier layer. Next, a dry lamination adhesive is applied to the surface of the barrier layer, the film is dried, and the film is adhered and laminated to the sulfur-based gas absorbing sealant film to obtain a sulfur-based gas absorbing laminate.
Then, an aging treatment may be carried out as necessary.
In this manner, a sulfur-containing gas absorbing laminate can be obtained.

<Sulfur-based gas absorbing all-solid-state lithium-ion battery packaging>
The sulfur-based gas-absorbing all-solid-state lithium-ion battery package of the present invention is a package produced by packaging an all-solid-state lithium-ion battery with the sulfur-based gas-absorbing packaging material of the present invention.
In the sulfur-based gas-absorbing all-solid-state lithium-ion battery packaging body, even if a gas to be absorbed is generated from the all-solid-state lithium-ion battery, the gas to be absorbed is absorbed by the sulfur-based gas-absorbing packaging material constituting the sulfur-based gas-absorbing all-solid-state lithium-ion battery packaging body, and therefore peeling or swelling is unlikely to occur in the sulfur-based gas-absorbing all-solid-state lithium-ion battery packaging body.

<Ingredients>
The main raw materials used in the examples of the present invention are as follows:

<Sulfur-based gas absorbent>
[Physical sulfur gas absorbent]
[Chemical sulfur gas absorbent]

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

[others]
Nylon film 1: Nylon film manufactured by Toyobo Co., Ltd., Harden Film NAP02, 25 μm thick PET film 1: Biaxially stretched PET film manufactured by Toyobo Co., Ltd., E5100, 12 μm thick.
Aluminum foil 1: Aluminum foil manufactured by Toyo Aluminum Co., Ltd., material 8021. Thickness: 40 μm.
DL adhesive 1: Dry laminating adhesive, RU-004/H-1, manufactured by Rock Paint Co., Ltd.
- EC adhesive 1: Admer NF528, acid-modified polyethylene manufactured by Mitsui Chemicals, Inc.
EC adhesive 2: Mitsui Chemicals, Inc. acid-modified polypropylene, Admer QF551,

<Preparation of Masterbatch>
[Preparation of Masterbatch 1]
LDPE1 and chemical absorbent 1, a sulfur-based gas chemical absorbent, were melt-blended in the following ratio to obtain master batch 1 (MB1).
LDPE 1 90 parts by weight Chemical absorbent 1 10 parts by weight

[Preparation of Masterbatches 2 to 22]
According to the formulations in Tables 1 and 2, melt blending was carried out in the same manner as for Masterbatch 1 to obtain Masterbatches 2 to 22 (MB2 to 22).

[Example 1]
The following raw materials were mixed by dry blending to obtain a resin composition for a sulfur-based gas absorbing layer.
MB1 50 parts by weight LLDPE1 50 parts by weight Next, nylon film 1 for the base layer and aluminum foil 1 for the gas barrier layer were dry laminated (drying temperature 70° C.) with DL adhesive 1 (coating amount 3.5 g/m ² ) interposed therebetween.
To prepare a laminated film of nylon film 1 (25 μm)/DL adhesive 1 (3.5 g/m ² )/aluminum foil 1 (40 μm).
Then, the EC adhesive 1 and the resin composition for the sulfur-based gas absorbing layer obtained above were co-extruded onto the aluminum foil 1 side of the laminated film obtained above, and a sulfur-based gas absorbing packaging material having the following layer structure was obtained by a co-extrusion lamination method. Then, various evaluations were performed.
Layer structure: Nylon film 1 (thickness 25 μm) / DL adhesive 1 (coating amount 3.0 g / m2) / aluminum foil 1 (thickness 40 μm) / EC adhesive 1 (thickness 15 μm) / sulfur-based gas absorbing layer (thickness 30 μm)

[Examples 2 to 26, Comparative Examples 3 and 4]
According to the description in Tables 3 to 8, a master batch is selected to prepare a resin composition for a sulfur-based gas absorbing layer.
Materials for each layer were selected, and the same procedure as in Example 1 was carried out to obtain a sulfur-based gas absorbing packaging material, which was then evaluated in the same manner.

[Comparative Example 1]
According to the description in Table 5, the same procedure as in Example 1 was repeated except that a heat seal layer made of LLDPE1 was formed in place of the sulfur-based gas absorbing layer to obtain a packaging material, which was similarly evaluated.

[Comparative Example 2]
According to the description in Table 5, the same procedure as in Example 1 was repeated, except that a heat seal layer made of PP1 was formed in place of the sulfur-based gas absorbing layer to obtain a packaging material, which was similarly evaluated.

<Summary of results>
The sulfur-based gas absorbing laminates of all the examples of the present invention exhibited good manufacturability, heat sealability, and reduction in sulfur-based gas concentration.
However, Comparative Example 1, which did not contain a sulfur-based gas absorbent, was inferior in the effect of reducing the sulfur-based gas concentration, and Comparative Example 2, which contained too much sulfur-based gas absorbent, was inferior in heat sealability.
In Comparative Examples 3 and 4, since the heat sealability was poor, the evaluation was discontinued and the sulfur-based gas concentration was not measured.

＜Evaluation＞

[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.
A: The laminate had no wrinkles, bumps, or peeling.
x: Wrinkles, bumps, or peeling were observed in the laminate.

[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 a bifurcated state.
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 described below, and the pass/fail judgment was made according to the pass/fail judgment criteria described below.
Heat sealing conditions Temperature: 160°C
Pressure: 1 kgf/ ^cm2
Time: 1 second Test conditions Test speed: 300 mm/min Load range: 50 N
Pass/fail criteria: ◯: 30N/15mm or more, passed.
×: Less than 30N/15mm, not acceptable.

[Sulfur gas concentration]
The laminate was cut into a piece of 20 x 20 cm, and 1000 ml of test gas adjusted to have hydrogen sulfide of 30 ppm and dimethyl sulfide of 50 ppm as sulfur-based gas components was placed in a gas sampling bag (SMART BAG PA series, manufactured by GL Sciences Inc.). After leaving the bag at 25°C for 48 hours, the concentrations of hydrogen sulfide and dimethyl sulfide were measured using a detector tube.

1 Sulfur-based gas absorbing packaging material 2 Base layer 3 Intermediate layer 4 Gas barrier layer 5 Sealant layer 6 Sulfur-based gas absorbing layer 7 Sulfur-based gas absorbent 8 Heat seal layer

Claims (5)

A sulfur-based gas absorbing packaging material for a sulfide-based inorganic solid electrolyte type all-solid-state lithium ion battery, which absorbs a sulfur-based gas, comprising:
The packaging material for all-solid-state lithium-ion batteries includes, in this order, a substrate layer made of a substrate film, an adhesive layer, a gas barrier layer made of a gas barrier film, and a sealant layer made of a sulfur-based gas absorbing sealant film;
The sulfur-based gas absorbing sealant film contains a sulfur-based gas absorbent and a heat-sealable resin,
The sulfur-based gas absorbent contains a sulfur-based gas chemical absorbent and/or a sulfur-based gas physical absorbent,
The sulfur-based gas chemical absorbent is a metal oxide and/or an inorganic material having a metal or metal ion supported thereon or mixed therein,
The metal species in the inorganic material carrying or containing the metal or metal ion includes one or more selected from the group consisting of Ca, Mg, Na, Cu, Ag, Pt, Au, Fe, Al, and Ni;
The sulfur-containing gas physical absorbent contains one or more selected from the group consisting of hydrophobic zeolite and bentonite having a SiO ₂ /Al ₂ O ₃ molar ratio of 30/1 to 2000/1,
The content of the sulfur-based gas absorbent in the layer containing the sulfur-based gas absorbent is 0.3 mass% or more and 30 mass% or less.
Sulfur-based gas absorbing packaging material. The sulfur-based gas absorbent has a maximum particle size of 20 μm or less and a number average particle size of 0.1 μm or more and 15 μm or less.
The sulfur-based gas absorbing packaging material according to claim 1 . The base film contains a polyamide resin and/or a polyester resin.
The sulfur-based gas absorbing packaging material according to claim 1 or 2. The gas barrier film is an aluminum foil.
The sulfur-based gas absorbing packaging material according to any one of claims 1 to 3. A sulfur-based gas absorbing all-solid-state lithium ion battery packaging body made from the sulfur-based gas absorbing packaging material according to any one of claims 1 to 4.

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