WO2020138059A1

WO2020138059A1 - Exterior material for power storage device, manufacturing method thereof, and power storage device

Info

Publication number: WO2020138059A1
Application number: PCT/JP2019/050568
Authority: WO
Inventors: 立沢　雅博; 純景山
Original assignee: 大日本印刷株式会社
Priority date: 2018-12-28
Filing date: 2019-12-24
Publication date: 2020-07-02
Also published as: JP6760550B1; JPWO2020138059A1

Abstract

Provided is an exterior material for a power storage device, which has an excellent ability to distinguish an identification mark printed on a surface in a yellow room, even when the exterior material has a black appearance. The exterior material for a power storage device having a black appearance is configured by a laminate including at least a base material layer, a barrier layer, and a thermally fusible resin layer in this order from the outside, wherein the laminate includes a layer containing a blue agent outside the barrier layer.

Description

Power storage device exterior material, manufacturing method thereof, and power storage device

The present disclosure relates to an exterior material for an electricity storage device, a method for manufacturing the same, and an electricity storage device.

Conventionally, various types of power storage devices have been developed, but in all power storage devices, an exterior material is an indispensable member for encapsulating power storage device elements such as electrodes and electrolytes. Conventionally, metal exterior materials have been widely used as exterior materials for power storage devices.

On the other hand, in recent years, as electric vehicles, hybrid electric vehicles, personal computers, cameras, mobile phones, etc. have become more sophisticated, power storage devices are required to have various shapes, and thin and lightweight. However, it has been difficult to follow the diversification of the shape with the metal exterior material for the electricity storage device, which has been widely used in the past, and there is a limitation in weight reduction.

Therefore, in recent years, as a packaging material for an electricity storage device that can be easily processed into various shapes and can be made thin and lightweight, a film-like material in which a base material layer/barrier layer/heat-fusible resin layer is sequentially laminated A laminated body has been proposed (for example, see Patent Document 1).

In such an electric storage device exterior material, generally, a recess is formed by cold forming, and an electric storage device element such as an electrode or an electrolytic solution is arranged in a space formed by the recess, and a heat-fusible resin is used. By heat-sealing the layers, an electricity storage device in which an electricity storage device element is housed inside the exterior material for an electricity storage device is obtained.

Japanese Patent Laid-Open No. 2008-287971 JP, 2005-166261, A

For example, an electricity storage device such as a lithium-ion secondary battery may be required to be colored black in order to unify the appearance and color of a device such as an electric device to be mounted (see Patent Document 2, for example. reference).

On the other hand, in the manufacturing process of an electricity storage device using the exterior material for an electricity storage device, an identification mark such as product information (for example, letters or numbers indicating a lot number, a bar code or a symbol) is displayed on the surface of the electricity storage device. May be printed. By attaching the identification mark to the surface of the electricity storage device, for example, a genuine product and a counterfeit product can be distinguished from each other. Similarly, an identification mark or the like may be printed on the outer surface in the manufacturing process of the exterior material for an electricity storage device.

However, as a result of studies by the inventors of the present disclosure, when the electricity storage device or the exterior material for an electricity storage device is colored so as to have a black appearance, the distinguishability of a printed identification mark or the like is deteriorated in the manufacturing process thereof or the like. A new challenge was found.

Specifically, in the manufacturing process of electricity storage devices and exterior materials for electricity storage devices, processing and inspection may be performed under a yellow light source such as in a yellow room. However, if an identification sign or the like is printed on the electricity storage device or the exterior material for an electricity storage device that appears black in color and processed or inspected under the yellow light source in the yellow room, the identification of the identification mark deteriorates, resulting in product information. It was found that there is a possibility that it is not possible to accurately read the above.

Under such circumstances, the present disclosure can identify the identification mark printed on the surface in the yellow room or under the light source of the orange to yellow lamp, even though it is the exterior material for the electricity storage device that exhibits a black appearance. The main object is to provide an exterior material for an electricity storage device having excellent properties.

The inventors of the present disclosure have made earnest studies to solve the above problems. As a result, in order from the outside, at least a base material layer, a barrier layer, and a heat-fusible resin layer, which is composed of a laminated body, in the exterior material for an electricity storage device having a black appearance, outside the barrier layer, By providing a layer containing a blue colorant, it is possible to adjust to a black color exhibiting a bluish hue, which is a complementary color of yellow, among other black colors, and it is possible to adjust the surface in the yellow room or under the light source of an orange to yellow lamp. It has been found that the distinguishability of the printed identification mark is enhanced.

The present disclosure has been completed by further studies based on these findings. That is, the present disclosure provides the inventions of the aspects described below.
An exterior material for an electricity storage device, which has a black appearance,
The exterior material for an electricity storage device is, in order from the outside, composed of a laminate including at least a base material layer, a barrier layer, and a heat-fusible resin layer,
The exterior body for an electricity storage device, wherein the laminated body includes a layer containing a blue colorant outside the barrier layer.

According to the present disclosure, the identification mark printed on the surface is identified in the yellow room or under the light source of the orange to yellow lamp (Na lamp) even though it is the exterior material for the electricity storage device that exhibits a black appearance. It is possible to provide an exterior material for an electricity storage device having excellent properties. Further, according to the present disclosure, it is also possible to provide a method for manufacturing the exterior material for an electricity storage device, and an electricity storage device using the exterior material for an electricity storage device.

FIG. 3 is a schematic diagram illustrating an example of a cross-sectional structure of a power storage device exterior material of the present disclosure. FIG. 3 is a schematic diagram illustrating an example of a cross-sectional structure of a power storage device exterior material of the present disclosure. FIG. 3 is a schematic diagram illustrating an example of a cross-sectional structure of a power storage device exterior material of the present disclosure. FIG. 3 is a schematic diagram illustrating an example of a cross-sectional structure of a power storage device exterior material of the present disclosure. FIG. 3 is a schematic diagram illustrating an example of a cross-sectional structure of a power storage device exterior material of the present disclosure. FIG. 3 is a schematic diagram illustrating an example of a cross-sectional structure of a power storage device exterior material of the present disclosure.

The exterior material for an electricity storage device of the present disclosure is an exterior material for an electricity storage device that exhibits a black appearance, and the exterior material for an electricity storage device is, in order from the outside, at least a base material layer, a barrier layer, and a heat-fusible resin. It is composed of a laminated body including layers, and is characterized in that a layer containing a blue colorant is provided outside the barrier layer. According to the exterior material for an electricity storage device of the present disclosure, by being provided with the configuration, the exterior material for an electricity storage device having a black appearance is printed on the surface under the light source in the yellow room. The excellent identification property of the identification mark can be exhibited.

Hereinafter, the exterior material for the electricity storage device of the present disclosure will be described in detail. In the present specification, the numerical range indicated by “to” means “greater than or equal to” and “less than or equal to”. For example, the expression 2 to 15 mm means 2 mm or more and 15 mm or less.

Further, in the exterior material for an electricity storage device of the present disclosure, “the appearance is black” means that the exterior material for an electricity storage device is recognized to be black when observed from the outside with the naked eye. .. More specifically, “black” in “the appearance is black” has an L ^* value of 40 or less, preferably 35 or less in CIE1976 L ^* a ^* b ^* (CIELAB) chromaticity coordinates. The L ^* value is also in the L ^* a ^* b ^* color space of the reflected light measured from the outside under the SCI method, the visual field of 10°, and the measurement conditions of the light source F2. In addition, in addition to the L ^* value, the a ^* value of black is preferably −20 to +20, and more preferably −10 to +10. The exterior material for an electricity storage device of the present disclosure is characterized in that it has a black appearance and further has b ^* of −0.20 or less.

Also, the inside of the yellow room means a room in which light with a wavelength of 500 nm or less including ultraviolet rays is cut, and the light is visually recognized as yellow in the room. The yellow room is generally provided for performing a photolithography process in which a photosensitive material is handled, for example, in a clean room of a semiconductor factory.

1. Laminated Structure and Physical Properties of Exterior Material for Energy Storage Device The exterior material 10 for an energy storage device of the present disclosure is, for example, as shown in FIG. 1, a base material layer 1, a barrier layer 3, and a heat-fusible resin layer 4 in order from the outside. It is comprised from the laminated body provided with. In the exterior material 10 for an electricity storage device, the base material layer 1 is the outermost layer side and the heat-fusible resin layer 4 is the innermost layer. When assembling a power storage device using the power storage device exterior material 10 and the power storage device element, the peripheral edges are heat-sealed with the heat-fusible resin layers 4 of the power storage device exterior material 10 facing each other. The electricity storage device element is housed in the space formed by. In the laminate constituting the exterior material 10 for an electricity storage device of the present disclosure, the barrier layer 3 is used as a standard, the heat-fusible resin layer 4 side is the inner side of the barrier layer 3, and the base material layer 1 side of the barrier layer 3 is the inner side. Outside.

As shown in, for example, FIG. 2 to FIG. 6, the exterior material 10 for an electricity storage device enhances the adhesiveness between the base material layer 1 and the barrier layer 3 (further, as will be described later, electricity storage is performed). The adhesive layer 2 may be provided as necessary for the purpose of, for example, coloring the device exterior material 10. Further, as shown in FIGS. 3 and 4, for example, a coloring layer 21 is provided between the base material layer 1 and the barrier layer 3 for the purpose of coloring the exterior material 10 for an electricity storage device. You may have. Further, as shown in FIG. 5 and FIG. 6, for example, the adhesive layer 5 may be provided between the barrier layer 3 and the heat-fusible resin layer 4 for the purpose of improving the adhesiveness between these layers. May have. Further, as shown in FIG. 6, a surface coating layer 6 and the like may be provided on the outside of the base material layer 1 (on the side opposite to the heat-fusible resin layer 4 side), if necessary.

The thickness of the laminate constituting the exterior material 10 for the electricity storage device is not particularly limited, but from the viewpoint of cost reduction, energy density improvement, etc., preferably about 180 μm or less, about 155 μm or less, about 120 μm or less. In addition, the thickness of the laminated body that constitutes the exterior material 10 for an electricity storage device is preferably about 35 μm or more, about 45 μm or more, about 5 μm or more from the viewpoint of maintaining the function of the exterior material for an electricity storage device that protects the electricity storage device element. The thickness is 60 μm or more. In addition, the preferable range of the thickness of the laminate constituting the exterior material 10 for an electricity storage device is, for example, about 35 to 180 μm, about 35 to 155 μm, about 35 to 120 μm, about 45 to 180 μm, about 45 to 155 μm, 45 to The thickness is about 120 μm, about 60 to 180 μm, about 60 to 155 μm, about 60 to 120 μm.

In the electricity storage device exterior material 10 of the present disclosure, the b ^* value in the L ^* a ^* b ^* color space of the reflected light measured from the outside under the SCI method, the visual field of 10°, and the measurement conditions of the light source F2 is −0. It is preferably less than or equal to 20. By setting the upper limit of the b ^* value to such a specific value, it is possible to adjust the exterior material for an electricity storage device having a black appearance to black having a bluish hue which is a complementary color of yellow. Therefore, in the yellow room or under the yellow light source, the excellent identification of the identification mark printed on the surface is exhibited.

The b ^* value is not particularly limited as long as it is −0.20 or less, but from the viewpoint that the distinctiveness is further improved and the appearance is black, it is preferably about -0.50 or less, more preferably about -0.80 or less. From the same viewpoint, the b ^* value is preferably about −5.00 or more, more preferably about −4.00 or more, further preferably about −2.00 or more, further preferably about −1.50 or more. Are listed. The preferable range of the b ^* value is about −5.00 to −0.20, about −5.00 to −0.50, about −5.00 to −0.80, and −4.00 to −0. About 20, about −4.00 to about −0.50, about −4.00 to −0.80, about −2.00 to −0.20, about −2.00 to −0.50, −2. Examples are about 00 to −0.80, about −1.50 to −0.20, about −1.50 to −0.50, and about −1.50 to −0.80. Among these, the b ^* value is particularly preferably about -1.50 to -0.80.

Further, the exterior material 10 for an electricity storage device of the present disclosure has an a ^* value in the L ^* a ^* b ^* color space of reflected light, which is measured from the outside under the measurement conditions of the SCI method, the field of view of 10°, and the light source F2. It is preferably +0.20 or less. Thereby, the distinctiveness is further improved, and it is suitably recognized that the appearance is black.

The a ^* value is more preferably about +0.10 or less, further preferably +0.04 or less, and further preferably from the viewpoint that the distinctiveness is further improved and that the appearance is suitably recognized as black. It is about +0.02 or less, more preferably about 0.00 or less, and further preferably about -0.01 or less. The a ^* value is preferably about −3.50 or more, more preferably about −3.00 or more, further preferably about −2.00 or more, further preferably about −0.50 or more, further preferably It is preferably about -0.30 or more, more preferably about -0.15 or more, still more preferably about -0.10 or more. Further, the preferable range of the a ^* value is about −3.50 to +0.20, −3.50 to +0.10, −3.50 to +0.04, −3.50 to +0.02. , -3.50 to 0.00, -3.50 to -0.01, -3.00 to +0.20, -3.00 to +0.10, -3.00 to +0.04 , -3.00 to +0.02, -3.00 to 0.00, -3.00 to -0.01, -2.00 to +0.20, -2.00 to +0. Approximately 10; -2.00 to +0.04; -2.00 to +0.02; -2.00 to 0.00; -2.00 to -0.01; -0.50 to +0 .20, -0.50 to +0.10, -0.50 to +0.04, -0.50 to +0.02, -0.50 to 0.00, -0.50 to- About 0.01, about -0.30 to +0.20, about -0.30 to +0.10, about -0.30 to +0.04, about -0.30 to +0.02, about -0.30 0.00, -0.30 to -0.01, -0.15 to +0.20, -0.15 to +0.10, -0.15 to +0.04, -0.15 To about +0.02, about −0.15 to about 0.00, about −0.15 to −0.01, about −0.10 to +0.20, about −0.10 to +0.10, −0. Examples thereof include about 10 to +0.04, about −0.10 to +0.02, about −0.10 to 0.00, and about −0.10 to −0.01. Among them, the a ^* value is preferably about −0.30 to −0.01, and about −0.10 to −0.01.

Further, the exterior material 10 for an electricity storage device of the present disclosure has an L ^* value in the L ^* a ^* b ^* color space of reflected light, which is measured from the outside, under the SCI method, the field of view of 10°, and the measurement conditions of the light source F2. It is preferably 35.0 or less. Thereby, the distinctiveness is further improved, and it is suitably recognized that the appearance is black.

The L ^* value is more preferably about 33.0 or less, more preferably about 30.0 or less, and further preferably from the viewpoint that the distinctiveness is further improved and that the appearance is preferably black. Is about 28.0 or less. Further, the L ^* value is preferably about 25.0 or more, more preferably about 26.0 or more. The preferable range of the L ^* value is about 25.0 to 35.0, about 25.0 to 33.0, about 25.0 to 30.0, about 25.0 to 28.0, and about 26.0. ˜35.0, 26.0 to 33.0, 26.0 to 30.0, 26.0 to 28.0. Among these, the L ^* value is particularly about 25.0 to 30.0, about 26.0 to 30.0, further about 26.0 to 29.0, and further about 26.0 to 28.0. Is preferred.

<Measurement of L ^* value, a ^* value and b ^* value>
In the present disclosure, the values of L ^* value, a ^* value and b ^* value are values measured by the following method. Regarding the exterior material for the electricity storage device, the observation condition of the spectrocolorimeter (for example, CM-700d manufactured by Konica Minolta) calibrated with a white calibration cap (for example, CM-A177: manufactured by Konica Minolta) is 10°, and the observation light source is F2. , CSI mode (JIS Z8722-2009), and the L ^* , a ^* , and b ^* of the outer (base material layer side) surface are measured at room temperature and normal humidity. For measurement, each sample is measured at three points, and the average value is used as the measured value.

In the exterior material for an electricity storage device of the present disclosure and the electricity storage device using the same, the identification mark to be printed includes, for example, letters or numbers displaying a lot number, a bar code or a symbol. In addition, the color of the ink used for printing the identification mark (that is, the color of the identification mark) is preferably white, because the exterior material for an electricity storage device of the present disclosure having a black appearance is excellent in identification.

2. Each layer forming the exterior material for a power storage device [base material layer 1]
In the present disclosure, the base material layer 1 is a layer provided for the purpose of exerting a function as a base material of the exterior material for an electricity storage device. The base material layer 1 is located on the outer layer side of the exterior material for an electricity storage device.

The material forming the base material layer 1 is not particularly limited as long as it has a function as a base material, that is, at least an insulating property. The base material layer 1 can be formed by using, for example, a resin, and the resin may contain an additive described below. For example, the tint (fine color tone) of the exterior material 10 for an electricity storage device can be adjusted by adding an additive or a colorant described later to the base material layer.

When the base material layer 1 is made of resin, the base material layer 1 may be, for example, a resin film made of resin, or may be formed by applying resin. The resin film may be an unstretched film or a stretched film. Examples of the stretched film include a uniaxially stretched film and a biaxially stretched film, and a biaxially stretched film is preferable. Examples of the stretching method for forming the biaxially stretched film include a sequential biaxial stretching method, an inflation method and a simultaneous biaxial stretching method. Examples of the method for applying the resin include a roll coating method, a gravure coating method and an extrusion coating method.

Examples of the resin forming the base material layer 1 include resins such as polyester, polyamide, polyolefin, epoxy resin, acrylic resin, fluororesin, polyurethane, silicon resin, and phenol resin, and modified products of these resins. The resin forming the base material layer 1 may be a copolymer of these resins or a modified product of the copolymer. Further, it may be a mixture of these resins.

Among these, the resin forming the base material layer 1 is preferably polyester or polyamide.

Specific examples of the polyester include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and copolyester. Examples of the copolyester include a copolyester having ethylene terephthalate as a main repeating unit. Specifically, a copolymer polyester (hereinafter abbreviated to polyethylene (terephthalate/isophthalate)) in which ethylene terephthalate is a main repeating unit and is polymerized with ethylene isophthalate, polyethylene (terephthalate/adipate), polyethylene (terephthalate/ Sodium sulfoisophthalate), polyethylene (terephthalate/sodium isophthalate), polyethylene (terephthalate/phenyl-dicarboxylate), polyethylene (terephthalate/decanedicarboxylate), and the like. These polyesters may be used alone or in combination of two or more.

Specific examples of polyamides include aliphatic polyamides such as nylon 6, nylon 66, nylon 610, nylon 12, nylon 46, and copolymers of nylon 6 and nylon 66; terephthalic acid and/or isophthalic acid. Hexamethylenediamine-isophthalic acid-terephthalic acid copolyamides such as nylon 6I, nylon 6T, nylon 6IT, nylon 6I6T (I represents isophthalic acid, T represents terephthalic acid) containing a constitutional unit derived therefrom, polyamide MXD6 (polymeta Polyamides containing aromatics such as silylene adipamide; alicyclic polyamides such as polyamide PACM6 (polybis(4-aminocyclohexyl)methane adipamide); further lactam components and isocyanate components such as 4,4′-diphenylmethane-diisocyanate Examples thereof include copolymerized polyamides, polyesteramide copolymers and polyetheresteramide copolymers that are copolymers of copolymerized polyamides and polyesters and polyalkylene ether glycols; and polyamides such as these copolymers. These polyamides may be used alone or in combination of two or more.

The base material layer 1 preferably contains at least one of a polyester film, a polyamide film, and a polyolefin film, and preferably contains at least one of a stretched polyester film, a stretched polyamide film, and a stretched polyolefin film, It is more preferable to include at least one of a stretched polyethylene terephthalate film, a stretched polybutylene terephthalate film, a stretched nylon film, and a stretched polypropylene film. A biaxially stretched polyethylene terephthalate film, a biaxially stretched polybutylene terephthalate film, a biaxially stretched nylon film. More preferably, at least one of the biaxially oriented polypropylene films is included.

The base material layer 1 may be a single layer or may be composed of two or more layers. When the base material layer 1 is composed of two or more layers, the base material layer 1 may be a laminate in which a resin film is laminated with an adhesive or the like, or a resin is coextruded into two or more layers. It may be a laminate of the above resin films. Further, the resin film laminate obtained by coextruding the resin into two or more layers may be the unstretched base material layer 1 or may be uniaxially or biaxially stretched to form the base material layer 1.

Specific examples of the laminate of two or more resin films in the base material layer 1 include a laminate of a polyester film and a nylon film, a laminate of two or more nylon films, a laminate of two or more polyester films. And the like, and preferably a laminate of a stretched nylon film and a stretched polyester film, a laminate of two or more stretched nylon films, and a laminate of two or more stretched polyester films. For example, when the base material layer 1 is a laminate of two resin films, a laminate of a polyester resin film and a polyester resin film, a laminate of a polyamide resin film and a polyamide resin film, or a laminate of a polyester resin film and a polyamide resin film. A laminated body is preferable, and a laminated body of a polyethylene terephthalate film and a polyethylene terephthalate film, a laminated body of a nylon film and a nylon film, or a laminated body of a polyethylene terephthalate film and a nylon film is more preferable. In addition, since the polyester resin is unlikely to discolor when an electrolytic solution adheres to the surface, when the base material layer 1 is a laminate of two or more resin films, the polyester resin film is It is preferably located in the outermost layer.

When the base material layer 1 is a laminate of two or more resin films, the two or more resin films may be laminated via an adhesive. Examples of preferable adhesives include the same adhesives as those exemplified for the adhesive layer 2 described later. The method for laminating the two or more resin films is not particularly limited, and known methods can be employed, and examples thereof include a dry laminating method, a sandwich laminating method, an extrusion laminating method, a thermal laminating method, and the like. A laminating method can be mentioned. When laminating by a dry laminating method, it is preferable to use a polyurethane adhesive as the adhesive. At this time, the thickness of the adhesive is, for example, about 2 to 5 μm. Further, an anchor coat layer may be formed on the resin film and laminated. The anchor coat layer may be the same as the adhesive exemplified in the adhesive layer 2 described later. At this time, the thickness of the anchor coat layer is, for example, about 0.01 to 1.0 μm.

Further, even if additives such as a lubricant, a flame retardant, an antiblocking agent, an antioxidant, a light stabilizer, a tackifier, and an antistatic agent are present on at least one of the surface and the inside of the base material layer 1. Good. As the additive, only one kind may be used, or two or more kinds may be mixed and used.

In the present disclosure, it is preferable that a lubricant is present on the surface of the base material layer 1 from the viewpoint of enhancing the moldability of the exterior material for an electricity storage device. The lubricant is not particularly limited, but preferably an amide lubricant is used. Specific examples of the amide-based lubricant include saturated fatty acid amide, unsaturated fatty acid amide, substituted amide, methylolamide, saturated fatty acid bisamide, unsaturated fatty acid bisamide, fatty acid ester amide, aromatic bisamide, and the like. Specific examples of the saturated fatty acid amide include lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, and hydroxystearic acid amide. Specific examples of unsaturated fatty acid amides include oleic acid amide and erucic acid amide. Specific examples of the substituted amide include N-oleylpalmitic acid amide, N-stearyl stearic acid amide, N-stearyl oleic acid amide, N-oleyl stearic acid amide, and N-stearyl erucic acid amide. Specific examples of the methylolamide include methylolstearic acid amide. Specific examples of the saturated fatty acid bisamide include methylenebisstearic acid amide, ethylenebiscapric acid amide, ethylenebislauric acid amide, ethylenebisstearic acid amide, ethylenebishydroxystearic acid amide, ethylenebisbehenic acid amide, and hexamethylenebisstearic acid amide. Examples thereof include acid amide, hexamethylene bisbehenic acid amide, hexamethylene hydroxystearic acid amide, N,N′-distearyl adipic acid amide and N,N′-distearyl sebacic acid amide. Specific examples of the unsaturated fatty acid bisamide include ethylenebisoleic acid amide, ethylenebiserucic acid amide, hexamethylenebisoleic acid amide, N,N′-dioleyl adipate amide, N,N′-dioleyl sebacic acid amide. And so on. Specific examples of the fatty acid ester amide include stearoamide ethyl stearate. Further, specific examples of the aromatic bisamide include m-xylylenebisstearic acid amide, m-xylylenebishydroxystearic acid amide, N,N'-distearylisophthalic acid amide and the like. The lubricant may be used alone or in combination of two or more.

When a lubricant is present on the surface of the base material layer 1, its amount is not particularly limited, but is preferably about 3 mg/m ² or more, more preferably about 4 to 15 mg/m ² , and further preferably 5 to 14 mg. /M ² can be mentioned.

The lubricant present on the surface of the base material layer 1 may be one in which the lubricant contained in the resin forming the base material layer 1 is exuded, or the one coated with the lubricant on the surface of the base material layer 1. May be.

The thickness of the base material layer 1 is not particularly limited as long as it exerts a function as a base material, but is, for example, about 3 to 50 μm, preferably about 10 to 35 μm. When the base material layer 1 is a laminate of two or more resin films, the thickness of the resin film forming each layer is preferably about 2 to 25 μm.

For example, when the adhesive layer is a layer colored in black, the base material layer located outside the adhesive layer is preferably transparent or translucent.

[Adhesive layer 2]
In the exterior material for an electricity storage device of the present disclosure, the adhesive layer 2 is a layer provided between the base material layer 1 and the barrier layer 3, if necessary, for the purpose of enhancing the adhesiveness between the base material layer 1 and the barrier layer 3.

In the exterior material for an electricity storage device of the present disclosure, the adhesive layer 2 can be a layer that is located outside the barrier layer 3 and that contains a blue agent. For example, by coloring the adhesive layer 2 in black to form an exterior material for an electricity storage device having a black appearance, and further adding a blue agent described below to the adhesive layer 2 to provide the above-mentioned distinguishability. Can be increased. From the viewpoint of enhancing the above-mentioned distinctiveness, the composition such as the kind and content of the colorant contained in the adhesive layer 2 and the base material layer 1 are further provided after the blue agent is blended. By adjusting the composition of layers such as the surface coating layer 6 and the colored layer 21 located outside the barrier layer 3, and further adjusting the aging treatment conditions of the electricity storage device exterior material described later, the electricity storage device exterior material 10 can be adjusted. The color of can be adjusted.

The adhesive layer 2 is formed of an adhesive that can bond the base material layer 1 and the barrier layer 3 together. The adhesive used for forming the adhesive layer 2 is not limited, but may be any of a chemical reaction type, a solvent volatilization type, a heat melting type, a heat pressure type and the like. Further, it may be a two-component curing type adhesive (two-component adhesive), a one-component curing type adhesive (one-component adhesive), or a resin that does not undergo a curing reaction. The adhesive layer 2 may be a single layer or a multilayer.

Specific examples of the adhesive component contained in the adhesive include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, polyesters such as copolyester; polyether; polyurethane; epoxy resin; Phenolic resin; nylon 6, nylon 66, nylon 12, polyamide such as copolyamide; polyolefin resin such as polyolefin, cyclic polyolefin, acid-modified polyolefin, acid-modified cyclic polyolefin; polyvinyl acetate; cellulose; (meth)acrylic resin; Polyimide; polycarbonate; amino resins such as urea resin and melamine resin; rubber such as chloroprene rubber, nitrile rubber and styrene-butadiene rubber; silicone resin and the like. These adhesive components may be used alone or in combination of two or more. Among these adhesive components, a polyurethane adhesive is preferable. In addition, the resin serving as the adhesive component may be used in combination with an appropriate curing agent to enhance the adhesive strength. The curing agent is appropriately selected from polyisocyanates, polyfunctional epoxy resins, oxazoline group-containing polymers, polyamine resins, acid anhydrides, etc. depending on the functional groups of the adhesive component.

The polyurethane adhesive includes, for example, a polyurethane adhesive containing a base compound containing a polyol compound and a curing agent containing an isocyanate compound. A two-component curing type polyurethane adhesive containing a polyol such as a polyester polyol, a polyether polyol and an acrylic polyol as a main component and an aromatic or aliphatic polyisocyanate as a curing agent is preferable. Further, as the polyol compound, it is preferable to use a polyester polyol having a hydroxyl group at the side chain in addition to the hydroxyl group at the terminal of the repeating unit. Examples of the curing agent include aliphatic, alicyclic, aromatic and araliphatic isocyanate compounds. Examples of the isocyanate-based compound include hexamethylene diisocyanate (HDI) xylylene diisocyanate (XDI), isophorone diisocyanate (IPDI), hydrogenated XDI (H6XDI), hydrogenated MDI (H12MDI), tolylene diisocyanate (TDI), diphenylmethane diisocyanate ( MDI), naphthalene diisocyanate (NDI) and the like. Moreover, the polyfunctional isocyanate modified body etc. from 1 type or 2 types or more of these diisocyanates are mentioned. Further, a multimer (for example, trimer) can be used as the polyisocyanate compound. Examples of such a multimer include an adduct body, a biuret body, and a nurate body. The aliphatic isocyanate-based compound refers to an isocyanate having an aliphatic group and no aromatic ring, the alicyclic isocyanate-based compound refers to an isocyanate having an alicyclic hydrocarbon group, an aromatic isocyanate-based compound Means an isocyanate having an aromatic ring. Since the adhesive layer 2 is formed of the polyurethane adhesive, excellent resistance to the electrolytic solution is imparted to the exterior material for the electricity storage device, and the base layer 1 is prevented from peeling off even when the electrolytic solution adheres to the side surface. ..

Further, the adhesive layer 2 may contain other components as long as it does not impair the adhesiveness, and may contain a colorant, a thermoplastic elastomer, a tackifier, a filler and the like. Since the adhesive layer 2 contains the coloring agent, the exterior material for the electricity storage device can be colored. Known colorants such as pigments and dyes can be used as the colorant. In addition, as the colorant, only one kind may be used, or two or more kinds may be mixed and used.

The type of pigment is not particularly limited as long as the b ^* value is −0.20 or less and the adhesiveness of the adhesive layer 2 is not impaired. Examples of organic pigments include azo-based, phthalocyanine-based, quinacridone-based, anthraquinone-based, dioxazine-based, indigothioindigo-based, perinone-perylene-based, isoindolenin-based, benzimidazolone-based pigments, etc. Examples of the pigment include carbon black-based, titanium-based, titanium oxide-based, cadmium-based, lead-based, chromium oxide-based, and iron-based pigments, and in addition, mica (mica) fine powder, fish scale foil, and the like. To be

The average particle diameter of the pigment is not particularly limited and may be, for example, about 0.05 to 5 μm, preferably about 0.08 to 2 μm. The average particle diameter of the pigment is the median diameter measured by a laser diffraction/scattering type particle diameter distribution measuring device. When the primary particle diameter of the pigment changes, the tint changes even for the same type of pigment. For example, when the primary particle diameter of the black pigment becomes large, it may become slightly bluish black. Therefore, in the present disclosure, it is also preferable to adjust the primary particle diameter of the pigment used. The secondary particle size of the pigment is preferably about 0.8 μm or less, more preferably about 0.6 μm or less, still more preferably about 0.4 μm or less. The secondary particle size of the pigment is preferably about 0.05 μm or more, more preferably about 0.1 μm or more. Preferable ranges of the secondary particle diameter of the pigment are about 0.05 to 0.8 μm, about 0.05 to 0.6 μm, about 0.05 to 0.4 μm, about 0.1 to 0.8 μm, and 0.1. The thickness is about 1 to 0.6 μm and about 0.1 to 0.4 μm.

Among the colorants, it is preferable to use a black colorant in order to make the exterior material of the electricity storage device have a black appearance. The black colorant is a black colorant, which is an additive such as a pigment or dye that can be colored black. Examples of the blackening agent include black pigments. As the black pigment, carbon and titanium pigments are preferable. The black pigment made of carbon is generally called carbon black. Titanium black is preferable as the titanium-based pigment. Further, carbon black and titanium black may be mixed and used.

Further, from the viewpoint of improving the distinctiveness after the appearance of the exterior material for the electricity storage device is black, it is preferable that the adhesive layer 2 further contains a blue agent in addition to the black agent. The blue colorant is a blue colorant, which is an additive such as a pigment or dye that can be colored blue. Examples of the blue agent include dyes such as anthraquinone and indigoid, phthalocyanine, ultramarine, ferric ferrocyanide, and pigments such as navy blue.Examples of the phthalocyanine include copper phthalocyanine and metal-free phthalocyanine, and copper phthalocyanine is preferable. Is. Copper phthalocyanine is known as a blue pigment.

It is preferable that Cu element is detected when an analysis by a fluorescent X-ray analysis method (XRF) is performed from the outside of the laminate that constitutes the exterior material for the electricity storage device of the present disclosure. For example, when a pigment containing copper (for example, copper phthalocyanine) or the like is included as the pigment of the adhesive layer 2 of the exterior material for an electricity storage device, when an analysis by fluorescent X-ray analysis (XRF) is performed from the outside of the laminate, Cu element is detected. As described later, even when the surface coating layer 6 and the colored layer 21 include a pigment containing copper (for example, copper phthalocyanine) and the like, when the analysis by the fluorescent X-ray analysis method (XRF) is performed from the outside, the Cu element is To be detected. The detection conditions described in the examples can be adopted for the detection of the Cu element by the fluorescent X-ray analysis method (XRF).

The content of the colorant in the adhesive layer 2 is not particularly limited as long as the exterior material for an electricity storage device is colored black, and from the viewpoint of appropriate coloring, it is preferably about 0.5 mass% or more, more preferably about It is 1.0 mass% or more. The content of the colorant in the adhesive layer 2 is preferably about 50.0% by mass or less, more preferably about 30.%, from the viewpoint of appropriately maintaining the adhesiveness between the base material layer 1 and the barrier layer 3. It is 0 mass% or less, more preferably 20.0 mass% or less. The preferable range of the content of the colorant in the adhesive layer 2 is about 0.5 to 50.0% by mass, about 0.5 to 30.0% by mass, about 0.5 to 20.0% by mass, 1 It is about 0.0 to 50.0% by mass, about 1.0 to 30.0% by mass, and about 1.0 to 20.0% by mass.

In addition, when a black agent is mixed as a coloring agent in the adhesive layer 2, the content of the black agent in the adhesive layer 2 is not particularly limited as long as the exterior material for an electricity storage device is colored in black, and is appropriately colored. From the viewpoint, it is preferably about 0.5% by mass or more, more preferably about 1.0% by mass or more. Further, from the viewpoint of appropriately maintaining the adhesiveness between the base material layer 1 and the barrier layer 3, the content of the black agent is preferably about 50.0 mass% or less, more preferably about 30.0 mass% or less. , And more preferably 20.0% by mass or less. The preferred range of the blackening agent is about 0.5 to 50.0% by mass, about 0.5 to 30.0% by mass, about 0.5 to 20.0% by mass, 1.0 to 50. Examples thereof include about 0% by mass, about 1.0 to 30.0% by mass, and about 1.0 to 20.0% by mass. When a blue agent is blended in the adhesive layer 2, the content of the blue agent in the adhesive layer 2 is not particularly limited as long as the exterior material for the electricity storage device is colored black, and is, for example, 0.5 to 30. The amount is about mass%, preferably 1 to 20 mass%.

When a black agent and a blue agent are mixed in the adhesive layer 2, the ratio of the black agent and the blue agent in the adhesive layer 2 is 100 parts by mass of the black agent, and the ratio of the blue agent is preferably about 0. 0.1 mass part or more, more preferably about 1 mass part or more, still more preferably about 10 mass part or more. The ratio of the blue colorant is preferably about 150 parts by mass or less, more preferably about 100 parts by mass or less. The preferred range of the ratio of the blue agent is about 0.1 to 150 parts by mass, about 0.1 to 100 parts by mass, about 1 to 150 parts by mass, about 1 to 100 parts by mass, and about 10 to 150 parts by mass. 10 to 100 parts by mass.

The thickness of the adhesive layer 2 is not particularly limited as long as the base material layer 1 and the barrier layer 3 can be bonded, but is, for example, about 1 μm or more, about 2 μm or more. The thickness of the adhesive layer 2 is, for example, about 10 μm or less and about 5 μm or less. The preferable range of the thickness of the adhesive layer 2 is about 1 to 10 μm, about 1 to 5 μm, about 2 to 10 μm, and about 2 to 5 μm.

[Coloring layer 21]
The colored layer 21 is a layer provided between the base material layer 1 and the barrier layer 3 as needed. When the adhesive layer 2 is provided, the coloring layer 21 may be provided on at least one of the base material layer 1 and the adhesive layer 2 and the adhesive layer 2 and the barrier layer 3. Further, the colored layer 21 may be provided outside the base material layer 1. By providing the colored layer 21, the exterior material for an electricity storage device can be suitably colored black.

In the exterior material for an electricity storage device of the present disclosure, the colored layer 21 may be a layer that is located outside the barrier layer 3 and that includes a blue colorant. For example, the colored layer 21 is colored black to form an exterior material for an electricity storage device having a black appearance, and a blue agent is added to the colored layer 21 to adjust the tint of the exterior material 10 for an electricity storage device. Then, the above-mentioned distinctiveness can be improved. From the viewpoint of enhancing the distinctiveness, a blue agent is added to the coloring layer 21, and then the composition such as the type and content of the coloring agent contained in the coloring layer 21, the base material layer 1, and the like are provided as necessary. By adjusting the composition of the layer located outside the barrier layer 3 such as the adhesive layer 2 and the surface coating layer 6 to be used, and further adjusting the aging conditions of the exterior material for the electricity storage device described later, the electricity storage device exterior The color of the material 10 can be adjusted.

The colored layer 21 can be formed, for example, by applying an ink containing a colorant to the surface of the base material layer 1 or the surface of the barrier layer 3. Known colorants such as pigments and dyes can be used as the colorant. In addition, as the colorant, only one kind may be used, or two or more kinds may be mixed and used.

Specific examples of the coloring agent contained in the coloring layer 21 are the same as those exemplified in the section of [Adhesive layer 2].

The content of the colorant in the colored layer 21 is not particularly limited as long as the exterior material for an electricity storage device is colored black, and from the viewpoint of appropriate coloring, preferably about 0.5% by mass or more, more preferably about 1% by mass. It is 0.0% by mass or more. The content of the colorant in the colored layer 21 is preferably about 50.0% by mass or less, more preferably about 30.0% by mass or less, and further preferably 20.% from the viewpoint of appropriately forming the colored layer 21. It is 0 mass% or less. The preferable range of the content of the colorant in the colored layer 21 is about 0.5 to 50.0% by mass, about 0.5 to 30.0% by mass, about 0.5 to 20.0% by mass, and 1. It may be about 0 to 50.0% by mass, 1.0 to 30.0% by mass, or 1.0 to 20.0% by mass.

When a black agent is added to the colored layer 21, the content of the black agent in the colored layer 21 is not particularly limited as long as the exterior material for an electricity storage device is colored black, and is preferably colored from the viewpoint of appropriate coloring. It is about 0.5% by mass or more, more preferably about 1.0% by mass or more. The content of the blackening agent in the colored layer 21 is preferably about 50.0% by mass or less, more preferably about 30.0% by mass or less, and further preferably 20.% from the viewpoint of appropriately forming the colored layer 21. It is 0 mass% or less. Further, the preferable range of the content of the black agent in the colored layer 21 is about 0.5 to 50.0% by mass, about 0.5 to 30.0% by mass, about 0.5 to 20.0% by mass, Examples thereof include about 1.0 to 50.0% by mass, about 1.0 to 30.0% by mass, and about 1.0 to 20.0% by mass. When a blue agent is added to the colored layer 21, the content of the blue agent in the colored layer 21 is not particularly limited as long as the exterior material for the electricity storage device is colored black, and is, for example, 0.5 to 30% by mass. The amount is preferably about 1 to 20% by mass.

When a black agent and a blue agent are blended in the colored layer 21, the ratio of the black agent and the blue agent in the colored layer 21 is preferably about 0.1 with the black agent being 100 parts by mass. The amount is at least mass, more preferably at least about 1 part by mass, further preferably at least about 10 parts by mass. The ratio of the blue colorant is preferably about 150 parts by mass or less, more preferably about 100 parts by mass or less. The preferred range of the blue colorant is about 0.1 to 150 parts by mass, about 0.1 to 100 parts by mass, about 1 to 150 parts by mass, about 1 to 100 parts by mass, about 10 to 150 parts by mass, about 10 to It is about 100 parts by mass.

[Barrier layer 3]
In the exterior material for an electricity storage device, the barrier layer 3 is a layer that suppresses at least moisture from entering.

Examples of the barrier layer 3 include a metal foil having a barrier property, a vapor deposition film, a resin layer, and the like. The vapor deposition film may be a metal vapor deposition film, an inorganic oxide vapor deposition film, a carbon-containing inorganic oxide vapor deposition film, or the like, and the resin layer may be polyvinylidene chloride, polymers containing tetrachloroethylene (CTFE) as a main component or tetra- Examples thereof include polymers containing fluoroethylene (TFE) as a main component, polymers having a fluoroalkyl group, and fluorine-containing resins such as polymers having a fluoroalkyl unit as a main component, and ethylene vinyl alcohol copolymers. Further, as the barrier layer 3, a resin film provided with at least one of the vapor deposition film and the resin layer may be used. A plurality of barrier layers 3 may be provided. The barrier layer 3 preferably includes a layer made of a metal material. Specific examples of the metal material forming the barrier layer 3 include aluminum alloys, stainless steels, titanium steels, and steel plates. When used as metal foils, at least one of aluminum alloy foils and stainless steel foils is included. It is preferable.

The aluminum alloy foil is, from the viewpoint of improving the formability of the exterior material for an electricity storage device, more preferably a soft aluminum alloy foil composed of, for example, an annealed aluminum alloy, and the viewpoint of further improving the formability. Therefore, the aluminum alloy foil containing iron is preferable. In the aluminum alloy foil containing iron (100 mass %), the content of iron is preferably 0.1 to 9.0 mass %, and more preferably 0.5 to 2.0 mass %. When the content of iron is 0.1% by mass or more, it is possible to obtain the outer casing material for an electricity storage device having more excellent moldability. When the iron content is 9.0 mass% or less, a more flexible outer packaging material for an electricity storage device can be obtained. As the soft aluminum alloy foil, for example, an aluminum alloy having a composition specified by JIS H4160:1994 A8021H-O, JIS H4160:1994 A8079H-O, JIS H4000:2014 A8021P-O, or JIS H4000:2014 A8079P-O. Foil can be mentioned. If necessary, silicon, magnesium, copper, manganese, etc. may be added. The softening can be performed by annealing treatment or the like.

Also, examples of the stainless steel foil include austenite-based, ferrite-based, austenite-ferrite-based, martensite-based, and precipitation hardening-based stainless steel foils. Further, from the viewpoint of providing an exterior material for an electricity storage device having excellent moldability, the stainless steel foil is preferably made of austenitic stainless steel.

SUS304, SUS301, SUS316L and the like are specific examples of the austenitic stainless steel forming the stainless steel foil, and among these, SUS304 is particularly preferable.

In the case of a metal foil, the thickness of the barrier layer 3 may at least exhibit a function as a barrier layer that suppresses the infiltration of moisture, and is, for example, about 9 to 200 μm. The thickness of the barrier layer 3 is preferably about 85 μm or less, more preferably about 50 μm or less, further preferably about 40 μm or less, and particularly preferably about 35 μm or less. The thickness of the barrier layer 3 is preferably about 10 μm or more, more preferably about 20 μm or more, and even more preferably about 25 μm or more. The preferred range of the thickness is about 10-85 μm, about 10-50 μm, about 10-40 μm, about 10-35 μm, about 20-85 μm, about 20-50 μm, about 20-40 μm, about 20-35 μm, about 25- Examples include about 85 μm, about 25 to 50 μm, about 25 to 40 μm, and about 25 to 35 μm. When the barrier layer 3 is made of an aluminum alloy foil, the above range is particularly preferable. Further, particularly when the barrier layer 3 is made of stainless steel foil, the thickness of the stainless steel foil is preferably about 60 μm or less, more preferably about 50 μm or less, further preferably about 40 μm or less, and further preferably about The thickness is 30 μm or less, particularly preferably about 25 μm or less. The thickness of the stainless steel foil is preferably about 10 μm or more, more preferably about 15 μm or more. The preferred thickness range of the stainless steel foil is about 10 to 60 μm, about 10 to 50 μm, about 10 to 40 μm, about 10 to 30 μm, about 10 to 25 μm, about 15 to 60 μm, about 15 to 50 μm, The thickness is about 15 to 40 μm, about 15 to 30 μm, about 15 to 25 μm.

Also, when the barrier layer 3 is a metal foil, it is preferable to provide a corrosion-resistant film on at least the surface opposite to the base material layer in order to prevent dissolution and corrosion. The barrier layer 3 may have a corrosion resistant film on both sides. Here, the corrosion-resistant coating means, for example, hydrothermal conversion treatment such as boehmite treatment, chemical conversion treatment, anodic oxidation treatment, plating treatment with nickel or chromium, and corrosion prevention treatment for coating a coating agent on the surface of the barrier layer. And a barrier layer having corrosion resistance. As the treatment for forming the corrosion resistant film, one type may be performed, or two or more types may be combined. Further, not only one layer but also multiple layers can be formed. Further, among these treatments, the hydrothermal conversion treatment and the anodic oxidation treatment are treatments for dissolving the metal foil surface with a treatment agent to form a metal compound having excellent corrosion resistance. Note that these processes may be included in the definition of the chemical conversion process. In addition, when the barrier layer 3 has a corrosion resistant film, the barrier layer 3 includes the corrosion resistant film.

The corrosion-resistant coating is used to prevent delamination between the barrier layer (for example, aluminum alloy foil) and the base material layer during the formation of the exterior material for the electricity storage device, and by hydrogen fluoride generated by the reaction between the electrolyte and water. , Dissolution and corrosion of the surface of the barrier layer, especially when the barrier layer is an aluminum alloy foil, prevents the aluminum oxide present on the surface of the barrier layer from being dissolved and corroded, and the adhesiveness (wettability) of the surface of the barrier layer And the effect of preventing delamination between the base material layer and the barrier layer during heat sealing and preventing delamination between the base material layer and the barrier layer during molding.

Various types of corrosion-resistant films formed by chemical conversion treatment are known, and are mainly at least one of phosphates, chromates, fluorides, triazine thiol compounds, and rare earth oxides. And a corrosion-resistant film containing Examples of the chemical conversion treatment using a phosphate or chromate include chromate chromate treatment, chromate phosphoric acid treatment, phosphoric acid-chromate treatment, chromate treatment, and the like. Examples of the compound include chromium nitrate, chromium fluoride, chromium sulfate, chromium acetate, chromium oxalate, chromium biphosphate, acetyl acetate chromate, chromium chloride, potassium chromium sulfate, and the like. Examples of the phosphorus compound used for these treatments include sodium phosphate, potassium phosphate, ammonium phosphate, polyphosphoric acid and the like. Examples of the chromate treatment include etching chromate treatment, electrolytic chromate treatment, and coating chromate treatment, and coating chromate treatment is preferable. In this coating type chromate treatment, at least the surface of the barrier layer (for example, aluminum alloy foil) on the inner layer side is first subjected to a well-known method such as an alkali dipping method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method, and an acid activation method. A degreasing treatment is performed by a treatment method, and then a phosphate metal such as Cr (chromium) phosphate, Ti (titanium) phosphate, Zr (zirconium) phosphate, Zn (zinc) phosphate, etc. is applied to the degreased surface. A treatment liquid containing a salt and a mixture of these metal salts as a main component, or a treatment liquid containing a phosphoric acid non-metal salt and a mixture of these non-metal salts as a main component, or a combination thereof with a synthetic resin or the like. This is a treatment in which a treatment liquid composed of a mixture is applied by a well-known coating method such as a roll coating method, a gravure printing method, and a dipping method, and then dried. As the treatment liquid, various solvents such as water, alcohol solvents, hydrocarbon solvents, ketone solvents, ester solvents, ether solvents can be used, and water is preferable. Examples of the resin component used at this time include polymers such as phenolic resins and acrylic resins, and aminated phenolic polymers having repeating units represented by the following general formulas (1) to (4) are used. Examples include the chromate treatment used. In the aminated phenol polymer, the repeating units represented by the following general formulas (1) to (4) may be contained alone or in any combination of two or more. Good. The acrylic resin should be polyacrylic acid, acrylic acid methacrylic acid ester copolymer, acrylic acid maleic acid copolymer, acrylic acid styrene copolymer, or derivatives of these sodium salts, ammonium salts, amine salts, etc. Is preferred. Particularly, a derivative of polyacrylic acid such as ammonium salt, sodium salt, or amine salt of polyacrylic acid is preferable. In the present disclosure, polyacrylic acid means a polymer of acrylic acid. Further, the acrylic resin is also preferably a copolymer of acrylic acid and a dicarboxylic acid or a dicarboxylic acid anhydride, an ammonium salt of the copolymer of acrylic acid and a dicarboxylic acid or a dicarboxylic acid anhydride, a sodium salt, Alternatively, it is also preferably an amine salt. Only one type of acrylic resin may be used, or two or more types may be mixed and used.

In formulas (1) to (4), X represents a hydrogen atom, a hydroxy group, an alkyl group, a hydroxyalkyl group, an allyl group or a benzyl group. R ¹ and R ² are the same or different and each represents a hydroxy group, an alkyl group, or a hydroxyalkyl group. In the general formulas (1) to (4), examples of the alkyl group represented by X, R ¹ and R ² include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, Examples thereof include linear or branched alkyl groups having 1 to 4 carbon atoms such as tert-butyl group. Examples of the hydroxyalkyl group represented by X, R ¹ and R ² include, for example, hydroxymethyl group, 1-hydroxyethyl group, 2-hydroxyethyl group, 1-hydroxypropyl group, 2-hydroxypropyl group and 3-hydroxygroup. Linear or branched chain having 1 to 4 carbon atoms, which is substituted with one hydroxy group such as hydroxypropyl group, 1-hydroxybutyl group, 2-hydroxybutyl group, 3-hydroxybutyl group, 4-hydroxybutyl group An alkyl group is mentioned. In the general formulas (1) to (4), the alkyl group and the hydroxyalkyl group represented by X, R ¹ and R ² may be the same or different. In the general formulas (1) to (4), X is preferably a hydrogen atom, a hydroxy group or a hydroxyalkyl group. The number average molecular weight of the aminated phenol polymer having the repeating units represented by the general formulas (1) to (4) is, for example, preferably about 500 to 1,000,000, and more preferably about 1,000 to 20,000. More preferable. The aminated phenol polymer is produced by, for example, polycondensing a phenol compound or a naphthol compound with formaldehyde to produce a polymer having a repeating unit represented by the general formula (1) or (3), and then formaldehyde. And an amine (R ¹ R ² NH) to introduce a functional group (—CH ₂ NR ¹ R ² ) into the polymer obtained above. The aminated phenol polymer is used alone or in combination of two or more.

Another example of the corrosion resistant film is formed by a coating type corrosion prevention treatment in which a coating agent containing at least one selected from the group consisting of rare earth element oxide sols, anionic polymers and cationic polymers is applied. A thin film is used. The coating agent may further contain phosphoric acid or phosphate, and a cross-linking agent that cross-links the polymer. In the rare earth element oxide sol, fine particles of rare earth element oxide (for example, particles having an average particle diameter of 100 nm or less) are dispersed in a liquid dispersion medium. Examples of the rare earth element oxide include cerium oxide, yttrium oxide, neodymium oxide, and lanthanum oxide, and cerium oxide is preferable from the viewpoint of further improving the adhesion. The rare earth element oxides contained in the corrosion resistant film may be used alone or in combination of two or more. As the liquid dispersion medium of the rare earth element oxide sol, various solvents such as water, alcohol solvents, hydrocarbon solvents, ketone solvents, ester solvents, ether solvents can be used, and water is preferable. Examples of the cationic polymer include polyethyleneimine, an ionic polymer complex composed of a polymer having polyethyleneimine and a carboxylic acid, a primary amine-grafted acrylic resin obtained by graft-polymerizing a primary amine on an acrylic main skeleton, polyallylamine or a derivative thereof. , Aminated phenol and the like are preferable. The anionic polymer is preferably poly(meth)acrylic acid or a salt thereof, or a copolymer containing (meth)acrylic acid or a salt thereof as a main component. Further, the crosslinking agent is preferably at least one selected from the group consisting of a compound having a functional group of any one of an isocyanate group, a glycidyl group, a carboxyl group and an oxazoline group, and a silane coupling agent. Further, the phosphoric acid or phosphate is preferably condensed phosphoric acid or condensed phosphate.

As an example of the corrosion-resistant coating, a dispersion of metal oxides such as aluminum oxide, titanium oxide, cerium oxide, and tin oxide or fine particles of barium sulfate in phosphoric acid is applied to the surface of the barrier layer. Examples include those formed by performing a baking treatment at a temperature of not less than °C.

The corrosion-resistant film may have a laminated structure in which at least one of a cationic polymer and an anionic polymer is further laminated, if necessary. Examples of the cationic polymer and the anionic polymer include those mentioned above.

Note that analysis of the composition of the corrosion resistant film can be performed using, for example, time-of-flight secondary ion mass spectrometry.

The amount of the corrosion resistant film formed on the surface of the barrier layer 3 in the chemical conversion treatment is not particularly limited, but for example, in the case of performing the coating type chromate treatment, a chromic acid compound per 1 m ² of the surface of the barrier layer 3 is used. Is about 0.5 to 50 mg, preferably about 1.0 to 40 mg in terms of chromium, and the phosphorus compound is about 0.5 to 50 mg, preferably about 1.0 to 40 mg in terms of phosphorus, and aminated phenol polymer. Is desirably contained in a ratio of, for example, about 1.0 to 200 mg, preferably about 5.0 to 150 mg.

The thickness of the corrosion-resistant coating is not particularly limited, but from the viewpoint of the cohesive strength of the coating and the adhesion with the barrier layer and the heat-fusible resin layer, it is preferably about 1 nm to 20 μm, more preferably 1 nm to 100 nm. Degree, and more preferably about 1 nm to 50 nm. The thickness of the corrosion resistant film can be measured by observation with a transmission electron microscope, or a combination of observation with a transmission electron microscope and energy dispersive X-ray spectroscopy or electron beam energy loss spectroscopy. By analysis of the composition of the corrosion-resistant coating using time-of-flight secondary ion mass spectrometry, for example, at least one secondary ion consisting of Ce, P, and O (for example, Ce ₂ PO ₄ ⁺ , CePO ₄ ^−, etc. Species) or, for example, a peak derived from a secondary ion composed of Cr, P, and O (for example, at least one of CrPO ₂ ⁺ , CrPO ₄ ⁻ ) is detected.

The chemical conversion treatment is carried out by applying a solution containing a compound used for forming a corrosion-resistant film to the surface of the barrier layer by a bar coating method, a roll coating method, a gravure coating method, an immersion method, or the like, and then applying the temperature of the barrier layer. Is carried out by heating so that the temperature becomes about 70 to 200°C. In addition, the barrier layer may be subjected to a degreasing treatment by an alkali dipping method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method, or the like before the barrier layer is subjected to the chemical conversion treatment. By performing the degreasing treatment as described above, it becomes possible to more efficiently perform the chemical conversion treatment on the surface of the barrier layer. Further, by using an acid degreasing agent in which a fluorine-containing compound is dissolved in an inorganic acid for degreasing treatment, it is possible to form not only the degreasing effect of the metal foil but also a passive metal fluoride. In such cases, only degreasing treatment may be performed.

[The heat-fusible resin layer 4]
In the exterior material for an electricity storage device of the present disclosure, the heat-fusible resin layer 4 corresponds to the innermost layer, and the heat-fusible resin layers are heat-fused to each other during assembly of the electricity storage device to seal the electricity storage device element. It is a layer (sealant layer) that exerts.

The resin constituting the heat-fusible resin layer 4 is not particularly limited as long as it can be heat-fused, but a resin containing a polyolefin skeleton such as polyolefin or acid-modified polyolefin is preferable. The fact that the resin constituting the heat-fusible resin layer 4 contains a polyolefin skeleton can be analyzed by, for example, infrared spectroscopy, gas chromatography mass spectrometry, or the like. Further, when the resin forming the heat-fusible resin layer 4 is analyzed by infrared spectroscopy, it is preferable that a peak derived from maleic anhydride is detected. For example, when measuring the infrared spectroscopy at a maleic anhydride-modified polyolefin, a peak derived from maleic acid is detected in the vicinity of the wave number of 1760 cm ^-1 and near the wave number 1780 cm ^-1. When the heat-fusible resin layer 4 is a layer composed of a maleic anhydride-modified polyolefin, a peak derived from maleic anhydride is detected when measured by infrared spectroscopy. However, if the degree of acid modification is low, the peak may be too small to be detected. In that case, it can be analyzed by nuclear magnetic resonance spectroscopy.

Specific examples of the polyolefin include polyethylene such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene; ethylene-α olefin copolymers; homopolypropylene, polypropylene block copolymers (for example, propylene and Examples thereof include ethylene block copolymers) and polypropylene random copolymers (for example, random copolymers of propylene and ethylene); propylene-α-olefin copolymers; ethylene-butene-propylene terpolymers. Of these, polypropylene is preferred. When the polyolefin resin is a copolymer, it may be a block copolymer or a random copolymer. These polyolefin resins may be used alone or in combination of two or more.

Also, the polyolefin may be a cyclic polyolefin. The cyclic polyolefin is a copolymer of an olefin and a cyclic monomer, and examples of the olefin which is a constituent monomer of the cyclic polyolefin include ethylene, propylene, 4-methyl-1-pentene, styrene, butadiene, isoprene and the like. To be Examples of the cyclic monomer that is a constituent monomer of the cyclic polyolefin include cyclic alkenes such as norbornene; cyclic dienes such as cyclopentadiene, dicyclopentadiene, cyclohexadiene and norbornadiene. Of these, cyclic alkenes are preferable, and norbornene is more preferable.

Acid-modified polyolefin is a polymer modified by block or graft polymerization of polyolefin with an acid component. As the acid-modified polyolefin, the above polyolefin, a copolymer obtained by copolymerizing the above polyolefin with a polar molecule such as acrylic acid or methacrylic acid, or a polymer such as a crosslinked polyolefin can be used. Examples of the acid component used for the acid modification include carboxylic acids such as maleic acid, acrylic acid, itaconic acid, crotonic acid, maleic anhydride, and itaconic anhydride, or anhydrides thereof.

The acid-modified polyolefin may be an acid-modified cyclic polyolefin. The acid-modified cyclic polyolefin is a polymer obtained by copolymerizing part of the monomers constituting the cyclic polyolefin in place of the acid component, or by block-polymerizing or graft-polymerizing the acid component with respect to the cyclic polyolefin. is there. The acid-modified cyclic polyolefin is the same as described above. The acid component used for the acid modification is the same as the acid component used for the modification of the polyolefin.

Preferred acid-modified polyolefins include polyolefins modified with carboxylic acids or their anhydrides, polypropylene modified with carboxylic acids or their anhydrides, maleic anhydride-modified polyolefins, maleic anhydride-modified polypropylenes.

The heat-fusible resin layer 4 may be formed of one type of resin alone, or may be formed of a blend polymer in which two or more types of resins are combined. Furthermore, the heat-fusible resin layer 4 may be formed of only one layer, but may be formed of two or more layers of the same or different resin.

Further, the heat-fusible resin layer 4 may contain a lubricant and the like, if necessary. When the heat-fusible resin layer 4 contains a lubricant, the formability of the exterior material for an electricity storage device can be improved. The lubricant is not particularly limited, and a known lubricant can be used. The lubricant may be used alone or in combination of two or more.

The lubricant is not particularly limited, but an amide lubricant is preferable. Specific examples of the lubricant include those exemplified for the base material layer 1. The lubricant may be used alone or in combination of two or more.

When a lubricant is present on the surface of the heat-fusible resin layer 4, the amount of the lubricant is not particularly limited, but from the viewpoint of enhancing the moldability of the exterior material for an electricity storage device, it is preferably about 10 to 50 mg/m ^2. And more preferably about 15 to 40 mg/m ² .

The lubricant present on the surface of the heat-fusible resin layer 4 may be one in which the lubricant contained in the resin constituting the heat-fusible resin layer 4 is exuded, or the lubricant of the heat-fusible resin layer 4 The surface may be coated with a lubricant.

The thickness of the heat-fusible resin layer 4 is not particularly limited as long as the heat-fusible resin layers have a function of heat-sealing each other and sealing the electricity storage device element, but for example, about 100 μm or less, preferably The thickness is about 85 μm or less, more preferably about 15 to 85 μm. Note that, for example, when the thickness of the adhesive layer 5 described later is 10 μm or more, the thickness of the heat-fusible resin layer 4 is preferably about 85 μm or less, more preferably about 15 to 45 μm. When the thickness of the adhesive layer 5 described later is less than 10 μm or when the adhesive layer 5 is not provided, the thickness of the heat-fusible resin layer 4 is preferably about 20 μm or more, more preferably 35 to 85 μm. The degree can be mentioned.

[Adhesive layer 5]
In the exterior material for an electricity storage device of the present disclosure, the adhesive layer 5 is provided between the barrier layer 3 (or the corrosion resistant film (such as an acid resistant film)) and the heat-fusible resin layer 4 in order to firmly bond them. It is a layer provided as necessary.

The adhesive layer 5 is formed of a resin that can bond the barrier layer 3 and the heat-fusible resin layer 4 together. As the resin used for forming the adhesive layer 5, for example, the same resins as those exemplified for the adhesive layer 2 can be used. The resin used for forming the adhesive layer 5 preferably contains a polyolefin skeleton, and examples thereof include the polyolefins and the acid-modified polyolefins described above as examples of the heat-fusible resin layer 4. The fact that the resin constituting the adhesive layer 5 contains a polyolefin skeleton can be analyzed by, for example, infrared spectroscopy, gas chromatography mass spectrometry, etc., and the analysis method is not particularly limited. In addition, when the resin forming the adhesive layer 5 is analyzed by infrared spectroscopy, it is preferable that a peak derived from maleic anhydride is detected. For example, when measuring the infrared spectroscopy at a maleic anhydride-modified polyolefin, a peak derived from maleic acid is detected in the vicinity of the wave number of 1760 cm ^-1 and near the wave number 1780 cm ^-1. However, if the degree of acid modification is low, the peak may be too small to be detected. In that case, it can be analyzed by nuclear magnetic resonance spectroscopy.

From the viewpoint of firmly adhering the barrier layer 3 and the heat-fusible resin layer 4, the adhesive layer 5 preferably contains an acid-modified polyolefin. As the acid-modified polyolefin, a polyolefin modified with a carboxylic acid or an anhydride thereof, a polypropylene modified with a carboxylic acid or an anhydride thereof, a maleic anhydride modified polyolefin, and a maleic anhydride modified polypropylene are particularly preferable.

Further, from the viewpoint of making the exterior material for an electricity storage device thinner while also providing an exterior material for an electricity storage device excellent in shape stability after molding, the adhesive layer 5 is a resin composition containing an acid-modified polyolefin and a curing agent. It is more preferable that the cured product is. As the acid-modified polyolefin, those mentioned above can be preferably exemplified.

The adhesive layer 5 is a cured product of a resin composition containing an acid-modified polyolefin and at least one selected from the group consisting of a compound having an isocyanate group, a compound having an oxazoline group, and a compound having an epoxy group. It is preferable that the cured product of the resin composition contains an acid-modified polyolefin and at least one selected from the group consisting of a compound having an isocyanate group and a compound having an epoxy group. The adhesive layer 5 preferably contains at least one selected from the group consisting of polyurethane, polyester, and epoxy resin, and more preferably contains polyurethane and epoxy resin. As the polyester, for example, an amide ester resin is preferable. The amide ester resin is generally produced by the reaction of a carboxyl group and an oxazoline group. The adhesive layer 5 is more preferably a cured product of a resin composition containing at least one of these resins and the acid-modified polyolefin. When unreacted compounds such as a compound having an isocyanate group, a compound having an oxazoline group, and a curing agent such as an epoxy resin remain in the adhesive layer 5, the presence of the unreacted substance is determined by, for example, infrared spectroscopy, It can be confirmed by a method selected from Raman spectroscopy, time-of-flight secondary ion mass spectrometry (TOF-SIMS), and the like.

Further, from the viewpoint of further improving the adhesiveness between the barrier layer 3 and the adhesive layer 5, the adhesive layer 5 is at least selected from the group consisting of an oxygen atom, a heterocycle, a C═N bond, and a C—O—C bond. It is preferably a cured product of a resin composition containing one type of curing agent. Examples of the curing agent having a heterocycle include a curing agent having an oxazoline group and a curing agent having an epoxy group. Examples of the curing agent having a C=N bond include a curing agent having an oxazoline group and a curing agent having an isocyanate group. Further, examples of the curing agent having a C—O—C bond include a curing agent having an oxazoline group, a curing agent having an epoxy group, and polyurethane. The fact that the adhesive layer 5 is a cured product of a resin composition containing these curing agents means, for example, gas chromatograph mass spectrometry (GCMS), infrared spectroscopy (IR), time-of-flight secondary ion mass spectrometry (TOF). -SIMS), X-ray photoelectron spectroscopy (XPS) and the like.

The compound having an isocyanate group is not particularly limited, but from the viewpoint of effectively enhancing the adhesiveness between the barrier layer 3 and the adhesive layer 5, a polyfunctional isocyanate compound is preferable. The polyfunctional isocyanate compound is not particularly limited as long as it is a compound having two or more isocyanate groups. Specific examples of the polyfunctional isocyanate-based curing agent include pentane diisocyanate (PDI), isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), and polymerization or nurate thereof. And the like, and mixtures thereof and copolymers with other polymers. Moreover, an adduct body, a burette body, an isocyanurate body, etc. are mentioned.

The content of the compound having an isocyanate group in the adhesive layer 5 is preferably in the range of 0.1 to 50% by mass, and preferably 0.5 to 40% by mass in the resin composition constituting the adhesive layer 5. It is more preferable to be in the range. Thereby, the adhesiveness between the barrier layer 3 and the adhesive layer 5 can be effectively enhanced.

The compound having an oxazoline group is not particularly limited as long as it is a compound having an oxazoline skeleton. Specific examples of the compound having an oxazoline group include those having a polystyrene main chain and those having an acrylic main chain. Examples of commercially available products include Epocros series manufactured by Nippon Shokubai Co., Ltd.

The ratio of the compound having an oxazoline group in the adhesive layer 5 is preferably in the range of 0.1 to 50% by mass, and in the range of 0.5 to 40% by mass in the resin composition constituting the adhesive layer 5. Is more preferable. Thereby, the adhesiveness between the barrier layer 3 and the adhesive layer 5 can be effectively enhanced.

Examples of compounds having an epoxy group include epoxy resins. The epoxy resin is not particularly limited as long as it is a resin that can form a crosslinked structure by an epoxy group existing in the molecule, and a known epoxy resin can be used. The weight average molecular weight of the epoxy resin is preferably about 50 to 2000, more preferably about 100 to 1000, and further preferably about 200 to 800. In the present disclosure, the weight average molecular weight of the epoxy resin is a value measured by gel permeation chromatography (GPC), which is measured under the condition that polystyrene is used as a standard sample.

Specific examples of the epoxy resin include a glycidyl ether derivative of trimethylolpropane, bisphenol A diglycidyl ether, modified bisphenol A diglycidyl ether, novolac glycidyl ether, glycerin polyglycidyl ether, and polyglycerin polyglycidyl ether. The epoxy resins may be used alone or in combination of two or more.

The proportion of the epoxy resin in the adhesive layer 5 is preferably in the range of 0.1 to 50% by mass, and in the range of 0.5 to 40% by mass in the resin composition constituting the adhesive layer 5. Is more preferable. Thereby, the adhesiveness between the barrier layer 3 and the adhesive layer 5 can be effectively enhanced.

The polyurethane is not particularly limited, and known polyurethane can be used. The adhesive layer 5 may be, for example, a cured product of two-component curing type polyurethane.

The proportion of polyurethane in the adhesive layer 5 is preferably in the range of 0.1 to 50% by mass, and more preferably in the range of 0.5 to 40% by mass in the resin composition constituting the adhesive layer 5. More preferable. As a result, the adhesiveness between the barrier layer 3 and the adhesive layer 5 can be effectively increased in an atmosphere in which a component that induces corrosion of the barrier layer, such as an electrolytic solution, exists.

When the adhesive layer 5 is a cured product of a resin composition containing at least one selected from the group consisting of a compound having an isocyanate group, a compound having an oxazoline group, and an epoxy resin, and the acid-modified polyolefin. The acid-modified polyolefin functions as a main agent, and the compound having an isocyanate group, the compound having an oxazoline group, and the compound having an epoxy group each function as a curing agent.

The thickness of the adhesive layer 5 is preferably about 50 μm or less, about 40 μm or less, about 30 μm or less, about 20 μm or less, about 5 μm or less. The thickness of the adhesive layer 5 is preferably about 0.1 μm or more and about 0.5 μm or more. The thickness range is preferably about 0.1 to 50 μm, about 0.1 to 40 μm, about 0.1 to 30 μm, about 0.1 to 20 μm, about 0.1 to 5 μm, about 0.5 to Examples include about 50 μm, about 0.5 to 40 μm, about 0.5 to 30 μm, about 0.5 to 20 μm, about 0.5 to 5 μm. More specifically, in the case of the adhesive exemplified in the adhesive layer 2 or a cured product of an acid-modified polyolefin and a curing agent, it is preferably about 1 to 10 μm, more preferably about 1 to 5 μm. When the resin exemplified in the heat-fusible resin layer 4 is used, it is preferably about 2 to 50 μm, more preferably about 10 to 40 μm. When the adhesive layer 5 is a cured product of the adhesive exemplified in the adhesive layer 2 or a resin composition containing an acid-modified polyolefin and a curing agent, for example, the resin composition is applied and cured by heating or the like. As a result, the adhesive layer 5 can be formed. When the resin exemplified in the heat-fusible resin layer 4 is used, the heat-fusible resin layer 4 and the adhesive layer 5 can be formed by extrusion molding, for example.

[Surface coating layer 6]
The exterior material for an electricity storage device of the present disclosure is, if necessary, on the base material layer 1 (base material layer 1 for the purpose of at least one of improvement in designability, electrolytic solution resistance, scratch resistance, moldability, etc.). The surface coating layer 6 may be provided on the side opposite to the barrier layer 3). The surface coating layer 6 is a layer located on the outermost layer side of the exterior material for an electricity storage device when the electricity storage device is assembled using the exterior material for an electricity storage device. As described above, in the electricity storage device exterior material of the present disclosure, by providing the layer containing the blue colorant outside the barrier layer, under the light source in the yellow room, the identification property of the identification mark printed on the surface is improved. The excellent effect is exhibited. However, although the exterior material for an electricity storage device may be slightly blue and color unevenness may be visually recognized, when the surface coating layer 6 is provided as the outermost layer of the exterior material for an electricity storage device of the present disclosure, the surface coating is performed. Since the layer has an effect of diffusing light and suppressing gloss, there is an advantage that occurrence of color unevenness is suppressed and appearance uniformity is enhanced. On the other hand, when the outermost layer of the exterior material for an electricity storage device of the present disclosure does not have the surface coating layer 6, the surface of the exterior material for an electricity storage device is high in gloss and scratches are easily noticeable, but the surface coating layer 6 is provided. In this case, since the surface coating layer has an effect of diffusing light and suppressing gloss, there is also an advantage that scratches are less noticeable. These advantages are particularly likely to be exhibited when the surface coating layer 6 contains the below-described additive (particularly a matting agent).

Further, in the exterior material for an electricity storage device of the present disclosure, the surface coating layer 6 is colored in black to form an exterior material for an electricity storage device having a black appearance, and then the above-mentioned blue agent is mixed to form a barrier. It may be a layer containing a blue colorant, which is located outside the layer 3. For example, the surface coating layer 6 is colored black to form an exterior material for an electricity storage device that has a black appearance, and then a blue agent is added to the surface coating layer 6 to give the tint of the exterior material 10 for an electricity storage device. Can be adjusted to enhance the distinguishability described above. From the viewpoint of enhancing the distinctiveness, after the surface coating layer 6 is blended with a blue colorant, the composition such as the type and content of the colorant contained in the surface coating layer 6, the base layer 1, and if necessary. For the electricity storage device by adjusting the composition of the layer located outside the barrier layer 3 such as the adhesive layer 2 and the colored layer 21 provided as well as the aging condition of the exterior material for the electricity storage device described later. The color of the exterior material 10 can be adjusted.

The surface coating layer 6 can be formed of a resin such as polyvinylidene chloride, polyester, polyurethane, acrylic resin, or epoxy resin.

When the resin forming the surface coating layer 6 is a curable resin, the resin may be either a one-component curing type or a two-component curing type, but is preferably a two-component curing type. Examples of the two-component curing type resin include two-component curing type polyurethane, two-component curing type polyester, and two-component curing type epoxy resin. Of these, two-component curing type polyurethane is preferable.

The two-component curing type polyurethane includes, for example, a polyurethane containing a base compound containing a polyol compound and a curing agent containing an isocyanate compound. Preferred is a two-component curing type polyurethane having a polyol such as a polyester polyol, a polyether polyol and an acrylic polyol as a main component and an aromatic or aliphatic polyisocyanate as a curing agent. Further, as the polyol compound, it is preferable to use a polyester polyol having a hydroxyl group at the side chain in addition to the hydroxyl group at the terminal of the repeating unit. Examples of the curing agent include aliphatic, alicyclic, aromatic and araliphatic isocyanate compounds. Examples of the isocyanate compound include hexamethylene diisocyanate (HDI) xylylene diisocyanate (XDI), isophorone diisocyanate (IPDI), hydrogenated XDI (H6XDI), hydrogenated MDI (H12MDI), tolylene diisocyanate (TDI), diphenylmethane diisocyanate ( MDI), naphthalene diisocyanate (NDI) and the like. Moreover, the polyfunctional isocyanate modified body etc. from 1 type or 2 types or more of these diisocyanates are mentioned. Further, a multimer (for example, trimer) can be used as the polyisocyanate compound. Examples of such a multimer include an adduct body, a biuret body, and a nurate body. Since the surface coating layer 6 is made of polyurethane, excellent electrolytic solution resistance is imparted to the exterior material for an electricity storage device.

The surface coating layer 6 is provided on at least one of the surface and the inside of the surface coating layer 6 depending on the surface coating layer 6 and the functionality to be provided on the surface, and if necessary, the above-mentioned lubricant and colorant. , An anti-blocking agent, a matting agent, a flame retardant, an antioxidant, a tackifier, and an antistatic agent may be added. Examples of the additive include fine particles having an average particle diameter of about 0.5 nm to 5 μm. The average particle diameter of the additive is a median diameter measured by a laser diffraction/scattering type particle diameter distribution measuring device.

The additive may be an inorganic substance or an organic substance. Also, the shape of the additive is not particularly limited, and examples thereof include spherical shape, fibrous shape, plate shape, amorphous shape, and scale shape.

Specific examples of the additive include talc, silica, graphite, kaolin, montmorillonite, mica, hydrotalcite, silica gel, zeolite, aluminum hydroxide, magnesium hydroxide, zinc oxide, magnesium oxide, aluminum oxide, neodymium oxide, antimony oxide. , Titanium oxide, cerium oxide, calcium sulfate, barium sulfate, calcium carbonate, calcium silicate, lithium carbonate, calcium benzoate, calcium oxalate, magnesium stearate, alumina, carbon black, carbon nanotubes, high melting point nylon, acrylate resin, Examples include crosslinked acrylic, crosslinked styrene, crosslinked polyethylene, benzoguanamine, gold, aluminum, copper and nickel. The additives may be used alone or in combination of two or more. Among these additives, calcium carbonate is preferably used from the viewpoint of improving the distinguishability. Since calcium carbonate is bluish, it can be made more bluish by using it as an additive for the surface coating layer. Further, it is preferable to use silica and calcium carbonate mixed as an additive. By using silica as an additive for the surface coating layer, the reflected light can be easily diffused, and the outer appearance of the electricity storage device exterior can be made more bluish. Among these additives, silica, barium sulfate and titanium oxide are preferable from the viewpoint of dispersion stability and cost. Further, the additive may be subjected to various surface treatments such as insulation treatment and high dispersibility treatment on the surface.

When the surface coating layer 6 contains a coloring agent, known coloring agents such as pigments and dyes can be used. In addition, as the colorant, only one kind may be used, or two or more kinds may be mixed and used. Specific examples of the colorant contained in the surface coating layer 6 are the same as those exemplified in the section of [Adhesive layer 2]. The preferable content of the colorant contained in the surface coating layer 6 is also the same as the content described in the section of [Adhesive layer 2].

For example, when the surface coating layer 6 is blended with a black agent, the content of the black agent in the surface coating layer 6 is not particularly limited as long as the exterior material for an electricity storage device is colored black, and is, for example, 5 to 60% by mass. The amount is preferably about 10 to 40% by mass. When a blue agent is added to the surface coating layer 6, the content of the blue agent in the surface coating layer 6 is not particularly limited as long as the exterior material for an electricity storage device is colored black, and is, for example, 0.5 to 30. The amount is about mass%, preferably 1 to 20 mass%.

Further, for example, when the surface coating layer 6 is mixed with a black agent and a blue agent, the ratio of the black agent and the blue agent in the surface coating layer 6 is preferably 100 parts by mass of the black agent, and the ratio of the blue agent is preferably. It is about 0.1 part by mass or more, more preferably about 1 part by mass or more, still more preferably about 10 parts by mass or more. The ratio of the blue colorant is preferably about 150 parts by mass or less, more preferably about 100 parts by mass or less. The preferred range of the blue colorant is about 0.1 to 150 parts by mass, about 0.1 to 100 parts by mass, about 1 to 150 parts by mass, about 1 to 100 parts by mass, about 10 to 150 parts by mass, 10 It is about 100 parts by mass.

The method of forming the surface coating layer 6 is not particularly limited, and examples thereof include a method of applying a resin forming the surface coating layer 6. When the surface coating layer 6 contains an additive, a resin mixed with the additive may be applied.

The thickness of the surface coating layer 6 is not particularly limited as long as it exhibits the above-mentioned functions as the surface coating layer 6, and is, for example, about 0.5 to 10 μm, preferably about 1 to 5 μm.

For example, when the adhesive layer is a layer colored black, the surface coating layer located outside the adhesive layer is preferably transparent or translucent.

3. The preparation method of the production method for an electricity storage device exterior material of the outer package for a power storage device, as long as the laminate exterior material for a power storage device formed by laminating the layers with the present invention are obtained is not particularly limited, at least, the substrate The method includes a step of laminating the layer 1, the barrier layer 3, and the heat-fusible resin layer 4 in this order. Specifically, a method for manufacturing an exterior material for an electricity storage device according to the present disclosure is a method for producing an exterior material for an electricity storage device having a black appearance, and at least a base material layer and a barrier layer in order from the outside. The method includes a step of obtaining a laminated body in which a heat-fusible resin layer is laminated, and the laminated body includes a layer containing a blue colorant outside the barrier layer.

The following is an example of a method for manufacturing the exterior material for an electricity storage device of the present invention. First, a laminated body in which the base material layer 1, the adhesive layer 2, and the barrier layer 3 are laminated in order (hereinafter, also referred to as “laminated body A”) is formed. Specifically, the laminate A is formed by applying the adhesive used for forming the adhesive layer 2 on the base material layer 1 or the barrier layer 3 whose surface has been subjected to chemical conversion treatment, as required by the gravure coating method, It can be performed by a dry laminating method in which the barrier layer 3 or the base material layer 1 is laminated and the adhesive layer 2 is cured after coating and drying by a coating method such as a roll coating method.

Next, the heat-fusible resin layer 4 is laminated on the barrier layer 3 of the laminate A. When the heat-fusible resin layer 4 is directly laminated on the barrier layer 3, the heat-fusible resin layer 4 is laminated on the barrier layer 3 of the laminate A by a method such as a thermal laminating method or an extrusion laminating method. do it. When the adhesive layer 5 is provided between the barrier layer 3 and the heat-fusible resin layer 4, for example, (1) the adhesive layer 5 and the heat-fusible resin layer are provided on the barrier layer 3 of the laminate A. Method of laminating by extruding 4 (coextrusion laminating method, tandem laminating method), (2) Separately, a laminated body in which the adhesive layer 5 and the heat-fusible resin layer 4 are laminated is formed, and the laminated body A By a thermal lamination method, or by forming a laminated body in which the adhesive layer 5 is laminated on the barrier layer 3 of the laminated body A, and by using the thermal fusion bonding resin layer 4 and the thermal lamination method. Method of Laminating, (3) While pouring the melted adhesive layer 5 between the barrier layer 3 of the laminate A and the heat-fusible resin layer 4 which is formed into a sheet in advance, the adhesive layer 5 is interposed. The laminate A and the heat-fusible resin layer 4 are laminated together (sandwich laminating method), (4) the barrier layer 3 of the laminate A is solution-coated with an adhesive for forming the adhesive layer 5, Examples thereof include a method of drying, a method of further baking, and a method of laminating the heat-fusible resin layer 4 formed in advance into a sheet on the adhesive layer 5.

When the surface coating layer 6 is provided, the surface coating layer 6 is laminated on the surface of the base material layer 1 opposite to the barrier layer 3. The surface coating layer 6 can be formed, for example, by applying the above-mentioned resin forming the surface coating layer 6 to the surface of the base material layer 1. The order of the step of laminating the barrier layer 3 on the surface of the base material layer 1 and the step of laminating the surface coating layer 6 on the surface of the base material layer 1 is not particularly limited. For example, after forming the surface coating layer 6 on the surface of the base material layer 1, the barrier layer 3 may be formed on the surface of the base material layer 1 opposite to the surface coating layer 6.

As described above, in order from the outside, the surface coating layer 6/the base material layer 1/the adhesive layer 2/the barrier layer 3/if necessary, which is provided as needed/the adhesive layer 5 is provided if necessary. / A laminated body including the heat-fusible resin layer 4 is formed, but in order to strengthen the adhesiveness of the adhesive layer 2 and the adhesive layer 5 which are provided as necessary, they may be further subjected to a heat treatment. Good.

In the exterior material for an electricity storage device, each layer constituting the laminate may be subjected to surface activation treatment such as corona treatment, blast treatment, oxidation treatment, or ozone treatment, if necessary, to improve processability. .. For example, the printability of the ink on the surface of the base material layer 1 can be improved by performing corona treatment on the surface of the base material layer 1 opposite to the barrier layer 3.

It is preferable that the exterior material for an electricity storage device is subjected to an aging treatment after each layer is laminated. By changing the aging condition of the exterior material for an electricity storage device, the tint of the exterior material for an electricity storage device having a black appearance can be changed. Therefore, it is preferable to select the aging treatment condition for the purpose of adjusting the color. Examples of adjustment items for the aging treatment conditions include a temperature rising rate, a heating temperature, a heating time, the presence or absence of pretreatment, and the temperature thereof. In addition, as a main factor that the tint changes depending on the aging treatment conditions, it is mentioned that the degree of aggregation of the colorant contained in the exterior material for the electricity storage device changes depending on the aging treatment conditions.

4. Application of Exterior Material for Electric Storage Device The exterior material for an electric storage device according to the present disclosure is used for a package for hermetically containing an electric storage device element such as a positive electrode, a negative electrode, and an electrolyte. That is, a power storage device can be obtained by accommodating a power storage device element including at least a positive electrode, a negative electrode, and an electrolyte in a package formed of the power storage device exterior material of the present disclosure.

Specifically, an electricity storage device element including at least a positive electrode, a negative electrode, and an electrolyte is used in a state in which a metal terminal connected to each of the positive electrode and the negative electrode is projected to the outside in the exterior material for an electricity storage device of the present disclosure. To cover the periphery of the electricity storage device element so that a flange portion (a region where the heat-fusible resin layers contact each other) can be formed, and heat-seal the heat-fusible resin layers of the flange portion to hermetically seal them. Thus, an electricity storage device using the exterior material for an electricity storage device is provided. Note that, when accommodating an electricity storage device element in a package formed of the electricity storage device exterior material of the present disclosure, the heat-fusible resin portion of the electricity storage device exterior material of the present disclosure is inside (a surface that contacts the electricity storage device element). ), and a package is formed.

The exterior material for an electricity storage device according to the present disclosure can be suitably used for an electricity storage device such as a battery (including a capacitor and a capacitor). Further, the exterior material for an electricity storage device of the present disclosure may be used for either a primary battery or a secondary battery, but is preferably a secondary battery. The type of secondary battery to which the exterior material for an electricity storage device of the present disclosure is applied is not particularly limited, and examples thereof include a lithium-ion battery, a lithium-ion polymer battery, an all-solid-state battery, a lead storage battery, a nickel-hydrogen storage battery, and a nickel-metal hydride storage battery. Examples thereof include a cadmium storage battery, a nickel/iron storage battery, a nickel/zinc storage battery, a silver oxide/zinc storage battery, a metal-air battery, a polyvalent cation battery, a capacitor and a capacitor. Among these secondary batteries, lithium ion batteries and lithium ion polymer batteries can be cited as suitable targets to which the exterior material for an electricity storage device of the present disclosure is applied.

The present disclosure will be described in detail below with reference to examples and comparative examples. However, the present disclosure is not limited to the embodiments.

<Manufacture of exterior materials for power storage devices>
Examples 1-5 and 10 and Comparative Example 1
A stretched nylon (ONy) film (thickness: 15 μm) was prepared as a base material layer. An aluminum foil (JIS H4160:1994 A8021H-O (thickness 35 μm)) was prepared as a barrier layer. Next, the barrier layer and the base material layer are laminated by a dry lamination method using an adhesive (two-component urethane adhesive containing a colorant) described below, and then the base material layer is subjected to aging treatment. A laminate of /adhesive layer/barrier layer was produced. Both sides of the aluminum foil are subjected to chemical conversion treatment. The chemical conversion treatment of the aluminum foil is performed by roll-coating the both surfaces of the aluminum foil with a treatment liquid consisting of a phenol resin, a chromium fluoride compound, and phosphoric acid so that the coating amount of chromium is 10 mg/m ² (dry mass). It was carried out by coating and baking.

Next, maleic anhydride-modified polypropylene as an adhesive layer (thickness 20 μm) and random polypropylene as a heat-fusible resin layer (thickness 20 μm) were formed on the barrier layer of each laminate obtained above. Was coextruded to laminate the adhesive layer/heat-fusible resin layer on the barrier layer. Further, a resin composition containing silica particles (resin is a polyurethane resin formed from a mixture of a polyol compound and an isocyanate compound) is applied to the surface of the base material layer of the obtained laminate so as to have a thickness of 3 μm. By forming a matte surface coating layer, the surface coating layer (3 μm)/base material layer (thickness 15 μm)/adhesive layer (3 μm)/barrier layer (35 μm)/adhesion are formed in order from the outside. A layered product (total thickness 96 μm) in which the layer (20 μm)/heat-fusible resin layer (20 μm) was layered was obtained.

Example 6
In Example 1, except that the surface coating layer was not formed, in the same manner as in Example 1, base material layer (thickness 15 μm)/adhesive layer (3 μm)/barrier layer (35 μm)/adhesive layer ( 20 μm)/heat-fusible resin layer (20 μm) was obtained to obtain a laminate (total thickness 93 μm).

Example 7
In Example 2, except that the surface coating layer was not formed, in the same manner as in Example 2, the base material layer (thickness 15 μm)/adhesive layer (3 μm)/barrier layer (35 μm)/adhesive layer ( 20 μm)/heat-fusible resin layer (20 μm) was obtained to obtain a laminate (total thickness 93 μm).

Example 8
In Example 3, except that the surface coating layer was not formed, in the same manner as in Example 3, the base material layer (thickness 15 μm)/adhesive layer (3 μm)/barrier layer (35 μm)/adhesive layer ( 20 μm)/heat-fusible resin layer (20 μm) was obtained to obtain a laminate (total thickness 93 μm).

Examples 9, 11-14
In Example 1, except that the surface coating layer was not formed and that the adhesives C4 to C8 described in Table 1 were used instead of the adhesive C1 as the adhesive used for forming the adhesive layer. Is a substrate layer (thickness 15 μm)/adhesive layer (3 μm)/barrier layer (35 μm)/adhesive layer (20 μm)/heat-fusible resin layer (20 μm) laminated in the same manner as in Example 1. A laminated body (total thickness 93 μm) was obtained.

<Adhesive>
The following adhesives were used for forming the adhesive layer between the base material layer and the barrier layer. Table 1 shows the types of adhesives used in each example and comparative example.
[Adhesive B]
Two-component urethane adhesive (mixture of polyol compound and aromatic isocyanate compound) containing carbon black (secondary particle diameter 0.2 μm) as a blackening agent
[Adhesive C1]
Carbon black was used as a blackening agent. Two-component urethane adhesive containing 4 parts by mass of copper phthalocyanine as a blue agent with respect to 26 parts by mass of carbon black (mixture of polyol compound and aromatic isocyanate compound)
[Adhesive C2]
Carbon black was used as a blackening agent. Two-component urethane adhesive (mixture of polyol compound and aromatic isocyanate compound) containing 15 parts by mass of copper phthalocyanine as a blue agent with respect to 15 parts by mass of carbon black.
[Adhesive C3]
Carbon black was used as a blackening agent. Two-component urethane adhesive containing 17 parts by mass of copper phthalocyanine as a blue agent with respect to 13 parts by mass of carbon black (mixture of polyol compound and aromatic isocyanate compound)
[Adhesive C4]
As the black colorant, the same carbon black as the carbon black contained in the adhesive B was used. Two-component urethane adhesive containing 10 parts by mass of copper phthalocyanine as a blue agent with respect to 20 parts by mass of carbon black (mixture of polyol compound and aromatic isocyanate compound)
[Adhesive C5]
As the black colorant, the same carbon black as the carbon black contained in the adhesive B was used. Two-component urethane adhesive containing 12 parts by mass of copper phthalocyanine as a blue agent with respect to 18 parts by mass of carbon black (mixture of polyol compound and aromatic isocyanate compound)
[Adhesive C6]
As the black colorant, the same carbon black as the carbon black contained in the adhesive B was used. Two-component urethane adhesive containing 8 parts by mass of copper phthalocyanine as a blue agent with respect to 22 parts by mass of carbon black (mixture of polyol compound and aromatic isocyanate compound)
[Adhesive C7]
As the black colorant, the same carbon black as the carbon black contained in the adhesive B was used. Two-component urethane adhesive containing 14 parts by mass of copper phthalocyanine as a blue agent with respect to 16 parts by mass of carbon black (mixture of polyol compound and aromatic isocyanate compound)
[Adhesive C8]
As the black colorant, the same carbon black as the carbon black contained in the adhesive B was used. Two-component urethane adhesive containing 116 parts by mass of copper phthalocyanine as a blue agent with respect to 14 parts by mass of carbon black (mixture of polyol compound and aromatic isocyanate compound)

<Aging treatment conditions>
The aging treatment conditions used for adjusting the color observed from the outside of the exterior material for the electricity storage device manufactured in each of the examples and comparative examples are as follows.
[Condition A]
Let stand for 12 hours in an 80°C environment.
[Condition B]
First, as step 1, it is left standing for 3 hours at room temperature (about 25° C.). Next, as step 2, it is left standing in a 55° C. environment for 3 hours. Next, as step 3, it is left standing in an environment of 80° C. for 12 hours.
[Condition C]
Let stand for 3 days in an environment of 60°C to 100°C.

<Measurement of L ^* value, a ^* value and b ^* value>
Regarding the exterior materials for electricity storage devices obtained in each of the examples and comparative examples, the observation condition of a spectrocolorimeter (CM-700d) manufactured by Konica Minolta Co., Ltd. calibrated with a white calibration cap (CM-A177: manufactured by Konica Minolta) was set to 10 The observation light source was set to F2 and CSI mode (JIS Z8722-2009), and L ^* , a ^* , and b ^* of the outer (base material layer side) surface were measured at room temperature and normal humidity. The measurement was performed at three points on each sample, and the average value is shown in Table 1 as the evaluation result.

<Measurement of Cu element by X-ray fluorescence analysis (XRF)>
With respect to the exterior materials for electricity storage devices obtained in Examples 1 to 3 and Comparative Example 1, the presence or absence of Cu element detection by fluorescent X-ray analysis (XRF) was confirmed under the following measurement conditions. As a result, in Comparative Example 1, no peak derived from Cu element was detected. Further, in Examples 1 to 3, a peak derived from Cu element was detected. The CuKα peak intensity was 0.4 in Example 1, 1.2 in Example 2, and 1.2 in Example 3.
(Measurement condition)
Equipment used: EDX-800HS (manufactured by Shimadzu Corporation)
X-ray: Rh Target voltage: 50kV
Current: 1000 μA
Irradiation area: 100φ
Measurement time: 100 sec
Measurement atmosphere: Vacuum Measurement surface: Outside (X-rays are irradiated on the outside of the exterior material for the electricity storage device)
Analysis method: Automatic strength calculation is performed using the software "PCEDX" attached to EDX-800HS (manufactured by Shimadzu Corporation). Specifically, peak detection is performed on the spectrum obtained by the measurement. The coefficient of the peak detection condition is 10. Next, for the detected peak, the detected intensity is calculated from the intensity calculation.

<Distinguishability in the yellow room>
On the surface of the surface coating layer of the exterior material for an electricity storage device obtained in each of Examples and Comparative Examples, an inkjet printer (Model name 9040 manufactured by Markem Image Co., Ltd.) was used, and a diameter of one dot was about 0.3 mm, A number string "0123456789" having a height of the character string of about 1.5 mm was printed as a sample. The ink used for printing was white. Next, in the yellow room, each sample was visually observed from a position 30 cm away, and the distinctiveness was evaluated according to the following evaluation criteria. The results are shown in Table 1.
(Evaluation criteria)
A: Can be recognized immediately B: It takes a few seconds to recognize C: Can be recognized by changing the sample angle

<Black appearance>
In a room under a fluorescent lamp, each sample prepared in the above <identification in yellow room> was observed with the naked eye, and it was evaluated that the appearance was recognized as black according to the following evaluation criteria. .. The results are shown in Table 1.
(Evaluation criteria)
A: Clearly recognized as black.
B: Blue or red is slightly recognized, but it is recognized as black without any problem C: Blue or red is clearly recognized and may not be recognized as black.

As is clear from the results shown in Table 1, the outer packaging materials for electricity storage devices of Examples 1 to 14 are provided with a layer containing a blue colorant outside the barrier layer, and therefore, for electricity storage devices having a black appearance. It can be seen that the identification mark printed on the surface is excellent in the identification in the yellow room even though it is the exterior material. The exterior materials for electricity storage devices of Examples 1 to 14 were excellent in the identification property of the identification mark printed on the surface not only in the yellow room but also in the room under the general fluorescent lamp. Further, it was possible to recognize that the exterior materials for electricity storage devices of Examples 1 to 14 had a black appearance in a room under a general fluorescent lamp without any problem.

As described above, the present disclosure provides the invention of the aspects described below.
Item 1. An exterior material for an electricity storage device, which has a black appearance,
The exterior material for an electricity storage device is, in order from the outside, composed of a laminate including at least a base material layer, a barrier layer, and a heat-fusible resin layer,
The exterior body for an electricity storage device, wherein the laminate includes a layer containing a blue colorant outside the barrier layer.
Item 2. Item 2. The outer casing material for an electricity storage device according to Item 1, wherein Cu element is detected when an analysis by a fluorescent X-ray analysis method is performed from the outside of the laminate.
Item 3. An adhesive layer is provided between the base layer and the barrier layer,
Item 3. The exterior material for an electricity storage device according to Item 1 or 2, wherein the adhesive layer is a layer containing the blue agent.
Item 4. Between the base layer and the barrier layer, a colored layer is provided,
Item 4. The outer casing material for an electricity storage device according to any one of Items 1 to 3, wherein the colored layer is a layer containing the blue colorant.
Item 5. Item 5. The exterior material for an electricity storage device according to any one of Items 1 to 4, further comprising a surface coating layer on a side of the base material layer opposite to the barrier layer side.
Item 6. A method of manufacturing an exterior material for an electricity storage device, which has a black appearance,
From the outside in order, at least, a base material layer, a barrier layer, and a step of obtaining a laminate in which a heat-fusible resin layer is laminated,
The said laminated body is a manufacturing method of the exterior material for electrical storage devices which has the layer containing a blue agent outside the said barrier layer.
Item 7. An electricity storage device, wherein an electricity storage device element including at least a positive electrode, a negative electrode, and an electrolyte is housed in a package formed of the exterior material for an electricity storage device according to any one of Items 1 to 5.

DESCRIPTION OF SYMBOLS 1 Base material layer 2 Adhesive layer 21 Colored layer 3 Barrier layer 4 Heat-fusible resin layer 5 Adhesive layer 6 Surface coating layer 10 Exterior material for power storage devices

Claims

An exterior material for an electricity storage device, which has a black appearance,
The exterior material for an electricity storage device is, in order from the outside, composed of a laminate including at least a base material layer, a barrier layer, and a heat-fusible resin layer,
The exterior body for an electricity storage device, wherein the laminated body includes a layer containing a blue colorant outside the barrier layer.
The exterior material for an electricity storage device according to claim 1, wherein Cu element is detected when an analysis by a fluorescent X-ray analysis method is performed from the outside of the laminate.
An adhesive layer is provided between the base layer and the barrier layer,
The exterior material for an electricity storage device according to claim 1, wherein the adhesive layer is a layer containing the blue colorant.
Between the base layer and the barrier layer, a colored layer is provided,
The outer casing material for an electricity storage device according to claim 1, wherein the colored layer is a layer containing the blue colorant.
The exterior material for an electricity storage device according to any one of claims 1 to 4, wherein a surface coating layer is provided on a side of the base material layer opposite to the barrier layer side.
A method of manufacturing an exterior material for an electricity storage device, which has a black appearance,
From the outside in order, at least, a base material layer, a barrier layer, and a step of obtaining a laminate in which a heat-fusible resin layer is laminated,
The said laminated body is a manufacturing method of the exterior material for electrical storage devices which has the layer containing a blue agent outside the said barrier layer.
An electricity storage device, in which an electricity storage device element including at least a positive electrode, a negative electrode, and an electrolyte is housed in a package formed of the exterior material for an electricity storage device according to any one of claims 1 to 5.