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

Abstract

To provide an exterior material for a power storage device that has a black appearance but has an excellent identification mark printed on its surface in a yellow room.SOLUTION: An exterior material for a power storage device with a black appearance includes a laminate including, in order from the outside, at least a base material layer, a barrier layer, and a heat-fusible resin layer, and the b* value in the L*a*b* color space of the reflected light measured from the outside of the laminate under the measurement conditions of a SCI method, field of view 10°, and light source F2 is -0.20 or less.

Description

[Technical Field]

[0001] The present disclosure relates to an exterior material for an electricity storage device, a method for producing the same, and an electricity storage device. [Background technology]

[0002] Various types of electricity storage devices have been developed, and in all of them, exterior materials are essential components for sealing electricity storage device elements such as electrodes and electrolytes. Conventionally, metal exterior materials have been widely used as exterior materials for electricity storage devices.

[0003] Meanwhile, in recent years, with the increasing performance of electric vehicles, hybrid electric vehicles, personal computers, cameras, mobile phones, etc., there has been a demand for electricity storage devices to have a variety of shapes as well as to be thinner and lighter in weight. However, the metallic exterior materials for electricity storage devices that have been widely used in the past have the drawbacks of being difficult to keep up with the diversification of shapes and also having limitations on how much they can be made lighter.

[0004] Therefore, in recent years, a film-like laminate in which a base layer, a barrier layer, and a heat-sealable resin layer are laminated in this order has been proposed as an exterior material for an electricity storage device that can be easily processed into a variety of shapes and can be made thinner and lighter (see, for example, Patent Document 1).

[0005] In such an electrical storage device packaging material, a recess is generally formed by cold forming, and electrical storage device elements such as electrodes and electrolyte are placed in the space formed by the recess, and a heat-sealable resin layer is heat-sealed to obtain an electrical storage device in which the electrical storage device elements are housed inside the electrical storage device packaging material. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-287971 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-166261 Summary of the Invention [Problem to be solved by the invention]

[0007] For example, it is sometimes required that power storage devices such as lithium ion secondary batteries be colored black to match the appearance and color of the electrical equipment to which they are attached (see, for example, Patent Document 2).

[0008] Meanwhile, in the manufacturing process of an electricity storage device using an exterior material for an electricity storage device, an identification mark or the like such as product information (for example, letters or numbers indicating a lot number, a barcode or symbol, etc.) may be printed on the surface of the electricity storage device. By attaching an identification mark to the surface of the electricity storage device, it is possible to distinguish, for example, between genuine products and counterfeit products. Similarly, in the manufacturing process of an exterior material for an electricity storage device, an identification mark or the like may be printed on the outer surface.

[0009] However, through investigations conducted by the inventors of the present disclosure, a new problem was discovered in that when the appearance of an electricity storage device or an exterior material for an electricity storage device is colored black, the identifiability of printed identification marks, etc. is reduced during the manufacturing process thereof.

[0010] Specifically, in the manufacturing process of an electricity storage device or an exterior material for an electricity storage device, processing and inspection are sometimes performed under a yellow light source in a yellow room, etc. However, it has been found that when an identification mark or the like is printed on an electricity storage device or an exterior material for an electricity storage device that has a black appearance and processing and inspection are performed under the light source in a yellow room, the identification of the identification mark is reduced, and there is a risk that product information and the like cannot be accurately read.

[0011] Under these circumstances, the main object of the present disclosure is to provide an exterior material for an electricity storage device that has a black appearance but has excellent visibility of an identification mark printed on its surface under a light source in a yellow room. [Means for solving the problem]

[0012] The inventors of the present disclosure have conducted extensive research to solve the above-mentioned problems. As a result, it has been found that in an exterior packaging material for an electricity storage device that is composed of a laminate including at least a base layer, a barrier layer, and a heat-sealable resin layer in this order from the outside and has a black appearance, the L of reflected light measured from the outside under predetermined conditions is * a * b * b in color space * It has been found that by setting the value to a predetermined value or less, it is possible to adjust the black to have a bluish hue, which is the complementary color of yellow, and thereby improve the distinguishability of the identification mark printed on the surface in a yellow room or under the light source of an orange to yellow lamp.

[0013] The present disclosure has been completed based on these findings and further investigations. That is, the present disclosure provides the inventions of the following aspects. An exterior material for an electricity storage device that has a black appearance, the electrical storage device packaging material is composed of a laminate including, in order from the outside, at least a base layer, a barrier layer, and a heat-sealable resin layer; The L of reflected light measured from the outside of the laminate under the measurement conditions of SCI method, field of view 10° and light source F2 * a * b * b in color space * An exterior material for an electricity storage device, wherein the value is -0.20 or less. [Effects of the Invention]

[0014] According to the present disclosure, it is possible to provide an electrical storage device packaging material that has a black appearance but has excellent distinguishability of an identification mark printed on the surface in a yellow room or under a light source of an orange to yellow lamp (Na lamp).The present disclosure also makes it possible to provide a method for manufacturing the electrical storage device packaging material, and an electrical storage device that uses the electrical storage device packaging material. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a schematic diagram showing an example of a cross-sectional structure of an exterior packaging material for an electricity storage device according to the present disclosure. [Figure 2] 1 is a schematic diagram showing an example of a cross-sectional structure of an exterior packaging material for an electricity storage device according to the present disclosure. [Figure 3] 1 is a schematic diagram showing an example of a cross-sectional structure of an exterior packaging material for an electricity storage device according to the present disclosure. [Figure 4] 1 is a schematic diagram showing an example of a cross-sectional structure of an exterior packaging material for an electricity storage device according to the present disclosure. [Figure 5] 1 is a schematic diagram showing an example of a cross-sectional structure of an exterior packaging material for an electricity storage device according to the present disclosure. [Figure 6] 1 is a schematic diagram showing an example of a cross-sectional structure of an exterior packaging material for an electricity storage device according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0016] The packaging material for an electricity storage device according to the present disclosure has a black appearance, and is composed of a laminate including, in order from the outside, at least a base layer, a barrier layer, and a heat-sealable resin layer. The packaging material for an electricity storage device has a black appearance, and is characterized in that the L of reflected light measured from the outside under the measurement conditions of an SCI method, a field of view of 10°, and a light source F2. * a * b * b in color space * The electrical storage device packaging material of the present disclosure is characterized in that the value of the electrical storage device resistance is -0.20 or less. By having this configuration, even though the electrical storage device packaging material has a black appearance, it is possible to exhibit excellent identification of the identification mark printed on the surface under a light source in a yellow room.

[0017] The packaging material for an electricity storage device of the present disclosure will be described in detail below. In this specification, a numerical range indicated by "to" means "not less than" or "not more than." For example, the expression "2 to 15 mm" means 2 mm or more and 15 mm or less.

[0018] Furthermore, in the packaging material for an electricity storage device of the present disclosure, "having a black appearance" means that when the packaging material for an electricity storage device is observed from the outside with the naked eye, it is recognized as being black. More specifically, the "black" in "having a black appearance" is a black color as defined by CIE1976 L * a * b * In the (CIELAB) chromaticity coordinates, L * The value of L is 40 or less, preferably 35 or less. * The value is also the L of reflected light measured from the outside under the measurement conditions of SCI method, field of view 10° and light source F2. * a * b * In color space, black is L * In addition to the value, * The value is preferably −20 to +20, and more preferably −10 to +10. The packaging material for an electricity storage device according to the present disclosure has a black appearance and further has b * It is characterized by a value of -0.20 or less.

[0019] As described below, by adjusting the composition, such as the type and content of additives and colorants contained in each layer constituting the electrical storage device packaging material of the present disclosure (layers located outside the barrier layer, such as the substrate layer, adhesive layer, colored layer, and surface coating layer), the composition of the layers located outside the barrier layer, and further the aging treatment conditions of the electrical storage device packaging material described below, the appearance of the electrical storage device packaging material can be made black, and b * The value can be adjusted by adding at least a black additive or colorant (e.g., black pigment). * It is preferable to adjust the value, but it is also possible to mix multiple types of additives and colorants other than black to make it black, * In addition, among the layers constituting the packaging material for an electricity storage device of the present disclosure, a black additive or colorant may be used in one layer, and a non-black (for example, blue) additive or colorant may be used in the other layers, so that the b * You may adjust the value.

[0020] The term "yellow room" refers to a room where light with wavelengths of 500 nm or less, including ultraviolet light, is blocked, and light in this room appears yellow. Yellow rooms are generally installed, for example, in clean rooms in semiconductor factories to carry out photolithography processes that handle photosensitive materials.

[0021] 1.Layer structure and physical properties of exterior materials for energy storage devices As shown in FIG. 1 , for example, an electrical storage device packaging material 10 according to the present disclosure is composed of a laminate including, in order from the outside, a base material layer 1, a barrier layer 3, and a heat-sealable resin layer 4. In the electrical storage device packaging material 10, the base material layer 1 is the outermost layer, and the heat-sealable resin layer 4 is the innermost layer. When assembling an electrical storage device using the electrical storage device packaging material 10 and an electrical storage device element, the electrical storage device element is housed in a space formed by heat-sealing the peripheral portions of the electrical storage device packaging material 10 with the heat-sealable resin layers 4 of the electrical storage device packaging material 10 facing each other. In the laminate constituting the electrical storage device packaging material 10 according to the present disclosure, with the barrier layer 3 as the reference, the side of the heat-sealable resin layer 4 relative to the barrier layer 3 is on the inner side, and the side of the base material layer 1 relative to the barrier layer 3 is on the outer side.

[0022] As shown in, for example, FIGS. 2 and 4 to 6, the electrical storage device packaging material 10 may have an adhesive layer 2 between the base material layer 1 and the barrier layer 3, if necessary, for the purpose of increasing the adhesion between these layers (and further, as described below, coloring the electrical storage device packaging material 10). Furthermore, as shown in, for example, FIGS. 3 and 4, a colored layer 21 may be provided between the base material layer 1 and the barrier layer 3, if necessary, for the purpose of coloring the electrical storage device packaging material 10. Furthermore, as shown in, for example, FIGS. 5 and 6, an adhesive layer 5 may be provided between the barrier layer 3 and the heat-sealable resin layer 4, if necessary, for the purpose of increasing the adhesion between these layers. Furthermore, as shown in FIG. 6, a surface coating layer 6 or the like may be provided on the outer side of the base material layer 1 (the side opposite to the heat-sealable resin layer 4).

[0023] The thickness of the laminate constituting the electrical storage device packaging material 10 is not particularly limited, but from the viewpoints of cost reduction, improving energy density, etc., it is preferably about 180 μm or less, about 155 μm or less, or about 120 μm or less. Furthermore, from the viewpoint of maintaining the function of the electrical storage device packaging material to protect the electrical storage device elements, the thickness of the laminate constituting the electrical storage device packaging material 10 is preferably about 35 μm or more, about 45 μm or more, or about 60 μm or more. Furthermore, preferred ranges for the thickness of the laminate constituting the electrical storage device packaging material 10 include, 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, about 45 to 120 μm, about 60 to 180 μm, about 60 to 155 μm, and about 60 to 120 μm.

[0024] The packaging material 10 for an electricity storage device according to the present disclosure has a reflectivity of 10.0% or less, which is measured from the outside under the measurement conditions of an SCI method, a field of view of 10°, and a light source of F2. * a * b * b in color space * The value is -0.20 or less. * By setting the upper limit of the value to such a specific value, the exterior material for an electricity storage device that has a black appearance can be adjusted to a black that has a bluish hue that is the complementary color of yellow, and the identification mark printed on the surface exhibits excellent identification properties in a yellow room or under a yellow light source.

[0025] b * The value is not particularly limited, with the limit being -0.20 or less, but from the viewpoint of further improving the distinguishability and suitably recognizing that the appearance is black, it is preferably about -0.50 or less, more preferably about -0.80 or less. * The value is preferably about -5.00 or more, more preferably about -4.00 or more, even more preferably about -2.00 or more, and even more preferably about -1.50 or more. *Preferable ranges of the value include about -5.00 to -0.20, about -5.00 to -0.50, about -5.00 to -0.80, about -4.00 to -0.20, about -4.00 to -0.50, about -4.00 to -0.80, about -2.00 to -0.20, about -2.00 to -0.50, about -2.00 to -0.80, about -1.50 to -0.20, about -1.50 to -0.50, and about -1.50 to -0.80. * The value is particularly preferably about −1.50 to −0.80.

[0026] Furthermore, the packaging material 10 for an electricity storage device according to the present disclosure has a L of reflected light measured from the outside under measurement conditions of an SCI method, a field of view of 10°, and a light source F2. * a * b * a in color space * The value is preferably +0.20 or less, which further improves the distinguishability and allows the appearance to be suitably recognized as black.

[0027] a * From the viewpoint of further improving the distinguishability and suitably recognizing that the appearance is black, the value is more preferably about +0.10 or less, even more preferably about +0.04 or less, even more preferably about +0.02 or less, even more preferably about 0.00 or less, and even more preferably about -0.01 or less. * The value is preferably about -3.50 or more, more preferably about -3.00 or more, even more preferably about -2.00 or more, even more preferably about -0.50 or more, even more preferably about -0.30 or more, even more preferably about -0.15 or more, even more preferably about -0.10 or more. *Preferred ranges of values ​​are approximately -3.50 to +0.20, approximately -3.50 to +0.10, approximately -3.50 to +0.04, approximately -3.50 to +0.02, approximately -3.50 to 0.00, approximately -3.50 to -0.01, approximately -3.00 to +0.20, approximately -3.00 to +0.10, approximately -3.00 to +0.04, and approximately -3.00 to +0.02. degree, -3.00~0.00 degree, -3.00~-0.01 degree, -2.00~+0.20 degree, -2.00~+0.10 degree, -2.00~+0.04 degree, -2.0 0~+0.02, -2.00~0.00, -2.00~-0.01, -0.50~+0.20, -0.50~+0.10, -0.50~+0.0 4 degree, -0.50~+0.02 degree, -0.50~0.00 degree, -0.50~-0.01 degree, -0.30~+0.20 degree, -0.30~+0.10 degree, -0 .30~+0.04, -0.30~+0.02, -0.30~0.00, -0.30~-0.01, -0.15~+0.20, -0.15~+0 Examples include about 0.10, about -0.15 to +0.04, about -0.15 to +0.02, about -0.15 to 0.00, about -0.15 to -0.01, about -0.10 to +0.20, about -0.10 to +0.10, about -0.10 to +0.04, about -0.10 to +0.02, about -0.10 to 0.00, and about -0.10 to -0.01. * The values ​​are especially around -0.30 to -0.01, -0.10 to -0.01 The degree is preferable.

[0028] Furthermore, the packaging material 10 for an electricity storage device according to the present disclosure has a L of reflected light measured from the outside under measurement conditions of an SCI method, a field of view of 10°, and a light source F2. * a * b * L in color space * It is preferable that the value is 35.0 or less, which further improves the distinguishability and allows the appearance to be suitably recognized as black.

[0029] L *From the viewpoint of further improving the distinguishability and suitably recognizing the black appearance, the L value is more preferably about 33.0 or less, more preferably about 30.0 or less, and even more preferably about 28.0 or less. * The value is preferably about 25.0 or more, more preferably about 26.0 or more. * Preferred ranges of the value include about 25.0 to 35.0, about 25.0 to 33.0, about 25.0 to 30.0, about 25.0 to 28.0, about 26.0 to 35.0, about 26.0 to 33.0, about 26.0 to 30.0, and about 26.0 to 28.0. * The values ​​are especially around 25.0 to 30.0, 26.0 to 30.0, and even 26.0 It is preferably about 26.0 to 28.0.

[0030] <L * value, a * value and b * Value Measurement> In this disclosure, L * value, a * value and b * The values ​​of the values ​​are measured by the following method: For the exterior material for an electricity storage device, the observation conditions of a spectrophotometer (for example, CM-700d manufactured by Konica Minolta) calibrated with a white calibration cap (for example, CM-A177 manufactured by Konica Minolta) were set at 10°, the observation light source was set to F2, and the L value of the outer surface (base material layer side) was measured (JIS Z8722-2009). * , a * , b * Measurement is carried out at room temperature and normal humidity. Three points of each sample are measured, and the average value is taken as the measured value. In addition, the packaging material for an electricity storage device is taken from the electricity storage device, and L is * value, a * value, and b * When the packaging material for an electricity storage device is removed from the electricity storage device and measured, the top surface portion of the packaging material for an electricity storage device that has not been stretched by molding is the object of measurement.

[0031] In the exterior packaging material for an electricity storage device of the present disclosure and in an electricity storage device using the same, examples of the identification mark to be printed include letters and numbers indicating a lot number, barcodes, symbols, etc. The color of the ink used to print the identification mark (i.e., the color of the identification mark) is preferably white, as this provides excellent identification in the exterior packaging material for an electricity storage device of the present disclosure, which has a black appearance.

[0032] 2. Each layer that forms the exterior material for the energy storage device [Base material layer 1] In the present disclosure, the substrate layer 1 is a layer provided for the purpose of allowing the packaging material for an electricity storage device to function as a substrate. The substrate layer 1 is located on the outer layer side of the packaging material for an electricity storage device.

[0033] The material for forming the substrate layer 1 is not particularly limited as long as it has the function of a substrate, that is, at least insulating properties. The substrate layer 1 can be formed using, for example, a resin, which may contain an additive described later. For example, by blending an additive or a coloring agent described later into the substrate layer, the above-mentioned L * value, a * value and b * You can also adjust the value.

[0034] When the base layer 1 is formed of a resin, the base layer 1 may be, for example, a resin film formed of a resin, or may be formed by applying a resin. The resin film may be an unstretched film or a stretched film. Examples of stretched films include uniaxially stretched films and biaxially stretched films, with biaxially stretched films being preferred. Examples of stretching methods for forming biaxially stretched films include sequential biaxial stretching, inflation, and simultaneous biaxial stretching. Examples of methods for applying a resin include roll coating, gravure coating, and extrusion coating.

[0035] Examples of resins that form the base layer 1 include polyester, polyamide, polyolefin, epoxy resin, acrylic resin, fluororesin, polyurethane, silicone resin, and phenolic resin, as well as modified versions of these resins. The resin that forms the base layer 1 may also be a copolymer of these resins or a modified version of the copolymer. Furthermore, it may also be a mixture of these resins.

[0036] Of these, preferred resins for forming the base layer 1 include polyester and polyamide.

[0037] Specific examples of polyesters include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and copolymer polyesters. Examples of copolymer polyesters include copolymer polyesters in which ethylene terephthalate is the main repeating unit. Specific examples include copolymer polyesters in which ethylene terephthalate is the main repeating unit and is polymerized with ethylene isophthalate (hereinafter abbreviated as polyethylene (terephthalate / isophthalate)), polyethylene (terephthalate / adipate), polyethylene (terephthalate / sodium sulfoisophthalate), polyethylene (terephthalate / sodium isophthalate), polyethylene (terephthalate / phenyl-dicarboxylate), and polyethylene (terephthalate / decanedicarboxylate). These polyesters may be used alone or in combination of two or more.

[0038] 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; hexamethylenediamine-isophthalic acid-terephthalic acid copolymer polyamides such as nylon 6I, nylon 6T, nylon 6IT, and nylon 6I6T (where I represents isophthalic acid and T represents terephthalic acid), which contain structural units derived from terephthalic acid and / or isophthalic acid; and aromatic polyamides such as polyamide MXD6 (polymetaxylylene adipamide); alicyclic polyamides such as polyamide PACM6 (polybis(4-aminocyclohexyl)methane adipamide); polyamides copolymerized with a lactam component or an isocyanate component such as 4,4'-diphenylmethane diisocyanate; polyesteramide copolymers and polyetheresteramide copolymers, which are copolymers of copolymerized polyamides with polyesters or polyalkylene ether glycols; and polyamides such as copolymers of these copolymers. These polyamides may be used singly or in combination of two or more.

[0039] The base layer 1 preferably includes at least one of a polyester film, a polyamide film, and a polyolefin film, preferably includes at least one of a stretched polyester film, a stretched polyamide film, and a stretched polyolefin film, more preferably includes at least one of a stretched polyethylene terephthalate film, a stretched polybutylene terephthalate film, a stretched nylon film, and a stretched polypropylene film, and even more preferably includes at least one of a biaxially oriented polyethylene terephthalate film, a biaxially oriented polybutylene terephthalate film, a biaxially oriented nylon film, and a biaxially oriented polypropylene film.

[0040] 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 resin films are laminated with an adhesive or the like, or a laminate of resin films formed by co-extrusion of resins into two or more layers. Furthermore, a laminate of resin films formed by co-extrusion of resins into two or more layers may be used as the base material layer 1 without being stretched, or may be uniaxially or biaxially stretched to form the base material layer 1.

[0041] Specific examples of laminates of two or more resin films in the base layer 1 include laminates of polyester film and nylon film, laminates of two or more nylon films, and laminates of two or more polyester films. Preferably, laminates of stretched nylon film and stretched polyester film, laminates of two or more stretched nylon films, and laminates of two or more stretched polyester films are preferred. For example, when the base layer 1 is a laminate of two resin films, a laminate of polyester resin film and polyester resin film, a laminate of polyamide resin film and polyamide resin film, or a laminate of polyester resin film and polyamide resin film is preferred. A laminate of polyethylene terephthalate film and polyethylene terephthalate film, a laminate of nylon film and nylon film, or a laminate of polyethylene terephthalate film and nylon film is more preferred. Furthermore, when the base layer 1 is a laminate of two or more resin films, it is preferred that the polyester resin film be located as the outermost layer of the base layer 1, because polyester resins are less likely to discolor when an electrolyte solution adheres to their surface.

[0042] When the base layer 1 is a laminate of two or more resin film layers, the two or more resin film layers may be laminated via an adhesive. Examples of preferred adhesives include those similar to those exemplified for adhesive layer 2 described below. The method for laminating two or more resin film layers is not particularly limited, and known methods can be used, such as dry lamination, sandwich lamination, extrusion lamination, and thermal lamination, with dry lamination being preferred. When laminating using the dry lamination method, it is preferable to use a polyurethane adhesive as the adhesive. In this case, the thickness of the adhesive may be, for example, about 2 to 5 μm. Alternatively, an anchor coat layer may be formed on the resin film before lamination. Examples of the anchor coat layer include those similar to those exemplified for adhesive layer 2 described below. In this case, the thickness of the anchor coat layer may be, for example, about 0.01 to 1.0 μm.

[0043] Furthermore, additives such as lubricants, flame retardants, antiblocking agents, antioxidants, light stabilizers, tackifiers, and antistatic agents may be present on at least one of the surface and the interior of the base material layer 1. Only one type of additive may be used, or two or more types may be mixed and used.

[0044] In the present disclosure, from the viewpoint of improving the formability of the exterior material for an electrical storage device, it is preferable that a lubricant be present on the surface of the base layer 1. The lubricant is not particularly limited, but preferably an amide-based lubricant is used. Specific examples of amide-based lubricants include saturated fatty acid amides, unsaturated fatty acid amides, substituted amides, methylolamides, saturated fatty acid bisamides, unsaturated fatty acid bisamides, fatty acid ester amides, and aromatic bisamides. Specific examples of saturated fatty acid amides 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 substituted amides include N-oleyl palmitic 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 methylolamides include methylol stearic acid amide. Specific examples of saturated fatty acid bisamides include methylene bisstearic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide, ethylene bisstearic acid amide, ethylene bishydroxystearic acid amide, ethylene bisbehenic acid amide, hexamethylene bisstearic acid amide, hexamethylene bisbehenic acid amide, hexamethylene hydroxystearic acid amide, N,N'-distearyl adipamide, and N,N'-distearyl sebacic acid amide. Specific examples of unsaturated fatty acid bisamides include ethylene bisoleic acid amide, ethylene biserucic acid amide, hexamethylene bisoleic acid amide, N,N'-dioleyl adipamide, and N,N'-dioleyl sebacic acid amide. Specific examples of fatty acid ester amides include stearamidoethyl stearate. Specific examples of aromatic bisamides include m-xylylene bisstearic acid amide, m-xylylene bishydroxystearic acid amide, N,N'-distearyl isophthalic acid amide, etc. The lubricants may be used singly or in combination of two or more.

[0045] When a lubricant is present on the surface of the base layer 1, the amount of the lubricant is not particularly limited, but is preferably about 3 mg / m 2 or more, more preferably 4 to 15 mg / m 2 approximately, more preferably 5 to 14 mg / m 2 The degree of

[0046] The lubricant present on the surface of the base layer 1 may be a lubricant exuded from the resin that constitutes the base layer 1, or a lubricant applied to the surface of the base layer 1.

[0047] The thickness of the base layer 1 is not particularly limited as long as it functions as a base, but may be, for example, about 3 to 50 μm, and preferably about 10 to 35 μm. When the base layer 1 is a laminate of two or more resin films, the thickness of each resin film constituting each layer is preferably about 2 to 25 μm.

[0048] For example, when the adhesive layer is a layer colored black, the substrate layer located outside the adhesive layer is preferably transparent or translucent.

[0049] [Adhesive layer 2] In the packaging material for an electricity storage device of the present disclosure, the adhesive layer 2 is a layer that is provided between the base layer 1 and the barrier layer 3 as needed for the purpose of increasing the adhesion between them.

[0050] In the electrical storage device packaging material of the present disclosure, the adhesive layer 2 may be colored black. By coloring the adhesive layer 2 black, the electrical storage device packaging material has a black appearance, and then the b * However, if the adhesive layer 2 is colored black, the value of b can be suitably set to -0.20 or less. *By adjusting the composition of the adhesive layer 2, such as the type and content of the colorant, the composition of the substrate layer 1, and the layers positioned outside the barrier layer 3, such as the surface coating layer 6 and colored layer 21 that are provided as needed, and further the aging treatment conditions of the packaging material for an electricity storage device, which will be described later, it is possible to make the appearance of the packaging material for an electricity storage device black and achieve the above-mentioned b * The value can be set to -0.20 or less. * value and a * The same applies to setting values.

[0051] The adhesive layer 2 is formed from an adhesive capable of bonding the base material layer 1 and the barrier layer 3. There are no limitations on the adhesive used to form the adhesive layer 2, and it may be any of a chemical reaction type, a solvent evaporation type, a hot melt type, a hot pressure type, etc. It may also be a two-component curing adhesive (two-component adhesive), a one-component curing adhesive (one-component adhesive), or a resin that does not involve a curing reaction. The adhesive layer 2 may be a single layer or multiple layers.

[0052] Specific examples of adhesive components contained in the adhesive include polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and copolymer polyesters; polyethers; polyurethanes; epoxy resins; phenolic resins; polyamides such as nylon 6, nylon 66, nylon 12, and copolymer polyamides; polyolefin-based resins such as polyolefins, cyclic polyolefins, acid-modified polyolefins, and acid-modified cyclic polyolefins; polyvinyl acetate; cellulose; (meth)acrylic resins; polyimides; polycarbonates; amino resins such as urea resins and melamine resins; rubbers such as chloroprene rubber, nitrile rubber, and styrene-butadiene rubber; and silicone resins. These adhesive components may be used alone or in combination. Among these adhesive components, polyurethane adhesives are preferred. Furthermore, the adhesive strength of these adhesive component resins can be increased by using an appropriate curing agent in combination. The curing agent is selected appropriately from polyisocyanates, multifunctional epoxy resins, oxazoline group-containing polymers, polyamine resins, acid anhydrides, and the like, depending on the functional groups of the adhesive components.

[0053] Examples of polyurethane adhesives include polyurethane adhesives containing a base agent containing a polyol compound and a curing agent containing an isocyanate compound. Two-component curing polyurethane adhesives are preferred, using a polyol such as polyester polyol, polyether polyol, or acrylic polyol as the base agent and an aromatic or aliphatic polyisocyanate as the curing agent. Furthermore, polyester polyols having hydroxyl groups on the side chains in addition to terminal hydroxyl groups in the repeating units are preferred as polyol compounds. Examples of curing agents include aliphatic, alicyclic, aromatic, and araliphatic isocyanate compounds. Examples of isocyanate compounds include hexamethylene diisocyanate (HDI), xylylene diisocyanate (XDI), isophorone diisocyanate (IPDI), hydrogenated XDI (H6XDI), hydrogenated MDI (H12MDI), tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), and naphthalene diisocyanate (NDI). Further examples include polyfunctional isocyanate modified products obtained from one or more of these diisocyanates. Furthermore, a polymer (e.g., a trimer) can also be used as the polyisocyanate compound. Examples of such polymers include adducts, biurets, and nurates. The aliphatic isocyanate compound refers to an isocyanate having an aliphatic group but no aromatic ring, the alicyclic isocyanate compound refers to an isocyanate having an alicyclic hydrocarbon group, and the aromatic isocyanate compound refers to an isocyanate having an aromatic ring. The adhesive layer 2 is formed from a polyurethane adhesive, which provides the electrical storage device exterior material with excellent electrolyte resistance, thereby preventing the base layer 1 from peeling off even when the side surface is coated with an electrolyte.

[0054] Furthermore, the adhesive layer 2 may contain other components as long as they do not impair adhesion, and may contain colorants, thermoplastic elastomers, tackifiers, fillers, and the like. When the adhesive layer 2 contains a colorant, the exterior material for an electricity storage device can be colored. Known colorants such as pigments and dyes can be used as the colorant. Furthermore, only one type of colorant may be used, or two or more types may be mixed together.

[0055] The type of pigment is as described above in b * There are no particular limitations on the content, as long as the value is −0.20 or less and is within a range that does not impair the adhesiveness of the adhesive layer 2. Examples of organic pigments include azo-based, phthalocyanine-based, quinacridone-based, anthraquinone-based, dioxazine-based, indigothioindigo-based, perinone-perylene-based, isoindolenine-based, and benzimidazolone-based pigments, while examples of inorganic pigments include carbon black-based, titanium-based, titanium oxide-based, cadmium-based, lead-based, chromium oxide-based, and iron-based pigments, and other examples include finely powdered mica and fish scale foil.

[0056] The average particle size of the pigment is * There are no particular limitations as long as the value is -0.20 or less and the adhesiveness of the adhesive layer 2 is not impaired, and examples thereof include about 0.05 to 5 μm, and preferably about 0.08 to 2 μm. The average particle size of the pigment is the median diameter measured with a laser diffraction / scattering particle size distribution measuring device. If the primary particle size of the pigment changes, the L * value, a * value and b * For example, if the primary particle size of the black pigment increases, the black color may become slightly bluish. For this reason, in this disclosure, L * value, a * value and b *In setting the value, it is also preferable to adjust the primary particle diameter of the pigment used. The secondary particle diameter of the pigment is preferably about 0.8 μm or less, more preferably about 0.6 μm or less, and even more preferably about 0.4 μm or less. The secondary particle diameter of the pigment is preferably about 0.05 μm or more, more preferably about 0.1 μm or more. Preferred ranges for the secondary particle diameter of the pigment include 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, about 0.1 to 0.6 μm, and about 0.1 to 0.4 μm.

[0057] Among colorants, it is preferable to use a black agent in order to give the exterior material for an electrical storage device a black appearance. A black agent is an additive such as a pigment or dye that can be colored black, and is a black colorant. Examples of black agents include black pigments. Carbon and titanium-based pigments are preferred as black pigments. Black pigments made of carbon are generally called carbon black. Titanium black is preferred as a titanium-based pigment. Carbon black and titanium black may also be used as a mixture.

[0058] Furthermore, the appearance of the exterior material for the electricity storage device is made black, and * From the viewpoint of improving distinguishability by suitably setting the value to -0.20 or less, it is preferable that the adhesive layer 2 further contains a blue agent in addition to the black agent. A blue agent is an additive such as a pigment or dye that can be colored blue, and is a blue colorant. Examples of blue agents include dyes such as anthraquinone and indigoid, and pigments such as phthalocyanine, ultramarine, ferric ferrocyanide, and Prussian blue. Examples of phthalocyanines include copper phthalocyanine and metal-free phthalocyanine, with copper phthalocyanine being preferred. Copper phthalocyanine is known as a blue pigment.

[0059] When an analysis is performed by X-ray fluorescence spectroscopy (XRF) from the outside of the laminate constituting the electrical storage device packaging material of the present disclosure, Cu element is preferably detected. For example, when the adhesive layer 2 of the electrical storage device packaging material contains a copper-containing pigment (e.g., copper phthalocyanine) as the pigment, Cu element is detected when the analysis is performed by X-ray fluorescence spectroscopy (XRF) from the outside of the laminate. As described below, when the surface coating layer 6 or the colored layer 21 contains a copper-containing pigment (e.g., copper phthalocyanine), Cu element is also detected when the analysis is performed by X-ray fluorescence spectroscopy (XRF) from the outside. For detecting Cu element by X-ray fluorescence spectroscopy (XRF), the measurement conditions described in the examples can be used.

[0060] The content of the coloring agent in the adhesive layer 2 is such that the packaging material for an electricity storage device is colored black, and the above-mentioned b * The colorant content in the adhesive layer 2 is not particularly limited as long as the value is −0.20 or less, and from the viewpoint of appropriate coloring, it is preferably about 0.5% by mass or more, and more preferably about 1.0% by mass or more. Furthermore, from the viewpoint of appropriately maintaining the adhesion between the base layer 1 and the barrier layer 3, the content of the colorant in the adhesive layer 2 is preferably about 50.0% by mass or less, more preferably about 30.0% by mass or less, and even more preferably 20.0% by mass or less. Preferred ranges for the content of the colorant in the adhesive layer 2 include about 0.5 to 50.0% by mass, about 0.5 to 30.0% by mass, about 0.5 to 20.0% by mass, 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.

[0061] In addition, when a black agent is blended as a colorant in the adhesive layer 2, the content of the black agent in the adhesive layer 2 is such that the electrical storage device packaging material is colored black and the above-mentioned b *The content of the black agent in the adhesive layer 2 is not particularly limited as long as the value is −0.20 or less, and from the viewpoint of appropriate coloring, it is preferably about 0.5% by mass or more, more preferably about 1.0% by mass or more. Furthermore, from the viewpoint of appropriately maintaining adhesion between the base layer 1 and the barrier layer 3, the content of the black agent in the adhesive layer 2 is preferably about 50.0% by mass or less, more preferably about 30.0% by mass or less, and even more preferably 20.0% by mass or less. Preferred ranges for the content of the black agent in the adhesive layer 2 include about 0.5 to 50.0% by mass, about 0.5 to 30.0% by mass, about 0.5 to 20.0% by mass, 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. Furthermore, 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 electrical storage device packaging material is colored black, and is, for example, about 0.5 to 30% by mass, preferably 1 to 20% by mass.

[0062] Furthermore, when a black agent and a blue agent are blended into the adhesive layer 2, the ratio of the black agent to the blue agent in the adhesive layer 2 is preferably about 0.1 parts by mass or more, more preferably about 1 part by mass or more, and even more preferably about 10 parts by mass or more, based on 100 parts by mass of the black agent. The ratio of the blue agent is preferably about 150 parts by mass or less, more preferably about 100 parts by mass or less. Preferred ranges for the ratio of the blue agent are 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, and about 10 to 100 parts by mass. As mentioned above, the L can be adjusted by adjusting the primary particle size of the pigment used, the composition of the layer positioned outside the barrier layer 3, and the aging treatment conditions of the electrical storage device packaging material, which will be described later. * value, a * value and b * Since the value can be set, the adhesive layer 2 may contain only a black agent as a colorant, and may not contain, for example, a blue agent.

[0063] The thickness of the adhesive layer 2 is not particularly limited as long as it can bond the base layer 1 and the barrier layer 3, but is, for example, about 1 μm or more, or about 2 μm or more. The thickness of the adhesive layer 2 is, for example, about 10 μm or less, or about 5 μm or less. Preferred ranges for the thickness of the adhesive layer 2 include about 1 to 10 μm, about 1 to 5 μm, about 2 to 10 μm, and about 2 to 5 μm.

[0064] [Colored layer 21] The colored layer 21 is a layer that is provided, if necessary, between the base material layer 1 and the barrier layer 3. When the adhesive layer 2 is provided, the colored layer 21 may be provided at least either between the base material layer 1 and the adhesive layer 2 or between the adhesive layer 2 and the barrier layer 3. The colored layer 21 may also be provided on the outer side of the base material layer 1. By providing the colored layer 21, the packaging material for an electricity storage device can be suitably colored black.

[0065] In addition, in the packaging material for an electricity storage device according to the present disclosure, the colored layer 21 is colored black to provide a packaging material for an electricity storage device that has a black appearance, and * However, similarly to the case where the adhesive layer 2 is colored black, if the colored layer 21 is colored black, the value of b * By adjusting the composition of the coloring layer 21, such as the type and content of the coloring agent, the composition of the base material layer 1, and the layers positioned outside the barrier layer 3, such as the surface coating layer 6 and adhesive layer 2 that are provided as needed, and further the aging treatment conditions of the packaging material for an electricity storage device, which will be described later, it is possible to make the appearance of the packaging material for an electricity storage device black and achieve the above-mentioned b * The value can be set to -0.20 or less. * value and a * The same applies to setting values.

[0066] The colored layer 21 can be formed, for example, by applying ink containing a colorant to the surface of the base layer 1 or the surface of the barrier layer 3. Known colorants such as pigments and dyes can be used as the colorant. Furthermore, only one type of colorant may be used, or two or more types may be mixed together.

[0067] Specific examples of the colorant contained in the colored layer 21 include the same as those exemplified in the section [Adhesive layer 2].

[0068] The content of the coloring agent in the colored layer 21 is such that the packaging material for an electricity storage device is colored black, and the content of the coloring agent in the colored layer 21 is such that the content of the coloring agent in the packaging material for an electricity storage device is black, and the content of the coloring agent in the packaging material for an electricity storage device ... * The colorant content is not particularly limited as long as the value is -0.20 or less, and from the viewpoint of appropriate coloring, it is preferably about 0.5% by mass or more, more preferably about 1.0% by mass or more. Furthermore, from the viewpoint of appropriate formation of the colored layer 21, 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 even more preferably 20.0% by mass or less. Preferred ranges for the content of the colorant in the colored layer 21 include about 0.5 to 50.0% by mass, about 0.5 to 30.0% by mass, about 0.5 to 20.0% by mass, 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.

[0069] In addition, when a black agent is blended in the colored layer 21, the content of the black agent in the colored layer 21 is such that the electrical storage device packaging material is colored black and the above-mentioned b * The value is not particularly limited as long as it is -0.20 or less, and from the viewpoint of appropriate coloring, it is preferably about 0.5 mass% or more, more preferably about 1.0 mass% or more. Furthermore, from the viewpoint of appropriate formation of the colored layer 21, the content of the black agent in the colored layer 21 is preferably about 50.0 mass% or less, more preferably about 30.0 mass% or less, and even more preferably 20.0 mass% or less. Preferred ranges for the content of the black agent in the colored layer 21 include about 0.5 to 50.0 mass%, about 0.5 to 30.0 mass%, about 0.5 to 20.0 mass%, about 1.0 to 50.0 mass%, about 1.0 to 30.0 mass%, and about 1.0 to 20.0 mass%. Furthermore, when a blue agent is blended into the colored layer 21, the content of the blue agent in the colored layer 21 is not particularly limited as long as the electrical storage device exterior material is colored black, and is, for example, about 0.5 to 30 mass%, preferably 1 to 20 mass%.

[0070] Furthermore, when a black agent and a blue agent are blended into the colored layer 21, the ratio of the black agent to the blue agent in the colored layer 21 is preferably about 0.1 parts by mass or more, more preferably about 1 part by mass or more, and even more preferably about 10 parts by mass or more, based on 100 parts by mass of the black agent. Furthermore, the ratio of the blue agent is preferably about 150 parts by mass or less, more preferably about 100 parts by mass or less. The preferred ranges for the blue agent are 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, and about 10 to 100 parts by mass.

[0071] [Barrier layer 3] In the packaging material for an electricity storage device, the barrier layer 3 is a layer that at least prevents the penetration of moisture.

[0072] Examples of the barrier layer 3 include metal foils, vapor-deposited films, and resin layers having barrier properties. Vapor-deposited films include metal vapor-deposited films, inorganic oxide vapor-deposited films, and carbon-containing inorganic oxide vapor-deposited films. Resin layers include fluorine-containing resins such as polyvinylidene chloride, polymers mainly composed of chlorotrifluoroethylene (CTFE), polymers mainly composed of tetrafluoroethylene (TFE), polymers having fluoroalkyl groups, and polymers mainly composed of fluoroalkyl units, as well as ethylene-vinyl alcohol copolymers. Examples of the barrier layer 3 also include resin films comprising at least one of these vapor-deposited films and resin layers. The barrier layer 3 may comprise multiple layers. The barrier layer 3 preferably includes a layer composed of a metal material. Specific examples of metal materials constituting the barrier layer 3 include aluminum alloys, stainless steel, titanium steel, and steel plates. When used as a metal foil, the barrier layer 3 preferably includes at least one of aluminum alloy foil and stainless steel foil.

[0073] From the viewpoint of improving the formability of the electrical storage device packaging material, the aluminum alloy foil is preferably a soft aluminum alloy foil made of, for example, an annealed aluminum alloy, and from the viewpoint of further improving formability, an iron-containing aluminum alloy foil is preferred. In the iron-containing aluminum alloy foil (100% by mass), the iron content is preferably 0.1 to 9.0% by mass, more preferably 0.5 to 2.0% by mass. By setting the iron content to 0.1% by mass or more, an electrical storage device packaging material with better formability can be obtained. By setting the iron content to 9.0% by mass or less, an electrical storage device packaging material with better flexibility can be obtained. Examples of soft aluminum alloy foils include aluminum alloy foils having a composition specified in JIS H4160:1994 A8021H-O, JIS H4160:1994 A8079H-O, JIS H4000:2014 A8021P-O, or JIS H4000:2014 A8079P-O. Silicon, magnesium, copper, manganese, etc. may be added as needed. Softening can be achieved by annealing or other methods.

[0074] Examples of stainless steel foil include austenitic, ferritic, austenitic-ferritic, martensitic, and precipitation hardened stainless steel foils. From the viewpoint of providing an exterior material for an electricity storage device that has excellent formability, the stainless steel foil is preferably made of austenitic stainless steel.

[0075] Specific examples of austenitic stainless steels that can be used to form the stainless steel foil include SUS304, SUS301, and SUS316L, with SUS304 being particularly preferred.

[0076] In the case of a metal foil, the thickness of the barrier layer 3 should be sufficient to at least function as a barrier layer that prevents moisture penetration, and is, for example, approximately 9 to 200 μm. The thickness of the barrier layer 3 is preferably approximately 85 μm or less, more preferably approximately 50 μm or less, even more preferably approximately 40 μm or less, and particularly preferably approximately 35 μm or less. The thickness of the barrier layer 3 is preferably approximately 10 μm or more, even more preferably approximately 20 μm or more, and more preferably approximately 25 μm or more. Preferred thickness ranges include approximately 10 to 85 μm, approximately 10 to 50 μm, approximately 10 to 40 μm, approximately 10 to 35 μm, approximately 20 to 85 μm, approximately 20 to 50 μm, approximately 20 to 40 μm, approximately 20 to 35 μm, approximately 25 to 85 μm, approximately 25 to 50 μm, approximately 25 to 40 μm, and approximately 25 to 35 μm. When the barrier layer 3 is made of an aluminum alloy foil, the above-mentioned range is particularly preferred. Furthermore, particularly when the barrier layer 3 is made of a stainless steel foil, the thickness of the stainless steel foil is preferably about 60 μm or less, more preferably about 50 μm or less, even more preferably about 40 μm or less, even more preferably about 30 μm or less, and particularly preferably about 25 μm or less. Furthermore, the thickness of the stainless steel foil is preferably about 10 μm or more, more preferably about 15 μm or more. Furthermore, preferred thickness ranges for the stainless steel foil include 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, about 15 to 40 μm, about 15 to 30 μm, and about 15 to 25 μm.

[0077] Furthermore, when the barrier layer 3 is a metal foil, it is preferable that a corrosion-resistant coating be provided on at least the surface opposite the substrate layer to prevent dissolution and corrosion. The barrier layer 3 may be provided with a corrosion-resistant coating on both sides. Here, the corrosion-resistant coating refers to a thin film formed by applying, to the surface of the barrier layer, for example, a hydrothermal conversion treatment such as boehmite treatment, a chemical conversion treatment, anodizing treatment, a nickel or chromium plating treatment, or a corrosion prevention treatment such as applying a coating agent, to provide the barrier layer with corrosion resistance. The corrosion-resistant coating may be formed by one type of treatment or a combination of two or more types. Furthermore, not only one layer but also multiple layers can be formed. Furthermore, among these treatments, hydrothermal conversion treatment and anodizing treatment are treatments in which the metal foil surface is dissolved by a treatment agent to form a metal compound with excellent corrosion resistance. Note that these treatments may also be included in the definition of chemical conversion treatment. Furthermore, when the barrier layer 3 has a corrosion-resistant coating, the corrosion-resistant coating is also included in the barrier layer 3.

[0078] The corrosion-resistant coating prevents delamination between the barrier layer (e.g., aluminum alloy foil) and the substrate layer during molding of the exterior packaging material for an electricity storage device, prevents dissolution and corrosion of the barrier layer surface due to hydrogen fluoride produced by the reaction between the electrolyte and water, and in particular prevents dissolution and corrosion of aluminum oxide present on the barrier layer surface when the barrier layer is an aluminum alloy foil, and also improves the adhesion (wettability) of the barrier layer surface, thereby preventing delamination between the substrate layer and the barrier layer during heat sealing and between the substrate layer and the barrier layer during molding.

[0079] Various corrosion-resistant coatings formed by chemical conversion treatments are known, including corrosion-resistant coatings containing at least one of phosphates, chromates, fluorides, triazine thiol compounds, and rare earth oxides. Examples of chemical conversion treatments using phosphates and chromates include chromate chromate treatment, phosphate chromate treatment, phosphate-chromate treatment, and chromate treatment. Examples of chromium compounds used in these treatments include chromium nitrate, chromium fluoride, chromium sulfate, chromium acetate, chromium oxalate, chromium biphosphate, chromate acetylacetate, chromium chloride, and potassium chromium sulfate. Examples of phosphorus compounds used in these treatments include sodium phosphate, potassium phosphate, ammonium phosphate, and polyphosphoric acid. Examples of chromate treatments include etching chromate treatment, electrolytic chromate treatment, and paint-on chromate treatment, with paint-on chromate treatment being preferred. This paint-type chromate treatment involves first degreasing at least the inner surface of a barrier layer (e.g., an aluminum alloy foil) using a well-known method such as alkali immersion, electrolytic cleaning, acid pickling, electrolytic pickling, or acid activation, and then coating the degreased surface with a treatment solution primarily composed of a metal phosphate such as Cr (chromium) phosphate, Ti (titanium) phosphate, Zr (zirconium) phosphate, or Zn (zinc) phosphate, or a mixture of these metal salts, or a treatment solution primarily composed of a nonmetallic phosphate and a mixture of these nonmetallic salts, or a mixture of these with a synthetic resin, using a well-known coating method such as roll coating, gravure printing, or immersion, followed by drying. The treatment solution can be, for example, water, alcoholic solvents, hydrocarbon solvents, ketone solvents, ester solvents, or ether solvents, with water being preferred. The resin component used here may be a polymer such as a phenolic resin or an acrylic resin, or may be a chromate treatment using an aminated phenol polymer having repeating units represented by the following general formulas (1) to (4): 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 types.The acrylic resin is preferably polyacrylic acid, an acrylic acid methacrylic acid ester copolymer, an acrylic acid maleic acid copolymer, an acrylic acid styrene copolymer, or a derivative thereof such as a sodium salt, an ammonium salt, or an amine salt. A derivative of polyacrylic acid, such as an ammonium salt, a sodium salt, or an amine salt of polyacrylic acid, is particularly preferred. In the present disclosure, polyacrylic acid refers to a polymer of acrylic acid. The acrylic resin is also preferably a copolymer of acrylic acid and a dicarboxylic acid or a dicarboxylic acid anhydride, or an ammonium salt, a sodium salt, or an amine salt of a copolymer of acrylic acid and a dicarboxylic acid or a dicarboxylic acid anhydride. Only one type of acrylic resin may be used, or two or more types may be mixed and used.

[0080] [ka]

[0081] [ka]

[0082] [ka]

[0083] [ka]

[0084] In the general 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. 1 and R 2 are the same or different and represent a hydroxy group, an alkyl group, or a hydroxyalkyl group. 1 and R 2Examples of the alkyl group represented by X and R include linear or branched alkyl groups having 1 to 4 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and tert-butyl. 1 and R 2 Examples of the hydroxyalkyl group represented by the formula (1) include a linear or branched alkyl group having 1 to 4 carbon atoms substituted with one hydroxy group, such as a hydroxymethyl group, a 1-hydroxyethyl group, a 2-hydroxyethyl group, a 1-hydroxypropyl group, a 2-hydroxypropyl group, a 3-hydroxypropyl group, a 1-hydroxybutyl group, a 2-hydroxybutyl group, a 3-hydroxybutyl group, and a 4-hydroxybutyl group. 1 and R 2 The alkyl group and hydroxyalkyl group represented by the formula (1) may be the same or different. In the 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 repeating units represented by the formulas (1) to (4) is preferably about 500 to 1,000,000, and more preferably about 1,000 to 20,000. The aminated phenol polymer can be prepared, for example, by polycondensing a phenol compound or a naphthol compound with formaldehyde to produce a polymer comprising repeating units represented by the formula (1) or (3), and then polycondensing the polymer with formaldehyde and an amine (R 1 R 2 NH) to the functional group (-CHNR 1 R 2 The aminated phenol polymers can be used singly or in combination of two or more.

[0085] Another example of a corrosion-resistant coating is a thin film formed by a coating-type corrosion prevention treatment in which a coating agent containing at least one selected from the group consisting of a rare earth element oxide sol, an anionic polymer, and a cationic polymer is applied. The coating agent may further contain phosphoric acid or a phosphate salt, and a crosslinking agent for crosslinking the polymer. The rare earth element oxide sol has rare earth element oxide fine particles (e.g., particles with an average particle size of 100 nm or less) dispersed in a liquid dispersion medium. Examples of rare earth element oxides include cerium oxide, yttrium oxide, neodymium oxide, and lanthanum oxide, with cerium oxide being preferred from the perspective of further improving adhesion. The rare earth element oxide contained in the corrosion-resistant coating can be used alone or in combination of two or more. The liquid dispersion medium for the rare earth element oxide sol can be various solvents such as water, alcohol-based solvents, hydrocarbon-based solvents, ketone-based solvents, ester-based solvents, and ether-based solvents, with water being preferred. Preferred examples of cationic polymers include polyethyleneimine, ionic polymer complexes composed of polyethyleneimine and a polymer having a carboxylic acid, primary amine-grafted acrylic resins in which a primary amine is graft-polymerized onto an acrylic backbone, polyallylamine or its derivatives, and aminated phenols. Preferred anionic polymers are poly(meth)acrylic acid or its salts, or copolymers primarily composed of (meth)acrylic acid or its salts. The crosslinking agent is preferably at least one selected from the group consisting of a compound having a functional group selected from an isocyanate group, a glycidyl group, a carboxyl group, and an oxazoline group, and a silane coupling agent. The phosphoric acid or phosphoric acid salt is preferably a condensed phosphoric acid or a condensed phosphate salt.

[0086] An example of a corrosion-resistant coating is one formed by applying a solution of fine particles of metal oxides such as aluminum oxide, titanium oxide, cerium oxide, and tin oxide, or barium sulfate dispersed in phosphoric acid to the surface of a barrier layer and baking the coating at 150°C or higher.

[0087] The corrosion-resistant coating may have a laminated structure, if necessary, by further laminating at least one of a cationic polymer and an anionic polymer, such as those mentioned above.

[0088] The composition of the corrosion-resistant film can be analyzed using, for example, time-of-flight secondary ion mass spectrometry.

[0089] 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. For example, in the case of applying chromate treatment, the amount of the corrosion-resistant film formed on the surface of the barrier layer 3 is 2 It is desirable that the chromate compound is contained in an amount, in terms of chromium, of about 0.5 to 50 mg, preferably about 1.0 to 40 mg, the phosphorus compound in terms of phosphorus, and the aminated phenol polymer in an amount, in terms of phosphorus, of about 1.0 to 200 mg, preferably about 5.0 to 150 mg, per unit area.

[0090] The thickness of the corrosion-resistant coating is not particularly limited, but is preferably about 1 nm to 20 μm, more preferably about 1 nm to 100 nm, and even more preferably about 1 nm to 50 nm, from the viewpoint of the cohesive strength of the coating and the adhesive strength with the barrier layer or the thermally adhesive resin layer. The thickness of the corrosion-resistant coating can be measured by observation with a transmission electron microscope, or by a combination of observation with a transmission electron microscope and energy dispersive X-ray spectroscopy or electron energy loss spectroscopy. Analysis of the composition of the corrosion-resistant coating using time-of-flight secondary ion mass spectrometry can reveal the thickness of the corrosion-resistant coating, for example, by measuring the thickness of the coating with secondary ions consisting of Ce, P, and O (e.g., Ce2PO4 + , C ePO4 - At least one of the following ions may be present: Cr, P, and O secondary ions (e.g., CrPO2 + , CrPO4 - Peaks derived from at least one of the above are detected.

[0091] The chemical conversion treatment is carried out by applying a solution containing a compound used to form a corrosion-resistant coating to the surface of the barrier layer by bar coating, roll coating, gravure coating, immersion, or other methods, and then heating the barrier layer to a temperature of approximately 70 to 200°C. Furthermore, before applying the chemical conversion treatment to the barrier layer, the barrier layer may be subjected to a degreasing treatment using an alkali immersion method, electrolytic cleaning, acid cleaning, electrolytic acid cleaning, or other methods. By performing such a degreasing treatment, the chemical conversion treatment of the surface of the barrier layer can be carried out more efficiently. Furthermore, using an acid degreasing agent prepared by dissolving a fluorine-containing compound in an inorganic acid for the degreasing treatment not only degreases the metal foil but also forms a passive metal fluoride. In such cases, only the degreasing treatment may be performed.

[0092] [Thermal adhesive resin layer 4] In the packaging material for an electricity storage device of the present disclosure, the heat-sealable resin layer 4 corresponds to the innermost layer and is a layer (sealant layer) that functions to seal the electricity storage device elements by heat-sealing the heat-sealable resin layers together when the electricity storage device is assembled.

[0093] The resin constituting the heat-sealable resin layer 4 is not particularly limited as long as it is heat-sealable, but resins containing a polyolefin skeleton, such as polyolefin and acid-modified polyolefin, are preferred. The presence of a polyolefin skeleton in the resin constituting the heat-sealable resin layer 4 can be determined by, for example, infrared spectroscopy, gas chromatography mass spectrometry, or the like. Furthermore, when the resin constituting the heat-sealable resin layer 4 is analyzed by infrared spectroscopy, a peak derived from maleic anhydride is preferably detected. For example, when maleic anhydride-modified polyolefin is measured by infrared spectroscopy, a peak derived from maleic anhydride is detected at a wavenumber of 1760 cm. -1 Near and wave number 1780cm -1 A peak derived from maleic anhydride is detected around . When the thermally adhesive resin layer 4 is a layer made of 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 becomes small and may not be detected. In such cases, analysis can be performed by nuclear magnetic resonance spectroscopy.

[0094] Specific examples of polyolefins include polyethylenes such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene; ethylene-α-olefin copolymers; polypropylenes such as homopolypropylene, block copolymers of polypropylene (e.g., block copolymers of propylene and ethylene), and random copolymers of polypropylene (e.g., random copolymers of propylene and ethylene); propylene-α-olefin copolymers; and ethylene-butene-propylene terpolymers. Among 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.

[0095] The polyolefin may also be a cyclic polyolefin. Cyclic polyolefins are copolymers of olefins and cyclic monomers, and examples of olefins constituting the cyclic polyolefin include ethylene, propylene, 4-methyl-1-pentene, styrene, butadiene, and isoprene. Examples of cyclic monomers constituting the cyclic polyolefin include cyclic alkenes such as norbornene; and cyclic dienes such as cyclopentadiene, dicyclopentadiene, cyclohexadiene, and norbornadiene. Among these, preferred are cyclic alkenes, and more preferred are norbornene.

[0096] Acid-modified polyolefins are polymers modified by block polymerization or graft polymerization of polyolefins with an acid component. Examples of acid-modified polyolefins include the above-mentioned polyolefins, copolymers of the above-mentioned polyolefins with polar molecules such as acrylic acid or methacrylic acid, and crosslinked polyolefins. Examples of acid components used for acid modification include carboxylic acids or anhydrides thereof, such as maleic acid, acrylic acid, itaconic acid, crotonic acid, maleic anhydride, and itaconic anhydride.

[0097] The acid-modified polyolefin may be an acid-modified cyclic polyolefin. The acid-modified cyclic polyolefin is a polymer obtained by copolymerizing a part of the monomers constituting the cyclic polyolefin by replacing it with an acid component, or by block polymerizing or graft polymerizing an acid component onto the cyclic polyolefin. 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.

[0098] Preferred acid-modified polyolefins include polyolefins modified with carboxylic acid or its anhydride, polypropylenes modified with carboxylic acid or its anhydride, maleic anhydride-modified polyolefins, and maleic anhydride-modified polypropylenes.

[0099] The thermally adhesive resin layer 4 may be formed of one type of resin alone or may be formed of a blend polymer of two or more types of resins. Furthermore, the thermally adhesive resin layer 4 may be formed of only one layer, or may be formed of two or more layers of the same or different resins.

[0100] Furthermore, the heat-sealable resin layer 4 may contain a lubricant, etc., as necessary. When the heat-sealable resin layer 4 contains a lubricant, the moldability of the electrical storage device packaging material can be improved. The lubricant is not particularly limited, and known lubricants can be used. The lubricants may be used alone or in combination of two or more.

[0101] The lubricant is not particularly limited, but preferably an amide-based lubricant is used. Specific examples of the lubricant include those exemplified for the base layer 1. The lubricant may be used alone or in combination of two or more.

[0102] When a lubricant is present on the surface of the heat-sealable resin layer 4, the amount of the lubricant present is not particularly limited, but from the viewpoint of improving the formability of the packaging material for an electricity storage device, it is preferably 10 to 50 mg / m 2 about 15 to 40 mg / m 2 The degree of

[0103] The lubricant present on the surface of the heat-sealable resin layer 4 may be a lubricant exuded from the resin constituting the heat-sealable resin layer 4, or a lubricant applied to the surface of the heat-sealable resin layer 4.

[0104] The thickness of the heat-sealable resin layer 4 is not particularly limited as long as it can heat-seal the heat-sealable resin layers to each other and function to seal the electricity storage device element, but may be, for example, about 100 μm or less, preferably about 85 μm or less, and more preferably about 15 to 85 μm. For example, when the thickness of the adhesive layer 5 described below is 10 μm or more, the thickness of the heat-sealable resin layer 4 is preferably about 85 μm or less, and more preferably about 15 to 45 μm. For example, when the thickness of the adhesive layer 5 described below is less than 10 μm or when the adhesive layer 5 is not provided, the thickness of the heat-sealable resin layer 4 is preferably about 20 μm or more, and more preferably about 35 to 85 μm.

[0105] [Adhesive layer 5] In the packaging material for an electricity storage device of the present disclosure, the adhesive layer 5 is a layer that is optionally provided between the barrier layer 3 (or the corrosion-resistant coating (such as an acid-resistant coating)) and the heat-sealable resin layer 4 in order to firmly bond them together.

[0106] The adhesive layer 5 is formed from a resin capable of bonding the barrier layer 3 and the heat-sealable resin layer 4. The resin used to form the adhesive layer 5 can be, for example, the same adhesive as exemplified for the adhesive layer 2. The resin used to form the adhesive layer 5 preferably contains a polyolefin skeleton, such as the polyolefins and acid-modified polyolefins exemplified for the heat-sealable resin layer 4. The presence of a polyolefin skeleton in the resin constituting the adhesive layer 5 can be determined by, for example, infrared spectroscopy or gas chromatography-mass spectrometry, and the analysis method is not particularly limited. Furthermore, when the resin constituting the adhesive layer 5 is analyzed by infrared spectroscopy, a peak derived from maleic anhydride is preferably detected. For example, when a maleic anhydride-modified polyolefin is measured by infrared spectroscopy, a peak derived from maleic anhydride is detected at a wavenumber of 1760 cm. -1 Near and wave number 1780cm -1 A peak derived from maleic anhydride is detected around this point. However, if the degree of acid modification is low, the peak may be small and not be detected. In this case, analysis can be performed using nuclear magnetic resonance spectroscopy.

[0107] From the viewpoint of firmly bonding the barrier layer 3 and the heat-sealable resin layer 4, the adhesive layer 5 preferably contains an acid-modified polyolefin. Particularly preferred examples of the acid-modified polyolefin include polyolefins modified with carboxylic acid or its anhydride, polypropylenes modified with carboxylic acid or its anhydride, maleic anhydride-modified polyolefins, and maleic anhydride-modified polypropylenes.

[0108] Furthermore, from the viewpoint of reducing the thickness of the electrical storage device packaging material while providing an electrical storage device packaging material that has excellent shape stability after molding, the adhesive layer 5 is more preferably a cured product of a resin composition containing an acid-modified polyolefin and a curing agent. Preferred examples of the acid-modified polyolefin include those mentioned above.

[0109] The adhesive layer 5 is preferably 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 particularly preferably 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 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, more preferably polyurethane and epoxy resin. A preferred polyester is, for example, an amide ester resin. Amide ester resins are generally produced by the reaction of a carboxyl group with 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. In addition, if unreacted compounds of curing agents such as compounds having an isocyanate group, compounds having an oxazoline group, and epoxy resins remain in the adhesive layer 5, the presence of the unreacted compounds can be confirmed by a method selected from, for example, infrared spectroscopy, Raman spectroscopy, time-of-flight secondary ion mass spectrometry (TOF-SIMS), etc.

[0110] Furthermore, from the viewpoint of further enhancing the adhesion between the barrier layer 3 and the adhesive layer 5, the adhesive layer 5 is preferably a cured product of a resin composition containing a curing agent having at least one selected from the group consisting of an oxygen atom, a heterocycle, a C═N bond, and a COC bond. Examples of curing agents having a heterocycle include curing agents having an oxazoline group and curing agents having an epoxy group. Examples of curing agents having a C═N bond include curing agents having an oxazoline group and curing agents having an isocyanate group. Examples of curing agents having a COC bond include curing agents having an oxazoline group, curing agents having an epoxy group, and polyurethane. Whether the adhesive layer 5 is a cured product of a resin composition containing such a curing agent can be confirmed by, for example, gas chromatography mass spectrometry (GCMS), infrared spectroscopy (IR), time-of-flight secondary ion mass spectrometry (TOF-SIMS), X-ray photoelectron spectroscopy (XPS), or other methods.

[0111] The compound having an isocyanate group is not particularly limited, but from the viewpoint of effectively improving the adhesion between the barrier layer 3 and the adhesive layer 5, a polyfunctional isocyanate compound is preferably used. The polyfunctional isocyanate compound is not particularly limited as long as it is a compound having two or more isocyanate groups. Specific examples of polyfunctional isocyanate curing agents include pentane diisocyanate (PDI), isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), polymers or nurates thereof, mixtures of these, and copolymers with other polymers. Other examples include adducts, biuret compounds, and isocyanurates.

[0112] The content of the compound having an isocyanate group in the adhesive layer 5 is preferably in the range of 0.1 to 50 mass %, and more preferably in the range of 0.5 to 40 mass %, of the resin composition constituting the adhesive layer 5. This can effectively improve the adhesion between the barrier layer 3 and the adhesive layer 5.

[0113] 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 the Epocross series manufactured by Nippon Shokubai Co., Ltd.

[0114] The proportion of the compound having an oxazoline group in the adhesive layer 5 is preferably in the range of 0.1 to 50 mass %, and more preferably in the range of 0.5 to 40 mass %, in the resin composition constituting the adhesive layer 5. This can effectively improve the adhesion between the barrier layer 3 and the adhesive layer 5.

[0115] An example of a compound having an epoxy group is an epoxy resin. The epoxy resin is not particularly limited as long as it is a resin capable of forming a crosslinked structure by the epoxy groups present in the molecule, and known epoxy resins can be used. The weight-average molecular weight of the epoxy resin is preferably about 50 to 2,000, more preferably about 100 to 1,000, and even more 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) under conditions using polystyrene as a standard sample.

[0116] Specific examples of epoxy resins include glycidyl ether derivatives of trimethylolpropane, bisphenol A diglycidyl ether, modified bisphenol A diglycidyl ether, novolac glycidyl ether, glycerin polyglycidyl ether, polyglycerin polyglycidyl ether, etc. One type of epoxy resin may be used alone, or two or more types may be used in combination.

[0117] The proportion of the epoxy resin in the adhesive layer 5 is preferably in the range of 0.1 to 50 mass %, and more preferably in the range of 0.5 to 40 mass %, of the resin composition constituting the adhesive layer 5. This can effectively improve the adhesion between the barrier layer 3 and the adhesive layer 5.

[0118] The polyurethane is not particularly limited, and any known polyurethane can be used. The adhesive layer 5 may be, for example, a cured product of two-component curing polyurethane.

[0119] The proportion of polyurethane in adhesive layer 5 is preferably in the range of 0.1 to 50 mass %, and more preferably in the range of 0.5 to 40 mass %, of the resin composition constituting adhesive layer 5. This effectively improves the adhesion between barrier layer 3 and adhesive layer 5 in an atmosphere containing components that induce corrosion of the barrier layer, such as an electrolyte solution.

[0120] In addition, 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 the 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.

[0121] 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, or about 5 μm or less. The thickness of the adhesive layer 5 is preferably about 0.1 μm or more, or 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 50 μm, about 0.5 to 40 μm, about 0.5 to 30 μm, about 0.5 to 20 μm, or about 0.5 to 5 μm. More specifically, in the case of adhesives such as those exemplified for the adhesive layer 2 or a cured product of an acid-modified polyolefin and a curing agent, the thickness is preferably about 1 to 10 μm, more preferably about 1 to 5 μm. Furthermore, when a resin exemplified for the heat-fusible resin layer 4 is used, the thickness is preferably about 2 to 50 μm, more preferably about 10 to 40 μm. When the adhesive layer 5 is an adhesive exemplified for the adhesive layer 2 or a cured product of a resin composition containing an acid-modified polyolefin and a curing agent, the adhesive layer 5 can be formed, for example, by applying the resin composition and curing it by heating or the like. When a resin exemplified for the heat-fusible resin layer 4 is used, the heat-fusible resin layer 4 and the adhesive layer 5 can be formed, for example, by extrusion molding.

[0122] [Surface coating layer 6] The packaging material for an electricity storage device according to the present disclosure may have a surface coating layer 6 on the substrate layer 1 (the opposite side of the substrate layer 1 from the barrier layer 3) as needed, for the purpose of improving at least one of design, electrolyte resistance, scratch resistance, formability, etc. The surface coating layer 6 is a layer located on the outermost layer side of the packaging material for an electricity storage device when an electricity storage device is assembled using the packaging material for an electricity storage device. As described above, in the packaging material for an electricity storage device according to the present disclosure, the b * A value of -0.20 or less ensures excellent recognizability of the identification mark printed on the surface under a light source in a yellow room. However, although the electrical storage device packaging material may exhibit a slight blue color and visually detect color unevenness, when a surface coating layer 6 is provided on the outermost layer of the electrical storage device packaging material of the present disclosure, the surface coating layer has the effect of diffusing light and suppressing gloss, thereby suppressing the occurrence of color unevenness and improving the uniformity of appearance. On the other hand, when the outermost layer of the electrical storage device packaging material of the present disclosure does not have a surface coating layer 6, the surface gloss of the electrical storage device packaging material is high and scratches are easily noticeable. However, when a surface coating layer 6 is provided, the surface coating layer has the effect of diffusing light and suppressing gloss, thereby providing the advantage of making scratches less noticeable. These advantages are particularly easily exhibited when the surface coating layer 6 contains the additives (particularly matting agents) described below.

[0123] In addition, in the packaging material for an electricity storage device according to the present disclosure, the surface coating layer 6 is colored black to provide a packaging material for an electricity storage device that has a black appearance, and * However, similarly to the case where the adhesive layer 2 and the colored layer 21 are colored black, if the surface coating layer 6 is colored black, the value of b * By adjusting the composition of the surface coating layer 6, such as the type and content of the colorant, the composition of the base material layer 1, and the layers positioned outside the barrier layer 3, such as the adhesive layer 2 and colored layer 21 that are provided as needed, and further the aging treatment conditions of the packaging material for an electricity storage device, which will be described later, it is possible to make the appearance of the packaging material for an electricity storage device black and achieve the above-mentioned b * The value can be set to -0.20 or less.* value and a * The same applies to setting values.

[0124] The surface coating layer 6 can be formed from a resin such as polyvinylidene chloride, polyester, polyurethane, acrylic resin, or epoxy resin.

[0125] When the resin forming the surface coating layer 6 is a curable resin, the resin may be either a one-component curable resin or a two-component curable resin, but is preferably a two-component curable resin. Examples of two-component curable resins include two-component curable polyurethane, two-component curable polyester, and two-component curable epoxy resin. Among these, two-component curable polyurethane is preferred.

[0126] Examples of two-component curing polyurethanes include polyurethanes containing a polyol compound as a base component and an isocyanate compound as a curing agent. Preferred examples include two-component curing polyurethanes that use a polyol, such as polyester polyol, polyether polyol, or acrylic polyol, as the base component and an aromatic or aliphatic polyisocyanate as the curing agent. Furthermore, as the polyol compound, polyester polyols having hydroxyl groups on the side chains in addition to terminal hydroxyl groups in the repeating units are preferably used. Examples of curing agents include aliphatic, alicyclic, aromatic, and araliphatic isocyanate compounds. Examples of isocyanate compounds include hexamethylene diisocyanate (HDI), xylylene diisocyanate (XDI), isophorone diisocyanate (IPDI), hydrogenated XDI (H6XDI), hydrogenated MDI (H12MDI), tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), and naphthalene diisocyanate (NDI). Further examples include polyfunctional isocyanate modified products obtained from one or more of these diisocyanates. Furthermore, a polymer (e.g., a trimer) can also be used as the polyisocyanate compound. Examples of such polymers include adducts, biurets, and nurates. The surface coating layer 6 is formed from polyurethane, which provides the exterior material for an electricity storage device with excellent electrolyte resistance.

[0127] The surface coating layer 6 may contain additives such as the aforementioned lubricants, colorants, antiblocking agents, matting agents, flame retardants, antioxidants, tackifiers, and antistatic agents, as necessary, in at least one of the surface and interior of the surface coating layer 6, depending on the functionality to be imparted to the surface of the surface coating layer 6. Examples of additives include fine particles with an average particle size of approximately 0.5 nm to 5 μm. The average particle size of the additive is the median size measured with a laser diffraction / scattering particle size distribution analyzer.

[0128] The additive may be either inorganic or organic. The shape of the additive is not particularly limited, and examples thereof include spherical, fibrous, plate-like, amorphous, and scaly shapes.

[0129] Specific examples of additives 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, cross-linked acrylic, cross-linked styrene, cross-linked 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 distinguishability. Because calcium carbonate has a bluish tinge, its use as an additive to the surface coating layer can enhance the aforementioned b * The value can be suitably set to -0.20 or less. It is also preferable to use a mixture of silica and calcium carbonate as an additive. By using silica as an additive to the surface coating layer, it becomes easier to diffuse reflected light, and it becomes possible to make the appearance of the exterior material for an electricity storage device more bluish, and the above b * The value can be suitably set to -0.20 or less. Among these additives, silica, barium sulfate, and titanium oxide are preferred from the viewpoints of dispersion stability and cost. The additives may be subjected to various surface treatments such as insulation treatment and high-dispersion treatment.

[0130] When the surface coating layer 6 contains a colorant, known colorants such as pigments and dyes can be used. A single colorant may be used, or two or more colorants may be mixed. Specific examples of colorants contained in the surface coating layer 6 include those exemplified in the section [Adhesive layer 2]. The preferred content of the colorant contained in the surface coating layer 6 is also the same as that described in the section [Adhesive layer 2].

[0131] For example, when a black agent is blended into the surface coating layer 6, the content of the black agent in the surface coating layer 6 is not particularly limited as long as the electrical storage device packaging material is colored black, and may be, for example, about 5 to 60 mass %, and preferably 10 to 40 mass %. Furthermore, when a blue agent is blended into 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 electrical storage device packaging material is colored black, and may be, for example, about 0.5 to 30 mass %, and preferably 1 to 20 mass %.

[0132] Furthermore, for example, when a black agent and a blue agent are blended into the surface coating layer 6, the ratio of the black agent to the blue agent in the surface coating layer 6 is preferably about 0.1 parts by mass or more, more preferably about 1 part by mass or more, and even more preferably about 10 parts by mass or more, based on 100 parts by mass of the black agent. The ratio of the blue agent is preferably about 150 parts by mass or less, more preferably about 100 parts by mass or less. The preferred ranges for the blue agent are 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, and about 10 to 100 parts by mass.

[0133] The method for forming the surface coating layer 6 is not particularly limited, and examples thereof include a method of applying a resin to form the surface coating layer 6. When an additive is blended into the surface coating layer 6, a resin mixed with the additive may be applied.

[0134] The thickness of the surface coating layer 6 is not particularly limited as long as the surface coating layer 6 exhibits the above-mentioned functions, and may be, for example, about 0.5 to 10 μm, and preferably about 1 to 5 μm.

[0135] 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.

[0136] 3. Manufacturing method for exterior materials for power storage devices The method for producing an electrical storage device exterior material is not particularly limited as long as it can produce a laminate in which the layers of the electrical storage device exterior material of the present disclosure are laminated, and examples include a method comprising a step of laminating at least a base material layer 1, a barrier layer 3, and a heat-sealable resin layer 4 in this order. Specifically, the method for producing an electrical storage device exterior material of the present disclosure is a method for producing an electrical storage device exterior material that has a black appearance, and comprises a step of obtaining a laminate in which at least a base material layer, a barrier layer, and a heat-sealable resin layer are laminated in this order from the outside, and the L of reflected light measured from the outside of the laminate under measurement conditions of an SCI method, a field of view of 10°, and a light source F2, is * a * b * b in color space * The value is less than or equal to -0.20.

[0137] An example of a method for manufacturing an exterior material for an electricity storage device according to the present disclosure is as follows: First, a laminate (hereinafter, sometimes referred to as "laminate A") is formed in which a base layer 1, an adhesive layer 2, and a barrier layer 3 are laminated in this order. Specifically, laminate A can be formed by a dry lamination method in which an adhesive used to form adhesive layer 2 is applied to base layer 1 or to barrier layer 3, the surface of which has been chemically treated as necessary, by a coating method such as gravure coating or roll coating, and then dried, followed by laminating the barrier layer 3 or base layer 1 and curing the adhesive layer 2.

[0138] Next, a heat-sealable resin layer 4 is laminated on the barrier layer 3 of the laminate A. When the heat-sealable resin layer 4 is laminated directly on the barrier layer 3, the heat-sealable resin layer 4 may be laminated on the barrier layer 3 of the laminate A by a method such as thermal lamination or extrusion lamination. When an adhesive layer 5 is provided between the barrier layer 3 and the heat-sealable resin layer 4, for example, (1) a method of laminating the adhesive layer 5 and the heat-sealable resin layer 4 by extruding them onto the barrier layer 3 of the laminate A (co-extrusion lamination, tandem lamination), (2) a method of separately forming a laminate in which the adhesive layer 5 and the heat-sealable resin layer 4 are laminated, and laminating this on the barrier layer 3 of the laminate A by a thermal lamination, or a method of forming a laminate in which the adhesive layer 5 is laminated on the barrier layer 3 of the laminate A, and laminating this on the heat-sealable resin layer 4 by a thermal lamination. (3) a method (sandwich lamination method) in which a molten adhesive layer 5 is poured between the barrier layer 3 of the laminate A and a heat-sealable resin layer 4 previously formed into a sheet, and the laminate A and the heat-sealable resin layer 4 are bonded together via the adhesive layer 5; (4) a method in which an adhesive for forming the adhesive layer 5 is solution-coated on the barrier layer 3 of the laminate A, followed by drying or baking, and then the heat-sealable resin layer 4 previously formed into a sheet is laminated on the adhesive layer 5.

[0139] 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 for 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 the surface coating layer 6 is formed 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.

[0140] As described above, a laminate is formed which includes, from the outside, an optional surface coating layer 6 / a substrate layer 1 / an optional adhesive layer 2 / a barrier layer 3 / an optional adhesive layer 5 / a heat-sealable resin layer 4. In order to strengthen the adhesion of the optional adhesive layer 2 and adhesive layer 5, the laminate may be further subjected to a heat treatment.

[0141] In the packaging material for an electricity storage device, each layer constituting the laminate may be subjected to a surface activation treatment such as corona treatment, blast treatment, oxidation treatment, ozone treatment, etc., as needed to improve processability. For example, by subjecting the surface of the base layer 1 opposite to the barrier layer 3 to corona treatment, the printability of ink on the surface of the base layer 1 can be improved.

[0142] The packaging material for an electricity storage device is preferably subjected to aging treatment after laminating each layer. By changing the aging treatment conditions of the packaging material for an electricity storage device, it is possible to obtain a black-colored packaging material for an electricity storage device. * value, a * value, and b * The value can be changed. * value, a * value, and b * It is preferable to select the aging treatment conditions in order to adjust the value. Adjustment items for the aging treatment conditions include, for example, the rate of temperature rise, heating temperature, heating time, whether or not pretreatment is performed, and the temperature thereof. Note that the L * value, a * value, and b * The main reason for the change in value is that the degree of aggregation of the colorant contained in the packaging material for an electricity storage device changes depending on the aging treatment conditions.

[0143] 4. Applications of exterior materials for energy storage devices The exterior packaging material for an electricity storage device according to the present disclosure is used in a package for hermetically housing an electricity storage device element such as a positive electrode, a negative electrode, an electrolyte, etc. That is, an electricity storage device can be formed by housing an electricity storage device element including at least a positive electrode, a negative electrode, and an electrolyte in a package formed from the exterior packaging material for an electricity storage device according to the present disclosure.

[0144] Specifically, an electricity storage device using the electricity storage device packaging material is provided by covering an electricity storage device element having at least a positive electrode, a negative electrode, and an electrolyte with the electricity storage device packaging material of the present disclosure in a state in which metal terminals connected to each of the positive electrode and the negative electrode protrude outward, so that a flange portion (a region where the heat-sealable resin layers contact each other) can be formed around the periphery of the electricity storage device element, and heat-sealing the heat-sealable resin layers of the flange portion to form a hermetic seal. Note that when an electricity storage device element is housed in a package formed from the electricity storage device packaging material of the present disclosure, the package is formed so that the heat-sealable resin portion of the electricity storage device packaging material of the present disclosure faces inside (the surface in contact with the electricity storage device element).

[0145] The exterior material for an electricity storage device according to the present disclosure can be suitably used in electricity storage devices such as batteries (including condensers, capacitors, etc.). The exterior material for an electricity storage device according to the present disclosure may be used in either primary or secondary batteries, but is preferably used in secondary batteries. The type of secondary battery to which the exterior material for an electricity storage device according to the present disclosure is applied is not particularly limited, and examples include lithium ion batteries, lithium ion polymer batteries, all-solid-state batteries, lead-acid batteries, nickel-metal hydride batteries, nickel-cadmium batteries, nickel-iron batteries, nickel-zinc batteries, silver oxide-zinc batteries, metal-air batteries, polyvalent cation batteries, condensers, and capacitors. Among these secondary batteries, lithium ion batteries and lithium ion polymer batteries are suitable applications for the exterior material for an electricity storage device according to the present disclosure. [Example]

[0146] The present disclosure will be described in detail below with reference to examples and comparative examples, but the present disclosure is not limited to the examples.

[0147] <Manufacturing of exterior materials for electricity storage devices> Examples 1-7, 14, 15 and Comparative Example 1 An oriented nylon (ONy) film (thickness: 15 μm) was prepared as the substrate layer. Furthermore, an aluminum foil (JIS H4160:1994 A8021H-O (thickness: 35 μm)) was prepared as the barrier layer. Next, the barrier layer and the substrate layer were laminated by dry lamination using the adhesive (a two-component urethane adhesive containing a colorant) described below, and then aging treatment was performed to produce a substrate layer / adhesive layer / barrier layer laminate. Both sides of the aluminum foil were subjected to chemical conversion treatment. The chemical conversion treatment of the aluminum foil was performed by applying a treatment solution consisting of a phenolic resin, a chromium fluoride compound, and phosphoric acid to a coating amount of chromium of 10 mg / m. 2 (Dry The coating was applied to both sides of an aluminum foil by roll coating so that the coating amount was 100% (dry weight) and then baked.

[0148] Next, maleic anhydride-modified polypropylene as an adhesive layer (20 μm thick) and random polypropylene as a heat-sealable resin layer (20 μm thick) were co-extruded onto the barrier layer of each laminate obtained above, thereby laminating an adhesive layer / heat-sealable resin layer on the barrier layer. Furthermore, a resin composition containing silica particles (a polyurethane resin formed from a mixture of a polyol compound and an isocyanate compound) was applied to the surface of the substrate layer of the obtained laminate to a thickness of 3 μm to form a matte surface coating layer, thereby obtaining a laminate (total thickness 96 μm) in the following order from the outside: surface coating layer (3 μm) / substrate layer (15 μm thick) / adhesive layer (3 μm) / barrier layer (35 μm) / adhesive layer (20 μm) / heat-sealable resin layer (20 μm).

[0149] Example 8 In Example 1, a laminate (total thickness 93 μm) having a substrate layer (thickness 15 μm) / adhesive layer (3 μm) / barrier layer (35 μm) / adhesive layer (20 μm) / thermally adhesive resin layer (20 μm) laminated therein was obtained in the same manner as in Example 1, except that the surface coating layer was not formed.

[0150] Example 9 In Example 3, a laminate (total thickness 93 μm) having a substrate layer (thickness 15 μm) / adhesive layer (3 μm) / barrier layer (35 μm) / adhesive layer (20 μm) / thermally adhesive resin layer (20 μm) laminated therein was obtained in the same manner as in Example 3, except that the surface coating layer was not formed.

[0151] Example 10 In Example 4, a laminate (total thickness 93 μm) having a substrate layer (thickness 15 μm) / adhesive layer (3 μm) / barrier layer (35 μm) / adhesive layer (20 μm) / thermally adhesive resin layer (20 μm) laminated therein was obtained in the same manner as in Example 4, except that the surface coating layer was not formed.

[0152] Example 11 In Example 5, a laminate (total thickness 93 μm) having a substrate layer (thickness 15 μm) / adhesive layer (3 μm) / barrier layer (35 μm) / adhesive layer (20 μm) / thermally adhesive resin layer (20 μm) laminated therein was obtained in the same manner as in Example 5, except that the surface coating layer was not formed.

[0153] Example 12 In Example 2, a laminate (total thickness 93 μm) having a substrate layer (thickness 15 μm) / adhesive layer (3 μm) / barrier layer (35 μm) / adhesive layer (20 μm) / thermal adhesive resin layer (20 μm) laminated therein was obtained in the same manner as in Example 2, except that the surface coating layer was not formed.

[0154] Examples 13, 16-20 In Example 1, a laminate (total thickness 93 μm) having a substrate layer (thickness 15 μm) / adhesive layer (3 μm) / barrier layer (35 μm) / adhesive layer (20 μm) / thermally adhesive resin layer (20 μm) laminated therein was obtained in the same manner as in Example 1, except that no surface coating layer was formed and that adhesives B and C4 to C8 listed in Table 1 were used instead of adhesive A as the adhesive used to form the adhesive layer.

[0155] <Adhesive> The following adhesives were used to form the adhesive layer between the substrate layer and the barrier layer. The types of adhesives used in each example and comparative example are shown in Table 1. [Adhesive A] Two-component urethane adhesive (a mixture of polyol compounds and aromatic isocyanate compounds) containing carbon black (secondary particle diameter 0.2 μm) as a blackening agent [Adhesive B] A two-component urethane adhesive (a mixture of polyol compounds and aromatic isocyanate compounds) containing carbon black (secondary particle diameter 0.2 μm) with a larger primary particle diameter than the carbon black contained in adhesive A as the blackening agent. [Adhesive C1] The black agent used was the same carbon black as that contained in Adhesive A. A two-component urethane adhesive (a mixture of a polyol compound and an aromatic isocyanate compound) containing 26 parts by mass of carbon black and 4 parts by mass of copper phthalocyanine as a blue agent was used. [Adhesive C2] The black agent used was the same carbon black as that contained in Adhesive A. A two-component urethane adhesive (a mixture of a polyol compound and an aromatic isocyanate compound) containing 15 parts by mass of copper phthalocyanine as a blue agent for 15 parts by mass of carbon black. [Adhesive C3] The black agent used was the same carbon black as that contained in Adhesive A. A two-component urethane adhesive (a mixture of a polyol compound and an aromatic isocyanate compound) containing 13 parts by mass of carbon black and 17 parts by mass of copper phthalocyanine as a blue agent was used. [Adhesive C4] The black agent used was the same carbon black as that contained in Adhesive A. A two-component urethane adhesive (a mixture of a polyol compound and an aromatic isocyanate compound) containing 20 parts by mass of carbon black and 10 parts by mass of copper phthalocyanine as a blue agent was used. [Adhesive C5] The black agent used was the same carbon black as that contained in Adhesive A. A two-component urethane adhesive (a mixture of a polyol compound and an aromatic isocyanate compound) containing 18 parts by mass of carbon black and 12 parts by mass of copper phthalocyanine as a blue agent was used. [Adhesive C6] The black agent used was the same carbon black as that contained in Adhesive A. A two-component urethane adhesive (a mixture of a polyol compound and an aromatic isocyanate compound) containing 22 parts by mass of carbon black and 8 parts by mass of copper phthalocyanine as a blue agent was used. [Adhesive C7] The black agent used was the same carbon black as that contained in Adhesive A. A two-component urethane adhesive (a mixture of a polyol compound and an aromatic isocyanate compound) containing 16 parts by mass of carbon black and 14 parts by mass of copper phthalocyanine as a blue agent was used. [Adhesive C8] The black agent used was the same carbon black as that contained in Adhesive A. A two-component urethane adhesive (a mixture of a polyol compound and an aromatic isocyanate compound) containing 14 parts by mass of carbon black and 16 parts by mass of copper phthalocyanine as a blue agent was used.

[0156] <Aging treatment conditions> The aging treatment conditions used to adjust the color observed from the outside for the exterior packaging materials for an electricity storage device produced in each of the Examples and Comparative Examples are as follows. [Condition A] Leave it in an 80℃ environment for 12 hours. [Condition B] First, in step 1, the sample is left to stand at room temperature (approximately 25°C) for 3 hours. Next, in step 2, the sample is left to stand in a 55°C environment for 3 hours. Next, in step 3, the sample is left to stand in an 80°C environment for 12 hours. [Condition C] Leave it in an environment of 60 to 100°C for 3 days.

[0157] <L * value, a * value and b * Value Measurement> For the exterior packaging materials for electricity storage devices obtained in each of the Examples and Comparative Examples, the observation conditions of a spectrophotometer (CM-700d) manufactured by Konica Minolta, calibrated with a white calibration cap (CM-A177: manufactured by Konica Minolta), were set at 10°, the observation light source was set to F2, and the L of the outer (base material layer side) surface was measured (JIS Z8722-2009). * , a * , b * Measurements were carried out at room temperature and humidity. Three measurements were taken for each sample, and the average values ​​are shown in Table 1 as evaluation results.

[0158] <Measurement of Cu element by X-ray fluorescence spectrometry (XRF)> The presence or absence of detection of Cu element was confirmed by X-ray fluorescence analysis (XRF) under the following measurement conditions for the packaging materials for electricity storage devices obtained in Examples 1 to 5 and Comparative Example 1. As a result, no peaks derived from Cu element were detected in Examples 1 and 2 and Comparative Example 1. Furthermore, peaks derived from Cu element were detected in Examples 3, 4, and 5. The CuKα peak intensity was 0.4 in Example 3, 1.2 in Example 4, and 1.2 in Example 5. (Measurement conditions) Equipment used: EDX-800HS (Shimadzu Corporation) X-ray: Rh target Voltage: 50kV Current: 1000μA Irradiation area: 100φ Measurement time: 100 seconds Measurement atmosphere: vacuum Measurement surface: Outside (X-rays are irradiated onto the outside of the exterior material for the energy storage device) Analysis method: Automatic intensity calculation is performed using the software "PCEDX" attached to the EDX-800HS (Shimadzu Corporation). Specifically, peak detection is performed on the spectrum obtained by measurement. The coefficient of the peak detection condition is set to 10. Next, the detected intensity of the detected peak is calculated using intensity calculation.

[0159] <Distinguishing ability in the yellow room> The surface of the surface coating layer of the exterior materials for energy storage devices obtained in each Example and Comparative Example was printed with an inkjet printer (Model 9040, manufactured by Markem-Image Co., Ltd.) to create a sample: the number string "0123456789," with a dot diameter of approximately 0.3 mm and a string height of approximately 1.5 mm. The ink used for printing was white. Next, each sample was observed with the naked eye from a distance of 30 cm in a yellow room, and its distinguishability was evaluated according to the following evaluation criteria. The results are shown in Table 1. (Evaluation criteria) A: Immediately recognizable B: It takes a few seconds to recognize C: The sample can be recognized by changing the angle.

[0160] <Black exterior> Each sample prepared in the above "Distinguishing ability in a yellow room" was observed with the naked eye in a room under fluorescent lighting and evaluated for whether its appearance was recognized as black according to the following evaluation criteria. The results are shown in Table 1. (Evaluation criteria) A: It is clearly recognized as black. B: A slight blue or red color is detected, but the color is recognized as black without any problems. C: Blue or red is clearly recognized, and there is a risk that it will not be recognized as black.

[0161] [Table 1]

[0162] As is clear from the results shown in Table 1, the packaging materials for electricity storage devices of Examples 1 to 20 had a low L of reflected light measured from the outside under the measurement conditions of the SCI method, a field of view of 10°, and a light source of F2. * a * b * b in color space * Since the value was -0.20 or less, it can be seen that, despite the electrical storage device packaging materials having a black appearance, the identification marks printed on the surfaces were excellent in the identification of the identification marks printed on the surfaces in a yellow room. The electrical storage device packaging materials of Examples 1 to 20 had excellent identification of the identification marks printed on the surfaces not only in a yellow room but also indoors under ordinary fluorescent lighting. Furthermore, the electrical storage device packaging materials of Examples 1 to 20 could be recognized without any problem as having a black appearance indoors under ordinary fluorescent lighting.

[0163] As described above, the present disclosure provides the following aspects of the invention. Item 1. An exterior packaging material for an electricity storage device that has a black appearance, the electrical storage device packaging material is composed of a laminate including, in order from the outside, at least a base layer, a barrier layer, and a heat-sealable resin layer; The L of reflected light measured from the outside of the laminate under the measurement conditions of SCI method, field of view 10° and light source F2 * a * b * b in color space * An exterior material for an electricity storage device, wherein the value is -0.20 or less. Item 2. The L of reflected light measured from the outside of the laminate under the measurement conditions of SCI method, field of view 10° and light source F2 * a * b * a in color space * Item 2. The packaging material for an electricity storage device according to Item 1, wherein the value is +0.2 or less. Item 3. An adhesive layer is provided between the base layer and the barrier layer, Item 3. The electrical storage device packaging material according to Item 1 or 2, wherein the adhesive layer contains a colorant. Item 4. A colored layer is provided between the substrate layer and the barrier layer, Item 4. The packaging material for an electricity storage device according to any one of items 1 to 3, wherein the colored layer contains a pigment. Item 5. The packaging material for an electricity storage device according to any one of Items 1 to 4, further comprising a surface coating layer on the side of the base layer opposite to the barrier layer side. Item 6. The packaging material for an electricity storage device according to any one of Items 1 to 5, wherein elemental Cu is detected when the laminate is analyzed from the outside by fluorescent X-ray analysis. Item 7. A method for producing an exterior material for an electricity storage device that has a black appearance, The method includes a step of obtaining a laminate in which at least a base layer, a barrier layer, and a thermally adhesive resin layer are laminated in this order from the outside, The L of reflected light measured from the outside of the laminate under the measurement conditions of SCI method, field of view 10° and light source F2 * a * b * b in color space * A method for producing an exterior material for an electricity storage device, wherein the value is −0.20 or less. Item 8. 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 from the exterior packaging material for an electricity storage device according to any one of Items 1 to 6. [Explanation of symbols]

[0164] 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 materials for energy storage devices

Claims

1. An exterior material for an electricity storage device that has a black appearance, the electrical storage device packaging material is composed of a laminate including, in order from the outside, at least a surface coating layer, a base material layer, a barrier layer, and a heat-sealable resin layer; The L of reflected light measured from the outside of the laminate under the measurement conditions of SCI method, field of view 10° and light source F2 * a * b * b in color space * The value is equal to or greater than −5.00 and equal to or less than −0.20, L of the reflected light * a * b * a in color space * The value is equal to or greater than −3.50 and equal to or less than +0.20, L of the reflected light * a * b * L in color space * The outer packaging material for an electricity storage device has a value of 40 or less.

2. The packaging material for an electricity storage device according to claim 1 , wherein the surface coating layer contains titanium oxide.

3. The packaging material for an electricity storage device according to claim 1 , wherein the surface coating layer contains silica.

4. The packaging material for an electricity storage device according to claim 1 , wherein the surface coating layer contains kaolin.

5. an adhesive layer is provided between the substrate layer and the barrier layer, The packaging material for an electricity storage device according to any one of claims 1 to 4, wherein the adhesive layer contains a colorant.

6. a colored layer is provided between the substrate layer and the barrier layer, The packaging material for an electricity storage device according to any one of claims 1 to 4, wherein the colored layer contains a pigment.

7. The packaging material for an electricity storage device according to any one of claims 1 to 6, further comprising an adhesive layer between the barrier layer and the heat-sealable resin layer.

8. The packaging material for an electricity storage device according to claim 7 , wherein the adhesive layer has a thickness of 5 μm or less.

9. The packaging material for an electricity storage device according to claim 7 or 8, wherein the adhesive layer has a thickness of 0.1 μm or more.

10. The packaging material for an electricity storage device according to any one of claims 1 to 9, wherein the barrier layer comprises a metal foil and a resin layer.

11. A method for producing an exterior material for an electricity storage device having a black appearance, obtaining the electrical storage device packaging material comprising a laminate including, in order from the outside, at least a surface coating layer, a base material layer, a barrier layer, and a thermally adhesive resin layer; The L of reflected light measured from the outside of the laminate under the measurement conditions of SCI method, field of view 10° and light source F2 * a * b * b in color space * The value is equal to or greater than −5.00 and equal to or less than −0.20, L of the reflected light * a * b * a in color space * The value is equal to or greater than −3.50 and equal to or less than +0.20, L of the reflected light * a * b * L in color space * The method for producing an exterior material for an electricity storage device, wherein the value is 40 or less.

12. The method for producing an exterior packaging material for an electricity storage device according to claim 11 , further comprising providing an adhesive layer between the barrier layer and the heat-sealable resin layer.

13. The method for producing an exterior packaging material for an electricity storage device according to claim 12 , wherein the adhesive layer and the heat-fusible resin layer are laminated by a co-extrusion lamination method.

14. The method for producing an exterior packaging material for an electricity storage device according to claim 12 , wherein the adhesive layer and the heat-fusible resin layer are laminated by a thermal lamination method.

15. The method for producing an exterior packaging material for an electricity storage device according to claim 12 , wherein the adhesive layer and the heat-fusible resin layer are laminated by a sandwich lamination method.

16. 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 from the exterior packaging material for an electricity storage device according to any one of claims 1 to 10.

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