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 exhibits excellent moldability despite being provided with excellent scratch resistance by a scratch-resistant layer.SOLUTION: An exterior material for a power storage device is composed of a laminate including at least a scratch-resistant layer, a base material protection layer, a base material layer, a barrier layer, and a heat-fusible resin layer in this order, the scratch-resistant layer includes inorganic particles and resin, and the combined average thickness of the scratch-resistant layer and the base material protective layer is 10 μm or less.SELECTED DRAWING: None

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 Summary of the Invention [Problem to be solved by the invention]

[0007] Since the exterior material for an electricity storage device formed from the above-mentioned film-like laminate is softer and more susceptible to surface scratches than a metal exterior material, it is desirable to improve its scratch resistance. One method for improving the scratch resistance of the exterior material for an electricity storage device is to provide a hard layer containing inorganic particles such as silica particles as a scratch-resistant layer further outside the base material layer.

[0008] However, as described above, in electrical storage device packaging materials, recesses are generally formed by cold forming, and therefore, if a hard scratch-resistant layer containing inorganic particles such as silica particles is provided further outside the substrate layer, scratch resistance is improved but formability is reduced. In particular, there is a problem that the hard scratch-resistant layer is prone to cracking at the corners of the recesses formed by forming the electrical storage device packaging material. Therefore, it has been difficult to achieve both excellent scratch resistance and excellent formability in electrical storage device packaging materials using a method of providing a scratch-resistant layer containing inorganic particles such as silica particles.

[0009] Under these circumstances, a main object of the present disclosure is to provide an exterior material for an electricity storage device that exhibits excellent formability despite being endowed with excellent scratch resistance by a scratch-resistant layer. [Means for solving the problem]

[0010] The inventors of the present disclosure conducted extensive research to solve the above-mentioned problems, and as a result, they found that by providing a scratch-resistant layer containing inorganic particles and a resin on the surface of an electrical storage device exterior material, and further disposing a substrate protective layer between the scratch-resistant layer and the substrate layer, and setting the average film thickness of the scratch-resistant layer and the substrate protective layer together to 10 μm or less, the scratch-resistant layer imparts excellent scratch resistance, and also effectively suppresses cracking of the scratch-resistant layer due to molding of the electrical storage device exterior material.

[0011] 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. The laminate is composed of at least a scratch-resistant layer, a substrate protective layer, a substrate layer, a barrier layer, and a heat-sealable resin layer, in this order; the scratch-resistant layer contains inorganic particles and a resin, The exterior material for an electricity storage device, wherein the average film thickness of the scratch-resistant layer and the base material protective layer combined is 10 μm or less. [Effects of the Invention]

[0012] According to the present disclosure, it is possible to provide an exterior material for an electricity storage device that has excellent scratch resistance and formability. Furthermore, according to the present disclosure, it is also possible to provide a method for manufacturing the exterior material for an electricity storage device, and an electricity storage device that uses the exterior material for an electricity storage device. [Brief explanation of the drawings]

[0013] [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 diagram schematically showing a cross section in the thickness direction of a scratch-resistant layer and a substrate protective layer of an exterior packaging material for an electricity storage device according to the present disclosure, observed with a scanning electron microscope. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0014] The packaging material for an electricity storage device according to the present disclosure is composed of a laminate including at least a scratch-resistant layer, a substrate protective layer, a substrate layer, a barrier layer, and a heat-sealable resin layer, in this order, the scratch-resistant layer containing inorganic particles and a resin, and the average film thickness of the scratch-resistant layer and the substrate protective layer combined is 10 μm or less. By having this configuration, the packaging material for an electricity storage device according to the present disclosure can achieve both excellent scratch resistance and excellent formability.

[0015] 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.

[0016] 1.Layer structure of exterior materials for energy storage devices As shown in Figures 1 to 3, for example, an electrical storage device packaging material 10 according to the present disclosure is composed of a laminate including at least a scratch-resistant layer 7, a substrate protective layer 6, a substrate layer 1, a barrier layer 3, and a heat-sealable resin layer 4. In the electrical storage device packaging material 10, the scratch-resistant layer 7 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 facing each other.

[0017] 2 and 3, the packaging material 10 for an electricity storage device 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. Also, as shown in FIG. 3, for example, an adhesive layer 5 may have an adhesive layer 5 between the barrier layer 3 and the heat-sealable resin layer 4, if necessary, for the purpose of increasing the adhesion between these layers.

[0018] 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, with about 60 to 155 μm being particularly preferred. The thickness of the laminate constituting the packaging material 10 for an electricity storage device is the sum of the average film thickness of the scratch-resistant layer 7 and the substrate protective layer 6 combined and the total film thickness of the layers other than the scratch-resistant layer 7 and the substrate protective layer 6.

[0019] In the electrical storage device packaging material 10, the ratio of the total thickness of the scratch-resistant layer 7, substrate protective layer 6, substrate layer 1, adhesive layer 2 (optional), barrier layer 3, adhesive layer 5 (optional), and heat-sealable resin layer 4 to the thickness (total thickness) of the laminate constituting the electrical storage device packaging material 10 is preferably 90% or more, more preferably 95% or more, and even more preferably 98% or more. As a specific example, when the electrical storage device packaging material 10 of the present disclosure includes the scratch-resistant layer 7, substrate protective layer 6, substrate layer 1, adhesive layer 2, barrier layer 3, adhesive layer 5, and heat-sealable resin layer 4, the ratio of the total thickness of these layers to the thickness (total thickness) of the laminate constituting the electrical storage device packaging material 10 is preferably 90% or more, more preferably 95% or more, and even more preferably 98% or more. Furthermore, even when the packaging material 10 for an electricity storage device of the present disclosure includes a scratch-resistant layer 7, a substrate protective layer 6, a substrate layer 1, an adhesive layer 2, a barrier layer 3, and a heat-sealable resin layer 4, the ratio of the total thickness of these layers to the thickness (total thickness) of the laminate constituting the packaging material 10 for an electricity storage device is preferably 90% or more, more preferably 95% or more, and even more preferably 98% or more.

[0020] 2. Each layer that forms the exterior material for the energy storage device [Scratch resistant layer 7] The packaging material 10 for an electricity storage device according to the present disclosure has a scratch-resistant layer 7 on its outer surface for the purpose of improving scratch resistance, etc. The scratch-resistant layer 7 is a layer located as the outermost layer of the packaging material 10 for an electricity storage device when the packaging material 10 for an electricity storage device is used to assemble an electricity storage device.

[0021] The scratch-resistant layer 7 contains inorganic particles 71 and a resin. That is, the scratch-resistant layer 7 is formed of a resin composition containing the inorganic particles 71 and a resin. The average film thickness of the scratch-resistant layer 7 and the substrate protective layer 6 described below combined is set to 10 μm or less.

[0022] Examples of inorganic particles 71 include silica, talc, 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, gold, aluminum, copper, and nickel. Among these, silica particles are particularly preferred from the viewpoint of achieving both excellent scratch resistance and excellent formability. The inorganic particles 71 contained in the scratch-resistant layer 7 may be one type or two or more types.

[0023] The shape of the inorganic particles 71 is not particularly limited, and examples thereof include spherical, fibrous, plate-like, irregular, and scaly shapes, with spherical being preferred.

[0024] The inorganic particles 71 have an average particle size of, for example, about 0.5 nm to 5 μm, preferably about 0.5 to 3 μm, from the viewpoint of achieving both excellent scratch resistance and excellent moldability.

[0025] The average particle size of the inorganic particles 71 is the median size measured by a laser diffraction / scattering particle size distribution measuring device.

[0026] From the viewpoint of optimally achieving both excellent scratch resistance and excellent moldability, the content of inorganic particles 71 contained in scratch-resistant layer 7 is preferably about 0.1 part by mass or more, more preferably about 0.5 part by mass or more, and even more preferably about 1.0 part by mass or more, relative to 100 parts by mass of the resin. From the same viewpoint, the content of inorganic particles 71 contained in scratch-resistant layer 7 is preferably about 10.0 parts by mass or less, more preferably about 5.0 parts by mass or less, and even more preferably about 3.0 parts by mass or less. Preferred ranges for the content of inorganic particles 71 contained in scratch-resistant layer 7 include about 0.1 to 10.0 parts by mass, about 0.1 to 5.0 parts by mass, about 0.1 to 3.0 parts by mass, about 0.5 to 10.0 parts by mass, about 0.5 to 5.0 parts by mass, about 0.5 to 3.0 parts by mass, about 1.0 to 10.0 parts by mass, about 1.0 to 5.0 parts by mass, and about 1.0 to 3.0 parts by mass.

[0027] From the viewpoint of achieving both excellent scratch resistance and excellent formability, it is preferable that the scratch-resistant layer 7 further contains organic particles 72 in addition to the inorganic particles 71. Examples of the organic particles 72 include organic particles of nylon, polyacrylate, polystyrene, styrene-acrylic copolymer, polyethylene, benzoguanamine, or crosslinked products thereof. The organic particles 72 contained in the scratch-resistant layer 7 may be of one type or two or more types.

[0028] From the viewpoint of achieving both excellent scratch resistance and excellent moldability, the particle diameter of the organic particles 72 is preferably about 5.0 μm or less, more preferably about 3.0 μm or less, and even more preferably about 2.0 μm or less. From the same viewpoint, the particle diameter of the organic particles 72 is preferably about 0.3 μm or more, more preferably about 0.5 μm or more, and even more preferably about 1.0 μm or more. Preferred particle diameter ranges of the organic particles 72 include about 0.3 to 5.0 μm, about 0.3 to 3.0 μm, about 0.3 to 2.0 μm, about 0.5 to 5.0 μm, about 0.5 to 3.0 μm, about 0.5 to 2.0 μm, about 1.0 to 5.0 μm, about 1.0 to 3.0 μm, and about 1.0 to 2.0 μm. Note that the particle diameters indicated here mean that the organic particles 72 contained in the scratch-resistant layer 7 predominantly contain organic particles of these particle diameters. Of the organic particles 72 contained in the scratch-resistant layer 7, the proportion of organic particles with these particle diameters is preferably 50% or more, more preferably 80% or more, even more preferably 90% or more, and may be 100%.

[0029] The particle diameter of the organic particles 72 is a value measured on a cross-sectional image of the scratch-resistant layer 7 in the thickness direction observed using a scanning electron microscope. The particle diameter of the organic particles 72 means the diameter at which the linear distance connecting the leftmost end of the particle in the direction perpendicular to the thickness direction and the rightmost end of the particle in the direction perpendicular to the thickness direction is the longest, as observed using a scanning electron microscope. The particle diameter of the organic particles 72 is not the average particle diameter.

[0030] The shape of the organic particles 72 is not particularly limited, and examples thereof include spherical, fibrous, plate-like, irregular, and scaly shapes, with spherical being preferred.

[0031] To achieve both excellent scratch resistance and excellent moldability, the content of organic particles 72 in scratch-resistant layer 7 is preferably at least about 0.01 parts by weight, more preferably at least about 0.1 parts by weight, and even more preferably at least about 0.5 parts by weight, per 100 parts by weight of the resin. From the same perspective, the content is preferably no more than about 10.0 parts by weight, more preferably no more than about 5.0 parts by weight, and even more preferably no more than about 3.0 parts by weight. Preferred ranges for the content include about 0.01 to 10.0 parts by weight, about 0.01 to 5.0 parts by weight, about 0.01 to 3.0 parts by weight, about 0.1 to 10.0 parts by weight, about 0.1 to 5.0 parts by weight, about 0.1 to 3.0 parts by weight, about 0.5 to 10.0 parts by weight, about 0.5 to 5.0 parts by weight, and about 0.5 to 3.0 parts by weight.

[0032] The average thickness of the scratch-resistant layer 7 is not particularly limited, as long as the combined average thickness of the scratch-resistant layer 7 and the substrate protective layer 6 described below is 10 μm or less. However, from the viewpoint of optimally achieving both excellent scratch resistance and excellent formability, it is preferably about 2.5 μm or less, more preferably about 2.0 μm or less, and even more preferably about 1.5 μm or less. From the same viewpoint, the average thickness of the scratch-resistant layer 7 is preferably about 0.3 μm or more, more preferably about 0.5 μm or more. Preferred ranges for the average thickness of the scratch-resistant layer 7 include about 0.3 to 2.5 μm, about 0.3 to 2.0 μm, about 0.3 to 1.5 μm, about 0.5 to 2.5 μm, about 0.5 to 2.0 μm, and about 0.5 to 1.5 μm. The average thickness of the scratch-resistant layer 7 is measured as follows.

[0033] <Average film thickness> The average film thicknesses of the scratch-resistant layer 7 and the substrate protective layer 6 of the laminate constituting the electrical storage device packaging material are measured and calculated as follows. A cross-sectional image of a cross section in the thickness direction of the laminate constituting the electrical storage device packaging material is obtained using a scanning electron microscope (SEM). Next, for the cross-sectional image, the cross-sectional areas of the scratch-resistant layer 7 and the substrate protective layer 6 are each measured by image analysis. At this time, the horizontal length of the measurement area of ​​the cross-sectional area (the length in the direction perpendicular to the thickness direction of the laminate) is set to 25.4 μm. Next, the average film thickness (μm) of the scratch-resistant layer 7 and the substrate protective layer 6 is calculated by dividing the obtained area by the horizontal length (25.4 μm). When measuring and calculating the total average film thickness of the scratch-resistant layer 7 and the substrate protective layer 6, the cross-sectional areas of the scratch-resistant layer 7 and the substrate protective layer 6 in the same measurement area are measured simultaneously, and the obtained area is divided by the horizontal length of the measurement area (25.4 μm) to calculate the average film thickness (μm) of the scratch-resistant layer 7 and the substrate protective layer 6 combined.

[0034] The scratch-resistant layer 7 preferably contains particles having a particle size larger than the average film thickness of the scratch-resistant layer 7. That is, the scratch-resistant layer 7 preferably contains, as at least a portion of its inorganic particles, at least one of inorganic particles having a particle size larger than the average film thickness of the scratch-resistant layer 7 and organic particles having a particle size larger than the average film thickness of the scratch-resistant layer 7. The substrate protective layer 6 described below preferably contains particles having a particle size larger than the average film thickness of the substrate protective layer 6. That is, the substrate protective layer 6 preferably contains at least one of inorganic particles having a particle size larger than the average film thickness of the substrate protective layer 6 and organic particles having a particle size larger than the average film thickness of the substrate protective layer 6. For each of the scratch-resistant layer 7 and the substrate protective layer 6, particles having a particle size larger than the average film thickness of each layer will be referred to as "large particles" hereinafter. It is more preferable that both the scratch-resistant layer 7 and the substrate protective layer 6 contain large particles. The large particles are preferably either inorganic particles 61, 71 or organic particles 62, 72, and preferably organic particles 72. That is, when organic particles 62, 72 are contained in at least one of the scratch-resistant layer 7 and the substrate protective layer 6, it is preferable that at least one of the scratch-resistant layer 7 and the substrate protective layer 6 contains organic particles 62, 72 with a particle diameter larger than the average film thickness of the layer. It is preferable that each layer (scratch-resistant layer 7 and substrate protective layer 6) contains, for example, about 30 or more large particles within a 1 mm wide area of ​​each layer. The number of large particles within a 1 mm wide area of ​​each layer is preferably about 50 or more, more preferably about 70 or more. Furthermore, the number of large particles within a 1 mm wide area of ​​each layer is preferably about 500 or less, more preferably about 400 or less, and even more preferably about 200 or less. Furthermore, preferred ranges for the number of large particles within a 1 mm wide range of each layer include about 30 to 500, about 30 to 400, about 30 to 200, about 50 to 500, about 50 to 400, about 50 to 200, about 70 to 500, about 70 to 400, and about 70 to 200. The number of large particles can be obtained by observing a cross-sectional image (1 mm wide) of each layer in the thickness direction using a scanning electron microscope.

[0035] The particle size of the large particles is preferably about 1.0 to 5.0 μm.

[0036] When the hardness of the large particles and the resin in a cross section in the thickness direction of the scratch-resistant layer 7 is measured by nanoindentation in an environment of 23°C, the hardness of the large particles is preferably greater than the hardness of the resin. In the present disclosure, the method for measuring hardness by nanoindentation is as follows.

[0037] <Hardness measured by nanoindentation at 23°C> The hardness is measured using a nanoindenter (e.g., HYSITRON's "TI950 TriboIndenter") as the device. A Berkovich indenter (e.g., TI-0039) is used as the indenter of the nanoindenter. First, in an environment of 50% relative humidity and 23°C, the indenter is placed on the surface to be measured of the electrical storage device packaging material (the surface on which the scratch-resistant layer or base protective layer is exposed, parallel to the thickness direction of each layer) from a direction perpendicular to the thickness direction, and the indenter is pressed into the surface up to a load of 50 μN over 10 seconds, held in that state for 5 seconds, and then unloaded over 10 seconds. The hardness is the average value of N=5 measurements taken at different measurement points. The surface to which the indenter is pressed is the exposed cross section of the scratch-resistant layer or base protective layer to be measured, obtained by cutting the electrical storage device packaging material in the thickness direction through the center. Furthermore, when measuring the hardness of the resin of the scratch-resistant layer or the substrate protective layer, the indenter is pressed into the portion (resin portion) where no particles are present on the surface. When measuring the hardness of the particles of the scratch-resistant layer or the substrate protective layer, the indenter is pressed into the portion where particles are present on the surface. Cutting is performed using a commercially available rotary microtome.

[0038] The hardness of the large particles measured by nanoindentation is preferably about 400 MPa or more, more preferably about 430 MPa or more. The hardness is preferably about 600 MPa or less. Preferred ranges for the hardness include about 400 to 600 MPa and about 430 to 600 MPa. Large particles having these hardnesses are preferably large organic particles.

[0039] In the scratch-resistant layer 7, the difference between the hardness of the large particles and the hardness of the resin is preferably about 100 MPa or more, more preferably about 130 MPa or more. The hardness is preferably about 300 MPa or less. Preferred ranges for the hardness include about 100 to 300 MPa, and about 130 to 300 MPa. Large particles having these hardnesses are preferably large organic particles.

[0040] The resin contained in the scratch-resistant layer 7 is preferably a curable resin. That is, the scratch-resistant layer 7 is preferably made of a cured product of a resin composition containing a curable resin and inorganic particles 71.

[0041] The curable resin may be either a one-component curing type or a two-component curing type, but is preferably a two-component curing type. Examples of two-component curing resins include two-component curing polyurethane, two-component curing polyester, and two-component curing epoxy resin. Among these, two-component curing polyurethane is preferred.

[0042] 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 of two-component curing polyurethanes include those using a polyol such as polyester polyol, polyether polyol, or acrylic polyol as a base component and an aromatic or aliphatic polyisocyanate as a 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, polymers (e.g., trimers) can also be used as polyisocyanate compounds. Examples of such polymers include adducts, biurets, and nurates. The term "aliphatic isocyanate compound" refers to an isocyanate having an aliphatic group but no aromatic ring, the term "alicyclic isocyanate compound" refers to an isocyanate having an alicyclic hydrocarbon group, and the term "aromatic isocyanate compound" refers to an isocyanate having an aromatic ring.

[0043] It is preferable that the scratch-resistant layer 7 and the substrate protective layer 6 contain different resins. More specifically, it is preferable that the scratch-resistant layer 7 and the substrate protective layer 6 contain different resins, and that these layers have different hardnesses measured by nanoindentation, and it is preferable that the hardness of the resin in the scratch-resistant layer 7 is greater than the hardness of the resin in the substrate protective layer 6.

[0044] The hardness of the resin of the scratch-resistant layer 7, measured by nanoindentation, is preferably about 150 MPa or more, more preferably about 170 MPa or more. The hardness is preferably about 400 MPa or less, more preferably about 300 MPa or less. Examples of preferred hardness ranges include about 150 to 400 MPa, about 150 to 300 MPa, about 170 to 400 MPa, and about 170 to 300 MPa.

[0045] The difference in hardness between the resin of the scratch-resistant layer 7 and the resin of the substrate protective layer 6 is preferably about 100 MPa or more, more preferably about 150 MPa or more. Furthermore, this difference is preferably about 300 MPa or less, more preferably 250 MPa or less. Preferred ranges for this hardness difference include about 100 to 300 MPa, about 100 to 250 MPa, about 150 to 300 MPa, and about 150 to 250 MPa. As mentioned above, the hardness of the resin of the scratch-resistant layer 7 is preferably greater than the hardness of the resin of the substrate protective layer 6.

[0046] In the resin composition forming the scratch-resistant layer 7, when the resin is polyurethane containing a base agent containing a polyol compound and a curing agent containing an isocyanate compound, for example, the hardness of the resin measured by the nanoindentation method can be adjusted by adjusting the ratio of the base agent to the curing agent.

[0047] At least one of the surface and interior of the scratch-resistant layer 7 may further contain additives (additives) such as lubricants, colorants, antiblocking agents, flame retardants, antioxidants, tackifiers, and antistatic agents, as described below, depending on the functionality that the scratch-resistant layer 7 and its surface are to have.

[0048] When the scratch-resistant layer 7 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 scratch-resistant layer 7 include those exemplified in the section [Adhesive layer 2]. The preferred content of the colorant contained in the scratch-resistant layer 7 is also the same as that described in the section [Adhesive layer 2].

[0049] The method for forming the scratch-resistant layer 7 is not particularly limited, and examples thereof include a method of applying a resin composition for forming the scratch-resistant layer 7. When an additive is blended into the scratch-resistant layer 7, a resin mixed with the additive may be applied.

[0050] 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 scratch-resistant layer 7. 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.

[0051] When a lubricant is present on the surface of the scratch-resistant layer 7, 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

[0052] The lubricant present on the surface of the scratch-resistant layer 7 may be a lubricant exuded from the scratch-resistant layer 7, or a lubricant applied to the surface of the scratch-resistant layer 7.

[0053] [Base material protective layer 6] The packaging material 10 for an electricity storage device according to the present disclosure has a substrate protective layer 6 between the scratch-resistant layer 7 and the substrate layer 1, for the purpose of improving the formability of the packaging material 10 for an electricity storage device including the scratch-resistant layer 7. The substrate protective layer 6 is preferably in contact with the scratch-resistant layer 7 and the substrate layer 1.

[0054] Furthermore, in the packaging material 10 for an electricity storage device according to the present disclosure, the average combined film thickness of the scratch-resistant layer 7 and the substrate protective layer 6 is set to 10 μm or less, as described above.

[0055] The substrate protective layer 6 contains a resin, and preferably further contains inorganic particles 61. That is, the substrate protective layer 6 is preferably formed from a resin composition containing a resin and inorganic particles 61.

[0056] Examples of the inorganic particles 61 include the same ones as those exemplified for the scratch-resistant layer 7. Among these, from the viewpoint of achieving both excellent scratch resistance and excellent formability, barium sulfate is particularly preferred as the inorganic particles 61 contained in the substrate protective layer 6. The inorganic particles 61 contained in the substrate protective layer 6 may be of one type or two or more types.

[0057] In the substrate protective layer 6, the shape of the inorganic particles 61 is not particularly limited, and examples thereof include spherical, fibrous, plate-like, irregular, and scaly shapes, with spherical shapes being preferred.

[0058] In the substrate protective layer 6, the average particle size of the inorganic particles 61 is, for example, about 0.5 nm to 5 μm, preferably about 0.5 to 3 μm, from the viewpoint of achieving both excellent scratch resistance and excellent moldability.

[0059] The average particle size of the inorganic particles 61 is the median size measured by a laser diffraction / scattering particle size distribution measuring device.

[0060] From the viewpoint of achieving both excellent scratch resistance and excellent moldability, the content of the inorganic particles 61 contained in the substrate protective layer 6 is preferably about 0.1 part by mass or more, more preferably about 0.5 part by mass or more, and even more preferably about 1.0 part by mass or more, relative to 100 parts by mass of the resin of the substrate protective layer 6. From the same viewpoint, the number of large particles within a 1 mm wide range of each layer is preferably about 10.0 parts by mass or less, more preferably about 5.0 parts by mass or less, and even more preferably about 3.0 parts by mass or less, relative to 100 parts by mass of the resin. Furthermore, preferred ranges for the number of large particles within a 1 mm width of each layer include, relative to 100 parts by mass of the resin, approximately 0.1 to 10.0 parts by mass, approximately 0.1 to 5.0 parts by mass, approximately 0.1 to 3.0 parts by mass, approximately 0.5 to 10.0 parts by mass, approximately 0.5 to 5.0 parts by mass, approximately 0.5 to 3.0 parts by mass, approximately 1.0 to 10.0 parts by mass, approximately 1.0 to 5.0 parts by mass, and approximately 1.0 to 3.0 parts by mass.

[0061] From the viewpoint of achieving both excellent scratch resistance and excellent formability, it is preferable that the substrate protective layer 6 further contains organic particles 62 in addition to the inorganic particles 61. Examples of the organic particles 62 include the same particles as those exemplified in the section on [Scratch-resistant layer 7]. The organic particles 62 contained in the substrate protective layer 6 may be of one type, or two or more types.

[0062] In the substrate protective layer 6, the particle size of the organic particles 62 is preferably about 5.0 μm or less, more preferably about 3.0 μm or less, and even more preferably about 2.0 μm or less, from the viewpoint of optimally achieving both excellent scratch resistance and excellent formability. From the same viewpoint, the particle size of the organic particles 62 is preferably about 0.3 μm or more, more preferably about 0.5 μm or more. Preferred particle size ranges for the organic particles 62 include about 0.3 to 5.0 μm, about 0.3 to 3.0 μm, about 0.3 to 2.0 μm, about 0.5 to 5.0 μm, about 0.5 to 3.0 μm, and about 0.5 to 2.0 μm. The particle size designations mean that the organic particles 62 contained in the substrate protective layer 6 predominantly comprise organic particles of these particle sizes. Of the organic particles 62 contained in the substrate protective layer 6, the proportion of organic particles with these particle diameters is preferably 50% or more, more preferably 80% or more, even more preferably 90% or more, and may be 100%.

[0063] The particle diameter of the organic particles 62 is a value measured on a cross-sectional image of the substrate protective layer 6 in the thickness direction observed using a scanning electron microscope. The particle diameter of the organic particles 62 means the diameter at which the linear distance connecting the leftmost end of the particle in the direction perpendicular to the thickness direction and the rightmost end of the particle in the direction perpendicular to the thickness direction is the longest, as observed using a scanning electron microscope. The particle diameter of the organic particles 62 is not an average particle diameter.

[0064] The shape of the organic particles 62 is not particularly limited, and examples thereof include spherical, fibrous, plate-like, irregular, and scaly shapes, with spherical being preferred.

[0065] To achieve both excellent scratch resistance and excellent moldability, when the substrate protective layer 6 contains organic particles 62, the content thereof is preferably at least about 0.01 part by weight, more preferably at least about 0.1 part by weight, and even more preferably at least about 0.5 part by weight, per 100 parts by weight of the resin. From the same viewpoint, the content is preferably no more than about 10.0 parts by weight, more preferably no more than about 5.0 parts by weight, and even more preferably no more than about 3.0 parts by weight. Preferred ranges for the content include about 0.01 to 10.0 parts by weight, about 0.01 to 5.0 parts by weight, about 0.01 to 3.0 parts by weight, about 0.1 to 10.0 parts by weight, about 0.1 to 5.0 parts by weight, about 0.1 to 3.0 parts by weight, about 0.5 to 10.0 parts by weight, about 0.5 to 5.0 parts by weight, and about 0.5 to 3.0 parts by weight.

[0066] The average thickness of the substrate protective layer 6 is not particularly limited, as long as the combined average thickness of the scratch-resistant layer 7 and the substrate protective layer 6 is 10 μm or less. From the viewpoint of achieving both excellent scratch resistance and excellent formability, the average thickness of the substrate protective layer 6 is preferably about 2.0 μm or less, more preferably about 1.5 μm or less. From the same viewpoint, the average thickness of the substrate protective layer 6 is preferably about 0.1 μm or more, more preferably about 0.3 μm or more. Preferred ranges for the average thickness of the substrate protective layer 6 include about 0.1 to 2.0 μm, about 0.1 to 1.5 μm, about 0.3 to 2.0 μm, and about 0.3 to 1.5 μm. The method for measuring the average thickness of the substrate protective layer 6 is as described above.

[0067] As described above, at least one of the scratch-resistant layer 7 and the substrate protective layer 6 preferably contains particles having a particle diameter larger than the average film thickness of the layer, and it is more preferable that both the scratch-resistant layer 7 and the substrate protective layer 6 contain such large particles. The large particles are preferably either the inorganic particles 61, 71 or the organic particles 62, 72, and are preferably organic particles 62. In other words, when at least one of the scratch-resistant layer 7 and the substrate protective layer 6 contains organic particles 62, 72, it is preferable that at least one of the scratch-resistant layer 7 and the substrate protective layer 6 contains organic particles 62, 72 having a particle diameter larger than the average film thickness of the layer.

[0068] As mentioned above, the particle size of the large particles is preferably about 1.0 to 5.0 μm.

[0069] When the hardness of the large particles and the resin in a cross section in the thickness direction of the substrate protective layer 6 is measured by nanoindentation in a 23°C environment, it is preferable that the hardness of the large particles is greater than the hardness of the resin of the substrate protective layer 6. In the present disclosure, the method for measuring hardness by nanoindentation is as described above.

[0070] The hardness of the large particles in the substrate protective layer 6, as measured by nanoindentation, is preferably about 400 MPa or more, more preferably about 430 MPa or more. The hardness is preferably about 600 MPa or less. Preferred ranges for the hardness include about 400 to 600 MPa, and about 430 to 600 MPa. Large particles having these hardnesses are preferably large organic particles.

[0071] The resin contained in the substrate protective layer 6 is preferably a curable resin. That is, the substrate protective layer 6 is more preferably made of a cured product of a resin composition containing a curable resin.

[0072] In the substrate protective layer 6, the curable resin may be either a one-component curing type or a two-component curing type, but is preferably a two-component curing type. Examples of two-component curing resins include two-component curing polyurethane, two-component curing polyester, and two-component curing epoxy resin. Among these, two-component curing polyurethane is preferred.

[0073] Examples of the two-component curing polyurethane include the same as those exemplified in the section [Scratch-resistant layer 7] above.

[0074] The hardness of the resin of the substrate protective layer 6, as measured by nanoindentation, is preferably about 150 MPa or less, more preferably about 100 MPa or less, and even more preferably about 50 MPa or less. The hardness is preferably about 5 MPa or more, and more preferably about 10 MPa or more. Preferred ranges for the hardness include about 5 to 150 MPa, about 5 to 100 MPa, about 5 to 50 MPa, about 10 to 150 MPa, about 10 to 100 MPa, and about 10 to 50 MPa.

[0075] In the resin composition forming the substrate protective layer 6, when the resin is polyurethane containing a main agent containing a polyol compound and a curing agent containing an isocyanate compound, for example, the hardness of the resin measured by the nanoindentation method can be adjusted by adjusting the ratio of the main agent to the curing agent.

[0076] The substrate protective layer 6 may further contain additives such as colorants, antiblocking agents, flame retardants, antioxidants, tackifiers, and antistatic agents, as described below, depending on the functionality that the substrate protective layer 6 is to have.

[0077] When the substrate protective 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 substrate protective layer 6 include those exemplified in the section [Adhesive layer 2]. The preferred content of the colorant contained in the substrate protective layer 6 is also the same as that described in the section [Adhesive layer 2].

[0078] The method for forming the substrate protective layer 6 is not particularly limited, and examples thereof include a method of applying a resin composition for forming the substrate protective layer 6. When an additive is blended into the substrate protective layer 6, a resin mixed with the additive may be applied.

[0079] [Base material layer 1] In the present disclosure, the substrate layer 1 is a layer provided for the purpose of, for example, exhibiting the function as a substrate of the packaging material for an electricity storage device. The substrate layer 1 is located between the substrate protective layer 6 and the barrier layer 3 of the packaging material 10 for an electricity storage device.

[0080] There are no particular limitations on the material forming the base layer 1, as long as it functions as a base, i.e., has at least insulating properties. The base layer 1 can be formed using, for example, a resin, which may contain additives described below.

[0081] 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.

[0082] 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.

[0083] Of these, preferred resins for forming the base layer 1 include polyester and polyamide.

[0084] 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.

[0085] 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. These polyamides may be used singly or in combination of two or more.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] Furthermore, additives such as 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.

[0091] 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.

[0092] [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.

[0093] 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.

[0094] 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.

[0095] Examples of polyurethane adhesives include polyurethane adhesives containing a base agent containing a polyol compound and a curing agent containing an isocyanate compound. Preferred examples include two-component curing polyurethane adhesives that use 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, as the polyol compound, it is preferable to use a polyester polyol that has hydroxyl groups on the side chain in addition to the terminal hydroxyl groups of the repeating unit. Forming the adhesive layer 2 from a polyurethane adhesive provides the electrical storage device exterior material with excellent electrolyte resistance, preventing peeling of the base layer 1 even when the electrolyte adheres to the side surface.

[0096] 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.

[0097] The type of pigment is not particularly limited as long as it 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 oxide-based, cadmium-based, lead-based, chromium oxide-based, and iron-based pigments, and other examples include finely powdered mica and fish scale foil.

[0098] Among colorants, carbon black is preferred in order to give the exterior appearance of the electrical storage device packaging material a black color, for example.

[0099] The average particle size of the pigment is not particularly limited and may be, for example, about 0.05 to 5 μm, and preferably about 0.08 to 2 μm. The average particle size of the pigment is the median size measured with a laser diffraction / scattering particle size distribution measuring device.

[0100] The content of the pigment in the adhesive layer 2 is not particularly limited as long as it colors the packaging material for an electricity storage device, and may be, for example, about 5 to 60 mass %, and preferably 10 to 40 mass %.

[0101] 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.

[0102] [Colored layer] The colored layer is a layer (not shown) that is provided between the base material layer 1 and the barrier layer 3 as needed. When the adhesive layer 2 is provided, a colored layer may be provided between the base material layer 1 and the adhesive layer 2, or between the adhesive layer 2 and the barrier layer 3. Alternatively, a colored layer may be provided on the outside of the base material layer 1. By providing a colored layer, the packaging material for an electricity storage device can be colored.

[0103] The colored layer 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.

[0104] Specific examples of the colorant contained in the colored layer include the same as those exemplified in the section [Adhesive layer 2].

[0105] [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.

[0106] 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.

[0107] 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.

[0108] 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.

[0109] 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.

[0110] 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.

[0111] 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.

[0112] 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.

[0113] 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.

[0114] [ka]

[0115] [ka]

[0116] [ka]

[0117] [ka]

[0118] 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 ) into the polymer obtained above. The aminated phenol polymers may be used singly or in combination of two or more.

[0119] 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.

[0120] 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.

[0121] 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.

[0122] The composition of the corrosion-resistant film can be analyzed using, for example, time-of-flight secondary ion mass spectrometry.

[0123] 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 For example, the amount of the chromate compound is about 0.5 to 50 mg, preferably 1 mg, in terms of chromium. It is desirable that the content be about 0.0 to 40 mg, the phosphorus compound be about 0.5 to 50 mg, preferably about 1.0 to 40 mg, and the aminated phenol polymer be about 1.0 to 200 mg, preferably about 5.0 to 150 mg, in terms of phosphorus.

[0124] 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 and 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 corrosion-resistant 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.

[0125] 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.

[0126] [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 exhibits the function of sealing the electricity storage device elements by heat-sealing the heat-sealable resin layers to each other when assembling the electricity storage device.

[0127] 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.

[0128] 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.

[0129] 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.

[0130] 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.

[0131] 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.

[0132] 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.

[0133] 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.

[0134] 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.

[0135] The lubricant is not particularly limited, but preferably an amide-based lubricant is used. Specific examples of the lubricant include those exemplified for the scratch-resistant layer 7. The lubricant may be used alone or in combination of two or more.

[0136] When a lubricant is present on the surface of the heat-sealable resin layer 4, the amount of the lubricant is not particularly limited. However, from the viewpoint of improving the formability of the packaging material for an electricity storage device, the amount of the lubricant is preferably 10 to 50 mg / m 2 approximately, more preferably 15 to 40 mg / m 2 The degree of

[0137] 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.

[0138] The thickness of the heat-sealable resin layer 4 is not particularly limited as long as it functions to heat-seal the heat-sealable resin layers together and 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.

[0139] [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 provided as needed between the barrier layer 3 (or acid-resistant film) and the heat-sealable resin layer 4 in order to firmly bond them together.

[0140] The adhesive layer 5 is formed of a resin capable of bonding the barrier layer 3 and the heat-sealable resin layer 4. Examples of resins that can be used to form the adhesive layer 5 include the same adhesives as those exemplified for the adhesive layer 2. From the viewpoint of firmly bonding the adhesive layer 5 and the heat-sealable resin layer 4, 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. From the viewpoint of firmly bonding the barrier layer 3 and the adhesive layer 5, the adhesive layer 5 preferably contains an acid-modified polyolefin. Examples of acid-modified components include dicarboxylic acids such as maleic acid, itaconic acid, succinic acid, and adipic acid, as well as anhydrides thereof, acrylic acid, and methacrylic acid. However, from the viewpoints of ease of modification and versatility, maleic anhydride is most preferred. From the viewpoint of the heat resistance of the electrical storage device exterior material, the olefin component is preferably a polypropylene-based resin, and the adhesive layer 5 most preferably contains maleic anhydride-modified polypropylene.

[0141] The presence of a polyolefin skeleton in the resin constituting the adhesive layer 5 can be determined by, for example, infrared spectroscopy, gas chromatography mass spectrometry, or the like, and the analysis method is not particularly limited. Furthermore, the presence of an acid-modified polyolefin in the resin constituting the adhesive layer 5 can be determined by, for example, measuring a maleic anhydride-modified polyolefin by infrared spectroscopy, and finding a peak at a wave number 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.

[0142] Furthermore, from the viewpoint of ensuring durability such as heat resistance and resistance to contents of the packaging material for an electricity storage device, and of ensuring moldability while reducing the thickness, 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.

[0143] 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, and more preferably contains polyurethane and epoxy resin. Examples of polyesters include ester resins formed by the reaction of epoxy groups with maleic anhydride groups, and amide ester resins formed by the reaction of oxazoline groups with maleic anhydride groups. If unreacted components of a curing agent such as a compound having an isocyanate group, a compound having an oxazoline group, or an epoxy resin remain in the adhesive layer 5, the presence of the unreacted components can be confirmed by a method selected from the group consisting of infrared spectroscopy, Raman spectroscopy, time-of-flight secondary ion mass spectrometry (TOF-SIMS), and the like.

[0144] 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 and curing agents having an epoxy group. 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.

[0145] 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 preferable. The polyfunctional isocyanate compound is not particularly limited as long as it has 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), and polymerized versions of these. Examples of polymers include dimeric uretdione, trimer nurate, biuret, and adducts obtained by addition to polyhydric alcohols (e.g., trimethylolpropane). Furthermore, MDI may be a polymer (polymeric MDI) produced as an oligomer.

[0146] 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.

[0147] 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.

[0148] 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.

[0149] 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 first 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.

[0150] Specific examples of epoxy resins include glycidyl ether derivatives of trimethylolpropane, bisphenol A diglycidyl ether, modified bisphenol A diglycidyl ether, bisphenol F glycidyl 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.

[0151] 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.

[0152] 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.

[0153] 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.

[0154] 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.

[0155] The adhesive layer 5 may contain a modifier having a carbodiimide group.

[0156] 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.

[0157] 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 producing a laminate in which, from the outside, at least a scratch-resistant layer 7, a substrate protective layer 6, a substrate layer 1, a barrier layer 3, and a heat-sealable resin layer 4 are laminated. Specifically, the method for producing an electrical storage device exterior material of the present disclosure comprises a step of producing a laminate in which at least a scratch-resistant layer, a substrate protective layer, a substrate layer, a barrier layer, and a heat-sealable resin layer are laminated in this order, the scratch-resistant layer containing inorganic particles and a resin, and the average film thickness of the scratch-resistant layer and the substrate protective layer combined is 10 μm or less.

[0158] 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.

[0159] 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.

[0160] Next, a substrate protective layer 6 and a scratch-resistant layer 7 are sequentially laminated on the surface of the substrate layer 1 opposite to the barrier layer 3. The substrate protective layer 6 and the scratch-resistant layer 7 can be formed, for example, by applying the above-described resin compositions for forming the substrate protective layer 6 and the scratch-resistant layer 7 to the surface of the substrate layer 1 and curing them. The order of the step of laminating the barrier layer 3 on the surface of the substrate layer 1 and the step of laminating the substrate protective layer 6 and the scratch-resistant layer 7 on the surface of the substrate layer 1 is not particularly limited. For example, after the substrate protective layer 6 and the scratch-resistant layer 7 are formed on the surface of the substrate layer 1, the barrier layer 3 may be formed on the surface of the substrate layer 1 opposite to the substrate protective layer 6 side.

[0161] As described above, a laminate is formed which includes, from the outside in order, the scratch-resistant layer 7, the substrate protective layer 6, the substrate layer 1, the optional adhesive layer 2, the barrier layer 3, the optional adhesive layer 5, and the heat-sealable resin layer 4. In order to strengthen the adhesion of the optional adhesive layer 2 and the adhesive layer 5, the laminate may be further subjected to a heat treatment. Furthermore, as described above, a colored layer may be provided between the substrate layer 1 and the barrier layer 3.

[0162] 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.

[0163] 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 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 the heat-sealable resin layers of the flange portion are heat-sealed 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 that contacts the electricity storage device element).

[0164] 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]

[0165] 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.

[0166] <Manufacturing of exterior materials for energy storage devices> Example 1 A stretched 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 a two-component urethane adhesive (a mixture of a polyol compound and an aromatic isocyanate compound), 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 using a treatment solution consisting of a phenolic resin, a chromium fluoride compound, and phosphoric acid, with a chromium coating amount of 10 mg / m. 2 (dry mass) by roll coating. The coating was applied to both sides of the foil and baked.

[0167] Next, maleic anhydride-modified polypropylene as an adhesive layer (thickness 20 μm) and random polypropylene as a heat-sealable resin layer (thickness 20 μm) were co-extruded onto the barrier layer of each of the laminates obtained above, thereby laminating an adhesive layer / heat-sealable resin layer onto the barrier layer.

[0168] Next, a resin composition containing barium sulfate (average particle diameter approximately 1 μm), resin (polyurethane formed from a mixture of one type of polyol compound and an aliphatic isocyanate compound), and polystyrene-based organic particles (particle diameter approximately 2 μm) was applied to the surface of the substrate layer of the obtained laminate using a gravure printing method to form a substrate protective layer (average film thickness 0.77 μm). Furthermore, a resin composition containing silica particles (average particle diameter approximately 1.5 μm), resin (polyurethane formed from a mixture of two types of polyol compounds and an aliphatic isocyanate compound), and polystyrene-based organic particles (particle diameter approximately 2 μm) was applied to the surface of the substrate protective layer using a gravure printing method to form a scratch-resistant layer (average film thickness 0.99 μm).This resulted in a laminate having, from the outside, the scratch-resistant layer (average film thickness 0.99 μm) / substrate protective layer (average film thickness 0.77 μm) / substrate layer (15 μm) / adhesive layer (3 μm) / barrier layer (35 μm) / adhesive layer (20 μm) / thermally adhesive resin layer (20 μm).

[0169] Example 2 A laminate was obtained in the same manner as in Example 1, except that the average thickness of the substrate protective layer was 0.53 μm and the average thickness of the scratch-resistant layer was 1.34 μm, in order from the outside in: scratch-resistant layer (average thickness 1.34 μm) / substrate protective layer (average thickness 0.53 μm) / substrate layer (15 μm) / adhesive layer (3 μm) / barrier layer (35 μm) / adhesive layer (20 μm) / thermally adhesive resin layer (20 μm).

[0170] Comparative Example 1 A laminate was obtained in the same manner as in Example 1, except that no substrate protective layer was provided and the resin composition forming the scratch-resistant layer was applied twice by gravure printing to set the average film thickness of the scratch-resistant layer to 2.53 μm, with the layers stacked from outside to inside in the order of scratch-resistant layer (average film thickness 2.53 μm), substrate layer (15 μm), adhesive layer (3 μm), barrier layer (35 μm), adhesive layer (20 μm), and heat-sealable resin layer (20 μm).

[0171] Comparative Example 2 A laminate was obtained in the same manner as in Example 1, except that no scratch-resistant layer was provided and the resin composition forming the substrate protective layer was applied twice by gravure printing to set the average film thickness of the substrate protective layer to 1.54 μm, with the layers stacked from outside to inside in the order of substrate protective layer (average film thickness 1.54 μm), substrate layer (15 μm), adhesive layer (3 μm), barrier layer (35 μm), adhesive layer (20 μm), and heat-sealable resin layer (20 μm).

[0172] <Average film thickness> The average film thicknesses of the scratch-resistant layer and the substrate protective layer of the laminate constituting the electrical storage device packaging material were measured and calculated as follows. A cross-sectional image of a cross section in the thickness direction of the laminate constituting the electrical storage device packaging material was obtained using a scanning electron microscope (SEM) under the conditions shown below. Next, for the cross-sectional image, the cross-sectional areas of the scratch-resistant layer and the substrate protective layer were each measured by image analysis. At this time, the horizontal length of the measurement area of ​​the cross-sectional area (the length perpendicular to the thickness direction of the laminate) was set to 25.4 μm. The average film thicknesses (μm) of the scratch-resistant layer and the substrate protective layer were then calculated by dividing the obtained area by the horizontal length (25.4 μm). When measuring and calculating the total average film thickness of the scratch-resistant layer and the substrate protective layer, the cross-sectional areas of the scratch-resistant layer and the substrate protective layer in the same measurement area were simultaneously measured, and the obtained area was divided by the horizontal length (25.4 μm) of the measurement area to calculate the average film thickness (μm) of the scratch-resistant layer and the substrate protective layer combined. (conditions) Equipment: Hitachi High-Technologies S-4800 Accelerating voltage: 30 kV Emission current: 10μA Detector: Transmission electron detector Inclination: None Magnification: 5000x Cross section processing method: The sample was cut into strips and embedded in resin. After the resin hardened, a rough cross section was prepared and the surface was polished. After that, the sample was stained with ruthenic acid for 2-3 hours and ultrathin sections (thickness: approximately 100 nm) were prepared using a microtome. A diamond knife was used.

[0173] When particles with a particle diameter larger than the average film thickness of the scratch-resistant layer were observed in the cross-sectional image of the exterior material for an electricity storage device (measurement area length 25.4 μm), one particle with a diameter of 1.11 μm was observed in the scratch-resistant layer of Example 1, and one particle with a diameter of 1.47 μm was observed in the scratch-resistant layer of Example 2. Furthermore, no particles with a particle diameter larger than the average film thickness of the scratch-resistant layer were observed in the scratch-resistant layer of Comparative Example 1, but relatively large particles with diameters of 1.97 μm, 1.51 μm, 1.86 μm, etc. were observed.

[0174] Furthermore, a cross-sectional image of the scratch-resistant layer of the exterior material for an electricity storage device in Example 1 was obtained using a scanning electron microscope (SEM) under the conditions shown below, and the number of particles that appeared to have a particle diameter approximately equal to or greater than the average film thickness was counted. It was found that there were approximately 60 such particles within a width of approximately 500 to 600 μm. (SEM conditions) Equipment: Hitachi High-Technologies S-4800 Accelerating voltage: 5 kV Emission current: 20μA Detector: Secondary electron detector Inclination: None Magnification: 5000x Number of observations: 23 Cross-section processing method: The sample was cut into strips and attached to a plastic plate with adhesive. After the adhesive had dried, the cross-section was prepared using a microtome. A diamond knife was used. For observation, the sample was scanned about five times to damage it (damage caused by the electron beam), and then images were taken.

[0175] <Hardness measured by nanoindentation at 23°C> The equipment used was a nanoindenter (HYSITRON's TI9 The hardness was measured using a nanoindenter ("50 TriboIndenter"). A Berkovich indenter (TI-0039) was used as the indenter for the nanoindenter. First, in an environment of 50% relative humidity and 23°C, the indenter was applied perpendicular to the thickness direction to the surface of the electrical storage device exterior material to be measured (the surface on which the scratch-resistant layer or base protective layer was exposed, parallel to the thickness direction of each layer). The indenter was pressed into the surface over 10 seconds up to a load of 50 μN, held in that state for 5 seconds, and then unloaded over 10 seconds. The average value of N=5 measurements at different measurement points was taken as the hardness. The results are shown in Table 1. The surface into which the indenter was pressed was the exposed cross section of the scratch-resistant layer or base protective layer to be measured, obtained by cutting the electrical storage device exterior material in the thickness direction through the center. In measuring the hardness of the scratch-resistant layer or base protective layer, the indenter was pressed into the portion (resin portion) on the surface where no particles were present. When measuring the hardness of particles in the scratch-resistant layer or base material protective layer, the hardness is measured at the portion where particles are present on the surface. Cutting was carried out using a commercially available rotary microtome.

[0176] Examples 1 and 2 and Comparative Example 1 share the same resin in the scratch-resistant layer, and the hardness of the resin in the scratch-resistant layer of the packaging materials for an electricity storage device of Examples 1 and 2 and Comparative Example 1 was all 218 MPa.

[0177] Examples 1 and 2 and Comparative Example 2 had the same resin contained in the substrate protective layer, and the hardness of the resin in the substrate protective layer of the packaging materials for an electricity storage device of Examples 1 and 2 and Comparative Example 2 was all 23 MPa.

[0178] Examples 1 and 2 and Comparative Examples 1 and 2 have the same organic particles contained in the scratch-resistant layer or substrate protective layer, and the hardness of the organic particles in the exterior materials for electricity storage devices of Examples 1 and 2 and Comparative Examples 1 and 2 was 496 MPa.

[0179] <Scratch resistance evaluation> The abrasion resistance evaluation device used was a Gakushin-type abrasion fastness tester AB-301 (manufactured by Tester Sangyo). The exterior material for an electric storage device was attached to the table of the abrasion tester, and a dry paper cloth (Kimwipe, manufactured by Nippon Paper Crecia) was attached to the tip of the arm (friction element) at the top of the abrasion tester. Next, the surface of the scratch-resistant layer of the exterior material for an electric storage device was rubbed back and forth with the cloth 200 times. The abrasion conditions were a load of approximately 500 gf and 1 reciprocation per second. The cloth was soaked with 10 drops of ethanol, and 10 drops of ethanol were added to the cloth every 50 reciprocations. After the abrasion was completed, the exterior material for an electric storage device was removed from the abrasion resistance evaluation device, and the condition of the rubbed area was visually inspected and evaluated using a single evaluation standard. The results are shown in Table 1. (Evaluation criteria) A: No injuries were found. B: Scratches were found, but there were less than 10 scratches. C: More than 10 scratches were found.

[0180] <Formability evaluation> The exterior material for the energy storage device was cut into strips measuring 120 mm in the TD direction x 80 mm in the MD direction, which were used as test samples. A rectangular male mold measuring 31.6 mm in the MD direction x 54.5 mm in the TD direction (the surface conforms to JIS B 0659-1:2002 Appendix 1 (Reference)) was used for comparison. The test sample was placed on the female mold with a clearance of 0.3 mm between it and the male mold (the surface has a maximum height roughness (nominal value of Rz) of 3.2 μm, as specified in Table 2 of the surface roughness standard for comparison in JIS B 0659-1:2002, Appendix 1 (Reference), corner R2.0 mm, ridge R1.0 mm), and the test sample was cold-formed (single-stage drawing) while being pressed with a pressure (surface pressure) of 0.1 MPa. The corners of the recesses of the molded test samples were observed with a scanning electron microscope to examine the outermost layers (the scratch-resistant layers in Examples 1 and 2 and Comparative Example 1, and the substrate protective layer in Comparative Example 2), and the moldability was evaluated according to the following criteria. The results are shown in Table 1. (Evaluation criteria) A: No cracks were observed. B: Cracks were observed, but the base layer was not exposed. C: Cracks were observed, and the substrate layer was exposed.

[0181] [Table 1]

[0182] The exterior packaging materials for electricity storage devices of Examples 1 and 2 are composed of a laminate having, in this order, a scratch-resistant layer, a substrate protective layer, a substrate layer, a barrier layer, and a heat-sealable resin layer, the scratch-resistant layer contains inorganic particles and a resin, the combined film thickness of the scratch-resistant layer and the substrate protective layer is 10 μm or less, the materials have excellent scratch resistance, and cracks at the corners due to molding are effectively suppressed.

[0183] As described above, the present disclosure provides the following aspects of the invention. Item 1. The laminate is composed of at least a scratch-resistant layer, a substrate protective layer, a substrate layer, a barrier layer, and a heat-sealable resin layer in this order, the scratch-resistant layer contains inorganic particles and a resin, The exterior material for an electricity storage device, wherein the average film thickness of the scratch-resistant layer and the base material protective layer combined is 10 μm or less. Item 2. The packaging material for an electricity storage device according to Item 1, wherein the scratch-resistant layer contains particles having a particle diameter larger than the average film thickness of the scratch-resistant layer. Item 3. The packaging material for a storage battery device according to Item 1 or 2, wherein the substrate protective layer contains particles having a particle diameter larger than the average film thickness of the substrate protective layer. Item 4. The exterior packaging material for an electricity storage device according to Item 2 or 3, wherein the particle diameter of the large particles is 1.0 μm or more and 5.0 μm or less in a cross section in the thickness direction of the scratch-resistant layer and the base protective layer, as observed with a scanning electron microscope. Item 5. The packaging material for an electricity storage device according to any one of Items 2 to 4, wherein, when the hardness of the large particles and the resin in a cross section in the thickness direction of the scratch-resistant layer is measured by a nanoindentation method in a 23°C environment, the hardness of the large particles is greater than the hardness of the resin. Item 6. The packaging material for an electricity storage device according to any one of Items 2 to 5, wherein the difference in hardness between the large particles and the resin is 100 MPa or more. Item 7. The exterior packaging material for an electricity storage device according to any one of Items 2 to 6, wherein the large particles in a cross section in the thickness direction of the scratch-resistant layer have a hardness of 400 MPa or more as measured by a nanoindentation method in a 23°C environment. Item 8. The packaging material for an electricity storage device according to any one of Items 2 to 7, wherein the large particles are organic particles. Item 9. The packaging material for an electricity storage device according to any one of Items 1 to 8, wherein the scratch-resistant layer and the base material protective layer each contain different resins. Item 10. The packaging material for an electricity storage device according to any one of Items 1 to 9, wherein, when hardness is measured by nanoindentation in a 23°C environment for a cross section in the thickness direction of the scratch-resistant layer and the base protective layer, respectively, the hardness of the resin of the scratch-resistant layer is greater than the hardness of the resin of the base protective layer. Section 11. Item 11. The packaging material for a power storage device according to Item 10, wherein the difference in hardness between the resin of the scratch-resistant layer and the resin of the base material protective layer is 100 MPa or more. Item 12. The packaging material for an electricity storage device according to any one of Items 1 to 11, wherein the hardness of the resin measured by nanoindentation in a 23°C environment on a cross section in the thickness direction of the scratch-resistant layer is 150 MPa or more. Item 13. The exterior packaging material for an electricity storage device according to any one of Items 1 to 12, wherein the resin hardness measured by nanoindentation in a 23°C environment for a cross section in the thickness direction of the base protective layer is 150 MPa or less. Item 14. The packaging material for an electricity storage device according to any one of Items 1 to 13, wherein the inorganic particles in the scratch-resistant layer are silica particles. Item 15. The packaging material for an electricity storage device according to any one of Items 1 to 14, wherein the base material protective layer contains inorganic particles and a resin. Item 16. The exterior packaging material for a power storage device according to Item 15, wherein the inorganic particles of the base material protective layer are barium sulfate. Item 17. The packaging material for an electricity storage device according to any one of Items 1 to 16, wherein the scratch-resistant layer has an average thickness of 2.5 μm or less. Item 18. The packaging material for an electricity storage device according to any one of Items 1 to 17, wherein the base material protective layer has an average thickness of 2.0 μm or less. Item 19. The method includes a step of laminating at least a scratch-resistant layer, a substrate protective layer, a substrate layer, a barrier layer, and a heat-sealable resin layer in this order to obtain a laminate, the scratch-resistant layer contains inorganic particles and a resin, A method for producing an exterior material for an electricity storage device, wherein the average film thickness of the scratch-resistant layer and the base material protective layer combined is 10 μm or less. Item 20. 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 18. [Explanation of symbols]

[0184] 1 Base material layer 2 Adhesive layer 3 Barrier layer 4 Heat-fusible resin layer 5 Adhesive layer 6 Base material protective layer 7 Scratch resistant layer 10. Exterior materials for energy storage devices 61,71 Inorganic particles 62,72 organic particles

Claims

1. The laminate is composed of at least a scratch-resistant layer, a substrate protective layer, a substrate layer, a barrier layer, and a heat-sealable resin layer, in this order; the scratch-resistant layer contains inorganic particles and a resin, the average thickness of the scratch-resistant layer and the substrate protective layer combined is 10 μm or less; The exterior material for an electricity storage device, wherein the base material protective layer is formed from at least one of an epoxy resin and a polyurethane.

2. The laminate is composed of at least a scratch-resistant layer, a substrate protective layer, a substrate layer, a barrier layer, and a heat-sealable resin layer, in this order; the scratch-resistant layer contains inorganic particles and a resin, the average thickness of the scratch-resistant layer and the substrate protective layer combined is 10 μm or less; The exterior material for an electricity storage device, wherein the scratch-resistant layer is formed from at least one of an epoxy resin and a polyurethane.

3. The packaging material for an electricity storage device according to claim 1 or 2, wherein the scratch-resistant layer contains particles having a particle diameter larger than an average film thickness of the scratch-resistant layer.

4. 4. The exterior material for an electricity storage device according to claim 3, wherein when the hardness of the large particles and the resin in a cross section in the thickness direction of the scratch-resistant layer is measured by a nanoindentation method in an environment of 23°C, the hardness of the large particles is greater than the hardness of the resin.

5. The packaging material for an electricity storage device according to claim 3 or 4, wherein a difference in hardness between the large particles of the scratch-resistant layer and the resin of the scratch-resistant layer is 100 MPa or more.

6. The large particles in a cross section in the thickness direction of the scratch-resistant layer have a hardness measured by a nanoindentation method in a 23 ° C. environment of 400 MPa or more. The exterior material for a storage battery device according to any one of claims 3 to 5.

7. The packaging material for an electricity storage device according to any one or more of claims 1 to 6, wherein the substrate protective layer contains particles having a particle diameter larger than the average film thickness of the substrate protective layer.

8. The scratch-resistant layer and the base protective layer have a cross section in the thickness direction, and the particle diameter of the large particles observed with a scanning electron microscope is 1.0 μm or more and 5.0 μm or less. The exterior material for a storage battery device according to any one of claims 3 to 7.

9. The packaging material for an electricity storage device according to any one of claims 3 to 8, wherein the large particles are organic particles.

10. The packaging material for an electricity storage device according to any one of claims 1 to 9, wherein the scratch-resistant layer and the base material protective layer each contain different resins.

11. When the hardness of each of the scratch-resistant layer and the base protective layer is measured by a nanoindentation method in a thickness direction cross section in a 23 ° C. environment, the hardness of the resin of the scratch-resistant layer is greater than the hardness of the resin of the base protective layer. The exterior material for a storage battery device according to any one of claims 1 to 10.

12. The packaging material for an electricity storage device according to claim 11, wherein a difference in hardness between the resin of the scratch-resistant layer and the resin of the base material protective layer is 100 MPa or more.

13. The hardness of the resin measured by a nanoindentation method on a cross section in the thickness direction of the scratch-resistant layer in a 23 ° C. environment is 150 MPa or more. The exterior material for a storage battery device according to any one of claims 1 to 12.

14. 14. The electrical storage device packaging material according to any one of claims 1 to 13, wherein the hardness of the resin measured by a nanoindentation method on a cross section in the thickness direction of the substrate protective layer in a 23 ° C. environment is 150 MPa or less.

15. The packaging material for an electricity storage device according to any one of claims 1 to 14, wherein the inorganic particles in the scratch-resistant layer are silica particles.

16. The packaging material for an electricity storage device according to any one of claims 1 to 15, wherein the substrate protective layer contains inorganic particles and a resin.

17. The packaging material for an electricity storage device according to claim 16, wherein the inorganic particles in the base protective layer are barium sulfate.

18. The packaging material for an electricity storage device according to any one of claims 1 to 17, wherein the scratch-resistant layer has an average film thickness of 2.5 µm or less.

19. The packaging material for an electricity storage device according to any one of claims 1 to 18, wherein the base material protective layer has an average film thickness of 2.0 µm or less.

20. The packaging material for an electricity storage device according to any one of claims 1 to 19, wherein the packaging material for an electricity storage device is colored.

21. The electrical storage device exterior packaging material according to any one of claims 1 to 20, wherein at least one of the scratch-resistant layer and the substrate protective layer contains a colorant.

22. an adhesive layer between the substrate layer and the barrier layer; The packaging material for an electricity storage device according to any one of claims 1 to 21, wherein the adhesive layer contains a colorant.

23. The packaging material for an electricity storage device according to any one of claims 1 to 22, further comprising a colored layer between the base material layer and the barrier layer.

24. The packaging material for an electricity storage device according to any one of claims 1 to 23, wherein the barrier layer includes at least one of an aluminum alloy foil and a stainless steel foil.

25. an adhesive layer is provided between the barrier layer and the heat-sealable resin layer, The packaging material for an electricity storage device according to any one of claims 1 to 24, wherein the adhesive layer has a thickness of 20 µm or less.

26. an adhesive layer is provided between the barrier layer and the heat-sealable resin layer, The packaging material for an electricity storage device according to any one of claims 1 to 24, wherein the adhesive layer has a thickness of more than 20 µm and not more than 50 µm.

27. an adhesive layer is provided between the barrier layer and the heat-sealable resin layer, The adhesive layer is a cured product of a resin composition containing an acid-modified polyolefin and at least one selected from the group consisting of a compound having an isocyanate group, a compound having an oxazoline group, and a compound having an epoxy group. The exterior material for a storage battery device according to any one of claims 1 to 26.

28. an adhesive layer is provided between the barrier layer and the heat-sealable resin layer, The packaging material for an electricity storage device according to any one of claims 1 to 27, wherein the adhesive layer contains at least one selected from the group consisting of polyurethane, polyester, and epoxy resin.

29. The method includes a step of laminating at least a scratch-resistant layer, a substrate protective layer, a substrate layer, a barrier layer, and a heat-fusible resin layer in this order to obtain a laminate, the scratch-resistant layer contains inorganic particles and a resin, the average thickness of the scratch-resistant layer and the substrate protective layer combined is 10 μm or less; The method for producing an exterior material for an electricity storage device, wherein the base material protective layer is formed from at least one of an epoxy resin and a polyurethane.

30. The method includes a step of laminating at least a scratch-resistant layer, a substrate protective layer, a substrate layer, a barrier layer, and a heat-fusible resin layer in this order to obtain a laminate, the scratch-resistant layer contains inorganic particles and a resin, the average thickness of the scratch-resistant layer and the substrate protective layer combined is 10 μm or less; The method for producing an exterior material for an electricity storage device, wherein the scratch-resistant layer is formed from at least one of an epoxy resin and a polyurethane.

31. 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 28.

Images