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

Abstract

An exterior material for a power storage device composed of a laminate including, in order from the outside, at least a substrate layer, a barrier layer, and a hot-melt resin layer, wherein the substrate layer contains a polyester resin layer, and the polyester resin layer has a thickness of 20 μm or more.

Description

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

[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.

[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 material layer, a barrier layer, and a heat-sealable resin layer are laminated in this order from the outside 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.

[0006] Japanese Patent Application Laid-Open No. 2008-287971

[0007] As described above, a film-like laminate in which a base layer, a barrier layer, and a heat-sealable resin layer are laminated in this order from the outside is known as an exterior material for an electricity storage device. In an exterior material for an electricity storage device made of such a film-like laminate, high adhesive strength between layers is required.

[0008]

[0003] The inventors of the present disclosure have found through their investigations that when a moisture-absorbing electrical storage device packaging material is subjected to the above-described heat fusion, the absorbed moisture evaporates and bubbles are generated within or between layers outside the barrier layer. It has been confirmed that this phenomenon is particularly likely to occur when, for example, in order to improve the production efficiency of electrical storage device packaging materials, the drying time of the electrical storage device packaging material is shortened, the temperature during heat fusion of the electrical storage device packaging material is increased to shorten the heat fusion time, or a large amount of a highly hygroscopic material (e.g., polyamide resin) is used outside the barrier layer of the electrical storage device packaging material. The generation of bubbles within or between layers outside the barrier layer causes a problem of weakening the adhesive strength between layers outside the barrier layer (e.g., between the substrate layer and the barrier layer).

[0009] Under these circumstances, a main object of the present disclosure is to provide an exterior packaging material for an electricity storage device that is composed of a laminate including, in order from the outside, at least a base material layer, a barrier layer, and a heat-sealable resin layer, and that, when the exterior packaging material for an electricity storage device is heat-sealed, suppresses the generation of bubbles within and / or between layers outside the barrier layer.

[0010] The inventors of the present disclosure conducted extensive research to solve the above-described problems, and as a result, found that in a packaging material for an electricity storage device including a laminate including, in order from the outside, at least a base material layer, a barrier layer, and a heat-sealable resin layer, by using a polyester resin layer having a thickness of 20 μm or more as the base material layer, when the packaging material for an electricity storage device is heat-sealed, the generation of bubbles in and / or between layers outside the barrier layer is suppressed.

[0011] The present disclosure has been completed based on these findings and through further investigations. That is, the present disclosure provides the following aspects of the invention: An exterior packaging material for an electricity storage device, comprising a laminate including, in order from the outside, at least a base material layer, a barrier layer, and a heat-sealable resin layer, the base material layer including a polyester resin layer, and the polyester resin layer having a thickness of 20 μm or more.

[0012] According to the present disclosure, it is possible to provide a packaging material for an electricity storage device that is composed of a laminate including, in order from the outside, at least a base material layer, a barrier layer, and a heat-sealable resin layer, in which, when the packaging material for an electricity storage device is heat-sealed, the generation of bubbles in and / or between layers outside the barrier layer is suppressed. Furthermore, according to the present disclosure, it is also possible to provide a method for manufacturing the packaging material for an electricity storage device, and an electricity storage device that uses the packaging material for an electricity storage device.

[0013] FIG. 1 is a schematic diagram showing an example of the cross-sectional structure of an exterior material for an electricity storage device according to the present disclosure. FIG. 2 is a schematic diagram showing an example of the cross-sectional structure of an exterior material for an electricity storage device according to the present disclosure. FIG. 3 is a schematic diagram showing an example of the cross-sectional structure of an exterior material for an electricity storage device according to the present disclosure. FIG. 4 is a schematic diagram showing an example of the cross-sectional structure of an exterior material for an electricity storage device according to the present disclosure. FIG. 5 is a schematic diagram for explaining a method of housing an electricity storage device element in a package formed from an exterior material for an electricity storage device according to the present disclosure. FIG. 6 is a schematic diagram for explaining a method of measuring the seal strength of an exterior material for an electricity storage device when heat-sealed at 210°C. FIG. 7 is a schematic diagram for explaining a method of measuring the seal strength of an exterior material for an electricity storage device when heat-sealed at 210°C.

[0014] The packaging material for an electricity storage device according to the present disclosure is composed of a laminate including, in order from the outside, at least a base material layer, a barrier layer, and a heat-sealable resin layer, the base material layer including a polyester resin layer, and the polyester resin layer having a thickness of 20 μm or more. Due to the configuration of the packaging material for an electricity storage device according to the present disclosure, when the packaging material for an electricity storage device is heat-sealed, the generation of bubbles in and / or between layers outside the barrier layer is suppressed.

[0015] The exterior packaging material for an electricity storage device of the present disclosure will be described in detail below. Note that in this disclosure, a numerical range indicated by "to" means "greater than or equal to" or "less than or equal to." For example, the notation 2 to 15 mm means 2 mm or more and 15 mm or less. In the numerical ranges described in stages in this disclosure, the upper or lower limit value described in a certain numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. Furthermore, separately described upper and lower limits, upper and lower limits, or lower and lower limits may each be combined to form a numerical range. Furthermore, in the numerical ranges described in this disclosure, the upper or lower limit value described in a certain numerical range may be replaced with a value shown in the examples.

[0016] 1. Laminated Structure and Physical Properties of the Electricity Storage Device Exterior Material The electricity storage device exterior material 10 of the present disclosure is composed of a laminate including, for example, a base material layer 1, a barrier layer 3, and a heat-sealable resin layer 4 in this order, as shown in FIG. 1 . In the electricity storage device exterior material 10, the base material layer 1 is the outermost layer, and the heat-sealable resin layer 4 is the innermost layer. When assembling an electricity storage device using the electricity storage device exterior material 10 and an electricity storage device element, the heat-sealable resin layers 4 of the electricity storage device exterior material 10 are placed opposite each other, and the peripheries are heat-sealed to form a space, in which the electricity storage device element is housed. In the laminate constituting the electricity storage device exterior material 10 of the present disclosure, with the barrier layer 3 as the reference, the heat-sealable resin layer 4 side is on the inner side relative to the barrier layer 3, and the base material layer 1 side is on the outer side relative to the barrier layer 3.

[0017] In the present disclosure, the substrate layer 1 includes a polyester resin layer 11. For example, as shown in FIGS. 1 to 5 , the substrate layer 1 may be configured with a single layer of the polyester resin layer 11, or may further include a resin layer 12 in addition to the polyester resin layer 11. The resin layer 12 may be a layer formed of a polyester resin, or may be a layer formed of a resin different from the polyester resin. When the substrate layer 1 includes the resin layer 12, the polyester resin layer 11 and the resin layer 12 may be laminated directly or via an adhesive layer 12a. Furthermore, from the viewpoint of more suitably exhibiting the effects of the present disclosure, when the substrate layer 1 includes the resin layer 12, it is preferable that the polyester resin layer 11 be located outside the resin layer 12.

[0018] As shown in Figures 3 to 5, for example, 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. Furthermore, as shown in Figures 4 and 5, for example, the packaging material 10 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. Furthermore, as shown in Figure 5, a surface coating layer 6 or the like may be provided on the outer side of the base material layer 1 (the side opposite to the heat-sealable resin layer 4 side), if necessary.

[0019] The thickness of the laminate constituting the electrical storage device exterior material 10 is not particularly limited, but from the viewpoint of cost reduction, improving energy density, etc., examples of the thickness include about 300 μm or less, about 260 μm or less, about 210 μm or less, and preferably about 190 μm or less, about 180 μm or less, about 155 μm or less, and about 120 μm or less. Furthermore, from the viewpoint of maintaining the function of the electrical storage device exterior material to protect the electrical storage device elements, the thickness of the laminate constituting the electrical storage device exterior material 10 is preferably about 35 μm or more, about 45 μm or more, about 60 μm or more, about 155 μm or more, and about 160 μm or more. Furthermore, preferred ranges for the laminate constituting the exterior packaging material 10 for an electricity storage device are, for example, about 35 to 300 μm, about 35 to 260 μm, about 35 to 210 μm, about 35 to 190 μm, about 35 to 180 μm, about 35 to 155 μm, about 35 to 120 μm, about 45 to 300 μm, about 45 to 260 μm, about 45 to 210 μm, about 45 to 190 μm, about 45 to 180 μm, about 45 to 155 μm, about 45 to 120 μm, about 60 to 300 μm, about 60 to 260 μm, about 60 to 210 μm, and about 60 to 1 Examples of the thickness include about 90 μm, about 60 to 180 μm, about 60 to 155 μm, about 60 to 120 μm, about 155 to 300 μm, about 155 to 260 μm, about 155 to 210 μm, about 155 to 190 μm, about 155 to 180 μm, about 160 to 300 μm, about 160 to 260 μm, about 160 to 210 μm, about 160 to 190 μm, and about 160 to 180 μm. In particular, when making the power storage device lightweight and thin, about 60 to 155 μm is preferred, and when improving formability, about 155 to 260 μm is preferred.

[0020] In the electrical storage device packaging material 10, the ratio of the total thickness of the base material layer 1, the adhesive layer 2 (which is provided as needed), the barrier layer 3, the adhesive layer 5 (which is provided as needed), the heat-sealable resin layer 4, and the surface coating layer 6 (which is provided as needed) 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 base material layer 1, the adhesive layer 2, the barrier layer 3, the adhesive layer 5, and the 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 electrical storage device packaging material 10 of the present disclosure is a laminate including 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 electrical storage device packaging material 10 can be, for example, 80% or more, preferably 90% or more, more preferably 95% or more, and even more preferably 98% or more.

[0021] The exterior packaging material for an electricity storage device according to the present disclosure has a moisture content of preferably about 2700 ppm or less, more preferably about 2500 ppm or less, even more preferably about 2000 ppm or less, and still more preferably 1000 ppm or less when exposed to an environment of a temperature of 25°C and a relative humidity of 50% for 24 hours. The lower limit can be, for example, about 0 ppm, about 100 ppm, or about 200 ppm, with a preferred range being about 0 ppm to 2700 ppm. Examples of the water content include approximately 0 ppm to 2500 ppm, approximately 0 ppm to 2000 ppm, approximately 0 ppm to 1000 ppm, approximately 100 ppm to 2700 ppm, approximately 100 ppm to 2500 ppm, approximately 100 ppm to 2000 ppm, approximately 100 ppm to 1000 ppm, approximately 200 ppm to 2700 ppm, approximately 200 ppm to 2500 ppm, approximately 200 ppm to 2000 ppm, and approximately 200 ppm to 1000 ppm. In the outer packaging material for an electricity storage device of the present disclosure, the substrate layer 1 located on the outside includes a polyester resin layer 11 having a thickness of 20 μm or more. The polyester resin contained in the polyester resin layer 11 has low water absorption and can suppress moisture penetration from the outside of the substrate layer 1 toward the barrier layer 3. For this reason, the packaging material for an electricity storage device according to the present disclosure can achieve the above-described low moisture content when exposed to an environment at a temperature of 25° C. and a relative humidity of 50%. The moisture content of the packaging material for an electricity storage device when exposed to an environment at a temperature of 25° C. and a relative humidity of 50% for 24 hours is measured by the following procedure.

[0022] <Moisture Content of Electricity Storage Device Exterior Material> To eliminate the influence of water infiltration from the end faces, the sample (electricity storage device exterior material) to be measured was prepared by storing a 300 mm x 300 mm sample for 24 hours in an environment with a temperature of 25°C, a relative humidity of 1% or less, and a dew point of -20°C or less, followed by storing it for 24 hours in an environment with a temperature of 25°C and a relative humidity of 50%, and then cutting out a 100 mm x 100 mm sample from the center. The moisture content was measured by the moisture vaporization-coulometric titration method using a Karl Fischer moisture meter and evaporator placed in an environment with a temperature of 25°C, a relative humidity of 1% or less, and a dew point of -20°C or less. To minimize the influence of the measurement environment, the sample was wrapped in packaging that could block the outside air and brought into the measurement environment. After removal from the packaging, the sample was placed in the measurement device within 30 minutes. The measurement conditions were as follows: Measurement target component: water, titration cell type: two-liquid cell, detection electrode type: bipolar platinum electrode, diaphragm material: ceramic, endpoint detection method: AC polarization method using bipolar platinum detection electrode, endpoint determination method: drift stability determination, heating temperature: 180°C, cell purge time: 120 seconds, back purge time: 180 seconds, stability determination value: 0.1 μg / min, endpoint potential: 200 mV. Measurement results are calculated as the ratio of water weight to sample weight (unit: ppm), and the average value of three measurements is reported, rounded to the nearest tenth. Commercially available anolyte and catholyte are used as titration reagents.

[0023] Furthermore, the electrical storage device packaging material of the present disclosure, obtained by the same method as the method in <Moisture content of electrical storage device packaging material> above, and exposed to an environment at a temperature of 25°C and a relative humidity of 50% for 24 hours, preferably has a seal strength of about 120 N / 15 mm or more, more preferably about 140 N / 15 mm or more, and even more preferably about 160 N / 15 mm or more when heat-sealed at a temperature of 210°C. The upper limit is, for example, 200 N / 15 mm. Examples of the seal strength include about 15mm, 190N / 15mm, and 180N / 15mm, and preferred ranges include about 120 to 200N / 15mm, about 120 to 190N / 15mm, about 120 to 180N / 15mm, about 140 to 200N / 15mm, about 140 to 190N / 15mm, about 140 to 180N / 15mm, about 160 to 200N / 15mm, about 160 to 190N / 15mm, and about 160 to 180N / 15mm. The method for measuring the seal strength is as follows.

[0024] <Seal Strength of Sheathing Materials for Electrical Storage Devices When Heat-Sealed at 210°C> In accordance with JIS K7127:1999, battery packaging materials were prepared by cutting them into strips 15 mm wide in the transverse direction as test pieces. Specifically, as shown in FIG. 7, each battery packaging material was first cut into 60 mm (transverse direction) x 200 mm (machine direction) pieces (FIG. 7a). Next, the battery packaging material was folded in half in the machine direction at fold P (midway in the machine direction) so that the heat-sealable resin layers faced each other (FIG. 7b). The heat-sealable resin layers were heat-sealed approximately 10 mm inward from fold P under conditions of a seal width of 7 mm, a temperature of 210°C, a surface pressure of 1.0 MPa, and a duration of 3 seconds (FIG. 7c). In FIG. 7c, the shaded area S indicates the heat-sealed area. Next, the specimen 13 was cut in the machine direction (cut at the two-dot chain line in Figure 7d) to a width of 15 mm in the transverse direction to obtain a test piece (Figure 7e). The test piece 13 was then left at each measurement temperature for 2 minutes, and the heat-sealable resin layer of the heat-sealed portion was peeled off at a rate of 300 mm / min using a tensile tester under each temperature environment (Figure 8). The maximum strength at the time of peeling was taken as the seal strength (N / 15 mm). The distance between the chucks was 50 mm. The average value of three measurements was used. Note that in measuring the seal strength, the test piece 13 may peel off (fracture) at the heat-seal interface A shown in Figure 8, or may fracture at a location other than the heat-seal interface A (e.g., location B in Figure 8).

[0025] <Presence or Absence of Foaming Outside Barrier Layer of Electricity Storage Device Exterior Material During Heat Fusion> When the exterior material for an electricity storage device according to the present disclosure is used as the subject of measurement for the above-described <Seal strength of exterior material for an electricity storage device when heat-fused at 210°C>, layers (substrate layer 1, adhesive layer 2, etc.) located outside the barrier layer 3 are observed and the presence or absence of bubbles is visually confirmed, and it is preferred that no bubbles are observed in each layer or between the layers.

[0026] Furthermore, when the molding depth of the electrical storage device packaging material of the present disclosure, obtained in <Moisture content of electrical storage device packaging material> above and exposed to an environment of a temperature of 25°C and a relative humidity of 50% for 24 hours, is measured under the following conditions, the molding depth is preferably about 10 mm or more, more preferably about 15 mm or more, and even more preferably about 19 mm or more. The upper limit can be, for example, about 32 mm, about 30 mm, or about 28 mm. Preferred ranges include about 10 to 32 mm, about 10 to 30 mm, about 10 to 28 mm, about 15 to 32 mm, about 15 to 30 mm, about 15 to 28 mm, about 19 to 32 mm, about 19 to 30 mm, and about 19 to 28 mm.

[0027] <Forming depth of exterior material for electricity storage device> Each exterior material for electricity storage device was cut into a square with a length (MD direction) of 200 mm and a width (TD direction) of 200 mm to prepare a test sample. The MD of the exterior material for electricity storage device corresponds to the rolling direction (RD) of the aluminum alloy foil, and the TD of the exterior material for electricity storage device corresponds to the TD of the aluminum alloy foil. This sample was placed in a 25°C environment in a rectangular molding die (female die, the surface of which had 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, Annex 1 (Reference), corner R2.0 mm, ridge R1.0 mm) with a bore of 100 mm (MD) x 110 mm (TD) and a corresponding molding die (male die, the surface of the ridgeline had a maximum height roughness (nominal value of Rz) of 1.6 μm as specified in Table 2 of the surface roughness standard for comparison in JIS B 0659-1:2002, Annex 1 (Reference), and the surface other than the ridgeline had a maximum height roughness (nominal value of Rz) of 1.6 μm as specified in Table 2 of the surface roughness standard for comparison in JIS B 0659-1:2002, Annex 1 (Reference), The maximum height roughness (nominal Rz value) specified in Table 2 of the comparative surface roughness standard piece is 3.2 μm. Using a corner R2.0 mm, ridge R1.0 mm), cold forming (single-stage drawing) was performed on 10 samples each, changing the forming depth in 0.5 mm increments from a forming depth of 0.5 mm at a pressing pressure (surface pressure) of 0.25 MPa. At this time, the test sample was placed on a female mold so that the heat-fusible resin layer side was located on the male mold side. The clearance between the male mold and the female mold was 0.3 mm. After cold forming, the sample was irradiated with a penlight in a dark room to check whether pinholes or cracks had occurred in the aluminum foil due to light transmission. The deepest molding depth at which no pinholes or cracks occurred in the aluminum foil in any of the 10 samples was defined as A mm, and the number of samples at which pinholes or the like occurred in the aluminum foil at the shallowest molding depth was defined as B. The value calculated using the following formula was rounded to two decimal places to determine the limit molding depth of the exterior material for an electricity storage device. Limit molding depth = A mm + (0.5 mm / 10 samples) × (10 samples - B samples).

[0028] Furthermore, in the electrical storage device packaging material of the present disclosure, A / (the maximum value among A, B, and C), B / (the maximum value among A, B, and C), and C / (the maximum value among A, B, and C), which are calculated by the following tensile test, are preferably all within the range of 0.40 to 1.00, thereby providing a good balance with respect to tensile stress in the electrical storage device packaging material and enabling it to exhibit high formability.

[0029] <Tensile Test of Sheathing Material for Electricity Storage Device> A tensile test was performed on each of the sheathing materials for electricity storage devices under the following conditions, measuring the tensile strength (N / 15 mm) at 25 mm displacement and the tensile strength (N / 15 mm) at 10 mm displacement in the MD direction, TD direction, and 45° direction (45° clockwise from the MD direction). Next, the difference (| tensile strength at 25 mm displacement - tensile strength at 10 mm displacement |) between the tensile strength at 25 mm displacement (N / 15 mm) and the tensile strength at 10 mm displacement (N / 15 mm) for each of the MD direction, TD direction, and 45° direction was calculated. Furthermore, these differences were divided by the displacement difference of 15 mm (25 mm - 10 mm), and the respective values ​​were designated as MD direction: A, TD direction: B, and 45° direction: C. The maximum value of A, B, and C is used as the denominator to divide each value of A, B, and C (i.e., A / (maximum value of A, B, and C), B / (maximum value of A, B, and C) and C / (maximum value of A, B, and C)).

[0030] (Tensile test conditions) Measurement environment: 25°C, in air Distance between chucks: 30 mm (initial distance between chucks was the distance between gauge lines) Measurement speed: 50 mm / min Measurement sample width: 15 mm Measurement sample length: 100 mm Sample shape: rectangular

[0031] 2. Layers forming the packaging material for an electricity storage device [Substrate layer 1] In the present disclosure, the substrate layer 1 is a layer provided for the purpose of exhibiting the function as a substrate of the packaging material for an electricity storage device, etc. The substrate layer 1 is located on the outer layer side of the packaging material for an electricity storage device.

[0032] In the present disclosure, the substrate layer 1 includes a polyester resin layer 11. For example, as shown in Figures 1 to 5, the substrate layer 1 may be configured of a single layer of the polyester resin layer 11, or the substrate layer 1 may further include a resin layer 12 in addition to the polyester resin layer 11. The resin layer 12 may be a layer formed of a polyester resin, or may be a layer formed of a resin different from the polyester resin.

[0033] When the resin layer 12 is a layer formed from a resin other than polyester resin, different properties can be imparted to the base material layer 1 compared to when the base material layer 1 is formed solely from a polyester resin layer. For example, when the resin layer 12 is formed from a polyamide resin, polyamide resin has superior moldability compared to polyester resin, thereby improving the moldability of the entire electrical storage device packaging material. Polyamide resin has higher water absorption than polyester resin and is likely to cause the generation of bubbles due to the aforementioned heat fusion. However, in the electrical storage device packaging material of the present disclosure, the base material layer 1 includes a polyester resin layer 11 containing a polyester resin with low water absorption, with a thickness of 20 μm or more, and the polyester resin layer 11 can suppress the penetration of moisture from outside the barrier layer 3. Therefore, the electrical storage device packaging material of the present disclosure can achieve both the suppression of bubble generation and improved moldability.

[0034] When the base material layer 1 has the resin layer 12, the polyester resin layer 11 and the resin layer 12 may be laminated directly or via an adhesive layer 12 a. Furthermore, from the viewpoint of more suitably exerting the effects of the present disclosure, when the base material layer 1 has the resin layer 12, it is preferable that the polyester resin layer 11 is located outside the resin layer 12.

[0035] The polyester resin layer 11 is a resin layer containing polyester as a main component. Here, the term "main component" means that the polyester content of the resin components contained in the polyester resin layer 11 is, for example, 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, still more preferably 90% by mass or more, still more preferably 95% by mass or more, still more preferably 98% by mass or more, and still more preferably 99% by mass or more.

[0036] 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). Of these, polyethylene terephthalate is preferred. These polyesters may be used alone or in combination of two or more.

[0037] The polyester resin layer 11 can be formed, for example, from a polyester resin film. When the polyester resin layer 11 is formed from a polyester resin film, a preformed polyester resin film may be used as the polyester resin layer 11. Alternatively, the polyester forming the polyester resin layer 11 may be formed into a film on the surface of an adjacent layer by extrusion molding, coating, or the like, to form the polyester resin layer 11. The polyester 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 the polyester resin include roll coating, gravure coating, and extrusion coating.

[0038] The polyester resin layer 11 may be a single layer or may be composed of two or more layers. When the polyester resin layer 11 is composed of two or more layers, the polyester resin layer 11 may be a laminate obtained by laminating resin films with an adhesive or the like, or may be a laminate of polyester resin films formed by co-extrusion of resins into two or more layers. Furthermore, a laminate of polyester resin films formed by co-extrusion of resins into two or more layers may be used as the polyester resin layer 11 without being stretched, or may be uniaxially or biaxially stretched to form the polyester resin layer 11.

[0039] Additives such as lubricants, flame retardants, antiblocking agents, antioxidants, light stabilizers, tackifiers, antistatic agents, and colorants may be present on at least one of the surface and the interior of the polyester resin layer 11. Only one type of additive may be used, or two or more types may be mixed and used.

[0040] The thickness of the polyester resin layer 11 is not particularly limited as long as it is 20 μm or more and does not impair the effects of the present disclosure. From the viewpoint of more suitably exhibiting the effects of the present disclosure, the thickness of the polyester resin layer 11 is preferably about 22 μm or more, about 25 μm or more, about 27 μm or more, more preferably about 30 μm or more, about 32 μm or more, and even about 35 μm or more, and is also preferably about 100 μm or less, more preferably about 78 μm or less, even more preferably about 75 μm or less, and even more preferably about 50 μm or less, and preferred ranges are about 22 to 100 μm, about 22 to 78 μm, about 22 to 75 μm, and about 22 to 50 μm. Examples include about 25 to 100 μm, about 25 to 78 μm, about 25 to 75 μm, about 25 to 50 μm, about 27 to 100 μm, about 27 to 78 μm, about 27 to 75 μm, about 27 to 50 μm, about 30 to 100 μm, about 30 to 78 μm, about 30 to 75 μm, about 30 to 50 μm, about 32 to 100 μm, about 32 to 78 μm, about 32 to 75 μm, about 32 to 50 μm, about 35 to 100 μm, about 35 to 78 μm, about 35 to 75 μm, and about 35 to 50 μm. In addition, when the polyester resin layer 11 is composed of two or more layers, and the thickness of each polyester resin layer is less than 20 μm, but the total thickness of the multiple polyester resin layers is 20 μm or more, the thickness of the polyester resin layer 11 is the total thickness of the multiple layers.

[0041] When the substrate layer 1 further includes a resin layer 12 in addition to the polyester resin layer 11, the material forming the resin layer 12 is not particularly limited as long as it has the function of a substrate, i.e., at least insulating properties.

[0042] The resin layer 12 can be formed, for example, from a resin film. When the resin layer 12 is formed from a resin film, a preformed resin film may be used as the resin layer 12 when laminating the resin layer 12 with the polyester resin layer 11, the barrier layer 3, etc. to produce the electrical storage device packaging material 10 of the present disclosure. Alternatively, the resin forming the resin layer 12 may be formed into a film on the surface of the polyester resin layer 11, the barrier layer 3, etc. by extrusion molding, coating, etc., to form the resin layer 12 formed from a resin film. 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 the resin include roll coating, gravure coating, and extrusion coating.

[0043] Examples of resins that form the resin layer 12 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 resin layer 12 may also be a copolymer of these resins, a modified version of the copolymer, or a mixture of these resins.

[0044] The resin layer 12 preferably contains these resins as a main component, and more preferably contains polyamide as a main component. Here, "main component" means that the content of the resin component contained in the resin layer 12 is, for example, 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, even more preferably 98% by mass or more, and even more preferably 99% by mass or more. For example, "the resin layer 12 contains polyamide as a main component" means that the content of polyamide among the resin components contained in the resin layer 12 is, for example, 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, even more preferably 98% by mass or more, and even more preferably 99% by mass or more.

[0045] 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) containing structural units derived from terephthalic acid and / or isophthalic acid; and aromatic polyamides such as polyamide MXD6 (polymetaxylylene adipamide); alicyclic polyamides such as polyamide PACM6 (polybis(4-aminocyclohexyl)methane adipamide); polyamides copolymerized with a lactam component or an isocyanate component such as 4,4'-diphenylmethane-diisocyanate; polyesteramide copolymers and polyetheresteramide copolymers, which are copolymers of copolymerized polyamides with polyesters or polyalkylene ether glycols; and polyamides such as copolymers of these copolymers. These polyamides may be used alone or in combination of two or more.

[0046] The resin layer 12 may be a single layer or may be composed of two or more layers. When the resin layer 12 is composed of two or more layers, the resin layer 12 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 resin layer 12 without being stretched, or may be uniaxially or biaxially stretched to form the resin layer 12.

[0047] Additives such as lubricants, flame retardants, antiblocking agents, antioxidants, light stabilizers, tackifiers, antistatic agents, and colorants may be present on at least one of the surface and the interior of the resin layer 12. Only one type of additive may be used, or two or more types may be mixed and used.

[0048] From the viewpoint of more suitably exerting the effects of the present disclosure, the thickness of the resin layer 12 is preferably about 7 μm or more, about 12 μm or more, about 15 μm or more, more preferably about 20 μm or more, and even more preferably about 25 μm or more, and is also preferably about 50 μm or less, more preferably about 40 μm or less, even more preferably about 30 μm or less, and even more preferably about 25 μm or less, with preferred ranges being about 7 to 50 μm, and about 7 to 40 μm. , about 7 to 30 μm, about 7 to 25 μm, about 12 to 50 μm, about 12 to 40 μm, about 12 to 30 μm, about 12 to 25 μm, about 15 to 50 μm, about 15 to 40 μm, about 15 to 30 μm, about 15 to 25 μm, about 20 to 50 μm, about 20 to 40 μm, about 20 to 30 μm, about 20 to 25 μm, about 25 to 50 μm, about 25 to 40 μm, and about 25 to 30 μm. For example, when the resin layer 12 is composed of a polyamide resin film, it is preferable to satisfy these thicknesses from the viewpoint of suppressing the generation of bubbles in the exterior material for an electricity storage device while improving formability.

[0049] From the viewpoint of more suitably exerting the effects of the present disclosure, the ratio of the thickness of the polyester resin layer 11 to the thickness of the resin layer 12 (thickness of polyester resin layer 11 / thickness of resin layer 12) is preferably about 0.9 or more, more preferably about 1.0 or more, or about 1.5 or more, and is also preferably about 7.0 or less, more preferably about 6.0 or less, and preferred ranges include about 0.9 to 7.0, about 0.9 to 6.0, about 1.0 to 7.0, about 1.0 to 6.0, about 1.5 to 7.0, and about 1.5 to 6.0.

[0050] When the base material layer 1 is formed of a laminate of a polyester resin layer 11 and a resin layer 12, the laminate may be, as described above, a laminate in which the polyester resin layer 11 and the resin layer 12 are directly laminated together, or a laminate in which the polyester resin layer 11 and the resin layer 12 are laminated together via an adhesive layer 12a, with the latter being more preferred.

[0051] Examples of the adhesive that forms the adhesive layer 12a include the same adhesive as that that forms the adhesive layer 2, which will be described later.

[0052] The method for laminating the polyester resin layer 11 and the resin layer 12 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 for forming the adhesive layer 12a. Alternatively, an anchor coat layer may be formed on the polyester resin layer 11 or the resin layer 12 before lamination. Examples of the anchor coat layer include adhesives similar to those exemplified for the 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.

[0053] The thickness of the adhesive layer 12a is not particularly limited as long as it can bond the polyester resin layer 11 and the resin layer 12, but is, for example, about 1 μm or more, about 2 μm or more. The thickness of the adhesive layer 12a is, for example, about 10 μm or less, about 5 μm or less. Preferred ranges for the thickness of the adhesive layer 12a include about 1 to 10 μm, about 1 to 5 μm, about 2 to 10 μm, and about 2 to 5 μm.

[0054] The substrate layer 1 is preferably formed of a single layer of polyester resin layer 11, or a laminate of polyester resin layer 11 and polyamide resin-containing resin layer 12. As described above, the laminate of polyester resin layer 11 and polyamide resin-containing resin layer 12 may be one in which the polyester resin layer 11 and resin layer 12 are directly laminated together, or one in which the polyester resin layer 11 and resin layer 12 are laminated together via an adhesive layer 12a, the latter being more preferred.

[0055] Specific examples of the substrate layer 1 include a single layer of polyester resin film, a laminate of polyester resin film and nylon resin film, and a laminate of two or more layers of polyester resin film, with a laminate of a stretched polyester film and a stretched nylon film being preferred. For example, when the substrate layer 1 is a laminate of two resin films, a laminate of polyester resin film and polyester resin film, or a laminate of polyester resin film and polyamide resin film is preferred, and a laminate of polyethylene terephthalate film and polyethylene terephthalate film, or a laminate of polyethylene terephthalate film and nylon film is more preferred. Furthermore, since polyester resins have low moisture permeability, when the substrate 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 substrate layer 1.

[0056] 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.

[0057] Furthermore, additives such as lubricants, flame retardants, antiblocking agents, antioxidants, light stabilizers, tackifiers, antistatic agents, and colorants 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.

[0058] 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 at least one of the surface and the interior of the base material layer 1. The lubricant is not particularly limited, but preferably an amide-based lubricant is used. Specific examples of amide-based lubricants include saturated fatty acid amides, unsaturated fatty acid amides, substituted amides, methylolamides, saturated fatty acid bisamides, unsaturated fatty acid bisamides, fatty acid ester amides, and aromatic bisamides. Specific examples of saturated fatty acid amides include lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, and hydroxystearic acid amide. Specific examples of unsaturated fatty acid amides include oleic acid amide and erucic acid amide. Specific examples of substituted amides include N-oleyl palmitic acid amide, N-stearyl stearic acid amide, N-stearyl oleic acid amide, N-oleyl stearic acid amide, and N-stearyl erucic acid amide. Specific examples of methylolamides include methylol stearic acid amide. Specific examples of saturated fatty acid bisamides include methylene bisstearic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide, ethylene bisstearic acid amide, ethylene bishydroxystearic acid amide, ethylene bisbehenic acid amide, hexamethylene bisstearic acid amide, hexamethylene bisbehenic acid amide, hexamethylene hydroxystearic acid amide, N,N'-distearyl adipamide, N,N'-distearyl sebacic acid amide, etc. Specific examples of unsaturated fatty acid bisamides include ethylene bisoleic acid amide, ethylene biserucic acid amide, hexamethylene bisoleic acid amide, N,N'-dioleyl adipamide, N,N'-dioleyl sebacic acid amide, etc. Specific examples of fatty acid ester amides include stearamidoethyl stearate, etc. Specific examples of aromatic bisamides include m-xylylene bisstearic acid amide, m-xylylene bishydroxystearic acid amide, and N,N'-distearylisophthalic acid amide.The lubricant may be used alone or in combination of two or more kinds, and it is preferable to use a combination of two or more kinds.

[0059] When a lubricant is present on the surface of the base layer 1, the amount of the lubricant is not particularly limited, but may be, for example, about 3 mg / m 2 or more, preferably about 4 mg / m 2 Above, about 5mg / m 2 The amount of lubricant present on the surface of the base layer 1 is, for example, about 15 mg / m 2 or less, preferably about 14 mg / m 2 Below, about 10mg / m 2 The preferred range of the amount of lubricant present on the surface of the base layer 1 is 3 to 15 mg / m 2 Degree, 3-14mg / m 2 Degree, 3-10mg / m 2 Degree, 4-15mg / m 2 Degree, 4-14mg / m 2 degree, 4-10mg / m 2 degree, 5-15mg / m 2 Degree, 5-14mg / m 2 degree, 5-10mg / m 2 The degree of

[0060] The lubricant present on the surface of the base layer 1 may be a lubricant exuded from the resin constituting the base layer 1, or a lubricant applied to the surface of the base layer 1.

[0061] The thickness of the base layer 1 is not particularly limited as long as the polyester resin layer 11 is 20 μm or more and does not impair the effects of the present disclosure. From the viewpoint of more suitably exhibiting the effects of the present disclosure, the thickness of the base layer 1 is preferably about 22 μm or more, about 25 μm or more, more preferably about 40 μm or more, and even more preferably about 50 μm or more, and is also preferably about 100 μm or less, more preferably about 90 μm or less, even more preferably about 80 μm or less, and even more preferably about 75 μm or less, with preferred ranges being about 20 to 100 μm, about 20 to 90 μm, and about 20 to 80 μm. 0 μm, about 20 to 75 μm, about 22 to 100 μm, about 22 to 90 μm, about 22 to 80 μm, about 22 to 75 μm, about 25 to 100 μm, about 25 to 90 μm, about 25 to 80 μm, about 25 to 75 μm, about 40 to 100 μm, about 40 to 90 μm, about 40 to 80 μm, about 40 to 75 μm, about 50 to 100 μm, about 50 to 90 μm, about 50 to 80 μm, and about 50 to 75 μm.

[0062] The base material layer 1 contains a colorant, which allows the electrical storage device packaging material to be colored. Known colorants such as pigments and dyes can be used as the colorant. Only one type of colorant may be used, or two or more types may be mixed together.

[0063] The type of pigment is not particularly limited as long as it does not impair the function as a substrate of the substrate layer 1. 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.

[0064] Among colorants, carbon black is preferred for making the exterior material for an electricity storage device black, and mica is preferred from the viewpoint of dissipating heat generated from the electricity storage device.

[0065] The average particle size of the pigment is not particularly limited and may be, for example, about 0.03 to 5 μm, and preferably about 0.05 to 2 μm. The average particle size of the pigment is the median size measured with a laser diffraction / scattering particle size distribution analyzer.

[0066] The content of the colorant in the base layer 1 is not particularly limited as long as the packaging material for an electricity storage device is colored, and may be, for example, about 5 to 60 mass %, and preferably about 10 to 40 mass %.

[0067] When differential scanning calorimetry (DSC) measurement of the substrate layer 1 is performed under the following conditions, and the peak area (heat of crystallization (J / g)) during the temperature drop process is calculated, the peak area is preferably 30.0 J / g or less, more preferably 29.0 J / g or less. The lower limit is, for example, 20.0 J / g or more, more preferably 23.0 J / g or more. Preferred ranges include approximately 20.0 to 30.0 J / g, approximately 20.0 to 29.0 J / g, approximately 23.0 to 30.0 J / g, and approximately 23.0 to 29.0 J / g. When the peak area (heat of crystallization) during the temperature drop process in DSC measurement of the substrate layer is 30.0 J / g or less, the substrate layer has low crystallinity and is less likely to crack, which can be said to contribute favorably to the high formability of the electrical storage device packaging material. Note that, as a method for extracting the substrate layer from the electrical storage device packaging material, the barrier layer can be dissolved in dilute hydrochloric acid, the substrate layer can be extracted, washed with water, and dried, and this can be used for measurement.

[0068] (DSC Measurement Conditions) Differential Scanning Calorimeter The heat of transition (heat of crystallization) is determined by cooling using the following procedure. In accordance with JIS K7122:2024, the sample is held at 0°C for 1 minute, then heated to 280°C at a heating rate of 10°C / min and held there for 5 minutes. The sample is then cooled to 0°C at a cooling rate of 10°C / min, and a DSC curve is plotted. The flow rate of nitrogen gas during this process is 50 ml / min.

[0069] [Adhesive Layer 2] In the packaging material for an electricity storage device according to 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.

[0070] 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 volatilization 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.

[0071] 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 with two or more. 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 possessed by the adhesive components.

[0072] Examples of polyurethane adhesives include polyurethane adhesives containing a first part containing a polyol compound and a second part containing an isocyanate compound. Two-component curing polyurethane adhesives are preferred, with a polyol such as polyester polyol, polyether polyol, or acrylic polyol as the first part and an aromatic or aliphatic polyisocyanate as the second part. Examples of polyurethane adhesives include polyurethane adhesives containing a polyurethane compound obtained by reacting a polyol compound with an isocyanate compound in advance, and an isocyanate compound. Examples of polyurethane adhesives include polyurethane adhesives containing a polyurethane compound obtained by reacting a polyol compound with an isocyanate compound in advance, and a polyol compound. Examples of polyurethane adhesives include polyurethane adhesives obtained by reacting a polyurethane compound obtained by reacting a polyol compound with an isocyanate compound in advance with moisture, such as in the air, and then curing the polyurethane compound. Polyester polyols having hydroxyl groups on the side chains in addition to terminal hydroxyl groups in the repeating unit are preferably used as the polyol compound. Examples of the second part 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). Also included are polyfunctional isocyanate-modified compounds of one or more of these diisocyanates. Multimers (e.g., trimers) can also be used as polyisocyanate compounds. Examples of such multimers include adducts, biurets, and nurates. Forming the adhesive layer 2 using 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.

[0073] 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, etc. By including a colorant in the adhesive layer 2, the electrical storage device packaging material can be colored. Known colorants such as pigments and dyes can be used as colorants. Furthermore, only one type of colorant may be used, or two or more types may be mixed together.

[0074] 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.

[0075] 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.

[0076] The average particle size of the pigment is not particularly limited and may be, for example, about 0.03 to 5 μm, and preferably about 0.05 to 2 μm. The average particle size of the pigment is the median size measured with a laser diffraction / scattering particle size distribution analyzer.

[0077] The content of the colorant 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 %.

[0078] The thickness of the adhesive layer 2 is not particularly limited as long as it can bond the base material layer 1 and the barrier layer 3, but is, for example, about 1 μm or more, about 2 μm or more, or about 4 μm or more. The thickness of the adhesive layer 2 is, for example, about 10 μm or less, about 7 μm or more, and about 5 μm or less. Preferred ranges for the thickness of the adhesive layer 2 include about 1 to 10 μm, about 1 to 7 μm, about 1 to 5 μm, about 2 to 10 μm, about 2 to 7 μm, about 2 to 5 μm, about 4 to 10 μm, about 4 to 7 μm, and about 4 to 5 μm. From the viewpoint of imparting high moldability to the exterior material 10 for an electricity storage device, the thickness is preferably, for example, about 4 μm or more, about 10 μm or less, or about 7 μm or more, and about 5 μm or less, and preferred ranges include about 4 to 10 μm, about 4 to 7 μm, and about 4 to 5 μm.

[0079] [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.

[0080] 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. Only one type of colorant may be used, or two or more types may be mixed together.

[0081] Specific examples of the colorant contained in the colored layer include the same as those exemplified in the section [Adhesive layer 2].

[0082] [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.

[0083] 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 include 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.

[0084] In the barrier layer 3, the layer made of the aforementioned metal material may contain recycled metal material. Examples of recycled metal material include recycled aluminum alloy, stainless steel, titanium steel, and steel plate. These recycled materials can be obtained by known methods. Recycled aluminum alloy material can be obtained, for example, by the manufacturing method described in International Publication No. 2022 / 092231. The barrier layer 3 may be made of recycled material alone, or may be made of a mixture of recycled and virgin material. Note that recycled metal material refers to metal material that has been made reusable by collecting, isolating, and refining various products used in the market or waste from manufacturing processes. Furthermore, virgin metal material refers to new metal material refined from natural metal resources (raw materials) and is not recycled material.

[0085] 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 having an iron content of 0.1% by mass or more, an electrical storage device packaging material with better formability can be obtained. By having an iron content of 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.

[0086] Examples of the 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.

[0087] Specific examples of austenitic stainless steels that form the stainless steel foil include SUS304, SUS301, and SUS316L, with SUS304 being particularly preferred.

[0088] 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 may be, for example, about 9 to 200 μm. The thickness of the barrier layer 3 is preferably about 10 μm or more, about 20 μm or more, about 25 μm or more, more preferably about 50 μm or more, about 52 μm or more, about 60 μm or more, about 70 μm or more, and even more preferably about 80 μm or more. The thickness of the barrier layer 3 is preferably about 100 μm or less, about 95 μm or less, about 90 μm or less, about 80 μm or less, about 50 μm or less, about 40 μm or less, or about 35 μm or less. Furthermore, preferred ranges for the thickness of the barrier layer 3 are about 10 to 100 μm, about 10 to 95 μm, about 10 to 90 μm, about 10 to 80 μm, about 10 to 50 μm, about 10 to 40 μm, about 10 to 35 μm, about 20 to 100 μm, about 20 to 95 μm, about 20 to 90 μm, about 20 to 80 μm, about 20 to 50 μm, about 20 to 40 μm, about 20 to 35 μm, about 25 to 100 μm, about 25 to 95 μm, about 25 to 90 μm, about 25 to 80 μm, about 25 to 50 μm, about 25 Examples of thickness ranges include about 40 μm to about 40 μm, about 25 to 35 μm, about 50 to 100 μm, about 50 to 95 μm, about 50 to 90 μm, about 50 to 80 μm, about 52 to 100 μm, about 52 to 95 μm, about 52 to 90 μm, about 52 to 80 μm, about 60 to 100 μm, about 60 to 95 μm, about 60 to 90 μm, about 60 to 80 μm, about 70 to 100 μm, about 70 to 95 μm, about 70 to 90 μm, about 70 to 80 μm, about 80 to 100 μm, about 80 to 95 μm, and about 80 to 90 μm. When the barrier layer 3 is made of aluminum alloy foil, the above-mentioned ranges are particularly preferred.From the viewpoint of imparting high formability and high rigidity to the exterior packaging material 10 for an electricity storage device, the thickness of the barrier layer 3 is preferably about 50 μm or more, about 52 μm or more, more preferably about 60 μm or more, even more preferably about 70 μm or more, and still more preferably about 80 μm or more, and is preferably about 100 μm or less, more preferably about 95 μm or less, even more preferably about 90 μm or less, and still more preferably about 80 μm or less. About 0 to 100 μm, about 50 to 95 μm, about 50 to 90 μm, about 50 to 80 μm, about 52 to 100 μm, about 52 to 95 μm, about 52 to 90 μm, about 52 to 80 μm, about 60 to 100 μm, about 60 to 95 μm, about 60 to 90 μm, about 60 to 80 μm, about 70 to 100 μm, about 70 to 95 μm, about 70 to 90 μm, about 70 to 80 μm, about 80 to 100 μm, about 80 to 95 μm, about 80 to 90 μm. By providing the exterior material 10 for an electricity storage device with high formability, deep drawing is facilitated, which can contribute to increasing the capacity of the electricity storage device. Furthermore, although increasing the capacity of an electricity storage device increases the weight of the electricity storage device, increasing the rigidity of the exterior material 10 for an electricity storage device contributes to high sealing performance of the electricity storage device. In particular, when the barrier layer 3 is made of stainless steel foil, the thickness of the stainless steel foil is preferably about 60 μm or less, more preferably about 50 μm or less, even more preferably about 40 μm or less, even more preferably about 30 μm or less, and particularly preferably about 25 μm or less. The thickness of the stainless steel foil is preferably about 10 μm or more, more preferably about 15 μm or more. 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.

[0089] 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 that is provided with corrosion resistance (e.g., acid resistance, alkali resistance, etc.) by performing, for example, a hydrothermal conversion treatment such as boehmite treatment, a chemical conversion treatment, an anodizing treatment, a plating treatment of nickel or chromium, or a corrosion prevention treatment by applying a coating agent on the surface of the barrier layer. Specifically, the corrosion-resistant coating refers to a coating that improves the acid resistance of the barrier layer (acid-resistant coating), a coating that improves the alkali resistance of the barrier layer (alkali-resistant coating), etc. The treatment for forming the corrosion-resistant coating may be one type or a combination of two or more types. Furthermore, not only one layer but also multiple layers can be formed. Furthermore, among these treatments, the hydrothermal conversion treatment and the anodizing treatment are treatments that dissolve the metal foil surface with a treatment agent to form a metal compound with excellent corrosion resistance. These treatments may be included in the definition of chemical conversion treatment. In addition, when the barrier layer 3 is provided with a corrosion-resistant coating, the barrier layer 3 includes the corrosion-resistant coating.

[0090] The corrosion-resistant coating prevents delamination between the barrier layer (e.g., aluminum alloy foil) and the substrate layer during molding of the electrical storage device packaging material, prevents dissolution and corrosion of the barrier layer surface due to hydrogen fluoride produced by a 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 molding.

[0091] Various corrosion-resistant coatings formed by chemical conversion treatments are known, including mainly 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 containing, as its main component, a metal phosphate such as chromium (Cr) phosphate, titanium (Ti) phosphate, zirconium (Zr) phosphate, or zinc (Zn) phosphate, or a mixture of these metal salts, or a treatment solution containing, as its main component, a nonmetallic phosphate and a mixture of these nonmetallic salts, or a mixture of these with a synthetic resin, by 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. Examples of the resin component used here include polymers such as phenolic resins and acrylic resins, and chromate treatment using an aminated phenol polymer having repeating units represented by the following general formulas (1) to (4). The aminated phenol polymer may contain one type of repeating unit represented by the following general formulas (1) to (4) alone, or two or more types of repeating units may be contained in any combination.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.

[0092]

[0093]

[0094]

[0095]

[0096] 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 2 Examples 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 2Examples 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 formulae (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 formulae (1) to (4) is preferably about 500 to 1,000,000, for example, 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 form a functional group (-CHNR 1 R 2 The aminated phenol polymers may be used singly or in combination of two or more.

[0097] 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 contains 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. Examples of liquid dispersion media for the rare earth element oxide sol include 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 consisting 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 include 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, or 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.

[0098] An example of a corrosion-resistant coating is one formed by applying a solution in which fine particles of a metal oxide such as aluminum oxide, titanium oxide, cerium oxide, or tin oxide, or barium sulfate are dispersed in phosphoric acid to the surface of a barrier layer and then baking the coating at 150°C or higher.

[0099] 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.

[0100] The composition of the corrosion-resistant film can be analyzed by, for example, time-of-flight secondary ion mass spectrometry.

[0101] 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 a coating-type chromate treatment, the amount of the corrosion-resistant film formed on the surface of the barrier layer 3 is 2 It is desirable that the chromate compound is contained in an amount, calculated as chromium, of about 0.5 to 50 mg, preferably about 1.0 to 40 mg, the phosphorus compound in an amount, calculated as phosphorus, of about 0.5 to 50 mg, preferably about 1.0 to 40 mg, and the aminated phenol polymer in an amount, calculated as phosphorus, of about 1.0 to 200 mg, preferably about 5.0 to 150 mg, per 1000 ml of the aqueous solution.

[0102] 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, for example, the thickness of the corrosion-resistant coating consisting of secondary ions of Ce, P, and O (e.g., Ce2PO4 + , CePO4 - or at least one of ions of Cr, P, and O (e.g., CrPO2 + , CrPO4 - Peaks derived from at least one of the above are detected.

[0103] 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 the like, and then heating the barrier layer to a temperature of about 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 the like. By performing such a degreasing treatment, the chemical conversion treatment of the surface of the barrier layer can be carried out more efficiently. Furthermore, by using an acid degreasing agent prepared by dissolving a fluorine-containing compound in an inorganic acid for the degreasing treatment, it is possible to not only degrease the metal foil but also form a fluoride of the metal, which is in a passive state. In such cases, only the degreasing treatment may be carried out.

[0104] [Heat-fusible resin layer 4] In the exterior packaging material for an electricity storage device of the present disclosure, the heat-fusible 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-fusible resin layers being heat-fused together when the electricity storage device is assembled.

[0105] 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 Nearby and wave number 1780 cm -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 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.

[0106] The heat-sealable resin layer 4 preferably contains a resin containing a polyolefin skeleton as a main component, more preferably a polyolefin as a main component, and even more preferably polypropylene as a main component. Here, "main component" refers to a resin component whose content of the resin components contained in the heat-sealable resin layer 4 is, for example, 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, even more preferably 98% by mass or more, and even more preferably 99% by mass or more. For example, "the heat-sealable resin layer 4 contains polypropylene as a main component" means that the polypropylene content of the resin components contained in the heat-sealable resin layer 4 is, for example, 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, even more preferably 98% by mass or more, and even more preferably 99% by mass or more.

[0107] 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.

[0108] The polyolefin may also be a cyclic polyolefin. Cyclic polyolefins are copolymers of olefins and cyclic monomers, and examples of olefins constituting the cyclic polyolefins include ethylene, propylene, 4-methyl-1-pentene, styrene, butadiene, and isoprene. Examples of cyclic monomers constituting the cyclic polyolefins include cyclic alkenes such as norbornene; and cyclic dienes such as cyclopentadiene, dicyclopentadiene, cyclohexadiene, and norbornadiene. Among these, cyclic alkenes are preferred, and norbornene is more preferred.

[0109] The polyolefin may also be an acid-modified polyolefin. An acid-modified polyolefin is a polymer modified by block polymerization or graft polymerization of a polyolefin with an acid component. Examples of the acid-modified polyolefin include the above-mentioned polyolefins, copolymers of the above-mentioned polyolefins with polar molecules such as acrylic acid or methacrylic acid, and polymers such as crosslinked polyolefins. Examples of the acid component 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.

[0110] 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.

[0111] 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.

[0112] The thermally adhesive resin layer 4 may be formed of one type of resin alone or 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.

[0113] When the thermally adhesive resin layer 4 is laminated with the barrier layer 3, the adhesive layer 5, or the like to produce the exterior packaging material 10 for an electricity storage device of the present disclosure, a pre-formed resin film may be used as the thermally adhesive resin layer 4. Alternatively, the thermally adhesive resin that forms the thermally adhesive resin layer 4 may be formed into a film on the surface of the barrier layer 3, the adhesive layer 5, or the like by extrusion molding, coating, or the like, to form the thermally adhesive resin layer 4 from a resin film.

[0114] Furthermore, the thermally adhesive resin layer 4 may contain a lubricant or the like as necessary. When the thermally adhesive resin layer 4 contains a lubricant, the formability of the electrical storage device packaging material can be improved. The lubricant is not particularly limited, and known lubricants can be used.

[0115] The lubricant is not particularly limited, but preferably an amide-based lubricant is used. Specific examples of the lubricant include those exemplified for the base layer 1. The lubricant may be used alone or in combination of two or more types, and a combination of two or more types is preferred.

[0116] 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 at least one of the surface and the interior of the heat-sealable resin layer 4. 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, N,N'-distearyl sebacic acid amide, etc. Specific examples of unsaturated fatty acid bisamides include ethylene bisoleic acid amide, ethylene biserucic acid amide, hexamethylene bisoleic acid amide, N,N'-dioleyl adipamide, N,N'-dioleyl sebacic acid amide, etc. Specific examples of fatty acid ester amides include stearamidoethyl stearate, etc. Specific examples of aromatic bisamides include m-xylylene bisstearic acid amide, m-xylylene bishydroxystearic acid amide, and N,N'-distearylisophthalic acid amide.The lubricant may be used alone or in combination of two or more kinds, and it is preferable to use a combination of two or more kinds.

[0117] 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 exterior material for an electrical storage device, the amount of the lubricant is preferably about 1 mg / m 2 or more, more preferably about 3 mg / m 2 or more, more preferably about 5 mg / m 2 or more, more preferably about 10 mg / m 2 or more, more preferably about 15 mg / m 2 or more, and preferably about 50 mg / m 2 or less, more preferably about 40 mg / m 2 The preferred range is 1 to 50 mg / m 2 Degree, 1-40mg / m 2 Degree, 3-50mg / m 2 Degree, 3-40mg / m 2 degree, 5-50mg / m 2 degree, 5-40mg / m 2 degree, 10-50mg / m 2 degree, 10-40mg / m 2 degree, 15-50mg / m 2 degree, 15-40mg / m 2 The degree of

[0118] When a lubricant is present inside the heat-sealable resin layer 4, the amount thereof is not particularly limited, but from the viewpoint of improving the formability of the packaging material for an electrical storage device, it is preferably about 100 ppm or more, more preferably about 300 ppm or more, and even more preferably about 500 ppm or more, and is preferably about 3000 ppm or less, more preferably about 2000 ppm or less, and preferred ranges include about 100 to 3000 ppm, about 100 to 2000 ppm, about 300 to 3000 ppm, about 300 to 2000 ppm, about 500 to 3000 ppm, and about 500 to 2000 ppm. When two or more types of lubricant are present inside the heat-sealable resin layer 4, the above amount of lubricant is the total amount of lubricant. Furthermore, when two or more types of lubricants are present inside the heat-sealable resin layer 4, the amount of the first type of lubricant present is not particularly limited, but from the viewpoint of improving the formability of the exterior material for an electrical storage device, it is preferably about 100 ppm or more, more preferably about 300 ppm or more, even more preferably about 500 ppm or more, and is preferably about 3000 ppm or less, more preferably about 2000 ppm or less, and preferred ranges include about 100 to 3000 ppm, about 100 to 2000 ppm, about 300 to 3000 ppm, about 300 to 2000 ppm, about 500 to 3000 ppm, and about 500 to 2000 ppm. The amount of the second type of lubricant present is not particularly limited, but from the viewpoint of improving the formability of the exterior material for an electricity storage device, it is preferably about 50 ppm or more, more preferably about 100 ppm or more, and even more preferably about 200 ppm or more, and is preferably about 1500 ppm or less, more preferably about 1000 ppm or less, and preferred ranges include about 50 to 1500 ppm, about 50 to 1000 ppm, about 100 to 1500 ppm, about 100 to 1000 ppm, about 200 to 1500 ppm, and about 200 to 1000 ppm.

[0119] 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.

[0120] 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 to each other 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. Note that, 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, 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, more preferably about 35 to 85 μm.

[0121] [Adhesive Layer 5] In the packaging material for an electricity storage device according to the present disclosure, the adhesive layer 5 is a layer that is provided as needed between the barrier layer 3 (or the corrosion-resistant coating) and the heat-sealable resin layer 4 in order to firmly bond them together.

[0122] The adhesive layer 5 is formed of a resin that can bond the barrier layer 3 and the heat-sealable resin layer 4. As the resin used to form the adhesive layer 5, for example, the same adhesive as exemplified for the adhesive layer 2 can be used.

[0123] Furthermore, 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, and examples thereof include the polyolefins, acid-modified polyolefins, cyclic polyolefins, and acid-modified cyclic polyolefins exemplified for the heat-sealable resin layer 4 described above. On the other hand, 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 viewpoint 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.

[0124] When the resin used to form the adhesive layer 5 contains a polyolefin skeleton, the adhesive layer 5 preferably contains a resin containing a polyolefin skeleton as a main component, more preferably an acid-modified polyolefin as a main component, and even more preferably an acid-modified polypropylene as a main component. Here, "main component" means that the content of the resin component contained in the adhesive layer 5 is, for example, 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, even more preferably 98% by mass or more, and even more preferably 99% by mass or more. For example, when the adhesive layer 5 contains acid-modified polypropylene as a main component, it means that the content of acid-modified polypropylene among the resin components contained in the adhesive layer 5 is, for example, 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, even more preferably 98% by mass or more, and even more preferably 99% by mass or more.

[0125] 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 wave number of 1760 cm -1 Nearby and wave number 1780 cm -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.

[0126] Furthermore, from the viewpoint of ensuring durability such as heat resistance and resistance to contents of the electrical storage device packaging material, 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 described above.

[0127] 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. 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 is particularly preferred. 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 curing agents such as compounds having an isocyanate group, compounds having an oxazoline group, or epoxy resins remain in the adhesive layer 5, the presence of the unreacted materials 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.

[0128] 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 C—O—C 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 C—O—C 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.

[0129] The compound having an isocyanate group is not particularly limited, but from the viewpoint of effectively increasing the adhesion between the barrier layer 3 and the adhesive layer 5, a polyfunctional isocyanate compound is preferably used. The polyfunctional isocyanate compound is not particularly limited as long as it is a compound having two or more isocyanate groups. Specific examples of polyfunctional isocyanate curing agents include pentane diisocyanate (PDI), isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), polymers or nurates thereof, mixtures of these, and copolymers with other polymers. Other examples include adducts, biurets, and isocyanurates.

[0130] 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 makes it possible to effectively improve the adhesion between the barrier layer 3 and the adhesive layer 5.

[0131] 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.

[0132] 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 makes it possible to effectively improve the adhesion between the barrier layer 3 and the adhesive layer 5.

[0133] Examples of compounds having epoxy groups include epoxy resins. The epoxy resin is not particularly limited as long as it is a resin capable of forming a crosslinked structure by the epoxy groups present in the molecule, and known epoxy resins can be used. The weight-average molecular weight of the epoxy resin is preferably about 50 to 2,000, more preferably about 100 to 1,000, and even more preferably about 200 to 800. In the present disclosure, the weight-average molecular weight of the epoxy resin is a value measured by gel permeation chromatography (GPC) under conditions using polystyrene as a standard sample.

[0134] 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. The epoxy resins may be used alone or in combination of two or more.

[0135] 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 makes it possible to effectively improve the adhesion between the barrier layer 3 and the adhesive layer 5.

[0136] 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.

[0137] The proportion of polyurethane 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 makes it possible to effectively improve the adhesion between the barrier layer 3 and the adhesive layer 5 in an atmosphere containing a component that induces corrosion of the barrier layer, such as an electrolyte solution.

[0138] 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.

[0139] The adhesive layer 5 may contain a modifier having a carbodiimide group.

[0140] When the adhesive layer 5 is laminated with the barrier layer 3, the heat-sealable resin layer 4, or the like to produce the packaging material for an electricity storage device 10 of the present disclosure, a pre-formed resin film may be used as the adhesive layer 5. Alternatively, the heat-sealable resin that forms the adhesive layer 5 may be formed into a film on the surface of the barrier layer 3, the heat-sealable resin layer 4, or the like by extrusion molding, coating, or the like, to form the adhesive layer 5 from a resin film.

[0141] 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 of the adhesive layer 5 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.

[0142] [Surface Coating Layer 6] The packaging material for an electricity storage device according to the present disclosure may, if necessary, have a surface coating layer 6 on the substrate layer 1 (the side of the substrate layer 1 opposite to the barrier layer 3) for the purpose of improving at least one of design, electrolyte resistance, scratch resistance, formability, etc. The surface coating layer 6 is a layer located on the outermost layer side of the packaging material for an electricity storage device when an electricity storage device is assembled using the packaging material for an electricity storage device.

[0143] The surface coating layer 6 may be made of, for example, a resin such as polyvinylidene chloride, polyester, polyamide, epoxy resin, acrylic resin, fluororesin, polyurethane, silicone resin, or phenolic resin, or a modified version of these resins. It may also be a copolymer of these resins or a modified version of the copolymer. It may also be a mixture of these resins. The resin is preferably a curable resin. That is, the surface coating layer 6 is preferably made of a cured product of a resin composition containing a curable resin.

[0144] When the resin forming the surface coating layer 6 is a curable resin, the resin may be either a one-component curable resin or a two-component curable resin, but is preferably a two-component curable resin. Examples of two-component curable resins include two-component curable polyurethane, two-component curable polyester, and two-component curable epoxy resin. Among these, two-component curable polyurethane is preferred.

[0145] Examples of two-component curing polyurethanes include polyurethanes containing a first component containing a polyol compound and a second component containing an isocyanate compound. Preferred examples of two-component curing polyurethanes include those containing a polyol, such as polyester polyol, polyether polyol, or acrylic polyol, as the first component and an aromatic or aliphatic polyisocyanate as the second component. Examples of polyurethanes include polyurethanes containing an isocyanate compound and a polyurethane compound obtained by reacting a polyol compound with an isocyanate compound in advance. Examples of polyurethanes include polyurethanes containing a polyol compound and a polyurethane compound obtained by reacting a polyol compound with an isocyanate compound in advance. Examples of polyurethanes include polyurethanes obtained by reacting a polyol compound with an isocyanate compound in advance and then curing the polyurethane compound with moisture, such as in the air. Polyol compounds preferably include polyester polyols having hydroxyl groups on the side chains in addition to the terminal hydroxyl groups of the repeating units. Examples of second components 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). Also included are polyfunctional isocyanate-modified compounds of 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. It should be noted that an aliphatic isocyanate compound refers to an isocyanate that has an aliphatic group but does not have an aromatic ring, an alicyclic isocyanate compound refers to an isocyanate that has an alicyclic hydrocarbon group, and an aromatic isocyanate compound refers to an isocyanate that has an aromatic ring.The surface coating layer 6 is formed from polyurethane, which provides the electrical storage device packaging material with excellent electrolyte resistance.

[0146] The surface coating layer 6 may contain additives such as lubricants, flame retardants, antiblocking agents, antioxidants, light stabilizers, tackifiers, antistatic agents, and pigments, as necessary, in at least one of the surface and interior of the surface coating layer 6, depending on the functionality to be provided to the surface of the surface coating layer 6. Examples of additives include fine particles with an average particle size of approximately 0.5 nm to 5 μm. The average particle size of the additive is the median size measured with a laser diffraction / scattering particle size distribution analyzer.

[0147] The additive may be either inorganic or organic. The shape of the additive is not particularly limited, and examples thereof include spherical, fibrous, plate-like, amorphous, and scaly shapes.

[0148] Specific examples of additives include talc, silica, graphite, kaolin, montmorillonite, mica, hydrotalcite, silica gel, zeolite, aluminum hydroxide, magnesium hydroxide, zinc oxide, magnesium oxide, aluminum oxide, neodymium oxide, antimony oxide, titanium oxide, cerium oxide, calcium sulfate, barium sulfate, calcium carbonate, calcium silicate, lithium carbonate, calcium benzoate, calcium oxalate, magnesium stearate, alumina, carbon black, carbon nanotubes, high-melting-point nylon, acrylate resin, crosslinked acrylic, crosslinked styrene, crosslinked polyethylene, benzoguanamine, gold, aluminum, copper, and nickel. The additives may be used alone or in combination of two or more. Among these additives, silica, barium sulfate, and titanium oxide are preferred from the viewpoints of dispersion stability and cost. The additives may also be subjected to various surface treatments, such as insulation treatment and high-dispersibility treatment.

[0149] The method for forming the surface coating layer 6 is not particularly limited, and examples thereof include a method of applying a resin to form the surface coating layer 6. When an additive is blended into the surface coating layer 6, a resin mixed with the additive may be applied.

[0150] 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 at least one of the surface and the interior of the surface coating layer 6. 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, N,N'-distearyl sebacic acid amide, etc. Specific examples of unsaturated fatty acid bisamides include ethylene bisoleic acid amide, ethylene biserucic acid amide, hexamethylene bisoleic acid amide, N,N'-dioleyl adipamide, N,N'-dioleyl sebacic acid amide, etc. Specific examples of fatty acid ester amides include stearamidoethyl stearate, etc. Specific examples of aromatic bisamides include m-xylylene bisstearic acid amide, m-xylylene bishydroxystearic acid amide, and N,N'-distearylisophthalic acid amide.The lubricant may be used alone or in combination of two or more kinds, and it is preferable to use a combination of two or more kinds.

[0151] When a lubricant is present on the surface of the surface coating layer 6, the amount of the lubricant is not particularly limited, but may be, for example, about 3 mg / m 2 or more, preferably about 4 mg / m 2 Above, about 5mg / m 2 The amount of lubricant present on the surface of the surface coating layer 6 is, for example, about 15 mg / m 2 or less, preferably about 14 mg / m 2 Below, about 10mg / m 2 The preferred range of the amount of lubricant present on the surface of the surface coating layer 6 is 3 to 15 mg / m 2 Degree, 3-14mg / m 2 Degree, 3-10mg / m 2 Degree, 4-15mg / m 2 Degree, 4-14mg / m 2 degree, 4-10mg / m 2 degree, 5-15mg / m 2 Degree, 5-14mg / m 2 degree, 5-10mg / m 2 The degree of

[0152] The lubricant present on the surface of the surface coating layer 6 may be a lubricant exuded from the resin that constitutes the surface coating layer 6, or a lubricant applied to the surface of the surface coating layer 6.

[0153] The surface coating layer 6 contains a colorant, which allows the electrical storage device exterior material to be colored. Known colorants such as pigments and dyes can be used as the colorant. Only one type of colorant may be used, or two or more types may be mixed together.

[0154] The type of pigment is not particularly limited, and 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. Examples of inorganic pigments include carbon black-based, titanium oxide-based, cadmium-based, lead-based, chromium oxide-based, and iron-based pigments. Other examples include finely powdered mica and fish scale foil.

[0155] Among colorants, carbon black is preferred for making the exterior material for an electricity storage device black, and mica is preferred from the viewpoint of dissipating heat generated from the electricity storage device.

[0156] The average particle size of the pigment is not particularly limited and may be, for example, about 0.03 to 5 μm, and preferably about 0.05 to 2 μm. The average particle size of the pigment is the median size measured with a laser diffraction / scattering particle size distribution analyzer.

[0157] The content of the colorant in the surface coating layer 6 is not particularly limited as long as the packaging material for an electricity storage device is colored, and may be, for example, about 5 to 60 mass %, and preferably about 10 to 40 mass %.

[0158] The thickness of the surface coating layer 6 is not particularly limited as long as it exhibits the above-mentioned functions as the surface coating layer 6, and may be, for example, about 0.5 to 10 μm, and preferably about 1 to 5 μm.

[0159] 3. Manufacturing Method of the Exterior Material for an Electrical Storage Device The manufacturing method of the exterior material for an electrical storage device is not particularly limited, as long as a laminate in which the layers included in the exterior material for an electrical storage device of the present disclosure are laminated can be obtained, and an example of such a method includes a step of laminating at least the base material layer 1, the barrier layer 3, and the heat-sealable resin layer 4 in this order.

[0160] An example of a manufacturing method for 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, the laminate A can be formed by a dry lamination method in which an adhesive used to form the adhesive layer 2 is applied to the base layer 1 or to the 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, and the barrier layer 3 or the base layer 1 is laminated thereon, and the adhesive layer 2 is cured.

[0161] 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, the adhesive layer 5 and the heat-sealable resin layer 4 may be laminated by, for example, (1) extrusion lamination, (2) thermal lamination, (3) sandwich lamination, or (4) dry lamination. Examples of the (1) extrusion lamination method include a method of laminating the adhesive layer 5 and the heat-sealable resin layer 4 on the barrier layer 3 of the laminate A by extrusion (co-extrusion lamination, tandem lamination), etc. Examples of the (2) thermal lamination method include a method of separately forming a laminate in which an adhesive layer 5 and a heat-fusible resin layer 4 are laminated, and laminating this on the barrier layer 3 of the laminate A, or a method of forming a laminate in which an adhesive layer 5 is laminated on the barrier layer 3 of the laminate A, and laminating this on the heat-fusible resin layer 4. Examples of the (3) sandwich lamination method include a method of pouring a molten adhesive layer 5 between the barrier layer 3 of the laminate A and the heat-fusible resin layer 4 that has been previously formed into a sheet, and bonding the laminate A and the heat-fusible resin layer 4 together via the adhesive layer 5. Examples of the (4) dry lamination method include a method of solution-coating an adhesive for forming the adhesive layer 5 on the barrier layer 3 of the laminate A, drying the adhesive, or baking the adhesive, and laminating the heat-fusible resin layer 4 that has been previously formed into a sheet on the adhesive layer 5.

[0162] When the surface coating layer 6 is provided, the surface coating layer 6 is laminated on the surface of the base layer 1 opposite to the barrier layer 3. The surface coating layer 6 can be formed, for example, by applying the above-mentioned resin for forming the surface coating layer 6 to the surface of the base layer 1. The order of the step of laminating the barrier layer 3 on the surface of the base layer 1 and the step of laminating the surface coating layer 6 on the surface of the base layer 1 is not particularly limited. For example, after the surface coating layer 6 is formed on the surface of the base layer 1, the barrier layer 3 may be formed on the surface of the base layer 1 opposite to the surface coating layer 6.

[0163] As described above, a laminate is formed which includes the optional surface coating layer 6 / substrate layer 1 / optional adhesive layer 2 / barrier layer 3 / optional adhesive layer 5 / thermally adhesive resin layer 4 in this order, and in order to strengthen the adhesion of the optional adhesive layer 2 and adhesive layer 5, the laminate may be further subjected to a heat treatment.

[0164] In the packaging material for an electricity storage device, each layer constituting the laminate may be subjected to a surface activation treatment such as corona treatment, blast treatment, oxidation treatment, ozone treatment, etc. as necessary to improve processability. For example, by subjecting the surface of the base layer 1 opposite to the barrier layer 3 to corona treatment, the printability of ink on the surface of the base layer 1 can be improved.

[0165] 4. Uses of the Electricity Storage Device Exterior Material The electricity storage device exterior material of the present disclosure is used in a package for hermetically housing electricity storage device elements such as a positive electrode, a negative electrode, and an electrolyte. 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 electricity storage device exterior material of the present disclosure. In other words, an electricity storage device can be formed by wrapping an electricity storage device element in the electricity storage device exterior material of the present disclosure.

[0166] Specifically, an electricity storage device using the electricity storage device packaging material is provided by covering an electricity storage device element including at least a positive electrode, a negative electrode, and an electrolyte with the electricity storage device packaging material of the present disclosure in a state in which metal terminals connected to each of the positive electrode and the negative electrode protrude outward, so that a flange portion (a region where the heat-sealable resin layers contact each other) can be formed around the periphery of the electricity storage device element, and then heat-sealing the heat-sealable resin layers of the flange portion to form a hermetic seal. Note that when an electricity storage device element is housed in a package formed from the electricity storage device packaging material of the present disclosure, the package is formed so that the heat-sealable resin portion of the electricity storage device packaging material of the present disclosure faces inside (the surface that contacts the electricity storage device element). A package may be formed by overlapping two electrical storage device exterior materials with the heat-sealable resin layers facing each other and heat-sealing the peripheral edges of the overlapped electrical storage device exterior materials, or by folding one electrical storage device exterior material over and overlapping the materials and heat-sealing the peripheral edges, as in the example shown in Fig. 6. When the materials are folded over and overlapped, the package may be formed by heat-sealing the sides other than the folded side to form a three-sided seal, as in the example shown in Fig. 6, or by folding over the material so as to form a flange and seal all four sides. Note that when the innermost and outermost layers of the electrical storage device exterior material are heat-sealable resin layers, the package may be formed by heat-sealing the heat-sealable resin layer of the innermost layer and the heat-sealable resin layer of the outermost layer.

[0167] The electricity storage device element may be sealed with a lid in addition to the electricity storage device exterior material. That is, the electricity storage device exterior material and the lid constitute an exterior (an exterior for an electricity storage device) that seals the electricity storage device element. For example, the electricity storage device element may be housed inside a cylindrically configured electricity storage device exterior material, and the opening may be closed with the lid. In another example, the electricity storage device element connected to the lid may be housed inside a cylindrically configured electricity storage device exterior material that has an opening, and the opening may be closed with the lid. The lid and the electricity storage device exterior material are preferably joined by any means. From the viewpoint of reducing dead space between the electricity storage device element and the electricity storage device exterior material to improve the volumetric energy density of the electricity storage device, the electricity storage device exterior material is preferably wrapped around the electricity storage device element and the lid.

[0168] The lid body can be formed, for example, from a resin molded product, a metal molded product, an exterior material for an electricity storage device, or a combination thereof. In this disclosure, when the lid body is referred to as a resin molded product, this does not include an embodiment in which the lid body is formed solely from a film defined by JIS K6900-1994 [Plastics - Terminology]. When the lid body is a metal molded product, the lid body also functions as a metal terminal, so the metal terminal can be omitted. The lid body may be formed from a resin material and a conductive material.

[0169] Furthermore, a recess for accommodating an electricity storage device element may be formed in the electrical storage device packaging material by deep drawing or bulging molding. As shown in the example in Fig. 6, a recess may be provided in one electrical storage device packaging material and no recess may be provided in the other electrical storage device packaging material, or a recess may also be provided in the other electrical storage device packaging material.

[0170] The exterior material for an electricity storage device of 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 of 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 of the present disclosure is applied is not particularly limited, and examples include lithium ion batteries, lithium ion polymer batteries, all-solid-state batteries, semi-solid batteries, quasi-solid batteries, polymer batteries, all-resin 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, the exterior material for an electricity storage device of the present disclosure is suitably applied to lithium ion batteries, lithium ion polymer batteries, and all-solid-state batteries.

[0171] 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.

[0172] <Production of exterior packaging material for electricity storage device> Example 1 As a substrate layer, a laminate was prepared in which a biaxially stretched polyethylene terephthalate (PET) film (thickness 25 μm) and an oriented nylon (ONy) film (thickness 25 μm) were bonded with an adhesive layer (thickness 3 μm, two-component curing urethane adhesive (formed of a polyol compound and an aromatic isocyanate compound)). Furthermore, as a barrier layer, aluminum foil (JIS H4160:1994 A8021H-O (thickness 80 μm)) was prepared. Both sides of the aluminum foil were subjected to a chemical conversion treatment. The chemical conversion treatment of the aluminum foil was carried out by using a treatment solution consisting of a phenolic resin, a chromium fluoride compound, and phosphoric acid, with a coating amount of chromium of 10 mg / m. 2 (dry mass) was applied to both sides of an aluminum foil by roll coating, and baked.

[0173] Next, a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate-based compound) was used to laminate the stretched nylon film side of the base material layer and the barrier layer by dry lamination, and then an aging treatment was carried out to produce a laminate of base material layer / adhesive layer (thickness: 3 μm) / barrier layer.

[0174] Next, maleic anhydride-modified polypropylene (PPa) as an adhesive layer (40 μm thick) and random polypropylene (PP) as a heat-sealable resin layer (40 μm thick) were co-extruded onto the barrier layer of each of the laminates obtained above, thereby laminating an adhesive layer / heat-sealable resin layer on the barrier layer. Through the above steps, an exterior packaging material for an electricity storage device was obtained, consisting of a laminate in which the base material layer, adhesive layer, barrier layer, adhesive layer, and heat-sealable resin layer were laminated in this order.

[0175] Example 2 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 1, except that aluminum foil (JIS H4160:1994 A8021H-O (thickness 60 μm)) was used as the barrier layer instead of aluminum foil (JIS H4160:1994 A8021H-O (thickness 80 μm)).

[0176] Example 3 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 1, except that the thickness of the adhesive layer bonding between the base layer and the barrier layer was changed from 3 μm to 5 μm.

[0177] Example 4 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 2, except that the thickness of the adhesive layer bonding between the base layer and the barrier layer was changed from 3 μm to 5 μm.

[0178] Example 5 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 1, except that a laminate in which a biaxially stretched polyethylene terephthalate (PET) film (thickness: 50 μm) and an oriented nylon (ONy) film (thickness: 25 μm) were bonded together with an adhesive layer (thickness: 3 μm, formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate-based compound)) was used as the base layer.

[0179] Example 6 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 2, except that a laminate in which a biaxially stretched polyethylene terephthalate (PET) film (thickness: 50 μm) and an oriented nylon (ONy) film (thickness: 25 μm) were bonded together with an adhesive layer (thickness: 3 μm, formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate-based compound)) was used as the base layer.

[0180] Example 7 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 1, except that a laminate in which a biaxially stretched polyethylene terephthalate (PET) film (thickness: 25 μm) and an oriented nylon (ONy) film (thickness: 15 μm) were bonded together with an adhesive layer (thickness: 3 μm, formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate-based compound)) was used as the base layer.

[0181] Example 8 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 2, except that a laminate in which a biaxially stretched polyethylene terephthalate (PET) film (thickness: 25 μm) and an oriented nylon (ONy) film (thickness: 15 μm) were bonded together with an adhesive layer (thickness: 3 μm, formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate-based compound)) was used as the base layer.

[0182] Example 9 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 1, except that a laminate in which a biaxially stretched polyethylene terephthalate (PET) film (thickness: 50 μm) and an oriented nylon (ONy) film (thickness: 15 μm) were bonded together with an adhesive layer (thickness: 3 μm, formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate-based compound)) was used as the base layer.

[0183] Example 10 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 2, except that a laminate in which a biaxially stretched polyethylene terephthalate (PET) film (thickness: 50 μm) and an oriented nylon (ONy) film (thickness: 15 μm) were bonded together with an adhesive layer (thickness: 3 μm, formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate-based compound)) was used as the base layer.

[0184] Example 11 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 1, except that a laminate in which a biaxially stretched polyethylene terephthalate (PET) film (thickness 75 μm) and an oriented nylon (ONy) film (thickness 15 μm) were bonded together with an adhesive layer (thickness 3 μm, formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate-based compound)) was used as the base layer.

[0185] Example 12 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 2, except that a laminate in which a biaxially stretched polyethylene terephthalate (PET) film (thickness 75 μm) and an oriented nylon (ONy) film (thickness 15 μm) were bonded together with an adhesive layer (thickness 3 μm, formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate-based compound)) was used as the base layer.

[0186] Example 13 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 1, except that a biaxially stretched polyethylene terephthalate (PET) film (thickness: 25 μm) was used as the base layer.

[0187] Example 14 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 2, except that a biaxially stretched polyethylene terephthalate (PET) film (thickness: 25 μm) was used as the base layer.

[0188] Example 15 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 1, except that a biaxially stretched polyethylene terephthalate (PET) film (thickness: 50 μm) was used as the base layer.

[0189] Example 16 A laminate having a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer laminated in this order was obtained in the same manner as in Example 2, except that a biaxially stretched polyethylene terephthalate (PET) film (thickness: 50 μm) was used as the base layer.

[0190] Example 17 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 1, except that a biaxially stretched polyethylene terephthalate (PET) film (thickness: 75 μm) was used as the base layer.

[0191] Example 18 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 2, except that a biaxially stretched polyethylene terephthalate (PET) film (thickness: 75 μm) was used as the base layer.

[0192] Example 19 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 1, except that a laminate in which a biaxially oriented polyethylene terephthalate (PET) film (thickness: 25 μm) and a biaxially oriented polyethylene terephthalate (PET) film (thickness: 12 μm) were bonded together with an adhesive layer (thickness: 3 μm, formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate-based compound)) was used as the base layer.

[0193] Example 20 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 2, except that a laminate in which a biaxially oriented polyethylene terephthalate (PET) film (thickness: 25 μm) and a biaxially oriented polyethylene terephthalate (PET) film (thickness: 12 μm) were bonded together with an adhesive layer (thickness: 3 μm, formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate-based compound)) was used as the base layer.

[0194] Example 21 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 1, except that a laminate in which a biaxially oriented polyethylene terephthalate (PET) film (thickness: 25 μm) and another biaxially oriented polyethylene terephthalate (PET) film (thickness: 25 μm) were bonded together with an adhesive layer (thickness: 3 μm, formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate-based compound)) was used as the base layer.

[0195] Example 22 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 2, except that a laminate in which a biaxially oriented polyethylene terephthalate (PET) film (thickness: 25 μm) and another biaxially oriented polyethylene terephthalate (PET) film (thickness: 25 μm) were bonded together with an adhesive layer (thickness: 3 μm, formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate-based compound)) was used as the base layer.

[0196] Example 23 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 1, except that a laminate in which a biaxially oriented polyethylene terephthalate (PET) film (thickness: 38 μm) and a biaxially oriented polyethylene terephthalate (PET) film (thickness: 25 μm) were bonded together with an adhesive layer (thickness: 3 μm, formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate-based compound)) was used as the base layer.

[0197] Example 24 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 2, except that a laminate in which a biaxially oriented polyethylene terephthalate (PET) film (thickness: 38 μm) and a biaxially oriented polyethylene terephthalate (PET) film (thickness: 25 μm) were bonded together with an adhesive layer (thickness: 3 μm, formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate-based compound)) was used as the base layer.

[0198] Example 25 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 1, except that a laminate in which a biaxially oriented polyethylene terephthalate (PET) film (thickness: 40 μm) and a biaxially oriented polyethylene terephthalate (PET) film (thickness: 25 μm) were bonded together with an adhesive layer (thickness: 3 μm, formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate-based compound)) was used as the base layer.

[0199] Example 26 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 2, except that a laminate in which a biaxially oriented polyethylene terephthalate (PET) film (thickness: 40 μm) and a biaxially oriented polyethylene terephthalate (PET) film (thickness: 25 μm) were bonded together with an adhesive layer (thickness: 3 μm, formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate-based compound)) was used as the base layer.

[0200] Example 27 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 1, except that a laminate in which a biaxially oriented polyethylene terephthalate (PET) film (thickness 12 μm) and another biaxially oriented polyethylene terephthalate (PET) film (thickness 12 μm) were bonded together with an adhesive layer (thickness 3 μm, formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate-based compound)) was used as the base layer.

[0201] Example 28 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 2, except that a laminate in which a biaxially oriented polyethylene terephthalate (PET) film (thickness 12 μm) and another biaxially oriented polyethylene terephthalate (PET) film (thickness 12 μm) were bonded together with an adhesive layer (thickness 3 μm, formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate-based compound)) was used as the base layer.

[0202] Comparative Example 1 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 1, except that a laminate in which a biaxially stretched polyethylene terephthalate (PET) film (thickness: 12 μm) and an oriented nylon (ONy) film (thickness: 25 μm) were bonded together with an adhesive layer (thickness: 3 μm, formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate-based compound)) was used as the base layer.

[0203] Comparative Example 2 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 2, except that a laminate in which a biaxially stretched polyethylene terephthalate (PET) film (thickness: 12 μm) and an oriented nylon (ONy) film (thickness: 25 μm) were bonded together with an adhesive layer (thickness: 3 μm, formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate-based compound)) was used as the base layer.

[0204] Comparative Example 3 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 1, except that a laminate in which a biaxially stretched polyethylene terephthalate (PET) film (thickness: 12 μm) and an oriented nylon (ONy) film (thickness: 15 μm) were bonded together with an adhesive layer (thickness: 3 μm, formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate-based compound)) was used as the base layer.

[0205] Comparative Example 4 A laminate in which a base layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order was obtained in the same manner as in Example 2, except that a laminate in which a biaxially stretched polyethylene terephthalate (PET) film (thickness: 12 μm) and an oriented nylon (ONy) film (thickness: 15 μm) were bonded together with an adhesive layer (thickness: 3 μm, formed of a two-component curing urethane adhesive (a polyol compound and an aromatic isocyanate-based compound)) was used as the base layer.

[0206] <Moisture Content of Electricity Storage Device Exterior Materials> The moisture content of the electricity storage device exterior materials obtained in each Example and Comparative Example after 24 hours of exposure to an environment at a temperature of 25°C and a relative humidity of 50% was measured using the following procedure. The results are shown in Table 1. To eliminate the influence of water penetration from the end faces, the samples (electricity storage device exterior materials) to be measured were 300 mm x 300 mm samples stored in an environment at a temperature of 25°C, a relative humidity of 1% or less, and a dew point of -20°C or less for 24 hours, and then stored in an environment at 25°C and a relative humidity of 50% for 24 hours, and a 100 mm x 100 mm sample was cut from the center and used. The moisture content was measured using a Karl Fischer moisture meter and evaporator placed in an environment at a temperature of 25°C, a humidity of 1% or less, and a dew point of -20°C or less, using the moisture evaporation-coulometric titration method. To minimize the influence of the measurement environment, the samples were wrapped in packaging that could block the outside air and brought into the measurement environment. They were then placed in the measurement device within 30 minutes of removal from the packaging. The measurement conditions were as follows: Component to be measured: water; titration cell type: two-liquid cell; detection electrode type: bipolar platinum electrode; diaphragm material: ceramic; endpoint detection method: AC polarization method using bipolar platinum detection electrode; endpoint determination method: drift stability determination; heating temperature: 180°C; cell purge time: 120 seconds; back-purge time: 180 seconds; stability determination value: 0.1 μg / min; endpoint potential: 200 mV. The measurement results were calculated as the ratio of water weight to sample weight (unit: ppm), and the average value of three measurements was reported, rounded to the nearest tenth. Commercially available anolyte and catholyte (ChemAqua Anolyte AGE and ChemAqua Catholyte CGE) were used as titration reagents.

[0207] <Seal Strength of Electricity Storage Device Exterior Materials When Heat-Sealed at 210°C> The seal strength of the electricity storage device exterior materials obtained by the same method as in the above <Moisture Content of Electricity Storage Device Exterior Materials> and exposed to an environment at 25°C and 50% relative humidity for 24 hours when heat-sealed at 210°C was measured using the following procedure. The results are shown in Table 1. In accordance with the provisions of JIS K7127:1999, the seal strength of the battery packaging material in a 25°C environment was measured as follows. Test pieces were prepared by cutting the battery packaging material into strips with a width of 15 mm in the TD direction. Specifically, as shown in FIG. 7 , each battery packaging material was first cut into a 60 mm (TD direction) × 200 mm (MD direction) size ( FIG. 7a ). Next, the battery packaging material was folded in half in the MD direction at the fold line P (midway in the MD direction) so that the heat-sealable resin layers faced each other ( FIG. 7b ). The heat-sealable resin layers were heat-sealed together approximately 10 mm inside the fold P in the MD direction under conditions of a seal width of 7 mm, a temperature of 210°C, a surface pressure of 1.0 MPa, and a duration of 3 seconds (Figure 7c). In Figure 7c, the hatched area S indicates the heat-sealed portion. Next, the specimen was cut in the MD direction (cut at the position of the two-dot chain line in Figure 7d) to a width of 15 mm in the TD direction to obtain a test piece (Figure 7e). Next, the test piece 13 was left at the measurement temperature for 2 minutes, and the heat-sealable resin layers at the heat-sealed portion were peeled at a rate of 300 mm / min using a tensile tester (Shimadzu Corporation, AG-Xplus (trade name)) in the measurement temperature environment (Figure 8). The maximum strength at the time of peeling was recorded as the seal strength (N / 15 mm). The chuck distance was 50 mm. The average value of three measurements was used. The results are shown in Table 1. In measuring the seal strength, the test piece 13 may peel (break) at the heat seal interface A shown in Figure 8, or may break at a location other than the heat seal interface A (for example, position B in Figure 8). When the test piece 13 breaks, the breaking strength is recorded in Table 1 as the seal strength.

[0208] <Presence or absence of bubbles outside the barrier layer of the electrical storage device packaging material during heat fusion> For the electrical storage device packaging materials that were the subject of measurement of the <Seal strength of the electrical storage device packaging material when heat fused at 210°C>, the base material layer and adhesive layer located outside the barrier layer were observed, and the presence or absence of bubbles was visually confirmed. The results are shown in Table 1.

[0209] <Molding Depth of Electricity Storage Device Exterior Material> The molding depth of the electricity storage device exterior material obtained in <Moisture Content of Electricity Storage Device Exterior Material> and exposed to an environment at a temperature of 25°C and a relative humidity of 50% for 24 hours was measured under the following conditions. The results are shown in Table 1. Each electricity storage device exterior material was cut into a square with a length (MD direction) of 200 mm and a width (TD direction) of 200 mm to prepare a test sample. The MD of the electricity storage device exterior material corresponds to the rolling direction (RD) of the aluminum alloy foil, and the TD of the electricity storage device exterior material corresponds to the TD of the aluminum alloy foil. This sample was placed in a 25°C environment in a rectangular molding die (female die, the surface of which had 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, Annex 1 (Reference), corner R2.0 mm, ridge R1.0 mm) with a bore of 100 mm (MD) x 110 mm (TD) and a corresponding molding die (male die, the surface of the ridgeline had a maximum height roughness (nominal value of Rz) of 1.6 μm as specified in Table 2 of the surface roughness standard for comparison in JIS B 0659-1:2002, Annex 1 (Reference), and the surface other than the ridgeline had a maximum height roughness (nominal value of Rz) of 1.6 μm as specified in Table 2 of the surface roughness standard for comparison in JIS B 0659-1:2002, Annex 1 (Reference), The maximum height roughness (nominal Rz value) specified in Table 2 of the comparative surface roughness standard piece is 3.2 μm. Using a corner R2.0 mm, ridge R1.0 mm), cold forming (single-stage drawing) was performed on 10 samples each, changing the forming depth in 0.5 mm increments from a forming depth of 0.5 mm at a pressing pressure (surface pressure) of 0.25 MPa. At this time, the test sample was placed on a female mold so that the heat-fusible resin layer side was located on the male mold side. The clearance between the male mold and the female mold was 0.3 mm. After cold forming, the sample was irradiated with a penlight in a dark room to check whether pinholes or cracks had occurred in the aluminum foil due to light transmission. The deepest molding depth at which no pinholes or cracks occurred in the aluminum foil in any of the 10 samples was defined as A mm, and the number of samples at the shallowest molding depth at which pinholes or the like occurred in the aluminum foil was defined as B. The value calculated by the following formula was rounded to two decimal places to determine the limit molding depth of the exterior material for an electricity storage device.Limit forming depth = A mm + (0.5 mm / 10 pieces) x (10 pieces - B pieces).

[0210]

[0211] As is clear from the results shown in Table 1, the electrical storage device packaging materials of Examples 1 to 28 contained a polyethylene terephthalate (PET) film having a thickness of 20 μm or more in the substrate layer. Despite being exposed to an environment of 25°C and 50% relative humidity for 24 hours outside the barrier layer, no foaming was observed during heat fusion. In particular, Examples 1 to 12 demonstrated the particularly excellent effect of not detecting foaming during heat fusion, despite the inclusion of a highly hygroscopic stretched nylon film (ONy) in the substrate layer. The electrical storage device packaging materials of Examples 1 to 12 also have the advantage of excellent formability due to the inclusion of a stretched nylon film in the substrate layer. Furthermore, in Examples 3 and 4, the adhesive layer between the substrate layer and the barrier layer was designed to be as thick as 5 μm. Even in this case, no foaming was observed during heat fusion and excellent formability was demonstrated. On the other hand, in the packaging materials for electricity storage devices of Comparative Examples 1 to 4, the base material layer contained a polyethylene terephthalate (PET) film, but the thickness was 12 μm, and foaming during heat fusion was confirmed outside the barrier layer.

[0212] <Peak area (heat of crystallization) during the temperature drop process in DSC measurement of the base layer> The base layer used in Example 1-4 (a biaxially oriented polyethylene terephthalate (PET) film (thickness 25 μm) and an oriented nylon (ONy) film (thickness 25 μm) bonded with an adhesive layer (3 μm thick, two-component curing urethane adhesive (formed from a polyol compound and an aromatic isocyanate compound) laminate) and the base layer used in Comparative Example 1-2 (a biaxially oriented polyethylene terephthalate (PET) film (thickness 12 μm) and an oriented nylon (ONy) film (thickness 25 μm) bonded with an adhesive layer (3 μm thick, two-component curing urethane adhesive (formed from a polyol compound and an aromatic isocyanate compound) laminate) were subjected to differential scanning calorimetry (DSC) measurement under the following conditions, and the peak area (heat of crystallization) during the temperature drop process was calculated. The results are shown in Table 2.

[0213] (DSC measurement conditions) Differential scanning calorimeter: DSC-60A Plus manufactured by Shimadzu Corporation The following procedure was used to determine the heat of transition (heat of crystallization) by cooling. In accordance with JIS K7122:2024, the sample was held at 0°C for 1 minute, then heated to 280°C at a heating rate of 10°C / min and held there for 5 minutes. The sample was then cooled to 0°C at a cooling rate of 10°C / min, and a DSC curve was plotted. The flow rate of nitrogen gas was 50 ml / min.

[0214]

[0215] The base material layer used in Examples 1-4 has a peak area (heat of crystallization) during the temperature drop process in DSC measurement of 30.0 J / g or less, and therefore has low crystallinity and is less likely to crack, which can be said to contribute to the high formability of the exterior material for an electricity storage device.

[0216] <Tensile Test of Sheathing Material for Electricity Storage Device> For the sheathing materials for electricity storage devices obtained in Example 1 and Comparative Examples 1 and 2, tensile tests were performed under the following conditions, and the tensile strength (N / 15 mm) at 25 mm displacement and the tensile strength (N / 15 mm) at 10 mm displacement in the MD direction, TD direction, and 45° direction (45° clockwise from the MD direction) were measured three times, and the average values ​​were rounded to the nearest tenth. Next, for the MD direction, TD direction, and 45° direction, the difference (| tensile strength at 25 mm displacement - tensile strength at 10 mm displacement |) between the tensile strength at 25 mm displacement (N / 15 mm) and the tensile strength at 10 mm displacement (N / 15 mm) was calculated. Furthermore, these differences were divided by the displacement difference of 15 mm (25 mm - 10 mm), and the respective values ​​were designated as MD direction: A, TD direction: B, and 45° direction: C. The values ​​in each direction were divided by the maximum value of A, B, and C (i.e., A / (maximum value of A, B, and C), B / (maximum value of A, B, and C) and C / (maximum value of A, B, and C)) as the denominator. The results are shown in Table 3.

[0217] (Tensile test conditions) Tensile tester: AG-Xplus (trade name), manufactured by Shimadzu Corporation Measurement environment: 25°C, in air Distance between chucks: 30 mm (initial distance between chucks was taken as the distance between gauge lines) Measurement speed: 50 mm / min Measurement sample width: 15 mm Measurement sample length: 100 mm Sample shape: rectangular

[0218]

[0219] The exterior packaging material for an electricity storage device in Example 1 has A / (the maximum value among A, B, and C), B / (the maximum value among A, B, and C), and C / (the maximum value among A, B, and C) in all directions, including MD, TD, and 45°, all falling within the range of 0.40 to 1.00, indicating that the material has a good balance with respect to tensile stress and exhibits high formability.

[0220] As described above, the present disclosure provides the following aspects of the invention. Item 1. An electrical storage device packaging material comprising a laminate including, in order from the outside, at least a substrate layer, a barrier layer, and a heat-sealable resin layer, the substrate layer including a polyester resin layer, and the polyester resin layer having a thickness of 20 μm or more. Item 2. The electrical storage device packaging material according to Item 1, wherein the electrical storage device packaging material has a moisture content of 2700 ppm or less when exposed to an environment at a temperature of 25°C and a relative humidity of 50% for 24 hours. Item 3. The electrical storage device packaging material according to Item 1 or 2, wherein the barrier layer has a thickness of 50 μm or more. Item 4. The electrical storage device packaging material according to any one of Items 1 to 3, wherein the substrate layer further includes a polyamide resin layer. Item 5. The electrical storage device packaging material according to Item 4, wherein the polyamide resin layer has a thickness of 20 μm or more. Item 6. Item 7. The packaging material for an electricity storage device according to any one of Items 1 to 3, further comprising an adhesive layer between the base material layer and the barrier layer. Item 8. The packaging material for an electricity storage device according to any one of Items 1 to 3, further comprising an adhesive layer between the barrier layer and the heat-sealable resin layer. Item 9. A method for producing a packaging material for an electricity storage device, comprising a step of obtaining a laminate in which, from outside, at least a base material layer, a barrier layer, and a heat-sealable resin layer are laminated, the base material layer including a polyester resin layer, and the polyester resin layer has a thickness of 20 μm or more. Item 10. 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 packaging material for an electricity storage device according to any one of Items 1 to 3.

[0221] REFERENCE SIGNS LIST 1 substrate layer 2 adhesive layer 3 barrier layer 4 heat-sealable resin layer 5 adhesive layer 6 surface coating layer 10 packaging material for electricity storage device 11 polyester resin layer 12 resin layer 12a adhesive layer

Claims

1. An exterior material for an electricity storage device, comprising a laminate having, in order from the outside, at least a base material layer, a barrier layer, and a heat-sealable resin layer, the base material layer includes a polyester resin layer, and the polyester resin layer has a thickness of 20 μm or more.

2. The electrical storage device packaging material according to claim 1, wherein the electrical storage device packaging material has a moisture content of 2700 ppm or less when exposed to an environment at a temperature of 25° C. and a relative humidity of 50% for 24 hours.

3. The exterior packaging material for an electricity storage device according to claim 1 or 2, wherein the barrier layer has a thickness of 50 μm or more.

4. The exterior packaging material for an electricity storage device according to claim 1 or 2, wherein the base layer further comprises a polyamide resin layer.

5. The exterior packaging material for an electricity storage device according to claim 4, wherein the polyamide resin layer has a thickness of 20 μm or more.

6. The exterior packaging material for an electricity storage device according to claim 1 or 2, further comprising an adhesive layer between the base layer and the barrier layer.

7. The exterior packaging material for an electricity storage device according to claim 6, wherein the adhesive layer has a thickness of 3 μm or more.

8. The packaging material for an electricity storage device according to claim 1 or 2, further comprising an adhesive layer between the barrier layer and the heat-sealable resin layer.

9. A method for producing an exterior material for an electricity storage device, comprising a step of obtaining a laminate in which, from the outside, at least a base material layer, a barrier layer, and a heat-sealable resin layer are laminated, the base material layer includes a polyester resin layer, and the polyester resin layer has a thickness of 20 μm or more.

10. An electricity storage device, in which an electricity storage device element having at least a positive electrode, a negative electrode, and an electrolyte is housed in a packaging body formed from the exterior material for an electricity storage device according to claim 1 or 2.