Adhesive film for metal terminals, method for manufacturing the same, metal terminals with the adhesive film for metal terminals, exterior materials for power storage devices, kits including the exterior materials for power storage devices and the adhesive film for metal terminals, and power storage devices and methods for manufacturing the same

Abstract

This adhesive film for metal terminals is interposed between: a metal terminal electrically connected to an electrode of a power storage device element; and an exterior material for power storage devices, which is for sealing the power storage device element. The adhesive film for metal terminals comprises a resin layer A that contains an insulating color material.

Description

Technical Field

[0001] The present disclosure relates to an adhesive film for metal terminals, a method for manufacturing the same, a metal terminal with an adhesive film for metal terminals, an exterior material for a power storage device, a kit including the exterior material for a power storage device and the adhesive film for metal terminals, and a power storage device and a method for manufacturing the same.

Background Art

[0002] Conventionally, various types of power storage devices have been developed. In all power storage devices, an exterior material for a power storage device is an essential member for sealing power storage device elements such as electrodes and electrolytes. Conventionally, a metal exterior material for a power storage device has been frequently used as the exterior material for a power storage device. However, in recent years, with the improvement in performance of electric vehicles, hybrid electric vehicles, personal computers, cameras, mobile phones, etc., power storage devices are required to have various shapes and to be thinner and lighter. However, the conventionally frequently used metal exterior material for a power storage device has drawbacks that it is difficult to follow the diversification of shapes and there is also a limit to weight reduction.

[0003] Therefore, in recent years, as an exterior material for a power storage device that can be easily processed into various shapes and can achieve thinning and weight reduction, a laminated sheet in which a base material layer / an adhesive layer / a barrier layer / a heat-sealable resin layer are sequentially laminated has been proposed. When using such a laminated film-shaped exterior material for a power storage device, with the heat-sealable resin layers located in the innermost layer of the exterior material for a power storage device facing each other, the peripheral portion of the exterior material for a power storage device is heat-sealed by heat sealing, whereby the power storage device elements are sealed by the exterior material for a power storage device.

[0004] A metal terminal protrudes from the heat-sealed portion of the exterior material for the power storage device, and the power storage device element sealed by the exterior material for the power storage device is electrically connected to the outside by the metal terminal electrically connected to the electrode of the power storage device element. That is, among the heat-sealed portions of the exterior material for the power storage device, the portion where the metal terminal exists is heat-sealed in a state where the metal terminal is sandwiched between the heat-fusible resin layers. Since the metal terminal and the heat-fusible resin layer are made of different materials from each other, the adhesion is likely to decrease at the interface between the metal terminal and the heat-fusible resin layer.

[0005] For this reason, an adhesive film may be disposed between the metal terminal and the heat-fusible resin layer for the purpose of enhancing their adhesion. Examples of such an adhesive film include those described in Patent Document 1.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] The adhesive film disposed between the metal terminal and the exterior material for the power storage device covers the periphery of the metal terminal by heat-sealing the exterior material with the adhesive film sandwiching the metal terminal from both sides, as shown in, for example, FIG. 9. However, if the positions of the two adhesive films are displaced when they are arranged, for example, as shown in FIG. 10, the overlapping portions of the two adhesive films are displaced and heat-sealed around the metal terminal. In such a case, there is a problem that the sealing performance of the heat-sealed portion becomes unstable and it is likely to induce a short circuit between the metal terminal and the barrier layer in the exterior material. For this reason, the adhesive film disposed between the metal terminal and the exterior material needs to be arranged with very high positional accuracy.

[0008] However, in the case of the adhesive film, when two adhesive films are arranged, or when one adhesive film is wound around the periphery of a metal terminal, a slight deviation in position may not be detectable by a sensor with a camera or visually, and heat sealing may be performed without correcting the deviation in position.

[0009] In addition, the adhesive film disposed between the metal terminal and the exterior material for the power storage device is also required to have high insulation performance in order to prevent a short circuit between the metal terminal and the barrier layer in the exterior material.

[0010] Under such circumstances, the main object of the present disclosure is to provide an adhesive film for a metal terminal that is interposed between a metal terminal electrically connected to an electrode of a power storage device element and an exterior material for the power storage device that seals the power storage device element, and that can be arranged with high positional accuracy with respect to the metal terminal and also has excellent insulation properties. Furthermore, the present disclosure also aims to provide a method for manufacturing the adhesive film for a metal terminal, a metal terminal with the adhesive film for a metal terminal, an exterior material for a power storage device, a kit including the exterior material for a power storage device and the adhesive film for a metal terminal, a power storage device, and a method for manufacturing the power storage device.

Means for Solving the Problems

[0011] The inventors of the present disclosure conducted intensive studies to solve the above problems. As a result, in an adhesive film for a metal terminal interposed between a metal terminal electrically connected to an electrode of a power storage device element and an exterior material for the power storage device that seals the power storage device element, it was found that by providing a resin layer A containing an insulating colorant, it is possible to arrange the film with high positional accuracy with respect to the metal terminal and excellent insulation performance is exhibited. The present disclosure was completed by further studies based on such findings.

[0012] That is, the present disclosure provides an invention in the following aspects. An adhesive film for a metal terminal interposed between a metal terminal electrically connected to an electrode of a power storage device element and an exterior material for a power storage device that seals the power storage device element, The adhesive film for a metal terminal includes a resin layer A containing an insulating coloring material.

Advantages of the Invention

[0013] According to the present disclosure, there is provided an adhesive film for a metal terminal interposed between a metal terminal electrically connected to an electrode of a power storage device element and an exterior material for a power storage device that seals the power storage device element, which can be arranged with high positional accuracy with respect to the metal terminal and has excellent insulation properties. Furthermore, the present disclosure also aims to provide a method for manufacturing the adhesive film for a metal terminal, a metal terminal with the adhesive film for a metal terminal, an exterior material for a power storage device, a kit including the exterior material for a power storage device and the adhesive film for a metal terminal, and a power storage device and a method for manufacturing the same.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Embodiments for Carrying Out the Invention

[0015] The adhesive film for a metal terminal of the present disclosure is an adhesive film for a metal terminal interposed between a metal terminal electrically connected to an electrode of a power storage device element and an exterior material for a power storage device that seals the power storage device element, and the adhesive film for a metal terminal is characterized by including a resin layer A containing an insulating coloring material.

[0016] Since the adhesive film for a metal terminal of the present disclosure has such characteristics, it can be arranged with high positional accuracy with respect to the metal terminal and also has excellent insulation properties.

[0017] Further, the power storage device of the present disclosure is a power storage device including at least a power storage device element including a positive electrode, a negative electrode, and an electrolyte, an exterior material for a power storage device that seals the power storage device element, and metal terminals electrically connected to the positive electrode and the negative electrode respectively and protruding outside the exterior material for a power storage device, and characterized in that the adhesive film for a metal terminal of the present disclosure is interposed between the metal terminal and the exterior material for a power storage device.

[0018] Hereinafter, the adhesive film for a metal terminal of the present disclosure, its manufacturing method, the power storage device, and its manufacturing method will be described in detail.

[0019] In addition, in this specification, for numerical ranges, the numerical range indicated by "~" means "or more" and "or less". For example, the notation "2~15 mm" means 2 mm or more and 15 mm or less. In the numerical ranges described step by step in this disclosure, the upper limit value or the lower limit value described in a certain numerical range may be replaced with the upper limit value or the lower limit value of the numerical range described in other step-by-step descriptions. Also, the upper limit value and the upper limit value, the upper limit value and the lower limit value, or the lower limit value and the lower limit value described separately may be combined to form a numerical range, respectively. Further, in the numerical ranges described in this disclosure, the upper limit value or the lower limit value described in a certain numerical range may be replaced with the value shown in the examples.

[0020] 1. Adhesive Film for Metal Terminals The adhesive film for metal terminals of the present disclosure is interposed between a metal terminal electrically connected to an electrode of a power storage device element and an exterior material for a power storage device that seals the power storage device element. Specifically, for example, as shown in FIGS. 1 to 3, the adhesive film 1 for metal terminals of the present disclosure is interposed between a metal terminal 2 electrically connected to an electrode of a power storage device element 4 and an exterior material 3 for a power storage device that seals the power storage device element 4. Further, the metal terminal 2 protrudes outside the exterior material 3 for a power storage device, and at the peripheral edge 3a of the heat-sealed exterior material 3 for a power storage device, it is sandwiched between the exterior material 3 for a power storage device via the adhesive film 1 for metal terminals.

[0021] In addition, in the present disclosure, the temporary adhesion process of the adhesive film for metal terminals to the metal terminals is performed, for example, under conditions of a temperature of about 140 to 160 °C, a pressure of about 0.01 to 1.0 MPa, a time of about 3 to 15 seconds, and a number of times of about 3 to 6 times. The main adhesion process is performed, for example, under conditions of a temperature of about 160 to 240 °C, a pressure of about 0.01 to 1.0 MPa, a time of about 3 to 15 seconds, and a number of times of about 1 to 3 times. Also, as the heating temperature when heat-sealing with the metal terminal with the adhesive film for metal terminals interposed between the exterior material for the power storage device, it is usually performed under conditions of a range of about 180 to 210 °C, a pressure of about 1.0 to 2.0 MPa, a time of about 3 to 5 seconds, and a number of times of about 1 time.

[0022] The adhesive film 1 for metal terminals of the present disclosure is provided to enhance the adhesion between the metal terminal 2 and the exterior material 3 for a power storage device. By enhancing the adhesion between the metal terminal 2 and the exterior material 3 for a power storage device, the sealing performance of the power storage device element 4 is improved. As described above, when heat-sealing the power storage device element 4, the metal terminal 2 electrically connected to the electrode of the power storage device element 4 protrudes outside the exterior material 3 for a power storage device, and the power storage device element is sealed. At this time, since the metal terminal 2 formed of metal and the heat-sealing resin layer 35 (a layer formed of a heat-sealing resin such as polyolefin) located in the innermost layer of the exterior material 3 for a power storage device are made of different materials, if such an adhesive film is not used, the sealing performance of the power storage device element tends to be low at the interface between the metal terminal 2 and the heat-sealing resin layer 35.

[0023] [Resin layer A] The adhesive film 1 for metal terminals of the present disclosure includes at least a resin layer A. The resin layer A is a resin layer containing an insulating colorant.

[0024] The resin layer A may be a layer that forms at least one surface of the adhesive film 1 for metal terminals (i.e., the outermost layer, such as the first resin layer 12a and the second resin layer 12b described later), or may be a layer that does not constitute the surface (such as the intermediate layer 11 and the adhesion promoter layer 13 described later).

[0025] Within the limit of achieving the effects of the present disclosure, the adhesive film 1 for metal terminals of the present disclosure may be a single layer as shown in FIG. 4, or may be a multi-layer as shown in FIGS. 5 to 7.

[0026] When the adhesive film 1 for metal terminals of the present disclosure is a single layer, the adhesive film 1 for metal terminals is composed of a resin layer A, and the surface on the metal terminal side and the surface of the exterior material for the power storage device are formed by the resin layer A. In this case, the resin forming the surface of the adhesive film 1 for metal terminals on the side of the exterior material for the power storage device and the resin forming the surface on the metal terminal side are the same resin (that is, the resin forming the resin layer A). Note that the fact that the resin forming the surface of the adhesive film 1 for metal terminals on the side of the exterior material for the power storage device and the resin forming the surface on the metal terminal side are the same means that, for example, 80% by mass or more, 90% by mass or more, 95% by mass or more, or 100% by mass of the components in these resins are the same.

[0027] When the adhesive film 1 for metal terminals of the present disclosure is a multilayer, for example, as shown in FIG. 5, when the adhesive film 1 for metal terminals of the present disclosure has a two-layer structure, the adhesive film 1 for metal terminals is a laminate of a first resin layer 12a and a second resin layer 12b, and at least one of the first resin layer 12a and the second resin layer 12b is a resin layer A. Even when the adhesive film 1 for metal terminals of the present disclosure is a multilayer, the resin forming the surface on the side of the exterior material for the power storage device and the resin forming the surface on the metal terminal side may be the same resin.

[0028] For example, as shown in FIG. 6, when the adhesive film 1 for metal terminals of the present disclosure has a three-layer structure, the adhesive film 1 for metal terminals is a laminate in which a first resin layer 12a, an intermediate layer 11, and a second resin layer 12b are laminated in this order, and at least one of the first resin layer 12a, the intermediate layer 11, and the second resin layer 12b is a resin layer A. In the present disclosure, the first resin layer 12a constitutes the surface on the metal terminal side, and the second resin layer 12b constitutes the surface on the side of the exterior material for the power storage device.

[0029] In the adhesive film 1 for metal terminals of the present disclosure, the resin layer A preferably has heat fusibility with respect to a metal (the metal constituting the metal terminal). In this case, the resin layer A can be disposed on the metal terminal side of the adhesive film 1 for metal terminals and used. For example, in the present disclosure, at least the first resin layer 12a among the first resin layer 12a and the second resin layer 12b can be formed by the resin layer A.

[0030] The surface (for example, the second resin layer 12b) on the side of the exterior material for the power storage device of the adhesive film 1 for metal terminals of the present disclosure has heat fusibility with respect to the heat-fusible resin layer described later. The resin layer A preferably also has heat fusibility with respect to the heat-fusible resin layer described later. The resin layer A can be disposed on the side of the exterior material for the power storage device of the adhesive film 1 for metal terminals and used. For example, in the present disclosure, at least the second resin layer 12b among the first resin layer 12a and the second resin layer 12b can be formed by the resin layer A.

[0031] Also, the resin layer A can be used as the intermediate layer 11 located between the first resin layer 12a and the second resin layer 12b.

[0032] The resin layer A is a layer containing an insulating colorant. That is, the resin layer A contains an insulating colorant and a resin.

[0033] The insulating colorant is not particularly limited as long as it is insulating and can color the resin layer.

[0034] From the viewpoint of more suitably exhibiting the effects of the present disclosure, the electrical resistivity of the insulating colorant is preferably about 0.01 Ω·cm or more, more preferably about 0.1 Ω·cm or more, still more preferably about 1 Ω·cm or more, still more preferably about 5 Ω·cm or more, still more preferably 7 Ω·cm or more, and still more preferably 10 Ω·cm or more. Also, it is preferably about 10 13 Ω·cm or less, more preferably about 10 12 Ω·cm or less, still more preferably about 10 11 Ω·cm or less, and the preferable range is 0.01 to 1013 Ω·cm, 0.01 to 10 12 Ω·cm, 0.01 to 10 11 Ω·cm, 0.1 to 10 13 Ω·cm, 0.1 to 10 12 Ω·cm, 0.1 to 10 11 Ω·cm, 1 to 10 13 Ω·cm, 1 to 10 12 Ω·cm, 1 to 10 11 Ω·cm, 5 to 10 13 Ω·cm, 5 to 10 12 Ω·cm, 5 to 10 11 Ω·cm, 7 to 10 13 Ω·cm, 7 to 10 12 Ω·cm, 7 to 10 11 Ω·cm, 10 to 10 13 Ω·cm, 10 to 10 12 Ω·cm, 10 to 10 11 Ω·cm0 etc. The electrical resistivity of the insulating colorant is the value measured by the method specified in JIS K 7194:1994.

[0035] From the viewpoint of more preferably exerting the effects of the present disclosure, the average particle diameter of the insulating colorant is preferably about 300 nm or less, more preferably about 200 nm or less, still more preferably about 100 nm or less, and also preferably about 10 nm or more, more preferably about 20 nm or more, still more preferably about 30 nm or more, and even more preferably about 50 nm or more. The preferable ranges include about 10 to 300 nm, about 10 to 200 nm, about 10 to 100 nm, about 20 to 300 nm, about 20 to 200 nm, about 20 to 100 nm, about 30 to 300 nm, about 30 to 200 nm, about 30 to 100 nm, about 50 to 300 nm, about 50 to 200 nm, and about 50 to 100 nm. Note that the average particle diameter of the insulating colorant is the median diameter measured by a laser diffraction / scattering particle size distribution measuring device.

[0036] Specific examples of insulating coloring materials include insulating inorganic particles such as titanium nitride (titanium black), insulating carbon, zirconia black, alumina, and ceramics. The insulating inorganic particles are unlikely to dissolve in the electrolyte solution. Furthermore, the insulating inorganic particles have a significant coloring effect, and can achieve a sufficient coloring effect even when added in an amount that does not impair adhesion. Furthermore, the insulating inorganic particles do not melt due to heat, and can increase the apparent melt viscosity of the resin to which they are added. Furthermore, they can prevent the pressure-applied portion from becoming thin during thermal bonding (heat sealing), thereby providing excellent sealing between the exterior material for an electricity storage device and the metal terminal. The insulating coloring material contained in the resin layer A may be one type or two or more types. Among these insulating coloring materials, titanium nitride (titanium black) is particularly preferred from the viewpoint of more suitably exhibiting the effects of the present disclosure.

[0037] The color of the insulating color material is not particularly limited, but from the viewpoint of more suitably exhibiting the effects of the present disclosure, black, gray, etc. are preferred, and black is particularly preferred. The resin layer A can be colored in a color corresponding to the color of the insulating color material, and the adhesive film for metal terminal 1 of the present disclosure allows the color of the resin layer A to be visually recognized from the outside.

[0038] Resin layer A is measured using the SCI method, a field of view of 10°, and light source F2. * a * b * L in color space * The value is preferably about 90 or less, more preferably about 80 or less, even more preferably about 70 or less, and is preferably about 10 or more, more preferably about 20 or more, even more preferably about 30 or more, even more preferably about 40 or more, and even more preferably about 57 or more. Preferred ranges include about 10 to 90, about 10 to 80, about 10 to 70, about 20 to 90, about 20 to 80, about 20 to 70, about 30 to 90, about 30 to 80, about 30 to 70, about 40 to 90, about 40 to 80, about 40 to 70, about 57 to 90, about 57 to 80, and about 57 to 70.

[0039] From the viewpoint of more preferably exerting the effects of the present disclosure, the content of the insulating colorant in the resin layer A is preferably about 50% by mass or less, more preferably about 40% by mass or less, still more preferably about 30% by mass or less, even more preferably about 20% by mass or less, and preferably about 0.01% by mass or more, more preferably about 0.1% by mass or more. Preferred ranges include about 0.01 to 50% by mass, about 0.01 to 40% by mass, about 0.01 to 30% by mass, about 0.01 to 20% by mass, about 0.1 to 50% by mass, about 0.1 to 40% by mass, about 0.1 to 30% by mass, and about 0.1 to 20% by mass.

[0040] Examples of the resin contained in the resin layer A include polyolefin resins, polyamide resins, polyester resins, epoxy resins, acrylic resins, fluorine resins, silicone resins, phenolic resins, polyetherimides, polyimides, polycarbonates, and mixtures and copolymers thereof. Among these, polyolefin resins are particularly preferred. Examples of the polyolefin resin include polyolefins and acid-modified polyolefins.

[0041] From the viewpoint of more preferably exerting the effects of the present disclosure, the resin layer A preferably contains a polyolefin resin (i.e., has a polyolefin backbone), more preferably contains a polyolefin, and still more preferably is a layer formed of a polyolefin. Among the polyolefin resins, the resin layer A preferably contains a polyolefin or an acid-modified polyolefin. Further, the polyolefin is preferably polypropylene, and the acid-modified polyolefin is preferably acid-modified polypropylene.

[0042] The resin contained in the resin layer A may be only one type or two or more types. From the viewpoint of film-forming properties, the resin of the resin layer A is preferably a blend polymer obtained by combining two or more resin components. When it is a blend polymer, for example, in the case of the resin layer A containing acid-modified polypropylene, acid-modified polypropylene is used as the main component (component of 50% by mass or more), and 50% by mass or less is made of other resins (preferably polyethylene from the viewpoint of improving flexibility). Further, in the case of the resin layer A containing polypropylene, polypropylene is used as the main component (component of 50% by mass or more), and 50% by mass or less is made of other resins (preferably polyethylene from the viewpoint of improving flexibility). On the other hand, from the viewpoint of the electrolytic solution resistance of the resin layer A, the resin layer A containing acid-modified polypropylene preferably contains acid-modified polypropylene alone as the resin, and the resin layer A containing polypropylene preferably contains acid-modified polypropylene or polypropylene alone as the resin.

[0043] Since it has excellent adhesion to the metal terminal, the resin layer A preferably contains an acid-modified polyolefin. From the viewpoint of more preferably exhibiting the effects of the present disclosure, the resin layer A is preferably formed of an acid-modified polyolefin containing an insulating colorant. That is, the resin layer A can be preferably configured by an acid-modified polyolefin film containing an insulating colorant.

[0044] The acid-modified polyolefin is not particularly limited as long as it is an acid-modified polyolefin, but preferably includes a polyolefin graft-modified with an unsaturated carboxylic acid or its anhydride.

[0045] Examples of the polyolefin to be acid-modified include, specifically, polyethylene such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene; crystalline or amorphous polypropylene 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); and terpolymers of ethylene-butene-propylene. Among these polyolefins, polyethylene and polypropylene are preferable, and polypropylene is particularly preferable.

[0046] Further, the polyolefin to be acid-modified may be a cyclic polyolefin. For example, a carboxylic acid-modified cyclic polyolefin is a polymer obtained by copolymerizing a part of the monomers constituting the cyclic polyolefin by replacing them with an α,β-unsaturated carboxylic acid or its anhydride, or by block-polymerizing or graft-polymerizing an α,β-unsaturated carboxylic acid or its anhydride onto the cyclic polyolefin.

[0047] The cyclic polyolefin to be acid-modified is a copolymer of an olefin and a cyclic monomer. Examples of the olefin that is a constituent monomer of the cyclic polyolefin include ethylene, propylene, 4-methyl-1-pentene, butadiene, isoprene, and the like. Examples of the cyclic monomer that is a constituent monomer of the cyclic polyolefin include cyclic alkenes such as norbornene; specifically, cyclic dienes such as cyclopentadiene, dicyclopentadiene, cyclohexadiene, and norbornadiene. Among these polyolefins, cyclic alkenes are preferable, and norbornene is more preferable. Styrene is also included as a constituent monomer.

[0048] Examples of the carboxylic acid or its anhydride used for acid modification include maleic acid, acrylic acid, itaconic acid, crotonic acid, maleic anhydride, itaconic anhydride, and the like. When the resin layer A is analyzed by infrared spectroscopy, it is preferable that a peak derived from maleic anhydride is detected. For example, when measuring maleic anhydride-modified polyolefin by infrared spectroscopy, peaks derived from maleic anhydride are detected in the vicinity of a wave number of 1760 cm -1 and in the vicinity of a wave number of 1780 cm -1 . When the resin layer A is a layer composed of maleic anhydride-modified polyolefin, peaks derived from maleic anhydride are detected when measured by infrared spectroscopy. However, if the degree of acid modification is low, the peak may become small and not be detected. In that case, it can be analyzed by nuclear magnetic resonance spectroscopy.

[0049] In the resin layer A, within the limit of not inhibiting the effects of the present disclosure, in addition to the insulating colorant and the resin, known additives such as fillers may further be contained as necessary.

[0050] For example, the resin layer A may contain a filler as necessary. Since the filler functions as a spacer when the resin layer A contains the filler, it is possible to effectively suppress a short circuit between the metal terminal 2 and the barrier layer 33 of the exterior material 3 for the power storage device. Examples of the particle size of the filler include a range of about 0.1 to 35 μm, preferably about 5.0 to 30 μm, and more preferably about 10 to 25 μm. Examples of the content of the filler include about 5 to 30 parts by mass, more preferably about 10 to 20 parts by mass, respectively, with respect to 100 parts by mass of the resin component forming the resin layer A.

[0051] As the filler, either an inorganic filler or an organic filler can be used. Examples of the inorganic filler include carbon (carbon, graphite), silica, aluminum oxide, barium titanate, iron oxide, silicon carbide, zirconium oxide, zirconium silicate, magnesium oxide, titanium oxide, calcium aluminate, calcium hydroxide, aluminum hydroxide, magnesium hydroxide, calcium carbonate, etc. Examples of the organic filler include fluororesin, phenol resin, urea resin, epoxy resin, acrylic resin, benzoguanamine formaldehyde condensate, melamine formaldehyde condensate, polymethyl methacrylate cross-linked product, polyethylene cross-linked product, etc. From the viewpoints of shape stability, rigidity, and resistance to the content, aluminum oxide, silica, fluororesin, acrylic resin, and benzoguanamine formaldehyde condensate are preferable, and among them, spherical aluminum oxide and silica are more preferable. As a method for mixing the filler into the resin component for forming the resin layer A, a method of melt-blending the two in advance with a Banbury mixer or the like to prepare a masterbatch and then adjusting it to a predetermined mixing ratio, a method of directly mixing with the resin component, etc. can be adopted.

[0052] In addition, when adding a filler to the resin layer A, an insulating colorant and a pigment may be added to the resin layer A, but from the viewpoint of not inhibiting the heat fusion property of the adhesive film 1 for metal terminals, it is preferable to add the filler and the pigment separately to different layers (for example, the first resin layer 12a, the second resin layer 12b, the intermediate layer 11, etc. described later).

[0053] From the viewpoint of more suitably achieving the effects of the present disclosure, the melting peak temperature of the resin layer A is preferably 110°C or higher, more preferably about 120°C or higher, and still more preferably about 130°C or higher. From the same viewpoint, the melting peak temperature is, for example, 200°C or lower, preferably 190°C or lower, more preferably 180°C or lower, still more preferably about 175°C or lower, and still more preferably about 170°C or lower. Preferred ranges of the melting peak temperature include about 110 to 200°C, about 110 to 190°C, about 110 to 180°C, about 110 to 175°C, about 110 to 170°C, about 120 to 200°C, about 120 to 190°C, about 120 to 180°C, about 120 to 175°C, about 120 to 170°C, about 130 to 200°C, about 130 to 190°C, about 130 to 180°C, about 130 to 175°C, and about 130 to 170°C. In the present disclosure, the method for measuring the melting peak temperature is as follows.

[0054] <Measurement of Melting Peak Temperature> For the adhesive film, the melting peak temperature is measured in accordance with the provisions of JIS K7121:2012 (Test Method for Transition Temperature of Plastics (Addendum to JIS K7121:1987)). The measurement is performed using a differential scanning calorimeter (DSC). The measurement sample is held at -50°C for 15 minutes, then heated from -50°C to 210°C at a heating rate of 10°C / min to measure the first melting peak temperature P (°C), and then held at 210°C for 10 minutes. Next, it is cooled from 210°C to -50°C at a cooling rate of 10°C / min and held for 15 minutes. Further, it is heated from -50°C to 210°C at a heating rate of 10°C / min to measure the second melting peak temperature Q (°C). The flow rate of nitrogen gas is set to 50 ml / min. By the above procedure, the melting peak temperature P (°C) measured for the first time and the melting peak temperature Q (°C) measured for the second time are obtained. By the above procedure, the value of the melting peak temperature P (°C) measured for the first time is adopted.

[0055] When the adhesive film 1 for metal terminals of the present disclosure is composed of a single layer of the resin layer A, the total thickness of the adhesive film 1 for metal terminals described later corresponds to the thickness of the resin layer A.

[0056] When the adhesive film 1 for metal terminals of the present disclosure is composed of multiple layers, from the viewpoint of more preferably achieving the effects of the present disclosure, the thickness of the resin layer A is preferably about 20 μm or more, more preferably about 30 μm or more, still more preferably about 40 μm or more, and is preferably about 200 μm or less, more preferably about 150 μm or less, still more preferably 100 μm or less. Preferred ranges for the thickness of the resin layer A include about 20 to 200 μm, about 20 to 150 μm, about 20 to 100 μm, about 30 to 200 μm, about 30 to 150 μm, about 30 to 100 μm, about 40 to 200 μm, about 40 to 150 μm, and about 40 to 100 μm. When the adhesive film 1 for metal terminals of the present disclosure contains a plurality of resin layers A, it is preferable that the thickness of each resin layer A is the above-mentioned thickness respectively.

[0057] Also, when the adhesive film 1 for metal terminals of the present disclosure has a resin layer A as the first resin layer 12a, from the viewpoint of more preferably achieving the effects of the present disclosure, the thickness of the resin layer A is preferably about 20 μm or more, more preferably about 30 μm or more, still more preferably about 40 μm or more, and is preferably about 200 μm or less, more preferably about 150 μm or less, still more preferably 100 μm or less. Preferred ranges for the thickness of the resin layer A include about 20 to 200 μm, about 20 to 150 μm, about 20 to 100 μm, about 30 to 200 μm, about 30 to 150 μm, about 30 to 100 μm, about 40 to 200 μm, about 40 to 150 μm, and about 40 to 100 μm.

[0058] In addition, when the adhesive film 1 for metal terminals of the present disclosure has a resin layer A as the second resin layer 12b, from the viewpoint of more preferably achieving the effects of the present disclosure, the thickness of the resin layer A is preferably about 20 μm or more, more preferably about 30 μm or more, still more preferably about 40 μm or more, and is preferably about 200 μm or less, more preferably about 150 μm or less, still more preferably 100 μm or less. Preferred ranges for the thickness of the resin layer A include about 20 to 200 μm, about 20 to 150 μm, about 20 to 100 μm, about 30 to 200 μm, about 30 to 150 μm, about 30 to 100 μm, about 40 to 200 μm, about 40 to 150 μm, and about 40 to 100 μm.

[0059] In addition, when the adhesive film 1 for metal terminals of the present disclosure has a resin layer A as the intermediate layer 11, from the viewpoint of more preferably achieving the effects of the present disclosure, the thickness of the resin layer A is preferably about 20 μm or more, more preferably about 30 μm or more, still more preferably about 40 μm or more, and is preferably about 200 μm or less, more preferably about 150 μm or less, still more preferably 100 μm or less. Preferred ranges for the thickness of the resin layer A include about 20 to 200 μm, about 20 to 150 μm, about 20 to 100 μm, about 30 to 200 μm, about 30 to 150 μm, about 30 to 100 μm, about 40 to 200 μm, about 40 to 150 μm, and about 40 to 100 μm.

[0060] As described above, the adhesive film 1 for metal terminals of the present disclosure can have a configuration in which at least a first resin layer 12a, an intermediate layer 11, and a second resin layer 12b are laminated in this order, as shown in FIG. 6, for example. In the adhesive film 1 for metal terminals of the present disclosure, in this configuration, the first resin layer 12a is disposed on the side of the metal terminal 2, and the second resin layer 12b is disposed on the side of the exterior material 3 for the power storage device. In this configuration, the first resin layer 12a and the second resin layer 12b are located on the surfaces on both sides, respectively.

[0061] The second resin layer 12b is a layer composed of resin. The second resin layer 12b may be formed by the resin layer A, or may be formed by a resin layer B different from the resin layer A (that is, the resin layer B is a resin layer that does not contain an insulating colorant).

[0062] Also, the intermediate layer 11 may be formed by the resin layer A, or may be formed by a resin layer B different from the resin layer A.

[0063] When the adhesive film 1 for metal terminals of the present disclosure includes two or more resin layers A or resin layer B, preferable laminated configurations include, for example, a laminated configuration in which the resin layer A / resin layer A / intermediate layer / resin layer B are laminated in this order, a laminated configuration in which the resin layer B / resin layer A / intermediate layer / resin layer B are laminated in this order, a laminated configuration in which the resin layer B / intermediate layer / resin layer A / resin layer B are laminated in this order, and the like.

[0064] The surface resistivity of the resin layer A measured in accordance with the provisions of JIS K 7194:1994 is preferably about 1×10 6 Ω / □ or more, more preferably about 1×10 8 Ω / □ or more, still more preferably about 1×10 10 Ω / □ or more, still more preferably 1×10 12 Ω / □ or more, and usually about 1×10 16 Ω / □ or less, and the preferable range is 1×10 6 ~1×10 16 Ω / □ or so, 1×10 8 ~1×10 16 Ω / □ or so, 1×10 10 ~1×10 16 Ω / □ or so, 1×10 12 ~1×10 16 Ω / □ or so.

[0065] [Resin layer B] The resin layer B is a resin layer different from the resin layer A (that is, the resin layer B is a resin layer that does not contain an insulating colorant).

[0066] Examples of the resin constituting the resin layer B include polyolefin resins, polyamide resins, polyester resins, epoxy resins, acrylic resins, fluorine resins, silicone resins, phenol resins, polyetherimides, polyimides, polycarbonates, mixtures and copolymers thereof, etc. Among these, polyolefin resins are particularly preferred. Examples of the polyolefin resin include polyolefin and acid-modified polyolefin.

[0067] The resin contained in the resin layer B may be only one type or two or more types. From the viewpoint of film-forming properties, the resin of the resin layer B is preferably a blend polymer obtained by combining two or more resin components. When using a blend polymer, for example, in the case of a resin layer B containing acid-modified polypropylene, it is preferable that acid-modified polypropylene is the main component (50% by mass or more of the component), and 50% by mass or less is another resin (preferably polyethylene from the viewpoint of improving flexibility). Also, in the case of a resin layer B containing polypropylene, it is preferable that polypropylene is the main component (50% by mass or more of the component), and 50% by mass or less is another resin (preferably polyethylene from the viewpoint of improving flexibility). On the other hand, from the viewpoint of the electrolyte resistance of the resin layer B, the resin layer B containing acid-modified polypropylene preferably contains acid-modified polypropylene alone as the resin, and the resin layer B containing polypropylene preferably contains acid-modified polypropylene or polypropylene alone as the resin.

[0068] The melting peak temperature of the resin layer B is preferably 110°C or higher, more preferably about 120°C or higher, still more preferably about 130°C or higher. The melting peak temperature is, for example, 200°C or lower, preferably 190°C or lower, more preferably 180°C or lower, still more preferably about 175°C or lower, and still more preferably about 170°C or lower. Preferred ranges of the melting peak temperature include about 110 to 200°C, about 110 to 190°C, about 110 to 180°C, about 110 to 175°C, about 110 to 170°C, about 120 to 200°C, about 120 to 190°C, about 120 to 180°C, about 120 to 175°C, about 120 to 170°C, about 130 to 200°C, about 130 to 190°C, about 130 to 180°C, about 130 to 175°C, about 130 to 170°C.

[0069] When the adhesive film 1 for metal terminals of the present disclosure has the resin layer B as the first resin layer 12a, from the viewpoint of more suitably achieving the effects of the present disclosure, the thickness of the resin layer B is preferably about 20 μm or more, more preferably about 30 μm or more, still more preferably about 40 μm or more, and is also preferably about 200 μm or less, more preferably about 150 μm or less, still more preferably 100 μm or less. Preferred ranges of the thickness of the resin layer B include about 20 to 200 μm, about 20 to 150 μm, about 20 to 100 μm, about 30 to 200 μm, about 30 to 150 μm, about 30 to 100 μm, about 40 to 200 μm, about 40 to 150 μm, about 40 to 100 μm.

[0070] Further, when the adhesive film 1 for metal terminals of the present disclosure has the resin layer B as the second resin layer 12b, from the viewpoint of more preferably achieving the effects of the present disclosure, the thickness of the resin layer B is preferably about 20 μm or more, more preferably about 30 μm or more, still more preferably about 40 μm or more, and is preferably about 200 μm or less, more preferably about 150 μm or less, still more preferably 100 μm or less. Preferable ranges of the thickness of the resin layer B include about 20 to 200 μm, about 20 to 150 μm, about 20 to 100 μm, about 30 to 200 μm, about 30 to 150 μm, about 30 to 100 μm, about 40 to 200 μm, about 40 to 150 μm, and about 40 to 100 μm.

[0071] Further, when the adhesive film 1 for metal terminals of the present disclosure has the resin layer B as the intermediate layer 11, from the viewpoint of more preferably achieving the effects of the present disclosure, the thickness of the resin layer B is preferably about 20 μm or more, more preferably about 30 μm or more, still more preferably about 40 μm or more, and is preferably about 200 μm or less, more preferably about 150 μm or less, still more preferably 100 μm or less. Preferable ranges of the thickness of the resin layer B include about 20 to 200 μm, about 20 to 150 μm, about 20 to 100 μm, about 30 to 200 μm, about 30 to 150 μm, about 30 to 100 μm, about 40 to 200 μm, about 40 to 150 μm, and about 40 to 100 μm.

[0072] The resin layer B may also contain known additives (such as pigments and fillers), similar to the resin layer A. For example, the resin layer B may contain a pigment. As the pigment, various inorganic pigments can be used. As a specific example of the pigment, carbon (carbon, graphite) exemplified as the filler above can be preferably cited. Carbon (carbon, graphite) is a material generally used inside the power storage device and has no risk of elution into the electrolyte. Also, with an addition amount that provides a sufficient coloring effect without significantly inhibiting adhesiveness and without melting by heat, the apparent melt viscosity of the added resin can be increased. Furthermore, it can prevent the pressure-applied part from becoming thin during heat adhesion (heat sealing), and excellent sealing performance can be imparted between the exterior material for the power storage device and the metal terminal. Also, for example, the resin layer B may contain a filler. The type and addition amount of the filler are the same as those of the resin layer A.

[0073] The surface resistivity of the resin layer B measured in accordance with the provisions of JIS K 7194:1994 is preferably about 1×10 6 Ω / sq or more, more preferably about 1×10 8 Ω / sq or more, even more preferably about 1×10 10 Ω / sq or more, even more preferably 1×10 12 Ω / sq or more, and usually about 1×10 16 Ω / sq or less. The preferable range is 1×10 6 ~1×10 16 Ω / sq level, 1×10 8 ~1×10 16 Ω / sq level, 1×10 10 ~1×10 16 Ω / sq level, 1×10 12 ~1×10 16 Ω / sq level, etc. can be mentioned.

[0074] The resin layer B may be colored or colorless and transparent.

[0075] From the perspective of more suitably achieving the effects of the present disclosure, the total thickness of the adhesive film 1 for metal terminals is, for example, about 50 μm or more, preferably about 100 μm or more, and more preferably about 150 μm or more. Also, the total thickness of the adhesive film 1 for metal terminals of the present disclosure is preferably about 400 μm or less, more preferably about 350 μm or less, and even more preferably about 300 μm or less. Preferred ranges for the total thickness of the adhesive film 1 for metal terminals of the present disclosure include about 50 to 400 μm, about 50 to 350 μm, about 50 to 300 μm, about 100 to 400 μm, about 100 to 350 μm, about 100 to 300 μm, about 150 to 400 μm, about 150 to 350 μm, and about 150 to 300 μm.

[0076] The adhesive film 1 for metal terminals of the present disclosure preferably has fine irregularities on at least one surface of the outermost layer. Thereby, the adhesion with the heat-fusible resin layer 35 or the metal terminal 2 of the exterior material 3 for the power storage device can be further improved. As a method for forming fine irregularities on the surface of the outermost layer of the adhesive film 1 for metal terminals, methods such as adding an additive such as fine particles to the outermost layer and molding by bringing into contact a cooling roll having irregularities on the surface can be mentioned. As the fine irregularities, preferably, the ten-point average roughness of the surface of the outermost layer is preferably about 0.1 μm or more, more preferably about 0.2 μm or more, and also preferably about 35 μm or less, more preferably about 10 μm or less. Preferred ranges include about 0.1 to 35 μm, about 0.1 to 10 μm, about 0.2 to 35 μm, and about 0.2 to 10 μm. The ten-point average roughness is a value measured under the measurement conditions of a magnification of 50 times of the objective lens and no cut-off using a Keyence laser microscope VK-9710 in accordance with the method specified in JIS B0601:1994.

[0077] The adhesive film 1 for metal terminals of the present disclosure is preferably formed of a polyolefin-based resin. For example, the resin component contained in the adhesive film 1 for metal terminals of the present disclosure is preferably only an acid-modified polyolefin or only an acid-modified polyolefin and a polyolefin. Preferred acid-modified polyolefins and polyolefins are as described in the resin layer A and the resin layer B.

[0078] The adhesive film 1 for metal terminals of the present disclosure is preferably composed of a laminate including a first resin layer 12a, an intermediate layer 11, and a second resin layer 12b in this order. Hereinafter, taking as an example the case where the adhesive film 1 for metal terminals of the present disclosure is composed of a laminate including at least the first resin layer 12a, the intermediate layer 11, and the second resin layer 12b in this order, the preferred embodiments of the adhesive film 1 for metal terminals of the present disclosure will be described in detail.

[0079] When the adhesive film 1 for metal terminals of the present disclosure is disposed between the metal terminal 2 of the power storage device 10 and the exterior member 3 for the power storage device, the surface of the metal terminal 2 made of metal and the heat-sealing resin layer 35 (a layer formed of a heat-sealing resin such as polyolefin) of the exterior member 3 for the power storage device are adhered via the adhesive film 1 for metal terminals. The first resin layer 12a of the adhesive film 1 for metal terminals is disposed on the metal terminal 2 side, the second resin layer 12b is disposed on the exterior member 3 side for the power storage device, the first resin layer 12a is in close contact with the metal terminal 2, and the second resin layer 12b is in close contact with the heat-sealing resin layer 35 of the exterior member 3 for the power storage device.

[0080] [First Resin Layer 12a and Second Resin Layer 12b] As shown in FIG. 6, the adhesive film 1 for metal terminals according to a preferred embodiment of the present disclosure includes a first resin layer 12a on one surface side of the intermediate layer 11 and a second resin layer 12b on the other surface side. The first resin layer 12a is disposed on the metal terminal 2 side. Also, the second resin layer 12b is disposed on the exterior member 3 side for the power storage device. In the adhesive film 1 for metal terminals of the present disclosure, the first resin layer 12a and the second resin layer 12b are located on the surfaces on both sides, respectively.

[0081] In the present disclosure, at least one of the first resin layer 12a, the intermediate layer 11, and the second resin layer 12b is formed of the aforementioned resin layer A.

[0082] As described above, the first resin layer 12a and the second resin layer 12b preferably each contain a polyolefin-based resin (i.e., have a polyolefin backbone), more preferably contain a polyolefin, and even more preferably are layers formed of a polyolefin. Among polyolefin-based resins, the first resin layer 12a preferably contains a polyolefin or an acid-modified polyolefin, more preferably contains an acid-modified polyolefin, and even more preferably is a layer formed of an acid-modified polyolefin film. The polyolefin-based resin is preferably a polypropylene-based resin. Among polyolefin-based resins, the second resin layer 12b preferably contains a polyolefin or an acid-modified polyolefin, more preferably contains a polyolefin, and even more preferably is a layer formed of a polyolefin film. The polyolefin-based resin is preferably a polypropylene-based resin. The polyolefin is preferably polypropylene, and the acid-modified polyolefin is preferably polypropylene.

[0083] The melting peak temperature of the first resin layer 12a is preferably 110°C or higher, more preferably about 120°C or higher, and even more preferably about 130°C or higher. The melting peak temperature is, for example, 200°C or lower, preferably 190°C or lower, more preferably 180°C or lower, even more preferably about 175°C or lower, and even more preferably about 170°C or lower. Preferred ranges for the melting peak temperature include about 110 - 200°C, about 110 - 190°C, about 110 - 180°C, about 110 - 175°C, about 110 - 170°C, about 120 - 200°C, about 120 - 190°C, about 120 - 180°C, about 120 - 175°C, about 120 - 170°C, about 130 - 200°C, about 130 - 190°C, about 130 - 180°C, about 130 - 175°C, and about 130 - 170°C.

[0084] The melting peak temperature of the second resin layer 12b is preferably 110°C or higher, more preferably about 120°C or higher, and still more preferably about 130°C or higher. The melting peak temperature is, for example, 200°C or lower, preferably 190°C or lower, more preferably 180°C or lower, still more preferably about 175°C or lower, and still more preferably about 170°C or lower. The preferable range of the melting peak temperature is about 110 - 200°C, about 110 - 190°C, about 110 - 180°C, about 110 - 175°C, about 110 - 170°C, about 120 - 200°C, about 120 - 190°C, about 120 - 180°C, about 120 - 175°C, about 120 - 170°C, about 130 - 200°C, about 130 - 190°C, about 130 - 180°C, about 130 - 175°C, about 130 - 170°C.

[0085] From the viewpoint of more suitably achieving the effects of the present disclosure, the thickness of the first resin layer 12a is preferably about 20 μm or more, more preferably about 30 μm or more, and still more preferably about 40 μm or more, and is also preferably about 200 μm or less, more preferably about 150 μm or less, and still more preferably 100 μm or less. The preferable range of the thickness of the first resin layer 12a is about 20 - 200 μm, about 20 - 150 μm, about 20 - 100 μm, about 30 - 200 μm, about 30 - 150 μm, about 30 - 100 μm, about 40 - 200 μm, about 40 - 150 μm, about 40 - 100 μm.

[0086] Also, from the viewpoint of more suitably achieving the effects of the present disclosure, the thickness of the second resin layer 12b is preferably about 20 μm or more, more preferably about 30 μm or more, and still more preferably about 40 μm or more, and is also preferably about 200 μm or less, more preferably about 150 μm or less, and still more preferably 100 μm or less. The preferable range of the thickness of the second resin layer 12b is about 20 - 200 μm, about 20 - 150 μm, about 20 - 100 μm, about 30 - 200 μm, about 30 - 150 μm, about 30 - 100 μm, about 40 - 200 μm, about 40 - 150 μm, about 40 - 100 μm.

[0087] [Intermediate layer 11] In the adhesive film 1 for metal terminals, the intermediate layer 11 is a layer that functions as a support for the adhesive film 1 for metal terminals.

[0088] The intermediate layer 11 may be formed of the aforementioned resin layer A or may be formed of the aforementioned resin layer B.

[0089] The material for forming the intermediate layer 11 is not particularly limited. Examples of the material for forming the intermediate layer 11 include polyolefin resins, polyamide resins, polyester resins, epoxy resins, acrylic resins, fluorine resins, silicone resins, phenolic resins, polyetherimides, polyimides, polycarbonates, and mixtures and copolymers thereof. Among these, polyolefin resins are particularly preferred. That is, the material for forming the intermediate layer 11 is preferably a resin containing a polyolefin backbone such as polyolefin or acid-modified polyolefin. Whether the resin constituting the intermediate layer 11 contains a polyolefin backbone can be analyzed by, for example, infrared spectroscopy, gas chromatography-mass spectrometry, etc.

[0090] As described above, the intermediate layer 11 preferably contains a polyolefin-based resin, preferably contains a polyolefin, and is more preferably a layer formed of a polyolefin. The layer formed of a polyolefin may be a stretched polyolefin film or an unstretched polyolefin film, but an unstretched polyolefin film is preferred. Specific examples of the polyolefin include polyethylene such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene; crystalline or amorphous polypropylene 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); and terpolymers of ethylene-butene-propylene. Among these polyolefins, polyethylene and polypropylene are preferred, and polypropylene is more preferred. Further, since it has excellent electrolytic solution resistance, the intermediate layer 11 preferably contains homopolypropylene, is more preferably formed of homopolypropylene, and is even more preferably an unstretched homopolypropylene film.

[0091] Examples of the polyamide include aliphatic polyamides such as nylon 6, nylon 66, nylon 610, nylon 12, nylon 46, and copolymers of nylon 6 and nylon 66; hexamethylenediamine-isophthalic acid-terephthalic acid copolymer polyamides such as nylon 6I, nylon 6T, nylon 6IT, and nylon 6I6T (where I represents isophthalic acid and T represents terephthalic acid), which contain structural units derived from terephthalic acid and / or isophthalic acid, and polyamides containing aromatics such as polymetaxylylene adipamide (MXD6); alicyclic polyamides such as polyaminomethylcyclohexyl adipamide (PACM6); furthermore, polyamides copolymerized with lactam components or isocyanate components such as 4,4'-diphenylmethane-diisocyanate, and polyester amide copolymers and polyether ester amide copolymers that are copolymers of copolyamides with polyesters or polyalkylene ether glycols; and copolymers thereof. These polyamides may be used alone or in combination of two or more.

[0092] Examples of the polyester include, specifically, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, a copolymer polyester having ethylene terephthalate as a main repeating unit, a copolymer polyester having butylene terephthalate as a main repeating unit, and the like. Further, examples of the copolymer polyester having ethylene terephthalate as a main repeating unit include, specifically, a copolymer polyester obtained by polymerizing ethylene isophthalate with ethylene terephthalate as a main repeating unit (hereinafter abbreviated following polyethylene(terephthalate / isophthalate)), polyethylene(terephthalate / isophthalate), polyethylene(terephthalate / adipate), polyethylene(terephthalate / sodium sulfoisophthalate), polyethylene(terephthalate / sodium isophthalate), polyethylene(terephthalate / phenyl-dicarboxylate), polyethylene(terephthalate / decanedicarboxylate), and the like. Further, examples of the copolymer polyester having butylene terephthalate as a main repeating unit include, specifically, a copolymer polyester obtained by polymerizing butylene isophthalate with butylene terephthalate as a main repeating unit (hereinafter abbreviated following polybutylene(terephthalate / isophthalate)), polybutylene(terephthalate / adipate), polybutylene(terephthalate / sebacate), polybutylene(terephthalate / decanedicarboxylate), polybutylene naphthalate, and the like. These polyesters may be used alone or in combination of two or more.

[0093] Further, the intermediate layer 11 may be formed of a nonwoven fabric made of the above resin. When the intermediate layer 11 is a nonwoven fabric, the intermediate layer 11 is preferably composed of the aforementioned polyolefin resin, polyamide resin, or the like.

[0094] The melting peak temperature of the intermediate layer 11 is preferably 110°C or higher, more preferably about 120°C or higher, still more preferably about 130°C or higher. From the same perspective, the melting peak temperature is, for example, 300°C or lower, preferably 290°C or lower, more preferably 280°C or lower, still more preferably about 275°C or lower, and even more preferably about 270°C or lower. The preferred range of the melting peak temperature includes about 110 - 300°C, about 110 - 290°C, about 110 - 280°C, about 110 - 275°C, about 110 - 270°C, about 120 - 300°C, about 120 - 290°C, about 120 - 280°C, about 120 - 275°C, about 120 - 270°C, about 130 - 300°C, about 130 - 290°C, about 130 - 280°C, about 130 - 275°C, about 130 - 270°C.

[0095] The intermediate layer 11 may be a single layer or a multilayer.

[0096] Also, by adding a colorant to the intermediate layer 11, the intermediate layer 11 can be made into a layer containing the colorant. Also, a resin with low transparency can be selected to adjust the light transmittance. When the intermediate layer 11 is a film, a colored film or a film with low transparency can also be used. Also, when the intermediate layer 11 is a non-woven fabric, a non-woven fabric using fibers or a binder containing a colorant or a non-woven fabric with low transparency can be used.

[0097] When the intermediate layer 11 is composed of a resin film, known adhesion-promoting means such as corona discharge treatment, ozone treatment, plasma treatment, etc. may be applied to the surface of the intermediate layer 11 as necessary.

[0098] From the perspective of more preferably achieving the effects of the present disclosure, the thickness of the intermediate layer 11 is preferably about 20 μm or more, more preferably about 30 μm or more, still more preferably about 40 μm or more, and is preferably about 200 μm or less, more preferably about 150 μm or less, still more preferably 100 μm or less. Preferred ranges for the thickness of the intermediate layer 11 include about 20 to 200 μm, about 20 to 150 μm, about 20 to 100 μm, about 30 to 200 μm, about 30 to 150 μm, about 30 to 100 μm, about 40 to 200 μm, about 40 to 150 μm, and about 40 to 100 μm.

[0099] From the same perspective, the ratio of the thickness of the intermediate layer 11 to the total thickness of the first resin layer 12a and the second resin layer 12b is preferably about 0.3 or more, more preferably about 0.4 or more, and is preferably about 1.0 or less, more preferably about 0.8 or less. Preferred ranges include about 0.3 to 1.0, about 0.3 to 0.8, about 0.4 to 1.0, and about 0.4 to 0.8.

[0100] Also, when the total thickness of the adhesive film 1 for metal terminals is taken as 100%, the ratio of the total thickness of the first resin layer 12a and the second resin layer 12b is preferably about 30 to 80%, more preferably about 50 to 70%.

[0101] [[ID=ID=12]]The adhesive film 1 for metal terminals of the present disclosure can be manufactured, for example, by laminating the first resin layer 12a and the second resin layer 12b on both surfaces of the intermediate layer 11, respectively. The lamination of the intermediate layer 11 with the first resin layer 12a and the second resin layer 12b can be performed by known methods such as the extrusion lamination method, the T-die method, the inflation method, and the thermal lamination method.

[0102] As a method of interposing the adhesive film 1 for metal terminals between the metal terminal 2 and the exterior material 3 for the power storage device, there are no particular restrictions. For example, as shown in FIGS. 1 to 3, the adhesive film 1 for metal terminals may be wound around the metal terminal 2 at the portion where the metal terminal 2 is sandwiched by the exterior material 3 for the power storage device. Although not shown, at the portion where the metal terminal 2 is sandwiched by the exterior material 3 for the power storage device, the adhesive film 1 for metal terminals may be disposed on both sides of the metal terminal 2 so as to cross two metal terminals 2.

[0103] The adhesion promoter layer 13 is a layer provided as necessary for the purpose of firmly adhering the intermediate layer 11 to the first resin layer 12a and the intermediate layer 11 to the second resin layer 12b (see FIG. 7). The adhesion promoter layer 13 may be provided only on one side between the intermediate layer 11 and the first resin layer 12a and the second resin layer 12b, or may be provided on both sides.

[0104] The adhesion promoter layer 13 can be formed using known adhesion promoters such as isocyanate-based, polyethyleneimine-based, polyester-based, polyurethane-based, polybutadiene-based, etc. From the viewpoint of obtaining strong adhesion strength, among these, it is preferably formed by an isocyanate-based adhesion promoter. As the isocyanate-based adhesion promoter, those composed of an isocyanate component selected from triisocyanate monomers and polymeric MDI are excellent in laminate strength and have little decrease in laminate strength at high temperatures. In particular, it is particularly preferable to form it with an adhesion promoter composed of triphenylmethane-4,4',4''-triisocyanate which is a triisocyanate monomer or polymethylene polyphenyl polyisocyanate (NCO content is about 30%, viscosity is 200 to 700 mPa·s) which is polymeric MDI. Also, it is also preferable to form it with tris(p-isocyanatophenyl) thiophosphate which is a triisocyanate monomer or a two-component curable adhesion promoter having a polyethyleneimine-based main agent and polycarbodiimide as a crosslinking agent.

[0105] The adhesion promoter layer 13 can be formed by coating and drying using a known coating method such as bar coating, roll coating, or gravure coating. The amount of the adhesion promoter to be applied is 20 to 100 mg / m when the adhesion promoter is made of triisocyanate. 2 Approximately, preferably 40 to 60 mg / m 2 In the case of adhesion promoters made of polymeric MDI, the concentration is 40 to 150 mg / m 2 Approximately, preferably 60 to 100 mg / m 2 In the case of a two-component curing adhesion promoter that uses polyethyleneimine as the main component and polycarbodiimide as the crosslinking agent, the adhesive strength is about 5 to 50 mg / m 2 about 10 to 30 mg / m 2 Triisocyanate monomer is a monomer with three isocyanate groups in one molecule, and polymeric MDI is a mixture of MDI and MDI oligomers formed by polymerizing MDI, and is represented by the following formula:

[0106] [ka]

[0107] In order to more suitably achieve the effects of the present invention, it is preferable that the first resin layer 12a and the intermediate layer 11 are in contact with each other, and that the second resin layer 12b and the intermediate layer 11 are in contact with each other.

[0108] Specific examples of preferred laminated structures for the adhesive film 1 for metal terminals of the present disclosure include a three-layer structure in which a first resin layer formed from acid-modified polypropylene / an intermediate layer (substrate) formed from polypropylene / a second resin layer formed from acid-modified polypropylene are laminated in this order; and a three-layer structure in which a first resin layer formed from acid-modified polypropylene / an intermediate layer (substrate) formed from polypropylene / a second resin layer formed from polypropylene are laminated in this order.Of these, the latter three-layer structure is particularly preferred in terms of adhesion between the heat-sealable resin layer 35 and the second resin layer 12b of the exterior material 3 for an electrical storage device.

[0109] [Metal terminal 2] The adhesive film 1 for metal terminals of the present disclosure is used by being interposed between the metal terminal 2 and the exterior material 3 for the power storage device. The metal terminal 2 (tab) is a conductive member electrically connected to the electrode (positive electrode or negative electrode) of the power storage device element 4 and is composed of a metal material. The metal material constituting the metal terminal 2 is not particularly limited, and examples thereof include aluminum, nickel, and copper. For example, the metal terminal 2 connected to the positive electrode of the lithium-ion power storage device is usually composed of aluminum or the like. Also, the metal terminal 2 connected to the negative electrode of the lithium-ion power storage device is usually composed of copper, nickel, or the like.

[0110] From the viewpoint of enhancing the electrolytic solution resistance, the surface of the metal terminal 2 is preferably subjected to a formation treatment. For example, when the metal terminal 2 is formed of aluminum, specific examples of the formation treatment include known methods for forming a corrosion-resistant film such as phosphate, chromate, fluoride, and triazine thiol compound. Among the methods for forming a corrosion-resistant film, a phosphating treatment using a composition composed of three components of a phenol resin, a chromium(III) fluoride compound, and phosphoric acid is preferable.

[0111] The size of the metal terminal 2 may be appropriately set according to the size of the power storage device to be used and the like. The thickness of the metal terminal 2 is preferably about 50 to 1000 μm, more preferably about 70 to 800 μm. Also, the length of the metal terminal 2 is preferably about 1 to 200 mm, more preferably about 3 to 150 mm. Also, the width of the metal terminal 2 is preferably about 1 to 200 mm, more preferably about 3 to 150 mm.

[0112] [Exterior material 3 for power storage device] Examples of the exterior material 3 for the power storage device include those having a laminated structure composed of a laminate having at least a base material layer 31, a barrier layer 33, and a heat-sealable resin layer 35 in this order. Fig. 8 shows an example of the cross-sectional structure of the exterior material 3 for the power storage device, in which a base material layer 31, an adhesive layer 32 provided as needed, a barrier layer 33, an adhesive layer 34 provided as needed, and a heat-sealable resin layer 35 are laminated in this order. In the exterior material 3 for the power storage device, the base material layer 31 is on the outer layer side and the heat-sealable resin layer 35 is on the innermost layer. When assembling the power storage device, the power storage device element 4 is sealed by bringing the heat-sealable resin layers 35 located at the peripheries of the power storage device elements 4 into contact with each other and heat-sealing them. Figs. 1 to 3 illustrate the power storage device 10 when using an embossed type exterior material 3 for the power storage device formed by embossing or the like, but the exterior material 3 for the power storage device may be a non-formed pouch type. Note that there are various types of pouch types, such as three-side seal, four-side seal, and pillow type, and any type may be used.

[0113] The thickness of the laminate constituting the exterior material 3 for the power storage device is not particularly limited. However, for the upper limit, from the viewpoints of cost reduction, improvement of energy density, etc., for example, it is about 190 μm or less, preferably about 180 μm or less, about 160 μm or less, about 155 μm or less, about 140 μm or less, about 130 μm or less, about 120 μm or less. For the lower limit, from the viewpoint of maintaining the function of the exterior material 3 for the power storage device to protect the power storage device element 4, preferably it is about 35 μm or more, about 45 μm or more, about 60 μm or more, about 80 μm or more. For the preferable range, for example, about 35 to 190 μm, about 35 to 180 μm, about 35 to 160 μm, about 35 to 155 μm, about 35 to 140 μm, about 35 to 130 μm, about 35 to 120 μm, about 45 to 190 μm, about 45 to 180 μm, about 45 to 160 μm, about 45 to 155 μm, about 45 to 140 μm, about 45 to 130 μm, about 45 to 120 μm, about 60 to 190 μm, about 60 to 180 μm, about 60 to 160 μm, about 60 to 155 μm, about 60 to 140 μm, about 60 to 130 μm, about 60 to 120 μm, about 80 to 190 μm, about 80 to 180 μm, about 80 to 160 μm, about 80 to 155 μm, about 80 to 140 μm, about 80 to 130 μm, about 80 to 120 μm can be mentioned.

[0114] (Base material layer 31) In the exterior material 3 for the power storage device, the base material layer 31 is a layer that functions as the base material of the exterior material for the power storage device and is the layer that forms the outermost layer side.

[0115] The material for forming the base material layer 31 is not particularly limited as long as it has insulation properties. Examples of the material for forming the base material layer 31 include polyester, polyamide, epoxy, acrylic resin, fluororesin, polyurethane, silicone resin, phenol, polyetherimide, polyimide, and mixtures or copolymers thereof. Polyesters such as polyethylene terephthalate and polybutylene terephthalate have excellent electrolyte resistance and the advantage that whitening and the like are less likely to occur due to the adhesion of the electrolyte, and are preferably used as the material for forming the base material layer 31. In addition, polyamide films have excellent stretchability and can prevent the occurrence of whitening due to resin cracking of the base material layer 31 during molding, and are preferably used as the material for forming the base material layer 31.

[0116] The base material layer 31 may be formed of a uniaxially or biaxially stretched resin film, or may be formed of an unstretched resin film. Among them, a uniaxially or biaxially stretched resin film, particularly a biaxially stretched resin film, is preferably used as the base material layer 31 because its heat resistance is improved by orientation crystallization.

[0117] Among these, preferred examples of the resin film for forming the base material layer 31 include nylon and polyester, and more preferably biaxially stretched nylon and biaxially stretched polyester.

[0118] In order to improve the pinhole resistance and insulation properties when the base material layer 31 is used as a package for a power storage device, it is also possible to laminate resin films of different materials. Specifically, examples include a multilayer structure in which a polyester film and a nylon film are laminated, and a multilayer structure in which biaxially stretched polyester and biaxially stretched nylon are laminated. When the base material layer 31 has a multilayer structure, each resin film may be adhered via an adhesive, or may be directly laminated without an adhesive. When adhering without an adhesive, for example, methods of adhering in a thermally melted state such as coextrusion method, sand lamination method, and thermal lamination method can be mentioned.

[0119] Further, the base material layer 31 may be made to have a low friction coefficient in order to improve formability. When the base material layer 31 is made to have a low friction coefficient, the friction coefficient of its surface is not particularly limited, but for example, it may be 1.0 or less. Examples of methods for reducing the friction coefficient of the base material layer 31 include matte treatment, formation of a thin film layer of a slip agent, and combinations thereof.

[0120] Regarding the thickness of the base material layer 31, for example, it may be about 10 to 50 μm, preferably about 15 to 30 μm.

[0121] (Adhesive layer 32) In the exterior material 3 for a power storage device, the adhesive layer 32 is a layer disposed on the base material layer 31 as necessary in order to impart adhesiveness to the base material layer 31. That is, the adhesive layer 32 is provided between the base material layer 31 and the barrier layer 33.

[0122] The adhesive layer 32 is formed of an adhesive that can bond the base material layer 31 and the barrier layer 33. The adhesive used for forming the adhesive layer 32 may be a two-component curable adhesive or a one-component curable adhesive. Also, the adhesion mechanism of the adhesive used for forming the adhesive layer 32 is not particularly limited, and it may be any of chemical reaction type, solvent evaporation type, hot melt type, thermocompression type, etc.

[0123] As the resin component of the adhesive that can be used for forming the adhesive layer 32, it has excellent spreadability, durability under high humidity conditions, yellowing suppression effect, heat deterioration suppression effect during heat sealing, etc., and from the viewpoint of suppressing a decrease in the laminate strength between the base material layer 31 and the barrier layer 33 and effectively suppressing the occurrence of delamination, preferably a two-component curable polyurethane-based adhesive; polyamide, polyester, or a blend resin of these and a modified polyolefin.

[0124] Further, the adhesive layer 32 may be made into multiple layers with different adhesive components. When the adhesive layer 32 is made into multiple layers with different adhesive components, from the viewpoint of improving the laminate strength between the base material layer 31 and the barrier layer 33, a resin excellent in adhesiveness to the base material layer 31 is selected as the adhesive component arranged on the base material layer 31 side, and an adhesive component excellent in adhesiveness to the barrier layer 33 is selected as the adhesive component arranged on the barrier layer 33 side. When the adhesive layer 32 is made into multiple layers with different adhesive components, specifically, as the adhesive component arranged on the barrier layer 33 side, preferably, acid-modified polyolefin, metal-modified polyolefin, a mixed resin of polyester and acid-modified polyolefin, a resin containing copolymerized polyester, etc. may be mentioned.

[0125] Regarding the thickness of the adhesive layer 32, for example, it is about 2 to 50 μm, preferably about 3 to 25 μm.

[0126] (Barrier layer 33) In the exterior material 3 for a power storage device, the barrier layer 33 is a layer having a function of preventing water vapor, oxygen, light, etc. from entering the inside of the power storage device in addition to improving the strength of the exterior material for a power storage device. The barrier layer 33 is preferably a metal layer, that is, a layer formed of a metal. Specific examples of the metal constituting the barrier layer 33 include aluminum, stainless steel, titanium, etc., and preferably aluminum. The barrier layer 33 can be formed, for example, by a metal foil, a metal vapor deposition film, an inorganic oxide vapor deposition film, a carbon-containing inorganic oxide vapor deposition film, a film provided with these vapor deposition films, etc., and it is preferably formed by a metal foil, and more preferably formed by an aluminum foil. From the viewpoint of preventing wrinkles and pinholes from occurring in the barrier layer 33 during the manufacture of the exterior material for a power storage device, the barrier layer is more preferably formed by a soft aluminum foil such as annealed aluminum (JIS H4160:1994 A8021H-O, JIS H4160:1994 A8079H-O, JIS H4000:2014 A8021P-O, JIS H4000:2014 A8079P-O).

[0127] Regarding the thickness of the barrier layer 33, from the viewpoint of thinning the exterior material for the power storage device and making it difficult for pinholes to occur during molding, it is preferably about 10 to 200 μm, more preferably about 20 to 100 μm.

[0128] In addition, for the barrier layer 33, in order to stabilize adhesion, prevent dissolution and corrosion, etc., it is preferable that at least one surface, preferably both surfaces, are subjected to a chemical conversion treatment. Here, the chemical conversion treatment refers to a treatment for forming a corrosion-resistant film on the surface of the barrier layer.

[0129] (Adhesive layer 34) In the exterior material 3 for the power storage device, the adhesive layer 34 is a layer provided between the barrier layer 33 and the heat-sealable resin layer 35 as necessary in order to firmly adhere the heat-sealable resin layer 35.

[0130] The adhesive layer 34 is formed of an adhesive capable of adhering the barrier layer 33 and the heat-sealable resin layer 35. The composition of the adhesive used for forming the adhesive layer is not particularly limited, and examples thereof include a resin composition containing an acid-modified polyolefin. Examples of the acid-modified polyolefin can be the same as those exemplified in the first resin layer 12a and the second resin layer 12b.

[0131] Regarding the thickness of the adhesive layer 34, for example, it is about 1 to 40 μm, preferably about 2 to 30 μm.

[0132] (Heat-sealable resin layer 35) In the exterior material 3 for the power storage device, the heat-sealable resin layer 35 corresponds to the innermost layer and is a layer in which the heat-sealable resin layers are heat-sealed to seal the power storage device element during the assembly of the power storage device.

[0133] The resin component used for the heat-sealable resin layer 35 is not particularly limited as long as it can be heat-sealed, and examples thereof include polyolefin and cyclic polyolefin.

[0134] Specific examples of the polyolefin include polyethylene such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene; crystalline or amorphous polypropylene 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); and terpolymers of ethylene-butene-propylene. Among these polyolefins, polyethylene and polypropylene are preferably used.

[0135] The cyclic polyolefin is a copolymer of an olefin and a cyclic monomer. Examples of the olefin that is a constituent monomer of the cyclic polyolefin include ethylene, propylene, 4-methyl-1-pentene, butadiene, isoprene, and the like. Examples of the cyclic monomer that is a constituent monomer of the cyclic polyolefin include cyclic alkenes such as norbornene; specifically, cyclic dienes such as cyclopentadiene, dicyclopentadiene, cyclohexadiene, and norbornadiene. Among these polyolefins, cyclic alkenes are preferably used, and norbornene is more preferably used. Styrene is also included as a constituent monomer.

[0136] Among these resin components, crystalline or amorphous polyolefins, cyclic polyolefins, and blend polymers thereof are preferably used; polyethylene, polypropylene, copolymers of ethylene and norbornene, and blend polymers of two or more of these are more preferably used.

[0137] The heat-sealable resin layer 35 may be formed of a single resin component alone or a blend polymer combining two or more resin components. Further, the heat-sealable resin layer 35 may be formed of only one layer, but may also be formed of two or more layers of the same or different resin components. It is particularly preferable that the resins of the second resin layer 12b and the heat-sealable resin layer 35 are common, as the adhesion between these layers is improved.

[0138] Further, the thickness of the heat-sealable resin layer 35 is not particularly limited, but is about 2 to 2000 μm, preferably about 5 to 1000 μm, and more preferably about 10 to 500 μm. Also, as the thickness of the heat-sealable resin layer 35, for example, about 100 μm or less, preferably about 85 μm or less, and more preferably about 15 to 85 μm can be mentioned. In addition, for example, when the thickness of the aforementioned adhesive layer 34 is 10 μm or more, the thickness of the heat-sealable resin layer 35 is preferably about 85 μm or less, and more preferably about 15 to 45 μm. For example, when the thickness of the adhesive layer 34 described later is less than 10 μm or when the adhesive layer 34 is not provided, the thickness of the heat-sealable resin layer 35 is preferably about 20 μm or more, and more preferably about 35 to 85 μm.

[0139] The exterior material for a power storage device of the present disclosure can also be in the form of a kit including an exterior material for a power storage device for use in a power storage device and the adhesive film for a metal terminal of the present disclosure. Also in this case, the power storage device to which it is applied includes at least a power storage device element having a positive electrode, a negative electrode, and an electrolyte, an exterior material for a power storage device that seals the power storage device element, and metal terminals that are electrically connected to the positive electrode and the negative electrode respectively and protrude outside the exterior material for a power storage device. The kit of the present disclosure is used so that the adhesive film for a metal terminal of the present disclosure is interposed between the metal terminal and the exterior material for a power storage device during use (at the time of use).

[0140] 2. Energy Storage Device The energy storage device 10 of the present disclosure includes at least an energy storage device element 4 having a positive electrode, a negative electrode, and an electrolyte, an exterior material 3 for the energy storage device that seals the energy storage device element 4, and metal terminals 2 that are electrically connected to the positive electrode and the negative electrode respectively and protrude outside the exterior material 3 for the energy storage device. In the energy storage device 10 of the present disclosure, the adhesive film 1 for the metal terminal of the present disclosure is interposed between the metal terminal 2 and the exterior material 3 for the energy storage device. That is, the energy storage device 10 of the present disclosure can be manufactured by a method including a step of interposing the adhesive film 1 for the metal terminal of the present disclosure between the metal terminal 2 and the exterior material 3 for the energy storage device.

[0141] Specifically, an energy storage device element 4 having at least a positive electrode, a negative electrode, and an electrolyte is covered with an exterior material 3 for the energy storage device with the metal terminals 2 connected to the positive electrode and the negative electrode respectively protruding outside, and the adhesive film 1 for the metal terminal of the present disclosure is interposed between the metal terminal 2 and the heat-fusible resin layer 35. The exterior material 3 for the energy storage device is used to form a flange portion (a region where the heat-fusible resin layers 35 contact each other, which is the peripheral portion 3a of the exterior material 3 for the energy storage device) of the exterior material 3 for the energy storage device around the periphery of the energy storage device element 4 so that the heat-fusible resin layers 35 of the flange portion are heat-sealed and sealed, thereby providing an energy storage device 10 using the exterior material 3 for the energy storage device. When the energy storage device element 4 is accommodated using the exterior material 3 for the energy storage device, the heat-fusible resin layer 35 of the exterior material 3 for the energy storage device is used so that it faces the inside (the surface in contact with the energy storage device element 4).

[0142] The exterior material for a power storage device of the present disclosure can be suitably used for power storage devices such as batteries (including capacitors, condensers, etc.). Further, the exterior material for a power storage device of the present disclosure can be used for either primary batteries or secondary batteries, but is preferably a secondary battery. The type of secondary battery to which the exterior material for a power storage device of the present disclosure is applied is not particularly limited. For example, lithium-ion batteries, lithium-ion polymer batteries, all-solid-state batteries, lead-acid batteries, nickel-hydrogen storage batteries, nickel-cadmium storage batteries, nickel-iron storage batteries, nickel-zinc storage batteries, silver oxide-zinc storage batteries, metal-air batteries, polyvalent cation batteries, capacitors, condensers, etc. can be mentioned. Among these secondary batteries, lithium-ion batteries and lithium-ion polymer batteries can be mentioned as suitable application targets for the exterior material for a power storage device of the present disclosure.

Examples

[0143] Examples and comparative examples are shown below to explain the present disclosure in detail. However, the present disclosure is not limited to the examples.

[0144] <Manufacture of Adhesive Film for Metal Terminals> Example 1 Using an extruder and a T-die casting device, on one side of the polypropylene as the intermediate layer (PP layer, homopolypropylene, melting peak temperature 163 °C, thickness 50 μm), maleic anhydride-modified polypropylene (PPa layer, melting peak temperature 124 °C) as the second resin layer on the exterior material side, and on the other side, as the first resin layer (resin layer A) on the metal terminal side, maleic anhydride-modified polypropylene (PPa layer, melting peak temperature 140 °C) containing 0.1% by mass of titanium nitride (average particle diameter 70 nm) was extruded at a thickness of 50 μm each, and an adhesive film (total thickness 150 μm) with the first resin layer (resin layer A containing titanium nitride, PPa layer, melting peak temperature 140 °C, thickness 50 μm) / intermediate layer (PP layer, melting peak temperature ...........

[0145] Example 2 Using an extruder and a T-die casting device, on one side of the polypropylene as the intermediate layer (PP layer, homopolypropylene, melting peak temperature 163 °C, thickness 50 μm), maleic anhydride-modified polypropylene (PPa layer, melting peak temperature 124 °C) as the second resin layer on the exterior material side, and on the other side, as the first resin layer (resin layer A) on the metal terminal side, maleic anhydride-modified polypropylene (PPa layer, melting peak temperature 140 °C) containing 1.0% by mass of titanium nitride (average particle diameter 70 nm) was extruded at a thickness of 50 μm each, and an adhesive film (total thickness 150 μm) with the first resin layer (resin layer A containing titanium nitride, PPa layer, melting peak temperature 140 °C, thickness 50 μm) / intermediate layer (PP layer, melting peak temperature 163 °C, thickness 50 μm) / second resin layer (PPa layer, melting peak temperature 124 °C, thickness 50 μm) laminated in order was obtained. The obtained adhesive film had a black appearance because the first resin layer (resin layer A) contained black titanium nitride. Note that the intermediate layer and the second resin layer are colorless and transparent.

[0146] Example 3 Using an extruder and a T-die casting device, on one side of polypropylene (PP layer, homopolypropylene, melting peak temperature 163°C, thickness 50 μm) as the intermediate layer, maleic anhydride-modified polypropylene (PPa layer, melting peak temperature 124°C) as the second resin layer on the exterior material side, and on the other side, as the first resin layer (resin layer A) on the metal terminal side, maleic anhydride-modified polypropylene (PPa layer, melting peak temperature 140°C) containing 1.0 mass% titanium nitride (average particle diameter 20 nm) was extruded with a thickness of 50 μm each, and an adhesive film (total thickness 150 μm) with the first resin layer (resin layer A containing titanium nitride, PPa layer, melting peak temperature 140°C, thickness 50 μm) / intermediate layer (PP layer, melting peak temperature 163°C, thickness 50 μm) / second resin layer (PPa layer, melting peak temperature 124°C, thickness 50 μm) laminated in sequence was obtained. The obtained adhesive film had a black appearance because the first resin layer (resin layer A) contained black titanium nitride. Note that the intermediate layer and the second resin layer were colorless and transparent.

[0147] Example 4 Using an extruder and a T-die casting device, on one side of polypropylene (PP layer, homopolypropylene, melting peak temperature 163°C, thickness 50 μm) as the intermediate layer, maleic anhydride-modified polypropylene (PPa layer, melting peak temperature 124°C) as the second resin layer on the exterior material side, and on the other side, as the first resin layer (resin layer A) on the metal terminal side, maleic anhydride-modified polypropylene (PPa layer, melting peak temperature 140°C) containing 1.0 mass% titanium nitride (average particle diameter 50 nm) was extruded with a thickness of 50 μm each, and an adhesive film (total thickness 150 μm) with the first resin layer (resin layer A containing titanium nitride, PPa layer, melting peak temperature 140°C, thickness 50 μm) / intermediate layer (substrate) (PP layer, melting peak temperature 163°C, thickness 50 μm) / second resin layer (PPa layer, melting peak temperature 124°C, thickness 50 μm) laminated in sequence was obtained. The obtained adhesive film had a black appearance because the first resin layer (resin layer A) contained black titanium nitride. Note that the intermediate layer and the second resin layer were colorless and transparent.

[0148] Example 5 Using an extruder and a T-die casting device, on one side of the polypropylene as the intermediate layer (PP layer, homopolypropylene, melting peak temperature 163 °C, thickness 50 μm), maleic anhydride-modified polypropylene (PPa layer, melting peak temperature 124 °C) as the second resin layer on the exterior material side, and on the other side, as the first resin layer (resin layer A) on the metal terminal side, maleic anhydride-modified polypropylene (PPa layer, melting peak temperature 140 °C) containing 10.0 mass% of titanium nitride (average particle diameter 70 nm) was extruded at a thickness of 50 μm each, and an adhesive film (total thickness 150 μm) with the first resin layer (resin layer A containing titanium nitride, PPa layer, melting peak temperature 140 °C, thickness 50 μm) / intermediate layer (PP layer, melting peak temperature 163 °C, thickness 50 μm) / second resin layer (PPa layer, melting peak temperature 124 °C, thickness 50 μm) laminated in order was obtained. The obtained adhesive film had a black appearance because the first resin layer (resin layer A) contained black titanium nitride. Note that the intermediate layer and the second resin layer are colorless and transparent.

[0149] Example 6 Using an extruder and a T-die casting device, on one side of the polypropylene as the intermediate layer (PP layer, homopolypropylene, melting peak temperature 163 °C, thickness 50 μm), maleic anhydride-modified polypropylene (PPa layer, melting peak temperature 124 °C) as the second resin layer on the exterior material side, and on the other side, as the first resin layer (resin layer A) on the metal terminal side, maleic anhydride-modified polypropylene (PPa layer, melting peak temperature 140 °C) containing 0.01 mass% of titanium nitride (average particle diameter 70 nm) was extruded at a thickness of 50 μm each, and an adhesive film (total thickness 150 μm) with the first resin layer (resin layer A containing titanium nitride, PPa layer, melting peak temperature 140 °C, thickness 50 μm) / intermediate layer (PP layer, melting peak temperature 163 °C, thickness 50 μm) / second resin layer (PPa layer, melting peak temperature 124 °C, thickness 50 μm) laminated in order was obtained. The obtained adhesive film had a black appearance because the first resin layer (resin layer A) contained black titanium nitride. Note that the intermediate layer and the second resin layer are colorless and transparent.

[0150] Example 7 Using an extruder and a T-die casting device, on one side of polypropylene as an intermediate layer (PP layer, homopolypropylene, melting peak temperature 163°C, thickness 50 μm), maleic anhydride-modified polypropylene (PPa layer, melting peak temperature 124°C) as the second resin layer on the exterior material side, and on the other side, maleic anhydride-modified polypropylene containing 50.0 mass% titanium nitride (average particle diameter 70 nm) (PPa layer, melting peak temperature 140°C) as the first resin layer (resin layer A) on the metal terminal side were each extruded with a thickness of 50 μm, and an adhesive film (total thickness 150 μm) with the first resin layer (resin layer A containing titanium nitride, PPa layer, melting peak temperature 140°C, thickness 50 μm) / intermediate layer (PP layer, melting peak temperature 163°C, thickness 50 μm) / second resin layer (PPa layer, melting peak temperature 124°C, thickness 50 μm) laminated in sequence was obtained. The obtained adhesive film had a black appearance because the first resin layer (resin layer A) contained black titanium nitride. Note that the intermediate layer and the second resin layer were colorless and transparent.

[0151] Example 8 Using an extruder and a T-die casting device, on one side of polypropylene containing 1.0 mass% titanium nitride (average particle diameter 95 nm) as an intermediate layer (PP layer, homopolypropylene, melting peak temperature 163°C, thickness 50 μm), maleic anhydride-modified polypropylene (PPa layer, melting peak temperature 124°C) as the second resin layer on the exterior material side, and on the other side, maleic anhydride-modified polypropylene (PPa layer, melting peak temperature 140°C) as the first resin layer (resin layer A) on the metal terminal side were each extruded with a thickness of 50 μm, and an adhesive film (total thickness 150 μm) with the second resin layer (PPa layer, melting peak temperature 140°C, thickness 50 μm) / intermediate layer containing titanium nitride (PP layer, melting peak temperature 163°C, thickness 50 μm) / second resin layer (PPa layer, melting peak temperature 124°C, thickness 50 μm) laminated in sequence was obtained. The obtained adhesive film had a black appearance because the intermediate layer (resin layer A) contained black titanium nitride. Note that the first resin layer and the second resin layer were colorless and transparent.

[0152] Comparative Example 1 Using an extruder and a T-die casting device, on one side of polypropylene (PP layer, homopolypropylene, melting peak temperature 163°C, thickness 50 μm) as the intermediate layer, maleic anhydride-modified polypropylene (PPa layer, melting peak temperature 124°C) as the second resin layer on the exterior material side, and on the other side, maleic anhydride-modified polypropylene (PPa layer, melting peak temperature 140°C) containing 0.5 mass% carbon black (average particle diameter 300 nm) as the first resin layer on the metal terminal side were each extruded with a thickness of 50 μm, and an adhesive film (total thickness 150 μm) with the first resin layer (resin layer containing carbon black, PPa layer, melting peak temperature 140°C, thickness 50 μm) / intermediate layer (PP layer, melting peak temperature 163°C, thickness 50 μm) / second resin layer (PPa layer, melting peak temperature 124°C, thickness 50 μm) laminated in sequence was obtained. The obtained adhesive film had a black appearance because the first resin layer contained black carbon black. Note that the intermediate layer and the second resin layer are colorless and transparent.

[0153] Comparative Example 2 Using an extruder and a T-die casting device, on one side of polypropylene (PP layer, homopolypropylene, melting peak temperature 163°C, thickness 50 μm) as the intermediate layer, maleic anhydride-modified polypropylene (PPa layer, melting peak temperature 124°C) as the second resin layer on the exterior material side, and on the other side, maleic anhydride-modified polypropylene (PPa layer, melting peak temperature 140°C) were each extruded with a thickness of 50 μm, and an adhesive film (total thickness 150 μm) with the first resin layer (PPa layer, melting peak temperature 140°C, thickness 50 μm) / intermediate layer (PP layer, melting peak temperature 163°C, thickness 50 μm) / second resin layer (PPa layer, melting peak temperature 124°C, thickness 50 μm) laminated in sequence was obtained. The obtained adhesive film was colorless and transparent.

[0154] Comparative Example 3 Using an extruder and a T-die casting device, on one side of polypropylene (PP layer, homopolypropylene, melting peak temperature 163°C, thickness 50 μm) as the intermediate layer, maleic anhydride-modified polypropylene (PPa layer, melting peak temperature 124°C) as the second resin layer on the exterior material side, and on the other side, maleic anhydride-modified polypropylene (PPa layer, melting peak temperature 140°C) containing 1.0 mass% of carbon black (average particle diameter 300 nm) as the first resin layer on the metal terminal side were each extruded with a thickness of 50 μm, and an adhesive film (total thickness 150 μm) with the first resin layer (resin layer containing carbon black, PPa layer, melting peak temperature 140°C, thickness 50 μm) / intermediate layer (PP layer, melting peak temperature 163°C, thickness 50 μm) / second resin layer (PPa layer, melting peak temperature 124°C, thickness 50 μm) laminated in sequence was obtained. The obtained adhesive film was colorless and transparent.

[0155] Comparative Example 4 Using an extruder and a T-die casting device, on one side of polypropylene (PP layer, homopolypropylene, melting peak temperature 163°C, thickness 50 μm) as the intermediate layer, maleic anhydride-modified polypropylene (PPa layer, melting peak temperature 124°C) as the second resin layer on the exterior material side, and on the other side, maleic anhydride-modified polypropylene (PPa layer, melting peak temperature 140°C) containing 1.0 mass% of carbon black (average particle diameter 300 nm) as the first resin layer on the metal terminal side were each extruded with a thickness of 50 μm, and an adhesive film (total thickness 150 μm) with the first resin layer (resin layer containing carbon black, PPa layer, melting peak temperature 140°C, thickness 50 μm) / intermediate layer (PP layer, melting peak temperature 163°C, thickness 50 μm) / second resin layer (PPa layer, melting peak temperature 124°C, thickness 50 μm) laminated in sequence was obtained. Since the obtained adhesive film contained black carbon black in the first resin layer, it had a black appearance. Note that the intermediate layer and the second resin layer were colorless and transparent.

[0156] The electrical resistivity of titanium nitride (titanium black) used as the insulating colorant in the examples was 15 Ω·cm, and the electrical resistivity of the carbon black used as the colorant in the comparative examples was 1 Ω·cm. The average particle diameter of the insulating colorant is the median diameter measured by a laser diffraction / scattering particle size distribution measuring device.

[0157] <Measurement of melting peak temperature> For the adhesive film, the melting peak temperature was measured in accordance with the provisions of JIS K7121:2012 (Test Method for Transition Temperature of Plastics (Addendum 1 to JIS K7121:1987)). The measurement was performed using a differential scanning calorimeter (DSC, Q200 differential scanning calorimeter manufactured by TA Instruments). The measurement sample was held at -50°C for 15 minutes, then heated from -50°C to 210°C at a heating rate of 10°C / min to measure the first melting peak temperature P (°C). After that, it was held at 210°C for 10 minutes. Next, it was cooled from 210°C to -50°C at a cooling rate of 10°C / min and held for 15 minutes. Furthermore, it was heated from -50°C to 210°C at a heating rate of 10°C / min to measure the second melting peak temperature Q (°C). The flow rate of nitrogen gas was set to 50 ml / min. By the above procedure, the melting peak temperature P (°C) measured for the first time and the melting peak temperature Q (°C) measured for the second time were obtained. By the above procedure, the value of the melting peak temperature P (°C) measured for the first time was adopted.

[0158] <Measurement of surface resistance value of adhesive film> The surface resistance value was measured for the surface on the first resin layer side of the adhesive films of the examples and comparative examples in accordance with the provisions of JIS K 7194:1994. The specific measurement method is as follows. The results are shown in Table 1. For the adhesive films of the examples and comparative examples, the surface resistance was measured under the following conditions. The ASP probe was attached to a surface resistance meter (MCP-T610: manufactured by Toyo Technica Co., Ltd.) for measurement. The adhesive film was cut to MD150 mm × TD90 mm and measured in accordance with the provisions of JIS K 7194:1994.

[0159] <The L of the adhesive film *Measurement of values> Regarding the surfaces on the first resin layer side of the adhesive films of the examples and comparative examples, respectively, under the following conditions, L * a * b * The L in the color space * value was measured. The observation conditions of the spectrophotometer (CM-700d) manufactured by Konica Minolta, calibrated with a white calibration cap (CM-A177: manufactured by Konica Minolta), were set to 10° for the observation angle, F2 for the observation light source, and the SCI mode (JIS Z8722-2009). Next, the measurement of the L * value of the surface on the first resin layer side was performed at normal temperature and normal humidity. The measurement diameter was set to 8 mmφ. The results are shown in Table 1. In Table 1, the L * value indicates the value obtained by rounding the first decimal place of the measured value.

[0160] <Evaluation of the insulation of the adhesive film> Based on the measurement results of the surface resistance values of the adhesive films in the examples and comparative examples, the insulation properties were evaluated according to the following criteria. The results are shown in Table 1. For the adhesive films in the examples and comparative examples, the insulation properties of the adhesive films obtained in the examples and comparative examples were evaluated by measuring the remaining thickness ratio of the first resin layer after heat fusion and the wire short-circuit test. The results are shown in Table 1. In the description of the sizes of the adhesive film in the form of a rectangular strip and the exterior material for the power storage device, the length and width are defined such that the length is in the MD direction and the width is in the TD direction. The exterior material for the power storage device and the adhesive film for each metal terminal were cut, and rectangular strips with a width of 40 mm and a length of 100 mm were prepared respectively. These were stacked in the order of the adhesive film for the metal terminal / the exterior material for the power storage device to obtain test sample A (laminate). On the other hand, a stainless steel wire with a diameter of 25 μm and a length of 70 mm was placed at the center in the width direction of an aluminum plate with a width of 30 mm, a length of 100 mm, and a thickness of 100 μm. Next, the first resin layer side of the adhesive film for the metal terminal of test sample A was arranged to face the wire side of the aluminum plate. At this time, the center in the width direction of test sample A was made to coincide with the center in the width direction of the aluminum plate. Next, the positive electrode of the tester was connected to the aluminum plate, and the negative electrode was connected to the test sample respectively. Regarding the negative electrode of the tester, an alligator clip was sandwiched so as to reach the barrier layer from the base material layer side of the exterior material for the power storage device of test sample A, and the negative electrode of the tester and the barrier layer were electrically connected. The tester was prepared so that a conduction (short-circuit) signal was generated when the applied voltage was 100 V and the resistance was 200 MΩ or less. Next, a voltage of 100 V was applied between the testers, and heat sealing was performed at 190 °C, 1 MPa, and a width of 7 mm so as to be orthogonal to the wire with the stainless steel wire intervening between the aluminum plate and test sample A (the width of the heat seal of 7 mm corresponds to the length direction of the wire), and the time until a short-circuit signal was generated was measured. It was measured 5 times, and the average value of 3 points excluding the longest and shortest points was taken. A: The time until short circuit is 30 seconds or more B: The time until short circuit is 20 seconds or more and less than 30 seconds C: The time until short circuit is less than 20 seconds

[0161] <Evaluation of Adhesion to Metal Terminals> The adhesion of the adhesive films of the examples and comparative examples to the metal terminals was evaluated by the following method. The results are shown in Table 1. In the description of the sizes of the rectangular strip-shaped adhesive films and the exterior materials for power storage devices, the notations of length and width define that the length is in the MD direction and the width is in the TD direction. As the metal terminal, aluminum (JIS H4160:1994 A8079H-O) with a length of 50 mm, a width of 22.5 mm, and a thickness of 0.4 mm is prepared. Also, the adhesive film for the metal terminal is cut into a length of 45 mm and a width of 10 mm. Next, the adhesive film for the metal terminal is placed on the metal terminal to obtain a laminate of the metal terminal / adhesive film. At this time, the longitudinal and transverse directions of the metal terminal coincide with the length and width directions of the adhesive film for the metal terminal, respectively, and the centers of the metal terminal and the adhesive film for the metal terminal are aligned for lamination. Also, the first resin layer of the adhesive film for the metal terminal is disposed on the metal terminal side. Next, a tetrafluoroethylene-ethylene copolymer film (ETFE film, thickness 100 μm) is placed on the adhesive film for the metal terminal of the laminate (covering the surface of the adhesive film for the metal terminal with the ETFE film), and placed on a press machine heated to 200 °C (the metal terminal is on the hot plate side), and a silicone sponge sheet is placed, and left standing at a pressure of 0.25 MPa for 16 seconds to thermally fuse the adhesive film to the metal terminal. The laminate after thermal fusion is naturally cooled to 25 °C. Next, in an environment of 25 °C, the adhesive film for the metal terminal is peeled from the metal terminal with a Tensilon universal material testing machine (for example, RTG-1210 manufactured by A&D Company). The maximum strength at the time of peeling is defined as the adhesion strength (N / 15 mm) to the metal terminal. Note that the adhesion strength is a conversion value from the measurement result at a width of 10 mm to the measurement value at a width of 15 mm. The peeling speed is 50 mm / min, the peeling angle is 180°, the distance between chucks is 30 mm, and the average value of three measurements is taken. Note that the process of standing still for 16 seconds in a heating and pressurizing environment at a temperature of 200 °C and a surface pressure of 0.25 MPa is a process assuming the heat and pressure applied in the above-mentioned temporary adhesion process and main adhesion process. (Evaluation Criteria for Adhesion) A: The adhesion strength is 40 N / 15 mm or more B: The adhesion strength is less than 40 N / 15 mm

[0162] <Evaluation of the positioning accuracy> Two pieces each of the adhesive films of the examples and comparative examples were prepared by cutting them into rectangles of 60 mm (length) × 4 mm (width). Also, one metal terminal (50 mm (length) × 3 mm (width)) made of aluminum with a thickness of 100 μm was prepared. Next, while aligning the vertical and horizontal directions so that the horizontal center of the metal terminal and the horizontal center of the adhesive film match, the metal terminal was sandwiched from both sides with two adhesive films, and heat sealing was performed with a hot plate from both sides of the two adhesive films (heat sealing conditions: temperature 190°C, surface pressure 1.0 MPa, time 3 seconds) to produce a bonded body of the metal terminal and the adhesive film. The obtained bonded body was observed, and when the length of the non-overlapping portion between the two adhesive films was within 0.1 mm, it was considered that the misalignment was easy to detect and correct, the positioning accuracy was high, and the adhesive film was properly arranged. On the other hand, when the length of the non-overlapping portion exceeded 0.1 mm, it was considered that the misalignment was difficult to detect, the positioning accuracy of the arrangement of the adhesive film was low, and misalignment had occurred. The measurement of the positioning accuracy of each adhesive film was performed 10 times and evaluated according to the following criteria. The results are shown in Table 1. In the description of the sizes of the adhesive film in the form of a rectangular strip and the exterior material for the power storage device, the description of length and width defines that the length is in the MD direction and the width is in the TD direction. A: The occurrence of misalignment is 0 times B: The occurrence of misalignment is only 1 time C: The occurrence of misalignment is 2 times or more

[0163]

Table 1

[0164] As described above, the present disclosure provides the inventions in the aspects listed below. Item 1. An adhesive film for a metal terminal interposed between a metal terminal electrically connected to an electrode of a power storage device element and an exterior material for a power storage device that seals the power storage device element, The adhesive film for metal terminals is an adhesive film for metal terminals comprising a resin layer A containing an insulating colorant. Item 2. The resin layer A has a surface resistivity measured in accordance with the provisions of JIS K 7194:1994 of 1×10 6 Ω / □ or more. The adhesive film for metal terminals according to Item 1. Item 3. The insulating colorant has an electrical resistivity of 5 Ω·cm or less. The adhesive film for metal terminals according to Item 1 or 2. Item 4. The insulating colorant has an average particle diameter of 10 nm or more and 100 nm or less. The adhesive film for metal terminals according to any one of Items 1 to 3. Item 5. The content of the insulating colorant in the resin layer A is 0.01% by mass or more and 50% by mass or less. The adhesive film for metal terminals according to any one of Items 1 to 4. Item 6. The insulating colorant is titanium nitride. The adhesive film for metal terminals according to any one of Items 1 to 5. Item 7. The resin layer A has a polyolefin backbone. The adhesive film for metal terminals according to any one of Items 1 to 6. Item 8. When the resin layer A is analyzed by infrared spectroscopy, a peak derived from maleic anhydride is detected. The adhesive film for metal terminals according to any one of Items 1 to 7. Item 9. The resin layer A is measured under the measurement conditions of the SCI method, a viewing angle of 10°, and a light source F2, and the L * a * b * value in the color space of L * is 80 or less. The adhesive film for metal terminals according to any one of Items 1 to 8. Item 10. The adhesive film for metal terminals is composed of a laminate including a first resin layer disposed on the metal terminal side, an intermediate layer, and a second resin layer disposed on the side of the exterior material for the power storage device, in this order. At least one of the first resin layer, the intermediate layer, and the second resin layer is the resin layer A. The adhesive film for metal terminals according to any one of Items 1 to 9. Item 11. The adhesive film for metal terminals according to any one of Items 1 to 10, wherein the adhesive film for metal terminals is formed of a polyolefin resin. Item 12. A method for manufacturing an adhesive film for metal terminals, which is interposed between a metal terminal electrically connected to an electrode of a power storage device element and an exterior member for a power storage device that seals the power storage device element, wherein the adhesive film for metal terminals includes a resin layer A containing an insulating colorant. Item 13. A metal terminal with an adhesive film for metal terminals, wherein the adhesive film for metal terminals according to any one of Items 1 to 11 is attached to the metal terminal. Item 14. A power storage device including at least a power storage device element having a positive electrode, a negative electrode, and an electrolyte, an exterior member for a power storage device that seals the power storage device element, and the metal terminals electrically connected to the positive electrode and the negative electrode respectively and protruding outside the exterior member for a power storage device, wherein the adhesive film for metal terminals according to any one of Items 1 to 11 is interposed between the metal terminal and the exterior member for a power storage device. Item 15. A method for manufacturing a power storage device including at least a power storage device element having a positive electrode, a negative electrode, and an electrolyte, an exterior member for a power storage device that seals the power storage device element, and the metal terminals electrically connected to the positive electrode and the negative electrode respectively and protruding outside the exterior member for a power storage device, the method including a step of interposing the adhesive film for metal terminals according to any one of Items 1 to 11 between the metal terminal and the exterior member for a power storage device and sealing the power storage device element with the exterior member for a power storage device. Item 16. An exterior member for a power storage device for use in a power storage device, The storage device includes at least a storage device element including a positive electrode, a negative electrode, and an electrolyte, an exterior material for the storage device that seals the storage device element, and metal terminals that are electrically connected to the positive electrode and the negative electrode respectively and protrude outside the exterior material for the storage device. A pressure-sensitive adhesive film for metal terminals is interposed between the metal terminals and the exterior material for the storage device. The pressure-sensitive adhesive film for metal terminals is the pressure-sensitive adhesive film for metal terminals according to any one of Items 1 to 11. The exterior material for the storage device is composed of a laminate including at least a base material layer, a barrier layer, and a heat-sealable resin layer. Item 17. A kit including an exterior material for a storage device for use in a storage device and the pressure-sensitive adhesive film for metal terminals according to any one of Items 1 to 11. The storage device includes at least a storage device element including a positive electrode, a negative electrode, and an electrolyte, an exterior material for the storage device that seals the storage device element, and metal terminals that are electrically connected to the positive electrode and the negative electrode respectively and protrude outside the exterior material for the storage device. A kit that is used such that the pressure-sensitive adhesive film for metal terminals is interposed between the metal terminals and the exterior material for the storage device during use.

Explanation of Reference Numerals

[0165] 1 Pressure-sensitive adhesive film for metal terminals 2 Metal terminals 3 Exterior material for storage device 3a Peripheral portion of the exterior material for storage device 4 Storage device element 10 Storage device 11 Intermediate layer 12a First resin layer 12b Second resin layer 31 Base material layer 32 Adhesive layer 33 Barrier layer 34 Adhesive layer 35 Heat-sealable resin layer

Claims

1. An adhesive film for a metal terminal interposed between a metal terminal electrically connected to an electrode of a power storage device element and an exterior material for a power storage device that seals the power storage device element, wherein the adhesive film for a metal terminal includes a resin layer A containing an insulating colorant, The surface resistivity of the resin layer A, measured in accordance with JIS K 7194:1994, is 1×10 6 Ω / square or more and 8.5×10 14Ω / square or less, and the insulating colorant contains titanium nitride, the adhesive film for a metal terminal has an average particle diameter of the titanium nitride of 10 nm or more and 100 nm or less.

2. The surface resistivity of the resin layer A, measured in accordance with JIS K 7194:1994, is 1×10 8 Ω / sq or more and 8.5×10 14Ω / sq or less. The adhesive film for metal terminals according to claim 1.

3. The adhesive film for a metal terminal according to claim 1 or 2, wherein the insulating colorant has an electrical resistivity of 5 Ω·cm or more.

4. The adhesive film for a metal terminal according to claim 1 or 2, wherein the insulating colorant has an average particle diameter of 10 nm or more and 100 nm or less.

5. The adhesive film for a metal terminal according to claim 1 or 2, wherein a content rate of the insulating colorant in the resin layer A is 0.01 mass% or more and 50 mass% or less.

6. The adhesive film for a metal terminal according to claim 1 or 2, wherein the insulating colorant is titanium nitride.

7. The adhesive film for a metal terminal according to claim 1 or 2, wherein the resin layer A has a polyolefin skeleton.

8. The adhesive film for a metal terminal according to claim 1 or 2, wherein when analyzed by infrared spectroscopy, a peak derived from maleic anhydride is detected.

9. The resin layer A has an L value of reflected light measured under the measurement conditions of the SCI method, a visual field of 10°, and a light source F2, which is 80 or less in the L value in the ab color space. The adhesive film for metal terminals according to claim 1 or 2. * a * b * in the ab color space * value is 80 or less. The adhesive film for metal terminals according to claim 1 or 2.

10. The adhesive film for a metal terminal is composed of a laminate including a first resin layer disposed on the metal terminal side, an intermediate layer, and a second resin layer disposed on the exterior material side for the power storage device in this order, and at least one of the first resin layer, the intermediate layer, and the second resin layer is the resin layer A.

11. The adhesive film for a metal terminal according to claim 1 or 2, which is formed of a polyolefin-based resin.

12. A method for manufacturing an adhesive film for a metal terminal interposed between a metal terminal electrically connected to an electrode of a power storage device element and an exterior material for a power storage device that seals the power storage device element, wherein the adhesive film for a metal terminal includes a resin layer A containing an insulating colorant, The surface resistivity of the resin layer A, measured in accordance with the provisions of JIS K 7194:1994, is 1×10 6 Ω / sq or more and 8.5×10 14Ω / sq or less, the insulating colorant contains titanium nitride, the method for manufacturing an adhesive film for a metal terminal has an average particle diameter of the titanium nitride of 10 nm or more and 100 nm or less.

13. A metal terminal with an adhesive film for a metal terminal according to claim 1 or 2 attached thereto.

14. A power storage device comprising at least a power storage device element including a positive electrode, a negative electrode, and an electrolyte, an exterior material for a power storage device for sealing the power storage device element, and the metal terminals electrically connected to the positive electrode and the negative electrode respectively and protruding outside the exterior material for a power storage device, A power storage device in which an adhesive film for a metal terminal according to claim 1 or 2 is interposed between the metal terminal and the exterior material for a power storage device.

15. A method for manufacturing a power storage device comprising at least a power storage device element including a positive electrode, a negative electrode, and an electrolyte, an exterior material for a power storage device for sealing the power storage device element, and the metal terminals electrically connected to the positive electrode and the negative electrode respectively and protruding outside the exterior material for a power storage device, A method for manufacturing a power storage device, comprising a step of interposing an adhesive film for a metal terminal according to claim 1 or 2 between the metal terminal and the exterior material for a power storage device and sealing the power storage device element with the exterior material for a power storage device.

16. An exterior material for a power storage device for use in a power storage device, wherein the power storage device comprises at least a power storage device element including a positive electrode, a negative electrode, and an electrolyte, an exterior material for a power storage device for sealing the power storage device element, and the metal terminals electrically connected to the positive electrode and the negative electrode respectively and protruding outside the exterior material for a power storage device, and an adhesive film for a metal terminal is interposed between the metal terminal and the exterior material for a power storage device, the adhesive film for a metal terminal is the adhesive film for a metal terminal according to claim 1 or 2, and the exterior material for a power storage device is composed of a laminate including at least a base material layer, a barrier layer, and a heat-sealable resin layer.

17. A kit including an exterior material for a power storage device for use in a power storage device and an adhesive film for a metal terminal according to claim 1 or 2. The electricity storage device includes at least an electricity storage device element including a positive electrode, a negative electrode, and an electrolyte, an exterior material for an electricity storage device that seals the electricity storage device element, and metal terminals that are electrically connected to the positive electrode and the negative electrode, respectively, and that protrude outside the exterior material for an electricity storage device, The kit is used such that, when in use, the adhesive film for a metal terminal is interposed between the metal terminal and the exterior material for an electricity storage device.

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