KR102629638B1 - Outer material for power storage device, external case for power storage device and power storage device - Google Patents

Abstract

It includes a base material layer (2) as an outer layer, a heat-sealable resin layer (3) as an inner layer, and a metal foil layer (4) between these two layers, and the heat-sealable resin layer is a first heat-sealable resin layer. The first heat-sealable water is composed of a three-layer or more laminate including the ground layer (7)/second heat-sealable resin layer (8)/third heat-sealable resin layer (9), and forms the innermost layer of the exterior material. The stratum 7 contains a propylene copolymer containing propylene as a copolymerization component, a lubricant, and incompatible particles with an average particle diameter of 0.5 to 4 μm, and the content of incompatible particles in the first heat-sealable resin layer is 1000. ∼6000 ppm, and the second heat-sealable resin layer 8 contains a propylene copolymer containing propylene as a copolymerization component and incompatible particles with an average particle diameter of 0.5 to 4 μm, and in the second heat-sealable resin layer The content of incompatible particles exceeds 0 ppm and is 100 ppm or less, and the third heat-sealable resin layer 9 is configured to contain a propylene copolymer containing propylene as a copolymerization component. With this configuration, it is possible to provide an exterior material for an electrical storage device that can ensure good moldability and suppress white turbidity.

Description

Exterior material for a power storage device, an exterior case for a power storage device, and a power storage device {OUTER MATERIAL FOR POWER STORAGE DEVICE, EXTERNAL CASE FOR POWER STORAGE DEVICE AND POWER STORAGE DEVICE}

The present invention relates to exterior materials for power storage devices, such as batteries and condensers used in portable devices such as smartphones and tablets, and batteries and condensers used for hybrid vehicles, electric vehicles, wind power generation, solar power generation, and night-time electricity storage, and the same. This relates to a power storage device externally equipped with an exterior material.

Additionally, in the scope of this specification and patent claims, the term “arithmetic mean height (Sa)” means the arithmetic mean height (Sa) measured in accordance with ISO25178.

In recent years, as mobile electric devices such as smartphones and tablet terminals have become thinner and lighter, exterior materials for electrical storage devices such as lithium-ion secondary batteries, lithium polymer secondary batteries, lithium-ion capacitors, and electric double-layer capacitors are mounted on these devices. Instead of the conventional metal can, a laminate consisting of a heat-resistant resin layer/adhesive layer/metal foil layer/adhesive layer/thermoplastic resin layer (inner sealant layer) is used. In addition, power supplies for electric vehicles, large power supplies for storage purposes, capacitors, etc. are increasingly being packaged with laminates (exterior materials) of the above configuration. By performing extrusion molding or deep drawing molding on the above-described laminate, it is molded into a three-dimensional shape such as a roughly rectangular parallelepiped shape. By molding into such a three-dimensional shape, an accommodation space for accommodating the power storage device main body can be secured.

In order to mold such a three-dimensional shape in good condition without pinholes or fractures, it is required to improve the slipperiness of the surface of the inner sealant layer. In order to improve the slipperiness of the surface of the inner sealant layer and ensure good moldability, it is known that the inner sealant layer contains an anti-blocking agent (AB agent) (see Patent Document 1).

Additionally, in order to similarly improve slipperiness and ensure good moldability, an acid resistance imparting layer is provided as an outermost layer on one side of the base layer, and a first adhesive layer is provided on the other side of the base layer. An exterior material for a lithium-ion battery in which an aluminum foil layer provided with a corrosion prevention treatment layer on at least one side, a second adhesive layer, and a sealant layer are sequentially laminated, and a slip agent (fatty acid amide, etc.) and an anti-slip agent are applied to the outer surface of the sealant layer. Exterior materials for lithium ion batteries are known in which at least one of a blocking agent (silica particles, etc.) is applied, or at least one of a slip agent (fatty acid amide, etc.) and an antiblocking agent (silica particles, etc.) are blended in the sealant layer. (See Patent Document 2).

In any of the above techniques, the slipperiness of the surface of the inner sealant layer can be improved and good moldability can be ensured.

Patent Document 1: Patent Laid-Open No. 2001-266811 Patent Document 2: Patent Laid-Open No. 2015-53289

However, if an excessive amount of an anti-blocking agent is added to the inner sealant layer in order to improve the slipperiness of the surface of the inner sealant layer, the inner sealant layer is likely to become cloudy, and the whitening of the sealant layer causes, There is a problem that even if delamination occurs between layers in the exterior material, it is easily overlooked in quality inspection.

Of course, if the amount of anti-blocking agent added is reduced, the problem of clouding of the sealant layer can be solved, but the slipperiness of the surface of the sealant layer decreases, making it impossible to perform good molding. Conventionally, it was difficult to ensure both good moldability and suppression of clouding.

In addition, in the configuration in which the sealant layer contains a slip agent (fatty acid amide, etc.), it is difficult to control the amount of surface lubricant deposited depending on the temperature holding time or storage period in the production process of the exterior material (laminated material), Although the slipperiness during molding is good, the lubricant precipitates excessively on the surface, so the lubricant adheres and deposits on the molding surface of the mold during molding of the exterior material, generating white powder (white powder caused by the lubricant). do. If such white powder adheres and accumulates on the molding surface of the mold, it becomes difficult to perform good molding, so it becomes necessary to clean and remove the white powder every time the white powder adheres and accumulates. There is a problem that the productivity of the exterior material decreases by doing this.

The present invention has been made in consideration of this technical background, and can secure good slipperiness during molding, thereby ensuring good moldability, suppressing white turbidity in the exterior material, and white powder on the surface. The purpose is to provide an exterior material for a power storage device, an exterior case for a power storage device, and a power storage device that are difficult to display.

In order to achieve the above object, the present invention provides the following means.

[1] An exterior material for an electrical storage device comprising a base layer as an outer layer, a heat-sealable resin layer as an inner layer, and a metal foil layer disposed between these two layers,

The heat-sealable resin layer includes a first heat-sealable resin layer forming the innermost layer of the exterior material, a second heat-sealable resin layer laminated on the surface of the first heat-sealable resin layer on the metal foil layer side, and , a laminate of three or more layers including a third heat-sealable resin layer laminated on the surface of the second heat-sealable resin layer on the metal foil layer side or disposed on the metal foil layer side,

The first heat-sealable resin layer contains a random copolymer containing propylene and other copolymerization components other than propylene as a copolymerization component, a lubricant, and incompatible particles with an average particle diameter of 0.5 μm to 4 μm. It consists of a first resin composition, the content of the random copolymer in the first resin composition is 50% by mass or more, and the content of the incompatible particles in the first resin composition is in the range of 1000 ppm to 6000 ppm,

The second heat-sealable resin layer is composed of a block copolymer containing propylene and other copolymerization components other than propylene as a copolymerization component, and a second resin composition containing incompatible particles with an average particle diameter of 0.5 μm to 4 μm, , the content of the block copolymer in the second resin composition is 50% by mass or more, and the content of the incompatible particles in the second resin composition exceeds 0 ppm and is 100 ppm or less,

The third heat-sealable resin layer is made of a third resin composition containing propylene as a copolymerization component and a random copolymer containing other copolymerization components other than propylene, and the random copolymer in the third resin composition An exterior material for an electrical storage device characterized by a content of 50% by mass or more.

[2] An exterior material for an electrical storage device comprising a base material layer as an outer layer, a heat-sealable resin layer as an inner layer, and a metal foil layer disposed between these two layers,

The heat-sealable resin layer includes a first heat-sealable resin layer forming the innermost layer of the exterior material, a second heat-sealable resin layer laminated on the surface of the first heat-sealable resin layer on the metal foil layer side, and , a laminate of three or more layers including a third heat-sealable resin layer laminated on the surface of the second heat-sealable resin layer on the metal foil layer side or disposed on the metal foil layer side,

The first heat-sealable resin layer is a first resin composition containing a random copolymer containing propylene and other copolymerization components other than propylene as a copolymerization component, a lubricant, and incompatible particles with an average particle diameter of 0.5 μm to 4 μm. It consists of, the content of the random copolymer in the first resin composition is 50% by mass or more, and the content of the incompatible particles in the first resin composition is in the range of 1000 ppm to 6000 ppm,

The second heat-sealable resin layer is made of a second resin composition that contains propylene as a copolymerization component and a block copolymer containing other copolymerization components other than propylene and does not contain incompatible particles, and the second resin composition The content of the block copolymer is 50% by mass or more,

The third heat-sealable resin layer is made of a third resin composition containing propylene as a copolymerization component and a random copolymer containing other copolymerization components other than propylene, and the random copolymer in the third resin composition An exterior material for an electrical storage device characterized by a content of 50% by mass or more.

[3] The electric storage device according to the preceding paragraph 1 or 2, wherein the third resin composition is a composition containing no incompatible particles, or a composition containing incompatible particles with an average particle diameter of 0.5 μm to 4 μm in an amount exceeding 0 ppm and not exceeding 6000 ppm. Exterior material for use.

[4] The exterior material for an electrical storage device according to any one of the preceding paragraphs 1 to 3, wherein the arithmetic mean height (Sa) of the inner surface of the first heat-sealable resin layer is 50 nm to 200 nm.

[5] The content of the lubricant in the first resin composition is 100 ppm to 2000 ppm, the second resin composition further contains a lubricant, and the content of the lubricant in the second resin composition is 500 ppm to 5000 ppm. The exterior material for an electrical storage device according to any one of items to 4.

[6] The heat-sealable resin layer consists of the first heat-sealable resin layer, the second heat-sealable resin layer, and the third heat-sealable resin layer, and the first heat-sealable resin layer The exterior material for an electrical storage device according to any one of the preceding paragraphs 1 to 5, wherein the thickness is 5% to 30% of the total thickness of the heat-sealable resin layer.

[7] An exterior case for an electrical storage device made of a molded body of the exterior material for an electrical storage device according to any one of the preceding paragraphs 1 to 6.

[8] It is provided with a power storage device main body and one or two types of exterior members selected from the group consisting of the exterior material for the electrical storage device according to any one of the preceding paragraph 1 to 6 and the exterior case for the electrical storage device according to the preceding paragraph 7; ,

A power storage device characterized in that the power storage device main body is externally exteriorized by the exterior member.

In the inventions [1] and [2], since the first heat-sealable resin layer forming the innermost layer of the exterior material contains the random copolymer and incompatible particles with an average particle diameter of 0.5 μm to 4 μm, the first heat-sealable resin layer forms the innermost layer of the exterior material. Appropriate irregularities can be provided to the surface (inner surface) of the inner layer, so that the contact area during molding can be reduced, and good slipperiness can be secured even with a small amount of lubricant added, thereby ensuring good moldability. By reducing the amount of lubricant to be added, the amount of lubricant bleed can be reduced, which makes it difficult for white powder to appear on the surface of the exterior material and prevents contamination from adhesion of the lubricant to the surface of the mold. can be suppressed.

In addition, in the invention of [1], the second heat-sealable resin layer has a content of incompatible particles with an average particle diameter of 0.5 ㎛ to 4 ㎛ exceeding 0 ppm and 100 ppm or less, and in the invention of [2], the content of incompatible particles (any average particle size) is greater than 0 ppm and is 100 ppm or less. Since the composition does not contain particle diameter), the occurrence of white turbidity can be prevented in this second heat-sealable resin layer (the haze rate of the second heat-sealable resin layer can be made extremely small, making it transparent) This is excellent). Therefore, the exterior material for an electrical storage device of the present invention containing such a second heat-sealable resin layer can suppress whitening, and as a result, if interlayer peeling (delamination) occurs in the exterior material, quality inspection is performed. Since it can be found in the back, the quality of the product can be significantly improved.

In addition, in the second heat-sealable resin layer, since the content of propylene as a copolymerization component and a block copolymer containing other copolymerization components other than propylene is 50% by mass or more, the heat resistance of the heat-sealable resin layer (sealant layer), In addition to improving durability, it is also possible to sufficiently prevent liquid leakage after heat sealing.

In addition, the third heat-sealable resin layer disposed on the metal foil side has a content of propylene and a random copolymer containing other copolymerization components other than propylene as a copolymerization component of 50% by mass or more, so that the third heat-sealable resin layer has adhesion with the metal foil layer. It can be improved.

In addition, the first heat-sealable resin layer forming the innermost layer of the exterior material contains propylene as a copolymerization component and a random copolymer containing other copolymerization components other than propylene at a content rate of 50% by mass or more, so it does not cause heat when sealing. The yarn temperature can be reeled (a good yarn can be achieved by yarning at a lower heat seal temperature).

In the invention of [3], the third resin composition is a composition containing incompatible particles with an average particle diameter of 0.5 μm to 4 μm in excess of 0 ppm and not more than 6000 ppm, and the adhesion with the metal foil layer can be further improved. In the configuration where the third resin composition does not contain incompatible particles, the adhesion with the metal foil layer can be further improved.

In the invention of [4], since the arithmetic mean height (Sa) of the inner surface of the first heat-sealable resin layer is 50 nm to 200 nm, slipperiness can be further improved and better moldability can be secured. In addition, clouding in the first heat-sealable resin layer can be further reduced.

In the invention of [5], the bleeding amount of the lubricant can be further suppressed while maintaining sufficient slipperiness, and contamination of the lubricant adhering to the mold surface can be further reduced.

In the invention of [6], since the thickness of the first heat-sealable resin layer is 5% to 30% of the total thickness of the heat-sealable resin layer, the metal foil side in the heat-sealable resin layer of the three-layer laminated structure The surface (the surface on the metal foil side of the third heat-sealable resin layer) becomes less susceptible to the influence of incompatible particles, and the surface on the metal foil side can be formed into a smoother surface, and when laminated (at the time of adhesion, etc.) It is possible to sufficiently prevent the mixing of air bubbles.

In the invention of [7], since the whitening of the exterior material can be suppressed, if delamination between layers (delamination) occurs in the exterior case, it can be detected in quality inspection, etc., and the quality as a product can be significantly improved. Additionally, it is possible to provide an exterior case with good molding.

In the invention of [8], a well-molded exterior case is provided, and whitening can be suppressed. Therefore, if delamination between layers occurs in the exterior case, it can be detected through quality inspection, etc. A power storage device with a high-quality exterior can be provided.

1 is a cross-sectional view showing one embodiment of an exterior material for an electrical storage device according to the present invention.
Fig. 2 is a cross-sectional view showing one embodiment of a power storage device according to the present invention.
FIG. 3 is a perspective view showing the exterior material (planar), the power storage device main body, and the exterior case (molded body molded into a three-dimensional shape) constituting the power storage device of FIG. 2 in a separated state before heat sealing.

The exterior material (1) for an electrical storage device according to the present invention includes a base material layer (2) as an outer layer, a heat-sealable resin layer (3) as an inner layer, and a metal foil layer (4) disposed between these two layers. , the heat-sealable resin layer 3 includes a first heat-sealable resin layer 7 forming the innermost layer of the exterior material 1, and the metal foil layer side of the first heat-sealable resin layer 7. A second heat-sealable resin layer (8) laminated on the surface of the second heat-sealable resin layer (8), and a third heat-sealable resin layer (8) laminated on the surface of the second heat-sealable resin layer (8) or disposed on the metal foil layer side. It is a configuration consisting of a laminated body of three or more layers including a resin layer 9 (see FIG. 1).

In the present invention, the first heat-sealable resin layer 7 is a random copolymer containing “propylene” and “other copolymerization components excluding propylene” as copolymerization components, a lubricant, and an average particle diameter of It consists of a first resin composition containing incompatible particles of 0.5 μm to 4 μm, the content of the random copolymer in the first resin composition is 50% by mass or more, and the average particle diameter in the first resin composition is The content rate of incompatible particles of 0.5 μm to 4 μm is set in the range of 1000 ppm to 6000 ppm.

In addition, the second heat-sealable resin layer 8 is composed of a block copolymer containing “propylene” and “other copolymerization components excluding propylene” as copolymerization components, and incompatible particles with an average particle diameter of 0.5 μm to 4 μm. It is made of a second resin composition containing, the content of the block copolymer in the second resin composition is 50% by mass or more, and the average particle diameter in the second resin composition is 0.5 μm to 4 μm. The content rate exceeds 0 ppm and is set to 100 ppm or less. Alternatively, the second resin composition may be configured not to contain incompatible particles of any average particle diameter.

In addition, the third heat-sealable resin layer 9 is made of a third resin composition containing a random copolymer containing “propylene” and “other copolymerization components excluding propylene” as copolymerization components, and The content of the random copolymer in the resin composition is set to 50% by mass or more.

Fig. 1 shows one embodiment of the exterior material 1 for an electrical storage device according to the present invention. The exterior material 1 for an electrical storage device of the present embodiment is laminated and integrated with the heat-sealable resin layer (inner layer) 3 on one side of the metal foil layer 4 through the inner adhesive layer 6. , the base layer (outer layer) 2 is laminated and integrated on the other side of the metal foil layer 4 through the outer adhesive layer 5. In the present embodiment shown in FIG. 1, the heat-sealable resin layer (inner layer) 3 includes a first heat-sealable resin layer constituting the innermost layer 7 of the inner layer 3; , a second heat-sealable resin layer (8) laminated on the surface of the first heat-sealable resin layer (7) on the metal foil layer (4) side, and the second heat-sealable resin layer (8). It is a three-layer laminated structure consisting of a third heat-sealable resin layer (9) laminated on the surface of the metal foil layer (4). The first heat-sealable resin layer (innermost layer) 7 is exposed on the inner surface of the exterior material 1 for an electrical storage device (see Fig. 1). In addition, one surface of the third heat-sealable resin layer 9 and the metal foil layer 4 is bonded and integrated with the inner adhesive layer 6 (see Fig. 1).

The exterior material 1 for an electrical storage device of this embodiment shown in FIG. 1 is used for a lithium ion secondary battery case. The exterior material 1 for an electrical storage device can be used for molding, such as deep drawing molding or expansion molding, for example, as a case for a secondary battery.

In the present invention, the heat-sealable resin layer (inner layer; sealant layer) 3 has excellent chemical resistance even against highly corrosive electrolytes used in lithium-ion secondary batteries, etc., and is heat-sealable to the exterior material. It is responsible for granting .

The first heat-sealable resin layer (7) and the third heat-sealable resin layer (9) both contain a random copolymer containing “propylene” and “other copolymerization components excluding propylene” as copolymerization components. do. Regarding the random copolymer, the “other copolymerization components other than propylene” are not particularly limited, but include, for example, ethylene, 1-butene, 1-hexene, 1-pentene, 4methyl-1-pentene, etc. In addition to the olefin component, butadiene and the like can be mentioned.

The second heat-sealable resin layer 8 contains a block copolymer containing “propylene” and “other copolymerization components excluding propylene” as copolymerization components. Regarding the block copolymer, the "other copolymerization components other than propylene" are not particularly limited, but include, for example, ethylene, 1-butene, 1-hexene, 1-pentene, 4methyl-1-pentene, etc. In addition to the olefin component, butadiene and the like can be mentioned.

In the present invention, the incompatible particles include the first heat-sealable resin layer (7), the second heat-sealable resin layer (8), the third heat-sealable resin layer (9), etc. to which it is added. There is no particular limitation as long as the particles are incompatible with the resin (copolymer) constituting the . Among these, it is preferable to use an anti-blocking agent (AB agent) as the incompatible particles.

The anti-blocking agent is not particularly limited, but examples include inorganic particles and resin particles. The inorganic particles are not particularly limited, but examples include inorganic oxide particles (silica particles, alumina particles, titanium oxide particles, etc.), inorganic carbonate particles (calcium carbonate particles, barium carbonate particles, etc.), and inorganic silicate particles (silicic acid). aluminum particles, talc particles, kaolin particles, etc.). The resin particles are not particularly limited, but examples include acrylic resin particles, polyolefin resin particles (polyethylene resin particles, polypropylene resin particles), and polystyrene resin particles.

As the above-mentioned incompatible particles, only one type may be used, or two or more types may be used in combination. When two or more types are used together, it is preferable to use two or more types of incompatible particles with different average particle diameters, and in this case, the surface (inner surface) 7a of the innermost layer (first heat-sealable resin layer) 7 The effect of uniform distribution of overall roughness can be obtained. Additionally, it is preferable to use the incompatible particles having a specific gravity of 3 or less, and in this case, the effect of being able to uniformly disperse the incompatible particles within the layer can be obtained.

As the incompatible particles, incompatible particles with an average particle diameter of 0.5 μm to 4 μm are used. If incompatible particles with an average particle diameter of less than 0.5㎛ are used, the surface irregularities necessary to prevent blocking of the exterior material cannot be formed well, and if incompatible particles with an average particle diameter of 4㎛ or more are used, the incompatible particles may cause adhesion to the mold or form. A problem arises in which non-commercial particles fall off. As the incompatible particles, it is preferable to use incompatible particles with an average particle diameter of 0.7 μm to 2.5 μm.

The content rate (concentration) of “incompatible particles with an average particle diameter of 0.5 μm to 4 μm” in the first heat-sealable resin layer 7 is set in the range of 1000 ppm to 6000 ppm. If it is less than 1000ppm, it becomes difficult to form irregularities over the entire surface (inner surface) 7a of the innermost layer (first heat-sealable resin layer) 7, and if it exceeds 6000ppm, the first heat-sealable resin layer ( The degree of whitening in 7) increases, and problems such as insufficient heat sealing or falling off of non-commercial particles arise. The content rate (concentration) of “incompatible particles with an average particle diameter of 0.5 μm to 4 μm” in the first heat-sealable resin layer 7 is preferably set in the range of 2000 ppm to 5000 ppm.

The content rate (concentration) of “incompatible particles with an average particle diameter of 0.5 μm to 4 μm” in the second heat-sealable resin layer 8 is set to exceed 0 ppm and be set to 100 ppm or less, or, The second heat-sealable resin layer 8 is configured to not contain incompatible particles (regardless of average particle diameter). By adopting such a configuration, clouding of the second heat-sealable resin layer 8 can be prevented. That is, if the content exceeds 100 ppm, even if delamination (peeling) occurs between the metal foil layer 4 and the heat-sealable resin layer 3, it cannot be detected in quality inspection or the like, or it becomes difficult to detect.

The third heat-sealable resin layer 9 preferably has a composition containing incompatible particles with an average particle diameter of 0.5 μm to 4 μm in an amount exceeding 0 ppm and not exceeding 6000 ppm. When such a configuration is adopted, the adhesion with the metal foil layer 4 can be further improved, whitening of the third heat-sealable resin layer 9 can be suppressed, and the metal foil layer 4 and If delamination (peeling) occurs between the heat-sealable resin layers 3, it can be detected during quality inspection, etc. Alternatively, the third heat-sealable resin layer 9 is preferably made of a composition that does not contain incompatible particles (regardless of the average particle diameter), and in this case, the adhesion with the metal foil layer 4 is further improved. Since the third heat-sealable resin layer 9 does not become cloudy and delamination occurs between the metal foil layer 4 and the heat-sealable resin layer 3, quality inspection can be performed. It can be easily found in etc.

In the case of employing the three-layer lamination structure of FIG. 1 as the heat-sealable resin layer 3, the ratio of the thickness of the three layers is the thickness of the first heat-sealable resin layer 7/second heat-sealability. Thickness of the resin layer 8/thickness of the third heat-sealable resin layer 9 = preferably set in the range of 5 to 20/90 to 60/5 to 20.

In the present invention, the lubricant is not particularly limited, but fatty acid amide is suitably used. The fatty acid amide is not particularly limited, but includes, for example, saturated fatty acid amide, unsaturated fatty acid amide, substituted amide, methylolamide, saturated fatty acid bisamide, unsaturated fatty acid bisamide, fatty acid ester amide, aromatic bisamide, etc. I can hear it.

The saturated fatty acid amide is not particularly limited, but examples include lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, and hydroxystearic acid amide. The unsaturated fatty acid amide is not particularly limited, but examples include oleic acid amide and erucic acid amide.

The substituted amides are not particularly limited, but include, for example, N-oleyl palmitate amide, N-stearyl stearic acid amide, N-stearyl oleic acid amide, N-oleyl stearic acid amide, and N-stearyl erucic acid. Amides, etc. can be mentioned. In addition, the methylolamide is not particularly limited, but examples include methylolstearic acid amide.

The saturated fatty acid bisamide is not particularly limited, but includes, for example, methylenebisstearic acid amide, ethylenebiscapric acid amide, ethylenebislauric acid amide, ethylenebisstearic acid amide, ethylenebishydroxystearic acid amide, and ethylenebisbe. Hexane amide, hexamethylenebisstearic acid amide, hexamethylenebisbehenic acid amide, hexamethylene hydroxystearic acid amide, N,N'-distearyladipic acid amide, N,N'-distearylsebacic acid amide, etc. there is.

The unsaturated fatty acid bisamide is not particularly limited, but examples include ethylenebisoleic acid amide, ethylenebisoleic acid amide, hexamethylenebisoleic acid amide, and N,N'-dioleylsebacic acid amide. .

The fatty acid esteramide is not particularly limited, but examples include stearamidoethyl stearate. The aromatic bisamide is not particularly limited, but examples include m-xylenebisstearic acid amide, m-xylenebishydroxystearic acid amide, and N,N'-cystearyl isophthalic acid amide.

The content of the lubricant in the first heat-sealable resin layer 7 is preferably set to 100 ppm to 2000 ppm. When it is 100 ppm or more, the lubricant in the first heat-sealable resin layer 7 is appropriately precipitated on the surface 7a to further improve slipperiness, and when it is 2000 ppm or less, the lubricant is excessively precipitated on the surface 7a. Since there is nothing to do, it becomes more difficult for white powder to appear on the surface 7a. Among these, the content of the lubricant in the first heat-sealable resin layer 7 is more preferably set to 100 ppm to 1000 ppm.

It is preferable that the second heat-sealable resin layer 8 contains a lubricant. The lubricant content in the second heat-sealable resin layer 8 is preferably set to 500 ppm to 5000 ppm. When it is 500ppm or more, the lubricant present in the first heat-sealable resin layer 7 penetrates into the second heat-sealable resin layer 8, resulting in a deficiency state of the lubricant in the first heat-sealable resin layer 7. can be prevented, and by being less than 5000ppm, it is possible to prevent white dust contamination of the surface of the exterior material or white dust contamination of peripheral devices due to bleed-out lubricant.

In addition, it is preferable to include a lubricant in the third heat-sealable resin layer 9, but since there is a risk that the laminate strength may decrease, the third heat-sealable resin layer 9 should contain a lubricant exceeding 0 ppm. It is desirable to contain 250 ppm or less. Of course, the third heat-sealable resin layer 9 may be configured not to contain a lubricant.

In the present invention, the thickness of the first heat-sealable resin layer (7) is preferably set to 5% to 30% of the total thickness of the heat-sealable resin layer (3). By setting it to 5% or more, sufficient surface roughness can be obtained to improve slipperiness, and sufficient yarn strength can be secured for heat application. In addition, by setting it to 30% or less, the durability of the heat-sealable resin layer 3 after heat sealing can be further improved, and the surface of the metal foil side of the heat-sealable resin layer 3 is free from the influence of incompatible particles. It becomes difficult to receive pressure, and the surface on the metal foil side can be formed into a smoother surface, and the mixing of air bubbles can be sufficiently prevented during lamination (during adhesion, etc.). Among these, it is particularly preferable that the thickness of the first heat-sealable resin layer 7 is set to 10% to 20% of the total thickness of the heat-sealable resin layer 3.

In the present invention, a part of the lubricant is exposed (bleeded) and adheres to the surface 7a of the innermost layer (first heat-sealable resin layer) 7 of the heat-sealable resin layer 3, The adhesion amount of the lubricant on the surface 7a of the innermost layer (first heat-sealable resin layer) 7 is preferably in the range of 0.1 μg/cm2 to 1.0 μg/cm2.

In addition, in the embodiment shown in FIG. 1, the heat-sealable resin layer (inner layer) 3 is a first heat-sealable resin layer/second heat-sealable layer constituting the innermost layer 7 of the exterior material 1. Although a three-layer lamination structure of the heat-sealable resin layer (8)/third heat-sealable resin layer (9) is adopted, it is not particularly limited to this structure, and the second heat-sealable resin layer (8) and the third heat-sealable resin layer (9) are adopted. 3. A configuration in which “another heat-sealable resin layer” is stacked in one to multiple layers between the heat-sealable resin layers 9 may be adopted. In other words, “…” defined as the invention in [1] and [2] above. In the second heat-sealable resin layer 8... (about)… The term “disposed on the metal foil layer side” in “consisting of a laminate of three or more layers including the third heat-sealable resin layer (9) disposed on the metal foil layer side ” refers to the second heat-sealable resin layer (8) It defines a configuration in which one to multiple layers of other heat-sealable resin layers are stacked between the third heat-sealable resin layer 9. In addition, as the "other heat-sealable resin layer", for example, the random copolymer (random copolymer containing propylene and other copolymerization components other than propylene as a copolymerization component) in which the elastomer component and the amount of lubricant are changed, Examples include the above-described block copolymers (block copolymers containing propylene and other copolymerization components other than propylene as copolymerization components) with different elastomer components or lubricant amounts, and homopolypropylene resin.

In the present invention, the base layer (outer layer) 2 is preferably formed of a heat-resistant resin layer. As the heat-resistant resin constituting the heat-resistant resin layer 2, a heat-resistant resin that does not melt at the heat-sealing temperature used when heat-sealing the exterior material 1 is used. As the heat-resistant resin, it is preferable to use a heat-resistant resin having a melting point of at least 10° C. higher than the melting point of the heat-sealable resin layer 3 (the melting point of the layer with the highest melting point among the first to third heat-sealable resin layers). It is particularly preferable to use a heat-resistant resin having a melting point of the heat-sealable resin layer 3 (20°C or more higher than the melting point of the layer with the highest melting point among the first to third heat-sealable resin layers).

The heat-resistant resin layer (outer layer) 2 is not particularly limited, but examples include polyamide films such as nylon films, polyester films, etc., and stretched films thereof are preferably used. Among them, the heat-resistant resin layer 2 may be a biaxially stretched polyamide film such as a biaxially stretched nylon film, a biaxially stretched polybutylene terephthalate (PBT) film, a biaxially stretched polyethylene terephthalate (PET) film, or It is particularly preferred to use biaxially oriented polyethylene naphthalate (PEN) film. The nylon film is not particularly limited, but examples include 6 nylon film, 6,6 nylon film, and MXD nylon film. In addition, the heat-resistant resin layer 2 may be formed as a single layer, or may be formed as a multi-layer, for example, made of polyester film/polyamide film (multi-layer made of PET film/nylon film, etc.).

The thickness of the heat-resistant resin layer (outer layer) 2 is preferably 2 μm to 50 μm. When using a polyester film, the thickness is preferably 2㎛ to 50㎛, and when using a nylon film, the thickness is preferably 7㎛ to 50㎛. By setting it above the appropriate lower limit, sufficient strength as a packaging material can be secured, and by setting it below the appropriate upper limit, stress during molding such as extrusion molding and drawing can be reduced, and formability can be improved.

The metal foil layer 4 serves to provide a gas barrier property that prevents oxygen or moisture from entering the exterior material 1. The metal foil layer 4 is not particularly limited, but examples include aluminum foil, SUS foil (stainless steel foil), Cu foil, Ni foil, and Ti foil, and among them, aluminum foil. , it is preferable to use SUS foil (stainless steel foil). The thickness of the metal foil layer 4 is preferably 5 μm to 120 μm. By being 5㎛ or more, it is possible to prevent the occurrence of pinholes during rolling when manufacturing metal foil, and by being 120㎛ or less, the stress during molding such as extrusion molding and drawing can be reduced, thereby improving formability. there is. Among these, it is more preferable that the thickness of the metal foil layer 4 is 10 μm to 80 μm.

The metal foil layer 4 is preferably subjected to chemical conversion treatment on at least the inner surface (the surface on the inner layer 3 side). By performing such a chemical treatment, it is possible to sufficiently prevent corrosion of the metal foil surface caused by the contents (electrolyte solution of the battery, etc.). For example, chemical conversion treatment is performed on the metal foil by performing the following treatment. That is, for example, on the surface of a metal foil that has been degreased,

1) Phosphoric acid,

Chromic acid,

An aqueous solution of a mixture containing at least one compound selected from the group consisting of metal salts of fluoride and non-metal salts of fluoride.

2) phosphoric acid,

At least one resin selected from the group consisting of acrylic resin, chitosan derivative resin, and phenolic resin,

An aqueous solution of a mixture containing at least one compound selected from the group consisting of chromic acid and chromium (III) salts

3) phosphoric acid,

At least one resin selected from the group consisting of acrylic resin, chitosan derivative resin, and phenolic resin,

At least one compound selected from the group consisting of chromic acid and chromium (III) salts,

An aqueous solution of a mixture containing at least one compound selected from the group consisting of metal salts of fluoride and non-metal salts of fluoride.

After applying any of the aqueous solutions of 1) to 3) above, chemical conversion treatment is performed by drying.

The amount of chromium adhesion (per side) of the chemical conversion film is preferably 0.1 mg/m2 to 50 mg/m2, and particularly preferably 2 mg/m2 to 20 mg/m2.

The outer adhesive 5 is not particularly limited, but examples include thermosetting adhesive. The thermosetting adhesive is not particularly limited, but examples include olefin adhesives, epoxy adhesives, and acrylic adhesives. The thickness of the outer adhesive layer 5 is preferably set to 1 μm to 5 μm. Among these, from the viewpoint of thinning and weight reduction of the packaging material 1, it is particularly preferable that the thickness of the outer adhesive layer 5 is set to 1 μm to 3 μm.

The inner adhesive 6 is not particularly limited, but examples include the thermosetting adhesive. The thickness of the inner adhesive layer 6 is preferably set to 1 μm to 5 μm. Among these, from the viewpoint of thinning and weight reduction of the packaging material 1, it is particularly preferable that the thickness of the inner adhesive layer 6 is set to 1 μm to 3 μm.

Among the base layer (2) and heat-sealable resin layer (3) (including the innermost layer (7)) constituting the exterior material (1) for an electrical storage device, the following are included in the range that does not impair the effect of the present invention: The same additives may be added. The additives are not particularly limited, but include, for example, antioxidants, plasticizers, ultraviolet absorbers, anti-fungal agents, colorants (pigments, dyes, etc.), antistatic agents, rust inhibitors, moisture absorbents, oxygen absorbers, etc. The plasticizer is not particularly limited, but includes, for example, glycerol fatty acid ester monoglyceride, glycerol fatty acid ester acetylated monoglyceride, glycerol fatty acid ester organic acid monoglyceride, glycerol fatty acid ester chain fatty acid triglyceride, Examples include polyglycerin fatty acid ester, sorbitan fatty acid ester, propylene glycol fatty acid ester, special fatty acid ester, and higher alcohol fatty acid ester.

By molding (deep drawing molding, expansion molding, etc.) the exterior material 1 for an electrical storage device of the present invention, an exterior case (battery case, etc.) 10 can be obtained (see Fig. 3). Additionally, the exterior material 1 of the present invention can be used as is without being subjected to molding (see Fig. 3).

One embodiment of a power storage device 30 constructed using the exterior material 1 for a power storage device of the present invention is shown in FIG. 2 . This electrical storage device 30 is a lithium ion secondary battery. In this embodiment, as shown in FIGS. 2 and 3, the exterior member 15 is comprised of an exterior case 10 obtained by molding the exterior material 1 and the planar exterior material 1. However, a generally rectangular parallelepiped-shaped power storage device body portion (electrochemical element, etc.) 31 is accommodated in the receiving concave portion of the exterior case 10 obtained by molding the exterior material 1 of the present invention, and the power storage device body portion On top of (31), the exterior material 1 of the present invention is disposed with the heat-sealable resin layer 3 side inward (lower side) without being molded, and the heat-sealable water of the planar exterior material 1 is The peripheral portion of the ground layer 3 (first heat-sealable resin layer 7) and the heat-sealable resin layer 3 (first row) of the flange portion (peripheral portion for sealing) 29 of the exterior case 10. The electrical storage device 30 of the present invention is configured by sealing the fusible resin layer 7 by heat sealing (see Figs. 2 and 3). In addition, the inner surface of the receiving recess of the exterior case 10 is made of a heat-sealable resin layer 3 (first heat-sealable resin layer 7), and the outer surface of the receiving recess is a base material layer (outer side). layer) (2) (see Figure 3).

In FIG. 2, 39 is a heat seal portion where the peripheral portion of the exterior material 1 and the flange portion (peripheral portion for sealing) 29 of the exterior case 10 are joined (welded). In addition, in the power storage device 30, the tip of the tab lead connected to the power storage device main body 31 extends outside the exterior member 15, but is not shown in the illustration.

The electrical storage device main body 31 is not particularly limited, but examples include a battery main body, a capacitor main body, and a condenser main body. The width of the heat seal portion 39 is preferably set to 0.5 mm or more. By setting it to 0.5 mm or more, sealing can be performed reliably. Among these, the width of the heat seal portion 39 is preferably set to 3 mm to 15 mm.

In addition, in the above embodiment, the exterior member 15 was composed of an exterior case 10 obtained by molding the exterior material 1 and a planar exterior material 1 (see FIGS. 2 and 3), especially in this case. It is not limited to combinations, and for example, the exterior member 15 may be composed of a pair of planar exterior materials 1, or may be composed of a pair of exterior cases 10.

[Example]

Next, specific examples of the present invention will be described, but the present invention is not particularly limited to these examples.

<Example 1>

A chemical treatment solution consisting of phosphoric acid, polyacrylic acid (acrylic resin), chromium (Ⅲ) salt compound, water, and alcohol is applied to both sides of the aluminum foil (4) with a thickness of 35㎛, and then dried at 180°C. This was performed to form a chemical conversion film. The chromium adhesion amount of this chemical conversion film is 10 mg/m2 per side.

Next, a biaxially stretched 6-nylon film (2) with a thickness of 5 μm was dry laminated (joined) to one side of the chemically treated aluminum foil (4) using a two-component curing type urethane-based adhesive (5). .

Next, a first heat-sealable resin unstretched film with a thickness of 4.5 ㎛ containing an ethylene-propylene random copolymer, 1000 ppm of erucic acid amide (lubricant), and 2000 ppm of silica particles (average particle diameter 1.0 ㎛; incompatible particles). (7), a second non-stretched heat-sealable resin with a thickness of 21 ㎛ containing an ethylene-propylene block copolymer, 1000 ppm of erucic acid amide (lubricant), and 50 ppm of silica particles (average particle diameter 1.0 ㎛; incompatible particles) Film (8), a third heat-sealable resin lead-free with a thickness of 4.5 ㎛, containing an ethylene-propylene random copolymer, 1000 ppm of erucic acid amide (lubricant), and 2000 ppm of silica particles (average particle diameter 1.0 ㎛; incompatible particles). The new film 9 is co-extruded using a T-die so that three layers are stacked in this order, resulting in a 30-μm-thick sealant film formed by stacking these three layers (first heat-sealable resin non-stretched film layer 7). / After obtaining the second heat-sealable resin non-stretched film layer (8) / the third heat-sealable resin non-stretched film layer (9)) (3), the third heat-sealable resin non-lead film layer (3) of the sealant film (3) is obtained. The side of the fresh film layer (9) is overlapped with the other side of the dry laminated aluminum foil (4) through a two-component curing type maleic acid-modified polypropylene adhesive (6) and heated at 100°C with a rubber nip roll. It is dry laminated by sandwiching it between heated laminate rolls and pressing it, winding it around the roll shaft, and then aging (heating) at 40°C for 10 days and then pulling it out from the roll shaft, as shown in Figure 1. An exterior material (1) for an electrical storage device having the following configuration was obtained.

In addition, the two-component curing type maleic acid-modified polypropylene adhesive includes 100 parts by mass of maleic acid-modified polypropylene (melting point 80°C, acid value 10 mgKOH/g) as the main agent, and the isocyanurate form of hexamethylene diisocyanate as the curing agent. (NCO content: 20% by mass) 8 parts by mass, and using an adhesive solution mixed with a solvent, apply the adhesive solution to the other side of the aluminum foil 4 so that the solid content application amount is 2g/m2. was applied, heated and dried, and then overlapped with the third unstretched film layer 9 of the sealant film 3.

<Example 2>

In the same manner as in Example 1, except that the content rate of silica particles (emergency particles) in the first heat-sealable resin layer (innermost layer) 7 and the third heat-sealable resin layer 9 was changed from 2000 ppm to 1000 ppm. , the exterior material 1 for an electrical storage device having the structure shown in FIG. 1 was obtained.

<Example 3>

In the same manner as in Example 1, except that the content rate of silica particles (emergency particles) in the first heat-sealable resin layer (innermost layer) 7 and the third heat-sealable resin layer 9 was changed from 2000 ppm to 6000 ppm. , the exterior material 1 for an electrical storage device having the structure shown in FIG. 1 was obtained.

<Example 4>

As incompatible particles, silica particles with an average particle diameter of 3.0 μm were used instead of silica particles with an average particle diameter of 1.0 μm, and in the same manner as in Example 1, an exterior material for an electrical storage device (1) having the structure shown in FIG. 1 was obtained. .

<Example 5>

As incompatible particles, silica particles with an average particle diameter of 4.0 μm were used instead of silica particles with an average particle diameter of 1.0 μm, and in the same manner as in Example 1, an exterior material for an electrical storage device (1) having the structure shown in FIG. 1 was obtained. .

<Example 6>

As incompatible particles, silica particles with an average particle diameter of 0.5 μm were used instead of silica particles with an average particle diameter of 1.0 μm, and in the same manner as in Example 1, an exterior material for an electrical storage device (1) having the structure shown in FIG. 1 was obtained. .

<Example 7>

Except that the erucic acid amide content rate in the second heat-sealable resin layer 8 was changed from 1000 ppm to 6000 ppm, the same procedure as in Example 1 was performed to obtain an exterior material 1 for an electrical storage device having the structure shown in FIG. 1 .

<Example 8>

Except that the erucic acid amide content rate of 1000 ppm in the second heat-sealable resin layer 8 was changed to 400 ppm, the same procedure as in Example 1 was performed to obtain an exterior material 1 for an electrical storage device having the structure shown in FIG. 1 .

<Example 9>

Except that the erucic acid amide content rate of 1000 ppm in the first heat-sealable resin layer 7 and the third heat-sealable resin layer 9 was changed to 3000 ppm, the configuration is similar to Example 1, and is shown in FIG. The exterior material (1) for an electrical storage device was obtained.

<Example 10>

Except that the erucic acid amide content rate of 1000 ppm in the first heat-sealable resin layer 7 and the third heat-sealable resin layer 9 was changed to 50 ppm, the configuration is similar to Example 1, and is shown in FIG. The exterior material (1) for an electrical storage device was obtained.

<Example 11>

In the same manner as in Example 1, except that the thickness of the first heat-sealable resin layer 7 was changed to 1.0 μm and the thickness of the third heat-sealable resin layer 9 was changed to 4.5 μm to 8.0 μm. , the exterior material 1 for an electrical storage device having the structure shown in FIG. 1 was obtained.

<Example 12>

The thickness of the first heat-sealable resin layer 7 is changed to 10 μm, the thickness of the second heat-sealable resin layer 8 is changed to 21 μm, and the third heat-sealable resin layer (8) is changed to 16 μm. Except that the thickness of 9) was changed from 4.5 μm to 4.0 μm, the same procedure as in Example 1 was performed to obtain the exterior material 1 for an electrical storage device having the structure shown in FIG. 1 .

<Example 13>

An exterior material (1) for an electrical storage device having the configuration shown in FIG. 1 in the same manner as in Example 1, except that the content of silica particles (non-use particles) in the second heat-sealable resin layer (8) was changed from 50 ppm to 75 ppm. got it

<Example 14>

An exterior material 1 for an electrical storage device having the configuration shown in FIG. 1 in the same manner as in Example 1, except that the content of silica particles (non-use particles) in the second heat-sealable resin layer 8 was changed from 50 ppm to 25 ppm. got it

<Example 15>

Except that the content of silica particles (non-use particles) in the second heat-sealable resin layer 8 was changed from 50 ppm to 0 ppm (no emergency particles were contained), the same procedure as in Example 1 was shown in FIG. 1. The exterior material (1) for an electrical storage device was obtained.

<Example 16>

As incompatible particles, silica particles with an average particle diameter of 2.0 μm were used instead of silica particles with an average particle diameter of 1.0 μm, and in the same manner as in Example 1, an exterior material for an electrical storage device (1) having the structure shown in FIG. 1 was obtained. .

<Example 17>

As incompatible particles, barium carbonate particles with an average particle diameter of 1.0 μm were used instead of silica particles with an average particle diameter of 1.0 μm, and the exterior material 1 for an electrical storage device having the structure shown in FIG. 1 was prepared in the same manner as in Example 1. got it

<Example 18>

As incompatible particles, acrylic resin beads (particles) with an average particle diameter of 1.0 μm were used instead of silica particles with an average particle diameter of 1.0 μm, in the same manner as in Example 1, and an exterior material for an electrical storage device having the structure shown in FIG. 1 ( 1) was obtained.

<Example 19>

As a lubricant, behenic acid amide was used instead of erucic acid amide in the same manner as in Example 1, and an exterior material 1 for an electrical storage device having the structure shown in FIG. 1 was obtained.

<Example 20>

Except that the content of silica particles (non-use particles) in the third heat-sealable resin layer 9 was changed from 2000 ppm to 50 ppm, in the same manner as in Example 1, an exterior material for an electrical storage device (1) having the structure shown in FIG. got it

<Example 21>

Except that the content of silica particles (emergency particles) in the third heat-sealable resin layer 9 was changed from 2000 ppm to 0 ppm (emergency particles were not contained), the same procedure as in Example 1 was shown in FIG. 1. The exterior material (1) for an electrical storage device was obtained.

<Comparative example 1>

An exterior material for an electrical storage device was obtained in the same manner as in Example 1, except that the content of 50 ppm of silica particles (non-use particles) in the second heat-sealable resin layer 8 was changed to 150 ppm.

<Comparative example 2>

An exterior material for an electrical storage device was obtained in the same manner as in Example 1, except that the content of silica particles (non-use particles) in the first heat-sealable resin layer (innermost layer) 7 was changed from 2000 ppm to 800 ppm.

<Comparative example 3>

An exterior material for an electrical storage device was obtained in the same manner as in Example 1, except that the content of silica particles (non-use particles) in the first heat-sealable resin layer (innermost layer) 7 was changed from 2000 ppm to 6500 ppm.

<Comparative example 4>

The sealant film (3) is a lead-free, heat-sealable resin with a thickness of 30 μm containing an ethylene-propylene random copolymer, 1000 ppm of erucic acid amide (lubricant), and 2000 ppm of silica particles (average particle diameter 1.0 μm; incompatible particles). An exterior material for an electrical storage device was obtained in the same manner as in Example 1, except that a new film (single layer) was used.

<Comparative example 5>

The sealant film (3) is a lead-free, heat-sealable resin with a thickness of 30 μm containing an ethylene-propylene block copolymer, 1000 ppm of erucic acid amide (lubricant), and 50 ppm of silica particles (average particle diameter: 1.0 μm; incompatible particles). An exterior material for an electrical storage device was obtained in the same manner as in Example 1, except that a new film (single layer) was used.

<Comparative Example 6>

The thickness of the first heat-sealable resin layer 7 is changed to 10 μm, the thickness of the second heat-sealable resin layer 7 is changed to 10 μm, and the thickness of the second heat-sealable resin layer 8 is changed to 10 μm, and the third heat-sealable resin layer ( 9), the thickness of 4.5 μm was changed to 10 μm, and as the resin constituting the second heat-sealable resin layer 8, ethylene-propylene random copolymer was used instead of ethylene-propylene block copolymer. In the same manner as in Example 1, an exterior material for an electrical storage device was obtained.

<Comparative example 7>

An exterior material for an electrical storage device was obtained in the same manner as in Example 1, except that silica particles with an average particle diameter of 0.2 μm were used as incompatible particles instead of silica particles with an average particle diameter of 1.0 μm.

<Comparative example 8>

An exterior material for an electrical storage device was obtained in the same manner as in Example 1, except that silica particles with an average particle diameter of 5.0 μm were used as incompatible particles instead of silica particles with an average particle diameter of 1.0 μm.

<Method of measuring arithmetic mean height>

The arithmetic average height (Sa) of the surface 7a of the first heat-sealable resin layer (innermost layer) 7 of each exterior material for electrical storage devices obtained as described above was determined as follows. That is, using a scanning white interference microscope VS1330 manufactured by Hitachi High Technologies Co., Ltd., a 5x single field of view (938 The arithmetic mean height (Sa) of the surface 7a of the innermost layer 7 of the exterior material 1 was determined as mm × 703 mm).

[Table 1]

[Table 2]

[Table 3]

Each of the exterior materials for electrical storage devices obtained as described above was evaluated based on the following evaluation method. The results are shown in Table 3.

<Moldability evaluation method>

Using a molding depth-free straight mold, deep drawing one-stage molding was performed on the exterior material under the molding conditions below, and each molding depth (9.0 mm, 8.5 mm, 8.0 mm, 7.5 mm, 7.0 mm, 6.5 mm, 6.0 mm) was performed on the exterior material. The formability is evaluated at each size (mm, 5.5 mm, 5.0 mm, 4.5 mm, 4.0 mm, 3.5 mm, 3.0 mm, 2.5 mm, 2.0 mm), and the maximum value that can achieve good molding without any pin holes at the corners is determined. The molding depth (mm) was investigated, and moldability was evaluated based on the following evaluation criteria. Additionally, the presence or absence of a pinhole was investigated by visually observing the presence or absence of transmitted light passing through the pinhole.

(Molding conditions)

Molding mold... Punch: 33.3mm×53.9mm, Die: 80mm×120mm, Corner R: 2mm, Punch R: 1.3mm, Die R: 1mm

Blanking holding pad (しゎ狎さえ) pressure… Gauge: 0.475 MPa, actual pressure (calculated value): 0.7 MPa, material… SC (carbon steel) material, only the punch R is chrome plated.

(Criteria)

「◎」… The maximum molding depth without pinholes and cracks is 7.0 mm or more.

「○」… The maximum molding depth at which pinholes and cracks do not occur is 5.0 mm or more but less than 7.0 mm.

「×」… The maximum molding depth at which pinholes and cracks do not occur is less than 5.0 mm.

<White cloud prevention evaluation method>

Prepare a single piece of the sealant film (3) before adhesive lamination on the aluminum foil (4), and use a haze meter (“HM-150” manufactured by Murakami Color Research Institute, Inc.) in accordance with JIS K 7136-2000. The haze rate (haze rate) was measured and evaluated based on the following criteria.

(Criteria)

「◎」… Haze rate is less than 3% (excellent visibility for inspection of defects such as delamination)

「○… Haze rate is 3% or more but less than 10% (good visibility for inspection of defects such as delamination)

「×」… The haze rate is over 10% (visibility for inspection of defects such as delamination is poor).

<Evaluation method for presence or absence of white powder (prevention of white powder expression)>

After cutting out a square-shaped test piece measuring 600 mm in height and 100 mm in width from the exterior material for each electrical storage device, the obtained test piece was placed on the test table with the inner layer 3 (i.e., the surface 7a of the innermost layer) facing upward. , A SUS weight (mass 1.3 kg, contact surface size 55 mm x 50 mm) wrapped with black webbing and having a black surface was placed on the upper surface of this test piece. By pulling in a horizontal direction parallel to the upper surface of the test specimen at a tensile speed of 4 cm/sec, the weight was pulled and moved over a length of 400 mm while in contact with the upper surface of the test specimen. Observe the webbing (black) of the contact surface of the weight after the tension movement with the naked eye, and those with significant white powder on the surface of the webbing (black) are marked as “×”, and those with only a little white powder are marked as “○”. And those where there was almost no white powder or where white powder was not recognized were designated as “◎”. Additionally, as the black material, “Static Elimination Sheet S SD2525 3100” manufactured by TRUSCO was used.

As is clear from the table, the exterior materials for electrical storage devices of Examples 1 to 21 of the present invention have a maximum molding depth of 5.0 mm or more, and can ensure good moldability and suppress clouding in the exterior materials. The visibility for inspection of defects such as delamination was good, and it was difficult for white powder to appear on the surface of the exterior material.

On the other hand, in Comparative Examples 1 to 8, which deviated from the specified range of the present invention, the evaluation of moldability, white cloud prevention, and white powder prevention was poor.

The exterior material for an electrical storage device according to the present invention is, as a specific example,

·Electrical storage devices such as lithium secondary batteries (lithium ion batteries, lithium polymer batteries, etc.)

Lithium ion capacitor

·Electric 2 middle layer condenser

It is used as an exterior material for various electrical storage devices. In addition, the electrical storage device according to the present invention includes an all-solid-state battery in addition to the electrical storage devices illustrated above.

This application claims priority from Japanese Patent Application No. 2017-187923 filed on September 28, 2017, and its disclosure constitutes a part of this application as is.

The terms and descriptions used herein are used to describe embodiments related to the present invention, and the present invention is not limited thereto. The present invention, as long as it is within the scope of the claims, allows any design changes as long as it does not deviate from the spirit.

1: Exterior material for power storage device
2: Base layer (outer layer)
3: Heat-sealable resin layer (inner layer)
4: Metal foil layer
7: First heat-sealable resin layer (innermost layer)
8: Second heat-sealable resin layer
9: Third heat-sealable resin layer
10: External case
15: Exterior member
30: power storage device
31: Power storage device main body

Claims (9)

An exterior material for an electrical storage device comprising a base material layer as an outer layer, a heat-sealable resin layer as an inner layer, and a metal foil layer disposed between these two layers,
The heat-sealable resin layer includes a first heat-sealable resin layer forming the innermost layer of the exterior material, a second heat-sealable resin layer laminated on the surface of the first heat-sealable resin layer on the metal foil layer side, and , a laminate of three or more layers including a third heat-sealable resin layer laminated on the surface of the second heat-sealable resin layer on the metal foil layer side or disposed on the metal foil layer side,
The first heat-sealable resin layer is a first resin composition containing a random copolymer containing propylene and other copolymerization components other than propylene as a copolymerization component, a lubricant, and incompatible particles with an average particle diameter of 0.5 μm to 4 μm. It consists of, the content of the random copolymer in the first resin composition is 50% by mass or more, and the content of the incompatible particles in the first resin composition is in the range of 1000 ppm to 6000 ppm,
The second heat-sealable resin layer is composed of a block copolymer containing propylene and other copolymerization components other than propylene as a copolymerization component, and a second resin composition containing incompatible particles with an average particle diameter of 0.5 μm to 4 μm, , the content of the block copolymer in the second resin composition is 50% by mass or more, and the content of the incompatible particles in the second resin composition exceeds 0 ppm and is 100 ppm or less,
The third heat-sealable resin layer is made of a third resin composition containing propylene as a copolymerization component and a random copolymer containing other copolymerization components other than propylene, and the random copolymer in the third resin composition The content is 50% by mass or more,
The third resin composition is a composition containing no incompatible particles, or a composition containing more than 0 ppm and less than 6000 ppm of incompatible particles with an average particle diameter of 0.5 μm to 4 μm. An exterior material for an electrical storage device comprising a base material layer as an outer layer, a heat-sealable resin layer as an inner layer, and a metal foil layer disposed between these two layers,
The heat-sealable resin layer includes a first heat-sealable resin layer forming the innermost layer of the exterior material, a second heat-sealable resin layer laminated on the surface of the first heat-sealable resin layer on the metal foil layer side, and , a laminate of three or more layers including a third heat-sealable resin layer laminated on the surface of the second heat-sealable resin layer on the metal foil layer side or disposed on the metal foil layer side,
The first heat-sealable resin layer is a first resin composition containing a random copolymer containing propylene and other copolymerization components other than propylene as a copolymerization component, a lubricant, and incompatible particles with an average particle diameter of 0.5 μm to 4 μm. It consists of, the content of the random copolymer in the first resin composition is 50% by mass or more, and the content of the incompatible particles in the first resin composition is in the range of 1000 ppm to 6000 ppm,
The second heat-sealable resin layer is made of a second resin composition that contains propylene as a copolymerization component and a block copolymer containing other copolymerization components other than propylene and does not contain incompatible particles, and the second resin composition The content of the block copolymer is 50% by mass or more,
The third heat-sealable resin layer is made of a third resin composition containing propylene as a copolymerization component and a random copolymer containing other copolymerization components other than propylene, and the random copolymer in the third resin composition The content is 50% by mass or more,
The third resin composition is a composition containing no incompatible particles, or a composition containing incompatible particles with an average particle diameter of 0.5 μm to 4 μm in an amount exceeding 0 ppm and not exceeding 6000 ppm. delete According to claim 1 or 2,
An exterior material for an electrical storage device, wherein the arithmetic mean height (Sa) of the inner surface of the first heat-sealable resin layer is 50 nm to 200 nm. According to claim 1 or 2,
The content of the lubricant in the first resin composition is 100 ppm to 2000 ppm, the second resin composition further contains a lubricant, and the content of the lubricant in the second resin composition is 500 ppm to 5000 ppm. Exterior material for devices. According to claim 1 or 2,
The heat-sealable resin layer consists of the first heat-sealable resin layer, the second heat-sealable resin layer, and the third heat-sealable resin layer,
An exterior material for an electrical storage device, wherein the thickness of the first heat-sealable resin layer is 5% to 30% of the total thickness of the heat-sealable resin layer. An exterior case for an electrical storage device, comprising a molded body of the exterior material for an electrical storage device according to claim 1 or 2. A power storage device main body,
It is provided with one or two types of exterior members selected from the group consisting of the exterior material for an electrical storage device according to claim 1 or 2, and an exterior case for an electrical storage device made of a molded body of the exterior material for an electrical storage device according to claim 1, , A power storage device characterized in that the power storage device main body is exteriorized with the exterior member. A power storage device main body,
It is provided with one or two types of exterior members selected from the group consisting of the exterior material for an electrical storage device according to claim 1 or 2, and an exterior case for an electrical storage device made of a molded body of the exterior material for an electrical storage device according to claim 2; , A power storage device characterized in that the power storage device main body is exteriorized with the exterior member.

Images