JP6936093B2 - Exterior material for power storage device, exterior case for power storage device and power storage device - Google Patents

Description

The present invention is for power storage devices such as batteries and capacitors used in portable devices such as smartphones and tablets, hybrid vehicles, electric vehicles, wind power generation, solar power generation, and nighttime electricity storage. The present invention relates to an exterior material and a power storage device exteriorized by the exterior material.

In the present specification and 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, storage devices such as lithium ion secondary batteries, lithium polymer secondary batteries, lithium ion capacitors, and electric double-layer capacitors mounted on these devices have become thinner and lighter. As the exterior material, a laminate composed of a heat-resistant resin layer / adhesive layer / metal foil layer / adhesive layer / thermoplastic resin layer (inner sealant layer) is used instead of the conventional metal can. In addition, power supplies for electric vehicles, large power supplies for power storage, capacitors, and the like are increasingly being exteriorized with a laminate (exterior material) having the above configuration. By performing overhang molding or deep drawing molding on the laminated body, it is molded into a three-dimensional shape such as a substantially rectangular parallelepiped shape. By molding into such a three-dimensional shape, it is possible to secure an accommodation space for accommodating the main body of the power storage device.

In order to form such a three-dimensional shape in a good state without pinholes or breakage, it is required to improve the slipperiness of the surface of the inner sealant layer. As a substance for improving the slipperiness of the surface of the inner sealant layer and ensuring good moldability, a structure in which the inner sealant layer contains an anti-blocking agent (AB agent) is known (see Patent Document 1). ..

Similarly, in order to improve slipperiness and ensure good moldability, an acid resistance imparting layer is provided as an outermost layer on one surface of the base material layer, and an acid resistance imparting layer is provided on the other surface of the base material layer. An exterior material for a lithium ion battery in which one adhesive layer, an aluminum foil layer provided with a corrosion prevention treatment layer on at least one surface, a second adhesive layer, and a sealant layer are sequentially laminated, and a slip agent is applied to the outer surface of the sealant layer. At least one of (fatty acid amide, etc.) and anti-blocking agent (silica particles, etc.) is applied, or at least one of slip agent (fatty acid amide, etc.) and anti-blocking agent (silica particles, etc.) is blended in the sealant layer. An exterior material for a lithium ion battery having a different configuration is known (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.

Japanese Unexamined Patent Publication No. 2001-266811 Japanese Unexamined Patent Publication No. 2015-53289

However, if an excessive 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 tends to become cloudy, and the whitening of the sealant layer causes delamination in the exterior material. There was a problem that even if (delamination) occurred, it was easy to overlook in the quality inspection.

Of course, if the amount of the anti-blocking agent added is reduced, the problem of white turbidity of the sealant layer can be solved, but the slipperiness of the surface of the sealant layer is lowered, and good molding cannot be performed. Conventionally, it has been difficult to achieve both good moldability and suppression of white turbidity.

Further, 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 heating retention time and the storage period in the production process of the exterior material (laminated material), and during molding. Although the slipperiness is good, the lubricant is excessively deposited on the surface, so that the lubricant adheres and accumulates on the molding surface of the molding die during molding of the exterior material, and white powder (white powder due to the lubricant) is generated. If such white powder adheres and accumulates on the molding surface of the molding die, it becomes difficult to perform good molding. Therefore, it is 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 is lowered by cleaning and removing the white powder.

The present invention has been made in view of such a technical background, and it is possible to secure good slipperiness at the time of molding, secure good moldability, suppress white turbidity in the exterior material, and surface. It is an object of the present invention to provide an exterior material for a power storage device, an exterior case for a power storage device, and a power storage device in which white powder is hard to be exposed.

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

[1] An exterior material for a power storage device including a base material layer as an outer layer, a heat-sealing resin layer as an inner layer, and a metal foil layer arranged between both layers.
The heat-sealing resin layer is formed by laminating a first heat-sealing resin layer forming the innermost layer of the exterior material and a second surface of the first heat-sealing resin layer on the metal leaf layer side. The heat-sealing resin layer and the third heat-sealing resin layer laminated on the surface of the second heat-sealing resin layer on the metal leaf layer side or arranged on the metal leaf layer side are provided. Consists of three or more layers including
The first heat-sealing resin layer is incompatible with a random copolymer containing propylene and other copolymerization components other than propylene as copolymerization components, a lubricant, and an average particle size of 0.5 μm to 4 μm. The first resin composition containing particles, the content of the random copolymer in the first resin composition is 50% by mass or more, and the incompatible particles in the first resin composition. The content is in the range of 1000 ppm to 6000 ppm and
The second heat-sealing resin layer comprises a block copolymer containing propylene as a copolymerization component and other copolymerization components other than propylene, and incompatible particles having an average particle size 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 is 50% by mass or more. More than 0 ppm and less than 100 ppm,
The third heat-sealing resin layer comprises a third resin composition containing a random copolymer containing propylene as a copolymerization component and other copolymerization components other than propylene, and the third resin composition. An exterior material for a power storage device, characterized in that the content of the random copolymer is 50% by mass or more.

[2] An exterior material for a power storage device including a base material layer as an outer layer, a heat-sealing resin layer as an inner layer, and a metal foil layer arranged between both layers.
The heat-sealing resin layer is formed by laminating a first heat-sealing resin layer forming the innermost layer of the exterior material and a second surface of the first heat-sealing resin layer on the metal leaf layer side. The heat-sealing resin layer and the third heat-sealing resin layer laminated on the surface of the second heat-sealing resin layer on the metal leaf layer side or arranged on the metal leaf layer side are provided. Consists of three or more layers including
The first heat-sealing resin layer is incompatible with a random copolymer containing propylene and other copolymerization components other than propylene as copolymerization components, a lubricant, and an average particle size of 0.5 μm to 4 μm. The first resin composition containing particles, the content of the random copolymer in the first resin composition is 50% by mass or more, and the incompatible particles in the first resin composition. The content is in the range of 1000 ppm to 6000 ppm and
The second heat-sealing resin layer comprises a second resin composition containing a block copolymer containing propylene as a copolymerization component and other copolymerization components other than propylene, and not containing incompatible particles. , The content of the block copolymer in the second resin composition is 50% by mass or more.
The third heat-sealing resin layer comprises a third resin composition containing a random copolymer containing propylene as a copolymerization component and other copolymerization components other than propylene, and the third resin composition. An exterior material for a power storage device, characterized in that the content of the random copolymer is 50% by mass or more.

[3] The third resin composition has a composition that does not contain incompatible particles, or a composition that contains incompatible particles having an average particle size of 0.5 μm to 4 μm in an amount of more than 0 ppm and 6000 ppm or less. The exterior material for a power storage device according to 1 or 2.

[4] The exterior material for a power storage device according to any one of items 1 to 3 above, wherein the arithmetic mean height (Sa) of the inner surface of the first heat-sealing 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 2000 ppm. The exterior material for a power storage device according to any one of items 1 to 4 above, which is 5000 ppm.

[6] The heat-sealing resin layer comprises the first heat-sealing resin layer, the second heat-sealing resin layer, and the third heat-sealing resin layer.
The exterior material for a power storage device according to any one of the above items 1 to 5, wherein the thickness of the first heat-sealing resin layer is 5% to 30% of the total thickness of the heat-sealing resin layer. ..

[7] An exterior case for a power storage device made of a molded body of the exterior material for the power storage device according to any one of the above items 1 to 6.

[8] The main body of the power storage device and
It is provided with one or two types of exterior members selected from the group consisting of the exterior material for a power storage device according to any one of the above items 1 to 6 and the exterior case for a power storage device according to the above item 7.
A power storage device characterized in that the power storage device main body is covered with the exterior member.

In the inventions of [1] and [2], the first heat-sealing resin layer forming the innermost layer of the exterior material is the random copolymer and incompatible particles having an average particle diameter of 0.5 μm to 4 μm. Since it contains, it is possible to impart appropriate unevenness to the surface (inner surface) of the innermost layer, reduce the contact area during molding, and secure good slipperiness even if the amount of lubricant added is small. Good moldability can be ensured. By reducing the amount of lubricant added, the amount of bleeding of the lubricant can be reduced, so that white powder is less likely to appear on the surface of the exterior material, and adhesion contamination of the lubricant on the surface of the molding die can be suppressed.

Further, in the second heat-sealing resin layer, in the invention of [1], the content of incompatible particles having an average particle diameter of 0.5 μm to 4 μm exceeds 0 ppm and is 100 ppm or less, and the invention of [2] Since the structure does not contain incompatible particles (any average particle size), white turbidity can be prevented in the second heat-sealing resin layer (haze of the second heat-sealing resin layer). The rate can be extremely small and the transparency is excellent). Therefore, the exterior material for a power storage device of the present invention containing such a second heat-sealing resin layer can suppress white turbidity, which causes delamination in the exterior material. If so, it can be found by quality inspection, etc., and the quality of the product can be significantly improved.

Further, since the content of the block copolymer containing propylene and other copolymerization components other than propylene as the copolymerization component in the second heat-sealing resin layer is 50% by mass or more, the heat-bondable resin. The heat resistance and durability of the layer (sealant layer) can be improved, and liquid leakage after heat sealing can be sufficiently prevented.

Further, the third heat-sealing resin layer arranged on the metal foil side has a content of 50% by mass or more of a random copolymer containing propylene as a copolymerization component and other copolymerization components other than propylene. Therefore, the adhesiveness with the metal foil layer can be improved.

In addition, the first heat-sealing resin layer forming the innermost layer of the exterior material has a content of 50% by mass or more of a random copolymer containing propylene as a copolymerization component and other copolymerization components other than propylene. Therefore, the heat-sealing temperature at the time of sealing can be lowered (good sealing can be achieved by sealing at a lower heat-sealing temperature).

In the invention of [3], the third resin composition has a composition containing incompatible particles having an average particle diameter of 0.5 μm to 4 μm in an average particle size of more than 0 ppm and 6000 ppm or less, and has adhesiveness to a metal foil layer. In a configuration in which the third resin composition does not contain incompatible particles, the adhesiveness to 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-sealing resin layer is 50 nm to 200 nm, the slipperiness can be further improved and the moldability is improved. It is possible to further reduce white turbidity in the first heat-sealing resin layer.

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

In the invention of [6], the thickness of the first heat-sealing resin layer is 5% to 30% of the total thickness of the heat-sealing resin layer, so that the heat-sealing property of the three-layer laminated structure is obtained. The surface of the resin layer on the metal leaf side (the surface of the third heat-sealing resin layer on the metal leaf side) is less susceptible to the influence of incompatible particles, and the surface on the metal leaf side is formed to be a smoother surface. It is possible to sufficiently prevent air bubbles from being mixed during laminating (adhesion, etc.).

In the invention of [7], since the white turbidity of the exterior material can be suppressed, if delamination occurs in the exterior case, it can be found by quality inspection or the like, and the quality as a product is remarkably improved. Can be made to. In addition, it is possible to provide an outer case that has been well molded.

In the invention of [8], since the outer case is provided with a well-formed outer case and the white turbidity can be suppressed, if delamination occurs in the outer case, a quality inspection or the like is performed. Can be found in, and can provide a power storage device with a high quality exterior.

It is sectional drawing which shows one Embodiment of the exterior material for a power storage device which concerns on this invention. It is sectional drawing which shows one Embodiment of the power storage device which concerns on this invention. FIG. 2 is a perspective view showing a separated state before heat-sealing the exterior material (planar shape), 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.

The exterior material 1 for a power storage device according to the present invention includes a base material layer 2 as an outer layer, a heat-sealing resin layer 3 as an inner layer, and a metal foil layer 4 arranged between both layers. The heat-sealing resin layer 3 is formed on the first heat-sealing resin layer 7 forming the innermost layer of the exterior material 1 and the surface of the first heat-sealing resin layer 7 on the metal leaf layer side. The laminated second heat-sealing resin layer 8 and the third heat-melting laminated on the surface of the second heat-sealing resin layer 8 on the metal leaf layer side or arranged on the metal leaf layer side. It is composed of a laminated body containing three or more layers including the adhesive resin layer 9 (see FIG. 1).

In the present invention, the first heat-sealing resin layer 7 has a random copolymer containing "propylene" and "other copolymerization components other than propylene" as copolymerization components, a lubricant, and an average particle size. It is composed of a first resin composition containing 0.5 μm to 4 μm incompatible particles, and the content of the random copolymer in the first resin composition is 50% by mass or more, and the first resin. The content of the incompatible particles having an average particle size of 0.5 μm to 4 μm in the composition is set in the range of 1000 ppm to 6000 ppm.

Further, the second heat-sealing resin layer 8 is a block copolymer containing "propylene" and "other copolymerization components other than propylene" as copolymerization components, and has an average particle size of 0.5 μm to 4 μm. The block copolymer is composed of a second resin composition containing the incompatible particles of the above, and the content of the block copolymer in the second resin composition is 50% by mass or more, and the average in the second resin composition. The content of incompatible particles having a particle size of 0.5 μm to 4 μm is set to be more than 0 ppm and 100 ppm or less. Alternatively, the second resin composition may be configured so as not to contain incompatible particles having any average particle size.

Further, the third heat-sealing resin layer 9 is composed of a third resin composition containing a random copolymer containing "propylene" and "other copolymerization components other than propylene" as copolymerization components. The content of the random copolymer in the third resin composition is set to 50% by mass or more.

FIG. 1 shows an embodiment of the exterior material 1 for a power storage device according to the present invention. In the exterior material 1 for a power storage device of the present embodiment, the heat-sealing resin layer (inner layer) 3 is laminated and integrated on one surface of the metal foil layer 4 via an inner adhesive layer 6. The base material layer (outer layer) 2 is laminated and integrated on the other surface of the metal foil layer 4 via the outer adhesive layer 5. Then, in the present embodiment shown in FIG. 1, the heat-sealing resin layer (inner layer) 3 includes a first heat-sealing resin layer constituting the innermost layer 7 of the inner layer 3 and the first heat. On the surface of the second heat-sealing resin layer 7 on the side of the metal leaf layer 4 and the surface of the second heat-sealing resin layer 8 on the side of the metal leaf layer 4. It is a three-layer laminated structure composed of a laminated third heat-sealing resin layer 9. The first heat-sealing resin layer (innermost layer) 7 is exposed on the inner surface of the exterior material 1 for a power storage device (see FIG. 1). Further, the third heat-sealing resin layer 9 and one surface of the metal foil layer 4 are bonded and integrated by the inner adhesive layer 6 (see FIG. 1).

The exterior material 1 for a power storage device shown in FIG. 1 is used for a lithium ion secondary battery case. The exterior material 1 for a power storage device can be used as a case for a secondary battery or the like by being subjected to molding such as deep drawing molding and overhang molding.

In the present invention, the heat-sealing resin layer (inner layer; sealant layer) 3 is provided with excellent chemical resistance to a highly corrosive electrolytic solution or the like used in a lithium ion secondary battery or the like. , It plays a role of imparting heat sealability to the exterior material.

The first heat-sealing resin layer 7 and the third heat-sealing resin layer 9 both contain "propylene" and "other copolymerization components other than propylene" as copolymerization components at random co-weights. Contains coalescence. Regarding the random copolymer, the "other copolymerization component other than propylene" is not particularly limited, but for example, ethylene, 1-butane, 1-hexene, 1-pentene, 4methyl-1. -In addition to olefin components such as pentene, butadiene and the like can be mentioned.

The second heat-sealing resin layer 8 contains a block copolymer containing "propylene" and "other copolymerization components other than propylene" as copolymerization components. Regarding the block copolymer, the "other copolymer components other than propylene" are not particularly limited, but for example, ethylene, 1-butane, 1-hexene, 1-pentene, 4methyl-1. -In addition to olefin components such as penten, butadiene and the like can be mentioned.

In the present invention, the incompatible particles constitute a first heat-sealing resin layer 7, a second heat-sealing resin layer 8, a third heat-sealing resin layer 9, and the like to which the particles are added. The particles are not particularly limited as long as they are incompatible with the resin (copolymer). Above all, it is preferable to use an anti-blocking agent (AB agent) as the incompatible particles.

The antiblocking agent is not particularly limited, and examples thereof include inorganic particles and resin particles. The inorganic particles are not particularly limited, but are, for example, inorganic oxide particles (silica particles, alumina particles, titanium oxide particles, etc.), inorganic carbonate particles (calcium carbonate particles, barium carbonate particles, etc.), and inorganic particles. Examples thereof include silicate particles (aluminum silicate particles, talc particles, kaolin particles, etc.). The resin particles are not particularly limited, and examples thereof include acrylic resin particles, polyolefin resin particles (polyethylene resin particles, polypropylene resin particles), and polystyrene resin particles.

As the 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 in combination, it is preferable to use two or more types of incompatible particles having different average particle diameters. In this case, the surface (inner surface) of the innermost layer (first heat-sealing resin layer) 7 is used. The effect that the distribution of the overall roughness of 7a can be made uniform can be obtained. Further, as the incompatible particles, those having a specific gravity of 3 or less are preferably used, and in this case, the effect that the incompatible particles can be uniformly dispersed in the layer can be obtained.

As the incompatible particles, incompatible particles having an average particle diameter of 0.5 μm to 4 μm are used. If incompatible particles with an average particle size of less than 0.5 μm are used, the surface irregularities required to prevent blocking of the exterior material cannot be formed well, and if incompatible particles with an average particle size of 4 μm or more are used, incompatible particles are used. It causes problems of typed particles and shedding of incompatible particles. As the incompatible particles, it is preferable to use incompatible particles having an average particle diameter of 0.7 μm to 2.5 μm.

The content (concentration) of "incompatible particles having an average particle size of 0.5 μm to 4 μm" in the first heat-sealing resin layer 7 is set in the range of 1000 ppm to 6000 ppm. If it is less than 1000 ppm, it becomes difficult to form irregularities over the entire surface (inner surface) 7a of the innermost layer (first heat-sealing resin layer) 7, and if it exceeds 6000 ppm, it becomes difficult for the first heat-sealing resin layer 7 to form irregularities. The degree of white turbidity increases, heat sealing cannot be performed sufficiently, and incompatible particles fall off. The content (concentration) of "incompatible particles having an average particle size of 0.5 μm to 4 μm" in the first heat-sealing resin layer 7 is preferably set in the range of 2000 ppm to 5000 ppm.

The content (concentration) of the "incompatible particles having an average particle size of 0.5 μm to 4 μm" in the second heat-sealing resin layer 8 is set to be more than 0 ppm and 100 ppm or less, or The second heat-sealing resin layer 8 does not contain incompatible particles (regardless of the average particle size). With such a configuration, it is possible to prevent the second heat-sealing resin layer 8 from becoming cloudy. That is, if the content exceeds 100 ppm, even if delamination (peeling) occurs between the metal foil layer 4 and the heat-sealing resin layer 3, it cannot be found by quality inspection or the like, or it becomes difficult to find it. ..

The third heat-sealing resin layer 9 preferably contains incompatible particles having an average particle size of 0.5 μm to 4 μm in an amount of more than 0 ppm and 6000 ppm or less. When such a configuration is adopted, the adhesiveness with the metal foil layer 4 can be further improved, and the white turbidity of the third heat-sealing resin layer 9 can be suppressed, so that the metal foil layer 4 and the metal foil layer 4 can be combined with each other. If delamination (peeling) occurs between the heat-sealing resin layers 3, it can be found by quality inspection or the like. Alternatively, the third heat-sealing resin layer 9 preferably has a composition that does not contain incompatible particles (regardless of the average particle size), and in this case, the adhesiveness to the metal foil layer 4 is improved. Since it can be further improved and the third heat-sealing resin layer 9 does not become cloudy, if delamination (peeling) occurs between the metal foil layer 4 and the heat-sealing resin layer 3, a quality inspection or the like is performed. Can be easily found at.

When the three-layer laminated structure of FIG. 1 is adopted as the heat-sealing resin layer 3, the ratio of the thickness of the three layers is the thickness of the first heat-sealing resin layer 7 / the second heat-sealing property. It is preferable that the thickness of the resin layer 8 / the thickness of the third heat-sealing resin layer 9 is 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 a fatty acid amide is preferably used. The fatty acid amide is not particularly limited, but for example, saturated fatty acid amide, unsaturated fatty acid amide, substituted amide, methylol amide, saturated fatty acid bisamide, unsaturated fatty acid bisamide, fatty acid ester amide, aromatic bisamide and the like. Can be mentioned.

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

The substituted amide is not particularly limited, but is, for example, N-oleyl palmitate amide, N-stearyl stearic acid amide, N-stearyl oleic acid amide, N-oleyl stearic acid amide, N-stearyl erucic acid. Examples include amides. The methylolamide is not particularly limited, and examples thereof include methylolstearic amide.

The saturated fatty acid bisamide is not particularly limited, but for example, methylene bisstearic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide, ethylene bisstearic acid amide, ethylene bishydroxystearic acid amide, ethylene. Bisbechenic acid amide, hexamethylene bisstearic acid amide, hexamethylene bisbechenic acid amide, hexamethylene hydroxystearic acid amide, N, N'-distearyl adipate amide, N, N'-distearyl sebacic acid amide and the like. Be done.

The unsaturated fatty acid bisamide is not particularly limited, and examples thereof include ethylene bisoleic acid amide, ethylene biserucate amide, hexamethylene bisoleic acid amide, and N, N'-diorail sebacic acid amide. Can be mentioned.

The fatty acid ester amide is not particularly limited, and examples thereof include stearoamide ethyl stearate and the like. The aromatic bisamide is not particularly limited, and examples thereof include m-xylylene bisstearic acid amide, m-xylylene bishydroxystearic acid amide, and N, N'-cystelyl isophthalic acid amide. Can be mentioned.

The content of the lubricant in the first heat-sealing 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-sealing resin layer 7 can be appropriately precipitated on the surface 7a to further improve the slipperiness, and when it is 2000 ppm or less, the lubricant is on the surface 7a. Is not excessively deposited, and white powder is less likely to appear on the surface 7a. Above all, the content of the lubricant in the first heat-sealing resin layer 7 is more preferably set to 100 ppm to 1000 ppm.

It is preferable that the second heat-sealing resin layer 8 contains a lubricant. The content of the lubricant in the second heat-sealing resin layer 8 is preferably set to 500 ppm to 5000 ppm. When the content is 500 ppm or more, the lubricant existing in the first heat-sealing resin layer 7 permeates the second heat-sealing resin layer 8 to cause the lubricant in the first heat-sealing resin layer 7. It is possible to prevent a deficiency state, and it is possible to prevent white powder contamination on the surface of the exterior material and white powder contamination of peripheral devices due to the lubricant bleeding out when the amount is 5000 ppm or less.

It is preferable that the third heat-sealing resin layer 9 also contains a lubricant, but since there is a concern that the lamination strength may decrease, the lubricant exceeds 0 ppm in the third heat-sealing resin layer 9. It is preferable to contain 250 ppm or less. Of course, the third heat-sealing resin layer 9 may be configured so as not to contain a lubricant.

In the present invention, the thickness of the first heat-sealing resin layer 7 is preferably set to 5% to 30% of the total thickness of the heat-sealing resin layer 3. By setting it to 5% or more, sufficient surface roughness can be obtained to improve slipperiness, and sufficient sealing strength can be ensured at the time of thermal sealing. Further, by setting it to 30% or less, the durability of the heat-sealing resin layer 3 after heat sealing can be further improved, and the surface of the heat-sealing resin layer 3 on the metal leaf side is not formed. It becomes less susceptible to the influence of compatible particles, and the surface on the metal foil side can be formed into a smoother surface, so that air bubbles can be sufficiently prevented from being mixed during lamination (adhesion, etc.). Above all, the thickness of the first heat-sealing resin layer 7 is particularly preferably set to 10% to 20% of the total thickness of the heat-sealing resin layer 3.

In the present invention, a part of the lubricant is exposed (bleed) and adheres to the surface 7a of the innermost layer (first heat-sealing resin layer) 7 of the heat-sealing resin layer 3. the innermost layer adhesion amount of the lubricant at the surface 7a of the (first heat fusion resin layer) 7 is preferably in the range of ^{0.1μg / cm 2 ~1.0μg / cm 2} .

In the embodiment shown in FIG. 1, the heat-sealing resin layer (inner layer) 3 is a first heat-sealing resin layer / second heat-sealing resin layer constituting the innermost layer 7 of the exterior material 1. Although a three-layer laminated structure of the 8 / third heat-sealing resin layer 9 is adopted, the structure is not particularly limited to such a structure, and the second heat-sealing resin layer 8 and the third heat-sealing resin layer 8 are not particularly limited to such a structure. It is also possible to adopt a configuration in which one or a plurality of "other heat-sealing resin layers" are laminated and arranged between the adhesive resin layers 9. That is, the "... in the second heat-sealing resin layer 8 ... (omitted) ... the third heat-sealing resin arranged on the metal leaf layer side" defined in the inventions of the above [1] and [2]. The term "arranged on the metal leaf layer side " in "consisting of a laminated body containing three or more layers including the layer 9" refers to the second heat-sealing resin layer 8 and the third heat-sealing resin layer 9. It defines a structure in which one or a plurality of other heat-sealing resin layers are laminated and arranged between the two layers. The "other heat-sealing resin layer" includes, for example, the random copolymer having an elastomer component or a different amount of lubricant (random containing propylene and other copolymer components other than propylene as copolymer components). Copolymers), the block copolymers having different elastomer components and lubricant amounts (block copolymers containing propylene and other copolymerization components other than propylene as copolymerization components), homopolypropylene resins and the like.

In the present invention, the base material 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 when the exterior material 1 is heat-sealed is used. As the heat-resistant resin, a heat-resistant resin having a melting point higher than the melting point of the heat-sealing resin layer 3 (the melting point of the layer having the highest melting point among the first to third heat-sealing resin layers) by 10 ° C. or more is used. It is preferable to use a heat-resistant resin having a melting point of 20 ° C. or more higher than the melting point of the heat-sealing resin layer 3 (the melting point of the layer having the highest melting point among the first to third heat-sealing resin layers). Especially preferable.

The heat-resistant resin layer (outer layer) 2 is not particularly limited, and examples thereof include a polyamide film such as a nylon film and a polyester film, and these stretched films are preferably used. Among them, the heat-resistant resin layer 2 includes 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 a biaxially stretched polyethylene film. It is particularly preferable to use a phthalate (PEN) film. The nylon film is not particularly limited, and examples thereof include a 6-nylon film, a 6,6 nylon film, and an MXD nylon film. The heat-resistant resin layer 2 may be formed of a single layer, or may be formed of, for example, a multi-layer made of a polyester film / polyamide film (a multi-layer made of a PET film / nylon film, etc.). Is also good.

The thickness of the heat-resistant resin layer (outer layer) 2 is preferably 2 μm to 50 μm. When a polyester film is used, the thickness is preferably 2 μm to 50 μm, and when a nylon film is used, the thickness is preferably 7 μm to 50 μm. Sufficient strength as a packaging material can be ensured by setting it to the above-mentioned preferable lower limit value or more, and stress during molding such as overhang molding and draw forming can be reduced and formability is improved by setting it to the above-mentioned preferable upper limit value or less. Can be made to.

The metal leaf layer 4 plays a role of imparting a gas barrier property to prevent the invasion of oxygen and moisture to the exterior material 1. The metal foil layer 4 is not particularly limited, and examples thereof include an aluminum foil, a SUS foil (stainless steel foil), a Cu foil, a Ni foil, a Ti foil, and the like. Among them, an aluminum foil and a SUS foil ( (Stainless foil) is preferably used. The thickness of the metal foil layer 4 is preferably 5 μm to 120 μm. When it is 5 μm or more, it is possible to prevent the occurrence of pinholes during rolling when manufacturing a metal foil, and when it is 120 μm or less, the stress during molding such as overhang molding and draw forming can be reduced and the formability is improved. be able to. Above all, the thickness of the metal foil layer 4 is more preferably 10 μm to 80 μm.

It is preferable that at least the inner surface (the surface on the inner layer 3 side) of the metal foil layer 4 is subjected to chemical conversion treatment. By performing such a chemical conversion treatment, it is possible to sufficiently prevent the metal foil surface from being corroded by the contents (electrolyte solution of the battery, etc.). For example, the metal foil is subjected to chemical conversion treatment by performing the following treatment. That is, for example, on the surface of the metal leaf that has been degreased,
1) Phosphoric acid and
With chromic acid
An aqueous solution of a mixture containing at least one compound selected from the group consisting of a metal salt of fluoride and a non-metal salt of fluoride 2) Phosphoric acid.
At least one resin selected from the group consisting of acrylic resins, chitosan derivative resins and phenolic resins, and
An aqueous solution of a mixture containing at least one compound selected from the group consisting of chromic acid and a chromium (III) salt 3) phosphoric acid.
At least one resin selected from the group consisting of acrylic resins, chitosan derivative resins and phenolic resins, and
At least one compound selected from the group consisting of chromic acid and chromium (III) salt, and
An aqueous solution of a mixture containing at least one compound selected from the group consisting of a metal salt of fluoride and a non-metal salt of fluoride An aqueous solution of any one of 1) to 3) above is applied and then dried. By doing so, the chemical conversion process is performed.

The conversion coating, chromium coating weight preferably is 0.1mg / m ² ~50mg / m ² as a (per one surface), in particular 2mg / m ² ~20mg / m 2 preferred.

The outer adhesive 5 is not particularly limited, and examples thereof include a thermosetting adhesive. The thermosetting adhesive is not particularly limited, and examples thereof include an olefin-based adhesive, an epoxy-based adhesive, and an acrylic-based adhesive. The thickness of the outer adhesive layer 5 is preferably set to 1 μm to 5 μm. Above all, from the viewpoint of thinning and weight reduction of the packaging material 1, the thickness of the outer adhesive layer 5 is particularly preferably set to 1 μm to 3 μm.

The inner adhesive 6 is not particularly limited, and examples thereof include the thermosetting adhesive. The thickness of the inner adhesive layer 6 is preferably set to 1 μm to 5 μm. Above all, from the viewpoint of thinning and weight reduction of the packaging material 1, the thickness of the inner adhesive layer 6 is particularly preferably set to 1 μm to 3 μm.

The following additives are added to the base material layer 2 and the heat-sealing resin layer 3 (including the innermost layer 7) constituting the exterior material 1 for the power storage device, as long as the effects of the present invention are not impaired. You may. The additive is not particularly limited, but is, for example, an antioxidant, a plasticizer, an ultraviolet absorber, a fungicide, a colorant (pigment, dye, etc.), an antistatic agent, a rust preventive, and a moisture absorbing agent. Agents, oxygen absorbers and the like. The plasticizer is not particularly limited, but is, for example, glycerin fatty acid ester monoglyceride, glycerin fatty acid ester acetylated monoglyceride, glycerin fatty acid ester organic acid monoglyceride, glycerin fatty acid ester medium chain fatty acid triglyceride, polyglycerin fatty acid ester, sorbitan. Examples thereof include fatty acid esters, propylene glycol fatty acid esters, special fatty acid esters, and higher alcohol fatty acid esters.

The exterior case (battery case, etc.) 10 can be obtained by molding (deep drawing molding, overhang molding, etc.) the exterior material 1 for a power storage device of the present invention (see FIG. 3). The exterior material 1 of the present invention can be used as it is without being subjected to molding (see FIG. 3).

FIG. 2 shows an embodiment of the power storage device 30 configured by using the exterior material 1 for the power storage device of the present invention. The power storage device 30 is a lithium ion secondary battery. In the present embodiment, as shown in FIGS. 2 and 3, the exterior member 15 is composed of the exterior case 10 obtained by molding the exterior material 1 and the flat exterior material 1. Thus, a substantially square-shaped power storage device main body (electrochemical element or the like) 31 is housed in the storage recess of the exterior case 10 obtained by molding the exterior material 1 of the present invention, and the power storage device main body 31 is housed. The exterior material 1 of the present invention is arranged on the surface with the heat-sealing resin layer 3 side facing inward (lower side) without being molded, and the heat-sealing resin layer of the planar exterior material 1 is arranged. 3 (1st heat-sealing resin layer 7) and the heat-sealing resin layer 3 (1st heat-sealing resin layer 7) of the flange portion (sealing peripheral portion) 29 of the outer case 10 ) Is sealed by heat sealing to form the power storage device 30 of the present invention (see FIGS. 2 and 3). The inner surface of the housing recess of the exterior case 10 is a heat-sealing resin layer 3 (first heat-sealing resin layer 7), and the outer surface of the housing recess is a base material layer (outer layer). It is 2 (see FIG. 3).

In FIG. 2, 39 is a heat-sealed portion in which the peripheral edge portion of the exterior material 1 and the flange portion (sealing peripheral edge portion) 29 of the exterior case 10 are joined (welded). In the power storage device 30, the tip of the tab lead connected to the power storage device main body 31 is led out to the outside of the exterior member 15, but the illustration is omitted.

The power storage device main body 31 is not particularly limited, and examples thereof include a battery main body, a capacitor main body, and a capacitor main body.

The width of the heat seal portion 39 is preferably set to 0.5 mm or more. Sealing can be reliably performed by setting the thickness to 0.5 mm or more. Above all, the width of the heat seal portion 39 is preferably set to 3 mm to 15 mm.

In the above embodiment, the exterior member 15 is composed of an exterior case 10 obtained by molding the exterior material 1 and a flat exterior material 1 (see FIGS. 2 and 3). The combination is not particularly limited, and for example, the exterior member 15 may be composed of a pair of flat exterior materials 1, or may be composed of a pair of exterior cases 10. You may.

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

<Example 1>
A chemical conversion treatment solution consisting of phosphoric acid, polyacrylic acid (acrylic resin), chromium (III) salt compound, water, and alcohol was applied to both sides of a 35 μm-thick aluminum foil 4, and then dried at 180 ° C. , A chemical conversion film was formed. The amount of chromium adhered to this chemical conversion film was ^{10 mg / m 2 per side.}

Next, a biaxially stretched 6 nylon film 2 having a thickness of 5 μm was dry-laminated (bonded) on one surface of the chemical conversion-treated aluminum foil 4 via a two-component curable urethane adhesive 5.

Next, a first 4.5 μm thick containing an ethylene-propylene random copolymer, 1000 ppm erucic acid amide (lubricant), and 2000 ppm silica particles (average particle size 1.0 μm; incompatible particles). Thickness containing heat-sealing resin non-stretched film 7, ethylene-propylene block copolymer, 1000 ppm erucic acid amide (lubricant), 50 ppm silica particles (average particle size 1.0 μm; incompatible particles) 21 μm second heat-sealing resin non-stretched film 8, ethylene-propylene random copolymer, 1000 ppm erucic acid amide (lubricant), 2000 ppm silica particles (average particle size 1.0 μm; incompatible particles). These three layers are laminated by co-extruding using a T-die so that the contained third heat-sealing resin non-stretched film 9 having a thickness of 4.5 μm is laminated in this order. A sealant film having a thickness of 30 μm (first heat-sealing resin non-stretched film layer 7 / second heat-sealing resin non-stretched film layer 8 / third heat-sealing resin non-stretched film layer 9) 3 is obtained. After that, the 9 surfaces of the third heat-sealing resin non-stretched film layer of the sealant film 3 are passed through a two-component curable maleic acid-modified polypropylene adhesive 6 to the other of the aluminum foil 4 after the dry lamination. It was overlapped on the surface, sandwiched between a rubber nip roll and a laminate roll heated to 100 ° C, crimped to dry laminate, wound around a roll shaft, and then aged at 40 ° C for 10 days (heating). After that, the exterior material 1 for a power storage device having the configuration shown in FIG. 1 was obtained by pulling it out from the roll shaft.

As the two-component curable maleic acid-modified polypropylene adhesive, 100 parts by mass of maleic acid-modified polypropylene (melting point 80 ° C., acid value 10 mgKOH / g) as a main agent, and an isocyanurate of hexamethylene diisocyanate as a curing agent. (NCO content: 20% by mass) Using an adhesive solution prepared by mixing 8 parts by mass and a solvent, the adhesive solution was applied to the aluminum foil 4 so ^{that the solid content coating amount was 2 g / m 2.} It was applied to the other surface, dried by heating, and then laminated on the 9th surface of the third non-stretched film layer of the sealant film 3.

<Example 2>
The same as in Example 1 except that the content of silica particles (incompatible particles) in the first heat-sealing resin layer (innermost layer) 7 and the third heat-sealing resin layer 9 was changed to 1000 ppm. Therefore, an exterior material 1 for a power storage device having the configuration shown in FIG. 1 was obtained.

<Example 3>
The same as in Example 1 except that the content of silica particles (incompatible particles) in the first heat-sealing resin layer (innermost layer) 7 and the third heat-sealing resin layer 9 was changed from 2000 ppm to 6000 ppm. Therefore, an exterior material 1 for a power storage device having the configuration shown in FIG. 1 was obtained.

<Example 4>
As the incompatible particles, the power storage device having the configuration shown in FIG. 1 is the same as in Example 1 except that silica particles having an average particle diameter of 3.0 μm are used instead of silica particles having an average particle diameter of 1.0 μm. Exterior material 1 was obtained.

<Example 5>
A power storage device having the configuration shown in FIG. 1 in the same manner as in Example 1 except that silica particles having an average particle diameter of 4.0 μm were used instead of silica particles having an average particle diameter of 1.0 μm as incompatible particles. Exterior material 1 was obtained.

<Example 6>
As the incompatible particles, the power storage device having the configuration shown in FIG. 1 is the same as in Example 1 except that silica particles having an average particle diameter of 0.5 μm are used instead of silica particles having an average particle diameter of 1.0 μm. Exterior material 1 was obtained.

<Example 7>
An exterior material 1 for a power storage device having the configuration shown in FIG. 1 was obtained in the same manner as in Example 1 except that the erucic acid amide content in the second heat-sealing resin layer 8 was changed from 1000 ppm to 6000 ppm.

<Example 8>
An exterior material 1 for a power storage device having the configuration shown in FIG. 1 was obtained in the same manner as in Example 1 except that the erucic acid amide content of 1000 ppm in the second heat-sealing resin layer 8 was changed to 400 ppm.

<Example 9>
A power storage device having the configuration shown in FIG. 1 in the same manner as in Example 1 except that the erucic acid amide content of 1000 ppm in the first heat-sealing resin layer 7 and the third heat-sealing resin layer 9 was changed to 3000 ppm. Exterior material 1 was obtained.

<Example 10>
A power storage device having the configuration shown in FIG. 1 in the same manner as in Example 1 except that the erucic acid amide content of 1000 ppm in the first heat-sealing resin layer 7 and the third heat-sealing resin layer 9 was changed to 50 ppm. Exterior material 1 was obtained.

<Example 11>
Examples except that the thickness of the first heat-sealing resin layer 7 was changed from 4.5 μm to 1.0 μm and the thickness of the third heat-sealing resin layer 9 was changed to 8.0 μm. In the same manner as in No. 1, an exterior material 1 for a power storage device having the configuration shown in FIG. 1 was obtained.

<Example 12>
The thickness of the first heat-sealing resin layer 7 was changed from 4.5 μm to 10 μm, the thickness of the second heat-sealing resin layer 8 was changed to 16 μm, and the thickness of the third heat-sealing resin layer 9 was changed to 16 μm. An exterior material 1 for a power storage device having the configuration shown in FIG. 1 was obtained in the same manner as in Example 1 except that the thickness of 4.5 μm was changed to 4.0 μm.

<Example 13>
Exterior material 1 for power storage device having the configuration shown in FIG. 1 in the same manner as in Example 1 except that the content of silica particles (incompatible particles) in the second heat-sealing resin layer 8 was changed from 50 ppm to 75 ppm. Got

<Example 14>
Exterior material 1 for power storage device having the configuration shown in FIG. 1 in the same manner as in Example 1 except that the content of silica particles (incompatible particles) in the second heat-sealing resin layer 8 was changed from 50 ppm to 25 ppm. Got

<Example 15>
The figure is the same as in Example 1 except that the content of silica particles (incompatible particles) in the second heat-sealing resin layer 8 is changed from 50 ppm to 0 ppm (incompatible particles are not contained). An exterior material 1 for a power storage device having the configuration shown in 1 was obtained.

<Example 16>
As the incompatible particles, the power storage device having the configuration shown in FIG. 1 is the same as in Example 1 except that silica particles having an average particle diameter of 2.0 μm are used instead of silica particles having an average particle diameter of 1.0 μm. Exterior material 1 was obtained.

<Example 17>
As the incompatible particles, the storage storage having the configuration shown in FIG. 1 is the same as in Example 1 except that barium carbonate particles having an average particle diameter of 1.0 μm are used instead of silica particles having an average particle diameter of 1.0 μm. The exterior material 1 for the device was obtained.

<Example 18>
As the incompatible particles, FIG. 1 shows in the same manner as in Example 1 except that acrylic resin beads (particles) having an average particle diameter of 1.0 μm were used instead of silica particles having an average particle diameter of 1.0 μm. An exterior material 1 for a power storage device having a configuration was obtained.

<Example 19>
An exterior material 1 for a power storage device having the configuration shown in FIG. 1 was obtained in the same manner as in Example 1 except that bechenic acid amide was used as the lubricant instead of erucic acid amide.

<Example 20>
Exterior material 1 for power storage device having the configuration shown in FIG. 1 in the same manner as in Example 1 except that the content of silica particles (incompatible particles) in the third heat-sealing resin layer 9 was changed from 2000 ppm to 50 ppm. Got

<Example 21>
The figure is the same as in Example 1 except that the content of silica particles (incompatible particles) in the third heat-sealing resin layer 9 is changed from 2000 ppm to 0 ppm (incompatible particles are not contained). An exterior material 1 for a power storage device having the configuration shown in 1 was obtained.

<Comparative example 1>
An exterior material for a power storage device was obtained in the same manner as in Example 1 except that the content of silica particles (incompatible particles) in the second heat-sealing resin layer 8 was changed from 50 ppm to 150 ppm.

<Comparative example 2>
An exterior material for a power storage device was obtained in the same manner as in Example 1 except that the content of silica particles (incompatible particles) in the first heat-sealing resin layer (innermost layer) 7 was changed from 2000 ppm to 800 ppm. ..

<Comparative example 3>
An exterior material for a power storage device was obtained in the same manner as in Example 1 except that the content of silica particles (incompatible particles) in the first heat-sealing resin layer (innermost layer) 7 was changed from 2000 ppm to 6500 ppm. ..

<Comparative example 4>
The sealant film 3 contains an ethylene-propylene random copolymer, 1000 ppm of erucic acid amide (lubricant), and 2000 ppm of silica particles (average particle size 1.0 μm; incompatible particles), and has a thickness of 30 μm. An exterior material for a power storage device was obtained in the same manner as in Example 1 except that a non-stretched film (single layer) made of a resin was used.

<Comparative example 5>
As the sealant film 3, a heat fusion having 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 a power storage device was obtained in the same manner as in Example 1 except that a non-stretched film (single layer) was used.

<Comparative Example 6>
The thickness of the first heat-sealing resin layer 7 was changed from 4.5 μm to 10 μm, the thickness of the second heat-sealing resin layer 8 was changed to 10 μm, and the thickness of the third heat-sealing resin layer 9 was changed to 10 μm. Except that the thickness of 4.5 μm was changed to 10 μm and an ethylene-propylene random copolymer was used as the resin constituting the second heat-sealing resin layer 8 instead of the ethylene-propylene block copolymer. An exterior material for a power storage device was obtained in the same manner as in Example 1.

<Comparative Example 7>
As the incompatible particles, an exterior material for a power storage device was obtained in the same manner as in Example 1 except that silica particles having an average particle diameter of 0.2 μm were used instead of silica particles having an average particle diameter of 1.0 μm. ..

<Comparative Example 8>
As the incompatible particles, an exterior material for a power storage device was obtained in the same manner as in Example 1 except that silica particles having an average particle diameter of 5.0 μm were used instead of silica particles having an average particle diameter of 1.0 μm. ..

<Measurement method of arithmetic mean height>
The arithmetic mean average height (Sa) of the surface 7a of the first heat-sealing resin layer (innermost layer) 7 of the exterior material for each power storage device obtained as described above was determined as follows. That is, using the scanning white interference microscope VS1330 manufactured by Hitachi High-Technologies Corporation, the objective lens: 5x, the intermediate lens: 1x, and the camera: 1/3 "with a 5x single field of view (938mm x 703mm). , The arithmetic average height (Sa) of the surface 7a of the innermost layer 7 of the exterior material 1 was determined.

The exterior materials for each power storage device obtained as described above were evaluated based on the following evaluation methods. The results are shown in Table 3.

<Moldability evaluation method>
Using a straight mold with no molding depth, the exterior material was deep-drawn and one-stage molded under the following molding conditions, and each molding depth (9.0 mm, 8.5 mm, 8.0 mm, 7.5 mm, 7. Moldability was evaluated for each 0 mm, 6.5 mm, 6.0 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). The maximum molding depth (mm) capable of performing good molding with no pinholes generated at the corners was investigated, and the moldability was evaluated based on the following criteria. The presence or absence of pinholes was examined by visually observing the presence or absence of transmitted light transmitted through the pinholes.
(Molding condition)
Molding mold: Punch: 33.3 mm x 53.9 mm, Die: 80 mm x 120 mm, Corner R: 2 mm, Punch R: 1.3 mm, Die R: 1 mm
Wrinkle pressing pressure: Gauge pressure: 0.475 MPa, actual pressure (calculated value): 0.7 MPa
Material: SC (carbon steel) material, punch R only chrome plated.
(criterion)
"◎" ... The maximum molding depth at which pinholes and cracks do not occur is 7.0 mm or more. "○" ... The maximum molding depth at which pinholes and cracks do not occur is 5.0 mm or more and less than 7.0 mm. The maximum molding depth at which pinholes and cracks do not occur is less than 5.0 mm.

<Evaluation method for white turbidity prevention>
Prepare the sealant film 3 alone before adhesively laminating it on the aluminum foil 4, and use a haze meter (“HM-150” manufactured by Murakami Color Technology Research Institute Co., Ltd.) in accordance with JIS K7136-2000 to achieve the haze rate (haze rate). ) Was measured and evaluated based on the following criteria.
(criterion)
“◎”… Haze rate is less than 3% (excellent in visibility of defect inspection such as delamination)
“○”… Haze rate is 3% or more and less than 10% (good visibility of defect presence inspection such as delamination)
“X”: The haze rate is 10% or more (the visibility of defect inspection such as delamination is poor).

<Presence / absence of white powder (prevention of white powder appearance) evaluation method>
After cutting out a rectangular test piece of 600 mm in length × 100 mm in width from the exterior material for each power storage device, the obtained test piece is placed on a test table with the inner layer 3 surfaces (that is, the innermost layer surface 7a) facing up. A SUS weight (mass 1.3 kg, ground plane size 55 mm x 50 mm) with a black waste cloth wrapped around the test piece and having a black surface is placed on the upper surface of the test piece. By pulling the weight in the horizontal direction parallel to the upper surface of the test piece at a tensile speed of 4 cm / sec, the weight was pulled and moved over a length of 400 mm in contact with the upper surface of the test piece. The waste (black) on the contact surface of the weight after the tensile movement was visually observed, and the one where white powder was prominently generated on the surface of the waste (black) was marked with "x", and only a small amount of white powder was generated. Those with almost no white powder or no white powder were marked with "○". As the black waste cloth, TRUSCO's "Static electricity removal sheet S SD2525 3100" was used.

As is clear from the table, the exterior materials for power storage devices of Examples 1 to 21 of the present invention have a maximum molding depth of 5.0 mm or more, can ensure good moldability and suppress white turbidity in the exterior materials. As a result, the visibility of the inspection for 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, any one of the moldability, the white turbidity prevention property, and the white powder expression prevention property was poorly evaluated.

As a specific example, the exterior material for a power storage device according to the present invention is, for example,
-Used as an exterior material for various power storage devices such as power storage devices such as lithium secondary batteries (lithium ion batteries, lithium polymer batteries, etc.), lithium ion capacitors, and electric double-layer capacitors. Further, the power storage device according to the present invention includes an all-solid-state battery in addition to the power storage device exemplified above.

1 ... Exterior material for power storage device 2 ... Base material layer (outer layer)
3 ... Heat-sealing resin layer (inner layer)
4 ... Metal leaf layer 7 ... First heat-sealing resin layer (innermost layer)
8 ... 2nd heat-sealing resin layer 9 ... 3rd heat-sealing resin layer 10 ... Exterior case 15 ... Exterior member 30 ... Power storage device 31 ... Power storage device main body

Claims (8)

An exterior material for a power storage device including a base material layer as an outer layer, a heat-sealing resin layer as an inner layer, and a metal foil layer arranged between both layers.
The heat-sealing resin layer is formed by laminating a first heat-sealing resin layer forming the innermost layer of the exterior material and a second surface of the first heat-sealing resin layer on the metal leaf layer side. The heat-sealing resin layer and the third heat-sealing resin layer laminated on the surface of the second heat-sealing resin layer on the metal leaf layer side or arranged on the metal leaf layer side are provided. Consists of three or more layers including
The first heat-sealing resin layer is incompatible with a random copolymer containing propylene and other copolymerization components other than propylene as copolymerization components, a lubricant, and an average particle size of 0.5 μm to 4 μm. The first resin composition containing particles, the content of the random copolymer in the first resin composition is 50% by mass or more, and the incompatible particles in the first resin composition. The content is in the range of 1000 ppm to 6000 ppm and
The second heat-sealing resin layer comprises a block copolymer containing propylene as a copolymerization component and other copolymerization components other than propylene, and incompatible particles having an average particle size 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 is 50% by mass or more. More than 0 ppm and less than 100 ppm,
The third heat-sealing resin layer comprises a third resin composition containing a random copolymer containing propylene as a copolymerization component and other copolymerization components other than propylene, and the third resin composition. An exterior material for a power storage device, characterized in that the content of the random copolymer is 50% by mass or more. An exterior material for a power storage device including a base material layer as an outer layer, a heat-sealing resin layer as an inner layer, and a metal foil layer arranged between both layers.
The heat-sealing resin layer is formed by laminating a first heat-sealing resin layer forming the innermost layer of the exterior material and a second surface of the first heat-sealing resin layer on the metal leaf layer side. The heat-sealing resin layer and the third heat-sealing resin layer laminated on the surface of the second heat-sealing resin layer on the metal leaf layer side or arranged on the metal leaf layer side are provided. Consists of three or more layers including
The first heat-sealing resin layer is incompatible with a random copolymer containing propylene and other copolymerization components other than propylene as copolymerization components, a lubricant, and an average particle size of 0.5 μm to 4 μm. The first resin composition containing particles, the content of the random copolymer in the first resin composition is 50% by mass or more, and the incompatible particles in the first resin composition. The content is in the range of 1000 ppm to 6000 ppm and
The second heat-sealing resin layer comprises a second resin composition containing a block copolymer containing propylene as a copolymerization component and other copolymerization components other than propylene, and not containing incompatible particles. , The content of the block copolymer in the second resin composition is 50% by mass or more.
The third heat-sealing resin layer comprises a third resin composition containing a random copolymer containing propylene as a copolymerization component and other copolymerization components other than propylene, and the third resin composition. An exterior material for a power storage device, characterized in that the content of the random copolymer is 50% by mass or more. The third resin composition is a composition that does not contain incompatible particles, or a composition that contains incompatible particles having an average particle size of 0.5 μm to 4 μm in an amount of more than 0 ppm and 6000 ppm or less. 2. The exterior material for a power storage device according to 2. The exterior material for a power storage device according to any one of claims 1 to 3, wherein the arithmetic mean height (Sa) of the inner surface of the first heat-sealing resin layer is 50 nm to 200 nm. 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 a power storage device according to any one of claims 1 to 4. The heat-sealing resin layer comprises the first heat-sealing resin layer, the second heat-sealing resin layer, and the third heat-sealing resin layer.
The exterior for a power storage device according to any one of claims 1 to 5, wherein the thickness of the first heat-sealing resin layer is 5% to 30% of the total thickness of the heat-sealing resin layer. Material. An exterior case for a power storage device made of a molded body of the exterior material for the power storage device according to any one of claims 1 to 6. Power storage device body and
It is provided with one or two types of exterior members selected from the group consisting of the exterior material for a power storage device according to any one of claims 1 to 6 and the exterior case for a power storage device according to claim 7.
A power storage device characterized in that the power storage device main body is covered with the exterior member.

Images