TWI760335B - Exterior material for electrical storage device and method for producing the same - Google Patents

Abstract

The present invention provides a sealing film for an exterior material of a power storage device, which comprises a first unstretched film layer 7 forming the innermost layer of the exterior material, and a surface on one side of the first unstretched film layer. The laminated second non-stretch film layer 8 is composed of a laminate of two or more layers; the first non-stretch film layer 7 includes a random copolymer containing propylene as a copolymer component and other copolymer components other than propylene, and lubricant; the aforementioned second non-stretched film layer 8 contains a block copolymer containing propylene as a copolymerization component and other copolymerized components other than propylene, and a lubricant; the aforementioned first non-stretched film layer 7 lubrication The concentration of the agent is 200 ppm to 3000 ppm, and the concentration of the lubricant of the second non-stretched film layer 8 is 500 ppm to 5000 ppm. With this configuration, the reduction in the amount of lubricant deposited on the surface of the exterior material can be suppressed, and the moldability is excellent, and white powder is less likely to appear on the surface.

Description

Exterior material for electrical storage device and method for producing the same

The present invention relates to a battery or capacitor for use in portable devices such as smartphones and touch panels, as well as batteries or capacitors for use in hybrid vehicles, electric vehicles, wind power generation, solar power generation, and nighttime power storage devices. A sealing film used in the material, and a method for producing an exterior material for an electrical storage device using the sealing film.

In recent years, with the thinning and weight reduction of portable devices such as smartphones and touch panel terminals, the external packaging of power storage devices such as lithium-ion batteries, lithium-polymer batteries, lithium-ion capacitors, and electric double-layer capacitors has been carried out. In place of traditional metal cans, a laminate consisting of a heat-resistant resin layer/adhesive layer/metal foil layer/adhesive layer/thermoplastic resin layer (inside sealing layer) is used. In addition, the number of power sources for electric vehicles and the like, large-scale power sources for power storage, capacitors, and the like are also increased by the laminates (exterior materials) configured as described above. The above-mentioned laminated body is formed into a three-dimensional shape such as a roughly rectangular parallelepiped shape by bulging or deep drawing. By forming such a three-dimensional shape, an accommodation space for accommodating the main body of the power storage device can be secured.

In order to form such a three-dimensional shape into a good shape without pinholes or cracks, it is required to improve the surface smoothness of the inner sealing layer. To improve the surface smoothness of the inner sealing layer and To ensure good formability, a laminate for a battery container is proposed, which is to laminate an exterior resin film, a first adhesive layer, a chemically-treated aluminum foil, a second adhesive layer, and a sealing film in this order; the sealing film is α- It is composed of a random copolymer of propylene and α-olefin with an olefin content of 2 to 10% by weight, and contains a lubricant of 1000 to 5000 ppm (refer to Patent Document 1).

【Prior technical literature】 【Patent Literature】

[Patent Document 1] Japanese Patent Laid-Open No. 2003-288865

However, in the above-mentioned conventional technology, it is difficult to control the precipitation amount of the surface lubricant during the heating and holding time or during the storage period in the production process of the exterior material (laminated material). Although the smoothness during molding is good, the lubricant is excessive on the surface. When the exterior material is formed, the lubricant adheres and accumulates on the molding surface of the molding die to generate white powder (white powder generated from the lubricant). In such a state that the white powder adheres and accumulates on the molding surface, it is difficult to perform good molding. Therefore, it is necessary to clean and remove the white powder every time the white powder adheres and accumulates. This cleaning and removal of the white powder increases the productivity of the exterior material. lowering problem.

Of course, if the amount of lubricant added (lubricant content) is reduced, the adhesion and accumulation of white powder can be suppressed, but in this case, the amount of precipitation of the surface lubricant is insufficient and the formability is deteriorated. question. With such a conventional technique, it is difficult to achieve both excellent formability and suppression of the occurrence of white powder on the surface of the exterior material.

The present invention has been made in view of the background of the related art, and an object of the present invention is to provide a sealing film for an exterior material of an electrical storage device, an exterior material for an electrical storage device, and a manufacturing method thereof, which can suppress the slippage deposited on the surface of the exterior material. The dosage is reduced, and while ensuring good smoothness and excellent formability, white powder is difficult to appear on the surface.

In order to achieve the aforementioned objects, the present invention provides the following technical means.

[1] A sealing film for an exterior material of an electrical storage device, characterized by comprising a first non-stretchable film layer, and a second non-stretched film layer including an area layer on one side of the first non-stretched film layer. The above-mentioned first non-stretch film layer forms the innermost layer of the exterior material; the above-mentioned first non-stretch film layer contains propylene as a copolymerization component and other copolymers other than propylene A random copolymer of components, and a lubricant; the aforementioned second unstretched film layer comprising a block copolymer containing propylene as a copolymerized component and a copolymerized component other than propylene, and a lubricant; the aforementioned first unstretched film layer The content concentration of the lubricant of the thin film layer is 200 ppm to 3000 ppm, and the content concentration of the lubricant of the second non-stretched thin film layer is 500 ppm to 5000 ppm.

[2] A sealing film for an exterior material of an electrical storage device, characterized by comprising a second non-stretched film layer and an area layer on one side of the second non-stretched film layer; A first unstretched film layer and a laminate of three or more layers of the first unstretched film layer on the other side of the second unstretched film layer; the first unstretched film on either side layer, which forms the innermost layer of the exterior material; the aforementioned first non-stretch film layer, comprising a random copolymer containing propylene as a copolymerized component and other copolymerized components other than propylene, and a lubricant; the aforementioned second The non-stretching film layer includes a block copolymer containing propylene as a copolymerization component and other copolymerization components other than propylene, and a lubricant; the lubricant in the first non-stretching film layer contains a concentration of 200ppm to 3000ppm, The content concentration of the lubricant of the second non-stretched film layer is 500 ppm to 5000 ppm.

[3] The sealing film for an exterior material of an electrical storage device according to 1 or 2 above, wherein the lubricant content of the second non-stretch film layer is at a concentration of the first non-stretch forming the innermost layer of the exterior material. The lubricant in the film layer contains 0.5 to 5 times the concentration.

[4] An exterior material for a power storage device, characterized by comprising: an inner sealing layer composed of the sealing film described in any one of the preceding items 1 to 3, and a metal foil laminated on one side of the inner sealing layer layer.

[5] An exterior material for a power storage device, characterized by comprising: a heat-resistant resin layer as an outer layer, an inner sealing layer composed of the sealing film described in any one of the preceding items 1 to 3, and an inner sealing layer arranged on two Metal foil layers between layers.

[6] The exterior material for an electricity storage device according to the above item 4 or 5, wherein the amount of lubricant present on the surface of the first non-stretched thin film layer forming the innermost layer of the exterior material is 0.1 μg/cm ² ~1.0 μg/cm ² range.

[7] An exterior case for a power storage device, comprising a molded body of an exterior material as described in any one of Items 4 to 6 above.

[8] A method of manufacturing an exterior material for an electrical storage device, characterized by comprising: a preparation step of preparing the sealing film as described in any one of 1 to 3 above through a first adhesive layer, and a layer of metal foil body; an aging step is to heat-treat the above-mentioned laminated body to obtain an exterior material for an electrical storage device.

[9] The method for producing an exterior material for an electrical storage device according to the above item 8, wherein the first adhesive is a thermosetting adhesive.

[10] A method of manufacturing an exterior material for a power storage device, comprising: a preparation step of laminating a heat-resistant resin film on one side of a metal foil via a second adhesive and on the other side of the metal foil The side surface is interposed in the first adhesive agent, and the laminated body composed of the sealing film described in any one of the above 1 to 3 is laminated; the aging step is to heat-treat the above laminated body to obtain an exterior material for an electrical storage device.

[11] The method for producing an exterior material for an electrical storage device according to the above item 10, wherein the first adhesive is a thermosetting adhesive, and the second adhesive is a thermosetting adhesive.

[12] The method for producing an exterior material for an electrical storage device as described in any one of the above 8 to 11, wherein the first layer is present in the innermost layer of the exterior material for an electrical storage device obtained by heat treatment The amount of lubricant on the surface of the non-stretched film layer is in the range of 0.1 μg/cm ² to 1.0 μg/cm ² .

The inventions of [1] and [2] can suppress the decrease in the amount of lubricant existing (precipitated) on the surface of the exterior material (the surface 7a of the innermost layer of the inner sealing layer) after the aging treatment, and can ensure good quality during molding It has excellent smoothness and formability, and at the same time, it is difficult for white powder to appear on the surface of the exterior material (surface 7a of the innermost layer of the inner sealing layer). In addition, the amount of the lubricant present on the surface of the exterior material after the aging treatment does not change through the thermal history during transportation or storage, so that the exterior material with stable and excellent formability can be provided.

According to the invention of [3], the lubricant content of the second unstretched film layer is 0.5 to 5 times the concentration of the lubricant of the first unstretched film layer forming the innermost layer of the exterior material. During the aging treatment, by making it 0.5 times or more, the interface (the two films) of the lubricant concentration gradient of the lubricant from the innermost first non-stretch film layer 7 to the second non-stretch film layer 8 can be suppressed. The interface of the layers 7, 8) concentrates the movement; by making it 5 times or less, the lubricant concentration gradient of the lubricant from the second non-stretch film layer 8 to the innermost first non-stretch film layer 7 can be suppressed. The interface (the interface between the two thin film layers 7, 8) concentrates the movement, and the amount of lubricant existing in the first non-stretch thin film layer 7a, which is the innermost layer of the exterior material after the aging treatment, can be controlled to 0.1 μg/cm ² ~ 1.0μg/cm ² range.

According to the inventions of [4] and [5], it is possible to provide an exterior material for an electrical storage device, which can suppress a decrease in the amount of lubricant existing (precipitated) on the surface of the exterior material (surface 7a of the innermost layer of the inner sealing layer). It can ensure good smoothness and excellent formability during molding, and at the same time, white powder is difficult to appear on the surface of the exterior material (surface 7a of the innermost layer of the inner sealing layer).

In addition, in the invention of [5], since the heat-resistant resin layer is further provided as the outer layer, the insulation properties of the inner sealing layer and the opposite side of the metal foil layer can be sufficiently ensured, and the physical strength and impact resistance of the exterior material can be improved.

The invention of [6] can provide an exterior material for an electrical storage device, which exhibits better smoothness during molding, can ensure further favorable moldability, and can prevent the occurrence of white powder.

According to the invention of [7], it is possible to provide an outer case for a power storage device, which is formed by a good molding, and which makes it difficult for white powder to appear on the surface of the outer case (the surface of the innermost layer of the inner sealing layer).

According to the inventions of [8] to [11], it is possible to manufacture an exterior material for an electrical storage device, which can suppress the decrease in the amount of lubricant existing (precipitated) on the surface of the exterior material (the surface 7a of the innermost layer of the inner sealing layer) and also It can ensure good smoothness and formability during molding, and at the same time, white powder is difficult to appear on the surface of the exterior material (surface 7a of the innermost layer of the inner sealing layer).

In addition, in the inventions of [10] and [11], since the heat-resistant resin layer is further provided as the outer layer, the insulation properties of the inner sealing layer and the opposite side of the metal foil layer can be sufficiently ensured, and the physical strength and Impact resistance.

According to the invention of [12], since the amount of lubricant present on the surface of the innermost layer is in the range of 0.1 μg/cm ² to 1.0 μg/cm ² , it is possible to produce better smoothness during molding, and to ensure further The exterior material for electric storage devices has good formability and can prevent the occurrence of white powder. In addition, the amount of lubricant (0.1 μg/cm ² to 1.0 μg/cm ² ) present on the surface of the obtained exterior material for an electrical storage device does not change through the thermal history during transportation or storage, so that it is possible to provide Stable and excellent formability exterior material.

1: Exterior materials for power storage devices

2: Heat-resistant resin layer (outer layer)

3: Inner sealing layer (sealing film) (inner layer)

4: Metal foil layer

5: Second adhesive layer (outer adhesive layer)

6: 1st adhesive layer (inner adhesive layer)

7: 1st non-stretch film layer (innermost layer)

7a: The surface of the first unstretched film layer (the surface of the innermost layer of the exterior material)

8: The second non-stretching film layer

9: 1st unstretched film layer (metal foil layer side)

10: Outer case (molded body) for power storage device

15: Exterior parts

30: Power storage device

31: Power storage device body

Fig. 1 is a cross-sectional view showing an embodiment of an exterior material for an electrical storage device according to the present invention.

Fig. 2 is a cross-sectional view showing another embodiment of the exterior material for an electrical storage device of the present invention.

Fig. 3 is a cross-sectional view showing an embodiment of the power storage device of the present invention.

Fig. 4 is a perspective view showing a separated state before heat-sealing the main body of the electric storage device and the outer casing (molded body in a three-dimensional shape) constituting the exterior material (planar) of the electric storage device of Fig. 3 .

FIG. 1 shows the first embodiment of the sealing film for the exterior material of the electrical storage device of the present invention. The above-mentioned sealing film 3 is composed of a first non-stretch film layer 7 which forms the innermost layer of the exterior material 1 and a second non-stretch film layer 8 which is an area layer on one side of the first non-stretch film layer 7. The above-mentioned first unstretched film layer 7 contains a random copolymer containing propylene as a copolymerization component and other copolymerization components other than propylene, and a lubricant; the aforementioned second unstretched film layer 8, A block copolymer containing propylene as a copolymerization component and other copolymerization components other than propylene, and a lubricant are included.

Moreover, the 2nd Embodiment of the sealing film for exterior materials of the electrical storage device of this invention is shown in FIG. 2. FIG. The sealing film 3 is composed of a first unstretched film layer 7 including a second unstretched film layer 8, an area layer on one side of the second unstretched film layer, and a second unstretched film layer on the other side of the second unstretched film layer. The area layer on one side is composed of a laminate of the first unstretched film layer 9; the first unstretched film layer 7 forms the innermost layer of the exterior material 1; the first unstretched film layers 7, 9 , including a random copolymer containing propylene as a copolymerization component and other copolymerization components other than propylene, and a lubricant; the aforementioned second non-stretching film layer 8 includes as a copolymerization component propylene and other copolymerization components other than propylene Block copolymers of copolymer components, and lubricants composition.

The aforementioned first non-stretched film layers 7 and 9 include a random copolymer containing "propylene" as a copolymerization component and "other copolymerization components other than propylene", and a lubricant. Regarding the random copolymer, the "other copolymerization components other than propylene" are not particularly limited, and examples thereof include ethylene, 1-butene, 1-hexene, 1-pentene, and 4methyl-1-pentene. Olefin components such as alkene, and butadiene, etc.

The second non-stretched film layer 8 includes a block copolymer containing "propylene" as a copolymerization component and "other copolymerization components other than propylene", and a lubricant. Regarding the above-mentioned block copolymer, the above-mentioned "other copolymerization components other than propylene" are not particularly limited, and examples thereof include ethylene, 1-butene, 1-hexene, 1-pentene, and 4methyl-1- Olefin components such as pentene, and butadiene, etc.

In addition, in the sealing film 3 of the present invention, it is important that the concentration of the lubricant in the first non-stretched film layers 7 and 9 is set at 200 ppm to 3000 ppm; the concentration of the lubricant in the second non-stretched film layer 8 is set at 500ppm~5000ppm. By satisfying such a condition, the lubricant present in the first non-stretched film layer 7 can be suppressed from moving into the second non-stretched film layer 8 during the aging treatment to harden the adhesive, so that it is possible to secure the outer covering material. The amount of lubricant precipitated on the surface (the surface 7a of the innermost first non-stretched film layer) can ensure good smoothness during the molding of the exterior material and obtain excellent formability. If the concentration of the lubricant in the first unstretched film layer 7 is less than 200 ppm, the amount of lubricant present on the surface 7a of the innermost layer becomes insufficient after the aging treatment to harden the adhesive, and excellent formability cannot be obtained. ; If it exceeds 3000ppm, after the aging treatment to harden the adhesive, white powder will be produced significantly on the surface 7a of the innermost layer, which must be The problem of reduced productivity due to the work of cleaning and removal of white powder, and the problem of reduced adhesion to the metal foil layer or easy contamination of the electrolyte when used as an exterior material. In addition, if the concentration of the lubricant in the second unstretched film layer 8 is less than 500 ppm, when the aging treatment is performed to harden the adhesive, the innermost layer from the first unstretched film layer 7 to the second unstretched film layer is 8. The lubricant is easy to move, and the amount of lubricant on the innermost surface 7a becomes insufficient, and the smoothness during molding becomes poor; if it exceeds 5000 ppm, during the aging treatment to harden the adhesive, there will be no extension from the second The lubricant from the film layer 8 to the first non-stretched film layer 7 and 9 is easy to move, causing white powder pollution in the device during production. When used as an exterior material, it is easy to reduce the adhesion force with the metal foil layer or the pollution of the electrolyte.

The concentration of the lubricant in the first non-stretched thin film layers 7 and 9 is preferably in the range of 300 ppm to 2700 ppm, more preferably in the range of 800 ppm to 1200 ppm. In addition, the concentration of the lubricant in the second non-stretched film layer 8 is preferably in the range of 700 ppm to 4500 ppm, more preferably in the range of 800 ppm to 2700 ppm.

In the sealing film 3 of the present invention, the lubricant content of the second non-stretch film layer 8 is 0.5 of the lubricant content of the first non-stretch film layer 7 that forms the innermost layer of the exterior material 1 . The composition of 5 times to 5 times is better. By making it 0.5 times or more, the lubricant concentration gradient of the lubricant from the innermost first non-stretch film layer 7 to the second non-stretch film layer 8 can be suppressed during the aging treatment of the hardening adhesive. The concentrated movement of the interface (the interface between the two thin film layers 7, 8), the amount of lubricant existing on the surface 7a of the innermost layer becomes more sufficient to obtain excellent formability; During the aging treatment of the agent, the lubrication of the lubricant from the second non-stretch film layer 8 to the innermost first non-stretch film layer 7 can be suppressed. The concentrated movement of the interface of the lubricant concentration gradient (the interface between the two thin film layers 7 and 8 ) can sufficiently suppress the fluctuation of the lubricant content of the innermost first non-stretched thin film layer 7 . The concentration of the lubricant in the second non-stretched thin film layer 8 is 1.0 to 3.0 times the concentration of the lubricant in the first non-stretched thin film layer 7 that forms the innermost layer of the exterior material 1 . The composition is better.

The aforementioned lubricant is not particularly limited, and examples thereof include saturated fatty acid amides, unsaturated fatty acid amides, substituted amides, hydroxymethyl amides, saturated fatty acid diamides, unsaturated fatty acid diamides, and fatty acid esters. amides, aromatic bisamides, etc. The above-mentioned lubricants may be used alone or in combination of a plurality of types.

The said saturated fatty acid amide is not particularly limited, and examples thereof include lauric acid amide, palmitic acid amide, stearic acid amide, behenyl amide, hydroxystearic acid amide, and the like. The unsaturated fatty acid amide is not particularly limited, and examples thereof include oleamide, erucamide, and the like.

The above-mentioned substituted amide is not particularly limited, and examples thereof include N-oleyl palmitamide, N-stearyl stearate, N-stearyl oleamide, and N-oleyl stearyl amide. Fatty acid amide, N-stearyl erucamide, etc. In addition, the aforementioned hydroxymethyl amide is not particularly limited, for example, hydroxymethyl stearic acid amide and the like.

The aforementioned saturated fatty acid bisamide is not particularly limited, and examples thereof include methylenebisstearate, ethylenebiscaprate, ethylenebislaurate, and ethylenebisstearyl. Acid amide, ethylene bis-hydroxystearic acid amide, ethylene bis-docosamide, hexamethylene bis-docosamide, hexamethylene bis-docosamide, hexamethylene bis-docosamide Methylene hydroxystearic acid amide, N,N'-distearyl adipamide amide, N,N'-distearyl sebacate amide, etc.

The above-mentioned unsaturated fatty acid bisamide is not particularly limited, and for example, submerged Ethylbisoleamide, ethylenebiserucamide, hexamethylenebisoleamide, N,N'-dioleyl sebacate, etc.

Although the said fatty acid ester amide is not specifically limited, For example, stearyl amide ethyl stearate etc. are mentioned. The above-mentioned aromatic bisamide is not particularly limited, and examples thereof include m-m-isophenyl bis-stearate, m-m-m-phenyl bishydroxystearate, N,N'-distearate m-phenylene Diformic acid amide and so on.

The thickness of the aforementioned sealing film 3 is preferably set at 10 μm˜100 μm. If it is 10 μm or more, the generation of pinholes can be sufficiently prevented, and if it is set to 100 μm or less, the amount of resin used can be reduced, thereby achieving cost reduction.

In the case where the above-mentioned sealing film 3 adopts the two-layer laminated structure of FIG. 1, the ratio of the thickness of the two layers is set at the thickness of the first unstretched film layer 7/the thickness of the second unstretched film layer 8=5~90/ The range of 95 to 10 is preferable, and the range of the thickness of the first non-stretched film layer 7 / the thickness of the second non-stretched thin film layer 8 = 5 to 40/95 to 60 is particularly preferable.

In addition, in the case where the aforementioned sealing film 3 adopts the three-layer structure of FIG. 2, the ratio of the thickness of the three layers is set at the thickness of the first unstretched film layer 7/the thickness of the second unstretched film layer 8/the first unstretched film layer 8 The thickness of the non-stretching film layer 9 is preferably in the range of 5~45/90~10/5~45, wherein the thickness of the first non-stretching thin film layer 7 / the thickness of the second non-stretching thin film layer 8 / the first The thickness of the non-stretched film layer 9 = 5~20/90~60/5~20 is particularly preferred.

The first non-stretching film layer 7 forming the innermost layer may further contain an anti-blocking agent. In addition, on the side of the first non-stretched film layer 7 and the metal foil layer that form the innermost layer Both of the first unstretched film layers 9 may contain an anti-blocking agent. The aforementioned anti-blocking agent is not particularly limited, and examples thereof include silica particles, acrylic resin particles, aluminum silicate particles, and the like. The particle size of the aforementioned anti-blocking agent is preferably in the range of 0.1 μm to 10 μm in average particle size, and more preferably in the range of 1 μm to 5 μm in average particle size. When the anti-blocking agent is contained in the first non-stretched film layers 7 and 9, the content concentration is preferably set at 100 ppm to 5000 ppm.

By containing the anti-blocking agent (particles) in the first non-stretching film layer 7 forming the innermost layer, microscopic protrusions are formed on the surface 7a of the innermost layer 7 and the contact area between the films can be reduced, and sealing can be suppressed. adhesion between films. In addition, by containing an anti-blocking agent (particles) together with the aforementioned lubricant, the smoothness during the aforementioned molding can be further improved.

The aforementioned sealing film 3 is preferably produced by a molding method such as multilayer extrusion molding, inflation molding, and T-die casting film molding.

The exterior material 1 for an electricity storage device of the present invention is produced by using the sealing film having the above-mentioned configuration. A laminated body of the structure in which the sealing film 3 of the above-mentioned first embodiment and the metal foil 4 are laminated through the first adhesive agent (inside adhesive agent) 6 is prepared. At this time, the second unstretched film layer 8 of the sealing film 3 is connected to the first adhesive 6 (see FIG. 1 ). Next, by heat-processing the obtained layered body (by performing aging treatment), the exterior material 1 for an electrical storage device of the present invention having the structure shown in FIG. 1 can be obtained.

In addition, a laminate is prepared, which is configured by laminating a heat-resistant resin film (outer layer) 2 on one surface of the metal foil 4 with a second adhesive (outer adhesive) 5 interposed therebetween, and on the other side of the metal foil 4 The sealing film 3 of the above-mentioned second embodiment is laminated on the first adhesive agent (inside adhesive agent) 6 on the surface. At this time, the first unstretched film layer 9 of the sealing film 3 is connected to the first Adhesive (inside adhesive) 6 (refer to FIG. 2 ). That is, the first unstretched film layer 7 on the other side of the sealing film 3 forms the innermost layer (see FIG. 2 ). Next, by heat-processing the obtained laminated body (by performing an aging process), the exterior material 1 for electric storage devices of this invention comprised as shown in FIG. 2 can be obtained.

The said 1st adhesive agent (inner side adhesive agent) 6 is not specifically limited, For example, a thermosetting adhesive agent etc. are mentioned. In addition, the said 2nd adhesive agent (outer side adhesive agent) 5 is not specifically limited, For example, a thermosetting adhesive agent etc. are mentioned. Although the said thermosetting adhesive agent is not specifically limited, For example, an olefin type adhesive agent, an epoxy resin type adhesive agent, an acrylic type adhesive agent, etc. are mentioned.

The heating temperature of the above-mentioned aging treatment is preferably set below 65°C, and it is set at 35°C to 45°C from the viewpoint of the degree of hardening of the adhesive and the maintenance of an appropriate amount of lubricant present on the surface 7a of the exterior material. ℃ is better. In addition, regarding the heating time of the above-mentioned aging treatment, since the curing time varies depending on the type of adhesive, it is sufficient to combine the type of adhesive to obtain sufficient bonding strength. It is better to take as short a time as possible to obtain sufficient bonding strength.

In the exterior material 1 for an electrical storage device of the present invention obtained by such aging treatment, a heat-resistant resin layer (outer layer) is laminated on one side of the metal foil layer 4 via a second adhesive (outer adhesive) 5 2. It is integrated, and the inner sealing layer (sealing film layer) (inner layer) 3 is integrally laminated on the other side of the metal foil layer 4 through a first adhesive (inner adhesive) 6 ( Refer to Figures 1 and 2).

In the sealing film 3 used in the production of the outer casing 1 for a power storage device obtained by the above-mentioned aging treatment, the content concentration of the lubricant in the first non-stretching film layer is set at 200 ppm to 3000 ppm, and the second non-stretching film layer is set at a concentration of 200 ppm to 3000 ppm. The concentration of the lubricant in the thin film layer is set at 500 ppm to 5000 ppm, so that the amount of lubricant present on the surface 7a of the first non-stretched thin film layer 7 which is the innermost layer of the exterior material 1 for an electrical storage device after the aging treatment can be controlled at The range of 0.1μg/cm ² ~1.0μg/cm ² . Therefore, the obtained exterior material 1 for a power storage device can suppress the decrease in the amount of lubricant existing (precipitated) on the surface (the surface 7a of the innermost layer of the inner sealing layer), thereby ensuring good smoothness during molding and molding While excellent in performance, white powder is difficult to appear on the surface of the exterior material (surface 7a of the innermost layer of the inner sealing layer).

In the exterior material 1 for a power storage device, the coefficient of kinetic friction of the surface 7a of the first non-stretched film layer (innermost layer) 7 is preferably in the range of 0.10 to 0.50. By making it 0.50 or less, the smoothness can be improved and good formability can be ensured, and when it is 0.10 or more, the outflow amount of the lubricant to the surface 7a of the innermost layer can be reduced.

The exterior material 1 for electrical storage devices of this invention is used for the exterior material for lithium ion batteries, for example. The aforementioned exterior material 1 for an electrical storage device may be used as an exterior material without molding, or may be used as an exterior case 10 by, for example, deep drawing molding, bulging molding, or the like (see FIG. 4 ).

In the exterior material 1 for a power storage device of the present invention, the inner sealing layer (inner layer) 3 also has excellent chemical resistance against highly corrosive electrolytes used in lithium ion batteries, etc., and is responsible for providing the exterior material function of heat sealing.

In addition, the heat-resistant resin layer (base material layer; outer layer) 2 is not an essential constituent layer, but is used on the other side (surface opposite to the inner sealing layer) of the metal foil layer 4 between the first 2. The adhesive layer (outer adhesive layer) 5. The configuration of laminating the heat-resistant resin layer 2 is preferable (see FIGS. 1 and 2). By providing such a heat-resistant resin layer 2, it is possible to sufficiently secure the metal The insulating properties of the other side surface of the foil layer 4 (the surface opposite to the inner sealing layer) side can improve the physical strength and impact resistance of the exterior material 1 .

As the heat-resistant resin constituting the above-mentioned heat-resistant resin layer (substrate layer; outer layer) 2, a heat-resistant resin that does not melt at the heat-sealing temperature when the exterior material is heat-sealed is used. As the above-mentioned heat-resistant resin, it is preferable to use a heat-resistant resin having a melting point higher than that of the block copolymer constituting the second unstretched film layer 8 by 10° C. or more. A heat-resistant resin whose melting point of the segment copolymer is higher than the melting point of 20°C or more is particularly preferred.

The heat-resistant resin layer (outer layer) 2 is not particularly limited, and examples thereof include polyamide films such as nylon films, polyester films, and the like, and these stretched films are preferably used. Among them, the above-mentioned heat-resistant resin layer 2 uses a biaxially stretched polyamide film such as a biaxially stretched nylon film, a biaxially stretched polybutylene terephthalate (PBT) film, and a biaxially stretched polyethylene terephthalate film. Diester (PET) films or biaxially stretched polyethylene naphthalate (PEN) films are particularly preferred. Although the said nylon film is not specifically limited, For example, a 6 nylon film, a 6,6 nylon film, a MXD nylon film, etc. are mentioned. Further, the above-mentioned heat-resistant resin layer 2 may be formed as a single layer, or may be formed as a multi-layer composed of polyester film/polyamide film (multilayer composed of PET film/nylon film, etc.), for example.

The thickness of the heat-resistant resin layer (outer layer) 2 is preferably 2 μm to 50 μm. When using polyester film, the thickness is preferably 2μm~50μm; when using nylon film, the thickness is preferably 7μm~50μm. By setting it above the above-mentioned suitable lower limit value, sufficient strength of the exterior material can be ensured, and by setting it below the above-mentioned suitable upper limit value, the stress during forming such as bulging and drawing can be reduced and forming can be improved. sex.

In the exterior material 1 for an electric storage device of the present invention, the surface on the opposite side of the metal foil layer 4 of the heat-resistant resin layer (outer layer) 2 is attached to the first layer forming the innermost layer of the exterior material 1 for an electric storage device. 1. No lubricant contained in the stretch film 7. The adhesion lubricant migrates from the inner layer 3 by the contact with the surface 7a of the inner sealing layer 3 in the curled state when the outer casing material 1 for an electric storage device obtained by the curl lamination process is aged. The adhesion amount after the transfer is preferably in the range of 0.1 μg/cm ² to 0.8 μg/cm ² . When the adhesion amount is within such a range, the formability of the exterior material 1 for an electrical storage device can be improved. Among them, the adhesion amount after the transfer is more preferably in the range of 0.1 μg/cm ² to 0.6 μg/cm ² , and particularly preferably in the range of 0.15 μg/cm ² to 0.45 μg/cm ² . After the outer casing material 1 for an electric storage device is formed by deep drawing or the like, the transfer lubricant can be removed, or it can be retained, or it can be made to disappear naturally.

The aforementioned metal foil layer 4 has a function of imparting air barrier properties to the exterior material 1 to prevent the intrusion of oxygen or moisture. The metal foil layer 4 is not particularly limited, and examples thereof include aluminum foil, SUS foil (stainless steel foil), and copper foil. Among them, aluminum foil and SUS foil (stainless steel foil) are preferably used. The thickness of the aforementioned metal foil layer 4 is preferably 5 μm˜120 μm. By making it 5 μm or more, pinholes can be prevented during rolling during metal foil production, and by making it 120 μm or less, the stress during forming such as bulging and drawing can be reduced and formability can be improved. Among them, the thickness of the aforementioned metal foil layer 4 is more preferably 10 μm˜80 μm.

The aforementioned metal foil layer 4 is preferably subjected to chemical conversion treatment on at least the inner surface (the surface on the side of the inner sealing layer 3 ). By performing such a chemical conversion treatment, the corrosion of the surface of the metal foil due to the contents (electrolyte of the battery, etc.) can be sufficiently prevented. For example, the metal foil can be subjected to chemical conversion treatment by the following treatment. That is, for example, on the surface of the metal foil subjected to the degreasing treatment, after applying the aqueous solution of any one of the following 1) to 3), drying, and applying chemical conversion treatment: 1) An aqueous mixture solution containing phosphoric acid, chromic acid, and at least one compound selected from the group consisting of metal salts of fluorides and non-metallic salts of fluorides; 2) Containing phosphoric acid, selected from acrylic resins, chitosan An aqueous solution of a mixture of at least one resin selected from the group consisting of derivative resin and phenolic resin, and at least one compound selected from the group consisting of chromic acid and chromium (III) salt. 3) Compounds containing phosphoric acid, at least one resin selected from the group consisting of acrylic resins, chitosan derivative resins and phenol resins, and at least one selected from the group consisting of chromic acid and chromium (III) salts , and an aqueous solution of a mixture of at least one compound selected from the group consisting of metal salts of fluorides and non-metallic salts of fluorides.

For the aforementioned chemical film, the amount of chromium adhesion (per single side) is preferably 0.1 mg/m ² to 50 mg/m ² , and particularly preferably 2 mg/m ² to 20 mg/m ² .

The thickness of the second adhesive layer (outer adhesive layer) 5 is preferably set to 1 μm to 5 μm. Among them, it is particularly preferable that the thickness of the outer adhesive layer 5 is set to 1 μm to 3 μm from the viewpoint of thinning and weight reduction of the exterior material 1 .

The thickness of the first adhesive layer (inside adhesive layer) 6 is preferably set to 1 μm to 5 μm. Among them, from the viewpoint of thinning and weight reduction of the exterior material 1 , it is particularly preferable that the thickness of the inner adhesive layer 6 is set to 1 μm to 3 μm.

By molding (deep draw molding, bulging molding, etc.) of the exterior material 1 of the present invention, an exterior case (battery case, etc.) 10 (refer to FIG. 4 ) can be obtained. Moreover, the exterior material 1 of this invention can also be used directly without shaping|molding (refer FIG. 4).

FIG. 3 shows one embodiment of the power storage device 30 constructed using the exterior material 1 of the present invention. This power storage device 30 is a lithium-ion storage battery. As shown in FIGS. 3 and 4 , the present embodiment is constituted by an exterior case 10 obtained by molding the exterior material 1 , and an exterior member 15 of the planar exterior material 1 . In this way, the storage recessed portion of the outer casing 10 obtained by molding the outer casing 1 of the present invention accommodates a substantially rectangular parallelepiped-shaped power storage device body portion (electrochemical element, etc.) 31 ; Above, the unmolded exterior material 1 of the present invention is arranged so that its inner sealing layer 3 side is inside (lower side); the inner sealing layer 3 (the first non-stretched film layer 7 ) of the flat exterior material 1 and the inner sealing layer 3 (the first non-stretching film layer 7 ) of the flange portion (peripheral portion for sealing) 29 of the outer casing 10 are sealed by heat-sealing sealing to form the power storage device of the present invention 30 (see Figures 3 and 4). In addition, the inner surface of the accommodating recess of the outer casing 10 is formed with an inner sealing layer 3 (first non-stretching film layer 7), and the outer surface of the accommodating recess is formed with a heat-resistant resin layer (outer layer) 2 (refer to FIG. 4 ). .

In FIG. 3, 39 is the heat-sealing part to which the peripheral edge part of the said exterior material 1 and the flange part (peripheral edge part for sealing) 29 of the said exterior casing 10 are joined (fused). In addition, in the power storage device 30 described above, the leading end portion of the tab connected to the power storage device body portion 31 is led out of the exterior member 15, but it is omitted from the illustration.

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

The width of the heat-sealing portion 39 is preferably set to 0.5 mm or more. By making it 0.5 mm or more, sealing can be reliably performed. Wherein, the width of the aforementioned heat-sealing portion 39 is preferably set at 3 mm to 15 mm.

Moreover, in the above-mentioned embodiment, the exterior member 15 is constituted by the exterior case 10 obtained by molding the exterior material 1 and the planar exterior material 1 (see FIGS. 3 and 4 ), but there is no particular Limited to such a combination, for example, the exterior member 15 may be constituted by a pair of planar exterior members 1 , or may be constituted by a pair of exterior casings 10 .

【Example】

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

<Example 1>

A chemical conversion treatment liquid composed of phosphoric acid, polyacrylic acid (acrylic resin), chromium (III) salt compound, water, and ethanol was applied to both sides of the aluminum foil 4 with a thickness of 40 μm, and then dried at 180° C. to form a chemical conversion film. The chromium adhesion amount of this chemical film is 10 mg/m ² per single side.

Next, a biaxially stretched 6 nylon film 2 with a thickness of 25 μm was dry-laminated (bonded) on one side of the aluminum foil 4 after the aforementioned chemical conversion treatment was interposed between a 2-component curable polyurethane adhesive 5 .

Next, a first non-stretching film 7 with a thickness of 12 μm, which contains ethylene-propylene random copolymer, 1000 ppm of erucamide and 2000 ppm of silica particles (anti-blocking agent), is successively layered in two layers, containing ethylene- A second non-stretch film 8 with a thickness of 28 μm made of propylene block copolymer and 2500 ppm of erucamide was co-extruded using a T-die to obtain a sealing film with a thickness of 40 μm made of these two layers (the first non-stretch film). After stretching the film 7/the second non-stretching film 8) 3, the second non-stretching film 8 of the sealing film 3 is interposed with a 2-liquid curing type maleic acid modified polypropylene adhesive 6, and superimposed on the aforementioned dry layer The other side of the pressed aluminum foil 4 was dry-laminated by being sandwiched between a rubber nip roll and a laminating roll heated to 100° C., and then aged at 40° C. for 10 days (heating). An exterior material 1 for a power storage device having the configuration shown in FIG. 1 was obtained.

In addition, the maleic acid-modified polypropylene adhesive of the above-mentioned two-component curing type uses 100 parts by mass of maleic acid-modified polypropylene (melting point 80° C., acid value 10 mgKOH/g) as the main agent, and hexamethylene as the curing agent. 8 parts by mass of the isocyanurate body (NCO content: 20% by mass) of the base diisocyanate, which was further mixed with a solvent to form an adhesive solution; the solid coating amount of the adhesive solution was 2 g/m ² , It is coated on the other side of the aluminum foil 4, heated and dried, and then stacked on the second non-stretched film 8 of the sealing film 3.

In the obtained exterior material 1 for an electrical storage device, the amount of lubricant present on the surface 7a of the innermost layer (first non-stretched film 7) of the exterior material was 0.27 µg/cm ² (Table 1).

<Example 2>

A chemical conversion treatment liquid composed of phosphoric acid, polyacrylic acid (acrylic resin), chromium (III) salt compound, water, and ethanol was applied to both sides of the aluminum foil 4 with a thickness of 40 μm, and then dried at 180° C. to form a chemical conversion film. The chromium adhesion amount of this chemical film is 10 mg/m ² per single side.

Next, a biaxially stretched 6 nylon film 2 with a thickness of 25 μm was dry-laminated (bonded) on one side of the aluminum foil 4 after the aforementioned chemical conversion treatment was interposed between a 2-component curable polyurethane adhesive 5 .

Next, by sequentially layering 3 layers containing ethylene-propylene random copolymers, 1 000ppm of erucamide and 2000ppm of silicon dioxide particles (anti-blocking agent) 6μm 1st unstretched film 7, containing ethylene-propylene block copolymer and 2500ppm of erucamide 28μm second non-stretch film 8, 6μm thickness 6μm first non-stretch film 9 containing ethylene-propylene random copolymer, 1000ppm erucamide and 2000ppm silicon dioxide particles (anti-blocking agent) and using T The mold is co-extruded to obtain a sealing film with a thickness of 40 μm (the first non-stretching film 7 / the second non-stretching film 8 / the first non-stretching film 9) 3 formed by laminating these 3 layers, one side of the sealing film 3 The 9 side of the first non-stretching film is laminated on the other side of the aluminum foil 4 after dry lamination through a 2-liquid hardening type maleic acid-modified polypropylene adhesive 6, and is sandwiched by a rubber nip roller. and dry lamination by pressing between the lamination rolls heated to 100°C, and then aging at 40°C for 10 days (heating) to obtain an exterior material 1 for an electrical storage device having the configuration shown in FIG. 2 .

In addition, the maleic acid-modified polypropylene adhesive of the above-mentioned two-component curing type uses 100 parts by mass of maleic acid-modified polypropylene (melting point 80° C., acid value 10 mgKOH/g) as the main agent, and hexamethylene as the curing agent. 8 parts by mass of the isocyanurate body (NCO content: 20% by mass) of the base diisocyanate, which was further mixed with a solvent to form an adhesive solution; the solid coating amount of the adhesive solution was 2 g/m ² , It is coated on the other side of the aluminum foil 4, heated and dried, and then superimposed on the first non-stretched film 9 side of the one side of the sealing film 3.

In the obtained exterior material 1 for an electrical storage device, the amount of lubricant present on the surface 7a of the innermost layer (first non-stretched film 7) of the exterior material was 0.25 µg/cm ² (Table 1).

<Example 3>

Except that the content concentration of the erucamide in the second non-stretched film 8 before lamination was set to 1000 ppm, the same procedure as in Example 2 was carried out to obtain an exterior material 1 for a power storage device having the configuration shown in FIG. 2 . In the obtained exterior material 1 for an electrical storage device, the amount of lubricant present on the surface 7a of the innermost layer (first non-stretched film 7) of the exterior material was 0.20 µg/cm ² (Table 1).

<Example 4>

Except that the content concentration of the erucamide in the first unstretched films 7 and 9 before lamination was set to 500 ppm, the same procedure as in Example 2 was carried out to obtain an exterior material 1 for a power storage device having the configuration shown in FIG. 2 . In the obtained exterior material 1 for an electrical storage device, the amount of lubricant present on the surface 7a of the innermost layer (first non-stretched film 7) of the exterior material was 0.15 μg/cm ² (Table 1).

<Example 5>

Except that the concentration of erucamide in the second unstretched film 8 before lamination was set at 1000 ppm, and the content of erucamide in the first unstretched films 7 and 9 before lamination was set at 2000 ppm, the same as Example 2 In the same manner, the exterior material 1 for a power storage device having the configuration shown in FIG. 2 was obtained. In the obtained exterior material 1 for an electrical storage device, the amount of lubricant present on the surface 7a of the innermost layer (first non-stretched film 7) of the exterior material was 0.35 μg/cm ² (Table 1).

<Example 6>

Except that in the first unstretched films 7 and 9 and the second unstretched film 8, behenamide was used instead of erucamide as the lubricant, it was the same as in Example 2, and the structure shown in FIG. 2 was obtained. Exterior material 1 for electric storage device. In the obtained exterior material 1 for an electrical storage device, the amount of lubricant present on the surface 7a of the innermost layer (first non-stretched film 7) of the exterior material was 0.19 μg/cm ² (Table 1).

<Example 7>

Except that in the first non-stretched films 7 and 9 and the second non-stretched film 8, oleic acid amide was used instead of the lubricant erucamide, a power storage device having the configuration shown in FIG. 2 was obtained in the same manner as in Example 2. Use exterior material 1. In the obtained exterior material 1 for an electrical storage device, the amount of lubricant present on the surface 7a of the innermost layer (first non-stretched film 7) of the exterior material was 0.50 µg/cm ² (Table 1).

<Example 8>

Except that in the first non-stretched films 7 and 9 and the second non-stretched film 8, erucic acid amide was replaced with stearic acid amide instead of the lubricant, it was the same as in Example 2 to obtain a power storage with the structure shown in FIG. 2 . Device exterior material 1. In the obtained exterior material 1 for an electrical storage device, the amount of lubricant present on the surface 7a of the innermost layer (first non-stretched film 7) of the exterior material was 0.30 µg/cm ² (Table 1).

<Example 9>

Except that the content concentration of the erucamide in the second non-stretched film 8 before lamination was set to 4500 ppm, it was the same as in Example 2, to obtain an exterior material 1 for a power storage device having the configuration shown in FIG. 2 . In the obtained exterior material 1 for an electrical storage device, the amount of lubricant present on the surface 7a of the innermost layer (first non-stretched film 7) of the exterior material was 0.10 µg/cm ² (Table 1).

<Comparative Example 1>

Except that the content concentration of the erucamide in the second unstretched film 8 before lamination was set to 300 ppm, it carried out similarly to Example 1, and obtained the exterior material for electrical storage devices. In the obtained exterior material 1 for an electrical storage device, the amount of lubricant present on the surface 7a of the innermost layer (first non-stretched film 7) of the exterior material was 0.07 µg/cm ² (Table 1).

<Comparative Example 2>

Except that the content concentration of the erucamide in the second non-stretched film 8 before lamination was set to 300 ppm, it carried out similarly to Example 2, and obtained the exterior material for electrical storage devices. In the obtained exterior material 1 for an electrical storage device, the amount of lubricant present on the surface 7a of the innermost layer (first non-stretched film 7) of the exterior material was 0.08 μg/cm ² (Table 1).

<Comparative Example 3>

Except that the concentration of erucamide in the second unstretched film 8 before lamination was set at 8000 ppm, and the content of erucamide in the first unstretched films 7 and 9 before lamination was set at 2000 ppm, the same as Example 2 In the same manner, an exterior material for an electrical storage device was obtained. In the obtained exterior material 1 for an electrical storage device, the amount of lubricant present on the surface 7a of the innermost layer (first non-stretched film 7) of the exterior material was 1.31 μg/cm ² (Table 1).

<Comparative Example 4>

Except that the content concentration of erucamide in the second unstretched film 8 before lamination is set at 1500 ppm, and the content concentration of erucamide in the first unstretched films 7 and 9 before lamination is set at 8000 ppm, the same as Example 2 In the same manner, an exterior material for an electrical storage device was obtained. In the obtained exterior material 1 for an electrical storage device, the amount of lubricant present on the surface 7a of the innermost layer (first non-stretched film 7) of the exterior material was 1.05 μg/cm ² (Table 1).

<Comparative Example 5>

Example 2 is the same as Example 2, except that the concentration of erucamide in the second unstretched film 8 before lamination is set at 1500 ppm, and the concentration of erucamide in the first unstretched films 7 and 9 before lamination is set at 100 ppm In the same manner, an exterior material for an electrical storage device was obtained. In the obtained exterior material 1 for an electrical storage device, the amount of lubricant present on the surface 7a of the innermost layer (first non-stretched film 7) of the exterior material was 0.06 μg/cm ² (Table 1).

<Comparative Example 6>

It is the same as Example 1 except that the content concentration of erucamide in the second unstretched film 8 before lamination is set at 100 ppm, and the content concentration of erucamide in the first unstretched film 7 before lamination is set at 250 ppm. An exterior material for an electrical storage device was obtained. In the obtained exterior material 1 for an electrical storage device, the amount of lubricant present on the surface 7a of the innermost layer (first non-stretched film 7) of the exterior material was 0.02 μg/cm ² (Table 1).

<Comparative Example 7>

Example 2 is the same as Example 2, except that the concentration of erucamide in the second unstretched film 8 before lamination is set at 100 ppm, and the content of erucamide in the first unstretched films 7 and 9 before lamination is set at 250 ppm In the same manner, an exterior material for an electrical storage device was obtained. In the obtained exterior material 1 for an electrical storage device, the amount of lubricant present on the surface 7a of the innermost layer (first non-stretched film 7) of the exterior material was 0.02 μg/cm ² (Table 1).

<Comparative Example 8>

Except that the content concentration of erucamide in the second unstretched film 8 before lamination is set at 21000 ppm, and the content concentration of erucamide in the first unstretched films 7 and 9 before lamination is set at 3500 ppm, the same as Example 2 In the same manner, an exterior material for an electrical storage device was obtained. In the obtained exterior material 1 for an electrical storage device, the amount of lubricant present on the surface 7a of the innermost layer (first non-stretched film 7) of the exterior material was 3.20 µg/cm ² (Table 1).

<Comparative Example 9>

Except that the content concentration of erucamide in the second unstretched film 8 before lamination was set at 100 ppm, and the content concentration of erucamide in the first unstretched films 7 and 9 before lamination was set at 3500 ppm, the same as Example 2 In the same manner, an exterior material for an electrical storage device was obtained. In the obtained exterior material 1 for an electrical storage device, the amount of lubricant present on the surface 7a of the innermost layer (first non-stretched film 7) of the exterior material was 0.05 μg/cm ² (Table 1).

【Table 1】

Each of the exterior materials for electrical storage devices obtained as described above (the aging treatment was completed) was evaluated based on the following evaluation method. The results are shown in Table 1. In addition, the kinetic friction coefficient described in Table 1 complies with JIS K7125-1995, and the kinetic friction coefficient was measured on the surface 7a of the innermost layer of each exterior material for electrical storage devices (completed by aging treatment).

<Method for evaluating the amount of lubricant present on the surface of the innermost layer of the exterior material>

Two test pieces of a rectangle of 100 mm in length x 100 mm in width were cut out from each of the exterior materials for electrical storage devices, and these two test pieces were stacked and heat-sealed at a heat-sealing temperature of 200°C at the periphery of the sealing layers of both. Thereby, a bag body is produced. 1 mL of acetone was injected into the inner space of the bag body using a syringe, and the surface of the innermost layer 7 of the sealing layer was placed in contact with acetone for 3 minutes, and then the acetone in the bag body was withdrawn. The lubricant amount (μg/cm ² ) present on the surface of the innermost layer of the exterior material was obtained by measuring and analyzing the amount of lubricant contained in the extracted liquid using a gas chromatograph. That is, the amount of lubricant per 1 cm ² of the surface of the innermost layer was obtained.

<Formability Evaluation Method>

Using a free straight mold with deep forming depth, the outer material was deep drawn and formed in one stage under the following forming conditions, and the formability was evaluated at each forming depth (9mm, 8mm, 7mm, 6mm, 5mm, 4mm, 3mm, 2mm), and the investigation was carried out in The maximum forming depth (mm) that can be well formed without any pinholes at the corners. Those with a maximum forming depth of 5 mm or more are marked with "○", those with a maximum forming depth of 2 mm or more and less than 5 mm are marked with "△", and those with a maximum forming depth of less than 2 mm are marked with "×". The results are shown in Table 1. In addition, the presence or absence of pinholes was investigated by visually observing the presence or absence of transmitted light passing through the pinholes.

(forming conditions)

Forming die...Punch: 33.3mm×53.9mm, Die: 80mm×120 mm, corner R: 2mm, punch R: 1.3mm, die R: 1mm

Anti-crease pressure... gauge pressure: 0.475MPa, actual pressure (calculated value): 0.7MPa

Material...SC (carbon steel) material, only punch R is chrome plated.

<Evaluation method for the presence or absence of white powder>

After cutting out a rectangular test piece with a length of 600 mm and a width of 100 mm from each exterior material for a power storage device, the obtained test piece was placed on the test stand with the inner sealing layer 3 surfaces (that is, the surface 7a of the innermost layer) on the upper side. On the top of the test piece, place a black SUS hammer (mass 1.3kg, size of the ground plane is 55mm × 50mm) wrapped with black cloth, and the hammer is placed on the test piece. The parallel horizontal direction was stretched at a tensile speed of 4 cm/sec, and the test piece was vertically moved over a length of 400 mm in a contact state. Observe the cloth (black) on the contact surface of the hammer after stretching and moving with the naked eye. If the white powder is on the surface of the cloth (black), it is marked with "X", and the white powder is marked with a normal degree (medium level), and it is marked with "△". Those with little or no white powder were marked with "○". In addition, as the above-mentioned black cloth, "Static Removal Sheet S SD2525 3100" manufactured by TRUSCO Co., Ltd. was used.

<Comprehensive Judgment>

If the evaluation of the formability is "○" and the evaluation of the presence or absence of white powder is also "○", it is marked with "○" in the comprehensive judgment; if at least one of the evaluation of the formability and the evaluation of the presence or absence of white powder is "x", it is in the comprehensive judgment Mark "X".

As is apparent from Table 1, the exterior materials for electrical storage devices of Examples 1 to 9 of the present invention formed by using the sealing film of the present invention are excellent in formability, and white powder hardly appears on the surface of the exterior materials.

On the other hand, in Comparative Examples 1, 2, 5 to 7, and 9, which deviate from the scope of the present invention, the formability of the exterior material is not good, and Comparative Examples 3, 4, and 8, which deviate from the scope of the present invention, are The surface of the loading material was noticeably chalked up.

【Industrial Availability】

Specific examples of the exterior material for electrical storage devices produced using the sealing film of the present invention and the exterior material for electrical storage devices of the present invention are, for example, used for

. Power storage devices such as lithium-ion batteries (lithium-ion batteries, lithium-polymer batteries, etc.)

. Lithium Ion Capacitors

. External materials for various electric storage devices such as electric double layer capacitors. In addition, the power storage device of the present invention, in addition to the power storage device of the above example, also includes an all-solid-state battery.

This application claims priority along with Japanese Patent Application No. 2016-115176 of Japanese Patent Application filed on June 9, 2016, and the disclosure thereof directly constitutes a part of this application.

The terms and descriptions used here are used to describe the embodiments of the present invention, but the present invention is not limited thereto. Any equivalents to the characteristic matters disclosed and recited in the present invention should not be excluded, and various modifications within the claimed scope of the present invention should also be understood to be acceptable.

1: Exterior materials for power storage devices

2: Heat-resistant resin layer (outer layer)

3: Inner sealing layer (sealing film) (inner layer)

4: Metal foil layer

5: Second adhesive layer (outer adhesive layer)

6: 1st adhesive layer (inner adhesive layer)

7: 1st non-stretch film layer (innermost layer)

7a: The surface of the first unstretched film layer (the surface of the innermost layer of the exterior material)

8: The second non-stretching film layer

9: 1st unstretched film layer (metal foil layer side)

Claims (12)

An exterior material for a power storage device, comprising: an inner sealing layer, and a metal foil layer laminated on one side of the inner sealing layer; characterized in that the inner sealing layer is composed of a first non-stretching film layer, and The area layer on one side of the first unstretched film layer is composed of a laminate of two or more layers of the second unstretched film layer; the first unstretched film layer forms the innermost layer of the exterior material; the aforementioned The first unstretched film layer includes a random copolymer containing propylene as a copolymerization component and other copolymerization components other than propylene, and a lubricant; the second unstretched film layer includes propylene as a copolymerization component and a lubricant. Block copolymers of other copolymerization components other than propylene, and lubricants; the concentration of the lubricant in the first non-stretched film layer is 200 ppm to 3000 ppm, and the concentration of the lubricant in the second non-stretched film layer is 200 ppm to 3000 ppm 500ppm~5000ppm; the lubricant content of the second non-stretching film layer is 0.5 times to 5 times the lubricant content of the first non-stretching film layer that forms the innermost layer of the exterior material; The coefficient of kinetic friction of the surface of the first non-stretched film layer of the innermost layer of the packing material is in the range of 0.15 to 0.50. An exterior material for a power storage device, comprising: an inner sealing layer, and a metal foil layer laminated on one side of the inner sealing layer; characterized in that the inner sealing layer is composed of a second non-stretching film layer, a The first unstretched film layer of the area layer on one side of the second unstretched film layer, and the second unstretched film layer on the other side of the second unstretched film layer The first non-stretch film layer of the area layer is composed of a laminate of three or more layers; the first non-stretch film layer on either side forms the innermost layer of the exterior material; the first non-stretch film layer, A random copolymer containing propylene as a copolymer component and other copolymer components other than propylene, and a lubricant; the aforementioned second non-stretch film layer contains propylene as a copolymer component and another copolymer other than propylene The block copolymer of the components, and the lubricant; the concentration of the lubricant in the first non-stretched film layer is 200 ppm to 3000 ppm, and the concentration of the lubricant in the second non-stretched thin film layer is 500 ppm to 5000 ppm; The concentration of the lubricant in the non-stretched film layer is 0.5 to 5 times the concentration of the lubricant in the first non-stretched film layer that forms the innermost layer of the exterior material; The coefficient of kinetic friction of the surface of the first non-stretched film layer is in the range of 0.15 to 0.50. The exterior material for an electrical storage device according to claim 1 or 2, wherein the lubricant content of the second unstretched film layer is at a concentration of the first unstretched film that forms the innermost layer of the exterior material The lubricant of the layer contains 1.0 to 3.0 times the concentration. The exterior material for a power storage device according to claim 1 or 2, wherein the lubricant is at least one lubricant selected from the group consisting of saturated fatty acid amides and unsaturated fatty acid amides. The exterior material for an electrical storage device according to claim 1 or 2, wherein the concentration of the lubricant in the first non-stretched film layer forming the innermost layer is 800 ppm to 1200 ppm, and the second non-stretched film The concentration of lubricant in the layer is 800ppm ~2700ppm. The exterior material for an electrical storage device according to claim 1 or 2, wherein a heat-resistant resin layer as an outer layer is laminated on the surface opposite to the surface of the metal foil layer on which the inner sealing layer is laminated . The exterior material for an electrical storage device according to claim 1 or 2, wherein the amount of lubricant present on the surface of the first non-stretched thin film layer forming the innermost layer of the exterior material is 0.1 μg/cm ² ~ 1.0μg/cm ² range. A method for manufacturing an exterior material for a power storage device, characterized by comprising: a preparation step of preparing a sealing film to be an inner sealing layer and a metal foil layered body to be a metal foil layer via a first adhesive layer; an aging step, The said laminated body is heat-processed, and the exterior material for electric storage devices as described in any one of Claims 1-7 is obtained. The manufacturing method of the exterior material for electric storage devices as described in Claim 8 in which the said 1st adhesive agent is a thermosetting adhesive agent. A method of manufacturing an exterior material for an electrical storage device, comprising: a preparation step of laminating a heat-resistant resin film on one side of a metal foil to be a metal foil layer via a second adhesive and on the metal foil The other side is a laminated body composed of a sealing film that is laminated with a first adhesive layer to become an inner sealing layer; the aging step is to heat-treat the above-mentioned laminated body to obtain the power storage device as described in claim 6 or 7 of the scope of the application. Exterior material. The method for producing an exterior material for an electrical storage device according to claim 10, wherein the first adhesive is a thermosetting adhesive, and the second adhesive is a thermosetting adhesive agent. The method for producing an exterior material for an electrical storage device as described in any one of Claims 8 to 11 of the scope of the application, wherein the method of forming the first innermost layer of the exterior material for an electrical storage device obtained by heat treatment The amount of lubricant on the surface of the non-stretched film layer is in the range of 0.1 μg/cm ² to 1.0 μg/cm ² .

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