Outer packaging material for energy storage device, outer packaging case for energy storage device, and energy storage device

Abstract

The present invention relates to an outer packaging material for a power storage device, an outer packaging case for a power storage device, and a power storage device. The outer packaging material for a power storage device has the following structure: it includes a heat-resistant resin layer (2) as an outer layer, a sealing layer (3) as an inner layer, and a metal foil layer (4) disposed between these two layers. The sealing layer (3) includes one layer to multiple layers, and the innermost layer (7) of the sealing layer contains a random copolymer, a surface roughening material, and a lubricant. The random copolymer contains propylene and other copolymerization components other than propylene as copolymerization components. The surface roughening material is formed of particles containing a thermoplastic resin. The center line average roughness Ra of the surface (7a) of the innermost layer (7) is 0.05 μm to 1 μm. The present invention can provide an outer packaging material for a power storage device that has excellent moldability and is not likely to show white powder on the surface.

Description

[0001] This application is a divisional application of Chinese Patent Application No. 201711010630.7, with the application date of October 25, 2017 and the invention title of "Outer packaging material for electricity storage device, outer packaging case for electricity storage device and electricity storage device". Technical Field

[0002] The present invention relates to an outer packaging material for the following electricity storage devices and an electricity storage device obtained by performing outer packaging using the outer packaging material. The electricity storage devices include: batteries and capacitors (condensers) for portable devices such as smart phones and tablet computers; batteries and capacitors for electricity storage applications of hybrid vehicles, electric vehicles, wind power generation, solar power generation, and night power; and so on.

[0003] It should be noted that in the claims and the specification of the present application, the term "center line average roughness (Ra)" refers to the center line average roughness (Ra) measured in accordance with JIS B0601-2001.

[0004] In addition, in the claims and the specification of the present application, the term "density" refers to the density measured in accordance with JIS K 7112-1999 Method D (density gradient tube method).

[0005] In addition, in the claims and the specification of the present application, the term "melt flow rate (MFR)" refers to the melt flow rate measured in accordance with JIS K7210-1-2014.

[0006] In addition, in the specification of the present application, the term "swell (percentage)" refers to the room temperature die swell percentage (%) obtained in accordance with Capillary Rheometer Method A specified in JIS K 7199-1999. Background Art

[0007] In recent years, with the thinning and lightening of mobile electronic devices such as smartphones and tablet terminals, as the outer packaging material for power storage devices such as lithium-ion secondary batteries, lithium polymer secondary batteries, lithium-ion capacitors, and electric double-layer condensers mounted on the above-mentioned mobile electronic devices, a laminate formed of a heat-resistant resin layer / adhesive layer / metal foil layer / adhesive layer / thermoplastic resin layer (inner sealing layer) has been used instead of the conventional metal casing. In addition, the use of the laminate (outer packaging material) with the above structure to package the power sources of electric vehicles, etc., large power sources for power storage applications, capacitors, etc. is also gradually increasing. By performing convex forming and deep drawing forming on the above laminate, it is formed into a three-dimensional shape such as a substantially rectangular parallelepiped shape. By forming into the above three-dimensional shape, a storage space for storing the main body of the power storage device can be ensured.

[0008] In order to be formed into the above three-dimensional shape in a good state without generating pinholes, fractures, etc., it is required to improve the slidability of the surface of the inner sealing layer. As a material for improving the slidability of the surface of the inner sealing layer to ensure good formability, the following laminate for a secondary battery container has been proposed. The laminate is obtained by laminating an outer packaging resin film, a first adhesive layer, a chemically converted aluminum foil, a second adhesive layer, and a sealing film in this order. The above sealing film is formed of a random copolymer of propylene and an α-olefin (the content of the α-olefin is 2 to 10% by weight), and contains 1000 to 5000 ppm of a lubricant (see Patent Document 1).

[0009] Patent Document 1: Japanese Patent Laid-Open No. 2003-288865 Summary of the Invention

[0010] However, in the above prior art, due to the heating retention time and storage period in the production process of the outer packaging material (laminate), it is difficult to control the amount of lubricant precipitated on the surface. Although the slidability during molding is good, the lubricant precipitates excessively on the surface. Therefore, during the molding of the outer packaging material, the lubricant adheres and accumulates on the molding surface of the molding die to generate white powder (white powder formed by the lubricant). If the above 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. However, due to the cleaning and removal of the above white powder, there is a problem that the productivity of the outer packaging material is reduced.

[0011] Of course, if the addition amount of the lubricant (lubricant content rate) is reduced, the adhesion and accumulation of white powder can be suppressed. However, in this case, there is a problem that the amount of the lubricant precipitated on the surface is insufficient, resulting in poor moldability. As described above, it has been difficult to simultaneously achieve excellent moldability and suppression of the appearance of white powder on the surface of the exterior member.

[0012] The present invention has been made in view of the above technical background, and an object thereof is to provide an outer packaging material for a power storage device, an outer packaging case for a power storage device, and a power storage device that can ensure good slidability during molding, thereby having excellent moldability and being less likely to show white powder on the surface.

[0013] Means for Solving the Problem

[0014] To achieve the above object, the present invention provides the following solutions.

[0015] [1] An outer packaging material for a power storage device, characterized in that the outer packaging material for a power storage device includes a heat-resistant resin layer as an outer layer, a sealing layer as an inner layer, and a metal foil layer disposed between these two layers.

[0016] The above sealing layer includes one layer to a plurality of layers, and the innermost layer of the sealing layer contains a random copolymer, a surface roughening material ("surface roughening material" in Japanese), and a lubricant. The random copolymer contains propylene and other copolymerization components other than propylene as copolymerization components.

[0017] The above surface roughening material is formed of particles containing a thermoplastic resin.

[0018] The center line average roughness Ra of the surface of the above innermost layer is 0.05 μm to 1 μm.

[0019] [2] The outer packaging material for a power storage device according to the previous item 1, wherein the thermoplastic resin constituting the above surface roughening material is a high-density polyethylene resin.

[0020] [3] The outer packaging material for a power storage device according to the previous item 2, wherein the density of the above high-density polyethylene resin is 0.935 g / cm 3 ~0.965 g / cm 3 , and the melt flow rate of the above high-density polyethylene resin at 190 ° C is in the range of 0.01 g / 10 minutes to 2 g / 10 minutes.

[0021] [4] The outer packaging material for a power storage device according to any one of the previous items 1 to 3, wherein the content rate of the above surface roughening material in the innermost layer of the above sealing layer is 1% by mass to 30% by mass, and the content rate of the above lubricant in the innermost layer is greater than 0 ppm and 1000 ppm or less.

[0022] [5] The outer packaging material for an electricity storage device according to any one of the preceding items 1 to 4, wherein the lubricant is one or more lubricants selected from the group consisting of fatty acid amides, waxes, silicones, and paraffin.

[0023] [6] The outer packaging material for an electricity storage device according to any one of the preceding items 1 to 5, wherein the sealing layer comprises a plurality of layers.

[0024] [7] The outer packaging material for an electricity storage device according to item 6 above, wherein the sealing layer comprises the innermost layer and a first intermediate layer laminated on the surface of the innermost layer on the side of the metal foil layer,

[0025] The first intermediate layer contains an elastomer-modified olefin resin,

[0026] The elastomer-modified olefin resin comprises an elastomer-modified homopolypropylene or / and an elastomer-modified random copolymer,

[0027] The elastomer-modified random copolymer is an elastomer-modified body of a random copolymer containing propylene and other copolymerization components other than propylene as copolymerization components.

[0028] [8] The outer packaging material for an electricity storage device according to item 6 above, wherein the sealing layer comprises the innermost layer, a first intermediate layer laminated on the surface of the innermost layer on the side of the metal foil layer, and a second intermediate layer laminated on the surface of the first intermediate layer on the side of the metal foil layer,

[0029] The first intermediate layer contains an elastomer-modified olefin resin,

[0030] The elastomer-modified olefin resin comprises an elastomer-modified homopolypropylene or / and an elastomer-modified random copolymer,

[0031] The elastomer-modified random copolymer is an elastomer-modified body of a random copolymer containing propylene and other copolymerization components other than propylene as copolymerization components,

[0032] The second intermediate layer contains a random copolymer containing propylene and other copolymerization components other than propylene as copolymerization components.

[0033] [9] The outer packaging case for an electricity storage device, which is formed of a molded body of the outer packaging material for an electricity storage device according to any one of the preceding items 1 to 8.

[0034]

[10] An electricity storage device, characterized in that the electricity storage device has:

[0035] An electricity storage device main body; and

[0036] An outer packaging member, which is formed of the outer packaging material for a power storage device according to any one of the preceding items 1 to 8 and / or the outer packaging case for a power storage device according to the preceding item 9.

[0037] The main body portion of the power storage device is externally packaged by the above-mentioned outer packaging member.

[0038] Advantages of the Invention

[0039] For the invention of [1], the innermost layer of the sealing layer contains a random copolymer (which contains propylene and other copolymer components other than propylene as copolymer components), a surface roughening material, and a lubricant. The surface roughening material is formed of particles containing a thermoplastic resin. The center line average roughness Ra of the surface of the innermost layer is 0.05 μm to 1 μm. Therefore, good slidability can be ensured during molding, and the moldability is excellent. In addition, by using the surface roughening material together with the lubricant (by using the surface roughening material, the amount of lubricant used can be reduced compared with the prior art), the center line average roughness Ra of the surface of the innermost layer is set to 0.05 μm to 1 μm. Therefore, it is not easy to expose white powder on the surface 7a of the innermost layer of the sealing layer of the outer packaging material. Since it is not easy to expose white powder as described above, the productivity of the outer packaging material can be improved, and sufficient sealing performance can be ensured in the heat-sealed portion after heat-sealing the sealing layers with each other. In addition, as described above, by using the surface roughening material, the amount of lubricant used can be reduced compared with the prior art. Thus, for example, it is not necessary to adjust the exudation amount of the lubricant during the aging process, the aging process is not required, or the aging process can be completed in a short time. Therefore, the productivity of the outer packaging material can be further improved. In addition, since the surface roughening material is formed of particles containing a thermoplastic resin, the clogging of the filter during the processing of the resin for the innermost layer can be reduced, and the productivity can be further improved. In addition, since the surface roughening material is formed of particles containing a thermoplastic resin, it will not be embedded inside or fall off when externally pressurized like silica particles.

[0040] For the invention of [2], since the thermoplastic resin constituting the surface roughening material is a high-density polyethylene resin, the compatibility of the high-density polyethylene resin with the above-mentioned random copolymer is moderately low. Thus, effective surface roughening can be carried out, and the slidability can be further improved.

[0041] For the invention of [3], the slidability during molding can be further improved, and thus the moldability can be further improved.

[0042] For the invention of [4], by setting the content rate of the surface roughening material in the innermost layer to 1% by mass to 30% by mass, excellent moldability can be ensured even when the content rate of the lubricant in the innermost layer is 1000 ppm or less. In addition, since the content rate of the lubricant in the innermost layer is more than 0 ppm and 1000 ppm or less, it is less likely to show white powder on the surface of the innermost layer of the sealing layer of the outer packaging material. Furthermore, since the content rate of the lubricant in the innermost layer is more than 0 ppm and 1000 ppm or less, the amount of the lubricant present on the surface of the innermost layer of the outer packaging material can also be stabilized during storage (for example, the change in the amount of the lubricant present on the surface of the innermost layer due to long-term storage can be suppressed), and thus excellent moldability can be stably ensured.

[0043] For the invention of [5], as the above-mentioned lubricant, one or more lubricants selected from the group consisting of fatty acid amides, waxes, silicones, and paraffins are used, so that better slidability can be ensured during molding, and thus more excellent moldability can be ensured.

[0044] For the invention of [6], the sealing layer has a structure including multiple layers and is formed as a structure in which one to multiple layers are laminated on the surface of the innermost layer on the side of the metal foil layer. Thus, for example, the adhesive force between the sealing layer and the metal foil layer can be further improved.

[0045] For the invention of [7], the sealing layer has a structure including the innermost layer and the first intermediate layer with the above-mentioned specific constitution laminated on the surface of the innermost layer on the side of the metal foil layer. Therefore, whitening of the sealing layer during molding can be sufficiently suppressed, and the sealing property during heat sealing can be sufficiently ensured.

[0046] For the invention of [8], the sealing layer has a structure including the innermost layer, the first intermediate layer with the above-mentioned specific constitution laminated on the surface of the innermost layer on the side of the metal foil layer, and the second intermediate layer with the above-mentioned specific constitution laminated on the surface of the first intermediate layer on the side of the metal foil layer. Therefore, not only can the above effects brought by the invention of [7] be obtained, but also the adhesive force between the sealing layer and the metal foil layer can be further improved, and sufficient insulation can be ensured.

[0047] For the invention of [9], an outer packaging case for a power storage device that can be molded well and is less likely to show white powder on the surface of the outer packaging case (the surface of the innermost layer of the sealing layer) can be provided.

[0048] For the invention of

[10] , a power storage device packaged with an outer packaging material and / or an outer packaging case for a power storage device that can be molded well and is less likely to show white powder on the surface (the surface of the innermost layer of the sealing layer) can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 FIG. 4 is a sectional view showing a first embodiment of an outer packaging material for a power storage device according to the present invention.

[0050] Figure 2 FIG. 8 is a sectional view showing a second embodiment of an outer packaging material for a power storage device according to the present invention.

[0051] Figure 3 FIG. 12 is a sectional view showing a third embodiment of an outer packaging material for a power storage device according to the present invention.

[0052] Figure 4 FIG. 16 is a sectional view showing an embodiment of a power storage device according to the present invention.

[0053] Figure 5 FIG. 20 is a perspective view showing a power storage device, an outer packaging material (flat shape), and an outer packaging case (a molded body molded into a three-dimensional shape) that are separated before heat sealing. Figure 4

[0054] DESCRIPTION OF REFERENCE NUMERALS

[0055] 1... Outer packaging material for power storage device

[0056] 2... Heat-resistant resin layer (outer layer)

[0057] 3... Sealing layer (inner layer)

[0058] 4... Metal foil layer

[0059] 5... Second adhesive layer (outer adhesive layer)

[0060] 6... First adhesive layer (inner adhesive layer)

[0061] 7... Innermost layer

[0062] 7a... Surface of the innermost layer of the sealing layer

[0063] 8... First intermediate layer

[0064] 9... Second intermediate layer

[0065] 10... Outer packaging case for power storage device (molded body)

[0066] 15... Outer packaging member

[0067] 30... Power storage device

[0068] 31... Power storage device main body part DETAILED DESCRIPTION OF THE INVENTION

[0069] ​The outer packaging material 1 for a power storage device according to the present invention includes a heat-resistant resin layer 2 as an outer layer, a sealing layer 3 as an inner layer, and a metal foil layer 4 disposed between these two layers. The sealing layer 3 includes one layer to a plurality of layers, and the innermost layer 7 of the sealing layer 3 contains a random copolymer, a surface roughening material, and a lubricant. The random copolymer contains propylene and other copolymerization components other than propylene as copolymerization components. The surface roughening material is formed of particles containing a thermoplastic resin. The center line average roughness Ra of the surface 7a of the innermost layer 7 is 0.05 μm to 1 μm.

[0070] Regarding the outer packaging material 1 for a power storage device according to the present invention, three embodiments are respectively shown in Figures 1 - 3 . The above three embodiments are merely representative embodiments and are not particularly limited to such a structure.

[0071] Figures 1 - 3 The outer packaging materials 1 for power storage devices shown are all of the following structure: A heat-resistant resin layer (outer layer) 2 is laminated and integrated via a second adhesive layer (outer adhesive layer) 5 on one surface (upper surface) of the metal foil layer 4, and a sealing layer (inner layer) 3 is laminated and integrated via a first adhesive layer (inner adhesive layer) 6 on the other surface (lower surface) of the metal foil layer 4.

[0072] Moreover, in Figure 1 the outer packaging material 1 for a power storage device shown, the sealing layer (inner layer) 3 includes the innermost layer 7 and a first intermediate layer 8 laminated on the surface of the innermost layer 7 on the side of the metal foil layer 4. That is, the first intermediate layer 8 is laminated via the first adhesive layer (inner adhesive layer) 6 on the other surface (lower surface) of the metal foil layer 4, and the innermost layer 7 is laminated on the surface (lower surface) of the first intermediate layer 8. The innermost layer 7 is exposed on the inner surface of the outer packaging material 1 (see Figure 1 ).

[0073] In addition, in Figure 2 the outer packaging material 1 for a power storage device shown, the sealing layer (inner layer) 3 includes the innermost layer 7, a first intermediate layer 8 laminated on the surface of the innermost layer 7 on the side of the metal foil layer 4, and a second intermediate layer 9 laminated on the surface of the first intermediate layer 8 on the side of the metal foil layer 4. That is, the second intermediate layer 9 is laminated via the first adhesive layer (inner adhesive layer) 6 on the other surface (lower surface) of the metal foil layer 4, the first intermediate layer 8 is laminated on the surface (lower surface) of the second intermediate layer 9, and the innermost layer 7 is laminated on the surface (lower surface) of the first intermediate layer 8. The innermost layer 7 is exposed on the inner surface of the outer packaging material 1 (see Figure 2 ).

[0074] In addition, in the outer packaging material 1 for an electrical storage device shown in Figure 3 , the above-mentioned sealing layer (inner layer) 3 includes the above-mentioned innermost layer 7. That is, on the other surface (lower surface) of the above-mentioned metal foil layer 4, the sealing layer 3 formed by the above-mentioned innermost layer 7 is laminated with a first adhesive layer (inner adhesive layer) 6 interposed therebetween. The above-mentioned innermost layer 7 is exposed on the surface on the inner side of the outer packaging material 1 (see Figure 3 ).

[0075] In the present invention, the above-mentioned sealing layer (inner layer) 3 functions as follows: making the outer packaging material excellent in chemical resistance even against highly corrosive electrolytes used in lithium-ion secondary batteries and the like, and imparting heat sealability to the outer packaging material.

[0076] In the present invention, the innermost layer 7 of the above-mentioned sealing layer 3 has a structure containing a random copolymer, a surface roughening material, and a lubricant, and the random copolymer contains propylene and other copolymer components other than propylene as copolymer components.

[0077] The above-mentioned random copolymer is a random copolymer containing "propylene" and "other copolymer components other than propylene" as copolymer components. Regarding the above-mentioned random copolymer, there is no particular limitation on the above-mentioned "other copolymer components other than propylene", and for example, olefin components such as ethylene, 1-butene, 1-hexene, 1-pentene, 4-methyl-1-pentene, and butadiene can be cited.

[0078] The melt flow rate (MFR) of the above-mentioned random copolymer (random copolymer containing propylene and other copolymer components other than propylene as copolymer components) at 230 °C is preferably in the range of 1 g / 10 minutes to 10 g / 10 minutes. By using the above-mentioned random copolymer with an MFR in the range of 1 g / 10 minutes to 10 g / 10 minutes, the surface roughening material can be dispersed finely and uniformly, and the sealing performance when sealing the electrical storage device main body in the outer packaging material can be improved, sufficient heat seal strength can be obtained, and moreover, a decrease in the thickness of the sealing layer after heat sealing can be suppressed, thereby further improving the insulation performance. When using an ethylene-propylene random copolymer as the above-mentioned random copolymer, the ethylene content in the random copolymer is preferably 3% by mass to 7% by mass. In this case, even when heat sealing is performed at a relatively low heat seal temperature of about 200 °C, high heat seal strength can be obtained. In addition, the melting point of the above-mentioned random copolymer is preferably in the range of 140 °C to 155 °C.

[0079] As the above-mentioned surface roughening material, there is no particular limitation. For example, particles containing a thermoplastic resin, powders containing a thermoplastic resin, etc. can be used. Among them, from the aspect of dispersibility, powders containing a thermoplastic resin are preferred. As the thermoplastic resin constituting the above-mentioned surface roughening material, there is no particular limitation. For example, high-density polyethylene resin, low-density polyethylene resin, ethylene-olefin (olefins other than ethylene) copolymer resin, ethylene-vinyl ester copolymer resin, styrene-based resin, etc. can be cited. Among them, as the above-mentioned surface roughening material, a surface roughening material formed by containing high-density polyethylene resin is preferably used. In this case, the surface 7a of the innermost layer 7 of the sealing layer can be effectively surface-roughened without impairing the heat sealability, thereby further improving the slidability.

[0080] In a state where the above-mentioned surface roughening material particles having low compatibility with the matrix of the above-mentioned random copolymer constituting the above-mentioned innermost layer 7 are dispersed in the matrix, by forming a state where the above-mentioned surface roughening material particles are partially exposed (protruded) on the surface 7a of the above-mentioned innermost layer 7, irregularities (the surface is roughened) are formed on the surface 7a. For example, thermoplastic resin particles or thermoplastic resin powders as the surface roughening material are mixed into the particles or powders of the above-mentioned random copolymer, and the mixture is melt-kneaded with an extruder or the like to finely disperse it, and then cooled and solidified, whereby an innermost layer having irregularities formed on the surface 7a of the above-mentioned innermost layer 7 (the innermost layer whose surface is roughened) is obtained.

[0081] The average particle diameter of the above-mentioned surface roughening material in the dispersed state is preferably in the range of 0.05 μm to 10 μm. In this case, the slidability can be further improved.

[0082] The density of the high-density polyethylene resin (HDPE) constituting the above-mentioned surface roughening material is preferably 0.935 g / cm 3 ~0.965 g / cm 3 Within such a density range, the slidability can be further improved, and thus the moldability can be further improved. Among them, the density of the high-density polyethylene resin (HDPE) constituting the above-mentioned surface roughening material is more preferably 0.945 g / cm 3 ~0.960 g / cm 3 Within the range.

[0083] The density of the above-mentioned high-density polyethylene resin can be adjusted by changing the content rate of the comonomer (copolymerization component). As the above-mentioned comonomer, unsaturated olefins other than ethylene such as 1-butene, 1-hexene, 1-octene, and 4-methyl-1-pentene can be cited, but it is not particularly limited to these. As the above-mentioned comonomer, at least one comonomer selected from the group consisting of 1-butene and 1-hexene is preferably used.

[0084] The melt flow rate (MFR) of the high-density polyethylene resin constituting the above-mentioned surface roughening material at 190 °C is preferably in the range of 0.01 g / 10 minutes to 2 g / 10 minutes. By making the MFR 0.01 g / 10 minutes or more, the surface roughening material can be finely and uniformly dispersed in the above-mentioned random copolymer, and by making the MFR 2 g / 10 minutes or less, the surface roughness can be increased, thereby further improving the slidability. Among them, the melt flow rate (MFR) of the high-density polyethylene resin (HDPE) constituting the above-mentioned surface roughening material at 190 °C is particularly preferably in the range of 0.1 g / 10 minutes to 1 g / 10 minutes.

[0085] The melt flow rate (MFR) of the above-mentioned high-density polyethylene resin can be adjusted, for example, in the following manner. For the case of manufacturing the above-mentioned high-density polyethylene resin using a Phillips catalyst, the MFR of the high-density polyethylene resin can be adjusted by changing the reactor temperature during polymerization, or the MFR of the high-density polyethylene resin can be adjusted by changing the reactor temperature on the basis of adding a small amount of hydrogen. In addition, for the case of manufacturing the above-mentioned high-density polyethylene resin using a Ziegler catalyst, the MFR of the high-density polyethylene resin can be adjusted by changing the amount of hydrogen supplied to the reactor during polymerization. In the case of using the above-mentioned Phillips catalyst, isobutane can be used as a solvent and the above-mentioned high-density polyethylene resin can be manufactured by slurry polymerization, but it is not particularly limited to such a method.

[0086] The melting point of the high-density polyethylene resin constituting the above-mentioned surface roughening material is preferably in the range of 130 °C to 145 °C. In addition, the high-density polyethylene resin preferably has long branches (carbon atom number of 10 or more). In the case of using a high-density polyethylene resin having long branches, when the surface roughening material and the above-mentioned random copolymer are melt-kneaded, it is easy to form surface roughening material particles. Therefore, the outermost surface 7a can be more effectively surface-roughened, thereby further improving the slidability.

[0087] The swell of the high-density polyethylene resin constituting the above-mentioned surface roughening material is preferably in the range of 25% to 55%. In this case, the melt viscoelasticity of the resin constituting the surface roughening material is high. Therefore, it is easy to form particles of the high-density polyethylene resin, and the outermost surface 7a can be more effectively surface-roughened, thereby further improving the slidability. Among them, the swell of the high-density polyethylene resin constituting the above-mentioned surface roughening material is more preferably in the range of 35% to 45%.

[0088] It should be noted that the above "swelling" refers to the percentage of die swell at room temperature (%) obtained by Method A of the capillary rheometer specified in JIS K7199-1999. Using the standard die (aperture: 2.095 mm, length: 8 mm) specified in JIS K7210-1-2014, when the strand (linear resin) of the resin extruded from the capillary die becomes 2 cm in length under the conditions of a temperature of 190 °C and a load of 2.16 kg, the strand is collected with tweezers. After natural cooling and curing, the diameter of the strand at a portion 1 cm from the front end is measured with a micrometer, and this measured value is taken as D1 (mm). At this time, the above "swelling" is the value (%) obtained by the following formula,

[0089] Swelling (%) = { (D1 - D0) / D0} × 100

[0090] D1: Diameter of the extruded resin

[0091] D0: Standard die aperture (2.095 mm).

[0092] The high-load swelling (swelling at a load of 21.6 kg) of the high-density polyethylene resin constituting the above surface roughening material is preferably in the range of 55% to 90%. In this case, since the melt viscoelasticity of the resin constituting the surface roughening material is relatively high, it is easy to form particles of the high-density polyethylene resin, and the outermost surface 7a can be surface-roughened more effectively, thereby further improving the slidability.

[0093] It should be noted that for the above high-load swelling, in accordance with JIS K7199-1999, using the standard die (aperture: 2.095 mm, length: 8 mm) specified in JIS K7210-1-2014, when the strand (linear resin) of the resin extruded from the capillary die becomes 2 cm in length under the conditions of a temperature of 190 °C and a load of 21.6 kg, the strand is collected with tweezers. After natural cooling and curing, the diameter of the strand at a portion 1 cm from the front end is measured with a micrometer, and this measured value is taken as D2 (mm). At this time, the above high-load swelling is the value obtained by the following formula,

[0094] High-load swelling (%) = { (D2 - D0) / D0} × 100

[0095] D2: Diameter of the extruded resin

[0096] D0: Standard die aperture (2.095 mm).

[0097] The "high load MFR (MFR under a load of 21.6 kg) / MFR (MFR under a load of 2.16 kg)" of the high-density polyethylene resin constituting the above surface roughening material is preferably in the range of 25 to 40. In this case, the compatibility between the above-mentioned random copolymer and the surface roughening material can be ensured to a certain extent, thereby further suppressing the whitening of the sealing layer 3 during molding.

[0098] The difference between the melt density and the density of the above surface roughening material is preferably 0.15 g / cm 3 ~0.25 g / cm 3 In the range. In this case, during the process of cooling and solidifying the mixed resin from the molten state, the volume shrinkage rate of the surface roughening material becomes larger. Therefore, the surface 7a of the innermost layer 7 can be effectively roughened, and thus the center line average roughness Ra of the surface 7a of the innermost layer 7 can be easily adjusted to 0.05 μm to 1 μm.

[0099] In the innermost layer 7 of the above sealing layer, the difference between the density of the above random copolymer (random copolymer containing propylene and other copolymer components other than propylene as copolymer components) and the density of the above surface roughening material is preferably 0.04 g / cm 3 ~0.07 g / cm 3 In the range. In this case, during the process of cooling and solidifying the molten mixed resin, the difference in volume shrinkage rate between the above random copolymer and the surface roughening material becomes larger. Therefore, the unevenness of the surface 7a of the innermost layer becomes larger, and the surface 7a of the innermost layer can be more effectively roughened, thereby further improving the slidability.

[0100] In addition, the difference between the melt density of the above random copolymer (random copolymer containing propylene and other copolymer components other than propylene as copolymer components) and the melt density of the above surface roughening material is preferably 0.3 g / cm 3 or less.

[0101] The content rate of the surface roughening material in the innermost layer 7 of the above sealing layer is preferably set at 1% by mass to 30% by mass. In this case, even if the content rate of the lubricant in the innermost layer 7 is 1000 ppm or less, excellent moldability can be ensured. In addition, by making the content rate of the lubricant in the innermost layer 7 greater than 0 ppm and 1000 ppm or less as described above, it is more difficult for white powder to appear on the surface 7a of the innermost layer 7 of the sealing layer of the packaging material. Among them, the content rate of the surface roughening material in the innermost layer 7 of the above sealing layer is particularly preferably set at 1% by mass to 20% by mass. In addition, the content rate of the lubricant in the innermost layer 7 is preferably set at greater than 0 ppm and 900 ppm or less, and more preferably set at 10 ppm to 600 ppm.

[0102] As the above lubricant, there is no particular limitation, and it is preferably one or more lubricants selected from the group consisting of fatty acid amides, waxes, silicones, and paraffins. Among them, as the above lubricant, fatty acid amides are particularly preferably used. As the above fatty acid amides, there is no particular limitation, and for example, erucamide, behenamide, etc. can be cited.

[0103] In the present invention, within the range not impairing the effects of the present invention, an anti-blocking agent may also be contained in the above-mentioned innermost layer 7 (see Example 10).

[0104] In the present invention, the center line average roughness Ra of the surface 7a of the above-mentioned innermost layer 7 is set to 0.05 μm to 1 μm, and among them, the center line average roughness Ra of the surface 7a of the above-mentioned innermost layer 7 is preferably set to 0.1 μm to 1 μm. In addition, the thickness of the above-mentioned innermost layer 7 is preferably set to 2 μm to 40 μm.

[0105] In the case where the above-mentioned sealing layer 3 adopts the structure having the above-mentioned first intermediate layer 8, as the resin constituting the first intermediate layer 8, an elastomer-modified olefin resin is preferably used. The above-mentioned elastomer-modified olefin resin (polypropylene block copolymer) preferably contains an elastomer-modified homopolypropylene or / and an elastomer-modified random copolymer. The above-mentioned elastomer-modified random copolymer is an elastomer-modified body of a random copolymer containing "propylene" and "other copolymerization components other than propylene" as copolymerization components. As the above-mentioned "other copolymerization components other than propylene", there is no particular limitation, and for example, olefin components such as ethylene, 1-butene, 1-hexene, 1-pentene, 4-methyl-1-pentene, and butadiene can be cited. As the above-mentioned elastomer, there is no particular limitation, and an olefin-based thermoplastic elastomer is preferably used. As the above-mentioned olefin-based thermoplastic elastomer, there is no particular limitation, and for example, EPR (ethylene propylene rubber), propylene-butene elastomer, propylene-butene-ethylene elastomer, EPDM (ethylene-propylene-diene rubber), etc. can be cited. Among them, EPR (ethylene propylene rubber) is preferably used.

[0106] Regarding the above-mentioned elastomer-modified olefin resin, as the "elastomer modification" method, it can be a method of graft-polymerizing an elastomer, a method of adding an elastomer to an olefin resin (homopolypropylene or / and the above-mentioned random copolymer), or other modification methods.

[0107] In addition, in the case where the above-mentioned sealing layer 3 adopts the structure having the above-mentioned first intermediate layer 8, it is preferable to contain a lubricant in the first intermediate layer 8. As this lubricant, the same substances as those exemplified as the lubricants contained in the above-mentioned innermost layer 7 can be cited. In addition, the thickness of the above-mentioned first intermediate layer 8 is preferably set to 10 μm to 60 μm.

[0108] When the above-mentioned sealing layer 3 has the structure with the above-mentioned second intermediate layer 9, as the resin constituting the second intermediate layer 9, a random copolymer containing "propylene" and "other copolymerization components other than propylene" as copolymerization components is preferably used. Regarding the above-mentioned random copolymer, there is no particular limitation on the above-mentioned "other copolymerization components other than propylene". For example, olefin components such as ethylene, 1-butene, 1-hexene, 1-pentene, 4-methyl-1-pentene, and butadiene can be cited.

[0109] In addition, when the above-mentioned sealing layer 3 has the structure with the above-mentioned second intermediate layer 9, it is preferable that a lubricant is contained in the second intermediate layer 9. As the lubricant, the same substances as those exemplified as the lubricants contained in the innermost layer 7 can be cited. In addition, the thickness of the second intermediate layer 9 is preferably set to 2 μm to 40 μm.

[0110] In the present invention, as the heat-resistant resin constituting the above-mentioned heat-resistant resin layer (outer layer) 2, a heat-resistant resin that does not melt at the heat-sealing temperature when heat-sealing the outer packaging material is used. As the above-mentioned heat-resistant resin, a heat-resistant resin having a melting point 10 °C or more higher than the melting point of the sealing layer 3 is preferably used, and a heat-resistant resin having a melting point 20 °C or more higher than the melting point of the sealing layer 3 is particularly preferably used.

[0111] There is no particular limitation on the above-mentioned heat-resistant resin layer (outer layer) 2. For example, polyamide films such as nylon films, polyester films, etc. can be cited, and their stretched films are preferably used. Among them, as the above-mentioned heat-resistant resin layer 2, 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 naphthalate (PEN) film is particularly preferably used. There is no particular limitation on the above-mentioned nylon film. For example, nylon 6 film, nylon 66 film, MXD nylon film, etc. can be cited. It should be noted that the above-mentioned heat-resistant resin layer 2 can be formed of a single layer, or can also be formed of, for example, multiple layers including a polyester film / polyamide film (multiple layers including a PET film / nylon film, etc.). It should be noted that in the case of the above-mentioned multiple layers, the polyester film side can be arranged on the outermost side.

[0112] The thickness of the above-mentioned outer layer 2 is preferably 2 μm to 50 μm. When using a polyester film, the thickness is preferably 5 μm to 40 μm, and when using a nylon film, the thickness is preferably 15 μm to 50 μm. By setting it to be above the above-mentioned preferred lower limit value, sufficient strength as an outer packaging material can be ensured, and by setting it to be below the above-mentioned preferred upper limit value, the stress during forming such as bulging forming and drawing forming can be reduced, thereby improving the formability.

[0113] In the present invention, the above-mentioned metal foil layer 4 functions to impart gas barrier properties (preventing the intrusion of oxygen and moisture) to the outer packaging material 1. The above-mentioned metal foil layer 4 is not particularly limited, and for example, aluminum foil, SUS foil (stainless steel foil), copper foil, nickel foil, etc. can be cited. Among them, aluminum foil is preferably used. The thickness of the above-mentioned metal foil layer 4 is preferably 15 μm to 100 μm. By making the thickness of the above-mentioned metal foil layer 4 15 μm or more, it is possible to prevent the generation of pinholes during rolling when manufacturing the metal foil, and by making the thickness of the above-mentioned metal foil layer 4 100 μm or less, it is possible to reduce the stress during forming such as bulging forming and deep drawing forming, thereby improving the formability. Among them, the thickness of the above-mentioned metal foil layer 4 is more preferably 15 μm to 45 μm. In addition, as the above-mentioned aluminum foil, A8079-O aluminum foil material and A8021-O aluminum foil material specified in JISH4160:2006 are preferably used.

[0114] For the above-mentioned metal foil layer 4, it is preferable to perform a chemical conversion treatment on at least the inner surface (the surface on the side of the second adhesive layer 6). By performing such a chemical conversion treatment, it is possible to sufficiently prevent the corrosion of the metal foil surface caused by the contents (such as the electrolyte of the battery). As such a chemical conversion treatment, for example, chromate treatment, etc. can be cited.

[0115] The above-mentioned first adhesive layer (outer adhesive layer) 5 is not particularly limited, and for example, a polyurethane polyolefin adhesive layer, a polyurethane adhesive layer, a polyester polyurethane adhesive layer, a polyether polyurethane adhesive layer, etc. can be cited. The thickness of the above-mentioned first adhesive layer 5 is preferably set to 1 μm to 6 μm.

[0116] The above-mentioned second adhesive layer (inner adhesive layer) 6 is not particularly limited, and for example, the layers exemplified as the above-mentioned first adhesive layer 5 can be used, and a polyolefin-based adhesive with less swelling caused by the electrolyte is preferably used. Among them, an acid-modified polyolefin-based adhesive is particularly preferably used. As the above-mentioned acid-modified polyolefin-based adhesive, for example, maleic acid-modified polypropylene adhesive, fumaric acid-modified polypropylene adhesive, etc. can be cited. The thickness of the above-mentioned second adhesive layer 6 is preferably set to 1 μm to 5 μm.

[0117] In the present invention, by having the above structure, the amount of the lubricant present (adhered) on the surface 7a of the innermost layer 7 of the sealing layer 3 preferably becomes 0.1 μg / cm 2 ~0.6 μg / cm 2 In the range. Among them, the amount of the lubricant present on the surface 7a of the innermost layer 7 is more preferably in the range of 0.1 μg / cm 2 ~0.3 μg / cm 2 In the range.

[0118] In addition, in the present invention, with the above-described configuration, the amount of lubricant present on the surface (outer surface) of the outer layer 2 is preferably 0.1 μg / cm 2 to 0.6 μg / cm 2 . Among them, the amount of lubricant present on the surface of the outer layer 2 is more preferably in the range of 0.1 μg / cm 2 to 0.3 μg / cm 2 .

[0119] In addition, in the present invention, with the above-described configuration, the coefficient of kinetic friction of the surface 7a of the innermost layer 7 of the sealing layer 3 is preferably 0.3 or less.

[0120] By forming (deep drawing, bulging, etc.) the outer packaging material 1 for the power storage device of the present invention, an outer packaging case 10 for the power storage device can be obtained (see Figure 5 ). It should be noted that the outer packaging material 1 of the present invention can also be used directly without forming (see Figure 5 ).

[0121] One embodiment of the power storage device 30 constituted by using the outer packaging material 1 of the present invention is shown in Figure 4 . This power storage device 30 is a lithium ion secondary battery. In this embodiment, as shown in Figure 4 , 5 , the outer packaging member 15 is composed of a case 10 obtained by forming the outer packaging material 1 and a flat outer packaging material 1 that has not been formed. And, in the storage recess of the outer packaging case 10 obtained by forming the outer packaging material 1 of the present invention, a power storage device main body (electrochemical element, etc.) 31 having a substantially rectangular parallelepiped shape is stored. The outer packaging material 1 of the present invention is arranged above the power storage device main body 31 without forming, with its inner layer 3 side being the inner side (lower side), and the peripheral edge of the inner layer 3 of the flat outer packaging material 1 and the inner layer 3 of the flange portion (sealing peripheral edge portion) 29 of the above outer packaging case 10 are hermetically joined by heat sealing to seal it, thereby constituting the power storage device 30 of the present invention (see Figure 4 , 5 ). It should be noted that the inner surface of the storage recess of the above outer packaging case 10 becomes the inner layer (sealing layer) 3, and the outer surface of the storage recess becomes the outer layer (heat-resistant resin layer) 2 (see Figure 5 ).

[0122] Figure 4In this case, a heat-sealed portion 39 is formed by joining (welding) the peripheral portion of the above-described outer packaging material 1 and the flange portion (sealing peripheral portion) 29 of the above-described outer packaging case 10. It should be noted that in the above-described power storage device 30, the front end portion of the tab lead connected to the power storage device main body portion 31 is led out to the outside of the outer packaging member 15, but is omitted in the drawing.

[0123] The above-described 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, and a capacitance main body portion.

[0124] The width of the above-described heat-sealed portion 39 is preferably set to 0.5 mm or more. By setting it to 0.5 mm or more, reliable sealing can be achieved. Among them, the width of the above-described heat-sealed portion 39 is preferably set to 3 mm to 15 mm.

[0125] In the above-described embodiment, the outer packaging member 15 has a structure including the outer packaging case 10 formed by molding the outer packaging material 1 and the planar outer packaging material 1 (refer to Figure 4 , 5 ), but is not particularly limited to such a combination. For example, the outer packaging member 15 may have a structure including a pair of outer packaging materials 1, or may have a structure including a pair of outer packaging cases 10.

[0126] Examples

[0127] Next, specific examples of the present invention will be described, but the present invention is not particularly limited to these examples.

[0128] <Example 1>

[0129] A chemical conversion treatment liquid containing phosphoric acid, polyacrylic acid (acrylic resin), chromium (III) salt compound, water, and alcohol is coated on both surfaces of an aluminum foil 4 having a thickness of 40 μm, and then dried at 180 °C to form a chemical conversion film. The chromium adhesion amount of this chemical conversion film is 10 mg / m per side 2 .

[0130] Next, a biaxially stretched nylon 6 film 2 having a thickness of 25 μm is dry-laminated (bonded) to one surface of the aluminum foil 4 that has completed the above-described chemical conversion treatment via a two-component curable polyurethane-based adhesive 5.

[0131] Next, in a manner of laminating three layers in sequence, a second intermediate layer film (second intermediate layer) 9 with a thickness of 6 μm (which contains ethylene-propylene random copolymer and 500 ppm of erucamide), a first intermediate layer film (first intermediate layer) 8 with a thickness of 28 μm (which contains an elastomer-modified olefin resin (block PP) and 500 ppm of erucamide), and an innermost layer film (innermost layer) 7 with a thickness of 6 μm (which contains ethylene-propylene random copolymer, 1.0 mass% of high-density polyethylene resin powder (surface roughening material) and 500 ppm of erucamide), co-extrusion is carried out using a T-die, thereby obtaining a sealing film (second intermediate layer film 9 / first intermediate layer film 8 / innermost layer film 7) 3 with a thickness of 40 μm formed by laminating the above three layers. After that, via a two-component curable maleic acid-modified polypropylene adhesive 6, the surface of the second intermediate layer film 9 of the sealing film 3 is laminated on the other surface of the above-mentioned dry-laminated aluminum foil 4, and it is pressed by sandwiching it between a rubber nip roll and a laminating roll heated to 100 °C, thereby performing dry lamination. After that, it is cured (heated) at 40 °C for 10 days, thereby obtaining Figure 2 The outer packaging material 1 for a power storage device having the structure shown. The center line average roughness Ra of the surface 7a of the innermost layer 7 of the sealing layer 3 of the obtained outer packaging material 1 for a power storage device is 0.13 μm.

[0132] It should be noted that, as the above two-component curable maleic acid-modified polypropylene adhesive, an adhesive solution formed by mixing 100 mass parts of maleic acid-modified polypropylene (melting point: 80 °C, acid value: 10 mgKOH / g) as the main agent, 8 mass parts of the isocyanurate of hexamethylene diisocyanate (NCO content: 20 mass%) as the curing agent, and a solvent is used, and the adhesive solution is coated on the other surface of the above-mentioned aluminum foil 4 at a solid content coating amount of 2 g / m 2 in such a manner, and then heated and dried, and then laminated on the surface of the second intermediate layer film 9 of the above-mentioned sealing film 3.

[0133] For the above-mentioned high-density polyethylene resin (surface roughening material), the MFR at 190 °C is 0.2 g / 10 minutes, and the density is 0.963 g / cm 3 , and the expansion is 40%. The above-mentioned high-density polyethylene resin is manufactured using a Phillips catalyst by a slurry circulation method.

[0134] <Example 2>

[0135] Except that the content of the high-density polyethylene resin (surface roughening material) in the innermost layer film (innermost layer) 7 is changed from 1.0 mass% to 5.0 mass%, according to the same operation as in Example 1, the Figure 2 outer packaging material 1 for a power storage device having the structure shown is obtained.

[0136] <Example 3>

[0137] As the lubricant contained in the second intermediate layer film 9, the first intermediate layer film 8, and the innermost layer film 7, erucamide is replaced with behenic acid amide, and other than that, according to the same operation as in Example 2, Figure 2 the outer packaging material 1 for a power storage device having the structure shown is obtained.

[0138] <Example 4>

[0139] Except that the content rate of erucamide in the innermost layer film (innermost layer) 7 is changed from 500 ppm to 1000 ppm, according to the same operation as in Example 2, Figure 2 the outer packaging material 1 for a power storage device having the structure shown is obtained.

[0140] <Example 5>

[0141] Except that the content rate of the high-density polyethylene resin (surface roughening material) in the innermost layer film (innermost layer) 7 is changed from 1.0 mass% to 10.0 mass%, according to the same operation as in Example 1, Figure 2 the outer packaging material 1 for a power storage device having the structure shown is obtained.

[0142] <Example 6>

[0143] Except that the content rate of the high-density polyethylene resin (surface roughening material) in the innermost layer film (innermost layer) 7 is changed from 1.0 mass% to 15.0 mass%, according to the same operation as in Example 1, Figure 2 the outer packaging material 1 for a power storage device having the structure shown is obtained.

[0144] <Example 7>

[0145] Except that the content rate of the high-density polyethylene resin (surface roughening material) in the innermost layer film (innermost layer) 7 is changed from 1.0 mass% to 20.0 mass%, according to the same operation as in Example 1, Figure 2 the outer packaging material 1 for a power storage device having the structure shown is obtained.

[0146] <Example 8>

[0147] Except that the content rate of the high-density polyethylene resin (surface roughening material) in the innermost layer film (innermost layer) 7 is changed from 1.0 mass% to 30.0 mass%, according to the same operation as in Example 1, Figure 2 the outer packaging material 1 for a power storage device having the structure shown is obtained.

[0148] <Example 9>

[0149] Except for changing the content rate of the high-density polyethylene resin (surface roughening material) in the innermost layer film (innermost layer) 7 from 1.0% by mass to 35.0% by mass, the same operations as in Example 1 were performed to obtain Figure 2 the outer packaging material 1 for an electric storage device having the structure shown.

[0150] <Example 10>

[0151] Except for further containing 2500 ppm of acrylic beads as an anti-blocking agent (AB agent) in the innermost layer film (innermost layer) 7, the same operations as in Example 3 were performed to obtain Figure 2 the outer packaging material 1 for an electric storage device having the structure shown.

[0152] <Example 11>

[0153] As the high-density polyethylene resin (surface roughening material) contained in the innermost layer film (innermost layer) 7, a high-density polyethylene resin (surface roughening material) having an MFR of 0.2 g / 10 minutes, a density of 0.945 g / cm 3 , an expansion ratio of 35, and manufactured using a Phillips catalyst by a slurry circulation method was used. Except for this, the same operations as in Example 4 were performed to obtain Figure 2 the outer packaging material 1 for an electric storage device having the structure shown.

[0154] <Example 12>

[0155] As the high-density polyethylene resin (surface roughening material) contained in the innermost layer film (innermost layer) 7, a high-density polyethylene resin (surface roughening material) having an MFR of 0.2 g / 10 minutes, a density of 0.955 g / cm 3 , an expansion ratio of 45, and manufactured using a Phillips catalyst by a slurry circulation method was used. Except for this, the same operations as in Example 5 were performed to obtain Figure 2 the outer packaging material 1 for an electric storage device having the structure shown.

[0156] <Example 13>

[0157] As the high-density polyethylene resin (surface roughening material) contained in the innermost layer film (innermost layer) 7, a high-density polyethylene resin (surface roughening material) having an MFR of 2 g / 10 minutes at 190 °C, a density of 0.954 g / cm 3 , an expansion ratio of 30, and manufactured using a Ziegler catalyst by a slurry circulation method was used. Except for this, the same operations as in Example 6 were performed to obtain Figure 2 the outer packaging material 1 for an electric storage device having the structure shown.

[0158] <Example 14>

[0159] As the high-density polyethylene resin (surface roughening material) contained in the innermost layer film (innermost layer) 7, a high-density polyethylene resin (surface roughening material) with an MFR of 3 g / 10 min at 190 °C, a density of 0.955 g / cm 3 , an expansion ratio of 20, and manufactured by a slurry circulation method using a Ziegler catalyst was used. Except for this, according to the same operation as in Example 7, the outer packaging material 1 for an electric storage device with the structure shown in Figure 2 was obtained.

[0160] <Example 15>

[0161] As the surface roughening material contained in the innermost layer film (innermost layer) 7, a low-density polyethylene resin with an MFR of 2 g / 10 min at 190 °C, a density of 0.921 g / cm 3 , an expansion ratio of 20, and manufactured by a gas-phase fluidized bed method using a Ziegler catalyst was used to replace the high-density polyethylene resin. Except for this, according to the same operation as in Example 5, the outer packaging material 1 for an electric storage device with the structure shown in Figure 2 was obtained.

[0162] <Example 16>

[0163] As the surface roughening material contained in the innermost layer film (innermost layer) 7, a low-density polyethylene resin with an MFR of 3 g / 10 min at 190 °C, a density of 0.915 g / cm 3 , an expansion ratio of 35, and manufactured by a high-pressure autoclave method using a peroxide catalyst was used to replace the high-density polyethylene resin. Except for this, according to the same operation as in Example 5, the outer packaging material 1 for an electric storage device with the structure shown in Figure 2 was obtained.

[0164] <Example 17>

[0165] As the sealing film, a sealing film (the first intermediate layer film 8 / the innermost layer film 7) 3 with a thickness of 40 μm is used (which is formed by co-extruding a first intermediate layer film (the first intermediate layer) 8 with a thickness of 32 μm containing an elastomer-modified olefin resin (block PP) and 500 ppm of erucic acid amide and an innermost layer film (the innermost layer) 7 with a thickness of 8 μm containing an ethylene-propylene random copolymer, 10.0 mass% of a high-density polyethylene resin (surface roughening material) and 500 ppm of erucic acid amide in a two-layer lamination manner in sequence using a T die, and then laminating the above two layers), and via a two-component curable maleic acid-modified polypropylene adhesive 6, the surface of the first intermediate layer film 8 of the sealing film 3 is laminated on the other side of the dry-laminated aluminum foil 4. Except for this, according to the same operation as in Example 1, Figure 1 the outer packaging material 1 for an electric storage device having the structure shown is obtained.

[0166] <Example 18>

[0167] As the sealing film, a sealing film (a sealing film formed only by the innermost layer film 7) 3 with a thickness of 40 μm is used (which is obtained by extruding a composition containing an ethylene-propylene random copolymer, 10.0 mass% of a high-density polyethylene resin (surface roughening material) and 500 ppm of erucic acid amide using a T die), and via a two-component curable maleic acid-modified polypropylene adhesive 6, the sealing film 3 is laminated on the other side of the dry-laminated aluminum foil 4. Except for this, according to the same operation as in Example 1, Figure 3 the outer packaging material 1 for an electric storage device having the structure shown is obtained.

[0168] <Comparative Example 1>

[0169] Except for forming a structure in which the innermost layer film (the innermost layer) 7 does not contain a surface roughening material (high-density polyethylene resin), according to the same operation as in Example 3, an outer packaging material for an electric storage device is obtained.

[0170] <Reference Example 1>

[0171] The content rate of erucic acid amide in the second intermediate layer film (the second intermediate layer) 9 is changed from 500 ppm to 1000 ppm, and the content rate of erucic acid amide in the first intermediate layer film (the first intermediate layer) 8 is changed from 500 ppm to 1000 ppm. As the innermost layer film (the innermost layer) 7, a film formed by containing an ethylene-propylene random copolymer, 1000 ppm of erucic acid amide and 2500 ppm of silica particles (anti-blocking agent) is used. Except for this, according to the same operation as in Example 1, an outer packaging material for an electric storage device is obtained.

[0172] <Reference Example 2>

[0173] Except that the content rate of erucamide in the first intermediate layer film (the first intermediate layer) 8 was changed from 1000 ppm to 2500 ppm, an outer packaging material for an electric storage device was obtained by the same operation as in Reference Example 1.

[0174] <Reference Example 3>

[0175] Except that the content rate of erucamide in the first intermediate layer film (the first intermediate layer) 8 was changed from 1000 ppm to 5000 ppm, an outer packaging material for an electric storage device was obtained by the same operation as in Reference Example 1.

[0176]

[0177]

[0178]

[0179]

[0180] It should be noted that in Examples 1 to 18, Comparative Example 1, and Reference Examples 1 to 3, the above-mentioned elastomer-modified olefin resin was formed from an EPR-modified homopolypropylene and an EPR-modified ethylene-propylene random copolymer. The above-mentioned EPR refers to ethylene-propylene rubber.

[0181] In addition, in the table, the following abbreviations represent the following resins respectively.

[0182] "Random PP"... ethylene-propylene random copolymer

[0183] "Block PP"... the above-mentioned elastomer-modified olefin resin (polypropylene block copolymer)

[0184] "AB agent"... anti-blocking agent

[0185] "Phillips"... Phillips catalyst

[0186] "Ziegler"... Ziegler catalyst

[0187] "Peroxide"... peroxide catalyst

[0188] "Slurry"... slurry circulation method.

[0189] For each of the outer packaging materials for electric storage devices obtained as described above, evaluation was carried out based on the following evaluation methods. The results are shown in Tables 1 to 4. It should be noted that the coefficient of kinetic friction of the innermost layer surface recorded in Tables 1 to 4 is the coefficient of kinetic friction measured in accordance with JIS K7125-1995 for the surface 7a of the innermost layer of each outer packaging material.

[0190] <Method for Measuring Center Line Average Roughness Ra of the Innermost Layer Surface of the Outer Packaging Material>

[0191] In accordance with JIS B0601 - 2001, use Mitsutoyo Corporation “SURFTEST SV600” to measure the center line average roughness Ra of the innermost layer surface of each outer packaging material for the storage battery device.

[0192] <Method for Evaluating the Amount of Lubricant Present on the Innermost Layer Surface of the Outer Packaging Material>

[0193] Cut out two rectangular test pieces with a length of 100 mm × a width of 100 mm from each outer packaging material for the storage battery device, then stack these two test pieces, and heat - seal the peripheral parts of their sealing layers with each other at a heat - seal temperature of 200 °C to make a bag. Use a syringe to inject 1 mL of acetone into the internal space of this bag, place it for 3 minutes in a state where the surface 7a of the innermost layer 7 of the sealing layer is in contact with acetone, and then extract the acetone in the bag. Use gas chromatography to measure and analyze the amount of lubricant contained in the extracted liquid, thereby obtaining the amount of lubricant (μg / cm 2 ) present on the innermost layer surface of the outer packaging material. That is, obtain the amount of lubricant on the surface of every 1 cm 2 of the innermost layer.

[0194] <Method for Evaluating the Amount of Lubricant Present on the Outer Layer Surface of the Outer Packaging Material>

[0195] Make a bag in such a way that the outer layer becomes the inner side of the bag, and make the surface of the outer layer contact with acetone. Except for this, perform the same operations as in the above “Method for Evaluating the Amount of Lubricant Present on the Innermost Layer Surface” to obtain the amount of lubricant (μg / cm 2 ) present on the outer layer surface of the outer packaging material. That is, obtain the amount of lubricant on the surface of every 1 cm 2 of the outer layer.

[0196] <Formability Evaluation Method>

[0197] Using a straight mold with an unrestricted forming depth, perform one-stage deep drawing forming on the outer packaging material under the following forming conditions, evaluate the formability for each forming depth (9 mm, 8 mm, 7 mm, 6 mm, 5 mm, 4 mm, 3 mm, 2 mm) one by one, and investigate the maximum forming depth (mm) at which good forming can be achieved without pinholes occurring at the corners. Regarding the determination, when the maximum forming depth is 6 mm or more, it is evaluated as "◎", when the maximum forming depth is 4 mm or more and less than 6 mm, it is evaluated as "○", and when the maximum forming depth is less than 4 mm, it is evaluated as "×". It should be noted that the presence or absence of pinholes can be investigated by visually observing the transmitted light through the pinholes.

[0198] (Forming conditions)

[0199] Forming die... Punch: 33.3 mm × 53.9 mm, Die: 80 mm × 120 mm, Corner R: 2 mm, Punch R: 1.3 mm, Die R: 1 mm

[0200] Anti-wrinkle pressure... Gauge pressure: 0.475 MPa, Actual pressure (calculated value): 0.7 MPa

[0201] Material... SC (carbon steel) material, only the punch R is chrome-plated.

[0202] <Method for evaluating the presence or absence of white powder>

[0203] Cut out a rectangular test piece with a length of 600 mm × a width of 100 mm from each outer packaging material for the energy storage device, and then place the obtained test piece on the test bench with the surface of the inner sealing layer 3 (i.e., the innermost surface 7a) facing up. Place a SUS-made hammer (with a mass of 1.3 kg and a contact surface size of 55 mm × 50 mm) wrapped with a black waste cloth to make the surface black on the upper surface of the test piece. In this state, pull the hammer along the horizontal direction parallel to the upper surface of the test piece at a pulling speed of 4 cm / second. Thus, pull the hammer while it is in contact with the upper surface of the test piece to move it within a range of 400 mm in length. By visually observing the waste cloth (black) on the contact surface of the hammer after the pulling movement, if white powder is clearly generated on the surface of the waste cloth (black), it is judged as "×", if only a little white powder is generated, it is judged as "△", and if almost no white powder or no white powder is confirmed, it is judged as "○". It should be noted that as the above-mentioned black waste cloth, use the "Anti-static sheet S SD25253100" manufactured by TRUSCO.

[0204] <Method for evaluating the presence or absence of whitening during forming>

[0205] After the outer packaging material is deep drawn and formed into a rectangular parallelepiped shape with a depth of 5 mm under the following forming conditions using a deep drawing forming tool made by AMADA Corporation, visually observe the surface (the surface of the sealing layer 3) inside the storage recess of the formed body, and evaluate the presence or absence of whitening and the degree of whitening based on the following criteria.

[0206] (Judgment Criteria)

[0207] Visually observe the formed body after forming. Judge the case where no whitening is confirmed or there is almost no whitening as "◎", the case with little whitening as "○", the case where whitening has occurred to a certain extent as "△", and the case where obvious whitening has occurred as "×".

[0208] (Forming Conditions)

[0209] Forming die... Punch: 33.3 mm × 53.9 mm, Die: 80 mm × 120 mm, Corner R: 2 mm, Punch R: 1.3 mm, Die R: 1 mm

[0210] Anti-wrinkle pressure... Gauge pressure: 0.475 MPa, Actual pressure (calculated value): 0.7 MPa

[0211] Material... SC (carbon steel) material, only the punch R is chrome-plated.

[0212] As can be seen from the table, for the outer packaging materials for electric energy storage devices of Examples 1 to 18 of the present invention, the formability is excellent, and it is not easy to expose white powder on the surface of the outer packaging material. In addition, whitening during forming is not likely to occur.

[0213] In contrast, for Comparative Example 1 without the surface roughening material, the formability is poor. In addition, in order to obtain a well-evaluated outer packaging material with a structure without the surface roughening material, it is necessary to increase the lubricant content in the sealing layer and contain an anti-blocking agent (AB agent) at a high content in the innermost layer as in Reference Examples 1 to 3. In the case of containing a large amount of anti-blocking agent in the innermost layer like this, when the outer packaging material is in a wound state, the anti-blocking agent is easily squeezed into the inner side, resulting in a decrease in sliding property and the anti-blocking agent is easily peeled off. In addition, for Reference Example 3 with the largest lubricant content in the sealing layer, white powder is significantly exposed on the surface of the outer packaging material.

[0214] Industrial Applicability

[0215] The outer packaging material for electric energy storage devices made using the sealing film related to the present invention and the outer packaging material for electric energy storage devices related to the present invention can be used as the outer packaging material for various electric energy storage devices. As specific examples, for example, it includes:

[0216] · Electrical energy storage devices such as lithium secondary batteries (lithium ion batteries, lithium polymer batteries, etc.);

[0217] · Lithium ion capacitors;

[0218] · Electric double layer capacitors;

[0219] · All-solid-state batteries; and so on.

[0220] In addition, as the electrical energy storage device related to the present invention, for example, various electrical energy storage devices exemplified above can be cited.

[0221] This application claims the priority of Japanese Patent Application No. 2016-212823 filed on October 31, 2016, the disclosure of which is directly incorporated herein by reference.

[0222] The terms and descriptions used herein are for explaining the embodiments related to the present invention, and the present invention is not limited thereto. Within the scope of the claims, any design changes are allowed as long as they do not depart from the gist thereof.

Claims

1. The outer packaging material for an electricity storage device, characterized in that, The outer packaging material for the electricity storage device includes a heat-resistant resin layer as the outer layer, a sealing layer as the inner layer, and a metal foil layer disposed between these two layers. The sealing layer includes one layer to multiple layers, and the innermost layer of the sealing layer contains a random copolymer, a surface roughening material, and a lubricant. The random copolymer contains propylene and other copolymerization components other than propylene as copolymerization components. The surface roughening material is formed of particles containing a thermoplastic resin. The average roughness Ra of the center line of the surface of the innermost layer is 0.05 μm to 1 μm. The content rate of the surface roughening material in the innermost layer of the sealing layer is 1% by mass to 35% by mass, and the content rate of the lubricant in the innermost layer is greater than 0 ppm and 1000 ppm or less. The difference between the molten density and the density of the surface roughening material is in the range of 0.15 g / cm 3 to 0.25 g / cm 3 .

2. The outer packaging material for a power storage device according to claim 1, wherein, The lubricant is one or more lubricants selected from the group consisting of fatty acid amides, waxes, silicones, and paraffins.

3. The outer packaging material for the power storage device according to claim 1 or 2, wherein, The sealing layer includes multiple layers.

4. The outer packaging material for the power storage device according to claim 3, wherein, The sealing layer includes the innermost layer and a first intermediate layer laminated on the surface of the innermost layer on the side of the metal foil layer. The first intermediate layer contains an elastomer-modified olefin resin. The elastomer-modified olefin resin includes an elastomer-modified homopolypropylene or / and an elastomer-modified random copolymer. The elastomer-modified random copolymer is an elastomer-modified body of a random copolymer containing propylene and other copolymerization components other than propylene as copolymerization components.

5. The outer packaging material for a power storage device according to claim 3, wherein, The sealing layer includes the innermost layer, a first intermediate layer laminated on the surface of the innermost layer on the side of the metal foil layer, and a second intermediate layer laminated on the surface of the first intermediate layer on the side of the metal foil layer. The first intermediate layer contains an elastomer-modified olefin resin. The elastomer-modified olefin resin includes an elastomer-modified homopolypropylene or / and an elastomer-modified random copolymer. The elastomer-modified random copolymer is an elastomer-modified body of a random copolymer containing propylene and other copolymerization components other than propylene as copolymerization components. The second intermediate layer contains a random copolymer containing propylene and other copolymerization components other than propylene as copolymerization components.

6. An outer packaging case for an electricity storage device, which is formed of a molded body of the outer packaging material for the electricity storage device according to any one of claims 1 to 5.

7. Energy storage device, characterized in that, The electricity storage device has: an electricity storage device main body; and an outer packaging member, which is formed of the outer packaging material for the electricity storage device according to any one of claims 1 to 5 and / or the outer packaging case for the electricity storage device according to claim 6, and the electricity storage device main body is externally packaged through the outer packaging member.

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