JP6943547B2 - Sealant film for exterior material of power storage device, exterior material for power storage device and its manufacturing method - Google Patents

Description

The present invention provides the exterior of a power storage device such as a battery or capacitor used in a portable device such as a smartphone or tablet, a hybrid vehicle, an electric vehicle, wind power generation, solar power generation, or a battery or capacitor used for storing electricity at night. The present invention relates to a sealant film used to form a material, and a method for manufacturing an exterior material for a power storage device using the sealant film.

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

In order to form such a three-dimensional shape in a good state without pinholes or breakage, it is required to improve the slipperiness of the surface of the inner sealant layer. The exterior resin film, the first adhesive layer, the chemical-treated aluminum foil, the second adhesive layer, and the sealant film are sequentially laminated to improve the slipperiness of the surface of the inner sealant layer and ensure good moldability. The sealant film is made of a random copolymer of propylene and α-olefin having an α-olefin content of 2 to 10% by weight, and contains 1000 to 5000 ppm of a lubricant. A certain laminated material for a secondary battery container has been proposed (see Patent Document 1).

Japanese Unexamined Patent Publication No. 2003-288865

However, in the above-mentioned conventional technique, it is difficult to control the amount of surface lubricant deposited depending on the heating retention time and storage period in the production process of the exterior material (laminated material), and although the slipperiness during molding is good, the lubricant is excessively applied to the surface. Due to the precipitation, the lubricant adheres and accumulates on the molding surface of the molding die when the exterior material is molded, and white powder (white powder due to the lubricant) is generated. When such white powder adheres and accumulates on the molding surface, it becomes difficult to perform good molding. Therefore, it is necessary to clean and remove the white powder every time the white powder adheres and accumulates. There is a problem that the productivity of the exterior material is lowered by cleaning and removing.

Of course, if the amount of lubricant added (lubricant content) is reduced, it is possible to suppress the adhesion and accumulation of white powder, but in this case, there is a problem that the amount of surface lubricant deposited is insufficient and the moldability deteriorates. Occurs. As described above, conventionally, it has been difficult to achieve both excellent moldability and suppression of white powder appearance on the surface of the exterior material.

The present invention has been made in view of such a technical background, and is excellent in moldability as well as being able to suppress a decrease in the amount of lubricant deposited on the surface of the exterior material, ensuring good slipperiness during molding, and being excellent in moldability. It is an object of the present invention to provide a sealant film for an exterior material of a power storage device, an exterior material for a power storage device, and a method for manufacturing the same, in which white powder is hard to appear on the surface.

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

[1] It is composed of two or more laminated bodies including a first non-stretched film layer and a second non-stretched film layer laminated on one surface of the first non-stretched film layer.
The first non-stretched film layer forms the innermost layer of the exterior material.
The first non-stretched film layer contains a random copolymer containing propylene as a copolymerization component and other copolymerization components other than propylene, and a lubricant.
The second non-stretched film layer contains a block copolymer containing propylene as a copolymerization component and other copolymerization components other than propylene, and a lubricant.
A sealant film for an exterior material of a power storage device, characterized in that 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 500 ppm to 5000 ppm. ..

[2] A second non-stretched film layer, a first non-stretched film layer laminated on one surface of the second non-stretched film layer, and a second laminated on the other surface of the second non-stretched film layer. It is composed of a laminate of three or more layers including one non-stretched film layer.
One of the first non-stretched film layers forms the innermost layer of the exterior material.
The first non-stretched film layer contains a random copolymer containing propylene as a copolymerization component and other copolymerization components other than propylene, and a lubricant.
The second non-stretched film layer contains a block copolymer containing propylene as a copolymerization component and other copolymerization components other than propylene, and a lubricant.
A sealant film for an exterior material of a power storage device, characterized in that 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 500 ppm to 5000 ppm. ..

[3] The lubricant-containing concentration in the second non-stretched film layer is 0.5 to 5 times the lubricant-containing concentration in the first non-stretched film layer forming the innermost layer of the exterior material, according to item 1 or 2 above. The sealant film for the exterior material of the power storage device described.

[4] An exterior for a power storage device, which includes an inner sealant layer made of the sealant film according to any one of items 1 to 3 above, and a metal foil layer laminated on one side of the inner sealant layer. Material.

[5] It is characterized by including a heat-resistant resin layer as an outer layer, an inner sealant layer made of the sealant film according to any one of items 1 to 3 above, and a metal foil layer arranged between both layers. Exterior material for power storage devices.

[6] lubricant amount existing on the surface of the first non-oriented film layer forming the innermost layer of the outer package is described in the preceding paragraph 4 or 5 is in the range of 0.1μg / cm ² ~1.0μg / cm ² Exterior material for power storage devices.

[7] An exterior case for a power storage device made of a molded body of the exterior material according to any one of items 4 to 6 above.

[8] A step of preparing a laminate in which the sealant film according to any one of the above items 1 to 3 and a metal foil are laminated via a first adhesive.
A method for manufacturing an exterior material for a power storage device, which comprises an aging step of heat-treating the laminate to obtain an exterior material for the power storage device.

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

[10] A heat-resistant resin film is laminated on one surface of the metal foil via a second adhesive, and any one of the above items 1 to 3 is laminated on the other surface of the metal foil via a first adhesive. A step of preparing a laminate having a structure in which the sealant films described in the above are laminated, and
A method for manufacturing an exterior material for a power storage device, which comprises an aging step of heat-treating the laminate to obtain an exterior material for the power storage device.

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

[12] The amount of lubricant present on the surface of the first non-stretched film layer forming the innermost layer of the exterior material for a power storage device obtained by heat treatment is 0.1 μg / cm ^{2 to} 1.0 μg / cm ² . The method for manufacturing an exterior material for a power storage device according to any one of items 8 to 11 above, which is within the range.

In the inventions of [1] and [2], a decrease in the amount of lubricant present (precipitated) on the surface of the exterior material after the aging treatment (the surface 7a of the innermost layer of the inner sealant layer) can be suppressed, which is good at the time of molding. The slipperiness can be ensured and the moldability is excellent, and white powder is hard to appear on the surface of the exterior material (the surface 7a of the innermost layer of the inner sealant layer). Further, since the amount of lubricant existing on the surface of the exterior material after the aging treatment does not change even if it receives a heat history during transportation or storage, it is possible to provide an exterior material having excellent moldability in a stable manner. It becomes.

In the invention of [3], the lubricant-containing concentration in the second non-stretched film layer is 0.5 to 5 times the lubricant-containing concentration in the first non-stretched film layer forming the innermost layer of the exterior material. At the time of aging treatment, the interface between the innermost first unstretched film layer 7 and the second unstretched film layer 8 due to the lubricant concentration gradient of the lubricant (both film layers 7) is 0.5 times or more. , 8) can be suppressed, and if it is 5 times or less, the interface due to the lubricant concentration gradient of the lubricant from the second non-stretched film layer 8 to the innermost first non-stretched film layer 7. The amount of lubricant present on the surface 7a of the first unstretched film layer, which can suppress the intensive movement to (the interface between the two film layers 7 and 8) and form the innermost layer of the exterior material after the aging treatment, is 0. it becomes possible to control the range of ^{1μg / cm 2 ~1.0μg / cm 2} .

In the inventions of [4] and [5], a decrease in the amount of lubricant present (precipitated) on the surface of the exterior material (surface 7a of the innermost layer of the inner sealant layer) can be suppressed, and good slipperiness during molding can be ensured. It is possible to provide an exterior material for a power storage device, which is excellent in moldability and hardly causes white powder to appear on the surface of the exterior material (the surface 7a of the innermost layer of the inner sealant layer).

Further, in the invention of [5], since the heat-resistant resin layer is further provided as the outer layer, it is possible to sufficiently secure the insulating property on the side opposite to the inner sealant layer in the metal foil layer, and the physical strength of the exterior material. And impact resistance can be improved.

According to the invention of [6], it is possible to provide an exterior material for a power storage device that exhibits better slipperiness during molding, can secure better moldability, and can prevent the appearance of white powder.

According to the invention of [7], it is possible to provide an outer case for a power storage device in which white powder is less likely to appear on the surface of the outer case (the surface of the innermost layer of the inner sealant layer) while being well molded.

In the inventions of [8] to [11], a decrease in the amount of lubricant (precipitated) present on the surface of the exterior material (surface 7a of the innermost layer of the inner sealant layer) can be suppressed, and good slipperiness during molding can be ensured. It is possible to manufacture an exterior material for a power storage device, which is excellent in moldability and hardly causes white powder to appear on the surface of the exterior material (the surface 7a of the innermost layer of the inner sealant layer).

Further, in the inventions of [10] and [11], since the heat-resistant resin layer is further provided as the outer layer, it is possible to sufficiently secure the insulating property of the metal foil layer on the opposite side to the inner sealant layer, and the exterior material can be used. Physical strength and impact resistance can be improved.

In the invention [12], since the lubricant amount existing on the outermost layer of the surface is in the range of ^{0.1μg / cm 2 ~1.0μg / cm 2} , thereby demonstrating a good sliding property with time of molding, a better It is possible to manufacture an exterior material for a power storage device that can ensure moldability and prevent the appearance 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 the power storage device does not change even if it receives a heat history during transportation or storage. It is possible to provide an exterior material having excellent moldability in a stable manner.

It is sectional drawing which shows one Embodiment of the exterior material for a power storage device which concerns on this invention. It is sectional drawing which shows the other embodiment of the exterior material for a power storage device which concerns on this invention. It is sectional drawing which shows one Embodiment of the power storage device which concerns on this invention. FIG. 3 is a perspective view showing an exterior material (planar shape), a power storage device main body, and an exterior case (molded body molded into a three-dimensional shape) constituting the power storage device in FIG. 3 in a separated state before heat sealing.

FIG. 1 shows a first embodiment of a sealant film for an exterior material of a power storage device according to the present invention. The sealant film 3 comprises a first non-stretched film layer 7 forming the innermost layer of the exterior material 1 and a second non-stretched film layer 8 laminated on one surface of the first non-stretched film layer 7. The first non-stretched film layer 7 is composed of a laminate containing the above-mentioned second non-stretched film layer 7 and contains a random copolymer containing propylene and other copolymerization components other than propylene as copolymerization components and a lubricant. The stretched film layer 8 contains a block copolymer containing propylene and other copolymerization components other than propylene as copolymerization components, and a lubricant.

Further, FIG. 2 shows a second embodiment of the sealant film for the exterior material of the power storage device according to the present invention. The sealant film 3 includes a second non-stretched film layer 8, a first non-stretched film layer 7 laminated on one surface of the second non-stretched film layer, and the other surface of the second non-stretched film layer. The first non-stretched film layer 7 is composed of a laminated body including the first non-stretched film layer 9 laminated in the above, and the one first non-stretched film layer 7 forms the innermost layer of the exterior material 1, and the first non-stretched film layer 7 is formed. The film layers 7 and 9 contain propylene and a random copolymer containing other copolymerization components other than propylene as a copolymerization component, and a lubricant, and the second non-stretched film layer 8 is a copolymerization component. It is a composition containing a block copolymer containing propylene and other copolymerization components other than propylene, and a lubricant.

The first non-stretched film layers 7 and 9 contain a random copolymer containing "propylene" and "other copolymerization components other than propylene" as copolymerization components, and a lubricant. Regarding the random copolymer, the "other copolymerization component other than propylene" is not particularly limited, but for example, ethylene, 1-butane, 1-hexene, 1-pentene, 4methyl-1. -In addition to olefin components such as pentene, butadiene and the like can be mentioned.

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

Then, in the sealant film 3 according to the present invention, the content concentration of the lubricant in the first non-stretched film layers 7 and 9 is set to 200 ppm to 3000 ppm, and the content concentration of the lubricant in the second non-stretched film layer 8 is 500 ppm to ~. It is important to set it to 5000 ppm. By satisfying such conditions, the lubricant existing in the first non-stretched film layer 7 moves into the second non-stretched film layer 8 when the aging treatment for curing the adhesive is performed. Since it is possible to suppress the amount of lubricant deposited on the surface of the exterior material (the surface 7a of the first non-stretched film layer which is the innermost layer), it is possible to secure good slipperiness during molding of the exterior material, which is excellent. Formability is obtained. If the concentration of the lubricant in the first non-stretched film layer 7 is less than 200 ppm, the amount of the lubricant present on the surface 7a of the innermost layer after the aging treatment for curing the adhesive is insufficient, and excellent moldability is obtained. If it exceeds 3000 ppm, white powder is remarkably generated on the surface 7a of the innermost layer after the aging treatment for curing the adhesive, and it is necessary to clean and remove the white powder. It causes a problem that productivity is lowered, and also causes a problem that an adhesive force with a metal foil layer is lowered and an electrolytic solution is easily contaminated when used as an exterior material. Further, when the content concentration of the lubricant in the second non-stretched film layer 8 is less than 500 ppm, the innermost first non-stretched film layer 7 to the second non-stretched film layer are subjected to the aging treatment for curing the adhesive. The lubricant easily moves to No. 8, the amount of lubricant present on the innermost surface 7a becomes insufficient, the slipperiness at the time of molding deteriorates, and when it exceeds 5000 ppm, an aging treatment for curing the adhesive is performed. At that time, the lubricant easily moves from the second non-stretched film layer 8 to the first non-stretched film layers 7 and 9, and white powder is contaminated in the apparatus during production. It is easy to reduce the adhesive strength and contaminate the electrolyte.

Above all, the content concentration of the lubricant in the first non-stretched 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. 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 sealant film 3 according to the present invention, the lubricant-containing concentration in the second non-stretched film layer 8 is 0.5 times the lubricant-containing concentration in the first non-stretched film layer 7 forming the innermost layer of the exterior material 1. A configuration of 5 times is preferable. When it is 0.5 times or more, it depends on the lubricant concentration gradient of the lubricant from the first non-stretched film layer 7 to the second non-stretched film layer 8 of the innermost layer when the aging treatment for curing the adhesive is performed. Concentrated movement to the interface (the interface between the two film layers 7 and 8) can be suppressed, the amount of lubricant present on the innermost surface 7a is sufficient, and better moldability can be obtained. If it is less than twice, the interface due to the lubricant concentration gradient of the lubricant from the second non-stretched film layer 8 to the innermost first non-stretched film layer 7 when the aging treatment for curing the adhesive is performed (both). Concentrated movement to the interface of the film layers 7 and 8) can be suppressed, and fluctuations in the lubricant content of the innermost first unstretched film layer 7 can be sufficiently suppressed. Above all, the lubricant-containing concentration in the second non-stretched film layer 8 is 1.0 to 3.0 times the lubricant-containing concentration in the first non-stretched film layer 7 forming the innermost layer of the exterior material 1. Is more preferable.

The lubricant is not particularly limited, and examples thereof include saturated fatty acid amides, unsaturated fatty acid amides, substituted amides, methylol amides, saturated fatty acid bisamides, unsaturated fatty acid bisamides, fatty acid ester amides, and aromatic bisamides. Can be mentioned.

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

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

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

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

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

The thickness of the sealant film 3 is preferably set to 10 μm to 100 μm. When it is set to 10 μm or more, the occurrence of pinholes can be sufficiently prevented, and when it is set to 100 μm or less, the amount of resin used can be reduced and the cost can be reduced.

When the two-layer laminated structure of FIG. 1 is adopted as the sealant film 3, the ratio of the thickness of the two layers is the thickness of the first non-stretched film layer 7 / the thickness of the second non-stretched film layer 8 = 5. It is preferably set in the range of ~ 90/95 to 10, and above all, the thickness of the first unstretched film layer 7 / the thickness of the second unstretched film layer 8 = 5 to 40/95 to 60. It is particularly preferable to set it.

Further, when the three-layer laminated structure of FIG. 2 is adopted as the sealant film 3, the ratio of the thickness of the three layers is the thickness of the first non-stretched film layer 7 / the thickness of the second non-stretched film layer 8. / The thickness of the first non-stretched film layer 9 is preferably set in the range of 5 to 45/90 to 10/5 to 45, and above all, the thickness of the first non-stretched film layer 7 / the second non-stretched film layer 7 is set. It is particularly preferable that the thickness of the film layer 8 / the thickness of the first unstretched film layer 9 is set in the range of 5 to 20/90 to 60/5 to 20.

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

By incorporating the anti-blocking agent (particles) into the first non-stretched film layer 7 forming the innermost layer, microprojections are formed on the surface 7a of the innermost layer 7 to reduce the contact area between the films and the sealant film. Blocking between each other can be suppressed. Further, by containing an anti-blocking agent (particles) together with the lubricant, the slipperiness at the time of molding can be further improved.

The sealant film 3 is preferably manufactured by a molding method such as multi-layer extrusion molding, inflation molding, or T-die cast film molding.

The exterior material 1 for a power storage device according to the present invention is produced by using a sealant film having the above configuration. A laminated body having a structure in which the sealant film 3 of the first embodiment and the metal foil 4 are laminated via a first adhesive (inner adhesive) 6 is prepared. At this time, the second non-stretched film layer 8 of the sealant film 3 comes into contact with the first adhesive 6 (see FIG. 1). Next, by heat-treating the obtained laminate (performing an aging treatment), the exterior material 1 for a power storage device of the present invention having the configuration shown in FIG. 1 can be obtained.

Further, the heat-resistant resin film (outer layer) 2 is laminated on one surface of the metal foil 4 via the second adhesive (outer adhesive) 5, and the first adhesive is applied to the other surface of the metal foil 4. A laminated body having a structure in which the sealant film 3 of the second embodiment is laminated via the (inner adhesive) 6 is prepared. At this time, the first non-stretched film layer 9 of the sealant film 3 comes into contact with the first adhesive (inner adhesive) 6 (see FIG. 2). That is, the other first non-stretched film layer 7 of the sealant film 3 forms the innermost layer (see FIG. 2). Next, by heat-treating the obtained laminate (performing an aging treatment), the exterior material 1 for a power storage device of the present invention having the configuration shown in FIG. 2 can be obtained.

The first adhesive (inner adhesive) 6 is not particularly limited, and examples thereof include a thermosetting adhesive. The second adhesive (outer adhesive) 5 is not particularly limited, and examples thereof include a thermosetting adhesive. The thermosetting adhesive is not particularly limited, and examples thereof include an olefin-based adhesive, an epoxy-based adhesive, and an acrylic-based adhesive.

The heating temperature of the aging treatment is preferably set to 65 ° C. or lower, and above all, from the viewpoint of maintaining a suitable amount of the lubricant present on the surface 7a of the exterior material and the degree of curing of the adhesive, 35 ° C. to 45 ° C. It is more preferable to set to. Further, the heating time of the aging treatment varies depending on the type of adhesive, so it may be longer than the time when sufficient adhesive strength can be obtained according to the type of adhesive, but considering the lead time of the process. The heating time should be as short as possible as long as sufficient adhesive strength can be obtained.

The exterior material 1 for a power storage device of the present invention obtained through such an aging treatment has a heat-resistant resin layer (a heat-resistant resin layer) on one surface of the metal foil layer 4 via a second adhesive layer (outer adhesive layer) 5. The outer layer) 2 is laminated and integrated, and the inner sealant layer (sealant film) (inner layer) 3 is formed on the other surface of the metal foil layer 4 via the first adhesive layer (inner adhesive layer) 6. It is a laminated and integrated configuration (see FIGS. 1 and 2).

In the exterior material 1 for a power storage device obtained through the above aging treatment, the sealant film 3 used for manufacturing has a lubricant content of 200 ppm to 3000 ppm in the first unstretched film layer as described above, and the second Since the concentration of the lubricant in the non-stretched film layer is set to 500 ppm to 5000 ppm, the lubricant present on the surface 7a of the first non-stretched film layer 7 forming the innermost layer of the exterior material 1 for the power storage device after the aging treatment. the amount can be controlled in the range of ^{0.1μg / cm 2 ~1.0μg / cm 2} . Therefore, the obtained exterior material 1 for a power storage device can suppress a decrease in the amount of lubricant existing (precipitated) on the surface (surface 7a of the innermost layer of the inner sealant layer), and can secure good slipperiness during molding. In addition to being excellent in moldability, white powder is less likely to appear on the surface of the exterior material (the surface 7a of the innermost layer of the inner sealant layer).

In the exterior material 1 for a power storage device, the coefficient of kinetic friction of the surface 7a of the first unstretched film layer (innermost layer) 7 is preferably in the range of 0.10 to 0.50. When it is 0.50 or less, the slipperiness can be improved and good moldability can be ensured, and when it is 0.10 or more, the amount of bleeding of the lubricant on the surface 7a of the innermost layer can be reduced.

The exterior material 1 for a power storage device of the present invention is used, for example, as an exterior material for a lithium ion secondary battery. The exterior material 1 for a power storage device may be used as it is as an exterior material without being molded, or may be used as an exterior case 10 by being subjected to molding such as deep drawing molding or overhang molding. Good (see Figure 4).

In the exterior material 1 for a power storage device of the present invention, the inner sealant layer (inner layer) 3 has excellent chemical resistance to a highly corrosive electrolytic solution or the like used in a lithium ion secondary battery or the like. At the same time, it plays a role of imparting heat sealability to the exterior material.

Although the heat-resistant resin layer (base material layer; outer layer) 2 is not an essential constituent layer, it is second-bonded to the other surface of the metal foil layer 4 (the surface opposite to the inner sealant layer). It is preferable to adopt a structure in which the heat-resistant resin layer 2 is laminated via the agent layer (outer adhesive layer) 5 (see FIGS. 1 and 2). By providing such a heat-resistant resin layer 2, the insulating property on the other surface (the surface opposite to the inner sealant layer) of the metal foil layer 4 can be sufficiently ensured, and the physical strength of the exterior material 1 can be secured. And impact resistance can be improved.

As the heat-resistant resin constituting the heat-resistant resin layer (base material 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 heat-resistant resin, it is preferable to use a heat-resistant resin having a melting point higher than the melting point of the block copolymer constituting the second non-stretched film layer 8 by 10 ° C. or more, and form the second non-stretched film layer 8. It is particularly preferable to use a heat-resistant resin having a melting point of 20 ° C. or higher higher than the melting point of the block copolymer.

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

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

In the exterior material 1 for a power storage device of the present invention, the first non-stretched layer forming the innermost layer of the exterior material 1 for a power storage device is formed on the surface of the heat-resistant resin layer (outer layer) 2 on the opposite side of the metal foil layer 4. The lubricant contained in the film 7 is attached. This adhesive lubricant is transferred from the inner layer 3 by contact with the surface 7a of the inner sealant layer 3 in the wound state when the exterior material 1 for a power storage device obtained by laminating is aged in the wound state. It is a lumber. Deposition amount after the transfer is preferably in a range of ^{0.1μg / cm 2 ~0.8μg / cm 2} . When the amount of adhesion is within such a range, the moldability of the exterior material 1 for the power storage device can be improved. Among them, deposition amount after the transfer, and more preferably in the range of ^{0.1μg / cm 2 ~0.6μg / cm 2} , in the range of 0.15μg / cm ² ~0.45μg / cm ² Is particularly preferable. After the exterior material 1 for the power storage device is molded by deep drawing or the like, the transfer lubricant may be removed, left unattended, or disappears spontaneously. good.

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

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

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

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

The thickness of the first adhesive layer (inner adhesive layer) 6 is preferably set to 1 μm to 5 μm. Above all, from the viewpoint of thinning and weight reduction of the exterior material 1, the thickness of the inner adhesive layer 6 is particularly preferably set to 1 μm to 3 μm.

The exterior case (battery case, etc.) 10 can be obtained by molding the exterior material 1 of the present invention (deep drawing molding, overhang molding, etc.) (see FIG. 4). The exterior material 1 of the present invention can be used as it is without being subjected to molding (see FIG. 4).

FIG. 3 shows an embodiment of the power storage device 30 configured by using the exterior material 1 of the present invention. The power storage device 30 is a lithium ion secondary battery. In the present embodiment, as shown in FIGS. 3 and 4, the exterior member 15 is composed of the exterior case 10 obtained by molding the exterior material 1 and the flat exterior material 1. Thus, a substantially rectangular body-shaped power storage device main body (electrochemical element or the like) 31 is housed in the storage recess of the exterior case 10 obtained by molding the exterior material 1 of the present invention, and the power storage device main body 31 is housed. The exterior material 1 of the present invention is placed on the inner sealant layer 3 (first non-stretched) of the flat exterior material 1 with the inner sealant layer 3 side facing inward (lower side) without being molded. The peripheral edge of the film layer 7) and the inner sealant layer 3 (first unstretched film layer 7) of the flange portion (sealing peripheral edge) 29 of the outer case 10 are sealed and sealed by heat sealing. As a result, the power storage device 30 of the present invention is configured (see FIGS. 3 and 4). The inner surface of the accommodating recess of the outer case 10 is an inner sealant layer 3 (first non-stretched film layer 7), and the outer surface of the accommodating recess is a heat-resistant resin layer (outer layer) 2. (See Fig. 4).

In FIG. 3, 39 is a heat-sealed portion in which the peripheral edge portion of the exterior material 1 and the flange portion (sealing peripheral edge portion) 29 of the exterior case 10 are joined (welded). In the power storage device 30, the tip of the tab lead connected to the power storage device main body 31 is led out to the outside of the exterior member 15, but the illustration is omitted.

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

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

In the above embodiment, the exterior member 15 is composed of an exterior case 10 obtained by molding the exterior material 1 and a flat exterior material 1 (see FIGS. 3 and 4). The combination is not particularly limited, and for example, the exterior member 15 may be composed of a pair of flat exterior materials 1, or may be composed of a pair of exterior cases 10. You may.

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

< Reference example 1 >
A chemical conversion treatment solution consisting of phosphoric acid, polyacrylic acid (acrylic resin), chromium (III) salt compound, water, and alcohol was applied to both sides of an aluminum foil 4 having a thickness of 40 μm, and then dried at 180 ° C. , A chemical conversion film was formed. The amount of chromium adhered to this chemical conversion film was ^{10 mg / m 2 per side.}

Next, a biaxially stretched 6 nylon film 2 having a thickness of 25 μm was dry-laminated (bonded) on one surface of the chemical conversion-treated aluminum foil 4 via a two-component curable urethane adhesive 5.

Next, a 12 μm-thick first unstretched film 7 containing an ethylene-propylene random copolymer, 1000 ppm erucic acid amide and 2000 ppm silica particles (anti-blocking agent), an ethylene-propylene block copolymer and The second unstretched film 8 having a thickness of 28 μm containing 2500 ppm of erucic acid amide is co-extruded using a T-die so that two layers are laminated in this order, whereby these two layers are laminated. After obtaining a sealant film (first non-stretched film layer 7 / second non-stretched film layer 8) 3 having a thickness of 40 μm, eight surfaces of the second non-stretched film layer of the sealant film 3 are coated with a two-component curable polymer. It is dried by being laminated on the other surface of the aluminum foil 4 after the dry lamination via the acid-modified polypropylene adhesive 6, sandwiched between the rubber nip roll and the laminate roll heated to 100 ° C., and crimped. After laminating and then aging (heating) at 40 ° C. for 10 days, an exterior material 1 for a power storage device having the configuration shown in FIG. 1 was obtained.

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

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

<Example 2>
A chemical conversion treatment solution consisting of phosphoric acid, polyacrylic acid (acrylic resin), chromium (III) salt compound, water, and alcohol was applied to both sides of an aluminum foil 4 having a thickness of 40 μm, and then dried at 180 ° C. , A chemical conversion film was formed. The amount of chromium adhered to this chemical conversion film was ^{10 mg / m 2 per side.}

Next, a biaxially stretched 6 nylon film 2 having a thickness of 25 μm was dry-laminated (bonded) on one surface of the chemical conversion-treated aluminum foil 4 via a two-component curable urethane adhesive 5.

Next, a 6 μm-thick first unstretched film 7 containing an ethylene-propylene random copolymer, 1000 ppm erucic acid amide and 2000 ppm silica particles (anti-blocking agent), an ethylene-propylene block copolymer and A 28 μm-thick second unstretched film containing 2500 ppm erucic acid amide, an ethylene-propylene random copolymer, 1000 ppm erucic acid amide and 2000 ppm silica particles (anti-blocking agent). By co-extruding a 6 μm first unstretched film 9 with a T-die so that three layers are laminated in this order, a 40 μm-thick sealant film (first unstretched film) formed by laminating these three layers. After obtaining the film layer 7 / second non-stretched film layer 8 / first non-stretched film layer 9) 3, one of the first non-stretched film layers 9 surfaces of the sealant film 3 is coated with a two-component curable maleic acid. Dry-laminate by superimposing it on the other surface of the aluminum foil 4 after the dry-laminate via the modified polypropylene adhesive 6, sandwiching it between the rubber nip roll and the laminate roll heated to 100 ° C., and crimping it. Then, by aging (heating) at 40 ° C. for 10 days, the exterior material 1 for a power storage device having the configuration shown in FIG. 2 was obtained.

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

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

<Example 3>
An exterior material 1 for a power storage device having the configuration shown in FIG. 2 was obtained in the same manner as in Example 2 except that the concentration of erucic acid amide in the second unstretched film layer 8 before lamination was set to 1000 ppm. In the obtained exterior material 1 for a power storage device, the amount of lubricant present on the surface 7a of the innermost layer (first unstretched film layer 7) of the exterior material was 0.20 μg / cm ² (Table 1).

<Example 4>
An exterior material 1 for a power storage device having the configuration shown in FIG. 2 was obtained in the same manner as in Example 2 except that the concentration of erucic acid amide in the first unstretched film layers 7 and 9 before lamination was set to 500 ppm. .. In the obtained exterior material 1 for a power storage device, the amount of lubricant present on the surface 7a of the innermost layer (first unstretched film layer 7) of the exterior material was 0.15 μg / cm ² (Table 1).

<Example 5>
Example 2 except that the erucic acid amide content in the second non-stretched film layer 8 before laminating was set to 1000 ppm and the erucic acid amide content in the first non-stretched film layers 7 and 9 before laminating was set to 2000 ppm. In the same manner as above, the exterior material 1 for the power storage device having the configuration shown in FIG. 2 was obtained. In the obtained exterior material 1 for a power storage device, the amount of lubricant present on the surface 7a of the innermost layer (first unstretched film layer 7) of the exterior material was 0.35 μg / cm ² (Table 1).

<Example 6>
The storage storage having the configuration shown in FIG. 2 is the same as in Example 2 except that bechenic acid amide is used as the lubricant in the first non-stretched film layers 7 and 9 and the second non-stretched film layer 8 instead of the erucic acid amide. The exterior material 1 for the device was obtained. In the obtained exterior material 1 for a power storage device, the amount of lubricant present on the surface 7a of the innermost layer (first unstretched film layer 7) of the exterior material was 0.19 μg / cm ² (Table 1).

<Example 7>
The storage capacity shown in FIG. 2 is the same as in Example 2 except that oleic acid amide is used as the lubricant in the first non-stretched film layers 7 and 9 and the second non-stretched film layer 8 instead of erucic acid amide. The exterior material 1 for the device was obtained. In the obtained exterior material 1 for a power storage device, the amount of lubricant present on the surface 7a of the innermost layer (first unstretched film layer 7) of the exterior material was 0.50 μg / cm ² (Table 1).

<Example 8>
The storage capacity shown in FIG. 2 is the same as in Example 2 except that stearic acid amide is used as the lubricant in the first non-stretched film layers 7 and 9 and the second non-stretched film layer 8 instead of erucic acid amide. An exterior material 1 for a device was obtained. In the obtained exterior material 1 for a power storage device, the amount of lubricant present on the surface 7a of the innermost layer (first unstretched film layer 7) of the exterior material was 0.30 μg / cm ² (Table 1).

<Example 9>
An exterior material 1 for a power storage device having the configuration shown in FIG. 2 was obtained in the same manner as in Example 2 except that the concentration of erucic acid amide in the second unstretched film layer 8 before lamination was set to 4500 ppm. In the obtained exterior material 1 for a power storage device, the amount of lubricant present on the surface 7a of the innermost layer (first unstretched film layer 7) of the exterior material was 0.10 μg / cm ² (Table 1).

<Comparative example 1>
An exterior material for a power storage device was obtained in the same manner as in Example 1 except that the concentration of erucic acid amide in the second unstretched film layer 8 before lamination was set to 300 ppm. In the obtained exterior material 1 for a power storage device, the amount of lubricant present on the surface 7a of the innermost layer (first unstretched film layer 7) of the exterior material was 0.07 μg / cm ² (Table 1).

<Comparative example 2>
An exterior material for a power storage device was obtained in the same manner as in Example 2 except that the concentration of erucic acid amide in the second unstretched film layer 8 before lamination was set to 300 ppm. In the obtained exterior material 1 for a power storage device, the amount of lubricant present on the surface 7a of the innermost layer (first unstretched film layer 7) of the exterior material was 0.08 μg / cm ² (Table 1).

<Comparative example 3>
Example 2 except that the erucic acid amide content in the second non-stretched film layer 8 before laminating was set to 8000 ppm and the erucic acid amide content in the first non-stretched film layers 7 and 9 before laminating was set to 2000 ppm. In the same manner as above, an exterior material for a power storage device was obtained. In the obtained exterior material 1 for a power storage device, the amount of lubricant present on the surface 7a of the innermost layer (first unstretched film layer 7) of the exterior material was 1.31 μg / cm ² (Table 1).

<Comparative example 4>
Example 2 except that the erucic acid amide content in the second non-stretched film layer 8 before laminating was set to 1500 ppm and the erucic acid amide content in the first non-stretched film layers 7 and 9 before laminating was set to 8000 ppm. In the same manner as above, an exterior material for a power storage device was obtained. In the obtained exterior material 1 for a power storage device, the amount of lubricant present on the surface 7a of the innermost layer (first unstretched film layer 7) of the exterior material was 1.05 μg / cm ² (Table 1).

<Comparative example 5>
Example 2 except that the erucic acid amide content in the second non-stretched film layer 8 before laminating was set to 1500 ppm and the erucic acid amide content in the first non-stretched film layers 7 and 9 before laminating was set to 100 ppm. In the same manner as above, an exterior material for a power storage device was obtained. In the obtained exterior material 1 for a power storage device, the amount of lubricant present on the surface 7a of the innermost layer (first unstretched film layer 7) of the exterior material was 0.06 μg / cm ² (Table 1).

<Comparative Example 6>
Same as in Example 1 except that the erucic acid amide content in the second non-stretched film layer 8 before laminating was set to 100 ppm and the erucic acid amide content in the first non-stretched film layer 7 before laminating was set to 250 ppm. Then, an exterior material for a power storage device was obtained. In the obtained exterior material 1 for a power storage device, the amount of lubricant present on the surface 7a of the innermost layer (first unstretched film layer 7) of the exterior material was 0.02 μg / cm ² (Table 1).

<Comparative Example 7>
Example 2 except that the erucic acid amide content in the second non-stretched film layer 8 before laminating was set to 100 ppm and the erucic acid amide content in the first non-stretched film layers 7 and 9 before laminating was set to 250 ppm. In the same manner as above, an exterior material for a power storage device was obtained. In the obtained exterior material 1 for a power storage device, the amount of lubricant present on the surface 7a of the innermost layer (first unstretched film layer 7) of the exterior material was 0.02 μg / cm ² (Table 1).

<Comparative Example 8>
Example 2 except that the erucic acid amide content in the second non-stretched film layer 8 before laminating was set to 21000 ppm and the erucic acid amide content in the first non-stretched film layers 7 and 9 before laminating was set to 3500 ppm. In the same manner as above, an exterior material for a power storage device was obtained. In the obtained exterior material 1 for a power storage device, the amount of lubricant present on the surface 7a of the innermost layer (first unstretched film layer 7) of the exterior material was 3.20 μg / cm ² (Table 1).

<Comparative Example 9>
Example 2 except that the erucic acid amide content in the second non-stretched film layer 8 before laminating was set to 100 ppm and the erucic acid amide content in the first non-stretched film layers 7 and 9 before laminating was set to 3500 ppm. In the same manner as above, an exterior material for a power storage device was obtained. In the obtained exterior material 1 for a power storage device, the amount of lubricant present on the surface 7a of the innermost layer (first unstretched film layer 7) of the exterior material was 0.05 μg / cm ² (Table 1).

The exterior materials (aged) for each power storage device obtained as described above were evaluated based on the following evaluation methods. The results are shown in Table 1. The coefficient of kinetic friction shown in Table 1 is a coefficient of kinetic friction measured for the surface 7a of the innermost layer of the exterior material (aged) for each power storage device in accordance with JIS K7125-1995.

<Evaluation method for the amount of lubricant present on the surface of the innermost layer of the exterior material>
After cutting out two rectangular test pieces of 100 mm in length × 100 mm in width from the exterior material for each power storage device, these two test pieces are overlapped and the peripheral edges of each sealant layer are heat-sealed at a heat seal temperature of 200 ° C. A bag body was prepared by heat sealing. 1 mL of acetone was injected into the internal space of the bag using a syringe, and the surface of the innermost layer 7 of the sealant layer was left in contact with acetone for 3 minutes, and then the acetone in the bag was extracted. ^{The amount of lubricant (μg / cm 2} ) present on the surface of the innermost layer of the exterior material was determined 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 determined.

<Moldability evaluation method>
Using a straight mold with no molding depth, the exterior material is deep-drawn and one-stage molded under the following molding conditions, and for each molding depth (9 mm, 8 mm, 7 mm, 6 mm, 5 mm, 4 mm, 3 mm, 2 mm). The moldability was evaluated, and the maximum molding depth (mm) capable of performing good molding without any pinholes at the corners was investigated. Judgment is that the maximum molding depth of 5 mm or more is marked with "○", the maximum molding depth of 2 mm or more and less than 5 mm is marked with "Δ", and the maximum molding depth of less than 2 mm is marked with "x". ". The results are shown in Table 1. The presence or absence of pinholes was examined by visually observing the presence or absence of transmitted light transmitted through the pinholes.
(Molding condition)
Molding mold: Punch: 33.3 mm x 53.9 mm, Die: 80 mm x 120 mm, Corner R: 2 mm, Punch R: 1.3 mm, Die R: 1 mm
Wrinkle pressing pressure: Gauge pressure: 0.475 MPa, actual pressure (calculated value): 0.7 MPa
Material: SC (carbon steel) material, punch R only chrome plated.

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

<Comprehensive judgment>
Those whose moldability evaluation is "○" and whose presence / absence evaluation of white powder is also "○" are judged as "○" in the comprehensive judgment, and at least one of the moldability evaluation and the presence / absence evaluation of white powder is "×". Was judged as "x" in the comprehensive judgment.

As is clear from Table 1, the exterior materials for power storage devices of the present invention of Examples 1 to 9 configured by using the sealant film of the present invention are excellent in moldability and white powder is formed on the surface of the exterior material. It was difficult to express.

On the other hand, in Comparative Examples 1, 2, 5 to 7, and 9, which deviate from the specified range of the present invention, the moldability of the exterior material was not good, and the comparison deviated from the specified range of the present invention. In Examples 3, 4 and 8, white powder was remarkably generated on the surface of the exterior material.

Specific examples of the exterior material for a power storage device manufactured by using the sealant film according to the present invention and the exterior material for a power storage device according to the present invention are, for example.
-Used as an exterior material for various power storage devices such as lithium ion batteries (lithium ion batteries, lithium polymer batteries, etc.), lithium ion capacitors, and electric double-layer capacitors. Further, the power storage device according to the present invention includes an all-solid-state battery in addition to the power storage device exemplified above.

1 ... Exterior material for power storage device 2 ... Heat-resistant resin layer (outer layer)
3 ... Inner sealant layer (sealant film) (inner layer)
4 ... Metal leaf layer 5 ... Second adhesive layer (outer adhesive layer)
6 ... First adhesive layer (inner adhesive layer)
7 ... First non-stretched film layer (innermost layer)
7a ... Surface of first non-stretched film layer (surface of innermost layer of exterior material)
8 ... Second non-stretched film layer 9 ... First non-stretched film layer (metal foil layer side)
10 ... Exterior case (molded body) for power storage device
15 ... Exterior member 30 ... Power storage device 31 ... Power storage device main body

Claims (10)

An exterior material for a power storage device including a heat-resistant resin layer as an outer layer, an inner sealant layer made of a sealant film for the exterior material of the power storage device, and a metal foil layer arranged between both layers.
The sealant film for exterior materials includes a second non-stretched film layer, a first non-stretched film layer laminated on one surface of the second non-stretched film layer, and the other surface of the second non-stretched film layer. It is composed of a laminated body of three or more layers including a first unstretched film layer laminated in
One of the first non-stretched film layers forms the innermost layer of the exterior material.
The first non-stretched film layer contains a random copolymer containing propylene as a copolymerization component and other copolymerization components other than propylene, and a lubricant.
The second non-stretched film layer contains a block copolymer containing propylene as a copolymerization component and other copolymerization components other than propylene, and a 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 film layer is 500 ppm to 5000 ppm.
The lubricant-containing concentration in the second non-stretched film layer is 0.5 to 5 times the lubricant-containing concentration in the first non-stretched film layer forming the innermost layer of the exterior material and the metal foil layer side.
The metal foil layer and the inner sealant layer are adhered to each other via an inner adhesive layer.
The heat-resistant resin layer and the metal foil layer are adhered to each other via an outer adhesive layer .
Each of the first non-stretched film layers forming the innermost layer side and the metal foil layer side of the exterior material is a random copolymer containing propylene and other copolymerization components other than propylene as the same copolymerization component. , An exterior material for a power storage device, characterized in that the content concentration of the lubricant is the same. The first aspect of claim 1, wherein the lubricant-containing concentration in the second non-stretched film layer is 1 to 3 times the lubricant-containing concentration in the first non-stretched film layer forming the innermost layer and the metal foil layer side of the exterior material. Exterior material for power storage devices. Storage device according to claim 1 or 2 ranges lubricant amount existing on the surface of the first non-oriented film layer of 0.1μg / cm ² ~1.0μg / cm ² to form an innermost layer of the outer package Exterior material. The exterior for a power storage device according to claim 3, wherein the amount of lubricant present on the surface of the first non-stretched film layer forming the innermost layer of the exterior material ^{is in the range of 0.15 μg / cm 2 to} 0.45 μg / cm ^2. Material. An exterior case for a power storage device made of a molded body of the exterior material according to any one of claims 1 to 4. The method for manufacturing an exterior material for a power storage device according to any one of claims 1 to 4.
A step of preparing a laminate in which the sealant film for an exterior material and a metal foil are laminated via a first adhesive, and
A method for manufacturing an exterior material for a power storage device, which comprises an aging step of heat-treating the laminate to obtain an exterior material for the power storage device. The method for manufacturing an exterior material for a power storage device according to claim 6, wherein the first adhesive is a thermosetting adhesive. The method for manufacturing an exterior material for a power storage device according to any one of claims 1 to 4.
A heat-resistant resin film is laminated on one surface of the metal foil via a second adhesive, and the sealant film for an exterior material is laminated on the other surface of the metal foil via a first adhesive. The process of preparing the laminate and
A method for manufacturing an exterior material for a power storage device, which comprises an aging step of heat-treating the laminate to obtain an exterior material for the power storage device. The method for producing an exterior material for a power storage device according to claim 8, wherein the first adhesive is a thermosetting adhesive and the second adhesive is a thermosetting adhesive. In the range lubricant amount existing on the surface of the first non-oriented film layer forming the innermost layer of 0.1μg / cm ² ~1.0μg / cm ² of obtained by heating the storage device for exterior materials The method for manufacturing an exterior material for a power storage device according to any one of claims 6 to 9.

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