阅读说明：本技术 蓄电装置用封装材料 (Sealing material for electricity storage device ) 是由 村田光司 铃田昌由 于 2020-04-28 设计创作，主要内容包括：一种蓄电装置用封装材料,其中至少从外表面侧起依次具备基材保护层、基材层、粘接层、金属箔层、以及密封剂层,基材保护层是使混合有平均粒径不同的多种粒子的固化性树脂固化而构成的,固化性树脂是以多元醇成分作为主剂、以多异氰酸酯成分作为固化剂而构成的,在多种粒子当中,在将平均粒径较大的粒子作为大填料、将平均粒径较小的粒子作为小填料时,大填料的平均粒径为10μm以上,小填料的平均粒径为1μm以上,并且,大填料的混合量占基材保护层为3质量％以上,小填料的混合量占基材保护层为5质量％以上。(A sealing material for an electric storage device, comprising a base material protective layer, a base material layer, an adhesive layer, a metal foil layer, and a sealant layer in this order from at least the outer surface side, wherein the base material protective layer is formed by curing a curable resin in which a plurality of types of particles having different average particle diameters are mixed, the curable resin is formed by using a polyol component as a main component and a polyisocyanate component as a curing agent, and when particles having a larger average particle diameter among the plurality of types of particles are used as a large filler and particles having a smaller average particle diameter are used as a small filler, the average particle diameter of the large filler is 10 [ mu ] m or more, the average particle diameter of the small filler is 1 [ mu ] m or more, the amount of the large filler to be mixed is 3 mass% or more with respect to the base material protective layer, and the amount of the small filler to be mixed is 5 mass% or more with respect to the base material protective layer.)

1. A sealing material for an electric storage device, comprising a base material protective layer, a base material layer, an adhesive layer, a metal foil layer, and a sealant layer in this order from at least the outer surface side,

the substrate protective layer is formed by curing a curable resin in which a plurality of types of particles having different average particle diameters are mixed,

the curable resin is composed of a polyol component as a main component and a polyisocyanate component as a curing agent,

among the plurality of types of particles, when particles having a large average particle diameter are used as a large filler and particles having a small average particle diameter are used as a small filler,

the average particle diameter of the large filler is 10 [ mu ] m or more, the average particle diameter of the small filler is 1 [ mu ] m or more,

the amount of the large filler is 3 mass% or more of the base material protective layer, and the amount of the small filler is 5 mass% or more of the base material protective layer.

2. The encapsulating material for a power storage device according to claim 1, wherein,

the average particle diameter of the large filler is 30 [ mu ] m or less, the average particle diameter of the small filler is 5 [ mu ] m or less, and the amount of the large filler to be mixed is 25 mass% or less.

3. The encapsulating material for a power storage device according to claim 1 or 2, wherein,

at least a part of the polyisocyanate component is composed of an alicyclic polyisocyanate.

4. The encapsulating material for a power storage device according to any one of claims 1 to 3, wherein,

at least a part of the polyisocyanate component is composed of an aliphatic polyisocyanate or an aromatic polyisocyanate,

the amount of the large filler is 25 mass% or less, and the total amount of the large filler and the small filler is 50 mass% or less.

5. The electricity storage device sealing material according to any one of claims 1 to 4, wherein the large filler contains particles of an organic substance.

6. The encapsulating material for a power storage device according to claim 5, wherein,

the macrofiller contains particles of a thermoplastic organic substance, and the thickness of the base material protective layer is 10 [ mu ] m or less.

7. The electricity storage device sealing material according to any one of claims 1 to 6, wherein the large filler contains particles of an inorganic substance.

8. The electricity storage device sealing material according to any one of claims 1 to 7, wherein a coloring pigment is mixed in the adhesive layer.

Technical Field

The present invention relates to a packaging material for an electric storage device.

Background

As the power storage device, for example, a secondary battery such as a lithium ion battery, a nickel metal hydride battery, and a lead storage battery, and an electrochemical capacitor such as an electric double layer capacitor are known. In response to the size reduction of portable devices, the limitation of installation space, and the like, further size reduction of power storage devices is required, and lithium ion batteries with high energy density are attracting attention. As a sealing material for a lithium ion battery, a metal can has been used, but a film-like sealing material which is lightweight, has high heat dissipation, and can be produced at low cost has been used.

The film-like encapsulating material serves to prevent moisture from entering the inside of the lithium ion battery. Therefore, as the film-like sealing material, a film having a multilayer structure including a metal foil in a layer structure can be used. Then, the film-like sealing material is cold-formed to form a concave portion, the battery contents are accommodated in the concave portion, the remaining portion of the sealing material is folded, and the edge portion is heat-sealed, thereby forming the lithium ion battery (see patent document 1).

However, in order to prevent such a film-like sealing material having a multilayer structure from being contaminated in the production process thereof, the film-like sealing material is sometimes produced by attaching a light-adhesive protective film which is easily peeled off to the outside thereof. Among these, in a sealing material for a lithium ion battery having a matte outer surface, a base protective layer mixed with particles and having a matte outer surface is disposed on the outer surface, and when a battery electrolyte or the like is attached to the surface of the base protective layer, the appearance of the base protective layer may change.

The protective film is peeled and removed in the battery production process or after the battery production. Thus, when the light-adhesive protective film is peeled off and removed, the adhesive used for the protective film does not remain on the outer surface of the sealing material.

On the other hand, when the lithium ion battery manufactured as described above is used, it is bonded and fixed to an electrical device using a double-sided adhesive tape (PSA tape) having strong adhesiveness. Thus, the PSA tape must be firmly adhered to the outer surface of the potting material when adhesively securing it to the electrical device.

Documents of the prior art

Technical literature

Patent document 1: japanese patent laid-open publication No. 2013-101765

Disclosure of Invention

Problems to be solved by the invention

Therefore, in both the protective film and the PSA tape, one (protective film) needs to be peelable without leaving an adhesive on the outer surface of the sealing material, and the other (PSA tape) needs to be firmly bonded to the outer surface of the sealing material.

Accordingly, an object of the present invention is to provide a power storage device sealing material that can peel and remove the protective film used in the manufacturing process from the outer surface of the sealing material without leaving adhesive residue, and can firmly adhere a PSA tape to the outer surface of the thus exposed sealing material.

Means for solving the problems

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

[1] A sealing material for an electric storage device, comprising a base material protective layer, a base material layer, an adhesive layer, a metal foil layer, and a sealant layer in this order from at least the outer surface side, the substrate protective layer is formed by curing a curable resin in which a plurality of types of particles having different average particle diameters are mixed, the curable resin is composed of a polyol component as a main agent and a polyisocyanate component as a curing agent, among the plurality of types of particles, when particles having a large average particle diameter are used as a large filler and particles having a small average particle diameter are used as a small filler, the average particle diameter of the large filler is 10 [ mu ] m or more, the average particle diameter of the small filler is 1 [ mu ] m or more, and the mixing amount of the large filler accounts for more than 3 mass% of the base material protective layer, and the mixing amount of the small filler accounts for more than 5 mass% of the base material protective layer.

[2] The sealing material for an electricity storage device according to [1], wherein the large filler has an average particle diameter of 30 μm or less, the small filler has an average particle diameter of 5 μm or less, and the amount of the large filler to be mixed is 25 mass% or less.

[3] The electricity storage device sealing material according to item [1] or [2], wherein at least a part of the polyisocyanate component is composed of an alicyclic polyisocyanate.

[4] The electricity storage device sealing material according to any one of [1] to [3], wherein at least a part of the polyisocyanate component is composed of an aliphatic polyisocyanate or an aromatic polyisocyanate, the amount of the large filler is 25% by mass or less, and the total amount of the large filler and the small filler is 50% by mass or less.

[5] The electricity storage device sealing material according to any one of [1] to [4], wherein the large filler contains particles of an organic substance.

[6] The electricity storage device sealing material according to item [5], wherein the large filler contains thermoplastic organic particles, and the thickness of the base material protective layer is 10 μm or less.

[7] The electricity storage device sealing material according to any one of [1] to [6], wherein the large filler contains particles of an inorganic substance.

[8] The electricity storage device sealing material according to any one of [1] to [7], wherein a coloring pigment is mixed in the adhesive layer.

Effects of the invention

As is clear from the experimental examples described later, according to the invention described in the above [1], the light-adhesive protective film can be peeled and removed from the outer surface of the sealing material without leaving adhesive residue, and the PSA tape having strong adhesiveness can be firmly adhered to the outer surface of the sealing material.

In addition, according to the invention as recited in the above [2], since the outer surface can be formed into a uniform and dense matte shape, the outer appearance is free from a rough feeling, and a sealing material having an excellent outer appearance can be obtained.

Further, according to the invention as recited in the above item [3], the protective film having light adhesiveness can be peeled and removed from the outer surface of the sealing material without leaving adhesive residue, and the PSA tape having strong adhesiveness can be more firmly adhered to the outer surface of the sealing material.

Further, according to the invention as recited in the above item [4], the concave portion for accommodating the battery element can be formed by cold forming without causing cracks or peeling. From the viewpoint of more sufficiently obtaining such an effect, a part of the polyisocyanate component may be composed of an alicyclic polyisocyanate, and a part may be composed of an aliphatic polyisocyanate or an aromatic polyisocyanate.

Further, according to the invention as recited in the above [5], the thickness of the base material protective layer can be easily adjusted, and the thickness of the base material protective layer can be reduced while ensuring the peelability of the protective film and the adhesiveness of the PSA tape. By reducing the thickness of the base material protective layer, the process control in cold forming the electricity storage device sealing material can be easily performed. In this case, the above-mentioned effects can be more sufficiently obtained by setting the thickness of the base material protective layer within the range described in [6 ].

Further, according to the invention as recited in the above item [7], cold forming can be performed while maintaining a uniform and dense matte outer surface without causing change in the gloss of the outer surface due to cold forming.

Drawings

FIG. 1 is a schematic cross-sectional view of a specific example of a power storage device packaging material according to the present invention.

FIG. 2 is a view showing a cold-formed packaging material for an electric storage device according to the present invention, and FIG. 2(a) is a perspective view thereof; fig. 2(b) is a longitudinal sectional view taken along the line b-b in fig. 2 (a).

Fig. 3 is a perspective view showing a specific example of a method for manufacturing an electricity storage device according to the present invention, where fig. 3(a) is a perspective view showing a state where a packaging material for an electricity storage device is prepared, fig. 3(b) is a perspective view showing a state where a packaging material for an electricity storage device and a battery element are prepared, fig. 3(c) is a perspective view showing a state where a part of the packaging material for an electricity storage device is folded and an end portion is melted, and fig. 3(d) is a perspective view showing a state where both sides of the folded part are folded upward.

Detailed Description

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same or corresponding portions are denoted by the same reference numerals, and redundant description thereof is omitted.

[ encapsulating Material for Electrical storage device ]

Fig. 1 is a cross-sectional view schematically showing one embodiment of a power storage device packaging material according to the present invention. As shown in fig. 1, a sealing material (sealing material for an electric storage device) 10 of the present embodiment is formed by laminating a base material protective layer 12, a base material layer 11, a metal foil layer 14, and a sealant layer 17 in this order, and has corrosion prevention treated layers 15a and 15b on both surfaces of the metal foil layer 14. The base material layer 11 and the metal foil layer 14 are bonded together via the adhesive layer 13, and the metal foil layer 14 and the sealant layer 17 are bonded together via the sealant adhesive layer 16. In the sealing material 10, the base material protective layer 12 is used as the outer surface of the power storage device, and the sealant layer 17 is used as the inner surface of the power storage device. Hereinafter, each layer will be explained.

(substrate layer 11)

The base material layer 11 provides heat resistance in a sealing step in the production of the power storage device, and serves to suppress the occurrence of pinholes which may occur during molding or distribution. In addition, scratch resistance, chemical resistance, insulation, and the like may be provided.

The base material layer 11 is preferably a layer made of a resin film made of a resin having insulating properties. Examples of the resin film include stretched or unstretched films such as polyester films, polyamide films, and polypropylene films. The base layer 11 may be a single layer film composed of any one of these resin films, or may be a laminated film composed of 2 or more of these resin films.

Among these films, the base layer 11 is preferably a polyamide film, and more preferably a biaxially stretched polyamide film, from the viewpoint of excellent moldability. Examples of the polyamide resin for forming the polyamide film include nylon 6, a copolymer of nylon 6 and nylon 6, nylon 6,10, polymetaxylylene adipamide (MXD6), nylon 11, and nylon 12. Among these, nylon 6(ONy) is preferable from the viewpoint of excellent heat resistance, puncture strength, and impact strength.

(substrate protective layer 12)

The base material protection layer 12 is located on the outer surface of the electricity storage device sealing material 10, and has a function of protecting the base material layer 11, adhering to a light-adhesive protective film used in a battery manufacturing process, and easily peeling off and removing the protective film without leaving adhesive residue when peeling off and removing the protective film. The base material protective layer 12 also has a function of firmly bonding and fixing a strong-adhesive double-sided tape (PSA tape) when the power storage device packaging material 10 is bonded and fixed to an electrical apparatus.

In order to exhibit these effects, the substrate protective layer 12 needs to be formed by curing a curable resin in which a plurality of types of particles having different average particle diameters are mixed.

The curable resin contains a polyol component as a main component and a polyisocyanate component as a curing agent.

Although the polyol component may be any polyol, for example, a polyester polyol, an acrylic polyol, or a polyether polyol may be used. Mixtures of polyols are also possible. From the viewpoint of chemical resistance, adhesion to the base material layer 11, or coating film suitability, polyester polyol or acrylic polyol is preferably used.

As the polyisocyanate component, a single type of polyisocyanate may be used, or a plurality of types of polyisocyanates may be used in combination. In either case, the polyisocyanate component may contain an alicyclic polyisocyanate, or may contain an aliphatic polyisocyanate or an aromatic polyisocyanate, but preferably contains an alicyclic polyisocyanate. It is desirable that a part of the polyisocyanate component is composed of an alicyclic polyisocyanate and the remaining part is composed of an aliphatic polyisocyanate or an aromatic polyisocyanate, and these alicyclic polyisocyanate and aliphatic polyisocyanate or aromatic polyisocyanate are mixed to form the polyisocyanate component.

As is apparent from the experimental examples described below, when the polyisocyanate component contains an alicyclic polyisocyanate, the PSA tape having a strong adhesive property can be more firmly bonded and fixed when the electrical storage device packaging material 10 is bonded and fixed to an electrical apparatus than when the electrical storage device packaging material does not contain an alicyclic polyisocyanate. On the other hand, even when the PSA tape does not contain aliphatic polyisocyanate or aromatic polyisocyanate, the PSA tape can be firmly bonded and fixed, but cracks may occur when the electrical storage device sealing material 10 is cold-molded.

Examples of the alicyclic polyisocyanate include methylcyclohexane diisocyanate, isophorone diisocyanate, 4 '-dicyclohexylmethane diisocyanate, and isopropylidene dicyclohexyl-4, 4' -diisocyanate. Further, as the aliphatic polyisocyanate, for example, hexamethylene diisocyanate and the like can be used. As the aromatic polyisocyanate, m-xylylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, and the like can be used.

Next, among a plurality of types of the particles having different average particle diameters, particles having a larger average particle diameter are used as the large filler, and particles having a smaller average particle diameter are used as the small filler, and at this time, the large filler forms large irregularities on the surface of the substrate protective layer 12, so that the protective film having weak adhesiveness is adhered in point contact, and the adhesive used for the protective film can be easily peeled off and removed without remaining on the surface of the substrate protective layer 12. For this reason, it is necessary to set the average particle diameter of the large filler to 10 μm or more. When the average particle diameter of the large filler is smaller than this average particle diameter, the adhesive used for the protective film may remain on the surface of the base protective layer 12, that is, on the outer surface of the electricity storage device sealing material 10, when the protective film is peeled off and removed, and may inhibit the double-sided tape from being adhesively fixed.

The average particle diameter of the large filler is desirably 30 μm or less. When the average particle diameter of the large filler is larger than this average particle diameter, the surface appearance of the base material protective layer 12 does not become a uniform and dense matte state.

The amount of the large filler to be mixed needs to be 3 mass% or more based on the base material protective layer 12. When the amount of the large filler is less than the above amount, the adhesive used for the protective film may remain on the surface of the substrate protective layer 12 when the protective film is peeled off and removed.

In addition, the amount of the large filler to be mixed is desirably 25 mass% or less based on the base material protective layer 12. When the amount of the large filler to be mixed is more than this amount, the surface appearance of the base material protective layer 12 is not formed into a uniform and dense matte shape.

On the other hand, the small filler forms small irregularities on the surface of the base material protective layer 12, and the PSA tape can be firmly bonded and fixed. For this reason, it is necessary to set the average particle diameter of the small filler to 1 μm or more. When the average particle diameter of the small filler is smaller than this average particle diameter, the surface appearance of the base material protective layer 12 does not become a uniform and dense matte shape, and the PSA tape cannot be firmly adhered and fixed because of the small irregularities.

Further, it is desirable that the average particle diameter of the small filler is 5 μm or less. When the average particle diameter of the small filler is larger than this average particle diameter, the surface appearance of the base material protective layer 12 does not become a uniform and dense matte shape.

The amount of the small filler to be mixed needs to be 5 mass% or more of the base material protective layer 12. When the amount of the small filler is less than the above amount, the surface appearance of the base material protective layer 12 does not become uniform and dense matte, and the PSA tape cannot be firmly bonded and fixed because of the small unevenness.

In addition, the amount of the small filler to be mixed is desirably 45 mass% or less based on the base material protective layer 12. When the amount of the small filler is more than the mixing amount, the surface appearance of the substrate protective layer 12 does not become uniform and dense matte, and the substrate protective layer 12 becomes brittle and cracks may occur at the time of cold forming.

The total amount of these large fillers and small fillers is desirably 50 mass% or less. This is because if the total amount to be mixed is larger than this total amount, the base protective layer 12 becomes brittle, and cracks and the like are likely to occur in the base protective layer during cold forming. Further, the total amount to be mixed is desirably 8% by mass or more.

The material of such a large filler and a small filler may be arbitrary, and for example, organic particles (organic particles) or inorganic particles (inorganic particles) may be used. Examples of the organic particles include polyolefin particles such as polyethylene particles, acrylic particles, urethane particles, and polyester particles. As the inorganic particles, silica particles, alumina particles, barium sulfate particles, calcium carbonate particles, titanium oxide particles, and the like can be used.

Inorganic particles may be used as the large filler. When organic particles are used, the large filler may be crushed during cold molding, and a change in gloss may occur on the surface of the base protective layer 12, that is, the outer surface of the power storage device sealing material 10. In contrast, when the inorganic particles are used, the change in gloss on the outer surface of the electricity storage device packaging material 10 due to cold molding can be suppressed.

In addition, organic particles may be used as the large filler. When the organic particles are used, the organic particles are crushed when the electricity storage device sealing material 10 is produced in the lamination step, and the thickness of the base material protective layer 12 can be reduced. The use of thermoplastic organic particles among the organic particles makes it possible to easily control the thickness of the encapsulating material for an electricity storage device in the production of the article. As the thermoplastic organic particles, for example, polyolefin particles such as polyethylene particles can be used. By reducing the thickness of the base material protective layer 12, process control at the time of cold forming or the like can be easily performed. Even when the organic particles are crushed and the contact area with the protective film increases, the adhesion force between the organic particles (particularly polyethylene particles and the like) and the weakly adhesive protective film does not increase excessively, and the adhesive used for the protective film is not left on the surface of the base protective layer 12 and is easily peeled off and removed.

The base material protective layer 12 can be formed by dissolving or dispersing each component constituting it in a solvent to form a coating liquid, and applying the coating liquid on the base material layer 11.

For example, the coating liquid may be prepared by dissolving the polyol component in a solvent to prepare a varnish, mixing a large filler and a small filler with the varnish, and mixing the polyisocyanate component with the varnish. The coating liquid may be prepared by dissolving the polyol component in a solvent to prepare a varnish, dispersing a large filler and a small filler in a solvent to prepare a slurry, mixing the slurry with the varnish, and mixing the polyisocyanate component.

In addition to the above-mentioned coating liquid, additives such as a flame retardant, a slip agent, an antioxidant, a light stabilizer, a thickener, a leveling agent, a defoaming agent, a catalyst, and a reaction retarder may be mixed. Examples of the slip agent include fatty acid amides such as oleamide, erucamide, stearic acid amide, behenamide, ethylenebisoleamide, and ethylenebiserucamide. Further, as the reaction retarder, acetylacetone may be exemplified.

Further, as the coating method, a gravure direct coating method, a gravure reverse coating method, a micro-gravure coating method, or the like can be used.

The thickness of the substrate protective layer 12 may be 0.5 μm or more, 1.0 μm or more, or 1.5 μm or more, and may be 50 μm or less, 30 μm or less, 15 μm or less, or 10 μm or less. When the thickness is less than the lower limit value, the function of protecting the base material layer 11, the function of easily peeling and removing the protective film having light adhesiveness without leaving adhesive residue when peeling and removing the protective film having light adhesiveness, and the function of firmly bonding and fixing the PSA tape having strong adhesiveness cannot be obtained more sufficiently. When the thickness is equal to or less than the upper limit value, the entire thickness of the power storage device packaging material 10 can be reduced, and process management during cold forming of the power storage device packaging material 10 can be facilitated. In the case where the base protective layer 12 contains thermoplastic organic particles as a large filler, the organic particles are crushed in the lamination step in the production of the electrical storage device packaging material 10, and the thickness of the base protective layer 12 tends to be thin. Therefore, in the case where the large filler contains thermoplastic organic particles or consists only of thermoplastic organic particles, the thickness of the base material protective layer 12 may be 10 μm or less, 8 μm or less, or 6 μm or less.

(adhesive layer 13)

The adhesive layer 13 is a layer that bonds the base material layer 11 and the metal foil layer 14 together. The adhesive layer 13 has adhesion force necessary for firmly bonding the base material layer 11 and the metal foil layer 14 together, and also has followability for suppressing the metal foil layer 14 from being broken by the base material layer 11 at the time of cold forming (a function of reliably forming the adhesive layer 13 on the member without peeling even if the member is deformed or expanded).

As the adhesive constituting the adhesive layer 13, for example, a two-liquid curable polyurethane adhesive having a main agent composed of a polyol such as a polyester polyol, a polyether polyol, or an acrylic polyol, and a curing agent composed of an isocyanate such as an aromatic isocyanate or an aliphatic isocyanate can be used. In the adhesive, the molar ratio (═ NCO/OH) of the isocyanate group in the curing agent to the hydroxyl group in the main agent is preferably 1 to 50, and more preferably 2 to 30.

After the urethane adhesive is applied, for example, by aging at 40 ℃ or higher for 4 days or longer, the hydroxyl group of the main agent can be reacted with the isocyanate group of the curing agent, and the base layer 11 and the metal foil layer 14 can be bonded together more firmly.

The binder may be mixed with a coloring pigment. Such as black pigments. By mixing a coloring pigment with the adhesive to form the adhesive layer 13, the power storage device packaging material 10 is colored by the color, and the appearance of the power storage device using the power storage device packaging material 10 is also colored by the color, so that the design can be improved.

(Metal foil 14)

The metal foil layer 14 may be various metal foils such as aluminum and stainless steel, and the metal foil layer 14 is preferably an aluminum foil in view of workability such as moisture resistance and ductility and cost. The aluminum foil may be a general soft aluminum foil, but is preferably an iron-containing aluminum foil in view of excellent pinhole resistance and ductility during molding.

(anticorrosion-treated layers 15a and 15b)

The corrosion prevention treated layers 15a and 15b function to suppress corrosion of the metal foil layer 14 caused by the electrolytic solution or hydrofluoric acid generated by a reaction between the electrolytic solution and water. The corrosion-resistant treated layer 15a also functions to improve the adhesion between the metal foil layer 14 and the adhesive layer 13. The corrosion prevention treated layer 15b also functions to improve the adhesion between the metal foil layer 14 and the sealant adhesive layer 16. The corrosion-prevention treated layer 15a and the corrosion-prevention treated layer 15b may be layers having the same structure or layers having different structures.

The corrosion prevention treated layers 15a and 15b may be formed by subjecting the metal foil layer 14 to corrosion prevention treatment, which may be degreasing treatment, hydrothermal modification treatment, anodic oxidation treatment, chemical conversion treatment, or coating type corrosion prevention treatment in which a coating agent having corrosion prevention ability is applied; or a combination of these treatments.

(sealant adhesive layer 16)

The sealant adhesive layer 16 is a layer that bonds the metal foil layer 14 on which the corrosion prevention treated layer 15b is formed and the sealant layer 17. The sealant adhesive layer 16 may be formed of a dry lamination adhesive or a melt adhesive resin. In the sealant adhesive layer 16, a general adhesive for bonding the metal foil layer 14 and the sealant layer 17 together can be used. As a method of laminating the metal foil layer 14 and the sealant layer 17 via the sealant adhesive layer 16, for example, the following method can be used: dry lamination methods using dry lamination adhesives such as urethane adhesives; or an extrusion lamination process or a sandwich lamination process using the acid-modified polyolefin.

(sealant layer 17)

The sealant layer 17 is a layer that provides heat-sealing properties to the power storage device sealing material 10, and is disposed inside and heat-welded when the power storage device is assembled. The sealant layer 17 may be a resin film made of a polyolefin resin or an acid-modified polyolefin resin obtained by graft-modifying a polyolefin resin with an acid such as maleic anhydride. Among these, polyolefin resins which can improve the water vapor barrier property, do not excessively deform by heat sealing, and can constitute a form of an electric storage device are preferable, and polypropylene is particularly preferable.

(method for producing packaging Material for Electrical storage device 10)

Next, a method for manufacturing the power storage device packaging material 10 will be described. The manufacturing method is not limited to the following method.

Examples of the method for manufacturing the electricity storage device sealing material 10 include a method including steps S11 to S14 described below and manufacturing in the order of S11, S12, S13, and S14.

Step S11: and a step of forming an anticorrosion treated layer 15a on one surface of the metal foil layer 14 and forming an anticorrosion treated layer 15b on the other surface of the metal foil layer 14.

Step S12: and a step of bonding the surface of the corrosion-prevention treated layer 15a opposite to the metal foil layer 14 and the base material layer 11 together via the adhesive layer 13.

Step S13: and a step of applying and forming a substrate protective layer 12 on the surface of the substrate layer 11 opposite to the adhesive layer 13.

Step S14: and a step of forming a sealant layer 17 on the surface of the corrosion prevention treated layer 15b opposite to the metal foil layer 14 via a sealant adhesive layer 16.

[ method for producing an electric storage device ]

Next, a method for manufacturing a power storage device using the power storage device packaging material 10 will be described. Fig. 3(a) to (d) are perspective views showing the steps of manufacturing the one-side molded battery. Fig. 2 shows a cold-molded power storage device packaging material 10.

The secondary battery 20, which is a one-side molded battery, can be manufactured, for example, by the following steps S21 to S28. The secondary battery 20 manufactured through this step can be firmly bonded and fixed to an electrical device via a strongly adhesive double-sided tape (PSA tape).

Step S21: a step of preparing a packaging material 10 for an electricity storage device, a battery element 1 including an electrode, and a lead 2 extending from the electrode.

Step S22: a step of cold-forming the concave portion 10a for disposing the battery element 1 on one surface of the power storage device packaging material 10 (see fig. 3 a and 3 b).

Step S23: a step of disposing the battery element 1 in the concave portion 10a of the power storage device packaging material 10 in which the concave portion 10a is formed, folding the power storage device packaging material 10 so that the lid portion 10b covers the concave portion 10a, and pressure heat-welding one side of the power storage device packaging material 10 so as to sandwich the lead 2 extending from the battery element 1 (see fig. 3(b) and 3 (c)).

Step S24: and a step of attaching the protective film to the electrical storage device sealing material 10.

Step S25: and a step of holding the other side except the side holding the lead 2, performing pressure heat welding on the other side, injecting an electrolyte from the held side, and performing pressure heat welding on the held side in a vacuum state to manufacture the battery 20 (see fig. 3 (c)).

Step S26: and a step of charging and discharging the battery under predetermined conditions such as a current value, a voltage value, and an ambient temperature to cause a chemical change.

Step S27: and a step of peeling and removing the protective film from the power storage device packaging material 10.

Step S28: and a step of cutting the end of the pressure heat welding side except the side where the lead 2 is sandwiched, and bending the end toward the concave portion 10a (see fig. 3 (d)).

Examples

The present invention will be described below with reference to examples and comparative examples. For convenience of explanation, examples and comparative examples are not distinguished, and are referred to as experimental examples.

These experimental examples can be classified into experimental example 1 to experimental example 21. Therefore, each experimental example group is explained and examined, and then the examination of the experimental examples is finally conducted.

In each of these experimental examples, a nylon film was used as the base layer 11. Further, aluminum having a thickness of 35 μm and provided with the corrosion prevention treated layers 15a and 15b on both surfaces was used as the metal foil layer 14. In addition, a polypropylene film having a thickness of 35 μm was used as the sealant layer 17. The substrate protective layer 12 will be described later.

Then, first, the base material layer 11 and the metal foil layer 14 are bonded together with a heat-sensitive adhesive (step S12).

Next, the substrate protective layer 12 is formed on the surface of the substrate layer 11 by coating (step S13).

Next, the sealant adhesive layer 16 and the sealant layer 17 are formed on the metal foil layer 14 by a coextrusion method, whereby the electricity storage device sealing material 10 is manufactured (step S14).

Next, before describing the base material protective layer 12 of each experimental example, the evaluation method of these experimental examples will be explained. These experimental examples were evaluated from the following 4 viewpoints.

< evaluation method >

(appearance of coating film)

After the base material protective layer 12 was formed by coating (step S13), the appearance of the base material protective layer 12 was visually observed, and a uniform and dense matte appearance without a rough feeling was observed, and the result was evaluated as "a"; the case having a smooth appearance and a rough feeling was evaluated as "F".

(PSA sealing)

In the obtained sealing material, a double-sided tape having strong adhesiveness is attached to the sealant layer 17, and is attached to the metal plate via the double-sided tape. Next, a PSA tape having a width of 10mm was attached to the base material protective layer 12, and an aluminum foil was attached via the PSA tape. After being left at room temperature for 2 hours, the base material protective layer 12 and the PSA tape were peeled at 180 degrees at a speed of 300 mm/min using a tensile tester to measure the peel strength.

The peel strength was evaluated as "A" when it was 5N/10mm or more; the evaluation was "B" in the case of 2.5N/10mm or more and less than 5N/10 mm; a case of less than 2.5N/10mm was evaluated as "F".

(protective film paste residue)

A strong adhesive double-sided tape is attached to the sealant layer 17 of the obtained sealing material 10, and is attached to the metal plate via the double-sided tape. Next, a weakly adhesive protective film is attached to the base material protective layer 12. Then, the substrate was stored at a temperature of 85 ℃ for 6 hours, cooled to return to normal temperature, and then peeled off at 180 degrees at a speed of 300 mm/min by using a tensile tester between the substrate protective layer 12 and the protective film, and it was confirmed whether or not the adhesive of the protective film remained on the surface of the substrate protective layer 12. The case where no adhesive residue was observed was evaluated as "a"; the case where the residue was observed was evaluated as "F".

(appearance after Molding)

The concave portion 10a is cold-molded in the power storage device packaging material 10 (step S22 described above). The depth of the recess 10a is 3.5 mm. Then, whether or not cracks were generated and whether or not a change in gloss was generated in the base material protective layer 12 was evaluated by visual observation. The case where no cracks were generated and the gloss was maintained in the state before cold forming was evaluated as "A". The case where the gloss was changed without generating cracks and the glossy feeling (gloss increase) was partially generated was evaluated as "B". In addition, the case where cracks were generated in the base material protective layer 12 was evaluated as "F".

(film thickness)

The thickness of the substrate protective layer 12 in the obtained sealing material 10 was measured using a contact thickness measuring apparatus (trade name: ピーコック, manufactured by Kawasaki corporation). The difference between the thickness of the obtained sealing material 10 and the thickness of the sealing material sample on which the base material protection layer 12 was not formed was defined as the thickness of the base material protection layer 12.

< group of Experimental examples 1 and examination thereof >

The 1 st experimental example group consisted of experimental example 1-1 to experimental example 1-5. In this experimental example group, the main agent was polyester polyol, and the curing agent was Hexamethylene Diisocyanate (HDI) and isophorone diisocyanate (IPDI). HDI is an aliphatic polyisocyanate, and IPDI is an alicyclic polyisocyanate. Then, the mixing ratio of HDI to IPDI was 9:1 in terms of HDI to IPDI.

In addition, in this experimental example group, silica particles having an average particle diameter of 15 μm were used as a large filler, and were mixed by 10% by mass with respect to the base material protective layer 12.

In addition, in this experimental example group, silica particles were used as a small filler, and the silica particles were mixed by 20 mass% with respect to the base protective layer 12.

Then, in each experimental example, by using small fillers having different average particle diameters, the relationship between the average particle diameter of the small filler and each of the above-described evaluation items was investigated. The results are shown in Table 1.

[ Table 1]

(appearance of coating film)

From the results, it is understood that under the above conditions, when the average particle diameter of the small filler is 1 to 5 μm, a uniform and dense matte substrate protective layer having no rough feeling can be formed. In experimental examples 1 to 4, the average particle diameter of the small filler was smaller than the above average particle diameter, and therefore, the surface of the base protective layer had small irregularities and was not matte. In addition, in experimental examples 1 to 5, the surface of the base material protective layer was matte, but since the average particle diameter of the small filler was large, the unevenness was large, and uniform and dense matte was not formed.

(PSA sealing)

From the results, it is understood that under the above conditions, the PSA tape strongly adheres when the average particle size of the small filler is 1 μm or more.

(protective film paste residue)

It can be considered that: under the above conditions, the average particle diameter of the small filler is not related to the protective film paste residue, and no paste residue is generated regardless of the average particle diameter.

(appearance after Molding)

Therefore, the following steps are carried out: under the above conditions, the average particle diameter of the small filler is not related to the appearance after molding, and no crack is generated on the substrate protective layer and no change in gloss is caused regardless of the average particle diameter.

< group of Experimental examples 2 and examination thereof >

The group of experiment 2 was composed of experiment 2-1. In the group 2 of experimental examples, the relationship between the average particle size of the large filler and each of the above evaluation items was examined by using the large filler having a small average particle size and comparing it with the group 1 of experimental examples. That is, the electricity storage device sealing material 10 was produced in the same manner as in experimental example 1-2 except that the average particle diameter of the large filler used in experimental example 2-1 was 5 μm, and the above-described evaluation items were examined. The results are shown in Table 2.

[ Table 2]

(appearance of coating film)

From the results, it was found that the appearance of the coating film was not changed even when the average particle size of the large filler was set to 5 μm. That is, as in experimental example 1-2, a uniform and dense matte substrate protective layer having no rough feeling can be formed.

(PSA sealing)

It can be considered that: even if the average particle size of the large filler is set to 5 μm, the PSA tape is strongly adhered in the same manner as in experimental example 1-2.

(protective film paste residue)

When the large filler was made small and the average particle diameter was set to 5 μm, the adhesive of the protective film remained on the surface of the base protective layer 12, unlike in experimental example 1-2. Therefore, it can be considered that: the average particle size of the large filler is related to the protective film paste residue, and in order to prevent the paste residue from occurring under the above conditions, the average particle size of the large filler is set to 15 μm (experimental examples 1 to 3).

(appearance after Molding)

Therefore, the following steps are carried out: even when the average particle size of the large filler was set to 5 μm, no cracks were generated in the substrate protective layer and no change in gloss was caused, as in experimental example 1-2.

< group of Experimental examples 3 and examination thereof >

Since no protective film paste was generated in the 1 st experimental group in which the average particle size of the macrofiller was set to 15 μm, and a protective film paste was generated in the 2 nd experimental group in which the average particle size was set to 5 μm, the relationship between the average particle size of the macrofiller and each of the above-mentioned evaluation items was investigated in the 3 rd experimental group using macrofillers having average particle sizes therebetween. That is, the average particle diameter of the large filler used in this 3 rd experimental example group was 10 μm.

In addition, in each experimental example, the relationship between the average particle diameter of the small filler and each of the above evaluation items was investigated in the case of using the large filler having an average particle diameter of 10 μm by using the small fillers having different average particle diameters at the same time.

In contrast to this, in the group of experimental examples 1, in the case where the average particle size of the small filler was 0.1 μm (experimental examples 1 to 4) and 10 μm (experimental examples 1 to 5), the evaluation of the coating appearance and PSA adhesion was poor, and in the case where the average particle size of the small filler was 5 μm (experimental example 3-1), 3 μm (experimental example 3-2), and 1 μm (experimental example 3-3), the sealing material 10 for an electric storage device was manufactured, and the above evaluation items were examined. The results are shown in Table 3.

[ Table 3]

(appearance of coating film)

From the results, it was found that even when the average particle size of the large filler was set to 10 μm, the appearance of the coating film was not changed, and a uniform and dense matte substrate protective layer having no rough feeling was formed in the same manner as in experimental example 1. Furthermore, the average particle size of the small filler is irrelevant.

(PSA sealing)

It can be considered that: even if the average particle size of the large filler is 10 μm, the PSA tape is firmly adhered as in experimental example group 1. The average particle size of the small filler is irrelevant.

(protective film paste residue)

Even if the average particle size of the large filler is 10 μm, no paste residue is generated. The average particle size of the small filler is irrelevant.

In addition to the results of the 1 st experimental example group and the 2 nd experimental example group, the results of the 3 rd experimental example group were considered: in order to prevent the paste residue, the average particle diameter of the large filler may be 10 μm or more.

(appearance after Molding)

Therefore, the following steps are carried out: even when the average particle size of the large filler was set to 10 μm, no cracks were generated in the substrate protective layer and no change in gloss was caused, as in the experimental example group 1. The average particle size of the small filler is irrelevant.

< group of Experimental examples 4 and examination thereof >

In the group of experimental examples 4, the relationship between the average particle size of the large filler and each of the above evaluation items was investigated by increasing the average particle size of the large filler. That is, the average particle diameter of the large filler used in this group 4 of experimental examples was 30 μm.

In addition, in each experimental example, small fillers having different average particle diameters were used, and the relationship between the average particle diameter of the small filler and each of the above-mentioned evaluation items was examined in the case of using a large filler having an average particle diameter of 30 μm. The average particle diameters of the small fillers were 5 μm (Experimental example 4-1), 3 μm (Experimental example 4-2) and 1 μm (Experimental example 4-3), respectively.

The results of the above evaluation items are shown in table 4.

[ Table 4]

(appearance of coating film)

From the results, it was found that even when the average particle size of the large filler was 30 μm, the appearance of the coating film was not changed, and a uniform and dense matte substrate protective layer having no rough feeling was formed in the same manner as in experimental example 1. The average particle size of the small filler is irrelevant.

(PSA sealing)

It can be considered that: even if the average particle size of the large filler was 30 μm, the PSA tape was firmly adhered as in experimental example group 1. The average particle size of the small filler is irrelevant.

(protective film paste residue)

Even if the average particle size of the large filler is 30 μm, no paste residue is generated. The average particle size of the small filler is irrelevant.

(appearance after Molding)

Therefore, the following steps are carried out: even if the average particle size of the large filler was 30 μm, the substrate protective layer did not crack and did not cause change in gloss as in experimental example group 1. The average particle size of the small filler is irrelevant.

< group of Experimental examples 5 and examination thereof >

In experimental example group 5, the average particle size of the large filler was further increased, and the relationship between the average particle size of the large filler and each of the above-described evaluation items was examined. That is, the average particle diameter of the large filler used in this group 5 of experimental examples was 50 μm.

This group of 5 th experimental examples was composed of experimental example 5-1. That is, the power storage device sealing material 10 was produced in the same manner as in experimental example 1-2 except that the average particle diameter of the large filler used in experimental example 5-1 was 50 μm, and the above-described evaluation items were examined. The results are shown in Table 5.

[ Table 5]

(appearance of coating film)

From these results, it is found that when the average particle size of the large filler is 50 μm, a uniform and dense matte substrate protective layer having no rough feeling cannot be formed. That is, since the average particle diameter of the large filler is large, the surface of the base protective layer is matte with a rough feeling.

Therefore, it can be considered that: in order to form a uniform and dense matte base protective layer without a rough feeling, the average particle size of the small filler is set to 1 to 5 μm (see the examination of experimental example group 1), and the average particle size of the large filler is set to 30 μm or less.

(PSA sealing)

It can be considered that: even when the average particle size of the large filler was set to 50 μm, the PSA tape was firmly adhered as in experimental example 1-2.

(protective film paste residue)

Even when the average particle size of the large filler was 50 μm, no paste residue was generated as in experimental example 1-2.

(appearance after Molding)

Therefore, the following steps are carried out: even when the average particle size of the large filler was 50 μm, the substrate protective layer did not crack and did not cause change in gloss, as in experimental example 1-2.

< group of Experimental examples 6 and examination thereof >

In the group 6 of experimental examples, the relationship between the amount of the large filler and each of the above-described evaluation items was investigated by changing the amount of the large filler. That is, in experimental example 6, the power storage device sealing material 10 was produced in the same manner as in experimental example 1-2, except that the amount of the large filler to be mixed was 1 mass% (experimental example 6-1), 3 mass% (experimental example 6-2), 25 mass% (experimental example 6-3), and 30 mass% (experimental example 6-4) in the base protective layer, respectively, and the above-described evaluation items were examined. The results are shown in Table 6.

[ Table 6]

(appearance of coating film)

In experimental example 6-4, the surface of the base material protective layer was matte with a rough feel due to an excessive amount of the large filler. From this result, it can be considered that: the average particle size of the small filler is 1 to 5 μm, and the average particle size of the large filler is 30 μm or less (see the examination of experimental example groups 1 and 5), and the amount of the large filler to be mixed may be 25 mass% or less.

(PSA sealing)

It can be considered that: when the amount of the large filler is in the range of 1 to 30% by mass, the PSA tape is firmly adhered as in experimental example 1-2.

(protective film paste residue)

In experimental examples 6 to 4, the amount of the large filler mixed was too small, and the adhesive of the protective film remained on the surface of the base protective layer 12. From this result, it can be considered that: in order to prevent the adhesive of the protective film from remaining as paste, the average particle size of the large filler is set to 10 μm or more (see the examination of experimental example group 3), and the amount to be mixed may be set to 3 mass% or more.

(appearance after Molding)

It can be considered that: when the amount of the large filler is in the range of 1 to 30% by mass, the base material protective layer does not crack and does not cause a change in gloss, as in experimental example 1-2.

< group of Experimental examples 7 and examination thereof >

In the 7 th experimental example group, the relationship between the total amount of the large filler and the small filler and the above-mentioned evaluation items was investigated by setting the amount of the large filler to 30 mass% and changing the amount of the small filler.

In this experimental example group, the average particle size of the large filler was changed at the same time, but the average particle size was set to 10 μm and 15 μm, and it was found from the examination of the above experimental example groups 1 to 6 that the difference in the average particle size to such an extent did not affect the results of the respective evaluation items.

Further, experimental examples in which the relationship between the total amount of the large filler and each of the above evaluation items was investigated by changing the amount of the small filler while the amount of the large filler was set to less than 30% by mass are described later as experimental example groups 8 to 9.

That is, the average particle diameter of the large filler used in Experimental example 7-1 was 15 μm, the amount thereof was 30% by mass, and the amount of the small filler was 30% by mass. The total amount to be mixed is 60% by mass. Then, the power storage device sealing material 10 was produced in the same manner as in experimental example 1-2 except for this.

The average particle size of the large filler used in Experimental example 7-2 was 10 μm, the amount thereof was 20% by mass, and the amount thereof was 30% by mass. The total amount to be mixed is 50% by mass.

The results of the above evaluation items are shown in table 7.

[ Table 7]

(appearance of coating film)

Since the amount of the large filler to be mixed was too large, the surface of the base material protective layer was matte in a rough feel in both of experimental example 7-1 and experimental example 7-2. The experimental example group could not evaluate the relationship between the total amount of the components and the appearance of the coating film.

(PSA sealing)

It can be considered that: even when the total amount of the components is 50 to 60% by mass, the PSA tape is firmly adhered as in experimental example 1-2.

(protective film paste residue)

It can be considered that: even when the total amount of the components is 50 to 60% by mass, no adhesive residue of the protective film is generated as in the experimental example 1-2.

(appearance after Molding)

In experimental example 7-1 in which the amount of the small filler was 30 mass% and the total amount was 60 mass%, cracks were generated in the base material protective layer after cold forming. The reason for this is that the small filler is excessively mixed or the total amount of the small filler is excessively mixed, which is not clear from the 7 th experimental example group. However, by examining the experimental examples 8 to 9 described below together, it is found that the reason for the poor appearance after molding is mainly the total amount of blending.

< group of Experimental examples 8 and examination thereof >

In the 8 th experimental example group, the relationship between the total amount of the large filler and the small filler and the above-mentioned evaluation items was examined by changing the amount of the small filler by setting the average particle diameter of the large filler to 15 μm and the amount thereof to be mixed to 3% by mass. Then, the power storage device sealing material 10 was produced in the same manner as in experimental example 1-2 except for this.

The results of the above evaluation items are shown in table 8.

[ Table 8]

(appearance of coating film)

In experimental example 8-1, the amount of the small filler mixed was small (2 mass%) and the total amount mixed was small (5 mass%), and therefore the appearance of the base material protective layer 12 was smooth without being formed into a uniform and dense matte shape. In the experimental examples in which the amount of the small filler is 5 mass% or more and the total amount of the small filler is 8 mass% or more, the matte, uniform and dense matte state is not observed, and therefore it is considered that: in order to make the appearance of the base material protective layer 12 uniform and dense, matte, the amount of the small filler to be mixed may be 5 mass% or more and the total amount to be mixed may be 8 mass% or more. The reason why the appearance of the base protective layer 12 is smooth is the amount of the small filler mixed or the total amount of the small filler mixed, which is not clear in this experimental example group.

(PSA sealing)

Similarly, in experimental example 8-1, the PSA tape did not adhere strongly because the amount of the small filler was small (2 mass%) and the total amount of the small filler was small (5 mass%). In the experimental examples in which the amount of the small filler is 5% by mass or more and the total amount of the small filler is 8% by mass or more, the peel strength is high, and therefore it is considered that: in order to firmly adhere the PSA tape to the base protective layer 12, the average particle size of the small filler is set to 1 μm or more (see examination in experimental example group 1), and the amount to be mixed is preferably set to 5 mass% or more and the total amount to be mixed is preferably set to 8 mass% or more. The reason for this is not clear in this experimental example group, as to whether the mixing amount of the small filler is the total mixing amount.

(protective film paste residue)

It can be considered that: even if the total mixing amount is 2 to 53 mass%, no adhesive paste residue of the protective film is generated.

(appearance after Molding)

In examples 8 to 6 in which the amount of the small filler was 50 mass% and the total amount was 53 mass%, cracks were generated in the base material protective layer after cold forming. The reason for this is that the reason is that the mixing amount of the small filler is too large or the total mixing amount is too large, which is not clear in the 8 th experimental example group.

< group of Experimental examples 9 and examination thereof >

In the group of experimental examples 9, the relationship between the total amount of the large filler and the small filler and the above-mentioned evaluation items was examined by changing the amount of the small filler by setting the average particle diameter of the large filler to 15 μm and the amount thereof to be mixed to 25% by mass. Then, the power storage device sealing material 10 was produced in the same manner as in experimental example 1-2 except for this.

The results of the above evaluation items are shown in table 9.

[ Table 9]

(appearance of coating film)

In experimental example 9-1, since the amount of the small filler to be mixed is small (2 mass%), the appearance of the base protective layer 12 is not uniform and dense, but smooth. In addition, in this experimental example 9-1, since the total amount of the filler is 27 mass%, it can be estimated that the reason why the base material protective layer 12 becomes smooth is mainly the amount of the small filler by simultaneously examining the above 8 th experimental example group.

On the other hand, in the experimental example in which the amount of the small filler is 5 mass% or more, since the matte texture is uniform and dense without roughness, it is presumed that the amount of the small filler may be 5 mass% or more.

(PSA sealing)

Similarly, in experimental example 9-1, the PSA tape did not adhere strongly because the amount of the small filler was small (2 mass%). In addition, the reason for this is presumed to be mainly due to the amount of the small filler to be mixed.

In addition, since the experimental example in which the amount of the small filler is 5 mass% or more shows high peel strength, it is presumed that: in order to firmly adhere the PSA tape to the base material protective layer 12, the average particle size of the small filler is set to 1 μm or more (see examination in experimental example group 1), and the amount of the small filler to be mixed may be set to 5 mass% or more.

(protective film paste residue)

It can be considered that: even if the total mixing amount is 27 to 75 mass%, no adhesive paste residue of the protective film is generated. By considering the above 8 th experimental example group together, it can be considered that: the correlation between the total amount of mixing and the paste residue of the adhesive of the protective film is weak.

(appearance after Molding)

In examples 9 to 6 in which the amount of the small filler was 45 mass% and the total amount was 70 mass%, cracks were generated in the base material protective layer after cold forming. In the above-described experimental examples 8 to 5, although the blending amount of the small filler was 45 mass%, no crack was generated on the substrate protective layer and no change in gloss was caused, so that it is considered that the cause of the crack was the total blending amount.

In the experimental examples in which the total amount is 50% by mass or less, no cracks are generated and no change in gloss is caused, and therefore it is considered that: in order to obtain a good appearance after molding, the total amount of the large filler and the small filler may be 50% by mass or less.

< group of Experimental examples 10 and examination thereof >

In the 10 th experimental example group, the polyisocyanate component of the curable resin was changed, and the relationship between the type of the polyisocyanate component and each of the evaluation items was examined. Then, the power storage device sealing material 10 was produced in the same manner as in experimental example 1-1 except for this. In experimental example 10-1, the mixing ratio of Toluene Diisocyanate (TDI) to IPDI was TDI: IPDI was 9: 1.

The results of the above evaluation items are shown in table 10.

[ Table 10]

(appearance of coating film)

From the results, it is clear that the appearance of the coating film is not dependent on the type of polyisocyanate component.

(PSA sealing)

In experimental example 10-2 using only aliphatic polyisocyanate (HDI) as the polyisocyanate component and experimental example 10-4 using only aromatic polyisocyanate (TDI) as the polyisocyanate component, a decrease in peel strength of the PSA tape was observed. And does not adhere firmly. On the other hand, in experimental examples 10-1 and 10-3 in which an alicyclic polyisocyanate was used as at least a part of the polyisocyanate component (IPDI), since high peel strength was exhibited, it is considered that: in order to firmly adhere the PSA tape to the base material protective layer 12, it is important to use an alicyclic polyisocyanate for at least a part of the polyisocyanate component, except that the average particle size of the small filler is 1 μm or more and the amount of the small filler mixed is 5 mass% or more (see the examination in experimental example groups 1 and 9).

(protective film paste residue)

The paste residue of the adhesive of the protective film is not considered to depend on the type of the polyisocyanate component.

(appearance after Molding)

In Experimental example 10-3, in which only alicyclic polyisocyanate (IPDI) was used as the polyisocyanate component, cracks were generated in the substrate protective layer after cold forming. On the other hand, in experimental examples 1-1, 1-2, and 1-4 in which an aliphatic polyisocyanate (HDI) or an aromatic polyisocyanate (TDI) was used for at least a part of the polyisocyanate component, no crack was generated in the substrate protective layer, and no change in gloss was caused. Therefore, it can be seen that: in order to obtain a good appearance after molding, at least a part of the polyisocyanate component may be an aliphatic polyisocyanate or an aromatic polyisocyanate.

< group of Experimental examples 11 and examination thereof >

In experimental example group 11, the relationship between the material of the large filler and the material of the small filler and the above-described evaluation items was examined by changing the material of the large filler and the material of the small filler. Then, the power storage device sealing material 10 was produced in the same manner as in experimental example 1-1 except for this. In experimental example 11-1, organic particles (urethane particles) were used as the large filler and the small filler. In addition, in experimental example 11-2, inorganic particles (silica particles) were used as a large filler, and organic particles (urethane particles) were used as a small filler. In contrast, in experimental example 11-3, organic particles (urethane particles) were used as a large filler, and inorganic particles (silica particles) were used as a small filler.

The results of the above evaluation items are shown in table 11.

[ Table 11]

(appearance of coating film)

From the results, it is clear that the appearance of the coating film is not dependent on the material of the filler.

(PSA sealing)

The adhesive force of the PSA tape does not vary greatly depending on the material of the filler.

(protective film paste residue)

The adhesive residue of the protective film does not depend on the material of the filler.

(appearance after Molding)

In experimental examples 11-1 and 11-3 in which organic particles (urethane particles) were used as the large filler, the large filler was crushed at the time of cold forming, and gloss (glossy feeling) was generated on the base material protective layer 12. On the other hand, in experimental example 11-2 or the above experimental example group 1 in which inorganic particles (silica particles) were used as a large filler, such gloss (glossy feeling) was not generated.

Therefore, it can be considered that: in order to prevent the change in gloss due to cold forming, inorganic particles may be used as the large filler.

< experimental examples 12 to 21 and examination thereof >

In experimental examples 12 to 21, the polyol component of the curable resin was a polyacrylic polyol having a glass transition temperature of 50 to 60 ℃, and experimental examples 1 to 11 were repeated. The results of the above evaluation items are shown in tables 12 to 21.

[ Table 12]

[ Table 13]

[ Table 14]

[ Table 15]

[ Table 16]

[ Table 17]

[ Table 18]

[ Table 19]

[ Table 20]

[ Table 21]

The results of the above evaluation items were the same as those of experimental examples 1 to 11. Therefore, it can be considered that: no matter what evaluation item is, the evaluation item is not dependent on the kind of the polyol component.

< group of Experimental examples 22 and examination thereof >

In experimental example 22, Polyethylene (PE) particles, which are organic particles, were used as a large filler, and the relationship between the material, particle size, and amount of the large filler and the above-described evaluation items was examined by changing the particle size and amount. Then, the power storage device sealing material 10 was produced in the same manner as in experimental example 18-1 except for this.

The results of the above evaluation items are shown in table 22.

[ Table 22]

(appearance of coating film)

From these results, it was found that even when PE particles were used as the large filler, a uniform and dense matte substrate protective layer having no rough feeling could not be formed when the average particle diameter thereof was 50 μm. That is, since the average particle diameter of the large filler is large, the surface of the base protective layer is matte with a rough feeling.

(PSA sealing)

It can be considered that: the adhesive force of the PSA tape does not vary greatly depending on the material, particle size, and amount of the large filler.

(protective film paste residue)

In experimental example 22-6, the amount of the large filler mixed was too small, and therefore the adhesive of the protective film remained on the surface of the base protective layer 12. From the results, it is considered that the amount of PE particles to be mixed may be 3 mass% or more even when PE particles are used as the large filler in order to prevent the adhesive of the protective film from remaining as paste.

(appearance after Molding)

In experimental example 22-4, the amount of the large filler was 25% by mass, and the total amount of the large filler and the small filler was 55% by mass, which resulted in gloss (glossy feel) on the base material protective layer after cold molding.

(film thickness)

In experimental examples 1 to 21, the thickness of the substrate protective layer 12 was about the same as the particle size of the large filler, but in experimental example 22 using PE particles as the large filler, the thickness of the substrate protective layer 12 was significantly smaller than the particle size of the large filler. This is because the PE particles are deformed by heat in the lamination step when the electrical storage device sealing material 10 is produced. Even in this case, the PSA adhesion and the protective film paste residue were good except for experimental examples 22 to 6. In addition, the coating film appearance was good except for examples 22 to 7. Further, no crack was observed in the appearance after molding in any of the experimental examples.

< summary of investigation >

The above results can be summarized as follows.

(appearance of coating film)

In order to obtain a substrate protective layer having a uniform and dense matte appearance without a rough feeling, the following conditions 1-1 to 1-4 are satisfied.

Conditions 1 to 1: the average particle diameter of the small filler is set to 1 to 5 μm.

Conditions 1 to 2: the amount of the small filler is 5% by mass or more.

Conditions 1 to 3: the average particle diameter of the large filler is set to 30 μm or less.

Conditions 1 to 4: the amount of the large filler to be mixed is 25 mass% or less.

(PSA sealing)

When the PSA tape is adhered to the substrate protective layer, the following conditions 2-1 to 2-3 may be satisfied in order to firmly adhere the PSA tape to the substrate protective layer. In order to obtain a stronger adhesion, the condition 2 to 4 may be satisfied.

Condition 2-1: the average particle diameter of the small filler is set to 1 μm or more.

Conditions 2 to 2: the amount of the large filler to be mixed is 1 mass% or more.

Conditions 2 to 3: the amount of the small filler is 5% by mass or more.

Conditions 2 to 4: an alicyclic polyisocyanate is used as at least a part of the polyisocyanate component.

(protective film paste residue)

When the protective film is peeled off after being attached to the substrate protective layer, the following conditions 3-1 and 3-2 are satisfied in order to prevent the adhesive of the protective film from remaining on the surface of the substrate protective layer.

Condition 3-1: the average particle diameter of the large filler is set to 10 μm or more.

Condition 3-2: the amount of the large filler to be mixed is 3% by mass or more.

(appearance after Molding)

In order to prevent cracks from being generated in the base material protective layer when the electricity storage device packaging material is cold-formed, the following conditions 4-1 and 4-2 may be satisfied.

In this case, the condition 4-3 or the condition 4-4 may be satisfied in order to maintain the gloss in a state before cold forming.

Condition 4-1: the total amount of the large filler and the small filler is 50 mass% or less.

Condition 4-2: an aliphatic polyisocyanate or an aromatic polyisocyanate is used as at least a part of the polyisocyanate component.

Conditions 4 to 3: inorganic particles are used as the macrofiller.

Conditions 4 to 4: polyethylene particles are used as the macrofiller.

Description of the symbols

1 … battery element, 2 … lead, 10 … sealing material, 10a … concave portion, 10b … cover portion, 11 … base material layer, 12 … base material protective layer, 13 … adhesive layer, 14 … metal foil layer, 15a … anticorrosion treatment layer, 15b … anticorrosion treatment layer, 16 … adhesive layer, 17 … sealant layer, 20 … secondary battery.