JP6969227B2 - Battery case and battery - Google Patents

Description

The present invention relates to a battery case and a battery.

Conventionally, various types of batteries have been developed, but in all batteries, packaging materials are indispensable members for encapsulating battery elements such as electrodes and electrolytes. Conventionally, metal packaging materials have been widely used for battery packaging.

On the other hand, in recent years, with the improvement of high performance of electric vehicles, hybrid electric vehicles, personal computers, cameras, mobile phones, etc., batteries are required to have various shapes, and are required to be thinner and lighter. However, the metal packaging material, which has been widely used in the past, has a drawback that it is difficult to keep up with the diversification of shapes and there is a limit to weight reduction.

Therefore, in recent years, as a packaging material for batteries that can be easily processed into various shapes and can be made thinner and lighter, a film-like laminate in which a base material / barrier layer / heat-sealing resin layer is sequentially laminated. Has been proposed (see, for example, Patent Document 1).

Such battery packaging materials are broadly divided into molded type materials that are molded by a mold and used, and pouch type materials that are not molded by a mold. In the molding type battery packaging material, a packaging body in which recesses are formed in the sheet-shaped battery packaging material by molding with a mold, and battery elements such as electrodes and electrolytic solutions are arranged in the space formed by the recesses. However, by heat-sealing the heat-sealing resin layers at the peripheral edge of the recess, a battery in which the battery element is housed inside the package is manufactured.

On the other hand, the pouch-type packaging material is not molded by a mold, and is molded into a bag shape by bending a sheet-shaped battery packaging material such as a gusset bag (bag with a gusset). A pouch-type battery in which the battery element is housed inside the packaging material for the battery by forming a space for accommodating the battery element to form a package and heat-sealing the heat-sealing resin layers at the peripheral edges. Is manufactured (see, for example, Patent Document 2).

Japanese Unexamined Patent Publication No. 2008-287971 Japanese Unexamined Patent Publication No. 2000-251856

A pouch-type battery in which a battery element is housed in a pouch-type package has low mechanical strength and poor shape retention, and when mounted on a product, the pouch-type battery may be stored in a resin case. In many cases, it was difficult to achieve thinning and weight reduction of the product. Since the pouch-type battery may be subjected to strong vibration or impact during use or distribution process, it is desired to impart high mechanical strength and excellent shape retention.

Under such circumstances, it is a main object of the present invention to provide a battery case capable of imparting high mechanical strength and excellent shape retention to a pouch-type battery. Further, it is also an object of the present invention to provide a battery using the battery case.

The present inventor has made diligent studies to solve the above problems. As a result, the battery case includes a pouch-shaped package and a protective member that covers at least a part of the outer surface of the pouch-shaped package, and the thickness of the protective member is 0.1 mm or more and 1.0 mm or less. Found that it is possible to impart high mechanical strength and excellent shape retention to a pouch-type battery. The present invention has been completed by further studies based on these findings.

That is, the present invention provides the inventions of the following aspects.
Item 1. A pouch-shaped package and a protective member that covers at least a part of the outer surface of the pouch-shaped package.
It is a battery case equipped with
A battery case having a protective member having a thickness of 0.1 mm or more and 1.0 mm or less.
Item 2. Item 2. The battery case according to Item 1, wherein the protective member is made of a resin.
Item 3. Item 2. The battery case according to Item 1 or 2, wherein the pouch-type package has a side surface portion, and the protective member covers at least the side surface portion of the outer surface of the pouch-type package.
Item 4. Item 1. The battery case described.
Item 5. The pouch-type package is composed of a laminate having at least a barrier layer and a heat-sealing resin layer.
Item 2. The battery case according to any one of Items 1 to 4, wherein the ratio of the thickness of the heat-sealing resin layer to the thickness of the laminate is 20% or more.
Item 6. Item 5. The battery case according to Item 5, wherein the barrier layer has a thickness of 10 μm or more and 40 μm or less.
Item 7. Item 2. The battery case according to any one of Items 5 or 6, wherein the pouch-shaped package is provided with a protective layer on the side of the barrier layer opposite to the heat-sealing resin layer side.
Item 8. A battery in which a battery element including at least a positive electrode, a negative electrode, and an electrolyte is housed in the pouch-shaped package of the battery case according to any one of Items 1 to 7.

According to the present invention, it is possible to provide a battery case that imparts high mechanical strength and excellent shape retention to a pouch-type battery. Further, the present invention can also provide a battery using the battery case.

It is an example of a schematic diagram for explaining the structure of a pouch type package. It is an example of a schematic diagram for explaining the structure of a pouch type package. It is an example of a schematic diagram for explaining the structure of a pouch type package. It is a schematic diagram which shows an example of the cross-sectional structure of a pouch type package. It is a schematic diagram which shows an example of the cross-sectional structure of a pouch type package. It is a schematic diagram which shows an example of the cross-sectional structure of a pouch type package. It is a schematic diagram which shows how the case for a battery of this invention is obtained by covering the side surface and the bottom surface of the outer surface of a pouch type package with a protective member. It is a schematic diagram of an example of the battery case of this invention.

The battery case of the present invention is a battery case including a pouch-type package and a protective member that covers at least a part of the outer surface of the pouch-type package. The battery case is characterized in that the thickness of the protective member is in the range of 0.1 mm or more and 1.0 mm or less. Hereinafter, the battery case of the present invention will be described in detail.

In this specification, the numerical range indicated by "~" means "greater than or equal to" and "less than or equal to". For example, the notation of 2 to 15 mm means 2 mm or more and 15 mm or less.

Structure of Protective Member In the battery case 20 of the present invention, the protective member 12 covers at least a part of the outer surface of the pouch-shaped package 11. In the battery case 20 of the present invention, since at least a part of the outer surface of the pouch-type package 11 is covered with the protective member 12, the pouch-type battery is imparted with high mechanical strength and excellent shape retention. NS. Further, by imparting excellent shape retention, it becomes easy to align the pouch type battery when assembling or modularizing it. Further, by imparting excellent shape retention, vibration of the pouch-type package can be suppressed, and pinholes can be suppressed from occurring at the bent portion of the pouch-type package.

FIG. 7 shows a state in which the side surface portion 11a and the bottom surface portion 11b of the outer surface of the pouch-shaped package 11 are covered with the protective member 12 to obtain the battery case 20 of the present invention, and FIG. 8 shows the obtained case 20. A schematic diagram of the battery case 20 is shown. In FIGS. 7 and 8, the protective member 12 constitutes a rectangular container having four side surface portions 12a and a bottom surface portion 12b, and the pouch-shaped package 11 is formed from the open upper surface of the protective member 12. By accommodating the pouch-shaped package 11, a battery case 20 in which the side surface portions 11a and the bottom surface portion 11b are covered with the protective member 12 is obtained.

From the viewpoint of imparting high mechanical strength and excellent shape retention to the pouch-type battery, in the battery case 20 of the present invention, the protective member 12 covers at least the side surface portion 11a of the outer surface of the pouch-type package 11. It is preferable, and it is more preferable to cover at least the side surface portion 11a and the bottom surface portion 11b of the outer surface of the pouch type package 11. Further, the entire outer surface of the pouch-shaped package 11 may be covered with the protective member 12.

The method of covering at least a part of the outer surface of the pouch-type package 11 with the protective member 12 is not particularly limited, and the protective member 12 is attached to the outer surface of the pouch-type package 11 using an adhesive member such as tape or an adhesive. Examples thereof include a method of attaching the pouch-shaped package 11 and a method of accommodating the pouch-shaped package 11 in the container-shaped protective member 12 (see, for example, FIGS. 7 and 8). The protective member 12 is preferably adhered to at least a part of the outer surface of the pouch-shaped package 11.

The material constituting the protective member 12 is not particularly limited, but a resin may be mentioned because it is lightweight and has high strength. The resin is not particularly limited, and is, for example, polyolefin, polyester, polyamide, polyvinyl resin, epoxy resin, acrylic resin, fluororesin, polyurethane, silicon resin, phenol resin, polyetherimide, polyimide, polycarbonate, and a mixture thereof. And copolymers. Examples of the material constituting the protective member 12 include polyolefins such as polyethylene, polypropylene, polystyrene and polyvinyl chloride; and polyesters such as polyethylene terephthalate.

The battery case 20 of the present invention is characterized in that the thickness of the protective member 12 is in the range of 0.1 mm or more and 1.0 mm or less. When the thickness is 0.1 mm or more, the shape retention and mechanical strength of the pouch type battery can be suitably improved. Further, the thickness of 1.0 mm or less contributes to the thinning of the pouch-type battery, the pouch-type battery can be accommodated in the application, and the battery capacity can be improved. As the thickness of the protective member, the lower limit is preferably about 0.15 mm or more, more preferably about 0.20 mm or more, further preferably about 0.30 mm or more, and the upper limit is preferably about 0.80 mm or less. More preferably, it is 0.60 mm or less, and further preferably 0.50 mm or less. The preferred range of the thickness of the protective member is about 0.10 to 0.80 mm, about 0.10 to 0.60 mm, about 0.10 to 0.50 mm, about 0.15 to 0.80 mm, and 0. About 15 to 0.60 mm, about 0.15 to 0.50 mm, about 0.25 to 0.80 mm, about 0.25 to 0.60 mm, about 0.25 to 0.50 mm, about 0.30 to 0.80 mm The degree, about 0.30 to 0.60 mm, about 0.30 to 0.50 mm can be mentioned.

Structure of Package For example, as shown in the schematic diagram of FIG. 8, the battery case 20 of the present invention comprises a pouch-type package 11 and a protective member 12 that covers at least a part of the outer surface of the pouch-type package 11. I have. The battery element is sealed by the pouch-type package 11 to maintain the sealing property.

The pouch-type package 11 used for the battery case will be described with reference to an example of FIGS. 1 to 3. For example, as shown in the schematic diagram of FIG. 1, when three packaging materials 10a, 10b, and 10c are heat-sealed to produce a pouch-shaped package 11 as shown in the schematic diagram of FIG. 2, 3 The peripheral edges of each of the packaging materials 10a, 10b, and 10c are heat-sealed to form a space for accommodating the battery element. The schematic views of FIGS. 1 to 3 show how three packaging materials 10a, 10b, and 10c (packaging materials 10) are combined to form a pouch-shaped package 11 in the shape of a gusset bag.

In the pouch-type package 11 provided in the battery case of the present invention, the ratio of the thickness of the heat-sealing resin layer 2 to the thickness (total thickness) of the laminate constituting the pouch-type package 11 is as follows. The lower limit is preferably 20% or more, more preferably about 30% or more, still more preferably about 40% or more, and the upper limit is preferably about 80% or less, more preferably about 70% or less, still more preferably about. 60% or less can be mentioned. The preferred range of the ratio is about 20 to 80%, about 20 to 70%, about 20 to 60%, about 30 to 80%, about 30 to 70%, about 30 to 60%, and 40 to 80%. The degree is about 40 to 70% and about 40 to 60%.

In a pouch-type package used for a pouch-type battery, a space for accommodating a battery element is formed by bending the packaging material, so that the bent portion needs to be heat-sealed, and the sealing property tends to deteriorate. Has the problem. For example, in the case of the gusset bag-shaped package 11 shown in FIGS. 2 and 3, the x of the packaging materials 10a and 10b is particularly provided in the peripheral portion of the portion P in which the three packaging materials 10a, 10b and 10c are bent and in contact with each other. When heat-sealing each packaging material at both ends in the direction and both ends in the x direction of the packaging material 10c using a heated metal plate or the like, there are three bottom gussets and the top of the bottom gussets. Since there are two sheets and a step is generated, there is a problem that the sealing of the packaging material by heat fusion tends to be incomplete at the peripheral heat bonding portion of the bottom gusset portion.

On the other hand, in the pouch-type package 11 provided in the battery case of the present invention, the thickness of the heat-sealing resin layer 2 in the thickness (total thickness) of the laminate constituting the pouch-type package 11 When the ratio of the above values is satisfied, the heat fusion is preferably performed at the bent portion, the step portion, etc. at the time of heat fusion of the pouch type package 11, and as a result, the sealing property is also suitable. Be enhanced.

The pouch-type package 11 may have a shape used for a pouch-type battery, and the shape is not limited to the example shown in the schematic views of FIGS. 1 to 3, for example, a three-way seal bag. , Four-sided seal bag, standing pouch, pillow bag, pillow bag set bag, four-pillar pillow set bag, modified four-pillar pillow set bag, square bottom bag, half-fold bottom gusset bag, half-fold bag, etc.

The pouch-type package 11 is used for sealing and accommodating battery elements such as a positive electrode, a negative electrode, and an electrolyte. That is, the battery element of the present invention in which at least a part of the outer surface of the pouch-type package 11 is covered with the protective member 12 accommodates a battery element having at least a positive electrode, a negative electrode, and an electrolyte to form a pouch-type battery. can do.

Specifically, a battery element having at least a positive electrode, a negative electrode, and an electrolyte is housed inside the pouch-type package 11, and metal terminals connected to each of the positive electrode and the negative electrode are placed outside the pouch-type package 11. A heat-sealing portion (a region where the heat-sealing resin layers are in contact with each other) is coated on the peripheral edge of the battery element so as to be formed, and the heat-sealing resin layer of the heat-sealing portion is covered. By heat-sealing and sealing each other, a battery using a battery case is provided. When the battery element is housed in the pouch-shaped package formed by the battery case of the present invention, the heat-sealing resin portion of the battery case of the present invention is set to be inside (the surface in contact with the battery element). To form a pouch-shaped package.

The battery case of the present invention may be used for either a primary battery or a secondary battery, but is preferably a secondary battery. The type of the secondary battery to which the battery case of the present invention is applied is not particularly limited, and for example, a lithium ion battery, a lithium ion polymer battery, a lead storage battery, a nickel / hydrogen storage battery, a nickel / cadmium storage battery, and a nickel / iron. Examples include storage batteries, nickel / zinc storage batteries, silver oxide / zinc storage batteries, metal air batteries, polyvalent cation batteries, capacitors, and capacitors. Among these secondary batteries, a lithium ion battery and a lithium ion polymer battery can be mentioned as suitable application targets of the battery case of the present invention.

The pouch-type package 11 (packaging material 10 constituting the pouch-type package 11) is a laminated body including at least a barrier layer 1 and a heat-sealing resin layer 2, as shown in FIGS. 4 to 6, for example. Consists of. In the pouch-type package 11, the heat-sealing resin layer 2 is the innermost layer. That is, at the time of assembling the battery, the heat-sealing resin layers 2 located on the peripheral edge of the battery element are heat-sealed to seal the battery element, whereby the battery element is sealed.

As shown in FIGS. 5 and 6, the pouch-type package 11 has a protective layer 3 as necessary for the purpose of improving designability, electrolytic solution resistance, scratch resistance, moldability, shape retention, and the like. May have. When the pouch-type package 11 has the protective layer 3, the pouch-shaped package 11 has a laminated structure including the protective layer 3, the barrier layer 1, and the heat-sealing resin layer 2 in this order. The protective layer 3 may constitute the outer surface of the pouch-shaped package 11.

Further, in the battery case of the present invention, as shown in FIG. 6, an adhesive layer 4 is provided between the protective layer 3 and the barrier layer 1 as necessary for the purpose of enhancing the adhesiveness between the protective layer 3 and the barrier layer 1. May be. Further, as shown in FIG. 6, an adhesive layer 5 may be provided between the barrier layer 1 and the heat-bondable resin layer 2 for the purpose of enhancing their adhesiveness, if necessary.

The thickness of the laminate constituting the pouch-type package 11 is not particularly limited, but from the viewpoint of reducing the thickness of the pouch-type package 11 to increase the energy density of the battery, the upper limit is, for example, about 250 μm or less. It is preferably about 200 μm or less, more preferably about 180 μm or less, still more preferably about 150 μm or less, and the lower limit is, for example, about 60 μm or more. The range of the thickness of the laminated body is preferably about 60 to 250 μm, about 60 to 200 μm, about 60 to 180 μm, and about 60 to 150 μm.

Each layer forming the pouch-shaped package 11 [barrier layer 1]
In the pouch-type package 11, the barrier layer 1 is a layer having a function of improving the strength of the pouch-type package 11 and preventing water vapor, oxygen, light, and the like from entering the inside of the battery. The barrier layer 1 can be formed of a metal foil, a metal vapor deposition film, an inorganic oxide vapor deposition film, a carbon-containing inorganic oxide vapor deposition film, a film provided with these vapor deposition films, or the like, and is formed of a metal foil. Is preferable. Specific examples of the metal constituting the barrier layer 1 include aluminum, stainless steel, titanium and the like, and preferably aluminum or stainless steel.

Since the pouch-shaped package 11 does not have a recess formed by a mold in the battery manufacturing process, hard aluminum, stainless steel, or the like can be used as the material constituting the barrier layer 1. Hard aluminum and stainless steel have the advantage of excellent mechanical strength.

Preferred aluminum constituting the barrier layer 1 includes, for example, "JIS H4160: 1994 1N30", "JIS H4160: 1994 3003", "JIS H4160: 1994 A3004HO", "JIS H4160: 1994 3004", "JIS H4160". : 1994 8021 ”,“ JIS H4160: 1994 A8021H-O ”,“ JIS H4160: 1994 8079 ”,“ JIS H4160: 1994 A8079H-O ”, etc. Those having a composition such as "A3004H-H18" and "JIS H4160: 1994 A8021H-H18" are preferable. Examples of stainless steel include SUS304 and SUS403.

The thickness of the barrier layer 1 is not particularly limited, but is preferably about 10 to 50 μm, and more preferably about 10 to 45 μm.

Further, it is preferable that at least one surface, preferably both sides, of the barrier layer 1 is subjected to chemical conversion treatment in order to stabilize adhesion, prevent dissolution and corrosion, and the like. Here, the chemical conversion treatment refers to a treatment for forming an acid-resistant film on the surface of the barrier layer. As the chemical conversion treatment, for example, chromate treatment using a chromium compound such as chromium nitrate, chromium fluoride, chromium sulfate, chromium acetate, chromium oxalate, chromium bicarbonate, acetylacetate chromate, chromium chloride, potassium sulfate chromium; phosphorus. Phosphoric acid treatment with a phosphoric acid compound such as sodium acid, potassium phosphate, ammonium phosphate, polyphosphoric acid; for an aminoated phenol polymer having repeating units represented by the following general formulas (1) to (4). For example, the chemical conversion process that was used. Among the chromium compounds, a chromic acid compound is preferable. In the amination phenol polymer, the repeating unit represented by the following general formulas (1) to (4) may be contained alone or in any combination of two or more. May be good.

In the general formulas (1) to (4), X represents a hydrogen atom, a hydroxyl group, an alkyl group, a hydroxyalkyl group, an allyl group or a benzyl group. Further, R ¹ and R ² are the same or different, respectively, and represent a hydroxyl group, an alkyl group, or a hydroxyalkyl group. In the general formulas (1) to (4) ^{, examples of the alkyl group represented by X, R 1} and R ² include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group and an isobutyl group. Examples thereof include a linear or branched alkyl group having 1 to 4 carbon atoms such as a tert-butyl group. The hydroxyalkyl groups represented by X, R ¹ and R ² include, for example, hydroxymethyl group, 1-hydroxyethyl group, 2-hydroxyethyl group, 1-hydroxypropyl group, 2-hydroxypropyl group and 3-. A linear or branched chain having 1 to 4 carbon atoms in which one hydroxyl group such as a hydroxypropyl group, a 1-hydroxybutyl group, a 2-hydroxybutyl group, a 3-hydroxybutyl group, or a 4-hydroxybutyl group is substituted. Alkyl groups can be mentioned. In the general formulas (1) to (4), the ^{alkyl group and the hydroxyalkyl group represented by X, R 1} and R ² may be the same or different from each other. In the general formulas (1) to (4), X is preferably a hydrogen atom, a hydroxyl group or a hydroxyalkyl group. The number average molecular weight of the aminoated phenol polymer having the repeating unit represented by the general formulas (1) to (4) is, for example, preferably 5 to 1 million, more preferably 1000 to 20,000. ..

Further, as a chemical conversion treatment method for imparting corrosion resistance to the barrier layer 1, a material in which metal oxides such as aluminum oxide, titanium oxide, cerium oxide and tin oxide and fine particles of barium sulfate are dispersed in phosphoric acid is coated. A method of forming a corrosion resistant layer on the surface of the barrier layer 1 by performing a baking treatment at 150 ° C. or higher can be mentioned. Further, a resin layer obtained by cross-linking a cationic polymer with a cross-linking agent may be further formed on the corrosion resistant layer. Here, examples of the cationic polymer include polyethyleneimine, an ionic polymer complex composed of polyethyleneimine and a polymer having a carboxylic acid, a primary amine graft acrylic resin obtained by graft-polymerizing a primary amine on an acrylic main skeleton, and polyallylamine. Alternatively, a derivative thereof, aminophenol and the like can be mentioned. As these cationic polymers, only one kind may be used, or two or more kinds may be used in combination. Examples of the cross-linking agent include a compound having at least one functional group selected from the group consisting of an isocyanate group, a glycidyl group, a carboxyl group, and an oxazoline group, a silane coupling agent, and the like. As these cross-linking agents, only one kind may be used, or two or more kinds may be used in combination.

As the chemical conversion treatment, only one type of chemical conversion treatment may be performed, or two or more types of chemical conversion treatment may be performed in combination. Further, these chemical conversion treatments may be carried out by using one kind of compound alone or by using two or more kinds of compounds in combination. Among the chemical conversion treatments, chromate treatment and chemical conversion treatment in which a chromium compound, a phosphoric acid compound, and an amination phenol polymer are combined are preferable.

The amount of the acid-resistant film formed on the surface of the barrier layer 1 in the chemical conversion treatment is not particularly limited, but for example, in the case of performing the above chromate treatment, the chromic acid compound is contained per ^{1 m 2 of the surface of the barrier layer 1.} Chromate equivalent is about 0.5 to 50 mg, preferably about 1.0 to 40 mg, phosphorus compound is about 0.5 to 50 mg, preferably about 1.0 to 40 mg, and amination phenol polymer is about 1 to 1. It is desirable that the content is about 200 mg, preferably about 5.0 to 150 mg.

In the chemical conversion treatment, a solution containing a compound used for forming an acid-resistant film is applied to the surface of the barrier layer by a bar coating method, a roll coating method, a gravure coating method, a dipping method, or the like, and then the temperature of the barrier layer is 70. This is done by heating to ~ 200 ° C. Further, before the chemical conversion treatment is applied to the barrier layer, the barrier layer may be subjected to a degreasing treatment by an alkaline dipping method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method or the like in advance. By performing the degreasing treatment in this way, it becomes possible to more efficiently perform the chemical conversion treatment on the surface of the barrier layer.

[Heat-fused resin layer 2]
In the pouch-type package 11, the heat-sealing resin layer 2 corresponds to the innermost layer, and is a layer in which the heat-sealing resin layers are heat-sealed to seal the battery element when the battery is assembled.

The resin component used in the heat-fusing resin layer 2 is not particularly limited as long as it can be heat-fused, and examples thereof include polyolefins, cyclic polyolefins, acid-modified polyolefins, and acid-modified cyclic polyolefins. That is, the resin constituting the heat-sealing resin layer 2 may or may not contain a polyolefin skeleton, and preferably contains a polyolefin skeleton. The fact that the resin constituting the heat-sealing resin layer 2 contains a polyolefin skeleton can be analyzed by, for example, infrared spectroscopy, gas chromatography-mass spectrometry, or the like, and the analysis method is not particularly limited. For example, when measuring the infrared spectroscopy at a maleic anhydride-modified polyolefin, a peak derived from maleic acid is detected in the vicinity of the wave number of 1760 cm ^-1 and near the wave number 1780 cm ^-1. However, if the degree of acid denaturation is low, the peak may become small and may not be detected. In that case, it can be analyzed by nuclear magnetic resonance spectroscopy.

Specific examples of the polyolefin include polyethylene such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene; homopolypropylene, a block copolymer of polypropylene (for example, a block copolymer of propylene and ethylene), and polypropylene. Polypropylene such as random copolymers of polyethylene (eg, random copolymers of propylene and ethylene); polyethylene-butene-propylene tarpolymers and the like. Among these polyolefins, polyethylene and polypropylene are preferable.

The cyclic polyolefin is a copolymer of an olefin and a cyclic monomer, and examples of the olefin which is a constituent monomer of the cyclic polyolefin include ethylene, propylene, 4-methyl-1-pentene, butadiene, and isoprene. .. Examples of the cyclic monomer which is a constituent monomer of the cyclic polyolefin include cyclic alkenes such as norbornene; specifically, cyclic diene such as cyclopentadiene, dicyclopentadiene, cyclohexadiene, and norbornadiene. Among these polyolefins, cyclic alkene is preferable, and norbornene is more preferable.

The acid-modified polyolefin is a polymer modified by block-polymerizing or graft-polymerizing the polyolefin with an acid component such as a carboxylic acid. Examples of the acid component used for the modification include carboxylic acids such as maleic acid, acrylic acid, itaconic acid, crotonic acid, maleic anhydride and itaconic anhydride, or anhydrides thereof.

The acid-modified cyclic polyolefin means that a part of the monomer constituting the cyclic polyolefin is copolymerized in place of α, β-unsaturated carboxylic acid or its anhydride, or α, β-with respect to the cyclic polyolefin. It is a polymer obtained by block polymerization or graft polymerization of unsaturated carboxylic acid or its anhydride. The same applies to the cyclic polyolefin that is modified with carboxylic acid. The carboxylic acid used for the modification is the same as that used for the modification of the polyolefin.

Among these resin components, polyolefins such as polypropylene and carboxylic acid-modified polyolefins are preferable; and polypropylene and acid-modified polypropylene are more preferable.

The heat-bondable resin layer 2 may be formed of one type of resin component alone, or may be formed of a blended polymer in which two or more types of resin components are combined. Further, the heat-sealing resin layer 2 may be formed of only one layer, or may be formed of two or more layers with the same or different resin components.

The melt mass flow rate (MFR) of the resin constituting the heat-sealing resin layer 2 is not particularly limited, but has excellent bending resistance and high mechanical properties while further effectively improving the sealing performance of the battery case. From the viewpoint of exerting the strength, preferably about 5 to 30 g / 10 minutes, more preferably about 7 to 25 g / 10 minutes, still more preferably about 10 to 15 g / 10 minutes. When the MFR is in such a range, the flow of the resin is appropriate, the step seal portion is easily filled when the pouch is formed, and excellent sealing property is easily obtained. The melt mass flow rate (MFR) is a value measured using a melt indexer at a measurement temperature of 230 ° C. and a weight of 2.16 kg by a method according to JIS K7210: 2014.

In the present invention, from the viewpoint of enhancing the line suitability of the packaging material constituting the pouch-type packaging body, it is preferable that the lubricant adheres to the surface of the heat-sealing resin layer. The lubricant is not particularly limited, but an amide-based lubricant is preferable.

Specific examples of the amide-based lubricant include saturated fatty acid amides, unsaturated fatty acid amides, substituted amides, methylol amides, saturated fatty acid bisamides, and unsaturated fatty acid bisamides. Specific examples of the saturated fatty acid amide include lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, hydroxystearic acid amide and the like. Specific examples of unsaturated fatty acid amides include oleic acid amides and erucic acid amides. Specific examples of the substituted amide include N-oleyl palmitate amide, N-stearyl stearyl amide, N-stearyl oleic acid amide, N-oleyl stealic acid amide, N-stearyl erucate amide and the like. Further, specific examples of trimethylolamide include trimethylolstearic acid amide. Specific examples of the saturated fatty acid bisamide include methylene bisstearic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide, ethylene bisstearic acid amide, ethylene bishydroxystearic acid amide, ethylene bisbechenic acid amide, and hexamethylene bisstea. Examples thereof include acid amides, hexamethylene bisbechenic acid amides, hexamethylene hydroxystearic acid amides, N, N'-distealyl adipic acid amides, N, N'-distearyl sebasic acid amides and the like. Specific examples of unsaturated fatty acid bisamides include ethylene bisoleic acid amides, ethylene biserukaic acid amides, hexamethylene bisoleic acid amides, N, N'-diorail adipic acid amides, and N, N'-diorail sevacinic acid amides. And so on. Specific examples of the fatty acid ester amide include stearoamide ethyl stearate and the like. Specific examples of the aromatic bisamide include m-xylylene bisstearic acid amide, m-xylylene bishydroxystearic acid amide, and N, N'-distearylisophthalic acid amide. The lubricant may be used alone or in combination of two or more.

When the lubricant is present on the surface of the heat-sealing resin layer, the abundance thereof is not particularly limited, but is preferably about 3 mg / m ² or more, more preferably in an environment of a temperature of 24 ° C. and a relative humidity of 60%. About 4 to 15 mg / m ² and more preferably about 5 to 14 mg / m ^{2 are mentioned.}

The heat-sealing resin layer 2 may contain a lubricant. Further, the lubricant existing on the surface of the heat-sealing resin layer 2 may be one that exudes the lubricant contained in the resin constituting the heat-sealing resin layer 2, or may be a heat-sealing resin layer. The surface of 2 may be coated with a lubricant.

The thickness of the heat-sealing resin layer 2 is not particularly limited, but the lower limit is preferably about 15 μm or more, more preferably about 20 μm or more, still more preferably about 30 μm or more, and the upper limit is preferable. Is about 100 μm or less, more preferably about 80 μm or less, still more preferably about 60 μm or less. The thickness range of the heat-sealing resin layer 2 is preferably about 15 to 100 μm, about 15 to 80 μm, about 15 to 60 μm, about 20 to 100 μm, about 20 to 80 μm, and about 20 to 60 μm. Examples thereof include about 30 to 100 μm, about 30 to 80 μm, and about 30 to 60 μm.

[Protective layer 3]
In the pouch-type package 11, the protective layer 3 is a layer provided as necessary for the purpose of improving designability, electrolytic solution resistance, scratch resistance, line suitability of packaging material, and the like. As described above, when the battery case of the present invention has the protective layer 3, the battery case has a laminated structure including the protective layer 3, the barrier layer 1, and the heat-sealing resin layer 2 in this order. The protective layer 3 may constitute the outer surface of the battery case of the present invention.

The material forming the protective layer 3 is not particularly limited as long as it has an insulating property. Examples of the material forming the protective layer 3 include polyolefin, polyester, polyamide, epoxy resin, acrylic resin, fluororesin, polyurethane, silicon resin, phenol resin, polyetherimide, polyimide, polycarbonate, and a mixture or copolymerization thereof. Things and the like can be mentioned. Among these, the protective layer 3 preferably has at least one of a layer formed of polyester and a layer formed of polyamide.

Examples of the polyolefin include polyethylene and polypropylene exemplified in the heat-sealing resin layer 2. As a specific example of the polyolefin, those exemplified in the heat-sealing resin layer 2 can be used. When polyolefin is used as the protective layer 3, there is an advantage that the used area of the battery case is reduced. When the protective layer 3 is a heat-fused polyolefin, the protective layer 3 and the heat-fused resin layer can be fused to each other, so that so-called caramel packaging is possible, and packaging that is closer to the battery element is possible, so that the size is reduced. This makes it possible to improve the volumetric energy density of the battery.

Specific examples of the polyester include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and ethylene terephthalate as the main constituents of the copolymerized polyester and butylene terephthalate as the main constituents of the repeating unit. Examples thereof include the copolymerized polyester. Further, as the copolymerized polyester having ethylene terephthalate as the main body of the repeating unit, specifically, a copolymer polyester having ethylene terephthalate as the main body of the repeating unit and polymerizing with ethylene isophthalate (hereinafter, polyethylene (terephthalate / isophthalate)). (Abbreviated after), polyethylene (terephthalate / isophthalate), polyethylene (terephthalate / adipate), polyethylene (terephthalate / sodium sulfoisophthalate), polyethylene (terephthalate / sodium isophthalate), polyethylene (terephthalate / phenyl-dicarboxylate) , Polyethylene (terephthalate / decandicarboxylate) and the like. Further, as the copolymerized polyester having butylene terephthalate as the main body of the repeating unit, specifically, a copolymer polyester which polymerizes with butylene isophthalate using butylene terephthalate as the main body of the repeating unit (hereinafter, polybutylene (terephthalate / isophthalate)). (Abbreviated after), polybutylene (terephthalate / adipate), polybutylene (terephthalate / sebacate), polybutylene (terephthalate / decantycarboxylate), polybutylene naphthalate and the like. These polyesters may be used alone or in combination of two or more. Polyester has an advantage that it has excellent electrolytic solution resistance and is less likely to cause whitening due to adhesion of the electrolytic solution, and is preferably used as a material for forming the protective layer 3.

Specific examples of the polyamide include an aliphatic polyamide such as nylon 6, nylon 66, nylon 610, nylon 12, nylon 46, and a copolymer of nylon 6 and nylon 66; terephthalic acid and / or isophthalic acid. Hexamethylenediamine-isophthalic acid-terephthalic acid copolymerized polyamides such as nylon 6I, nylon 6T, nylon 6IT, nylon 6I6T (I stands for isophthalic acid, T stands for terephthalic acid), polymethoxylylenazi Aroma-containing polyamides such as pamide (MXD6); alicyclic polyamides such as polyaminomethylcyclohexyl adipamide (PACM6); further copolymerized with a lactam component and an isocyanate component such as 4,4'-diphenylmethane-diisocyanate. Examples thereof include polyesteramide copolymers and polyetheresteramide copolymers, which are copolymers of polyamides and copolymerized polyamides with polyesters and polyalkylene ether glycols; and copolymers thereof. These polyamides may be used alone or in combination of two or more. The stretched polyamide film has excellent stretchability and bending resistance, and is suitably used as a material for forming the protective layer 3.

The protective layer 3 may be formed of a uniaxially or biaxially stretched resin film, or may be formed of an unstretched resin film. Among them, a uniaxially or biaxially stretched resin film, particularly a biaxially stretched resin film, has improved heat resistance due to orientation crystallization, and is therefore preferably used as the protective layer 3. Further, the protective layer 3 may be formed by coating the above material on the barrier layer 1.

Among these, examples of the resin film forming the protective layer 3 include polyolefin, nylon, and polyester, more preferably biaxially stretched nylon, biaxially stretched polyester, and particularly preferably biaxially stretched nylon.

In the protective layer 3, at least one of resin films and coatings of different materials can be laminated (multilayer structure) in order to improve pinhole resistance and insulation when used as a battery package. .. Specific examples thereof include a multilayer structure in which a polyester film and a nylon film are laminated, a multilayer structure in which a plurality of nylon films are laminated, and a multilayer structure in which a plurality of polyester films are laminated. When the protective layer 3 has a multilayer structure, a laminate of a biaxially stretched nylon film and a biaxially stretched polyester film, a laminate in which a plurality of biaxially stretched nylon films are laminated, and a laminate in which a plurality of biaxially stretched polyester films are laminated. Is preferable. For example, when the protective layer 3 is formed of two layers of resin film, the polyester resin and the polyester resin may be laminated, the polyamide resin and the polyamide resin may be laminated, or the polyester resin and the polyamide resin may be laminated. It is more preferable to have a structure in which polyethylene terephthalate and polyethylene terephthalate are laminated, a structure in which nylon and nylon are laminated, or a structure in which polyethylene terephthalate and nylon are laminated. Further, since the biaxially stretched polyester is difficult to discolor when the electrolytic solution adheres to the surface, for example, when the protective layer 3 has a multilayer structure of a biaxially stretched nylon film and a biaxially stretched polyester film, the protective layer 3 has a multilayer structure. The protective layer 3 is preferably a laminate having biaxially stretched nylon and biaxially stretched polyester in this order from the barrier layer 1 side. When the protective layer 3 has a multi-layer structure, the thickness of each layer is preferably about 3 to 25 μm.

When the protective layer 3 has a multilayer structure, each resin film may be adhered via an adhesive, or may be directly laminated without an adhesive. In the case of adhering without using an adhesive, for example, a method of adhering in a heat-melted state such as a coextrusion laminating method, a sandwich laminating method, and a thermal laminating method can be mentioned. When adhering via an adhesive, the adhesive used may be a two-component curable adhesive or a one-component curable adhesive. Further, the adhesive mechanism of the adhesive is not particularly limited, and may be any of a chemical reaction type, a solvent volatile type, a heat melting type, a thermal pressure type, an electron beam curing type, an ultraviolet curing type and the like. Specific examples of the adhesive include the same adhesives exemplified in the adhesive layer 4 described later. Further, the thickness of the adhesive can be the same as that of the adhesive layer 4.

In the present invention, from the viewpoint of enhancing the line suitability of the packaging material constituting the pouch-type packaging body 11, it is preferable that a lubricant is attached to the surface on the protective layer 3 side. The lubricant is not particularly limited, but an amide-based lubricant is preferable. As a specific example of the amide-based lubricant, the same one as exemplified in the heat-sealing resin layer 2 can be exemplified.

When the lubricant is present on the surface on the protective layer 3 side, the abundance thereof is not particularly limited, but is preferably about 3 mg / m ² or more, more preferably 4 to 4 in an environment of a temperature of 24 ° C. and a relative humidity of 60%. 15 mg / m ² about, even more preferably include about 5~14mg / m ^2.

The protective layer 3 may contain a lubricant. Further, the lubricant existing on the surface of the protective layer 3 may be one in which the lubricant contained in the resin constituting the protective layer 3 is exuded, or one in which the lubricant is applied to the surface of the protective layer 3. May be good.

The thickness of the protective layer 3 is preferably about 3 μm or more, more preferably about 10 to 75 μm, and further preferably about 10 to 50 μm from the viewpoint of reducing the thickness of the pouch-shaped package 11.

[Adhesive layer 4]
In the pouch-type package 11, the adhesive layer 4 is a layer provided between the protective layer 3 and the barrier layer 1 in order to firmly bond the protective layer 3 when the protective layer 3 is provided. ..

The adhesive layer 4 is formed by an adhesive capable of adhering the protective layer 3 and the barrier layer 1. The adhesive used to form the adhesive layer 4 may be a two-component curable adhesive or a one-component curable adhesive. Further, the adhesive mechanism used for forming the adhesive layer 4 is not particularly limited, and may be any of a chemical reaction type, a solvent volatile type, a heat melting type, a thermal pressure type and the like.

Specific examples of the adhesive component that can be used to form the adhesive layer 4 include polyester resins such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and copolymerized polyester; polyether. Adhesives; Polyurethane adhesives; Epoxy resins; Phenolic resins; Polyamide resins such as nylon 6, nylon 66, nylon 12, and copolymerized polyamides; polyolefins such as polyolefins, carboxylic acid-modified polyolefins, and metal-modified polyolefins. Resin, polyvinyl acetate resin; cellulose adhesive; (meth) acrylic resin; polyimide resin; polycarbonate; urea resin, amino resin such as melamine resin; rubber such as chloroprene rubber, nitrile rubber, styrene-butadiene rubber; Examples include silicone-based resins. These adhesive components may be used alone or in combination of two or more. Among these adhesive components, a polyurethane-based adhesive is preferable.

The thickness of the adhesive layer 4 is not particularly limited as long as it functions as an adhesive layer, and examples thereof include about 1 to 10 μm, preferably about 2 to 5 μm.

[Adhesive layer 5]
In the pouch-type package 11, the adhesive layer 5 is a layer provided between the barrier layer 1 and the heat-sealing resin layer 2 as necessary in order to firmly bond them.

The adhesive layer 5 is formed of a resin capable of adhering the barrier layer 1 and the heat-sealing resin layer 2. As the resin used for forming the adhesive layer 5, the same adhesive as the adhesive exemplified in the adhesive layer 4 can be used in terms of the adhesive mechanism, the type of adhesive component, and the like. Further, as the resin used for forming the adhesive layer 5, polyolefin-based resins such as the polyolefins exemplified in the above-mentioned heat-sealing resin layer 2, cyclic polyolefins, carboxylic acid-modified polyolefins, and carboxylic acid-modified cyclic polyolefins can also be used. .. From the viewpoint of excellent adhesion between the barrier layer 1 and the heat-sealing resin layer 2, the polyolefin is preferably a carboxylic acid-modified polyolefin, and particularly preferably a carboxylic acid-modified polypropylene. That is, the resin constituting the adhesive layer 5 may or may not contain a polyolefin skeleton, and preferably contains a polyolefin skeleton. The fact that the resin constituting the adhesive layer 5 contains a polyolefin skeleton can be analyzed by, for example, infrared spectroscopy, gas chromatography-mass spectrometry, or the like, and the analysis method is not particularly limited. For example, when measuring the infrared spectroscopy at a maleic anhydride-modified polyolefin, a peak derived from maleic acid is detected in the vicinity of the wave number of 1760 cm ^-1 and near the wave number 1780 cm ^-1. However, if the degree of acid denaturation is low, the peak may become small and may not be detected. In that case, it can be analyzed by nuclear magnetic resonance spectroscopy.

Further, from the viewpoint of reducing the thickness of the pouch-shaped package 11, the adhesive layer 5 may be a cured product of a resin composition containing an acid-modified polyolefin and a curing agent. As the acid-modified polyolefin, preferably, the same examples as the carboxylic acid-modified polyolefin and the carboxylic acid-modified cyclic polyolefin exemplified in the heat-sealing resin layer 2 can be exemplified.

The curing agent is not particularly limited as long as it cures the acid-modified polyolefin. Examples of the curing agent include an epoxy-based curing agent, a polyfunctional isocyanate-based curing agent, a carbodiimide-based curing agent, an oxazoline-based curing agent, and the like.

The epoxy-based curing agent is not particularly limited as long as it is a compound having at least one epoxy group. Examples of the epoxy-based curing agent include epoxy resins such as bisphenol A diglycidyl ether, modified bisphenol A diglycidyl ether, novolak glycidyl ether, glycerin polyglycidyl ether, and polyglycerin polyglycidyl ether.

The polyfunctional isocyanate-based curing agent is not particularly limited as long as it is a compound having two or more isocyanate groups. Specific examples of the polyfunctional isocyanate-based curing agent include isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), and those obtained by polymerizing or nurate these. Examples thereof include a mixture and a copolymer with another polymer.

The carbodiimide-based curing agent is not particularly limited as long as it is a compound having at least one carbodiimide group (-N = C = N-). As the carbodiimide-based curing agent, a polycarbodiimide compound having at least two or more carbodiimide groups is preferable.

The oxazoline-based curing agent is not particularly limited as long as it is a compound having an oxazoline skeleton. Specific examples of the oxazoline-based curing agent include the Epocross series manufactured by Nippon Shokubai Co., Ltd.

The curing agent may be composed of two or more kinds of compounds from the viewpoint of enhancing the adhesion between the barrier layer 1 by the adhesive layer 5 and the heat-sealing resin layer 2.

The content of the curing agent in the resin composition forming the adhesive layer 5 is preferably in the range of about 0.1 to 50% by mass, more preferably in the range of about 0.1 to 30% by mass. It is more preferably in the range of 0.1 to 10% by mass.

The thickness of the adhesive layer 5 is not particularly limited as long as it functions as an adhesive layer, but when the adhesive exemplified in the adhesive layer 4 is used, it is preferably about 1 to 10 μm, more preferably 1. The range is about 5 μm. Further, when the resin exemplified in the heat-sealing resin layer 2 is used, it is preferably about 2 to 50 μm, more preferably about 10 to 40 μm. Further, in the case of a cured product of the acid-modified polyolefin and the curing agent, it is preferably 30 μm or less, more preferably about 0.1 to 20 μm, and further preferably about 0.5 to 5 μm. When the adhesive layer 5 is a cured product of a resin composition containing an acid-modified polyolefin and a curing agent, the adhesive layer 5 can be formed by applying the resin composition and curing it by heating or the like.

[Surface coating layer]
In the pouch-type package 11, the outer side of the protective layer 3 (barrier layer 1 of the protective layer 3) is required for the purpose of improving designability, electrolytic solution resistance, scratch resistance, line suitability of the packaging material, and the like. A surface coating layer (not shown) may be further provided on the opposite side), if necessary.

The surface coating layer can be formed of, for example, polyvinylidene chloride, a polyester resin, a urethane resin, an acrylic resin, an epoxy resin, or the like. Among these, the surface coating layer is preferably formed of a two-component curable resin. Examples of the two-component curable resin forming the surface coating layer include a two-component curable urethane resin, a two-component curable polyester resin, and a two-component curable epoxy resin. Further, an additive may be added to the surface coating layer.

Examples of the additive include fine particles having a particle size of about 0.5 nm to 5 μm. The material of the additive is not particularly limited, and examples thereof include metals, metal oxides, inorganic substances, and organic substances. The shape of the additive is also not particularly limited, and examples thereof include a spherical shape, a fibrous shape, a plate shape, an amorphous shape, and a balloon shape. As additives, specifically, talc, silica, graphite, kaolin, montmoriloid, montmorillonite, synthetic mica, hydrotalcite, silica gel, zeolite, aluminum hydroxide, magnesium hydroxide, zinc oxide, magnesium oxide, aluminum oxide, Neodium oxide, antimony oxide, titanium oxide, cerium oxide, calcium sulfate, barium sulfate, calcium carbonate, calcium silicate, lithium carbonate, calcium benzoate, calcium oxalate, magnesium stearate, alumina, carbon black, carbon nanotubes, high Examples thereof include melting point nylon, cross-linked acrylic, cross-linked styrene, cross-linked polyethylene, benzoguanamine, gold, aluminum, copper and nickel. These additives may be used alone or in combination of two or more. Among these additives, silica, barium sulfate, and titanium oxide are preferable from the viewpoint of dispersion stability and cost. Further, the additive may be subjected to various surface treatments such as an insulation treatment and a highly dispersible treatment on the surface.

The method for forming the surface coating layer is not particularly limited, and examples thereof include a method of applying a two-component curable resin for forming the surface coating layer to the outer surface of the protective layer 3. When the additive is blended, the additive may be added to the two-component curable resin, mixed, and then applied.

The thickness of the surface coating layer is not particularly limited as long as it exhibits the above-mentioned function as the surface coating layer, and examples thereof include about 0.5 to 10 μm, preferably about 1 to 5 μm.

Method for manufacturing packaging material constituting the pouch-type packaging body 11 The method for manufacturing the packaging material constituting the pouch-type packaging body 11 is not particularly limited as long as a laminated body in which each layer having a predetermined composition is laminated can be obtained. At least, it suffices to include a step of laminating the barrier layer 1 and the heat-sealing resin layer 2. Further, it can be designed so that the ratio of the thickness of the heat-sealing resin layer 2 to the thickness of the laminated body is 20% or more. In order to design the ratio of the thickness of the heat-sealing resin layer 2 to the thickness of the laminate to be 20% or more, as described above, the barrier layer 1 and the heat-sealing resin layer 2 are designed. The composition, thickness, and various physical properties may be adjusted.

An example of a method for manufacturing a packaging material is as follows. First, a laminated body in which the protective layer 3, the adhesive layer 4, and the barrier layer 1 are laminated in this order (hereinafter, may be referred to as “laminated body A”) is formed. Specifically, the layered body A is formed by applying an adhesive used for forming the adhesive layer 4 on the protective layer 3 or, if necessary, on the barrier layer 1 having a chemical conversion treatment on the surface, by a gravure coating method or a roll. It can be carried out by a dry laminating method in which the barrier layer 1 or the protective layer 3 is laminated and the adhesive layer 4 is cured after being applied and dried by a coating method such as a coating method.

Next, the adhesive layer 5 and the heat-sealing resin layer 2 are laminated on the barrier layer 1 of the laminated body A in this order. For example, (1) a method of laminating the adhesive layer 5 and the heat-sealing resin layer 2 on the barrier layer 1 of the laminated body A by co-extruding (co-extruded laminating method), (2) separately, the adhesive layer 5 A method of forming a laminated body in which the heat-sealing resin layer 2 is laminated and laminating this on the barrier layer 1 of the laminated body A by a thermal laminating method, (3) adhesion on the barrier layer 1 of the laminated body A. An adhesive for forming the layer 5 is laminated by an extrusion method or a solution coating, dried at a high temperature, and then baked, and a heat-sealing resin layer 2 is previously formed into a sheet on the adhesive layer 5. A method of laminating by a thermal laminating method, (4) Adhesion while pouring a melted adhesive layer 5 between the barrier layer 1 of the laminated body A and the heat-sealing resin layer 2 previously formed into a sheet. Examples thereof include a method of laminating the laminate A and the heat-sealing resin layer 2 via the layer 5 (sandwich laminating method).

When the surface coating layer is provided, the surface coating layer is laminated on the surface of the protective layer 3 opposite to the barrier layer 1. The surface coating layer can be formed, for example, by applying the above resin that forms the surface coating layer to the surface of the protective layer 3. The order of the step of laminating the barrier layer 1 on the surface of the protective layer 3 and the step of laminating the surface coating layer on the surface of the protective layer 3 is not particularly limited. For example, after forming the surface coating layer on the surface of the protective layer 3, the barrier layer 1 may be formed on the surface of the protective layer 3 opposite to the surface coating layer.

As described above, the surface coating layer provided as needed / the protective layer 3 provided as needed / the adhesive layer 4 provided as needed / the barrier layer 1 / the adhesive layer 5 provided as needed. / A laminate composed of the heat-sealing resin layer 2 is formed, but in order to strengthen the adhesiveness of the adhesive layer 4 or the adhesive layer 5, a hot roll contact type, a hot air type, near or far infrared rays are further formed. It may be subjected to heat treatment such as a formula. Examples of the conditions for such heat treatment include about 1 to 5 minutes at about 150 to 250 ° C.

Each layer constituting the laminated body of the pouch type package 11 is used to improve or stabilize the film forming property, the laminated processing, the suitability for the secondary processing (pouching, embossing) of the final product, etc., as necessary. Surface activation treatments such as corona treatment, blast treatment, oxidation treatment, and ozone treatment may be performed.

Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples. However, the present invention is not limited to the examples.

<Manufacturing of packaging materials that make up pouch-shaped packaging>
(Packaging material A)
An aluminum foil (JIS H4160: 1994 1N30, thickness 40 μm) as a barrier layer was laminated on a stretched nylon film (thickness 25 μm) as a protective layer by a dry laminating method. Specifically, a two-component urethane adhesive (polyol compound and aromatic isocyanate compound) is applied to one surface of an aluminum foil having an acid-resistant film formed on its surface, and an adhesive layer (thickness) is applied on the aluminum foil. 3 μm) was formed. Next, the adhesive layer and the protective layer on the barrier layer were laminated by a dry laminating method, and then an aging treatment was performed to prepare a laminated body of the protective layer / adhesive layer / barrier layer. The acid-resistant film formed on the surface of the aluminum foil is a roll of a treatment liquid consisting of a phenol resin, a chromium fluoride compound, and phosphoric acid so that the coating amount of chromium is 10 mg / m ^{2 (dry mass).} It is formed by applying it to both sides of an aluminum foil by a coating method and baking it.

Next, by laminating a polypropylene film (CPP, thickness 45 μm) as a heat-sealing resin layer on the other surface of the aluminum foil by a dry laminating method, an adhesive layer (3 μm) / heat is applied to the surface of the barrier layer. A fused resin layer was laminated. An olefin resin composition (acid-modified polypropylene and epoxy compound) was used as the adhesive layer. Next, the obtained laminate was aged and heated to obtain a packaging material A in which a protective layer / adhesive layer / barrier layer / adhesive layer / heat-sealing resin layer were laminated in this order. Table 1 shows a specific laminated structure.

(Packaging material B)
A packaging material B was obtained in the same manner as the packaging material A, except that the thickness of the polypropylene film (CPP) as the heat-sealing resin layer was 25 μm. Table 1 shows a specific laminated structure.

(Preparation of test sample)
As a protective member, an amorphous polyethylene terephthalate sheet (A-PET) having a width of 15 mm, a length of 100 mm, and a thickness of 0.05 mm, 0.20 mm, or 0.40 mm was prepared. Next, the packaging material obtained above was cut into a width of 15 mm and a length of 100 mm, and the outer surface (stretched nylon film side) thereof and the protective member were bonded with an adhesive (modified olefin adhesive, thickness 5 μm). They were adhered and laminated to prepare a test sample having a width of 15 mm and a length of 100 mm. In Examples 1 to 4 and Comparative Examples 1 to 4, the combinations of the packaging material constituting the pouch-shaped package and the protective member are as shown in Table 1. For example, in Example 1, each test sample was obtained using the packaging material A and A-PET (protective member) having a thickness of 0.40 mm.

<Evaluation of sealability of pouch-type package>
Regarding the packaging material A and the packaging material B obtained above, two members (10a and 10b in FIG. 1) cut to a size of 100 mm × 150 mm and a member (10c in FIG. 1) cut to a size of 100 mm × 70 mm 1 I prepared a sheet. Next, the peripheral edges of the three members are heat-sealed so that the heat-sealing resin layer is on the inside so as to form a gusset bag as shown in the schematic views of FIGS. 1 to 3. rice field. The heating / pressurizing conditions for heat-sealing each portion were a temperature of 170 ° C., a pressure of 1 MPa, and a time of 3 seconds for heating and crimping twice to obtain a seal width of 5 mm. At this time, the uppermost portion in the y direction (the portion opposite to the bottom surface in the y direction) in FIGS. 1 to 3 was set as an opened portion and was not heat-sealed. Next, in an environment of room temperature (25 ° C.) and atmospheric pressure (1 atm), 3 g of a penetrant (Microcheck Penetrant Co., Ltd. Ichinen Chemicals Co., Ltd.) was added from the opening part, and 15 minutes later, it is shown in FIGS. It was visually confirmed whether or not the penetrant was leaking from the two P portions. If the penetrant did not leak, it was evaluated as "A" with good sealing performance, and if the penetrant had penetrated in a part of the seal part but did not reach the outer edge of the seal part and there was no problem in use, the sealability is possible. It was evaluated as "B", and the case where the penetrant reached the outer edge of the sealing portion and leaked was evaluated as poor sealing property "C". The results are shown in Table 1.

<Measurement of tensile elastic modulus and tensile fracture strength>
The tensile elastic modulus and tensile fracture strength of each test sample obtained above were measured by a method in accordance with JIS K7127: 1999, respectively. The measurement conditions were a rectangular shape of the sample (width 15 mm, length 100 mm), a distance between marked lines of 50 mm, and a tensile speed of 100 mm / min. The results are shown in Table 1. In this measurement, the MPa unit is MN / m ^2, which is a value obtained by dividing the force by the area. Therefore, the effect of changing the thickness of the protective member cannot be expressed, so N / 15 mm reflecting the effect of the thickness. Uses the unit of.

<Evaluation of shape retention>
A pouch-type package (gusset bag) produced in the above <Evaluation of sealability of pouch-type package> was prepared. A polypropylene resin plate (500 g) was enclosed as a dummy cell in each pouch-shaped package. At this time, the uppermost portion of FIGS. 1 to 3 in the y direction (the portion opposite to the bottom surface in the y direction) was also heat-sealed to seal the dummy cell. Next, each material shown in Table 1 was used to form the protective member of FIG. 7. Next, the pouch-shaped package containing the dummy cell is placed in the protective member so that the protective member covers the side surface and the bottom surface of the outer surface of the pouch-type package, and these are fixed with an adhesive to evaluate the sample. Was produced. According to JIS Z 0200: 2013, a free fall test was carried out for each evaluation sample (less than 10 kg, level III, 10 pieces each), and the shape retention state after the test was confirmed. "◎" when holding 10 out of 10 shapes, "○" when holding 8 to 9 shapes, "△" when holding 6 to 7 shapes, 0 The case where ~ 5 shapes were held was evaluated as "x".

In the laminated structure shown in Table 1, ONy means a stretched nylon film, DL means an adhesive layer or an adhesive layer formed by a dry laminating method, ALM means an aluminum foil, and CPP means an unstretched polypropylene film. Further, the numerical value described after each layer of the laminated structure means a thickness (μm), for example, “ONy25” means “a stretched nylon film having a thickness of 25 μm”.

As is clear from the results shown in Table 1, the battery cases of Examples 1 to 4 include a pouch-shaped package and a protective member that covers the outer surface of the pouch-shaped package, and the thickness of the protective member is 0. Since it is 1 to 1.0 mm, it can be seen that the tensile elastic modulus and the tensile fracture strength are improved and the mechanical strength is high. Further, the battery cases of Examples 1 to 4 were also excellent in shape retention.

1 Barrier layer 2 Heat-sealing resin layer 3 Protective layer 4 Adhesive layer 5 Adhesive layer 10 Packaging material 10a Packaging material 10b Packaging material 10c Packaging material 11 Pouch type packaging 12 Protective member 20 Battery case

Claims (7)

A pouch-shaped package and a protective member that covers at least a part of the outer surface of the pouch-shaped package.
It is a battery case equipped with
The protective member is a case for a battery, which is a polyester sheet having a thickness of 0.1 mm or more and 0.8 mm or less. The pouch-type package is provided with a side surface portion, wherein the protective member covers at least the side surface portion of the outer surface of the pouch-type package, case for battery according to claim 1. The first or second aspect of the present invention, wherein the pouch-shaped package includes a side surface portion and a bottom surface portion, and the protective member covers at least the side surface portion and the bottom surface portion of the outer surface of the pouch-shaped package body. Battery case. The pouch-type package is composed of a laminate having at least a barrier layer and a heat-sealing resin layer.
The battery case according to any one of claims 1 to 3 , wherein the ratio of the thickness of the heat-sealing resin layer to the thickness of the laminate is 20% or more. The battery case according to claim 4 , wherein the barrier layer has a thickness of 10 μm or more and 40 μm or less. The pouch type package is provided with a protective layer on the opposite side of the heat-fusible resin layer side of the barrier layer, battery case according to claim 4 or 5. A battery in which a battery element including at least a positive electrode, a negative electrode, and an electrolyte is housed in the pouch-shaped package of the battery case according to any one of claims 1 to 6.

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