JP7314970B2 - BATTERY PACKAGING MATERIAL, MANUFACTURING METHOD THEREOF, AND BATTERY - Google Patents

Description

TECHNICAL FIELD The present invention relates to a battery packaging material, a manufacturing method thereof, and a battery.

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

On the other hand, in recent years, with the increasing performance of electric vehicles, hybrid electric vehicles, personal computers, cameras, mobile phones, etc., batteries are required to have various shapes and to be thinner and lighter. However, metal battery packaging materials, which have been widely used in the past, have drawbacks in that it is difficult to follow 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 realize thinness and weight reduction, a film-like laminate in which a substrate / metal layer / heat-fusible resin layer is sequentially laminated has been proposed.

In such a battery packaging material, generally, recesses are formed by cold forming, battery elements such as electrodes and electrolytic solution are arranged in the spaces formed by the recesses, and the heat-fusible resin layers are heat-sealed to each other to obtain a battery in which the battery elements are housed inside the battery packaging material. However, such film-like packaging materials are thinner than metallic packaging materials, and have the disadvantage of being susceptible to pinholes and cracks during molding. If pinholes or cracks occur in the battery packaging material, the electrolytic solution may permeate the metal layer to form metal deposits, which may result in short circuits. Therefore, it is essential that the film-like battery packaging material has the property that pinholes are unlikely to occur during molding, that is, it has excellent moldability.

In recent years, along with the demand for smaller and thinner batteries, there is a demand for even thinner packaging materials for batteries. However, when the thickness of the battery packaging material becomes thin, the metal layer also becomes thin (for example, 40 μm or less, further 35 μm or less), so there is a problem that pinholes and cracks are likely to occur in the metal layer during molding. Polyamide films such as nylon films are widely used as base layers of thin packaging materials for batteries from the viewpoint of excellent moldability (see Patent Document 1, for example).

JP 2008-288117 A

As described above, in thin packaging materials for batteries, moldability is enhanced by using a polyamide resin such as nylon as a base layer.

On the other hand, there is a problem that the insulating properties of the battery are deteriorated as the thickness of the battery packaging material is reduced. However, when a polyamide resin such as nylon is used, although the moldability is excellent, the insulation may be insufficient.

In order to improve the insulating properties of thin packaging materials for batteries, the present inventors have investigated the use of polyester as the base material layer. However, since polyester such as polyethylene terephthalate is inferior to nylon in moldability, when the base layer is formed of polyester, for example, if the thickness of the metal layer is made very thin (for example, 40 μm or less, further 35 μm or less), a problem arises that pinholes and the like are likely to occur in the metal layer during molding of the battery packaging material.

Under such circumstances, the main object of the present invention is to provide a battery packaging material comprising a laminate comprising at least a base material layer made of polyester, a metal layer, and a heat-sealable resin layer in this order, which has excellent insulation properties, is less prone to pinholes and cracks during molding, and has excellent moldability.

In addition, along with the demand for smaller and thinner batteries, there is a demand for further thinning of the battery packaging material. If curling occurs, it may impede housing of the battery element and heat-sealing of the heat-sealable resin layer, thereby reducing production efficiency of the battery.

As a result of investigation by the present inventors, it was found that such a problem of curling is likely to occur when a polyester film is used as the layer located on the outer layer side of the battery packaging material. In particular, battery packaging materials used for large-sized secondary batteries, such as secondary batteries for automobiles, are large in size, and therefore have the problem that curling has a very large effect on the productivity of the battery.

Under such circumstances, the main object of the present invention is to provide a battery packaging material comprising a laminate comprising at least a base material layer, an adhesive layer, a metal layer, and a heat-sealable resin layer in this order, and having excellent moldability and effectively suppressing curling after molding.

The present inventors have made extensive studies to solve the above problems. As a result, the present inventors found that, in a battery packaging material comprising a laminate comprising at least a base material layer made of polyester, a metal layer, and a heat-fusible resin layer in this order, the metal layer used has a thickness of 40 μm or less. In addition, the present inventors have found that at least a laminate comprising a substrate layer containing polyester, a metal layer, and a heat-fusible resin layer in this order, the substrate layer having a length of 100 mm and a width of 15 mm is pulled at a tensile speed of 50 mm / min at 25 ° C., and the displacement when a tensile stress of 15 MPa is applied is 5% or less. Therefore, it was found that a battery packaging material having a displacement of 5% or less when a tensile stress of 40 MPa is applied has excellent moldability, and curling after molding is effectively suppressed. The present invention has been completed through further studies based on these findings.

That is, the present invention provides a battery packaging material and a battery according to the following aspects.
Section 1. At least, a laminate comprising a substrate layer, a metal layer, and a heat-fusible resin layer in this order,
The thickness of the metal layer is 40 μm or less,
The base material layer is formed of polyester,
The battery packaging material, wherein the base material layer has a thickness of 15 μm or more and 30 μm or less.
Section 2. Item 2. The battery packaging material according to Item 1, wherein the laminate has a thickness of 140 μm or less.
Item 3. Item 3. The battery packaging material according to Item 1 or 2, wherein the base material layer is composed of a single layer made of polyester.
Section 4. Item 3. The battery packaging material according to Item 1 or 2, wherein the base material layer is composed of a plurality of layers made of polyester.
Item 5. Item 5. The battery packaging material according to any one of Items 1 to 4, comprising an acid-resistant film layer on at least one surface of the metal layer.
Item 6. Item 6. The battery packaging material according to any one of Items 1 to 5, wherein the metal layer is an aluminum foil.
Item 7. At least a step of obtaining a laminate comprising a substrate layer, a metal layer, and a heat-fusible resin layer in this order,
Using a metal layer having a thickness of 40 μm or less,
A method for producing a battery packaging material, wherein the substrate layer is made of polyester and has a thickness of 15 μm or more and 30 μm or less.
Item 8. At least, a laminate comprising a substrate layer containing polyester, a metal layer, and a heat-fusible resin layer in this order,
The base material layer having a length of 100 mm and a width of 15 mm is pulled at a tensile speed of 50 mm / min at 25 ° C., and the displacement when a tensile stress of 15 MPa is applied is 5% or less,
A packaging material for a battery, wherein the laminate having a length of 100 mm and a width of 15 mm is stretched at a tensile speed of 50 mm/min at 25° C. and has a displacement of 5% or less when a tensile stress of 40 MPa is applied.
Item 9. Item 9. A battery, wherein a battery element comprising at least a positive electrode, a negative electrode, and an electrolyte is housed in a package formed of the battery packaging material according to any one of items 1 to 8.

According to the present invention, in a battery packaging material comprising a laminate comprising at least a base material layer made of polyester, a metal layer, and a heat-sealable resin layer in this order, the thickness of the base material layer is set to 15 μm or more and 30 μm or less, even though the metal layer has a thickness of 40 μm or less. Thus, it is possible to provide a battery packaging material that has not only excellent insulation properties but also excellent moldability. Moreover, according to the present invention, it is possible to provide a battery packaging material which has excellent moldability and which effectively suppresses curling after molding.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows an example of the cross-sectional structure of the packaging material for batteries of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows an example of the cross-sectional structure of the packaging material for batteries of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows an example of the cross-sectional structure of the packaging material for batteries of this invention. It is a schematic diagram for demonstrating the curl evaluation method. It is a schematic diagram for demonstrating the curl evaluation method. 5 is a graph showing the relationship between tensile stress (MPa) and displacement (%) when a test piece prepared from the base layer of the battery packaging material of Examples 1B, 2B, and 6B is pulled. 5 is a graph showing the relationship between tensile stress (MPa) and displacement (%) when a test piece prepared from the base layer of the battery packaging material of Comparative Examples 1B, 4B, and 5B is pulled. 5 is a graph showing the relationship between tensile stress (MPa) and displacement (%) when a test piece prepared from the battery packaging material of Examples 1B, 2B, and 6B is pulled. 5 is a graph showing the relationship between tensile stress (MPa) and displacement (%) when a test piece produced from the battery packaging material of Comparative Examples 1B, 4B, and 5B is pulled.

A battery packaging material according to a first aspect of the present invention comprises a laminate comprising at least a substrate layer, a metal layer, and a heat-fusible resin layer in this order, wherein the thickness of the metal layer is 40 μm or less, the substrate layer is made of polyester, and the thickness of the substrate layer is 15 μm or more and 30 μm or less. Since the battery packaging material of the first aspect of the present invention has such a structure, it not only has excellent insulation properties, but also has excellent moldability. Further, the battery packaging material of the second aspect of the present invention is composed of a laminate comprising at least a base material layer containing polyester, a metal layer, and a heat-fusible resin layer in this order. It is characterized by a displacement of 5% or less when it is pulled at a tensile speed of 50 mm/min and a tensile stress of 40 MPa is applied. Since the battery packaging material of the second aspect of the present invention has such a configuration, it has excellent moldability, and curling after molding is effectively suppressed. The battery packaging material of the present invention will be described in detail below.

In this specification, the indication of "~" indicating a numerical range indicates that it is equal to or greater than the numerical value attached to the left side and equal to or less than the numerical value attached to the right side.

1. Laminate Structure of Battery Packaging Material As shown in FIG. 1, the battery packaging material is composed of a laminate comprising at least a substrate layer 1, a metal layer 3, and a heat-fusible resin layer 4 in this order. In the battery packaging material of the present invention, the substrate layer 1 is the outermost layer, and the heat-fusible resin layer 4 is the innermost layer. That is, when the battery is assembled, the heat-fusible resin layers 4 positioned at the periphery of the battery element are heat-sealed to seal the battery element, thereby sealing the battery element.

In the battery packaging material of the present invention, as shown in FIG. 2, an adhesive layer 2 may be provided between the base material layer 1 and the metal layer 3 for the purpose of enhancing the adhesion between them, if necessary. In the battery packaging material of the present invention, as shown in FIG. 3, an adhesive layer 5 may be provided between the metal layer 3 and the heat-sealable resin layer 4, if necessary, for the purpose of enhancing the adhesion between them.

The thickness of the laminate constituting the battery packaging material of the present invention is not particularly limited, but from the viewpoint of effectively suppressing deterioration of moldability and insulation while reducing the thickness, it is preferably 150 μm or less, more preferably about 110 μm to 145 μm. Even when the thickness of the laminate constituting the battery packaging material of the present invention is very thin, for example, 150 μm or less, according to the first aspect of the present invention, the occurrence of pinholes and the like due to molding can be effectively suppressed, and further, the deterioration of insulation can be effectively suppressed. Moreover, according to the second aspect of the present invention, the occurrence of pinholes and the like due to molding is effectively suppressed, and curling after molding is effectively suppressed. Therefore, the battery packaging material of the present invention can contribute to improving the energy density of the battery, and can also improve the productivity of the battery.

In addition, when the laminate constituting the battery packaging material of the second aspect of the present invention has a length of 100 mm and a width of 15 mm, it is pulled at a tensile speed of 50 mm/min at 25° C., and the displacement when a tensile stress of 40 MPa is applied is 5% or less. The displacement is preferably about 2% to 4%.

2. Each layer forming the battery packaging material [base layer 1]
In the battery packaging material of the present invention, the substrate layer 1 is a layer forming the outermost layer. The base material layer 1 is made of polyester. As described above, in recent years, along with the demand for smaller and thinner batteries, there is a demand for even thinner packaging materials for batteries. However, when the thickness of the battery packaging material is reduced, there is a problem that pinholes and cracks tend to occur in the metal layer during molding. Furthermore, it becomes easy to fall also about insulation.

On the other hand, in the first aspect of the present invention, the substrate layer 1 is made of polyester and has a thickness in the range of 15 μm to 30 μm. This effectively suppresses the occurrence of pinholes and cracks in the metal layer 3, and further improves the insulation dramatically compared to the case of forming with nylon or the like. When the thickness of the battery packaging material is reduced, the moldability is lowered. Therefore, it has been unthinkable to use a resin such as polyester, which has poor moldability, alone for the base material layer. Therefore, it was surprising that the thickness of the base material layer 1 made of polyester was set within the above-mentioned specific range to provide a battery packaging material having excellent moldability as well as insulating properties. Although the details of the mechanism by which excellent moldability is exhibited in spite of the use of polyester in the battery packaging material of the present invention are not clear, for example, it can be considered as follows. That is, in the present invention, the thickness of the base material layer 1 made of polyester is set within the specific range described above, so that the base material layer 1 appropriately controls the rapid elongation of the metal layer 3 during molding.

Specific examples of the polyester include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, polycarbonate, copolymer polyester mainly composed of repeating units of ethylene terephthalate, and copolymer polyester mainly composed of repeating units of butylene terephthalate. Further, the copolymer polyester having ethylene terephthalate as the main repeating unit specifically includes a copolymer polyester polymerized with ethylene isophthalate having ethylene terephthalate as the main repeating unit (hereinafter abbreviated according to polyethylene (terephthalate/isophthalate)), polyethylene (terephthalate/isophthalate), polyethylene (terephthalate/adipate), polyethylene (terephthalate/sodium sulfoisophthalate), polyethylene (terephthalate/sodium isophthalate), and polyethylene (terephthalate/phenyl-dicarboxylate). , polyethylene (terephthalate/decanedicarboxylate), and the like. Further, as the copolymerized polyester having butylene terephthalate as the main repeating unit, specifically, a copolymer polyester polymerized with butylene isophthalate having butylene terephthalate as the main repeating unit (hereinafter abbreviated after polybutylene (terephthalate/isophthalate)), polybutylene (terephthalate/adipate), polybutylene (terephthalate/sebacate), polybutylene (terephthalate/decanedicarboxylate), polybutylene phthalate and the like. These polyesters may be used singly or in combination of two or more. Among these, polyethylene terephthalate has the advantage of being excellent in electrolytic solution resistance and less likely to cause whitening or the like due to adhesion of the electrolytic solution.

In the first aspect, the thickness of the base material layer 1 is not particularly limited as long as it is in the range of 15 μm to 30 μm, but it is more preferably about 20 μm to 25 μm from the viewpoint of ensuring excellent insulation and excellent moldability while further reducing the thickness of the battery packaging material. As will be described later, when the base layer 1 is composed of a plurality of layers and each layer is adhered with an adhesive component such as an adhesive, the thickness of the adhesive component is not included in the thickness of the base layer 1. This is because the adhesive component does not substantially contribute to improving the insulating properties and moldability of the battery packaging material.

The base material layer 1 may be composed of a single layer made of polyester, or may be composed of a plurality of layers made of polyester. When the substrate layer 1 is composed of a plurality of layers, it is preferably composed of two layers made of polyester.

The substrate layer 1 can preferably be composed of a polyester film, particularly preferably a polyethylene terephthalate film. When the substrate layer 1 is composed of a plurality of layers, a two-layer structure in which a polyethylene terephthalate film and a polyethylene terephthalate film are laminated is particularly preferable.

When the base material layer 1 is composed of a plurality of layers, the layers may be laminated via an adhesive component such as an adhesive or an adhesive resin, and the type and amount of the adhesive component used are the same as in the adhesive layer 2 described later. The method for laminating two or more layers of polyester films is not particularly limited, and known methods can be employed, such as dry lamination and sandwich lamination, preferably dry lamination. When laminating by a dry lamination method, it is preferable to use a urethane-based adhesive as the adhesive layer. At this time, the thickness of the adhesive layer is, for example, about 2 μm to 5 μm.

In the second aspect of the present invention, the substrate layer 1 has a length of 100 mm and a width of 15 mm, is pulled at a tensile speed of 50 mm/min at 25° C., and has a displacement of 5% or less when a tensile stress of 15 MPa is applied. The displacement is preferably about 2% to 4%. In the second aspect of the present invention, the displacement of the laminate described above is within the predetermined range and the displacement of the base material layer 1 is 5% or less, thereby effectively suppressing the occurrence of pinholes and the like due to molding, and furthermore effectively suppressing curling after molding. In the second aspect of the present invention, the thickness of the substrate layer 1 is, for example, about 10 μm to 50 μm, preferably about 12 μm to 30 μm.

The base material layer 1 may be made to have low friction in order to improve moldability. When the friction coefficient of the base material layer 1 is to be reduced, the friction coefficient of the surface thereof is not particularly limited, but may be, for example, 1.0 or less. In order to reduce the friction of the base material layer 1, for example, matte treatment, formation of a thin film layer of a lubricant, a combination thereof, and the like can be mentioned.

Examples of the matte treatment include adding a matting agent to the substrate layer 1 in advance to form unevenness on the surface, a transfer method by heating or pressing with an embossing roll, and a dry or wet blasting method or a method of mechanically roughening the surface with a file. Matting agents include, for example, fine particles having a particle size of about 0.5 nm to 5 μm. The material of the matting agent is not particularly limited, and examples thereof include metals, metal oxides, inorganic substances, organic substances and the like. The shape of the matting agent is also not particularly limited, and examples thereof include spherical, fibrous, plate-like, amorphous, balloon-like, and the like. Specific examples of matting agents include talc, silica, graphite, kaolin, montmorilloid, montmorillonite, synthetic mica, hydrotalcite, silica gel, zeolite, aluminum hydroxide, magnesium hydroxide, zinc oxide, magnesium oxide, aluminum oxide, neodymium 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 melting point nylon, cross-linked. Acrylic, crosslinked styrene, crosslinked polyethylene, benzoguanamine, gold, aluminum, copper, nickel and the like. These matting agents may be used singly or in combination of two or more. Among these matting agents, silica, barium sulfate, and titanium oxide are preferred from the viewpoint of dispersion stability, cost, and the like. In addition, the matting agent may be subjected to various surface treatments such as insulation treatment and high-dispersion treatment.

The thin film layer of the lubricant can be formed by depositing the lubricant on the surface of the substrate layer 1 by bleeding out to form a thin layer, or by laminating the lubricant on the substrate layer 1 . Examples of the lubricant include, but are not limited to, amide-based lubricants, metal soaps, hydrophilic silicones, silicone-grafted acrylics, silicone-grafted epoxies, silicone-grafted polyethers, silicone-grafted polyesters, block-type silicone-acrylic copolymers, polyglycerol-modified silicones, and paraffins. These lubricants may be used singly or in combination of two or more.

[Adhesive layer 2]
In the battery packaging material of the present invention, the adhesive layer 2 is a layer provided between the substrate layer 1 and the metal layer 3 in order to firmly bond them.

The adhesive layer 2 is made of an adhesive capable of bonding the base material layer 1 and the metal layer 3 together. The adhesive used to form the adhesive layer 2 may be a two-component curing adhesive or a one-component curing adhesive. Furthermore, the adhesion mechanism of the adhesive used to form the adhesive layer 2 is not particularly limited, and may be any of chemical reaction type, solvent volatilization type, heat melting type, heat pressure type, and the like.

Specific examples of adhesive components that can be used to form the adhesive layer 2 include polyester resins such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, polycarbonate, and copolymerized polyester; polyether adhesives; polyurethane adhesives; epoxy resins; vinyl acetate resin; cellulose adhesive; (meth)acrylic resin; polyimide resin; amino resin such as urea resin and melamine resin; rubber such as chloroprene rubber, nitrile rubber and styrene-butadiene rubber; These adhesive components may be used singly or in combination of two or more. Among these adhesive components, polyurethane-based adhesives are preferred.

The thickness of the adhesive layer 2 is not particularly limited as long as it functions as an adhesive layer.

[Metal layer 3]
In the battery packaging material, the metal layer 3 is a layer that functions as a barrier layer for improving the strength of the battery packaging material and also for preventing water vapor, oxygen, light, etc. from entering the battery. Specific examples of the metal forming the metal layer 3 include aluminum, stainless steel, titanium, and the like, preferably aluminum. The metal layer 3 can be formed by metal foil, metal vapor deposition, or the like, preferably by metal foil, and more preferably by aluminum foil. From the viewpoint of preventing the occurrence of wrinkles and pinholes in the metal layer 3 during the production of the battery packaging material, for example, a soft material such as annealed aluminum (JIS H4160 A8021H-O, JIS H4160 A8079H-O, JIS H4000:2014 A8021P-O, JIS H4000:2014 A8079P-O) is used. It is more preferable to form with a high quality aluminum foil.

In the battery packaging material of the first aspect of the present invention, the thickness of the metal layer 3 is 40 μm or less. As a result, the battery packaging material of the present invention can be made thin. From the viewpoint of achieving both formability and insulation while making the battery packaging material thinner, the thickness of the metal layer 3 is more preferably 35 μm or less, more preferably about 10 μm to 35 μm. On the other hand, in the battery packaging material of the second aspect of the present invention, the thickness of the metal layer 3 is not limited to 40 μm or less. In the second aspect of the present invention, the thickness of the metal layer 3 is not particularly limited as long as it functions as a barrier layer against water vapor.

Moreover, the metal layer 3 preferably has an acid-resistant film layer formed by chemical conversion treatment on at least one surface, preferably both surfaces thereof, in order to stabilize adhesion and prevent dissolution and corrosion. Here, chemical conversion treatment refers to treatment for forming an acid-resistant film on the surface of a metal layer. Examples of the chemical conversion treatment include chromate chromate treatment using a chromic acid compound such as chromium nitrate, chromium fluoride, chromium sulfate, chromium acetate, chromium oxalate, chromium biphosphate, acetyl chromate acetate, chromium chloride, and potassium chromium sulfate; phosphate chromate treatment using a phosphoric acid compound such as sodium phosphate, potassium phosphate, ammonium phosphate, and polyphosphoric acid; and chromate treatment using an aminated phenol polymer having a repeating unit represented by the following general formulas (1) to (4). be done. In the aminated phenol polymer, repeating units represented by the following general formulas (1) to (4) may be contained singly or in any combination of two or more.

In general formulas (1) to (4), X represents a hydrogen atom, hydroxyl group, alkyl group, hydroxyalkyl group, allyl group or benzyl group. R ¹ and R ² are the same or different and represent a hydroxyl group, an alkyl group or a hydroxyalkyl group. Examples of alkyl groups represented by X, R ¹ and R ² in general formulas (1) to (4) include linear or branched alkyl groups having 1 to 4 carbon atoms such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group and tert-butyl group. Examples of hydroxyalkyl groups represented by X, R ¹ and R ² include linear or branched C 1-4 alkyl groups substituted with one hydroxy group such as hydroxymethyl group, 1-hydroxyethyl group, 2-hydroxyethyl group, 1-hydroxypropyl group, 2-hydroxypropyl group, 3-hydroxypropyl group, 1-hydroxybutyl group, 2-hydroxybutyl group, 3-hydroxybutyl group and 4-hydroxybutyl group. In general formulas (1) to (4), the alkyl groups and hydroxyalkyl groups represented by X, R ¹ and R ² may be the same or different. In 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 aminated phenol polymer having repeating units represented by formulas (1) to (4) is preferably, for example, 500 to 1,000,000, more preferably about 1,000 to 20,000.

Further, as a chemical conversion treatment method for imparting corrosion resistance to the metal layer 3, there is a method of forming a corrosion-resistant layer on the surface of the metal layer 3 by coating phosphoric acid with fine particles of a metal oxide such as aluminum oxide, titanium oxide, cerium oxide, or tin oxide, or barium sulfate, and performing a baking treatment at 150° C. or higher. A resin layer obtained by cross-linking a cationic polymer with a cross-linking agent may be further formed on the corrosion-resistant layer. Examples of the cationic polymer include polyethyleneimine, an ionic polymer complex composed of a polymer having polyethyleneimine and carboxylic acid, a primary amine-grafted acrylic resin obtained by graft-polymerizing a primary amine to an acrylic backbone, polyallylamine or a derivative thereof, and aminophenol. As these cationic polymers, only one type may be used, or two or more types may be used in combination. Examples of cross-linking agents include compounds having at least one functional group selected from the group consisting of isocyanate groups, glycidyl groups, carboxyl groups, and oxazoline groups, and silane coupling agents. As these cross-linking agents, only one type may be used, or two or more types may be used in combination.

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

The amount of the acid-resistant film formed on the surface of the metal layer 3 in the chemical conversion treatment is not particularly limited. For example, in the case of performing the above-mentioned chromate treatment, the chromic acid compound is about 0.5 mg to about 50 mg, preferably about 1.0 mg to about 40 mg in terms of chromium, the phosphorus compound is about 0.5 mg to about 50 mg, preferably about 1.0 mg to about 40 mg, and the aminated phenolic polymer is about 1 mg per 1 m ² of the surface of the metal layer 3. It is desired to be contained in a ratio of to about 200 mg, preferably about 5.0 mg to 150 mg.

Chemical conversion treatment is performed by applying a solution containing a compound used for forming an acid-resistant film to the surface of a metal layer by a bar coating method, a roll coating method, a gravure coating method, an immersion method, or the like, and then heating the metal layer to a temperature of about 70°C to 200°C. In addition, before the chemical conversion treatment is applied to the metal layer, the metal layer may be previously subjected to degreasing treatment by an alkali immersion method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method, or the like. By performing the degreasing treatment in this manner, it becomes possible to perform the chemical conversion treatment on the surface of the metal layer more efficiently.

[Heat-fusible resin layer 4]
In the battery packaging material of the present invention, the heat-fusible resin layer 4 corresponds to the innermost layer, and is a layer that seals the battery element by heat-bonding the heat-fusible resin layers to each other when the battery is assembled.

The resin component used for the heat-fusible resin layer 4 is not particularly limited as long as it can be heat-fusible, and examples thereof include polyolefins, cyclic polyolefins, carboxylic acid-modified polyolefins, and carboxylic acid-modified cyclic polyolefins.

Specific examples of the polyolefin include polyethylenes such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene; homopolypropylene, block copolymers of polypropylene (e.g., block copolymers of propylene and ethylene), polypropylenes such as random copolymers of polypropylene (e.g., random copolymers of propylene and ethylene); terpolymers of ethylene-butene-propylene; Among these polyolefins, polyethylene and polypropylene are preferred.

The cyclic polyolefin is a copolymer of an olefin and a cyclic monomer. Examples of the olefin, which is a constituent monomer of the cyclic polyolefin, include ethylene, propylene, 4-methyl-1-pentene, styrene, butadiene, isoprene, and the like. Examples of cyclic monomers constituting the cyclic polyolefin include cyclic alkenes such as norbornene; specific examples thereof include cyclic dienes such as cyclopentadiene, dicyclopentadiene, cyclohexadiene and norbornadiene. Among these polyolefins, cyclic alkenes are preferred, and norbornene is more preferred.

The carboxylic acid-modified polyolefin is a polymer modified by block polymerization or graft polymerization of the polyolefin with a carboxylic acid. Carboxylic acids used for modification include, for example, maleic acid, acrylic acid, itaconic acid, crotonic acid, maleic anhydride, and itaconic anhydride.

The carboxylic acid-modified cyclic polyolefin is a polymer obtained by copolymerizing a part of the monomers constituting the cyclic polyolefin in place of an α,β-unsaturated carboxylic acid or its anhydride, or by block-polymerizing or graft-polymerizing an α,β-unsaturated carboxylic acid or its anhydride to a cyclic polyolefin. The carboxylic acid-modified cyclic polyolefin is the same as described above. The carboxylic acid used for modification is the same as those used for modification of the acid-modified cycloolefin copolymer.

Among these resin components, carboxylic acid-modified polyolefin is preferred; carboxylic acid-modified polypropylene is more preferred.

The heat-fusible resin layer 4 may be formed of one resin component alone, or may be formed of a blend polymer in which two or more resin components are combined. Further, the heat-fusible resin layer 4 may be composed of only one layer, or may be composed of two or more layers of the same or different resin components.

Moreover, the heat-fusible resin layer 4 may contain a lubricant or the like as necessary. When the heat-fusible resin layer 4 contains a lubricant, the moldability of the battery packaging material can be enhanced. The lubricant is not particularly limited, and known slip agents can be used. The slip agents may be used singly or in combination of two or more. The content of the slip agent in the heat-fusible resin layer 4 is not particularly limited, and is preferably about 0.01% by mass to 0.2% by mass, more preferably about 0.05% by mass to 0.15% by mass, from the viewpoint of improving the moldability and insulating properties of the electronic packaging material.

The thickness of the heat-fusible resin layer 4 can be selected as appropriate, and is about 10 μm to 100 μm, preferably about 15 μm to 50 μm.

[Adhesion layer 5]
In the battery packaging material of the present invention, the adhesive layer 5 is a layer optionally provided between the metal layer 3 and the heat-fusible resin layer 4 in order to firmly bond them.

The adhesive layer 5 is made of a resin capable of bonding the metal layer 3 and the heat-fusible resin layer 4 together. As the resin used to form the adhesive layer 5, the same adhesives as those exemplified for the adhesive layer 2 can be used in terms of the adhesive mechanism, the types of adhesive components, and the like. As the resin used to form the adhesive layer 5, polyolefin resins such as the polyolefins, cyclic polyolefins, carboxylic acid-modified polyolefins, and carboxylic acid-modified cyclic polyolefins exemplified for the heat-sealable resin layer 4 can also be used. From the viewpoint of excellent adhesion between the metal layer 3 and the heat-fusible resin layer 4, the polyolefin is preferably a carboxylic acid-modified polyolefin, and particularly preferably a carboxylic acid-modified polypropylene.

Furthermore, from the viewpoint of making the battery packaging material thinner and having excellent shape stability after molding, 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, the same carboxylic acid-modified polyolefin and carboxylic acid-modified cyclic polyolefin exemplified for the heat-sealable resin layer 4 can be preferably exemplified.

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

The epoxy-based curing agent is not particularly limited as long as it is a compound having at least one epoxy group. Examples of epoxy-based curing agents include epoxy resins such as bisphenol A diglycidyl ether, modified bisphenol A diglycidyl ether, novolac 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 polyfunctional isocyanate curing agents include isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), polymers and nurates thereof, mixtures thereof and copolymers with other polymers.

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 curing agent, a polycarbodiimide compound having at least two carbodiimide groups is preferred.

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

From the viewpoint of enhancing the adhesion between the metal layer 3 and the heat-fusible resin layer 4 by the adhesive layer 5, the curing agent may be composed of two or more kinds of compounds.

The content of the curing agent in the resin composition forming the adhesive layer 5 is preferably in the range of 0.1% by mass to 50% by mass, more preferably in the range of 0.1% by mass to 30% by mass, and even more preferably in the range of 0.1% by mass 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 using the adhesive exemplified for the adhesive layer 2, it is preferably 2 μm to 10 μm, more preferably 2 μm to 5 μm. In the case of using the resin exemplified for the heat-fusible resin layer 4, the thickness is preferably 2 μm to 50 μm, more preferably 10 μm to 40 μm. In the case of a cured product of an acid-modified polyolefin and a curing agent, the thickness is preferably 30 μm, more preferably 0.1 μm to 20 μm, still more preferably 0.5 μm 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 battery packaging material of the present invention, a surface coating layer (not shown) may be provided on the substrate layer 1 (the side opposite to the metal layer 3 of the substrate layer 1) as necessary for the purpose of improving design, electrolyte resistance, abrasion resistance, moldability, and the like. The surface coating layer is the outermost layer when the battery is assembled.

The surface coating layer can be formed of, for example, polyvinylidene chloride, polyester resin, urethane resin, acrylic resin, epoxy resin, or the like. Among these, the surface coating layer is preferably formed from a two-liquid curing resin. Examples of the two-component curable resin that forms 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, the surface coating layer may contain a matting agent.

Matting agents include, for example, fine particles having a particle size of about 0.5 nm to 5 μm. The material of the matting agent is not particularly limited, and examples thereof include metals, metal oxides, inorganic substances, organic substances and the like. The shape of the matting agent is also not particularly limited, and examples thereof include spherical, fibrous, plate-like, amorphous, balloon-like, and the like. Specific examples of matting agents include talc, silica, graphite, kaolin, montmorilloid, montmorillonite, synthetic mica, hydrotalcite, silica gel, zeolite, aluminum hydroxide, magnesium hydroxide, zinc oxide, magnesium oxide, aluminum oxide, neodymium 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 melting point nylon, cross-linked. Acrylic, crosslinked styrene, crosslinked polyethylene, benzoguanamine, gold, aluminum, copper, nickel and the like. These matting agents may be used singly or in combination of two or more. Among these matting agents, silica, barium sulfate, and titanium oxide are preferred from the viewpoint of dispersion stability, cost, and the like. In addition, the matting agent may be subjected to various surface treatments such as insulation treatment and high-dispersion treatment.

The method of forming the surface coating layer is not particularly limited, but for example, a method of coating one surface of the substrate layer 1 with a two-liquid curing resin that forms the surface coating layer can be used. When a matting agent is added, the matting agent may be added to the two-liquid curing resin, mixed, and then applied.

The thickness of the surface coating layer is not particularly limited as long as it exhibits the above function as a surface coating layer.

3. How to manufacture the packaging material for battery Regarding the manufacturing method of the packaging material for batteries in the first invention, as long as there is a laminated body with the prescribed composition layered, it is not particularly limited, at least 1, base material layer 1, metal layer 3, and thermal fusion resin layer 4 are obtained in this order. It is equipped with a metal layer 3, a thickness of 40 μm or less, and is formed by polyester as a base layer 1, and a thickness of 15 μm to 30 μm. The method for producing the battery packaging material according to the second aspect of the present invention is not particularly limited as long as a laminate having layers having a predetermined composition is obtained, and includes at least a step of obtaining a laminate comprising a substrate layer 1, a metal layer 3, and a heat-fusible resin layer 4 in this order. When the obtained laminate has a length of 100 mm and a width of 15 mm, it is pulled at a tensile speed of 50 mm/min at 25 ° C. and a tensile stress of 40 MPa is applied.
That is, the battery packaging material of the present invention can be produced by laminating each layer using the substrate layer 1 described in the section "2. Each layer forming the battery packaging material" as the substrate layer 1.

An example of the method for producing the battery packaging material of the present invention is as follows. First, a laminate (hereinafter also referred to as "laminate A") is formed, which includes a substrate layer 1, an adhesive layer 2, and a metal layer 3 in this order. Specifically, the laminate A can be formed by a dry lamination method in which the adhesive used for forming the adhesive layer 2 is applied on the base material layer 1 or on the metal layer 3 whose surface has been chemically treated as necessary by a coating method such as a gravure coating method or a roll coating method and dried, and then the metal layer 3 or the base material layer 1 is laminated to cure the adhesive layer 2.

Next, on the metal layer 3 of the laminate A, the heat-fusible resin layer 4 is laminated. When the heat-fusible resin layer 4 is directly laminated on the metal layer 3, the resin component constituting the heat-fusible resin layer 4 may be applied onto the metal layer 3 of the laminate A by a method such as gravure coating or roll coating. When the adhesive layer 5 is provided between the metal layer 3 and the heat-fusible resin layer 4, for example, (1) a method of laminating the adhesive layer 5 and the heat-fusible resin layer 4 on the metal layer 3 of the laminate A by co-extrusion (co-extrusion lamination method), (2) separately forming a laminate in which the adhesive layer 5 and the heat-fusible resin layer 4 are laminated, and laminating this on the metal layer 3 of the laminate A by a heat lamination method. A method in which an adhesive for forming an adhesive layer 5 is laminated on the layer 3 by an extrusion method, solution coating, drying at a high temperature, baking, or the like, and a heat-fusible resin layer 4 previously formed into a sheet is laminated on the adhesive layer 5 by a thermal lamination method. 4 (sandwich lamination method).

When the surface coating layer is provided, the surface coating layer is laminated on the surface of the substrate layer 1 opposite to the metal layer 3 . The surface coating layer can be formed, for example, by coating the surface of the substrate layer 1 with the above-described resin for forming the surface coating layer. The order of the step of laminating the metal layer 3 on the surface of the substrate layer 1 and the step of laminating the surface coating layer on the surface of the substrate layer 1 is not particularly limited. For example, after forming a surface coating layer on the surface of the substrate layer 1, the metal layer 3 may be formed on the surface of the substrate layer 1 opposite to the surface coating layer.

As described above, a laminate consisting of surface coating layer 1/adhesive layer 2/optionally chemically treated metal layer 3/optionally provided adhesive layer 5/heat-fusible resin layer 4 is formed. In order to strengthen the adhesiveness of the adhesive layer 2 and the optionally provided adhesive layer 5, the laminate may be subjected to heat treatment such as hot roll contact, hot air, or near or far infrared ray. Conditions for such heat treatment include, for example, 150° C. to 250° C. for 1 minute to 5 minutes.

In the battery packaging material of the present invention, each layer constituting the laminate may be subjected to surface activation treatment such as corona treatment, blasting treatment, oxidation treatment, and ozone treatment in order to improve or stabilize film formability, lamination processing, final product secondary processing (pouching, embossing) aptitude, etc., if necessary.

4. Use of Battery Packaging Material The battery packaging material of the present invention is used as a packaging material for hermetically housing battery elements such as a positive electrode, a negative electrode and an electrolyte.

Specifically, a battery element comprising at least a positive electrode, a negative electrode, and an electrolyte is covered with the battery packaging material of the present invention in a state in which the metal terminals connected to the positive electrode and the negative electrode protrude outward so that a flange portion (a region where the heat-fusible resin layers contact each other) can be formed on the periphery of the battery element, and the heat-fusible resin layers of the flange portion are heat-sealed to seal each other, thereby providing a battery using the battery packaging material. When the battery packaging material of the present invention is used to house a battery element, the sealant portion of the battery packaging material of the present invention is used on the inside (the surface in contact with the battery element).

The battery packaging material of the present invention may be used for either primary batteries or secondary batteries, preferably for secondary batteries. The type of secondary battery to which the battery packaging material of the present invention is applied is not particularly limited, and examples thereof include lithium ion batteries, lithium ion polymer batteries, lead-acid batteries, nickel-hydrogen batteries, nickel-cadmium batteries, nickel-iron batteries, nickel-zinc batteries, silver-zinc oxide batteries, metal-air batteries, polyvalent cation batteries, capacitors, capacitors, and the like. Among these secondary batteries, lithium-ion batteries and lithium-ion polymer batteries can be cited as suitable targets for application of the battery packaging material of the present invention.

EXAMPLES The present invention will be described in detail below with reference to examples and comparative examples. However, the present invention is not limited to the examples.

Examples 1A-5A and Comparative Examples 1A-6A
<Manufacturing of packaging materials for batteries>
A metal layer made of an aluminum foil having both sides subjected to a chemical conversion treatment was laminated on the substrate layer by a dry lamination method. Specifically, a two-component urethane adhesive (a polyol compound and an aromatic isocyanate compound) was applied to one surface of the aluminum foil to form an adhesive layer (3 μm thick) on the metal layer. Next, after laminating the adhesive layer on the metal layer and the substrate layer, aging treatment was performed at 40° C. for 24 hours to prepare a laminate of substrate layer/adhesive layer/metal layer. The chemical conversion treatment of the aluminum foil used as the metal layer was carried out by coating both sides of the aluminum foil with a treatment solution containing a phenolic resin, a fluorochromium compound, and phosphoric acid so that the coating amount of chromium was 10 mg/m ² (dry weight), and baking for 20 seconds at a film temperature of 180° C. or higher. Next, a two-component urethane adhesive (a polyol compound and an aromatic isocyanate compound) was applied onto the metal layer of the laminate to form an adhesive layer on the metal layer. Next, by attaching a random polypropylene film as a heat-fusible resin layer (innermost layer) onto the adhesive layer, the adhesive layer/heat-fusible resin layer was laminated on the metal layer to obtain each battery packaging material. The thicknesses of the substrate layer, metal layer, adhesive layer, and heat-fusible resin layer are shown in Table 1A. In Table 1A, PET/PET has a two-layer structure in which a polyethylene terephthalate layer is bonded via an adhesive layer (two-component urethane adhesive (polyol compound and aromatic isocyanate compound, thickness 3 μm). Similarly, PET/nylon has a two-layer structure in which a polyethylene terephthalate layer and a nylon layer are bonded via an adhesive layer (two-component urethane adhesive (polyol compound and aromatic isocyanate compound, thickness 3 μm). Base layer. has a two-layer structure, the thickness of the base layer does not include the thickness of the adhesive layer.

<Evaluation of formability>
Each battery packaging material obtained above was cut into a rectangle of 80 mm×120 mm to prepare a sample. Using a molding die (female die) having a diameter of 32 × 55 mm and a corresponding molding die (male die), the pressing surface pressure was 0.1 MPa to 0.2 MPa, and the molding depth was changed in 0.5 mm increments from a molding depth of 0.5 mm. For the samples after cold forming, the deepest forming depth at which wrinkles, pinholes, and cracks in the aluminum foil did not occur in all 20 samples was defined as the limit forming depth of the sample. Results are shown in Table 1A.

<Measurement of dielectric breakdown voltage>
The dielectric breakdown voltage of each battery packaging material obtained in Examples and Comparative Examples was measured by a method conforming to JIS C 2110-2 (test by direct voltage application). The measurement conditions were as follows: boost rate: 0.5 kV/s, ambient medium: air (23° C.), test electrode: φ25 cylinder/φ25 cylinder, test device: HAT-300-100RHO. Results are shown in Table 1A.

As shown in Table 1A, although the thickness of the metal layer is 40 μm or less and the thickness of the base layer is in the range of 15 μm to 30 μm, the battery packaging materials of Examples 1A to 5A have excellent moldability and insulation, although the base layer is made of PET. On the other hand, in Comparative Examples 1A to 6A, in which the thickness of the base material layer formed by PET was 9 μm to 12 μm, which is thinner than those of the Examples, moldability and insulating properties were inferior to those of Examples 1A to 5A.

Examples 1B-6B and Comparative Examples 1B-5B
<Manufacturing of packaging materials for batteries>
Each base material layer was prepared so that the displacement due to the later-described tension was the value shown in Table 1B. Next, on each substrate layer, a metal layer made of an aluminum foil having both sides subjected to chemical conversion treatment was laminated by a dry lamination method. Specifically, a two-component urethane adhesive (a polyol compound and an aromatic isocyanate compound) was applied to one surface of the aluminum foil to form an adhesive layer (3 μm thick) on the metal layer. Next, after laminating the adhesive layer on the metal layer and the substrate layer, aging treatment was performed at 40° C. for 24 hours to prepare a laminate of substrate layer/adhesive layer/metal layer. The chemical conversion treatment of the aluminum foil used as the metal layer was carried out by coating both sides of the aluminum foil with a treatment solution containing a phenolic resin, a fluorochromium compound, and phosphoric acid so that the coating amount of chromium was 10 mg/m ² (dry weight), and baking for 20 seconds at a film temperature of 180° C. or higher. A carboxylic acid-modified polypropylene (located on the metal layer side) as an adhesive layer and a random polypropylene film (innermost layer) as a heat-fusible resin layer were co-extruded, and the adhesive layer/heat-fusible resin layer was laminated on the metal layer to obtain each battery packaging material. A specific layer structure of the laminate is as shown in Table 1B. In Table 1B, PET/PET has a two-layer structure in which a polyethylene terephthalate layer is bonded via an adhesive layer (two-component urethane adhesive (polyol compound and aromatic isocyanate compound, thickness 3 μm). Similarly, PET/nylon has a two-layer structure in which a polyethylene terephthalate layer and a nylon layer are bonded via an adhesive layer (two-component urethane adhesive (polyol compound and aromatic isocyanate compound, thickness 3 μm). Base layer. has a two-layer structure, the thickness of the base layer does not include the thickness of the adhesive layer.

<Measurement of displacement due to tension of base material layer>
Each of the base layers used in the battery packaging materials of Examples 1B-5B and Comparative Examples 1B-6B was cut into a rectangle of 100 mm length×15 mm width to obtain a test piece. Each test piece was pulled at a tensile speed of 50 mm/min at 25° C., and a tensile stress of 15 MPa was measured. An autograph (SHIMAZU AUTOGRAPH AG-X Plus) was used for the pulling. Moreover, the distance between chucks was set to 30 mm. Results are shown in Table 1B. Graphs showing the relationship between tensile stress (MPa) and displacement (%) at this time are shown in FIGS.

<Measurement of displacement due to tension of battery packaging material>
Each of the battery packaging materials of Examples 1B-5B and Comparative Examples 1B-6B was cut into a rectangle having a length of 100 mm and a width of 15 mm to obtain a test piece. Each test piece was pulled at a tensile speed of 50 mm/min at 25° C., and a tensile stress of 40 MPa was measured. An autograph (SHIMAZU AUTOGRAPH AG-X Plus) was used for the pulling. Moreover, the distance between chucks was set to 30 mm. Results are shown in Table 1B. Graphs showing the relationship between tensile stress (MPa) and displacement (%) at this time are shown in FIGS.

<Evaluation of formability>
The moldability of the battery packaging materials of Examples 1B-6B and Comparative Examples 1B-5B was evaluated in the same manner as the evaluation of the moldability of the battery packaging materials of Examples 1A-5A and Comparative Examples 1A-6A. Results are shown in Table 1B.

<Evaluation of molded curl>
Examples 1B-6B and Comparative Examples 1B-5B were cut to prepare strips of 150 mm in length (z direction)×100 mm in width (x direction), which were used as test samples. Using a straight mold consisting of a rectangular male mold of 30 mm × 50 mm and a female mold with a clearance of 0.5 mm between the male mold, the test sample was placed on the female mold so that the heat-sealable resin layer 4 side was positioned on the male mold side, and the test sample was pressed with a pressing pressure (surface pressure) of 0.1 MPa so that the molding depth was 6 mm, and cold molded (pull-in one-step molding). The details of the molding positions are as shown in FIG. As shown in FIG. 5, the battery packaging material 10 was molded at a position where the shortest distance d between the rectangular molding portion M and the end portion P of the battery packaging material 10 was 25 mm. Next, the battery packaging material 10 after molding is placed on a horizontal surface 20 as shown in the figure, and the maximum value t of the distance in the vertical direction y from the horizontal surface 20 to the end P is the maximum height of the curled portion (molding curl (mm)). Results are shown in Table 1B.

表１Ｂにおいて、ＯＮｙはナイロン、ＰＥＴはポリエチレンテレフタレートである。ＰＥＴ／ＯＮｙは、ポリエチレンテレフタレートフィルムとナイロンフィルムの２層積層体であり、ＯＮｙが金属層側に位置している。なお、当該２層積層体の各層は、２液型ウレタン接着剤３μｍで接着している。基材層の厚みには、当該接着剤の厚みは含んでいない。ＡＬＭはアルミニウム合金箔を意味する。ＰＰはランダムポリプロピレン、ＰＰａは無水マレイン酸変性ポリプロピレンを意味する。

In Table 1B, ONy is nylon and PET is polyethylene terephthalate. PET/ONy is a two-layer laminate of polyethylene terephthalate film and nylon film, with ONy located on the metal layer side. Each layer of the two-layer laminate is adhered with a two-component urethane adhesive of 3 μm. The thickness of the base layer does not include the thickness of the adhesive. ALM means aluminum alloy foil. PP means random polypropylene and PPa means maleic anhydride-modified polypropylene.

In addition, in Table 1B, the numerical value in a parenthesis means thickness (micrometer). In addition, in the layer structure of the laminate, the adhesive layer (3 μm) when the substrate layer is a two-layer laminate and the adhesive layer (3 μm) located between the substrate layer and the metal layer are omitted.

1 base material layer 2 adhesive layer 3 metal layer 4 heat-fusible resin layer 5 adhesive layer 10 battery packaging material 20 horizontal surface M molded portion P end portion

Claims (2)

At least a laminate comprising a substrate layer containing polyester, a metal layer, and a heat-fusible resin layer having a thickness of 10 μm or more and 100 μm or less in this order,
The base material layer having a length of 100 mm and a width of 15 mm is pulled at a tensile speed of 50 mm / min at 25 ° C., and the displacement when a tensile stress of 15 MPa is applied is 5% or less,
A packaging material for a battery, wherein the laminate having a length of 100 mm and a width of 15 mm is stretched at a tensile speed of 50 mm/min at 25° C. and has a displacement of 5% or less when a tensile stress of 40 MPa is applied. A battery, wherein a battery element comprising at least a positive electrode, a negative electrode, and an electrolyte is housed in a package formed of the battery packaging material according to claim 1 .