JP2021122016A - Battery packaging material, manufacturing method thereof, and battery - Google Patents

Abstract

To provide a battery packaging material having excellent moldability and insulating properties.SOLUTION: A battery packaging material includes a laminate including at least a base material layer, a metal layer, and a heat-sealing resin layer in this order, and the thickness of the metal layer is 40 μm or less, the base material layer is made of polyester, and the thickness of the base material layer is 15 μm or more and 30 μm or less.SELECTED DRAWING: None

Description

The present invention relates to a packaging material for a battery, a method for producing the same, and a battery.

Conventionally, various types of batteries have been developed, but in all batteries, a packaging material is an indispensable member for sealing a battery element such as an electrode or an electrolyte. 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 for batteries, 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 / metal layer / heat-sealing resin layer is sequentially laminated. Has been proposed.

Further, in such a packaging material for a battery, a recess is generally formed by cold molding, and a battery element such as an electrode or an electrolytic solution is arranged in the space formed by the recess to form a heat-sealing resin. By heat-welding the layers to each other, a battery in which the battery element is housed inside the packaging material for the battery can be obtained. However, such a film-shaped packaging material is thinner than a metal packaging material, and has a drawback that pinholes and cracks are likely to occur during molding. When pinholes or cracks occur in the battery packaging material, the electrolytic solution penetrates into the metal layer to form metal precipitates, which may result in a short circuit. It is indispensable for the packaging material for batteries to have a property that pinholes are unlikely to occur during molding, that is, excellent moldability.

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

Japanese Unexamined Patent Publication No. 2008-288117

As described above, in the thin packaging material for batteries, a polyamide resin such as nylon is used as a base material layer to improve moldability.

On the other hand, as the packaging material for batteries becomes thinner, there is a problem that the insulating property of batteries also deteriorates. However, when a polyamide resin such as nylon is used, although the moldability is excellent, the insulating property may be insufficient.

In order to improve the insulating property of the thin battery packaging material, the present inventors have considered using polyester as the base material layer. However, polyester such as polyethylene terephthalate is inferior in moldability to nylon and the like. Therefore, when the base material layer is formed of polyester, for example, the thickness of the metal layer is made very thin (for example, 40 μm or less, and further. (35 μm or less), there was a problem that pinholes and the like were likely to occur in the metal layer during molding of the packaging material for batteries.

Under such circumstances, a main object of the present invention is at least excellent in a battery packaging material composed of a laminate having a base material layer made of polyester, a metal layer, and a heat-sealing resin layer in this order. Another object of the present invention is to provide a packaging material for a battery, which has excellent moldability, is less likely to cause pinholes and cracks during molding, and has excellent moldability.

Further, with the demand for miniaturization and thinning of batteries, further thinning of the packaging material for batteries is required. However, when the thickness of the packaging material for batteries becomes thin, the batteries are cold-molded. The peripheral edge of the recess formed in the packaging material is likely to curl. When curling occurs, it may hinder the accommodation of the battery element and the heat welding of the heat-weldable resin layer, thereby lowering the production efficiency of the battery.

As a result of the study by the present inventor, it has been clarified that such a curl problem 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 secondary batteries such as secondary batteries for automobiles have a problem that the influence of curl on the productivity of batteries is very large because of their large size. ..

Under such circumstances, the present invention has excellent moldability at least in a battery packaging material composed of a laminate having a base material layer, an adhesive layer, a metal layer, and a heat-sealing resin layer in this order. Further, it is also a main object to provide a packaging material for a battery in which curl after molding is effectively suppressed.

The present inventors have made diligent studies to solve the above problems. As a result, at least in a battery packaging material composed of a laminate having a base material layer made of polyester, a metal layer, and a heat-sealing resin layer in this order, a metal layer having a thickness of 40 μm or less is used. Nevertheless, by setting the thickness of the base material layer to 15 μm or more and 30 μm or less, it becomes a packaging material for batteries that not only has excellent insulating properties but also surprisingly excellent moldability. I found. Further, the present inventors have formed a laminate having at least a base material layer containing polyester, a metal layer, and a heat-sealing resin layer in this order, and the base material layer 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 the displacement when a tensile stress of 15 MPa is applied is 5% or less. The packaging material for batteries, which is pulled at a tensile speed of 50 mm / min and has a displacement of 5% or less when a tensile stress of 40 MPa is applied, has excellent moldability and effectively suppresses curling after molding. Found to be done. The present invention has been completed by further studies based on these findings.

That is, the present invention provides a battery packaging material and a battery according to the following aspects.
Item 1. It is composed of a laminate having at least a base material layer, a metal layer, and a heat-sealing resin layer in this order.
The thickness of the metal layer is 40 μm or less.
The base material layer is made of polyester and is made of polyester.
A packaging material for a battery in which the thickness of the base material layer is 15 μm or more and 30 μm or less.
Item 2. Item 2. The packaging material for a battery according to Item 1, wherein the thickness of the laminate is 140 μm or less.
Item 3. Item 2. The packaging material for a battery according to Item 1 or 2, wherein the base material layer is composed of one layer made of polyester.
Item 4. Item 2. The packaging material for a battery according to Item 1 or 2, wherein the base material layer is composed of a plurality of layers formed of polyester.
Item 5. Item 2. The packaging material for a battery according to any one of Items 1 to 4, wherein an acid-resistant film layer is provided on at least one surface of the metal layer.
Item 6. Item 2. The battery packaging material according to any one of Items 1 to 5, wherein the metal layer is aluminum foil.
Item 7. It is provided with a step of obtaining a laminate having at least a base material layer, a metal layer, and a heat-sealing resin layer in this order.
As the metal layer, a metal layer having a thickness of 40 μm or less is used.
A method for producing a packaging material for a battery, wherein the base material layer is made of polyester and has a thickness of 15 μm or more and 30 μm or less.
Item 8. It is composed of a laminate including at least a base material layer containing polyester, a metal layer, and a heat-sealing 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.
The laminated body having a length of 100 mm and a width of 15 mm is a packaging material for batteries, which 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 40 MPa is applied.
Item 9. A battery in which a battery element including at least a positive electrode, a negative electrode, and an electrolyte is housed in a packaging body 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 composed of a laminate having at least a base material layer made of polyester, a metal layer, and a heat-sealing resin layer in this order, the thickness of the metal layer is 40 μm or less. By setting the thickness of the base material layer to 15 μm or more and 30 μm or less in spite of using a material, it is possible to provide a packaging material for a battery which not only has excellent insulating properties but also excellent moldability. Can be done. Further, according to the present invention, it is possible to provide a packaging material for a battery which has excellent moldability and further suppresses curl after molding effectively.

It is a figure which shows an example of the cross-sectional structure of the packaging material for a battery of this invention. It is a figure which shows an example of the cross-sectional structure of the packaging material for a battery of this invention. It is a figure which shows an example of the cross-sectional structure of the packaging material for a battery 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. It is a graph which shows the relationship between the tensile stress (MPa) and the displacement (%) at the time of pulling about the test piece prepared from the base material layer of the battery packaging material of Examples 1B, 2B, 6B. It is a graph which shows the relationship between the tensile stress (MPa) and the displacement (%) at the time of pulling about the test piece prepared from the base material layer of the battery packaging material of Comparative Examples 1B, 4B and 5B. It is a graph which shows the relationship between the tensile stress (MPa) and the displacement (%) at the time of pulling about the test piece prepared from the battery packaging material of Examples 1B, 2B, 6B. It is a graph which shows the relationship between the tensile stress (MPa) and the displacement (%) at the time of pulling about the test piece made from the battery packaging material of Comparative Examples 1B, 4B and 5B.

The packaging material for a battery according to the first aspect of the present invention is composed of a laminate having at least a base material layer, a metal layer, and a heat-sealing resin layer in this order, and the thickness of the metal layer is 40 μm or less. The material layer is made of polyester, and the thickness of the base material layer is 15 μm or more and 30 μm or less. Since the packaging material for a battery according to the first aspect of the present invention has such a structure, it not only has excellent insulating properties but also excellent moldability. The packaging material for a battery according to a second aspect of the present invention comprises a laminate including at least a base material layer containing polyester, a metal layer, and a heat-sealing resin layer in this order, and has a length of 100 mm × The base material layer having 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, and the laminate having a length of 100 mm and a width of 15 mm. The body is characterized in that 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 battery packaging material of the second aspect of the present invention has such a structure, so that it has excellent moldability, and further, curl after molding is effectively suppressed. Hereinafter, the packaging material for a battery of the present invention will be described in detail.

In addition, in this specification, the display of "~" indicating a numerical range indicates that it is equal to or more than the numerical value attached to the left side thereof and less than or equal to the numerical value attached to the right side thereof. "" Means that it is X or more and Y or less.

1. 1. Laminated Structure of Battery Packaging Material As shown in FIG. 1, the battery packaging material is composed of a laminate having at least a base material layer 1, a metal layer 3, and a heat-sealing resin layer 4 in this order. In the battery packaging material of the present invention, the base material layer 1 is the outermost layer, and the heat-sealing resin layer 4 is the innermost layer. That is, when the battery is assembled, the heat-weldable resin layers 4 located on the periphery of the battery element are heat-welded to each other to seal the battery element, thereby sealing the battery element.

As shown in FIG. 2, in the packaging material for a battery of the present invention, an adhesive layer 2 is provided between the base material layer 1 and the metal layer 3 as needed for the purpose of enhancing their adhesiveness. You may. Further, as shown in FIG. 3, the packaging material for a battery of the present invention has an adhesive layer 5 between the metal layer 3 and the heat-sealing resin layer 4 for the purpose of enhancing their adhesiveness, if necessary. May be provided.

The thickness of the laminate constituting the packaging material for a battery of the present invention is not particularly limited, but is preferably 150 μm or less from the viewpoint of effectively suppressing deterioration of moldability and insulation while reducing the thickness. More preferably, it is about 110 μm to 145 μm. According to the first aspect of the present invention, even when the thickness of the laminate constituting the packaging material for a battery of the present invention is very thin, for example, 150 μm or less, the occurrence of pinholes and the like due to molding is effectively suppressed. Furthermore, the decrease in insulating property can be effectively suppressed. Further, according to the second aspect of the present invention, the generation of pinholes and the like due to molding is effectively suppressed, and further, the curl after molding is effectively suppressed. Therefore, the packaging material for a battery of the present invention can contribute to the improvement of the energy density of the battery and can also improve the productivity of the battery.

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

2. Each layer forming the packaging material for batteries [base material layer 1]
In the packaging material for batteries of the present invention, the base material layer 1 is a layer forming the outermost layer side. The base material layer 1 is made of polyester. As described above, in recent years, with the demand for miniaturization and thinning of batteries, further thinning of the packaging material for batteries is required. However, when the thickness of the battery packaging material is reduced, there is a problem that pinholes and cracks are likely to occur in the metal layer during molding. Furthermore, the insulating property tends to decrease.

On the other hand, in the first aspect of the present invention, the base material layer 1 is made of polyester, and the thickness of the base material layer 1 is in the range of 15 μm to 30 μm, so that the metal layer is formed. The occurrence of pinholes and cracks in No. 3 is effectively suppressed, and the insulating property is dramatically improved as compared with the case of forming with nylon or the like. When the packaging material for a battery is made thinner, the moldability is lowered. Therefore, conventionally, it has not been considered to use a resin having a poor moldability such as polyester alone for the base material layer. Therefore, it is surprising that by setting the thickness of the base material layer 1 formed of polyester within the above-mentioned specific range, it becomes a packaging material for batteries having excellent not only insulating properties but also moldability. rice field. Although the details of the mechanism by which excellent moldability is exhibited in the packaging material for batteries of the present invention are not clear despite the use of polyester, it can be considered as follows, for example. That is, in the present invention, since the thickness of the base material layer 1 formed of polyester is set within the above-mentioned specific range, the rapid elongation of the metal layer 3 during molding is appropriately controlled by the base material layer 1. As a result, it is considered that the occurrence of pinholes and the like in the metal layer 3 is suppressed.

Specific examples of the polyester include a copolymerized polyester containing polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, polycarbonate, and ethylene terephthalate as repeating units, and butylene terephthalate as repeating units. Examples thereof include copolymerized polyester as a main component. 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 / sevacate), polybutylene (terephthalate / decandicarboxylate), polybutylene naphthalate and the like. These polyesters may be used alone or in combination of two or more. Among these, polyethylene terephthalate has an advantage that it is excellent in electrolytic solution resistance and whitening or the like is unlikely to occur due to adhesion of the electrolytic solution, and is preferably used as a material for forming the base material layer 1.

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 while further reducing the thickness of the battery packaging material, excellent insulating properties and excellent moldability can be obtained. From the viewpoint of guaranteeing, more preferably about 20 μm to 25 μm. As will be described later, when the base material layer 1 is composed of a plurality of layers and each layer is adhered by an adhesive component such as an adhesive, the thickness of the adhesive component is 1 of the base material layer. Not included in the thickness. This is because the adhesive component does not substantially contribute to the improvement of the insulating property and moldability of the battery packaging material.

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

The base material layer 1 can be preferably composed of a polyester film, particularly preferably a polyethylene terephthalate film. When the base material 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 may be determined. Is the same as in the case of the adhesive layer 2 described later. The method of laminating two or more layers of polyester films is not particularly limited, and a known method can be adopted. Examples thereof include a dry laminating method and a sandwich laminating method, and a dry laminating method is preferable. When laminating by the dry laminating method, it is preferable to use a urethane-based adhesive as the adhesive layer. At this time, the thickness of the adhesive layer may be, for example, about 2 μm to 5 μm.

In the second aspect of the present invention, when the base material layer 1 has a length of 100 mm and a width of 15 mm, the base material layer 1 is pulled at a tensile speed of 50 mm / min at 25 ° C. and is displaced when a tensile stress of 15 MPa is applied. It is 5% or less. The displacement is preferably about 2% to 4%. In the second aspect of the present invention, when the displacement of the above-mentioned laminated body is within the above-mentioned predetermined range and the displacement of the base material layer 1 is 5% or less, pinholes and the like are generated by molding. It is effectively suppressed, and further, curl after molding is effectively suppressed. In the second aspect of the present invention, the thickness of the base material layer 1 is, for example, about 10 μm to 50 μm, preferably about 12 μm to 30 μm.

The base material layer 1 may have low friction in order to improve moldability. When the base material layer 1 is made to have low friction, the friction coefficient of the surface thereof is not particularly limited, and examples thereof include 1.0 or less. Examples of reducing the friction of the base material layer 1 include mat treatment, formation of a thin film layer of lubricant, and a combination thereof.

As the matting treatment, a matting agent is added to the base material layer 1 in advance to form irregularities on the surface, a transfer method by heating or pressurizing with an embossed roll, or a dry or wet blasting method or a file mechanically on the surface. There is a method of ruining. Examples of the matting agent include 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, and organic substances. The shape of the matting agent 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. Specific examples of the matting agent include talc, silica, graphite, kaolin, montmoriloid, montmorillonite, synthetic mica, hydrotalcite, silica gel, zeolite, aluminum hydroxide, magnesium hydroxide, zinc oxide, magnesium oxide, and aluminum oxide. , Neodium oxide, Antimon oxide, Titanium oxide, Cerium oxide, Calcium sulfate, Barium sulfate, Calcium carbonate, Calcium silicate, Lithium carbonate, Calcium benzoate, Calcium silicate, Magnesium stearate, Alumina, Carbon black, Carbon nanotubes, Examples thereof include refractory nylon, crosslinked acrylic, crosslinked styrene, crosslinked polyethylene, benzoguanamine, gold, aluminum, copper and nickel. These matting agents may be used alone or in combination of two or more. Among these matting agents, preferably silica, barium sulfate, and titanium oxide are mentioned from the viewpoint of dispersion stability and cost. Further, the matting agent may be subjected to various surface treatments such as an insulating treatment and a highly dispersible treatment on the surface.

The thin film layer of the lubricant can be formed by a method of precipitating 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. The lubricant is not particularly limited, but for example, amide lubricant, metal soap, hydrophilic silicone, silicone-grafted acrylic, silicone-grafted epoxy, silicone-grafted polyether, and silicone-grafted polyester as described later. , Block type silicone acrylic copolymer, polyglycerol modified silicone, paraffin and the like. These lubricants may be used alone or in combination of two or more.

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

The adhesive layer 2 is formed of an adhesive capable of adhering the base material layer 1 and the metal layer 3 to each other. The adhesive used to form the adhesive layer 2 may be a two-component curable adhesive or a one-component curable adhesive. Further, the adhesive mechanism used for forming the adhesive layer 2 is not particularly limited, and may be any of chemical reaction type, solvent volatilization type, heat melting type, thermal pressure type and the like.

Specific examples of the adhesive component 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-based adhesives; Polyurethane-based adhesives; Epoxy resins; Phenolic resin-based resins; Polyethylene-based resins such as nylon 6, nylon 66, nylon 12, and copolymerized polyamides; polyolefins, carboxylic acid-modified polyolefins, metal-modified polyolefins, etc. Polyolefin resin, Polyvinyl acetate resin; Cellulose adhesive; (Meta) acrylic resin; Polyimide resin; Amino resin such as urea resin and 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 2 is not particularly limited as long as it functions as an adhesive layer, and examples thereof include about 1 μm to 10 μm, preferably about 2 μm to 5 μm.

[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 preventing water vapor, oxygen, light, etc. from entering the inside of the battery. Specific examples of the metal constituting the metal layer 3 include aluminum, stainless steel, titanium, and the like, preferably aluminum. The metal layer 3 can be formed by a metal foil, metal vapor deposition, or the like, and is preferably formed of a metal foil, more preferably of an aluminum foil. From the viewpoint of preventing the formation of wrinkles and pinholes in the metal layer 3 during the manufacture of packaging materials for batteries, for example, annealed aluminum (JIS H4160 A8021HO, JIS H4160 A8079HO, JIS H4000: It is more preferable to form it with a soft aluminum foil such as 2014 A8021P-O, JIS H4000: 2014 A8079P-O).

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 moldability and insulating properties while further reducing the thickness of the battery packaging material, the thickness of the metal layer 3 can be more preferably 35 μm or less, still 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 such as water vapor, but may be, for example, about 10 μm to 50 μm, preferably about 10 μm to 40 μm. can.

Further, it is preferable that the metal layer 3 is provided with an acid-resistant film layer formed by chemical conversion treatment on at least one surface, preferably both sides, 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 a metal layer. The chemical conversion treatment includes chromate chromate using a chromic acid compound such as chromium nitrate, chromium fluoride, chromium sulfate, chromium acetate, chromium oxalate, chromium diphosphate, acetylacetate chromate, chromium chloride, and chromium potassium sulfate. Treatment; Phosphate chromate treatment using phosphoric acid compounds such as sodium phosphate, potassium phosphate, ammonium phosphate, polyphosphoric acid; aminoated phenol having repeating units represented by the following general formulas (1) to (4) Chromate treatment using a polymer and the like can be mentioned. In the amination phenol polymer, the repeating units 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. In addition, R ¹ and R ² represent a hydroxyl group, an alkyl group, or a hydroxyalkyl group, respectively, which are the same or different. 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 linear or branched alkyl groups having 1 to 4 carbon atoms such as tert-butyl groups. Examples of the hydroxyalkyl groups represented by X, R ¹ and R ² include a hydroxymethyl group, a 1-hydroxyethyl group, a 2-hydroxyethyl group, a 1-hydroxypropyl group, a 2-hydroxypropyl group and 3-. A linear or branched chain having 1 to 4 carbon atoms in which one hydroxy 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. An alkyl group 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, respectively. 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 amination phenol polymer having the repeating unit represented by the general formulas (1) to (4) is preferably, for example, 5 to 1,000,000, and more preferably about 1,000 to 20,000. preferable.

Further, as a chemical conversion treatment method for imparting corrosion resistance to the metal layer 3, a metal oxide such as aluminum oxide, titanium oxide, cerium oxide, or tin oxide or fine particles of barium sulfate are dispersed in phosphoric acid and coated. A method of forming a corrosion-resistant treatment layer on the surface of the metal layer 3 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 treatment 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 type may be used, or two or more types 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 treatments may be combined. 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 chromate treatment and chromate treatment in which a chromic acid 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 metal layer 3 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 metal layer 3.} About 0.5 mg to about 50 mg in terms of chromium, preferably about 1.0 mg to about 40 mg, the phosphorus compound is about 0.5 mg to about 50 mg in terms of phosphorus, preferably about 1.0 mg to about 40 mg, and the weight of aminoated phenol. It is desirable that the coalescence is contained in a proportion of about 1 mg to about 200 mg, preferably about 5.0 mg 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 metal 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 metal layer is 70. It is carried out by heating to about ° C. to 200 ° C. Further, before the metal layer is subjected to the chemical conversion treatment, the metal layer may be subjected to a degreasing treatment by an alkali 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 metal layer.

[Heat-sealing resin layer 4]
In the battery packaging material of the present invention, the heat-fusing resin layer 4 corresponds to the innermost layer, and is a layer in which the heat-fusing resin layers are heat-welded to each other during battery assembly to seal the battery element.

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

Specific examples of the polyolefin include low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, and other polyethylene; homopolypropylene, polypropylene block copolymer (for example, propylene and ethylene block copolymer), and polypropylene. Polypropylene such as random copolymers of propylene and ethylene (eg, random copolymers of propylene and ethylene); ethylene-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 that is a constituent monomer of the cyclic polyolefin include ethylene, propylene, 4-methyl-1-pentene, styrene, butadiene, isoprene, and the like. Can be mentioned. Examples of the cyclic monomer which is a constituent monomer of the cyclic polyolefin include cyclic alkenes such as norbornene; specific examples thereof include cyclic diene such as cyclopentadiene, dicyclopentadiene, cyclohexadiene, and norbornadiene. Among these polyolefins, cyclic alkene is preferable, and norbornene is more preferable.

The carboxylic acid-modified polyolefin is a polymer modified by block-polymerizing or graft-polymerizing the polyolefin with a carboxylic acid. Examples of the carboxylic acid used for denaturation include maleic acid, acrylic acid, itaconic acid, crotonic acid, maleic anhydride, itaconic anhydride and the like.

The carboxylic 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. -A polymer obtained by block-polymerizing or graft-polymerizing an unsaturated carboxylic acid or an anhydride thereof. The same applies to the cyclic polyolefin modified with carboxylic acid. The carboxylic acid used for the modification is the same as that used for the modification of the acid-modified cycloolefin copolymer.

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

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

Further, the heat-sealing resin layer 4 may contain a lubricant or the like, if necessary. When the heat-sealing resin layer 4 contains a lubricant, the moldability of the battery packaging material can be improved. The lubricant is not particularly limited, and a known slip agent can be used, and examples thereof include those exemplified in the above-mentioned base material layer 1. The slip agent may be used alone or in combination of two or more. The content of the slip agent in the heat-sealing resin layer 4 is not particularly limited, and is preferably 0.01% by mass to 0.2% by mass from the viewpoint of improving the moldability and insulating property of the electronic packaging material. The degree, more preferably about 0.05% by mass to 0.15% by mass.

The thickness of the heat-sealing resin layer 4 can be appropriately selected, and examples thereof include about 10 μm to 100 μm, preferably about 15 μm to 50 μm.

[Adhesive layer 5]
In the packaging material for batteries of the present invention, the adhesive layer 5 is a layer provided as necessary between the metal layer 3 and the heat-sealing resin layer 4 in order to firmly bond them.

The adhesive layer 5 is formed of a resin capable of adhering the metal layer 3 and the heat-sealing resin layer 4. As the resin used for forming the adhesive layer 5, the same adhesive mechanism and types of adhesive components as those exemplified in the adhesive layer 2 can be used. Further, as the resin used for forming the adhesive layer 5, polyolefin-based resins such as the polyolefin, cyclic polyolefin, carboxylic acid-modified polyolefin, and carboxylic acid-modified cyclic polyolefin exemplified in the above-mentioned heat-sealing resin layer 4 can also be used. .. From the viewpoint of excellent adhesion between the metal layer 3 and the heat-sealing resin layer 4, the polyolefin is preferably a carboxylic acid-modified polyolefin, and particularly preferably a carboxylic acid-modified polypropylene.

Further, from the viewpoint of making the battery packaging material excellent in shape stability after molding while reducing the thickness of the battery packaging material, the adhesive layer 5 is a curing of a resin composition containing an acid-modified polyolefin and a curing agent. It may be a thing. As the acid-modified polyolefin, preferably, the same ones as the carboxylic acid-modified polyolefin and the carboxylic acid-modified cyclic polyolefin exemplified in the heat-sealing resin layer 4 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, and an oxazoline-based curing agent.

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 metal layer 3 and the heat-sealing resin layer 4 by the adhesive layer 5.

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, and more preferably in the range of 0.1% by mass to 30% by mass. It is preferably in the range of 0.1% by mass to 10% by mass, more preferably.

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 2 is used, it is preferably 2 μm to 10 μm, more preferably 2 μm to 5 μm. Can be mentioned. When the resin exemplified in the heat-sealing resin layer 4 is used, it is preferably 2 μm to 50 μm, and more preferably 10 μm to 40 μm. When it is a cured product of the acid-modified polyolefin and the curing agent, it is preferably 30 μm, more preferably 0.1 μm to 20 μm, and further 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 packaging material for a battery of the present invention, for the purpose of improving designability, electrolytic solution resistance, scratch resistance, moldability, etc., if necessary, on the base material layer 1 (the metal layer of the base material layer 1). A surface coating layer (not shown) may be provided on the side opposite to 3), if necessary. The surface coating layer is a layer located at the outermost layer when the battery is assembled.

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. Moreover, you may mix the matting agent in the surface coating layer.

Examples of the matting agent include 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, and organic substances. The shape of the matting agent 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. Specific examples of the matting agent include talc, silica, graphite, kaolin, montmoriloid, montmorillonite, synthetic mica, hydrotalcite, silica gel, zeolite, aluminum hydroxide, magnesium hydroxide, zinc oxide, magnesium oxide, and aluminum oxide. , Neodium oxide, Antimon oxide, Titanium oxide, Cerium oxide, Calcium sulfate, Barium sulfate, Calcium carbonate, Calcium silicate, Lithium carbonate, Calcium benzoate, Calcium silicate, Magnesium stearate, Alumina, Carbon black, Carbon nanotubes, Examples thereof include refractory nylon, crosslinked acrylic, crosslinked styrene, crosslinked polyethylene, benzoguanamine, gold, aluminum, copper and nickel. These matting agents may be used alone or in combination of two or more. Among these matting agents, preferably silica, barium sulfate, and titanium oxide are mentioned from the viewpoint of dispersion stability and cost. Further, the matting agent may be subjected to various surface treatments such as an insulating 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 on one surface of the base material layer 1. When the matting agent is blended, the matting agent 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 μm to 10 μm, preferably about 1 μm to 5 μm.

3. 3. Method for Producing Packaging Material for Batteries The method for producing a packaging material for batteries according to the first aspect of the present invention is not particularly limited as long as a laminate in which each layer having a predetermined composition is laminated can be obtained, and at least a base material is used. A step of obtaining a laminate having a layer 1, a metal layer 3, and a heat-sealing resin layer 4 in this order is provided. A metal layer 3 having a thickness of 40 μm or less is used, and a base material layer 1 is made of polyester. The one having a thickness of 15 μm to 30 μm is used. The method for producing the packaging material for a battery according to the second aspect of the present invention is not particularly limited as long as a laminated body in which each layer having a predetermined composition is laminated can be obtained, and at least the base material layer 1 and the metal layer are not limited. A step of obtaining a laminate having the heat-sealing resin layer 4 and the heat-sealing resin layer 4 in this order is provided, and the base material layer having a length of 100 mm and a width of 15 mm as the base material layer 1 is tensioned at 25 ° C. When the laminate is pulled at a speed of 50 mm / min and the displacement when a tensile stress of 15 MPa is applied is 5% or less, and the obtained laminate is 100 mm in length × 15 mm in width, the tensile speed is 25 ° C. It is pulled at 50 mm / min and the displacement when a tensile stress of 40 MPa is applied is set to 5% or less.
That is, the battery packaging material of the present invention is produced by laminating each layer using the base material layer 1 described in the column of "2. Each layer forming the battery packaging material" as the base material layer 1. be able to.

An example of the method for producing the packaging material for a battery of the present invention is as follows. First, a laminate having the base material layer 1, the adhesive layer 2, and the metal layer 3 in this order (hereinafter, may be referred to as “laminate A”) is formed. Specifically, the laminate A is formed by applying an adhesive used for forming the adhesive layer 2 on the base material layer 1 or, if necessary, on the metal layer 3 whose surface has been chemically converted, by a gravure coating method. It can be carried out by a dry laminating method in which the metal layer 3 or the base material layer 1 is laminated and the adhesive layer 2 is cured after being coated and dried by a coating method such as a roll coating method.

Next, the heat-sealing resin layer 4 is laminated on the metal layer 3 of the laminated body A. When the heat-sealing resin layer 4 is directly laminated on the metal layer 3, the resin components constituting the heat-sealing resin layer 4 are coated on the metal layer 3 of the laminated body A by a gravure coating method or a roll coating method. It may be applied by a method such as. When the adhesive layer 5 is provided between the metal layer 3 and the heat-sealing resin layer 4, for example, (1) the adhesive layer 5 and the heat-sealing resin layer are placed on the metal layer 3 of the laminated body A. A method of laminating 4 by co-extruding (co-extrusion lamination method), (2) Separately, a laminated body in which the adhesive layer 5 and the heat-sealing resin layer 4 are laminated is formed, and this is formed into a metal layer of the laminated body A. By a method of laminating on 3 by a thermal lamination method, (3) a method of extruding an adhesive for forming an adhesive layer 5 on the metal layer 3 of the laminated body A, a solution-coated method of drying at a high temperature, and a method of baking. A method of laminating and laminating a heat-sealing resin layer 4 which has been laminated in advance on the adhesive layer 5 in the form of a sheet by a thermal lamination method. A method of laminating the laminate A and the heat-sealing resin layer 4 via the adhesive layer 5 while pouring the melted adhesive layer 5 between the heat-sealing resin layer 4 (sandwich laminating method) and the like. Can be mentioned.

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

As described above, a surface coating layer provided as needed / a base material layer 1 / an adhesive layer 2 / a metal layer whose surface has been chemically treated as needed 3 / an adhesive layer 5 provided as needed A laminate composed of the heat-sealing resin layer 4 is formed, and in order to strengthen the adhesiveness of the adhesive layer 2 and the adhesive layer 5 provided as needed, a hot roll contact type and a hot air type are further formed. , Near or far infrared type, etc. may be subjected to heat treatment. Examples of the conditions for such heat treatment include 1 minute to 5 minutes at 150 ° C. to 250 ° C.

In the packaging material for batteries of the present invention, each layer constituting the laminated body improves or stabilizes film forming property, laminating process, suitability for secondary processing (pouching, embossing) of the final product, etc., as necessary. Therefore, surface activation treatment such as corona treatment, blast treatment, oxidation treatment, and ozone treatment may be performed.

4. Applications of Battery Packaging Materials The battery packaging materials of the present invention are used as packaging materials for sealing and accommodating battery elements such as positive electrodes, negative electrodes, and electrolytes.

Specifically, a battery element having at least a positive electrode, a negative electrode, and an electrolyte is used in the battery packaging material of the present invention, with metal terminals connected to each of the positive electrode and the negative electrode projecting outward. A battery is formed by covering the peripheral edge of an element so that a flange portion (a region where the heat-sealing resin layers come into contact with each other) can be formed, and heat-sealing and sealing the heat-sealing resin layers of the flange portion. Batteries using packaging materials for use are provided. When the battery element is housed using the battery packaging material of the present invention, the sealant portion of the battery packaging material of the present invention is used so as to be inside (the surface in contact with the battery element).

The packaging material for a battery 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 secondary battery to which the packaging material for a battery of the present invention is applied is not particularly limited, and for example, a lithium ion battery, a lithium ion polymer battery, a lead livestock battery, a nickel / hydrogen livestock battery, and a nickel / cadmium livestock battery. , Nickel / iron livestock battery, nickel / zinc livestock battery, silver oxide / zinc livestock battery, metal air battery, polyvalent cation battery, condenser, capacitor and the like. Among these secondary batteries, lithium ion batteries and lithium ion polymer batteries can be mentioned as suitable application targets of the battery packaging material of the present invention.

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.

Example 1A-5A and Comparative Example 1A-6A
<Manufacturing of packaging materials for batteries>
A metal layer made of aluminum foil having undergone chemical conversion treatment on both sides was laminated on the base material layer by a dry laminating method. Specifically, a two-component urethane adhesive (polyol compound and aromatic isocyanate compound) was applied to one surface of the aluminum foil to form an adhesive layer (thickness 3 μm) on the metal layer. Next, after laminating the adhesive layer and the base material layer on the metal layer, an aging treatment was carried out at 40 ° C. for 24 hours to prepare a laminated body of the base material layer / adhesive layer / metal layer. In the chemical conversion treatment of the aluminum foil used as the metal layer, a treatment liquid consisting of a phenol resin, a chromium fluoride compound, and phosphoric acid was roll-coated so that the ^{amount of chromium applied was 10 mg / m 2 (dry weight).} It was applied to both sides of the aluminum foil by the method and baked for 20 seconds under the condition that the film temperature was 180 ° C. or higher. Next, a two-component urethane adhesive (polyol compound and aromatic isocyanate compound) was applied onto the metal layer of the laminate to form an adhesive layer on the metal layer. Next, by pasting a random polypropylene film as a heat-sealing resin layer on the (innermost layer) adhesive layer, the adhesive layer / heat-sealing resin layer is laminated on the metal layer, and packaging for each battery. Obtained the material. The thicknesses of the base material layer, the metal layer, the adhesive layer, and the heat-sealing resin layer are as shown in Table 1A, respectively. 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, in PET / nylon, 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) 2). It has a layer structure. When the base material layer has a two-layer structure, the thickness of the base material layer does not include the thickness of the adhesive layer.

<Evaluation of moldability>
Each battery packaging material obtained above was cut into a rectangle of 80 mm × 120 mm to prepare a sample. This sample is molded to 0.5 mm at a pressing surface pressure of 0.1 MPa to 0.2 MPa using a molding die (female mold) having a diameter of 32 x 55 mm and a corresponding molding die (male mold). Cold molding was performed on each of 20 samples by changing the molding depth in 0.5 mm increments from the depth. For the sample after cold forming, the deepest forming depth at which no wrinkles or pinholes or cracks were generated in all 20 samples was defined as the limit forming depth of the sample. The results are shown in Table 1A.

<Measurement of dielectric breakdown voltage>
The breakdown voltage of each battery packaging material obtained in Examples and Comparative Examples was measured by a method in accordance with JIS C 2110-2 (test by applying DC voltage). The measurement conditions were a boosting speed: 0.5 kV / s, an ambient medium: the atmosphere (23 ° C.), a test electrode: φ25 cylinder / φ25 cylinder, and a test device: HAT-300-100RHO. The results are shown in Table 1A.

As shown in Table 1A, the thickness of the base material layer is in the range of 15 μm to 30 μm even though the thickness of the metal layer is 40 μm or less and the base material layer is formed by PET. It can be seen that the battery packaging materials of Examples 1A to 5A are excellent in moldability and insulation. 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 was thinner than in Examples, the moldability and the insulating property were inferior to those in Examples 1A to 5A. ..

Example 1B-6B and Comparative Example 1B-5B
<Manufacturing of packaging materials for batteries>
Each base material layer having a displacement due to tension, which will be described later, having the values shown in Table 1B was prepared. Next, a metal layer made of aluminum foil having undergone chemical conversion treatment on both sides was laminated on each base material layer by a dry laminating method. Specifically, a two-component urethane adhesive (polyol compound and aromatic isocyanate compound) was applied to one surface of the aluminum foil to form an adhesive layer (thickness 3 μm) on the metal layer. Next, after laminating the adhesive layer and the base material layer on the metal layer, an aging treatment was carried out at 40 ° C. for 24 hours to prepare a laminated body of the base material layer / adhesive layer / metal layer. In the chemical conversion treatment of the aluminum foil used as the metal layer, a treatment liquid consisting of a phenol resin, a chromium fluoride compound, and phosphoric acid was roll-coated so that the ^{amount of chromium applied was 10 mg / m 2 (dry weight).} It was applied to both sides of the aluminum foil by the method and baked for 20 seconds under the condition that the film temperature was 180 ° C. or higher. A carboxylic acid-modified polypropylene (arranged on the metal layer side) as an adhesive layer and a random polypropylene film as a heat-sealing resin layer (innermost layer) are extruded together, and an adhesive layer / heat-sealing resin layer is formed on the metal layer. The layers were laminated to obtain packaging materials for each battery. The specific layer structure of the laminated body 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, in PET / nylon, 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) 2). It has a layer structure. When the base material layer has a two-layer structure, the thickness of the base material layer does not include the thickness of the adhesive layer.

<Measurement of displacement due to tension of the base material layer>
Each base material layer used for the battery packaging material of Example 1B-5B and Comparative Example 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 15 MPa was measured. An autograph (SHIMAZU AUTOGRAPH AG-X Plus) was used for pulling. The distance between the chucks was set to 30 mm. The results are shown in Table 1B. Further, with respect to the test pieces prepared from the base material layers used in the battery packaging materials of Examples 1B, 2B, 6B and Comparative Examples 1B, 4B, 5B, the relationship between the tensile stress (MPa) and the displacement (%) at this time. The graphs showing the above are shown in FIGS. 6 and 7.

<Measurement of displacement due to pulling of battery packaging material>
The battery packaging materials of Example 1B-5B and Comparative Example 1B-6B were cut into rectangles having a length of 100 mm and a width of 15 mm, respectively, to obtain test pieces. 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 pulling. The distance between the chucks was set to 30 mm. The results are shown in Table 1B. Further, FIG. 8 is a graph showing the relationship between the tensile stress (MPa) and the displacement (%) of the test pieces prepared from the battery packaging materials of Examples 1B, 2B, 6B and Comparative Examples 1B, 4B, 5B. , 9 shows.

<Evaluation of moldability>
The moldability of the battery packaging materials of Examples 1B-6B and Comparative Example 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. .. The results are shown in Table 1B.

<Evaluation of molding curl>
Example 1B-6B and Comparative Example 1B-5B were cut to prepare strips having a length (z direction) of 150 mm and a width (x direction) of 100 mm, which were used as test samples. A straight mold consisting of a 30 mm × 50 mm rectangular male mold and a female mold with a clearance of 0.5 mm between the male mold is used, and the heat-sealing resin layer 4 side is located on the male mold side on the female mold. The test sample was placed therein, and the test sample was pressed with a pressing pressure (surface pressure) of 0.1 MPa so as to have a molding depth of 6 mm, and cold forming (pull-in one-stage forming) was performed. The details of the molding position are as shown in FIG. As shown in FIG. 5, molding was performed at a position where the shortest distance d = 25 mm between the rectangular molded portion M and the end portion P of the battery packaging material 10. Next, the molded battery packaging material 10 is placed on the horizontal plane 20 as shown in the figure, and the maximum height of the portion where the maximum value t of the distance y in the vertical direction from the horizontal plane 20 to the end portion P is curled. (Molding curl (mm)). The 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 a polyethylene terephthalate film and a nylon film, and ONy is located on the metal layer side. Each layer of the two-layer laminate is bonded with a two-component urethane adhesive of 3 μm. The thickness of the base material 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 Table 1B, the numerical value in parentheses means the thickness (μm). Further, in the layer structure of the laminated body, the adhesive layer (3 μm) when the base material layer is a two-layer laminated body and the adhesive layer (3 μm) located between the base material layer and the metal layer. The description is omitted.

1 Base material layer 2 Adhesive layer 3 Metal layer 4 Heat-sealing resin layer 5 Adhesive layer 10 Battery packaging material 20 Horizontal surface M Molded part P end

Claims (9)

It is composed of a laminate having at least a base material layer, a metal layer, and a heat-sealing resin layer in this order.
The thickness of the metal layer is 40 μm or less.
The base material layer is made of polyester and is made of polyester.
A packaging material for a battery in which the thickness of the base material layer is 15 μm or more and 30 μm or less. The packaging material for a battery according to claim 1, wherein the thickness of the laminate is 140 μm or less. The packaging material for a battery according to claim 1 or 2, wherein the base material layer is composed of one layer made of polyester. The packaging material for a battery according to claim 1 or 2, wherein the base material layer is composed of a plurality of layers formed of polyester. The packaging material for a battery according to any one of claims 1 to 4, wherein an acid-resistant film layer is provided on at least one surface of the metal layer. The battery packaging material according to any one of claims 1 to 5, wherein the metal layer is aluminum foil. It is provided with a step of obtaining a laminate having at least a base material layer, a metal layer, and a heat-sealing resin layer in this order.
As the metal layer, a metal layer having a thickness of 40 μm or less is used.
A method for producing a packaging material for a battery, wherein the base material layer is made of polyester and has a thickness of 15 μm or more and 30 μm or less. It is composed of a laminate including at least a base material layer containing polyester, a metal layer, and a heat-sealing 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.
The laminated body having a length of 100 mm and a width of 15 mm is a packaging material for batteries, which 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 40 MPa is applied. A battery in which a battery element including at least a positive electrode, a negative electrode, and an electrolyte is housed in a packaging body formed of the battery packaging material according to any one of claims 1 to 8.

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