Battery packaging material and battery

Abstract

Provided is a battery packaging material having excellent moldability and comprising a laminate having at least a base material layer, a barrier layer, and a heat-fusible resin layer in this order. This battery packaging material is composed of a laminate having at least a base layer, a barrier layer, and a heat-fusible resin layer in this order, the laminate having a thickness of 100 [mu] m or less, and the sum (X + Y) of the rupture energy (X) and the rupture energy (Y) of the laminate being 200 J or more, the fracture energy (X) is the fracture energy per 1 m unit width calculated on the basis of a curve of a measurement load (N / 15 mm)-displacement amount measured when a tensile test is performed under the following test conditions: the fracture energy (X) is the fracture energy in one direction perpendicular to the thickness direction of the laminate; the rupture energy Y is the rupture energy in the other direction that is the direction perpendicular to both the one direction and the thickness direction of the laminate. (test conditions) the test speed is 50mm / min, the width of the test piece is 15mm, and the distance between the punctuations is 30mm.

Description

[0001] (This application is a divisional application of application No. 201880050377.4, with the invention name of "Battery packaging material and battery", filed on August 2, 2018) Technical Field

[0003] The present invention relates to a battery packaging material and a battery. Background Art

[0004] Currently, various types of batteries have been developed. In all batteries, a packaging material is an indispensable component for sealing battery elements such as electrodes and electrolytes. In the prior art, as a battery packaging material, a metal packaging material is mostly used.

[0005] On the other hand, in recent years, with the high-performance development of electric vehicles, hybrid electric vehicles, computers, cameras, mobile phones, etc., for batteries, it is required to have various shapes, and it is also required to be thinner and lighter. However, the metal battery packaging materials mostly used in the prior art are difficult to cope with the diversification of shapes, and there is also a drawback that there is a limit to weight reduction.

[0006] Therefore, in recent years, as a battery packaging material that is easy to process into various shapes and can achieve thinning and weight reduction, a film-like laminate in which a base material layer / a barrier layer / a heat-sealable resin layer are laminated in this order has been proposed (for example, refer to Patent Document 1).

[0007] In such a battery packaging material, a recess is usually formed by cold rolling, battery elements such as electrodes and electrolytes are disposed in the space formed by the recess, and the heat-sealable resin layers are heat-sealed to each other, thereby obtaining a battery in which the battery elements are accommodated inside the battery packaging material. However, such a film-like packaging material is thinner than a metal packaging material, and has a drawback that pinholes or cracks are likely to occur during molding. When pinholes or cracks occur in the battery packaging material, the electrolyte penetrates into the barrier layer to form metal precipitates, and as a result, a short circuit may occur. Therefore, the film-like battery packaging material must have a property of not easily generating pinholes during molding, that is, excellent moldability.

[0008] Prior Art Documents

[0009] Patent Documents

[0010] Patent Document 1: Japanese Patent Laid-Open No. 2008-287971 Summary of the Invention

[0011] Technical Problems to be Solved by the Invention

[0012] In recent years, with the requirements for miniaturization and thinning of batteries, further thinning of the packaging materials for batteries has also been demanded. However, when the thickness of the battery packaging material composed of a film-like laminate is extremely thin, for example, 100 μm or less, there are problems such as cracks or pinholes being easily generated during molding and it being difficult to impart high formability.

[0013] The main object of the present invention is to provide a battery packaging material excellent in formability, which is composed of a laminate having at least a substrate layer, a barrier layer, and a heat-sealable resin layer in this order.

[0014] Technical means for solving technical problems

[0015] In order to solve the above technical problems, the inventors of the present invention conducted in-depth research. As a result, it was found that in a battery packaging material composed of a laminate having at least a substrate layer, a barrier layer, and a heat-sealable resin layer in this order, when the thickness of the laminate is 100 μm or less and the sum X + Y of the fracture energy X and the fracture energy Y of the laminate is 200 J or more, a battery packaging material excellent in formability can be obtained. Here, the above fracture energy is the fracture energy per unit width of 1 m calculated from the curve of "measured load (N / 15 mm) - displacement amount" measured when a tensile test is conducted under the following test conditions. The above fracture energy X is the fracture energy in one direction perpendicular to the thickness direction of the laminate, and the above fracture energy Y is the fracture energy in the other direction perpendicular to both the above one direction and the thickness direction of the laminate. The present invention was completed by further repeated research based on these insights.

[0016] (Test conditions)

[0017] Test speed: 50 mm / min

[0018] Width of test piece: 15 mm

[0019] Distance between punctuation marks: 30 mm

[0020] The length of the test piece is set to 100 mm. However, when only a test piece with a length less than 100 mm can be prepared, as long as the distance between punctuation marks can be ensured and both ends of the test piece can be grasped during measurement, the test piece as long as possible (as close to 100 mm as possible) is used as the measurement object.

[0021] That is, the present invention provides a battery packaging material and a battery in the manner disclosed below.

[0022] Item 1. A battery packaging material, which is composed of a laminate having at least a substrate layer, a barrier layer, and a heat-sealable resin layer in this order,

[0023] The thickness of the above laminate is 100 μm or less.

[0024] The sum X + Y of the fracture energy X and the fracture energy Y of the above laminate is 200 J or more. Here, the above fracture energy is the fracture energy per unit width of 1 m calculated from the curve of the measured load (N / 15 mm) - displacement amount measured when performing a tensile test under the following test conditions. The above fracture energy X is the fracture energy in one direction perpendicular to the thickness direction of the above laminate, and the above fracture energy Y is the fracture energy in the other direction perpendicular to both the above one direction and the thickness direction of the above laminate.

[0025] (Test conditions)

[0026] Test speed: 50 mm / min

[0027] Width of test piece: 15 mm

[0028] Distance between punctuation marks: 30 mm

[0029] Item 2. The battery packaging material according to Item 1, wherein the above one direction is the MD of the above laminate, and the above other direction is the TD of the above laminate.

[0030] Item 3. The battery packaging material according to Item 1 or 2, wherein the puncture strength of the above laminate measured from the above base material layer side according to the method specified in JIS Z1707:1995 is 15 N or more.

[0031] Item 4. The battery packaging material according to any one of Items 1 to 3, wherein an adhesive layer is provided between the above base material layer and the above barrier layer.

[0032] Item 5. The battery packaging material according to Item 4, wherein the above adhesive layer contains a colorant.

[0033] Item 6. The battery packaging material according to Item 4 or 5, wherein a colored layer is provided between the above base material layer and the above adhesive layer.

[0034] Item 7. The battery packaging material according to any one of Items 1 to 6, wherein a surface covering layer is provided on the side of the above base material layer opposite to the above barrier layer.

[0035] Item 8. A battery, in which a battery element having 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 7.

[0036] Effect of the invention

[0037] According to the present invention, in a battery packaging material composed of a laminate having at least a substrate layer, a barrier layer, and a heat-sealable resin layer in this order, although the thickness of the laminate is 100 μm or less and very thin, a battery packaging material with excellent formability can be provided by the sum X + Y of the fracture energy X and the fracture energy Y of the laminate being 200 J or more. Here, the above-mentioned fracture energy is the fracture energy per unit width of 1 m calculated from the curve of "measured load (N / 15 mm) - displacement amount" measured during a tensile test under the above-mentioned test conditions. The above-mentioned fracture energy X is the fracture energy in one direction perpendicular to the thickness direction of the laminate, and the above-mentioned fracture energy Y is the fracture energy in the other direction perpendicular to both the above-mentioned one direction and the thickness direction of the laminate. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a diagram showing an example of the cross-sectional structure of the battery packaging material of the present invention.

[0039] Figure 2 It is a diagram showing an example of the cross-sectional structure of the battery packaging material of the present invention.

[0040] Figure 3 It is a diagram showing an example of the cross-sectional structure of the battery packaging material of the present invention.

[0041] Figure 4 It is a diagram showing an example of the cross-sectional structure of the battery packaging material of the present invention.

[0042] Figure 5 It is a diagram showing an example of the cross-sectional structure of the battery packaging material of the present invention.

[0043] Figure 6 It is a curve (MD) of measured load (N / 15 mm) - displacement amount obtained from a tensile test of the battery packaging material of Example 5.

[0044] Figure 7 It is a schematic diagram showing a part where the data of the measured load (N / 15 mm) - displacement amount curve is integrated.

[0045] Figure 8 It is a schematic diagram for explaining an evaluation method of curl caused by the forming of the battery packaging material.

[0046] Figure 9 It is a schematic diagram for explaining an evaluation method of curl caused by the forming of the battery packaging material.

[0047] Figure 10 It is a schematic diagram of the barrier layer of the test sample after forming in the example. DETAILED DESCRIPTION OF THE INVENTION

[0048] The packaging material for a battery of the present invention is characterized by being composed of a laminate having at least a base material layer, a barrier layer, and a heat-sealable resin layer in this order. The thickness of the laminate is 100 μm or less, and the sum X + Y of the fracture energy X and the fracture energy Y of the laminate is 200 J or more. Here, the above-mentioned fracture energy is the fracture energy per unit width of 1 m calculated from the curve of the measured load (N / 15 mm) - displacement amount when a tensile test is performed under the following test conditions. The above-mentioned fracture energy X is the fracture energy in one direction perpendicular to the thickness direction of the laminate, and the above-mentioned fracture energy Y is the fracture energy in the other direction perpendicular to both the one direction and the thickness direction of the laminate. The packaging material for a battery of the present invention will be described in detail below.

[0049] (Test conditions)

[0050] Test speed: 50 mm / min

[0051] Width of test piece: 15 mm

[0052] Distance between punctuation marks: 30 mm

[0053] Here, in this specification, the numerical range indicated by "~" means "above" and "below". For example, an expression such as 2~15 mm means 2 mm or more and 15 mm or less.

[0054] 1. Laminated Structure and Physical Properties of Packaging Material for Battery

[0055] The packaging material for a battery of the present invention is, for example, as Figures 1 - 5 shown, composed of a laminate having at least a base material layer 1, a barrier layer 3, and a heat-sealable resin layer 4 in this order. In the packaging material for a battery of the present invention, the base material layer 1 becomes the outermost layer side, and the heat-sealable resin layer 4 becomes the innermost layer. That is, when assembling a battery, the heat-sealable resin layers 4 located at the periphery of the battery element are heat-sealed to each other to seal the battery element, thereby encapsulating the battery element.

[0056] The packaging material for a battery of the present invention is, for example, as Figures 2 - 5 shown. Between the base material layer 1 and the barrier layer 3, an adhesive layer 2 can be provided as needed for the purpose of improving their adhesiveness. In addition, the packaging material for a battery of the present invention is, for example, as Figures 3 - 5 shown. Between the barrier layer 3 and the heat-sealable resin layer 4, an adhesive layer 5 can be provided as needed for the purpose of improving their adhesiveness. In addition, as Figure 4 and Figure 5 shown, a surface covering layer 6 can be provided on the outside of the base material layer 1 (the side opposite to the heat-sealable resin layer 4) as needed. And, as Figure 5As shown, a coloring layer 7 may be provided between the base material layer 1 and the adhesive layer 2 as needed.

[0057] The thickness of the laminate constituting the battery packaging material of the present invention is 100 μm or less, and the sum X + Y of the fracture energy X and the fracture energy Y of the laminate is 200 J or more. Here, the above-mentioned fracture energy is the fracture energy per unit width of 1 m calculated from the curve of "measured load (N / 15 mm) - displacement amount" measured during a tensile test under the above test conditions. The above-mentioned fracture energy X is the fracture energy in one direction perpendicular to the thickness direction of the laminate (i.e., the lamination direction of the laminate), and the above-mentioned fracture energy Y is the fracture energy in the other direction perpendicular to both the above one direction and the thickness direction of the laminate (i.e., the other direction is perpendicular to the above one direction and is also perpendicular to the thickness direction of the laminate). From the viewpoint of being able to reduce the thickness of the battery packaging material and further improve the formability, it is preferable that the above one direction is the MD (Machine Direction) of the laminate, and the above other direction is the TD (Transverse Direction) of the laminate. That is, regarding the fracture energy per unit width of 1 m calculated from the curve of "measured load (N / 15 mm) - displacement amount" measured during a tensile test under the above test conditions, it is preferable that the sum X + Y of the fracture energy X in the MD as the flow direction of the laminate and the fracture energy Y in the TD as the perpendicular direction is 200 J or more. Here, in the present invention, the tensile test means a test of tensile properties.

[0058] Further, from the viewpoints of reducing the thickness of the packaging material for the battery thinning and improving the formability, regarding the total X + Y of the above-mentioned fracture energies, preferable upper limits may include about 700 J or less, about 500 J or less, about 495 J or less, about 450 J or less, about 445 J or less, about 400 J or less, less than about 400 J, about 380 J or less, and the lower limit preferably includes about 250 J or more, more preferably about 300 J or more. As the range of the total X + Y of the above-mentioned fracture energies, preferably include about 200 to 700 J, about 200 to 500 J, about 200 to 495 J, about 200 to 450 J, about 200 to 445 J, about 200 to 400 J, about 200 J or more and less than about 400 J, about 200 to 380 J, about 250 to 700 J, about 250 to 500 J, about 250 to 495 J, about 250 to 450 J, about 250 to 445 J, about 250 to 400 J, about 250 J or more and less than about 400 J, about 250 to 380 J, about 300 to 700 J, about 300 to 500 J, about 300 to 495 J, about 300 to 450 J, about 300 to 445 J, about 300 to 400 J, about 300 J or more and less than about 400 J, about 300 to 380 J.

[0059] As a method for making the total X + Y of the above-mentioned breaking energy be 200 J or more, it is possible to adjust the materials and thicknesses of the base material layer, the barrier layer, and the heat-sealable resin layer that constitute the laminate. As the layer that contributes the most to the magnitude of the breaking energy, the base material layer can be cited. As the raw material for constituting the base material layer, the materials described later can be used, and during the manufacturing process of the base material layer, for example, the type of film-forming method or the conditions during film formation (such as film-forming temperature, draw ratio, cooling temperature, cooling rate, heat setting temperature after stretching) can be appropriately adjusted. As the film-forming method, for example, the T-die method, the calendering method, the tubular method, etc. can be cited. In addition, in order to make the total X + Y of the breaking energy be 200 J or more, it is preferable to heat the laminate after laminating each layer under the conditions of an appropriate temperature and an appropriate time. By adopting an appropriate temperature and time, damage to the laminate, especially to the base material layer, can be suppressed, and the adhesion of each layer can be improved. As the upper limit of the heating temperature in the heating process, it is preferably about 185 °C or less, more preferably about 180 °C or less, and further preferably 178 °C or less. As the lower limit of the heating temperature, it is preferably 150 °C or more, more preferably 160 °C or more, and further preferably 165 °C or more. As the preferable range of the heating temperature in the heating process, 150 - 185 °C or so, 150 - 180 °C or so, 150 - 178 °C or so, 160 - 185 °C or so, 160 - 180 °C or so, 160 - 178 °C or so, 165 - 185 °C or so, 160 - 180 °C or so, 160 - 178 °C or so can be cited. In addition, as the upper limit of the heating time in the heating process, it is preferably 30 minutes or less, more preferably 15 minutes or less, and further preferably 10 minutes or less. As the lower limit, it is preferably 0.1 minute or more, more preferably 0.5 minute or more, and further preferably 1 minute or more. The heating temperature and the heating time in the heating process are preferably combined from these.

[0060] Among them, in the battery packaging material, for the barrier layer described later, the MD and TD during its manufacturing process can usually be distinguished. For example, when the barrier layer is composed of an aluminum foil, linear stripes called so-called calendering marks are formed on the surface of the aluminum foil in the rolling direction (RD, Rolling Direction) of the aluminum foil. Since the calendering marks extend along the rolling direction, by observing the surface of the aluminum foil, the rolling direction of the aluminum foil can be known. In addition, during the manufacturing process of the laminate, generally, the MD of the laminate coincides with the RD of the aluminum foil. Therefore, by observing the surface of the aluminum foil of the laminate and determining the rolling direction (RD) of the aluminum foil, the MD of the laminate can be determined. In addition, since the TD of the laminate is the direction perpendicular to the MD of the laminate, the TD of the laminate can also be determined.

[0061] In the present invention, the breaking energies X and Y per unit width of 1 m in the above-mentioned one direction and the above-mentioned other direction of the laminate constituting the battery packaging material are calculated as follows: For the above-mentioned one direction and the above-mentioned other direction of the laminate, data of the measured load (N / 15 mm) - displacement curve during the tensile test under the above-mentioned test conditions are respectively obtained, and this data is saved in the csv document format. Using spreadsheet software (Excel (registered trademark) of Microsoft Corporation), it is calculated by integrating this data until the laminate breaks. At this time, using this spreadsheet software, it is converted (divided by 0.015) into the breaking energy per 1 m width of each battery packaging material and calculated. Then, the breaking energy per unit width of 1 m in one direction is summed with the breaking energies X and Y per unit width of 1 m in the other direction. Herein, when the laminate breaks, it means when the test piece breaks. And, five battery packaging materials to be measured are respectively prepared. For example, the average value of three values obtained by removing the maximum value and the minimum value from the breaking energy values of the five samples is used as the breaking energy of the laminate. In the case where five samples cannot be prepared, it is preferable to use the average value obtained by measuring with the number of samples that can be measured. In addition, in the tensile test, a commercially available device can be used as the tensile testing machine.

[0062] In addition, from the viewpoints of thinning the thickness of the battery packaging material and improving formability, the puncture strength of the laminate constituting the battery packaging material of the present invention, measured from the substrate layer 1 side according to the method specified in JIS Z1707:1995, preferably has a lower limit of about 15 N or more, more preferably about 18 N or more, and further preferably about 19 N or more, and an upper limit preferably of about 30 N or less, more preferably about 25 N or less, and further preferably about 22 N or less. In addition, as the range of this puncture strength, preferably about 15 - 30 N, about 15 - 25 N, about 18 - 30 N, about 18 - 25 N, about 18 - 22 N, about 19 - 30 N, about 19 - 25 N, about 19 - 22 N are exemplified. From the viewpoint of suppressing curling caused by the forming of the battery packaging material, this puncture strength is preferably about 22 N or less. The method for measuring the puncture strength of the laminate is as follows.

[0063] <Puncture Strength of Laminate>

[0064] The puncture strength of the laminate constituting the battery packaging material from the substrate layer side is measured by the method specified in JIS Z1707:1995. Specifically, in a measurement environment of 23 ± 2°C and a relative humidity of (50 ± 5)%, the test piece is fixed using a stage with a diameter of 115 mm having an opening of 15 mm in the center and a pressing plate, and a semicircular needle with a diameter of 1.0 mm and a tip shape radius of 0.5 mm is pierced through at a speed of 50 ± 5 mm per minute, and the maximum stress until the needle penetrates is measured. The number of test pieces is 5, and their average value is obtained. In addition, when the number of test pieces is insufficient for measuring 5, the number that can be measured is measured, and its average value is obtained.

[0065] In addition, the wetting tension on the substrate layer 1 side of the laminate constituting the battery packaging material of the present invention is not particularly limited. From the viewpoints of reducing the thickness of the battery packaging material and improving formability, about 30 to 60 mN / m is preferably cited. As a method for adjusting the wetting tension, a method of adjusting the amount of lubricant present on the surface of the substrate layer 1 side or a method of performing a surface treatment (corona discharge treatment, etc.) on the surface of the substrate layer 1 side can be cited. The method for measuring the wetting tension is as described below.

[0066] <Measurement of wetting tension>

[0067] Using the wetting reagent specified in the JIS standard, the wetting tension on the substrate layer side of the laminate constituting the battery packaging material is measured. The test method follows JIS K6768:1999. Using the mixed liquid for wetting tension test, the reagent contained in the cotton swab is applied in a line about 6 cm 2 long on the surface of the substrate layer side of the laminate constituting the battery packaging material, and the determination is made based on whether the liquid film breaks after 2 seconds. When the liquid film does not break, the next mixed liquid with a higher surface tension is used, and when it breaks, the next mixed liquid with a lower surface tension is used. This operation is repeated, and the mixed liquid that wets the surface of the test piece in 2 seconds is selected. Among them, the measurement of the wetting tension is carried out in an environment of 23°C and a relative humidity of 50%.

[0068] In addition, regarding the forming depth at which the thickness of the barrier layer 3 described later of the battery packaging material of the present invention reaches 20 μm (that is, the forming depth when the thickness of the barrier layer 3 of the battery packaging material of the present invention reaches 20 μm when the battery packaging material is subjected to forming), the lower limit is preferably 4.5 mm or more, more preferably 5.0 mm or more, and the upper limit is preferably 10.0 mm or less, more preferably 8.0 mm or less. Preferred ranges can be cited as about 4.5 to 10.0 mm, about 4.5 to 8.0 mm, about 5.0 to 10.0 mm, about 5.0 to 8.0 mm. Specifically, this forming depth is the value measured by the method described in the examples.

[0069] In addition, regarding the ultimate forming depth of the packaging material for batteries of the present invention, the lower limit is preferably 4.0 mm or more, more preferably 5.5 mm or more, and the upper limit is preferably 12.0 mm or less, more preferably 10.0 mm or less. Preferred ranges may include around 4.0 to 12.0 mm, around 4.0 to 10.0 mm, around 5.5 to 12.0 mm, and around 5.5 to 10.0 mm. Specifically, the ultimate forming depth is a value measured by the method described in the examples.

[0070] Regarding the thickness of the laminate constituting the packaging material for batteries of the present invention, there is no particular limitation as long as it is 100 μm or less. From the viewpoints of ensuring excellent formability and reducing the thickness as much as possible, the upper limit is preferably about 95 μm or less, more preferably about 89 μm or less, and further preferably about 75 μm or less. The lower limit is preferably about 35 μm or more, more preferably about 45 μm or more. Also, as the range of the thickness of the laminate, preferred ranges may include around 35 to 100 μm, around 35 to 95 μm, around 45 to 95 μm, around 35 to 89 μm, around 45 to 89 μm, around 35 to 75 μm, and around 45 to 75 μm. Although the thickness of the laminate constituting the packaging material for batteries of the present invention is as thin as 100 μm or less, according to the present invention, excellent formability can still be exhibited. Therefore, the packaging material for batteries of the present invention helps to improve the energy density of the battery.

[0071] 2. Layers Forming the Packaging Material for Battery

[0072] [Base material layer 1]

[0073] In the packaging material for batteries of the present invention, the base material layer 1 is the layer on the outermost layer side. Regarding the raw material for forming the base material layer 1, there is no particular limitation as long as it is a material having insulation properties. As the raw material for forming the base material layer 1, for example, polyester, polyamide, epoxy resin, acrylic resin, fluororesin, polyurethane, silicone resin, phenolic resin, polyetherimide, polyimide, polycarbonate, and their mixtures or copolymers, etc. can be cited.

[0074] As the polyester, specifically, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, copolyester with polyethylene terephthalate as the main repeating unit, copolyester with polybutylene terephthalate as the main repeating unit, etc. can be cited. In addition, as the copolyester with polyethylene terephthalate as the main repeating unit, specifically, the copolymer polyester polymerized with polyethylene terephthalate as the main repeating unit and ethylene glycol isophthalate (hereinafter abbreviated according to the writing of "poly(ethylene terephthalate / isophthalate) glycol"), poly(ethylene terephthalate / isophthalate) glycol, poly(ethylene terephthalate / adipic acid) glycol, poly(ethylene terephthalate / sodium sulfoisophthalate) glycol, poly(ethylene terephthalate / sodium isophthalate) glycol, poly(ethylene terephthalate / phenyl-dicarboxylic acid) glycol, poly(ethylene terephthalate / decane dicarboxylic acid) glycol, etc. can be cited. In addition, as the copolyester with polybutylene terephthalate as the main repeating unit, specifically, the copolymer polyester polymerized with polybutylene terephthalate as the main repeating unit and butylene glycol isophthalate (hereinafter abbreviated according to the writing of "poly(ethylene terephthalate / isophthalate) butylene glycol"), poly(ethylene terephthalate / adipic acid) butylene glycol, poly(ethylene terephthalate / sebacic acid) butylene glycol, poly(ethylene terephthalate / decane dicarboxylic acid) butylene glycol, polybutylene naphthalate, etc. can be cited. These polyesters can be used alone or in combination of two or more. The polyester has the advantages of excellent electrolyte resistance and difficulty in whitening due to the adhesion of the electrolyte, and is suitable as a raw material for forming the base material layer 1.

[0075] In addition, as the polyamide, specifically, aliphatic polyamides such as nylon 6, nylon 66, nylon 610, nylon 12, nylon 46, copolymer of nylon 6 and nylon 66, etc. can be cited; hexamethylenediamine-isophthalic acid-terephthalic acid copolyamide such as nylon 6I, nylon 6T, nylon 6IT, nylon 6I6T (I represents isophthalic acid, T represents terephthalic acid) containing structural units from terephthalic acid and / or isophthalic acid, poly(m-xylylene adipamide) (MXD6) and other aromatic-containing polyamides; alicyclic polyamides such as polyaminomethylcyclohexyl adipamide (PACM6); and polyamides obtained by copolymerizing lactam components and isocyanate components such as 4,4'-diphenylmethane-diisocyanate, polyester amide copolymers or polyether ester amide copolymers as copolymers of copolyamides and polyesters or polyalkylene ether diols; copolymers thereof, etc. These polyamides can be used alone or in combination of two or more. The drawn polyamide film has excellent drawability and can prevent the resin of the base material layer 1 from cracking and whitening during molding, and is suitable as a raw material for forming the base material layer 1.

[0076] The base material layer 1 can be formed of a resin film that has been uniaxially or biaxially stretched, or can be formed of an unstretched resin film. Among them, a resin film that has been uniaxially or biaxially stretched, especially a biaxially stretched resin film, has improved heat resistance due to orientation crystallization, and is thus suitable for use as the base material layer 1. In addition, the base material layer 1 can also be formed by coating the above-mentioned raw materials on the barrier layer 3.

[0077] Among these, as the resin film for forming the base material layer 1, nylon and polyester are preferably listed, biaxially stretched nylon and biaxially stretched polyester are more preferably listed, and biaxially stretched nylon is particularly preferably listed.

[0078] Regarding the base material layer 1, in order to improve the pinhole resistance and insulation when used as a battery package, at least one of a resin film and a coating of different raw materials can be laminated (multi-layer structured). Specifically, examples include a multi-layer structure formed by laminating a polyester film and a nylon film, a multi-layer structure formed by laminating multi-layer nylon films, a multi-layer structure formed by laminating multi-layer polyester films, etc. When the base material layer 1 is a multi-layer structure, it is preferably a laminate of a biaxially stretched nylon film and a biaxially stretched polyester film, a laminate formed by laminating multi-layer biaxially stretched nylon films, or a laminate formed by laminating multi-layer biaxially stretched polyester films. As a specific example, a laminate formed by laminating two layers of biaxially stretched nylon films is preferably used. In addition, since biaxially stretched polyester is not easily discolored when, for example, an electrolytic solution adheres to its surface, when the base material layer 1 is a multi-layer structure of a laminate of a biaxially stretched nylon film and a biaxially stretched polyester film, the base material layer 1 is preferably a laminate having biaxially stretched nylon and biaxially stretched polyester in that order from the barrier layer 3 side. When the base material layer 1 is made into a multi-layer structure, as the thickness of each layer, about 3 to 25 μm is preferably listed.

[0079] When the base material layer 1 is made into a multi-layer structure, the resin films can be bonded using an adhesive, or they can be directly laminated without using an adhesive. In the case of not using an adhesive for bonding, for example, methods of bonding in a thermally molten state such as co-extrusion method, sandwich lamination method, and thermal lamination method can be listed. In addition, when using an adhesive for bonding, the adhesive used can be a two-component curing type adhesive or a one-component curing type adhesive. Moreover, there is no particular limitation on the bonding mechanism of the adhesive, and any type such as chemical reaction type, solvent evaporation type, thermal melting type, hot pressing type, ultraviolet curing type, or electron beam curing type can be used. As a specific example of the adhesive, the same adhesives as those exemplified in the adhesive layer 2 can be listed. In addition, the thickness of the adhesive can be the same as that of the adhesive layer 2.

[0080] In the present invention, from the viewpoint of improving the formability of the packaging material for batteries, a lubricant is preferably adhered to the surface of the base material layer 1. The lubricant is not particularly limited, and amide-based lubricants are preferably cited. Specific examples of amide-based lubricants include saturated fatty acid amides, unsaturated fatty acid amides, substituted amides, hydroxymethyl amides, saturated fatty acid bisamides, unsaturated fatty acid bisamides, etc. Specific examples of saturated fatty acid amides include lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, hydroxystearic acid amide, etc. Specific examples of unsaturated fatty acid amides include oleic acid amide, erucic acid amide, etc. Specific examples of substituted amides include N-oleyl palmitic acid amide, N-stearyl stearic acid amide, N-stearyl oleic acid amide, N-oleyl stearic acid amide, N-stearyl erucic acid amide, etc. In addition, specific examples of hydroxymethyl amides include hydroxymethyl stearic acid amide, etc. Specific examples of saturated fatty acid bisamides include methylene bisstearic acid amide, ethylene bisdecanoic acid amide, ethylene dilauric acid amide, ethylene bisstearic acid amide, ethylene bis(hydroxystearic acid) amide, ethylene bisbehenic acid amide, hexamethylene bisstearic acid amide, hexamethylene bisbehenic acid amide, hexamethylene hydroxystearic acid amide, N,N'-distearyl adipic acid amide, N,N'-distearyl sebacic acid amide, etc. Specific examples of unsaturated fatty acid bisamides include ethylene bisoleic acid amide, ethylene biserucic acid amide, hexamethylene bisoleic acid amide, N,N'-dioleyl adipic acid amide, N,N'-dioleyl sebacic acid amide, etc. Specific examples of fatty acid ester amides include stearamide ethyl stearate, etc. In addition, specific examples of aromatic bisamides include m-xylylene bisstearic acid amide, m-xylylene bis(hydroxystearic acid) amide, N,N'-distearyl isophthalic acid amide, etc. The lubricant can be used alone as one kind, or two or more kinds can be used in combination.

[0081] Regarding the content of the lubricant in the base material layer 1, there is no particular limitation. From the viewpoints of improving the formability and insulation of the electronic packaging material, preferably about 0.01 to 0.2% by mass, more preferably about 0.05 to 0.15% by mass.

[0082] Regarding the thickness of the base material layer 1, from the perspective of reducing the thickness of the packaging material for the battery and producing a packaging material for the battery with excellent formability, as the lower limit, it is preferably about 8 μm or more, more preferably about 10 μm or more. As the upper limit, it is preferably about 25 μm or less, more preferably about 20 μm or less. Additionally, as the range of the thickness of the base material layer 1, it is preferably about 8 - 25 μm, about 8 - 20 μm, about 10 - 25 μm, or about 10 - 20 μm. Among them, in the present invention, when the base material layer 1 is a multilayer structure bonded by an adhesive, the thickness of the base material layer 1 does not include the thickness of the adhesive.

[0083] [Adhesive layer 2]

[0084] In the packaging material for the battery of the present invention, the adhesive layer 2 is a layer provided between the base material layer 1 and the barrier layer 3 to firmly bond them.

[0085] The adhesive layer 2 is formed of an adhesive capable of bonding the base material layer 1 and the barrier layer 3. The adhesive used to form the adhesive layer 2 can be a two-component curable adhesive or a one-component curable adhesive. Moreover, there is no particular limitation on the bonding mechanism of the adhesive used to form the adhesive layer 2, and it can be any type such as a chemical reaction type, a solvent evaporation type, a hot melt type, or a hot press type.

[0086] Specific examples of the adhesive components that can be used to form the adhesive layer 2 include polyester-based resins such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and copolyester; polyether-based adhesives; polyurethane-based adhesives; epoxy-based resins; phenolic-based resins; polyamide-based resins such as nylon 6, nylon 66, nylon 12, and copolyamide; polyolefin-based resins such as polyolefin, carboxylic acid-modified polyolefin, and metal-modified polyolefin, polyvinyl acetate-based resins; cellulose-based adhesives; (meth)acrylic-based resins; polyimide-based resins; polycarbonate; amino resins such as urea-formaldehyde resin and melamine resin; rubbers such as chloroprene rubber, nitrile rubber, and styrene-butadiene rubber; and silicone-based resins. These adhesive components can be used alone or in combination of two or more. Among these adhesive components, polyurethane-based adhesives are preferred.

[0087] Moreover, the adhesive layer 2 may contain a colorant. By the adhesive layer 2 containing a colorant, the packaging material for the battery can be colored. As the colorant, known colorants such as pigments and dyes can be used. And the colorant can be used alone or in a mixture of two or more.

[0088] For example, as specific examples of inorganic pigments, carbon black, titanium oxide, etc. are preferably listed. In addition, as specific examples of organic pigments, azo pigments, phthalocyanine pigments, polycyclic pigments, etc. are preferably listed. As azo pigments, soluble pigments such as Vulchow red and carmine 6C can be listed; insoluble azo pigments such as monoazo yellow, bisazo yellow, pyrazolone orange, pyrazolone red, and permanent red can be listed; as phthalocyanine pigments, copper phthalocyanine pigments, blue and green pigments as metal-free phthalocyanine pigments can be listed; as polycyclic pigments, dioxazine violet, quinacridone violet, etc. can be listed. In addition, as pigments, pearlescent pigments or fluorescent pigments, etc. can also be used.

[0089] Among the colorants, for example, when making the appearance of the battery packaging material black, carbon black is preferred.

[0090] There is no particular limitation on the average particle size of the pigment. For example, it can be about 0.05 to 5 μm, preferably about 0.08 to 2 μm. Among them, the average particle size of the pigment is the median diameter measured by a laser diffraction / scattering particle size distribution measuring device.

[0091] There is no particular limitation on the content of the pigment in the adhesive layer 2 as long as it can color the battery packaging material. For example, it can be about 5 to 60% by mass.

[0092] Regarding the thickness of the adhesive layer 2, as long as it can function as a layer for bonding, there is no particular limitation. For example, it can be about 1 to 10 μm, preferably about 2 to 5 μm.

[0093] [Coloring layer 7]

[0094] The coloring layer 7 is a layer provided between the substrate layer 1 and the adhesive layer 2 as needed. By providing the coloring layer 7, the battery packaging material can be colored.

[0095] The coloring layer 7 can be formed, for example, by coating an ink containing a colorant on the surface of the substrate layer 1. As the colorant, known colorants such as pigments and dyes can be used. In addition, only one kind of colorant can be used, or two or more kinds can be mixed and used.

[0096] As specific examples of the colorant contained in the coloring layer 7, the same colorants as those exemplified in the [Adhesive layer 2] column can be exemplified.

[0097] There is no particular limitation on the ink for forming the coloring layer 7, and known inks can be used. As specific examples of the ink, for example, inks containing a colorant, diamine, polyol, and a curing agent can be listed. Among them, as the solvent contained in the ink, known solvents can be used, such as toluene, etc.

[0098] The above diamine is not particularly limited. For example, ethylenediamine, dimer diamine, 2-hydroxyethyl ethylenediamine, 2-hydroxyethyl propanediamine, dicyclohexylmethane diamine, 2-hydroxyethyl propanediamine, etc. may be cited. Among them, as the above diamine, it is preferable to use one or more diamines selected from ethylenediamine, dimer diamine, 2-hydroxyethyl ethylenediamine, 2-hydroxyethyl propanediamine, and dicyclohexylmethane diamine.

[0099] The reaction rate of the diamine with the curing agent (such as isocyanate) is faster than that of the polyol, and curing can be achieved in a short time. That is, both the diamine and the polyol react with the curing agent to promote the crosslinking and curing of the ink.

[0100] The polyol is not particularly limited, and it is preferable to use one or more polyols selected from polyurethane-based polyols, polyester-based polyols, and polyether-based polyols.

[0101] The number average molecular weight of the polyol is preferably in the range of about 1000 to 8000. By being 1000 or more, the bonding strength after curing can be increased; and by being 8000 or less, the reaction rate with the curing agent can be accelerated.

[0102] The curing agent is not particularly limited. For example, isocyanate compounds, etc. may be cited. As the isocyanate compound, for example, various isocyanate compounds of aromatic series, aliphatic series, and alicyclic series can be used. As specific examples, toluene diisocyanate (TDI), diphenylmethane diisocyanate, hexamethylene diisocyanate (HDI), isophorone diisocyanate, etc. may be cited.

[0103] In the coloring layer 7, as the content of the colorant, as long as it can color the battery packaging material, there is no particular limitation. For example, about 5 to 60% by mass may be cited. For example, when the colorant is carbon black, the content of carbon black is preferably about 20 to 50% by mass. In addition, the total content of the above diamine, polyol, and curing agent is preferably about 40 to 85% by mass. And, relative to 100 parts by mass of the total amount of the colorant, diamine, and polyol, the curing agent is preferably about 2 to 20 parts by mass.

[0104] The thickness (after drying) of the coloring layer 7 is preferably about 1 to 4 μm. By being 1 μm or more, the transparency of the color tone of the coloring layer 7 will not remain, and the color and gloss of the barrier layer 3 can be sufficiently masked. And by being 4 μm or less, cracking of the coloring layer 7 part during molding can be sufficiently prevented.

[0105] The coloring layer 7 can be formed, for example, by coating an ink for forming the coloring layer 7 on the surface of the base material layer 1. As the coating method of the ink, for example, printing methods such as gravure printing method, or reverse roll coating method, lip die roll coating method, etc. may be cited.

[0106] [Barrier layer 3]

[0107] In the battery packaging material, the barrier layer 3 is a layer that has the function of improving the strength of the battery packaging material and preventing the intrusion of water vapor, oxygen, light, etc. into the battery interior. The barrier layer 3 is preferably a metal layer, that is, a layer formed of a metal. As the metal constituting the barrier layer 3, specifically, aluminum, stainless steel, titanium, etc. can be cited, and aluminum is preferably cited. The barrier layer 3 can be formed, for example, of a metal foil, a metal vapor deposition film, an inorganic oxide vapor deposition film, a carbon-containing inorganic oxide vapor deposition film, a film provided with these vapor deposition films, etc., preferably formed of a metal foil, and more preferably formed of an aluminum foil or a stainless steel foil.

[0108] When the barrier layer 3 is composed of an aluminum foil, the aluminum foil can be formed of an aluminum alloy. When manufacturing the battery packaging material, from the viewpoint of preventing wrinkles or pinholes from occurring in the barrier layer 3, the barrier layer is more preferably formed of, for example, soft aluminum foil such as annealed aluminum (JIS H4160:1994 A8021H-O, JIS H4160:1994 A8079H-O, JIS H4000:2014 A8021P-O, JIS H4000:2014 A8079P-O).

[0109] In addition, when the barrier layer 3 is composed of a stainless steel foil, it is preferable that the stainless steel foil is composed of austenitic stainless steel. Thereby, a battery packaging material having high puncture strength, excellent electrolyte resistance and formability can be obtained. As specific examples of austenitic stainless steel, SUS304, SUS301, SUS316L, etc. can be cited, and among these, SUS304 is particularly preferred. In addition, the stainless steel foil has improved ductility and better formability especially after cold rolling treatment. And after cold rolling, by performing heat treatment and annealing, the balance between the flow direction and the width direction becomes better and the formability is improved. In addition, in order to stabilize the effect of the chemical surface treatment described later, it is very important to add a surface cleaning process after rolling treatment or heat treatment. As the cleaning method, cleaning using an alkali or an acid, alkali electrolytic degreasing cleaning, etc. can be cited. And ultrasonic treatment or plasma treatment, etc. can also be used in combination. Alkali degreasing cleaning and alkali electrolytic degreasing are preferred. Thereby, the surface wettability is improved, the chemical surface treatment can be made uniform, and the content resistance is stabilized.

[0110] Regarding the thickness of the barrier layer 3, as long as it can function as a barrier layer for water vapor, etc., there is no particular limitation. For example, it is preferably about 50 μm or less, more preferably about 10 - 50 μm, and further preferably about 10 - 40 μm.

[0111] Further, with respect to the barrier layer 3, in order to stabilize adhesion, prevent dissolution or corrosion, etc., it is preferable to perform a chemical surface treatment on at least one surface, and more preferably on both surfaces. Here, the chemical surface treatment refers to a treatment for forming an acid-resistant film on the surface of the barrier layer. Examples of the chemical surface treatment include: chromate treatment using chromium compounds such as chromium nitrate, chromium fluoride, chromium sulfate, chromium acetate, chromium oxalate, potassium dihydrogen phosphate, chromium acetylacetonate, chromium chloride, potassium chromium sulfate; phosphate treatment using phosphate compounds such as sodium phosphate, potassium phosphate, ammonium phosphate, polyphosphoric acid; chemical surface treatment using an aminoated phenol polymer having repeating units represented by the following general formulas (1) to (4), etc. Among them, in the aminoated phenol polymer, the repeating units represented by the following general formulas (1) to (4) may contain 1 type alone, or may be any combination of 2 or more types.

[0112]

[0113] In the general formulas (1) to (4), X represents a hydrogen atom, a hydroxyl group, an alkyl group, a hydroxyalkyl group, an allyl group, or a benzyl group. Further, R 1 and R 2 are the same or different, and represent a hydroxyl group, an alkyl group, or a hydroxyalkyl group. In the general formulas (1) to (4), as the alkyl groups represented by X, R 1 and R 2 for example, linear or branched alkyl groups having 1 or more and 4 or less carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, etc. can be cited. Further, as the hydroxyalkyl groups represented by X, R 1 and R 2 for example, linear or branched alkyl groups having 1 or more and 4 or less carbon atoms substituted with 1 hydroxyl group such as hydroxymethyl, 1-hydroxyethyl, 2-hydroxyethyl, 1-hydroxypropyl, 2-hydroxypropyl, 3-hydroxypropyl, 1-hydroxybutyl, 2-hydroxybutyl, 3-hydroxybutyl, 4-hydroxybutyl, etc. can be cited. In the general formulas (1) to (4), the alkyl groups and hydroxyalkyl groups represented by X, R 1 and R 2 can 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 aminoated phenol polymer having repeating units represented by the general formulas (1) to (4) is, for example, preferably about 500 to 1,000,000, and more preferably about 1,000 to 20,000.

[0114] In addition, as a chemical surface treatment method for imparting corrosion resistance to the barrier layer 3, the following methods can be cited: a method of coating a substance in which fine particles of metal oxides such as alumina, titanium oxide, cerium oxide, tin oxide or barium sulfate are dispersed in phosphoric acid and performing a sintering treatment at 150°C or higher to form a corrosion-resistant treatment layer on the surface of the barrier layer 3. Further, a resin layer formed by crosslinking a cationic polymer with a crosslinking agent can be formed on the corrosion-resistant treatment layer. Here, as the cationic polymer, for example, polyethyleneimine, an ionic polymer complex composed of polyethyleneimine and a polymer having a carboxylic acid, a primary amine-grafted acrylic resin obtained by graft-polymerizing a primary amine on an acrylic main skeleton, polyallylamine or its derivatives, aminophenol, etc. can be cited. As these cationic polymers, only one kind can be used, or two or more kinds can be used in combination. In addition, as the crosslinking agent, for example, a compound having at least one functional group selected from isocyanate group, glycidyl group, carboxyl group and oxazoline group, a silane coupling agent, etc. can be cited. As these crosslinking agents, only one kind can be used, or two or more kinds can be used in combination.

[0115] In addition, as a chemical surface treatment method for imparting corrosion resistance to the barrier layer 3, the following methods can be cited: a method of coating a substance in which fine particles of metal oxides such as alumina, titanium oxide, cerium oxide, tin oxide or barium sulfate are dispersed in phosphoric acid and performing a sintering treatment at 150°C or higher to form an acid-resistant film on the surface of the barrier layer 3. Further, a resin layer formed by crosslinking a cationic polymer with a crosslinking agent can be formed on the acid-resistant film. Here, as the cationic polymer, for example, polyethyleneimine, an ionic polymer complex composed of polyethyleneimine and a polymer having a carboxylic acid, a primary amine-grafted acrylic resin obtained by graft-polymerizing a primary amine on an acrylic main skeleton, polyallylamine or its derivatives, aminophenol, etc. can be cited. As these cationic polymers, only one kind can be used, or two or more kinds can be used in combination. In addition, as the crosslinking agent, for example, a compound having at least one functional group selected from isocyanate group, glycidyl group, carboxyl group and oxazoline group, a silane coupling agent, etc. can be cited. As these crosslinking agents, only one kind can be used, or two or more kinds can be used in combination.

[0116] In addition, as a specific method for setting the acid-resistant film, for example, as an example, first, at least the surface on the inner layer side of the aluminum foil is degreased by known treatment methods such as alkali impregnation method, electrolytic cleaning method, acid cleaning method, electrolytic acid cleaning method, acid activation method, etc. Then, a treatment liquid (aqueous solution) mainly composed of metal phosphates such as chromium phosphate, titanium phosphate, zirconium phosphate, zinc phosphate, etc. and mixtures of these metal salts, or a treatment liquid (aqueous solution) mainly composed of non-metal phosphates and mixtures of these non-metal salts, or a treatment liquid (aqueous solution) containing a mixture of them and a water-based synthetic resin such as acrylic resin, phenolic resin or polyurethane resin is coated on the degreased surface by a known coating method such as roll coating method, gravure printing method, dipping method, etc., whereby an acid-resistant film can be formed. For example, in the case of treatment with a chromium phosphate-based treatment liquid, an acid-resistant film composed of chromium phosphate, aluminum phosphate, aluminum oxide, aluminum hydroxide, aluminum fluoride, etc. is obtained; in the case of treatment with a zinc phosphate-based treatment liquid, an acid-resistant film composed of zinc phosphate hydrate, aluminum phosphate, aluminum oxide, aluminum hydroxide, aluminum fluoride, etc. is obtained.

[0117] In addition, as another example of the specific method for setting the acid-resistant film, for example, first, at least the surface on the inner layer side of the aluminum foil is degreased by known treatment methods such as alkali impregnation method, electrolytic cleaning method, acid cleaning method, electrolytic acid cleaning method, acid activation method, etc. Then, a known anodizing treatment is performed on the degreased surface, whereby an acid-resistant film can be formed.

[0118] In addition, as another example of the acid-resistant film, phosphate-based and chromic acid-based films can be cited. As the phosphate-based, zinc phosphate, iron phosphate, manganese phosphate, calcium phosphate, chromium phosphate, etc. can be cited, and as the chromic acid-based, chromium chromate, etc. can be cited.

[0119] In addition, as another example of the acid-resistant film, by forming an acid-resistant film of phosphate, chromate, fluoride, triazine mercaptan compound, etc., the following effects can be exhibited: preventing delamination between aluminum and the substrate layer during embossing; preventing dissolution and corrosion of the aluminum surface caused by hydrogen fluoride generated by the reaction of the electrolyte with moisture, especially the dissolution and corrosion of aluminum oxide present on the aluminum surface; and improving the adhesiveness (wettability) of the aluminum surface; preventing delamination between the substrate layer and aluminum during heat sealing; preventing delamination between the substrate layer and aluminum during press forming in the embossing type. Among the substances for forming the acid-resistant film, it is preferable to coat an aqueous solution composed of three components of phenolic resin, chromium(III) fluoride compound, and phosphoric acid on the aluminum surface and perform a drying and sintering treatment.

[0120] In addition, the acid-resistant film includes a layer having cerium oxide, phosphoric acid or phosphate, an anionic polymer, and a crosslinking agent that crosslinks the anionic polymer. About 1 to 100 parts by mass of the phosphoric acid or phosphate can be incorporated per 100 parts by mass of the cerium oxide. The acid-resistant film preferably has a multilayer structure further including a layer having a cationic polymer and a crosslinking agent that crosslinks the cationic polymer.

[0121] Moreover, the anionic polymer is preferably poly(meth)acrylic acid or its salt, or a copolymer having (meth)acrylic acid or its salt as a main component. In addition, the crosslinking agent is preferably at least one selected from compounds having any functional groups such as isocyanate group, glycidyl group, carboxyl group, oxazoline group, and silane coupling agents.

[0122] In addition, the phosphoric acid or phosphate is preferably condensed phosphoric acid or condensed phosphate.

[0123] For the chemical surface treatment, only one type of chemical surface treatment can be performed, or two or more types of chemical surface treatments can be combined. Moreover, these chemical surface treatments can be performed using a single compound alone, or two or more compounds can be used in combination. In the chemical surface treatment, a chemical surface treatment combining chromate treatment, chromium compounds, phosphoric acid compounds, and amino-phenol polymers is preferred. Among the chromium compounds, chromic acid compounds are preferred.

[0124] As a specific example of the acid-resistant film, a film containing at least one of phosphate, chromate, fluoride, and triazine thiol can be cited. In addition, an acid-resistant film containing a cerium compound is also preferred. As the cerium compound, cerium oxide is preferred.

[0125] In addition, as specific examples of the acid-resistant film, phosphate-based films, chromate-based films, fluoride-based films, triazine thiol compound films, etc. can be cited. As the acid-resistant film, one of them can be used, or a combination of multiple types can be used. Moreover, as the acid-resistant film, it can be formed by using a treatment liquid composed of a mixture of a metal phosphate and an aqueous synthetic resin, or a treatment liquid composed of a mixture of a non-metal phosphate and an aqueous synthetic resin after degreasing the chemically surface-treated surface of the aluminum foil.

[0126] Among them, the composition analysis of the acid-resistant film can be performed, for example, using time-of-flight secondary ion mass spectrometry. Through the composition analysis of the acid-resistant film using time-of-flight secondary ion mass spectrometry, peaks from at least one of Ce + and Cr + can be detected, for example.

[0127] Preferably, the surface of the aluminum foil has an acid-resistant film containing at least one element selected from phosphorus, chromium, and cerium. Among them, the fact that the acid-resistant film on the surface of the aluminum foil of the battery packaging material contains at least one element selected from phosphorus, chromium, and cerium can be confirmed by X-ray photoelectron spectroscopy. Specifically, first, in the battery packaging material, the heat-sealable resin layer, adhesive layer, etc. laminated on the aluminum foil are peeled off physically. Then, the aluminum foil is placed in an electric furnace, and the organic components present on the surface of the aluminum foil are removed at about 300 °C for about 30 minutes. After that, these elements are confirmed by X-ray photoelectron spectroscopy of the aluminum foil surface.

[0128] Regarding the amount of the acid-resistant film formed on the surface of the barrier layer 3 by chemical surface treatment, there is no particular limitation. For example, in the case of performing the above-mentioned chromate treatment, on the surface of the barrier layer 3, it is desirable that the content ratio of the chromium compound in terms of chromium is about 0.5 to 50 mg, preferably about 1.0 to 40 mg, the content ratio of the phosphorus compound in terms of phosphorus is about 0.5 to 50 mg, preferably 1.0 to 40 mg, and the content ratio of the amino-phenol polymer is about 1.0 to 200 mg, preferably 5.0 to 150 mg. 2 As for the thickness of the acid-resistant film, there is no particular limitation. From the viewpoints of the cohesive force of the film and the adhesion force to the aluminum foil and the heat-sealable resin layer, it is preferably about 1 nm to 10 μm, more preferably about 1 to 100 nm, and further preferably about 1 to 50 nm. Among them, the thickness of the acid-resistant film can be measured by observation using a transmission electron microscope or a combination of observation using a transmission electron microscope and energy-dispersive X-ray spectroscopy or electron energy loss spectroscopy.

[0129] The chemical surface treatment can be carried out as follows: A solution containing a compound for forming an acid-resistant film is coated on the surface of the barrier layer by a bar coating method, roll coating method, gravure coating method, dipping method, etc., and then heated to make the temperature of the barrier layer reach about 70 to 200 °C. And before performing the chemical surface treatment on the barrier layer, the barrier layer can be degreased by an alkali dipping method, electrolytic cleaning method, acid cleaning method, electrolytic acid cleaning method, etc. By performing such degreasing treatment, the chemical surface treatment of the barrier layer surface can be carried out more efficiently.

[0130] In the battery packaging material of the present invention, the heat-sealable resin layer 4 corresponds to the innermost layer, and it is the layer that seals the battery elements by heat-sealing the heat-sealable resin layers to each other when assembling the battery.

[0131] [Heat-sealable resin layer 4]

[0132]

[0133] Regarding the resin component used for the heat-sealable resin layer 4, there is no particular limitation as long as it can be heat-sealed. For example, polyolefins, cyclic polyolefins, carboxylic acid-modified polyolefins, and carboxylic acid-modified cyclic polyolefins can be cited. That is, whether the resin constituting the heat-sealable resin layer 4 contains a polyolefin backbone or not is acceptable, and it is preferably to contain a polyolefin backbone. Whether the resin constituting the heat-sealable resin layer 4 contains a polyolefin backbone can be analyzed, for example, by infrared spectroscopy, gas chromatography-mass spectrometry, etc., and the analysis method is not particularly limited. For example, when measuring maleic anhydride-modified polyolefin by infrared spectroscopy, peaks from maleic anhydride are detected around the wave number of 1760 cm -1 and around the wave number of 1780 cm -1 . However, when the degree of acid modification is low, sometimes the peaks become small and cannot be detected. In this case, nuclear magnetic resonance spectroscopy can be used for analysis.

[0134] As the above polyolefins, specifically, the following can be cited: polyethylene such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene; polypropylene such as homopolypropylene, block copolymers of polypropylene (for example, block copolymers of propylene and ethylene), random copolymers of polypropylene (for example, random copolymers of propylene and ethylene); terpolymers of ethylene-butene-propylene, etc. Among these polyolefins, polyethylene and polypropylene are preferably cited.

[0135] The above cyclic polyolefins are copolymers of olefins and cyclic monomers. As the olefins that are the constituent monomers of the above cyclic polyolefins, for example, ethylene, propylene, 4-methyl-1-pentene, butadiene, isoprene, etc. can be cited. In addition, as the cyclic monomers that are the constituent monomers of the above cyclic polyolefins, for example, cyclic olefins such as norbornene can be cited, and specifically, cyclic dienes such as cyclopentadiene, dicyclopentadiene, cyclohexadiene, norbornadiene, etc. can be cited. In addition, styrene can also be cited as a constituent monomer. Among these polyolefins, cyclic olefins are preferably cited, and norbornene is more preferably cited.

[0136] The above carboxylic acid-modified polyolefins refer to polymers obtained by modifying the above polyolefins by block polymerization or graft polymerization with carboxylic acids. As the carboxylic acids used for modification, for example, maleic acid, acrylic acid, itaconic acid, crotonic acid, maleic anhydride, itaconic anhydride, etc. can be cited.

[0137] The above carboxylic acid-modified cyclic polyolefins refer to polymers obtained by copolymerizing a part of the monomers constituting the cyclic polyolefins with α,β-unsaturated carboxylic acids or their acid anhydrides, or by block polymerization or graft polymerization of α,β-unsaturated carboxylic acids or their acid anhydrides with cyclic polyolefins. Regarding the carboxylic acid-modified cyclic polyolefins, it is the same as above. In addition, as the carboxylic acids used for modification, they are the same as the carboxylic acids used in the modification of the above carboxylic acid-modified polyolefins.

[0138] Among these resin components, carboxylic acid-modified polyolefin is preferably exemplified, and carboxylic acid-modified polypropylene is more preferably exemplified.

[0139] The heat-sealable resin layer 4 can be formed of a single resin component or a blended polymer combining two or more resin components. Also, the heat-sealable resin layer 4 can be formed of only one layer or two or more layers formed of the same or different resin components.

[0140] In addition, as the thickness of the heat-sealable resin layer 4, it can be appropriately selected, and about 8 to 50 μm, preferably about 10 to 40 μm can be exemplified.

[0141] In addition, the heat-sealable resin layer 4 can contain a lubricant or the like as needed. When the heat-sealable resin layer 4 contains a lubricant, the moldability of the battery packaging material can be improved. There is no particular limitation on the lubricant, and known lubricants can be used. For example, the lubricants exemplified in the above-mentioned base material layer 1 can be used. The lubricant can be used alone or in combination of two or more. There is no particular limitation on the content of the lubricant in the heat-sealable resin layer 4. From the viewpoints of improving the moldability and insulation of the electronic packaging material, about 0.01 to 0.20% by mass, more preferably about 0.05 to 0.15% by mass is preferably exemplified.

[0142] [Adhesive layer 5]

[0143] In the battery packaging material of the present invention, the adhesive layer 5 is a layer provided between the barrier layer 3 and the heat-sealable resin layer 4 as needed to firmly bond the barrier layer 3 and the heat-sealable resin layer 4.

[0144] The adhesive layer 5 is formed of a resin capable of bonding the barrier layer 3 and the heat-sealable resin layer 4. As the resin used to form the adhesive layer 5, the same adhesives as those exemplified in the adhesive layer 2 such as the bonding mechanism and the type of adhesive component can be used. In addition, as the resin for forming the adhesive layer 5, polyolefin-based resins such as polyolefin, cyclic polyolefin, carboxylic acid-modified polyolefin, and carboxylic acid-modified cyclic polyolefin exemplified in the above-mentioned heat-sealable resin layer 4 can also be used. From the viewpoint of excellent adhesion between the barrier layer 3 and the heat-sealable resin layer 4, as the polyolefin, carboxylic acid-modified polyolefin is preferred, and carboxylic acid-modified polypropylene is particularly preferred. That is, whether the resin constituting the adhesive layer 5 contains a polyolefin backbone or not is acceptable, and it is preferably included. Whether the resin constituting the adhesive layer 5 contains a polyolefin backbone can be analyzed by, for example, infrared spectroscopy, gas chromatography-mass spectrometry, etc., and the analysis method is not particularly limited. For example, when measuring maleic anhydride-modified polyolefin by infrared spectroscopy, at a wavenumber of 1760 cm -1 near and a wavenumber of 1780 cm -1A peak from maleic anhydride was detected nearby. However, when the degree of acid modification is low, the peak sometimes becomes smaller and cannot be detected. In such a case, nuclear magnetic resonance spectroscopy can be used for analysis.

[0145] Moreover, from the viewpoint of thinning the thickness of the battery packaging material and producing a battery packaging material with excellent formability, the adhesive layer 5 is also preferably a cured product of a resin composition containing an acid-modified polyolefin and a curing agent. As the acid-modified polyolefin, preferred examples are the same substances as the carboxylic acid-modified polyolefin and the carboxylic acid-modified cyclic polyolefin exemplified in the heat-sealable resin layer 4.

[0146] In addition, as the curing agent, any compound that can cure the acid-modified polyolefin can be used, and there is no particular limitation. Examples of the curing agent include epoxy curing agents, polyfunctional isocyanate curing agents, carbodiimide curing agents, oxazoline curing agents, etc.

[0147] The epoxy curing agent only needs to be a compound having at least one epoxy group, and there is no particular limitation. Examples of the epoxy curing agent include epoxy resins such as bisphenol A diglycidyl ether, modified bisphenol A diglycidyl ether, novolak glycidyl ether, glycerol polyglycidyl ether, and polyglycerol polyglycidyl ether.

[0148] The polyfunctional isocyanate curing agent only needs to be a compound having two or more isocyanate groups, and there is no particular limitation. Specific examples of the polyfunctional isocyanate curing agent include isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), substances obtained by polymerizing or urethanizing them, mixtures thereof, or copolymers with other polymers.

[0149] The carbodiimide curing agent only needs to be a compound having at least one carbodiimide group (-N=C=N-), and there is no particular limitation. As the carbodiimide curing agent, a polycarbodiimide compound having at least two or more carbodiimide groups is preferred.

[0150] The oxazoline curing agent only needs to be a compound having an oxazoline skeleton, and there is no particular limitation. Specific examples of the oxazoline curing agent include the EPOCROS series produced by Nippon Shokubai Co., Ltd.

[0151] From the viewpoint of improving the adhesion between the barrier layer 3 and the heat-sealable resin layer 4 by using the adhesive layer 5, the curing agent can be composed of two or more compounds.

[0152] The content of the curing agent in the resin composition for forming the adhesive layer 5 is preferably in the range of about 0.1 to 50% by mass, more preferably in the range of about 0.1 to 30% by mass, and still more preferably in the range of about 0.1 to 10% by mass.

[0153] Regarding the thickness of the adhesive layer 5, there is no particular limitation as long as it can function as an adhesive layer. In the case of using the adhesives exemplified in the adhesive layer 2, it is preferably about 2 to 10 μm, more preferably about 2 to 5 μm. In addition, in the case of using the resins exemplified in the heat-sealable resin layer 4, it is preferably about 2 to 50 μm, more preferably about 10 to 40 μm. Further, in the case of a cured product of an acid-modified polyolefin and a curing agent, it is preferably about 30 μm or less, more preferably about 0.1 to 20 μm, and still more preferably about 0.5 to 5 μm. Among them, in the case where 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 coating the resin composition and curing it by heating or the like.

[0154] [Surface covering layer 6]

[0155] In the battery packaging material of the present invention, in order to improve designability, electrolyte resistance, rub resistance, moldability, etc., a surface covering layer 6 can be provided on the base material layer 1 (on the side of the base material layer 1 opposite to the barrier layer 3) as needed. The surface covering layer 6 is the outermost layer when assembling the battery.

[0156] The surface covering layer 6 can be formed of a resin composition. As the components contained in the resin composition, resin components, curing accelerators, additives (fillers, etc.) can be exemplified as described later.

[0157] Preferably, the resin component contained in the resin composition includes a thermosetting resin. As the thermosetting resin, any resin that polymerizes upon heating to form a network structure of high molecules and thus cures can be used. Specifically, polyvinylidene fluoride, polyester resin, epoxy resin, amino resin (melamine resin, benzoguanamine resin, etc.), acrylic resin, polyurethane resin, phenolic resin, unsaturated polyester resin, alkyd resin, etc. can be exemplified as the thermosetting resin.

[0158] Among these thermosetting resins, from the viewpoints of shortening the curing time, improving moldability and chemical resistance, etc., polyurethane resin and epoxy resin are preferably exemplified, two-component curable polyurethane resin and two-component curable epoxy resin are more preferably exemplified, and two-component curable epoxy resin is particularly preferably exemplified.

[0159] As the two-component curable polyurethane resin, specifically, a combination of a polyol compound (main agent) and an isocyanate compound (curing agent) can be cited. As the two-component curable epoxy resin, specifically, a combination of an epoxy resin (main agent) and an acid anhydride, an amine compound, or an amino resin (curing agent) can be cited. In addition, as the two-component curable polyurethane resin, a polyfunctional polyurethane (meth)acrylate composed of a combination of a polyfunctional (meth)acrylate having an active hydrogen (main agent) and a polyisocyanate (curing agent) is also preferred.

[0160] In the two-component curable polyurethane resin, the polyol compound used as the main agent is not particularly limited. For example, polyester polyol, polyester polyurethane polyol, polyether polyol, polyether polyurethane polyol, etc. can be cited. These polyol compounds can be used alone or in combination of two or more.

[0161] In addition, in the two-component curable polyurethane resin, the isocyanate compound used as the curing agent is not particularly limited. For example, polyisocyanate, its adduct, its isocyanurate-modified product, its carbodiimide-modified product, its urethane-modified product, its biuret-modified product, etc. can be cited. As the polyisocyanate, specifically, diphenylmethane diisocyanate (MDI), polyphenylmethane diisocyanate (poly-MDI), toluene diisocyanate (TDI), hexamethylene diisocyanate (HDI), bis(4-isocyanatocyclohexyl)methane (H12MDI), isophorone diisocyanate (IPDI), 1,5-naphthalene diisocyanate (1,5-NDI), 3,3'-dimethyl-4,4'-diphenylene diisocyanate (TODI), xylene diisocyanate (XDI), etc. aromatic diisocyanates; tetramethylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, isophorone diisocyanate, etc. aliphatic diisocyanates; 4,4'-methylenebis(cyclohexyl isocyanate), isophorone diisocyanate, etc. alicyclic diisocyanates; 1,5-naphthalene diisocyanate (1,5-NDI), etc. polycyclic aromatic diisocyanates, etc. As the adduct, specifically, a substance obtained by adding trimethylolpropane, diol, etc. to the above polyisocyanate can be cited. These isocyanate compounds can be used alone or in combination of two or more.

[0162] In addition, these thermosetting resins can also be crosslinkable elastomers. A crosslinkable elastomer is a thermosetting resin that can provide a soft segment to the cured product. For example, in the case of a crosslinkable elastomer being a two-component curable polyurethane resin or a two-component curable epoxy resin, as long as the above main agent has a structure capable of providing a soft segment. In order to make the layer constituting the surface covering layer 6 have the desired hardness, the crosslinkable elastomer can be used as a part of the thermosetting resin for forming the layer constituting the surface covering layer 6.

[0163] These thermosetting resins can be used individually, or two or more of them can be used in combination. Moreover, the surface covering layer 6 can be formed of multiple layers. When the surface covering layer 6 is formed of multiple layers, the thermosetting resins used in each layer can be the same or different, and the types of thermosetting resins can be appropriately selected according to the functions and physical properties desired for each layer. For example, in the layer forming the outermost surface layer among the layers constituting the surface covering layer 6 (the outermost surface layer on the side opposite to the base material layer 1), from the viewpoint of having excellent chemical resistance, it is suitable to use a thermosetting resin having a polycyclic aromatic skeleton and / or a heterocyclic skeleton. As the thermosetting resin having a polycyclic aromatic skeleton, specifically, an epoxy resin having a polycyclic aromatic skeleton and a polyurethane resin having a polycyclic aromatic skeleton can be cited. In addition, as the thermosetting resin having a heterocyclic skeleton, specifically, amino resins such as melamine resin and benzoguanamine resin can be cited. These thermosetting resins having a polycyclic aromatic skeleton and / or a heterocyclic skeleton can be of any type, either a one-component curing type or a two-component curing type.

[0164] As the epoxy resin having a polycyclic aromatic skeleton, more specifically, a reaction product of dihydroxynaphthalene and epihalohydrin; a reaction product of a condensate of naphthol and aldehydes (naphthol novolak resin) and epihalohydrin; a reaction product of a condensate of dihydroxynaphthalene and aldehydes and epihalohydrin; a reaction product of a condensate of mono- or dihydroxynaphthalene and phthalyl alcohols and epihalohydrin; a reaction product of an adduct of mono- or dihydroxynaphthalene and a diene compound and epihalohydrin; a reaction product of polynaphthols directly coupled between naphthols and epihalohydrin, etc. can be cited.

[0165] As the polyurethane resin having a polycyclic aromatic skeleton, more specifically, a reaction product of a polyol compound and an isocyanate compound having a polycyclic aromatic skeleton can be cited.

[0166] (Curing accelerator)

[0167] In addition to the above resin components, the resin composition for forming the surface covering layer 6 can also contain a curing accelerator. By coexisting the curing accelerator with the thermosetting resin, curing under high-temperature conditions is not required during manufacturing, the surface covering layer 6 can be cured in a short time, and a layer having a specific hardness can be formed.

[0168] Here, the so-called "curing accelerator" is a substance that does not form a crosslinked structure alone but promotes the crosslinking reaction of the thermosetting resin, and is a substance that has the effect of promoting the crosslinking reaction of the thermosetting resin and sometimes forms a crosslinked structure itself.

[0169] Regarding the types of curing accelerators, they can be appropriately selected according to the thermosetting resin used in a manner that can meet the above-mentioned hardness. For example, amidine compounds, carbodiimide compounds, ketimine compounds, hydrazine compounds, sulfonium salts, benzothiazolium salts, tertiary amine compounds, etc. can be cited.

[0170] Regarding the amidine compounds, there is no particular limitation. For example, imidazole compounds, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 1,5-diazabicyclo[4.3.0]non-5-ene (DBN), guanidine compounds, etc. can be cited. Regarding the imidazole compounds, specifically, 2-methylimidazole, 2-ethylimidazole, 2-undecylimidazole, 2,4-dimethylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 1,2-diethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-benzyl-2-methylimidazole, 2,4-diamino-6-[2'-methylimidazolyl-(1)']-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1)']-ethyl-s-triazine, 2,4-diamino-6-[2'-undecylimidazolyl]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1)']-ethyl-s-triazine isocyanurate adduct, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-aryl-4,5-diphenylimidazole, etc. can be cited. These amidine compounds can be used alone as 1 type, or 2 or more types can be used in combination.

[0171] Regarding the carbodiimide compounds, there is no particular limitation. For example, N,N'-dicyclohexylcarbodiimide, N,N'-diisopropylcarbodiimide, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, N-[3-(dimethylamino)propyl]-N'-ethylcarbodiimide, N-[3-(dimethylamino)propyl]-N'-ethylcarbodiimide methyl iodide, N-tert-butyl-N'-ethylcarbodiimide, N-cyclohexyl-N'-(2-morpholinoethyl)carbodiimide m-p-toluenesulfonate, N,N'-di-tert-butylcarbodiimide, N,N'-di-p-tolylcarbodiimide, etc. can be cited. These carbodiimide compounds can be used alone as 1 type, or 2 or more types can be used in combination.

[0172] As the ketimine compound, there is no particular limitation as long as it has a ketimine bond (N=C). For example, a ketimine compound obtained by reacting a ketone with an amine can be cited. As the ketone, specific examples include methyl ethyl ketone, methyl isopropyl ketone, methyl tert-butyl ketone, methyl cyclohexyl ketone, diethyl ketone, ethyl propyl ketone, ethyl butyl ketone, dipropyl ketone, dibutyl ketone, diisobutyl ketone, etc. In addition, as the amine, specific examples include aromatic polyamines such as o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, m-xylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, diaminodiethyldiphenylmethane; aliphatic polyamines such as ethylenediamine, propylenediamine, butylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexamethylenediamine, trimethylhexamethylenediamine, 1,2-propanediamine, iminobispropylamine, methyliminobispropylamine; monoamines having an ether bond in the main chain such as N-aminoethylpiperazine, 3-butoxyisopropylamine or diamines having a polyether skeleton; alicyclic polyamines such as isophoronediamine, 1,3-bis(aminomethyl)cyclohexane, 1-cyclohexylamino-3-aminopropane, 3-aminomethyl-3,3,5-trimethylcyclohexylamine; diamines having a norbornane skeleton; polyamide amines having an amino group at the molecular end of a polyamide; 2,5-dimethyl-2,5-hexamethylenediamine, alkanediamine, 1,4-bis(2-amino-2-methylpropyl)piperazine, etc. as specific examples. These ketimine compounds can be used alone or in combination of two or more.

[0173] As the hydrazine compound, there is no particular limitation. For example, di-pinonic dihydrazide, isophthalic dihydrazide, etc. can be cited. These hydrazine compounds can be used alone or in combination of two or more.

[0174] As the sulfonium salt, there is no particular limitation. For example, alkyl sulfonium salts such as 4-acetylphenyldimethylsulfonium hexafluoroantimonate, 4-acetylphenyldimethylsulfonium hexafluoroarsenate, dimethyl-4-(benzyloxycarbonyloxy)phenylsulfonium hexafluoroantimonate, dimethyl-4-(benzoyloxy)phenylsulfonium hexafluoroantimonate, dimethyl-4-(benzoyloxy)phenylsulfonium hexafluoroarsenate, etc.; benzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, 4-acetoxyphenylbenzylmethylsulfonium hexafluoroantimonate, benzyl-4-methoxyphenylmethylsulfonium hexafluoroantimonate, benzyl-3-chloro-4-hydroxyphenylmethylsulfonium hexafluoroarsenate, 4-methoxybenzyl-4-hydroxyphenylmethylsulfonium hexafluorophosphate, etc.; dibenzyl-4-hydroxyphenylsulfonium hexafluoroantimonate, dibenzyl-4-hydroxyphenylsulfonium hexafluorophosphate, dibenzyl-4-methoxyphenylsulfonium hexafluoroantimonate, benzyl-4-methoxybenzyl-4-hydroxyphenylsulfonium hexafluorophosphate, etc.; substituted benzylsulfonium salts such as p-chlorobenzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, p-nitrobenzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, 3,5-dichlorobenzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, o-chlorobenzyl-3-chloro-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, etc. These sulfonium salts can be used alone or in combination of two or more.

[0175] As the benzothiazolium salt, there is no particular limitation. For example, benzylbenzothiazolium salts such as 3-benzylbenzothiazolium hexafluoroantimonate, 3-benzylbenzothiazolium hexafluorophosphate, 3-benzylbenzothiazolium tetrafluoroborate, 3-(p-methoxybenzyl)benzothiazolium hexafluoroantimonate, 3-benzyl-2-methylthiobenzothiazolium hexafluoroantimonate, 3-benzyl-5-chlorobenzothiazolium hexafluoroantimonate, etc. These benzothiazolium salts can be used alone or in combination of two or more.

[0176] As the tertiary amine compound, there is no particular limitation. For example, aliphatic tertiary amines such as trimethylamine, triethylamine, tripropylamine, tributylamine, triethylenediamine, 1,4-diazabicyclo[2.2.2]octane, quinuclidine, 3-quinuclidinol, etc.; aromatic tertiary amines such as dimethylaniline, etc.; heterocyclic tertiary amines such as isoquinoline, pyridine, collidine, β-picoline, etc. These tertiary amine compounds can be used alone or in combination of two or more.

[0177] As a preferred example of the curing accelerator, a substance that functions as a thermal acid generator can be cited. A thermal acid generator is a substance that generates an acid by heating and functions as a curing accelerator. Among the above-mentioned curing accelerators, substances that can function as thermal acid generators specifically include sulfonium salts, benzothiazolium salts, etc.

[0178] In addition, as another preferred example of the curing accelerator, a latent heat substance that activates under specified heating conditions (e.g., 80 to 200 °C, preferably 100 to 160 °C) to promote the crosslinking reaction of the thermosetting resin can be cited. Among the above-mentioned curing accelerators, as the latent heat substance, specifically, epoxy adducts obtained by adding an epoxide compound to an amidine compound, a hydrazine compound, a tertiary amine compound, etc. can be cited.

[0179] In addition, as another preferred example of the above-mentioned curing accelerator, a substance having hydrolyzable latency that does not act as a curing agent in a closed state, i.e., a state where moisture is blocked, but hydrolyzes and acts as a curing agent under open and closed conditions where moisture is present can be cited. Among the above-mentioned curing accelerators, as the substance having hydrolyzable latency, specifically, epoxy adducts obtained by adding an epoxide compound to an amidine compound, a hydrazine compound, a tertiary amine compound, etc. can be cited.

[0180] These curing accelerators can be used alone as one kind, or two or more kinds can be used in combination. Among these curing accelerators, amidine compounds and sulfonium salts are preferably cited, and amidine compounds are more preferably cited.

[0181] These curing accelerators can be used alone as one kind in the above-mentioned surface covering layer 6, or two or more kinds can be used in combination. In addition, when the surface covering layer 6 is formed of multiple layers, the curing accelerators used for each layer constituting the surface covering layer 6 can be the same or different, and the type of curing accelerator can be appropriately selected according to the functions and physical properties desired for each layer.

[0182] When using a curing accelerator, the content of the curing accelerator in the resin composition for forming the surface covering layer 6 can be appropriately set according to the type of the thermosetting resin used, the type of the curing accelerator, etc. For example, relative to 100 parts by mass of the thermosetting resin, the total amount of the curing accelerator can be cited as about 0.01 to 6 parts by mass, preferably about 0.05 to 5 parts by mass, and more preferably about 0.1 to 2 parts by mass.

[0183] In the surface covering layer 6, as an additive, a filler is preferably contained. That is, it is preferred that the surface covering layer 6 is formed of a resin composition containing a filler. By containing a filler in the surface covering layer 6, an uneven shape can be formed on the surface of the surface covering layer 6, and a matte feeling can be imparted to the battery packaging material. As specific examples of the filler, inorganic fillers such as titanium oxide, silica, talc, clay, heavy calcium carbonate, light calcium carbonate, barium sulfate, calcium silicate, synthetic silicate, aluminum hydroxide, and silica fine powder can be cited. The filler can be used alone as one kind, or two or more kinds can be mixed and used.

[0184] Among inorganic fillers, from the viewpoints of easy handling and easy availability, inorganic fillers made of silica or precipitated barium sulfate are preferred. Among them, precipitated barium sulfate refers to barium sulfate obtained by chemical reaction and has the characteristic of being able to control the particle size.

[0185] As the content of the filler in the surface covering layer 6, for example, when the filler is silica with an average particle size of about 1.0 to 3.0 μm, it is preferably about 2.0 to 8.7% by mass; in addition, for example, when the filler is precipitated barium sulfate with an average particle size of less than 1.5 μm, it is preferably about 13.0 to 40.0% by mass. The content of the filler refers to the content of the filler in the surface covering layer 6 and is the content after the solvent has been volatilized from the above resin composition containing the filler for forming the surface covering layer 6. Among them, the average particle size of the filler is the median diameter measured by a laser diffraction / scattering particle size distribution measuring device.

[0186] In the surface covering layer 6, as an additive, at least one of a pigment and a dye can be contained. When the surface covering layer 6 contains at least one of a pigment and a dye, whitening during molding can be more effectively suppressed, and abrasion resistance can also be improved. And by the surface covering layer 6 containing at least one of a pigment and a dye, recognition can be imparted to the battery packaging material of the present invention (color development due to at least one of the pigment and the dye), a matte design can be imparted to the surface of the battery packaging material of the present invention, and the heat dissipation property can be improved by increasing the thermal conductivity of the battery packaging material of the present invention.

[0187] The material of the pigment is not particularly limited, and any of inorganic pigments or organic pigments can be used. As the above inorganic pigments, specifically, carbon black, carbon nanotubes, graphite, kaolin, magnesium hydroxide, zinc oxide, magnesium oxide, aluminum oxide, neodymium oxide, antimony oxide, cerium oxide, calcium sulfate, lithium carbonate, gold, aluminum, copper, nickel, etc. can be cited. As organic pigments, specifically, azo pigments, polycyclic pigments, lake pigments, fluorescent pigments, etc. can be cited. These pigments can be used alone or in combination of two or more.

[0188] The shape of the pigment is not particularly limited, and for example, spherical, fibrous, plate-like, amorphous, hollow spherical, etc. can be cited. And the average particle size of the pigment is not particularly limited, and for example, preferably about 0.01 to 3 μm, more preferably about 0.05 to 1 μm. Among them, the average particle size of the pigment is the median diameter measured by a laser diffraction / scattering particle size distribution measuring device.

[0189] For the pigment, various surface treatments such as insulation treatment and high-dispersibility treatment (resin coating treatment) can be carried out on the surface as needed.

[0190] In addition, regarding the types of dyes, as long as they can be dissolved and dispersed in the resin composition for forming the surface covering layer 6, there are no particular limitations. For example, nitro dyes, azo dyes, stilbene dyes, carbonium dyes, quinoline dyes, methine dyes, thiazole dyes, quinone imine dyes, anthraquinone dyes, indigo dyes, phthalocyanine dyes, etc. can be cited. Preferably, azo dyes, carbonium dyes, anthraquinone dyes, etc. are cited. These dyes can be used alone, or two or more of them can be used in combination.

[0191] Among these pigments and dyes, from the viewpoint of further improving the heat dissipation property of the battery packaging material of the present invention, pigments are preferably cited, and inorganic pigments are more preferably cited. Further preferably, carbon materials such as carbon black, carbon nanotubes, and graphite are cited, and carbon black is particularly preferably cited.

[0192] In the case where the surface covering layer 6 has a multilayer structure composed of two or more layers, when the above-mentioned pigments, etc. are contained, the pigments and / or dyes can be contained within two or more of them, can be contained in any one layer, or can be contained in two or more layers. After the battery packaging material of the present invention is molded, from the viewpoint of reducing the color tone difference between the molded part and the non-molded part, it is preferable that the surface covering layer 6 is formed as a multilayer structure composed of two or more layers and contains pigments and / or dyes in two or more layers; more preferably, the surface covering layer 6 is formed as a three-layer structure composed of three layers and contains pigments and / or dyes in all three layers.

[0193] When pigments and / or dyes are contained in at least one layer constituting the surface covering layer 6, their content can be appropriately set according to the types of the pigments and / or dyes used, the recognition property and heat dissipation property desired to be imparted to the battery packaging material of the present invention, etc. For example, it can be cited that, relative to 100 parts by mass of the resin component contained in the layer containing pigments and / or dyes, the total amount of the pigments and / or dyes is about 1 to 30 parts by mass. From the viewpoint of imparting more excellent recognition property, it can be cited that, relative to 100 parts by mass of the resin component contained in the layer containing pigments and / or dyes, the total amount of the pigments and / or dyes is about 3 to 20 parts by mass. In addition, from the viewpoints of more excellent recognition property and suppressing the decrease in moldability caused by pigments and / or dyes, it can be cited that, relative to 100 parts by mass of the resin component contained in the layer containing pigments and / or dyes, the total amount of the pigments and / or dyes is about 5 to 15 parts by mass.

[0194] In the resin composition for forming the surface covering layer 6, according to the functionality, etc. that the surface covering layer 6 is desired to have, in addition to the above-mentioned additives, other additives such as organic fillers, lubricants, solvents, elastomeric resins, etc. can also be contained as needed.

[0195] When an organic filler or a lubricant is contained as an additive in the surface coating layer 6, it is possible to impart a sliding effect to the surface of the battery packaging material of the present invention, improve the formability and processability of compression molding or embossing, and make the operability better.

[0196] The type of the organic filler is not particularly limited, and examples thereof include high melting point nylon, acrylate resin, crosslinked acrylic acid, crosslinked styrene, crosslinked polyethylene, benzoguanamine, etc. In addition, the shape of the organic filler is not particularly limited, and examples thereof include spherical, fibrous, plate-like, amorphous, hollow spherical, etc.

[0197] In addition, the lubricant is not particularly limited, and for example, it may be a non-reactive lubricant or a reactive lubricant. In particular, the reactive lubricant has the advantages that the lubricant is not easily leaked and lost from the outermost layer constituting the surface coating layer 6, it is possible to suppress powdering or back transfer during use, or the sliding effect does not decrease over time. Therefore, among the lubricants, reactive lubricants are preferably listed.

[0198] Here, the non-reactive lubricant refers to a compound that does not have a functional group that reacts with the above resin component and is chemically bonded, and can impart slidability (slip property). In addition, the reactive lubricant refers to a compound that has a functional group that reacts with the above resin component and is chemically bonded, and can impart slidability (slip property).

[0199] Specific examples of the non-reactive lubricant include, for example, amide-based lubricants, fatty acid amides, metal soaps, hydrophilic silicones, acrylic acid grafted with silicone, epoxy grafted with silicone, polyether grafted with silicone, polyester grafted with silicone, block-type silicone acrylic copolymers, polyglycerol-modified silicones, paraffin wax, etc. As the amide-based lubricant, for example, the above amide-based lubricant can be used. These non-reactive lubricants can be used alone or in combination of two or more.

[0200] In addition, in the reactive lubricant, the type of the functional group can be appropriately set according to the type of the resin component used. For example, it can include hydroxyl group, mercapto group, hydrolyzable silyl group, isocyanate group, epoxy group, polymerizable vinyl group, (meth)acryloyl group, etc. In the reactive lubricant, the number of functional groups per molecule is not particularly limited, and for example, it can be 1 to 3, preferably 1 or 2.

[0201] Examples of the reactive lubricant include: modified silicone having the above functional groups; modified fluororesin having the above functional groups; compounds in which the above functional groups are introduced into fatty acid amides such as stearic acid amide, oleic acid amide, erucic acid amide, and ethylene bisstearic acid amide; metal soaps into which the above functional groups are introduced; paraffin into which the above functional groups are introduced, and the like. These reactive lubricants may be used alone or in combination of two or more. Among these reactive lubricants, modified silicone having the above functional groups, modified fluororesin having the above functional groups, and silicone-modified resin having the above functional groups are preferably exemplified. Examples of the modified silicone include modified silicone in which a polymer having the above functional groups is block-polymerized, such as modified silicone block-polymerized with an acrylic resin; modified silicone in which a monomer having the above functional groups is graft-polymerized, such as modified silicone graft-polymerized with an acrylate. In addition, examples of the modified fluororesin include modified fluororesin in which a monomer having the above functional groups is graft-polymerized, such as fluororesin graft-polymerized with an acrylate; modified fluororesin in which a polymer having the above functional groups is block-polymerized, such as modified fluororesin block-polymerized with an acrylic resin. In addition, examples of the silicone-modified resin include silicone-modified acrylic resin in which silicone is graft-polymerized onto an acrylic resin having the above functional groups, and silicone-modified resin having the above functional groups and graft-polymerized with silicone. Among these, as a particularly preferred reactive lubricant, modified silicone obtained by polymerizing a monomer or polymer having the above functional groups at one end of silicone; modified fluororesin obtained by polymerizing a monomer or polymer having the above functional groups at one end of fluororesin can be exemplified. As such modified silicone and modified fluororesin, for example, "MODIPER (registered trademark) F·FS series" (manufactured by NOF Corporation), "SYMAC (registered trademark) series" (manufactured by Toagosei Co., Ltd.) are commercially available, and these commercially available products can be used.

[0202] When the resin composition used for forming the outermost layer of the surface covering layer 6 contains a lubricant, its content is not particularly limited. For example, with respect to 100 parts by mass of the resin component, the total amount of the lubricant can be, for example, about 1 to 12 parts by mass, preferably about 3 to 10 parts by mass, and more preferably about 5 to 8 parts by mass.

[0203] In addition, specific examples of the additive include montmorillonite, montmorillonite, synthetic mica, hydrotalcite, zeolite, calcium benzoate, calcium oxalate, magnesium stearate, gold, aluminum, copper, nickel, and the like.

[0204] As a method for forming the surface covering layer 6, there is no particular limitation. For example, a method of coating a resin composition for forming the surface covering layer 6 on one surface of the base material layer 1 can be cited. When additives are incorporated, the additives can be added to the resin composition and mixed before coating.

[0205] As for the thickness of the surface covering layer 6, as long as it can exhibit the above functions as the surface covering layer 6, there is no particular limitation. For example, about 0.5 to 10 μm, preferably about 1 to 5 μm can be cited.

[0206] 3. Manufacturing Method of Packaging Material for Battery

[0207] Regarding the manufacturing method of the battery packaging material of the present invention, as long as a laminate formed by laminating each layer having a specified composition can be obtained, there is no particular limitation. As an example of the manufacturing method of the battery packaging material of the present invention, there is the following method. First, a laminate (hereinafter sometimes referred to as "laminate A") in which the base material layer 1, the adhesive layer 2, and the barrier layer 3 are laminated in sequence is formed. Regarding the formation of the laminate A, specifically, it can be carried out by a dry lamination method. In the dry lamination method, an adhesive for forming the adhesive layer 2 is coated on the base material layer 1 or on the barrier layer 3 whose surface has been subjected to a chemical surface treatment as needed by a coating method such as a gravure coating method or a roll coating method, and dried. Then, the barrier layer 3 or the base material layer 1 is laminated to cure the adhesive layer 2. At this time, aging can be carried out as needed. When a coloring layer 7 is provided between the base material layer 1 and the adhesive layer 2, an ink for forming the coloring layer 7 is previously coated on one surface of the base material layer 1, and the adhesive layer 2 and the barrier layer 3 are laminated to obtain the laminate A.

[0208] Next, a heat-sealable resin layer 4 is laminated on the barrier layer 3 of the laminate A. When the heat-sealable resin layer 4 is directly laminated on the barrier layer 3, the resin components constituting the heat-sealable resin layer 4 can be coated on the barrier layer 3 of the laminate A by methods such as gravure coating method and roll coating method. In addition, when an adhesive layer 5 is provided between the barrier layer 3 and the heat-sealable resin layer 4, for example, the following methods can be cited: (1) A method of co-extruding and laminating the adhesive layer 5 and the heat-sealable resin layer 4 on the barrier layer 3 of the laminate A (co-extrusion lamination method); (2) Separately forming a laminate of the adhesive layer 5 and the heat-sealable resin layer 4, and laminating it on the barrier layer 3 of the laminate A by a thermal lamination method; (3) A method of laminating an adhesive for forming the adhesive layer 5 on the barrier layer 3 of the laminate A by an extrusion method or a method of drying at a high temperature and sintering after coating a solution, and then laminating a pre-fabricated sheet-like heat-sealable resin layer 4 on the adhesive layer 5 by a thermal lamination method; (4) A method of laminating the laminate A and the heat-sealable resin layer 4 through the adhesive layer 5 while flowing in the molten adhesive layer 5 between the barrier layer 3 of the laminate A and the pre-fabricated sheet-like heat-sealable resin layer 4 (interlayer lamination method).

[0209] When the surface covering layer 6 is provided, the surface covering layer 6 is laminated on the surface of the base material layer 1 opposite to the barrier layer 3. The surface covering layer 6 can be formed, for example, by coating the above resin for forming the surface covering layer 6 on the surface of the base material layer 1. Among them, the order of the process of laminating the barrier layer 3 on the surface of the base material layer 1 and the process of laminating the surface covering layer 6 on the surface of the base material layer 1 is not particularly limited. For example, the surface covering layer 6 can also be formed on the surface of the base material layer 1, and then the barrier layer 3 can be formed on the surface of the base material layer 1 opposite to the surface covering layer 6.

[0210] As described above, a laminate is formed which is composed of a surface covering layer 6 provided as required / a base material layer 1 / an adhesive layer 2 provided as required / a barrier layer 3 whose surface has been chemically surface-treated as required / an adhesive layer 5 provided as required / a heat-sealable resin layer 4. However, in order to make the adhesiveness of the adhesive layer 2 or the adhesive layer 5 firm, it can be further subjected to heat treatment such as hot roll contact type, hot air type, near-infrared type or far-infrared type. As the conditions for such heat treatment, for example, about 150 to 250 °C and about 1 to 5 minutes can be cited.

[0211] In the battery packaging material of the present invention, in order to improve or stabilize the film-forming property, lamination processing, adaptability to secondary processing (packaging, embossing) of the final product, etc. as required, surface activation treatments such as corona discharge treatment, sandblasting treatment, oxidation treatment, and ozone treatment can be performed on each layer constituting the laminate.

[0212] 4. Use of Packaging Material for Battery

[0213] The packaging material for batteries of the present invention can be used for a package that seals and houses battery components such as a positive electrode, a negative electrode, and an electrolyte. That is, by housing battery components having at least a positive electrode, a negative electrode, and an electrolyte in a package formed of the packaging material for batteries of the present invention, a battery can be produced.

[0214] Specifically, by using the packaging material for batteries of the present invention, a battery component having at least a positive electrode, a negative electrode, and an electrolyte is covered in a state where metal terminals respectively connected to the positive electrode and the negative electrode protrude outside, such that a flange portion (a region where heat-sealable resin layers contact each other) can be formed at the periphery of the battery component, and the heat-sealable resin layers of the flange portion are sealed to each other by heat sealing, whereby a battery using the packaging material for batteries can be provided. Here, when housing a battery component in a package formed of the packaging material for batteries of the present invention, the package is formed such that the heat-sealable resin portion of the packaging material for batteries of the present invention becomes the inner side (the surface in contact with the battery component).

[0215] The packaging material for batteries of the present invention can be used for any battery, such as a primary battery or a secondary battery, and is preferably used for secondary batteries. There is no particular limitation on the type of secondary battery to which the packaging material for batteries of the present invention can be applied. For example, a lithium ion battery, a lithium ion polymer battery, a lead storage battery, a nickel / hydrogen storage battery, a nickel / cadmium storage battery, a nickel / iron storage battery, a nickel / zinc storage battery, a silver oxide / zinc storage battery, a metal air battery, a multivalent cation battery, a condenser, a capacitor, etc. can be cited. Among these secondary batteries, a lithium ion battery and a lithium ion polymer battery can be cited as preferred application targets of the packaging material for batteries of the present invention.

[0216] Examples

[0217] The present invention will be described in detail below by way of examples and comparative examples. However, the present invention is not limited to the examples.

[0218] <Manufacture of Packaging Material for Batteries>

[0219] Each of the packaging materials for batteries of Examples 1 to 5 and Comparative Examples 1 to 3 was manufactured according to the following steps. The laminated structures of the respective packaging materials for batteries are shown in Table 1. In Table 1, SF represents a surface covering layer, ON represents a biaxially stretched nylon film, DL represents an adhesive layer or a bonding layer formed by a dry lamination method, AL represents an aluminum foil, PPa represents maleic anhydride-modified polypropylene, PP represents random polypropylene, and CPP represents an unstretched polypropylene film. In addition, the numerical value indicated after each layer represents the thickness of the layer. For example, "ON15" represents "a biaxially stretched nylon film with a thickness of 15 μm".

[0220] Example 1

[0221] By means of dry lamination, a barrier layer composed of aluminum foil (thickness 35 μm, JIS H4160: 1994 A8021H - O) with chemical surface treatment applied to both sides is laminated on a biaxially oriented nylon film (thickness 15 μm) serving as a base material layer. Specifically, a two - component polyurethane adhesive (polyol compound and aromatic isocyanate - based compound) is coated on one surface of the barrier layer to form an adhesive layer (thickness 3 μm) on the barrier layer. Then, the adhesive layer on the barrier layer and the base material layer are laminated to produce a laminate of the base material layer / adhesive layer / barrier layer. Among them, the chemical surface treatment of the aluminum foil used as the barrier layer is carried out by coating a treatment liquid composed of phenolic resin, chromium fluoride compound, and phosphoric acid on both sides of the aluminum foil by means of roll coating so that the coating amount of chromium reaches 10 mg / m 2 (dry mass), and then sintering is performed.

[0222] Next, maleic anhydride - modified polypropylene (thickness 20 μm, arranged on the barrier layer side) and random polypropylene (thickness 15 μm, innermost layer) are co - extruded on the barrier layer of the obtained laminate, thereby laminating an adhesive layer / a heat - fusible resin layer on the barrier layer. Then, the obtained laminate is heated at 175 °C for 2 minutes to obtain a battery packaging material in which the base material layer / adhesive layer / barrier layer / adhesive layer / heat - fusible resin layer are laminated in sequence.

[0223] Example 2

[0224] The same operation as in Example 1 is carried out to produce a laminate of the base material layer / adhesive layer / barrier layer. Then, a solution containing maleic anhydride - modified polypropylene and a curing agent (epoxy - based) (thickness 2 μm after curing) is coated on the barrier layer of the obtained laminate, and an unstretched polypropylene film (thickness 30 μm) is laminated thereon to obtain a battery packaging material in which the base material layer / adhesive layer / barrier layer / adhesive layer / heat - fusible resin layer are laminated in sequence.

[0225] Example 3

[0226] By the dry lamination method, a barrier layer composed of aluminum foil (thickness 35 μm, JIS H4160: 1994 A8021H - O) with chemical surface treatment on both sides is laminated on a biaxially stretched nylon film (thickness 15 μm) as the base material layer. Specifically, a two-component polyurethane adhesive (polyol compound and aromatic isocyanate compound) containing carbon black (median diameter 0.191 μm) is coated on one surface of the barrier layer to form an adhesive layer (thickness 3 μm) on the barrier layer. Then, after laminating the adhesive layer on the barrier layer and the base material layer, a curing treatment is carried out to produce a laminate of the base material layer / adhesive layer (black) / barrier layer. Among them, the chemical surface treatment of the aluminum foil used as the barrier layer is carried out in the same manner as in Example 1. In addition, the average particle diameter of the carbon black is the median diameter measured by a laser diffraction / scattering particle size distribution measuring device ("LA - 950" manufactured by Horiba, Ltd.).

[0227] Next, maleic anhydride-modified polypropylene (thickness 20 μm, arranged on the barrier layer side) and random polypropylene (thickness 15 μm, innermost layer) are co-extruded on the barrier layer of the obtained laminate, thereby laminating an adhesive layer / a heat-sealable resin layer on the barrier layer. Then, the obtained laminate is heated at 175 °C for 2 minutes to obtain a laminate in which the base material layer / adhesive layer / barrier layer / adhesive layer / heat-sealable resin layer are laminated in sequence. Next, by gravure coating, a resin composition containing sedimentary barium sulfate with an average particle diameter of 1 μm as a filler, erucamide, and acrylate resin with an average particle diameter of 2 μm is coated on the surface of the base material layer of the obtained laminate so that the dried thickness is about 3 μm to form a surface covering layer. Then, the obtained laminate is heated to obtain a battery packaging material in which the surface covering layer / base material layer / adhesive layer (black) / barrier layer / adhesive layer / heat-sealable resin layer are laminated in sequence. Among them, the average particle diameter of the sedimentary barium sulfate is the median diameter measured by a laser diffraction / scattering particle size distribution measuring device ("LA - 950" manufactured by Horiba, Ltd.).

[0228] Example 4

[0229] On one surface of a biaxially stretched nylon film (thickness: 15 μm) serving as a base material layer, a black pigment is printed to a thickness of 1 μm to form a black colored layer. Subsequently, by dry lamination, a barrier layer composed of an aluminum foil (thickness: 35 μm, JIS H4160: 1994 A8021H - O) with chemical surface treatment applied to both sides is laminated on the colored layer side of the base material layer. Specifically, a two - component polyurethane adhesive (a polyol compound and an aromatic isocyanate - based compound) is coated on one surface of the barrier layer to form an adhesive layer (thickness: 3 μm) on the barrier layer. Then, after laminating the adhesive layer on the barrier layer and the colored layer side of the base material layer, a curing treatment is performed to produce a laminate of the base material layer / colored layer (black) / adhesive layer / barrier layer. Herein, the chemical surface treatment of the aluminum foil used as the barrier layer is carried out in the same manner as in Example 1.

[0230] Subsequently, a two - component polyurethane adhesive (a polyol compound and an aromatic isocyanate - based compound) is coated on the barrier layer of the obtained laminate to form an adhesive layer (thickness: 3 μm) on the barrier layer. Then, an unstretched polypropylene film (thickness: 30 μm) is laminated on the adhesive layer. Next, the obtained laminate is heated and subjected to a curing treatment. Then, a resin composition containing a filler is coated on the surface of the base material layer of the obtained laminate to a thickness of 3 μm to form a surface covering layer. Next, the obtained laminate is heated and cured to obtain a battery packaging material in which the surface covering layer / base material layer / colored layer (black) / adhesive layer / barrier layer / adhesive layer / melt - bondable resin layer are laminated in sequence.

[0231] Example 5

[0232] By dry lamination, a barrier layer composed of an aluminum foil (thickness: 30 μm, JIS H4160: 1994 A8021H - O) with chemical surface treatment applied to both sides is laminated on a biaxially stretched nylon film (thickness: 15 μm) serving as a base material layer. Specifically, a two - component polyurethane adhesive (a polyol compound and an aromatic isocyanate - based compound) is coated on one surface of the barrier layer to form an adhesive layer (thickness: 3 μm) on the barrier layer. Then, the adhesive layer on the barrier layer and the base material layer are laminated to produce a laminate of the base material layer / adhesive layer / barrier layer. Herein, the chemical surface treatment of the aluminum foil used as the barrier layer is carried out in the same manner as in Example 1.

[0233] Next, on the barrier layer of the obtained laminate, maleic anhydride-modified polypropylene (thickness 14 μm, disposed on the barrier layer side) and random polypropylene (thickness 10 μm, innermost layer) were co-extruded, thereby laminating and bonding an adhesive layer / a heat-sealable resin layer on the barrier layer. Next, the obtained laminate was heated at 175 °C for 2 minutes to obtain a battery packaging material in which a base material layer / an adhesive layer / a barrier layer / an adhesive layer / a heat-sealable resin layer were laminated in sequence.

[0234] The wetting tension of the surface on the base material layer side of the laminate constituting the battery packaging material obtained in each example was within the range of 30 to 60 mN / m. The method for measuring the wetting tension is as follows.

[0235] <Method for Measuring Wetting Tension>

[0236] Using a wetting reagent specified by JIS standards, the wetting tension of the base material layer side of the laminate constituting the battery packaging material was measured. The test method follows JIS K6768:1999. Using a mixed solution for wetting tension test produced by NACALAI TESQUE, INC., the reagent contained in a cotton swab was coated in a line about 6 cm 2 long on the surface of the base material layer side of the battery packaging material. It was judged whether the liquid film broke after 2 seconds. In the case where the liquid film did not break, the next mixed solution with a higher surface tension was used. In the case where breakage occurred, the next mixed solution with a lower surface tension was used. This operation was repeated, and the mixed solution that wetted the surface of the test piece in 2 seconds was selected. Among them, the measurement of the wetting tension was carried out in an environment of 23 °C and a relative humidity of 50%.

[0237] Comparative Example 1

[0238] By a dry lamination method, a barrier layer composed of an aluminum foil (thickness 25 μm, JIS H4160:1994 A8021H - O) with chemical surface treatment on both sides was laminated on a polyethylene terephthalate film (thickness 12 μm) as the base material layer. Specifically, a two-component polyurethane adhesive (a polyol compound and an aromatic isocyanate compound) was coated on one surface of the barrier layer to form an adhesive layer (thickness 3 μm) on the barrier layer. Next, the adhesive layer on the barrier layer and the base material layer were laminated to produce a laminate of a base material layer / an adhesive layer / a barrier layer. Among them, the chemical surface treatment of the aluminum foil used as the barrier layer was carried out in the same manner as in Example 1.

[0239] Next, on the barrier layer of the obtained laminate, maleic anhydride-modified polypropylene (thickness 14 μm, disposed on the barrier layer side) and random polypropylene (thickness 10 μm, innermost layer) were co-extruded, thereby laminating an adhesive layer / a heat-sealable resin layer on the barrier layer. Next, the obtained laminate was heated at 175°C for 2 minutes, thereby obtaining a battery packaging material in which a base material layer / an adhesive layer / a barrier layer / an adhesive layer / a heat-sealable resin layer were laminated in sequence.

[0240] Comparative Example 2

[0241] In the same manner as in Comparative Example 1, a laminate of a base material layer / an adhesive layer / a barrier layer was produced. Next, a solution containing maleic anhydride-modified polypropylene and a curing agent (epoxy type) (thickness after curing 2 μm) was coated on the barrier layer of the obtained laminate, and an unstretched polypropylene film (thickness 25 μm) was laminated thereon, obtaining a battery packaging material in which a base material layer / an adhesive layer / a barrier layer / an adhesive layer / a heat-sealable resin layer were laminated in sequence.

[0242] Comparative Example 3

[0243] In the same manner as in Example 1, a laminate of a base material layer / an adhesive layer / a barrier layer was produced. The chemical surface treatment of the aluminum foil used as the barrier layer was carried out in the same manner as in Example 1. Next, on the barrier layer of the obtained laminate, maleic anhydride-modified polypropylene (thickness 20 μm, disposed on the barrier layer side) and random polypropylene (thickness 15 μm, innermost layer) were co-extruded, thereby laminating an adhesive layer / a heat-sealable resin layer on the barrier layer. Next, the obtained laminate was heated at 190°C for 2 minutes, thereby obtaining a battery packaging material in which a base material layer / an adhesive layer / a barrier layer / an adhesive layer / a heat-sealable resin layer were laminated in sequence.

[0244] [Table 1]

[0245] Laminated Structure of Packaging Material for Battery Example 1 ON15 / DL3 / AL35 / PPa20 / PP15 Example 2 ON15 / DL3 / AL35 / PPa2 / CPP30 Example 3 SF3 / ON15 / DL3 (black) / AL35 / PPa20 / PP15 Example 4 SF3 / ON15 / Coloring Layer 1 / DL3 / AL35 / DL3 / CPP30 Example 5 ON15 / DL3 / AL30 / PPa14 / PP10 Comparative Example 1 PET12 / DL3 / AL25 / PPa14 / PP10 Comparative Example 2 PET12 / DL3 / AL25 / PPa2 / CPP25 Comparative Example 3 ON15 / DL3 / AL35 / PPa20 / PP15

[0246] <Measurement of the thickness of the laminate>

[0247] The thickness of the laminate constituting each of the above-obtained battery packaging materials was measured using a micrometer (Digimatic Micrometer manufactured by Mitutoyo Corporation). The results are shown in Table 2.

[0248] <Fracture energy of the laminate>

[0249] The breaking energy per 1 m unit width in the MD and TD directions of each of the obtained battery packaging materials was calculated by obtaining the data of the "measured load (N / 15 mm) - displacement curve" measured during a tensile test under the following test conditions for the MD and TD directions of each battery packaging material, saving the data in a csv document format, and integrating the data up to the breakage of the laminate using spreadsheet software (Excel (registered trademark) of Microsoft Corporation). At this time, using this spreadsheet software, the data was converted (divided by 0.015) to calculate the breaking energy per 1 m width of each battery packaging material. Then, the breaking energy per 1 m unit width in the MD direction was summed with the breaking energy per 1 m unit width in the TD direction. Among them, 5 samples of each battery packaging material to be measured were prepared, and the average value of 3 values obtained by removing the maximum and minimum values from the breaking energy values of the 5 samples was used as the breaking energy of the laminate. The results are shown in Table 2.

[0250] (Test Conditions)

[0251] · Tensile testing machine: AGS-X Plus, manufactured by Shimadzu Corporation

[0252] · Test speed: 50 mm / min

[0253] · Width of test piece: 15 mm

[0254] · Length of test piece: 100 mm

[0255] · Distance between marks: 30 mm

[0256] Furthermore, for reference, the curve of the measured load (N / 15 mm) - displacement during the tensile test (MD) of the battery packaging material of Example 5 is shown in Figure 6 . The integrated part of the data of the measured load (N / 15 mm) - displacement curve, for example, as shown in the schematic diagram of Figure 7 , is the integrated value from the start of the tensile test (displacement is 0) to the break point P of the laminate, corresponding to the area of the slanted part of Figure 7 .

[0257] <Puncture Strength of Laminate>

[0258] For each of the above-obtained battery packaging materials, the puncture strength was measured from the substrate layer side according to the method specified in JIS Z1707:1995. Specifically, in a measurement environment of 23±2°C and a relative humidity of (50±5)%, the test piece was fixed using a stage with a diameter of 115 mm having an opening of 15 mm in the center and a pressing plate, and a semi-circular needle with a diameter of 1.0 mm and a tip shape radius of 0.5 mm was pierced through at a speed of 50±5 mm per minute, and the maximum stress until the needle penetrated was measured. The number of test pieces was 5, and the average value was obtained. Among them, as the puncture strength measurement device, ZTS-500N (force gauge) and MX-500N (measurement bracket) produced by Yimada Co., Ltd. were used. The results are shown in Table 2.

[0259] <Evaluation of formability>

[0260] Each battery packaging material was cut into a rectangle with a length (MD) of 90 mm × width (TD) of 150 mm as a test sample. For this sample, a rectangular forming die (female die, with a maximum height roughness (nominal value of Rz) of 3.2 μm as specified in Table 2 of the reference surface roughness standard sheet in Annex 1 of JIS B 0659-1:2002 on the surface) with a diameter of 32 mm (MD) × 54 mm (TD) and a corresponding forming die (male die, with a maximum height roughness (nominal value of Rz) of 1.6 μm as specified in Table 2 of the reference surface roughness standard sheet in Annex 1 of JIS B 0659-1:2002 on the surface) were used, and cold rolling forming (introducing one-stage forming) was performed on 20 samples each at a pressing pressure (surface pressure) of 0.25 MPa starting from a forming depth of 0.5 mm and changing the forming depth in units of 0.5 mm. At this time, the above test sample was placed on the female die with the heat-sealable resin layer side on the male die side for forming. In addition, the gap between the male die and the female die was set to 0.5 mm. In a dark room, a pen-shaped flashlight was used to irradiate the light on the cold-rolled formed sample, and through the transmission of light, it was confirmed whether pinholes or cracks occurred in the aluminum foil. The deepest forming depth at which no pinholes or cracks occurred in the aluminum foil among all 20 samples was set as Amm, the number of samples with pinholes or the like in the shallowest forming depth at which pinholes or the like occurred in the aluminum foil was set as B, and the value calculated by the following formula was used as the limit forming depth of the battery packaging material.

[0261] Limit forming depth = Amm + (0.5 mm / 20 pieces) × (20 pieces - B pieces)

[0262] [Table 2]

[0263]

[0264] It is known that the battery packaging materials of Examples 1 to 5, in which the thickness of the laminate constituting the battery packaging material is 100 μm or less and the sum of one direction and the other direction (the direction perpendicular to the one direction and the thickness direction of the laminate) of the fracture energy of the laminate in the direction perpendicular to the thickness direction of the laminate is 200 J or more, have excellent formability. Moreover, among these battery packaging materials, the puncture strength measured from the side of the base material layer 1 is also high.

[0265] Example 6

[0266] By the dry lamination method, a barrier layer composed of an aluminum foil (JIS H4160: 1994 A8021H - O, thickness 35 μm) having acid-resistant coatings formed on both sides is laminated on a biaxially stretched nylon film (thickness 25 μm) as the base material layer. Specifically, a two-component curable polyurethane adhesive (a polyol compound and an aromatic isocyanate compound) is coated on one surface of the aluminum foil having acid-resistant coatings formed on both sides to form an adhesive layer (thickness after curing 3 μm) on the aluminum foil. Then, after laminating the adhesive layer on the aluminum foil and the biaxially stretched nylon film, a curing treatment is carried out, whereby a laminate of the base material layer / adhesive layer / barrier layer is produced.

[0267] Next, maleic anhydride-modified polypropylene (thickness 14 μm) as the adhesive layer and polypropylene (thickness 10 μm) as the heat-sealable resin layer are co-extruded on the barrier layer of the obtained laminate, whereby the adhesive layer / heat-sealable resin layer is laminated on the barrier layer. Then, the obtained laminate is cured and heated, whereby a battery packaging material (total thickness 87 μm) in which a biaxially stretched nylon film (25 μm) / adhesive layer (3 μm) / barrier layer (35 μm) / adhesive layer (14 μm) / heat-sealable resin layer (10 μm) are laminated in sequence is obtained. The laminated structure of the battery packaging material is shown in Table 3.

[0268] Erucamide as a lubricant is made to exist on both sides of the obtained battery packaging material to form a lubricant layer.

[0269] Example 7

[0270] By a dry lamination method, a barrier layer composed of an aluminum foil (JIS H4160: 1994 A8021H - O, thickness 40 μm) with acid-resistant coatings formed on both sides is laminated on a biaxially oriented nylon film (thickness 25 μm) as a base material layer. Specifically, a two-component curable polyurethane adhesive (polyol compound and aromatic isocyanate compound) is coated on one surface of the aluminum foil with acid-resistant coatings formed on both sides to form an adhesive layer (cured thickness 2 μm) on the aluminum foil. Then, after laminating the adhesive layer on the aluminum foil and the biaxially oriented nylon film, a curing treatment is carried out to produce a laminate of the base material layer / adhesive layer / barrier layer.

[0271] Next, on the barrier layer of the obtained laminate, maleic anhydride-modified polypropylene (thickness 14 μm) as an adhesive layer and polypropylene (thickness 10 μm) as a heat-sealable resin layer are co-extruded, so that the adhesive layer / heat-sealable resin layer is laminated on the barrier layer. Then, the obtained laminate is cured and heated to obtain a battery packaging material (total thickness 91 μm) in which a biaxially oriented nylon film (25 μm) / adhesive layer (2 μm) / barrier layer (40 μm) / adhesive layer (14 μm) / heat-sealable resin layer (10 μm) are laminated in sequence. The laminated structure of the battery packaging material is shown in Table 3.

[0272] Similar to Example 6, erucamide as a lubricant is present on both sides of the obtained battery packaging material to form a lubricant layer.

[0273] Example 8

[0274] By a dry lamination method, a barrier layer composed of an aluminum foil (JIS H4160: 1994 A8021H - O, thickness 40 μm) with acid-resistant coatings formed on both sides is laminated on a biaxially oriented nylon film (thickness 15 μm) as a base material layer. Specifically, a two-component curable polyurethane adhesive (polyol compound and aromatic isocyanate compound) is coated on one surface of the aluminum foil with acid-resistant coatings formed on both sides to form an adhesive layer (cured thickness 3 μm) on the aluminum foil. Then, after laminating the adhesive layer on the aluminum foil and the biaxially oriented nylon film, a curing treatment is carried out to produce a laminate of the base material layer / adhesive layer / barrier layer.

[0275] Next, on the barrier layer of the obtained laminate, maleic anhydride-modified polypropylene (thickness 20 μm) as the adhesive layer and polypropylene (thickness 15 μm) as the heat-sealable resin layer were co-extruded, so that the adhesive layer / heat-sealable resin layer was laminated on the barrier layer. Next, the obtained laminate was cured and heated to obtain a battery packaging material (total thickness 93 μm) formed by laminating a biaxially stretched nylon film (15 μm) / adhesive layer (3 μm) / barrier layer (40 μm) / adhesive layer (20 μm) / heat-sealable resin layer (15 μm) in sequence. The laminated structure of the battery packaging material is shown in Table 3.

[0276] Similar to Example 6, erucamide as a lubricant was present on both surfaces of the obtained battery packaging material to form a lubricant layer.

[0277] Example 9

[0278] By the dry lamination method, a barrier layer composed of an aluminum foil (JIS H4160: 1994 A8021H-O, thickness 40 μm) with acid-resistant films formed on both sides was laminated on a biaxially stretched nylon film (thickness 15 μm) as the base material layer. Specifically, a two-component curable polyurethane adhesive (polyol compound and aromatic isocyanate compound) was coated on one surface of the aluminum foil with acid-resistant films formed on both sides to form an adhesive layer (cured thickness 3 μm) on the aluminum foil. Next, after laminating the adhesive layer on the aluminum foil and the biaxially stretched nylon film, a curing treatment was carried out to fabricate a laminate of the base material layer / adhesive layer / barrier layer.

[0279] Next, on the barrier layer of the obtained laminate, maleic anhydride-modified polypropylene (thickness 14 μm) as the adhesive layer and polypropylene (thickness 10 μm) as the heat-sealable resin layer were co-extruded, so that the adhesive layer / heat-sealable resin layer was laminated on the barrier layer. Next, the obtained laminate was cured and heated to obtain a battery packaging material (total thickness 82 μm) formed by laminating a biaxially stretched nylon film (15 μm) / adhesive layer (3 μm) / barrier layer (40 μm) / adhesive layer (14 μm) / heat-sealable resin layer (10 μm) in sequence. The laminated structure of the battery packaging material is shown in Table 3.

[0280] Similar to Example 6, erucamide as a lubricant was present on both surfaces of the obtained battery packaging material to form a lubricant layer.

[0281] [Table 3]

[0282] Laminated Structure of Packaging Material for Battery Example 6 ONy25 / DL3 / ALM35 / PPa14 / PP10 Example 7 ONy25 / DL2 / ALM40 / PPa14 / PP10 Example 8 ONy15 / DL3 / ALM40 / PPa20 / PP15 Example 9 ONy15 / DL3 / ALM40 / PPa14 / PP10

[0283] In Table 3, the numerical values in the laminate structure represent thickness (μm). Additionally, ONy represents a biaxially stretched nylon film, DL represents an adhesive layer or bonding layer formed by dry lamination, ALM represents aluminum foil, PPa represents an adhesive layer formed from maleic anhydride-modified polypropylene, PP represents a heat-sealable resin layer formed from polypropylene, and CPP represents a heat-sealable resin layer formed from unstretched polypropylene (CPP).

[0284] <Measurement of the Thickness of the Laminate>

[0285] In the same manner as in Examples 1 to 5 and Comparative Examples 1 to 3, the thicknesses of the laminates constituting each battery packaging material obtained in Examples 6 to 9 were measured. The results are shown in Table 4.

[0286] <Puncture Strength of the Laminate>

[0287] In the same manner as in Examples 1 to 5 and Comparative Examples 1 to 3, for each battery packaging material obtained in Examples 6 to 9, the puncture strength was measured from the substrate layer side according to the method specified in JIS Z1707:1995. The results are shown in Table 4.

[0288] <Fracture Energy of Laminate>

[0289] For each battery packaging material obtained in Examples 6 to 9, in the same manner as in Examples 1 to 5 and Comparative Examples 1 to 3, the fracture energy of the laminate was measured. The results are shown in Table 4.

[0290] <Evaluation of the Curling Caused by Molding>

[0291] Cut the battery packaging materials obtained in Examples 6 to 9 to make rectangular pieces with a size of TD (Transverse Direction: vertical direction) 150 mm × MD (Machine Direction: machine direction) 90 mm, and use them as test samples. Use a mold composed of a male mold with a rectangle of 31.6 mm × 54.5 mm (the maximum height roughness (nominal value of Rz) specified in Table 2 of the reference surface roughness standard sheet in Annex 1 of JIS B 0659-1:2002 for the surface is 1.6 μm, the corner is R2.0 mm, and the edge line is R1.0 mm), and a female mold with a gap of 0.3 mm from the male mold (the maximum height roughness (nominal value of Rz) specified in Table 2 of the reference surface roughness standard sheet in Annex 1 of JIS B 0659-1:2002 for the surface is 3.2 μm, the corner is R2.0 mm, and the edge line is R1.0 mm). Place the above test sample on the female mold with the heat-sealable resin layer side on the male mold side, and press the test sample with a pressing pressure (surface pressure) of 0.25 MPa to reach 31.6 mm (MD) × 54.5 mm (TD) and a forming depth of 6 mm for cold rolling forming (introducing one-stage forming). The details of the forming position are as Figure 8 shown. As Figure 8 shown, forming is carried out at a position where the shortest distance d between the rectangular forming part M and the end P of the battery packaging material 10 is 70.5 mm. The forming part M indicates the position where a concave part is formed by the mold. Then, place the formed battery packaging material 10 as Figure 9 shown on the horizontal plane 20, and take the maximum value t of the distance in the vertical direction y from the horizontal plane 20 to the end P as the maximum height of the part where curling occurs. The smaller the curling value caused by forming, the less curling, and the better it is as a battery packaging material. The results are shown in Table 4.

[0292] <Evaluation of formability>

[0293] For each battery packaging material obtained in Examples 6 to 9, perform the same operations as in Examples 1 to 5 and Comparative Examples 1 to 3 to evaluate the formability. The results are shown in Table 4.

[0294] <Forming depth when the thickness of the barrier layer reaches 20 μm>

[0295] The packaging materials for each battery obtained in Examples 6 to 9 were cut to produce rectangular sheets with a length (MD) of 90 mm × width (TD) of 150 mm, which were used as test samples. A smooth mold composed of a male mold with a rectangle of length (MD) 31.6 mm × width (TD) 54.5 mm (the maximum height roughness (nominal value of Rz) specified in Table 2 of the reference surface roughness standard sheet in Annex 1 of JIS B0659-1:2002 for the surface is 1.6 μm, with a corner R of 2.0 mm and an edge line R of 1.0 mm) and a female mold with a clearance of 0.3 mm from the male mold (the maximum height roughness (nominal value of Rz) specified in Table 2 of the reference surface roughness standard sheet in Annex 1 of JIS B 0659-1:2002 for the surface is 3.2 μm, with a corner R of 2.0 mm and an edge line R of 1.0 mm) was used. The above test sample was placed on the female mold with the heat-sealable resin layer side on the male mold side, and the test sample was pressed with a pressing pressure (surface pressure) of 0.25 MPa for cold rolling forming (one-stage forming).

[0296] By this cold rolling forming method, forming was successively carried out under the condition that the forming depth increased by 0.5 mm starting from 2.0 mm. The thickness a of the corner P of the barrier layer of the formed test sample was plotted (refer to Figure 9 ) against the forming depth, an approximate straight line was drawn, and a graph was made. According to this graph, the forming depth at which the thickness a of the corner P of the barrier layer reached 20 μm was obtained.

[0297] The thickness a of the barrier layer of the formed test sample was measured as follows: When looking at the test sample from the substrate layer side, on the straight line connecting the opposite corners P of the portion protruding in a substantially rectangular shape, it was cut in the thickness direction using a microtome (REM-710 RETORATOME produced by Daiwa Koki Kogyo Co., Ltd.) to divide the battery packaging material into two. The thickness a of the barrier layer was measured by observing the cross-section of the above corner P of one of the divided test samples using a laser microscope (VK-9700 produced by KEYENCE). There were 2 such corners in one of the divided test samples, and the thickness a of the barrier layer was the average value of the thickness a of the barrier layer at these corners. A schematic diagram of the barrier layer of the formed test sample is shown in Figure 10 . Among them, regarding the position of the thickness of the corner P, at the corner P (bending part) formed by forming, it is the place with the smallest radius of curvature, and generally represents the central part from the start to the end of the bending.

[0298] [Table 4]

[0299]

[0300] Symbol Explanation

[0301] 1: Substrate layer; 2: Adhesive layer; 3: Barrier layer; 4: Heat-sealable resin layer; 5: Adhesive layer; 6: Surface covering layer; 7: Coloring layer.

Claims

1. A packaging material for a battery, characterized in that: it is composed of a laminate having at least a substrate layer, a barrier layer, and a heat-sealable resin layer in sequence, a surface covering layer is further provided on the side of the substrate layer opposite to the barrier layer, the substrate layer is formed of polyamide, and the thickness of the substrate layer is 20 μm or less, the barrier layer is formed of aluminum alloy, and the thickness of the barrier layer is 50 μm or less, the thickness of the laminate is 100 μm or less, the laminate has a puncture strength of 22 N or less measured from the substrate layer side according to the method specified in JIS Z1707:1995, the wetting tension of the surface on the substrate layer side of the laminate is 30 to 60 mN / m, the sum X + Y of the fracture energy X and the fracture energy Y of the laminate is 200 J or more and 500 J or less, where the fracture energy is the fracture energy per unit width of 1 m calculated from the curve of the measured load (N / 15 mm) - displacement amount during a tensile test under the following test conditions. The fracture energy X is the fracture energy in one direction perpendicular to the thickness direction of the laminate, and the fracture energy Y is the fracture energy in the other direction perpendicular to both the one direction and the thickness direction of the laminate, (Test conditions) Test speed: 50 mm / min; Width of test piece: 15 mm; Distance between punctuation marks: 30 mm.

2. The packaging material for a battery according to claim 1, characterized in that: the one direction is the MD of the laminate, and the other direction is the TD of the laminate.

3. The packaging material for a battery according to claim 1 or 2, characterized in that: the laminate has a puncture strength of 15 N or more measured from the substrate layer side according to the method specified in JIS Z1707:1995.

4. The packaging material for a battery according to any one of claims 1 to 3, characterized in that: an adhesive layer is provided between the substrate layer and the barrier layer.

5. The packaging material for a battery according to claim 4, characterized in that: the adhesive layer contains a colorant.

6. The packaging material for a battery according to claim 4 or 5, characterized in that: a colored layer is provided between the substrate layer and the adhesive layer.

7. The packaging material for a battery according to any one of claims 1 to 6, characterized in that: two or more kinds of lubricants are present on the surface of the substrate layer.

8. The packaging material for a battery according to any one of claims 1 to 7, characterized in that: at least one selected from saturated fatty acid amides, unsaturated fatty acid amides, substituted amides, hydroxymethyl amides, saturated fatty acid bisamides, unsaturated fatty acid bisamides, fatty acid ester amides, and aromatic bisamides is present on the surface of the substrate layer.

9. The packaging material for a battery according to any one of claims 1 to 8, characterized in that: a lubricant is present in the heat-sealable resin layer.

10. The packaging material for a battery according to any one of claims 1 to 9, characterized in that: The hot-melt resin layer contains at least one selected from saturated fatty acid amides, unsaturated fatty acid amides, substituted amides, hydroxymethyl amides, saturated fatty acid bisamides, unsaturated fatty acid bisamides, fatty acid ester amides, and aromatic bisamides.

11. The battery packaging material according to any one of claims 1 to 10, characterized in that: At least one of the surface and the interior of the surface covering layer contains a lubricant.

12. The battery packaging material according to any one of claims 1 to 10, characterized in that: At least one of the surface and the interior of the surface covering layer contains two or more lubricants.

13. The battery packaging material according to any one of claims 1 to 10, characterized in that: At least one of the surface and the interior of the surface covering layer contains at least one selected from amide-based lubricants, fatty acid amides, metal soaps, hydrophilic silicones, acrylics grafted with silicone, epoxies grafted with silicone, polyethers grafted with silicone, polyesters grafted with silicone, block-type silicone acrylate copolymers, polyglycerol-modified silicones, paraffins, and reactive lubricants.

14. A method for manufacturing a battery packaging material, characterized in that: It includes a step of obtaining a laminate by laminating at least a base material layer, a barrier layer, and a hot-melt resin layer in sequence, The side of the base material layer opposite to the barrier layer further has a surface covering layer, The base material layer is formed of polyamide, and the thickness of the base material layer is 20 μm or less, The barrier layer is formed of aluminum alloy, and the thickness of the barrier layer is 50 μm or less, The thickness of the laminate is 100 μm or less, The puncture strength of the laminate measured from the side of the base material layer according to the method specified in JIS Z1707:1995 is 22 N or less, The wetting tension of the surface on the base material layer side of the laminate is 30 to 60 mN / m, The sum X + Y of the fracture energy X and the fracture energy Y of the laminate is 200 J or more and 500 J or less. Here, the fracture energy is the fracture energy per unit width of 1 m calculated from the curve of the measured load (N / 15 mm) - displacement amount during a tensile test under the following test conditions. The fracture energy X is the fracture energy in one direction perpendicular to the thickness direction of the laminate, and the fracture energy Y is the fracture energy in the other direction perpendicular to both the one direction and the thickness direction of the laminate. (Test conditions) Test speed: 50 mm / min; Width of the test piece: 15 mm; Distance between punctuation marks: 30 mm.

15. The method for manufacturing a battery packaging material according to claim 14, characterized in that: There is an adhesive layer between the barrier layer and the hot-melt resin layer, The adhesive layer and the hot-melt resin layer are formed by the following method (1), (2), (3), or (4). (1) A method of co-extruding and laminating the adhesive layer and the hot-melt resin layer; (2) A method of forming a laminate formed by laminating the adhesive layer and the hot-melt resin layer, and laminating this laminate on the barrier layer by a thermal lamination method; (3) A method of laminating an adhesive for forming the adhesive layer on the barrier layer by an extrusion method, or by drying at a high temperature after coating a solution and then sintering, and then laminating the heat-fusible resin layer pre-formed into a sheet on the adhesive layer by a thermal lamination method; (4) A method of laminating the heat-fusible resin layer by flowing the molten adhesive layer between the barrier layer and the heat-fusible resin layer pre-formed into a sheet and bonding the heat-fusible resin layer through the adhesive layer.

16. The method for manufacturing a battery packaging material according to claim 14 or 15, characterized in that: The heat-fusible resin layer is formed of two or more layers of the same or different resins.

17. A battery, characterized in that: A battery element having 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 claims 1 to 13.

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