CN110998893B

CN110998893B - Packaging material for battery and battery

Info

Publication number: CN110998893B
Application number: CN201880054445.4A
Authority: CN
Inventors: 中村真一郎; 安田大佑; 藤原亮; 山下孝典; 山下力也
Original assignee: Dai Nippon Printing Co Ltd
Current assignee: Dai Nippon Printing Co Ltd
Priority date: 2017-08-23
Filing date: 2018-08-22
Publication date: 2023-11-28
Anticipated expiration: 2038-08-22
Also published as: JP7136108B2; JPWO2019039505A1; WO2019039505A1; CN110998893A

Abstract

A packaging material for a battery comprising a laminate having at least a base layer, a barrier layer and a heat-fusible resin layer in this order, wherein the thickness of the laminate constituting the packaging material for a battery and the thickness of the barrier layer are both small, and the packaging material for a battery has a predetermined moldability, and when a masking tape stuck to the surface on the base layer side is peeled off, the packaging material for a battery is less likely to be carried away by the masking tape, and the formation of wrinkles can be effectively suppressed. The packaging material for a battery is composed of a laminate having at least a base layer, a barrier layer and a heat-fusible resin layer in this order, wherein the thickness of the laminate is 50 [ mu ] m to 120 [ mu ] m, the thickness of the barrier layer is 15 [ mu ] m to 40 [ mu ] m, and the flexural rigidity of the laminate is 0.60gf cm ² 6.0gf cm or more per cm ² And/cm or less.

Description

Packaging material for battery and battery

Technical Field

The present invention relates to a packaging material for a battery and a battery.

Background

Various types of batteries have been developed, and in all of the batteries, a packaging material is an indispensable component for sealing battery elements such as electrodes and electrolytes. In the related art, a metal packaging material is often used as a packaging material for a battery.

On the other hand, in recent years, with the increase in performance of electric vehicles, hybrid electric vehicles, computers, cameras, mobile phones, and the like, batteries are demanded to have various shapes, and further, thinning and lightening are demanded. However, the metal battery packaging materials used in the prior art have a drawback in that it is difficult to cope with the shape diversification, and the weight reduction is also limited.

In recent years, as a packaging material for a battery which can be easily processed into various shapes and can be thinned and lightened, a film-like laminate in which a base material layer, a barrier layer, and a heat-fusible resin layer are laminated in this order has been proposed (for example, refer to patent document 1).

In such a battery packaging material, a recess is generally formed by cold rolling, battery elements such as a battery and an electrolyte are disposed in a space formed by the recess, and heat-sealable resin layers are heat-sealed to each other, thereby obtaining a battery in which the battery elements are housed inside the battery packaging material.

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open No. 2008-287971

Disclosure of Invention

Technical problem to be solved by the invention

In recent years, with the demand for miniaturization and thinning of batteries, further thinning of battery packaging materials is also required. However, when the battery packaging material is thinned, the barrier layer is also thinned, and there is a problem that cracks or pinholes are likely to occur during molding, and moldability is lowered.

In addition, in the process of manufacturing a battery, a masking tape may be attached to the surface of the battery (i.e., the surface of a battery packaging material in which a battery element is sealed) and peeled off before the battery is used, from the viewpoint of preventing the surface of the battery from being discolored due to the adhesion of an electrolyte and causing scratches on the surface of the battery. However, if the thickness of the battery packaging material or the barrier layer is reduced, the battery packaging material is easily carried away by the masking tape and wrinkles are formed on the surface of the battery when the masking tape is peeled off from the surface of the battery, and a gap may be formed between the packaging material and the battery composed of the positive electrode, the separator, and the negative electrode due to the wrinkles. Therefore, the electrolyte may move from the battery to the void, which may cause degradation of the battery performance, and the void may be formed, so that the packaging material may contact the battery when the battery is vibrated, and the heat-fusible resin layer of the packaging material may be damaged, which may cause corrosion.

Under such circumstances, a main object of the present invention is to provide a packaging material for a battery, which is composed of a laminate having at least a base material layer, a barrier layer and a heat-fusible resin layer in this order, and which has a predetermined moldability even though the thickness of the laminate constituting the packaging material for a battery and the thickness of the barrier layer are thin, and which is less likely to be carried away by the masking tape when the masking tape stuck to the surface on the base material layer side is peeled off, and which can effectively suppress the formation of wrinkles.

Technical means for solving the technical problems

The inventors of the present invention have conducted intensive studies in order to solve the above-mentioned technical problems. The result shows that: the laminate is composed of a laminate having at least a base layer, a barrier layer and a heat-fusible resin layer in this order, and has a thickness of 50 [ mu ] m to 120 [ mu ] m, a thickness of 15 [ mu ] m to 40 [ mu ] m, and a flexural rigidity of 0.60gf cm ² 6.0gf cm or more per cm ² The battery packaging material of/cm or less has a predetermined moldability even though the thickness of the laminate constituting the battery packaging material and the thickness of the barrier layer are small, and when the masking tape stuck on the surface of the base material layer side is peeled off, the battery packaging material is not easily carried away by the masking tape, and the formation of wrinkles can be effectively suppressed.

The present invention has been completed based on these findings and further repeated studies.

That is, the present invention provides the following aspects of the invention.

A packaging material for a battery comprising a laminate having at least a base layer, a barrier layer and a heat-fusible resin layer in this order,

the thickness of the laminate is 50 μm to 120 μm,

the thickness of the barrier layer is 15 μm to 40 μm,

The bending rigidity of the laminate was 0.60gf cm ² 6.0gf cm or more per cm ² And/cm or less.

The battery packaging material according to item 1, wherein the barrier layer is made of an aluminum alloy foil or a stainless steel foil.

The battery packaging material according to item 1 or 2, wherein the surface of the base material layer opposite to the barrier layer further comprises a surface coating layer containing an additive.

The battery packaging material according to any one of items 1 to 3, wherein the thickness of the base material layer is 25 μm or less.

The battery packaging material according to any one of items 1 to 4, wherein the battery packaging material is produced by a method according to JIS Z1707: the puncture strength measured by the method specified in 1997 when the laminate is punctured from the substrate layer side is 5N to 55N.

The battery packaging material according to any one of items 1 to 5, wherein the battery packaging material is produced by a method according to JIS K7127: the tensile modulus of the laminate in the direction perpendicular to the lamination direction, measured by the method defined in 1999, is 3.0GPa to 10.0 GPa.

The battery packaging material according to any one of items 1 to 6, wherein the heat-fusible resin layer contains polyolefin.

The battery packaging material according to any one of items 1 to 7, wherein the base material layer contains at least one of a polyester resin and a polyamide resin.

The battery according to item 9, wherein a battery element including at least a positive electrode, a negative electrode, and an electrolyte is housed in the package formed of the battery packaging material according to any one of items 1 to 8.

Effects of the invention

The invention provides a packaging material for a battery, which is composed of a laminate body at least comprising a base material layer, a barrier layer and a heat-weldable resin layer in sequence, has prescribed formability even though the thickness of the laminate body and the thickness of the barrier layer composing the packaging material for a battery are very thin, and is not easy to be taken away by the masking tape when the masking tape stuck on the surface of the base material layer side is peeled off, thereby effectively inhibiting the formation of wrinkles. Further, according to the present invention, there are provided a method for producing the battery packaging material and a battery using the battery packaging material.

Drawings

Fig. 1 is a view showing an example of a cross-sectional structure of a battery packaging material according to the present invention.

Fig. 2 is a view showing an example of a cross-sectional structure of the battery packaging material of the present invention.

Fig. 3 is a view showing an example of a cross-sectional structure of the battery packaging material of the present invention.

Fig. 4 is a view showing an example of a cross-sectional structure of the battery packaging material of the present invention.

Fig. 5 is a schematic diagram for explaining an evaluation method of the tape peelability of the example.

Detailed Description

The packaging material for a battery of the present invention is characterized by comprising a laminate having at least a base layer, a barrier layer and a heat-fusible resin layer in this order, wherein the laminate has a thickness of 50 [ mu ] m to 120 [ mu ] m, the barrier layer has a thickness of 15 [ mu ] m to 40 [ mu ] m, and the laminate has a flexural rigidity of 0.60gf cm ² 6.0gf cm or more per cm ² And/cm or less. The battery packaging material of the present invention has such a structure that the thickness of the laminate constituting the battery packaging material and the thickness of the barrier layer are both small, and the battery packaging material has a predetermined moldability, and when the masking tape stuck to the surface of the base material layer side is peeled off, the battery packaging material is less likely to be carried away by the masking tape, and the formation of wrinkles can be effectively suppressed. The battery packaging material of the present invention will be described in detail below.

In the present specification, the numerical range indicated by "to" means "above" and "below". For example, the expression 2 to 15mm means 2mm to 15 mm.

1. Laminate structure and physical properties of battery packaging material

As shown in fig. 1, for example, the battery packaging material 10 of the present invention is composed of a laminate having at least a base material layer 1, a barrier layer 3, and a heat-fusible resin layer 4 in this order. In the battery packaging material of the present invention, the base material layer 1 is the outermost layer, and the heat-fusible resin layer 4 is the innermost layer. That is, when the battery is assembled, the battery element is sealed by thermally fusing the thermally fusible resin layers 4 located at the periphery of the battery element to each other, thereby packaging the battery element.

As shown in fig. 2 to 4, for example, the battery packaging material 10 of the present invention may have an adhesive layer 2 between the base material layer 1 and the barrier layer 3. As shown in fig. 3 and 4, for example, an adhesive layer 5 may be provided between the barrier layer 3 and the heat-fusible resin layer 4. As shown in fig. 4, the substrate layer 1 may have a surface coating layer 6 on the outer side (the side opposite to the heat-fusible resin layer 4) as required.

The thickness of the laminate constituting the battery packaging material 10 of the present invention is in the range of 50 to 120. Mu.m. As described above, the battery packaging material 10 of the present invention is extremely thin, and thus the energy density of the battery can be improved. As described above, the battery packaging material 10 of the present invention can exhibit a predetermined moldability by setting the bending stiffness of the laminate within a specific range, although the thickness is extremely thin, and when the masking tape is stuck to the surface on the substrate layer side, the battery packaging material is less likely to be carried away by the masking tape when the masking tape is peeled off, and the formation of wrinkles can be effectively suppressed.

The thickness of the laminate constituting the battery pack 10 of the present invention is not particularly limited as long as it is within the above range, and from the viewpoint of reducing the thickness of the battery pack, exhibiting a predetermined moldability, and suppressing wrinkles formed by peeling off the masking tape, the lower limit is preferably about 55 μm or more, more preferably about 60 μm or more, and the upper limit is preferably about 115 μm or less, more preferably about 90 μm or less, about 80 μm or less, about 75 μm or less, or about 70 μm or less. Preferable ranges of the thickness of the laminate include about 50 to 115. Mu.m, about 50 to 90. Mu.m, about 50 to 80. Mu.m, about 50 to 75. Mu.m, about 50 to 70. Mu.m, about 55 to 120. Mu.m, about 55 to 115. Mu.m, about 55 to 90. Mu.m, about 55 to 80. Mu.m, about 55 to 75. Mu.m, about 55 to 70. Mu.m, about 60 to 120. Mu.m, about 60 to 115. Mu.m, about 60 to 90. Mu.m, about 60 to 80. Mu.m, about 60 to 75. Mu.m, and about 60 to 70. Mu.m. The thickness of the laminate constituting the battery packaging material 10 can be measured by a commercially available thickness measuring instrument.

The laminate constituting the battery packaging material 10 of the present invention has a flexural rigidity of 0.60 to 6.0gf cm ² In the range of/cm. As described above, the battery packaging material 10 of the present invention, although having a very thin thickness, can exhibit a predetermined moldability by setting the bending stiffness of the laminate within such a specific range, and when the masking tape is attached to the surface on the substrate layer side, the battery packaging material is less likely to be carried away by the masking tape when the masking tape is peeled off, and the formation of wrinkles can be effectively suppressed.

The bending rigidity of the laminate constituting the battery packaging material 10 of the present invention is within the above range, and from the viewpoints of reducing the thickness of the battery packaging material, exhibiting a predetermined moldability, and suppressing wrinkles formed by peeling off the masking tape, a lower limit of the bending rigidity is preferably about 0.65gf cm ² Preferably not less than/cm, more preferably about 0.70gf cm ² Preferably not less than/cm, more preferably about 0.80gf cm ² As the upper limit, it is preferable to set about 5.00gf cm or more ² Less than or equal to 1.60gf cm ² Less than or equal to 1.55gf cm ² And/cm or less. As a preferable range of the bending rigidity, there can be mentioned 0.60 to 5.00gf cm ² About 0.60 to 1.60gf cm ² About 0.60 to 1.55gf cm ² About 0.65 to 6.00gf cm ² About 0.65 to 5.00gf cm ² About 0.65 to 1.60gf cm ² About 0.65 to 1.55gf cm ² About 0.70 to 6.00gf cm ² About 0.70 to 5.00gf cm ² About 0.70 to 1.60gf cm ² About 0.70 to 1.55gf cm ² About 0.80 to 6.00gf cm ² About/cmRight, 0.80-5.00 gf cm ² About 0.80 to 1.60gf cm per cm ² About 0.80 to 1.55gf cm ² About/cm.

The flexural rigidity of the laminate constituting the battery packaging material 10 can be adjusted by, for example, the thickness, composition, and the like of the layers constituting the laminate.

In the present invention, the flexural rigidity of the laminate constituting the battery packaging material 10 is measured as follows. Specifically, the measurement can be performed according to the method described in examples.

< determination of flexural rigidity >

A test sample was obtained by cutting a battery packaging material into a rectangular shape of Cheng Kuandu (direction perpendicular to the flow direction in film formation: TD) and a length (flow direction in film formation: MD) of 80 mm. For the obtained test sample, the flexural rigidity (gf cm) was measured using a commercially available flexural rigidity measuring machine ² /cm). The measurement conditions were such that the curvature change rate was set to 0.1/cm.sec, the jig interval was set to 1cm, and the maximum curvature was set to 2.5cm ^-1 The average value of the flexural rigidity for 10 test samples was used as the flexural rigidity of the battery packaging material. The test specimen was fixed to 2 jigs so that the end edge of the width of 80mm was aligned with the jig axis direction.

The passage of the laminate constituting the battery pack 10 of the present invention is in accordance with JIS Z1707 from the viewpoint of reducing the thickness of the battery pack, exhibiting a predetermined moldability, and suppressing wrinkles formed by peeling off the masking tape: the puncture strength measured by the method described in 1997 at the time of puncture from the substrate layer side is preferably in the range of 5 to 55N, more preferably in the range of 5 to 40N, and even more preferably in the range of 14 to 40N.

In the present invention, the puncture strength of the laminate constituting the battery packaging material 10 is measured as follows. Specifically, the measurement can be performed according to the method described in examples.

< determination of puncture Strength >

The puncture strength from the base layer side of the laminate constituting the battery packaging material was measured in accordance with JIS Z1707: 1997. Specifically, under a measuring environment of 23.+ -. 2 ℃ and relative humidity (50.+ -. 5)%, a test piece was fixed by a 115mm diameter table having an opening of 15mm in the center and a pressing plate, and a semicircular needle having a diameter of 1.0mm and a tip shape radius of 0.5mm was penetrated at a speed of 50.+ -. 5mm per minute, and the maximum stress until penetration of the needle was measured. The number of test pieces was 5, and the average value was obtained. If the number of test pieces is less than 5, the number of test pieces that can be measured is measured, and an average value is obtained.

In addition, from the viewpoints of reducing the thickness of the battery packaging material, exhibiting a predetermined moldability, and suppressing wrinkles formed by peeling off the masking tape, the laminate constituting the battery packaging material 10 of the present invention is produced by the method according to JIS K7127: the tensile modulus measured by the method specified in 1999 in the direction perpendicular to the lamination direction of the laminate is preferably in the range of 3.0 to 10.0GPa, more preferably in the range of 3.8 to 9.5 GPa.

In the present invention, the method for measuring the tensile modulus of the laminate constituting the battery packaging material 10 is as follows. Specifically, the measurement can be performed according to the method described in examples.

< determination of tensile modulus >)

The battery packaging material was cut into a rectangular shape of Cheng Kuandu mm and 100mm in length to obtain a test sample. Next, according to JIS K7127:1999, the tensile modulus was calculated by stretching the test specimen under conditions where the distance between the gauge lines was 30mm and the stretching speed was 50 mm/min. The length of the test sample may be not 100mm as long as the test can be performed under the above-described measurement conditions.

Examples of masking tapes include adhesive tapes using a rubber component, an acrylic component, a urethane component, a silicone component, and a styrene-isoprene block copolymer (SIS) component as an adhesive component, and commercially available adhesive tapes are readily available.

2. Layers forming a battery packaging material

[ substrate layer 1]

In the battery packaging material of the present invention, the base material layer 1 is a layer located on the outermost layer side. The material for forming the base material layer 1 is not particularly limited as long as it is a material having insulating properties. Examples of the material for forming the base layer 1 include resin films of polyester resins, polyamide resins, epoxy resins, acrylic resins, fluorine-containing resins, polyurethane resins, silicon-containing resins, phenolic resins, polycarbonates, and mixtures and copolymers thereof. Among these, polyester resins and polyamide resins are preferable, and biaxially stretched polyester resins and biaxially stretched polyamide resins are more preferable. Specific examples of the polyester resin include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, and copolyesters. Specific examples of the polyamide resin include nylon 6, nylon 66, a copolymer of nylon 6 and nylon 66, nylon 6,10, and poly (m-xylylene adipamide) (MXD 6).

The base material layer 1 preferably contains at least one of a polyester resin and a polyamide resin.

The base material layer 1 may be formed of 1 resin film, but may be formed of 2 or more resin films in order to improve pinhole resistance and insulation. Specifically, a multilayer structure in which a polyester film and a nylon film are laminated, a multilayer structure in which a plurality of nylon films are laminated, a multilayer structure in which a plurality of polyester films are laminated, and the like are cited. When the base material layer 1 has a multilayer structure, it is preferably a laminate of biaxially stretched nylon film and biaxially stretched polyester film, a laminate obtained by laminating a plurality of biaxially stretched nylon films, or a laminate obtained by laminating a plurality of biaxially stretched polyester films. For example, in the case where the base material layer 1 is formed of 2 resin films, it is preferable to form a structure in which a polyester resin is laminated with a polyester resin, a structure in which a polyamide resin is laminated with a polyamide resin, or a structure in which a polyester resin is laminated with a polyamide resin, and more preferable is a structure in which polyethylene terephthalate is laminated with polyethylene terephthalate, a structure in which nylon is laminated with nylon, or a structure in which polyethylene terephthalate is laminated with nylon. In addition, in this laminated structure, it is preferable to laminate the base material layer 1 such that the polyester resin is positioned in the outermost layer, for example, because the polyester resin is less likely to be discolored when the electrolyte is adhered to the surface. When the base material layer 1 has a multilayer structure, the thickness of each layer is preferably about 2 to 10 μm.

When the base material layer 1 is formed of a plurality of resin films, 2 or more resin films may be laminated with an adhesive component such as an adhesive or an adhesive resin, and the kind and amount of the adhesive component used are the same as those of the adhesive layer 2 described later. Among them, the method of laminating 2 or more resin films is not particularly limited, and known methods may be used, and examples thereof include a dry lamination method, a sandwich lamination method, and the like, and a dry lamination method is preferable. When the lamination is performed by a dry lamination method, a polyurethane adhesive is preferably used as the adhesive layer. In this case, the thickness of the adhesive layer may be, for example, about 2 to 5. Mu.m. In addition, when the base material layer 1 is formed of a multilayer resin film, the portion of the adhesive does not contribute substantially to moldability and the like, and is therefore not included in the thickness of the base material layer 1.

In the present invention, from the viewpoint of improving the moldability of the battery packaging material, the surface of the base material layer 1 is preferably adhered with a lubricant. The lubricant is not particularly limited, and an amide-based lubricant is preferably used. Specific examples of the amide-based lubricant include amide-based lubricants similar to those exemplified in the heat-fusible resin layer 4 described later.

In the case where the lubricant is present on the surface of the base material layer 1, the amount thereof is not particularly limited, and about 3mg/m is preferably exemplified in an environment having a temperature of 24℃and a relative humidity of 60% ² The above is more preferably 4 to 15mg/m ² About, more preferably 5 to 14mg/m ² Left and right.

The base material layer 1 may contain a lubricant. The lubricant present on the surface of the base material layer 1 may be formed by bleeding out the lubricant contained in the resin constituting the base material layer 1, or may be formed by applying the lubricant to the surface of the base material layer 1.

The thickness of the base material layer 1 is not particularly limited as long as it can function as a base material, and from the viewpoints of reducing the thickness of the battery packaging material, exhibiting a predetermined moldability, and suppressing wrinkles formed by peeling the masking tape, the upper limit is preferably 15 μm or less, more preferably 10 μm or less, and the lower limit is preferably about 3 μm or more, more preferably about 4 μm or more. The preferable range of the base material layer 1 is about 3 to 15. Mu.m, about 3 to 10. Mu.m, about 4 to 15. Mu.m, and about 4 to 10. Mu.m.

In particular, from the viewpoint of reducing the thickness of the battery packaging material, exhibiting a predetermined moldability, and suppressing wrinkles caused by peeling off the masking tape, it is preferable that the base layer 1 is formed of a polyethylene terephthalate film having a thickness of about 3 to 10 μm.

[ adhesive layer 2]

In the battery packaging material 10 of the present invention, the adhesive layer 2 is a layer provided between the base material layer 1 and the barrier layer 3 as needed to firmly adhere them.

The adhesive layer 2 is formed of an adhesive capable of adhering the base material layer 1 to the barrier layer 3. The adhesive used for forming the adhesive layer 2 may be a two-part curing adhesive or a one-part curing adhesive. The bonding mechanism of the adhesive used for forming the adhesive layer 2 is not particularly limited, and may be any type such as a chemical reaction type, a solvent evaporation type, a hot melt type, a hot press type, or the like.

Specific examples of the adhesive component that can be used to form the adhesive layer 2 include polyester resins such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, polycarbonate, and copolyester; a polyether-based adhesive; a polyurethane adhesive; an epoxy resin; phenolic resin; polyamide resins such as nylon 6, nylon 66, nylon 12 and copolyamide; polyolefin resins such as polyolefin, carboxylic acid-modified polyolefin and metal-modified polyolefin, and polyvinyl acetate resins; a cellulose-based adhesive; (meth) acrylic resins; polyimide resin; amino resins such as urea resin and melamine resin; chloroprene rubber, nitrile rubber, styrene-butadiene rubber, and other rubbers; silicone resins, and the like. These adhesive components may be used alone or in combination of at least 2 kinds. Among these adhesive components, a polyurethane adhesive is preferable.

The adhesive layer 2 may contain a colorant. The adhesive layer 2 contains a colorant, so that the battery packaging material can be colored. As the colorant, known colorants such as pigments and dyes can be used. Further, the colorant may be used in an amount of 1 or 2 or more.

For example, carbon black, titanium oxide, and the like are preferable as specific examples of the inorganic pigment. Specific examples of the organic pigment include azo pigments, phthalocyanine pigments, and condensed ring pigments. Examples of the azo pigment include soluble pigments such as wobbe red and carmine 6C; insoluble azo pigments such as monoazo yellow, disazo yellow, parlazob Long Cheng (Pyrazolone Orange), parlazob Long Gong, and permanent red. Examples of the phthalocyanine pigment include copper phthalocyanine pigments, and blue pigments and green pigments which are metal-free phthalocyanine pigments. Examples of the condensed ring system pigment include dioxazine violet and quinacridone violet. As the pigment, a pearlescent pigment, a fluorescent pigment, or the like can be used.

Among the colorants, carbon black is preferable, for example, when the appearance of the battery packaging material is black.

The average particle diameter of the pigment is not particularly limited, and examples thereof include about 0.05 to 5. Mu.m, preferably about 0.08 to 2. Mu.m. Wherein the average particle diameter of the pigment is the median diameter measured by a laser diffraction/scattering type particle diameter distribution measuring device.

The content of the pigment in the adhesive layer 2 is not particularly limited as long as the battery packaging material can be colored, and for example, about 5 to 60 mass% is included.

A coloring layer may be provided between the base material layer 1 and the adhesive layer 2. The colored layer can be formed, for example, by applying an ink containing a colorant to the surface of the base material layer 1. As the colorant, known colorants such as pigments and dyes can be used. Further, the colorant may be used in an amount of 1 or 2 or more. Specific examples of the colorant contained in the colored layer include the same colorants as exemplified above. The ink for forming the colored layer is not particularly limited, and a known ink can be used. Specific examples of the ink include inks containing a colorant, a diamine, a polyol, and a curing agent. The solvent contained in the ink may be any known solvent, and examples thereof include toluene.

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

[ Barrier layer 3]

In the battery packaging material, the barrier layer 3 is a layer that has a function of improving the strength of the battery packaging material and preventing intrusion of water vapor, oxygen, light, and the like into the battery. The barrier layer 3 is preferably a metal layer, i.e. a layer formed of metal. The metal constituting the barrier layer 3 may be specifically an aluminum alloy foil, a stainless steel foil, titanium, or the like, and preferably an aluminum alloy foil or a stainless steel foil. In the production of the battery packaging material, the barrier layer is more preferably formed of a soft aluminum alloy foil such as an annealed aluminum alloy foil (JIS H4160:1994A8021H-O, JIS H4160:1994A8079H-O, JIS H4000:2014A8021P-O, JIS H4000:2014A 8079P-O) or the like, from the viewpoint of preventing wrinkles or pinholes from occurring in the barrier layer 3.

Examples of the stainless steel foil include austenitic stainless steel foil and ferritic stainless steel foil. In the present invention, from the viewpoint of being able to provide a battery packaging material that has high rigidity, is less likely to form wrinkles when the tape is peeled, and has excellent formability, it is preferable that the stainless steel foil 3 is made of austenitic stainless steel. Specific examples of austenitic stainless steel constituting the stainless steel foil 3 include SUS304, SUS301, and SUS316L, among which SUS304 is particularly preferred from the viewpoint of obtaining a battery packaging material having high puncture strength and excellent electrolyte resistance and moldability.

The thickness of the barrier layer 3 is in the range of 15 to 40 μm. In the battery packaging material 10 of the present invention, not only the thickness of the battery packaging material but also the thickness of the barrier layer is small, but also the bending rigidity of the laminate is set within a specific range, whereby a predetermined moldability can be exhibited, and when the masking tape is adhered to the surface on the base material layer side, the battery packaging material is less likely to be carried away by the masking tape when the masking tape is peeled off, and the formation of wrinkles can be effectively suppressed. The lower limit of the thickness of the barrier layer 3 is preferably about 20 μm or more, and the upper limit is preferably about 40 μm or less, more preferably 35 μm or less, from the viewpoints of reducing the thickness of the battery packaging material, exhibiting a predetermined moldability, and suppressing wrinkles caused by peeling the masking tape, and the preferred range of the thickness of the barrier layer 3 is about 15 to 35 μm, about 20 to 35 μm, about 15 to 30 μm, or about 20 to 30 μm. More specifically, when the barrier layer 3 is made of, for example, a stainless steel foil, the lower limit of the thickness of the barrier layer 3 is preferably about 15 μm or more, the upper limit is preferably about 40 μm or less, and the preferred range of the thickness is about 15 to 40 μm, about 15 to 35 μm, or about 15 to 25 μm. In the case where the barrier layer 3 is made of, for example, an aluminum alloy foil, the lower limit of the thickness of the barrier layer 3 is preferably about 20 μm or more, more preferably about 25 μm or more, and the upper limit is about 40 μm or less, and the preferred range of the thickness is about 20 to 40 μm, about 20 to 35 μm, about 20 to 30 μm, about 25 to 35 μm, or about 25 to 30 μm.

In addition, the barrier layer 3 is preferably subjected to a chemical surface treatment on at least one surface, more preferably both surfaces, for stabilization of adhesion, prevention of dissolution or corrosion, and the like. Here, the chemical surface treatment means a treatment of forming an acid-resistant film on the surface of the barrier layer. Examples of the chemical surface treatment include: chromate treatments using chromium compounds such as chromium nitrate, chromium fluoride, chromium sulfate, chromium acetate, chromium oxalate, chromium dihydrogen phosphate, acetoacetate chromate, chromium chloride, and potassium chromium sulfate; phosphoric acid treatment using a phosphoric acid compound such as sodium phosphate, potassium phosphate, ammonium phosphate, or polyphosphoric acid; chromating or the like using an aminated phenol polymer having a repeating unit represented by the following general formulae (1) to (4). In the above-mentioned aminophenol polymer, 1 or 2 or more kinds of repeating units represented by the following general formulae (1) to (4) may be contained singly or in any combination.

In the general formulae (1) to (4), X represents a hydrogen atom, a hydroxyl group, an alkyl group, a hydroxyalkyl group, an allyl group or a benzyl group. In addition, R ¹ And R is ² Respectively, are the same or different and represent hydroxyl, alkyl or hydroxyalkyl. In the general formulae (1) to (4), X, R is ¹ And R is ² Examples of the alkyl group include straight-chain or branched alkyl groups having 1 to 4 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and tert-butyl. In addition, as X, R ¹ And R is ² Examples of the hydroxyalkyl group include straight-chain or branched alkyl groups having 1 to 4 carbon atoms, in which 1 hydroxyl group is substituted, such as hydroxymethyl, 1-hydroxyethyl, 2-hydroxyethyl, 1-hydroxypropyl, 2-hydroxypropyl, 3-hydroxypropyl, 1-hydroxybutyl, 2-hydroxybutyl, 3-hydroxybutyl, and 4-hydroxybutyl groups. X, R in the general formulae (1) to (4) ¹ And R is ² The alkyl and hydroxyalkyl groups shown may be the same or different, respectively. In the general formulae (1) to (4), X is preferably a hydrogen atom, a hydroxyl group or a hydroxyalkyl group. The number average molecular weight of the aminated phenol polymer having the repeating units represented by the general formulae (1) to (4) is, for example, preferably about 500 to 100 ten thousand, more preferably about 1000 to 2 ten thousand.

Further, as a chemical surface treatment method for imparting corrosion resistance to the barrier layer 3, the following method can be mentioned: a method in which a material in which fine particles of a metal oxide such as aluminum oxide, titanium oxide, cerium oxide, tin oxide, or barium sulfate are dispersed in phosphoric acid is applied, and the material is subjected to a sintering treatment at 150 ℃ 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 may be further formed on the acid-resistant film. Examples of the cationic polymer include polyethyleneimine, an ionic polymer complex composed of polyethyleneimine and a polymer having a carboxylic acid, a primary amine-grafted acrylic resin in which a primary amine is graft-polymerized on an acrylic main skeleton, polyallylamine or a derivative thereof, aminophenol, and the like. As these cationic polymers, only 1 kind may be used, or 2 or more kinds may be used in combination. Examples of the crosslinking agent include a compound having at least one functional group selected from the group consisting of an isocyanate group, a glycidyl group, a carboxyl group and an oxazoline group, a silane coupling agent, and the like. As these crosslinking agents, only 1 kind may be used, or 2 or more kinds may be used in combination.

As a specific method for providing the acid-resistant film, for example, a treatment solution (aqueous solution) containing a chromium phosphate salt, a titanium phosphate salt, a zirconium phosphate salt, a zinc phosphate salt, or a mixture of these metal salts as a main component, a treatment solution (aqueous solution) containing a non-metal phosphate salt and a mixture of these non-metal salts as a main component, or a treatment solution (aqueous solution) containing a mixture of these non-metal salts and an aqueous synthetic resin such as an acrylic resin, a phenolic resin, or a urethane resin is applied to the degreased surface by a known application method such as a roll coating method, a gravure printing method, or a dipping method. For example, when the treatment is performed with a chromium phosphate-based treatment liquid, an acid-resistant film composed of chromium phosphate, aluminum oxide, aluminum hydroxide, aluminum fluoride, or the like is obtained; when the treatment is performed with a zinc phosphate-based treatment liquid, an acid-resistant film composed of zinc phosphate hydrate, aluminum phosphate, aluminum oxide, aluminum hydroxide, aluminum fluoride, or the like is obtained.

As another example of a specific method for providing the acid-resistant film, for example, a known treatment method such as an alkali dipping method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method, or an acid activation method is used to degrease at least the inner layer side surface of the aluminum alloy foil, and then a known anodic oxidation treatment is performed on the degreased surface, whereby the acid-resistant film can be formed.

Further, as another example of the acid-resistant film, a phosphate-based film and a chromic acid-based film can be given. Examples of the phosphate include zinc phosphate, iron phosphate, manganese phosphate, calcium phosphate, and chromium phosphate, and examples of the chromic acid include chromium chromate.

As another example of the acid-resistant film, the following effects can be exhibited by forming an acid-resistant film of a phosphate, chromate, fluoride, triazinethiol compound, or the like: preventing delamination between aluminum and a substrate layer during embossing; preventing dissolution and corrosion of aluminum surfaces, particularly dissolution and corrosion of aluminum oxide existing on aluminum surfaces, caused by hydrogen fluoride generated by reaction of an electrolyte with moisture; and improves the adhesiveness (wettability) of the aluminum surface; preventing delamination of the substrate layer from the aluminum during thermal welding; preventing delamination of the substrate layer from the aluminum during the embossing type press forming. Among the materials forming the acid-resistant film, it is preferable to apply an aqueous solution composed of three components of a phenolic resin, a chromium (III) fluoride compound, and phosphoric acid to the aluminum surface and dry and sinter the same.

The acid-resistant film includes a layer including cerium oxide, phosphoric acid or phosphate, an anionic polymer, and a crosslinking agent that crosslinks the anionic polymer, and the phosphoric acid or phosphate may be blended in an amount of about 1 to 100 parts by mass relative to 100 parts by mass of the cerium oxide. The acid-resistant film is preferably a multilayer structure further comprising a layer having a cationic polymer and a crosslinking agent that crosslinks the cationic polymer.

The anionic polymer is preferably poly (meth) acrylic acid or a salt thereof, or a copolymer containing (meth) acrylic acid or a salt thereof as a main component. The crosslinking agent is preferably at least 1 selected from the group consisting of a compound having any functional group of an isocyanate group, a glycidyl group, a carboxyl group, and an oxazoline group, and a silane coupling agent.

The phosphoric acid or phosphate is preferably a condensed phosphoric acid or a condensed phosphate.

The chemical surface treatment may be performed by 1 kind of chemical surface treatment, or may be performed by 2 kinds or more of chemical surface treatments in combination. These chemical surface treatments may be carried out using 1 kind of compound alone or 2 or more kinds of compounds in combination. Among the chemical surface treatments, a chemical surface treatment combining a chromate treatment, a chromium compound, a phosphoric acid compound, and an aminated phenol polymer is preferable. Among the chromium compounds, chromic acid compounds are preferable.

Specific examples of the acid-resistant film include films containing at least one of phosphate, chromate, fluoride, and triazinethiol. In addition, an acid-resistant film containing a cerium compound is also preferable. As the cerium compound, cerium oxide is preferable.

Specific examples of the acid-resistant film include phosphate-based films, chromate-based films, fluoride-based films, and triazine thiol compound films. The acid-resistant film may be 1 kind of the above-mentioned film, or may be a combination of plural kinds. The acid-resistant film may be formed by degreasing the chemically treated surface of the aluminum alloy foil, and then using a treatment liquid comprising a mixture of a metal phosphate and an aqueous synthetic resin, or a treatment liquid comprising a mixture of a non-metal phosphate and an aqueous synthetic resin.

Among them, the composition analysis of the acid-resistant film can be performed by using time-of-flight type 2-ion mass spectrometry, for example. By composition analysis of the acid-resistant film using time-of-flight type 2 nd ion mass spectrometry, for example, ce was detected ⁺ And Cr (V) ⁺ At least one peak of (a) is present.

The aluminum alloy foil or the stainless steel foil preferably has an acid-resistant film containing at least 1 element selected from the group consisting of phosphorus, chromium and cerium on the surface thereof. Wherein, the acid-resistant film on the surface of the aluminum alloy foil or the stainless steel foil of the packaging material for the battery contains at least 1 element selected from phosphorus, chromium and cerium, and can be confirmed by X-ray photoelectron spectroscopy. Specifically, first, in the battery packaging material, a heat-fusible resin layer, an adhesive layer, or the like laminated on an aluminum alloy foil or a stainless steel foil is physically peeled off. Next, the aluminum alloy foil or the stainless steel foil was placed in an electric furnace, and the organic components present on the surface of the aluminum alloy foil or the stainless steel foil were removed at about 300℃for about 30 minutes. Then, the inclusion of these elements was confirmed by X-ray photoelectron spectroscopy of the surface of the aluminum alloy foil or stainless steel foil.

The amount of the acid-resistant film formed on the surface of the barrier layer 3 by the chemical surface treatment is not particularly limited, and for example, in the case of performing the above-mentioned chromate treatment, the surface of the barrier layer 3 is formed every 1m ² On the surface, the content of the chromium compound is preferably about 0.5 to 50mg, preferably about 1.0 to 40mg, in terms of chromium, and the content of the phosphorus compound is preferably about 0.5 to 50mg, preferably about 1.0 to 40mg, in terms of phosphorus, and the content of the aminophenol polymer is preferably about 1.0 to 200mg, preferably about 5.0 to 150 mg.

The thickness of the acid-resistant film is not particularly limited, but is preferably about 1nm to 10 μm, more preferably about 1 to 100nm, and even more preferably about 1 to 50nm, from the viewpoints of the film aggregation force and the adhesion force between the barrier layer 3 and the heat-sealing resin layer. The thickness of the acid-resistant film can be measured by observation with a transmission electron microscope or by a combination of observation with a transmission electron microscope and an energy-dispersive X-ray spectrometry or an electron-ray energy loss spectrometry.

The chemical surface treatment may be performed as follows: the solution containing the compound for forming the acid-resistant film is applied to the surface of the barrier layer by a bar coating method, a roll coating method, a gravure coating method, a dipping method, or the like, and then the barrier layer is heated to a temperature of about 70 to 200 ℃. The barrier layer may be subjected to degreasing treatment by an alkali dipping method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method, or the like, before being subjected to chemical surface treatment. By performing such degreasing treatment, chemical surface treatment of the barrier layer surface can be performed more efficiently.

[ Heat-fusible resin layer 4]

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

The resin component used for the heat-fusible resin layer 4 is not particularly limited as long as it can be heat-fused, and examples thereof include polyolefin, cyclic polyolefin, acid-modified polyolefin, and acid-modified cyclic polyolefin. That is, the resin constituting the heat-fusible resin layer 4 may contain a polyolefin skeleton, and preferably contains a polyolefin skeleton. The resin constituting the heat-fusible resin layer 4 contains a polyolefin skeleton and can be analyzed by, for example, infrared spectrometry, gas chromatography mass spectrometry, or the like, and the analysis method is not particularly limited. For example, when the maleic anhydride-modified polyolefin is measured by infrared spectrometry, the measurement is carried out at a wave number of 1760cm ^-1 Nearby sum wave number 1780cm ^-1 The vicinity of the peak from maleic anhydride was detected. However, when the degree of acid modification is low, the peak may be small and undetectable. In this case, analysis can be performed by nuclear magnetic resonance spectroscopy.

Specific examples of the polyolefin include: polyethylene such as low density polyethylene, medium density polyethylene, high density polyethylene and linear low density polyethylene; polypropylene such as homopolypropylene, a block copolymer of polypropylene (e.g., a block copolymer of propylene and ethylene), and a random copolymer of polypropylene (e.g., a random copolymer of propylene and ethylene); ethylene-butene-propylene terpolymers, and the like. Among these polyolefins, polyethylene and polypropylene are preferably cited.

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

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

The acid-modified cyclic polyolefin means: a polymer obtained by copolymerizing an α, β -unsaturated carboxylic acid or an anhydride thereof with a part of a monomer constituting a cyclic polyolefin, or by block polymerizing or graft polymerizing an α, β -unsaturated carboxylic acid or an anhydride thereof with a cyclic polyolefin. The carboxylic acid-modified cyclic polyolefin is the same as described above. The carboxylic acid used for the modification is the same as the acid component used for the modification of the polyolefin.

Among these resin components, polyolefin such as polypropylene and carboxylic acid-modified polyolefin are preferable; more preferably, polypropylene and acrylic modified polypropylene are exemplified.

The heat-fusible resin layer 4 may be formed of 1 resin component alone or a polymer blend in which 2 or more resin components are combined. The heat-fusible resin layer 4 may be formed of only 1 layer, or may be formed of 2 or more layers of the same or different resin components.

In the present invention, from the viewpoint of improving the moldability of the battery packaging material, the surface of the heat-fusible resin layer is preferably adhered with a lubricant. The lubricant is not particularly limited, and an amide-based lubricant is preferably used. Specific examples of the amide-based lubricant include saturated fatty acid amides, unsaturated fatty acid amides, substituted amides, methylolamides, saturated fatty acid bisamides, and unsaturated fatty acid bisamides. Specific examples of the saturated fatty acid amide include lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, and hydroxystearic acid amide. Specific examples of the unsaturated fatty acid amide include oleic acid amide and erucic acid amide. Specific examples of the substituted amide include N-oleyl palmitoyl amide, N-stearyl stearoyl amide, N-stearyl oleamide, N-oleyl stearoyl amide, and N-stearyl erucic amide. Specific examples of the methylol amide include methylol stearic acid amide and the like. Specific examples of the saturated fatty acid bisamide include methylene bisstearamide, ethylene bisdecanoamide, ethylene bislauramide, ethylene bisstearamide, ethylene bishydroxystearamide, ethylene bisbehenamide, hexamethylenebisstearamide, hexamethylenebisbehenamide, hexamethylenehydroxystearamide, N '-distearyl adipic acid amide, and N, N' -distearyl sebacic acid amide. Specific examples of the unsaturated fatty acid bisamide include ethylene bis-oleamide, ethylene bis-erucamide, hexamethylene bis-oleamide, N '-dioleyladipamide, and N, N' -dioleylsebacamide. Specific examples of the fatty acid ester amide include stearamide ethyl stearate and the like. Specific examples of the aromatic bisamide include m-xylylene bisstearamide, m-xylylene bishydroxystearamide, and N, N' -distearyl isophthalic acid amide. The lubricant may be used alone or in combination of 1 or more than 2.

When the lubricant is present on the surface of the heat-fusible resin layer 4, the amount thereof is not particularly limited, and is preferably about 3mg/m in an environment having a temperature of 24℃and a relative humidity of 60% ² The above is more preferably 4 to 15mg/m ² About, more preferably 5 to 14mg/m ² Left and right.

The heat-fusible resin layer 4 may contain a lubricant. The lubricant present on the surface of the heat-fusible resin layer 4 may be formed by bleeding out the lubricant contained in the resin constituting the heat-fusible resin layer 4, or may be formed by applying the lubricant to the surface of the heat-fusible resin layer 4.

The thickness of the heat-fusible resin layer 4 is not particularly limited as long as the function as a heat-fusible resin layer can be exhibited, and the lower limit is preferably about 8 μm or more, more preferably about 10 μm or more, and the upper limit is preferably about 30 μm or less, more preferably about 25 μm or less, from the viewpoints of reducing the thickness of the battery packaging material, exhibiting a predetermined moldability, and suppressing wrinkles formed by peeling the masking tape. Preferable ranges of the thickness of the heat-fusible resin layer include about 8 to 30. Mu.m, about 8 to 25. Mu.m, about 10 to 30. Mu.m, and about 10 to 25. Mu.m.

[ adhesive layer 5]

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-fusible resin layer 4 as needed to firmly adhere them.

The adhesive layer 5 is formed of a resin capable of adhering the barrier layer 3 to the heat-fusible resin layer 4. As the resin used for forming the adhesive layer 5, an adhesive similar to the adhesive exemplified in the adhesive layer 2, such as an adhesive mechanism and a kind of an adhesive component, can be used. As the resin used for forming the adhesive layer 5, polyolefin resins such as polyolefin, cyclic polyolefin, carboxylic acid-modified polyolefin, and carboxylic acid-modified cyclic polyolefin exemplified in the heat-fusible resin layer 4 can be used. From the viewpoint of excellent adhesion between the barrier layer 3 and the heat-fusible resin layer 4, the polyolefin is preferably a carboxylic acid-modified polyolefin, and particularly preferably a carboxylic acid-modified polypropylene. That is, the resin constituting the adhesive layer 5 may contain a polyolefin skeleton, and preferably contains a polyolefin skeleton. The resin constituting the adhesive layer 5 includes a polyolefin skeleton and can be analyzed by, for example, infrared spectrometry, gas chromatography mass spectrometry, or the like, and the analysis method is not particularly limited. For example, when measuring maleic anhydride-modified polyolefin by infrared spectrometry, the measurement is carried out at a wave number of 1760cm ^-1 Nearby sum wave number 1780cm ^-1 The vicinity of the peak from maleic anhydride was detected. However, when the degree of acid modification is low, the peak may be small and undetectable. In this case, analysis can be performed by nuclear magnetic resonance spectroscopy.

In addition, from the viewpoint of reducing the thickness of the battery packaging material and making a battery packaging material excellent in shape stability after molding, the adhesive layer 5 is also preferably a cured product of a resin composition containing an acid-modified polyolefin and a curing agent. The acid-modified polyolefin is preferably the same as the carboxylic acid-modified polyolefin and the carboxylic acid-modified cyclic polyolefin exemplified in the heat-fusible resin layer 4.

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

The epoxy curing agent is not particularly limited as long as it is a compound having at least 1 epoxy group. Examples of the epoxy curing agent include epoxy resins such as bisphenol a diglycidyl ether, modified bisphenol a diglycidyl ether, novolac glycidyl ether, glycerol polyglycidyl ether, and polyglycidyl ether.

The polyfunctional isocyanate-based curing agent is not particularly limited as long as it is a compound having 2 or more isocyanate groups. Specific examples of the polyfunctional isocyanate curing agent include isophorone diisocyanate (IPDI), hexamethylene Diisocyanate (HDI), toluene Diisocyanate (TDI), diphenylmethane diisocyanate (MDI), a polymer obtained by polymerizing or urethanizing them, a mixture of these, and a copolymer of these and other polymers.

The carbodiimide-based curing agent is not particularly limited as long as it is a compound having at least 1 carbodiimide group (-n=c=n-). As the carbodiimide-based curing agent, a polycarbodiimide compound having at least 2 carbodiimide groups is preferable.

The oxazoline-based curing agent is not particularly limited as long as it is a compound having an oxazoline skeleton. As the oxazoline-based curing agent, there may be specifically mentioned EPOCROS series produced by Japanese catalyst of Kagaku Co., ltd.

The curing agent may be composed of 2 or more compounds from the viewpoint of improving the adhesion between the barrier layer 3 and the heat-fusible resin layer 4 by the adhesive layer 5.

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 even more preferably in the range of about 0.1 to 10% by mass.

The thickness of the adhesive layer 5 is not particularly limited as long as the function as an adhesive layer can be exhibited, and in the case of using the adhesive exemplified in the adhesive layer 2, it is preferably about 1 to 10 μm, more preferably about 1 to 5 μm. In the case of using the resin exemplified in the heat-fusible resin layer 4, the resin is preferably about 2 to 25 μm, more preferably about 10 to 20 μm. In the case of a cured product of an acid-modified polyolefin and a curing agent, the thickness is preferably about 10 μm or less, more preferably about 0.1 to 10. Mu.m, and still more preferably about 0.5 to 5. Mu.m. When the adhesive layer 5 is a cured product of a resin composition containing an acid-modified polyolefin and a curing agent, the adhesive layer 5 can be formed by applying the resin composition and curing the composition by heating or the like.

[ surface coating 6]

In the battery packaging material of the present invention, the surface coating layer 6 may 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 in order to improve design properties, electrolyte resistance, scratch resistance, moldability, and the like. The surface coating layer 6 is a layer located at the outermost layer when the battery is assembled.

The surface coating layer 6 may be formed of polyvinylidene chloride, polyester resin, polyurethane resin, acrylic resin, epoxy resin, or the like, for example. Of these, the surface coating layer 6 is more preferably formed of a two-part curable resin. Examples of the two-part curable resin for forming the surface coating layer 6 include two-part curable urethane resins, two-part curable polyester resins, and two-part curable epoxy resins. Further, an additive may be blended in the surface coating layer 6.

Examples of the additive include fine particles having a particle diameter of about 0.5nm to 5. Mu.m. The material of the additive is not particularly limited, and examples thereof include metals, metal oxides, inorganic substances, organic substances, and the like. The shape of the additive is not particularly limited, and examples thereof include spherical, fibrous, plate-like, amorphous, and hollow spherical. Specific examples of the additives include talc, silica, graphite, kaolin, montmorillonite, synthetic mica, hydrotalcite, silica gel, zeolite, aluminum hydroxide, magnesium hydroxide, zinc oxide, magnesium oxide, aluminum oxide, neodymium oxide, antimony oxide, titanium oxide, cerium oxide, calcium sulfate, barium sulfate, calcium carbonate, calcium silicate, lithium carbonate, calcium benzoate, calcium oxalate, magnesium stearate, aluminum oxide, carbon black, carbon nanotubes, high-melting nylon, crosslinked acrylic acid, crosslinked styrene, crosslinked polyoxyethylene, benzoguanamine, gold, aluminum, copper, nickel, and the like. These additives may be used alone or in combination of 1 or more than 2. Among these additives, silica, barium sulfate, and titanium oxide are preferable from the viewpoints of dispersion stability, cost, and the like. Various surface treatments such as an insulating treatment and a high dispersibility treatment may be applied to the surface of the additive.

The content of the additive in the surface coating layer is not particularly limited, but is preferably about 0.05 to 1.0 mass%, and more preferably about 0.1 to 0.5 mass%.

The method for forming the surface coating layer 6 is not particularly limited, and examples thereof include a method of applying a two-component curable resin for forming the surface coating layer 6 to one surface of the base material layer 1. In the case of blending the additive, the additive may be added to the two-part curable resin, and the mixture may be mixed and then applied.

The thickness of the surface coating layer 6 is not particularly limited as long as the above-described function as the surface coating layer 6 can be exhibited, and examples thereof include about 0.5 to 10 μm, preferably about 1 to 5 μm.

3. Method for manufacturing packaging material for battery

The method for producing the battery packaging material of the present invention is not particularly limited as long as a laminate of laminated layers having a predetermined composition can be obtained.

As an example of the method for producing the battery packaging material of the present invention, the following method can be used. 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 this order is formed. The laminate a can be formed by a dry lamination method in which an adhesive for forming the adhesive layer 2 is applied to the base material layer 1 or, if necessary, the barrier layer 3 having a surface chemically treated, by a coating method such as a gravure coating method or a roll coating method, and then dried, and then the adhesive layer 2 is cured by laminating the barrier layer 3 or the base material layer 1.

Next, an adhesive layer 5 and a heat-fusible resin layer 4 are sequentially laminated on the barrier layer 3 of the laminate a. For example, the following methods may be mentioned: (1) A method of laminating the adhesive layer 5 and the heat-fusible resin layer 4 by coextrusion on the barrier layer 3 of the laminate a (coextrusion lamination method); (2) A method of forming a laminate of the adhesive layer 5 and the heat-fusible resin layer 4 and laminating the laminate on the barrier layer 3 of the laminate a by a heat lamination method; (3) A method in which an adhesive for forming the adhesive layer 5 is laminated on the barrier layer 3 of the laminate a by an extrusion method, a method in which the adhesive layer is dried at a high temperature after the solution is applied, and then a thermally fusible resin layer 4 which is formed into a sheet in advance is laminated on the adhesive layer 5 by a thermal lamination method; (4) A method (sandwich lamination method) in which the laminate a and the heat-fusible resin layer 4 are bonded to each other through the adhesive layer 5 while flowing into the molten adhesive layer 5 between the barrier layer 3 of the laminate a and the heat-fusible resin layer 4 formed into a sheet in advance.

When the surface coating layer 6 is provided, the surface coating layer 6 is laminated on the surface of the base material layer 1 opposite to the barrier layer 3. The surface coating layer 6 can be formed by, for example, coating the resin forming the surface coating layer 6 on the surface of the base material layer 1. The order of the step of laminating the barrier layer 3 on the surface of the base material layer 1 and the step of laminating the surface coating layer 6 on the surface of the base material layer 1 is not particularly limited. For example, after the surface coating layer 6 is formed on the surface of the base material layer 1, the barrier layer 3 may be formed on the surface of the base material layer 1 opposite to the surface coating layer 6.

As described above, the laminate composed of the surface coating layer 6, the base material layer 1, the adhesive layer 2, and the barrier layer 3, the adhesive layer 5, and the heat-fusible resin layer 4, which are provided as needed, and the surface of which is subjected to a chemical process as needed, is formed, but the laminate may be further subjected to a heat treatment such as a heat roller contact type, a hot air type, a near infrared ray type, or a far infrared ray type in order to secure the adhesion of the adhesive layer 2 or the adhesive layer 5. The conditions for such heat treatment include, for example, about 150 to 250℃for about 1 to 5 minutes.

In the battery packaging material of the present invention, each layer constituting the laminate may be subjected to a surface activation treatment such as corona discharge treatment, sand blast treatment, oxidation treatment, ozone treatment, etc., as needed, in order to improve or stabilize film forming property, lamination processing, suitability for secondary processing of a final product (bagging processing, embossing molding), etc.

4. Use of packaging material for battery

The battery packaging material of the present invention can be used for packaging bodies for sealing and housing battery elements such as positive electrodes, negative electrodes, and electrolytes. That is, a battery element having at least a positive electrode, a negative electrode, and an electrolyte is housed in a package body formed of the battery packaging material of the present invention, and a battery can be produced.

Specifically, with the battery packaging material of the present invention, a battery element having at least a positive electrode, a negative electrode, and an electrolyte is covered with a flange portion (a region where heat-fusible resin layers contact each other) formed around the battery element in a state where metal terminals to which the positive electrode and the negative electrode are connected protrude outside, and the heat-fusible resin layers of the flange portion are sealed by heat welding, whereby a battery using the battery packaging material can be provided. When a battery element is stored in a package formed of the battery packaging material of the present invention, the package is formed such that the heat-fusible resin portion of the battery packaging material of the present invention is inside (surface in contact with the battery element).

The battery packaging material of the present invention can be used for any of primary batteries and secondary batteries, and is preferably used for secondary batteries. The type of secondary battery to which the battery packaging material of the present invention can be applied is not particularly limited, and examples thereof include lithium ion batteries, lithium ion polymer batteries, lead storage batteries, nickel/hydrogen storage batteries, nickel/cadmium storage batteries, nickel/iron storage batteries, nickel/zinc storage batteries, silver oxide/zinc storage batteries, metal air batteries, polyvalent cation batteries, capacitors (capacitors), and the like. Among these secondary batteries, preferred examples of the packaging material for a battery of the present invention include lithium ion batteries and lithium ion polymer batteries.

The battery packaging material of the present invention can exhibit high seal strength by thermal fusion even when the electrolyte is in contact with the thermal fusion resin layer under a high-temperature environment and the thermal fusion resin layers are thermally fused together when the electrolyte is adhered to the thermal fusion resin layer. Therefore, the battery packaging material of the present invention is particularly suitable as a battery packaging material for use in a vehicle battery or a mobile device battery in which the curing process is performed in a high-temperature environment.

Examples

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

< manufacturing of packaging Material for Battery >)

The battery packaging materials of examples 1 to 11 and comparative examples 1 to 4 were produced in the following steps. The laminate structure of each battery packaging material is shown in table 1 below. In table 1, "SC" represents a surface coating layer, "PET" represents a polyethylene terephthalate film, "ONy" represents a stretched nylon film, "DL" represents an adhesive layer or an adhesive layer formed by a dry lamination method, "SUS" represents a stainless steel foil, "ALM" represents an aluminum alloy foil, "Ti" represents a titanium foil, "PPa" represents maleic anhydride-modified polypropylene, "PP" represents random polypropylene, and "CPP" represents an unstretched polypropylene film. In addition, the numerical value after each layer indicates the thickness of the layer, for example, "SUS20" indicates "stainless steel foil having a thickness of 20 μm".

TABLE 1

Example 1

As a base material layer, a polyethylene terephthalate (PET) film (thickness 9 μm) was prepared, and as a barrier layer, a stainless steel foil (SUS 304, thickness 20 μm) was prepared. Next, a two-pack polyurethane adhesive (a polyol compound and an aromatic isocyanate compound) was applied to one surface of the stainless steel foil, and an adhesive layer (thickness 3 μm) was formed on the barrier layer. Next, the adhesive layer on the barrier layer and the base material layer were laminated by a dry lamination method, and then cured, thereby producing a laminate of base material layer/adhesive layer/barrier layer. The stainless steel foil is chemically surface treated on both sides. Chemical surface treatment of stainless Steel foil A treatment solution composed of a phenolic resin, a chromium fluoride Compound and phosphoric acid was applied to both surfaces of a stainless Steel foil by roll coating so that the applied amount of chromium became 10mg/m ² (dry mass) and sintering. Next, a maleic anhydride-modified polypropylene as an adhesive layer (thickness: 14 μm) and a random polypropylene as a heat-fusible resin layer (thickness: 10 μm) were co-extruded onto the barrier layer of each laminate obtained as described above, whereby an adhesive layer/heat-fusible resin layer was laminated onto the barrier layer. Next, a resin composition (polyester polyol, aromatic diisocyanate curing agent Toluene Diisocyanate (TDI) having an isocyanate group as a curing agent, methyl ethyl ketone, and filler (silica particles having an average particle diameter of 1.0 μm)) was applied to the surface of the obtained laminate base layer so as to have a thickness of 3 μm, thereby forming a surface coating layer, and a battery packaging material was obtained in which the surface coating layer/base material layer/adhesive layer/barrier layer/adhesive layer/heat-fusible resin layer were laminated in this order.

Example 2

As a base material layer, a polyethylene terephthalate (PET) film (thickness 9 μm) was prepared, and as a barrier layer, a stainless steel foil (SUS 304, thickness 20 μm) was prepared. Next, a two-pack polyurethane adhesive (a polyol compound and an aromatic isocyanate compound) was applied to one surface of the stainless steel foil, and an adhesive layer (thickness 3 μm) was formed on the barrier layer. Next, the adhesive layer on the barrier layer and the base material layer were laminated by a dry lamination method, and then cured, thereby producing a laminate of base material layer/adhesive layer/barrier layer. The two surfaces of the stainless steel foil were subjected to chemical surface treatment in the same manner as in example 1. Next, a two-pack polyurethane adhesive (a polyol compound and an aromatic isocyanate compound) was applied to the barrier layer of each laminate obtained as described above, and an adhesive layer (thickness 2 μm) was formed on the barrier layer. Then, the adhesive layer on the barrier layer and an unstretched polypropylene film (thickness 23 μm) as a heat-fusible resin layer were laminated by a dry lamination method, and then a curing treatment was performed to laminate an adhesive layer/a heat-fusible resin layer on the barrier layer. Next, a two-component curable resin similar to that of example 1 was applied to the surface of the base layer of the laminate obtained so as to have a thickness of 3 μm, thereby forming a surface coating layer, and a battery packaging material was obtained in which the surface coating layer, the base layer, the adhesive layer, the barrier layer, the adhesive layer, and the heat-fusible resin layer were laminated in this order.

Example 3

As a base material layer, a stretched nylon film (ONy) film (thickness 10 μm) was prepared, and as a barrier layer, a stainless steel foil (SUS 304, thickness 20 μm) was prepared. Next, a two-pack polyurethane adhesive (a polyol compound and an aromatic isocyanate compound) was applied to one surface of the stainless steel foil, and an adhesive layer (thickness 3 μm) was formed on the barrier layer. Next, the adhesive layer on the barrier layer and the base material layer were laminated by a dry lamination method, and then cured, thereby producing a laminate of base material layer/adhesive layer/barrier layer. The two surfaces of the stainless steel foil were subjected to chemical surface treatment in the same manner as in example 1. Next, a two-pack polyurethane adhesive (a polyol compound and an aromatic isocyanate compound) was applied to the barrier layer of each laminate obtained as described above, and an adhesive layer (thickness 2 μm) was formed on the barrier layer. Then, after the adhesive layer on the barrier layer and the unstretched polypropylene film (thickness 23 μm) as the heat-fusible resin layer were laminated by dry lamination, curing treatment was performed to laminate the adhesive layer/the heat-fusible resin layer on the barrier layer. Next, a two-component curable resin similar to that of example 1 was applied to the surface of the base layer of the laminate obtained so as to have a thickness of 3 μm, thereby forming a surface coating layer, and a battery packaging material was obtained in which the surface coating layer, the base layer, the adhesive layer, the barrier layer, the adhesive layer, and the heat-fusible resin layer were laminated in this order.

Example 4

As a base material layer, a polyethylene terephthalate (PET) film (thickness 4 μm) was prepared, and as a barrier layer, a stainless steel foil (SUS 304, thickness 15 μm) was prepared. Next, a two-pack polyurethane adhesive (a polyol compound and an aromatic isocyanate compound) was applied to one surface of the stainless steel foil, and an adhesive layer (thickness 3 μm) was formed on the barrier layer. Next, the adhesive layer on the barrier layer and the base material layer were laminated by a dry lamination method, and then cured, thereby producing a laminate of base material layer/adhesive layer/barrier layer. The two surfaces of the stainless steel foil were subjected to chemical surface treatment in the same manner as in example 1. Next, a two-pack polyurethane adhesive (a polyol compound and an aromatic isocyanate compound) was applied to the barrier layer of each laminate obtained as described above, and an adhesive layer (thickness 2 μm) was formed on the barrier layer. Then, after the adhesive layer on the barrier layer and the unstretched polypropylene film (thickness 23 μm) as the heat-fusible resin layer were laminated by dry lamination, curing treatment was performed to laminate the adhesive layer/the heat-fusible resin layer on the barrier layer. Next, a two-component curable resin similar to that of example 1 was applied to the surface of the base layer of the laminate obtained so as to have a thickness of 3 μm, thereby forming a surface coating layer, and a battery packaging material was obtained in which the surface coating layer, the base layer, the adhesive layer, the barrier layer, the adhesive layer, and the heat-fusible resin layer were laminated in this order.

Example 5

A polyethylene terephthalate (PET) film (thickness: 4 μm) was prepared as a base layer, and an aluminum alloy foil (JIS H41 was prepared as a barrier layer60:1994A8021H-O (thickness 35 μm)). Next, a two-pack polyurethane adhesive (a polyol compound and an aromatic isocyanate compound) was applied to one surface of the aluminum alloy foil, and an adhesive layer (thickness 3 μm) was formed on the barrier layer. Next, the adhesive layer on the barrier layer and the base material layer were laminated by a dry lamination method, and then cured, thereby producing a laminate of base material layer/adhesive layer/barrier layer. Both sides of the aluminum alloy foil were subjected to chemical surface treatment. Chemical surface treatment of aluminum alloy foil A treatment solution composed of a phenolic resin, a chromium fluoride compound and phosphoric acid was applied to both sides of the aluminum alloy foil by roll coating so that the applied amount of chromium became 10mg/m ² (dry mass) and sintering. Next, maleic anhydride-modified polypropylene as an adhesive layer (thickness: 14 μm) and random polypropylene as a heat-fusible resin layer (thickness: 10 μm) were co-extruded onto the barrier layer of each laminate obtained as described above, whereby an adhesive layer/heat-fusible resin layer was laminated onto the barrier layer, and a base layer/adhesive layer/barrier layer/adhesive layer/heat-fusible resin layer was laminated in this order to obtain a packaging material for a battery.

Example 6

As a base material layer, a polyethylene terephthalate (PET) film (thickness: 4 μm) was prepared, and as a barrier layer, an aluminum alloy foil (JIS H4160:1994A8021H-O (thickness: 30 μm)) was prepared. Next, a two-pack polyurethane adhesive (a polyol compound and an aromatic isocyanate compound) was applied to one surface of the aluminum alloy foil, and an adhesive layer (thickness 3 μm) was formed on the barrier layer. Next, the adhesive layer on the barrier layer and the base material layer were laminated by a dry lamination method, and then cured, thereby producing a laminate of base material layer/adhesive layer/barrier layer. Both surfaces of the aluminum alloy foil were subjected to chemical surface treatment in the same manner as in example 5. Next, a two-pack polyurethane adhesive (a polyol compound and an aromatic isocyanate compound) was applied to the barrier layer of each laminate obtained as described above, and an adhesive layer (thickness 2 μm) was formed on the barrier layer. Then, after the adhesive layer on the barrier layer and an unstretched polypropylene film (thickness: 20 μm) as a heat-fusible resin layer were laminated by a dry lamination method, a curing treatment was performed to laminate an adhesive layer/a heat-fusible resin layer on the barrier layer. Next, a two-component curable resin similar to that of example 1 was applied to the surface of the base layer of the laminate obtained so as to have a thickness of 3 μm, thereby forming a surface coating layer, and a battery packaging material was obtained in which the surface coating layer, the base layer, the adhesive layer, the barrier layer, the adhesive layer, and the heat-fusible resin layer were laminated in this order.

Example 7

As a base material layer, a polyethylene terephthalate (PET) film (thickness: 4 μm) was prepared, and as a barrier layer, an aluminum alloy foil (JIS H4160:1994A8021H-O (thickness: 35 μm)) was prepared. Next, a two-pack polyurethane adhesive (a polyol compound and an aromatic isocyanate compound) was applied to one surface of the aluminum alloy foil, and an adhesive layer (thickness 3 μm) was formed on the barrier layer. Next, the adhesive layer on the barrier layer and the base material layer were laminated by a dry lamination method, and then cured, thereby producing a laminate of base material layer/adhesive layer/barrier layer. Both surfaces of the aluminum alloy foil were subjected to chemical surface treatment in the same manner as in example 5. Next, a two-pack polyurethane adhesive (a polyol compound and an aromatic isocyanate compound) was applied to the barrier layer of each laminate obtained as described above, and an adhesive layer (thickness 2 μm) was formed on the barrier layer. Then, after the adhesive layer on the barrier layer and an unstretched polypropylene film (thickness: 20 μm) as a heat-fusible resin layer were laminated by a dry lamination method, a curing treatment was performed to laminate an adhesive layer/a heat-fusible resin layer on the barrier layer. Next, a two-component curable resin similar to that of example 1 was applied to the surface of the base layer of the laminate obtained so as to have a thickness of 3 μm, thereby forming a surface coating layer, and a battery packaging material was obtained in which the surface coating layer, the base layer, the adhesive layer, the barrier layer, the adhesive layer, and the heat-fusible resin layer were laminated in this order.

Example 8

As a base material layer, a stretched nylon film (thickness: 15 μm) was prepared, and as a barrier layer, an aluminum alloy foil (JIS H4160:1994A8021H-O (thickness: 30 μm)) was prepared. Next, a two-pack polyurethane adhesive (a polyol compound and an aromatic isocyanate compound) was applied to one surface of the aluminum alloy foil, and an adhesive layer (thickness 3 μm) was formed on the barrier layer. Next, the adhesive layer on the barrier layer and the base material layer were laminated by a dry lamination method, and then cured, thereby producing a laminate of base material layer/adhesive layer/barrier layer. Both surfaces of the aluminum alloy foil were subjected to chemical surface treatment in the same manner as in example 5. Next, maleic anhydride-modified polypropylene as an adhesive layer (thickness 14 μm) and random polypropylene as a heat-fusible resin layer (thickness 10 μm) were coextruded onto the barrier layer of each laminate obtained as described above, whereby an adhesive layer/heat-fusible resin layer was laminated onto the barrier layer. Next, a two-component curable resin similar to that of example 1 was applied to the surface of the base layer of the laminate obtained so as to have a thickness of 3 μm, thereby forming a surface coating layer, and a battery packaging material was obtained in which the surface coating layer, the base layer, the adhesive layer, the barrier layer, the adhesive layer, and the heat-fusible resin layer were laminated in this order.

Example 9

As a base material layer, a stretched nylon film (ONy) film (thickness 15 μm) was prepared, and as a barrier layer, a stainless steel foil (SUS 304, thickness 40 μm) was prepared.

Next, a two-pack polyurethane adhesive (a polyol compound and an aromatic isocyanate compound) was applied to one surface of the stainless steel foil, and an adhesive layer (thickness 3 μm) was formed on the barrier layer. Next, the adhesive layer on the barrier layer and the base material layer were laminated by a dry lamination method, and then cured, thereby producing a laminate of base material layer/adhesive layer/barrier layer. The two surfaces of the stainless steel foil were subjected to chemical surface treatment in the same manner as in example 1. Next, a two-pack polyurethane adhesive (a polyol compound and an aromatic isocyanate compound) was applied to the barrier layer of each laminate obtained as described above, and an adhesive layer (thickness 2 μm) was formed on the barrier layer. Then, after the adhesive layer on the barrier layer and the unstretched polypropylene film (thickness 23 μm) as the heat-fusible resin layer were laminated by a dry lamination method, curing treatment was performed to laminate the adhesive layer/the heat-fusible resin layer on the barrier layer, and a packaging material for a battery was obtained in which the base layer/the adhesive layer/the barrier layer/the adhesive layer/the heat-fusible resin layer were laminated in this order.

Example 10

A laminate of a base material layer, an adhesive layer, a barrier layer and a random polypropylene layer was laminated on the barrier layer by coating a two-pack type polyurethane adhesive (a polyol compound and an aromatic isocyanate compound) on one surface of an aluminum alloy foil as a barrier layer by preparing a stretched nylon film (thickness 25 μm) and preparing an aluminum alloy foil (JIS H4160:1994A8021H-O (thickness 40 μm), and then laminating the adhesive layer on the barrier layer and the base material layer by a dry lamination method and then subjecting the laminate to a curing treatment.

Example 11

As a base material layer, a stretched nylon film (thickness: 15 μm) was prepared, and as a barrier layer, an aluminum alloy foil (JIS H4160:1994A8021H-O (thickness: 35 μm)) was prepared. Next, a two-pack polyurethane adhesive (a polyol compound and an aromatic isocyanate compound) was applied to one surface of the aluminum alloy foil, and an adhesive layer (thickness 3 μm) was formed on the barrier layer. Next, the adhesive layer on the barrier layer and the base material layer were laminated by a dry lamination method, and then cured, thereby producing a laminate of base material layer/adhesive layer/barrier layer. Both surfaces of the aluminum alloy foil were subjected to chemical surface treatment in the same manner as in example 5. Next, maleic anhydride-modified polypropylene as an adhesive layer (thickness 20 μm) and random polypropylene as a heat-fusible resin layer (thickness 15 μm) were coextruded onto the barrier layer of each laminate obtained as described above, whereby an adhesive layer/heat-fusible resin layer was laminated onto the barrier layer. Next, a two-component curable resin similar to that of example 1 was applied to the surface of the base layer of the laminate obtained so as to have a thickness of 3 μm, thereby forming a surface coating layer, and a battery packaging material was obtained in which the surface coating layer, the base layer, the adhesive layer, the barrier layer, the adhesive layer, and the heat-fusible resin layer were laminated in this order.

Comparative example 1

As a base material layer, a stretched nylon film (thickness: 12 μm) was prepared, and as a barrier layer, an aluminum alloy foil (JIS H4160:1994A8021H-O (thickness: 25 μm)) was prepared. Next, a two-pack polyurethane adhesive (a polyol compound and an aromatic isocyanate compound) was applied to one surface of the aluminum alloy foil, and an adhesive layer (thickness 3 μm) was formed on the barrier layer. Next, the adhesive layer on the barrier layer and the base material layer were laminated by a dry lamination method, and then cured, thereby producing a laminate of base material layer/adhesive layer/barrier layer. Both surfaces of the aluminum alloy foil were subjected to chemical surface treatment in the same manner as in example 5. Next, maleic anhydride-modified polypropylene as an adhesive layer (thickness 14 μm) and random polypropylene as a heat-fusible resin layer (thickness 10 μm) were coextruded onto the barrier layer of each laminate obtained as described above, whereby an adhesive layer/heat-fusible resin layer was laminated onto the barrier layer. Next, a two-component curable resin similar to that of example 1 was applied to the surface of the base layer of the laminate obtained so as to have a thickness of 3 μm, thereby forming a surface coating layer, and a battery packaging material was obtained in which the surface coating layer, the base layer, the adhesive layer, the barrier layer, the adhesive layer, and the heat-fusible resin layer were laminated in this order.

Comparative example 2

As a base material layer, a stretched nylon film (thickness: 15 μm) was prepared, and as a barrier layer, an aluminum alloy foil (JIS H4160:1994A8021H-O (thickness: 20 μm)) was prepared. Next, a two-pack polyurethane adhesive (a polyol compound and an aromatic isocyanate compound) was applied to one surface of the aluminum alloy foil, and an adhesive layer (thickness 3 μm) was formed on the barrier layer. Next, the adhesive layer on the barrier layer and the base material layer were laminated by a dry lamination method, and then cured, thereby producing a laminate of base material layer/adhesive layer/barrier layer. Both surfaces of the aluminum alloy foil were subjected to chemical surface treatment in the same manner as in example 5. Next, maleic anhydride-modified polypropylene as an adhesive layer (thickness: 14 μm) and random polypropylene as a heat-fusible resin layer (thickness: 10 μm) were co-extruded onto the barrier layer of each laminate obtained as described above, whereby an adhesive layer/heat-fusible resin layer was laminated onto the barrier layer, and a base layer/adhesive layer/barrier layer/adhesive layer/heat-fusible resin layer was laminated in this order to obtain a packaging material for a battery.

Comparative example 3

As a base material layer, a stretched nylon film (thickness: 12 μm) was prepared, and as a barrier layer, an aluminum alloy foil (JIS H4160:1994A8021H-O (thickness: 20 μm)) was prepared. Next, a two-pack polyurethane adhesive (a polyol compound and an aromatic isocyanate compound) was applied to one surface of the aluminum alloy foil, and an adhesive layer (thickness 3 μm) was formed on the barrier layer. Next, the adhesive layer on the barrier layer and the base material layer were laminated by a dry lamination method, and then cured, thereby producing a laminate of base material layer/adhesive layer/barrier layer. Both surfaces of the aluminum alloy foil were subjected to chemical surface treatment in the same manner as in example 5. Next, maleic anhydride-modified polypropylene as an adhesive layer (thickness: 14 μm) and random polypropylene as a heat-fusible resin layer (thickness: 10 μm) were co-extruded onto the barrier layer of each laminate obtained as described above, whereby an adhesive layer/heat-fusible resin layer was laminated onto the barrier layer, and a base layer/adhesive layer/barrier layer/adhesive layer/heat-fusible resin layer was laminated in this order to obtain a packaging material for a battery.

Comparative example 4

As a base material layer, a stretched nylon film (ONy) film (thickness 25 μm) was prepared, and as a barrier layer, a laminated foil (thickness 50 μm) composed of an aluminum alloy foil 16 μm and a titanium foil 34 μm was prepared. Next, a two-pack polyurethane adhesive (a polyol compound and an aromatic isocyanate compound) was applied to one surface of the interlayer foil, and an adhesive layer (thickness 3 μm) was formed on the barrier layer. Next, the adhesive layer on the barrier layer and the base material layer were laminated by a dry lamination method, and then cured, thereby producing a laminate of base material layer/adhesive layer/barrier layer. The two sides of the interlayer foil were subjected to chemical surface treatment in the same manner as in example 1. Next, a two-pack polyurethane adhesive (a polyol compound and an aromatic isocyanate compound) was applied to the barrier layer of each laminate obtained as described above, and an adhesive layer (thickness 2 μm) was formed on the barrier layer. Then, after the adhesive layer on the barrier layer and the unstretched polypropylene film (thickness 23 μm) as the heat-fusible resin layer were laminated by a dry lamination method, curing treatment was performed, and the adhesive layer/the heat-fusible resin layer was laminated on the barrier layer, thereby obtaining a packaging material for a battery, in which the base layer/the adhesive layer/the barrier layer/the adhesive layer/the heat-fusible resin layer were laminated in this order.

< measurement of thickness of packaging Material for Battery >

The thickness of each battery packaging material obtained above (thickness in the lamination direction) was measured using a thickness measuring instrument (MITUTOYO 547-401). The measurement results of the thickness of the battery packaging material are shown in table 2.

< determination of flexural rigidity >

Each of the obtained battery packaging materials was cut into a rectangular shape of Cheng Kuandu (direction perpendicular to the flow direction in film formation: TD) and a length (flow direction in film formation: MD) of 80mm to obtain test samples. For the test samples obtained, bending stiffness (gf cm) was measured using a bending stiffness tester (SMT co., ltd./JTC-911 BT) ² /cm). The measurement conditions were such that the curvature change rate was 0.1/cm.sec, the jig interval was 1cm, and the maximum curvature was 2.5cm ^-1 The average value of the flexural rigidity of 10 test samples was used as the flexural rigidity of each battery packaging material obtained as described above. The test specimen was fixed to 2 jigs so that the end edge of the width of 80mm was aligned with the jig axis direction. The measurement results of the flexural rigidity are shown in Table 2.

< determination of puncture Strength >

The obtained packaging material for each battery was cut into a rectangle of Cheng Kuandu mm and 120mm in length to obtain test samples. The test sample obtained was obtained by following JIS Z1707:1997, the puncture strength was measured from the substrate layer side. Specifically, under a measuring environment of 23.+ -. 2 ℃ and relative humidity (50.+ -. 5)%, a test piece was fixed by a 115mm diameter table having an opening of 15mm in the center and a pressing plate, and a semicircular needle having a diameter of 1.0mm and a tip shape radius of 0.5mm was penetrated at a speed of 50.+ -. 5mm per minute, and the maximum stress until penetration of the needle was measured. The number of test pieces was 5, and the average value was obtained. Among them, ZTS-500N (force measuring device) and MX-500N (measuring rack) manufactured by Yimotor company are used as the puncture strength measuring device. The measurement results of the puncture strength are shown in table 2.

< determination of tensile modulus >)

The obtained packaging material for each battery was cut into a rectangle of Cheng Kuandu mm and 100mm in length to obtain test samples. Next, according to JIS K7127:1999, the tensile modulus of the test specimen was calculated under the conditions that the distance between the standard lines was 30mm and the tensile speed was 50 mm/min. The measurement results of the tensile modulus are shown in Table 2.

< determination of Limit Forming depth >

The obtained packaging material for each battery was cut into a rectangle of Cheng Kuandu mm and 150mm in length, and a test sample was obtained. Then, using a female die having a caliber of 30mm×50mm and a male die corresponding thereto, the molding depth was increased by 0.5mm from a molding depth of 0.5mm at a pressing pressure of 0.9MPa under an environment of a temperature of 24 ℃ and a relative humidity of 50%, and molding was performed with a molding depth 0.5mm shallower than the molding depth when pinholes were generated in the battery packaging material as the ultimate molding depth of the sample. In the molding, the male die is disposed on the heat-fusible resin layer side, the concave portion is formed on the heat-fusible resin layer side, and the convex portion is formed on the base material layer side. The clearance between the male die and the female die is set to be 0.3mm. In addition, JIS B0659-1, female mold surface: the maximum height roughness (Rz nominal value) defined in table 2 of the surface roughness standard for comparison in accessory 1 (reference) of 2002 is 3.2 μm. JIS B0659-1 on the male die surface: 2002 annex 1 (reference) the maximum height roughness (Rz nominal value) defined in table 2 of the comparative surface roughness standard is 1.6 μm. The measurement results of the limiting molding depth are shown in table 2.

< evaluation of tape peelability >

The obtained battery packaging materials were molded at a temperature of 24℃and a relative humidity of 50% using a female mold and a male mold under a pressing pressure of 0.9MPa, to form recesses of battery sizes 1 and 2 described below. In the molding, a male die is disposed on the heat-fusible resin layer side, a concave portion is formed on the heat-fusible resin layer side, a convex portion is formed on the base material layer side, and a molding portion is provided. The clearance between the male die and the female die is set to be 0.3mm. In addition, JIS B0659-1, female mold surface: the maximum height roughness (Rz nominal value) defined in table 2 of the surface roughness standard for comparison in accessory 1 (reference) of 2002 is 3.2 μm. JIS B0659-1 on the male die surface: 2002 annex 1 (reference) the maximum height roughness (Rz nominal value) defined in table 2 of the comparative surface roughness standard is 1.6 μm.

Battery size 1: the width of the concave part is 30mm, the length is 90mm, and the molding depth is 3mm

Battery size 2: the width of the concave part is 94mm, the length is 128mm, and the molding depth is 3mm

In example 4, the molding depths of the battery size 1 and the battery size 2 were set to 2mm, respectively, and in comparative example 4, the molding depths of the battery size 1 and the battery size 2 were set to 1.5mm, respectively.

Next, as shown in the schematic view of fig. 5, an acrylic plate 20 having a width of 27mm, a length of 87mm, and a height of 3mm was inserted into the recess of the battery size 1, and an acrylic plate 20 having a width of 91mm, a length of 125mm, and a height (corresponding to the direction of the molding depth) of 3mm was inserted into the recess of the battery size 2. The inserted acrylic plate 20 was fixed to the bottom surface of the concave portion of the battery packaging material using a double-sided tape NO751B manufactured by singe corporation. Next, a double-sided tape 30 (# 610 manufactured by 3M company, thickness 120 μm) having a width of 5mm and a length of 50mm and an aluminum alloy foil 40 (35 μm) were laminated on the surface 10a on the convex side of the molded part of the battery packaging material, and the double-sided tape 30 was stuck to the surface 10a on the convex side of the molded part of the battery packaging material 10 by 1 round trip from the aluminum alloy foil 40 with a 200g rubber roller. Then, the end 30a of the double-sided tape, which is not attached to the protruding portion of the molded portion, is pinched by a finger, and the double-sided tape 30 is pulled in the 180 ° direction (arrow direction in fig. 5) together with the aluminum alloy foil, and peeled from the surface 10a of the protruding portion of the molded portion. Then, the surface of the molded part after the double-sided tape 30 was peeled off was visually observed, and the tape peelability was evaluated according to the following criteria. The evaluation results of the tape peelability are shown in table 2.

A: the molded portion is not carried away by the adhesive tape, and therefore wrinkles are not formed on the surface, and the adhesive tape can be suitably peeled from the surface of the battery packaging material.

C: the molding part is taken away by the adhesive tape, and folds are formed on the surface.

TABLE 2

Symbol description

1: a substrate layer;

2: an adhesive layer;

3: a barrier layer;

4: a heat-fusible resin layer;

5: an adhesive layer;

6: a surface covering layer;

10: packaging material for battery;

10a: a surface of the battery packaging material on the convex side of the molding part;

20: an acrylic plate;

30: double-sided tape;

40: aluminum alloy foil.

Claims

1. A packaging material for a battery, characterized in that,

comprises a laminate having at least a base layer, a barrier layer and a heat-fusible resin layer in this order,

the thickness of the laminate is 50-120 μm,

the barrier layer is formed from a stainless steel foil,

the thickness of the barrier layer is 15 μm or more and 40 μm or less,

2. The packaging material for a battery according to claim 1, wherein,

the stainless steel foil is made of austenitic stainless steel.

3. The packaging material for a battery according to claim 1 or 2, wherein,

An adhesive layer is provided between the substrate layer and the barrier layer,

the adhesive layer contains a colorant.

4. The packaging material for a battery according to claim 1 or 2, wherein,

the surface of the substrate layer opposite to the barrier layer is also provided with a surface covering layer containing an additive.

5. The packaging material for a battery according to claim 1 or 2, wherein,

an adhesive layer is provided between the barrier layer and the heat-fusible resin layer,

the adhesive layer is a cured product of a resin composition containing an acid-modified polyolefin and a curing agent.

6. The packaging material for a battery according to claim 1 or 2, wherein,

the thickness of the base material layer is 25 μm or less.

7. The packaging material for a battery according to claim 1 or 2, wherein,

by following JIS Z1707: the puncture strength measured by the method specified in 1997 when the laminate is punctured from the substrate layer side is 5N to 55N.

8. The packaging material for a battery according to claim 1 or 2, wherein,

by following JIS K7127: the tensile modulus of the laminate in the direction perpendicular to the lamination direction measured by the method specified in 1999 is 3.0GPa to 10.0 GPa.

9. The packaging material for a battery according to claim 1 or 2, wherein,

the heat-fusible resin layer contains a polyolefin.

10. The packaging material for a battery according to claim 1 or 2, wherein,

the base material layer contains at least one of a polyester resin and a polyamide resin.

11. A packaging material for a battery, characterized in that,

the thickness of the laminate is 50-120 μm,

the barrier layer is formed from an aluminium alloy foil,

the thickness of the barrier layer is 15 μm or more and 40 μm or less,

12. The packaging material for a battery according to claim 11, wherein,

the adhesive layer contains a colorant.

13. The packaging material for a battery according to claim 11 or 12, wherein,

14. The packaging material for a battery according to claim 11 or 12, wherein,

15. The packaging material for a battery according to claim 11 or 12, wherein,

the thickness of the base material layer is 25 μm or less.

16. The packaging material for a battery according to claim 11 or 12, wherein,

17. The packaging material for a battery according to claim 11 or 12, wherein,

18. The packaging material for a battery according to claim 11 or 12, wherein,

the heat-fusible resin layer contains a polyolefin.

19. The packaging material for a battery according to claim 11 or 12, wherein,

20. A battery, characterized in that,

A package formed of the battery packaging material according to any one of claims 1 to 19, wherein a battery element including at least a positive electrode, a negative electrode, and an electrolyte is accommodated.