JPWO2019039505A1 - Battery packaging materials and batteries - Google Patents

Abstract

At least a base material layer, a barrier layer, and a battery packaging material composed of a laminate including a heat-fusible resin layer in this order, the thickness of the laminate constituting the battery packaging material, and a barrier. Despite the fact that both layers are thin, it has a certain moldability, and the battery packaging material follows the masking tape when the masking tape attached to the surface of the base material layer is peeled off. (EN) Provided is a battery packaging material which is difficult to form and in which formation of wrinkles is effectively suppressed. At least a base material layer, a barrier layer, and a heat-fusible resin layer are formed of a laminated body in this order, and the thickness of the laminated body is 50 μm or more and 120 μm or less. The battery packaging material has a thickness of 15 μm or more and 40 μm or less and a bending stiffness of the laminate is 0.60 gf·cm 2 /cm or more and 6.0 gf·cm 2 /cm or less.

Description

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

Conventionally, various types of batteries have been developed, but in all batteries, a packaging material has become an indispensable member for sealing battery elements such as electrodes and electrolytes. Conventionally, metal packaging materials have been frequently used as battery packaging.

On the other hand, in recent years, as electric vehicles, hybrid electric vehicles, personal computers, cameras, mobile phones, and the like have become higher in performance, batteries are required to have various shapes and to be thin and lightweight. However, the metal battery packaging materials that have been widely used conventionally have the drawbacks that it is difficult to follow the diversification of the shapes, and there is a limit to the weight reduction.

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

In such a battery packaging material, generally, a recess is formed by cold forming, and a battery element such as an electrode or an electrolytic solution is arranged in the space formed by the recess, and the heat-fusible resin layers are bonded to each other. By heat-sealing, a battery in which the battery element is housed inside the battery packaging material is obtained.

JP, 2008-287971, A

In recent years, with the demand for smaller and thinner batteries, there has been a demand for further thinning of battery packaging materials. However, when the packaging material for a battery is made thin, the barrier layer also becomes thin, and cracks and pinholes are likely to occur at the time of molding, resulting in a problem that moldability is deteriorated.

Further, in the process of manufacturing the battery, from the viewpoint of preventing the electrolyte from adhering to the surface of the battery and causing discoloration, or scratching the surface of the battery, the surface of the battery (that is, by sealing the battery element) The masking tape may be attached to the surface of the packaging material for the existing battery) and peeled off before the battery is used. However, when the thickness of the battery packaging material or the barrier layer becomes thin, when the masking tape is peeled off from the battery surface, the battery packaging material follows the masking tape and wrinkles are formed on the surface of the battery. Therefore, a gap may be formed between the packaging material and the cell including the positive electrode/separator/negative electrode. Then, the electrolytic solution may move from the cell to the void, which may cause deterioration of battery performance, and the voids may cause the packaging material to come into contact with the cell when vibration is applied to the cell, resulting in thermal fusion of the packaging material. The resin layer may be damaged and cause corrosion.

Under such a circumstance, the present invention configures a battery packaging material in a battery packaging material composed of a laminate including at least a base material layer, a barrier layer, and a heat-fusible resin layer in this order. When the masking tape attached to the surface of the base material layer side is peeled off, it has a predetermined moldability even though the thickness of the laminated body and the thickness of the barrier layer are both thin. In addition, the main object of the present invention is to provide a battery packaging material in which the battery packaging material does not easily follow the masking tape and the formation of wrinkles is effectively suppressed.

The present inventors have earnestly studied to solve the above problems. As a result, at least a base material layer, a barrier layer, and a heat-fusible resin layer are formed of a laminated body in this order, and the thickness of the laminated body is 50 μm or more and 120 μm or less. The thickness of the laminate is 15 μm or more and 40 μm or less, and the bending stiffness of the laminated body is 0.60 gf·cm ² /cm or more and 6.0 gf·cm ² /cm or less, and the battery packaging material constitutes the battery packaging material. When the masking tape attached to the surface of the base material layer is peeled off, it has a predetermined moldability even though the thickness of the laminated body and the thickness of the barrier layer are both thin. In addition, it was found that the battery packaging material is difficult to follow the masking tape and the formation of wrinkles is effectively suppressed.
The present invention has been completed by further studies based on these findings.

That is, the present invention provides the inventions of the following modes.
Item 1. At least a base material layer, a barrier layer, and a heat-fusible resin layer, which is composed of a laminate provided in this order,
The thickness of the laminate is 50 μm or more and 120 μm or less,
The barrier layer has a thickness of 15 μm or more and 40 μm or less,
A packaging material for a battery, wherein the laminate has a bending stiffness of 0.60 gf·cm ² /cm or more and 6.0 gf·cm ² /cm or less.
Item 2. Item 2. The battery packaging material according to Item 1, wherein the barrier layer is made of an aluminum alloy foil or a stainless steel foil.
Item 3. Item 3. The battery packaging material according to Item 1 or 2, further comprising a surface coating layer containing an additive on the surface of the base material layer opposite to the barrier layer.
Item 4. Item 4. The battery packaging material according to any one of Items 1 to 3, wherein the base material layer has a thickness of 25 µm or less.
Item 5. In any one of Items 1 to 4, the puncture strength when piercing from the base material layer side of the laminate is 5N or more and 55N or less, which is measured by a method in conformity with JIS Z1707:1997. The packaging material for a battery as described.
Item 6. In any one of items 1 to 5, the tensile modulus in the direction perpendicular to the laminating direction of the laminate, which is measured by a method in conformity with JIS K7127:1999, is 3.0 GPa or more and 10.0 GPa or less. The packaging material for a battery as described.
Item 7. Item 7. The battery packaging material according to any one of Items 1 to 6, wherein the heat-fusible resin layer contains a polyolefin.
Item 8. Item 8. 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.
Item 9. A battery in which a battery element including at least a positive electrode, a negative electrode, and an electrolyte is housed in a package formed of the battery packaging material according to any one of Items 1 to 8.

The present invention relates to a battery packaging material comprising at least a base material layer, a barrier layer, and a heat-fusible resin layer in this order, and a laminate comprising the battery packaging material. Despite the fact that both the thickness and the thickness of the barrier layer are thin, they have a predetermined formability, and when the masking tape attached to the surface of the base material layer is peeled off, a battery packaging material. It is difficult to follow the masking tape, and it is possible to provide a battery packaging material in which the formation of wrinkles is effectively suppressed. Moreover, according to this invention, the manufacturing method of the said packaging material for batteries, and the battery using the said packaging material for batteries can also be provided.

It is a figure which shows an example of the cross-section of the packaging material for batteries of this invention. It is a figure which shows an example of the cross-section of the packaging material for batteries of this invention. It is a figure which shows an example of the cross-section of the packaging material for batteries of this invention. It is a figure which shows an example of the cross-section of the packaging material for batteries of this invention. It is a schematic diagram for demonstrating the tape peelability evaluation method in an Example.

The battery packaging material of the present invention is composed of a laminate including at least a base material layer, a barrier layer, and a heat-fusible resin layer in this order, and the thickness of the laminate is 50 μm or more and 120 μm or less. The barrier layer has a thickness of 15 μm or more and 40 μm or less, and the bending stiffness of the laminate is 0.60 gf·cm ² /cm or more and 6.0 gf·cm ² /cm or less. In the battery packaging material of the present invention, by having such a configuration, the thickness of the laminate constituting the battery packaging material and the thickness of the barrier layer are both thin, but the predetermined thickness is obtained. It is also effective to form wrinkles because the battery packaging material does not easily follow the masking tape when the masking tape attached to the surface of the base material layer is peeled off. Suppressed to. Hereinafter, the battery packaging material of the present invention will be described in detail.

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

1. Laminated Structure and Physical Properties of Battery Packaging Material A battery packaging material 10 of the present invention includes at least a base material layer 1, a barrier layer 3, and a heat-fusible resin layer 4 in this order as shown in FIG. It is composed of a laminate. In the battery packaging material of the present invention, the base material layer 1 is the outermost layer side and the heat-fusible resin layer 4 is the innermost layer. That is, when the battery is assembled, the heat-fusible resin layers 4 located on the periphery of the battery element are heat-sealed to seal the battery element, thereby sealing the battery element.

The battery packaging material 10 of the present invention may include an adhesive layer 2 between a base material layer 1 and a barrier layer 3, as shown in FIGS. 2 to 4, for example. Further, for example, as shown in FIGS. 3 and 4, an adhesive layer 5 may be provided between the barrier layer 3 and the heat-fusible resin layer 4. Further, as shown in FIG. 4, a surface coating layer 6 may be provided on the outer side of the base material layer 1 (on the side opposite to the heat-fusible resin layer 4), if necessary.

The thickness of the laminate constituting the battery packaging material 10 of the present invention is in the range of 50 to 120 μm. Since the battery packaging material 10 of the present invention is thus very thin, the energy density of the battery can be increased. Furthermore, as will be described later, the battery packaging material 10 of the present invention has a predetermined moldability because the bending stiffness of the laminate is set within a specific range, although the thickness is very thin. When the masking tape is applied to the surface of the base material layer side when the masking tape is peeled off, the battery packaging material is difficult to follow the masking tape and wrinkles are formed. Is effectively suppressed.

The thickness of the laminate constituting the battery packaging material 10 of the present invention is not particularly limited as long as it is within the above range, while exhibiting a predetermined moldability while reducing the thickness of the battery packaging material. From the viewpoint of suppressing wrinkles due to peeling of 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, about 70 μm or less. The preferable range of the thickness of the laminate is about 50 to 115 μm, about 50 to 90 μm, about 50 to 80 μm, about 50 to 75 μm, about 50 to 70 μm, about 55 to 120 μm, about 55 to 115 μm, about 55 to 90 μm. About 55 to 80 μm, about 55 to 75 μm, about 55 to 70 μm, about 60 to 120 μm, about 60 to 115 μm, about 60 to 90 μm, about 60 to 80 μm, about 60 to 75 μm, and about 60 to 70 μm. The thickness of the laminate that constitutes the battery packaging material 10 can be measured using a commercially available thickness measuring instrument.

The bending stiffness of the laminate constituting the battery packaging material 10 of the present invention is in the range of 0.60 to 6.0 gf·cm ² /cm. As described above, the battery packaging material 10 of the present invention has a predetermined flexural rigidity of the laminated body in spite of the extremely thin thickness, so that the predetermined molding can be achieved. When the masking tape is applied to the surface of the base material layer side, the battery packaging material does not easily follow the masking tape when the masking tape is peeled off, and wrinkles are formed. Are effectively suppressed.

The bending stiffness of the laminate constituting the battery packaging material 10 of the present invention may be within the above range, but the battery packaging material exhibits a predetermined formability while reducing the thickness of the battery packaging material, and further masking. From the viewpoint of suppressing wrinkles due to peeling of the tape, the lower limit of the bending stiffness is preferably about 0.65 gf·cm ² /cm or more, more preferably about 0.70 gf·cm ² /cm or more, and further preferably about 0.80 gf·cm ² /cm or more, and the upper limit is preferably about 5.00 gf·cm ² /cm or less, about 1.60 gf·cm ² /cm or less, about 1.55 gf·cm ² /cm. These include: Preferred ranges of the bending stiffness, 0.60~5.00gf · cm ² / cm approximately, 0.60~1.60gf · cm ² / cm approximately, 0.60~1.55gf · cm ² / cm about , 0.65 to 6.00 gf·cm ² /cm, 0.65 to 5.00 gf·cm ² /cm, 0.65 to 1.60 gf·cm ² /cm, 0.65 to 1.55 gf cm ² /cm, 0.70 to 6.00 gf·cm ² /cm, 0.70 to 5.00 gf·cm ² /cm, 0.70 to 1.60 gf·cm ² /cm, 0. 70 to 1.55 gf·cm ² /cm, 0.80 to 6.00 gf·cm ² /cm, 0.80 to 5.00 gf·cm ² /cm, 0.80 to 1.60 gf·cm ^2. /Cm, about 0.80 to 1.55 gf·cm ² /cm.

The bending stiffness of the laminate forming the battery packaging material 10 can be adjusted by, for example, the thickness and composition of the layers forming the laminate.

In the present invention, the method for measuring the bending stiffness of the laminate constituting the battery packaging material 10 is as follows. Specifically, it can be measured by the method described in Examples.

<Measurement of bending stiffness>
The battery packaging material is cut into a rectangle having a width (direction perpendicular to the flow direction during film formation: TD) of 80 mm and a length (flow direction during film formation: MD) of 100 mm to obtain a test sample. The bending stiffness (gf·cm ² /cm) of the obtained test sample is measured using a commercially available bending stiffness measuring machine. The measurement conditions were as follows: the rate of curvature change was 0.1/cm·sec, the clamp interval was 1 cm, the maximum curvature was 2.5 cm ⁻¹ , and the average bending stiffness of 10 test samples was calculated as the bending stiffness of the battery packaging material. And In addition, the test sample is fixed to two clamps so that the edge having a width of 80 mm coincides with the clamp axis direction.

From the viewpoint of exhibiting a predetermined formability while reducing the thickness of the battery packaging material and further suppressing wrinkles due to peeling of the masking tape, the laminate constituting the battery packaging material 10 of the present invention is JIS Z1707. : The puncture strength when pierced from the base material layer side, which is measured by a method in conformity with the regulations of 1997, is preferably in the range of 5 to 55 N, and in the range of 5 to 40 N. More preferably, it is still more preferably within the range of 14 to 40N.

In the present invention, the method for measuring the puncture strength of the laminate constituting the battery packaging material 10 is as follows. Specifically, it can be measured by the method described in Examples.

<Measurement of piercing strength>
The puncture strength of the laminate constituting the battery packaging material from the side of the base material layer is measured by a method in conformity with JIS Z1707:1997. Specifically, in a measurement environment of 23±2° C. and relative humidity (50±5)%, a test piece is fixed with a table having a diameter of 115 mm having an opening of 15 mm in the center and a pressing plate, and a diameter of 1.0 mm, A semicircular needle having a tip shape radius of 0.5 mm is pierced at a speed of 50±5 mm/min, and the maximum stress until the needle penetrates is measured. The number of test pieces is 5, and the average value is calculated. When the number of test pieces is insufficient and 5 pieces cannot be measured, the measurable number is measured and the average value is obtained.

From the viewpoint of reducing the thickness of the battery packaging material while exhibiting a predetermined moldability and further suppressing wrinkles due to peeling of the masking tape, the laminate constituting the battery packaging material 10 of the present invention is The tensile modulus in the direction perpendicular to the laminating direction of the laminate, which is measured by a method in conformity with JIS K7127:1999, is preferably in the range of 3.0 to 10.0 GPa, and 3.8 to 10. More preferably, it is in the range of 9.5 GPa.

In the present invention, the method for measuring the tensile elastic modulus of the laminate constituting the battery packaging material 10 is as follows. Specifically, it can be measured by the method described in Examples.

<Measurement of tensile modulus>
The battery packaging material is cut into a rectangle having a width of 15 mm and a length of 100 mm to obtain a test sample. Next, according to JIS K7127:1999, the tensile modulus of elasticity of the test sample is calculated in the length direction of the test sample by pulling the test sample under the conditions of a distance between marked lines of 30 mm and a pulling speed of 50 mm/min. The length of the test sample does not have to be 100 mm as long as the test can be performed under the above measurement conditions.

As the masking tape, for example, an adhesive tape 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 can be mentioned. A commercial item of such an adhesive tape is easily available.

2. Each layer forming the battery packaging material [base material 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 forming the base material layer 1 is not particularly limited as long as it has an insulating property. As a material for forming the base material layer 1, for example, a resin film such as a polyester resin, a polyamide resin, an epoxy resin, an acrylic resin, a fluororesin, a polyurethane resin, a silicone resin, a phenol resin, a polycarbonate, or a mixture or copolymer thereof. Are listed. Among these, polyester resin and polyamide resin are preferable, and biaxially stretched polyester resin and biaxially stretched polyamide resin are more preferable. Specific examples of the polyester resin include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, and copolyester. Specific examples of the polyamide resin include nylon 6, nylon 66, a copolymer of nylon 6 and nylon 66, nylon 6,10, polymethaxylylene adipamide (MXD6), and the like.

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 a single resin film, but may be formed of two or more resin films in order to improve pinhole resistance and insulation. Specific examples thereof include a multilayer structure in which a polyester film and a nylon film are laminated, a multilayer structure in which a plurality of nylon films are laminated, and a multilayer structure in which a plurality of polyester films are laminated. When the base material layer 1 has a multilayer structure, a laminate of a biaxially oriented nylon film and a biaxially oriented polyester film, a laminate of a plurality of biaxially oriented nylon films, and a laminate of a plurality of biaxially oriented polyester films. The body is preferred. For example, when the base material layer 1 is formed of two layers of resin film, a constitution in which a polyester resin and a polyester resin are laminated, a constitution in which a polyamide resin and a polyamide resin are laminated, or a constitution in which a polyester resin and a polyamide resin are laminated Is preferable, and a structure in which polyethylene terephthalate and polyethylene terephthalate are laminated, a structure in which nylon and nylon are laminated, or a structure in which polyethylene terephthalate and nylon are laminated are more preferable. In addition, since the polyester resin is unlikely to discolor when the electrolytic solution adheres to the surface, for example, it is preferable that the base material layer 1 is laminated so that the polyester resin is located at the outermost layer in the laminated structure. 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 multilayer resin film, two or more resin films may be laminated via an adhesive component such as an adhesive or an adhesive resin, and the type and amount of the adhesive component used, etc. Is the same as that of the adhesive layer 2 described later. The method for laminating two or more resin films is not particularly limited, and a known method can be adopted, and examples thereof include a dry laminating method and a sandwich laminating method, and a dry laminating method is preferable. When laminating by a dry laminating method, it is preferable to use a urethane adhesive as the adhesive layer. At this time, the thickness of the adhesive layer is, for example, about 2 to 5 μm. When the base material layer 1 is composed of a multilayer resin film, the adhesive portion does not substantially contribute to the moldability and the like, and thus is not included in the thickness of the base material layer 1.

In the present invention, a lubricant is preferably attached to the surface of the base material layer 1 from the viewpoint of enhancing the moldability of the battery packaging material. The lubricant is not particularly limited, but preferably an amide lubricant is used. Specific examples of the amide-based lubricant include the same as those exemplified for the heat-fusible resin layer 4 described later.

When a lubricant is present on the surface of the base material layer 1, its amount is not particularly limited, but is preferably about 3 mg/m ² or more, more preferably 4 to 4 in an environment of a temperature of 24° C. and a relative humidity of 60%. 15 mg / m ² about, even more preferably include about 5~14mg / m ^2.

The base material layer 1 may contain a lubricant. Further, the lubricant present on the surface of the base material layer 1 may be one in which the lubricant contained in the resin constituting the base material layer 1 is exuded, or one in which the lubricant is applied to the surface of the base material layer 1. May be

The thickness of the base material layer 1 is not particularly limited as long as it functions as a base material, but it exhibits a predetermined formability while reducing the thickness of the battery packaging material. From the viewpoint of suppressing wrinkles, 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 μm, about 3 to 10 μm, about 4 to 15 μm, and about 4 to 10 μm.

The base material layer 1 has a thickness of about 3 to 10 μm from the viewpoint of exhibiting a predetermined moldability while reducing the thickness of the battery packaging material and suppressing wrinkles due to peeling of the masking tape. It is particularly preferable that

[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 in order to firmly bond them.

The adhesive layer 2 is formed of an adhesive that can bond the base material layer 1 and the barrier layer 3 together. The adhesive used for forming the adhesive layer 2 may be a two-component curable adhesive or a one-component curable adhesive. Further, the adhesion mechanism of the adhesive used to form the adhesive layer 2 is not particularly limited, and may be any of a chemical reaction type, a solvent volatilization type, a heat melting type, a hot pressing type and the like.

Specific examples of the adhesive component that can be used to form the adhesive layer 2 include polyester resins such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, polycarbonate, and copolyester; Polyether adhesives; Polyurethane adhesives; Epoxy resins; Phenolic resin resins; Nylon 6, Nylon 66, Nylon 12, polyamide resins such as copolyamides; Polyolefins, carboxylic acid modified polyolefins, metal modified polyolefins, etc. Polyolefin resin, polyvinyl acetate resin; cellulosic adhesive; (meth)acrylic resin; polyimide resin; urea resin, amino resin such as melamine resin; chloroprene rubber, nitrile rubber, rubber such as styrene-butadiene rubber; Examples include silicone resins. These adhesive components may be used alone or in combination of two or more. Among these adhesive components, a polyurethane adhesive is preferable.

Further, the adhesive layer 2 may include a coloring agent. Since the adhesive layer 2 contains the coloring agent, the battery packaging material can be colored. Known colorants such as pigments and dyes can be used as the colorant. Moreover, only one type of colorant may be used, or two or more types may be mixed and used.

For example, specific examples of the inorganic pigment preferably include carbon black and titanium oxide. Further, specific examples of the organic pigment preferably include an azo pigment, a phthalocyanine pigment, and a condensed polycyclic pigment. Examples of azo pigments include soluble pigments such as Watching Red and Carmine 6C; insoluble azo pigments such as Monoazo Yellow, Disazo Yellow, Pyrazolone Orange, Pyrazolone Red, and Permanent Red. Phthalocyanine pigments include copper phthalocyanine pigment and no pigment. Examples of the metal phthalocyanine pigment include blue pigments and green pigments, and examples of the condensed polycyclic pigments include dioxazine violet and quinacridone violet. Further, as the pigment, a pearl pigment, a fluorescent pigment, or the like can be used.

Among the colorants, for example, carbon black is preferable in order to make the appearance of the battery packaging material black.

The average particle diameter of the pigment is not particularly limited and may be, for example, about 0.05 to 5 μm, preferably about 0.08 to 2 μm. The average particle size of the pigment is the median size measured by a laser diffraction/scattering particle size distribution measuring device.

The content of the pigment in the adhesive layer 2 is not particularly limited as long as the battery packaging material is colored, and examples thereof include about 5 to 60 mass %.

A colored 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. Known colorants such as pigments and dyes can be used as the colorant. Moreover, only one type of colorant may be used, or two or more types may be mixed and used. Specific examples of the colorant contained in the colored layer are the same as those 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 an ink containing a colorant, a diamine, a polyol, and a curing agent. A known solvent can be used as the solvent contained in the ink, and examples thereof include toluene.

The thickness of the adhesive layer 2 is not particularly limited as long as it exhibits an adhesive function, but is, for example, about 1 to 10 μm, preferably about 2 to 5 μm.

[Barrier layer 3]
In the battery packaging material, the barrier layer 3 has a function of improving the strength of the battery packaging material and having a function of preventing water vapor, oxygen, light, and the like from entering the inside of the battery. The barrier layer 3 is preferably a metal layer, that is, a layer formed of a metal. Specific examples of the metal forming the barrier layer 3 include aluminum alloy foil, stainless steel foil, titanium and the like, and preferably aluminum alloy foil or stainless steel foil. From the viewpoint of preventing generation of wrinkles and pinholes in the barrier layer 3 during the production of the battery packaging material, the barrier layer may be, for example, an annealed aluminum alloy foil (JIS H4160:1994 A8021H-O, JIS. H4160:1994 A8079H-O, JIS H4000:2014 A8021P-O, JIS H4000:2014 A8079P-O) and the like, and it is more preferable to form a soft aluminum alloy foil.

Examples of the stainless steel foil include austenitic stainless steel foil and ferritic stainless steel foil. In the present invention, the stainless steel foil 3 is an austenitic stainless steel from the viewpoint of providing a packaging material for a battery, which has high rigidity, is less likely to form wrinkles when the tape is peeled, and has excellent moldability. It is preferably made of steel. Specific examples of the austenitic stainless steel forming the stainless steel foil 3 include SUS304, SUS301, and SUS316L. Among them, for batteries having high puncture strength, excellent electrolytic solution resistance and moldability SUS304 is particularly preferable from the viewpoint of a packaging material.

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 battery packaging material is thin, but also the barrier layer is thin, the bending stiffness of the laminate is set within a specific range. By doing so, when the masking tape is attached to the surface of the base material layer, the packaging material for the battery can follow the masking tape when the masking tape is adhered to the surface of the base material layer. It is difficult to prevent wrinkles from being formed effectively. The lower limit of the thickness of the barrier layer 3 is preferably about 20 μm or more from the viewpoint of exhibiting a predetermined moldability while reducing the thickness of the battery packaging material and suppressing wrinkles due to peeling of the masking tape. The upper limit is preferably about 40 μm or less, more preferably 35 μm or less, and the preferable 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, 20. About 30 μm. More specifically, when the barrier layer 3 is made of, for example, stainless steel foil, the lower limit of the thickness of the barrier layer 3 is preferably about 15 μm or more, and the upper limit is preferably. The thickness is about 40 μm or less, and a preferable range of the thickness is about 15 to 40 μm, about 15 to 35 μm, and about 15 to 25 μm. When 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 25 μm or more, and the upper limit is about 40 μm. The following is mentioned, and as a preferable range of the thickness, about 20 to 40 μm, about 20 to 35 μm, about 20 to 30 μm, about 25 to 35 μm, and about 25 to 30 μm can be mentioned.

Further, it is preferable that at least one side, preferably both sides, of the barrier layer 3 is subjected to chemical conversion treatment in order to stabilize adhesion, prevent dissolution and corrosion. Here, the chemical conversion treatment means a treatment for forming an acid resistant film on the surface of the barrier layer. As the chemical conversion treatment, for example, chromate treatment using a chromium compound such as chromium nitrate, chromium fluoride, chromium sulfate, chromium acetate, chromium oxalate, chromium diphosphate, acetyl acetate acetate, chromium chloride, potassium chromium sulfate; phosphorus; Phosphoric acid treatment using a phosphoric acid compound such as sodium phosphate, potassium phosphate, ammonium phosphate, and polyphosphoric acid; using an aminated phenol polymer having repeating units represented by the following general formulas (1) to (4) The chromate treatment, etc., can be mentioned. In the aminated phenol polymer, the repeating units represented by the following general formulas (1) to (4) may be contained alone or in any combination of two or more. Good.

In formulas (1) to (4), X represents a hydrogen atom, a hydroxy group, an alkyl group, a hydroxyalkyl group, an allyl group or a benzyl group. R ¹ and R ² are the same or different and each represents a hydroxy group, an alkyl group, or a hydroxyalkyl group. In the general formulas (1) to (4), examples of the alkyl group represented by X, R ¹ and R ² include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, Examples thereof include linear or branched alkyl groups having 1 to 4 carbon atoms such as tert-butyl group. Examples of the hydroxyalkyl group represented by X, R ¹ and R ² include a hydroxymethyl group, a 1-hydroxyethyl group, a 2-hydroxyethyl group, a 1-hydroxypropyl group, a 2-hydroxypropyl group, and a 3-hydroxypropyl group. A straight or branched chain having 1 to 4 carbon atoms in which one hydroxy group such as a hydroxypropyl group, a 1-hydroxybutyl group, a 2-hydroxybutyl group, a 3-hydroxybutyl group, and a 4-hydroxybutyl group is substituted. An alkyl group is mentioned. In the general formulas (1) to (4), the alkyl group and the hydroxyalkyl group represented by X, R ¹ and R ² may be the same or different. In the general formulas (1) to (4), X is preferably a hydrogen atom, a hydroxy group or a hydroxyalkyl group. The number average molecular weight of the aminated phenol polymer having the repeating units represented by the general formulas (1) to (4) is, for example, preferably about 500 to 1,000,000, and more preferably about 1,000 to 20,000. More preferable.

As a chemical conversion treatment method for imparting corrosion resistance to the barrier layer 3, phosphoric acid is coated with a dispersion of metal oxides such as aluminum oxide, titanium oxide, cerium oxide and tin oxide, or fine particles of barium sulfate, An example is a method of forming an acid resistant film on the surface of the barrier layer 3 by performing a baking treatment at 150° C. or higher. Further, a resin layer obtained by crosslinking a cationic polymer with a crosslinking agent may be further formed on the acid resistant film. Here, as the cationic polymer, for example, polyethyleneimine, an ionic polymer complex composed of a polymer having polyethyleneimine and a carboxylic acid, a primary amine-grafted acrylic resin obtained by graft-polymerizing a primary amine on an acrylic main skeleton, polyallylamine Alternatively, derivatives thereof, aminophenol and the like can be mentioned. As these cationic polymers, only one kind may be used, or two or more kinds may be used in combination. Examples of the cross-linking agent include compounds having at least one functional group selected from the group consisting of an isocyanate group, a glycidyl group, a carboxyl group, and an oxazoline group, a silane coupling agent, and the like. As these cross-linking agents, only one kind may be used, or two or more kinds may be used in combination.

As a specific method for providing the acid-resistant coating, for example, as one example, at least the inner layer side of the aluminum alloy foil is firstly subjected to an alkali dipping method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method. Degreasing treatment is performed by a well-known treatment method such as an acid activation method, and then the degreasing treated surface is treated with a metal phosphate such as chromium phosphate, titanium phosphate, zirconium phosphate, zinc phosphate and the like. Treatment liquid containing a mixture of metal salts as a main component (aqueous solution), treatment liquid containing a non-metallic phosphate and a mixture of these non-metal salts as a main component (aqueous solution), or an acrylic resin Or a phenolic resin or a urethane resin, a treatment liquid (aqueous solution) consisting of a mixture with an aqueous synthetic resin is applied by a well-known coating method such as a roll coating method, a gravure printing method or a dipping method to form an acid resistant film. Can be formed. For example, when treated with a chromium phosphate salt-based treatment liquid, it becomes an acid resistant film composed of chromium phosphate, aluminum phosphate, aluminum oxide, aluminum hydroxide, aluminum fluoride, etc., and treated with a zinc phosphate salt-based treatment liquid. In this case, an acid resistant film made of zinc phosphate hydrate, aluminum phosphate, aluminum oxide, aluminum hydroxide, aluminum fluoride or the like is obtained.

Further, as another example of the specific method of providing the acid resistant coating, for example, at least the surface on the inner layer side of the aluminum alloy foil is first subjected to an alkali dipping method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method, an acid. By performing a degreasing treatment by a well-known treatment method such as an activation method, and then performing a well-known anodic oxidation treatment on the degreased surface, an acid resistant film can be formed.

Further, as another example of the acid resistant coating, a phosphate coating or a chromic acid coating may be mentioned. Examples of the phosphate type include zinc phosphate, iron phosphate, manganese phosphate, calcium phosphate, and chromium phosphate, and examples of the chromic acid type include chromium chromate.

Further, as another example of the acid resistant film, by forming an acid resistant film of phosphate, chromate, fluoride, triazine thiol compound, etc., between the aluminum and the base material layer at the time of embossing molding. Delamination prevention, hydrogen fluoride generated by the reaction of electrolyte and water prevents dissolution and corrosion of aluminum surface, especially aluminum oxide present on the surface of aluminum, and prevents adhesion and adhesion of aluminum surface. The properties (wettability) are improved, and delamination between the base material layer and aluminum during heat fusion is prevented, and in the embossed type, delamination between the base material layer and aluminum during press molding is exhibited. Among the substances that form an acid resistant film, an aqueous solution composed of three components of a phenol resin, a chromium (III) fluoride compound, and phosphoric acid is applied to the aluminum surface, and dry baking is preferable.

The acid-resistant coating includes a layer having cerium oxide, phosphoric acid or a phosphate, an anionic polymer, and a cross-linking agent that cross-links the anionic polymer, and the phosphoric acid or the phosphate is About 1 to 100 parts by mass may be mixed with 100 parts by mass of cerium oxide. It is preferable that the acid resistant coating has a multilayer structure further including a layer having a cationic polymer and a crosslinking agent that crosslinks the cationic polymer.

Further, it is preferable that the anionic polymer is poly(meth)acrylic acid or a salt thereof, or a copolymer containing (meth)acrylic acid or a salt as a main component. Further, it is preferable that the cross-linking agent is at least one selected from the group consisting of a compound having a functional group of any one of an isocyanate group, a glycidyl group, a carboxyl group and an oxazoline group, and a silane coupling agent.

Further, it is preferable that the phosphoric acid or the phosphate is a condensed phosphoric acid or a condensed phosphate.

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

Specific examples of the acid resistant coating include those containing at least one of phosphate, chromate, fluoride, and triazine thiol. An acid resistant coating containing a cerium compound is also preferable. The cerium compound is preferably cerium oxide.

Further, specific examples of the acid resistant coating include a phosphate coating, a chromate coating, a fluoride coating, a triazine thiol compound coating, and the like. As the acid resistant film, one kind of these may be used, or a combination of a plurality of kinds may be used. Further, as the acid resistant film, after degreasing the chemical conversion treatment surface of the aluminum alloy foil, a treatment liquid consisting of a mixture of a metal phosphate and an aqueous synthetic resin, or a mixture of a nonmetallic phosphate and an aqueous synthetic resin. It may be formed of a treatment liquid consisting of

The composition of the acid resistant film can be analyzed by, for example, time-of-flight secondary ion mass spectrometry. By analysis of the composition of the acid resistant coating using time-of-flight secondary ion mass spectrometry, for example, a peak derived from at least one of Ce+ and Cr+ is detected.

It is preferable that the surface of the aluminum alloy foil or the stainless steel foil is provided with an acid resistant film containing at least one element selected from the group consisting of phosphorus, chromium and cerium. It should be noted that the fact that at least one element selected from the group consisting of phosphorus, chromium and cerium is contained in the acid resistant film on the surface of the aluminum alloy foil or the stainless steel foil of the battery packaging material means that X-ray photoelectron spectroscopy Can be confirmed using. Specifically, first, in the battery packaging material, the heat-fusible resin layer, the adhesive layer, and the like laminated on the aluminum alloy foil or the stainless steel foil are physically peeled off. Next, the aluminum alloy foil or the stainless steel foil is put into an electric furnace, and the organic component existing on the surface of the aluminum alloy foil or the stainless steel foil is removed at about 300° C. for about 30 minutes. Then, X-ray photoelectron spectroscopy of the surface of the aluminum alloy foil or the stainless steel foil is used to confirm that these elements are contained.

The amount of the acid resistant film formed on the surface of the barrier layer 3 in the chemical conversion treatment is not particularly limited, but for example, when the above chromate treatment is performed, the chromium compound is chromium compound per 1 m ² of the surface of the barrier layer 3. Converted to about 0.5 to 50 mg, preferably about 1.0 to 40 mg, phosphorus compound converted to about 0.5 to 50 mg, preferably about 1.0 to 40 mg, and aminated phenol polymer 1.0. ˜200 mg, preferably 5.0 to 150 mg.

The thickness of the acid resistant coating is not particularly limited, but from the viewpoint of the cohesive strength of the coating and the adhesion with the barrier layer 3 and the heat-sealing resin layer, it is preferably about 1 nm to 10 μm, more preferably 1 to 100 nm. And more preferably about 1 to 50 nm. The thickness of the acid resistant film can be measured by observation with a transmission electron microscope or a combination of observation with a transmission electron microscope and energy dispersive X-ray spectroscopy or electron beam energy loss spectroscopy.

The chemical conversion treatment is carried out by applying a solution containing a compound used for forming an acid resistant film to the surface of the barrier layer by a bar coating method, a roll coating method, a gravure coating method, a dipping method or the like, and then the temperature of the barrier layer is 70 It is performed by heating so as to be about 200°C. In addition, before subjecting the barrier layer to the chemical conversion treatment, the barrier layer may be previously subjected to a degreasing treatment by an alkali dipping method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method, or the like. By performing the degreasing treatment in this way, it becomes possible to more efficiently perform the chemical conversion treatment on the surface of the barrier layer.

[The 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-sealing the heat-fusible resin layers during assembly of the battery.

The resin component used in the heat-fusible resin layer 4 is not particularly limited as long as it can be heat-bonded, and examples thereof include polyolefin, cyclic polyolefin, acid-modified polyolefin, and acid-modified cyclic polyolefin. That is, the resin forming the heat-fusible resin layer 4 may or may not contain a polyolefin skeleton, and preferably contains a polyolefin skeleton. The fact that the resin constituting the heat-fusible resin layer 4 contains a polyolefin skeleton can be analyzed by, for example, infrared spectroscopy, gas chromatography mass spectrometry, etc., and the analysis method is not particularly limited. For example, when measuring the infrared spectroscopy at a maleic anhydride-modified polyolefin, a peak derived from maleic acid is detected in the vicinity of the wave number of 1760 cm ^-1 and near the wave number 1780 cm ^-1. However, if the degree of acid modification is low, the peak may be too small to be detected. In that case, it can be analyzed by nuclear magnetic resonance spectroscopy.

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

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

The acid-modified polyolefin is a polymer modified by subjecting the polyolefin to 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, or anhydrides thereof.

The acid-modified cyclic polyolefin is obtained by copolymerizing a part of the monomers constituting the cyclic polyolefin in place of an α,β-unsaturated carboxylic acid or an anhydride thereof, or with respect to the cyclic polyolefin, α,β-. It is a polymer obtained by block-polymerizing or graft-polymerizing an unsaturated carboxylic acid or an anhydride thereof. The cyclic polyolefin modified with carboxylic acid is the same as described above. The carboxylic acid used for modification is the same as the acid component used for modifying the polyolefin.

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

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

In the present invention, from the viewpoint of enhancing the moldability of the battery packaging material, it is preferable that a lubricant is attached to the surface of the heat-fusible resin layer. The lubricant is not particularly limited, but preferably an amide lubricant is used. Specific examples of the amide-based lubricant include saturated fatty acid amide, unsaturated fatty acid amide, substituted amide, methylolamide, saturated fatty acid bisamide, unsaturated fatty acid bisamide, and the like. 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 unsaturated fatty acid amides include oleic acid amide and erucic acid amide. Specific examples of the substituted amide include N-oleyl palmitate amide, N-stearyl stearic acid amide, N-stearyl oleic acid amide, N-oleyl stearic acid amide, and N-stearyl erucic acid amide. Specific examples of methylolamide include methylolstearic acid amide. Specific examples of the saturated fatty acid bisamide include methylenebisstearic acid amide, ethylenebiscapric acid amide, ethylenebislauric acid amide, ethylenebisstearic acid amide, ethylenebishydroxystearic acid amide, ethylenebisbehenic acid amide, and hexamethylenebisstearic acid amide. Examples thereof include acid amide, hexamethylene bisbehenic acid amide, hexamethylene hydroxystearic acid amide, N,N′-distearyl adipic acid amide, and N,N′-distearyl sebacic acid amide. Specific examples of the unsaturated fatty acid bisamide include ethylenebisoleic acid amide, ethylenebiserucic acid amide, hexamethylenebisoleic acid amide, N,N′-dioleyl adipic acid amide, and N,N′-dioleyl sebacic acid amide. And so on. Specific examples of the fatty acid ester amide include stearoamide ethyl stearate. Further, specific examples of the aromatic bisamide include m-xylylenebisstearic acid amide, m-xylylenebishydroxystearic acid amide, N,N'-distearylisophthalic acid amide and the like. The lubricant may be used alone or in combination of two or more.

When a lubricant is present on the surface of the heat-fusible resin layer 4, its amount is not particularly limited, but is preferably about 3 mg/m ² or more, more preferably in an environment of a temperature of 24° C. and a relative humidity of 60%. Is about 4 to 15 mg/m ² , more preferably about 5 to 14 mg/m ² .

The heat-fusible resin layer 4 may contain a lubricant. Further, the lubricant present on the surface of the heat-fusible resin layer 4 may be one in which the lubricant contained in the resin constituting the heat-fusible resin layer 4 is exuded, or the heat-fusible resin layer. The surface of 4 may be coated with a lubricant.

The thickness of the heat-fusible resin layer 4 is not particularly limited as long as the function as the heat-fusible resin layer is exerted, but the thickness of the battery packaging material can be reduced and a predetermined moldability can be obtained. From the viewpoint of exerting the effect and suppressing wrinkles due to peeling of the masking tape, 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. Are listed. The preferable range of the thickness of the heat-fusible resin layer is about 8 to 30 μm, about 8 to 25 μm, about 10 to 30 μm, and about 10 to 25 μm.

[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 in order to firmly bond them together.

The adhesive layer 5 is formed of a resin that can bond the barrier layer 3 and the heat-fusible resin layer 4. As the resin used for forming the adhesive layer 5, the same adhesive mechanism, kind of adhesive component, and the like as the adhesive exemplified in the adhesive layer 2 can be used. Further, as the resin used for forming the adhesive layer 5, polyolefin resins such as the polyolefin, cyclic polyolefin, carboxylic acid-modified polyolefin, and carboxylic acid-modified cyclic polyolefin exemplified in the above heat-fusible resin layer 4 can also 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 forming the adhesive layer 5 may or may not contain a polyolefin skeleton, and preferably contains a polyolefin skeleton. The fact that the resin constituting the adhesive layer 5 contains a polyolefin skeleton can be analyzed by, for example, infrared spectroscopy, gas chromatography mass spectrometry, etc., and the analysis method is not particularly limited. For example, when measuring the infrared spectroscopy at a maleic anhydride-modified polyolefin, a peak derived from maleic acid is detected in the vicinity of the wave number of 1760 cm ^-1 and near the wave number 1780 cm ^-1. However, if the degree of acid modification is low, the peak may be too small to be detected. In that case, it can be analyzed by nuclear magnetic resonance spectroscopy.

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

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

The epoxy curing agent is not particularly limited as long as it is a compound having at least one 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, glycerin polyglycidyl ether, and polyglycerin polyglycidyl ether.

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

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

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

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

The content of the curing agent in the resin composition forming the adhesive layer 5 is preferably in the range of about 0.1 to 50% by mass, more preferably in the range of about 0.1 to 30% by mass, More preferably, it is 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 it functions as an adhesive layer, but when the adhesive exemplified in the adhesive layer 2 is used, it is preferably about 1 to 10 μm, more preferably 1 About 5 μm. When the resin exemplified in the heat-fusible resin layer 4 is used, the thickness is preferably about 2 to 25 μm, more preferably about 10 to 20 μm. Further, in the case of a cured product of an acid-modified polyolefin and a curing agent, it is preferably about 10 μm or less, more preferably about 0.1 to 10 μm, still more preferably about 0.5 to 5 μm. When the adhesive layer 5 is a cured product of a resin composition containing an acid-modified polyolefin and a curing agent, the adhesive layer 5 can be formed by applying the resin composition and curing it by heating or the like.

[Surface coating layer 6]
In the battery packaging material of the present invention, if necessary, on the base material layer 1 (barrier layer of the base material layer 1) for the purpose of improving designability, electrolytic solution resistance, scratch resistance, moldability, and the like. A surface coating layer 6 may be provided on the side opposite to 3) as necessary. The surface coating layer 6 is the outermost layer when the battery is assembled.

The surface coating layer 6 can be formed of, for example, polyvinylidene chloride, polyester resin, urethane resin, acrylic resin, epoxy resin, or the like. Of these, the surface coating layer 6 is preferably formed of a two-component curable resin. Examples of the two-component curing type resin forming the surface coating layer 6 include a two-component curing type urethane resin, a two-component curing type polyester resin, a two-component curing type epoxy resin and the like. Moreover, you may mix|blend an additive with the surface coating layer 6.

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

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

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

The thickness of the surface coating layer 6 is not particularly limited as long as the above-mentioned functions of the surface coating layer 6 are exhibited, but is, for example, about 0.5 to 10 μm, preferably about 1 to 5 μm.

3. Method for Producing Battery Packaging Material The method for producing the battery packaging material of the present invention is not particularly limited as long as a laminated body obtained by laminating each layer having a predetermined composition is obtained.

An example of the method for producing the battery packaging material of the present invention is as follows. First, a laminated body in which the base material layer 1, the adhesive layer 2, and the barrier layer 3 are laminated in order (hereinafter, also referred to as “laminated body A”) is formed. Specifically, the laminate A is formed by applying the adhesive agent used for forming the adhesive layer 2 to the base material layer 1 or the barrier layer 3 whose surface has been subjected to chemical conversion treatment, if necessary, using a gravure coating method or a roll method. This can be performed by a dry laminating method in which the barrier layer 3 or the base material layer 1 is laminated and the adhesive layer 2 is cured after being applied and dried by a coating method such as a coating method.

Next, the adhesive layer 5 and the heat-fusible resin layer 4 are laminated on the barrier layer 3 of the laminate A in this order. For example, (1) a method of laminating the adhesive layer 5 and the heat-fusible resin layer 4 on the barrier layer 3 of the laminate A by co-extruding (co-extrusion laminating method), (2) a separate adhesive layer 5 And a heat-fusible resin layer 4 are laminated to form a laminated body, and the laminated body is laminated on the barrier layer 3 of the laminated body A by a thermal lamination method. (3) Adhesion on the barrier layer 3 of the laminated body A An adhesive for forming the layer 5 is laminated by an extrusion method, a solution coating method, a drying method at a high temperature, a baking method, or the like, and the heat-fusible resin layer 4 previously formed into a sheet on the adhesive layer 5. Method of laminating by thermal lamination method, (4) Adhesion while pouring a melted adhesive layer 5 between the barrier layer 3 of the laminated body A and the heat-fusible resin layer 4 formed into a sheet in advance. A method of laminating the laminate A and the heat-fusible resin layer 4 via the layer 5 (sandwich laminating method) and the like can be mentioned.

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, applying the above-mentioned resin forming the surface coating layer 6 to 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 forming the surface coating layer 6 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 surface coating layer 6/if necessary, the base material layer 1/the adhesive layer 2/if necessary, the barrier layer 3 whose surface has been subjected to chemical conversion treatment/the adhesive layer 5 / A laminated body composed of the heat-fusible resin layer 4 is formed. In order to strengthen the adhesiveness of the adhesive layer 2 or the adhesive layer 5, a hot roll contact type, a hot air type, a near infrared type or It may be subjected to a heat treatment such as a far infrared ray method. The conditions for such heat treatment include, for example, 150 to 250° C. and 1 to 5 minutes.

In the battery packaging material of the present invention, each layer constituting the laminate improves or stabilizes film forming properties, lamination processing, suitability for secondary processing of the final product (pouching, embossing molding), etc., if necessary. Therefore, surface activation treatment such as corona treatment, blast treatment, oxidation treatment, and ozone treatment may be performed.

4. Application of Battery Packaging Material The battery packaging material of the present invention is used for a package for hermetically containing battery elements such as a positive electrode, a negative electrode and an electrolyte. That is, the battery formed by the battery packaging material of the present invention can accommodate a battery element including at least a positive electrode, a negative electrode, and an electrolyte to form a battery.

Specifically, a battery element having at least a positive electrode, a negative electrode, and an electrolyte, in the battery packaging material of the present invention, in a state where the metal terminals connected to each of the positive electrode and the negative electrode are projected outward, By covering the periphery of the element so that a flange portion (a region where the heat-fusible resin layers contact each other) can be formed, and heat-sealing the heat-fusible resin layers of the flange portion to seal them, A battery using the battery packaging material is provided. When the battery element is housed in a package formed of the battery packaging material of the present invention, the heat-fusible resin portion of the battery packaging material of the present invention is placed inside (the surface that contacts the battery element). Then, a package is formed.

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

The battery packaging material of the present invention, the electrolytic solution is in contact with the heat-fusible resin layer in a high temperature environment, the heat-fusible resin layers are heat-sealed in a state in which the electrolyte solution is attached to the heat-fusible resin layer. Even if it is applied, high sealing strength is exhibited by heat fusion. Therefore, the battery packaging material of the present invention can be particularly suitably used as a battery packaging material used for a vehicle battery or a mobile device battery in which an aging step is performed in a high temperature environment.

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

<Manufacture of battery packaging materials>
The packaging materials for batteries of Examples 1 to 11 and Comparative Examples 1 to 4 were manufactured by the following procedure. The laminated constitution of each battery packaging material is as shown in Table 1 below. In Table 1, “SC” is a surface coating layer, “PET” is a polyethylene terephthalate film, “ONy” is a stretched nylon film, “DL” is an adhesive layer or an adhesive layer formed by a dry lamination method, and “SUS” is Stainless steel foil, “ALM” means aluminum alloy foil, “Ti” means titanium foil, “PPa” means maleic anhydride modified polypropylene, “PP” means random polypropylene, and “CPP” means unstretched polypropylene film. Further, the numerical value behind each layer means the thickness (μm) of the layer, and for example, “SUS20” means “stainless steel foil having a thickness of 20 μm”.

Example 1
A polyethylene terephthalate (PET) film (thickness 9 μm) was prepared as the base material layer, and a stainless steel foil (SUS304, thickness 20 μm) was prepared as the barrier layer. Next, a two-component urethane adhesive (polyol compound and aromatic isocyanate compound) was applied to one surface of the stainless steel foil to form an adhesive layer (thickness 3 μm) on the barrier layer. Next, the adhesive layer on the barrier layer and the base material layer were laminated by a dry laminating method, and then an aging treatment was carried out to produce a laminate of base material layer/adhesive layer/barrier layer. Both sides of the stainless steel foil have been subjected to chemical conversion treatment. The chemical conversion treatment of the stainless steel foil is carried out by roll-coating the stainless steel foil so that the amount of chromium applied is 10 mg/m ² (dry mass) of the treatment liquid consisting of phenol resin, chromium fluoride compound, and phosphoric acid. It was performed by coating on both sides and baking. Next, on the barrier layer of each laminate obtained above, 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 provided. Was coextruded to laminate the adhesive layer/heat-fusible resin layer on the barrier layer. Next, on the surface of the base material layer of the obtained laminate, a resin composition (polyester polyol, toluene diisocyanate (TDI) which is an aromatic diisocyanate curing agent as a curing agent having an isocyanate group, methyl ethyl ketone and filler (average particle A surface coating layer is formed by coating silica particles having a diameter of 1.0 μm) to a thickness of 3 μm, and the surface coating layer/base material layer/adhesive layer/barrier layer/adhesive layer/heat fusion is formed. A packaging material for a battery in which the adhesive resin layer was laminated in order was obtained.

Example 2
A polyethylene terephthalate (PET) film (thickness 9 μm) was prepared as the base material layer, and a stainless steel foil (SUS304, thickness 20 μm) was prepared as the barrier layer. Next, a two-component urethane adhesive (polyol compound and aromatic isocyanate compound) was applied to one surface of the stainless steel foil to form an adhesive layer (thickness 3 μm) on the barrier layer. Next, the adhesive layer on the barrier layer and the base material layer were laminated by a dry laminating method, and then an aging treatment was carried out to produce a laminate of base material layer/adhesive layer/barrier layer. Both sides of the stainless steel foil were subjected to chemical conversion treatment in the same manner as in Example 1. Next, a two-component urethane adhesive (polyol compound and aromatic isocyanate compound) was applied onto the barrier layer of each laminate obtained above, and an adhesive layer (thickness 2 μm) was applied onto the barrier layer. Formed. Then, an adhesive layer on the barrier layer and an unstretched polypropylene film (thickness 23 μm) as a heat-fusible resin layer are laminated by a dry laminating method, and then an aging treatment is performed to form an adhesive layer on the barrier layer. /The heat-fusible resin layer was laminated. Next, a surface coating layer was formed by coating the surface of the base material layer of the obtained laminate with the same two-component curable resin as in Example 1 to a thickness of 3 μm. A packaging material for a battery was obtained in which /substrate layer/adhesive layer/barrier layer/adhesive layer/heat-fusible resin layer were laminated in order.

Example 3
A stretched nylon film (ONy) film (thickness 10 μm) was prepared as the base material layer, and a stainless steel foil (SUS304, thickness 20 μm) was prepared as the barrier layer. Next, a two-component urethane adhesive (polyol compound and aromatic isocyanate compound) was applied to one surface of the stainless steel foil to form an adhesive layer (thickness 3 μm) on the barrier layer. Next, the adhesive layer on the barrier layer and the base material layer were laminated by a dry laminating method, and then an aging treatment was carried out to produce a laminate of base material layer/adhesive layer/barrier layer. Both sides of the stainless steel foil were subjected to chemical conversion treatment in the same manner as in Example 1. Next, a two-component urethane adhesive (polyol compound and aromatic isocyanate compound) was applied onto the barrier layer of each laminate obtained above, and an adhesive layer (thickness 2 μm) was applied onto the barrier layer. Formed. Then, an adhesive layer on the barrier layer and an unstretched polypropylene film (thickness 23 μm) as a heat-fusible resin layer are laminated by a dry laminating method, and then an aging treatment is performed to form an adhesive layer on the barrier layer. /The heat-fusible resin layer was laminated. Next, a surface coating layer was formed by coating the surface of the base material layer of the obtained laminate with the same two-component curable resin as in Example 1 to a thickness of 3 μm. A packaging material for a battery was obtained in which /substrate layer/adhesive layer/barrier layer/adhesive layer/heat-fusible resin layer were laminated in this order.

Example 4
A polyethylene terephthalate (PET) film (thickness 4 μm) was prepared as the base material layer, and a stainless steel foil (SUS304, thickness 15 μm) was prepared as the barrier layer. Next, a two-component urethane adhesive (polyol compound and aromatic isocyanate compound) was applied to one surface of the stainless steel foil to form an adhesive layer (thickness 3 μm) on the barrier layer. Next, the adhesive layer on the barrier layer and the base material layer were laminated by a dry laminating method, and then an aging treatment was carried out to produce a laminate of base material layer/adhesive layer/barrier layer. Both sides of the stainless steel foil were subjected to chemical conversion treatment in the same manner as in Example 1. Next, a two-component urethane adhesive (polyol compound and aromatic isocyanate compound) was applied onto the barrier layer of each laminate obtained above, and an adhesive layer (thickness 2 μm) was applied onto the barrier layer. Formed. Then, an adhesive layer on the barrier layer and an unstretched polypropylene film (thickness 23 μm) as a heat-fusible resin layer are laminated by a dry laminating method, and then an aging treatment is performed to form an adhesive layer on the barrier layer. /The heat-fusible resin layer was laminated. Next, a surface coating layer was formed by coating the surface of the base material layer of the obtained laminate with the same two-component curable resin as in Example 1 to a thickness of 3 μm. A packaging material for a battery was obtained in which /substrate layer/adhesive layer/barrier layer/adhesive layer/heat-fusible resin layer were laminated in this order.

Example 5
A polyethylene terephthalate (PET) film (thickness 4 μm) was prepared as the base material layer, and an aluminum alloy foil (JIS H4160:1994 A8021H—O (thickness 35 μm)) was prepared as the barrier layer. Next, a two-component urethane adhesive (polyol compound and aromatic isocyanate-based compound) was applied to one surface of the aluminum alloy foil to form an adhesive layer (thickness 3 μm) on the barrier layer. Next, the adhesive layer on the barrier layer and the base material layer were laminated by a dry laminating method, and then an aging treatment was carried out to produce a laminate of base material layer/adhesive layer/barrier layer. Both sides of the aluminum alloy foil are subjected to chemical conversion treatment. The chemical conversion treatment of the aluminum alloy foil is performed by roll-coating the treatment liquid consisting of a phenol resin, a chromium fluoride compound, and phosphoric acid so that the coating amount of chromium is 10 mg/m ² (dry mass). It was performed by coating on both sides and baking. Next, on the barrier layer of each laminate obtained above, 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 provided. By co-extruding, the adhesive layer/heat-fusible resin layer is laminated on the barrier layer, and the base material layer/adhesive layer/barrier layer/adhesive layer/heat-fusible resin layer are sequentially laminated. The battery packaging material thus obtained was obtained.

Example 6
A polyethylene terephthalate (PET) film (thickness 4 μm) was prepared as the base material layer, and an aluminum alloy foil (JIS H4160:1994 A8021H—O (thickness 30 μm)) was prepared as the barrier layer. Next, a two-component urethane adhesive (polyol compound and aromatic isocyanate-based compound) was applied to one surface of the aluminum alloy foil to form an adhesive layer (thickness 3 μm) on the barrier layer. Next, the adhesive layer on the barrier layer and the base material layer were laminated by a dry laminating method, and then an aging treatment was carried out to produce a laminate of base material layer/adhesive layer/barrier layer. Both sides of the aluminum alloy foil were subjected to chemical conversion treatment in the same manner as in Example 5. Next, a two-component urethane adhesive (polyol compound and aromatic isocyanate compound) was applied onto the barrier layer of each laminate obtained above, and an adhesive layer (thickness 2 μm) was applied onto the barrier layer. Formed. Then, an adhesive layer on the barrier layer and an unstretched polypropylene film (thickness 20 μm) as a heat-fusible resin layer are laminated by a dry laminating method, and then aging treatment is performed to form an adhesive layer on the barrier layer. /The heat-fusible resin layer was laminated. Next, a surface coating layer was formed by coating the surface of the base material layer of the obtained laminate with the same two-component curable resin as in Example 1 to a thickness of 3 μm. A packaging material for a battery was obtained in which /substrate layer/adhesive layer/barrier layer/adhesive layer/heat-fusible resin layer were laminated in this order.

Example 7
A polyethylene terephthalate (PET) film (thickness 4 μm) was prepared as the base material layer, and an aluminum alloy foil (JIS H4160:1994 A8021H—O (thickness 35 μm)) was prepared as the barrier layer. Next, a two-component urethane adhesive (polyol compound and aromatic isocyanate-based compound) was applied to one surface of the aluminum alloy foil to form an adhesive layer (thickness 3 μm) on the barrier layer. Next, the adhesive layer on the barrier layer and the base material layer were laminated by a dry laminating method, and then an aging treatment was carried out to produce a laminate of base material layer/adhesive layer/barrier layer. Both sides of the aluminum alloy foil were subjected to chemical conversion treatment in the same manner as in Example 5. Next, a two-component urethane adhesive (polyol compound and aromatic isocyanate compound) was applied onto the barrier layer of each laminate obtained above, and an adhesive layer (thickness 2 μm) was applied onto the barrier layer. Formed. Then, an adhesive layer on the barrier layer and an unstretched polypropylene film (thickness 20 μm) as a heat-fusible resin layer are laminated by a dry laminating method, and then aging treatment is performed to form an adhesive layer on the barrier layer. /The heat-fusible resin layer was laminated. Next, a surface coating layer was formed by coating the surface of the base material layer of the obtained laminate with the same two-component curable resin as in Example 1 to a thickness of 3 μm. A packaging material for a battery was obtained in which /substrate layer/adhesive layer/barrier layer/adhesive layer/heat-fusible resin layer were laminated in this order.

Example 8
A stretched nylon film (thickness 15 μm) was prepared as the base material layer, and an aluminum alloy foil (JIS H4160:1994 A8021H-O (thickness 30 μm)) was prepared as the barrier layer. Next, a two-component urethane adhesive (polyol compound and aromatic isocyanate-based compound) was applied to one surface of the aluminum alloy foil to form an adhesive layer (thickness 3 μm) on the barrier layer. Next, the adhesive layer on the barrier layer and the base material layer were laminated by a dry laminating method, and then an aging treatment was carried out to produce a laminate of base material layer/adhesive layer/barrier layer. Both sides of the aluminum alloy foil were subjected to chemical conversion treatment in the same manner as in Example 5. Next, on the barrier layer of each laminate obtained above, 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 provided. Was coextruded to laminate the adhesive layer/heat-fusible resin layer on the barrier layer. Next, a surface coating layer was formed by coating the surface of the base material layer of the obtained laminate with the same two-component curable resin as in Example 1 to a thickness of 3 μm. A battery packaging material was obtained in which the following structure was laminated: /base material layer/adhesive layer/barrier layer/adhesive layer/heat-fusible resin layer.

Example 9
A stretched nylon film (ONy) film (thickness 15 μm) was prepared as the base material layer, and a stainless steel foil (SUS304, thickness 40 μm) was prepared as the barrier layer. Next, a two-component urethane adhesive (polyol compound and aromatic isocyanate compound) was applied to one surface of the stainless steel foil to form an adhesive layer (thickness 3 μm) on the barrier layer. Next, the adhesive layer on the barrier layer and the base material layer were laminated by a dry laminating method, and then an aging treatment was carried out to produce a laminate of base material layer/adhesive layer/barrier layer. Both sides of the stainless steel foil were subjected to chemical conversion treatment in the same manner as in Example 1. Next, a two-component urethane adhesive (polyol compound and aromatic isocyanate compound) was applied onto the barrier layer of each laminate obtained above, and an adhesive layer (thickness 2 μm) was applied onto the barrier layer. Formed. Then, an adhesive layer on the barrier layer and an unstretched polypropylene film (thickness 23 μm) as a heat-fusible resin layer are laminated by a dry laminating method, and then an aging treatment is performed to form an adhesive layer on the barrier layer. /Heat-fusible resin layer was laminated to obtain a battery packaging material in which a base material layer/adhesive layer/barrier layer/adhesive layer/heat-fusible resin layer were laminated in order.

Example 10
A stretched nylon film (thickness 25 μm) was prepared as the base material layer, and an aluminum alloy foil (JIS H4160:1994 A8021H-O (thickness 40 μm)) was prepared as the barrier layer. Next, a two-component urethane adhesive (polyol compound and aromatic isocyanate-based compound) was applied to one surface of the aluminum alloy foil to form an adhesive layer (thickness 3 μm) on the barrier layer. Next, the adhesive layer on the barrier layer and the base material layer were laminated by a dry laminating method, and then an aging treatment was carried out to produce a laminate of base material layer/adhesive layer/barrier layer. Both sides of the aluminum alloy foil were subjected to chemical conversion treatment in the same manner as in Example 5. Next, maleic anhydride-modified polypropylene as an adhesive layer (thickness 23 μm) and random polypropylene as a heat-fusible resin layer (thickness 22 μm) were formed on the barrier layer of each laminate obtained above. By co-extruding, the adhesive layer/heat-fusible resin layer is laminated on the barrier layer, and the base material layer/adhesive layer/barrier layer/adhesive layer/heat-fusible resin layer are sequentially laminated. A battery packaging material was obtained.

Example 11
A stretched nylon film (thickness 15 μm) was prepared as the base material layer, and an aluminum alloy foil (JIS H4160:1994 A8021H-O (thickness 35 μm)) was prepared as the barrier layer. Next, a two-component urethane adhesive (polyol compound and aromatic isocyanate-based compound) was applied to one surface of the aluminum alloy foil to form an adhesive layer (thickness 3 μm) on the barrier layer. Next, the adhesive layer on the barrier layer and the base material layer were laminated by a dry laminating method, and then an aging treatment was carried out to produce a laminate of base material layer/adhesive layer/barrier layer. Both sides of the aluminum alloy foil were subjected to chemical conversion 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 provided on the barrier layer of each laminate obtained above. Was coextruded to laminate the adhesive layer/heat-fusible resin layer on the barrier layer. Next, a surface coating layer was formed by coating the surface of the base material layer of the obtained laminate with the same two-component curable resin as in Example 1 to a thickness of 3 μm. A packaging material for a battery was obtained in which /substrate layer/adhesive layer/barrier layer/adhesive layer/heat-fusible resin layer were laminated in this order.

Comparative Example 1
A stretched nylon film (thickness 12 μm) was prepared as the base material layer, and an aluminum alloy foil (JIS H4160:1994 A8021H-O (thickness 25 μm)) was prepared as the barrier layer. Next, a two-component urethane adhesive (polyol compound and aromatic isocyanate-based compound) was applied to one surface of the aluminum alloy foil to form an adhesive layer (thickness 3 μm) on the barrier layer. Next, the adhesive layer on the barrier layer and the base material layer were laminated by a dry laminating method, and then an aging treatment was carried out to produce a laminate of base material layer/adhesive layer/barrier layer. Both sides of the aluminum alloy foil were subjected to chemical conversion treatment in the same manner as in Example 5. Next, on the barrier layer of each laminate obtained above, 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 provided. Was coextruded to laminate the adhesive layer/heat-fusible resin layer on the barrier layer. Next, a surface coating layer was formed by coating the surface of the base material layer of the obtained laminate with the same two-component curable resin as in Example 1 to a thickness of 3 μm. A packaging material for a battery was obtained in which /substrate layer/adhesive layer/barrier layer/adhesive layer/heat-fusible resin layer were laminated in this order.

Comparative example 2
A stretched nylon film (thickness 15 μm) was prepared as the base material layer, and an aluminum alloy foil (JIS H4160:1994 A8021H—O (thickness 20 μm)) was prepared as the barrier layer. Next, a two-component urethane adhesive (polyol compound and aromatic isocyanate-based compound) was applied to one surface of the aluminum alloy foil to form an adhesive layer (thickness 3 μm) on the barrier layer. Next, the adhesive layer on the barrier layer and the base material layer were laminated by a dry laminating method, and then an aging treatment was carried out to produce a laminate of base material layer/adhesive layer/barrier layer. Both sides of the aluminum alloy foil were subjected to chemical conversion treatment in the same manner as in Example 5. Next, on the barrier layer of each laminate obtained above, 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 provided. By co-extruding, the adhesive layer/heat-fusible resin layer is laminated on the barrier layer, and the base material layer/adhesive layer/barrier layer/adhesive layer/heat-fusible resin layer are sequentially laminated. The battery packaging material thus obtained was obtained.

Comparative Example 3
A stretched nylon film (thickness 12 μm) was prepared as the base material layer, and an aluminum alloy foil (JIS H4160:1994 A8021H—O (thickness 20 μm)) was prepared as the barrier layer. Next, a two-component urethane adhesive (polyol compound and aromatic isocyanate-based compound) was applied to one surface of the aluminum alloy foil to form an adhesive layer (thickness 3 μm) on the barrier layer. Next, the adhesive layer on the barrier layer and the base material layer were laminated by a dry laminating method, and then an aging treatment was carried out to produce a laminate of base material layer/adhesive layer/barrier layer. Both sides of the aluminum alloy foil were subjected to chemical conversion treatment in the same manner as in Example 5. Next, on the barrier layer of each laminate obtained above, 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 provided. By co-extruding, the adhesive layer/heat-fusible resin layer is laminated on the barrier layer, and the base material layer/adhesive layer/barrier layer/adhesive layer/heat-fusible resin layer are sequentially laminated. The battery packaging material thus obtained was obtained.

Comparative Example 4
A stretched nylon film (ONy) film (thickness: 25 μm) was prepared as a base material layer, and a clad foil (thickness: 50 μm) composed of an aluminum alloy foil 16 μm and a titanium foil 34 μm was prepared as a barrier layer. Next, a two-component urethane adhesive (polyol compound and aromatic isocyanate-based compound) was applied to one surface of the clad foil to form an adhesive layer (thickness 3 μm) on the barrier layer. Next, the adhesive layer on the barrier layer and the base material layer were laminated by a dry laminating method, and then an aging treatment was carried out to produce a laminate of base material layer/adhesive layer/barrier layer. Both sides of the clad foil are subjected to chemical conversion treatment in the same manner as in Example 1. Next, a two-component urethane adhesive (polyol compound and aromatic isocyanate compound) was applied onto the barrier layer of each laminate obtained above, and an adhesive layer (thickness 2 μm) was applied onto the barrier layer. Formed. Then, an adhesive layer on the barrier layer and an unstretched polypropylene film (thickness 23 μm) as a heat-fusible resin layer are laminated by a dry laminating method, and then an aging treatment is performed to form an adhesive layer on the barrier layer. /Heat-fusible resin layer was laminated to obtain a battery packaging material in which a base material layer/adhesive layer/barrier layer/adhesive layer/heat-fusible resin layer were laminated in order.

<Measurement of thickness of battery packaging material>
The thickness (thickness in the stacking direction) of each of the battery packaging materials obtained above was measured using a thickness measuring device (MITUTOYO 547-401). Table 2 shows the measurement results of the thickness of the battery packaging material.

<Measurement of bending stiffness>
Each of the battery packaging materials obtained above was cut into a rectangle having a width (direction perpendicular to the flow direction during film formation: TD) of 80 mm and a length (flow direction during film formation: MD) of 100 mm to obtain a test sample. Got The bending stiffness (gf·cm ² /cm) of the obtained test sample was measured using a bending stiffness measuring machine (SMT/JTC-911BT). The measurement conditions were a curvature change rate of 0.1/cm·sec, a clamp interval of 1 cm, and a maximum curvature of 2.5 cm ^−1, and the average value of bending stiffness of 10 test samples was calculated for each battery obtained above. Bending stiffness of packaging material for. The test sample was fixed to two clamps so that the edge having a width of 80 mm was aligned with the clamp axis direction. The measurement results of bending stiffness are shown in Table 2.

<Measurement of piercing strength>
Each of the battery packaging materials obtained above was cut into a rectangle having a width of 80 mm and a length of 120 mm to obtain a test sample. The puncture strength of the obtained test sample was measured from the base material layer side by a method according to JIS Z1707:1997. Specifically, in a measurement environment of 23±2° C. and relative humidity (50±5)%, a test piece is fixed with a table having a diameter of 115 mm having an opening of 15 mm in the center and a pressing plate, and a diameter of 1.0 mm, A semicircular needle having a tip shape radius of 0.5 mm was pierced at a speed of 50±5 mm/min, and the maximum stress until the needle penetrated was measured. The number of test pieces was 5, and the average value was calculated. As a device for measuring the puncture strength, ZTS-500N (force gauge) and MX-500N (measuring stand) manufactured by Imada Co. were used. Table 2 shows the measurement results of the puncture strength.

<Measurement of tensile modulus>
Each of the battery packaging materials obtained above was cut into a rectangle having a width of 15 mm and a length of 100 mm to obtain a test sample. Next, according to JIS K7127:1999, the tensile modulus of elasticity of the test sample was calculated by pulling the test sample in the length direction of the test sample under the conditions of a distance between marked lines of 30 mm and a pulling speed of 50 mm/min. Table 2 shows the measurement results of the tensile elastic modulus.

<Measurement of critical forming depth>
Each of the battery packaging materials obtained above was cut into a rectangle having a width of 90 mm and a length of 150 mm to obtain a test sample. Next, in a temperature of 24° C. and a relative humidity of 50%, using a female die having a diameter of 30 mm×50 mm and a corresponding male die, a pressing pressure of 0.9 MPa and a forming depth of 0.5 mm were used. Molding was performed by increasing the molding depth in increments of 0.5 mm, and the molding depth 0.5 mm shallower than the molding depth when pinholes were generated in the battery packaging material was defined as the limit molding depth of the sample. The molding was performed by disposing the male mold on the side of the heat-fusible resin layer so that the concave portion was formed on the side of the heat-fusible resin layer and the convex portion was formed on the side of the base material layer. The male-female clearance was 0.3 mm. The surface of the female mold has a maximum height roughness (nominal value of Rz) of 3.2 μm, which is defined in Table 2 of JIS B 0659-1:2002 Annex 1 (Reference) Comparative Surface Roughness Standard Piece. Is. The male surface has a maximum height roughness (nominal value of Rz) of 1.6 μm, which is specified in Table 2 of JIS B 0659-1:2002 Annex 1 (Reference) Comparative Surface Roughness Standard Piece. .. Table 2 shows the measurement results of the limit forming depth.

<Evaluation of tape peelability>
Using a female mold and a male mold in an environment of a temperature of 24° C. and a relative humidity of 50%, the packaging material for each battery obtained above was molded with a holding pressure of 0.9 MPa, and the following battery sizes 1 and 2 were prepared. The recess was formed. The molding was performed by disposing the male mold on the heat-fusible resin layer side, and the molding portion was provided so that the concave portion was formed on the heat-fusible resin layer side and the convex portion was formed on the base material layer side. The male-female clearance was 0.3 mm. The surface of the female mold has a maximum height roughness (nominal value of Rz) of 3.2 μm, which is defined in Table 2 of JIS B 0659-1:2002 Annex 1 (Reference) Comparative Surface Roughness Standard Piece. Is. The male surface has a maximum height roughness (nominal value of Rz) of 1.6 μm, which is specified in Table 2 of JIS B 0659-1:2002 Annex 1 (Reference) Comparative Surface Roughness Standard Piece. ..
Battery size 1: Width of recess 30 mm, length 90 mm, molding depth 3 mm
Battery size 2: Width of recess is 94 mm, length is 128 mm, molding depth is 3 mm
In addition, in Example 4, the molding depths of the battery size 1 and the battery size 2 were each 2 mm, and in Comparative Example 4, the molding depths of the battery size 1 and the battery size 2 were each 1.5 mm.

Next, as shown in the schematic view of FIG. 5, an acrylic plate 20 having a width of 27 mm, a length of 87 mm, and a height of 3 mm is inserted into the recess of the battery size 1, and a width of 91 mm is inserted into the recess of the battery size 2. An acrylic plate 20 having a length of 125 mm and a height of 3 mm (corresponding to the direction of the molding depth) was inserted. The inserted acrylic plate 20 was fixed using double-faced tape NO751B manufactured by Teraoka Seisakusho so that it would be in close contact with the bottom of the recess of the battery packaging material. Next, a double-sided tape 30 having a width of 5 mm and a length of 50 mm as a masking tape (#610 manufactured by 3M, thickness 120 μm) and an aluminum alloy foil 40 (35 μm) were used as a masking tape on the surface 10a of the molded portion of the battery packaging material. ) Are laminated and the aluminum alloy foil 40 is reciprocated once with a rubber roller of 200 g from above the aluminum alloy foil 40, whereby the double-sided tape 30 is attached to the surface 10 a of the molded portion of the battery packaging material 10 on the convex side. Next, the end portion 30a of the double-sided tape that is not attached to the convex portion of the molding portion is pinched with a finger, and the double-sided tape 30 is pulled together with the aluminum alloy foil in the 180° direction (the direction of the arrow in FIG. 5) to project the convex portion of the molding portion. The surface was peeled off from the surface 10a. Next, the surface of the molded part from which the double-sided tape 30 was peeled was visually observed, and the tape peelability was evaluated according to the following criteria. Table 2 shows the evaluation results of the tape peelability.
A: Since the molded part did not follow the tape, no wrinkles were formed on the surface, and the tape was appropriately peeled from the surface of the battery packaging material.
C: The molding portion follows the tape, and wrinkles are formed on the surface.

DESCRIPTION OF SYMBOLS 1... Base material layer 2... Adhesive layer 3... Barrier layer 4... Heat-fusible resin layer 5... Adhesive layer 6... Surface coating layer 10... Battery packaging material 10a... Convex part side of molded part of battery packaging material Surface 20... Acrylic plate 30... Double-sided tape 40... Aluminum alloy foil

Claims (9)

At least a base material layer, a barrier layer, and a heat-fusible resin layer, which is composed of a laminate provided in this order,
The thickness of the laminate is 50 μm or more and 120 μm or less,
The barrier layer has a thickness of 15 μm or more and 40 μm or less,
A packaging material for a battery, wherein the laminate has a bending stiffness of 0.60 gf·cm ² /cm or more and 6.0 gf·cm ² /cm or less. The battery packaging material according to claim 1, wherein the barrier layer is made of an aluminum alloy foil or a stainless steel foil. The battery packaging material according to claim 1, further comprising a surface coating layer containing an additive on a surface of the base material layer opposite to the barrier layer. The battery packaging material according to claim 1, wherein the base material layer has a thickness of 25 μm or less. The puncture strength when punctured from the side of the base material layer of the laminate, measured by a method in conformity with JIS Z1707: 1997, is 5N or more and 55N or less, and any one of claims 1 to 4. The packaging material for a battery according to. The tensile elastic modulus in a direction perpendicular to the laminating direction of the laminate, which is measured by a method in conformity with JIS K7127:1999, is 3.0 GPa or more and 10.0 GPa or less. The packaging material for a battery according to. The battery packaging material according to any one of claims 1 to 6, wherein the heat-fusible resin layer contains a polyolefin. The packaging material for a battery according to claim 1, wherein the base material layer contains at least one of a polyester resin and a polyamide resin. A battery in which a battery element including at least a positive electrode, a negative electrode, and an electrolyte is housed in a package formed of the battery packaging material according to any one of claims 1 to 8.