JP7136108B2 - Battery packaging materials and batteries - Google Patents

Description

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

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

On the other hand, in recent years, with the increasing performance of electric vehicles, hybrid electric vehicles, personal computers, cameras, mobile phones, etc., batteries are required to have various shapes and to be thinner and lighter. However, metal battery packaging materials, which have been widely used in the past, have drawbacks in that it is difficult to follow the diversification of shapes and there is a limit to weight reduction.

Therefore, in recent years, a film-like laminate in which a substrate layer/barrier layer/thermal adhesive resin layer is laminated in order has been developed as a battery packaging material that can be easily processed into various shapes and can be made thinner and lighter. A body has been proposed (see, for example, US Pat.

In such a battery packaging material, generally, recesses are formed by cold forming, battery elements such as electrodes and electrolyte are arranged in the spaces formed by the recesses, and the heat-sealable resin layers are bonded together. By heat-sealing, a battery in which the battery element is housed inside the battery packaging material can be obtained.

JP 2008-287971 A

In recent years, along with the demand for smaller and thinner batteries, there is a demand for even thinner packaging materials for batteries. However, when the battery packaging material is made thinner, the barrier layer is also made thinner, and cracks and pinholes are likely to occur during molding, resulting in a problem of reduced moldability.

In the manufacturing process of the battery, from the viewpoint of suppressing discoloration due to adhesion of the electrolyte to the surface of the battery and damage to the surface of the battery, the surface of the battery (that is, the battery element is sealed) A masking tape is attached to the surface of the battery packaging material (the surface of the battery packaging material on which the battery is exposed) and may be peeled off before the battery is used. However, when the battery packaging material and the barrier layer are 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. A gap may be formed between the packaging material and the cell composed of the positive electrode/separator/negative electrode. If this happens, the electrolyte will move from the cell to the voids, causing a decrease in battery performance. It may scratch the protective resin layer and cause corrosion.

Under such circumstances, the present invention provides a battery packaging material comprising a laminate comprising at least a substrate layer, a barrier layer, and a heat-fusible resin layer in this order. Although both the thickness of the laminate and the thickness of the barrier layer are thin, it has a predetermined moldability, and when peeling off the masking tape attached to the surface of the base layer side Another object of the present invention is to provide a battery packaging material that is difficult to follow the masking tape and effectively suppresses the formation of wrinkles.

The present inventors have made earnest studies to solve the above problems. As a result, the laminate is composed of at least a substrate layer, a barrier layer, and a heat-fusible resin layer in this order, and the laminate has a thickness of 50 μm or more and 120 μm or less. A battery packaging material having a thickness of 15 μm or more and 40 μm or less and a laminate having a bending stiffness of 0.60 gf·cm ² /cm or more and 6.0 gf·cm ² /cm or less constitutes a battery packaging material. Although both the thickness of the laminate and the thickness of the barrier layer are thin, it has a predetermined moldability, and when peeling off the masking tape attached to the surface of the base layer side In addition, the inventors have 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 through further studies based on these findings.

That is, the present invention provides inventions in the following aspects.
Section 1. Consists of a laminate comprising at least a substrate layer, a barrier layer, and a heat-fusible resin layer in this order,
The laminate has a thickness of 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 battery packaging material, 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.
Section 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.
Section 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. Any one of items 1 to 4, wherein the piercing strength when the laminate is pierced from the base layer side is 5 N or more and 55 N or less, measured by a method conforming to the provisions of JIS Z1707:1997. A packaging material for the described battery.
Item 6. Any one of items 1 to 5, wherein the tensile modulus of elasticity in the direction perpendicular to the lamination direction of the laminate is 3.0 GPa or more and 10.0 GPa or less, measured by a method conforming to the provisions of JIS K7127:1999. A packaging material for the described battery.
Item 7. Item 7. The battery packaging material according to any one of Items 1 to 6, wherein the heat-sealable resin layer contains 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. Item 9. A battery, wherein a battery element comprising at least a positive electrode, a negative electrode, and an electrolyte is housed in a package formed of the battery packaging material according to any one of items 1 to 8.

The present invention provides a battery packaging material comprising a laminate comprising at least a substrate layer, a barrier layer, and a heat-fusible resin layer in this order. Although the thickness and the thickness of the barrier layer are both thin, the battery packaging material has a predetermined moldability, and when peeling off the masking tape attached to the surface of the base layer side, the battery packaging material Therefore, it is possible to provide a battery packaging material in which the formation of wrinkles is effectively suppressed. Moreover, according to the present invention, it is also possible to provide a method for manufacturing the battery packaging material and a battery using the battery packaging material.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows an example of the cross-sectional structure of the packaging material for batteries of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows an example of the cross-sectional structure of the packaging material for batteries of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows an example of the cross-sectional structure of the packaging material for batteries of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows an example of the cross-sectional structure of the packaging material for batteries of this invention. It is a schematic diagram for demonstrating the evaluation method of tape peelability in an Example.

The battery packaging material of the present invention is composed of a laminate comprising at least a substrate 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 thickness of the barrier layer is 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. and when the masking tape attached to the surface of the substrate layer is peeled off, the battery packaging material is less likely to follow the masking tape, and wrinkles are effectively formed. suppressed by The battery packaging material of the present invention will be described in detail below.

In this specification, the numerical range indicated by "-" means "more than" and "less than". 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 comprises at least a substrate 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 substrate layer 1 is the outermost layer, and the heat-fusible resin layer 4 is the innermost layer. That is, when the battery is assembled, the heat-sealable resin layers 4 positioned at 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 have an adhesive layer 2 between the base material layer 1 and the barrier layer 3, as shown in FIGS. 2 to 4, for example. Also, 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 . Furthermore, as shown in FIG. 4, a surface coating layer 6 may be provided on the outer side of the base material layer 1 (the side opposite to the heat-sealable 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 in spite of its extremely thin thickness. In addition, when a masking tape is attached to the surface of the base material layer, when the masking tape is peeled off, it is difficult for the battery packaging material 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. Further, 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. Preferred ranges for the thickness of the laminate are 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, and about 55 to 90 μm. , approx. The thickness of the laminate constituting the battery packaging material 10 can be measured using a commercially available thickness gauge.

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, although the battery packaging material 10 of the present invention is very thin, the bending stiffness of the laminate is set within such a specific range, so that it can be formed into a predetermined shape. In addition, when a masking tape is attached to the surface of the base material layer, when the masking tape is peeled off, it is difficult for the battery packaging material to follow the masking tape, and wrinkles are formed. is effectively suppressed.

The bending stiffness of the laminate constituting the battery packaging material 10 of the present invention may be within the above range. 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 still more 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, and about 1.55 gf·cm ² /cm. These include: The preferred range of the bending stiffness is about 0.60 to 5.00 gf·cm ² /cm, about 0.60 to 1.60 gf·cm ² /cm, and about 0.60 to 1.55 gf·cm ² /cm. , about 0.65 to 6.00 gf.cm ² /cm, about 0.65 to 5.00 gf.cm 2 /cm, about 0.65 to 1.60 gf.cm ² /cm, about 0.65 to 1.55 gf. about 0.70 to 6.00 gf·cm ² /cm, about 0.70 to 5.00 gf·cm ² /cm, about 0.70 to 1.60 gf·cm ² /cm, about 0.70 to 5.00 gf·cm ² /cm 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, and about 0.80 to 1.55 gf·cm ² /cm.

The bending stiffness of the laminate constituting the battery packaging material 10 can be adjusted by, for example, the thickness and composition of the layers constituting 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>
A test sample is obtained by cutting the battery packaging material 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. The obtained test sample is measured for bending stiffness (gf·cm ² /cm) using a commercially available bending stiffness measuring machine. The measurement conditions were a curvature change rate of 0.1/cm·sec, a clamp interval of 1 cm, a maximum curvature of 2.5 cm ⁻¹ , an average bending stiffness of 10 test samples, and a bending stiffness of the battery packaging material. and The test sample is fixed to the two clamps so that the edge of the test sample with a width of 80 mm is aligned with the axial direction of the clamps.

From the viewpoint of reducing the thickness of the battery packaging material, exhibiting a predetermined formability, and suppressing wrinkles due to peeling of the masking tape, the laminate constituting the battery packaging material 10 of the present invention conforms to JIS Z1707. : The piercing strength when pierced from the substrate layer side, measured by a method conforming to the provisions of 1997, is preferably in the range of 5 to 55 N, and preferably in the range of 5 to 40 N. More preferably, it is in 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 piercing strength from the substrate layer side of the laminate constituting the battery packaging material is measured by a method conforming to JIS Z1707:1997. Specifically, in a measurement environment of 23 ± 2 ° C. and relative humidity (50 ± 5)%, the test piece is fixed with a table with a diameter of 115 mm having an opening of 15 mm in the center and a pressing plate. A semicircular needle with a tip shape radius of 0.5 mm is pierced at a speed of 50±5 mm per minute, and the maximum stress until the needle penetrates is measured. The number of test pieces is 5, and the average value is obtained. In addition, when the number of test pieces is insufficient to measure 5, the number that can be measured is measured and the average value is obtained.

In addition, from the viewpoint of reducing the thickness of the battery packaging material while exhibiting a predetermined moldability and 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 of elasticity in the direction perpendicular to the lamination direction of the laminate, measured by a method conforming to the provisions of JIS K7127:1999, is preferably in the range of 3.0 to 10.0 GPa, preferably 3.8 to It is more preferably in the range of 9.5 GPa.

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

<Measurement of tensile modulus>
A test sample is obtained by cutting the battery packaging material into a rectangle having a width of 15 mm and a length of 100 mm. Next, in accordance with JIS K7127:1999, the tensile modulus of elasticity in tension is calculated by pulling the test sample under conditions of a gauge length of 30 mm and a tensile speed of 50 mm/min in the longitudinal direction of the test sample. The length of the test sample need not be 100 mm as long as the test can be performed under the above measurement conditions.

Examples of masking tapes include adhesive tapes using rubber-based components, acrylic-based components, urethane-based components, silicone-based components, and styrene-isoprene block copolymer (SIS)-based components as adhesive components. , such adhesive tapes are readily available on the market.

2. Each layer forming the battery packaging material [base layer 1]
In the battery packaging material of the present invention, the substrate layer 1 is the outermost layer. The material forming the base material layer 1 is not particularly limited as long as it has insulating properties. Materials for forming the substrate layer 1 include, for example, polyester resins, polyamide resins, epoxy resins, acrylic resins, fluororesins, polyurethane resins, silicon resins, phenolic resins, polycarbonates, and resin films such as mixtures and copolymers thereof. is mentioned. Among these, polyester resins and polyamide resins are preferred, and biaxially stretched polyester resins and biaxially stretched polyamide resins are more preferred. Specific examples of polyester resins include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, and copolymerized polyester. Specific examples of polyamide resins include nylon 6, nylon 66, copolymers of nylon 6 and nylon 66, nylon 6,10, and polymetaxylylene adipamide (MXD6).

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

The substrate layer 1 may be formed of a single layer of resin film, but may be formed of two or more layers of resin film in order to improve pinhole resistance and insulation. Specific examples 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, a multilayer structure in which a plurality of polyester films are laminated, and the like. When the substrate layer 1 has a multilayer structure, a laminate of a biaxially stretched nylon film and a biaxially stretched polyester film, a laminate of a plurality of biaxially stretched nylon films, and a laminate of a plurality of biaxially stretched polyester films. body is preferred. For example, when the base material layer 1 is formed from two layers of resin films, a structure in which a polyester resin and a polyester resin are laminated, a structure in which a polyamide resin and a polyamide resin are laminated, or a structure in which a polyester resin and a polyamide resin are laminated. is preferred, 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 is more preferred. In addition, since the polyester resin does not easily discolor when the electrolytic solution adheres to the surface, it is preferable to laminate the base material layer 1 so that the polyester resin is positioned as the outermost layer in the laminate structure. When the substrate layer 1 has a multilayer structure, the thickness of each layer is preferably about 2 to 10 μm.

When the substrate 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. are the same as those for the adhesive layer 2, which will be described later. The method for laminating two or more layers of resin films is not particularly limited, and known methods can be employed, such as a dry lamination method and a sandwich lamination method, preferably a dry lamination method. When laminating by a dry lamination method, it is preferable to use a urethane-based adhesive as the adhesive layer. At this time, the thickness of the adhesive layer is, for example, about 2 to 5 μm. When the base material layer 1 is composed of a multilayer resin film, the thickness of the base material layer 1 does not include the adhesive part because it does not substantially contribute to moldability.

In the present invention, from the viewpoint of improving the moldability of the battery packaging material, it is preferable that the surface of the substrate layer 1 is coated with a lubricant. The lubricant is not particularly limited, but preferably includes an amide-based lubricant. Specific examples of the amide-based lubricant include those exemplified for the heat-fusible resin layer 4 described later.

When a lubricant exists on the surface of the base material layer 1, its amount is not particularly limited, but in an environment with a temperature of 24° C. and a relative humidity of 60%, it is preferably about 3 mg/m ² or more, more preferably 4 to 4 mg/m 2 . About 15 mg/m ² , more preferably about 5 to 14 mg/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 obtained by exuding the lubricant contained in the resin constituting the base material layer 1, or by coating the surface of the base material layer 1 with the lubricant. may be

The thickness of the base material layer 1 is not particularly limited as long as it functions as a base 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. Preferable ranges of the base material layer 1 include about 3 to 15 μm, about 3 to 10 μm, about 4 to 15 μm, and about 4 to 10 μm.

The substrate layer 1 is a polyethylene terephthalate film with a thickness of about 3 to 10 μm from the viewpoint of reducing the thickness of the battery packaging material while exhibiting a predetermined moldability and suppressing wrinkles due to peeling of the masking tape. It is particularly preferable to be configured by

[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 necessary in order to firmly bond them.

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

Specific examples of adhesive components that can be used to form the adhesive layer 2 include polyester-based resins such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, polycarbonate, and copolymerized polyester; Polyether-based adhesive; polyurethane-based adhesive; epoxy-based resin; phenolic resin-based resin; nylon 6, nylon 66, nylon 12, polyamide-based resin such as copolyamide; Polyolefin resins, polyvinyl acetate resins; cellulose adhesives; (meth)acrylic resins; polyimide resins; amino resins such as urea resins and melamine resins; Examples include silicone-based resins. These adhesive components may be used singly or in combination of two or more. Among these adhesive components, polyurethane-based adhesives are preferred.

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

For example, specific examples of inorganic pigments preferably include carbon black and titanium oxide. Further, specific examples of organic pigments preferably include azo pigments, phthalocyanine pigments, condensed polycyclic pigments, and the like. 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; Examples of metal phthalocyanine pigments include blue pigments and green pigments, and examples of condensed polycyclic pigments include dioxazine violet and quinacridone violet. Pearl pigments and fluorescent pigments can also be used as pigments.

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

The average particle size of the pigment is not particularly limited, and is, for example, approximately 0.05 to 5 μm, preferably approximately 0.08 to 2 μm. The average particle size of the pigment is the median size measured with a laser diffraction/scattering particle size distribution analyzer.

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

A colored layer may be provided between the substrate layer 1 and the adhesive layer 2 . The colored layer can be formed, for example, by applying ink containing a coloring agent to the surface of the substrate layer 1 . Known substances such as pigments and dyes can be used as the colorant. In addition, 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 known inks can be used. Specific examples of inks include, for example, inks containing colorants, diamines, polyols, and curing agents. As the solvent contained in the ink, a known solvent can be used, for example, toluene.

The thickness of the adhesive layer 2 is not particularly limited as long as it exhibits an adhesive function, but it 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 is a layer that has the function of improving the strength of the battery packaging material and also preventing water vapor, oxygen, light, etc. from entering the battery. The barrier layer 3 is preferably a metal layer, that is, a layer made of metal. Specific examples of the metal forming the barrier layer 3 include aluminum alloy foil, stainless steel foil, titanium, and the like, preferably aluminum alloy foil or stainless steel foil. From the viewpoint of preventing the occurrence of wrinkles and pinholes in the barrier layer 3 during the production of the battery packaging material, the barrier layer is made of, 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 other soft aluminum alloy foils are more preferable.

Stainless steel foils include austenitic stainless steel foils and ferritic stainless steel foils. In the present invention, the stainless steel foil 3 is an austenitic stainless steel from the viewpoint of providing a battery packaging material that has high rigidity, is less likely to wrinkle when the tape is peeled off, and has excellent formability. It is preferably made of steel. Specific examples of the austenitic stainless steel that constitutes the stainless steel foil 3 include SUS304, SUS301, SUS316L, etc. Among these, the SUS304, SUS301, SUS316L, and the like are mentioned. SUS304 is particularly preferable from the viewpoint of use as a packaging material.

The thickness of the barrier layer 3 is in the range of 15-40 μm. In the battery packaging material 10 of the present invention, the bending stiffness of the laminate is set within a specific range in spite of not only the thickness of the battery packaging material but also the thickness of the barrier layer being thin. As a result, predetermined moldability can be exhibited, and when the masking tape is attached to the surface of the base material layer, the battery packaging material follows the masking tape when the masking tape is peeled off. The formation of wrinkles is effectively suppressed. The lower limit of the thickness of the barrier layer 3 is preferably about 20 μm or more from the viewpoint of reducing the thickness of the battery packaging material while exhibiting a predetermined moldability and suppressing wrinkles due to peeling of the masking tape. The upper limit is preferably about 40 μm or less, more preferably about 35 μm or less. Up to about 30 μm can be mentioned. 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 about 15 μm or more. About 40 μm or less is mentioned, and preferable ranges of the thickness include 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. Preferred ranges for the thickness include 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.

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

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

In addition, as a chemical conversion treatment method for imparting corrosion resistance to the barrier layer 3, fine particles of metal oxides such as aluminum oxide, titanium oxide, cerium oxide, and tin oxide, and barium sulfate are dispersed in phosphoric acid. 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 can be mentioned. A resin layer obtained by cross-linking a cationic polymer with a cross-linking agent may be further formed on the acid-resistant film. Examples of the cationic polymer include polyethyleneimine, an ionic polymer complex composed of a polymer containing polyethyleneimine and carboxylic acid, a primary amine-grafted acrylic resin obtained by graft-polymerizing a primary amine to an acrylic backbone, and polyallylamine. or derivatives thereof, aminophenol and the like. As these cationic polymers, only one type may be used, or two or more types may be used in combination. Examples of cross-linking agents include compounds having at least one functional group selected from the group consisting of isocyanate groups, glycidyl groups, carboxyl groups, and oxazoline groups, and silane coupling agents. As these cross-linking agents, only one type may be used, or two or more types may be used in combination.

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

Further, as other specific methods for providing the acid-resistant film, for example, at least the inner layer side surface of the aluminum alloy foil is first subjected to an alkali immersion method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method, an acid An acid-resistant film can be formed by performing a degreasing treatment by a well-known treatment method such as an activation method, and then subjecting the degreased surface to a well-known anodizing treatment.

Other examples of the acid-resistant coating include phosphate-based and chromic acid-based coatings. Phosphate type includes zinc phosphate, iron phosphate, manganese phosphate, calcium phosphate, chromium phosphate and the like, and chromic acid type includes chromium chromate and the like.

Further, as another example of the acid-resistant film, by forming an acid-resistant film of phosphate, chromate, fluoride, triazinethiol compound, or the like, it is possible to improve the adhesion between the aluminum and the base layer during embossing. Prevention of delamination, prevention of dissolution and corrosion of the aluminum surface, especially dissolution and corrosion of aluminum oxide existing on the aluminum surface, and adhesion of the aluminum surface by hydrogen fluoride generated by the reaction between the electrolyte and moisture. It exhibits the effect of improving wettability, preventing delamination between the base material layer and aluminum during heat-sealing, and preventing delamination between the base material layer and aluminum during press molding in the embossed type. Among the substances that form an acid-resistant film, an aqueous solution composed of three components, phenolic resin, chromium (III) fluoride compound, and phosphoric acid, is applied to the surface of aluminum, followed by dry baking.

Further, the acid-resistant film 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 phosphate is the About 1 to 100 parts by mass may be blended with 100 parts by mass of cerium oxide. It is preferable that the acid-resistant film has a multi-layer structure further including a layer having a cationic polymer and a cross-linking agent for cross-linking the cationic polymer.

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

Further, the phosphoric acid or phosphate is preferably condensed phosphoric acid or condensed phosphate.

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

Specific examples of acid-resistant coatings include those containing at least one of phosphates, chromates, fluorides, and triazinethiols. An acid-resistant film containing a cerium compound is also preferred. As the cerium compound, cerium oxide is preferred.

Further, specific examples of acid-resistant coatings include phosphate-based coatings, chromate-based coatings, fluoride-based coatings, and triazinethiol compound coatings. The acid-resistant coating may be one of these, or may be a combination of multiple types. Furthermore, as the acid-resistant film, after degreasing the chemically treated surface of the aluminum alloy foil, a treatment liquid consisting of a mixture of a metal phosphate and a water-based synthetic resin, or a mixture of a non-metal phosphate and a water-based synthetic resin It may be formed of a treatment liquid consisting of

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

It is preferable that the surface of the aluminum alloy foil or 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 presence of at least one element selected from the group consisting of phosphorus, chromium and cerium in the acid-resistant film on the surface of the aluminum alloy foil or stainless steel foil of the battery packaging material is confirmed by X-ray photoelectron spectroscopy. can be checked 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 stainless steel foil is placed in an electric furnace, and organic components present on the surface of the aluminum alloy foil or stainless steel foil are removed at about 300° C. for about 30 minutes. After that, the inclusion of these elements is confirmed using X-ray photoelectron spectroscopy of the surface of the aluminum alloy foil or stainless steel foil.

The amount of the acid-resistant film formed on the surface of the barrier layer ³ in the chemical conversion treatment is not particularly limited. About 0.5 to 50 mg, preferably about 1.0 to 40 mg, in terms of phosphorus compound, about 0.5 to 50 mg, preferably about 1.0 to 40 mg in terms of phosphorus, and aminated phenol polymer is 1.0 It is desired to be contained in a ratio of about 200 mg, preferably about 5.0 to 150 mg.

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

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

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

The resin component used for the heat-fusible resin layer 4 is not particularly limited as long as it is heat-fusible, and examples thereof include polyolefins, cyclic polyolefins, acid-modified polyolefins, and acid-modified cyclic polyolefins. 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. Whether 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, or the like, and the analysis method is not particularly limited. For example, when maleic anhydride-modified polyolefin is measured by infrared spectroscopy, peaks derived from maleic anhydride are detected near wavenumbers of 1760 cm ⁻¹ and 1780 cm ⁻¹ . However, if the degree of acid denaturation 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, block copolymers of polypropylene (for example, block copolymers of propylene and ethylene), and polypropylene. polypropylene, such as random copolymers of (eg, random copolymers of propylene and ethylene); terpolymers of ethylene-butene-propylene; Among these polyolefins, polyethylene and polypropylene are preferred.

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

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

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

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

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

In the present invention, from the viewpoint of improving the moldability of the battery packaging material, it is preferable that a lubricant is adhered to the surface of the heat-fusible resin layer. The lubricant is not particularly limited, but preferably includes an amide-based lubricant. Specific examples of amide-based lubricants include saturated fatty acid amides, unsaturated fatty acid amides, substituted amides, methylolamides, saturated fatty acid bisamides, and unsaturated fatty acid bisamides. Specific examples of saturated fatty acid amides 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 substituted amides include N-oleyl palmitic acid amide, N-stearyl stearic acid amide, N-stearyl oleic acid amide, N-oleyl stearic acid amide, N-stearyl erucic acid amide and the like. Further, specific examples of methylolamide include methylol stearamide. Specific examples of saturated fatty acid bisamides include methylenebisstearic acid amide, ethylenebiscapric acid amide, ethylenebislauric acid amide, ethylenebisstearic acid amide, ethylenebishydroxystearic acid amide, ethylenebisbehenic acid amide, hexamethylenebisstearin. acid amide, hexamethylenebisbehenamide, hexamethylenehydroxystearic acid amide, N,N'-distearyladipic acid amide, N,N'-distearylsebacic acid amide and the like. Specific examples of unsaturated fatty acid bisamides include ethylenebisoleic acid amide, ethylenebiserucic acid amide, hexamethylenebisoleic acid amide, N,N'-dioleyladipic acid amide, and N,N'-dioleylsebacic acid amide. etc. Specific examples of fatty acid ester amides include stearamide ethyl stearate. Further, specific examples of the aromatic bisamide include m-xylylenebisstearic acid amide, m-xylylenebishydroxystearic acid amide, N,N'-distearyl isophthalic acid amide and the like. Lubricants may be used singly or in combination of two or more.

When a lubricant exists on the surface of the heat-sealable resin layer ⁴ , the amount of the lubricant is not particularly limited. 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 obtained by exuding the lubricant contained in the resin constituting the heat-fusible resin layer 4, 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 it functions as a heat-fusible resin layer. From the viewpoint of 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 mentioned. Preferred ranges for the thickness of the heat-fusible resin layer include about 8 to 30 μm, about 8 to 25 μm, about 10 to 30 μm, and about 10 to 25 μm.

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

The adhesive layer 5 is made of a resin capable of bonding the barrier layer 3 and the heat-fusible resin layer 4 together. As the resin used to form the adhesive layer 5, the same adhesives as those exemplified for the adhesive layer 2 can be used in terms of the adhesive mechanism, the types of adhesive components, and the like. As the resin used to form the adhesive layer 5, polyolefin-based resins such as polyolefins, cyclic polyolefins, carboxylic acid-modified polyolefins, and carboxylic acid-modified cyclic polyolefins exemplified for the heat-sealable resin layer 4 can also be used. . From the viewpoint of excellent adhesion between the barrier layer 3 and the heat-fusible resin layer 4, the polyolefin is preferably carboxylic acid-modified polyolefin, and particularly preferably 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. Whether the resin constituting the adhesive layer 5 contains a polyolefin skeleton can be analyzed by, for example, infrared spectroscopy, gas chromatography mass spectrometry, or the like, and the analysis method is not particularly limited. For example, when maleic anhydride-modified polyolefin is measured by infrared spectroscopy, peaks derived from maleic anhydride are detected near wavenumbers of 1760 cm ⁻¹ and 1780 cm ⁻¹ . However, if the degree of acid denaturation is low, the peak may be too small to be detected. In that case, it can be analyzed by nuclear magnetic resonance spectroscopy.

Furthermore, from the viewpoint of making the battery packaging material excellent in shape stability after molding while reducing the thickness of the battery packaging material, the adhesive layer 5 is 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 carboxylic acid-modified polyolefin and carboxylic acid-modified cyclic polyolefin exemplified for the heat-sealable resin layer 4 can be preferably exemplified.

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

The epoxy-based curing agent is not particularly limited as long as it is a compound having at least one epoxy group. Examples of epoxy-based curing agents include epoxy resins such as bisphenol A diglycidyl ether, modified bisphenol A diglycidyl ether, novolac glycidyl ether, glycerin polyglycidyl ether, and polyglycerin polyglycidyl ether.

The polyfunctional isocyanate-based curing agent is not particularly limited as long as it is a compound having two or more isocyanate groups. Specific examples of polyfunctional isocyanate curing agents include isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), polymers and nurates thereof, and Mixtures and copolymers with other polymers may be mentioned.

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

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

From the viewpoint of enhancing the adhesion between the 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. Up to about 5 μm can be mentioned. In the case of using the resin exemplified for the heat-fusible resin layer 4, the thickness is preferably about 2 to 25 μm, more preferably about 10 to 20 μm. In the case of a cured product of an acid-modified polyolefin and a curing agent, the thickness is preferably about 10 μm or less, more preferably about 0.1 to 10 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, for the purpose of improving design, electrolyte resistance, scratch resistance, moldability, etc., on the substrate layer 1 (barrier layer of the substrate layer 1) 3), a surface coating layer 6 may be provided, if necessary. The surface coating layer 6 is the outermost layer when the battery is assembled.

The surface coating layer 6 can be made of, for example, polyvinylidene chloride, polyester resin, urethane resin, acrylic resin, epoxy resin, or the like. Among these, the surface coating layer 6 is preferably formed of a two-liquid curing resin. Examples of the two-liquid curable resin forming the surface coating layer 6 include a two-liquid curable urethane resin, a two-liquid curable polyester resin, and a two-liquid curable epoxy resin. Further, the surface coating layer 6 may contain additives.

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. The shape of the additive is also not particularly limited, but examples thereof include spherical, fibrous, plate-like, amorphous, and balloon-like shapes. Specific examples of additives include talc, silica, graphite, kaolin, montmorilloid, montmorillonite, synthetic mica, hydrotalcite, silica gel, zeolite, aluminum hydroxide, magnesium hydroxide, zinc oxide, magnesium oxide, aluminum oxide, Neodymium oxide, antimony oxide, titanium oxide, cerium oxide, calcium sulfate, barium sulfate, calcium carbonate, calcium silicate, lithium carbonate, calcium benzoate, calcium oxalate, magnesium stearate, alumina, carbon black, carbon nanotubes, high melting point nylon, crosslinked acrylic, crosslinked styrene, crosslinked polyethylene, benzoguanamine, gold, aluminum, copper, nickel, and the like. These additives may be used singly or in combination of two or more. Among these additives, silica, barium sulfate, and titanium oxide are preferred from the viewpoint of dispersion stability and cost. In addition, the additive may be subjected to various surface treatments such as insulation treatment and high-dispersion treatment.

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

A method for forming the surface coating layer 6 is not particularly limited, but for example, a method of coating one surface of the substrate layer 1 with a two-liquid curing resin that forms the surface coating layer 6 can be used. When an additive is blended, the additive may be added to the two-liquid curing resin, mixed, and then applied.

The thickness of the surface coating layer 6 is not particularly limited as long as it exhibits the above functions as the surface coating layer 6, and is, for example, approximately 0.5 to 10 μm, preferably approximately 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 laminate obtained by laminating each layer having a predetermined composition can be obtained.

An example of the method for producing the battery packaging material of the present invention is as follows. First, a layered body (hereinafter also referred to as "layered body A") is formed by laminating a substrate layer 1, an adhesive layer 2, and a barrier layer 3 in this order. Specifically, the laminate A is formed by applying an adhesive used for forming the adhesive layer 2 to the base material layer 1 or the barrier layer 3 whose surface is chemically treated as necessary, by gravure coating, roll After coating and drying by a coating method such as a coating method, the barrier layer 3 or the base material layer 1 is laminated and the adhesive layer 2 is cured by a dry lamination method.

Next, on the barrier layer 3 of the laminate A, the adhesive layer 5 and the heat-fusible resin layer 4 are laminated 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-extrusion (co-extrusion lamination method); and a heat-fusible resin layer 4 are laminated, and this is laminated on the barrier layer 3 of the laminate A by a thermal lamination method. An adhesive for forming the layer 5 is applied by extrusion or solution coating, and laminated by a method such as drying at a high temperature or baking. A method of laminating by a thermal lamination method, (4) Bonding while pouring a melted adhesive layer 5 between the barrier layer 3 of the laminate A and the heat-fusible resin layer 4 previously formed into a sheet form. A method of laminating the laminate A and the heat-fusible resin layer 4 with the layer 5 interposed therebetween (sandwich lamination method) can be used.

When providing the surface coating layer 6 , the surface coating layer 6 is laminated on the surface of the substrate layer 1 opposite to the barrier layer 3 . The surface coating layer 6 can be formed, for example, by coating the surface of the substrate layer 1 with the above-described resin for forming the surface coating layer 6 . 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 substrate layer 1 , the barrier layer 3 may be formed on the surface of the substrate layer 1 opposite to the surface coating layer 6 .

Surface coating layer 6/base layer 1/adhesive layer 2 optionally provided/barrier layer 3/adhesive layer 5 optionally provided with surface chemical conversion treatment as described above / A laminated body consisting of the heat-fusible resin layer 4 is formed. You may use for heat processing, such as a far-infrared type. Conditions for such heat treatment include, for example, 150 to 250° C. for 1 to 5 minutes.

In the battery packaging material of the present invention, each layer constituting the laminate, if necessary, improves or stabilizes film formability, lamination processing, final product secondary processing (pouching, embossing) aptitude, etc. For this purpose, surface activation treatment such as corona treatment, blast treatment, oxidation treatment and ozone treatment may be applied.

4. Use of Battery Packaging Material The battery packaging material of the present invention is used as a package for hermetically housing battery elements such as a positive electrode, a negative electrode and an electrolyte. That is, a battery can be made by housing a battery element including at least a positive electrode, a negative electrode, and an electrolyte in a package formed of the battery packaging material of the present invention.

Specifically, a battery element comprising at least a positive electrode, a negative electrode, and an electrolyte is wrapped in the battery packaging material of the present invention in a state in which metal terminals connected to the positive electrode and the negative electrode protrude outward. By covering the periphery of the element so as to form a flange portion (area where the heat-fusible resin layers contact each other), and sealing the heat-fusible resin layers of the flange portion by heat-sealing, A battery using the battery packaging material is provided. When a battery element is housed in a package formed of the battery packaging material of the present invention, the heat-sealable resin portion of the battery packaging material of the present invention should face the inside (the surface in contact with the battery element). to form a package.

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

In the battery packaging material of the present invention, the heat-fusible resin layer is brought into contact with the electrolyte in a high-temperature environment, and the heat-fusible resin layers are heat-sealed with the electrolyte adhered to the heat-fusible resin layer. High sealing strength is exhibited by heat fusion even when it is sealed. Therefore, the battery packaging material of the present invention can be particularly suitably used as a battery packaging material for vehicle batteries and mobile device batteries, which are subjected to an aging process in a high-temperature environment.

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

<Manufacturing of packaging materials for batteries>
Battery packaging materials of Examples 1 to 11 and Comparative Examples 1 to 4 were produced by the following procedure. The laminate structure 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 an oriented nylon film, "DL" is an adhesive layer or 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. Also, the numerical value behind each layer means the thickness (μm) of the layer. For example, “SUS20” means “stainless steel foil with a thickness of 20 μm”.

Example 1
A polyethylene terephthalate (PET) film (9 μm thick) was prepared as a substrate layer, and a stainless steel foil (SUS304, 20 μm thick) was prepared as a barrier layer. Next, a two-component urethane adhesive (polyol compound and aromatic isocyanate compound) was applied to one side of the stainless steel foil to form an adhesive layer (3 μm thick) on the barrier layer. Next, after laminating the adhesive layer on the barrier layer and the substrate layer by a dry lamination method, an aging treatment was performed to prepare a laminate of substrate layer/adhesive layer/barrier layer. Both sides of the stainless steel foil are chemically treated. The chemical conversion treatment of the stainless steel foil is carried out by applying a treatment solution consisting of phenolic resin, chromium fluoride compound, and phosphoric acid to the stainless steel foil by a roll coating method so that the coating amount of chromium is 10 mg/m ² (dry mass). It was carried out by coating on both sides and baking. Next, on the barrier layer of each laminate obtained above, maleic anhydride-modified polypropylene as an adhesive layer (thickness 14 μm) and random polypropylene as a heat-fusible resin layer (thickness 10 μm). was co-extruded to laminate the adhesive layer/heat-fusible resin layer on the barrier layer. Next, 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 a filler (average particle By coating silica particles with a diameter of 1.0 μm)) to a thickness of 3 μm, a surface coating layer is formed, and a surface coating layer/base layer/adhesive layer/barrier layer/adhesive layer/thermal melting A battery packaging material was obtained in which the adhesive resin layers were laminated in order.

Example 2
A polyethylene terephthalate (PET) film (9 μm thick) was prepared as a substrate layer, and a stainless steel foil (SUS304, 20 μm thick) was prepared as a barrier layer. Next, a two-component urethane adhesive (polyol compound and aromatic isocyanate compound) was applied to one side of the stainless steel foil to form an adhesive layer (3 μm thick) on the barrier layer. Next, after laminating the adhesive layer on the barrier layer and the substrate layer by a dry lamination method, an aging treatment was performed to prepare a laminate of substrate layer/adhesive layer/barrier layer. Both sides of the stainless steel foil were chemically treated in the same manner as in Example 1. Next, a two-liquid type urethane adhesive (polyol compound and aromatic isocyanate compound) is applied onto the barrier layer of each laminate obtained above, and an adhesive layer (thickness: 2 μm) is formed on the barrier layer. formed. Next, after laminating an adhesive layer on the barrier layer and an unstretched polypropylene film (thickness 23 μm) as a heat-fusible resin layer by a dry lamination method, aging treatment is performed to form an adhesive layer on the barrier layer. / A heat-fusible resin layer was laminated. Next, a surface coating layer is formed by coating the surface of the base material layer of the obtained laminate with the same two-liquid curing type resin as in Example 1 so as to have a thickness of 3 μm. Thus, a battery packaging material was obtained in which /base layer/adhesive layer/barrier layer/adhesive layer/heat-fusible resin layer were laminated in this order.

Example 3
An oriented nylon film (ONy) film (thickness: 10 μm) was prepared as a substrate layer, and a stainless steel foil (SUS304, thickness: 20 μm) was prepared as a barrier layer. Next, a two-component urethane adhesive (polyol compound and aromatic isocyanate compound) was applied to one side of the stainless steel foil to form an adhesive layer (3 μm thick) on the barrier layer. Next, after laminating the adhesive layer on the barrier layer and the substrate layer by a dry lamination method, an aging treatment was performed to prepare a laminate of substrate layer/adhesive layer/barrier layer. Both sides of the stainless steel foil were chemically treated in the same manner as in Example 1. Next, a two-liquid type urethane adhesive (polyol compound and aromatic isocyanate compound) is applied onto the barrier layer of each laminate obtained above, and an adhesive layer (thickness: 2 μm) is formed on the barrier layer. formed. Next, after laminating an adhesive layer on the barrier layer and an unstretched polypropylene film (thickness 23 μm) as a heat-fusible resin layer by a dry lamination method, aging treatment is performed to form an adhesive layer on the barrier layer. / A heat-fusible resin layer was laminated. Next, a surface coating layer is formed by coating the surface of the base material layer of the obtained laminate with the same two-liquid curing type resin as in Example 1 so as to have a thickness of 3 μm. Thus, a battery packaging material was obtained in which /base layer/adhesive layer/barrier layer/adhesive layer/heat-fusible resin layer were laminated in this order.

Example 4
A polyethylene terephthalate (PET) film (4 μm thick) was prepared as a substrate layer, and a stainless steel foil (SUS304, 15 μm thick) was prepared as a barrier layer. Next, a two-component urethane adhesive (polyol compound and aromatic isocyanate compound) was applied to one side of the stainless steel foil to form an adhesive layer (3 μm thick) on the barrier layer. Next, after laminating the adhesive layer on the barrier layer and the substrate layer by a dry lamination method, an aging treatment was performed to prepare a laminate of substrate layer/adhesive layer/barrier layer. Both sides of the stainless steel foil were chemically treated in the same manner as in Example 1. Next, a two-liquid type urethane adhesive (polyol compound and aromatic isocyanate compound) is applied onto the barrier layer of each laminate obtained above, and an adhesive layer (thickness: 2 μm) is formed on the barrier layer. formed. Next, after laminating an adhesive layer on the barrier layer and an unstretched polypropylene film (thickness 23 μm) as a heat-fusible resin layer by a dry lamination method, aging treatment is performed to form an adhesive layer on the barrier layer. / A heat-fusible resin layer was laminated. Next, a surface coating layer is formed by coating the surface of the base material layer of the obtained laminate with the same two-liquid curing type resin as in Example 1 so as to have a thickness of 3 μm. Thus, a battery packaging material was obtained in which /base layer/adhesive layer/barrier layer/adhesive layer/heat-fusible resin layer were laminated in this order.

Example 5
A polyethylene terephthalate (PET) film (4 μm thick) was prepared as the substrate layer, and an aluminum alloy foil (JIS H4160:1994 A8021H-O (35 μm thick)) 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 aluminum alloy foil to form an adhesive layer (3 μm thick) on the barrier layer. Next, after laminating the adhesive layer on the barrier layer and the substrate layer by a dry lamination method, an aging treatment was performed to prepare a laminate of substrate layer/adhesive layer/barrier layer. Both sides of the aluminum alloy foil are chemically treated. The chemical conversion treatment of the aluminum alloy foil is carried out by roll-coating the aluminum alloy foil with a treatment solution consisting of phenolic resin, chromium fluoride compound, and phosphoric acid so that the coating amount of chromium is 10 mg/m ² (dry mass). It was carried out by coating on both sides and baking. Next, on the barrier layer of each laminate obtained above, maleic anhydride-modified polypropylene as an adhesive layer (thickness 14 μm) and random polypropylene as a heat-fusible resin layer (thickness 10 μm). By co-extrusion, the adhesive layer/heat-fusible resin layer is laminated on the barrier layer, and the base layer/adhesive layer/barrier layer/adhesive layer/heat-fusible resin layer are laminated in order. Thus, a battery packaging material was obtained.

Example 6
A polyethylene terephthalate (PET) film (4 μm thick) was prepared as the substrate layer, and an aluminum alloy foil (JIS H4160:1994 A8021H-O (30 μm thick)) 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 aluminum alloy foil to form an adhesive layer (3 μm thick) on the barrier layer. Next, after laminating the adhesive layer on the barrier layer and the substrate layer by a dry lamination method, an aging treatment was performed to prepare a laminate of substrate layer/adhesive layer/barrier layer. Both surfaces of the aluminum alloy foil were chemically treated in the same manner as in Example 5. Next, a two-liquid type urethane adhesive (polyol compound and aromatic isocyanate compound) is applied onto the barrier layer of each laminate obtained above, and an adhesive layer (thickness: 2 μm) is formed on the barrier layer. formed. Next, after laminating an adhesive layer on the barrier layer and an unstretched polypropylene film (thickness 20 μm) as a heat-fusible resin layer by a dry lamination method, aging treatment is performed to form an adhesive layer on the barrier layer. / A heat-fusible resin layer was laminated. Next, a surface coating layer is formed by coating the surface of the base material layer of the obtained laminate with the same two-liquid curing type resin as in Example 1 so as to have a thickness of 3 μm. Thus, a battery packaging material was obtained in which /base layer/adhesive layer/barrier layer/adhesive layer/heat-fusible resin layer were laminated in this order.

Example 7
A polyethylene terephthalate (PET) film (4 μm thick) was prepared as the substrate layer, and an aluminum alloy foil (JIS H4160:1994 A8021H-O (35 μm thick)) 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 aluminum alloy foil to form an adhesive layer (3 μm thick) on the barrier layer. Next, after laminating the adhesive layer on the barrier layer and the substrate layer by a dry lamination method, an aging treatment was performed to prepare a laminate of substrate layer/adhesive layer/barrier layer. Both surfaces of the aluminum alloy foil were chemically treated in the same manner as in Example 5. Next, a two-liquid type urethane adhesive (polyol compound and aromatic isocyanate compound) is applied onto the barrier layer of each laminate obtained above, and an adhesive layer (thickness: 2 μm) is formed on the barrier layer. formed. Next, after laminating an adhesive layer on the barrier layer and an unstretched polypropylene film (thickness 20 μm) as a heat-fusible resin layer by a dry lamination method, aging treatment is performed to form an adhesive layer on the barrier layer. / A heat-fusible resin layer was laminated. Next, a surface coating layer is formed by coating the surface of the base material layer of the obtained laminate with the same two-liquid curing type resin as in Example 1 so as to have a thickness of 3 μm. Thus, a battery packaging material was obtained in which /base layer/adhesive layer/barrier layer/adhesive layer/heat-fusible resin layer were laminated in this order.

Example 8
An oriented nylon film (thickness: 15 μm) was prepared as a substrate layer, and an aluminum alloy foil (JIS H4160:1994 A8021H-O (thickness: 30 μm)) was prepared as a barrier layer. Next, a two-component urethane adhesive (polyol compound and aromatic isocyanate compound) was applied to one surface of the aluminum alloy foil to form an adhesive layer (3 μm thick) on the barrier layer. Next, after laminating the adhesive layer on the barrier layer and the substrate layer by a dry lamination method, an aging treatment was performed to prepare a laminate of substrate layer/adhesive layer/barrier layer. Both surfaces of the aluminum alloy foil were chemically treated in the same manner as in Example 5. Next, on the barrier layer of each laminate obtained above, maleic anhydride-modified polypropylene as an adhesive layer (thickness 14 μm) and random polypropylene as a heat-fusible resin layer (thickness 10 μm). was co-extruded to laminate the adhesive layer/heat-fusible resin layer on the barrier layer. Next, a surface coating layer is formed by coating the surface of the base material layer of the obtained laminate with the same two-liquid curing type resin as in Example 1 so as to have a thickness of 3 μm. Thus, a battery packaging material was obtained in which /base layer/adhesive layer/barrier layer/adhesive layer/heat-fusible resin layer were laminated in this order.

Example 9
An oriented nylon film (ONy) film (thickness: 15 μm) was prepared as a substrate layer, and a stainless steel foil (SUS304, thickness: 40 μm) was prepared as a barrier layer. Next, a two-component urethane adhesive (polyol compound and aromatic isocyanate compound) was applied to one side of the stainless steel foil to form an adhesive layer (3 μm thick) on the barrier layer. Next, after laminating the adhesive layer on the barrier layer and the substrate layer by a dry lamination method, an aging treatment was performed to prepare a laminate of substrate layer/adhesive layer/barrier layer. Both sides of the stainless steel foil were chemically treated in the same manner as in Example 1. Next, a two-liquid type urethane adhesive (polyol compound and aromatic isocyanate compound) is applied onto the barrier layer of each laminate obtained above, and an adhesive layer (thickness: 2 μm) is formed on the barrier layer. formed. Next, after laminating an adhesive layer on the barrier layer and an unstretched polypropylene film (thickness 23 μm) as a heat-fusible resin layer by a dry lamination method, aging treatment is performed to form an adhesive layer on the barrier layer. /Heat-fusible resin layer were laminated to obtain a battery packaging material in which base layer/adhesive layer/barrier layer/adhesive layer/heat-fusible resin layer were laminated in this order.

Example 10
An oriented nylon film (25 μm thick) was prepared as a substrate layer, and an aluminum alloy foil (JIS H4160:1994 A8021H-O (40 μm thick)) was prepared as a barrier layer. Next, a two-component urethane adhesive (polyol compound and aromatic isocyanate compound) was applied to one surface of the aluminum alloy foil to form an adhesive layer (3 μm thick) on the barrier layer. Next, after laminating the adhesive layer on the barrier layer and the substrate layer by a dry lamination method, an aging treatment was performed to prepare a laminate of substrate layer/adhesive layer/barrier layer. Both surfaces of the aluminum alloy foil were chemically treated in the same manner as in Example 5. Next, a maleic anhydride-modified polypropylene as an adhesive layer (23 μm thick) and a random polypropylene as a heat-fusible resin layer (22 μm thick) are placed on the barrier layer of each laminate obtained above. By co-extrusion, the adhesive layer/heat-fusible resin layer is laminated on the barrier layer, and the substrate layer/adhesive layer/barrier layer/adhesive layer/heat-fusible resin layer are laminated in this order. Thus, a battery packaging material was obtained.

Example 11
An oriented nylon film (thickness: 15 μm) was prepared as a substrate layer, and an aluminum alloy foil (JIS H4160:1994 A8021H-O (thickness: 35 μm)) was prepared as a barrier layer. Next, a two-component urethane adhesive (polyol compound and aromatic isocyanate compound) was applied to one surface of the aluminum alloy foil to form an adhesive layer (3 μm thick) on the barrier layer. Next, after laminating the adhesive layer on the barrier layer and the substrate layer by a dry lamination method, an aging treatment was performed to prepare a laminate of substrate layer/adhesive layer/barrier layer. Both surfaces of the aluminum alloy foil were chemically treated in the same manner as in Example 5. Next, on the barrier layer of each laminate obtained above, maleic anhydride-modified polypropylene as an adhesive layer (20 μm thick) and random polypropylene as a heat-fusible resin layer (15 μm thick). was co-extruded to laminate the adhesive layer/heat-fusible resin layer on the barrier layer. Next, a surface coating layer is formed by coating the surface of the base material layer of the obtained laminate with the same two-liquid curing type resin as in Example 1 so as to have a thickness of 3 μm. Thus, a battery packaging material was obtained in which /base layer/adhesive layer/barrier layer/adhesive layer/heat-fusible resin layer were laminated in this order.

Comparative example 1
An oriented nylon film (thickness: 12 μm) was prepared as a substrate layer, and an aluminum alloy foil (JIS H4160:1994 A8021H-O (thickness: 25 μm)) was prepared as a barrier layer. Next, a two-component urethane adhesive (polyol compound and aromatic isocyanate compound) was applied to one surface of the aluminum alloy foil to form an adhesive layer (3 μm thick) on the barrier layer. Next, after laminating the adhesive layer on the barrier layer and the substrate layer by a dry lamination method, an aging treatment was performed to prepare a laminate of substrate layer/adhesive layer/barrier layer. Both surfaces of the aluminum alloy foil were chemically treated in the same manner as in Example 5. Next, on the barrier layer of each laminate obtained above, maleic anhydride-modified polypropylene as an adhesive layer (thickness 14 μm) and random polypropylene as a heat-fusible resin layer (thickness 10 μm). was co-extruded to laminate the adhesive layer/heat-fusible resin layer on the barrier layer. Next, a surface coating layer is formed by coating the surface of the base material layer of the obtained laminate with the same two-liquid curing type resin as in Example 1 so as to have a thickness of 3 μm. Thus, a battery packaging material was obtained in which /base layer/adhesive layer/barrier layer/adhesive layer/heat-fusible resin layer were laminated in this order.

Comparative example 2
An oriented nylon film (thickness: 15 μm) was prepared as a substrate layer, and an aluminum alloy foil (JIS H4160:1994 A8021H-O (thickness: 20 μm)) was prepared as a barrier layer. Next, a two-component urethane adhesive (polyol compound and aromatic isocyanate compound) was applied to one surface of the aluminum alloy foil to form an adhesive layer (3 μm thick) on the barrier layer. Next, after laminating the adhesive layer on the barrier layer and the substrate layer by a dry lamination method, an aging treatment was performed to prepare a laminate of substrate layer/adhesive layer/barrier layer. Both surfaces of the aluminum alloy foil were chemically treated in the same manner as in Example 5. Next, on the barrier layer of each laminate obtained above, maleic anhydride-modified polypropylene as an adhesive layer (thickness 14 μm) and random polypropylene as a heat-fusible resin layer (thickness 10 μm). By co-extrusion, the adhesive layer/heat-fusible resin layer is laminated on the barrier layer, and the base layer/adhesive layer/barrier layer/adhesive layer/heat-fusible resin layer are laminated in order. Thus, a battery packaging material was obtained.

Comparative example 3
An oriented nylon film (thickness: 12 μm) was prepared as a substrate layer, and an aluminum alloy foil (JIS H4160:1994 A8021H-O (thickness: 20 μm)) was prepared as a barrier layer. Next, a two-component urethane adhesive (polyol compound and aromatic isocyanate compound) was applied to one surface of the aluminum alloy foil to form an adhesive layer (3 μm thick) on the barrier layer. Next, after laminating the adhesive layer on the barrier layer and the substrate layer by a dry lamination method, an aging treatment was performed to prepare a laminate of substrate layer/adhesive layer/barrier layer. Both surfaces of the aluminum alloy foil were chemically treated in the same manner as in Example 5. Next, on the barrier layer of each laminate obtained above, maleic anhydride-modified polypropylene as an adhesive layer (thickness 14 μm) and random polypropylene as a heat-fusible resin layer (thickness 10 μm). By co-extrusion, the adhesive layer/heat-fusible resin layer is laminated on the barrier layer, and the base layer/adhesive layer/barrier layer/adhesive layer/heat-fusible resin layer are laminated in order. Thus, a battery packaging material was obtained.

Comparative example 4
An oriented nylon (ONy) film (thickness: 25 μm) was prepared as a substrate 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 compound) was applied to one surface of the clad foil to form an adhesive layer (3 μm thick) on the barrier layer. Next, after laminating the adhesive layer on the barrier layer and the substrate layer by a dry lamination method, an aging treatment was performed to prepare a laminate of substrate layer/adhesive layer/barrier layer. Both surfaces of the clad foil are chemically treated in the same manner as in the first embodiment. Next, a two-liquid type urethane adhesive (polyol compound and aromatic isocyanate compound) is applied onto the barrier layer of each laminate obtained above, and an adhesive layer (thickness: 2 μm) is formed on the barrier layer. formed. Next, after laminating an adhesive layer on the barrier layer and an unstretched polypropylene film (thickness 23 μm) as a heat-fusible resin layer by a dry lamination method, aging treatment is performed to form an adhesive layer on the barrier layer. /Heat-fusible resin layer were laminated to obtain a battery packaging material in which base layer/adhesive layer/barrier layer/adhesive layer/heat-fusible resin layer were laminated in this order.

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

<Measurement of bending stiffness>
Each battery packaging material obtained above is cut into a rectangle with 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. 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 . The bending stiffness of the packaging material for The test sample was fixed to two clamps so that the edge of the test sample with a width of 80 mm was aligned with the axial direction of the clamps. Table 2 shows the measurement results of bending stiffness.

<Measurement of piercing strength>
Each battery packaging material 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 resulting test sample was measured from the substrate layer side by a method conforming to JIS Z1707:1997. Specifically, in a measurement environment of 23 ± 2 ° C. and relative humidity (50 ± 5)%, the test piece is fixed with a table with a diameter of 115 mm having an opening of 15 mm in the center and a pressing plate. A semicircular needle with a tip shape radius of 0.5 mm was pierced at a speed of 50±5 mm per minute, and the maximum stress until the needle penetrated was measured. The number of test pieces was 5, and the average value was obtained. Imada's ZTS-500N (force gauge) and MX-500N (measuring stand) were used as devices for measuring the puncture strength. Table 2 shows the measurement results of the puncture strength.

<Measurement of tensile modulus>
Each battery packaging material 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, in accordance with JIS K7127:1999, the tensile modulus of elasticity was calculated by pulling the test sample under conditions of a gauge length of 30 mm and a tensile speed of 50 mm/min in the longitudinal direction of the test sample. Table 2 shows the measurement results of the tensile modulus.

<Measurement of limit molding depth>
Each battery packaging material 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 an environment with a temperature of 24 ° C. and a relative humidity of 50%, using a female mold having a diameter of 30 mm × 50 mm and a male mold corresponding thereto, from a molding depth of 0.5 mm at a pressing pressure of 0.9 MPa Molding was performed by increasing the molding depth in 0.5 mm increments, and the molding depth 0.5 mm shallower than the molding depth at which pinholes were generated in the battery packaging material was defined as the limit molding depth of the sample. In the molding, the male mold was arranged on the heat-fusible resin layer side so that the concave portions were formed on the heat-fusible resin layer side and the convex portions were formed on the substrate layer side. The clearance between the male and female molds was 0.3 mm. In addition, the surface of the female mold has a maximum height roughness (nominal value of Rz) of 3.2 μm, which is specified in Table 2 of JIS B 0659-1: 2002 Annex 1 (Reference) Comparative Surface Roughness Standard Piece is. The surface of the male mold has a maximum height roughness (nominal value of Rz) of 1.6 μm as 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 molding depth.

<Evaluation of tape peelability>
In an environment with a temperature of 24 ° C. and a relative humidity of 50%, using a female mold and a male mold with a pressing pressure of 0.9 MPa, each battery packaging material obtained above was molded to obtain the following battery sizes 1 and 2. A recess was formed. In the molding, the male mold was arranged on the heat-fusible resin layer side, and the molding part was provided so that the concave part was formed on the heat-fusible resin layer side and the convex part was formed on the substrate layer side. The clearance between the male and female molds was 0.3 mm. In addition, the surface of the female mold has a maximum height roughness (nominal value of Rz) of 3.2 μm, which is specified in Table 2 of JIS B 0659-1: 2002 Annex 1 (Reference) Comparative Surface Roughness Standard Piece is. The surface of the male mold has a maximum height roughness (nominal value of Rz) of 1.6 μm as specified in Table 2 of JIS B 0659-1: 2002 Annex 1 (reference) Comparative surface roughness standard piece .
Battery size 1: recess width 30 mm, length 90 mm, molding depth 3 mm
Battery size 2: recess width 94 mm, length 128 mm, molding depth 3 mm
In Example 4, the molding depth for battery size 1 and battery size 2 was 2 mm, and in Comparative Example 4, the molding depth for battery size 1 and battery size 2 was 1.5 mm.

Next, as shown in the schematic diagram 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 concave portion of battery size 1, and an acrylic plate 20 of 91 mm wide and 91 mm wide is inserted into the concave portion of battery size 2. An acrylic plate 20 having a length of 125 mm and a height (corresponding to the molding depth direction) of 3 mm was inserted. The inserted acrylic plate 20 was fixed using double-faced tape NO751B manufactured by Teraoka Seisakusho Co., Ltd. so as to adhere to the bottom of the recess of the battery packaging material. Next, double-faced tape 30 (3M #610, thickness 120 μm) and aluminum alloy foil 40 (35 μm) were applied as masking tape to the surface 10a of the convex portion of the molded portion of the battery packaging material. ), and a rubber roller of 200 g was reciprocated once over the aluminum alloy foil 40 to attach the double-sided tape 30 to the surface 10a 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 molded portion is pinched with fingers, and the double-sided tape 30 is pulled in the direction of 180° (the direction of the arrow in FIG. 5) together with the aluminum alloy foil. It peeled off from the surface 10a of the part. Next, the surface of the molded portion 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 portion did not follow the tape, wrinkles were not formed on the surface, and the tape was properly peeled off from the surface of the battery packaging material.
C: The molded part follows the tape, and wrinkles are formed on the surface.

REFERENCE SIGNS LIST 1 Base 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 side of molded part of battery packaging material Surface 20... Acrylic plate 30... Double-sided tape 40... Aluminum alloy foil

Claims (8)

Consists of a laminate comprising at least a substrate layer, a barrier layer, and a heat-fusible resin layer in this order,
The barrier layer is made of stainless steel foil,
The laminate has a thickness of 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 battery packaging material, 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. 2. The battery packaging material according to claim 1 , further comprising a surface coating layer containing an additive on the surface of the base material layer opposite to the barrier layer. 3. The battery packaging material according to claim 1, wherein the base material layer has a thickness of 25 [mu]m or less. Any one of claims 1 to 3 , wherein the laminate has a piercing strength of 5 N or more and 55 N or less when the laminate is pierced from the base layer side, measured by a method conforming to the provisions of JIS Z1707:1997. 1. The battery packaging material according to item 1 . Any one of claims 1 to 4 , wherein the tensile modulus of elasticity in the direction perpendicular to the lamination direction of the laminate is 3.0 GPa or more and 10.0 GPa or less, measured by a method conforming to the provisions of JIS K7127:1999. 1. The battery packaging material according to item 1 . The battery packaging material according to any one of claims 1 to 5 , wherein the heat-sealable resin layer contains polyolefin. The battery packaging material according to any one of claims 1 to 6 , wherein the base material layer contains at least one of a polyester resin and a polyamide resin. A battery, wherein a battery element comprising at least a positive electrode, a negative electrode, and an electrolyte is housed in a package formed of the battery packaging material according to any one of claims 1 to 7 .

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