WO2016052293A1

WO2016052293A1 - Adhesive film for metal terminal

Info

Publication number: WO2016052293A1
Application number: PCT/JP2015/076901
Authority: WO
Inventors: 洋平橋本; 山下　力也
Original assignee: 大日本印刷株式会社
Priority date: 2014-09-30
Filing date: 2015-09-24
Publication date: 2016-04-07
Also published as: JP6673208B2; JPWO2016052293A1

Abstract

Provided is an adhesive film for a metal terminal, the adhesive film being excellent in electrolyte resistance and being able to effectively suppress short circuits between a metal terminal and a metal foil layer of a packaging material. The adhesive film for a metal terminal is to be interposed between a metal terminal that is electrically connected to an electrode of a battery element and a packaging material that seals the battery element. The adhesive film for a metal terminal comprises an acid reactive resin layer that includes an acid-modified polyolefin and an acid curable resin.

Description

Adhesive film for metal terminals

The present invention uses an adhesive film for a metal terminal, which has excellent electrolytic solution resistance, and can effectively suppress a short circuit between the metal terminal and the metal foil layer of the packaging material, and the metal terminal adhesive film. It relates to batteries.

Conventionally, various types of batteries have been developed, but packaging materials are indispensable members for sealing battery elements such as electrodes and electrolytes in all batteries. Conventionally, metal packaging materials have been widely used as battery packaging, but 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. At the same time, there is a demand for reduction in thickness and weight. However, conventionally used metal packaging materials have the disadvantages that it is difficult to follow the diversification of shapes and that there is a limit to weight reduction.

Therefore, in recent years, as a packaging material that can be easily processed into various shapes and can be made thinner and lighter, a film-like laminate in which a base layer / adhesive layer / barrier layer / sealant layer are sequentially laminated has been proposed. (For example, refer to Patent Document 1). When such a film-shaped packaging material is used, the battery is made of the packaging material by heat-sealing the peripheral edge of the packaging material by heat sealing with the sealant layers positioned in the innermost layers of the packaging material facing each other. The element is sealed. A metal terminal protrudes from the heat seal portion of the packaging material, and the battery element sealed by the packaging material is electrically connected to the outside by a metal terminal electrically connected to the electrode of the battery element. That is, in the heat seal portion of the packaging material, the metal terminal is formed so as to protrude to the outside of the packaging material while being sandwiched between the sealant layers. Since the metal terminal and the sealant layer are formed of different materials, the sealing performance of the battery element tends to be low at the interface between the metal terminal and the sealant layer. For this reason, a technique is known in which an adhesive film is disposed at the interface portion between the metal terminal and the sealant layer to suppress a decrease in hermeticity at the interface portion between the metal terminal and the sealant layer.

For example, Patent Document 2 discloses an adhesive film for sealing a lithium battery metal terminal part in which an acid-modified polyolefin layer is formed on both sides of a biaxially stretched polyethylene naphthalate film via an adhesion promoter layer made of an isocyanate component. It is disclosed.

JP 2001-202927 A Patent No. 4440573

In the adhesive film disclosed in Patent Document 2, a biaxially stretched polyethylene naphthalate film having a high water vapor barrier property and high mechanical strength functions as a substrate, and a polyolefin is formed on both sides of the biaxially stretched polyethylene naphthalate film. Since the layer is formed, the short circuit between the metal foil layer of the packaging material and the metal terminal can be suppressed, and the adhesion between the metal terminal and the sealant layer can be improved.

On the other hand, in the adhesive film disclosed in Patent Document 2, a polyolefin layer is formed on both sides of a polyethylene naphthalate film serving as a substrate via an isocyanate component. That is, the adhesive film disclosed in Patent Document 2 has a structure in which different types of materials having significantly different physical properties are bonded together. For this reason, peeling arises between each layer which comprises an adhesive film, and electrolyte solution resistance may fall. Furthermore, since the polyethylene naphthalate film used for increasing the water vapor barrier property and mechanical strength is expensive, development of an adhesive film using a cheaper material is also required.
Under such circumstances, the present invention is excellent in electrolytic solution resistance without using a polyethylene naphthalate film, and can effectively suppress a short circuit between the metal terminal and the metal foil layer of the packaging material. The main purpose is to provide an adhesive film.

The inventors of the present invention have intensively studied to solve the above problems. As a result, in the adhesive film for metal terminal interposed between the metal terminal electrically connected to the electrode of the battery element and the packaging material for sealing the battery element, the adhesive film for metal terminal is The present inventors have found that by having an acid-reactive resin layer containing an acid-modified polyolefin and an acid-curable resin, it has excellent electrolytic solution resistance and can effectively suppress a short circuit between the metal terminal and the metal foil layer of the packaging material. The present invention has been completed by further studies based on such knowledge.

That is, this invention provides the invention of the aspect hung up below.
Item 1. An adhesive film for metal terminals interposed between a metal terminal electrically connected to the electrode of the battery element and a packaging material for sealing the battery element,
The said adhesive film for metal terminals is an adhesive film for metal terminals which has an acid reaction resin layer containing acid-modified polyolefin and acid curable resin.
Item 2. Item 2. The adhesive film for metal terminals according to Item 1, comprising a polyolefin layer formed of at least one of polyolefin and acid-modified polyolefin on at least one surface of the acid-reactive resin layer.
Item 3. Item 2. The adhesive film for metal terminals according to Item 1, comprising a polyolefin layer formed of an acid-modified polyolefin on at least one surface of the acid-reactive resin layer.
Item 4. Item 4. The adhesive film for metal terminals according to any one of Items 1 to 3, which has a polyolefin layer formed of an acid-modified polyolefin on both surfaces of the acid reaction resin layer.
Item 5. Item 5. The adhesive film for metal terminals according to any one of Items 1 to 4, wherein the acid curable resin is at least one of an acid curable furan resin and an acid curable phenol resin.
Item 6. Item 6. The adhesive film for metal terminals according to any one of Items 1 to 5, wherein the acid-modified polyolefin contained in the acid-reactive resin layer is a polyolefin graft-modified with an unsaturated carboxylic acid or an anhydride thereof.
Item 7. Item 7. The adhesive film for metal terminals according to any one of Items 1 to 6, wherein the thickness is 10 to 200 μm.
Item 8. The packaging material is a laminate having at least a base material layer, an adhesive layer, a metal foil layer, and a sealant layer in this order, and the adhesive film for metal terminals is interposed between the sealant layer and the metal terminals. Item 8. The adhesive film for metal terminals according to any one of Items 1 to 7.
Item 9. A battery element including at least a positive electrode, a negative electrode, and an electrolyte, a packaging material that seals the battery element, and a metal terminal that is electrically connected to each of the positive electrode and the negative electrode and protrudes outside the packaging material A battery comprising:
Item 9. A battery, wherein the metal terminal adhesive film according to any one of Items 1 to 8 is interposed between the metal terminal and the packaging material.

The adhesive film for metal terminals of the present invention is an adhesive film for metal terminals interposed between a metal terminal electrically connected to an electrode of a battery element and a packaging material for sealing the battery element. The metal terminal adhesive film has an acid-reactive resin layer containing an acid-modified polyolefin and an acid-curable resin. When the adhesive film for a metal terminal of the present invention is disposed between the metal terminal of the battery and the packaging material, an acid component (for example, electrolyte and moisture) that permeates the periphery of the metal terminal over time. The hydrogen fluoride produced by the reaction reaches the acid-reactive resin layer of the metal terminal adhesive film, the acid-curable resin contained in the acid-reactive resin layer is cured, and the metal terminal adhesive film Electrolytic solution resistance and mechanical strength are increased. Therefore, the adhesive film for metal terminals of the present invention is excellent in electrolyte solution resistance, and can effectively suppress a short circuit between the metal terminal and the metal foil layer of the packaging material.

The battery of the present invention includes at least a battery element including a positive electrode, a negative electrode, and an electrolyte, a packaging material that seals the battery element, and a positive electrode and a negative electrode that are electrically connected to the outside of the packaging material. A metal terminal protruding from the metal terminal, wherein the adhesive film for metal terminal of the present invention is interposed between the metal terminal and the packaging material. For this reason, in the battery of this invention, it is excellent in electrolyte solution resistance, and the short circuit with a metal terminal and the metal foil layer of a packaging material is suppressed effectively.

It is a schematic plan view of the battery of the present invention. FIG. 2 is a schematic cross-sectional view taken along line A-A ′ of FIG. 1. FIG. 2 is a schematic cross-sectional view taken along line B-B ′ of FIG. 1. It is a schematic sectional drawing of the adhesive film for metal terminals of this invention. It is a schematic sectional drawing of the adhesive film for metal terminals of this invention. It is a schematic sectional drawing of the adhesive film for metal terminals of this invention. It is a schematic sectional drawing of the packaging material used for the battery of this invention.

The adhesive film for metal terminals of the present invention is an adhesive film for metal terminals interposed between a metal terminal electrically connected to an electrode of a battery element and a packaging material for sealing the battery element. And an acid-reactive resin layer containing an acid-modified polyolefin and an acid-curable resin. The battery of the present invention includes at least a battery element including a positive electrode, a negative electrode, and an electrolyte, a packaging material that seals the battery element, and each of the positive electrode and the negative electrode, and the package A battery comprising a metal terminal protruding outside the material, wherein the metal terminal adhesive film of the present invention is interposed between the metal terminal and the packaging material. Hereinafter, the adhesive film for metal terminals of the present invention and the battery of the present invention using the same will be described in detail.

1. Adhesive film for metal terminals The adhesive film for metal terminals of the present invention is interposed between a metal terminal electrically connected to an electrode of a battery element and a packaging material for sealing the battery element. is there. Specifically, as shown in FIGS. 1 to 3, for example, the adhesive film 1 for metal terminals of the present invention includes a metal terminal 2 electrically connected to an electrode of the battery element 4 and a battery element 4. It is interposed between the packaging material 3 to be sealed. The metal terminal 2 protrudes outside the packaging material 3, and is sandwiched between the packaging material 3 via the metal terminal adhesive film 1 at the peripheral edge 3 a of the heat-sealed packaging material 3. In the present invention, the heat when heat-sealing the packaging material is usually in the range of about 160 to 190 ° C., and the pressure is usually in the range of about 1.0 to 2.0 MPa.

The adhesive film 1 for metal terminals of the present invention is provided in order to improve the adhesion between the metal terminals 2 and the packaging material 3. By improving the adhesion between the metal terminal 2 and the packaging material 3, the sealing performance of the battery element 4 is improved. As described above, when the battery element 4 is heat sealed, the battery element is sealed so that the metal terminal 2 electrically connected to the electrode of the battery element 4 protrudes outside the packaging material 3. . At this time, the metal terminal 2 formed of metal and the sealant layer 34 (layer formed of the heat-fusible resin) located in the innermost layer of the packaging material 3 are formed of different materials, and thus When no adhesive film is used, the sealing performance of the battery element tends to be low at the interface between the metal terminal 2 and the sealant layer 34.

The metal terminal adhesive film 1 of the present invention has an acid-reactive resin layer 11 containing an acid-modified polyolefin and an acid-curable resin. When the metal terminal adhesive film 1 of the present invention is disposed between the metal terminal 2 and the packaging material 3 of the battery, the acid component that has permeated with the passage of time (for example, the electrolyte of the battery element 4 and the outside) The hydrogen fluoride generated by the reaction of moisture intruded from the metal reaches the acid-reactive resin layer 11 of the metal terminal adhesive film 1, and the acid-curable resin contained in the acid-reactive resin layer 11 is cured. In addition, the electrolytic solution resistance and mechanical strength of the metal terminal adhesive film 1 are improved. Therefore, the adhesive film 1 for a metal terminal of the present invention is excellent in electrolytic solution resistance, and can effectively suppress a short circuit between the metal terminal 2 and the metal foil layer 33 of the packaging material 3.

The adhesive film 1 for a metal terminal only needs to have an acid reaction resin layer 11 containing an acid-modified polyolefin and an acid curable resin. For example, the metal terminal adhesive film 1 may be formed of only the acid reaction resin layer 11 or a metal terminal. 2 or a polyolefin layer formed on at least one surface (main surface) of the acid-reactive resin layer 11 with at least one of polyolefin and acid-modified polyolefin for the purpose of further improving the adhesion to the 2 or sealant layer 34. May be formed. Since the acid-modified polyolefin has particularly high adhesion to the metal material, the metal terminal adhesive film 1 of the present invention is formed on at least one surface (main surface) of the acid-reactive resin layer 11 with the acid-modified polyolefin. It is preferable to have a polyolefin layer. Furthermore, it is particularly preferable to have a polyolefin layer formed of acid-modified polyolefin on both surfaces (both main surfaces) of the acid reaction resin layer 11. Hereinafter, the polyolefin layer formed from the acid-modified polyolefin is sometimes referred to as an “acid-modified polyolefin layer”.

Specific examples of the layer structure of the adhesive film for metal terminals of the present invention include a structure composed of an acid-reactive resin layer; a structure in which an acid-modified polyolefin layer / an acid-reactive resin layer are sequentially laminated; a polyolefin layer / an acid-reactive resin layer In which the acid-modified polyolefin layer / acid reaction resin layer / acid-modified polyolefin layer are sequentially laminated; acid-modified polyolefin layer / acid reaction resin layer / polyolefin layer in order; polyolefin layer / The structure by which the acid reaction resin layer / polyolefin layer was laminated | stacked in order is mentioned.

As a specific example of the layer structure of the adhesive film for metal terminals of the present invention, FIG. 4 shows a schematic cross-sectional view of the adhesive film 1 for metal terminals formed only by the acid reaction resin layer 11. In FIG. 5, the typical sectional drawing of the adhesive film 1 for metal terminals in which the polyolefin layer 12 / acid reaction resin layer 11 was laminated | stacked in order is shown. FIG. 6 shows a schematic cross-sectional view of the metal terminal adhesive film 1 in which the polyolefin layer 12 / acid reaction resin layer 11 / polyolefin layer 13 are laminated in order.

[Acid reaction resin layer 11]
The acid reaction resin layer 11 is formed of an acid-modified polyolefin and an acid curable resin. The acid curable resin is a resin having a property of being polymerized and cured in the presence of an acid. Although it does not restrict | limit especially about the kind of acid curable resin used by this invention, For example, an acid curable furan resin, an acid curable phenol resin, etc. are mentioned.

Specific examples of the acid curable furan resin include furfuryl alcohol, condensate of furfuryl alcohol, condensate of furfuryl alcohol and aldehydes, condensate of furfuryl alcohol and urea, furfuryl alcohol and phenols. And a condensate of furfuryl alcohol, melamine, and aldehydes, a condensate of furfuryl alcohol, urea, and aldehydes. These acid-curable furan resins may be used alone or in combination of two or more.

Examples of the aldehydes condensed with furfuryl alcohol include formaldehyde, acetaldehyde, glyoxal, furfural, terephthalaldehyde, and the like. These aldehydes may be used individually by 1 type, and may be used in combination of 2 or more type.

Examples of the phenols condensed with furfuryl alcohol include phenol, cresol, resorcin, bisphenol A, bisphenol C, bisphenol E, bisphenol F, and the like. These phenols may be used individually by 1 type, and may be used in combination of 2 or more type.

The acid curable phenolic resin may be either a novolak type or a resol type. An acid curable phenol resin may be used individually by 1 type, and may be used in combination of 2 or more type.

These acid curable resins may be used alone or in combination of two or more. Among these acid curable resins, from the viewpoint of providing more excellent electrolytic solution resistance, preferably a thermosetting furan resin, more preferably a condensate of furfuryl alcohol and urea, furfuryl alcohol and urea. And urea-modified furan resins such as condensates of aldehydes.

In the acid reaction resin layer 11, the acid curable resin may be in a partially cured state as long as at least a part thereof is contained in an uncured state. Thus, when at least a part of the acid curable resin exists in an uncured state, it can be cured when brought into contact with the acid generated in the electrolytic solution, and can have excellent electrolytic solution resistance. Moreover, since the mechanical strength of the acid reaction resin layer 11 is raised after hardening, it can suppress effectively that the metal terminal 2 and the metal foil layer of the packaging material 3 contact and short-circuit.

In order for the acid-reactive resin layer 11 to partially exist in a cured state, the resin composition for forming the acid-reactive resin layer 11 is applied to a predetermined portion and then heat-treated. . The conditions for the heat treatment may be appropriately set according to the type of acid curable resin to be used, the degree of curing, etc., for example, about 120 to 250 ° C., preferably about 150 to 200 ° C., for example 0.1 About 60 seconds, preferably about 1 to 30 seconds.

Although it does not restrict | limit especially as a ratio of the acid curable resin in the acid reaction resin layer 11, Preferably it is 0.1 mass% or more, More preferably, it is 1 mass% or more, More preferably, 2 mass% or more is mentioned. By satisfying such a ratio, it is possible to provide more excellent electrolytic solution resistance and short circuit prevention performance. In addition, as an upper limit of the ratio of the acid curable resin in the acid reaction resin layer 11, it is about 35 mass% normally.

In the acid reaction resin layer 11, the acid curable resin is preferably contained uniformly.

The acid-modified polyolefin contained in the acid-reactive resin layer 11 is not particularly limited, but preferably includes a polyolefin graft-modified with an unsaturated carboxylic acid or its anhydride. Specific examples of polyolefins that are graft-modified with unsaturated carboxylic acids or anhydrides thereof include polyethylenes such as low density polyethylene, medium density polyethylene, high density polyethylene, and linear low density polyethylene; homopolypropylene, polypropylene block copolymers (For example, block copolymer of propylene and ethylene), polypropylene or random copolymer of polypropylene (for example, random copolymer of propylene and ethylene) or the like; and terpolymer of ethylene-butene-propylene; Among these polyolefins, polyethylene and polypropylene are preferable. The polyolefin may be a cyclic polyolefin. The cyclic polyolefin is a copolymer of an olefin and a cyclic monomer. Examples of the olefin that is a constituent monomer of the cyclic polyolefin include ethylene, propylene, 4-methyl-1-pentene, styrene, butadiene, and isoprene. . Examples of the cyclic monomer that is a constituent monomer of the cyclic polyolefin include cyclic alkenes such as norbornene; specifically, cyclic dienes such as cyclopentadiene, dicyclopentadiene, cyclohexadiene, and norbornadiene. Among these polyolefins, a cyclic alkene is preferable, and norbornene is more preferable.

Also, examples of the carboxylic acid or anhydride thereof used for modifying polyolefin include maleic acid, acrylic acid, itaconic acid, crotonic acid, maleic anhydride, itaconic anhydride and the like. The carboxylic acid-modified cyclic polyolefin obtained by modifying the cyclic polyolefin with a carboxylic acid or an anhydride thereof is obtained by replacing a part of the monomer constituting the cyclic polyolefin with an α, β-unsaturated carboxylic acid or an anhydride thereof. It is a polymer obtained by copolymerization or by block polymerization or graft polymerization of α, β-unsaturated carboxylic acid or its anhydride to cyclic polyolefin.

The acid reaction resin layer 11 may contain the above polyolefin in addition to the acid-modified polyolefin. In addition, each of the acid-modified polyolefin and the polyolefin may be used alone or in combination of two or more.

As described above, it is preferable that at least one surface of the acid-reactive resin layer 11 has polyolefin layers 12 and 13 formed of at least one of polyolefin and acid-modified polyolefin.

[Polyolefin layers 12, 13]
As shown in FIG. 5 or 6, in the metal terminal adhesive film 1 of the present invention, at least one of the polyolefin and the acid-modified polyolefin is provided on at least one side of the acid-reactive resin layer 11 as necessary. It may have

polyolefin layers

12 and 13 formed by. By having the polyolefin layers 12 and 13 on the surface of at least one side of the acid reaction resin layer 11, the adhesion between the metal terminal adhesive film 1 of the present invention and the metal terminal 2 or the packaging material 3 can be further enhanced. it can. In particular, since the acid-modified polyolefin is excellent in adhesion to a metal material, polyolefin layers 12 and 13 (acid-modified polyolefin layer) formed of acid-modified polyolefin are formed on at least one surface of the acid-reactive resin layer 11. 12, 13) is preferably formed. Moreover, from the viewpoint of ensuring high adhesion between the metal terminal adhesive film 1 and the metal terminal 2, whichever surface of the metal terminal adhesive film 1 is in contact with the metal terminal 2, the acid-reactive resin. It is preferable to have acid-modified polyolefin layers 12 and 13 on both sides of the layer 11.

Specific examples of the polyolefin and acid-modified polyolefin that form the polyolefin layers 12 and 13 are the same as the polyolefin and acid-modified polyolefin exemplified above, respectively. Each of the polyolefin and the acid-modified polyolefin may be used alone or in combination of two or more.

The polyolefin layers 12 and 13 preferably contain substantially no acid curable resin.

The polyolefin layers 12 and 13 may contain a filler as necessary. Since the polyolefin layers 12 and 13 contain a filler, the filler functions as a spacer, so that the short circuit between the metal terminal 2 and the metal foil layer 33 of the packaging material 3 is more effectively suppressed. It becomes possible to do. The particle size of the filler is in the range of about 0.1 to 35 μm, preferably about 5.0 to 30 μm, more preferably about 10 to 25 μm. The content of the filler is about 5 to 30 parts by mass, more preferably about 10 to 20 parts by mass with respect to 100 parts by mass of the resin component forming the polyolefin layers 12 and 13.

As the filler, either inorganic or organic can be used. Examples of inorganic fillers include carbon (carbon, graphite), silica, aluminum oxide, barium titanate, iron oxide, silicon carbide, zirconium oxide, zirconium silicate, magnesium oxide, titanium oxide, calcium aluminate, and calcium hydroxide. , Aluminum hydroxide, magnesium hydroxide, calcium carbonate and the like. Examples of organic fillers include fluorine resin, phenol resin, urea resin, epoxy resin, acrylic resin, benzoguanamine / formaldehyde condensate, melamine / formaldehyde condensate, polymethyl methacrylate cross-linked product, polyethylene cross-linked product, etc. Can be mentioned. Aluminum oxide, silica, fluororesin, acrylic resin, and benzoguanamine / formaldehyde condensate are preferable from the viewpoint of shape stability, rigidity, and content resistance, and spherical aluminum oxide and silica are more preferable among them. As a method of mixing the filler into the resin component forming the polyolefin layers 12 and 13, a method of melt-blending both with a Banbury mixer or the like in advance and making a master batch into a predetermined mixing ratio, directly with the resin component A mixing method or the like can be employed.

Further, the polyolefin layers 12 and 13 may contain a pigment as necessary. As the pigment, various inorganic pigments can be used. As a specific example of the pigment, carbon (carbon, graphite) exemplified for the filler can be preferably exemplified. Carbon (carbon, graphite) is a material generally used in the battery, and there is no risk of elution from the electrolyte. In addition, a sufficient coloring effect can be obtained with an addition amount that has a large coloring effect and does not impair adhesiveness, and the apparent melt viscosity of the added resin can be increased without melting by heat. Furthermore, it is possible to prevent the pressure portion from becoming thin during thermal bonding (sealing), and to prevent a decrease in seal strength.

When the pigment is added to the polyolefin layers 12 and 13, for example, when carbon black having a particle size of about 0.03 μm is used, the addition amount is 100 parts by mass of the resin component forming the polyolefin layers 12 and 13. About 0.05 to 0.3 parts by mass, preferably about 0.1 to 0.2 parts by mass. By adding a pigment to the polyolefin layers 12 and 13, the presence or absence of the metal terminal adhesive film 1 can be detected by a sensor, or can be visually inspected. In addition, when adding a filler and a pigment to the polyolefin layers 12 and 13, you may add a filler and a pigment to the same polyolefin layers 12 and 13, but the heat-fusibility of the adhesive film 1 for metal terminals. From the viewpoint of not inhibiting the filler, the filler and the pigment are preferably added to the

separate polyolefin layers

12 and 13.

About the thickness of the acid reaction resin layer 11, it can select suitably according to the layer structure of the adhesive film 1 for metal terminals, etc. FIG. For example, when the metal terminal adhesive film 1 is formed of only the acid reaction resin layer 11, the thickness of the acid reaction resin layer 11 (that is, the metal terminal adhesive film 1) is, for example, 0.01 to 15 μm. About 0.1 to 10 μm, more preferably about 1 to 5 μm. For example, when the metal terminal adhesive film 1 is formed of the acid reaction resin layer 11 and the polyolefin layer 12, the thickness of the acid reaction resin layer 11 is, for example, about 0.1 to 150 μm, preferably 1 to 1 μm. The thickness is about 100 μm, more preferably about 20 to 50 μm. Furthermore, when the metal terminal adhesive film 1 is formed of the polyolefin layer 12, the acid reaction resin layer 11, and the polyolefin layer 13, the thickness of the acid reaction resin layer 11 is, for example, about 0.1 to 150 μm, Preferably about 1 to 100 μm, more preferably about 20 to 50 μm.

The thickness of each of the polyolefin layers 12 and 13 can be appropriately selected according to the layer structure of the metal terminal adhesive film 1, and is, for example, about 0.1 to 100 μm, preferably about 1 to 80 μm, more preferably. An example is about 10 to 50 μm.

The thickness of the metal terminal adhesive film 1 is, for example, about 10 to 200 μm, preferably about 20 to 150 μm, more preferably about 50 to 100 μm.

The method for interposing the metal terminal adhesive film 1 between the metal terminal 2 and the packaging material 3 is not particularly limited. For example, the metal terminal 2 is sandwiched between the packaging materials 3 as shown in FIGS. The metal terminal adhesive film 1 may be wound around the metal terminal 2 in the portion to be formed. Although not shown, the metal terminal adhesive film 1 is disposed on both surfaces of the metal terminal 2 so that the metal terminal adhesive film 1 crosses the two metal terminals 2 at the portion where the metal terminal 2 is sandwiched by the packaging material 3. Also good.

The metal terminal adhesive film 1 can be manufactured, for example, as follows. When the metal terminal adhesive film 1 is formed only by the acid-reactive resin layer 11, a gravure coating method, a roll coating method, a bar coating method, or the like is applied to a resin composition containing an acid-modified polyolefin and an acid-curable resin. The film is applied to a predetermined place by the method described above. When the metal terminal adhesive film 1 is provided with the polyolefin layers 12 and 13 on at least one surface of the acid reaction resin layer 11, the acid reaction resin layer 11 and the polyolefin layers 12 and 13 are formed, respectively. The above resin components may be used for lamination by a known method such as a dry lamination method, a coextrusion lamination method, a thermal lamination method, or a sand lamination method. Further, in order to cure a part of the acid curable resin contained in the acid reaction resin layer 11, for example, a heat treatment is performed after a resin composition containing an acid-modified polyolefin and an acid curable resin is applied to a predetermined portion. Good. The conditions for the heat treatment are as described in the column of [Acid reaction resin layer 11].

[Metal terminal 2]
The adhesive film 1 for metal terminals of the present invention is used by being interposed between the metal terminals 2 and the packaging material 2. The metal terminal 2 (tab) is a member that is electrically connected to the electrode (positive electrode or negative electrode) of the battery element 4 and is made of a metal material. The metal material constituting the metal terminal 2 is not particularly limited, and examples thereof include aluminum, nickel, and copper. For example, the metal terminal 2 connected to the positive electrode of a lithium ion battery is usually made of aluminum or the like. Moreover, the metal terminal connected to the negative electrode of a lithium ion battery is normally comprised with copper, nickel, etc.

The surface of the metal terminal 2 is preferably subjected to chemical conversion treatment from the viewpoint of improving the resistance to electrolytic solution. For example, when the metal terminal 2 is made of aluminum, specific examples of the chemical conversion treatment include known methods for forming an acid-resistant film such as phosphate, chromate, fluoride, and triazine thiol compound. . Among the methods for forming an acid-resistant film, a phosphoric acid chromate treatment using a phenol resin, a chromium fluoride (3) compound, and a phosphoric acid is preferably used.

The size of the metal terminal 2 may be appropriately set according to the size of the battery used. The thickness of the metal terminal 2 is preferably about 50 to 1000 μm, more preferably about 70 to 800 μm. Further, the length of the metal terminal 2 is preferably about 1 to 200 mm, more preferably about 3 to 150 mm. Further, the width of the metal terminal 2 is preferably about 1 to 200 mm, more preferably about 3 to 150 mm.

[Packaging material 3]
Examples of the packaging material 3 include those having a laminated structure including at least a base material layer 31, an adhesive layer 32, a metal foil layer 33, and a sealant layer 34 in this order. FIG. 7 shows an example in which a base material layer 31, an adhesive layer 32, a metal foil layer 33, and a sealant layer 34 are laminated in this order as an example of a cross-sectional structure of the packaging material 3. In the packaging material 3, the base material layer 31 is the outermost layer and the sealant layer 34 is the innermost layer. At the time of assembling the battery, the sealant layers 34 located on the periphery of the battery element 4 are brought into contact with each other and thermally welded, whereby the battery element 4 is sealed and the battery element 4 is sealed. 1 to 3 show a battery 10 using an embossed type packaging material 3 formed by embossing or the like, the packaging material 3 may be a pouch type that is not molded. Good. The pouch type includes a three-side seal, a four-side seal, and a pillow type, but any type may be used.

(Base material layer 31)
In the packaging material 3, the base material layer 31 is a layer that functions as a base material of the packaging material, and is a layer that forms the outermost layer.

The material for forming the base material layer 31 is not particularly limited as long as it has insulating properties. Examples of the material for forming the base material layer 31 include polyester, polyamide, epoxy, acrylic, fluorine resin, polyurethane, silicon resin, phenol, polyetherimide, polyimide, and mixtures and copolymers thereof.

Specific examples of the polyester include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, polycarbonate, copolymerized polyester mainly composed of ethylene terephthalate, and repeating units of butylene terephthalate. Copolyester etc. mainly composed of The copolymer polyester mainly composed of ethylene terephthalate is a copolymer polyester that polymerizes with ethylene isophthalate mainly composed of ethylene terephthalate (hereinafter, polyethylene (terephthalate / isophthalate)). Abbreviated), polyethylene (terephthalate / isophthalate), polyethylene (terephthalate / adipate), polyethylene (terephthalate / sodium sulfoisophthalate), polyethylene (terephthalate / sodium isophthalate), polyethylene (terephthalate / phenyl-dicarboxylate) And polyethylene (terephthalate / decanedicarboxylate). In addition, as a copolymer polyester mainly composed of butylene terephthalate as a repeating unit, specifically, a copolymer polyester that polymerizes with butylene isophthalate having butylene terephthalate as a repeating unit (hereinafter referred to as polybutylene (terephthalate / isophthalate)). For example), polybutylene (terephthalate / adipate), polybutylene (terephthalate / sebacate), polybutylene (terephthalate / decanedicarboxylate), polybutylene naphthalate and the like. These polyesters may be used individually by 1 type, and may be used in combination of 2 or more type. Polyester has the advantage that it is excellent in resistance to electrolytic solution and hardly causes whitening or the like due to adhesion of the electrolytic solution, and is suitably used as a material for forming the base material layer 31.

Specific examples of the polyamides include aliphatic polyamides such as nylon 6, nylon 66, nylon 610, nylon 12, nylon 46, and a copolymer of nylon 6 and nylon 6,6; terephthalic acid and / or Or a hexamethylenediamine-isophthalic acid-terephthalic acid copolymer polyamide, polymer, such as nylon 6I, nylon 6T, nylon 6IT, nylon 6I6T (I represents isophthalic acid, T represents terephthalic acid) containing structural units derived from isophthalic acid Polyamides containing aromatics such as taxylylene adipamide (MXD6); Alicyclic polyamides such as polyaminomethylcyclohexyl adipamide (PACM6); and isocyanate components such as lactam components and 4,4′-diphenylmethane-diisocyanate Copolymerized polyamide Copolymerized polyamide and polyester and a copolymer of a polyalkylene ether glycol polyester amide copolymer and polyether ester amide copolymers; copolymers thereof, and the like. These polyamides may be used individually by 1 type, and may be used in combination of 2 or more type. The stretched polyamide film has excellent stretchability, can prevent whitening due to resin cracking of the base material layer 31 during molding, and is suitably used as a material for forming the base material layer 31.

The base material layer 31 may be formed of a uniaxial or biaxially stretched resin film, or may be formed of an unstretched resin film. Among them, a uniaxially or biaxially stretched resin film, particularly a biaxially stretched resin film has improved heat resistance due to orientation crystallization, and thus is preferably used as the base material layer 31.

Among these, the resin film forming the base layer 31 is preferably nylon or polyester, more preferably biaxially stretched nylon, biaxially stretched polyester, and particularly preferably biaxially stretched polyester.

The base material layer 31 can be laminated with resin films of different materials in order to improve pinhole resistance and insulation when used as a battery package. Specific examples include a multilayer structure in which a polyester film and a nylon film are laminated, and a multilayer structure in which a biaxially stretched polyester and a biaxially stretched nylon are laminated. When making the base material layer 31 into a multilayer structure, each resin film may be adhere | attached through an adhesive agent, and may be laminated | stacked directly without an adhesive agent. In the case of bonding without using an adhesive, for example, a method of bonding in a hot melt state such as a co-extrusion method, a sand lamination method, or a thermal laminating method can be mentioned.

Further, the base material layer 31 may be reduced in friction in order to improve moldability. When reducing the friction of the base material layer 31, the friction coefficient of the surface is not particularly limited, but for example, 1.0 or less can be mentioned. In order to reduce the friction of the base material layer 31, for example, mat treatment, formation of a thin film layer of a slip agent, a combination thereof, and the like can be given.

The thickness of the base material layer 31 is, for example, about 10 to 50 μm, preferably about 15 to 30 μm.

(Adhesive layer 32)
In the packaging material 3, the adhesive layer 32 is a layer disposed on the base material layer 31 in order to impart adhesion to the base material layer 31. That is, the adhesive layer 32 is provided between the base material layer 31 and the metal foil layer 33.

The adhesive layer 32 is formed of an adhesive capable of bonding the base material layer 31 and the metal foil layer 33. The adhesive used for forming the adhesive layer 32 may be a two-component curable adhesive or a one-component curable adhesive. Also, the adhesive mechanism of the adhesive used for forming the adhesive layer 32 is not particularly limited, and may be any of a chemical reaction type, a solvent volatilization type, a heat melting type, a hot pressure type, and the like.

Specific examples of the resin component of the adhesive that can be used to form the adhesive layer 32 include polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, polycarbonate, and copolyester. Resin; Polyether adhesive; Polyurethane adhesive; Epoxy resin; Phenol resin resin; Polyamide resin such as nylon 6, nylon 66, nylon 12, copolymer polyamide; polyolefin, acid-modified polyolefin, metal-modified polyolefin, etc. Polyolefin resin; polyvinyl acetate resin; cellulose adhesive; (meth) acrylic resin; polyimide resin; amino resin such as urea resin and melamine resin; chloroprene rubber, nitrile rubber, Silicone resin; - Len rubber such as butadiene rubber fluorinated ethylene propylene copolymer, and the like. These adhesive components may be used individually by 1 type, and may be used in combination of 2 or more type. The combination mode of two or more kinds of adhesive components is not particularly limited. For example, as the adhesive component, a mixed resin of polyamide and acid-modified polyolefin, a mixed resin of polyamide and metal-modified polyolefin, polyamide and polyester, Examples thereof include a mixed resin of polyester and acid-modified polyolefin, and a mixed resin of polyester and metal-modified polyolefin. Among these, extensibility, durability under high humidity conditions, anti-hypertensive action, heat deterioration-preventing action at the time of heat sealing, etc. are excellent, and a decrease in lamination strength between the base material layer 31 and the metal foil layer 33 is suppressed. From the viewpoint of effectively suppressing the occurrence of delamination, a polyurethane two-component curable adhesive; polyamide, polyester, or a blended resin of these with a modified polyolefin is preferably used.

Also, the adhesive layer 32 may be multilayered with different adhesive components. When multilayering the adhesive layer 32 with different adhesive components, from the viewpoint of improving the lamination strength between the base material layer 31 and the metal foil layer 33, the adhesive component disposed on the base material layer 31 side is used as the base material layer. It is preferable to select a resin having excellent adhesiveness with 31 and to select an adhesive component having excellent adhesiveness with the metal foil layer 33 as an adhesive component disposed on the metal foil layer 33 side. When the adhesive layer 32 is multilayered with different adhesive components, specifically, the adhesive component disposed on the metal foil layer 33 side is preferably acid-modified polyolefin, metal-modified polyolefin, polyester and acid-modified polyolefin. And mixed resins, resins containing copolymerized polyesters, and the like.

The thickness of the adhesive layer 32 is, for example, about 2 to 50 μm, preferably about 3 to 25 μm.

(Metal foil layer 33)
In the packaging material 3, the metal foil layer 33 is a layer that functions as a barrier layer for preventing the penetration of water vapor, oxygen, light, and the like into the battery, in addition to improving the strength of the packaging material. Specific examples of the metal forming the metal foil layer 33 include metal foils such as aluminum, stainless steel, and titanium. Among these, aluminum is preferably used. In order to prevent wrinkles and pinholes during the production of the packaging material, soft aluminum, for example, annealed aluminum (JIS A8021P-O) or (JIS A8079P-O) is used as the metal foil layer 33 in the present invention. It is preferable.

The thickness of the metal foil layer 33 is preferably about 10 to 200 μm, more preferably about 20 to 100 μm, from the viewpoint of reducing the thickness of the packaging material and preventing the formation of pinholes even by molding.

From the viewpoint of further improving the electrolytic solution resistance of the packaging material 3, it is preferable to use a metal foil layer 33 that has been subjected to a chromate treatment.

Examples of chromate treatment include chromate chromate using chromic acid compounds such as chromium nitrate, chromium fluoride, chromium sulfate, chromium acetate, chromium oxalate, chromium biphosphate, chromic acid acetyl acetate, chromium chloride, and potassium sulfate chromium. Treatment: Phosphoric acid chromate treatment using a phosphoric acid compound such as sodium phosphate, potassium phosphate, ammonium phosphate, polyphosphoric acid; aminated phenol having a repeating unit represented by the following general formulas (1) to (4) Examples include chromate treatment using a polymer. 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. Also good.

In the general formulas (1) to (4), X represents a hydrogen atom, a hydroxyl group, an alkyl group, a hydroxyalkyl group, an allyl group or a benzyl group. R ¹ and R ² are the same or different and each represents a hydroxyl group, an alkyl group, or a hydroxyalkyl group. In the general formulas (1) to (4), examples of the alkyl group represented by X, R ¹ and R ² include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, Examples thereof include a linear or branched alkyl group having 1 to 4 carbon atoms such as a tert-butyl group. Examples of the hydroxyalkyl group represented by X, R ¹ and R ² include a hydroxymethyl group, a 1-hydroxyethyl group, a 2-hydroxyethyl group, a 1-hydroxypropyl group, a 2-hydroxypropyl group, 3- C1-C4 straight or branched chain in which one hydroxy group such as hydroxypropyl group, 1-hydroxybutyl group, 2-hydroxybutyl group, 3-hydroxybutyl group, 4-hydroxybutyl group is substituted An alkyl group is mentioned. In the general formulas (1) to (4), the alkyl group and hydroxyalkyl group represented by X, R ¹ and R ² may be the same or different. In the general formulas (1) to (4), X is preferably a hydrogen atom, a hydroxyl group or a hydroxyalkyl group. The number average molecular weight of the aminated phenol polymer having a repeating unit represented by the general formulas (1) to (4) is preferably, for example, 500 to 1,000,000, more preferably about 1,000 to 20,000. preferable.

The amount of the acid-resistant film to be formed on the surface of the metal foil layer 33 in the chromate treatment is not particularly limited. For example, the chromic acid compound is about 0.5 mg to about 0.5 mg in terms of chromium per 1 m ² of the surface of the metal foil layer 33. 50 mg, preferably about 1.0 mg to about 40 mg, phosphorus compound in terms of phosphorus is about 0.5 mg to about 50 mg, preferably about 1.0 mg to about 40 mg, and aminated phenol polymer is about 1 mg to about 200 mg, preferably Is preferably contained at a ratio of about 5.0 mg to 150 mg.

In the chromate treatment, a solution containing a compound used for forming an acid-resistant film is applied to the surface of the metal foil layer 33 by a bar coating method, a roll coating method, a gravure coating method, an immersion method or the like, and then the metal foil layer 33 is applied. This is performed by heating so that the temperature of the liquid becomes about 70 ° C. to 200 ° C. In addition, before the chromate treatment is performed on the metal foil layer 33, the metal foil layer 33 may be previously subjected to a degreasing treatment by an alkali dipping method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method, or the like. By performing the degreasing process in this manner, the chromate process on the surface of the metal foil layer 33 can be performed more efficiently.

Furthermore, the metal foil layer 33 may be subjected to a chemical conversion treatment that imparts corrosion resistance, if necessary. Specifically, as a chemical conversion treatment method for imparting corrosion resistance to the metal foil layer 33, fine particles of metal oxide such as aluminum oxide, titanium oxide, cerium oxide, tin oxide, or barium sulfate are dispersed in phosphoric acid. A method of forming a corrosion-resistant treatment layer on the surface of the metal foil layer 33 by coating the substrate and performing a baking treatment at 150 ° C. or higher can be mentioned. Further, a resin layer obtained by crosslinking a cationic polymer with a crosslinking agent may be further formed on the corrosion-resistant treatment layer. Here, examples of the cationic polymer include polyethyleneimine, an ionic polymer complex composed of a polymer having polyethyleneimine and a carboxylic acid, a primary amine graft acrylic resin obtained by graft polymerization of a primary amine on an acrylic main skeleton, and polyallylamine. Or the derivative, aminophenol, etc. are mentioned. As these cationic polymers, only one type may be used, or two or more types may be used in combination. Examples of the crosslinking agent include a compound having at least one functional group selected from the group consisting of an isocyanate group, a glycidyl group, a carboxyl group, and an oxazoline group, a silane coupling agent, and the like. As these crosslinking agents, only one type may be used, or two or more types may be used in combination.

[Adhesive layer 35]
In the packaging material 3, the adhesive layer 35 is a layer provided as necessary between the metal foil layer 33 and the sealant layer 34 in order to firmly bond the sealant layer 34.

The adhesive layer 35 is formed of an adhesive capable of bonding the metal foil layer 33 and the sealant layer 34. Although there is no restriction | limiting in particular about the composition of the adhesive agent used for formation of the contact bonding layer 35, For example, the resin composition containing a thermosetting resin is mentioned. Specific examples of the thermosetting resin used for the adhesive layer 35 are the same as those exemplified for the adhesive layer 32.

The thickness of the adhesive layer 35 is, for example, about 1 to 40 μm, preferably about 2 to 30 μm.

[Sealant layer 34]
In the packaging material 3, the sealant layer 34 corresponds to the innermost layer, and is a layer that seals the battery element by heat-sealing the sealant layers when the battery is assembled.

The resin component used for the sealant layer 34 is not particularly limited as long as it can be thermally welded, and examples thereof include polyolefins, cyclic polyolefins, carboxylic acid-modified polyolefins, and carboxylic acid-modified cyclic polyolefins.

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

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

The carboxylic acid-modified polyolefin is a polymer obtained by modifying the polyolefin with a carboxylic acid. Examples of the carboxylic acid used for modification include maleic acid, acrylic acid, itaconic acid, crotonic acid, maleic anhydride, itaconic anhydride and the like.

The carboxylic acid-modified cyclic polyolefin is obtained by copolymerizing a part of the monomer constituting the cyclic polyolefin in place of the α, β-unsaturated carboxylic acid or its anhydride, or by α, β with respect to the cyclic polyolefin. A polymer obtained by block or graft polymerization of an unsaturated carboxylic acid or its anhydride. The cyclic polyolefin to be modified with carboxylic acid is the same as described above. The carboxylic acid used for modification is the same as that used for modification of the acid-modified cycloolefin copolymer.

Among these resin components, preferably a crystalline or amorphous polyolefin, a cyclic polyolefin, and a blend polymer thereof; more preferably, polyethylene, polypropylene, a copolymer of ethylene and norbornene, and two or more of these These blend polymers can be mentioned.

The sealant layer 34 may be formed of one kind of resin component alone, or may be formed of a blend polymer in which two or more kinds of resin components are combined. Furthermore, the sealant layer 34 may be formed of only one layer, but may be formed of two or more layers using the same or different resin components.

The thickness of the sealant layer 34 is not particularly limited, but may be about 2 to 2000 μm, preferably about 5 to 1000 μm, and more preferably about 10 to 500 μm.

2. Battery 10
The battery 10 of the present invention includes a battery element 4 including at least a positive electrode, a negative electrode, and an electrolyte; a packaging material 3 that seals the battery element 4; 3 and a metal terminal 2 projecting to the outside. The battery 10 of the present invention is characterized in that the metal terminal adhesive film 1 of the present invention is interposed between the metal terminal 2 and the packaging material 3.

Specifically, the metal terminal of the present invention is a battery element including at least a positive electrode, a negative electrode, and an electrolyte, with the packaging material 3 and the metal terminal 2 connected to each of the positive electrode and the negative electrode protruding outward. The adhesive film 1 is interposed between the metal terminal 2 and the sealant layer 34, and the flange portion of the packaging material (the region where the sealant layers 34 are in contact with each other, the peripheral portion 3 a of the packaging material) on the periphery of the battery element 4. The battery 10 using the packaging material 3 is provided by covering the sealant layers 34 of the flange portion with each other so as to be sealed. When the battery element 4 is accommodated using the packaging material 3, the packaging material 3 is used so that the sealant layer 34 of the packaging material 3 is on the inner side (surface in contact with the battery element 4).

The battery of the present invention may be either a primary battery or a secondary battery, but is preferably a secondary battery. The type of secondary battery is not particularly limited. For example, a lithium ion battery, a lithium ion polymer battery, a lead battery, a nickel / hydrogen battery, a nickel / cadmium battery, a nickel / iron battery, a nickel / zinc battery Examples include batteries, silver oxide / zinc livestock batteries, metal-air batteries, multivalent cation batteries, capacitors, capacitors, and the like. Among these secondary batteries, a lithium ion battery and a lithium ion polymer battery are preferable.

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

Example 1-10
<Manufacture of adhesive film>
An acid-modified polyolefin resin (carboxylic acid-modified polypropylene), the following resin composition for forming an acid-reactive resin layer, and an acid-modified polyolefin resin (carboxylic acid-modified polypropylene) are sequentially laminated to form an acid-modified polyolefin resin layer (thickness). An adhesive film having a laminated structure of 30 μm) / acid reaction resin layer (thickness described in Table 1) / acid-modified polyolefin resin layer (thickness 30 μm) was obtained.
(Resin composition for forming an acid reaction resin layer)
・ Carboxylic acid-modified polypropylene (heat-welding resin)
・ Urea-modified furan resin (HP6200N, manufactured by Asahi Organic Materials Co., Ltd.) Predetermined amounts shown in Table 1

Comparative Example 1
In Example 6, an acid-modified polyolefin resin layer (thickness 30 μm) / acid-reactive resin layer (thickness 40 μm) / It was set as the adhesive film which has a laminated structure of an acid-modified polyolefin resin layer (thickness 30 micrometers).

<Manufacture of battery packaging materials>
Chemical conversion treatment is performed on both sides of an aluminum foil (thickness 40 μm) as a metal foil layer, and a nylon film (thickness 25 μm) is used as a base layer on one chemical conversion treatment surface so that the thickness of the adhesive layer is about 3 μm. Were bonded together by a dry laminating method through a polyester adhesive. Next, a carboxylic acid-modified polypropylene (23 μm) and polypropylene (23 μm) for forming a sealant layer are coextruded on the chemical conversion treatment surface of the other aluminum foil to form a base material layer / adhesive layer / aluminum foil / sealant layer. A laminate was obtained. In addition, all of the chemical conversion treatment of the aluminum foil was performed by applying a roll coating method using an aqueous solution consisting of a phenol resin, a chromium fluoride compound, and phosphoric acid as a treatment liquid, and baking under conditions where the film temperature was 180 ° C. or higher. It was. The amount of chromium applied was 3 mg / m ² (dry weight).

<Short-circuit evaluation between metal terminal and metal foil layer>
Using the adhesive films produced in Examples 1-10 and Comparative Example 1 and the battery packaging material produced above, short-circuit between the metal terminal and the metal foil layer was evaluated. First, the battery packaging material produced above was cut into 60 mm (MD direction, vertical direction) × 150 mm (TD direction, horizontal direction). Next, the cut battery packaging material is folded in half so that the sealant layers face each other in the TD direction, one side in the TD direction and one side in the MD direction are thermally welded, and one side in the TD direction is An open bag-shaped battery packaging material was prepared. The heat welding conditions were a temperature of 190 ° C., a surface pressure of 1.0 MPa, and a heating / pressurization time of 3 seconds. Into this, 3 g of a mixed solution of an electrolytic solution (ethylene carbonate, diethyl carbonate, and dimethyl carbonate (1: 1: 1) adjusted to be 1M LiPF ₆ ) was added.

Next, the adhesive films prepared in Example 1-10 and Comparative Example 1 were temporarily attached to the upper and lower sides of the aluminum metal terminals having a thickness of 100 μm and a width of 4 mm, respectively. A part of the package was inserted outside, and heat sealed so that an adhesive film was interposed between the metal terminal and the sealant layer to obtain each sealed package. The heat seal conditions were 190 ° C., 2.0 MPa, and 3 sec. These packages were left to stand in a thermostatic layer at 85 ° C. for 24 hours with the portion where the opening was located facing upward. Next, cut the heat-sealed part of the metal terminal of these packaging bodies, check the cross-sectional photograph, and those that may short circuit between the metal terminal and the metal foil layer of the battery packaging material, Contact was confirmed by a tester. According to the cross-sectional photograph, a film in which no film was seen between the metal terminal and the metal foil layer was regarded as short-circuited, and a specimen in which a short circuit was confirmed by the tester was defined as a short-circuit. In the package using the adhesive films of Example 1-10 and Comparative Example 1, 100 samples were each subjected to short-circuit evaluation, and the ratio of the short-circuited short-circuit and the total number of short-circuits was confirmed to be the short-circuit ratio. The results are shown in Table 1.

From the results shown in Table 1, it can be seen that the short circuit of the heat sealed portion of the metal terminal is effectively suppressed by having the acid reaction resin layer as the adhesive film of the metal terminal.

DESCRIPTION OF SYMBOLS 1 Adhesive film for metal terminals 2 Metal terminal 3 Packaging material 3a Peripheral part 4 of packaging material Battery element 10 Battery 11 Acid reaction resin layer 12 Polyolefin layer 13 Polyolefin layer 31 Base material layer 32 Adhesive layer 33 Metal foil layer 34 Sealant layer

Claims

An adhesive film for metal terminals interposed between a metal terminal electrically connected to the electrode of the battery element and a packaging material for sealing the battery element,
The said adhesive film for metal terminals is an adhesive film for metal terminals which has an acid reaction resin layer containing acid-modified polyolefin and acid curable resin.
The adhesive film for metal terminals according to claim 1, further comprising a polyolefin layer formed of at least one of polyolefin and acid-modified polyolefin on at least one surface of the acid-reactive resin layer.
2. The adhesive film for metal terminals according to claim 1, further comprising a polyolefin layer formed of an acid-modified polyolefin on at least one surface of the acid reaction resin layer.
The adhesive film for metal terminals according to any one of claims 1 to 3, which has a polyolefin layer formed of an acid-modified polyolefin on both surfaces of the acid reaction resin layer.
The adhesive film for metal terminals according to any one of claims 1 to 4, wherein the acid curable resin is at least one of an acid curable furan resin and an acid curable phenol resin.
6. The adhesive film for metal terminals according to claim 1, wherein the acid-modified polyolefin contained in the acid-reactive resin layer is a polyolefin graft-modified with an unsaturated carboxylic acid or an anhydride thereof.
The adhesive film for metal terminals according to any one of claims 1 to 6, wherein the thickness is 10 to 200 µm.
The packaging material is a laminate having at least a base material layer, an adhesive layer, a metal foil layer, and a sealant layer in this order, and the adhesive film for metal terminals is interposed between the sealant layer and the metal terminals. The adhesive film for a metal terminal according to any one of claims 1 to 7, wherein:
A battery element including at least a positive electrode, a negative electrode, and an electrolyte, a packaging material that seals the battery element, and a metal terminal that is electrically connected to each of the positive electrode and the negative electrode and protrudes outside the packaging material A battery comprising:
A battery in which the metal terminal adhesive film according to any one of claims 1 to 8 is interposed between the metal terminal and the packaging material.