TW201720646A - Laminated body for battery exterior, method for producing laminate for battery exterior, battery exterior body, and battery - Google Patents

Abstract

The present invention provides a novel laminate for battery exterior which can be thinned, which has excellent characteristics and can be manufactured with high yield and high productivity. The battery exterior laminate is a battery exterior laminate having at least a first base material layer, a first adhesive layer, a first corrosion prevention layer, a stainless steel foil, and a second base material layer. The first substrate layer is a layer containing polypropylene or polyethylene, and the first adhesive layer is composed of an adhesive containing a polyolefin having a melting point of 50 to 100 ° C. The thickness of the stainless steel foil is 40 μm or less.

Description

Laminated body for battery exterior, method for manufacturing laminate for battery exterior, and battery exterior Body and battery

The present invention relates to a battery laminate for a good outer casing such as a secondary battery or a capacitor, a method for producing the battery exterior laminate, and a battery exterior body obtained by using the laminate. And battery.

At the same time, as a battery for storing electric energy, a secondary battery such as a lithium ion battery, or a capacitor such as an electric double layer capacitor, attention has been paid attention to the improvement of environmental awareness and the effective use of natural energy such as sunlight and wind power.

For the purpose of miniaturization and weight reduction, as the exterior body used for these batteries, a laminate for battery exteriors in which a metal foil and a resin layer are laminated can be used. Such a battery exterior laminate is molded into a disk shape having a concave portion by a stretch molding or the like, thereby serving as an exterior body container body.

Further, similarly to the outer casing main body, the battery exterior laminate is molded to obtain an outer casing cover. After the battery body is housed in the recessed portion of the body container body, the exterior body cover portion is overlapped so as to cover the battery body to be housed, and the edge portion between the container body and the exterior body cover portion is bonded to obtain the exterior. A battery in which a battery body is housed in the body.

For example, Patent Document 1 discloses a battery exterior laminate for an innermost layer in which a base material layer, an aluminum foil, and an inner layer made of a polypropylene or a polyethylene layer are laminated in this order.

Prior technical literature Patent literature

Patent Document 1: Japanese Laid-Open Patent Publication No. 2012-33393

In the field of application of batteries such as secondary batteries, development of a small-sized and large-capacity battery has been advanced. In the same manner, the laminate for battery exterior also maintains the thinness of the laminate itself while maintaining excellent properties such as mechanical strength, water resistance, and chemical resistance (electrolyte resistance). In general, the mechanical strength, water resistance, chemical resistance (electrolyte resistance), and light blocking property of the laminate for battery exterior are mainly ensured by an inorganic layer such as a metal foil in the laminate for battery exterior. As the metal foil, an aluminum foil excellent in workability is widely used (see Patent Document 1).

However, since the aluminum foil is superior in workability to other metal foils, it is possible to produce a laminate with high yield, and on the other hand, it is inferior to other metal foils in mechanical strength such as puncture strength. Therefore, in order to obtain mechanical strength, the thickness of the aluminum foil cannot be made less than a certain amount, and in the current state of using an aluminum foil, it is difficult to form a laminate for a battery exterior.

The present invention has been made in view of the above circumstances, and it is an object of the invention to provide a novel battery exterior laminate which can be made into a film, which has excellent characteristics and can be manufactured with high yield and high productivity.

In order to achieve the above object, the inventors of the present invention have made the following configuration. By replacing the aluminum foil with a stainless steel foil, the inventors can reduce the mechanical strength such as the puncture strength and thin the film. However, the use of a stainless steel foil of a film for the production of a battery exterior has formed wrinkles of a shape that has not been seen in the past, and this problem has been intensively studied, and the present invention has been completed.

Specifically, as a layer structure which can be dry lamination, it has been found that a base material layer containing polypropylene or polyethylene and a polyolefin adhesive layer having a low melting point are used, and it has been found that The present invention has been completed by producing a laminate for battery wrap without wrinkles with high productivity.

That is, the present invention adopts the following constitution:

A first aspect of the present invention provides a laminate for a battery exterior comprising at least a first base material layer, a first adhesive layer, a first anticorrosive layer, a stainless steel foil, and a second base material layer. A laminate for a battery exterior, characterized in that the first substrate layer is a layer containing polypropylene or polyethylene, and the first adhesive layer is composed of a polyolefin having a melting point of 50 to 100 ° C. The adhesive is composed of a stainless steel foil having a thickness of 40 μm or less.

The first anticorrosive layer is preferably a layer containing a water-soluble resin.

The second substrate layer is preferably a layer composed of polyethylene terephthalate having a thickness of 3 to 11 μm , and the second substrate layer and the stainless steel foil preferably have a second viscosity. Adhesive layer.

The first adhesive layer is preferably a layer composed of an adhesive containing an acid-modified polyolefin resin having a melting point of 50 to 100 ° C and a phenol novolac type epoxy resin.

The first anticorrosive layer preferably contains a water-soluble resin, a halogenated metal compound, and a chelating agent.

According to a second aspect of the invention, in a method of producing a laminate for a battery exterior, the method for producing a laminate for a battery exterior of the first aspect of the invention, characterized in that The first adhesive layer formed on one side of the stainless steel foil is placed in contact with the first base material layer, and the laminate is dry-laid at 70 to 150 °C.

According to a third aspect of the invention, a battery exterior body comprising the battery exterior laminate of the first aspect of the invention, comprising: an internal space for accommodating a battery; The first substrate layer side of the laminate is the inner space side.

A fourth aspect of the invention provides a battery comprising the battery exterior body of the third aspect.

According to the present invention, it is possible to provide a laminate for a battery exterior which has excellent characteristics and can be manufactured with high yield and high productivity. Further, the laminate for battery exterior of the present invention can be formed into a film.

10‧‧‧Layer

11‧‧‧First substrate layer

12‧‧‧First adhesive layer

13‧‧‧First corrosion protection layer

14‧‧‧Stainless steel foil

15‧‧‧Second substrate layer

16‧‧‧Second anti-corrosion layer

17‧‧‧Second adhesive layer

20‧‧‧Battery for battery exterior

27‧‧‧Lithium-ion battery

28‧‧‧Electrode lead

29, 34, 54‧‧‧ Peripheral Department

30‧‧‧ container body

31, 51‧‧‧ recess

32‧‧‧Flange

33‧‧‧ 盖部

40, 60‧‧‧ secondary battery

50‧‧‧Layer

Around 52‧‧

55‧‧‧Formed body

551‧‧‧First area

552‧‧‧Second area

L‧‧‧ fold line

Fig. 1 is a schematic cross-sectional view showing a first aspect of a laminate for battery exterior of the present invention.

Fig. 2 is a schematic flow chart showing an example of a method for producing a laminate for battery exterior of the present invention.

Fig. 3 is a view showing the use of the laminate for battery exterior of the present invention. A perspective view of an example of a secondary battery.

Fig. 4 is a perspective view showing a flow of manufacturing a secondary battery using the laminate for battery exterior of the present invention.

Fig. 5 is a perspective view showing a flow of manufacturing a secondary battery using the laminate for battery exterior of the present invention.

Hereinafter, the present invention will be described based on suitable embodiments. However, the present embodiment is a more specific description of the gist of the invention, and the invention is not limited thereto unless otherwise specified.

[Layer for battery exterior]

The laminate for battery exterior of the first aspect of the present invention (hereinafter sometimes referred to simply as "layered body") is provided with at least a first base material layer, a first adhesive layer, a first anti-corrosion layer, and A laminate for a battery exterior comprising a stainless steel foil and a second base material layer, wherein the first base material layer is a layer containing polypropylene or polyethylene, and the first adhesive layer contains a melting point of 50 It is composed of a polyolefin adhesive of ~100 ° C, and the thickness of the stainless steel foil is 40 μm or less.

Fig. 1 is a cross-sectional view showing a schematic configuration of a laminate 10 for a battery exterior according to an embodiment of the present invention.

The laminate 10 of the present embodiment includes the first base material layer 11, the first adhesive layer 12, the first anti-corrosion layer 13, the stainless steel foil 14, the second anti-corrosion layer 16, and the second adhesive layer 17 in this order. The second base material layer 15 is formed.

That is, the laminated body 10 of the present embodiment is composed of a seven-layer structure including the first anti-corrosion layer 13 and the second anti-corrosion layer 16 formed on both surfaces of the stainless steel foil 14, in the first prevention Corrosion layer 13 via first adhesive layer The first base material layer 11 laminated 12 and the second base material layer 15 laminated on the second anti-corrosion layer 16 via the second adhesive layer 17 are formed.

Each layer will be described in detail below.

The first base material layer 11 is a layer containing polypropylene or polyethylene. From the viewpoint of good adhesion to the first adhesive layer 12, it is preferred to have a homopolymer and a block copolymer of propylene or ethylene, and more preferably The polypropylene film and/or the polyethylene film particularly preferably contain at least a polypropylene film. By using these materials, the first base material layer 11 and the stainless steel foil 14 having the first anti-corrosion layer 13 on the surface can be well bonded via the first adhesive layer 12.

The first base material layer 11 may have a single layer structure or a multilayer structure. As an example of the first base material layer 11 having a multilayer structure, a two-layer film in which a polyethylene terephthalate (PET) resin film is laminated on a polypropylene film is exemplified. Further, the first base material layer 11 may have a multilayer structure in which three or more films are laminated. When the first base material layer 11 has a multilayer structure, it is preferable to arrange the layer containing polypropylene or polyethylene so as to be in contact with the first adhesive layer 12.

The melting point of the polypropylene film or the polyethylene film used in the first base material layer 11 is not particularly limited as long as the battery exterior laminate 10 has desired heat resistance.

For example, the thickness of the first base material layer 11 can be made 1 to 30 μm.

The first adhesive layer 12 is a layer composed of an adhesive containing a polyolefin having a melting point of 50 to 100 °C.

Conventionally, lamination of a metal foil and a base resin layer is performed mainly by thermal lamination. This is because, in the case where the surface of the base resin layer is melted by thermal lamination and is welded to the metal foil by the high temperature, it is not necessary to provide between the metal foil and the base resin layer. The adhesive layer is placed, and thus the curing time of the adhesive layer is not required.

However, stainless steel foils having low thermal conductivity and difficulty in thermal expansion are more difficult to propagate heat than other metal foils such as aluminum foil. Therefore, in the case where the stainless steel foil is subjected to a high temperature, deformation (curl) is likely to occur in the width direction of the stainless steel foil. In the case where the stainless steel foil is used for thermal lamination, heat may not be sufficiently propagated in the plane, and a portion that is not in contact with the hot-pressing roller may be generated in the width direction without being in contact with the roller, sometimes in the case of Bending and wrinkling occur due to deformation itself during hot pressing. Further, in the case where the stainless steel foil is heated to a high temperature which is not deformed, the productivity is lowered due to a decrease in the processing speed or an increase in the amount of heat required.

Therefore, in the present invention, by providing a layer composed of an adhesive having a lower melting point polyolefin having a melting point of 50 to 100 ° C, it is possible to use a lower temperature at which the stainless steel foil is not deformed, that is, The stainless steel foil having the first anticorrosive layer and the first base material layer are adhered via the first adhesive layer at a temperature of around 100 ° C or below. Examples of the bonding method at 100 ° C or lower include dry lamination. Then, by bonding at a relatively low temperature such as dry lamination, it is possible to improve not only the low yield due to bending or wrinkling of the stainless steel foil, but also the time required for thermal lamination and the improvement of work efficiency. Further, by providing the adhesive layer, the adhesion between the first base material layer and the (with the first anti-corrosion layer) stainless steel foil is also improved as compared with the case where the base resin is melted by thermal lamination. The strength of the entire product is increased, and even when the laminate is exposed to chemicals such as an electrolyte or water or the like, the laminate is not damaged.

The first adhesive layer 12 can be formed, for example, by applying an adhesive containing a polyolefin having a melting point of 50 to 100 ° C to the surface of the stainless steel foil 14 on which the first anticorrosive layer 13 is provided and drying.

Hereinafter, the "adhesive containing a polyolefin having a melting point of 50 to 100 ° C" (hereinafter sometimes referred to simply as "layered body") will be described.

Adhesive

In the present invention, the adhesive for forming the first adhesive layer 12 is not particularly limited as long as it contains a polyolefin having a melting point of 50 to 100 ° C, and preferably contains an acid-modified melting point of 50 to 100 ° C. Adhesive for olefin resin. By using the acid-modified polyolefin resin, the first adhesive layer 12 suitable for the adhesion of the first substrate layer 11 and the (with the first anti-corrosion layer 13) stainless steel foil 14 can be obtained.

Hereinafter, the "acid-modified polyolefin resin having a melting point of 50 to 100 ° C" may be simply referred to as "acid-modified polyolefin resin".

(acid modified polyolefin resin)

In the present invention, the acid-modified polyolefin resin is a polyolefin-based resin modified with an unsaturated carboxylic acid or a derivative thereof, and the polyolefin-based resin has an acid functional group such as a carboxyl group or a carboxylic anhydride group.

The acid-modified polyolefin resin is obtained by modification of a polyolefin resin by an unsaturated carboxylic acid or a derivative thereof, or copolymerization of an acid-functional monomer and an olefin. Among them, the acid-modified polyolefin resin is preferably obtained by acid-modifying a polyolefin resin.

As the acid modification method, graft modification of a melt-kneading polyolefin resin and an acid-functional monomer may be exemplified in the presence of a radical polymerization initiator such as an organic peroxide or an aliphatic azo compound. .

The polyolefin-based resin may, for example, be a polyethylene, a polypropylene, a poly-1-butene, a polyisobutylene, a random copolymer of propylene and ethylene or an α-olefin, or a propylene. A block copolymer with ethylene or an alpha-olefin. Among them, homopolypropylene (propylene homopolymer; hereinafter sometimes referred to as "homopoly PP"), propylene-ethylene block copolymer (hereinafter sometimes referred to as "block PP"), and propylene-ethylene are preferred. A polypropylene resin such as a copolymer (hereinafter sometimes referred to as "random PP") is particularly preferably a random PP.

Examples of the olefins in the case of copolymerization include olefin monomers such as ethylene, propylene, 1-butene, isobutylene, 1-hexene, and α-olefin.

The acid-functional group monomer is a compound having an ethylenic double bond, a carboxyl group or a carboxylic acid anhydride group in the same molecule, and examples thereof include acid anhydrides of various unsaturated monocarboxylic acids, dicarboxylic acids or dicarboxylic acids.

Examples of the acid-functional monomer (carboxyl group-containing monomer) having a carboxyl group include acrylic acid, methacrylic acid, maleic acid, nadic acid, fumaric acid, itaconic acid, citraconic acid, crotonic acid, and isocrotonic acid. , tetrahydrofurfuric acid, internal bicyclo [2.2.1]-5-heptene-2,3-dicarboxylic acid (5-norbornene-2,3-dicarboxylic acid (endic acid), etc. α,β- Unsaturated carboxylic acid monomer.

Examples of the acid group-containing monomer (carboxyl group-containing monomer) having a carboxylic anhydride group include unsaturated anhydrides such as maleic anhydride, nadic anhydride, itaconic anhydride, citraconic anhydride, and norbornene dianhydride. Dicarboxylic anhydride monomer.

These acid-functional group monomers may be used alone or in combination of two or more kinds in the acid-modified polyolefin resin.

Among them, the acid-functional group monomer is preferably an acid-containing functional group having an acid anhydride group, more preferably an acid-containing anhydride group-containing monomer, and particularly preferably maleic anhydride, because it has high reactivity with an epoxy resin to be described later.

In the case where a part of the acid-functional monomer used in the acid modification is unreacted, in order to prevent the adhesion of the unreacted acid-containing monomer, the adhesion is lowered. Low, it is preferred to use a substance in which an unreacted acid-containing functional group monomer is removed in advance as an acid-modified polyolefin resin.

In the acid-modified polyolefin resin, the polyolefin resin or the olefin-derived component is preferably 50 parts by mass or more based on 100 parts by mass of the total amount of the acid-modified polyolefin resin.

The acid-modified polyolefin resin has a melting point of 50 to 100 ° C, preferably 80 ° C to 100 ° C. By using such an acid-modified polyolefin resin having a melting point, the softening temperature (melting point) of the first adhesive layer 12 itself can be lowered, and the first base material layer 11 can be bonded with a lower temperature (with the first corrosion prevention) Stainless steel foil 14 of layer 13).

Among them, as the acid-modified polyolefin resin, maleic anhydride-modified polypropylene is preferred from the viewpoint of adhesiveness and an appropriate melting point. The formation of the first adhesive layer 12 used in the dry lamination is suitable by using polypropylene which is soluble in an organic solvent.

The binder in the present invention may further contain an additive compound in addition to the acid-modified polyolefin resin. The additive compound may, for example, be a resin having an epoxy group (hereinafter referred to as "epoxy resin"). By containing an epoxy resin, the crosslinked structure formed by the adhesive becomes denser, and the adhesion of the first adhesive layer 12 is further improved.

(epoxy resin)

The epoxy resin is not particularly limited as long as it has two or more epoxy groups in one molecule, and examples thereof include a phenoxy resin synthesized from a bisphenol and epichlorohydrin, a phenol novolac epoxy resin, and a bisphenol. Type epoxy resin, etc. Among them, due to the high epoxy content per molecule, in particular, a dense crosslinked structure can be formed, This preferably uses a phenol novolac epoxy resin.

The phenol novolak type epoxy resin in the present invention is a compound having a phenol novolac resin obtained by acid condensation of phenol and formaldehyde as a basic structure, and an epoxy group is introduced into a part of the structure. The amount of the epoxy group introduced per molecule of the phenol novolak type epoxy resin is not particularly limited, but a large amount of the phenolic hydroxyl group present in the phenol novolac resin is introduced into the phenolic phenolic resin by reacting an epoxy group material such as epichlorohydrin with a phenol novolac resin. Epoxy groups are therefore typically multifunctional epoxy resins.

Among them, the phenol novolak type phenolic epoxy resin is preferably a bisphenol A novolac epoxy resin having a phenol novolak structure as a basic skeleton and having a bisphenol A structure. Further, the bisphenol A structure in the epoxy resin may be a structure derived from bisphenol A, and a hydroxyl group at both ends of the bisphenol A may be replaced with a group such as an epoxy group-containing group.

An example of the bisphenol A novolak type epoxy resin is a resin represented by the following formula (1).

[Chemical Formula 1]

In the formula (1), R ¹ to R ⁶ are each independently a hydrogen atom or a methyl group, n is an integer of 0 to 10, and R ^X is a group having an epoxy group.

In the formula (1), R ¹ to R ⁶ are each independently a hydrogen atom or a methyl group. When n is an integer of 2 or more, R ³ and R ⁴ may be the same or different. Among the resins represented by the formula (1), at least one of the following (i) to (iii) is preferably satisfied.

(i) Both R ¹ and R ² are methyl; (ii) both R ³ and R ⁴ are methyl; (iii) both R ⁵ and R ⁶ are methyl.

For example, by satisfying the above (i), in the formula (1), the carbon atom to which R ¹ and R ² are bonded and the two hydroxyphenyl groups to which the carbon atom is bonded constitute a structure derived from bisphenol A.

In the formula (1), R ^X is a group having an epoxy group. Examples of the group having an epoxy group include an epoxy group, a combination of an epoxy group and an alkylene group, and the like, and a glycidyl group is preferred.

The epoxy equivalent of the bisphenol A novolac epoxy resin is preferably from 100 to 300, more preferably from 200 to 300. The epoxy equivalent (g/eq) is the molecular weight of an epoxy group of one epoxy group, and the smaller the value, the more the epoxy group in the resin. By using an epoxy resin having a small epoxy equivalent, even when the amount of the epoxy resin added is small, the adhesion of the epoxy resin to the adherend is good, and the epoxy resin and the acid change The polyolefin resin is sufficiently crosslinked.

As the bisphenol A novolac epoxy resin, jER154, jER157S70, and jER-157S65 manufactured by Mitsubishi Chemical Corporation; EPICLON N-730A, EPICLON N-740, EPICLON N-770, and EPICLON N-made by DIC Corporation can also be used. 775 (all of the above are trade names) and other commercial products.

It is considered that by using the above epoxy resin, both the acid functional group of the acid-modified polyolefin resin and the epoxy group of the epoxy resin are bonded as a functional group for a binder (particularly, a hydroxyl group having a binder). The functional group functions, and thus the first base material layer 11 and the (having the first anti-corrosion layer 13) stainless steel foil 14 can have excellent adhesion.

Further, it is considered that a part of the acid functional group of the acid-modified polyolefin resin reacts with a part of the epoxy group of the epoxy resin to form a crosslinked structure of the acid-modified polyolefin resin and the epoxy resin, according to the crosslinked structure, the resin The strength is enhanced, and excellent durability is obtained while obtaining excellent adhesion.

The adhesive used in the present invention is preferably 1 to 20 parts by mass, more preferably 100 parts by mass, based on 100 parts by mass of the acid-modified polyolefin resin. The epoxy resin is contained in an amount of 5 to 10 parts by mass based on 100 parts by mass of the acid-modified polyolefin resin, and particularly preferably 5 to 7 parts by mass based on 100 parts by mass of the acid-modified polyolefin resin.

The adhesive used in the present invention may further contain an additive having an additive property, an additional resin, a plasticizer, a stabilizer, a colorant or the like as appropriate.

Further, the adhesive of the present invention may or may not further contain an organic solvent.

An adhesive which is liquid-like by containing an organic solvent can be, for example, an adhesive suitable for dry lamination. The adhesive layer can be formed by coating and drying the liquid adhesive on the lower layer, and the adhesive layer can be bonded by dry lamination.

On the other hand, in the case where the organic solvent is not contained, the polyolefin resin and the epoxy resin are melt-kneaded, and after extrusion molding or the like, an adhesive layer suitable for thermal lamination or the like can be formed.

In the case of containing an organic solvent, the organic solvent to be used is not particularly limited as long as it can dissolve the resin as appropriate, and for example, toluene or the like can be used. The amount of the organic solvent used is not particularly limited, and the solid content is preferably 3 to 30% by mass, more preferably 5 to 25% by mass, still more preferably 10 to 20% by mass.

The thickness of the first adhesive layer 12 can be, for example, 0.5 to 10 μm . By making the thickness within this range, the first base material layer 11 and the stainless steel foil 14 can be bonded with high adhesion, and interlayer peeling can be prevented.

In the present aspect, the first anti-corrosion layer 13 is a layer formed for surface modification of the stainless steel foil 14, and is a layer for preventing corrosion due to rust or the like of the stainless steel foil 14.

The first anticorrosive layer 13 in the present aspect is formed by applying a water-soluble paint containing a water-soluble resin, a halogenated metal compound, and a chelating agent, followed by drying and curing.

Water soluble coating

(water soluble resin)

As the water-soluble resin, one or more of a polyvinyl alcohol-based resin and a polyvinyl ether-based resin are preferably used.

The polyvinyl alcohol-based resin is a water-soluble resin selected from at least one of a polyvinyl alcohol resin and a modified polyvinyl alcohol resin.

The polyvinyl alcohol-based resin can be produced, for example, by saponifying a polymer of a vinyl ester monomer or a copolymer thereof.

Examples of the polymer of the vinyl ester monomer or a copolymer thereof include a vinyl ester monomer such as a vinyl acetate such as vinyl acetate, vinyl acetate or vinyl butyrate or an aromatic vinyl ester such as vinyl benzoate. a homopolymer or a copolymer, a copolymer of other monomers copolymerizable therewith, and the like.

Examples of other monomers copolymerizable include olefins such as ethylene and propylene, ether group-containing monomers such as alkyl vinyl ether, diacetone acrylamide, diacetone (meth) acrylate, and allyl acetate. A carbonyl group-containing (keto group) monomer such as acetonitrile acetate, an unsaturated carboxylic acid such as acrylic acid, methacrylic acid or maleic anhydride, a halogenated vinyl compound such as vinyl chloride or vinylidene chloride, or an unsaturated sulfonic acid.

The degree of saponification of the polyvinyl alcohol-based resin is usually preferably from 90 to 100 mol%, more preferably 95 mol% or more.

Examples of the polyvinyl alcohol-based resin include an alkyl ether-modified polyvinyl alcohol resin, a carbonyl-modified polyvinyl alcohol resin, an ethyl acetate-modified polyvinyl alcohol resin, and an acetamidine resin. An amine-modified polyvinyl alcohol resin, an acrylonitrile-modified polyvinyl alcohol resin, a carboxyl group-modified polyvinyl alcohol resin, an anthrone-modified polyvinyl alcohol resin, an ethylene-modified polyvinyl alcohol resin, or the like. Among them, an alkyl ether-modified polyvinyl alcohol resin, a carbonyl-modified polyvinyl alcohol resin, a carboxyl group-modified polyvinyl alcohol resin, and an ethyl acetate-modified polyvinyl alcohol resin are preferable.

As a commercially available product of a polyvinyl alcohol-based resin, for example, J-POVAL DF-20 (trade name) manufactured by VAM & POVAL Co., Ltd., Japan, and CROSSMER H series manufactured by Japan CARBIDE Industrial Co., Ltd. ( Product name). One type or a mixture of two or more types may be used for the polyvinyl alcohol-based resin.

Examples of the polyvinyl ether-based resin include ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, 2-ethylhexyl vinyl ether, and cyclohexyl vinyl ether. a homopolymer or copolymer of an aliphatic vinyl ether such as norbornene vinyl ether, allyl vinyl ether, norbornene vinyl ether, 2-hydroxyethyl vinyl ether, diethylene glycol monovinyl ether, and the like a copolymer of other monomers copolymerized therewith. Examples of the other monomer copolymerizable with the vinyl ether monomer include the same as those of the other monomer copolymerizable with the vinyl ester monomer.

In particular, 2-hydroxyethyl vinyl ether, diethylene glycol monovinyl ether, 2-hydroxypropyl vinyl ether, and various other diols or monovinyl ethers of polyhydric alcohols, etc., have a hydroxyl group in the monomer. The polyvinyl ether-based resin of the aliphatic vinyl ether can be suitably used in the present invention because it has water solubility and can undergo a crosslinking reaction with respect to a hydroxyl group.

These polyvinyl ether-based resins can be used in the production (polymerization) step of the resin because the vinyl ether monomer is different from the polyvinyl alcohol-based resin produced by the vinyl ester-based polymer, and can be produced without undergoing saponification treatment. In addition, it can also be made A copolymer containing a vinyl ester monomer or a vinyl ether monomer or a vinyl alcohol-vinyl ether copolymer obtained by saponifying it. A mixture of a polyvinyl alcohol-based resin other than a polyvinyl ether-based resin and a polyvinyl ether-based resin may also be used.

As the water-soluble resin, any of a polyvinyl alcohol-based resin and a polyvinyl ether-based resin may be used alone or in combination of two.

(halogenated metal compound)

The halogenated metal compound preferably has water solubility because it needs to be mixed with the above water-soluble resin.

Examples of the halogenated metal compound include chromium halide, iron halide, zirconium halide, titanium halide, cesium halide, titanium hydrohalide, and salts thereof. Examples of the halogen atom include chlorine, bromine and fluorine, and preferably chlorine or fluorine. Further, fluorine is particularly preferred.

Among them, as the halogenated metal compound, a chloride or a fluoride of iron, chromium, manganese or zirconium is preferable.

The halogenated metal compound has an effect of improving chemical resistance such as electrolyte resistance. That is, the surface of the stainless steel foil 14 is passivated, and the corrosion resistance to the electrolytic solution can be improved. The metal halide compound also has a function of crosslinking the water-soluble resin.

(chelating agent)

The water soluble coating contains a chelating agent. The chelating agent is a material which is coordinately bonded to a metal ion to form a metal ion complex.

The chelating agent binds a metal compound (chromium oxide or the like) derived from a metal halide compound to the water-soluble resin, and in order to increase the compressive strength of the first anti-corrosion layer 13, even if the thickness of the first anti-corrosion layer 13 is, for example, more than 0.2 μ In the case of m and 1.0 μm or less, embrittlement cracking or peeling of the first anticorrosive layer 13 does not occur. Therefore, the bonding strength between the stainless steel foil 14 and the first adhesive layer 12, and the bonding strength between the stainless steel foil 14 and the layer on the upper layer side thereof can also be improved.

Further, the chelating agent has a function of hydrating the water-soluble resin by chemically reacting with a water-soluble resin or a metal halide compound.

As the chelating agent, for example, an aminocarboxylic acid type chelating agent, a phosphonic acid type chelating agent, a hydroxycarboxylic acid type, or a (poly)phosphoric acid type chelating agent can be used.

Examples of the aminocarboxylic acid-based chelating agent include nitrilotriacetic acid (NTA), hydroxyethyliminodiacetic acid (HIDA), ethylenediaminetetraacetic acid (EDTA), and hydroxyethylethylenediaminetriacetic acid (HEDTA). Diethylenetriaminepentaacetic acid (DTPA), triethylenetetramine hexaacetic acid (TTHA), transcyclohexanediaminetetraacetic acid (CyDTA), 1,2-propanediaminetetraacetic acid (1,2-PDTA) ), 1,3-propanediaminetetraacetic acid (1,3-PDTA), 1,4-butanediaminetetraacetic acid (1,4-BDTA), 1,3-diamino-2-hydroxypropanetetraacetic acid ( DPTA-OH), ethylene glycol diethyl ether diamine tetraacetic acid (GEDTA), ethylenediamine o-hydroxyphenylacetic acid (EDHPA), SS-ethylenediamine disuccinic acid (SS-EDDS), ethylenediamine disuccinic acid ( EDDS), β -alanine diacetic acid (ADA), methyl glycine diacetic acid (MGDA), L-aspartic acid-N,N-diacetic acid (ASDA), L-glutamic acid-N,N- Diacetic acid (GLDA), N,N'-bis(2-hydroxyphenyl)ethylenediamine-N,N'-diacetic acid (HBEDDA).

The phosphonic acid-based chelating agent is not particularly limited as long as it has a structure of -P(=O)(OH) ₂ derived from phosphonic acid (HP(=O)(OH) ₂ ), and examples thereof include N, N. , N-trimethylene phosphonic acid (NTMP), 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP), ethylenediamine-N,N,N',N'-tetramethylenephosphonic acid (EDTMP), diethylene triamine penta methylene phosphonic acid (DTPMP), 2-phosphonic acid butane-1,2,4-tricarboxylic acid (PBTC), nitrile tris (methylene phosphonic acid) ) (NTMP).

Examples of the hydroxycarboxylic acid-based chelating agent include glycolic acid, citric acid, malic acid, gluconic acid, and glucoheptonic acid.

Examples of the (poly)phosphoric acid chelating agent include phosphoric acid, metaphosphoric acid, tripolyphosphoric acid, tetrapolyphosphoric acid, pyrophosphoric acid, orthophosphoric acid, hexametaphosphoric acid, and salts thereof.

As a commercially available product of a chelating agent which can be generally used, for example, an aminocarboxylic acid chelating agent such as CHELEST PD-4H (PDTA); CHELEST PH-540 (EDTMP), CHELEST PH-210 (HEDP), and CHELEST PH-320 (CHELEST PH-320) can be cited. Phosphonic acid chelating agents such as NTMP) and CHELEST PH-430 (PBTC) (all of which are chelating agents manufactured by CHELEST Co., Ltd., identified as trade names).

Among them, as the chelating agent, a phosphoric acid chelating agent (phosphoric acid compound) such as a phosphonic acid chelating agent or a (poly)phosphoric acid chelating agent is preferable, and a phosphonic acid chelating agent is more preferable.

Among all the solid components of the water-soluble paint, the water-soluble resin is preferably 3 to 30% by mass, more preferably 5 to 20% by mass, still more preferably 10 to 15% by mass. Further, among all the solid components of the water-soluble paint, the halogenated metal compound is preferably 20 to 60% by mass, more preferably 30 to 55% by mass, still more preferably 40 to 50% by mass. Among all the solid components of the water-soluble paint, the chelating agent is preferably 20 to 60% by mass, more preferably 30 to 50% by mass, still more preferably 35 to 45% by mass.

The water-soluble paint can be produced by dissolving a water-soluble resin, a metal halide compound, and a chelating agent in a solvent containing water. As the solvent, water is preferred.

After considering the coatability of the first anticorrosive layer 13, etc., the solid content concentration in the water-soluble paint can be appropriately determined, and it can be generally 0.1 to 10% by mass.

The thickness of the first anti-corrosion layer 13 is preferably 0.05 μm or more, more preferably more than 0.1 μm . By setting the thickness of the first anticorrosive layer 13 to 0.05 μm or more, the battery exterior laminate 10 can be sufficiently corroded, and the stainless steel foil 14 and the first adhesive layer 12 can be improved. The bonding strength and the bonding strength between the stainless steel foil 14 and the first substrate layer 11.

Further, the thickness of the first anticorrosive layer 13 is preferably 1.0 μm or less, more preferably 0.5 μm or less. By setting the thickness of the first anticorrosive layer 13 to 1.0 μm or less, the bonding strength of the stainless steel foil 14 and the first adhesive layer 12 can be improved, and the material cost can be suppressed.

The stainless steel foil 14 is a metal foil made of stainless steel, and is made of, for example, stainless steel such as austenite, ferrite or martensite. SUS304, 316, and 301 are used as the austenite, SUS430 or the like as the ferrite, and SUS410 or the like as the martensite.

The stainless steel foil 14 has higher mechanical strength such as puncture strength and tensile strength than other metal foils such as aluminum foil, and when the thickness is 40 μm or less, sufficient mechanical strength of the battery exterior laminate 10 can be given. . As a result, the stainless steel foil 14 and the laminate 10 as a whole can be thinned.

Further, since the mechanical strength is high, when the concave portion is formed by the drawing, the occurrence of pin holes can be reduced, and as a result, leakage of the sealed contents (for example, battery liquid leakage) in the laminated body can be reduced. Further, since the stainless steel foil 14 is superior in corrosion resistance to other metal foils, deterioration due to corrosion can be satisfactorily prevented.

The thickness of the stainless steel foil 14 is 40 μm or less, preferably 5 to 40 μm , more preferably 5 to 30 μm , and particularly preferably 10 to 20 μm . When it is set to the above lower limit value, the battery exterior laminate 10 is given sufficient mechanical strength, and when used in a battery such as a secondary battery, the durability of the battery can be improved. In addition, by setting the thickness of the stainless steel foil 14 to 40 μm or less, the battery exterior laminate 10 can be sufficiently thin, and sufficient drawability can be imparted.

The second anti-corrosion layer 16 has the same structure as the first anti-corrosion layer 13.

The second adhesive layer 17 may have the same structure as the first adhesive layer 12, or may be a layer composed of an ordinary urethane-based adhesive or an epoxy-based adhesive. The thickness of the second adhesive layer 17 can be, for example, 0.5 to 10 μm . By setting the thickness to this range, the second base material layer 15 and the stainless steel foil 14 can be bonded with high adhesion, and interlayer peeling can be prevented.

The second base material layer 15 is not particularly limited as long as it has sufficient mechanical strength, and for example, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), or polyparaphenylene can be used. Polyester resin such as butylene glycol formate (PBT); polyamine resin such as nylon (Ny); olefin resin such as stretched polypropylene (OPP); polyetheretherketone (PEEK), polyphenylene sulfide (PPS) A synthetic resin film composed of the like. Among them, a PET film is preferred.

The thickness of the second base material layer 15 can be, for example, 1 to 50 μm , preferably 1 to 30 μm , and more preferably 3 to 11 μm .

The second substrate layer 15 may have a single layer structure or a multilayer structure. As an example of the second base material layer 15 having a multilayer structure, a two-layer film in which a polyethylene terephthalate (PET) resin film is laminated on a biaxially stretched polyamide resin film (ONy) is exemplified. . Further, the second base material layer 15 may have a multilayer structure in which three or more layers of the film are laminated.

Further, in the embodiment shown in Fig. 1, the second base material layer 15 is the outermost layer. Therefore, the second base material layer can have a desired color and design by containing a resin and a coloring agent such as a pigment.

The second base material layer 15 is preferably composed of a single layer or a multilayer film using a heat resistant resin film having a melting point of 200 ° C or higher. As such a heat resistant resin film, for example, a PET film, a PEN film, a PBT film, a nylon film, a PEEK film, a PPS film, or the like is used, and a PET film which is advantageous in terms of cost is particularly preferable. By using such a heat-resistant resin film, the heat resistance of the battery exterior laminate 10 can be improved, and the durability of the battery using the battery exterior laminate 10 can be improved.

In the battery exterior laminate 10 shown in Fig. 1, the first anticorrosive layer 13 and the second anticorrosive layer 16 are formed on both surfaces of the stainless steel foil 14, and the battery using the battery exterior laminate 10 is used. The outer casing is used as the inner surface side, and is in contact with the electrolytic solution or the like on the first base material layer 11 side. Therefore, the anticorrosive layer is formed at least on the side of the first base material layer 11 of the stainless steel foil 14. In other words, the second anticorrosive layer 16 can be omitted from the battery exterior laminate 10 of Fig. 1 .

In the battery exterior laminate 10 shown in Fig. 1, the second base material layer 15 serves as the outermost layer, but a coating layer may be formed on the outer surface side of the second base material layer 15.

The coating layer (first coating layer) is composed of a urethane resin, an acrylic resin, a polyvinylidene chloride, a vinylidene chloride-vinyl chloride copolymer resin, a maleic anhydride-modified polypropylene resin, a polyester resin, Epoxy resin, phenol resin, phenoxy resin, fluororesin, cellulose ester resin, cellulose ether resin, polyamide resin, polyphenylene ether resin (PPE), polyphenylene sulfide resin (PPS), polyarylene ether resin At least one resin selected from the group consisting of (PAE) and polyetheretherketone resin (PEEK) form. The coating layer is preferably made of a material having excellent heat resistance. These resins may be used alone or in combination of two or more.

The coating layer is preferably a film-cured layer formed by coating and drying a solvent-based coating prepared by dissolving the resin in a common organic solvent.

By the formation of the coating layer, the insulation of the battery exterior laminate 10 can be improved, and the surface of the battery exterior laminate 10 can be prevented from being damaged. Further, even when the battery exterior laminate 10 is in contact with the electrolytic solution, it is possible to prevent a change in appearance (discoloration or the like).

Further, the coating layer can be colored by adding a coloring agent and a pigment to the solvent-based coating material forming the coating layer. In addition, it is also possible to add coloring and printing to display characters, graphics, images, patterns, and the like on the coating layer, thereby improving the design feeling.

The thickness of the coating layer can be, for example, 0.1 to 20 μm , preferably 2 to 10 μm .

In the battery exterior laminate 10 shown in Fig. 1, the second base material layer 15 and the second adhesive layer 17 are directly bonded to each other, but may be provided on the inner surface side of the second base material layer 15. A printed layer for improving the sense of design.

The printed layer can have the same configuration as the above-described coating layer.

The thickness of the battery exterior laminate 10 is preferably 10 to 500 μm , more preferably 20 to 200 μm , still more preferably 30 to 100 μm .

The battery using the battery-packed body 10 includes a secondary battery such as a lithium ion battery or a capacitor such as an electric double layer capacitor as a secondary battery, and an organic electrolyte is used for the electrolytic solution. The organic electrolyte is usually a solvent such as a carbonate such as propylene carbonate (PC), ethylene carbonate (DEC) or ethylene carbonate, but is not particularly limited to these.

[Method for Producing Laminate for Battery Exterior Assembly]

A method for producing a laminate for a battery exterior according to a second aspect of the present invention (hereinafter sometimes referred to simply as "the manufacturing method") is a method for producing a laminate for a battery exterior of the first aspect, and for example, the following steps can be used. The manufacturing is performed such that the first adhesive layer formed on one side of the stainless steel foil is in contact with the first base material layer, and the laminate is dry-laid at 70 to 150 °C.

More specifically, for example, it can be manufactured by a method having the steps of: forming a first anticorrosive layer on one side of a stainless steel foil; forming a first adhesive layer on the formed first anticorrosive layer And a step of disposing the first substrate layer in contact with the formed first adhesive layer and dry laminating the laminate at 70 to 150 °C.

The details are described below.

First, as shown in Fig. 2(a), the first anticorrosive layer 13 is formed on one surface of the stainless steel foil 14.

Specifically, the water-soluble paint is applied onto the surface of the stainless steel foil 14, and then dried by heating. At this time, only the first anti-corrosion layer 13 can be formed by applying only the water-soluble paint on one side of the stainless steel foil 14, as shown in Fig. 2(a), or by coating on both sides of the stainless steel foil 14. The water-soluble coating is applied while forming the second anti-corrosion layer 16. Further, in the case where the second anti-corrosion layer 16 is provided, the second anti-corrosion layer 16 is preferably formed in a stage before the formation of the first adhesive layer 12 or the like, and more preferably simultaneously with the first anti-corrosion layer 13.

Further, in the case where the first anticorrosive layer 13 and the second anticorrosive layer 16 are simultaneously formed, it is also preferable to immerse the stainless steel foil 14 in a water-soluble paint, and to heat the water-soluble paint on both sides of the stainless steel foil 14 dry.

Next, as shown in FIG. 2(b), in the first anti-corrosion layer 13 A first adhesive layer 12 is formed thereon.

Specifically, a layer composed of the above-mentioned adhesive agent is formed on the surface of the stainless steel foil 14 on which the first anticorrosive layer 13 is provided, and heating and drying are required as needed. For example, after dissolving the polyolefin resin and the epoxy resin contained in the desired organic solvent in the organic solvent, the first adhesive layer 12 is formed by coating the solution on the first anti-corrosion layer 13 and drying. Further, the formation of the first adhesive layer 12 can be carried out as a series of steps using a conventional dry laminator or the like together with the step of FIG. 2(c) described later.

Thereafter, as shown in FIG. 2(c), the first base material layer 11 is placed in contact with the formed first adhesive layer 12, and the laminate is dried at 70 to 150 ° C. Cascade.

Specifically, a film constituting the first base material layer 11 is prepared in advance, and the film is placed on the first adhesive layer, followed by dry lamination. The temperature of the dry lamination is not particularly limited as long as it is a temperature at which the first base material layer 11 and the first anticorrosive layer 13 and the stainless steel foil 14 can be adhered well via the first adhesive layer, and it is conceivable to constitute the first bonding. The material or melting point of the adhesive of the agent layer 12 is determined. The temperature at the time of dry lamination is generally 70 to 150 ° C, preferably 80 to 120 ° C. The pressure at the time of dry lamination is preferably set to 0.1 to 0.5 MPa.

In the manufacturing method of the present embodiment, since the first base material layer 11 and the first anticorrosive layer 13 and the stainless steel foil 14 are bonded via the first adhesive layer 12, dry lamination can be employed for bonding. Then, by using dry lamination instead of the warm lamination which is required to exceed 200 ° C in the conventional lamination, the temperature at the time of lamination can be greatly reduced. As a result, it is possible to eliminate the bending and wrinkles at the time of thermocompression caused by the deformation in the case where the stainless steel foil is given a high temperature, and it can be used as gold. It is a stainless steel foil with excellent foil strength. Further, since it is difficult to cause bending or wrinkles at the time of thermocompression bonding, the yield is improved by adopting dry lamination which does not require high temperature such as thermal lamination.

Further, the step of forming the first adhesive layer 12 and the step of disposing the first base material layer 11 for dry lamination may be carried out as a series of steps using a conventional dry laminating apparatus.

The method of forming the second anti-corrosion layer 16, the second adhesive layer 17, and the second base layer 15 is not particularly limited. For example, as shown in FIG. 2(d), the second base layer 15 is formed in advance. The second adhesive layer 17 serves as a laminate composed of two layers. Thereafter, the two-layer laminate and the first substrate layer 11, the first adhesive layer 12, and the first protection layer are provided in such a manner that the second adhesive layer 17 is in contact with the second anti-corrosion layer 16. The laminate of the etching layer 13, the stainless steel foil 14, and the second anticorrosive layer 16 is dry-laminated, and a battery exterior laminate 10 composed of seven layers can be produced.

In the above, the first and second embodiments of the present invention have been described with reference to the battery exterior laminate 10 shown in Figs. 1 to 2, and the technical scope of the present invention is not limited to the above embodiment, and is not deviated. Various modifications can be added within the scope of the gist of the invention.

For example, the second anti-corrosion layer 16 may not be provided to have a six-layer structure.

In addition, other layers may be disposed on a side of the first base material layer 11 that is not in contact with the first adhesive layer 12 and a side of the second base material layer 15 that is not in contact with the second adhesive layer 17 . Thus, it becomes a structure of seven or more layers.

[battery case]

A battery exterior body according to a third aspect of the present invention is the battery provided with the first aspect The battery exterior body of the laminate for exterior molding has an internal space in which the battery is housed, and the first base material layer side of the battery exterior laminate is the battery exterior body on the internal space side. Specifically, the battery exterior laminate of the first aspect is molded into a desired shape by facing the inner space of the first base material layer, and an object obtained by sealing the end portion or the like is required.

The shape, size, and the like of the battery exterior body are not particularly limited and may be appropriately determined depending on the type of battery to be used.

The battery exterior body may be composed of one member, or may be formed by combining two or more members (for example, a container body and a lid portion) as will be described later in FIG.

〔battery〕

A battery according to a fourth aspect of the present invention includes the battery exterior body of the third aspect.

Examples of the battery include a secondary battery such as a lithium ion battery as a secondary battery, or a battery using an organic electrolyte in an electrolytic solution such as a capacitor such as an electric double layer capacitor.

As an example, a perspective view of the secondary battery 40 is shown in FIG. The secondary battery 40 includes a lithium ion battery 27 in the battery exterior container 20.

The container exterior container 20 is formed by stacking the container body 30 composed of the battery exterior laminate 10 of the first aspect of the present invention and the lid portion 33 composed of the battery exterior laminate 10, and heat-sealing the periphery. The portion 29 is formed. Reference numeral 28 is an electrode lead connected to the positive electrode and the negative electrode of the lithium ion battery 27.

The battery shown in Fig. 3 can be manufactured in the following manner.

First, as shown in Fig. 4 (a), the battery exterior laminate 10 is formed into a disk shape having the concave portion 31, and is molded by a drawing or the like to obtain the container body 30. The depth of the recess 31 can be, for example, 2 mm or more.

A lithium ion battery (the lithium ion battery 27 in Fig. 3) is housed in the recess 31 of the container body 30.

Then, as shown in FIG. 4(b), the lid portion 33 composed of the battery exterior laminate 10 is superposed on the container body 30, and the flange portion 32 and the lid of the container body 30 are heat-sealed. The secondary battery 40 shown in Fig. 3 is obtained in the peripheral portion 34 of the portion 33. That is, in the battery shown in Fig. 3, the cover portion 33 is covered on the upper surface of the container body 30, and the recessed portion 31 and the lid portion 33 form an internal space for accommodating the battery.

Further, the battery of the present invention can also be produced in the following manner.

First, as shown in Fig. 5 (a), the long side of the rectangular battery exterior laminate 50 is pressed from the first base material layer side of the battery exterior laminate 50 by a drawing or the like. A part of one end side is molded to form a molded body 55 having a concave portion 51. The depth of the concave portion 51 can be, for example, 2 mm or more.

Next, the drawings are omitted, and a lithium ion battery (the lithium ion battery 27 in Fig. 2) is housed in the concave portion 51 of the molded body 55.

Next, in a portion of the molded body 55 on the other end side where the concave portion 51 is not formed, a fold line L extending in the short-side direction of the molded body 55 is formed, and is bent on the side of the first base material layer. At this time, in the molded body 55, the region on the side of the concave portion 51 with respect to the fold line L is the "first region 551", and the region on the opposite side to the concave portion 51 with respect to the fold line L is the "second region 552".

Next, the first base material layer of the periphery 52 of the recess 51 in the first region 551 and the first base material layer (peripheral portion 54) overlapping the periphery 52 in the second region 552 are superposed. Thereby overlapping the recess 51 of the first region 551 Two areas 552.

Next, as shown in FIG. 5(b), by heat-sealing the first base material layer around the concave portion 51 and the first base material layer of the second region 552, a battery outer casing having one member is obtained. Secondary battery 60. That is, in the battery shown in Fig. 5(b), the inner space for accommodating the battery is formed by the concave portion 51 and the second region 552 by covering the upper surface of the concave portion 51 with the second region 552.

Example

Hereinafter, the present invention will be described in more detail by way of examples, but the invention is not limited by these examples.

[Examples 1 to 14 and Comparative Examples 1 to 7]

(Example 1)

First, a stainless steel foil having a thickness of 20 μm was prepared. Water-soluble paint (coating amount 12 g/m ² ) was applied to both sides of the stainless steel foil, and heat-dried in an oven at 200 ° C to form a first anti-corrosion layer having a thickness of about 0.2 μm and a second anti-corrosion layer. Floor.

The water-soluble paint is 0.2% by mass of a polyvinyl alcohol skeleton-containing amorphous polymer having a hydroxyl group, 0.8% by mass of FeCl ₂ ‧4H ₂ O, and 0.7% by mass of nitrilotris(methylenephosphonic acid) (product) Name: CHELEST PH-320, CHELEST (share))) An aqueous solution dissolved in water.

Thereafter, a first adhesive is applied on the formed first anticorrosive layer to form a first adhesive layer having a thickness of 3 μm.

The first adhesive is a phenol novolac epoxy resin (Mitsubishi Chemical Co., Ltd.) having 15% by mass of maleic anhydride-modified polypropylene (melting point: 50 ° C) and 7 mass% of bisphenol A structure. Product name: jER157S70, viscosity = 80, The amount of the solid content of the epoxy equivalent = 210) was 15%, and it was obtained by melt-kneading in toluene at room temperature for 10 minutes.

The first adhesive layer formed by laminating the stainless steel foil and the first base material layer composed of a polypropylene resin film having a thickness of 6 μm were laminated by dry lamination at a lamination temperature shown in Table 1. The surface of the dry-stacked stainless steel foil was observed with the naked eye and evaluated under the following evaluation conditions. The results are shown in Table 1 as "wrinkles".

○: No wrinkles and bends occurred on the stainless steel foil.

×: Wrinkles and/or buckling occurred on the stainless steel foil.

Further, a urethane-based adhesive is applied to a second substrate layer composed of a black stretched polyethylene terephthalate (PET) resin film having a thickness of 6 to 8 μm. (The main agent: TM-K55 (trade name, manufactured by Toyo Morton Co., Ltd.), and a curing agent: CAT-10L (trade name, manufactured by Toyo Morton Co., Ltd.)) was molded by a second adhesive layer (thickness: 3 μm).

The second adhesive layer was faced to the second anticorrosive layer in the obtained laminate, and laminated by dry lamination at 80 ° C to obtain a laminate for battery exterior.

A test piece was taken from the laminate for battery exterior, and the test piece was immersed in an electrolytic solution containing 1000 ppm of purified water (ethylene carbonate (DC) / ethylene carbonate (DEC) added with 1 mol/liter of LiPF6 1: In 1 vol% of the electrolyte), it was kept at a temperature of 80 ° C for 3 days.

After immersing the electrolyte for 3 days, the electrolyte was not wiped off for tensile test. The tensile test is based on the peeling measurement method A (90° direction peeling) specified in JIS C6471 "Test method for copper-clad laminate for flexible printed wiring boards". The tensile tester (manufactured by Nippon Denshoku Co., Ltd., trade name: FGS-50E-H) was used. The results of evaluation by the following evaluation criteria are shown in Table 1 as "electrolyte resistance".

A: 4N/15mm or more

B: less than 4N/15mm and 0.1N/15mm or more

C: Cannot be measured due to complete peeling

Further, after immersing in an electrolytic solution for 3 days, it was immersed in water for 1 hour, and then observed by the naked eye, and evaluated by the following evaluation criteria. The results as "after water immersion" are shown in Table 1.

A: delamination was not confirmed at all (peeling between layers)

B: A part of the delamination is confirmed within the allowable range.

C: Complete stripping

(Example 2)

In addition to the maleic anhydride modified polypropylene (melting point 60 ° C) in place of the maleic anhydride modified polypropylene (melting point 50 ° C) in the first adhesive forming the first adhesive layer, In the same manner, a laminate for battery exterior was produced, and the same evaluation as in Example 1 was carried out. The results are shown in Table 1.

(Example 3)

In addition to the maleic anhydride modified polypropylene (melting point 80 ° C) in place of the maleic anhydride modified polypropylene (melting point 50 ° C) in the first adhesive forming the first adhesive layer, In the same manner, a laminate for battery exterior was produced, and the same evaluation as in Example 1 was carried out. The results are shown in Table 1.

(Example 4)

In addition to using the maleic anhydride in the first adhesive forming the first adhesive layer A laminate for a battery exterior was produced in the same manner as in Example 1 except that the polypropylene (melting point: 100 ° C) was used instead of the maleic anhydride-modified polypropylene (melting point: 50 ° C), and the same evaluation as in Example 1 was carried out. The results are shown in Table 1.

(Example 5)

Except for the first adhesive forming the first adhesive layer, an adhesive having only maleic anhydride-modified polypropylene (melting point of 80 ° C) and no phenolic novolac epoxy resin is used. A laminate for a battery exterior was produced in the same manner as in Example 3, and the same evaluation as in Example 1 was carried out. The results are shown in Table 1.

(Example 6)

An aqueous solution obtained by dissolving only 0.7% by mass of nitrilotris(methylenephosphonic acid) (trade name: CHELEST PH-320, manufactured by CHELEST Co., Ltd.) in water is used as the first and second prevention. A laminate for a battery exterior was produced in the same manner as in Example 3 except for the water-soluble coating of the etching layer, and the same evaluation as in Example 1 was carried out. The results are shown in Table 1.

(Example 7)

An aqueous solution obtained by dissolving only 0.2% by mass of a polyvinyl alcohol-containing skeleton-containing amorphous polymer having a hydroxyl group in water was used as the water-soluble paint for forming the first and second anticorrosive layers, and Example 3 A laminate for battery exterior was produced in the same manner, and the same evaluation as in Example 1 was carried out. The results are shown in Table 1.

(Example 8)

An external battery was produced in the same manner as in Example 3 except that an aqueous solution obtained by dissolving 0.8% by mass of CrF ₃ ‧3H ₂ O in water was used as the water-soluble paint for forming the first and second anticorrosive layers. The same evaluation as in Example 1 was carried out by using a laminate. The results are shown in Table 1.

(Example 9)

An external battery was produced in the same manner as in Example 3 except that an aqueous solution obtained by dissolving 0.8% by mass of FeCl ₃ ‧6H ₂ O in water was used as the water-soluble paint for forming the first and second anticorrosive layers. The same evaluation as in Example 1 was carried out by using a laminate. The results are shown in Table 1.

(Examples 10 to 12)

A battery exterior was produced in the same manner as in Example 3 except that the dry lamination temperature of the first adhesive layer and the first base material layer in the laminate containing the stainless steel foil was changed to the temperature shown in Table 1. The same evaluation as in Example 1 was carried out using a laminate. The results are shown in Table 1.

(Example 13)

Except that a 0.2% by mass of non-crystalline polyvinyl alcohol-containing polymer skeleton having a hydroxyl group, 0.8% by mass of CrF ₃ ‧3H ₂ O, 0.7 mass% of nitrilo tris (methylene phosphonic acid) (trade name, (CHELEST PH-320, manufactured by CHELEST Co., Ltd.) An aqueous solution obtained by dissolving in water was used as a water-soluble paint for forming the first and second anticorrosive layers, and a battery outer layer was produced in the same manner as in the third embodiment. The same evaluation as in Example 1 was carried out. The results are shown in Table 1.

(Example 14)

In addition to 0.2% by mass of a polyvinyl alcohol skeleton-containing amorphous polymer having a hydroxyl group, 0.8% by mass of ZrF ₄ and 0.7% by mass of nitrilotris(methylenephosphonic acid) (trade name: CHELEST PH-) In the same manner as in the third embodiment, a laminate for a battery exterior was produced in the same manner as in Example 3, except that the aqueous solution was dissolved in water as a water-soluble paint for forming the first and second anticorrosive layers. The same evaluation as in Example 1 was carried out. The results are shown in Table 1.

(Comparative Example 1)

In addition to the maleic anhydride modified polypropylene (melting point 140 ° C) in place of the maleic anhydride modified polypropylene (melting point 50 ° C) in the first adhesive forming the first adhesive layer, In the same manner as in Example 1, a laminate for battery exterior was produced, and the same evaluation as in Example 1 was carried out. The results are shown in Table 1.

(Comparative Example 2)

A laminate for a battery exterior was produced in the same manner as in Example 3 except that an aluminum foil having a thickness of 40 μm was used instead of the stainless steel foil as the metal foil, and the same evaluation as in Example 1 was carried out. The results are shown in Table 1.

(Comparative Example 3)

A laminate for a battery exterior was produced in the same manner as in Example 3 except that an aluminum foil having a thickness of 20 μm was used instead of the stainless steel foil as the metal foil, and the same evaluation as in Example 1 was carried out. The results are shown in Table 1.

(Comparative Example 4)

A battery was fabricated in the same manner as in Example 3 except that the dry lamination of the first adhesive layer and the first base material layer in the laminate containing the stainless steel foil was changed to the thermal lamination at the temperature shown in Table 1. The laminate for exterior molding was subjected to the same evaluation as in Example 1. The results are shown in Table 1.

(Comparative Example 5)

A battery was fabricated in the same manner as in Comparative Example 1, except that the dry lamination of the first adhesive layer and the first base material layer in the laminate containing the stainless steel foil was changed to the thermal lamination at the temperature shown in Table 1. The laminate for exterior molding was subjected to the same evaluation as in Example 1. The results are shown in Table 1.

(Comparative Example 6)

In addition to changing the dry lamination of the first adhesive layer and the first substrate layer in the laminate containing the stainless steel foil to the thermal lamination of the temperatures shown in Table 1, an aluminum foil having a thickness of 40 μm was used instead of the stainless steel foil. A laminate for a battery exterior was produced in the same manner as in Comparative Example 1, except that the metal foil, and the same evaluation as in Example 1 was carried out. The results are shown in Table 1.

(Comparative Example 7)

A laminate for a battery exterior was produced in the same manner as in Example 3 except that the first anticorrosive layer and the second anticorrosive layer were not provided, and the same evaluation as in Example 1 was carried out. The results are shown in Table 1.

[Table 1]

In Table 1, each ellipsis has the following meaning.

(Ad-PP1): Maleic anhydride modified polypropylene (melting point 50 ° C)

(Ad-PP2): Maleic anhydride modified polypropylene (melting point 60 ° C)

(Ad-PP3): Maleic anhydride modified polypropylene (melting point 80 ° C)

(Ad-PP4): Maleic anhydride modified polypropylene (melting point 100 ° C)

(Ad-PP5): Maleic anhydride modified polypropylene (melting point 140 ° C)

(Ad-EP1): "jER157S70" (trade name, manufactured by Mitsubishi Chemical Corporation) (phenolic novolac epoxy resin having a bisphenol A structure; viscosity = 80; epoxy equivalent = 210)

(M1): containing 0.2% by mass of a polyvinyl alcohol skeleton-containing amorphous polymer having a hydroxyl group, 0.8% by mass of FeCl ₂ ‧4H ₂ O, and 0.7% by mass of nitrilotris(methylenephosphonic acid) ( Product name: aqueous solution of CHELEST PH-320, CHELEST (share)

(M2): 0.7% by mass of nitrilotris(methylenephosphonic acid) (trade name: CHELEST PH-320, manufactured by CHELEST Co., Ltd.)

(M3): 0.2% by mass of a polyvinyl alcohol-containing non-crystalline polymer aqueous solution having a hydroxyl group

(M4): 0.8% by mass of CrF ₃ ‧3H ₂ O aqueous solution

(M5): 0.8% by mass of FeCl ₃ ‧6H ₂ O aqueous solution

(M6): 0.2% by mass of a polyvinyl alcohol skeleton-containing amorphous polymer having a hydroxyl group, 0.8% by mass of CrF3‧3H2O, 0.7% by mass of nitrilotris(methylenephosphonic acid) (trade name: CHELEST) PH-320, an aqueous solution of CHELEST (share)

(M7): 0.2% by mass of a polyvinyl alcohol skeleton-containing amorphous polymer having a hydroxyl group, 0.8% by mass of ZrF ₄ , 0.7% by mass of nitrilotris(methylenephosphonic acid) (trade name: CHELEST PH) -320, CHELEST (share) system of aqueous solution

(SUS1): stainless steel foil with a thickness of 20 μm

(AL1): Aluminum foil with a thickness of 40 μm

(AL2): Aluminum foil with a thickness of 20 μm

As is clear from the results shown in Table 1, the laminates for battery exteriors of Examples 1 to 14 did not wrinkle or bend the stainless steel foil, and when peeled off from the electrolyte solution and water, the peeling was lowered and the mechanical strength was good. Compared with the laminate for battery exterior of Comparative Examples 1 to 7, it has excellent characteristics (processability, mechanical strength, chemical resistant liquid/aqueous).

10‧‧‧Layer

11‧‧‧First substrate layer

12‧‧‧First adhesive layer

13‧‧‧First corrosion protection layer

14‧‧‧Stainless steel foil

15‧‧‧Second substrate layer

16‧‧‧Second anti-corrosion layer

17‧‧‧Second adhesive layer

Claims (8)

A laminate for battery exterior, which is a battery exterior laminate for at least a first base material layer, a first adhesive layer, a first corrosion prevention layer, a stainless steel foil, and a second base material layer The first substrate layer is a layer containing polypropylene or polyethylene, and the first adhesive layer is composed of an adhesive containing a polyolefin having a melting point of 50 to 100 ° C. The stainless steel foil has a thickness of 40 μm or less. The laminate for battery exterior according to the first aspect of the invention, wherein the first anticorrosive layer is a layer containing a water-soluble resin. The laminate for battery exterior according to claim 1 or 2, wherein the second base material layer has a thickness of 3 to 11 μm composed of polyethylene terephthalate. The layer has a second adhesive layer between the second substrate layer and the stainless steel foil. The laminate for battery exterior according to any one of claims 1 to 3, wherein the first adhesive layer is a layer composed of an adhesive, and the adhesive contains An acid-modified polyolefin resin having a melting point of 50 to 100 ° C and a phenol novolac epoxy resin. The laminate for battery exterior according to any one of claims 2 to 4, wherein the first anticorrosive layer contains a water-soluble resin, a halogenated metal compound, and a chelating agent. A method for producing a laminate for a battery exterior, which is a method for producing a laminate for a battery exterior, which is a laminate for a battery exterior according to any one of claims 1 to 5, It is characterized by the following steps, The first adhesive layer formed on one side of the stainless steel foil is placed in contact with the first base material layer, and the laminate is dry-laid at 70 to 150 °C. The battery exterior body of the battery exterior laminate according to any one of claims 1 to 5, further comprising an internal space for accommodating the battery, the battery The side of the first base material layer of the laminate for exterior molding is the side of the internal space. A battery comprising the battery exterior body according to claim 7 of the patent application.