CN109196683B

CN109196683B - Battery packaging material, method for producing same, and battery

Info

Publication number: CN109196683B
Application number: CN201780033375.XA
Authority: CN
Inventors: 天野真; 山下力也
Original assignee: Dai Nippon Printing Co Ltd
Current assignee: Dai Nippon Printing Co Ltd
Priority date: 2016-05-31
Filing date: 2017-05-31
Publication date: 2021-10-08
Anticipated expiration: 2037-05-31
Also published as: JP7041617B2; CN109196683A; JPWO2017209219A1; WO2017209219A1

Abstract

The present invention provides a battery packaging material having high moldability and excellent continuous productivity of a battery. The packaging material for a battery is composed of a laminate having at least a base layer, a barrier layer and a heat-sealable resin layer in this order, wherein the heat-sealable resin layer contains at least 1 selected from an antioxidant, a light stabilizer and a nucleating agent, and an amide-based lubricant, and the wave number of C ═ O stretching vibration of the amide group of the amide-based lubricant is 1650cm, which is measured from an absorption spectrum obtained by dispersing reflected light when infrared light is irradiated onto the surface of the heat-sealable resin layer^‑1and-CH contained in the thermally adhesive resin layer₂1460cm of variable angle vibration^‑1The absorption peak intensity B of (a) is in a range of 0.05 to 0.80 inclusive with respect to an absorption spectrum intensity ratio X of the absorption peak intensity a to the absorption peak intensity B.

Description

Battery packaging material, method for producing same, and battery

Technical Field

The invention relates to a battery packaging material, a method for producing the same, and a battery.

Background

Various types of batteries have been developed in the prior art, and among all the batteries, a packaging material is an indispensable component for packaging battery elements such as electrodes and electrolytes. While metal packaging materials have been used as battery packages in many cases in the prior art, batteries have been required to have various shapes, as well as to be thin and lightweight in recent years, in accordance with the increase in performance of electric vehicles, hybrid electric vehicles, personal computers, cameras, mobile phones, and the like. However, the metal-made battery packaging material that is generally used at present has a drawback that it is difficult to cope with the diversification of shapes and the weight reduction is limited.

Therefore, as a battery packaging material which can be easily processed into various shapes and can be made thinner and lighter, a film-shaped laminate in which a base material layer, an adhesive layer, a barrier layer, and a heat-fusible resin layer are sequentially laminated has been proposed (for example, see patent document 1). In such a film-shaped battery packaging material, the heat-sealable resin layers are opposed to each other, and the peripheral edge portions are heat-sealed by heat sealing to seal the battery element.

In the battery packaging material, a space for housing the battery element is formed by molding in a mold when the battery element is sealed. In this molding, since the battery packaging material is stretched, there is a problem that cracks or pinholes are likely to occur in the barrier layer in the flange portion of the mold. In order to solve such problems, a method of improving the sliding property of the heat-fusible resin layer by applying an amide-based lubricant to the surface of the heat-fusible resin layer of the battery packaging material, or by blending an amide-based lubricant with the resin forming the heat-fusible resin layer and allowing the resultant to bleed out to the surface, or the like, is known. By adopting such a method, the battery packaging material is easily drawn into the mold during molding, and cracks and pinholes in the battery packaging material can be suppressed.

However, if the amount of the amide-based lubricant on the surface of the heat-fusible resin layer is too large, the amide-based lubricant adheres to the mold and forms a lump to contaminate the mold. When another battery packaging material is molded in a state where the mold is contaminated, the lump of the lubricant adhering to the mold adheres to the surface of the battery packaging material and is directly subjected to heat fusion by the heat-fusion resin layer. In this way, when the heat-fusible resin layer is heat-fused, the fusion system of the portion to which the lubricant is adhered becomes uneven, and a sealing failure occurs. In order to prevent this, the frequency of cleaning for removing the lubricant adhering to the die needs to be increased, which causes a problem that the continuous productivity of the battery is lowered.

On the other hand, when the amount of the amide-based lubricant on the surface of the heat-sealable resin layer is too small, the sliding property of the battery packaging material is lowered, which causes a problem that the moldability of the battery packaging material is lowered.

Documents of the prior art

Patent document

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

Disclosure of Invention

Problems to be solved by the invention

In the conventional battery packaging material, an amide-based lubricant is sometimes mixed in the heat-fusible resin layer or coated on the heat-fusible resin layer as described above. However, although the amide-based lubricant applied to the heat-sealable resin layer or the amide-based lubricant blended in the heat-sealable resin layer is set to a predetermined amount, the amide-based lubricant adheres to the mold during molding of the battery packaging material, and thus continuous productivity may be reduced, or cracks or pinholes may be generated in the battery packaging material. For example, in either case of blending an amide-based lubricant in the heat-fusible resin layer or applying an amide-based lubricant on the heat-fusible resin layer, the amount of the amide-based lubricant on the surface of the heat-fusible resin layer varies depending on the storage environment from the production of the battery packaging material to the molding.

Under such circumstances, an object of the present invention is to provide a battery packaging material having a heat-sealable resin layer containing an amide-based lubricant, having high moldability, and having excellent continuous productivity of a battery, a method for producing the battery packaging material, and a battery using the battery packaging material.

Means for solving the problems

To solve the above problems, the present inventionThe inventors of the present invention have made intensive studies. As a result, the inventors have found that a packaging material for a battery having high moldability and excellent continuous productivity of the battery is composed of a laminate having at least a base material layer, a barrier layer and a heat-sealable resin layer in this order, the heat-sealable resin layer contains at least 1 selected from an antioxidant, a light stabilizer and a nucleating agent, and an amide-based lubricant, and the number of wave-length 1650cm of C ═ O stretching vibration of an amide group derived from the amide-based lubricant is measured from an absorption spectrum obtained by dispersing reflected light when infrared light is irradiated onto the surface of the heat-sealable resin layer^-1and-CH derived from the heat-fusible resin layer₂Wave number of variable angle vibration 1460cm^-1The absorption peak intensity B of (a) is in a range of 0.05 to 0.80 inclusive with respect to an absorption spectrum intensity ratio X of the absorption peak intensity a to the absorption peak intensity B. The present invention has been completed based on these findings and further research and study.

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

The packaging material for a battery according to item 1, which comprises a laminate comprising at least a substrate layer, a barrier layer and a heat-sealable resin layer in this order,

the heat-sealable resin layer contains at least 1 selected from the group consisting of an antioxidant, a light stabilizer and a nucleating agent, and an amide lubricant,

the wave number of C ═ O stretching vibration of the amide group of the amide lubricant was determined by an absorption spectrum obtained by dispersing reflected light when infrared rays were irradiated onto the surface of the heat-fusible resin layer, and the wave number was 1650cm^-1and-CH derived from the heat-fusible resin layer₂Wave number of variable angle vibration 1460cm^-1The absorption peak intensity B of (a) is in a range of 0.05 to 0.80 inclusive with respect to an absorption spectrum intensity ratio X of the absorption peak intensity a to the absorption peak intensity B.

The battery packaging material according to item 1, wherein the antioxidant is at least 1 selected from the group consisting of a phenolic antioxidant, a phosphorus antioxidant and a thioether antioxidant,

the light stabilizer is at least one of an ultraviolet absorber and a hindered amine compound.

The battery packaging material according to

item

1 or 2, wherein the heat-fusible resin layer further contains a plasticizer.

The battery packaging material according to any one of claims 1 to 3, wherein the heat-fusible resin layer further contains a flame retardant.

The battery packaging material according to any one of claims 1 to 4, wherein the heat-fusible resin layer contains polyolefin.

The battery according to item 6, wherein a battery element having at least a positive electrode, a negative electrode and an electrolyte is contained in a package formed of the battery packaging material according to any one of items 1 to 5.

The method of manufacturing a packaging material for a battery, comprising:

a step of preparing a battery packaging material comprising a laminate in which at least a base material layer, a barrier layer, and a heat-sealable resin layer are laminated in this order, the heat-sealable resin layer containing at least 1 selected from the group consisting of an antioxidant, a light stabilizer, and a nucleating agent, and an amide lubricant; and

from the absorption spectrum obtained by splitting the reflected light when the surface of the heat-fusible resin layer was irradiated with infrared light, it was confirmed that the wave number of C ═ O stretching vibration obtained by measuring the amide group of the amide lubricant was 1650cm^-1and-CH derived from the heat-fusible resin layer₂1460cm of variable angle vibration^-1And (3) an absorption spectrum intensity ratio X of the absorption peak intensity a calculated from the absorption peak intensity B to the absorption peak intensity B is in a range of 0.05 to 0.80.

Effects of the invention

According to the present invention, a battery packaging material having high moldability and excellent continuous productivity of a battery, a method for producing the battery packaging material, and a battery using the battery packaging material can be provided. The present invention also provides a method for producing the battery packaging material and a battery using the battery packaging material.

Drawings

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

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

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

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

Detailed Description

The battery packaging material is characterized by comprising a laminate having at least a base material layer, a barrier layer and a heat-sealable resin layer in this order, wherein the heat-sealable resin layer contains at least 1 selected from an antioxidant, a light stabilizer and a nucleating agent, and an amide-based lubricant, and the wave number of C ═ O stretching vibration of the amide group of the amide-based lubricant is 1650cm in wave number, measured from an absorption spectrum obtained by dispersing reflected light when infrared light is irradiated onto the surface of the heat-sealable resin layer^-1and-CH derived from the heat-fusible resin layer₂Wave number of variable angle vibration 1460cm^-1The absorption peak intensity B of (a) is in a range of 0.05 to 0.80 inclusive with respect to an absorption spectrum intensity ratio X of the absorption peak intensity a to the absorption peak intensity B. The battery packaging material of the present invention will be described in detail below.

In the present specification, the expression "to" indicating a numerical range indicates that a numerical value indicated on the left side is equal to or more than a numerical value indicated on the right side and is equal to or less than a numerical value indicated on the right side, and for example, the expression of the numerical range "X to Y" means X or more and Y or less.

1. Laminated structure of battery packaging material

For example, as shown in fig. 1 to 4, a battery packaging material 10 of the present invention includes a laminate having a base material layer 1, a barrier layer 3, and a heat-fusible resin layer 4 in this order. In the battery packaging material of the present invention, the base material layer 1 is the outermost layer side, and the heat-sealable resin layer 4 is the innermost layer side. That is, when the battery is assembled, the heat-fusible resin layers 4 located at the outer peripheral edge of the battery element are heat-fused to each other to seal the battery element, so that the battery element is sealed.

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

The total thickness of the laminate constituting the battery packaging material of the present invention is not particularly limited, and from the viewpoint of making the total thickness of the laminate as thin as possible and exhibiting high moldability and high continuous productivity, it is preferably about 160 μm or less, more preferably about 35 to 155 μm, and still more preferably about 45 to 120 μm. The laminate constituting the battery packaging material of the present invention can exhibit excellent insulating properties even when the thickness is as thin as 160 μm or less. Therefore, the battery packaging material of the present invention can contribute to an improvement in the energy density of the battery.

2. Each layer forming the packaging material for batteries

[ base Material layer 1]

In the battery packaging material of the present invention, the base material layer 1 is a layer located on the outermost layer side. The material for forming the base layer 1 is not particularly limited as long as it has insulation properties. Examples of the material for forming the base layer 1 include polyester, polyamide, epoxy resin, acrylic resin, fluororesin, polyurethane, silicone resin, phenolic resin, polyetherimide, polyimide, polycarbonate, and a mixture or copolymer thereof.

Specific examples of the polyester include: polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, a copolyester mainly composed of ethylene terephthalate, a copolyester mainly composed of butylene terephthalate, and the like. Further, as the copolyester mainly containing ethylene terephthalate as a repeating unit, there can be specifically mentioned: copolymer polyesters obtained by polymerizing ethylene terephthalate with ethylene isophthalate having ethylene terephthalate as a main repeating unit (hereinafter referred to simply as poly (terephthalic acid/isophthalic acid) glycol), poly (terephthalic acid/isophthalic acid) glycol, poly (terephthalic acid/adipic acid) glycol, poly (sodium terephthalate/isophthalate) glycol, poly (terephthalic acid/phenyl-dicarboxylic acid) glycol, poly (terephthalic acid/decanedicarboxylic acid) glycol, and the like. Further, as the copolyester mainly containing butylene terephthalate as a repeating unit, there can be specifically mentioned: copolymer polyesters obtained by polymerizing butylene terephthalate with butylene isophthalate having butylene terephthalate as a main repeating unit (hereinafter referred to simply as poly (terephthalic acid/isophthalic acid) butylene terephthalate), poly (terephthalic acid/adipic acid) butylene terephthalate, poly (terephthalic acid/sebacic acid) butylene terephthalate, poly (terephthalic acid/decanedicarboxylic acid) butylene naphthalate, and the like. These polyesters may be used alone in 1 kind, or 2 or more kinds may be used in combination. The polyester has advantages such as excellent electrolyte resistance and difficulty in whitening due to adhesion to the electrolyte, and is suitable for use as a material for forming the substrate layer 1.

Further, as the polyamide, specifically, there can be mentioned: aliphatic polyamides such as nylon 6, nylon 66, nylon 610, nylon 12, nylon 46, and copolymers of nylon 6 and nylon 66; aromatic-containing polyamides such as hexamethylenediamine-isophthalic acid-terephthalic acid copolyamide including a structural unit derived from terephthalic acid and/or isophthalic acid, nylon 6I, nylon 6T, nylon 6IT, nylon 6I6T (I represents isophthalic acid and T represents terephthalic acid), and polymetaxyldiamide (MXD 6); alicyclic polyamides such as poly (aminomethyl) cyclohexyl adipamide (PACM 6); and a polyamide obtained by copolymerizing a lactam component or an isocyanate component such as 4, 4' -diphenylmethane-diisocyanate, a polyester amide copolymer or a polyether ester amide copolymer which is a copolymer of a copolymerized polyamide and a polyester or a polyalkylene ether glycol; copolymers thereof, and the like. These polyamides may be used alone in 1 kind, or 2 or more kinds may be used in combination. The stretched polyamide film has excellent stretchability, can prevent whitening due to cracking of the resin of the base layer 1 during molding, and is suitable for use as a material for forming the base layer 1.

The base material layer 1 may be formed by laminating (structuring a plurality of layers) at least one of resin films and coating layers made of different materials in order to improve pinhole resistance and insulation properties when forming a battery package. Specific examples thereof include: a multilayer structure in which a polyester film and a nylon film are laminated, a multilayer structure in which a plurality of nylon films are laminated, a multilayer structure in which a plurality of polyester films are laminated, and the like. When the base layer 1 has a multilayer structure, a laminate of a biaxially stretched nylon film and a biaxially stretched polyester film, a laminate obtained by laminating a plurality of biaxially stretched nylon films, and a laminate obtained by laminating a plurality of biaxially stretched polyester films are preferable. For example, when the base layer 1 is formed of a 2-layer resin film, it is preferably configured by laminating a polyester resin and a polyester resin, a polyamide resin and a polyamide resin, or a polyester resin and a polyamide resin, and more preferably configured by laminating a polyethylene terephthalate and a polyethylene terephthalate, a nylon and a nylon, or a polyethylene terephthalate and a nylon. In addition, the biaxially stretched polyester is, for example, less likely to cause discoloration when an electrolytic solution adheres to the surface, and therefore, when the substrate layer 1 has a multilayer structure of a laminate of a biaxially stretched nylon film and a biaxially stretched polyester film, the substrate layer 1 preferably has a laminate of a biaxially stretched nylon and a biaxially stretched polyester in this order from the barrier layer 3 side. When the substrate layer 1 has a multilayer structure, the thickness of each layer is preferably 3 to 25 μm.

When the substrate layer 1 has a multilayer structure, the resin films may be bonded with an adhesive or may be directly laminated without using an adhesive. When the bonding is not performed by an adhesive, for example, a method of bonding in a hot-melt state such as a coextrusion lamination method, an interlayer lamination method, or a heat lamination method can be mentioned. In the case of bonding with an adhesive, the adhesive used may be a two-component curing adhesive or a one-component curing adhesive. The bonding mechanism of the adhesive is not particularly limited, and any type of adhesive may be used, such as a chemical reaction type, a solvent volatilization type, a hot-melt type, a hot-press type, an electron beam curing type, or an ultraviolet curing type. Specific examples of the adhesive include the same adhesives as those exemplified for the adhesive layer 2. The thickness of the adhesive may be the same as that of the adhesive layer 2.

In the present invention, it is preferable that a lubricant is adhered to the surface of the base material layer 1 from the viewpoint of improving the moldability of the battery packaging material. The lubricant is not particularly limited, and preferably includes an amide-based lubricant exemplified in the heat-fusible resin layer described later.

When the lubricant is present on the surface of the base layer 1, the amount of the lubricant is not particularly limited, but is preferably about 3mg/m at a temperature of 24 ℃ and a humidity of 60%²More preferably 4 to 15mg/m²About, preferably 5 to 14mg/m²Left and right.

The thickness of the base layer 1 is preferably about 4 μm or more, more preferably about 10 to 75 μm, and further preferably about 10 to 50 μm, from the viewpoint of making the total thickness of the battery packaging material thin and providing a battery packaging material having excellent insulation properties.

[ adhesive layer 2]

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

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

Specific examples of the adhesive components that can be used to form the adhesive layer 2 include: polyester resins such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and copolyester; a polyether adhesive; a polyurethane adhesive; an epoxy resin; a phenolic resin; polyamide resins such as nylon 6, nylon 66, nylon 12, and copolyamide; polyolefin resins such as polyolefin, carboxylic acid-modified polyolefin, and metal-modified polyolefin, and polyvinyl acetate resins; a cellulose-based binder; (meth) acrylic resins; a polyimide-based resin; a polycarbonate; amino resins such as urea resins and melamine resins; rubbers such as chloroprene rubber, nitrile rubber, and styrene-butadiene rubber; silicone resins, and the like. These adhesive components can be used alone in 1, or can be used in combination of 2 or more. Among these adhesive components, a polyurethane adhesive is preferably used.

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

[ Barrier layer 3]

In the battery packaging material, the barrier layer 3 is a layer having a function of improving the strength of the battery packaging material and preventing water vapor, oxygen, light, and the like from entering the battery. The barrier layer 3 is preferably a metal layer, i.e., a layer formed of a metal. Specific examples of the metal constituting the barrier layer 3 include aluminum, stainless steel, and titanium, and aluminum is preferably used. The barrier layer 3 may be formed of, for example, a metal foil or a metal vapor deposition film, an inorganic oxide vapor deposition film, a carbon-containing inorganic oxide vapor deposition film, a film provided with these vapor deposition films, or the like, and is preferably formed of a metal foil, and more preferably an aluminum alloy foil. In the production of the packaging material for a battery, from the viewpoint of preventing the generation of wrinkles or pinholes in the barrier layer 3, the barrier layer is more preferably formed of a soft aluminum alloy foil such as annealed aluminum (JIS H4160: 1994A 8021H-O, JIS H4160: 1994A 8079H-O, JIS H4000: 2014A 8021P-O, JIS H4000: 2014A 8079P-O) or the like.

The thickness of the barrier layer 3 is not particularly limited as long as it can function to block water vapor and the like, and is preferably about 100 μm or less, more preferably about 10 to 100 μm, and even more preferably about 10 to 80 μm, from the viewpoint of reducing the thickness of the battery packaging material.

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

In the general formulae (1) to (4), X represents a hydrogen atom, a hydroxyl group, an alkyl group, a hydroxyalkyl group, an allyl group or a benzyl group. In addition, R¹And R²The same or different from each other, represent a hydroxyl group, an alkyl group or a hydroxyalkyl group. X, R in the general formulae (1) to (4)¹And R²Examples of the alkyl group include a carbon atom such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a tert-butyl groupA linear or branched alkyl group having a sub-number of 1 to 4. In addition, as X, R¹And R²Examples of the hydroxyalkyl group include a linear or branched alkyl group having 1 to 4 carbon atoms, which is substituted with 1 hydroxyl group, such as a hydroxymethyl group, a 1-hydroxyethyl group, a 2-hydroxyethyl group, a 1-hydroxypropyl group, a 2-hydroxypropyl group, a 3-hydroxypropyl group, a 1-hydroxybutyl group, a 2-hydroxybutyl group, a 3-hydroxybutyl group, or a 4-hydroxybutyl group. X, R in the general formulae (1) to (4)¹And R²The alkyl and hydroxyalkyl groups shown may be the same or different from each other. In the general formulae (1) to (4), X is preferably a hydrogen atom, a hydroxyl group or a hydroxyalkyl group. The number average molecular weight of the aminated phenol polymer having the repeating units represented by the general formulae (1) to (4) is, for example, preferably about 500 to 100 ten thousand, and more preferably about 1000 to 2 ten thousand.

Further, as a chemical surface treatment method for imparting corrosion resistance to the barrier layer 3, the following method can be mentioned: an acid-resistant coating film is formed on the surface of the barrier layer 3 by applying a coating film in which fine particles of a metal oxide such as aluminum oxide, titanium oxide, cerium oxide, or tin oxide, or barium sulfate are dispersed in phosphoric acid and baking the coating film at 150 ℃. Further, a resin layer obtained by crosslinking a cationic polymer with a crosslinking agent may be further formed on the acid-resistant coating film. Examples of the cationic polymer include polyethyleneimine, an ionic polymer complex comprising polyethyleneimine and a polymer having a carboxylic acid, a primary amine-grafted acrylic resin obtained by graft-polymerizing a primary amine onto an acrylic backbone, polyallylamine or a derivative thereof, and aminophenol. These cationic polymers may be used alone in 1 kind, or 2 or more kinds may be used in combination. Examples of the crosslinking agent include compounds having at least 1 functional group selected from the group consisting of an isocyanate group, a glycidyl group, a carboxyl group and an oxazoline group, and silane coupling agents. These crosslinking agents may be used alone in 1 kind, or 2 or more kinds may be used in combination.

As a specific method for providing the acid-resistant coating, for example, at least the surface of the aluminum alloy foil on the inner layer side is first degreased by a known treatment method such as an alkali immersion method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method, or an acid activation method, and thereafter, an acid-resistant coating film can be formed by applying a treatment liquid (aqueous solution) containing a metal phosphate such as a chromium phosphate salt, a titanium phosphate salt, a zirconium phosphate salt, or a zinc phosphate salt and a mixture of these metal salts as main components, a treatment liquid (aqueous solution) containing a mixture of a nonmetal salt of phosphoric acid and these nonmetal salts as main components, or a treatment liquid (aqueous solution) containing a mixture of these and an aqueous synthetic resin such as an acrylic resin, a phenolic resin, or a urethane resin to the degreased surface by a known coating method such as a roll coating method, a gravure printing method, or an immersion method. For example, when a treatment is performed with a chromium phosphate treatment liquid, an acid-resistant coating film including chromium phosphate, aluminum oxide, aluminum hydroxide, aluminum fluoride, and the like is formed; when treated with a zinc phosphate-based treatment liquid, an acid-resistant coating film including zinc phosphate hydrate, aluminum phosphate, alumina, aluminum hydroxide, aluminum fluoride, and the like is formed.

As another specific example of the method for providing the acid-resistant coating, for example, the acid-resistant coating can be formed by degreasing at least the surface of the inner layer side of the aluminum alloy foil by a known treatment method such as an alkali immersion method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method, or an acid activation method, and then subjecting the degreased surface to a known anodic oxidation treatment.

As another example of the acid-resistant coating, a phosphate-based coating or a chromic acid-based coating may be mentioned. Examples of the phosphate system include zinc phosphate, iron phosphate, manganese phosphate, calcium phosphate, and chromium phosphate; examples of the chromic acid series include chromic chromate.

As another example of the acid-resistant coating, by forming an acid-resistant coating such as a phosphate, a chromate, a fluoride, or a triazine thiol compound, the following effects can be exhibited: the delamination between the aluminum and the base material layer is prevented during the embossing molding; prevent the dissolution and corrosion of the aluminum surface caused by the hydrogen fluoride generated by the reaction of the electrolyte and the moisture, in particular prevent the dissolution and corrosion of the aluminum oxide on the aluminum surface; and improve the adhesion (wettability) of the aluminum surface; preventing delamination of the substrate layer from the aluminum during thermal welding; the delamination of the base material layer from the aluminum is prevented when the embossed type press molding is performed. Among the materials for forming the acid-resistant coating, the aluminum surface is coated with an aqueous solution containing three components of a phenol resin, a chromium (III) fluoride compound, and phosphoric acid, and the treatment of drying and baking is favorable.

The acid-resistant coating film includes a layer containing cerium oxide, phosphoric acid or a phosphate, an anionic polymer, and a crosslinking agent for crosslinking the anionic polymer, and the phosphoric acid or the phosphate may be added in an amount of about 1 to 100 parts by mass based on 100 parts by mass of the cerium oxide. The acid-resistant coating film preferably has a multilayer structure further including a layer having a cationic polymer and a crosslinking agent for crosslinking the cationic polymer.

More preferably, the anionic polymer is poly (meth) acrylic acid or a salt thereof, or a copolymer mainly composed of (meth) acrylic acid or a salt thereof. The crosslinking agent is preferably at least 1 selected from compounds having any functional group of an isocyanate group, a glycidyl group, a carboxyl group and an oxazoline group, and silane coupling agents.

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

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

Specific examples of the acid-resistant coating film include a coating film containing at least 1 of phosphate, chromate, fluoride, and triazine thiol. Also, an acid-resistant coating film containing a cerium compound is preferable. As the cerium compound, cerium oxide is preferable.

Specific examples of the acid-resistant coating include a phosphate coating, a chromate coating, a fluoride coating, and a triazine thiol compound coating. The acid-resistant coating may be 1 of these, or a combination of a plurality of these. The acid-resistant coating film may be formed by degreasing the chemically treated surface of the aluminum alloy foil and then using a treatment liquid composed of a mixture of a metal phosphate and an aqueous synthetic resin or a treatment liquid composed of a mixture of a nonmetal salt of phosphoric acid and an aqueous synthetic resin.

Among these, composition analysis of the acid-resistant coating film can be performed by, for example, time-of-flight secondary ion mass spectrometry. By the composition analysis of the acid-resistant coating film by the time-of-flight secondary ion mass spectrometry, for example, Ce can be detected⁺And Cr⁺A peak of at least one of (a).

Preferably, the aluminum alloy foil has an acid-resistant coating film containing at least 1 element selected from phosphorus, chromium, and cerium on the surface thereof. Among them, it can be confirmed by X-ray photoelectron spectroscopy that the acid-resistant coating film on the surface of the aluminum alloy foil of the battery packaging material contains at least 1 element selected from phosphorus, chromium, and cerium. Specifically, first, the heat-fusible resin layer, the adhesive layer, and the like laminated on the aluminum alloy foil in the battery packaging material are physically peeled off. Next, the aluminum alloy foil was put into an electric furnace, and organic components present on the surface of the aluminum alloy foil were removed at about 300 ℃ for about 30 minutes. Then, it was confirmed that these elements were contained by X-ray photoelectron spectroscopy on the surface of the aluminum alloy foil.

The amount of the acid-resistant coating film formed on the surface of the barrier layer 3 in the chemical surface treatment is not particularly limited, and for example, in the case of performing the above-mentioned chromate treatment, it is desirable that the barrier layer 3 is formed every 1m²On the surface, the content of the chromium compound is about 0.5 to 50mg, preferably about 1.0 to 40mg, in terms of chromium, the content of the phosphorus compound is about 0.5 to 50mg, preferably about 1.0 to 40mg, in terms of phosphorus, and the content of the aminated phenol polymer is about 1.0 to 200mg, preferably about 5.0 to 150 mg.

The thickness of the acid-resistant coating is not particularly limited, but is preferably about 1nm to 10 μm, more preferably about 1 to 100nm, and still more preferably about 1 to 50nm, from the viewpoint of the aggregating power of the coating and the adhesion to the barrier layer 3 or the heat-sealing resin layer 4. The thickness of the acid-resistant coating film can be measured by observation with a transmission electron microscope or by a combination of observation with a transmission electron microscope and an energy-dispersive X-ray spectroscopy or electron beam energy loss spectroscopy.

The chemical surface treatment is carried out by the following method: after a solution containing a compound for forming an acid-resistant coating film is applied to the surface of the barrier layer by a bar coating method, a roll coating method, a gravure coating method, a dipping method, or the like, the barrier layer is heated to a temperature of about 70 to 200 ℃. Before the barrier layer is subjected to the chemical surface treatment, the barrier layer may be subjected to a degreasing treatment in advance by an alkali immersion method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method, or the like. By performing the degreasing treatment in this manner, the chemical surface treatment of the surface of the barrier layer can be more effectively performed.

[ Heat-fusible resin layer 4]

In the battery packaging material of the present invention, the heat-fusible resin layer 4 corresponds to the innermost layer, and is a layer in which the heat-fusible resin layers are heat-fused to each other at the time of assembling the battery to seal the battery element.

The resin component used for the heat-fusible resin layer 4 is not particularly limited as long as it can be heat-fused, and examples thereof include 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, linear low density polyethylene, etc.; polypropylene such as homopolypropylene, a block copolymer of polypropylene (for example, a block copolymer of propylene and ethylene), a random copolymer of polypropylene (for example, a random copolymer of propylene and ethylene), and the like; ethylene-butene-propylene terpolymers, and the like. Among these polyolefins, polyethylene and polypropylene are preferably cited.

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

The carboxylic acid-modified polyolefin is a polymer modified by block polymerization or graft polymerization of 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, and itaconic anhydride.

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

Among these resin components, carboxylic acid-modified polyolefins; more preferably, carboxylic acid-modified polypropylene is used.

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

The heat-fusible resin layer 4 contains an amide lubricant. Specific examples of the amide-based lubricant include saturated fatty amides, unsaturated fatty amides, substituted amides, methylol amides, saturated fatty bisamides, and unsaturated fatty bisamides. Specific examples of the saturated fatty amide include lauramide, palmitamide, stearamide, behenamide, and hydroxystearamide. Specific examples of the unsaturated fatty amide include oleamide and erucamide. Specific examples of the substituted amide include N-oleyl palmitamide, N-stearyl stearamide, N-stearyl oleamide, N-oleyl stearamide, N-stearyl erucamide and the like. Specific examples of the methylolamide include methylolstearylamide and the like. Specific examples of the saturated fatty bisamide include methylene bisstearamide, ethylene biscapramide, ethylene bislauramide, ethylene bisstearamide, ethylene bishydroxystearamide, ethylene bisbehenamide, hexamethylene bisstearamide, hexamethylene bisbehenamide, hexamethylene hydroxystearamide, N '-distearyldiamide, N' -distearyldisebacamide, and the like. Specific examples of the unsaturated fatty bisamide include ethylene bisoleamide, ethylene biserucamide, hexamethylene bisoleamide, N '-dioleyl adipamide, N' -dioleyl sebacamide, and the like. Specific examples of the fatty acid ester amide include stearamide ethyl stearate. Specific examples of the aromatic bisamide include xylylene bisstearamide, xylylene bishydroxystearamide, and N, N' -distearyl isophthalamide. The lubricant may be used alone in 1 kind, or may be used in combination of 2 or more kinds.

The content of the amide-based lubricant in the heat-sealable resin layer 4 is not particularly limited, and the amide-based lubricant and at least 1 selected from an antioxidant, a light stabilizer and a nucleating agent, which will be described later, are contained in the heat-sealable resin layer 4, and from the viewpoint that the amount of the amide-based lubricant on the surface of the heat-sealable resin layer 4 is an amount suitable for moldability and continuous productivity (that is, the absorption spectrum intensity ratio X is in the above range), the content is preferably about 500 to 2000ppm, more preferably about 700 to 1800 ppm.

In the present invention, the heat-fusible resin layer 4 contains the amide-based lubricant and at least 1 selected from the group consisting of an antioxidant, a light stabilizer and a nucleating agent, and thus the amount of the amide-based lubricant located on the surface of the heat-fusible resin layer 4 can be appropriately set to the absorption spectrum intensity ratio X described later suitable for moldability and continuous productivity. The details of this mechanism are not clear, but it is considered that the amide group of the amide lubricant and the functional group that generates a hydrogen bond such as a hydroxyl group, a carbonyl group, or a carboxyl group contained in an antioxidant, a light stabilizer, or a nucleating agent, or other substances that initiate intermolecular interactions, interact with each other, and that a large amount of the amide lubricant exudes to the surface of the heat-fusible resin layer 4 can be effectively suppressed.

The content of at least 1 selected from the group consisting of an antioxidant, a light stabilizer and a nucleating agent in the heat-sealable resin layer 4 is not particularly limited, but is preferably about 100 to 2000ppm, more preferably about 300 to 1500ppm, from the viewpoint of achieving an absorption spectrum intensity ratio X suitable for moldability and continuous productivity, since the heat-sealable resin layer 4 contains the amide-based lubricant. When 2 or more of the antioxidant, the light stabilizer and the nucleating agent are contained in the heat-sealable resin layer 4, the total amount thereof is preferably within the above range.

The antioxidant is not particularly limited, and is contained in the heat-sealable resin layer 4 together with the amide-based lubricant, and therefore, from the viewpoint of suitably improving moldability and continuous productivity of the battery packaging material, a phenol-based antioxidant, a phosphorus-based antioxidant, a thioether-based antioxidant, and the like are preferably exemplified. The antioxidant may be used alone in 1 kind, or may be used in combination of 2 or more kinds.

Examples of the phenolic antioxidant include: 2, 6-di-tert-butyl-4-ethylphenol, 2-tert-butyl-4, 6-dimethylphenol, styrenated phenol, 2 '-methylenebis (4-ethyl-6-tert-butylphenol), 2' -thiobis- (6-tert-butyl-4-methylphenol), 2 '-thiodiethylenebis [ 3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ], 2-methyl-4, 6-bis (octylthiomethyl) phenol, 2' -isobutylenebis (4, 6-dimethylphenol), isooctyl-3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate, N '-hexane-1, 6-diylbis [ 3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionamide, 2' -oxamide-bis [ ethyl-3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ], (methyl-ethyl-4-hydroxy-phenyl) propionate), 2-ethylhexyl-3- (3 ', 5 ' -di-tert-butyl-4 ' -hydroxyphenyl) propionate, 2 ' -ethylenebis (4, 6-di-tert-butylphenol), an ester of 3, 5-bis (1, 1-dimethylethyl) -4-hydroxy-benzenepropanoic acid with a C13-15 alkyl group, 2, 5-di-tert-amylhydroquinone, a polymer of hindered phenol (manufactured by Adeka Palmarol, trade name AO. OH998), 2 ' -methylenebis [ 6- (1-methylcyclohexyl) p-cresol ], 2-tert-butyl-6- (3-tert-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate, 2- [ 1- (2-hydroxy-3, 5-di-tert-amylphenyl) ethyl ] -4, 6-di-tert-amylphenyl acrylate, 6- [ 3- (3-tert-butyl-4-hydroxy-5-methyl) propoxy ] -2, 4,8, 10-tetra-tert-butylbenzo [ d, f ] [1,3,2] -dioxaphospha-heptacyclo (dioxaphosphospin), hexamethylenebis [ 3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate, bis [ monoethyl (3, 5-di-tert-butyl-4-hydroxybenzyl) phosphonic acid calcium salt, the reaction product of 5, 7-bis (1, 1-dimethylethyl) -3-hydroxy-2 (3H) -benzofuranone and o-xylene, 2, 6-di-tert-butyl-4- (4, 6-bis (octylthio) -1, 3, 5-triazin-2-ylamino) phenol, DL-a-tocopherol (vitamin E), 2, 6-bis (. alpha. -methylbenzyl) -4-methylphenol, bis [3, 3-bis- (4 '-hydroxy-3' -tert-butyl-phenyl) butanoic acid ] ethylene glycol ester, 2, 6-di-tert-butyl-p-cresol, 2, 6-diphenyl-4-octadecyloxyphenol, stearyl (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate, distearyl (3, 5-di-tert-butyl-4-hydroxybenzyl) phosphonate, tridecyl-3, 5-di-tert-butyl-4-hydroxybenzylthioacetate, thiodiethylene bis [ (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ], 4 '-thiobis (6-tert-butyl-m-cresol), 2-octylthio-4, 6-bis (3, 5-di-tert-butyl-4-hydroxyphenoxy) s-triazine, 2' -methylenebis (4-methyl-6-tert-butylphenol), ethylene glycol bis [3, 3-bis (4-hydroxy-3-tert-butylphenyl) butyrate ], 4 '-butylidenebis (2, 6-di-tert-butylphenol), 4' -butylidenebis (6-tert-butyl-3-methylphenol), 2,2 '-ethylenebis (4, 6-di-tert-butylphenol), 1, 3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, bis [ 2-tert-butyl-4-methyl-6- (2-hydroxy-3-tert-butyl-5-methylbenzyl) phenyl ] terephthalate, 1,3, 5-tris (2, 6-dimethyl-3-hydroxy-4-tert-butylbenzyl) isocyanurate, 1,3, 5-tris (3, 5-di-tert-butyl-4-hydroxybenzyl) -2, 4, 6-trimethylbenzene, 1,3, 5-tris [ (3, 5-di-tert-butyl-4-hydroxyphenyl) propionyloxyethyl ] isocyanurate, tetrakis [ methylene-3- (3', 5 '-di-tert-butyl-4' -hydroxyphenyl) propionate ] methane, 2-tert-butyl-4-methyl-6- (2-acryloyloxy-3-tert-butyl-5-methylbenzyl) phenol, 3, 9-bis [ 2- (3-tert-butyl-4-hydroxy-5-methylhydrocinnamoyloxy) -1, 1-dimethylethyl ] -2, 4,8, 10-tetraoxaspiro [5.5] undecane, triethylene glycol bis [ beta- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionate ], stearyl-3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionamide, and 3- (3, 5-dialkyl-4-hydroxyphenyl) propionic acid derivatives such as palmityl-3- (3, 5-di-t-butyl-4-hydroxyphenyl) propionamide, myristyl-3- (3, 5-di-t-butyl-4-hydroxyphenyl) propionamide, and lauryl-3- (3, 5-di-t-butyl-4-hydroxyphenyl) propionamide.

Examples of the phosphorus-based antioxidant include: triphenyl phosphite, diisooctyl phosphite, heptyl trisphosphite (heptakisphosphate), triisodecyl phosphite, diphenylisooctyl phosphite, diisooctyl phenyl phosphite, diphenyltridecyl phosphite, triisooctyl phosphite, trilauryl phosphite, diphenyl phosphite, tris (dipropylene glycol) phosphite, diisodecyl pentaerythritol diphosphite, dioleyl hydrogen phosphite, trilauryl trithiophosphite, bis (tridecyl) phosphite, triisodecyl phosphite, tris (tridecyl) phosphite, diphenyldecyl phosphite, dinonylphenyl bis (nonylphenyl) phosphite, poly (dipropylene glycol) phenyl phosphite, tetraphenyldipropyleneglycol diphosphite, trisnonylphenyl phosphite, tris (2, 4-di-tert-butylphenyl) phosphite, tris (2), 4-di-tert-butyl-5-methylphenyl) phosphite, tris [ 2-tert-butyl-4- (3-tert-butyl-4-hydroxy-5-methylphenylsulfanyl) -5-methylphenyl ] phosphite, tridecyl phosphite, octyldiphenyl phosphite, didecylmonophenyl phosphite, distearylpentaerythritol diphosphite, a mixture of distearylpentaerythritol and calcium stearate, alkyl (C10) bisphenol A phosphite, ditridecyl) pentaerythritol diphosphite, di (nonylphenyl) pentaerythritol diphosphite, bis (2, 4-di-tert-butylphenyl) pentaerythritol diphosphite, bis (2, 6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, bis (2,4, 6-tri-tert-butylphenyl) pentaerythritol diphosphite, bis (2, 4-dicumylphenyl) pentaerythritol diphosphite, Tetraphenyl-tetrakis (tridecyl) pentaerythritol tetraphosphite, bis (2, 4-di-tert-butyl-6-methylphenyl) ethyl phosphite, tetrakis (tridecyl) isopropylidenediphenol diphosphite, tetrakis (tridecyl) -4, 4 '-n-butylidenebis (2-tert-butyl-5-methylphenol) diphosphite, hexa (tridecyl) -1, 1, 3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butanetriphosphite, tetrakis (2, 4-di-tert-butylphenyl) biphenylene diphosphonite, 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, (1-methyl-1-propyl-3-ylidene) tris (2-1, 1-dimethylethyl) -5-methyl-4, 1-phenylene) hexa-tridecyl phosphite, 2' -methylenebis (4, 6-tert-butylphenyl) -2-ethylhexyl phosphite, 2 '-methylenebis (4, 6-di-tert-butylphenyl) octadecyl phosphite, 2' -ethylenebis (4, 6-di-tert-butylphenyl) fluorophosphite, 4 '-butylidenebis (3-methyl-6-tert-butylphenyl ditridecyl) phosphite, tris (2- [ (2,4,8, 10-tetra-tert-butylbenzo [ d, f ] -1, 3,2] dioxaphosphorinan-6-yl) oxy ] ethyl) amine, 3, 9-bis (4-nonylphenoxy) -2, 4,8, 10-tetraoxy-3, 9-diphosphaspiro [5,5] undecane, 2,4, 6-tri-tert-butylphenyl-2-butyl-2-ethyl-1, 3-propanediol phosphite, poly-4, 4' -isopropylidenediphenol C12-15-ol phosphite, Phosphite esters of 2-ethyl-2-butylpropanediol and 2,4, 6-tri-tert-butylphenol, and the like.

Examples of the thioether-based antioxidant include: tetrakis [ methylene-3- (laurylthio) propionate ] methane, bis (methyl-4- [ 3-n-alkyl (C12/C14) thiopropionyloxy ] 5-t-butylphenyl) sulfide, ditridecyl 3,3 '-thiodipropionate, dilauryl 3, 3' -thiodipropionate, dimyristyl 3,3 '-thiodipropionate, distearyl 3, 3' -thiodipropionate, lauryl/stearyl thiodipropionate, 4 '-thiobis (6-t-butyl-m-cresol), 2' -thiobis (6-t-butyl-p-cresol), distearyl disulfide.

When the heat-fusible resin layer 4 contains an antioxidant, the content thereof is not particularly limited, but is preferably about 100 to 2000ppm, more preferably about 300 to 1500ppm, from the viewpoint of achieving an absorption spectrum intensity ratio X suitable for moldability and continuous productivity, because the antioxidant is contained in the heat-fusible resin layer 4 together with the amide-based lubricant.

Examples of the light stabilizer include an ultraviolet absorber and a hindered amine compound.

Examples of the ultraviolet absorber include: 2-hydroxybenzophenones such as 2, 4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octyloxybenzophenone, and 5, 5' -methylenebis (2-hydroxy-4-methoxybenzophenone); 2- (2-hydroxy-5-methylphenyl) benzotriazole, 2- (2-hydroxy-5-tert-octylphenyl) benzotriazole, 2- (2-hydroxy-3, 5-di-tert-butylphenyl) -5-chlorobenzotriazole, 2- (2-hydroxy-3-tert-butyl-5-methylphenyl) -5-chlorobenzotriazole, 2- (2-hydroxy-3, 5-dicumylphenyl) benzotriazole, 2' -methylenebis (4-tert-octyl-6-benzotriazolylphenol), polyethylene glycol ester of 2- (2-hydroxy-3-tert-butyl-5-carboxyphenyl) benzotriazole, 2- [ 2-hydroxy-3- (2-acryloyloxyethyl) -5-methylphenyl ] benzotriazole, 2- [ 2-hydroxy-3- (2-methacryloyloxyethyl) -5-tert-butylphenyl ] benzotriazole, 2- [ 2-hydroxy-3- (2-methacryloyloxyethyl) -5-tert-octylphenyl ] benzotriazole, and mixtures thereof, 2- (2-hydroxy-3- (2-methacryloyloxyethyl) -5-tert-butylphenyl ] -5-chlorobenzotriazole, 2- [ 2-hydroxy-5- (2-methacryloyloxyethyl) phenyl ] benzotriazole, 2- [ 2-hydroxy-3-tert-butyl-5- (2-methacryloyloxyethyl) phenyl ] benzotriazole, 2- [ 2-hydroxy-3-tert-pentyl-5- (2-methacryloyloxyethyl) phenyl ] benzotriazole, 2- [ 2-hydroxy-3-tert-butyl-5- (3-methacryloyloxypropyl) phenyl ] -5-chlorobenzotriazole, 2- [ 2-hydroxy-4- (2-methacryloyloxymethyl) phenyl ] benzotriazole, 2- [ 2-hydroxy-4- (3-methacryloyloxy-2-hydroxypropyl) phenyl ] benzotriazole, 2- [ 2-hydroxy-4- (3-methacryloyloxypropyl) phenyl ] benzotriazole and the like -hydroxyphenyl) benzotriazoles; 2- (2-hydroxy-4-methoxyphenyl) -4, 6-diphenyl-1, 3, 5-triazine, 2- (2-hydroxy-4-hexyloxyphenyl) -4, 6-diphenyl-1, 3, 5-triazine, 2- (2-hydroxy-4-octyloxyphenyl) -4, 6-bis (2, 4-dimethylphenyl) -1, 3, 5-triazine, 2- [ 2-hydroxy-4- (3-C12-13 mixed alkoxy-2-hydroxypropoxy) phenyl ] -4, 6-bis (2, 4-dimethylphenyl) -1, 3, 5-triazine, 2- [ 2-hydroxy-4- (2-acryloyloxyethoxy) phenyl ] -4, 6-bis (4-methylphenyl) -1, 3, 5-triazine, 2- (2, 4-dihydroxy-3-allylphenyl) -4, 6-bis (2, 4-dimethylphenyl) -1, 2- (2-hydroxyphenyl) -4, 6-diaryl-1, 3, 5-triazines such as 3, 5-triazine and 2,4, 6-tris (2-hydroxy-3-methyl-4-hexyloxyphenyl) -1, 3, 5-triazine; benzoic acid esters such as phenyl salicylate, resorcinol monobenzoate, 2, 4-di-tert-butylphenyl-3, 5-di-tert-butyl-4-hydroxybenzoate, octyl (3, 5-di-tert-butyl-4-hydroxy) benzoate, dodecyl (3, 5-di-tert-butyl-4-hydroxy) benzoate, tetradecyl (3, 5-di-tert-butyl-4-hydroxy) benzoate, hexadecyl (3, 5-di-tert-butyl-4-hydroxy) benzoate, octadecyl (3, 5-di-tert-butyl-4-hydroxy) benzoate and behenyl (3, 5-di-tert-butyl-4-hydroxy) benzoate; substituted oxalanilides such as 2-ethyl-2 '-ethoxyoxalanilide and 2-ethoxy-4' -dodecyloxalanilide; cyanoacrylates such as ethyl- α -cyano- β, β -diphenylacrylate and methyl-2-cyano-3-methyl-3- (p-methoxyphenyl) acrylate; various metal salts or metal chelates, especially salts or chelates of nickel and chromium.

Examples of the hindered amine compound include: 2,2,6, 6-tetramethyl-4-piperidyl stearate, 1,2,2,6, 6-pentamethyl-4-piperidyl stearate, 2,2,6, 6-tetramethyl-4-piperidyl benzoate, bis (2,2,6, 6-tetramethyl-4-piperidyl) sebacate, tetrakis (2,2,6, 6-tetramethyl-4-piperidyl) -1, 2,3, 4-butane tetraformate, tetrakis (1,2,2,6, 6-pentamethyl-4-piperidyl) -1, 2,3, 4-butane tetraformate, bis (2,2,6, 6-tetramethyl-4-piperidyl) -ditridecyl-1, 2,3, 4-butane tetraformate, bis (1,2,2,6, 6-pentamethyl-4-piperidyl) -ditridecyl-1, 2,3, 4-butane tetraformate, bis (1,2, 3, 4-butane tetraformate, a, Bis (1,2,2,4, 4-pentamethyl-4-piperidinyl) -2-butyl-2- (3, 5-di-tert-butyl-4-hydroxybenzyl) malonate, 1- (2-hydroxyethyl) -2, 2,6, 6-tetramethyl-4-piperidinol/diethyl succinate polycondensate, 1, 6-bis (2,2,6, 6-tetramethyl-4-piperidinylamino) hexane/2, 4-dichloro-6-morpholino-s-triazine polycondensate, 1, 6-bis (2,2,6, 6-tetramethyl-4-piperidinylamino) hexane/2, 4-dichloro-6-tert-octylamino-s-triazine polycondensate, 1,5,8, 12-tetrakis [2, 4-bis (N-butyl-N- (2,2,6, 6-tetramethyl-4-piperidinylamino) s-triazin-6-yl ] -1, 5,8, 12-tetraazadodecane, 1,5,8, 12-tetrakis [2, 4-bis (N-butyl-N- (1,2,2,6, 6-pentamethyl-4-piperidyl) amino) s-triazin-6-yl ] -1, 5,8, 12-tetraazadodecane, 1,6, 11-tris [2, 4-bis (N-butyl-N- (2,2,6, 6-tetramethyl-4-piperidyl) amino) s-triazin-6-yl ] aminoundecane, 1,6, 11-tris [2, 4-bis (N-butyl-N- (1,2,2,6, 6-pentamethyl-4-piperidyl) amino) s-triazin-6-yl ] aminoundecane, bis { 4- (1-octyloxy-2, 2,6, 6-tetramethyl) piperidyl } sebacate, bis { 4- (2,2,6, 6-tetramethyl-1-undecyloxy) piperidyl) carbonate and the like. Among these, preferred is a compound in which the group bonded to the 1-position of piperidine is an N-oxyalkyl group or an N-methyl group.

When the heat-sealable resin layer 4 contains a light stabilizer, the content is not particularly limited, and the heat-sealable resin layer 4 contains an amide-based lubricant and an antioxidant, and is preferably about 100 to 2000ppm, more preferably about 300 to 1500ppm, from the viewpoint of achieving an absorption spectrum intensity ratio X suitable for moldability and continuous productivity.

Examples of the nucleating agent include: carboxylic acid metal salts such as sodium benzoate, aluminum 4-tert-butylbenzoate, sodium adipate, disodium bicyclo [2.2.1] heptane-2, 3-dicarboxylate; phosphate metal salts such as sodium bis (4-tert-butylphenyl) phosphate, sodium 2,2 '-methylenebis (4, 6-di-tert-butylphenyl) phosphate and lithium 2, 2' -methylenebis (4, 6-di-tert-butylphenyl) phosphate; polyhydric alcohol derivatives such as dibenzylidene sorbitol, bis (methylbenzylidene) sorbitol, bis (p-ethylbenzylidene) sorbitol and bis (dimethylbenzylidene) sorbitol; amide compounds such as N, N ' -tris [ 2-methylcyclohexyl ] -1, 2, 3-propanetriamide (RIKACLEAR PC1), N ' -tricyclohexyl-1, 3, 5-benzenetricarbamide, N ' -dicyclohexyl-naphthalenedicarboxamide, and 1,3, 5-tris (dimethylisopropylamido) benzene.

When the heat-fusible resin layer 4 contains a nucleating agent, the content is not particularly limited, and the content is preferably about 100 to 2000ppm, more preferably about 300 to 1500ppm, from the viewpoint of achieving an absorption spectrum intensity ratio X suitable for moldability and continuous productivity, because the nucleating agent is contained in the heat-fusible resin layer 4 together with the amide-based lubricant and the antioxidant.

The heat-sealable resin layer 4 may further contain at least 1 other additive selected from a plasticizer, a flame retardant, and the like, from the viewpoint of suitably improving moldability and continuous productivity of the battery packaging material. The other additives may be used alone in 1 kind, or 2 or more kinds may be used in combination. The details of the mechanism are not clear, but it is considered that the amide-based lubricant is effectively inhibited from exuding to the surface of the heat-fusible resin layer 4 in a large amount by the interaction between the amide group of the amide-based lubricant and a functional group that generates a hydrogen bond such as a hydroxyl group, a carbonyl group, or a carboxyl group contained in the plasticizer or the flame retardant, or another substance that initiates an intermolecular interaction.

Examples of the plasticizer include commercially available plasticizers and rubber softeners added to polyvinyl chloride, polyethylene, natural rubber, and the like. Specifically, for example, there may be mentioned: phthalate or mixed phthalate plasticizers such as dibutyl phthalate, diheptyl phthalate, dioctyl phthalate, dinonyl phthalate, diisodecyl phthalate, dicyclohexyl phthalate, and the like; aliphatic dibasic acid ester plasticizers such as diisodecyl succinate, dioctyl adipate and dioctyl sebacate; glycol ester plasticizers such as diethylene glycol dibenzoate and dipentaerythritol hexaester; fatty acid ester plasticizers such as butyl oleate and methyl acetylricinoleate; phosphate plasticizers such as tricresyl phosphate and trioctyl phosphate; epoxy plasticizers such as epoxidized soybean oil, butyl epoxystearate and octyl epoxystearate, plasticizers such as paraffin wax, chlorinated paraffin wax and polytrimethylene adipate, and softeners for rubber such as paraffinic, naphthenic and aromatic mineral oils.

When the heat-fusible resin layer 4 contains a plasticizer, the content thereof is not particularly limited, and the heat-fusible resin layer 4 contains an amide-based lubricant and an antioxidant, and is preferably about 100 to 2000ppm, more preferably about 300 to 1500ppm, from the viewpoint of achieving an absorption spectrum intensity ratio X suitable for moldability and continuous productivity.

Examples of the flame retardant include: aromatic phosphates such as triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyldiphenyl-2, 6-xylenyl phosphate and resorcinol bis (diphenyl phosphate); phosphonates such as divinyl phenylphosphonate, diallyl phenylphosphonate, and (1-butenyl) phenylphosphonate; phosphinates such as phenyl diphenylphosphinate, methyl diphenylphosphinate, 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide derivatives and the like; phosphazene compounds such as bis (2-allylphenoxy) phosphazene and xylylphosphazene; phosphorus flame retardants such as melamine phosphate, melamine pyrophosphate, melamine polyphosphate, melam polyphosphate, ammonium polyphosphate, phosphorus-containing vinylbenzyl compounds, and red phosphorus; metal hydroxides such as magnesium hydroxide and aluminum hydroxide; brominated bisphenol a type epoxy resins, brominated novolac type epoxy resins, hexabromobenzene, pentabromotoluene, ethylenebis (pentabromophenyl), ethylenebistetrabromophthalimide, 1, 2-dibromo-4- (1, 2-dibromoethyl) cyclohexane, tetrabromocyclooctane, hexabromocyclododecane, bis (tribromophenoxy) ethane, brominated polyphenylene oxide, brominated polystyrene, and

brominated

2,4, 6-tris (tribromophenoxy) -1, 3, 5-triazine, tribromophenylmaleimide, tribromophenyl acrylate, tribromophenyl methacrylate, tetrabromobisphenol a type dimethacrylate, pentabromobenzyl acrylate, and brominated styrene.

When the heat-fusible resin layer 4 contains a flame retardant, the content is not particularly limited, and the heat-fusible resin layer 4 contains the flame retardant together with an amide-based lubricant and an antioxidant, and is preferably about 100 to 2000ppm, more preferably about 300 to 1500ppm, from the viewpoint of achieving an absorption spectrum intensity ratio X suitable for moldability and continuous productivity.

In the battery packaging material of the present invention, the wave number of C ═ O stretching vibration of the amide group of the amide lubricant was measured by an absorption spectrum obtained by dispersing reflected light when infrared rays were irradiated to the surface of heat-fusible resin layer 4, and the wave number of 1650cm was measured^-1and-CH derived from the heat-fusible resin layer₂Wave number of variable angle vibration 1460cm^-1The absorption peak intensity ratio X of the absorption peak intensity A to the absorption peak intensity B calculated from the absorption peak intensity B is in the range of 0.05 to 0.80. More specifically, when an infrared absorption spectrum is obtained from the outermost surface side by attenuated total reflection method of fourier transform infrared spectroscopy, the wave number of C ═ O stretching vibration of the amide group of the amide lubricant is measured at 1650cm^-1and-CH derived from the heat-fusible resin layer₂Wave number of variable angle vibration 1460cm^-1The absorption peak intensity ratio X of the absorption peak intensity A to the absorption peak intensity B calculated from the absorption peak intensity B is in the range of 0.05 to 0.80. By having such a specific range of the absorption spectrum intensity ratio X, the packaging material for a battery of the present invention has high moldability and is excellent in the continuous productivity of the battery. In the present invention, the absorption spectrum intensity ratio X may be in the range of 0.05 to 0.80, and more preferable absorption spectrum intensity ratios X are about 0.10 to 0.70, about 0.10 to 0.60, about 0.20 to 0.70, and about 0.20 to 0.60.

Wherein the absorption spectrum intensity ratio X in the present invention is a value obtained as follows: the surface of the heat-sealable resin layer of the sample was measured by infrared absorption spectroscopy at a temperature of 25 ℃ and a relative humidity of 50% using an ATR mode of Nicolet iS10 FT-IR manufactured by Thermo Fisher Scientific corporation, and the sample was calculated by cutting the battery packaging material into a square shape of 100mm × 100 mm.

As described above, in conventional battery packaging materials, an amide-based lubricant is mixed into the heat-fusible resin layer, or the amide-based lubricant is coated on the heat-fusible resin layer. However, although the amide-based lubricant applied to the heat-sealable resin layer or the amide-based lubricant blended in the heat-sealable resin layer is set to a predetermined amount, the amide-based lubricant adheres to the mold during molding of the battery packaging material, and thus continuous productivity may be reduced, or cracks or pinholes may be generated in the battery packaging material. This is because, in either case of blending the amide-based lubricant in the heat-fusible resin layer or applying the amide-based lubricant on the heat-fusible resin layer, the amount of the amide-based lubricant on the surface of the heat-fusible resin layer greatly changes depending on the environment, particularly the temperature change, from the production of the battery packaging material to the molding in the storage environment, the transportation environment, and the like from the production of the battery packaging material to the molding. Therefore, even when the same amount of amide-based lubricant is used in the production of the battery packaging material, the amount of the amide-based lubricant on the surface during molding greatly changes depending on the storage environment and the like, and the amide-based lubricant adheres to the mold and deteriorates continuous productivity, or cracks or pinholes may occur in the battery packaging material. Further, if the environment, particularly the temperature change, from the production of the battery packaging material to the molding, such as the storage environment from the production of the battery packaging material to the molding, the transportation environment, etc., is appropriately managed, the change in the amount of the amide-based lubricant between the production of the battery packaging material and the molding can be suppressed.

In contrast, in the battery packaging material of the present invention, by containing at least 1 selected from the group consisting of an antioxidant, a light stabilizer and a nucleating agent together with the amide-based lubricant, the amount of the amide-based lubricant located on the surface of the heat-sealable resin layer 4 reaches the absorption spectrum intensity ratio X suitable for moldability and continuous productivity, and therefore, is suitable for battery production.

The thickness of the heat-fusible resin layer 4 is not particularly limited as long as it can function as a heat-fusible resin layer, and is preferably about 60 μm or less, more preferably about 15 to 40 μm.

[ adhesive layer 5]

In the battery packaging material of the present invention, the adhesive layer 5 is a layer provided between the barrier layer 3 and the heat-fusible resin layer 4 as necessary to firmly adhere them.

The adhesive layer 5 is formed of a resin capable of bonding the barrier layer 3 and the heat-fusible resin layer 4. As the resin for forming the adhesive layer 5, the same resin as the adhesive exemplified in the adhesive layer 2, such as the adhesion mechanism and the type of the adhesive component, can be used. As the resin for forming the adhesive layer 5, polyolefin resins such as polyolefin, cyclic polyolefin, carboxylic acid-modified polyolefin, and carboxylic acid-modified cyclic polyolefin exemplified in the above-described heat-sealable resin layer 4 can be used. The polyolefin is preferably a carboxylic acid-modified polyolefin, and particularly preferably a carboxylic acid-modified polypropylene, from the viewpoint of excellent adhesion between the barrier layer 3 and the heat-sealable resin layer 4.

Further, the adhesive layer 5 may be a cured product of a resin composition containing an acid-modified polyolefin and a curing agent, from the viewpoint of making the thickness of the battery packaging material thin and obtaining a battery packaging material excellent in shape stability after molding. The acid-modified polyolefin is preferably the same compound as the carboxylic acid-modified polyolefin and the carboxylic acid-modified cyclic polyolefin exemplified in the heat-sealable resin layer 4.

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

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

The polyfunctional isocyanate curing agent is not particularly limited as long as it is a compound having 2 or more isocyanate groups. Specific examples of the polyfunctional isocyanate curing agent include isophorone diisocyanate (IPDI), Hexamethylene Diisocyanate (HDI), Toluene Diisocyanate (TDI), diphenylmethane diisocyanate (MDI), products obtained by polymerizing or urethanizing these isocyanates, mixtures thereof, and copolymers with other polymers.

The carbodiimide-based curing agent is not particularly limited as long as it is a compound having at least 1 carbodiimide group (-N ═ C ═ N —). The carbodiimide-based curing agent is preferably a polycarbodiimide compound having at least 2 or more carbodiimide groups.

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

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

The content of the curing agent in the resin composition forming the adhesive layer 5 is preferably in the range of about 0.1 to 50 mass%, more preferably about 0.1 to 30 mass%, and still more preferably about 0.1 to 10 mass%.

The thickness of the adhesive layer 5 is not particularly limited as long as it can function as an adhesive layer, and when the adhesive exemplified in the adhesive layer 2 is used, it is preferably about 2 to 10 μm, more preferably about 2 to 5 μm. In addition, when the resin exemplified in the heat-fusible resin layer 4 is used, it is preferably about 2 to 50 μm, and more preferably about 10 to 40 μm. In the case of a cured product of an acid-modified polyolefin and a curing agent, the thickness is preferably about 30 μm or less, more preferably about 0.1 to 20 μm, and still more preferably about 0.5 to 5 μm. When the adhesive layer 5 is a cured product of a resin composition containing an acid-modified polyolefin and a curing agent, the adhesive layer 5 can be formed by applying the resin composition and curing the resin composition by heating or the like.

[ surface coating layer 6]

In the battery packaging material of the present invention, the surface-covering layer 6 may be provided on the base material layer 1 (on the side of the base material layer 1 opposite to the barrier layer 3) as necessary for the purpose of improving design properties, electrolyte resistance, scratch resistance, moldability, and the like. The surface coating layer 6 is a layer located at the outermost layer when the battery is assembled.

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

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

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

The thickness of the surface-covering layer 6 is not particularly limited as long as the above-described function as the surface-covering layer 6 can be exerted, and may be, for example, about 0.5 to 10 μm, preferably about 1 to 5 μm.

3. Method for producing battery packaging material

The method for producing the battery packaging material of the present invention is not particularly limited as long as a laminate obtained by laminating layers having a predetermined composition can be obtained. An example of the method for producing the battery packaging material of the present invention is as follows. First, a laminate (hereinafter, also referred to as "laminate a") in which a base material layer 1, an adhesive layer 2, and a barrier layer 3 are laminated in this order is formed. Specifically, the laminate a can be formed by a dry lamination method as follows: an adhesive for forming the adhesive layer 2 is applied on the substrate layer 1 or the barrier layer 3 whose surface is chemically treated as necessary by a coating method such as a gravure coating method or a roll coating method, and after drying, the barrier layer 3 or the substrate layer 1 is laminated and the adhesive layer 2 is cured.

Next, the adhesive layer 5 and the heat-fusible resin layer 4 are sequentially laminated on the barrier layer 3 of the laminate a. Examples of the method include the following: (1) a method of laminating the adhesive layer 5 and the heat-fusible resin layer 4 by coextrusion on the barrier layer 3 of the laminate a (coextrusion lamination method); (2) a method of forming a laminate in which the adhesive layer 5 and the heat-fusible resin layer 4 are laminated, and laminating the laminate on the barrier layer 3 of the laminate A by a heat lamination method; (3) a method in which an adhesive for forming the adhesive layer 5 is applied to the barrier layer 3 of the laminate a by an extrusion method or a solution, and then laminated by a method such as drying at a high temperature and baking, and the heat-fusible resin layer 4 previously formed into a sheet shape is laminated on the adhesive layer 5 by a heat lamination method; (4) a method (interlayer lamination method) in which the laminate a and the heat-fusible resin layer 4 are bonded to each other by the adhesive layer 5 while the molten adhesive layer 5 is poured between the barrier layer 3 of the laminate a and the heat-fusible resin layer 4 formed in a sheet shape in advance.

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

In this way, a laminate comprising the surface covering layer 6, if necessary, the base material layer 1, if necessary, the adhesive layer 2, if necessary, the barrier layer 3 having a chemically treated surface, if necessary, the adhesive layer 5, and the heat-fusible resin layer 4 is formed, but the laminate may be subjected to heat treatment such as a heat roller contact type, a hot air type, a near infrared ray type, or a far infrared ray type in order to enhance the adhesiveness of the adhesive layer 2 or the adhesive layer 5. Examples of the conditions for such heat treatment include heating at 150 to 250 ℃ for 1 to 5 minutes.

In the battery packaging material of the present invention, each layer constituting the laminate may be subjected to surface activation treatment such as corona treatment, sand blasting, oxidation treatment, ozone treatment, or the like as necessary, in order to improve or stabilize film formability, lamination processing, 2-pass processing (bag making, embossing) suitability of the final product, or the like.

In the method for producing a battery packaging material of the present invention, after the battery packaging material thus laminated is prepared, a step of confirming that the absorption spectrum intensity ratio X is in the range of 0.05 to 0.80 (more specifically, when an infrared absorption spectrum is obtained from the outermost surface side of the heat-sealable resin layer by attenuated total reflection method of fourier transform infrared spectroscopy, the absorption spectrum intensity ratio X is in the range of 0.05 to 0.80 by the method for measuring and calculating the absorption spectrum intensity ratio X is in the range of 0.05 to 0.80) is performed by a method for measuring and a method for calculating the absorption spectrum intensity ratio X, whereby the battery packaging material of the present invention having high moldability and excellent continuous productivity of batteries can be produced.

4. Use of packaging material for battery

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

Specifically, the battery packaging material of the present invention covers a battery element having at least a positive electrode, a negative electrode, and an electrolyte so that flange portions (regions where heat-fusible resin layers are in contact with each other) can be formed on the outer peripheral edge of the battery element in a state where metal terminals connected to the positive electrode and the negative electrode are protruded outward, and heat-seals the heat-fusible resin layers of the flange portions, thereby providing a battery using the battery packaging material. When a battery element is contained in a package formed of the battery packaging material of the present invention, the package is formed such that the heat-fusible resin portion of the battery packaging material of the present invention is on the inside (the surface in contact with the battery element).

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

Examples

The present invention will be described in detail below by way of examples and comparative examples. However, the present invention is not limited to the examples.

Examples 1 to 10 and comparative examples 1 to 9

< production of packaging Material for Battery >

By the dry lamination method, barrier layers each composed of an aluminum foil (JIS H4000: 2014A 8021P-O, thickness 40 μm) chemically surface-treated on both sides were laminated on a base layer (thickness 25 μm for a single layer) composed of the resins described in Table 1. Specifically, a two-pack type polyurethane adhesive (a polyol compound and an aromatic isocyanate compound) was applied to one surface of an aluminum foil, and the aluminum foil was coated with the two-pack type polyurethane adhesiveAn adhesive layer (thickness: 3 μm) was formed on the barrier layer. Next, the adhesive layer on the barrier layer and the base layer are laminated, and then subjected to a curing treatment to produce a laminate of the base layer/the adhesive layer/the barrier layer. Wherein the chemical surface treatment of the aluminum foil used as the barrier layer is performed by: the chromium coating amount on both sides of the aluminum foil was 10mg/m by roll coating²(dry mass) a treatment liquid composed of a phenol resin, a chromium fluoride compound and phosphoric acid was applied and baked.

In table 1, Ny represents nylon, PET represents polyethylene terephthalate, PBT represents polybutylene terephthalate, AL represents aluminum alloy, SUS represents stainless steel, PPa represents maleic anhydride-modified polypropylene, PP represents atactic polypropylene, and PE represents high-density polyethylene. The PET/Ny used as the base layer was a laminate of a PET film (12 μm) and a Ny film (15 μm) (the PET film and the Ny film were bonded with a 3 μm two-liquid polyurethane adhesive), and the PET was located on the outermost layer side.

Next, on the barrier layer of the laminate, an adhesive layer (thickness 23 μm, disposed on the barrier layer side) formed of the resin described in table 1 and a heat-fusible resin layer (thickness 23 μm, innermost layer) formed of the resin described in table 1 containing additives a to C and a lubricant (erucamide was 1400ppm) described below were co-extruded, thereby laminating an adhesive layer/heat-fusible resin layer on the barrier layer. Next, the obtained laminate was cured and finally heated to obtain a battery packaging material in which a base material layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were sequentially laminated.

Details of the antioxidant, light stabilizer and nucleating agent are as follows.

Additive A: phenol antioxidant (ADEKA STAB AO-20 available from ADEKA Co., Ltd.)

And (3) an additive B: hindered amine light stabilizer (ADEKA STAB LA-57 manufactured by ADEKA Co., Ltd.)

And (3) an additive C: nucleating agent (ADEKA STAB NA-11 manufactured by ADEKA corporation)

(measurement of Infrared absorption Spectrum by Infrared Spectroscopy)

The obtained packaging material for batteries was cut into a square shape of 100mm × 100mm to prepare a sample. The surface of the sealing layer of this sample was subjected to infrared absorption spectrometry using an ATR mode of Nicolet iS10 FT-IR manufactured by Thermo Fisher Scientific, under an environment of a temperature of 25 ℃ and a relative humidity of 50%. From the obtained absorption spectrum, the wave number of C ═ O stretching vibration derived from the amide group was measured at 1650cm^-1Absorption peak intensity of A and from-CH₂Wave number of variable angle vibration 1460cm^-1And calculating an absorption spectrum intensity ratio X of the absorption peak intensity a to the absorption peak intensity B as a/B. The results are shown in Table 1.

(conditions for measuring Infrared absorption Spectrum)

The method comprises the following steps: macro-ATR method

A detector: TGS

Wave number resolution: 4cm^-1

And (4) accumulating times: 32 times (twice)

Prism: germanium (Ge)

Baseline: wave number 1900cm^-1To 2000cm^-1Average value of intensity in the range of (1)

Absorption peak intensity a: from 1635cm wave number^-1To 1665cm^-1A value obtained by subtracting the value of the base line from the maximum value of the absorption peak intensity in the range of (1)

Absorption peak intensity B: from 1435cm of wavenumber^-1To 1475cm^-1A value obtained by subtracting the value of the base line from the maximum value of the absorption peak intensity in the range of (1)

(evaluation of moldability)

The obtained packaging material for batteries was cut into a square of 80mm × 120mm to prepare a sample. For this sample, using a forming die having a diameter of 30 × 50mm (female die, JIS B0659-1: 2002 attached document 1 (reference) on the surface) and a forming die corresponding thereto (male die, JIS B0659-1: 2002 attached document 1 (reference) and a maximum height roughness (nominal value of Rz) specified in table 2 of the surface roughness standard sheet were compared and 1.6 μm on the surface roughness standard sheet), the forming depth was changed in units of 0.5mm from the forming depth of 0.5mm, and 10 samples were cold-rolled at a pressing pressure of 0.4MPa, respectively. For the samples after cold rolling forming, the deepest forming depth at which wrinkles are not generated and pinholes and cracks are not generated in the aluminum foil is set as the limit forming depth of the samples in all 10 samples. From the limit molding depth, the moldability of the battery packaging material was evaluated according to the following criteria. The results are shown in Table 1.

5: the limit forming depth is more than 6.0mm

4: the limit forming depth is more than 5.5mm and less than 6.0mm

3: the limit forming depth is more than 5.0mm and less than 5.5mm

2: the limit forming depth is more than 4.5mm and less than 5.0mm

1: the limit forming depth is more than 4.0mm and less than 4.5mm

0: the limit forming depth is less than 3.5mm

(evaluation of continuous productivity of Battery)

The corners of the mold after the above-described evaluation of moldability were visually observed, and the case where the lubricant was transferred to the mold and whitened was evaluated as poor continuous moldability (evaluation C), the case where no whitening was generated was evaluated as very high continuous moldability (evaluation a), and the case where the lubricant was transferred to the mold but slightly whitened was evaluated as high continuous productivity (evaluation B). The results are shown in Table 1.

[ Table 1]

Description of the symbols

1: a substrate layer; 2: an adhesive layer; 3: a barrier layer; 4: a heat-fusible resin layer; 5: an adhesive layer; 6: and (5) covering the surface.

Claims

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

which comprises a laminate comprising at least a substrate layer, a barrier layer and a heat-sealable resin layer in this order,

the heat-sealable resin layer contains at least 1 selected from an antioxidant, a light stabilizer and a nucleating agent, and an amide-based lubricant,

the wave number of C ═ O stretching vibration of the amide group of the amide lubricant was determined at 1650cm in terms of the wave number from the absorption spectrum obtained by splitting the reflected light when infrared light was irradiated to the surface of the heat-fusible resin layer^-1and-CH contained in the thermally adhesive resin layer₂Wave number of variable angle vibration 1460cm^-1The absorption peak intensity A calculated from the absorption peak intensity B is in a range of 0.05 to 0.80 in terms of absorption spectrum intensity ratio X A/B,

the content of at least 1 selected from the antioxidant, the light stabilizer and the nucleating agent contained in the heat-sealable resin layer is 100ppm to 2000 ppm.

2. The packaging material for batteries according to claim 1, wherein:

the antioxidant is at least 1 selected from phenolic antioxidant, phosphorus antioxidant and thioether antioxidant,

3. The packaging material for batteries according to claim 1 or 2, wherein:

the heat-fusible resin layer further contains a plasticizer.

4. The packaging material for batteries according to claim 1 or 2, wherein:

the heat-fusible resin layer further contains a flame retardant.

5. The packaging material for batteries according to claim 1 or 2, wherein:

the heat-fusible resin layer contains polyolefin.

6. A battery, characterized by:

a battery element having at least a positive electrode, a negative electrode and an electrolyte is housed in a package formed of the battery packaging material according to any one of claims 1 to 5.

7. A method for manufacturing a battery packaging material, comprising:

a step of preparing a battery packaging material comprising a laminate in which at least a base material layer, a barrier layer, and a heat-sealable resin layer containing at least 1 selected from the group consisting of an antioxidant, a light stabilizer, and a nucleating agent, and an amide lubricant are laminated in this order; and

from the absorption spectrum obtained by splitting the reflected light when infrared light was irradiated onto the surface of the heat-fusible resin layer, it was confirmed that the wave number of C ═ O stretching vibration obtained by measuring the amide group of the amide lubricant was 1650cm^-1and-CH contained in the heat-sealable resin layer₂Wave number of variable angle vibration 1460cm^-1A step of calculating an absorption spectrum intensity ratio X of the absorption peak intensity A to the absorption peak intensity B, which is a ratio of A/B of 0.05 to 0.80,