JP6589331B2 - Battery packaging materials - Google Patents

Description

  The present invention relates to a battery packaging material in which deterioration due to moisture is suppressed.

  Conventionally, various types of batteries have been developed. In any battery, a packaging material is an indispensable member for sealing battery elements such as electrodes and electrolytes. Conventionally, metal packaging materials have been widely used as battery packaging, but in recent years, with the increasing performance of electric vehicles, hybrid electric vehicles, personal computers, cameras, mobile phones, etc., batteries are required to have various shapes. At the same time, there is a demand for reduction in thickness and weight. However, metal battery packaging materials that have been widely used in the past have the disadvantages that it is difficult to follow the diversification of shapes and that there is a limit to weight reduction.

  Therefore, a film-like laminate in which a base material layer / adhesive layer / metal layer / sealant layer are sequentially laminated is proposed as a battery packaging material that can be easily processed into various shapes and can be made thinner and lighter. (For example, refer to Patent Document 1). Such a film-shaped battery packaging material is formed so that the battery element can be sealed by causing the sealant layers to face each other and heat-sealing the peripheral portion by heat sealing.

  By the way, the environment in which the battery is used varies widely, and the battery packaging material may be exposed to a high-temperature and high-humidity environment. For this reason, in the battery packaging material formed by the film-like laminate as described above, the migration of moisture from the external environment to the battery element is suppressed by the metal layer contained in the laminate.

JP 2008-287971 A

However, the present inventors have examined that when the battery packaging material formed by the film-like laminate as described above is exposed to a high temperature and humidity environment for a long period of time, the base material layer and the metal It has been revealed that the adhesive layer adhering to the layer may deteriorate due to moisture. When the adhesive layer is deteriorated, there is a problem that a laminate strength between the base material layer and the metal layer is lowered, and a phenomenon called delamination occurs in which the base material layer and the metal layer are separated. Further, when the adhesive layer is deteriorated, the adhesive layer is yellowed, and there is a problem that an appearance defect is caused in the battery packaging material.
An object of the present invention is to provide a battery packaging material in which deterioration due to moisture is effectively suppressed.

  The present inventors have intensively studied to solve the above problems. As a result, in the battery packaging material comprising at least the base material layer, the adhesive layer, the metal layer, and the sealant layer in this order, by laminating the moisture barrier layer on the base material layer side of the adhesive layer Even when battery packaging materials are exposed to high temperature and humidity for a long period of time, deterioration of the adhesive layer due to moisture is suppressed, and delamination between the base material layer and the metal layer and yellowing of the adhesive layer are prevented. It was found that it was effectively suppressed. The present invention has been completed by further studies based on such knowledge.

That is, this invention provides the invention of the aspect hung up below.
Item 1. It consists of a laminate having at least a base material layer, an adhesive layer, a metal layer, and a sealant layer in this order,
A battery packaging material in which a moisture barrier layer is laminated on the substrate layer side of the adhesive layer.
Item 2. Item 2. The battery packaging material according to Item 1, wherein the moisture barrier layer is laminated between the base material layer and the adhesive layer.
Item 3. Item 3. The battery packaging material according to Item 1 or 2, wherein the moisture barrier layer is laminated on the outside of the base material layer.
Item 4. Item 4. The battery packaging material according to any one of Items 1 to 3, wherein the moisture barrier layer includes a metal or metal oxide thin film layer.
Item 5. Item 5. The battery packaging material according to Item 4, wherein the moisture barrier layer is a laminate of the thin film layer and the resin layer.
Item 6. Item 6. The battery packaging material according to any one of Items 1 to 5, wherein the adhesive layer is formed of a polyurethane-based adhesive.
Item 7. After the battery packaging material is stored for 1900 hours in an environment of a temperature of 80 ° C. and a humidity of 95% RH, the laminate strength between the base material layer and the metal layer is 2.0 N / 15 mm or more, and
Before and after the storage, the difference between b ^* values of the L ^* a ^* b ^* color system was measured from the base layer side ([Delta] b ^*) is 1.0 or less, according to any one of claim 1 to 6 Battery packaging material.
Item 8. Claim | item 1-7 whose moisture permeation amount measured based on the Mokon method of JISK7129B of the laminated body of the said base material layer and the said water | moisture-content barrier layer is 8 g / m < ² > * day or less. Battery packaging material.
Item 9. Item 9. A battery in which a battery element including at least a positive electrode, a negative electrode, and an electrolyte is accommodated in the battery packaging material according to any one of Items 1 to 8.

  According to the present invention, in a battery packaging material comprising a laminate having at least a base material layer, an adhesive layer, a metal layer, and a sealant layer in this order, the moisture barrier layer is laminated on the base material layer side of the adhesive layer. Thus, even when the battery packaging material is exposed to a high temperature and humidity environment for a long period of time, the deterioration of the adhesive layer due to moisture is suppressed, and the delamination between the base material layer and the metal layer and the adhesive layer A battery packaging material in which yellowing is effectively suppressed can be provided. Moreover, according to this invention, the battery using the said packaging material for batteries can be provided.

It is a schematic sectional drawing of the packaging material for batteries of this invention. It is a schematic sectional drawing of the packaging material for batteries of this invention. It is a schematic sectional drawing of the packaging material for batteries of this invention. It is a schematic sectional drawing of the packaging material for batteries of this invention. It is a schematic sectional drawing of the packaging material for batteries of this invention.

1. Battery packaging material The battery packaging material of the present invention comprises at least a base material layer, an adhesive layer, a metal layer, and a sealant layer in this order, and a moisture barrier layer on the base material layer side of the adhesive layer. Are laminated. Hereinafter, the battery packaging material of the present invention will be described in detail.

As shown in FIGS. 1 to 5, the battery packaging material laminate structure and physical properties battery packaging material is a laminate having at least a base material layer 1, an adhesive layer 2, a metal layer 3, and a sealant layer 4 in this order. Furthermore, the moisture barrier layer 5 is laminated on the base material layer 1 side with respect to the adhesive layer 2. In the battery packaging material of the present invention, the base material layer 1 side is the outer layer, and the sealant layer 4 is the innermost layer. When assembling the battery, the sealant layers 4 located on the periphery of the battery element are brought into contact with each other and thermally welded to seal the battery element and seal the battery element. As shown in FIG. 2, the battery packaging material of the present invention may have an adhesive layer 6 between the metal layer 3 and the sealant layer 4.

  1-2, the water | moisture-content barrier layer 5 may be comprised by one layer, and may be comprised by multiple layers as FIG. 3-5 shows. As will be described later, when the moisture barrier layer 5 is composed of one layer, the moisture barrier layer 5 is preferably formed of a thin film layer 51 of metal or metal oxide (see FIGS. 1 and 2). ). Moreover, when the moisture barrier layer 5 is comprised by multiple layers, it is preferable that the moisture barrier layer 5 is a laminated body of the thin film layer 51 and the resin layer 52 (refer FIGS. 3-5).

  When the moisture barrier layer 5 is a laminate of the thin film layer 51 and the resin layer 52, the stacking order of the thin film layer 51 and the resin layer 52 is not particularly limited (see, for example, FIGS. 3 and 4). As shown in FIG. 5, when the moisture barrier layer 5 is located on the outermost layer, it is desirable that the thin film layer 51 is not exposed on the outermost surface.

The battery packaging material of the present invention has a laminate strength of the base material layer 1 and the metal layer 3 of 2: 1 after storing the battery packaging material in an environment of a temperature of 80 ° C. and a humidity of 95% RH for 1900 hours. and at 0N / 15 mm or more, and, before and after storage, that the difference between b ^* values of the L ^* a ^* b ^* color system was measured from the base material layer 1 side ([Delta] b ^*) it is 1.0 or less preferable. In the battery packaging material of the present invention, since the moisture barrier layer 5 is laminated on the base material layer 1 side with respect to the adhesive layer 2, it is possible to preferably exhibit such physical properties.

The laminate strength is preferably 2.5 N / 15 mm or more. Moreover, as said (DELTA ⁾ b ^* , Preferably 0.5 or less is mentioned.

The laminate strength of the base material layer 1 and the metal layer 3 is specifically a value measured by the method described in the examples. Also, Δb ^* is specifically a value measured by the method described in the examples.

Composition of each layer forming base material for battery [base material layer 1]
In the battery packaging material of the present invention, the base material layer 1 is a layer located outside the metal layer 3. The material for forming the base material layer 1 is not particularly limited as long as it has insulating properties. Examples of the material for forming the base material layer 1 include polyester, polyamide, epoxy, acrylic, fluororesin, polyurethane, silicon resin, phenol, polyetherimide, polyimide, and a mixture or copolymer thereof.

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

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

  The base material layer 1 may be formed of a uniaxially or biaxially stretched resin film, or may be formed of an unstretched resin film. Among them, a uniaxially or biaxially stretched resin film, in particular, a biaxially stretched resin film has improved heat resistance by orientation crystallization, and thus is suitably used as the base material layer 1. Moreover, the base material layer 1 may be formed by coating the above-mentioned raw material on the metal layer 3.

  Among these, as a resin film which forms the base material layer 1, Preferably nylon and polyester, More preferably, biaxially stretched nylon, biaxially stretched polyester, Most preferably, biaxially stretched nylon is mentioned.

  The base material layer 1 can also be laminated with at least one of resin films and coatings of different materials in order to improve pinhole resistance and insulation when used as a battery package. Specific examples include a multilayer structure in which a polyester film and a nylon film are laminated, and a multilayer structure in which a biaxially stretched polyester and a biaxially stretched nylon are laminated. When making the base material layer 1 into a multilayer structure, each resin film may be adhere | attached through an adhesive agent, and may be laminated | stacked directly without an adhesive agent. In the case of bonding without using an adhesive, for example, a method of bonding in a hot melt state such as a co-extrusion method, a sand lamination method, or a thermal laminating method can be mentioned. Moreover, when making it adhere | attach through an adhesive agent, the adhesive agent to be used may be a two-component curable adhesive, or a one-component curable adhesive. Further, the bonding mechanism of the adhesive is not particularly limited, and may be any of a chemical reaction type, a solvent volatilization type, a heat melting type, a hot pressure type, an electron beam curing type such as UV and EB, and the like. As an adhesive component, polyester resin, polyether resin, polyurethane resin, epoxy resin, phenol resin resin, polyamide resin, polyolefin resin, polyvinyl acetate resin, cellulose resin, (meth) acrylic resin Resins, polyimide resins, amino resins, rubbers, and silicon resins can be used.

  The base material layer 1 may be reduced in friction in order to improve moldability. When reducing the friction of the base material layer 1, the coefficient of friction of the surface is not particularly limited, but for example, 1.0 or less can be mentioned. In order to reduce the friction of the base material layer 1, for example, mat treatment, formation of a thin film layer of a slip agent, a combination thereof, and the like can be given.

  As the matting treatment, a matting agent is added to the base material layer 1 in advance to form irregularities on the surface, a transfer method by heating or pressurizing with an embossing roll, a surface is mechanically dry or wet blasting or filed. The method of ruining is mentioned. Examples of the matting agent include fine particles having a particle size of about 0.5 nm to 5 μm. The material of the matting agent is not particularly limited, and examples thereof include metals, metal oxides, inorganic substances, and organic substances. The shape of the matting agent is not particularly limited, and examples thereof include a spherical shape, a fiber shape, a plate shape, an indeterminate shape, and a balloon shape. Specific examples of the matting agent include talc, silica, graphite, kaolin, montmorilloid, montmorillonite, synthetic mica, hydrotalcite, silica gel, zeolite, aluminum hydroxide, magnesium hydroxide, zinc oxide, magnesium oxide, and oxidation. Aluminum, neodymium oxide, antimony oxide, titanium oxide, cerium oxide, calcium sulfate, barium sulfate, calcium carbonate, calcium silicate, lithium carbonate, calcium benzoate, calcium oxalate, magnesium stearate, alumina, carbon black, carbon nanotubes , High melting point nylon, crosslinked acrylic, crosslinked styrene, crosslinked polyethylene, benzoguanamine, gold, aluminum, copper, nickel and the like. These matting agents may be used individually by 1 type, and may be used in combination of 2 or more type. Among these matting agents, silica, barium sulfate, and titanium oxide are preferable from the viewpoint of dispersion stability and cost. The matting agent may be subjected to various surface treatments such as insulation treatment and high dispersibility treatment on the surface.

  The slip agent thin film layer can be formed by depositing a slip agent on the surface of the base material layer 1 by bleeding out to form a thin layer, or by laminating the slip agent on the base material layer 1. The slip agent is not particularly limited. For example, fatty acid amide, metal soap, hydrophilic silicone, silicone grafted acrylic, silicone grafted epoxy, silicone grafted polyether, silicone grafted polyester, block type silicone Examples thereof include acrylic copolymers, polyglycerol-modified silicone, and paraffin. These slip agents may be used individually by 1 type, and may be used in combination of 2 or more type.

  As for the thickness of the base material layer 1, 10-50 micrometers is mentioned, for example, Preferably 15-30 micrometers is mentioned.

[Adhesive layer 2]
In the battery packaging material of the present invention, the adhesive layer 2 is a layer provided for the purpose of enhancing the adhesion between the base material layer 1 and the metal layer 3.

  The adhesive layer 2 is formed of an adhesive capable of bonding the base material layer 1 or the moisture barrier layer 5 and the metal layer 3. The adhesive used for forming the adhesive layer 2 may be a two-component curable adhesive or a one-component curable adhesive. Furthermore, the adhesive mechanism of the adhesive used for forming the adhesive layer 2 is not particularly limited, and may be any of a chemical reaction type, a solvent volatilization type, a heat melting type, a hot pressure type, and the like.

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

  As described above, when the battery packaging material is exposed to a high-temperature and high-humidity environment for a long period of time, the adhesive layer that bonds the base material layer and the metal layer may deteriorate due to moisture. In particular, a polyurethane adhesive preferable as an adhesive constituting the adhesive layer is likely to cause such a problem of deterioration. On the other hand, in the battery packaging material of the present invention, the above-mentioned moisture barrier layer 5 is laminated on the base material layer 1 side with respect to the adhesive layer 2, so that the battery packaging material is in a high-temperature and high-humidity environment. Even when exposed to a long period of time, deterioration of the adhesive layer 2 due to moisture is suppressed. Therefore, the laminate strength between the base material layer 1 and the metal layer 3 is hardly lowered, the occurrence of delamination is effectively suppressed, and the yellowing of the adhesive layer 2 is also effectively suppressed.

  The adhesive layer 2 may be multilayered with different adhesive components. When the adhesive layer 2 is multilayered with different adhesive components, from the viewpoint of improving the laminate strength between the base material layer 1 and the metal layer 3, the adhesive component disposed on the base material layer 1 side is used as the base material layer 1. Alternatively, it is preferable to select a resin excellent in adhesiveness with the moisture barrier layer 5 and select an adhesive component excellent in adhesiveness with the metal layer 3 as an adhesive component disposed on the metal layer 3 side. When the adhesive layer 2 is multilayered with different adhesive components, specifically, the adhesive component disposed on the metal layer 3 side is preferably an acid-modified polyolefin, a metal-modified polyolefin, a polyester and an acid-modified polyolefin. And a resin containing a copolyester.

  About the thickness of the contact bonding layer 2, 2-50 micrometers, for example, Preferably 3-25 micrometers is mentioned.

[Moisture barrier layer 5]
In the battery packaging material of the present invention, the moisture barrier layer 5 is laminated on the base material layer 1 side with respect to the adhesive layer 2, and is a layer provided to suppress the permeation of moisture from the base material layer 1 side. is there.

  As described above, the moisture barrier layer 5 may be composed of one layer or a plurality of layers. When the moisture barrier layer 5 is composed of one layer, the moisture barrier layer 5 is preferably formed of a thin film layer 51 of metal or metal oxide. When the moisture barrier layer 5 is composed of a plurality of layers, the moisture barrier layer 5 is preferably a laminate of the thin film layer 51 and the resin layer 52. Further, when the moisture barrier layer 5 is a laminate of the thin film layer 51 and the resin layer 52, the stacking order of the thin film layer 51 and the resin layer 52 in the battery packaging material is not particularly limited (for example, FIG. 3 and FIG. 3). (See FIG. 4). As shown in FIG. 5, when the moisture barrier layer 5 is located on the outermost layer, it is desirable that the thin film layer 51 is not located on the outermost surface of the battery packaging material.

  As described above, when the base material layer 1 has a multilayer structure and each resin film is bonded via an adhesive, the adhesive layer is prevented from being deteriorated by moisture. As shown in FIG. 5, the moisture barrier layer 5 is preferably laminated on the outside of the base material layer 1.

  Although it does not restrict | limit especially as a metal and metal oxide which comprise the thin film layer 51, Since moisture permeability is low, Preferably, metals, such as aluminum; Metal oxides, such as an alumina and a silica, are mentioned. The thin film layer 51 may be a single layer of these, or may be a stack of a plurality of these deposited films.

  For example, when the moisture barrier layer 5 is formed of a single layer of the thin film layer 51, the thin film layer 51 can be laminated by, for example, depositing a metal or a metal oxide on the surface of the base material layer 1. . Further, when the moisture barrier layer 5 is formed of a plurality of layers and is a laminate of the thin film layer 51 and the resin layer 52, the thin film layer 51 is formed on the surface of the resin layer 52 with a metal or metal oxide, for example. It can be laminated by depositing an object. In addition, the laminated body of the thin film layer 51 and the resin layer 52 can obtain a commercial item easily.

  As resin which comprises the resin layer 52, the same thing as resin illustrated by the above-mentioned base material layer 1 can be illustrated.

  The thickness of the metal or metal oxide thin film layer 51 is not particularly limited, but is preferably about 1 nm to 0.5 μm, more preferably 5 nm, from the viewpoint of effectively reducing the moisture permeation amount of the moisture barrier layer 5. About 0.1 μm. The thickness of the resin layer 52 is not particularly limited, but is preferably about 3 to 30 μm, more preferably about 10 to 25 μm.

In the battery packaging material of the present invention, the moisture permeation amount measured according to the JIS K7129B Mocon method of the laminate of the base material layer 1 and the moisture barrier layer 5 is 8 g / m ² · day or less. It is preferably 4.0 g / m ² · day or less. The moisture permeation amount is specifically a value measured by the method described in the examples.

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

  About thickness of the metal layer 3, 10-200 micrometers is preferable, for example, Preferably it is 20-100 micrometers.

  In addition, the metal layer 3 is preferably subjected to chemical conversion treatment on at least one surface, preferably at least the surface on the sealant layer side, and more preferably both surfaces for stabilization of adhesion, prevention of dissolution and corrosion, and the like. Here, the chemical conversion treatment is a treatment for forming an acid-resistant film on the surface of the metal layer 3. Chemical conversion treatment is, for example, chromate chromate treatment using a chromic acid compound such as chromium nitrate, chromium fluoride, chromium sulfate, chromium acetate, chromium oxalate, chromium biphosphate, chromic acetyl acetate, chromium chloride, potassium sulfate chromium, etc. ; Phosphoric acid chromate treatment using phosphoric acid compounds such as sodium phosphate, potassium phosphate, ammonium phosphate, polyphosphoric acid; aminated phenol heavy consisting of repeating units represented by the following general formulas (1) to (4) Examples thereof include chromate treatment using a coalescence. In the aminated phenol polymer, the repeating units represented by the following general formulas (1) to (4) may be included singly or in any combination of two or more. Also good.

In general formulas (1) to (4), X represents a hydrogen atom, a hydroxyl group, an alkyl group, a hydroxyalkyl group, an allyl group or a benzyl group. R ¹ and R ² are the same or different and represent a hydroxyl group, an alkyl group, or a hydroxyalkyl group. In the general formulas (1) to (4), examples of the alkyl group represented by X, R ¹ and R ² include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, C1-C4 linear or branched alkyl groups, such as a tert- butyl group, are mentioned. Examples of the hydroxyalkyl group represented by X, R ¹ and R ² include a hydroxymethyl group, a 1-hydroxyethyl group, a 2-hydroxyethyl group, a 1-hydroxypropyl group, a 2-hydroxypropyl group, 3- A linear or branched chain having 1 to 4 carbon atoms substituted with one hydroxy group such as hydroxypropyl group, 1-hydroxybutyl group, 2-hydroxybutyl group, 3-hydroxybutyl group, 4-hydroxybutyl group An alkyl group is mentioned. In the general formulas (1) to (4), X is preferably any one of a hydrogen atom, a hydroxyl group, and a droxyalkyl group. The number average molecular weight of the aminated phenol polymer composed of the repeating units represented by the general formulas (1) to (4) is, for example, about 500 to about 1,000,000, preferably about 1000 to about 20,000.

  In addition, as a chemical conversion treatment method for imparting corrosion resistance to the metal layer 3, a metal oxide such as aluminum oxide, titanium oxide, cerium oxide, tin oxide, or barium sulfate fine particles dispersed in phosphoric acid is coated. A method of forming a corrosion-resistant layer on the surface of the metal layer by performing a baking treatment at 150 ° C. or higher can be mentioned. A resin layer obtained by crosslinking a cationic polymer with a crosslinking agent may be formed on the corrosion-resistant treatment layer. Here, as the cationic polymer, for example, polyethyleneimine, an ionic polymer complex composed of a polymer having polyethyleneimine and a carboxylic acid, a primary amine-grafted acrylic resin in which a primary amine is grafted on an acrylic main skeleton, polyallylamine, or Examples thereof include aminophenols and derivatives thereof. These cationic polymers may be used individually by 1 type, and may be used in combination of 2 or more type. Examples of the crosslinking agent include compounds having at least one functional group selected from the group consisting of isocyanate groups, glycidyl groups, carboxyl groups, and oxazoline groups, silane coupling agents, and the like. These crosslinking agents may be used alone or in combination of two or more.

  These chemical conversion treatments may be performed alone or in combination of two or more chemical conversion treatments. Furthermore, these chemical conversion treatments may be carried out using one kind of compound alone, or may be carried out using a combination of two or more kinds of compounds. Among these, chromic acid chromate treatment is preferable, and chromate treatment in which a chromic acid compound, a phosphoric acid compound, and the aminated phenol polymer are combined is more preferable.

The amount of the acid-resistant film to be formed on the surface of the metal layer 3 in the chemical conversion treatment is not particularly limited. For example, the chromate treatment may be performed by combining a chromic acid compound, a phosphoric acid compound, and the aminated phenol polymer. For example, the chromic acid compound is about 0.5 to about 50 mg, preferably about 1.0 to about 40 mg in terms of chromium, and the phosphorus compound is about 0.5 to about 50 mg in terms of phosphorus per 1 m ² of the surface of the metal layer. Is about 1.0 to about 40 mg, and the aminated phenol polymer is contained in an amount of about 1 to about 200 mg, preferably about 5.0 to 150 mg.

  In the chemical conversion treatment, a solution containing a compound used for forming an acid-resistant film is applied to the surface of the metal layer by a bar coating method, a roll coating method, a gravure coating method, an immersion method or the like, and then the temperature of the metal layer is 70. It is carried out by heating to about 200 ° C. In addition, before the chemical conversion treatment is performed on the metal layer 3, the metal layer 3 may be subjected to a degreasing treatment by an alkali dipping method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method, or the like in advance. By performing the degreasing treatment in this way, it becomes possible to more efficiently perform the chemical conversion treatment on the surface of the metal layer 3.

[Sealant layer 4]
In the battery packaging material of the present invention, the sealant layer 4 corresponds to the innermost layer, and is a layer that seals the battery element by heat-sealing the sealant layers when the battery is assembled.

  The resin component used for the sealant layer 4 is not particularly limited as long as it can be thermally welded, and examples thereof include polyolefin, cyclic polyolefin, carboxylic acid-modified polyolefin, and carboxylic acid-modified cyclic polyolefin.

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

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

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

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

  Among these resin components, carboxylic acid-modified polyolefin is preferable; carboxylic acid-modified polypropylene is more preferable.

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

  The sealant layer 4 preferably contains a compatible elastomer that is dispersed with a dispersed phase size of 1 nm or more and less than 1 μm. More specifically, in the sealant layer 4, in the resin composition forming the sealant layer 4, it is preferable that the compatible elastomer is dispersed with a dispersed phase size of 1 nm or more and less than 1 μm. In the sealant layer 4, the compatible elastomer is preferably dispersed with a dispersed phase size of 1 nm or more and less than 1 μm in at least one of the acid-modified polyolefin and the acid-modified cyclic polyolefin.

  Such a compatible elastomer has a so-called micro phase separation structure as disclosed in JP2013-258162A. Specifically, the microphase-separated structure is (1) a maximum diameter (d1) of 1 to 200 nm when a dispersed phase (either a flexible component or a constrained component) in a compatible elastomer is approximated as an ellipse. (2) The ratio (d1 / d2) between the maximum diameter (d1) of the dispersed phase (either the flexible component or the constrained component) domain and the maximum value (d2) of the diameter orthogonal to the maximum diameter is 20 It has the above rod shape, and the maximum value (d2) is 1 to 200 nm, or (3) a layered lamellar structure in which it is not possible to determine which of the flexible component and the constraining component is the dispersed phase. And at least one of the layers has a thickness of 1 to 200 nm.

Confirmation of the microphase separation structure in the compatible elastomer can be performed by a known method as disclosed in JP 2013-258162 A, and specifically, as follows. A press sheet of a resin composition containing a compatible elastomer is molded, made into 0.5 mm square pieces, and dyed with ruthenium acid (RuO ₄ ). Using an ultramicrotome (REICHERT S, REICHERT TCS, etc.) equipped with a diamond knife, an ultrathin section having a thickness of about 100 nm is prepared. Next, carbon is vapor-deposited on the ultrathin slice and observed with a transmission electron microscope. At least five observation spots are selected at random, and observed at magnifications of 10,000, 50,000, and 150,000 times. At that time, when the approximation as the ellipse of (1) is performed, using the software of Image-Pro Plus in the field of view observed at 10,000 to 150,000 times with a transmission electron microscope, Axis- By selecting “major”, the dispersed phase (either the flexible component or the constrained component) is approximated to an ellipse having the same area and the same first and second moments, and the major axis is set as the maximum diameter (d1).

  When the compatible elastomer is present in the acid-modified polyolefin resin or the acid-modified cyclic polyolefin, it is preferably dispersed with a dispersed phase size of 1 nm or more and less than 1 μm. The dispersed phase size of the compatible elastomer is preferably 1 nm or more and 200 nm or less from the viewpoint of further improving the insulation. In the present invention, the dispersed phase size of the elastomer in the sealant layer 4 is the diameter when the dispersed phase can be regarded as a circle, the maximum diameter when it can be approximated as an ellipse, and the maximum diameter of the major axis of the aspect ratio in the case of a rod. In the case of a layered lamellar structure, it is the thickness of the layer.

  The compatible elastomer is not particularly limited as long as it is dispersed in the sealant layer 4 with a dispersed phase size of 1 nm or more and less than 1 μm, and a propylene-α-olefin copolymer elastomer is preferably used. One type of compatible elastomer may be used alone, or two or more types may be used in combination. The propylene-α olefin copolymer elastomer has a structural unit derived from propylene and a structural unit derived from one or more kinds selected from α-olefins (excluding propylene) having 2 to 20 carbon atoms, and the propylene A copolymer elastomer having a proportion of structural units derived from is preferably 51 mol% or more. Examples of commercially available propylene-α-olefin copolymer elastomers include Mitsui Chemicals Notio (trade name), Sumitomo Chemical Tough Selenium (trade name), JSR Dynalon (trade name), and the like. Further, for example, an elastomer other than the propylene-α olefin copolymer elastomer disclosed in JP-A-2003-321582 may be used.

  When the sealant layer 4 contains a compatible elastomer, the content of the compatible elastomer in the sealant layer 4 is preferably about 1 to 60% by mass, more preferably about 10 to 50% by mass, and still more preferably 15 to 45% by mass. %.

  The thickness of the sealant layer 4 can be selected as appropriate, and is about 10 to 100 μm, preferably about 15 to 50 μm.

  Further, the sealant layer 4 may contain a slip agent or the like as necessary. When the sealant layer 4 contains a slip agent, the moldability of the battery packaging material can be improved. The slip agent is not particularly limited, and a known slip agent can be used, and examples thereof include those exemplified for the base material layer 1 described above. A slip agent may be used individually by 1 type, and may be used in combination of 2 or more type. The content of the slip agent in the sealant layer 4 is not particularly limited, and is preferably about 0.01 to 0.2% by mass, more preferably 0 from the viewpoint of improving the moldability and insulation of the electronic packaging material. About 0.05 to 0.15 mass%.

[Adhesive layer 6]
In the battery packaging material of the present invention, the adhesive layer 6 is a layer provided between the metal layer 3 and the sealant layer 4 as necessary in order to firmly bond the metal layer 3 and the sealant layer 4.

  The adhesive layer 6 is formed of an adhesive capable of bonding the metal layer 3 and the sealant layer 4. Regarding the adhesive used for forming the adhesive layer 6, the adhesive mechanism, the types of adhesive components, and the like are the same as those of the adhesive layer 2. The adhesive component used for the adhesive layer 6 is preferably a polyolefin-based resin, more preferably a carboxylic acid-modified polyolefin, and particularly preferably a carboxylic acid-modified polypropylene.

  About the thickness of the contact bonding layer 6, 2-50 micrometers, for example, Preferably 20-30 micrometers is mentioned.

2. 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 in which layers having a predetermined composition are laminated is obtained. For example, the following method is exemplified. .

  First, the base material layer 1, the adhesive layer 2, and the metal layer 3 are sequentially laminated, and further, the laminated body in which the moisture barrier layer 5 is laminated on the base material layer 1 side from the adhesive layer 2 (hereinafter referred to as “laminated body A”). May be written). Specifically, the laminate A is formed on the substrate layer 1 (on the moisture barrier layer 5 when the moisture barrier layer 5 is laminated between the substrate layer 1 and the metal layer 3), or After applying and drying the adhesive used for forming the adhesive layer 2 on the metal layer 3 whose surface is subjected to chemical conversion treatment as necessary by a coating method such as a gravure coating method or a roll coating method, the metal layer 3 or the substrate layer 1 (or the moisture barrier layer 5) can be laminated by a dry lamination method in which the adhesive layer 2 is cured.

  At this time, for example, when the thin film layer 51 is laminated as the moisture barrier layer 5 between the base material layer 1 and the metal layer 3, the base material layer 1 provided with the thin film layer 51 and the metal layer 3 are combined. By laminating by the dry lamination method, a laminate A in which the base material layer 1 / thin film layer 51 / adhesive layer 2 / metal layer 3 are laminated in order is obtained.

  Further, when a laminate of the thin film layer 51 and the resin layer 52 (hereinafter also referred to as “laminate B”) is laminated between the base material layer 1 and the metal layer 3, the laminate After laminating B and the metal layer 3 by the dry lamination method, the base material layer 1 may be laminated on the outside of the laminate B. Moreover, after laminating | stacking the base material layer 1 and the laminated body B, you may laminate | stack the obtained laminated body and the metal layer 3 by the dry lamination method. In any method, the laminate A in which the base layer 1 / thin film layer 51 / resin layer 52 / adhesion layer 2 / metal layer 3 are laminated in order, or the base material layer 1 / resin layer 52 / thin film layer 51 / adhesion. A layered product A in which layer 2 / metal layer 3 are sequentially laminated is obtained.

  When the moisture barrier layer 5 is laminated on the outside of the base material layer 1, the moisture barrier layer 5 may be laminated in any state before and after the base material layer 1 and the metal layer 3 are laminated.

  Next, the sealant layer 4 is laminated on the metal layer 3 of the laminate A. When the sealant layer 4 is directly laminated on the metal layer 3, the resin component constituting the sealant layer 4 may be applied on the metal layer 3 of the laminate A by a method such as a gravure coating method or a roll coating method. . When the adhesive layer 6 is provided between the metal layer 3 and the sealant layer 4, for example, (1) Lamination is performed by coextruding the adhesive layer 6 and the sealant layer 4 on the metal layer 3 of the laminate A. (2) A method of separately forming a laminate in which the adhesive layer 6 and the sealant layer 4 are laminated, and laminating the laminate on the metal layer 3 of the laminate A by a thermal lamination method, 3) An adhesive for forming the adhesive layer 6 is laminated on the metal layer 3 of the laminate A by an extrusion method, a solution-coated high temperature drying or baking method, and the like in a sheet form in advance. (4) A melted adhesive layer 6 is placed between the metal layer 3 of the laminate A and the sealant layer 4 previously formed into a sheet shape. Adhesive layer 6 while pouring Method (sand lamination method) and the like to bond the laminate A and the sealant layer 4.

  As described above, the base layer 1 / moisture barrier layer 5 / adhesive layer 2 / metal layer 3 whose surface is subjected to chemical conversion treatment as necessary / adhesive layer 6 / sealant layer 4 provided as necessary Body or moisture barrier layer 5 / base material layer 1 / adhesive layer 2 / metal layer 3 whose surface is subjected to chemical conversion treatment as needed / adhesive layer 6 / sealant layer 4 provided as needed However, in order to strengthen the adhesiveness of the adhesive layer 2 and the adhesive layer 6 provided as necessary, it may be further subjected to a heat treatment such as a hot roll contact type, a hot air type, a near or far infrared type. Good. Examples of such heat treatment conditions include 150 to 250 ° C. for 1 to 5 minutes.

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

3. Characteristics and Applications of Battery Packaging Material The battery packaging material of the present invention is used as a packaging material for sealing and housing battery elements such as a positive electrode, a negative electrode, and an electrolyte.

  Specifically, a battery element including at least a positive electrode, a negative electrode, and an electrolyte is formed using the battery packaging material of the present invention, with the metal terminals connected to each of the positive electrode and the negative electrode protruding outward. A battery using a battery packaging material is formed by covering the periphery of the element so that a flange portion (a region where the sealant layers are in contact with each other) can be formed, and heat-sealing and sealing the sealant layers of the flange portion. Provided. In addition, when accommodating a battery element using the battery packaging material of the present invention, the battery packaging material of the present invention is used such that the sealant portion is on the inner side (surface in contact with the battery element).

  The battery packaging material of the present invention may be used for either a primary battery or a secondary battery, but 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. For example, a lithium ion battery, a lithium ion polymer battery, a lead battery, a nickel / hydrogen battery, a nickel / cadmium battery , Nickel / iron livestock batteries, nickel / zinc livestock batteries, silver oxide / zinc livestock batteries, metal-air batteries, polyvalent cation batteries, capacitors, capacitors and the like. Among these secondary batteries, lithium ion batteries and lithium ion polymer batteries can be cited as suitable applications of the battery packaging material of the present invention.

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

<Manufacture of battery packaging materials>
Example 1
Chemical conversion treatment is performed on both surfaces of an aluminum foil (thickness 40 μm) as the metal layer 3, and a base material layer 1 (PET (polyethylene terephthalate), thickness 12 μm) and a thin film layer 51 as a moisture barrier layer are formed on one chemical conversion treatment surface. (Aluminum vapor deposition layer, thickness 0.01 μm) Laminate with a polyurethane adhesive (polyester-based main agent and isocyanate-based curing agent two-component urethane two-liquid so that the thickness of the adhesive layer 2 is about 3 μm Bonding was performed by a dry laminating method via a curable adhesive. At this time, the thin film layer 51 was on the metal layer 3 side. Next, the resin component forming the sealant layer 4 is co-extruded in a molten state so that acid-modified polypropylene (maleic anhydride-modified polypropylene, PPa) and polypropylene (PP) are in this order from the metal layer 3 side. Thus, a sealant layer 4 composed of two layers of an acid-modified polypropylene layer (PPa layer, thickness 23 μm) and a polypropylene layer (PP layer, thickness 23 μm) was laminated on the metal layer 3. The total thickness of the sealant layer 4 is as shown in Table 1, and the thicknesses of the PPa layer and the PP layer were 1: 1.

Example 2
In Example 2, a battery packaging material was produced in the same manner as in Example 1 except that biaxially stretched nylon was used for the base material layer 1.

Example 3
In Example 3, a battery packaging material was produced in the same manner as in Example 1 except that an alumina vapor deposition layer (thickness 11 nm) was used for the thin film layer 51.

Comparative Example 1
In Comparative Example 1, a battery packaging material was produced in the same manner as in Example 1 except that the thin film layer 51 was not provided.

Comparative Example 2
In Comparative Example 2, a battery packaging material was produced in the same manner as in Example 2 except that the thin film layer 51 was not provided.

[Measurement method of moisture permeation rate of laminate of substrate layer and moisture barrier layer]
Measurement was performed according to JIS K7129B using “PERMATRAN-W 3/61” manufactured by MOCON. The measurement environment was 40 ° C. and a humidity of 90% RH. The measured value after 4 hours was taken as the water vapor transmission rate of the laminate of the base material layer and the thin film layer.

[Measurement of laminate strength]
The battery packaging material obtained in each example and comparative example was cut into a width of 15 mm in the TD direction to prepare a test piece. Using the tensile tester (manufactured by Shimadzu Corp., AGS-50D (trade name)), the obtained test piece was subjected to a condition of a temperature of 23 ° C., a humidity of 50% RH, a speed of 50 mm / min, and a chuck distance of 30 mm Then, the base material layer and the metal layer were peeled, and the maximum strength at the time of peeling was defined as the laminate strength (strength A).
Next, the test piece after measurement was stored for 1900 hours in an environment of a temperature of 80 ° C. and a humidity of 95% RH. For each specimen after storage, using a tensile tester in the same way as before storage, under conditions of a temperature of 23 ° C., humidity of 50% RH, a speed of 50 mm / min, and a distance between chucks of 30 mm, the base material layer and the metal The layer was peeled off, and the maximum strength at the time of peeling was defined as the laminate strength (strength B). The results are shown in Table 1.

[Measurement of Δb ^* ]
About each test piece before and after the storage, the color difference meter (CM-2500d manufactured by Konica Minolta Co., Ltd.) was used to measure the b ^* value of the L ^* a ^* b ^* color system from the base material layer side. The difference (Δb ^* ) was calculated. The results are shown in Table 1.

From the results shown in Table 1, in the battery packaging materials of Examples 1 to 3 in which the moisture barrier layer was provided on the substrate layer side relative to the adhesive layer disposed between the substrate layer and the metal layer, Deterioration of the adhesive layer due to moisture was effectively suppressed, and the laminate strength B after storage in a humid heat environment showed a high value. Moreover, in the battery packaging materials of Examples 1 to 3, the value of Δb ^* was small, and yellowing was effectively suppressed. On the other hand, in the battery packaging materials of Comparative Examples 1 and 2 in which the moisture barrier layer was not provided, the adhesive layer was deteriorated by moisture, and the laminate strength B after being stored in a humid heat environment was low. Moreover, in the battery packaging materials of Comparative Examples 1 and 2, the value of Δb ^* was very large and yellowed.

DESCRIPTION OF SYMBOLS 1 Base material layer 2 Adhesive layer 3 Metal layer 4 Sealant layer 5 Moisture barrier layer 6 Adhesive layer

Claims (8)

At least, the base layer, the adhesive layer, a metal layer, and a sealant layer comprising a packaging material for a battery ing a laminate having, in this order,
A moisture barrier layer having a thin film layer is laminated between the base material layer and the adhesive layer,
The thin film layer is made of metal or metal oxide,
The thickness of the thin film layer is 5 nm or more and 0.5 μm or less,
After the battery packaging material is stored for 1900 hours in an environment of a temperature of 80 ° C. and a humidity of 95% RH, the laminate strength between the base material layer and the metal layer is 2.0 N / 15 mm or more, and
A battery packaging material in which the difference (Δb ^* ) in the b ^* value of the L ^* a ^* b ^* color system measured from the substrate layer side before and after the storage is 1.0 or less . A battery packaging material comprising a laminate having at least a base material layer, an adhesive layer, a metal layer, and a sealant layer in this order,
  A moisture barrier layer having a thin film layer is laminated between the base material layer and the adhesive layer,
  The thin film layer is made of metal or metal oxide,
  The thickness of the thin film layer is 5 nm or more and 0.5 μm or less,
  The amount of moisture permeation measured according to the JIS K7129B Mocon method of the laminate of the base material layer and the moisture barrier layer is 8 g / m. ² Battery packaging material that is not more than day. A battery packaging material comprising a laminate having at least a base material layer, an adhesive layer, a metal layer, and a sealant layer in this order,
A moisture barrier layer is laminated outside the substrate layer;
The moisture barrier layer is a laminate of a thin film layer and a resin layer,
The thin film layer is not located on the outermost surface of the battery packaging material,
The thin film layer is made of metal or metal oxide,
The thickness of the thin film layer is 5 nm or more and 0.5 μm or less,
After the battery packaging material is stored for 1900 hours in an environment of a temperature of 80 ° C. and a humidity of 95% RH, the laminate strength between the base material layer and the metal layer is 2.0 N / 15 mm or more, and
A battery packaging material in which the difference (Δb ^* ) in the b ^* value of the L ^* a ^* b ^* color system measured from the substrate layer side before and after the storage is 1.0 or less .   A battery packaging material comprising a laminate having at least a base material layer, an adhesive layer, a metal layer, and a sealant layer in this order,
  A moisture barrier layer is laminated outside the substrate layer;
  The moisture barrier layer is a laminate of a thin film layer and a resin layer,
  The thin film layer is not located on the outermost surface of the battery packaging material,
  The thin film layer is made of metal or metal oxide,
  The thickness of the thin film layer is 5 nm or more and 0.5 μm or less,
  The amount of moisture permeation measured according to the JIS K7129B Mocon method of the laminate of the base material layer and the moisture barrier layer is 8 g / m. ² Battery packaging material that is not more than day.   The amount of moisture permeation measured according to the JIS K7129B Mocon method of the laminate of the base material layer and the moisture barrier layer is 8 g / m. ² -The packaging material for batteries of Claim 1 or 3 which is below day.   After the battery packaging material is stored for 1900 hours in an environment of a temperature of 80 ° C. and a humidity of 95% RH, the laminate strength between the base material layer and the metal layer is 2.0 N / 15 mm or more, and
  L measured from the base material layer side before and after the storage ^* a ^* b ^* Color system b ^* Value difference (Δb ^* ) Is 1.0 or less, the battery packaging material according to claim 2 or 4. The battery packaging material according to any one of claims 1 to 6 , wherein the adhesive layer is formed of a polyurethane-based adhesive. At least a positive electrode, a negative electrode, and a battery device having an electrolyte is housed in the battery packaging the material according to any one of claims 1 to 7 batteries.