JP6496979B2 - Battery packaging materials - Google Patents

Description

  The present invention relates to a battery packaging material having designability or distinguishability, which is excellent in concealability and adhesion after molding, and excellent in electrolytic solution resistance and surface insulation.

  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.

In recent years, from the standpoint of preventing counterfeiting, the appearance of the battery may be required to be provided with designability, identification, etc., and pigments are incorporated into the outermost layer of the battery packaging material. To give decorativeness. For example, in Patent Document 2, at least a first adhesive layer, a metal foil layer, a second adhesive layer, and a sealant layer are sequentially laminated on one surface side of the base material layer, and on the other surface side of the base material layer, An identification layer which is a resin layer having a glossiness of 3.0 or less for identification, the identification layer contains a pigment for identification, and particles of the pigment are coated with a resin; An outer packaging material for a lithium ion secondary battery characterized by a specific resistance of 5 × 10 ⁻² Ω · m or more is disclosed.

JP 2008-287971 A JP 2013-235719 A

The layer located at the outermost layer of the battery packaging material is not only a pigment for imparting decorative properties such as the above-mentioned designability and distinguishability, but also from the viewpoint of the electrolytic solution resistance of the battery surface, etc. In some cases, a liquid-resistant resin to which a matting agent such as a filler is added is used. However, as a result of studies by the present inventor, when a matting agent such as a filler is added to the identification layer as disclosed in Patent Document 2 in addition to a colorant such as a pigment that is a solid particle, the electrolyte solution resistance Further, it has been revealed that there is a problem that the adhesion of the identification layer after molding is lowered. On the other hand, if the blending ratio of a colorant such as a pigment or a matting agent is reduced in order to suppress a decrease in resistance to electrolytic solution, there is a problem that the concealability after molding a battery packaging material is likely to be lowered. .
Under such circumstances, the present invention is a battery packaging material having designability or distinctiveness, excellent in concealability and adhesion after molding, and excellent in electrolyte solution resistance and surface insulation. The main purpose is to provide battery packaging materials.

  The present inventor has intensively studied to solve the above problems. As a result, at least a decorative layer, a base material layer, a metal layer, and a sealant layer are sequentially laminated, and the decorative layer has at least the first decorative layer and the second decorative layer in order from the base material layer side. The battery packaging material having a decorative layer containing a pigment and a matting agent and having a resin ratio of 60% by mass or more in each of the first decorative layer and the second decorative layer has designability or distinguishability. It has been found that it has excellent concealability and adhesion after molding, and is also excellent in electrolytic solution resistance and surface insulation. The present invention has been completed by further studies based on these findings.

That is, this invention provides the battery packaging material and battery of the aspect hung up below.
Item 1. At least a decorative layer, a base material layer, a metal layer, and a laminate in which a sealant layer is sequentially laminated,
The decorative layer, in order from the base material layer side, has at least a first decorative layer and a second decorative layer,
The decorative layer includes a colorant and a matting agent;
Each of the first decorative layer and the second decorative layer is a battery packaging material having a resin ratio of 60% by mass or more.
Item 2. Item 2. The battery packaging material according to Item 1, wherein the ratio of the matting agent in the first decorative layer is 1 to 30% by mass.
Item 3. Item 3. The battery packaging material according to Item 1 or 2, wherein the first decorative layer contains 1 to 30% by mass of a pigment as a colorant.
Item 4. Item 4. The battery packaging material according to any one of Items 1 to 3, wherein the proportion of the resin in the first decorative layer is 65% by mass or more.
Item 5. Item 5. The battery packaging material according to any one of Items 1 to 4, wherein a ratio of the matting agent in the second decorative layer is 1 to 30% by mass.
Item 6. Item 6. The battery packaging material according to any one of Items 1 to 5, wherein the second decorative layer contains 1 to 30% by mass of a pigment as a colorant.
Item 7. Item 7. The battery packaging material according to any one of Items 1 to 6, wherein a ratio of the resin in the second decorative layer is 65% by mass or more.
Item 8. Item 8. The battery packaging material according to any one of Items 1 to 7, wherein the resin forming the decoration layer is a two-component curable resin.
Item 9. Item 10. The battery packaging material according to any one of Items 1 to 8, wherein the colorant is a black pigment.
Item 10. Item 10. The battery packaging material according to any one of Items 1 to 9, wherein the metal layer is formed of an aluminum foil.
Item 11. Item 11. A battery in which a battery element including at least a positive electrode, a negative electrode, and an electrolyte is contained in the battery packaging material according to any one of Items 1 to 10.

  According to the battery packaging material of the present invention, it is a battery packaging material having designability or distinctiveness, excellent in concealability and adhesion after molding, and excellent in electrolytic solution resistance and surface insulation. A battery packaging material can be provided. Furthermore, according to this invention, the battery using the said packaging material for batteries can be provided.

It is a figure which shows an example of the cross-section of the packaging material for batteries of this invention. It is a figure which shows an example of the cross-section of the packaging material for batteries of this invention.

  The battery packaging material of the present invention comprises a laminate in which at least a decorative layer, a base material layer, a metal layer, and a sealant layer are sequentially laminated, and the decorative layer is at least a first decorative layer in order from the base material layer side. And the second decorative layer, the decorative layer includes a colorant and a matting agent, and the first decorative layer and the second decorative layer each have a resin ratio of 60% by mass or more. To do. Hereinafter, the battery packaging material of the present invention will be described in detail.

1. As shown in FIG. 1, the battery packaging material is composed of a laminate in which at least a decorative layer 5, a base material layer 1, a metal layer 3, and a sealant layer 4 are sequentially laminated. The decoration layer 5 includes at least a first decoration layer 5a and a second decoration layer 5b in order from the base material layer 1 side. In the battery packaging material of the present invention, the decorative layer 5 is the outermost layer, and the sealant layer 4 is the innermost layer. That is, when the battery is assembled, the sealant layers 4 positioned at the periphery of the battery element are thermally welded to seal the battery element, thereby sealing the battery element.

  As shown in FIG. 1, the battery packaging material of the present invention is provided with an adhesive layer 2 between the base material layer 1 and the metal layer 3 as necessary for the purpose of enhancing the adhesion. Also good. In addition, as shown in FIG. 2, an adhesive layer 6 may be provided between the metal layer 3 and the sealant layer 4 as necessary for the purpose of improving the adhesion.

2. 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 serving as a base material located inside the decorative layer 5 located in the outermost layer. 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 resin, acrylic resin, fluorine resin, polyurethane, silicon resin, phenol resin, polyetherimide, polyimide, and a mixture or copolymer thereof. Can be mentioned.

  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 include a structural unit derived from isophthalic acid, Aromatic polyamides 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.

  As thickness of the base material layer 1, 10-50 micrometers, 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 as necessary in order to adhere the base material layer 1 and the metal layer 3.

  The adhesive layer 2 is formed of an adhesive capable of adhering the base material layer 1 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 lamination strength between the base material layer 1 and the metal layer 3 is suppressed. From the viewpoint of effectively suppressing the occurrence of delamination, a polyurethane two-component curable adhesive; polyamide, polyester, or a blended resin of these with a modified polyolefin is preferable.

  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 lamination 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. It is preferable to select a resin having excellent adhesion to the metal layer 3 and to select an adhesive component having excellent adhesion to the metal layer 3 as the 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.

[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 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 such as 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.

  Further, 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 4 side, and more preferably both surfaces, for the purpose of stabilizing adhesion, preventing 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 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 treatment layer on the surface of the metal layer 3 by performing a baking treatment at 150 ° C. or higher can be mentioned. Moreover, you may form the resin layer which crosslinked the cationic polymer with the crosslinking agent on the corrosion-resistant process 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 an aminated phenol polymer are combined is more preferable.

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

  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 3 by a bar coating method, a roll coating method, a gravure coating method, a dipping method or the like, and then the temperature of the metal layer 3 is reached. Is performed by heating so as to be about 70 to 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 thickness of the sealant layer 4 can be selected as appropriate, and is about 10 to 100 μm, preferably about 15 to 50 μm.

[Decoration layer 5]
In the battery packaging material of the present invention, the decorative layer 5 is a layer provided for the purpose of imparting decorative properties such as designability and distinguishability to the battery packaging material, and for imparting electrolytic solution resistance. Yes, it is a layer located on the outer side (outermost layer) of the base material layer 1 when the battery is assembled.

  The decoration layer 5 has at least a first decoration layer 5a and a second decoration layer 5b in order from the base material layer 1 side. The decoration layer 5 is one or more than the second decoration layer 5b, or between the first decoration layer 5a and the second decoration layer 5b, such as the third decoration layer 5c and the fourth decoration layer 5d. You may have a decoration layer. That is, in the case where the decoration layer 5 includes another decoration layer in addition to the first decoration layer 5a and the second decoration layer 5b, the other decoration layer is an arbitrary one outside the first decoration layer 5a. It may be provided at a position.

  In the battery packaging material of the present invention, the decorative layer 5 includes a colorant and a matting agent, and the decorative layer 5 includes a first decorative layer 5 a and a second decorative layer 5. In the present invention, the decorative layer 5 having such a configuration makes it possible to provide a battery packaging material that is excellent in concealability and adhesion after molding, and also excellent in electrolytic solution resistance and surface insulation. Can do. In other words, the decorative layer 5 is provided with high concealability after molding based on containing a colorant and high electrolytic solution resistance by containing a matting agent. Furthermore, by setting the ratio of the resin in the first decorative layer 5a and the second decorative layer 5b to 60% by mass or more, the adhesion after molding and the resistance to electrolytic solution are effectively enhanced. . From the viewpoint of further improving concealability, adhesion, electrolytic solution resistance, and surface insulation, the first decorative layer 5a is positioned on the base material layer 1, and the second decorative layer 5b is a battery packaging. It is preferably located in the outermost layer of the material.

  The colorant contained in the decorative layer 5 is not particularly limited as long as it can color the decorative layer 5, but preferably includes pigments and dyes, and more preferably pigments. A colorant may be used individually by 1 type and may be used in combination of 2 or more types.

  The pigment is not particularly limited as long as it can impart decorative properties such as designability and distinguishability to the battery packaging material, and examples thereof include black pigments. Although it does not restrict | limit especially as a black pigment, Preferably carbon black etc. are mentioned. A pigment may be used individually by 1 type and may be used in combination of 2 or more types.

  The particle diameter of the pigment is not particularly limited, but is preferably about 1 nm to 20 μm. The pigment particle diameter means a value measured by a laser diffraction scattering method.

  Examples of the dye include nitro dyes, azo dyes, stilbene dyes, carbonium dyes, quinoline dyes, methine dyes, thiazole dyes, quinimine dyes, anthraquinone dyes, indigoid dyes, and phthalocyanine dyes. One type of dye may be used alone, or two or more types may be used in combination.

  The matting agent is not particularly limited as long as it can impart electrolytic solution resistance to the battery packaging material, and examples thereof include fine particles having a particle diameter of about 1 nm to 20 μm. The particle size of the matting agent means a value measured by a laser diffraction scattering method.

  The material of the matting agent (filler) 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, kaolin, montmorilloid, montmorillonite, synthetic mica, hydrotalcite, silica gel, zeolite, aluminum hydroxide, magnesium hydroxide, zinc oxide, magnesium oxide, aluminum oxide, and oxidation. Neodymium, antimony oxide, titanium oxide, cerium oxide, calcium sulfate, barium sulfate, calcium carbonate, calcium silicate, lithium carbonate, calcium benzoate, calcium oxalate, magnesium stearate, alumina, high melting point nylon, crosslinked acrylic, crosslinked styrene , Crosslinked polyethylene, benzoguanamine, gold, aluminum, copper, nickel, resin beads, colored resin beads, 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.

  When a pigment is contained in the first decorative layer 5a, the ratio of the pigment in the first decorative layer 5a is preferably from the viewpoint of further improving the concealability, adhesion, electrolytic solution resistance, and surface insulation. Is about 1 to 30% by mass, more preferably about 5 to 25% by mass. When the pigment is contained in the second decorative layer 5b, the ratio of the pigment in the second decorative layer 5b is preferably about 1 to 30% by mass, more preferably about 5 to 25% by mass from the same viewpoint. Can be mentioned. In the present invention, since the ratio of the resin in the first decorative layer 5a and the second decorative layer 5b is both set to 60% by mass or more, the decorative layer 5 contains pigments and matting agents that are solid particles. Even in this case, the adhesion after molding and the resistance to electrolytic solution are effectively enhanced. For this reason, the present invention is particularly effective for a decorative sheet using a pigment as a colorant.

  Further, when the matting agent is included in the first decorative layer 5a, the ratio of the matting agent in the first decorative layer 5a is the above-mentioned concealing property, adhesion, electrolytic solution resistance, and surface insulation. From a viewpoint of improving, Preferably it is about 1-30 mass%, More preferably, about 5-15 mass% is mentioned. When the matting agent is contained in the second decorative layer 5b, the ratio of the matting agent in the second decorative layer 5b is preferably about 1 to 30% by mass, more preferably 5 to 15% by mass from the same viewpoint. Degree.

  When a pigment is used as the colorant, the ratio of the pigment in the entire decorative layer 5 is preferably about 1 to 30% by mass, more preferably about 5 to 25% by mass. As a ratio of the matting agent in the whole decoration layer 5, Preferably it is about 1-30 mass%, More preferably, about 5-15 mass% is mentioned.

  The ratio of the resin in the first decorative layer 5a and the second decorative layer 5b is not particularly limited as long as it is 60% by mass or more. However, the concealability, adhesion, electrolytic solution resistance, and surface insulation are further improved. From the viewpoint of making it, it is preferably 65% by mass or more, more preferably about 70% by mass to 85% by mass. Furthermore, from the same viewpoint, the proportion of the resin in the entire decorative layer 5 is preferably 60% by mass or more, more preferably 65% by mass or more, and still more preferably about 70% by mass to 85% by mass.

  It does not restrict | limit especially as resin which forms the decoration layer 5, For example, 2 liquid curable resin is mentioned. The two-component curable resin is not particularly limited as long as it has an electrolytic solution resistance. For example, the two-component curable urethane resin, the two-component curable acrylic resin, the two-component curable polyester resin, and the two-component curable resin. Type epoxy resin. The resin forming the decoration layer 5 may be used alone or in combination of two or more.

  Among these two-component curable resins, a two-component curable urethane resin containing a polyol and an isocyanate curing agent is preferable as the resin for forming the decoration layer 5.

  Specific examples of the polyol include polyester polyol, acrylic polyol, polyether polyol, polyurethane polyol and the like. Specific examples of the isocyanate curing agent include methylene diisocyanate, isopropylene diisocyanate, lysine diisocyanate, 2,2,4- or 2,4,4-trimethylhexamethylene diisocyanate, 1,6-hexamethylene diisocyanate, methylcyclohexane. Examples thereof include diisocyanate, isophorone diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, and isopropylidene dicyclohexyl-4,4′-diisocyanate. Further, the isocyanate curing agent may be an adduct body, a burette body or an isocyanurate body of these isocyanate compounds.

  The decorative layer 5 may contain additives such as a slip agent, a flame retardant, an antioxidant, a light stabilizer, a tackifier, a leveling agent, and an antifoaming agent as necessary. 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 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.

  The method for forming the decoration layer 5 is not particularly limited. For example, an ink containing at least one of a resin for forming the decoration layer 5, a colorant and a matting agent, a solvent, and the like is used for one of the base material layers 1. The method of apply | coating and printing on the surface of this is mentioned. When the matting agent is blended, the matting agent may be added to the two-component curable resin, mixed, and then applied.

  The decoration layer 5 is preferably formed to be thin enough to provide decoration and electrolyte resistance. The total thickness of the decoration layer 5 is preferably 10 μm or less, more preferably about 2 to 8 μm. More preferably, about 3-6 micrometers is mentioned. As thickness of the 1st decoration layer 5a, about 1-4 micrometers is preferable, for example, Preferably about 2-3 micrometers is mentioned. Moreover, as thickness of the 2nd decoration layer 5b, about 1-4 micrometers is preferable, for example, Preferably about 2-3 micrometers is mentioned.

  When the decoration layer 5 further includes another decoration layer such as the third decoration layer 5c as described above, the ratio of the colorant, matting agent, resin, etc. in the other decoration layer is the first decoration layer 5a or It can be the same as that of the second decorative layer 5b. The same can be applied to the thickness.

High insulation is required for battery packaging materials. In the battery packaging material of the present invention, the surface resistance value of the decorative layer 5 located in the outermost layer is, for example, 10 ⁴ Ω / sq or more, preferably 10 ⁶ Ω / sq or more. The surface resistance value of the decorative layer 5 of the battery packaging material of the present invention is a value measured using a Hiresta UP “trade name, manufactured by Mitsubishi Chemical Corporation” at 22 ° C. and a relative humidity of 40%. .

[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 15-30 micrometers is mentioned.

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

  First, a laminate in which the base material layer 1, the adhesive layer 2, and the metal layer 3 are laminated in order (hereinafter also referred to as “laminate A”) is formed. Specifically, the laminate A is formed by extruding an adhesive used for forming the adhesive layer 2 on the base layer 1 or the metal layer 3 whose surface is subjected to chemical conversion treatment, if necessary. It can be performed by a dry lamination method in which the metal layer 3 or the base material layer 1 is laminated and the adhesive layer 2 is cured after being applied and dried by a coating method such as a method or a roll coating method.

  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.

  Furthermore, on the base material layer 1, the decorative layer 5 is printed in the order of the first decorative layer 5a and the second decorative layer 5b, so that the second decorative layer 5b / the first decorative layer 5a / the base material layer 1 / required. Thus, a laminate composed of an adhesive layer 2 provided according to the requirement / a metal layer 3 whose surface is subjected to a chemical conversion treatment as necessary / an adhesive layer 6 provided as necessary / a sealant layer 4 is formed. In addition, 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. 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.

4). Application 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 are suitable applications for 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.

Examples 1-4 and Comparative Examples 1-4
<Manufacture of battery packaging materials>
A chemical conversion treatment is applied to both sides of an aluminum foil (thickness 30 μm), and a stretched nylon film (thickness 15 μm) is applied to one chemical conversion treatment surface via a polyester adhesive so that the thickness of the adhesive layer is about 3 μm. And bonded together by a dry laminating method. Next, aluminum / acid-modified polypropylene subjected to melt-extrusion of an acid-modified polypropylene (thickness 15 μm) / polypropylene (thickness 15 μm) on the other chemical conversion treatment surface and subjected to stretched nylon film / polyester adhesive / double-side chemical conversion treatment / A laminate composed of polypropylene was obtained. In each of the chemical conversion treatments, an aqueous solution composed of a phenol resin, a chromium fluoride compound, and phosphoric acid was used as a treatment solution, applied by a roll coating method, and baked under conditions where the film temperature was 180 ° C. or higher. The amount of chromium applied was 10 mg / m ² (dry weight).

  Next, in Examples 1 to 4 and Comparative Examples 1 to 3, inks having the composition shown in Table 1 were printed in order by the gravure coating method on the surface of the stretched nylon film of the obtained laminate, The first decorative layer (thickness 4 μm) and the second decorative layer (4 μm) are formed in this order, and the second decorative layer / first decorative layer / stretched nylon film / polyester adhesive / double-sided conversion aluminum / A laminate in which acid-modified polypropylene / polypropylene was sequentially laminated was formed. The obtained laminate was left to stand at 40 ° C. for 3 days for aging to obtain battery packaging materials of Examples 1 to 4 and Comparative Examples 1 to 3.

  In Comparative Example 4, a laminate (decorative layer) in which an ink having the composition shown in Table 1 was printed on the surface of the stretched nylon film of the obtained laminate by a gravure coating method, and one decorative layer was laminated. / Stretched nylon film / polyester-based adhesive / laminated aluminum / acid-modified polypropylene / polypropylene laminated in order). The obtained laminate was aged at 40 ° C. for 3 days to obtain a battery packaging material of Comparative Example 4.

[Evaluation of concealment]
The battery packaging materials obtained in Examples 1 to 4 and Comparative Examples 1 to 43 were stretched 100% in the uniaxial direction, and then observed from the second decorative layer side, and the presence or absence of the foundation was visually confirmed. The case where the base was exposed was evaluated as low concealment (x), and the case where the base was not exposed was evaluated as high (o). The results are shown in Table 1.

[Evaluation of adhesion]
After the battery packaging materials obtained in Examples 1 to 4 and Comparative Examples 1 to 4 were stretched 100% in the uniaxial direction, the presence or absence of peeling, floating, cracks, etc. in the second decorative layer and the first decorative layer was visually observed. confirmed. The case where peeling, floating, cracking, or the like occurred was evaluated as low adhesion (x), and the case where it did not occur was evaluated as high adhesion (◯). The results are shown in Table 1.

[Evaluation of surface insulation]
The surface resistance value of the second decorative layer located in the outermost layer of the battery packaging material obtained in Examples 1 to 4 and Comparative Examples 1 to 4 was measured using Hiresta UP “trade name, manufactured by Mitsubishi Chemical Corporation”. The measurement was performed at 22 ° C. and a relative humidity of 40%. The evaluation criteria are as follows.
○: The surface resistance value is 10 ⁶ Ω / sq or more, and the surface insulation is high.
Δ: The surface resistance value is 10 ⁴ Ω / sq or more and less than 10 ⁶ Ω / sq, and the surface insulation is slightly low.
X: The surface resistance value is less than 10 ⁴ Ω / sq, and the surface insulation is low.

[Evaluation of electrolyte resistance]
On the surface of the second decorative layer of the battery packaging material obtained in Examples 1 to 4 and Comparative Examples 1 to 4, an electrolytic solution (composition of electrolytic solution: ethylene carbonate, diethyl carbonate, dimethyl carbonate containing 1M LiPF ₆ ( (1: 1: 1) in a volume ratio was dropped and left for 1 hour in an environment of 25 ° C. and 50% humidity, and then the surface condition after wiping the electrolyte with a waste cloth containing ethanol was measured. Observed. When the surface was changed, the electrolytic solution resistance was low (x), and when the surface was not changed, the electrolytic solution resistance was high (◯). The results are shown in Table 1.

The annotations in Table 1 are shown below.
Black pigment: Carbon black (particle size: about 0.3 to 0.4 μm)
Matting agent: silica particles (particle size: about 0.1 to 3.0 μm)
Resin: Polyester polyol (80% by mass), isocyanate curing agent (20% by mass)

  As is apparent from the results shown in Table 1, Example 1 in which the decorative layer contains a predetermined amount of pigment and a matting agent, and the ratios of the resins in the first decorative layer and the second decorative layer are both 70% by mass or more. The battery packaging materials (4) to (4) were excellent in concealability and adhesion after molding, and were also excellent in surface insulation and electrolyte resistance. On the other hand, in the battery packaging material of Comparative Example 1 in which the ratio of the resin in the first decorative layer was 50% by mass, the adhesion was low. In addition, in the battery packaging material of Comparative Example 2 in which the ratio of the resin in the second decorative layer located in the outermost layer is 50% by mass, the second decorative layer includes a matting agent, but is resistant to resistance. Electrolyte property became low. Moreover, in the battery packaging material of Comparative Example 3 in which the ratio of the resin in the second decorative layer located in the outermost layer is 40% by mass or less, the ratio of the black pigment in the second decorative layer in order to improve the concealability This is because not only the electrolytic solution resistance but also the surface insulation was lowered. Moreover, in the battery packaging material of Comparative Example 4 in which one decorative layer corresponding to the composition obtained by mixing the first decorative layer and the second decorative layer formed in Example 1 was provided, the concealability after molding was insufficient. Met. Further, when one layer was formed as in Comparative Example 4, the matting effect by the matting agent was also low.

DESCRIPTION OF SYMBOLS 1 Base material layer 2 Adhesion layer 3 Metal layer 4 Sealant layer 5 Decoration layer 5a First decoration layer 5b Second decoration layer 6 Adhesion layer

Claims (10)

At least a decorative layer, a base material layer, a metal layer, and a laminate in which a sealant layer is sequentially laminated,
The decorative layer, in order from the base material layer side, has at least a first decorative layer and a second decorative layer,
The decorative layer includes carbon black and silica ;
The content of the carbon black in the entire decoration layer is 1 to 30% by mass,
The content of the silica in the entire decoration layer is 1 to 30% by mass,
The thickness of the first decorative layer is 1 to 4 μm,
The thickness of the second decorative layer is 1 to 4 μm,
Each of the first decorative layer and the second decorative layer is a battery packaging material having a resin ratio of 60% by mass or more. The battery packaging material according to claim 1, wherein a ratio of the silica in the first decorative layer is 1 to 30% by mass. The battery packaging material according to claim 1 or 2, wherein the first decorative layer contains 1 to 30% by mass of the carbon black .   The battery packaging material according to claim 1, wherein a ratio of the resin in the first decorative layer is 65% by mass or more. The battery packaging material according to any one of claims 1 to 4, wherein a ratio of the silica in the second decorative layer is 1 to 30% by mass. The battery packaging material according to any one of claims 1 to 5, wherein the second decorative layer contains 1 to 30% by mass of the carbon black .   The battery packaging material according to any one of claims 1 to 6, wherein a ratio of the resin in the second decorative layer is 65% by mass or more.   The battery packaging material according to any one of claims 1 to 7, wherein the resin forming the decorative layer is a two-component curable resin. The battery packaging material according to any one of claims 1 to 8 , wherein the metal layer is formed of an aluminum foil. 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 9 battery.