JP2017157369A - Method of producing battery packaging material and wound body of battery packaging material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of producing a battery packaging material in which appearance failure hardly occurs.SOLUTION: Disclosed is a method of producing a battery packaging material, in which at least a base material layer, a colored adhesive layer, a metal layer and a thermally adhesive resin layer are laminated. In a step of laminating the base material layer and the metal layer via the adhesive layer by a dry lamination method, after forming the adhesive layer by coating an adhesive containing a coloring material on the surface of one side of the base material layer, the adhesive layer and the metal layer are laminated.SELECTED DRAWING: None

Description

  The present invention relates to a method for manufacturing a battery packaging material that is less likely to cause a poor appearance and a wound body of the battery packaging material.

  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, as a battery packaging material that can be easily processed into various shapes and can be made thinner and lighter, it is a film-like material in which a base material layer / adhesive layer / metal layer / heat-sealable resin layer are sequentially laminated. A laminated body has been proposed (see, for example, Patent Document 1). Such a film-shaped battery packaging material is formed so that the battery element can be sealed by causing the heat-fusible resin layers to face each other and heat-sealing the peripheral edge portion by heat sealing.

  In the final process of manufacturing a battery using such a battery packaging material, a label on which the product information is written is affixed on the surface of the battery, or product information etc. is directly printed on the surface instead of the label. May be printed. Similarly, in the manufacturing process of the battery packaging material, an identification mark may be attached to the surface on the outermost layer side.

  By attaching an identification mark to the surface of the battery or the battery packaging material, for example, a regular product and a counterfeit product can be distinguished. However, when the identification mark is counterfeited and attached, it is difficult to discriminate between a genuine product and a counterfeit product.

  Conventionally, as a method for solving such a problem, for example, a method for discriminating between a genuine product and a counterfeit product using a hologram label as an identification mark has been proposed. However, the hologram label increases the cost of the product, and the hologram label may be forged.

  Moreover, in various packaging materials formed by the laminates as described above, ink is printed on the back surface of the base material layer to form barcodes, patterns, characters, etc. A method of giving an identification mark by a method of laminating an adhesive and a metal foil (generally called back printing) is also conceivable. However, when such a printing surface exists between the base material layer and the metal layer, the adhesion between the base material layer and the metal layer is lowered, and delamination is likely to occur between the layers. In particular, since high safety is required for a battery to which the battery packaging material is applied, such a method of printing by back-printing is avoided in the battery packaging material.

  Under such circumstances, for example, Patent Document 2 includes a multilayer film having a structure in which at least a base material layer, an adhesive layer, a metal foil layer, and a thermal adhesive resin layer are laminated in this order. A method of including an identification mark in any one of a layer, an adhesive layer, and a metal foil layer is disclosed.

JP 2008-287971 A JP 2011-54563 A

  However, when the present inventors examined, in the technique of providing an identification mark by the method disclosed in Patent Document 2, the function as a battery packaging material is not impaired, but an appearance defect may occur. It was revealed. More specifically, when the adhesive layer is colored using a colorant in the laminate constituting the battery packaging material, the base material layer and the adhesive layer formed in the process of manufacturing the battery packaging material It was found that bubbles (for example, bubbles having a diameter of 0.5 mm or more when viewed from the base material layer side) were recognized from the appearance of the battery, resulting in poor appearance. In particular, when the adhesive layer is colored with a dark colorant such as black, the problem has been found that the bubbles are easily recognized and the appearance is frequently deteriorated.

  On the production line, battery packaging materials are generally manufactured as a strip-like laminated film with a length of several hundreds to thousands of meters, and are stored, transported, etc. as a wound body wound up in a roll shape. The For this reason, if even one bubble having an appearance defect is present in the wound body, it is necessary to cut and join the portions where the bubbles are present, which decreases the yield.

  Under such circumstances, a main object of the present invention is to provide a method for producing a packaging material for a battery that is less likely to cause an appearance defect.

  The present inventors have intensively studied to solve the above problems. As a result, at least a method for producing a battery packaging material in which a base material layer, a colored adhesive layer, a metal layer, and a heat-fusible resin layer are laminated, the base material layer and the metal In the step of laminating a layer with the adhesive layer by a dry lamination method, an adhesive layer containing a colorant is applied to one surface of the base material layer to form an adhesive layer, and then the adhesion It has been found that by using a method for producing a battery packaging material that includes a step of laminating an agent layer and the metal layer, a battery packaging material that is less likely to cause poor appearance is obtained. The present invention has been completed by further studies based on these findings.

That is, this invention provides the invention of the aspect hung up below.
Item 1. At least a method for producing a battery packaging material in which a base material layer, a colored adhesive layer, a metal layer, and a heat-fusible resin layer are laminated,
In the step of laminating the base material layer and the metal layer by the dry lamination method through the adhesive layer, an adhesive layer containing a colorant is applied to the surface of one side of the base material layer to form an adhesive layer After forming, the manufacturing method of the packaging material for batteries which has the process of laminating | stacking the said adhesive bond layer and the said metal layer.
Item 2. Item 2. The method for producing a battery packaging material according to Item 1, wherein the colorant is black.
Item 3. Item 3. The method for producing a battery packaging material according to Item 1 or 2, wherein the adhesive is a polyurethane two-component curable adhesive.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the packaging material for batteries which cannot produce the appearance defect easily can be provided. Furthermore, according to this invention, the winding body of the packaging material for batteries by which the external appearance defect was reduced can be provided.

It is a schematic sectional drawing which shows an example of the cross-sectional structure of the packaging material for batteries obtained by the manufacturing method of this invention. It is a schematic sectional drawing which shows an example of the cross-sectional structure of the packaging material for batteries obtained by the manufacturing method of this invention.

1. Method for producing battery packaging material The method for producing a battery packaging material of the present invention is for a battery in which at least a base material layer, a colored adhesive layer, a metal layer, and a heat-fusible resin layer are laminated. A method for manufacturing a packaging material, wherein in the step of laminating the base material layer and the metal layer by a dry lamination method through the adhesive layer, a colorant is included on one surface of the base material layer. It has the process of laminating | stacking the said adhesive bond layer and the said metal layer, after apply | coating an adhesive agent and forming an adhesive bond layer. Hereafter, the manufacturing method of the packaging material for batteries of this invention is explained in full detail.

  As shown in FIG. 1, the battery packaging material produced by the method for producing a battery packaging material of the present invention includes at least a base material layer 1, an adhesive layer 2, a metal layer 3, and a heat-fusible resin layer. 4 consists of the laminated body laminated | stacked one by one. In the battery packaging material, the base material layer 1 is the outermost layer, and the heat-fusible resin layer 4 is the innermost layer. That is, at the time of battery assembly, the heat-fusible resin 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. 2, an adhesive layer 5 may be provided between the metal layer 3 and the heat-fusible resin layer 4 as necessary for the purpose of improving these adhesive properties.

  In the method for producing a battery packaging material of the present invention, a step of bonding the base material layer 1 and the metal layer 3 via the adhesive layer 2 is performed by a dry lamination method. In the present invention, after the adhesive layer 2 is formed by applying an adhesive containing a coloring material to the surface of one side of the base material layer 1 in the bonding step, the adhesive layer 2 and the metal layer 3 are combined. Glue.

In the dry lamination method, in the step of applying an adhesive containing a coloring material to the surface of one side of the base material layer 1, the adhesive is applied to the surface of the base material layer 1 by a coating method such as a gravure coating method or a roll coating method. The adhesive layer 2 is formed by coating. For this reason, air bubbles are not substantially formed between the base material layer 1 and the adhesive layer 2. Next, the metal layer 3 is laminated | stacked on the adhesive bond layer 2, and the laminated body by which the base material layer 1 / adhesive layer 2 / metal layer 3 was laminated | stacked in order is obtained. When the metal layer 3 is laminated on the adhesive layer 2, bubbles are easily formed at the interface between the adhesive layer 2 and the metal layer 3. For this reason, even in the battery packaging material produced by the production method of the present invention, for example, when the area of the battery packaging material is 1 m ² or more, the interface between the adhesive layer 2 and the metal layer 3 has a diameter of 0. There may be bubbles of 5 mm or more. However, the position in the stacking direction where the bubbles exist is limited to the interface between the metal layer 3 and the adhesive layer 2.

  Thus, in the production method of the present invention, bubbles generated by the dry lamination method can be formed at the interface between the adhesive layer 2 and the metal layer 3, but at the interface between the base material layer 1 and the adhesive layer 2. , Not substantially formed. Furthermore, in the manufacturing method of the present invention, since the adhesive layer 2 contains a colorant, the interface between the adhesive layer 2 and the metal layer 3 when the battery packaging material is observed from the base material layer 1 side. It is suppressed that the bubble located in is recognized by visual observation. For this reason, by adopting the method for producing a battery packaging material of the present invention, appearance defects such as color unevenness due to bubbles are effectively suppressed.

  The dry lamination method in the production method of the present invention includes a step of applying an adhesive containing a coloring material to the surface of one side of the base material layer 1 and then drying it. Although it does not restrict | limit especially as heating temperature in a drying process, For example, 40 degreeC or more and 150 degrees C or less are mentioned. Moreover, as drying time, 3 second or more and 20 second or less are mentioned, for example.

  In the production method of the present invention, after obtaining a laminate in which the base layer 1 / adhesive layer 2 / metal layer 3 are laminated in order (hereinafter also referred to as “laminate A”), the metal By laminating the adhesive layer 5 and the heat-fusible resin layer 4 formed as necessary on the layer 3, the base layer 1 / adhesive layer 2 / metal layer 3 / formed as necessary. Thus, a battery packaging material in which the adhesive layer 5 / the heat-fusible resin layer 4 are sequentially laminated is obtained.

  As a method of laminating the heat-fusible resin layer 4 on the metal layer 3 of the laminate A, the following method may be mentioned. When directly laminating the heat-fusible resin layer 4 on the metal layer 3, the resin component constituting the heat-fusible resin layer 4 is applied to the metal layer 3 of the laminate A by a gravure coating method or a roll coating method. What is necessary is just to apply | coat by methods, such as. When the adhesive layer 5 is provided between the metal layer 3 and the heat-fusible resin layer 4, for example, (1) the adhesive layer 5 and the heat-fusible resin layer on the metal layer 3 of the laminate A 4 by co-extrusion (coextrusion lamination method), (2) Separately, a laminated body in which the adhesive layer 5 and the heat-fusible resin layer 4 are laminated is formed, and this is formed into a metal layer of the laminated body A (3) Extruding the adhesive for forming the adhesive layer 5 on the metal layer 3 of the laminate A, or drying and baking at a high temperature after solution coating. A method of laminating and laminating the heat-fusible resin layer 4 previously formed into a sheet on the adhesive layer 5 by a thermal lamination method, and (4) forming the metal layer 3 of the laminate A and a sheet in advance. While pouring the melted adhesive layer 5 between the heat-fusible resin layer 4, Sealable layer 5 method of bonding the laminate A and the heat-fusible resin layer 4 through the (sand lamination method) and the like. In addition, in order to strengthen the adhesiveness of the adhesive layer 2 and the adhesive layer 5 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 ° C. or more and 250 ° C. or less and 1 minute or more and 5 minutes or less.

  In the battery packaging material, each layer constituting the laminate is improved or stabilized as necessary, for example, film forming property, lamination processing, final product secondary processing (pouching, embossing) suitability, etc. Surface activation treatment such as corona treatment, blast treatment, oxidation treatment, and ozone treatment may be performed.

Composition of each layer forming base material for battery [base material layer 1]
In the battery packaging material, the base material layer 1 is a layer 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 can be laminated (multi-layer structure) of at least one of resin films and coatings of different materials in order to improve pinhole resistance and insulation when used as a battery packaging. is there. Specific examples include a multilayer structure in which a polyester film and a nylon film are laminated, a multilayer structure in which a plurality of nylon films are laminated, a multilayer structure in which a plurality of polyester films are laminated, and the like. When the base material layer 1 has a multilayer structure, a laminate of a biaxially stretched nylon film and a biaxially stretched polyester film, a laminate of a plurality of biaxially stretched nylon films, and a laminate of a plurality of biaxially stretched polyester films The body is preferred. For example, when the base material layer 1 is formed from two resin films, a polyester resin / polyamide resin structure is preferable, and a polyethylene terephthalate / nylon structure is more preferable. In addition, since the biaxially stretched polyester is difficult to discolor when the electrolyte solution adheres to the surface, for example, the base material layer 1 has a multilayer structure of a laminate of a biaxially stretched nylon film and a biaxially stretched polyester film. The base material layer 1 is preferably a laminate having biaxially stretched nylon and biaxially stretched polyester in this order from the metal layer 2 side. When the base material layer 1 has a multilayer structure, the thickness of each layer is preferably 4 μm or more and 25 μm or less.

  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. Specific examples of the adhesive include those similar to the adhesive exemplified in the adhesive layer 2. Further, the thickness of the adhesive can be the same as that of the adhesive layer 2.

  In the present invention, a lubricant is preferably attached to the surface of the base material layer 1 from the viewpoint of improving the moldability of the battery packaging material. Although it does not restrict | limit especially as a lubricant, Preferably an amide type lubricant is mentioned. Specific examples of the amide-based lubricant include saturated fatty acid amide, unsaturated fatty acid amide, substituted amide, methylolamide, saturated fatty acid bisamide, unsaturated fatty acid bisamide, and the like. Specific examples of the saturated fatty acid amide include lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, hydroxy stearic acid amide and the like. Specific examples of the unsaturated fatty acid amide include oleic acid amide and erucic acid amide. Specific examples of the substituted amide include N-oleyl palmitate, N-stearyl stearate, N-stearyl oleate, N-oleyl stearate, N-stearyl erucamide, and the like. Specific examples of methylolamide include methylol stearamide. Specific examples of saturated fatty acid bisamides include methylene bis stearamide, ethylene biscapric amide, ethylene bis lauric acid amide, ethylene bis stearic acid amide, ethylene bishydroxy stearic acid amide, ethylene bisbehenic acid amide, hexamethylene bis stearic acid amide. Examples include acid amide, hexamethylene bisbehenic acid amide, hexamethylene hydroxystearic acid amide, N, N′-distearyl adipic acid amide, N, N′-distearyl sebacic acid amide, and the like. Specific examples of unsaturated fatty acid bisamides include ethylene bisoleic acid amide, ethylene biserucic acid amide, hexamethylene bisoleic acid amide, N, N′-dioleyl adipic acid amide, N, N′-dioleyl sebacic acid amide Etc. Specific examples of the fatty acid ester amide include stearoamidoethyl stearate. Specific examples of the aromatic bisamide include m-xylylene bis stearic acid amide, m-xylylene bishydroxy stearic acid amide, N, N′-cysteallyl isophthalic acid amide and the like. One type of lubricant may be used alone, or two or more types may be used in combination.

When the lubricant is present on the surface of the base material layer 1, the amount of the lubricant is not particularly limited, but it is preferably 3 mg / m ² or more, more preferably 4 mg / m ² or more and 15 mg at a temperature of 24 ° C. and a humidity of 60%. / M ² or less, more preferably 5 mg / m ² or more and 14 mg / m ² or less.

  As thickness of the base material layer 1, 10 micrometers or more and 50 micrometers or less, for example, Preferably 15 micrometers or more and 30 micrometers or less are mentioned.

[Adhesive layer 2]
In the battery packaging material, the colored adhesive layer 2 is a layer that bonds the base material layer 1 and the metal layer 3 and serves as an identification mark of the battery or the battery packaging material. For example, it is possible to determine whether the battery or the battery packaging material is a genuine product or a counterfeit product based on the color of the colorant contained in the adhesive layer 2.

  The adhesive layer 2 can bond the base material layer 1 and the metal layer 3 and is formed of an adhesive containing a coloring material. The adhesive used for forming the adhesive layer 2 may be a two-component curable adhesive or a one-component curable adhesive. Furthermore, the bonding 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. 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 Polyolefin resins such as: polyvinyl acetate resins; cellulose adhesives; (meth) acrylic resins; polyimide resins; amino resins such as urea resins and melamine resins; chloroprene rubber, nitrile rubber, steel Silicone resin; - down rubber such as butadiene rubber fluorinated ethylene propylene copolymer, and the like. These adhesive components may be used individually by 1 type, and may be used in combination of 2 or more type. The combination mode of two or more kinds of adhesive components is not particularly limited. For example, as the adhesive component, a mixed resin of polyamide and acid-modified polyolefin, a mixed resin of polyamide and metal-modified polyolefin, polyamide and polyester, Examples thereof include a mixed resin of polyester and acid-modified polyolefin, and a mixed resin of polyester and metal-modified polyolefin. Among these, extensibility, durability under high-humidity conditions, anti-hypertensive action, 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 colorant is not particularly limited, and preferably includes a chromatic color pigment or an inorganic color pigment. Examples of chromatic coloring pigments include azo pigments, phthalocyanine pigments, and condensed polycyclic pigments, and azo pigments include soluble pigments such as Loching Red and Carmine 6C, monoazo yellow, disazo yellow, and pyrazolone orange. Insoluble azo pigments such as red and permanent red, copper phthalocyanine pigments as phthalocyanine pigments, blue and green pigments as metal-free phthalocyanine pigments, and dioxazine violet and quinacridone violet as condensed polycyclic pigments . Examples of inorganic color pigments include titanium oxide and carbon black.

Examples of the colorant include pearl pigments and fluorescent pigments. As the pearl pigment, pearl powder or powder inside the shell is used classically. At present, the outer side of fine flakes (flakes) coated with a metal oxide or a mixture of metal oxides is widely used. Fine flakes include mica, talc, kaolin, bismuth oxychloride, glass flakes, SiO ₂ flakes, synthetic ceramic flakes, and the like. Examples of the metal oxide covering the outside of these fine flakes include TiO ₂ , Fe ₂ O ₃ , SnO ₂ , Cr ₂ O ₃ and ZnO. Among these combinations, mica, glass flakes, or SiO ₂ flakes coated with TiO ₂ and / or Fe ₂ O ₃ are preferable.

The fluorescent pigment may be a fluorescent substance, that is, a substance that emits luminescence in a broad sense. Fluorescent pigments include both inorganic fluorescent pigments and organic fluorescent pigments, and inorganic fluorescent pigments include oxides such as Ca, Ba, Mg, Zn, and Cd, sulfides, silicates, phosphates, and tungstic acids. Preference is given to pigments which are obtained by firing with a crystal such as a salt as a main component, a metal element such as Mn, Zn, Ag, Cu, Sb and Pb or a rare earth element such as a lanthanoid as an activator. As preferred inorganic fluorescent pigments, ZnO: Zn, Br ₅ (PO ₄ ) ₃ Cl: Eu, Zn ₂ GeO ₄ : Mn, Y ₂ O ₃ : Eu, Y (P, V) O ₄ : Eu, Y ₂ O ₂ Examples thereof include Si: Eu and Zn ₂ GeO ₄ : Mn. Preferred organic fluorescent pigments include diaminostilbene disulfonic acid derivatives, imidazole derivatives, coumarin derivatives, derivatives of triazole, carbazole, pyridine, naphthalic acid, imidazolone, dyes such as fluorescein and eosin, compounds having a benzene ring such as anthracene, etc. Can be illustrated.

  A coloring material may be used individually by 1 type, and may be used in combination of 2 or more types.

  Among the colorants, dark colorants such as black are preferable. When the adhesive layer is colored with a dark colorant, bubbles having a diameter (diameter as viewed from the base material layer 1 side) of 0.5 mm or more exist at the interface between the base material layer and the adhesive layer, for example. Then, when viewed from the base material layer side, color unevenness and the like are recognized by the bubbles, and appearance defects occur. On the other hand, according to the method for manufacturing a battery packaging material of the present invention, since bubbles of such a size are not substantially formed at the interface between the base material layer 1 and the adhesive layer 2, a dark colorant Also when using, the appearance defects can be effectively suppressed. Further, by coloring the adhesive layer 2 with a dark colorant, bubbles present at the interface between the adhesive layer 2 and the metal layer 3 are recognized when visually observed from the base material layer 1 side. Therefore, according to the present invention, it is possible to effectively suppress the appearance failure.

  It does not restrict | limit especially as content of the coloring material in the adhesive bond layer 2, For example, 5 to 30 mass%, More preferably, 10 to 25 mass% is mentioned.

  Further, 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. It is preferable to select a resin excellent in adhesiveness to 1, and to select an adhesive component excellent in adhesiveness to 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 acid-modified polyolefin, metal-modified polyolefin, polyester and acid-modified polyolefin. And mixed resins, resins containing copolymerized polyesters, and the like.

  About the thickness of the adhesive bond layer 2, 2 micrometers or more and 50 micrometers or less, for example, Preferably they are 3 micrometers or more and 25 micrometers or less.

[Metal layer 3]
In the battery packaging material, the metal layer 3 is a layer that functions as a barrier layer for preventing moisture, oxygen, light, and the like from entering 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, as the metal layer 3 in the present invention, soft aluminum, for example, annealed aluminum (JIS H4160: 1994 A8021H-O, JIS H4160: 1994 A8079H-O, JIS H4000: 2014 A8021P-O, JIS H4000: 2014 A8079P-O) and the like are preferably used.

  About the thickness of the metal layer 3, 10 micrometers or more and 200 micrometers or less, for example, Preferably they are 20 micrometers or more and 100 micrometers or less.

  Further, the metal layer 3 is subjected to chemical conversion treatment on at least one surface, preferably at least the surface on the side of the heat-fusible resin layer 4, more preferably both surfaces in order to stabilize adhesion, prevent dissolution and corrosion, and the like. Preferably it is. 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 a phosphoric acid compound 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- C1-C4 linear or branched chain in which one hydroxy group such as hydroxypropyl group, 1-hydroxybutyl group, 2-hydroxybutyl group, 3-hydroxybutyl group, 4-hydroxybutyl group is substituted An alkyl group is mentioned. In the general formulas (1) to (4), 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 comprising the repeating units represented by the general formulas (1) to (4) is, for example, about 500 or more and about 1,000,000 or less, preferably about 1000 or more and about 20,000 or less. .

  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 is 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 above chromate treatment is performed, a chromic acid compound is present per 1 m ² of the surface of the metal layer 2. About 0.5 mg to about 50 mg in terms of chromium, preferably about 1.0 mg to about 40 mg, phosphorus compound in terms of phosphorus, about 0.5 mg to about 50 mg, preferably about 1.0 mg to about 40 mg, and It is desirable that the aminated phenol polymer is contained in an amount of about 1 mg to about 200 mg, preferably about 5.0 mg 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 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 70 ° C. or higher and 200 ° C. or lower. 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.

[Heat-fusion resin layer 4]
In the battery packaging material, the heat-fusible resin layer 4 corresponds to the innermost layer, and is a layer that heat-welds the heat-fusible resin layers to each other to seal the battery element when the battery is assembled.

  The resin component used for the heat-fusible resin layer 4 is not particularly limited as long as it can be heat-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 heat-fusible resin 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 heat-fusible resin 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 heat-fusible resin layer 4 may contain a lubricant or the like as necessary. When the heat-fusible resin layer 4 contains a lubricant, the moldability of the battery packaging material can be improved. The lubricant is not particularly limited, and a known lubricant can be used, and examples thereof include those exemplified in the base material layer 1 described above. One type of lubricant may be used alone, or two or more types may be used in combination.

  The thickness of the heat-fusible resin layer 4 can be selected as appropriate, and is 10 μm or more and 100 μm or less, preferably 15 μm or more and 50 μm or less.

[Adhesive layer 5]
In the battery packaging material, the adhesive layer 5 is a layer provided between the metal layer 3 and the heat-fusible resin layer 4 as necessary in order to firmly bond the metal layer 3 and the heat-fusible resin layer 4.

  The adhesive layer 5 is formed of an adhesive capable of bonding the metal layer 3 and the heat-fusible resin layer 4. With respect to the adhesive used for forming the adhesive layer 5, 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 5 is preferably a polyolefin resin, more preferably a carboxylic acid-modified polyolefin, particularly preferably a carboxylic acid-modified polypropylene.

  The thickness of the adhesive layer 5 is, for example, 2 μm or more and 50 μm or less, preferably 15 μm or more and 30 μm or less.

Application of Battery Packaging Material The battery packaging material produced by the production method 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. By covering the periphery of the element so that a flange portion (region where the heat-fusible resin layers are in contact with each other) can be formed, and heat-sealing the heat-fusible resin layers of the flange portion to seal the battery A battery using the packaging material is provided. In addition, when accommodating a battery element using the battery packaging material of the present invention, the battery packaging material is used such that the sealant portion is on the inner side (surface in contact with the battery element).

  Since the battery packaging material of the present invention is used for the battery of the present invention, the ink is suitably printed on the surface of the battery after the battery packaging material is molded and the battery element is sealed. Can do. That is, for example, the ink can be suitably printed by pad printing in which the ink is likely to be repelled in the base material layer having a lubricant on the surface, and at least a part of the surface of the battery, for example, a barcode, a handle, Printing of characters and the like can be suitably formed.

  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.

2. Winding body of battery packaging material The winding body of the battery packaging material of the present invention can be manufactured by the method for manufacturing a battery packaging material of the present invention described above. The wound body of the battery packaging material of the present invention is obtained by winding the aforementioned battery packaging material in a roll shape. That is, at least a base material layer 1, a colored adhesive layer 2, a metal layer 3, and a heat-fusible resin layer 4 are sequentially laminated in the wound body of the battery packaging material of the present invention. A winding body of a battery packaging material comprising a laminate, and the interface between the adhesive layer 2 and the metal layer 3 is not recognized when visually observed from the base material layer 1 side, and has a diameter of 0.5 mm. It is characterized by the presence of the above bubbles. The composition of each layer of the wound body of the battery packaging material of the present invention is as described above.

  As described above, in the production method of the present invention, bubbles generated by the dry lamination method can be formed at the interface between the adhesive layer 2 and the metal layer 3, but at the interface between the base material layer 1 and the adhesive layer 2. Bubbles visually recognized from the base material layer 1 such as a diameter of 0.5 mm or more are not substantially formed. Further, in the wound body of the battery packaging material of the present invention, since the adhesive layer 2 contains a coloring material, the adhesive layer 2 is also observed when the battery packaging material is observed from the base material layer 1 side. Bubbles located at the interface between the metal layer 3 and the metal layer 3 are not recognized visually. For this reason, in the wound body of the battery packaging material of the present invention, appearance defects such as color unevenness based on air bubbles are effectively suppressed.

  In the wound body of the present invention, the length of the laminate constituting the battery packaging material is not particularly limited, and is, for example, 200 m or more, preferably 200 m or more and 600 m or less. Moreover, the width | variety of the said laminated body is 0.01 m or more and 1 m or less, for example, Preferably 0.1 m or more and 1 m or less are mentioned. The thickness of the laminate is, for example, 200 μm or less, preferably 50 μm or more and 200 μm or less, more preferably 65 μm or more and 130 μm or less. In the roll-shaped winding body, the diameter of the circular cross section in the direction perpendicular to the width direction of the laminate is preferably 150 mm or more, more preferably 220 mm or more. In addition, the upper limit of the diameter of the circular section is usually about 350 mm. In addition, the wound body of the battery packaging material is usually wound around a core tube having a diameter of 80.2 mm or more and 100.2 mm or less.

  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
On the base material layer (15 μm) made of nylon resin, a metal layer made of aluminum foil (thickness 35 μm) subjected to chemical conversion treatment on both surfaces was laminated by a dry lamination method. Specifically, a polyurethane two-component curable adhesive (polyol compound and aromatic isocyanate compound) containing 18% by mass of carbon black as a colorant is applied to one surface of the base material layer, and the base material layer is coated on the base material layer. A black colored adhesive layer (thickness 3 μm) was formed. At this time, the adhesive was dried at 70 ° C. for 10 seconds. Subsequently, after laminating the adhesive layer and the metal layer on the base material layer, an aging treatment was performed at 40 ° C. for 24 hours to prepare a base material layer / adhesive layer / metal layer laminate. In addition, the chemical conversion treatment of the aluminum foil used as the metal layer is performed by roll coating a treatment liquid composed of a phenol resin, a chromium fluoride compound, and phosphoric acid so that the coating amount of chromium is 10 mg / m ² (dry weight). The coating was performed on both surfaces of the aluminum foil by the method and baked for 20 seconds under the condition that the film temperature was 180 ° C. or higher. Next, 20 μm of carboxylic acid-modified polypropylene (arranged on the metal layer side) and 15 μm of random polypropylene (innermost layer) are co-extruded on the metal layer of the laminate, so that an adhesive layer / heat-sealable resin is formed on the metal layer. The layers were laminated. The battery packaging material was obtained through the above steps.

Comparative Example 1
On the base material layer (15 μm) made of nylon resin, a metal layer made of aluminum foil (thickness 35 μm) subjected to chemical conversion treatment on both surfaces was laminated by a dry lamination method. Specifically, a polyurethane two-component curable adhesive (polyol compound and aromatic isocyanate compound) containing 18% by mass of carbon black as a colorant is applied to one side of the metal layer, and the black color is applied to the metal layer. A colored adhesive layer (thickness 3 μm) was formed. At this time, the adhesive was dried at 70 ° C. for 10 seconds. Next, after laminating the adhesive layer and the base material layer on the metal layer, an aging treatment is carried out at 40 ° C. for 24 hours to prepare a base material layer / adhesive layer / metal layer / adhesive layer laminate. did. The method of chemical conversion treatment of the aluminum foil used as the metal layer is the same as that in Example 1. Next, in the same manner as in Example 1, the adhesive layer / heat-fusible resin layer was laminated on the metal layer to obtain a battery packaging material.

[Observation of appearance]
Each battery packaging material obtained above was visually observed from the base material layer side, and the number of bubbles having a diameter of 0.5 mm or more was counted. The observed range is 1 m ² . The results are shown in Table 1.

[Measurement of laminate strength]
Each battery packaging material obtained above was cut into a width of 15 mm, and at 20 ° C., after partially peeling off from the end face while applying ethyl acetate to the adhesive interface, it was measured at a tensile speed of 50 mm / min with Tensilon, The average strength at that time was defined as the laminate strength. The results are shown in Table 1.

DESCRIPTION OF SYMBOLS 1 Base material layer 2 Adhesive layer 3 Metal layer 4 Heat-fusible resin layer 5 Adhesive layer

Claims (3)

At least a method for producing a battery packaging material in which a base material layer, a colored adhesive layer, a metal layer, and a heat-fusible resin layer are laminated,
In the step of laminating the base material layer and the metal layer by the dry lamination method through the adhesive layer, an adhesive layer containing a colorant is applied to the surface of one side of the base material layer to form an adhesive layer After forming, the manufacturing method of the packaging material for batteries which has the process of laminating | stacking the said adhesive bond layer and the said metal layer.   The manufacturing method of the packaging material for batteries of Claim 1 whose said coloring material is black.   The method for producing a battery packaging material according to claim 1 or 2, wherein the adhesive is a polyurethane two-component curable adhesive.