JP6024386B2 - Exterior materials for lithium-ion batteries - Google Patents

Description

  The present invention relates to a packaging material for a lithium ion battery.

  Since secondary batteries are indispensable for miniaturization due to miniaturization of portable devices, installation space limitations, and the like, lithium ion batteries having higher energy density than nickel metal hydride and lead storage batteries have attracted attention. As a lithium-ion battery exterior material (hereinafter sometimes referred to simply as “exterior material”), it is a multilayer film that is lighter, has higher heat dissipation than conventional metal cans, and can be handled at low cost. The outer packaging material is widely used. As such an exterior material, for example, an exterior material in which a base material layer / first adhesive layer / aluminum foil layer / corrosion prevention treatment layer / second adhesive layer / sealant layer for preventing corrosion due to hydrofluoric acid is sequentially laminated. Are known.

  As a lithium ion battery using the outer packaging material, for example, a concave portion is formed by cold molding in one part when the outer packaging material is folded in half, and a positive electrode, a separator, a negative electrode, an electrolytic solution, etc. are formed in the concave portion. It is known that the battery contents are placed, the remaining part is folded, and the edge part is heat sealed. In recent years, in order to efficiently store more battery contents and increase the energy density, lithium ion batteries in which recesses are formed on both sides of the exterior material to be bonded have also been manufactured.

  In order to increase the energy density of a lithium ion battery, it is important to deepen the recess formed by cold forming and increase the amount of battery contents accommodated in the recess. Therefore, a nylon film excellent in moldability is widely used for the base material layer. However, since the nylon film has low electrolyte solution resistance, if the electrolyte solution adheres to the base material layer during battery production or use, the base material layer may be dissolved and the aluminum foil layer may be corroded. In addition, since the nylon film has low scratch resistance, the surface of the base material layer may be damaged when handled, and the designability, durability, and the like may be reduced.

As an exterior material with improved resistance to electrolyte solution on the base material layer side, for example, on the outside of the base material layer made of nylon film, polyvinylidene chloride, vinylidene chloride-vinyl chloride copolymer, maleic anhydride-modified polypropylene, polyester resin An exterior material in which at least one coating layer selected from the group consisting of an epoxy resin, a phenol resin, a fluororesin, a cellulose ester, a urethane resin and an acrylic resin is formed is known (Patent Document 1).
However, although the exterior material of Patent Document 1 can provide sufficient electrolytic solution resistance, it is difficult to obtain sufficient scratch resistance particularly for in-vehicle use.
In addition, when a layer that protects the base material layer is formed outside the base material layer, the adhesion between the layer and the base material layer is good, and the stretchability and moldability are sufficiently high. It is required that liquid resistance can be maintained.

Japanese Patent No. 3567229

  The present invention has high adhesion to the base material layer, has sufficient scratch resistance and electrolyte solution resistance, has excellent stretchability and moldability, and can maintain the electrolyte solution resistance after stretching. Provided is a lithium ion battery exterior material having a layer.

The exterior material for a lithium ion battery of the present invention includes a base material layer made of a nylon film,
A first adhesive layer provided on the first surface side of the base material layer;
A metal foil layer provided on the opposite side of the base layer of the first adhesive layer;
A corrosion prevention treatment layer provided on the opposite side of the metal foil layer from the first adhesive layer;
A second adhesive layer provided on the opposite side of the corrosion prevention treatment layer from the metal foil layer;
A sealant layer provided on the opposite side of the corrosion prevention treatment layer of the second adhesive layer;
A base material protective layer provided on the second surface side of the base material layer,
The substrate protective layer contains at least one selected from the group consisting of cellulose and cellulose derivatives, and selected from the group consisting of the following water-soluble polymer (B), plasticizer (C) and surfactant (D). characterized in that it contains at least one member.
Water-soluble polymer (B): At least one solvent 100 selected from the group consisting of an aqueous alcohol solution containing 50% by mass of methanol, ethanol, propanol or isopropyl alcohol at 85 ° C., other than polysaccharides, and water A compound having a molecular weight of 10,000 or more that dissolves 1 part by mass or more with respect to parts by mass.

The exterior material for a lithium ion battery of the present invention includes a base material layer made of a nylon film,
A first adhesive layer provided on the first surface side of the base material layer;
A metal foil layer provided on the opposite side of the base layer of the first adhesive layer;
A corrosion prevention treatment layer provided on the opposite side of the metal foil layer from the first adhesive layer;
A second adhesive layer provided on the opposite side of the corrosion prevention treatment layer from the metal foil layer;
A sealant layer provided on the opposite side of the corrosion prevention treatment layer of the second adhesive layer;
A third adhesive layer provided on the second surface side of the base material layer;
A base material protective layer provided on the side opposite to the base material layer of the third adhesive layer,
The substrate protective layer contains at least one selected from the group consisting of cellulose and cellulose derivatives, and is selected from the group consisting of the water-soluble polymer (B), plasticizer (C) and surfactant (D). Containing at least one selected from the group consisting of

  The third adhesive layer is at least one selected from the group consisting of phenol resin, urea resin, melamine resin, polyvinyl resin, polyolefin resin, urethane resin, epoxy resin, acrylic resin, polyester resin, polyamide resin, and polystyrene resin. It is preferable that the adhesive resin (E) is contained.

  The plasticizer (C) is a phthalate ester plasticizer, an aromatic carboxylic ester plasticizer, an aliphatic dibasic ester plasticizer, an aliphatic ester plasticizer, a phosphate ester plasticizer, or an epoxy. It is preferably at least one selected from the group consisting of a plasticizer, a chlorine-containing plasticizer, a polyester plasticizer, a glycol plasticizer and a sugar alcohol plasticizer.

  The outer packaging material for a lithium ion battery of the present invention has high adhesion to the base material layer, sufficient scratch resistance, electrolyte solution resistance, excellent stretchability and moldability, and the electrolyte solution after stretching. It has the base material protective layer which can maintain tolerance.

It is sectional drawing which showed an example of the exterior material for lithium ion batteries of this invention. It is sectional drawing which showed the other example of the exterior material for lithium ion batteries of this invention.

<First Embodiment>
Hereinafter, an example of the outer packaging material for a lithium ion battery of the present invention will be shown and described in detail.
As shown in FIG. 1, the lithium ion battery exterior material 1 (hereinafter simply referred to as “exterior material 1”) of the present embodiment is disposed on the base layer 11 and the first surface 11 a side of the base layer 11. The first adhesive layer 12 provided, the metal foil layer 13 provided on the opposite side of the base material layer 11 of the first adhesive layer 12, and the first foil 12 provided on the opposite side of the first adhesive layer 12 Corrosion prevention treatment layer 14, second adhesive layer 15 provided on the opposite side of corrosion prevention treatment layer 14 to metal foil layer 13, and sealant provided on the opposite side of corrosion prevention treatment layer 14 of second adhesion layer 15. A layer 16, a third adhesive layer 17 provided on the second surface 11b side of the base material layer 11, a base material protective layer 18 provided on the opposite side of the third adhesive layer 17 from the base material layer 11, Have That is, the exterior material 1 includes a base material protective layer 18, a third adhesive layer 17, a base material layer 11, a first adhesive layer 12, a metal foil layer 13, a corrosion prevention treatment layer 14, a second adhesive layer 15, and a sealant layer 16. Is a laminated body laminated in this order.
When the exterior material 1 is used for a battery, the base material protective layer 18 is used as the outside, and the sealant layer 16 is used as the inside.

(Base material protective layer)
The base material protective layer 18 protects the base material layer 11 and plays a role of suppressing the base material layer 11 from being deteriorated or damaged by the electrolytic solution.
The base material protective layer 18 contains a water-soluble polysaccharide (A) and contains at least one selected from the group consisting of a water-soluble polymer (B), a plasticizer (C) and a surfactant (D). To do. When the base material protective layer 18 contains the water-soluble polysaccharide (A), good scratch resistance and electrolytic solution resistance can be obtained. The base material protective layer 18 contains at least one selected from the group consisting of a water-soluble polymer (B), a plasticizer (C), and a surfactant (D), so that excellent stretchability and moldability are achieved. Can be obtained, and excellent resistance to the electrolytic solution can be maintained even after stretching.

The water-soluble polysaccharide (A) is at 85 ° C. with respect to 100 parts by mass of at least one solvent selected from the group consisting of an aqueous alcohol solution containing 50% by mass of methanol, ethanol, propanol or isopropyl alcohol, and water. And 1 part by mass or more of the polysaccharide.
In the present invention, the dissolution of the polysaccharide includes not only the dissolved state in which the polysaccharide is completely molecularly dispersed but also that the polysaccharide is swollen or dispersed to show a uniform dissolved state.

Examples of the water-soluble polysaccharide (A) include cellulose derivatives such as cellulose, chitin, and carboxymethylcellulose, chitin derivatives such as chitosan, amylose, amylopectin, dextran, pullulan, erucinan, sodium alginate, agar, guar gum, pectin, and tamarind gum. And xanthan gum.
A water-soluble polysaccharide (A) may be used individually by 1 type, and may use 2 or more types together.

The water-soluble polysaccharide (A) is particularly preferably cellulose having a regular structural arrangement and a rigid skeleton due to the development of intramolecular hydrogen bonds or intermolecular hydrogen bonds. Cellulose is known to have an extremely low linear expansion coefficient, and excellent moldability can be obtained due to the low linear expansion coefficient. Examples of the cellulose raw material include wood pulp, non-wood pulp, cotton, and bacterial cellulose. The fiber width of cellulose is preferably 2 to 200 nm and the length is preferably 0.5 to 50 μm. If the fiber width and length of the cellulose are within this range, a uniform and transparent cellulose aqueous dispersion can be prepared. In addition, about the fiber width and length of a cellulose, about 0.001 mass% aqueous dispersion is cast on glass or mica, and it dries, and uses a transmission electron microscope (TEM) or an atomic force microscope (AFM). It can be obtained by observing.
The aqueous dispersion of cellulose used for forming the base material protective layer 18 is obtained by subjecting cellulose to mechanical treatment in water and making it finer. The mechanical treatment is not particularly limited, and examples thereof include treatment using a mixer, a high-pressure homogenizer, an ultrasonic homogenizer, grinder grinding, freeze grinding, media mill, and the like. Moreover, you may chemically-process a cellulose as a pre-process which performs a mechanical process.

  More preferably, the cellulose is crystalline cellulose. When the crystallinity of cellulose is high, the high modulus of elasticity of the base material protective layer 18 is maintained, and the electrolytic solution resistance and heat resistance are improved. As a method for obtaining an aqueous dispersion of highly crystalline cellulose, TEMPO oxidized cellulose obtained by chemically treating cellulose using 2,2,6,6-tetramethyl-1-pipedinyloxy radical (TEMPO) as a catalyst is used. A method is mentioned. An aqueous dispersion of TEMPO-oxidized cellulose has a feature that the pigment dispersibility is good when a pigment is added. Furthermore, since the aqueous dispersion of TEMPO-oxidized cellulose has high transparency of the dispersion, excellent design properties can be obtained. In addition, the aqueous dispersion of TEMPO-oxidized cellulose is excellent in coatability.

TEMPO oxidized cellulose is obtained, for example, by the chemical treatment shown below.
A nitroxy radical and sodium bromide (bromide) are added to cellulose dispersed in water, and an aqueous solution of sodium hypochlorite (oxidant) is added with stirring at room temperature to oxidize the cellulose. An alkaline solution such as sodium hydroxide is added during the oxidation reaction to control the pH in the reaction system to 9-11. At this time, the hydroxyl group at the C6 position on the surface of the cellulose fiber is oxidized to a carboxyl group, and TEMPO oxidized cellulose is obtained. After the treatment, it is sufficiently washed with water, and the obtained TEMPO-oxidized cellulose is dispersed in water in a fibrous form, and the solid content concentration is appropriately adjusted, which can be used as a constituent material of the aqueous dispersion.
As the oxidizing agent, hypohalous acid or a salt thereof, halogenous acid or a salt thereof can be used, and sodium hypochlorite is preferable.
Examples of the bromide include lithium bromide, potassium bromide, sodium bromide and the like, and sodium bromide is preferable.

The degree of polymerization of the water-soluble polysaccharide (A) is preferably from 100 to 800, more preferably from 250 to 400. If the degree of polymerization of the water-soluble polysaccharide (A) is at least the lower limit, the electrolyte solution is excellent in resistance to hydrofluoric acid generated by reacting with water. If the polymerization degree of water-soluble polysaccharide (A) is below an upper limit, the workability of the exterior material 1 will become favorable.
The degree of polymerization of the water-soluble polysaccharide (A) is measured by a viscosity method using a copper ethylenediamine solution.

  Only 1 type may be used for water-soluble polysaccharide (A), and 2 or more types may be used together. For example, by using TEMPO oxidized cellulose and starch, and TEMPO oxidized cellulose and hydroxypropyl cellulose in combination, stretchability and moldability can be further improved.

The substrate protective layer 18 may be one layer or two or more layers.
When the base material protective layer 18 is two or more layers, the degree of polymerization of the water-soluble polysaccharide (A) on the side opposite to the base material layer 11 is compared with the degree of polymerization of the water-soluble polysaccharide (A) on the base material layer 11 side. And high. Thereby, both the particularly excellent adhesion between the substrate protective layer 18 and the substrate layer 11 and the particularly excellent scratch resistance can be achieved.
The base material protective layer 18 in which the degree of polymerization of the water-soluble polysaccharide (A) on the opposite side of the base material layer 11 is higher than the degree of polymerization of the water-soluble polysaccharide (A) on the base material layer 11 side is, for example, Preparing a plurality of coating liquids containing different water-soluble polysaccharides (A), and coating and drying these coating liquids in order from the coating liquid containing water-soluble polysaccharides (A) having a low degree of polymerization. Can be formed.
For example, a layer containing a water-soluble polysaccharide (A) having a polymerization degree of 300, a layer containing a water-soluble polysaccharide (A) having a polymerization degree of 500, and a layer containing a water-soluble polysaccharide (A) having a polymerization degree of 700 Is a multilayer base material protective layer 18 or the like laminated in order from the base material layer 11 side.

The base material protective layer 18 preferably contains a water-soluble polymer (B). When the base material protective layer 18 contains the water-soluble polymer (B), particularly good stretchability can be obtained.
The water-soluble polymer (B) is at least one solvent selected from the group consisting of, in addition to polysaccharides, an aqueous alcohol solution containing 50% by mass of methanol, ethanol, propanol or isopropyl alcohol at 85 ° C., and water. It is a compound having a molecular weight of 10,000 or more that dissolves 1 part by mass or more with respect to 100 parts by mass.
In the present invention, the term “dissolving of a compound” includes not only the dissolving state in which the compound is completely molecularly dispersed but also the fact that the compound swells or disperses to show a uniform dissolving state.

The molecular weight of the water-soluble polymer (B) is preferably from 10,000 to 500,000, more preferably from 20,000 to 200,000. If the molecular weight of the water-soluble polymer (B) is at least the lower limit value, the base material protective layer 18 has good water resistance and heat resistance, and the film strength becomes strong. If the molecular weight of the water-soluble polymer (B) is not more than the upper limit value, the viscosity of the coating solution is suitable for coating.
The molecular weight of the water-soluble polymer (B) is a mass average molecular weight measured by the method described in JIS K6726.

Examples of the water-soluble polymer (B) include proteins, vinyl resins, acrylic resins, and polyethylene resins.
Examples of proteins include gelatin, casein, and sodium chondroitin sulfate.
Examples of the vinyl resin include polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl pyrrolidone / vinyl acetate copolymer, and the like.
Examples of the acrylic resin include sodium polyacrylate, carboxyvinyl polymer, polyacrylamide, acrylamide / acrylate copolymer, and the like.
Examples of the polyethylene resin include polyethyleneimine, polyethylene oxide, polyethylene glycol, and the like.
A water-soluble polymer (B) may be used individually by 1 type, and may use 2 or more types together.

The base material protective layer 18 preferably contains a plasticizer (C). By imparting plasticity to the base material protective layer 18 by the plasticizer (C), particularly good stretchability is obtained, and processability and moldability are increased.
As the plasticizer (C), phthalate ester plasticizer, aromatic carboxylate ester plasticizer, aliphatic dibasic ester plasticizer, aliphatic ester plasticizer, phosphate ester plasticizer, epoxy Examples thereof include plasticizers, chlorine-containing plasticizers, polyester-based plasticizers, glycol-based plasticizers, and sugar alcohol-based plasticizers.
Examples of the phthalate ester plasticizer include dimethyl phthalate, diethyl phthalate, diisobutyl phthalate, dibutyl phthalate, diisooctyl phthalate, dinonyl phthalate, diisodecyl phthalate, diundecyl phthalate, and ditridecyl phthalate.
Examples of the aromatic carboxylic acid ester plasticizer include trioctyl trimellitic acid, diethylene glycol dibenzoate, octyl oxybenzoate, and the like.
Examples of the aliphatic dibasic ester plasticizer include dioctyl succinate, diisodecyl succinate, dioctyl adipate, diisodecyl adipate, dioctyl azelate, dibutyl sebacate, dioctyl sebacate, and dioctyl tetrahydrophthalate.
Examples of the fatty acid ester plasticizer include butyl oleate, methyl acetylricinoleate, pentaerythritol ester, dipentaerythritol hexaester, and the like.
Examples of the phosphate ester plasticizer include tricresyl phosphate, trioctyl phosphate, octidiphenyl phosphate, triphenyl phosphate, trichloroethyl phosphate, and cresyl diphenyl phosphate.
Examples of the epoxy plasticizer include epoxidized soybean oil, epoxidized linseed oil, butyl epoxy stearate, octyl epoxy stearate, benzyl epoxy stearate, dioctyl epoxy hexahydrophthalate, and the like.
Examples of the chlorine-containing plasticizer include chlorinated paraffin, chlorinated diphenyl, chlorinated fatty acid methyl, and methoxychlorinated fatty acid methyl.
Examples of the polyester plasticizer include polypropylene adipate and polypropylene sebacate.
Examples of the glycol plasticizer include glycerin, diglycerin, polyglycerin, tylene glycol, triethylene glycol, hexamethylene glycol, polyethylene glycol, butyl phthalyl glycolate, triethylene glycol-2-ethyl butyrate, and the like. . Of these, polyglycerol (degree of polymerization of 5 to 10) is particularly preferable from the viewpoint of heat resistance and volatility.
The sugar alcohol plasticizer is a compound in which the aldehyde group of sugar is reduced and the terminal is changed to alcohol. Examples of the sugar alcohol plasticizer include sorbitol, maltitol, xylitol, erythritol, lactitol, mannitol, isomalt and the like. The base material protective layer 18 containing a sugar alcohol plasticizer is preferable because it easily maintains the resistance to electrolyte and has high plasticization efficiency.

Only 1 type may be used for a plasticizer (C), and 2 or more types may be used together.
If the compatibility between the water-soluble polysaccharide (A) and the plasticizer (C) is low, it is difficult to obtain an effect of improving stretchability and moldability, and the water-soluble polysaccharide (A) and the plasticizer (C) are separated. As a result, the plasticizer oozes out (leaching) on the surface, sweating (sweating), loss of transparency (devitrification), and white turbidity may occur.
As the plasticizer (C), a glycol plasticizer and a sugar alcohol plasticizer are more preferable because they have high compatibility with the water-soluble polysaccharide (A), good transparency, and no sweating. .

The base material protective layer 18 preferably contains a surfactant (D). The surfactant (D) is a compound that shares a hydrophilic part and a hydrophobic part in the molecule.
Since the base material protective layer 18 contains the surfactant (D), the hydrophobic group of the surfactant (D) is directed to the surface of the base material protective layer 18 and the base material protective layer 18 has water repellency. Good electrolyte resistance is obtained.

As the surfactant (D), a surfactant having a hydroxyl group and a hydrophobic group is preferable.
Examples of the material that imparts the hydrophobic group of the surfactant (D) include hydrocarbon-based materials, fluorine-based materials, and organic silicon-based materials.
Examples of the hydrocarbon-based material include triglyceride, fatty acid, fatty alcohol, fatty acid derivative, resin acid, naphthenic acid, α-olefin, polyolefin, alkylbenzene, alkylphenol, alcohol, polyoxyalkylene glycol, and the like.
Examples of the fluorocarbon material include fully fluorinated fatty acids, partially fluorinated fatty acids, fully fluorinated fatty alcohols, and partially fluorinated fatty alcohols.
Examples of the organosilicon material include polysiloxanes.

The material that gives the hydroxyl group of the surfactant (D) is mainly classified into four types: an anionic material, a cationic material, an amphoteric material, and a nonionic material.
Examples of the anionic material include carboxylate, sulfonate, sulfate ester salt, phosphate ester salt, and phosphonate.
Examples of the cationic material include amine salts, quaternary ammonium salts, pyridinium salts, sulfonium salts, phosphonium salts, and polyethylene polyamines.
Examples of amphoteric materials include amino acids, betaines, amino sulfates, esters, sulfobetaines and the like.
Examples of the nonionic material include polyhydric alcohol, amino alcohol, polyethylene glycol, amine oxide, sulfoxide, and amine imide.

Specific examples of the surfactant (D) include soap, sulfated oil, alkylnaphthalene sulfonate, α-sulfo fatty acid salt, N, N-dimethyloleoylamide ethylamine acetate, triethanolamine monooleate. , Alkyl sulfate, oleoyl isethionate, N-methyl-N-oleoyl taurine, polyoxyethylene oleyl ether, polyoxyethylene oleate, fatty acid proteolysate condensate, heptadecylbenzimidazole sulfonate, sorbitan Fatty acid ester, di-2-ethylhexyl sulfosuccinate, dodecylbenzene sulfonate, alkyl sulfonate, polyoxyethylene alkyl phenyl ether, polyoxyethylene sorbitan fatty acid ester, alkyl sulfoacetate, dimethyl ester Lulaurylamine oxide, alkyl phosphate derivative, n-dodecyl bromide-poly α-vinyl pyridine polymer, polyoxypropylene-polyoxyethylene block polymer, sucrose fatty acid ester (sucrose stearate monoester, sucrose laurate mono Ester, etc.), polyoxyethylene alkyl phosphate ester, polyglycerin fatty acid ester (decaglycerin laurate ester, etc.) and the like.
Only 1 type may be used for surfactant (D) and it may use 2 or more types together. Further, the surfactant (D) may be used in combination with the polymer compound (B) or the plasticizer (C).

The base material protective layer 18 preferably contains a lubricant or is applied to the surface. Thereby, the moldability and winding yield of the exterior material 1 are improved. When the base material protective layer 18 contains a lubricant, it is preferable that the base material protective layer 18 contains a lubricant on the side opposite to the base material layer 11. In particular, when a lubricant is applied to the surface of the base material protective layer 18, the surface slipperiness is good and the moldability is improved.
Examples of the lubricant include fatty acid amides (for example, oleic acid amide, erucic acid amide, stearic acid amide, behenic acid amide, ethylene bisoleic acid amide, ethylene biserucic acid amide) and the like.
One type of lubricant may be used alone, or two or more types may be used in combination.

  The base material protective layer 18 may contain an elastomer component. With the elastomer component, an exterior material having high stretchability and moldability can be obtained. Examples of the elastomer component include olefin elastomers, styrene elastomers, and polyester elastomers. When the base material protective layer 18 contains an elastomer component, the elastomer component is preferably contained uniformly in the base material protective layer 18.

Examples of olefin elastomers include ethylene / propylene copolymers, ethylene / 1-butene copolymers, ethylene / α-olefin copolymers, propylene / 1-butene copolymers, propylene / α-olefin copolymers. 1-butene / α-olefin copolymer, propylene / 1-butene / ethylene copolymer, propylene / α-olefin / ethylene copolymer, propylene / α-olefin / 1-butene copolymer, 1-butene -An alpha-olefin-ethylene copolymer etc. are mentioned.
Examples of the styrene elastomer include styrene / ethylene / butylene / styrene copolymers and styrene / ethylene / propylene / styrene copolymers.
Examples of the hard segment of the polyester elastomer include crystalline polyesters such as polybutylene terephthalate, polybutylene naphthalate and polyethylene terephthalate, and polybutylene terephthalate is particularly preferable. Examples of the soft segment of the polyester elastomer include polyoxyalkylene glycols such as polytetramethylene glycol or polyesters such as polycaprolactone and polybutylene adipate, and polytetramethylene glycol is particularly preferable.
An elastomer component may be used individually by 1 type, and may use 2 or more types together.

The base material protective layer 18 preferably contains one or more filler components selected from the group consisting of organic fillers and inorganic fillers. Thereby, the scratch resistance of the base material protective layer 18 is improved.
As the organic filler, for example, plastic powder or fine particles can be used.
Examples of the plastic include acrylic, polyethylene, polystyrene, polycarbonate, vinyl chloride, vinylidene chloride, and melamine.
Examples of the inorganic filler include fine particles such as carbon, silica, glass beads, glass powder, aluminum silicate, clay, zinc oxide, calcium carbonate, boron nitride, and mica.

The substrate protective layer 18 preferably contains a pigment in terms of design. When a pigment is used, the pigment may be contained in any layer outside the metal foil layer 13. However, since the pigment dispersibility is excellent and the color tends to be uniform, the pigment is added to the base material protective layer 18. It is preferable to contain.
The pigment is not particularly limited as long as the adhesion between the base material protective layer 18 and the base material layer 11 is not impaired, and may be an organic pigment or an inorganic pigment.
Examples of organic pigments include azo, phthalocyanine, quinacridone, anthraquinone, dioxazine, indigothioindigo, perinone-perylene, and isoindolenin.
Examples of inorganic pigments include carbon black, titanium oxide, cadmium, lead, and oxide oxide. Mica (mica) fine powder, fish scale foil, and the like may also be used.

From the viewpoint of water resistance, the base material protective layer 18 preferably has a crosslinked structure formed by a crosslinking agent.
Examples of the crosslinking agent include oxazoline, divinyl sulfone, carbodiimide, dihydrazine, dihydrazide, epichlorohydrin and the like. The said crosslinking agent may be used individually by 1 type, and may use 2 or more types together.

The base material protective layer 18 may contain salts such as zirconyl salts, chromium salts, aluminum salts, urea resins, melamine resins, and phenol resins for the purpose of improving water resistance.
The base material protective layer 18 may contain additives such as a flame retardant, an anti-blocking agent, an antioxidant, a light stabilizer, a tackifier, and an antistatic agent in addition to the above-described ones.

  The content of the water-soluble polysaccharide (A) in the base material protective layer 18 (100% by mass) is preferably 20% by mass or more, and preferably 30% by mass or more from the viewpoint that excellent electrolytic solution resistance and scratch resistance can be obtained. Is more preferable. If the content of the water-soluble polysaccharide (A) is at least the lower limit, resistance to hydrofluoric acid can be sufficiently obtained. The content of the water-soluble polysaccharide (A) is such that an effect of at least one selected from the group consisting of a water-soluble polymer (B), a plasticizer (C) and a surfactant (D) can be easily obtained. 90 mass% or less is preferable, and 80 mass% or less is more preferable.

  The total content of the water-soluble polymer (B), the plasticizer (C) and the surfactant (D) in the substrate protective layer 18 (100% by mass) is preferably 10% by mass or more, more preferably 20% by mass or more. Is more preferable. When the total content is at least the lower limit value, good stretchability and moldability are easily obtained, and excellent electrolyte resistance is easily maintained after stretching. The total content is preferably 80% by mass or less, and more preferably 70% by mass or less. If the total content is not more than the upper limit, the effect of the water-soluble polysaccharide (A) can be easily obtained.

  When the water-soluble polymer (B) is contained in the base material protective layer 18, the content of the water-soluble polymer (B) in the base material protective layer 18 (100% by weight) is preferably 10% by weight or more. The mass% or more is more preferable. If content of the said water-soluble polymer (B) is more than a lower limit, it will be easy to obtain favorable drawability and moldability, and it will be easy to maintain the outstanding electrolyte solution resistance after extending | stretching. The content of the water-soluble polymer (B) is preferably 80% by mass or less, and more preferably 70% by mass or less. If content of the said water-soluble polymer (B) is below an upper limit, the effect by water-soluble polysaccharide (A) will be easy to be acquired.

  When the plasticizer (C) is contained in the base material protective layer 18, the content of the plasticizer (C) in the base material protective layer 18 (100% by weight) is preferably 10% by weight or more, and more preferably 20% by weight or more. More preferred. If content of the said plasticizer (C) is more than a lower limit, it will be easy to obtain favorable extending | stretching property and moldability, and it will be easy to maintain the electrolyte solution outstanding after extending | stretching. 80 mass% or less is preferable and, as for content of the said plasticizer (C), 70 mass% or less is more preferable. If content of the said plasticizer (C) is below an upper limit, the effect by water-soluble polysaccharide (A) will be easy to be acquired.

  When the surfactant (D) is contained in the substrate protective layer 18, the content of the surfactant (D) in the substrate protective layer 18 (100 mass%) is preferably 0.01 mass% or more, 0 More preferably 1% by mass or more. When the content of the surfactant (D) is at least the lower limit value, good stretchability and moldability are easily obtained, and excellent electrolyte resistance is easily maintained after stretching. 80 mass% or less is preferable and, as for content of the said surfactant (D), 70 mass% or less is more preferable. If content of the said surfactant (D) is below an upper limit, the effect by water-soluble polysaccharide (A) will be easy to be acquired.

  When the base material protective layer 18 contains a lubricant, the content of the lubricant in the base material protective layer 18 (100% by mass) is preferably 0.1 to 10% by mass, and 1 to 5% by mass. More preferred. If content of the said lubricant is more than a lower limit, moldability will become more favorable. If content of the said lubricant is below an upper limit, it will suppress that a lubricant bleeds to the base material layer 11 side of the base material protective layer 18, and the adhesiveness of the base material layer 11 and the base material protective layer 18 falls. Cheap.

  When making the base material protective layer 18 contain an elastomer component, 5-90 mass% is preferable and, as for content of the elastomer component in the base material protective layer 18 (100 mass%), 10-70 mass% is more preferable. If content of the said elastomer component is more than a lower limit, stretchability and moldability will improve and it will be easy to obtain favorable abrasion resistance and electrolyte solution tolerance. If content of the said elastomer component is below an upper limit, heat resistance will become more favorable.

  When making the base-material protective layer 18 contain a filler component, 0.1-5 mass% is preferable and, as for content of the filler component in the base-material protective layer 18 (100 mass%), 1-30 mass% is more preferable. . If content of the said filler component is below an upper limit, favorable moldability will be easy to be obtained and it will be easy to suppress the fall of the electrolyte solution tolerance after shaping | molding. If the content of the filler component is at least the lower limit value, good scratch resistance can be easily obtained.

  When making the base material protective layer 18 contain a pigment, 0.1-30 mass% is preferable and, as for content of the pigment in the base material protective layer 18 (100 mass%), 5-20 mass% is more preferable. If content of the said pigment is the said range, designability will become favorable.

  0.1-5.0 micrometers is preferable and, as for the thickness of the base-material protective layer 18, 0.3-3 micrometers is more preferable. If the thickness of the base material protective layer 18 is equal to or more than the lower limit value, the electrolytic solution resistance and the scratch resistance become better. If the thickness of the base material protective layer 18 is less than or equal to the upper limit value, the adhesion and moldability will be better.

(3rd adhesive layer)
The third adhesive layer 17 is a layer that bonds the base material layer 11 and the base material protective layer 18 together. By adhering the base material layer 11 and the base material protective layer 18 via the third adhesive layer 17, the adhesion, moldability, and tensile strength between the base material layer 11 and the base material protective layer 18 are improved.
Examples of the third adhesive layer 17 include a layer formed by applying a coating liquid containing an adhesive resin (E).
The adhesive resin (E) is at least one selected from the group consisting of phenol resin, urea resin, melamine resin, polyvinyl resin, polyolefin resin, urethane resin, epoxy resin, acrylic resin, polyester resin, polyamide resin and polystyrene resin. Species are mentioned.
The adhesive resin (E) is preferably an acrylic resin or a polyvinyl resin from the viewpoint of good adhesion.

  Further, the third adhesive layer 17 may be formed of a urethane-based adhesive described later in the section of the first adhesive layer 12, or may be formed of an adhesive component having a thermal laminate configuration described later in the section of the second adhesive layer 15. Also good.

The third adhesive layer 17 may contain additives such as fillers, pigments, dyes, flame retardants, lubricants, antiblocking agents, antioxidants, light stabilizers, tackifiers, and antistatic agents.
The thickness of the third adhesive layer 17 is preferably 0.1 to 5.0 μm from the viewpoint of adhesive strength.
The total thickness of the third adhesive layer 17 and the base material protective layer 18 is preferably 1.0 to 6.0 μm from the viewpoint of adhesive strength and moldability.

(Base material layer)
The base material layer 11 is a layer made of a nylon film.
The nylon film may be a stretched film or an unstretched film. Examples of the nylon forming the nylon film include nylon 6, nylon 11, nylon 12, nylon 66, nylon 610, nylon 612, and the like.
The second surface 11b of the base material layer 11 is preferably subjected to surface treatment such as corona treatment or plasma treatment. That is, the nylon film forming the base material layer 11 is preferably subjected to a surface treatment such as corona treatment or plasma treatment on the surface on which the base material protective layer 18 is provided. Thereby, the adhesiveness of the base material layer 11 and the base material protective layer 18 becomes better.

6-40 micrometers is preferable and, as for the thickness of the base material layer 11, 10-30 micrometers is more preferable. If the thickness of the base material layer 11 is equal to or more than the lower limit value, the pinhole resistance and the insulation are improved. If the thickness of the base material layer 11 is not more than the upper limit value, the moldability becomes better.
A coupling agent may be coated on the surface of the base material layer 11 on the first adhesive layer 12 side in order to help improve the adhesive strength.

(First adhesive layer)
The first adhesive layer 12 is a layer that bonds the base material layer 11 and the metal foil layer 13 together.
As an adhesive component constituting the first adhesive layer 12, a two-component curable type in which a bifunctional or higher aromatic or aliphatic isocyanate compound is allowed to act as a curing agent on a main component such as polyester polyol, polyether polyol, and acrylic polyol. The urethane adhesive is preferable.
For example, the urethane-based adhesive is aged at 40 ° C. for 4 days or more after coating, whereby the reaction of the hydroxyl group of the main agent and the isocyanate group of the curing agent proceeds to enable strong adhesion.
The thickness of the first adhesive layer 12 is preferably 1 to 10 μm, more preferably 3 to 7 μm, from the viewpoint of adhesive strength, followability, and workability.

(Metal foil layer)
As the metal foil layer 13, various metal foils such as aluminum and stainless steel can be used, and aluminum foil is preferable from the viewpoint of workability such as moisture resistance and spreadability and cost. A general soft aluminum foil can be used as the aluminum foil. Among these, an aluminum foil containing iron is preferable from the viewpoint of excellent pinhole resistance and extensibility during molding.
0.1-9.0 mass% is preferable and, as for content of iron in the aluminum foil (100 mass%) containing iron, 0.5-2.0 mass% is more preferable. When the iron content is 0.1% by mass or more, the exterior material 1 is excellent in pinhole resistance and spreadability. If the iron content is 9.0% by mass or less, the exterior material 1 is excellent in flexibility.
The thickness of the metal foil layer 13 is preferably 9 to 200 μm, more preferably 15 to 100 μm, from the viewpoint of barrier properties, pinhole resistance, and workability.

(Corrosion prevention treatment layer)
The corrosion prevention treatment layer 14 serves to suppress the corrosion of the metal foil layer 13 due to the electrolytic solution or hydrofluoric acid generated by the reaction between the electrolytic solution and moisture. A lithium salt such as LiPF ₆ or LiBF ₄ used for an electrolyte of a lithium ion battery generates hydrofluoric acid by a hydrolysis reaction with moisture. By providing the corrosion prevention treatment layer 14, the inner side of the metal foil layer 13 is also prevented from being corroded by hydrofluoric acid, and delamination inside the metal foil layer can be suppressed. The corrosion prevention treatment layer 14 also plays a role of increasing the adhesion between the metal foil layer 13 and the second adhesive layer 15.
As the corrosion prevention treatment layer 14, a coating film formed by a coating type or immersion type acid resistant corrosion prevention treatment agent is preferable. The said coating film is excellent in the corrosion prevention effect with respect to the acid of the metal foil layer 13. FIG. Moreover, since the adhesive force of the metal foil layer 13 and the 2nd contact bonding layer 15 is strengthened by an anchor effect, the outstanding tolerance with respect to contents, such as electrolyte solution, is acquired.

As the coating film, for example, a coating film, chromate, phosphate, fluoride, and various thermosettings formed by a ceriazol treatment with a corrosion preventing treatment agent composed of cerium oxide, phosphate and various thermosetting resins. For example, a coating film formed by chromate treatment with a corrosion-inhibiting treatment agent made of a conductive resin.
The corrosion prevention treatment layer 14 is not limited to the coating film as long as the corrosion resistance of the metal foil layer 13 is sufficiently obtained. For example, a coating film formed by phosphate treatment, boehmite treatment, or the like may be used.

The corrosion prevention treatment layer 14 may be a single layer or a plurality of layers. In addition, an additive such as a silane coupling agent may be added to the corrosion prevention treatment layer 14.
The thickness of the corrosion prevention treatment layer 14 is preferably 10 nm to 5 μm, and more preferably 20 to 500 nm from the viewpoint of the corrosion prevention function and the function as an anchor.

(Second adhesive layer)
The second adhesive layer 15 is a layer that bonds the metal foil layer 13 on which the corrosion prevention treatment layer 14 is formed and the sealant layer 16. The packaging material 1 is roughly divided into a thermal laminate configuration and a dry laminate configuration depending on the adhesive component forming the second adhesive layer 15.
As an adhesive component for forming the second adhesive layer 15 in the thermal laminate configuration, an acid-modified polyolefin resin obtained by graft-modifying a polyolefin resin with an acid such as maleic anhydride is preferable. Since the acid-modified polyolefin-based resin has a polar group introduced into a part of the non-polar polyolefin-based resin, the sealant layer 16 is formed of a non-polar polyolefin-based resin film or the like, and the corrosion prevention treatment layer 14 is formed. When the coating film has polarity, it can be firmly adhered to both of them. In addition, by using acid-modified polyolefin resin, resistance to contents such as electrolyte solution is improved, and even if hydrofluoric acid is generated inside the battery, a decrease in adhesion due to deterioration of the second adhesive layer 15 is prevented. Cheap.
The acid-modified polyolefin resin used for the second adhesive layer 15 may be one type or two or more types.

Examples of the polyolefin resin used for the acid-modified polyolefin resin include, for example, low density, medium density or high density polyethylene; ethylene / α-olefin copolymer; homo, block or random polypropylene; propylene / α-olefin copolymer. Etc. In addition, a copolymer obtained by copolymerizing polar molecules such as acrylic acid and methacrylic acid with the above-described one, a polymer such as a crosslinked polyolefin, and the like can also be used.
Examples of the acid that modifies the polyolefin-based resin include carboxylic acid, epoxy compound, acid anhydride, and the like, and maleic anhydride is particularly preferable.

As an adhesive component constituting the second adhesive layer 15 of the heat laminate structure, the polyolefin resin is made of maleic anhydride from the viewpoint that it is easy to maintain the adhesion between the sealant layer 16 and the metal foil layer 13 even if the electrolyte solution penetrates. A graft-modified maleic anhydride-modified polyolefin resin is preferable, and maleic anhydride-modified polypropylene is particularly preferable.
The modification rate of maleic anhydride-modified polypropylene with maleic anhydride (the mass of the portion derived from maleic anhydride relative to the total mass of maleic anhydride-modified polypropylene) is preferably 0.1 to 20% by mass, and 0.3 to 5% by mass. % Is more preferable.

  It is preferable that the second adhesive layer 15 having a heat laminate structure contains the elastomer component described in the base material protective layer 18. Thereby, it is easy to suppress that the second adhesive layer 15 is cracked and whitened at the time of cold forming, and it can be expected to improve adhesion by improving wettability, and improve film forming property by reducing anisotropy. . The elastomer component is preferably dispersed and compatible with each other in the order of nanometers in the acid-modified polyolefin resin.

The second adhesive layer 15 having a heat laminate structure can be formed by extruding the adhesive component with an extrusion device.
The melt flow rate (MFR) of the adhesive component of the second adhesive layer 15 having a heat laminate structure is preferably 4 to 30 g / 10 min under the conditions of 230 ° C. and 2.16 kgf.
As for the thickness of the 2nd contact bonding layer 15 of a heat lamination structure, 2-50 micrometers is preferable.

Examples of the adhesive component of the second adhesive layer 15 having a dry laminate structure include a two-component curable polyurethane adhesive similar to that described for the first adhesive layer 12.
Since the second adhesive layer 15 having a dry laminate structure has a hydrolyzable bonding portion such as an ester group or a urethane group, the second adhesive layer having a heat laminate structure is required for applications that require higher reliability. 15 is preferred.

(Sealant layer)
The sealant layer 16 is a layer that imparts sealing properties by heat sealing in the exterior material 1.
Examples of the sealant layer 16 include a polyolefin resin or a resin film made of an acid-modified polyolefin resin obtained by graft-modifying an acid such as maleic anhydride to a polyolefin resin.
Examples of the polyolefin resin include low density, medium density, or high density polyethylene; ethylene / α-olefin copolymer; homo, block, or random polypropylene; propylene / α-olefin copolymer. These polyolefin resin may be used individually by 1 type, and may use 2 or more types together.
Examples of the acid-modified polyolefin-based resin include the same as those mentioned in the second adhesive layer 15.

  The sealant layer 16 may be a single layer film or a multilayer film, and may be selected according to a required function. As the sealant layer 16, for example, a multilayer film in which a resin such as an ethylene / cyclic olefin copolymer or polymethylpentene is interposed can be used in terms of imparting moisture resistance.

When a film formed by extrusion molding is used as the sealant layer 16, molecules tend to be oriented in the extrusion direction of the film. You may mix | blend the demonstrated elastomer component. This makes it difficult for the sealant layer 16 to be whitened when the exterior material 1 is cold-molded to form a recess.
The sealant layer 16 may be blended with various additives such as a flame retardant, a lubricant, an antiblocking agent, an antioxidant, a light stabilizer, and a tackifier.
10-100 micrometers is preferable and, as for the thickness of the sealant layer 16, 20-60 micrometers is more preferable.

  The exterior material 1 may be one in which the sealant layer 16 is laminated by dry lamination, but from the viewpoint of improving adhesion, the second adhesive layer 15 is made of an acid-modified polyolefin resin, and the sealant layer 16 is laminated by sandwich lamination. It is preferable that

(Production method)
Hereinafter, the manufacturing method of the exterior material 1 is demonstrated. However, the manufacturing method of the exterior material 1 is not limited to the following method. As a manufacturing method of the exterior material 1, the method which has the following process (X1)-(X4) is mentioned, for example.
(X1) A step of forming a corrosion prevention treatment layer 14 on the metal foil layer 13.
(X2) A step of laminating the base material layer 11 via the first adhesive layer 12 on the side opposite to the side on which the corrosion prevention treatment layer 14 is formed in the metal foil layer 13.
(X3) The process of laminating | stacking the base material protective layer 18 through the 3rd contact bonding layer 17 on the opposite side to the 1st contact bonding layer 12 of the base material layer 11. FIG.
(X4) A step of laminating the sealant layer 16 on the corrosion prevention treatment layer 14 side of the metal foil layer 13 via the second adhesive layer 15.

Step (X1):
For example, a corrosion prevention treatment agent is applied to one surface of the metal foil layer 13 and dried to form the corrosion prevention treatment layer 14. Examples of the anti-corrosion treatment agent include the above-described anti-corrosion treatment agent for ceriazole treatment, anti-corrosion treatment agent for chromate treatment, and the like.
The coating method of the corrosion inhibitor is not particularly limited, and various methods such as gravure coating, reverse coating, roll coating, and bar coating can be employed.

Step (X2):
The base material layer 11 is bonded to the side of the metal foil layer 13 opposite to the side on which the corrosion prevention treatment layer 14 is formed, using an adhesive that forms the first adhesive layer 12 by a technique such as dry lamination.
In the step (X2), an aging treatment may be performed in the range of room temperature to 100 ° C. in order to promote adhesion.

Step (X3):
For example, on the opposite side of the base material layer 11 from the first adhesive layer 12, a coating liquid containing an adhesive resin (E) and components such as additives to be used as necessary is applied and dried to form a third adhesive layer 17 is formed. Furthermore, it contains at least one selected from the group consisting of a water-soluble polysaccharide (A) and a water-soluble polymer (B), a plasticizer (C) and a surfactant (D), and if necessary, a lubricant The base material protective layer 18 is formed by coating and drying a coating liquid containing an elastomer component and the like. At this time, the base material protective layer 18 composed of a plurality of layers, for example, prepares a plurality of coating liquids containing water-soluble polysaccharides (A) having different degrees of polymerization, and the coating liquids are water-soluble with a low degree of polymerization. It can form by coating and drying in order from the coating liquid containing polysaccharide (A).
The base material protective layer 18 may be formed by forming a film using a material for forming the base material protective layer 18 and laminating the film.

  0.5-20 mass% is preferable and, as for the solid content concentration of the coating liquid which forms the 3rd contact bonding layer 17, 1-10 mass% is more preferable. If the solid content concentration is at least the lower limit, drying after coating becomes easy. When the solid content concentration is not more than the upper limit value, the coatability becomes better.

The coating liquid for forming the base material protective layer 18 is selected from the group consisting of, for example, a water-soluble polysaccharide (A), a water-soluble polymer (B), a plasticizer (C), and a surfactant (D). An aqueous dispersion containing at least one kind can be used. The aqueous dispersion may contain alcohols.
0.5-20 mass% is preferable and, as for the solid content concentration of the coating liquid which forms the base-material protective layer 18, 1-10 mass% is more preferable. If the solid content concentration is at least the lower limit, drying after coating becomes easy. When the solid content concentration is not more than the upper limit value, the coatability becomes better.

  Further, after forming the third adhesive layer 17 using the same adhesive as the adhesive forming the first adhesive layer 12, the base material protective layer 18 may be formed in the same manner as described above. Alternatively, the base material protective layer 18 may be formed in the same manner as described above after the third adhesive layer 17 is formed by an extrusion laminating method using an adhesive component that forms the second adhesive layer 15.

Step (X4):
In the case of a dry laminate configuration, for example, the same adhesive as that used to form the first adhesive layer 12 is used, and dry lamination, non-solvent lamination, wet lamination is provided on the side opposite to the metal foil layer 13 in the corrosion prevention treatment layer 14. The sealant layer 16 is bonded through the second adhesive layer 15 by a method such as the above.
In the case of the thermal laminate configuration, in the dry process, for example, the second adhesive layer 15 is formed by extrusion lamination on the opposite side of the corrosion prevention treatment layer 14 from the metal foil layer 13 using an adhesive component for thermal lamination, and sandwiched. The sealant layer 16 is laminated by lamination.
In the wet process, an adhesive resin liquid in which an adhesive component for heat laminating is dispersed in a solvent is applied to the side opposite to the metal foil layer 13 in the corrosion prevention treatment layer 14, and the solvent is removed at a temperature equal to or higher than the melting point of the adhesive component. After volatilizing and melting and softening the adhesive component, the sealant layer 16 is laminated on the second adhesive layer 15 by heat treatment such as thermal lamination.

The packaging material 1 is obtained by the steps (X1) to (X4) described above.
In addition, the manufacturing method of the exterior material 1 is not limited to the method of implementing the said process (X1)-(X4) sequentially. For example, the step (X1) may be performed after performing the step (X2). Further, the step (X3) may be performed after performing the step (X4).

  The exterior material 1 is provided with the base material protective layer 18 containing the water-soluble polysaccharide (A) on the outside of the base material layer 11, so that it can be used for in-vehicle use in addition to excellent electrolytic solution resistance. It has excellent scratch resistance. Moreover, the exterior material 1 is because the base-material protective layer 18 contains at least 1 sort (s) chosen from the group which consists of a water-soluble polymer (B), a plasticizer (C), and surfactant (D). It has excellent stretchability and moldability, and can maintain good electrolytic solution resistance after stretching. Moreover, since it has the 3rd contact bonding layer 17 containing adhesive resin (E), compared with the case where there is no 3rd contact bonding layer 17, the adhesiveness of the base material layer 11 and the base material protective layer 18 is especially excellent. ing.

<Other embodiments>
In addition, the exterior material of this invention is not limited to the said exterior material. For example, the exterior material of the present invention may not have the third adhesive layer as long as the effect of the present invention is not impaired. Specifically, the exterior material 2 for lithium ion batteries illustrated in FIG. 2 (hereinafter referred to as “exterior material 2”) may be used.
The packaging material 2 is provided on the side opposite to the base material layer 11, the first adhesive layer 12 provided on the first surface 11 a side of the base material layer 11, and the first adhesive layer 12. The metal foil layer 13, the corrosion prevention treatment layer 14 provided on the opposite side of the metal foil layer 13 from the first adhesive layer 12, and the second adhesion provided on the opposite side of the corrosion prevention treatment layer 14 to the metal foil layer 13. A layer 15, a sealant layer 16 provided on the second adhesive layer 15 on the opposite side of the corrosion prevention treatment layer 14, and a base material protective layer 18 provided on the second surface 11b side of the base material layer 11. Have. That is, the exterior material 2 has a base material protective layer 18, a base material layer 11, a first adhesive layer 12, a metal foil layer 13, a corrosion prevention treatment layer 14, a second adhesive layer 15, and a sealant layer 16 laminated in this order. It is a laminate.
When the third adhesive layer is not provided as in the case of the exterior material 2, it is preferable that the base material protective layer contains a water-soluble polymer (B) from the viewpoint that excellent adhesion is easily obtained. More preferably, polyvinylpyrrolidone, sodium polyacrylate and the like are included.

Moreover, if the exterior material of this invention is in the range which does not impair the effect of this invention, it is between a base material protective layer and a 3rd contact bonding layer, between a 3rd contact bonding layer and a base material layer, a base material layer, and the 1st. Between one adhesive layer, between the first adhesive layer and the metal foil layer, between the metal foil layer and the corrosion prevention treatment layer, between the corrosion prevention treatment layer and the second adhesion layer, and between the second adhesion layer and the sealant layer. Any one of them may have another layer. For example, a corrosion prevention treatment layer may be formed between the metal foil layer and the first adhesive layer. If the corrosion prevention treatment layer is also formed on the first adhesive layer side of the metal foil layer, it becomes easier to suppress the first adhesive layer side of the metal foil layer from being corroded by the electrolytic solution.
Moreover, if the exterior material of this invention is in the range which does not impair the effect of this invention, it may have another layer on the outer side of a base-material protective layer. As the exterior material of the present invention, it is preferable that the base material protective layer is the outermost layer from the viewpoint that an effect of being excellent in electrolytic solution resistance and scratch resistance is easily obtained.
Moreover, it is preferable that a sealant layer is also an outermost layer from the point that the sealing performance by heat seal is acquired favorably.

Examples of the lithium ion battery formed using the exterior material of the present invention include lithium ion batteries used for portable terminal devices such as personal computers and mobile phones, video cameras, satellites, submarines, electric cars, and electric bicycles. Of these, an in-vehicle lithium ion battery such as an electric vehicle is preferable.
Lithium ion batteries include, for example, battery contents having a tab made of a positive electrode, a separator, a negative electrode, an electrolyte, and leads and a tab sealant in a container body in which the outer packaging material of the present invention is formed into a bag shape or the like. It is manufactured by housing and sealing so that the part is located outside. The lithium ion battery can adopt a known form except for having the exterior material of the present invention.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited by the following description.
(Base material protective layer 18)
Water-soluble polysaccharide A-1: TEMPO oxidized cellulose obtained by the method shown below.
(1) Reagents / Materials Cellulose: Bleached Kraft Pulp (Fletcher Challenge Canada “Machenzie”),
TEMPO: Commercial product (Tokyo Chemical Industry Co., Ltd., 98%),
Sodium hypochlorite: commercial product (Wako Pure Chemical Industries, Ltd., C1: 5%),
Sodium bromide: Commercial product (Wako Pure Chemical Industries, Ltd.).
(2) TEMPO oxidation reaction of cellulose A 2 L glass beaker was charged with 10 g of dry kraft pulp and 500 ml of ion-exchanged water and allowed to stand overnight to swell the pulp. The temperature was adjusted to 40.0 ° C. with a water bath with temperature control, and 0.1 g of TEMPO and 1 g of sodium bromide were added and stirred to obtain a pulp suspension. Furthermore, 5 mmol / g sodium hypochlorite per cellulose mass was added with stirring. At this time, about 1N sodium hydroxide aqueous solution was added to maintain the pH of the pulp suspension at about 10.5. Thereafter, the reaction was performed for 3 hours, and the pulp was sufficiently washed with ion-exchanged water to obtain TEMPO oxidized cellulose (water-soluble polysaccharide A-1).
When the molecular weight of the obtained TEMPO-oxidized cellulose freeze-dried was measured by a viscosity method using a copper ethylenediamine solution, the degree of polymerization was 480. Moreover, when 1 part by mass of the obtained TEMPO-oxidized cellulose was added to 100 parts by mass of distilled water and stirred, the TEMPO-oxidized cellulose was completely dissolved in a molecular state.
Water-soluble polymer B-1: Polyvinyl alcohol (degree of polymerization: 2400, molecular weight of about 100,000, trade name “PVA124”, manufactured by Kuraray Co., Ltd.). When 1 part by mass of the polyvinyl alcohol (PVA124) was added to 100 parts by mass of distilled water and stirred, the polyvinyl alcohol (PVA124) was completely dissolved in a molecular state.
Water-soluble polymer B-2: Polyvinyl alcohol (degree of polymerization: 500, molecular weight of about 22,000, trade name “PVA205”, manufactured by Kuraray Co., Ltd.). When 1 part by mass of the polyvinyl alcohol (PVA205) was added to 100 parts by mass of distilled water and stirred, the polyvinyl alcohol (PVA205) was completely dissolved in a molecular state.
Plasticizer C-1: Sorbitol (trade name “Sorbit T-70”, manufactured by Mitsubishi Corporation Food Tech Co., Ltd.).
Plasticizer C-2: Polyglycerin (trade name “polyglycerin # 500”, manufactured by Sakamoto Pharmaceutical Co., Ltd.).
Surfactant D-1: Sucrose fatty acid ester (trade name “sucrose lauric acid monoester LWA-1570”, manufactured by Mitsubishi Chemical Foods Corporation).
Surfactant D-2: Polyglycerin fatty acid ester (trade name “decaglycerin laurate L-7D”, manufactured by Sakamoto Pharmaceutical Co., Ltd.).
(Third adhesive layer 17)
Adhesive Component E-1: Modified Polyvinyl Alcohol (trade name “D Polymer DF17”, manufactured by NIPPON VICHI POVAL CO., LTD.) And adipic acid dihydrazide (trade name “Adipic Acid Dihydrazide”, manufactured by Otsuka Chemical Co., Ltd.) 5 mass% was mixed with respect to solid content of alcohol.
Adhesive component E-2: Modified polyolefin resin (trade name “Arrow Base SD1200”, manufactured by Unitika Ltd.).
(Base material layer 11)
Film F-1: Nylon 6 film having a thickness of 25 μm.
(First adhesive layer 12)
Adhesive component G-1: Urethane-based adhesive (trade name “A525 / A50”, manufactured by Mitsui Chemicals Polyurethane Co., Ltd.).
(Metal foil layer 13)
Metal foil H-1: Soft aluminum foil 8079 material (manufactured by Toyo Aluminum Co., Ltd., thickness 40 μm).
(Corrosion prevention treatment layer 14)
Treatment I-1: “Sodium polyphosphate-stabilized cerium oxide sol” adjusted to a solid content concentration of 10% by mass using distilled water as a solvent. The phosphate was 10 parts by mass with respect to 100 parts by mass of cerium oxide.
(Second adhesive layer 15)
Adhesive component J-1: Polypropylene resin graft-modified with maleic anhydride (trade name “Admer”, manufactured by Mitsui Chemicals, Inc.).
(Sealant layer 16)
Film K-1: A film obtained by corona-treating the surface to be the inner surface of an unstretched polypropylene film (thickness: 40 μm).

[Example 1]
The treatment agent I-1 was applied to one surface of the metal foil H-1 and dried to form a corrosion prevention treatment layer 14 (thickness: 200 μm) on one surface of the metal foil layer 13. Next, the film F-1 is bonded to the opposite side of the corrosion prevention treatment layer 14 in the metal foil layer 13 by the dry laminating method using the adhesive component G-1, and the first adhesive layer 12 (thickness 4 μm) is interposed therebetween. The base material layer 11 was laminated. Thereafter, aging was performed at 60 ° C. for 6 days.
Next, on the side opposite to the first adhesive layer 12 of the base material layer 11, a coating liquid (solid content concentration 5 mass%) in which the adhesive component E-1 and distilled water are mixed is applied by a gravure coating method, It was made to dry and the 3rd contact bonding layer 17 (thickness 0.5 micrometer) was formed. Thereafter, the coating liquid (solid content concentration 2 mass%) mixed with distilled water at a ratio of water-soluble polysaccharide A-1, water-soluble polymer B-1 and solid content concentration of 7: 3, and the third adhesive layer 17 On the side opposite to the base material layer 11, coating and drying were carried out by a gravure coating method to form a base material protective layer 18 (thickness 150 μm).
Next, the adhesive component J-1 is extruded by an extrusion device on the corrosion prevention treatment layer 14 side of the obtained laminate to form a second adhesive layer 15 (thickness 4 μm), and the film K-1 is bonded together. The sealant layer 16 was formed by sandwich lamination. Then, the obtained laminate, 160 ° C., to obtain a sheathing material by heat pressing at 4kg ^/ cm 2, 2m ^/ min conditions.

[Example 2]
An exterior material was obtained in the same manner as in Example 1 except that the water-soluble polymer B-2 was used instead of the water-soluble polymer B-1.

[Example 3]
An exterior material was obtained in the same manner as in Example 1 except that the plasticizer C-1 was used instead of the water-soluble polymer B-1.

[Example 4]
An exterior material was obtained in the same manner as in Example 1 except that the plasticizer C-2 was used instead of the water-soluble polymer B-1.

[Example 5]
An exterior material was obtained in the same manner as in Example 1 except that the surfactant D-1 was used instead of the water-soluble polymer B-1.

[Example 6]
An exterior material was obtained in the same manner as in Example 1 except that the surfactant D-2 was used instead of the water-soluble polymer B-1.

[Example 7]
An exterior material was prepared in the same manner as in Example 1 except that a mixture of a plasticizer C-1 and a surfactant D-1 (solid content concentration ratio: 29: 1) was used instead of the water-soluble polymer B-1. Obtained.

[Example 8]
An exterior material was obtained in the same manner as in Example 1 except that the adhesive resin E-2 was used instead of the adhesive resin E-1.

[Example 9]
An exterior material was obtained in the same manner as in Example 1 except that the third adhesive layer was not provided.

[Comparative Example 1]
An exterior material was obtained in the same manner as in Example 1 except that the third adhesive layer 17 and the base material protective layer 18 were not formed.

[Comparative Example 2]
An exterior material was obtained in the same manner as in Example 1 except that the base material protective layer 18 was not formed.

[Comparative Example 3]
An exterior material was obtained in the same manner as in Example 1 except that the water-soluble polymer B-1 was not used for the base material protective layer 18.

[Comparative Example 4]
An exterior material was obtained in the same manner as in Example 1 except that the water-soluble polysaccharide A-1 was not used for the base material protective layer 18.

[Comparative Example 5]
An exterior material was obtained in the same manner as in Example 1 except that the water-soluble polysaccharide A-1 was not used for the base material protective layer 18 and the plasticizer C-1 was used instead of the water-soluble polymer B-1. It was.

[Comparative Example 6]
The exterior material was used in the same manner as in Example 1 except that the water-soluble polysaccharide A-1 was not used for the base material protective layer 18 and the surfactant D-1 was used instead of the water-soluble polymer B-1. Obtained.

[Evaluation of scratch resistance]
The outer surface (surface on the base material layer side) of the exterior material obtained in each example was rubbed by reciprocating 10 times with # 0000 steel wool (manufactured by Nippon Steel Wool) while applying a load of 150 g / cm ^2. The depth of the wound was measured with a displacement meter. The scratch resistance was evaluated according to the following criteria.
“◯”: The depth of the scratch on the surface is less than 1 μm.
“×”: The depth of the scratch on the surface is 1 μm or more.

[Evaluation of electrolyte resistance]
LiPF ₆ (relative to the mixed solution of ethylene carbonate / dimethyl carbonate / diethyl carbonate = 1/1/1 (mass ratio) on the outer surface (surface on the base material layer side) of the exterior material obtained in each example. Drop a few drops of electrolyte solution (lithium hexafluorophosphate) adjusted to 1.5 M and leave it in an environment of 25 ° C. and 65% RH for 24 hours to wipe off the electrolyte solution. Was confirmed by a laser microscope (manufactured by Olympus Corporation). The evaluation of electrolyte resistance was performed according to the following criteria.
“◯”: Surface alteration (whitening) is not observed.
“×”: Surface alteration (whitening) is observed.

[Evaluation of stretchability]
A strip-shaped test piece is cut out from the exterior material obtained in each example, and using a tensile tester (product name “4443”, manufactured by INSTRON), the sample width is 15 mm, the distance between the gauge points is 50 mm, and the tensile speed is 200 mm / min. Tensile tests were performed under the conditions described above, and the presence or absence of cracks was observed with a microscope (product name “LEXT”, manufactured by Olympus Corporation). The stretchability was evaluated according to the following criteria.
“◯”: No cracks are observed in the stretched portion.
"X": A crack is seen in the stretched part.

[Evaluation of electrolyte resistance after stretching]
An electrolyte solution (ethylene carbonate / dimethyl carbonate / diethyl carbonate = 1/1/1 (mass ratio) mixed solution on the outer surface (surface on the base material layer side) of the test piece after the tensile test described in the evaluation of stretchability On the other hand, several drops of LiPF ₆ (electrolytic solution prepared by adjusting and dissolving LiPF ₆ (lithium hexafluorophosphate) to be 1.5M) are dropped, and the same evaluation method and the same standard as the evaluation of the above-mentioned electrolytic solution resistance are applied. And evaluated.

[Evaluation of adhesion]
The exterior material obtained in each example was cut into a blank shape of 150 mm × 190 mm, cold-molded at a molding depth of 5 mm, and the presence or absence of peeling was confirmed. A punch having a shape of 100 mm × 150 mm, a punch corner R (RCP) of 1.5 mm, a punch shoulder R (RP) of 0.75 mm, and a die shoulder R (RD) of 0.75 mm was used. Evaluation was performed according to the following criteria.
“◯”: No peeling occurs by molding.
"X": Peeling occurs by molding.

  Table 1 shows the evaluation results of the materials used for the third adhesive layer and the base material protective layer in Examples and Comparative Examples, and the obtained exterior materials.

As shown in Table 1, Examples 1 to 9, which are exterior materials of the present invention, had sufficient scratch resistance, excellent stretchability, and excellent electrolyte resistance after stretching. Moreover, in Examples 1-9, the adhesiveness of a base material layer and a base material protective layer was also excellent.
In Comparative Examples 1-2, 4-5, sufficient scratch resistance and electrolyte resistance were not obtained. Comparative Example 3 had sufficient scratch resistance and electrolyte resistance, but was not sufficiently stretchable and did not have sufficient electrolyte resistance after stretching.

  The lithium ion battery exterior material of the present invention is a laminate type that has sufficient scratch resistance and electrolyte resistance, has excellent adhesion, stretchability, and moldability, and can maintain electrolyte resistance after stretching. It can be suitably used for lithium ion batteries.

DESCRIPTION OF SYMBOLS 1, 2 Lithium ion battery exterior material 11 Base material layer 12 1st adhesion layer 13 Metal foil layer 14 Corrosion prevention treatment layer 15 2nd adhesion layer 16 Sealant layer 17 3rd adhesion layer 18 Base material protection layer

Claims (4)

A base material layer made of nylon film;
A first adhesive layer provided on the first surface side of the base material layer;
A metal foil layer provided on the opposite side of the base layer of the first adhesive layer;
A corrosion prevention treatment layer provided on the opposite side of the metal foil layer from the first adhesive layer;
A second adhesive layer provided on the opposite side of the corrosion prevention treatment layer from the metal foil layer;
A sealant layer provided on the opposite side of the corrosion prevention treatment layer of the second adhesive layer;
A base material protective layer provided on the second surface side of the base material layer,
The substrate protective layer contains at least one selected from the group consisting of cellulose and cellulose derivatives, and selected from the group consisting of the following water-soluble polymer (B), plasticizer (C) and surfactant (D). The exterior material for lithium ion batteries characterized by containing the above-mentioned .
Water-soluble polymer (B): At least one solvent 100 selected from the group consisting of an aqueous alcohol solution containing 50% by mass of methanol, ethanol, propanol or isopropyl alcohol at 85 ° C., other than polysaccharides, and water A compound having a molecular weight of 10,000 or more that dissolves 1 part by mass or more with respect to parts by mass. A base material layer made of nylon film;
A first adhesive layer provided on the first surface side of the base material layer;
A metal foil layer provided on the opposite side of the base layer of the first adhesive layer;
A corrosion prevention treatment layer provided on the opposite side of the metal foil layer from the first adhesive layer;
A second adhesive layer provided on the opposite side of the corrosion prevention treatment layer from the metal foil layer;
A sealant layer provided on the opposite side of the corrosion prevention treatment layer of the second adhesive layer;
A third adhesive layer provided on the second surface side of the base material layer;
A base material protective layer provided on the side opposite to the base material layer of the third adhesive layer,
The substrate protective layer contains at least one selected from the group consisting of cellulose and cellulose derivatives, and selected from the group consisting of the following water-soluble polymer (B), plasticizer (C) and surfactant (D). The exterior material for lithium ion batteries characterized by containing the above-mentioned .
Water-soluble polymer (B): At least one solvent 100 selected from the group consisting of an aqueous alcohol solution containing 50% by mass of methanol, ethanol, propanol or isopropyl alcohol at 85 ° C., other than polysaccharides, and water A compound having a molecular weight of 10,000 or more that dissolves 1 part by mass or more with respect to parts by mass.   The third adhesive layer is at least one selected from the group consisting of phenol resin, urea resin, melamine resin, polyvinyl resin, polyolefin resin, urethane resin, epoxy resin, acrylic resin, polyester resin, polyamide resin, and polystyrene resin. The external packaging material for lithium ion batteries of Claim 2 containing the adhesive resin (E) of this.   The plasticizer (C) is a phthalate ester plasticizer, aromatic carboxylic ester plasticizer, aliphatic dibasic ester plasticizer, aliphatic ester plasticizer, phosphate ester plasticizer, epoxy The lithium according to any one of claims 1 to 3, which is at least one selected from the group consisting of a plasticizer, a chlorine-containing plasticizer, a polyester plasticizer, a glycol plasticizer, and a sugar alcohol plasticizer. Exterior material for ion batteries.

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