JP6459306B2 - Exterior materials for lithium-ion batteries - Google Patents

Description

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

As a secondary battery for consumer use used in portable terminal devices such as personal computers and mobile phones, and video cameras, lithium-ion batteries that are ultra-thin and miniaturized while being high energy have been actively developed.
As an outer packaging material of a lithium ion battery, a multilayer film (for example, a heat-resistant base material layer / aluminum, for example) can be used instead of a conventional metal can because it is lightweight and can freely select a battery shape. Foil layer / sealant (heat-bonding film) layer). Moreover, the exterior material using such a laminate film is not only flexible in the shape of the battery, but also lightweight, high heat dissipation, and low cost. Application to electric vehicle batteries is also being attempted.

A lithium ion battery using a laminate film type exterior material, for example, in a molded product obtained by deep drawing the above-described laminate film by cold molding, together with a positive electrode material, a negative electrode material, and a separator as a battery body portion, an electrolyte, Alternatively, an electrolyte layer made of a polymer gel impregnated with the electrolytic solution is accommodated and heat sealed by heat sealing. As the electrolytic solution, an electrolytic solution in which a lithium salt is dissolved in an aprotic solvent (propylene carbonate, ethylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, or the like) is used.
The electrolytic solution is highly permeable to the sealant layer. Therefore, in a lithium ion battery, the electrolyte solution that has penetrated into the sealant layer may reduce the laminate strength between the aluminum foil layer and the sealant layer, and the electrolyte solution may eventually leak out. In addition, lithium salts such as LiPF ₆ and LiBF ₄ that are electrolytes may generate hydrofluoric acid by a hydrolysis reaction. Hydrofluoric acid causes corrosion of the metal surface and a decrease in laminate strength between the layers of the laminate film. Therefore, the exterior material is required to have a corrosion prevention performance against an electrolytic solution and hydrofluoric acid.
In order to provide corrosion prevention performance against electrolytic solution and hydrofluoric acid in response to such demands, the aluminum foil surface may be subjected to corrosion prevention treatment such as degreasing treatment, hydrothermal transformation treatment, anodizing treatment, and chemical conversion treatment. Has been done.

As described above, excellent formability is required for an exterior material that is deep-drawn by cold forming. In other words, since the energy density is determined depending on how the cells and electrolyte can be accommodated in the lithium ion battery, in order to increase the capacity, the molding depth can be increased when the exterior material is molded into a battery shape. We need to be deep.
Molding of the exterior material is generally performed by cold molding (deep drawing molding) using a mold, but if the molding depth is too deep at this time, cracks and pinholes will occur in the stretched part by molding, and as a battery Is unreliable. Therefore, it is important how the molding depth can be increased without impairing reliability. In particular, in large-scale applications such as electric vehicles, there is a demand for higher energy density from the viewpoint of battery performance for taking out a large current, but excellent reliability and long-term storage stability are also required.

  It is known that the formability in cold forming is affected by the slipperiness of the exterior material with respect to the cold forming mold. Therefore, in order to improve the slipperiness of the exterior material, a slip agent is used. For example, an exterior material (Patent Document 1) in which the outer surface of a biaxially stretched polyester film layer, which is a base material layer, is subjected to silicone treatment and the dynamic friction coefficient of the surface is 0.3 or less, and at least the fatty acid on the surface of the base material layer An exterior material coated or sprayed with an amide-based slip agent (Patent Documents 2 and 3), a predetermined amount of slip agent is added to the film forming the sealant layer, and after lamination during the production of the exterior material, the aging temperature and time are set. By controlling, the exterior material (patent document 4) etc. which bleeded out the slip agent and expressed slipperiness, improving the contact | adherence performance with aluminum are proposed.

On the other hand, in the manufacturing process of a lithium ion battery, a barcode, a logo, or the like is printed on the outer surface of the exterior material by a method such as inkjet for lot tracing or the like. In addition, the outer surface of the exterior material may be subjected to special processing such as mat processing in order to improve design properties and prevent counterfeiting.
However, special processing on the outer surface tends to cause disadvantages such as a decrease in moldability, electrolyte resistance, and deterioration in printability. For example, printing cannot be performed stably, and printing defects such as ink bleeding tend to occur. Since a printing failure causes a barcode reading failure or the like, the exterior material is required to have printability capable of stably printing on the outer surface.
The exterior materials of Patent Documents 1 to 4 have a problem that printability deteriorates when trying to obtain excellent moldability. For example, if a slip agent such as silicone or fatty acid amide is attached to the surface of the base material layer, ink bleeding occurs when printing on the surface, and good printing cannot be obtained.
For such a problem, as an exterior material capable of achieving both formability and barcode printability, an aluminum foil layer provided with a first adhesive layer on one side of the base material layer and a corrosion prevention treatment layer on at least one side; The static friction coefficient (μs-A) of the outer surface of the base material layer in the exterior material for a lithium ion battery in which the second adhesive layer and the sealant layer are sequentially laminated is 0.1 to 0.25, and the outer surface of the sealant layer is An exterior material having a static friction coefficient (μs-B) of 0.1 to 0.5 has been proposed (Patent Document 5). However, there is still room for improvement in the printability of the exterior material of Patent Document 5.

JP 2002-56824 A JP 2002-216713 A JP 2002-216714 A JP 2005-32456 A JP 2012-124068 A

  This invention is made | formed in view of the said situation, and it aims at providing the exterior material for lithium ion batteries which has the outstanding printability.

The present invention for solving the above problems has the following aspects.
[1] At least one base material layer, a first adhesive layer, an aluminum foil layer provided with a corrosion prevention treatment layer on at least one surface, an adhesive resin layer or a second adhesive layer, and a sealant A layered structure in which the layers are laminated in this order, and a lithium ion battery exterior material on which printing is performed on the surface on the base material layer side,
When a droplet of an ink solvent contained in the ink used for printing is deposited on the surface of the base material layer, the contact angle after 10 seconds from the deposition of the droplet is 10 ° or more and 30 An exterior material for a lithium ion battery, characterized in that the change in the contact angle in 5 seconds from the landing of the droplet is 6 ° or less.
[2] A surface treatment is applied to the surface of the base material layer, and the contact treatment results in the contact angle being 10 ° to 30 ° and the change in the contact angle being 6 ° or less. [1 ] The exterior material for lithium ion batteries as described in any one of Claims 1-3.
[3] The exterior material for a lithium ion battery according to [2], wherein the surface treatment is application of a surface modifier.
[4] The exterior material for a lithium ion battery according to [3], wherein the surface modifier is silicone oil.
[5] The exterior material for a lithium ion battery according to any one of [1] to [4], wherein the printing is inkjet printing.
[6] The external packaging material for a lithium ion battery according to any one of [1] to [5], wherein the ink solvent is an organic solvent.
[7] The lithium ion battery exterior material according to [6], wherein the ink solvent is methyl ethyl ketone or a mixed solvent containing methyl ethyl ketone as a main component.

  ADVANTAGE OF THE INVENTION According to this invention, the exterior material for lithium ion batteries which has the outstanding printability can be provided.

It is a schematic sectional drawing of the exterior material for lithium ion batteries of 1st Embodiment of this invention. It is a schematic sectional drawing of the exterior material for lithium ion batteries of 2nd Embodiment of this invention. It is a schematic sectional drawing of the exterior material for lithium ion batteries of 3rd Embodiment of this invention.

The lithium ion battery exterior material of the present invention (hereinafter sometimes simply referred to as “exterior material”) includes at least one base material layer, a first adhesive layer, and a corrosion prevention treatment layer on at least one surface. The aluminum foil layer provided, an adhesive resin layer or a second adhesive layer, and a sealant layer are formed from a laminate that is laminated in this order.
The exterior material can exhibit the performance required for the exterior material for a lithium ion battery by having such a layer structure.
The exterior material is used with the base material layer as the outermost layer and the sealant layer as the innermost layer.
In the exterior material of the present invention, the corrosion prevention treatment layer may be provided on one side or both sides of the aluminum foil layer. From the viewpoint of resistance to electrolytic solution, it is preferable that a corrosion prevention treatment layer is provided at least on the sealant layer side (innermost layer side).
A base treatment layer may be provided on the base material layer side (outermost layer side) of the aluminum foil layer. Thereby, the adhesiveness between a base material layer and an aluminum foil layer improves further, and the moldability of an exterior material and the adhesiveness in electrolyte solution atmosphere improve.

  The exterior material of the present invention is printed on the surface on the base material layer side, that is, the outermost layer side surface. For example, after manufacturing a lithium ion battery using an exterior material, a bar coat, a logo, or the like is printed on the surface of the exterior material on the base material layer side (the outer surface of the lithium ion battery).

The exterior material according to the present invention has a structure in which a droplet of an ink solvent contained in the ink used for printing is deposited on the surface of the substrate layer side after 5 seconds from the deposition of the droplet. The contact angle (hereinafter also referred to as “the contact angle after 5 seconds”) is 10 ° or more and 30 ° or less, and the change in the contact angle in 5 seconds after the landing of the droplet (hereinafter “the change in the contact angle with time ( 5 seconds) ”) is 6 ° or less. Thereby, the exterior material of this invention has the outstanding printability.
The contact angle after 5 seconds is preferably 15 ° or more and 25 ° or less.
The time change (5 seconds) of the contact angle is preferably 3 ° or less.

If the contact angle after 5 seconds is less than 10 °, the ink is too wet and printing failure due to ink bleeding tends to occur. For example, in ink jet printing in which ink droplets are directly sprayed onto the printing surface (surface on the base material layer side), ink bleeding may occur and the shape may not be maintained. If the contact angle after 5 seconds exceeds 30 °, printing failure due to ink repellency tends to occur.
When the time change (5 seconds) of the contact angle exceeds 6 °, there is a possibility that appropriate printing cannot be performed when a design or a barcode is printed on the surface of the base material layer side using ink. That is, it takes several seconds to apply ink to the surface and dry the ink. If the wettability of the ink on the surface (contact angle with respect to the ink) greatly changes before the ink is dried, ink bleeding or repellency may occur on the surface.

The contact angle is an angle formed between a solid surface and a tangent to the liquid surface at a point where a solid having a horizontal plane and a liquid (droplet) dropped on the horizontal plane come into contact, and is defined as an angle on the side including the liquid. Is done.
In the present invention, the contact angle is measured in an environment of 23 ° C. and 50% RH, and the amount of liquid droplets deposited on the surface of the base material layer is 4 μL.
The change in the contact angle over time (5 seconds) is determined based on the contact angle at the time when the droplet has landed on the surface of the base material layer side and the contact angle at the time 5 seconds after the droplet has landed (5 The absolute value of the difference from the contact angle in seconds). The point of time when the droplet has landed indicates the point in time when the shape of the droplet is fixed.

The contact angle after 5 seconds and the time change (5 seconds) of the contact angle can be adjusted by the film constituting the base material layer disposed in the outermost layer of the exterior material.
For example, by selecting the film material, film formation method, film formation conditions, presence / absence of stretching treatment, presence / absence of surface treatment, and the type and degree of the treatment, etc. And the time change (5 seconds) of the contact angle can be adjusted.

Examples of the surface treatment include application of a surface modifier to the surface (surface on which printing is performed) constituting the base material layer, surface modification treatment such as corona treatment, plasma treatment, and the like.
When the solvent of the ink is an organic solvent (for example, methyl ethyl ketone), the contact angle after 5 seconds is usually increased by applying a surface modifier, and the contact angle after 5 seconds is increased by corona treatment or plasma treatment. There is a tendency to become smaller. For example, even if the contact angle after 5 seconds on the surface of the film before the surface treatment is less than 10 °, the contact angle after 5 seconds is 10 ° or more by applying an appropriate amount of the surface modifier. 30 ° or less, and the time change (5 seconds) of the contact angle may be 6 ° or less. Further, even if the contact angle after 5 seconds on the surface of the film before the surface treatment is more than 30 °, the contact angle after 5 seconds is 10 ° or more and 30 ° or less when the corona treatment is performed. The time change of the corner (5 seconds) can be 6 ° or less.

  Examples of the surface modifier include silicone oil and fluorine compounds. As the surface modifier, silicone oil is preferable from the viewpoint of water repellency control, and in particular, non-reactive such as alkyl-modified silicone oil, higher fatty acid ester-modified silicone oil, polyether-modified silicone oil, etc. from the viewpoint of compatibility with solvents. Sex modified silicone oil is preferred. These may be used alone or in combination of two or more.

In the above-mentioned Patent Document 1, silicone oil is used to improve the slipperiness of the exterior material, but printability is not considered. That is, in Patent Document 1, the higher the slipping property, in other words, the lower the dynamic friction coefficient, the better.
However, in the present invention, the contact angle must be within a predetermined range. If the amount of silicone oil is too large, ink repellency will occur and printability will deteriorate. Therefore, it is preferable to use a surface modifier such as silicone oil and a slip agent such as fatty acid amide in order to achieve both slipperiness and printability.

A plurality of surface treatments may be combined. For example, you may combine application | coating of a surface modifier, and surface modification processes, such as a corona treatment and a plasma treatment.
In the case where the surface treatment is performed, the film constituting the substrate preferably has a change in the contact angle with time (5 seconds) of 6 ° or less before the surface treatment.
A protective layer or the like may be formed on the surface of the film constituting the substrate.

  Hereinafter, an exterior material according to the present invention will be described with reference to the accompanying drawings.

[First Embodiment]
FIG. 1 is a schematic cross-sectional view of an exterior material 1 according to the first embodiment of the present invention.
The exterior material 1 is made of a laminate in which a first adhesive layer 12, an aluminum foil layer 13, an adhesive resin layer 15, and a sealant layer 16 are laminated on one surface of a base material layer 11 in this order. The corrosion prevention treatment layer 14 is provided on the surface of the aluminum foil layer 13 on the sealant layer 16 side.
The exterior material 1 is printed on the surface of the base material layer 11 opposite to the first adhesive layer 12 side, that is, the surface 1a of the exterior material 1 on the base material layer 11 side. When a droplet of an ink solvent contained in the ink used for printing is deposited on the surface 1a, the contact angle after 5 seconds is 10 ° or more and 30 ° or less, and the contact angle changes with time (5 seconds). Is 6 ° or less.

(Base material layer)
The base material layer 11 plays a role of imparting heat resistance in a heat sealing process when manufacturing a lithium ion battery, suppressing generation of pinholes that may occur during molding processing and distribution, and the like. In particular, in the case of an exterior material for a large-sized lithium ion battery, scratch resistance, chemical resistance, insulation, and the like can be imparted.
As the base material layer 11, a resin film formed of an insulating resin is preferable. Examples of the resin film include stretched or unstretched films such as polyester films, polyamide films, and polypropylene films.
The base material layer 11 may be one layer or two or more layers. For example, the base material layer 11 may be a single layer resin layer composed of any one of the above resin films, or may be a multi-layer resin layer in which two or more of the above resin films are laminated. Good. Examples of these resin layers include stretched or unstretched polyamide films, stretched or unstretched polyester films, and two-layer films of stretched polyamide films and stretched polyester films.
As the base material layer 11, a resin layer having a single layer structure or a multilayer structure including a stretched polyamide film is particularly preferable in terms of excellent moldability and heat resistance. Furthermore, the resin layer of the multilayer structure containing a stretched polyamide film is preferable at the point which can provide acid resistance, and the two-layer film of a stretched polyamide film and a stretched polyester film is especially preferable.

  The thickness of the base material layer 11 is preferably 6 μm or more, and more preferably 10 μm or more in terms of improving moldability, heat resistance, pinhole resistance, and insulation. Moreover, 60 micrometers or less are preferable and 45 micrometers or less are more preferable at the point of thin film formation and high heat dissipation. When the base material layer 11 is a resin layer having a multilayer structure, the thickness is the total thickness.

Various additives such as a surface modifier, an acid resistance-imparting agent, a difficulty are applied to the surface of the base material layer 11 opposite to the first adhesive layer 12 side (surface 1a on the outermost layer side of the exterior material 1). A flame retardant, slip agent, anti-blocking agent, antioxidant, light stabilizer, tackifier and the like may be applied. Further, surface modification treatment such as corona treatment and plasma treatment may be performed.
The surface modifier is the same as that mentioned above.
Examples of the acid resistance imparting agent include polyvinylidene chloride, vinylidene chloride-vinyl chloride copolymer, maleic anhydride-modified polypropylene, polyester resin, epoxy resin, phenol resin, fluororesin, cellulose ester, urethane resin, acrylic resin, and the like. .
Examples of the slip agent include fatty acid amides such as oleic acid amide, erucic acid amide, stearic acid amide, behenic acid amide, ethylene bisoleic acid amide, and ethylene biserucic acid amide.
As the antiblocking agent, various fillers such as silica are suitable.
These additives may be used alone or in combination of two or more.

(First adhesive layer)
The first adhesive layer 12 is a layer that bonds the base material layer 11 and the aluminum foil layer 13 together.
The 1st adhesive bond layer 12 can be formed using a well-known thing as an adhesive agent used for the lamination of a resin film and aluminum foil. Examples of the adhesive include a polyurethane-based adhesive containing a main agent composed of a polyol such as polyester polyol, polyether polyol, acrylic polyol, and carbonate polyol, and a curing agent composed of a bifunctional or higher functional isocyanate compound. A polyurethane-based resin is formed by allowing the curing agent to act on the main agent.

As the polyester polyol, one obtained by reacting at least one polybasic acid with at least one diol can be used. Polybasic acids include succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, brassic acid and other aliphatic dibasic acids, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid and other aromatics And dibasic acids such as group dibasic acids. Diols include ethylene glycol, propylene glycol, butanediol, neopentyl glycol, methylpentanediol, hexanediol, heptanediol, octanediol, nonanediol, decanediol, dodecanediol and other aliphatic diols, cyclohexanediol, hydrogenated xylylene Examples thereof include alicyclic diols such as lenglycol and aromatic diols such as xylylene glycol.
Further, as the polyester polyol, a hydroxyl group at both ends of the polyester polyol, a polyester urethane polyol in which chain is extended using an isocyanate compound alone or an adduct body, a burette body or an isocyanurate body made of at least one isocyanate compound, etc. Can be mentioned. Examples of the isocyanate compound include 2,4- or 2,6-tolylene diisocyanate, xylylene diisocyanate, 4,4′-diphenylmethane diisocyanate, methylene diisocyanate, isopropylene diisocyanate, lysine diisocyanate, 2,2,4- or 2, Examples include 4,4-trimethylhexamethylene diisocyanate, 1,6-hexamethylene diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, and isopropylidene dicyclohexyl-4,4′-diisocyanate.

  As the polyether polyol, it is possible to use an ether-based polyol such as polyethylene glycol or polypropylene glycol, or a polyether urethane polyol in which the above-described isocyanate compound is allowed to act as a chain extender.

Examples of the acrylic polyol include a copolymer containing poly (meth) acrylic acid as a main component. Examples of the copolymer include hydroxyl group-containing monomers such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate, and methyl groups, ethyl groups, n-propyl groups, i-propyl groups as alkyl groups. Group, n-butyl group, i-butyl group, t-butyl group, 2-ethylhexyl group, cyclohexyl group, alkyl (meth) acrylate monomer, and (meth) acrylamide, N-alkyl (meth) acrylamide, N, N-dialkyl (meth) acrylamide (As the alkyl group, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, t-butyl group, 2-ethylhexyl group) Cyclohexyl group, etc.), N-alkoxy (meth) acrylamide, N, N-dialkoxy (meta) Acrylamide, (as alkoxy groups, methoxy group, ethoxy group, butoxy group, isobutoxy group, etc.), amide group-containing monomers such as N-methylol (meth) acrylamide, N-phenyl (meth) acrylamide, glycidyl (meth) acrylate, Glycidyl group-containing monomers such as allyl glycidyl ether,
Examples include those obtained by copolymerizing silane-containing monomers such as (meth) acryloxypropyltrimethoxysilane and (meth) acryloxypropyltriethoxylane, and isocyanate group-containing monomers such as (meth) acryloxypropyl isocyanate.

As the carbonate polyol, one obtained by reacting a carbonate compound and a diol can be used. As the carbonate compound, dimethyl carbonate, diphenyl carbonate, ethylene carbonate, or the like can be used. Examples of the diol include ethylene glycol, propylene glycol, butanediol, neopentyl glycol, methylpentanediol, hexanediol, heptanediol, octanediol, nonanediol, decanediol, dodecanediol, and other aliphatic diols, cyclohexanediol, hydrogenated Arocyclic diols such as xylylene glycol and aromatic diols such as xylylene glycol can be used.
Further, it is possible to use a polycarbonate urethane polyol in which the terminal hydroxyl group of the carbonate polyol is chain-extended with the above-described isocyanate compound.
These various polyols may be used alone or in the form of a blend of two or more depending on the required function and performance.

As the bifunctional or higher functional isocyanate compound used as the curing agent, it is possible to use the type of isocyanate compound used as a chain extender, and although it is repeated, 2,4- or 2,6-tolylene diisocyanate , Xylylene diisocyanate, 4,4′-diphenylmethane diisocyanate, methylene diisocyanate, isopropylene diisocyanate, lysine diisocyanate, 2,2,4- or 2,4,4-trimethylhexamethylene diisocyanate, 1,6-hexamethylene diisocyanate, methyl Isocyanate selected from cyclohexane diisocyanate, isophorone diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, isopropylidene dicyclohexyl-4,4′-diisocyanate, etc. Single sulfonate compounds, or adducts of at least one isocyanate compound selected from the isocyanate compound, biuret body, isocyanurate products thereof.
As a compounding quantity of a hardening | curing agent, 1-100 mass parts is preferable with respect to 100 mass parts of main agents, and 5-50 mass parts is more preferable. If the amount is less than 1 part by mass, the performance may not be exhibited in terms of adhesion and electrolyte resistance. If the amount is more than 100 parts by mass, an excess of isocyanate groups will be present, which may affect the adhesive film quality due to the residual unreacted substances and the hardness.

It is also possible to mix a carbodiimide compound, an oxazoline compound, an epoxy compound, a phosphorus compound, a silane coupling agent, and the like with the polyurethane adhesive for promoting adhesion.
Examples of the carbodiimide compound include N, N′-di-o-toluylcarbodiimide, N, N′-diphenylcarbodiimide, N, N′-di-2,6-dimethylphenylcarbodiimide, N, N′-bis (2,6 -Diisopropylphenyl) carbodiimide, N, N'-dioctyldecylcarbodiimide, N-triyl-N'-cyclohexylcarbodiimide, N, N'-di-2,2-di-t-butylphenylcarbodiimide, N-triyl-N ' -Phenylcarbodiimide, N, N'-di-p-nitrophenylcarbodiimide, N, N'-di-p-aminophenylcarbodiimide, N, N'-di-p-hydroxyphenylcarbodiimide, N, N'-di- Examples thereof include cyclohexylcarbodiimide and N, N′-di-p-toluylcarbodiimide.

  As the oxazoline compound, monooxazoline compounds such as 2-oxazoline, 2-methyl-2-oxazoline, 2-phenyl-2-oxazoline, 2,5-dimethyl-2-oxazoline, 2,4-diphenyl-2-oxazoline, 2,2 ′-(1,3-phenylene) -bis (2-oxazoline), 2,2 ′-(1,2-ethylene) -bis (2-oxazoline), 2,2 ′-(1,4- And dioxazoline compounds such as butylene) -bis (2-oxazoline) and 2,2 ′-(1,4-phenylene) -bis (2-oxazoline).

  Epoxy compounds include diglycidyl ethers of aliphatic diols such as 1,6-hexanediol, neopentyl glycol, polyalkylene glycol, sorbitol, sorbitan, polyglycerol, pentaerythritol, diglycerol, glycerol, trimethylolpropane, etc. Polyglycidyl ether of aliphatic polyols, polyglycidyl ether of alicyclic polyols such as cyclohexanedimethanol, aliphatic and aromatic such as terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, trimellitic acid, adipic acid, sebacic acid Diglycidyl ester or polyglycidyl ester of polycarboxylic acid, resorcinol, bis- (p-hydroxyphenyl) methane, 2,2-bis- (p-hydroxyphenyl) propa , Diglycidyl ether or polyglycidyl ether of polyhydric phenols such as tris- (p-hydroxyphenyl) methane, 1,1,2,2-tetrakis (p-hydroxyphenyl) ethane, N, N′-diglycidylaniline, N-glycidyl derivatives of amines such as N, N, N-diglycidyl toluidine, N, N, N ′, N′-tetraglycidyl-bis- (p-aminophenyl) methane, triglycidyl derivatives of aminofail, tri Examples thereof include glycidyl tris (2-hydroxyethyl) isocyanurate, triglycidyl isocyanurate, orthocresol type epoxy, and phenol novolac type epoxy.

  Examples of the phosphorus compound include tris (2,4-di-t-butylphenyl) phosphite, tetrakis (2,4-di-t-butylphenyl) 4,4′-biphenylenephosphonite, bis (2,4- Di-t-butylphenyl) pentaerythritol-di-phosphite, bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol-di-phosphite, 2,2-methylenebis (4,6- Di-t-butylphenyl) octyl phosphite, 4,4′-butylidene-bis (3-methyl-6-tert-butylphenyl-di-tridecyl) phosphite, 1,1,3-tris (2-methyl- 4-ditridecyl phosphite-5-tert-butyl-phenyl) butane, tris (mixed mono and di-nonylphenyl) phosphite, tris (nonyl) Eniru) phosphite, 4,4'-isopropylidene-bis (phenyl - dialkyl phosphite), and the like.

As silane coupling agents, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxy Propyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-chloropropylmethoxysilane, vinyltrichlorosilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β Various silane coupling agents such as (aminoethyl) -γ-aminopropyltrimethoxysilane can be used.
In addition, various additives and stabilizers may be blended according to the performance required for the adhesive.

  1-10 micrometers is preferable and, as for the thickness of the 1st adhesive bond layer 12, 3-5 micrometers is more preferable. When it is 1 μm or more, the laminate strength as an adhesive is improved, and when it is 10 μm or less, when the exterior material 1 is made into a deep-drawn molded product by cold forming, also in the drawn corner of the deep-drawn molded product. Moreover, the float between the base material layer 11-aluminum foil layer 13 in electrolyte solution atmosphere can fully be suppressed.

(Aluminum foil layer)
As the aluminum foil constituting the aluminum foil layer 13, a commonly used soft aluminum foil can be used. For the purpose of imparting further pinhole resistance and extensibility during molding, it is preferable to use an aluminum foil containing iron.
0.1-9.0 mass% is preferable and, as for content of iron in aluminum foil (100 mass%), 0.5-2.0 mass% is more preferable. When the iron content is 0.1% by mass or more, pinhole resistance and ductility are sufficiently imparted, and when it is 9.0% by mass or less, flexibility is good.
The thickness of the aluminum foil layer 13 is preferably 9 to 200 μm and more preferably 15 to 100 μm from the viewpoint of barrier properties, pinhole resistance, and workability.

The aluminum foil layer 13 is preferably made of an aluminum foil that has been subjected to a degreasing treatment from the viewpoint of resistance to electrolytic solution.
The degreasing treatment can be roughly classified into a wet type and a dry type.
Examples of the wet type degreasing treatment include acid degreasing and alkali degreasing. Examples of the acid used for acid degreasing include inorganic acids such as sulfuric acid, nitric acid, hydrochloric acid, and hydrofluoric acid. These acids may be used individually by 1 type, and may use 2 or more types together. Moreover, you may mix | blend various metal salts used as supply sources, such as Fe ion and Ce ion, with these inorganic acids as needed from the point which the etching effect of aluminum foil improves. As an alkali used for alkali degreasing, sodium hydroxide etc. are mentioned as a thing with a high etching effect, for example. Moreover, what mix | blended weak alkali type and surfactant is mentioned. The wet type degreasing treatment is performed by an immersion method or a spray method.
Examples of the dry type degreasing treatment include a method of performing in an aluminum annealing step. In addition, flame treatment, corona treatment, degreasing treatment in which contaminants are oxidatively decomposed and removed by active oxygen generated by irradiation with ultraviolet rays having a specific wavelength, and the like are also included.
The degreasing treatment may be performed on one side or both sides of the aluminum foil.

(Corrosion prevention treatment layer)
The corrosion prevention treatment layer 14 is basically a layer provided to prevent the aluminum foil layer 13 from being corroded by the electrolytic solution or hydrofluoric acid.
Examples of the corrosion prevention treatment include a degreasing treatment, a hydrothermal alteration treatment, an anodizing treatment, a chemical conversion treatment, a coating type corrosion prevention treatment in which a coating agent having corrosion prevention performance is applied, or a combination of two or more of these treatments. .
Of the above-mentioned treatments, degreasing treatment, hydrothermal modification treatment, anodizing treatment, particularly hydrothermal modification treatment and anodizing treatment are performed by dissolving the surface of the metal foil (aluminum foil) with a treating agent, and an aluminum compound having excellent corrosion resistance ( In order to form a co-continuous structure from the metal foil to the corrosion prevention treatment layer, there are cases where it is included in the definition of chemical conversion treatment. It is also possible to form the corrosion prevention treatment layer 14 only by a pure coating treatment not included in the definition of the chemical conversion treatment, such as a method using a coating agent containing a product sol.

Degreasing treatment includes acid degreasing and alkali degreasing. Examples of the acid degreasing include a method using the above-described inorganic acid such as sulfuric acid, nitric acid, hydrochloric acid and hydrofluoric acid alone or a mixture thereof. Also, as acid degreasing, by using an acid degreasing agent in which a fluorine-containing compound such as monosodium ammonium difluoride is dissolved with the above-mentioned inorganic acid, not only the degreasing effect of the metal foil but also a metal fluoride that is passive is formed. This is effective in terms of resistance to hydrofluoric acid. Examples of the alkaline degreasing include a method using sodium hydroxide and the like.
Examples of the hydrothermal modification treatment include boehmite treatment obtained by immersing a metal foil in boiling water to which triethanolamine is added.
Examples of the anodizing treatment include alumite treatment.
Examples of the chemical conversion treatment include a chromate treatment, a zirconium treatment, a titanium treatment, a vanadium treatment, a molybdenum treatment, a calcium phosphate treatment, a strontium hydroxide treatment, a cerium treatment, a ruthenium treatment, and various chemical conversion treatments composed of these mixed phases.
These hydrothermal modification treatment, anodizing treatment, and chemical conversion treatment are preferably performed in advance with the above-described degreasing treatment. These chemical conversion treatments are not limited to the wet type, but can be applied to a coating type in which these treatment agents are mixed with a resin component.

The coating agent used in the coating type corrosion prevention treatment for coating the coating agent having the corrosion prevention performance contains at least one selected from the group consisting of rare earth oxide sols, anionic polymers, and cationic polymers. Things. In particular, a method using a coating agent containing a rare earth element oxide sol is preferable.
The method using a coating agent containing a rare earth element oxide sol is a pure coating type corrosion prevention treatment, and this method can impart a corrosion prevention effect to a metal foil even with a general coating method. Is possible. In addition, the layer formed using the rare earth element oxide sol has a corrosion prevention effect (inhibitor effect) of the metal foil, and is also a suitable material from the environmental viewpoint.
The rare earth element oxide sol is obtained by dispersing rare earth element oxide fine particles (for example, particles having an average particle diameter of 100 nm or less) in a liquid dispersion medium.
Examples of rare earth element oxides include cerium oxide, yttrium oxide, neodymium oxide, and lanthanum oxide. Of these, cerium oxide is preferred.
As the liquid dispersion medium of the rare earth element oxide sol, various solvents such as water, alcohol solvents, hydrocarbon solvents, ketone solvents, ester solvents, ether solvents and the like can be used. Of these, water is preferred.

In order to stabilize the dispersion of rare earth element oxide particles, rare earth element oxide sols are used as dispersion stabilizers, such as inorganic acids such as nitric acid, hydrochloric acid and phosphoric acid, and organic substances such as acetic acid, malic acid, ascorbic acid and lactic acid. It is preferable to contain acids, salts thereof and the like.
Among these dispersion stabilizers, phosphoric acid or phosphate, in particular, not only stabilizes dispersion of rare earth element oxide particles, but also uses the chelating ability of phosphoric acid in the application of exterior materials for lithium ion batteries. Rare earth element oxide layer due to improved adhesion to aluminum foil, addition of electrolyte resistance by trapping (passivation formation) of metal ions eluted under the influence of hydrofluoric acid, and easy dehydration condensation of phosphoric acid even at low temperatures It is preferable because the effect of improving the cohesive strength of the resin can be expected.
Examples of phosphoric acid or phosphate used as a dispersion stabilizer include orthophosphoric acid, pyrophosphoric acid, metaphosphoric acid, and alkali metal salts and ammonium salts thereof.
As phosphoric acid or phosphate, condensed phosphoric acid such as trimetaphosphoric acid, tetrametaphosphoric acid, hexametaphosphoric acid, ultrametaphosphoric acid, or alkali metal salts or ammonium salts thereof are used for the functional expression as a lithium ion battery exterior material. preferable. In particular, considering the dry film-forming properties (drying capacity, heat quantity) when forming a layer containing rare earth oxides by various coating methods using a coating composition containing rare earth element oxide sol, the reactivity at low temperature In view of excellent dehydration condensation properties at low temperatures, sodium salts are preferred. As the phosphate, a water-soluble salt is preferable.
The blending amount of phosphoric acid or a salt thereof in the rare earth element oxide sol is preferably 1 part by mass or more and more preferably 5 parts by mass or more with respect to 100 parts by mass of the rare earth element oxide. When the content is 1 part by mass or more, the sol is stabilized well and it is easy to satisfy the function as an exterior material for a lithium ion battery. The upper limit of the phosphoric acid or salt thereof added to 100 parts by mass of the rare earth element oxide may be in a range not accompanied by a decrease in the function of the rare earth element oxide sol, and is 100 parts by mass or less with respect to 100 parts by mass of the rare earth element oxide. Preferably, 50 parts by mass or less is more preferable, and 20 parts by mass or less is more preferable.

However, since the layer formed from the rare earth element oxide sol described above is an aggregate of inorganic particles, the cohesive force of the layer itself is low even after the drying curing process. Therefore, in order to supplement the cohesive strength of this layer, it is preferable to make a composite with an anionic polymer.
As an anionic polymer, the polymer which has a carboxy group is mentioned, For example, the copolymer which copolymerized poly (meth) acrylic acid (or its salt) or poly (meth) acrylic acid as a main component is mentioned.
The copolymer component of the copolymer includes an alkyl (meth) acrylate monomer (the alkyl group includes a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, t-butyl group, 2-ethylhexyl group, cyclohexyl group, etc.); (meth) acrylamide, N-alkyl (meth) acrylamide, N, N-dialkyl (meth) acrylamide (alkyl groups include methyl, ethyl, n-propyl group, i-propyl group, n-butyl group, i-butyl group, t-butyl group, 2-ethylhexyl group, cyclohexyl group, etc.), N-alkoxy (meth) acrylamide, N, N-dialkoxy (Meth) acrylamide (as the alkoxy group, methoxy group, ethoxy group, butoxy group, isobutoxy group, etc.), N-methyl Amide group-containing monomers such as diol (meth) acrylamide and N-phenyl (meth) acrylamide; Hydroxyl-containing monomers such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate; Glycidyl (meth) acrylate, Glycidyl group-containing monomers such as allyl glycidyl ether; silane-containing monomers such as (meth) acryloxypropyltrimethoxysilane and (meth) acryloxypropyltriethoxylane; isocyanate group-containing monomers such as (meth) acryloxypropyl isocyanate Can be mentioned. Also, styrene, α-methylstyrene, vinyl methyl ether, vinyl ethyl ether, maleic acid, alkyl maleic acid monoester, fumaric acid, alkyl fumaric acid monoester, itaconic acid, alkyl itaconic acid monoester, (meth) acrylonitrile, chloride Examples include vinylidene, ethylene, propylene, vinyl chloride, vinyl acetate, and butadiene.

An anionic polymer plays the role which improves the stability of the corrosion prevention process layer 14 (rare earth element oxide layer) obtained using the rare earth element oxide sol. This is achieved by the effect of protecting the hard and brittle rare earth element oxide layer with a polymer, and the effect of capturing ion contamination (especially sodium ions) derived from phosphate contained in the rare earth oxide sol (cation catcher). The That is, when an alkali metal ion such as sodium or an alkaline earth metal ion is contained in the corrosion prevention treatment layer 14 obtained by using the rare earth element oxide sol, the corrosion prevention starts from the place containing the ion. The processing layer 14 is likely to deteriorate. Therefore, the resistance of the corrosion prevention treatment layer 14 is improved by fixing sodium ions and the like contained in the rare earth oxide sol by the anionic polymer.
The corrosion prevention treatment layer 14 combined with the anionic polymer and the rare earth element oxide sol has the same corrosion prevention performance as the corrosion prevention treatment layer 14 formed by subjecting the aluminum foil to chromate treatment.

The anionic polymer preferably has a structure in which a polyanionic polymer that is essentially water-soluble is crosslinked.
As a crosslinking agent used for formation of this structure, the compound which has an isocyanate group, a glycidyl group, a carboxy group, and an oxazoline group is mentioned, for example. Furthermore, it is also possible to introduce a crosslinking site having a siloxane bond using a silane coupling agent.

  Examples of the compound having an isocyanate group include diisocyanates such as tolylene diisocyanate, xylylene diisocyanate or hydrogenated products thereof, hexamethylene diisocyanate, 4,4′-diphenylmethane diisocyanate or hydrogenated products thereof, isophorone diisocyanate; Polyisocyanates such as adducts obtained by reacting isocyanates with polyhydric alcohols such as trimethylolpropane, burettes obtained by reacting with water, or isocyanurates which are trimers; or these Examples thereof include blocked polyisocyanates obtained by blocking polyisocyanates with alcohols, lactams, oximes and the like.

  Examples of the compound having a glycidyl group include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, 1,4-butanediol, 1,6-hexanediol, Epoxy compounds in which epichlorohydrin is allowed to act on glycols such as neopentyl glycol, glycerin, polyglycerol, trimethylolpropane, pentaerythritol, sorbitol, etc. and epoxy compounds in which epichlorohydrin is allowed to act on, phthalic acid, terephthalic acid, Examples thereof include an epoxy compound obtained by reacting a dicarboxylic acid such as oxalic acid or adipic acid with epichlorohydrin.

Examples of the compound having a carboxy group include various aliphatic or aromatic dicarboxylic acids, and it is also possible to use poly (meth) acrylic acid or alkali (earth) metal salts of poly (meth) acrylic acid. is there.
As the compound having an oxazoline group, for example, a low molecular compound having two or more oxazoline units, or a polymerizable monomer such as isopropenyl oxazoline, (meth) acrylic acid, (meth) acrylic acid alkyl ester And those obtained by copolymerizing acrylic monomers such as hydroxyalkyl (meth) acrylate.

  As silane coupling agents, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-chloropropylmethoxysilane, vinyl Examples include trichlorosilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β (aminoethyl) -γ-aminopropyltrimethoxysilane, and γ-isocyanatopropyltriethoxysilane, particularly anionic In view of the reactivity with the polymer, epoxy silane, amino silane, and isocyanate silane are preferable.

1-50 mass parts is preferable with respect to 100 mass parts of anionic polymers, and, as for the compounding quantity of a crosslinking agent, 10-20 mass parts is more preferable. When the ratio of the crosslinking agent is 1 part by mass or more with respect to 100 parts by mass of the anionic polymer, a crosslinked structure is easily formed. When the ratio of the crosslinking agent is 50 parts by mass or less with respect to 100 parts by mass of the anionic polymer, the pot life of the coating liquid is improved.
The method of crosslinking the anionic polymer is not limited to the crosslinking agent, and may be a method of forming ionic crosslinking using a titanium or zirconium compound.

In the corrosion prevention treatment layer 14 described above, the corrosion prevention treatment layer 14 by chemical conversion treatment represented by chromate treatment forms an inclined structure with the aluminum foil. Then, the aluminum foil is treated with a chemical conversion treatment agent, and then a chemical conversion treatment layer is formed on the aluminum foil by the action of chromium or a non-chromium compound. However, since the chemical conversion treatment uses an acid as the chemical conversion treatment agent, it involves deterioration of the working environment and corrosion of the coating apparatus.
On the other hand, unlike the chemical conversion treatment typified by the chromate treatment, the coating type corrosion prevention treatment layer 14 described above does not require an inclined structure to be formed on the aluminum foil layer 13. Therefore, the properties of the coating agent are not subject to restrictions such as acidity, alkalinity, and neutrality, and a good working environment can be realized. In addition, the chromate treatment using a chromium compound is preferably the coating-type corrosion prevention treatment layer 14 from the viewpoint that an alternative is required for environmental hygiene.

The corrosion prevention treatment layer 14 may have a laminated structure in which a cationic polymer is further laminated as necessary.
Examples of the cationic polymer include polyethyleneimine, an ionic polymer complex composed of polyethyleneimine and a polymer having a carboxylic acid, a primary amine-grafted acrylic resin obtained by grafting a primary amine to an acrylic main skeleton, polyallylamine or a derivative thereof, An aminophenol resin etc. are mentioned.

Examples of the “polymer having a carboxylic acid” forming an ionic polymer complex include polycarboxylic acid (salt), a copolymer in which a comonomer is introduced into polycarboxylic acid (salt), a polysaccharide having a carboxy group, and the like. It is done. Examples of the polycarboxylic acid (salt) include polyacrylic acid or an ionic salt thereof. Examples of the polysaccharide having a carboxy group include carboxymethyl cellulose or an ionic salt thereof. Examples of the ionic salt include alkali metal salts and alkaline earth metal salts.
The primary amine-grafted acrylic resin is a resin obtained by grafting a primary amine to an acrylic main skeleton. Examples of the acrylic main skeleton include various monomers used in the above-described acrylic polyol, such as poly (meth) acrylic acid. Examples of the primary amine grafted on the acrylic main skeleton include ethyleneimine.
As polyallylamine or derivatives thereof, homopolymers or copolymers of allylamine, allylamine amide sulfate, diallylamine, dimethylallylamine, etc. can be used. Furthermore, these amines can be free amines or acetic acid or hydrochloric acid. Stabilized products can also be used. Further, maleic acid, sulfur dioxide or the like can be used as a copolymer component. Furthermore, it is possible to use a type in which a primary amine is partially methoxylated to impart thermal crosslinkability.
These cationic polymers may be used alone or in combination of two or more.
Among the above, the cationic polymer is preferably at least one selected from the group consisting of polyallylamine and derivatives thereof.

The cationic polymer is preferably used in combination with a crosslinking agent having a functional group capable of reacting with an amine / imine such as a carboxy group or a glycidyl group.
As a crosslinking agent used in combination with a cationic polymer, a polymer having a carboxylic acid that forms an ionic polymer complex with polyethyleneimine can also be used. For example, polycarboxylic acid (salt) such as polyacrylic acid or an ionic salt thereof, And a copolymer having a carboxy group such as carboxymethylcellulose or an ionic salt thereof.

In the present invention, the cationic polymer is also described as one component constituting the corrosion prevention treatment layer 14. The reason for this is that, as a result of intensive studies using various compounds to provide the electrolyte resistance and hydrofluoric acid resistance required for the exterior materials for lithium ion batteries, the cationic polymer itself also has electrolyte resistance and anti-fluorine resistance. This is because the compound was found to be capable of imparting acidity. This factor is presumed to be because the aluminum foil is suppressed from being damaged by capturing fluorine ions with a cationic group (anion catcher). The cationic polymer is also very preferable in terms of improving the adhesion between the corrosion prevention treatment layer 14 and the adhesive resin layer 15.
Moreover, since the cationic polymer is water-soluble like the anionic polymer described above, the water resistance can be improved by forming a crosslinked structure using the crosslinking agent. Thus, since a crosslinked structure can be formed even if a cationic polymer is used, when a rare earth oxide sol is used for forming the corrosion prevention treatment layer 14, instead of an anionic polymer as a protective layer thereof. Cationic polymers may be used.

From the above, examples of the corrosion prevention treatment layer formed by the coating type corrosion prevention treatment include the following treatment layer (α), treatment layer (β), treatment layer (γ) and the like.
Treatment layer (α) A layer containing a rare earth oxide.
Treatment layer (β) A layer containing an anionic polymer and no rare earth oxide.
Treatment layer (γ) A layer containing a cationic polymer and no rare earth oxide.

Examples of the treatment layer (α) include the following treatment layers (α1) to (α10).
(Α1) A layer containing a rare earth element oxide formed using only a rare earth element oxide sol.
(Α2) A mixed layer containing a rare earth element oxide and an anionic polymer.
(Α3) A mixed layer containing a rare earth element oxide and a cationic polymer.
(Α4) A mixed layer containing a rare earth element oxide, an anionic polymer, and a cationic polymer.
(Α5) A multilayer obtained by laminating (compositing) a layer formed of an anionic polymer on the layer of (α1).
(Α6) A multilayer obtained by laminating (compositing) a layer formed of a cationic polymer on the layer of (α1).
(Α7) A multilayer in which a layer formed of a cationic polymer is laminated (multilayered) on the mixed layer of (α2).
(Α8) A multilayer obtained by laminating (multilayering) a layer formed of an anionic polymer on the mixed layer of (α3).
(Α9) A multilayer in which a layer formed of a cationic polymer is laminated (multilayered) on the multilayer of (α5).
(Α10) A multilayer in which a layer formed of an anionic polymer is laminated (multilayered) on the multilayer of (α6).

  The treatment layers (α2) to (α4) need to take into account the stability of the coating liquid, but the coating agent in which the rare earth element oxide sol and at least one of the cationic polymer and the anionic polymer are preliminarily made into one liquid. (Processing agent).

Among the above, the treatment layer (α) is preferable as the corrosion prevention treatment layer 14, and the treatment layers (α2) to (α10) are highly effective in suppressing the corrosion of the aluminum foil layer 13 by the electrolytic solution. Is more preferable.
Further, the cationic polymer has good adhesiveness with the modified polyolefin resin mentioned in the adhesive resin layer 15 described later. Therefore, when a modified polyolefin resin is used for the adhesive resin layer 15, the treatment layers (α3), (α4), (α6), (α7), and (α9) are more preferable.

However, the corrosion prevention treatment layer 14 is not limited to the above-described layer. For example, it may be formed using an agent in which phosphoric acid and a chromium compound are blended in a resin binder (aminophenol resin or the like), such as a coating chromate that is a known technique. If this processing agent is used, it becomes possible to form a layer having both a corrosion prevention function and adhesion.
Moreover, in order to improve adhesiveness with respect to the chemical conversion treatment layer (a layer formed by degreasing treatment, hydrothermal modification treatment, anodizing treatment, chemical conversion treatment, or a combination of these treatments), the cationic property described above is used. It is also possible to perform a complex treatment using a polymer or an anionic polymer, or to laminate a cationic polymer or an anionic polymer as a multilayer structure for a combination of these treatments.

Mass per unit area of the corrosion prevention treatment layer 14 is preferably in the range of 0.005~0.200g / ^{m 2,} the range of 0.010~0.100g / ^{m 2} is more preferable. If it is 0.005 g / m ² or more, the aluminum foil layer 13 is easily imparted with a corrosion prevention function. Further, even if the mass per unit area exceeds 0.200 g / m ² , the corrosion prevention function is saturated and does not change much. On the other hand, when the rare earth oxide sol is used, if the coating film is thick, curing due to heat at the time of drying becomes insufficient, and there is a possibility that the cohesive force is lowered.
In addition, although it described with the mass per unit area in the said content, if specific gravity is known, it is also possible to convert thickness from there.

(Adhesive resin layer)
The adhesive resin layer 15 is a layer for bonding the aluminum foil layer 13 on which the corrosion prevention treatment layer 14 is formed and the sealant layer 16.
As the heat-adhesive resin for forming the adhesive resin layer 15, for example, an unsaturated carboxylic acid or an acid anhydride thereof, or an ester of an unsaturated carboxylic acid or an acid anhydride thereof is present in a polyolefin resin. Examples thereof include modified polyolefin resins obtained by graft modification below. Hereinafter, the unsaturated carboxylic acid or its acid anhydride and the ester of the unsaturated carboxylic acid or its acid anhydride are sometimes referred to as a graft compound.
The modified polyolefin resin imparts adhesiveness by utilizing the reactivity between the functional group of the grafted graft compound and various metals or polymers containing functional groups.

Examples of the polyolefin resin include low density polyethylene, medium density polyethylene, high density polyethylene, ethylene-α olefin copolymer, homopolypropylene, block polypropylene, random polypropylene, propylene-α olefin copolymer, and the like.
As unsaturated carboxylic acid, acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, tetrahydrophthalic acid, bicyclo [2,2,1] hept-2-ene-5,6-dicarboxylic acid, etc. Is mentioned.
Examples of unsaturated carboxylic acid anhydrides include maleic anhydride, itaconic anhydride, citraconic anhydride, tetrahydrophthalic anhydride, bicyclo [2,2,1] hept-2-ene-5,6-dicarboxylic anhydride Etc.
Examples of the unsaturated carboxylic acid or its anhydride ester include methyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dimethyl maleate, monomethyl maleate, diethyl fumarate, dimethyl itaconate, diethyl citraconic acid, Examples include dimethyl tetrahydrophthalic anhydride, dimethyl bicyclo [2,2,1] hept-2-ene-5,6-dicarboxylate, and the like.

The ratio of the graft compound in the modified polyolefin resin is preferably 0.2 to 100 parts by mass with respect to 100 parts by mass of the polyolefin resin.
The temperature condition for the graft reaction is preferably 50 to 250 ° C, more preferably 60 to 200 ° C.
Although the reaction time depends on the production method, in the case of a melt graft reaction by a twin screw extruder, the residence time of the extruder is preferable. Specifically, 2 to 30 minutes is preferable, and 5 to 10 minutes is more preferable.
The grafting reaction can be carried out under both normal pressure and pressurized conditions.
Examples of the radical initiator include organic peroxides. Examples of the organic peroxide include alkyl peroxides, aryl peroxides, acyl peroxides, ketone peroxides, peroxyketals, peroxycarbonates, peroxyesters, hydroperoxides, and the like. These organic peroxides can be appropriately selected depending on temperature conditions and reaction time. In the case of the melt graft reaction by the above-described twin-screw extruder, alkyl peroxide, peroxyketal, and peroxyester are preferable, di-t-butyl peroxide, 2,5-dimethyl-2,5-di-t-butyl. Peroxy-hexyne-3 and dicumyl peroxide are more preferred.

  As the modified polyolefin resin, a modified polyolefin resin modified with maleic anhydride is preferable. Examples of such modified polyolefin resins include Mitsui Chemicals Admer, Mitsubishi Chemical Modic, Nippon Polyethylene Adtex, and the like.

In the adhesive resin layer 15, a thermoplastic elastomer may be blended with the modified polyolefin resin. By blending the thermoplastic elastomer, the residual stress generated when the modified polyolefin resin is laminated is released, and the adhesiveness is further enhanced.
As the thermoplastic elastomer, Mitsui Chemicals Tuffmer, Mitsubishi Chemical Zelas, Montell Catalloy, Mitsui Chemicals Notio, and styrene elastomers are preferred. The styrene elastomer is more preferably a hydrogenated styrene elastomer (AK Elastomer Tuftec, Kuraray Septon / Hibler, JSR Dynalon, Sumitomo Chemical Espolex, etc.).

  The adhesive resin layer 15 may contain various additives such as a flame retardant, slip agent, anti-blocking agent, antioxidant, light stabilizer, and tackifier.

  The thickness of the adhesive resin layer 15 is preferably 3 to 50 μm, and more preferably 10 to 40 μm. If the thickness of the adhesive resin layer 15 is not less than the lower limit value, excellent adhesiveness is easily obtained. If the thickness of the adhesive resin layer 15 is equal to or less than the upper limit value, the amount of moisture that permeates from the side end face of the exterior material 1 is reduced.

(Sealant layer)
The sealant layer 16 is a layer that imparts sealing properties to the exterior material 1 by heat sealing.
Examples of the material constituting the sealant layer 16 include polyolefins such as low density polyethylene, medium density polyethylene, high density polyethylene, ethylene-α olefin copolymer, homo, block, or random polypropylene, propylene-α olefin copolymer. Examples thereof include a resin, an ethylene-vinyl acetate copolymer, an ethylene- (meth) acrylic acid copolymer, an esterified product thereof, and an ionic cross-linked product.
The sealant layer 16 may be a single layer made of any one or a blend of two or more of the above-described resins, and may have a multilayer structure according to other required performance required for the sealant. As the sealant layer 16 having a multilayer structure, for example, a sealant layer in which a resin having gas barrier properties such as an ethylene-vinyl acetate copolymer portion or a completely saponified product, a polyvinyl acetate copolymer portion or a completely saponified product is interposed. Etc.

(Method for manufacturing exterior material 1)
The packaging material 1 can be manufactured, for example, by a manufacturing method having the following steps (1) to (4).
(1) A step of forming a corrosion prevention treatment layer 14 on one surface of the aluminum foil layer 13 by performing a corrosion prevention treatment.
(2) The process of bonding the base material layer 11 through the 1st adhesive bond layer 12 on the opposite side to the side in which the corrosion prevention process layer 14 was formed of the aluminum foil layer 13. FIG.
(3) A step of bonding the sealant layer 16 to the side of the aluminum foil layer 13 on which the corrosion prevention treatment layer 14 is formed via the adhesive resin layer 15.
(4) The process of heat-processing the laminated body which consists of the base material layer 11, the 1st adhesive bond layer 12, the aluminum foil layer 13, the corrosion prevention process layer 14, the adhesive resin layer 15, and a sealant layer.

Step (1):
The corrosion prevention treatment layer 14 can be formed by performing a corrosion prevention treatment on one surface of the aluminum foil layer 13 (the surface opposite to the side on which the base material layer 11 is bonded).
The corrosion prevention treatment is as described above. Specific examples include a degreasing treatment, a hydrothermal alteration treatment, an anodizing treatment, a chemical conversion treatment, and a coating type corrosion prevention treatment in which a coating agent having corrosion prevention performance is applied.
Examples of the degreasing method include annealing, spraying, and dipping.
Examples of the hydrothermal modification treatment method and the anodizing treatment method include an immersion method.
As the chemical conversion treatment method, an immersion method, a spray method, a coating method, or the like can be selected according to the type of chemical conversion treatment.
Various coating methods such as gravure coating, reverse coating, roll coating, and bar coating can be employed as a coating method for a coating agent having corrosion prevention performance.
The coating amount of the coating agent having corrosion prevention performance is preferably within a range satisfying the mass per unit area of the corrosion prevention treatment layer 14 described above. Moreover, when drying cure is required, it can implement in the range of 60-300 degreeC as base material temperature according to the drying conditions of the corrosion prevention process layer 14 to be used.

Step (2):
As a method of bonding the base material layer 11 through the first adhesive layer 12 to the side of the aluminum foil layer 13 opposite to the side on which the corrosion prevention treatment layer 14 is formed, dry lamination, non-solvent lamination, wet lamination It is possible to employ known methods such as. Among these, it is preferable to use a dry lamination method.
As the adhesive forming the first adhesive layer 12, the polyurethane adhesive described in the first adhesive layer 12 is preferable.
The dry coating amount of the adhesive is preferably 1 to 10 g / m ^{2 and} more preferably 3 to 7 g / m ² .
After bonding, an aging treatment (curing) may be performed in the range of room temperature to 100 ° C. to promote adhesion.

Step (3):
As a method of attaching the sealant layer 16 to the corrosion prevention treatment layer 14 side of the aluminum foil layer 13 via the adhesive resin layer 15, a known method such as sand lamination or coextrusion can be employed. For example, by performing sand lamination using an extrusion laminating machine, the base layer 11 / first adhesive layer 12 / aluminum foil layer 13 / corrosion prevention treatment layer 14 / adhesive resin layer 15 / sealant layer 16 are obtained. A layer structure can be formed. Alternatively, the adhesive resin layer 15 and the sealant layer 16 may be formed by coextrusion.
The extrusion temperature of the adhesive resin layer 15 is preferably 200 to 340 ° C.

Step (4):
In the laminate (base layer 11 / first adhesive layer 12 / aluminum foil layer 13 / corrosion prevention treatment layer 14 / adhesive resin layer 15 / sealant layer 16) formed by the steps (1) to (3), By performing the heat treatment, the adhesion between the layers can be improved, and the electrolytic solution resistance and hydrofluoric acid resistance can be improved.
As a heat treatment method, a method of storing the laminate in an aging furnace, a method of closely attaching a thermocompression roll to the laminate, a method of holding the laminate on a thermal drum, and passing the laminate through an annealing furnace Methods and the like.
The heat treatment temperature is preferably set so that the maximum temperature reached by the laminate is 40 ° C. to 220 ° C., more preferably 80 ° C. to 200 ° C. Although the treatment time depends on the treatment temperature, it is preferable to perform treatment for a longer time as the temperature is lower and a shorter time as the temperature is higher.

The manufacturing method of the exterior material 1 is not limited to said manufacturing method.
For example, in the step (1), a corrosion prevention treatment layer may be provided on both surfaces of the aluminum foil layer.
Moreover, you may perform a process (2) after performing a process (3).
Moreover, the method which does not perform a process (4) may be sufficient.
Before the step (2), on the surface of the film constituting the base material layer 11 opposite to the side to be bonded to the aluminum foil layer 13 (the surface to be the surface 1a on the outermost layer side of the exterior material 1), You may perform the process of giving surface treatments, such as application | coating of a surface modifier, and surface modification treatment, and obtaining the base material layer 11. FIG. In step (2), instead of the substrate layer 11, a film having a contact angle after 5 seconds of less than 10 ° or more than 30 ° is used, and the step (2), step (3) or step (4) Thereafter, the surface of the obtained laminate on the film side may be subjected to a surface treatment such as application of the surface modifier, surface modification treatment, etc., and the film is used as the base material layer 11. Good.
The surface modifier is preferably applied by dissolving and dispersing in a solvent. The coating can be performed by a known coating technique such as spray coating, die coating, spin coating, dip coating, roll coating, bar coating, screen printing, or gravure coating. The coating amount of the surface modifier is set according to the target contact angle after 5 seconds. Surface modification treatment such as corona treatment and plasma treatment can be performed by a known method.
After step (4) or after step (3), if necessary, a step of applying a slip material and / or an antiblocking material to the outermost layer and / or innermost layer of the obtained laminate may be performed. Good. By applying the slip material and / or the anti-blocking material, the coefficient of static friction can be lowered, and the molding performance is improved. The slip agent and / or anti-blocking agent is preferably dissolved and dispersed in a solvent. Application | coating can be implemented with a well-known coating method.

[Second Embodiment]
Next, a second embodiment of the exterior material of the present invention will be described. In the embodiment described below, the same reference numerals are given to the components corresponding to the first embodiment, and detailed description thereof will be omitted.
FIG. 2 is a schematic cross-sectional view of the exterior material 2 according to the second embodiment of the present invention.
The exterior material 2 is a laminate in which the first adhesive layer 12, the aluminum foil layer 13, the second adhesive layer 25, and the sealant layer 16 are laminated in this order on one surface of the base material layer 11. The corrosion prevention treatment layer 14 is provided on the surface of the aluminum foil layer 13 on the sealant layer 16 side.
The exterior material 2 is printed on the surface of the base material layer 11 opposite to the first adhesive layer 12 side, that is, the surface 2 a of the exterior material 2 on the base material layer 11 side. When a droplet of an ink solvent contained in the ink used for printing is deposited on the surface 2a, the contact angle after 5 seconds is 10 ° to 30 °, and the contact angle changes with time (5 seconds). Is 6 ° or less.
The packaging material 2 is the same as the packaging material 1 except that it has a second adhesive layer 25 instead of the adhesive resin layer 15.

(Second adhesive layer)
Similar to the adhesive resin layer 15, the second adhesive layer 25 is a layer that bonds the aluminum foil layer 13 on which the corrosion prevention treatment layer 14 is formed and the sealant layer 16.
While the bonding of the aluminum foil layer 13 and the sealant layer 16 with the adhesive resin layer 15 is mainly suitable for thermal lamination, the bonding with the second adhesive layer 25 can be easily applied to dry lamination. .

Examples of the adhesive that forms the second adhesive layer 25 include the same adhesives as those mentioned in the first adhesive layer 12. For example, the polyurethane adhesive containing the main ingredient which consists of polyols, such as polyester polyol, polyether polyol, acrylic polyol, carbonate polyol, and the hardening | curing agent which consists of a bifunctional or more than isocyanate compound is mentioned. Further, as the main agent, not only the above-mentioned polyol type, but also a solution in which acid-modified polyolefin is dissolved or dispersed in a solvent can be used. As the curing agent in this case, the above-described isocyanate compound, carbodiimide compound, or epoxy compound can be used.
The composition of the adhesive forming the second adhesive layer 25 (for example, the types of the main agent and polyisocyanate curing agent in the polyurethane adhesive and the blending amount thereof) is the adhesive forming the first adhesive layer 12. May be the same or different.

However, since the adhesive used for the second adhesive layer 25 is an adhesive that bonds the surface on the side filled with the electrolytic solution, it is necessary to pay attention to swelling with the electrolytic solution and hydrolysis with hydrofluoric acid. is there. Therefore, it is preferable to use an adhesive using a main agent having a skeleton that is difficult to be hydrolyzed, an adhesive having an improved crosslinking density, and the like.
For example, as a technique for improving the crosslinking density of a polyester polyol adhesive composition, dimer fatty acid or its ester or its hydrogenated product, or dimer fatty acid or its ester or its hydrogenated reducing glycol is used as the polybasic acid. Is mentioned. Dimer fatty acid is a dimerization of various unsaturated fatty acids, and its structure includes acyclic, monocyclic, polycyclic, and aromatic ring types. Polyester used in this adhesive The polybasic acid that is a raw material of the polyol is not particularly limited. There are no particular restrictions on the unsaturated fatty acid that is the starting material for the dimer fatty acid, and there are monounsaturated fatty acids, diunsaturated fatty acids, triunsaturated fatty acids, tetraunsaturated fatty acids, pentaunsaturated fatty acids, hexaunsaturated fatty acids It can be used as appropriate. Examples of monounsaturated fatty acids include crotonic acid, myristoleic acid, palmitoleic acid, oleic acid, elaidic acid, vaccenic acid, gadoleic acid, eicosenoic acid, erucic acid, and nervonic acid. Examples of diunsaturated fatty acids include linoleic acid, eicosadienoic acid, and docosadienoic acid. Examples of the triunsaturated fatty acid include linolenic acid, vinolenic acid, eleostearic acid, mead acid, dihomo-γ-linolenic acid, and eicosatrienoic acid. Examples of tetraunsaturated fatty acids include stearidonic acid, arachidonic acid, eicosatetraenoic acid, and adrenic acid. Examples of the pentaunsaturated fatty acid include boseopentaenoic acid, eicosaventaenoic acid, ozbond acid, sardine acid, and tetracosaventaenoic acid. Examples of the hexaunsaturated fatty acid include docosahexaenoic acid and nisic acid. The combination of unsaturated fatty acids when dimerizing unsaturated fatty acids may be any combination. This bulky hydrophobic unit of dimer fatty acid improves the crosslink density as an adhesive.
A dibasic acid such as that used in ordinary polyester polyols may be introduced using the dimer fatty acid as an essential component. Examples of the dibasic acid include aliphatics such as succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and brassic acid, and aromatics such as isophthalic acid, terephthalic acid, and naphthalenedicarboxylic acid. It is possible to select from a family.

  As the adhesive forming the second adhesive layer 25, a polyurethane-based adhesive containing a polyester polyol as a main agent is preferable. Preferred examples of the polyester polyol include aliphatic glycols such as ethylene glycol, propylene glycol, butanediol, neopentyl glycol, methylpentanediol, hexanediol, heptanediol, octanediol, nonanediol, decanediol, and dodecanediol, cyclohexanediol. And components obtained by using one or more of alicyclic systems such as hydrogenated xylylene glycol and aromatic diols such as xylylene glycol. Moreover, the polyester urethane polyol which extended | stretched the hydroxyl group of the both terminals of this polyester polyol using the isocyanate compound single-piece | unit or the adduct body, burette body, or isocyanurate body which consists of at least 1 type of isocyanate compound etc. are mentioned. Examples of the isocyanate compound include 2,4- or 2,6-tolylene diisocyanate, xylylene diisocyanate, 4,4′-diphenylmethane diisocyanate, methylene diisocyanate, isopropylene diisocyanate, lysine diisocyanate, 2,2,4- or 2, Examples include 4,4-trimethylhexamethylene diisocyanate, 1,6-hexamethylene diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, and isopropylidene dicyclohexyl-4,4′-diisocyanate. In addition, the isocyanate component described later can also be used as a chain extender for polyester polyol.

As the curing agent for the main agent, it is possible to use the same type of isocyanate compound used as the chain extender of the polyester polyol, and although it is repeated, 2,4- or 2,6-tolylene diisocyanate, xylylene Range isocyanate, 4,4'-diphenylmethane diisocyanate, methylene diisocyanate, isopropylene diisocyanate, lysine diisocyanate, 2,2,4- or 2,4,4-trimethylhexamethylene diisocyanate, 1,6-hexamethylene diisocyanate, methylcyclohexane diisocyanate , Isophorone diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, isopropylidene dicyclohexyl-4,4′-diisocyanate, etc. Single bets compound or adduct of at least one isocyanate compound selected from the isocyanate compound, biuret body, isocyanurate products thereof. In addition, for the purpose of improving the resistance of the electrolyte (especially solubility and swelling in the electrolyte), polyisocyanate alone or a mixture selected from crude tolylene diisocyanate, crude (or polymeric) diphenylmethane diisocyanate, or adducts thereof. It is effective to use. The use of these curing agents leads to improvement in solubility and swelling property due to improvement in the crosslinking density of the adhesive coating film, and the urethane group concentration increases, so that the corrosion prevention treatment layer 14 and the sealant layer 16 Improvement in adhesion is also expected. The use of the above-mentioned crude tolylene diisocyanate or crude (or polymeric) diphenylmethane diisocyanate as a chain extender of the above-described polyester polyol can be said to be a suitable material for use as an exterior material for a lithium ion battery.
As a compounding quantity of a hardening | curing agent, 1-100 mass parts is preferable with respect to 100 mass parts of main agents, and 5-50 mass parts is more preferable. If the amount is less than 1 part by mass, the performance may not be exhibited in terms of adhesion and electrolyte resistance. If the amount is more than 100 parts by mass, an excess of isocyanate groups will be present, which may affect the adhesive film quality due to the residual unreacted substances and the hardness.

It is also possible to mix a carbodiimide compound, an oxazoline compound, an epoxy compound, a phosphorus compound, a silane coupling agent, and the like with the polyurethane adhesive for promoting adhesion. Specific examples of these compounds are as described above.
In addition, various additives and stabilizers may be blended depending on the performance required for the adhesive.

  1-10 micrometers is preferable and, as for the thickness of the 2nd adhesive bond layer 25, 3-5 micrometers is more preferable. When it is 1 μm or more, the electrolytic solution resistance and the laminate strength are improved, and when it is 10 μm or less, the amount of moisture transmitted from the end face of the laminate material is improved.

(Method for manufacturing exterior material 2)
The packaging material 2 can be manufactured, for example, by a manufacturing method having the following steps (1 ′) to (4 ′).
(1 ′) A step of forming a corrosion prevention treatment layer 14 on one surface of the aluminum foil layer 13 by performing a corrosion prevention treatment.
(2 ′) A step of bonding the base material layer 11 to the side of the aluminum foil layer 13 opposite to the side on which the corrosion prevention treatment layer 14 is formed via the first adhesive layer 12.
(3 ′) A step of bonding the sealant layer 16 to the corrosion prevention treatment layer 14 side of the aluminum foil layer 13 via the second adhesive layer 25.
(4 ') The process of heat-processing the laminated body which consists of the base material layer 11, the 1st adhesive bond layer 12, the base treatment layer 31, the aluminum foil layer 13, the corrosion prevention process layer 14, the adhesive resin layer 15, and a sealant layer.

  The steps (1 ′), (2 ′), and (4 ′) can be performed in the same manner as the steps (1), (2), and (4) in the manufacturing method described as the method for manufacturing the exterior material 1. .

Step (3 ′):
As a method of bonding the sealant layer 16 to the corrosion prevention treatment layer 14 side of the aluminum foil layer 13 via the second adhesive layer 25, the corrosion prevention treatment of the aluminum foil layer 13 described in the step (2). A method similar to the method of bonding the base material layer 11 to the side opposite to the side where the layer 14 is formed via the first adhesive layer 12 can be employed.

The manufacturing method of the exterior material 2 is not limited to said manufacturing method.
For example, in the step (1 ′), a corrosion prevention treatment layer may be provided on both surfaces of the aluminum foil layer.
Moreover, you may perform a process (2 ') after performing a process (3').
Moreover, the method of not performing a process (4 ') may be sufficient.
Before the step (2 ′), on the surface of the film constituting the base material layer 11 on the side opposite to the side to be bonded to the aluminum foil layer 13 (the surface to be the surface 2a on the outermost layer side of the exterior material 2), You may perform the process of giving surface treatments, such as application | coating of the said surface modifier, and surface modification treatment, and obtaining the base material layer 11. FIG. In step (2 ′), instead of the base material layer 11, a film having a contact angle of less than 10 ° or more than 30 ° after 5 seconds is used, and the step (2 ′), step (3 ′) or step ( 4 ′), the surface of the obtained laminate on the film side is subjected to surface treatment such as application of the surface modifier, surface modification treatment, etc., and the film is used as the substrate layer 11 May be performed.
After the step (4 ′) or after the step (3 ′), a step of applying a slip material and / or an antiblocking material to the outermost layer and / or the innermost layer of the obtained laminate is performed as necessary. May be.

[Third Embodiment]
Next, a third embodiment of the exterior material of the present invention will be described.
FIG. 3 is a schematic cross-sectional view of the exterior material 3 according to the third embodiment of the present invention.
The exterior material 3 is a laminate in which the first adhesive layer 12, the aluminum foil layer 13, the second adhesive layer 25, and the sealant layer 16 are laminated in this order on one surface of the base material layer 11. The surface treatment layer 31 is provided on the surface of the aluminum foil layer 13 on the base material layer 11 side, and the corrosion prevention treatment layer 14 is provided on the surface on the sealant layer 16 side.
The exterior material 3 is printed on the surface of the base material layer 11 opposite to the first adhesive layer 12 side, that is, the surface 3 a of the exterior material 1 on the base material layer 11 side. When a droplet of an ink solvent contained in the ink used for printing is deposited on the surface 3a, the contact angle after 5 seconds is 10 ° to 30 °, and the contact angle changes with time (5 seconds). Is 6 ° or less.
The packaging material 3 is the same as the packaging material 2 except that the packaging material 3 has a base treatment layer 31.

(Undercoat layer)
The base treatment layer 31 plays a role of further improving the adhesion between the aluminum foil layer 13 and the base material layer 11 by improving the adhesion between the aluminum foil layer 13 and the first adhesive layer 12. By further increasing the adhesion, the formability of the exterior material is improved.
Examples of the base treatment layer 31 include a layer containing the following component (A).
(A) A crosslinked resin formed from a resin (A1) having two or more nitrogen-containing functional groups and a resin (A2) having a reactive functional group that reacts with the nitrogen-containing functional groups.

A component (A) mainly contributes to the improvement of heat-resistant adhesiveness. When the ground treatment layer 31 is provided by various processes, the nitrogen-containing functional group of the resin (A1) and the reactive functional group of the resin (A2) react to form a cross-linked site containing a nitrogen atom. By forming the cross-linked site, the adhesion between the base material layer 11 and the aluminum foil layer 13 is improved. In addition, the base treatment layer 31 containing a cross-linked site containing nitrogen atoms gives good heat-resistant adhesion to the aluminum foil layer 13.
As a nitrogen-containing functional group which resin (A1) has, an oxazoline group, an amino group, etc. are mentioned, for example. The reactive functional group which resin (A2) has can be suitably selected according to the nitrogen-containing functional group which resin (A1) has.

Examples of the combination of the resin (A1) and the resin (A2) in the component (A) include the following (A-1) and (A-2).
(A-1): Resin (A1) is an oxazoline group-containing resin containing two or more oxazoline groups (hereinafter also referred to as resin (A1-1)), and resin (A2) is poly (meth). At least one acrylic resin selected from the group consisting of acrylic acid, copolymers of (meth) acrylic acid and other polymerizable monomers, and ionic neutralized products thereof (hereinafter referred to as resin (A2-1)) Say.)
(A-2): Resin (A1) is an amino group-containing resin containing two or more amino groups (hereinafter also referred to as resin (A1-2)), and resin (A2) is a glycidyl group-containing compound. (Hereinafter also referred to as resin (A2-2)).

The resin (A1-1) is not particularly limited as long as it is a resin having at least two oxazoline groups in one molecule.
Examples of the resin (A1-1) include an oxazoline group-containing resin whose main chain is an acrylic skeleton and containing two or more oxazoline groups, and an oxazoline group-containing resin whose main chain is a styrene / acryl skeleton and containing two or more oxazoline groups. Styrene / acrylic resins such as styrene resins having a styrene skeleton with two or more oxazoline groups, acrylonitrile / styrene resins having two or more oxazoline groups with an acrylonitrile / styrene skeleton. It is done.

Resin (A1-1) includes, for example, an oxazoline group-containing monomer such as isopropenyl oxazoline and other polymerizable monomers copolymerizable with the oxazoline group-containing monomer, such as styrene and acrylonitrile. It is obtained by polymerizing.
The ratio of the oxazoline group-containing monomer that forms the resin (A1-1) is preferably 0.5 mmol / g to 50 mmol / g, and more preferably 1 mmol to 10 mmol / l. When the oxazoline group-containing monomer is less than 0.5 mmol / g, it is difficult to obtain sufficient adhesion. The oxazoline group-containing monomer may exceed 50 mmol / g, but its performance is saturated.

Resin (A2-1) is at least one acrylic selected from the group consisting of poly (meth) acrylic acid, copolymers of (meth) acrylic acid and other polymerizable monomers, and ionic neutralized products thereof. Resin.
Resin (A2-1) has a carboxy group derived from (meth) acrylic acid, and this carboxy group reacts with the oxazoline group of component (A1) to form an amide ester moiety.
The acrylic resin of the resin (A2-1) is preferably a resin mainly composed of (meth) acrylic acid or an ion salt (ammonium salt, sodium salt, etc.) of (meth) acrylic acid.
Other polymerizable monomers copolymerized with (meth) acrylic acid include, for example, alkyl (meth) acrylate monomers (alkyl groups include methyl, ethyl, n-propyl, i-propyl, n- Butyl group, i-butyl group, t-butyl group, 2-ethylhexyl group, cyclohexyl group and the like); hydroxyl group-containing (meth) acrylic monomers such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate; (Meth) acrylamide, N-alkyl (meth) acrylamide, N, N-dialkyl (meth) acrylamide (As the alkyl group, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i -Butyl group, t-butyl group, 2-ethylhexyl group, cyclohexyl group, etc.), N-alkoxy ( T) acrylamide, N, N-dialkoxy (meth) acrylamide (alkoxy groups include methoxy group, ethoxy group, butoxy group, isobutoxy group, etc.), N-methylol (meth) acrylamide, N-phenyl (meth) acrylamide, etc. And amide group-containing monomers. Other polymerizable monomers include styrene, α-methyl styrene, vinyl methyl ether, vinyl ethyl ether, maleic acid, alkyl maleic acid monoester, fumaric acid, alkyl fumaric acid monoester, itaconic acid, alkyl itaconic acid monoester. , (Meth) acrylonitrile, vinylidene chloride, ethylene, propylene, vinyl chloride, vinyl acetate, butadiene, or the like may be used.
The resin (A2-1) may be an ion neutralized product. Examples of the ion neutralized product include ion salts such as ammonium salt or sodium salt of the resin.

The amino group-containing resin of the resin (A1-2) is not particularly limited as long as it is a resin having at least two amino groups in one molecule, and examples thereof include polyallylamine and aminophenol resins.
The glycidyl group-containing compound of the resin (A2-2) is preferably a resin having at least two glycidyl groups in one molecule, such as polyglycerol polyglycidyl ether.

As a component (A), the combination of (A-1) is preferable among the above. The base treatment layer 31 has an amide ester site formed by a reaction between the oxazoline group of the resin (A1-1) and the carboxy group of the resin (A2-1). The adhesion of the aluminum foil layer 13 is improved.
Moreover, it is preferable to utilize that the aluminum foil which comprises the aluminum foil layer 13 is an amphoteric compound in the point of aiming at the further improvement of adhesiveness. That is, not only the effect by the amide ester moiety, but also the carboxy group of the resin (A2-2) acts as an “acidic group” to impart an acid / base interaction, thereby further improving the adhesion. For this purpose, it is preferable to mix so that the carboxy group contained in the resin (A2-2) is excessive from the equivalent amount to the oxazoline group contained in the resin (A1-1).
The ratio of the oxazoline group of the resin (A1-1) to the carboxy group of the resin (A2-1) is mainly determined by the “oxazoline value” of the oxazoline group contained in the resin (A1-1) and the resin (A2-1). It can be determined using the “acid number” due to the carboxy group involved.

  The mass ratio between the resin (A1-1) and the resin (A1-2) varies depending on the copolymerization component of each component and its molar ratio (or mass ratio), and is not particularly limited, but (A1-1) / (A1 -2) = 1/99 to 99/1 is preferable, and 1/99 to 45/55 is more preferable. If the ratio of the resin (A1-1) to the total amount of the resin (A1-1) and the resin (A1-2) is 1% by mass or more, sufficient crosslinking density is easily obtained, and the amount of the amide ester moiety is also Increased heat resistance and adhesion are improved. In addition, the smaller the ratio of the resin (A1-1) to the total amount of the resin (A1-1) and the resin (A1-2), the more easily the effect of the carboxylic acid described above can be obtained. The carboxy group that has not reacted with the oxazoline group facilitates improving the adhesion.

The base treatment layer 31 may further contain the following component (B) in addition to the component (A).
(B) Rare earth element oxide.
Examples of the rare earth element oxide of component (B) include cerium oxide, yttrium oxide, neodymium oxide, and lanthanum oxide. Of these, cerium oxide is preferred.
The component (B) is usually in the form of fine particles (for example, particles having an average particle size of 100 nm or less), and is used for forming the base treatment layer 31 in the state of a rare earth element oxide sol. The rare earth element oxide sol is obtained by dispersing rare earth element oxide fine particles in a liquid dispersion medium.
As the liquid dispersion medium of the rare earth element oxide sol, various solvents such as water, alcohol solvents, hydrocarbon solvents, ketone solvents, ester solvents, ether solvents and the like can be used. Of these, water is preferred.
The component (B) contained in the base treatment layer 31 may be one type or two or more types.

When the component (B) is included, the base treatment layer 31 preferably further contains the following component (C).
(C) Phosphoric acid or phosphate.
Component (C) is blended as a dispersion stabilizer for stabilizing the dispersion of component (B) in the rare earth element oxide sol, and in particular, it is better to use component (C) as a surface treatment agent for the rare earth oxide. preferable. In addition, since the base treatment layer 31 contains the component (C), not only the dispersion and stabilization of the component (B), but also an aluminum foil that uses the chelating ability of phosphoric acid in the application of an exterior material for a lithium ion battery. Improvement of adhesion with the layer 13, provision of electrolyte resistance by capturing (passivation formation) of metal ions eluted under the influence of hydrofluoric acid, and the dehydration condensation of phosphoric acid is likely to occur even at low temperatures. Effects such as improvement of cohesive force can be obtained.

Examples of the component (C) include orthophosphoric acid, pyrophosphoric acid, metaphosphoric acid, alkali metal salts and ammonium salts thereof.
As the component (C), condensed phosphoric acid such as trimetaphosphoric acid, tetrametaphosphoric acid, hexametaphosphoric acid and ultrametaphosphoric acid, or alkali metal salts and ammonium salts thereof are preferable for the functional expression as a lithium ion battery exterior material. In particular, considering the dry film-forming properties (drying capacity, heat quantity) when forming a layer containing rare earth oxides by various coating methods using a coating composition containing rare earth element oxide sol, the reactivity at low temperature In view of excellent dehydration condensation properties at low temperatures, sodium salts are preferred. As the phosphate, a water-soluble salt is preferable.

The component (C) contained in the base treatment layer 31 may be one type or two or more types.
In the ground treatment layer 31, the content of the component (C) is preferably 1 part by mass or more and more preferably 5 parts by mass or more with respect to 100 parts by mass of the component (B). When the content is 1 part by mass or more, effects such as dispersion and stabilization of the component (B) are sufficiently obtained, and it is easy to satisfy the function as an exterior material for a lithium ion battery. The compounding upper limit of the component (C) may be in a range not accompanied by the functional deterioration of the component (B), and is preferably 100 parts by mass or less, more preferably 50 parts by mass or less, relative to 100 parts by mass of the component (B). 20 parts by mass or less is more preferable.

  In the ground treatment layer 31, the total amount of the component (B) and the component (C) with respect to 100 parts by mass of the component (A) is preferably 200 to 12000 parts by mass, more preferably 300 to 10000 parts by mass, and 500 to 10000 parts by mass. Part is more preferable, and 1000 to 8000 parts by mass is particularly preferable. When the total amount of the component (B) and the component (C) is 200 to 12000 parts by mass with respect to 100 parts by mass of the component (A), particularly the adhesion between the base material layer 11 and the aluminum foil layer 13, Adhesiveness in the electrolyte atmosphere is improved.

In order to further improve the adhesion, the base treatment layer 31 preferably further contains the following component (E) in addition to the component (A). The component (E) plays a role of improving adhesion to the aluminum foil layer 13 when the base treatment layer 31 is provided by various processes.
(E) Organosilane represented by the following formula (1), hydrolyzate of the organosilane, and derivatives thereof (hereinafter referred to as “component (E1)”), and represented by the following formula (2) At least one compound selected from the group consisting of metal alkoxides, hydrolysates of the metal alkoxides, and derivatives thereof (hereinafter referred to as “component (E2)”).
R ¹ —Si (OR ² ) ₃ (1)
M (OR ³ ) _n (2)
(In the formula, R ¹ is an organic group including an alkyl group, a (meth) acryloyloxy group, a vinyl group, an amino group, an epoxy group or an isocyanate group, R ² is an alkyl group, and M is a metal ion. Yes, R ³ is an alkyl group, and n is the same number as the valence of the metal ion.)

Examples of R ¹ in the component (E1) include an alkyl group, a (meth) acryloyloxyalkyl group, a vinyl group, an aminoalkyl group, a glycidoxyalkyl group, and an isocyanate alkyl group.
Examples of the component (E1) include ethyltrimethoxysilane, (meth) acryloxypropyltrimethoxysilane, vinyltrimethoxysilane, glycidoxypropyltrimethoxysilane, aminopropyltrimethoxysilane, hydrolysates thereof, Examples include condensates (dimers, trimers, etc.). Of these, glycidoxytrimethoxysilane and epoxycyclohexylethyltrimethoxysilane containing an epoxy group are particularly preferable.

Examples of M in the component (E2) include Si, Al, Ti, Zr and the like.
Examples of the component (E2) include tetraethoxysilane, tripropoxyaluminum, etc., hydrolysates thereof, condensates thereof, and the like.
As a method for obtaining a hydrolyzate or a condensate thereof in component (E1) and component (E2), a known method such as a method in which acid or alkali is directly added to the organosilane or metal alkoxide, etc. Can be adopted. Moreover, you may add the reaction catalyst which accelerates | stimulates reaction, such as a tin compound, as needed.

The component (E) contained in the base treatment layer 31 may be one type or two or more types.
0.1-100 mass parts is preferable with respect to 100 mass parts of components (A), and, as for content of the component (E) in the base treatment layer 31, 0.3-50 mass parts is more preferable. If content of a component (E) is 0.1 mass part or more with respect to 100 mass parts of components (A), the adhesive improvement effect will be easy to be acquired. On the other hand, even if content of a component (E) exceeds 100 mass parts with respect to 100 mass parts of components (A), the adhesive improvement effect will be in a saturated state.

When the base treatment layer 31 is provided by various processes, the resin (A1) and the resin (A2) constituting the component (A) react with each other to form a cross-linked site, thereby improving heat resistance. By forming a cross-linked site different from the cross-linked site formed in this manner in the base treatment layer 31, the heat resistance can be further improved.
Examples of the additive for forming the other cross-linked site include the following component (F). That is, the heat resistance of the base treatment layer 31 is further improved by further increasing the crosslink density of the base treatment layer 31 due to the component (F).
(F) Metal compounds other than the component (E).

  As the component (F), a metal compound that ionically dissociates in a solution state when blended in a coating composition containing a component forming the base treatment layer 31 and a liquid medium (solvent or dispersion medium) can be used. After the coating composition is applied on the aluminum foil layer 13 by various coating methods, the liquid medium is volatilized to react the resin (A1) and the resin (A2) and dissociate the metal ions from the component (F). Acts on the component (A) (for example, acts on an unreacted carboxy group of the resin (A2-1) or an unreacted amino group of the resin (A1-2)) to form an ionic bridge.

Component (F) is ion-dissociated when dissolved in a coating composition (has solubility in a solvent), and the dissociated metal ions act on component (A) to form ionic crosslinks. Any water-soluble metal compound is preferable. For example, the following component (F1) and component (F2) are mentioned.
(F1) A metal compound that makes the aqueous solution acidic.
(F2) A metal compound that makes the aqueous solution basic.

Examples of the component (F1) include hydrochlorides, sulfates, nitrates, and hydrofluoric salts of various metals. Examples of the metal of the metal compound include zinc, iron, manganese, copper, chromium, zirconium, and cobalt. The metal may be an alkali (earth) metal such as sodium or calcium.
Examples of the component (F2) include zirconium compounds such as zirconium ammonium carbonate and zirconium fluoride ammonium.

The aqueous solution containing the component (F1) is acidic. In this case, as the component (A), considering the same water-soluble acidic solution, the component (A) is composed of the resin (A1-1) and the resin (A2-1), and the resin (A2-1) is used. It is necessary to use poly (meth) acrylic acid or a copolymer of (meth) acrylic acid and another polymerizable monomer. However, since the resin (A1-1) has an oxazoline group (basic), the resin (A1-1) and the resin (A2-1) gradually react in the coating composition before coating, and the coating is appropriate. (Influence on pot life of coating composition). In this respect, an ion salt (ion neutralized product) such as an ammonium salt or a sodium salt is used as the resin (A2-1) to suppress the reaction between the carboxyl group and the oxazoline group in the coating composition before coating. It is preferable that the carboxyl group and the oxazoline group react when the coating composition is dried and formed into a film. In this case, the resin (A2-1) is more preferably an ammonium salt that hardly remains as an impurity when the coating composition is dried and formed into a film.
As described above, since the coating composition for forming the base treatment layer 31 is preferably a basic solution before application, the aqueous solution containing the component (F) is also preferably basic. Therefore, as the component (F), the component (F2) is preferable from the viewpoint of pot life and stability of the coating composition, and zirconium compounds such as zirconium ammonium carbonate and zirconium ammonium fluoride are particularly preferable.

The component (F) contained in the base treatment layer 31 may be one type or two or more types.
0.1-100 mass parts is preferable with respect to 100 mass parts of components (A), and, as for content in the metal conversion of the component (F) in the base treatment layer 31, 0.5-50 mass parts is more preferable, 1-30 mass parts is further more preferable. When the content of the component (F) in terms of metal is 0.1 parts by mass or more with respect to 100 parts by mass of the component (A), the effect of improving the adhesion by the component (F) is easily obtained. When the content of the component (F) in terms of metal is 100 parts by mass or less with respect to 100 parts by mass of the component (A), the component (F) remains in the base treatment layer 31 as an unreacted substance and has a cohesive force. It is easy to suppress that falls.

The base treatment layer 31 is made of an aluminum foil formed of a coating composition containing the resin (A1) and the resin (A2) forming the component (A), a liquid medium (solvent or dispersion medium), and other components as necessary. It can be formed by coating on the layer 13 and drying curing. When the base treatment layer 31 further includes the component (B), the component (B) may be blended in the same coating composition as the resin (A1) and the resin (A2) forming the component (A), and different coating compositions. It may be blended into the product. When blended in different coating compositions, a layer containing the component (A) and the component (B) can be formed by sequentially coating and drying these coating compositions. A method for forming the base treatment layer 31 will be described in detail later.
The thickness of the base treatment layer 31 is preferably 0.001 to 1 μm. When the thickness of the base treatment layer 31 is 0.001 μm or more, the adhesion between the base material layer 11 and the aluminum foil layer 13 is sufficiently improved. If the thickness of the base treatment layer 31 is 1 μm or less, the moldability is improved, and the amount of heat necessary for the crosslinking reaction is not excessively increased, and the drying curing process is facilitated, so that productivity is improved.

(Manufacturing method of exterior material 3)
The packaging material 3 can be manufactured, for example, by a manufacturing method having the following steps (1 ″) to (5 ″).
(1 ″) A step of forming a corrosion prevention treatment layer 14 on one surface of the aluminum foil layer 13 by performing a corrosion prevention treatment.
(2 ″) A step of forming the base treatment layer 31 on the side of the aluminum foil layer 13 opposite to the side on which the corrosion prevention treatment layer 14 is formed.
(3 ″) A step of bonding the base material layer 11 to the side of the aluminum foil layer 13 on which the base treatment layer 31 is formed via the first adhesive layer 12.
(4 ″) A step of bonding the sealant layer 16 to the side of the aluminum foil layer 13 on which the corrosion prevention treatment layer 14 has been formed via the second adhesive layer 25.
(5 ″) A laminate including the base material layer 11, the first adhesive layer 12, the base treatment layer 31, the aluminum foil layer 13, the corrosion prevention treatment layer 14, the second adhesive layer 25, and the sealant layer is heat-treated. Process.

  Steps (1 ″), (3 ″), (4 ″), and (5 ″) are steps (1 ′), (2 ′), (3 ′) in the manufacturing method described as the method for manufacturing the outer packaging material 2, respectively. ) And (4 ′).

Process (2 "):
The base treatment layer 31 can be formed by forming and curing a layer containing the resin (A1) and the resin (A2).
The layer can be formed by applying and drying a coating composition containing each component and a liquid medium.
As the liquid medium, various solvents such as water, alcohol solvents, hydrocarbon solvents, ketone solvents, ester solvents and ether solvents can be used. Of these, water is preferred. The amount of the liquid medium to be used is not particularly limited as long as it is within a range where the coating composition can be applied.

  When the base treatment layer 31 includes the component (B) (and further includes the component (C)), these components may be blended in one coating composition together with the resin (A1) and the resin (A2), and are different. You may mix | blend with a coating composition. For example, a coating composition containing the resin (A1) and the resin (A2), a coating composition containing the component (B) and the component (C) are prepared, and the coating compositions are sequentially applied and dried. A layer containing the resin (A1), the resin (A2), the component (B), and the component (C) can be formed.

Examples of the coating composition coating method include gravure coating, gravure reverse coating, roll coating, reverse roll coating, micro gravure coating, comma coating, air knife coating, Mayer bar coating, dip coating, die coating, and spray coating. Various coating methods can be employed.
The layer is preferably dried and cured (dry cure) so that the base material temperature is in the range of 80 to 250 ° C.
However, when the step (5 ″) is performed, the resin (A1) and the resin (A2) may not form the crosslinked resin (component (A)) at the end of the step (2 ″).

The manufacturing method of the laminated body which comprises the exterior material 3 is not limited to said manufacturing method.
For example, the step (1 ″) may be performed after performing the step (2 ″).
In the step (1 ″), a corrosion prevention treatment layer may be provided on both surfaces of the aluminum foil layer, and in the step (2 ″), the base treatment layer 31 may be provided on one of the corrosion prevention treatment layers.
Further, the step (3 ″) may be performed after the step (4 ″) is performed.
Moreover, the method which does not perform a process (5 '') may be sufficient.
Before the step (3 ″), on the surface of the film constituting the base material layer 11 opposite to the side to be bonded to the aluminum foil layer 13 (the surface to be the surface 3a on the outermost layer side of the exterior material 3), You may perform the process of giving surface treatments, such as application | coating of the said surface modifier, a surface modification process, etc., and obtaining the base material layer 11. In the process (3 ''), it replaces with the said base material layer 11, said 5 Using a film having a contact angle after 10 seconds of less than 10 ° or more than 30 °, and after the step (3 ″), the step (4 ″) or the step (5 ″), on the surface of the obtained laminate on the film side The step of applying the surface modifier, surface treatment such as surface modification treatment, and the like to make the film the base material layer 11 may be performed.
After the step (5 ″) or after the step (4 ″), a step of applying a slip material and / or an antiblocking material to the outermost layer and / or the innermost layer of the obtained laminate is performed as necessary. May be.

As mentioned above, although the exterior material of this invention was demonstrated by showing 1st Embodiment-3rd Embodiment, this invention is not limited to these embodiment. Each configuration in the above embodiment, a combination thereof, and the like are examples, and the addition, omission, replacement, and other modifications of the configuration can be made without departing from the spirit of the present invention.
For example, in the packaging materials 1 to 3 of the first to third embodiments, the corrosion prevention treatment layers 14 may be provided on both surfaces of the aluminum foil layer 13.
In the exterior material 3 of the third embodiment, an adhesive resin layer 15 may be provided instead of the second adhesive layer 25.

The exterior material of this invention is used for manufacture of a lithium ion battery.
The form of the lithium ion battery in which the exterior material of the present invention is used is not particularly limited as long as a part or the whole of the casing is constituted by a laminate film, and a known form can be adopted, for example, cold forming A part in which the casing is partly or wholly composed of a molded product to which is applied. In such applications, the exterior material of the present invention can be formed into a molded product by cold forming. In cold forming, a recess for storing battery cells (positive electrode, separator, negative electrode) is usually formed. Cold forming is a forming method performed at room temperature, and examples thereof include press forming such as deep drawing forming and stretch forming.
A well-known manufacturing method can be employ | adopted for manufacture of the lithium ion battery using the exterior material of this invention.

In the production process of the lithium ion battery, printing is performed on the outermost layer side surface of the exterior material of the present invention using ink. For example, after manufacturing a lithium ion battery using an exterior material, a bar coat, a logo, etc. are printed on the surface of the exterior material on the base material layer side (the outer surface of the lithium ion battery), and the lithium ion battery with a printed layer It is said.
As an ink printing method, inkjet printing is preferable in that continuous numbers can be automatically printed in consideration of lot tracing.
The ink can be appropriately selected from known inks in consideration of the printing method and the like. For example, in the case of inkjet printing, the ink is preferably an organic solvent from the viewpoint of quick drying, and the ink solvent is preferably methyl ethyl ketone or a mixed solvent containing methyl ethyl ketone as a main component.
“A mixed solvent containing methyl ethyl ketone as a main component” refers to a mixed solvent of methyl ethyl ketone and another organic solvent, wherein the content of methyl ethyl ketone in the mixed solvent is 90% by mass or more and less than 100% by mass. .

Hereinafter, the present invention will be described in detail with reference to examples. However, the present invention is not limited to these examples.
The materials used in the following examples are as follows.

<Materials used>
[Base material layer 11]
Base material A: Biaxially stretched nylon film (“N1102”, Toyobo Co., Ltd., thickness 25 μm).
Substrate B: Nylon film manufactured by a tubular method (“RX” by Kojin Film & Chemicals, thickness 25 μm).
Substrate C: Nylon film manufactured by the tubular method (“G100”, Idemitsu Unitech Co., Ltd., thickness 25 μm).
Base material D: Biaxially stretched nylon film (“SNR” manufactured by Mitsubishi Plastics, Inc., thickness 25 μm).
Base material E: Biaxially stretched nylon film (“N1102”, Toyobo Co., Ltd., thickness 15 μm).
Substrate F: Biaxially stretched nylon film (“N1202” manufactured by Toyobo Co., Ltd., thickness: 15 μm).

[First adhesive layer 12]
Adhesive AD-1: Polyurethane-based adhesive (manufactured by Toyo Ink) in which an adduct-based curing agent of tolylene diisocyanate is blended with a polyester polyol-based main agent.

[Underlayer 31]
Base treatment agent PL-1: a mixture composed of 90% by mass of polyacrylic acid ammonium salt (manufactured by Toagosei Co., Ltd.) and 10% by mass of acrylic-isopropenyl oxazoline copolymer (manufactured by Nippon Shokubai Co., Ltd.), and 100 parts by mass of cerium oxide A coating composition obtained by mixing a sodium polyphosphate-stabilized cerium oxide sol containing 10 parts by mass of sodium phosphate. The blending amount of the sodium polyphosphate-stabilized cerium oxide sol was 4000 parts by mass with respect to 100 parts by mass of the mixture.

[Aluminum foil layer 13]
Aluminum foil AL-1: An annealed degreased 40 μm thick soft aluminum foil 8079 material (manufactured by Toyo Aluminum).

[Corrosion prevention treatment layer 14]
Treatment agent CL-1: A sodium polyphosphate-stabilized cerium oxide sol containing 10 parts by mass of sodium salt of phosphoric acid per 100 parts by mass of cerium oxide and adjusted to a solid content concentration of 10% by mass using distilled water as a solvent.
Treatment agent CL-2: A mixture of 90% by mass of polyacrylic acid ammonium salt (manufactured by Toagosei Co., Ltd.) and 10% by mass of acryl-isopropenyl oxazoline copolymer (manufactured by Nippon Shokubai Co., Ltd.), distilled water as a solvent, A composition adjusted to a partial concentration of 5% by mass.
Treatment agent CL-3: A mixture of 90% by mass of polyallylamine (manufactured by Nittobo) and 10% by mass of polyglycerol polyglycidyl ether (manufactured by Nagase ChemteX), using distilled water as a solvent, and a solid content concentration of 5% by mass The composition adjusted to.

[Second adhesive layer 25]
Adhesive AD-2: An adhesive composition in which a polyisocyanate compound having an isocyanurate structure is blended at 10 parts by mass (solid content ratio) with respect to 100 parts by mass of maleic anhydride-modified polyolefin resin dissolved in toluene.

[Adhesive resin layer 15]
Adhesive resin AR-1: Modified polyolefin resin (manufactured by Mitsui Chemicals) in which a rubber component (elastomer phase) is blended with modified PP obtained by graft-modifying maleic anhydride to random polypropylene (PP).

[Sealant layer 16]
Film SL-1: Multilayer film (made by Okamoto) consisting of two types and three layers of random PP / block PP / random PP with a total thickness of 30 μm.

<Examples 1-3, Comparative Examples 1-2>
The exterior material having the layer structure shown in FIG. 3 was manufactured by the following procedure.
Step (I):
On one side of the aluminum foil layer 13 (aluminum foil AL-1) (side filled with electrolyte), CL-1 is applied and dried, then CL-2 is applied and dried, and then CL -3 was coated and dried to provide a corrosion prevention treatment layer 14. Each treatment agent was applied by microgravure coating. The coating amount of the processing agents CL-1 to CL-3 is set so that the total dry coating amount is 70 to 100 mg / m ^2, and drying (baking processing) after coating is performed by the type of coating agent in the drying unit. Depending on the temperature, it was carried out at 150 to 250 ° C.

Step (II):
On the opposite surface of the aluminum foil layer 13 provided with the corrosion prevention treatment layer 14, a ground treatment agent PL-1 was applied and dried to provide a ground treatment layer 31 (thickness 0.030 μm). The surface treatment agent was applied by microgravure coating. The coating amount was 70 to 100 mg / m ² as a dry coating amount, and drying (baking treatment) after coating was performed at 120 to 200 ° C.

Step (III):
Using the adhesive AD-1 on the base treatment layer 31 side of the aluminum foil layer 13 provided with the corrosion prevention treatment layer 14 on one side and the base treatment layer 31 on the other side, the base materials (bases) shown in Table 1 are used. Any one of materials A to E) was bonded. At this time, lamination was performed by gravure reverse coating so that the adhesive AD-1 was 4 to 5 g / m ² as a dry coating amount. Then, adhesive agent AD-1 was hardened by performing an aging process. Thereby, the laminated body of the layer structure of base material layer 11 / first adhesive layer 12 / base treatment layer 31 / aluminum foil layer 13 / corrosion prevention treatment layer 14 was obtained.

Step (IV):
The sealant layer 16 is bonded via the second adhesive layer 25 by laminating the film SL-1 using the adhesive AD-2 on the corrosion prevention treatment layer 14 side of the laminate obtained in the step (III). Laminated. At this time, lamination was performed by gravure reverse coating so that the adhesive was 3 to 5 g / m ² as a dry coating amount. Then, the adhesive was hardened by performing an aging process. Thereby, the laminated body of the layer constitution of base material layer 11 / first adhesive layer 12 / base treatment layer 31 / aluminum foil layer 13 / corrosion prevention treatment layer 14 / second adhesive layer 25 / sealant layer 16 is obtained. Obtained.

Step (V):
The laminated body obtained in the step (IV) was passed between thermocompression-bonded rolls heated to 150 to 200 ° C. to perform heat treatment to obtain an exterior material.
About the obtained exterior material, the following measurements and evaluation were performed.

[Measurement of contact angle over time and contact angle after 5 seconds]
Time variation of contact angle (MEK contact angle) in 2 seconds or 5 seconds after the drop of methyl ethyl ketone (MEK) is deposited on the surface of the base material layer 11 side of the exterior material, MEK 5 seconds after the deposition Each contact angle was measured by the procedure described above. The results are shown in Table 1.

[Evaluation of printability]
A barcode was printed on the surface of the exterior material on the side of the base material layer 11 by an ink jet printer using an ink whose ink solvent was MEK, and an evaluation sample was prepared.
For each of the 10 evaluation samples, a barcode scanner was used to evaluate whether the barcode could be read. In addition, the extent of spreading of the ink dots printed visually was evaluated. From these results, printability was evaluated according to the following criteria. The results are shown in Table 2.
<Criteria>
A: The barcode can be read and the ink dots do not spread.
○: The barcode could be read but the ink dots spread.
X: Bar code could not be read.

Moreover, comprehensive evaluation was performed from the evaluation results of 10 evaluation samples according to the following criteria. The results are shown in Table 2.
<Criteria>
A: All of the evaluation results of the ten evaluation samples were A.
◯: The evaluation results of 10 evaluation samples were ◯ or ◎, and at least one was ◯.
X: At least one of the evaluation results of 10 evaluation samples was x.

As shown in the above results, the time change (5 seconds) of the MEK contact angle on the surface on the base layer 11 side is 6 ° or less, and the MEK contact angle after 5 seconds is 10 ° or more and 30 ° or less. The packaging materials 1 to 3 were able to print well with an ink whose ink solvent was MEK.
On the other hand, the time change (5 seconds) of the MEK contact angle is over 6 ° and the MEK contact angle after 5 seconds is less than 10 °, and the time change (5 seconds) of the MEK contact angle is over 6 °. When the exterior material of Comparative Example 2 was printed with ink whose ink solvent was MEK, printing failure occurred.

<Example 4, Comparative Example 3>
In order to confirm the effect of the surface treatment on the substrate surface, an exterior material was manufactured by the following procedure.
In Example 4, a higher fatty acid ester-modified silicone oil (“TSF410” manufactured by Momentive Performance Materials Japan) was dispersed in isopropyl alcohol so as to have a solid content concentration of 0.04% by mass. The dry coating amount was applied to the surface with a wire bar so that the dry coating amount was 2.5 mg / m ² and dried. This was designated as substrate F (with surface treatment). This substrate F (with surface treatment) was used in the same procedure as in Example 1 except that the surface treated with silicone oil was used outside (the surface opposite to the adhesive surface of the first adhesive layer). An exterior material was produced.
In Comparative Example 3, an exterior material was produced in the same procedure as in Example 4 except that the base material F was used as it was without performing surface treatment.
The obtained exterior material was subjected to [Measurement of contact angle with time and measurement of contact angle after 5 seconds] and [Evaluation of printability] in the same manner as described above. The results are shown in Tables 3 and 4.

  As shown in the above results, the exterior material of Comparative Example 3 using the base material F (without surface treatment) having a MEK contact angle of less than 10 ° after 5 seconds was printed with an ink whose ink solvent is MEK. Sometimes printing failure occurred. On the other hand, by subjecting the same base material to surface treatment, the time change (5 seconds) of the MEK contact angle on the surface on the base material layer 11 side is 6 ° or less, and the MEK contact angle after 5 seconds is 10 ° or more. The packaging material of Example 4 that was set to 30 ° or less was able to print well with ink whose ink solvent was MEK.

  According to the exterior material of the present invention, after assembling a lithium ion battery using the exterior material, design printing or inkjet printer on the outer surface of the exterior material for anti-counterfeiting, design by design, lot tracing, etc. When performing bar code printing with, printing defects are unlikely to occur. Therefore, it becomes possible to stably produce a lithium ion battery on which printing as described above has been performed.

DESCRIPTION OF SYMBOLS 1 Exterior material for lithium ion batteries 2 Exterior material for lithium ion batteries 3 Exterior material for lithium ion batteries 11 Base material layer 12 First adhesive layer 13 Aluminum foil layer 14 Corrosion prevention treatment layer 15 Adhesive resin layer 16 Sealant layer 25 Second adhesive layer 31 Ground treatment layer

Claims (5)

At least one base material layer, a first adhesive layer, an aluminum foil layer provided with a corrosion prevention treatment layer on at least one surface, an adhesive resin layer or a second adhesive layer, and a sealant layer It is composed of a laminate formed by laminating in this order, and is a lithium ion battery exterior material that is printed on the surface on the base material layer side,
When a coating film of a surface modifier is formed on the surface of the base material layer side, when the droplets of the ink solvent contained in the ink used for the printing are deposited , the droplets are deposited A contact angle after 5 seconds from 10 ° to 30 °, and a change in contact angle after landing of the liquid droplets within 5 seconds is 6 ° or less. The exterior material for a lithium ion battery according to claim 1 , wherein the surface modifier is silicone oil. The exterior material for a lithium ion battery according to claim 1 or 2 , wherein the printing is inkjet printing. The exterior material for a lithium ion battery according to any one of claims 1 to 3 , wherein the ink solvent is an organic solvent. The exterior material for a lithium ion battery according to claim 4 , wherein the ink solvent is methyl ethyl ketone or a mixed solvent containing methyl ethyl ketone as a main component.

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