JP6769142B2 - Battery packaging materials, their manufacturing methods and batteries - Google Patents

Description

The present invention relates to a packaging material for a battery, a method for producing the same, and a battery.

Conventionally, various types of batteries have been developed, but in all batteries, a packaging material is an indispensable member for sealing a battery element such as an electrode or an electrolyte. Conventionally, metal packaging materials have been widely used for battery packaging.

On the other hand, in recent years, along with the high performance of electric vehicles, hybrid electric vehicles, personal computers, cameras, mobile phones, etc., batteries are required to have various shapes, and are required to be thinner and lighter. However, the metal packaging material for batteries, which has been widely used in the past, has a drawback that it is difficult to keep up with the diversification of shapes and there is a limit to weight reduction.

Therefore, in recent years, as a packaging material for batteries that can be easily processed into various shapes and can be made thinner and lighter, a film-like laminate in which a base material / metal layer / thermosetting resin layer is sequentially laminated. Has been proposed (see, for example, Patent Document 1).

In such a packaging material for batteries, recesses are generally formed by cold molding, and battery elements such as electrodes and electrolytic solutions are arranged in the space formed by the recesses, and heat-sealing resin layers are arranged with each other. By heat-sealing the batteries, a battery in which the battery element is housed inside the packaging material for the battery can be obtained.

Japanese Unexamined Patent Publication No. 2008-287971

In recent years, with the demand for smaller and thinner batteries, further thinning of the packaging material for batteries is required. However, when the thickness of the battery packaging material is extremely thin, for example, 90 μm or less, further 80 μm or less, the metal layer is also very thin, for example, 30 μm or less, further 25 μm or less, and cracks and pins are formed during molding. There is a problem that it becomes difficult to avoid the occurrence of holes.

Under such circumstances, an object of the present invention is to provide a packaging material for a battery having excellent moldability.

The present inventor has made diligent studies to solve the above problems. As a result, the thickness of the base material layer is set to 60% or more of the thickness of the metal layer in at least a packaging material for a battery composed of a laminate including a base material layer, a metal layer, and a thermosetting resin layer in this order. As a result, even when the thickness of the metal layer is very thin (for example, 30 μm or less, further 25 μm or less) and the thickness of the packaging material for the battery is also very thin (for example, 90 μm or less, further 80 μm or less). It has been found that it has excellent moldability. The present invention has been completed by further studies based on these findings.

That is, the present invention provides the inventions of the following aspects.
Item 1. It is composed of a laminate having at least a base material layer, a metal layer, and a thermosetting resin layer in this order.
A packaging material for a battery in which the thickness of the base material layer is 60% or more of the thickness of the metal layer.
Item 2. Item 2. The packaging material for a battery according to Item 1, wherein the thickness of the metal layer is 30 μm or less.
Item 3. Item 2. The packaging material for a battery according to Item 1 or 2, wherein the thickness of the laminate is 90 μm or less.
Item 4. Item 2. The battery packaging material according to any one of Items 1 to 3, wherein the metal layer is made of an aluminum alloy foil.
Item 5. Item 2. The packaging material for a battery according to any one of Items 1 to 4, wherein a lubricant is present on the surface of the base material layer.
Item 6. Item 2. The packaging material for a battery according to any one of Items 1 to 5, wherein the base material layer contains at least one of polyester and polyamide.
Item 7. A battery in which a battery element including at least a positive electrode, a negative electrode, and an electrolyte is housed in a package formed of the battery packaging material according to any one of Items 1 to 6.
Item 8. At least, it includes a step of laminating the base material layer, the metal layer, and the thermosetting resin layer in this order to obtain a laminate.
A method for producing a packaging material for a battery, wherein the base material layer has a thickness of 60% or more of the thickness of the metal layer.

According to the present invention, it is possible to provide a packaging material for a battery having excellent moldability. Further, the battery packaging material of the present invention can make the thickness of the metal layer and the thickness of the battery packaging material very thin, so that the energy density of the battery can be increased.

It is a schematic diagram which shows an example of the cross-sectional structure of the packaging material for a battery of this invention. It is a schematic diagram which shows an example of the cross-sectional structure of the packaging material for a battery of this invention. It is a schematic diagram which shows an example of the cross-sectional structure of the packaging material for a battery of this invention. It is a schematic diagram which shows the crystal grain and the second phase particle in the thickness direction of a metal layer.

The packaging material for a battery of the present invention is composed of a laminate having at least a base material layer, a metal layer, and a thermosetting resin layer in this order, and the thickness of the base material layer is 60% or more of the thickness of the metal layer. It is characterized by being. Hereinafter, the packaging material for batteries of the present invention will be described in detail.

In addition, in this specification, the display of "~" indicating a numerical range indicates that it is equal to or more than the numerical value attached to the left side thereof and less than or equal to the numerical value attached to the right side thereof, for example, the numerical range “XY”. "" Means that it is X or more and Y or less.

1. 1. Laminated structure of battery packaging material As shown in FIG. 1, the battery packaging material 10 of the present invention is composed of a laminate having at least a base material layer 1, a metal layer 3, and a thermosetting resin layer 4 in this order. Become. In the packaging material for batteries of the present invention, the base material layer 1 is on the outermost layer side, and the thermosetting resin layer 4 is on the innermost layer. That is, when assembling the battery, the thermosetting resin layers 4 located on the peripheral edge of the battery element are heat-sealed to each other to seal the battery element, thereby sealing the battery element.

As shown in FIG. 2, in the battery packaging material 10 of the present invention, an adhesive layer 2 is provided between the base material layer 1 and the metal layer 3 as needed for the purpose of enhancing their adhesiveness. You may be. Further, as shown in FIG. 3, the battery packaging material 10 of the present invention has an adhesive layer between the metal layer 3 and the thermosetting resin layer 4 for the purpose of enhancing the adhesiveness thereof, if necessary. 5 may be provided.

The thickness of the laminate constituting the battery packaging material 10 of the present invention is not particularly limited, but the battery packaging material has excellent moldability while reducing the thickness of the battery packaging material to increase the energy density of the battery. From the viewpoint, for example, 90 μm or less, preferably 80 μm or less, more preferably 40 μm to 80 μm, and further preferably 40 μm to 70 μm can be mentioned. As the thickness of the battery packaging material becomes thinner, such as 90 μm or less, 80 μm or less, and 70 μm or less, pinholes are likely to occur during molding. However, in the present invention, the thickness of the base material layer 1 is the thickness of the metal layer 3. Since it is set to 60% or more, it is possible to exhibit excellent moldability even when the thickness is thin as described above. When the thickness of the battery packaging material is reduced to less than 40 μm, the moldability is significantly reduced. Therefore, the lower limit of the thickness of the battery packaging material of the present invention is preferably about 40 μm.

2. Composition of each layer forming the packaging material for batteries [Base material layer 1]
In the packaging material for batteries of the present invention, the base material layer 1 is a layer located on the outermost layer side. In the present invention, the thickness of the base material layer 1 is 60% or more of the thickness of the metal layer 3 described later. As a result, even when the thickness of the metal layer is very thin (for example, 30 μm or less) and the thickness of the battery packaging material is also very thin (for example, 90 μm or less, further 80 μm or less), the moldability is excellent. It is a packaging material for batteries. The details of this mechanism are not always clear, but can be considered, for example, as follows. That is, the tensile strength and the impact strength are improved in proportion to the thickness of the base material layer, but when the thickness of the base material layer 1 is 60% or more of the thickness of the metal layer 3, the male mold is formed at the time of molding. When narrowing down to packaging materials for batteries, the change in the thickness of the molding corner where the pressure load is highest is small, and the change in the thickness of the metal layer that changes at the same time is also small, so that the occurrence of pinholes in the molding corner can be effectively suppressed. It is considered to be.

From the viewpoint of further improving the moldability while reducing the thickness of the battery packaging material, the thickness of the base material layer 1 is preferably 60% to 170% of the thickness of the metal layer 3. More preferably, when the thickness of the metal layer 3 is about 15 μm to 30 μm and the thickness of the base material layer 1 is about 10 μm to 20 μm, the thickness ratio may be 60% to 100%. preferable. When the thickness of the metal layer 3 is about 15 μm to 30 μm and the thickness of the base material layer 1 is about 23 μm to 30 μm, the thickness ratio is preferably 80% to 170%.

More specifically, when the thickness of the metal layer 3 is about 15 μm to 20 μm and the base material layer 1 is made of a nylon film having a thickness of about 10 μm to 20 μm, the thickness ratio is 70% to 100. It is particularly preferable to set it to%. When the metal layer 3 has a thickness of about 15 μm to 20 μm and the base material layer 1 is made of a polyester film having a thickness of about 10 μm to 20 μm, the thickness ratio should be 60% to 75%. Is particularly preferable. Further, when the thickness of the metal layer 3 is about 15 μm to 20 μm and the base material layer 1 is composed of a laminate of a polyester film and a nylon film (thickness is about 10 μm to 20 μm), the thickness ratio is determined. It is particularly preferably 60% to 70%. From the same viewpoint, the thickness of the base material layer 1 is preferably 12 μm or more, more preferably 15 μm to 40 μm, and further preferably 20 μm to 35 μm.

The material forming the base material layer 1 is not particularly limited as long as it has an insulating property. Examples of the material forming the base material layer 1 include polyester, polyamide, epoxy resin, acrylic resin, fluororesin, polyurethane, silicon resin, phenol resin, polyetherimide, polyimide, and a mixture or copolymer thereof. Can be mentioned. From the viewpoint of improving the insulating property and moldability of the battery packaging material, the base material layer 1 preferably contains at least one of polyester and polyamide.

Specific examples of the polyester include a copolymerized polyester containing polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, polycarbonate, and ethylene terephthalate as repeating units, and butylene terephthalate as repeating units. Examples thereof include copolymerized polyester as a main component. Further, as the copolymerized polyester having ethylene terephthalate as the main body of the repeating unit, specifically, a copolymer polyester having ethylene terephthalate as the main body of the repeating unit and polymerizing with ethylene isophthalate (hereinafter, polyethylene (terephthalate / isophthalate)). (Abbreviated after), polyethylene (terephthalate / isophthalate), polyethylene (terephthalate / adipate), polyethylene (terephthalate / sodium sulfoisophthalate), polyethylene (terephthalate / sodium isophthalate), polyethylene (terephthalate / phenyl-dicarboxylate) , Polyethylene (terephthalate / decandicarboxylate) and the like. Further, as the copolymerized polyester having butylene terephthalate as the main body of the repeating unit, specifically, a copolymer polyester which polymerizes with butylene isophthalate using butylene terephthalate as the main body of the repeating unit (hereinafter, polybutylene (terephthalate / isophthalate)). (Abbreviated after), polybutylene (terephthalate / adipate), polybutylene (terephthalate / sevacate), polybutylene (terephthalate / decandicarboxylate), polybutylene naphthalate and the like. These polyesters may be used alone or in combination of two or more. Polyester has an advantage that it has excellent electrolytic solution resistance and whitening is unlikely to occur due to adhesion of the electrolytic solution, and is preferably used as a material for forming the base material layer 1.

Further, as the polyamide, specifically, an aliphatic polyamide such as nylon 6, nylon 66, nylon 610, nylon 12, nylon 46, a copolymer of nylon 6 and nylon 6, 6; terephthalic acid and / or Hexamethylenediamine-isophthalic acid-terephthalic acid copolymerized polyamides such as nylon 6I, nylon 6T, nylon 6IT, nylon 6I6T (I stands for isophthalic acid and T stands for terephthalic acid) containing structural units derived from isophthalic acid, polymetaki. Aroma-containing polyamides such as silylene adipamide (MXD6); alicyclic polyamides such as polyaminomethylcyclohexyl adipamide (PACM6); and lactam components and isocyanate components such as 4,4'-diphenylmethane-diisocyanate. Examples thereof include polymerized polyamides, polyesteramide copolymers and polyetheresteramide copolymers which are copolymers of copolymerized polyamides and polyesters and polyalkylene ether glycols; and copolymers thereof. These polyamides may be used alone or in combination of two or more. The stretched polyamide film is excellent in stretchability, can prevent whitening due to resin cracking of the base material layer 1 during molding, and is suitably used as a material for forming the base material layer 1.

The base material layer 1 may be formed of a uniaxially or biaxially stretched resin film, or may be formed of an unstretched resin film. Among them, a uniaxially or biaxially stretched resin film, particularly a biaxially stretched resin film, has improved heat resistance due to orientation crystallization, and is therefore preferably used as the base material layer 1. Further, the base material layer 1 may be formed by coating the above material on the metal layer 3.

Among these, as the resin film forming the base material layer 1, nylon, polyester, more preferably biaxially stretched nylon, biaxially stretched polyester, and particularly preferably biaxially stretched nylon can be mentioned.

In the base material layer 1, at least one of resin films and coatings of different materials can be laminated (multilayer structure) in order to improve pinhole resistance and insulation when used as a battery package. is there. Specific examples thereof include a multilayer structure in which a polyester film and a nylon film are laminated, a multilayer structure in which a plurality of nylon films are laminated, and a multilayer structure in which a plurality of layers of a polyester film are laminated. When the base material layer 1 has a multilayer structure, a laminate of a biaxially stretched nylon film and a biaxially stretched polyester film, a laminate in which a plurality of biaxially stretched nylon films are laminated, and a laminate in which a plurality of biaxially stretched polyester films are laminated. The body is preferred. Further, since the biaxially stretched polyester is difficult to discolor when the electrolytic solution adheres to the surface, for example, the base material layer 1 has a multilayer structure of a biaxially stretched nylon film and a biaxially stretched polyester film. The base material layer 1 is preferably a laminate in which biaxially stretched nylon and biaxially stretched polyester are provided in this order from the metal layer 3 side. When the base material layer 1 has a multilayer structure, the thickness of each layer is preferably 2 μm to 10 μm.

When the base material layer 1 has a multilayer structure, the resin films may be adhered via an adhesive, or may be directly laminated without an adhesive. When bonding without using an adhesive, for example, a method of bonding in a heat-melted state such as a coextrusion method, a sandwich laminating method, and a thermal laminating method can be mentioned. When adhering via an adhesive, the adhesive used may be a two-component curable adhesive or a one-component curable adhesive. Further, the adhesive mechanism of the adhesive is not particularly limited, and may be any of a chemical reaction type, a solvent volatilization type, a heat melting type, a thermal pressure type, an electron beam curing type such as UV and EB, and the like. Specific examples of the adhesive include the same adhesives as those exemplified in the adhesive layer 2. Further, the thickness of the adhesive can be the same as that of the adhesive layer 2.

In the present invention, from the viewpoint of improving the moldability of the packaging material for batteries, it is preferable that a lubricant is attached to the surface of the base material layer 1. The lubricant is not particularly limited, but an amide-based lubricant is preferable. Specific examples of the amide-based lubricant include saturated fatty acid amides, unsaturated fatty acid amides, substituted amides, methylol amides, saturated fatty acid bisamides, and unsaturated fatty acid bisamides. Specific examples of the saturated fatty acid amide include lauric acid amide, partiminic acid amide, stearic acid amide, bechenic acid amide, hydroxystearic acid amide and the like. Specific examples of unsaturated fatty acid amides include oleic acid amides and erucic acid amides. Specific examples of the substituted amide include N-oleyl partimate amide, N-stearyl stearic acid amide, N-stearyl oleic acid amide, N-oleyl stearic acid amide, N-stearyl erucic acid amide and the like. Further, specific examples of methylolamide include methylolstearic acid amide. Specific examples of the saturated fatty acid bisamide include methylene bisstearic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide, ethylene bisstearic acid amide, ethylene bishydroxystearic acid amide, ethylene bisbechenic acid amide, and hexamethylene bisstearate. Examples thereof include acid amides, hexamethylene bisbechenic acid amides, hexamethylene hydroxystearic acid amides, N, N'-distearyl adipate amides, and N, N'-distealyl sebasic acid amides. Specific examples of unsaturated fatty acid bisamides include ethylene bisoleic acid amide, ethylene biserucic acid amide, hexamethylene bisoleic acid amide, N, N'-diorail adipate amide, and N, N'-diorail sebacic acid amide. And so on. Specific examples of the fatty acid ester amide include stearoamide ethyl stearate and the like. Specific examples of the aromatic bisamide include m-xylylene bisstearic acid amide, m-xylylene bishydroxystearic acid amide, and N, N'-cystarylisophthalic acid amide. One type of lubricant may be used alone, or two or more types may be used in combination.

When the lubricant is present on the surface of the base material layer 1, the abundance thereof is not particularly limited, but is preferably 3 mg / m ² or more, more preferably 4 mg / m ^{2 to} 15 mg at a temperature of 24 ° C. and a humidity of 60%. / m ^2, more preferably include ^{5mg / m 2 ~14mg / m 2} .

[Adhesive layer 2]
In the battery packaging material 10 of the present invention, the adhesive layer 2 is a layer provided between the base material layer 1 and the metal layer 3 as necessary in order to firmly bond them.

The adhesive layer 2 is formed of an adhesive capable of adhering the base material layer 1 and the metal layer 3 to each other. The adhesive used to form the adhesive layer 2 may be a two-component curable adhesive or a one-component curable adhesive. Further, the adhesion mechanism of the adhesive used for forming the adhesive layer 2 is not particularly limited, and may be any of a chemical reaction type, a solvent volatilization type, a heat melting type, a thermal pressure type and the like.

Specific examples of the adhesive component that can be used to form the adhesive layer 2 include polyester resins such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, polycarbonate, and copolymerized polyester; Polyether-based adhesives; Polyethylene-based adhesives; Epoxy resins; Phenolic resin-based resins; Polyolefin-based resins such as nylon 6, nylon 66, nylon 12, and copolymerized polyamides; polyolefins, carboxylic acid-modified polyolefins, metal-modified polyolefins, etc. Polyolefin-based resin, Polyvinyl acetate-based resin; Cellulous adhesive; (Meta) acrylic-based resin; Polyolefin-based resin; Amino resin such as urea resin and melamine resin; Rubber such as chloroprene rubber, nitrile rubber, styrene-butadiene rubber; Examples include silicone-based resins. These adhesive components may be used alone or in combination of two or more. Among these adhesive components, a polyurethane-based adhesive is preferable.

The thickness of the adhesive layer 2 is not particularly limited as long as it functions as an adhesive layer, and examples thereof include 1 μm to 10 μm, preferably 2 μm to 5 μm.

[Metal layer 3]
In the battery packaging material 10, the metal layer 3 is a layer that functions as a barrier layer for improving the strength of the battery packaging material and preventing water vapor, oxygen, light, and the like from entering the battery. Specific examples of the metal constituting the metal layer 3 include aluminum, stainless steel, titanium, and the like, preferably aluminum. The metal layer 3 can be formed by a metal foil, metal vapor deposition, or the like, and is preferably formed of a metal foil, more preferably of an aluminum alloy foil. From the viewpoint of preventing the formation of wrinkles and pinholes in the metal layer 3 during the manufacture of packaging materials for batteries, for example, annealed aluminum (JIS H4160: 1994 A8021HO, JIS H4160: 1994 A8079H-O) , JIS H4000: 2014 A8021P-O, JIS H4000: 2014 A8079P-O) and the like, more preferably formed of a soft aluminum foil.

From the viewpoint of improving the moldability of the metal layer 3, the average crystal grain size of the metal layer 3 (particularly when it is formed of an aluminum alloy foil) is preferably 10.0 μm or less, and 1.0 μm to 7. It is preferably 0 μm, more preferably 1.0 μm to 3.0 μm.

In the present invention, the average crystal grain size of the aluminum alloy foil layer is determined by observing a cross section of the aluminum alloy foil layer in the thickness direction with a scanning electron microscope (SEM), and 100 aluminum alloy crystal grains located in the field of view 31. As shown in the schematic view of FIG. 4, the leftmost end in the direction perpendicular to the thickness direction of each crystal grain (thickness direction of the aluminum alloy foil layer) and the rightmost end in the direction perpendicular to the thickness direction. When the linear distance to be connected is the maximum diameter x, it means the average value of the maximum diameter x of 100 crystal grains. Since FIG. 4 is a schematic diagram, drawing is omitted and 100 crystal grains 31 are not drawn.

Further, in the present invention, in the cross section in the thickness direction of the laminate constituting the packaging material for a battery, in any 100 second-phase particles 32 in the field of view where the metal layer 3 is observed with an optical microscope, the individual first. The diameter y is large when the linear distance connecting the leftmost end in the vertical direction with respect to the thickness direction of the two-phase particles (thickness direction of the laminated body) and the rightmost end in the direction perpendicular to the thickness direction is the diameter y. The average diameter y of the top 20 second-phase particles in this order is preferably 5.0 μm or less, more preferably 1.0 μm to 4.0 μm, and 1.0 μm to 2.0 μm. Is even more preferable. When the average crystal grain size of the metal layer 3 is 10.0 μm or less and the diameter of the second phase particles 32 is in such a range, the moldability of the battery packaging material can be further improved. it can. Since FIG. 4 is a schematic diagram, drawing is omitted, and 100 second-phase particles 32 are not drawn.

In the present invention, for example, when the metal layer 3 is formed of an aluminum alloy, the second phase particles contained in the aluminum alloy form an intermetallic compound such as Al- (Fe · Mn) -Si, and are mainly formed. Such second-phase particles generated during solidification in the casting process cannot be immobilized in the subsequent process and remain.

When the cross section of the metal layer 3 in the thickness direction is observed with a scanning electron microscope (SEM), the crystal grains usually draw a boundary line in contact with a plurality of crystals. In contrast, second-phase particles usually have a single boundary. Further, since the crystal grains and the second phase particles have different phases, the colors are different on the SEM image, and the second phase particles often appear white. Further, when the cross section of the metal layer 3 in the thickness direction is observed with an optical microscope, it is easy to observe because only the second phase particles appear black due to the difference in phase between the crystal grains and the second phase particles. become.

When the metal layer 3 is formed of an aluminum alloy, the composition of the aluminum alloy is 0.7% by mass to 2.5% by mass of Fe, 0.05% by mass or less of Cu, and 0.30% by mass or less. It preferably contains Si.

As described above, in recent years, with the demand for miniaturization and thinning of batteries, further thinning of the packaging material for batteries is required. Along with this, the thickness of the metal layer laminated on the battery packaging material is also required to be further reduced. In the present invention, excellent moldability can be exhibited even when the thickness of the metal layer is set as very thin, for example, 50 μm or less, 40 μm or less, 35 μm or less, 30 μm or less, and further 25 μm or less. Further, excellent moldability can be exhibited even when the thickness of the entire packaging material for a battery is set to be very thin, for example, 105 μm or less, further 100 μm or less, further 90 μm or less, and further 80 μm or less. ..

In the present invention, the thickness of the metal layer 3 is preferably 10 μm to 30 μm, more preferably 10 μm to 30 μm, from the viewpoint of exhibiting excellent moldability while further reducing the thickness of the battery packaging material to increase the energy density of the battery. Is 10 μm to 25 μm, particularly preferably 10 μm to 20 μm.

Further, the metal layer 3 preferably has an undercoat layer on at least one surface, preferably both sides, in order to stabilize adhesion, prevent dissolution and corrosion, and the like. Here, the base film layer is a layer formed by subjecting the surface of the metal layer to a chemical conversion treatment, and the chemical conversion treatment refers to a process of forming an acid-resistant film on the surface of the metal layer. As the chemical conversion treatment, for example, chromate chromate using a chromium acid compound such as chromium nitrate, chromium fluoride, chromium sulfate, chromium acetate, chromium oxalate, chromium bicarbonate, acetylacetate chromate, chromium chloride, and chromium potassium sulfate. Treatment; Chromate phosphate treatment using a phosphoric acid compound such as sodium phosphate, potassium phosphate, ammonium phosphate, polyphosphate; aminoated phenol having repeating units represented by the following general formulas (1) to (4) Chromate treatment using a polymer and the like can be mentioned. In the aminated phenol polymer, the repeating units represented by the following general formulas (1) to (4) may be contained alone or in any combination of two or more. May be good.

In the general formulas (1) to (4), X represents a hydrogen atom, a hydroxyl group, an alkyl group, a hydroxyalkyl group, an allyl group or a benzyl group. Further, R ¹ and R ² represent a hydroxyl group, an alkyl group, or a hydroxyalkyl group, respectively, which are the same or different. In the general formulas (1) to (4), examples of the alkyl group represented by X, R ¹ and R ² include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group and an isobutyl group. Examples thereof include linear or branched alkyl groups having 1 to 4 carbon atoms such as tert-butyl groups. Examples of the hydroxyalkyl groups represented by X, R ¹ and R ² include hydroxymethyl groups, 1-hydroxyethyl groups, 2-hydroxyethyl groups, 1-hydroxypropyl groups, 2-hydroxypropyl groups and 3-. A linear or branched chain having 1 to 4 carbon atoms in which one hydroxy group such as a hydroxypropyl group, a 1-hydroxybutyl group, a 2-hydroxybutyl group, a 3-hydroxybutyl group, or a 4-hydroxybutyl group is substituted. Alkyl groups can be mentioned. In the general formulas (1) to (4), the alkyl group and the hydroxyalkyl group represented by X, R ¹ and R ² may be the same or different, respectively. In the general formulas (1) to (4), X is preferably a hydrogen atom, a hydroxyl group or a hydroxyalkyl group. The number average molecular weight of the aminated phenol polymer having the repeating unit represented by the general formulas (1) to (4) is preferably, for example, 5 to 1,000,000, and more preferably 1,000 to 20,000. ..

Further, as a chemical conversion treatment method for imparting corrosion resistance to the metal layer 3, a material obtained by dispersing metal oxides such as aluminum oxide, titanium oxide, cerium oxide and tin oxide and fine particles of barium sulfate is coated in phosphoric acid. A method of forming a corrosion-resistant undercoat layer on the surface of the metal layer 3 by performing a baking treatment at 150 ° C. or higher can be mentioned. Further, a resin layer obtained by cross-linking the cationic polymer with a cross-linking agent may be further formed on the corrosion-resistant base film layer. Here, examples of the cationic polymer include polyethyleneimine, an ionic polymer complex composed of polyethyleneimine and a polymer having a carboxylic acid, a primary amine graft acrylic resin obtained by graft-polymerizing a primary amine on an acrylic main skeleton, and polyallylamine. Alternatively, a derivative thereof, aminophenol and the like can be mentioned. As these cationic polymers, only one kind may be used, or two or more kinds may be used in combination. In addition, examples of the cross-linking agent include a compound having at least one functional group selected from the group consisting of an isocyanate group, a glycidyl group, a carboxyl group, and an oxazoline group, a silane coupling agent, and the like. As these cross-linking agents, only one type may be used, or two or more types may be used in combination.

As the chemical conversion treatment, only one type of chemical conversion treatment may be performed, or two or more types of chemical conversion treatments may be combined. Further, these chemical conversion treatments may be carried out by using one kind of compound alone or by using two or more kinds of compounds in combination. Among the chemical conversion treatments, chromate chromate treatment and chromate treatment in which a chromic acid compound, a phosphoric acid compound, and an amination phenol polymer are combined are preferable.

The amount of the undercoat layer formed on the surface of the metal layer 3 in the chemical conversion treatment is not particularly limited, but for example, in the case of performing the above chromate treatment, the chromic acid compound is contained per 1 m ² of the surface of the metal layer 3. About 0.5 mg to about 50 mg in terms of chromium, preferably about 1.0 mg to about 40 mg, the phosphorus compound is about 0.5 mg to about 50 mg in terms of phosphorus, preferably about 1.0 mg to about 40 mg, and the weight of aminoated phenol. It is desirable that the coalescence is contained in a proportion of about 1 mg to about 200 mg, preferably about 5.0 mg to 150 mg.

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

[Thermosetting resin layer 4]
In the battery packaging material of the present invention, the thermosetting resin layer 4 corresponds to the innermost layer, and is a layer in which the thermosetting resin layers are heat-sealed to seal the battery element when the battery is assembled.

The resin component used in the heat-fusing resin layer 4 is not particularly limited as long as it can be heat-fused, and examples thereof include polyolefins, cyclic polyolefins, carboxylic acid-modified polyolefins, and carboxylic acid-modified cyclic polyolefins. Be done.

Specific examples of the polyolefin include low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, and other polyethylene; homopolypropylene, polypropylene block copolymers (for example, propylene and ethylene block copolymers), and polypropylene. Polypropylenes such as random copolymers of propylene and ethylene (eg, random copolymers of propylene and ethylene); ethylene-butene-propylene tarpolymers; and the like. Among these polyolefins, polyethylene and polypropylene are preferable.

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

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

The carboxylic acid-modified cyclic polyolefin means that a part of the monomer constituting the cyclic polyolefin is copolymerized in place of α, β-unsaturated carboxylic acid or its anhydride, or α, β with respect to the cyclic polyolefin. -A polymer obtained by block-polymerizing or graft-polymerizing an unsaturated carboxylic acid or an anhydride thereof. The same applies to the cyclic polyolefin modified with carboxylic acid. In addition, examples of the carboxylic acid used for modification include those mentioned above.

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

The thermosetting resin layer 4 may be formed by one kind of resin component alone, or may be formed by a blend polymer in which two or more kinds of resin components are combined. Further, the thermosetting resin layer 4 may be formed of only one layer, or may be formed of two or more layers with the same or different resin components.

Further, the thermosetting resin layer 4 may contain a lubricant or the like, if necessary. When the heat-sealing resin layer 4 contains a lubricant, the moldability of the battery packaging material can be improved. The lubricant is not particularly limited, and a known lubricant can be used, and examples thereof include those exemplified in the above-mentioned base material layer 1. The lubricant may be used alone or in combination of two or more. The amount of the lubricant present on the surface of the heat-sealing resin layer 4 is not particularly limited, and from the viewpoint of improving the moldability of the material for electronic packaging, it is preferably 10 mg / m at a temperature of 24 ° C. and a humidity of 60%. ^{2 ~50mg} / m ^2, more preferably include ^{15mg / m 2 ~40mg / m 2} .

The thickness of the thermosetting resin layer 4 is not particularly limited as long as it exhibits the function as the thermosetting resin layer, but is preferably 60 μm or less, more preferably 15 μm to 40 μm. The heat-weldable resin layer can be formed by, for example, extrusion molding of a resin, heat welding of a resin film, adhesion of a resin film by a dry laminating method, or the like.

[Adhesive layer 5]
In the packaging material for batteries of the present invention, the adhesive layer 5 is a layer provided between the metal layer 3 and the thermosetting resin layer 4 as necessary in order to firmly bond the metal layer 3 and the thermosetting resin layer 4.

The adhesive layer 5 is formed of a resin capable of adhering the metal layer 3 and the thermosetting resin layer 4 to each other. The resin used for forming the adhesive layer 5 is not particularly limited in its adhesive mechanism, type of adhesive component, etc., and may be a two-component curable adhesive or a one-component curable adhesive. You may. Further, a polyolefin-based resin, a cured product of a resin composition containing an acid-modified polyolefin and a curing agent, and the like can also be used for forming the adhesive layer 5.

As the two-component curable adhesive and the one-component curable adhesive adhesive, for example, the same adhesives as those exemplified in the adhesive layer 2 can be used.

Examples of the polyolefin-based resin include the polyolefins, cyclic polyolefins, carboxylic acid-modified polyolefins, and carboxylic acid-modified cyclic polyolefins exemplified in the above-mentioned heat-sealing resin layer 4. Among these, carboxylic acid-modified polyolefin is preferable, and carboxylic acid-modified polypropylene is particularly preferable as the polyolefin from the viewpoint of excellent adhesion between the metal layer 3 and the heat-sealing resin layer 4.

Further, in the cured product of the resin composition containing the acid-modified polyolefin and the curing agent, the acid-modified polyolefin is preferably the same as the carboxylic acid-modified polyolefin and the carboxylic acid-modified cyclic polyolefin exemplified in the heat-sealing resin layer 4. It can be exemplified. The curing agent is not particularly limited as long as it cures the acid-modified polyolefin. Examples of the curing agent include an epoxy-based curing agent, a polyfunctional isocyanate-based curing agent, a carbodiimide-based curing agent, and an oxazoline-based curing agent.

The epoxy-based curing agent is not particularly limited as long as it is a compound having at least one epoxy group. Examples of the epoxy-based curing agent include epoxy resins such as bisphenol A diglycidyl ether, modified bisphenol A diglycidyl ether, novolak glycidyl ether, glycerin polyglycidyl ether, and polyglycerin polyglycidyl ether.

The polyfunctional isocyanate-based curing agent is not particularly limited as long as it is a compound having two or more isocyanate groups. Specific examples of the polyfunctional isocyanate-based curing agent include isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), and those obtained by polymerizing or nurate these. Examples thereof include a mixture and a copolymer with another polymer.

The carbodiimide-based curing agent is not particularly limited as long as it is a compound having at least one carbodiimide group (-N = C = N-). As the carbodiimide-based curing agent, a polycarbodiimide compound having at least two or more carbodiimide groups is preferable.

The oxazoline-based curing agent is not particularly limited as long as it is a compound having an oxazoline skeleton. Specific examples of the oxazoline-based curing agent include the Epocross series manufactured by Nippon Shokubai Co., Ltd.

The curing agent may be composed of two or more kinds of compounds from the viewpoint of enhancing the adhesion between the metal layer 3 and the thermosetting resin layer 4 by the adhesive layer 5.

The content of the curing agent in the resin composition forming the adhesive layer 5 is preferably in the range of 0.1% by mass to 50% by mass, and more preferably in the range of 0.1% by mass to 30% by mass. It is preferably in the range of 0.1% by mass to 10% by mass, more preferably.

The thickness of the adhesive layer 5 is not particularly limited as long as it functions as an adhesive layer, but when the adhesive exemplified in the adhesive layer 2 is used, it is preferably 2 μm to 10 μm, more preferably 2 μm to 5 μm. Can be mentioned. When the resin exemplified in the thermosetting resin layer 4 is used, it is preferably 2 μm to 50 μm, more preferably 10 μm to 40 μm. In the case of a cured product of the acid-modified polyolefin and the curing agent, it is preferably 30 μm or less, more preferably 0.1 μm to 20 μm, and further preferably 0.5 μm to 5 μm. When the adhesive layer 5 is a cured product of a resin composition containing an acid-modified polyolefin and a curing agent, the adhesive layer 5 can be formed by applying the resin composition and curing it by heating or the like.

[Surface coating layer]
In the packaging material for a battery of the present invention, for the purpose of improving designability, electrolytic solution resistance, scratch resistance, moldability, etc., if necessary, on the base material layer 1 (the metal layer of the base material layer 1). A surface coating layer (not shown) may be provided on the side opposite to 3), if necessary. The surface coating layer is a layer located at the outermost layer when the battery is assembled.

The surface coating layer can be formed of, for example, polyvinylidene chloride, polyester resin, urethane resin, acrylic resin, epoxy resin, or the like. Among these, the surface coating layer is preferably formed of a two-component curable resin. Examples of the two-component curable resin forming the surface coating layer include a two-component curable urethane resin, a two-component curable polyester resin, and a two-component curable epoxy resin. Moreover, you may mix the matting agent in the surface coating layer.

Examples of the matting agent include fine particles having a particle size of 0.5 nm to 5 μm. The material of the matting agent is not particularly limited, and examples thereof include metals, metal oxides, inorganic substances, and organic substances. The shape of the matting agent is also not particularly limited, and examples thereof include a spherical shape, a fibrous shape, a plate shape, an amorphous shape, and a balloon shape. Specific examples of the matting agent include talc, silica, graphite, kaolin, montmoriloid, montmorillonite, synthetic mica, hydrotalcite, silica gel, zeolite, aluminum hydroxide, magnesium hydroxide, zinc oxide, magnesium oxide, and aluminum oxide. , Neodium oxide, Antimon oxide, Titanium oxide, Cerium oxide, Calcium sulfate, Barium sulfate, Calcium carbonate, Calcium silicate, Lithium carbonate, Calcium benzoate, Calcium silicate, Magnesium stearate, Alumina, Carbon black, Carbon nanotubes, Examples thereof include refractory nylon, crosslinked acrylic, crosslinked styrene, crosslinked polyethylene, benzoguanamine, gold, aluminum, copper and nickel. These matting agents may be used alone or in combination of two or more. Among these matting agents, preferably silica, barium sulfate, and titanium oxide are mentioned from the viewpoint of dispersion stability and cost. Further, the matting agent may be subjected to various surface treatments such as an insulating treatment and a highly dispersible treatment on the surface.

The method for forming the surface coating layer is not particularly limited, and examples thereof include a method of applying a two-component curable resin for forming the surface coating layer on one surface of the base material layer 1. When the matting agent is blended, the matting agent may be added to the two-component curable resin, mixed, and then applied.

The content of the matting agent in the surface coating layer is not particularly limited, but is preferably about 1% by mass to 50% by mass, and more preferably about 1% by mass to 40% by mass.

The thickness of the surface coating layer is not particularly limited as long as the packaging material for the battery satisfies the above physical properties while exhibiting the above functions as the surface coating layer. For example, 0.5 μm to 10 μm, preferably 1 μm to 5 μm. Can be mentioned.

3. 3. The preparation method of a battery packaging material of the production method the present invention for a battery packaging material, as long as the laminate as a laminate of layers having a predetermined composition can be obtained is not particularly limited, at least, the base layer 1, a metal layer 3 and the thermosetting resin layer 4 are laminated in this order to obtain a laminated body, and the base material layer 1 has a thickness of 60% or more of the thickness of the metal layer 3. The manufacturing method using the above can be adopted. That is, by using the base material layer 1 described in the column of "2. Composition of each layer forming the battery packaging material" as the base material layer 1 and laminating each layer, the battery packaging material of the present invention can be obtained. Can be manufactured.

An example of the method for producing the packaging material for a battery of the present invention is as follows. First, a laminate (hereinafter, may be referred to as "laminate A") in which a base material layer 1, an adhesive layer 2 provided as needed, and a metal layer 3 are laminated in this order is formed. Specifically, the laminated body A is formed by applying an adhesive used for forming the adhesive layer 2 on the base material layer 1 or, if necessary, on the metal layer 3 whose surface has been chemically converted, by a gravure coating method. It can be carried out by a dry laminating method in which the metal layer 3 or the base material layer 1 is laminated and the adhesive layer 2 is cured after being coated and dried by a coating method such as a roll coating method.

Next, the thermosetting resin layer 4 is laminated on the metal layer 3 of the laminated body A. When the thermosetting resin layer 4 is directly laminated on the metal layer 3, the resin components constituting the thermosetting resin layer 4 are coated on the metal layer 3 of the laminated body A by a gravure coating method or a roll coating method. It may be applied by a method such as. When the adhesive layer 5 is provided between the metal layer 3 and the thermosetting resin layer 4, for example, (1) the adhesive layer 5 and the thermosetting resin layer are placed on the metal layer 3 of the laminate A. A method of laminating 4 by co-extruding (co-extrusion laminating method), (2) Separately, a laminated body in which the adhesive layer 5 and the thermosetting resin layer 4 are laminated is formed, and this is used as the metal layer of the laminated body A. By a method of laminating on 3 by a thermal laminating method, (3) an adhesive for forming an adhesive layer 5 on the metal layer 3 of the laminated body A by an extrusion method, a solution coating method, drying at a high temperature, and a baking method. A method of laminating a thermosetting resin layer 4 which has been laminated and previously formed into a sheet on the adhesive layer 5 by a thermal laminating method. (4) A sheet-like film is formed in advance with the metal layer 3 of the laminated body A. A method of laminating the laminate A and the thermosetting resin layer 4 via the adhesive layer 5 while pouring the melted adhesive layer 5 between the thermosetting resin layer 4 (sandwich laminating method) and the like. Can be mentioned.

When the surface coating layer is provided, the surface coating layer is laminated on the surface of the base material layer 1 opposite to the metal layer 3. The surface coating layer can be formed, for example, by applying the above resin for forming the surface coating layer to the surface of the base material layer 1. The order of the step of laminating the metal layer 3 on the surface of the base material layer 1 and the step of laminating the surface coating layer on the surface of the base material layer 1 is not particularly limited. For example, after forming the surface coating layer on the surface of the base material layer 1, the metal layer 3 may be formed on the surface of the base material layer 1 opposite to the surface coating layer.

As described above, a surface coating layer provided as needed / a base material layer 1 / an adhesive layer provided as needed 2 / a metal layer whose surface is chemically treated as needed 3 / as needed A laminate composed of the provided adhesive layer 5 / thermosetting resin layer 4 is formed, but in order to strengthen the adhesiveness of the adhesive layer 2 and the adhesive layer 5 provided as needed, heat is further added. It may be subjected to heat treatment such as roll contact type, hot air type, near or far infrared type. Examples of the conditions for such heat treatment include 1 minute to 5 minutes at 150 ° C. to 250 ° C.

In the packaging material for batteries of the present invention, each layer constituting the laminated body improves or stabilizes film forming property, laminating process, aptitude for secondary processing (pouching, embossing) of the final product, etc., if necessary. Therefore, surface activation treatment such as corona treatment, blast treatment, oxidation treatment, and ozone treatment may be performed.

4. Applications of Battery Packaging Materials The battery packaging materials of the present invention are used for packaging for sealing and accommodating battery elements such as positive electrodes, negative electrodes, and electrolytes. That is, a battery element having at least a positive electrode, a negative electrode, and an electrolyte can be housed in a package formed of the packaging material for a battery of the present invention to form a battery.

Specifically, a battery element having at least a positive electrode, a negative electrode, and an electrolyte is used in the battery packaging material of the present invention, with metal terminals connected to each of the positive electrode and the negative electrode projecting outward. A battery is formed by covering the peripheral edge of an element so that a flange portion (a region where the heat-sealing resin layers come into contact with each other) can be formed, and heat-sealing and sealing the heat-sealing resin layers of the flange portion. Batteries using packaging materials for use are provided. When the battery element is housed in the package formed of the battery packaging material of the present invention, the heat-sealing resin portion of the battery packaging material of the present invention is on the inside (the surface in contact with the battery element). To form a package.

The packaging material for a battery of the present invention may be used for either a primary battery or a secondary battery, but is preferably a secondary battery. The type of secondary battery to which the packaging material for a battery of the present invention is applied is not particularly limited, and for example, a lithium ion battery, a lithium ion polymer battery, a lead livestock battery, a nickel / hydrogen livestock battery, and a nickel / cadmium livestock battery. , Nickel / iron livestock battery, nickel / zinc livestock battery, silver oxide / zinc livestock battery, metal air battery, polyvalent cation battery, condenser, capacitor and the like. Among these secondary batteries, lithium ion batteries and lithium ion polymer batteries can be mentioned as suitable application targets of the packaging material for batteries of the present invention.

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

(Examples 1-30 and Comparative Examples 1-12)
<Manufacturing of packaging materials for batteries>
An aluminum alloy foil as a metal layer was laminated on the base material layer by a dry laminating method so as to have the resin and thickness shown in Table 1. Specifically, a two-component urethane adhesive (polyol compound and aromatic isocyanate compound) was applied to one surface of the aluminum alloy foil to form an adhesive layer (thickness 3 μm) on the aluminum alloy foil. Next, the adhesive layer and the base material layer on the metal layer are laminated by a dry laminating method, and then an aging treatment is performed at 40 ° C. for 24 hours to form a laminate of the base material layer / adhesive layer / metal layer. Made. Both sides of the aluminum alloy foil were subjected to chemical conversion treatment. The chemical conversion treatment of the aluminum alloy foil is performed by a roll coating method on both sides of the aluminum foil so that the coating amount of chromium is 10 mg / m ² (dry mass) in a treatment liquid composed of phenol resin, chromium fluoride compound, and phosphoric acid. It was applied to and baked for 20 seconds under the condition that the film temperature was 180 ° C. or higher.

Next, in Examples 1 to 20, 23 to 30 and Comparative Examples 1 to 8 and 10 to 12, an adhesive layer (thickness 10 μm) and heat fusion were performed on the metal layer of each of the above-mentioned laminates. By melt-coextruding the resin (PPa, PP or PE) shown in Table 1 as the sex resin layer (thickness 10 μm), the adhesive layer and the thermosetting resin layer are laminated on the metal layer, and the base material layer / A packaging material for a battery was obtained in which an adhesive layer / a metal layer / an adhesive layer / a thermosetting resin layer were laminated in this order. Further, in Examples 21 and 22 and Comparative Example 9, an adhesive layer (PPa, thickness 10 μm) is laminated on the metal layer, and a non-stretched polypropylene film (CPP, thickness 25 μm) is used as a thermosetting resin layer on the adhesive layer (PPa, thickness 10 μm). ) Was laminated to obtain a packaging material for a battery in which a base material layer / adhesive layer / metal layer / adhesive layer / thermosetting resin layer were laminated in this order. The surface of each base material layer was coated with erucic acid amide as a lubricant so that the abundance amount was 7.0 mg / m ^{2 at} a temperature of 24 ° C. and a humidity of 60 ° C.

Table 1 shows whether the aluminum alloy foils used in each Example and Comparative Example have the above-mentioned average crystal grain size of 10 μm or less or more than 10 μm. The method for measuring the average crystal grain size is as described above.

<Evaluation of moldability>
A sample was prepared by cutting each of the battery packaging materials obtained above into a rectangle of 80 mm × 120 mm square. Next, using a molding die having a diameter of 30 mm × 50 mm, molding is performed by increasing the molding depth in 0.5 mm increments from the molding depth of 0.5 mm at a pressing pressure of 0.4 MPa to obtain an aluminum alloy foil. The molding depth was increased until the pinholes were open. As the molding die, a molding die having a diameter of 29.4 mm × 49.4 mm was used. The female mold of the molding die has a corner R2.3, and its surface is Rz specified in "JIS B 0659-1: 2002 Annex 1 (Reference) Table 2 of Surface Roughness Standard Piece for Comparison". (Maximum height roughness) is 3.2 μm. On the other hand, the surface of the male type of the corner R2 corresponding to the female type is Rz (maximum height) specified in "JIS B 0659-1: 2002 Annex 1 (Reference) Table 2 of Surface Roughness Standard Piece for Comparison". Roughness) is 1.6 μm. The clearance between the female type and the male type is 0.3 mm. Further, a depth 0.5 mm shallower than the molding depth when the pinhole was opened was defined as the limit molding depth of the sample. From this limit molding depth, the thickness of the metal layer and the limit molding depth in each of the examples and the comparative examples having the same composition of the base material layer and the thermosetting resin layer are compared. Was used as a reference value, and the moldability of the packaging material for batteries was scored according to the following criteria. The results are shown in Table 1.

10: The limit molding depth is 2.0 mm or more deeper than the reference comparative example 9: The limit molding depth is 1.8 mm or more and less than 2.0 mm deeper than the reference comparative example 8: Reference comparison The limit molding depth is 1.6 mm or more and less than 1.8 mm deeper than the example 7: The limit molding depth is 1.4 mm or more and less than 1.6 mm deeper than the reference comparative example 6: From the reference comparative example Also, the limit molding depth is 1.2 mm or more and less than 1.4 mm deeper 5: than the standard comparative example, and the limit molding depth is 1.0 mm or more and less than 1.2 mm deeper 4: than the standard comparative example. Limit molding depth is 0.8 mm or more and less than 1.0 mm deeper 3: Limit molding depth is 0.6 mm or more and less than 0.8 mm deeper than the standard comparative example 2: Limit molding is deeper than the standard comparative example Depth is 0.4 mm or more and less than 0.6 mm deep 1: Limit molding depth is 0.2 mm or more and less than 0.4 mm deeper than the standard comparative example

In Table 1, ONy is biaxially stretched nylon, PET is biaxially stretched polyethylene terephthalate, and PBT is biaxially stretched polybutylene terephthalate film. ONy / ONy is a two-layer laminate of nylon film. PET / ONy is a two-layer laminate of a polyethylene terephthalate film and a nylon film, and ONy is located on the metal layer side. Each layer of these laminates is bonded with a two-component urethane adhesive of 3 μm. The thickness of the base material layer does not include the thickness of the adhesive. PP means random polypropylene, PE means high-density polyethylene, CPP means unstretched polypropylene film, and PPa means maleic anhydride-modified polypropylene.

As is clear from the results shown in Table 1, in the examples in which the thickness of the base material layer is 60% or more of the thickness of the metal layer, the thinner the thickness of the battery packaging material, the more the reference comparative example. However, it can be seen that the degree to which the critical molding depth becomes deeper increases.

For example, when Example 17 using a metal layer having a thickness of 50 μm and Comparative Example 7 are compared, the moldability of Example 17 is "3: Reference" as compared with Comparative Example 7, which is a reference. The limit molding depth is 0.6 mm or more and less than 0.8 mm deeper than in the comparative example. "

Further, for example, when Example 11 using a metal layer having a thickness of 30 μm and Comparative Example 4 are compared, the moldability of Example 11 is higher than that of Comparative Example 4, which is a reference. The limit molding depth is 1.2 mm or more and less than 1.4 mm deeper than that of the comparative example. "

Further, for example, when Examples 5 and 6 using a metal layer having a thickness of 20 μm and Comparative Example 2 are compared, the moldability of Examples 5 and 6 is higher than that of Comparative Example 2 as a reference. "8: The limit molding depth is 1.6 mm or more and less than 1.8 mm deeper than the reference comparative example" or "10: The limit molding depth is 2.0 mm or more deeper than the reference comparative example" The result was.

As described above, in the present invention, as the thickness of the metal layer becomes as thin as 50 μm, 30 μm, 20 μm, and 15 μm, the effect of setting the thickness of the base material layer to 60% or more of the thickness of the metal layer becomes more remarkable. I understand. Such a phenomenon has not been known at all in the past.

1 Base material layer 2 Adhesive layer 3 Metal layer 4 Thermosetting resin layer 5 Adhesive layer

Claims (4)

It is composed of a laminate having at least a base material layer, a metal layer, and a thermosetting resin layer in this order.
The base material layer is made of a nylon film having a thickness of 10 μm or more and 20 μm or less.
The metal layer is made of an aluminum alloy foil having a thickness of 15 μm or more and 20 μm or less.
The thickness of the laminate is 90 μm or less.
The thickness of the base material layer is 70% or more and 100% or less of the thickness of the metal layer.
Packaging material for batteries. The packaging material for a battery according to claim 1 , wherein a lubricant is present on the surface of the base material layer. A battery in which a battery element including at least a positive electrode, a negative electrode, and an electrolyte is housed in a package formed of the battery packaging material according to claim 1 or 2. At least, it includes a step of laminating the base material layer, the metal layer, and the thermosetting resin layer in this order to obtain a laminate.
The base material layer is made of a nylon film having a thickness of 10 μm or more and 20 μm or less.
The metal layer is made of an aluminum alloy foil having a thickness of 15 μm or more and 20 μm or less.
The thickness of the laminate is 90 μm or less.
A method for producing a packaging material for a battery, wherein the base material layer has a thickness of 70% or more and 100% or less of the thickness of the metal layer.