JP6844118B2 - Battery packaging materials and batteries - Google Patents

Description

The present invention relates to battery packaging materials and batteries.

Conventionally, various types of batteries have been developed. In these batteries, the battery element composed of electrodes, electrolytes, etc. needs to be sealed with a packaging material or the like. As a packaging material for batteries, a metal packaging material is often used.

In recent years, with the improvement of high performance of electric vehicles, hybrid electric vehicles, personal computers, cameras, mobile phones, etc., batteries having various shapes are required. Batteries are also required to be thinner and lighter. However, it is difficult to keep up with the diversification of battery shapes with the metal packaging materials that have been widely used in the past. Moreover, since it is made of metal, there is a limit to the weight reduction of the packaging material.

Therefore, 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 layer / metal layer / thermosetting resin layer is sequentially laminated is used. Proposed.

For example, Patent Document 1 discloses a packaging material for a lithium ion battery in which a first adhesive layer, an aluminum foil layer, a second adhesive layer, and a base material layer are sequentially laminated on one surface of a sealant layer. There is.

Japanese Unexamined Patent Publication No. 2011-76735

However, when a battery packaging material as disclosed in Patent Document 1 is applied to a battery, the insulating property may decrease. Specifically, in the battery manufacturing process, minute foreign substances such as electrode active material and electrode tab fragments may adhere to the surface of the heat-sealing resin layer, and the battery element is heated by the battery packaging material. Due to the heat and pressure during sealing, the portion of the heat-sealing resin layer to which foreign matter adheres may become thin. For example, if the thermosetting resin layer becomes thin in a portion where the thermosetting resin layers are heat-sealed with each other, the insulating property of the battery packaging material may be insufficient.

Further, minute foreign substances such as electrode active materials and fragments of electrode tabs have conductivity. When a conductive foreign substance is present between the electrode tab and the heat-sealing resin layer, the heat and pressure during heat sealing causes the foreign substance to penetrate the heat-sealing resin layer, and the electrode tab and the battery packaging material. There is a risk of short-circuiting due to electrical connection with the metal layer of.

Further, in recent years, there has been an increasing demand for miniaturization and thinning of batteries, and in order to meet the demands, further thinning of film-shaped packaging materials for batteries is required. For this reason, the thermosetting resin layer also tends to be thinner, and even when no foreign matter is present, the thermosetting resin layer becomes thinner during heat sealing, especially in the portion where the electrode tab is located. There is a problem that it is easy.

The present invention is an invention made in view of these problems. That is, in the present invention, for example, minute foreign matter such as an electrode active material or a fragment of an electrode tab is heat-sealed at an interface between heat-sealing resin layers or between an electrode tab and a heat-sealing resin layer. The main purpose is to provide a packaging material for a battery that can maintain high insulation even when it is present in such a part.

The present inventors have made diligent studies to solve the above problems. As a result, the logarithmic decrement ΔE1 at 80 ° C. in the rigid pendulum measurement is 0 in at least a packaging material for a battery composed of a laminate including a base material layer, a metal layer, an adhesive layer, and a thermosetting resin layer in this order. It has been found that by adopting an adhesive layer of .08 or less, it becomes a packaging material for a battery having excellent insulating properties. 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, an adhesive layer, and a thermosetting resin layer in this order.
The adhesive layer is a packaging material for a battery having a logarithmic decrement ΔE1 at 80 ° C. in a rigid pendulum measurement of 0.08 or less.
Item 2. Item 2. The packaging material for a battery according to Item 1, wherein the adhesive layer has a melting point of 140 ° C. or higher.
Item 3. Item 2. The packaging material for a battery according to Item 1 or 2, wherein the heat-sealing resin layer has a logarithmic decrement rate ΔE2 at 80 ° C. in a rigid pendulum measurement of 0.04 or more.
Item 4. Item 3. The packaging material for a battery according to Item 3, wherein the ratio (ΔE2 / ΔE1) of the logarithmic decrement rate ΔE1 to the logarithmic decrement rate ΔE2 is in the range of 0.5 or more and 4.0 or less.
Item 5. Item 2. The packaging material for a battery according to any one of Items 1 to 4, wherein the adhesive layer has a melt tension of 40 mN or more at 190 ° C.
Item 6. Item 2. The battery packaging material according to any one of Items 1 to 5, wherein the adhesive layer contains an acid-modified polyolefin.
Item 7. Item 2. The packaging material for a battery according to any one of Items 1 to 6, wherein the thermosetting resin layer contains polyolefin.
Item 8. Item 2. The battery packaging material according to any one of Items 1 to 7, wherein the metal layer is formed of aluminum foil.
Item 9. 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 8.

According to the present invention, in a battery packaging material composed of a laminate having at least a base material layer, a metal layer, an adhesive layer, and a thermosetting resin layer in this order, the adhesive layer is measured at 80 ° C. in a rigid pendulum measurement. When the logarithmic decrement ΔE1 is 0.08 or less, it is possible to provide a packaging material for a battery having excellent insulating properties.

It is a figure which shows an example of the cross-sectional structure of the packaging material for a battery of this invention. It is a figure which shows an example of the cross-sectional structure of the packaging material for a battery of this invention. It is a schematic diagram for demonstrating the method of "evaluation of insulation property against foreign matter biting" in an Example.

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, an adhesive layer, and a thermosetting resin layer in this order, and the adhesive layer is logarithmic at 80 ° C. in a rigid pendulum measurement. The attenuation factor ΔE1 is 0.08 or less. Hereinafter, the packaging material for a battery of the present invention will be described in detail.

1. 1. Laminated structure of battery packaging material In the battery packaging material of the present invention, for example, as shown in FIG. 1, at least a base material layer 1, a metal layer 2, an adhesive layer 3, and a thermosetting resin layer 4 are sequentially laminated. It consists of a laminated body. 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 the battery is assembled, 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, for example, the packaging material for a battery of the present invention has an adhesive layer 5 between the base material layer 1 and the metal layer 2 for the purpose of enhancing their adhesiveness, if necessary. May be. Further, although not shown, a surface coating layer or the like may be provided on the outside of the base material layer 1 (the side opposite to the thermosetting resin layer 4).

The total thickness of the laminate constituting the packaging material for a battery of the present invention is not particularly limited, but is preferably 160 μm or less from the viewpoint of exhibiting high insulation while making the total thickness of the laminate as thin as possible. , More preferably 35 μm or more and 155 μm or less, and further preferably 45 μm or more and 120 μm or less. According to the present invention, excellent insulating properties can be exhibited even when the thickness of the laminate constituting the packaging material for a battery of the present invention is as thin as 160 μm or less, for example. Therefore, the battery packaging material of the present invention can contribute to the improvement of the energy density of the battery.

2. 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. 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.

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 or the like 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.

Specific examples of the polyamide include an aliphatic polyamide such as nylon 6, nylon 66, nylon 610, nylon 12, nylon 46, and 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, polymethaki. 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 has excellent 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.

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 multi-layer structure in which a polyester film and a nylon film are laminated, a multi-layer structure in which a plurality of nylon films are laminated, and a multi-layer 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. For example, when the base material layer 1 is formed from two layers of resin films, the structure is such that the polyester resin and the polyester resin are laminated, the polyamide resin and the polyamide resin are laminated, or the polyester resin and the polyamide resin are laminated. Is preferable, and it is more preferable to have a structure in which polyethylene terephthalate and polyethylene terephthalate are laminated, a structure in which nylon and nylon are laminated, or a structure in which polyethylene terephthalate and nylon are laminated. 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 having biaxially stretched nylon and biaxially stretched polyester in this order from the side of the metal layer 2. When the base material layer 1 has a multilayer structure, the thickness of each layer is preferably 2 μm or more and 25 μm or less.

When the base material layer 1 has a multilayer structure, each resin film may be adhered via an adhesive, or may be directly laminated without an adhesive. In the case of adhering without using an adhesive, for example, a method of adhering in a hot-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 volatile 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, lauric acid amide, palmitylation phosphate amide, stearic acid amide, behenic acid amide, such as hydroxystearic acid amide. Specific examples of the unsaturated fatty acid amide include oleic acid amide and erucic acid amide. Specific examples of the substituted amide, N- Oreiruparu Michi phosphate amide, N- stearyl stearic acid amide, N- stearyl oleic acid amide, N- oleyl stearic acid amide, such as N- stearyl erucic acid amide. Further, specific examples of methylolamide include methylolstearic acid amide. Specific examples of saturated fatty acid bisamides 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 adipic acid 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 bisamides, m- xylylene bis stearic acid amide, m- xylylene bis hydroxy stearic acid amide, N, etc. N'- distearyl isophthalic 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 or more and 15 mg at a temperature of 24 ° C. and a humidity of 60%. / M ² or less, more preferably 5 mg / m ² or more and 14 mg / m ² or less.

The thickness of the base material layer 1 is preferably 4 μm or more, more preferably 10 μm or more and 75 μm or less, from the viewpoint of making the battery packaging material having excellent insulating properties while reducing the total thickness of the battery packaging material. More preferably, it is 10 μm or more and 50 μm or less.

[Adhesive layer 5]
In the packaging material for batteries of the present invention, the adhesive layer 5 is a layer provided between the base material layer 1 and the metal layer 2 as necessary in order to firmly bond the base material layer 1 and the metal layer 2.

The adhesive layer 5 is formed of an adhesive capable of adhering the base material layer 1 and the metal layer 2. The adhesive used to form the adhesive layer 5 may be a two-component curable adhesive or a one-component curable adhesive. Further, the adhesive mechanism used for forming the adhesive layer 5 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 5 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 resins; Polyamide-based resins such as nylon 6, nylon 66, nylon 12, and copolymerized polyamides; polyolefins such as polyolefins, carboxylic acid-modified polyolefins, and metal-modified polyolefins. Resins, polyvinyl acetate resins; cellulose adhesives; (meth) acrylic resins; polyimide resins; urea resins, melamine resins and other amino resins; chloroprene rubbers, nitrile rubbers, styrene-butadiene rubbers and other rubbers; silicones Examples include 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 5 is not particularly limited as long as it functions as an adhesive layer, and examples thereof include 1 μm or more and 10 μm or less, preferably 2 μm or more and 5 μm or less.

[Metal layer 2]
In the battery packaging material, the metal layer 2 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 2 include aluminum, stainless steel, titanium, and the like, preferably aluminum. The metal layer 2 can be formed by metal foil, metal vapor deposition, or the like, and is preferably formed of metal foil, and more preferably of aluminum foil. From the viewpoint of preventing the formation of wrinkles and pinholes in the metal layer 2 during the manufacture of battery packaging materials, 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.

The thickness of the metal layer 2 is not particularly limited as long as it functions as a barrier layer such as water vapor, but can be, for example, 10 μm or more and 100 μm or less, preferably 10 μm or more and 55 μm or less.

Further, the metal layer 2 is preferably subjected to chemical conversion treatment on at least one surface, preferably both sides, in order to stabilize adhesion, prevent dissolution and corrosion, and the like. Here, the chemical conversion treatment refers to a treatment for forming an acid-resistant film on the surface of a metal layer. As the chemical conversion treatment, for example, chromium 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 is used. Treatment; Chromic acid chromate treatment using a phosphoric acid compound such as sodium phosphate, potassium phosphate, ammonium phosphate, polyphosphate; aminoated phenol having a repeating unit 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 unit 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. In addition, 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 a linear or branched alkyl group having 1 to 4 carbon atoms such as a tert-butyl group. Examples of the hydroxyalkyl groups represented by X, R ¹ and R ² include a hydroxymethyl group, a 1-hydroxyethyl group, a 2-hydroxyethyl group, a 1-hydroxypropyl group, a 2-hydroxypropyl group 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. An alkyl group 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, for example, preferably 500 or more and 1 million or less, and preferably 1000 or more and 20,000 or less. More preferred.

Further, as a chemical conversion treatment method for imparting corrosion resistance to the metal layer 2, 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 treatment layer on the surface of the metal layer 2 by performing a baking treatment at 150 ° C. or higher can be mentioned. Further, a resin layer obtained by cross-linking a cationic polymer with a cross-linking agent may be further formed on the corrosion-resistant treatment 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. 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 acid-resistant film formed on the surface of the metal layer 2 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 2.} About 0.5 mg or more and about 50 mg or less in terms of chromium, preferably about 1.0 mg or more and about 40 mg or less, and about 0.5 mg or more and about 50 mg or less in terms of phosphorus, preferably about 1.0 mg or more and about 40 mg or less, and It is desirable that the amination phenol polymer is contained in a proportion of about 1 mg or more and about 200 mg or less, preferably about 5.0 mg or more and 150 mg or less.

In the chemical conversion treatment, a solution containing a compound used for forming an acid-resistant film is applied to the surface of the metal layer 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. It is carried out by heating so as to be ℃ or more and 200 ℃ or less. 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.

[Adhesive layer 3]
In the battery packaging material of the present invention, the adhesive layer 3 is provided between the metal layer 2 and the heat-sealing resin layer 4 in order to firmly bond the metal layer 2 and the heat-sealing resin layer 4 while enhancing the insulating property of the battery packaging material. It is a layer.

In the present invention, the adhesive layer 3 is characterized in that the logarithmic decrement ΔE1 at 80 ° C. in the rigid pendulum measurement is 0.08 or less. The logarithmic decrement at 80 ° C. in the rigid pendulum measurement is an index showing the hardness of the resin, and the smaller the logarithmic decrement, the higher the hardness of the resin. In the rigid pendulum measurement, the attenuation rate of the pendulum when the temperature of the resin is raised from a low temperature to a high temperature is measured. In the rigid pendulum measurement, generally, the edge portion is brought into contact with the surface of the object to be measured and the pendulum is moved in the left-right direction to give vibration to the object to be measured. In the present invention, as the temperature of the resin rises, the resin becomes softer, so that the attenuation rate of the pendulum increases. In the present invention, heat is generated by arranging a hard adhesive layer 3 having a logarithmic decrement of 0.08 or less at a relatively high temperature of 80 ° C. between the metal layer 2 and the thermosetting resin layer 4. Even when the thermosetting resin layer is thinned by the seal, high insulating properties can be exhibited. Conventionally, in a packaging material for a battery, a technique of arranging an adhesive layer between a metal layer and a thermosetting resin layer has been known. However, since a hard resin having a logarithmic decrement rate of 0.08 or less at 80 ° C. is not suitable for extrusion molding, such a hard adhesive layer has not been conventionally arranged. On the other hand, in the present invention, by arranging such a hard adhesive layer 3 between the metal layer 2 and the thermosetting resin layer 4, a packaging material for a battery having high insulating properties is obtained. Is possible.

The logarithmic reduction rate ΔE is calculated by the following formula.
ΔE = [ln (A1 / A2) + ln (A2 / A3) + ... + ln (An / An + 1)] / n
A: Amplitude n: Frequency

From the viewpoint of exhibiting excellent insulating properties while ensuring excellent adhesiveness between the metal layer 2 and the thermosetting resin layer 4, the logarithmic decrement rate ΔE1 of the adhesive layer 3 is preferably 0.02 or more. 0.07 or less can be mentioned.

In the present invention, a commercially available rigid pendulum physical characteristic tester is used, a cylindrical cylinder edge is used as an edge portion to be pressed against the adhesive layer 3, the initial amplitude is about 0.3 degree, and the temperature is raised in the temperature range of 30 ° C to 130 ° C. A rigid pendulum physical property test is performed on the adhesive layer 3 under the condition of a speed of 5 ° C./min. Then, based on the logarithmic decrement at 80 ° C., the standard of the insulating property exhibited by the adhesive layer 3 was set. The logarithmic decrement rate ΔE2 of the thermosetting resin layer 4, which will be described later, is also a value measured in the same manner.

The adhesive layer 3 is formed of a resin capable of adhering the metal layer 2 and the thermosetting resin layer 4 to each other. The resin used for forming the adhesive layer 3 is not particularly limited as long as it has the logarithmic decrement rate ΔE1 described above, but while ensuring excellent adhesiveness between the metal layer 2 and the thermosetting resin layer 4. From the viewpoint of exhibiting excellent insulating properties, acid-modified polyolefin can be mentioned. That is, in the present invention, the adhesive layer 3 preferably contains an acid-modified polyolefin.

The acid-modified polyolefin is not particularly limited, but preferred examples thereof include a carboxylic acid-modified polyolefin and a carboxylic acid-modified cyclic polyolefin exemplified in the heat-sealing resin layer 4 described later. Among the acid-modified polyolefins, carboxylic acid-modified polypropylene is particularly preferable from the viewpoint of exhibiting excellent insulating properties while ensuring excellent adhesiveness between the metal layer 2 and the heat-sealing resin layer 4.

Further, it is preferable that the adhesive layer 3 further contains a polyolefin or a cyclic polyolefin in addition to the acid-modified polyolefin. The polyolefin or cyclic polyolefin is not particularly limited, but preferably those exemplified in the thermosetting resin layer 4 described later. Among the polyolefins, polypropylene is particularly preferable from the viewpoint of exhibiting excellent insulating properties while ensuring excellent adhesiveness between the metal layer 2 and the thermosetting resin layer 4.

The adhesive layer 3 may be composed of one kind of resin component alone, or may be made of a blended polymer in which two or more kinds of resin components are combined. Further, the adhesive layer 3 may be composed of only one layer, or may be composed of two or more layers with the same or different resin components.

The logarithmic decrement ΔE1 at 80 ° C. in the rigid pendulum measurement of the adhesive layer 3 is, for example, the content of the resin contained in the adhesive layer 3, the melting point, the MFR, the number average molecular weight, the weight average molecular weight, the degree of dispersion, the Vicat softening point, and the like. Can be set to the above value by adjusting.

The melting point of the adhesive layer 3 is preferably 130 ° C. or higher, more preferably, from the viewpoint of exhibiting better insulating properties while ensuring better adhesiveness between the metal layer 2 and the thermosetting resin layer 4. Is 130 ° C. or higher and 165 ° C. or lower. The melting point of the adhesive layer 3 is a value measured using a differential scanning calorimeter (DSC). The melting point of the adhesive layer 3 can be measured with respect to the resin (for example, pellets) used to form the adhesive layer 3. Further, after the battery packaging material is formed, the adhesive layer 3 obtained from the battery packaging material can be measured.

Further, from the viewpoint of further improving the adhesiveness and insulating property between the metal layer 2 and the thermosetting resin layer 4, the melt tension of the adhesive layer 3 at 190 ° C. is preferably 40 mN or more, more preferably 40 mN or more and 80 mN. The following can be mentioned. The melt tension of the adhesive layer 3 at 190 ° C. is, for example, a value measured by the method described in Examples.

The MFR (230 ° C., load 2.16 kg) of the adhesive layer 3 is not particularly limited, but is preferably 4 g from the viewpoint of further improving the adhesiveness and insulating property between the metal layer 2 and the thermosetting resin layer 4. / 10 minutes or more and 10 g / 10 minutes or less can be mentioned. From the same viewpoint, the vicut softening point of the adhesive layer 3 is preferably 95 ° C. or higher and 105 ° C. or lower. From the same viewpoint, the number average molecular weight (Mn) of the resin constituting the adhesive layer 3 is preferably 61,000 or more and 65,000 or less, and the weight average molecular weight (Mw) is 350,000. The above is 410,000 or less, and the dispersity (Mw / Mn) is 6.0 or more and 7.0 or less.

The details of the mechanism by which the adhesiveness and the insulating property between the metal layer 2 and the thermosetting resin layer 4 are further improved by having the Vicat softening point of the adhesive layer 3 within the above range are not necessarily clear. For example, it can be considered as follows. That is, if the vicad softening point is less than 95 ° C., the resin used for the adhesive layer flows out due to the heat at the time of heat sealing, and the thickness becomes thin, so that the insulating property deteriorates. Further, when the vicad softening point is larger than 105 ° C., the softening due to heat at the time of heat sealing is slowed down, and an undissolved portion of the resin is generated, so that the adhesiveness is lowered.

Further, when the number average molecular weight (Mn) and the weight average molecular weight (Mw) of the resins constituting the adhesive layer 3 are within the above ranges, the metal layer 2 and the thermosetting resin layer 4 are separated from each other. The details of the mechanism for further improving the adhesiveness and the insulating property are not always clear, but can be considered, for example, as follows. That is, when the number average molecular weight (Mn) is smaller than 61,000, since there are many low molecular weight components, the amount of crushing due to the pressure at the time of heat sealing becomes large, and the insulating property deteriorates. Further, when the number average molecular weight (Mn) is larger than 65,000, there are few low molecular weight components, there is a concern that the MFR is lowered, and the film forming property may be impaired. Further, when the weight average molecular weight (Mw) is smaller than 350,000, the amount of crushing due to the pressure at the time of heat sealing becomes large because the amount of high molecular weight material is small as a whole, and the insulating property is lowered. Further, when the weight average molecular weight (Mw) is larger than 410,000, there is a concern that the MFR may be lowered and the film forming property may be impaired because there are many high molecular weight bodies as a whole. Further, when the dispersity (Mw / Mn) of the resin constituting the adhesive layer 3 is within the above range, the adhesiveness and the insulating property between the metal layer 2 and the thermosetting resin layer 4 are further improved. The details of the mechanism of improvement are not always clear, but can be considered, for example, as follows. That is, if the dispersity (Mw / Mn) is smaller than 6.0, the molecular weight distribution is narrow, and there is a risk of causing a decrease in film-forming property such as neck-in during extrusion. Further, when the dispersity (Mw / Mn) is larger than 7.0, the molecular weight distribution becomes wide and the low molecular weight components also increase, so that the amount of crushing due to the pressure at the time of heat sealing becomes large and the insulating property deteriorates.

The thickness of the adhesive layer 3 is not particularly limited as long as it functions as an adhesive layer, but from the viewpoint of exhibiting excellent insulating properties, it is preferably 2 μm or more and 50 μm or less, and more preferably 10 μm or more and 40 μm or less.

[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 thermosetting resin layer 4 is not particularly limited as long as it can be heat-fused. In the present invention, since the hard adhesive layer 3 having a logarithmic decrement of 0.08 or less at a relatively high temperature of 80 ° C. is arranged between the metal layer 2 and the heat-sealing resin layer 4, the battery From the viewpoint of exhibiting high heat-sealing property in packaging materials for use, the heat-sealing resin layer 4 preferably has a logarithmic decrement rate ΔE2 at 80 ° C. of 0.04 or more in a rigid pendulum measurement. It is more preferably 0.10 or less, and further preferably 0.05 or more and 0.09 or less.

From the same viewpoint, the thermosetting resin layer 4 preferably contains at least one of a polyolefin and a cyclic polyolefin, and more preferably contains a polyolefin.

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 copolymer (for example, propylene and ethylene block copolymer), and polypropylene. Polypropylene such as random copolymers (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 which is a constituent monomer of the cyclic polyolefin include ethylene, propylene, 4-methyl-1-pentene, styrene, butadiene, isoprene, and the like. Be done. Examples of the cyclic monomer which 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.

Further, the thermosetting resin layer 4 may contain an acid-modified polyolefin. The acid-modified polyolefin is not particularly limited, but preferably carboxylic acid-modified polyolefin and carboxylic acid-modified cyclic polyolefin.

The carboxylic acid-modified polyolefin is a polymer modified by block-polymerizing or graft-polymerizing the above-mentioned 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 is obtained by copolymerizing a part of the monomers constituting the cyclic polyolefin in place of α, β-unsaturated carboxylic acid or its anhydride, or α, β-with respect to the cyclic polyolefin. It is a polymer obtained by block polymerization or graft polymerization of unsaturated carboxylic acid or its anhydride. The same applies to the cyclic polyolefin modified with carboxylic acid. Examples of the carboxylic acid used for modification include maleic acid, acrylic acid, itaconic acid, crotonic acid, maleic anhydride, itaconic anhydride and the like.

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

In the present invention, a hard adhesive layer 3 having a logarithmic decrement of 0.08 or less at a relatively high temperature of 80 ° C. is arranged between the metal layer 2 and the thermosetting resin layer 4. Therefore, from the viewpoint of achieving both high insulation and high heat sealability in the packaging material for batteries, the ratio of the logarithmic decrement ΔE1 of the adhesive layer 3 to the logarithmic decrement ΔE2 of the heat-sealing resin layer 4 (ΔE2 / ΔE1). ) Is preferably in the range of 0.6 or more and 3.8 or less, and more preferably in the range of 0.7 or more and 3.5 or less.

The logarithmic decrement rate ΔE2 at 80 ° C. in the rigid pendulum measurement of the thermosetting resin layer 4 is, for example, the content, melting point, MFR, number average molecular weight, and weight average molecular weight of the polyolefin contained in the thermosetting resin layer 4. By adjusting the degree of dispersion, the vicut softening point, and the like, the above-mentioned preferable range can be set.

From the viewpoint of achieving both high insulation and high heat-sealing properties in the battery packaging material, the melting point of the thermosetting resin layer 4 is preferably 130 ° C. or higher, more preferably 135 ° C. or higher and 165 ° C. or lower. The melting point of the thermosetting resin layer 4 is a value measured using a differential scanning calorimeter (DSC). The melting point of the thermosetting resin layer 4 can be measured with respect to the resin (for example, pellets) used for forming the thermosetting resin layer 4. Further, after the battery packaging material is formed, the thermosetting resin layer 4 obtained from the battery packaging material can be measured.

The MFR (230 ° C., load 2.16 kg) of the thermosetting resin layer 4 is not particularly limited, but is preferably 5 g / 10 minutes from the viewpoint of imparting high insulation and heat sealability to the battery packaging material. 20 g / 10 minutes or less can be mentioned. From the same viewpoint, the Vicat softening point of the thermosetting resin layer 4 is preferably 95 ° C. or higher and 120 ° C. or lower. From the same viewpoint, the number average molecular weight (Mn) of the resin constituting the thermosetting resin layer 4 is preferably 70,000 or more and 80,000 or less, and the weight average molecular weight (Mw) is preferably 70,000 or more. , 320,000 or more and 370,000 or less, and the dispersity (Mw / Mn) is 4.5 or more and 5.5 or less.

The details of the mechanism by which the vicut softening point of the thermosetting resin layer 4 is within the above range to impart high insulation and heat sealability to the battery packaging material are not necessarily clear, but for example, , Can be thought of as follows. That is, if the vicad softening point is less than 95 ° C., the resin used in the thermosetting resin layer flows out due to the heat during heat sealing, and the thickness becomes thin, so that the insulating property deteriorates. Further, when the vicad softening point is larger than 120 ° C., the softening due to heat at the time of heat sealing is slowed down, and an undissolved portion of the resin is generated, so that the adhesiveness between the thermosetting resin layers is lowered.

Further, the number average molecular weight (Mn) and the weight average molecular weight (Mw) of the resins constituting the thermosetting resin layer 4 are within the above ranges, so that the packaging material for the battery has higher insulating properties. The details of the mechanism that can impart the heat-sealing property are not always clear, but can be considered, for example, as follows. That is, when the number average molecular weight (Mn) is smaller than 70,000, since there are many low molecular weight components, the amount of crushing due to the pressure at the time of heat sealing becomes large, and the insulating property deteriorates. Further, when the number average molecular weight (Mn) is larger than 80,000, there are few low molecular weight components, there is a concern that the MFR is lowered, and the film forming property may be impaired. Further, when the weight average molecular weight (Mw) is smaller than 320,000, the amount of crushing due to the pressure at the time of heat sealing becomes large because the amount of high molecular weight material is small as a whole, and the insulating property is lowered. Further, when the weight average molecular weight (Mw) is larger than 370,000, there is a concern that the MFR may be lowered and the film forming property may be impaired because there are many high molecular weight bodies as a whole. Further, when the dispersity (Mw / Mn) of the resin constituting the heat-sealing resin layer 4 is within the above range, higher insulation and heat sealability can be imparted to the battery packaging material. The details of the mechanism are not always clear, but can be considered, for example, as follows. That is, if the dispersity (Mw / Mn) is smaller than 4.5, the molecular weight distribution is narrow, and there is a risk of causing a decrease in film-forming property such as neck-in during extrusion. Further, when the dispersity (Mw / Mn) is larger than 5.5, the molecular weight distribution becomes wide and the low molecular weight components also increase, so that the amount of crushing due to the pressure at the time of heat sealing becomes large and the insulating property deteriorates.

The thickness of the thermosetting resin layer 4 can be appropriately selected, but is preferably 10 μm or more and 100 μm or less from the viewpoint of achieving both high insulation and high heat sealability in the battery packaging material. Preferably, it is 15 μm or more and 50 μm or less.

Further, the thermosetting resin layer 4 may contain a lubricant or the like, if necessary. When the thermosetting 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. 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. When the lubricant is present on the surface of the heat-sealing resin layer 4, the amount of the lubricant is not particularly limited, but is preferably 10 mg / m ² or more, more preferably 10 mg / m at a temperature of 24 ° C. and a humidity of 60%. ² or more and 50 mg / m ² or less, more preferably 15 mg / m ² or more and 40 mg / m ² or less.

[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 2), 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 or more and 5 μm or less. 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, silica, barium sulfate, and titanium oxide are preferable 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 thickness of the surface coating layer is not particularly limited as long as it exhibits the above-mentioned function as the surface coating layer, and examples thereof include 0.5 μm or more and 10 μm or less, preferably 1 μm or more and 5 μm or less.

3. 3. Method for Producing Battery Packaging Material The method for producing the battery packaging material of the present invention is not particularly limited as long as a laminate in which each layer having a predetermined composition is laminated can be obtained. An example of the method for producing the packaging material for a battery of the present invention is as follows. First, a laminate in which the base material layer 1, the adhesive layer 5, and the metal layer 2 are laminated in this order (hereinafter, may be referred to as “laminate A”) is formed. Specifically, the laminate A is formed by applying an adhesive used for forming the adhesive layer 5 on the base material layer 1 or, if necessary, on the metal layer 2 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 2 or the base material layer 1 is laminated and the adhesive layer 5 is cured after being coated and dried by a coating method such as a roll coating method.

Next, the adhesive layer 3 and the thermosetting resin layer 4 are laminated on the metal layer 2 of the laminated body A in this order. For example, (1) a method of laminating the adhesive layer 3 and the thermosetting resin layer 4 on the metal layer 2 of the laminated body A by co-extruding (co-extrusion laminating method), (2) separately, the adhesive layer 3 A method of forming a laminated body in which the thermosetting resin layer 4 and the thermosetting resin layer 4 are laminated and laminating this on the metal layer 2 of the laminated body A by a thermal laminating method. The adhesive for forming the layer 3 is laminated by an extrusion method, a solution-coated high-temperature drying method, a baking method, or the like, and a thermosetting resin layer 4 previously formed into a sheet on the adhesive layer 3 is thermally formed. A method of laminating by a laminating method, (4) An adhesive layer while pouring a molten adhesive layer 3 between a metal layer 2 of a laminate A and a thermosetting resin layer 4 which has been formed into a sheet in advance. A method of laminating the laminated body A and the thermosetting resin layer 4 via 3 (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 2. 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 2 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 2 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 5 / a metal layer 2 whose surface is chemically treated as needed / an adhesive layer 3 / A laminate composed of the heat-sealing resin layer 4 is formed, and in order to strengthen the adhesiveness of the adhesive layer 5 or the adhesive layer 3, a hot roll contact type, a hot air type, a near or far infrared type is further formed. It may be subjected to heat treatment such as. Examples of the conditions for such heat treatment include 1 minute to 5 minutes at 150 ° C. or higher and 250 ° C. or lower.

In the packaging material for batteries of the present invention, each layer constituting the laminated body improves or stabilizes film forming property, laminating process, suitability for secondary processing (pouching, embossing) of the final product, etc., as necessary. Therefore, surface activation treatments 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 in 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 battery packaging material 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.

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

Example 1-2 and Comparative Example 1-6
<Manufacturing of packaging materials for batteries>
Both sides of a base material layer composed of a biaxially stretched polyethylene terephthalate film (thickness 12 μm) and a biaxially stretched nylon film (thickness 15 μm) laminated by a dry laminating method were subjected to chemical conversion treatment on both sides. A metal layer made of aluminum foil (JIS H 4000: 2014 A8021PO, thickness 40 μm) was laminated by a dry laminating method. Specifically, a two-component urethane adhesive (polyol compound and aromatic isocyanate compound) was applied to one surface of the aluminum foil to form an adhesive layer (thickness 3 μm) on the metal layer. Next, after laminating the adhesive layer and the base material layer on the metal layer, an aging treatment was carried out at 40 ° C. for 24 hours to prepare a laminated body of the base material layer / adhesive layer / metal layer. In the chemical conversion treatment of the aluminum foil used as the metal layer, a treatment liquid consisting of a phenol resin, a chromium fluoride compound, and phosphoric acid was roll-coated so that the ^{amount of chromium applied was 10 mg / m 2 (dry mass).} It was applied to both sides of the aluminum foil by the method and baked for 20 seconds under the condition that the film temperature was 180 ° C. or higher.

Next, on the metal layer of the laminated body, an adhesive layer having the physical properties shown in Table 1 (thickness 40 μm, arranged on the metal layer side) and a thermosetting resin layer (thickness 40 μm, innermost layer) are combined. By extruding, an adhesive layer / thermosetting resin layer was laminated on the metal layer. Next, the obtained laminate is aged at a temperature of 80 ° C. for 24 hours, and finally heated at 190 ° C. for 2 minutes to obtain a base material layer, an adhesive layer, a metal layer, an adhesive layer, and thermosetting properties. A packaging material for batteries in which resin layers were laminated in this order was obtained. As the adhesive layer, those having a number average molecular weight of 63,300 in Example 1, 61,900 in Example 2, and 58,100 in Comparative Example 1 were used. As the thermosetting resin layer, MFR (230 ° C., load 2.16 kg) was 11 g / 10 minutes in Examples 1 to 4 and 4 g / 10 minutes in Comparative Examples 1 to 4, and had a number average molecular weight. However, 73,000 were used in Examples 1 to 4, and 61,100 were used in Comparative Examples 1 to 4.

<Measurement of logarithmic decrement>
A rigid pendulum physical property tester (model number: RPT-3000W, manufactured by A & D Co., Ltd.) is used, FRB-100 is used for the pendulum, and cylindrical cylinder edge RBP- 020 is used for the edge part, and the initial amplitude is set. It was set to about 0.3 degree. The cylindrical cylinder edge was brought into contact with the surface of the adhesive layer. Next, the logarithmic decrement rate ΔE1 of the adhesive layer and the logarithmic decrement rate ΔE2 of the thermosetting resin layer were measured in a temperature range of 30 ° C. or higher and 130 ° C. or lower at a heating rate of 5 ° C./min. Table 1 shows the logarithmic decay rates ΔE1 and ΔE2 at 80 ° C. The thermosetting resin layer was measured on the surface of the thermosetting resin layer of each battery packaging material obtained above. As for the adhesive layer, the base material layer of each battery packaging material obtained above is dissolved with hydrofluoric acid, and then the aluminum foil of the metal layer is dissolved with hydrochloric acid to expose the surface of the adhesive layer. And the measurement was performed. The results are shown in Table 1.

<Measurement of melting point>
The melting points of the adhesive layer and the heat-sealing resin layer are raised in a nitrogen atmosphere at a rate of 10 ° C./min using a differential scanning calorimeter (DSC), respectively, and the endothermic peaks observed at that time are observed. Measured from the peak position. The results are shown in Table 1.

<Measurement of melt tension>
The melt tension of the adhesive layer is Capillary Graph 1C ((barrel diameter 9.55 mmΦ), barrel temperature 190 ° C., capillary length (L) = 8 mm, capillary diameter (D) = 2.095 mm, L / D) manufactured by Toyo Seiki Seisakusho Co., Ltd. = 3.82), the measurement was performed under the conditions of piston speed = 15 mm / min and winding speed = 15 mm / min, and the average value of the obtained values was taken as the melt tension (190 ° C.).

<Insulation evaluation>
As shown in the schematic view of FIG. 3, each battery packaging material obtained above was cut into a rectangle of 40 mm (horizontal direction) × 100 mm (longitudinal direction) to obtain a test piece (FIG. 3 (a)). Next, the test pieces were folded back so that their short sides faced each other, and the surfaces of the thermosetting resin layers of the test pieces were arranged so as to face each other. Next, a wire M having a diameter of 25 μm was inserted between the surfaces of the thermosetting resin layers facing each other (FIG. 3 (b)). Next, in this state, the heat-weldable resin layers were heat-sealed with each other by a heat-sealing machine made of a flat plate-shaped hot plate having a width of 7 mm in the horizontal direction of the battery packaging material (FIG. 3 (c), heat-welded portion. S). At this time, heat sealing (heat sealing conditions: 190 ° C., 1.0 MPa) was performed from above the portion where the wire M is located, and the thermosetting resin layer was heat-sealed to the wire M. Next, the positive pole of the tester was connected to the wire M, and the negative pole was connected to the battery packaging material on one side. At this time, with respect to the negative pole of the tester, an alligator clip was sandwiched so as to reach the aluminum layer from the base material layer side of the electrical packaging material, and the negative pole of the tester and the aluminum foil were electrically connected. Next, apply a voltage of 100V between the testers, measure the time (seconds) until short-circuiting, A if there is no short-circuit for 120 seconds or more, B if it is 60 seconds or more and shorter than 120 seconds, 30 seconds or more and 60 seconds or more. When it was short, it was judged as C, and when it was shorter than 0 to 29 seconds, it was judged as D. The results are shown in Table 1.

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

Claims (7)

It is composed of a laminate having at least a base material layer, a metal layer, an adhesive layer, and a thermosetting resin layer in this order.
The adhesive layer is formed of acid-modified polyolefin and is formed of an acid-modified polyolefin.
The adhesive layer state, and are logarithmic decrement of ΔE1 is 0.08 or less at 80 ° C. in a rigid pendulum measurement,
The melting point of the adhesive layer is Ru der 140 ° C. or higher, the packaging material for a battery. The packaging material for a battery according to claim 1 , wherein the heat-sealing resin layer has a logarithmic decrement rate ΔE2 at 80 ° C. in a rigid pendulum measurement of 0.04 or more. The packaging material for a battery according to claim 2 , wherein the ratio (ΔE2 / ΔE1) of the logarithmic decrement rate ΔE1 to the logarithmic decrement rate ΔE2 is in the range of 0.5 or more and 4.0 or less. The packaging material for a battery according to any one of claims 1 to 3 , wherein the adhesive layer has a melt tension of 40 mN or more at 190 ° C. The battery packaging material according to any one of claims 1 to 4 , wherein the thermosetting resin layer contains polyolefin. The battery packaging material according to any one of claims 1 to 5 , wherein the metal layer is formed of aluminum foil. 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 claims 1 to 6.