JP7244206B2 - Packaging materials and batteries - Google Patents

Description

The present invention relates to packaging materials and batteries.

2. Description of the Related Art Conventionally, packaging materials for packaging contents have been widely used in fields such as foods and pharmaceuticals. As such a packaging material, a film-like laminate in which a base material/barrier layer/thermal adhesive resin layer are sequentially laminated is known. The contents can be sealed.

In addition, in recent years, with the increasing performance of electric vehicles, hybrid electric vehicles, personal computers, cameras, mobile phones, etc., batteries are required to have various shapes and to be thinner and lighter. However, metal packaging materials, which have been widely used in the past, have the disadvantage that it is difficult to follow the diversification of shapes and that there is a limit to weight reduction. Therefore, in the field of batteries, as a packaging material that can be easily processed into a variety of shapes and that can be made thinner and lighter, instead of metal packaging materials, base material / barrier layer / heat-sealable resin A film-like laminate in which layers are sequentially laminated has been proposed (Patent Document 1).

These various packaging materials are subject to strong impact from the outside during transportation, etc., and are required to have high impact resistance. On the other hand, in recent years, from the viewpoint of thinning and weight saving of products, there is a demand for further thinning of packaging materials. However, when the thickness of the packaging material is reduced, there is a problem that the impact resistance is lowered.

JP 2008-287971 A

A main object of the present invention is to provide a packaging material having excellent impact resistance in a packaging material comprising a laminate comprising at least a substrate layer, a barrier layer, and a heat-fusible resin layer in this order. .

The present inventors have made extensive studies to solve the above problems. As a result, a packaging material comprising a laminate comprising at least a substrate layer, a barrier layer, and a heat-fusible resin layer in this order was subjected to a tensile test under the following test conditions for the laminate. The breaking energy per unit width 1m calculated from the curve of "test force-displacement" is one direction perpendicular to the thickness direction of the laminate, and the direction perpendicular to the one direction and the thickness direction of the laminate It has been found that a packaging material having excellent impact resistance can be obtained by making the total of 400 J or more in the other directions. The present invention has been completed through further studies based on these findings.
(Test condition)
Test speed: 50mm/min
Width of test piece: 15 mm
Length of test piece: 100 mm
Gauge distance: 30 mm

That is, the present invention provides packaging materials and batteries in the following aspects.
Section 1. Consists of a laminate comprising at least a substrate layer, a barrier layer, and a heat-fusible resin layer in this order,
The laminate is measured when a tensile test is performed under the following test conditions, and the breaking energy per unit width of 1m calculated from the test force-displacement curve is perpendicular to the thickness direction of the laminate. A packaging material having a total of 400 J or more in one direction and the other direction perpendicular to said one direction and the thickness direction of said laminate.
(Test condition)
Test speed: 50mm/min
Width of test piece: 15 mm
Length of test piece: 100mm
Gauge distance: 30 mm
Section 2. Item 2. The packaging material according to Item 1, wherein the one direction is the MD of the laminate, and the other direction is the TD of the laminate.
Item 3. Item 3. The packaging material according to Item 1 or 2, wherein the laminate has a puncture strength of 23 N or more measured from the base layer side by a method conforming to JIS Z1707:1995.
Section 4. Any of items 1 to 3, wherein the laminate complies with JIS K7124-2:1999 and has a total penetration energy of 1.4 J or more measured from the base layer side under the following measurement conditions. packaging material according to
(Measurement condition)
Hammer weight: 6.4kg
Drop height: 300mm
Sample clamp diameter: 40mmφ
Hammer diameter: 12.7mm
Hammer shape: hemispherical Item 5. Item 5. The packaging material according to any one of Items 1 to 4, wherein the base material layer has a thickness of 20 μm or more.
Item 6. Item 6. The packaging material according to any one of Items 1 to 5, wherein the barrier layer is made of aluminum foil.
Item 7. Item 7. The packaging material according to any one of Items 1 to 6, which is used for housing a battery element.
Item 8. Item 8. A battery, wherein a battery element comprising at least a positive electrode, a negative electrode, and an electrolyte is housed in a package formed of the packaging material according to any one of items 1 to 7.

According to the present invention, a packaging material comprising a laminate comprising at least a substrate layer, a barrier layer, and a heat-fusible resin layer in this order is measured when a tensile test is performed on the laminate under the above test conditions. The breaking energy per unit width 1m calculated from the curve of "test force-displacement" is one direction perpendicular to the thickness direction of the laminate, the one direction and the thickness direction of the laminate is 400 J or more in total in the other vertical directions, it is possible to provide a packaging material with excellent impact resistance.

It is a figure which shows an example of the cross-sectional structure of the packaging material of this invention. It is a figure which shows an example of the cross-sectional structure of the packaging material of this invention. It is a figure which shows an example of the cross-sectional structure of the packaging material of this invention. 10 is a test force-displacement curve (MD) obtained in a tensile test of the packaging material of Comparative Example 2. FIG. FIG. 10 is a schematic diagram showing a part where the data of the test force-displacement curve is integrated.

The packaging material of the present invention comprises at least a laminate comprising a substrate layer, a barrier layer, and a heat-fusible resin layer in this order. The breaking energy per unit width 1m calculated from the test force-displacement curve measured in is one direction perpendicular to the thickness direction of the laminate, the one direction and the thickness direction of the laminate is 400 J or more in total in the other vertical directions. The packaging material of the present invention will be described in detail below.
(Test condition)
Test speed: 50mm/min
Width of test piece: 15 mm
Length of test piece: 100 mm
Gauge distance: 30 mm

In this specification, the numerical range indicated by "-" means "more than" and "less than". For example, the notation of 2 to 15 mm means 2 mm or more and 15 mm or less.

1. Laminated structure and physical properties of packaging material The packaging material of the present invention comprises, for example, as shown in FIG. be done. In the packaging material of the present invention, the substrate layer 1 is the outermost layer, and the heat-fusible resin layer 4 is the innermost layer. That is, when the battery is assembled, the heat-sealable resin layers 4 positioned at the periphery of the battery element are heat-sealed to seal the battery element, thereby sealing the battery element.

In the packaging material of the present invention, as shown in FIG. 2, an adhesive layer 2 is optionally provided between a base layer 1 and a barrier layer 3 for the purpose of enhancing adhesion between them. good too. In the packaging material of the present invention, for example, as shown in FIG. 3, an adhesive layer 5 is optionally provided between the barrier layer 3 and the heat-fusible resin layer 4 for the purpose of enhancing the adhesion between them. may be provided.

In the laminate constituting the packaging material of the present invention, the breaking energy per unit width of 1 m calculated from the curve of "test force-displacement" measured when a tensile test is performed under the above test conditions is One direction perpendicular to the thickness direction of the laminate (that is, the lamination direction of the laminate) and the other direction perpendicular to the one direction and the thickness direction of the laminate (that is, the other direction is the one direction) the direction perpendicular to the direction and the direction perpendicular to the thickness direction of the laminate) is 400 J or more in total. From the viewpoint of improving the impact resistance while reducing the thickness of the packaging material, the one direction is the MD (Machine Direction) of the laminate, and the other direction is the TD (Transverse Direction) of the laminate. is preferred. That is, the breaking energy per unit width of 1 m calculated from the "test force-displacement" curve measured when the tensile test is performed under the above test conditions is the MD, which is the flow direction of the laminate, It is preferable that the sum of TD in the vertical direction is 400 J or more. In addition, in this invention, a tensile test means the test of a tensile property.

In addition, from the viewpoint of improving the impact resistance while reducing the thickness of the packaging material, the lower limit of the breaking energy is preferably about 450 J or more, more preferably about 500 J or more. From the viewpoint of suitable molding, the upper limit is about 1000 J or less, more preferably about 800 J or less. The range of the breaking energy is preferably about 400 to 1000J, about 400 to 800J, about 450 to 1000J, about 450 to 800J, about 500 to 1000J, and about 500 to 800J.

In the packaging material, the MD and TD in the manufacturing process can usually be discriminated for the later-described barrier layer. For example, when the barrier layer is made of aluminum foil, linear streaks called so-called rolling marks are formed on the surface of the aluminum foil in the rolling direction (RD) of the aluminum foil. Since the rolling marks extend along the rolling direction, the rolling direction of the aluminum foil can be grasped by observing the surface of the aluminum foil. In addition, in the manufacturing process of the laminate, the MD of the laminate usually coincides with the RD of the aluminum foil, so the surface of the aluminum foil of the laminate is observed to identify the rolling direction (RD) of the aluminum foil. Thus, the MD of the laminate can be specified. Moreover, since the TD of the laminate is perpendicular to the MD of the laminate, the TD of the laminate can also be specified.

In the present invention, the breaking energy per unit width of 1 m in the one direction and the other direction of the laminate constituting the packaging material is measured in the one direction and the other direction of the laminate in a tensile test under the above test conditions. Obtain data on the test force-displacement curve measured when performing, save the data in csv file format, and use spreadsheet software (Excel (registered trademark) of Microsoft Corporation) Laminate Calculation is performed by integrating the data until rupture. At this time, the breaking energy per 1 m width of each packaging material is converted (divided by 0.015) and calculated using the spreadsheet software. Then, the breaking energy per unit width of 1 m in one direction and the breaking energy per unit width of 1 m in the other direction are totaled. In addition, when the laminate is broken means when the test piece is broken. Five packaging materials to be measured are prepared, for example, among the breaking energy values for five samples, the average of three values excluding the maximum and minimum values is taken as the breaking energy of the laminate. . Even if five samples cannot be prepared, it is preferable to use the average of the number of samples that can be measured. Moreover, in the tensile test, a commercially available tensile tester can be used.

In addition, from the viewpoint of improving the impact resistance while reducing the thickness of the packaging material, the laminate constituting the packaging material of the present invention is prepared by a method conforming to JIS Z1707: 1995. The lower limit of the puncture strength measured from is preferably about 23 N or more, more preferably about 24 N or more, and still more preferably about 26 N or more. is preferably about 50 N or less, more preferably about 40 N or less. The range of the puncture strength is preferably about 23 to 50N, about 23 to 40N, about 24 to 50N, about 24 to 40N, about 26 to 50N, and about 26 to 40N.

Furthermore, from the viewpoint of improving the impact resistance while reducing the thickness of the packaging material, the laminate constituting the packaging material of the present invention includes a base material layer 1, a barrier layer 3, and a heat-sealable resin, which will be described later. For Layer 4, the total value of the puncture strength measured in accordance with JIS Z1707:1995 is preferably 23 N or more, preferably 23 to 50 N, and 23 to 40 N. It is even more preferable to have In addition, when the laminate constituting the packaging material of the present invention has only the heat-fusible resin layer 4 disposed inside the barrier layer 3 as shown in FIGS. The piercing strength of is the piercing strength measured only for the heat-fusible resin layer 4. As shown in FIG. When the resin layer 4 is arranged, the piercing strength is the piercing strength measured for the laminate of the adhesive layer 5 and the heat-fusible resin layer 4 .

From the viewpoint of improving the impact resistance while reducing the thickness of the packaging material, the laminate constituting the packaging material of the present invention complies with the provisions of JIS K7124-2: 1999, and the base material is measured under the following measurement conditions. As for the total penetration energy measured from the layer 1 side, the lower limit is preferably about 1.4 J or more, more preferably 1.5 J or more, and from the viewpoint of suitably forming the packaging material, the upper limit is It is preferably 5.0 J or less, more preferably 4.5 J or less. The range of the total penetration energy is preferably about 1.4 to 5.0 J, about 1.4 to 4.5 J, about 1.5 to 5.0 J, and about 1.5 to 4.5 J. .

(Measurement condition)
Hammer weight: 6.4kg
Drop height: 300mm
Sample clamp diameter: 40mmφ
Hammer diameter: 12.7mm
Hammer shape: hemispherical

Regarding the impact resistance of the packaging material of the present invention, for example, when the heat-sealable resin layers 4 are heat-sealed to seal the contents, the packaging material breaks when a strong impact is applied from the outside. It is evaluated by whether the contents are exposed to the outside. For example, conventional batteries sealed with a metal can are evaluated for impact resistance by a method conforming to UL1642. When the packaging material of the present invention is used, for example, to house a battery element (i.e., battery packaging material), it passes impact resistance evaluated by a method conforming to UL1642 (smoke generation, It is preferable that it does not cause ignition or the like).

The thickness of the laminate constituting the packaging material of the present invention is not particularly limited, but from the viewpoint of making the thickness as thin as possible while ensuring excellent impact resistance, the upper limit is preferably about 160 μm or less, and more It is preferably about 155 μm or less, more preferably about 120 μm or less, and the lower limit is preferably about 35 μm or more, more preferably about 45 μm or more. The thickness range of the laminate is preferably about 35 to 160 μm, about 35 to 155 μm, about 35 to 120 μm, about 45 to 160 μm, about 45 to 155 μm, and about 45 to 120 μm. Even when the thickness of the laminate constituting the packaging material of the present invention is as thin as, for example, about 160 μm or less, the present invention can exhibit excellent impact resistance. Therefore, the packaging material of the present invention can contribute to improving the energy density of batteries.

2. Each layer forming the packaging material [base material layer 1]
In the packaging material of the present invention, the substrate 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 insulating properties. Materials for forming the base material layer 1 include, for example, polyester, polyamide, epoxy resin, acrylic resin, fluororesin, polyurethane, silicon resin, phenol resin, polyetherimide, polyimide, and mixtures and copolymers thereof. mentioned.

Specific examples of polyester include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, polycarbonate, copolymer polyester mainly composed of repeating units of ethylene terephthalate, and butylene terephthalate as repeating units. Examples include copolyester, which is the main component. Further, as the copolymer polyester having ethylene terephthalate as the main repeating unit, specifically, a copolymer polyester polymerized with ethylene isophthalate having ethylene terephthalate as the main repeating unit (hereinafter referred to as polyethylene (terephthalate/isophthalate) ), polyethylene (terephthalate/isophthalate), polyethylene (terephthalate/adipate), polyethylene (terephthalate/sodium sulfoisophthalate), polyethylene (terephthalate/sodium isophthalate), polyethylene (terephthalate/phenyl-dicarboxylate) , polyethylene (terephthalate/decanedicarboxylate), and the like. Further, as the copolymer polyester having butylene terephthalate as the main repeating unit, specifically, a copolymer polyester polymerized with butylene isophthalate having butylene terephthalate as the main repeating unit (hereinafter referred to as polybutylene (terephthalate/isophthalate) ), polybutylene (terephthalate/adipate), polybutylene (terephthalate/sebacate), polybutylene (terephthalate/decanedicarboxylate), polybutylene naphthalate, and the like. These polyesters may be used singly or in combination of two or more. Polyester has the advantage of being excellent in electrolytic solution resistance and less likely to cause whitening or the like due to adhesion of the electrolytic solution.

Specific examples of polyamides include aliphatic polyamides such as nylon 6, nylon 66, nylon 610, nylon 12, nylon 46, and copolymers of nylon 6 and nylon 66; terephthalic acid and/or isophthalic acid; Hexamethylenediamine-isophthalic acid-terephthalic acid copolymer polyamide such as nylon 6I, nylon 6T, nylon 6IT, nylon 6I6T (I represents isophthalic acid, T represents terephthalic acid) containing structural units derived from Polyamides containing aromatics such as pamido (MXD6); alicyclic polyamides such as polyaminomethylcyclohexyladipamide (PACM6); and copolymerization of lactam components and isocyanate components such as 4,4'-diphenylmethane-diisocyanate. polyester amide copolymers and polyether ester amide copolymers, which are copolymers of copolyamide and polyester or polyalkylene ether glycol; copolymers thereof, and the like. These polyamides may be used singly or in combination of two or more. The stretched polyamide film is excellent in stretchability and can prevent whitening due to cracking of the resin in the substrate layer 1 during molding.

The substrate 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, is preferably used as the substrate layer 1 because its heat resistance is improved by oriented crystallization. Moreover, the base material layer 1 may be formed by coating the above material on the barrier layer 3 .

Among these, the resin film forming the substrate layer 1 is preferably nylon or polyester, more preferably biaxially oriented nylon or biaxially oriented polyester, particularly preferably biaxially oriented nylon.

The base material layer 1 can be formed by laminating (multilayer structure) at least one of resin films and coatings made of different materials in order to improve pinhole resistance and insulation when used as a battery package. be. Specific examples include a multilayer structure in which a polyester film and a nylon film are laminated, a multilayer structure in which a plurality of nylon films are laminated, a multilayer structure in which a plurality of polyester films are laminated, and the like. When the substrate layer 1 has a multilayer structure, a laminate of a biaxially stretched nylon film and a biaxially stretched polyester film, a laminate of a plurality of biaxially stretched nylon films, and a laminate of a plurality of biaxially stretched polyester films. body is preferred. In addition, biaxially stretched polyester is resistant to discoloration when, for example, an electrolytic solution adheres to the surface. , The substrate layer 1 is preferably a laminate having biaxially oriented nylon and biaxially oriented polyester in this order from the barrier layer 3 side. When the substrate layer 1 has a multilayer structure, the thickness of each layer is preferably about 3 to 25 μm.

When the substrate layer 1 has a multi-layer structure, each resin film may be adhered via an adhesive, or may be directly laminated without an adhesive. In the case of bonding without using an adhesive, for example, a method of bonding in a heat-melted state such as a coextrusion method, a sandwich lamination method, a thermal lamination method, or the like can be used. Moreover, when bonding via an adhesive, the adhesive to be used may be a two-component curing adhesive or a one-component curing adhesive. Furthermore, the adhesion 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 heat pressure type, an ultraviolet curing type, an electron beam curing type, and the like. Specific examples of the adhesive are the same as those exemplified for the adhesive layer 2 . Also, the thickness of the adhesive can be the same as that of the adhesive layer 2 .

In the present invention, it is preferable that a lubricant is adhered to the surface of the substrate layer 1 from the viewpoint of improving the moldability of the packaging material. The lubricant is not particularly limited, but preferably includes an amide-based lubricant. Specific examples of amide-based lubricants include saturated fatty acid amides, unsaturated fatty acid amides, substituted amides, methylolamides, saturated fatty acid bisamides, and unsaturated fatty acid bisamides. Specific examples of saturated fatty acid amides include lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, and hydroxystearic acid amide. Specific examples of unsaturated fatty acid amides include oleic acid amide and erucic acid amide. Specific examples of substituted amides include N-oleyl palmitic acid 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 methylol stearamide. Specific examples of saturated fatty acid bisamides include methylenebisstearic acid amide, ethylenebiscapric acid amide, ethylenebislauric acid amide, ethylenebisstearic acid amide, ethylenebishydroxystearic acid amide, ethylenebisbehenic acid amide, hexamethylenebisstearin. acid amide, hexamethylenebisbehenamide, hexamethylenehydroxystearic acid amide, N,N'-distearyladipic acid amide, N,N'-distearylsebacic acid amide and the like. Specific examples of unsaturated fatty acid bisamides include ethylenebisoleic acid amide, ethylenebiserucic acid amide, hexamethylenebisoleic acid amide, N,N'-dioleyladipic acid amide, and N,N'-dioleylsebacic acid amide. etc. Specific examples of fatty acid ester amides include stearamide ethyl stearate. Further, specific examples of the aromatic bisamide include m-xylylenebisstearic acid amide, m-xylylenebishydroxystearic acid amide, N,N'-distearyl isophthalic acid amide and the like. Lubricants may be used singly or in combination of two or more.

The content of the lubricant in the base material layer 1 is not particularly limited, and from the viewpoint of enhancing the moldability and insulating properties of the electronic packaging material, it is preferably about 0.01 to 0.2% by mass, more preferably 0. 0.05 to 0.15% by mass.

The thickness of the substrate layer 1 is preferably about 10 μm or more, more preferably about 20 μm or more, as the lower limit from the viewpoint of making the packaging material excellent in impact resistance while reducing the thickness of the packaging material. The upper limit is preferably about 75 μm or less, more preferably about 50 μm or less. The range of thickness of the base layer 1 is preferably about 10 to 75 μm, about 10 to 50 μm, about 20 to 75 μm, and about 20 to 50 μm. In addition, in this invention, when the base material layer 1 is a multilayer structure adhere|attached with the adhesive agent, the thickness of the said adhesive agent is not included in the thickness of the base material layer 1. FIG.

[Adhesive layer 2]
In the packaging material of the present invention, the adhesive layer 2 is a layer provided between the substrate layer 1 and the barrier layer 3 in order to firmly bond them.

The adhesive layer 2 is made of an adhesive capable of bonding the base material layer 1 and the barrier layer 3 together. The adhesive used to form the adhesive layer 2 may be a two-component curing adhesive or a one-component curing adhesive. Furthermore, the adhesion mechanism of the adhesive used to form the adhesive layer 2 is not particularly limited, and may be any of chemical reaction type, solvent volatilization type, heat melting type, heat pressure type, and the like.

Specific examples of adhesive components 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; polyurethane-based adhesives; epoxy-based resins; phenol-based resins; polyamide-based resins such as nylon 6, nylon 66, nylon 12, and copolymerized polyamides; (meth)acrylic resin; polyimide resin; amino resin such as urea resin and melamine resin; rubber such as chloroprene rubber, nitrile rubber and styrene-butadiene rubber; system resin and the like. These adhesive components may be used singly or in combination of two or more. Among these adhesive components, polyurethane-based adhesives are preferred.

The thickness of the adhesive layer 2 is not particularly limited as long as it functions as an adhesive layer.

[Barrier layer 3]
In the packaging material, the barrier layer 3 is a layer that has a function of improving the strength of the packaging material and preventing water vapor, oxygen, light, and the like from entering the inside of the battery. Specific examples of the metal forming the barrier layer 3 include aluminum, stainless steel, titanium, and the like, preferably aluminum. The barrier layer 3 can be formed of, for example, a metal foil, a metal vapor deposition film, an inorganic oxide vapor deposition film, a carbon-containing inorganic oxide vapor deposition film, a film provided with these vapor deposition films, or the like. is preferred, and forming from an aluminum alloy foil is more preferred. From the viewpoint of preventing wrinkles and pinholes in the barrier layer 3 during production of the battery packaging material, the barrier layer is made of, for example, annealed aluminum (JIS H4160: 1994 A8021H-O, JIS H4160: 1994 A8079H-O, JIS H4000:2014 A8021P-O, JIS H4000:2014 A8079P-O), etc.).

The thickness of the barrier layer 3 is not particularly limited as long as it functions as a barrier layer against water vapor. .

At least one surface, preferably both surfaces, of the barrier layer 3 is preferably subjected to a chemical conversion treatment in order to stabilize adhesion and prevent dissolution and corrosion. Here, chemical conversion treatment refers to treatment for forming an acid-resistant film on the surface of the barrier layer. Examples of chemical conversion treatments include chromate treatment using chromium compounds such as chromium nitrate, chromium fluoride, chromium sulfate, chromium acetate, chromium oxalate, chromium biphosphate, chromic acid acetyl acetate, chromium chloride, and potassium chromium sulfate; phosphoric acid treatment using a phosphoric acid compound such as sodium phosphate, potassium phosphate, ammonium phosphate, polyphosphoric acid; and chemical conversion treatment. In the aminated phenol polymer, the repeating units represented by the following general formulas (1) to (4) may be contained singly or in any combination of two or more. good too.

In general formulas (1) to (4), X represents a hydrogen atom, hydroxyl group, alkyl group, hydroxyalkyl group, allyl group or benzyl group. R ¹ and R ² are the same or different and represent a hydroxyl group, an alkyl group or a hydroxyalkyl group. Examples of alkyl groups represented by X, R ¹ and R ² in general formulas (1) to (4) include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, A linear or branched alkyl group having 1 to 4 carbon atoms such as a tert-butyl group can be mentioned. Examples of hydroxyalkyl groups represented by X, R ¹ and R ² include hydroxymethyl group, 1-hydroxyethyl group, 2-hydroxyethyl group, 1-hydroxypropyl group, 2-hydroxypropyl group, 3- A linear or branched chain having 1 to 4 carbon atoms substituted with one hydroxy group such as hydroxypropyl group, 1-hydroxybutyl group, 2-hydroxybutyl group, 3-hydroxybutyl group and 4-hydroxybutyl group and a linear alkyl group. In general formulas (1) to (4), the alkyl groups and hydroxyalkyl groups represented by X, R ¹ and R ² may be the same or different. In 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 repeating units represented by formulas (1) to (4) is, for example, preferably about 500 to 1,000,000, more preferably about 1,000 to 20,000. more preferred.

In addition, as a chemical conversion treatment method for imparting corrosion resistance to the barrier layer 3, fine particles of metal oxides such as aluminum oxide, titanium oxide, cerium oxide, and tin oxide, and barium sulfate are dispersed in phosphoric acid. A method of forming a corrosion-resistant layer on the surface of the barrier layer 3 by performing a baking treatment at 150° C. or higher can be used. A resin layer obtained by cross-linking a cationic polymer with a cross-linking agent may be further formed on the corrosion-resistant layer. Examples of the cationic polymer include polyethyleneimine, an ionic polymer complex composed of a polymer containing polyethyleneimine and carboxylic acid, a primary amine-grafted acrylic resin obtained by graft-polymerizing a primary amine to an acrylic backbone, and polyallylamine. or derivatives thereof, aminophenol and the like. As these cationic polymers, only one type may be used, or two or more types may be used in combination. Examples of cross-linking agents include compounds having at least one functional group selected from the group consisting of isocyanate groups, glycidyl groups, carboxyl groups, and oxazoline groups, and silane coupling agents. As these cross-linking agents, only one type may be used, or two or more types may be used in combination.

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

As a specific method for providing the acid-resistant film, for example, at least the surface of the inner layer side of the aluminum alloy foil is first subjected to an alkali immersion method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method. , degreasing is performed by a well-known treatment method such as an acid activation method, and then metal phosphates such as chromium phosphate, titanium phosphate, zirconium phosphate, zinc phosphate and the like are applied to the degreased surface. A treatment liquid (aqueous solution) mainly composed of a mixture of metal salts, or a treatment liquid (aqueous solution) mainly composed of a non-metal phosphate salt and a mixture of these non-metal salts, or these and an acrylic resin Alternatively, a treatment liquid (aqueous solution) consisting of a mixture with a water-based synthetic resin such as phenolic resin or urethane resin is applied by a well-known coating method such as roll coating, gravure printing, or dipping to form an acid-resistant film. can be formed. For example, when treated with a chromium phosphate-based treatment solution, it becomes an acid-resistant film made of chromium phosphate, aluminum phosphate, aluminum oxide, aluminum hydroxide, aluminum fluoride, etc., and treated with a zinc phosphate-based treatment solution. In this case, an acid-resistant film composed of zinc phosphate hydrate, aluminum phosphate, aluminum oxide, aluminum hydroxide, aluminum fluoride, or the like is formed.

Further, as other specific methods for providing the acid-resistant film, for example, at least the inner layer side surface of the aluminum alloy foil is first subjected to an alkali immersion method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method, an acid An acid-resistant film can be formed by performing a degreasing treatment by a well-known treatment method such as an activation method, and then subjecting the degreased surface to a well-known anodizing treatment.

Other examples of the acid-resistant coating include phosphate-based and chromic acid-based coatings. Phosphate type includes zinc phosphate, iron phosphate, manganese phosphate, calcium phosphate, chromium phosphate and the like, and chromic acid type includes chromium chromate and the like.

Further, as another example of the acid-resistant film, by forming an acid-resistant film of phosphate, chromate, fluoride, triazinethiol compound, or the like, it is possible to improve the adhesion between the aluminum and the base layer during embossing. Prevention of delamination, prevention of dissolution and corrosion of the aluminum surface, especially dissolution and corrosion of aluminum oxide existing on the aluminum surface, and adhesion of the aluminum surface by hydrogen fluoride generated by the reaction between the electrolyte and moisture. It exhibits the effect of improving wettability, preventing delamination between the base material layer and aluminum during heat sealing, and preventing delamination between the base material layer and aluminum during press molding in the case of the embossed type. Among the substances that form an acid-resistant film, an aqueous solution composed of three components, phenolic resin, chromium (III) fluoride compound, and phosphoric acid, is applied to the surface of aluminum, followed by dry baking.

Further, the acid-resistant film includes a layer having cerium oxide, phosphoric acid or a phosphate, an anionic polymer, and a cross-linking agent that cross-links the anionic polymer, and the phosphoric acid or phosphate is the About 1 to 100 parts by mass may be blended with 100 parts by mass of cerium oxide. It is preferable that the acid-resistant film has a multi-layer structure further including a layer having a cationic polymer and a cross-linking agent for cross-linking the cationic polymer.

Further, the anionic polymer is preferably poly(meth)acrylic acid or a salt thereof, or a copolymer containing (meth)acrylic acid or a salt thereof as a main component. Moreover, the cross-linking agent is preferably at least one selected from the group consisting of a compound having a functional group such as an isocyanate group, a glycidyl group, a carboxyl group, or an oxazoline group, and a silane coupling agent.

Further, the phosphoric acid or phosphate is preferably condensed phosphoric acid or condensed phosphate.

As for 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 performed in combination. Furthermore, these chemical conversion treatments may be carried out using one compound alone, or may be carried out using a combination of two or more compounds. Among the chemical conversion treatments, chromate treatment and chemical conversion treatments in which a chromium compound, a phosphoric acid compound, and an aminated phenol polymer are combined are preferred. Among the chromium compounds, chromic acid compounds are preferred.

Specific examples of acid-resistant coatings include those containing at least one of phosphates, chromates, fluorides, and triazinethiols. An acid-resistant film containing a cerium compound is also preferred. As the cerium compound, cerium oxide is preferred.

Further, specific examples of acid-resistant coatings include phosphate-based coatings, chromate-based coatings, fluoride-based coatings, and triazinethiol compound coatings. The acid-resistant coating may be one of these, or may be a combination of multiple types. Furthermore, as the acid-resistant film, after degreasing the chemically treated surface of the aluminum alloy foil, a treatment liquid consisting of a mixture of a metal phosphate and a water-based synthetic resin, or a mixture of a non-metal phosphate and a water-based synthetic resin It may be formed of a treatment liquid consisting of

The composition of the acid-resistant coating can be analyzed using, for example, time-of-flight secondary ion mass spectrometry. By analyzing the composition of the acid-resistant coating using time-of-flight secondary ion mass spectrometry, peaks derived from at least one of Ce ⁺ and Cr ⁺ are detected, for example.

It is preferable that the surface of the aluminum alloy foil is provided with an acid-resistant film containing at least one element selected from the group consisting of phosphorus, chromium and cerium. It should be noted that the inclusion of at least one element selected from the group consisting of phosphorus, chromium and cerium in the acid-resistant coating on the surface of the aluminum alloy foil of the battery packaging material was confirmed using X-ray photoelectron spectroscopy. can do. Specifically, first, in the battery packaging material, the heat-fusible resin layer, the adhesive layer, and the like laminated on the aluminum alloy foil are physically peeled off. Next, the aluminum alloy foil is placed in an electric furnace, and organic components existing on the surface of the aluminum alloy foil are removed at about 300° C. for about 30 minutes. After that, the inclusion of these elements is confirmed using X-ray photoelectron spectroscopy of the surface of the aluminum alloy foil.

The amount of the acid-resistant film formed on the surface of the barrier layer ³ in the chemical conversion treatment is not particularly limited. About 0.5 to 50 mg, preferably about 1.0 to 40 mg, in terms of phosphorus compound, about 0.5 to 50 mg, preferably about 1.0 to 40 mg in terms of phosphorus, and aminated phenol polymer is 1.0 It is desired to be contained in a ratio of about 200 mg, preferably about 5.0 to 150 mg.

The thickness of the acid-resistant coating is not particularly limited, but is preferably about 1 nm to 10 μm, more preferably about 1 to 100 nm, from the viewpoint of the cohesion of the coating and the adhesion to the aluminum alloy foil or the heat-sealable resin layer. , and more preferably about 1 to 50 nm. The thickness of the acid-resistant film can be measured by observation with a transmission electron microscope, or a combination of observation with a transmission electron microscope and energy dispersive X-ray spectroscopy or electron beam energy loss spectroscopy.

In the chemical conversion treatment, a solution containing a compound used for forming an acid-resistant film is applied to the surface of the barrier layer by a bar coating method, a roll coating method, a gravure coating method, an immersion method, or the like. It is carried out by heating to about 200°C. In addition, before the barrier layer is subjected to the chemical conversion treatment, the barrier layer may be previously subjected to a degreasing treatment by an alkali immersion method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method, or the like. By performing the degreasing treatment in this way, it becomes possible to perform the chemical conversion treatment on the surface of the barrier layer more efficiently.

[Heat-fusible resin layer 4]
In the packaging material of the present invention, the heat-fusible resin layer 4 corresponds to the innermost layer, and is a layer that seals the battery element by thermally-bonding the heat-fusible resin layers to each other when the battery is assembled.

The resin component used for the heat-sealable resin layer 4 is not particularly limited as long as it is heat-sealable. Examples include polyolefin, cyclic polyolefin, carboxylic acid-modified polyolefin, and carboxylic acid-modified cyclic polyolefin. be done. That is, the heat-fusible resin layer 4 may contain a polyolefin skeleton, and preferably contains a polyolefin skeleton. Whether the heat-fusible resin layer 4 contains a polyolefin skeleton can be analyzed by, for example, infrared spectroscopy, gas chromatography-mass spectrometry, or the like, and the analysis method is not particularly limited. For example, when maleic anhydride-modified polyolefin is measured by infrared spectroscopy, peaks derived from maleic anhydride are detected near wavenumbers of 1760 cm-1 and 1780 cm-1. However, if the degree of acid denaturation is low, the peak may be too small to be detected. In that case, it can be analyzed by nuclear magnetic resonance spectroscopy.

Specific examples of the polyolefin include polyethylenes such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene; homopolypropylene, block copolymers of polypropylene (for example, block copolymers of propylene and ethylene), and polypropylene. terpolymers of ethylene-butene-propylene; and the like. Among these polyolefins, polyethylene and polypropylene are preferred.

The cyclic polyolefin is a copolymer of an olefin and a cyclic monomer. Examples of olefins that are constituent monomers of the cyclic polyolefin include ethylene, propylene, 4-methyl-1-pentene, butadiene, and isoprene. be done. Examples of cyclic monomers constituting the cyclic polyolefin include cyclic alkenes such as norbornene; specific examples thereof include cyclic dienes such as cyclopentadiene, dicyclopentadiene, cyclohexadiene and norbornadiene. Styrene is also included as a constituent monomer. Among these polyolefins, cyclic alkenes are preferred, and norbornene is more preferred.

The carboxylic acid-modified polyolefin is a polymer modified by block polymerization or graft polymerization of the polyolefin with a carboxylic acid. Carboxylic acids used for modification include, for example, maleic acid, acrylic acid, itaconic acid, crotonic acid, maleic anhydride, and itaconic anhydride.

The carboxylic acid-modified cyclic polyolefin is obtained by copolymerizing a part of the monomers constituting the cyclic polyolefin with α,β-unsaturated carboxylic acid or its anhydride, or by copolymerizing α,β with respect to the cyclic polyolefin. - Polymers obtained by block or graft polymerization of unsaturated carboxylic acids or their anhydrides. The carboxylic acid-modified cyclic polyolefin is the same as described above. The carboxylic acid used for modification is the same as those used for modifying the carboxylic acid-modified polyolefin.

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

The heat-fusible resin layer 4 may be formed of one resin component alone, or may be formed of a blend polymer in which two or more resin components are combined. Furthermore, the heat-fusible resin layer 4 may be formed of only one layer, or may be formed of two or more layers of the same or different resin components.

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

Moreover, the heat-fusible resin layer 4 may contain a lubricant or the like as necessary. When the heat-fusible resin layer 4 contains a lubricant, the formability of the packaging material can be enhanced. The lubricant is not particularly limited, and known lubricants can be used. Lubricants may be used singly or in combination of two or more. The content of the lubricant in the heat-fusible resin layer 4 is not particularly limited. About 0.05 to 0.15% by mass is preferred.

[Adhesion layer 5]
In the packaging material of the present invention, the adhesive layer 5 is a layer optionally provided between the barrier layer 3 and the heat-fusible resin layer 4 in order to firmly bond them.

The adhesive layer 5 is made of a resin capable of bonding the barrier layer 3 and the heat-fusible resin layer 4 together. As the resin used to form the adhesive layer 5, the same adhesives as those exemplified for the adhesive layer 2 can be used in terms of the adhesive mechanism, the types of adhesive components, and the like. As the resin used to form the adhesive layer 5, polyolefin-based resins such as polyolefins, cyclic polyolefins, carboxylic acid-modified polyolefins, and carboxylic acid-modified cyclic polyolefins exemplified for the heat-sealable resin layer 4 can also be used. . From the viewpoint of excellent adhesion between the barrier layer 3 and the heat-fusible resin layer 4, the polyolefin is preferably carboxylic acid-modified polyolefin, and particularly preferably carboxylic acid-modified polypropylene. That is, the adhesive layer 5 may contain a polyolefin skeleton, and preferably contains a polyolefin skeleton. Whether the adhesive layer 5 contains a polyolefin skeleton can be analyzed by, for example, infrared spectroscopy, gas chromatography mass spectrometry, or the like, and the analysis method is not particularly limited. For example, when maleic anhydride-modified polyolefin is measured by infrared spectroscopy, peaks derived from maleic anhydride are detected near wavenumbers of 1760 cm-1 and 1780 cm-1. However, if the degree of acid denaturation is low, the peak may be too small to be detected. In that case, it can be analyzed by nuclear magnetic resonance spectroscopy.

Furthermore, from the viewpoint of making the packaging material excellent in impact resistance while reducing the thickness of the packaging material, the adhesive layer 5 is preferably a cured product of a resin composition containing an acid-modified polyolefin and a curing agent. As the acid-modified polyolefin, the same carboxylic acid-modified polyolefin and carboxylic acid-modified cyclic polyolefin exemplified for the heat-sealable resin layer 4 can be preferably exemplified.

Moreover, the curing agent is not particularly limited as long as it cures the acid-modified polyolefin. Examples of curing agents include epoxy-based curing agents, polyfunctional isocyanate-based curing agents, carbodiimide-based curing agents, and oxazoline-based curing agents.

The epoxy-based curing agent is not particularly limited as long as it is a compound having at least one epoxy group. Examples of epoxy-based curing agents include epoxy resins such as bisphenol A diglycidyl ether, modified bisphenol A diglycidyl ether, novolac 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 polyfunctional isocyanate curing agents include isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), polymers and nurates thereof, and Mixtures and copolymers with other polymers may be mentioned.

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 curing agent, a polycarbodiimide compound having at least two carbodiimide groups is preferred.

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

From the viewpoint of enhancing the adhesion between the barrier layer 3 and the heat-fusible resin layer 4 by the adhesive layer 5, the curing agent may be composed of two or more kinds of compounds.

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

The thickness of the adhesive layer 5 is not particularly limited as long as it functions as an adhesive layer. About 5 μm can be mentioned. In the case of using the resin exemplified for the heat-fusible resin layer 4, the thickness is preferably about 2 to 50 μm, more preferably about 10 to 40 μm. In the case of a cured product of an acid-modified polyolefin and a curing agent, the thickness is preferably about 30 μm or less, more preferably about 0.1 to 20 μm, still more preferably about 0.5 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 of the present invention, for the purpose of improving design, electrolyte resistance, abrasion resistance, moldability, etc., on the base material layer 1 (with the barrier layer 3 of the base material layer 1) side) may be provided with a surface coating layer (not shown), if necessary. The surface coating layer is 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 from a two-liquid curing resin. Examples of the two-component curable resin that forms the surface coating layer include a two-component curable urethane resin, a two-component curable polyester resin, and a two-component curable epoxy resin. Additives may also be added to the surface coating layer.

Examples of the additive include fine particles having a particle size of about 0.5 nm to 5 μm. The material of the additive is not particularly limited, and examples thereof include metals, metal oxides, inorganic substances, organic substances, and the like. The shape of the additive is also not particularly limited, but examples thereof include spherical, fibrous, plate-like, amorphous, and balloon-like shapes. Specific examples of additives include talc, silica, graphite, kaolin, montmorilloid, montmorillonite, synthetic mica, hydrotalcite, silica gel, zeolite, aluminum hydroxide, magnesium hydroxide, zinc oxide, magnesium oxide, aluminum oxide, Neodymium oxide, antimony oxide, titanium oxide, cerium oxide, calcium sulfate, barium sulfate, calcium carbonate, calcium silicate, lithium carbonate, calcium benzoate, calcium oxalate, magnesium stearate, alumina, carbon black, carbon nanotubes, high melting point nylon, crosslinked acrylic, crosslinked styrene, crosslinked polyethylene, benzoguanamine, gold, aluminum, copper, nickel, and the like. These additives may be used singly or in combination of two or more. Among these additives, silica, barium sulfate, and titanium oxide are preferred from the viewpoint of dispersion stability, cost, and the like. In addition, the additive may be subjected to various surface treatments such as insulation treatment and high-dispersion treatment.

The content of the additive in the surface coating layer is not particularly limited, but is preferably about 0.05 to 1.0% by mass, more preferably about 0.1 to 0.5% by mass.

The method of forming the surface coating layer is not particularly limited, but for example, a method of coating one surface of the substrate layer 1 with a two-liquid curing resin that forms the surface coating layer can be used. When an additive is blended, the additive may be added to the two-liquid curing resin, mixed, and then applied.

The thickness of the surface coating layer is not particularly limited as long as it exhibits the above function as a surface coating layer.

3. Method for Producing Packaging Material The method for producing the 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 of the present invention is as follows. First, a layered body (hereinafter also referred to as "layered body A") is formed by laminating a substrate layer 1, an adhesive layer 2, and a barrier layer 3 in this order. Specifically, the laminate A is formed by applying an adhesive used for forming the adhesive layer 2 on the base material layer 1 or on the barrier layer 3 whose surface is chemically treated as necessary by a gravure coating method. , a dry lamination method in which the barrier layer 3 or the substrate layer 1 is laminated and the adhesive layer 2 is cured after coating and drying by a coating method such as a roll coating method.

Next, on the barrier layer 3 of the laminate A, the heat-fusible resin layer 4 is laminated. When the heat-fusible resin layer 4 is directly laminated on the barrier layer 3, the resin component constituting the heat-fusible resin layer 4 is applied onto the barrier layer 3 of the laminate A by a gravure coating method or a roll coating method. It may be applied by a method such as the following. When the adhesive layer 5 is provided between the barrier layer 3 and the heat-fusible resin layer 4, for example, (1) the adhesive layer 5 and the heat-fusible resin layer are placed on the barrier layer 3 of the laminate A. 4 (co-extrusion lamination method); (3) On the barrier layer 3 of the laminate A, an adhesive for forming the adhesive layer 5 is extruded or solution-coated, dried at a high temperature, and then baked. (4) The barrier layer 3 of the laminate A and a sheet-like film formed in advance are laminated on the adhesive layer 5 by a thermal lamination method. A method of laminating the laminate A and the heat-fusible resin layer 4 via the adhesive layer 5 while pouring the melted adhesive layer 5 between the heat-fusible resin layer 4 (sandwich lamination method), etc. is mentioned.

When the surface coating layer is provided, the surface coating layer is laminated on the surface of the substrate layer 1 opposite to the barrier layer 3 . The surface coating layer can be formed, for example, by coating the surface of the substrate layer 1 with the above-described resin for forming the surface coating layer. The order of the step of laminating the barrier layer 3 on the surface of the substrate layer 1 and the step of laminating the surface coating layer on the surface of the substrate layer 1 is not particularly limited. For example, after forming a surface coating layer on the surface of the substrate layer 1, the barrier layer 3 may be formed on the surface of the substrate layer 1 opposite to the surface coating layer.

As described above, the surface coating layer provided as required/base layer 1/adhesive layer 2 provided as required/barrier layer 3 whose surface was chemically treated as required/if required A laminated body composed of the provided adhesive layer 5 / heat-fusible resin layer 4 is formed. You may use for heat processing, such as a hot air type and a near- or far-infrared type. Conditions for such heat treatment include, for example, about 150 to 250° C. for about 1 to 5 minutes.

In the packaging material of the present invention, each layer constituting the laminate may, if necessary, improve or stabilize film formability, lamination processing, final product secondary processing (pouching, embossing) aptitude, etc. , corona treatment, blasting treatment, oxidation treatment, ozone treatment, or other surface activation treatment may be applied.

4. Uses of packaging material The packaging material of the present invention is used in a wide range of fields as a packaging body (a packaging material molded so as to accommodate the contents) for containing foods, medicines, battery elements, and the like. When the package of the present invention is used to contain contents such as foods, medicines, and battery elements, the package is used with the sealant portion of the package facing the inside (the surface in contact with the contents).

For example, when the packaging material of the present invention is used as a battery packaging material, a battery element including at least a positive electrode, a negative electrode, and an electrolyte is connected to each of the positive electrode and the negative electrode by a package body formed of the packaging material of the present invention. In a state in which the metal terminals are projected outward, the peripheral edge of the battery element is covered so as to form a flange (area where the heat-sealing resin layers contact each other), and the heat-sealing resin of the flange is By heat-sealing the layers together to provide a hermetic seal, a battery is provided in which the battery element is housed in a package.

The battery packaging material of the present invention may be used for either primary batteries or secondary batteries, preferably for secondary batteries. The type of the secondary battery is not particularly limited. Batteries, silver oxide/zinc storage batteries, metal-air batteries, polyvalent cation batteries, condensers, capacitors, and the like. Among these secondary batteries, lithium-ion batteries and lithium-ion polymer batteries can be cited as suitable targets for application of battery packaging materials.

EXAMPLES 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.

Example 1-5 and Comparative Example 1-4
<Manufacture of packaging materials>
A barrier layer made of aluminum foil (JIS H4160: 1994 A8021H-O) having both sides subjected to chemical conversion treatment was laminated on each substrate layer by a dry lamination method. Specifically, a two-component urethane adhesive (a polyol compound and an aromatic isocyanate compound) was applied to one surface of the barrier layer to form an adhesive layer (3 μm thick) on the barrier layer. Next, after laminating the adhesive layer on the barrier layer and the substrate layer, an aging treatment was performed to prepare a laminate of substrate layer/adhesive layer/barrier layer. In addition, the chemical conversion treatment of the aluminum foil used as the barrier layer was carried out by roll-coating a treatment solution consisting of phenolic resin, chromium fluoride compound, and phosphoric acid so that the coating amount of chromium was 10 mg/m ² (dry mass). It was applied to both sides of an aluminum foil according to the method and baked.

Next, in Examples 1, 2, 5 and Comparative Examples 1, 2, carboxylic acid-modified polypropylene (located on the barrier layer side) and random polypropylene (innermost layer) were co-extruded on the barrier layer of the laminate. Thus, the adhesive layer/heat-fusible resin layer was laminated on the barrier layer. Next, the resulting laminate was heated to obtain a packaging material in which a substrate layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order. In addition, in the base material layer used in Example 5, the PET (thickness of 12 μm) and the nylon (thickness of 15 μm) are adhered with a two-component urethane adhesive (thickness of 3 μm).

On the other hand, in Examples 3 and 4 and Comparative Examples 3 and 4, a solution obtained by mixing a carboxylic acid-modified polypropylene and an epoxy curing agent was applied onto the barrier layer of the laminate and dried. Further, an unstretched polypropylene film (innermost layer) was laminated thereon. The content of the curing agent was set to 5% by mass with respect to the total solid mass after drying. Next, the resulting laminate was aged to obtain a packaging material in which a substrate layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-fusible resin layer were laminated in this order.

The laminated structure and the thickness of each layer in each example and comparative example are as follows.
Example 1: Nylon (25 µm)/adhesive layer (3 µm)/aluminum foil (40 µm)/carboxylic acid-modified polypropylene (23 µm)/polypropylene (23 µm)
Example 2: Nylon (25 μm)/adhesive layer (3 μm)/aluminum foil (25 μm)/carboxylic acid-modified polypropylene (14 μm)/polypropylene (10 μm)
Example 3: Nylon (25 µm)/adhesive layer (3 µm)/aluminum foil (25 µm)/cured product of carboxylic acid-modified polypropylene and curing agent (2 µm)/unstretched polypropylene (25 µm)
Example 4: Nylon (25 µm)/adhesive layer (3 µm)/aluminum foil (35 µm)/cured product of carboxylic acid-modified polypropylene and curing agent (2 µm)/unstretched polypropylene (30 µm)
Example 5: PET (12 μm)/adhesive (3 μm)/nylon (15 μm)/adhesive layer (3 μm)/aluminum foil (40 μm)/carboxylic acid-modified polypropylene (40 μm)/polypropylene (40 μm)

Comparative Example 1: PET (12 μm)/adhesive layer (3 μm)/aluminum foil (25 μm)/carboxylic acid-modified polypropylene (14 μm)/polypropylene (10 μm)
Comparative Example 2: Nylon (15 μm)/adhesive layer (3 μm)/aluminum foil (35 μm)/carboxylic acid-modified polypropylene (20 μm)/polypropylene (15 μm)
Comparative Example 3: PET (12 μm)/adhesive layer (3 μm)/aluminum foil (25 μm)/cured product of carboxylic acid-modified polypropylene and curing agent (2 μm)/unstretched polypropylene (25 μm)
Comparative Example 4: Nylon (15 μm)/adhesive layer (3 μm)/aluminum foil (35 μm)/cured product of carboxylic acid-modified polypropylene and curing agent (2 μm)/unstretched polypropylene (30 μm)

<Breaking energy of laminate>
For each packaging material obtained above, the breaking energy per unit width of 1 m in MD and TD was measured when a tensile test was performed under the following test conditions for each packaging material in MD and TD. Obtain the data of the "test force-displacement curve", save the data in csv file format, and use the spreadsheet software (Excel (registered trademark) of Microsoft Corporation) until the laminate breaks. Calculated by integrating the data. At this time, the breaking energy per m width of each packaging material was converted (divided by 0.015) and calculated using the spreadsheet software. Then, the breaking energy per unit width of 1 m in MD and the breaking energy per unit width of 1 m in TD were totaled. Five packaging materials to be measured were prepared, and the average of the three breaking energy values of the five samples, excluding the maximum and minimum values, was taken as the breaking energy of the laminate. Table 1 shows the results.
(Test condition)
・Test speed 50mm/min
・ Width of test piece: 15 mm
・ Length of test piece: 100 mm
・Distance between gauge points: 30mm

For reference, FIG. 4 shows the test force-displacement curve obtained in the tensile test (MD) of the packaging material of Comparative Example 2. The part where the data of the test force-displacement curve is integrated is, for example, as shown in the schematic diagram of FIG. It corresponds to the area of the hatched portion in FIG.

<Penetration strength of laminate>
For each packaging material obtained above, the puncture strength was measured from the substrate layer side by a method conforming to JIS Z1707:1995. Imada's ZP-50N (force gauge) and MX2-500N (measuring stand) were used as devices for measuring the puncture strength. Table 1 shows the results.

<Total Penetration Energy of Laminate>
For each packaging material obtained above, the total penetration energy was measured from the substrate layer side by a method conforming to JIS K7124-2:1999. A falling weight type graphic impact tester (manufactured by Toyo Seiki Co., Ltd.) was used as a measuring device. The measurement conditions were as follows: hammer weight 6.4 kg, drop height 300 mm, sample clamp diameter 40 mmφ, hammer diameter 12.7 mmφ, hammer shape hemispherical. Table 1 shows the results.

<Penetration strength of each layer>
Prepare the base material layer, the barrier layer, and the laminate of the adhesive layer and the heat-fusible resin layer used in the production of the above packaging material, and apply them to the base material by a method conforming to the provisions of JIS Z1707:1995. The puncture strength was measured from the layer side. Imada's ZP-50N (force gauge) and MX2-500N (measuring stand) were used as devices for measuring the puncture strength. Table 1 shows the results.

<Impact resistance evaluation of packaging materials>
After cutting each packaging material obtained above to 90 mm × 150 mm, it was cut into a mold (female mold) with a diameter of 32 mm × 55 mm and a corresponding molding mold (male mold) at 0.9 MPa. It was cold-formed to a depth of 0.0 mm and a recess was formed in the central portion. A PET resin having a width of 30 mm, a length of 52 mm, and a thickness of 3 mm was placed in the recess as a pseudo battery element. Next, the unmolded portion of the molded product was folded so that the sealant surfaces faced each other, and the peripheral portion was heat-sealed to fabricate a pseudo battery. The heat sealing conditions were 190° C., surface pressure of 1.0 MPa, and 3 seconds.

The molded article was then placed on a rigid flat surface and a round bar with a diameter of 16 mm was placed in the center of the molded article across the molded article. Next, a weight of 9.1 kg was dropped onto the round bar from a height of 610 mm. After the drop, the molded article that was not cut was evaluated as having excellent impact resistance (A), and the molded article that was cut was evaluated as having poor impact resistance (C). Table 1 shows the results.

As is clear from the results shown in Table 1, the breaking energy per unit width of 1 m calculated from the test force-displacement curve measured when the tensile test was performed under the above test conditions was The packaging material of Examples 1 to 5, wherein the total of one direction (MD) perpendicular to the thickness direction and the other direction (TD) perpendicular to the one direction and the thickness direction of the laminate is 400 J or more. It can be seen that is excellent in impact resistance. On the other hand, it can be seen that the packaging materials of Comparative Examples 1-4, in which the total breaking energy is less than 400 J, are inferior to those of Examples 1-5 in impact resistance.

1 base material layer 2 adhesive layer 3 barrier layer 4 heat-fusible resin layer 5 adhesive layer

Claims (20)

Consists of a laminate comprising at least a substrate layer, a barrier layer, and a heat-fusible resin layer in this order,
The laminate has a thickness of 160 μm or less,
The laminate is measured when a tensile test is performed under the following test conditions, and the breaking energy per unit width of 1m calculated from the test force-displacement curve is perpendicular to the thickness direction of the laminate. A packaging material having a total of 400 J or more in one direction and the other direction perpendicular to said one direction and the thickness direction of said laminate.
(Test condition)
Test speed: 50mm/min
Width of test piece: 15 mm
Length of test piece: 100 mm
Gauge distance: 30 mm The packaging material according to claim 1, wherein the one direction is the MD of the laminate and the other direction is the TD of the laminate. The packaging material according to claim 1 or 2, wherein the laminate has a puncture strength of 23 N or more measured from the base layer side by a method conforming to JIS Z1707:1995. According to the provisions of JIS K7124-2: 1999, the laminate has a total penetration energy of 1.4 J or more measured from the base material layer side under the following measurement conditions. A packaging material according to any one of the preceding claims.
(Measurement condition)
Hammer weight: 6.4kg
Drop height: 300mm
Sample clamp diameter: 40mmφ
Hammer diameter: 12.7mm
Hammer shape: hemispherical The packaging material according to any one of claims 1 to 4, wherein the total breaking energy of the MD and TD of the laminate is 500 J or more. The packaging material according to any one of claims 1 to 5, wherein the barrier layer is made of at least one metal foil selected from the group consisting of aluminum alloy, stainless steel and titanium. The packaging material according to any one of claims 1 to 6, wherein the base material layer contains at least one of polyester and polyamide. Claims 1 to 7, wherein the substrate layer has 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, or a multilayer structure in which a plurality of polyester films are laminated. The packaging material according to any one of . The packaging material according to any one of claims 1 to 8 , wherein two or more types of lubricant are attached to the surface of the base layer, or the base layer contains two or more types of lubricant. The packaging material according to any one of claims 1 to 9, wherein the heat-fusible resin layer is composed of a resin containing a polyolefin skeleton. The heat-sealable resin layer according to any one of claims 1 to 10, wherein the heat-sealable resin layer contains at least one selected from the group consisting of polyolefins, cyclic polyolefins, carboxylic acid-modified polyolefins, and carboxylic acid-modified cyclic polyolefins. packaging materials. The packaging material according to any one of claims 1 to 11, wherein the heat-fusible resin layer is formed of a blend polymer in which two or more resins are combined. The packaging material according to any one of claims 1 to 12, wherein the heat-fusible resin layer is formed of two or more layers of the same or different resin components. The packaging material according to any one of claims 1 to 13, wherein the heat-fusible resin layer contains two or more lubricants. The heat-sealable resin layer comprises at least two selected from the group consisting of saturated fatty acid amides, unsaturated fatty acid amides, substituted amides, methylolamides, saturated fatty acid bisamides, unsaturated fatty acid bisamides, fatty acid ester amides and aromatic bisamides. The packaging material according to any one of claims 1 to 14, comprising The packaging material according to any one of claims 1 to 14, which is used for housing battery elements. A battery, wherein a battery element comprising at least a positive electrode, a negative electrode, and an electrolyte is housed in a package formed of the packaging material according to any one of claims 1 to 16. obtaining a packaging material composed of a laminate comprising at least a substrate layer, a barrier layer, and a heat-fusible resin layer in this order;
The laminate has a thickness of 160 μm or less,
The laminate is measured when a tensile test is performed under the following test conditions, and the breaking energy per unit width of 1m calculated from the test force-displacement curve is perpendicular to the thickness direction of the laminate. A method for producing a packaging material, wherein the total length of one direction and the other direction perpendicular to the one direction and the thickness direction of the laminate is 400 J or more.
(Test condition)
Test speed: 50mm/min
Width of test piece: 15 mm
Length of test piece: 100mm
Gauge distance: 30 mm An adhesive layer is provided between the barrier layer and the heat-fusible resin layer,
The adhesive layer and the heat-fusible resin layer are formed by a coextrusion lamination method, a thermal lamination method, an adhesive for forming the adhesive layer on the barrier layer, and a sheet in advance on the adhesive layer. 19. The method for producing a packaging material according to claim 18, wherein the heat-fusible resin layer formed into a shape is laminated by a thermal lamination method or formed by a sandwich lamination method. An adhesive layer is provided between the barrier layer and the heat-fusible resin layer,
20. The method of manufacturing a packaging material according to claim 18, wherein the heat-fusible resin layer is formed of two or more layers of the same or different resin components.

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