JP2022000854A - Packaging material and battery - Google Patents

Abstract

To provide a packaging material having excellent impact resistance.SOLUTION: A packaging material is composed of a laminate having at least a base material layer, a barrier layer, and a heat-sealing resin layer in this order, and in the laminate, the breaking energy per unit width of 1 m calculated from the curve of test force-displacement amount measured when the tensile test is performed under the following test conditions is 400 J or more in total of one direction which is the vertical direction to the thickness direction of the laminate and the other directions which is vertical direction to the one direction and the thickness direction of the laminate.SELECTED DRAWING: None

Description

The present invention relates to packaging materials and batteries.

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 / a barrier layer / a heat-sealing resin layer is sequentially laminated is known, and by heat-sealing the heat-sealing resin layers with each other, the heat-sealing resin layers are heat-sealed. The contents can be sealed.

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

In these various packaging materials, a strong impact may be applied from the outside during transportation and the like, and high impact resistance is required. On the other hand, in recent years, from the viewpoint of making products thinner and lighter, there is a demand for further thinning of packaging materials. However, when the thickness of the packaging material becomes thin, there is a problem that the impact resistance is lowered.

Japanese Unexamined Patent Publication No. 2008-287971

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

The present inventors have made diligent studies to solve the above problems. As a result, it is measured when a tensile test is performed on the laminated body under the following test conditions in a packaging material composed of a laminated body having at least a base material layer, a barrier layer, and a heat-sealing resin layer in this order. The breaking energy per 1 m of unit width calculated from the curve of "test force-displacement amount" is one direction perpendicular to the thickness direction of the laminated body, and one direction perpendicular to the one direction and the thickness direction of the laminated body. It has been found that a packaging material having excellent impact resistance can be obtained by having a total of 400 J or more in other directions. The present invention has been completed by further studies based on these findings.
(Test condition)
Test speed: 50 mm / min
Width of test piece: 15 mm
Specimen length: 100 mm
Distance between gauge points: 30 mm

That is, the present invention provides packaging materials and batteries according to the following aspects.
Item 1. It is composed of a laminate having at least a base material layer, a barrier layer, and a heat-sealing resin layer in this order.
In the laminated body, the breaking energy per 1 m of unit width calculated from the curve of test force-displacement amount measured when the tensile test is performed under the following test conditions is perpendicular to the thickness direction of the laminated body. A packaging material having a total of 400 J or more in one direction and the other directions perpendicular to the one direction and the thickness direction of the laminate.
(Test condition)
Test speed: 50 mm / min
Width of test piece: 15 mm
Specimen length: 100 mm
Distance between gauge points: 30 mm
Item 2. Item 2. The packaging material according to Item 1, wherein one direction is the MD of the laminated body and the other direction is the TD of the laminated body.
Item 3. Item 2. The packaging material according to Item 1 or 2, wherein the laminate has a piercing strength of 23 N or more measured from the base material layer side by a method according to JIS Z1707: 1995.
Item 4. The laminated body complies with the provisions of JIS K7124-2: 1999, and the total penetration energy measured from the base material layer side under the following measurement conditions is 1.4 J or more, whichever of Items 1 to 3. Packaging material listed in Crab.
(Measurement condition)
Hammer weight: 6.4 kg
Drop height: 300 mm
Sample clamp diameter: 40 mmφ
Hammer diameter: 12.7 mm
Hammer shape: Hemispherical term 5. Item 2. 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 2. The packaging material according to any one of Items 1 to 5, wherein the barrier layer is made of aluminum foil.
Item 7. Item 6. The packaging material according to any one of Items 1 to 6, which is used for accommodating a battery element.
Item 8. 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 packaging material according to any one of Items 1 to 7.

According to the present invention, at least in a packaging material composed of a laminate having a base material layer, a barrier layer, and a heat-sealing resin layer in this order, measurement is performed when a tensile test is performed on the laminate under the above-mentioned test conditions. The breaking energy per unit width of 1 m calculated from the "test force-displacement amount" curve is one direction perpendicular to the thickness direction of the laminated body, the one direction, and the thickness direction of the laminated body. Is 400 J or more in total in the other directions in the vertical direction, so that a packaging material having excellent impact resistance can be provided.

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. It is a curve (MD) of the test force-displacement amount obtained in the tensile test of the packaging material of Comparative Example 2. It is a schematic diagram which showed the part where the data of the curve of the test force-displacement amount was integrated.

The packaging material of the present invention is composed of a laminate having at least a base material layer, a barrier layer, and a heat-sealing resin layer in this order, and the laminate is subjected to a tensile test under the following test conditions. The breaking energy per 1 m of unit width calculated from the curve of test force-displacement amount measured in 1 is one direction perpendicular to the thickness direction of the laminated body, the one direction, and the thickness direction of the laminated body. Is characterized by having a total of 400 J or more in the other directions in the vertical direction. Hereinafter, the packaging material of the present invention will be described in detail.
(Test condition)
Test speed: 50 mm / min
Width of test piece: 15 mm
Specimen length: 100 mm
Distance between gauge points: 30 mm

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

1. 1. Laminated structure and physical properties of packaging material As shown in FIG. 1, for example, the packaging material of the present invention is composed of a laminate in which at least a base material layer 1, a barrier layer 3, and a heat-sealing resin layer 4 are sequentially laminated. Will be done. In the packaging material of the present invention, the base material layer 1 is on the outermost layer side, and the heat-sealing resin layer 4 is on the innermost layer. That is, at the time of assembling the battery, the heat-sealing resin layers 4 located on the peripheral edge of the battery element are heat-sealed to seal the battery element, whereby the battery element is sealed.

In the packaging material of the present invention, for example, as shown in FIG. 2, an adhesive layer 2 is provided between the base material layer 1 and the barrier layer 3 as needed for the purpose of enhancing their adhesiveness. May be good. Further, in the packaging material of the present invention, for example, as shown in FIG. 3, an adhesive layer 5 is provided between the barrier layer 3 and the heat-sealing resin layer 4 for the purpose of enhancing their adhesiveness, if necessary. It may be provided.

The laminate constituting the packaging material of the present invention has a breaking energy per unit width of 1 m calculated from a curve of "test force-displacement amount" measured when a tensile test is performed under the above test conditions. The thickness direction of the laminate (that is, the stacking direction of the laminate) is one direction in the vertical direction, and the other direction that is perpendicular to the one direction and the thickness direction of the laminate (that is, the other direction is the one. It is a total of 400 J or more in the direction perpendicular to the direction and also in the direction perpendicular to the thickness direction of the laminated body). 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 laminated body, and the other direction is the TD (Transverse Direction) of the laminated body. Is preferable. That is, the breaking energy per 1 m of unit width calculated from the curve of "test force-displacement amount" measured when the tensile test is performed under the above test conditions is the MD which is the flow direction of the laminated body. The total of TD in the vertical direction is preferably 400 J or more. In the present invention, the tensile test means a test of tensile properties.

Further, 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, and the packaging material can be used. 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 1000 J, about 400 to 800 J, about 450 to 1000 J, about 450 to 800 J, about 500 to 1000 J, and about 500 to 800 J.

In the packaging material, MD and TD can usually be discriminated in the manufacturing process of the barrier layer described later. For example, when the barrier layer is made of aluminum foil, linear streaks, so-called rolling marks, are formed on the surface of the aluminum foil in the rolling direction (RD: Rolling Direction) 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. Further, in the manufacturing process of the laminated body, since the MD of the laminated body and the RD of the aluminum foil usually match, the surface of the aluminum foil of the laminated body is observed and the rolling direction (RD) of the aluminum foil is specified. Thereby, the MD of the laminated body can be specified. Further, since the TD of the laminated body is in the direction perpendicular to the MD of the laminated body, the TD of the laminated body 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 a tensile test under the test conditions in the one direction and the other direction of the laminate, respectively. The data of the test force-displacement amount curve measured at the time of the above is acquired, the data is saved in the csv file format, and the laminated body is used with spreadsheet software (Excel (registered trademark) of Microsoft Corporation). It is calculated by integrating the data until it breaks. At this time, it is calculated by converting it into the breaking energy per 1 m width of each packaging material (dividing by 0.015) by 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. The time when the laminated body is broken means the time when the test piece is broken. Five packaging materials to be measured are prepared for each, and for example, the average of three values excluding the maximum value and the minimum value among the breaking energy values for the five samples is used as the breaking energy of the laminated body. .. Even when five samples cannot be prepared, it is preferable to use the average measured by the number of measurable samples. Further, in the tensile test, a commercially available tensile tester can be used.

Further, 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 on the base material layer 1 side by a method in accordance with the provisions of JIS Z1707: 1995. The lower limit of the piercing strength measured from the above is preferably about 23 N or more, more preferably about 24 N or more, still more preferably about 26 N or more, and the upper limit is from the viewpoint of suitably molding the packaging material. Is preferably about 50 N or less, more preferably about 40 N or less. The range of the piercing strength is preferably about 23 to 50 N, about 23 to 40 N, about 24 to 50 N, about 24 to 40 N, about 26 to 50 N, and about 26 to 40 N.

Further, 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 comprises the base material layer 1, the barrier layer 3, and the heat-sealing resin described later. For each layer 4, the total value of the piercing strength measured in accordance with the provisions of JIS Z1707: 1995 is preferably 23 N or more, preferably 23 to 50 N, and 23 to 40 N. It is more preferable to have. When the laminate constituting the packaging material of the present invention has only the heat-sealing resin layer 4 arranged inside the barrier layer 3 as shown in FIGS. 1 and 2, the heat-sealing resin layer The piercing strength of the above is the piercing strength measured only for the heat-sealing resin layer 4, but as shown in FIG. 3 described later, the adhesive layer 5 and the heat-sealing property are inside the barrier layer 3. When the resin layer 4 is arranged, the piercing strength is the piercing strength measured for the laminated body of the adhesive layer 5 and the heat-sealing 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 is a base material under the following measurement conditions. The lower limit of the total penetration energy measured from the layer 1 side is preferably about 1.4 J or more, more preferably 1.5 J or more, and the upper limit is set from the viewpoint of suitably molding the packaging material. It is preferably 5.0 J or less, and 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: 6.4 kg
Drop height: 300 mm
Sample clamp diameter: 40 mmφ
Hammer diameter: 12.7 mm
Hammer shape: hemispherical

Regarding the impact resistance of the packaging material of the present invention, for example, the packaging material breaks when a strong impact is applied from the outside in a state where the heat-sealing resin layers 4 are heat-sealed to each other and the contents are sealed. It is evaluated by whether or not the contents are exposed to the outside. For example, in a conventional battery sealed in a metal can, which is widely used, impact resistance is evaluated by a method in accordance with the provisions of UL1642. When the packaging material of the present invention is, for example, a material used for accommodating a battery element (that is, a packaging material for a battery), it passes the impact resistance evaluated by a method in accordance with the provisions of UL1642 (smoke generation, It is preferable that the battery does not ignite.

The thickness of the laminate constituting the packaging material of the present invention is not particularly limited, but the upper limit is preferably about 160 μm or less from the viewpoint of making the thickness as thin as possible while ensuring excellent impact resistance. 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 laminated body 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. According to the present invention, excellent impact resistance can be exhibited 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. Therefore, the packaging material of the present invention can contribute to the improvement of the energy density of the battery.

2. 2. Each layer forming the packaging material [base material layer 1]
In the packaging material 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 insulating properties. 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 polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, polycarbonate, and ethylene terephthalate as repeating units of copolymerized polyester and butylene terephthalate. 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 / sebacate), polybutylene (terephthalate / decantycarboxylate), 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 is less likely to cause whitening or the like 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 66; terephthalic acid and / or isophthalic acid. Nylon 6I, Nylon 6T, Nylon 6IT, Nylon 6I6T (I stands for isophthalic acid, T stands for terephthalic acid) and other hexamethylenediamine-isophthalic acid-terephthalic acid copolymerized polyamides, polymethoxylylenazi Aroma-containing polyamide such as pamide (MXD6); alicyclic polyamide such as polyaminomethylcyclohexyl adipamide (PACM6); further, a lactam component and an isocyanate component such as 4,4'-diphenylmethane-diisocyanate are copolymerized. Examples thereof include polyesteramide copolymers and polyetheresteramide copolymers, which are copolymers of the polyamides and copolymerized polyamides with 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.

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

Among these, examples of the resin film forming the base material layer 1 include nylon and polyester, more preferably biaxially stretched nylon, biaxially stretched polyester, and particularly preferably biaxially stretched nylon.

The base material layer 1 can be laminated (multilayer structure) with at least one of resin films and coatings of different materials in order to improve pinhole resistance and insulation when used as a battery package. be. Specific examples thereof include a multilayer structure in which a polyester film and a nylon film are laminated, a multilayer structure in which a plurality of nylon films are laminated, and a multilayer structure in which a plurality of layers of a polyester film are laminated. When the base material layer 1 has a multilayer structure, a laminate of a biaxially stretched nylon film and a biaxially stretched polyester film, a laminate in which a plurality of biaxially stretched nylon films are laminated, and a laminate in which a plurality of biaxially stretched polyester films are laminated. The body is preferred. Further, since the biaxially stretched polyester is difficult to discolor when the electrolytic solution adheres to the surface, for example, the base material layer 1 has a multilayer structure of a biaxially stretched nylon film and a biaxially stretched polyester film. The base material layer 1 is preferably a laminate having biaxially stretched nylon and biaxially stretched polyester in this order from the barrier layer 3 side. When the base material layer 1 has a multilayer structure, the thickness of each layer is preferably about 3 to 25 μm.

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 heat-melted state such as a coextrusion method, a sandwich laminating method, and a thermal laminating method can be mentioned. When adhering via an adhesive, the adhesive used may be a two-component curable adhesive or a one-component curable adhesive. Further, the adhesive mechanism of the adhesive is not particularly limited, and may be any of a chemical reaction type, a solvent volatile type, a heat melting type, a thermal pressure type, an ultraviolet curable type, an electron beam curable type 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, it is preferable that the lubricant adheres to the surface of the base material layer 1. The lubricant is not particularly limited, but an amide-based lubricant is preferable. Specific examples of the amide-based lubricant include saturated fatty acid amides, unsaturated fatty acid amides, substituted amides, methylol amides, saturated fatty acid bisamides, and unsaturated fatty acid bisamides. Specific examples of the saturated fatty acid amide include lauric acid amide, palmitic acid amide, stearic acid amide, behenic acid amide, hydroxystearic acid amide and the like. Specific examples of unsaturated fatty acid amides include oleic acid amides and erucic acid amides. Specific examples of the substituted amide include N-oleyl palmitate amide, N-stearyl stearyl amide, N-stearyl oleate amide, N-oleyl stealic acid amide, N-stearyl erucate amide and the like. Further, specific examples of trimethylolamide include trimethylolstearic acid amide. Specific examples of the saturated fatty acid bisamide include methylene bisstearic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide, ethylene bisstearic acid amide, ethylene bishydroxystearic acid amide, ethylene bisbechenic acid amide, and hexamethylene bisstea. Examples thereof include acid amides, hexamethylene bisbechenic acid amides, hexamethylene hydroxystearic acid amides, N, N'-distealyl adipic acid amides, N, N'-distearyl sebasic acid amides and the like. Specific examples of unsaturated fatty acid bisamides include ethylene bisoleic acid amides, ethylene biserukaic acid amides, hexamethylene bisoleic acid amides, N, N'-diorail adipic acid amides, and N, N'-diorail sevacinic acid amides. And so on. Specific examples of the fatty acid ester amide include stearoamide ethyl stearate and the like. Specific examples of the aromatic bisamide include m-xylylene bisstearic acid amide, m-xylylene bishydroxystearic acid amide, and N, N'-distearylisophthalic acid amide. The lubricant may be used alone or in combination of two or more.

The content of the lubricant in the base material layer 1 is not particularly limited, and is preferably about 0.01 to 0.2% by mass, more preferably 0, from the viewpoint of improving the moldability and the insulating property of the electronic packaging material. .05 to 0.15% by mass is mentioned.

The thickness of the base material 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 thereof is preferably about 75 μm or less, more preferably about 50 μm or less. The thickness range of the base material 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 the present invention, when the base material layer 1 has a multi-layer structure bonded by an adhesive, the thickness of the base material layer 1 does not include the thickness of the adhesive.

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

The adhesive layer 2 is formed by an adhesive capable of adhering the base material layer 1 and the barrier layer 3. The adhesive used to form the adhesive layer 2 may be a two-component curable adhesive or a one-component curable adhesive. Further, the adhesive mechanism used for forming the adhesive layer 2 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 and the like.

Specific examples of the adhesive component that can be used to form the adhesive layer 2 include polyester resins such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, polycarbonate, and copolymerized polyester; Polyether-based adhesives; Polyethylene-based adhesives; Epoxy resins; Phenolic resins; Polyethylene-based resins such as nylon 6, nylon 66, nylon 12, and copolymerized polyamides; Polyethylenes 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 system resins. These adhesive components may be used alone or in combination of two or more. Among these adhesive components, a polyurethane-based adhesive is preferable.

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

[Barrier layer 3]
In the packaging material, the barrier layer 3 is a layer having 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 constituting 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, and is formed of a metal foil. Is preferable, and it is more preferable to form it with an aluminum alloy foil. From the viewpoint of preventing wrinkles and pinholes from being generated in the barrier layer 3 during the manufacture of the battery packaging material, the barrier layer may be, for example, annealed aluminum (JIS H4160: 1994 A8021H-O, JIS H4160: It is more preferably formed from a soft aluminum alloy foil such as 1994 A8079H-O, JIS H4000: 2014 A8021P-O, JIS H4000: 2014 A8079P-O).

The thickness of the barrier layer 3 is not particularly limited as long as it functions as a barrier layer such as water vapor, but for example, it is preferably about 100 μm or less, more preferably about 10 to 100 μm, and further preferably about 10 to 80 μm. ..

Further, it is preferable that at least one surface, preferably both sides, of the barrier layer 3 is subjected to chemical conversion treatment 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 the barrier layer. The chemical conversion treatment includes, for example, chromate treatment using a chromium compound such as chromium nitrate, chromium fluoride, chromium sulfate, chromium acetate, chromium oxalate, chromium bicarbonate, acetylacetate chromate, chromium chloride, potassium sulfate chromium; phosphorus. Phosphoric acid treatment with a phosphoric acid compound such as sodium acid, potassium phosphate, ammonium phosphate, polyphosphoric acid; for an aminoated phenol polymer having repeating units represented by the following general formulas (1) to (4). Examples include the chemical conversion process. In the amination 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. Further, R ¹ and R ² are the same or different, respectively, and represent a hydroxyl group, an alkyl group, or a hydroxyalkyl group. 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 or more and 4 or less carbon atoms such as a tert-butyl group. Examples of the hydroxyalkyl group 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 or more and 4 or less 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. A state 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 from each other. 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 aminoated phenol polymer having the repeating unit represented by the general formulas (1) to (4) is preferably, for example, about 5 to 1,000,000, and preferably about 1,000 to 20,000. More preferred.

Further, as a chemical conversion treatment method for imparting corrosion resistance to the barrier layer 3, a material in which metal oxides such as aluminum oxide, titanium oxide, cerium oxide and tin oxide and fine particles of barium sulfate are dispersed in phosphoric acid is coated. 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 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 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 kind may be used, or two or more kinds may be used in combination.

Further, as a chemical conversion treatment method for imparting corrosion resistance to the barrier layer 3, a material in which metal oxides such as aluminum oxide, titanium oxide, cerium oxide and tin oxide and fine particles of barium sulfate are dispersed in phosphoric acid is coated. 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. Further, a resin layer obtained by cross-linking a cationic polymer with a cross-linking agent may be further formed on the acid-resistant film. 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 kind may be used, or two or more kinds may be used in combination.

As a method for specifically providing the acid-resistant film, for example, as an example, at least the inner layer side surface of the aluminum alloy foil is first subjected to an alkali dipping method, an electrolytic cleaning method, an acid cleaning method, or an electrolytic acid cleaning method. , The degreasing treatment is performed by a well-known treatment method such as an acid activation method, and then the degreased surface is subjected to a phosphoric acid metal salt such as a chromium phosphate salt, a titanium phosphate salt, a zirconium phosphate salt or a zinc phosphate salt, and these. A treatment solution (aqueous solution) containing a mixture of metal salts as a main component, or a treatment solution (aqueous solution) containing a mixture of a non-metal phosphate and these non-metal salts as a main component, or an acrylic resin with these. By applying a treatment liquid (aqueous solution) consisting of a mixture with a water-based synthetic resin such as a phenol-based resin or a urethane-based resin by a well-known coating method such as a roll coating method, a gravure printing method, or a dipping method, an acid-resistant film is formed. Can be formed. For example, when treated with a chromium phosphate-based treatment liquid, an acid-resistant film composed of chromium phosphate, aluminum phosphate, aluminum oxide, aluminum hydroxide, aluminum fluoride, etc. is formed and treated with a zinc phosphate salt-based treatment liquid. If so, the acid-resistant film is made of zinc phosphate hydrate, aluminum phosphate, aluminum oxide, aluminum hydroxide, aluminum fluoride and the like.

Further, as another example of the specific method 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 alkaline dipping method, an electrolytic cleaning method, an acid cleaning method, an electrolytic acid cleaning method, and 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 performing a well-known anodizing treatment on the degreased surface.

Further, as another example of the acid resistant film, a phosphate-based film or a chromic acid-based film can be mentioned. Examples of the phosphate system include zinc phosphate, iron phosphate, manganese phosphate, calcium phosphate, chromium phosphate and the like, and examples of the chromic acid system include chromium chromate and the like.

Further, as another example of the acid-resistant film, by forming an acid-resistant film such as a phosphate, a chromate, a fluoride, and a triazinethiol compound, the aluminum and the base material layer at the time of embossing are formed. Prevention of delamination, hydrogen fluoride generated by the reaction between the electrolyte and moisture prevents the aluminum surface from melting and corroding, especially the aluminum oxide present on the aluminum surface from melting and corroding, and adhering to the aluminum surface. It improves the property (wetting property) and shows the effect of preventing the corrosion between the base material layer and aluminum during heat sealing, and the effect of preventing the delamination between the base material layer and aluminum during press molding in the embossed type. Among the substances forming an acid-resistant film, an aqueous solution composed of three components of a phenol resin, a chromium (III) fluoride compound, and phosphoric acid is applied to the aluminum surface, and the drying and baking treatment is good.

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

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

Further, it is preferable that the phosphoric acid or phosphate is condensed phosphoric acid or condensed phosphate.

As the chemical conversion treatment, only one type of chemical conversion treatment may be performed, or two or more types of chemical conversion treatment may be performed in combination. 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 treatment and chemical conversion treatment in which a chromium compound, a phosphoric acid compound, and an amination phenol polymer are combined are preferable. Among the chromium compounds, a chromic acid compound is preferable.

Specific examples of the acid-resistant film include those containing at least one of phosphate, chromate, fluoride, and triazinethiol. Further, an acid resistant film containing a cerium compound is also preferable. As the cerium compound, cerium oxide is preferable.

Specific examples of the acid-resistant film include a phosphate-based film, a chromate-based film, a fluoride-based film, and a triazinethiol compound film. The acid-resistant film may be one of these or a combination of a plurality of types. Further, as the acid-resistant film, after degreasing the chemical conversion-treated surface of the aluminum alloy foil, a treatment liquid consisting of a mixture of a metal phosphate salt and an aqueous synthetic resin, or a mixture of a non-metal phosphate salt and an aqueous synthetic resin is used. It may be formed of a treatment liquid made of.

The composition of the acid-resistant film can be analyzed by using, for example, a time-of-flight secondary ion mass spectrometry method. Analysis of the composition of the acid-resistant film using time-of-flight secondary ion mass spectrometry detects, for example, peaks derived from at least one of ^{Ce +} and Cr ^+.

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 was confirmed by X-ray photoelectron spectroscopy that the acid-resistant film on the surface of the aluminum alloy foil of the battery packaging material contained at least one element selected from the group consisting of phosphorus, chromium and cerium. can do. Specifically, first, in the battery packaging material, the heat-sealing 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 the organic components present on the surface of the aluminum alloy foil are removed at about 300 ° C. for about 30 minutes. Then, X-ray photoelectron spectroscopy on the surface of the aluminum alloy foil is used to confirm that these elements are contained.

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, but for example, in the case of performing the above chromate treatment, the chromium compound is chromium per ^{1 m 2 of the surface of the barrier layer 3.} Conversion is about 0.5 to 50 mg, preferably about 1.0 to 40 mg, phosphorus compound is about 0.5 to 50 mg, preferably about 1.0 to 40 mg, and aminated phenol polymer is 1.0. It is desirable that it is contained in a proportion of about 200 mg, preferably about 5.0 to 150 mg.

The thickness of the acid-resistant film 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 cohesive force of the film and the adhesion to the aluminum alloy foil and the heat-sealed resin layer. , 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 dispersion type 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, a dipping method, or the like, and then the temperature of the barrier layer is 70. It is carried out by heating to about 200 ° C. Further, before the chemical conversion treatment is applied to the barrier layer, the barrier layer may be subjected to a degreasing treatment by an alkaline 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 barrier layer.

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

The resin component used in the heat-fusing resin layer 4 is not particularly limited as long as it can be heat-fused, and examples thereof include polyolefins, cyclic polyolefins, carboxylic acid-modified polyolefins, and carboxylic acid-modified cyclic polyolefins. Be done. That is, the heat-bondable resin layer 4 may contain a polyolefin skeleton, and preferably contains a polyolefin skeleton. The fact that the heat-bondable 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 the maleic anhydride-modified polyolefin is measured by infrared spectroscopy, peaks derived from maleic anhydride are detected near a wave number of 1760 cm-1 and a wave number of 1780 cm-1. However, if the degree of acid denaturation is low, the peak may become small and may not be detected. In that case, it can be analyzed by nuclear magnetic resonance spectroscopy.

Specific examples of the polyolefin include polyethylene such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene; homopolypropylene, a block copolymer of polypropylene (for example, a block copolymer of propylene and ethylene), and polypropylene. Polypropylene such as a random copolymer of polyethylene (eg, a random copolymer of propylene and ethylene); a polyethylene-butene-propylene tarpolymer; etc. 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, butadiene, and isoprene. Be done. Examples of the cyclic monomer which is a constituent monomer of the cyclic polyolefin include cyclic alkenes such as norbornene; specifically, cyclic diene such as cyclopentadiene, dicyclopentadiene, cyclohexadiene, norbornadiene and the like. Styrene is also mentioned as a constituent monomer. Among these polyolefins, cyclic alkene is preferable, and norbornene is more preferable.

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

The carboxylic acid-modified cyclic polyolefin means that a part of the monomer constituting the cyclic polyolefin is copolymerized in place of α, β-unsaturated carboxylic acid or its anhydride, or α, β with respect to the cyclic polyolefin. -A polymer obtained by block polymerization or graft polymerization of unsaturated carboxylic acid or its anhydride. The same applies to the cyclic polyolefin that is modified with carboxylic acid. The carboxylic acid used for the modification is the same as that used for the modification of the carboxylic acid-modified polyolefin.

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

The heat-bondable resin layer 4 may be formed of one type of resin component alone, or may be formed of a blended polymer in which two or more types of resin components are combined. Further, the heat-sealing resin layer 4 may be formed of only one layer, or may be formed of two or more layers with the same or different resin components.

The thickness of the heat-sealing resin layer 4 can be appropriately selected, and may be about 10 to 100 μm, preferably about 15 to 50 μm.

Further, the heat-sealing resin layer 4 may contain a lubricant or the like, if necessary. When the heat-bondable resin layer 4 contains a lubricant, the moldability of the packaging material can be improved. The lubricant is not particularly limited, and a known lubricant can be used, and examples thereof include those exemplified in the above-mentioned base material layer 1. The lubricant may be used alone or in combination of two or more. The content of the lubricant in the heat-sealing resin layer 4 is not particularly limited, and is preferably about 0.01 to 0.20% by mass from the viewpoint of improving the moldability and the insulating property of the electronic packaging material. The amount is preferably about 0.05 to 0.15% by mass.

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

The adhesive layer 5 is formed of a resin capable of adhering the barrier layer 3 and the heat-sealing resin layer 4. As the resin used for forming the adhesive layer 5, the same adhesive as the adhesive exemplified in the adhesive layer 2 can be used in terms of the adhesive mechanism, the type of adhesive component, and the like. Further, as the resin used for forming the adhesive layer 5, polyolefin-based resins such as the polyolefins exemplified in the above-mentioned heat-sealing resin layer 4, cyclic polyolefins, carboxylic acid-modified polyolefins, and carboxylic acid-modified cyclic polyolefins can also be used. .. From the viewpoint of excellent adhesion between the barrier layer 3 and the heat-bondable resin layer 4, the polyolefin is preferably a carboxylic acid-modified polyolefin, and particularly preferably a carboxylic acid-modified polypropylene. That is, the adhesive layer 5 may contain a polyolefin skeleton, and preferably contains a polyolefin skeleton. The fact that 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 the maleic anhydride-modified polyolefin is measured by infrared spectroscopy, peaks derived from maleic anhydride are detected near a wave number of 1760 cm-1 and a wave number of 1780 cm-1. However, if the degree of acid denaturation is low, the peak may become small and may not be detected. In that case, it can be analyzed by nuclear magnetic resonance spectroscopy.

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

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

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

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

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

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

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

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. It is more preferably in the range of 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, but when the adhesive exemplified in the adhesive layer 2 is used, it is preferably about 2 to 10 μm, more preferably 2 to 2. About 5 μm can be mentioned. Further, when the resin exemplified in the heat-sealing resin layer 4 is used, it is preferably about 2 to 50 μm, more preferably about 10 to 40 μm. Further, in the case of a cured product of the acid-modified polyolefin and the curing agent, it is preferably about 30 μm or less, more preferably about 0.1 to 20 μm, and further 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 designability, electrolytic solution resistance, scratch resistance, moldability, etc., if necessary, on the base material layer 1 (with the barrier layer 3 of the base material layer 1). On the opposite side), a surface coating layer (not shown) may be provided, if necessary. The surface coating layer is a layer located on 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. Further, an additive may 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, and organic substances. The shape of the additive 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. As additives, specifically, talc, silica, graphite, kaolin, montmoriloid, montmorillonite, synthetic mica, hydrotalcite, silica gel, zeolite, aluminum hydroxide, magnesium hydroxide, zinc oxide, magnesium oxide, aluminum oxide, Neodium 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 Examples thereof include melting point nylon, crosslinked acrylic, crosslinked styrene, crosslinked polyethylene, benzoguanamine, gold, aluminum, copper and nickel. These additives may be used alone or in combination of two or more. Among these additives, silica, barium sulfate, and titanium oxide are preferable from the viewpoint of dispersion stability and cost. Further, the additive may be subjected to various surface treatments such as an insulation treatment and a high dispersibility treatment on the surface.

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, and more preferably about 0.1 to 0.5% by mass.

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 additive is blended, the additive 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 about 0.5 to 10 μm, preferably about 1 to 5 μm.

3. 3. The preparation method of the packaging material TECHNICAL FIELD The present invention relates to packaging material, as long as the laminate as a laminate of layers having a predetermined composition can be obtained, is not particularly limited. An example of the method for producing the packaging material of the present invention is as follows. First, a laminate in which the base material layer 1, the adhesive layer 2, and the barrier layer 3 are laminated in this order (hereinafter, may be referred to as “laminate A”) is formed. The formation of the laminated body A is specifically carried out by applying a gravure coating method to the barrier layer 3 on the base material layer 1 or, if necessary, the surface of which has been chemically converted, with the adhesive used for forming the adhesive layer 2. This can be performed by a dry laminating method in which the barrier layer 3 or the base material layer 1 is laminated and the adhesive layer 2 is cured after being applied and dried by a coating method such as a roll coating method.

Next, the heat-sealing resin layer 4 is laminated on the barrier layer 3 of the laminated body A. When the heat-sealing resin layer 4 is directly laminated on the barrier layer 3, the resin components constituting the heat-sealing resin layer 4 are coated on the barrier layer 3 of the laminated body A by a gravure coating method or a roll coating method. It may be applied by a method such as. When the adhesive layer 5 is provided between the barrier layer 3 and the heat-bondable resin layer 4, for example, (1) the adhesive layer 5 and the heat-bondable resin layer are placed on the barrier layer 3 of the laminated body A. A method of laminating 4 by co-extruding (co-extrusion laminating method), (2) Separately, a laminated body in which the adhesive layer 5 and the heat-sealing resin layer 4 are laminated is formed, and this is used as a barrier layer of the laminated body A. By a method of laminating on 3 by a thermal laminating method, (3) an adhesive for forming an adhesive layer 5 on the barrier layer 3 of the laminated body A by an extrusion method, a solution-coated method of drying at a high temperature, and a baking method. A method of laminating a heat-sealing resin layer 4 which has been laminated and previously formed into a sheet on the adhesive layer 5 by a thermal laminating method. A method (sandwich laminating method) in which the laminated body A and the heat-bondable resin layer 4 are bonded to each other via the adhesive layer 5 while pouring the melted adhesive layer 5 between the heat-bondable resin layer 4 and the heat-bonded resin layer 4. 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 barrier layer 3. The surface coating layer can be formed, for example, by applying the above resin for forming the surface coating layer to the surface of the base material layer 1. The order of the step of laminating the barrier layer 3 on the surface of the base material layer 1 and the step of laminating the surface coating layer on the surface of the base material layer 1 is not particularly limited. For example, after forming the surface coating layer on the surface of the base material layer 1, the barrier layer 3 may be formed on the surface of the base material layer 1 opposite to the surface coating layer.

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

In the packaging material of the present invention, each layer constituting the laminate is to improve or stabilize film forming property, laminating process, suitability for secondary processing (pouching, embossing) of the final product, etc., as necessary. , Corona treatment, blast treatment, oxidation treatment, ozone treatment and other surface activation treatments may be performed.

4. Uses of Packaging Material The packaging material of the present invention is used in a wide range of fields as a packaging material for accommodating foods, chemicals, battery elements, etc. (the packaging material is molded so as to accommodate the contents). When the package of the present invention is used to store contents such as foods, chemicals, and battery elements, the package is used so that the sealant portion of the package is on the inside (the surface in contact with the contents).

For example, when the packaging material of the present invention is used as a packaging material for a battery, a battery element having at least a positive electrode, a negative electrode, and an electrolyte is connected to each of the positive electrode and the negative electrode in a package formed of the packaging material of the present invention. With the metal terminals protruding outward, the peripheral edge of the battery element is covered so that a flange portion (region where the heat-sealing resin layers come into contact with each other) can be formed, and the heat-sealing resin of the flange portion is covered. By heat-sealing and sealing the layers, a battery in which a battery element is housed in a package is provided.

The battery packaging material 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 the secondary battery 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, a nickel / cadmium livestock battery, a nickel / iron livestock battery, and a nickel / zinc livestock battery. Examples thereof include batteries, silver oxide / zinc livestock batteries, metal air batteries, polyvalent cation batteries, capacitors, capacitors and the like. Among these secondary batteries, lithium ion batteries and lithium ion polymer batteries are examples of suitable application targets for battery packaging materials.

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.

Examples 1-5 and Comparative Examples 1-4
<Manufacturing of packaging materials>
A barrier layer made of aluminum foil (JIS H4160: 1994 A8021HO) having been subjected to chemical conversion treatment on both sides was laminated on the base material layer by a dry laminating method. Specifically, a two-component urethane adhesive (polyol compound and aromatic isocyanate compound) was applied to one surface of the barrier layer to form an adhesive layer (thickness 3 μm) on the barrier layer. Next, after laminating the adhesive layer and the base material layer on the barrier layer, an aging treatment was carried out to prepare a laminated body of the base material layer / adhesive layer / barrier layer. In the chemical conversion treatment of the aluminum foil used as the barrier layer, a treatment liquid consisting of a phenol resin, a chromium fluoride compound, and phosphoric acid was roll-coated so that ^{the coating amount of chromium was 10 mg / m 2 (dry mass).} This was done by applying and baking on both sides of the aluminum foil by the method.

Next, in Examples 1, 2 and 5 and Comparative Examples 1 and 2, the carboxylic acid-modified polypropylene (arranged on the barrier layer side) and the random polypropylene (innermost layer) are co-extruded onto the barrier layer of the laminated body. As a result, the adhesive layer / heat-sealing resin layer was laminated on the barrier layer. Next, the obtained laminate was heated to obtain a packaging material in which a base material layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-sealing resin layer were laminated in this order. In the base material layer used in Example 5, PET (thickness 12 μm) and nylon (thickness 15 μm) are bonded with a two-component urethane adhesive (thickness 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-based curing agent was applied onto the barrier layer of the laminate and dried. Further, an unstretched polypropylene film (innermost layer) was laminated on it. The content of the curing agent was 5% by mass with respect to the total solid content mass after drying. Next, the obtained laminate was aged to obtain a packaging material in which a base material layer, an adhesive layer, a barrier layer, an adhesive layer, and a heat-sealing 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) / Carboxylic acid-modified polypropylene and cured product of curing agent (2 μm) / Unstretched polypropylene (25 μm)
Example 4: Nylon (25 μm) / Adhesive layer (3 μm) / Aluminum foil (35 μm) / Carboxylic acid-modified polypropylene and cured product of 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) / carboxylic acid-modified polypropylene and cured product of curing agent (2 μm) / unstretched polypropylene (25 μm)
Comparative Example 4: Nylon (15 μm) / Adhesive layer (3 μm) / Aluminum foil (35 μm) / Carboxylic acid-modified polypropylene and cured product of curing agent (2 μm) / Unstretched polypropylene (30 μm)

<Breaking energy of laminated body>
For each of the packaging materials obtained above, the breaking energy per 1 m of unit width in MD and TD was measured when the MD and TD of each packaging material were subjected to a tensile test under the following test conditions, respectively. Obtain the data of "Test force-Displacement amount curve", save the data in csv file format, and use spreadsheet software (Microsoft Excel®) until the laminate breaks. It was calculated by integrating the data. At this time, it was calculated by converting it into breaking energy per 1 m width of each packaging material (dividing by 0.015) by the spreadsheet software. Then, the breaking energy per 1 m of unit width in MD and the breaking energy per 1 m of unit width in TD were totaled. Five packaging materials to be measured were prepared for each, and the average of three values excluding the maximum value and the minimum value among the breaking energy values for the five samples was taken as the breaking energy of the laminated body. The results are shown in Table 1.
(Test condition)
・ Test speed 50 mm / min
・ Width of test piece: 15 mm
-Test piece length: 100 mm
・ Distance between gauge points: 30 mm

For reference, the curve of the test force-displacement amount obtained in the tensile test (MD) of the packaging material of Comparative Example 2 is shown in FIG. The portion where the data of the curve of test force-displacement amount is integrated is the integrated value from the start of the tensile test (displacement amount 0) to the breaking point P of the laminated body, as shown in the schematic diagram of FIG. 5, for example. It corresponds to the area of the shaded area in FIG.

<Puncture strength of laminated body>
For each of the packaging materials obtained above, the piercing strength was measured from the base material layer side by a method in accordance with JIS Z1707: 1995. As the piercing strength measuring device, ZP-50N (force gauge) and MX2-500N (measuring stand) manufactured by Imada Co., Ltd. were used. The results are shown in Table 1.

<Total penetration energy of the laminated body>
For each of the packaging materials obtained above, the total penetration energy was measured from the base material layer side by a method in accordance with JIS K7124-2: 1999. As a measuring device, a drop weight type graphic impact tester (manufactured by Toyo Seiki Co., Ltd.) was used. The measurement conditions were a hammer weight of 6.4 kg, a drop height of 300 mm, a sample clamp diameter of 40 mmφ, a hammer diameter of 12.7 mmφ, and a hammer shape of a hemispherical shape. The results are shown in Table 1.

<Puncture strength of each layer>
A base material layer, a barrier layer, and a laminate of an adhesive layer and a heat-sealing resin layer used in the production of the above-mentioned packaging material are prepared, and the base material is prepared by a method in accordance with JIS Z1707: 1995, respectively. The piercing strength was measured from the layer side. As the piercing strength measuring device, ZP-50N (force gauge) and MX2-500N (measuring stand) manufactured by Imada Co., Ltd. were used. The results are shown in Table 1.

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

Next, the molded product was placed on a rigid and flat surface, and a round bar having a diameter of 16 mm was placed in the center of the molded product so as to cross the molded product. Next, from a height of 610 mm, a heavy object weighing 9.1 kg was dropped onto the round bar. After the drop, the molded product without cutting was evaluated as having excellent impact resistance (A), and the cut product was evaluated as having poor impact resistance (C). The results are shown in Table 1.

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

1 Base material layer 2 Adhesive layer 3 Barrier layer 4 Heat-sealing resin layer 5 Adhesive layer

Claims (8)

It is composed of a laminate having at least a base material layer, a barrier layer, and a heat-sealing resin layer in this order.
In the laminated body, the breaking energy per 1 m of unit width calculated from the curve of test force-displacement amount measured when the tensile test is performed under the following test conditions is perpendicular to the thickness direction of the laminated body. A packaging material having a total of 400 J or more in one direction and the other directions perpendicular to the one direction and the thickness direction of the laminate.
(Test condition)
Test speed: 50 mm / min
Width of test piece: 15 mm
Specimen length: 100 mm
Distance between gauge points: 30 mm The packaging material according to claim 1, wherein one direction is the MD of the laminated body and the other direction is the TD of the laminated body. The packaging material according to claim 1 or 2, wherein the laminated body has a piercing strength of 23 N or more measured from the base material layer side by a method according to JIS Z1707: 1995. The laminated body conforms to the provisions of JIS K7124-2: 1999, and the total penetration energy measured from the base material layer side is 1.4 J or more under the following measurement conditions, claim 1 to 3. The packaging material described in either.
(Measurement condition)
Hammer weight: 6.4 kg
Drop height: 300 mm
Sample clamp diameter: 40 mmφ
Hammer diameter: 12.7 mm
Hammer shape: hemispherical The packaging material according to any one of claims 1 to 4, wherein the base material layer has a thickness of 20 μm or more. The packaging material according to any one of claims 1 to 5, wherein the barrier layer is made of aluminum foil. The packaging material according to any one of claims 1 to 6, which is used for accommodating a battery element. 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 packaging material according to any one of claims 1 to 7.

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