KR102668250B1 - Packaging material for batteries, battery bag, and battery - Google Patents

Abstract

The object of the present invention is to provide a battery packaging material with excellent heat-resistant adhesive strength and heat-sealing resistance before and after deformation, even at an aging temperature of less than 60°C. It is a battery packaging material made by sequentially stacking an outer resin film layer (11), an outer adhesive layer (12), a metal foil layer (13), an inner adhesive layer (14), and a heat sealing layer (15). The outer layer side adhesive layer 12 is formed of a polyurethane adhesive containing a specific number average molecular weight polyester polyol (A) and a specific amount of a specific species of polyisocyanate component (B). The polyester polyol (A) is composed of a polyacid component including an aromatic polyacid component accounting for a specific amount out of 100 mol% of the polyacid component, and a polyhydric alcohol component.

Description

Battery packaging materials, battery containers, and batteries {PACKAGING MATERIAL FOR BATTERIES, BATTERY BAG, AND BATTERY}

The present invention relates to a polyurethane adhesive for battery packaging for forming battery containers or battery packs for secondary batteries such as lithium ion batteries. In addition, the present invention relates to a battery packaging material in which the outer resin film layer 11 and the metal foil layer 13 are laminated by bonding these layers using a polyurethane adhesive. In addition, the present invention relates to a battery container obtained by determining the direction of the battery packaging material so that the outer layer side resin film layer 11 is located in the outer layer, and then molding the battery packaging material, and a battery manufactured using the battery container. .

With the rapid development in the field of electronic devices such as mobile phones and mobile computers, demand for secondary batteries such as lightweight and small lithium ion batteries has increased. As an exterior body of a secondary battery, a metal container has previously been used. However, from the viewpoint of weight reduction and productivity, packaging materials formed by laminating plastic films and metal foils are becoming the mainstream exterior body of secondary batteries.

The simplest packaging material is a laminate as shown in Figure 1. The laminate shown in Figure 1 is sequentially composed of the outer layer side resin film layer 11, the outer layer side adhesive layer 12, the metal foil layer 13, the inner layer side adhesive layer 14, and the heat seal layer 15, in order from the outer layer side. It comes true.

An example of a battery container is one in which a packaging material composed of the above laminate is molded (deep drawing molding processing, overhanging molding processing, etc.) as shown in FIG. 2. The packaging material is oriented and then molded so that the outer resin film layer 11 constitutes the convex side surface of the battery container and the heat seal layer 15 constitutes the concave side surface of the battery container. Then, batteries are made by enclosing electrodes and electrolyte on the concave side of the battery container.

Patent Document 1 discloses a packaging material for batteries (Patent Document 1: Japanese Patent No. 5382256). In this battery packaging material, these layers are bonded by providing an adhesive layer with a specific molecular weight, polyester composition, and tensile stress between the outer resin film layer and the metal foil layer. These battery packaging materials have excellent formability and durability.

Another document discloses a method for manufacturing battery packaging materials (Patent Document 2: Japanese Patent Application Laid-open 2005-32456). In this method, after attaching the outer layer resin film and aluminum foil, first-stage aging is performed at a temperature range of 50 to 85 ° C. In addition, after attaching the inner layer resin film mixed with lubricant and the aluminum foil, a second stage aging is performed at a temperature range of 30 to 50 ° C. With this method, it is possible to manufacture packaging materials for molding with excellent moldability by suppressing the decrease in lubricity due to aging.

Another document discloses packaging materials for molding (Patent Document 3: Japanese Patent Publication 2015-166261). In this packaging material for molding, an adhesive layer containing a colored pigment is provided between the heat-resistant resin layer and the metal foil layer. Additionally, the adhesive layer is composed of a composition containing a polyester resin of a specific molecular weight and dispersion degree, and 50 mol% or more of aromatic polyisocyanate. These packaging materials for molding have excellent moldability and heat resistance to heat sealing.

Another document discloses battery packaging materials (Patent Document 4: Japanese Patent Publication 2014-186983). This battery packaging material is composed of a laminate having a base material layer, an adhesive layer, and a barrier sealant layer. Additionally, the adhesive layer is made of a composition containing a thermosetting resin, a curing accelerator, and an elastomer resin. In these battery packaging materials, heat wrinkling defects do not occur and curing is completed in a short time. Additionally, these battery packaging materials have excellent adhesion and moldability.

Another document shows an exterior material for a power storage device (Patent Document 5: Japanese Patent Laid-Open No. 2013-157285). This electrical storage device exterior material is composed of a laminate having a base material layer, a first adhesive layer, a metal foil layer, a corrosion prevention treatment layer, a second adhesive layer, and a sealant layer. In addition, the first adhesive layer is formed of at least one compound of polyester polyol and acrylic polyol having a hydroxyl group in the side chain and an aliphatic isocyanate curing agent. The exterior material of such a power storage device has excellent electrostatic resistance.

Japanese Patent Registration No. 5382256 Japanese Patent Publication No. 2005-32456 Japanese Patent Publication No. 2015-166261 Japanese Patent Publication No. 2014-186983 Japanese Patent Publication No. 2013-157285

Recently, as the use of secondary batteries has expanded in fields such as automobiles and home power storage, there has been a demand for increased capacity of secondary batteries. For this reason, there is a demand for excellent moldability of battery packaging materials.

In addition, in order to provide excellent moldability to battery packaging materials, it is important to properly lubricate the packaging material and mold being formed. At the same time, it is important to prevent pinholes from forming in the metal foil at square corners with high elongation. Therefore, there are cases where a lubricant is mixed in advance into the composition that constitutes the resin film layer and sealant layer on the outer layer of the packaging material.

In addition, the adhesive for attaching the outer resin film layer and the metal foil is a curable polyurethane adhesive in terms of moldability and heat resistance. In order for a laminate obtained using a curable polyurethane adhesive to have excellent performance, aging at a temperature of 60°C or higher for about a week is required. However, in a temperature environment of 60°C or higher, the lubricant previously mixed into the film layer and heat seal layer ends up infiltrating into the inside. Because of this, each layer loses its original activity. In addition, it is possible to coat the laminate with a lubricant after aging, but this reduces the productivity of the battery packaging material and thus harms economic feasibility.

Additionally, when manufacturing a battery container and filling the battery container with an electrolyte solution, the molded battery packaging material may deform. Specifically, the centers of the four angled surfaces of the convex side surface of the battery container are recessed, and dimple-shaped wrinkles are formed at each corner of the convex side. Due to this deformation, the heat seal layer 15 is likely to lift off from other layers in the vicinity of the convex side corner.

This invention was made in consideration of the above background, and provides a battery packaging material made of a laminate. Since the activity of the lubricant is maintained, the battery packaging material has moldability even when the laminate obtained using an adhesive is aged at 40°C. At the same time, the goal is to ensure that the adhesion between the layers of the laminate that constitutes the battery packaging material is not damaged even at high temperatures. In addition, in providing a battery packaging material, the problem is that even if the molded product comprised of the battery packaging material is deformed, the layers in the laminate constituting the battery packaging material do not come off. Another task is to provide a battery equipped with a battery container composed of such battery packaging material.

The inventors of the present invention discovered that the above problem could be solved by using the following outer layer side adhesive.

The present invention relates to a battery packaging material in which an outer resin film layer (11), an outer adhesive layer (12), a metal foil layer (13), an inner adhesive layer (14), and a heat seal layer (15) are sequentially laminated,

It relates to a battery packaging material in which the outer adhesive layer 12 is formed of a polyurethane adhesive containing a main agent containing a polyol component (A) and a curing agent containing a polyisocyanate component (B).

In the polyurethane adhesive used to form the battery packaging material of the present invention, the polyol component (A) is a mixture of a polyacid component and a polyhydric alcohol component, with the aromatic polyacid component accounting for 45 to 95 mol% out of 100 mol% of the polyacid component. It is a reaction product and is a polyester polyol with a number average molecular weight of 10,000 to 40,000, or

or the polyol component (A) is a mixture of the reaction product (1) of the polyacid component (1) and the polyhydric alcohol component (1) and the reaction product (2) of the polyacid component (2) and the polyhydric alcohol component (2). In addition, of the total 100 mol% of the polyacid component (1) and the polyacid component (2), the aromatic polyacid component accounts for 45 to 95 mol%, and the number average molecular weight of the mixture is 10,000 to 40,000. phosphorus, polyester polyol,

The polyisocyanate component (B) is produced by adding a trifunctional alcohol to diphenylmethane diisocyanate (hereinafter sometimes abbreviated as MDI), and forms a mixture of an adduct and hexamethylene diisocyanate (hereinafter abbreviated as HDI). It contains a functional derivative and is characterized in that isocyanate groups derived from diphenylmethane diisocyanate account for 40 to 90 mol% of 100 mol% of isocyanate groups in the polyisocyanate component (B).

In addition, this invention relates to a battery container formed by molding the above-mentioned battery packaging material, wherein the outer resin film layer 11 constitutes a convex surface and the heat sealing layer 15 constitutes a concave surface.

Additionally, the present invention relates to a battery made using the above battery container.

The present invention is a battery packaging material made by sequentially stacking an outer resin film layer (11), an outer adhesive layer (12), a metal foil layer (13), an inner adhesive layer (14), and a heat sealing layer (15). The outer layer side adhesive layer 12 is a polyester polyol having a specific number average molecular weight, and is composed of an adhesive containing a polyester polyol in which the aromatic polyacid component among the polyacid components accounts for a specific mole % and a specific polyisocyanate component. Due to this configuration, even when aging is performed on a laminate obtained using an adhesive at less than 60°C, the battery packaging material has excellent moldability, and the interlayer adhesion of the laminate constituting the battery packaging material is unlikely to be damaged even at high temperatures. . For this reason, a battery packaging material is provided in which the layers in the laminate constituting the battery packaging material do not come off even if the molded product comprised of the battery packaging material is deformed. A battery with excellent reliability is provided by a battery container comprised of the battery packaging material.

1 is a schematic cross-sectional view of the battery packaging material of the present invention.
Figure 2 is a schematic perspective view of a tray-shaped container related to one aspect of the battery container of the present invention.

Hereinafter, embodiments of the present invention will be described in detail. In this specification, description of “arbitrary value A to arbitrary value B”, that is, description of the range “A to B” expressed using “~” refers to value A; Range greater than number A and less than number B; and the numerical value B.

The polyurethane adhesive of the present invention is used to form battery packaging materials used in the production of battery containers. The shape of the battery container includes a tray shape as shown in FIG. 2, as well as a cylinder shape (cylinder, square cylinder, elliptical cylinder, etc.). These battery containers are obtained by molding and processing sheet-shaped battery packaging materials. The inside of the battery container, that is, the surface in contact with the electrolyte, is the heat sealing layer 15. The heat seal layer 15 constituting the flange portion of the battery container and the heat seal layer 15 constituting another battery packaging material are brought into contact so as to face each other and the contact portion is heated to fuse the heat seal layers 15. You can do it. This allows the electrolyte to be encapsulated. Here, the heat sealing layer 15 constituting another battery packaging material may be the heat sealing layer 15 constituting the flange portion of another battery container.

The battery container is provided with a metal foil layer (13). In the battery container of this embodiment, the side close to the electrolyte bordering the metal foil layer 13 is referred to as the “inside”. Additionally, the other layers located on the inside are collectively referred to as “inner layer.” In addition, the side farthest from the electrolyte, bordering on the metal foil layer 13, is called the “outside.” Additionally, the other layers located on the outside are collectively referred to as “outer layer.” The battery packaging material of this embodiment is used to form a battery container. Therefore, even in the battery packaging material of this embodiment, the side facing closer to the electrolyte, bordering on the metal foil layer 13, is called the “inside”. Additionally, the other layers located on the inside are collectively referred to as “inner layer.” In addition, the side facing away from the electrolyte, bordering on the metal foil layer 13, is called the “outside.” Additionally, the other layers located on the outside are collectively referred to as “outer layer.”

In addition, the polyurethane adhesive described in this embodiment is a composition for forming a laminated structure by attaching the outer layer side resin film layer 11 and the metal foil layer 13.

The polyurethane adhesive according to the present embodiment functions as an adhesive by using a base material and a curing agent simultaneously. It may be a so-called two-liquid mixing type adhesive in which the base material and the curing agent are mixed at the time of use. In addition, the polyurethane adhesive according to the present embodiment may be a one-component type adhesive in which the base material and the curing agent are mixed in advance. Additionally, a type in which a plurality of base materials and/or a plurality of curing agents are mixed at the time of use may be used.

The polyol component (A) included in the main subject includes polyols with relatively high molecular weight such as polyester polyol, polyether polyol, polycarbonate polyol, polyolefin polyol, and acrylic polyol, and polyols with relatively small molecular weight such as ethylene glycol and trimethylolpropane. can be mentioned. In addition, polyurethane polyol obtained by reacting polyol with an isocyanate component under conditions with excess hydroxyl groups can also be included as one of the polyol components (A). These can be used individually or two or more types can be used together as long as they do not adversely affect adhesive strength or moldability.

Examples of polyester polyol include polyester polyol obtained by reacting a polyacid component and a polyhydric alcohol component.

Examples of polyacid components include isophthalic acid, terephthalic acid, naphthalene dicarboxylic acid, phthalic anhydride, adipic acid, azelaic acid, sebacic acid, succinic acid, glutaric acid, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, and maleic anhydride. , itaconic acid anhydride, and its ester compounds. These can be used individually or two or more types can be used in combination.

Examples of polyhydric alcohol components include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1,6-hexanediol, neopentyl glycol, 1,4-butylene glycol, and 1,4- Cyclohexanedimethanol, trimethylolpropane, glycerin, 1,9-nonanediol, 3-methyl-1,5-pentanediol, polyether polyol, polycarbonate polyol, polyolefin polyol, acrylic polyol, polyurethane polyol, etc. there is. These can be used individually or two or more types can be used in combination.

Also, a type of polyester polyol obtained by further reacting the polyester polyol with polyhydric acids such as phthalic acid, trimellitic acid, and pyromellitic acid and their anhydrides is also included. These polyester polyols have a carboxyl group at one part of the molecule, for example, inside the molecule or at the end of the molecule.

In addition, the above polyester polyols include, for example, 2,4-trylene diisocyanate, 2,6-trylene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, and 1,5-naphthalene diisocyanate. Polyester urethane polyols that can be obtained by reacting with polyisocyanates, such as hexamethylene diisocyanate and hydrogenated diphenylmethane diisocyanate, can also be considered a type of polyester polyol.

The number average molecular weight of polyester polyol is 10,000 to 40,000, preferably 15,000 to 30,000.

In addition, among 100 mol% of the polyacid component as a constituent, the proportion of the aromatic polyacid component (hereinafter sometimes referred to as content rate) is 45 to 95 mol%, and is preferably 55 to 85 mol%.

The fact that the number average molecular weight of the polyester polyol is 10000 or more and that the aromatic polyacid component is 45 mol% or more improves the property that the adhesion between layers is not damaged even at high temperatures (hereinafter sometimes referred to as heat-resistant adhesiveness). It helps to do it.

On the other hand, when the number average molecular weight is 40000 or less, the solubility of the polyester polyol in the diluted solution is improved. For this reason, it is easy to control the viscosity of the adhesive during coating, making it easy to apply the adhesive. In addition, from the viewpoint of improving the adhesive strength between the outer resin film layer 11 and the metal foil layer 13, it is preferable that the polyacid component is 95 mol% or less.

In other words, by using this polyester polyol, the adhesive strength (hereinafter sometimes referred to as heat-resistant adhesive strength) under high temperature between the outer layer side resin film layer 11 and the metal foil layer 13 is increased, and at the same time, it is composed of a battery packaging material. When a molded product (hereinafter sometimes referred to as molded product) is heat-sealed, the heat resistance to heat sealing (hereinafter sometimes referred to as heat-sealing resistance) becomes better.

In the present invention, a mixture of various polyester polyols may be used as the polyol component (A). In this embodiment, the reaction product (1) of the polyacid component (1) and the polyhydric alcohol component (1) and the reaction product (2) of the polyacid component (2) and the polyhydric alcohol component (2) are prepared, respectively. When mixing the reaction product (1) and the reaction product (2), the aromatic polyacid component accounts for 45 to 95 mol% of the total 100 mol% of the polyacid component (1) and the polyacid component (2). Specifically, the mixture of polyester polyols is selected so that the average molecular weight of the mixture is 10,000 to 40,000.

For example, with respect to the reaction product (1) of the polyhydric acid component (1) containing only the aromatic polyacid component and the polyhydric alcohol component (1), the polyhydric acid component (2) containing a small content of the aromatic polyhydric acid component and the polyhydric alcohol component ( A mixture may be obtained by mixing the reaction product (2) of 2). As a result of mixing, the aromatic polyacid component should only occupy 45 to 95 mol% of the total 100 mol% of the polyacid component (1) and the polyacid component (2).

Likewise, as a result of mixing reaction products (1) and (2) with different number average molecular weights, the number average molecular weight of the mixture may be 10,000 to 40,000.

The number average molecular weight of polyester polyol is a value converted to polystyrene by gel permeation chromatography (GPC). The number average molecular weight is, for example, apparatus for high-performance liquid chromatography: Showex (model name, Showa Electric Co., Ltd. product), column: KF-805L, KF-803L, and KF-802 (Showa Electric Co., Ltd. product) ), the temperature of the column is set to 40°C, THF is used as an eluent, the flow rate is set to 0.2 ml/min, detection is set to RI, the sample concentration is set to 0.02%, and polystyrene is used as a standard sample. So, the values obtained through GPC can be used. The number average molecular weight of the present invention describes the value measured by the above method.

The polyisocyanate component (B) contained in the curing agent includes an adduct obtained by adding a trifunctional alcohol to diphenylmethane diisocyanate and a polyfunctional derivative of hexamethylene diisocyanate.

Examples of the trifunctional alcohol include glycerol, trimethylolpropane (hereinafter sometimes abbreviated as TMP), trimethylolethane, trimethylolbutane, and 1,2,6-hexane triol.

The multifunctional derivatives include dimer, nurate, biuret, allophanate, polyisocyanate having a 2,4,6-oxadiazinetrione ring obtained from carbon dioxide and the polyisocyanate monomer, and the trifunctional An adduct product obtained by adding alcohol to hexamethylene diisocyanate can be mentioned. .

Among the polyisocyanate components (B), a mixture of an adduct form obtained by adding trimethylolpropane to diphenylmethane diisocyanate and a nurate form of hexamethylene diisocyanate is preferable. This mixture is more preferable as the polyisocyanate component (B) from the viewpoint of curability at low temperature and heat sealing resistance of the molded product after the molding consisting of the battery packaging material is deformed (hereinafter sometimes referred to as the molded product after deformation).

Additionally, the polyisocyanate component (B) contains 40 to 90 mol% of isocyanate groups derived from diphenylmethane diisocyanate based on 100 mol% of isocyanate groups, and is preferably 60 to 80 mol%. When the isocyanate group accounts for 40 mol% or more, the heat-resistant adhesive strength and heat-sealing resistance of the molded product are improved. In addition, when the specific gravity of the isocyanate group is 90 mol% or less, the heat-sealing resistance of the molded product after deformation is improved.

The polyurethane adhesive of the present invention preferably has an isocyanate group equivalence ratio [NCO]/([OH]+[COOH]) of 10 to 30, and more preferably 15 to 30. Here, ([OH]+[COOH]) represents the equivalent weight of the total of the hydroxyl group and carboxyl group possessed by the polyol component (A) contained in the main substance. [NCO] represents the equivalent weight of the isocyanate group contained in the curing agent. That is, the heat-sealing resistance of the molded product after deformation tends to improve when the isocyanate group is 10 mol or more relative to the total of 1 mol of hydroxyl group and carboxyl group. In addition, since the isocyanate group is 30 mol or less per mole of the total, curing progresses quickly and the heat-resistant adhesion between the outer resin film layer 11 and the metal foil layer 13 is improved.

In addition to the polyurethane adhesive of the present invention, additives known to be used by adding to adhesives may be contained in the base material or curing agent.

For example, reaction accelerators can be used as additives.

Examples of the reaction accelerator include metal catalysts such as dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate, and dibutyltin dimaleate; 1,8-diaza-bicyclo(5,4,0)undecene-7, 1,5-diazabicyclo(4,3,0)nonene-5, 6-dibutylamino-1,8-dia Tertiary amines such as zabicyclo(5,4,0)undecen-7; Reactive tertiary amines such as triethanolamine are mentioned. One or two or more reaction accelerators selected from these groups can be used as additives.

From the viewpoint of improving the adhesive strength to metallic materials such as metal foil, a silane coupling agent can be used. Silane coupling agents include, for example, trialkoxy silanes having a vinyl group such as vinyltrimethoxy silane and vinyltriethoxy silane, 3-aminopropyltriethoxy silane, and N-(2-amino ethyl)3-aminopropyl. Trialkoxy silanes having an amine group such as trimethoxy silane; Examples of trialkoxy silanes having a glycidyl group include 3-glycidoxypropyltrimethoxy silane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxy silane, and 3-glycidoxypropyltriethoxy silane. These can be used individually or in any combination of two or more types.

The amount of the silane coupling agent added is preferably 0.1 to 5 parts by mass, more preferably 0.5 to 3 parts by mass, based on 100 parts by mass of the solid content of the polyol component (A). By adding a silane coupling agent in the above range, the adhesive strength to the metal foil is improved.

Likewise, from the viewpoint of improving the adhesive strength of the resin film to a metal-based material such as metal foil, phosphoric acid or a phosphoric acid derivative can be used as an additive. Phosphoric acid should have at least one free oxygen acid. For example, phosphoric acids such as hypophosphorous acid, phosphorous acid, orthophosphoric acid, hypophosphoric acid, and condensed phosphoric acids such as metaphosphoric acid, pyrophosphoric acid, tripolyphosphoric acid, polyphosphoric acid, and ultraphosphoric acid. You can hear it. Also, derivatives of phosphoric acid include compounds obtained by partially esterifying the above-mentioned phosphoric acid with alcohols while leaving at least one free oxyacid. Examples of alcohols include aliphatic alcohols such as methanol, ethanol, ethylene glycol, and glycerin, and aromatic alcohols such as phenol, xylenol, hydroquinone, catechol, and phloroglucinol. Phosphoric acid or its derivatives may be used in combination of two or more types. The amount of phosphoric acid or its derivative added is preferably 0.01 to 10% by mass, more preferably 0.05 to 5% by mass, and especially 0.05 to 1% by mass, based on the mass of the cured adhesive or the mass of the solid content of the adhesive. desirable.

Substances known as leveling agents or extinguishing agents may also be incorporated into the base for the purpose of improving the appearance of the laminate. Leveling agents include, for example, polyether-modified polydimethylsiloxane, polyester-modified polydimethylsiloxane, aralkyl-modified polymethylalkylsiloxane, polyester-modified hydroxyl group-containing polydimethylsiloxane, polyetherester-modified hydroxyl group-containing polydimethylsiloxane, and acrylic copolymerization. Examples include water, methacrylic copolymers, polyether-modified polymethylalkylsiloxane, acrylic acid alkyl ester copolymers, methacrylic acid alkyl ester copolymers, and lecithin.

Antifoaming agents include silicone resins, silicone solutions, copolymers of alkyl vinyl ether, alkyl acrylic ester, and alkyl methacrylic acid, and other known antifoaming agents.

The battery packaging material of the present invention can be manufactured by, for example, a commonly used method.

For example, the outer layer side resin film layer 11 and the metal foil layer 13 are formed using an adhesive containing the above-described polyol component (A) and polyisocyanate component (B) (hereinafter sometimes referred to as the outer layer side adhesive). By lamination, a partial laminated body (hereinafter sometimes referred to as an intermediate laminated body) is obtained. Next, the heat seal layer 15 can be laminated on the metal foil layer 13 side of the intermediate laminate using an arbitrarily selected inner layer side adhesive.

Alternatively, an intermediate laminate may be obtained by first laminating the metal foil layer 13 and the heat-sealing layer 15 using an inner layer side adhesive. Next, the metal foil layer 13 of the middle laminate and the outer resin film layer 11 can be laminated using the outer layer side adhesive. When obtaining the former outer layer intermediate laminate first, either the outer layer side resin film layer 11 or the metal foil layer 13 is used as a base material. The outer layer side adhesive is applied to one side of the substrate, the solvent is volatilized, and then another material is superimposed on the adhesive layer under heat and pressure. The adhesive layer can then be cured by aging the intermediate laminate under warm conditions. The mass of the adhesive layer per unit area is preferably about 1 to 10 g/m ² .

Similarly, in the case where the intermediate laminate of the latter inner layer is obtained first, the outer layer adhesive can be applied to either the surface of the outer layer side resin film layer 11 or the metal foil layer 13 of the intermediate laminate.

When applying the outer layer side adhesive to the above-described substrate, in order to adjust the coating liquid to an appropriate viscosity, the solution may be included within a range that does not affect the substrate during the drying process.

As solvents, ketone compounds such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, ester compounds such as methyl acetate, ethyl acetate, butyl acetate, ethyl lactate, and methoxyethyl acetate, diethyl ether, and ethylene. Ether compounds such as glycol dimethyl ether, aromatic compounds such as toluene and xylene, aliphatic compounds such as pentane and hexane, halogenated hydrocarbon compounds such as methylene chloride, chlorobenzene, and chloroform, alcohols such as ethanol, isopropyl alcohol, and normal butanol, Water, etc. are mentioned. These solvents may be used individually or in combination of two or more types.

Additionally, when alcohol or water is used as a solvent, it is preferable to chemically block the isocyanate groups in the polyisocyanate component (B) with an appropriate blocking agent.

In the present invention, devices for coating the outer layer adhesive include a comma coater, dry laminator, roll knife coater, die coater, roll coater, bar coater, gravure roll coater, reverse roll coater, blade coater, gravure coater, micro gravure coater, etc. This is mentioned.

The outer resin film layer 11 constituting the battery exterior material of the present invention is not particularly limited, but is preferably a polyamide film or polyester film. This film is preferably a stretched film. Additionally, these films may be colored in advance with pigments such as carbon black and titanium oxide. Additionally, the surface of such a film may be coated in advance with a coating agent such as a damage prevention coating agent, ink, etc. Additionally, such a film may be produced in advance by laminating two or more layers of the film in advance. The thickness of the outer resin film layer 11 is not particularly limited, but is preferably 12 to 100 μm.

The metal foil layer 13 constituting the battery exterior material of the present invention is not particularly limited, but an aluminum foil layer is preferable. The thickness of the metal foil layer 13 is not particularly limited, but is preferably 20 to 80 μm. In addition, the surface of the metal foil is subjected to preservative treatment such as chromate phosphate treatment, chromate chromate treatment, chromium oxide treatment, zinc phosphate treatment, zirconium phosphate treatment, zirconium oxide treatment, titanium phosphate treatment, hydrofluoric acid treatment, cerium treatment, hydrotalcite treatment, and other known treatments. It is desirable to carry out at least one of the embalming treatments. By performing preservative treatment, corrosion deterioration of the metal foil surface caused by the battery electrolyte can be suppressed. Additionally, it is a coating-type preservative that combines an organic primer or preservative on the antiseptic surface with an organic polymer, and includes at least one of organic substances such as phenol resin, amide resin, acrylic resin, polyvinyl alcohol, coupling agent, and other known organic substances. It is desirable to process the metal by baking it at a high temperature of about 200°C. By applying a preservative and an organic material to the surface of the metal foil, the metal foil and the adhesive can be more firmly adhered and the lifting of the layer between the metal foil layer and the adhesive layer can be further suppressed.

The heat-sealing layer 15 constituting the battery exterior material of the present invention is not particularly limited, but is at least one type of thermoplastic resin selected from the group consisting of polyethylene, polypropylene, olefin-based copolymers, acid modifications thereof, and ionomers. It is preferably composed of an unstretched film made of. The thickness of the heat seal layer is not particularly limited, but is preferably 20 to 150 μm.

The adhesive forming the inner layer side adhesive layer 14 constituting the battery exterior material of the present invention is not particularly limited, and a known adhesive may be used. It is advisable to select the adhesive appropriately so that the adhesive strength between the metal foil layer 13 and the heat-sealing layer 15 does not decrease due to the adhesive being attacked by the electrolyte of the battery.

For example, an adhesive combining polyolefin resin and polyfunctional isocyanate or an adhesive combining polyol and polyfunctional isocyanate may be used. After applying this adhesive to the metal foil layer using a gravure coater or the like, the solvent is volatilized by drying. The heat seal layer 15 is superimposed on the obtained adhesive layer under heat and pressure. Next, the metal foil layer 13 and the heat-sealing layer 15 can be firmly attached to each other by aging the intermediate laminate under heating.

Alternatively, the adhesive layer may be formed by melt-extruding an adhesive containing acid-modified polypropylene onto the metal foil layer 13 using a T-die extruder. By overlapping the heat seal layer 15 on the surface of this adhesive layer, the metal foil layer 13 and the heat seal layer 15 can be bonded together.

When both the outer layer side adhesive layer 12 and the inner layer side adhesive layer 14 require aging, they can be aged at 40°C at the same time by using the outer layer side adhesive used in the present invention.

The battery container of the present invention can be obtained by molding the above battery exterior material. The direction is determined before molding so that the outer resin film layer 11 forms a convex surface and the heat seal layer 15 forms a concave surface.

[Example]

Next, the present invention will be described in more detail through examples and comparative examples. % in examples and comparisons all means mass %.

(Synthesis Example 1)

232.4 g of isophthalic acid, 42.7 g of ethylene glycol, 71.8 g of neopentyl glycol, and 108.6 g of 1,6-hexanediol were added, an esterification reaction was performed at 200-230°C for 6 hours, and a predetermined amount of water was distilled out. 87.6 g of adipic acid was added and esterification reaction was performed again for 6 hours. After discharging a predetermined amount of water, 0.13 g of tetraisobutyl titanate was added, the pressure was gradually reduced, a transesterification reaction was performed at 1.3 to 2.6 hPa, 230 to 250°C for 3 hours, and the aromatic polyacid component was 70 mol%, number average. A polyester polyol with a molecular weight of 19,000 was obtained.

This polyester polyol was adjusted to a non-volatile content of 50% with ethyl acetate to obtain a polyester polyol solution (1) with a hydroxyl value of 2.85 mgKOH/g and an acid value of 0.1 mgKOH/g.

In addition, the number average molecular weight is a measured value converted to standard polystyrene. The number average molecular weight was measured using Showex (manufactured by Showa Electric Co., Ltd.) and columns: KF-805L, KF-803L, and KF-802 (manufactured by Showa Electric Co., Ltd.). The column temperature was set to 40°C, THF was used as an eluent, the flow rate was set to 0.2 ml/min, detection was set to RI, sample concentration was set to 0.02%, and standard polystyrene was used as the standard sample.

Also, the acid value and hydroxyl value were obtained as follows.

<Measurement of acid value (AV)>

Accurately measure about 1 g of sample (polyester polyol solution) in a stoppered Erlenmeyer flask, add 100 ml of toluene/ethanol (volume ratio: toluene/ethanol = 2/1) mixture, and dissolve. Here, phenolphthalein bleach is added as an indicator and maintained for 30 seconds. Afterwards, titrate with 0.1N alcoholic potassium hydroxide solution until the solution turns light pink. The acid value was obtained by the following formula (unit: mgKOH/g).

Acid value (mgKOH/g)=(5.611×a×F)/S

However, S: sample collection amount (g)

a: Consumption amount of 0.1N alcoholic potassium hydroxide solution (ml)

F: Titer of 0.1N alcoholic potassium hydroxide solution

<Measurement of hydroxyl value (OHV)>

Accurately measure approximately 1 g of sample (polyester polyol solution) in a stoppered Erlenmeyer flask, add 100 ml of toluene/ethanol (volume ratio: toluene/ethanol = 2/1) mixture, and dissolve. Add exactly 5ml of acetylating agent (25g of acetic anhydride dissolved in pyridine to make the volume 100ml) again and mix for about 1 hour. Here, add phenolphthalein reagent as an indicator and keep it for 30 seconds. Afterwards, titrate with 0.1N alcoholic potassium hydroxide solution until the solution turns light pink. The hydroxyl value was obtained by the following formula (unit: mgKOH/g).

Hydroxyl value (mgKOH/g)=[{(b-a)×F×28.05}/S]+D

However, S: sample collection amount (g)

a: Consumption amount of 0.1N alcoholic potassium hydroxide solution (ml)

b: Consumption amount of 0.1N alcoholic potassium hydroxide solution in blank experiment (ml)

F: Titer of 0.1N alcoholic potassium hydroxide solution

D: acid value (mgKOH/g)

(Synthesis Example 2)

232.4g of isophthalic acid, 42.7g of ethylene glycol, 71.8g of neopentyl glycol, and 108.6g of 1,6-hexanediol were added, an esterification reaction was performed at 200-230°C for 6 hours, and a predetermined amount of water was distilled out. 87.6 g of finic acid was added and esterification reaction was performed for another 6 hours. After distilling a predetermined amount of water, 0.13 g of tetraisobutyl titanate was added, the pressure was gradually reduced, and transesterification was performed at 1.3 to 2.6 hPa and 230 to 250°C for 3 hours to obtain polyester polyol.

In order to react about 90% of the hydroxyl groups of the polyester polyol with pyromellitic anhydride, 7.7 g of pyromellitic anhydride was added to the entire amount of the polyester polyol and reacted at 180°C for about 2 hours. Using liquid chromatography, it was confirmed that no unreacted pyromellitic anhydride remained in the reaction apparatus, and a polyester polyol modified with pyromellitic anhydride with 70 mol% of aromatic polyacid component and a number average molecular weight of 20,000 was obtained.

The polyester polyol modified with pyromellitic anhydride was adjusted to 50% of non-volatile content with ethyl acetate to obtain a polyester polyol solution (2) with a hydroxyl value of 0.41 mgKOH/g and an acid value of 2.40 mgKOH/g.

(Synthesis Example 3)

232.4g of isophthalic acid, 42.7g of ethylene glycol, 71.8g of neopentyl glycol, and 108.6g of 1,6-hexanediol were added, an esterification reaction was performed at 200-230°C for 6 hours, and a predetermined amount of water was distilled out. 87.6 g of finic acid was added and the esterification reaction was performed for another 6 hours. After distilling a predetermined amount of water, 0.13 g of tetraisobutyl titanate was added, the pressure was gradually reduced, and transesterification was performed at 1.3 to 2.6 hPa and 230 to 250°C for 3 hours to obtain polyester polyol.

To 600 g of the polyester polyol solution obtained by adjusting this polyester polyol to a non-volatile content of 80% with ethyl acetate, 3.2 g of trilene diisocyanate was added and reacted at 80° C. for 8 hours to obtain an aromatic polyacid component of 70 mol%, number average. Polyester polyurethane polyol with a molecular weight of 20,000 was obtained.

Additionally, this polyurethane polyol was adjusted to 50% of non-volatile content with ethyl acetate to obtain a polyester polyol solution (3) with a hydroxyl value of 2.71 mgKOH/g and an acid value of 0.1 mgKOH/g.

(Synthesis Example 4)

149.4 g of isophthalic acid, 149.4 g of terephthalic acid, 71.3 g of ethylene glycol, and 119.6 g of neopentyl glycol were added, an esterification reaction was carried out at 200-220°C for 6 hours, a predetermined amount of water was distilled, and then 40.4 g of sebacic acid was added. The esterification reaction was performed for another 6 hours. After distilling a predetermined amount of water, 0.13 g of tetraisobutyl titanate was added, the pressure was gradually reduced, a transesterification reaction was performed at 1.3 to 2.6 hPa, 230 to 250°C for 6 hours, and the aromatic polyacid component was 90 mol%, number average. A polyester polyol with a molecular weight of 19,800 was obtained.

Additionally, this polyester polyol was adjusted to 50% of non-volatile content with ethyl acetate to obtain a polyester polyol solution (4) with a hydroxyl value of 2.73 mgKOH/g and an acid value of 0.1 mgKOH/g.

(Synthesis Example 5)

83.2g of isophthalic acid, 83.2g of terephthalic acid, and 142.6g of ethylene glycol were added, an esterification reaction was performed at 200-220°C for 8 hours, and a predetermined amount of water was distilled out. Then, 188g of azelaic acid was added, and the esterification reaction continued for another 4 hours. did. After discharging a predetermined amount of water, 0.13 g of tetraisobutyl titanate was added, the pressure was gradually reduced, and a transesterification reaction was performed at 1.3 to 2.7 hPa and 230 to 250°C for 3 hours to obtain an aromatic polyacid component of 50 mol%, number average. A polyester polyol with a molecular weight of 22,000 was obtained.

This polyester polyol was adjusted to 50% of non-volatile content with ethyl acetate to obtain a polyester polyol solution (5) with a hydroxyl value of 2.45 mgKOH/g and an acid value of 0.1 mgKOH/g.

(Synthesis Example 6)

166.0 g of isophthalic acid, 166.0 g of terephthalic acid, 85.6 g of ethylene glycol, and 95.6 g of neopentyl glycol were added, an esterification reaction was performed at 200-220°C for 6 hours, and a predetermined amount of water was distilled, followed by tetraisobutyl titanate 0.12 g. g was added, the pressure was gradually reduced, and transesterification was performed at 1.3 to 2.6 hPa and 230 to 250°C for 3 hours to obtain a polyester polyol with 100 mol% of aromatic polyacid component and a number average molecular weight of 15,000.

This polyester polyol was adjusted to a non-volatile content of 50% with ethyl acetate to obtain a polyester polyol solution (6) with a hydroxyl value of 3.64 mgKOH/g and an acid value of 0.1 mgKOH/g.

(Synthesis Example 7)

132.8g of isophthalic acid, 42.7g of ethylene glycol, 71.8g of neopentyl glycol, and 108.6g of 1,6-hexanediol were added, an esterification reaction was performed at 200-230°C for 6 hours, and a predetermined amount of water was distilled out. 175.2 g of pinic acid was added and esterification reaction was performed for another 6 hours. After distilling a predetermined amount of water, 0.13 g of tetraisobutyl titanate was added, the pressure was gradually reduced, and transesterification was performed at 1.3 to 2.6 hPa and 230 to 250°C for 6 hours to obtain an aromatic polyacid component of 40 mol% and a number average molecular weight. 30,000 polyester polyol was obtained.

This polyester polyol was adjusted to 50% non-volatile content with ethyl acetate to obtain a polyester polyol solution (7) with a hydroxyl value of 1.77 mgKOH/g and an acid value of 0.1 mgKOH/g.

[Manufacture of subject (1)]

After mixing 200 g of polyester polyol solution (1) (solid content 100 g) with 1 g of KBM-403 (silane coupling agent), 2 g of ethyl acetate was added to obtain base material (1) with 50% non-volatile content.

[Manufacture of topics (2) to (9)]

As in the case of subject (1), polyester polyol solutions (1) to (7) and other components shown below were mixed in the ratio (g) shown in Table 1, and then ethyl acetate was added to make the non-volatile content 50%. Topics (2) to (9) were obtained.

In addition, the main ingredient (7) is a combination of 100 g of polyester polyol solution (6) (solid content 50 g) and 100 g of polyester polyol solution (7) (solid content 50 g).

<Other ingredients>

KBM-403:3-Glycidoxypropyl Trimethoxy Silane (Shin-Etsu Silicone Co., Ltd. product)

KBM-903:3-Aminopropyl trimethoxy silane (manufactured by Shin-Etsu Silicone Co., Ltd.)

phosphoric acid

<Hardener (1)>

90 parts by mass of the adduct body obtained by adding trimethylolpropane to 4,4'-diphenylmethane diisocyanate and 10 parts by mass of the nurate body of hexamethylene diisocyanate were mixed, diluted with ethyl acetate, and mixed with a resin solution with a solid content of 70%. This was used as the curing agent (1). The NCO% of hardener (1) was 11.1%. Here, NCO% represents the mass ratio (%) of the isocyanate group (-NCO) based on the total mass of the curing agent.

<Hardener (2)>

70 parts by mass of the adduct body obtained by adding trimethylolpropane to 4,4'-diphenylmethane diisocyanate and 30 parts by mass of the nurate body of hexamethylene diisocyanate were mixed, diluted with ethyl acetate, and mixed with a resin solution with a solid content of 70%. What was used was used as hardener (2). The NCO% of curing agent (2) was 12.0%.

<Hardener (3)>

50 parts by mass of the adduct body obtained by adding trimethylolpropane to 4,4'-diphenylmethane diisocyanate and 50 parts by mass of the nurate body of hexamethylene diisocyanate were mixed, diluted with ethyl acetate, and mixed with a resin solution with a solid content of 70%. What was used was used as hardener (3). The NCO% of hardener (3) was 12.9%.

<Hardener (4)>

70 parts by mass of an adduct of trimethylolpropane added to 4,4'-diphenylmethane diisocyanate and 30 parts by mass of an adduct of hexamethylene diisocyanate with trimethylolpropane were mixed, diluted with ethyl acetate, and the solid content was 70. % resin solution was used as the curing agent (4). The NCO% of hardener (4) was 10.9%.

<Hardener (5)>

70 parts by mass of the adduct body obtained by adding trimethylolpropane to 4,4'-diphenylmethane diisocyanate and 30 parts by mass of the biuret body of hexamethylene diisocyanate were mixed, diluted with ethyl acetate, and made into a resin solution with a solid content of 70%. This was used as the hardener (5). The NCO% of hardener (5) was 12.4%.

<Hardener (6)>

100 parts by mass of the adduct obtained by adding trimethylolpropane to 4,4'-diphenylmethane diisocyanate was diluted with ethyl acetate to obtain a resin solution with a solid content of 70%, which was used as the curing agent (6). The NCO% of hardener (6) was 10.6%.

<Hardener (7)>

30 parts by mass of the adduct body obtained by adding trimethylolpropane to 4,4'-diphenylmethane diisocyanate and 70 parts by mass of the biuret body of hexamethylene diisocyanate were mixed, diluted with ethyl acetate, and made into a resin solution with a solid content of 70%. This was used as the hardener (7). The NCO% of hardener (7) was 13.9%.

<Hardener (8)>

100 parts by mass of the nurate form of hexamethylene diisocyanate was diluted with ethyl acetate to obtain a resin solution with a solid content of 70%, which was used as the curing agent (8). The NCO% of hardener (8) was 15.3%.

<Hardener (9)>

100 parts by mass of an adduct obtained by adding trimethylolpropane to trilene diisocyanate was diluted with ethyl acetate to obtain a resin solution with a solid content of 70%, which was used as the curing agent (9). The NCO% of hardener (9) was 12.0%.

(Examples 1 to 14, Comparative Examples 1 to 6, Reference Examples)

For each base material and each curing agent, the equivalent ratio of the isocyanate group contained in the hardener to the sum of the hydroxyl and carboxyl groups derived from the polyol (A) contained in the base material [NCO]/([OH]+[COOH]) is shown in Table 3. After mixing to the value shown in 4, ethyl acetate was added so that the non-volatile content was 30%, and a polyurethane adhesive for the outer layer was obtained.

A coating type chromate phosphate treatment agent (Surfcoat NR-X, manufactured by Nippon Paint Co., Ltd.) is applied to one side of a 40㎛ thick aluminum foil in an amount of 0.1g/m2, baked at 230°C, and applied as an outer layer on the surface of the treatment agent. As an adhesive, the polyurethane adhesive was applied using a dry laminator in an application amount of 5 g/m2, the solvent was volatilized, and a stretched polyamide film with a thickness of 30 μm was laminated.

Next, apply the following inner layer adhesive to the other side of the aluminum foil of the obtained laminated film using a dry laminator in an amount of 5 g/m2 after drying, and after volatilizing the solvent, an unstretched polypropylene film with a thickness of 30 ㎛ is formed. After lamination, curing (aging) was performed for 7 days at the aging temperature shown in Tables 3 and 4, and the adhesives for the outer layer and inner layer were cured to obtain a battery packaging material.

*Adhesive for inner layer

AD-502 (polyester polyol manufactured by Toyo Morton Co., Ltd.) is used as the main agent, and CAT-10L (isocyanate-based curing agent manufactured by Toyo Morton Co., Ltd.) is mixed in a mass ratio of main/curing agent = 100/10, with a non-volatile content of 30%. Ethyl acetate was added to create an adhesive for the inner layer.

(Comparative Example 7)

AD-502 (polyester polyol manufactured by Toyo Morton Co., Ltd.) was used as the base material, and CAT-10 (isocyanate curing agent manufactured by Toyo Morton Co., Ltd.) was mixed with the hardener in a mass ratio of base/curing agent = 100/10, with a non-volatile content of 30%. ethyl acetate and polyurethane adhesive were obtained so that the % was obtained.

A battery packaging material was obtained in the same manner as in the above Examples and the above Comparative Examples except that the obtained polyurethane adhesive was used as the outer layer adhesive.

<Storage modulus at 120℃>

Apply the polyurethane adhesive for the outer layer on the release paper so that the dry film thickness is about 60㎛, leave it at 25℃ for one day, and then age it for 2 weeks at the aging temperature shown in Tables 3 and 4. Then, peel the adhesive layer from the release paper and collect the sample. get The sample pieces were cut to 5 mm in width and 3 cm in length, and kept in a dynamic viscoelasticity measurement device (DVA-200, manufactured by IT Measurement and Control Co., Ltd.) with a distance between zippers of 2 cm, and heated to -20°C at a temperature increase rate of 10°C/min. The generated stress was measured at a frequency of 10 Hz in environments ranging from to 200°C.

In addition, in the storage elastic modulus measurement, the dry film thickness was large, so the aging time was set to 2 weeks.

The battery packaging material obtained as described above was subjected to performance evaluation according to the evaluation method below.

<Heat-resistant adhesive strength>

The battery packaging material was cut into pieces of 200 mm The peel strength (N/15 mm width) between the stretched polyamide film and aluminum foil was expressed as the average value of five specimens each. The results are shown in Tables 3 and 4.

+++: 3.5N or more (excellent for practical purposes)

++: 3.0N or more but less than 3.5N (practical range)

+: 2.5N or more, less than 3.0N (lower practical limit)

-: Less than 2.5N

<Heat seal resistance before and after deformation>

(heat seal resistance before deformation)

The battery packaging material was cut to a size of 60 x 60 mm and used as a blank (material to be molded). The blank is subjected to single-stage overhanging molding with the stretched polyamide film on the outside using a molding height-free, i.e. straight mold whose molding height can be freely changed, and the four sides of the flange are molded at 190°C·2kgf·3. Heat sealed in seconds. The evaluation of formability used as an index the maximum formable height within the range where the aluminum foil does not break or the layers between each layer are not lifted.

(Heat seal resistance after deformation)

In the same manner as above, after one-stage overhanging was formed, the four overhanging corners were directly recessed, bent and wrinkled to deform, and then the four sides of the flange were heat-sealed at 190°C, 2kgf, and 3 seconds. The evaluation of formability used as an index the maximum formable height within the range where the aluminum foil does not break or the layers between each layer are not lifted.

The punch shape of the mold used was square with a side of 29.4 mm, corner R1 mm, and punch shoulder R1 mm. The die hole shape of the mold used was square with a side of 30.0 mm, die hole corner R:2 mm, die tm hole shoulder R:1 mm, and the gap between the punch and die hole was 0.3 mm. A slope according to the design height occurs due to the clearance. Depending on the height of molding, the following four stages of evaluation were performed.

+++: 6mm or more (excellent for practical purposes)

++: 5 mm or more but less than 6 mm (practical range)

+: 3 mm or more but less than 4 mm (lower practical limit)

-: Less than 3mm

The above results are shown in Tables 3 and 4.

[Table 1]

[Table 2]

[Table 3]

[Table 4]

From the results in Table 3, the following considerations were made. In each of the above examples, the outer layer side adhesive layer is a polyester polyol having a specific number average molecular weight, and the aromatic polyacid component among the polyacid components accounts for a specific mole % of the polyester polyol, and the adhesive contains a specific polyisocyanate component. It comes true. It can be seen that even when aging is performed at less than 60°C for a laminate obtained using an adhesive having this structure, a battery packaging material with excellent heat-resistant adhesive strength can be provided. Additionally, this battery packaging material can provide a molded product with excellent heat sealing resistance before and after deformation of the molded product.

The polyhydric acid component used in Comparative Example 1 had a significantly higher content of aromatic polyacid component than that in the Examples. In Comparative Example 1, the polyol component (A), which is a reaction product of this polyhydric acid component and polyhydric alcohol, is used for coating. For this reason, it becomes excessively brittle in comparison, and the heat-sealing resistance of the molded product before and after deformation decreases. Meanwhile, in Comparative Example 2, the content of the aromatic polyacid component was significantly lower than that in the Example. In Comparative Example 2, the polyol component (A), which is a reaction product of this polyhydric acid component and polyhydric alcohol, is used for coating. For this reason, in Comparative Example 2, heat-resistant adhesiveness decreases.

Comparative Example 3 does not include a polyfunctional derivative of hexamethylene diisocyanate in the polyisocyanate component (B). For this reason, the flexibility of the molded product decreases and the heat-sealing resistance before and after deformation of the molded product decreases. On the other hand, in Comparative Example 4, the amount of diphenylmethane diisocyanate adduct in the polyisocyanate component (B) was significantly less than in the Example. The adhesive layer of Comparative Example 5 did not contain diphenylmethane diisocyanate adduct. For this reason, in Comparative Examples 4 and 5, the storage modulus of the adhesive layer at 120°C decreased and the heat sealing resistance of the molded product also decreased.

In addition, when trilene diisocyanate is used as the polyisocyanate component (B), curing is completely completed by aging at 60°C for 7 days as in the reference example. For this reason, the storage modulus of the adhesive layer at 120°C increases and the heat resistance of the molded product improves. However, at 40°C and 7 days of aging, it is difficult for the adhesive layer to soften before or during curing. Also, the activity of isocyanate is reduced. For this reason, the curing of the adhesive layer is insufficient, and the heat resistance of the molded product decreases.

The battery packaging material according to the present invention has excellent moldability and high environmental resistance. Therefore, it is also used as a laminate for outdoor industrial purposes, such as laminates requiring formability such as PTP packaging or steel plates, and buildings such as barrier materials, roofing materials, solar panel materials, window materials, outdoor flooring materials, lighting protection materials, and automobile parts. possible.

11: Outer layer side resin film layer
12: Outer layer side adhesive layer
13: Metal foil layer
14: Inner layer side adhesive layer
15: heat seal layer

Claims (5)

In the battery packaging material, which is formed by sequentially stacking an outer resin film layer (11), an outer adhesive layer (12), a metal foil layer (13), an inner adhesive layer (14), and a heat seal layer (15),
The outer layer side adhesive layer 12 is a cured product produced by reaction between a polyol component (A) and a polyisocyanate component (B),
The polyol component (A) is a polyhydric acid component in which the aromatic polyhydric acid component accounts for 55 to 85 mol% of 100 mol% of the polyhydric acid component and a polyhydric alcohol component, and has a number average molecular weight of 10,000 to 40,000. is an ester polyol, or
or
The polyol component (A) is a mixture of the reaction product (1) of the polyacid component (1) and the polyhydric alcohol component (1) and the reaction product (2) of the polyacid component (2) and the polyhydric alcohol component (2), , In addition, of the total 100 mol% of the polyacid component (1) and the polyacid component (2), the aromatic polyacid component accounts for 55 to 85 mol%, and the number average molecular weight of the mixture is 10,000 to 40,000, It is a polyester polyol,
The polyisocyanate component (B) contains an adduct produced by adding a trifunctional alcohol to diphenylmethane diisocyanate and a polyfunctional derivative of hexamethylene diisocyanate, and diphenylmethane di in 100 mol% of isocyanate groups. Isocyanate groups derived from isocyanate account for 40 to 90 mol%.
Characterized in that the equivalent ratio of the isocyanate group contained in the polyisocyanate component (B) to the total of the hydroxyl group and carboxyl group contained in the polyol component (A) [NCO]/([OH] + [COOH]) is 15 or more. Packaging material for batteries.
The method of claim 1, wherein the equivalent ratio of the isocyanate group contained in the polyisocyanate component (B) to the sum of hydroxyl groups and carboxyl groups contained in the polyol component (A) [NCO]/([OH]+[COOH]) A packaging material for batteries, characterized in that the value is 15 to 30.
The battery packaging material according to claim 1, wherein the outer resin film layer (11) is a polyamide film or a polyester film, and the heat sealing layer (15) is a polyolefin-based film.
In the battery container formed by molding the battery packaging material according to any one of claims 1 to 3, the outer layer side resin film layer (11) constitutes the surface on the convex side, and the heat seal layer (15) constitutes the concave side. A battery container constituting the surface of the side.
A battery equipped with the battery container described in paragraph 4.