TW201825634A - Adhesive composition, laminate, packaging material for electric storage device, container for electric storage device and electric storage device characterized by excellent adhesion and durability under conditions that are easily exposed to the electrolyte solution, as well as higher level of durability when immersed in an electrolyte solution - Google Patents

Abstract

The present invention provides an adhesive composition for laminate which can maintain a high adhesion strength without causing an appearance defect in the molded portion., a packaging material for electric storage device, a container for electric storage device and an electric storage device. The adhesive composition comprises a polyolefin resin component and a curing agent, and the polyolefin resin component comprises a polyolefin resin having a carboxyl group or an acid anhydride group, a melting point of 55 DEG C to 100 DEG C, a weight average molecular weight of 40,000 to 400,000; and a polymer having a carboxyl group or an acid anhydride group, a weight average molecular weight of 200 to 13000. Relative to the total 100wt% of polyolefin resin and the polymer, the content of the polymer is 0.2wt% to 5.0wt%. The curing agent comprises at least one selected from the group consisting of isocyanate group, epoxy group, carbodiimide group, aziridine group.

Description

Adhesive composition, laminate, packaging material for power storage element, container for power storage element, and power storage element

The present invention relates to an adhesive composition. Moreover, this invention relates to the laminated body which laminated | stacked the metal foil and the heat-fusion resin film using the said adhesive composition, and the packaging material for electrical storage elements. Furthermore, this invention relates to the container for electrical storage elements which processed the said packaging material for electrical storage elements so that the said thermofusion resin film became an inner surface, and the electrical storage element which used the said container for electrical storage elements.

The secondary battery is a representative power storage element. Due to the rapid development of electronic devices such as mobile phones and portable personal computers, the demand for lightweight and compact secondary batteries such as lithium-ion batteries is increasing. As the outer body of the secondary battery, metal cans have been used before, but in terms of weight reduction and productivity, packaging materials made of laminated plastic films or metal foils have gradually become mainstream. As the simplest packaging material for storage elements (hereinafter also referred to as a packaging material), as shown in FIG. 1, the outer layer side resin film (11), the outer layer side adhesive layer (12), and the metal foil are included in this order from the outer layer side. (13) A laminated body of an inner layer side adhesive layer (14) and a heat-welded resin film (15). As shown in FIG. 2, the battery container is formed by forming the packaging material (deep drawing molding processing, drawing molding processing, etc.) in a manner that the outer resin film (11) forms a convex surface and the heat-welded resin film (15) forms a concave surface. ). Then, an electrode, an electrolyte solution, and the like are sealed in the concave surface side of the battery container and sealed, thereby manufacturing a battery. In addition, capacitors (capacitors) are also one of the power storage elements. Among them, lithium ion capacitors are expected to grow in the market in the future.

In the packaging material for a storage battery element, the following properties are mainly required for the inner-layer-side adhesive layer for bonding a metal foil and a heat-welded resin film. (1) The bonding strength between the metal foil and the heat-welded resin film is high. (2) The inner-layer-side adhesive layer is resistant to an electrolyte solution. That is, even if the electrolyte is sealed in the battery container, the adhesion strength between the metal foil and the heat-welded resin film can be maintained. For example, the electrolyte solution of a lithium battery includes a lithium salt (electrolyte) such as lithium hexafluorophosphate, and solvents such as propylene carbonate, ethylene carbonate, diethyl carbonate, and dimethyl carbonate. When the electrolyte solution put in the container for an electricity storage device passes through the heat-welded resin film and reaches the adhesive layer, the adhesion strength between the heat-welded resin film and the metal foil is reduced. In addition, when moisture penetrates into the electrolyte solution from the outside of the battery container, a lithium salt such as lithium hexafluorophosphate reacts with water to generate hydrofluoric acid. The generated hydrofluoric acid becomes a factor that degrades the heat-welded resin film and the adhesive layer, and if it passes through the heat-welded resin film and the adhesive layer and reaches the metal foil, the metal foil is corroded. In the case of metal corrosion, the bonding strength between the heat-welded resin film and the metal foil is significantly reduced. Therefore, in addition to the resistance of the electrolyte itself, the inner-layer-side adhesive layer in which the heat-welded resin film and the metal foil are bonded is also required to have a substance produced by acting on the electrolyte from an input from the outside of the storage element. Tolerance.

In order to achieve the performance required as an inner-layer-side adhesive, Patent Document 1 (Japanese Patent Laid-Open No. 2003-123708) discloses an adhesive containing an acid-modified thermoplastic elastomer (A) and a coupling agent (B). combination. Furthermore, a secondary battery using a laminate as a packaging material is disclosed, in which the adhesive composition is used for lamination of an unstretched polypropylene film and an aluminum foil formed by laminating a nylon film, and includes Unstretched polypropylene film / adhesive layer / aluminum foil / nylon film. Furthermore, it is disclosed that an adhesion-imparting agent can be included in the adhesive composition.

Patent Document 2 (WO2004 / 041954) discloses an adhesive composition comprising a carboxyl group-containing thermoplastic elastomer (A), a polyolefin polyol (B), an adhesion imparting agent (C), and a polyfunctional isocyanate (D ). Furthermore, a laminate is disclosed in which an aluminum foil or a polyethylene terephthalate film is bonded to an unstretched polypropylene film using the adhesive. In addition, Patent Document 3 (Japanese Patent Laid-Open No. 2005-063685) discloses an adhesive that uses a polyolefin polyol and a polyfunctional isocyanate hardener as essential components, and describes a packaging material for a battery case, which uses the same This adhesive adheres an aluminum foil to a thermoplastic resin film, and sets the thermoplastic resin film as an inner layer.

Patent Document 4 (WO2009 / 087776) discloses an adhesive composition having a polyolefin resin having a melting energy of 5 mJ / mg to 15 mJ / mg and a carboxyl group, and a polyfunctional isocyanate. In addition, Patent Document 5 (Japanese Patent Laid-Open No. 2010-092703) discloses an adhesive which is made of a polyolefin resin having a carboxyl group and a polyfunctional isocyanate compound, and has the following gist: An aluminum foil and a thermoplastic resin film are bonded together with an adhesive, and the thermoplastic resin film is used as a packaging material for a battery case in an inner layer.

[Problems to be Solved by the Invention] With the expansion of use in vehicle-mounted or home power storage, there is a demand for large-capacity power storage devices, long-term durability, and safety. Particularly in automotive applications, it is required to maintain excellent adhesion and durability even when exposed to an electrolyte solution. In particular, in a packaging material that has been processed, a film or an adhesive is stretched during molding, and therefore a higher level of durability such as no floating when immersed in an electrolyte solution is required.

The adhesives described in Patent Documents 1 to 3 exhibit sufficient adhesive strength, but there is a problem that the crosslinked structure of the adhesive is deteriorated due to long-term immersion in the electrolyte solution, and sufficient adhesive strength cannot be maintained. In addition, compared with Patent Documents 1 to 3, the adhesives described in Patent Documents 4 and 5 improve the durability of the crosslinked structure in the adhesives, and therefore, the long-term electrolyte solution resistance is improved, but they are still insufficient. In particular, when forming a packaging material, there is a problem that the appearance of the formed portion is poor or floats due to long-term immersion in the electrolyte solution.

The present invention has been made in view of the background, and an object thereof is to provide an adhesive agent capable of forming a laminated body that does not cause appearance defects in the molded portion even if immersed in an electrolyte solution for a long period of time and maintains a high level of adhesive strength. combination. Another object of the present invention is to provide a packaging material for a power storage element, a container for a power storage element, and a power storage element that are more excellent in electrolyte solution resistance than before. [Technical means to solve the problem]

The inventors of the present invention have made intensive studies and found that the problems of the present invention can be solved in the following embodiments, and the present invention has been completed. [1] An adhesive composition comprising a polyolefin resin component and a hardener (C), the polyolefin resin component including: a polyolefin resin (A), having a carboxyl group or an acid anhydride group, and having a melting point of 55 ℃ ~ 100 ℃, the weight average molecular weight is 40,000 to 400,000; and the polymer (B) has a carboxyl group or an acid anhydride group, and the weight average molecular weight is 200 to 13000; the polyolefin resin (A) and the polymer (B) The total amount of 100% by weight contains 0.2 to 5.0% by weight of the polymer (B), and the hardener (C) has a material selected from the group consisting of an isocyanate group, an epoxy group, a carbodiimide group, and an aziridine. At least one functional group in a group of radicals.

[2] The adhesive composition according to [1], wherein the polymer (B) has an acid value X (mmol / g) of 1.2 to 20. [3] The adhesive composition according to [1] or [2], wherein the polyolefin resin (A) has an acid value P (mmol / g) of 0.02 to 1.2. [4]: The adhesive composition according to any one of [1] to [3], wherein the polyolefin resin (A) is i (g), and the polymer is When (B) is set to j (g) and the functional group of the hardener is set to Z (mmol), Z / (P * i + X * j) is 0.3 to 10.

[5]: The adhesive composition according to any one of [1] to [4], wherein the polymer (B) is a homopolymer (b- 1) or a polymer (b-2) of an unsaturated carboxylic acid or an anhydride thereof and at least one selected from the group consisting of an aromatic vinyl compound, an aliphatic α-olefin compound, and a conjugated diene compound . [6] The adhesive composition according to any one of [1] to [5], wherein the melting point of the polyolefin resin (A) is 65 ° C to 90 ° C, and the weight average molecular weight is 100,000 to 300,000.

[7]: A laminated body, characterized by having an adhesive layer between the metal foil and the heat-welded resin film layer, wherein the adhesive layer is as described in any one of [1] to [6] An adhesive composition is formed. [8]: The laminated body according to [7], characterized in that: a surface treatment layer is provided between the metal foil and the adhesive layer, and the surface treatment layer is made with a hardener (C) A reactive treating agent is formed. [9]: The laminate according to [8], wherein the treatment agent includes at least one selected from the group consisting of a carboxyl group, a hydroxyl group, and an amino group.

[10]: A packaging material for a power storage element, which requires an outer layer resin film, an outer layer adhesive layer, a metal foil, an inner layer adhesive layer, and a heat fusion resin film in order from the outside, and the packaging material for a power storage element. The internal layer side adhesive layer is formed of the adhesive composition according to any one of [1] to [6].

[11]: A container for a power storage element, which is formed of the packaging material for a power storage element according to [10], wherein the container for the power storage element has an inner surface formed by a heat-welded resin film. [12] A power storage element characterized by using the container for a power storage element according to [11].

[Effects of the Invention] According to the present invention, it is possible to provide an adhesive composition that can form a laminate that can maintain a high level of adhesive strength without causing appearance defects in the molded portion even when immersed in the electrolyte solution for a long time. In addition, the present invention can provide a packaging material for a power storage element, a container for a power storage element, and a power storage element that are more excellent in electrolyte solution resistance than before.

Hereinafter, embodiments of the present invention will be described in detail. The description of “arbitrary number A to arbitrary number B” in the present specification is a range of the index A and the number greater than A, and the number B and the number less than B. As shown in FIG. 1, the packaging material for a storage battery element according to this embodiment includes an outer-layer-side resin film (11), an outer-layer-side adhesive layer (12), a metal foil (13), an inner-layer-side adhesive layer (14), and The heat-sealing resin film (15) is laminated in this order. The outer-layer-side adhesive layer (12) has a function of laminating (bonding) the outer-layer-side resin film (11) and the metal foil (13). The inner-layer-side adhesive layer (14) functions to laminate (bond) the metal foil (13) and the heat-welded resin film (15).

The container for an electric storage element of this embodiment is formed using the packaging material for an electric storage element of this embodiment, and its form is not specifically limited. As a preferred example, a tray-shaped container for a power storage element such as that shown in FIG. 2 may be mentioned. In the example of FIG. 2, a heat-sealing resin film (15) is disposed inside the tray, that is, the concave side forming a space for accommodating an electrode, an electrolyte solution, or the like, and an outer layer resin film is disposed outside the tray, ie, the convex side. (11). In addition to the tray shape, a container (for example, a cylindrical shape, a rectangular shape, an oval shape, or the like) for a storage battery element is also preferable. These power storage element containers are generally obtained by molding a packaging material for a power storage element in a flat state. The inner side of the container for an electric storage element, that is, the surface that is in contact with the electrolyte solution and the like is a heat-welded resin film (15). The heat-welded resin film (15) that connects the flange portion of the heat-welded resin film (15) and the flange portion of the heat-welded resin film (15) constituting the packaging material for other power storage elements or the container for other power storage elements. The flange portions facing each other are in contact with each other and are heated, whereby the heat-welding resin films (15) are welded to each other, and a storage element member such as an electrolyte solution or an electrode is sealed. In addition to the tray shape, the container for a power storage element according to this embodiment includes a bag-shaped container (pouch type).

In a container for an electric storage device, the side close to the electrolyte solution is generally called "inside" and "inner layer" with the metal foil (13) as the boundary, and the side far away from the electrolyte solution is called "outer side" and "outer layer". . Therefore, in a predetermined packaging material for a storage element forming a container for a storage element, a predetermined side close to the electrolyte solution is also referred to as "inside" and "inner layer" with the metal foil (13) as a boundary, and will be far away from the electrolyte. The predetermined side of the solution is called "outer side", "outer layer".

The adhesive composition of this embodiment can be preferably used to form the inner-layer-side adhesive layer (14). In a state where the adhesive composition of this embodiment is sandwiched between the metal foil (13) and the heat-welded resin film (15), a carboxyl group or an acid anhydride group in the polyolefin resin (A) and the polymer (B The carboxyl group or acid anhydride group in) and the functional group in the hardener (C) having reactivity with these carboxyl group or acid anhydride group can form a fine and strong crosslinked structure. As a result, a sufficient bonding strength can be exhibited, and even if immersed in a high-temperature electrolyte solution for a long period of time, the bonding strength can be maintained at a high level.

<Polyolefin resin component> The polyolefin resin component includes: a polyolefin resin (A) having a carboxyl group or an acid anhydride group, a melting point of 55 ° C to 100 ° C, a weight average molecular weight of 40,000 to 400,000; and a polymer (B), It has a carboxyl group or an acid anhydride group, and has a weight average molecular weight of 200 to 13,000. The content of the polymer (B) with respect to 100% by weight of the polyolefin resin (A) and the polymer (B) is set to 0.2 to 5.0% by weight.

<Polyolefin resin (A)> The polyolefin resin (A) is preferably a polyolefin resin (A) in order to be soluble in a solvent used in the adhesive composition, or storage stability of the dissolved solution (stable storage without precipitation). With amorphous parts. On the other hand, in order to improve the electrolyte solution resistance of the adhesive layer in the laminate, it is preferable that the adhesive layer also has a crystalline portion, and the balance between the amorphous portion and the crystalline portion is important. The polyolefin resin (A) used in this embodiment has a weight average molecular weight of 40,000 to 400,000 and a melting point of 55 ° C to 100 ° C.

The polyolefin resin (A) has a weight-average molecular weight of 40,000 to 400,000, and thus easily has both the storage stability of the solution of the polyolefin resin (A) constituting the adhesive composition and the electrolyte-resistant solution of the packaging material for the storage element Properties, heat sealability, applicability. The Mw of the polyolefin resin (A) is more preferably 100,000 to 400,000, and still more preferably 100,000 to 300,000. In other words, if the Mw of the polyolefin resin (A) is less than 40,000, the polymer chain of the polyolefin resin (A) may be insufficiently crosslinked, and thus the film strength of the adhesive layer may be low and the electrolyte solution resistance may be insufficient. In addition, if Mw is more than 400,000, the storage stability of the polyolefin resin (A) solution at 25 ° C. may be reduced, or the viscosity of the adhesive solution may be too high to deteriorate the coatability.

The polyolefin resin (A) has a melting point of 55 ° C to 100 ° C, and thus satisfactorily satisfies the bonding strength (initial stage, after impregnation with an electrolyte solution) or heat-sealability of a battery packaging material. In other words, if the melting point of the polyolefin resin (A) is less than 55 ° C, there is a possibility that the adhesive strength or heat-sealability after the electrolyte solution is impregnated may decrease. When the melting point is higher than 100 ° C, the bonding strength (initial stage, after the electrolyte solution is impregnated) may decrease. The melting point of the polyolefin resin (A) is more preferably 60 ° C to 90 ° C, and still more preferably 65 ° C to 85 ° C.

The melting energy (ΔE) of the polyolefin resin (A) is preferably 15 (mJ / mg) to 50 (mJ / mg). If it is in the said range, it is excellent in the adhesive strength or heat-sealability after impregnation of an electrolyte solution, and the storage stability of a polyolefin resin (A) solution is also excellent. The melting energy (ΔE) of the polyolefin resin (A) is more preferably 20 (mJ / mg) to 50 (mJ / mg), and still more preferably 20 (mJ / mg) to 40 (mJ / mg).

In the present specification, "having storage stability" means as follows: 10 g of resin is added to a mixed solvent of 40 g of toluene, 40 g of methylcyclohexane, and 10 g of methyl ethyl ketone, and the resin is heated to dissolve and obtain After the transparent solution, it was left to stand at 4 ° C for 1 day and again at 25 ° C for 1 day. At this time, the fluidity was maintained without any change in appearance such as gelation or precipitation.

Here, the heat-sealability will be described. In addition to adhesive strength and electrolyte solution resistance, a packaging material for a storage battery element is also required to be excellent in heat sealability. The heat-sealable resin film (15) (heat-sealing layer) functions to seal a power storage element member such as an electrolyte solution or an electrode in a power storage element container. Specifically, the heat-welding resin film (15) constituting the container for the power storage element is arranged to face the heat-welding resin film (15) of the same or other container for the power storage element (the packaging material for the power storage element), and the heat is used to make each other By welding, the container for an electric storage element is sealed. From the viewpoint of securing heat seal strength (peel strength between the heat-welded resin films (15)), heat seal under high temperature and high pressure is preferred. However, if the adhesive layer (14) bonding the heat-welded resin film (15) to the metal foil (13) is melted or deformed due to heat and pressure during heat sealing, the electrode terminal and the metal foil (13) may be caused. ) Conduction. When conducting, it does not function as a power storage element. Therefore, it is required that the insulation between the electrode terminal and the metal foil (13) is not damaged by heat sealing, and that the adhesive layer (14) is not melted or deformed by heat and pressure during heat sealing. The use of a polyolefin resin (A) having a melting point or melting energy (ΔE) within the above range is preferable because it is easy to suppress and prevent melting or deformation of the adhesive layer (14) during heat sealing.

The polyolefin resin (A) needs to have a carboxyl group or an acid anhydride group, and forms a strong cross-linked structure by the reaction of the carboxyl group or the acid anhydride group with a hardener (C) described later, thereby exhibiting sufficient adhesion strength and resistance to electrolyte solution . From the viewpoint of excellent adhesion and solubility, the polyolefin resin (A) preferably has an acid value P (mmol / g) of 0.02 to 1.2. If it is in the said range, it will be excellent in adhesive strength or durability in an electrolyte solution by a crosslinking reaction. In addition, crosslinking shrinkage of a coating film due to excessive crosslinking is unlikely to occur, and the adhesive strength and solubility in a solvent are excellent.

Examples of the method for introducing a carboxyl group or an acid anhydride group include a method of graft-polymerizing an ethylenically unsaturated carboxyl group or an acid anhydride thereof to a polyolefin resin (A1) having no carboxyl group or an acid anhydride group, or an olefin monomer and ethylene A method for copolymerizing an unsaturated unsaturated carboxylic acid or its anhydride. In addition, a polyolefin having a carboxyl group can also be obtained by reacting an acid anhydride group of a polyolefin having an acid anhydride group with water, an alcohol, or the like. Among these, a modified polyolefin resin obtained by graft-polymerizing an ethylenically unsaturated carboxyl group or an acid anhydride thereof onto a polyolefin resin (A1) having no carboxyl group or acid anhydride group is preferred. The polyolefin resin (A) may be used singly or in combination of two or more kinds.

The method for graft polymerization of polyolefin is not particularly limited, and for example, the method disclosed in Japanese Patent Laid-Open No. 11-293216 can be used.

Examples of the free radical initiator that can be used in the graft polymerization of polyolefins include benzamidine peroxide, diisopropyl peroxide dicarbonate, di-n-propyl peroxide dicarbonate, dicumyl peroxide, Di-tert-butyl peroxide, tert-butyl peroxyneodecanoate, tert-butyl peroxy 2-ethylhexanoate, tert-butyl peroxytrimethylacetate, 2,5-dimethyl-2,5 -Well-known organic peroxides, such as a di (t-butyl peroxide) hexane, The most preferable organic peroxide can be selected according to reaction conditions. These may be used alone or in combination of two or more.

The polyolefin resin (A1) is not particularly limited, and examples thereof include homopolymerization of olefin monomers such as ethylene, propylene, 1-butene, butadiene, isoprene, 1-hexene, and 1-octene. Polymers, copolymers of olefin monomers with each other, or copolymers with other monomers, and polymers obtained mainly from hydrocarbon backbones such as hydrides or halides. Copolymers of olefin monomers are preferred.

The copolymer of olefin monomers is preferably a copolymer of 1-butene and other olefin monomers. Other olefins are preferably ethylene and propylene. Examples of copolymers of 1-butene and other olefin monomers include binary copolymers of ethylene and 1-butene, binary copolymers of propylene and 1-butene, and ethylene. The terpolymer with propylene and 1-butene is more preferably a terpolymer with propylene and 1-butene. The copolymerization ratio is preferably propylene: 1-butene = 10: 90 to 90:10 (molar ratio), and more preferably 40:60 to 80:20 (molar ratio). In the copolymer of propylene and 1-butene, the melting point may be lower than 55 ° C when the propylene content is less than 10 mol%, and the melting point may be higher than 100 ° C when the propylene content is more than 90 mol%.

The other monomers copolymerizable with the olefin monomer are not particularly limited, and examples thereof include aromatic vinyl compounds such as styrene, α-methylstyrene, and indene; methyl (meth) acrylate, (meth) acrylic acid Ethyl ester, butyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, dodecyl (meth) acrylate, (Meth) acrylic acid alkyl ester compounds such as stearyl (meth) acrylate and behenyl (meth) acrylate; cyclohexyl (meth) acrylate, isobornyl (meth) acrylate and the like have alicyclic structures (Meth) acrylate compounds; (meth) acrylate compounds with aromatic rings, such as benzyl (meth) acrylate; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate (Meth) acrylate compounds containing hydroxyl groups such as 4-hydroxybutyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, (methyl ) (Meth) acrylic acid ester compounds having an amino group such as tert-butylaminoethyl acrylate; (meth) acrylamide, dimethyl (meth) propyl Ammonium amine, dimethylaminopropyl (meth) acrylamide, isopropyl (meth) acrylamide, diethyl (meth) acrylamide, hydroxyethyl (meth) acrylamide, etc. Acrylamides; (meth) acrylonitrile, acrylamidomorpholine, etc. In terms of graft polymerizability and compatibility with polyolefin, styrene, dodecyl (meth) acrylate, and stearyl (meth) acrylate are preferred. The ethylenically unsaturated carboxylic acid is not particularly limited, and examples thereof include acrylic acid, methacrylic acid, maleic acid, fumaric acid, butenoic acid, and itaconic acid. These ethylenically unsaturated carboxylic acids or their anhydrides may be used alone or in combination of two or more.

The polymerization method of the olefin monomer is not particularly limited, and for example, a metal catalyst such as a Ziegler-Natta catalysis or a metallocene catalyst may be added using the method disclosed in Japanese Patent Publication No. 07-080948, or Polymerization can be carried out with a catalytic aid such as (methyl) aluminoxane as required.

The weight average molecular weight (Mw) of the polyolefin resin (A) was determined as follows. The HLC-8220GPC system manufactured by Tosoh Co., Ltd. obtained by connecting two TSKgel superHZM-N columns to the column temperature was 40 ° C, the eluent was tetrahydrofuran, and the flow rate was 0.35 mL per minute. The measurement was performed next. The sample was adjusted by dissolving 2 mg of polyolefin resin (A) in 5 mL of tetrahydrofuran. In addition, Mw is calculated by standard polystyrene conversion. When two or more kinds of polyolefin resins (A) are used in combination, it means the weight average molecular weight of the whole mixture.

In addition, the melting point and melting energy (ΔE) can be determined by differential scanning calorimetry (DSC) measurement in accordance with Japanese Industrial Standard (JIS) K7121. Specifically, it is calculated | required as follows. Use polyolefin resin (A) with a diameter or less than 0.5 mm on each side directly. For polyolefin resin (A) exceeding 0.5 mm, cut polyolefin resin (A) to 0.5 mm or less and place it in a container. Put about 10 mg of polyolefin resin (A). It is heated at 10 ° C per minute to a temperature about 30 ° C higher than the melting point, and then cooled at 10 ° C per minute to a temperature about 50 ° C lower than Tg. When a clear Tg cannot be observed, it is cooled to a temperature about 50 ° C lower than the melting point. After heating at a temperature of 10 ° C. per minute to a temperature higher than the melting point by about 30 ° C., the melting point was determined from the peak top of the peak corresponding to the melting at this time. In addition, ΔE is obtained from the area of the portion where the peak corresponding to the melting has departed from the base line and returned to the base line again. When two or more kinds of polyolefin resins (A) are used in combination, the melting point is calculated from the peak top of the peak on the high temperature side, and ΔE is calculated from the total of all peak areas obtained by melting.

<Polymer (B)> The polymer (B) has a carboxyl group or an acid anhydride group, and has a weight average molecular weight of 200 to 13,000. The polymer (B) reacts with the hardener (C) to form a fine cross-linked structure, suppresses swelling and penetration of the electrolyte solution, and contains a polyolefin resin component containing only the polymer (B) and the hardener (C) Compared with the adhesive layer, the resistance in the electrolyte solution can be greatly improved.

The polymer (B) can be obtained, for example, by polymerizing a monomer having an unsaturated carboxylic acid or an anhydride thereof, or by copolymerizing the monomer with another monomer.

The monomer having an unsaturated carboxylic acid or an anhydride thereof used in the present invention is not particularly limited. Examples of the monomer having a carboxyl group include acrylic acid, methacrylic acid, maleic acid, fumaric acid, and butenoic acid. , Itaconic acid, and unsaturated fatty acids such as oleic acid or linoleic acid. Examples of the acid anhydride group include maleic anhydride, itaconic anhydride, and the like. These may be used alone or in combination of two or more.

Other monomers that can be copolymerized with unsaturated carboxylic acid or its anhydride are not particularly limited, and examples thereof include aromatic vinyl compounds such as styrene, α-methylstyrene, and indene; butene, 1-hexene Aliphatic α-olefin compounds such as 1,1-octene, etc .; Conjugated diene compounds such as butadiene, isoprene, isobutene; methyl (meth) acrylate, ethyl (meth) acrylate, (meth) Butyl acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, dodecyl (meth) acrylate, stearin (meth) acrylate (Meth) acrylic acid alkyl ester compounds such as esters, behenyl (meth) acrylate; (meth) acrylic acid esters having an alicyclic structure, such as cyclohexyl (meth) acrylate and isobornyl (meth) acrylate Compounds; (meth) acrylate compounds with aromatic rings such as benzyl (meth) acrylate; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and (meth) acrylate 4 -Hydroxy-containing (meth) acrylate compounds such as hydroxybutyl ester; dimethylaminoethyl (meth) acrylate, diethyl (meth) acrylate (Meth) acrylic acid ester compounds having an amino group such as aminoethyl ester, tert-butylaminoethyl (meth) acrylate, (meth) acrylamide, dimethyl (meth) acrylamide, dimethylamino Acrylamides such as propyl (meth) acrylamide, isopropyl (meth) acrylamide, diethyl (meth) acrylamide, hydroxyethyl (meth) acrylamide; (a Group) acrylonitrile, acrylamidomorpholine, and the like. These single bodies may be used alone, or two or more of them may be used in combination.

The polymer (B) is not particularly limited, and may be any of a random polymer, a block polymer, and a graft polymer. At least a part of the acid anhydride groups in these polymers may be semi-esterified or hemiamine. Into. The semi-esterified modified product can be obtained by reacting an acid anhydride with a known alcohol by using a known half-esterification reaction method. The hemi-amination modified product can be obtained by reacting an acid anhydride with a known amine using a known hemi-amination reaction method.

The polymer (B) may be a dimer or trimer of an unsaturated fatty acid, and these are also referred to as a dimer acid. In addition, the unsaturated bond may be hydrogenated. The hydrogenated modified product can be obtained by reacting an unsaturated group of the polymer (B) with hydrogen using a known hydrogenation method.

As a preferable example of a polymer (B), the homopolymer (b-1) of an unsaturated carboxylic acid or its anhydride is mentioned. The polymer (B) is also preferably at least one selected from the group consisting of an unsaturated carboxylic acid or an anhydride thereof, and an aromatic vinyl compound, an aliphatic α-olefin compound, and a conjugated diene compound. Polymer (b-2). By using the polymers (b-1) and (b-2), it is difficult to cause the appearance of the molded portion to be poor when it is immersed in the electrolyte solution for a long time. The aliphatic α-olefin compound is preferably an α-olefin having 6 to 30 carbon chains.

Examples of the homopolymer (b-1) of an unsaturated carboxylic acid or an anhydride thereof include a maleic acid polymer, polyacrylic acid, a polymer of an unsaturated fatty acid, or a dimer acid or a hydride thereof, and a polymerization of maleic anhydride. Products or their semi-esterified products or hemi-aminated products.

Examples of the unsaturated carboxylic acid or its anhydride and at least one polymer (b-2) selected from the group consisting of an aromatic vinyl compound, an aliphatic α-olefin compound, and a conjugated diene compound include horses. Maleic anhydride / styrene copolymers, maleic anhydride / α-olefin copolymers, maleic anhydride / isobutylene copolymers, polybutadiene / maleic anhydride graft polymers, or semi-esterified or semi-fluorinated polymers of these polymers Amine and so on.

As the radical initiator used when the polymer (B) is produced by a radical reaction, a known azo-based compound or an organic peroxide can be used. Examples of the azo compound include 2,2'-azobis (isobutyronitrile), 2,2'-azobis-2,4-dimethylvaleronitrile, and 2,2'- Azobis (4-methoxy-2,4-dimethylvaleronitrile), 1,1'-azobis-cyclohexane-1-carbonitrile and the like. Examples of the organic peroxide include benzamidine peroxide, diisopropyl peroxydicarbonate, di-n-propyl peroxydicarbonate, dicumyl peroxide, di-tert-butyl peroxide, and peroxyl. Oxidized tert-butyl neodecanoate, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxytrimethylacetate, 2,5-dimethyl-2,5-di (tert-butyl peroxide) Hexane. These may be used alone or in combination of two or more. From the viewpoint of excellent reactivity, it is preferable to use an organic peroxide.

The polymer (B) has a weight average molecular weight of 200 to 13,000, and has excellent compatibility with the polyolefin resin (A), and can obtain an adhesive excellent in storage stability of the solution or hardening property of the adhesive. The weight average molecular weight of the polymer (B) having a carboxyl group or an acid anhydride group is more preferably 300 to 10,000. In other words, if the weight average molecular weight of the polymer (B) is less than 200, there is a possibility that the mechanical strength of the adhesive layer becomes low and the resistance to the electrolyte solution becomes insufficient. In addition, if the weight average molecular weight is more than 13,000, compatibility with the polyolefin resin (A) may be deteriorated, the storage stability of the adhesive solution may be deteriorated, or the adhesive film may be whitened to deteriorate the adhesive force.

From the viewpoint of obtaining an adhesive having excellent durability in an electrolyte solution, the polymer (B) preferably has an acid value X (mmol / g) of 1.2 to 20. If it is in the said range, it will be excellent in durability in an electrolyte solution by a crosslinking reaction. In addition, it has excellent compatibility with the polyolefin resin (A), and the strength is optimized.

The polymer (B) contains 0.2 to 5% by weight based on 100% by weight of the sum of the polyolefin resin (A) and the polymer (B) having a carboxyl group or an acid anhydride group, and an excellent solution in the electrolyte solution can be obtained. Durability. More preferably, it is 0.5 to 4 weight%. In other words, if the content of the polymer (B) is less than 0.2% by weight, the adhesion strength may be lowered when the electrolyte solution is immersed for a long period of time, or the appearance of the formed portion may be defective. In addition, if the content is more than 5% by weight, there is a possibility that the adhesive film becomes too hard and the adhesive force may be deteriorated, or the durability in the electrolyte solution may be deteriorated.

<Other polyolefin resins> In the present embodiment, in addition to the polyolefin resin (A) having a carboxyl group or an acid anhydride group, a polyolefin having no carboxyl group or an acid anhydride group may be used in combination, as long as the effect of the invention is not impaired. Resin is used as the polyolefin resin component. The content of other polyolefin resins is not particularly limited, and it is preferably less than 70% by weight, more preferably less than 50% by weight, and even more preferably less than 30% by weight, out of 100% by weight of the polyolefin resin component.

<Hardener (C)> Next, the hardener (C) used in the present invention will be described. The hardener (C) can react with the carboxyl group or the acid anhydride group of the polyolefin resin (A) and the polymer (B) to exhibit sufficient adhesion strength, and can suppress molding even when immersed in the electrolyte solution for a long time The appearance of the part was poor, and the bonding strength was maintained at a high level.

The hardener (C) preferably has at least one or more functional groups selected from the group consisting of isocyanate group, epoxy group, carbodiimide group, and aziridinyl group, and more preferably is selected from isocyanate group and epoxy group. By reacting the functional group with a carboxyl group or an acid anhydride group of the polyolefin resin (A) and the polymer (B), a crosslinked structure having high durability in an electrolyte solution can be obtained.

The curing agent (C) having an isocyanate group is not limited, and a well-known diisocyanate and a compound derived therefrom can be preferably used. For example, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, 1,5-naphthalene diisocyanate, six Diisocyanates such as methylene diisocyanate, bis (4-isocyanate cyclohexyl) methane, or hydrogenated diphenylmethane diisocyanate, and compounds derived from these diisocyanates. Examples of the compound derived from a diisocyanate include an isocyanurate body, an adduct body, a biuret type body, a uretdione body, a urethane body, and an isocyanate residue of the diisocyanate. Prepolymers (oligomers obtained from diisocyanates and polyols), or composites of these. These may be used alone or in combination of two or more of them arbitrarily. Among them, a hardener (C) containing a structure selected from the group consisting of a biuret body, an isocyanurate body, and a urea diketone body is preferred from the viewpoint of excellent durability in an electrolyte solution.

Examples of commercially available products of the hardening agent (C) having an isocyanate group include, for example, Coronate HX, HL, L, 2770 manufactured by Japan Polyurethane Co., Ltd., and Duolion manufactured by Asahi Kasei Chemical Co., Ltd. Duranate 24A-100, TPA-100, P301-75E, TSE-100, MFA-75B, MHG80-B, Takenate D-110N, D-120N, D-127N, D-160N, D-170N, D-165N, D-178N, etc.

The hardening | curing agent (C) which has an epoxy group is not limited, A well-known epoxy compound can be used preferably. Examples include: bisphenol A diglycidyl ether, modified bisphenol A diglycidyl ether, novolac glycidyl ether, glycerol polyglycidyl ether, polyglycerol polyglycidyl ether, N, N-bis (2,3 -Epoxypropyl) aniline, 2-methyl-N, N-bis (2,3-epoxypropyl) aniline, N, N-diglycidylaniline, N, N-diglycidyl 2-methylaniline, N, N, N ', N'-tetra (2,3-epoxypropyl) -1,4-phenylenediamine, N, N, N', N'-tetra ( Epoxy compounds having aromatic amino groups such as oxetan-2-ylmethyl) -4,4'-methylenebisaniline, N, N-diglycidyl-4- (glycidyloxy) aniline , 2,4,6-tris (glycidyloxy) -1,3,5-triazine and other epoxy compounds having a triazine skeleton. These may be used alone or in combination of two or more of them arbitrarily.

Examples of commercially available products having an epoxy-based hardener (C) include jER-828, jER-834, jER-1001, jER-1002, jER-1004, and jER-604 manufactured by Mitsubishi Chemical Corporation. , JER-630, Adeka resin EP-4100, EP-4340, EP-4901, EP-4950, EP-4000, EP-4005, EP- 3950S, EP-3980S, Denacol EX-611, EX614, EX-411, EX-211, R-45EPT manufactured by Nagase ChemteX Co., Ltd., manufactured by Nissan Chemical Co., Ltd. TEPIC-G, TEPIC-S, TEPIC-SP, TEPIC-SS, TEPIC-HP, TEPIC-L, TEPIC-PAS, TEPIC-VL, TETRAD-X, special manufactured by Mitsubishi Gas Chemical Co., Ltd. Tetrad-C and so on.

The hardening agent (C) having a carbodiimide group is not limited, but a known carbodiimide compound can be preferably used. Examples include polycondensates of well-known diisocyanates and derivatives exemplified among hardeners having an isocyanate group. These may be used alone or in combination of two or more of them arbitrarily.

Examples of commercially available products of the carbodiimide-based hardener (C) include Carbodilite V-01, V-03, V-05, and V- manufactured by Nisshinbo Chemical Co., Ltd. 07, V-09 and so on.

The curing agent (C) having an aziridine group is not limited, but a known aziridine compound can be preferably used. Examples include: N, N'-hexamethylene-1,6-bis (1-aziridinecarboxyamidoamine), N, N'-diphenylmethane-4,4'-bis (1-nitrogen Propidylcarboxamide), trimethylolpropane-tri-β-aziridinylpropionate, N, N'-toluene-2,4-bis (1-aziridinecarboxamide), triethylene glycol Melamine, trimethylolpropane-tri-β- (2-methylaziridine) propionate, bisisophthalenyl-1,2-methylaziridine, tris (1-nitrogen) Propididyl) phosphine oxide, tris (2-methyl-1-aziridinyl) phosphine oxide, and the like. These may be used alone or in combination of two or more of them arbitrarily.

As commercially available products of the aziridinyl-based hardener (C), for example, chemitite PZ-33 manufactured by Japan Catalyst Co., Ltd., and Klaus Linco manufactured by Huoya Pharmaceutical Co., Ltd. (CROSSLINKER) CL-427 and so on.

Let the polyolefin resin (A) contained in the adhesive composition be i g (g), the polymer (B) having a carboxyl group or an acid anhydride group be j g (g), and the hardener (C) When the functional group of Z is set to Z millimoles (mmol), Z / (P * i + X * j) (P: the acid value of the polyolefin resin (A), and X: the acid of the polymer (B) (Valence) is in the range of 0.3 to 10 to include the hardener (C), and more preferably in the range of 0.5 to 7. In addition, "*" in this specification indicates a multiplication sign. If it is in the range of 0.3 to 10, the amount of epoxy groups relative to the active hydrogen derived from the carboxyl group in the polyolefin resin (A) is suitable. Therefore, the cohesive force, the bonding strength, and the Excellent durability. In addition, it is difficult to excessively present the unreacted hardener (C), and therefore the durability in the electrolyte solution is also optimized.

The adhesive of this embodiment may further contain a silane coupling agent. Examples of the silane coupling agent include a trialkoxysilane having a vinyl group such as vinyltrimethoxysilane, vinyltriethoxysilane, 3-aminopropyltriethoxysilane, and N- (2- (Aminoethyl) 3-aminopropyltrimethoxysilane, such as trialkoxysilane with amino group, 3-glycidyloxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyl Glycidyl, and the like, such as trimethoxysilyl and triglycidyloxypropyltriethoxysilane. Based on the solid content of the adhesive, the addition amount of the silane coupling agent is preferably from 0.1% by mass to 5% by mass, and more preferably from 0.5% by mass to 3% by mass. Thereby, the adhesive strength with a metal foil can be improved.

The adhesive of the present embodiment may further contain phosphorus oxyacid or a derivative thereof. Among the phosphorus oxyacids or derivatives thereof, the phosphorus oxyacid need only have at least one free oxyacid, and examples thereof include phosphorous acid such as hypophosphorous acid, phosphorous acid, orthophosphoric acid, and hypophosphorous acid. Condensed phosphoric acids such as metaphosphoric acid, pyrophosphoric acid, tripolyphosphoric acid, polyphosphoric acid, and superphosphoric acid. Examples of the derivative of phosphorus oxo acid include compounds obtained by partially esterifying the phosphorus oxo acid with alcohols in a state where at least one free oxo acid remains. Examples of these alcohols include aliphatic alcohols such as methanol, ethanol, ethylene glycol, and glycerol, and aromatic alcohols such as phenol, xylenol, hydroquinone, catechol, and resorcinol. The phosphorus oxo acid or its derivative may be used in combination of two or more kinds. Based on the solid content of the adhesive, the addition amount of phosphorus oxo acid or its derivative is preferably 0.01% by mass to 10% by mass, more preferably 0.05% by mass to 5% by mass, and particularly preferably 0.1% by mass to 1%. quality%. Thereby, the adhesive strength after electrolyte solution immersion can be improved.

The adhesive of the present invention may further contain an epoxy phosphate resin. The epoxy phosphate resin is a resin in which an epoxy group of an epoxy resin reacts with phosphoric acid, the epoxy group is ring-opened, and an epoxy resin portion and a phosphoric acid portion are bonded by using a phosphate ester bond. Thereby, the adhesive strength after electrolyte solution immersion can be improved.

Preferred epoxy phosphate resins are compounds represented by the following general formula (1) and general formula (2).

Formula (1)

Formula (2)

Examples of the epoxy resin that reacts with phosphoric acid include bisphenol A epoxy resin, bisphenol F epoxy resin, phenol novolac epoxy resin, bisphenol AD epoxy resin, and biphenyl epoxy resin. Resins, naphthalene-type epoxy resins, alicyclic epoxy resins, glycidyl ester epoxy resins, glycidylamine epoxy resins, heterocyclic epoxy resins, diarylfluorene epoxy resins, terephthalene Phenol-type epoxy resin and modified products thereof.

As the epoxy phosphate resin, a commercially available product can also be used. Specifically, it is preferably URAD-DD79 (manufactured by DSM, Japan). Furthermore, it is also preferable that it is an epoxy phosphate resin which has a characteristic value equivalent to the said Urad-DD79.

The adhesive of this embodiment may contain catechol or its derivative. Specific examples include catechol, tert-butylcatechol, adrenaline, noradrenaline, dopamine, nordihydroguaiaretic acid, and the like. Thereby, the adhesive strength with a metal foil can be improved.

The adhesive composition of this embodiment may contain an organic solvent. The organic solvent is not particularly limited, and it is preferred that the material used in the present adhesive composition can be dissolved in the form of a single solvent or a mixed solvent, the reactivity with the curing agent (C) is inactive, and it can be applied by the adhesive. The overheating of the drying step evaporates and is removed. Specific examples of these solvents include aromatic organic solvents such as toluene and xylene; aliphatic organic solvents such as n-hexane and n-heptane; and alicyclic organic solvents such as cyclohexane and methylcyclohexane. Solvents; ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone; ester solvents such as ethyl acetate, butyl acetate; ethanol, methanol, n-propanol, 2-propanol, butanol Alcohol solvents such as hexanol; ether solvents such as diisopropyl ether, butyl cellosolve, tetrahydrofuran, dioxane, butylcarbitol; diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, propylene glycol Glycol ether solvents such as monomethyl ether; Glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, and other glycol ester solvents. These solvents can be used alone , Or more than two kinds can be used together. Among these solvents, in terms of storage stability of the solution of the polyolefin resin (A), an aromatic organic solvent and a ketone solvent are used in combination, an aromatic organic solvent and an alcohol solvent are used in combination, and an alicyclic system is preferable. An organic solvent is used in combination with a ketone solvent, and an alicyclic organic solvent is used in combination with an alcohol solvent.

In the adhesive composition of this embodiment, well-known additives, such as a tackifier and a plasticizer, can be mix | blended as needed within the range which does not impair the effect of invention. Examples of the adhesion-imparting agent usable in this embodiment include polyterpene resins, rosin resins, aliphatic petroleum resins, alicyclic petroleum resins, copolymer petroleum resins, styrene resins, and hydrogenated petroleum resins. A resin or the like is used for the purpose of improving adhesion strength. These adhesion-imparting agents may be used alone, or two or more of them may be used in any combination. Examples of the plasticizer used in this embodiment include liquid rubbers such as polyisoprene and polybutene, and process oils.

The adhesive composition of this embodiment is suitable for lamination of a metal foil (13) and a heat-welding resin film (15).

<Metal foil> Examples of the metal of the metal foil (13) include aluminum, copper, nickel, steel, and stainless steel (SUS). These metal foils may be metal foils subjected to various surface treatments. Examples of the surface treatment include physical treatments such as sand blasting and grinding, or surface treatments such as degreasing treatment by vapor deposition, etching treatment, and primer treatment using a coupling agent or a coating agent. The treatment agent for forming the surface treatment layer preferably contains a functional group that reacts with a functional group in the hardener (C), and more preferably contains at least one selected from the group consisting of a carboxylic acid group, a hydroxyl group, and an amino group. Functional groups are preferred. The amino group referred to here is a primary amine, a secondary amine, and an imino group. By providing a surface treatment layer containing such a functional group on the surface of the metal foil (13), when the adhesive composition is thermally hardened, the epoxy group in the adhesive layer reacts with the functional group in the surface treatment layer, This is preferable because a laminate having a high initial bonding strength and excellent electrolyte solution resistance can be obtained.

<Thermal fusion resin film> The thermal fusion resin film (15) is not particularly limited, but is preferably a polyolefin-based film, and preferably contains an acid-modified product selected from the group consisting of polyethylene, polypropylene, and olefin-based copolymers, and An unstretched film of at least one thermoplastic resin in the group of ionic polymers. The thickness of the heat-welded resin film is not particularly limited, but it is preferably 20 μm to 150 μm.

The laminated body formed using the adhesive composition of this embodiment can be obtained as follows, for example. The adhesive composition of this embodiment is applied to one side of a metal foil (13) (or a heat-welded resin film (15)), and the solvent is evaporated (dried) to form an unhardened adhesive layer, at 60 ° C to After heat-sealing a resin film (or metal foil) on the surface of the uncured adhesive layer under pressure at 150 ° C, the adhesive layer was left to stand at 40 ° C to 80 ° C for about 1 to 10 days. It is hardened (also called aging), and a metal foil and a heat-sealing resin film are bonded together to obtain a laminate. The adhesive composition can be applied using a general coater such as a comma coater. The thickness (amount) of the hardening adhesive layer at the time of dry hardening is preferably about 0.5 g / m ² to 10 g / m ² .

The packaging material for a storage battery element according to this embodiment may be separated on the other surface of the metal foil (13) (the surface that is not in contact with the inner-layer-side adhesive layer (14) formed by the adhesive composition of this embodiment). An outer layer side resin film (11) is formed on the outer layer side adhesive layer (12). The outer-layer-side resin film (11) may be laminated on the metal foil (13) using an adhesive composition (which may be the same as or different from the adhesive composition of the present embodiment), or the adhesive of the present embodiment may be used. The composition is used to obtain a laminate of a metal foil (13) and a heat-welded resin film (15), and then an outer layer-side resin film (11) is laminated on the metal foil (13) with an outer-layer-side adhesive layer (12) interposed therebetween. Examples of the outer-layer-side resin film (11) to be used include stretch films such as polyester resins and polyamide resins (nylon). The outer-layer-side resin film layer (11) is formed on the outer side that does not come into contact with the electrolyte solution when a container for a power storage element is formed using the laminate as a packaging material for a power storage element.

The container for a storage battery element of this embodiment can be obtained by using the packaging material for a storage battery element described above, the outer resin film layer (11) forming a convex surface, and the heat-welded resin film (15) forming a concave surface. In addition, the "concave surface" in the present specification refers to a recessed surface that can store an electrolyte solution in a case where a flat battery packaging material is formed into a tray shape as shown in FIG. 2. The surface, the "convex surface" as used in this specification, refers to the back surface (surface on the opposite side and surface on the back side) of the surface having the depression.

A power storage element such as a secondary battery includes a battery body, a plurality of terminals each joined to a positive electrode and a negative electrode of the battery body, a battery container, and an electrolyte solution. The battery container is a laminate obtained by laminating a metal foil (13) and a heat-sealing resin film (15) through an adhesive layer (14) formed of the adhesive composition of the present invention, and the heat-sealing is performed. A resin film is in contact with the electrolyte solution.

The electrolyte solution starts to penetrate from the heat-welded resin film (15) to the metal foil (13). However, the adhesive layer (14) formed from the adhesive composition of the present invention has excellent resistance to the electrolyte solution, so the heat-welded resin film The adhesion strength to the metal foil will not decrease, and problems such as liquid leakage will not occur. [Example]

Hereinafter, the present invention will be described in more detail through examples, but the following examples do not limit the scope of rights of the present invention at all. In addition, each evaluation in an Example is based on the following method. In the examples,% represents mass%, and parts represent mass parts. <Quantification of acid value> The weighed sample a (g) was dissolved in refluxing xylene and cooled to room temperature. Titration was performed using phenolphthalein as an indicator using 0.1 M ethanolic potassium hydroxide. This is quantified. The point at which the coloration of the indicator remained for 10 seconds was taken as the end point of the titration. When the titer is set to b (mL), the acid value can be obtained from the following formula. Acid value = 0.1 * b / a

<Weight average molecular weight> The HLC-8220GPC system manufactured by Tosoh Co., Ltd., obtained by connecting two TSKgel superHZM-N columns to each other, uses tetrahydrofuran as the eluent and sets the column temperature to 40 ° C. The measurement was performed at a flow rate of 0.35 mL per minute. The sample was adjusted by dissolving 2 mg of polyolefin resin (A) in 5 mL of tetrahydrofuran. The weight average molecular weight is calculated in terms of standard polystyrene.

<Melting point and melting energy (ΔE)> The melting point and ΔE can be determined by DSC measurement in accordance with JIS K7121. The specific measurement method is as described above.

<Copolymerization composition ratio> The copolymerization composition ratio of polyolefin was determined by ¹³ C measurement using Nuclear Magnetic Resonance (NMR) (JNM-LA400) manufactured by Japan Electronics Co., Ltd. A 20 mg sample was dissolved in 1 mL of deuterated chloroform for determination. 25 to 30 ppm contains methine derived from propylene, and 30 to 35 ppm contains methine derived from 1-butene. The copolymerization composition ratio was obtained from the integration ratio of each peak.

<Preparation of Polyolefin Resin (A)> <Manufacturing Example 1> As a polyolefin polymerization reaction, 250 mL of purified toluene was put into a glass autoclave with an inner volume of 500 mL substituted with nitrogen, and 0.5 mg was converted into Al atom. Methyl aluminoxane, 1.25 μg atom of dimethylsilyl dichloride-bis- (4,5,6,7,8-pentahydrofluoren-2-yl) zirconium in terms of Zr atom, temperature rise To 20 ° C. Then, while supplying propylene at a constant rate of 100 L / hr, and continuously supplying 1-butene monomer at a constant pressure of 1.32 MPa at 20 ° C, polymerization was started. After polymerization was performed at 20 ° C for 8 hours, isopropyl alcohol was added to stop the polymerization. The obtained polymer solution was added to a large amount of methanol to precipitate a polymer. The precipitated polymer was filtered and dried to obtain a polyolefin copolymerized by propylene / 1-butene = 72/28 (molar ratio). As a monomer graft reaction with a polyolefin, 380 g of the obtained polyolefin, 600 g of toluene, and 16 g of maleic anhydride as a graft monomer were charged into a glass reaction container having an internal volume of 2 L, and the mixture was charged with nitrogen. The solution was heated and dissolved under a stream, and the temperature of the solution was set to 100 ° C. After stirring for 1 hour, 4 g of t-butyl peroxide (2-ethylhexanoate) was added, and the reaction was continued at the temperature for 4 hours. The polymer solution thus obtained was added to a large amount of methanol while stirring, to precipitate a polymer. The precipitated polymer was filtered, washed with methanol several times, and dried to obtain a polyolefin resin (A1). Regarding the obtained polyolefin resin (A1), it was confirmed by GPC measurement that components other than the polyolefin resin (A1) were removable. The Mw, acid value P, melting point, and ΔE of the polyolefin resin (A1) were 186000, 0.018 mmol / g, 76 ° C, and 30 mJ / mg, respectively.

<Manufacturing Example 2> During the polymerization of polyolefin, propylene was supplied at a flow rate of 20 L / hr, and 0.4 mg of methylaluminoxane in terms of Al atom and 1 μg of dichloride in terms of Zr atom were used. When dimethylsilyl-bis- (4,5,6,7,8-pentahydrofluoren-2-yl) zirconium is used for graft reaction with a monomer of polyolefin, 388 g of polyolefin is used as the graft Except for 10 g of maleic anhydride and 2 g of t-butyl peroxide (2-ethylhexanoate) as a radical initiator, propylene / 1-butyl was obtained by the same method as in Production Example 1. Polyolefin resin (A2) obtained by copolymerizing olefin = 19/81 (molar ratio). The Mw, acid value P, melting point, and ΔE of the polyolefin resin (A2) were 290,000, 0.06 mmol / g, 58 ° C, and 27 mJ / mg, respectively.

<Manufacturing Example 3> During the polymerization of polyolefin, propylene was supplied at a flow rate of 150 L / hr. During the graft reaction with the monomer of the polyolefin, 379 g of polyolefin and 15 g of maleic anhydride as the graft monomer were used. Except for 4 g of lauryl methacrylate and 2 g of t-butyl peroxide (2-ethylhexanoate) as a radical initiator, propylene / 1-butyl was obtained by the same method as in Production Example 1. Polyolefin resin (A3) obtained by copolymerizing olefin = 86/14 (molar ratio). The Mw, acid value P, melting point, and ΔE of the polyolefin resin (A3) were 194000, 0.12 mmol / g, 92 ° C, and 28 mJ / mg, respectively.

<Manufacturing Example 4> During the polymerization of polyolefin, propylene was supplied at a flow rate of 85 L / hr. During the grafting reaction with the monomer of the polyolefin, 350 g of polyolefin and 40 g of maleic anhydride as the graft monomer were used. Except for 10 g of t-butyl peroxide (2-ethylhexanoate) as a free radical initiator, propylene / 1-butene = 67/33 (mole) was obtained by the same method as in Production Example 1. Ratio) copolymerized polyolefin resin (A4). The Mw, acid value P, melting point, and ΔE of the polyolefin resin (A4) were 165,000, 0.3 mmol / g, 74 ° C, and 28 mJ / mg, respectively.

<Manufacturing Example 5> At the time of polyolefin polymerization, a methylaluminoxane of 1.5 mg in terms of Al atom and 3.5 μg of atom in terms of Zr atom were used as a dimethylsilyl dichloride-bis- ( 4,5,6,7,8-pentahydrofluoren-2-yl) zirconium, when grafting with a monomer of a polyolefin, 380 g of polyolefin, 18 g of maleic anhydride as a graft monomer, Except for 2 g of t-butyl peroxide (2-ethylhexanoate) as a radical initiator, propylene / 1-butene = 73/27 (molar ratio) was obtained by the same method as in Production Example 1. ) Copolymerized polyolefin resin (A5). The Mw, acid value P, melting point, and ΔE of the polyolefin resin (A5) were 60,000, 0.12 mmol / g, 76 ° C, and 26 mJ / mg, respectively.

<Manufacturing Example 6> At the time of polyolefin polymerization, methyl aluminoxane, which is 0.25 mg in terms of Al atom, and 0.5 μg of atom in terms of Zr atom, dimethylsilyl dichloride-bis- ( 4,5,6,7,8-pentahydrofluoren-2-yl) zirconium, when grafting with a monomer of a polyolefin, 380 g of polyolefin, 18 g of maleic anhydride as a graft monomer, Except for 2 g of t-butyl peroxide (2-ethylhexanoate) as a radical initiator, propylene / 1-butene = 72/28 (molar ratio) was obtained by the same method as in Production Example 1. ) Copolymerized polyolefin resin (A6). The Mw, acid value P, melting point, and ΔE of the polyolefin resin (A6) were 376000, 0.11 mmol / g, 77 ° C, and 26 mJ / mg, respectively.

<Manufacturing example 7> (comparative) Kuraprene LIR-403 (maleated polyisoprene) manufactured by Kuraray Co., Ltd. was used as the polyolefin resin (A7). The polyolefin resin (A7) has Mw and acid value P of 45,000 and 0.1 mmol / g, respectively, and does not have a melting point.

<Preparation of polymer (B)> <Manufacturing Example 8> As the polymer (B1), SMA2625 (semi-esterified product of styrene / maleic anhydride copolymer) manufactured by Cray Valley was used. Mw and acid value X of the polymer (B1) were 9000 and 3.9 mmol / g, respectively.

<Manufacturing Example 9> As the polymer (B2), Daiyakaruna 30 (maleic anhydride / α-olefin copolymer having 20 to 28 carbon chains) manufactured by Mitsubishi Chemical Corporation was used. The polymer (B2) had Mw and acid value X of 9,000 and 1.3 mmol / g, respectively.

<Manufacturing example 10> As polymer (B3), Joncryl 68 (styrene / acrylic copolymer) manufactured by BASF was used. The polymer (B3) had Mw and acid value X of 10,000 and 3.5 mmol / g, respectively.

<Manufacturing Example 11> As the polymer (B4), Pripol 1009 (a hydrogenated dimer acid of an unsaturated fatty acid) manufactured by Croda was used. The polymer (B4) had Mw and acid value X of 900 and 2.4 mmol / g, respectively.

<Manufacturing Example 12> As the polymer (B5), isobam 600 (maleic anhydride / isobutylene copolymer) manufactured by Kuraray Corporation was used. The polymer (B5) had Mw and acid value X of 7000 and 14.1 mmol / g, respectively.

<Manufacturing Example 13> As the polymer (B6), Ricon 130MA20 (maleic acid graft-modified polybutadiene) manufactured by Cray Valley was used. Mw and acid value X of the polymer (B6) were 6500 and 2.1 mmol / g, respectively.

<Manufacturing Example 14> As the polymer (B7), SMA3940 (a half-ester of a styrene / maleic anhydride copolymer) manufactured by Cray Valley was used. The polymer (B7) had Mw and acid value X of 11,000 and 1.9 mmol / g, respectively.

<Manufacturing Example 15> A 1 L four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen introduction tube was charged with 160 g of methyl ethyl ketone and 38.9 g of maleic anhydride, and a 90 ° C water bath was used while introducing nitrogen gas. Heat and stir. While maintaining the reflux state, 1.1 g of tert-butyl peroxytrimethylacetate was added, and the mixture was reacted by heating and stirring for 4 hours. The solvent and unreacted maleic anhydride were distilled off from the solution obtained in the above manner using an evaporator, and then sufficiently dried to obtain a maleic acid polymer. The polymer obtained in this manner was referred to as a polymer (B8). Mw and acid value X of the polymer (B8) were 250 and 16.9 mmol / g, respectively.

<Manufacturing Example 16> A 1 L four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, and a nitrogen introduction tube was charged with 150 g of methyl ethyl ketone, and heated at 90 ° C using a water bath while introducing nitrogen gas. While maintaining the reflux state, it took 2 hours using a dropping funnel to dropwise add 15 g of methacrylic acid, 40 g of lauryl methacrylate, 45 g of methyl methacrylate, and tert-butyl permethoxide. A solution in which 1.5 g of the ester was uniformly mixed was reacted. After completion of the dropwise addition, heating and stirring were continued for 2 hours, and then 0.15 g of tert-butyl peroxytrimethylacetate was added, followed by heating and stirring for 3 hours. The resin solution obtained in this manner was concentrated and dried using an evaporator, thereby obtaining a polymer (B9). The polymer (B9) had Mw and acid value X of 9,000 and 17.0 mmol / g, respectively.

<Preparation of Base Agent> The total amount of the polymer (B) in the glass container was 100% by weight based on the total weight of the polymer (B) and the polyolefin resin (A) and the polymer (B). 20 g of the polyolefin resin (A) and the polymer (B) were dissolved in 80 g of a mixed solvent of methylcyclohexane / methyl ethyl ketone = 7/3 (weight ratio) to prepare a solid component. A 20% strength resin solution was used as the base solution.

<Preparation of hardener> <Preparation example 1 of hardener> In a glass container, Duranate TPA-100 (trimer of hexamethylene diisocyanate, isocyanate-based The amount of functional groups was 5.2 mmol / g), 50 g, and 50 g of ethyl acetate were dissolved to obtain a solution having a solid content concentration of 50%. Let this be a hardener (C1).

<Preparation Example 2 for hardener> 50 g of jER-604 (a tetraglycidyl diaminodiphenylmethane and an epoxy functional group content of 10.0 mmol / g) manufactured by Mitsubishi Chemical Corporation was placed in a glass container. 50 g of ethyl acetate were dissolved, and a solution having a solid content concentration of 50% was obtained. Let this be a hardener (C2).

<Preparation example 3 of hardener> In a glass container, Carbodilite V-05 (1,3-bis (2-isocyanato-2-propyl) benzene manufactured by Nisshinbo Chemical Co., Ltd. was added. 50 g of the condensation reaction product, the functional group of the carbodiimide group, and the functional group of the isocyanate group (1.9 mmol / g) were dissolved in 50 g to obtain a solid content concentration of 50%. Solution. Let this be a hardener (C3).

<Preparation example 4 of hardener> A glass container was charged with chemitite PZ-33 (tris (1-aziridinepropionic acid) 1,1,1-propanetriyl) manufactured by Japan Catalyst Co., Ltd. The amount of functional groups of trimethylene and aziridinyl was 6.3 mmol / g), 50 g and 50 g of ethyl acetate were dissolved, and a solution having a solid content concentration of 50% was obtained. Let this be a hardener (C4).

<Production of Metal Foil><Production Example 1 of Treated Aluminum> 3.8 parts of a polycarboxylic acid resin (Acryset, EMN-260E, manufactured by Japan Catalyst Co., Ltd.), 2 parts of orthophosphoric acid, and 4 parts of chromium (III) fluoride was dissolved in 990 parts of distilled water, and 0.2 part of the oxazoline group-containing polymer (Epocros WS-700, manufactured by Japan Catalyst Co., Ltd.) was dissolved. Thus, a treatment agent 1 having a solid content concentration of 1% was prepared. On one side of the aluminum foil (40 μm) subjected to degreasing treatment, the treatment liquid 1 was applied so that the dry coating amount became 50 mg / m ² , and dried at 150 ° C., thereby obtaining a surface treatment layer having a source originating in the surface treatment layer. AL-1 of carboxyl group of polycarboxylic resin.

<Preparation Example 2 of Treated Aluminum> 1 part of an aminated phenol polymer, 0.5 part of chromium (III) fluoride, and 2 parts of phosphoric acid were dissolved in 346.5 parts of distilled water to prepare a treatment having a solid content concentration of 1%剂 2。 Agent 2. In an aluminum foil degreasing treatment (40 μm) on one side of a dry coating amount became 50 mg / m ² of the embodiment 2 liquid coating process, dried at 150 deg.] C, thereby obtaining a treatment layer from a surface Aminoated hydroxyl group of phenol polymer AL-2.

<Production Example 3 of Treated Aluminum> 9.1 parts of cerium oxide, 0.9 parts of sodium phosphate, and 90 parts of distilled water were mixed to obtain a cerium oxide sol (treatment agent 3) having a solid content concentration of 10%. On one side of the aluminum foil (40 μm) subjected to the degreasing treatment, the treatment liquid 3 was applied so that the dry coating amount became 80 mg / m ² , and dried at 200 ° C., thereby obtaining a surface treatment layer having an origin derived from The hydroxyl group of phosphoric acid is AL-3.

<Production Example 4 of Treated Aluminum> 4.5 parts of polyethyleneimine, 0.5 parts of an acrylic-isopropenyloxazoline copolymer, and 95 parts of distilled water were mixed to prepare a treatment agent 4 having a solid content concentration of 5%. The treatment liquid 4 was further applied on the surface treatment level of the aluminum AL-3 so that the dry coating amount became 25 mg / m ² , and dried at 200 ° C., thereby obtaining a polyethylene oxide derived from polyethylene in the surface treatment layer. Amine amino AL-4.

<Example 1 to Example 23, Comparative Example 1 to Comparative Example 4> Various main agent solutions and hardener solutions were prepared so as to have values of Z / (P * i + Z * j) shown in Table 2, Then, it was diluted with a mixed solvent of methylcyclohexane / methyl ethyl ketone = 7/3 (weight ratio), and adjusted to a solid content concentration of 15% to prepare an adhesive composition. However, since Example 23 had a solid content concentration of 15% and a high viscosity, it was adjusted to 10% solid content to prepare an adhesive composition. A laminate of the metal foil and the unstretched polypropylene film described in Table 2 was produced according to the method described below, and the presence or absence of changes in the initial adhesion strength, the adhesion strength after the electrolyte solution impregnation, and the appearance of the molded part after the electrolyte solution impregnation were evaluated.

[Table 1]

[Table 2]

The symbols in Tables 1 and 2 are as follows. LMA: lauryl methacrylate MMA: methyl methacrylate MAA: methacrylic acid

<Performance test> (Production of nylon / treated aluminum laminate film) A urethane-based dry laminating adhesive was applied to the non-treated surface of treated aluminum so that the dry coating amount became 4 g / m ² (Toyo "AD502 / CAT10" manufactured by Toyo Morton Co., Ltd.) was dried at 100 ° C for 1 minute, and then a biaxially stretched nylon film having a thickness of 25 μm was bonded. Then, the obtained laminated body was hardened (aged) at 60 ° C. for 7 days to sufficiently harden the adhesive. Hereinafter, the nylon / treated aluminum laminate film obtained in the manner described is referred to as "ONY / AL laminate film".

(Production of nylon / treated aluminum / unstretched polypropylene laminated film) Each of the examples and comparative examples was applied to the aluminum treated surface of the ONY / AL laminated film so that the dry coating amount became 2 g / m ² . After drying at 100 ° C for 1 minute, an unstretched polypropylene film (CPP) having a thickness of 30 μm was bonded. Then, the obtained laminate was aged at 40 ° C. for 7 days to sufficiently harden the adhesive. Hereinafter, the nylon / treated aluminum / CPP laminated film obtained in the above-mentioned manner is referred to as “ONY / AL / CPP laminated film”.

(Production of treated aluminum / unstretched polypropylene laminate film) Each adhesive was applied to the treated surface of treated aluminum such that the dry coating amount became 2 g / m ² , and dried at 100 ° C for 1 minute, and then applied. CPP with a combined thickness of 30 μm. Then, the obtained laminate was aged at 40 ° C. for 7 days to sufficiently harden the adhesive. The processed aluminum / CPP laminated film obtained in the above-mentioned manner is hereinafter referred to as "AL / CPP laminated film".

[Initial bonding strength (before electrolyte solution impregnation)] After the AL / CPP laminated film was left to stand in an environment of 25 ° C and 65% humidity for 6 hours, it was cut to a size of 200 mm × 15 mm, according to ASTM- The test method of D1876-61 uses a tensile tester to perform a T-type peel test at a load speed of 100 mm / min in an environment of 25 ° C and 65% humidity. The average value of 5 test pieces was used to show the peel strength (N / 15 mm width) between aluminum foil and CPP. The results were judged according to the following criteria. ◎: Excellent for practical use: 7 N or more ○: Practical range: 5 N or more and less than 7 N ×: Not practical: less than 5 N

[Adhesive strength after electrolyte solution impregnation] The same test piece used in the initial adhesion strength test was subjected to an electrolyte solution at 85 ° C [dissolving lithium hexafluorophosphate in ethylene carbonate / diethyl carbonate / dimethyl carbonate = 1 / 1/1 (volume ratio), made of 1 mol / l lithium hexafluorophosphate solution] immersed in 7 days. Then, the test piece was taken out and washed with running water for about 10 minutes. After the water was sufficiently wiped off with a paper wiper, the adhesion strength of the test piece was measured in the same manner as the adhesion strength before the immersion test. The measurement results were judged according to the following criteria. ◎: Excellent for practical use: 7 N or more ○: Practical range: 5 N or more and less than 7 N ×: Not practical: less than 5 N

[Are there any changes in the appearance of the molded part after the electrolyte solution is impregnated?] The ONY / AL / CPP laminated film was formed into a blank shape of 110 mm × 180 mm, and a straight mold was used (the long side of the punch shape was 60 mm, short The sides are 45 mm, the corners are R = 1 mm to 2 mm, the punch shoulder is R = 1 mm, and the die shoulder is R = 0.5 mm. Next, the formed laminated film was dissolved in an electrolyte solution at 85 ° C [dissolving lithium hexafluorophosphate in ethylene carbonate / diethyl carbonate / dimethyl carbonate = 1/1/1 (volume ratio) to make 1 mol / l Of lithium hexafluorophosphate solution] for 7 days. Then, the formed laminated film was taken out, washed with running water for about 10 minutes, and the water was sufficiently wiped off with a paper handkerchief, and then the presence or absence of a change in the appearance of the AL / CPP surface of the formed portion was visually evaluated. The results were judged according to the following criteria. ◎: Excellent in practical use: No floating, whitening ○: Practical range: No floating, but with whitening ×: Not practical: Available with floating

[table 3]

As shown in Table 3, Comparative Example 1 did not contain the polymer (B) having a carboxyl group or an acid anhydride group, so the degree of crosslinking of the adhesive was insufficient, and floating of the molded portion occurred during long-term electrolyte solution immersion.

In Comparative Example 2, since the polymer (B) was contained more than 5% by weight based on 100% by weight of the sum of the polyolefin resin (A) and the polymer (B), the adhesive film became too hard and was immersed in the electrolyte solution. In some cases, the bonding strength and the appearance of the formed portion were poor.

In Comparative Example 3, since the melting point of the polyolefin resin (A) was not in the range of 55 ° C to 100 ° C, the cohesive force of the adhesive was insufficient, and sufficient initial bonding strength could not be obtained.

Comparative Example 4 did not contain a hardening agent (C), and therefore did not form a crosslinked structure with the polyolefin resin (A) or polymer (B). The cohesive force of the adhesive was insufficient, and sufficient initial bonding strength could not be obtained.

On the other hand, in Examples 1 to 23 shown in Table 3, as the polyolefin resin (A), a preferable weight average molecular weight is 40,000 to 400,000, a melting point is 55 ° C to 100 ° C, and it has The carboxyl or acid anhydride-based polyolefin resin contains, as a hardener (C), a preferable amount of a resin having at least one functional group selected from the group consisting of an isocyanate group, an epoxy group, a carbodiimide group, and an aziridinyl group. The hardening agent contains, as the polymer (B), a polymer having a weight average molecular weight of 200 to 130,000 and having a carboxyl group or an acid anhydride group. Therefore, the curing agent satisfies the initial bonding strength, the bonding strength after impregnation with the electrolyte solution, and the like. The appearance of the molded part after the electrolyte solution was immersed changed.

Among them, the adhesives of Examples 13 to 20 showed excellent performance in all tests. In the adhesives of Examples 13 to 20, the acid value P of the polyolefin resin (A) is in a preferred range of 0.02 to 1.2. Therefore, compared with Examples 1 to 3 outside the preferred range, the long-term electrolyte solution impregnation is performed. The subsequent bonding strength and the appearance of the molded portion are excellent. In the adhesives of Examples 13 to 20, the polyolefin resin (A) was a binary copolymer of propylene and 1-butene, and the copolymerization ratio was propylene: 1-butene = 40: 60 to 80: The preferred range of 20 is superior to that of Examples 4 to 7 outside the preferred range, and the initial bonding strength is excellent. In addition, the adhesives of Examples 13 to 20 are preferably 0.5% to 4% by weight based on 100% by weight of the polyolefin resin (A) and the polymer (B) having a carboxyl group or an acid anhydride group. Since the polymer (B) having a carboxyl group or an acid anhydride group is blended in the range, compared with Example 8 outside the preferred range, the adhesion strength after the electrolyte solution is impregnated and the appearance of the molded portion are excellent. In addition, among the adhesives of Examples 13 to 20, Z / (P * i + X * j) is in a preferred range of 0.5 to 7, and therefore, compared with Examples 9 to 11 which are outside the preferred range, the initial stage is Both the adhesion strength and the adhesion strength after the electrolyte solution was immersed were excellent. In addition, in the adhesives of Examples 13 to 20, a curing agent having an isocyanate group or an epoxy group was used as a curing agent. Therefore, the electrolyte solution was impregnated with the electrolyte solution compared to Example 12 using a curing agent having an aziridine group. The subsequent bonding strength and the appearance of the molded portion are excellent. In the adhesives of Examples 13 to 20, the polymer (B) having a carboxyl group or an acid anhydride group is a homopolymer (b-1) of an unsaturated carboxylic acid or an anhydride thereof, or an unsaturated carboxylic acid or an The acid anhydride and the polymer (b-2) of at least one selected from the group consisting of an aromatic ethylene compound, an aliphatic α-olefin compound, and a conjugated diene compound. Compared with Example 21 of the polymer (B) to be polymerized, the adhesive strength after the electrolyte solution was impregnated was superior to the appearance of the molded portion.

[Industrial Applicability] The adhesive composition of the present invention is preferably used as a packaging material (laminate) for forming a container for a lithium ion battery, an electric double-layer capacitor, or a storage element such as a lithium ion capacitor. In addition to this, the adhesive composition of the present invention can be preferably used to form a packaging material for a container of an electric storage device, and can also be used to form construction, chemical, medical, automotive, and the like that require high adhesion strength and chemical resistance. Laminates in various industrial fields.

11‧‧‧ Outer side resin film

12‧‧‧ Outer side adhesive layer

13‧‧‧ metal foil

14‧‧‧Adhesive layer on the inner side

15‧‧‧Heat fusion resin film

FIG. 1 is a schematic cross-sectional view of an embodiment of a packaging material for a storage battery element according to an embodiment. FIG. 2 is a schematic perspective view of an embodiment (tray-shaped) of a container for an electricity storage element according to the embodiment.

Claims (12)

An adhesive composition containing a polyolefin resin component and a hardener C. The polyolefin resin component includes: a polyolefin resin A having a carboxyl group or an acid anhydride group, a melting point of 55 ° C to 100 ° C, and a weight average molecular weight of 40,000 to 400,000; and polymer B, having a carboxyl group or an acid anhydride group, having a weight average molecular weight of 200 to 13,000; and content of the polymer B with respect to the polyolefin resin A and the polymer B and 100% by weight of the polymer B is 0.2% by weight to 5.0% by weight, the hardener C has at least one functional group selected from the group consisting of an isocyanate group, an epoxy group, a carbodiimide group, and an aziridinyl group. The adhesive composition according to item 1 of the patent application range, wherein the acid value X of the polymer B is 1.2 to 20 mmol / g. The adhesive composition according to item 1 or item 2 of the patent application range, wherein the polyolefin resin A has an acid value P of 0.02 to 1.2 mmol / g. The adhesive composition according to item 1 or item 2 of the scope of patent application, wherein the polyolefin resin A is set to i g, the polymer B is set to j g, and the hardener's When the functional group is set to Z mmol, Z / (P * i + X * j) is 0.3 to 10. The adhesive composition according to item 1 or item 2 of the patent application scope, wherein the polymer B is a homopolymer b-1 of an unsaturated carboxylic acid or an anhydride thereof, or an unsaturated carboxylic acid or an anhydride thereof, A polymer b-2 with at least one selected from the group consisting of an aromatic ethylene compound, an aliphatic α-olefin compound, and a conjugated diene compound. The adhesive composition according to item 1 or item 2 of the scope of patent application, wherein the melting point of the polyolefin resin A is 65 ° C to 90 ° C, and the weight average molecular weight is 100,000 to 300,000. A laminated body having an adhesive layer between a metal foil and a heat-welded resin film layer, the adhesive layer comprising the adhesive composition according to any one of claims 1 to 6 of a patent application range form. The laminated body according to item 7 of the scope of patent application, which has a surface treatment layer between the metal foil and the adhesive layer, and the surface treatment layer reacts with a functional group having a hardener C A functional group treating agent is formed. According to the laminated body described in claim 8, the functional group of the treatment agent that reacts with the functional group of the hardener C is at least one selected from the group consisting of a carboxyl group, a hydroxyl group, and an amino group. A packaging material for a power storage element requires an outer layer side resin film, an outer layer side adhesive layer, a metal foil, an inner layer side adhesive layer, and a thermal fusion resin film in this order from the outside. The inner layer side adhesive layer is made of, for example, Formation of the adhesive composition as described in any one of claims 1 to 6 in the scope of patent application. A container for a power storage element is formed from the packaging material for a power storage element according to item 10 of the scope of application for a patent, and a heat-welded resin film forms an inner surface. A power storage element using the container for a power storage element according to item 11 of the scope of patent application.