JP2013112697A - Adhesive composition, laminate using the same, and secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly productive adhesive composition that expresses a high adhesive strength in a short aging period in adhesion of a heat sealing film with a metal foil, has a long pot life, and can form a laminate capable of retaining a high level of the adhesive strength even when soaked in an electrolyte solution for a long period.SOLUTION: The adhesive composition includes 20-90 wt.% carboxyl group-containing amorphous polyolefin resin (A1) and 10-80 wt.% tackifier (B) in total 100 wt.% of the amorphous polyolefin resin (A) containing polyolefin resin (A1) having a carboxyl group and the tackifier (B), wherein an amount of the carboxyl group deriving from the carboxyl group-containing amorphous polyolefin resin (A1) contained in the total 1 g of the amorphous polyolefin resin (A) and the tackifier (B) is 0.001-0.675 (mmol), and the adhesive composition further contains an aziridine group-containing compound (C) in a range that the amount of the aziridine group is 0.3-10 mol with respect to the total 1 mol of the carboxyl group and 0.5 mol or more tertiary amine (D) with a boiling point at 70-300 °C.

Description

The present invention relates to a laminate suitable for forming a battery container for a secondary battery. Specifically, the present invention relates to a laminate that has high adhesive strength in the adhesion between a heat-fusible film and a metal foil, and can maintain the adhesive strength at a high level even when immersed in an electrolyte for a long time.
The present invention relates to an adhesive composition suitable for forming a laminate for a secondary battery container as described above.
The present invention also relates to a secondary battery using the laminate for a secondary battery container as described above.
More specifically, the present invention relates to a laminate for a non-aqueous electrolyte secondary battery, an adhesive composition for forming the laminate, and a non-aqueous electrolyte secondary battery using the laminate.

  In recent years, with the rapid growth of electronic devices such as mobile phones and portable personal computers, the demand for lightweight and small non-aqueous electrolyte secondary batteries is increasing. Among these, a bag-shaped or tray-shaped battery container using a laminate film including a metal foil represented by aluminum foil, which can be made lighter and more compact, has attracted attention.

A battery using a bag-shaped or tray-shaped battery container is often obtained as follows.
Process 1: The laminated body used for a battery container of a bag shape or a tray shape is formed. The laminated body for battery containers generally has a form in which an exterior member / a metal foil / a heat-sealing resin film is laminated, and each constituent member is bonded with an adhesive.
Step 2: Using the laminate, a bag or a tray is formed in which at least one end is vacant with the heat fusion resin film as an inner layer.
Step 3: A plurality of electrode terminals connected to the bag and the tray, respectively, to the battery body and the positive and negative electrodes of the battery body (the other end of the electrode terminal protrudes from the bag and the tray) And electrolyte.
Step 4: And in the case of a bag shape, the heat sealing resin film in a state where the heat sealing resin films near the open end face each other and the other end of the electrode terminal protrudes from the open end to the outside of the bag. The battery body and the electrolyte are sealed by sandwiching between the films and thermally fusing the vicinity of the open end.
In the case of a tray shape, the heat fusion resin film constituting the flat laminate is opposed to the heat fusion resin film at the edge of the tray, and the other end of the electrode terminal is placed outside the tray from the tray edge. The battery main body, the electrolyte, and the like are sealed by sandwiching between the heat-sealing resin films in a protruding state and heat-sealing the edge of the tray.

Therefore, the following performance is mainly required for the adhesive for bonding the metal foil and the heat-sealing resin film in the battery container laminate.
(1) The adhesive strength between the metal foil and the heat-sealing resin film is large.
(2) The adhesive layer has an electrolyte solution resistance. That is, the adhesive strength between the metal foil and the heat-sealing resin film can be maintained even if the electrolyte is sealed in the battery container.
For example, the electrolyte solution of a lithium battery includes a lithium salt such as lithium hexafluorophosphate and a solvent such as propylene carbonate, ethylene carbonate, diethyl carbonate, and dimethyl carbonate.
When the electrolyte solution is put into the battery container, the electrolyte solution passes through the heat-sealing resin film, reaches the adhesive layer, and causes a decrease in the adhesive strength between the heat-sealing resin film and the metal foil. Further, when moisture enters 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 passes through the heat-sealing resin film and the adhesive layer, reaches the metal foil, and corrodes the metal foil. This corrosion significantly reduces the adhesive force between the heat-sealing resin film and the metal foil.
Therefore, the adhesive layer for bonding the heat-sealing resin film and the metal foil is required to have resistance to the electrolyte solution.
Among them, the electrolyte solution resistance differs depending on whether the battery is used for consumer use or for in-vehicle use, and the in-vehicle use requires better electrolyte solution resistance.

Patent Document 1 (Japanese Patent Laid-Open No. 2001-236932) discloses a battery package in which a modified olefin resin layer containing hydrotalcite, which is an acid receiving layer, is provided between a metal foil and an olefin resin layer. A material is disclosed. As the modified olefin resin, maleic anhydride polypropylene is disclosed.
However, since the adhesive described in Patent Document 1 has a high melting point of the resin used, sufficient adhesive strength is not exhibited unless the resin is melted at a high temperature. There was a problem that.

  Patent Document 2 (Japanese Patent Laid-Open No. 2003-123708) uses an adhesive composition containing an acid-modified thermoplastic elastomer (A) and a coupling agent (B), and laminates an unstretched polypropylene film and a nylon film. It is disclosed that a laminated body having a configuration of unstretched polypropylene film / adhesive layer / aluminum foil / nylon film is obtained by laminating with an aluminum foil, and a secondary battery is obtained using the laminated body as a packaging material. Yes. It is further disclosed that a tackifier can be included in the adhesive composition.

Furthermore, Patent Document 3 (WO 2004/041954 pamphlet) discloses an adhesive composition containing a carboxyl group-containing thermoplastic elastomer (A), a polyolefin polyol (B), a tackifier (C), and a polyfunctional isocyanate (D). Things are disclosed. And it is described that an aluminum foil, a polyethylene terephthalate film, and an unstretched polypropylene film are bonded together using the adhesive.
Further, Patent Document 4 (Japanese Patent Application Laid-Open No. 2005-063685) also discloses a similar adhesive, and using the adhesive, an aluminum foil and a thermoplastic resin film are bonded to each other, and the thermoplastic resin film is attached. It is described that it can be used as a packaging material for battery cases as an inner layer.
However, the adhesives described in Patent Documents 2 to 4 exhibit sufficient adhesive strength at a relatively low aging temperature, but cannot maintain sufficient adhesive strength in a long-term electrolytic solution test. was there.

Patent Document 5 (WO2009 / 087776 pamphlet) discloses an adhesive composition containing a carboxyl group-containing polyolefin resin such as acid-modified polypropylene and a polyfunctional isocyanate, and discloses the use of a tackifier. Yes.
Further, Patent Document 6 (Japanese Patent Laid-Open No. 2010-092703) also discloses a similar adhesive, and using the adhesive, an aluminum foil and a thermoplastic resin film are bonded to each other, and the thermoplastic resin film is attached. It is described that it can be used as a packaging material for battery cases as an inner layer.
However, the adhesives described in Patent Documents 5 and 6 improve the adhesive strength retention after the electrolyte resistance test, but the polyfunctional isocyanate reacts with the carboxyl group-containing polyolefin resin to express the physical properties of the adhesive. In order to do so, a long aging period is required.
Further, when a highly reactive polyfunctional isocyanate is used to develop physical properties in a shorter aging period, there is a problem that the usable time (pot life) of the adhesive is remarkably deteriorated.
Thus, from the viewpoint of productivity, development of an adhesive that exhibits excellent physical properties in a shorter aging period and has a long-term pot life has been demanded.

JP 2001-236932 A JP 2003-123708 A WO2004 / 041954 pamphlet Japanese Patent Laying-Open No. 2005-063685 WO2009 / 087776 pamphlet JP 2010-092703 A

  The present invention has a high adhesive strength in a short aging period in bonding a heat-fusible film and a metal foil, has a long pot life, and has a high adhesive strength even when immersed in an electrolyte solution for a long time. It is an object of the present invention to provide an adhesive composition excellent in productivity that can form a laminate that can be maintained at a level.

The present invention is an adhesive composition containing the following (A) to (D),
In a total of 100% by weight of the amorphous polyolefin resin (A) containing the amorphous polyolefin resin (A1) having a carboxyl group and the tackifier (B), the carboxyl group-containing amorphous polyolefin resin (A1 20 to 90% by weight, and 10 to 80% by weight of the tackifier (B),
The amount of carboxyl groups derived from the carboxyl group-containing amorphous polyolefin resin (A1) contained in a total of 1 g of the amorphous polyolefin resin (A) and the tackifier (B) is 0.001 to 0.00. 675 (mmol),
The aziridine group-containing compound (C) is contained in a range where the amount of the aziridine group is 0.3 to 10 mol with respect to a total of 1 mol of the carboxyl groups,
The present invention relates to an adhesive composition containing 0.5 mol or more of tertiary amine (D) having a boiling point of 70 to 300 ° C. with respect to a total of 1 mol of the carboxyl groups.
In the adhesive composition of the present invention, the tackifier (B) is preferably a hydrogenated petroleum resin.

Further, the present invention is a laminate in which a metal foil and a heat-fusible film are laminated via an adhesive layer, and the adhesive layer is formed from the adhesive composition of the present invention. It is related with the laminated body which is an adhesive layer.
The laminate of the present invention is preferably formed by further laminating another sheet-like member on the metal foil side.

In addition, the present invention provides a metal foil or one surface of a heat-fusible film,
Applying the adhesive composition of the present invention, forming an uncured adhesive layer,
On the surface of the uncured adhesive layer, a heat-sealable film or a metal foil is overlaid,
The present invention relates to a method for producing a laminate of a metal foil and a heat-fusible film, wherein the uncured adhesive layer is cured and the metal foil and the heat-fusible film are bonded together.

Furthermore, the present invention is a secondary battery comprising a battery body, a plurality of terminals joined to the positive electrode and the negative electrode of the battery body, a battery container, and an electrolyte,
The battery container is a laminate in which a metal foil and a heat-fusible film are laminated via an adhesive layer, and the heat-fusible film is in contact with the electrolyte,
The battery main body, the plurality of terminals, and the electrolyte are connected to the battery container in a state where the other ends of the plurality of terminals protrude from the battery container by heat fusion of a part of the heat-fusible film. Sealed inside,
The present invention relates to a secondary battery in which the adhesive layer is an adhesive layer formed from the adhesive composition of the present invention.
In the secondary battery of the present invention, the laminate forming the battery container is preferably a laminate further including another sheet-like member on the metal foil side.

  With the adhesive composition of the present invention, it is possible to obtain a laminate in which a heat-fusible film and a metal foil are bonded together with high adhesive strength in a short aging period. And even if the said laminated body is immersed in electrolyte solution, the adhesive strength can be maintained at a high level, and the container for secondary batteries excellent in electrolyte solution resistance can be provided.

The amorphous polyolefin resin (A) used in the present invention will be described.
The “polyolefin resin” in the present invention means homopolymerization of an olefin monomer exemplified by ethylene, propylene, butene, butadiene, isoprene or the like, or copolymerization with other monomers, and a hydride or halogen of the obtained polymer. This refers to a polymer mainly composed of a hydrocarbon skeleton such as a chemical compound. It is important that these are non-crystalline because they are excellent in solubility in solvents. Hereinafter, the non-crystalline polyolefin resin (A) exemplified above is referred to as “non-crystalline polyolefin resin (A)”.
In the present invention, “non-crystalline” means that 10 g of resin is added to 90 g of toluene, and heated (for example, heated in a reflux state) to dissolve the resin to obtain a transparent solution. It means that the solution does not precipitate even when cooled to 25 ° C. and left at the same temperature for one week.

  Examples of the “amorphous polyolefin resin” include those that are liquid at normal temperature, that is, 25 ° C., and those that are solid at normal temperature.

  Examples of the “amorphous polyolefin resin (A)” that is liquid at room temperature include isoprene polymers, butadiene polymers, and hydrides thereof.

  Examples of the “amorphous polyolefin resin (A)” that is solid at room temperature include ethylene polymer halides, propylene polymer halides, styrene-butadiene block copolymers, styrene-isoprene block copolymers, styrene- Styrene block copolymers such as butadiene-styrene block copolymers, styrene-isoprene-styrene block copolymers, styrene-butadiene-isoprene-styrene block copolymers, and partially hydrogenated copolymers of these copolymers Examples thereof include a polymer, a completely hydrogenated copolymer, an ethylene- (meth) acrylate copolymer, an ethylene-vinyl acetate copolymer, and a propylene- (meth) acrylate polymer.

The “amorphous polyolefin resin (A)” has excellent adhesion strength to a metal substrate and has a carboxyl group in the structure because it forms a strong crosslinked structure with the aziridine group-containing compound (C) described later. It is important to contain the amorphous polyolefin resin (A1) as an essential component.
As a method for introducing a carboxyl group into the “non-crystalline polyolefin resin”, an appropriate amount of ethylenic acid such as maleic acid or maleic anhydride is used in the polymerization of the monomer for producing the above-mentioned “non-crystalline polyolefin resin”. A method of copolymerizing an unsaturated carboxylic acid or an anhydride of the unsaturated carboxylic acid, or after synthesizing an “amorphous polyolefin resin”, an appropriate amount of an ethylenically unsaturated carboxylic acid such as maleic acid or maleic anhydride, A general method is a grafting reaction using an unsaturated carboxylic acid anhydride and a peroxide. The amorphous polyolefin resin having a carboxyl group introduced into the structure by the method exemplified above is also referred to as a carboxyl group-containing amorphous polyolefin resin (A1).

  When an amorphous polyolefin resin (A1) having a carboxyl group used in the present invention is obtained, an anhydride of an ethylenically unsaturated carboxylic acid is used as a monomer, and an anhydride of a carboxylic acid is used when used as an adhesive. These may be used in a state of being opened, or they may be used in a state of being ring-opened with water, alcohol, alkylamine or the like.

  The acid value of the carboxyl group-containing amorphous polyolefin resin (A1) used in the present invention is preferably 0.005 to 0.75 (mmol / g), more preferably 0.01 to 0.65. (Mmol / g). When the acid value of the carboxyl group-containing amorphous polyolefin resin (A1) is lower than 0.005 (mmol / g), the adhesion strength to the metal substrate is not sufficient, or the aziridine-containing compound (C) described later There is a risk that the cross-linked structure obtained by the reaction with is insufficient, and sufficient resistance to the electrolytic solution cannot be obtained. In addition, when the acid value is higher than 0.75 (mmol / g), unreacted carboxyl group-containing monomers not incorporated in the polyolefin skeleton at the time of synthesis increase in the adhesive, and the viscoelasticity of the cured coating film May be damaged.

Among the commercially available products of carboxyl group-containing amorphous polyolefin resin (A1) used in the present invention,
As liquid at room temperature, that is, 25 ° C., Kuraray Co., Ltd., Claprene LIR-403, LIR-410 (above, carboxyl group-containing isoprene copolymer), Nippon Soda Co., Ltd. NISSO-PB C-1000, Examples thereof include BN-1015 (above, carboxyl group-containing polybutadiene), CN-1000 (carboxyl group-containing hydrogenated polybutadiene), and the like.
As solids at room temperature, Tough Tech M1911, M1913 manufactured by Asahi Kasei Chemicals Co., Ltd., Kraton FG1901 manufactured by Kraton Polymer Japan Co., Ltd. (above, carboxyl group-containing hydrogenated styrene-butadiene-styrene copolymer), Nippon Paper Chemical Co. Supercron 822, 842L (a chlorinated product of a carboxyl group-containing propylene polymer), Aurolen 200, 350S (above, a carboxyl group-containing propylene-acrylate ester copolymer) and the like are available.

  When the carboxyl group-containing amorphous polyolefin resin (A1) used in the present invention is a styrene block copolymer, the structure preferably contains 5 to 60% by weight of styrene units, more preferably 10 to 10%. 40% by weight. When the styrene unit of the carboxyl group-containing styrene-based amorphous polyolefin resin (A1) is less than 5% by weight, sufficient viscoelasticity may not be obtained. When the styrene unit is more than 60% by weight, Since there are too many styrene units which are hard blocks, there is a possibility that the wettability to the substrate is insufficient and the adhesive force is impaired.

  In the present invention, the amorphous polyolefin resin (A2) having no carboxyl group in addition to the carboxyl group-containing amorphous polyolefin resin (A1) is used as the amorphous polyolefin resin (A) as long as the effects of the invention are not impaired. ) May be used in combination.

Of the commercially available non-crystalline polyolefin resin (A2) containing no carboxyl group used in the present invention,
As a liquid at room temperature, that is, 25 ° C., Kuraray Co., Ltd. Kuraprene LIR-30 (isoprene polymer), LIR-200 (hydrogenated isoprene polymer), LBR-300 (butadiene polymer), Nippon Soda Co., Ltd. Examples include NISSO-PB BI-3000 (hydrogenated butadiene polymer) manufactured by the company.
As solids at normal temperature, Kuraray Co., Ltd. Septon 2002, 2004 (above, hydrogenated styrene-isoprene-styrene copolymer), 2104, 4033, HG252 (above, hydrogenated styrene-isoprene / butadiene-styrene copolymer) Polymer), Asaprene T-432 and T-437 manufactured by Asahi Kasei Chemicals Co., Ltd., Kraton D1155 manufactured by Kraton Polymer Japan Co., Ltd. (above, styrene-butadiene-styrene copolymer), Epofriend manufactured by Daicel Chemical Industries, Ltd. AT501 (epoxidized styrene-butadiene-styrene copolymer), Tuftec P1500, P2000, MP10 (partially hydrogenated styrene-butadiene-styrene copolymer) manufactured by Asahi Kasei Chemicals Corporation, H1052, H1043 (above, hydrogenated styrene) Butadiene - styrene copolymer), etc. Nippon Paper Chemicals Co., Ltd. of Superchlon C (chlorinated propylene polymer) and the like.

  When the non-crystalline polyolefin resin (A2) containing no carboxyl group used in the present invention is a styrene block copolymer, it is preferable that 10 to 90% by weight of styrene units are contained in the structure. When the styrene unit of the styrene-based amorphous polyolefin resin (A2) containing no carboxyl group is less than 10% by weight, sufficient viscoelasticity may not be obtained. When the styrene unit is more than 90% by weight, the compatibility with the above-mentioned carboxyl group-containing amorphous polyolefin resin (A1) is deteriorated, and the adhesive force may be impaired.

When two or more kinds of carboxyl group-containing amorphous polyolefin resin (A1) essential as the amorphous polyolefin resin (A) are used in combination, the compatibility between the resins is good and the leveling property of the coating film is good. The combination of is preferable.
That is, it is preferable to use a non-hydrogenated product or a partially hydrogenated product in combination with a non-hydrogenated product. It is preferable to use a completely hydrogenated product or a partially hydrogenated product in combination with a completely hydrogenated product.

Also when using together amorphous polyolefin resin (A2) which does not contain a carboxyl group, the following combinations are preferred for the same reason as the above.
That is, when using non-hydrogenated carboxyl group-containing amorphous resin (A1), non-hydrogenated polyolefin resin (A2) containing no carboxyl group is not partially hydrogenated or partially It is preferable to use hydrogenated compounds in combination.
On the other hand, when using a completely hydrogenated carboxyl group-containing amorphous resin (A1), as the amorphous polyolefin resin (A2) not containing a carboxyl group, It is preferable to use a partially hydrogenated product in combination.

Next, the tackifier (B) used in the present invention will be described. In the present invention, the tackifier (B) is used for imparting high adhesive strength between the metal foil and the heat-fusible film.
Examples of the tackifier (B) used in the present invention include polyterpene resins, rosin resins, aliphatic petroleum resins, alicyclic petroleum resins, copolymer petroleum resins, styrene resins, and hydrogenated petroleum resins. And is used for the purpose of improving the adhesive strength. These may be used alone or in any combination of two or more.

  Specific examples of the polyterpene resin include α-pinene polymers, β-pinene polymers, and copolymers thereof with phenol, bisphenol A, and styrene. Commercially available products include, for example, Yasuhara Chemical Co., Ltd. Examples thereof include YS Resin PX, YS Resin A, and YS Polyster T.

  Examples of the rosin-based resin include natural rosin, polymerized rosin, and ester derivatives thereof. Examples of commercially available products include Pencel A, Super Ester A, Pine Crystal KR-85, KR manufactured by Arakawa Chemical Industries, Ltd. -612, KR-614, KE-100, KE-311, KE-359, KE-604 and the like.

  The aliphatic petroleum resin is generally a resin synthesized from a C5 fraction of petroleum. Examples of commercially available products include Escorez manufactured by Tonex Co., Ltd., Quinton manufactured by Zeon Corporation, and Wing Duck manufactured by Goodyear.

  The alicyclic petroleum resin is generally a resin synthesized from a C9 fraction of petroleum. Examples of commercially available products include Marukaretsu manufactured by Maruzen Petrochemical Co., Ltd.

  The copolymer petroleum resin is generally a resin obtained by copolymerizing petroleum C5 / C9. Examples of commercially available products include Toho High Resin from Toho Chemical Industry Co., Ltd.

  The styrene resin is generally a low molecular weight polystyrene polymer, and examples of commercially available products include YS Resin SX manufactured by Yashara Chemical Co., Ltd. and Alfon UP-1150 manufactured by Toagosei Co., Ltd.

The hydrogenated petroleum resin is obtained by hydrogenating the above petroleum resin (aliphatic petroleum resin, alicyclic petroleum resin, copolymer petroleum resin). Examples of commercially available products include Alcon manufactured by Arakawa Chemical Co., Ltd., Clearon manufactured by Yashara Chemical Co., Ltd.
The tackifier (B) used in the present invention is preferably a hydrogenated petroleum resin because it is excellent in adhesion to the heat-fusible film.

  The softening point of the tackifier (B) used in the present invention is preferably 60 to 160 ° C, and more preferably 80 to 150 ° C. When the softening point of the tackifier (B) is lower than 60 ° C., there is a possibility that sufficient effect of improving the adhesive strength cannot be obtained. Moreover, when the softening point of a tackifier (B) is higher than 160 degreeC, there exists a possibility that the cohesive force of an adhesive agent may be impaired and the adhesive strength may fall.

  The acid value of the tackifier (B) used in the present invention is preferably 0 to 3.0 (mmol / g), more preferably 0 to 2.0 (mmol / g). Depending on the type of the heat-sealing resin film used for the lamination, a higher adhesive strength may be obtained immediately after the lamination when the tackifier having a carboxyl group is used. On the other hand, if the acid value is too high, it will be difficult to dissolve in toluene or the like used for the adhesive, or other components constituting the adhesive, such as a carboxyl group-containing amorphous polyolefin resin (A1) or a carboxyl group. The compatibility with the non-crystalline polyolefin resin (A2) which does not become worse. Therefore, the acid value of the tackifier (B) is preferably 0 to 3.0 (mmol / g).

  In the adhesive composition of the present invention, the total amount of the amorphous polyolefin resin (A) containing the carboxyl group-containing amorphous polyolefin resin (A1) as an essential component and the tackifier (B) is 100% by weight. It is important that the carboxyl group-containing amorphous polyolefin resin (A1) is contained in an amount of 20 to 90% by weight and the tackifier (B) is contained in an amount of 10 to 80% by weight. More preferably, 30 to 70% by weight of the conductive polyolefin resin (A1) and 20 to 70% by weight of the tackifier (B) are included. When the amorphous polyolefin resin (A2) having no carboxyl group is included, the content is preferably 60% by weight or less, and more preferably 40% by weight or less.

  When the content of the carboxyl group-containing non-crystalline polyolefin resin (A1) is less than 20% by weight, the cohesive force of the adhesive may be insufficient and sufficient adhesive strength may not be obtained. In addition, when the content of the carboxyl group-containing amorphous polyolefin resin (A1) is more than 90% by weight, the amount of the tackifier (B) is relatively small, so that the addition of the tackifier (B) is sufficient. There is a risk that a sufficient adhesive strength cannot be obtained.

  On the other hand, when the content of the tackifier (B) is less than 10% by weight, the effect of improving the adhesive strength due to the addition of the tackifier (B) may not be obtained. Moreover, when there is more content of tackifier (B) than 80 weight%, there exists a possibility that the cohesive force of an adhesive bond layer may become insufficient and sufficient adhesive strength may not be obtained.

When the content of the amorphous polyolefin resin (A2) having no carboxyl group is more than 60% by weight, the content of the carboxyl group-containing amorphous polyolefin resin (A1) or the tackifier (B) is relatively Therefore, the reaction between the carboxyl group-containing non-crystalline polyolefin resin (A1) and the aziridine group-containing compound described below does not proceed sufficiently and the cross-linked structure is insufficient, so that the resistance to electrolyte solution is deteriorated or tackified. There is a possibility that the adhesion improving effect by the agent (B) may not be sufficiently obtained.

Furthermore, the adhesive composition of the present invention is derived from the carboxyl group-containing amorphous polyolefin resin (A1) contained in a total of 1 g of the amorphous polyolefin resin (A) and the tackifier (B). It is important that the amount of the carboxyl group is 0.001 to 0.675 (mmol), and preferably 0.01 to 0.5 (mmol). If the amount of the carboxyl group is too small, the cross-linked structure formed by the reaction with the aziridine group-containing compound described later is insufficient, and sufficient electrolyte resistance may not be obtained, and if it is too large, the tackifier (B). There is a risk that compatibility with other components may deteriorate.

As said tackifier (B), what has a carboxyl group can be used, and what does not have can also be used, but the quantity of the carboxyl group in the said tackifier (B) is the said carboxyl group. The amount is preferably 8 mol or less, more preferably 0 to 4.5 mol based on 1 mol of the carboxyl group in the containing amorphous polyolefin resin (A1). When the carboxyl group derived from the tackifier (B) is larger than 8.0, compatibility with other components may be deteriorated and sufficient adhesive strength may not be obtained.

  The adhesive composition of the present invention contains an aziridine group-containing compound (C) as a curable component that reacts with the carboxyl group in the carboxyl group-containing amorphous polyolefin resin (A1) or the tackifier (B). .

  The aziridine group-containing compound (C) used in the present invention has extremely high reactivity with the carboxyl group in the carboxyl group-containing amorphous polyolefin resin (A1) and the tackifier (B), and is heat-fusible. The adhesiveness with the film is remarkably improved, and high adhesive strength is imparted to the adhesive by short-term aging (for example, usually at 40 ° C. for 5 days and at 40 ° C. for about 1 day). Moreover, since the crosslinked structure obtained by reaction has high electrolyte solution tolerance, electrolyte solution tolerance is given to an adhesive agent.

  In the aziridine group-containing compound (C) used in the present invention, the number of aziridine groups per molecule is preferably 1.5 or more, and more preferably 2 or more. When the number of the aziridine group-containing compound (C) per molecule is less than 1.5, the reaction with the carboxyl group in the structure of the carboxyl group-containing amorphous polyolefin resin (A1) or tackifier (B) The cross-linking density of the cross-linked structure obtained by this may be insufficient, and the electrolyte resistance may be insufficient.

  Examples of the aziridine group-containing compound (C) used in the present invention include N, N′-hexamethylene-1,6-bis (1-aziridinecarboxamide), N, N′-diphenylmethane-4,4 ′. -Bis (1-aziridinecarboxamide), trimethylolpropane-tri-β-aziridinylpropionate), N, N′-toluene-2,4-bis (1-aziridinecarboxyamide), triethylenemelamine, Trimethylolpropane-tri-β (2-methylaziridine) propionate, bisisophthaloyl-1-methylaziridine, tri-1-aziridinylphosphine oxide, tris-1-methylaziridinephosphine oxide, etc. Can be mentioned.

Examples of commercially available products of the aziridine group-containing compound (C) used in the present invention include Chemitite PZ-33 manufactured by Nippon Shokubai Co., Ltd.

In the adhesive composition of the present invention, the amount of the aziridine group is 0 with respect to 1 mol in total of the carboxyl group derived from the carboxyl group-containing amorphous polyolefin resin (A1) and the carboxyl group derived from the tackifier (B). It is important to contain the aziridine group-containing compound (C) in a range of 3 to 10 mol, and the amount of the aziridine group is preferably 0.5 to 6 mol. (Hereinafter, the equivalent ratio of all aziridine groups of the aziridine group-containing compound (C) to the sum of the carboxyl groups of the carboxyl group-containing amorphous polyolefin resin (A1) and the carboxyl group of the tackifier (B) is referred to as aziridine / COOH ratio. Call it.)
When the aziridine / COOH ratio is less than 0.3, the cross-linked structure due to the reaction between the carboxyl group-containing amorphous polyolefin resin (A) and the tackifier (B) is insufficient, and the electrolyte resistance may be insufficient. On the other hand, if the aziridine / COOH ratio is greater than 10, the amount of unreacted aziridine compound increases, which may impair the adhesive strength and electrolyte resistance.

  Since the aziridine group-containing compound (C) has a very high reactivity with a carboxyl group, the reaction proceeds with time during the coating of the adhesive, and the viscosity tends to increase. Therefore, the adhesive composition of the present invention contains a tertiary amine (D) in order to moderately suppress the reaction and suppress an extreme increase in viscosity. The addition of the tertiary amine (D) suppresses the reaction between the carboxyl group and the aziridine group-containing compound (C), and the usable time (pot life) after blending the adhesive is significantly improved.

The tertiary amine (D) used in the present invention volatilizes with the solvent during the drying step, whereby the carboxyl group-containing amorphous polyolefin (A1) and the tackifier (B) carboxyl group and aziridine group-containing compound (C ).
Therefore, a boiling point that can be volatilized with the solvent during the drying step, for example, a boiling point range of 70 ° C. to 300 ° C. is preferable, and a range of 120 ° C. to 250 ° C. in terms of a good balance between volatilization during coating and drying properties. Is more preferable.
If the boiling point of the tertiary amine (D) is lower than 70 ° C., the amount of volatilization increases over time and the odor is stiff during coating. The amount of the tertiary amine (D) changes during the coating over time, causing a crosslinking reaction. There is a risk that the suppression effect cannot be obtained sufficiently. Further, if the boiling point of the tertiary amine (D) is higher than 300 ° C., the tertiary amine (D) cannot be sufficiently volatilized during solvent drying or aging, thereby inhibiting the crosslinking reaction of the aziridine-containing compound (C). As a result, the adhesive strength and the resistance to electrolytes may be insufficient.

  Examples of the tertiary amine (D) used in the present invention include triethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, dimethylbenzylamine, diisopropylethylamine and the like. These may be used alone or in combination of two or more.

  The content of the tertiary amine (D) used in the present invention is 1 mol in total of the carboxyl group derived from the carboxyl group-containing amorphous polyolefin resin (A1) and the carboxyl group derived from the tackifier (B). When the equivalent ratio of the tertiary amine (D) is 0.5 mol or more, the reaction suppressing effect of the aziridine group-containing compound (C) is obtained, preferably 1 mol or more, more preferably 3 mol or more. (Hereinafter, the equivalent ratio of all the tertiary amines (D) to the total of the carboxyl groups derived from the carboxyl group-containing amorphous polyolefin resin (A) and the carboxyl groups derived from the tackifier (B) is referred to as the amine / COOH ratio. ) If the amine / COOH ratio is less than 0.5 mole, the pot life of the adhesive may be deteriorated.

The tertiary amine (D) is considered to suppress the reaction by forming a salt with the carboxyl group of the carboxyl group-containing amorphous polyolefin resin (A) or tackifier (B). The blending amount of) does not impair the solubility of the components blended in the adhesive, and if it volatilizes in the solvent drying step or the aging step, the greater the blending amount of the tertiary amine (D), the more the aziridine group-containing compound (C ) Reaction suppression effect increases.
Moreover, since the reaction inhibitory effect per tertiary amine (D) molecule | numerator becomes high, so that the structure of tertiary amine (D) is bulky, it is high with few compounding quantities, so that the structure of tertiary amine (D) becomes bulky. A reaction suppressing effect can be obtained.

  The organic solvent that can be used in the adhesive of the present invention can dissolve the material used in the present adhesive alone or as a mixed solvent, is inactive with the aziridine group-containing compound (C), and is applied when the adhesive is applied. If it can volatilize and remove by the overheating in the drying process of this, it will not specifically limit. Specific examples of these solvents include aromatic organic solvents such as toluene and xylene, aliphatic organic solvents such as n-hexane, alicyclic organic solvents such as cyclohexane and methylcyclohexane, and ketones such as methyl ethyl ketone. Examples of the solvent include ester solvents such as ethyl acetate and the like, and these may be used alone or in combination of two or more. Further, the tertiary amine (D) as described above may be used as the organic solvent component of the adhesive.

In the adhesive of the present invention, the crosslinking reaction between the carboxyl group of the carboxyl group-containing polyolefin resin (A1) and the tackifier (B) and the aziridine group-containing compound (C) proceeds in a very short time, and the reaction is completed. The influence of the wettability of the adhesive on the base material is increased, and by changing the balance between the elasticity and viscosity of the adhesive, the maximum adhesive force value that can be expressed and the aging to express the maximum adhesive force value The period can be changed.
For example, the higher the elasticity of the adhesive, the higher the value of the maximum adhesive force that can be expressed as compared to a highly viscous adhesive. However, in order to obtain the maximum adhesive force, it is necessary to ensure sufficient wetting to the substrate, and when using a highly elastic adhesive, a longer aging period is required compared to a highly viscous adhesive. .
On the other hand, the higher the adhesive viscosity is, the shorter the aging period is and the higher the adhesive strength of the adhesive can be obtained. The force value tends to be lower than that of a highly elastic adhesive.

The balance between elasticity and viscosity of the adhesive of the present invention is that the carboxyl group-containing amorphous polyolefin resin (A1) that is liquid at room temperature or the amorphous polyolefin resin (A2) that does not have a carboxyl group that is liquid at room temperature, It can be adjusted by the blending balance of the carboxyl group-containing polyolefin resin (A1) that is solid at ordinary temperature or the amorphous polyolefin resin (A2) that does not have a carboxyl group that is solid at ordinary temperature.
For example, when it is desired to obtain the value of the maximum adhesive force in a shorter aging period, the amorphous polyolefin resin (A1) containing a carboxyl group that is liquid at room temperature or the non-crystalline polyolefin resin (A2) that does not have a carboxyl group that is liquid at room temperature. This is achieved by increasing the blending amount of In order to obtain a higher value of maximum adhesive strength, a compound of a non-crystalline polyolefin resin (A) containing a solid carboxyl group at room temperature or a non-crystalline polyolefin resin (A2) having no solid carboxyl group at normal temperature is used. This is achieved by increasing the amount.

The adhesive composition of the present invention is suitably used for laminating a metal foil and a heat-fusible film.
Examples of the metal of the metal foil include aluminum, copper, and nickel. These metal foils may be subjected to various surface treatments. Examples of the surface treatment include chemical treatment such as physical treatment such as sand blast treatment and polishing treatment, degreasing treatment by vapor deposition, etching treatment, and primer treatment applying a coupling agent or coating agent.
Examples of the heat-fusible film include polyolefin films such as polyethylene and polypropylene, and an unstretched film is particularly preferably used.

A laminate using the adhesive composition of the present invention can be obtained, for example, as follows.
The adhesive composition of the present invention is applied to one surface of a metal foil (or heat-fusible film), the solvent is stripped (dried), and an uncured adhesive layer is formed. After stacking a heat-fusible film (or metal foil) on the surface of the uncured adhesive layer under pressure at 0 ° C., leave it at 40 to 80 ° C. for about 3 to 7 days. It is cured (also referred to as aging), and the metal foil and the heat-fusible film are bonded together.
For coating of the adhesive composition, a general coating machine such as a comma coater can be used. The thickness (amount) of the cured adhesive layer at the time of dry curing is preferably about 1 to 30 g / m ² .

In addition, metal foil can comprise another sheet-like member on the other surface (the surface where the adhesive layer formed from the adhesive composition of the present invention is not in contact).
Other sheet-like members may be laminated on a metal foil in advance using an adhesive composition (may be the same as or different from the adhesive composition of the present invention), After obtaining the laminated body of metal foil and a heat-fusible film using the adhesive composition of this invention, another sheet-like member can also be laminated | stacked on metal foil.
Other sheet-like members used include stretched films such as polyester resins and polyamide resins (nylon), and the other sheet-like members serve as exterior members when the laminate becomes a battery container.

A battery container for a secondary battery using a laminate formed by laminating a metal foil and a heat-fusible film using the adhesive composition of the present invention will be described. The laminated body using the adhesive composition of the present invention is suitably used for forming a battery container of a secondary battery, particularly a nonaqueous electrolyte secondary battery.
The secondary battery includes a battery body, a plurality of terminals respectively joined to the positive electrode and the negative electrode of the battery body, a battery container, and an electrolyte. The battery container is obtained from a laminate in which a metal foil and a heat-fusible film are laminated via an adhesive layer formed from the adhesive composition of the present invention, and the heat-sealing The conductive film is in contact with the electrolyte.

  Battery containers include a pouch type container for a bag-like container and a tray-shaped container type formed by molding a flat laminate using a mold. One form of the bag-like container is illustrated in FIG. 8 of JP-A-2007-2949481. Further, one form of the tray-like container is shown in FIG. 9 of the publication, and the other form is shown in FIG. The laminate using the adhesive composition of the present invention can be used to form both types of containers, bags and trays. In either case, a part of the heat-fusible film is heat-sealed in a state where the heat-fusible film faces inward and the tips of the plurality of terminals protrude to the outside. Seal the electrolyte solution.

  The electrolyte solution starts to penetrate from the heat-fusible plastic sheet toward the metal foil, but the adhesive layer formed from the adhesive composition of the present invention is excellent in resistance to the electrolyte solution, so heat fusion The adhesive strength between the conductive plastic sheet and the metal foil does not decrease, and problems such as liquid leakage do not occur.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, a following example does not restrict | limit the right range of this invention at all. In addition, each evaluation in an Example followed the following method. In the examples, parts are parts by weight,% is% by weight, and the acid value is mmol / g.
In addition,

<Main agent 1>
As a carboxyl group-containing amorphous polyolefin resin (A1), maleic acid-modified hydrogenated SBS Tuftec M1911 (styrene content 30% by weight, acid value 0.04 mmol / g, solid at room temperature) manufactured by Asahi Kasei Kogyo Co., Ltd .: 85 parts, adhesive Rosin ester pine crystal KE-100 (softening point 100 ° C., acid value 0.11 mmol / g) manufactured by Arakawa Chemical Co., Ltd. as an imparting agent (B): 15 parts are put into a container, and toluene / methyl ethyl ketone = 8/2 is mixed. The mixture was diluted with a solvent and stirred with heating at 50 ° C. for 3 hours to obtain a solution of the main agent 1 (solid content 30%). In addition, the amount of the carboxyl group derived from the carboxyl group-containing amorphous polyolefin resin (A1) contained in a total of 1 g of the amorphous polyolefin resin (A1) and the tackifier (B) is 0.034 ( mmol).

<Main agent 2>
As a carboxyl group-containing amorphous polyolefin resin (A1), Kuraray Co., Ltd. maleic acid-modified polyisoprene half-esterified product Claprene LIR-410 (acid value 0.33 mmol / g, liquid at room temperature): 25 parts, tackifier ( B) Hydrogenated terpene resin manufactured by Yashara Chemical Co., Ltd. Clearon P85 (softening point 85 ° C., no acid value): 75 parts are put in a container, diluted with a mixed solvent of toluene / methyl ethyl ketone = 8/2, and 3 hours at 50 ° C. The mixture was heated and stirred to obtain a solution of the main agent 2 (solid content 30%). In addition, the amount of the carboxyl group derived from the carboxyl group-containing amorphous polyolefin resin (A1) contained in a total of 1 g of the amorphous polyolefin resin (A1) and the tackifier (B) is 0.083 ( mmol).

<Main agent 3>
As the carboxyl group-containing amorphous polyolefin resin (A1), maleic acid-modified hydrogenated SBS Tuftec M1943 (styrene content 20% by weight, acid value 0.19 mmol / g, solid at room temperature) manufactured by Asahi Kasei Kogyo Co., Ltd .: 50 parts, carboxyl Hydrogenated SIS Septon 2002 (Styrene content 30% by weight, no acid value, solid at normal temperature): 10 parts as an amorphous polyolefin resin (A2) having no group: Arakawa as a tackifier (B) Chemical Industry Co., Ltd. rosin ester Pine Crystal KR-50M (softening point 150 ° C., acid value 1.7 mmol / g): 40 parts are put into a container and diluted with a mixed solvent of toluene / methyl ethyl ketone = 8/2 to 50 ° C. And stirred for 3 hours to obtain a solution of the main agent 3 (solid content 30%). In addition, the amount of the carboxyl group derived from the carboxyl group-containing amorphous polyolefin resin (A1) contained in 1 g in total of the amorphous polyolefin resins (A1) and (A2) and the tackifier (B) is It was 0.095 (mmol).

<Main agent 4>
As a carboxyl group-containing amorphous polyolefin resin (A1), Nippon Paper Chemicals Co., Ltd. maleic acid-modified chlorinated polypropylene Super Clon 892L (acid value 0.34 mmol / g, solid at room temperature): 50 parts, no carboxyl group As a non-crystalline polyolefin resin (A2), hydrogenated isoprene manufactured by Kuraray Co., Ltd. Claprene LIR-200 (no acid value, liquid at room temperature): 10 parts, aromatic modified hydrogenated product manufactured by Yashara Chemical Co., Ltd. as a tackifier (B) Terpene resin Clearon M115 (softening point 115 ° C., no acid value): 40 parts are put in a container, diluted with a mixed solvent of toluene / methyl ethyl ketone = 8/2, heated and stirred at 50 ° C. for 3 hours, Solid content 30%) was obtained. In addition, the amount of the carboxyl group derived from the carboxyl group-containing amorphous polyolefin resin (A1) contained in 1 g in total of the amorphous polyolefin resins (A1) and (A2) and the tackifier (B) is It was 0.170 (mmol).

<Main agent 5>
As carboxyl group-containing amorphous polyolefin resin (A1), Kuraray Co., Ltd. maleic acid-modified polyisoprene Claprene LIR-403 (acid value 0.18 mmol / g, liquid at room temperature): 50 parts, as tackifier (B) Yasuhara Chemical Co., Ltd. hydrogenated terpene resin Clearon P150 (softening point 150 ° C., no acid value): 50 parts are put into a container, diluted with a mixed solvent of toluene / methyl ethyl ketone = 8/2, and heated and stirred at 50 ° C. for 3 hours. A solution of main agent 5 (solid content 30%) was obtained. In addition, the amount of the carboxyl group derived from the carboxyl group-containing amorphous polyolefin resin (A1) contained in 1 g in total of the amorphous polyolefin resin (A1) and the tackifier (B) is 0.090 ( mmol).

<Main agent 6>
As the carboxyl group-containing amorphous polyolefin resin (A1), maleic acid-modified hydrogenated SBS Tuftec M1911 (styrene content 30% by weight, acid value 0.04 mmol / g, solid at room temperature) manufactured by Asahi Kasei Kogyo Co., Ltd .: 60 parts, adhesive Yasuhara Chemical Co., Ltd. hydrogenated terpene resin Clearon P125 (softening point 125 ° C., no acid value): 40 parts in a container and diluted with a mixed solvent of toluene / methyl ethyl ketone = 8/2 as the imparting agent (B) at 50 ° C. And stirred for 3 hours to obtain a solution of the main agent 6 (solid content 30%). In addition, the amount of the carboxyl group derived from the carboxyl group-containing amorphous polyolefin resin (A1) contained in a total of 1 g of the amorphous polyolefin resin (A1) and the tackifier (B) is 0.024 ( mmol).

<Main agent 7>
As the carboxyl group-containing amorphous polyolefin resin (A1), maleic acid-modified hydrogenated SBS Tuftec M1913 manufactured by Asahi Kasei Kogyo Co., Ltd. (styrene content 30% by weight, acid value 0.19 mmol / g, solid at room temperature): 45 parts, carboxyl As non-crystalline polyolefin resin (A2) having no base, Nippon Paper Chemicals Co., Ltd. Chlorinated polypropylene Super Clone C (no acid value, solid at room temperature): 15 parts, Arakawa Chemical Industries Ltd. as tackifier (B) Company-made rosin ester Pine Crystal KE-100 (softening point 100 ° C., acid value 0.11 mmol / g): 40 parts are put into a container, diluted with a mixed solvent of toluene / methyl ethyl ketone = 8/2, and 3 hours at 50 ° C. The mixture was heated and stirred to obtain a solution of the main agent 7 (solid content 30%). In addition, the amount of the carboxyl group derived from the carboxyl group-containing amorphous polyolefin resin (A1) contained in 1 g in total of the amorphous polyolefin resins (A1) and (A2) and the tackifier (B) is It was 0.086 (mmol).

<Main agent 8>
As the carboxyl group-containing amorphous polyolefin resin (A1), maleic acid-modified hydrogenated SBS Tuftec M1913 manufactured by Asahi Kasei Kogyo Co., Ltd. (styrene content 30% by weight, acid value 0.19 mmol / g, solid at room temperature): 45 parts, carboxyl As non-crystalline polyolefin resin (A2) having no base, Nippon Paper Chemicals Co., Ltd. Chlorinated polypropylene Super Clone C (no acid value, solid at room temperature): 15 parts, Arakawa Chemical Industries Ltd. as tackifier (B) Company hydrogenated C9 resin Alcon P125 (softening point 125 ° C., no acid value): 40 parts are put into a container, diluted with a mixed solvent of toluene / methyl ethyl ketone = 8/2, and heated and stirred at 50 ° C. for 3 hours. 8 solution (solid content 30%) was obtained. In addition, the amount of the carboxyl group derived from the carboxyl group-containing amorphous polyolefin resin (A1) contained in 1 g in total of the amorphous polyolefin resins (A1) and (A2) and the tackifier (B) is It was 0.086 (mmol).

<Main agent 9>
As a carboxyl group-containing amorphous polyolefin resin (A), Kuraray Co., Ltd. maleic acid-modified polyisoprene half esterified product Claprene LIR-410 (acid value 0.33 mmol / g, liquid at room temperature): 45 parts, tackifier ( B) Rosin ester pine crystal KE-100 (softening point 100 ° C., acid value 0.11 mmol / g) manufactured by Arakawa Chemical Industries, Ltd .: Asahi Kasei as an amorphous polyolefin resin (E) containing no carboxyl group Partially hydrogenated SBS Tuftec MP10 manufactured by Chemicals Co., Ltd. (styrene content 30% by weight, no acid value, solid at room temperature): 15 parts are put into a container and diluted with a mixed solvent of toluene / methyl ethyl ketone = 8/2 at 50 ° C. The mixture was heated and stirred for 3 hours to obtain a solution of the main agent 9 (solid content 30%). In addition, the amount of the carboxyl group derived from the carboxyl group-containing amorphous polyolefin resin (A1) contained in 1 g in total of the amorphous polyolefin resins (A1) and (A2) and the tackifier (B) is It was 0.149 (mmol).

<Main agent 10>
As a carboxyl group-containing amorphous polyolefin resin (A1), Kuraray Co., Ltd. maleic acid-modified polyisoprene half esterified product Claprene LIR-410 (acid value 0.33 mmol / g, liquid at room temperature): 45 parts, having carboxyl group As a non-crystalline polyolefin resin (A2), partially hydrogenated SBS Tuftec MP10 manufactured by Asahi Kasei Chemicals Corporation (styrene content 30% by weight, no acid value, solid at room temperature): 15 parts, Yasuhara Chemical Co., Ltd. as a tackifier (B) Company hydrogenated terpene resin Clearon P150 (softening point 150 ° C., no acid value): 40 parts are put into a container, diluted with a mixed solvent of toluene / methyl ethyl ketone = 8/2, and heated and stirred at 50 ° C. for 3 hours. 10 solutions (solid content 30%) were obtained. In addition, the amount of the carboxyl group derived from the carboxyl group-containing amorphous polyolefin resin (A1) contained in 1 g in total of the amorphous polyolefin resins (A1) and (A2) and the tackifier (B) is It was 0.149 (mmol).

<Main agent 11>
As a tackifier (B), hydrogenated terpene resin Clearon P150 (softening point 150 ° C., no acid value) manufactured by Yashara Chemical Co., Ltd .: 40 parts, Asahi Kasei Chemicals Co., Ltd. as an amorphous polyolefin resin (A2) having no carboxyl group Hydrogenated SBS Tuftec H1053 (styrene content 29% by weight, no acid value, solid at room temperature): 60 parts are put into a container, diluted with a mixed solvent of toluene / methyl ethyl ketone = 8/2, and heated and stirred at 50 ° C. for 3 hours. As a result, a solution of the main agent 11 (solid content 30%) was obtained. The amount of carboxyl groups derived from the carboxyl group-containing amorphous polyolefin resin (A1) contained in a total of 1 g of the amorphous polyolefin resin (A2) and the tackifier (B) is 0.000 ( mmol).

<Main agent 12>
Maleic acid-modified polypropylene Yumex 1010 (acid value 0.93 mmol / g, solid at room temperature, with crystallinity) manufactured by Sanyo Chemical Co., Ltd. as a crystalline polyolefin resin (A1 ′) having a carboxyl group: 60 parts, tackifying As the agent (B), hydrogenated terpene resin made by Yashara Chemical Co., Ltd. Clearon P150 (softening point 150 ° C., no acid value): 40 parts are put into a container and diluted with a mixed solvent of toluene / methyl ethyl ketone = 8/2 at 50 ° C. The mixture was heated and stirred for 3 hours to obtain a solution of the main agent 12 (solid content 30%). In addition, the amount of the carboxyl group derived from the carboxyl group-containing amorphous polyolefin resin (A1 ′) contained in 1 g in total of the crystalline polyolefin resin (A1 ′) and the tackifier (B) is 0.558. (Mmol).

<Main agent 13>
As a carboxyl group-containing amorphous polyolefin resin (A1), maleic acid-modified hydrogenated SBS Tuftec M1911 manufactured by Asahi Kasei Kogyo Co., Ltd. (styrene content 30% by weight, acid value 0.04 mmol / g, solid at normal temperature): 100 parts in a container The mixture was diluted with a mixed solvent of toluene / methyl ethyl ketone = 8/2, and heated and stirred at 50 ° C. for 3 hours to obtain a solution of the main agent 13 (solid content 30%). In addition, the amount of the carboxyl group derived from the carboxyl group-containing amorphous polyolefin resin (A1) contained in a total of 1 g of the amorphous polyolefin resin (A1) and the tackifier (B) is 0.040 ( mmol).

<Main agent 14>
As the carboxyl group-containing amorphous polyolefin resin (A1), maleic acid-modified hydrogenated SBS Tuftec M1911 (styrene content 30% by weight, acid value 0.04 mmol / g, solid at room temperature) manufactured by Asahi Kasei Kogyo Co., Ltd .: 60 parts, adhesive Yasuhara Chemical Co., Ltd. hydrogenated terpene resin Clearon P150 (softening point 150 ° C., no acid value): 40 parts in a container and diluted with a mixed solvent of toluene / methyl ethyl ketone = 8/2 as the imparting agent (B) at 50 ° C. And stirred for 3 hours to obtain a solution of the main agent 14 (solid content 30%). In addition, the amount of the carboxyl group derived from the carboxyl group-containing amorphous polyolefin resin (A1) contained in a total of 1 g of the amorphous polyolefin resin (A1) and the tackifier (B) is 0.024 ( mmol).

<Curing agent 1>
As the aziridine group-containing compound (C), a trifunctional aziridine derivative Chemitite PZ-33 (amount of functional group of aziridine group 6.3 mmol / g) manufactured by Nippon Shokubai Co., Ltd. was used, and this was used as curing agent 1.

<Curing agent 2>
As an aziridine group-containing compound (C), a hexamethylene diisocyanate trimer Sumidur N3300 (a functional group amount of aziridine group 0 mmol / g, a functional group amount of isocyanate group 5.19 mmol / g) manufactured by Sumika Bayer Urethane Co., Ltd. This was used as curing agent 2.

<Reaction inhibitor 1>
As the tertiary amine (D), triethylamine (boiling point 90 ° C., tertiary amine amount 9.9 mmol / g) was used, and this was designated as reaction inhibitor 1.

<Reaction inhibitor 2>
As the tertiary amine (D), dimethylbenzylamine (boiling point 183 ° C., tertiary amine amount 7.4 mmol / g) was used, and this was used as the reaction inhibitor 2.

<Reaction inhibitor 3>
As the tertiary amine (D), tributylamine (boiling point 214 ° C., tertiary amine amount 5.4 mmol / g) was used, and this was designated as reaction inhibitor 3.

<Reaction inhibitor 4>
As the tertiary amine (D), trioctylamine (boiling point 366 ° C., amount of tertiary amine 2.8 mmol / g) was used, and this was used as the reaction inhibitor 4.

<Examples 1 to 10>, <Comparative Examples 1 to 8>
In order to obtain the aziridine / COOH ratio and amine / COOH ratio shown in Tables 1 and 2, various reaction inhibitors and curing agents were blended in order with respect to various main agent solutions, and diluted with toluene to adjust the solid content to 20%. The solution is used as an adhesive solution, and a laminate of an aluminum foil and an unstretched polypropylene film is obtained according to the method described later. The peel strength after 1 day at aging 40 ° C, the peel strength after 5 days at aging 40 ° C, and after these aging The peel strength after the laminate was immersed in the electrolyte for 7 days was determined. Moreover, the pot life was judged from the viscosity change of the adhesive 24 hours after mixing.
In addition, since the curing agent used in Comparative Example 7 does not contain an aziridine group but contains an isocyanate group, only in Comparative Example 7, the NCO / COOH ratio is a value described in the column of aziridine / COOH ratio in Table 2 Formulation was performed so that

  Abbreviations shown in Tables 1 and 2 are as follows.

<Carboxyl group-containing amorphous polyolefin resin (A1), carboxyl group-containing crystalline polyolefin resin (A1 ′)>
Tuftec M1911: Maleic acid-modified hydrogenated SBS (hydrogenated styrene-butadiene-styrene) manufactured by Asahi Kasei Kogyo Co., Ltd., styrene content: 30% by weight, acid value: 0.04 (mmol / g), solid at normal temperature Tuftec M1913 : Asahi Kasei Kogyo Co., Ltd. maleic acid-modified hydrogenated SBS (hydrogenated styrene-butadiene-styrene), styrene content: 30% by weight, acid value: 0.19 (mmol / g), solid at normal temperature ・ Tuftec M1943: Asahi Kasei Maleic acid-modified hydrogenated SBS (hydrogenated styrene-butadiene-styrene), manufactured by Co., Ltd. (styrene content 20% by weight, acid value 0.19 mmol / g, solid at room temperature)
Claprene LIR-403: Maleic acid modified liquid polyisoprene manufactured by Kuraray Co., Ltd., acid value: 0.18 (mmol / g), liquid at room temperature Claprene LIR-410: Half of maleic acid modified liquid polyisoprene manufactured by Kuraray Co., Ltd. Esterified product, acid value: 0.33 (mmol / g), liquid at normal temperature Supercron 892L: Nippon Paper Chemicals Co., Ltd. maleic acid-modified chlorinated polypropylene, acid value: 0.34 (mmol / g), at normal temperature Solid ・ Yumex 1010: Maleic acid-modified polypropylene manufactured by Sanyo Chemical Co., Ltd., acid value: 0.93 (mmol / g), solid at room temperature, crystalline

<Amorphous polyolefin resin having no carboxyl group (A2)>
-Tuftec H1053: Hydrogenated SBS (styrene-butadiene-styrene) manufactured by Asahi Kasei Kogyo Co., Ltd., styrene content: 67 wt%, solid at room temperature-Septon 2002: Hydrogenated SIS (styrene-isoprene-styrene) manufactured by Kuraray Co., Ltd., styrene Content: 30% by weight, solid at normal temperature Tuftec MP10: Partially hydrogenated SBS (styrene-butadiene-styrene) manufactured by Asahi Kasei Kogyo Co., Ltd., styrene content: 30% by weight, solid at normal temperature Claprene LIR-200: manufactured by Kuraray Co., Ltd. Hydrogenated polyisoprene, liquid at room temperature ・ Superclon C: Chlorinated polypropylene manufactured by Nippon Paper Chemical Co., Ltd., solid at room temperature

<Tackifier (B)>
Pine crystal KE-100: Rosin ester manufactured by Arakawa Chemical Industries, Ltd., softening point: 100 ° C., acid value: 0.11 (mmol / g)
Pine Crystal KR-50M: Rosin ester manufactured by Arakawa Chemical Industries, Ltd., softening point: 150 ° C., acid value: 1.7 (mmol / g)
Alcon P125: Hydrogenated C9 resin manufactured by Arakawa Chemical Industries, Ltd., softening point: 125 ° C., acid value: 0 (mmol / g)
Clearon P85: Hydrogenated terpene resin manufactured by Yasuhara Chemical Co., Ltd., softening point: 85 ° C., acid value: 0 (mmol / g)
Clearon P125: Hydrogenated terpene resin manufactured by Yasuhara Chemical Co., Ltd., softening point: 125 ° C., acid value: 0 (mmol / g)
Clearon P150: Hydrogenated terpene resin manufactured by Yasuhara Chemical Co., Ltd., softening point: 150 ° C., acid value: 0 (mmol / g)
Clearon M115: Aromatically modified hydrogenated terpene resin manufactured by Yasuhara Chemical Co., Ltd., softening point: 115 ° C., acid value: 0 (mmol / g)

<Aziridine group-containing compound (C) or polyisocyanate>
Chemitite PZ-33: a trifunctional aziridine derivative manufactured by Nippon Shokubai Co., Ltd., functional group amount of aziridine group: 6.3 (mmol / g)
Sumidur N3300: trimer of hexamethylene diisocyanate manufactured by Sumika Bayer Urethane Co., Ltd., functional group amount of aziridine group: 0 (mmol / g), functional group amount of isocyanate group: 5.19 (mmol / g)

<Tertiary amine (D)>
TEA: triethylamine, boiling point: 90 ° C., tertiary amine content: 9.9 (mmol / g)
DMBA: dimethylbenzylamine, boiling point: 183 ° C., tertiary amine content: 7.4 (mmol / g)
TBA: tributylamine, boiling point: 214 ° C., tertiary amine content: 5.4 (mmol / g)
TOA: trioctylamine, boiling point: 366 ° C., tertiary amine amount: 2.8 (mmol / g)

<Performance test>
[Pot life test]
The viscosity change of the adhesive solution 24 hours after preparing the adhesive solution was evaluated using a B-type viscometer. For the coatable sample, create an adhesive solution and use the adhesive solution for 24 hours to learn how to make the above aluminum foil / unstretched polypropylene laminate film, 40 ° C for 1 day and 40 ° C for 5 days Aged / AlPP laminated film was prepared. In these laminated films, the 25 ° C. peel test and the electrolytic solution test described above were performed, and evaluation was made according to the following criteria as to whether there was any deterioration in adhesive performance as compared to the case where the adhesive solution was used immediately after creation. went.
Excellent in practical use: No increase in viscosity and no deterioration in adhesive performance.
○ Practical area: There is thickening, but coating is possible. No deterioration of adhesive performance.
△ Practical lower limit: There is thickening, but coating is possible. Adhesive performance is slightly degraded.
× Not practical: There is significant thickening and coating is impossible. Or, coating is possible, but the adhesive performance is significantly degraded.

[Adhesive strength test]
(Preparation of aluminum foil / unstretched polypropylene laminate film)
The adhesives of Examples and Comparative Examples were applied to one side of an aluminum foil having a thickness of 50 μm with a bar coater, and dried at 100 ° C. for 1 minute (adhesive amount when dried: 2-3 g / m ² ). An unstretched polypropylene film (hereinafter referred to as CPP) having a thickness of 30 μm was superposed on the layer and passed between two rolls set at 60 ° C. to obtain a laminate. Thereafter, the obtained laminate was cured (aging) at 40 ° C. for 1 day and at 40 ° C. for 5 days. The aluminum foil / CPP laminate film thus obtained is hereinafter referred to as “Al / CPP laminate film”.

(25 ° C peeling test)
The Al / CPP laminated film aged at 40 ° C. for 1 day and the Al / CPP laminated film aged at 40 ° C. for 5 days were allowed to stand in an environment of 25 ° C. and 65% humidity for 6 hours, and then each 200 mm. Cut to a size of 15 mm, and perform a T-type peel test at a load rate of 300 mm / min under an environment of 25 ° C. and 65% humidity using a tensile tester in accordance with the test method of ASTM-D1876-61. It was. The peel strength (N / 15 mm width) between the aluminum foil / CPP is shown as an average value of five test pieces. Evaluation was made according to the following criteria.
◎ Excellent in practical use: 7N / 15mm or more ○ Practical range: 5-7N / 15mm
△ Practical lower limit: 2-5N / 15mm
× Not practical: Less than 2N / 15mm

(Peel test after immersion in electrolytic solution)
The Al / CPP laminated film aged at 40 ° C. for 1 day and the Al / CPP laminated film aged at 40 ° C. for 5 days were allowed to stand in an environment of 25 ° C. and 65% humidity for 2 weeks, and then each 200 mm The sample was cut into a size of 15 mm, and this test piece was dissolved in an electrolytic solution [lithium hexafluorophosphate dissolved in ethylene carbonate / diethyl carbonate / dimethyl carbonate = 1/1/1 (volume ratio). It was immersed for 7 days at 85 ° C. in a lithium fluorophosphate solution]. Thereafter, the test piece was taken out and washed with running water for about 10 minutes. After sufficiently wiping off the water with a paper wiper, the water was sufficiently dried.
The test piece thus obtained was subjected to a T-type peel test at a load rate of 300 mm / min in an environment of 25 ° C. and a humidity of 65% using a tensile tester in accordance with the test method of ASTM-D1876-61. . The peel strength (N / 15 mm width) between the aluminum foil / CPP is shown as an average value of five test pieces. The evaluation criteria are the same as in the 25 ° C. peel test. The evaluation results of the obtained laminated film are shown in Tables 3-4.

  As shown in Table 4, the adhesive of Comparative Example 1 does not contain the carboxyl group-containing amorphous polyolefin resin (A1), lacks adhesiveness with the aluminum interface, and has a crosslinked structure with the aziridine group-containing compound. As a result, the adhesive strength and the electrolyte resistance were remarkably lowered.

  The adhesive of Comparative Example 2 contains a polyolefin resin having a carboxyl group. However, since the polyolefin resin has crystallinity, it has poor solubility in a solvent, and undissolved components are precipitated in the solution. The coating could not be performed and the test could not be carried out.

  Since the adhesive of Comparative Example 3 did not contain the tackifier (B), the elasticity of the adhesive was insufficient and sufficient adhesive strength could not be obtained.

  Since the adhesive of Comparative Example 4 contains an excessive amount of the aziridine group-containing compound (C) as compared with the carboxyl group of the carboxyl group-containing amorphous polyolefin resin (A1) and the tackifier (B), The reaction aziridine group-containing compound (C) deteriorated the viscoelasticity of the adhesive and significantly deteriorated the adhesive strength and the electrolyte resistance.

  Since the adhesive of Comparative Example 5 does not contain the aziridine group-containing compound (C), the crosslinked structure formed by the reaction of the carboxyl group-containing amorphous polyolefin resin (A) and the aziridine group-containing compound (C) In addition, the electrolytic solution resistance was remarkably deteriorated.

  Since the adhesive of Comparative Example 6 used polyisocyanate instead of the aziridine group-containing compound (C), the crosslinking reaction with the carboxyl group-containing amorphous polyolefin resin (A1) was sufficiently achieved by aging at 40 ° C. for 1 day. It was not possible to proceed, and sufficient adhesive strength and electrolytic solution resistance could not be obtained by such short-time aging. In addition, since the crosslinking reaction progresses with time during the coating of the adhesive, there was a large increase in the viscosity of the adhesive 24 hours after compounding, and the coating was impossible.

  Since the tertiary amine (D) is not blended in the adhesive of Comparative Example 7, the carboxyl group-containing amorphous polyolefin resin (A1) and the aziridine group-containing compound (C ) Progressed too quickly, resulting in poor coating appearance such as bar coater streaks in the coating film, and a decrease in leveling properties, resulting in a decrease in adhesive strength. In addition, since the crosslinking reaction progresses over time during the adhesive coating, there was a large increase in the viscosity of the adhesive 24 hours after compounding, and the coating was impossible.

  In the adhesive of Comparative Example 8, the tertiary amine (D) had a boiling point of 366 ° C., and the tertiary amine (D) having a boiling point outside the preferred range of 70 to 300 ° C. was used. Since the tertiary amine (D) is not sufficiently volatilized, the reaction between the carboxyl group-containing amorphous polyolefin resin (A) and the aziridine group-containing compound (C) does not proceed sufficiently, and an excessive amount remains in the coating film. The viscoelasticity of the adhesive was deteriorated by the tertiary amine (D), and the adhesive strength and the electrolytic solution resistance were remarkably deteriorated.

  On the other hand, the adhesives of Examples 1 to 10 shown in Table 3 have a carboxyl group-containing amorphous polyolefin resin (A) having an acid value of 0.005 to 0.75 mmol / g and a non-crystalline carboxyl group. Non-crystalline polyolefin resin, tackifier having a softening point of 60 to 160 ° C. and acid value of 0 to 3.0 mmol / g as tackifier (B), and aziridine per molecule as aziridine group-containing compound (C) As an aziridine group-containing compound having a number of groups of 1.5 or more, a tertiary amine (D) is a tertiary amine (D) having volatility at room temperature and having a boiling point in the range of 70 ° C to 370 ° C. Since they are contained in suitable amounts, the adhesive strength and electrolyte resistance are all well balanced in an Al / CPP laminated film that has been aged at 40 ° C. for 1 day and aged at 40 ° C. for 5 days. And it has had a long-term pot life.

The adhesives of Examples 2, 5, 9, and 10 do not contain the amorphous polyolefin resin (A2) that does not have a carboxyl group that is solid at room temperature, or are liquid at room temperature as compared with the above (A2). A large amount of the carboxyl group-containing amorphous polyolefin resin (A1) is blended. Therefore, since the adhesive has excellent wettability, the adhesive strength comparable to that in the case of aging at 40 ° C. for 5 days can be expressed by aging for a short time of 1 day at 40 ° C.
On the other hand, both of the carboxyl group-containing amorphous polyolefin resin (A1) and the non-carboxylized amorphous polyolefin resin (A2) of Examples 1, 3, 4, 6, 7, and 8 are solid at room temperature. Although the adhesive is inferior to the adhesives of Examples 2, 5, 9, and 10 in terms of wettability, it is excellent in the elasticity of the adhesive. Therefore, by aging at 40 ° C. for 5 days, It was possible to develop a higher adhesion than in the case of aging for a short period of one day.

  In Examples 2, 5, 9, and 10 where the wettability of the adhesive is excellent, it can be seen that the adhesive strength tends to be improved after the electrolytic solution test compared to the adhesive strength of the 25 ° C. peel test under any aging condition. It was. This is considered to be because the double bond in the structure of the carboxyl group-containing amorphous polyolefin resin (A) reacts during the electrolytic solution test to form a crosslinked structure, thereby improving the elasticity of the adhesive.

  On the other hand, in the case of Examples 1, 3, 4, 6, 7, and 8 where the elasticity of the adhesive is excellent, the electrolyte resistance test compared to the adhesive strength of the 25 ° C. peel test under the aging conditions at 40 ° C. for 1 day Later, there was a tendency for adhesion to improve. The reason for this is considered to be that the wettability of the adhesive to the base material is improved by applying heat to the adhesive during the electrolytic solution test.

Among these adhesives of Examples, the adhesives of Examples 6, 8, and 10 showed high performance in all tests.
In the adhesives of Examples 6, 8, and 10, the content of the carboxyl group-containing amorphous polyolefin resin (A) is in a preferred range of 30 to 70% by weight, and the content of the tackifier (B) is 20 Since it was a suitable range of -70%, the balance of the viscoelasticity of the adhesive was excellent, and the adhesive strength was good as compared with the adhesives of Examples 1 and 2 outside the preferred range.
Further, in the adhesives of Examples 6, 8, and 10, the amount of the carboxyl group derived from the carboxyl group-containing amorphous polyolefin resin (A) was 0 with respect to 1 mol of the carboxyl group derived from the tackifier (B). Since it was a preferred range of ˜4.5 mol, it was formed by the reaction of the carboxyl group non-crystalline polyolefin resin (A) and the aziridine group-containing compound (C) as compared with the adhesive of Example 3 outside the preferred range. The cross-linked structure and the cross-linked structure formed by the reaction of the carboxyl group of the tackifier (B) and the aziridine group-containing compound (C) were in an optimal balance, and the adhesive strength and electrolyte resistance were good.
Moreover, since the aziridine group-containing compound is blended at a suitable blending ratio of aziridine / COOH = 0.5 to 6.0 / 1 in the adhesives of Examples 6, 8, and 10, the Examples 4, 5 Compared with the adhesive of No. 1, the adhesive strength and the electrolytic solution resistance were excellent.
Moreover, since the adhesives of Examples 6, 8, and 10 are blended with hydrogenated petroleum resin as a tackifier (B), compared with Examples 7 and 9 that are not blended with hydrogenated petroleum resin, The adhesiveness to the CPP substrate was excellent, and the adhesive strength was excellent.

If the adhesive of this invention is used, a polyolefin resin and a metal can be adhere | attached with high intensity | strength, and the laminated body excellent in chemical resistance can be obtained. Utilizing these characteristics, the use of the adhesive of the present invention makes it possible to form polyolefin resin / non-electrolyte secondary battery soft packs with excellent adhesion strength between polyolefin resin / metal and resistance to electrolyte. can do.
The soft pack for a non-aqueous electrolyte secondary battery using the adhesive of the present invention can contribute to safety and life extension of the non-aqueous electrolyte secondary battery. Such a high quality non-aqueous electrolyte secondary battery leads to the spread of non-aqueous electrolyte secondary batteries, and contributes to environmental conservation from the viewpoint of high-efficiency use of energy as a new energy material.

  In addition, the adhesive composition according to the present invention is a polyolefin-based resin that requires high adhesive strength and chemical resistance in various industrial fields such as architecture, medical care, and automobiles, in addition to soft packs for non-aqueous electrolyte secondary batteries. Suitable as an adhesive for the materials used.

Claims (7)

An adhesive composition containing the following (A) to (D),
In a total of 100% by weight of the amorphous polyolefin resin (A) containing the amorphous polyolefin resin (A1) having a carboxyl group and the tackifier (B), the carboxyl group-containing amorphous polyolefin resin (A1 20 to 90% by weight, and 10 to 80% by weight of the tackifier (B),
The amount of carboxyl groups derived from the carboxyl group-containing amorphous polyolefin resin (A1) contained in a total of 1 g of the amorphous polyolefin resin (A) and the tackifier (B) is 0.001 to 0.00. 675 (mmol),
The aziridine group-containing compound (C) is contained in a range where the amount of the aziridine group is 0.3 to 10 mol with respect to a total of 1 mol of the carboxyl groups,
An adhesive composition containing 0.5 mol or more of tertiary amine (D) having a boiling point of 70 to 300 ° C. with respect to 1 mol of the total of the carboxyl groups.   The adhesive composition according to claim 1, wherein the tackifier (B) is a hydrogenated petroleum resin. A laminate in which a metal foil and a heat-fusible film are laminated via an adhesive layer,
A laminate in which the adhesive layer is an adhesive layer formed from the adhesive composition according to claim 1 or 2.   The laminate according to claim 3, wherein another sheet-like member is further laminated on the metal foil side. On one side of the metal foil or heat-fusible film,
Applying the adhesive composition according to claim 1 or 2 to form an uncured adhesive layer,
On the surface of the uncured adhesive layer, a heat-sealable film or a metal foil is overlaid,
A method for producing a laminate of a metal foil and a heat-fusible film, wherein the uncured adhesive layer is cured and the metal foil and the heat-fusible film are bonded together. A secondary battery comprising 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,
The battery container is a laminate in which a metal foil and a heat-fusible film are laminated via an adhesive layer, and the heat-fusible film is in contact with the electrolyte,
The battery main body, the plurality of terminals, and the electrolyte are connected to the battery container in a state where the other ends of the plurality of terminals protrude from the battery container by heat fusion of a part of the heat-fusible film. Sealed inside,
A secondary battery, wherein the adhesive layer is an adhesive layer formed from the adhesive composition according to claim 1.   The secondary battery according to claim 6, wherein the laminate forming the battery container is a laminate further comprising another sheet-like member on the metal foil side.