JP5900680B1 - Adhesive composition, laminate, storage device packaging, storage device container, and storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive composition capable of forming a laminate capable of maintaining a high adhesive strength even when immersed in an electrolyte solution at 85 ° C. for 2 weeks or more in the case of aging at 40 ° C. for about 3 days. The provision of a packaging material for an electricity storage device, a container for an electricity storage device, and an electricity storage device that have better electrolyte resistance than before. The present invention relates to a reaction between a polyolefin resin (A) having a carboxyl group or an acid anhydride group, a polymer (B1) of an unsaturated fatty acid, and a compound (B2) having two or more epoxy groups. An adhesive composition comprising the resulting epoxy compound (B). [Selection figure] None

Description

  The present invention relates to an adhesive composition. Moreover, this invention relates to the laminated body which laminated | stacked the metal foil layer and the heat seal layer using the said adhesive composition, and the packaging material for electrical storage devices. Furthermore, the present invention relates to a power storage device container obtained by processing the power storage device packaging material so that the heat seal layer is an inner surface, and a power storage device using the power storage device container.

A secondary battery is a typical power storage device. Due to the rapid growth of electronic devices such as mobile phones and portable personal computers, the demand for secondary batteries such as lightweight and small lithium-ion batteries has increased. Conventionally, metal cans have been used as outer bodies of secondary batteries, but packaging materials in which plastic films, metal foils, and the like are laminated are becoming mainstream from the viewpoints of weight reduction and productivity.
As the simplest packaging material, a laminate composed of a resin film layer (11), a metal foil layer (12), an adhesive layer (13) and a heat seal layer (14) in order from the outer layer side as shown in FIG. It is done. As shown in FIG. 2, the container for an electricity storage device is formed by molding the packaging material so that the resin film layer (11) forms a convex surface and the heat seal layer (14) forms a concave surface (deep drawing molding process, overhanging). Molding process, etc.). And the battery is manufactured by enclosing and sealing an electrode, electrolyte solution, etc. in the concave surface side of the container for electrical storage devices.
Capacitors are also one type of power-discharging devices. Among them, lithium ion capacitors are an area in which market growth is expected in the future.

  Patent Document 1 (Patent 3184725) includes (A) a polyolefin-based resin having at least one functional group selected from the group consisting of an acid anhydride group, a carboxyl group, and a carboxylic acid metal salt, and (B) an epoxy group. An adhesive resin composition containing two or more epoxidized vegetable oils having a molecular weight of 3000 or less in a specific ratio is disclosed.

  Patent Document 2 (Japanese Patent Application Laid-Open No. 2012-216364) discloses an acid-modified polypropylene resin containing 70% by mass or more of a propylene component and 0.1 to 10% by mass of an acid component, and at least of an oxazoline compound and an epoxy compound. A battery exterior body having an adhesive layer containing a cross-linking agent containing one at a specific ratio is disclosed.

  Patent Document 3 (Japanese Patent Laid-Open No. 2013-91702) discloses an acid-modified polyolefin resin (A) and an epoxy resin having two or more epoxy groups in one molecule and ten or more hydroxyl groups in one molecule. An adhesive resin composition containing a compound (B) is disclosed.

  Patent Document 4 (WO2014 / 050686) contains a polyolefin resin (A) having a hydroxyl group and / or an acid group, a phosphoric acid-modified compound (B), and an epoxy resin (C) having an epoxy equivalent of 160 to 1000. An adhesive composition for laminating is disclosed (claim 4). And the application to the laminated body for secondary batteries is disclosed (Claim 9).

Japanese Patent No. 3184725 JP 2012-216364 A JP2013-91702A WO2014 / 050686 brochure

The following performance is mainly required for the adhesive layer for bonding the metal foil layer and the heat seal layer among the packaging materials for the electricity storage device.
(1) The adhesive strength between the metal foil layer and the heat seal layer is large.
(2) The adhesive layer has electrolyte resistance. That is, the adhesive strength between the metal foil and the heat seal layer 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 (electrolyte) 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 container for the electricity storage device, the electrolyte solution passes through the heat seal layer, reaches the adhesive layer, and causes a decrease in the adhesive strength between the heat seal layer 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 seal layer and the adhesive layer, reaches the metal foil, and corrodes the metal foil. This corrosion significantly reduces the adhesive strength between the heat seal layer and the metal foil.
Therefore, the adhesive layer that bonds the heat seal layer and the metal foil layer is required to have resistance to a substance that is generated when an intruder from the outside of the electricity storage device acts on the electrolyte in addition to resistance to the electrolyte itself.
Incidentally, in recent years, with the expansion of applications such as in-vehicle and household power storage, power storage devices have been required to have a large capacity and long-term durability. Therefore, more excellent electrolyte resistance is required particularly for in-vehicle applications.

In Patent Document 1, the adhesive resin composition is melt-extruded on a polyester film or a polyamide film, and the adhesive strength between each film and the adhesive resin composition layer is a constant temperature at a temperature of 60 ° C. and a relative humidity of 90%. It is stated that it can be maintained to some extent even after being left in the tank for 48 hours. However, Patent Document 1 does not disclose or suggest a battery packaging material. The moisture resistance and electrolyte resistance of the adhesive strength as described above are completely different.
Patent Document 2 discloses a battery exterior material as described above. However, its electrolyte resistance is only about 24 hours at 85 ° C. or 100 ° C.
Patent Document 3 does not disclose or suggest a battery packaging material. And although the initial adhesive strength is described, there is no mention of the durability of the adhesive strength. Of course, no word for electrolyte resistance has been suggested.
Patent Document 4 discloses application to a laminate for a secondary battery as described above, and refers to “electrolytic resistance”. However, the “electrolyte resistance” is merely a level of immersion in a solvent (ethylene carbonate, propyl carbonate) not containing an electrolyte such as a lithium salt at 40 ° C. for 30 days. That is, “electrolyte resistance” in the cited document 4 is merely solvent resistance. Resistance to an electrolyte solution containing an electrolyte is completely different from mere solvent resistance.

The present invention has been made in view of the above background, and in the case of a shorter aging time, an adhesive composition capable of forming a laminate capable of maintaining a high level of adhesive strength even when immersed in a high-temperature electrolyte solution for a long period of time. It is an issue to provide. Moreover, this invention makes it a subject to provide the packaging material for electrical storage devices, the container for electrical storage devices, and an electrical storage device which are more excellent in electrolyte tolerance than before.
Specifically, it is an object to ensure an electrolyte resistance of 85 ° C. for 2 weeks or more even after aging at 40 ° C. for about 3 days.

The present inventor found that the epoxy compound (B) obtained by the reaction of the unsaturated fatty acid polymer (B1) and the compound (B2) having two or more epoxy groups is excellent in compatibility with the polyolefin and has a curing reaction. The present invention has been completed.
That is, the present invention is obtained by a reaction between a polyolefin resin (A) having a carboxyl group or an acid anhydride group, a polymer (B1) of an unsaturated fatty acid, and a compound (B2) having two or more epoxy groups. The present invention relates to an adhesive composition comprising an epoxy compound (B).

The epoxy compound (B) is an epoxy compound obtained by further hydrogenating a reaction product of a polymer (B1) of an unsaturated fatty acid and a compound (B2) having two or more epoxy groups. Is preferred.
The polymer (B1) of the unsaturated fatty acid is preferably a compound (dimer acid) or a compound (trimer acid) obtained by dimerizing an unsaturated fatty acid having 12 to 24 carbon atoms.
The compound (B2) having two or more epoxy groups is preferably selected from a bisphenol A type epoxy compound or a bisphenol F type epoxy compound.
It is preferable that the epoxy equivalent of the said epoxy compound (B) is 200-7000.

The polyolefin resin (A) preferably has a mass average molecular weight of 50,000 to 500,000.
The polyolefin resin (A) is preferably obtained by further acid-modifying a copolymer obtained from 1-butene and another olefin.

In the adhesive composition of the present invention, when the content of carboxyl groups per 1 g of the polyolefin resin (A) is X (mmol) and the content of acid anhydride groups is Y (mmol), X + 2Y Is preferably 0.05 to 0.6.
When the content of the polyolefin resin (A) is P (g) and the epoxy group in the epoxy resin (B) is Z (mmol), the adhesive composition of the present invention is Z / [(X + 2Y). P] is preferably 0.3 to 10.

  Moreover, this invention relates to the laminated body by which a metal foil layer and a heat seal layer are laminated | stacked through the adhesive bond layer formed from the said adhesive composition.

  Furthermore, the present invention is an electricity storage device packaging material in which a resin film layer, a metal foil layer, an adhesive layer, and a heat seal layer are essential from the outer layer, and the adhesive layer is formed from the adhesive composition. The present invention relates to a packaging material for an electricity storage device.

The present invention also relates to a container for an electricity storage device formed from the packaging material for an electricity storage device, wherein a heat seal layer constitutes the inner surface.
Furthermore, this invention relates to the electrical storage device formed using the said container for electrical storage devices.

  With the adhesive composition of the present invention, in the case of aging at 40 ° C. for about 3 days, it is possible to form a laminate capable of maintaining the adhesive strength at a high level even when immersed in an electrolyte solution at 85 ° C. for 2 weeks or more.

It is typical sectional drawing of the one aspect | mode of the packaging material for electrical storage devices of this invention. It is a typical perspective view of one mode (tray form) of the container for electrical storage devices of the present invention.

Hereinafter, embodiments of the present invention will be described in detail. In the present specification, the description “arbitrary number A to arbitrary number B” means a range larger than the number A and the number A and smaller than the number B and the number B.
As shown in FIG. 1, the packaging material for an electricity storage device of the present invention is formed by laminating a resin film layer (11), a metal foil layer (12), an adhesive layer (13), and a heat seal layer (14) in this order. Is. The adhesive layer (13) plays a role of laminating (bonding) the metal foil layer (12) and the heat seal layer (14).

The container for an electricity storage device of the present invention is formed using the packaging material for an electricity storage device of the present invention, and the form thereof is not particularly limited. A preferred example is a tray-like one as shown in FIG. In this example, the heat seal layer (14) is disposed inside the tray, that is, on the concave side forming a space for accommodating an electrode, an electrolyte, and the like, and the outer layer side resin film layer on the outside of the tray, that is, on the convex side. (11) is arranged. In addition to the tray shape, a cylindrical shape (cylinder, square tube, elliptical tube, etc.) can be exemplified. These electric storage device containers are usually obtained by molding a flat storage device for an electric storage device. The inside of the electricity storage device container, that is, the surface in contact with the electrolytic solution or the like is a heat seal layer (14). The heat seal layer (14) of the flange portion and the heat seal layer (14) constituting another energy storage device packaging material or the heat seal layer (14) of the flange portion of another energy storage device container are opposed to and in contact with each other. By heating, the heat seal layers (14) are fused together, and an electricity storage device member such as an electrolytic solution or an electrode is enclosed.
The container for an electricity storage device of the present invention includes a bag-like container (pouch type) in addition to a tray shape.

The adhesive composition of this invention is used suitably for formation of an adhesive bond layer (13).
The adhesive composition of the present invention contains a polyolefin resin (A) having a carboxyl group or an acid anhydride group and an epoxy compound (B) modified with a polymer of an unsaturated fatty acid. A polyolefin resin (A) having a carboxyl group or an acid anhydride group is simply abbreviated as a polyolefin resin (A), and is reacted with a polymer (B1) of an unsaturated fatty acid and a compound (B2) having two or more epoxy groups. The resulting epoxy compound (B) may simply be abbreviated as epoxy compound (B).
In a state where the adhesive composition of the present invention is sandwiched between the metal foil layer (12) and the heat seal layer (14), a carboxyl group or an acid anhydride group in the polyolefin resin (A) and an epoxy compound ( By reacting with the epoxy group in B), a strong cross-linked structure can be formed, sufficient adhesive strength can be expressed, and the adhesive strength can be maintained at a high level even when immersed in a higher temperature electrolyte solution for a long period of time. .

<Polyolefin resin (A) having carboxyl group or acid anhydride group>
The polyolefin resin (A) has non-crystallinity because it is soluble in the solvent used in the adhesive composition and can be stably stored without precipitation of the dissolved solution (having storage stability). preferable. On the other hand, in order to improve the electrolyte resistance as an adhesive layer in the laminate, it is preferable to have a crystalline part, and the balance is important. The polyolefin resin (A) used in the present invention has a mass average molecular weight of 50,000 to 500,000, a melting point of 60 to 110 ° C., and a melting energy (ΔE) of 15 to 50 (mJ / mg).
) Is preferable.

Since the polyolefin resin (A) has a mass average molecular weight (Mw) of 50,000 to 500,000, the storage stability as a solution of the polyolefin resin (A) constituting the adhesive composition, and a packaging material for an electricity storage device As a result, it is easy to achieve both electrolyte resistance, heat sealability, and coatability. More preferably, Mw of polyolefin resin (A) is 100,000-400,000.
In other words, if the Mw of the polyolefin resin (A) is less than 50,000, the polymer chain of the polyolefin resin (A) is insufficiently entangled, so that the film strength of the adhesive layer is lowered and the electrolyte resistance may be insufficient. On the other hand, if Mw is larger than 500,000, the storage stability at 25 ° C. as the polyolefin resin (A) solution may be lowered, or the viscosity of the adhesive solution may be too high to deteriorate the coatability.

The polyolefin resin (A) has a melting point of 60 to 110 ° C. and a melting energy (ΔE) of 15 to 50 (m).
J / mg), the adhesive strength (initial, after immersion in the electrolyte solution) and heat sealability as a packaging material for an electricity storage device can be satisfied in a well-balanced manner.
In other words, when the melting point of the polyolefin resin (A) is less than 60 ° C., the adhesive strength and the heat sealability after immersion in the electrolyte may be lowered. If the melting point is higher than 110 ° C., the adhesive strength (initially, after immersion in the electrolytic solution) may be reduced. More preferably, the melting point of the polyolefin resin (A) is 60 to 90 ° C.
Further, when the melting energy (ΔE) of the polyolefin resin (A) is less than 15 (mJ / mg), the adhesive strength and heat sealability after immersion in the electrolyte are lowered, and when it is higher than 50 (mJ / mg), the crystallinity. The storage stability as a polyolefin resin (A) solution may decrease. More preferably, the melting energy (ΔE) of the polyolefin resin (A) is 20 to 50 (mJ / mg), and more preferably 20 to 40 (mJ / mg).

Here, the heat sealability will be described.
In addition to the two performances (high adhesion strength and excellent electrolyte resistance) described at the beginning of the section [Problems to be Solved], the power storage device packaging material also has excellent heat sealability. Desired.
As described above, the heat seal layer (14) constituting the packaging material for the electricity storage device is fused with the heat seal layer (14) by heat, and an electricity storage device member such as an electrolyte solution or an electrode in the electricity storage device container. Responsible for the function of sealing. From the viewpoint of securing a large heat seal strength (peel strength between heat seal layers (14)), it is considered that heat seal at high temperature and high pressure is preferable.
However, when the adhesive layer (13) that has bonded the heat seal layer (14) and the metal foil layer (12) melts or deforms due to heat and pressure during heat sealing, the electrode terminal and the metal foil There is a possibility that the layer (12) is electrically connected. When conducting, it does not function as an electricity storage device. Therefore, it is required that the adhesive layer (13) is not melted or deformed by heat and pressure during heat sealing so that the insulation between the electrode terminal and the metal foil layer (13) is not impaired by heat sealing. It is done.
By using the polyolefin resin (A) having a melting point and melting energy (ΔE) within the above ranges, melting and deformation of the adhesive layer (13) during heat sealing can be effectively suppressed / prevented.

  In the present invention, “storage stability” means that 10 g of resin is added to 90 g of toluene, the resin is heated and dissolved to obtain a transparent solution, and then cooled to 25 ° C. for one week at the same temperature. A thing that does not cause precipitation upon standing.

The polyolefin resin (A) in the present invention only needs to have a carboxyl group or an acid anhydride group. For example, the polyolefin resin (A1) not having a carboxyl group or an acid anhydride group may have an ethylenically unsaturated carboxyl group. Examples thereof include a modified polyolefin resin obtained by graft polymerization of a group or its acid anhydride, and a copolymer of an olefin monomer and an ethylenically unsaturated carboxylic acid or its acid anhydride. Moreover, the polyolefin which has a carboxyl group can also be obtained by making it react with the acid anhydride group of polyolefin which has an acid anhydride group, and water or alcohol. A modified polyolefin resin obtained by graft-polymerizing an ethylenically unsaturated carboxyl group or an acid anhydride thereof to a polyolefin (A1) having no carboxyl group or acid anhydride group is preferred. The polyolefin resin (A) may be used alone or in combination of two or more.
The amount of the carboxyl group or acid anhydride group in the polyolefin resin (A) will be described later.

The method for graft polymerization of polyolefin is not particularly limited. For example, the method disclosed in JP-A-11-293216 can be used.
Although it does not specifically limit as said polyolefin resin (A1), For example, the homopolymer of olefin monomers, such as ethylene, propylene, 1-butene, butadiene, isoprene, 1-hexene, 1-octene, olefin monomer It refers to a polymer mainly composed of a hydrocarbon skeleton, such as a copolymer of each other, a copolymer with other monomers, and a hydride or halide of the obtained polymer. A copolymer of olefin monomers is preferred.

  As a copolymer of olefin monomers, a copolymer of 1-butene and another olefin monomer is preferable. Other olefins are preferably ethylene and propylene, and copolymers of 1-butene and other olefin monomers are binary copolymers of ethylene and 1-butene, binary of propylene and 1-butene. Examples of the copolymer include a terpolymer of ethylene, propylene and 1-butene, and a binary copolymer of propylene and 1-butene is more preferable. The copolymerization ratio is preferably propylene: 1-butene = 10: 90 to 80:20 (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 60 ° C. when propylene is less than 10 mol%, and the melting point may be higher than 110 ° C. when more than 80 mol%.

Other monomers that may be copolymerized with the olefin monomer are not particularly limited, for example,
Aromatic vinyl compounds such as styrene, α-methylstyrene, and indene;
Methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, Alkyl (meth) acrylate compounds such as behenyl (meth) acrylate;
(Meth) acrylate compounds having an alicyclic structure such as cyclohexyl (meth) acrylate and isobornyl (meth) acrylate;
(Meth) acrylate compounds having an aromatic ring such as benzyl (meth) acrylate;
Hydroxyl group-containing (meth) acrylate compounds such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate;
(Meth) acrylate compounds having an amino group such as dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, t-butylaminoethyl (meth) acrylate;
Acrylamides such as (meth) acrylamide, dimethyl (meth) acrylamide, dimethylaminopropyl (meth) acrylamide, isopropyl (meth) acrylamide, diethyl (meth) acrylamide, hydroxyethyl (meth) acrylamide;
(Meth) acrylonitrile, acryloylmorpholine, etc. are mentioned.
Styrene, dodecyl (meth) acrylate, and stearyl (meth) acrylate are preferable from the viewpoint of graft polymerization and compatibility with polyolefin.
The ethylenically unsaturated carboxylic acid is not particularly limited, and examples thereof include acrylic acid, methacrylic acid, maleic acid, fumaric acid, crotonic acid, and itaconic acid. These ethylenically unsaturated carboxylic acids or acid anhydrides thereof may be used alone or in combination of two or more.

  The polymerization method of the olefin monomer is not particularly limited. For example, a metal catalyst such as a Ziegler-Natta catalyst or a metallocene catalyst such as the method disclosed in Japanese Patent Publication No. 07-080948, or (methyl) aluminoxane as necessary. A cocatalyst can be added to polymerize.

In addition, Mw of polyolefin resin (A) is calculated | required as follows.
The measurement was carried out with a column temperature of 40 ° C., tetrahydrofuran as an eluent, and a flow rate of 0.35 ml per minute, using an HLC-8220GPC system manufactured by Tosoh Corporation, in which two TSKgel superHZM-N columns were connected. A sample was prepared by dissolving 2 mg of polyolefin resin (A) in 5 ml of tetrahydrofuran. Mw was calculated in terms of standard polystyrene.
When two or more types of polyolefin resins (A) are used in combination, it means the mass average molecular weight of the entire mixture.

The melting point and melting energy (ΔE) can be determined by DSC measurement according to JIS K7121. Specifically, it is obtained as follows.
When the diameter or each side of the polyolefin resin (A) of about 10 mg is 0.5 mm or less, it is used as it is, and if it exceeds 0.5 mm, it is cut into 0.5 mm or less and put into a container.
Heat to about 30 ° C above the melting point at 10 ° C per minute and then cool to about 50 ° C below Tg at 10 ° C per minute. If no clear Tg is observed, cool to about 50 ° C. below the melting point. Then, it calculated | required from the peak top of the peak corresponding to the melting which appears when it heated to about 30 degreeC higher than melting | fusing point at 10 degreeC per minute. Further, ΔE is obtained from the area of the portion from when the peak corresponding to melting is separated from the baseline until it returns to the baseline again.
When two or more polyolefin resins (A) are used in combination, the melting point is determined from the peak top of the peak on the high temperature side, and ΔE is calculated from the sum of all peak areas obtained by melting.

  Commercially available products can also be used as the polyolefin resin (A). For example, Sumifit CK1D (trade name, manufactured by Sumitomo Chemical Co., Ltd.), Unistor P-401, P-802, P-902 (trade name) Umex 1001, 1010, 2000 (trade name, manufactured by Sanyo Chemical Co., Ltd.), Auroren 350S, 351S, 359S, S-5247S, S-5248S, S-5297S, S-5349S, S-5350S, and the like.

  In the present invention, in addition to the polyolefin resin (A) having a carboxyl group or an acid anhydride group, a polyolefin resin not having a carboxyl group or an acid anhydride group may be used in combination as long as the effects of the invention are not impaired. .

  Examples of the polyolefin resin having no carboxyl group or acid anhydride group used in the present invention include Tough selenium T3712, T3722, T3522 (propylene elastomer), Sumitomo Noblen (polypropylene), Mitsui Chemicals, manufactured by Sumitomo Chemical Co., Ltd. Tuffmer DF & A, Tuffmer H, Tuffmer XM, Tuffmer BL, Tuffmer M (α-olefin copolymer), Kuraray LIR-30 (isoprene polymer), LIR-200 (hydrogenated isoprene polymer) manufactured by Kuraray Co., Ltd. LBR-300 (butadiene polymer), Kuraray Co., Ltd. Septon 2002, 2004 (above, hydrogenated styrene-isoprene-styrene copolymer), 2104, 4033, HG252 (above, hydrogenated styrene-isoprene / butadiene- Styrene copolymer) Asaprene T-432 and T-437 manufactured by Asahi Kasei Chemicals Co., Ltd., Clayton D1155 manufactured by Kraton Polymer Japan Co., Ltd. (Partially hydrogenated styrene-butadiene-styrene copolymer), H1052, H1043 (above, hydrogenated styrene-butadiene-styrene copolymer), Nippon Paper Chemicals Co., Ltd. Supercron C (chlorinated product of propylene polymer), Lexpearl EMA (ethylene-methyl acrylate copolymer) manufactured by Nippon Polyethylene Co., Ltd., Lexpearl EEA (ethylene-ethyl acrylate copolymer), Everflex (ethylene-vinyl acetate copolymer) manufactured by Mitsui DuPont Polychemical Co., Ltd. Polymer), Sumitomo Chemical Co., Ltd. bond first (ethylene-glycidyl methacrylate copolymer), and the like. These may be used alone or in any combination of two or more.

Next, the epoxy compound (B) obtained by the reaction of the unsaturated fatty acid polymer (B1) used in the present invention with the compound (B2) having two or more epoxy groups will be described.
Due to the strong cross-linked structure obtained by reacting the epoxy group in the epoxy compound (B) with the carboxyl group or acid anhydride group in the polyolefin resin (A), sufficient adhesive strength can be expressed, and the electrolyte has a higher temperature. Even if it is immersed in the solution for a long time, its adhesive strength can be maintained at a high level.

The epoxy compound (B) used in the present invention is not limited to the following, but is a compound having a carboxyl group in an unsaturated fatty acid polymer (B1) and two or more epoxy groups ( Examples thereof include a resin obtained by an esterification reaction with an epoxy group in B2) or a hydrogenated compound thereof.
By using the epoxy compound (B) modified with the unsaturated fatty acid polymer (B1), the compatibility with the polyolefin resin (A) is remarkably improved, and the carboxyl group or acid anhydride in the polyolefin resin (A) The reaction with the group is promoted, and the productivity can be improved.

Examples of the unsaturated fatty acid polymer (B1) include dimers, trimers and oligomers of tetramers or more of unsaturated fatty acids, dimers (dimer acids), trimers (trimers). Acid) is preferred, and a mixture of both may be used.
Examples of unsaturated fatty acids include fatty acids having one unsaturated group such as oleic acid, elaidic acid, vaccenic acid, ricinolenic acid, gadoleic acid, eicosenoic acid, erucic acid, nervonic acid;
Fatty acids having two unsaturated groups such as linoleic acid, icosadienoic acid, docosadienoic acid;
Fatty acids having three unsaturated groups such as icosatrienoic acid, eleostearic acid, dihomo-γ-linolenic acid, pinolenic acid, mead acid, linolenic acid;
Examples include fatty acids having four unsaturated groups such as stearidonic acid, adachidonic acid, eicosatetraenoic acid, and adrenic acid.
Examples of commercially available products of these polymerized fatty acids include “Pripol 1004”, “Plipol 1006”, “Plipol 1009”, “Plipol 1013”, “Plipol 1015”, “Plipol 1017”, and “Plipol 1022” manufactured by Croda Japan. , “Prepole 1025”, “Prepole 1040”, “Empole 1008”, “Empole 1012”, “Empole 1016”, “Empole 1026”, “Empole 1028”, “Empole 1043”, “Empole 1061” manufactured by BASF Japan And “Empole 1062”.
Among these, unsaturated fatty acids having 12 to 24 carbon atoms, which have good compatibility with the polyolefin resin (A) and are easily obtained industrially, are preferable.

The compound (B2) having two or more epoxy groups may be a compound having two or more epoxy groups in one molecule. For example, as a commercial product, for example, trade name “Epicoat” manufactured by Mitsubishi Chemical Corporation 828 ”,“ Epicoat 834 ”,“ Epicoat 1001 ”,“ Epicoat 1004 ”, trade names“ Epicron 840 ”,“ Epicron 850 ”,“ Epicron 1050 ”,“ Epicron 2055 ”manufactured by Dainippon Ink and Chemicals, NS Bisphenol A type epoxy compounds such as “Epototo 128” manufactured by Kagaku Co .;
Product name “Epicron 830S” manufactured by Dainippon Ink & Chemicals, Inc. Product name “Epicoat 807” manufactured by Mitsubishi Chemical Co., Ltd. Product names “Epototo YDF-170”, “Epototo YDF-175”, “Epototo” manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. Bisphenol F type epoxy compounds such as “YDF-2004”;
Bisphenol S type epoxy compounds such as Nippon Kayaku's trade name "EBPS-200", Asahi Denka Kogyo's trade name "EPX-30", Dainippon Ink and Chemicals' trade name "Epicron EXA1514";
Bisphenol fluorene type epoxy compounds such as “BPFG” manufactured by Osaka Gas Co., Ltd., “YL-6056”, “YL-6021”, “YX-4000”, “YX-4000H” manufactured by Mitsubishi Chemical Corporation, etc. Bixylenol type or biphenyl type epoxy compounds, or mixtures thereof;
Hydrogenated bisphenol A type epoxy compounds such as “Epototo ST-2004”, “ST-2007”, “ST-3000” manufactured by Nippon Steel & Sumikin Chemical Co., Ltd .;
Product names “Epicoat 152” and “Epicoat 154” manufactured by Mitsubishi Chemical Corporation, product names “DEN 431” and “DEN 438” manufactured by Dow Chemical Company, Dainippon Ink and Chemicals, Inc. “Epicron N-690”, “Epicron N-695”, “Epicron N-730”, “Epicron N-770”, “Epicron N-865”, trade names “Epototo YDCN” manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. -701 "," Epototo YDCN-704 ", trade names" EPPN-201 "," EOCN-1025 "," EOCN-1020 "," EOCN-104S "," RE-306 "manufactured by Nippon Kayaku Co., Ltd. Novolac epoxy compounds;
Trade names “Epicoat YL-903” manufactured by Mitsubishi Chemical Corporation, “Epicron 152” and “Epicron 165” manufactured by Dainippon Ink and Chemicals, Inc. “Epototo YDB-400” manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. Brominated bisphenol A type epoxy compounds such as “Epototo YDB-500”;
Naphthalene skeletons such as trade names “ESN-190” and “ESN-360” manufactured by Nippon Steel Chemical Co., Ltd., trade names “HP-4032”, “EXA-4700” and “EXA-4750” manufactured by Dainippon Ink & Chemicals, Inc. An epoxy compound having:
Epoxy compounds having a dicyclopentadiene skeleton such as trade names “HP-7200” and “HP-7200H” manufactured by Dainippon Ink & Chemicals, Inc .;
Trishydroxyphenylmethane type epoxy compounds such as Mitsubishi Chemical's trade name “YL-933” and Nippon Kayaku's trade names “EPPN-501” and “EPPN-502”;
Heterocyclic epoxy compounds such as Nissan Chemical's trade name “TEPIC” and Mitsubishi Gas Chemical's trade name “TGI”;
Glycidylamine type epoxy compounds such as trade names “jER604” and “jER630” manufactured by Mitsubishi Chemical Corporation, “Epototo YH-434” manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., and “Araldite MY720” manufactured by Asahi Kasei Corporation;
Alicyclic epoxy compounds such as “Celoxide 2011” manufactured by Daicel Chemical Industries, “Araldite CY175”, “Araldite CY179” manufactured by Asahi Kasei Kogyo, and “HBE-100” manufactured by Shin Nippon Chemical Co., Ltd. However, it is not limited to these. These epoxy compounds can be used alone or in combination of two or more.
Among these, bisphenol A type epoxy compounds or bisphenol F type epoxy compounds are preferable from the viewpoint of adhesive strength.

  The epoxy equivalent of the epoxy compound (B) obtained by the reaction of the unsaturated fatty acid polymer (B1) and the compound (B2) having two or more epoxy groups used in the present invention is pot life, adhesive strength, It is preferably 200 to 7000 because it is excellent in chemical resistance. It is preferable that the epoxy equivalent is 200 or more from the viewpoint of improving the initial adhesive force due to the length of the pot life of the adhesive composition and the appropriate crosslinking density of the adhesive layer. Moreover, when the epoxy equivalent is 7000 or less, the crosslinking density of the adhesive layer can be increased, the initial adhesive force can be improved, and the chemical resistance can be improved.

The esterification reaction for producing the epoxy compound (B) obtained by the reaction of the unsaturated fatty acid polymer (B1) used in the present invention with the compound (B2) having two or more epoxy groups is known. The reaction can be performed. That is, the production method is not particularly limited, and for example, it is synthesized by a reaction between a carboxyl group and an epoxy group using a catalyst. In the presence of a catalyst, it can be easily carried out by contacting both at a temperature of 50 to 200 ° C., preferably 120 to 180 ° C. for 30 minutes to 20 hours, but usually the acid value of the reaction product is 5 mg KOH / g. The end point of the reaction is preferably the time when 1 mgKOH / g or less is reached.
Catalysts such as halides such as zinc chloride and lithium chloride;
Tertiary amines such as N, N-dimethylaniline, pyridine, triethylamine, hexamethylenediamine, diazabicycloundecene and their basic acids or odorates;
Quaternary ammonium salts such as tetramethylammonium chloride and trimethyldodecylbenzylammonium chloride;
Sulfonic acids such as paratoluenesulfonic acid are used.

  The epoxy compound (B) obtained by the reaction of the unsaturated fatty acid polymer (B1) and the compound (B2) having two or more epoxy groups can also be obtained as a commercial product. Examples include “Epicoat 871”, “Epicoat 872”, “Epicoat 872-X-75” manufactured by Mitsubishi Chemical Corporation, “YD-172”, “YD-172X75” manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.

From the viewpoint that the polyolefin resin (A) used in the present invention is excellent in adhesiveness and solubility, the content of carboxyl groups per 1 g of the polyolefin resin (A) is X (mmol), the content of acid anhydride groups When the amount is Y (mmol), X + 2Y is preferably 0.05 to 0.6.
When X + 2Y is less than 0.05, there are few acidic groups that serve as crosslinking points, crosslinking is not sufficient, and sufficient adhesive strength and electrolyte resistance may not be obtained. If it is larger than 0.6, the crosslinking strength of the coating film is large, so that the adhesive strength may be insufficient, or the solubility in a solvent may be reduced.

When the polyolefin resin (A) contained in the adhesive composition is P (g) and the epoxy group derived from the epoxy compound (B) is Z (mmol), Z / (X + 2Y) P is 0.3 to 10 It is more preferable that the epoxy compound (B) is included within the range of 0.5 to 7 inclusive.
In order to improve adhesive strength and electrolyte resistance, it is preferable that Z / (X + 2Y) P is 0.3 or more so that cohesion can be improved by forming a sufficient cross-linked structure. From the viewpoint of electrolyte resistance, it is preferable that Z / (X + 2Y) P is 10 or less so that an unreacted epoxy compound (B) does not remain.

  In order to increase the adhesive strength with the metal foil, the adhesive of the present invention can further contain a silane coupling agent. Examples of silane coupling agents include trialkoxysilanes having a vinyl group such as vinyltrimethoxysilane and vinyltriethoxysilane, 3-aminopropyltriethoxysilane, and N- (2-aminoethyl) 3-aminopropyltrimethoxysilane. Having a glycidyl group such as trialkoxysilane having an amino group such as 3-glycidoxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane Examples include trialkoxysilane. The addition amount of the silane coupling agent is preferably 0.1 to 5% by mass, and more preferably 0.5 to 3% by mass based on the solid content of the adhesive.

  The adhesive of the present invention can contain catechol or a derivative thereof in order to increase the adhesive strength with the metal foil. Specifically, catechol, t-butylcatechol, adrenaline, noradrenaline, dopamine, nordihydroguaiaretic acid and the like can be mentioned.

The adhesive composition of the present invention can contain an organic solvent. An epoxy compound (B) which can dissolve a material used in the present adhesive composition alone or as a mixed solvent, and which is obtained by reacting an unsaturated fatty acid polymer (B1) with a compound (B2) having two or more epoxy groups. ) Is inactive, and is not particularly limited as long as it can be volatilized and removed by overheating in the drying step during adhesive coating. Specific examples of these solvents include aromatic organic solvents such as toluene and xylene;
aliphatic organic solvents such as n-hexane and n-heptane;
Cycloaliphatic organic solvents such as cyclohexane and methylcyclohexane;
Ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone;
Ester solvents such as ethyl acetate and butyl acetate;
Alcohol solvents such as ethanol, methanol, n-propanol, 2-propanol, butanol, hexanol;
Ether solvents such as diisopropyl ether, butyl cellosolve, tetrahydrofuran, dioxane, butyl carbitol;
Glycol ether solvents such as diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, propylene glycol monomethyl ether;
Examples include glycol ester solvents such as ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, and diethylene glycol monoethyl ether acetate. These may be used alone or in combination of two or more.
Among these, from the viewpoint of the storage stability of the solution of the polyolefin resin (A), a combination of an aromatic organic solvent and a ketone solvent, a combination of an aromatic organic solvent and an alcohol solvent, an alicyclic organic solvent, The combined use of ketone solvents and the combined use of alicyclic organic solvents and alcohol solvents are preferred.

In the adhesive composition of the present invention, known additives such as a tackifier and a plasticizer may be blended as necessary within a range not impairing the effects of the invention.
Examples of tackifiers that can be 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. Used for the purpose of improving strength. These may be used alone or in any combination of two or more.
Examples of the plasticizer used in the present invention include liquid rubbers such as polyisoprene and polybutene, and process oil.

The adhesive composition of the present invention is suitably used for laminating the metal foil layer (12) and the heat seal layer (14).
Examples of the metal of the metal foil layer (12) include aluminum, copper, and nickel. These metal foils may be subjected to various surface treatments. Examples of the surface treatment include physical treatment such as sand blast treatment and polishing treatment, degreasing treatment by vapor deposition, etching treatment, and surface treatment such as primer treatment for applying a coupling agent or a coating agent.
The treatment agent for forming the surface treatment layer preferably contains a functional group that reacts with an epoxy group, and more preferably contains at least one functional group selected from the group consisting of carboxylic acid, hydroxyl group and amino group. Is preferred. The amino group here means 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 layer (12), the epoxy group in the adhesive layer and the functional group in the surface treatment layer when the adhesive composition is thermally cured. , A laminate having high initial adhesive strength and excellent electrolyte resistance can be obtained.

  The heat seal layer (14) is not particularly limited, but is preferably a polyolefin film, and at least selected from the group consisting of polyethylene, polypropylene, olefin copolymers, acid modified products thereof, and ionomers. An unstretched film made of one kind of thermoplastic resin is preferable. Although the thickness of a heat seal layer is not specifically limited, It is preferable that it is 20-150 micrometers.

A laminate using the adhesive composition of the present invention can be obtained, for example, as follows.
On one side of the metal foil layer (12) (or heat seal layer (14)), the adhesive composition of the present invention is applied, and the solvent is stripped (dried) to form an uncured adhesive layer. Then, after the heat seal layer (or metal foil) is stacked on the surface of the uncured adhesive layer under pressure at 60 to 150 ° C., it is allowed to stand at 40 to 80 ° C. for about 3 to 10 days. A layered product can be obtained by sufficiently curing the layer (also referred to as aging) and bonding the metal foil and the heat seal layer 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 0.5 to 10 g / m ² .

The packaging material for an electricity storage device of the present invention is the outer layer side adhesive on the other surface of the metal foil layer (12) (the surface where the adhesive layer (13) formed from the adhesive composition of the present invention is not in contact). A resin film layer (11) can be provided through the layer.
The resin film layer (11) is previously laminated on the metal foil layer (12) using an adhesive composition (which may be the same as or different from the adhesive composition of the present invention). Or after obtaining the laminated body of a metal foil layer (12) and a heat seal layer (14) using the adhesive composition of this invention, an outer layer side adhesive bond layer is attached to a metal foil layer (12). The resin film layer (11) can also be laminated.
Examples of the resin film layer (11) used include stretched films such as a polyester resin and a polyamide resin (nylon), and the resin film layer (11) uses a laminate as a packaging material for an electricity storage device and is used for an electricity storage device. When forming the container, the container is located outside the electrolyte solution.

The container for an electricity storage device of the present invention is obtained by using the above-described packaging material for an electricity storage device and molding the outer layer side resin film layer (11) to form a convex surface and the heat seal layer (14) to form a concave surface. be able to.
The “concave surface” as used in the present invention is a surface having a dent that can accommodate an electrolyte solution when the flat packaging material for an electricity storage device is molded into a tray shape as shown in FIG. The term “convex surface” as used in the present invention refers to the self-back surface (opposite surface, back surface) of the surface having the depression.

  An electricity storage device such as a secondary battery includes a battery body, a plurality of terminals respectively joined to a positive electrode and a negative electrode of the battery body, a battery container, and an electrolyte solution. The battery container is obtained from a laminate in which a metal foil layer (12) and a heat seal layer (14) are laminated via an adhesive layer (13) formed from the adhesive composition of the present invention. The heat seal layer is in contact with the electrolyte solution.

  The electrolyte solution starts to penetrate from the heat seal layer (14) toward the metal foil layer (12), but the adhesive layer (13) formed from the adhesive composition of the present invention has excellent resistance to the electrolyte solution. Therefore, the adhesive strength between the heat seal layer 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,% represents mass%, and part represents mass part.
<Quantification of carboxyl group>
The weighed sample a (g) was dissolved in refluxed xylene, cooled to room temperature, and then titrated with 0.1M ethanolic potassium hydroxide using phenolphthalein as an indicator. The end point of the titration was when the color of the indicator remained for 10 seconds. If the titer is b (ml), X can be obtained from the following equation.
X = 0.1 * b / a
<Quantification of acid anhydride group>
The weighed sample c (g) was dissolved in refluxed xylene, cooled to room temperature, and then octylamine d (mmol) equal to or greater than the acid anhydride group of the sample was added. The remaining octylamine was quantified by titrating with 0.1M ethanolic perchloric acid. If the titration amount is e (ml), Y can be obtained from the following equation.
Y = (0.1 * ed) / c

<Mass average molecular weight>
Using an HLC-8220GPC system manufactured by Tosoh Corporation with two TSKgel superHZM-N columns connected, the eluent was tetrahydrofuran, the column temperature was 40 ° C., and the flow rate was 0.35 ml per minute. A sample was prepared by dissolving 2 mg of polyolefin resin (A) in 5 ml of tetrahydrofuran. The mass average molecular weight was calculated in terms of standard polystyrene.

<Melting point, melting temperature energy (ΔE)>
The melting point and ΔE can be determined by DSC measurement according to JIS K7121. Specifically, it is obtained as follows.
When the diameter or each side of the polyolefin resin (A) of about 10 mg is 0.5 mm or less, it is used as it is, and if it exceeds 0.5 mm, it is cut into 0.5 mm or less and put into a container.
Heat to about 30 ° C above the melting point at 10 ° C per minute and then cool to about 50 ° C below Tg at 10 ° C per minute. If no clear Tg is observed, cool to about 50 ° C. below the melting point. Then, it calculated | required from the peak top of the peak corresponding to the melting which appears when it heated to about 30 degreeC higher than melting | fusing point at 10 degreeC per minute. Further, ΔE was obtained from the area of the part from the time when the peak corresponding to melting was separated from the baseline until it returned to the baseline again.
When two or more polyolefin resins (A) were used in combination, the melting point was determined from the peak top of the peak on the high temperature side, and ΔE was calculated from the sum of all peak areas obtained by melting.

<Copolymerization composition ratio>
The copolymer composition ratio of polyolefin was determined by ¹³ C measurement using NMR (JNM-LA400) manufactured by JEOL Ltd.
A 20 mg sample was dissolved in 1 ml deuterated chloroform and measured. The methylene group derived from ethylene is contained in 40-50 ppm, the methine group derived from propylene is contained in 25-30 ppm, and the methine group derived from 1-butene is contained in 30-35 ppm. The copolymer composition ratio was determined from the integration ratio of each peak.

<Synthesis Example 1>
Purified toluene 250mL, methylaluminoxane 0.5mg in terms of Al atom, dimethylsilyl-bis- (4,5,6,7,8-pentahydroazulen-2-yl) in a 500mL glass autoclave purged with nitrogen Zirconium dichloride was charged with 1.25 μg atoms in terms of Zr atoms and heated to 40 ° C. Subsequently, while supplying ethylene and propylene at a constant rate of 50 L / hr and 40 L / hr, respectively, 1-butene monomer was continuously supplied to maintain a constant pressure of 1.32 MPa at 40 ° C., and polymerization was started. . After polymerization at 40 ° C. for 8 hours, isopropanol was added to terminate 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 with ethylene / propylene / 1-butene = 46/33/15 (molar ratio).
20 g of the obtained polyolefin and 20 g of cellosolve acetate were charged and dissolved by heating in a nitrogen stream to a solution temperature of 110 ° C. A solution prepared by dissolving 4 g of maleic anhydride, 2 g of lauryl methacrylate and 0.6 g of benzoyl peroxide in 239.4 g of cellosolve acetate was added dropwise over 2 hours. The reaction was continued at that temperature for an additional hour after the addition. 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 resin (A1) having an acid anhydride group.
The Mw, melting point, and ΔE of the polyolefin resin (A-1) are 4700, 103 ° C., 45 mJ /
mg.

<Synthesis Examples 2-4, 6-12>
Polyolefin resins having acid anhydride groups (A-2) to (A) in the same manner as in Synthesis Example 1, except for the flow rate ratio and the polymerization temperature of the mixed gas at the time of olefin polymerization shown in Table 1, and the monomer addition amount at the time of graft polymerization -4) and (A-6) to (A-8) were obtained.

<Synthesis Example 5>
A polyolefin resin having an acid anhydride group was obtained in the same manner as in Synthesis Example 1 except for the flow rate ratio of the mixed gas shown in Table 1 and the monomer addition amount during graft polymerization. The polyolefin resin obtained was stored in an environment of 85 ° C. and 85% RH for 3 days to obtain a polyolefin resin (A-5) having a carboxyl group.

<Synthesis Example 9>
280 g of propylene-ethylene copolymer (propylene / ethylene = 82/18% by mass, mass average molecular weight 85000) was heated and melted in a four-necked flask in a nitrogen atmosphere, and then the system temperature was maintained at 180 ° C. and stirred. Then, 35.0 g of maleic anhydride as an acid component and 6.0 g of di-t-butyl peroxide as a radical generator were added over 2 hours, respectively, and then reacted for 1 hour. After completion of the reaction, the obtained reaction product was put into a large amount of acetone to precipitate a resin. This resin was further washed several times with acetone to remove unreacted maleic anhydride, and then dried under reduced pressure in a vacuum dryer to obtain an acid-modified polypropylene resin (mass average molecular weight 40000).
Using a stirrer equipped with a heat-resistant 1 liter glass container with a heater, 60.0 g of the acid-modified polypropylene resin, 60.0 g of tetrahydrofuran, 6.9 g of N, N-dimethylethanolamine (acid When 1.03.1 equivalent to the carboxyl group of the acid component in the modified polypropylene resin) and 173.1 g of distilled water were charged into a glass container and stirred at a rotation speed of 300 rpm, the resin was placed at the bottom of the container. Precipitation of particulate matter was not recognized, and it was confirmed that it was in a floating state. Therefore, while maintaining this state, the heater was turned on and heated after 10 minutes. The system temperature was maintained at 140 ° C. and stirring was continued for 60 minutes, and then the heater was turned off and naturally cooled to 60 ° C. After cooling, the temperature was maintained at 60 ° C., the solvent was removed under stirring and reduced pressure, water was added as necessary, and the medium was replaced with water to obtain an aqueous dispersion of polyolefin resin (A-9).

In Table 1, the symbols are as follows.
LMA: Lauryl methacrylate St: Styrene

<Synthesis Example 10>
46 g of POLPOL 1013 (C18 unsaturated fatty acid dimer acid, acid value 196 mg KOH / g), jER1001 (Mitsubishi Chemical Corporation, bisphenol A type epoxy compound, epoxy equivalent: 475), 154 parts, triphenylphosphine 4 parts Then, 160 parts of toluene and 40 parts of isopropyl alcohol were heated and dissolved in a four-necked flask under a nitrogen atmosphere, and the system temperature was kept at 100 ° C. with stirring. It was made to react until an acid value became 1.0 mgKOH / g or less, and the epoxy compound (B-1) of solid content 50% and epoxy equivalent 1236 was obtained by making it cool.

<Synthesis Example 11>
14 g of Pripol 1010 manufactured by Croda Japan (hydrogenated product of dimer acid of C18 unsaturated fatty acid, acid value 195 mgKOH / g), jER1007 (Mitsubishi Chemical Corporation, bisphenol A type epoxy compound, epoxy equivalent 1975 g / eq) 186 parts, tri After 4 parts of phenylphosphine, 160 parts of toluene and 40 parts of isopropyl alcohol were dissolved in a four-necked flask under heating in a nitrogen atmosphere, the system temperature was maintained at 100 ° C. with stirring. It was made to react until an acid value became 1.0 mgKOH / g or less, and it was made to cool, and the epoxy compound (B-2) of 50% of solid content and the epoxy equivalent 4238 was obtained.

<Synthesis Example 12>
7 g of Pripol 1010 manufactured by Croda Japan (hydrogenated product of dimer acid of C18 unsaturated fatty acid, acid value 195 mgKOH / g), 193 parts of jER1010 (Mitsubishi Chemical Corporation, bisphenol A type epoxy compound, epoxy equivalent 4000 g / eq), tri After 4 parts of phenylphosphine, 160 parts of toluene and 40 parts of isopropyl alcohol were dissolved in a four-necked flask under heating in a nitrogen atmosphere, the system temperature was maintained at 100 ° C. with stirring. It was made to react until an acid value became 1.0 mgKOH / g or less, and it was made to cool, and the epoxy compound (B-3) of 50% of solid content and the epoxy equivalent of 8288 was obtained.

<Synthesis Example 13>
109 parts of Tripol 1004 (dimer acid hydrogenated C22 unsaturated fatty acid, acid value 162 mgKOH / g), jER630 (Mitsubishi Chemical Co., Ltd., glycidylamine type epoxy compound, epoxy equivalent 96 g / eq) 91 parts, Trida After 4 parts of phenylphosphine, 160 parts of toluene and 40 parts of isopropyl alcohol were dissolved in a four-necked flask under heating in a nitrogen atmosphere, the system temperature was maintained at 100 ° C. with stirring. It was made to react until an acid value became 1.0 mgKOH / g or less, and it was made to cool, and the epoxy compound (B-4) of 50% of solid content and the epoxy equivalent 317 was obtained.

<Synthesis Example 14>
Cropol Japan Co., Ltd. Pripol 1040 (C18 unsaturated fatty acid trimer acid, acid value 189 mg KOH / g) 22 g, jER4005P (Mitsubishi Chemical Corporation, bisphenol F type epoxy compound, epoxy equivalent 1175 g / eq) 178 parts, triphenylphosphine 4 parts Then, 160 parts of toluene and 40 parts of isopropyl alcohol were heated and dissolved in a four-necked flask under a nitrogen atmosphere, and the system temperature was kept at 100 ° C. with stirring. It was made to react until an acid value became 1.0 mgKOH / g or less, and it was made to cool, and the epoxy compound (B-5) of 50% of solid content and the epoxy equivalent 3822 was obtained.

<Synthesis Example 15>
In a four-necked flask, 87 g of lauric acid (acid value 200 mg KOH / g), 113 parts of Mitsubishi Gas Chemical Co., Ltd. TETRAD-C (epoxy equivalent 91 g / eq), 4 parts of triphenylphosphine, 160 parts of toluene and 40 parts of isopropyl alcohol After heating and dissolving in a nitrogen atmosphere, the system temperature was kept at 100 ° C. with stirring. It was made to react until an acid value became 1.0 mgKOH / g or less, and it was made to cool, and the epoxy compound (B-5) of 50% of solid content and the epoxy equivalent 645 was obtained.

<Synthesis example of additive>
In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser and a nitrogen gas introduction tube, 545.5 parts of jER1001 (Mitsubishi Chemical Corporation, bisphenol A type epoxy compound, epoxy equivalent: 475) and 259.0 parts of diethylene glycol dimethyl ether Was heated up to 80 ° C. while being heated and dissolved. After dissolution, 59.7 parts of acrylic acid was charged at 80 ° C., followed by 0.6 parts of dibutylhydroxytoluene and 2.4 parts of triphenylphosphine, and stirred while raising the temperature to 110 ° C. over 1 hour. . The reaction was continued by maintaining at 110 ° C. for 3 hours. When the acid value became 1.0 mgKOH / g or less, the temperature was lowered to 80 ° C., and 12.1 parts of 85% phosphoric acid and 70.2% diethylene glycol dimethyl ether were used. The mixture consisting of parts was continuously added dropwise over 1 hour. The phosphoric acid-modified epoxy having a non-volatile content of 64.0% and an acid value of 9.0 by continuously reacting at 80 ° C. for 4 hours after completion of the dropping and then charging 50.5 parts of diethylene glycol dimethyl ether. A solution of compound (C-1) was obtained.

<Example 1>
15 parts of polyolefin resin (A1) was heated and dissolved in 117.9 parts of toluene / methyl ethyl ketone (hereinafter referred to as MEK) = 7/3 (weight ratio). After cooling, 5.8 parts of jER871 (manufactured by Mitsubishi Chemical Corporation, dimer acid-modified epoxy compound having an epoxy equivalent of 430) was added and stirred to obtain an adhesive solution having a solid content of 15%.
The adhesive solution was applied to a 40 μm aluminum foil with a bar coater and dried at 100 ° C. for 1 minute to obtain an adhesive layer having a coating amount of about 2 g / m ² after drying. Next, an unstretched polypropylene film (hereinafter referred to as CPP) having a thickness of 40 μm was superposed on the adhesive layer and passed between two rolls set at 80 ° C. to obtain a laminate. Thereafter, the obtained laminate was cured (aging) at 40 ° C. for 3 days or 5 days. The aluminum foil / CPP laminate film thus obtained is hereinafter referred to as “Al / CPP laminate film”.
The initial adhesive strength, solvent resistance, and electrolyte resistance were evaluated according to the methods described below. The results are shown in Table 2.

<Examples 2 to 22>, <Comparative Examples 1 to 6>
With the compositions shown in Tables 2 and 3, an adhesive solution and an Al / CPP laminated film were obtained in the same manner as in Example 1 and evaluated in the same manner.

The symbols in Tables 2 and 3 are as follows.
P-401: “Unistor P-401”, manufactured by Mitsui Chemicals, acid-modified polyolefin resin, solid content acid value 55 mg KOH / g, heating residue 8%
P-902: “Unistor P-902”, manufactured by Mitsui Chemicals, acid-modified polyolefin resin, solid content acid value 55 mgKOH / g, heating residue 22%

jER871: Dimer acid-modified epoxy compound manufactured by Mitsubishi Chemical Corporation (epoxy equivalent 430 g / eq)
YD172: Nippon Steel & Sumikin Chemical Co., Ltd. dimer acid-modified epoxy compound (epoxy equivalent 650 g / eq)

jER630: manufactured by Mitsubishi Chemical Corporation, N, N-bis (2,3-epoxypropyl) -4- (2,3-epoxypropoxy) aniline (epoxy equivalent 96 g / eq)
TETRAD-C: manufactured by Mitsubishi Gas Chemical Company, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane (epoxy equivalent 91 g / eq)

B-7: Adeka Resin EM-0517 (manufactured by Adeka Co., Ltd., glycidyl ether type epoxy resin at the time of bisphenol A) diluted with water to a solid content concentration of 10% B-8: Vasonate HW-100 (BASF non-block type) Diluted with water to a solid content concentration of 10%.

860: “EPICLON 860”, manufactured by DIC Corporation, bisphenol A type epoxy resin having an epoxy equivalent of 245 g / eq, TPP: triphenylphosphine

Mixed solvent 1: toluene / methyl ethyl ketone = 7/3 (mass ratio)
Mixed solvent 2: toluene / isopropyl alcohol = 8/2 (mass ratio)
Mixed solvent 3: methylcyclohexane / isopropyl alcohol = 8/2 (mass ratio)

[Compatibility]
The adhesive solution was applied to a 100 μm PET film with a bar coater and dried at 100 ° C. for 1 minute to obtain an adhesive layer having a coating amount after drying of about 2 g / m ² . By measuring the haze of this laminated film according to JIS K7136, the compatibility was determined according to the following criteria.
A: Less than 3 B: 3 or more and less than 5 C: 5 or more

[Initial bond strength]
The Al / CPP laminated film was allowed to stand for 6 hours in an environment of 25 ° C. and a humidity of 65%, then cut to a size of 200 mm × 15 mm, and a tensile tester was used according to the test method of ASTM-D1876-61. Then, a T-type peel test was performed at a load speed of 100 mm / min in an environment of 25 ° C. and a humidity of 65%. The peel strength (N) of 15 mm width between the aluminum foil / CPP is shown as an average value of five test pieces. Judgment was made according to the following criteria.
A: 10N or more B: 5N or more and less than 10N C: less than 5N

[Solvent resistance, electrolyte resistance (change in adhesive strength)]
Test pieces similar to those used in the initial adhesive strength test were immersed in the following organic solvent and electrolyte solution for 2 weeks, respectively. 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 adhesive strength of the test piece was measured in the same manner as the adhesive strength measurement before the immersion test. Judgment was made according to the following criteria.
A: Change rate is less than ± 10% with respect to initial bond strength B: Change rate is less than ± 30% with respect to initial bond strength C: Change rate with respect to initial bond strength is ± 30% or more [organic Solvent]: 40 ° C. ethylene carbonate.
[Electrolyte solution]: A solution prepared by dissolving lithium hexafluorophosphate in ethylene carbonate / diethyl carbonate / dimethyl carbonate = 1/1/1 (volume ratio) so as to be 1.5 mol / l. The temperature was 85 ° C.

As shown in Examples 1 to 19 in Table 2, an adhesive having good adhesive strength (initially, after immersion in an organic solvent and an electrolyte solution) can be provided even if the aging period is short.
The adhesives of Comparative Examples 1 and 5 are epoxy compounds that do not contain a polymerized fatty acid-modified site, and are less compatible with polyolefins than the epoxy resin (B) of the present invention, so that adhesive strength is manifested in aging in a short period of time. The adhesion strength is significantly reduced after immersion in an organic solvent or electrolyte solution.
Since the adhesive of Comparative Example 2 uses an isocyanate compound having low solvent resistance as a curing agent in addition to the bisphenol A type epoxy resin, the solvent resistance is further deteriorated compared to Comparative Example 1.
Since the adhesives of Comparative Examples 3 and 4 use phosphoric acid epoxy, the solvent resistance is improved as compared with Comparative Example 5, but the adhesive strength is not sufficiently exhibited by short-term aging.
Although the adhesives of Comparative Examples 4 and 6 use an epoxy compound having a phenylphosphine or an amino group as a catalyst for the reaction between an acid anhydride or a carboxyl group and an epoxy group, the adhesive strength is low when aging is performed for a short period of time. Not fully expressed.

In addition, two laminates (rectangles) of each example were used, and three sides were heat-sealed so that the CPP became the inner surface, and a pouch (bag) was created. When two aluminum pieces as pseudo electrode terminals are not brought into contact with each other and are heat-sealed by sandwiching them between two laminates at the open end, high temperature (150 to 200 ° C.), high pressure (0.5 to 3. Even when heat-sealing at 0 kg / cm ² ), the adhesive layer did not melt or deform significantly.
However, in Comparative Example 2 in which an isocyanate compound is used in combination with the curing agent, when the heat seal is performed under high temperature and high pressure, the adhesive melts and protrudes from the end portion. In some cases, the sex could not be secured.

The adhesive composition according to the present invention can be suitably used for a packaging material (laminate) for forming a container for an electricity storage device such as a lithium ion battery, an electric double layer capacitor, or a lithium ion capacitor.
In addition, the adhesive composition according to the present invention is a packaging material for forming a container for an electricity storage device, as well as various industrial fields that require high adhesive strength and chemical resistance, such as architecture, chemistry, medicine, and automobiles. It is used suitably for formation of the laminated body in.

Resin film layer (11)
Metal foil layer (12)
Adhesive layer (13)
Heat seal layer (14)

Claims (13)

An adhesive composition for laminating a metal foil layer and a heat seal layer via an adhesive layer,
An epoxy compound (B) obtained by a reaction between a polyolefin resin (A) having a carboxyl group or an acid anhydride group, a polymer (B1) of an unsaturated fatty acid and a compound (B2) having two or more epoxy groups; An adhesive composition comprising:   The epoxy compound (B) is an epoxy compound obtained by further hydrogenating a reaction product of a polymer (B1) of an unsaturated fatty acid and a compound (B2) having two or more epoxy groups. The adhesive composition according to claim 1.   The polymer (B1) of unsaturated fatty acid is a compound (dimer acid) or a compound (trimer acid) obtained by dimerizing an unsaturated fatty acid having 12 to 24 carbon atoms. Item 3. The adhesive composition according to item 1 or 2.   The adhesive composition according to any one of claims 1 to 3, wherein the compound (B2) having two or more epoxy groups is selected from a bisphenol A type epoxy compound or a bisphenol F type epoxy compound.   The adhesive composition according to any one of claims 1 to 4, wherein an epoxy equivalent of the epoxy compound (B) is 200 to 7000.   The adhesive composition according to claim 1, wherein the polyolefin resin (A) has a mass average molecular weight of 50,000 to 500,000.   The adhesion according to any one of claims 1 to 6, wherein the polyolefin resin (A) is obtained by further acid-modifying a copolymer obtained from 1-butene and another olefin. Agent composition.   When the content of carboxyl groups per 1 g of the polyolefin resin (A) is X (mmol) and the content of acid anhydride groups is Y (mmol), X + 2Y is 0.05 to 0.6. It is, The adhesive composition of any one of Claims 1-7 characterized by the above-mentioned.   When the content of the polyolefin resin (A) is P (g) and the epoxy group in the epoxy resin (B) is Z (mmol), Z / [(X + 2Y) P] is 0.3 to 10 The adhesive composition according to claim 8, wherein the adhesive composition is present.   The laminated body by which a metal foil layer and a heat seal layer are laminated | stacked through the adhesive bond layer formed from the adhesive composition of any one of Claims 1-9. In order from the outer layer, in a packaging material for an electricity storage device that requires a resin film layer, a metal foil layer, an adhesive layer, and a heat seal layer,
The said adhesive bond layer is formed from the adhesive composition of any one of Claims 1-9, The packaging material for electrical storage devices characterized by the above-mentioned.   The container for electrical storage devices formed from the packaging material for electrical storage devices of Claim 11, Comprising: The container for electrical storage devices in which the heat seal layer comprises the inner surface.   An electrical storage device using the electrical storage device container according to claim 12.