JP2003155313A - Epoxy group-containing vinylidene fluoride-based copolymer, resin composition containing the same, electrode structure and non-aqueous electrochemical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vinylidene fluoride-based copolymer having good adhesive property to a substrate such as of metal and high thermal stability, thus highly suitable as an electrode binder for non-aqueous electrochemical devices such as secondary batteries or electrical double layer capacitors, to provide a composition containing the copolymer, and to provide such an electrochemical device. SOLUTION: This copolymer is obtained by suspension copolymerization between vinylidene fluoride as the main component and a minor amount of an epoxy group-containing acrylic vinyl monomer preferably in an aqueous dispersion medium.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention provides a polyvinylidene fluoride copolymer and a cured product having excellent heat resistance and chemical resistance, which has good adhesiveness to a base material such as metal containing the same. It relates to a resin composition. Such a resin composition is useful in fields such as binders and paints. The present invention also provides an electrode structure for a non-aqueous electrochemical device containing such a vinylidene fluoride-based copolymer as a binder, and further a non-aqueous electrical device such as a secondary battery or an electric double layer capacitor containing the electrode structure. Regarding chemical elements.

[0002]

2. Description of the Related Art Polyvinylidene fluoride resins have excellent chemical resistance, weather resistance, stain resistance and the like and are used not only as various films or molding materials but also as paints and binders. However, since the polyvinylidene fluoride-based resin has a small adhesive strength with a base material such as a metal, improvement in the adhesive strength is desired.

Japanese Patent Laid-Open No. 3-17109 discloses (a) 5
0 to 98 mol of vinylidene fluoride and (b) 2 to 50 mol of fluorine selected from tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene or a mixture of at least two of these three monomers. Substantially consisting of units derived from a fluorinated monomer and (c) an epoxidized allyl ether such as 2 to 20 moles of allyl glycidyl ether per 100 moles of the fluorinated monomer. 2 at a concentration of 1 g / dl
It is disclosed that a curable copolymer having an intrinsic viscosity in the range of 0.03-0.4 dl / g as a solution in dimethylformamide at 5 ° C. is obtained by solution polymerization. These copolymers are soluble in solvents such as butyl acetate, isobutyl acetate, ethyl acetate, melamine formaldehyde,
As a paint or varnish that forms a coating that adheres well to metal, glass, wood, cement, plastic, etc. because it crosslinks and cures when mixed with well-known curing agents such as polyamide, organic acids and their anhydrides, and heated. It discloses that it can be used.

However, these copolymers are soluble in the above-mentioned general solvents, and those which are not cured are not applicable to the fields requiring chemical resistance or heat resistance. In addition, even if it has been subjected to a curing treatment, when it is used in a field requiring a high degree of chemical resistance such as when it is used as a binder for manufacturing electrodes of a non-aqueous solvent type lithium secondary battery or an electric double layer capacitor, etc. It's not enough.

The present applicant has conducted research to obtain a vinylidene fluoride-based copolymer having improved adhesion to a substrate such as a metal while taking advantage of the excellent properties of vinylidene fluoride resin.
Already, copolymers of vinylidene fluoride and polar monomers such as monoesters of unsaturated dibasic acids or / and epoxidized allyl ethers such as allyl glycidyl ether have improved adhesion and solvent resistance (JP-A-6-172452 and JP-A-6-172452).
-12639).

[0006]

However, according to the study by the present inventors, the vinylidene fluoride copolymer thus obtained is also used for the production of electrodes for non-aqueous electrochemical devices which generate heat during use. It has been found that there is room for improvement in heat resistance, since there is a risk of causing a thermal decomposition reaction accompanied by dehydrofluoric acid when used as a binder. In particular, it has been recognized that this thermal decomposition occurs more remarkably when a powdered carbon material or the like is blended to form an electrode than when the resin is used alone. It is also desired to further improve the adhesiveness with a current collecting substrate such as metal. Further, in order to obtain a vinylidene fluoride-based copolymer having excellent solvent resistance, it is desirable to use a suspension polymerization method, but the vinylidene fluoride-based copolymer is
There is also a problem that it does not necessarily have good polymerization characteristics.

[0007] Therefore, the main object of the present invention is to provide a vinylidene fluoride copolymer having good adhesion to a substrate such as a metal and having improved heat resistance stability.

Another object of the present invention is to provide a method for producing the above vinylidene fluoride copolymer.

Another object of the present invention is to provide a resin composition containing the above-mentioned vinylidene fluoride copolymer, an electrode structure for a non-aqueous electrochemical device, and further a non-aqueous electrochemical device, especially a secondary battery. And to provide an electric double layer capacitor.

[0010]

According to the research conducted by the present inventors, a copolymer of vinylidene fluoride and an acrylic vinyl monomer having a relatively small amount of epoxy group was unexpectedly found to have the above-mentioned fluorine content. Compared with copolymers of vinylidene chloride and polar monomers such as unsaturated dibasic acid monoesters and / or epsilated allyl ethers such as allyl glycidyl ether, it shows significantly better copolymerization properties during suspension polymerization. It has been found that not only does it show improved heat resistance stability, but also has good adhesion to substrates such as metals.

That is, the present invention is, firstly, a copolymer which is a copolymer of 100 mol of vinylidene fluoride monomer and 0.1 to 5.0 mol of an acrylic vinyl monomer containing at least an epoxy group. A vinylidene chloride copolymer is provided.

Further, the method for producing a vinylidene fluoride copolymer of the present invention is characterized in that the above vinylidene fluoride copolymer is produced by suspension polymerization using water as a dispersion medium. .

Furthermore, the present invention provides a resin composition obtained by dissolving the above vinylidene fluoride copolymer in an organic solvent, an electrode mixture composition obtained by adding a powder electrode material to the resin composition, and further, The present invention provides an electrode structure for a non-aqueous electrochemical element, which comprises applying the electrode mixture composition onto a current collecting substrate and removing an organic solvent to form a porous electrode layer.

Further, the present invention comprises a positive electrode, a negative electrode, and a non-aqueous electrolytic solution disposed between the positive electrode and the negative electrode, and at least one of the positive electrode and the negative electrode comprises the above electrode structure. The present invention provides a secondary battery and an electric double layer capacitor in which a non-aqueous electrolyte is placed between a pair of the electrode structures.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The vinylidene fluoride-based copolymer of the present invention comprises at least 100 mol of vinylidene fluoride monomer and 0.1-5.
0 mol, preferably 0.2 to 3.0 mol. Epoxy group-containing acrylic vinyl monomer is 0.
If it is less than 1 mol, a predetermined effect of improving the adhesiveness to a substrate such as a metal cannot be obtained, and if it is added in an amount of more than 5.0 mol, a further effect of improving the adhesiveness cannot be obtained. It is not preferable because the polymerization time for obtaining the copolymer tends to be long.

The epoxy group-containing acrylic vinyl monomer used in the present invention is generally a substituted or unsubstituted glycidyl (meth) acrylate (herein, the term "(meth) acrylate" means acrylate and methacrylate). It is used as a comprehensive term), and preferable specific examples thereof include glycidyl (meth) acrylate, 2-methylglycidyl (meth) acrylate, 2-ethylglycidyl (meth) acrylate, and 1 -Methylglycidyl (meth) acrylate. From the viewpoint of providing a vinylidene fluoride copolymer having good thermal decomposition stability, methacrylate is preferable to acrylate, and substituted glycidyl methacrylate is particularly preferable.

In order to ensure good heat resistance and solvent resistance, the vinylidene fluoride copolymer is used in an amount of 150 to 180.
C., more preferably 160 to 180.degree. C., melting point (DSC
The maximum endothermic peak temperature in crystal melting at a temperature rise of 10 ° C./min in a nitrogen atmosphere according to
And 0.5 to 5 dl / g, more preferably 0.7 to 4
It preferably has an inherent viscosity of dl / g (logarithmic viscosity at 30 ° C. of a solution of 4 g of resin dissolved in 1 liter of N, N-dimethylamide).

Generally, the melting point of a vinylidene fluoride copolymer decreases as the amount of the comonomer increases when the amount of the monomer (comonomer) copolymerized with the vinylidene fluoride monomer is relatively small. Further, the vinylidene fluoride-based copolymer has a larger inherent viscosity,
Its solvent resistance and mechanical strength are excellent. However, since a copolymer having a large intrinsic viscosity has low solubility in a solvent, an inherent viscosity in the above range is preferable.

In addition to the above vinylidene fluoride monomer and epoxy group-containing acrylic vinyl monomer, a third monomer is added within a range not deviating from the object of the present invention to obtain a vinylidene fluoride copolymer. Obtainable. Examples of such a third monomer include a vinylidene fluoride-based monomer obtained by copolymerizing a fluorine-based monomer copolymerizable with vinylidene fluoride or a hydrocarbon-based monomer such as ethylene or propylene. It is also possible to control the solubility of the copolymer in a solvent. Examples of the fluorine-based monomer copolymerizable with vinylidene fluoride include vinyl fluoride, trifluoroethylene, chlorotrifluoroethylene, tetrafluoroethylene, hexafluoropropylene, fluoroalkyl vinyl ether and the like. Two or more kinds of the third monomer,
It can also be used together.

However, it is preferable that the amount of the third monomer used is within the range where the above-mentioned melting point and inherent viscosity are satisfied in the obtained vinylidene fluoride copolymer, and more specifically. Is preferably 5 mol or less, more preferably 4 mol or less, per 100 mol of the vinylidene fluoride monomer.

The above-mentioned vinylidene fluoride copolymer of the present invention can be produced by a method such as suspension polymerization, emulsion polymerization or solution polymerization. As the polymerization method, aqueous suspension polymerization or emulsion polymerization is preferable, and aqueous suspension polymerization is particularly preferable, from the viewpoints of solvent resistance of the resulting copolymer, easiness of post-treatment and the like.

In suspension polymerization using water as a dispersion medium, a suspending agent such as methyl cellulose, methoxylated methyl cellulose, propoxylated methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, polyvinyl alcohol, polyethylene oxide and gelatin is used.
0.005-1.0 wt% with respect to water, preferably 0.1.
It is used by adding in the range of 01 to 0.4% by weight.

As the polymerization initiator, diisopropyl peroxydicarbonate, dinormal propyl peroxy dicarbonate, dinormal heptafluoropropyl peroxy dicarbonate, isobutyryl peroxide, di (chlorofluoroacyl) peroxide, di (per) Fluoroacyl) peroxide or the like can be used. The amount used is 0.1 to 5% by weight, preferably 0.5 to 2% by weight, based on the total amount of monomers.

Controlling the degree of polymerization of the resulting polymer by adding a chain transfer agent such as ethyl acetate, methyl acetate, acetone, ethanol, n-propanol, acetaldehyde, propyl aldehyde, ethyl propionate, carbon tetrachloride. Is also possible. The amount used is usually 0.1 to 5% by weight, preferably 0.5 to 3% by weight based on the total amount of monomers.
% By weight.

The total charged amount of the monomers is 1: 1 to 1:10, preferably 1: 2 to 1: 1, in the weight ratio of the total amount of the monomers: water.
5 and the polymerization is carried out at a temperature of 10 to 50 ° C. for 10 to 100 hours.

By the above suspension polymerization, the vinylidene fluoride copolymer of the present invention can be easily produced.

The vinylidene fluoride-based copolymer of the present invention,
For example, by dissolving 100 parts by weight in an organic solvent of 500 to 2000 parts by weight, the resin composition of the present invention, which is suitably used as a paint, a lining material, a binder, etc., can be obtained. As a solvent, N-methyl-2-pyrrolidone, N, N- which dissolves a vinylidene fluoride polymer well
Dimethylformamide, N, N-dimethylacetamide, dimethylsulfoxide and the like are preferable.

Further, the epoxy group-containing vinylidene fluoride copolymer of the present invention has curability of the epoxy group by itself due to the presence of the coexisting (meth) acrylate group. It is also possible to further mix a curing agent in an amount of 0.3 to 3.0 mol with respect to 1 mol of an epoxy group and use it as a coating material, a binder or the like.

As the curing agent, amines (diethylenetriamine, triethylenetetramine, ethylenediamine, tetraethylenepentamine, etc.) and acid anhydrides (phthalic anhydride, succinic anhydride) used as curing agents for general epoxy resins are used. Compounds, pyromellitic dianhydride, etc.), low molecular weight curing agents such as amine adducts of glycidyl ether, etc. can also be used.

The vinylidene fluoride copolymer of the present invention has an average particle diameter of 1000 μm or less, particularly 50 to 350 μm, in order to enable rapid dissolution in the above solvent.
It is also desirable to use it with a small particle size.

The resin composition of the present invention thus obtained is
After being applied to a substrate such as a metal, the solvent is evaporated and, if necessary, cross-linked and cured to form a coating film having excellent adhesion to the substrate, chemical resistance and electrolytic solution resistance. Thus, the resin composition of the present invention is preferably used as a binder, paint, or lining agent that is required to have adhesiveness to a substrate such as metal and solvent resistance and chemical resistance. It exhibits extremely excellent suitability as a strong binder for electrode production of non-aqueous electrochemical devices. Therefore, this application will be described in more detail.

FIG. 1 is a partially exploded perspective view of a lithium secondary battery as an example of a secondary battery which is a non-aqueous electrochemical device of the present invention.

That is, this secondary battery is basically a positive electrode 1 and a negative electrode 2 in which a separator 3 made of a microporous film of a polymer substance such as polypropylene or polyethylene impregnated with an electrolytic solution is arranged and laminated. The power generating element having a spirally wound shape is housed in a bottomed metal casing 5 forming the negative electrode terminal 5a. In this secondary battery, further, the negative electrode is electrically connected to the negative electrode terminal, and the gasket 6 and the safety valve 7 are arranged on the top portion, and then the positive electrode terminal 8a which is electrically connected to the positive electrode 1 on the convex portion constitutes the top portion. The plate 8 is arranged, the top rim 5b of the casing 5 is caulked, and the entire structure is sealed.

Here, the electrode structure 10 constituting the positive electrode 1 or the negative electrode 2 has a partial sectional structure as shown in FIG.
It is made of metal foil such as iron, stainless steel, steel, aluminum, nickel, titanium, copper, or metal mesh, and has a thickness of 5
.About.100 .mu.m, and in the case of a small scale, for example, 5 to 20 .mu.m on at least one surface of the current collector 11, preferably both surfaces as shown in FIG.
The electrode mixture layers 12a and 12b having a thickness of up to 1000 μm are formed.

The electrode mixture layers 12a and 12b are coated on the current collector 11 with an electrode mixture forming composition comprising an active material as a powder electrode material, a binder and a conductive material such as carbon added as necessary. It is formed by bonding.

In the case of the positive electrode, the active material is represented by the general formula L
A complex metal chalcogen compound represented by iMY ₂ (M is at least one kind of transition metal such as Co and Ni: Y is a chalcogen element such as O and S), particularly, a complex metal oxide including LiCoO ₂ is preferable. In the case of negative electrode, graphite,
Activated carbon or a carbonaceous substance such as one obtained by firing and carbonizing a phenol resin or pitch is preferable as the active material.

The conductive material is added for the purpose of improving the conductivity of the electrode mixture layer when an active material having a small electron conductivity such as LiCoO ₂ is used, and carbon such as carbon black, graphite fine powder or fibers is used. Fine materials, fine metal powders such as nickel and aluminum, or fibers are used. When a carbonaceous material having high conductivity is used as the active material, it is not necessary to use these conductive materials.

Since the binder does not contribute to the charge / discharge capacity of the battery at all, it is necessary to use the binder in an extremely small amount. Even a small amount of the binder holds the active material and the like and has excellent adhesiveness to the current collector. Is required. Further, since the binder is usually electrically insulating, an increase in the amount used increases the internal resistance of the battery. From this point as well, the binder is required to fulfill its function with the least amount used.

Usually, the amount of the binder is extremely small, and is 30% by weight or less based on the whole electrode mixture. With such a small amount of binder, the active material and / or
Alternatively, the binder cannot completely fill the voids between the fine components such as the conductive material or between the fine components and the current collector.
In the case of paints, lining materials, etc. containing fillers such as pigments, the binder uses a large amount of the binder sufficient to completely fill the voids between the fillers, etc. Absent. However, in the case of a binder for electrodes, the amount used is extremely small as described above, and it is required that the binder retains the active material well even in a small amount and has excellent adhesiveness to the current collector.

The non-aqueous electrolytic solution with which the separator 3 is impregnated includes LiClO ₄ and LiP in a solvent having a strong dissolving power for polymers such as ethylene carbonate, propylene carbonate, dimethoxyethane, tetrahydrofuran and γ-butyrolactone.
Since a solution in which an electrolyte such as F ₆ or LiBF ₄ is dissolved is used, the binder is required to have solvent resistance that does not significantly deteriorate the function of the binder even when immersed in these solvents for a long time.

When the resin composition of the present invention is used as a binder for producing the thin film electrode structure 10 of a battery,
The following is preferable.

The epoxy group-containing vinylidene fluoride-based copolymer of the present invention and a curing agent added as necessary are dissolved in an organic solvent to obtain the resin composition of the present invention as described above.

Next, an active material and a conductive agent are further added to and mixed with the resin composition to form a slurry composition, for example, a metal foil or metal net having a thickness of about 5 to 20 μm. Is uniformly applied to the current collector, dried, and heated and pressed to form a thin electrode mixture layer having a thickness of, for example, about 100 μm on the current collector to form a thin film electrode. During the hot press, the solvent is evaporated, and the resin is crosslinked / cured as necessary to ensure strong adhesion with the current collector and the fine filler.

The ratio of the fine components (active material and conductive agent) to the vinylidene fluoride copolymer in the electrode-forming composition is usually about 80:20 to 98: 2 by weight, and the ratio of the fine components is It is determined in consideration of holding, adhesion to the current collector, and conductivity of the electrode.

Another preferred embodiment of the non-aqueous electrochemical device of the present invention is an electric double layer capacitor. FIG. 3 is a cross section of a single-cell electric double layer capacitor as an example thereof. In this electric double layer capacitor, a separator 23 is sandwiched between a pair of polarizable electrodes 20a and 20b, each of which corresponds to an example of the electrode structure of the present invention, and a stainless steel cap 24 and a non-aqueous electrolytic solution 26 are further placed between them. Packing 2 between the stainless steel cans 5
It has a structure in which it is enclosed via 7. As a result, the non-aqueous electrolytic solution 26 is impregnated in the separator 23 and is arranged between the pair of polarizable electrodes 20a and 20b. The pair of polarizable electrodes 20a and 20b are formed by forming electrode mixture layers 22a and 22b on one surface of current collecting substrates 21a and 21b similar to the current collecting substrate 11 shown in FIG. 2, respectively. Each of the layers 22a and 22b contains the vinylidene fluoride-based copolymer of the present invention as a binder in a proportion of, for example, about 0.5 to 15% by weight, more preferably 2 to 10% by weight, and the rest is a powder electrode. As the material, activated charcoal such as coconut shell type, phenol type, petroleum coke type and pitch having a specific surface area of preferably about 500 to 3000 m ² / g and activated carbon or polyacene activated by a suitable manufacturing method using them A powdered carbon material consisting of, and a conductive agent added as necessary (similar to that contained in the electrode mixture layer for secondary batteries), etc. Ri, as the nonaqueous electrolytic solution 26 such as quaternary
A solution in which a quaternary phosphonium salt or a quaternary ammonium salt such as (C ₂ H ₅ ) ₄ NBF ₄ is used as an electrolyte and is dissolved in a solvent similar to the above-mentioned secondary battery solvent such as propylene carbonate is used. .

In such an electric double layer capacitor as well, the binder forming the electrode mixture layer is required to have good adhesion to the current collecting substrate, electrolyte resistance and heat resistance. The epoxy group-containing vinylidene fluoride-based copolymer of the present invention is preferably used, as in the case of the next battery.

[0047]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples.

Example 1 (Resin A: VDF / 2M-GMA) 1036 g of ion-exchanged water, 41.7 g of methyl cellulose, 2.0 g of ethyl acetate, isopropyl peroxydicarbonate (IPP) were added to an autoclave having a content of 2 liters. Charged 2 g, vinylidene fluoride 400 g, and dimethylglycidyl methacrylate 4 g (vinylidene fluoride: 2-methylglycidyl methacrylate (molar ratio) = 100: 0.4
1) Suspension polymerization was carried out at 28 ° C. for 27 hours.

After the completion of the polymerization, the polymer slurry was dehydrated, washed with water, dehydrated, and dried at 80 ° C. for 20 hours to obtain a powdery resin A corresponding to the epoxy group-containing vinylidene fluoride copolymer of the present invention. The polymerization yield was about 80% by weight.

Resin A has an inherent viscosity (resin concentration 4
30 ° C. of a solution of g / l in N, N-dimethylformamide
(Logarithmic viscosity at) was 1.50 dl / g.

<Thermolysis Decomposition Start Temperature> For thermogravimetric analysis (TGA) (using “TC10A” manufactured by METTLER CORPORATION), the temperature of the resin A was raised from 30 ° C. to 10 ° C./min in a nitrogen atmosphere to observe the weight change. When attached, it showed a thermal decomposition initiation temperature (weight reduction initiation temperature) of 425 ° C.

(Resin Composition A) 10 parts by weight of the above resin A was dissolved in 90 parts by weight of NMP (N-methyl-2-pyrrolidone) to obtain a resin composition A of the present invention.

(Electrode mixture composition) The above resin composition A40
96 parts by weight of carbon powder having an average particle size of 30 μm obtained by heat-treating natural graphite in a nitrogen atmosphere was added to the parts by weight, and 34 parts by weight of NMP was additionally mixed to prepare an electrode mixture of the present invention. Composition A was formed.

<Measurement of Hydrogen Fluoride Generation Amount> 0.5 g of the above electrode mixture composition A immediately after preparation was placed on a quartz boat,
Immediately in a tubular electric furnace heated to 150 ° C, air 100
It was heated for 30 minutes while flowing ml / min, and the generated gas was collected in the alkaline solution. Amount of hydrogen fluoride generated by quantifying the amount of alkali fluoride in the solution by ion chromatography (μg / g-electrode mixture composition)
Was found to be 20 μg / g.

(Electrode Structure A) The above electrode mixture composition A
A copper foil with a thickness of 10 μm (area 100 mm × 200 m
m) was evenly applied onto the m) so that the dry film thickness was about 100 μm, and dried at 130 ° C. for 25 minutes to obtain an electrode structure A of the present invention.

<Temperature Decomposition Start Temperature> The above electrode structure A was
When subjected to thermogravimetric analysis in the same manner as the above resin composition A,
It showed a thermal decomposition initiation temperature of 400 ° C.

<Peeling Strength> The electrode structure A separately formed in the same manner was immersed in propylene carbonate at 60 ° C. for 5 days. Then, the adhesion strength between the electrode layer and the copper foil before and after the immersion was measured by a 180 ° peeling test according to JIS K6845. As a result, the peel strength before and after immersion was 6.0 g / mm and 3.0 g / mm, respectively.

The outline of the above resin A and the evaluation results are collectively shown in Table 1 below together with the results of the resins obtained in the following Examples and Comparative Examples.

Example 2 (Resin B: VDF / GMA) 1036 g of ion-exchanged water, 41.7 g of methyl cellulose, 2.0 g of ethyl acetate, 3.2 g of isopropyl peroxydicarbonate (IPP) were placed in an autoclave having a content of 2 liters. 400 g of vinylidene fluoride and 4 g of glycidyl methacrylate were charged (vinylidene fluoride: glycidyl methacrylate (molar ratio) = 100: 0.45), and suspension polymerization was carried out at 28 ° C. for 27 hours.

After the completion of the polymerization, the polymer slurry was dehydrated, washed with water and dehydrated, and then dried at 80 ° C. for 20 hours to obtain a powdery resin B corresponding to the epoxy group-containing vinylidene fluoride copolymer of the present invention. And evaluated in the same manner as the resin A of Example 1.

Comparative Example 1 (Resin C: VDF homopolymer) In an autoclave having an internal capacity of 10 liters, 8192 g of ion-exchanged water, 111.3 g of methyl cellulose, 54.4 g of ethyl acetate, and 11.2 of isopropyl peroxydicarbonate (IPP).
g, vinylidene fluoride (VDF) 3200 g,
Suspension polymerization was carried out at 26 ° C. for 20 hours.

After the completion of the polymerization, the polymer slurry was dehydrated, washed with water and dehydrated, and then dried at 80 ° C. for 20 hours to obtain a powdered comparative resin C composed of a VDF homopolymer. Resin A of Example 1
It evaluated similarly to.

Comparative Example 2 (Resin D: VDF / MMM) 1040 g of ion-exchanged water, 0.8 g of methyl cellulose, 2.5 g of ethyl acetate, 4 g of diisopropyl peroxydicarbonate, vinylidene fluoride (VD) were placed in an autoclave having a content of 2 liters.
F) 396 g, maleic acid monomethyl ester (MM
M) 4.0 g was charged (VDF: MMM (molar ratio) = 1
Suspension polymerization was carried out at 28 ° C. for 47 hours. After the polymerization is completed, the polymer slurry is dehydrated, washed with water and then at 80 ° C.
Comparative resin D composed of a VDF / MMM copolymer was obtained by drying at 20 ° C. for 20 hours and evaluated in the same manner as the resin A of Example 1.

Comparative Example 3 (Resin E: VDF / AGE Copolymer) 1000 g of ion-exchanged water, 1.2 g of methyl cellulose, 5 g of dinormal propyl peroxydicarbonate (NPP), vinylidene fluoride were placed in an autoclave having a content of 2 liters. (VD
F) 397 g, allyl glycidyl ether (AGE) 3
g was charged (vinylidene fluoride: allyl glycidyl ether (molar ratio) = 100: 0.42), and suspension polymerization was carried out at 25 ° C. for 52 hours.

After completion of the polymerization, the polymer slurry was dehydrated, washed with water and dehydrated, and then dried at 80 ° C. for 20 hours to obtain VDF / AGE.
A comparative resin E made of a copolymer was obtained and evaluated in the same manner as the resin A of Example 1.

Comparative Example 4 (Resin F: VDF / AGE / MMM copolymer) Content 2
1000 liters of deionized water in a liter autoclave
g, 1.2 g of methyl cellulose, 4 g of dinormal propyl peroxydicarbonate (NPP), 396 g of vinylidene fluoride, 4.1 g of allyl glycidyl ether, 1.2 g of maleic acid monomethyl ester (vinylidene fluoride: allyl glycidyl ether: malein) Acid monomethyl ester (molar ratio) = 100: 0.57: 0.
15), suspension polymerization was carried out at 25 ° C. for 82 hours.

After the completion of the polymerization, the polymer slurry was treated in the same manner as in Example 1 to obtain a comparative resin F made of a VDF / AGE / MMM copolymer, which was evaluated in the same manner as the resin A in Example 1.

The results of the above Examples and Comparative Examples are summarized in Table 1 below.

[0069]

[Table 1]

[0070]

As can be understood from the results shown in Table 1 above, according to the present invention, good adhesiveness to a substrate such as a metal is exhibited, and improved heat resistance stability is exhibited. Epoxy group-containing vinylidene fluoride-based copolymer exhibiting excellent suitability as a binder for an element, an efficient production method thereof, and a resin composition containing the vinylidene fluoride-based copolymer as a binder, an electrode structure and A water-based electrochemical device is provided.

[Brief description of drawings]

FIG. 1 is a partially exploded perspective view of a non-aqueous solvent-based secondary battery that can be configured according to the present invention.

FIG. 2 is a partial cross-sectional view of an electrode structure used in the secondary battery.

FIG. 3 is a cross-sectional view of an example of a non-aqueous solvent-based electric double layer capacitor configured according to the present invention.

[Explanation of symbols]

1: Positive electrode 2: Negative electrode 3, 23: Separator 5: casing (5a: bottom, 5b: rim) 6, 27: Gasket 7: Safety valve 8: Top plate 10, 20a, 20b: Electrode structure 11, 21a, 21b: Current collector 12a, 12b, 22a, 22b: electrode mixture layer 24: Capacitor cap 25: Capacitor can 26: Non-aqueous electrolyte

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H01M 4/02 H01M 4/62 Z 4/62 10/40 Z 10/40 H01G 9/00 301D F term ( Reference) 4J002 CD191 DE096 DG026 FD206 4J036 AK10 DB15 DC02 DC18 FA02 JA07 4J100 AC24P AL10Q CA04 FA21 JA43 5H029 AJ14 AK03 AL06 AM03 AM07 BJ02 BJ03 BJ12 BJ14 CJ02 CJ08 DJ08 EJ12 5H050 GA24 FA02 FA11 CA02 FA17 FA02 FA11 CA02 FA17 FA02 FA11 CA02 FA11

Claims (8)

[Claims] 1. 100 mol of vinylidene fluoride monomer,
An epoxy group-containing vinylidene fluoride-based copolymer, which is a copolymer with 0.1 to 5.0 moles of an acrylic vinyl monomer containing at least an epoxy group. 2. The epoxy vinyl monomer containing an epoxy group comprises glycidyl (meth) acrylate, 2-methylglycidyl (meth) acrylate, 2-ethylglycidyl (meth) acrylate and 1-methylglycidyl (meth) acrylate. Claim 1 selected from the group
The epoxy group-containing vinylidene fluoride-based copolymer according to 1. 3. 100 mol of vinylidene fluoride monomer,
2. A suspension of polymerization of a monomer mixture containing at least 0.1 to 5.0 moles of an acrylic vinyl monomer containing an epoxy group, using water as a dispersion medium.
Or the method for producing an epoxy group-containing vinylidene fluoride-based copolymer as described in 2 above. 4. A resin composition obtained by dissolving the vinylidene fluoride-based copolymer according to claim 1 or 2 in an organic solvent. 5. An electrode mixture composition obtained by adding a powder electrode material to the resin composition according to claim 4. 6. A non-aqueous electrochemical device comprising a collector substrate on which a porous electrode layer comprising the epoxy group-containing vinylidene fluoride copolymer according to claim 1 and a powder electrode material is formed. Electrode structure. 7. A non-aqueous solvent system comprising a positive electrode, a negative electrode, and a non-aqueous electrolytic solution disposed between the positive electrode and the negative electrode, at least one of the positive electrode and the negative electrode comprising the electrode structure according to claim 6. Next battery. 8. An electric double layer capacitor in which a non-aqueous electrolyte is arranged between a pair of electrode structures each having the structure according to claim 7.