JP2016177925A - Composition for forming secondary battery electrode, secondary battery electrode, and secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composition for forming an electrode, excellent in dispersibility of an active material and a conductive assistant, and further to provide a secondary battery excellent in long-term charge/discharge cycle characteristics.SOLUTION: A composition for forming a secondary battery electrode contains: a polymer dispersant (A) having a structural unit (a-1) represented by general formula (1) and/or general formula (2); and a carbon material (B) as a conductive assistant. In addition, the polymer dispersant (A) has a degree of polymerization of 10 or more and 350 or less.SELECTED DRAWING: None

Description

  The present invention relates to a composition for forming a secondary battery electrode for producing an electrode constituting a secondary battery, a secondary battery electrode and a secondary battery obtained using the same. It is related with the composition for secondary battery electrode formation for manufacturing a lithium secondary battery, the electrode for secondary batteries, and a secondary battery especially.

  In recent years, small portable electronic devices such as digital cameras and mobile phones have always been required to reduce weight and minimize volume, and the batteries to be mounted are light and small. A battery having a large discharge capacity is required. In addition, large non-aqueous electrolyte secondary batteries are demanded in place of conventional lead-acid batteries in large-sized secondary batteries for automobiles and the like.

  In order to meet these demands, lithium secondary batteries are being actively developed. A positive electrode and a negative electrode are used as electrodes of the lithium secondary battery. The positive electrode is obtained by fixing an electrode mixture composed of a positive electrode active material containing lithium ions, a conductive additive, an organic binder, and the like to the surface of a current collector of metal foil. On the other hand, the negative electrode is obtained by fixing an electrode mixture composed of a negative electrode active material from which lithium ions can be inserted and removed, a conductive additive, an organic binder, and the like to the surface of a current collector of metal foil.

  In general, lithium transition metal composite oxides such as lithium cobaltate and lithium manganate are used as the positive electrode active material, but these have low electronic conductivity and have sufficient battery performance when used alone. I can't get it. Therefore, an attempt has been made to improve the conductivity by adding a material having excellent conductivity as a conductive additive and reduce the internal resistance of the electrode. In general, carbon materials such as carbon black (for example, acetylene black) and graphite (graphite) have been studied.

  On the other hand, graphite is usually used as the negative electrode active material. Although graphite itself has conductivity, it is known that charge and discharge characteristics are improved by adding carbon black such as acetylene black as a conductive aid together with graphite. This is because the graphite particles generally used are large, so if graphite alone is used, the gap when filled in the electrode layer will increase. However, when carbon black is used as a conductive additive, fine carbon black is used. This is probably because the contact area is increased by filling the gaps between the graphite particles and the electrical conductivity is increased. However, in this case as well, the conductive effect is reduced if the dispersion of the conductive aid is insufficient.

As described above, reducing the internal resistance of the electrode is one of the very important elemental technologies for improving the efficiency of discharging with a large current and charging / discharging.
However, a carbon material (conducting aid) having excellent conductivity has a strong cohesive force, and it is difficult to uniformly mix and disperse in a slurry for forming an electrode mixture of a lithium secondary battery, and is a conducting aid. When the dispersibility and particle size of the carbon material are insufficiently controlled, the internal resistance of the electrode cannot be reduced because a uniform conductive network is not formed, and as a result, the lithium transition metal composite oxide or graphite that is the active material Thus, there arises a problem that the battery performance is deteriorated due to insufficient performance. In addition, if the dispersion of the conductive additive in the electrode mixture is insufficient, a resistance distribution occurs on the electrode plate due to partial aggregation, and current is concentrated when used as a battery. Problems such as heat generation and accelerated deterioration may occur.

  In addition, the slurry for forming an electrode mixture tends to decrease in dispersibility and increase in particle size over time. An increase in the particle size leads to a decrease in coating properties, causing problems such as a decrease in battery productivity. Therefore, it is necessary to maintain the dispersibility and particle size of the carbon material.

  In the lithium secondary battery, the dispersion of the carbon material, which is a conductive auxiliary agent, is considered as one of the important technologies in the lithium secondary battery, and several proposals have been made. For example, Patent Document 1 describes an example in which an organic dye derivative having an acidic functional group or a triazine derivative having an acidic functional group is used as a dispersing agent when dispersing a carbon material that is a conductive additive. Patent Document 2 describes an example in which a polyvinyl acetal resin is used as a dispersant. According to these methods, it is possible to prepare a dispersion and mixture slurry of a carbon material excellent in dispersion stability, and the improvement in battery performance which is considered to be caused by the dispersion effect of the carbon material is achieved. In order to further improve the battery performance and to stably produce the battery, further stability over time of the dispersion is required.

International Publication No. 2008/108360 JP 2011-184664 A

  The problem to be solved by the present invention is to form a secondary battery electrode that is excellent in the dispersion stability of the conductive assistant and the dispersion stability of the composite slurry in the composition for forming a secondary battery electrode containing the conductive assistant. It is to provide a composition. Moreover, it is providing the electrode and secondary battery which were excellent in charging / discharging cycling characteristics by using this.

  As a result of intensive studies to solve the above problems, the present inventors have used a polymer dispersant (A) as a dispersant to disperse a carbon material as a conductive additive. The present inventors have found that a composition for forming a secondary battery electrode (dispersion and mixture slurry) that is excellent in stability, excellent in electrode adhesion, and effective in improving the performance of a secondary battery can be obtained. Is.

［Ｒ¹は、水素またはメチル基を表す。Ｒ²は、置換基を有していてもよいアルキレン基、置換基を有していてもよいアルケニレン基、置換基を有していてもよいアリーレン基、または置換基を有していてもよいヘテロアリーレン基を表す。］

一般式（２）

［Ｒ¹は、水素またはメチル基を表す。Ｒ³は、置換基を有していてもよいアルキレン基、置換基を有していてもよいアリーレン基、または置換基を有していてもよいヘテロアリーレン基を表し、Ｒ⁴は、置換基を有していてもよいアルキレン基、置換基を有していてもよいアリーレン基、または置換基を有していてもよいヘテロアリーレン基を表す。］ That is, the embodiment of the present invention includes a polymer dispersant (A) having a structural unit (a-1) represented by the following general formula (1) and / or (2), and a carbon material ( B) and a composition for forming a secondary battery electrode.
General formula (1)

[R ¹ represents hydrogen or a methyl group. R ² may have an alkylene group which may have a substituent, an alkenylene group which may have a substituent, an arylene group which may have a substituent, or may have a substituent. Represents a heteroarylene group. ]

General formula (2)

[R ¹ represents hydrogen or a methyl group. R ³ represents an alkylene group which may have a substituent, an arylene group which may have a substituent, or a heteroarylene group which may have a substituent, and R ⁴ represents a substituent. Represents an alkylene group which may have a substituent, an arylene group which may have a substituent, or a heteroarylene group which may have a substituent. ]

  In addition, an embodiment of the present invention relates to the composition for forming a secondary battery electrode, wherein the polymer dispersant (A) has a polymerization degree of 10 or more and 350 or less.

  Further, in an embodiment of the present invention, the composition for forming a secondary battery electrode, wherein the content of the polymer dispersant (A) is 0.01 to 7.5% by mass with respect to the carbon material (B). About.

  Further, the embodiment of the present invention further includes an organic dye derivative having an acidic functional group, an organic dye derivative having a basic functional group, a triazine derivative having an acidic functional group (except for an organic dye derivative), and a basic functional group. The present invention relates to the composition for forming a secondary battery electrode, comprising one or more derivatives (D) selected from the group consisting of triazine derivatives (excluding organic dye derivatives).

Moreover, the embodiment of this invention is related with the said composition for secondary battery electrode formation which further contains a solvent (E) and a binder (F).
Furthermore, an embodiment of the present invention is the composition for forming a secondary battery electrode further comprising an active material (G), wherein the average particle diameter of the active material (G) / the dispersion of the carbon material (B). It is related with the said composition for secondary battery electrode formation whose ratio of a particle size (D50) is 2-100.

  In addition, an embodiment of the present invention relates to an electrode for a secondary battery, which is an electrode having a composite material layer on a current collector, wherein the composite material layer is formed of the composition for forming a secondary battery electrode.

  An embodiment of the present invention is a secondary battery comprising a positive electrode having a positive electrode mixture layer on a current collector, a negative electrode having a negative electrode mixture layer on the current collector, and an electrolyte. The present invention relates to a secondary battery in which at least one of a positive electrode and a negative electrode is the secondary battery electrode.

  According to a preferred embodiment of the present invention, it is possible to provide a composition for forming a secondary battery electrode that is excellent in dispersibility of an active material and a conductive additive. Moreover, the electrode and the secondary battery using the electrode forming composition of the present invention can improve charge / discharge cycle characteristics. This is not only because a dispersion of carbon material particles and a mixture slurry having excellent dispersion stability were prepared by using a polymer dispersant, but also by using a polymer dispersant, an active material ( This is considered to cause a uniform and strong interaction between G) and the carbon material (B). Therefore, the composition for forming a secondary battery electrode of the present invention can be used for a lithium secondary battery, a nickel hydride secondary battery, a nickel cadmium secondary battery, an alkaline manganese battery, a lead battery, a fuel cell, a capacitor, and the like. In particular, it is suitable for use in a lithium secondary battery.

<Polymer dispersant (A)>
Hereinafter, the present invention will be described in detail.
The polymer dispersant (A) used in the present invention contains the structural unit (a-1) as an essential component and may contain the structural unit (a-2). There is no restriction on the arrangement of the structural units, and the arrangement of the structural units may be random.

The structural unit (a-1) is represented by the following general formula (1) and / or general formula (2).

［Ｒ¹は、水素またはメチル基を表す。Ｒ²は、置換基を有していてもよいアルキレン基、置換基を有していてもよいアルケニレン基、置換基を有していてもよいアリーレン基、または置換基を有していてもよいヘテロアリーレン基を表す。］

General formula (1)

[R ¹ represents hydrogen or a methyl group. R ² may have an alkylene group which may have a substituent, an alkenylene group which may have a substituent, an arylene group which may have a substituent, or may have a substituent. Represents a heteroarylene group. ]

［Ｒ¹は、水素またはメチル基を表す。
Ｒ³は、置換基を有していてもよいアルキレン基、置換基を有していてもよいアリーレン基、または置換基を有していてもよいヘテロアリーレン基を表し、
Ｒ⁴は、置換基を有していてもよいアルキレン基、置換基を有していてもよいアルケニレン基、置換基を有していてもよいアリーレン基、または置換基を有していてもよいヘテロアリーレン基を表す。］ General formula (2)

[R ¹ represents hydrogen or a methyl group.
R ³ represents an alkylene group that may have a substituent, an arylene group that may have a substituent, or a heteroarylene group that may have a substituent,
R ⁴ may have an alkylene group that may have a substituent, an alkenylene group that may have a substituent, an arylene group that may have a substituent, or may have a substituent. Represents a heteroarylene group. ]

R ¹ in the general formula (1) of the polymer dispersant (A) is hydrogen or a methyl group, preferably hydrogen.

R ² in the general formula (1) of the polymer dispersant (A) may be an alkylene group which may have a substituent, an alkenylene group which may have a substituent, or a substituent. It is a good arylene group or a heteroarylene group which may have a substituent. Preferably, an alkylene group which may have a substituent, an alkenylene group which may have a substituent, or an arylene group which may have a substituent, more preferably a substituent. An alkylene group which may be substituted, or an arylene group which may have a substituent.

As the alkylene group in R ² of the general formula (1), a linear alkylene group (methylene, dimethylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, dodecamethylene group, etc.), a branched alkylene group (2, 4, 4 '-Trimethylhexamethylene group), cyclic alkylene group (1,2-cyclopentyl group, 1,3-cyclopentyl group, 1,2-cyclohexyl group, 1,3-cyclohexyl group, 1,4-cyclohexyl group, methyl- 2,4-cyclohexyl group, methyl-2,6-cyclohexyl group, etc.), preferably an alkylene group having 10 or less carbon atoms, more preferably a linear or branched chain having 4 or less carbon atoms. An alkylene group, particularly preferably a dimethylene group.

Examples of the alkenylene group in R ² of the general formula (1) include an ethynylene group, a propenylene group, and a butenylene group, and preferably an alkenylene group having 2 to 15 carbon atoms.

As the arylene group in R ² of the general formula (1), a phenylene group (1,2-phenylene, 1,3-phenylene, 1,4-phenylene, 2-methyl-1,3-phenylene, 4-methyl-1 , 3-phenylene, 1,3-dimethylphenylene, 1,4-dimethylphenylene, and 1,4-diethylphenylene groups), naphthylene groups (1,2-naphthylene, 1,3-naphthylene, 1,4-naphthylene, 1,5-naphthylene, 1,6-naphthylene, 1,7-naphthylene, 1,8-naphthylene, 2,3-naphthylene, and 2,6-naphthylene groups), preferably having 10 or less carbon atoms. An arylene group, more preferably a phenylene group, and particularly preferably a 1,2-phenylene group.

Examples of the heteroarylene group in R ² of the general formula (1) include a pyridylene group, a quinolylene group, and an acridinylene group, and a heteroarylene group having 10 or less carbon atoms is preferable.

When R ^{3 in the} general formula (1) has a substituent, examples of the group that can be substituted include a substituent selected from a halogen atom, a hydroxyl group, a carboxyl group, and the like. Examples of the halogen atom include fluorine, chlorine, bromine and iodine.

R ³ in the general formula (2) of the polymer dispersant (A) has an alkylene group which may have a substituent, an arylene group which may have a substituent, or a substituent. It is also a good heteroarylene group. An unsubstituted alkylene group, an unsubstituted arylene group, or an unsubstituted heteroarylene group is preferable, and an unsubstituted alkylene group is more preferable.

The alkylene group which may have a substituent in R ³ of the general formula (2) has the same meaning as the alkylene group of R ² in the general formula (1), preferably an alkylene group having 1 to 10 carbon atoms. And more preferably a linear alkylene group having 2 to 4 carbon atoms.

The arylene group which may have a substituent in R ³ of the general formula (2) has the same meaning as the arylene group of R ² in the general formula (1).

The heteroarylene group which may have a substituent in R ³ of the general formula (2) has the same meaning as the heteroarylene group of R ² in the general formula (1).

When R ^{3 in the} general formula (2) has a substituent, the group that can be substituted is the same as the group that can be substituted in R ² in the general formula (1).

R ⁴ in the general formula (2) of the polymer dispersant (A) may be an alkylene group which may have a substituent, an alkenylene group which may have a substituent, or a substituent. It is a good arylene group or a heteroarylene group which may have a substituent.

The alkylene group represented by R ⁴ in the general formula (2) of the polymer dispersant (A) has the same meaning as the alkylene group represented by R ² in the general formula (1).

The alkenylene group in R ⁴ of the general formula (2) of the polymer dispersant (A) has the same meaning as the alkenylene group of R ² in the general formula (1).

The arylene group in R ⁴ in the general formula (2) of the polymer dispersant (A) has the same meaning as the arylene group in R ² in the general formula (1).

The heteroarylene group in R ⁴ in the general formula (2) of the polymer dispersant (A) has the same meaning as the heteroarylene group in R ² in the general formula (1).

When R ^{4 in the} general formula (2) has a substituent, the group that can be substituted is the same as the group that can be substituted in R ² in the general formula (1).

  The structural unit (a-2) in the polymer dispersant (A) is the structural unit (a-2-1) and / or the structural unit (a-2-2).

  The structural unit (a-2-1) indicates a portion derived from a monomer that is a raw material of the copolymer. The method for obtaining the structural unit (a-2-1) is not particularly limited, and examples thereof include a method of copolymerizing monomers that form the structural unit (a-2-1).

  Although it does not specifically limit as a monomer which forms a structural unit (a-2-1), The monomer which has an aromatic ring, the monomer which has a carboxyl group or an amino group, the monomer which has a hydroxyl group, other And a monomer having an aromatic ring, a monomer having a carboxyl group, a monomer having a hydroxyl group, and other monomers.

First, a monomer having an aromatic ring will be described.
Although it does not specifically limit as a monomer which has an aromatic ring, Styrene, (alpha) -methylstyrene, or benzyl (meth) acrylate can be illustrated.

Next, a monomer having a carboxyl group or an amino group will be described.
The monomer having a carboxyl group is not particularly limited, but maleic acid, fumaric acid, itaconic acid, citraconic acid, or an alkyl or alkenyl monoester thereof, phthalic acid β- (meth) acryloxyethyl monoester, isophthalic acid Acid β- (meth) acryloxyethyl monoester, terephthalic acid β- (meth) acryloxyethyl monoester, succinic acid β- (meth) acryloxyethyl monoester, acrylic acid, methacrylic acid, crotonic acid, cinnamic acid , Etc. can be illustrated. In particular, methacrylic acid and acrylic acid are preferable.
The monomer having an amino group is not particularly limited, and examples thereof include dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, methylethylaminoethyl (meth) acrylate, dimethylaminostyrene, diethylaminostyrene and the like. . These structural units having a carboxyl group or an amino group may be used alone or in combination of two or more, and may be a combination of a structural unit having a carboxyl group and a structural unit having an amino group. These carboxyl groups or amino groups may be neutralized.

  Next, the monomer having a hydroxyl group will be described. Although it does not specifically limit as a monomer which has a hydroxyl group, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, glycerol mono (meth) acrylate, 4-hydroxy Examples thereof include styrene and allyl alcohol.

  Next, other monomers will be described. Examples of other monomers include alkyl (meth) acrylates, perfluoroalkylalkyl (meth) acrylates, perfluoroalkyl group-containing vinyl monomers, or silanol group-containing vinyl compounds and derivatives thereof.

  Examples of the alkyl-based (meth) acrylate include alkyl (meth) acrylates having 1 to 22 carbon atoms such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and butyl (meth) acrylate.

  Perfluoroalkylalkyl (meth) acrylates include perfluoromethylmethyl (meth) acrylate, perfluoroethylmethyl (meth) acrylate, 2-perfluorobutylethyl (meth) acrylate, and 2-perfluorohexylethyl (meth). Examples include perfluoroalkylalkyl (meth) acrylates having a C1-20 perfluoroalkyl group such as acrylate.

  Examples of the perfluoroalkyl group-containing vinyl monomer include perfluorobutylethylene, perfluorohexylethylene, perfluorooctylethylene, and perfluorodecylethylene.

  Silanol group-containing vinyl compounds and their derivatives include vinyl trichlorosilane, vinyl tris (βmethoxyethoxy) silane, vinyltriethoxysilane, γ- (meth) acryloxypropyltrimethoxysilane and other silanol group-containing vinyl compounds and their derivatives, etc. Can be mentioned.

  A plurality of types of monomers that form the structural unit (a-2-1) may be used, and the arrangement may be random.

  The structural unit (a-2-2) is vinyl alcohol, vinyl acetate, or vinyl acetal. The method for obtaining these is not particularly limited, and examples thereof include a method of copolymerizing monomers that form the structural unit (a-2-2).

  Vinyl alcohol in the structural unit (a-2-2) has a structure represented by the formula (3).

Formula (3)

  Vinyl acetate in the structural unit (a-2-2) has a structure represented by the formula (4).

Formula (4)

  The vinyl acetal in the structural unit (a-2-2) has a structure represented by the general formula (5).

［Ｒ^Xは、メチル基、エチル基、または、ブチル基を表す。］ General formula (5)

[R ^X represents a methyl group, an ethyl group, or a butyl group. ]

  As the structural unit (a-2-2), a plurality of types may be used from vinyl alcohol, vinyl acetate, or vinyl acetal, and the arrangement may be random.

  When the polymer dispersant (A) includes the structure represented by the general formula (1) as the structural unit (a-1), the structural unit (a-2) is the structural unit (a-2-2). It is preferable that it is the structure mentioned.

  When the polymer dispersant (A) includes the structure represented by the general formula (2) as the structural unit (a-1), the structural unit (a-2) is the structural unit (a-2-1). It is preferable that the structure is mentioned.

  Moreover, the polymerization degree of a polymer dispersing agent (A) is 10-1000, 10-350 are preferable and 10-200 are more preferable.

  The degree of polymerization of the polymer dispersant (A) is an average value of the number of repeating units constituting the polymer dispersant (A). The degree of polymerization can be determined from the produced polymer dispersant (A) by the following method.

<Degree of polymerization>
The degree of polymerization is a value obtained by dividing the number average molecular weight (Mn) of the copolymer by the average molecular weight of the structural unit of the polymer.
When the monomer 1 having the molecular weight M1 and the monomer 2 having the molecular weight M2 are polymerized at a mass ratio of W1 and W2, respectively, the average molecular weight of the copolymer monomer is (W1-W2). / (W1 / M1 + W2 / M2).

  Examples of the method for measuring the number average molecular weight (Mn) include using gel polystyrene (GPC) calibrated with a standard polystyrene having a known peak molecular weight and calibrated with the standard.

  The method for obtaining the polymer dispersant (A) is not particularly limited. For example, the polymer dispersant (A) may be reacted with an acid anhydride having a partial skeleton of the structural unit (a-1). The method obtained as a reaction solution (Ax) containing A) is mentioned.

When the acid anhydride is reacted as a method for obtaining the polymer dispersant (A), it is preferable to confirm whether or not the raw acid anhydride is reacted. Examples of the method for calculating the reaction rate include a method of obtaining the reaction rate from the acid anhydride value (Ax) of the product and the acid anhydride value (Ay) of the raw material.
Reaction rate = 1− (Ax / Ay)

The acid anhydride value as used herein means that a mixed solution of octylamine, 1,4-dioxane and water is added to a sample to dissolve and react, and then excess octylamine is added to 0.02M perchloric acid, 1,4- It is a value calculated by the following formula after titration with a mixed solution of dioxane.
Acid anhydride value (mgKOH / g) = [0.02 (mol / L) × (blank titration−sample titration) (mL) × F] / sample solid content (g) × 56.11 (mmol / g)
F: 0.02 mol / L perchloric acid titer

As a method for obtaining the polymer dispersant (A), when an acid anhydride is reacted with a polymer having a hydroxyl group, the reaction of the acid anhydride and the hydroxyl group causes the polymer to undergo a polymerization reaction and the degree of polymerization does not change. . Therefore, the degree of polymerization of the polymer dispersant (A) can be treated as being equal to the degree of polymerization of the polymer having a hydroxyl group.
The degree of polymerization of the polymer having a hydroxyl group can be calculated from the same measurement method as the degree of polymerization of the polymer dispersant (A).

<Carbon material (B)>
The carbon material (B) is not particularly limited as long as it is a carbon material having conductivity, but graphite, carbon black, conductive carbon fiber (carbon nanotube, carbon nanofiber, carbon fiber), fullerene, etc. It can be used alone or in combination of two or more. From the viewpoint of conductivity, availability, and cost, it is preferable to use carbon black.

  Carbon black is a furnace black produced by continuously pyrolyzing a gas or liquid raw material in a reactor, especially ketjen black using ethylene heavy oil as a raw material. Channel black that has been rapidly cooled and precipitated, thermal black obtained by periodically repeating combustion and thermal decomposition using gas as a raw material, and particularly various types such as acetylene black using acetylene gas as a raw material alone or 2 More than one type can be used in combination. Ordinarily oxidized carbon black, hollow carbon and the like can also be used.

  The oxidation treatment of carbon is performed by treating carbon at a high temperature in the air or by secondary treatment with nitric acid, nitrogen dioxide, ozone, etc., for example, such as phenol group, quinone group, carboxyl group, carbonyl group. This is a treatment for directly introducing (covalently bonding) an oxygen-containing polar functional group to the carbon surface, and is generally performed to improve the dispersibility of carbon. However, since it is common for the conductivity of carbon to fall, so that the introduction amount of a functional group increases, it is preferable to use the carbon which has not been oxidized.

As the specific surface area of the carbon black used increases, the number of contact points between the carbon black particles increases, which is advantageous in reducing the internal resistance of the electrode. Specifically, the specific surface area (BET) determined from the amount of nitrogen adsorbed is 20 m ² / g or more and 1500 m ² / g or less, preferably 50 m ² / g or more and 1500 m ² / g or less, more preferably 100 m ^2. / G or more and 1500 m ² / g or less are desirable. If carbon black having a specific surface area of less than 20 m ² / g is used, it may be difficult to obtain sufficient conductivity, and carbon black of more than 1500 m ² / g may be difficult to obtain from commercially available materials. is there.

  Further, the particle size of the carbon black to be used is preferably 0.005 to 1 μm, particularly preferably 0.01 to 0.2 μm in terms of primary particle size. However, the primary particle diameter here is a value obtained by averaging the particle diameters measured with an electron microscope.

  Examples of commercially available carbon black include Toka Black # 4300, # 4400, # 4500, # 5500 (Tokai Carbon Co., Furnace Black), Printex L and the like (Degussa Co., Furnace Black), Raven 7000, 5750, 5250, 5000 ULTRA III, 5000 ULTRA, etc., Conductex SC ULTRA, Conductex 975 ULTRA, etc. (Columbian manufactured by Furnace Black), # 2350, # 2400B, # 30050B, # 3030B, # 3230B, # 3350B, # 3400B, # 5400B, etc. (Manufactured by Chemical Co., Furnace Black), MONARCH1400, 1300, 900, VulcanXC-72R, BlackPearls2000, etc. Furnace Black), Ensaco 250G, Ensaco 260G, Ensaco 350G, SuperP-Li, (manufactured by TIMCAL), Ketjen Black EC-300J, EC-600JD (manufactured by Akzo), Denka Black, Denka Black HS-100, FX-35 (Electrochemistry) (Industry company make, acetylene black) etc. are mentioned, However, It is not limited to these. Examples of graphite include, but are not limited to, natural graphite such as artificial graphite, flake graphite, massive graphite, and earthy graphite, and two or more kinds may be used in combination.

  As the conductive carbon fibers, those obtained by firing from petroleum-derived raw materials are preferable, but those obtained by firing from plant-derived raw materials can also be used. For example, VGCF manufactured by Showa Denko KK manufactured with petroleum-derived raw materials can be used.

<Derivative (D)>
The derivative (D) used in the present invention will be described. The derivative (D) used in the present invention is an organic dye derivative having an acidic functional group, an organic dye derivative having a basic functional group, a triazine derivative having an acidic functional group, and a triazine derivative having a basic functional group. One or more derivatives selected.
Among the derivatives having an acidic functional group, in particular, triazine derivatives having an acidic functional group represented by the following general formula (9) (excluding those containing organic dye derivatives), or acidic compounds represented by the general formula (12) Organic dye derivatives having a functional group are preferred. First, the triazine derivative having an acidic functional group represented by the general formula (9) will be described.

General formula (9)

[X ¹ is, -NH binding group to R ⁵ as left -, - O -, - CONH -, - SO 2 NH -, - CH 2 NH -, - CH 2 NHCOCH 2 NH- or -X ³ - Y—X ⁴ —, X ² and X ⁴ each independently represent —NH— or —O—, and X ³ represents —CONH—, —SO ₂ NH with the bonding group to R ⁵ as the left end. —, —CH ₂ NH—, —NHCO— or —NHSO ₂ —, and Y represents an alkylene group which may have a substituent, an alkenylene group which may have a substituent or a substituent. And Z represents —SO ₃ M, —COOM, —P (O) (— OM) _2, or —O—P (O) (— OM) ₂ , and M represents 1 to 3 represents one equivalent of valence of the cation, Q ^{is, -O-R 6, -NH-} R 6, a halogen group, a -X ¹ -R ⁵ or -X ² -Y-Z Table , R ⁶ represents a hydrogen atom, which may have a an optionally substituted alkyl group or an optionally substituted alkenyl group. u represents an integer of 1 to 4. R ⁵ represents a heterocyclic residue which may have a substituent, an aromatic ring residue which may have a substituent, or a group represented by the following general formula (10). ]

General formula (10)

[X ⁵ represents —NH— or —O—, and X ⁶ and X ⁷ each independently represent —NH—, —O—, —CONH—, —SO ₂ with the binding group to the triazine ring as the left end. NH—, —CH ₂ NH— or —CH ₂ NHCOCH ₂ NH—, wherein R ⁷ and R ⁸ each independently have a heterocyclic residue which may have a substituent, or a substituent. May represent an aromatic ring residue or —Y—Z, and Y and Z have the same meanings as Y and Z in formula (9). ]

In the above, examples of the heterocyclic residue and aromatic ring residue in R ⁵ , R ⁷ , or R ⁸ include thiophene, furan, pyridine, pyrazole, pyrrole, imidazole, isoindoline, isoindolinone, and benzine. Examples include heterocyclic residues such as imidazolone, benzthiazole, benztriazole, indole, quinoline, carbazole and acridine, and aromatic ring residues such as benzene, naphthalene, anthracene, fluorene, phenanthrene and anthraquinone. In particular, a heterocyclic residue containing any one of S, N, and O heteroatoms is preferable because it exhibits an effect of excellent dispersibility.

  Y in the general formula (9) and the general formula (10) represents an alkylene group, an alkenylene group or an arylene group which may have a substituent, but preferably has 20 or less carbon atoms, and more preferably has 10 or less carbon atoms. . Particularly preferred embodiments include an optionally substituted phenylene group, biphenylene group, naphthylene group or an alkylene group which may have a side chain having 10 or less carbon atoms.

Preferred embodiments of the alkyl group which may have a substituent and the alkenyl group which may have a substituent in R ⁶ are those having 20 or less carbon atoms. More preferably, an alkyl group which may have a side chain having 10 or less carbon atoms is exemplified. Here, the alkyl group having a substituent and the alkenyl group having a substituent are a group in which a hydrogen atom of an alkyl group or an alkenyl group is substituted with a halogen group such as a fluorine atom, a chlorine atom or a bromine atom, a hydroxyl group or a mercapto group. Can be mentioned.

M represents one equivalent of 1 to 3 valent cations, for example, a hydrogen ion (proton), a metal cation, or a quaternary ammonium cation. Moreover, when it has two or more M in the structure (one molecule) of a dispersing agent, M may be only one kind of a proton, a metal cation, and a quaternary ammonium cation, and may be a combination of two or more kinds.
Examples of the metal cation include metal cations such as lithium, sodium, potassium, calcium, barium, magnesium, aluminum, nickel, and cobalt.
The quaternary ammonium cation is a single compound having a structure represented by the general formula (11) or a mixture.

Formula (11)

[R ⁹ , R ¹⁰ , R ¹¹ , or R ¹² each independently has a hydrogen atom, an alkyl group that may have a substituent, an alkenyl group that may have a substituent, or a substituent. Represents an aryl group which may be substituted. ]

R ⁹ , R ¹⁰ , R ¹¹ , or R ¹² may be the same or different. Moreover, when R < ⁹ >, R < ¹⁰ >, R < ¹¹ > or R < ¹² > has a carbon atom, carbon number is 1-40, Preferably it is 1-30, More preferably, it is 1-20.

  Specific examples of the quaternary ammonium cation include dimethylammonium, trimethylammonium, diethylammonium, triethylammonium, hydroxyethylammonium, dihydroxyethylammonium, 2-ethylhexylammonium, dimethylaminopropylammonium, laurylammonium, stearylammonium and the like. However, it is not limited to these.

［Ｘ⁸は、直接結合、或いは、Ｒ¹³への結合基を左端として−ＮＨ−、−Ｏ−、−ＣＯＮＨ−、−ＳＯ₂ＮＨ−、−ＣＨ₂ＮＨ−、−ＣＨ₂ＮＨＣＯＣＨ₂ＮＨ−、−Ｘ⁹−Ｙ−または−Ｘ⁹−Ｙ−Ｘ¹⁰−を表し、Ｘ⁹はＲ¹³への結合基を左端として、−ＣＯＮＨ−、−ＳＯ₂ＮＨ−、−ＣＨ₂ＮＨ−、−ＮＨＣＯ−または−ＮＨＳＯ₂−を表し、Ｘ¹⁰は、−ＮＨ−または−Ｏ−を表し、Ｙは、置換基を有してもよいアルキレン基、置換基を有してもよいアルケニレン基または置換基を有してもよいアリーレン基を表し、Ｚは、−ＳＯ₃Ｍ、−ＣＯＯＭ、−Ｐ（Ｏ）（−ＯＭ）₂または−Ｏ−Ｐ（Ｏ）（−ＯＭ）₂を表し、Ｍは１〜３価のカチオンの一当量を表し、Ｒ¹³は、有機色素残基を表し、ｖは、１〜４の整数を表す。］ Next, an organic dye derivative having an acidic functional group represented by the general formula (12) will be described.
Formula (12)

[X ⁸ is a direct bond, or, -NH binding group to R ¹³ as left -, - O -, - CONH -, - SO 2 NH -, - CH 2 NH -, - CH 2 NHCOCH 2 NH- , —X ⁹ —Y— or —X ⁹ —Y—X ¹⁰ —, wherein X ⁹ is —CONH—, —SO ₂ NH—, —CH ₂ NH—, —, with the bonding group to R ¹³ as the left end. NHCO— or —NHSO ₂ — is represented, X ¹⁰ represents —NH— or —O—, Y represents an alkylene group which may have a substituent, an alkenylene group which may have a substituent, or a substituent Represents an arylene group which may have a group, Z represents —SO ₃ M, —COOM, —P (O) (— OM) ₂ or —O—P (O) (— OM) ₂ ; Represents one equivalent of a 1 to 3 valent cation, R ¹³ represents an organic dye residue, and v represents an integer of 1 to 4. ]

Examples of the organic dye residue of R ¹³ include diketopyrrolopyrrole dyes, azo dyes such as azo, disazo, polyazo, phthalocyanine dyes, anthraquinones, diaminodianthraquinones, anthrapyrimidines, flavantrons, anthanthrones, indans. Anthraquinone dyes such as throne, pyranthrone, violanthrone, quinacridone dyes, dioxazine dyes, perinone dyes, perylene dyes, thioindigo dyes, isoindoline dyes, isoindolinone dyes, quinophthalone dyes, selenium dyes Residues such as dyes and metal complex dyes may be mentioned. In particular, in order to increase the effect of suppressing the short circuit of the battery due to metal, it is preferable to use an organic dye residue that is not a metal complex dye, among which an azo dye, a diketopyrrolopyrrole dye, a metal-free phthalocyanine dye, Quinacridone dyes and dioxazine dye residues are preferred because they exhibit excellent dispersibility.

  M in the general formula (12) has the same meaning as M in the general formula (9).

  A method for synthesizing the derivative (D) used in the present invention is not particularly limited, and examples thereof include Japanese Patent Publication No. 39-28884, Japanese Patent Publication No. 45-11026, Japanese Patent Publication No. 45-29755, It can be synthesized by the methods described in JP-B-64-5070, JP-A-2004-217842, and the like.

  In the present invention, it is considered that the derivative (D) mainly functions as a dispersant and also plays a role for creating an electrode film state suitable for improving battery performance.

<Basic pigment derivative>
Among basic pigment derivatives, in particular, triazine derivatives having a basic functional group represented by the following general formula (13) (excluding those containing organic dye derivatives), or bases represented by the general formula (18) Organic dye derivatives having a functional group are preferred. First, the triazine derivative having a basic functional group represented by the general formula (13) will be described.

Formula (13)

X ¹¹ is, -NH binding group to R ¹⁴ as left -, - O -, - CONH -, - SO 2 NH -, - CH 2 NH -, - CH 2 NHCOCH 2 NH- or -X ¹² -Y ² -X ¹³ - represents, X ¹² is likewise -NH binding group to R ¹⁴ as left -, - O -, - CONH -, - sO 2 NH -, - CH 2 NH -, - NHCO- Or —NHSO ₂ —, X ¹³ represents —NH— or —O—, and Y ² represents an alkylene group which has 1 to 20 carbon atoms and may have a substituent. The alkenylene group which may have or the arylene group which may have a substituent is represented.
P represents a group represented by any one of the general formula (14), the general formula (15), and the general formula (16).
Q ² represents —O—R ¹⁵ , —NH—R ¹⁵ , a halogen group, —X ¹¹ —R ^14, or a group represented by any one of the general formula (14), the general formula (15), and the general formula (16). Represents.
R ¹⁵ represents a hydrogen atom, an alkyl group that may have a substituent, an alkenyl group that may have a substituent, or an aryl group that may have a substituent.
General formula (14)

一般式（１５）

General formula (15)

一般式（１６）

Formula (16)

X ¹⁴ is a direct bond, or, -SO ₂ binding group to the triazine ring as a left -, - CO -, - CH 2 NHCOCH 2 -, - CH 2 NHCONHCH 2 -, - CH 2 - or -X ¹⁵ - Y ² —X ¹⁶ — is represented. X ¹⁵ represents —NH— or —O—, and X ¹⁶ represents a direct bond or —SO ₂ —, —CO—, —CH ₂ NHCOCH ₂ —, —CH with the binding group to the triazine ring as the left end. ₂ represents NHCONHCH ₂ — or —CH ₂ —.
v ² represents an integer of 1 to 10.
R ¹⁶ and R ¹⁷ are each independently a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkenyl group, an optionally substituted aryl group or a heterocyclic residue, R ¹⁶ And R ¹⁷ may combine to form a ring.
R ¹⁸ , R ¹⁹ , R ²⁰ and R ²¹ each independently represents a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkenyl group or an optionally substituted aryl group.
R ²² represents an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted aryl group.

o represents an integer of 1 to 4.
R ¹⁴ represents a heterocyclic residue which may have a substituent, an aromatic ring residue which may have a substituent, or a group represented by the following general formula (17).
Formula (17)

T represents -X ¹⁸ -R ²³ or W, U represents -X ¹⁹ -R ²⁴ or W ^2.
W and W ² each independently represent —O—R ¹⁵ , —NH—R ¹⁵ , a halogen group or a group represented by any one of the general formula (14), the general formula (15), and the general formula (16). Represent.
X ¹⁷ represents —NH— or —O—, and X ¹⁸ and X ¹⁹ each independently represent —NH—, —O—, —CONH—, —SO ₂ NH with the binding group to the triazine ring as the left end. -, - CH ₂ NH- or an -CH ₂ NHCOCH ₂ NH-.
R ²⁴ and R ²⁵ each independently represents a heterocyclic residue which may have a substituent or an aromatic ring residue which may have a substituent.

Examples of the heterocyclic residue and the aromatic ring residue in R ^{14 in the} general formula (13) and R ²⁴ and R ²⁵ in the general formula (17) include, for example, thiophene, furan, pyridine, pyrazine, triazine, pyrazole, pyrrole, Examples include imidazole, isoindoline, isoindolinone, benzimidazolone, benzthiazole, benztriazole, indole, quinoline, carbazole, acridine, benzene, naphthalene, anthracene, fluorene, phenanthrene, anthraquinone, acridone and the like. These heterocyclic residues and aromatic ring residues are alkyl groups (methyl group, ethyl group, butyl group, etc.), amino groups, alkylamino groups (dimethylamino group, diethylamino group, dibutylamino group, etc.), nitro groups. Hydroxyl group, alkoxyl group (methoxy group, ethoxy group, butoxy group, etc.), halogen (chlorine, bromine, fluorine, etc.), phenyl group (alkyl group, amino group, alkylamino group, nitro group, hydroxyl group, alkoxy group, halogen, etc.) And a substituent such as a phenylamino group (which may be substituted with an alkyl group, amino group, alkylamino group, nitro group, hydroxyl group, alkoxy group, halogen, etc.) May be.

R ¹⁶ and R ¹⁷ are each independently a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkenyl group, an optionally substituted aryl group or a heterocyclic residue, R ¹⁶ And R ¹⁷ may combine to form a ring. In particular, a hydrogen atom is preferable because it is considered that the effect of suppressing metal deposition in the battery is high.
Y ³ in the general formula (13) and the general formula (17) represents an alkylene group, an alkenylene group or an arylene group which may have a substituent having 20 or less carbon atoms, and preferably has a substituent. Examples thereof include a phenylene group, a biphenylene group, a naphthylene group, or an alkylene group which may have a side chain having 10 or less carbon atoms.

Next, an organic dye derivative having a basic functional group represented by the general formula (106) will be described.
General formula (18)

Ｚ²は、下記一般式（１９）、一般式（２０）または一般式（２１）で示される基である。ｍは、１〜４の整数を表す。
一般式（１９）

一般式（２０）

Z ² is a group represented by the following general formula (19), general formula (20), or general formula (21). m represents an integer of 1 to 4.
General formula (19)

General formula (20)

一般式（２１）

Formula (21)

X ²⁰ is a direct bond, or, -SO binding group to R ²⁶ as left _{2 -, - CO -, -} CH 2 NHCOCH 2 -, - CH 2 NHCONHCH 2 -, - CH 2 - or -X ²¹ - Y ⁴ —X ²² — is represented. X ²¹ represents —NH— or —O—, and X ²² represents a direct bond or —SO ₂ —, —CO—, —CH ₂ NHCOCH ₂ —, —CH with the bond group to Y ⁴ as the left end. ₂ represents NHCONHCH ₂ — or —CH ₂ —. Y ⁴ represents an alkylene group which may have a substituent, an alkenylene group which may have a substituent, or an arylene group which may have a substituent, which is composed of 1 to 20 carbon atoms.
v3 represents an integer of 1 to 10.

R ²⁷ and R ²⁸ are each independently a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkenyl group, an optionally substituted phenyl group or a heterocyclic residue, R ²⁷ And R ²⁸ may combine to form a ring. In particular, a hydrogen atom is preferable because it is considered that the effect of suppressing metal deposition in the battery is high.
R ²⁹ , R ³⁰ , R ³¹ and R ³² each independently represent a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkenyl group or an optionally substituted aryl group.
R ³³ represents an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted aryl group.

R ²⁶ represents an organic dye residue, a heterocyclic residue which may have a substituent, or an aromatic ring residue which may have a substituent.
Examples of the organic dye residue in R ²⁶ include diketopyrrolopyrrole dyes, azo dyes such as azo, disazo, polyazo, phthalocyanine dyes, diaminodianthraquinone, anthrapyrimidine, flavantrons, anthanthrone, indanthrone, Anthraquinone dyes such as pyranthrone, violanthrone, quinacridone dyes, dioxazine dyes, perinone dyes, perylene dyes, thioindigo dyes, isoindoline dyes, isoindolinone dyes, quinophthalone dyes, selenium dyes, Examples include residues of metal complex dyes. In particular, in order to enhance the effect of suppressing the short circuit of the battery due to metal, it is preferable to use an organic dye residue that is not a metal complex dye.

Examples of the heterocyclic residue and aromatic ring residue in R ²⁶ include thiophene, furan, pyridine, pyrazole, pyrrole, imidazole, isoindoline, isoindolinone, benzimidazolone, benzthiazole, benztriazole, and indole. , Quinoline, carbazole, acridine, benzene, naphthalene, anthracene, fluorene, phenanthrene, anthraquinone, acridone and the like. These heterocyclic residues and aromatic ring residues are alkyl groups (methyl group, ethyl group, butyl group, etc.), amino groups, alkylamino groups (dimethylamino group, diethylamino group, dibutylamino group, etc.), nitro groups. Hydroxyl group, alkoxyl group (methoxy group, ethoxy group, butoxy group, etc.), halogen (chlorine, bromine, fluorine, etc.), phenyl group (alkyl group, amino group, alkylamino group, nitro group, hydroxyl group, alkoxy group, halogen, etc.) And a substituent such as a phenylamino group (which may be substituted with an alkyl group, amino group, alkylamino group, nitro group, hydroxyl group, alkoxy group, halogen, etc.) May be.

Examples of the amine component used for forming the substituents represented by the general formulas (14) to (16) and the general formulas (19) to (21) include dimethylamine, diethylamine, methylethylamine, N, N -Ethylisopropylamine, N, N-ethylpropylamine, N, N-methylbutylamine, N, N-methylisobutylamine, N, N-butylethylamine, N, N-tert-butylethylamine, diisopropylamine, dipropylamine N, N-sec-butylpropylamine, dibutylamine, di-sec-butylamine, diisobutylamine, N, N-isobutyl-sec-butylamine, diamylamine, diisoamylamine, dihexylamine, dicyclohexylamine, di (2-ethyl) Hexyl) amine, diocti Amine, N, N-methyloctadecylamine, didecylamine, diallylamine, N, N-ethyl-1,2-dimethylpropylamine, N, N-methylhexylamine, dioleylamine, distearylamine, N, N-dimethylaminomethyl Amine, N, N-dimethylaminoethylamine, N, N-dimethylaminoamylamine, N, N-dimethylaminobutylamine, N, N-diethylaminoethylamine, N, N-diethylaminopropylamine, N, N-diethylaminohexylamine, N, N-diethylaminobutylamine, N, N-diethylaminopentylamine, N
, N-dipropylaminobutylamine, N, N-dibutylaminopropylamine, N, N-dibutylaminoethylamine, N, N-dibutylaminobutylamine, N, N-diisobutylaminopentylamine, N, N-methyl-laurylamino Propylamine, N, N-ethyl-hexylaminoethylamine, N, N-distearylaminoethylamine, N, N-dioleylaminoethylamine, N, N-distearylaminobutylamine, piperidine, 2-pipecholine, 3-pipecholine, 4-Pipecoline, 2,4-Lupetidine, 2,6-Lupetidine, 3,5-Lupetidine, 3-Piperidinmethanol, Pipecolic acid, Isonipecotic acid, Methyl isonicopetinate, Ethyl isonicopetic acid, 2-Piperidinethanol, Pyrrolidine, 3- Hi Roxypyrrolidine, N-aminoethylpiperidine, N-aminoethyl-4-pipecholine, N-aminoethylmorpholine, N-aminopropylpiperidine, N-aminopropyl-2-pipecholine, N-aminopropyl-4-pipecholine, N- Examples include aminopropylmorpholine, N-methylpiperazine, N-butylpiperazine, N-methylhomopiperazine, 1-cyclopentylpiperazine, 1-amino-4-methylpiperazine, 1-cyclopentylpiperazine and the like.

  The method for synthesizing the organic dye derivative having a basic functional group or the triazine derivative having a basic functional group according to the present invention is not particularly limited, but is described in JP-A No. 54-62227 and JP-A No. 56-. No. 118462, JP-A 56-166266, JP-A 60-88185, JP-A 63-305173, JP-A 3-2676, JP-A 11-199796, etc. It can be synthesized by the method.

For example, the organic dye derivative having a basic functional group of the present invention is represented by the formula (22) to the formula (25) in an organic dye, a heterocyclic compound (for example, acridone) or an aromatic ring compound (for example, anthraquinone). After introducing the substituent, these substituents and amine components (eg, N, N-dimethylaminopropylamine, N-methylpiperazine, diethylamine or 4- [4-hydroxy-6- [3- (dibutylamino) propylamino] ] -1,3,5-triazin-2-ylamino] aniline and the like) can be synthesized.
Formula (22) -SO ₂ Cl
Formula (23) -COCl
Equation (24) -CH ₂ NHCOCH ₂ Cl
Equation (25) -CH ₂ Cl
In addition, for example, when the substituent represented by the formula (22) is introduced, an organic dye, a heterocyclic compound (for example, acridone) or an aromatic ring compound (for example, anthraquinone) is dissolved in chlorosulfonic acid, A chlorinating agent such as thionyl chloride is reacted, but depending on conditions such as reaction temperature and reaction time, a formula to be introduced into an organic dye, a heterocyclic compound (eg, acridone) or an aromatic ring compound (eg, anthraquinone) The number of substituents represented by (22) can be controlled.

  In addition, when the substituent represented by the formula (23) is introduced, first, an organic dye having a carboxyl group, a heterocyclic compound (for example, acridone) or an aromatic ring compound (for example, anthraquinone) is synthesized by a known method. Then, a method of reacting a chlorinating agent such as thionyl chloride in an aromatic solvent such as benzene is exemplified.

  During the reaction of the substituent represented by formula (22) to formula (25) and the amine component, a part of the substituent represented by formula (22) to formula (25) is hydrolyzed, and chlorine is substituted with a hydroxyl group. There are things to do. In that case, the substituent represented by the formula (22) is a sulfonic acid group, and the substituent represented by the formula (23) is a carboxylic acid group. Or a salt with the above amine.

When the organic dye is an azo dye, a substituent represented by formula (19) to formula (21) or the following general formula (26) is introduced in advance into the diazo component or coupling component, and then coupled. An azo organic dye derivative can also be produced by carrying out the reaction.
General formula (26)

X ²³ is, -NH binding group to the azo dye as a left -, - O -, - CONH -, - SO 2 NH -, - CH 2 NH -, - CH 2 NHCOCH 2 NH- or -X ²⁴ - Y ⁵ -X ²⁵ - represents, X ²⁴ is, -NH binding group to the azo dye as a left -, - O -, - CONH -, - SO 2 NH -, - CH 2 NH -, - NHCO- Or —NHSO ₂ —, X ²⁵ independently represents —NH— or —O—, and Y ⁵ is an alkylene group having 1 to 20 carbon atoms which may have a substituent. Represents an alkenylene group which may have an arylene group or an arylene group which may have a substituent.
P ² represents a substituent represented by any one of the general formulas (14), (15) and the general formula (16).
Q ³ represents —O—R ³⁴ , —NH—R ³⁴ , a halogen group, —X ²² —R ^33, or a substitution represented by any one of the general formula (14), (15), or the general formula (16). Represents a group.
R ³⁴ represents a hydrogen atom, an alkyl group that may have a substituent, an alkenyl group that may have a substituent, or an aryl group that may have a substituent.

  The triazine derivative having a basic functional group of the present invention is represented by, for example, cyanuric chloride as a starting material, and at least one chlorine of cyanuric chloride represented by formula (19) to formula (21) or general formula (26). It is obtained by reacting an amine component (for example, N, N-dimethylaminopropylamine or N-methylpiperazine etc.) that forms a substituent, and then reacting the remaining chlorine of cyanuric chloride with various amines or alcohols. It is done.

  The pigment derivative used in the present invention is preferably an organic dye derivative having an acidic or basic functional group, or a triazine derivative having an acidic or basic functional group, and has an acidic or basic functional group. A triazine derivative is more preferred, a triazine derivative having an acidic functional group is further preferred, and a triazine derivative having no acidic functional group and having an acidic functional group is particularly preferred.

You may use the said pigment derivative, mixing 1 type (s) or 2 or more types in arbitrary ratios.
In the present invention, it is considered that the pigment derivative mainly functions as a dispersant and also plays a role for creating an electrode film state suitable for improving battery performance.

<Solvent (E)>
Examples of the solvent (E) that may be used in the battery composition of the present invention (sometimes referred to as a solvent or a liquid medium in the present specification) include alcohols, glycols, cellosolves, and amino alcohols. Amines, ketones, carboxylic acid amides, phosphoric acid amides, sulfoxides, carboxylic acid esters, phosphoric acid esters, ethers, and nitriles.

Among these, it is preferable to use a polar solvent having a relative dielectric constant of 15 or more. The relative dielectric constant is one of the indices indicating the strength of the polarity of the solvent, and is described in Asahara et al., “Solvent Handbook” (Kodansha Scientific Co., Ltd., 1990).
For example, methyl alcohol (dielectric constant: 33.1), ethyl alcohol (23.8), 2-propanol (18.3), 1-butanol (17.1), 1,2-ethanediol (38.66) ), 1,2-propanediol (32.0), 1,3-propanediol (35.0), 1,4-butanediol (31.1), diethylene glycol (31.69), 2-methoxyethanol ( 16.93), 2-ethoxyethanol (29.6), 2-aminoethanol (37.7), acetone (20.7), methyl ethyl ketone (18.51), formamide (111.0), N-methylformamide (182.4), N, N-dimethylformamide (36.71), N-methylacetamide (191.3), N, N-dimethylacetamide (3 .78), N-methylpropionamide (172.2), N-methyl-2-pyrrolidone (32.0), hexamethylphosphoric triamide (29.6), dimethyl sulfoxide (48.9), sulfolane (43.3) ), Acetonitrile (37.5), propionitrile (29.7) and the like, but are not limited thereto.

  In particular, the use of a polar solvent having a relative dielectric constant of 15 or more and 200 or less, preferably 15 or more and 100 or less, more preferably 20 or more and 100 or less is excellent in dispersibility of the active material and the conductive assistant. It is preferable. The solvent is selected in view of reactivity with the active material, solubility in the binder resin, and the like. It is preferable to select a solvent having high dispersibility, low reactivity with the active material, and high solubility of the binder resin. Furthermore, from the viewpoint of reducing environmental burdens and economic advantages, when recovering and reusing the solvent discharged in the electrode manufacturing process, it is preferable to use a single solvent instead of a mixed solvent.

  As the solvent satisfying the relative permittivity, the reactivity with the active material, and the solubility of the binder resin and having versatility in a single use, an amide solvent is preferable, and in particular, N, N-dimethylformamide, It is preferable to use an amide aprotic non-aqueous solvent such as N, N-diethylformamide, N, N-dimethylacetamide, N, N-diethylacetamide, N-methyl-2-pyrrolidone, hexamethylphosphoric triamide. In particular, in the use mode of the present invention, N-methyl-2-pyrrolidone is preferable.

<Active material (G)>
When the composition of the present invention is used for a positive electrode mixture or a negative electrode mixture, in addition to the polymer dispersant (A), the carbon material (B), the derivative (D), and the solvent (E), an active material (G ) At least a positive electrode active material or a negative electrode active material.

The positive electrode active material for the lithium ion secondary battery is not particularly limited, but metal oxides capable of doping or intercalating lithium ions, metal compounds such as metal sulfides, and conductive polymers are used. be able to.
Examples thereof include transition metal oxides such as Fe, Co, Ni, and Mn, composite oxides with lithium, and inorganic compounds such as transition metal sulfides. Specifically, transition metal oxide powders such as MnO, V ₂ O ₅ , V ₆ O ₁₃ , TiO ₂ , layered structure lithium nickelate, lithium cobaltate, lithium manganate, spinel structure lithium manganate, etc. Examples thereof include composite oxide powders of lithium and transition metals, lithium iron phosphate materials that are phosphate compounds having an olivine structure, and transition metal sulfide powders such as TiS ₂ and FeS. In addition, conductive polymers such as polyaniline, polyacetylene, polypyrrole, and polythiophene can also be used. Moreover, you may mix and use said inorganic compound and organic compound.

The negative electrode active material for the lithium ion secondary battery is not particularly limited as long as it can be doped or intercalated with lithium ions. For example, metal Li, alloys thereof such as tin alloys, silicon alloys, lead alloys, Li _x Fe ₂ O ₃ , Li _x Fe ₃ O ₄ , Li _x WO ₂ , lithium titanate, lithium vanadate, silicon Metal oxides such as lithium oxide, conductive polymers such as polyacetylene and poly-p-phenylene, amorphous carbonaceous materials such as soft carbon and hard carbon, artificial graphite such as highly graphitized carbon materials, or natural Examples thereof include carbonaceous powders such as graphite, carbon black, mesophase carbon black, resin-fired carbon materials, air-growth carbon fibers, and carbon fibers. These negative electrode active materials can be used alone or in combination.

  These active materials (G) preferably have an average particle size in the range of 0.05 to 100 μm, and more preferably in the range of 0.1 to 50 μm. The average particle diameter of the active material (G) in the present specification is an average value of particle diameters of the active material (G) measured with an electron microscope.

<Binder (F)>
The composition of the present invention preferably further contains a binder. As binders to be used, ethylene, propylene, vinyl chloride, vinyl acetate, vinyl alcohol, maleic acid, acrylic acid, acrylic ester, methacrylic acid, methacrylic ester, acrylonitrile, styrene, vinyl butyral, vinyl acetal, vinyl pyrrolidone, etc. Polymer or copolymer containing as a structural unit: polyurethane resin, polyester resin, phenol resin, epoxy resin, phenoxy resin, urea resin, melamine resin, alkyd resin, acrylic resin, formaldehyde resin, silicone resin, fluorine resin; carboxymethylcellulose Such cellulose resins; rubbers such as styrene-butadiene rubber and fluororubber; and conductive resins such as polyaniline and polyacetylene. Moreover, the modified body and mixture of these resin, and a copolymer may be sufficient. In particular, it is preferable to use a polymer compound containing a fluorine atom in the molecule, for example, polyvinylidene fluoride, polyvinyl fluoride, tetrafluoroethylene, etc. from the viewpoint of resistance. In particular, in the use mode of the present invention, polyvinylidene fluoride is preferred.

  Moreover, as for the mass mean molecular weight of these resins as a binder, 10,000-1,000,000 are preferable. When the molecular weight is small, the resistance of the binder may decrease. When the molecular weight is increased, the resistance of the binder is improved, but the viscosity of the binder itself is increased and the workability is lowered.

  The composition of the present invention can be used for a positive electrode mixture or a negative electrode mixture. When used for the positive electrode mixture or the negative electrode mixture, an active material (G) (positive electrode active material) is added to the composition containing the polymer dispersant (A), the carbon material (B), and the solvent (E). Or a negative electrode active material), more preferably a positive / negative electrode mixture slurry containing a binder (F). Further, the composition may contain a derivative (D).

The proportion of the active material (G) in the total solid content in the electrode mixture slurry is preferably 80% by mass or more and 99% by mass or less. Moreover, 0.1 mass% or more and 10 mass% or less of the carbon material (B) ratio as a conductive support agent which occupy for the total solid in an electrode compound-material slurry are preferable. And the ratio of the binder (F) component in the total solid content in the electrode mixture slurry is preferably 0.5% by mass or more and 10% by mass or less.
Moreover, in this invention, the ratio of the polymer dispersing agent (A) which occupies in a compound material slurry shall be 0.01-7.5 mass% with respect to the mass of the carbon material (B) as a conductive support agent. Is preferred. More preferably, it is 0.1-5.0 mass% with respect to the mass of the carbon material (B) as a conductive support agent, More preferably, it is 1.0 with respect to the mass of the carbon material (B) as a conductive support agent. It is -5.0 mass%. When adding a derivative (D), the ratio of 1 mass% or more and 80 mass% or less is preferable with respect to the mass of a polymer dispersing agent (A), and 10 mass% or more and 60 mass% or less are more preferable.

  In addition, the appropriate viscosity of the electrode mixture slurry depends on the method of applying the electrode mixture slurry, but generally it is preferably 100 mPa · s or more and 30,000 mPa · s or less.

<Composition for forming secondary battery electrode>
Next, the manufacturing method of the composition for secondary battery electrode formation (it may only be called a "composition") is demonstrated. In the composition of the present invention, for example, in the presence of the polymer dispersant (A), the carbon material (B) as a conductive additive is dispersed in the solvent (E), and a derivative is added to the dispersion as necessary. (D), an active material (G) (a positive electrode active material or a negative electrode active material), and / or a binder (F) can be mixed and manufactured. The order of addition of each component is not limited to this. Moreover, you may add a solvent further as needed. In this specification, unless otherwise specified, the “dispersion” is composed of a polymer dispersant (A), a carbon material (B) as a conductive auxiliary agent, and a solvent (E), and a derivative (D). The composition for secondary battery electrode formation which can be included shall be pointed out. The “mixed material slurry” refers to a composition for forming a secondary battery electrode, wherein the “dispersion” further contains an active material (G) (positive electrode active material or negative electrode active material) and a binder (F). Shall point to.

  In the production method described above, the polymer dispersant (A), and further, if the derivative (D) is included, the derivative (D) is completely or partially dissolved in the solvent (E), and the solution is used as a conductive auxiliary agent. By adding and mixing the carbon material (B), the polymer dispersant (A), and further, when the derivative (D) is included, the derivative (D) is allowed to act (for example, adsorb) on the carbon material (B). , Dispersed in a solvent. The concentration of the carbon material (B) in the dispersion at this time depends on the characteristic values unique to the carbon material such as the specific surface area and surface functional group amount of the carbon material (B) to be used, but the production efficiency and dispersion efficiency From the viewpoint of the efficiency and workability of the contamination removal step described later, the content is preferably 1% by mass or more and 50% by mass or less, and more preferably 5% by mass or more and 35% by mass or less. In particular, when a step for removing contamination is added, the viscosity of the dispersion is preferably 5 mPa · s or more and 10,000 mPa · s or less, more preferably 5,000 mPa · s or less, and still more preferably 3,000 mPa · s or less. And

The dispersed particle diameter of the carbon material (B) as a conductive additive in the composition for forming a secondary battery electrode is 0.03 μm or more and 2 μm or less, preferably 0.05 μm or more and 1 μm or less, more preferably 0. Desirably, the thickness is from 0.05 μm to 0.5 μm.
The dispersed particle diameter of the carbon material (B) referred to in the present specification is a particle diameter (D50) that is 50% when the volume ratio of the particles is integrated from the small particle diameter in the volume particle size distribution. It is a value measured by a particle size distribution meter of a dynamic light scattering method (in the examples of this specification, “Microtrack UPA” manufactured by Nikkiso Co., Ltd.).

  In addition, as a device for dispersing the polymer dispersant (A) and the derivative (D) in the solvent while acting (for example, adsorbing) the derivative (D) on the carbon material (B) when the polymer dispersant (A) is further included, A disperser used for pigment dispersion or the like can be used. For example, mixers such as dispersers, homomixers, planetary mixers, homogenizers ("Clearmix" manufactured by M Technique, PRIMIX "Fillmix", etc.), paint conditioners (manufactured by Red Devil), ball mills, sand mills ( Media type dispersers such as “Dynomill” manufactured by Shinmaru Enterprises, Inc.), Attritor, Pearl Mill (“DCP Mill” manufactured by Eirich), Coball Mill, etc., Wet Jet Mill (“Genus PY” manufactured by Genus, Sugino Machine Co., Ltd.) Media-less dispersers such as “Starburst” manufactured by Nanomizer, “Nanomizer” manufactured by Nanomizer, etc., “Claire SS-5” manufactured by M Technique, and “MICROS” manufactured by Nara Machinery Co., other roll mills, etc. It is not limited to. Moreover, as the disperser, it is preferable to use a disperser that has been subjected to a metal contamination prevention treatment from the disperser.

  For example, when using a media-type disperser, the agitator and vessel are dispersed using a ceramic or resin disperser, or the surface of the metal agitator and vessel is treated with tungsten carbide spraying or resin coating. It is preferable to use a machine. And as a media, it is preferable to use ceramic beads, such as glass beads, zirconia beads, and alumina beads, and among them, the use of zirconia beads is preferable. Moreover, also when using a roll mill, it is preferable to use a ceramic roll. Only one type of dispersion device may be used, or a plurality of types of devices may be used in combination. Further, in the case of a positive or negative electrode active material in which particles are easily broken or crushed by a strong impact, a medialess disperser such as a roll mill or a homogenizer is preferable to a media type disperser.

  In addition, it is preferable to include a step of removing contaminants such as metal foreign matters during dispersion. Carbon black, graphite, and carbon materials such as carbon fiber often contain metallic foreign matters derived from their manufacturing processes (as line contamination and catalysts). It is very important to prevent short circuit. In the present invention, because of the effect of the polymer dispersant (A), the aggregation of the carbon materials (B) is well loosened, and the viscosity of the dispersion is lowered, so even when the concentration of the carbon material in the dispersion is high. , Metal foreign matter can be efficiently removed. Examples of methods for removing metallic foreign substances include iron removal with a magnet, filtration, and centrifugation.

  As a method for adding the binder (F), the carbon dispersant (B) as a conductive additive is dispersed in a solvent in the presence of the derivative (D) when the polymer dispersant (A) is further included. A method of adding and dissolving a solid binder component while stirring the resulting dispersion is mentioned. Moreover, what melt | dissolved the binder in the solvent is produced beforehand and the method of mixing with the said dispersion is mentioned. Further, after the binder (F) is added to the dispersion, the dispersion treatment may be performed again by the dispersion apparatus. Further, when the polymer dispersant (A) and the derivative (D) are further included, when the carbon material (B) as the conductive assistant is dispersed in the solvent (E) in the presence of the derivative (D), a binder is used. A part or all of (F) can be added simultaneously to carry out the dispersion treatment.

  As a method for adding the active material (G) (positive electrode active material or negative electrode active material), in the presence of the derivative (D) when the polymer dispersant (A) and the derivative (D) are further included, The positive electrode active material or the negative electrode active material may be added and dispersed while stirring the dispersion obtained by dispersing the carbon material (B) in the solvent (E). In addition, when the polymer dispersant (A) and the derivative (D) are further included, when the carbon material as the conductive additive is dispersed in the solvent in the presence of the derivative (D), the positive electrode active material or the negative electrode active material A part or all of the above can be added at the same time to carry out the dispersion treatment. Further, when the polymer dispersant (A) and the derivative (D) are further included, a dispersion obtained by dispersing the carbon material (B) as a conductive additive in the solvent (E) in the presence of the derivative (D). There is a method of adding a positive electrode active material or a negative electrode active material and dispersing the binder component in a solid or solution while stirring. Further, when the polymer dispersant (A), the carbon material (B), the solvent (E), the active material (G), the binder (F) and the derivative (D) are included, the derivative (D) is mixed, and at the same time Distributed processing is also possible. As an apparatus for mixing and dispersing, the above-described dispersers used for ordinary pigment dispersion and the like can be used.

The size of the active material (G) to be used is preferably in the range of 0.05 to 100 μm, more preferably in the range of 0.1 to 50 μm in terms of average particle size. Here, the average particle diameter of the active material is an average value of the major axis of each primary particle in an observation image obtained by a scanning electron microscope (SEM; Scanning Electron Microscope). However, in order to increase the reaction area of the active material, an active material may be an aggregate (secondary particle) that is obtained by granulating fine primary particles after the synthesis process or after synthesis. Measures the major axis of the secondary particles and sets the average particle size of the active material.
The ratio of the average particle size of the active material (G) to the dispersed particle size (D50) of the carbon material (B) described above (average particle size of the active material (G) / dispersed particle size of the carbon material (B) (D50 )), It is preferably 2 or more and 100 or less. More preferably, it is 9 or more and 70 or less.

As described above, the composition of the present invention can be usually produced, distributed and used as a dispersion (liquid) containing a solvent, a paste or the like. This is because even if the conductive auxiliary agent or active material and the dispersing agent are mixed in a dry powder state, the dispersing agent cannot be uniformly applied to the conductive auxiliary agent or the active material. This is because, by dispersing the conductive additive and the active material in the solvent in the presence of, the dispersant can be made to act uniformly on the conductive additive and the active material. Further, as described below, when the electrode mixture layer is formed on the current collector, it is preferable to apply the liquid dispersion as uniformly as possible and dry it.
However, for example, a dispersion produced by a liquid phase method is used to remove the solvent once to make a dry powder for reasons of transportation cost, etc., and then re-disperse the dry powder with an appropriate solvent. You may use for formation of. Therefore, the composition of the present invention is not limited to a liquid dispersion, and may be a composition in a dry powder state.

  Of the composition for forming a secondary battery electrode of the present invention, the mixture slurry is coated on a current collector and dried to form a mixture layer, whereby a secondary battery electrode can be obtained.

(Current collector)
The material and shape of the current collector used for the electrode are not particularly limited, and those suitable for various secondary batteries can be appropriately selected. For example, examples of the material for the current collector include metals and alloys such as aluminum, copper, nickel, titanium, and stainless steel. In general, a flat foil is used as the shape, but a roughened surface, a perforated foil, or a mesh current collector can also be used.

  There is no restriction | limiting in particular as a method of apply | coating a mixture slurry and the composition for base layer formation on a collector, A well-known method can be used. Specific examples include die coating method, dip coating method, roll coating method, doctor coating method, knife coating method, spray coating method, gravure coating method, screen printing method or electrostatic coating method, and the like. Examples of methods that can be used include standing drying, blower dryers, hot air dryers, infrared heaters, and far-infrared heaters, but are not particularly limited thereto.

  Moreover, you may perform the rolling process by a lithographic press, a calender roll, etc. after application | coating. The thickness of the electrode mixture layer is generally 1 μm or more and 500 μm or less, preferably 10 μm or more and 300 μm or less.

  A secondary battery can be obtained by using the above electrode for at least one of a positive electrode and a negative electrode. Secondary batteries include lithium ion secondary batteries, sodium ion secondary batteries, magnesium secondary batteries, alkaline secondary batteries, lead storage batteries, nickel metal hydride batteries, nickel cadmium batteries, sodium sulfur secondary batteries, lithium air batteries. Secondary batteries, fuel cells, and the like, preferably lithium ion secondary batteries, nickel metal hydride batteries, and fuel cells, more preferably lithium ion secondary batteries, nickel metal hydride batteries, and particularly preferably lithium ion secondary batteries. Next battery. In each secondary battery, conventionally known electrolytes, separators, and the like can be appropriately used.

(Electrolyte)
A case of a lithium ion secondary battery will be described as an example. As the electrolytic solution, an electrolyte containing lithium dissolved in a non-aqueous solvent is used. As electrolytes, LiBF ₄ , LiClO ₄ , LiPF ₆ , LiAsF ₆ , LiSbF ₆ , LiCF ₃ SO ₃ , Li (CF ₃ SO ₂ ) ₂ N, LiC ₄ F ₉ SO ₃ , Li (CF ₃ SO ₂ ) ₃ C , LiI, LiBr, LiCl, LiAlCl, LiHF ₂ , LiSCN, or LiBPh _4, but are not limited thereto.

  The non-aqueous solvent is not particularly limited. For example, carbonates such as ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, ethyl methyl carbonate, and diethyl carbonate; γ-butyrolactone, γ-valerolactone, and γ Lactones such as octanoic lactone; tetrahydrofuran, 2-methyltetrahydrofuran, 1,3-dioxolane, 4-methyl-1,3-dioxolane, 1,2-methoxyethane, 1,2-ethoxyethane, and 1, Glymes such as 2-dibutoxyethane; esters such as methyl formate, methyl acetate, and methyl propionate; sulfoxides such as dimethyl sulfoxide and sulfolane; and nitriles such as acetonitrile. And the like. These solvents may be used alone or in combination of two or more.

  Furthermore, the electrolytic solution can be used in the form of a polymer electrolyte that is held in a polymer matrix and is in the form of a gel. Examples of the polymer matrix include, but are not limited to, an acrylate resin having a polyalkylene oxide segment, a polyphosphazene resin having a polyalkylene oxide segment, and a polysiloxane having a polyalkylene oxide segment.

(separator)
Examples of the separator include, but are not limited to, a polyethylene nonwoven fabric, a polypropylene nonwoven fabric, a polyamide nonwoven fabric and those obtained by subjecting them to a hydrophilic treatment.

(Battery structure / configuration)
The structure of the lithium ion secondary battery using the composition of the present invention is not particularly limited, but is usually composed of a positive electrode and a negative electrode, and a separator provided as necessary, a paper type, a cylindrical type, a button type, It can be made into various shapes according to the purpose of use, such as a laminated type.

  EXAMPLES Hereinafter, although this invention is demonstrated in more detail based on an Example, this invention is not limited to these. In Examples, “part” represents “part by mass”, and “%” represents “% by mass”. Further, N-methyl-2-pyrrolidone used as the solvent (E) may be abbreviated as “NMP”.

<Synthesis of copolymer>
(Synthesis Example 1)
In a reaction vessel equipped with a gas introduction tube, a thermometer, a condenser, and a stirrer, 200.0 parts of NMP was charged and replaced with nitrogen gas. The inside of the reaction vessel was heated to 110 ° C., and a mixture of 100.0 parts of styrene, 100.0 parts of 4-hydroxybutyl acrylate, and 12.0 parts of V-601 (manufactured by Wako Pure Chemical Industries) as a polymerization initiator was added. The polymerization reaction was carried out by adding dropwise over time. After completion of the dropwise addition, the mixture was further reacted at 110 ° C. for 3 hours, and then 0.6 part of V-601 (manufactured by Wako Pure Chemical Industries, Ltd.) was added, and the reaction was further continued at 110 ° C. for 1 hour. Cooled down. The obtained solution was diluted with NMP to obtain a copolymer (1) solution having a nonvolatile content of 20%.

(Synthesis Examples 2 to 5)
Except having changed into the material and composition shown in Table 1, it synthesize | combined by the method similar to the synthesis example 1, and obtained the copolymer solution of the synthesis examples 2-5, respectively.

<Evaluation of copolymer>
(Evaluation of degree of polymerization)
Number average molecular weight (Mn) of copolymer:
Using standard polystyrene having a known peak molecular weight, gel permeation chromatography (GPC) calibrated with the standard (“HLC-8020” manufactured by Tosoh Corporation) was used to measure the number average molecular weight (Mn) of the copolymer. (Solvent: tetrahydrofuran, temperature: 40 ° C).

Degree of polymerization of copolymer:
The value obtained by dividing the number average molecular weight (Mn) of the copolymer by the average molecular weight of the monomer used for the production of the copolymer was defined as the degree of polymerization.
When the monomer 1 having the molecular weight M1 and the monomer 2 having the molecular weight M2 are polymerized at a mass ratio of W1 and W2, respectively, the average molecular weight of the copolymer monomer is (W1-W2). / (W1 / M1 + W2 / M2).

Ｓｔ：スチレン （分子量１０４．２）
４ＨＢＡ：４−ヒドロキシブチルアクリレート （分子量１４４．２）
ＬＭＡ：ラウリルメタクリレート （分子量２５４．４）
ＨＥＡ：ヒドロキシエチルアクリレート （分子量１１６．１）
ＡＡ：アクリル酸 （分子量７２．１）
ＨＰＡ：ヒドロキシプロピルアクリレート （分子量１３０．１）
ＢＡ：ブチルアクリレート （分子量１２８．２）
ＨＥＭＡ：ヒドロキシエチルメタクリレート （分子量１３０．１）
ＢｚＭＡ：ベンジルメタクリレート （分子量１７６．２）

St: Styrene (Molecular weight 104.2)
4HBA: 4-hydroxybutyl acrylate (molecular weight: 144.2)
LMA: lauryl methacrylate (molecular weight 254.4)
HEA: hydroxyethyl acrylate (molecular weight 116.1)
AA: acrylic acid (molecular weight 72.1)
HPA: hydroxypropyl acrylate (molecular weight 130.1)
BA: Butyl acrylate (molecular weight 128.2)
HEMA: hydroxyethyl methacrylate (molecular weight 130.1)
BzMA: benzyl methacrylate (molecular weight 176.2)

<Synthesis of Polymer Dispersant (A)>
(Synthesis of Polymer Dispersant (A-1) (Synthesis Example 6))
A reaction vessel equipped with a gas introduction tube, a thermometer, a condenser, and a stirrer was charged with 50.0 parts of the copolymer solution (1) (10.0 parts as the copolymer (1)) and replaced with nitrogen gas. . The inside of the reaction vessel was heated to 60 ° C., and 0.35 part of succinic anhydride was added. The inside of the reaction vessel was heated to 90 ° C., and 0.05 part of diazabicycloundecene (DBU, manufactured by Tokyo Chemical Industry) was added as a reaction reagent. After completion of the addition, the inside of the reaction vessel was heated to 110 ° C., and the reaction was continued for 5 hours. Thereafter, the acid anhydride value was measured to confirm that the reaction rate was 95% or more. Thereafter, N-methyl-2-pyrrolidone was added for dilution. V. = 20%. Then, it cooled and obtained the polymer dispersing agent solution (A'-1) containing a polymer dispersing agent (A-1).

(Synthesis of polymer dispersants (A-2) to (A-5) (Synthesis Examples 7 to 10))
Except having changed into the material and composition shown in Table 2, it synthesize | combined by the method similar to the synthesis example 6, and obtained the polymer dispersing agent solution of the synthesis examples 7-10, respectively.

The degree of polymerization of the polymer dispersants (A-1) to (A-5) is the degree of polymerization of the copolymers (1) to (5) as synthetic raw materials.

ＯＳＡ：リカシッドＯＳＡ（新日本理化）

OSA: Ricacid OSA (New Japan Rika)

(Synthesis of Polymer Dispersant (A-6) (Synthesis Example 11))
In a reaction vessel equipped with a gas introduction tube, a thermometer, a condenser, and a stirrer, 200.0 parts of N-methyl-2-pyrrolidone and 50.0 parts of PVA102 were charged and replaced with nitrogen gas. The inside of the reaction vessel was heated to 60 ° C., and 2.21 parts of phthalic anhydride was added. The inside of the reaction vessel was heated to 90 ° C., and 0.05 part of DBU (manufactured by Tokyo Chemical Industry) was added as a reaction reagent. After completion of the addition, the inside of the reaction vessel was heated to 110 ° C., and the reaction was continued for 5 hours. Thereafter, the acid anhydride value was measured to confirm that the reaction rate was 95% or more. Thereafter, N-methyl-2-pyrrolidone was added for dilution. V. = 20%. Then, it cooled and obtained the polymer dispersing agent solution (A'-6) containing a polymer dispersing agent (A-6).

(Synthesis of polymer dispersants (A-7) to (A-11) (Synthesis Examples 12 to 16))
Except having changed into the material and composition shown in Table 2, it synthesize | combined by the method similar to the synthesis example 11, and obtained the polymer dispersing agent solution of the synthesis examples 12-16, respectively.

  The polymerization degrees of the polymer dispersants (A-5) to (A-11) were the polymerization degrees of the synthetic raw materials (PVA102, PVA103, etc.).

・ＰＶＡ１０２：クラレポバールＰＶＡ１０２（クラレ製）：ケン化度：９８．０―９９．０％、重合度：２００。
・ＰＶＡ１０３：クラレポバールＰＶＡ１０３（クラレ製）：ケン化度：９８．０―９９．０％、重合度：３００。
・ＰＶＡ４０３：クラレポバールＰＶＡ４０３（クラレ製）：ケン化度：７８．５−８１．５％、重合度：３００。
・ＰＶＡ５０５：クラレポバールＰＶＡ５０５（クラレ製）：ケン化度：７２．５−７４．５％、重合度：５００。
・ＢＬ−Ｓ：エスレックＢＬ−Ｓ（積水化学工業社製）：ポリビニルブチラール樹脂、水酸基を含む構造単位：２２ｍｏｌ％、アセチル基を含む構造単位：４ｍｏｌ％、ブチラール環を含む構造単位；７４ｍｏｌ％、計算分子量：２３，０００。
・ＢＨ−Ｓ：エスレックＢＨ−Ｓ（積水化学工業社製）：ポリビニルブチラール樹脂、水酸基を含む構造単位：２２％、アセチル基を含む構造単位：５ｍｏｌ％、ブチラール環を含む構造単位；７３ｍｏｌ％、計算分子量：６６，０００。

PVA102: Kuraray Poval PVA102 (manufactured by Kuraray): degree of saponification: 98.0-99.0%, degree of polymerization: 200.
PVA103: Kuraray Poval PVA103 (manufactured by Kuraray): degree of saponification: 98.0-99.0%, degree of polymerization: 300.
PVA403: Kuraray Poval PVA403 (manufactured by Kuraray): degree of saponification: 78.5-81.5%, degree of polymerization: 300.
PVA505: Kuraray Poval PVA505 (manufactured by Kuraray): degree of saponification: 72.5-74.5%, degree of polymerization: 500.
BL-S: ESREC BL-S (manufactured by Sekisui Chemical Co., Ltd.): polyvinyl butyral resin, structural unit containing a hydroxyl group: 22 mol%, structural unit containing an acetyl group: 4 mol%, structural unit containing a butyral ring; 74 mol%, Calculated molecular weight: 23,000.
BH-S: ESREC BH-S (manufactured by Sekisui Chemical Co., Ltd.): polyvinyl butyral resin, structural unit containing hydroxyl group: 22%, structural unit containing acetyl group: 5 mol%, structural unit containing butyral ring; 73 mol%, Calculated molecular weight: 66,000.

<Manufacture of secondary battery electrode forming composition (dispersion)>
[Example 1]
A carbon material dispersion was prepared according to the composition shown in Table 4. First, while stirring 80.0 parts of N-methyl-2-pyrrolidone as a solvent with a mixer, a polymer dispersant solution (A′-1) containing the polymer dispersant (A-1) shown in Table 2 ( 4 parts of solid content (20%) was added and dissolved by stirring. Next, after adding 16 parts of Denka Black HS-100 (manufactured by Denki Kagaku Kogyo Co., Ltd.) as a conductive auxiliary agent and mixing with a mixer, the mixture is further dispersed with a sand mill, in one aspect of the composition for forming a secondary battery electrode. A dispersion 1 was obtained.

[Examples 2 to 11]
In accordance with the composition shown in Table 4, Denka Black HS-100 (manufactured by Denki Kagaku Kogyo Co., Ltd.) or Super-PLi (manufactured by TIMCAL) as a carbon material and a polymer dispersant solution (A′-1) as a dispersant. ) Were changed to polymer dispersant solutions (A′-2) to (A′-11) in the same manner as in Example 1 to obtain dispersions 2 to 11, respectively.

[Examples 12 to 15]
According to the composition shown in Table 4, 16 parts of Denka Black HS-100 (manufactured by Denki Kagaku Kogyo Co., Ltd.) as a carbon material, 3 parts of various polymer dispersant solutions shown in Table 2 as a dispersant, and Table 5 Dispersions 12 to 15 were prepared in the same manner as in Example 1, except that 0.2 parts of the derivatives (D-1) to (D-4) were added to 80.8 parts of N-methyl-2-pyrrolidone. Respectively.

[Example 16]
According to the composition shown in Table 4, while stirring 82.0 parts of N-methyl-2-pyrrolidone as a solvent with a mixer, 2.0 parts of a polymer dispersant solution (A′-11) as a dispersant was added and stirred. A dispersion 16 was obtained in the same manner as in Example 1 except for dissolution.

[Example 17]
According to the composition shown in Table 4, while stirring 68.0 parts of N-methyl-2-pyrrolidone as a solvent with a mixer, 16.0 parts of a polymer dispersant solution (A′-3) as a dispersant was added and stirred. A dispersion 17 was obtained in the same manner as in Example 1 except for dissolution.

[Comparative Examples 1-3]
According to the composition shown in Table 4, Denka Black HS-100 (manufactured by Denki Kagaku Kogyo Co., Ltd.) or Super-PLi (manufactured by TIMCAL) as a carbon material, and a copolymer (1 ) Solution, PVA103 solution with PVA103 dissolved in N-methyl-2-pyrrolidone to 20% solids, BL-S with BL-S solution with N-methyl-2-pyrrolidone dissolved in 20% solids Except having carried out, it carried out similarly to Example 1, and obtained the dispersions 18-20, respectively.

[Comparative Example 4]
According to the composition shown in Table 4, 16 parts of Denka Black HS-100 (manufactured by Denki Kagaku Kogyo Co., Ltd.) as the carbon material, 3 parts of the PVA103 solution shown in Table 2 as the dispersant, and the derivatives (D- Dispersion 21 was obtained in the same manner as in Example 1, except that 1) was added to 0.2 part and 80.8 parts of N-methyl-2-pyrrolidone.

<Evaluation of dispersion>
(Evaluation of dispersion stability)
The dispersion particle size was used as an index for evaluating the dispersibility of the dispersion. The results are shown in Table 4. Dispersion particle size is measured by using a dynamic light scattering particle size distribution meter ("MICROTRACK UPA" manufactured by Nikkiso Co., Ltd.). The particle diameter (D50) at 50% was determined. This particle size (D50) corresponds to the dispersed particle size of the carbon material (B).
A sample solution for measurement was prepared as follows. While stirring 100 g of N-methyl-2-pyrrolidone, 1 to 4 drops of the various dispersions obtained above were added to the liquid and stirred at 1,000 rpm for 5 minutes. The sample liquid for measurement was set in the above particle size distribution meter, and after confirming that the loading index (laser scattering intensity) was in the range of 0.8 to 1.2, the dispersed particle size was measured. When the loading index exceeded 1.2 in the above preparation method, the sample solution was appropriately diluted with N-methyl-2-pyrrolidone so as to be in the range of 0.8 to 1.2. The measurement time was 60 seconds / once, and the average value of the values obtained by three consecutive measurements was used.
Table 4 shows the results of evaluating the dispersibility of the dispersion. The smaller the value, the better the dispersibility and the more uniform and good dispersion. The dispersion particle size of the dispersion was measured twice immediately after the production of various dispersions and after the dispersion was stored at 50 ° C. for 15 days.
In Table 4, “storage stability (2) / (1)” means the ratio of “dispersion particle size of dispersion stored at 50 ° C. for 15 days / dispersion particle size of dispersion immediately after production”, The smaller the deviation from 1.00, the better the storage stability.

<Carbon material (B)>
A: Denka black HS-100 (manufactured by Denki Kagaku Kogyo): acetylene black, primary particle diameter 48 nm, specific surface area 48 m ² / g, hereinafter abbreviated as “HS-100”.
F: Super-P Li (manufactured by TIMCAL): furnace black. Primary particle diameter 40 nm, specific surface area 62 m ² / g.

Table 5 shows the derivatives used in Examples 12 to 15 and Comparative Example 4.

  Regarding the dispersibility of the carbon material dispersion of the present invention, as shown in Table 4, all of the dispersions have good dispersibility of the carbon material, and are dispersions in which the carbon material is uniformly dispersed. confirmed. In addition, it was confirmed that the carbon material dispersions in the examples were excellent in storage stability as compared with the comparative examples, in that the dispersion particle size immediately after production and the dispersion particle size after storage at 50 ° C. for 15 days were small. It was.

<Manufacture of secondary battery electrode forming composition (positive electrode mixture slurry)>
[Example 18]
Disperse 1 produced in Example 1 (13.8 parts) and 17.5 parts of an N-methyl-2-pyrrolidone solution of W # 1100 (solid content 12%) as a binder are sampled and mixed with a disper to homogenize. While this mixture was stirred with a disper, 68.6 parts of LiCoO ₂ (hereinafter abbreviated as LCO) having an average particle diameter of 6.7 μm was gradually added as a positive electrode active material, and then the solid content of the mixture slurry was 73%. Then, N-methyl-2-pyrrolidone was further added as a solvent and mixed with a disper for 30 minutes to produce a positive electrode mixture slurry.

[Examples 19 to 26, Examples 29 to 32, Comparative Examples 5 to 8]
A positive electrode mixture slurry was produced in the same manner as in Example 21 except that the materials shown in Table 6 were changed. As active materials, LCO, LiMn ₂ O ₄ (hereinafter abbreviated as LMO) having an average particle diameter of 12 μm, LiNi _(1/3) Mn _(1/3) Co _{(1/3) having} an average particle diameter of 15 μm Any of O ₂ (hereinafter abbreviated as NMC) was used.

[Example 27]
15.6 parts of the dispersion 10 produced in Example 10 and 31.3 parts of an N-methyl-2-pyrrolidone solution (solid content 8%) of W # 7200 as a binder (F) were collected and mixed uniformly with a disper. Turn into. While stirring this mixed solution with a disper, 45 parts of LiFePO ₄ (hereinafter abbreviated as LFP-01) having an average particle diameter of 1 μm having a carbon coat layer on the surface was gradually added as a positive electrode active material, and then a mixture slurry N-methyl-2-pyrrolidone was further added as a solvent so that the solid content of the mixture became 50%, and the mixture was mixed with a disper for 30 minutes to produce a positive electrode mixture slurry.

[Examples 28 and 33]
Except having changed into the material shown in Table 6, it carried out similarly to Example 27, and manufactured the positive mix slurry, respectively.

<Binder (F)>
KF polymer W # 1100 (manufactured by Kureha): polyvinylidene fluoride (PVDF), molecular weight: 280,000. Hereinafter, it may be abbreviated as “W # 1100”.
KF polymer W # 7200 (manufactured by Kureha): polyvinylidene fluoride (PVDF), molecular weight: 630,000. Hereinafter, it may be abbreviated as “W # 7200”.

<Manufacture of secondary battery electrode forming composition (negative electrode mixture slurry)>
[Example 35]
11.3 parts of Dispersion 4 produced in Example 4 and 28.8 parts of an N-methyl-2-pyrrolidone solution of W # 7200 (solid content 8%) as a binder (F) were mixed with a disper and homogenized. Thereafter, 55.8 parts of artificial graphite having an average particle diameter of 15 μm was gradually added as a negative electrode active material while stirring the liquid. Next, N-methyl-2-pyrrolidone as a solvent (E) is added and further mixed so that the solid content of the mixture slurry is 60%, and the negative electrode composite which is one embodiment of the composition for forming a secondary battery electrode is formed. A material slurry was produced.

[Comparative Example 9]
Except having changed into the material shown in Table 7, it carried out similarly to Example 35, and adjusted the negative mix slurry.

[Example 36]
17.8 parts of the dispersion 8 produced in Example 8 and 33.8 parts of an N-methyl-2-pyrrolidone solution of W # 7200 (8% solids) as a binder (F) were mixed with a disper to make uniform. Thereafter, 51.3 parts of Li ₄ Ti ₅ O ₁₂ (hereinafter sometimes abbreviated as LTO) having an average particle diameter of 5 μm was gradually added as the negative electrode active material while stirring the liquid. Next, N-methyl-2-pyrrolidone was added and mixed as a solvent (E) so that the solid content of the mixture slurry was 57%, thereby producing a negative electrode mixture slurry.

[Comparative Examples 10 and 11]
Except having changed into the material shown in Table 7, it carried out similarly to Example 36, and adjusted the negative mix slurry, respectively.

(Average particle size of active material)
The average particle diameter of the active material was calculated from an observation image obtained from a scanning electron microscope (SEM). Here, for LCO, LMO, LFP, artificial graphite, and LTO, the major axis of 100 primary particles was measured and calculated from the average value. For NMC, the major axis of 100 secondary particles was measured and calculated from the average value.

<Evaluation of composite slurry>
(Dispersibility evaluation)
The dispersibility of the positive electrode mixture slurry and the negative electrode mixture slurry was evaluated by evaluating the particle size using a grind gauge (according to JIS K5600-2-5). The smaller the numerical value, the better the dispersibility and the more uniform and good dispersion. The particle size of the composite slurry was measured immediately after the production of the various slurries and after the slurry was stored at 40 ° C. for 4 days. In the measurement, the particle size was measured immediately after slurry production and after defoaming with a planetary defoaming device. Moreover, about the mixture slurry preserve | saved for 4 days at 40 degreeC, after re-stirring with a disper, after carrying out defoaming with a planetary rotation type defoaming apparatus, the particle size was measured. The results are shown in Tables 8 and 9.

<Manufacture of secondary battery electrodes (positive electrode, negative electrode)>
The prepared positive electrode mixture slurry is applied onto a 20 μm thick aluminum foil serving as a current collector using a doctor blade so that the thickness of the electrode after drying the coating film is 100 μm. Preparation and this were dried with a 120 degreeC drying furnace, and the coating material was obtained. This was further subjected to a rolling process by a roll press to produce a positive electrode having a thickness of 85 μm.

  The prepared negative electrode mixture slurry is applied onto a 20 μm thick copper foil serving as a current collector using a doctor blade so that the thickness of the electrode after the coating film is dried is 80 μm. Preparation and this were dried with a 120 degreeC drying furnace, and the coating material was obtained. This was further subjected to a rolling process by a roll press to produce a negative electrode having a thickness of 70 μm.

<Manufacture of secondary batteries (coin-type batteries)>
The positive electrode or negative electrode obtained by the above method was punched into a diameter of 16 mm as a working electrode, and a metal lithium foil was used as a counter electrode. A porous separator made of polypropylene is laminated between the working electrode and the counter electrode, and the electrolyte solution (a mixed solvent in which ethylene carbonate and diethyl carbonate are mixed at a ratio of 1: 1 (volume ratio) is mixed with LiPF ₆ at a concentration of 1M. A coin-type battery was manufactured in such a way that the gap was filled with the dissolved non-aqueous electrolyte solution). The coin-type battery was manufactured in a glove box substituted with argon gas, and then the battery characteristics were evaluated as follows.

<Evaluation of secondary battery (positive electrode, negative electrode)>
About the positive electrode, the discharge capacity maintenance factor of 50 cycles and 200 cycles was measured. The results are shown in Table 8. About the negative electrode, the discharge capacity maintenance factor of 50 cycles and 100 cycles was measured. The results are shown in Table 9.

(Cycle characteristics (50 cycles))
Using the obtained coin-type battery, using the rechargeable device (Hokuto Denko Co. SM-8), were charged and discharged measurement, in the case of LiCoO _2, until the charge end voltage 4.3V at a charge rate 1.0C constant-Nagarejo After the voltage charge was continued and the battery was fully charged, constant current discharge was performed at a discharge rate of 1.0 C until a discharge end voltage of 2.8 V was reached.

Moreover, when the active material to be used is LiMn ₂ O ₄ and LiNi _1/3 Mn _1/3 Co _1/3 O ₂ , except that the charge end voltage is 4.3 V and the discharge end voltage is 3.0 V, The charge / discharge measurement was performed in the same manner as LiCoO ₂ .

Further, when the active material used was LiFePO ₄ , charge / discharge measurement was performed in the same manner as LiCoO ₂ except that the charge end voltage was 4.2 V and the discharge end voltage was 2.0 V.

  In the negative electrode evaluation, in the case of artificial graphite, the charge end voltage was 0.01 V and the discharge end voltage was 1.5 V, and in the case of lithium titanate, the discharge end voltage was 2.0 V and the charge end voltage was 1.0 V. The charge / discharge measurement was performed in the same manner as in the positive electrode evaluation.

These charge / discharge cycles are defined as one cycle, and 50 cycles of charge / discharge are repeated, so that “discharge capacity maintenance rate (50 cycles) = 50th cycle discharge capacity / first cycle discharge capacity”. The determination was made according to the following criteria.
A: “Discharge capacity maintenance ratio is 95% or more. Very good.”
○: “Discharge capacity maintenance ratio is 90% or more and less than 95%. Good”
Δ: “Discharge capacity maintenance rate is 85% or more and less than 90%. Usable.”
X: “Discharge capacity maintenance rate is less than 85%.

(Cycle characteristics (100 cycles, 200 cycles))
Similarly to 50 cycles, charge / discharge measurement was performed using a charge / discharge device (SM-8 manufactured by Hokuto Denko). These charge / discharge cycles are defined as one cycle, and charge / discharge of 100 cycles or 200 cycles is repeated, and “discharge capacity maintenance ratio (100 cycles or 200 cycles) = discharge capacity at 100th cycle or 200th cycle / discharge at the first cycle” The capacity was determined according to the following criteria according to the discharge capacity retention rate.
A: “Discharge capacity maintenance ratio is 90% or more. Very good.”
○: “Discharge capacity maintenance ratio is 85% or more and less than 90%. Very good.”
Δ: “Discharge capacity maintenance ratio is 80% or more and less than 85%. Good”
Δ: “Discharge capacity maintenance ratio is 75% or more and less than 80%. Usable.”
×: “Discharge capacity maintenance rate is less than 75%.

  In Tables 8 and 9, “storage stability (2) / (1)” means the ratio of “particle size of composite slurry stored at 40 ° C. for 4 days / particle size of composite slurry immediately after production”. The smaller the deviation from 1, the better the storage stability.

  As shown in Tables 8 and 9, it was confirmed that the composite slurry according to the present invention in Examples 18 to 34 was a composition excellent in dispersibility of the conductive additive and the active material. In particular, the dispersion (Examples 1 to 4, 6 to 8 and 10) in which the degree of polymerization of the polymer dispersant (A) is in the range of 10 to 350, and the addition amount of the polymer dispersant (A) are carbon. Dispersion (Examples 1 to 16) in an amount of 0.01 to 7.5% by mass relative to the material, and dispersions (Examples 12 to 15) using the polymer dispersant (A) and the derivative (D) in combination Compared to the comparative example, it was confirmed that the change in particle size when stored at 40 ° C. for 4 days was small, and the storage stability was excellent.

Moreover, in the battery using the electrode for secondary batteries formed from the composition for secondary battery electrode formation of this invention, it became clear that it is excellent in cycling characteristics (discharge capacity maintenance factor) with respect to the comparative example.
Furthermore, the composition for secondary battery electrode formation (Examples 18-21, 23-25, and 27) in which the polymerization degree of the polymer dispersant (A) is in the range of 10 to 350, and the polymer dispersant (A) In the composition for forming a secondary battery electrode (Examples 18 to 33) in which the amount of addition is 0.01 to 7.5% by mass with respect to the carbon material, the discharge capacity even after 100 cycles or 200 cycles have elapsed. It was confirmed that the maintenance ratio was high and good cycle characteristics were obtained.
Further, the ratio of the average particle size of the active material (G) to be used and the dispersed particle size (D50) of the carbon material (B) in the dispersion (average active material particle size / carbon material dispersed particle size (D50)). However, with respect to the present invention (Examples 21 to 35, 37) having 2 or more, there was a tendency that the cycle characteristics (discharge capacity retention rate) of the battery were improved.
Although the reason for the effect of improving the cycle characteristics in the examples is not clear, the use of the resin of the present invention has the effect of improving the dispersion stability of the carbon material dispersion and the mixture slurry. In addition, the presence of acidic functional groups in the vicinity of the surface of the carbon material and active material has a positive effect on the material distribution after drying, such as the formation of conductive paths, when a coated material using a mixture slurry is produced. In other words, it is assumed that the cycle characteristics are improved by increasing the film strength.

Claims (8)

A secondary comprising a polymer dispersant (A) having a structural unit (a-1) represented by the following general formula (1) and / or (2), and a carbon material (B) as a conductive aid. A composition for forming a battery electrode.
General formula (1)

[R ¹ represents hydrogen or a methyl group. R ² may have an alkylene group which may have a substituent, an alkenylene group which may have a substituent, an arylene group which may have a substituent, or may have a substituent. Represents a heteroarylene group. ]

General formula (2)

[R ¹ represents hydrogen or a methyl group. R ³ represents an alkylene group which may have a substituent, an arylene group which may have a substituent, or a heteroarylene group which may have a substituent, and R ⁴ represents a substituent. Represents an alkylene group which may have a substituent, an arylene group which may have a substituent, or a heteroarylene group which may have a substituent. ]
  The composition for forming a secondary battery electrode according to claim 1, wherein the degree of polymerization of the polymer dispersant (A) is 10 or more and 350 or less.   The composition for forming a secondary battery electrode according to claim 1 or 2, wherein the content of the polymer dispersant (A) is 0.01 to 7.5 mass% with respect to the carbon material (B).   Furthermore, an organic dye derivative having an acidic functional group, an organic dye derivative having a basic functional group, a triazine derivative having an acidic functional group (excluding organic dye derivatives) and a triazine derivative having an organic functional group (however, organic dye derivatives) The composition for forming a secondary battery electrode according to any one of claims 1 to 3, comprising one or more derivatives (D) selected from the group consisting of:   Furthermore, the composition for secondary battery electrode formation in any one of Claims 1-4 which contains a solvent (E) and a binder (F).   Further, the composition for forming a secondary battery electrode comprising the active material (G), wherein the ratio of the average particle size of the active material (G) / the dispersed particle size (D50) of the carbon material (B) is 2 It is 100 or less above, The composition for secondary battery electrode formation in any one of Claims 1-5.   An electrode having a composite material layer on a current collector, wherein the composite material layer is formed of the composition for forming a secondary battery electrode according to any one of claims 1 to 6.   A secondary battery comprising a positive electrode having a positive electrode mixture layer on a current collector, a negative electrode having a negative electrode mixture layer on a current collector, and an electrolyte, wherein at least one of the positive electrode and the negative electrode is claimed. Item 8. A secondary battery which is an electrode for a secondary battery according to Item 7.