JP2017016745A - Production method of conductive carbon material dispersion dissolving polyvinylidene fluoride based resin and its use - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production method of dispersion excellent in dispersion stability, and suppressing workability reduction involving long time dissolution of polyvinylidene fluoride based resin, when making a conductive carbon material dispersion, and to enhance temporal stability of a mixture slurry liquid for battery electrodes and the battery characteristics, by using the conductive carbon material dispersion.SOLUTION: A production method of dispersion containing a conductive carbon material (A), polyvinylidene fluoride based resin (B), a dispersant (C) and a good solvent (D) of polyvinylidene fluoride based resin, includes: a process (1) for obtaining a mixed powder (E) by mixing the conductive carbon material (A) and polyvinylidene fluoride based resin (B); a process (2) for adding the mixed powder (E) to the good solvent (D) of polyvinylidene fluoride based resin; a process (3) for dissolving the polyvinylidene fluoride based resin (B); and at least one of processes (4)-(6) for adding the dispersant (C).SELECTED DRAWING: None

Description

  The present invention relates to a method for producing a conductive carbon material dispersion in which a polyvinylidene fluoride resin used as an electrode forming binder used mainly in non-aqueous batteries such as lithium ion batteries is dissolved.

  In recent years, small portable electronic devices such as digital cameras and mobile phones have been widely used. These electronic devices have always been required to minimize the volume and reduce the weight, and the batteries to be mounted are also required to be small, light, and have a large capacity. Also, in large-sized secondary batteries for automobiles and the like, it is desired to realize a large non-aqueous electrolyte secondary battery instead of a conventional lead-acid battery.

  In order to meet such demands, lithium ion secondary batteries are being actively developed. As an electrode of a lithium ion secondary battery, a positive electrode in which an electrode mixture composed of a positive electrode active material containing lithium ions, a conductive additive, an organic binder, and the like is fixed to the surface of a metal foil current collector, and a lithium ion A negative electrode is used in which an electrode mixture made of a removable negative electrode active material, a conductive additive, an organic binder, and the like is fixed to the surface of a current collector of a metal foil.

  As a binder used in such a lithium ion secondary battery, it is important from the viewpoint of safety and long life that it can withstand the high output of the lithium ion secondary battery. For this reason, polyvinylidene fluoride resins that are excellent in chemical resistance, weather resistance, stain resistance and the like are widely used.

  Further, when a polyvinylidene fluoride resin is used as a binder, it is often prepared as a resin solution. As the method, a polyvinylidene fluoride resin formed in a powder state has a sufficient dissolving power for the resin. The solvent is selected by adding a resin to the solvent, and stirring and dissolving with heating as necessary.

However, since the polyvinylidene fluoride resin powder aggregates into a dumpling during stirring and prevents the solvent from penetrating into the aggregated resin, the resin is completely dissolved even with sufficient stirring force and heating. It took a long time to obtain a uniform solution.
The problem of the agglomeration of the polyvinylidene fluoride resin powder is mainly caused by the fact that the polyvinylidene fluoride resin powder is not sufficiently dispersed in the solvent, that is, the resin powder particles are close to each other. This is considered to be due to the fact that the surface is selectively dissolved and becomes paste-like due to contact with the solvent, resulting in agglomeration of adjacent powder particles.

  In order to deal with such a problem, in Patent Document 1, the conductive carbon material used for the lithium ion battery electrode and the polyvinylidene fluoride resin are mixed, and then added to a good solvent of the polyvinylidene fluoride resin, thereby forming the resin particles. A method for efficiently producing a dispersion of conductive carbon material in which polyvinylidene fluoride resin is dissolved while suppressing the occurrence of dumpling aggregation is disclosed. However, in this method, when the concentration is increased, the liquid viscosity becomes high, the workability is poor, the stability of the dispersion is lowered, and the obtained battery characteristics may be insufficient.

  Therefore, it is conceivable to use a dispersant as a method of increasing the concentration of the conductive carbon material dispersion in which the polyvinylidene fluoride resin is dissolved and improving the dispersion stability with time. For example, Patent Document 2 and Patent Document 3 disclose a composition containing a conductive carbon material, a polyvinylidene fluoride resin, a dispersant, and a solvent. In Patent Document 2, a method in which a polyvinylidene fluoride resin powder is added and dissolved in a liquid in which a carbon material is dispersed in the presence of a dispersant, a method in which a varnish liquid in which a polyvinylidene fluoride resin is dissolved in a solvent in advance is added, etc. However, in the former, there was a problem of agglomeration when the polyvinylidene fluoride resin powder was added, and in the latter, there was a problem that it took time to prepare the varnish in advance. Moreover, in patent document 2, there is no description regarding a specific manufacturing method.

JP2012-169059 WO2008 / 108360 JP2012-221568

  In view of the above situation, in the present invention, when preparing a conductive carbon material dispersion in which a polyvinylidene fluoride resin, which is mainly used for a non-aqueous battery such as a lithium ion battery, is prepared, it takes a long time to dissolve the polyvinylidene fluoride resin. It is an object to provide a method for producing a dispersion excellent in dispersion stability while suppressing deterioration in workability associated with crystallization. Another object of the present invention is to improve the temporal stability of the battery electrode mixture slurry liquid and to improve battery characteristics by using the conductive carbon material dispersion.

  In the production method in which the conductive carbon material used for the lithium ion battery electrode and the polyvinylidene fluoride resin are mixed and then added to the good solvent of the polyvinylidene fluoride resin, the present inventors use a dispersant together, and By using the dispersing agent, not only the dispersion stability of the conductive carbon material dispersion is excellent, but also the stability improvement of the electrode mixture slurry using the dispersion, and further found to improve the battery characteristics, The present invention has been reached.

That is, the present invention is a method for producing a dispersion containing a conductive carbon material (A), a polyvinylidene fluoride resin (B), a dispersant (C) and a good solvent (D) of a polyvinylidene fluoride resin, The step (1) of obtaining the mixed powder (E) by mixing the conductive carbon material (A) and the polyvinylidene fluoride resin (B); and the mixed powder (E) in the good solvent (D) of the polyvinylidene fluoride resin ) And a step (3) of dissolving the polyvinylidene fluoride resin (B), and including at least one of the following steps (4) to (6): The present invention relates to a method for producing a dispersion.
Step (4) A step of adding the dispersant (C) to the good solvent (D) in advance before the step (2).
Process (5) The process of adding a dispersing agent (C) to a good solvent (D) simultaneously with a process (2).
Step (6) A step of adding the dispersant (C) to the mixed powder (E) in advance before the step (2).

  Providing a conductive carbon material dispersion excellent in dispersion stability by using the method for producing a conductive carbon material dispersion in which the polyvinylidene fluoride resin of the present invention is dissolved, and an electrode mixture slurry excellent in dispersion stability It is possible to improve the characteristics of the battery using the dispersion.

<Conductive carbon material (A)>
The conductive carbon material in the present invention is not particularly limited as long as it is a conductive carbon material, but graphite, carbon black, carbon nanotube, carbon material nanofiber, carbon material fiber, fullerene, etc. are used alone. Alternatively, two or more types can be used in combination. 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 a gas as a raw material, and particularly various types such as acetylene black using an 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.

  Carbon black used as the conductive carbon material can be oxidized carbon. The oxidation treatment of carbon is carried out by treating the carbon at a high temperature in the air or by treating it with nitric acid, nitrogen dioxide, ozone, etc., for example, such as phenol group, quinone group, carboxy 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.

  Examples of commercially available carbon black include furnace black manufactured by Tokai Carbon Co., Ltd. such as Toka Black # 4300, # 4400, # 4500, and # 5500, furnace black manufactured by Degusa Co., Ltd. such as Printex L, Raven7000, 5750, 5250, 5000ULTRAIII. , And 5000 ULTRA, etc., Conductex SC ULTRA, Conductex 975 ULTRA, etc., PUER BLACK100, 115, 205 and other Colombian furnace blacks, # 2350, # 2400B, # 2600B, # 30050B, # 3230B, # 3230B, # 3350B, # 3350B # 3400B and # 5400B etc. Furnace Black, MONARCH1400, 1300, 900, VulcanXC- Furnace Black from Cabot, such as 2R and BlackPearls2000, Furnace Black from TIMCAL, such as Ensaco 250G, Ensaco 260G, Ensaco 350G, and SuperP-Li, Ketjen Black from Akzo, such as Ketjen Black EC-300J, and EC-600JD, And acetylene black by Denki Kagaku Kogyo Co., Ltd., such as Denka Black, Denka Black HS-100, FX-35, etc. are mentioned, However, It is not limited to these.

  In addition, the average primary particle size of carbon black used for the production of the dispersion is preferably 0.01 to 1 μm, particularly in the range of the average primary particle size of carbon black used for general dispersions and paints. 0.01 to 0.2 μm is preferable, and 0.01 to 0.1 μm is more preferable. The average primary particle size referred to here indicates an arithmetic average particle size measured with an electron microscope, and this physical property value is generally used to represent the physical characteristics of carbon black.

<Polyvinylidene fluoride resin (B)>
The polyvinylidene fluoride resin powder used in the present invention is a homopolymer or copolymer of vinylidene fluoride, and a powdery one formed by an emulsion polymerization method or a suspension polymerization method is preferably used.
Examples of commercially available polyvinylidene fluoride resin powder include KF polymer # W1100, W # 1300, W # 1700, W # 7200, W # 7300, W # 9100, W # 9200, W # 9300, and ARKEMA manufactured by Kureha Corporation. KYNAR 710/711, KYNAR 720/721, KYNAR 740/741, KYNAR 760/761, KYNAR 2850/2851, KYNAR 2800/2801, KYNAR 2820/2821, KYNAR 7201, and KYNAR 8301 are not limited to these.

<Dispersant (C)>
As the dispersant in the present invention, an ionic dispersant or a nonionic dispersant can be used.
Examples of the ionic dispersant include triazine derivatives and organic dye derivatives having an ionic functional group. Examples thereof include triazine derivatives having an acidic functional group, organic dye derivatives having an acidic functional group, triazine derivatives having a basic functional group, and organic dye derivatives having a basic functional group.
Examples of the nonionic dispersant include a polar functional group or a polymer compound having a polar structure, such as polyvinyl alcohol, polyvinyl acetals, polyvinyl pyrrolidone, polyalkylene oxide, polyvinyl ether, and cellulose resin. However, it is not limited to these. Moreover, a dispersing agent may be used independently and can also use 2 or more types together.

Triazine derivatives and organic dye derivatives having an ionic functional group are preferred because they are excellent in dispersibility with a small addition amount.
In addition, as the nonionic dispersant, polyvinyl acetals (particularly polyvinyl butyral) and polyvinyl alcohol are preferable because of excellent dispersibility, but use of polyvinyl alcohol having excellent resistance to an electrolytic solution is particularly preferable.

<Triazine derivatives and organic dye derivatives having acidic functional groups>
Among triazine derivatives and organic dye derivatives having an acidic functional group, in particular, triazine derivatives having an acidic functional group represented by the following general formula (1), or organic dye derivatives having an acidic functional group represented by the general formula (4) Is preferred. First, the triazine derivative having an acidic functional group represented by the general formula (1) will be described.

General formula (1)

[X ¹ is, -NH -, - O -, - CONH -, - SO 2 NH -, - CH 2 NH -, - CH 2 NHCOCH 2 NH- or -X ³ -Y-X ⁴ - represents, X ² and X ^4, each independently, represent -NH- or -O-, X ³ _{is, -CONH -, - SO 2 NH} -, - CH 2 NH -, - NHCO- or -NHSO ₂ - and represent , Y represents an alkylene group that may have a substituent, an alkenylene group that may have a substituent, or an arylene group that may have a substituent, Z represents —SO ₃ M, —COOM, -P (O) (-OM) ₂ or -O-P (O) (-OM) ₂ , M represents one equivalent of a 1 to 3 valent cation, and Q represents -O-R ² , —NH—R ² , a halogen group, —X ¹ —R ¹ or —X ² —Y—Z, wherein R ² represents a hydrogen atom or an alkyl group which may have a substituent. Or the alkenyl group which may have a substituent is represented. n represents an integer of 1 to 4. R ¹ represents an organic dye residue, 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 (2) Represents. ]

General formula (2)

[X ⁵ represents -NH- or -O-, X ⁶ and X ⁷ are each independently, -NH -, - O -, - CONH -, - SO 2 NH -, - CH 2 NH- or —CH ₂ NHCOCH ₂ NH—, wherein R ³ and R ⁴ are each independently an organic dye residue, a heterocyclic residue which may have a substituent, or an aromatic which may have a substituent. Represents a group ring residue or —Y—Z, and Y and Z have the same meanings as Y and Z in formula (1). ]

In the above, examples of the organic dye residue in R ¹ , R ³ and R ⁴ include diketopyrrolopyrrole dyes, azo dyes such as azo, disazo, polyazo, phthalocyanine dyes, anthraquinones, diaminodianthraquinones, anthra Anthraquinone dyes such as pyrimidine, flavantron, anthanthrone, indanthrone, pyranthrone, violanthrone, quinacridone dye, dioxazine dye, perinone dye, perylene dye, thioindigo dye, isoindoline dye, isoindolinone Residues such as dyes based on dyes, quinophthalone dyes, selenium dyes, metal complex dyes, and the like. 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.

In the above, examples of the heterocyclic residue and aromatic ring residue in R ¹ , R ³ , and R ⁴ include thiophene, furan, pyridine, pyrazole, pyrrole, imidazole, isoindoline, isoindolinone, and benzimidazole. Examples thereof include heterocyclic residues such as lone, 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 general formula (1) and general formula (2) represents an alkylene group, alkenylene group or arylene group which may have a substituent, but preferably has 20 or less carbon atoms, more preferably 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.

A preferred embodiment of the alkenyl group which may have an alkyl group and a substituted group which may have a substituent in R ² 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 (3) or a mixture.

General formula (3)

[R ⁵ , R ⁶ , R ⁷ and R ⁸ each independently have a hydrogen atom, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or a substituent. Represents a good aryl group. ]

R ⁵ , R ⁶ , R ⁷ and R ⁸ may be the same or different. Moreover, when R < ⁵ >, R < ⁶ >, R < ⁷ >, R < ⁸ > 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、−ＮＨ−、−Ｏ−、−ＣＯＮＨ−、−ＳＯ₂ＮＨ−、−ＣＨ₂ＮＨ−、−ＣＨ₂ＮＨＣＯＣＨ₂ＮＨ−、−Ｘ⁹−Ｙ−または−Ｘ⁹−Ｙ−Ｘ¹⁰−を表し、Ｘ⁹は、−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、Ｒ⁹は、有機色素残基を表し、ｎは、１〜４の整数を表す。］ Next, the organic dye derivative having an acidic functional group represented by the general formula (4) will be described.
General formula (4)

[X ⁸ is a direct bond, -NH -, - O -, - CONH -, - SO 2 NH -, - CH 2 NH -, - CH 2 NHCOCH 2 NH -, - X 9 -Y- or -X ⁹ -Y-X ¹⁰ - represents, X ⁹ _{is, -CONH -, - SO 2 NH} -, - CH 2 NH -, - NHCO- or -NHSO ₂ - represents, X ¹⁰ is, -NH- or -O Y represents an alkylene group that may have a substituent, an alkenylene group that may have a substituent, or an arylene group that may have a substituent, and Z represents —SO ₃ M, -COOM, -P (O) (-OM) ₂ or -O-P (O) (-OM) ₂ , M represents one equivalent of a 1 to 3 valent cation, and R ⁹ represents an organic dye residue. Represents a group, and n represents an integer of 1 to 4. ]

The organic dye residue of R ^{9 has} the same meaning as the organic dye residue in R ¹ , R ³ and R ⁴ described above. 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 (4) has the same meaning as M in the general formula (1).

  The method for synthesizing the triazine derivative and organic dye derivative having an acidic functional group used in the present invention is not particularly limited. For example, JP-B-39-28884, JP-B-45-11026, It can be synthesized by the methods described in JP-B-45-29755, JP-B-64-5070, JP-A-2004-217842, and the like.

<Triazine derivatives and organic dye derivatives having basic functional groups>
Among triazine derivatives and organic dye derivatives having a basic functional group, in particular, a triazine derivative having a basic functional group represented by the following general formula (101) or a basic functional group represented by the general formula (106) Organic dye derivatives are preferred. First, the triazine derivative having a basic functional group represented by the general formula (101) will be described.
Formula (101)

X ¹⁰¹ is, -NH -, - O -, - CONH -, - SO 2 NH -, - CH 2 NH -, - CH 2 NHCOCH 2 NH- or -X ¹⁰² -Y ¹ -X ¹⁰³ - represents, X ^102, -NH -, - O -, - CONH -, - SO 2 NH -, - CH 2 NH -, - NHCO- or -NHSO ₂ - represents, X ¹⁰³ is, -NH- or -O- and Y ¹ 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. .
P represents a group represented by any one of the general formula (102), the general formula (103), and the general formula (104).
Q ¹⁰¹ represents —O—R ¹⁰² , —NH—R ¹⁰² , a halogen group, —X ¹⁰¹ —R ^101, or a group represented by any one of the general formula (102), the general formula (103), and the general formula (104). Represents.
^R102 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 (102)

一般式（１０３）

General formula (103)

一般式（１０４）

General formula (104)

X ¹⁰⁴ represents a direct _{bond, -SO 2 -, - CO -} , - CH 2 NHCOCH 2 -, - CH 2 NHCONHCH 2 -, - CH 2 - or -X ¹⁰⁵ -Y ¹ -X ¹⁰⁶ - represents a. X ¹⁰⁵ represents -NH- or -O-, X ¹⁰⁶ represents a direct _{bond, -SO 2 -, - CO -} , - CH 2 NHCOCH 2 -, - CH 2 NHCONHCH 2 - or -CH ₂ - represents a .
v ¹ represents an integer of 1 to 10.
R ¹⁰³ and R ¹⁰⁴ represent respectively independently, a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkenyl group, an optionally substituted aryl group or a heterocyclic residue, R ¹⁰³ And R ¹⁰⁴ may combine to form a ring.
R ¹⁰⁵ , R ¹⁰⁶ , R ¹⁰⁷ and R ¹⁰⁸ each independently represents a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkenyl group or an optionally substituted aryl group.
R ¹⁰⁹ 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 ¹⁰¹ represents an organic dye residue, 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 (105). .
General formula (105)

T represents -X ¹⁰⁸ -R ^110, or W ^1, U represents -X ¹⁰⁹ -R ^111, or W ^2.
W ¹ and W ² each independently represent —O—R ¹⁰² , —NH—R ¹⁰² , a halogen group, or a group represented by any one of the general formula (102), the general formula (103), and the general formula (104). Represents.
X ¹⁰⁷ represents -NH- or -O-, X ¹⁰⁸ and X ¹⁰⁹ each independently, -NH -, - O -, - CONH -, - SO 2 NH -, - CH 2 NH- or - CH ₂ represents an NHCOCH ₂ NH-.
R ¹¹⁰ and R ¹¹¹ each independently represents an organic dye residue, an optionally substituted heterocyclic residue or an optionally substituted aromatic ring residue.

Examples of the organic dye residue in R ¹⁰¹ of the general formula (101) and R ¹¹⁰ and R ¹¹¹ of the general formula (105) include, for example, diketopyrrolopyrrole dyes, azo dyes such as azo, disazo, polyazo, and phthalocyanine dyes. Dyes, diaminodianthraquinones, anthrapyrimidines, flavantrons, anthanthrones, indantrons, pyranthrones, violanthrones, anthraquinone dyes, quinacridone dyes, dioxazine dyes, perinone dyes, perylene dyes, thioindigo dyes, iso Examples include residues such as indoline dyes, isoindolinone dyes, quinophthalone dyes, selenium dyes, metal complex dyes, and the like. 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 the aromatic ring residue in R ¹⁰¹ of the general formula (101) and R ¹¹⁰ and R ¹¹¹ of the general formula (105) include 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, alkoxy 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 ¹⁰³ and R ¹⁰⁴ represent respectively independently, a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkenyl group, an optionally substituted aryl group or a heterocyclic residue, R ¹⁰³ And R ¹⁰⁴ 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 ¹ in the general formula (101) and the general formula (105) 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.
Formula (106)

Ｚ¹⁰¹は、下記一般式（１０７）、一般式（１０８）または一般式（１０９）で示される基である。ｍは、１〜４の整数を表す。
一般式（１０７）

一般式（１０８）

Z ¹⁰¹ is a group represented by the following general formula (107), general formula (108), or general formula (109). m represents an integer of 1 to 4.
General formula (107)

Formula (108)

一般式（１０９）

General formula (109)

X ²⁴ represents a direct _{bond, -SO 2 -, - CO -} , - CH 2 NHCOCH 2 -, - CH 2 NHCONHCH 2 -, - CH 2 - or -X ²⁵ -Y ² -X ²⁶ - represents a. X ²⁵ represents -NH- or -O-, X ²⁶ represents a direct _{bond, -SO 2 -, - CO -} , - CH 2 NHCOCH 2 -, - CH 2 NHCONHCH 2 - or -CH ₂ - represents a . Y ² 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.
v ² represents an integer of 1 to 10.

R ²³ and R ²⁴ each independently represent a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkenyl group, an optionally substituted phenyl group or a heterocyclic residue, R ²³ And R ²⁴ 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 ²⁵ , R ²⁶ , R ²⁷ and R ²⁸ each independently represents a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkenyl group or an optionally substituted aryl group.
R ²⁹ represents an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted aryl group.

R ²² represents an organic dye residue, a heterocyclic residue which may have a substituent, and an aromatic ring residue which may have a substituent.
Examples of the organic dye residue in R ²² include diketopyrrolopyrrole dyes, azo dyes such as azo, disazo, polyazo, phthalocyanine dyes, diaminodianthraquinone, anthrapyrimidine, flavantron, 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 ²² 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, alkoxy 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 (102) to (104) and the general formulas (107) to (109) 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, Octylamine, N, N-methyloctadecylamine, didecylamine, diallylamine, N, N-ethyl-1,2-dimethylpropylamine, N, N-methylhexylamine, dioleylamine, distearylamine, N, N-dimethylamino Methylamine, 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-dibutylaminobutyl Ruamine, N, N-diisobutylaminopentylamine, N, N-methyl-laurylaminopropylamine, N, N-ethyl-hexylaminoethylamine, N, N-distearylaminoethylamine, N, N-dioleoylaminoethylamine, N, N-distearylaminobutylamine, piperidine, 2-pipecoline, 3-pipecoline, 4-pipecoline, 2,4-lupetidine, 2,6-lupetidine, 3,5-lupetidine, 3-piperidinemethanol, pipecolic acid, isonipecotine Acid, methyl isonicopetinate, ethyl isonicopetinate, 2-piperidineethanol, pyrrolidine, 3-hydroxypyrrolidine, N-aminoethylpiperidine, N-aminoethyl-4-pipecholine, N-aminoethylmorpholine, N-aminopropylpiperidi N-aminopropyl-2-pipecoline, N-aminopropyl-4-pipecoline, N-aminopropylmorpholine, N-methylpiperazine, N-butylpiperazine, N-methylhomopiperazine, 1-cyclopentylpiperazine, 1-amino Examples include -4-methylpiperazine and 1-cyclopentylpiperazine.

  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 formula (110) to formula (113) as 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.

Equation (110) -SO ₂ Cl
Formula (111) -COCl
Equation (112) -CH ₂ NHCOCH ₂ Cl
Equation (113) -CH ₂ Cl

In addition, for example, when a substituent represented by the formula (110) 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 (110) can be controlled.

  When introducing the substituent represented by the formula (111), first, an organic dye having a carboxy 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 between the substituent represented by formula (110) to formula (113) and the amine component, a part of the substituent represented by formula (110) to formula (113) is hydrolyzed, and chlorine is substituted with a hydroxyl group. There are things to do. In that case, the substituent represented by the formula (110) is a sulfo group, and the substituent represented by the formula (111) is a carboxy group, but any of them may be a free acid, or a 1 to 3 valent metal. Or you may form a salt with said amine.

When the organic dye is an azo dye, a substituent represented by the formula (107) to the formula (109) or the following general formula (114) is previously introduced into the diazo component or the coupling component, and then coupled. An azo organic dye derivative can also be produced by carrying out the reaction.
General formula (114)

X ¹⁰¹ is, -NH -, - O -, - CONH -, - SO 2 NH -, - CH 2 NH -, - CH 2 NHCOCH 2 NH- or -X ¹⁰² -Y ¹ -X ¹⁰³ - represents, X ^102, -NH -, - O -, - CONH -, - SO 2 NH -, - CH 2 NH -, - NHCO- or -NHSO ₂ - represents, X ¹⁰³ each independently -NH- or -O -Y ¹ is a C 1-20 alkylene group which may have a substituent, an alkenylene group which may have a substituent, or an arylene group which may have a substituent. Represents.
P represents a substituent represented by any one of the general formulas (102), (103) and the general formula (104).
Q ¹⁰¹ represents —O—R ¹⁰² , —NH—R ¹⁰² , a halogen group, —X ¹⁰¹ —R ^101, or a substitution represented by any of the general formulas (102), (103), or (104) Represents a group.
^R102 represents a hydrogen atom, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or an aryl group which 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 (107) to formula (109) or general formula (114). 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.

<Polyvinyl alcohol>
Although there is no restriction | limiting in particular about the manufacturing method of the polyvinyl alcohol used by this invention, Hereinafter, the polyvinyl alcohol obtained by saponifying this from polyvinyl acetate is described.
In general, polyvinyl alcohol is obtained by using polyvinyl acetate obtained by polymerizing vinyl acetate as a raw material, saponifying the polyvinyl acetate, and substituting the acetyl group with a hydroxyl group. Due to this synthesis process, polyvinyl alcohol has an acetyl group and a hydroxyl group, and the ratio is expressed as the degree of saponification.
In addition, the saponification degree in this invention represents the ratio (mol%) of the repeating unit represented by general formula (A) contained in polyvinyl alcohol. For example, in the case of polyvinyl alcohol obtained by saponifying polyvinyl acetate, the number of hydroxyl groups derived from the vinyl alcohol skeleton contained in the polyvinyl alcohol, the number of acetyl groups derived from the vinyl acetate skeleton and the number of hydroxyl groups derived from the vinyl alcohol skeleton The value divided by the sum of

  The polyvinyl alcohol used in the present invention is mainly polyvinyl alcohol obtained by saponifying polyvinyl ester, particularly polyvinyl acetate, but is not limited thereto. The saponification degree is preferably 50 to 95 mol%, more preferably 55 to 92 mol%, still more preferably 55 to 85 mol%, and particularly preferably 60 to 85 mol%. If it is the polyvinyl alcohol of the said saponification degree, various commercial products and synthetic products can be used individually or in combination of 2 or more types.

  Further, within the above range of saponification degree, as functional groups other than hydroxyl group and acetic acid group, for example, those introduced with acetoacetyl group, sulfo group, carboxy group, carbonyl group, amino group, isocyanate group, Modified by salts of the above, other anion or cation modified, unsaturated modified, acetal modified by aldehydes (butyral modified, acetoacetal modified, formal modified, etc.), diol structure introduced Are also included in the range of polyvinyl alcohol having a saponification degree of 50 to 95 mol% used in the present invention, and these can be used alone or in combination of two or more.

  Polyvinyl alcohol as a dispersant preferably has an average degree of polymerization of 50 to 4000, more preferably 100 to 3000, particularly preferably 100 to 2000, and still more preferably 100 to 1500. If it is polyvinyl alcohol of the said polymerization degree, various commercial products and synthetic products can be used individually or in combination of 2 or more types.

  Those having a saponification degree of less than 50 mol% are very good in solubility in NMP, but are considered to be ineffective for dispersion due to poor adsorption to carbon black, and those having a saponification degree of more than 95 mol% Since it hardly dissolves or swells in NMP, even if it is adsorbed to carbon black, the polymer chain cannot be extended to the NMP side, and therefore it is presumed that steric repulsion cannot be effectively performed. . On the other hand, those having a saponification degree of 50 to 95 mol% have a good balance between the solubility or swelling in NMP and the adsorptivity to carbon black and the steric repulsion effect after adsorption. It is considered to function particularly effectively.

  Examples of commercially available polyvinyl alcohols included in the saponification degree range include Kuraray Poval (polyvinyl alcohol manufactured by Kuraray Co., Ltd.), Gohsenol (polyvinyl alcohol manufactured by Nippon Gosei Kagaku Kogyo Co., Ltd.), Denka Poval (manufactured by Denki Kagaku Kogyo Co., Ltd.), J -Various grades can be obtained from the market under trade names such as POVAL (Nippon Vinegar-Poval).

  More specifically, Kuraray Poval PVA-403 (degree of saponification of 78.5 to 81.5 mol%, average degree of polymerization of 300, 4% aqueous solution viscosity at 20 ° C. according to JIS K6726 2.8 to 3.3 mPa · s ), Kuraray Poval PVA-505 (degree of saponification 72.5-74.5 mol%, average polymerization degree 500, 4% aqueous solution viscosity 4.2-5.0 mPa · s), Kuraray Poval L-8, Kuraray Poval L-9 Kuraraypoval L-9-78, Kuraraypoval L-10, Kuraraypoval C-506, Kuraraypoval KL-506, Gohsenol KL-03 (78.5-82.0 mol%, average polymerization degree 500 or less, 4% Aqueous solution viscosity 2.8-3.4 mPa · s), KL-05 (78.5-82.0 mol%, average polymerization degree 1000 or less, 4% aqueous solution viscosity 4.0) 5.0 mPa · s), NK-05R (71.0-75.0 mol%, average polymerization degree 1000 or less, 4% aqueous solution viscosity 4.5-5.5 mPa · s), KP-08R (71.0) -73.5 mol%, average polymerization degree 1000 or less, 4% aqueous solution viscosity 6.0-8.0 mPa · s) and the like, but are not limited thereto.

<Good solvent (D) of polyvinylidene fluoride resin (B)>
In the present invention, a step of producing a conductive carbon material in which a polyvinylidene fluoride-based resin (B) is added to a good solvent (sometimes referred to as “good solvent (D)”) and the polyvinylidene fluoride-based resin is dissolved is added. The “poor solvent” and “good solvent” defined herein are defined as follows.
Here, the terms “poor solvent” and “good solvent” generally refer to a theta (θ) temperature (obtained for a specific solvent for the polymer (in this case, the target polyvinylidene fluoride resin)). classification "antisolvent" things around room temperature where the second virial coefficient a ₂ of osmotic pressure of the polymer solvent becomes zero), what is extremely lower than room temperature (10 ° C.) as "good solvent" Used. The terms “antisolvent” and “good solvent” as used herein are also used in this definition.

  More specifically, the good solvent is generally a solvent in which the polyvinylidene fluoride resin is highly soluble, and among them, a nitrogen-containing polar solvent is preferably used. For example, solvents such as N-methyl-2-pyrrolidone, dimethylformamide, N, N-dimethylacetamide, N, N-dimethylsulfoxide are suitable. As the good solvent, these may be used alone or in combination of two or more.

<Mixed powder (E)>
In the present invention, a mixed powder obtained by mixing the conductive carbon material (A) and the polyvinylidene fluoride resin (B) is used.

<Conductive carbon material dispersion in which polyvinylidene fluoride resin is dissolved and method for producing the same>
The present invention relates to a method for producing a dispersion containing a conductive carbon material (A), a polyvinylidene fluoride resin (B), a dispersant (C), and a good solvent (D) of the polyvinylidene fluoride resin. Therefore, a method for rapidly producing a conductive carbon material dispersion in which a polyvinylidene fluoride resin is dissolved is proposed. The mechanism for achieving rapid dissolution of a polyvinylidene fluoride resin is as follows. Are considered. In general, the problem of agglomeration of polyvinylidene fluoride resin powder and the lengthening of working time associated with this phenomenon is mainly because the polyvinylidene fluoride resin powder is not sufficiently dispersed in the solvent, that is, The resin powder particles are in close proximity to each other and contact with the solvent, so that the surface is selectively dissolved to form a paste and the aggregate of the adjacent powder particles occurs. When the conductive carbon material is mixed between the polyvinylidene fluoride resin powder particles, the state in which the resin powder particles are close to each other is relaxed, and the dissolution efficiency of the polyvinylidene fluoride resin is improved. I think that it will improve remarkably.
In addition, the dispersion of the conductive carbon material is promoted by using the dispersant and the viscosity of the liquid is lowered, so that it is possible to prepare a higher concentration dispersion and to further devise the method of using the dispersant. Therefore, it is expected to improve the dispersion stability of the conductive carbon material dispersion, improve the stability of the electrode mixture slurry using the dispersion, and thus improve the performance of the battery using the dispersion.

The production method of the present invention mainly comprises the following three steps.
Step of obtaining mixed powder (E) by mixing conductive carbon material (A) and polyvinylidene fluoride resin (B) [Step (1)], good solvent for polyvinylidene fluoride resin (B) (D) The step of adding the mixed powder (E) to [Step (2)] and the step of dissolving the polyvinylidene fluoride resin (B) [Step (3)].

<Process (1): Preparation method of mixed powder (E)>
In this step, the conductive carbon material (A) and the polyvinylidene fluoride resin (B) are mixed to obtain a mixed powder (E). A commonly used mixing and dispersing machine can be used. For example, mixers such as tumblers, shakers, mixers, V-type mixers; mixers such as dispersers, Henschel mixers or planetary mixers; paint conditioners (manufactured by Red Devil), ball mills, attritors, etc. Media type dispersers, hybridizers (Nara Machinery Co., Ltd.), Mechano Micros (Nara Machinery Co., Ltd.), Mechano Fusion System AMS (Hosokawa Micron), or "MICROS" manufactured by Nara Machinery Co., Ltd. Less disperser; kneader and the like can be mentioned, but it is not limited to these. Only one type of mixing processing apparatus may be used, or a plurality of types of apparatuses may be used in combination.

  The conductive carbon material (A) and the polyvinylidene fluoride resin (B) are preferably mixed in a conductive carbon material: polyvinylidene fluoride resin = 90: 10 to 20:80 (mass ratio).

  Further, when preparing the mixed powder (E), at least part or all of the dispersant (C) used may be mixed with the conductive carbon material (A) and the polyvinylidene fluoride resin (B). Yes (step (6)).

<Step (2): Method of adding mixed powder (E) to good solvent (D)>
In this step, the mixed powder (E) prepared in step (1) is added while stirring the good solvent (D) of the polyvinylidene fluoride resin (B). As a good solvent (D), it can use individually or in mixture of 2 or more types.
At this time, before adding the mixed powder (E) prepared in the step (1), a part or all of the dispersant (C) can be added to the good solvent (D) (step (4)). )).
Further, at the same time when the mixed powder (E) prepared in the step (1) is added, a part or all of the dispersant (C) can be added to the good solvent (D) (step (5)).

<Step (3): Dissolution of polyvinylidene fluoride resin and dispersion method of conductive carbon material>
In this step, after the step (2), the polyvinylidene fluoride resin (B) is dissolved and the conductive carbon material (A) is dispersed.

  As an apparatus for dispersing the conductive carbon material (A) while dissolving the polyvinylidene fluoride resin (B), an agitator and a disperser that are usually used for dissolving and dispersing the resin can be used. For example, mixers such as dispersers, homomixers, planetary mixers, homogenizers ("Claremix" made by M Technique, "Flamix" made by PRIMIX, "Abramix" made by Silverson), paint conditioners (red Devil), ball mill, sand mill (Shinmaru Enterprises "Dino Mill", etc.), attritor, pearl mill (Eirich "DCP Mill", etc.), coball mill and other media type dispersers, wet jet mill (Genus) "Genus PY", Sugino Machine "Starburst", Nanomizer "Nanomizer", etc.) M Technic "Claire SS-5", Nara Machinery "MICROS", IKA "MKO Mixer" Medialess dispersers etc. It is, but not limited thereto. Moreover, it is preferable to use what gave the metal mixing prevention processing from the stirring and disperser used for resin dissolution. These devices may be used alone or in combination of a plurality of devices.

  In the production method of the present invention, the mixed powder (E) is added to the good solvent (D) (step (2)), and at the same time, at least a part or all of the dispersant (C) is added intermittently or continuously. It is desirable. As a method of adding the dispersing agent (C), simultaneously with the step (2), a method of adding the dispersing agent (C) intermittently or continuously to the good solvent (D) (step (5)), or A method of adding the dispersant (C) to the mixed powder (E) in advance before the step (2) (step (6)) can be mentioned.

Based on the above, methods that are more likely to be industrialized include 1) a mixed powder (E) of a conductive carbon material (A) and a polyvinylidene fluoride resin (B), and a dispersant (C). A method of adding a polyvinylidene fluoride resin (B) to which a benzene is added to a good solvent (D) and dissolving the polyvinylidene fluoride resin (B) and dispersing the conductive carbon material (A) [Production method (1) : Steps (1) to (3) and (4)], 2) A mixed powder (E) of the conductive carbon material (A) and the polyvinylidene fluoride resin (B), and the polyvinylidene fluoride resin (B). In addition to the good solvent (D), the dispersant (C) is added intermittently or continuously to the good solvent (D) to dissolve the polyvinylidene fluoride resin (B) and the conductive carbon material (A). [Distribution process (2): Steps (1) to (3)] And (5)], 3) a mixed solvent (E) of the conductive carbon material (A), the polyvinylidene fluoride resin (B) and the dispersant (C), and a good solvent for the polyvinylidene fluoride resin (B). A method of adding to (D) and dissolving polyvinylidene fluoride resin (B) and dispersing treatment of conductive carbon material (A) [Production method (3): steps (1) to (3) and (6)] .
In particular, the above production methods (2) and (3) are preferable because they are excellent in the dispersion stability of the conductive carbon material dispersion, the stability of the mixture slurry in battery applications described later, and the battery characteristics.
Although the reason why the various properties are superior in the production method (2) and the production method (3) over the production method (1) is not certain, like the production method (1), the dispersant (C) is previously added before the step (2). Rather than adding to the good solvent (D) and adding the conductive carbon material (A) to the good solvent (D), the addition of the conductive carbon material (A) as in production method (2) and production method (3) It seems that the addition of the dispersant (C) at the same time is because the action (for example, adsorption) of the dispersant on the conductive carbon material occurs more uniformly and the dispersion stability is further promoted.

  In this invention, it is preferable that the usage-amount of the dispersing agent (C) with respect to electroconductive carbon material (A) is 50 mass parts or less with respect to 100 mass parts of carbon materials, and is 0.5 mass part or more and 40 masses. Part or less, preferably 0.5 part by weight or more and 20 parts by weight or less, more preferably 1 part by weight or more and 15 parts by weight or less, further preferably 1 part by weight or more and 10 parts by weight or less, more preferably 1 part by weight or more. 8 parts by mass or less is particularly preferable.

<Use of the present invention>
Examples of the use of the conductive carbon material dispersion in which the polyvinylidene fluoride resin dissolved by the production method of the present invention is dissolved include electrodes for lithium ion secondary batteries, electrodes for electric double layer capacitors, primer layers for electrodes for lithium ion capacitors Furthermore, lithium transition metal composite oxides such as lithium cobaltate and lithium manganate, graphite, activated carbon, graphite, positive electrode active materials such as carbon nanotubes and carbon nanofibers and negative electrode active materials are added to prepare a mixture slurry for electrodes Then, the electrode for a lithium ion secondary battery, the electrode for an electric double layer capacitor, and the electrode for a lithium ion capacitor can be produced by coating and drying the current collector.

<Active material>
When using the dispersion manufactured by the manufacturing method of this invention for a battery electrode compound-material layer, a positive electrode active material or a negative electrode active material can be contained further.

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 preferably have an average particle diameter 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 as used herein is an average value of particle diameters of the active material measured with an electron microscope.

<Electrode>
By coating and drying the conductive carbon material dispersion containing the positive electrode active material or the negative electrode active material of the present invention on a current collector, a battery electrode mixture layer can be formed and an 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.

<Secondary battery>
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, sodium sulfur secondary batteries, lithium air secondary batteries, etc. In the secondary battery, conventionally known electrolytes, separators, and the like can be used as appropriate.

(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.

(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 detail based on an Example, this invention is not limited to a following example, unless the summary is exceeded. In this example, “part” represents “part by mass”, and “%” represents “% by mass”.
The materials used in the examples are shown below.

<Conductive carbon material (A)>
Denka black granular product (manufactured by Denki Kagaku Kogyo Co., Ltd.): Acetylene black, average primary particle size 35 nm, specific surface area 69 m ² / g, hereinafter abbreviated as “granular product”.
EC-300J (manufactured by Akzo): Ketjen black, average primary particle size 40 nm, specific surface area 800 m ² / g.
# 3400B (manufactured by Mitsubishi Chemical Corporation): furnace black, primary particle diameter 21 nm, specific surface area 165 m ² / g.
Super-P Li (manufactured by TIMCAL): furnace black. Primary particle diameter 40 nm, specific surface area 62 m ² / g.

<Polyvinylidene fluoride resin (B)>
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 # 7300 (manufactured by Kureha): polyvinylidene fluoride (PVDF), molecular weight: 1 million. Hereinafter, it may be abbreviated as “W # 7300”.

<Dispersant (C)>
Table 1 below shows the triazine derivative having an acidic functional group used as an ionic dispersant as “derivative A” and the triazine derivative having a basic functional group as “derivative B”.

Polyvinyl butyral, polyvinyl alcohol, and polyvinyl pyrrolidone were used as nonionic dispersants.
-ESREC BM-1 (manufactured by Sekisui Chemical Co., Ltd.): polyvinyl butyral, repeating unit containing a hydroxyl group: 24%, calculated molecular weight: 40,000, hereinafter sometimes abbreviated as “PVB”.
-Kuraray Poval PVA-505 (manufactured by Kuraray Co., Ltd.): Polyvinyl alcohol, saponification degree 73 mol%, average polymerization degree 500, and may be abbreviated as "PVA" hereinafter.
Polyvinylpyrrolidone K-30 (manufactured by Nippon Shokubai Co., Ltd.): Polyvinylpyrrolidone, hereinafter sometimes abbreviated as “PVP”.

<Good solvent (D)>
N-methyl-2-pyrrolidone was used as a good solvent for polyvinylidene fluoride. Hereinafter, it may be abbreviated as “NMP”.

<Active material>
Positive electrode active material: lithium cobaltate (LiCoO ₂ ), average particle size 6 μm. Hereinafter, it may be abbreviated as “LCO”.
Negative electrode active material: artificial graphite, average particle diameter of 18 μm, hereinafter abbreviated as “graphite”.
<Evaluation of dispersion>
The conductive carbon material dispersions obtained in Examples and Comparative Examples and the conductive carbon material dispersions (mixture slurry) containing an active material were evaluated by measuring the viscosity.

  The viscosity value was measured using a B-type viscometer (“BL” manufactured by Toki Sangyo Co., Ltd.), and the dispersion was sufficiently stirred with a spatula at a dispersion temperature of 25 ° C. and a B-type viscometer rotor rotating at 60 rpm. Then went immediately. The rotor used for the measurement is No. when the viscosity value is less than 100 mPa · s. No. 1 is 100 or more and less than 500 mPa · s. 2 is 500 or more and less than 2000 mPa · s. 3 is 2000 or more and less than 10,000 mPa · s. Four of each were used. The case where the obtained viscosity value was 10,000 mPa · s or more was described as “> 10000”, but this indicates that the viscosity was so high that it could not be evaluated with the B-type viscometer used for the evaluation. The lower the viscosity, the better the dispersibility, and the higher the viscosity, the poor the dispersibility. The storage stability was evaluated from the change in viscosity value after the conductive carbon material dispersion was stored at 60 ° C. for 10 days. Moreover, about the mixture slurry, it evaluated from the change of a viscosity value after leaving still and storing at 60 degreeC for 3 days. The smaller the change, the better the stability.

<Preparation of conductive carbon material dispersion>
(Conductive carbon material dispersions with different preparation processes and dispersant types)
[Example 1-1 to Example 1-5]
In accordance with the composition shown in Table 2 and the steps shown in Table 3, first, acetylene black (granular product) and polyvinylidene fluoride (W # 7300) were charged, and mixed and mixed for 30 minutes using a planetary mixer (manufactured by PRIMIX). A powder was prepared.
Separately, N-methyl-2-pyrrolidone (NMP) and various dispersants were mixed and sufficiently dissolved using a homomixer (manufactured by PRIMIX). The above mixed powder was added over 15 minutes while continuing to stir the resulting solution with a homomixer, and then treated with a homomixer for 1 hour to obtain a conductive carbon material dispersion.
Table 4 shows the evaluation results of the obtained dispersion.

[Example 2]
In accordance with the composition shown in Table 2 and the steps shown in Table 3, first, acetylene black (granular product) and polyvinylidene fluoride (W # 7300) were charged, and mixed and mixed for 30 minutes using a planetary mixer (manufactured by PRIMIX). A powder was prepared.
Separately, 1/3 of the predetermined amount of the dispersant (derivative A) was added to N-methyl-2-pyrrolidone (NMP) and sufficiently dissolved using a homomixer (manufactured by PRIMIX). While stirring the obtained solution with a homomixer, the above mixed powder and the remaining 2/3 of the dispersant (derivative A) were added simultaneously over 15 minutes, and then the treatment with the homomixer was performed for 1 hour. A conductive carbon material dispersion was obtained.
Table 4 shows the evaluation results of the obtained dispersion.

[Example 3-1 to Example 3-5]
In accordance with the composition shown in Table 2 and the steps shown in Table 3, first, acetylene black (granular product) and polyvinylidene fluoride (W # 7300) were charged, and mixed and mixed for 30 minutes using a planetary mixer (manufactured by PRIMIX). A powder was prepared.
Separately, while stirring N-methyl-2-pyrrolidone (NMP) with a homomixer (manufactured by PRIMIX), the above mixed powder and various dispersants were added simultaneously over 15 minutes, and then the treatment with the homomixer was performed for 1 hour. And a conductive carbon material dispersion was obtained.
Table 4 shows the evaluation results of the obtained dispersion.

[Example 4-1]
In accordance with the composition shown in Table 2 and the steps shown in Table 3, first, acetylene black (granular product), polyvinylidene fluoride (W # 7300) and a dispersant (derivative A) were charged, and a planetary mixer (manufactured by PRIMIX) Was mixed for 30 minutes to prepare a mixed powder.
Separately, while stirring N-methyl-2-pyrrolidone (NMP) with a homomixer (manufactured by PRIMIX), the above mixed powder was added over 15 minutes, and then the treatment with the homomixer was performed for 1 hour to obtain a conductive carbon material. A dispersion was obtained.
Table 4 shows the evaluation results of the obtained dispersion.

[Comparative Example 1]
In accordance with the composition shown in Table 2 and the steps shown in Table 3, first, acetylene black (granular product) and polyvinylidene fluoride (W # 7300) were charged, and mixed and mixed for 30 minutes using a planetary mixer (manufactured by PRIMIX). A powder was prepared.
Separately, while stirring N-methyl-2-pyrrolidone (NMP) with a homomixer (manufactured by PRIMIX), the above mixed powder was added over 15 minutes, and then the treatment with the homomixer was performed for 2 hours to obtain a conductive carbon material. A dispersion was obtained.
Table 4 shows the evaluation results of the obtained dispersion.

  From Table 4, the dispersion obtained in the Example obtained a dispersion having a viscosity lower than that of the Comparative Example in which the homomixer treatment was performed for 2 times. Moreover, the manufacturing method (Example 2, Examples 3-1 to 3) which adds a dispersing agent at the time of mixed powder addition rather than the manufacturing method (Examples 1-1 to 1-5) which dissolves a dispersing agent in a good solvent beforehand. −5, Example 4-1) showed a tendency that the temporal stability of the conductive carbon material dispersion was better.

(Dispersion of conductive carbon material with different composition)
(Dispersions using different types of conductive carbon materials and polyvinylidene fluoride)
[Example 4-2 to Example 4-8]
In accordance with the composition shown in Table 2 and the steps shown in Table 3, first, various conductive carbon materials, various polyvinylidene fluorides, and a dispersant (derivative A) were charged, and a planetary mixer (manufactured by PRIMIX) was used for 30 minutes. Mixed powder was prepared.
Separately, while stirring N-methyl-2-pyrrolidone (NMP) with a homomixer (manufactured by PRIMIX), the above mixed powder was added over 15 minutes, and then the treatment with the homomixer was performed for 1 hour to obtain a conductive carbon material. A dispersion was obtained.
Table 4 shows the evaluation results of the obtained dispersion.

  From Table 4, it was confirmed that all the dispersions had good stability over time, and that the production method of the present invention was effective even when the type of conductive carbon material and the type and composition of polyvinylidene fluoride were changed.

表中「ＣＢ」は導電性炭素材料を示す。
表中「ＰＶＤＦ」はポリフッ化ビニリデン系樹脂を示す。

In the table, “CB” indicates a conductive carbon material.
In the table, “PVDF” indicates a polyvinylidene fluoride resin.

表中「***」は未測定を示す。
比較例１は分散性が不十分で調製直後の粘度が高い為、貯蔵安定性の評価は未実施。

“***” in the table indicates no measurement.
Since Comparative Example 1 is insufficient in dispersibility and has a high viscosity immediately after preparation, evaluation of storage stability has not been performed.

<Preparation of Conductive Carbon Material Dispersion Containing Positive Electrode Active Material>
(Positive electrode mixture slurry)
[Examples 5-1 to 5-5, Example 6, Examples 7-1 to 7-5, Example 8]
According to the composition shown in Table 5, the various conductive carbon material dispersions obtained in Examples 1-1 to 1-5, Example 2, Examples 3-1 to 3-5, and Example 4-1 were homomixers. Lithium cobaltate (LCO), which is a positive electrode active material, was added while stirring with (made by PRIMIX), and then sufficiently mixed with a homomixer to obtain various positive electrode mixture slurries.
Table 6 shows the evaluation results of the obtained positive electrode mixture slurry.

[Comparative Example 2]
In accordance with the composition shown in Table 5, while stirring the conductive carbon material dispersion obtained in Comparative Example 1 with a homomixer (manufactured by PRIMIX), lithium cobaltate (LCO), which is a positive electrode active material, was added. The mixture was sufficiently mixed with a mixer to obtain various positive electrode mixture slurries.
Table 6 shows the evaluation results of the obtained positive electrode mixture slurry.

  From Table 6, a slurry having a lower viscosity than that of the comparative example was obtained as the positive electrode mixture slurry obtained in the examples. Moreover, the mixture slurry (Examples 5-1 to 5) using the conductive carbon material dispersions (Examples 1-1 to 1-5) made by a manufacturing method in which a dispersant is dissolved in a good solvent in advance. The conductive carbon material dispersions (Example 2, Examples 3-1 to 3-5, and Example 4-1) made by the manufacturing method of adding the dispersant when adding the mixed powder were used rather than -5). It was confirmed that the mixed slurry (Example 6, Examples 7-1 to 7-5, Example 8) had a lower viscosity and better stability over time.

表中「***」は未測定を示す。
比較例２は分散性が不十分で調製直後の粘度が高い為、貯蔵安定性の評価は未実施。

“***” in the table indicates no measurement.
Since Comparative Example 2 is insufficient in dispersibility and has a high viscosity immediately after preparation, evaluation of storage stability has not been performed.

<Preparation of Conductive Carbon Material Dispersion Containing Negative Electrode Active Material>
(Negative electrode mixture slurry)
[Example 9, Example 10]
In accordance with the composition shown in Table 7, while stirring the various conductive carbon material dispersions obtained in Example 1-1 and Example 3-1 with a homomixer (manufactured by PRIMIX), artificial graphite (graphite as a negative electrode active material) ) And then mixed well with a homomixer to obtain various negative electrode mixture slurries.
Table 8 shows the evaluation results of the obtained negative electrode mixture slurry.

[Comparative Example 3]
In accordance with the composition shown in Table 7, while stirring the conductive carbon material dispersion obtained in Comparative Example 1 with a homomixer (manufactured by PRIMIX), artificial graphite (graphite) as a negative active material was added, and then the homomixer was added. Was sufficiently mixed to obtain a negative electrode mixture slurry.
Table 8 shows the evaluation results of the obtained negative electrode mixture slurry.

  As shown in Table 8, the negative electrode mixture slurry obtained in Examples was a slurry having a viscosity lower than that of Comparative Examples. In addition, the mixed powder is more added than the mixed slurry (Example 9) using the conductive carbon material dispersion (Example 1-1) made by a method of dissolving the dispersant in advance in a good solvent. It was confirmed that the mixed material slurry (Example 10) using the conductive carbon material dispersion (Example 3-1) made by the manufacturing method in which the dispersant was added had a lower viscosity and better stability over time. It was done.

表中「***」は未測定を示す。
比較例３は分散性が不十分で調製直後の粘度が高い為、貯蔵安定性の評価は未実施。

“***” in the table indicates no measurement.
Since Comparative Example 3 was insufficient in dispersibility and had a high viscosity immediately after preparation, evaluation of storage stability was not performed.

<Assembly of lithium ion secondary battery positive electrode evaluation cell>
[Examples 11-1 to 11-5, Example 12, Examples 13-1 to 13-5, Example 14, and Comparative Example 4]
The previously prepared battery electrode mixture slurry (the positive electrode mixture slurry of Examples 5-1 to 5-5, Example 6, Examples 7-1 to 7-5, Example 8, and Comparative Example 2) was collected. After applying using a doctor blade on an aluminum foil with a thickness of 20 μm to be an electrical conductor, heat drying at 120 ° C. under reduced pressure, and then rolling with a roller press to produce a positive electrode mixture layer with a thickness of 100 μm. did. This was punched into a diameter of 9 mm, and a metallic lithium foil (thickness: 0.15 mm) was used as a counter electrode, and a separator made of a porous polypropylene film was inserted and laminated between the working electrode and the counter electrode, and an electrolyte solution (ethylene carbonate and diethyl carbonate). A bipolar electrode type metal cell (HS flat cell manufactured by Hosen Co., Ltd.) was assembled by filling a mixed solvent in which carbonate was mixed at a volume ratio of 1: 1 with a nonaqueous electrolytic solution in which LiPF ₆ was dissolved at a concentration of 1M. The cell was assembled in a glove box substituted with argon gas.

<Assembly of lithium ion secondary battery negative electrode evaluation cell>
[Example 15, Example 16, Comparative Example 5]
After applying the previously prepared battery electrode mixture slurry (negative electrode mixture slurry of Examples 9, 10 and Comparative Example 3) onto a 20 μm thick copper foil serving as a current collector using a doctor blade After heating and drying at 120 ° C. under reduced pressure, the product was rolled with a roller press to produce a negative electrode mixture layer having a thickness of 100 μm. This was punched into a diameter of 9 mm, and a metallic lithium foil (thickness: 0.15 mm) was used as a counter electrode, and a separator made of a porous polypropylene film was inserted and laminated between the working electrode and the counter electrode, and an electrolyte solution (ethylene carbonate and diethyl carbonate). A bipolar electrode type metal cell (HS flat cell manufactured by Hosen Co., Ltd.) was assembled by filling a mixed solvent in which carbonate was mixed at a volume ratio of 1: 1 with a nonaqueous electrolytic solution in which LiPF ₆ was dissolved at a concentration of 1M. The cell was assembled in a glove box substituted with argon gas.

<Characteristic evaluation of lithium ion secondary battery positive electrode>
Using the charging / discharging device (SM-8 manufactured by Hokuto Denko Co., Ltd.) at 40 ° C., the prepared positive electrode evaluation cell was fully charged with constant current and constant voltage charging (upper limit voltage 4.2 V) at a charging rate of 1.0 C. The charge / discharge for discharging to the discharge lower limit voltage of 3.0 V at a constant current at the same rate as the charge was defined as one cycle (charge / discharge interval pause time 30 minutes), and this cycle was performed for a total of 50 cycles to perform charge / discharge. . Further, the capacity maintenance ratio is a percentage of the discharge capacity at the 50th cycle with respect to the discharge capacity at the first cycle, the capacity maintenance ratio is 95% or more, and the capacity maintenance ratio is 90 or more and less than 95%. A case where the capacity retention rate was 85% or more and less than 90% was evaluated as Δ, and a case where the capacity retention rate was less than 85% was evaluated as x. The evaluation results are shown in Table 9.

  From Table 9, Examples 11-1 to 11-5, Example 12, Examples 13-1 to 13-5, and Example 14 using the conductive carbon material dispersion of the present invention were compared with Comparative Example 4. The capacity retention rate after 50 cycles was good.

<Evaluation of lithium ion secondary battery negative electrode characteristics>
Using the charging / discharging device (SM-8 manufactured by Hokuto Denko Co., Ltd.) at 40 ° C., the prepared negative electrode evaluation cell was fully charged with constant current and constant voltage charging (lower limit voltage 0.01 V) at a charging rate of 1.0 C. Charging / discharging is performed at a constant current at the same rate as during charging until the voltage reaches 1.5 V, and one cycle (charging / discharging interval pause time 30 minutes) is performed, and this cycle is performed for a total of 50 cycles. It was. Further, the capacity maintenance ratio is a percentage of the discharge capacity at the 50th cycle with respect to the discharge capacity at the first cycle, the capacity maintenance ratio is 95% or more, and the capacity maintenance ratio is 90 or more and less than 95%. A case where the capacity retention rate was 85% or more and less than 90% was evaluated as Δ, and a case where the capacity retention rate was less than 85% was evaluated as x.
The evaluation results are shown in Table 10.

  From Table 10, the capacity retention rate after 50 cycles was good as compared with Example 15, Example 16, and Comparative Example 5 using the conductive carbon material dispersion of the present invention.

Claims (1)

A method for producing a dispersion containing a conductive carbon material (A), a polyvinylidene fluoride resin (B), a dispersant (C), and a good solvent (D) of the polyvinylidene fluoride resin,
A step (1) of obtaining a mixed powder (E) by mixing the conductive carbon material (A) and the polyvinylidene fluoride resin (B);
A step (2) of adding the mixed powder (E) to the good solvent (D) of the polyvinylidene fluoride resin;
Step (3) for dissolving the polyvinylidene fluoride resin (B)
And a process for producing a dispersion comprising at least one of the following steps (4) to (6):
Step (4) A step of adding the dispersant (C) to the good solvent (D) in advance before the step (2).
Process (5) The process of adding a dispersing agent (C) to a good solvent (D) simultaneously with a process (2).
Step (6) A step of adding the dispersant (C) to the mixed powder (E) in advance before the step (2).