JP5799486B2 - Carbon material dispersion - Google Patents

Description

  The present invention relates to a carbon material dispersion excellent in dispersibility and storage stability. Moreover, it is related with the composition for display coatings prepared using this dispersion liquid. Furthermore, the present invention relates to a battery electrode in which an electrode mixture layer is formed using the dispersion, and a lithium ion secondary battery in which at least one of a positive electrode and a negative electrode is the electrode.

  Carbon materials are used in a wide range of fields such as printing pigments, inkjet inks, inks for writing instruments, paints, and plastic forming materials as coloring pigments, light-shielding materials, and conductive materials. In order to satisfy this, it is important to finely disperse the carbon material in an organic solvent.

  Regarding the dispersion of carbon black, there is a method of dispersing using various additives, for example, a dispersant such as a surfactant or a pigment dispersion resin. However, dispersion with a surfactant is advantageous for dispersion in an aqueous system because it uses electrostatic repulsion between ionized polar functional groups to stabilize the dispersion, but in an organic solvent having a dielectric constant lower than that of water. In the dispersion in an organic solvent, a method using a pigment dispersion resin has been generally employed as disclosed in Patent Document 1 and Patent Document 2. In this method, the dispersion resin is adsorbed on the surface of the carbon black particles, and the dispersion is stabilized by utilizing the steric repulsion between the adsorption resins. However, even in this case, if the interaction between the carbon black surface and the dispersion resin is insufficient, the resin is desorbed and easily re-aggregates. In addition, general carbon black has a small amount of surface functional groups that interact with the resin, and many particles have a very small particle size and a large specific surface area, so that a large amount of dispersed resin is required for stabilization. In addition, if the amount of the dispersed resin increases, the amount of the resin or additive that can be added to impart ink or paint suitability is limited, or the compatibility between the dispersed resin and these additives is poor. In such a case, there is a problem that aggregation due to a thinning shock and stability with time of the ink and paint are lowered.

  Therefore, for the purpose of improving dispersibility, a method of introducing an acidic functional group onto the particle surface by oxidizing carbon black in a gas phase or a liquid phase has been studied. However, gas phase oxidation such as plasma and ozone treatment has problems such as low processing efficiency and expensive processing equipment, and liquid phase processing uses strong acids such as nitric acid and hydrogen peroxide. There is a problem with sex. Especially for carbon black oxidized by nitric acid treatment, the problem of mutagenesis has been pointed out.

  Further, Patent Document 3 discloses a method in which an amine is used as a dispersant and is adsorbed on carbon black by acid-base interaction with a functional group on the surface of carbon black to increase the affinity with the resin. However, if the amount of functional groups on the surface of the carbon black is small, amine adsorption is insufficient, so there is a problem that the selection of the carbon black is limited, and the use of a resin containing acidic functional groups is desirable. There remains a problem that the degree of freedom of the final paint and ink composition is narrowed.

  On the other hand, a method of carrying out dispersion using a pigment resin having an organic dye residue, an anthraquinone residue or a triazine residue as a base skeleton as a side chain and an acidic group or basic group as a substituent, and a dispersion resin, It is disclosed in Patent Document 4. The action mechanism of these organic dye derivatives, anthraquinone derivatives or triazine derivatives is that the polar functional groups of various derivatives interact with the polar functional groups of the resin, such as acid-base reactions and hydrogen bonds. When the eluate is adsorbed to carbon black using an organic dye residue, anthraquinone residue, or triazine residue as an adsorption site, the resin layer exhibits a steric repulsion effect and stabilizes the dispersion of carbon black. It is considered. In this method, in most cases, an ink or a resin for coating can be used as a dispersion resin as it is, so that there is no compatibility problem caused by the dispersant and excellent versatility. However, in applications that require extremely high dispersion, such as paints for color filters and inkjet inks, sufficient dispersion is often not obtained unless a dispersion resin is used in combination. There remains a problem that compatibility with additives and the degree of freedom of final paint / ink composition are narrowed.

  Therefore, as a method for producing a carbon black dispersion without using a resin, Patent Document 5 discloses a method of adsorbing an organic dye derivative or triazine derivative having a basic functional group and carbon black in an organic solvent in the presence of an acid. It is disclosed. Since this method does not use a dispersion resin, a dispersion having excellent compatibility can be obtained. However, since the dispersion stability of carbon black is ensured by the combined use of a derivative and an acid, an acid may be added by an additive during coating. When carbon black is neutralized, carbon black is re-agglomerated. Further, it is necessary to use a protic solvent in combination as a solvent used for dispersion. For example, it is considered that dispersion is difficult in the case of an electron donating solvent alone.

  Carbon nanotubes have characteristics such as high conductivity and mechanical strength, so they can store various types of gas such as fuel cells, electrodes, electromagnetic shielding materials, conductive resins, field emission display (FED) members, and hydrogen. Expected to be used in a wide range of fields such as materials. When carbon nanotubes and carbon nanofibers are used, it is preferable that they are finely dispersed in the solution without being entangled with each other, but they are highly cohesive and generally difficult to disperse.

  As an attempt to improve the dispersibility of carbon nanotubes, Patent Document 6 discloses a method using a surfactant as a dispersant. However, this method uses a surfactant in an amount of about 50 wt% with respect to the carbon nanotubes. Even if a coating film is added to the obtained dispersion to create a coating film, it contributes to curing. The surfactant that does not reduce the hardness and resistance of the coating film.

  In view of the above problems, an object of the present invention is to provide a carbon material dispersion excellent in dispersibility and storage stability without using a dispersion resin.

JP 7-268268 A JP 2001-192595 A Japanese Patent Laid-Open No. 11-256068 JP 2001-172530 A Japanese Patent Laid-Open No. 2005-213405 JP 2003-238126 A

  To provide a carbon material dispersion excellent in dispersibility and storage stability without using a dispersion resin.

  As a result of intensive studies, the present inventors have dispersed a carbon material in an organic solvent in the presence of an organic dye derivative having a basic functional group or a triazine derivative having a basic functional group and a base having a molecular weight of 300 or less. Thus, it was found that a carbon material dispersion excellent in dispersibility and storage stability can be prepared without using a dispersion resin, and the present invention has been achieved.

That is, the present invention is a carbon material dispersion comprising an organic dye derivative having a basic functional group or a triazine derivative having a basic functional group, a base having a molecular weight of 300 or less, a carbon material, and an organic solvent,
The organic dye derivative having a basic functional group is an organic dye derivative represented by the following general formula (6),
The amount of the derivative added is 1 part by weight or more and 20 parts by weight or less with respect to 100 parts by weight of the carbon material,
The amount of the base added is 0.1 to 10 equivalents relative to the derivative,
The present invention relates to a carbon material dispersion, wherein the carbon material is at least one carbon material selected from the group consisting of neutral carbon black, carbon nanotubes, and carbon nanofibers.

General formula (6):

Z is at least one selected from the group represented by the following general formula (7), (8) or general formula (9). n represents an integer of 1 to 4.

General formula (7):
General formula (8):
General formula (9):

X ₄ is a direct _{bond, -SO 2 -, - CO -} , - CH 2 NHCOCH 2 -, - CH 2 NHCONHCH 2 -, - CH 2 - or, -X ₅ -Y-X ₆ - represents a. X ₅ is -NH- or represents -O-, X ₆ represents a direct _{bond, -SO 2 -, - CO -} , - CH 2 NHCOCH 2 -, - CH 2 NHCONHCH 2 - or -CH ₂ - Represents. Y 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, having 1 to 20 carbon atoms.
v represents an integer of 1 to 10.
R ₃ and R ₄ are each independently a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkenyl group, an optionally substituted aryl group, or R ₃ and R ₄ together. Represents an optionally substituted heterocyclic residue containing additional nitrogen, oxygen or sulfur atoms.
R ₅ , R ₆ , R ₇ and R ₈ each independently represents a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkenyl group or an optionally substituted aryl group.
R ₉ represents an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted aryl group.
R ₁₂ represents an organic dye residue.
The organic dye residue represented by R ₁₂ is diketopyrrolopyrrole dye, azo, disazo, polyazo azo dye, phthalocyanine dye, diaminodianthraquinone, anthrapyrimidine, flavantron, anthanthrone, indanthrone, pyranthrone. These are residues of anthraquinone dyes and quinacridone dyes of violanthrone.

The present invention also relates to a carbon material dispersion in which the base is an amine.
The present invention also relates to a carbon material dispersion in which the organic solvent has a relative dielectric constant of 10 or more.
The present invention also relates to a carbon material dispersion in which the organic solvent has a donor number of 15 Kcal / mol or more.

  Moreover, this invention relates to the composition for display coatings prepared using said carbon material dispersion liquid.

Moreover, this invention relates to the electrode for batteries in which the electrode compound-material layer was formed using said carbon material dispersion liquid.
The present invention is a lithium ion 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 containing lithium, At least one of a positive electrode and a negative electrode is related with the lithium ion secondary battery which is said battery electrode.

  According to the present invention, a dispersion of a carbon material having good dispersibility and storage stability can be obtained without using a dispersion resin.

  The carbon material dispersion in the present invention includes a carbon material, an organic dye derivative having a basic functional group or a triazine derivative having a basic functional group, a base having a molecular weight of 300 or less, and an organic solvent. The details will be described below.

<Carbon material>
The carbon material used in the present invention is not particularly limited, and graphite, carbon black, carbon nanotube, carbon nanofiber, carbon fiber, fullerene, etc. can be used alone or in combination of two or more. . A carbon material suitable for the application can be selected from the viewpoints of color, concealability, conductivity, availability, and cost.

  As the carbon black used in the present invention, various types such as commercially available furnace black, channel black, thermal black, acetylene black, ketjen black and the like can be used. Ordinarily oxidized carbon black or hollow carbon can be used. However, in view of the adsorptivity and desorption properties of the organic dye derivative or triazine derivative, neutral carbon having fewer functional groups is preferable. The particle size of carbon black is preferably 0.01 to 1 μm, and particularly preferably 0.01 to 0.2 μm, as in the particle size range of carbon black used in ordinary inks and paints. However, the particle size referred to here indicates an average primary particle size measured with an electron microscope or the like, and the physical property values are generally used to represent the physical characteristics of carbon black.

  The carbon nanotube used in the present invention is a carbon material having a shape obtained by winding graphite in a cylindrical shape, and has a diameter of about several nm to 100 nm and a length of about several nm to 1 mm. In order to exhibit semiconductor characteristics, transparency of the coating film, etc., the diameter is preferably 50 nm or less, particularly preferably 20 nm or less. The length is preferably from 100 nm to 1 mm, particularly preferably from 500 nm to 1 mm. There are single-walled carbon nanotubes and multi-walled carbon nanotubes, but any structure may be used. Further, those having a fiber diameter of about 100 nm to 1 μm, which are classified as carbon nanofibers, can also be used.

<Organic dye derivative having basic functional group or triazine derivative having basic functional group>
In the present invention, an organic dye derivative having a basic functional group or a triazine derivative having a basic functional group is used. In particular, use of a triazine derivative represented by the following general formula (1) or an organic dye derivative represented by the following general formula (6) is preferable.

General formula (1):

X _{1 is, -NH -, - O -,} - CONH -, - SO 2 NH -, - CH 2 NH -, - CH 2 NHCOCH 2 NH- or _-X 2 _{-Y-X 3} - represents, _{X 2 is, -NH -, - O -,} - CONH -, - SO 2 NH -, - CH 2 NH -, - NHCO- or -NHSO ₂ - represents, _{X 3} each independently -NH- or, -O -Y 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. Represent.
P represents a substituent represented by any one of the general formulas (2), (3) and the general formula (4).
Q is —O—R ₂ , —NH—R ₂ , a halogen group, —X ₁ —R _1, or a substituent represented by any one of the general formulas (2), (3), or (4) Represents.
R ₂ 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 (2):

General formula (3):

General formula (4):

X ₄ is a direct _{bond, -SO 2 -, - CO -} , - CH 2 NHCOCH 2 -, - CH 2 NHCONHCH 2 -, - CH 2 - _or, -X 5 _{-Y-X 6} - represents a. X ₅ is -NH- or represents -O-, _{X 6} represents a direct _{bond, -SO 2 -, - CO -} , - CH 2 NHCOCH 2 -, - CH 2 NHCONHCH 2 - or -CH ₂ - Represents. Y 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, having 1 to 20 carbon atoms.
v represents an integer of 1 to 10.
R ₃ and R ₄ are each independently a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkenyl group, an optionally substituted aryl group, or R ₃ and R _4. Represents an optionally substituted heterocyclic residue containing additional nitrogen, oxygen or sulfur atoms.
R ₅ , R ₆ , R ₇ and R ₈ each independently represents a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkenyl group or an optionally substituted aryl group.
R ₉ represents an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted aryl group.
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 (5).

General formula (5):

T _is -X 8 _{-R 10} or represents _{W 1,} U _represents -X 9 _{-R 11} or _{W 2.}
W ₁ and W ₂ are each independently —O—R ₂ , —NH—R ₂ , a halogen group, or a substituent represented by any one of General Formula (2), (3), or General Formula (4) Represents.
R ₂ 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.
X ₇ represents an -NH- or -O-, _{X 8} and _{X 9} are each independently -NH -, - O -, - CONH -, - SO 2 NH -, - CH 2 NH- or -CH ₂ NHCOCH ₂ NH— is represented.
Y 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 has 1 to 20 carbon atoms.
R ₁₀ and R ₁₁ each independently 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 represented by R _{1 in the} general formula (1) and R ₁₀ and R ₁₁ in the general formula (5) include azo dyes such as diketopyrrolopyrrole dyes, azo, disazo, and polyazo. Anthraquinone dyes such as phthalocyanine dyes, diaminodianthraquinones, anthrapyrimidines, flavantrons, anthanthrones, indantrons, pyrantrons, violanthrones, quinacridone dyes, dioxazine dyes, perinone dyes, perylene dyes, thioindigo dyes And dyes, isoindoline dyes, isoindolinone dyes, quinophthalone dyes, selenium dyes, metal complex dyes, and the like.

Examples of the heterocyclic residue and aromatic ring residue represented by R _{1 in the} general formula (1) and R ₁₀ and R ₁₁ in the general formula (5) include thiophene, furan, pyridine, pyrazine, triazine, Examples include pyrazole, pyrrole, imidazole, isoindoline, isoindolinone, benzimidazolone, benzthiazole, benztriazole, indole, quinoline, carbazole, acridine, benzene, naphthalene, anthracene, fluorene, phenanthrene, anthraquinone, and acridone. 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.

  Y in the general formula (1) and the general formula (5) represents an alkylene group, an alkenylene group or an arylene group which may have a substituent having 20 or less carbon atoms, but may preferably be substituted. Examples include a phenylene group, a biphenylene group, a naphthylene group, or an alkylene group that may have a side chain having 10 or less carbon atoms.

General formula (6):

Z is at least one selected from the group represented by the following general formula (7), (8) or general formula (9). n represents an integer of 1 to 4.

General formula (7):

General formula (8):

General formula (9):

X ₄ is a direct _{bond, -SO 2 -, - CO -} , - CH 2 NHCOCH 2 -, - CH 2 NHCONHCH 2 -, - CH 2 - _or, -X 5 _{-Y-X 6} - represents a. X ₅ is -NH- or represents -O-, _{X 6} represents a direct _{bond, -SO 2 -, - CO -} , - CH 2 NHCOCH 2 -, - CH 2 NHCONHCH 2 - or -CH ₂ - Represents. Y 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, having 1 to 20 carbon atoms.
v represents an integer of 1 to 10.

R ₃ and R ₄ are each independently a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkenyl group, an optionally substituted aryl group, or R ₃ and R ₄ together. Represents an optionally substituted heterocyclic residue containing additional nitrogen, oxygen or sulfur atoms.
R ₅ , R ₆ , R ₇ and R ₈ each independently represents a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkenyl group or an optionally substituted aryl group.
R ₉ represents an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted aryl group.
R ₁₂ represents an organic dye residue.
Examples of the organic dye residue represented by R ₁₂ include diketopyrrolopyrrole dyes, azo dyes such as azo, disazo, polyazo, phthalocyanine dyes, diaminodianthraquinone, anthrapyrimidine, flavantrons, anthanthrones, indans. Anthraquinone dyes such as Thoron, Pyrantron and Violantrone, quinacridone dyes and the like can be mentioned.

  Examples of the amine component used for forming the substituents represented by the general formulas (2) to (4) and the general formulas (6) to (8) include dimethylamine, diethylamine, methylethylamine, N, N-ethylisopropylamine, N, N-ethylpropylamine, N, N-methylbutylamine, N, N-methylisobutylamine, N, N-butylethylamine, N, N-tert-butylethylamine, diisopropylamine, dipropyl Amine, N, N-sec-butylpropylamine, dibutylamine, di-sec-butylamine, diisobutylamine, N, N-isobutyl-sec-butylamine, diamylamine, diisoamylamine, dihexylamine, dicyclohexylamine, di (2- Ethylhexyl) amine, dioctylami N, N-methyloctadecylamine, didecylamine, diallylamine, N, N-ethyl-1,2-dimethylpropylamine, N, N-methylhexylamine, dioleylamine, distearylamine, N, N-dimethylaminomethylamine 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-laurylaminopropylamine, N, N-ethyl-hexylaminoethylamine, N, N-distearylaminoethylamine, N, N-dioleylaminoethylamine, N, N- Distearylaminobutylamine, piperidine, 2-pipecoline, 3-pipecoline, 4-pipecoline, 2,4-lupetidine, 2,6-lupetidine, 3,5-lupetidine, 3-piperidinemethanol, pipecolic acid, isonipecotic acid, isonicopetic acid Methyl, ethyl isonicopetinate, 2-piperidineethanol, pyrrolidine, 3-hydroxypyrrolidine, N-aminoethylpiperidine, N-aminoethyl-4-pipecholine, N-aminoethylmorpholine, N-aminopropylpiperidine, N-amino Propyl-2-pipecholine, N-aminopropyl-4-pipecoline, N-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-. 118462, JP 56-166266, JP 60-88185, JP 63-305173, JP 3-2676, JP 11-199796, and the like. It can be synthesized by the method.

For example, after introducing the substituents represented by the formulas (10) to (13) into the organic dye, these substituents and amine components (for example, 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 (10): —SO ₂ Cl
Formula (11): -COCl
Equation _{(12): - CH 2 NHCOCH} 2 Cl
Equation (13): - _CH 2 Cl

  For example, when introducing the substituent represented by the formula (10), the organic dye is dissolved in chlorosulfonic acid and reacted with a chlorinating agent such as thionyl chloride. The number of substituents represented by the formula (10) introduced into the organic dye, anthraquinone, or acridone can be controlled by conditions such as time.

  In addition, when introducing the substituent represented by the formula (11), first, an organic dye having a carboxyl group is synthesized by a known method, and then a chlorinating agent such as thionyl chloride is added in an aromatic solvent such as benzene. The method of making it react is mentioned.

  During the reaction between the substituent represented by formula (10) to formula (13) and the amine component, a part of the substituent represented by formula (10) to formula (13) is hydrolyzed, and chlorine is substituted with a hydroxyl group. There are things to do. In that case, the substituent represented by the formula (10) is a sulfonic acid group, and the substituent represented by the formula (11) is a carboxylic acid group. A metal or a salt of the above amine may be formed.

  When the organic dye is an azo dye, a substituent represented by the general formula (7) to the general formula (9) or the following general formula (14) is introduced in advance into the diazo component or the coupling component, and then An azo organic dye derivative can also be produced by performing a coupling reaction.

General formula (14):

X _{1 is, -NH -, - O -,} - CONH -, - SO 2 NH -, - CH 2 NH -, - CH 2 NHCOCH 2 NH- or _-X 2 _{-Y-X 3} - represents, _{X 2 is, -NH -, - O -,} - CONH -, - SO 2 NH -, - CH 2 NH -, - NHCO- or -NHSO ₂ - represents, _{X 3} each independently -NH- or -O- Y 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 substituent represented by any one of the general formulas (2), (3) and the general formula (4).
Q is —O—R ₂ , —NH—R ₂ , a halogen group, —X ₁ —R _1, or a substituent represented by any one of the general formulas (2), (3), or (4) Represents.
R ₂ 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.

  In addition, the triazine derivative having a basic functional group of the present invention uses, for example, cyanuric chloride as a starting material, and at least one chlorine of cyanuric chloride is represented by general formula (7) to general formula (9) or general formula (14). Reaction with an amine component (for example, N, N-dimethylaminopropylamine or N-methylpiperazine) which forms the substituent represented by the following, and then reacting the remaining chlorine of cyanuric chloride with various amines or alcohols Obtained by.

  An organic dye derivative having a basic functional group or a triazine derivative having a basic functional group is considered to exert a dispersion effect when the added derivative acts (for example, adsorbs) on the surface of the carbon material. And it seems that the wetness with respect to the solvent of the carbon material surface is accelerated | stimulated by the polarity of the basic functional group which the said derivative | guide_body which acted on the carbon material surface (for example, adsorption | suction) has, and it becomes easy to solve aggregation of carbon material.

<Base>
The present invention is characterized in that a base is used in combination with an organic dye derivative having a basic functional group or a triazine derivative having a basic functional group. Although the detailed reason is unknown, it has been found that by using a combination of the above derivative and a base, good dispersion stability of the carbon material can be obtained. Examples of the base used at this time include various bases such as metal hydroxides such as alkali metals, salts generated by the reaction between a weak acid and a strong base, ammonia and amines. Of these, amines are preferred because of their solubility in organic solvents.

  The molecular weight is preferably 300 or less, more preferably 200 or less. When the molecular weight is larger than 300, the feature of the present invention that the dispersion resin is not used may not be fully utilized. Further, it was found that a base having a smaller molecular weight tends to reduce the addition amount. At the same time, since the base having a small molecular weight has a small boiling point, there is also an advantage that it can be volatilized when forming a coating film using a dispersion liquid (it does not remain in the coating film and does not adversely affect the film properties). Specific examples include primary amines such as hexylamine, octylamine, laurylamine, secondary amines such as ethylenediamine, tertiary amines such as triethylamine, dimethylaminoethanol, diazabicycloundecene, and the like. It is not limited.

<Organic solvent>
In order to obtain the dispersion stability of the carbon material, it is preferable to use a highly polar solvent.

  As the organic solvent used in the present invention, a polar solvent having a relative dielectric constant of 10 or more is preferably used. The relative dielectric constant is one of the indexes representing the polarity of the solvent, and is described in Asahara et al., “Solvent Handbook” (Kodansha Scientific, 1990). If it is less than 10, the solubility of the organic dye derivative having a basic functional group or the triazine derivative having a basic functional group is remarkably lowered. Specifically, alcohols such as methanol (dielectric constant: 33.1), ethanol (23.8), 2-propanol (18.3), 1-butanol (17.1), and 1,2-ethanediol (38.7), 1,2-propanediol (32.0), 1,3-propanediol (35.0), 1,4-butanediol (31.1), diethylene glycol (31.7), etc. Glycol solvents, acetone (20.7), methyl ethyl ketone (18.5), ketones such as methyl isobutyl ketone (13.1), other N-methylpyrrolidone (32.0), acetonitrile (37.5), N, N-dimethylformamide (36.7), pyridine (12.3), sulfolane (43.3), dimethyl sulfoxide (48.9) and the like are mentioned. If the conditions are satisfied things, there is no particular limitation. These solvents can be used alone or in combination of two or more.

  It was also found that the dispersion stability of the carbon material tends to be affected by the electron donating property of the solvent. Use of a solvent having a large electron donating property is preferable, and an organic solvent having a donor number of 15 Kcal / mol or more is particularly preferable, but a solvent of 25 Kcal / mol or more and 60 Kcal / mol or less is more preferable.

The number of donors is a scale that measures the strength of electron donating properties of various solvents. As a standard acceptor, 10 ⁻³ M SbCl ₅ in dichloroethane is selected, and is a value defined as a reaction molar enthalpy value with a donor. The larger the value, the stronger the electron donating property of the solvent. Also, for some solvents, the donor number is estimated indirectly from the ²³ Na-NMR chemical shift of NaClO _{4 in} the solvent. Regarding the number of donors, V.V. Gutman (translated by Otsuki, Okada), “Donor and Acceptor” (Japan Society of Science Publishing Center, 1983).

  Although depending on the dielectric constant of the solvent, if a solvent having a donor number lower than 15 Kcal / mol is used, a sufficient dispersion stabilization effect may not be obtained. Moreover, it seems that there is no remarkable dispersion | distribution improvement effect even if it uses the solvent in which the donor number exceeded 60 Kcal / mol. Specifically, methanol (number of donors: 19), ethanol (20), acetone (17), N-methylpyrrolidone (27) N, N-dimethylformamide (27), pyridine (33), dimethyl sulfoxide (30) , Ethyl acetate (17), tetrahydrofuran (20), and the like, but are not particularly limited as long as the number of donors satisfies the above conditions.

  In addition, when a binder component or the like is added to the dispersion of the present invention, the solvent is selected in consideration of the solubility of the binder component in addition to the influence of the solvent on the dispersibility.

<Method for producing carbon material dispersion>
The dispersion of the present invention disperses a carbon material in an organic solvent in the presence of an organic dye derivative having a basic functional group or a triazine derivative having a basic functional group and a base having a molecular weight of 300 or less. . The base may be added together with the derivative when the derivative is allowed to act (for example, adsorb) on the carbon material, or may be added after acting (for example, adsorbed). Moreover, you may add when disperse | distributing the carbon material surface-treated beforehand with the said derivative | guide_body mentioned later. In the presence of a base, the viscosity of the dispersion is lowered, and the above-mentioned derivative can be efficiently acted (for example, adsorbed) on the carbon material, and the carbon material can be dispersed while acting (for example, adsorbed). The base is preferably added together with the derivative.

  In this case, an organic dye derivative having a basic functional group or a triazine derivative having a basic functional group and a base are completely or partially dissolved in an organic solvent, and a carbon material is added and mixed in the solution. Then, the derivative is dispersed in the organic solvent while acting (for example, adsorbing) on the carbon material.

  An apparatus for dispersing a carbon material in an organic solvent while acting (for example, adsorbing) an organic dye derivative having a basic functional group or a triazine derivative having a basic functional group on the carbon material includes pigment dispersion, etc. A commonly used disperser 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.

  Next, surface treatment with an organic dye derivative having a basic functional group or a triazine derivative having a basic functional group of a carbon material will be described. Examples of the method for obtaining the carbon material surface-treated with the derivative include a method by a dry treatment and a method by a treatment in a liquid phase.

  First, the dry treatment of an organic dye derivative having a basic functional group or a triazine derivative having a basic functional group and a carbon material will be described.

  In the dry treatment in the present invention, the carbon material is mixed, pulverized, or the like with a carbon material and an organic dye derivative having a basic functional group or a triazine derivative having a basic functional group at room temperature or under heating. The above derivative is allowed to act (for example, adsorb) on the surface. The equipment to be used is not particularly limited. Media type dispersers such as paint conditioner (manufactured by Red Devil), ball mill, attritor, vibration mill, kneader, roller mill, stone mill, planetary mixer, fen Medialess dispersion / kneading machines such as Shell Mixer, Hybridizer (Nara Machinery Co., Ltd.), Mechano Micros (Nara Machinery Co., Ltd.), Mechano Fusion System AMS (Hosokawa Micron Co., Ltd.) can be used. In consideration of contamination and the like, it is preferable to use a medialess dispersion / kneading machine.

  Moreover, you may add an organic solvent in the range by which a processed material does not become a gel form at this time. By improving the wetting or (partly) dissolution of the organic dye derivative having a basic functional group or the triazine derivative having a basic functional group by addition of a solvent and the wetting of the carbon material with the derivative, the carbon material and the above The effect of promoting the interaction (for example, adsorption) of the derivative is expected. The addition amount of the organic solvent in this case is 0.5 to 20% by weight based on the addition amount of the derivative, although it varies depending on the material used. Moreover, you may process by making nitrogen gas etc. flow into a dry processing apparatus as a deoxygenation atmosphere as needed.

  The treatment time can be arbitrarily set depending on the apparatus used and the desired degree of kneading. By performing these treatments, a powdery or lump-like treated product can be obtained. About the obtained processed material, you may further dry and grind | pulverize after that.

  Subsequently, a liquid phase treatment between a carbon material and an organic dye derivative having a basic functional group or a triazine derivative having a basic functional group will be described.

  In the liquid phase treatment in the present invention, an organic dye derivative having a basic functional group or a triazine derivative having a basic functional group is mixed with a carbon material and a solvent, and the derivative is allowed to act (for example, adsorb) on the carbon material. And a step of aggregating the carbon material on which the derivative acts to obtain aggregated particles.

  In the step of allowing an organic dye derivative having a basic functional group or a triazine derivative having a basic functional group to act (for example, adsorb) on a carbon material, the derivative is preferably completely or partially dissolved in a solvent. Moreover, it is preferable to further knead and disperse the mixture of the derivative, the carbon material and the solvent.

  In the step of acting (for example, adsorbing) an organic dye derivative having a basic functional group or a triazine derivative having a basic functional group on a carbon material, examples of the solvent used include alcohols, glycols, cellosolves, amino alcohols. , Amines, ketones, carboxylic acid amides, phosphoric acid amides, sulfoxides, carboxylic acid esters, phosphoric acid esters, ethers, nitriles and the like, and water.

  In addition, as a device for causing an organic dye derivative having a basic functional group or a triazine derivative having a basic functional group to act (for example, adsorption) on a carbon material while mixing and dispersing the carbon material in a solvent, the carbon material dispersion A disperser similar to that used for liquid production can be used. From the viewpoint of processing efficiency and productivity, it is preferable to use a mixer or a media-type disperser.

  As a step of aggregating a carbon material on which an organic dye derivative having a basic functional group or a triazine derivative having a basic functional group has acted in a liquid to obtain aggregated particles, the above-mentioned treated product is heated and / or decompressed. Examples include a method of distilling off the solvent, a method of reducing the solubility or dispersibility of the derivative in the solvent to cause aggregation, a method of increasing the carbon material concentration and depriving the fluidity.

  These aggregates are taken out by filtration or centrifugation. The obtained processed product can be used as it is, but it is preferable to use it after washing, drying and grinding.

  Subsequently, the composition of the carbon material dispersion will be described. The concentration of the carbon material in the dispersion is preferably 1% by weight or more and 50% by weight or less, although it depends on the characteristic values of the carbon material such as the specific surface area and surface functional group amount of the carbon material to be used. Is 5% by weight or more and 35% by weight or less. When the concentration of the carbon material is too low, the production efficiency is deteriorated, and when the concentration of the carbon material is too high, the viscosity of the dispersion liquid is remarkably increased, and the dispersion efficiency and the handleability of the dispersion liquid may be lowered.

  The amount of one or more dispersants selected from organic dye derivatives having basic functional groups or triazine derivatives having basic functional groups is determined by the specific surface area of the carbon material used. Generally, it is 0.5 parts by weight or more and 40 parts by weight or less, preferably 1 part by weight or more and 20 parts by weight or less, more preferably 2 parts by weight or more and 10 parts by weight or less with respect to 100 parts by weight of the carbon material. is there. If the amount of the organic dye derivative having a basic functional group or the triazine derivative having a basic functional group is small, a sufficient dispersion effect cannot be obtained, and even if added excessively, a significant dispersion improvement effect cannot be obtained.

  Moreover, as an addition amount of a base, 0.1-10 equivalent is preferable with respect to the basic functional group amount contained in an organic pigment derivative or a triazine derivative, and 0.2-5 equivalent is further more preferable. If the amount of the base is small, a sufficient dispersion effect cannot be obtained, and even if added excessively, a significant dispersion improvement effect cannot be obtained.

  The dispersed particle diameter of the carbon material is desirably reduced to 0.03 μm or more and 2 μm or less, preferably 0.05 μm or more and 1 μm or less, more preferably 0.05 μm or more and 0.5 μm or less. A composition having a carbon material having a dispersed particle size of less than 0.03 μm may be difficult to produce. In addition, a composition in which the dispersed particle diameter of the carbon material exceeds 2 μm may cause a film defect when applied or may have poor storage stability. The dispersed particle size referred to here is a particle size (D50) that is 50% when the volume ratio of the particles is integrated from the fine particle size distribution in the volume particle size distribution. A particle size distribution meter such as a dynamic light scattering type particle size distribution meter ("Microtrack UPA" manufactured by Nikkiso Co., Ltd.).

<Uses of carbon material dispersion>
The field of application of the carbon material dispersion liquid of the present invention is not particularly limited, but is a field where light-shielding property, conductivity, durability, jetness, etc. are required, such as gravure ink, offset ink, magnetic recording medium back A stable and uniform composition can be provided for coatings, electrostatic toners, ink jets, automobile paints, fiber / plastic forming materials, and battery electrodes. Among these, it is suitably used in the field where high conductivity is required and the field where the resistance (for example, hardness) of the coating is required because of the feature of achieving dispersion stabilization without using a dispersion resin.

  The conductivity between the carbon particles decreases when the dispersion resin covers the surface of the carbon material. Since the carbon material dispersion of the present invention does not use a dispersion resin, it exhibits excellent characteristics in battery electrodes that require electrical conductivity. In particular, it is suitably used for a lithium ion secondary battery having a large resistance of the electrode mixture layer.

  In addition, the resistance (for example, hardness) of the coating film decreases when a large amount of dispersion resin is added. This is because the dispersion resin does not contribute to crosslinking and curing. On the other hand, a fine carbon material is used to form a highly transparent and highly black coating film, but a large amount of dispersion resin is required for dispersion, and the resistance of the coating film decreases. Since the carbon material dispersion of the present invention does not use a dispersion resin, the carbon material dispersion exhibits excellent characteristics for coating display panels and the like that require both high transparency and abrasion resistance.

  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 weight” and “%” represents “% by weight”.

  The carbon materials, organic dye derivatives having basic functional groups or triazine derivatives having basic functional groups, dispersants, bases, acids, organic solvents, active materials, and binders used in Examples and Comparative Examples are shown below.

<Carbon material>
# 30 (manufactured by Mitsubishi Chemical Corporation): furnace black, primary particle size 30 nm, specific surface area 74 m <2> / g.
Monarch 800 (manufactured by Cabot Corporation): furnace black, primary particle diameter 17 nm, specific surface area 210 m 2 / g, hereinafter abbreviated as M800.
Denka black granular product (manufactured by Denki Kagaku Kogyo Co., Ltd.): Acetylene black, primary particle size 35 nm, specific surface area 68 m 2 / g, hereinafter abbreviated as granular product.
EC-300J (manufactured by Akzo): Ketjen black, primary particle size 40 nm, specific surface area 800 m <2> / g.
Carbon nanotube: Multi-walled carbon nanotube, fiber diameter 10-20 nm, fiber length 2-5 μm, hereinafter abbreviated as CNT.
VGCF (manufactured by Showa Denko): carbon nanofiber, fiber diameter 150 nm, fiber length 10-20 μm.

<Derivatives with basic functional groups>
Organic pigment derivatives having basic functional groups: A, B, C, D, E, F, G
Triazine derivatives having basic functional groups: H, I, J, K, L, M, N, O
Tables 1 to 4 show various derivatives A to O having a basic functional group.

<Dispersant>
[Surfactant]
Emulgen A-60 (manufactured by Kao Corporation): nonionic surfactant (polyoxyethylene derivative), hereinafter abbreviated as EmA-60.
Demol N (manufactured by Kao Corporation): an anionic surfactant (β-naphthalenesulfonic acid-formalin condensate sodium salt), hereinafter abbreviated as DemN.

[Dispersion resin]
-ESREC BL-10 (manufactured by Sekisui Chemical Co., Ltd.): Polyvinyl butyral resin, hereinafter abbreviated as BL-10.
Solsperse 20000 (manufactured by Lubrizol): a polymer copolymer containing a basic group, hereinafter abbreviated as SP20000.
Azisper PB-821 (manufactured by Ajinomoto Fine Techno Co.): a basic functional group-containing copolymer, hereinafter abbreviated as PB-821.

<Base>
Laurylamine: molecular weight 185 g / mol, hereinafter abbreviated as LA.
Triethylamine: molecular weight 101 g / mol, hereinafter abbreviated as TEA.
Dimethylaminoethanol: molecular weight 89 g / mol, hereinafter abbreviated as DMAE.

<Acid>
Acetic acid: molecular weight 60 g / mol.

<Organic solvent>
Methanol: relative dielectric constant 33.1, donor number 19.1.
Acetone: dielectric constant 20.7, donor number 17
Pyridine: relative dielectric constant of 13.1, donor number of 33.1.
N-methyl-2-pyrrolidone: relative dielectric constant 32, donor number 27.3, hereinafter abbreviated as NMP.

<Active material>
HLC-22 (Honjo Chemical Co., Ltd.): positive electrode active material lithium cobaltate (LiCoO ₂ ), average particle size 6.6 μm, specific surface area 0.62 m ² / g, hereinafter abbreviated as LCO.
MCMB6-28 (manufactured by Osaka Gas Chemical Co.): active material for negative electrode mesophase carbon (MFC), average particle diameter of 5 to 7 μm, specific surface area of 4 m ² / g, hereinafter abbreviated as MFC.

<Binder>
KF polymer W1100 (manufactured by Kureha): polyvinylidene fluoride (PVDF), hereinafter abbreviated as PVDF.

<Preparation of surface-treated carbon material>
[Surface treated carbon material (1)]
100 parts of M800 and 8 parts of the derivative I shown in Table 3 were charged, dispersed in an attritor for 30 minutes using zirconia beads as a medium, and then separated from the beads to obtain a surface-treated carbon material (1).

[Surface treated carbon material (2)]
100 parts of M800, 8 parts of derivative J shown in Table 3, and 300 parts of methanol were stirred and mixed with a disper for 30 minutes, and then the obtained processed product was filtered and dried to obtain the surface-treated carbon material (2). Obtained.

<Preparation of binder liquid>
9.8 parts of tetraethoxysilane, 8.1 parts of ethyl silicate 40 (Mitsubishi Chemical Corporation), 3.3 parts of vinyltrimethoxysilane, 3.9 parts of water, 3.3 parts of nitric acid, 6.5 parts of methanol, ethanol 58.6 parts and 6.5 parts of isopropyl alcohol (IPA) were stirred and mixed for 3 hours to obtain a binder liquid A.

<Preparation of carbon material dispersion>
The carbon material dispersions obtained in Examples and Comparative Examples were evaluated by measuring the viscosity and the dispersed particle size. The viscosity was measured using a B-type viscometer (“BL” manufactured by Toki Sangyo Co., Ltd.) at 25 ° C. and 60 rpm. The dispersion particle size was measured by measuring the average particle size (D50 value) using a dynamic light scattering particle size distribution meter (“MICROTRACK UPA” manufactured by Nikkiso Co., Ltd.). Methanol was used as a dilution solvent at the time of measurement. The storage stability was evaluated from the change in particle size after the carbon black dispersion was stored at 40 ° C. for 10 days. The degree of dispersion of the carbon nanotube and the carbon nanofiber dispersion was determined by determination with a grind gauge (according to JIS K5600-2-5).

[Examples 1 to 24]
According to the composition shown in Table 5, various organic solvents and derivatives having basic functional groups (any one of derivatives A to O shown in Table 1 to Table 4) and various bases were charged into a glass bottle, mixed and dissolved, and then various carbons. Black was added, and zirconia beads were used as media to disperse with a paint shaker for 2 hours to obtain various carbon black dispersions. All of them had low viscosity, a small dispersed particle size, and good storage stability. In particular, when NMP or pyridine was used as a solvent, dispersion stabilization was possible with a small amount of base.
Examples 7 and 8 are reference examples.

[Example 25, Example 26]
In accordance with the composition shown in Table 5, methanol or NMP and derivative A shown in Table 1 and LA as the base were added to LA and mixed and dissolved. Then, CNT or VGCF was added, and zirconia beads were used as media to disperse in a paint shaker for 2 hours. Various carbon material dispersions were obtained. All of them had a low viscosity and the degree of dispersion evaluated with a 50 μm gauge was 10 μm. Storage stability was also good.

[Example 27, Example 28]
In accordance with the composition shown in Table 6, methanol or NMP and LA are charged into a glass bottle, mixed and dissolved, and then the surface-treated carbon material (1) or (2) is added, and dispersed with a paint shaker for 2 hours using zirconia beads as a medium. Various carbon black dispersions were obtained. All of them had low viscosity, a small dispersed particle size, and good storage stability.

[Comparative Examples 1 to 4]
According to the composition shown in Table 7, methanol or NMP and various carbon blacks were charged into a glass bottle and dispersed for 2 hours using a zirconia bead as a medium with a paint shaker. Carbon black is highly cohesive and difficult to disperse in a solvent alone.

[Comparative Example 5 and Comparative Example 6]
According to the composition shown in Table 7, methanol or NMP and CNT or VGCF were charged into a glass bottle and dispersed with a zirconia bead as a medium for 2 hours using a paint shaker. Many coarse grains of 100 μm or more were observed with a 100 μm gauge.

[Comparative Examples 7 to 9]
In accordance with the composition shown in Table 7, methanol or NMP and derivative A or derivative O having a basic functional group were charged into a glass bottle, mixed and dissolved, then added # 30, and zirconia beads were used as media for 2 hours with a paint shaker Although dispersed, the dispersion was highly viscous and agglomerated. The presence or absence of a base greatly affects the dispersion stability.

[Comparative Examples 10 to 13]
In accordance with the composition shown in Table 7, methanol or NMP and various bases were added to a glass bottle and mixed, then # 30 was added and dispersed for 2 hours with a paint shaker using zirconia beads as a medium. Was. The base alone does not function as a dispersant, and it is considered that the base is used in combination with a derivative having a basic functional group to contribute to dispersion stabilization.

[Comparative Example 14 and Comparative Example 15]
In accordance with the composition shown in Table 8, NMP, a derivative A or O having a basic functional group, and acetic acid were charged into a glass bottle, mixed and dissolved, then added # 30, and dispersed for 2 hours in a paint shaker using zirconia beads as a medium. Various carbon material dispersions were obtained. In all cases, the viscosity and the dispersion particle size were larger than those of the dispersions of Examples. When only electron donating NMP is used as a solvent, it is considered that the effect of stabilizing the dispersion is greater when the derivative and the base are used in combination than when the derivative and the acid are used in combination.

[Comparative Examples 16 to 23]
In accordance with the composition shown in Table 9, methanol or NMP and various dispersants are charged into a glass bottle, mixed and dissolved, then various carbon blacks are added, and dispersed in a paint shaker for 2 hours using zirconia beads as a medium. Various carbon black dispersions Got. In all cases, the viscosity and the dispersion particle size were larger than those of the dispersions of Examples.

[Comparative Example 24, Comparative Example 25]
In accordance with the composition shown in Table 9, methanol or NMP and SP20000 or PB-821 were charged into a glass bottle, mixed and dissolved, then added with CNT or VGCF, dispersed in a paint shaker for 2 hours using zirconia beads as media, and various carbon materials A dispersion was obtained. Both had higher viscosities than the dispersions of the examples, and the dispersities evaluated with a 50 μm gauge were 20 μm and 25 μm, respectively. Moreover, it was a tendency of aggregation over time.

[Comparative Example 26 to Comparative Example 28]
In accordance with the composition shown in Table 10, methanol or NMP and SP20000 or PB-821 were charged into a glass bottle, mixed and dissolved, then various carbon blacks were added, and dispersed in a paint shaker for 2 hours using zirconia beads as a medium. A dispersion was obtained. In order to obtain a degree of dispersion equivalent to that of the example, a dispersant was required 3 times or more.

[Comparative Example 29, Comparative Example 30]
In accordance with the composition shown in Table 10, methanol or NMP and SP20000 or PB-821 were charged in a glass bottle, mixed and dissolved, then added with CNT or VGCF, dispersed with a zirconia bead for 2 hours in a paint shaker, and various carbon materials A dispersion was obtained. In order to obtain the same degree of dispersion as in the examples, a dispersing agent of 4 times or more was necessary.

  From Tables 5 to 10, the dispersions of the examples had a low viscosity, a small dispersion particle size, and good storage stability compared to the dispersions of the comparative examples. Moreover, it turns out that the component used for dispersion | distribution needs only a small amount.

<Preparation of battery electrode composite>
Evaluation of the battery electrode composites obtained in Examples and Comparative Examples was performed on a PET film using a doctor blade and then dried, and was performed based on the surface resistance and appearance of the coating film. Loresta-GP (manufactured by Mitsubishi Chemical Analytech Co., Ltd.) was used for measuring the surface resistance (according to JISK 7149). The appearance of the coating film was visually evaluated as ◯: no problem, Δ: spotted pattern, x: coarse graining.

[Example 29 to Example 31, Comparative Example 31 to Comparative Example 36]
According to the composition shown in Table 11, LCO or MFC, various dispersions prepared in Examples or Comparative Examples, and PVDF and binder were mixed with a disper to obtain various battery electrode composites. The evaluation results are shown in Table 11.

  From Table 11, the battery electrode composites of Examples 29 to 31 using the dispersion liquid of the present invention were coated in comparison with Comparative Examples 31 to 33 using a dispersion liquid of only a carbon material and a solvent. It can be seen that the surface resistance and appearance of the coating film are excellent, and the surface resistance of the coating film is superior to that of a comparative example using a general dispersant.

<Assembly of lithium ion secondary battery positive electrode evaluation cell>
[Example 32, Example 33, Comparative Example 37 to Comparative Example 40]
The previously prepared battery electrode mixture (Example 29, Example 30, Comparative Example 31, Comparative Example 32, Comparative Example 34, and Comparative Example 35) was placed on a 20 μm-thick aluminum foil serving as a current collector. After coating using a blade, the coating was dried at 120 ° C. under reduced pressure, and then rolled with a roller press to prepare a positive electrode mixture layer having a thickness of 100 μm. This is a punching working electrode with a diameter of 9 mm, a metallic lithium foil (thickness 0.15 mm) as a counter electrode, and a separator made of a porous polypropylene film (# 2400 manufactured by Celgard) is inserted and laminated between the working electrode and the counter electrode, An electrolyte solution (non-aqueous electrolyte solution in which LiPF ₆ is dissolved at a concentration of 1 M in a mixed solvent of ethylene carbonate and diethyl carbonate in a ratio of 1: 1) is filled, and a bipolar electrode type metal cell (HS flat cell manufactured by Hosensha) ) Was assembled. The cell was assembled in a glove box substituted with argon gas.

<Assembly of lithium ion secondary battery negative electrode evaluation cell>
[Example 34, Comparative Example 41, Comparative Example 42]
The previously prepared battery electrode mixture (Example 31, Comparative Example 33, Comparative Example 36) was applied onto a 20 μm thick aluminum foil serving as a current collector using a doctor blade, and then subjected to 120 ° C. under reduced pressure. After being heated and dried at, a rolling process was performed with a roller press to produce a negative electrode mixture layer having a thickness of 100 μm. This is a punching working electrode with a diameter of 9 mm, a metallic lithium foil (thickness 0.15 mm) as a counter electrode, and a separator made of a porous polypropylene film (# 2400 manufactured by Celgard) is inserted and laminated between the working electrode and the counter electrode, An electrolyte solution (non-aqueous electrolyte solution in which LiPF ₆ is dissolved at a concentration of 1 M in a mixed solvent of ethylene carbonate and diethyl carbonate in a ratio of 1: 1) is filled, and a bipolar electrode type metal cell (HS flat cell manufactured by Hosensha) ) Was assembled. The cell was assembled in a glove box substituted with argon gas.

<Characteristic evaluation of lithium ion secondary battery positive electrode>
The produced battery evaluation cell was fully charged at a constant current and constant voltage charge (upper limit voltage 4.2 V) at a room temperature (25 ° C.) with a charge rate of 0.2 C and 1.0 C, and at a constant current at the same rate as during charging. Charge / discharge for discharging to a discharge lower limit voltage of 3.0V is defined as one cycle (charge / discharge interval rest time 30 minutes), and this cycle is performed for a total of 20 cycles to evaluate charge / discharge cycle characteristics (Evaluation apparatus: SM-8 manufactured by Hokuto Denko Co., Ltd. ) Moreover, the cell after evaluation was decomposed | disassembled, the external appearance of the electrode coating film was confirmed visually, and it was set as x when it was confirmed that the composite material has partially peeled from the electrical power collector. The evaluation results are shown in Table 12.

  From Table 12, Example 32 and Example 33 using the electrode of the present invention showed better results in battery capacity and 20 cycle capacity retention rate than the comparative example. In Comparative Examples 37 and 38, the composite material was peeled off from the current collector after evaluation.

<Evaluation of lithium ion secondary battery negative electrode characteristics>
The produced battery evaluation cell was fully charged at a constant current and constant voltage charge (upper limit voltage 0.5 V) at a room temperature (25 ° C.) and at a charge rate of 0.2 C and 1.0 C, and at a constant current at the same rate as during charging. Charging / discharging for discharging until the voltage reaches 1.5 V is defined as one cycle (charging / discharging interval rest time 30 minutes), and this cycle is performed for a total of 20 cycles to evaluate charging / discharging cycle characteristics (Evaluation apparatus: SM-8 manufactured by Hokuto Denko) ) Moreover, the cell after evaluation was decomposed | disassembled, the presence or absence of the electrode coating film defect was confirmed visually, and it was set as x when it was confirmed that the composite material has partially peeled from the electrical power collector. The evaluation results are shown in Table 13.

  From Table 13, in Example 34 using the electrode of the present invention, better results were obtained in battery capacity and 20 cycle capacity maintenance ratio than in the comparative example. In Comparative Example 41, the composite material was peeled off from the current collector after the evaluation.

<Preparation of display coating composition>
The evaluation of the composition for display coating obtained in Examples and Comparative Examples was performed by spin-coating on a glass substrate, pre-drying at 70 ° C. for 5 minutes, and baking at 200 ° C. for 15 minutes. It was performed according to appearance and hardness. The transparency was measured using a haze meter (Nippon Denshoku Co., Ltd., COH-300A). The appearance of the coating film was visually evaluated as ◯: no problem, Δ: spotted pattern, x: coarse graining. The hardness was measured by a pencil hardness test (according to JIS K5600-5-4).

[Example 35, Example 36, Comparative Example 43 to Comparative Example 48]
In accordance with the composition shown in Table 14, the binder liquid A prepared earlier and the various dispersions prepared in Examples or Comparative Examples were mixed at a ratio of carbon material: other solid content = 4: 6, and then ethanol. : IPA = 85: 15 was diluted to a solid content concentration of 0.4% to obtain various display coating compositions. The evaluation results are shown in Table 14.

  From Table 14, the display coating compositions of Example 35 and Example 36 using the dispersion of the present invention are Comparative Example 43, Comparative Example 44, and General using a dispersion of only a carbon material and a solvent. It can be seen that the coating film is superior in transparency and appearance as compared with Comparative Examples 45 and 46 using a dispersant. Moreover, although the comparative example 47 and comparative example 48 which used many common dispersing agents improved transparency, the spot pattern which seems to originate in compatibility with a binder liquid, and the fall of pencil hardness were confirmed. .

Claims (7)

A carbon material dispersion liquid comprising an organic dye derivative having a basic functional group or a triazine derivative having a basic functional group, a base having a molecular weight of 300 or less, a carbon material, and an organic solvent,
The organic dye derivative having a basic functional group is an organic dye derivative represented by the following general formula (6),
The amount of the derivative added is 1 part by weight or more and 20 parts by weight or less with respect to 100 parts by weight of the carbon material,
The amount of the base added is 0.1 to 10 equivalents relative to the derivative,
A carbon material dispersion, wherein the carbon material is at least one carbon material selected from the group consisting of neutral carbon black, carbon nanotubes, and carbon nanofibers.

General formula (6):

Z is at least one selected from the group represented by the following general formula (7), (8) or general formula (9). n represents an integer of 1 to 4.

General formula (7):
General formula (8):
General formula (9):

X ₄ is a direct _{bond, -SO 2 -, - CO -} , - CH 2 NHCOCH 2 -, - CH 2 NHCONHCH 2 -, - CH 2 - or, -X ₅ -Y-X ₆ - represents a. X ₅ is -NH- or represents -O-, X ₆ represents a direct _{bond, -SO 2 -, - CO -} , - CH 2 NHCOCH 2 -, - CH 2 NHCONHCH 2 - or -CH ₂ - Represents. Y 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, having 1 to 20 carbon atoms.
v represents an integer of 1 to 10.
R ₃ and R ₄ are each independently a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkenyl group, an optionally substituted aryl group, or R ₃ and R ₄ together. Represents an optionally substituted heterocyclic residue containing additional nitrogen, oxygen or sulfur atoms.
R ₅ , R ₆ , R ₇ and R ₈ each independently represents a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkenyl group or an optionally substituted aryl group.
R ₉ represents an optionally substituted alkyl group, an optionally substituted alkenyl group, or an optionally substituted aryl group.
R ₁₂ represents an organic dye residue.
The organic dye residue represented by R ₁₂ is diketopyrrolopyrrole dye, azo, disazo, polyazo azo dye, phthalocyanine dye, diaminodianthraquinone, anthrapyrimidine, flavantron, anthanthrone, indanthrone, pyranthrone. These are residues of anthraquinone dyes and quinacridone dyes of violanthrone.
  The dispersion according to claim 1, wherein the base is an amine.   The dispersion according to claim 1 or 2, wherein the relative permittivity of the organic solvent is 10 or more.   The dispersion liquid according to claim 1, wherein the organic solvent has a donor number of 15 Kcal / mol or more.   The battery electrode in which the electrode compound-material layer was formed using the dispersion liquid in any one of Claims 1-4.   A lithium ion 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 containing lithium, wherein the positive electrode and the negative electrode are at least A lithium ion secondary battery, one of which is the battery electrode according to claim 5.   The composition for display coatings adjusted using the dispersion liquid in any one of Claims 1-4.