JP2005206657A - Conductive composition, its preparation method, conductive paint, capacitor and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a conductive composition which can form a solid electrolytic layer which is excellent in conductivity and heat resistance through simple steps such as application and drying, its preparation method and a conductive paint. <P>SOLUTION: The conductive composition comprises a conductive mixture comprising a cyano-containing polymer compound and a π-conjugated conductive polymer and a conductive filler. In the preparation method of the conductive composition, the conductive mixture is prepared by polymerizing a precursor monomer of the π-conjugated conductive polymer in the presence of the cyano-containing polymer compound, and the conductive filler is mixed into the conductive mixture. The conductive paint comprises the conductive composition and water or an organic solvent. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an electroconductive composition that can be used as an antistatic agent, an electromagnetic wave shielding material, a cathode material for a functional capacitor, and the like, a method for producing the same, and an electroconductive coating material. Furthermore, it is related with a capacitor | condenser and its manufacturing method.

In recent years, with the digitization of electronic equipment, capacitors used for this have been required to reduce the impedance in the high frequency region. In order to meet this requirement, for example, an anode made of a porous body of valve metal such as aluminum, tantalum, or niobium, a dielectric layer made of an oxide film of the valve metal, a solid electrolyte layer, a carbon layer, and a silver layer. A so-called functional capacitor having a laminated cathode has been used (for example, see Patent Document 1).
As the solid electrolyte layer of this functional capacitor, a π-conjugated conductive polymer such as pyrrole or thiophene is used. The role of the π-conjugated conductive polymer is to penetrate into the porous body and contact the dielectric layer with a larger area to increase the capacity. The purpose is to prevent leakage due to leakage current from a defect portion of the dielectric layer by repairing with a polymer.
Since the solid electrolyte layer has higher performance when the equivalent series resistance (ESR) is lower, high conductivity is required to achieve low ESR. Furthermore, since the use environment of a capacitor | condenser is severe, what has high heat resistance is calculated | required.

As a method for forming a solid electrolyte layer containing a π-conjugated conductive polymer on a dielectric layer, electrolytic polymerization or chemical polymerization is employed.
In the electropolymerization as disclosed in Patent Document 2, after forming a conductive layer made of manganese oxide on the surface of the valve metal porous body, it is necessary to perform electropolymerization of a conductive polymer using the conductive layer as an electrode. However, the electropolymerization of the conductive polymer layer after the formation of the conductive layer is very complicated and the effect of using a highly conductive conductive polymer because manganese oxide has low conductivity. Had faded.

 In addition, in the chemical polymerization disclosed in Patent Document 3, the monomer is polymerized on the dielectric layer, but the production time of the capacitor is greatly reduced because the polymerization time is long. In addition, since the oxidant cannot be sufficiently washed, the surface of the dielectric layer is eroded by the oxidant, and the leakage current characteristic is lowered or the moisture resistance is lowered.

 Further, in Patent Documents 2 and 3, electrolytic polymerization and chemical polymerization are performed in the capacitor manufacturing process, and there is a problem that the process is complicated. Therefore, as described in Patent Document 4, aniline is polymerized in the presence of a polymer electrolyte having a sulfo group, a carboxyl group or the like to obtain a water-soluble polyaniline, and the aqueous solution is applied and dried. Attempts have been made to simplify the process. However, since the solvent is water, the surface tension is large, the permeability into the porous body is inferior, and the conductivity is low because it is not a single conductive polymer. Furthermore, since the obtained solid electrolyte layer contains a polymer electrolyte, the conductivity may be dependent on humidity.

Further, in order to increase the conductivity of the solid electrolyte layer, for example, as shown in Patent Document 5, it has been attempted to produce by controlling the polymerization conditions in chemical polymerization at a high level. Usually, complicated processes are often complicated, which has been an obstacle to simplification of the process and cost reduction.
JP 2003-37024 A JP-A-63-158829 JP 63-173313 A JP-A-7-105718 Japanese Patent Laid-Open No. 11-74157

 It is an object of the present invention to provide a conductive composition capable of forming a solid electrolyte layer excellent in conductivity and heat resistance, a method for producing the same, and a conductive paint by simple steps such as coating and drying. Furthermore, it aims at providing the capacitor | condenser using the said electroconductive composition, and its manufacturing method.

The present invention is shown in the following (1) to (10).
(1) A conductive composition comprising a conductive mixture composed of a cyano group-containing polymer compound and a π-conjugated conductive polymer, and a conductive filler.
(2) The conductive composition according to (1), wherein the surface of the conductive filler is covered with a π-conjugated conductive polymer.
(3) The conductive composition according to (1) or (2), further comprising a dopant.
(4) The conductive composition according to any one of (1) to (3), wherein the conductive filler has a sulfo group and / or a carboxyl group on the surface.
(5) The conductivity according to any one of (1) to (4), wherein the mass ratio of the cyano group-containing polymer compound to the π-conjugated conductive polymer is 5:95 to 99: 1. Sex composition.
(6) The conductive composition according to any one of (1) to (5), wherein the mass ratio of the conductive mixture to the conductive filler is 50:50 to 99.9: 0.1 .
(7) A π-conjugated conductive polymer precursor monomer is polymerized in the presence of a cyano group-containing polymer compound to produce a conductive mixture, and a conductive filler is mixed with the conductive mixture. A method for producing a conductive composition.
(8) A conductive paint comprising the conductive composition according to any one of (1) to (6) and water or an organic solvent.
(9) From an anode made of a porous body of valve metal, a dielectric layer made of an oxide film of the valve metal adjacent to the anode, and the conductive composition according to any one of (1) to (6) And a cathode.
(10) A dielectric layer made of an oxide film of the valve metal is formed on the anode made of a porous body of the valve metal, and the conductive paint according to (8) is applied on the dielectric layer and dried. A method for producing a capacitor, comprising forming a cathode made of a conductive composition on a surface of a dielectric layer.

With the conductive composition of the present invention, the production method thereof, and the conductive paint, the solid electrolyte layer can be formed by a simple process such as coating and drying. Further, the obtained solid electrolyte layer has high conductivity and heat resistance.
The capacitor of the present invention has excellent performance and can withstand harsh usage environments.
In the capacitor manufacturing method of the present invention, the capacitor manufacturing process is simplified.

First, the conductive composition of the present invention will be described.
The conductive composition of the present invention comprises a conductive mixture comprising a cyano group-containing polymer compound and a π-conjugated conductive polymer, and a conductive filler.

[Cyano group-containing polymer compound]
The cyano group-containing polymer compound constituting the conductive mixture is a polymer compound having a cyano group in the molecule. For example, polyacrylonitrile resin, polymethacrylonitrile resin, acrylonitrile-styrene resin, acrylonitrile-butadiene resin , Acrylonitrile-butadiene-styrene resin, and resins obtained by cyanoethylation of a hydroxyl group or amino group-containing resin, such as cyanoethyl cellulose.
Such a cyano group-containing polymer compound has a function of dissolving a π-conjugated conductive polymer in water or an organic solvent (hereinafter, water and organic solvents may be collectively referred to as a solvent).

 The cyano group-containing polymer compound may be a copolymer, for example, a copolymer in which one or more polymers having a sulfo group having a dopant action are copolymerized with the above-described cyano group-containing polymer compound having a cyano group. It may be a polymer. Examples of the polymer having a sulfo group include polyvinyl sulfonic acid resin, polystyrene sulfonic acid resin, polyallyl sulfonic acid resin, polyacryl sulfonic acid resin, polymethacryl sulfonic acid resin, and poly-2-acrylamido-2-methylpropane sulfonic acid resin. And polyisoprene sulfonic acid resin.

 The cyano group-containing polymer compound may be copolymerized with other vinyl compounds. Examples of the other vinyl compound include polymerizable vinyl compounds such as styrene, butadiene, acrylic acid, methacrylic acid, hydroxyacrylic acid, hydroxymethacrylic acid, acrylic acid ester, methacrylic acid ester, and p-vinyltoluene. By copolymerizing these polymerizable vinyl compounds, the solvent solubility can be controlled.

 The cyano group-containing polymer compound may contain a synthetic rubber component for improving impact resistance, an anti-aging agent, an antioxidant, and an ultraviolet absorber for improving environmental resistance. However, the amine compound as an antioxidant may inhibit the action of the oxidant used when polymerizing the π-conjugated conductive polymer. Therefore, an amine-based antioxidant is added using a phenol-based antioxidant. It is preferable to avoid or mix after polymerization.

[Π-conjugated conductive polymer]
Examples of the π-conjugated conductive polymer include substituted or unsubstituted polyaniline, substituted or unsubstituted polypyrrole, substituted or unsubstituted polythiophene, and one or two (co) polymers selected from these. It is done. Among them, polypyrrole, polythiophene, poly N-methylpyrrole, poly-3-methylthiophene, poly-3-methoxythiophene, and one or two (co) polymers selected from these are resistance, cost, and reactivity. Are preferably used.
In particular, alkyl-substituted compounds such as poly N-methylpyrrole and poly-3-methylthiophene are more preferable because of the effect of improving solvent solubility. Among alkyl groups, a methyl group is preferred because it does not adversely affect conductivity.

[Conductive filler]
Examples of the conductive filler include carbon particles having a particle size of 5 to 5000 nm, graphite particles, metal particles such as copper, nickel, silver, gold, tin, and iron, fiber lengths of 0.1 to 500 μm, and wire diameters of 1 to 1000 nm. Examples thereof include carbon fibers and carbon nanotubes. Among these, carbon fibers and carbon nanotubes that can improve conductivity with a small amount of addition and are excellent in dispersibility are preferable.
Carbon materials such as carbon particles, graphite particles, carbon fibers, and carbon nanotubes are preferable in that they have a reducing action and have a function of preventing deterioration of the π-conjugated conductive polymer due to oxygen.

 The conductive filler preferably has a sulfo group and / or a carboxyl group on its surface. If the surface of the conductive filler has a sulfo group and / or a carboxyl group, the dispersibility in the π-conjugated conductive polymer is improved, and it can be used as a dopant to the π-conjugated conductive polymer. Since it works, the heat resistance of the dopant can be increased. As a method for introducing a sulfo group and / or a carboxyl group into the surface of the conductive filler, for example, a known surface treatment such as a method of treating the conductive filler with concentrated sulfuric acid or peroxide can be employed.

The surface of the conductive filler is preferably covered with a π-conjugated conductive polymer. If the surface of the conductive filler is covered with a π-conjugated conductive polymer, the conductive filler directly touches the dielectric layer when a solid electrolyte film made of a conductive composition is formed on the dielectric layer. Therefore, the function of repairing the dielectric layer by the π-conjugated conductive polymer can be surely activated.
As a method of covering the surface of the conductive filler with the π-conjugated conductive polymer, a so-called chemical polymerization method is simple. In the coating by the chemical polymerization method, first, a precursor monomer of a π-conjugated system conductive polymer and a dopant if necessary are added to a solvent in which a conductive filler is dispersed, and the mixture is prepared by sufficiently stirring and mixing. To do. Then, after dropping the oxidizing agent into the mixed solution to advance the polymerization, the conductive filler whose surface is covered with the π-conjugated conductive polymer by removing and purifying the oxidizing agent, residual monomer and by-products Get.

Alternatively, the conductive filler may be treated with a solution obtained by dissolving a conductive mixture composed of a cyano group-containing polymer compound and a π-conjugated conductive polymer in a solvent, and the surface may be covered with the π-conjugated conductive polymer. . In this case, the cyano group-containing polymer compound used for the treatment is preferably a compound having a polarity different from that of the cyano group-containing polymer compound separately added to obtain a conductive composition. In this way, dissolution during the dispersion process can be prevented.
Even when the conductive filler surface is covered with a π-conjugated conductive polymer, if a conductive filler having a sulfo group or a carboxyl group on the surface is used, the sulfo group or the carboxyl group works as a strong dopant. A conductive π-conjugated conductive polymer film can be formed.

[Dopant]
The conductive composition preferably contains a dopant in order to improve both conductivity and heat resistance. Usually, halogen compounds, Lewis acids, proton acids, and the like are used as dopants. Specifically, organic acids such as organic carboxylic acids and organic sulfonic acids, organic cyano compounds, fullerenes, hydrogenated fullerenes, fullerene hydroxides, carboxyls Examples include fullerene oxide and sulfonated fullerene.

Furthermore, as organic acids, alkylbenzene sulfonic acid, alkyl naphthalene sulfonic acid, alkyl naphthalene disulfonic acid, naphthalene sulfonic acid formalin polycondensate, melamine sulfonic acid formalin polycondensate, naphthalene disulfonic acid, naphthalene trisulfonic acid, dinaphthylmethane disulfone Examples include acids, anthraquinone sulfonic acids, anthraquinone disulfonic acids, anthracene sulfonic acids, and pyrene sulfonic acids, and the metal salts thereof can also be used.
Examples of the organic cyano compound include dichlorodicyanobenzoquinone (DDQ), tetracyanoquinodimethane, and tetracyanoazanaphthalene.

In this conductive composition, the mass ratio of the cyano group-containing polymer compound to the π-conjugated conductive polymer (cyano group-containing polymer compound: π-conjugated conductive polymer) is 5:95 to 99: 1. It is preferably 10:90 to 95: 5, more preferably 20:80 to 85:15. Within this range, both conductivity and solvent solubility are high. However, if the π-conjugated conductive polymer is less than this range, sufficient conductivity may not be obtained. It tends to be scarce.
The mass ratio of the conductive mixture to the conductive filler (conductive mixture: conductive filler) is preferably 50:50 to 99.9: 0.1, and preferably 60:40 to 95: 5. Is more preferable, and 70:30 to 90:10 is particularly preferable. If it is in this range, both conductivity and film-forming property are high, but if the conductive filler is less than this range, the conductivity may not be sufficiently improved, and if it is more than this, film-forming property is lacking, When expensive carbon nanotubes are used, the cost may increase. In addition, when the conductive composition is used as a capacitor cathode material, if there is too much conductive filler, a short circuit may occur due to the leakage current of the capacitor dielectric, and the capacitor may not function.

 The conductive composition described above contains a cyano group-containing polymer compound, and since this cyano group-containing polymer compound has a property of solubilizing the π-conjugated conductive polymer in a solvent, It becomes possible to form a solid electrolyte layer by applying a π-conjugated conductive polymer. In addition, since the conductive composition contains a conductive filler, not only the conductivity of the solid electrolyte layer formed from the conductive composition is increased, but the conductive filler is inorganic particles. The heat resistance of the solid electrolyte layer is increased.

[Method for producing conductive composition]
In the method for producing a conductive composition of the present invention, a precursor mixture of a π-conjugated conductive polymer is polymerized in the presence of a cyano group-containing polymer compound to produce a conductive mixture, and the conductive mixture is electrically conductive. This is a method of mixing a functional filler.
An example of the manufacturing method is shown below. First, a cyano group-containing polymer compound is dissolved in a solvent that can dissolve the cyano group-containing polymer compound, and a precursor monomer of a π-conjugated conductive polymer is added to the solution, followed by thorough mixing to prepare a monomer-containing solution. Next, after an oxidant is dropped into the monomer-containing solution to advance the polymerization, the oxidant, residual monomer, and by-products are removed and purified to obtain a cyano group-containing polymer compound and a π-conjugated conductive polymer. A conductive mixture is obtained. And an electroconductive filler is added to this electroconductive mixture, and it fully mixes, stirs, and disperses, and obtains an electroconductive composition.

 As the oxidizing agent for polymerizing the precursor monomer of the π-conjugated conductive polymer, known ones can be used, for example, metal halogen compounds such as ferric chloride, boron trifluoride, aluminum chloride, hydrogen peroxide, Examples thereof include peroxides such as benzoyl peroxide, persulfates such as potassium persulfate, sodium persulfate, and ammonium persulfate, ozone, and oxygen.

 The solvent for dissolving the cyano group-containing polymer compound is not particularly limited. For example, water, methanol, ethanol, propylene carbonate, N-methylpyrrolidone, dimethylformamide, dimethylacetamide, cyclohexanone, acetone, methyl ethyl ketone, methyl isobutyl ketone, toluene And the like may be dissolved alone or in a mixed solvent. Among these, an organic solvent other than water has low surface tension and high permeability into the porous body, so that the conductivity becomes higher.

In the said manufacturing method, a dopant may be added with the precursor monomer of (pi) conjugated system conductive polymer, and may be added to a conductive mixture.
The mixing of the conductive filler into the conductive mixture is not limited to the direct addition to the conductive mixture. For example, the conductive filler is added to the monomer-containing solution and the conductive polymer is polymerized. There is no particular problem even if it is mixed with the conductive mixture.

 In the method for producing a conductive composition described above, since the cyano group-containing polymer compound coexists when the precursor monomer of the π-conjugated conductive polymer is polymerized, the π-conjugated conductive polymer is used as a solvent. Can be dissolved. Therefore, it becomes possible to apply a π-conjugated conductive polymer, and the solid electrolyte layer can be formed on the surface of the dielectric layer by a simple process such as application and drying. And since the leakage current from a dielectric defect | deletion part can be prevented with a solid electrolyte layer, and since the conductive filler with high heat resistance is mixed, the electroconductivity and heat resistance of a solid electrolyte layer can be improved.

[Conductive paint]
The conductive paint of the present invention contains the above-described conductive composition and water or an organic solvent. As an organic solvent, things other than water are mentioned among the solvents which melt | dissolve the cyano group containing high molecular compound mentioned above.
The conductive paint may be produced by adding the conductive composition to water or an organic solvent, or the conductive composition containing the solvent obtained by the above-described method for producing a conductive composition is used as it is. May be.

[Capacitor]
The capacitor of the present invention has an anode made of a porous body of valve metal, a dielectric layer made of an oxide film of the valve metal adjacent to the anode, and a cathode made of the conductive composition. Since the cathode of this capacitor is formed from the above conductive composition, the capacitor has excellent performance and can withstand harsh usage environments.
Here, examples of the valve metal include aluminum, tantalum, niobium, titanium, hafnium, zirconium, zinc, tungsten, bismuth, and antimony. Among these, aluminum, tantalum, and niobium are suitable for use in the capacitor anode. is there.

An example of the method for manufacturing a capacitor of the present invention will be described. In this example of the capacitor manufacturing method, first, a dielectric layer made of an oxide film of the valve metal is formed on an anode made of a porous body of the valve metal to obtain a capacitor intermediate. Here, as a method of manufacturing the capacitor intermediate, for example, after etching the aluminum foil to increase the surface area, the surface is oxidized, or the surface of the sintered body of tantalum particles and niobium particles is oxidized and pellets The method of making it.
Next, a conductive paint is applied to the capacitor intermediate by a method such as dipping or spray coating, and then the solvent is dried to form a cathode made of a conductive composition on the surface of the dielectric layer to obtain a capacitor.
When applying the conductive paint by the immersion method, for example, the capacitor intermediate is immersed in the conductive paint and penetrates into the porous body, and if necessary, ultrasonic waves, vibration, reduced pressure, heating, etc. An operation may be added to assist penetration into the porous body. Further, the coating thickness may be adjusted by repeatedly dipping and drying.

  In the method for manufacturing a capacitor according to the present invention, the cathode is formed by applying and drying the conductive paint on the dielectric layer, so that the capacitor manufacturing process is simplified.

Hereinafter, the present invention will be described in more detail with reference to examples.
(Example 1)
(1) Synthesis of cyano group-containing polymer compound 50 g of acrylonitrile and 10 g of styrene were dissolved in 500 ml of toluene, 1.5 g of azobisisobutyronitrile was added as a polymerization initiator, and polymerized at 50 ° C. for 5 hours. And the polymer produced | generated by superposition | polymerization was wash | cleaned with methanol, and the cyano group containing high molecular compound was obtained.
(2) Production of conductive composition 10 g of the cyano group-containing polymer synthesized in (1) was dissolved in 90 g of acetonitrile, 50 g of pyrrole and 20 g of sodium octadecylnaphthalenesulfonate were added, and the mixture was cooled to -20 ° C. A monomer-containing solution was prepared by stirring for 1 hour.
To this monomer-containing solution, an oxidant solution in which 250 g of ferric chloride was dissolved in 1250 ml of acetonitrile was added dropwise over 2 hours while maintaining −20 ° C., and stirring was further continued for 12 hours to polymerize pyrrole.
After completion of the polymerization, 2000 ml of methanol was added to the reaction solution to precipitate the product, and the generated precipitate was filtered, and then washed with methanol and pure water until the filtrate became transparent to remove the conductive mixture. Obtained. This conductive mixture was dissolved in dimethylacetamide (DMAc) to prepare a conductive mixture solution having a concentration of 5% by mass. And 10 mass parts carbon nanotube was mixed with respect to 100 mass parts of solid content of this electroconductive mixture solution, it stirred, and the electroconductive coating material containing an electroconductive composition and dimethylacetamide was obtained.

The obtained conductive paint was evaluated for electrical conductivity (conductivity) and heat resistance by the following test methods. The results are shown in Table 1.
<Test method>
(A) Electric conductivity The electric conductivity (unit: S / cm) of a coating film formed by applying a conductive paint on a PET film with a thickness of 2 μm is measured using a conductivity meter (trade name: Loresta MCP-T600). (In the table, “initial” column).
(B) Heat resistance A conductive paint was applied to a PET film with a thickness of 10 μm and then left in an oven at 125 ° C. for 240 hours, and the change in electrical conductivity after leaving for 240 hours was used as an index of heat resistance.

(Example 2)
(1) Synthesis of cyano group-containing polymer compound 30 g of acrylonitrile and 20 g of methyl methacrylate are dissolved in 500 ml of toluene, 1.5 g of azobisisobutyronitrile is added as a polymerization initiator, and polymerization is carried out at 50 ° C. for 5 hours. did. And the polymer produced | generated by superposition | polymerization was wash | cleaned with methanol, and the cyano group containing high molecular compound was obtained.
(2) Production of conductive composition 10 g of the cyano group-containing polymer compound synthesized in (1) is dissolved in 90 g of acetonitrile, 50 g of pyrrole and 20 g of sodium anthraquinone disulfonate are added, and the mixture is cooled to −20 ° C. A monomer-containing solution was prepared by stirring for a period of time.
To this monomer-containing solution, an oxidant solution in which 250 g of ferric chloride was dissolved in 1250 ml of acetonitrile was added dropwise over 2 hours while maintaining −20 ° C., and stirring was further continued for 12 hours to polymerize pyrrole.
After completion of the polymerization, 2000 ml of methanol was added to the reaction solution to precipitate the product, and the generated precipitate was filtered, and then washed with methanol and pure water until the filtrate became transparent to remove the conductive mixture. Obtained. This conductive mixture was dissolved in dimethylacetamide (DMAc) to prepare a conductive mixture solution having a concentration of 5% by mass. And 15 mass parts sulfo group containing carbon nanotube was mixed with respect to 100 mass parts of solid content of this electroconductive mixture solution, and it stirred, and obtained the electroconductive coating material containing an electroconductive composition and dimethylacetamide. Here, as the sulfo group-containing carbon nanotube, 100 g of carbon nanotube was added to 1000 ml of concentrated sulfuric acid, refluxed at 100 ° C. for 12 hours, washed with water, and filtered.
The obtained conductive paint was tested in the same manner as in Example 1.

(Example 3)
(1) Production of surface-coated conductive filler In 100 ml of acetonitrile, 10 g of the sulfo group-containing carbon nanotubes used in Example 2 were dispersed, and subsequently, 5 g of pyrrole and 1 g of p-toluenesulfonic acid were added, and −20 The mixture was stirred for 1 hour while cooling to ° C. Next, an oxidant solution in which 15 g of ferric chloride was dissolved in 100 ml of acetonitrile was dropped into this solution over 2 hours while maintaining -20 ° C., and stirring was further continued for 12 hours to polymerize pyrrole. By this polymerization, a surface-coated conductive filler in which the surface of the sulfo group-containing carbon nanotube was coated with pyrrole was obtained.
The obtained surface-coated conductive filler was filtered off and washed with methanol and pure water until the filtrate became transparent to obtain a high-purity surface-coated conductive filler.
(2) Synthesis of cyano group-containing polymer compound 30 g of acrylonitrile and 20 g of methyl methacrylate are dissolved in 500 ml of toluene, 1.5 g of azobisisobutyronitrile is added as a polymerization initiator, and polymerization is carried out at 50 ° C. for 5 hours. did. And the polymer produced | generated by superposition | polymerization was wash | cleaned with methanol, and the cyano group containing high molecular compound was obtained.

(3) Production of conductive composition 10 g of the cyano group-containing polymer compound synthesized in (2) was dissolved in 90 g of acetonitrile, 50 g of pyrrole and 20 g of sodium anthraquinone disulfonate were added, and the mixture was cooled to −20 ° C. A monomer-containing solution was prepared by stirring for a period of time.
To this monomer-containing solution, an oxidant solution in which 250 g of ferric chloride was dissolved in 1250 ml of acetonitrile was added dropwise over 2 hours while maintaining −20 ° C., and stirring was further continued for 12 hours to polymerize pyrrole.
After completion of the polymerization, 2000 ml of methanol was added to the reaction solution to precipitate the product, and the generated precipitate was filtered, and then washed with methanol and pure water until the filtrate became transparent to remove the conductive mixture. Obtained. This conductive mixture was dissolved in dimethylacetamide (DMAc) to prepare a conductive mixture solution having a concentration of 5% by mass. Then, 15 parts by mass of the surface-coated carbon nanotube obtained in (1) is mixed with 100 parts by mass of the solid content of the conductive mixture solution, and the mixture is stirred to obtain a conductive composition containing the conductive composition and dimethylacetamide. A paint was obtained.
The obtained conductive paint was tested in the same manner as in Example 1.

(Comparative Example 1)
In 100 g of pure water, 10 g of sodium polystyrene sulfonate having a molecular weight of 50000 was dissolved, followed by addition of 10 g of aniline and stirring for 1 hour while cooling to 5 ° C. to prepare a monomer-containing solution.
To this monomer-containing solution, an oxidant solution in which 250 g of ammonium persulfate was dissolved in 1250 ml of pure water was added dropwise over 2 hours while maintaining 5 ° C., and stirring was further continued for 12 hours to polymerize aniline.
After the completion of the polymerization, the solution containing the polymerization product was passed through a column filled with an ion exchange resin several times and washed to obtain a liquid containing a conductive composition. And the electrically conductive composition density | concentration of the liquid was adjusted to 5 mass%, and it was set as the electrically conductive coating material.
The obtained conductive paint was tested in the same manner as in Example 1.

Since the conductive paints of Examples 1 to 3 contained a cyano group-containing polymer compound, a π-conjugated conductive polymer, and a conductive filler, they had high conductivity and had sufficient heat resistance. .
On the other hand, since the conductive paint of Comparative Example 1 was obtained by dissolving a π-conjugated conductive polymer in water using a polymer electrolyte, it was not only low in conductivity but also inferior in heat resistance.

  The conductive composition of the present invention can be suitably used as a cathode material for functional capacitors such as aluminum electrolytic capacitors, tantalum electrolytic capacitors, niobium electrolytic capacitors, as well as antistatic coatings such as antistatic coatings and antistatic packaging materials. It can be used for electrophotographic equipment parts such as materials, electromagnetic wave shielding materials for shielding electromagnetic waves on liquid crystal screens and plasma display screens, transfer belts, developing rolls, charging rolls, and transfer rolls.

Claims (10)

  A conductive composition comprising a conductive mixture composed of a cyano group-containing polymer compound and a π-conjugated conductive polymer, and a conductive filler.   The conductive composition according to claim 1, wherein the surface of the conductive filler is covered with a π-conjugated conductive polymer.   Furthermore, a dopant is included, The electrically conductive composition of Claim 1 or 2 characterized by the above-mentioned.   The conductive composition according to claim 1, wherein the conductive filler has a sulfo group and / or a carboxyl group on the surface.   The conductive composition according to claim 1, wherein the mass ratio of the cyano group-containing polymer compound and the π-conjugated conductive polymer is 5:95 to 99: 1.   The conductive composition according to claim 1, wherein a mass ratio of the conductive mixture to the conductive filler is 50:50 to 99.9: 0.1.   Conductivity characterized in that a conductive mixture is produced by polymerizing a precursor monomer of a π-conjugated conductive polymer in the presence of a cyano group-containing polymer compound, and a conductive filler is mixed into the conductive mixture. A method for producing the composition.   A conductive paint comprising the conductive composition according to claim 1 and water or an organic solvent.   An anode made of a porous body of valve metal, a dielectric layer made of an oxide film of the valve metal adjacent to the anode, and a cathode made of the conductive composition according to claim 1. Capacitor characterized by that.   A dielectric layer made of an oxide film of the valve metal is formed on an anode made of a porous body of the valve metal, and the conductive paint according to claim 8 is applied on the dielectric layer and dried to form a dielectric layer. A method for producing a capacitor, comprising forming a cathode made of a conductive composition on a surface.