JP5575041B2 - Conductive polymer suspension and method for producing the same, conductive organic material, and electrolytic capacitor and method for producing the same - Google Patents

Description

  Embodiments according to the present invention relate to a conductive polymer suspension and a manufacturing method thereof, a conductive organic material obtained from the suspension, an electrolytic capacitor using the same, and a manufacturing method thereof.

  Conductive organic materials are used for electrodes for capacitors, electrodes for dye-sensitized solar cells, electrodes for electroluminescence displays, and the like. As such conductive organic materials, polymer materials obtained by increasing the molecular weight of pyrrole, thiophene, 3,4-ethylenedioxythiophene, aniline, etc. are known, and related techniques are disclosed in Patent Documents 1 to 3. ing.

  Patent Document 1 relates to a solution (dispersion) of polythiophene, a production method thereof, and the use of a salt for antistatic treatment of a plastic molded body. Specifically, polythiophene dispersions consisting of 3,4-dialkoxythiophene structural units in the presence of polyanions are described. It is described that this polythiophene dispersion is produced by oxidative polymerization of 3,4-dialkoxythiophene at a temperature of 0 to 100 ° C. in the presence of a polyacid.

  Patent Document 2 discloses an aqueous dispersion of a complex of poly (3,4-dialkoxythiophene) and a polyanion, a method for producing the same, a coating composition containing the aqueous dispersion, and the composition applied. The present invention relates to a coated substrate having a transparent conductive film. Specifically, poly (3,4-dialkoxythiophene produced by polymerizing 3,4-dialkoxythiophene in an aqueous solvent using peroxodisulfuric acid as an oxidizing agent in the presence of a polyanion. ) And polyanions in aqueous dispersions are described.

  Patent Document 3 relates to a water-based antistatic coating composition. Specifically, (a) a conductive polymer comprising a polythiophene in the form of a cation composed of repeating structural units of 3,4-dialkoxythiophene and a polyanion, and (b) an amide bond or a hydroxyl group in the molecule. A water-based antistatic coating composition containing a water-soluble compound that is liquid at room temperature and (c) an aqueous dispersion of a self-emulsifying polyester resin is described. In this water-based antistatic coating composition, the (b) water-soluble compound is contained in the range of 40 to 6000 parts by weight with respect to 100 parts by weight of the (a) conductive polymer, and (c) A water dispersion of a self-emulsifying polyester resin is formed from an aromatic carboxylic acid and a diol, and 5 to 5 mol% of 5-sulfoisophthalic acid is contained in the aromatic dicarboxylic acid, and the (c) The self-emulsifying type polyester resin aqueous dispersion is contained in the range of 20 to 5000 parts by weight as a solid content with respect to 100 parts by weight of the conductive polymer (a).

JP 07-090060 A JP 2004-059666 A JP 2002-060736 A

  However, in the method of oxidative chemical polymerization of 3,4-dialkoxythiophene in the presence of a polyanion acting as a dopant, it is difficult to control the doping rate, and it does not contribute to the undoped polyanion, that is, conductivity. Excessive polyanions will be present. Therefore, the methods described in Patent Documents 1 and 2 are hardly sufficient as a method for producing a polymer material having high conductivity.

In addition, the surface resistivity of antistatic materials is generally classified as 10 ⁵ to 10 ¹⁴ Ω / □, and if the conductivity is too high (less than 10 ⁵ Ω / □), it may cause severe electrostatic discharge. Therefore, it is considered that the charged object does not have conductivity enough to dissipate the static electricity quickly. Even when the conductivity is sufficient as an antistatic material, for example, when used as an electrode of a capacitor, it is difficult to sufficiently satisfy the requirement for low ESR from the viewpoint of conductivity. In addition, since conductive polymer materials containing excessive polyanions have very poor water resistance, capacitors using such conductive organic materials as electrolytes are reliable, especially in high humidity atmospheres. There is a disadvantage that the characteristics are inferior.

  In the method of Patent Document 3, the self-emulsification type polyester resin aqueous dispersion improves the adhesion to the substrate and the water resistance of the coating film. However, since an insulating resin is added, the conductivity of the film is increased. There is a problem that decreases. In addition, even if the electrical conductivity is sufficient as an antistatic material, when this water-based antistatic coating composition is used, for example, as an electrode of a capacitor, the electrical conductivity is low, and the capacitor is required to have low ESR. It is difficult to satisfy. Further, the self-emulsifying type resin has a problem that it is easily segregated in the composition for antistatic coating as compared with a completely dissolving type resin.

  An object of an embodiment according to the present invention is to solve the above-described problem, and is a conductive polymer for providing an organic material having excellent adhesion to a substrate and liquid resistance and having high conductivity. An object of the present invention is to provide a suspension solution and a method for manufacturing the same, and to provide an electrolytic capacitor and a method for manufacturing the same that have low ESR and reliability, particularly excellent characteristics in a high humidity atmosphere.

Embodiments according to the present invention include a conductive polymer, at least one water-soluble polyhydric alcohol, oxalic acid, acetylenedicarboxylic acid, malonic acid, succinic acid, fumaric acid, malic acid, oxaloacetic acid, glutaric acid, At least one water-soluble organic substance selected from the group consisting of oxoglutaric acid, adipic acid, citric acid, oxalosuccinic acid, ortho-phthalic acid, hemimellitic acid, trimesic acid, merophanic acid, benzenepentacarboxylic acid and melittic acid ; A conductive polymer suspension solution comprising the water-soluble polyhydric alcohol and at least one organic polymer resin other than the water-soluble organic substance .

In an embodiment according to the present invention, a monomer containing a conductive polymer is chemically oxidatively polymerized using an oxidizing agent in a solvent containing an organic acid or a salt thereof as a dopant, and a mixture containing the conductive polymer is obtained. A first step of obtaining, a second step of recovering the conductive polymer from the mixture, a third step of causing an oxidizing agent to act on the conductive polymer in an aqueous solvent containing a polyacid, At least one water-soluble polyhydric alcohol and oxalic acid, acetylenedicarboxylic acid, malonic acid, succinic acid, fumaric acid, malic acid, oxaloacetic acid, glutaric acid, oxoglutaric acid, adipic acid, citric acid, oxalosuccinic acid, ortho - phthalic acid, hemimellitic acid, trimesic acid, and at least one water-soluble organic material selected from the group consisting of mellophanic acid, benzene penta carboxylic acid, and mellitic acid Is the manufacturing method of the conductive polymer suspension, characterized in that it comprises a fourth step of mixing at least one kind of the water-soluble polyhydric alcohol and said water-soluble organic substance other than the organic polymer resin .

  An embodiment according to the present invention is a conductive polymer suspension solution obtained by the above method.

  An embodiment according to the present invention is a conductive organic material, wherein the conductive polymer suspension is dried to remove the solvent.

  An embodiment according to the present invention is an electrolytic capacitor having the above-described conductive polymer suspension solution or an electrolyte layer containing the above-described conductive organic material.

  Embodiments according to the present invention include a step of forming a dielectric layer on the surface of an anode conductor made of a valve metal, and applying or impregnating the conductive polymer suspension solution on the dielectric layer to form an electrolyte. And a step of forming a layer.

  According to the embodiment of the present invention, a conductive polymer suspension solution for providing an organic material having excellent adhesion to a substrate and liquid resistance and high conductivity can be obtained. Further, according to the embodiment of the present invention, an electrolytic capacitor having low ESR and reliability, particularly excellent characteristics in a high humidity atmosphere can be obtained.

2 is an X-ray diffraction chart of conductive polymer films obtained in Example 1 and Comparative Example 2. FIG. It is typical sectional drawing which shows the structure of the solid electrolytic capacitor which concerns on this embodiment.

  Hereinafter, the conductive polymer suspension and the manufacturing method thereof according to the present embodiment, the conductive organic material obtained from the suspension, the electrolytic capacitor using the same, and the manufacturing method thereof will be described in detail.

<Conductive polymer suspension>
The conductive polymer suspension according to this embodiment is a water-soluble solution having a conductive polymer, at least one water-soluble polyhydric alcohol, and two or more functional groups capable of polycondensation with the water-soluble polyhydric alcohol. And at least one kind of organic material. In this conductive polymer suspension solution, the water-soluble polyhydric alcohol and the water-soluble organic substance are completely dissolved in the solution, and both can be subjected to a condensation polymerization reaction during the drying process. In the conductive organic material obtained by drying, a water-insoluble resin is present without uneven distribution, and the effect makes the conductive organic material excellent in adhesion to the substrate and liquid resistance.

  Examples of the conductive polymer contained in the conductive polymer suspension include polypyrrole, polythiophene, polyaniline, and derivatives thereof. Among these, poly (3,4-ethylenedioxythiophene) having a structural unit represented by the following formula (1) or a derivative thereof is preferable. The conductive polymer may be a homopolymer, a copolymer, one type, or two or more types.

  The content of the conductive polymer in the conductive polymer suspension solution is preferably 0.1 to 30 parts by mass, more preferably 0.5 to 20 parts by mass with respect to 100 parts by mass of the solvent. . Water is preferred as the solvent for the conductive polymer suspension.

  The water-soluble polyhydric alcohol contained in the conductive polymer suspension is an alcohol having two or more OH groups. The term “water-soluble” as used herein means that the compound is completely dissolved in a solution containing water as a main solvent. One type of water-soluble polyhydric alcohol may be used, or two or more types may be used.

  Examples of water-soluble polyhydric alcohols include ethylene glycol, butylene glycol, propylene glycol, 3-methyl-1,3-butanediol, hexylene glycol, diethylene glycol, dipropylene glycol, glycerin, diglycerin, inositol, xylose, glucose, mannitol. Trehalose, erythritol, xylitol, sorbitol, pentaerythritol, polyethylene glycol, polypropylene glycol, polyvinyl alcohol and the like are preferable, but erythritol or pentaerythritol is more preferable. Erythritol or pentaerythritol interacts with the undoped polyacid anion (resistive component) that exists in the vicinity of the conductive polymer particles in the conductive polymer suspension solution. In addition to lowering the resistance and increasing the density of the conductive polymer, higher conductivity can be achieved.

  The water-soluble polyhydric alcohol is preferably trivalent or higher. A resin obtained by polycondensation of a water-soluble polyhydric alcohol having a valence of 3 or more and a water-soluble organic substance having at least two functional groups capable of polycondensation has a cross-linked structure. Low liquid absorption and excellent liquid resistance. From this viewpoint, erythritol or pentaerythritol is more preferable.

  Since erythritol has higher crystallinity than, for example, sorbitol or maltose, it has low hygroscopicity and is easy to handle. In addition, erythritol is known as a food additive used as a sweetener, is excellent in safety and stability, and has a solubility in water several times higher than that of, for example, ethylene glycol or glycerin. There is an advantage that the degree of freedom in designing the addition amount is high.

  Pentaerythritol has a characteristic that it gradually sublimes when heated, and dehydrates and polymerizes when heated above its melting point. This has the advantage that the physical properties of the organic material change and the density and strength are improved. Such a reaction is caused by the chemical structure, and is unlikely to occur in a chemical structure such as erythritol or sorbitol.

  The content of the water-soluble polyhydric alcohol in the conductive polymer suspension solution is 100 parts by mass or more, preferably 200 parts by mass or more with respect to 100 parts by mass of the conductive polymer, and a high effect is achieved. The upper limit of the content of the water-soluble polyhydric alcohol is not particularly limited as long as it is an amount that can be dissolved in a solvent, but is preferably 3000 parts by mass or less.

  The water-soluble organic substance contained in the conductive polymer suspension solution is a water-soluble organic substance other than the water-soluble polyhydric alcohol, and has two or more functional groups capable of polycondensation with the water-soluble polyhydric alcohol. As the functional group, an epoxy group, a hydroxyl group, and a carboxyl group are preferable, and a carboxyl group is particularly preferable from the viewpoint of stability in a conductive polymer suspension solution and reactivity with a water-soluble polyhydric alcohol. The term “water-soluble” as used herein means that the compound is completely dissolved in a solution containing water as a main solvent. One type of water-soluble organic substance may be used, or two or more types may be used.

  Examples of water-soluble organic substances having two or more epoxy groups include sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, diglycerol polyglycidyl ether, glycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether, and polypropylene glycol diglycidyl ether. It is done. The “polyglycidyl ether” means that H in at least two OH groups is substituted with a glycidyl group, and the upper limit of the number of substituted glycidyl groups is the OH group of the compound before substitution. Is the number of A water-soluble organic substance having two or more water-soluble polyhydric alcohols and epoxy groups becomes a polyether resin by a condensation polymerization reaction.

  Examples of water-soluble organic substances having two or more carboxyl groups include oxalic acid, acetylenedicarboxylic acid, malonic acid, succinic acid, fumaric acid, malic acid, oxaloacetic acid, glutaric acid, oxoglutaric acid, adipic acid, citric acid, oxalosuccinic acid Ortho-phthalic acid, hemimellitic acid, trimesic acid, merophanic acid, benzenepentacarboxylic acid, melittic acid and the like. Ortho-phthalic acid is preferred from the viewpoint of stability in aqueous solution and reactivity with water-soluble polyhydric alcohol. A water-soluble polyhydric alcohol and a water-soluble organic substance having two or more carboxyl groups are subjected to condensation polymerization to become a polyester resin.

  The content of the water-soluble organic substance in the conductive polymer suspension solution is preferably 1 to 200 parts by mass with respect to 100 parts by mass of the conductive polymer, and contains 50 to 100 parts by mass of the water-soluble organic substance. Is more preferable.

  The conductive polymer suspension solution preferably further contains a polyacid. Examples of the polyacid include polycarboxylic acids such as polyacrylic acid, polymethacrylic acid, and polymaleic acid; polysulfonic acids such as polyvinyl sulfonic acid and polystyrene sulfonic acid; and copolymers having these structural units. Among these, polystyrene sulfonic acid having a structural unit represented by the following formula (2) is preferable. One or more polyacids may be used.

  The weight average molecular weight of the polyacid is preferably 2,000 to 500,000, and more preferably 10,000 to 200,000.

  The content of the polyacid in the conductive polymer suspension is preferably 20 to 3,000 parts by mass and more preferably 30 to 1,000 parts by mass with respect to 100 parts by mass of the conductive polymer. preferable.

  The conductive polymer suspension solution preferably further contains at least one organic polymer resin. The water-soluble polyhydric alcohol and the water-soluble organic substance dissolved in the solution contain a water-insoluble resin obtained by a condensation polymerization reaction in the drying process, and an organic polymer resin, so that A wide variety of resin structures with mixed chain structures can be obtained. Therefore, a conductive organic material with further improved adhesion to the substrate and liquid resistance can be obtained. Moreover, since the organic polymer resin is included, a conductive organic material having liquid resistance can be obtained before the condensation reaction between the water-soluble polyhydric alcohol and the water-soluble organic substance and before the end point of the condensation reaction.

  The organic polymer resin is an organic polymer resin other than the conductive polymer, but preferably contains a phthalate ester. Examples of the organic polymer resin include polystyrene, polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyvinyl alcohol, polymethyl methacrylate, polyamide, polyimide, polyamideimide, polyester, polyether, polyethylene terephthalate, Polyethylene glycol phthalate, polycarbonate, polyphenylene oxide, polyurethane, polyacetal, diallyl phthalate, polyacrylate, polymethacrylate, polyacrylonitrile, polytetrafluoroethylene, polybutadiene, polyisoprene, polysiloxane, polycarbonate, cellulose, methylcellulose, ethylcellulose, fluorine Resin, urea resin, silicon resin, phenol resin, melamine resin, Epoxy resins, acrylic resins, alkyd resins, butyral resins, silicone resins, polylactic acid, a compound containing a phthalic acid ester structure such as poly glycol phthalate diols, and the like. In particular, the organic polymer resin is preferably a compound represented by the following formula (3). In the following formula (3), n is 2 or more, preferably 10 or more, and more preferably 50 or more.

  The mixing amount of the organic polymer resin is preferably in the range of 0.1 to 10 parts by mass, and 0.1 to 3 parts by mass with respect to 100 parts by mass of the conductive polymer in the conductive polymer suspension solution. More preferred is the range of parts.

<Method for producing conductive polymer suspension solution>
The manufacturing method of the conductive polymer suspension according to the present embodiment includes the following steps.

[First step]
In the present embodiment, first, a monomer containing a conductive polymer is chemically oxidatively polymerized using an oxidizing agent in a solvent containing an organic acid or a salt thereof as a dopant to obtain a mixture containing the conductive polymer. . In the first step, a conductive polymer having a high degree of polymerization and a high degree of crystallization can be obtained.

  Examples of the dopant include alkyl sulfonic acid, benzene sulfonic acid, naphthalene sulfonic acid, anthraquinone sulfonic acid, camphor sulfonic acid and derivatives thereof, and salts thereof such as iron (III). These sulfonic acids may be monosulfonic acid, disulfonic acid or trisulfonic acid. Examples of alkylsulfonic acid derivatives include 2-acrylamido-2-methylpropanesulfonic acid. Examples of benzenesulfonic acid derivatives include phenolsulfonic acid, styrenesulfonic acid, toluenesulfonic acid, and dodecylbenzenesulfonic acid. Examples of naphthalene sulfonic acid derivatives include 1-naphthalene sulfonic acid, 2-naphthalene sulfonic acid, 1,3-naphthalene disulfonic acid, 1,3,6-naphthalene trisulfonic acid, and 6-ethyl-1-naphthalene sulfonic acid. It is done. Examples of the derivatives of anthraquinone sulfonic acid include anthraquinone-1-sulfonic acid, anthraquinone-2-sulfonic acid, anthraquinone-2,6-disulfonic acid, and 2-methylanthraquinone-6-sulfonic acid. Among these, 1-naphthalenesulfonic acid, 2-naphthalenesulfonic acid, 1,3,6-naphthalenetrisulfonic acid, anthraquinone disulfonic acid, p-toluenesulfonic acid, camphorsulfonic acid or iron (III) salts thereof are preferable. Camphorsulfonic acid is more preferable because it has a great influence on the high crystallization of the polymer. Camphorsulfonic acid may be an optically active substance. 1 type may be sufficient as a dopant and 2 or more types may be sufficient as it.

  The amount of the dopant used is not particularly limited because it can be removed in the second step even if it is excessive, but 1 to 100 parts by weight is preferable with respect to 1 part by weight of the monomer, and 1 to 50 parts by weight. Is more preferable.

  The solvent may be water, an organic solvent, or a water-miscible organic solvent, preferably a solvent having good compatibility with the monomer, and particularly preferably a solvent having good compatibility with the dopant and the oxidizing agent. Examples of the organic solvent include alcohol solvents such as methanol, ethanol and propanol; and low polar solvents such as acetonitrile and acetone. The organic solvent may be one type or two or more types. Of these, ethanol or a mixed solvent of ethanol and water is preferable.

  The monomer that provides the conductive polymer may be selected according to the target conductive polymer, but is preferably a monomer selected from pyrrole, thiophene, aniline, and derivatives thereof. The monomer may be one type or two or more types.

  Polypyrrole and its derivatives are obtained by polymerizing the corresponding pyrrole or a derivative of pyrrole. As derivatives of pyrrole, 3-alkyl pyrrole such as 3-hexyl pyrrole, 3,4-dialkyl pyrrole such as 3,4-dihexyl pyrrole, 3-alkoxy pyrrole such as 3-methoxy pyrrole, 3,4-dimethoxy pyrrole, etc. 3,4-dimethoxypyrrole.

  Polythiophene and derivatives thereof are obtained by polymerizing the corresponding thiophene or a derivative of thiophene. Examples of thiophene derivatives include 3,4-ethylenedioxythiophene and derivatives thereof, 3-alkylthiophenes such as 3-hexylthiophene, and 3-alkoxythiophenes such as 3-methoxythiophene. Examples of 3,4-ethylenedioxythiophene derivatives include 3,4- (1-alkyl) ethylenedioxythiophene such as 3,4- (1-hexyl) ethylenedioxythiophene.

  Polyaniline and derivatives thereof are obtained by polymerizing a corresponding aniline or a derivative of aniline. Examples of aniline derivatives include 2-alkylanilines such as 2-methylaniline and 2-alkoxyanilines such as 2-methoxyaniline.

  Among these, 3,4-ethylenedioxythiophene represented by the following formula (4) or a derivative thereof is preferable as the monomer.

  The concentration of the monomer in the solvent is preferably from 0.1 to 50% by mass, and more preferably from 0.5 to 30% by mass.

  The oxidizing agent is not particularly limited, and iron (III) chloride hexahydrate, anhydrous iron (III) chloride, iron (III) nitrate nonahydrate, anhydrous ferric nitrate, iron (III) sulfate n water Japanese (n = 3-12), iron (III) sulfate dodecahydrate, iron (III) perchlorate n hydrate (n = 1, 6), iron (III) tetrafluoroborate, etc. Iron (III) salts of inorganic acids of copper; copper (II) salts of inorganic acids such as copper (II) chloride, copper (II) sulfate, copper (II) tetrafluoroborate; nitrosonium tetrafluoroborate; ammonium persulfate Persulfates such as sodium persulfate and potassium persulfate; periodates such as potassium periodate; hydrogen peroxide, ozone, potassium hexacyanoferrate (III), tetraammonium cerium sulfate (IV) dihydrate , Bromine, iodine; p-toluenesulfo Iron (III) salts of organic acids, iron (III), or the like can be used. Among these, inorganic acid or organic acid iron salt (III) or persulfate is preferable, ammonium persulfate or iron p-toluenesulfonate (III) is more preferable, and p has the property of serving as a dopant. -More preferred is iron (III) toluenesulfonate. 1 type may be sufficient as an oxidizing agent, and 2 or more types may be sufficient as it.

  The amount of the oxidizing agent used is not particularly limited because it can be removed in the second step even if it is excessive, but in order to obtain a high conductivity polymer by reacting in a milder oxidizing atmosphere, 0.5-100 mass parts is preferable with respect to 1 mass part of monomers, and 1-50 mass parts is more preferable.

  The reaction temperature of chemical oxidative polymerization is not particularly limited, but is generally around the reflux temperature of the solvent used, preferably 0 to 100 ° C, more preferably 10 to 50 ° C. If the reaction temperature is not appropriate, the conductivity may be impaired. The reaction time of the chemical oxidative polymerization depends on the kind and amount of the oxidant, the reaction temperature, the stirring conditions, etc., but is preferably about 5 to 100 hours.

  The first step is preferably performed in the presence of a substance having a surface active action. As the substance having a surface active action, an anionic surfactant, a cationic surfactant, and an amphoteric surfactant can be used, and dodecylbenzenesulfonic acid, polyethylene glycol and the like are preferable.

[Second step]
In this embodiment, the conductive polymer is recovered from the mixture obtained in the first step. Specifically, by separating and washing the conductive polymer from the reaction liquid containing the conductive polymer obtained by chemical oxidative polymerization, dopants, unreacted monomers, residual metal ions and anions derived from the oxidizing agent Remove. By the second step, sufficient purification treatment is possible, and a highly pure conductive polymer can be obtained.

  Examples of the method for separating the conductive polymer from the reaction solution include a filtration method and a centrifugal separation method.

  The washing solvent is preferably performed using a solvent capable of dissolving the monomer and / or the oxidizing agent without dissolving the conductive polymer. Examples of the cleaning solvent include water and alcohol solvents such as methanol, ethanol, and propanol. The cleaning solvent may be one type or two or more types. The degree of washing can be confirmed by performing pH measurement and colorimetric observation of the washing solvent after washing.

  Furthermore, since the metal component derived from the oxidizing agent can be removed to a higher degree, it is preferable to wash the conductive polymer and / or heat-treat the conductive polymer. The temperature of the heat treatment is not particularly limited as long as it is equal to or lower than the decomposition temperature of the conductive polymer, but is preferably performed at less than 300 ° C. In addition, performing an ion exchange treatment using an ion exchange resin is also effective as a method for removing metal ions and anions derived from an oxidizing agent.

  Impurities contained in the conductive polymer can be quantified by ICP emission analysis or ion chromatography.

[Third step]
In this embodiment, an oxidizing agent is allowed to act on the conductive polymer recovered in the second step in an aqueous solvent containing a polyacid. In the third step, a conductive polymer suspension having good dispersibility of the conductive polymer is obtained by allowing the polyacid and the oxidant as the dispersant to act on the conductive polymer. As a dispersion mechanism, at least the doping action of polyanions derived from polyacids can be considered.

  As the polyacid, the above-mentioned polyacid can be used. Of these, polystyrene sulfonic acid is preferable. The weight average molecular weight of the polyacid is preferably 2,000 to 500,000, and more preferably 10,000 to 200,000.

  The amount of the polyacid used is preferably 20 to 3,000 parts by mass and more preferably 30 to 1,000 parts by mass with respect to 100 parts by mass of the conductive polymer obtained in the second step. preferable.

  As the oxidizing agent, the same oxidizing agent used in the first step can be used, and among them, ammonium persulfate or hydrogen peroxide is preferable.

  10-500 mass parts is preferable with respect to 100 mass parts of conductive polymers obtained at the 2nd process, and, as for the usage-amount of an oxidizing agent, 50-300 mass parts is more preferable.

  As the aqueous solvent, water is preferable, but there is no problem even if a water-soluble organic solvent is added.

  Although the reaction temperature in a 3rd process is not specifically limited, 0-100 degreeC is preferable and 10-50 degreeC is more preferable. The reaction time is not particularly limited, but is about 5 to 100 hours. Moreover, it is preferable to perform the ion exchange process mentioned above after a 3rd process.

[Fourth step]
In this embodiment, during or after the third step, at least one water-soluble polyhydric alcohol and at least one water-soluble organic substance having two or more functional groups capable of polycondensation with the water-soluble polyhydric alcohol are mixed. To do. The water-soluble polyhydric alcohol and water-soluble organic substance mixed in the fourth step undergo a condensation polymerization reaction in the drying process, so that a water-insoluble resin exists in the conductive organic material without uneven distribution, and the effect Thus, a conductive organic material having excellent adhesion to the substrate and liquid resistance is obtained.

  As the water-soluble polyhydric alcohol, those described above can be used. In particular, the conductivity is improved by mixing erythritol or pentaerythritol as the water-soluble polyhydric alcohol. That is, erythritol or pentaerythritol interacts with the undoped dopant anion (resistance component) introduced in the third step, present in the vicinity of the conductive polymer particles in the conductive polymer suspension solution, While lowering the resistance between the conductive polymer particles and increasing the density of the conductive polymer, it is possible to further increase the conductivity.

  Further, by using a water-soluble polyhydric alcohol having a valence of 3 or more as the water-soluble polyhydric alcohol, a resin having a crosslinked structure can be obtained by a condensation polymerization reaction with a water-soluble organic substance. Excellent. From this viewpoint, erythritol or pentaerythritol is preferable.

  By mixing the water-soluble polyhydric alcohol in an amount of 100 parts by mass or more, preferably 200 parts by mass or more with respect to 100 parts by mass of the conductive polymer, a high effect can be obtained. The upper limit of the content of the water-soluble polyhydric alcohol is not particularly limited as long as it is an amount that can be dissolved in water as a solvent, but is preferably 3000 parts by mass or less.

  As the water-soluble organic material, those described above can be used, but a water-soluble organic material having two or more carboxyl groups is preferable. In particular, by mixing ortho-phthalic acid as a water-soluble organic substance, a resin can be formed without segregation in a conductive organic material by condensation polymerization with a water-soluble polyhydric alcohol in the drying process, and adhesion to a substrate and resistance A conductive organic material having excellent liquidity can be obtained.

  The mixing amount of the water-soluble organic substance is preferably 1 to 200 parts by mass and more preferably 50 to 100 parts by mass with respect to 100 parts by mass of the conductive polymer.

<Conductive organic material>
The conductive organic material according to the present embodiment is obtained by drying the above-described conductive polymer suspension solution and removing the solvent. The conductive organic material is excellent in adhesion to a substrate and liquid resistance, and has high conductivity. It is. The drying temperature for removing the solvent is not particularly limited as long as it is equal to or lower than the decomposition temperature of the conductive polymer, but is preferably 300 ° C. or lower.

  Before drying the conductive polymer suspension solution, the water-soluble polyhydric alcohol contained in the conductive polymer suspension solution and the water-soluble organic substance contained in the conductive polymer suspension solution are mixed at 70 to 105 ° C. It is preferable to carry out the polycondensation reaction at this temperature. The temperature is more preferably 80 to 100 ° C. In the conductive organic material obtained by drying, the water-insoluble resin obtained by the polycondensation reaction will be present without being unevenly distributed. It becomes an excellent conductive organic material.

<Electrolytic capacitor and manufacturing method thereof>
The electrolytic capacitor according to the present embodiment has an electrolyte layer containing the above-mentioned conductive polymer suspension or conductive organic material. The electrolyte layer is preferably solid. In the electrolytic capacitor according to the present embodiment, since the material forming the electrolyte has high conductivity, the electrolytic capacitor has a low ESR. In addition, the high crystallinity of the polymer material has a high oxygen barrier property, and due to the effects of the crosslinked resin, it has excellent adhesion to the substrate and liquid resistance, so the reliability of the electrolytic capacitor Is also expected to improve.

  FIG. 2 is a schematic cross-sectional view showing the structure of the solid electrolytic capacitor according to this embodiment. This electric field capacitor has a structure in which a dielectric layer 2, a solid electrolyte layer 3, and a cathode conductor 4 are formed in this order on an anode conductor 1.

  The anode conductor 1 is formed of a valve metal plate, foil, or wire; a sintered body made of fine particles of the valve metal; a porous metal that has been subjected to surface expansion treatment by etching. Examples of the valve action metal include tantalum, aluminum, titanium, niobium, zirconium, and alloys thereof. Among these, at least one valve action metal selected from aluminum, tantalum and niobium is preferable.

  The dielectric layer 2 is a layer that can be formed by electrolytic oxidation of the surface of the anode conductor 1, and is also formed in pores such as a sintered body and a porous body. The thickness of the dielectric layer 2 can be adjusted as appropriate by the voltage of electrolytic oxidation.

  The solid electrolyte layer 3 contains the conductive polymer suspension or the conductive organic material. The solid polymer electrolyte layer 3 may have a single layer structure or a multilayer structure. In the solid electrolytic capacitor shown in FIG. 2, the solid polymer electrolyte layer 3 is composed of a first conductive polymer compound layer 3A and a second conductive polymer compound layer 3B. The first conductive polymer contained in the first conductive polymer compound layer 3A and the second conductive polymer contained in the second conductive polymer compound layer 3B are the same type of polymer. Preferably there is.

  The solid electrolyte layer 3 further comprises a conductive polymer obtained by polymerizing pyrrole, thiophene, aniline or a derivative thereof; an oxide derivative such as manganese dioxide or ruthenium oxide; TCNQ (7,7,8,8-tetracyano) An organic semiconductor such as quinodimethane complex salt) may be contained.

  Examples of the method for forming the solid electrolyte layer 3 include a method of applying or impregnating the conductive polymer suspension solution on the dielectric layer 2 and removing the solvent from the conductive polymer suspension solution. In addition, the solid electrolyte layer 3 in the solid electrolytic capacitor shown in FIG. 2 is formed on the dielectric layer 2 by chemical oxidation polymerization or electrolytic polymerization of a monomer that gives the first conductive polymer compound. A method of forming a compound layer 3A, and applying or impregnating the above-mentioned conductive polymer suspension on the first conductive polymer compound layer 3A to form a second conductive polymer compound layer 3B Can be formed.

  As a monomer that gives the first conductive polymer compound, at least one selected from pyrrole, thiophene, aniline, and derivatives thereof can be used. The dopant used when the monomer is chemically oxidatively polymerized or electrolytically polymerized to obtain the first conductive polymer compound includes benzenesulfonic acid, naphthalenesulfonic acid, phenolsulfonic acid, styrenesulfonic acid, and derivatives thereof. Acid compounds are preferred. The molecular weight of the dopant can be appropriately selected from low molecular weight compounds to high molecular weight compounds. As the solvent, only water or a mixed solvent containing water and an organic solvent soluble in water may be used.

  The method of application or impregnation is not particularly limited, but it is preferably left for several minutes to several tens of minutes after application or impregnation in order to sufficiently fill the porous polymer pores with the conductive polymer suspension. . Repeated immersion, reduced pressure method or pressurized method is preferred.

  The removal of the solvent from the conductive polymer suspension can be performed by drying the conductive polymer. The drying temperature is not particularly limited as long as the solvent can be removed, but the upper limit temperature is preferably less than 300 ° C. from the viewpoint of preventing element deterioration due to heat. The drying time must be appropriately optimized depending on the drying temperature, but is not particularly limited as long as the conductivity is not impaired.

  Before drying the conductive polymer suspension solution, the water-soluble polyhydric alcohol contained in the conductive polymer suspension solution and the water-soluble organic substance contained in the conductive polymer suspension solution are mixed at 70 to 105 ° C. The condensation polymerization reaction may be performed at a temperature of The temperature is preferably 80 to 100 ° C. In the solid electrolyte layer 3 obtained by drying, the water-insoluble resin obtained by the polycondensation reaction is present without being unevenly distributed, and due to its effect, adhesion to the dielectric layer 2 and liquid resistance It becomes the solid polymer electrolyte layer 3 excellent in property.

  The cathode conductor 4 is not particularly limited as long as it is a conductor. For example, the cathode conductor 4 can have a two-layer structure including a carbon layer 5 such as graphite and a silver conductive resin 6.

  Hereinafter, the present embodiment will be described more specifically based on examples, but the present embodiment is not limited to only these examples.

[ Reference Example 1]
(First step)
As a solvent, 3,4-ethylenedioxythiophene (1 g) as a monomer, camphorsulfonic acid (1 g) as a dopant, and iron (III) p-toluenesulfonate (9 g) functioning as an oxidizing agent and a dopant. In ethanol (30 ml). The resulting solution was stirred at room temperature for 24 hours to oxidize the monomer. At this time, the mixture changed from yellow to dark blue.

(Second step)
The mixed liquid obtained in the first step was filtered with a vacuum filtration device to recover the powder. The obtained powder was washed with pure water to remove excess oxidizing agent / dopant. Washing with pure water was repeated until the pH of the filtrate was 6-7. After the pH of the filtrate reached 6-7, it was further washed with ethanol to remove the monomer, the oxidizing agent and the oxidizing agent after reaction (iron (II) -toluenesulfonate). Washing with ethanol was performed until the color of the filtrate became colorless and transparent.

(Third process)
After the powder (0.5 g) washed in the second step was dispersed in water (50 ml), a 20% by mass aqueous solution of polystyrene sulfonic acid (weight average molecular weight: 50,000) as a polyacid (3. 3 g) was added. To this mixture, ammonium persulfate (1.5 g) as an oxidizing agent was further added, and the mixture was stirred at room temperature for 24 hours.

(Fourth process)
Add erythritol (5 g) and ortho-phthalic acid (0.3 g) to the mixture obtained in the third step and stir at room temperature for 24 hours to completely dissolve erythritol and ortho-phthalic acid. It was. The resulting aqueous polythiophene suspension was dark blue.

(Evaluation of aqueous polythiophene suspension)
100 μl of the obtained polythiophene suspension was dropped onto a glass substrate and subjected to a polycondensation reaction between erythritol and ortho-phthalic acid in a 90 ° C. thermostat, and the temperature of the thermostat was further set to 125 ° C. The conductive polymer film was formed by evaporating the solvent and drying.

  The resulting conductive polymer film was measured for surface resistance (Ω / □) and film thickness by the four probe method, and the conductivity (S / cm) was calculated. Moreover, the obtained conductive polymer film was immersed in water for 10 minutes, and the change in the conductive polymer film was observed to evaluate the liquid resistance. In addition, “○” indicates that there is no change in the conductive polymer film, “△” indicates that the conductive polymer is partially swollen, and “×” indicates that the entire conductive polymer is swollen. did. The results are shown in Table 1.

  Further, the crystallinity of the conductive polymer film was evaluated by an X-ray diffraction method. In the measurement, 2θ was scanned from 5 ° C to 40 ° C. The measurement result of X-ray diffraction is shown in FIG.

[ Reference Example 2]
In the third step, an aqueous polythiophene suspension was produced in the same manner as in Reference Example 1, except that polystyrenesulfonic acid having a weight average molecular weight of 14,000 was used as the polyacid. And except having used the obtained polythiophene suspension aqueous solution, it carried out similarly to the reference example 1, formed the conductive polymer film, and evaluated the electrical conductivity and liquid resistance. The results are shown in Table 1.

[ Reference Example 3]
In the second step, an aqueous polythiophene suspension was produced in the same manner as in Reference Example 1 except that washing with pure water and washing with ethanol were followed by washing with boiling hot pure water. And except having used the obtained polythiophene suspension aqueous solution, it carried out similarly to the reference example 1, formed the conductive polymer film, and evaluated the electrical conductivity and liquid resistance. The results are shown in Table 1.

[ Reference Example 4]
In the second step, an aqueous polythiophene suspension was produced in the same manner as in Reference Example 1, except that washing with pure water and washing with ethanol were followed by heat drying in a thermostatic bath at 125 ° C. And except having used the obtained polythiophene suspension aqueous solution, it carried out similarly to the reference example 1, formed the conductive polymer film, and evaluated the electrical conductivity and liquid resistance. The results are shown in Table 1.

[ Reference Example 5]
(First step)
The monomer 3,4-ethylenedioxythiophene (1 g) was dispersed in 100 ml of water as a solvent using a dopant and dodecylbenzenesulfonic acid (2.3 g) functioning as a surfactant. The obtained dispersion was stirred at room temperature for 1 hour to thoroughly disperse the monomer, and then ammonium persulfate (2.4 g) as an oxidizing agent was added. The obtained dispersion was stirred at room temperature for 100 hours to oxidize the monomer. At this time, the solution changed from yellow to dark blue.

(Second step)
The liquid mixture obtained in the first step was centrifuged (5,000 rpm) to collect the powder. The obtained powder was washed by a decantation method using pure water with a centrifuge to remove excess oxidant / dopant. Washing with pure water was repeated until the pH of the supernatant was 6-7.

After the third step, an aqueous polythiophene suspension was produced in the same manner as in Reference Example 1. And except having used the obtained polythiophene suspension aqueous solution, it carried out similarly to the reference example 1, formed the conductive polymer film, and evaluated the electrical conductivity and liquid resistance. The results are shown in Table 1.

[ Reference Example 6]
(First step)
The monomer 3,4-ethylenedioxythiophene (1 g) and the dopant camphorsulfonic acid (1 g) are dispersed in 100 ml of water as a solvent using polyethylene glycol (2 g) functioning as a surfactant. It was. Polyethylene glycol having a weight average molecular weight of 4,000 was used. The obtained dispersion was stirred at room temperature for 1 hour to thoroughly disperse the monomer, and then ammonium persulfate (2.4 g) as an oxidizing agent was added. The obtained dispersion was stirred at room temperature for 100 hours to oxidize the monomer. At this time, the solution changed from yellow to dark blue.

After the second step, an aqueous polythiophene suspension was produced in the same manner as in Reference Example 4. And except having used the obtained polythiophene suspension aqueous solution, it carried out similarly to the reference example 1, formed the conductive polymer film, and evaluated the electrical conductivity and liquid resistance. The results are shown in Table 1.

[ Reference Example 7]
In the fourth step, an aqueous polythiophene suspension was produced in the same manner as in Reference Example 1, except that pentaerythritol (5 g) was used as the water-soluble polyhydric alcohol. And except having used the obtained polythiophene suspension aqueous solution, it carried out similarly to the reference example 1, formed the conductive polymer film, and evaluated the electrical conductivity and liquid resistance. The results are shown in Table 1.

[ Reference Example 8]
In the fourth step, a polythiophene suspension was prepared in the same manner as in Reference Example 1, except that ethylene glycol (5 g), which is a divalent alcohol, was used as the water-soluble polyhydric alcohol. And except having used the obtained polythiophene suspension aqueous solution, it carried out similarly to the reference example 1, formed the conductive polymer film, and evaluated the electrical conductivity and liquid resistance. The results are shown in Table 1.

[ Reference Example 9]
In the same manner as in Reference Example 1, an aqueous polythiophene suspension was produced. 100 microliters of obtained polythiophene suspension aqueous solution was dripped on a glass substrate, and the conductive polymer film was formed by volatilizing a solvent completely in a 125 degreeC thermostat, and drying. Then, in the same manner as in Reference Example 1, the conductivity and liquid resistance of the obtained conductive polymer film were evaluated. The results are shown in Table 1.

[Comparative Example 1]
An aqueous polythiophene suspension was produced by the method described in Example 1 of Patent Document 1. Specifically, polystyrene sulfonic acid (2 g) having a weight average molecular weight of 4,000, 3,4-ethylenedioxythiophene (0.5 g) and iron (III) sulfate (0.05 g) are dissolved in water (20 ml). And air was introduced over 24 hours to produce an aqueous polythiophene suspension. And except having used the obtained polythiophene suspension aqueous solution, it carried out similarly to the reference example 1, formed the conductive polymer film, and evaluated the electrical conductivity and liquid resistance. The results are shown in Table 1.

[Comparative Example 2]
A polythiophene suspension was prepared in the same manner as in Comparative Example 1 except that polystyrene sulfonic acid having a weight average molecular weight of 50,000 was used. And except having used the obtained polythiophene suspension aqueous solution, it carried out similarly to the reference example 1, formed the conductive polymer film, and evaluated the electrical conductivity and liquid resistance. The results are shown in Table 1. Further, in the same manner as in Reference Example 1, the crystallinity of the conductive polymer film was evaluated by the X-ray diffraction method. The measurement result of X-ray diffraction is shown in FIG.

[Comparative Example 3]
By adding the self-emulsifying polyester dispersion (0.3 g) to the polythiophene suspension aqueous solution (20 g) obtained in Comparative Example 2, and stirring for 24 hours at room temperature to dissolve the self-emulsifying polyester dispersion. An aqueous polythiophene suspension was prepared. And except having used the obtained polythiophene suspension aqueous solution, it carried out similarly to the reference example 1, formed the conductive polymer film, and evaluated the electrical conductivity and liquid resistance. The results are shown in Table 1.

[ Reference Example 10]
Porous aluminum was used as an anode conductor made of a valve metal, and an oxide film serving as a dielectric layer was formed on the surface of the aluminum by anodic oxidation. The anode part and the cathode part were separated by an insulating resin. Next, the cathode part of the anode conductor on which the dielectric layer was formed was dipped in the aqueous polythiophene suspension produced in Reference Example 1 and then pulled up, and then subjected to a condensation polymerization reaction in a 90 ° C. constant temperature bath, and the temperature of the constant temperature bath Was dried and solidified at 125 ° C. to form a solid electrolyte layer. And a graphite layer and a silver content resin layer were formed in order on the solid electrolyte layer, and the solid electrolytic capacitor was manufactured.

The ESR (equivalent series resistance) of the obtained solid electrolytic capacitor was measured at a frequency of 100 kHz using an LCR meter. The value of ESR normalized the total cathode area to a unit area (1 cm ² ). The results are shown in Table 2.

[ Reference Example 11]
Porous aluminum was used as an anode conductor made of a valve metal, and an oxide film serving as a dielectric layer was formed on the surface of the aluminum by anodic oxidation. The anode part and the cathode part were separated by an insulating resin. Next, the cathode part of the anode conductor on which the dielectric layer was formed was mixed with a monomer solution obtained by dissolving pyrrole (10 g) in pure water (200 ml), p-toluenesulfonic acid (20 g) as a dopant, and excess as an oxidizing agent. A first conductive polymer compound layer was formed by repeating immersion and pulling up 10 times sequentially with an oxidizing agent solution in which ammonium sulfate (10 g) was dissolved in pure water (200 ml), and performing chemical oxidative polymerization. .

On the first conductive polymer compound layer, the polythiophene suspension aqueous solution produced in Reference Example 1 is dropped, and the polycondensation reaction is carried out in a constant temperature bath at 90 ° C., and the temperature of the constant temperature bath is set to 125 ° C. and dried. -Solidified to form a second conductive polymer compound layer. Then, a solid electrolytic capacitor was manufactured by sequentially forming a graphite layer and a silver-containing resin layer on the solid electrolyte layer composed of the first conductive polymer compound layer and the second conductive polymer compound layer. .

The ESR (equivalent series resistance) of the obtained solid electrolytic capacitor was measured by the same method as in Reference Example 10. The results are shown in Table 2.

[ Reference Example 12]
A solid electrolytic capacitor was manufactured in the same manner as in Reference Example 10 except that porous tantalum was used as the anode conductor made of a valve metal. The ESR (equivalent series resistance) of the obtained solid electrolytic capacitor was measured by the same method as in Reference Example 10. The results are shown in Table 2.

[Comparative Example 4]
A solid electrolytic capacitor was produced in the same manner as in Reference Example 10, except that the polythiophene suspension aqueous solution produced in Comparative Example 2 was used instead of the polythiophene suspension aqueous solution produced in Reference Example 1. The ESR (equivalent series resistance) of the obtained solid electrolytic capacitor was measured by the same method as in Reference Example 10. The results are shown in Table 2.

[Comparative Example 5]
A solid electrolytic capacitor was produced in the same manner as in Reference Example 10 except that the polythiophene suspension aqueous solution produced in Comparative Example 3 was used instead of the polythiophene suspension aqueous solution produced in Reference Example 1. The ESR (equivalent series resistance) of the obtained solid electrolytic capacitor was measured by the same method as in Reference Example 10. The results are shown in Table 2.

As shown in Table 1, the conductive polymer films obtained in Reference Examples 1 to 9 have liquid resistance equal to or higher than the conductive polymer films obtained in Comparative Examples 1 to 3. And high conductivity. That is, the effects of increasing the liquid resistance and increasing the conductivity according to the present embodiment are clear.

  The effect of increasing the liquid resistance is that the conductive polymer suspension solution contains a water-soluble polyhydric alcohol and a water-soluble organic substance having two or more functional groups capable of polycondensation with the water-soluble polyhydric alcohol. This is because a water-insoluble resin is formed without segregation in the conductive organic material obtained by drying the conductive polymer suspension.

The conductive polymer films obtained in Reference Examples 1 to 7 were excellent in liquid resistance as compared to the conductive polymer film obtained in Reference Example 8. This is because, as in Reference Examples 1 to 7, a resin having a crosslinked structure obtained by polycondensation reaction of erythritol or pentaerythritol, which is a trivalent or higher water-soluble polyhydric alcohol, and a water-soluble organic substance is the same as that in Reference Example 8. Thus, compared with a linear resin obtained by condensation polymerization reaction of ethylene glycol, which is a divalent water-soluble polyhydric alcohol, and a water-soluble organic substance, the liquid absorption is low and the liquid resistance is excellent. It is.

The conductive polymer films obtained in Reference Examples 1 to 7 were excellent in liquid resistance as compared to the conductive polymer film obtained in Reference Example 9. In Reference Examples 1 to 7, a polycondensation reaction between erythritol and ortho-phthalic acid was performed in a constant temperature bath at 90 ° C. before the conductive polymer suspension solution was dried to obtain a conductive organic material. This is because the water-insoluble resin can be sufficiently formed in the conductive organic material and the liquid resistance is improved.

  In particular, by going through the first to third steps, (1) a dopant that increases the crystallinity can be selected because of a wide range of dopant options, and (2) a solvent that is highly compatible with the monomer. Since the configuration can be selected, the degree of polymerization can be increased, and (3) since the washing is easy, the purity can be increased, and as a result, the conductivity can be increased.

  Further, in the second step, it becomes possible to increase the solubility of unnecessary components by hot water washing and / or to remove volatile components by heat treatment, and to further increase the purity. As a result, the conductivity is further increased. improves.

  Furthermore, in the fourth step, conductivity is improved by adding erythritol or pentaerythritol. This is because erythritol or pentaerythritol interacts with the undoped dopant anion (resistance component) introduced in the third step, which is present in the vicinity of the conductive polymer particles in the conductive polymer suspension solution. This is because the resistance between the conductive polymer particles is lowered and the density of the conductive polymer is increased.

As shown in Table 2, the solid electrolytic capacitors obtained in Reference Examples 10 to 12 had lower resistance (ESR) than the solid electrolytic capacitors obtained in Comparative Examples 4 to 5. In Reference Examples 10 to 12, since the conductivity of the conductive organic material used is high, the resistance of the solid electrolyte can be reduced, and the resistance (ESR) can be reduced.

Example 13
Poly (3,4-ethylenedioxythiophene) -polystyrene sulfonic acid solution (manufactured by HC Starck) (50 g), erythritol (5 g), pentaerythritol (1.25 g), ortho-phthalic acid (0. 3 g) and polydiethylene glycol phthalate diol (1.25 g) were added. Thereafter, the mixture was stirred at room temperature for 24 hours to completely dissolve the compound in the mixed solution.

  Next, 15 μl of the obtained polythiophene suspension was dropped on a glass substrate, and a polycondensation reaction was performed in a constant temperature bath at 90 ° C. Thereafter, the temperature of the thermostatic bath was set to 125 ° C., and the solvent was completely evaporated and dried to form a conductive polymer film. The adhesion and liquid resistance of the obtained conductive polymer film were evaluated. Table 3 shows the evaluation results.

  Adhesion was evaluated by a cross-cut method. Specifically, the conductive polymer film was cut into a grid with a cutter, and Teflon (registered trademark) tape was attached and peeled for evaluation. The presence or absence of peeling was judged by the appearance of the conductive polymer film.

  The liquid resistance was evaluated by a water immersion method. Specifically, the liquid resistance was evaluated by immersing the obtained conductive polymer film in water for 10 minutes and observing changes in the conductive polymer film. In addition, “◯” indicates that no change was observed in the conductive polymer film, and “X” indicates that the entire conductive polymer was swollen.

Example 14
A polythiophene suspension solution was produced in the same manner as in Example 13 except that pentaerythritol was not added, and a conductive polymer film was formed and then evaluated. Table 3 shows the evaluation results.

[ Reference Example 15]
A polythiophene suspension was prepared in the same manner as in Example 13 except that polydiethylene glycol phthalate diol was not added, and evaluation was performed after forming a conductive polymer film. Table 3 shows the evaluation results.

[Comparative Example 6]
A polythiophene suspension was produced in the same manner as in Example 13 except that pentaerythritol, ortho-phthalic acid and polydiethylene glycol phthalate diol were not added, and evaluation was performed after forming a conductive polymer film. Table 3 shows the evaluation results.

[Comparative Example 7]
A polythiophene suspension was prepared in the same manner as in Example 13 except that erythritol, pentaerythritol and ortho-phthalic acid were not added, and evaluated after forming a conductive polymer film. Table 3 shows the evaluation results.

[Comparative Example 8]
A polythiophene suspension was produced in the same manner as in Example 13 except that no additive was added to the poly (3,4-ethylenedioxythiophene) -polystyrene sulfonic acid solution to form a conductive polymer film. And then evaluated. Table 3 shows the evaluation results.

Example 16
A solid electrolytic capacitor was produced using the polythiophene suspension produced in Example 13. As the anode conductor, a 3 × 4 mm porous aluminum foil that had been subjected to surface expansion by etching was used. The anode conductor is immersed several times in a monomer solution containing 3,4-ethylenedioxythiophene as a monomer and a solution containing iron (III) p-toluenesulfonate as a dopant and ammonium persulfate as an oxidizing agent. Was repeated. By this chemical polymerization method, a first conductive polymer compound layer made of poly (3,4-ethylenedioxythiophene) was formed inside the pores of the porous body. Next, the polythiophene suspension prepared in Example 13 was dropped on the first conductive polymer compound layer. Thereafter, a polycondensation reaction was performed in a 90 ° C. constant temperature bath, and the temperature of the constant temperature bath was set to 125 ° C., followed by drying and solidification to form a second conductive polymer compound layer. A graphite layer and a silver conductive resin layer were formed in this order on the second conductive polymer compound layer to produce a solid electrolytic capacitor.

About the manufactured solid electrolytic capacitor, ESR was measured with the frequency of 100 kHz using the LCR meter. The value of ESR normalized the total cathode area to a unit area (1 cm ² ). Table 4 shows the measurement results.

Example 17
A solid electrolytic capacitor was produced in the same manner as in Example 16 except that the polythiophene suspension solution of Example 14 was used, and ESR was measured. Table 4 shows the measurement results.

[ Reference Example 18]
A solid electrolytic capacitor was produced in the same manner as in Example 16 except that the polythiophene suspension solution of Reference Example 15 was used, and ESR was measured. Table 4 shows the measurement results.

[Comparative Example 9]
A solid electrolytic capacitor was produced in the same manner as in Example 16 except that the polythiophene suspension solution of Comparative Example 6 was used, and ESR was measured. Table 4 shows the measurement results.

[Comparative Example 10]
A solid electrolytic capacitor was produced in the same manner as in Example 16 except that the polythiophene suspension solution of Comparative Example 7 was used, and ESR was measured. Table 4 shows the measurement results.

[Comparative Example 11]
A solid electrolytic capacitor was produced in the same manner as in Example 16 except that the polythiophene suspension solution of Comparative Example 8 was used, and ESR was measured. Table 4 shows the measurement results.

From Table 3, Example 13 , Example 14, and Reference Example 15 have the same or higher adhesion and liquid resistance than Comparative Examples 6 to 8, and the adhesion and liquid resistance of this embodiment are improved. The effect is obvious. This is a resin obtained by polycondensation reaction of erythritol and pentaerythritol, which are trivalent or higher water-soluble polyhydric alcohols, and a water-soluble organic substance having two or more functional groups that undergo polycondensation reaction with water-soluble polyhydric alcohol This is because it has a cross-linked structure, has low liquid absorption, and excellent liquid resistance. Comparative Example 7 is superior in adhesion and liquid resistance to Comparative Examples 6 and 8, but this is because the adhesion to the substrate was improved because it contained an organic polymer resin.

  Further, from Table 4, the solid electrolytic capacitor including the solid electrolyte produced using the conductive polymer suspension according to the present embodiment has a high conductivity of the conductive polymer, and thus reduces the resistance of the solid electrolyte. be able to. Especially Example 16 and 17 became low ESR with respect to the other Example and the comparative example. Water-insoluble polyhydric alcohol completely dissolved in a solvent and water-insoluble water-soluble substance obtained by polycondensation reaction in the drying process between the water-soluble polyhydric alcohol and a water-soluble organic substance having two or more functional groups capable of polycondensation In addition, a resin having a wide variety of structures in which a crosslinked structure and a linear structure are mixed can be obtained by including the above resin and an organic polymer resin dispersed or dissolved in a solvent. Therefore, a conductive organic material having further improved adhesion to the substrate and liquid resistance was obtained.

  Although the present invention has been described with reference to the exemplary embodiments and examples, the present invention is not limited to the above exemplary embodiments and examples. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention.

1 Anode conductor 2 Dielectric layer 3 Solid electrolyte layer 3A First conductive polymer compound layer 3B Second conductive polymer compound layer 4 Cathode conductor 5 Graphite layer 6 Silver conductive resin layer

Claims (18)

Conductive polymer, at least one of water-soluble polyhydric alcohol, oxalic acid, acetylenedicarboxylic acid, malonic acid, succinic acid, fumaric acid, malic acid, oxaloacetic acid, glutaric acid, oxoglutaric acid, adipic acid, citric acid At least one water-soluble organic substance selected from the group consisting of oxalosuccinic acid, ortho-phthalic acid, hemimellitic acid, trimesic acid, merophanic acid, benzenepentacarboxylic acid and melittic acid, the water-soluble polyhydric alcohol and the A conductive polymer suspension solution comprising at least one organic polymer resin other than a water-soluble organic substance .   The conductive polymer suspension solution according to claim 1, wherein the conductive polymer is a polymer composed of 3,4-ethylenedioxythiophene and a derivative thereof, and further contains a polyacid.   The conductive polymer suspension solution according to claim 2, wherein the polyacid contains polystyrene sulfonic acid.   The conductive polymer suspension according to claim 3, wherein the polystyrenesulfonic acid has a weight average molecular weight of 2,000 to 500,000.   The conductive polymer suspension solution according to claim 1, wherein the water-soluble polyhydric alcohol is trivalent or higher.   6. The conductive polymer suspension solution according to claim 5, wherein the water-soluble polyhydric alcohol is at least one selected from erythritol and pentaerythritol. The conductive polymer suspension solution according to any one of claims 1 to 6, wherein the water-soluble organic substance is ortho-phthalic acid. Conductive polymer suspension according to any one of claims 1 to 7 wherein the organic polymer resin is characterized in that it comprises a phthalic acid ester. The conductive polymer suspension solution according to any one of claims 1 to 8 , wherein the organic polymer resin is a compound represented by the following formula (3).
(In the formula (3), n is 2 or more.) A first step of obtaining a mixture containing a conductive polymer by chemically oxidatively polymerizing a monomer which gives a conductive polymer in a solvent containing an organic acid or a salt thereof as a dopant using an oxidizing agent;
A second step of recovering the conductive polymer from the mixture;
A third step of allowing an oxidizing agent to act on the conductive polymer in an aqueous solvent containing a polyacid;
At least one water-soluble polyhydric alcohol and oxalic acid, acetylenedicarboxylic acid, malonic acid, succinic acid, fumaric acid, malic acid, oxaloacetic acid, glutaric acid, oxoglutaric acid, adipic acid, citric acid, oxalosuccinic acid, ortho -At least one water-soluble organic material selected from the group consisting of phthalic acid, hemimellitic acid, trimesic acid, merophanic acid, benzenepentacarboxylic acid and melittic acid, and organics other than the water-soluble polyhydric alcohol and the water-soluble organic material And a fourth step of mixing at least one polymer resin. A method for producing a conductive polymer suspension solution, comprising: The method for producing a conductive polymer suspension solution according to claim 10 , wherein the monomer that gives the conductive polymer is selected from pyrrole, thiophene, aniline, and derivatives thereof. The conductive polymer suspension according to claim 10 or 11 , wherein the dopant is at least one selected from benzenesulfonic acid, naphthalenesulfonic acid, camphorsulfonic acid and derivatives thereof, and salts thereof. A method for producing a turbid solution. Wherein the first step, method for producing a conductive polymer suspension according to any one of claims 10 to 12, characterized in that in the presence of a substance having surface activity. The conductive polymer according to any one of claims 10 to 13 , wherein in the second step, the conductive polymer is washed with a solvent capable of dissolving the monomer and / or the oxidizing agent. A method for producing a suspension solution. Conductive polymer suspension, characterized by being obtained by the method according to any one of claims 10 to 14. A conductive organic material obtained by drying the conductive polymer suspension solution according to any one of claims 1 to 9 and claim 15 and removing the solvent. An electrolytic capacitor comprising the conductive polymer suspension solution according to any one of claims 1 to 9 and claim 15 , or an electrolyte layer containing the conductive organic material according to claim 16 . Forming a dielectric layer on the surface of the anode conductor made of a valve metal;
And applying or impregnating the conductive polymer suspension solution according to any one of claims 1 to 9 and claim 15 on the dielectric layer to form an electrolyte layer. Manufacturing method of electrolytic capacitor.