JP6322007B2 - Capacitor and manufacturing method thereof - Google Patents

Description

  The present invention relates to a capacitor and a manufacturing method thereof.

  In recent years, with the digitization of electronic devices, capacitors used in electronic devices are required to reduce impedance (equivalent series resistance) in a high frequency region. Furthermore, with the miniaturization and thinning of these electronic devices and the diversification of usage environments, requirements for long-term reliability of capacitors have become stricter. Conventionally, so-called functional capacitors (hereinafter abbreviated as “capacitors”) in which an oxide film of a valve metal such as aluminum, tantalum, or niobium is used as a dielectric have been used to meet this requirement.

  The general structure of this capacitor is, as shown in Patent Document 1, an anode made of a porous body of valve metal, a dielectric layer formed by oxidizing the surface of the anode, a conductive solid electrolyte layer, And a cathode on which a carbon layer, a silver layer, and the like are stacked. As the solid electrolyte layer, a conductive film containing a π-conjugated conductive polymer may be used.

  As a technique using a conductive film containing such a π-conjugated system conductive polymer, in a capacitor including the solid electrolyte having the above-described configuration, the solid electrolyte is a π-conjugated system in which a nitrogen-containing aromatic cyclic compound is added. A composition comprising a composition containing a conductive polymer as an essential component has been proposed (see Patent Document 2). The composition constituting the solid electrolyte contributes to the reduction of the equivalent series resistance (hereinafter referred to as ESR) of the capacitor, and the capacitor is obtained by a simple process of impregnating and drying the composition containing a π-conjugated conductive polymer. It has the characteristic that can be manufactured.

  In Patent Document 3, a polymer composed of repeating structural units of 3,4-ethylenedioxythiophene and polystyrene sulfonic acid or a salt thereof are mixed and stirred in an aqueous solution, and then an oxidant is added for chemical oxidative polymerization. A second polymer polymerization solution C obtained by adding a mixed aqueous solution B of non-aqueous solvent and pure water in which naphthalene sulfonic acid or the like is dissolved to the first polymer polymerization solution A is used as tantalum, niobium, aluminum, or the like. A technique is disclosed in which an external conductive polymer film is formed with a conductive polymer polymerization solution by coating on an internal conductive polymer film formed on an anodized film of a valve action metal.

  Similarly, Patent Document 4 contains naphthalene sulfonic acids, high molecular weight PSSA, boric acid, mannitol, glycols and the like on an anodized film having a precoat layer and an internal conductive polymer layer formed in order on the surface thereof. A method for producing a solid electrolytic capacitor by applying or impregnating an aqueous dispersion containing PEDOT and PSSA, providing a conductive polymer layer, and heating to dry solidification is disclosed.

JP 2003-37024 A Japanese Patent Laid-Open No. 2006-100774 JP 2008-135509 A JP 2008-311582 A

  However, the conventional capacitor has the following problems. When manufacturing a capacitor disclosed in Patent Document 3, a capacitor having excellent long-term reliability can be manufactured, but after forming an internal conductive polymer film by electrolytic polymerization, an external conductive polymer film is formed. A two-stage process is required. Even when the capacitor disclosed in Patent Document 4 is manufactured, similarly, a two-step process is required. For this reason, in addition to the treatment liquid for forming the external conductive polymer layer, equipment or treatment liquid for forming the internal conductive polymer layer is required, and the capacitor manufacturing process may be long and complicated. .

  In view of the above problems, the object of the present invention is to provide a capacitance without using a conductive polymer layer forming treatment liquid having a different composition or without forming an internal conductive polymer layer by a different method. It is an object of the present invention to provide a capacitor having a large size, low ESR, and excellent long-term reliability, and a method for manufacturing the same.

  In order to achieve the above object, an embodiment of the present invention includes an anode made of a porous body of a valve metal, a dielectric layer formed by oxidizing the anode surface, and a dielectric layer on a side opposite to the anode. In a capacitor comprising a conductive material cathode provided and a dielectric layer and a solid electrolyte layer formed between the cathode, the solid electrolyte layer includes a π-conjugated conductive polymer (a) and a π-conjugated material. In the formation conditions of the solid electrolyte layer, including a polyanion (b) doped in a conductive polymer and a reaction product of an anion other than that required for doping in the polyanion and an organic compound (c) containing an oxirane group or an oxetane group , An unreacted oxirane group or oxetane group-containing organic compound (c) and a ring-opening compound of the π-conjugated conductive polymer (a) and the polyanion (b) doped in the π-conjugated conductive polymer And a mass ratio of 200% or less relative to total a capacitor 50 mol% or more of anions other than those required to dope in polyanion is reacted with an oxirane group or oxetane group-containing organic compound (c).

  Another embodiment of the present invention is a capacitor in which the solid electrolyte layer further contains a hydroxy group-containing aromatic compound.

  Another embodiment of the present invention is a capacitor in which the solid electrolyte layer further contains a water-soluble polymer compound or a water-dispersible polymer compound.

  Another embodiment of the present invention is a capacitor in which the solid electrolyte layer further contains a sulfo group-containing dicarboxylic acid.

  Another embodiment of the present invention is a capacitor in which the solid electrolyte layer further contains an aliphatic compound having four or more hydroxyl groups in the molecule.

  Moreover, one embodiment of the present invention includes a π-conjugated conductive polymer (a), a polyanion (b) doped in the π-conjugated conductive polymer, and an anion other than that required for doping in the polyanion A step of preparing a conductive polymer dispersion containing a reaction product with an oxirane group or oxetane group-containing organic compound (c), and a surface of an anode made of a porous body of a valve metal are oxidized to form a dielectric layer. A step of forming a cathode at a position opposite to the dielectric layer, and a step of applying a conductive polymer dispersion on the surface of the dielectric layer and drying to form a solid electrolyte layer. The π-conjugated conductive polymer (a) and the π-conjugated conductive polymer of the unreacted oxirane group or oxetane group-containing organic compound (c) and its ring-opening compound in the solid electrolyte layer Doped polyanions The mass ratio with respect to the total with b) is 200% or less, and 50 mol% or more of the anion other than that required for doping in the polyanion in the conductive polymer dispersion is an oxirane group or oxetane group-containing organic compound (c) Is a method for manufacturing a capacitor.

  In another embodiment of the present invention, the polyanion (b) further comprises a π-conjugated conductive polymer (a) and a π-conjugated conductive polymer doped with an oxirane group or oxetane group-containing organic compound (c). It is a method for producing a capacitor through a step of adding to a water dispersion and reacting a polyanion (b) with an oxirane group or oxetane group-containing organic compound (c).

  Another embodiment of the present invention is a method for producing a capacitor, wherein the conductive polymer dispersion contains a high boiling point solvent.

  According to the present invention, the electrostatic capacity is high and the ESR is low without using a treatment liquid for forming a conductive polymer layer having a different composition or without forming an internal conductive polymer layer by a different method. A capacitor having excellent long-term reliability can be obtained.

  The capacitor according to this embodiment is made of an anode made of a porous body of valve metal, a dielectric layer formed by oxidizing the anode surface, and a conductive material provided on the opposite side of the dielectric layer from the anode. The capacitor includes a cathode, and a solid electrolyte layer formed between the dielectric layer and the cathode. The solid electrolyte layer contains a π-conjugated conductive polymer (a), a polyanion (b) doped in the π-conjugated conductive polymer, and an anion and an oxirane group or oxetane group other than those required for doping in the polyanion. A reaction product with the organic compound (c) is included. In addition, in the formation conditions of the solid electrolyte layer, the π-conjugated conductive polymer (a) and the π-conjugated conductive polymer of the unreacted oxirane group or oxetane group-containing organic compound (c) and the ring-opening compound thereof The mass ratio with respect to the sum total with the doped polyanion (b) is 200% or less. Further, 50 mol% or more of the anion other than that required for doping in the polyanion reacts with the oxirane group or oxetane group-containing organic compound (c).

(A. Π-conjugated conductive polymer)
The π-conjugated conductive polymer can be suitably used as long as it is an organic polymer whose main chain is composed of a π-conjugated system. Examples of the π-conjugated conductive polymer include polypyrroles, polythiophenes, polyacetylenes, polyphenylenes, polyphenylene vinylenes, polyanilines, polyacenes, polythiophene vinylenes, and copolymers thereof. From the viewpoint of easy polymerization and stability in air, polypyrroles, polythiophenes and polyanilines are preferred.

  The π-conjugated conductive polymer can obtain sufficient conductivity and compatibility with the binder even if it is not substituted, but in order to further improve conductivity and dispersibility or solubility in the binder, Functional groups such as an alkyl group, a carboxyl group, a sulfo group, an alkoxyl group, a hydroxyl group, and a cyano group may be introduced into the π-conjugated conductive polymer. Specific examples of such π-conjugated conductive polymers include polypyrrole, poly (N-methylpyrrole), poly (3-methylpyrrole), poly (3-ethylpyrrole), and poly (3-n-propylpyrrole). ), Poly (3-butylpyrrole), poly (3-octylpyrrole), poly (3-decylpyrrole), poly (3-dodecylpyrrole), poly (3,4-dimethylpyrrole), poly (3,4 Dibutylpyrrole), poly (3-carboxypyrrole), poly (3-methyl-4-carboxypyrrole), poly (3-methyl-4-carboxyethylpyrrole), poly (3-methyl-4-carboxybutylpyrrole), Poly (3-hydroxypyrrole), poly (3-methoxypyrrole), poly (3-ethoxypyrrole), poly (3-butoxypyrrole), poly 3-hexyloxypyrrole), poly (3-methyl-4-hexyloxypyrrole), poly (3-methyl-4-hexyloxypyrrole), poly (thiophene), poly (3-methylthiophene), poly (3- Ethylthiophene), poly (3-propylthiophene), poly (3-butylthiophene), poly (3-hexylthiophene), poly (3-heptylthiophene), poly (3-octylthiophene), poly (3-decylthiophene) ), Poly (3-dodecylthiophene), poly (3-octadecylthiophene), poly (3-bromothiophene), poly (3-chlorothiophene), poly (3-iodothiophene), poly (3-cyanothiophene), Poly (3-phenylthiophene), poly (3,4-dimethylthiophene), poly (3,4-di Butylthiophene), poly (3-hydroxythiophene), poly (3-methoxythiophene), poly (3-ethoxythiophene), poly (3-butoxythiophene), poly (3-hexyloxythiophene), poly (3-heptyl) Oxythiophene), poly (3-octyloxythiophene), poly (3-decyloxythiophene), poly (3-dodecyloxythiophene), poly (3-octadecyloxythiophene), poly (3,4-dihydroxythiophene), Poly (3,4-dimethoxythiophene), poly (3,4-diethoxythiophene), poly (3,4-dipropoxythiophene), poly (3,4-dibutoxythiophene), poly (3,4-dihexyl) Oxythiophene), poly (3,4-diheptyloxythiophene), poly 3,4-dioctyloxythiophene), poly (3,4-didecyloxythiophene), poly (3,4-didodecyloxythiophene), poly (3,4-ethylenedioxythiophene), poly (3,4 -Propylene dioxythiophene), poly (3,4-butenedioxythiophene), poly (3-methyl-4-methoxythiophene), poly (3-methyl-4-ethoxythiophene), poly (3-carboxythiophene) , Poly (3-methyl-4-carboxythiophene), poly (3-methyl-4-carboxyethylthiophene), poly (3-methyl-4-carboxybutylthiophene), polyaniline, poly (2-methylaniline), poly (3-isobutylaniline), poly (2-anilinesulfonic acid), poly (3-anilinesulfonic acid) And the like. Among these, one or two selected from polypyrrole, polythiophene, poly (N-methylpyrrole), poly (3-methylthiophene), poly (3-methoxythiophene), and poly (3,4-ethylenedioxythiophene) A (co) polymer comprising at least species can be suitably used from the viewpoint of resistance and reactivity. Furthermore, polypyrrole and poly (3,4-ethylenedioxythiophene) are more preferable because they have higher conductivity and can improve heat resistance. In addition, alkyl-substituted compounds such as poly (N-methylpyrrole) and poly (3-methylthiophene) are more preferable from the viewpoint of improving solvent solubility and compatibility and dispersibility when a hydrophobic resin is added. . Among the alkyl groups, a methyl group that does not adversely affect the conductivity is more preferable.

(B. Polyanion)
The component (b) used in the present invention is not particularly limited as long as it is an anionic compound. An anionic compound is a compound having an anionic group capable of causing chemical oxidation doping to the component (a) in the molecule. The anionic group of the anionic compound is preferably a sulfate ester group, a phosphate ester group, a phosphate group, a carboxyl group, a sulfone group or the like from the viewpoint of ease of production and stability. Of these anionic groups, a sulfone group, a sulfate ester group, and a carboxyl group are more preferable because the doping effect on the component (a) is excellent.

  Examples of the anionic group-containing polymer include a polymer in which an anionic group is introduced into the polymer by sulfonated a polymer having no anionic group with a sulfonating agent, or an anionic group-containing polymerizable monomer. The obtained polymer etc. are mentioned. In general, an anionic group-containing polymer is preferably produced by polymerizing an anionic group-containing polymerizable monomer in terms of ease of production.

  Examples of a method for producing an anionic group-containing polymer by polymerization of an anionic group-containing polymerizable monomer include, for example, an anionic group-containing polymerizable monomer in a solvent in the presence of an oxidizing agent and / or a polymerization catalyst. The method of manufacturing by superposition | polymerization is mentioned. Specifically, a predetermined amount of the anionic group-containing polymerizable monomer is dissolved in a solvent, kept at a constant temperature, and a solution in which a predetermined amount of an oxidizing agent and / or a polymerization catalyst is dissolved in the solvent is added to the predetermined amount. React with time. The polymer obtained by the reaction is adjusted to a certain concentration by the solvent. In this production method, an anionic group-containing polymerizable monomer may be copolymerized with a polymerizable monomer having no anionic group. The oxidizing agent, oxidation catalyst, and solvent used in the polymerization of the anionic group-containing polymerizable monomer are the same as those used in the polymerization of the precursor monomer forming the component (a).

The anionic group-containing polymerizable monomer is a monomer having a functional group capable of polymerizing with an anionic group in the molecule. Specifically, vinylsulfonic acid and its salts, allylsulfonic acid and its salts, methallylsulfonic acid and its Salts, styrenesulfonic acid and its salts, methallyloxybenzenesulfonic acid and its salts, allyloxybenzenesulfonic acid and its salts, α-methylstyrenesulfonic acid and its salts, acrylamide-t-butylsulfonic acid and its salts, 2 Acrylamide-2-methylpropanesulfonic acid and its salts, cyclobutene-3-sulfonic acid and its salts, isoprenesulfonic acid and its salts, 1,3-butadiene-1-sulfonic acid and its salts, 1-methyl-1, 3-butadiene-2-sulfonic acid and its salts, 1-methyl 1,3-butadiene-4-sulfonic acid and salts thereof, ethyl acrylate sulfonic acid _{(CH 2 = CH-COO- (} CH 2) 2 -SO 3 H) and its salts, acrylic acid propyl sulfonic acid _(CH 2 = CH—COO— (CH ₂ ) ₃ —SO ₃ H) and salts thereof, acrylic acid-t-butylsulfonic acid (CH ₂ ═CH—COO—C (CH ₃ ) ₂ CH ₂ —SO ₃ H) and salts thereof , Acrylic acid-n-butylsulfonic acid (CH ₂ ═CH—COO— (CH ₂ ) ₄ —SO ₃ H) and salts thereof, ethyl allyl sulfonic acid (CH ₂ ═CHCH ₂ —COO— (CH ₂ ) ₂ -SO ₃ H) and its salts, allyl acid -t- butyl sulfonic acid _{(CH 2 = CHCH 2 -COO-} C (CH 3) 2 CH 2 -SO 3 H) and its salts, 4-pen Phosphate ethyl sulfonic acid _{(CH 2 = CH (CH 2} ) 2 -COO- (CH 2) 2 -SO 3 H) and salts thereof, 4-pentenoic acid propyl sulfonic acid _{(CH 2 = CH (CH 2} ) 2 - _{COO- (CH 2) 3 -SO 3} H) and salts thereof, 4-pentenoic acid -n- butyl sulfonic acid _{(CH 2 = CH (CH 2} ) 2 -COO- (CH 2) 4 -SO 3 H) and salts thereof, 4-pentenoic acid -t- butyl sulfonic acid _{(CH 2 = CH (CH 2} ) 2 -COO-C (CH 3) 2 CH 2 -SO 3 H) and salts thereof, 4-pentenoic acid phenylene sulfonic acid _{(CH 2 = CH (CH 2} ) 2 -COO-C 6 H 4 -SO 3 H) and salts thereof, 4-pentenoic acid naphthalenesulfonic acid _{(CH 2 = CH (CH 2} ) 2 -COO-C 10 H 8 -S ₃ H) and salts thereof, ethyl methacrylate sulfonic acid _{(CH 2 = C (CH 3} ) -COO- (CH 2) 2 -SO 3 H) and salts thereof, propyl methacrylate sulfonic acid _(CH 2 = C _{(CH 3) -COO- (CH 2) 3} -SO 3 H) and its salts, methacrylic acid -t- butyl sulfonic acid _{(CH 2 = C (CH 3} ) -COO-C (CH 3) 2 CH 2 -SO 3 H) and its salts, methacrylic acid -n- butyl sulfonic acid _{(CH 2 = C (CH 3} ) -COO- (CH 2) 4 -SO 3 H) and its salts, methacrylic acid phenylene sulfonic acid _(CH 2 = C _{(CH 3) -COO-C 6} H 4 -SO 3 H) and its salts, methacrylic acid naphthalenesulfonic acid _{(CH 2 = C (CH 3} ) -COO-C 10 H 8 -SO 3 H) and And the like salts and the like of it. Moreover, the copolymer containing 2 or more types of these may be sufficient.

  Examples of the polymerizable monomer having no anionic group include ethylene, propene, 1-butene, 2-butene, 1-pentene, 2-pentene, 1-hexene, 2-hexene, styrene, p-methylstyrene, p. -Ethylstyrene, p-butylstyrene, 2,4,6-trimethylstyrene, p-methoxystyrene, α-methylstyrene, 2-vinylnaphthalene, 6-methyl-2-vinylnaphthalene, 1-vinylimidazole, vinylpyridine, Vinyl acetate, acrylaldehyde, acrylonitrile, N-vinyl-2-pyrrolidone, N-vinylacetamide, N-vinylformamide, N-vinylimidazole, acrylamide, N, N-dimethylacrylamide, acrylic acid, methyl acrylate, Ethyl acrylate, propyl acrylate, acrylic acid -Butyl, i-butyl acrylate, t-butyl acrylate, isooctyl acrylate, isononyl butyl acrylate, lauryl acrylate, allyl acrylate, stearyl acrylate, isobornyl acrylate, cyclohexyl acrylate, benzyl acrylate, acrylic Ethyl carbitol, phenoxyethyl acrylate, hydroxyethyl acrylate, methoxyethyl acrylate, ethoxyethyl acrylate, methoxybutyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, i methacrylate -Butyl, t-butyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, tridecyl methacrylate, stearyl methacrylate, cyclohexyl methacrylate, methacryl Benzyl acid, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, acryloylmorpholine, vinylamine, N, N-dimethylvinylamine, N, N-diethylvinylamine, N, N-dibutylvinylamine, N, N- Di-t-butylvinylamine, N, N-diphenylvinylamine, N-vinylcarbazole, vinyl alcohol, vinyl chloride, vinyl fluoride, methyl vinyl ether, ethyl vinyl ether, cyclopropene, cyclobutene, cyclopentene, cyclohexene, cycloheptene, cyclooctene 2-methylcyclohexene, vinylphenol, 1,3-butadiene, 1-methyl-1,3-butadiene, 2-methyl-1,3-butadiene, 1,4-dimethyl-1,3-butadiene, 1,2 -Dimethyl 1,3-butadiene, 1,3-dimethyl-1,3-butadiene, 1-octyl-1,3-butadiene, 2-octyl-1,3-butadiene, 1-phenyl-1,3-butadiene, 2- Examples include phenyl-1,3-butadiene, 1-hydroxy-1,3-butadiene, 2-hydroxy-1,3-butadiene and the like.

  The degree of polymerization of the anionic group-containing polymer thus obtained is not particularly limited. Usually, the monomer unit is about 10 to 100,000. From the viewpoint of solvent solubilization, dispersibility, and conductivity, 50 to 10, It is preferably about 000.

  Specific examples of the anionic group-containing polymer include polyvinylsulfonic acid, polystyrenesulfonic acid, polyisoprenesulfonic acid, polyacrylic acid ethylsulfonic acid, polyacrylic acid butylsulfonic acid, poly (2-acrylamido-2-methyl-1- Propanesulfonic acid) is more preferred.

  When the obtained anionic compound is an anionic salt, it is preferable to convert it into an anionic acid. Examples of the method for transforming into an anionic acid include an ion exchange method using an ion exchange resin, a dialysis method, and an ultrafiltration method. Among these, an ultrafiltration method is preferable from the viewpoint of easy work. When it is necessary to reduce the ion concentration, the ion exchange method is often used.

  As the combination of the component (a) and the component (b) used in the present invention, those selected from the above-mentioned groups can be used, but chemical stability, electrical conductivity, storage stability, easy availability From these points, it is preferable that the component (a) is poly (3,4-ethylenedioxythiophene) and the component (b) is polystyrene sulfonic acid. These may be synthesized by polymerization in the presence of an oxidizing agent in an aqueous solution or aqueous dispersion in which a monomer and a dopant of a conductive polymer coexist as described above, or a commercially available conductive polymer / dopant water. Dispersions may be used. Examples of commercially available conductive polymer / dopant aqueous dispersions include “Clevios” (trade name, manufactured by Heraeus, PEDOT / PSS aqueous dispersion), “Orgacon” (trade name, Agfa, PEDOT / PSS). Water dispersion).

  The content of the polyanion is preferably in the range of 0.1 to 10 mol, and more preferably in the range of 1 to 7 mol, with respect to 1 mol of the π-conjugated conductive polymer. When the polyanion content is 0.1 mol or more, the doping effect on the π-conjugated conductive polymer tends to be strong, and the conductivity is not insufficient. In addition, the solubility in a solvent increases, and it becomes easy to obtain a uniform conductive polymer solution. Further, when the polyanion content is 10 mol or less, the content ratio of the π-conjugated conductive polymer is relatively increased, and sufficient conductivity is easily obtained.

(C. Organic compound containing oxirane group or oxetane group)
The oxirane group or oxetane group-containing compound is not particularly limited as long as it is coordinated or bonded to the anion group of the polyanion. However, when one or less oxirane group or oxetane group is contained in one molecule, it is aggregated. Alternatively, the possibility of gelation is low, and when a polyfunctional oxirane group- or oxetane group-containing compound is used, it is preferable that only a part of the compound used is used. The molecular weight of the oxirane group or oxetane group-containing compound is preferably 50 to 1000 in consideration of solubility in water and volatility.

  The reaction between the anion group other than that required for doping in the polyanion and the oxirane group- or oxetane group-containing organic compound (c) is performed by the polyanion doped in the π-conjugated conductive polymer (a) and the π-conjugated conductive polymer. The complex solution with (b) and the oxirane group or oxetane group-containing organic compound (c) can be mixed and stirred and mixed at a temperature of 0 ° C to 100 ° C. If necessary, the reaction may be carried out in a mixed solvent to which a water-soluble solvent such as methanol or ethanol or a surfactant is added. After the reaction, the solvent or water, and the used oxirane group or oxetane group-containing organic compound (c) may be removed with an evaporator or the like to adjust to a necessary concentration. Therefore, the oxirane group or oxetane group-containing organic compound (c) used in the reaction is preferably 1 to 200 molar equivalents relative to the anion group in the polyanion that does not contribute to the doping of the π-conjugated conductive polymer. 1.2 to 100 equivalents, more preferably 2 to 50 equivalents. In the case of 1 molar equivalent or more, the reaction rate between the anion group other than that required for doping in the polyanion and the organic compound (c) containing the oxirane group or oxetane group is high, and the capacitor is sufficient when applied to the capacitor. It becomes easy to obtain reliability. On the other hand, in the case of 200 molar equivalents or less, the unreacted oxirane group or oxetane group-containing organic compound (c) and the ring-opening compound thereof hardly remain in the solid electrolyte. In this embodiment, 50 mol% or more of the anion other than that required for doping in the polyanion reacts with the oxirane group or oxetane group-containing organic compound (c).

  The capacitor according to this embodiment includes a π-conjugated conductive polymer (a), a polyanion (b) doped in the π-conjugated conductive polymer, an anion and an oxirane group other than those required for doping in the polyanion. Alternatively, a conductive polymer dispersion containing a reaction product with an oxetane group-containing organic compound (c) is applied and dried to form a solid electrolyte layer. Mass of the oxirane group or oxetane group-containing organic compound (c) and the ring-opening compound of the reaction with respect to the sum of the π-conjugated conductive polymer (a) and the polyanion (b) doped in the π-conjugated conductive polymer The ratio is preferably 200% or less, more preferably 110% or less, and even more preferably 100% or less. Of the unreacted oxirane group or oxetane group-containing organic compound (c) and its ring-opening compound with respect to the sum of the π-conjugated conductive polymer (a) and the polyanion (b) doped in the π-conjugated conductive polymer When the mass ratio is 200% or less, low ESR is easily realized when applied to a capacitor.

  Examples of the oxirane group or oxetane group-containing organic compound (c) used in this embodiment include propylene oxide, 2,3-butylene oxide, isobutylene oxide, 1,2-butylene oxide, 1,2-epoxyhexane, 1 , 2-epoxyheptane, 1,2-epoxypentane, 1,2-epoxyoctane, 1,3-butadiene monooxide, glycidyl methyl ether, ethyl glycidyl ether, glycidyl isopropyl ether, tert-butyl glycidyl ether, 2- (chloro Methyl) -1,2-epoxypropane, glycidol, epichlorohydrin, epibromohydrin, butyl glycidyl ether, 1,2-epoxyhexane, 2- (chloromethyl) -1,2-epoxybutane, 1,2-epoxy- H, 1H, 2H, 2H, 3H, 3H-trifluorobutane, allyl glycidyl ether, glycidyl butyrate, glycidyl methacrylate, 1-methyl-1,2-epoxycyclohexane, 1,2-epoxycyclopentane, 1,2- Examples include epoxycyclohexane, 1,2-epoxy-1H, 1H, 2H, 2H, 3H, 3H-heptadecafluorobutane, 3,4-epoxytetrahydrofuran, 3-ethyl-3-hydroxymethyloxetane.

In addition to the above materials, the capacitor according to this embodiment includes a hydroxy group-containing aromatic compound, a water-soluble polymer compound or a water-dispersible polymer compound, a sulfo group-containing dicarboxylic acid, and four or more hydroxyl groups in the molecule. A capacitor produced by adding at least one of an aliphatic compound having a high boiling point solvent, an additive for improving conductivity may be used.
(Hydroxy group-containing aromatic compound)
A hydroxy group-containing aromatic compound is a compound in which two or more hydroxy groups are bonded to an aromatic ring. This hydroxy group-containing aromatic compound has a property that the interaction between the hydroxy group and the aromatic ring is strong and hydrogen in the compound is easily released. Examples of the hydroxy group-containing aromatic compound include 1,4-dihydroxybenzene, 1,3-dihydroxybenzene, 2,3-dihydroxy-1-pentadecylbenzene, 2,4-dihydroxyacetophenone, and 2,5-dihydroxy. Acetophenone, 2,4-dihydroxybenzophenone, 2,6-dihydroxybenzophenone, 3,4-dihydroxybenzophenone, 3,5-dihydroxybenzophenone, 2,4'-dihydroxydiphenylsulfone, 2,2 ', 5,5'-tetra Hydroxydiphenylsulfone, 3,3 ′, 5,5′-tetramethyl-4,4′-dihydroxydiphenylsulfone, hydroxyquinonecarboxylic acid and its salts, 2,3-dihydroxybenzoic acid, 2,4-dihydroxybenzoic acid, 2,5-dihydroxy cheap Perfume acid, 2,6-dihydroxybenzoic acid, 3,5-dihydroxybenzoic acid, 1,4-hydroquinonesulfonic acid and its salts, 4,5-hydroxybenzene-1,3-disulfonic acid and its salts, 1,5 -Dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 1,5-dihydroxynaphthalene-2,6-dicarboxylic acid, 1,6- Dihydroxynaphthalene-2,5-dicarboxylic acid, 1,5-dihydroxynaphthoic acid, 1,4-dihydroxy-2-naphthoic acid phenyl ester, 4,5-dihydroxynaphthalene-2,7-disulfonic acid and salts thereof, 1, 8-dihydroxy-3,6-naphthalenedisulfonic acid and its salts, 6,7 Dihydroxy-2-naphthalenesulfonic acid and its salts, 1,2,3-trihydroxybenzene (pyrogallol), 1,2,4-trihydroxybenzene, 5-methyl-1,2,3-trihydroxybenzene, 5- Ethyl-1,2,3-trihydroxybenzene, 5-propyl-1,2,3-trihydroxybenzene, trihydroxybenzoic acid and its ester compounds, trihydroxyacetophenone, trihydroxybenzophenone, trihydroxybenzaldehyde, trihydroxy Anthraquinone, 2,4,6-trihydroxybenzene, tetrahydroxy-p-benzoquinone, tetrahydroxyanthraquinone and the like can be mentioned.

  Among the hydroxy group-containing aromatic compounds, from the viewpoint of conductivity, compounds having a sulfo group and / or a carboxy group, which are anionic groups, can be doped into the π-conjugated conductive polymer. The content of the hydroxy group-substituted aromatic compound is preferably in the range of 0.05 to 10 mol and more preferably in the range of 0.3 to 5 mol with respect to 1 mol of the polyanion. When the content of the hydroxy group-substituted aromatic compound is 0.05 mol or more, both conductivity and heat resistance can be improved. Further, when the content of the hydroxy group-substituted aromatic compound is 10 mol or less, the content of the π-conjugated conductive polymer in the solid electrolyte layer is increased, and sufficient conductivity is easily obtained. The physical properties of the electrolyte layer are difficult to change.

(Water-soluble polymer compound or water-dispersible polymer compound)
A water-soluble polymer compound is a compound that exhibits water solubility by introducing a hydrophilic group into the main chain or side chain of the polymer. Specific examples of the water-soluble polymer compound include, for example, polyoxyalkylene, water-soluble polyurethane, water-soluble polyester, water-soluble polyamide, water-soluble polyimide, water-soluble polyacryl, water-soluble polyacrylamide, polyvinyl alcohol, polyacrylic acid and the like. Is mentioned. Among the water-soluble polymer compounds, polyoxyalkylene is preferable because the withstand voltage of the capacitor becomes higher. The terminal of polyoxyalkylene may be substituted with various substituents.

  Specific examples of polyoxyalkylene include triethylene glycol, oligoethylene glycol, polyethylene glycol, triglycerol, tetraglycerol, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, diglycerol polyethyl ether, tripropylene glycol, polypropylene glycol, polyoxy Examples thereof include ethylene alkyl ether, polyoxyethylene glycerin fatty acid ester, and polyoxyethylene fatty acid amide. Water-soluble polyurethane, water-soluble polyester, water-soluble polyamide, and water-soluble polyimide are each substituted or unsubstituted polyurethane, substituted or unsubstituted polyester, substituted or unsubstituted polyamide, substituted or unsubstituted polyimide, sulfone. Examples thereof include polymers having an acid group introduced therein. Examples of the water-soluble polyacryl include those obtained by (co) polymerizing the above-described acrylic compounds.

  The water-soluble polymer compound may be a homopolymer, a copolymer, or a mixture of two or more types of water-soluble polymer compounds. The mass average molecular weight of the water-soluble polymer compound is preferably in the range of 100 to 5,000,000, and more preferably in the range of 400 to 1,000,000. When the weight average molecular weight of the water-soluble polymer compound is 5,000,000 or less, the mixing property in the conductive polymer solution is increased and the permeability into the pores of the dielectric layer is increased. It becomes easy to demonstrate the voltage improvement effect. When the mass average molecular weight is 100 or more, the water-soluble polymer compound is difficult to move in the solid electrolyte layer, so that the withstand voltage tends to increase.

  The above-mentioned water-soluble compounds can interact with the π-conjugated conductive polymer to improve the electrical conductivity of the π-conjugated conductive polymer, so that the conductivity of the solid electrolyte layer is also improved. To do. That is, the water-soluble compound also functions as a highly conductive agent. A water-dispersible polymer compound is a compound in which a part of a low hydrophilic compound is substituted with a highly hydrophilic functional group, or a compound having a highly hydrophilic functional group around a low hydrophilic compound. And those that disperse in water without precipitating. Specific examples include polyester, polyurethane, acrylic resin, silicone resin, and emulsions of these polymers.

  The particle diameter of the emulsion is preferably smaller than the pore diameter of the dielectric layer and more preferably ½ or less of the pore diameter of the dielectric layer from the viewpoint of permeability into the dielectric layer. The amount of the water-soluble polymer compound and the water-dispersible polymer compound is 100 parts by mass in total of the π-conjugated conductive polymer (a) and the polyanion (b) doped in the π-conjugated conductive polymer. It is preferably 1 to 10,000 parts by mass, and more preferably 50 to 5,000 parts by mass. When the content of the water-soluble polymer compound and the water-dispersible polymer compound is 1 part by mass or more, it is easy to increase the withstand voltage of the capacitor. When the content is 10,000 parts by mass or less, the conductivity of the solid electrolyte layer Tend to increase, and the ESR of the capacitor tends to decrease.

(Sulfo group-containing dicarboxylic acid)
The sulfo group-containing dicarboxylic acid is a compound containing one or more sulfo groups and two or more carboxylic acids in the molecule. 4-sulfophthalic acid, 5-sulfoisophthalic acid, 2-sulfoterephthalic acid, 4-sulfonaphthalene Examples include -1,8-dicarboxylic acid, 4-sulfonaphthalene-2,7-dicarboxylic acid, 5-sulfonaphthalene-1,4-dicarboxylic acid, sulfosuccinic acid, and the like. These sulfo group-containing dicarboxylic acids may be salts, and the carboxylic acid may form an ester with a lower alcohol. The content of the sulfo group-containing dicarboxylic acid is preferably in the range of 0.05 to 30 mol, more preferably in the range of 0.3 to 10 mol, with respect to 1 mol of the polyanion. When the content of the sulfo group-containing dicarboxylic acid is 0.05 mol or more, the conductivity and heat resistance are easily improved. Further, when the content of the sulfo group-containing dicarboxylic acid is 30 mol or less, the content of the π-conjugated conductive polymer in the solid electrolyte layer is increased, and sufficient conductivity can be easily obtained. The physical properties of the are difficult to change.

(Aliphatic compounds having 4 or more hydroxyl groups in the molecule)
Suitable aliphatic compounds having 4 or more hydroxyl groups in the molecule include saccharides, sugar alcohols, polyhydroxys and the like. Specific examples include sugars and sugar derivatives such as sucrose, maltose, xylose, glucose, and polydextrose, sugar alcohols such as sorbitol, mannitol, xylitol, pentaerythritol, and dipentaerythritol, and polyvinyl alcohol. From the viewpoint of the thermal stability of the solid electrolyte layer, a compound having a high melting point is preferred. More preferable examples include pentaerythritol and dipentaerythritol having a melting point of 170 ° C. or higher. The content of the aliphatic compound having four or more hydroxyl groups in the molecule is 100 parts by mass in total of the π-conjugated conductive polymer (a) and the polyanion (b) doped in the π-conjugated conductive polymer. The amount is preferably 10 to 1000 parts by mass, more preferably 5 to 500 parts by mass. If it is this range, it will be easy to make heat resistance and electroconductivity of a solid electrolyte layer compatible. In the case of 1000 parts by mass or less, the film forming property of the solid electrolyte becomes good.

(High boiling point solvent)
The high boiling point solvent referred to in this embodiment is a liquid organic compound having a boiling point of 100 ° C. or higher, and has an effect of remarkably improving conductivity. Examples of the high-boiling solvent used in this embodiment include N-methyl-2-pyrrolidone, γ-butyrolactone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, ethylene glycol monoalkyl ether, ethylene Examples include glycol dialkyl ether, diethylene glycol, diglycerol, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, and dipropylene glycol. The content of the high boiling point solvent is preferably 100 to 2000 parts by mass with respect to 100 parts by mass in total of the π-conjugated conductive polymer (a) and the polyanion (b) doped in the π-conjugated conductive polymer. Yes, more preferably 150 to 1000 parts by mass. When the amount is 100 parts by mass or more, the effect of improving the conductivity is easily exhibited. When the amount is 2000 parts by mass or less, the stability of the solution is easily improved, and baking can be performed in a short time.

(Additives for improving conductivity)
Various additives can be used as the compound for improving the conductivity of the conductive polymer. Examples include organic compounds containing amide groups, organic compounds containing imide groups, organic compounds containing lactam groups, compounds containing lactone groups, thiodiglycols, thiodicarboxylic acids, cresols, and the like. The addition of these compounds exhibits a significant effect on the improvement of conductivity. Therefore, these compounds are preferably selected and used as appropriate.

  Next, an embodiment of a method for manufacturing a capacitor (also referred to as a capacitor) according to the present invention will be described.

The method for manufacturing a capacitor according to this embodiment includes a π-conjugated conductive polymer (a), a polyanion (b) doped in the π-conjugated conductive polymer, and an anion other than that required for doping in the polyanion. Preparing a conductive polymer dispersion containing a reaction product of the oxirane group or oxetane group-containing organic compound (c);
Oxidizing the surface of the anode made of a porous body of valve metal to form a dielectric layer;
Forming a cathode at a position facing the dielectric layer;
Applying the conductive polymer dispersion to the surface of the dielectric layer and drying to form a solid electrolyte layer,
Under the conditions for forming the solid electrolyte layer, the unreacted oxirane group or oxetane group-containing organic compound (c) in the solid electrolyte layer and the ring-opening compound thereof are π-conjugated conductive polymer (a) and π-conjugated conductive properties. The mass ratio to the total of the polyanion doped in the polymer (b) is 200% or less, and 50 mol% or more of the anion other than that required for doping in the polyanion is an oxirane group or oxetane group-containing organic compound (c). It is characterized by reacting.

(Method for preparing conductive polymer dispersion)
π-conjugated conductive polymer (a), polyanion (b) doped in π-conjugated conductive polymer, anion and oxirane group or oxetane group-containing organic compound (c) other than that required for doping in the polyanion The method for preparing the reaction product is as described above. The reaction product thus obtained includes a hydroxy group-containing aromatic compound, a water-soluble polymer compound or a water-dispersible polymer compound, a sulfo group-containing dicarboxylic acid, an aliphatic compound having four or more hydroxyl groups in the molecule, A conductive polymer dispersion is prepared by mixing and stirring a boiling point solvent, an additive for improving conductivity, a binder, a silane coupling agent, water, and the like, and if necessary, heated and dissolved. Furthermore, the stability of the conductive polymer dispersion can be improved by performing a dispersion treatment with a bead mill, a high-pressure disperser, ultrasonic waves, or the like. Among them, the dispersion treatment using a high-pressure disperser is more preferable because the dispersion stability can be easily improved.

(High pressure dispersion process)
High-pressure dispersion treatment is a treatment in which a polyanion or conductive polymer dispersion is dispersed using a high-pressure disperser by causing the solution to be dispersed to collide oppositely at high pressure or passing it through an orifice or slit at high pressure. is there. As the high pressure disperser, for example, a commercially available high pressure disperser such as a high pressure homogenizer can be suitably used. The high-pressure homogenizer is an apparatus including, for example, a high-pressure generating unit that pressurizes a solution to be dispersed, and an opposing collision unit, an orifice unit, or a slit unit that performs dispersion. As the high-pressure generator, a high-pressure pump such as a plunger pump is preferably used. There are various types of high-pressure pumps such as a series type, a double type, and a triple type, and any type can be adopted.

  In the case of causing the solution to be dispersed to collide with each other at high pressure in the high-pressure dispersion treatment, the effect of the high-pressure dispersion treatment is more exerted, so that the treatment pressure is preferably 50 MPa or more, more preferably 100 MPa or more. , 130 MPa or more is particularly preferable. Moreover, since a problem tends to arise in the pressure resistance and durability of the high-pressure disperser at a processing pressure exceeding 300 MPa, the processing pressure is preferably 300 MPa or less.

  The above-mentioned orifice refers to a mechanism in which a thin plate (orifice plate) having a fine hole having a circular shape or the like is inserted into a straight pipe and the flow path of the straight pipe is rapidly narrowed. The above-mentioned slit refers to a mechanism in which a pair of members made of a strong material such as metal or diamond are arranged with a slight gap. When the solution to be dispersed in the high-pressure dispersion treatment is passed through an orifice or a slit, the effect of the high-pressure dispersion treatment is more exhibited. Therefore, the differential pressure between the upstream side and the downstream side is preferably 50 MPa or more, and 100 MPa or more. More preferably, it is particularly preferably 130 MPa or more. Further, when the pressure difference is 300 MPa or less, it is difficult for the high pressure disperser to have a problem with the pressure resistance and durability. Therefore, the pressure difference is preferably 300 MPa or less. Specific examples of the high-pressure homogenizer include a trade name Nanoviter manufactured by Yoshida Kikai Kogyo Co., a trade name Microfluidizer manufactured by Microfluidics, and an optimizer manufactured by Sugino Machine.

  The number of high-pressure dispersion treatments is not particularly limited, but is preferably in the range of 1 to several tens of times. This is because if the number of times of distributed processing is too large, an effect corresponding to the number of times of processing is not exhibited even if the number of times of processing is increased. In the high-pressure dispersion treatment, a high shear force is generated in the case of an oncoming collision or when passing through a rapidly narrowed flow path, thereby increasing the dispersibility of the polyanion or complex contained in the solution to be dispersed. be able to. When high-pressure dispersion treatment is performed by a high-pressure disperser, the temperature of the liquid after treatment increases in principle. Therefore, it is preferable to lower the temperature of the solution to be dispersed before the dispersion treatment in advance. However, since the characteristics may change when the solution to be dispersed is frozen, it is preferable to control it so that it does not freeze. Therefore, the temperature of the solution to be dispersed before the dispersion treatment is preferably 0 to 60 ° C., more preferably 0 to 40 ° C., and particularly preferably 0 to 30 ° C. when the dispersion medium is water. If the temperature of the solution to be subjected to the dispersion treatment before the dispersion treatment is set to 60 ° C. or lower, modification of the π-conjugated conductive polymer or polyanion can be prevented. Furthermore, the solution after the high-pressure dispersion treatment may be cooled by passing through a heat exchanger having a refrigerant temperature of −30 to 20 ° C.

(Electrolytic oxidation process)
In the capacitor manufacturing method according to this embodiment, first, in the electrolytic oxidation step, the surface of the anode made of the valve metal is electrolytically oxidized and subjected to chemical conversion treatment to form a dielectric layer. Examples of the method for electrolytically oxidizing the anode surface include a method in which a voltage is applied in an electrolytic solution such as an ammonium adipate aqueous solution to anodize the anode surface.
(Cathode arrangement process)
Next, a cathode formed of a conductor such as an aluminum foil is disposed opposite to the surface of the dielectric layer via a separator.
(Formation process of solid electrolyte layer)
Next, in the solid electrolyte layer forming step, a solid electrolyte layer is formed between the dielectric layer and the cathode. As a method for forming the solid electrolyte layer, a method in which an element having a dielectric layer and a cathode is immersed in the conductive polymer dispersion, and the conductive polymer solution is applied to the surface of the dielectric layer by a known coating apparatus. And a method of spraying the conductive polymer solution onto the surface of the dielectric layer with a known spraying device. Moreover, you may make it a pressure reduction state as needed at the time of immersion or application | coating. After the immersion or application of the conductive polymer solution, it is preferably dried by a known drying method such as hot air drying.

  The capacitor may be filled with an electrolytic solution between the dielectric layer and the cathode as necessary. The electrolytic solution is not particularly limited as long as the electric conductivity is high, and examples thereof include a well-known electrolyte dissolved in a well-known electrolyte solution. Examples of the electrolyte solution solvent include alcohol solvents such as ethylene glycol, diethylene glycol, propylene glycol, 1,4-butanediol, and glycerin, lactone solvents such as γ-butyrolactone, γ-valerolactone, and δ-valerolactone, Examples thereof include amide solvents such as N-methylformamide, N, N-dimethylformamide, N-methylacetamide and N-methylpyrrolidinone, nitrile solvents such as acetonitrile and 3-methoxypropionitrile, water and the like. Examples of the electrolyte include adipic acid, glutaric acid, succinic acid, benzoic acid, isophthalic acid, phthalic acid, terephthalic acid, maleic acid, toluic acid, enanthic acid, malonic acid, formic acid, 1,6-decanedicarboxylic acid, 5,6 -Decane dicarboxylic acid such as decanedicarboxylic acid, octane dicarboxylic acid such as 1,7-octane dicarboxylic acid, organic acid such as azelaic acid and sebacic acid, or boric acid, polyhydric alcohol of boric acid obtained from boric acid and polyhydric alcohol Complex compounds, inorganic acids such as phosphoric acid, carbonic acid, and silicic acid are used as anionic components, and primary amines (methylamine, ethylamine, propylamine, butylamine, ethylenediamine, etc.), secondary amines (dimethylamine, diethylamine, dipropylamine, Methylethylamine, diphenylamine, etc.), tertiary amine (trimethyl) Amine, triethylamine, tripropylamine, triphenylamine, 1,8-diazabicyclo (5,4,0) -undecene-7, etc.), tetraalkylammonium (tetramethylammonium, tetraethylammonium, tetrapropylammonium, tetrabutylammonium, Examples thereof include electrolytes containing methyltriethylammonium, dimethyldiethylammonium, etc.) as cationic components.

(Applying process)
Next, in the applying step, a process for applying a DC voltage between the anode and the cathode is performed to obtain a capacitor. The DC voltage to be applied is not particularly limited, but in terms of reducing the leakage current, it is preferably 30% or more, more preferably 50% or more, and more preferably 80% or more of the rated voltage of the obtained capacitor. It is particularly preferred. Here, the rated voltage is a value determined by an applied voltage (formation voltage) or the like when electrolytically oxidizing the anode. Usually, the rated voltage is not more than the formation voltage. In addition, the voltage applied in the application step is preferably 20% or more, more preferably 30% or more, and more preferably 40% or more of the formation voltage in the electrolytic oxidation step because the leakage current becomes smaller. It is particularly preferred.

  The environmental temperature at which the application step is performed is preferably 30 ° C. or higher, more preferably 40 to 200 ° C., particularly preferably 80 to 180 ° C., and most preferably 100 to 160 ° C., since leakage current can be further reduced. The application process time is appropriately adjusted according to the DC voltage to be applied and the environmental temperature. For example, in order to further reduce the leakage current, it is preferable to extend the application time as the applied DC voltage is lower. Specifically, when the DC voltage to be applied is less than 50% of the rated voltage of the capacitor, it is preferable to set the application time to 5 minutes or more in order to reduce the leakage current. When the DC voltage to be applied is high, the application time may be shortened. Specifically, when the applied DC voltage is 50% or more of the rated voltage of the capacitor, the leakage current can be reduced even if the application time is less than 5 minutes. Further, in order to reduce the leakage current, it is preferable to extend the application time as the environmental temperature is lower. If the environmental temperature is high, the application time may be shortened.

  Next, examples of the capacitor and the manufacturing method thereof according to the present invention will be described. However, the present invention is not limited to the following examples.

(1) Production Example 1 Preparation of Polystyrene Sulfonic Acid 1.14 g of ammonium persulfate oxidant solution dissolved in 10 ml of water in advance while dissolving 206 g of sodium styrene sulfonate in 1000 ml of ion exchange water and stirring at 80 ° C. Was added dropwise over 20 minutes and the solution was stirred for 2 hours. To the sodium polystyrene sulfonate-containing solution thus obtained, 1000 ml of a 10% by mass sulfuric acid aqueous solution and 10000 ml of ion-exchanged water are added, and about 10,000 ml of the polystyrene sulfonic acid-containing solution is removed by an ultrafiltration method. 10,000 ml of ion-exchanged water was added, and about 10,000 ml of solution was removed by ultrafiltration. The above ultrafiltration operation was repeated three times. The ultrafiltration conditions were as follows (the same applies to other examples).
Molecular weight cut off of ultrafiltration membrane: 30000
Cross flow type Supply liquid flow rate: 3000 ml / min Membrane partial pressure: 0.12 Pa
Water in the obtained solution was removed under reduced pressure to obtain colorless solid polystyrene sulfonic acid. The polystyrene sulfonic acid had a mass average molecular weight of about 220,000.

(2) Production Example 2 Preparation of PEDOT-PSS aqueous dispersion 36.7 g of polystyrene sulfonic acid obtained in Production Example 1 was dissolved in 2000 ml of ion-exchanged water. 14.2 g of 3,4-ethylenedioxythiophene was added here, and it stirred and mixed at 20 degreeC. While maintaining the mixed solution thus obtained at 20 ° C., 240 ml of an aqueous solution in which 29.64 g of ammonium persulfate and 8.0 g of ferric sulfate were dissolved was added dropwise over 1 hour, followed by stirring for 3 hours. 2000 ml of ion-exchanged water was added to the resulting reaction solution, and about 2000 ml of solution was removed using an ultrafiltration method. This operation was repeated three times. Then, 200 ml of 10% by mass sulfuric acid aqueous solution and 2000 ml of ion exchange water are added to the treatment liquid subjected to the above filtration treatment, and about 2000 ml of the treatment liquid is removed using an ultrafiltration method. Water was added and about 2000 ml of liquid was removed using ultrafiltration. This operation was repeated three times. Furthermore, 2000 ml of ion-exchanged water was added to the obtained treatment liquid, and about 2000 ml of the treatment liquid was removed using an ultrafiltration method. This operation was repeated 5 times, the concentration was adjusted with ion-exchanged water, and a 1.6% by mass dark blue PEDOT-PSS aqueous dispersion was obtained.

(3-1) Production Example 3-1 Preparation of Reaction Product (C-1) of PEDOT-PSS and Oxirane Group-Containing Organic Compound To 100 g of 1.6 mass% PEDOT-PSS aqueous dispersion obtained in Production Example 2 5 g of glycidol (manufactured by Junsei Chemical Industry Co., Ltd., Mw = 74.08) was added and stirred at room temperature for 3 days to obtain a reaction product of PEDOT-PSS and glycidol (hereinafter referred to as C-1). Confirmation of the reaction was performed by the fact that the peak derived from the sulfone group decreased by FTIR, the peak derived from the sulfonate group increased, and the epoxy group in the system disappeared by 90% or more according to JIS K7236. Moreover, the reduction rate of the peak derived from the sulfone group by FTIR was made into the reaction rate. The reaction rate in this production example was 74%. In addition, in order to confirm the contents of the unreacted oxirane group or oxetane group-containing organic compound (c) and the ring-opening compound under the formation conditions of the solid electrolyte layer, the reaction solution was placed on a filter paper laid on an aluminum dish. It dried for 10 minutes with a 120 degreeC hot air dryer, and measured the weight change. The non-volatile content at 120 ° C. was 2.3%. When the reaction rate is 74%, the calculated value of the non-volatile content is 1.87%, so the mass ratio of glycidol remaining in the system or its ring-opening compound to the PEDOT-PSS solid content (hereinafter, residual rate) Is 20%.

(3-2) Production Example 3-2 Preparation of Reaction Product (C-2) of PEDOT-PSS and Oxirane Group-Containing Organic Compound To 100 g of 1.6 mass% PEDOT-PSS aqueous dispersion obtained in Production Example 2 10 g of glycidol (manufactured by Junsei Chemical Industry Co., Ltd., Mw = 74.08) was added, and the same operation as in Production Example 3-1 was performed to obtain a reaction product of PEDOT-PSS and glycidol (hereinafter referred to as C-2). It was. Moreover, operation similar to manufacture example 3-1 was performed, and when the reaction rate of C-2 and the residual rate in 120 degreeC were measured, the reaction rate was 90% and the residual rate was 37%.

(3-3) Production Example 3-3 Preparation of Reaction Product (C-3) of PEDOT-PSS and Oxirane Group-Containing Organic Compound To 100 g of 1.6 mass% PEDOT-PSS aqueous dispersion obtained in Production Example 2 15 g of glycidol (manufactured by Junsei Chemical Industry Co., Ltd., Mw = 74.08) was added, and the same operation as in Production Example 3-1 was performed to obtain a reaction product of PEDOT-PSS and glycidol (hereinafter referred to as C-3). It was. Moreover, operation similar to manufacture example 3-1 was performed, and the reaction rate of C-3 and the residual rate in 120 degreeC were measured, The reaction rate was 94% and the residual rate was 105%.

(3-4) Production Example 3-4 Preparation of Reaction Product (C-4) of PEDOT-PSS and Oxirane Group-Containing Organic Compound To 100 g of 1.6 mass% PEDOT-PSS aqueous dispersion obtained in Production Example 2 8 g of glycidyl methyl ether (manufactured by Wako Pure Chemical Industries, Ltd., Mw = 88.11) was added, and the same operation as in Production Example 3-1 was performed. A reaction product of PEDOT-PSS and glycidyl methyl ether (hereinafter referred to as C-4) ). Moreover, operation similar to manufacture example 3-1 was performed, and when the reaction rate of C-4 and the residual rate in 120 degreeC were measured, the reaction rate was 85% and the residual rate was 40%.

(3-5) Production Example 3-5 Preparation of Reaction Product (C-5) of PEDOT-PSS and Oxirane Group-Containing Organic Compound To 100 g of 1.6 mass% PEDOT-PSS aqueous dispersion obtained in Production Example 2 5 g of ethyl glycidyl ether (manufactured by Tokyo Kasei Kogyo Co., Ltd., Mw = 102.13) is added, and the same operation as in Production Example 3-1 is performed, and a reaction product of PEDOT-PSS and ethyl glycidyl ether (hereinafter referred to as C-5) .) Moreover, operation similar to manufacture example 3-1 was performed, and the reaction rate of C-5 and the residual rate in 120 degreeC were measured, The reaction rate was 59% and the residual rate was 76%.

(3-6) Production Example 3-6 Preparation of Reaction Product (C-6) of PEDOT-PSS and Oxirane Group-Containing Organic Compound To 100 g of 1.6 mass% PEDOT-PSS aqueous dispersion obtained in Production Example 2 10 g of lauryl alcohol (EO) 15 glycidyl ether (manufactured by Nagase ChemteX Corporation, EX-171, Mw = 901.34) was added, and the same operation as in Production Example 3-1 was performed. PEDOT-PSS and lauryl alcohol (EO) 15 A reaction product of glycidyl ether (hereinafter referred to as C-6) was obtained. Further, the same operation as in Production Example 3-1 was performed, and the reaction rate of C-6 and the residual rate at 120 ° C. were measured. As a result, the reaction rate was 58% and the residual rate was 360%.

(3-7) Production Example 3-7 Preparation of Reaction Product (C-7) of PEDOT-PSS and Oxirane Group-Containing Organic Compound To 100 g of 1.6 mass% PEDOT-PSS aqueous dispersion obtained in Production Example 2 10 g of 2-ethylhexyl glycidyl ether (manufactured by Tokyo Chemical Industry Co., Ltd., Mw = 186.29) was added, the same operation as in Production Example 3-1 was performed, and a reaction product of PEDOT-PSS and 2-ethylhexyl glycidyl ether (hereinafter referred to as C). -7). Moreover, operation similar to manufacture example 3-1 was performed, and the reaction rate of C-7 and the residual rate in 120 degreeC were measured, The reaction rate was 4% and the residual rate was 530%.

(3-8) Production Example 3-8 Preparation of Reaction Product (C-8) of PEDOT-PSS and Oxirane Group-Containing Organic Compound To 100 g of 1.6 mass% PEDOT-PSS aqueous dispersion obtained in Production Example 2 The same operation as in Production Example 3-1 was performed except that 1 g of glycidol was added to obtain a reaction product of PEDOT-PSS and glycidol (hereinafter referred to as C-8). Further, the same operation as in Production Example 3-1 was performed, and the reaction rate of C-8 and the residual rate at 120 ° C. were measured. The reaction rate was 26%, and the residual rate was 12%.

(4) Manufacture of capacitor element After connecting an anode lead terminal to an etched aluminum foil (anode foil), a voltage of 130 V was applied in an aqueous solution of 10% by weight of ammonium adipate to form (oxidize) aluminum. A dielectric layer was formed on both sides of the foil to obtain an anode foil. Next, on both surfaces of the anode foil, an opposing aluminum cathode foil with cathode lead terminals welded was laminated via a cellulose separator, and this was wound into a cylindrical shape to obtain a capacitor element.

(5) Preparation of driving electrolyte solution 100 g of γ-butyrolactone, 10 g of sulfolane, and 25 g of tetramethylammonium phthalate were mixed and dissolved to obtain a driving electrolyte solution.

(6) Manufacture of capacitors (Example 1)
To 100 g of the reaction product (C-1) of PEDOT-PSS and glycidol obtained from Production Example 3-1, 0.5 g of pyrogallol, 10 g of polyethylene glycol 400 (manufactured by Wako Pure Chemical Industries, Ltd.), 1.0 g of pentaerythritol, and Dimethyl sulfoxide 5.0g was added and it stirred at room temperature. Subsequently, it disperse | distributed so that it might become a liquid viscosity of 18 mPa * s in 25 degreeC with a high voltage | pressure disperser (Yoshida Kikai Kogyo Co., Ltd. nanometer), and the conductive polymer composition (1) was obtained. The capacitor element obtained in (4) above was immersed in the conductive polymer composition (1) under reduced pressure, and then dried for 10 minutes with a 120 ° C. hot air dryer. Furthermore, the immersion in the conductive polymer composition (1) was repeated twice to form a solid electrolyte layer containing the conductive polymer composite on the surface of the dielectric layer. Further, after being immersed in the driving electrolyte obtained in the above (5) under reduced pressure, a capacitor element is loaded in an aluminum case, sealed with a sealing rubber, and a voltage of 75 V is applied in an atmosphere of 120 ° C. The capacitor was produced by applying for a time. About the obtained capacitor, the electrostatic capacity in 120 Hz, the initial value of ESR in 100 kHz, and the rate of change of ESR were measured using LCZ meter 2345 (made by NF circuit design block company). As shown in Table 1, the measurement results are as follows: ESR initial value (mΩ) = 19.8, capacitance (μF) = 33.3, ESR change rate 1 (%) = 0.3, ESR change rate 2 ( %) = 8.
The ESR change rate of the capacitor was measured as follows.
-ESR change rate 1
After the obtained electrolytic capacitor was heat-treated in an oven at 230 ° C. for 3 minutes and then allowed to cool at room temperature for 15 minutes, ESR was measured and ESR change rate 1 was determined from the following formula.
ESR change rate 1 (%) = (ESR after heat treatment−ESR before heat treatment) / ESR × 100 before heat treatment
ESR change rate 2
The obtained electrolytic capacitor was heat-treated in an oven at 135 ° C. for 500 hours, then allowed to cool at room temperature for 15 minutes, ESR was measured, and ESR change rate 2 was determined from the following formula.
ESR change rate 2 (%) = (ESR after heat treatment−ESR before heat treatment) / ESR × 100 before heat treatment

(Example 2)
The reaction product of PEDOT-PSS and glycidol obtained from Production Example 3-2 (C-2) 100 g was used as a reaction product of PEDOT-PSS and the oxirane group-containing organic compound, and polyethylene glycol 400 was changed to 5 g. A conductive polymer composition (2) was prepared according to Example 1 to produce a capacitor. For the obtained capacitor, the capacitance at 120 Hz, the initial value of ESR at 100 kHz, and the rate of change of ESR were measured in the same manner as in Example 1. As shown in Table 1, the measurement results are as follows: ESR initial value (mΩ) = 19.4, capacitance (μF) = 33.2, ESR change rate 1 (%) = − 1.5, ESR change rate 2 (%) = 5.

(Example 3)
Using PEDOT-PSS and glycidol reaction product (C-3) 100 g obtained from Production Example 3-3 as a reaction product of PEDOT-PSS and an oxirane group-containing organic compound, a conductive polymer according to Example 2 was used. A composition (3) was prepared to produce a capacitor. For the obtained capacitor, the capacitance at 120 Hz, the initial value of ESR at 100 kHz, and the rate of change of ESR were measured in the same manner as in Example 1. As shown in Table 1, the measurement results are as follows: ESR initial value (mΩ) = 20.5, capacitance (μF) = 33.0, ESR change rate 1 (%) = 5.0, ESR change rate 2 ( %) = 5.

Example 4
Conductivity according to Example 1 using 100 g of the reaction product (C-4) of PEDOT-PSS and glycidyl methyl ether obtained from Production Example 3-4 as a reaction product of PEDOT-PSS and the oxirane group-containing organic compound. A polymer composition (4) was prepared to produce a capacitor. For the obtained capacitor, the capacitance at 120 Hz, the initial value of ESR at 100 kHz, and the rate of change of ESR were measured in the same manner as in Example 1. As shown in Table 1, the measurement results are as follows: ESR initial value (mΩ) = 19.0, capacitance (μF) = 32.5, ESR change rate 1 (%) = 5.1, ESR change rate 2 ( %) = 10.

(Example 5)
Conductivity according to Example 1 using 100 g of the reaction product (C-5) of PEDOT-PSS and ethyl glycidyl ether obtained from Production Example 3-5 as a reaction product of PEDOT-PSS and the oxirane group-containing organic compound. A polymer composition (5) was prepared to produce a capacitor. For the obtained capacitor, the capacitance at 120 Hz, the initial value of ESR at 100 kHz, and the rate of change of ESR were measured in the same manner as in Example 1. As shown in Table 1, the measurement results are as follows: ESR initial value (mΩ) = 20.8, capacitance (μF) = 32.9, ESR change rate 1 (%) = 7.4, ESR change rate 2 ( %) = 8.

(Example 6)
100 g of the reaction product (C-2) of PEDOT-PSS and glycidol obtained from Production Example 3-2 was used as a reaction product of PEDOT-PSS and an oxirane group-containing organic compound, and polyglycerol (Sakamoto Pharmaceutical Co., Ltd.) was used instead of PEG400. A conductive polymer composition (6) was prepared in accordance with Example 1 except that 5 g of polyglycerin # 300 (manufactured by the company) was used, and a capacitor was produced. For the obtained capacitor, the capacitance at 120 Hz, the initial value of ESR at 100 kHz, and the rate of change of ESR were measured in the same manner as in Example 1. As shown in Table 1, the measurement results are as follows: ESR initial value (mΩ) = 20.4, capacitance (μF) = 33.4, ESR change rate 1 (%) = 7.6, ESR change rate 2 ( %) = 8.

(Example 7)
100 g of the reaction product (C-2) of PEDOT-PSS and glycidol obtained from Production Example 3-2 was used as a reaction product of PEDOT-PSS and an oxirane group-containing organic compound, and polyglycerol (Sakamoto Pharmaceutical Co., Ltd.) was used instead of PEG400. A conductive polymer composition (7) was prepared in the same manner as in Example 1 except that 10 g of polyglycerin # 300 (manufactured by the company) was used, and a capacitor was produced. For the obtained capacitor, the capacitance at 120 Hz, the initial value of ESR at 100 kHz, and the rate of change of ESR were measured in the same manner as in Example 1. As shown in Table 1, the measurement results are as follows: ESR initial value (mΩ) = 19.6, capacitance (μF) = 32.6, ESR change rate 1 (%) = 0.3, ESR change rate 2 ( %) = 10.

(Example 8)
As a reaction product of PEDOT-PSS and an oxirane group-containing organic compound, 100 g of the reaction product (C-2) of PEDOT-PSS and glycidol obtained in Production Example 3-2 was used, and 5 g of erythritol was used instead of pentaerythritol. Others prepared the conductive polymer composition (8) according to Example 1, and produced the capacitor. For the obtained capacitor, the capacitance at 120 Hz, the initial value of ESR at 100 kHz, and the rate of change of ESR were measured in the same manner as in Example 1. As shown in Table 1, the measurement results are as follows: ESR initial value (mΩ) = 21.2, capacitance (μF) = 32.6, ESR change rate 1 (%) = 8.2, ESR change rate 2 ( %) = 10.

Example 9
Other than using PEDOT-PSS and glycidol reaction product (C-2) 100 g obtained from Production Example 3-2 as a reaction product of PEDOT-PSS and oxirane group-containing organic compound, pentaerythritol was 0.2 g. Prepared a conductive polymer composition (9) according to Example 1 to produce a capacitor. For the obtained capacitor, the capacitance at 120 Hz, the initial value of ESR at 100 kHz, and the rate of change of ESR were measured in the same manner as in Example 1. As shown in Table 1, the measurement results are as follows: ESR initial value (mΩ) = 19.7, capacitance (μF) = 33.0, ESR change rate 1 (%) = 10, ESR change rate 2 (%) = 12.

(Example 10)
A reaction product of PEDOT-PSS and glycidol obtained in Production Example 3-2 (C-2) 100 g was used as a reaction product of PEDOT-PSS and an oxirane group-containing organic compound, and pentaerythritol was changed to 0.8 g. A conductive polymer composition (10) was prepared in accordance with Example 1 to produce a capacitor. For the obtained capacitor, the capacitance at 120 Hz, the initial value of ESR at 100 kHz, and the rate of change of ESR were measured in the same manner as in Example 1. As shown in Table 1, the measurement results are as follows: ESR initial value (mΩ) = 19.7, capacitance (μF) = 33.7, ESR change rate 1 (%) = 0.5, ESR change rate 2 ( %) = 8.

(Example 11)
The reaction was performed except that 100 g of the reaction product (C-2) of PEDOT-PSS and glycidol obtained in Production Example 3-2 was used as the reaction product of PEDOT-PSS and the oxirane group-containing organic compound, and pentaerythritol was changed to 3 g. A conductive polymer composition (11) was prepared according to Example 1 to produce a capacitor. For the obtained capacitor, the capacitance at 120 Hz, the initial value of ESR at 100 kHz, and the rate of change of ESR were measured in the same manner as in Example 1. As shown in Table 1, the measurement results are as follows: ESR initial value (mΩ) = 20.0, capacitance (μF) = 32.0, ESR change rate 1 (%) = 0.6, ESR change rate 2 ( %) = 10.

(Example 12)
A reaction product of PEDOT-PSS and oxirane group-containing organic compound was used as a reaction product of PEDOT-PSS and glycidol (C-2) obtained in Production Example 3-2, and dimethyl sulfoxide was changed to 5 g of γ-butyrolactone. A conductive polymer composition (12) was prepared according to Example 1, and a capacitor was produced. For the obtained capacitor, the capacitance at 120 Hz, the initial value of ESR at 100 kHz, and the rate of change of ESR were measured in the same manner as in Example 1. As shown in Table 1, the measurement results are as follows: ESR initial value (mΩ) = 19.6, capacitance (μF) = 33.0, ESR change rate 1 (%) = 5.7, ESR change rate 2 ( %) = 5.

(Example 13)
The reaction product of PEDOT-PSS and glycidol obtained from Production Example 3-2 (C-2) 100 g as a reaction product of PEDOT-PSS and the oxirane group-containing organic compound, except that pyrogallol was 0.1 g, A conductive polymer composition (13) was prepared according to Example 1 to produce a capacitor. For the obtained capacitor, the capacitance at 120 Hz, the initial value of ESR at 100 kHz, and the rate of change of ESR were measured in the same manner as in Example 1. As shown in Table 1, the measurement results are as follows: ESR initial value (mΩ) = 20.1, capacitance (μF) = 31.9, ESR change rate 1 (%) = 8.0, ESR change rate 2 ( %) = 15.

(Example 14)
The reaction product of PEDOT-PSS and glycidol obtained from Production Example 3-2 (C-2) 100 g as a reaction product of PEDOT-PSS and the oxirane group-containing organic compound, except that pyrogallol was 1.2 g, A conductive polymer composition (14) was prepared according to Example 1 to produce a capacitor. For the obtained capacitor, the capacitance at 120 Hz, the initial value of ESR at 100 kHz, and the rate of change of ESR were measured in the same manner as in Example 1. As shown in Table 1, the measurement results are as follows: ESR initial value (mΩ) = 20.9, capacitance (μF) = 33.1, ESR change rate 1 (%) = 0.0, ESR change rate 2 ( %) = 5.

(Comparative Example 1)
Other than using 100 g of the reaction product (C-6) of PEDOT-PSS and lauryl alcohol (EO) 15 glycidyl ether obtained from Production Example 3-6 as a reaction product of PEDOT-PSS and the oxirane group-containing organic compound, A conductive polymer composition (15) was prepared according to Example 1 to produce a capacitor. For the obtained capacitor, the capacitance at 120 Hz, the initial value of ESR at 100 kHz, and the rate of change of ESR were measured in the same manner as in Example 1. As shown in Table 1, the measurement results are as follows: ESR initial value (mΩ) = 35.7, capacitance (μF) = 30.2, ESR change rate 1 (%) = 46, ESR change rate 2 (%) = 120.

(Comparative Example 2)
Example 1 except that 100 g of the reaction product (C-7) of PEDOT-PSS and 2-ethylhexyl glycidyl ether obtained from Production Example 3-7 was used as the reaction product of PEDOT-PSS and the oxirane group-containing organic compound. In accordance with the above, a conductive polymer composition (16) was prepared to produce a capacitor. For the obtained capacitor, the capacitance at 120 Hz, the initial value of ESR at 100 kHz, and the rate of change of ESR were measured in the same manner as in Example 1. As shown in Table 1, the measurement results are as follows: ESR initial value (mΩ) = 223.0, capacitance (μF) = 19.3, ESR change rate 1 (%) = 84, ESR change rate 2 (%) = 55.

(Comparative Example 3)
A conductive polymer according to Example 1 except that the 1.6 mass% PEDOT-PSS aqueous dispersion prepared in Production Example 2 was used instead of the reaction product of PEDOT-PSS and the oxirane group-containing organic compound. A composition (17) was prepared to produce a capacitor. For the obtained capacitor, the capacitance at 120 Hz, the initial value of ESR at 100 kHz, and the rate of change of ESR were measured in the same manner as in Example 1. As shown in Table 1, the measurement results are as follows: ESR initial value (mΩ) = 276.0, capacitance (μF) = 15.9, ESR change rate 1 (%) = 90, ESR change rate 2 (%) = 67.

(Comparative Example 4)
A conductive polymer composition according to Example 1 except that the reaction product (C-8) of PEDOT-PSS and glycidol obtained from Production Example 3-8 was used as the PEDOT-PSS and oxirane group-containing organic compound. (18) was prepared to produce a capacitor. For the obtained capacitor, the capacitance at 120 Hz, the initial value of ESR at 100 kHz, and the rate of change of ESR were measured in the same manner as in Example 1. As shown in Table 1, the measurement results are as follows: ESR initial value (mΩ) = 276.0, capacitance (μF) = 19.4, ESR change rate 1 (%) = 90, ESR change rate 2 (%) = 67.

In Table 1, the unit of the numerical value in the column of each component is gram. Moreover, the unit of the numerical value indicating performance is a unit in each item. The present invention provides a capacitor having a large capacitance, low ESR, and excellent long-term reliability, and a method for manufacturing the same. As shown in Examples 1 to 14, the capacitor according to the present invention was shown to have a large capacitance and low ESR, a small change rate of ESR after the heat resistance test, that is, excellent long-term reliability. Although the response rate of the capacitor of Comparative Example 1 was as high as 58%, the residual rate was high, and as a result, the ESR increased and the rate of change of ESR also increased. Further, the capacitor of Comparative Example 2 had a low reaction rate of 4% and a high residual rate, so that the capacitance was very small, the ESR was high, and the rate of change of ESR was also very large. In addition, although the capacitor of Comparative Example 4 had a low residual rate, the reaction rate was low, so the capacitance was very small, the ESR was high, and the rate of change of ESR was also very large.

Claims (8)

An anode made of a porous body of valve metal, a dielectric layer formed by oxidizing the anode surface, a cathode made of a conductive material provided on the opposite side of the anode in the dielectric layer, and the dielectric layer and the cathode In a capacitor comprising a solid electrolyte layer formed therebetween,
The solid electrolyte layer includes a π-conjugated conductive polymer (a) and a polyanion (b) doped with the π-conjugated conductive polymer, and an anion and an oxirane group or oxetane group-containing organic other than those required for doping in the polyanion. Comprising a reaction product with compound (c),
In the formation conditions of the solid electrolyte layer, unreacted oxirane group or oxetane group-containing organic compound (c) and its ring-opening compound were doped into π-conjugated conductive polymer (a) and π-conjugated conductive polymer The mass ratio with respect to the total with the polyanion (b) is 110% or less,
A capacitor obtained by reacting 50 mol% or more of an anion other than that required for doping in a polyanion with an organic compound (c) containing an oxirane group or an oxetane group.   The capacitor according to claim 1, wherein the solid electrolyte layer further contains a hydroxy group-containing aromatic compound.   The capacitor according to claim 1, wherein the solid electrolyte layer further contains a water-soluble polymer compound or a water-dispersible polymer compound.   The capacitor according to claim 1, wherein the solid electrolyte layer further contains a sulfo group-containing dicarboxylic acid.   The capacitor according to claim 1, wherein the solid electrolyte layer further contains an aliphatic compound having four or more hydroxyl groups in the molecule. π-conjugated conductive polymer (a), polyanion (b) doped in π-conjugated conductive polymer, anion and oxirane group or oxetane group-containing organic compound (c) other than that required for doping in the polyanion A step of preparing a conductive polymer dispersion containing a reaction product with
Oxidizing the surface of the anode made of a porous body of valve metal to form a dielectric layer;
Forming a cathode at a position facing the dielectric layer;
Applying the conductive polymer dispersion on the surface of the dielectric layer and drying to form a solid electrolyte layer;
Have
Under the conditions for forming the solid electrolyte layer, the unreacted oxirane group or oxetane group-containing organic compound (c) in the solid electrolyte layer and the ring-opening compound thereof are π-conjugated conductive polymer (a) and π-conjugated conductive properties. The mass ratio with respect to the sum total with the polyanion (b) doped in the polymer is 110% or less,
A method for producing a capacitor, wherein 50 mol% or more of anions other than those required for doping in a polyanion in a conductive polymer dispersion are reacted with an oxirane group or oxetane group-containing organic compound (c).   The oxirane group or oxetane group-containing organic compound (c) is added to an aqueous dispersion of a polyanion (b) doped with a π-conjugated conductive polymer (a) and a π-conjugated conductive polymer, and the polyanion (b) The method for producing a capacitor according to claim 6, wherein the capacitor undergoes a step of reacting with an oxirane group- or oxetane group-containing organic compound (c). The method for producing a capacitor according to claim 6, wherein the conductive polymer dispersion contains a high boiling point solvent.