JP2012099868A - Capacitor and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a capacitor having a low ESR and a high withstand voltage.SOLUTION: A capacitor 10 comprises: a positive electrode 11 composed of a porous body of valve metal; a dielectric layer 12 formed through surface oxidation of the positive electrode 11; and a solid electrolytic layer 13 formed on a surface side of the dielectric layer 12. The solid electrolytic layer 13 contains a π conjugated system conductive polymer, a compound having a sulfonic acid group, and a water soluble compound or a water dispersion compound other than the compound having the sulfonic acid group.

Description

  The present invention relates to a capacitor such as an aluminum electrolytic capacitor, a tantalum electrolytic capacitor, a niobium electrolytic 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. 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.
As shown in Patent Document 1, this capacitor has 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 carbon layer. And a cathode having a silver layer or the like laminated thereon. As the solid electrolyte layer, a conductive film containing a π-conjugated conductive polymer may be used.

As a method for forming a conductive film containing a π-conjugated conductive polymer, an electrolytic layer in which a conductive layer made of manganese oxide is formed in advance on the surface of the porous body of the valve metal, and then this is used as an electrode for polymerization. A chemical method (see Patent Document 3) in which a legal method (see Patent Document 2) and a precursor monomer constituting a π-conjugated conductive polymer using an oxidizing agent are polymerized are widely known.
As a method for forming a conductive film other than the electrolytic polymerization method and the chemical oxidative polymerization method, for example, in Patent Document 4, aniline is chemically oxidatively polymerized and water-soluble while coexisting with a polyanion having a sulfonic acid group, a carboxylic acid group or the like There has been proposed a method of preparing a polyaniline, applying the polyaniline aqueous solution, and drying to form a coating film. In this method, it is said that a highly conductive film can be easily formed.

JP 2003-37024 A JP-A-63-158829 JP 63-173313 A JP-A-7-105718

However, when the method for forming a conductive film described in Patent Documents 2 to 4 is applied when forming the solid electrolyte layer of the capacitor, there arises a problem that the withstand voltage of the capacitor is lowered. In addition, the electrolytic polymerization method described in Patent Document 2 is complicated because the conductive layer made of manganese oxide is formed, and the manganese oxide has low conductivity, so that the highly conductive π-conjugated conductivity is high. There was a problem that the effect of using a polymer was weakened.
In the chemical oxidative polymerization method described in Patent Document 3, the conductivity is lower than that of electrolytic polymerization. If the conductivity of the capacitor is low, there arises a problem that the equivalent series resistance (hereinafter, equivalent series resistance is referred to as ESR) increases.
An object of the present invention is to provide a capacitor with low ESR and high withstand voltage. It is another object of the present invention to provide a capacitor manufacturing method that can easily manufacture a capacitor having a low ESR and a high withstand voltage.

[1] In a capacitor comprising an anode made of a porous body of valve metal, a dielectric layer formed by oxidizing the anode surface, and a solid electrolyte layer formed on the dielectric layer surface side,
A capacitor, wherein the solid electrolyte layer contains a π-conjugated conductive polymer, a compound having a sulfonic acid group, and a water-soluble compound or a water-dispersible compound other than the compound having the sulfonic acid group.
[2] The capacitor according to [1], wherein the water-soluble compound is a water-soluble polymer compound.
[3] The capacitor according to [1] or [2], wherein the solid electrolyte layer further contains an alkaline compound.
[4] A precursor monomer of a π-conjugated conductive polymer, a compound having a sulfonic acid group, and the sulfonic acid group are formed on the surface of a dielectric layer formed by oxidizing the surface of an anode made of a porous body of valve metal. Attaching a conductive polymer raw material solution containing a water-soluble compound or a water-dispersible compound other than the compound having a solvent and a solvent;
And a step of polymerizing a precursor monomer of a π-conjugated conductive polymer in a conductive polymer raw material solution adhered to the surface of the dielectric layer.
[5] On the surface of the dielectric layer formed by oxidizing the surface of the anode made of a valve metal porous body, a π-conjugated conductive polymer, a polymer having a sulfonic acid group, and a polymer having the sulfonic acid group A step of attaching a conductive polymer solution containing a water-soluble compound or a water-dispersible compound and a solvent other than
And a step of drying the conductive polymer solution adhered to the surface of the dielectric layer.
[6] The method for producing a capacitor as described in [5], wherein the pH of the conductive polymer solution at 25 ° C. is 3 to 13.

The capacitor of the present invention has a low ESR and a high withstand voltage.
According to the capacitor manufacturing method of the present invention, a capacitor having a low ESR and a high withstand voltage can be easily manufactured.

It is a cross-sectional schematic diagram which shows one embodiment of the capacitor | condenser of this invention.

"Capacitor"
An embodiment of the capacitor of the present invention will be described.
FIG. 1 shows the configuration of the capacitor of this embodiment. The capacitor 10 of this embodiment includes an anode 11 made of a porous body of valve metal, a dielectric layer 12 formed by oxidizing the surface of the anode 11, and a solid electrolyte layer formed on the surface of the dielectric layer 12. 13 and a cathode 14 are schematically configured.

<Anode>
Examples of the valve metal forming the anode 11 include aluminum, tantalum, niobium, titanium, hafnium, zirconium, zinc, tungsten, bismuth, and antimony. Of these, aluminum, tantalum, and niobium are preferable.
Specific examples of the anode 11 include those obtained by etching an aluminum foil to increase the surface area and then oxidizing the surface, or oxidizing the surface of a sintered body of tantalum particles and niobium particles into pellets. Can be mentioned. The surface of the anode 11 thus oxidized is uneven.

<Dielectric layer>
The dielectric layer 12 is obtained by, for example, forming the surface of the anode 11 by anodic oxidation in an electrolytic solution such as a diammonium adipate aqueous solution. Therefore, as shown in FIG. 1, the dielectric layer 12 is along the uneven surface of the anode 11.

<Solid electrolyte layer>
The solid electrolyte layer 13 is a layer containing a π-conjugated conductive polymer, a compound having a sulfonic acid group, and a water-soluble compound or a water-dispersible compound as essential components. The thickness of the solid electrolyte layer 13 is preferably 1 to 100 μm.

(Π-conjugated conductive polymer)
The π-conjugated conductive polymer can be used as long as the main chain is an organic polymer having a π-conjugated system. Examples thereof 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.
Even if the π-conjugated conductive polymer remains unsubstituted, sufficient conductivity can be obtained. However, in order to further improve conductivity, an alkyl group, a carboxylic acid group, a sulfonic acid group, an alkoxyl group, a hydroxyl group It is preferable to introduce a functional group such as a cyano group into the π-conjugated conductive polymer.

  Specific examples of such π-conjugated conductive polymers include polypyrrole, poly (N-methylpyrrole), poly (3-methylpyrrole), 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), polythiophene, poly (3-methylthiophene), Poly (3-hexylthiophene), poly (3-heptylthiophene), poly (3-octylthiophene), poly (3-de Ruthiophene), poly (3-dodecylthiophene), poly (3-octadecylthiophene), poly (3-bromothiophene), poly (3,4-dimethylthiophene), poly (3,4-dibutylthiophene), poly ( 3-hydroxythiophene), poly (3-methoxythiophene), poly (3-ethoxythiophene), poly (3-butoxythiophene), poly (3-hexyloxythiophene), poly (3-heptyloxythiophene), poly ( 3-octyloxythiophene), poly (3-decyloxythiophene), poly (3-dodecyloxythiophene), poly (3-octadecyloxythiophene), poly (3,4-dihydroxythiophene), poly (3,4 Dimethoxythiophene), poly (3,4-ethylenedioxythiophene) , Poly (3,4-propylenedioxythiophene), poly (3,4-butenedioxythiophene), 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 them, from one or two kinds selected from polypyrrole, polythiophene, poly (N-methylpyrrole), poly (3-methylthiophene), poly (3-methoxythiophene), and poly (3,4-ethylenedioxythiophene). The (co) polymer is preferably used from the viewpoints of resistance and reactivity. Furthermore, polypyrrole and poly (3,4-ethylenedioxythiophene) are more preferable from the viewpoint of higher conductivity and improved heat resistance.

(Compound having a sulfonic acid group)
The compound having a sulfonic acid group serves as a dopant for the π-conjugated conductive polymer.
The compound having a sulfonic acid group may be a single molecule having a sulfonic acid group or a polymer having a sulfonic acid group.
Monomolecules having sulfonic acid groups include alkylbenzene sulfonic acid, alkyl naphthalene sulfonic acid, alkyl naphthalene disulfonic acid, naphthalene sulfonic acid formalin polycondensate, melamine sulfonic acid formalin polycondensate, naphthalene disulfonic acid, naphthalene trisulfonic acid, di Examples thereof include organic sulfonic acid compounds such as naphthylmethane disulfonic acid, anthraquinone sulfonic acid, anthraquinone disulfonic acid, anthracene sulfonic acid, and pyrene sulfonic acid.

The polymer having a sulfonic acid group is selected from substituted or unsubstituted polyalkylene, substituted or unsubstituted polyalkenylene, substituted or unsubstituted polyimide, substituted or unsubstituted polyamide, substituted or unsubstituted polyester A polymer or copolymer having a structural unit having a sulfonic acid group.
Note that the polymer having a sulfonic acid group not only solubilizes the π-conjugated conductive polymer in a solvent, but also functions as a dopant for the π-conjugated conductive polymer.

  Here, polyalkylene is a polymer whose main chain is composed of repeating methylene. For example, polyethylene, polypropylene, polybutene, polypentene, polyhexene, polyvinyl alcohol, polyvinylphenol, poly (3,3,3-trifluoropropylene), polyacrylonitrile, polyacrylate, polystyrene and the like can be mentioned.

Polyalkenylene is a polymer composed of structural units containing one or more unsaturated bonds (vinyl groups) in the main chain. Among these, substituted or unsubstituted butenylene is preferable because of the interaction between the unsaturated bond and the π-conjugated conductive polymer and the ease of synthesis using substituted or unsubstituted butadiene as a starting material.
Specific examples of polyalkenylene include propenylene, 1-methylpropenylene, 1-butylpropenylene, 1-decylpropenylene, 1-cyanopropenylene, 1-phenylpropenylene, 1-hydroxypropenylene, 1-butenylene, 1-methyl-1-butenylene, 1-ethyl-1-butenylene, 1-octyl-1-butenylene, 1-pentadecyl-1-butenylene, 2-methyl-1-butenylene, 2-ethyl-1-butenylene, 2- Butyl-1-butenylene, 2-hexyl-1-butenylene, 2-octyl-1-butenylene, 2-decyl-1-butenylene, 2-dodecyl-1-butenylene, 2-phenyl-1-butenylene, 2-butenylene, 1-methyl-2-butenylene, 1-ethyl-2-butenylene, 1-octyl-2-butenylene 1-pentadecyl-2-butenylene, 2-methyl-2-butenylene, 2-ethyl-2-butenylene, 2-butyl-2-butenylene, 2-hexyl-2-butenylene, 2-octyl-2-butenylene, 2- Decyl-2-butenylene, 2-dodecyl-2-butenylene, 2-phenyl-2-butenylene, 2-propylenephenyl-2-butenylene, 3-methyl-2-butenylene, 3-ethyl-2-butenylene, 3-butyl 2-butenylene, 3-hexyl-2-butenylene, 3-octyl-2-butenylene, 3-decyl-2-butenylene, 3-dodecyl-2-butenylene, 3-phenyl-2-butenylene, 3-propylenephenyl- 2-butenylene, 2-pentenylene, 4-propyl-2-pentenylene, 4-butyl-2-pentenylene, 4-he Selected from sil-2-pentenylene, 4-cyano-2-pentenylene, 3-methyl-2-pentenylene, 4-ethyl-2-pentenylene, 3-phenyl-2-pentenylene, 4-hydroxy-2-pentenylene, hexenylene, etc. And polymers containing one or more structural units.

As polyimide, pyromellitic dianhydride, biphenyltetracarboxylic dianhydride, benzophenonetetracarboxylic dianhydride, 2,2 ′, 3,3′-tetracarboxydiphenyl ether dianhydride, 2,2 ′-[ Examples include polyimides from anhydrides such as 4,4′-di (dicarboxyphenyloxy) phenyl] propane dianhydride and diamines such as oxydiamine, paraphenylenediamine, metaphenylenediamine, and benzophenonediamine.
Examples of the polyamide include polyamide 6, polyamide 6,6, polyamide 6,10 and the like.
Examples of the polyester include polyethylene terephthalate and polybutylene terephthalate.

When the polymer having a sulfonic acid group has other substituents, the substituents include alkyl groups, hydroxyl groups, amino groups, cyano groups, phenyl groups, phenol groups, alkoxyl groups, carbonyl groups, oxycarbonyl groups, etc. Is mentioned. In view of solubility in a solvent, heat resistance, compatibility with a resin, and the like, an alkyl group, a hydroxyl group, a phenol group, and an oxycarbonyl group are preferable.
Alkyl groups can increase solubility and dispersibility in polar or nonpolar solvents, compatibility and dispersibility in resins, etc., and hydroxyl groups form hydrogen bonds with other hydrogen atoms and the like. It can be made easy and the solubility in an organic solvent, the compatibility with a resin, the dispersibility, and the adhesiveness can be increased. In addition, the cyano group and the hydroxyphenyl group can increase the compatibility and solubility in the polar resin, and can also increase the heat resistance.
Among the above substituents, an alkyl group, a hydroxyl group, an oxycarbonyl group, and a cyano group are preferable.

Examples of the alkyl group include chain alkyl groups such as methyl, ethyl, propyl, butyl, isobutyl, t-butyl, pentyl, hexyl, octyl, decyl, and dodecyl, and cycloalkyl groups such as cyclopropyl, cyclopentyl, and cyclohexyl. . In consideration of solubility in an organic solvent, dispersibility in a resin, steric hindrance, and the like, an alkyl group having 1 to 12 carbon atoms is more preferable.
Examples of the hydroxyl group include a hydroxyl group directly bonded to the main chain of the polymer having a sulfonic acid group or a hydroxyl group bonded via another functional group. Examples of other functional groups include an alkyl group having 1 to 7 carbon atoms, an alkenyl group having 2 to 7 carbon atoms, an amide group, and an imide group. Hydroxyl groups are substituted at the ends or in these functional groups. In these, the hydroxyl group couple | bonded with the terminal of the C1-C6 alkyl group couple | bonded with the principal chain is more preferable from the compatibility to resin and the solubility to an organic solvent.
Examples of the oxycarbonyl group include an alkyloxycarbonyl group directly bonded to the main chain of the polymer having a sulfonic acid group, an aryloxycarbonyl group, an alkyloxycarbonyl group or an aryloxycarbonyl group having another functional group interposed therebetween. Can be mentioned.
Examples of the cyano group include a cyano group directly bonded to the main chain of the polymer having a sulfonic acid group, and a cyano bonded to the terminal of an alkyl group having 1 to 7 carbon atoms bonded to the main chain of the polymer having a sulfonic acid group. And a cyano group bonded to the terminal of an alkenyl group having 2 to 7 carbon atoms bonded to the main chain of the polymer having a sulfonic acid group.

  The degree of polymerization of the polymer having a sulfonic acid group is preferably in the range of 10 to 100,000 monomer units, and more preferably in the range of 50 to 10,000 from the viewpoint of conductivity.

Specific examples of the polymer having a sulfonic acid group include polyvinyl sulfonic acid, polystyrene sulfonic acid, polyallyl sulfonic acid, polyacrylic acid ethyl sulfonic acid, polyacrylic acid butyl sulfonic acid, poly (2-acrylamido-2-methylpropane). Sulfonic acid), polyisoprene sulfonic acid, and the like. These homopolymers may be sufficient and 2 or more types of copolymers may be sufficient.
Among these, polystyrene sulfonic acid, polyisoprene sulfonic acid, polyacrylic acid ethyl sulfonic acid, and polyacrylic acid butyl sulfonic acid are preferable. These polymers can mitigate thermal decomposition of the π-conjugated conductive polymer.
The degree of polymerization of the polymer having a sulfonic acid group is preferably in the range of 10 to 100,000 monomer units, and more preferably in the range of 50 to 10,000 from the viewpoint of solvent solubility and conductivity. preferable.

  The ratio of the π-conjugated conductive polymer and the compound having a sulfonic acid group in the solid electrolyte layer 13 is 1 to 1,000 π-conjugated conductive polymer with respect to 100 parts by mass of the compound having a sulfonic acid group. It is preferable that it is a mass part. When the π-conjugated conductive polymer is less than 1 part by mass, the conductivity tends to be insufficient, and when it exceeds 1,000 parts by mass, the solvent solubility tends to be insufficient.

(Water-soluble compounds)
The water-soluble compound is a compound that is liquid or solid at room temperature and normal pressure and is soluble in 0.5 g or more in 100 g of water, and is a compound other than the compound having a sulfonic acid group described in paragraph 0014. . Examples of the water-soluble compound include a compound having a hydrophilic group containing atoms such as oxygen, nitrogen, and sulfur that interact strongly with water. Examples of the hydrophilic group include —CO—, —COOM, —CONR—, —OH, —NR ₂ , —O—, —SO ₃ M, and a salt containing these groups (R is a hydrogen atom or An organic group, M is a hydrogen atom, an alkali metal, an alkaline earth metal, a quaternary amine, etc.); However, the compound having —SO ₃ M used as the water-soluble compound is different from that added as a dopant of the π-conjugated conductive polymer.
The water-soluble compound may be either a water-soluble monomolecular compound or a water-soluble polymer compound.

[Water-soluble monomolecular compound]
Examples of the water-soluble monomolecular compound include a nitrogen-containing aromatic cyclic compound, a compound having two or more hydroxyl groups, a compound having two or more carboxyl groups, one or more hydroxyl groups, and one or more Examples thereof include a compound having a carboxyl group, a compound having an amide group, a compound having an imide group, a lactam compound, a compound having a glycidyl group, a silane coupling agent, an acrylic compound, and a water-soluble organic solvent.

-Nitrogen-containing aromatic cyclic compound A nitrogen-containing aromatic cyclic compound has an aromatic ring containing at least one nitrogen atom, and the nitrogen atom in the aromatic ring is in the aromatic ring. It has a conjugated relationship with other atoms. In order to become a conjugated relationship, the nitrogen atom and other atoms form an unsaturated bond. Alternatively, even if the nitrogen atom does not directly form an unsaturated bond with another atom, it may be adjacent to the other atom that forms the unsaturated bond. This is because an unshared electron pair existing on a nitrogen atom can form a pseudo conjugate relationship with an unsaturated bond formed between other atoms.
The nitrogen-containing aromatic cyclic compound preferably has both a nitrogen atom having a conjugated relationship with another atom and a nitrogen atom adjacent to the other atom forming the unsaturated bond.

Examples of such nitrogen-containing aromatic cyclic compounds include pyridines and derivatives thereof containing one nitrogen atom, imidazoles and derivatives thereof containing two nitrogen atoms, pyrimidines and derivatives thereof, and pyrazines. And derivatives thereof, triazines containing three nitrogen atoms, and derivatives thereof. From the viewpoint of solvent solubility and the like, pyridines and derivatives thereof, imidazoles and derivatives thereof, and pyrimidines and derivatives thereof are preferable.
Nitrogen-containing aromatic cyclic compounds are those in which substituents such as alkyl groups, hydroxyl groups, carboxyl groups, cyano groups, phenyl groups, phenol groups, oxycarbonyl groups, alkoxyl groups, and carbonyl groups are introduced into the ring. However, it may be not introduced. The ring may be polycyclic.

  Specific examples of pyridines and derivatives thereof include pyridine, 2-methylpyridine, 3-methylpyridine, 4-methylpyridine, 4-ethylpyridine, N-vinylpyridine, 2,4-dimethylpyridine, 2,4. , 6-trimethylpyridine, 3-cyano-5-methylpyridine, 2-pyridinecarboxylic acid, 6-methyl-2-pyridinecarboxylic acid, 4-pyridinecarboxaldehyde, 4-aminopyridine, 2,3-diaminopyridine, 2 , 6-diaminopyridine, 2,6-diamino-4-methylpyridine, 4-hydroxypyridine, 4-pyridinemethanol, 2,6-dihydroxypyridine, 2,6-pyridinedimethanol, methyl 6-hydroxynicotinate, 2 -Hydroxy-5-pyridinemethanol, ethyl 6-hydroxynicotinate, 4-pi Lysine methanol, 4-pyridineethanol, 2-phenylpyridine, 3-methylquinoline, 3-ethylquinoline, quinolinol, 2,3-cyclopentenopyridine, 2,3-cyclohexanopyridine, 1,2-di (4- Pyridyl) ethane, 1,2-di (4-pyridyl) propane, 2-pyridinecarboxaldehyde, 2-pyridinecarboxylic acid, 2-pyridinecarbonitrile, 2,3-pyridinedicarboxylic acid, 2,4-pyridinedicarboxylic acid, Examples include 2,5-pyridinedicarboxylic acid, 2,6-pyridinedicarboxylic acid, and 3-pyridinesulfonic acid.

  Specific examples of imidazoles and derivatives thereof include imidazole, 2-methylimidazole, 2-propylimidazole, 2-undecylimidazole, 2-phenylimidazole, N-methylimidazole, N-vinylimidazole, and N-allylimidazole. 1- (2-hydroxyethyl) imidazole (N-hydroxyethylimidazole), 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenyl Imidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 1-acetylimidazole, 4,5-imidazoledicarbo Acid, dimethyl 4,5-imidazole dicarboxylate, benzimidazole, 2-aminobenzimidazole, 2-aminobenzimidazole-2-sulfonic acid, 2-amino-1-methylbenzimidazole, 2-hydroxybenzimidazole , 2- (2-pyridyl) benzimidazole and the like.

  Specific examples of pyrimidines and derivatives thereof include 2-amino-4-chloro-6-methylpyrimidine, 2-amino-6-chloro-4-methoxypyrimidine, 2-amino-4,6-dichloropyrimidine, 2-amino-4,6-dihydroxypyrimidine, 2-amino-4,6-dimethylpyrimidine, 2-amino-4,6-dimethoxypyrimidine, 2-aminopyrimidine, 2-amino-4-methylpyrimidine, 4,6 -Dihydroxypyrimidine, 2,4-dihydroxypyrimidine-5-carboxylic acid, 2,4,6-triaminopyrimidine, 2,4-dimethoxypyrimidine, 2,4,5-trihydroxypyrimidine, 2,4-pyrimidinediol, etc. Is mentioned.

  Specific examples of the pyrazines and derivatives thereof include pyrazine, 2-methylpyrazine, 2,5-dimethylpyrazine, pyrazinecarboxylic acid, 2,3-pyrazinedicarboxylic acid, 5-methylpyrazinecarboxylic acid, pyrazineamide, 5 -Methylpyrazineamide, 2-cyanopyrazine, aminopyrazine, 3-aminopyrazine-2-carboxylic acid, 2-ethyl-3-methylpyrazine, 2-ethyl-3-methylpyrazine, 2,3-dimethylpyrazine, 2, Examples include 3-diethylpyrazine.

  Specific examples of triazines and derivatives thereof include 1,3,5-triazine, 2-amino-1,3,5-triazine, 3-amino-1,2,4-triazine, and 2,4-diamino. -6-phenyl-1,3,5-triazine, 2,4,6-triamino-1,3,5-triazine, 2,4,6-tris (trifluoromethyl) -1,3,5-triazine, 2,4,6-tri-2-pyridine-1,3,5-triazine, 3- (2-pyridine) -5,6-bis (4-phenylsulfonic acid) -1,2,4-triazine disodium 3- (2-pyridine) -5,6-diphenyl-1,2,4-triazine, 3- (2-pyridine) -5,6-diphenyl-1,2,4-triazine-ρ, ρ′- Disodium disulphonate, 2-hydroxy-4,6-dichloro -1,3,5-triazine and the like.

Since a non-shared electron pair exists in the nitrogen atom in the nitrogen-containing aromatic cyclic compound, a substituent or a proton is easily coordinated or bonded on the nitrogen atom. When a substituent or proton is coordinated or bonded to a nitrogen atom, it tends to have a cationic charge on the nitrogen atom. Here, since the nitrogen atom and other atoms have a conjugated relationship, the cation charge generated by the coordination or bonding of a substituent or a proton on the nitrogen atom is contained in the nitrogen-containing aromatic ring. Once diffused, it will exist in a stable form.
For this reason, in the nitrogen-containing aromatic cyclic compound, a substituent may be introduced into the nitrogen atom to form a nitrogen-containing aromatic cyclic compound cation. Further, a salt may be formed by combining the cation and the anion. Even if it is a salt, the same effect as a nitrogen-containing aromatic cyclic compound which is not a cation is exhibited.
Examples of the substituent introduced into the nitrogen atom of the nitrogen-containing aromatic cyclic compound include a hydrogen atom, an alkyl group, a hydroxyl group, a carboxyl group, a cyano group, a phenyl group, a phenol group, an oxycarbonyl group, an alkoxyl group, and a carbonyl group. Etc. As the kind of the substituent, the substituent shown above can be introduced.

  The content of the nitrogen-containing aromatic cyclic compound is preferably in the range of 0.1 to 100 mol, more preferably in the range of 0.5 to 30 mol, with respect to 1 mol of the anion group unit of the polyanion. The range of 1 to 10 mol is particularly preferable from the viewpoint of the physical properties and conductivity of the solid electrolyte layer 13. When the content of the nitrogen-containing aromatic cyclic compound is less than 0.1 mol, the interaction between the nitrogen-containing aromatic cyclic compound, the polyanion and the conjugated conductive polymer tends to be weak, and the conductivity May be insufficient. In addition, when the nitrogen-containing aromatic cyclic compound exceeds 100 moles, the content of the conjugated conductive polymer decreases, and it is difficult to obtain sufficient conductivity, and the physical properties of the solid electrolyte layer 13 change. There are things to do.

-Compound having two or more hydroxyl groups Examples of the compound having two or more hydroxyl groups include propylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, glycerin, diglycerin, D-glucose, D-glucitol, isoprene glycol, dimethylolpropionic acid, butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, neopentyl glycol, trimethylolethane, trimethylolpropane, pentaerythritol Polyhydric aliphatic alcohols such as dipentaerythritol, thiodiethanol, glucose, tartaric acid, D-glucaric acid, glutaconic acid;
Polymer alcohols such as polyvinyl alcohol, cellulose, polysaccharides, sugar alcohols;
1,4-dihydroxybenzene, 1,3-dihydroxybenzene, 2,3-dihydroxy-1-pentadecylbenzene, 2,4-dihydroxyacetophenone, 2,5-dihydroxyacetophenone, 2,4-dihydroxybenzophenone, 2,6 -Dihydroxybenzophenone, 3,4-dihydroxybenzophenone, 3,5-dihydroxybenzophenone, 2,4'-dihydroxydiphenylsulfone, 2,2 ', 5,5'-tetrahydroxydiphenylsulfone, 3,3', 5,5 '-Tetramethyl-4,4'-dihydroxydiphenylsulfone, hydroxyquinonecarboxylic acid and its salts, 2,3-dihydroxybenzoic acid, 2,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, 2,6- Dihydroxybenzoic acid, 3,5-di Droxybenzoic 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-dihydroxy Naphthoic acid, 1,4-dihydroxy-2-naphthoic acid phenyl ester, 4,5-dihydroxynaphthalene-2,7-disulfonic acid and its salts, 1,8-dihydroxy-3,6-naphthalenedisulfonic acid and its salts, 6,7-Dihydroxy-2-naphthalenesulfonic acid and its 1,2,3-trihydroxybenzene (pyrogallol), 1,2,4-trihydroxybenzene, 5-methyl-1,2,3-trihydroxybenzene, 5-ethyl-1,2,3-tri Hydroxybenzene, 5-propyl-1,2,3-trihydroxybenzene, trihydroxybenzoic acid, trihydroxyacetophenone, trihydroxybenzophenone, trihydroxybenzaldehyde, trihydroxyanthraquinone, 2,4,6-trihydroxybenzene, tetra Aromatic compounds such as hydroxy-p-benzoquinone, tetrahydroxyanthraquinone, methyl garlic acid (methyl gallate), ethyl garlic acid (ethyl gallate), potassium hydroquinone sulfonate, and the like.

  The content of the compound having two or more hydroxyl groups is preferably in the range of 0.05 to 50 mol and more preferably in the range of 0.3 to 10 mol with respect to 1 mol of the anion group unit of the polyanion. More preferred. When the content of the compound having two or more hydroxyl groups is less than 0.05 mol with respect to 1 mol of the anion group unit of the polyanion, conductivity and heat resistance may be insufficient. In addition, when the content of the compound having two or more hydroxyl groups is more than 50 mol with respect to 1 mol of the anion group unit of the polyanion, the content of the π-conjugated conductive polymer in the solid electrolyte layer 13 is small. Thus, it is difficult to obtain sufficient conductivity, and the physical properties of the solid electrolyte layer 13 may change.

When a compound having two or more hydroxyl groups is included as the conductivity improver, the conductivity of the solid electrolyte layer 13 can be further increased for the following reason.
The π-conjugated conductive polymer in the solid electrolyte layer 13 is in a highly oxidized state, and a part of the π-conjugated conductive polymer is easily oxidized and deteriorated by heat or the like. Therefore, it is considered that radicals are generated and the deterioration proceeds due to radical chains. However, it is presumed that a compound having two or more hydroxyl groups can block the radical chain by radical scavenging of the hydroxyl groups and suppress the progress of deterioration, and as a result, the conductivity becomes higher.

・ Compounds having two or more carboxyl groups As compounds having two or more carboxyl groups, maleic acid, fumaric acid, itaconic acid, citraconic acid, malonic acid, 1,4-butanedicarboxylic acid, succinic acid, tartaric acid, Aliphatic carboxylic acid compounds such as adipic acid, D-glucaric acid, glutaconic acid and citric acid;
Phthalic acid, terephthalic acid, isophthalic acid, tetrahydrophthalic anhydride, 5-sulfoisophthalic acid, 5-hydroxyisophthalic acid, methyltetrahydrophthalic anhydride, 4,4'-oxydiphthalic acid, biphenyltetracarboxylic dianhydride, benzophenone tetra Aromatic carboxylic acid compounds in which at least one carboxyl group is bonded to an aromatic ring, such as carboxylic dianhydride, naphthalene dicarboxylic acid, trimellitic acid, pyromellitic acid; diglycolic acid, oxydibutyric acid Thiodiacetic acid (thiodiacetic acid), thiodibutyric acid, iminodiacetic acid, iminobutyric acid and the like.

  The compound having two or more carboxyl groups is preferably in the range of 0.1 to 30 mol, more preferably in the range of 0.3 to 10 mol, relative to 1 mol of the anion group unit of the polyanion. When the content of the compound having two or more carboxyl groups is less than 0.1 mol relative to 1 mol of the anion group unit of the polyanion, conductivity and heat resistance may be insufficient. In addition, when the content of the compound having two or more carboxyl groups is more than 30 mol with respect to 1 mol of the anion group unit of the polyanion, the content of the π-conjugated conductive polymer in the solid electrolyte layer 13 is decreased. However, it is difficult to obtain sufficient conductivity, and the physical properties of the solid electrolyte layer 13 may change.

・ Compounds having one or more hydroxyl groups and one or more carboxyl groups As compounds having one or more hydroxyl groups and one or more carboxyl groups, tartaric acid, glyceric acid, dimethylolbutanoic acid, dimethylolpropanoic acid , D-glucaric acid, glutaconic acid and the like.

  The content of the compound having one or more hydroxyl groups and one or more carboxyl groups is preferably 1 to 5,000 parts by mass with respect to 100 parts by mass in total of the polyanion and the π-conjugated conductive polymer. 50 to 500 parts by mass is more preferable. When the content of the compound having one or more hydroxyl groups and one or more carboxyl groups is less than 1 part by mass, conductivity and heat resistance may be insufficient. Further, when the content of the compound having one or more hydroxyl groups and one or more carboxyl groups is more than 5,000 parts by mass, the content of the π-conjugated conductive polymer in the solid electrolyte layer 13 is decreased. Again, it is difficult to obtain sufficient conductivity.

Amide Compound A compound having an amide group is a monomolecular compound having an amide bond represented by —CO—NH— (the CO moiety is a double bond) in the molecule. That is, as the amide compound, for example, a compound having functional groups at both ends of the bond, a compound in which a cyclic compound is bonded to one end of the bond, urea and urea derivatives in which the functional groups at both ends are hydrogen Etc.
Specific examples of amide compounds include acetamide, malonamide, succinamide, maleamide, fumaramide, benzamide, naphthamide, phthalamide, isophthalamide, terephthalamide, nicotinamide, isonicotinamide, 2-fluamide, formamide, N-methylformamide, propionamide , Propioluamide, butyramide, isobutylamide, methacrylamide, palmitoamide, stearylamide, oleamide, oxamide, glutaramide, adipamide, cinnamamide, glycolamide, lactamide, glyceramide, tartaramide, citrulamide, glyoxylamide, plubuamide, acetoacetamide, Dimethylacetamide, benzylamide, anthranilamide, ethylenediamine Laacetamide, diacetamide, triacetamide, dibenzamide, tribenzamide, rhodanine, urea, 1-acetyl-2-thiourea, biuret, butylurea, dibutylurea, 1,3-dimethylurea, 1,3-diethylurea and These derivatives are mentioned.

  Moreover, acrylamide can also be used as an amide compound. As acrylamide, N-methylacrylamide, N-methylmethacrylamide, N-ethylacrylamide, N-ethylmethacrylamide, N, N-dimethylacrylamide, N, N-dimethylmethacrylamide, N, N-diethylacrylamide, N, Examples thereof include N-diethyl methacrylamide, 2-hydroxyethyl acrylamide, 2-hydroxyethyl methacrylamide, N-methylol acrylamide, N-methylol methacrylamide and the like.

  The molecular weight of the amide compound is preferably 46 to 10,000, more preferably 46 to 5,000, and particularly preferably 46 to 1,000.

  The content of the amide compound is preferably 1 to 5,000 parts by mass and more preferably 50 to 500 parts by mass with respect to 100 parts by mass in total of the polyanion and the π-conjugated conductive polymer. When the content of the amide compound is less than 1 part by mass, conductivity and heat resistance may be insufficient. On the other hand, when the content of the amide compound exceeds 5,000 parts by mass, the content of the π-conjugated conductive polymer in the solid electrolyte layer 13 decreases, and it is difficult to obtain sufficient conductivity.

-Imide compound As an amide compound, since electroconductivity becomes higher, the monomolecular compound (henceforth an imide compound) which has an imide bond is preferable. Examples of the imide compound include phthalimide and phthalimide derivatives, succinimide and succinimide derivatives, benzimide and benzimide derivatives, maleimide and maleimide derivatives, naphthalimide and naphthalimide derivatives from the skeleton.

Moreover, although an imide compound is classified into an aliphatic imide, an aromatic imide, etc. by the kind of functional group of both terminal, an aliphatic imide is preferable from a soluble viewpoint.
Furthermore, the aliphatic imide compound is classified into a saturated aliphatic imide compound having an unsaturated bond between carbons in the molecule and an unsaturated aliphatic imide compound having an unsaturated bond between carbons in the molecule.
The saturated aliphatic imide compound is a compound represented by R ¹ —CO—NH—CO—R ² , and is a compound in which both R ¹ and R ² are saturated hydrocarbons. Specifically, cyclohexane-1,2-dicarboximide, allantoin, hydantoin, barbituric acid, alloxan, glutarimide, succinimide, 5-butylhydantoic acid, 5,5-dimethylhydantoin, 1-methylhydantoin, 1,5 , 5-trimethylhydantoin, 5-hydantoin acetic acid, N-hydroxy-5-norbornene-2,3-dicarboximide, glutarimide, semicarbazide, α, α-dimethyl-6-methylsuccinimide, bis [2- (succinimideoxy) Carbonyloxy) ethyl] sulfone, α-methyl-α-propylsuccinimide, cyclohexylimide and the like.
The unsaturated aliphatic imide compound is a compound represented by R ¹ —CO—NH—CO—R ² , and one or both of R ¹ and R ² are one or more unsaturated bonds. Specific examples are 1,3-dipropylene urea, maleimide, N-methylmaleimide, N-ethylmaleimide, N-hydroxymaleimide, 1,4-bismaleimide butane, 1,6-bismaleimide hexane, 1,8-bis. Maleimide octane, N-carboxyheptylmaleimide and the like can be mentioned.

  The molecular weight of the imide compound is preferably 60 to 5,000, more preferably 70 to 1,000, and particularly preferably 80 to 500.

  The content of the imide compound is preferably 10 to 10,000 parts by mass, more preferably 50 to 5,000 parts by mass with respect to 100 parts by mass in total of the π-conjugated conductive polymer and the polyanion. . If the addition amount of the amide compound and the imide compound is less than the lower limit, the effect of the addition of the amide compound and the imide compound is lowered, which is not preferable. Moreover, when the said upper limit is exceeded, since the electroconductive fall resulting from the fall of (pi) conjugated system conductive polymer concentration will occur, it is unpreferable.

-Lactam compound A lactam compound is an intramolecular cyclic amide of aminocarboxylic acid, and a part of the ring is -CO-NR- (R is hydrogen or an arbitrary substituent). However, one or more carbon atoms in the ring may be replaced with an unsaturated or heteroatom.
Examples of the lactam compound include pentano-4-lactam, 4-pentanelactam-5-methyl-2-pyrrolidone, 5-methyl-2-pyrrolidinone, hexano-6-lactam, 6-hexane lactam and the like.

  The content of the lactam compound is preferably 10 to 10,000 parts by mass and more preferably 50 to 5,000 parts by mass with respect to 100 parts by mass in total of the π-conjugated conductive polymer and the polyanion. . If the amount of the lactam compound added is less than the lower limit, the effect of the addition of the lactam compound is reduced, which is not preferable. Moreover, when the said upper limit is exceeded, since the electroconductive fall resulting from the fall of (pi) conjugated system conductive polymer concentration will occur, it is unpreferable.

-Compound having glycidyl group Examples of the compound having glycidyl group include ethyl glycidyl ether, butyl glycidyl ether, t-butyl glycidyl ether, allyl glycidyl ether, benzyl glycidyl ether, glycidyl phenyl ether, bisphenol A, diglycidyl ether, acrylic Examples thereof include glycidyl compounds such as acid glycidyl ether and methacrylic acid glycidyl ether.

  The content of the compound having a glycidyl group is preferably 10 to 10,000 parts by mass, and 50 to 5,000 parts by mass with respect to 100 parts by mass in total of the π-conjugated conductive polymer and the polyanion. Is more preferable. When the amount of the compound having a glycidyl group is less than the lower limit, the effect of adding the compound having a glycidyl group is undesirably reduced. Moreover, when the said upper limit is exceeded, since the electroconductive fall resulting from the fall of (pi) conjugated system conductive polymer concentration will occur, it is unpreferable.

Silane coupling agent Specific examples of the silane coupling agent include vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and 3-glycidoxypropyl. Trimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane Lan, N-2- (aminoethyl) -3-aminopropyltriethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane Silane, 3-triethoxysilyl-N- (1,3-dimethylethyl-butylidene) propylamine, N-phenyl-3-aminopropyltrimethoxysilane, N- (vinylbenzyl) -2-aminoethyl-3-aminopropyl Trimethoxysilane hydrochloride, 3-ureidopropyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, bis (triethoxysilylpropyl) tetrasulfide, 3 -Isocyanate Such as pills triethoxy silane.

  The content of the silane coupling agent is not particularly limited, and an arbitrary amount can be added as necessary. The amount is preferably 10 to 10,000 parts by mass with respect to 100 parts by mass in total of the π-conjugated conductive polymer and the polyanion.

Acrylic compounds Acrylic acid, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, n-butoxyethyl methacrylate, n-butoxyethylene glycol methacrylate, methoxytriethylene glycol methacrylate, methoxypolyethylene glycol methacrylate, 2-hydroxyethyl acrylate, 2- Monofunctional (meth) acrylate compounds such as hydroxypropyl acrylate, n-butoxyethyl acrylate, n-butoxyethylene glycol acrylate, methoxytriethylene glycol acrylate, methoxypolyethylene glycol acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) Acrylate, triethylene glycol di (meth) acrylate Relate, bifunctional (meth) acrylates such as polyethylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, glycerin di (meth) acrylate, ethylene glycol diglycidyl ether, glycidyl ether, diethylene glycol diglycidyl ether, triethylene Glycidyl ethers such as glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycidyl ether, tripropylene glycidyl ether, polypropylene glycidyl ether, glycerin diglycidyl ether, 2-methacryloyloxyethyl succinic acid, glycidyl methacrylate, trimethylolpropane tri Acrylate, ethylene oxide modified trimethylolpropane triac Rate, ethylene oxide-modified pentaerythritol triacrylate, ethylene oxide modified pentaerythritol tetraacrylate and the like.

  The content of the acrylic compound is preferably 10 to 100,000 parts by mass and more preferably 50 to 10,000 parts by mass with respect to 100 parts by mass in total of the π-conjugated conductive polymer and the polyanion. . It is not preferable that the amount of the acrylic compound added is less than the lower limit because the effect of the acrylic compound addition is reduced. Moreover, when the said upper limit is exceeded, since the electroconductive fall resulting from the fall of (pi) conjugated system conductive polymer concentration will occur, it is unpreferable.

Water-soluble organic solvent Examples of the water-soluble organic solvent include N-methyl-2-pyrrolidone, N-methylacetamide, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, hexamethylene phosphortriamide, Polar solvents such as N-vinylpyrrolidone, N-vinylformamide, N-vinylacetamide, phenols such as cresol, phenol, xylenol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1,3-butylene Glycol, 1,4-butylene glycol, glycerin, diglycerin, D-glucose, D-glucitol, isoprene glycol, butanediol, 1,5-pentanediol, 1,6-hexanediol , Polyhydric aliphatic alcohols such as 1,9-nonanediol and neopentyl glycol, carbonate compounds such as ethylene carbonate and propylene carbonate, ether compounds such as dioxane and diethyl ether, dialkyl ether, propylene glycol dialkyl ether, polyethylene glycol Examples include chain ethers such as dialkyl ether and polypropylene glycol dialkyl ether, heterocyclic compounds such as 3-methyl-2-oxazolidinone, nitrile compounds such as acetonitrile, glutaronitrile, methoxyacetonitrile, propionitrile, and benzonitrile. . These solvents may be used alone or as a mixture of two or more.

[Water-soluble polymer compound]
The water-soluble polymer compound is water-soluble because the hydrophilic group is introduced 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 10 becomes higher. The terminal of polyoxyalkylene may be substituted with various substituents.
Specific examples of polyoxyalkylene include diethylene glycol, triethylene glycol, oligopolyethylene glycol, triethylene glycol monochlorohydrin, diethylene glycol monochlorohydrin, oligoethylene glycol monochlorohydrin, triethylene glycol monobromohydrin, diethylene glycol monobromhydrin, Oligoethylene glycol monobromohydrin, polyethylene glycol, glycidyl ethers, polyethylene glycol glycidyl ethers, polyethylene oxide, triethylene glycol / dimethyl ether, tetraethylene glycol / dimethyl ether, diethylene glycol / dimethyl ether, diethylene glycol / diethyl ether / diethylene glycol / Butyl ether, dipropylene glycol, tripropylene glycol, polypropylene glycol, polypropylene dioxide, polyoxyethylene alkyl ethers, polyoxyethylene glycerol fatty acid esters, polyoxyethylene fatty acid amides.

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 or a copolymer.

  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 mass average molecular weight of the water-soluble polymer compound exceeds 5,000,000, the mixing property in the conductive polymer solution is lowered, and the permeability into the pores of the dielectric layer 12 is lowered. The withstand voltage improving effect is hardly exhibited. If the mass average molecular weight is less than 100, the material tends to move in the solid electrolyte layer 13, so that the withstand voltage tends to decrease.

  Among water-soluble compounds, a water-soluble polymer compound is preferable because the withstand voltage becomes higher.

  Since the water-soluble compound described above can interact with the π-conjugated conductive polymer to improve the electrical conductivity of the π-conjugated conductive polymer, the effect of improving the conductivity of the solid electrolyte layer 13 is also achieved. Demonstrate. That is, the water-soluble compound also functions as a highly conductive agent.

[Water-dispersible compound]
A water-dispersible 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 adsorbed around a low hydrophilic compound (For example, emulsion etc.), which is dispersed without being precipitated in water.
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 12 and more preferably ½ or less of the pore diameter of the dielectric layer 12 from the viewpoint of permeability into the dielectric layer 12.

  Only one type of water-soluble compound and water-dispersible compound may be used, or two or more types may be used in combination. When two or more types of water-soluble compounds and water-dispersible compounds are used in combination, two or more types of water-soluble compounds and two or more types of water-dispersible compounds may be used. Two or more types of water-dispersible compounds may be used in combination.

  The amount of the water-soluble compound and the water-dispersible compound is preferably 1 to 10,000 parts by mass with respect to 100 parts by mass in total of the π-conjugated conductive polymer and the compound having a sulfonic acid group, More preferably, it is 5,000 parts by mass. When the content of the water-soluble compound and the water-dispersible compound is less than 1 part by mass, the withstand voltage of the capacitor 10 may not increase. When the content exceeds 10,000 parts by mass, the conductivity of the solid electrolyte layer 13 is low. Therefore, the ESR of the capacitor 10 tends to increase.

(Alkaline compound)
It is preferable that the solid electrolyte layer 13 contains an alkaline compound. When the solid electrolyte layer 13 contains an alkaline compound, it is possible to further prevent dedoping of the compound having a sulfonic acid group from the π-conjugated system conductive molecule, and to increase the conductivity.
As the alkaline compound, known inorganic alkali compounds and organic alkali compounds can be used. Examples of the inorganic alkali compound include sodium hydroxide, potassium hydroxide, calcium hydroxide, ammonia and the like.
As the organic alkali compound, a nitrogen-containing aromatic cyclic compound (aromatic amine), an aliphatic amine, a metal alkoxide, or the like can be suitably used.
Examples of the nitrogen-containing aromatic cyclic compound include those described above.
Examples of the aliphatic amine compound include ethylamine, n-octylamine, diethylamine, diisobutylamine, methylethylamine, trimethylamine, triethylamine, allylamine, 2-ethylaminoethanol, 2,2′-iminodiethanol, N-ethylethylenediamine, and the like. Can be mentioned.
Examples of the metal alkoxide include sodium alkoxide such as sodium methoxide and sodium ethoxide, potassium alkoxide, calcium alkoxide and the like.
Of the alkaline compounds, nitrogen-containing aromatic cyclic compounds are preferred. If the alkaline compound is a nitrogen-containing aromatic cyclic compound, dedoping from the π-conjugated conductive molecule of the compound having a sulfonic acid group can be particularly prevented, and the conductivity of the solid electrolyte layer 13 is particularly improved. be able to.

  The content of the alkaline compound is not particularly limited as long as the pH of the conductive polymer solution at 25 ° C. can be adjusted within a range of 3 to 13, and an arbitrary amount can be added.

<Cathode>
The cathode 14 is composed of a layer of carbon, silver, aluminum or the like, for example.
When the cathode 14 is made of carbon, silver or the like, it can be formed from a conductive paste containing a conductor such as carbon or silver. Moreover, when the cathode 14 is comprised with aluminum, it consists of aluminum foil.

  As a result of investigations by the present inventors, it was found that the capacitor 10 in which the solid electrolyte layer 13 contains a water-soluble compound or a water-dispersible compound has a low ESR and a high withstand voltage.

"Capacitor manufacturing method"
Next, a method for manufacturing the capacitor 10 will be described.
(First manufacturing method)
The first manufacturing method of the capacitor 10 is a step of attaching a conductive polymer raw material solution to the surface of the dielectric layer 12 formed by oxidizing the surface of the anode 11 made of a porous body of valve metal (hereinafter, step A). And a step of polymerizing a precursor monomer of the π-conjugated conductive polymer in the conductive polymer raw material solution adhered to the surface of the dielectric layer 12 to form the solid electrolyte layer 13 (hereinafter, step B). And a step of applying a conductive paste on the solid electrolyte layer 13 to form the cathode 14 (hereinafter referred to as step C).

[Step A]
The conductive polymer raw material solution used in step A is a water-soluble compound or water dispersibility other than a precursor monomer of a π-conjugated conductive polymer, a compound having a sulfonic acid group, and the compound having the sulfonic acid group. It contains a compound and a solvent.

  Specific examples of the precursor monomer of the π-conjugated conductive polymer include pyrrole, N-methylpyrrole, 3-methylpyrrole, 3-ethylpyrrole, 3-n-propylpyrrole, 3-butylpyrrole, and 3-octylpyrrole. 3-decylpyrrole, 3-dodecylpyrrole, 3,4-dimethylpyrrole, 3,4-dibutylpyrrole, 3-carboxylpyrrole, 3-methyl-4-carboxylpyrrole, 3-methyl-4-carboxyethylpyrrole, 3 -Methyl-4-carboxybutylpyrrole, 3-hydroxypyrrole, 3-methoxypyrrole, 3-ethoxypyrrole, 3-butoxypyrrole, 3-hexyloxypyrrole, 3-methyl-4-hexyloxypyrrole, 3-methyl-4 -Hexyloxypyrrole, thiophene, 3-methylthiophene, -Ethylthiophene, 3-propylthiophene, 3-butylthiophene, 3-hexylthiophene, 3-heptylthiophene, 3-octylthiophene, 3-decylthiophene, 3-dodecylthiophene, 3-octadecylthiophene, 3-bromothiophene, 3 -Chlorothiophene, 3-iodothiophene, 3-cyanothiophene, 3-phenylthiophene, 3,4-dimethylthiophene, 3,4-dibutylthiophene, 3-hydroxythiophene, 3-methoxythiophene, 3-ethoxythiophene, 3- Butoxythiophene, 3-hexyloxythiophene, 3-heptyloxythiophene, 3-octyloxythiophene, 3-decyloxythiophene, 3-dodecyloxythiophene, 3-octadecyloxythiophene, 3,4 -Dihydroxythiophene, 3,4-dimethoxythiophene, 3,4-diethoxythiophene, 3,4-dipropoxythiophene, 3,4-dibutoxythiophene, 3,4-dihexyloxythiophene, 3,4-diheptyloxy Thiophene, 3,4-dioctyloxythiophene, 3,4-didecyloxythiophene, 3,4-didodecyloxythiophene, 3,4-ethylenedioxythiophene, 3,4-propylenedioxythiophene, 3,4- Butenedioxythiophene, 3-methyl-4-methoxythiophene, 3-methyl-4-ethoxythiophene, 3-carboxythiophene, 3-methyl-4-carboxythiophene, 3-methyl-4-carboxyethylthiophene, 3-methyl -4-carboxybutylthiophene, aniline 2-methylaniline, 3-isobutyl aniline, 2-aniline sulfonic acid, and 3-aniline sulfonic acid.

  The compound having a sulfonic acid group, the water-soluble compound or the water-dispersible compound in the conductive polymer raw material solution is the same as that constituting the solid electrolyte layer 13.

Examples of the solvent include water and / or an organic solvent.
Examples of the organic solvent include N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, hexamethylene phosphortriamide, N-vinylpyrrolidone, N-vinylformamide, N- Polar solvents such as vinylacetamide, phenols such as cresol, phenol, xylenol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, glycerin, di Glycerin, D-glucose, D-glucitol, isoprene glycol, butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, neopentylglyco Polyhydric aliphatic alcohols such as ruthenium, ketones such as acetone and methyl ethyl ketone, hydrocarbons such as hexane, benzene and toluene, carboxylic acids such as formic acid and acetic acid, carbonate compounds such as ethylene carbonate and propylene carbonate, dioxane and diethyl Ether compounds such as ether, chain ethers such as dialkyl ether, propylene glycol dialkyl ether, polyethylene glycol dialkyl ether, polypropylene glycol dialkyl ether, heterocyclic compounds such as 3-methyl-2-oxazolidinone, acetonitrile, glutarodinitrile, methoxy Examples thereof include nitrile compounds such as acetonitrile, propionitrile, and benzonitrile. These solvents may be used alone or as a mixture of two or more.

  The content of the organic solvent is preferably 1 to 50,000 parts by mass with respect to 100 parts by mass in total of the compound having a π-conjugated conductive polymer and a sulfonic acid group, and 50 to 10,000 parts by mass. More preferably.

If necessary, an additive may be added to the conductive polymer raw material solution in order to improve the coating property and stability of the conductive polymer raw material solution, the properties of the solid electrolyte layer 13, and the like. The additive is not particularly limited as long as it can be mixed with a π-conjugated conductive polymer and a compound having a sulfonic acid group. For example, a surfactant, an antifoaming agent, a coupling agent, an antioxidant, etc. Can be used.
Surfactants include anionic surfactants such as carboxylates, sulfonates, sulfates and phosphates; cationic surfactants such as amine salts and quaternary ammonium salts; carboxybetaines and aminocarboxylic acids Examples include amphoteric surfactants such as salts and imidazolium betaines; nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene glycerin fatty acid esters, ethylene glycol fatty acid esters, and polyoxyethylene fatty acid amides.
Examples of the antifoaming agent include silicone resin, polydimethylsiloxane, and silicone resin.
Examples of the antioxidant include phenolic antioxidants, amine antioxidants, phosphorus antioxidants, sulfur antioxidants, saccharides, vitamins and the like.

The conductive polymer raw material solution preferably has a pH of 3 to 13 at 25 ° C., more preferably 5 to 11. If the pH of the conductive polymer raw material solution is 3 or more, corrosion of the dielectric layer 12 or the cathode 14 by the conductive polymer raw material solution can be prevented. However, if the pH exceeds 13, the conductivity of the π-conjugated conductive polymer tends to decrease, which is not preferable.
In order to adjust the pH of the conductive polymer raw material solution to 3 to 13, the above-described alkaline compound may be added.

  As a method for adhering the conductive polymer raw material solution in the step B to the surface of the dielectric layer 12, for example, a known method such as coating, dipping or spraying can be applied. In attaching the conductive polymer raw material solution, the pressure may be reduced, the pressure may be applied, or the solution may be centrifuged.

[Step B]
In the step B, when the precursor monomer of the π-conjugated conductive polymer is polymerized, an oxidation catalyst is usually used. Examples of the oxidation catalyst include peroxodisulfate such as ammonium peroxodisulfate (ammonium persulfate), sodium peroxodisulfate (sodium persulfate), potassium peroxodisulfate (potassium persulfate), ferric chloride, Transition metal compounds such as ferric sulfate, ferric nitrate and cupric chloride, metal halogen compounds such as boron trifluoride, metal oxides such as silver oxide and cesium oxide, peroxides such as hydrogen peroxide and ozone Products, organic peroxides such as benzoyl peroxide, oxygen and the like.
The oxidation catalyst is preferably added to the conductive polymer raw material solution in advance.

Moreover, it is preferable to heat with a heater etc. in the case of superposition | polymerization, specifically, it is preferable that heating temperature is 50-150 degreeC.
The organic solvent can be volatilized by heating. However, this heating does not necessarily remove all of the organic solvent in the conductive polymer raw material solution, and a part of the organic solvent may remain in the solid electrolyte layer 13 depending on the organic solvent.
After the polymerization, the impurities may be removed by washing with ion exchange water.

[Step C]
Examples of the conductive paste used in step C include carbon paste and silver paste.

  According to the first manufacturing method described above, the solid electrolyte layer 13 containing the π-conjugated conductive polymer, the compound having a sulfonic acid group, and a water-soluble compound or a water-dispersible compound can be formed. Therefore, the capacitor 10 having a low ESR and a high withstand voltage can be manufactured.

(Second manufacturing method)
The second manufacturing method of the capacitor 10 is a step of attaching a conductive polymer solution to the surface of the dielectric layer 12 formed by oxidizing the surface of the anode 11 made of a porous body of valve metal (hereinafter referred to as step D). And a step of drying the conductive polymer solution attached to the surface of the dielectric layer 12 to form the solid electrolyte layer 13 (hereinafter referred to as step E), and the step C described above. .

[Step D]
The conductive polymer solution used in step D includes a π-conjugated conductive polymer, a polymer having a sulfonic acid group, a water-soluble compound other than the polymer having the sulfonic acid group, or a water-dispersible compound and a solvent. It contains. As the π-conjugated conductive polymer, the polymer having a sulfonic acid group, the water-soluble compound or the water-dispersible compound, and the solvent, those described above are used. Further, the conductive polymer solution may contain the same additive as in the first production method.
As a method for preparing the conductive polymer solution, for example, first, a precursor monomer that forms a π-conjugated conductive polymer is chemically oxidatively polymerized in a solvent in the presence of a polymer having a sulfonic acid group. And a method of preparing a solution containing a complex in which a π-conjugated conductive polymer and a polymer having a sulfonic acid group are combined.

The conductive polymer solution preferably has a pH of 3 to 13 at 25 ° C, more preferably 5 to 11. If the pH of the conductive polymer solution is 3 or more, corrosion of the dielectric layer 12 by the conductive polymer solution can be prevented. However, if the pH exceeds 13, the conductivity of the π-conjugated conductive polymer tends to decrease, which is not preferable.
In order to adjust the pH of the conductive polymer solution to 3 to 13, the above-described alkaline compound may be added.

  Examples of the method for attaching the conductive polymer solution in the step D to the surface of the dielectric layer 12 include known methods such as coating, dipping, and spraying.

[Step E]
Examples of the method for drying the conductive polymer solution in Step E include known methods such as room temperature drying, hot air drying, and far-infrared drying. In this drying, not all of the organic solvent in the conductive polymer solution is necessarily removed, and a part of the organic solvent may remain in the solid electrolyte layer 13 depending on the organic solvent.

The solid electrolyte layer 13 containing a π-conjugated conductive polymer, a compound having a sulfonic acid group, and a water-soluble compound or a water-dispersible compound can also be formed by the second manufacturing method described above.
Therefore, the capacitor 10 having a low ESR and a high withstand voltage can be manufactured.

In addition, the capacitor | condenser and its manufacturing method of this invention are not limited to embodiment example mentioned above. For example, in the capacitor of the present invention, a separator can be provided between the dielectric layer and the cathode as necessary. An example of the capacitor in which a separator is provided between the dielectric layer and the cathode is a wound capacitor.
Examples of the separator include sheets (including non-woven fabric) made of polyvinyl alcohol, polyester, polyethylene, polystyrene, polypropylene, polyimide, polyamide, polyvinylidene fluoride, and non-woven fabric of glass fiber.
The density of the separator is preferably in the range of 0.1 to 1 g / cm ^3, and more preferably in the range of 0.2 to 0.8 g / cm ^3.
In the case of providing a separator, a method of forming a cathode by impregnating the separator with a carbon paste or a silver paste can also be applied.

In the capacitor of the present invention, an electrolytic solution can be used 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), tetraalkylammonium (tetramethylammonium, tetraethylammonium, tetrapropylammonium, tetrabutylammonium, Examples thereof include electrolytes containing methyltriethylammonium, dimethyldiethylammonium, etc.) as cationic components.

  In the above-described embodiment, the cathode is provided. However, when the solid electrolyte layer is used as the cathode, the cathode is not necessarily provided separately. In that case, the anode can be prevented from being damaged by the present invention, and the withstand voltage can be increased.

  Hereinafter, the present invention will be described in more detail with reference to examples. The pH in the following examples is a value measured at 25 ° C.

(Production Example 1)
(1) Preparation of conductive polymer solution 14.2 g (0.1 mol) of 3,4-ethylenedioxythiophene and 27.5 g (0.15 mol) of polystyrene sulfonic acid (2,000 ml of ion-exchanged water) (Molecular weight; about 150,000) was mixed at 20 ° C.
29.64 g (0.13 mol) of ammonium persulfate and 8.0 g (0.02 mol) of ferric sulfate dissolved in 200 ml of ion-exchanged water were kept at 20 ° C. while stirring the mixed solution thus obtained. The oxidation catalyst solution was added and stirred for 3 hours to react.
The resulting reaction solution was dialyzed to remove unreacted monomers, oxidizing agent, and oxidation catalyst, and a solution containing about 1.5% by mass of polystyrenesulfonic acid-doped poly (3,4-ethylenedioxythiophene) (hereinafter, This was referred to as a complex solution).
Then, after stirring, 0.36 g of 25 mass% ammonia water was added to 100 g of this complex solution, and then 9.0 g of polyethylene glycol 400 (number average molecular weight; 400), which is a water-soluble compound, was added. A conductive polymer solution having a pH of 8.5 was obtained.

(2) Manufacture of Capacitor The following capacitor manufacturing method is a specific example of the invention according to claim 6 of the present application.
After connecting the anode lead terminal to the etched aluminum foil (anode foil), a voltage of 100 V was applied in a 10% by weight aqueous solution of diammonium adipate to form (oxidize) the dielectric layer on the surface of the aluminum foil. This formed a capacitor intermediate.
Next, a counter aluminum cathode foil having a cathode lead terminal welded to the anode foil of the capacitor intermediate was laminated via a cellulose separator, and after winding this, the diammonium adipate in a 10% by mass aqueous solution Then, a voltage of 100 V was applied and re-formed (oxidation treatment) to obtain a capacitor element.
After immersing this capacitor element in the conductive polymer solution prepared in (1) under reduced pressure, the process of drying for 10 minutes with a 120 ° C. hot air dryer is repeated three times on the dielectric layer side surface of the capacitor intermediate. A solid electrolyte layer was formed.
Next, the capacitor element in which the solid electrolyte layer is formed is put into the electrolyte solution, impregnated under reduced pressure, and then the capacitor element is pulled up from the electrolyte solution, accommodated in an aluminum case, and sealed with a sealing rubber, A capacitor was produced. Here, the electrolyte solution used was obtained by adding 20 g of diammonium adipate to 80 g of γ-butyrolactone and heating to 120 ° C. to dissolve.
About the produced capacitor, the initial value of the electrostatic capacitance in 120 Hz and the equivalent series resistance (ESR) in 100 kHz was measured using LCZ meter 2345 (made by NF circuit design block company).
Further, the withstand voltage of the capacitor was measured as follows. Under an environment of 25 ° C., a DC voltage is applied to both electrodes, the voltage is boosted at a rate of 0.2 V / second, the voltage when the current value becomes 0.4 A is measured, and the voltage is regarded as a withstand voltage. did.
These measurement results are shown in Table 1.

(Production Examples 2 to 80)
A capacitor was produced in the same manner as in Production Example 1 except that the one shown in Tables 1 to 5 was used instead of polyethylene glycol 400, which is a water-soluble compound. And it carried out similarly to the manufacture example 1, and measured the electrostatic capacitance, the initial value of ESR, and withstand voltage. The measurement results are shown in Tables 1-5.

(Production Example 81)
A capacitor was fabricated in the same manner as in Production Example 1 except that polyethylene glycol 400 and aqueous ammonia were not added to the complex solution, and the polymer solution was used as it was as a conductive polymer solution. And it carried out similarly to the manufacture example 1, and measured the electrostatic capacitance, the initial value of ESR, and withstand voltage. Table 6 shows the measurement results.

(Production Example 82)
A capacitor was produced in the same manner as in Production Example 1 except that 0.36 g of 25% by mass ammonia water was added to 100 g of the composite solution, and polyethylene glycol 400 was not added. And it carried out similarly to the manufacture example 1, and measured the electrostatic capacitance, the initial value of ESR, and withstand voltage. Table 6 shows the measurement results.

(Production Example 83)
0.75 g of 25% by mass vinylimidazole was added to 100 g of the composite solution, and 3 g of 25% by mass polyurethane methylethylketone / isopropanol mixed solvent solution (manufactured by Arakawa Chemical Industries) was added with stirring for 3 hours. An attempt was made to prepare a conductive polymer solution by stirring. However, polyamideimide, which is neither a water-soluble polymer compound nor a water-dispersible polymer, was precipitated and a conductive polymer solution could not be obtained, so that the capacitor element could not be impregnated.

(Production Example 84)
The following capacitor manufacturing method is a specific example of the invention according to claim 4 of the present application.
In a given container, 3,4-ethylenedioxythiophene and 45 mass% p-toluenesulfonic acid iron (III) butanol solution were adjusted to a molar ratio of 2: 1, A 4-fold amount of polyethylene glycol 400 was added to oxythiophene to prepare a conductive polymer raw material solution. Next, the dielectric layer of the capacitor element was impregnated with the conductive polymer raw material solution for 60 seconds, and then this was heated in a dryer at 120 ° C. for 1 hour for chemical oxidation polymerization and drying. Next, after washing with ion-exchanged water, it was dried in a dryer at 120 ° C. to produce a solid electrolyte layer.
Next, a capacitor was produced in the same manner as in Production Example 1. And it carried out similarly to the manufacture example 1, and measured the electrostatic capacitance, the initial value of ESR, and withstand voltage. Table 7 shows the measurement results.

(Production Example 85)
A capacitor was produced in the same manner as in Production Example 84 except that thiodiethanol was added instead of polyethylene glycol 400. And it carried out similarly to the manufacture example 1, and measured the electrostatic capacitance, the initial value of ESR, and withstand voltage. Table 7 shows the measurement results.

(Production Example 86)
A capacitor was produced in the same manner as in Production Example 84 except that hydroxyethylacetamide was added in place of polyethylene glycol 400. And it carried out similarly to the manufacture example 1, and measured the electrostatic capacitance, the initial value of ESR, and withstand voltage. Table 7 shows the measurement results.

(Production Example 87)
A capacitor was produced in the same manner as in Production Example 84 except that hydroxyethyl acrylate was added instead of polyethylene glycol 400. And it carried out similarly to the manufacture example 1, and measured the electrostatic capacitance, the initial value of ESR, and withstand voltage. Table 7 shows the measurement results.

(Production Example 88)
A capacitor was produced in the same manner as in Production Example 84 except that polyethylene glycol 400 was not added. And it carried out similarly to the manufacture example 1, and measured the electrostatic capacitance, the initial value of ESR, and withstand voltage. Table 7 shows the measurement results.

The capacitors of Production Examples 1 to 80 and Production Examples 84 to 87 in which the solid electrolyte layer contains a water-soluble compound had low ESR and high withstand voltage.
The capacitors of Production Examples 81 to 82 and Production Example 88 in which the solid electrolyte layer did not contain a water-soluble compound had low withstand voltage.

10 Capacitor 11 Anode 12 Dielectric Layer 13 Solid Electrolyte Layer 14 Cathode

Claims (6)

In a capacitor comprising an anode made of a porous body of valve metal, a dielectric layer formed by oxidizing the anode surface, and a solid electrolyte layer formed on the surface side of the dielectric layer,
A capacitor, wherein the solid electrolyte layer contains a π-conjugated conductive polymer, a compound having a sulfonic acid group, and a water-soluble compound or a water-dispersible compound other than the compound having the sulfonic acid group.   The capacitor according to claim 1, wherein the water-soluble compound is a water-soluble polymer compound.   The capacitor according to claim 1, wherein the solid electrolyte layer further contains an alkaline compound. Other than a compound having a π-conjugated conductive polymer precursor monomer, a sulfonic acid group compound, and a compound having a sulfonic acid group on the surface of a dielectric layer formed by oxidizing the surface of an anode made of a porous body of a valve metal Attaching a conductive polymer raw material solution containing a water-soluble compound or a water-dispersible compound and a solvent;
And a step of polymerizing a precursor monomer of a π-conjugated conductive polymer in a conductive polymer raw material solution adhered to the surface of the dielectric layer. On the surface of the dielectric layer formed by oxidizing the surface of the anode made of a porous body of the valve metal, a water solution other than the π-conjugated conductive polymer, the polymer having a sulfonic acid group, and the polymer having the sulfonic acid group Attaching a conductive polymer solution containing a conductive compound or a water-dispersible compound and a solvent;
And a step of drying the conductive polymer solution adhered to the surface of the dielectric layer.   The method for producing a capacitor according to claim 5, wherein the pH of the conductive polymer solution at 25 ° C is 3 to 13.

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