JP2020100743A - Capacitor, production method thereof, and conductive polymer dispersion - Google Patents

Abstract

To provide a capacitor which has a smaller equivalent series resistance than the prior art and is excellent in heat resistance, a production method thereof, and a conductive polymer dispersion suitable for the production of the capacitor.SOLUTION: A capacitor 10 comprises: a positive electrode 11 comprising a porous body of a valve metal; a dielectric layer 12 comprising oxide of the valve metal; a negative electrode 13 made of a conductive substance disposed on a side of the dielectric layer opposite to the positive electrode; and a solid electrolyte layer 14 formed between the dielectric layer and the negative electrode. The solid electrolyte layer comprises: a conductive composite comprising a π-conjugated conductive polymer and a polyanion; and a compound represented by a specific chemical formula having a basic skeleton of a hexose.SELECTED DRAWING: Figure 1

Description

The present invention relates to a capacitor provided with a solid electrolyte layer containing a π-conjugated conductive polymer, a method for manufacturing the same, and a conductive polymer dispersion liquid.

In order to reduce the equivalent series resistance of the capacitor, a solid electrolyte layer formed of a conductive polymer dispersion liquid containing poly(3,4-ethylenedioxythiophene) and polystyrene sulfonic acid is used as a dielectric layer and a cathode. A capacitor arranged in between is known (for example, Patent Document 1).

JP, 2014-67949, A

A conventional capacitor manufactured using a conductive polymer dispersion liquid is required to further reduce its equivalent series resistance. Further, improvement in heat resistance of capacitors is also desired.
The present invention provides a capacitor having an equivalent series resistance smaller than that of a conventional one and excellent heat resistance, a method for manufacturing the capacitor, and a conductive polymer dispersion liquid suitable for manufacturing the capacitor.

[1] A conductive polymer dispersion liquid containing a conductive complex containing a π-conjugated conductive polymer and a polyanion, at least one compound represented by the following formula (1), and a dispersion medium.
[2] In the compound represented by the formula (1), R _{1 to} R ₄ are hydrogen atoms, and at least one of R ₅ is a hydroxy group or the following formula (2A) or formula (2B). Alternatively, the conductive polymer dispersion liquid according to [1], containing a compound which is a substituent represented by the formula (2C).
_{- (CH 2) n1 -OH ···} (2A)
_{- (CH 2) n2 -H ···} (2B)
_{-O- (CH 2) n3 -H ···} (2C)
[In Formula (2A), Formula (2B), and Formula (2C), n1, n2, and n3 represent the integer of 1-3 each independently. ]
[3] The conductive polymer dispersion liquid according to [1], wherein the compound represented by the formula (1) contains at least one of arbutin and salicin.
[4] The conductive polymer dispersion liquid according to any one of [1] to [3], further containing at least one of a nitrogen-containing aromatic cyclic compound and a tertiary amine.
[5] The conductive polymer dispersion liquid according to [4], which contains the nitrogen-containing aromatic cyclic compound, and the nitrogen-containing aromatic cyclic compound contains imidazole.
[6] The conductive polymer dispersion liquid according to [4], which contains the tertiary amine, and the tertiary amine contains triethylamine.
[7] The conductivity according to any one of [1] to [6], further containing at least one kind of compound having two or more hydroxy groups, which is different from the compound represented by the formula (1). Polymer dispersion.
[8] The conductive polymer dispersion liquid according to any one of [1] to [7], wherein the π-conjugated conductive polymer is poly(3,4-ethylenedioxythiophene).
[9] The conductive polymer dispersion liquid according to any one of [1] to [8], wherein the polyanion is polystyrene sulfonic acid.
[10] An anode made of a porous body of a valve metal, a dielectric layer made of an oxide of the valve metal, a cathode made of a conductive material, which is provided on a side of the dielectric layer opposite to the anode, A solid electrolyte layer formed between the dielectric layer and the cathode, wherein the solid electrolyte layer is a conductive composite containing a π-conjugated conductive polymer and a polyanion, and is represented by the following formula (1): A capacitor having at least one of the compounds described above.
[11] In the compound represented by the formula (1), R _{1 to} R ₄ are hydrogen atoms, and at least one of R ₅ is a hydroxy group or the following formula (2A) or formula (2B). Alternatively, the capacitor according to [10], which contains a compound that is a substituent represented by formula (2C).
_{- (CH 2) n1 -OH ···} (2A)
_{- (CH 2) n2 -H ···} (2B)
_{-O- (CH 2) n3 -H ···} (2C)
[In Formula (2A), Formula (2B), and Formula (2C), n1, n2, and n3 represent the integer of 1-3 each independently. ]
[12] The capacitor according to [10], wherein the compound represented by the formula (1) contains at least one of arbutin and salicin.
[13] The capacitor according to [10] or [11], wherein the solid electrolyte layer further contains at least one of a nitrogen-containing aromatic cyclic compound and a tertiary amine.
[14] The capacitor according to [13], which contains the nitrogen-containing aromatic cyclic compound, and the nitrogen-containing aromatic cyclic compound contains imidazole.
[15] The capacitor according to [13], which contains the tertiary amine, and the tertiary amine contains triethylamine.
[16] Any one of [10] to [15], wherein the solid electrolyte layer further contains at least one kind of compound having two or more hydroxy groups different from the compound represented by the formula (1). The capacitor described in.
[17] The capacitor according to any one of [10] to [16], wherein the π-conjugated conductive polymer is poly(3,4-ethylenedioxythiophene).
[18] The capacitor according to any one of [10] to [17], wherein the polyanion is polystyrene sulfonic acid.
[19] A step of oxidizing a surface of an anode made of a valve metal porous body to form a dielectric layer, a step of disposing a cathode at a position facing the dielectric layer, and a step of forming a dielectric layer on the surface of the dielectric layer. A method of manufacturing a capacitor, comprising the steps of applying the conductive polymer dispersion liquid according to any one of [1] to [9] and drying the liquid to form a solid electrolyte layer.

［式（１）中、Ｒ_１〜Ｒ_５はそれぞれ独立に、水素原子または任意の置換基を表し、ｍは１〜５の整数を表す。］

[In the formula (1), R _{1 to} R ₅ each independently represent a hydrogen atom or any substituent, and m represents an integer of 1 to 5. ]

Since the capacitor of the present invention is excellent in heat resistance and has an equivalent series resistance smaller than that of the conventional one, it contributes to high performance of electronic devices.
According to the method of manufacturing a capacitor of the present invention, it is possible to easily manufacture a capacitor having excellent heat resistance and a small equivalent series resistance.
The conductive polymer dispersion of the present invention has excellent heat resistance and is suitable for forming a solid electrolyte layer of a capacitor having a low equivalent series resistance.

It is sectional drawing which shows one Embodiment of the capacitor of this invention.

《Capacitor》
An embodiment of the capacitor of the present invention will be described. As shown in FIG. 1, a capacitor 10 according to the present embodiment is formed on the surface of an anode 11 made of a valve metal porous body, a dielectric layer 12 made of a valve metal oxide, and a dielectric layer 12. The solid electrolyte layer 14 and the cathode 13 provided on the most front side are provided. The cathode 13 is provided on the opposite side of the anode 11 with the dielectric layer 12 and the solid electrolyte layer 14 interposed therebetween.

Examples of the valve metal forming the anode 11 include aluminum, tantalum, niobium, titanium, hafnium, zirconium, zinc, tungsten, bismuth, antimony and the like. 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 thereof, and those obtained by oxidizing the surface of a sintered body of tantalum particles or niobium particles into pellets. Can be mentioned. The material thus treated becomes a porous body having irregularities formed on the surface.

The dielectric layer 12 in the present embodiment is a layer formed by oxidizing the surface of the anode 11. For example, the surface of the metal anode 11 is anodized in an electrolytic solution such as an aqueous solution of ammonium adipate. It is formed by that. Therefore, as shown in FIG. 1, unevenness is formed on the dielectric layer 12 as well as the anode 11.

As the cathode 13 in the present embodiment, a metal layer made of a conductive material such as a conductive layer formed of a conductive paste or an aluminum foil can be used.

The solid electrolyte layer 14 in the present embodiment is formed on the surface of the dielectric layer 12. The solid electrolyte layer 14 covers at least a part of the surface of the dielectric layer 12, and may cover the entire surface of the dielectric layer 12.
The thickness of the solid electrolyte layer 14 may or may not be constant, and examples thereof include a thickness of 1 μm or more and 100 μm or less.

The solid electrolyte layer 14 contains one or more kinds of compounds represented by the following formula (1) (hereinafter sometimes referred to as compound 1), and a π-conjugated conductive polymer and a polyanion described in detail later. And a conductive composite.

［式（１）中、Ｒ_１〜Ｒ_５はそれぞれ独立に、水素原子または任意の置換基を表し、ｍは１〜５の整数を表す。］

[In the formula (1), R _{1 to} R ₅ each independently represent a hydrogen atom or any substituent, and m represents an integer of 1 to 5. ]

In the formula (1), R _{1 to} R ₅ are each independently a hydrogen atom or an arbitrary substituent. When m is an integer of 2 or more, each R ₅ is independently a hydrogen atom or an optional substituent.
The optional substituent is not particularly limited, and is a monovalent group such as an alkyl group, an aryl group, an aralkyl group, an acetyl group, a hydroxy group, a methylol group, an alkoxy group, an acetoxy group, a formyl group, an amino group or a nitro group. Groups. Moreover, the number of the substituents of R ₅ may be one or more, and the plurality of R ₅ may be the same or different substituents.

Examples of the compound represented by the formula (1) include phenyl β-D-glucopyranoside, phenyl β-D-galactopyranoside, phenyl α-D-galactopyranoside, and 4-methoxyphenyl β-D-. Galactopyranoside, 4-methoxyphenyl β-D-glucopyranoside, 4-methoxyphenyl α-D-mannopyranoside, arbutin (also known as 4-hydroxyphenyl β-D-glucopyranoside), 4-aminophenyl β-D-galactopyranoside Noside, 4-methoxyphenyl 3-O-allyl-β-D-galactopyranoside, heliside (also known as 4-formylphenyl β-D-allopyranoside), gastrodin (also known as 4-(hydroxymethyl)phenyl β- D-glucopyranoside), helicin (alias: 2-formylphenyl β-D-glucopyranoside), sakaquin (alias: 3-hydroxy-5-methylphenyl β-D-glucopyranoside), 4-methoxyphenyl 2,6-di-O. -Benzyl-β-D-galactopyranoside, 4-methoxyphenyl 3-O-benzyl-β-D-glucopyranoside, 4-methoxyphenyl 3-O-benzyl-β-D-galactopyranoside, salicin (alias) : 2-(hydroxymethyl)phenyl β-D-glucopyranoside), 4-methoxyphenyl 2,4,6-tri-O-benzyl-β-D-galactopyranoside, 4-methoxyphenyl 2,3,6- Tri-O-benzyl-β-D-galactopyranoside, 4-methoxyphenyl 2,3,4,6-tetra-O-acetyl-β-D-galactopyranoside, 4-methoxyphenyl 2,3. 4,6-Tetra-O-acetyl-β-D-glucopyranoside, 4-methoxyphenyl 2,3,4,6-tetra-O-acetyl-α-D-mannopyranoside, 2-acetyl-5-methoxyphenyl β- D-glucopyranoside, 4-methoxyphenol 2-O-benzoyl-3,6-di-O-benzyl-β-D-glucopyranoside, piceide (also known as 4′,5-dihydroxystilben-3-yl β-D-glucopyranoside) ), 4-nitrophenyl α-D-glucoronide, 4-methoxyphenyl 2,3,4,6-tetra O-benzyl-β-D-galactopyranoside, 4-methoxyphenyl 2,4,6-tri-. O-acetyl-3-O-benzyl-β-D-glucopyranoside, phlorizin, curculigoside A (alias: 2-[[(2,6-dimethoxybenzoyl)oxy]methyl] -4-hydroxyphenyl β-D-glucopyranoside) and the like.

From the viewpoint of further exerting the effect of the present invention, in the compound represented by the formula (1), R _{1 to} R ₄ are hydrogen atoms, and at least one of R ₅ is a hydroxy group or the following. It is preferably a substituent represented by formula (2A), formula (2B) or formula (2C).
_{- (CH 2) n1 -OH ···} (2A)
_{- (CH 2) n2 -H ···} (2B)
_{-O- (CH 2) n3 -H ···} (2C)
[In Formula (2A), Formula (2B), and Formula (2C), n1, n2, and n3 represent the integer of 1-3 each independently. ]

In the formula (2A), n1 is preferably 1 or 2, and more preferably 1.
In the formula (2B), n2 is preferably 1 or 2, and more preferably 1.
In the formula (2C), n3 is preferably 1 or 2, and more preferably 1.

In the above formula (1), the bonding position of the substituent R ₅ is preferably the ortho position or the para position.
In the compound represented by the formula (1), the substituents R _{1 to} R ₄ are hydrogen atoms, and R ₅ is arbutin having a hydroxy group bonded to the para position (also known as 4-hydroxyphenyl β-D-glucopyranoside). Or, the substituents R _{1 to} R ₄ are hydrogen atoms, and preferably salicin in which one methylol group is bonded to the ortho position (alias: 2-(hydroxymethyl)phenyl β-D-glucopyranoside).

The total content of the compounds 1 contained in the solid electrolyte layer 14 is preferably 1 part by mass or more and 1000 parts by mass or less, and 10 parts by mass with respect to 100 parts by mass of a conductive composite described later contained in the solid electrolyte layer 14. It is more preferably 500 parts by mass or more and 100 parts by mass or more and 400 parts by mass or less, and particularly preferably 150 parts by mass or more and 300 parts by mass or less.
The above range is preferable because the equivalent series resistance of the capacitor is more likely to be lowered and the heat resistance is more likely to be further improved.
The type of the compound 1 contained in the solid electrolyte layer 14 may be one type or two or more types.

Next, the conductive complex containing the π-conjugated conductive polymer and the polyanion contained in the solid electrolyte layer 14 will be described.
The π-conjugated conductive polymer is not particularly limited as long as it is an organic polymer whose main chain is composed of a π-conjugated system. For example, polypyrrole-based conductive polymer, polythiophene-based conductive polymer, polyacetylene-based polymer Conductive polymer, polyphenylene-based conductive polymer, polyphenylene vinylene-based conductive polymer, polyaniline-based conductive polymer, polyacene-based conductive polymer, polythiophene vinylene-based conductive polymer, and copolymers thereof, etc. Can be mentioned. From the viewpoint of stability in air, polypyrrole-based conductive polymers, polythiophene-based conductive polymers and polyaniline-based conductive polymers are preferable, and polythiophene-based conductive polymers are more preferable.

Examples of the polythiophene-based conductive polymer include polythiophene, poly(3-methylthiophene), poly(3-ethylthiophene), poly(3-propylthiophene), poly(3-butylthiophene), poly(3-hexyl). Thiophene), 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-dibutyl) Thiophene), poly(3-hydroxythiophene), poly(3-methoxythiophene), poly(3-ethoxythiophene), poly(3-butoxythiophene), poly(3-hexyloxythiophene), poly(3-heptyloxy) Thiophene), 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-dihexyloxy) Thiophene), poly(3,4-diheptyloxythiophene), poly(3,4-dioctyloxythiophene), poly(3,4-didecyloxythiophene), poly(3,4-didodecyloxythiophene), Poly(3,4-ethylenedioxythiophene), poly(3,4-propylenedioxythiophene), poly(3,4-butylenedioxythiophene), 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).

Examples of the polypyrrole-based conductive polymer include polypyrrole, poly(N-methylpyrrole), poly(3-methylpyrrole), poly(3-ethylpyrrole), 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-hydroxy) Pyrrole), poly(3-methoxypyrrole), poly(3-ethoxypyrrole), poly(3-butoxypyrrole), poly(3-hexyloxypyrrole), poly(3-methyl-4-hexyloxypyrrole). To be

Examples of the polyaniline-based conductive polymer include polyaniline, poly(2-methylaniline), poly(3-isobutylaniline), poly(2-anilinesulfonic acid), and poly(3-anilinesulfonic acid).
Among the π-conjugated conductive polymers exemplified above, poly(3,4-ethylenedioxythiophene) is particularly preferable in terms of conductivity and heat resistance.
The π-conjugated conductive polymer may be used alone or in combination of two or more.

The polyanion is a polymer having two or more monomer units having an anion group in the molecule. The anion group of this polyanion functions as a dopant for the π-conjugated conductive polymer, and can improve the conductivity of the π-conjugated conductive polymer.
The anion group of the polyanion is preferably a sulfo group or a carboxy group.
Specific examples of the polyanion include polystyrenesulfonic acid, polyvinylsulfonic acid, polyallylsulfonic acid, polyacrylic acid ester having a sulfo group, and polymethacrylic acid ester having a sulfo group (for example, poly(4-sulfobutylmethacrylate, polysulfone). Polymers having sulfo groups such as ethyl methacrylate, polymethacryloyloxybenzene sulfonic acid), poly(2-acrylamido-2-methylpropane sulfonic acid), polyisoprene sulfonic acid, polyvinyl carboxylic acid, polystyrene carboxylic acid, polyallyl carboxylic acid Examples thereof include polymers having a carboxy group such as acid, polyacrylic acid, polymethacrylic acid, poly(2-acrylamido-2-methylpropanecarboxylic acid), and polyisoprenecarboxylic acid, which may be homopolymers thereof. However, it may be a copolymer of two or more kinds.
Among these polyanions, a polymer having a sulfo group is preferable, and polystyrene sulfonic acid is more preferable, because the polymer can have higher conductivity.
The polyanions may be used alone or in combination of two or more.
The mass average molecular weight of the polyanion is preferably 20,000 or more and 1,000,000 or less, and more preferably 100,000 or more and 500,000 or less.
The mass average molecular weight of the polyanion is a value obtained by measuring with gel permeation chromatography and using polystyrene as the standard substance.

The content ratio of the polyanion in the conductive composite is preferably in the range of 1 part by mass or more and 1000 parts by mass or less, and 10 parts by mass or more and 700 parts by mass with respect to 100 parts by mass of the π-conjugated conductive polymer. The following range is more preferable, and a range of 100 parts by mass or more and 500 parts by mass or less is even more preferable. When the content ratio of the polyanion is not less than the lower limit value, the doping effect on the π-conjugated conductive polymer tends to be strong, sufficient conductivity is easily obtained, and the conductivity in the conductive polymer dispersion liquid is further increased. The dispersibility of the composite is high. Moreover, when the content of the polyanion is not more than the upper limit value, the relative content of the π-conjugated conductive polymer increases, and sufficient conductivity is easily obtained.

A polyanion is coordinated with and doped in the π-conjugated conductive polymer to form a conductive composite. From the viewpoint of improving the conductivity and dispersibility of the conductive composite, it is preferable that all the anion groups have an excess of anion groups that do not contribute to the doping, rather than dope the π-conjugated conductive polymer.

The content of the conductive composite with respect to the total mass of the solid electrolyte layer 14 is preferably 1% by mass or more and 90% by mass or less, more preferably 10% by mass or more and 70% by mass or less, and further 20% by mass or more and 60% by mass or less. preferable. The above range is preferable because the equivalent series resistance of the capacitor is more likely to decrease.

The solid electrolyte layer 14 may contain one or more nitrogen-containing compounds. By including the nitrogen-containing compound in the solid electrolyte layer 14, the equivalent series resistance of the capacitor can be further reduced.

Examples of the nitrogen-containing compound include the following amine compounds and nitrogen-containing aromatic cyclic compounds. If at least one of the amine compound and the nitrogen-containing aromatic cyclic compound is contained in the solid electrolyte layer 14, the equivalent series resistance of the capacitor can be further reduced.
The amine compound is a compound having an amino group, and the amino group reacts with the anion group of the polyanion.
The amine compound may be any of primary amine, secondary amine, tertiary amine, and quaternary ammonium salt. The amine compounds may be used alone or in combination of two or more.
The amine compound is a linear or branched alkyl group having 2 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, and an alkylene group having 2 to 12 carbon atoms. It may have a substituent selected from an arylene group having 6 to 12 carbon atoms, an aralkylene group having 7 to 12 carbon atoms, and an oxyalkylene group having 2 to 12 carbon atoms.
Specific examples of primary amines include aniline, toluidine, benzylamine, ethanolamine and the like.
Specific examples of secondary amines include diethanolamine, dimethylamine, diethylamine, dipropylamine, diphenylamine, dibenzylamine, dinaphthylamine and the like.
Specific examples of the tertiary amine include triethanolamine, trimethylamine, triethylamine, tripropylamine, tributylamine, trioctylamine, triphenylamine, tribenzylamine, trinaphthylamine and the like.
Specific examples of the quaternary ammonium salt include tetramethyl ammonium salt, tetraethyl ammonium salt, tetrapropyl ammonium salt, tetraphenyl ammonium salt, tetrabenzyl ammonium salt, tetranaphthyl ammonium salt and the like. Examples of the anion paired with ammonium include hydroxide ion.
Of these amine compounds, tertiary amines are preferable, and triethylamine and tripropylamine are more preferable.
Examples of the nitrogen-containing aromatic cyclic compound (aromatic compound in which at least one nitrogen atom forms a ring structure) include, for example, pyrrole, imidazole, 2-methylimidazole, 2-propylimidazole, N-methylimidazole, N -Propylimidazole, N-butylimidazole, 1-(2-hydroxyethyl)imidazole, 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2- Methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 1-acetylimidazole, 2-aminobenzimidazole, 2-amino-1-methylbenzimidazole, 2 -Hydroxybenzimidazole, 2-(2-pyridyl)benzimidazole, pyridine and the like can be mentioned.
Among these nitrogen-containing aromatic cyclic compounds, imidazole is more preferable.

The total content of the nitrogen-containing compounds contained in the solid electrolyte layer 14 is preferably 1 part by mass or more and 100 parts by mass or less, and 5 parts by mass with respect to 100 parts by mass of the conductive complex contained in the solid electrolyte layer 14. It is more preferably 30 parts by mass or more and 10 parts by mass or more and 25 parts by mass or less.
The above range is preferable because the equivalent series resistance of the capacitor is more likely to be lowered and the heat resistance is more likely to be further improved.
The type of the nitrogen-containing compound contained in the solid electrolyte layer 14 may be one type or two or more types.

In the solid electrolyte layer 14, at least one compound different from the compound 1, the conductive complex, and the nitrogen-containing compound and having two or more hydroxy groups (hereinafter, may be referred to as a polyol compound). Further, it is preferable that it is contained. By containing the polyol compound, the ESR of the capacitor can be further reduced.
Examples of the polyol compound include one or more selected from ethylene glycol, diethylene glycol, propylene glycol, 1,4-butanediol, glycerin, pentaerythritol, trimethylolpropane and trimethylolethane.
The polyol compound may be contained as a solvent for the electrolyte described later or as a dispersion medium for the conductive composite.

The total content of the polyol compounds contained in the solid electrolyte layer 14 is preferably 100 parts by mass or more and 10000 parts by mass or less, and 200 parts by mass or more with respect to 100 parts by mass of the conductive composite contained in the solid electrolyte layer 14. The amount is preferably 2000 parts by mass or less, more preferably 300 parts by mass or more and 1000 parts by mass or less.
The above range is preferable because the equivalent series resistance of the capacitor is more likely to be lowered and the heat resistance is more likely to be further improved.
The type of the polyol compound contained in the solid electrolyte layer 14 may be one type or two or more types.

The solid electrolyte layer 14 may include an electrolytic solution in which an electrolyte is dissolved in an electrolytic solution solvent. The higher the electric conductivity of the electrolytic solution, the more preferable.
Examples of the solvent for the electrolytic solution include ethylene glycol, diethylene glycol, propylene glycol, 1,4-butanediol, alcohol solvents such as glycerin, γ-butyrolactone, γ-valerolactone, and lactone solvents such as 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, and water.
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-decanedicarboxylic acid and other decanedicarboxylic acids, 1,7-octanedicarboxylic acid and other octanedicarboxylic acids, azelaic acid, sebacic acid and other organic acids; or boric acid, and boric acid obtained from boric acid and polyhydric alcohols. Polyhydric alcohol complex compound: Anionic component is an inorganic acid such as phosphoric acid, carbonic acid, silicic acid and the like, primary amines (methylamine, ethylamine, propylamine, butylamine, ethylenediamine, etc.), secondary amines (dimethylamine, diethylamine, diamine) Propylamine, methylethylamine, diphenylamine, etc., tertiary amines (trimethylamine, triethylamine, tripropylamine, triphenylamine, 1,8-diazabicyclo(5,4,0)-undecene-7 etc.), tetraalkylammonium (tetra Electrolytes containing cation components such as methylammonium, tetraethylammonium, tetrapropylammonium, tetrabutylammonium, methyltriethylammonium, and dimethyldiethylammonium; and the like.

<Effect>
By containing the compound represented by the above formula (1) in the solid electrolyte layer of the capacitor of the present invention, the equivalent series resistance of the capacitor can be remarkably reduced as compared with the conventional case, with almost no reduction in capacitance. it can. Although the mechanism has not been clarified, it is presumed that the equivalent series resistance of the compound is reduced by improving the conductivity of the solid electrolyte layer.
Further, the solid electrolyte layer of the capacitor of the present invention contains the compound represented by the above formula (1), so that the heat resistance of the capacitor can be improved. Although this mechanism has not been clarified, it is presumed that the heat resistance is improved by improving the stability of the conductive complex contained in the solid electrolyte layer by the compound.

<<Capacitor manufacturing method, conductive polymer dispersion liquid>>
In the capacitor according to the present invention, a step of oxidizing a surface of an anode made of a porous body of a valve metal to form a dielectric layer (dielectric forming step), and disposing a cathode at a position facing the dielectric layer. It can be manufactured by a step (cathode forming step) and a step of applying a conductive polymer dispersion liquid on at least a part of the surface of the dielectric layer and drying it to form a solid electrolyte layer.

The conductive polymer dispersion liquid is a dispersion liquid in which one or more compounds represented by the formula (1) are contained and a conductive complex containing a π-conjugated conductive polymer and a polyanion is further dispersed. is there.
The conductive polymer dispersion liquid may contain the nitrogen-containing compound, the polyol compound, the additives described below, and the like.

The dielectric layer forming step is a step of forming the dielectric layer 12 by oxidizing the surface of the anode 11 made of a valve metal porous body.
Examples of the method of forming the dielectric layer 12 include a method of anodizing the surface of the anode 11 in an electrolytic solution for chemical conversion treatment such as an aqueous solution of ammonium adipate, an aqueous solution of ammonium borate, an aqueous solution of ammonium phosphate. ..

The cathode forming step is a step of disposing the cathode 13 at a position facing the dielectric layer 12.
Examples of the method of disposing the cathode 13 include a method of forming the cathode 13 using a conductive paste such as a carbon paste or a silver paste, and a method of disposing a metal foil such as an aluminum foil so as to face the dielectric layer 12. To be

The solid electrolyte layer forming step is a step of forming the solid electrolyte layer 14 by applying the conductive polymer dispersion liquid on at least a part of the surface of the dielectric layer 12 and drying it.

The dispersion medium that constitutes the conductive polymer dispersion is not particularly limited as long as it is a liquid that can disperse the conductive composite, and examples thereof include water, an organic solvent, or a mixed liquid of water and an organic solvent. To be
Examples of the organic solvent include alcohol solvents, ether solvents, ketone solvents, ester solvents, aromatic hydrocarbon solvents and the like. These organic solvents may be used alone or in combination of two or more.
Examples of the alcohol-based solvent include methanol, ethanol, isopropanol, n-butanol, t-butanol, allyl alcohol and the like.
Examples of ether solvents include propylene glycol monoalkyl ethers such as diethyl ether, dimethyl ether, ethylene glycol, propylene glycol and propylene glycol monomethyl ether, and propylene glycol dialkyl ether.
Examples of the ketone solvent include diethyl ketone, methyl propyl ketone, methyl butyl ketone, methyl isopropyl ketone, methyl isobutyl ketone, methyl amyl ketone, diisopropyl ketone, methyl ethyl ketone, acetone and diacetone alcohol.
Examples of the ester solvent include ethyl acetate, propyl acetate, butyl acetate and the like.
Examples of aromatic hydrocarbon solvents include benzene, toluene, xylene, ethylbenzene, propylbenzene, isopropylbenzene and the like.

Examples of the additive include a surfactant, an inorganic conductive agent, a defoaming agent, a coupling agent, an antioxidant, an ultraviolet absorber and the like. However, the additive is a compound other than the compound represented by the formula (1), the conductive complex, the nitrogen-containing compound, the polyol compound, and the solvent (dispersion medium).
Examples of the surfactant include nonionic, anionic and cationic surfactants, and the nonionic surfactant is preferable from the viewpoint of storage stability. Moreover, you may add polymeric surfactants, such as polyvinyl alcohol and polyvinyl pyrrolidone.
Examples of the inorganic conductive agent include metal ions and conductive carbon. The metal ion can be generated by dissolving a metal salt in water.
Examples of the defoaming agent include silicone resin, polydimethylsiloxane, silicone oil and the like.
Examples of the coupling agent include silane coupling agents having a vinyl group, an amino group, an epoxy group and the like.
Examples of antioxidants include phenolic antioxidants, amine antioxidants, phosphorus antioxidants, sulfur antioxidants, and sugars.
As the ultraviolet absorber, benzotriazole ultraviolet absorber, benzophenone ultraviolet absorber, salicylate ultraviolet absorber, cyanoacrylate ultraviolet absorber, oxanilide ultraviolet absorber, hindered amine ultraviolet absorber, benzoate ultraviolet absorber, etc. Are listed.

The content of the conductive composite with respect to the total mass of the conductive polymer dispersion is not particularly limited, and a content that provides a viscosity that is easy to apply is preferable. Specifically, for example, 0.1% by mass or more and 10% by mass or less is preferable, 0.5% by mass or more and 5% by mass or less is more preferable, and 1% by mass or more and 2% by mass or less is further preferable.

The total content of the compounds represented by the formula (1) with respect to the total mass of the conductive polymer dispersion is not particularly limited, and a content that provides a viscosity that is easy to apply is preferable. Specifically, for example, 0.1 mass% or more and 20 mass% or less is preferable, 0.5 mass% or more and 10 mass% or less is more preferable, and 1 mass% or more and 5 mass% or less is further preferable.

The total content of the compounds 1 contained in the conductive polymer dispersion is preferably 1 part by mass or more and 1000 parts by mass or less with respect to 100 parts by mass of the conductive complex contained in the conductive polymer dispersion. The content is more preferably not less than 500 parts by mass, more preferably not less than 100 parts by mass and not more than 400 parts by mass, particularly preferably not less than 150 parts by mass and not more than 300 parts by mass.
The above range is preferable because, when a capacitor is manufactured using the conductive polymer dispersion liquid according to the present invention, the equivalent series resistance of the capacitor is more likely to be lowered and the heat resistance is more likely to be further improved.

When the conductive polymer dispersion contains the nitrogen-containing compound, the content ratio is appropriately determined according to the type of the nitrogen-containing compound, for example, with respect to 100 parts by mass of the solid content of the conductive composite, For example, 1 part by mass or more and 100 parts by mass or less is preferable, 5 parts by mass or more and 50 parts by mass or less is more preferable, and 10 parts by mass or more and 20 parts by mass or less is further preferable.
The above range is preferable because, when a capacitor is manufactured using the conductive polymer dispersion liquid according to the present invention, the equivalent series resistance of the capacitor is more likely to be lowered and the heat resistance is more likely to be further improved.

When the conductive polymer dispersion contains the polyol compound, the content ratio is appropriately determined according to the type of the polyol compound, for example, with respect to 100 parts by mass of the solid content of the conductive composite, for example, The amount is preferably 100 parts by mass or more and 10000 parts by mass or less, more preferably 200 parts by mass or more and 2000 parts by mass or less, and further preferably 300 parts by mass or more and 1000 parts by mass or less.

When the conductive polymer dispersion contains the additive, the content ratio is appropriately determined according to the type of the additive, for example, with respect to 100 parts by mass of the solid content of the conductive composite, for example, It can be in the range of 1 part by mass or more and 1000 parts by mass or less.

Examples of the method for preparing the conductive polymer dispersion liquid include a method in which a precursor monomer forming a π-conjugated conductive polymer is oxidatively polymerized in the presence of a polyanion and a dispersion medium.
The compound represented by the formula (1) is added to the obtained conductive polymer dispersion, and if necessary, the nitrogen-containing compound, the compound having two or more hydroxy groups, and additives. Can be added.
For the purpose of improving the dispersibility of each material contained in the conductive polymer dispersion, it is preferable to perform a known high dispersion treatment in which the conductive polymer dispersion is dispersed while applying a shearing force before coating.

As the method for applying the conductive polymer dispersion liquid, for example, dipping (dip coating), comma coating, reverse coating, lip coating, microgravure coating, or the like can be applied. Of these, immersion is preferable from the viewpoint that the solid electrolyte layer 14 can be easily formed between the dielectric layer 12 and the cathode 13.
Examples of the drying method include room temperature drying, hot air drying, far infrared ray drying and the like.

The capacitor of the present invention and the method for manufacturing the same are not limited to the examples of the above embodiments.
In the capacitor of the present invention, a separator may be provided between the dielectric layer and the cathode.
A wound type capacitor may be used as the capacitor provided with the separator between the dielectric layer and the cathode.
Examples of the separator include a sheet (including a non-woven fabric) made of cellulose, polyvinyl alcohol, polyester, polyethylene, polystyrene, polypropylene, polyimide, polyamide, polyvinylidene fluoride, or the like, a non-woven fabric of glass fiber, or the like.
The density of the separator is preferably 0.1 g/cm ³ or more and 1.0 g/cm ³ or less, and more preferably 0.2 g/cm ³ or more and 0.8 g/cm ³ or less.
When a separator is provided, a method of impregnating the separator with a carbon paste or a silver paste to form a cathode can also be applied.

(Production Example 1)
Dissolve 206 g of sodium styrenesulfonate in 1000 ml of ion-exchanged water, add 1.14 g of ammonium persulfate oxidizer solution previously dissolved in 10 ml of water for 20 minutes while stirring at 80° C., and stir this solution for 12 hours. It was stirred.
1000 ml of sulfuric acid diluted to 10% by mass was added to the obtained sodium styrenesulfonate-containing solution, and about 1000 ml of the solvent of the polystyrenesulfonic acid-containing solution was removed by an ultrafiltration method. 2000 ml of ion-exchanged water was added to the residual liquid, about 2000 ml of the solvent was removed by an ultrafiltration method, and polystyrene sulfonic acid was washed with water. This ultrafiltration operation was repeated 3 times.
Water in the obtained solution was removed under reduced pressure to obtain colorless solid polystyrenesulfonic acid.

(Production Example 2)
A solution prepared by dissolving 14.2 g of 3,4-ethylenedioxythiophene and 36.7 g of polystyrenesulfonic acid obtained in Production Example 1 in 2000 ml of ion-exchanged water was mixed at 20°C.
The obtained mixed solution was kept at 20° C., 29.64 g of ammonium persulfate dissolved in 200 ml of ion-exchanged water and 8.0 g of an oxidation catalyst solution of ferric sulfate were slowly added while stirring, and the mixture was stirred for 3 hours. Stir to react.
2000 ml of ion-exchanged water was added to the obtained reaction solution, and about 2000 ml solution was removed by the ultrafiltration method. This operation was repeated 3 times.
200 ml of sulfuric acid diluted to 10% by mass and 2000 ml of ion-exchanged water were added to the obtained solution, and about 2000 ml of the solvent was removed by the ultrafiltration method. 2000 ml of ion-exchanged water was added to the residual liquid, about 2000 ml of the solvent was removed by an ultrafiltration method, and polystyrene sulfonate-doped poly(3,4-ethylenedioxythiophene) (PEDOT-PSS) was washed with water. This operation was repeated 8 times to obtain 1.60% by mass of polystyrenesulfonic acid-doped poly(3,4-ethylenedioxythiophene) aqueous dispersion (PEDOT-PSS aqueous dispersion).

(Production Example 3)
After connecting the anode lead terminal to the etched aluminum foil (anode foil), a voltage of 130 V was applied in a 10% by mass aqueous solution of ammonium adipate to perform formation (oxidation treatment) to form a dielectric layer on both sides of the aluminum foil. It formed and obtained the anode foil.
Next, opposite aluminum cathode foils having cathode lead terminals welded to each other were laminated on both sides of the anode foil with a cellulose separator interposed therebetween, and this was wound into a cylindrical shape to obtain a capacitor element.

(Example 1)
To 100 parts by mass of the 1.60% by mass PEDOT-PSS aqueous dispersion obtained in Preparation Example 2, 5.0 parts by mass of commercially available arbutin (312.5 parts by mass with respect to 100 parts by mass of the conductive complex) was added. After stirring at room temperature, a dispersion treatment was performed using a high pressure disperser at a pressure of 100 MPa to obtain a conductive polymer dispersion liquid.
The step of immersing the capacitor element obtained in Production Example 3 in a conductive polymer dispersion under reduced pressure and then drying for 30 minutes with a hot air dryer at 125° C. is repeated twice to make the surface of the dielectric layer conductive. A solid electrolyte layer containing the composite was formed.
Then, the capacitor element having the solid electrolyte layer formed thereon was loaded in an aluminum case and sealed with a sealing rubber to obtain a capacitor.

(Comparative Example 1)
A capacitor was obtained in the same manner as in Example 1 except that arbutin was not added.
(Comparative example 2)
A capacitor was obtained in the same manner as in Example 1 except that arbutin was changed to glucose.

<Evaluation>
[Capacitance/Equivalent series resistance]
For the capacitors of Example 1 and Comparative Examples 1 and 2, using an LCR meter ZM2376 (manufactured by NF Circuit Design Block Co., Ltd.), a capacitance (C) at 120 Hz and an equivalent series resistance (ESR) at 100 kHz. Was measured. The measurement results are shown in Table 1.

The capacitor of Example 1 provided with the solid electrolyte layer containing the compound represented by the formula (1) had a sufficient capacitance, and the equivalent series resistance was significantly reduced.
The capacitor of Comparative Example 1 including the solid electrolyte layer containing no compound represented by the formula (1) had the same capacitance as that of Example 1, but the equivalent series resistance was larger than that of the example. ..
The capacitor of Comparative Example 2 including the solid electrolyte layer that did not contain the compound represented by the formula (1) had a smaller capacitance and a significantly larger equivalent series resistance than Example 1.

(Example 2)
100 parts by mass of the 1.60% by mass PEDOT-PSS aqueous dispersion obtained in Preparation Example 2, 0.3 parts by mass of imidazole (18.8 parts by mass with respect to 100 parts by mass of the conductive complex), and commercial arbutin After adding 5.0 parts by mass (312.5 parts by mass to 100 parts by mass of the conductive composite) and stirring at room temperature, a dispersion treatment was performed at a pressure of 100 MPa using a high pressure disperser to obtain a conductive polymer. A dispersion was obtained.
The step of immersing the capacitor element obtained in Production Example 3 in a conductive polymer dispersion under reduced pressure and then drying for 30 minutes with a hot air dryer at 125° C. is repeated twice to make the surface of the dielectric layer conductive. A solid electrolyte layer containing the composite was formed.
Then, the capacitor element having the solid electrolyte layer formed thereon was loaded in an aluminum case and sealed with a sealing rubber to obtain a capacitor.

(Example 3)
A capacitor was obtained in the same manner as in Example 2, except that the addition amount of imidazole was changed to 0.4 part by mass (25.0 parts by mass with respect to 100 parts by mass of the conductive composite).
(Example 4)
Further, a capacitor was obtained in the same manner as in Example 2 except that 8.0 parts by mass of diethylene glycol was added.
(Example 5)
A capacitor was obtained in the same manner as in Example 2 except that imidazole was changed to triethylamine and the addition amount was changed to 0.32 parts by mass (20.0 parts by mass with respect to 100 parts by mass of the conductive composite). ..

(Example 6)
A capacitor was obtained in the same manner as in Example 2 except that arbutin was changed to salicin and the addition amount was changed to 3.0 parts by mass.
(Example 7)
A capacitor was obtained in the same manner as in Example 2 except that arbutin was changed to salicin and the addition amount was changed to 5.0 parts by mass.
(Example 8)
A capacitor was prepared in the same manner as in Example 2 except that imidazole was changed to triethylamine, the addition amount was changed to 0.32 parts by mass, the arbutin was changed to salicin, and the addition amount was changed to 5.0 parts by mass. Obtained.

(Comparative example 3)
A capacitor was obtained in the same manner as in Example 2 except that arbutin was not added.
(Comparative Example 4)
A capacitor was obtained in the same manner as in Example 2 except that arbutin was changed to glucose.

<Evaluation>
[Capacitance/Equivalent series resistance]
For the capacitors of Examples 2 to 8 and Comparative Examples 3 to 4, using an LCR meter ZM2376 (manufactured by NF Circuit Design Block Co., Ltd.), the capacitance (C) at 120 Hz and the equivalent series resistance at 100 kHz ( ESR) was measured. The measurement results are shown in Table 2.

The capacitors of Examples 2 to 8 provided with the solid electrolyte layer containing the compound represented by the formula (1) and imidazole or triethylamine had a sufficient capacitance, and the equivalent series resistance was significantly reduced.
In addition, the capacitor of Example 4 to which diethylene glycol was added had a larger electrostatic capacitance than the capacitor of Example 2, and the equivalent series resistance was further reduced.
The capacitors of Comparative Examples 3 and 4 provided with the solid electrolyte layer containing no compound represented by the formula (1) had a smaller capacitance than the Examples and a larger equivalent series resistance than the Examples.

(Example 9)
To 100 parts by mass of the 1.60% by mass PEDOT-PSS aqueous dispersion obtained in Preparation Example 2, 5.0 parts by mass of commercially available arbutin (312.5 parts by mass with respect to 100 parts by mass of the conductive complex) was added. After stirring at room temperature, a dispersion treatment was performed using a high pressure disperser at a pressure of 100 MPa to obtain a conductive polymer dispersion liquid.
The step of immersing the capacitor element obtained in Production Example 3 in a conductive polymer dispersion under reduced pressure and then drying for 30 minutes with a hot air dryer at 125° C. is repeated twice to make the surface of the dielectric layer conductive. A solid electrolyte layer containing the composite was formed.
Next, an aluminum case was charged with a capacitor element having a solid electrolyte layer formed thereon and an electrolytic solution, sealed with a sealing rubber, and a voltage of 60 V was applied under an atmosphere of 120° C. to obtain a capacitor.

(Comparative example 5)
A capacitor was obtained in the same manner as in Example 9 except that arbutin was not added.
(Comparative example 6)
A capacitor was obtained in the same manner as in Example 9 except that arbutin was changed to glucose.

<Evaluation>
[Capacitance/Equivalent series resistance]
For the capacitors of Example 9 and Comparative Examples 5 and 6, using an LCR meter ZM2376 (manufactured by NF Circuit Design Block Co., Ltd.), a capacitance (C ₀ ) at 120 Hz and an equivalent series resistance (ESR) at 100 kHz were used. ₀ ) was measured. The measurement results are shown in Table 3.
[Heat resistance test]
The capacitors of Example 9 and Comparative Examples 5 and 6 were allowed to stand in a hot air dryer at 135° C., taken out after 500 hours had elapsed, and cooled at room temperature for 30 minutes. For the capacitor after cooling, the capacitance (C ₁ ) at 120 Hz and the equivalent series resistance (ESR ₁ ) at 100 kHz were measured using an LCR meter ZM2376 (manufactured by NF Circuit Design Block Co., Ltd.). The measurement results are shown in Table 3.
Further, ΔC=C ₁ /C ₀ and ΔESR=ESR ₁ /ESR ₀ were obtained as the change amounts before and after the heat resistance test. Table 3 also shows ΔC and ΔESR.

The capacitor of Example 9 including the solid electrolyte layer containing the compound represented by the formula (1) had a sufficient electrostatic capacity, and the equivalent series resistance was significantly reduced. The value of equivalent series resistance after the heat resistance test was also small. The value of ΔESR of Example 9 is larger than that of Comparative Examples 5 and 6, but ESR ₁ of Example 9 is sufficiently smaller than ESR ₀ and ESR ₁ of Comparative Examples 5 and 6, so The heat resistance of the capacitor of Example 9 is excellent.
The capacitors of Comparative Examples 5 and 6 provided with the solid electrolyte layer containing no compound represented by the formula (1) have the same capacitance as that of the example, but the equivalent series resistance is larger than that of the example. It was The value of equivalent series resistance after the heat resistance test was also large.

(Example 10)
100 parts by mass of the 1.60% by mass PEDOT-PSS aqueous dispersion obtained in Preparation Example 2, 0.3 parts by mass of imidazole (18.8 parts by mass with respect to 100 parts by mass of the conductive complex), and commercial arbutin After adding 5.0 parts by mass (312.5 parts by mass to 100 parts by mass of the conductive composite) and stirring at room temperature, a dispersion treatment was performed at a pressure of 100 MPa using a high pressure disperser to obtain a conductive polymer. A dispersion was obtained.
The step of immersing the capacitor element obtained in Production Example 3 in a conductive polymer dispersion under reduced pressure and then drying for 30 minutes with a hot air dryer at 125° C. is repeated twice to make the surface of the dielectric layer conductive. A solid electrolyte layer containing the composite was formed.
Next, an aluminum case was charged with a capacitor element having a solid electrolyte layer formed thereon and an electrolytic solution, sealed with a sealing rubber, and a voltage of 60 V was applied under an atmosphere of 120° C. to obtain a capacitor.

(Example 11)
A capacitor was obtained in the same manner as in Example 10 except that the addition amount of imidazole was changed to 0.4 part by mass (25.0 parts by mass with respect to 100 parts by mass of the conductive composite).
(Example 12)
Further, a capacitor was obtained in the same manner as in Example 10 except that 8.0 parts by mass of diethylene glycol was added.
(Example 13)
A capacitor was obtained in the same manner as in Example 10 except that imidazole was changed to triethylamine and the addition amount was changed to 0.32 parts by mass (20.0 parts by mass with respect to 100 parts by mass of the conductive composite). ..

(Example 14)
A capacitor was obtained in the same manner as in Example 10 except that arbutin was changed to salicin and the addition amount was changed to 3.0 parts by mass.
(Example 15)
A capacitor was obtained in the same manner as in Example 10 except that arbutin was changed to salicin and the addition amount was changed to 5.0 parts by mass.
(Example 16)
A capacitor was prepared in the same manner as in Example 10 except that imidazole was changed to triethylamine, the addition amount was changed to 0.32 parts by mass, the arbutin was changed to salicin, and the addition amount was changed to 5.0 parts by mass. Obtained.

(Comparative Example 7)
A capacitor was obtained in the same manner as in Example 10 except that arbutin was not added.
(Comparative Example 8)
A capacitor was obtained in the same manner as in Example 10 except that arbutin was changed to glucose.

<Evaluation>
[Capacitance/Equivalent series resistance]
Regarding the capacitors of Examples 10 to 16 and Comparative Examples 7 and 8, using an LCR meter ZM2376 (manufactured by NF Circuit Design Block Co., Ltd.), a capacitance (C ₀ ) at 120 Hz and an equivalent series resistance at 100 kHz were used. (ESR ₀ ) was measured. The measurement results are shown in Table 4.
[Heat resistance test]
The capacitors of Examples 10 to 16 and Comparative Examples 7 and 8 were allowed to stand in a hot air dryer at 135° C., taken out after 500 hours had elapsed, and cooled at room temperature for 30 minutes. For the capacitor after cooling, the capacitance (C ₁ ) at 120 Hz and the equivalent series resistance (ESR ₁ ) at 100 kHz were measured using an LCR meter ZM2376 (manufactured by NF Circuit Design Block Co., Ltd.). The measurement results are shown in Table 4.
Further, ΔC=C ₁ /C ₀ and ΔESR=ESR ₁ /ESR ₀ were obtained as the change amounts before and after the heat resistance test. Table 4 also shows ΔC and ΔESR.

The capacitors of Examples 10 to 16 provided with the solid electrolyte layer containing the compound represented by the formula (1) and imidazole or triethylamine had a sufficient capacitance, and the equivalent series resistance was significantly reduced. The value of equivalent series resistance after the heat resistance test was also small. Although the value of ΔESR of Example 11 is larger than that of Comparative Examples 7 and 8, ESR _{1 of} Example 11 is sufficiently smaller than ESR ₁ of Comparative Examples 7 and 8, so that The heat resistance of the capacitor is excellent. Although the value of ΔESR of Example 15 is larger than that of Comparative Example 7, ESR _{1 of} Example 15 is sufficiently smaller than ESR ₁ of Comparative Example 7, so that the heat resistance of the capacitor of Example 15 is excellent. ..
The capacitors of Comparative Examples 7 and 8 provided with the solid electrolyte layer not containing the compound represented by the formula (1) have the same capacitance as that of the example, but the equivalent series resistance is larger than that of the example. It was The value of equivalent series resistance after the heat resistance test was also large.

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

Claims (19)

A conductive polymer dispersion liquid containing a conductive complex containing a π-conjugated conductive polymer and a polyanion, at least one compound represented by the following formula (1), and a dispersion medium.

[In the formula (1), R _{1 to} R ₅ each independently represent a hydrogen atom or any substituent, and m represents an integer of 1 to 5. ] In the compound represented by the formula (1), each of R _{1 to} R ₄ is a hydrogen atom, and at least one of R ₅ is a hydroxy group or the following formula (2A), formula (2B) or formula (2B). The electroconductive polymer dispersion liquid according to claim 1, which contains a compound which is a substituent represented by 2C).
_{- (CH 2) n1 -OH ···} (2A)
_{- (CH 2) n2 -H ···} (2B)
_{-O- (CH 2) n3 -H ···} (2C)
[In Formula (2A), Formula (2B), and Formula (2C), n1, n2, and n3 represent the integer of 1-3 each independently. ] The conductive polymer dispersion liquid according to claim 1, wherein the compound represented by the formula (1) contains at least one of arbutin and salicin. The conductive polymer dispersion liquid according to claim 1, further containing at least one of a nitrogen-containing aromatic cyclic compound and a tertiary amine. The conductive polymer dispersion liquid according to claim 4, which contains the nitrogen-containing aromatic cyclic compound, and the nitrogen-containing aromatic cyclic compound contains imidazole. The conductive polymer dispersion liquid according to claim 4, which contains the tertiary amine, and the tertiary amine contains triethylamine. The electroconductive polymer dispersion liquid according to claim 1, further comprising at least one kind of compound having two or more hydroxy groups different from the compound represented by the formula (1). The conductive polymer dispersion liquid according to claim 1, wherein the π-conjugated conductive polymer is poly(3,4-ethylenedioxythiophene). The electroconductive polymer dispersion liquid according to claim 1, wherein the polyanion is polystyrene sulfonic acid. An anode made of a porous body of a valve metal, a dielectric layer made of an oxide of the valve metal, a cathode made of a conductive material provided on the side of the dielectric layer opposite to the anode, and the dielectric layer. And a solid electrolyte layer formed between the cathode, wherein the solid electrolyte layer is a conductive complex containing a π-conjugated conductive polymer and a polyanion, and a compound represented by the following formula (1): A capacitor having at least one of

[In the formula (1), R _{1 to} R ₅ each independently represent a hydrogen atom or any substituent, and m represents an integer of 1 to 5. ] In the compound represented by the formula (1), each of R _{1 to} R ₄ is a hydrogen atom, and at least one of R ₅ is a hydroxy group or the following formula (2A), formula (2B) or formula (2B). The capacitor according to claim 10, which contains a compound which is a substituent represented by 2C).
_{- (CH 2) n1 -OH ···} (2A)
_{- (CH 2) n2 -H ···} (2B)
_{-O- (CH 2) n3 -H ···} (2C)
[In Formula (2A), Formula (2B), and Formula (2C), n1, n2, and n3 represent the integer of 1-3 each independently. ] The capacitor according to claim 10, wherein the compound represented by the formula (1) contains at least one of arbutin and salicin. The capacitor according to claim 10 or 11, wherein the solid electrolyte layer further contains at least one of a nitrogen-containing aromatic cyclic compound and a tertiary amine. 14. The capacitor according to claim 13, which contains the nitrogen-containing aromatic cyclic compound, and the nitrogen-containing aromatic cyclic compound contains imidazole. 14. The capacitor according to claim 13, wherein the capacitor contains the tertiary amine, and the tertiary amine contains triethylamine. The capacitor according to any one of claims 10 to 15, wherein the solid electrolyte layer further contains at least one kind of compound having two or more hydroxy groups, which is different from the compound represented by the formula (1). .. The capacitor according to claim 10, wherein the π-conjugated conductive polymer is poly(3,4-ethylenedioxythiophene). 18. The capacitor according to claim 10, wherein the polyanion is polystyrene sulfonic acid. A step of oxidizing the surface of the anode made of a porous body of valve metal to form a dielectric layer;
A step of disposing a cathode at a position facing the dielectric layer, and applying the conductive polymer dispersion liquid according to any one of claims 1 to 9 to the surface of the dielectric layer, followed by drying to obtain a solid. And a step of forming an electrolyte layer.

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