JP6614927B2 - Capacitor and manufacturing method thereof - Google Patents

Description

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

As a capacitor, a capacitor in which an equivalent series resistance is reduced by using a solid electrolyte layer containing a conductive polymer as an electrolyte disposed between a dielectric layer and a cathode is known.
As the solid electrolyte layer containing a conductive polymer, a layer formed from a conductive polymer dispersion containing poly (3,4-ethylenedioxythiophene) and polystyrene sulfonic acid may be used (for example, patent document). 1).

JP 2014-67949 A

Electronic devices are required to have further improved performance and downsizing, while capacitors are required to have a smaller equivalent series resistance.
Therefore, an object of the present invention is to provide a capacitor having a sufficiently small equivalent series resistance and a method for manufacturing the same.

[1] 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 opposite side of the dielectric layer from the anode, A solid electrolyte layer formed between a dielectric layer and the cathode, wherein the solid electrolyte layer includes a conductive composite containing a π-conjugated conductive polymer and a polyanion, and an amine having a polyalkylene oxide structure. A capacitor containing a compound.
[2] The capacitor according to [1], wherein the amine compound is a compound represented by the following formula (1).
(In the formula, R ¹ , R ² , and R ³ are each an alkylene group. Ma, mb, and mc are each an integer of 1 or more and 4 or less. Na, nb, and nc are 1 or more and 4 or less, respectively. (P, q, r are each integers greater than or equal to 0. s, t, u are each integers greater than or equal to 0 and less than or equal to 3, and s + t + u = 3.)

[3] The capacitor according to [2], wherein the amine compound is tris [(2-methoxyethoxy) ethyl] amine.
[4] The capacitor according to any one of [1] to [3], wherein the π-conjugated conductive polymer is poly (3,4-ethylenedioxythiophene).
[5] The capacitor according to any one of [1] to [4], wherein the polyanion is polystyrene sulfonic acid.
[6] A step of oxidizing a surface of an anode made of a porous body of a valve metal to form a dielectric layer, a step of forming a cathode at a position facing the dielectric layer, and a surface having high conductivity on the surface of the dielectric layer. A step of applying a molecular dispersion and drying to form a solid electrolyte layer. As the conductive polymer dispersion, a conductive complex containing a π-conjugated conductive polymer and a polyanion, and a polyalkylene A method for producing a capacitor, comprising using an amine compound having an oxide structure and a dispersion medium.
[7] The method for producing a capacitor according to [6], wherein the amine compound is a compound represented by the above formula (1).
[8] The method for producing a capacitor according to [7], wherein the amine compound is tris [(2-methoxyethoxy) ethyl] amine.
[9] The method for producing a capacitor according to any one of [6] to [8], wherein the pH of the conductive polymer dispersion at 25 ° C. is from 2.00 to 10.00.
[10] The method for producing a capacitor according to any one of [6] to [9], wherein the π-conjugated conductive polymer is poly (3,4-ethylenedioxythiophene).
[11] The method for producing a capacitor according to any one of [6] to [10], wherein the polyanion is polystyrene sulfonic acid.

The capacitor of the present invention has a sufficiently small equivalent series resistance.
According to the method for manufacturing a capacitor of the present invention, a capacitor having a sufficiently small equivalent series resistance can be easily manufactured.

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

<Capacitor>
One embodiment of the capacitor of the present invention will be described.
As shown in FIG. 1, the capacitor 10 of this embodiment is formed on the surface of the anode 11 made of a porous body of the valve metal, the dielectric layer 12 made of the oxide of the valve metal, and the dielectric layer 12. The solid electrolyte layer 13 and the cathode 14 provided on the most front side are provided.

Examples of the valve metal constituting 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. What was processed in this way 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 anode 11 of the metal body is anodized in an electrolytic solution such as an aqueous solution of ammonium adipate. It is formed by. Therefore, as shown in FIG. 1, the dielectric layer 12 is uneven as in the anode 11.

  As the cathode 14 in this embodiment, a metal layer made of a conductive material such as a conductive layer formed from a conductive paste or an aluminum foil can be used.

The solid electrolyte layer 13 is a layer containing a conductive complex including a π-conjugated conductive polymer and a polyanion, and an amine compound having a polyalkylene oxide structure.
The thickness of the solid electrolyte layer 13 does not need to be constant, and may be in the range of 1 μm to 100 μm, for example.

  The π-conjugated conductive polymer contained in the solid electrolyte layer 13 is not particularly limited as long as it has the effect of the present invention as long as the main chain is an organic polymer composed of a π-conjugated system. Conductive polymer, polythiophene conductive polymer, polyacetylene conductive polymer, polyphenylene conductive polymer, polyphenylene vinylene conductive polymer, polyaniline conductive polymer, polyacene conductive polymer, polythiophene vinylene System-based conductive polymers, and copolymers thereof. From the viewpoint of stability in air, polypyrrole-based conductive polymers, polythiophenes and polyaniline-based conductive polymers are preferable, and polythiophene-based conductive polymers are more preferable from the viewpoint of conductivity and transparency.

Examples of the polythiophene-based conductive polymer include polythiophene, poly (3-methylthiophene), poly (3-ethylthiophene), poly (3-propylthiophene), poly (3-butylthiophene), and poly (3-hexylthiophene). , Poly (3-heptylthiophene), poly (3-octylthiophene), poly (3-decylthiophene), poly (3-dodecylthiophene), poly (3-octadecylthiophene), poly (3-bromothiophene), poly (3-chlorothiophene), poly (3-iodothiophene), poly (3-cyanothiophene), poly (3-phenylthiophene), poly (3,4-dimethylthiophene), poly (3,4-dibutylthiophene) , Poly (3-hydroxythiophene), poly (3-methoxythiophene), poly ( -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-diethoxythiophene), poly ( 3,4-dipropoxythiophene), poly (3,4-dibutoxythiophene), poly (3,4-dihexyloxythiophene), poly (3,4-diheptyloxythiophene), poly (3,4-dioctyl) Oxythiophene), poly (3,4-didecyloxythiophene), poly (3, -Didodecyloxythiophene), poly (3,4-ethylenedioxythiophene), poly (3,4-propylenedioxythiophene), poly (3,4-butenedioxythiophene), poly (3-methyl-4 -Methoxythiophene), poly (3-methyl-4-ethoxythiophene), poly (3-carboxythiophene), poly (3-methyl-4-carboxythiophene), poly (3-methyl-4-carboxyethylthiophene), Poly (3-methyl-4-carboxybutylthiophene) is mentioned.
Examples of the polypyrrole conductive polymer include polypyrrole, poly (N-methylpyrrole), poly (3-methylpyrrole), poly (3-ethylpyrrole), poly (3-n-propylpyrrole), and poly (3-butyl Pyrrole), poly (3-octylpyrrole), poly (3-decylpyrrole), poly (3-dodecylpyrrole), poly (3,4-dimethylpyrrole), poly (3,4-dibutylpyrrole), poly (3 -Carboxypyrrole), poly (3-methyl-4-carboxypyrrole), poly (3-methyl-4-carboxyethylpyrrole), poly (3-methyl-4-carboxybutylpyrrole), poly (3-hydroxypyrrole) , Poly (3-methoxypyrrole), poly (3-ethoxypyrrole), poly (3-butoxypyrrole), poly (3-hexyl) Oxy pyrrole), poly (3-methyl-4-hexyloxy-pyrrole) and the like.
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, poly (3,4-ethylenedioxythiophene) is particularly preferable because of higher conductivity, transparency, and heat resistance.
The π-conjugated conductive polymer may be used alone or in combination of two or more.

The polyanion contained in the solid electrolyte layer 13 is a polymer having two or more monomer units having an anion group in the molecule. The anion group of the polyanion functions as a dopant for the π-conjugated conductive polymer and improves 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 such polyanions include polystyrene sulfonic acid, polyvinyl sulfonic acid, polyallyl sulfonic acid, polyacryl sulfonic acid, polymethacryl sulfonic acid, poly (2-acrylamido-2-methylpropane sulfonic acid), polyisoprene sulfone. Polymers having a sulfonic acid group such as acid, polysulfoethyl methacrylate, poly (4-sulfobutyl methacrylate), polymethacryloxybenzenesulfonic acid, polyvinyl carboxylic acid, polystyrene carboxylic acid, polyallyl carboxylic acid, polyacryl carboxylic acid , Polymers having a carboxylic acid group such as polymethacrylcarboxylic acid, poly (2-acrylamido-2-methylpropanecarboxylic acid), polyisoprene carboxylic acid, polyacrylic acid and the like. These homopolymers may be sufficient and 2 or more types of copolymers may be sufficient.
Among these polyanions, a polymer having a sulfonic acid group is preferable, and polystyrene sulfonic acid is more preferable because conductivity can be further increased.
The said polyanion may be used individually by 1 type, and may use 2 or more types together.
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 in the present specification is a value obtained by measuring with gel permeation chromatography and obtaining the standard substance as polystyrene.

  The content ratio of the polyanion in the conductive composite is preferably in the range of 1 part by mass to 1000 parts by mass with respect to 100 parts by mass of the π-conjugated conductive polymer, and 10 parts by mass to 700 parts by mass. It is more preferable that it is in the range of 100 parts by mass or more and 500 parts by mass or less. If the polyanion content is less than the lower limit, the doping effect on the π-conjugated conductive polymer tends to be weak, the conductivity may be insufficient, and the conductivity in the conductive polymer dispersion may be insufficient. The dispersibility of the sex complex decreases. On the other hand, when the content of the polyanion exceeds the upper limit, the content of the π-conjugated conductive polymer is decreased, and it is difficult to obtain sufficient conductivity.

The polyanion is coordinated and doped to the π-conjugated conductive polymer to form a conductive composite.
However, in the polyanion in this embodiment, not all anion groups are doped into the π-conjugated conductive polymer, but have excess anion groups that do not contribute to doping. Since the surplus anionic group has high hydrophilicity, it plays a role of improving the water dispersibility of the conductive composite.

The amine compound contained in the solid electrolyte layer 13 is an amine having a polyalkylene oxide structure, and examples thereof include polyoxyethylene oleylamine, polyoxyethylene stearylamine, and polyoxyethylene laurylamine.
Particularly preferred is a compound represented by the formula (1).
Since this amine compound coordinates or adds to the anion of the polyanion, the acidity of the conductive polymer aqueous dispersion can be weakened.
In the formula (1), R ¹ , R ² and R ³ are each an alkylene group, preferably an alkylene group having 1 to 4 carbon atoms. Examples of the alkylene group having 1 to 4 carbon atoms include a methylene group, an ethylene group, a propylene group, and a butylene group, and among them, a methylene group or an ethylene group is more preferable. The alkylene groups for R ¹ , R ² and R ³ may all be the same, or any one of them may be different or all may be different.
ma, mb, and mc are each an integer of 1 to 4, and 1 or 2 is preferable. The numerical values of ma, mb, and mc may all be the same, any one may be different, or all may be different.
na, nb and nc are each an integer of 1 or more and 4 or less, preferably 1 or 2. The numerical values of na, nb, and nc may all be the same, any one may be different, or all may be different.
p, q, and r are each an integer of 0 or more, preferably 0 or more and 3 or less.
Each of s, t, and u is an integer of 0 to 3, and s + t + u = 3.

Among the amine compounds, R ¹ , R ² , R ³ are ethylene groups, ma, mb, mc is 2, na, nb, nc is 1, p, q, r is 1, tris [2- (2 -Methoxyethoxy) ethyl] amine is preferred. If tris [2- (2-methoxyethoxy) ethyl] amine is used as the amine compound, the equivalent series resistance of the capacitor 1 can be further reduced.

The content of the amine compound in the solid electrolyte layer 13 is preferably 30 parts by mass or more and 2000 parts by mass or less with respect to 100 parts by mass of the conductive composite. In particular, when the amine compound is tris [2- (2-methoxyethoxy) ethyl] amine, the content of the amine compound is 50 parts by mass or more and 2000 parts by mass or less with respect to 100 parts by mass of the conductive composite. It is preferable that it is 70 mass parts or more and 800 mass parts or less.
If the content of the amine compound is within the above range, the equivalent series resistance can be sufficiently reduced. However, if the amine compound content is less than the lower limit value, the amine compound content is small and the equivalent series resistance may not be sufficiently reduced. If the upper limit value is exceeded, polyanion de-doping occurs. The equivalent series resistance may not be made sufficiently small.

The solid electrolyte layer 13 may contain an electrolytic solution. The electrolytic solution is not particularly limited as long as the electric conductivity is high, and examples include an electrolyte dissolved in a solvent for the electrolytic solution.
Examples of the electrolyte solution solvent include alcohol solvents such as ethylene glycol, diethylene glycol, propylene glycol, 1,4-butanediol, and glycerin; lactone solvents such as γ-butyrolactone, γ-valerolactone, and δ-valerolactone; Examples thereof include amide solvents such as N-methylformamide, N, N-dimethylformamide, N-methylacetamide and N-methylpyrrolidinone, nitrile solvents such as acetonitrile and 3-methoxypropionitrile, water and the like.
Examples of the electrolyte include adipic acid, glutaric acid, succinic acid, benzoic acid, isophthalic acid, phthalic acid, terephthalic acid, maleic acid, toluic acid, enanthic acid, malonic acid, formic acid, 1,6-decanedicarboxylic acid, 5,6 -Decane dicarboxylic acid such as decanedicarboxylic acid, octane dicarboxylic acid such as 1,7-octane dicarboxylic acid, organic acid such as azelaic acid and sebacic acid, or boric acid, polyhydric alcohol of boric acid obtained from boric acid and polyhydric alcohol Complex compounds, inorganic acids such as phosphoric acid, carbonic acid, and silicic acid are used as anionic components, and primary amines (methylamine, ethylamine, propylamine, butylamine, ethylenediamine, etc.), secondary amines (dimethylamine, diethylamine, dipropylamine, Methylethylamine, diphenylamine, etc.), tertiary amine (trimethyl) Amine, triethylamine, tripropylamine, triphenylamine, 1,8-diazabicyclo (5,4,0) -undecene-7, etc.), tetraalkylammonium (tetramethylammonium, tetraethylammonium, tetrapropylammonium, tetrabutylammonium, Examples thereof include electrolytes containing methyltriethylammonium, dimethyldiethylammonium, etc.) as cationic components.

The solid electrolyte layer 13 may contain a known additive.
The additive is not particularly limited as long as it has the effect of the present invention, and for example, a surfactant, an inorganic conductive agent, an antifoaming agent, a coupling agent, an antioxidant, an ultraviolet absorber and the like can be used. However, an additive consists of compounds other than the said polyanion and the said amine compound.
Examples of the surfactant include nonionic, anionic and cationic surfactants, and nonionic surfactants are preferred from the viewpoint of storage stability. Moreover, you may add polymer type surfactants, such as polyvinyl alcohol and polyvinylpyrrolidone.
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 antifoaming agent include silicone resin, polydimethylsiloxane, and silicone oil.
Examples of the coupling agent include silane coupling agents having a vinyl group, an amino group, an epoxy group, and the like.
Examples of the antioxidant include phenolic antioxidants, amine antioxidants, phosphorus antioxidants, sulfur antioxidants, saccharides, vitamins and the like.
Examples of UV absorbers include benzotriazole UV absorbers, benzophenone UV absorbers, salicylate UV absorbers, cyanoacrylate UV absorbers, oxanilide UV absorbers, hindered amine UV absorbers, and benzoate UV absorbers. Is mentioned.

  The capacitor of the present embodiment can be manufactured by, for example, a capacitor manufacturing method including a dielectric layer forming step, a cathode forming step, and a solid electrolyte layer forming step.

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 porous body of valve metal.
Examples of the method for forming the dielectric layer 12 include a method in which the surface of the anode 11 is anodized in an electrolytic solution for chemical conversion treatment such as an aqueous solution of ammonium adipate, an aqueous solution of ammonium borate, or an aqueous solution of ammonium phosphate. .

The cathode forming step is a step of forming the cathode 14 at a position facing the dielectric layer 12.
Examples of the method of forming the cathode 14 include a method of forming the cathode 14 using a conductive paste such as carbon paste and silver paste, and a method of disposing a metal foil such as an aluminum foil opposite to the dielectric layer 12. It is done.

The solid electrolyte layer forming step is a step in which a conductive polymer dispersion is applied to the surface of the dielectric layer 12 and dried to form the solid electrolyte layer 13.
Here, the conductive polymer dispersion contains a conductive complex including a π-conjugated conductive polymer and a polyanion, the amine compound, and a dispersion medium.

The dispersion medium contained in the conductive polymer dispersion is a liquid for dispersing the conductive composite, and is water, an organic solvent, or a mixed liquid of water and an organic solvent.
Examples of organic solvents include ketone solvents such as diethyl ketone, methyl propyl ketone, methyl butyl ketone, methyl isopropyl ketone, methyl isobutyl ketone, methyl amyl ketone, diisopropyl ketone, methyl ethyl ketone, acetone, diacetone alcohol; diethyl ether, dimethyl ether, ethylene Ether solvents such as glycol, propylene glycol, propylene glycol monoalkyl ether, propylene glycol dialkyl ether; ester solvents such as ethyl acetate, propyl acetate, butyl acetate; benzene, toluene, xylene, ethylbenzene, propylbenzene, isopropylbenzene, etc. Aromatic solvents: ethanol, propanol, isopropanol, n-butanol, t-butanol, allyl alcohol Alcohol solvents such Lumpur; N- methylpyrrolidone, dimethylacetamide, amide solvents such as dimethylformamide, including without being limited to the above. These organic solvents may be used individually by 1 type, and may use 2 or more types together.

  The content ratio of the dispersion medium in the conductive polymer dispersion is preferably 50% by mass to 90% by mass, and preferably 70% by mass to 90% by mass with respect to 100% by mass of the total mass of the conductive polymer dispersion. % Or less is more preferable. If the content ratio of the dispersion medium is equal to or higher than the lower limit value, each component can be easily dispersed to improve coatability. If the content ratio is equal to or lower than the upper limit value, the solid content concentration is increased. Thickness can be easily secured by one-time coating.

The pH of the conductive polymer dispersion at 25 ° C. is preferably in the range of 2.00 to 10.00, and preferably in the range of 3.00 to 10.00. If a conductive polymer dispersion having a pH within the above range is used, the equivalent series resistance of the capacitor can be further reduced.
In order to achieve the above pH, the amine compound content is preferably 30 parts by mass or more and 2000 parts by mass or less with respect to 100 parts by mass of the conductive composite. In particular, when the amine compound is tris [2- (2-methoxyethoxy) ethyl] amine, the content of the amine compound is 50 parts by mass or more and 2000 parts by mass or less with respect to 100 parts by mass of the conductive composite. It is preferable that it is 70 mass parts or more and 800 mass parts or less.

  As a method for preparing a conductive polymer dispersion, there is a method in which an amine compound and an additive are added after oxidative polymerization of a precursor monomer that forms a π-conjugated conductive polymer in the presence of a polyanion and a dispersion medium. Can be mentioned.

As a method for applying the conductive polymer dispersion, for example, dipping (that is, dip coating), comma coating, reverse coating, lip coating, micro gravure coating, or the like can be applied. Among these, immersion is preferable in that the solid electrolyte layer 13 can be easily formed between the dielectric layer 12 and the cathode 14.
Examples of the drying method include known methods such as room temperature drying, hot air drying, and far-infrared drying.

In order to reduce the equivalent series resistance of the capacitor 10, the present inventors examined a compound added to the conductive composite, particularly an amine compound. As a result, it was found that the equivalent series resistance of the capacitor 10 becomes sufficiently small when the solid electrolyte layer 13 contains an amine compound having a polyalkylene oxide structure in addition to the conductive composite.
Further, even if the equivalent series resistance is reduced by containing an amine compound having a polyalkylene oxide structure, the capacitance of the capacitor 1 is not reduced.

The capacitor of the present invention and the manufacturing method thereof are not limited to the above embodiment.
For example, in the capacitor of the present invention, a separator may be provided between the dielectric layer and the cathode as necessary. Examples of the capacitor in which a separator is provided between the dielectric layer and the cathode include 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 more preferably it is 0.1 g / cm ³ or more 1.0 g / cm ³ or less in the range is preferable, 0.2 g / cm ³ or more 0.8 g / cm ³ or less.
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.

(Production Example 1)
Dissolve 206 g of sodium styrenesulfonate in 1000 ml of ion-exchanged water and, while stirring at 80 ° C., add dropwise 1.14 g of ammonium persulfate oxidizer solution previously dissolved in 10 ml of water for 20 minutes. Stir.
To the obtained sodium styrenesulfonate-containing solution, 1000 ml of sulfuric acid diluted to 10% by mass was added, about 1000 ml of the polystyrenesulfonic acid-containing solution was removed by ultrafiltration, and 2000 ml of ion-exchanged water was added to the remaining liquid. About 2000 ml of solution was removed by ultrafiltration. The above ultrafiltration operation was repeated three times. Further, about 2000 ml of ion-exchanged water was added to the obtained filtrate, and about 2000 ml of the solution was removed by ultrafiltration. This ultrafiltration operation was repeated three times.
Water in the obtained solution was removed under reduced pressure to obtain colorless solid polystyrene sulfonic acid.

(Production Example 2)
A solution prepared by dissolving 14.2 g of 3,4-ethylenedioxythiophene and 36.7 g of the polystyrene sulfonic acid obtained in Production Example 1 in 2000 ml of ion-exchanged water was mixed at 20 ° C.
While maintaining the mixed solution thus obtained at 20 ° C. and stirring, 29.64 g of ammonium persulfate dissolved in 200 ml of ion exchange water and 8.0 g of ferric sulfate oxidation catalyst solution were slowly added, The reaction was stirred for 3 hours.
2000 ml of ion-exchanged water was added to the obtained reaction solution, and about 2000 ml of solution was removed by ultrafiltration. This operation was repeated three times.
Then, 200 ml of sulfuric acid diluted to 10% by mass and 2000 ml of ion-exchanged water are added to the resulting solution, about 2000 ml of solution is removed by ultrafiltration, and 2000 ml of ion-exchanged water is added to this solution. About 2000 ml of solution was removed by external filtration. This operation was repeated three times.
Furthermore, 2000 ml of ion-exchanged water was added to the obtained solution, and about 2000 ml of the solution was removed by ultrafiltration. This operation was repeated 5 times to obtain 1.40% by mass of a 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 an aqueous solution of 10% by weight ammonium adipate to form (oxidize) the dielectric layer on both sides of the aluminum foil. An anode foil was obtained by forming.
Next, on both surfaces of the anode foil, an opposing aluminum cathode foil with cathode lead terminals welded was laminated via a cellulose separator, and this was wound into a cylindrical shape to obtain a capacitor element.

Example 1
To 100 g of the 1.40 mass% PEDOT-PSS aqueous dispersion obtained in Production Example 2, 1.015 g of tris [(2-methoxyethoxy) ethyl] amine (72.5 mass relative to 100 mass parts of the conductive composite). Part) and stirred at room temperature, and then subjected to a dispersion treatment at a pressure of 100 MPa using a high-pressure disperser to obtain a conductive polymer dispersion. The pH of the conductive polymer dispersion at 25 ° C. was measured by a pH meter D-54 (manufactured by Horiba, Ltd.) and found to be 2.42.
After immersing the capacitor element obtained in Production Example 3 in a conductive polymer dispersion under reduced pressure, the process of drying with a hot air dryer at 125 ° C. for 30 minutes was repeated twice to make the conductive element conductive on the surface of the dielectric layer. A solid electrolyte layer containing the composite was formed.
Next, a capacitor element having a solid electrolyte layer formed thereon was loaded into an aluminum case and sealed with a sealing rubber to obtain a capacitor.

(Example 2)
A capacitor was obtained in the same manner as in Example 1 except that the amount of tris [(2-methoxyethoxy) ethyl] amine was changed to 1.679 g (119.8 parts by mass with respect to 100 parts by mass of the conductive composite). .

(Example 3)
A capacitor was obtained in the same manner as in Example 1 except that the amount of tris [(2-methoxyethoxy) ethyl] amine was changed to 1.393 g (99.5 parts by mass with respect to 100 parts by mass of the conductive composite). .

Example 4
A capacitor was obtained in the same manner as in Example 1 except that the amount of tris [(2-methoxyethoxy) ethyl] amine was changed to 10.021 g (715.8 parts by mass with respect to 100 parts by mass of the conductive composite). .

(Comparative Example 1)
A capacitor was obtained in the same manner as in Example 1 except that 1.015 g of tris [(2-methoxyethoxy) ethyl] amine was changed to 0.220 g of imidazole (15.7 parts by mass with respect to 100 parts by mass of the conductive composite). Obtained.

(Comparative Example 2)
A capacitor was obtained in the same manner as in Example 1 except that 1.015 g of tris [(2-methoxyethoxy) ethyl] amine was changed to 0.352 g of imidazole (25.1 parts by mass with respect to 100 parts by mass of the conductive composite). Obtained.

(Comparative Example 3)
A capacitor was obtained in the same manner as in Example 1 except that 1.015 g of tris [(2-methoxyethoxy) ethyl] amine was changed to 0.337 g of triethylamine (24.1 parts by mass with respect to 100 parts by mass of the conductive composite). Obtained.

(Comparative Example 4)
A capacitor was obtained in the same manner as in Example 1 except that 1.015 g of tris [(2-methoxyethoxy) ethyl] amine was changed to 0.515 g of triethylamine (36.8 parts by mass with respect to 100 parts by mass of the conductive composite). Obtained.

(Comparative Example 5)
A capacitor was obtained in the same manner as in Example 1 except that tris [(2-methoxyethoxy) ethyl] amine was not added.

<Evaluation>
About the obtained capacitor of each example, the electrostatic capacitance in 120 Hz and the equivalent series resistance (ESR) in 100 kHz were measured using LCR meter ZM2376 (made by NF circuit design block). Table 1 shows the measurement results of capacitance at 120 Hz and ESR at 100 kHz.

The capacitors of Examples 1 to 4 in which the solid electrolyte layer was formed using a conductive polymer dispersion containing an amine compound having a polyalkylene oxide structure had a low ESR and sufficient capacitance. .
The capacitors of Comparative Examples 1 to 4 in which the solid electrolyte layer was formed using the conductive polymer dispersion containing the amine compound having no polyalkylene oxide structure had a large ESR.
The capacitor of Comparative Example 5 in which the solid electrolyte layer was formed using a conductive polymer dispersion containing no amine compound had a large ESR.

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

Claims (7)

An anode made of a porous body of valve metal, a dielectric layer made of an oxide of the valve metal, a cathode made of a conductive material provided on the opposite side of the dielectric layer from the anode, and the dielectric layer And a solid electrolyte layer formed between the cathodes,
The capacitor in which the solid electrolyte layer contains a conductive complex containing a π-conjugated conductive polymer and a polyanion, and tris [( 2-methoxyethoxy) ethyl] amine.   The capacitor according to claim 1, wherein the π-conjugated conductive polymer is poly (3,4-ethylenedioxythiophene).   The capacitor according to claim 1, wherein the polyanion is polystyrene sulfonic acid. Oxidizing the surface of the anode made of a porous body of valve metal to form a dielectric layer;
Forming a cathode at a position facing the dielectric layer;
Applying a conductive polymer dispersion to the surface of the dielectric layer and drying to form a solid electrolyte layer;
Capacitor that uses a conductive complex containing a π-conjugated conductive polymer and a polyanion, tris [( 2-methoxyethoxy) ethyl] amine, and a dispersion medium as the conductive polymer dispersion Manufacturing method.   The method for producing a capacitor according to claim 4, wherein the pH of the conductive polymer dispersion at 25 ° C. is 2.00 or more and 10.00 or less.   The method for producing a capacitor according to claim 4, wherein the π-conjugated conductive polymer is poly (3,4-ethylenedioxythiophene).   The method for producing a capacitor according to claim 4, wherein the polyanion is polystyrene sulfonic acid.

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