JP2001023437A - Polyaniline paste, manufacture of solid electrolytic capacitor using it and solid electrolyte capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide conductivity for a film only by applying and drying to form the film suitable for a use as electrolyte and the like by comprising conductive polyaniline grain, polyamide polymer and a solvent. SOLUTION: In preparation of a conductive poly aniline compound constituting conductive polyaniline grain, a non-conductive polyaniline compound is washed with water and/or an organic solvent as necessary, and then, washed with alkaline for eliminating dopants once, and the washed compound is doped with acid and the like for providing conductivity. The conductive polyaniline grain is mixed with a solvent and stirred for preparing poly aniline paste. This poly aniline paste is applied onto a substrate such as a glass plate, and a dried coating film shows conductivity of 0.3 S/cm or more. As the acid used for the dopant in the conductive polyaniline grain, organic sulfonic acid is desirable.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polyaniline paste, a method for manufacturing a solid electrolytic capacitor using the same, and a solid electrolytic capacitor.

[0002]

2. Description of the Related Art A conventional solid electrolytic capacitor uses a tantalum pellet called a valve metal or a molded body obtained by enlarging aluminum as an anode body, forms an oxide film on the surface thereof to form a dielectric, and forms manganese dioxide or manganese dioxide. , 7 ', 8, 8'-tetracyanoquinodimethane complex salt (TCNQ) or the like as an electrolyte layer. However, since manganese dioxide (MnO ₂ ) has an insufficient conductivity of 0.1 S / cm, the impedance in a high frequency range is large, and the MnO ₂ electrolyte, which requires a high process temperature, is repeatedly applied many times. Therefore, there is a disadvantage that a leakage current defect is liable to occur essentially.
Each time O ₂ is formed, it is necessary to carry out a re-chemical treatment for repairing the oxide film as a dielectric, so that the electrolyte forming process is complicated. Further, MnO ₂ has a drawback that it easily ignites at the time of failure due to its oxidizing action.

[0003] Further, when TCNQ is used as an electrolyte layer,
TCNQ was inferior in heat resistance because it melted at a temperature lower than the solder temperature. Further, since the conductivity of TCNQ is limited to about 1 S / cm, it cannot meet the demand for a capacitor having more excellent high frequency characteristics. for that reason,
A solid electrolytic capacitor has been proposed in which a conductive polymer having higher conductivity than MnO ₂ or TCNQ and having higher heat resistance than TCNQ is used as an electrolyte layer. For example, JP-A-60-
Japanese Patent No. 37114 discloses a capacitor in which a conductive polymer composed of a doped five-membered heterocyclic polymer is used as an electrolyte layer. Japanese Patent Application Laid-Open No. 63-80517 discloses a capacitor in which a thin film layer is formed by applying a volatile solvent solution of a polymer of a five-membered heterocyclic compound and a doped one is used as an electrolyte layer. JP 6
Japanese Patent Application Laid-Open No. 4-24410 discloses a method for manufacturing an electrolytic capacitor in which aniline is introduced in a liquid phase onto an oxide film, and then a solution of a protonic acid and an oxidizing agent is introduced to form a solid electrolyte layer made of polyaniline. .

However, the method of forming an electrolyte comprising a conductive polymer described in Japanese Patent Application Laid-Open No. 60-37114 is an electrolytic polymerization method, so the steps are complicated, and particularly, like a tantalum solid electrolytic capacitor, Forming a small capacitor element is inferior in mass productivity. Also, conducting such electrode reactions on the dielectric surface of a capacitor that is insulative usually involves considerable difficulty. Further, as disclosed in JP-A-63-80517, in the method of applying a volatile solvent solution of an insulated conductive polymer, the solution is filled into the fine irregularities on the surface of the capacitor element. Since the conductive polymer layer cannot be formed with a sufficient thickness without being soaked, the heat resistance of the capacitor is inferior, and since the conductive polymer film is too dense, the change due to stress in the process is large, and the exterior is molded. There was a tendency that the properties after the operation were reduced.

According to the method disclosed in Japanese Patent Application Laid-Open No. 64-24410, it is possible to obtain an electrolyte layer that is resistant to process stress. However, in order to form a conductive polymer layer with a sufficient thickness, a large number of electrolyte layers are required. It has to be repeatedly applied, which has the disadvantage of lengthening the process. Japanese Patent Application Laid-Open No. 7-94368 discloses a method of forming polypyrrole by chemical oxidative polymerization, then adhering polypyrrole powder to form irregularities on the capacitor element surface, and then forming a second polypyrrole layer by chemical oxidative polymerization. Although, in this method, the unevenness is formed to improve the adhesive force with the carbon paste or the silver paste, but since the thickness of the polypyrrole layer cannot be increased,
In order to obtain a polypyrrole layer having a sufficient thickness, it is necessary to repeatedly apply the coating many times, which has a disadvantage that the process becomes long.

[0006]

According to the first and second aspects of the present invention, a conductive film can be formed only by coating and drying, and this film is suitable for applications such as electrolytes.
From low frequency to high frequency, capacitance, internal resistance, dielectric loss,
An object of the present invention is to provide a polyaniline-based paste capable of producing a solid electrolytic capacitor having excellent impedance, resistance to process stress, and excellent heat resistance in a short process. A third aspect of the present invention provides a polyaniline-based paste capable of producing a solid electrolytic capacitor having excellent heat resistance, in addition to the effects of the first or second aspect of the present invention.

According to a fourth aspect of the present invention, in addition to the effects of the first, second or third aspect of the present invention, there is provided a polyaniline-based paste which does not deteriorate in properties when a carbon paste or a silver paste is formed. . The invention according to claim 5 provides, in addition to the effects of the invention according to claim 1, 2, 3 or 4, a solid electrolytic solution having no characteristic deterioration before and after a process in which a stress is applied to the polyaniline electrolyte layer such as resin molding or solder reflow. An object of the present invention is to provide a polyaniline-based paste from which a capacitor can be manufactured.

The invention described in claim 6 provides a method of manufacturing a solid electrolytic capacitor having high heat resistance and capable of manufacturing a solid electrolytic capacitor having excellent capacity, internal resistance, dielectric loss, and impedance from low to high frequencies. Things. The invention according to claim 7 provides a method for manufacturing a solid electrolytic capacitor which has high heat resistance and can easily produce a solid electrolytic capacitor excellent in capacity, internal resistance, dielectric loss, and impedance from low to high frequencies in a short process. To provide. The invention according to claim 8 provides a method for manufacturing a solid electrolytic capacitor which can easily produce a solid electrolytic capacitor having high heat resistance and excellent in capacity, internal resistance, dielectric loss, and impedance from low to high frequencies with good workability. To provide. The ninth aspect of the present invention is to provide a solid electrolytic capacitor having high heat resistance and having excellent capacity, internal resistance, dielectric loss, and impedance from low to high frequencies.

[0009]

The present invention relates to a polyaniline paste comprising conductive polyaniline particles, a polyamide polymer and a solvent. Also, the present invention
The present invention relates to the polyaniline-based paste, wherein the conductivity of the coating film obtained by coating and drying exceeds 0.1 S / cm. Further, the present invention relates to the polyaniline-based paste, wherein the dopant of the conductive polyaniline-based particles is at least one selected from the group consisting of phenolsulfonic acid, phenoldisulfonic acid, nitrobenzenesulfonic acid, sulfobenzoic acid, and sulfosuccinic acid.

[0010] The present invention also relates to the polyaniline-based paste, wherein the polyamide-based polymer has a glass transition temperature of 130 ° C or higher. Further, in the present invention, the diamine component constituting the polyamide-based polymer is represented by the general formula (I):

Embedded image (Wherein, Y ¹ is a divalent hydrocarbon group, Y ² is a monovalent hydrocarbon group, two Y ^{1 s} may be the same or different, and a plurality of Y ² are the same And m may be an integer of 1 or more).

The present invention also relates to a method for manufacturing a solid electrolytic capacitor, wherein at least a part of an electrolyte is formed using the polyaniline-based paste. Also, the present invention provides a step of alternately impregnating an element having an oxide film formed on a valve metal with an aqueous solution of ammonium peroxodisulfate and a solution containing an aniline compound and an organic sulfonic acid, and impregnating the polyaniline paste after the step. And a step of drying the solid electrolytic capacitor. Further, the present invention is a step of impregnating the element having an oxide film formed on the valve metal with a solution containing an aqueous solution of ammonium peroxodisulfate and an aniline compound and an organic sulfonic acid, and after the step, impregnated with the polyaniline-based paste, The present invention relates to a method for manufacturing a solid electrolytic capacitor, which comprises a step of drying.
Further, the present invention relates to a solid electrolytic capacitor manufactured by the method for manufacturing a solid electrolytic capacitor.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The conductive polyaniline-based particles in the present invention are particles of a conductive polyaniline compound. The conductive polyaniline compound is obtained by doping an acid or the like into a polyaniline compound (having no conductivity) to exhibit conductivity. As the polyaniline compound in the present invention, a known one can be used without any particular limitation. However, from the viewpoint that the polyaniline compound is obtained in the form of particles, a compound obtained by chemically oxidizing and polymerizing the aniline compound in an acidic solution is preferable.

The aniline compound in the present invention includes:
General formula (II)

Embedded image (Wherein, a plurality of Rs each independently represent an alkyl group, an alkenyl group, an alkoxy group, a cycloalkyl group, a cycloalkenyl group or an alkanoyl group, and n is an integer of 0 to 5) Where n is 0
The aniline having no substituent is preferable in that the obtained electrolyte has high conductivity and is inexpensive.

The oxidizing agent used in the chemical oxidative polymerization method includes:
Any polymerizable aniline compound such as ammonium peroxodisulfate, iron (III) chloride, ammonium dichromate, sodium dichromate, and hydrogen peroxide can be used, but ammonium peroxodisulfate is preferred from the viewpoint of conductivity. .

The conductive polyaniline-based particles in the present invention are obtained, for example, by purifying the particulate polyaniline compound obtained by the above-mentioned chemical oxidation polymerization method by washing it with water and / or an organic solvent, if necessary. And then undoped once with alkali and then doped with an acid or the like. The shape of the conductive polyaniline-based particles is not particularly limited, and examples thereof include a spherical shape, a football shape, a prism shape, a disc shape, an oval shape, and a square plate shape. In terms of the conductivity of the formed electrolyte, the particle shape is a football shape or a prismatic shape, or a disk shape, an oval shape,
In some cases, a flat shape such as a square plate shape is preferable. In such a case, the aspect ratio of the conductive polyaniline-based particles (the distance (in the particle) between points a and b defined by an arbitrary straight line penetrating the surface of the particle at two points a and b)
Longest distance Lab _(max) shortest distance Lab
_((min) = ₍ Lab _(max) / Lab _(min) )) is preferably from 3 to 30, more preferably from 5 to 20.

A football shape, a prism shape or a disc shape,
The conductive polyaniline-based particles having a flat shape such as an oval shape and a square plate shape are, for example, bead milling in which the conductive polyaniline-based particles of the present invention are dispersed in a solvent, and beads for grinding are mixed and stirred. It can be obtained as a mixture with a solvent by a method or the like. From this, only the conductive polyaniline-based particles can be obtained by drying the mixture with the solvent, but the mixture with the solvent obtained by bead milling is directly used in the present invention. Can be used as a polyaniline-based paste. The concentration of the polyaniline compound powder in this mixture can be further adjusted by concentration or dilution.

Tg of the polyamide polymer in the present invention
(Glass transition temperature) is preferably 130 ° C. or higher, more preferably 150 ° C. or higher, and most preferably 16 ° C. or higher.
0 ° C. or higher. If the Tg is 130 ° C. or lower, the characteristics of the capacitor tend to be degraded due to stress caused by heat during the carbon paste baking step, the silver paste baking step, and molding.

The polyamide polymer in the present invention is not particularly limited, but may be a polyamide-silicon polymer obtained by polycondensing an aromatic dicarboxylic acid or a reactive derivative thereof with a diamine containing diaminosiloxane as an essential component. A polyamideimide silicon polymer obtained by polycondensing an aromatic tricarboxylic acid or a reactive acid derivative thereof with a diamine containing diaminosiloxane as an essential component is preferably used.

Examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, 4,4'-diphenyl ether dicarboxylic acid, 4,4'-diphenyl dicarboxylic acid, 4,4'-diphenyl sulfone dicarboxylic acid,
5'-naphthalenedicarboxylic acid and the like. Of these, terephthalic acid and isophthalic acid are preferred in that they are easily available and inexpensive, and that the resulting polymer has solubility.
The reactive derivative of the aromatic dicarboxylic acid means a dihalide of the aromatic dicarboxylic acid, for example, dichloride dibromide, diester and the like.

The aromatic tricarboxylic acids include trimellitic acid, 3,3,4'-benzophenone tricarboxylic acid, 2,3,4'-diphenyltricarboxylic acid,
2,3,6-pyridinetricarboxylic acid, 3,4,4'-
Benzanilide tricarboxylic acid, 1,4,5-naphthalene tricarboxylic acid, 2'-methoxy-3,4,4'-diphenyl ether tricarboxylic acid, 2'-chlorobenzanilide-3,4,4'-tricarboxylic acid and the like. be able to.

The reactive derivative of the aromatic tricarboxylic acid means an acid anhydride, halide, ester, amide, ammonium salt, etc. of the aromatic tricarboxylic acid. Examples of these include trimellitic anhydride, trimellitic anhydride monochloride, 1,4-dicarboxy-3-N, N′-dimethylcarbamoylbenzene,
1,4-dicarbomethoxy-3-carbophenoxybenzene, 2,6-dicarboxy-3-carbomethoxypyridine, 1,6-dicarboxy-5-carbamoylnaphthalene, the above aromatic tricarboxylic acids and ammonia, dimethylamine, Examples include ammonium salts composed of triethylamine and the like. Of these, trimellitic anhydride and trimellitic anhydride monochloride are preferred because they are easily available and inexpensive.

The diamine component in the present invention is represented by the following general formula (I):

Embedded image (Wherein, Y ¹ is a divalent hydrocarbon group, Y ² is a monovalent hydrocarbon group, two Y ^{1 s} may be the same or different, and a plurality of Y ² are the same And m may be different, and m is an integer of 1 or more).

In the general formula (I), Y ¹ is preferably an alkylene group having 1 to 5 carbon atoms, a phenylene group or an alkyl-substituted phenylene group, and Y ² is preferably an alkyl group having 1 to 5 carbon atoms. Alternatively, it is an alkoxy group, a phenyl group or an alkyl-substituted phenyl group. In the general formula (I), m is preferably 100 or less. If m is too large, the ratio of the amide bond and the imide bond in the obtained polymer decreases, and the heat resistance tends to decrease. When a compound represented by the general formula (I) having m of 6 or more is used, the resulting polyamide silicone polymer or polyamide-imide silicone polymer exhibits a low elastic modulus,
When the polymer has a molecular weight of 16 or more, the polymer exhibits a low elastic modulus and an improved heat resistance.

The diaminosiloxane represented by the general formula (I) includes, for example,

Embedded image And the like. In the above formula, m is 1 to 10
A number in the range 0.

Among the diaminosiloxanes, in the above general formula (I), those wherein m is 1, those having an average of 10, those having an average of 20, those having an average of 38 and those having an average of 50 are each represented by L
P-7100, X-22-161AS, X-22-16
1A, X-22-161B and X-22-161-C
(All are trade names of Shin-Etsu Chemical Co., Ltd.). One or more of these diaminosiloxanes can be used.

Diaminosiloxane can effectively prevent a decrease in molecular weight, and can be an ether compound such as tetrahydrofuran, dioxane, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, and cyclohexane, 4-methylcyclohexane. The solubility in general-purpose low-boiling organic solvents such as alicyclic ketone compounds is good.
The diaminosiloxane is preferably used in an amount of 0.2 to 15 mol% based on the total amount of the diamine from the viewpoints of adhesion, heat resistance, molecular weight, and elastic modulus.

The other diamine component which can be used in combination with the diaminosiloxane is not particularly limited, but it is preferable to use an aromatic diamine from the viewpoint of heat resistance.
2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [3-methyl-4- (4-
Aminophenoxy) phenyl] propane, 2,2-bis [4- (4? Aminophenoxy) phenyl] butane,
2,2-bis [3-methyl-4- (4-aminophenoxy) phenyl] butane, 2,2-bis [3,5-dimethyl-4- (4-aminophenoxy) phenyl] butane,
2,2-bis [3,5-dibromo-4- (4-aminophenoxy) phenyl] butane, 1,1,1,3,3,3
-Hexafluoro-2,2-bis [3-methyl-4-
(4-aminophenoxy) phenyl] propane, 1,1
-Bis [4- (4-aminophenoxy) phenyl] cyclohexane, 1,1-bis [4- (4-aminophenoxy) phenyl] cyclopentane, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [ 4- (4-
Aminophenoxy) phenyl] ether, bis [4-
(3-aminophenoxy) phenyl] sulfone, 4,
4'-carbonylbis (p-phenyleneoxy) dianiline, 4,4'-bis (4-aminophenoxy) biphenyl, 1,3-bis (3-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) )benzene,
1,4-bis (4-aminophenoxy) benzene, 1,
3-bis (3-aminophenoxy) benzene, 4,4 '
-[1,3-phenylenebis (1-methylethylidene)] bisaniline, 4,4 '-[1,4-phenylenebis (1-methylethylidene)] bisaniline, 3,
3 '-[1,3-phenylenebis (1-methylethylidene)] bisaniline, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 4,
4'-diamino-3,3 ', 5,5'-tetramethyldiphenylmethane, 4,4'-diamino-3,3', 5
5'-tetraethyldiphenyl ether, 2,2-
[4,4'-diamino-3,3 ', 5,5'-tetramethyldiphenyl] propane, metaphenylenediamine,
Examples thereof include paraphenylenediamine and 3,3'-diaminodiphenylsulfone. When these compounds are used, the characteristics of heat resistance and low elastic modulus can be simultaneously improved. Of these, 2,2-bis [4- (4-aminophenoxy) phenyl] propane is particularly preferred.

Examples of the diamine other than the aromatic diamine include piperazine, hexamethylenediamine, heptamethylenediamine, tetramethylenediamine, p-xylylenediamine, m-xylylenediamine, and 3-methylheptamethylenediamine. May be used in combination. These aromatic diamines are preferably used in combination for improving heat resistance, and are preferably used in an amount of 0.1 to 99.9 mol%, more preferably 0.2 to 9 mol%, based on the total amount of the diamine. 90
Mol%.

In the present invention, the aromatic dicarboxylic acid or its reactive derivative is preferably used in a total amount of 80 to 120 mol% with respect to a total amount of 100 mol% of the diamine.
It is more preferable to use 95 to 105 mol%. When these are used in equimolar amount with respect to the total amount of the diamine, the highest molecular weight is obtained. For diamines,
If the amount of the aromatic dicarboxylic acid or its reactive derivative is too large or too small, the molecular weight tends to decrease, and the mechanical strength and heat resistance tend to decrease.

The polyamide polymer obtained by the polycondensation reaction of the above aromatic dicarboxylic acid or its reactive derivative with a diamine has a reduced viscosity of 0.3% at 30 ° C. in a 0.2% by weight solution of dimethylformamide. 2-2.0dl
/ g is preferred. If the reduced viscosity is too small, mechanical strength and heat resistance tend to decrease, and if too large, the solubility in a solvent tends to decrease.

As the solvent in the present invention, for example,
Water, hexane, cyclohexane, heptane, octane,
Toluene, xylene, methanol, ethanol, propanol, isopropanol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, methyl cellosolve, ethyl cellosolve,
Butyl cellosolve, methyl carbitol, ethyl carbitol, butyl carbitol, triethylene glycol monomethyl ether, triethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monopropyl ether, dipropylene glycol monomethyl ether, ethylene glycol dimethyl ether, ethylene Glycol diethyl ether, diethylene glycol diethyl ether, diethylene glycol ethyl methyl ether, diglyme, triglyme, tetraethylene glycol dimethyl ether, tetrahydrofuran, dimethyl ether, trioxane, dioxane, acetone, methyl ethyl ketone, methyl acetate, ethyl acetate, ethylene carbonate,
Ethylene glycol monoethyl ether acetate, ethylene glycol monomethyl ether acetate, diethylene glycol diacetate, N, N-dimethylformamide, dimethyl sulfoxide, nitrobenzene, N
-Methyl-2-pyrrolidone, 2-cyclohexanone, 4
-Methyl-2-cyclohexanone, acetonitrile, picoline, sulfolane and the like. These can be used in combination of a plurality of types.

Further, it is preferable to include an acid in the solvent because the dopant is less likely to be eliminated from the conductive polyaniline-based particles and the binding property of the conductive polyaniline-based particles is improved. As the acid in this case, those preferably used as a dopant for the conductive polyaniline-based particles in the present invention (described later) are preferable. The amount of the acid contained in the solvent is preferably 1 to 25% by weight, more preferably 2 to 20% by weight, and particularly preferably 3 to 10% by weight.

The polyaniline-based paste of the present invention can be prepared by mixing and stirring the conductive polyaniline-based particles and a solvent, and using the solvent used for obtaining the conductive polyaniline-based particles having a specific shape as described above. It may be prepared as it is.

The polyaniline-based paste of the present invention is preferably applied to a substrate such as a glass plate and dried to have a conductivity of more than 0.1 S / cm.
More preferably, it exceeds 0.3 S / cm. When the conductivity is less than 0.1 S / cm, the internal resistance of the solid electrolytic capacitor tends to increase. The conductivity achievable by the present invention is on the order of 1000 S / cm.

As the acid used as a dopant for the conductive polyaniline-based particles in the present invention, known acids can be used without any particular limitation. However, from the viewpoint of heat resistance and conductivity of the obtained conductive polyaniline-based particles, organic sulfones are used. Acids are preferred. As organic sulfonic acids, from the viewpoint of heat resistance and conductivity, benzenesulfonic acid, toluenesulfonic acid,
n-hexanesulfonic acid, n-octylsulfonic acid, dodecylsulfonic acid, cetylsulfonic acid, 4-dodecylbenzenesulfonic acid, camphorsulfonic acid, poly (vinyl) sulfonic acid, dinonylnaphthalenesulfonic acid, naphthalenesulfonic acid, p- Chlorobenzenesulfonic acid, phenolsulfonic acid, phenoldisulfonic acid, trichlorobenzenesulfonic acid, 4-nitrotoluene-2-sulfonic acid, 1-octanesulfonic acid, sulfonated polystyrene, sulfonated polyethylene, sulfobenzoic acid,
-Nitrobenzenesulfonic acid, 4-octylbenzenesulfonic acid, 2-methyl-5-isopropylbenzenesulfonic acid, and sulfosuccinic acid are preferred. Of these, phenolsulfonic acid, phenoldisulfonic acid, sulfobenzoic acid, sulfosuccinic acid, and nitrobenzenesulfonic acid Is more preferred. It is also a preferred method to use sulfuric acid in combination with these organic sulfonic acids.

The proportion of each component in the polyaniline paste of the present invention is preferably 1 to 100 parts by weight of the polyamide polymer and 100 to 4000 parts by weight of the solvent with respect to 100 parts by weight of the conductive polyaniline particles. preferable. When the amount of the polyamide polymer is less than 10 parts by weight, the effect of improving the adhesion and film-forming properties tends to be low, and when it exceeds 100 parts by weight, the conductivity tends to decrease. If the solvent is less than 100 parts by weight, the viscosity tends to be high, and the conductivity tends to be poor.
If the amount exceeds 0 parts by weight, the number of times of immersion and drying is increased to obtain a predetermined film thickness, and the workability tends to be poor.

The thickness of the film formed by the polyaniline paste of the present invention is preferably 2 to 50 μm, more preferably 4 to 30 μm, and more preferably 6 to 20 μm.
It is particularly preferable to set it to μm. If the film thickness is less than 2 μm, the leakage current of the capacitor tends to increase,
If it exceeds 0 μm, the internal resistance of the capacitor tends to increase.

The valve metal used for the fixed electrolytic capacitor of the present invention is aluminum, tantalum, niobium, vanadium,
Titanium, zirconium and the like can be mentioned, but an expanded aluminum foil or a tantalum sintered body is preferable from the viewpoint of the dielectric constant and the ease of forming an oxide film. The method of forming an oxide film on the valve metal surface in the present invention can be used without any particular limitation as long as it is a method usually used in the production of electrolytic capacitors. For example, an aluminum foil expanded by etching is treated with an aqueous solution of ammonium adipate Known methods such as forming an oxide film by applying a voltage in the inside and forming an oxide film by applying a voltage to a tantalum fine powder sintered body pellet in an aqueous nitric acid solution are used.

The solid electrolytic capacitor of the present invention is manufactured by forming at least a part of an electrolyte using a polyaniline-based paste. Manufacturing of the solid electrolytic capacitor of the present invention will be described with reference to FIG. FIG. 1 is a cross-sectional view showing an example of a solid electrolytic capacitor of the present invention in which tantalum is used as a valve metal, and an oxide film 3 is formed on the surface of a tantalum pellet 2 provided with lead terminals 1 by sintering fine tantalum powder. And an electrolyte 4 comprising a polyaniline compound formed thereon.
Is formed, then a carbon paste layer 5 and a silver paste layer 6 are sequentially formed, and a cathode lead 7 is connected to the silver paste layer 6 by using a conductive paste.
Is connected to the anode lead 9 and then molded and covered with a sealing material 8 such as an epoxy resin to obtain a solid electrolytic capacitor of the present invention using tantalum as a valve metal.

The electrolyte in the present invention is used for forming a thin oxide film as a dielectric on the surface of a metal (valve metal) used as an anode of an electrolytic capacitor, and then obtaining an electrical contact between the dielectric film and the cathode. Refers to a conductive substance. The electrolyte is formed by, for example, (1) a method of forming an electrolyte by chemical oxidation polymerization of an aniline compound, and (2) coating or impregnating a solution in which a polyaniline compound is dissolved in a solvent capable of dissolving the same, and drying as necessary. (3) A method of forming an electrolyte by applying or impregnating the polyaniline-based paste for forming an electrolyte of the present invention and drying it as necessary, etc. It can be carried out in appropriate combinations. Of course, the method (3) alone can be used, but the film-forming property is slightly poor.

When the methods (1) and (3) are combined, for example, an element having an oxide film formed on a valve metal is alternately mixed with an aqueous solution of ammonium peroxodisulfate and a solution containing an aniline compound and an organic sulfonic acid. After the step of impregnating the polyaniline-based paste of the present invention and the step of impregnating with the polyaniline-based paste of the present invention and then drying, an electrolyte is formed and a solid electrolytic capacitor can be manufactured. Further, for example, after the step of impregnating an element having an oxide film formed on a valve metal with an aqueous solution of ammonium peroxodisulfate, a solution containing an aniline compound and an organic sulfonic acid (one-part method), and after the step, the polyaniline-based compound of the present invention is obtained. By performing at least the step of impregnating and drying the paste, an electrolyte is formed and a solid electrolytic capacitor can be manufactured.

The aqueous solution of ammonium peroxodisulfate used in the two-liquid method can be obtained by dissolving ammonium peroxodisulfate in ion-exchanged water. When this aqueous solution is stored at room temperature or higher, ammonium peroxodisulfate tends to decompose and the oxidizing power tends to decrease. Therefore, it is preferable to use one prepared immediately before use or stored in a refrigerator. The amount of ammonium peroxodisulfate in the aqueous ammonium peroxodisulfate solution depends on the amount of the aniline compound in the solution containing the aniline compound and the organic sulfonic acid used, and the amount of aniline in the solution containing the aniline compound and the organic sulfonic acid. The molar concentration ratio is preferably 0.4 to 1.4 times, more preferably 0.6 to 1.2 times, relative to the compounding amount of the compound,
It is particularly preferable that the ratio be 0.7 to 1.0 times. If it is less than 0.4 times or more than 1.4 times, the conductivity of the obtained electrolyte tends to decrease, and the internal resistance of the capacitor tends to increase.

As the organic sulfonic acid in the solution containing the aniline compound and the organic sulfonic acid used in the above two-part method, any known organic sulfonic acid can be used without any particular limitation. In terms of conductivity, the same ones as those exemplified as the organic sulfonic acid as the dopant for the polyaniline-based particles in the description of the polyaniline-based paste are preferable. The solution containing the aniline compound and the organic sulfonic acid is obtained by dissolving the aniline compound and the organic sulfonic acid in a solvent. The solvent is preferred in view of the conductivity of the electrolyte from which water or a mixed solvent of water and an organic solvent is obtained. When using a mixed solvent of water and an organic solvent containing 10 to 75% by volume, preferably 25 to 60% by volume of a solvent having a boiling point lower than that of water, for example, methanol, ethanol, propanol, acetone, acetonitrile, etc. This is desirable because the solubility of the aniline compound is improved and the formability of the electrolyte is also improved.

The amount of the aniline compound in the solution containing the aniline compound and the organic sulfonic acid is 1 to 12%.
%, More preferably 1.5 to 10% by weight, and particularly preferably 2 to 9% by weight. If the amount is less than 1% by weight, it is necessary to repeat the impregnation of the solution many times, which tends to lengthen the process and deteriorate the binding property of the outer layer portion of the electrolyte. On the other hand, if it exceeds 12% by weight, the conductivity of the obtained electrolyte tends to decrease, and the internal resistance of the capacitor tends to increase.

The compounding amount of the organic sulfonic acid in the solution containing the aniline compound and the organic sulfonic acid depends on the aniline compound, and is 0.2 to 1.5 times the molar amount of the aniline compound. Preferably, 0.2
It is more preferably 5 to 1.2 times, and 0.3 to 1.
It is particularly preferable to make it 0 times. Less than 0.2 times or 1.
If it exceeds 5 times, the conductivity of the obtained electrolyte tends to decrease, and the internal resistance of the capacitor tends to increase.

In the step of alternately impregnating the aqueous solution of ammonium peroxodisulfate and the solution containing the aniline compound and the organic sulfonic acid in the above two-liquid method, impregnating with the aqueous solution of ammonium peroxodisulfate, drying if necessary, and then drying the aniline compound and A solution containing an organic sulfonic acid is impregnated, and the aniline compound is chemically polymerized on the oxide film, and then dried if necessary. The order may be reversed, and the solution containing the aniline compound and the organic sulfonic acid may be impregnated first.

In the step of impregnating a solution containing ammonium peroxodisulfate, an aniline compound and an organic sulfonic acid in the one-liquid method, for example, an aqueous solution of ammonium peroxodisulfate (the same one as described in the two-liquid method can be used) And a solution containing an aniline compound and an organic sulfonic acid (the same ones as described in the two-part method can be used), and then impregnated in the element at an unreacted stage. After chemical polymerization,
It can be dried as appropriate. Here, after mixing the aqueous solution of ammonium peroxodisulfate with the solution containing the aniline compound and the organic sulfonic acid, in the step of impregnating, the solution temperature is cooled to -5 to -20 ° C before mixing the solution. After mixing, it is preferable because the polyaniline compound can be prevented from being precipitated in the solution before impregnation. Immediately after the solution is mixed, the device is impregnated, and after the aniline compound is chemically polymerized on the oxide film, it can be dried as appropriate.

In a preferred embodiment for forming the electrolyte of the solid electrolytic capacitor of the present invention, an element having an oxide film formed on a valve metal is alternately impregnated with an aqueous solution of ammonium peroxodisulfate and a solution containing an aniline compound and an organic sulfonic acid. After drying, if necessary, or after mixing an aqueous solution of ammonium peroxodisulfate with a solution containing an aniline compound and an organic sulfonic acid, the mixture is impregnated with and dried if necessary.
Repeat the procedure about once to form the inner layer of the electrolyte that is in direct contact with the oxide film, then impregnate the solid electrolyte capacitor with a polyaniline-based paste for forming the electrolyte, and dry to form the outer layer of the electrolyte. The aqueous solution of ammonium disulfate and the solution containing the aniline compound and the organic sulfonic acid are alternately impregnated and dried as necessary, or the aqueous solution of ammonium peroxodisulfate and the solution containing the aniline compound and the organic sulfonic acid are mixed. In this embodiment, the outermost layer of the electrolyte is formed by performing the operation of impregnating with the liquid and drying as necessary about 1 to 5 times.

In a device made of a porous sintered body such as a tantalum electrolytic capacitor, the electrolyte inside the pores of the porous sintered body (that is, the electrolyte in the inner layer) is formed by the one-liquid method or the two-liquid method. (The polyaniline-based paste for forming an electrolyte of the solid electrolytic capacitor of the present invention has a tendency that conductive polyaniline-based particles are less likely to enter the inside of the pores, and the ability to follow a complicated surface tends to be insufficient.
It is not necessarily suitable for forming the inner layer of the electrolyte).
It is preferable to use the polyaniline-based paste for forming the electrolyte of the solid electrolytic capacitor of the present invention when forming the electrolyte in the inner layer by the one-liquid method and the two-liquid method and forming the electrolyte thereon (outer layer).

The polyaniline paste for forming an electrolyte of a solid electrolytic capacitor according to the present invention can form an electrolyte having a sufficient thickness with a relatively small number of impregnation operations, thereby contributing to shortening of the process. Further, since the electrolyte obtained from the polyaniline-based paste for forming the electrolyte of the solid electrolytic capacitor can be a high-purity polyaniline compound, the internal resistance of the capacitor can be reduced. When the outer layer of the electrolyte is formed with the polyaniline paste for forming the electrolyte of the solid electrolytic capacitor and then the outer layer of the electrolyte is formed by the one-liquid method and the two-liquid method, the binding property is further improved and the conductive polyaniline is improved. Resistance between system particles can be reduced.

[0051]

The present invention will be described below with reference to examples. Synthesis Example 1 120 ml of aniline (reagent, manufactured by Wako Pure Chemical Industries, Ltd.) and 1
50 ml of 35% by weight hydrochloric acid (reagent, manufactured by Wako Pure Chemical Industries, Ltd.)
And 120 ml of distilled water were placed in a 3 liter Erlenmeyer flask and cooled to 0 ° C. While maintaining the temperature at 0 ° C., while stirring the solution in the Erlenmeyer flask, 138 g of ammonium peroxodisulfate (reagent, manufactured by Wako Pure Chemical Industries, Ltd.) dissolved in 300 ml of distilled water was added over 2 hours to add aniline. Polymerization was performed. After the addition of ammonium peroxodisulfate, the mixture was kept at 0 ° C. for 3 hours with stirring. Since polyaniline is in a powder form, it is filtered, washed sufficiently with distilled water, and then washed with methanol and ether. The thoroughly washed powdered polyaniline was then dried in a vacuum dryer at 50 ° C. under reduced pressure. Next, 100 g of the dried powdered polyaniline was placed in 10 liters of 3% by weight ammonia water and stirred for 2 hours. The obtained basic polyaniline powder was filtered, and then sufficiently washed with distilled water and methanol. After washing with ether, the resultant was dried at 50 ° C. under reduced pressure in a vacuum dryer (yield: 36% by weight).

Synthesis Example 2 10 g of the basic polyaniline obtained in Synthesis Example 1 was added to p-phenolsulfonic acid (manufactured by Nippon Chemical Industry Co., Ltd.).
The dispersion was dispersed in 100 g of a 0% by weight aqueous solution, and the temperature was maintained at 65 ° C. for 8 hours with stirring. After filtering the thus obtained conductive polyaniline-based particles, they are sufficiently washed with acetone to remove excess p-phenolsulfonic acid, and then dried at 50 ° C. under reduced pressure in a vacuum drier to obtain conductive polyaniline-based particles. 1 was obtained.

Synthesis Example 3 10 g of the basic polyaniline obtained in Synthesis Example 1 was added to 100 g of a 50% by weight aqueous solution of sulfosuccinic acid (manufactured by Aldrich).
And maintained at 65 ° C. for 8 hours with stirring.
After filtering the conductive polyaniline-based particles thus obtained,
Excessive sulfosuccinic acid was removed by washing sufficiently with acetone, and then dried at 50 ° C. under reduced pressure in a vacuum dryer to obtain conductive polyaniline-based particles 2.

Synthesis Example 4 In a four-necked flask equipped with a stirrer, a nitrogen inlet tube, a thermometer and a reflux tube, 2,2-bis [4- (4-
Aminophenoxy) phenyl] propane (Wako Pure Chemical Industries)
65.6 g (0.16 mol) of the following formula (III)

Embedded image Of diaminosiloxane (0.04 mol) (80 mol% / 20 mol% in molar ratio) was dissolved in 335 g of diethylene glycol dimethyl ether.

The solution was maintained at -10 ° C, and 40.6 g (0.2 mol) of isophthalic chloride (manufactured by Aldrich) was added while controlling the temperature at -10 to -5 ° C. afterwards,
23.2 g of propylene oxide was added, 96 g of diethylene glycol dimethyl ether was added, and stirring was continued at room temperature for 3 hours. The reaction solution was poured into a large amount of methanol (reagent, manufactured by Wako Pure Chemical Industries, Ltd.), the polymer was isolated, dried, and then dissolved again in N, N-dimethylformamide. The silicon polymer was purified. The Tg of this polymer was 180 ° C.

Synthesis Example 5 In a four-necked flask equipped with a stirrer, a nitrogen inlet tube, a thermometer and a reflux tube, 2,2-bis [4- (4-
Aminophenoxy) phenyl] propane (Wako Pure Chemical Industries)
174.3 g (0.425 mol) of the following formula (IV)

Embedded image Of diaminosiloxane (0.075 mol) (85 mol% / 15 mol% in molar ratio) was dissolved in 1177 g of diethylene glycol dimethyl ether.

The solution was kept at −10 ° C., and 105.3 g of trimellitic acid monochloride (reagent, manufactured by Aldrich) was used.
(0.5 mol) was added while controlling to -10 to -5 ° C. Thereafter, 87 g of propylene oxide was added, and stirring was continued at room temperature for 3 hours. When the viscosity of the reaction solution increased and the solution became transparent, 841 g of diethylene glycol dimethyl ether was added, and stirring was continued at room temperature for 1 hour.
128 g of acetic anhydride and 64 g of pyridine were added, and stirring was continued at 60 ° C. for 24 hours. A large amount of hexane / methanol = 1/1 (weight ratio, each product manufactured by Wako Pure Chemical Industries, Ltd.)
After the polymer was isolated and dried, the polymer was dissolved in N, N dimethylformamide and poured into methanol to purify the polyamide-imide silicon polymer. The Tg of this polymer was 170 ° C.

Synthesis Example 6 10 g of the basic polyaniline obtained in Synthesis Example 1 was added to a 20% by weight aqueous solution of hydrochloric acid (reagent, manufactured by Wako Pure Chemical Industries, Ltd.).
0 g and kept at 40 ° C. for 8 hours with stirring. After filtering the conductive polyaniline-based particles thus obtained, thoroughly washing with acetone to remove excess hydrochloric acid,
Next, the resultant was dried at 50 ° C. under reduced pressure in a vacuum dryer to obtain conductive polyaniline-based particles 3.

Example 1 10 g of the conductive polyaniline-based particles 1 obtained in Synthesis Example 2
40 g of ethanol (reagent, manufactured by Wako Pure Chemical Industries, Ltd.), 54 g of ion-exchanged water, and 6 g of a 65% by weight aqueous solution of p-phenolsulfonic acid (manufactured by Nippon Chemical Industry Co., Ltd.) were dispersed and mixed with a homomixer for 1 hour and then synthesized A polyamide silicon polymer solution in which 7 g of N-methylpyrrolidone was added and dissolved in 3 g of the polyamide silicon polymer obtained in Example 4 was added, and the mixture was again dispersed and mixed with a homomixer for 1 hour to obtain a polyaniline paste 1. This polyaniline-based paste 1 was applied to a glass plate and dried at 120 ° C. for 1 hour. The conductivity of the film obtained was 5 S / cm.

Further, 10 g of ammonium peroxodisulfate (reagent, manufactured by Wako Pure Chemical Industries, Ltd.) was added to 90 g of ion-exchanged water.
To give an aqueous solution of ammonium peroxodisulfate 1. Next, 4 g of degassed aniline (reagent, manufactured by Wako Pure Chemical Industries, Ltd.) obtained by bubbling with nitrogen for 30 minutes, 46 g of degassed ion-exchanged water, and degassed ethanol (Wako Pure Chemical Industries, Ltd.) , Degassed reagent) and 4 g of phenolsulfonic acid (reagent, manufactured by Wako Pure Chemical Industries, Ltd.) to obtain a solution 1 containing aniline and organic sulfonic acid.

A 3.2 mm long, 1.6 mm deep, 3.8 mm high prismatic tantalum fine powder sintered pellet (having a designed capacity of 150 μm) having an oxide film formed at 26 V in an aqueous nitric acid solution.
F) was impregnated with an aqueous solution of ammonium peroxodisulfate 1, dried with a hot air drier at 50 ° C. for 20 minutes, and impregnated with a solution 1 containing aniline and an organic sulfonic acid.
After standing for minutes, it was dried with a hot air drier at 80 ° C. for 20 minutes.
These two liquid impregnation and drying steps were alternately repeated 15 times each to form an inner layer portion of an electrolyte made of polyaniline.

The polyaniline-based paste 1 was impregnated and dried at 120 ° C. for 1 hour to form an outer layer of an electrolyte made of polyaniline. Next, impregnated with an aqueous solution of ammonium peroxodisulfate 1, dried at 50 ° C. for 20 minutes with a hot air drier, impregnated with a solution 1 containing aniline and an organic sulfonic acid, allowed to stand at room temperature for 10 minutes, and then dried with a hot air drier. 80 ℃
For 20 minutes. The two liquid impregnation and drying steps were alternately repeated twice each to form an outermost layer of an electrolyte made of conductive polyaniline. Further, a carbon paste layer and a silver paste layer are sequentially formed, a cathode lead is connected to the silver paste layer using a silver paste, the package is molded with a sealing material, and tantalum is used as a valve metal. An electrolytic capacitor was obtained. Table 1 shows the electrical characteristics of the obtained solid electrolytic capacitor and the number of times of impregnation required to form the electrolyte.

Example 2 5 g of the conductive polyaniline-based particles 2 obtained in Synthesis Example 3, 55 g of diglyme (reagent, manufactured by Wako Pure Chemical Industries, Ltd.), and 1 g of the polyamide silicon polymer obtained in Synthesis Example 4 were homomixed. For 1 hour to obtain a polyaniline-based paste 2. The polyaniline-based paste 2 was applied to a glass plate and dried at 120 ° C. for 1 hour. The conductivity of the film obtained was 7 S / cm.

Further, 4.5 g of ammonium peroxodisulfate (reagent, manufactured by Wako Pure Chemical Industries, Ltd.) was added to 1 part of deionized water.
It was dissolved in 0.5 g to obtain an aqueous solution of ammonium peroxodisulfate 2. Next, degassed aniline (reagent, manufactured by Wako Pure Chemical Industries, Ltd.) obtained by bubbling with nitrogen for 30 minutes 1.8.
g, 15.5 g of degassed ion-exchanged water, 22 g of degassed ethanol (manufactured by Wako Pure Chemical Industries, Ltd., degassing the reagent), and 4.5 g of 70% by weight sulfosuccinic acid (manufactured by Aldrich) were mixed. 2 containing aniline and organic sulfonic acid
I got

The aqueous solution 2 containing ammonium peroxodisulfate 2 and the solution 2 containing aniline and organic sulfonic acid were
After cooling to ℃, the mixture was mixed and shaken well. This mixed solution was immediately impregnated into the same sintered tantalum powder pellet (design capacity: 150 μF) as in Example 1, left in a dryer at 40 ° C. for 10 minutes, and then dried at 120 ° C. for 20 minutes with a hot air dryer. did. This impregnation step was repeated 25 times to form an inner layer portion of an electrolyte made of polyaniline. Hereinafter, a solid electrolytic capacitor was obtained in the same manner as in Example 1 except that the polyaniline-based paste 2 was used. Table 1 shows the electrical characteristics of the obtained solid electrolytic capacitor and the number of times of impregnation required to form the electrolyte.

Comparative Example 1 A solid electrolytic capacitor using tantalum as a valve metal was produced in the same manner as in Example 1 except that the polyaniline paste 1 of the present invention was not used. In order to form an electrolyte layer made of polyaniline with a sufficient thickness, the impregnation step of the aqueous solution 1 containing ammonium peroxodisulfate and the solution 1 containing aniline and organic sulfonic acid had to be repeated 30 times. Table 1 shows the electrical characteristics of the obtained solid electrolytic capacitor and the number of times of impregnation required to form the electrolyte.

Example 3 5 g of the conductive polyaniline-based particles 1 obtained in Synthesis Example 2 and 55 ml of diglyme (reagent, manufactured by Wako Pure Chemical Industries, Ltd.)
Of zirconia beads was placed in a separable flask in a bulk volume of 150 ml each, stirred for 3 hours and taken out. The zirconia beads were removed through a 60-mesh sieve to obtain a mixture of conductive polyaniline-based particles and a solvent. A part of the mixture was vacuum-dried at 100 ° C. for 1 hour, and the shape of the conductive polyaniline-based particles was observed with an SEM to confirm that the average ratio of the five particles was an oval flat shape having an aspect ratio of 15. did. To 5 g of this mixture, 0.1 g of the polyamideimide silicon polymer obtained in Synthesis Example 5 was added and mixed to obtain a polyaniline-based paste 3. This polyaniline-based paste 3 is applied to a glass plate,
The conductivity of the film obtained after drying for a time was 0.4 S / cm.

A solid electrolytic capacitor was obtained in the same manner as in Example 1 except that the polyaniline-based paste 3 was used in place of the polyaniline-based paste 1. Table 1 shows the electrical characteristics of the obtained solid electrolytic capacitor and the number of times of impregnation required to form the electrolyte.

Comparative Example 2 A copolymer resin (Tg 60 ° C.) of ethyl acrylate / butyl acrylate = 80/20 (molar ratio) instead of the polyamide polymer of the polyaniline paste of Example 1
A solid electrolytic capacitor was obtained in the same manner as in Example 1 except for using. Table 1 shows the electrical characteristics of the obtained solid electrolytic capacitor and the number of times of impregnation required to form the electrolyte.

Comparative Example 3 A solid electrolytic capacitor was obtained in the same manner as in Example 1 except that the polyamideimide silicon polymer as the binder resin of the polyaniline-based paste of Example 3 was not used (no binder resin was added). Not evaluated because the capacitor was short-circuited.

Comparative Example 4 10 g of the conductive polyaniline-based particles 3 obtained in Synthesis Example 6
After 100 g of diglyme (reagent, manufactured by Wako Pure Chemical Industries, Ltd.) was dispersed and mixed for 1 hour with a homomixer, 7 g of N-methylpyrrolidone was added to 3 g of the polyamide silicon polymer obtained in Synthesis Example 4.
Was added and dissolved, and the mixture was again dispersed and mixed for 1 hour with a homomixer to obtain a polyaniline paste 4. The polyaniline-based paste 4 was applied to a glass plate and dried at 120 ° C. for 1 hour, and the conductivity of the film obtained was 3 S / cm.

Thereafter, a solid electrolytic capacitor according to Comparative Example 4 was obtained in the same manner as in Example. Table 1 shows the electrical characteristics of the obtained solid electrolytic capacitor and the number of times of impregnation required to form the electrolyte.

[0073]

[Table 1]

As is clear from Table 1, the solid electrolytic capacitors according to Examples 1 to 3 are excellent in both low-frequency characteristics and high-frequency characteristics, and the electrolyte layer is formed with a smaller number of impregnation times than the solid electrolytic capacitor according to Comparative Example 1. Can. The internal resistance at 100 kHz is superior to the solid electrolytic capacitor according to Comparative Example 2, and is less likely to cause a short circuit failure than the solid electrolytic capacitor of Comparative Example 3. The internal resistance at 100 kHz is lower than the solid electrolytic capacitor of Comparative Example 4. Are better.

[0075]

According to the first and second aspects of the present invention, the polyaniline-based paste can form a conductive film only by coating and drying. This film is suitable for applications such as electrolytes, and has a low frequency to a high frequency. Excellent capacity, internal resistance, dielectric loss, impedance up to frequency, strong in process stress,
A solid electrolytic capacitor having excellent heat resistance can be manufactured in a short process. The polyaniline-based paste according to claim 3 can produce a solid electrolytic capacitor having excellent heat resistance in addition to the effects of the invention according to claim 1 or 2.

The polyaniline-based paste according to the fourth aspect has the effect of the invention according to the first, second or third aspect, and furthermore, there is no deterioration in characteristics when a carbon paste or a silver paste is formed, and the polyaniline-based paste can be used in a process such as molding. A solid electrolytic capacitor having excellent heat resistance without deterioration in characteristics against stress can be manufactured in a short process. The invention described in claim 5 provides the effect of the invention described in claim 1, 2, 3, or 4,
Furthermore, a solid electrolytic capacitor having no characteristic deterioration before and after a process of applying stress to a polyaniline electrolyte layer such as a resin mold or solder reflow can be manufactured in a short process.

The method for manufacturing a solid electrolytic capacitor according to the sixth aspect is capable of manufacturing a solid electrolytic capacitor having high heat resistance and excellent capacity, internal resistance, dielectric loss, and impedance from low to high frequencies. The method for manufacturing a solid electrolytic capacitor according to claim 7 is a method for easily manufacturing a solid electrolytic capacitor having high heat resistance and excellent capacity, internal resistance, dielectric loss, and impedance from low to high frequencies in a short process. is there. The method for producing a solid electrolytic capacitor according to claim 8 is capable of easily producing a solid electrolytic capacitor having high heat resistance and excellent in capacity, internal resistance, dielectric loss, and impedance from low to high frequencies with good workability. is there. The solid electrolytic capacitor according to the ninth aspect has high heat resistance, and is excellent in capacity, internal resistance, dielectric loss, and impedance from low to high frequencies.

[Brief description of the drawings]

FIG. 1 is a sectional view of an example of the solid electrolytic capacitor of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lead terminal 2 Tantalum pellet 3 Oxide film 4 Electrolyte 5 Carbon paste layer 6 Silver paste layer 7 Cathode lead 8 Sealing material 9 Anode lead

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01B 1/12 H01B 1/12 G H01G 9/028 H01M 10/40 B H01M 10/40 C09D 5/24 / / C09D 5/24 177/06 177/06 179/00 179/00 H01G 9/02 331H 331G (72) Inventor Akira Sasaki 4-3-1-1, Higashicho, Hitachi City, Ibaraki Prefecture Hitachi Chemical Co., Ltd. In-house (72) Inventor Lanou Patrice 4-3-1, Higashicho, Hitachi, Ibaraki Pref.Hitachi Chemical Industry Co., Ltd. (72) Inventor Toru Yoshikawa 14 Goi-minamikaigan, Ichihara-shi, Chiba Prefecture Hitachi Chemical Co., Ltd. In-house F-term (reference) 4J001 DC10 EB36 EB37 EB46 EB55 EB57 EB60 EB65 EB67 EC07 EC08 EC09 EC29 EC45 EC46 EC47 EC48 EC65 EC66 EC67 EC70 EC75 EC81 EE18A FB03 FC 06 JA07 JB02 JB07 JC06 4J002 CL07W CM05X EV236 FD11X FD116 GQ00 HA08 4J038 DH021 DJ002 DL081 HA156 JA02 JA05 JA19 JA20 JA26 JA27 JA33 JA56 JA70 JA74 JB12 JB18 JB21 JB27 JC01 JC11 JC18 MA20 MA13 MA12 MA13 MA12 MA07 DE01 5H029 AJ00 AK11 AL06 AM16 CJ02 CJ13 CJ23 EJ12 EJ13 HJ02

Claims (9)

[Claims] 1. A polyaniline paste comprising conductive polyaniline particles, a polyamide polymer and a solvent. 2. The polyaniline-based paste according to claim 1, wherein the conductivity of the coating film obtained by coating and drying exceeds 0.1 S / cm. 3. The conductive polyaniline-based particles having a dopant of phenolsulfonic acid, phenoldisulfonic acid,
3. The polyaniline-based paste according to claim 1, wherein the paste is at least one selected from the group consisting of nitrobenzenesulfonic acid, sulfobenzoic acid, and sulfosuccinic acid. 4. The polyaniline paste according to claim 1, wherein the polyamide polymer has a glass transition temperature of 130 ° C. or higher. 5. The diamine component constituting the polyamide polymer is represented by the general formula (I): (Wherein, Y ¹ is a divalent hydrocarbon group, Y ² is a monovalent hydrocarbon group, two Y ^{1 s} may be the same or different, and a plurality of Y ² are the same The polyaniline-based paste according to claim 1, 2 or 3, wherein m is an integer of 1 or more. 6. A method for producing a solid electrolytic capacitor, wherein at least a part of an electrolyte is formed using the polyaniline-based paste according to claim 1. 7. The method according to claim 1, wherein the device having an oxide film formed on the valve metal is alternately impregnated with an aqueous solution of ammonium peroxodisulfate and a solution containing an aniline compound and an organic sulfonic acid. A method for producing a solid electrolytic capacitor, comprising a step of impregnating a polyaniline-based paste and drying. 8. A polyaniline-based compound according to claim 1, wherein said element having an oxide film formed on a valve metal is impregnated with an aqueous solution of ammonium peroxodisulfate and a solution containing an aniline compound and an organic sulfonic acid, and after said step. A method for producing a solid electrolytic capacitor, comprising a step of impregnating and drying a paste. 9. A solid electrolytic capacitor manufactured by the method for manufacturing a solid electrolytic capacitor according to claim 6, 7, or 8.