JP3204551B2 - Method for manufacturing solid electrolytic capacitor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a solid electrolytic capacitor using a conductive organic polymer as a solid electrolyte.

[0002]

2. Description of the Related Art An electrolytic capacitor is a capacitor in which an insulating film is formed on a surface of a metal foil of aluminum or tantalum by electrolytic oxidation treatment, and the insulating film is used as a dielectric.
It has polarity so that the metal foil serves as the anode and the electrolyte side serves as the cathode. Recent main technical requirements for an electrolytic capacitor include miniaturization, low impedance, high reliability, and low cost associated with a high-frequency circuit. In response to these demands, research has been conducted on the direction of solidifying the electrolyte of a liquid electrolytic capacitor. As such a solid electrolyte, for example, various conductive materials such as polypyrrole, polythiophene, polyfuran, and polyaniline are used. Polymers have been proposed.

More specifically, for example, Japanese Patent Application Laid-Open No. 63-17 / 1988
No. 3313, a dielectric oxide film is formed on a film-forming metal, and polypyrrole is deposited thereon by chemical oxidative polymerization of pyrrole, and this is used as a conductive layer. It is described that pyrrole is electrolytically polymerized and a conductive polymer composed of polypyrrole is laminated as a solid electrolyte. Also, Japanese Patent Application Laid-Open No. 1-253
No. 226 also describes that a conductive layer made of manganese dioxide is formed on a dielectric film, and polypyrrole or polythiophene is laminated thereon by electrolytic polymerization to form a solid electrolyte.

[0004] However, in any of these methods, it is necessary to laminate polypyrrole or the like by an electrolytic reaction on a dielectric film which is not originally a conductor, and there is a problem in this point. That is, a chemically oxidized and polymerized film layer or a manganese dioxide layer must be provided on the dielectric film as a conductive layer to be an electrode for electrolytic polymerization. In this manner, electrolytic polymerization becomes possible only.

On the other hand, JP-A-3-35516 discloses that
A method has been proposed in which a polyaniline in a solution state is applied on a dielectric film and formed, and then the polyaniline film is immersed in a solution of protonic acid to perform a doping treatment. According to this method, a conductive polyaniline film can be formed on the dielectric film by a simple means without having to provide an electrode, which is advantageous in terms of manufacturing efficiency and cost.

[0006]

However, the doping treatment of the polyaniline film in a protonic acid solution involves the following steps.
It takes several hours to several days. As described above, the need for a long time for the doping treatment is not only undesirable from the viewpoint of the production efficiency, but also the protonic acid may penetrate from the polyaniline film and corrode the film-forming metal serving as the anode of the solid electrolytic capacitor. There is also.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem in the production of a solid electrolytic capacitor using a conventional conductive polyaniline film as a solid electrolyte. A method for forming a solid electrolytic capacitor using a conductive polyaniline film as a solid electrolyte by forming on a dielectric film by a simple method, thus solving the disadvantageous manufacturing problem that requires a long time for the doping process described above. An object is to provide a method that can be manufactured well.

[0008]

According to the present invention, there is provided a method for manufacturing a solid electrolytic capacitor, comprising forming a dielectric oxide film on a film-forming metal, and forming a general formula on the dielectric oxide film.

[0009]

Embedded image

(Wherein m and n represent the molar fractions of the quinone diimine structural unit and the phenylenediamine structural unit in the repeating unit, respectively; 0 <m <1, 0 <n <1, m +
n = 1. ) Having a quinonediimine structural unit and a phenylenediamine structural unit as main repeating units, and applying a solution of polyaniline that is soluble in an organic solvent and drying to form a polyaniline film. The polyaniline film is made conductive by treating with a dope solution containing an acid and an oxidizing agent, and this is used as a solid electrolyte.

In the present invention, the film-forming metal includes
Generally, aluminum or tantalum is used,
If necessary, a composite such as another metal or alloy can be used. A dielectric film is formed on such a film-forming metal to form an anode of an electrolytic capacitor. The polyaniline used in the present invention is a polyaniline that is soluble in a solvent in an undoped state and is represented by the general formula (I). The production of polyaniline, the method of dedoping, the solubility in a solvent, and the like are described in detail in JP-A-3-28229. In particular,
The polyaniline used in the present invention has an intrinsic viscosity [η] of 0.40 measured at 30 ° C. in N-methylpyrrolidone.
It is preferably at least dl / g. Thus, as described in detail in JP-A-3-28229, the polyaniline used in the present invention is distinguished by being higher in molecular weight and more solvent-soluble than conventionally known polyaniline. , And can also be distinguished structurally.

A polymer having a quinone diimine structural unit represented by the above general formula (I) and a phenylenediamine structural unit as a main repeating unit used in the present invention, which is polyaniline (hereinafter referred to as polyaniline) which is soluble in an organic solvent in an undoped state. , Undoped polyaniline), as described in detail in JP-A-3-28229, in a solvent in the presence of a protonic acid having an acid dissociation constant pKa value of 3.0 or less. While maintaining the temperature of aniline at 5 ° C. or lower, preferably at 0 ° C. or lower, the oxidizing agent having a standard electrode potential of 0.6 V or higher, which is defined as an electromotive force in a reduction half-cell reaction based on a standard hydrogen electrode, An equivalent amount defined as the amount of the aqueous solution divided by one mole of the oxidizing agent per mole of aniline divided by the number of electrons required to reduce one molecule of the oxidizing agent, Over 2 equivalents, preferably 2 to 2.5 equivalents, to produce an oxidized polymer of aniline doped with the above protonic acid (hereinafter referred to as doped polyaniline). Can be obtained by undoping with a basic substance.

As described above, polyaniline is obtained by oxidative polymerization of aniline in the presence of a protonic acid, and then polyaniline obtained by undoping this polyaniline has a high molecular weight and is soluble in various organic solvents. Dissolve. Such organic solvents include N-methyl-2-pyrrolidone,
Examples thereof include N, N-dimethylacetamide, N, N-dimethylformamide, dimethylsulfoxide, 1,3-dimethyl-2-imidazolidinone, and sulfolane.
The solubility depends on the average molecular weight of the undoped polyaniline and the solvent, but 0.5 to 100% of the polymer is dissolved.
A solution of 溶液 30% by weight can be obtained. In particular, undoped polyaniline has a high solubility in N-methyl-2-pyrrolidone, and usually 20 to 100% of the polymer dissolves to obtain a 3 to 30% by weight solution. However, it does not dissolve in tetrahydrofuran, 80% acetic acid aqueous solution, 60% formic acid aqueous solution, acetonitrile and the like.

Further, according to the present invention, the polyaniline in the undoped state can be partially or completely reduced using a reducing agent. The degree of reduction of the polyaniline can be adjusted by selecting an equivalent ratio of the reducing agent to be used to polyaniline. The degree of reduction of the polyaniline is determined by converting polyaniline to N-methyl-
It can be evaluated from the electronic spectrum of a solution dissolved in 2-pyrrolidone. Solvent soluble polyaniline N
-Methyl-2-pyrrolidone solution has an electronic spectrum of 3
It has maximum absorption at 40 nm and 640 nm. If the polyaniline represented by the general formula (I) is completely reduced, the absorption at 640 nm disappears and the intensity of the absorption at 340 nm increases, so that the absorption at 640 nm is derived from the quinone diimine structure, and the absorption at 340 nm is phenylenediamine. It is thought to be derived from the structure.

For such reduction of polyaniline, hydrazines such as hydrazine hydrate and phenylhydrazine, metal hydrides such as lithium aluminum hydride and lithium borohydride, and hydrogen are preferably used. Organic solvents, in particular, soluble in N-methyl-2-pyrrolidone, but does not reduce N-methyl-2-pyrrolidone,
Phenylhydrazine is most preferably used.

In the present invention, the solvent-soluble polyaniline in the polyaniline represented by the general formula (I) is a mole fraction n of a phenylenediamine structural unit.
Is preferably larger than the molar fraction m of the quinonediimine structural unit, and, as described above, those obtained by partially or completely reducing the polyaniline are preferably used.

According to the method of the present invention, first, a dielectric film is formed on a film-forming metal, and then a film made of polyaniline as described above is formed on the dielectric film. A solid electrolytic capacitor can be obtained by making it conductive by doping and making it a solid electrolyte. To form a polyaniline film, specifically, a solution of the polyaniline represented by the above general formula (I) is applied on a dielectric film, or the solution of the polyaniline is applied to the dielectric film under normal pressure or vacuum. Then, the solvent may be dried under normal pressure or under vacuum. The polyaniline film thus obtained is still in the undoped state and has no conductivity.

In the present invention, the dope used for doping the polyaniline film formed as described above is a mixed solution containing a protonic acid and an oxidizing agent. The protonic acid that can be used in the present invention is not particularly limited as long as it can dope such a polyaniline film.
4.8 or less is preferable, and organic polyvalent sulfonic acid is preferable in order to impart various required durability such as heat resistance, water resistance, and moist heat resistance to the obtained solid electrolytic capacitor. This organic polysulphonic acid may be an aromatic polysulphonic acid or an aliphatic polysulphonic acid.

The aromatic polysulfonic acid which can be suitably used in the present invention includes, for example, benzenedisulfonic acid, naphthalenedisulfonic acid, naphthalenetrisulfonic acid, naphthalenetetrasulfonic acid, anthracenedisulfonic acid, anthraquinonedisulfonic acid, phenanthrene Disulfonic acid, fluorenone disulfonic acid, carbazole disulfonic acid, diphenylmethane disulfonic acid, biphenyl disulfonic acid, terphenyldisulfonic acid, terphenyltrisulfonic acid, naphthalenesulfonic acid-formalin condensate, phenanthrenesulfonic acid-formalin condensate, anthracene Sulfonic acid-formalin condensate, fluorene sulfonic acid-formalin condensate, carbazole sulfonic acid-formalin condensate and the like can be mentioned. The position of the sulfonic acid group in the aromatic ring is arbitrary. The aromatic ring is an alkyl group, an alkoxy group,
It may contain a substituent such as a hydroxyl group, a nitro group, a cyano group, and an amino group.

The aliphatic polysulphonic acids which can be suitably used in the present invention include, for example, methanedisulfonic acid, 1,1-ethanedisulfonic acid, 1,2-ethanedisulfonic acid, 1,1-propane Disulfonic acid, 1,3-
Examples thereof include propane disulfonic acid and 2,2-propane disulfonic acid. Further, the organic polyvalent sulfonic acid used in the present invention may be a polymer acid. Examples of such a polymer acid include polyvinyl sulfonic acid, polyvinyl sulfate, polystyrene sulfonic acid, sulfonated styrene-butadiene copolymer, polyallyl sulfonic acid, polymethallyl sulfonic acid, and poly-2-acrylamido-2-methyl. Examples thereof include propanesulfonic acid, polyisoprenesulfonic acid, polysulfopropyl polyacrylate, and polysulfomethylstyrene.

As the oxidizing agent, a oxidizing agent which does not generate anions in the solution itself and the reduced form after the oxidation reaction is preferably used. Examples of such oxidizing agents include peroxides such as hydrogen peroxide and hydroperoxide, peracids such as m-chloroperbenzoic acid, p-benzoquinone, o-benzoquinone, p-toluquinone, oxy-p-benzoquinone. , 1,2
-Naphthoquinone, 1,4-naphthoquinone, diphenoquinone, stilbenequinone, chloranil, 2,3-dichloro-
Examples include quinones such as 5,6-dicyano-p-benzoquinone, sodium 1,2-naphthoquinone-4-sulfonate, sodium 1,4-naphthoquinone-2-sulfonate, and tetrafluoro-p-benzoquinone, and derivatives thereof. be able to.

According to the present invention, a dope solution is prepared by dissolving the oxidizing agent and the protonic acid as described above in a suitable solvent such as water, an organic solvent, or a mixture of water and an organic solvent. The polyaniline film is doped by bringing the dope solution into contact with the polyaniline film formed on the dielectric film as described above. The concentration of such a dope depends on the temperature of the doping treatment and the thickness of the formed polyaniline film.
The weight ratio of the oxidizing agent is preferably in the range of 1 to 30 wt%. More specifically, for example, when 1,2-ethanedisulfonic acid is used as the protonic acid and hydrogen peroxide is used as the oxidizing agent, the amount of 1,2-ethanedisulfonic acid is 5 to 30% by weight, Hydrogen oxide is preferably in the range of 3 to 30% by weight. When 1,5-naphthalenedisulfonic acid is used as the protic acid and p-benzoquinone is used as the oxidizing agent,
0% by weight and p-benzoquinone are preferably in the range of 1 to 8% by weight.

The temperature of the doping process is usually 1
It is in the range of 0-60 ° C. If the doping process is performed at a higher temperature, the required time can be shortened. However, if the temperature is too high, the mechanical strength of the polyaniline film is deteriorated. In the present invention, after a polyaniline film is formed on the dielectric film, the polyaniline film is treated with the above-described doping solution to perform a doping treatment. More specifically, the method may be such that the polyaniline film is immersed in the dope solution, the dope solution is applied to the polyaniline film, or the dope solution is sprayed.

According to the present invention, by making the dope solution a mixed solution containing an oxidizing agent together with a protonic acid, the doping speed of the polyaniline film is dramatically improved. This is because when an electron is deprived by an oxidizing agent from the lone pair of imino nitrogen in the reduced polyaniline moiety by an oxidizing agent, a cation radical called a semiquinone radical is generated, a charged site is generated, and an electrostatic field is formed, This is considered to be because the anion of the dopant is easily taken into the polyaniline by the electrostatic force. On the other hand, in the doping of a quinonediimine structure with a proton acid, such an electrostatic interaction does not work, and it depends only on the diffusion of the proton acid, so that the proton acid doping is considered to be slow.

After such a doping treatment, the polyaniline film is washed with an appropriate solvent such as ethanol and dried, and thereafter, a terminal is attached on the polyaniline film using a conductive paste such as carbon or silver. Next, it is molded with an epoxy resin or the like, and is subjected to an aging treatment.
Obtain a solid electrolytic capacitor. In the present invention, usually, aluminum or tantalum is preferably used as a metal for forming a film, and therefore, a film of aluminum oxide or tantalum oxide is generally preferably used as a dielectric film.

[0026]

As described above, according to the method of the present invention,
The polyaniline film formed on the dielectric film can be doped in a short time, and thus a solid electrolytic capacitor using the conductive polyaniline film as a solid electrolyte can be obtained easily and efficiently.

[0027]

The present invention will be described below with reference to Reference Examples and Examples, but the present invention is not limited thereto. Reference Example 1 (Production of quinone diimine / phenylenediamine type conductive polyaniline in a doped state by oxidative polymerization of aniline)
6000 g of distilled water was placed in a 10-liter separable flask equipped with a stirrer, a thermometer and a straight tube adapter.
360 ml of 6% hydrochloric acid and 400 g (4.295 mol) of aniline were charged in this order to dissolve the aniline. Separately, while cooling with ice water, distilled water 149 in a beaker was used.
434 g (4.295 mol) of 97% concentrated sulfuric acid was added to 3 g,
By mixing, an aqueous sulfuric acid solution was prepared. This aqueous sulfuric acid solution was added to the separable flask, and the entire flask was cooled to −4 ° C. in a low-temperature constant temperature bath.

Next, 980 g (4.295 mol) of ammonium peroxodisulfate was added to 2293 g of distilled water in a beaker and dissolved to prepare an aqueous solution of an oxidizing agent. The entire flask was cooled in a low-temperature constant temperature bath, and while maintaining the temperature of the reaction mixture at −3 ° C. or lower, the aqueous solution of ammonium peroxodisulfate was added to the acidic aqueous solution of the aniline salt from a straight tube adapter using a tubing pump while stirring. 1 ml
/ Min. Initially, the colorless and transparent solution changes from green-blue to black-green as the polymerization proceeds,
Subsequently, a black-green powder precipitated.

Although the temperature of the reaction mixture increased during the deposition of the powder, it was cooled and the temperature in the reaction system was lowered by -3.
C. or less. After powder deposition, the dropping rate of the aqueous solution of ammonium peroxodisulfate may be slightly increased, for example, to about 8 ml / min. However, also in this case, it is necessary to adjust the dropping speed so as to keep the temperature at −3 ° C. or lower while monitoring the temperature of the reaction mixture. After completion of the dropwise addition of the aqueous solution of ammonium peroxodisulfate over a period of 7 hours, stirring was continued for a further 1 hour at a temperature of -3C or lower.

The obtained polymer powder is separated by filtration, washed with water, washed with acetone, and vacuum-dried at room temperature to obtain a black-green quinonediimine / phenylenediamine type conductive polyaniline powder 4
30 g were obtained. This was pressed into a disc having a diameter of 13 mm and a thickness of 700 μm, and was subjected to the van der Pauw method by
The measured conductivity was 14 S / cm. (Production of Quinonediimine / Phenylenediamine Solvent-Soluble Polyaniline by Dedoping Conductive Organic Polymer) Doped Conductive Polyaniline Powder 35
0 g was added to 4 liters of 2N aqueous ammonia, and the mixture was stirred at 5,000 rpm for 5 hours with an auto homomixer. The mixture turned from black green to bluish purple.

The powder is filtered off with a Buchner funnel and washed repeatedly in distilled water with stirring in a beaker until the filtrate becomes neutral, and then washed with acetone until the filtrate becomes colorless. did. Thereafter, the powder was vacuum-dried at room temperature for 10 hours to obtain 280 g of a black-brown, undoped, solvent-soluble quinonediimine-phenylenediamine-type polyaniline powder. This polyaniline is N-methyl-2-
It is soluble in pyrrolidone and has a solubility of 100 g
8 g (7.4%). The intrinsic viscosity [η] measured at 30 ° C. using this as a solvent was 1.23.

Example 1 Etched aluminum (thickness: 70 μm, area: 1 cm ² ) was used as a metal for forming a film.
A DC voltage of 50 V was applied in a 3% by weight aqueous solution of ammonium adipate to form an insulating film (dielectric film).
The capacitor was used as an anode body. 5 g of the above-mentioned soluble polyaniline was dissolved in 95 g of N-methyl-2-pyrrolidone with stirring to obtain a 5% by weight polyaniline solution. Furthermore,
0.75 g of phenylhydrazine was gradually added thereto. At this time, the solution changed color from dark blue to black-brown, and at the same time, generation of nitrogen gas was confirmed. This solution was filtered under reduced pressure with a G2 glass filter.

After immersing the capacitor anode body in the polyaniline solution at room temperature for one minute, a hot air circulating drier (15
(0 ° C.) for 30 minutes to form a polyaniline film on the anode body. This operation was repeated three times in total. The capacitor anode body obtained by laminating the polyaniline film thus obtained was placed in a 40 ° C. aqueous solution containing 15% by weight of 1,2-ethanedisulfonic acid and 3.8% by weight of hydrogen peroxide.
After immersion for 0 minutes and doping treatment, the substrate was washed with ethanol and dried at 60 ° C. for 20 minutes. Thereafter, a conductive paste was applied, and electrode terminals were attached.

The solid electrolytic capacitor thus obtained had a capacitance of 5.75 μF at 120 Hz and a loss angle tangent (tan δ) of 5.5%. Also,
Equivalent series resistance (ESR) at 1 MHz is 165 mΩ
It was.

Example 2 The same 5% by weight polyaniline solution as in Example 1 was applied on the same anode body as in Example 1, and after degassing in a vacuum dryer,
It was heated in the same vacuum dryer, kept at 130 ° C. for 20 minutes and dried to form a polyaniline film on the anode body.
The obtained capacitor anode body having the polyaniline film formed thereon was prepared by adding 15% by weight of 1,2-ethanedisulfonic acid.
It was immersed in a 40 ° C. ethanol / water mixed solution containing p-benzoquinone and 2.0% by weight of p-benzoquinone for 30 minutes to perform doping treatment, washed with ethanol, and dried at 60 ° C. for 20 minutes. Thereafter, a conductive paste was applied, and electrode terminals were attached.

The solid electrolytic capacitor thus obtained had a capacitance of 6.39 μF at 120 Hz and a loss angle tangent (tan δ) of 4.2%. Also,
Equivalent series resistance (ESR) at 1 MHz is 130 mΩ
It was.

Example 3 The same 5% by weight polyaniline solution as in Example 1 was applied on the same anode body as in Example 1, and after degassing in a vacuum dryer,
It was heated in the same vacuum dryer, kept at 130 ° C. for 20 minutes and dried to form a polyaniline film on the anode body.
The obtained capacitor anode body having the polyaniline film formed thereon was prepared by adding 15% by weight of 1,2-ethanedisulfonic acid.
And sodium 1,2-naphthoquinone-4-sulfonate 2.5
The resultant was immersed in an N-methylformamide / water mixed solution containing 50% by weight at 40 ° C. for 60 minutes to perform doping treatment, washed with ethanol, and dried at 60 ° C. for 20 minutes. Thereafter, the terminals were attached in the same manner as in Example 1.

The solid electrolytic capacitor thus obtained had a capacitance of 6.12 μF at 120 Hz and a loss angle tangent (tan δ) of 3.4%. Also,
Equivalent series resistance (ESR) at 1 MHz is 168 mΩ
It was.

Example 4 The same 5% by weight polyaniline solution as in Example 1 was applied on the same anode body as in Example 1, and after degassing in a vacuum dryer,
It was heated in the same vacuum dryer, kept at 130 ° C. for 20 minutes and dried to form a polyaniline film on the anode body.
The thus obtained capacitor anode body having the polyaniline film formed thereon was treated with 10% by weight of polyvinyl sulfonic acid and p
After being immersed in an ethanol / water mixed solution containing 2.5% by weight of benzoquinone at 40 ° C. for 60 minutes to perform doping treatment, the substrate was washed with ethanol and dried at 60 ° C. for 20 minutes. Thereafter, the terminals were attached in the same manner as in Example 1.

The solid electrolytic capacitor thus obtained had a capacitance of 6.06 μF at 120 Hz and a loss angle tangent (tan δ) of 6.3%. Also,
Equivalent series resistance (ESR) at 1 MHz is 147 mΩ
It was.

Example 5 A porous sintered body ( volume: 20.8 mm ³ ) obtained by sintering fine powder of tantalum was used as a film-forming metal, and a DC voltage was applied in a 0.3% by weight aqueous phosphoric acid solution at 90 ° C. A voltage of 100 V was applied to form an insulating film (dielectric film), which was used as an anode of a capacitor. The above-mentioned soluble polyaniline was dissolved in N-methyl-2-pyrrolidone with stirring to obtain a 10% by weight polyaniline solution. After the capacitor anode body was immersed in the polyaniline solution for 1 minute, a hot air circulating drier (150
C.) for 30 minutes to form a polyaniline film on the anode body. It was repeated three times in total this operation.

The thus obtained capacitor anode having the polyaniline film formed thereon contained 40% by weight of 15% by weight of 1,2-ethanedisulfonic acid and 2.0% by weight of p-benzoquinone.
Immersed in an ethanol / water mixed solution at 30 ° C. for 30 minutes, and then washed with ethanol;
Dried for minutes. Thereafter, a conductive paste was applied, and electrode terminals were attached. The solid electrolytic capacitor thus obtained had a capacitance of 23.8 μF at 120 Hz and a loss angle tangent (tan δ) of 1.5%.
The equivalent series resistance (ESR) at 1 MHz is 32
It was 8 mΩ.

[0043] The aluminum to a cathode body to the same anode body and Comparative Example 1 Example 1
And place a separator between the anode body and 5% by weight.
Of ammonium adipate in water / ethylene glycol mixture
It was immersed in the mixed solution, and the separator was impregnated with the solution. Anode and
Terminals were drawn from both aluminum of the cathode and the cathode. This
The obtained wet electrolytic capacitor is
Has a capacitance of 6.44 μF and the tangent of the loss angle
(Tan δ) was 8.0%. Also at 1 MHz
The equivalent series resistance (ESR) was 1220 mΩ. Comparative Example 2 After the same anode body as in Example 5 was impregnated with an aqueous solution of manganese nitrate, a manganese dioxide layer was formed as a solid electrolyte by a thermal decomposition treatment. Furthermore, after performing re-chemical formation, the electrode terminals were attached with a conductive paste. The solid electrolytic capacitor thus obtained has a capacitance of 21.4 μF at 120 Hz and a tangent (tan) of the loss angle.
δ) was 5.1%. The equivalent series resistance (ESR) at 1 MHz was 984 mΩ.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Akira Otani 1-1-2 Shimohozumi, Ibaraki-shi, Osaka Nitto Denko Corporation (56) References JP 3-35516 (JP, A) JP Hei 3-28229 (JP, A) (58) Fields surveyed (Int. Cl. ⁷ , DB name) H01G 9/28-9/02 331

Claims (5)

(57) [Claims] A dielectric oxide film is formed on a film-forming metal, and a general formula is formed on the dielectric oxide film. (In the formula, m and n each represent a mole fraction of the quinone diimine structural unit and the phenylenediamine structural unit in the repeating unit, and are represented by 0 <m <1, 0 <n <1, and m + n = 1.) Having a quinone diimine structural unit and a phenylenediamine structural unit as main repeating units,
Apply a solution of polyaniline that is soluble in an organic solvent,
Drying to form a polyaniline film, and then treating the polyaniline film with a dope solution containing a protonic acid and an oxidizing agent to make the polyaniline film conductive and to make it a solid electrolyte. To manufacture solid electrolytic capacitors. 2. Polyaniline which is soluble in an organic solvent is N
The method for producing a solid electrolytic capacitor according to claim 1, wherein the intrinsic viscosity [η] measured at 30 ° C in -methyl-2-pyrrolidone is 0.40 dl / g or more. 3. The method according to claim 1, wherein the protonic acid is an organic polysulfonic acid. 4. The method for producing a solid electrolytic capacitor according to claim 1, wherein the oxidizing agent itself and the reduced form after the oxidation reaction do not generate anions in the solution. 5. The method according to claim 4, wherein the oxidizing agent is a peroxide-based oxidizing agent or a quinone-based oxidizing agent.