JPH0541338A - Solid electrolytic capacitor and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain a solid electrolytic capacitor, which is superior in adhesion to a dielectric film, by a method wherein a conductive polyaniline film having a polysulfonic acid as a dopant is formed as a solid electrolyte. CONSTITUTION:A sulfonic acid having two pieces or more of sulfonic groups in its molecules is doped to a polyaniline having the formula [0<m<1, 0<n<1, m+n=1] as its main repeat unit as a solid electrolyte on a dielectric oxide film formed on a film-forming metal film to form a conductive high-molecular film. This polyaniline is soluble to an organic solvent in a state that it is dedoped and in a parasubstituted benzene skeletal structure in a laser Raman spectrum obtainable by exciting with the light of a wavelength of 457.9nm, the ratio 1a to 1b of the intensity 1a of Raman rays in a skelton stretching vibration to appear in the number of waves higher than those of 1600cm<-1> to the intensity 1b of Raman rays in a skelrton stretching vibration to appear in the number of waves lower than those of 1660cm<-1> is 1:1.0 or higher.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid electrolytic capacitor using a conductive organic polymer as a solid electrolyte and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, electrolytic capacitors known as large-capacity capacitors include an electrolytic solution type and a solid type. Among them, as a solid-state capacitor using a solid electrolyte, a method using manganese dioxide or 7,7,8,8-tetracyanoquinodimethane (TCNQ) complex is known, but the former has a large impedance, The latter is
It has various problems such as poor thermal stability.

Therefore, in recent years, various solid electrolytic capacitors using a conductive organic polymer as a solid electrolyte have been proposed. For example, in Japanese Patent Laid-Open No. 63-158829, aluminum is vacuum-deposited on an aluminum foil having an aluminum oxide dielectric formed on its surface, and this is used as an anode, and a pyrrole is formed together with a supporting electrolyte between a cathode made of stainless steel and the cathode. It is described that a solid electrolytic capacitor is obtained by electrolytically oxidizing an aqueous solution containing a to form a film of conductive polypyrrole on the anode.

According to this method, however, since the aluminum oxide dielectric film is insulative, in order to form a thin film of conductive polypyrrole thereon by electrolytic polymerization,
Work such as vapor deposition of aluminum on the surface of the dielectric film in advance is required, the manufacturing process is complicated, and the manufacturing cost is inevitably high.

[0005]

DISCLOSURE OF THE INVENTION The present inventors have found that an organic solvent-soluble polyaniline having a very high molecular weight is cast and coated on an appropriate base material so as to be self-supporting. That a transparent film or thin film can be obtained,
Furthermore, it has been found that conductivity can be imparted by doping these films and films with a protonic acid having a pKa value of 4.8 or less.

On the other hand, in order to obtain a solid electrolytic capacitor that can be used practically, the conductive polymer is required to have durability in various environments, and among them, water resistance and heat resistance are extremely important. In this regard, conventionally, polyaniline has
Similarly, it is said that it is inferior in water resistance to polypyrrole known as a conductive polymer. That is, when the polyaniline doped with a protonic acid comes into contact with water, the protonic acid is dedoped and the conductivity is lowered.

[0007] Therefore, the present inventors further researched the above-mentioned organic solvent-soluble polyaniline, and earnestly studied to obtain a conductive polyaniline excellent in heat resistance and water resistance. As a result, the organic solvent-soluble polyaniline was obtained. Can be dissolved in an organic solvent together with a polysulfonic acid having two or more sulfonic acid groups in the molecule (hereinafter, this may be simply referred to as polysulfonic acid), and thus the solution is flowed on the dielectric film. A conductive polyaniline film having the above-mentioned polysulfonic acid as a dopant can be obtained by a much simpler method as compared with the method involving electrolytic oxidation of a polymerizable monomer as described above by spreading and drying. Is formed as a solid electrolyte, has excellent adhesion to the dielectric film, has a low impedance in the high frequency range, and has a low capacitance. With hearing, we have found that it is possible to obtain a solid electrolytic capacitor having excellent durability and reliability, but was Itaritsu the present invention.

[0008]

The solid electrolytic capacitor according to the present invention comprises a dielectric oxide film formed on a film-forming metal, and a solid electrolyte on the dielectric oxide film of the general formula

[0009]

[Chemical 1]

(In the formula, m and n respectively represent the mole fractions of the quinonediimine structural unit and the phenylenediamine structural unit in the repeating unit, and 0 <m <1, 0 <n <1, m +
n = 1. ) As the main repeating unit, which is soluble in an organic solvent in the undoped state and is excited by light having a wavelength of 457.9 nm, and is obtained by excitation with light having a wavelength of 457.9 nm. Raman line intensity Ia of skeletal stretching vibration that appears at a wave number higher than 1600 cm ^-1 and 1600 cm
^-1 A sulfonic acid having two or more sulfonic acid groups in the molecule is doped into an organic solvent-soluble polyaniline having a ratio Ia / Ib of Raman line intensities Ib of skeletal stretching vibration appearing at a wave number lower than ^-1 is 1.0 or more. It is characterized in that a film of a conductive polymer is formed.

The solid electrolytic capacitor according to the present invention has the general formula

[0012]

[Chemical 1]

(In the formula, m and n represent the mole fractions of the quinonediimine structural unit and the phenylenediamine structural unit in the repeating unit, respectively, 0 <m <1, 0 <n <1, m +
n = 1. ) As the main repeating unit, which is soluble in an organic solvent in the undoped state and is excited by light having a wavelength of 457.9 nm, and is obtained by excitation with light having a wavelength of 457.9 nm. Raman line intensity Ia of skeletal stretching vibration that appears at a wave number higher than 1600 cm ^-1 and 1600 cm
^A polyaniline having a Raman line intensity Ib ratio of skeletal stretching vibration Ia / Ib of 1.0 or more which appears at a wave number lower than ^-1 is dissolved in an organic solvent together with a polysulfonic acid having two or more sulfonic acid groups in the molecule. It can be obtained by applying the obtained solution on the dielectric film and drying it to form a film of conductive polyaniline on the dielectric film.

Particularly in the present invention, the polyaniline preferably has an intrinsic viscosity [η] measured at 30 ° C. in N-methyl-2-pyrrolidone of 0.40 dl / g or more. In the present invention, the conductive polymer composed of polyaniline used as the solid electrolyte is represented by the general formula

[0015]

[Chemical 1]

(In the formula, m and n respectively represent the mole fractions of the quinonediimine structural unit and the phenylenediamine structural unit in the repeating unit, and 0 <m <1, 0 <n <1, m +
n = 1. ) As the main repeating unit, which is soluble in an organic solvent in the undoped state and is excited by light having a wavelength of 457.9 nm, and is obtained by excitation with light having a wavelength of 457.9 nm. Raman line intensity Ia of skeletal stretching vibration that appears at a wave number higher than 1600 cm ^-1 and 1600 cm
^{-1 An} organic solvent-soluble polyaniline having a Raman line intensity Ib ratio of skeletal stretching vibration Ia / Ib of 1.0 or more, which appears at a wave number lower than ^-1, is doped with polysulfonic acid having two or more sulfonic acid groups in the molecule. It will be.

In order to form a conductive polymer composed of polyaniline as described above on a dielectric film, first, a conductive oxide polymer of aniline doped with a protonic acid is prepared and dedoped. To prepare a polyaniline soluble in an organic solvent, then dissolve the polyaniline soluble in an organic solvent in a solvent together with a polysulfonic acid as a dopant to form a solution, and cast or coat the solution on the dielectric film and dry it. As a conductive film or film.

First, the conductive oxidation polymer of aniline doped with the above-mentioned protonic acid has an acid dissociation constant pKa value of
Electromotive force in a reducing half-cell reaction based on a standard hydrogen electrode, while maintaining the temperature of aniline in a solvent in the presence of a protonic acid of 3.0 or less at 5 ° C or less, preferably 0 ° C or less. Is defined as the amount of an aqueous solution of an oxidant having a standard electrode potential of 0.6 V or more defined as 1 mole of oxidant divided by the number of electrons required to reduce 1 molecule of the oxidant per mole of aniline. It can be obtained by oxidative polymerization of aniline by gradually adding 2 equivalents or more, preferably 2 to 2.5 equivalents in equivalents.

Next, by dedoping the oxidized polymer of aniline doped with a protonic acid with a basic substance, an organic solvent-soluble polyaniline can be obtained. In the oxidative polymerization of aniline, manganese dioxide, ammonium peroxodisulfate, hydrogen peroxide, ferric salts, iodates and the like are particularly preferably used as the oxidizing agent. Among these, for example,
Since ammonium peroxodisulfate and hydrogen peroxide both involve two electrons per molecule in the oxidation reaction, an amount of 1 to 1.25 mol is usually used for 1 mol of aniline.

The protonic acid used in the oxidative polymerization of aniline is not particularly limited as long as it has an acid dissociation constant pKa value of 3.0 or less. For example, hydrochloric acid, sulfuric acid, nitric acid, perchloric acid, Inorganic acids such as borohydrofluoric acid, phosphorus hydrofluoric acid, hydrofluoric acid and hydroiodic acid, aromatic sulfonic acids such as benzenesulfonic acid and p-toluenesulfonic acid, alkanes such as methanesulfonic acid and ethanesulfonic acid Examples thereof include phenols such as sulfonic acid and picric acid, aromatic carboxylic acids such as m-nitrobenzoic acid, and aliphatic carboxylic acids such as dichloroacetic acid and malonic acid.
Further, a polymeric acid can also be used. Examples of the polymer acid include polystyrene sulfonic acid, polyvinyl sulfonic acid, polyallyl sulfonic acid, polyvinyl sulfuric acid and the like.

The amount of protonic acid used depends on the reaction mode of the oxidizing agent used. For example, in the case of manganese dioxide, the oxidation reaction is represented by MnO ₂ + 4H ⁺ + 2e ⁻ → Mn ²⁺ + 2H ₂ O, so at least 4
It is necessary to use a protic acid that can supply a double molar amount of protons. Also in the case of hydrogen peroxide, the oxidation reaction is represented by H ₂ O ₂ + 2H ⁺ + 2e ⁻ → 2H ₂ O, so a protonic acid capable of supplying at least twice the molar amount of protons as the hydrogen peroxide used is used. There is a need. On the other hand, in the case of ammonium peroxodisulfate,
Since the oxidation reaction is represented by S ₂ O ₈ ²⁻ + 2e ⁻ → 2SO ₄ ²⁻ , it is not necessary to use a protic acid. However, even when ammonium peroxodisulfate is used as the oxidizing agent, it is preferable to use a protic acid in an equimolar amount to the oxidizing agent.

As a solvent in the oxidative polymerization of aniline, aniline, a protonic acid and an oxidizing agent are dissolved, and
A substance that is not oxidized by an oxidizing agent is used. Water is most preferably used, however, if necessary, alcohols such as methanol and ethanol, nitriles such as acetonitrile, N-methyl-2-pyrrolidone, polar solvents such as dimethyl sulfoxide, ethers such as tetrahydrofuran, Organic acids such as acetic acid can also be used.
Also, a mixed solvent of these organic solvents and water can be used.

In preparing the organic solvent soluble polyaniline, it is important to keep the temperature of the reaction mixture below 5 ° C. during the reaction, especially during the addition of the oxidant solution to the aniline solution. Therefore, the oxidant solution should be added slowly to the aniline so that the temperature of the reaction mixture does not exceed 5 ° C. When adding the oxidizer rapidly,
Even by external cooling, the temperature of the reaction mixture rises to form a low molecular weight polymer, or a solvent-insoluble oxidized polymer is formed even after dedoping described later.

In particular, in the above reaction, it is preferable to keep the reaction temperature at 0 ° C. or lower, whereby, after dedoping, the temperature was measured at 30 ° C. in N-methyl-2-pyrrolidone (hereinafter, The same.) It is possible to obtain a high molecular weight organic solvent-soluble polyaniline having an intrinsic viscosity [η] of 1.0 dl / g or more. In this way, polyaniline doped with the protonic acid used can be obtained. In the doped state, this polyaniline does not dissolve in an organic solvent, which will be described later, because it forms a salt with a protonic acid. It is well known that salts of high molecular weight amines are generally sparingly soluble in organic solvents. However, the organic solvent-soluble polyaniline can be obtained by dedoping the organic solvent-insoluble polyaniline.

Since the dedoping of polyaniline doped with this protonic acid is a kind of neutralization reaction, it is particularly limited as long as it is a basic substance capable of neutralizing the protonic acid as a dopant. However, preferably, a metal hydroxide such as aqueous ammonia, sodium hydroxide, potassium hydroxide, lithium hydroxide, magnesium hydroxide or calcium hydroxide is used. In the dedoping, the basic substance may be added directly to the reaction mixture after the above-mentioned oxidative polymerization of aniline, or the basic substance may be allowed to act after the polymer is once isolated.

The polyaniline in the doped state obtained by the oxidative polymerization of aniline usually has an electric conductivity of 10 ^-6 S / cm or more and exhibits a black green color.
Purple or purple is the last copper color. This discoloration is because the amine nitrogen of the salt structure in the polymer was changed to a free amine. The electrical conductivity is usually on the order of 10 ^-10 S / cm. The undoped polyaniline thus obtained has a high molecular weight and is soluble in various organic solvents. As such an organic solvent, 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 polymer and the solvent, but 0.5 to 100% of the polymer dissolves and a solution of 1 to 30% by weight can be obtained. In particular, this undoped polyaniline shows high solubility in N-methyl-2-pyrrolidone, and usually 20 to 100% of polyaniline is dissolved and
~ 30 wt% solution can be obtained. However, tetrahydrofuran, 80% acetic acid aqueous solution, 60% formic acid aqueous solution,
It does not dissolve in acetonitrile.

Therefore, by dissolving the organic solvent-soluble polyaniline in an organic solvent and casting it, a self-supporting flexible and tough film can be obtained. In order to obtain a tough film in such film formation or thin film formation, the organic solvent-soluble polyaniline is N
-Methylpyrrolidone having an intrinsic viscosity [η] measured at 30 ° C. of not less than 0.40 dl / g is preferably used.

Furthermore, the film obtained by casting the solvent-soluble aniline oxide polymer has different properties depending on the drying conditions of the solvent. Usually, when a soluble polymer N-methyl-2-pyrrolidone solution having an intrinsic viscosity [η] of 0.40 dl / g or more is cast on a glass plate and the solvent is dried, the drying temperature is 100 ° C or less. When, the strength of the obtained film is still not sufficiently high, and it is partially soluble in N-methyl-2-pyrrolidone. However, when the drying temperature is 130 ° C. or higher, the obtained film has excellent flexibility, is extremely tough, and does not crack even when bent. Further, the film thus obtained is insoluble in N-methyl-2-pyrrolidone and also in concentrated sulfuric acid. As described above, the solvent insolubilization of the polymer due to drying at a high temperature after casting is considered to be because the polymer molecule is cross-linked by the coupling of radicals existing in the polymer or generated during heating. ..

The soluble polyaniline is analyzed by elemental analysis, infrared absorption spectrum, ESR spectrum, laser Raman spectrum, thermogravimetric analysis, solubility in solvent, and visible to near infrared absorption spectrum.

[0030]

[Chemical 1]

(In the formula, m and n respectively represent the mole fractions of the quinonediimine structural unit and the phenylenediamine structural unit in the repeating unit, and 0 <m <1, 0 <n <1, m +.
n = 1. ) As a main repeating unit. The film obtained by solvent insolubilization from the solvent-soluble polyaniline by the casting method also shows substantially the same infrared absorption spectrum as the solvent-soluble polyaniline, and also elemental analysis, infrared absorption spectrum, ESR spectrum, laser Raman spectrum, From thermogravimetric analysis, solubility in a solvent, visible to near-infrared absorption spectrum, and the like, it is considered that they have a cross-linked structure but substantially the same repeating unit.

In the solvent-soluble polyaniline represented by the above general formula, the values of m and n can be adjusted by oxidizing or reducing the polymer. That is, by reducing, m can be reduced and n can be increased. On the contrary, if oxidized, m can be increased and n can be decreased. Reduction of the quinonediimine structural unit in the polymer due to the reduction of the polymer increases the solubility of the polymer in a solvent. Further, the viscosity of the solution is lower than that before the reduction.

For the reduction of such solvent-soluble polyaniline, hydrazines such as hydrazine hydrate and phenylhydrazine, metal hydrides such as lithium aluminum hydride and lithium borohydride, and hydrogen are preferably used. .. Phenylhydrazine is most preferably used because it dissolves in an organic solvent, particularly N-methyl-2-pyrrolidone, but does not reduce N-methyl-2-pyrrolidone. On the other hand, the oxidizing agent used for the oxidation of the solvent-soluble polyaniline is arbitrary as long as it can oxidize the phenylenediamine structural unit in the general formula, but it does not occur in the reducing half-cell reaction based on the standard hydrogen electrode. An oxidant having a standard electrode potential defined as electric power of 0.3 V or more is particularly preferably used. For example, silver oxide which is a mild oxidizing agent is preferably used. Blowing oxygen is also useful. As a strong oxidizing agent, for example, potassium permanganate, potassium dichromate, etc. can be used, but it is necessary to prevent deterioration of the polymer when using them. Thus, reducing solvent soluble polyaniline is useful in reducing the viscosity of the solution.

In the reduction of the polyaniline, when a reducing agent is used in excess, most of the quinonediimine structural units in the polymer are reduced, so that a semiquinone radical (polaron structure) is formed by doping the quinonediimine structural unit. There is less production, and thus the conductivity of the resulting conductive organic polymer is not so high immediately after its doping. However, by allowing the doped polymer to stand in the air, the reduced phenylenediamine structural unit gradually returns to the quinonediimine structural unit by air oxidation, and the protonic acid remaining in the polymer layer is formed. Therefore, since it is doped with semi-quinone radicals, highly conductive polyaniline can be obtained.

The characteristics of the organic solvent-soluble polyaniline obtained from the laser Raman spectrum are as follows.
While comparing with so-called polyaniline which has been known from the past,
explain. Generally, there is vibration spectroscopy as a means for obtaining information on vibration between atoms constituting a substance, and there are infrared spectroscopy and Raman spectroscopy. Infrared spectroscopy is active in vibration modes that result in changes in dipole moment, and Raman spectroscopy is active in vibrations that result in changes in polarizability. Therefore, the two have a complementary relationship, and in general, the vibration mode strongly appearing in infrared spectroscopy is weak in Raman spectroscopy, while the vibration mode strongly appearing in Raman spectroscopy is in infrared spectroscopy. weak.

The infrared absorption spectrum is obtained by detecting the energy absorption between the vibrational levels, and the Raman spectrum shows the higher vibrational levels of the ground state after the molecule is excited by light irradiation. It is obtained by detecting scattered light (Raman scattering) that occurs when the light falls. At this time, the vibration energy level can be known from the energy difference between the scattered light and the irradiation light.

Raman spectra are usually obtained by excitation with visible light from an argon laser or the like. Here, it is known that when the sample has an absorption band in the visible region, a very strong Raman line can be obtained when the irradiation laser beam and the absorption band wavelength are matched. This phenomenon is called the resonance Raman effect, and according to this, a strong Raman line 10 ⁴ to 10 ⁵ times as strong as a normal Raman line can be obtained. According to the resonance Raman effect, the information of the chemical structure portion excited by the wavelength of the irradiated laser light is more emphasized and obtained. Therefore, the chemical structure of the sample can be analyzed more accurately by measuring the Raman spectrum while changing the wavelength of the laser light to be irradiated. Such a feature is a feature of Raman spectroscopy that is not found in infrared spectroscopy.

FIG. 1 shows a disk of a non-doped polyaniline powder which is soluble in an organic solvent and has an intrinsic viscosity [η] of 1.2 dl / g measured at 30 ° C. in N-methyl-2-pyrrolidone. Excitation wavelength of 4
It is a laser Raman spectrum obtained by irradiating with 57.9 nm. The attribution of the Raman line is as follows. 162
2 and 1591 cm ^-1 are skeleton stretching vibrations of para-substituted benzene, 1489 and 1479 cm ^-1 are C = C and C = N stretching vibrations of quinonediimine structure, 1220 cm ^-1 is C-N.
Stretching vibration and CC stretching vibration mixed, 1185 and 116
5 cm ^-1 is the in-plane bending vibration of C-H.

FIG. 2 shows Y. Furukawa et al., Synth. Me.
16 is a laser Raman spectrum obtained by irradiating an undoped polyaniline shown in T., 16 , 189 (1986) at an excitation wavelength of 457.9 nm. This polyaniline was obtained by electrolytic oxidative polymerization of aniline on a platinum electrode. As shown in FIG. 1, in the solvent-soluble, dedoped polyaniline used in the present invention, the Raman line intensity Ia of the skeletal stretching vibration that appears at a wave number higher than 1600 cm ^-1 among the skeletal vibrations of para-substituted benzene is shown. Raman line intensity I that appears at wave numbers lower than 1600 cm ^-1
The ratio Ia / Ib with b is 1.0 or more. On the contrary,
All of the conventionally known polyanilines including the polyaniline shown in FIG. 2, including those obtained by chemical oxidative polymerization, have the above ratio Ia / Ib smaller than 1.0.

The Raman lines at 1622 and 1591 cm ^-1 are
Both are based on the skeleton stretching vibration of para-substituted benzene. Since polyaniline in the reduced state does not have a quinonediimine structure, Raman lines are generated only at 1621 cm ⁻¹ , but in the undoped polyaniline having a quinonediimine structure, as described above, 1622 and 1
Raman lines appear at 591 cm ^-1 . These Raman lines exhibit excitation wavelength dependence as shown in FIG.

Excitation wavelength from 488.0 nm to 476.5 nm
Ia / Ib changes as the wavelength is changed to 457.9 nm on the short wavelength side. That is, at 488.0 nm, Ia / Ib is smaller than 1.0, but at 457.9 nm,
It is more than 1.0, compared to when it is 488.0 nm.
The Ia / Ib intensity is reversed. This reversal phenomenon can be explained as follows.

FIG. 4 shows an electronic spectrum of the solvent-soluble polyaniline. Since the peak at 647 nm disappears by reducing polyaniline, it is considered that it is derived from the quinonediimine structure, and the peak at 334 nm, on the contrary, increases in intensity by reducing polyaniline. It is thought to be derived from the π−π ^* transition. FIG. 4 shows the Raman excitation wavelength described above. here,
Regarding the band of the para-substituted benzene skeleton stretching vibration, when the excitation wavelength was changed from 488.0 nm to 457.9 nm on the short wavelength side, it was 16 bands compared with the band of 1591 cm ^-1.
It is considered that the resonance condition of the resonance Raman effect in the band of 22 cm ⁻¹ becomes more advantageous and the above-mentioned change in relative intensity occurs.

Next, in the spectra shown in FIGS. 1 and 2, the relative intensities of the Raman lines at 1591 cm ^-1 and 1622 cm ^-1 are different even though they have the same excitation wavelength (457.9 nm). It will be explained as follows. That is,
N, N'- as model compounds of phenylenediamine structure
Diphenyl-p-phenylenediamine has a Raman line only at 1617 cm ^-1 , and N, N'-diphenyl-p-benzoquinonediimine as a model compound having a quinonediimine structure has Raman lines at 1568 cm ^-1 and 1621 cm ^-1. Therefore, as shown in (a) below, the para-substituted benzene ring that is non-conjugated with the quinonediimine structure has a Raman line of 1622 cm ⁻¹ that is increased in intensity by excitation with short-wavelength light.
As shown in, the para-substituted benzene ring conjugated with the quinonediimine structure is presumed to have Raman lines of 1591 cm ⁻¹ and 1622 cm ⁻¹ .

[0044]

[Chemical 2]

From the results of elemental analysis, it is considered that the number of quinonediimines and the number of phenylenediamines are almost equal in the solvent-soluble polyaniline in the undoped state.
The structural chain of the solvent-soluble polyaniline in such a dedoped state is, from the coupling mode of the quinonediimine structure and the phenylenediamine structure, as shown in (c), the alternating copolymeric chain of the quinonediimine structure and the phenylenediamine structure,
As shown in (d), they are classified into two, that is, a block copolymeric chain of a quinonediimine structure and a phenylenediamine structure. In the figure, the para-substituted benzene ring indicated by an arrow represents a benzene ring which is non-conjugated with quinonediimine, and in the above alternating copolymeric chain, for example, there are two per octamer chain unit, and the block copolymerization In coalescing chains, for example, there are three per octamer chain unit. When the chain unit has a long length, the difference in the number of quinonediimines and non-conjugated benzene rings in both is further increased. This difference is 1
It can be said that this appears as a difference in relative intensity of Raman lines at 591 cm ^-1 and 1622 cm ^-1 .

[0046]

[Chemical 3]

Since the solvent-soluble polyaniline has an Ia / Ib ratio of 1.0 or more in the laser Raman spectrum, it contains a large amount of benzene rings which are non-conjugated with the quinonediimine structure, and thus the block copolymer is obtained. It seems to have a physical chain. The organic solvent solubility of polyaniline is reasonably explained by having such a block copolymeric chain. Generally, it is known that the imine nitrogen (-N =) in the quinone diimine structure forms a hydrogen bond with a secondary amino group hydrogen (-NH-) in the vicinity (Macromolecules, 21 , 1297).
(1988)), hydrogen bonds between secondary amino groups are not strong.

Therefore, when the polyaniline has the alternating copolymeric chains, a strong hydrogen bond network as shown in (f) is formed. It is considered that the conventionally known polyaniline is insoluble in many organic solvents even in the undoped state because it forms a network having a strong hydrogen bond. On the other hand, when the polymer chain is the block copolymeric chain as in the solvent-soluble polyaniline in the undoped state, the block chains usually have different lengths, and thus only the (e) is shown. As shown, even if the phenylenediamine structure part and the quinonediimine structure part are adjacent to each other, many hydrogen bonds cannot be formed, and the solvent penetrates between the polymer chains to form a hydrogen bond with the solvent. Then, it will be dissolved in the organic solvent.
If all parts of the block chain had exactly the same length, they would form a hydrogen bond network as described above, but since the probability of having such a structure is extremely small, it is usually ignored. obtain.

[0049]

[Chemical 4]

[0050]

[Chemical 5]

Furthermore, such interchain interactions are
From the C-H in-plane bending vibration of the Razer Raman spectrum
Explained. The polyaniline in the undoped state shown in FIG.
1162 cm attributed to C-H in-plane bending vibration of phosphorus^-1of
In Raman line, polyaniline is reduced and imine nitrogen is
1181 cm when converted to secondary amino nitrogen ^-1
Shift to high wave number.

As described above, the solvent-soluble polyaniline has a Raman line attributed to C—H in-plane bending vibration of 1165 and 1185 cm ^{−1 in} the undoped state.
There is one. This Raman line of 1185 cm ^-1 is not found in the conventionally known undoped polyaniline, and is close to 1181 cm ^-1 which is attributed to C-H in-plane bending vibration in the reduced state. Indicates the value.

From these points, it is considered that the solvent-soluble polyaniline has a block copolymer chain in the undoped state and has an atmosphere of a reduced structure. From this, it may have high solubility in organic solvents despite the high molecular weight. As described above, the solvent-soluble polyaniline used in the present invention is a novel polymer having a structural chain different from the conventionally known polyaniline.

As described above, since the aniline oxidation polymer has quinonediimine structural units and phenylenediamine structural units in the block copolymeric chain as described above as repeating units, it was doped with a protonic acid. In the state, it is described as having conductivity by only an acid-base reaction without involving a redox reaction.

This conduction mechanism was reported by AG MacDiarmid et al. (AG MacDiarmide et al., J. Chem. S.
oc., Chem. Commun., 1987 , 1784), the quinonediimine structure is protonated as shown below by doping with a protonic acid, and this has a semiquinone cation radical structure and is conductive. is there. Such a state is called a polaron state.

[0056]

[Chemical 6]

According to the present invention, the solvent-soluble polyaniline described above can be dissolved in an organic solvent together with a polysulfonic acid having two or more sulfonic acid groups in the molecule. Therefore, if such a solution of polyaniline is cast on the dielectric film and the solvent is removed by drying,
Immediately and easily, a conductive polyaniline film doped with the polysulfonic acid can be obtained, and thus,
A conductive polyaniline film can be formed directly on the dielectric oxide film.

In the present invention, the polysulfonic acid may be an aromatic polysulfonic acid or an aliphatic polysulfonic acid. Examples of the aromatic polysulfonic acid that can be preferably used in the present invention include benzenedisulfonic acid, naphthalene disulfonic acid, naphthalene trisulfonic acid, naphthalene tetrasulfonic acid, anthracene disulfonic acid, anthraquinone disulfonic acid, phenanthrene disulfonic acid, fluorenone disulfone. Acid, carbazole disulfonic acid, diphenylmethane disulfonic acid, biphenyl disulfonic acid, terphenyl disulfonic acid, terphenyl trisulfonic acid, naphthalene sulfonic acid-formalin condensate, phenanthrene sulfonic acid-formalin condensate, anthracene sulfonic acid-formalin condensation object,
Examples thereof include fluorene sulfonic acid-formalin condensate and carbazole sulfonic acid-formalin condensate. The position of the sulfonic acid group in the aromatic ring is arbitrary.

Examples of the aliphatic polysulfonic acid which can be preferably used in the present invention include methanedisulfonic acid, 1,1-ethanedisulfonic acid, 1,2-ethanedisulfonic acid and 1,3-propanedisulfonic acid. , 1,1-
Examples thereof include propanedisulfonic acid and 2,2-propanedisulfonic acid. Further, the polysulfonic acid as described above may have a substituent such as a hydrocarbon group, an alkoxy group, a halogen, a hydroxyl group, a nitro group, a cyano group and an amino group.

When polysulfonic acid as a dopant is used in excess of polyaniline, the strength of a conductive polyaniline film obtained by cast coating of the obtained solution may be low. Therefore, when preparing a polyaniline solution, the amount of polysulfonic acid added to polyaniline is preferably equal to or less than the amino group of the main chain of polyaniline, preferably 0.75 or less, particularly preferably Is 0.5 equivalent or less.

Conductive polyaniline thus obtained
The conductivity of the membrane is usually 10^-6S / cm or more, many places
10^-FourS / cm or more, but according to a preferred embodiment
For example, 10 ^-2S / cm or more can be obtained. this
The conductive thin film is tough and can be bent easily
It won't break. In general, polyanines obtained by oxidative polymerization
Phosphorus is doped with the protic acid used during polymerization.
Therefore, it has conductivity. However, such conductive poly
Aniline is a weakly acidic, neutral or alkaline aqueous solution.
Or, in a basic organic solvent, as a dopant
Release protic acid, which significantly reduces its electrical conductivity.
It is known. Furthermore, conventionally, in general, a dopant
Protonic acid used as is hydrochloric acid, sulfuric acid, perchloric acid
Since it is a low-molecular acid such as
From the polyaniline thin film, which has
It is easy to diffuse and the surrounding metal parts where it is used are
May be corroded.

However, the conductive polyaniline film using polysulfonic acid as a dopant in the present invention is difficult to release the dopant in a weakly acidic, neutral or alkaline aqueous solution or a basic organic solvent, and thus the dielectric In various processes of forming a film on the top, even if it is washed with water or an organic solvent, the conductivity does not change, and not only a conductive film can be advantageously formed, but also the surrounding environment such as humidity and moisture. The excellent conductivity can be maintained irrespective of the change in the condition of, so that the capacitor characteristics are not impaired. Further, since polyaniline is not released from polyaniline, there is no possibility of corroding the metal part around which it is used.

According to the present invention, a film-forming metal having a roughened surface is subjected to electrolytic oxidation or air oxidation to form an oxide of the metal to form a dielectric film, and then as the above-mentioned dopant. By casting or coating a solution of an organic solvent-soluble polyaniline containing a polysulfonic acid, on the dielectric film, and drying,
The conductive film can be easily formed, and thus the solid electrolytic capacitor can be obtained.

Generally, aluminum or tantalum is preferably used as the film forming metal, and accordingly, a film of aluminum oxide or tantalum oxide is preferably used as the dielectric film. In general, the dielectric, as described above, usually consists of a film of aluminum oxide or tantalum oxide, which is usually rough and porous in order to increase the surface area. The solid electrolyte needs to adhere to the porous rough surface of the oxide film. According to the present invention, the solvent-soluble polyaniline can be formed into a film together with polysulfonic acid by casting or coating, so that the thickness of the film on the dielectric can be arbitrarily adjusted. For example, a dielectric layer with a thickness of 0.0
Films with various thicknesses ranging from 1 to 200 μm can be obtained, and accordingly, the conductivity of the conductive film is 10 ⁻⁶ to 10 ² S / cm.
It is also possible to adjust to the range of, preferably 10 ^{-2 to} 50 S / cm.

Moreover, according to the solid electrolytic capacitor of the present invention, the conductivity of the conductive polymer is due to electron conduction, so that the impedance is smaller in the high frequency region and the capacitance is smaller than that of the ion conductive electrolytic solution type capacitor. Is big. The shape of the electrolytic capacitor may be any of sheet type, laminated type, wound type and the like. When a large capacity is required, a laminated type or a wound type is preferably used. In the case of the winding type, according to the present invention, a method of forming a polyaniline film on the dielectric film and then winding the film, or an etching metal foil having the dielectric film formed thereon via a separator. It can be manufactured by, for example, a method of forming a polyaniline film on the dielectric film by winding it, injecting a polyaniline solution between the foils, and then heating and drying. Since the electrolytic capacitor according to the present invention does not contain an electrolytic solution, it is easy to make a chip.

[0066]

As described above, according to the solid electrolytic capacitor of the present invention, the conductive polymer film made of polyaniline having conductivity due to electron conduction is formed on the dielectric film, and it is used in the high frequency region. The impedance is small and the capacity is large. Further, according to the solid electrolytic capacitor of the present invention, as the solid electrolyte, conductive polyaniline having polysulfonic acid as a dopant is used, and the conductive polyaniline has remarkably excellent water resistance. Therefore, the obtained solid electrolytic capacitor has excellent durability and reliability.

Further, according to the present invention, a conductive film having excellent adhesion can be easily formed only by casting a solution containing polyaniline and polysulfonic acid on the dielectric oxide film and drying it. Therefore, it is easy to manufacture, and the manufacturing cost is significantly reduced. Further, since the electrolytic capacitor according to the present invention does not contain an electrolytic solution, it can be easily made into a chip and can be suitably used for surface mounting.

[0068]

EXAMPLES The present invention will be described below with reference to examples, together with reference examples for showing the production of organic solvent-soluble polyaniline used in the present invention. However, the present invention is not limited to these examples. Absent. Reference Example 1 (Production of Doped Conductive Organic Polymer by Oxidative Polymerization of Aniline) Distilled water 6 in a 10-liter separable flask equipped with a stirrer, a thermometer and a straight pipe adapter.
000g, 360% hydrochloric acid 360ml and aniline 400g
(4.295 mol) was charged in this order to dissolve the aniline. Separately, while cooling with ice water, 434 g (4.295 mol) of 97% concentrated sulfuric acid was added to 1493 g of distilled water in a beaker and mixed to prepare an aqueous sulfuric acid solution. This sulfuric acid aqueous 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 oxidant solution. The whole flask was cooled in a low temperature constant temperature bath, while keeping the temperature of the reaction mixture at -3 ° C or lower, while stirring, to an acidic aqueous solution of aniline salt, using a tubing pump, from the straight pipe adapter to the ammonium peroxodisulfate. 1 ml of aqueous solution
The mixture was gradually added at a rate of not more than / minute. At first, the colorless and transparent solution changes from greenish blue to blackish green as the polymerization proceeds.
Then, a black-green powder was deposited.

An increase in temperature is observed in the reaction mixture during this powder precipitation, but in this case too, according to the invention,
In order to obtain a high molecular weight polymer, the temperature in the reaction system is 0 ° C.
It is important to keep the temperature below -3 ° C. After the powder is deposited, the dropping rate of the aqueous solution of ammonium peroxodisulfate may be slightly increased, for example, about 8 ml / min. However, also in this case, it is necessary to monitor the temperature of the reaction mixture and adjust the dropping rate so as to keep the temperature at −3 ° C. or lower. Thus, after the dropping of the aqueous ammonium peroxodisulfate solution was completed over 7 hours, the stirring was continued for another 1 hour at a temperature of -3 ° C or lower.

The obtained polymer powder was filtered, washed with water, washed with acetone, and vacuum dried at room temperature to obtain 430 g of a black-green polymer powder. This was pressure-molded on a disk having a diameter of 13 mm and a thickness of 700 μm, and its electric conductivity was measured by the Juan der Pauw method, and it was found to be 14 S / cm. (Dedoping of conductive organic polymer with ammonia)
350 g of the above-mentioned doped conductive organic polymer powder was added to 4 liters of 2N ammonia water, and the mixture was stirred with an auto homomixer at a rotation speed of 5000 rpm for 5 hours. The mixture changed from black green to blue purple.

The powder was filtered off with a Buchner funnel, washed repeatedly with distilled water while stirring in a beaker until the filtrate became neutral, and then washed with acetone until the filtrate became colorless. did. Then, the powder was vacuum dried at room temperature for 10 hours to obtain a dark brown dedoped polymer powder 2
80 g was obtained. This polymer was soluble in N-methyl-2-pyrrolidone and had a solubility of 8 g (7.4%) in 100 g of the solvent. Also, using this as a solvent, 30
The intrinsic viscosity [η] measured at ° C was 1.23.

This polymer had a solubility of 1% or less in dimethyl sulfoxide and dimethylformamide.
Tetrahydrofuran, pyridine, 80% acetic acid aqueous solution, 6
It was practically insoluble in 0% formic acid aqueous solution and acetonitrile. For the sample obtained by molding the powder of polyaniline in the undoped state into a disk shape, the excitation wavelength was 457.9n.
The laser Raman spectrum obtained by irradiation with m is shown in FIG. For comparison, Y. Furukawa et al., Synth.Me
FIG. 2 shows the laser Raman spectrum obtained by irradiating the polyaniline in the undoped state shown in T., 16 , 189 (1986) at an excitation wavelength of 457.9 nm. This polyaniline was obtained by electrolytic oxidative polymerization of aniline on a platinum electrode.

FIG. 3 shows the result of measuring the Raman spectrum in the range of 1400 to 1700 cm ⁻¹ by changing the wavelength of the laser excitation light. Excitation wavelength is 48
As the wavelength is changed from 8.0 nm to 476.5 nm to 457.9 nm on the short wavelength side, Ia / Ib changes to 45
At 7.9 nm, it is 1.0 or more, indicating that the Ia / Ib intensity is reversed as compared with the case of 488.0 nm.

Further, FIG. 4 shows an electronic spectrum. Next, regarding the organic solvent-soluble polyaniline, GP using a GPC column for N-methyl-2-pyrrolidone was used.
C measurement was performed. As the column, three types of columns for N-methyl-2-pyrrolidone were connected and used. In addition, the eluent is 0.01 mol / l concentration of lithium bromide N-methyl-2.
A pyrrolidone solution was used. FIG. 5 shows the result of GPC measurement.

From these results, the organic solvent-soluble polyaniline had a number average molecular weight of 23,000 and a weight average molecular weight of 1
It was 60000 (both converted to polystyrene).
Similarly, various reaction conditions were changed to obtain organic solvent-soluble polyaniline having different intrinsic viscosities [η] measured at 30 ° C. in N-methyl-2-pyrrolidone. About these,
Table 1 shows the intrinsic viscosity [η] and the number average molecular weight and weight average molecular weight by GPC.

[0077]

[Table 1]

Reference Example 2 (Preparation of self-supporting film using soluble aniline oxidized polymer) 5 g of the dedoped aniline oxidized polymer powder obtained in Reference Example 1 was added little by little to 95 g of N-methyl-2-pyrrolidone. The solution was dissolved at room temperature to obtain a black blue solution.
When this solution was vacuum filtered with a G3 glass filter, the amount of insoluble matter remaining on the filter was extremely small. The filter was washed with acetone, and the remaining insoluble matter was dried and weighed to find that it was 75 mg.
Therefore, 98.5% of the polymer is dissolved and the insoluble matter is 1.
It was 5%.

The polymer solution thus obtained was cast on a glass plate, and after squeezing with a glass rod,
N-methyl-2-pyrrolidone was evaporated in a hot air circulation dryer. After that, the polymer film was naturally peeled from the glass plate by immersing the glass plate in cold water, thus obtaining a polymer film having a thickness of 40 μm.
The film was washed with acetone and then air-dried at room temperature to obtain a film having a copper-colored metallic luster.

The film has different strength and solubility depending on its drying temperature. When the drying temperature is 100 ° C. or lower, the obtained film dissolves in a small amount in N-methyl-2-pyrrolidone and has relatively low strength. But,
The film obtained by heating at a temperature of 130 ° C. or higher is extremely tough and does not dissolve in N-methyl-2-pyrrolidone or other organic solvents. It also does not dissolve in concentrated sulfuric acid. Thus, when heated at a high temperature, it is considered that the polymer molecules crosslink with each other in the process and become insoluble.

The undoped film thus obtained had an electric conductivity of the order of 10 ^-11 S / cm. The film did not break even after being bent 10,000 times, and had a tensile strength of 850 kg / cm ² . Reference Example 3 (Doping of Self-supporting Film with Protonic Acid) In Reference Example 2, the self-supporting film obtained by heating and drying at 160 ° C. for 2 hours was placed in a 1N sulfuric acid, perchloric acid and hydrochloric acid aqueous solution at room temperature to 66%. After soaking for a time, it was washed with acetone and air-dried to obtain a conductive film.

The films all showed a deep blue color and had electric conductivities of 9 S / cm, 13 S / cm and 6 S / cm, respectively. The tensile strength of the film doped with perchloric acid was 520 kg / cm ² . Reference Example 4 (Spectra and Structure of Soluble Polymer and Insoluble Film-Formed Polymer both in the undoped state) of the soluble polymer powder obtained in Reference Example 1 and the insoluble polymer film obtained in Reference Example 2 FT-IR spectra obtained by the KBr tablet method are shown in FIGS. 6 and 7, respectively. In the spectrum of the insoluble polymer film obtained in Reference Example 2, some absorption at 1660 cm ^-1 , which is considered to be due to the remaining solvent N-methyl-2-pyrrolidone, is slightly observed, but since the two spectra are almost the same, It is recognized that, by heating and drying the solvent after casting the solvent-soluble polymer, the polymer becomes insoluble in the solvent due to crosslinking, but a large change in the chemical structure does not occur.

Next, regarding the soluble polymer and the insoluble polymer,
The results of elemental analysis are shown below. Soluble polymer C, 77.19; H, 4.76; N, 14.86 (96.81 total)Insoluble polymer C, 78.34; H, 4.99; N, 15.16 (total 98.49) Based on this elemental analysis, the solubility standardized to C1 2.00
The composition formula of the volatile polymer is C_12.00H_8.82N_1.98And is insoluble
The composition formula of the polymer is C_12.00H_9.11N_1.99Is. On the other hand,
Similarly, a quinonediimine structure standardized to C12.00
The position and the phenylenediamine structural unit are respectively
It is as follows.Quinonediimine structural unit C₁₂H₈N₂ Phenylenediamine structural unit C₁₂H_TenN₂ Therefore, both the soluble polymer and the solvent-insoluble polymer are described above.
As you can see, quinone diimine structural unit and phenylenedia
A polymer having a min structural unit as a main repeating unit.
is there. Reference Example 5 The polymer film obtained in Reference Example 2 had various pKa values.
Immersion in an aqueous solution of protic acid or alcohol solution
Then, the possibility of doping was examined. Have different pKa values
Polymer film obtained by doping with protic acid
Table 2 shows the electric conductivity of the. Prototype with pKa value of 4.8 or less
Acid has been shown to be effective in polymer doping.
It

[0084]

[Table 2]

Example 1 7.5 g of the dedoped organic solvent-soluble polyaniline powder obtained in Reference Example 1 was added little by little to 42.5 g of N-methyl-2-pyrrolidone and dissolved to obtain a black blue solution. Got Further, 1.25 g of phenylhydrazine was added to this solution to reduce polyaniline. The solution turned brown.

1,5-naphthalenedisulfonic acid tetrahydrate 7.
A solution of 45 g dissolved in 42.55 g of N-methyl-2-pyrrolidone was prepared and mixed with the above polyaniline solution,
A green polyaniline solution containing the dopant was obtained.
This solution was cast on a glass plate and dried at 150 ° C. for 2 hours to obtain a polyaniline film. When this film was peeled from the glass plate, the thickness was 29 μm.
m, and the electrical conductivity was 0.3 S / cm. Table 3 shows the change in electric conductivity when the film was immersed in distilled water.

Next, the above-mentioned solution was applied onto the alumina dielectric film and heated and dried at 120 ° C. for 50 minutes to form a polyaniline film. Further, silver was vapor-deposited on it in an area of 10 mm × 13 mm to prepare a solid electrolytic capacitor. Table 4 shows the results of measuring the frequency characteristics of the capacitance and impedance of this capacitor. Example 2 7.5 g of the dedoped organic solvent-soluble polyaniline powder obtained in Reference Example 1 was added little by little to 42.5 g of N-methyl-2-pyrrolidone and dissolved to obtain a black blue solution. ..

To this solution was further added 1.25 phenylhydrazine.
g was added to reduce polyaniline. The solution turned brown. A solution of 4.93 g of m-benzenedisulfonic acid dissolved in 4.07 g of N-methyl-2-pyrrolidone was prepared and mixed with the above polyaniline solution to obtain a green polyaniline solution containing a dopant.

This solution was cast on a glass plate and dried at 150 ° C. for 2 hours to obtain a polyaniline film. When this film was peeled from the glass plate, it had a thickness of 19 μm and an electric conductivity of 1.6 S / cm. Table 3 shows the change in electric conductivity when the film was immersed in distilled water. Next, the above-mentioned solution was applied onto the alumina dielectric film and heated and dried at 120 ° C. for 50 minutes to form a polyaniline film. Further, silver was vapor-deposited on it in an area of 10 mm × 13 mm to prepare a solid electrolytic capacitor.

Table 4 shows the results of measuring the frequency characteristics of the capacitance and impedance of this capacitor. Example 3 7.5 g of the dedoped organic solvent-soluble polyaniline powder obtained in Reference Example 1 was added little by little to 42.5 g of N-methyl-2-pyrrolidone and dissolved to obtain a black-blue solution. ..

To this solution was further added 1.25 phenylhydrazine.
g was added to reduce polyaniline. The solution turned brown. A solution of 3.85 g of 1,2-ethanedisulfonic acid dissolved in 46.15 g of N-methyl-2-pyrrolidone was prepared and mixed with the above polyaniline solution to obtain a green polyaniline solution containing a dopant.

This solution was cast on a glass plate and dried at 150 ° C. for 2 hours to obtain a polyaniline film. When this film was peeled from the glass plate, it had a thickness of 30 μm and an electrical conductivity of 4.3 S / cm. Table 3 shows the change in electric conductivity when the film was immersed in distilled water. Next, the above-mentioned solution was applied onto the alumina dielectric film and heated and dried at 120 ° C. for 50 minutes to form a polyaniline film. Further, silver was vapor-deposited on the surface of an area of 10 mm × 13 mm to prepare a solid electrolytic capacitor.

Table 4 shows the results of measuring the frequency characteristics of the capacitance and impedance of this capacitor.

[0094]

[Table 3]

[0095]

[Table 4]

Comparative Example 1 7.5 g of the dedoped organic solvent-soluble polyaniline powder obtained in Reference Example 1 was added little by little to 42.5 g of N-methyl-2-pyrrolidone and dissolved to obtain a black blue solution. Got Further, 1.25 g of phenylhydrazine was added to this solution to reduce polyaniline. The solution turned brown.

7.88 g of p-toluenesulfonic acid monohydrate
Was dissolved in 42.12 g of N-methyl-2-pyrrolidone and mixed with the above polyaniline solution to obtain a green polyaniline solution containing a dopant. This solution was cast on a glass plate and dried at 150 ° C. for 2 hours to obtain a polyaniline film. When this film was peeled from the glass plate, it had a thickness of 25 μm and an electric conductivity of 0.4 S / cm. Table 3 shows the change in electric conductivity when the film was immersed in distilled water.

Next, the above-mentioned solution was applied onto the alumina dielectric film and heated and dried at 120 ° C. for 30 minutes to form a polyaniline film. Further, silver was vapor-deposited on it in an area of 10 mm × 13 mm to prepare a solid electrolytic capacitor. Table 4 shows the results of measuring the frequency characteristics of the capacitance and impedance of this capacitor.

[Brief description of drawings]

FIG. 1 is a laser Raman spectrum obtained by exciting an organic solvent-soluble aniline oxidized polymer in a dedoped state used for manufacturing a solid electrolytic capacitor according to the present invention with light having a wavelength of 457.9 nm;

FIG. 2 shows a conventional polyaniline 45.
Laser Raman spectrum when excited with light of 7.9 nm wavelength,

FIG. 3 is a laser Raman spectrum obtained by exciting the same solvent-soluble polyaniline as in FIG. 1 with light having different excitation wavelengths,

FIG. 4 shows N of an aniline oxidation polymer soluble in an organic solvent.
-Methyl-2-pyrrolidone solution electronic spectrum,

FIG. 5 is a graph showing the molecular weight distribution of solvent-soluble polyaniline by GPC,

FIG. 6 shows K of a solvent-soluble polyaniline oxidation polymer.
FT-IR spectrum by Br tablet method,

FIG. 7 is an FT- by a KBr tablet method of a solvent-insoluble film obtained by casting a solvent-soluble polymer.
It is an IR spectrum.

Claims (4)

[Claims] 1. A dielectric oxide film formed on a film-forming metal, and a solid electrolyte on the dielectric oxide film of the general formula: (In the formula, m and n each represent a mole fraction of the quinonediimine structural unit and the phenylenediamine structural unit in the repeating unit, and 0 <m <1, 0 <n <1, and m + n = 1). A polyaniline having a repeating unit, which is soluble in an organic solvent in a dedoped state, and has a skeleton vibration of para-substituted benzene in a laser Raman spectrum obtained by excitation with light having a wavelength of 457.9 nm, 1600 cm ^-1 To the organic solvent-soluble polyaniline having a ratio Ia / Ib of the Raman line intensity Ia of the skeletal stretching vibration appearing at a higher wave number and the Raman line intensity Ib of the skeletal stretching vibration appearing at a lower wave number than 1600 cm ⁻¹ is 1.0 or more. , A conductive polymer film formed by doping a polysulfonic acid having two or more sulfonic acid groups in the molecule is formed. Solid electrolytic capacitor to be. 2. The solid electrolytic capacitor according to claim 1, wherein the polyaniline has an intrinsic viscosity [η] measured at 30 ° C. in N-methyl-2-pyrrolidone of 0.40 dl / g or more. 3. A method for producing a solid electrolytic capacitor comprising a dielectric oxide film formed on a film-forming metal and a conductive polymer film made of polyaniline as a solid electrolyte on the dielectric oxide film. , The general formula: (In the formula, m and n each represent a mole fraction of the quinonediimine structural unit and the phenylenediamine structural unit in the repeating unit, and 0 <m <1, 0 <n <1, and m + n = 1). A polyaniline having a repeating unit, which is soluble in an organic solvent in a dedoped state, and has a skeleton vibration of para-substituted benzene in a laser Raman spectrum obtained by excitation with light having a wavelength of 457.9 nm, 1600 cm ^-1 A polyaniline having a ratio Ia / Ib of the Raman line intensity Ia of the skeletal stretching vibration appearing at a higher wave number than 1600 cm ⁻¹ and the Raman line intensity Ib of the skeletal stretching vibration appearing at a lower wave number than 1600 cm ⁻¹ is 1.0 or more in the molecule. A poly (sulfonic acid) having two or more sulfonic acid groups is dissolved in an organic solvent, and the resulting solution is applied on a dielectric film and dried to form a dielectric film. Method for producing a solid electrolytic capacitor, which comprises forming a film of conductive polyaniline on film. 4. The production of a solid electrolytic capacitor according to claim 3, wherein the polyaniline has an intrinsic viscosity [η] measured at 30 ° C. in N-methyl-2-pyrrolidone of 0.40 dl / g or more. Method.