Patent Description:
A capacitor is a kind of electronic component used in various electronics such as personal computers and mobile phones and, basically, has a structure in which a dielectric is held between two opposing electrode plates. When a DC voltage is applied to the plates, electric charges are stored in each electrode by the polarization action of the dielectric. There are many types of capacitors and, for example, an aluminum electrolytic capacitor, a multilayer ceramic capacitor, a tantalum electrolytic capacitor, a film capacitor, and the like are known. In recent years, as electronics has become smaller, lighter, and more functional, small and high capacity capacitors are demanded, and many studies are conducted to improve performance of capacitors.

Many prior arts have reported using a conductive polymer as a conductive material that can be used for a capacitor electrode. The conductive polymer has a conjugated structure and is composed of a combination of a main skeleton enabling electron transfer and a dopant for giving electron or hole carriers to the main skeleton in the expanded conjugate. As the conductive main skeleton, a skeleton having a chemical structure with a developed n-electron conjugated system, such as a polymer including <NUM>,<NUM>-ethylenedioxythiophene (EDOT), pyrrole, aniline, and the like, is generally used. Various dopants, such as an inorganic Lewis acid and an organic proton acid, correspond to it. Of these, a sulfonic acid compound as an organic protonic acid is generally used.

For example, Patent Literature <NUM> has reported a method for manufacturing an electrolytic capacitor by impregnating a PEDOT / PSS aqueous dispersion into a porous metal element. In Patent Literature <NUM>, the PEDOT / PSS, having a particle diameter of about several tens of nanometers, was prepared by polymerizing EDOT with using polystyrene sulfonic acid (PSS) as a dispersant and a dopant.

Patent literature <NUM> discloses a conductive polymer capable of adjusting an ionization potential by using a conductive polymer obtained by polymerizing various EDOT derivatives with using PSS as a dopant.

Further conductive polymers are described in Patent literatures <NUM>, <NUM> and <NUM>.

In the method described in Patent Literature <NUM>, since the conductive polymer could not sufficiently fill the inside of the porous material, the capacitance appearance rate of the conductive polymer solid electrolytic capacitor was insufficient.

The present invention has been made in view of such circumstances, and an object thereof is to provide a method for manufacturing a conductive polymer solid electrolytic capacitor having an excellent capacitance appearance rate, and a conductive polymer suitable for the method for manufacturing.

According to the present invention, a method for manufacturing a conductive polymer solid electrolytic capacitor is provided that comprises:.

The inventors have found that, by using the method for manufacturing a conductive polymer solid electrolytic capacitor described above, pores of a porous material can be easily impregnated with a dispersion including a conductive polymer, and as a result, a conductive polymer solid capacitor with an excellent capacitance appearance rate can be produced and have completed the present invention.

As shown in <FIG>, the conductive polymer solid electrolytic capacitor <NUM>, obtained by the method for manufacturing the conductive polymer solid electrolytic capacitor of the present invention has an electrode material which forms a porous material and works as a anode <NUM>, an oxide thin film which is obtained by oxidation treatment on the surface of the porous material and works as a dielectric <NUM>, and a conductive polymer which fills the pores of the porous material and works as a cathode <NUM>.

In the present application, a capacitance appearance rate is shown by the following formula. The capacitance appearance rate is a ratio of an actual capacitance (<NUM>), measured after introducing a solid electrolyte into pores of a porous material, to a capacitance (<NUM>), measured with pores of a porous material filled with an electrolyte (sulfuric acid, phosphoric acid, and the like. <MAT> Thus, a high capacitance appearance rate indicates that the pores of the porous material are filled with sufficient quantity of the solid electrolyte (the conductive polymer in the present invention), and that the resulting solid electrolytic capacitor exerts sufficiently its electrode capacitance.

The following are various examples of the present invention. The following embodiments can be combined with each other.

Preferably, an average pore diameter of the porous material is <NUM> or more and <NUM> or less.

Preferably, the electrode material includes tantalum, niobium or an alloy thereof.

Preferably, the dopant includes at least one atom selected from the group consisting of oxygen, fluorine, and nitrogen.

According to another aspect of the present disclosure, a dispersion including a conductive polymer dispersed in a non-aqueous solvent is provided, wherein the conductive polymer comprises at least one of the structural units represented by the following formula (<NUM>) and the following formula (<NUM>)
<CHM>
wherein:.

The embodiments of the present invention will be described in detail as below.

The method for manufacturing the conductive polymer solid electrolytic capacitor according to the present invention comprising a conductive polymer introduction step and a solvent removal step. From the viewpoint of sufficiently filling the pores of the porous material with the conductive polymer, each of these steps is preferably performed a plurality of times, such as <NUM> times or more, <NUM> times or more, <NUM> times or more.

By including at least one of the structural units represented by formula (<NUM>) and formula (<NUM>), the conductive polymer used in the present invention has a main skeleton, which has a developed n-conjugated system and is suitable for the conductive polymer.

R<NUM> in the formula (<NUM>) and the formula (<NUM>) is an alkyl group having <NUM> to <NUM> carbon atoms, an alkoxy group having <NUM> to <NUM> carbon atoms, an alkylene oxide group having <NUM> to <NUM> carbon atoms and having <NUM> to <NUM> repeating units, a phenyl group optionally having any substituent at any position, heterocyclic group optionally having any substituent at any position, or condensed ring group optionally having any substituent at any position. From the viewpoint of conductivity, an alkyl group and a phenyl group are preferable, and among them, a phenyl group having substituents at <NUM>,<NUM>- positions can be more preferably used.

An arbitrary substituent, which the phenyl group, the heterocyclic group, or the condensed ring group has, includes, for example, an alkyl group having <NUM> to <NUM> carbon atoms, an alkoxy group having <NUM> to <NUM> carbon atoms, an alkylene oxide group having <NUM> to <NUM> carbon atoms and having <NUM> to <NUM> repeating units, a phenyl group, a naphthyl group, a hydroxy group, a halogen such as a fluorine, a chlorine, a bromine and an iodine, an aldehyde group, an amino group, a cycloalkyl group having <NUM> to <NUM> carbons, and the like.

As the heterocyclic group for example, silole ring, furan ring, thiophene ring, oxazole ring, pyrrole ring, pyridine ring, pyridazine ring, pyrimidine ring, pyrazine ring, triazine ring, oxadiazole ring, triazole ring, imidazole ring, pyrazole. ring, thiazole ring, indole ring, benzimidazole ring, benzthiazole ring, benzoxazole ring, quinoxaline ring, quinazoline ring, phthalazine ring, thienothiophene ring, carbazole ring, azacarbazole ring (which represents that any one or more of the carbon atoms constituting the carbazole ring is replaced by a nitrogen atom), dibenzosilole ring, dibenzofuran ring, dibenzothiophene ring, benzothiophene ring, ring in which any one or more of carbon atoms constituting dibenzofuran ring is replaced by nitrogen atom, benzodifuran ring, benzodithiophene ring, acridine ring, benzoquinoline ring , phenazine ring, phenanthridine ring, phenanthroline ring, cyclazine ring, kindrin ring, tepenidine ring, quinindrine ring, triphenodithiazine ring, triphenodioxazine ring, phenanthrazine ring, anthrazine ring, perimidine ring, naphthofuran ring, naphtho thiophene ring, naphthodifuran ring, naphthodithiophene ring, anthrafuran ring, anthradifuran ring, anthrathiophene ring, anthradithiophene ring, thianthrene ring, phenoxathiin ring, dibenzocarbazole ring, indolocarbazole ring, dithienobenzene ring, epoxy ring, aziridine ring, thiirane ring, oxetane ring, azetidine ring, thietane ring, tetrahydrofuran ring, dioxolane ring, pyrrolidine ring, pyrazolidine ring, imidazolidine ring, oxazolidine ring, tetrahydrothiophene ring, sulfolane ring, thiazolidine ring, ε-caprolactone ring, ε-caprolactam ring, piperidine ring, hexahydropyridazine ring, hexahydropyrimidine ring, piperazine ring, morpholine ring, tetrahydropyran ring, <NUM>,<NUM>-dioxane ring, <NUM>,<NUM>- dioxane ring, trioxane ring, tetrahydrothiopyran ring, thiomorpholine ring, thiomorpholine-<NUM>,<NUM>-dioxide ring, pyranose ring, diazabicyclo [<NUM>,<NUM>,<NUM>] -octane ring, phenoxazine ring, phenothiazi ring, okisantoren ring, thioxanthene ring, monovalent group derived from phenoxathiin ring can be mentioned.

As the condensed ring for example, naphthalene ring, azulene ring, anthracene ring, phenanthrene ring, pyrene ring, chrysene ring, naphthacene ring, triphenylene ring, acenaphthene ring, coronene ring, fluorene ring, fluoranthrene ring, pentacene ring, perylene ring, pentaphen ring, picene ring, pyranthrene ring, and the like can be mentioned.

As an arbitrary substituent, for example, an alkyl group having <NUM> to <NUM> carbon atoms, an alkoxy group having <NUM> to <NUM> carbon atoms, an alkylene oxide group having <NUM> to <NUM> carbon atoms and having <NUM> to <NUM> repeating units, a phenyl group, a naphthyl group, a hydroxy group, a halogen such as a fluorine, a chlorine, a bromine, a iodine, an aldehyde group, an amino group, a cycloalkyl group having <NUM> to <NUM> carbon atoms can be mentioned.

The dopant is not particularly limited, but preferably includes at least one atom selected from the group consisting of oxygen, fluorine, and nitrogen, and more preferably at least one selected from the group consisting of a sulfonic acid derivative, a boronic acid derivative, a carboxylic acid derivative, and a phosphoric acid derivative.

As the dopant, for example, polyanion such as polystyrene sulfonic acid, poly-<NUM>-sulfoethyl (meth) acrylate, poly-<NUM>-propylsulfo (meth) acrylate and copolymers thereof, or alkali metal salt thereof, and monoanion such as p-toluene sulfonic acid, dodecyl sulfonic acid, dodecylbenzene sulfonic acid, di (<NUM>-ethylhexyl)sulfosuccinic acid, polyoxyethylene polycyclic phenyl ether sulfonate, polyoxyethylene aryl ether sulfate, tetrafluoroboric acid, trifluoro Acetic acid, hexafluorophosphoric acid, trifluoromethane sulfonimide, and the like, or alkali metal salt thereof can be mentioned.

From the viewpoint of improving dispersibility for a non-aqueous solvent and facilitating introduction into pores, a dopant having <NUM> or <NUM> anions in one dopant molecule is included, and preferably <NUM> anion in one dopant molecule is included, wherein <NUM> to <NUM> mass% of the dopant include a dopant having <NUM> or <NUM> anions in one dopant molecule.

One kind of dopant may be used alone, or two or more kinds may be used.

When two or more kinds of dopant are used, the content ratio of the dopant component having <NUM> or <NUM> anions in one dopant molecule is 80mass% to 100mass%, and may be within a range between.

The number of structural units (<NUM>) and (<NUM>) that the conductive polymer has is not particularly limited, is preferably <NUM> or more and <NUM> or less. Specifically, it may be, for example, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> or <NUM>, and within a range between any two of the numerical values exemplified here.

The conductivity of the conductive polymer is preferably <NUM>/cm or more and <NUM>/cm or less, for example, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>/cm or the like, and may be within a range between any two of the numerical values exemplified here.

The method for synthesizing the conductive polymer is not particularly limited. For example, the conductive polymer can be obtained by a condensation polymerization and / or an oxidative polymerization by adding a dopant and an oxidizing agent to <NUM>,<NUM>-ethylenedioxythiophene (EDOT) and aldehyde, followed by heating and stirring in a solvent under an inert gas atmosphere. Further, an oxidant as a decomposition accelerator may be added.

The oxidant is not particularly limited and may be any oxidant allowing the polymerization reactions to proceed. For example, ammonium peroxodisulfate, potassium peroxodisulfate, sodium peroxodisulfate, iron chloride (III), iron sulfate (III), iron hydroxide. (III), iron tetrafluoroborate (III), hexafluorophosphoric acid iron (III), copper sulfate (II), copper chloride (II), copper tetrafluoroborate (II), hexafluorophosphoric acid copper (II) ammonium oxodisulfate, organic peroxide, and the like can be mentioned.

The solvent is not particularly limited and may be any solvent in which condensation reaction of the heterocyclic compound and the aldehyde derivative proceeds. As a solvent, alcohol solvents such as Gamma butyrolactone, propylene carbonate, ethylene carbonate, acetonitrile, tert-butyl methyl ether, ethyl acetate, benzene, heptane, water, methanol, ethanol, isopropyl alcohol, butanol, and ketone solvent such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and glycol solvents such as methyl cellosolve, ethyl cellosolve, propylene glycol methyl ether, propylene glycol ethyl ether, and lactic acid solvents such as methyl lactate and ethyl lactate, and the like can be mentioned. In the synthesis of the conductive polymer, the same solvent as that used in the step of introducing conductive polymer may be used, a different solvent may be used, or a non-aqueous solvent may be used. The solvent used in the synthesis is preferably an aprotic solvent in view of efficiency of the oxidant.

The content ratio of the structural units (<NUM>) and (<NUM>) contained in the conductive polymer according to the present invention can be adjusted by the ratio of amount of EDOT and aldehyde added. The mole ratio of EDOT and aldehyde added, EDOT/aldehyde, is <NUM>/<NUM>, <NUM>/<NUM>, <NUM>/<NUM>, <NUM>/<NUM>, and <NUM>/<NUM>, for example, and may be within the range between any two of the numerical values. From the viewpoint of the balance between solubility and conductivity, a ratio of <NUM>/<NUM> to <NUM>/<NUM> is preferable, and a ratio of <NUM>/<NUM> to <NUM>/<NUM> is more preferable.

In the non-aqueous solvent according to the present invention, the conductive polymer is dispersed and the resulting dispersion is used to impregnate the porous material with.

The non-aqueous solvent is not particularly limited as long as the conductive polymer can be dispersed in it. As a non-aqueous solvent is alcohol solvents such as methanol, ethanol, isopropyl alcohol, butanol, ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, glycol solvents such as methyl cellosolve, ethyl cellosolve, propylene glycol methyl ether, propylene glycol ethyl ether, Lactic acid solvents such as methyl lactate and ethyl lactate, toluene, ethyl acetate, propylene carbonate, γ-butyrolactone, methyl ethyl ketone, toluene, isopropyl alcohol, ethylene glycol, dimethyl sulfoxide, methanol, benzyl alcohol and the like can be mentioned. Propylene carbonate, γ-butyrolactone, methyl ethyl ketone, toluene, isopropyl alcohol, ethylene glycol, dimethyl sulfoxide, methanol, benzyl alcohol and the like is particularly preferred. A plurality of solvents may be used in combination.

The dispersion includes the above conductive polymer dispersed in the non-aqueous solvent.

The non-volatile content excluding the solvent component from the dispersion is not particularly limited, but is, for example, <NUM>. 0mass% or more and <NUM>. 0mass% or less, specifically, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>. 0mass%, and the like, and may be within a range between any two of the numerical values exemplified here.

The conductive polymer in the dispersion has a volume average particle diameter D50 of <NUM> to <NUM>. The average particle diameter of the conductive polymer in the dispersion is preferably small from the viewpoint of easy introduction of the conductive polymer into the pores of the porous material. For example, D10 is <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and may be in the range between any two of these numerical values. D50 is <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and may be within the range between any two of these numbers. D90 is <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and may be within the range between any two of these numbers. D90/D10, which is the ratio of D90 and D10, is <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and the like, and may be within the range between any two of the numerical values exemplified here.

The porous material used in the present invention includes an electrode material that is a sintered body of particles and a dielectric that covers the surface of the electrode material.

The electrode material may include, for example, a material containing aluminum, tantalum, niobium or an alloy thereof. From the viewpoint of using a porous material having smaller pores, the electrode material preferably includes tantalum, niobium or an alloy thereof.

From the viewpoint of preventing weak bonding between the particles when sintered, the average particle diameter of the electrode material particles is preferably <NUM> or more, more preferably <NUM> or more. From the viewpoint of making the pores of the porous body smaller, <NUM> or less is preferable, and <NUM> or less is more preferable. The average particle diameter of the electrode material particles is, for example, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and the like, and may be within a range between any two of the numerical values.

A method for producing a sintered body of particles is not particularly limited, but includes a method in which the particles are once compressed to form a pellet and then heated and sintered. For example, a tantalum sintered element can be manufactured in accordance with the test condition of <NUM> kCV powder specified in Table <NUM> of the appendix of "Test method of tantalum sintered anodes for electrolytic capacitors" of Standard of Electronic Industries Association of Japan EIAJ RC-2361A.

The average pore diameter of the porous material is preferably <NUM> or more and <NUM> or less, more preferably <NUM> or more and <NUM> or less, for example, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and the like, and may be within the range between any two of the numerical values exemplified here.

A CV value (µF · V/g) is generally used as an index to evaluate the electrical characteristics of an electrode material for a capacitor.

Here, the charge capacity C per unit voltage that the capacitor can store is represented as: C = (ε · S) / t, S: electrode area (m<NUM>), t: distance between electrodes (m), ε: dielectric constant (F / m).

Thus, the charge capacity C increases as the electrode area S increases, the distance between electrodes t decreases, and the dielectric constant ε increases. Therefore, in order to increase the CV value, it is effective to increase the electrode area S, for example, by selecting a porous material as the electrode material or to reduce the distance between electrodes t, for example, by making the dielectric thinner.

The CV value of the electrode material is, for example, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> kCV/g, and the like, and may be within a range between any two of the numerical values exemplified here.

The thickness of the dielectric is preferably thin from the viewpoint of increasing the CV value, but is preferably not too thin from the viewpoint of preventing dielectric breakdown. The film thickness of the dielectric is, for example, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and the like, and may be in the range between any two of the numerical values exemplified here.

The dielectric used in the present invention is an oxide thin film obtained by oxidation treatment of the surface of the electrode material. The method of oxidizing the surface of the electrode material is not particularly limited. For example, the method of anodizing in an aqueous solution by applying a voltage can be mentioned.

As a method of impregnating the dispersion into the porous material, it is common to immerse the porous material in the dispersion and a method of increasing or decreasing the pressure, and applying vibration, ultrasonic waves, or heat can be mentioned for example.

The solvent removal step according to the present invention is to remove at least a part of the non-aqueous solvent and form the solid electrolyte that covers the surface of the porous material.

The method for removing the solvent is not particularly limited, and a drying method, a heating method, and a combination thereof can be mentioned. As the heating method, a method of holding in a heating chamber and a method of contacting with a hot plate can be mentioned. From the viewpoint of preventing the denaturation of the porous material, the heating temperature is preferably <NUM> or lower, more preferably <NUM> or lower. From the viewpoint of quickly removing the solvent, the heating temperature is preferably <NUM> or higher, more preferably <NUM> or higher.

<NUM> of propylene carbonate, <NUM> of <NUM>,<NUM>-ethylenedioxythiophene (EDOT), and <NUM> of PTS · H<NUM>O (p-toluene sulfonic acid monohydrate) were added to a <NUM> flask and stirred for <NUM>. Then, under nitrogen perge, <NUM> of Iron (III) tris(<NUM>-methylbenzenesulfonate) (Fe (PTS) <NUM>), <NUM> of <NUM>, <NUM>, <NUM>-trimethylbenzaldehyde, <NUM> of benzoyl peroxide (purity 75mass%, manufactured by Nihonyushi Corporation) were further added and the mixture was stirred at <NUM> for <NUM> hours. Then, <NUM> of Lewatit (registered trademark) MP62WS (manufactured by LANXESS) and <NUM> of Lewatit (registered trademark) monoplus S108H (manufactured by LANXESS), which were ion exchange resins, were added and the resulting mixture was stirred for <NUM> hours, and filtered. The obtained filtrate was treated with an ultrasonic homogenizer to obtain a propylene carbonate dispersion A of a conductive polymer with a non-volatile content of <NUM>.

A propylene carbonate dispersion B of a conductive polymer with a non-volatile content of <NUM>. 6mass% was obtained by the same procedure except that <NUM> of <NUM>,<NUM>,<NUM>-trimethylbenzaldehyde in Production Example <NUM> was changed to <NUM> of <NUM>,<NUM>- dichlorobenzaldehyde s.

A propylene carbonate dispersion C of a conductive polymer with a non-volatile content of <NUM>. 1mass% was obtained by the same procedure except that <NUM> of <NUM>,<NUM>,<NUM>-trimethylbenzaldehyde in production example <NUM> was changed to <NUM> of butylaldehyde.

A propylene carbonate dispersion D of a conductive polymer with a non-volatile content of <NUM>. 1mass% was obtained by the same procedure except that <NUM> of <NUM>,<NUM>,<NUM>-trimethylbenzaldehyde in Production Example <NUM> was changed to <NUM> of benzaldehyde.

<NUM> of acetonitrile and <NUM> of <NUM>,<NUM>-dichlorobenzaldehyde were added to a <NUM> flask. The mixture was heated to <NUM> after nitrogen purge was performed for <NUM>. Next, <NUM> of copper tetrafluoroborate hydrate was added and stirred until a homogeneous solution was obtained, then <NUM> of EDOT was added and stirred for <NUM> hour. Further, <NUM> of copper tetrafluoroborate hydrate was added and the resultant mixture was stirred for <NUM> hours. <NUM> of methanol was added to the flask to sufficiently precipitate solids, and then suction filtration was performed with ADVANTEC 4A filter paper (JIS P <NUM>), and the residue was washed with methanol until the filtrate became transparent. Thereafter, the residue was dried at <NUM> to obtain <NUM> of a conductive polymer powder E.

<NUM> of propylene carbonate was added to <NUM> of the conductive polymer E, and the mixture was stirred, and dispersed with an ultrasonic homogenizer to obtain a propylene carbonate dispersion E of a conductive polymer with a non-volatile content of <NUM>.

A propylene carbonate dispersion F of a conductive polymer with a non-volatile content of <NUM>. 3mass% was obtained by the same procedure except that PTS · H<NUM>O in Production Example <NUM> was changed to <NUM> of trifluoromethanesulfonimide.

A propylene carbonate dispersion G of a conductive polymer with a non-volatile content of <NUM>. 3mass% was obtained by the same procedure except that PTS · H<NUM>O in Production Example <NUM> was changed to <NUM> of trifluoroacetic acid.

A propylene carbonate dispersion H of a conductive polymer with a non-volatile content <NUM>. 3mass% was obtained by the same procedure except that PTS · H<NUM>O in Production Example <NUM> was changed to <NUM> of 55mass% aqueous solution of hexafluorophosphoric acid.

A propylene carbonate dispersion I of a conductive polymer with a non-volatile content of <NUM>. 5mass% was obtained by the same procedure except that PTS · H<NUM>O in Production Example <NUM> was changed to <NUM> of 18mass% aqueous solution of polystyrene sulfonic acid (PSS) (manufactured by Akzo Nobel) and <NUM> of PTS · H<NUM>O.

A γ- butyrolactone dispersion J of a conductive polymer with a non-volatile content of <NUM>. 5mass% was obtained in the same procedure except that propylene carbonate in Production Example <NUM> was changed to γ- butyrolactone (y-BL).

<NUM> of methyl ethyl ketone was added to <NUM> of the liquid A produced in Production Example <NUM> and the resultant mixture was stirred to obtain a dispersion K of a non-volatile content of <NUM>.

<NUM> of toluene was added to <NUM> of the liquid A produced in Production Example <NUM> and the resultant mixture was stirred to obtain a dispersion L with a non-volatile content of <NUM>.

<NUM> of isopropyl alcohol was added to <NUM> of the liquid A produced in Production Example <NUM> and the resultant mixture was stirred to obtain a dispersion M with a non-volatile content of <NUM>.

<NUM> of ethylene glycol was added to <NUM> of the liquid A produced in Production Example <NUM> and the resultant mixture was stirred to obtain a dispersion N with a non-volatile content of <NUM>.

Orgacon ICP1050 (PEDOT/PSS) manufactured by AGFA was treated with an ultrasonic homogenizer. Then, DMSO in an amount of 5wt% based on the total amount was added and the resultant mixture was stirred to obtain a dispersion O with a non-volatile content of <NUM>%.

<NUM> of sodium <NUM>-(methacryloyloxy)ethanesulfonate, <NUM> of <NUM>-hydroxyethyl methacrylate, <NUM> of <NUM>-ethylhexyl methacrylate, <NUM> of ion exchange water, <NUM> of isopropyl alcohol were added into a <NUM> four-necked flask with a stirrer, a nitrogen gas introducing pipe, a reflux cooler, an inlet and a thermometer. While nitrogen gas was introduced into the flask, the mixture in the flask was heated to <NUM>. Next, <NUM> of azobisisobutyronitrile was added into the flask, and polymerization reaction was performed at <NUM> for <NUM> hours to obtain a polymer solution. All the obtained polymer solution was transferred to a <NUM> beaker and <NUM> of isopropyl alcohol was added under stirring with a stirrer. Thereafter, when the stirring was stopped, a precipitate was obtained. After filtering it under reduced pressure, the residue was dried at <NUM> for <NUM> hours, and then pulverized in a mortar to obtain a high molecular compound powder.

<NUM> of the resulting high molecular compound powder, <NUM> of ion exchange water, and <NUM> of <NUM>% hydrochloric acid aqueous solution were added into a <NUM> four-necked flask with a stirrer, a nitrogen gas introducing pipe, a reflux cooler, an inlet and a thermometer. The mixture was heated to <NUM>, stirred for <NUM> hours, and then cooled to <NUM>. The solution in the flask was uniformly transparent. Then, <NUM> of <NUM>,<NUM>-ethylenedioxythiophene (EDOT) was added to the solution in the flask, and the resultant mixture was stirred to obtain a uniform emulsion, and then heated to <NUM>. Then, <NUM> of iron sulfate (III) n hydrate (<NUM>-<NUM>% in content as iron sulfate (III)) dissolved in <NUM> of ion exchange water was dropped in the flask kept at <NUM> over <NUM> hours. After finishing the dropping, the polymerization reaction was performed at <NUM> for <NUM> hours.

After completion of the polymerization reaction, the total amount of reaction liquid was transferred to an evaporator, and heated and distilled off under reduced pressure until the volume of a remaining amount of the reaction liquid became <NUM>. Thereafter, the reaction liquid was filtered under reduced pressure and the residue was transferred to a <NUM> beaker. The residue was washed with water by adding <NUM> of ion exchange water, stirring the mixture with a stirrer for <NUM> minutes, and filtering the mixture under reduced pressure again.

The same water wash step was further repeated <NUM> times, then the residue was transferred to a <NUM> beaker. <NUM> of n-hexane was added to the beaker and the mixture was stirred for <NUM> minutes, and filtered under reduced pressure. The residue was dried at <NUM> under reduced pressure for <NUM> hours to obtain a conductive polymer having a (meth) copolymer as a dopant. A dispersion P was obtained by adding <NUM> of the conductive polymer to a mixed solvent of <NUM> of methanol and <NUM> of benzyl alcohol, stirring and dispersing at room temperature.

Using a particle diameter distribution measuring device (Nanotrac UPA-UT151, Nikkiso Co. ), the volume average particle diameter, D10, D50, and D90 in the dispersions A to P were measured by the photodynamic scattering method. The results are shown in Tables <NUM>-<NUM>, <NUM>-<NUM>.

A certain amount of the dispersion A to P was measured on a tin dish and heated at <NUM> for <NUM> hours, and the weight of each residual amount was measured. The results are shown in Tables <NUM>-<NUM>, <NUM>-<NUM>.

Each of dispersion A to P was applied to a glass substrate in a size of <NUM> × <NUM>, and then dried at <NUM> to form a <NUM> thin film. Thereafter, the conductivity of each thin film was measured by using a resistivity meter (Loresta GP, manufactured by Mitsubishi Chemical Analytech). The results are shown in Tables <NUM>-<NUM>, <NUM>-<NUM>.

Potassium fluorotantalate was added to the diluted salt and the potassium fluorotantalate in the diluted salt was reacted with sodium to produce 100kCV tantalum powder. The tantalum powder was formed into a pellet having a density of <NUM>/cm<NUM> and the pellet was sintered at a temperature of <NUM> or higher in a degree of vacuum of <NUM>-<NUM> Pa to produce a sintered body. Thereafter, the pore diameter was measured by using a pore distribution measuring device (Micromeritec Autopore III <NUM>, manufactured by Shimadzu Corporation) by mercury intrusion porosimetry. The results are shown in Tables <NUM>-<NUM>, <NUM>-<NUM>. Detailed results of example <NUM> are shown in <FIG>. The pores of example <NUM> were distributed between <NUM> and <NUM>, and the average pore diameter was <NUM>.

The 100kCV tantalum powder was formed into a pellet having a density of <NUM>/cm<NUM> and the pellets was sintered at a temperature of <NUM> or higher in a degree of vacuum of <NUM>-<NUM> Pa to produce a sintered body. Thereafter, the sintered body was treated with 20V in a phosphoric acid electrolyte solution to form a dielectric oxide film, and a porous material including dielectric was obtained. The tantalum pellet was immersed in <NUM>% sulfuric acid, and the capacity was measured with an LCR meter (4263B, manufactured by Agilent).

The porous materials were immersed in the dispersions A to P to impregnate with the conductive polymer, and then dried at <NUM> for <NUM> minutes to remove the solvent. The steps of immersing in the dispersions A to P and drying were repeated <NUM> times, and then silver paste was applied to the porous materials to obtain conductive polymer solid electrolytic capacitors with silver coating of examples <NUM> to <NUM> and comparative examples <NUM> to <NUM>.

In addition, <NUM> of <NUM>,<NUM>-ethylenedioxythiophene (EDOT), <NUM> of PTS Fe··nH<NUM>O (P-toluene sulfonic acid iron hydrate) and <NUM> of butanol were mixed under cooling to <NUM> or lower. The porous material including dielectric was immersed in the solution and the porous material impregnated with the solution was reacted at <NUM> for <NUM> minutes, and at the same time, the solvent was removed. The steps of immersion and reaction were repeated <NUM> times, and then silver paste was applied to the porous material to obtain a conductive polymer solid electrolytic capacitor with a silver coating of comparative example <NUM>.

After connecting to the terminals of these conductive polymer solid electrolytic capacitors, the capacitance was measured with an LCR meter.

The capacitance appearance rate was calculated by the following formula. The results are shown in Tables <NUM>-<NUM>,<NUM>-<NUM>.

Claim 1:
A method for manufacturing a conductive polymer solid electrolytic capacitor comprising:
a conductive polymer introduction step; and
a solvent removal step,
wherein:
the conductive polymer introduction step comprises impregnating a porous material with a dispersion,
the dispersion includes a conductive polymer dispersed in a non-aqueous solvent,
the conductive polymer includes at least one of the structural units represented by the following formula (<NUM>) and the following formula (<NUM>),
<CHM>
in the formulas (<NUM>) and (<NUM>), R<NUM> is an alkyl group having <NUM> to <NUM> carbon atoms, an alkoxy group having <NUM> to <NUM> carbon atoms, an alkylene oxide group having <NUM> to <NUM> carbon atoms and having <NUM> to <NUM> repeating units, a phenyl group optionally having a substituent, a heterocyclic group optionally having a substituent, or a condensed ring group optionally having a substituent, A- is an anion derived from a dopant and n is <NUM> or more and <NUM> or less,
wherein <NUM> to <NUM> mass% of the dopant include a dopant having <NUM> or <NUM> anions in one dopant molecule;
the conductive polymer has a volume average particle diameter D50 of <NUM> to <NUM> in the dispersion, measured by a photodynamic scattering method;
the porous material includes an electrode material which is a sintered body of particles, and a dielectric covering a surface of the electrode material; and
the solvent removal step comprises removing at least a part of the non-aqueous solvent and forming a solid electrolyte which covers the surface of the porous material.