Conductive polymer composition and uses of same

Abstract

The present invention provides a conductive polymer composition with which it is possible to provide an electrolytic capacitor that is excellent in terms of low ESR characteristics. The conductive polymer composition contains: 0.01-10 mass% of a polythiophene (A) which contains at least one structural unit that is selected from the group consisting of a structural unit represented by general formula (1) and a structural unit represented by general formula (2); 0.001-10 mass% of a nanostructure material (B); 1-50 mass% of at least one substance (C) that is selected from the group consisting of polyglycerol and sugar alcohol; and a solvent.

Description

Conductive polymer composition and its uses

[0001] The present invention relates to a conductive polymer composition, a conductive polymer film obtained by drying the composition, and uses thereof.

[0002] 2. Description of the Related Art Conductive polymer capacitors, which are capacitors that use a conductive polymer as an electrolyte, are known as one type of electrolytic capacitor.

[0003] As a material for producing such conductive polymer capacitors, a conductive polymer composition containing a self-doped polythiophene conductive polymer and a carbon material has been reported (for example, Patent Document 1).

[0004] Japanese Patent Application Publication No. 2022-142739

[0005] It has become clear that electrolytic capacitors manufactured using conventionally known conductive polymer compositions have a problem in that the ESR characteristics are not sufficiently improved.

[0006] A conductive polymer composition comprising: 0.01 to 10 mass% of a polythiophene (A) containing at least one structural unit selected from the group consisting of a structural unit represented by the following general formula (1) and a structural unit represented by the following general formula (2); 0.001 to 10 mass% of a nanostructured material (B); 1 to 50 mass% of at least one member (C) selected from the group consisting of polyglycerin and sugar alcohol; and a solvent.

[0007] [In the above general formula (1), M ＋ represents a hydrogen ion. In the above general formulas (1) and (2), R represents an organic group having a total of 1 to 18 carbon atoms and having at least one substituent selected from the group consisting of a sulfonic acid group and a phosphonic acid group.]

[0008] According to one aspect of the present invention, an electrolytic capacitor exhibiting lower ESR characteristics can be provided.

[0009] An embodiment of the present invention will be described in detail below. In this specification, unless otherwise specified, the numerical range "A to B" means "A or more and B or less."

[0010] As electronic devices using electrolytic capacitors become faster and faster, there is a strong demand for electrolytic capacitors with long life, high capacitance, and low ESR characteristics.

[0011] Based on these requirements, the conductive polymer composition according to this embodiment can provide an electrolytic capacitor exhibiting excellent low ESR characteristics, which would not have been easily achieved by conventional techniques.

[0012] This embodiment has the remarkable effect of preventing the elution of the conductive polymer film in the electrolytic capacitor by providing a property not found in conventionally known conductive polymer compositions, which contributes to solving the problem of providing an electrolytic capacitor with excellent low ESR characteristics.

[0013] The present embodiment also relates to a method for producing a conductive polymer film, which includes a step of applying the conductive polymer composition to a substrate and drying the applied composition.

[0014] The present embodiment also relates to a method for producing an electrolytic capacitor, which includes a step of covering the surface of the dielectric oxide film of an anode body on which the dielectric oxide film has been formed with the conductive polymer composition, and then drying the resulting film by heating.

[0015] The present embodiment also relates to an electrolytic capacitor including an anode body coated with the conductive polymer composition, which is produced by the production method.

[0016] According to this embodiment, it is possible to provide a conductive polymer composition for producing an electrolytic capacitor that can maintain high capacitance and low ESR characteristics for a long period of time.

[0017] In this specification, the term "electrolytic capacitor" refers to a capacitor that includes a dielectric layer made of an oxide film of a metal (e.g., aluminum), and includes solid electrolytic capacitors and hybrid capacitors. In this specification, the term "solid electrolytic capacitor" refers to a capacitor whose electrolyte is solid. In addition, in this specification, the term "hybrid capacitor" refers to a capacitor whose electrolyte is a hybrid electrolyte that combines a conductive polymer and an electrolytic solution.

[0018] In this specification, a "solid electrolytic capacitor" may be referred to as a "solid electrolytic capacitor element," and a "hybrid capacitor" may be referred to as a "hybrid capacitor element."

[0019] The present embodiment is a conductive polymer composition comprising 0.01 to 10 mass % of a polythiophene (A) including at least one structural unit selected from the group consisting of a structural unit represented by the following general formula (1) and a structural unit represented by the following general formula (2), 0.001 to 10 mass % of a nanostructured material (B), 1 to 50 mass % of at least one member (C) selected from the group consisting of polyglycerin and sugar alcohol, and a solvent.

[0020] [In the above general formula (1), M ＋ represents a hydrogen ion. In the above general formulas (1) and (2), R represents an organic group having a total of 1 to 18 carbon atoms and having at least one substituent selected from the group consisting of a sulfonic acid group and a phosphonic acid group.]

[0021] In the above general formulas (1) and (2), R represents an organic group having a total of 1 to 18 carbon atoms and having at least one substituent selected from the group consisting of a sulfonic acid group and a phosphonic acid group.

[0022] The organic group having a total of 1 to 18 carbon atoms is not particularly limited, and examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, a hexyl group, an isohexyl group, a heptyl group, an octyl group, a 2-ethylhexyl group, a nonyl group, a decyl group, a methoxymethyl group, an ethoxymethyl group, a propoxymethyl group, an isopropoxymethyl group, a butoxymethyl group, an isobutoxymethyl group, a tert-butoxymethyl group, a hexyloxymethyl group, an isohexyloxymethyl group, a heptyloxymethyl group, and an octyloxymethyl group.

[0023] The organic group having a total of 1 to 18 carbon atoms and having at least one substituent selected from the group consisting of a sulfonic acid group and a phosphonic acid group is not particularly limited, and examples thereof include a methyl sulfonate group, a methyl phosphonate group, a 2-ethyl sulfonate group, a 2-ethyl phosphonate group, a 3-propyl sulfonate group, a 3-propyl phosphonate group, a 2-propyl sulfonate group, a 2-propyl phosphonate group, a 4-butyl sulfonate group, a 4-butyl phosphonate group, a 3-butyl sulfonate group, a 3-butyl phosphonate group, a 6-hexyl sulfonate group, a 6-hexyl phosphonate group, a 5-hexyl sulfonate group, a 5-hexyl phosphonate group, Examples of such alkyl groups include methoxymethyl sulfonate, methoxymethyl phosphonate, ethoxymethyl 2-sulfonate, ethoxymethyl 2-phosphonate, 3-propoxymethyl sulfonate, propoxymethyl 3-phosphonate, propoxymethyl 2-sulfonate, propoxymethyl 2-phosphonate, propoxymethyl 2-phosphonate, butoxymethyl 4-sulfonate, butoxymethyl 4-phosphonate, butoxymethyl 3-sulfonate, butoxymethyl 3-phosphonate, hexyloxymethyl 6-sulfonate, hexyloxymethyl 6-phosphonate, hexyloxymethyl 5-sulfonate, and hexyloxymethyl 5-phosphonate.

[0024] The structural unit represented by the general formula (2) represents the doped state of the structural unit represented by the general formula (1).

[0025] The polythiophene (A) is preferably a polythiophene (A') containing at least one structural unit selected from the group consisting of structural units represented by the following general formula (1') and structural units represented by the following general formula (2'), or a polythiophene (A'') containing at least one structural unit selected from the group consisting of structural units represented by the following general formula (1'') and structural units represented by the following general formula (2''), in that it can provide an electrolytic capacitor exhibiting lower ESR characteristics:

[0026] [In general formulas (1') and (2'), R ２represents a hydrogen atom, a methyl group, an ethyl group, a linear or branched alkyl group having 3 to 6 carbon atoms, or a fluorine atom, m represents an integer of 1 to 10, and n represents 0 or 1.

[0027] In the above general formulas (1') and (2'), the linear or branched alkyl group having 3 to 6 carbon atoms is not particularly limited, but examples thereof include an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a neopentyl group, a tert-pentyl group, a cyclopentyl group, an n-hexyl group, a 2-ethylbutyl group, and a cyclohexyl group.

[0028] In the above general formulas (1') and (2'), R ２ In terms of film-forming properties, it is preferable that the group be a hydrogen atom, a methyl group, an ethyl group, or a fluorine atom.

[0029] In the above general formulas (1') and (2'), m represents an integer of 1 to 10, and from the viewpoint of film-forming properties, it is preferably an integer of 1 to 6, more preferably an integer of 1 to 4, and even more preferably 2 or 3.

[0030] In the above general formulas (1') and (2'), n represents 0 or 1, and n is preferably 1 in terms of excellent conductivity.

[0031] The structural unit represented by the general formula (2') represents the doped state of the structural unit represented by the general formula (1').

[0032] [In the above general formula (1″), M ＋ represents a hydrogen ion. In the above general formulas (1″) and (2″), R ３ R independently represents a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, or a halogen atom. ４ represents a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms, p represents 0 or 1, q represents an integer of 0 to 6, and r represents 0 or 1.

[0033] R in the above general formulas (1″) and (2″) ３represents a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, or a halogen atom.

[0034] Examples of the linear or branched alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a neopentyl group, a tert-pentyl group, a cyclopentyl group, an n-hexyl group, a 2-ethylbutyl group, and a cyclohexyl group.

[0035] The halogen atom includes a fluorine atom, a chlorine atom, a bromine atom, and the like.

[0036] The above R ３ Regarding (I), a hydrogen atom, a methyl group, an ethyl group, or a fluorine atom is preferable, a hydrogen atom or a methyl group is more preferable, and a hydrogen atom is even more preferable, in that an electrolytic capacitor exhibiting lower ESR characteristics can be provided.

[0037] R in the above general formulas (1″) and (2″) ４ represents a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms.

[0038] Examples of the linear or branched alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a neopentyl group, a tert-pentyl group, a cyclopentyl group, an n-hexyl group, a 2-ethylbutyl group, and a cyclohexyl group.

[0039] The above R ４ Regarding the group (I), a hydrogen atom, a methyl group, or an ethyl group is preferred, and a hydrogen atom is more preferred, in that an electrolytic capacitor exhibiting lower ESR characteristics can be provided.

[0040] In the above general formulas (1'') and (2''), q represents an integer of 0 to 6, and is preferably 0 in that it can provide an electrolytic capacitor exhibiting lower ESR characteristics.

[0041] In the above general formulas (1'') and (2''), r represents 0 or 1, and is preferably 0 in that it can provide an electrolytic capacitor exhibiting lower ESR characteristics.

[0042] The structural unit represented by the general formula (2'') represents the doped state of the structural unit represented by the formula (1'').

[0043] Dopants that cause an insulator-metal transition through doping can be divided into acceptors and donors. The former enters the vicinity of the polymer chain of a conductive polymer through doping and removes π electrons from the conjugated system of the main chain. As a result, positive charges (holes) are injected into the main chain, and so they are also called p-type dopants. Conversely, the latter donates electrons to the conjugated system of the main chain, and these electrons move through the conjugated system of the main chain, so they are also called n-type dopants.

[0044] The dopant in this embodiment is a sulfo group or sulfonate group covalently bonded within the polymer molecule, and is a p-type dopant. Polymers that exhibit conductivity without the addition of an external dopant are called self-doping polymers.

[0045] As the polythiophene (A) of this embodiment, commercially available products can be used, or products produced based on a generally known method can also be used.

[0046] In this embodiment, the conductivity of the polythiophene (A) is not particularly limited, but it is preferable that the conductivity (electrical conductivity) in a film state is 10 S / cm or more.

[0047] The polythiophene (A) used in this embodiment may be synthesized based on publicly known information.

[0048] In the conductive polymer composition of this embodiment, the content of the polythiophene (A) containing at least one structural unit selected from the group consisting of the structural unit represented by the general formula (1) and the structural unit represented by the general formula (2) is 0.01 to 10 mass %, where the total amount of the conductive polymer composition is 100 mass %. However, from the viewpoint of being able to provide an electrolytic capacitor with excellent low ESR, the content is preferably 0.05 to 8 mass %, and more preferably 0.1 to 7 mass %.

[0049] The nanostructured material (B) is not particularly limited, but is preferably at least one selected from the group consisting of cellulose nanofibers, single-walled carbon nanotubes, double-walled carbon nanotubes, and multi-walled carbon nanotubes, and more preferably cellulose nanofibers or single-walled carbon nanotubes in that they can provide an electrolytic capacitor with excellent low ESR.

[0050] The diameter of the single-walled, double-walled, or multi-walled carbon nanotubes is not particularly limited, but may be, for example, 20 nm or less, preferably 10 nm or less, and more preferably 5 nm or less. The lower limit of the diameter of the single-walled, double-walled, or multi-walled carbon nanotubes is not particularly limited, but may be, for example, 0.4 nm or more, or 0.5 nm.

[0051] Such nanostructured material (B) may be a commercially available product or may be prepared by a known method. Nanostructured material (B) is often sold commercially as an aqueous dispersion for reasons of stability. The composition of the present invention may be prepared using the aqueous dispersion of nanostructured material (B) as is, or may be prepared using an aqueous dispersion of nanostructured material (B) that has been subjected to solvent removal and purification.

[0052] In the conductive polymer composition of this embodiment, the content of the nanostructured material (B) is 0.001 to 10 mass %, where the total amount of the conductive polymer composition is 100 mass %. However, in terms of providing an electrolytic capacitor with excellent low ESR, the content is more preferably 0.01 to 7 mass %, even more preferably 0.01 to 5 mass %, and particularly preferably 0.05 to 3 mass %.

[0053] In order to provide an electrolytic capacitor having excellent low ESR, the content of the nanostructure material (B) relative to 1 part by mass of the polythiophene (A) is preferably 0.01 to 7 parts by mass, more preferably 0.01 to 5 parts by mass, and particularly preferably 0.05 to 3 parts by mass.

[0054] The polyglycerin refers to a compound having a structure in which a plurality of glycerins are polymerized, and is not particularly limited, but examples thereof include diglycerin, triglycerin, tetraglycerin, and decaglycerin.

[0055] The sugar alcohol is not particularly limited, but examples thereof include erythritol, glycerin, lactitol, maltitol, xylitol, arabitol, mannitol, sorbitol, etc. The sugar alcohol used in this embodiment may be used alone or in combination of two or more. Note that, as for the sugar alcohol, commercially available products may be used as they are, or those produced according to a generally known method may be used.

[0056] The at least one selected from the group consisting of polyglycerin and sugar alcohol (C) is preferably diglycerin, triglycerin, polyglycerin, mannitol, sorbitol, erythritol, xylitol, or lactitol, and more preferably polyglycerin, sorbitol, or mannitol, in that an electrolytic capacitor having excellent low ESR characteristics can be provided.

[0057] Furthermore, in the conductive polymer composition of this embodiment, the content of the at least one member (C) selected from the group consisting of polyglycerols and sugar alcohols is 1 to 50 mass %, with the total amount of the conductive polymer composition being 100 mass %. In terms of being able to provide an electrolytic capacitor with excellent low ESR characteristics, the content is more preferably 5 to 50 mass %, more preferably 7 to 50 mass %, and even more preferably 10 to 50 mass %.

[0058] The content of at least one member (C) selected from the group consisting of polyglycerols and sugar alcohols is preferably 3 to 50 parts by mass, more preferably 5 to 40 parts by mass, and even more preferably 7 to 30 parts by mass, per part by mass of the polythiophene (A).

[0059] The solvent is not particularly limited, but examples thereof include water, polyhydric alcohols such as ethylene glycol, propylene glycol, and diethylene glycol; cyclic sulfones such as sulfolane; lactones such as γ-butyrolactone; amides such as N-methylacetamide, N,N-dimethylformamide, and N-methyl-2-pyrrolidone; esters such as methyl acetate; carbonate compounds such as propylene carbonate; ethers such as 1,4-dioxane; ketones such as methyl ethyl ketone; and polymer solvents such as polyethylene glycol and polypropylene glycol.

[0060] Furthermore, in the conductive polymer composition of this embodiment, the content of the solvent is more preferably 50 to 99 mass %, more preferably 70 to 99 mass %, and even more preferably 80 to 99 mass %, based on the total amount of the conductive polymer composition being 100 mass %, in terms of being able to provide an electrolytic capacitor with excellent low ESR characteristics.

[0061] The conductive polymer composition of this embodiment may further contain poly(meth)acrylic acid (D). The poly(meth)acrylic acid (D) refers to a polymer obtained by polymerizing acrylic acid monomers and / or methacrylic acid monomers (other copolymers may be present during polymerization), and is not particularly limited, and examples thereof include an acrylic acid polymer, a methacrylic acid polymer, an acrylic acid-methacrylic acid copolymer, an acrylic acid copolymer, and a methacrylic acid copolymer.

[0062] In the conductive polymer composition of this embodiment, the weight average molecular weight of the poly(meth)acrylic acid (D) is not particularly limited, but is preferably 100 to 1,000,000, more preferably 1,000 to 500,000, even more preferably 2,000 to 100,000, and particularly preferably 5,000 to 50,000. This configuration has the advantage of being able to provide an electrolytic capacitor with excellent low ESR characteristics.

[0063] In the conductive polymer composition of this embodiment, the content of the poly(meth)acrylic acid (D) is preferably 0.001 to 20 mass %, with the total amount of the conductive polymer composition in a state containing the poly(meth)acrylic acid (D) being 100 mass %, and from the viewpoint of being able to provide an electrolytic capacitor with excellent low ESR characteristics, the content is more preferably 0.01 to 20 mass %, and even more preferably 0.1 to 20 mass %.

[0064] The content of the poly(meth)acrylic acid (D) is preferably 0.1 to 10 parts by mass, more preferably 0.2 to 8 parts by mass, and even more preferably 0.3 to 6 parts by mass, per part by mass of the polythiophene (A). This configuration has the advantage of being able to provide an electrolytic capacitor with excellent low ESR characteristics.

[0065] The conductive polymer composition of this embodiment may further contain a compound (E) capable of forming an ion pair with the sulfonic acid group or phosphonic acid group of the polythiophene (A).

[0066] The compound (E) capable of forming an ion pair with the sulfonic acid group or phosphonic acid group of the polythiophene (A) is not particularly limited, and examples thereof include alkali metal compounds, ammonia, organic amine compounds, and quaternary ammonium salts. These compounds react with the sulfonic acid group or phosphonic acid group of the polythiophene (A) to form alkali metal ion salts, ammonium ion salts, organic ammonium ion salts, or quaternary ammonium ion salts of the polythiophene (A), respectively.

[0067] The alkali metal compound is not particularly limited, but examples thereof include alkali metal salt compounds (e.g., lithium chloride, potassium chloride, sodium chloride, rubidium chloride, cesium chloride, lithium bromide, potassium bromide, sodium bromide, rubidium bromide, cesium bromide, etc.) and alkali metal hydroxides (e.g., lithium hydroxide, potassium hydroxide, sodium hydroxide, rubidium hydroxide, cesium hydroxide, etc.).

[0068] The alkali metal ion salt of polythiophene (A) can be prepared by adding the alkali metal compound to the conductive polymer composition of the present embodiment. The alkali metal ion is not particularly limited, but examples thereof include lithium ion, potassium ion, sodium ion, rubidium ion, and cesium ion.

[0069] The organic amine compound is not particularly limited, and examples thereof include primary, secondary, or tertiary organic amine compounds having a total carbon number of 1 to 30. More specific examples thereof include methylamine, dimethylamine, trimethylamine, ethylamine, triethylamine, normal-propylamine, isopropylamine, normal-butylamine, hexylamine, ethanolamine, dimethylaminoethanol, methylaminoethanol, diethanolamine, N-methyldiethanolamine, triethanolamine, 3-amino-1,2-propanediol, 3-methylamino-1,2-propanediol, 3-dimethylamino-1,2-propanediol, 2-amino-2-hydroxymethyl-1,3-propanediol, 1,4-butanediamine, triisobutylamine, triisopentylamine, triisooctylamine, imidazole, N-methylimidazole, 1,2-dimethylimidazole, pyridine, picoline, and lutidine.

[0070] By incorporating the organic amine compound into the conductive polymer composition of this embodiment, the organic amine compound reacts with the polythiophene (A) to form an organic ammonium ion, thereby preparing an organic ammonium ion salt of the polythiophene (A). The organic ammonium ion is not particularly limited, but examples thereof include primary, secondary, and tertiary organic ammonium ions having a total carbon number of 1 to 30. More specific examples include methylammonium, dimethylammonium, trimethylammonium, ethylammonium, triethylammonium, normal-propylammonium, isopropylammonium, normal-butylammonium, hexylammonium, 2-hydroxyethylammonium, N,N-dimethyl-N-(2-hydroxyethyl)ammonium, N-methyl-N-(2-hydroxyethyl)ammonium, di(2-hydroxyethyl)ammonium, and the like. ammonium, N-methyl-N,N-di(2-hydroxyethyl)ammonium, N,N,N-tri(2-hydroxyethyl)ammonium, 2,3-dihydroxypropylammonium, N-methyl-N-(2,3-dihydroxypropyl)ammonium, N,N-dimethyl-N-(2,3-dihydroxypropyl)ammonium, 1,4-butanediammonium, triisobutylammonium, triisopentylammonium, triisooctylammonium, imidazole cation, N-methylimidazole cation, 1,2-dimethylimidazole cation, pyridinium ion, picolinium ion, or lutidinium ion.

[0071] The quaternary ammonium salt is not particularly limited, but examples thereof include tetramethylammonium chloride, tetraethylammonium chloride, tetra-normal-propylammonium chloride, tetra-normal-butylammonium chloride, and tetra-normal-hexylammonium chloride.

[0072] By incorporating the quaternary ammonium salt into the conductive polymer composition of one embodiment of the present invention, the quaternary ammonium salt reacts with the polythiophene (A) to form a quaternary ammonium ion, thereby preparing a quaternary ammonium ion salt of polythiophene (A). The quaternary ammonium ion is not particularly limited, and examples thereof include tetramethylammonium ion, tetraethylammonium ion, tetra-n-propylammonium ion, tetra-n-butylammonium ion, and tetra-n-hexylammonium ion.

[0073] The compound (E) capable of forming an ion pair with the sulfonic acid group or phosphonic acid group of the polythiophene (A) is preferably an alkali metal hydroxide, ammonia, or a primary, secondary, or tertiary organic amine compound having a total carbon number of 1 to 16, in terms of being able to provide an electrolytic capacitor with excellent low ESR. Examples of the primary, secondary, or tertiary organic amine compound having a total carbon number of 1 to 16 include methylamine, dimethylamine, trimethylamine, ethylamine, triethylamine, normal-propylamine, isopropylamine, normal-butylamine, hexylamine, ethanolamine, dimethylaminoethanol, methylaminoethanol, diethanolamine, N-methyldiethanolamine, triethanolamine, 3-amino-1,2-propanediol, 3-methylamino-1,2-propanediol, 3-dimethylamino-1,2-propanediol, 1,4-butanediamine, triisobutylamine, triisopentylamine, imidazole, N-methylimidazole, 1,2-dimethylimidazole, pyridine, picoline, and lutidine.

[0074] When the conductive polymer composition of the present embodiment contains the compound (E), a part or all of the polythiophene (A) containing at least one structural unit selected from the group consisting of structural units represented by the general formula (1) and structural units represented by the general formula (2) interacts with the compound (E) to form a polythiophene (A''') containing at least one structural unit selected from the group consisting of structural units represented by the following general formula (1''') and structural units represented by the general formula (2'''):

[0075] [In the above general formula (1'''), M represents a hydrogen ion, an alkali metal ion, an ammonium ion, an organic ammonium ion, or a quaternary ammonium ion. In the above general formulas (1''') and (2'''), the definition and preferred range of R are the same as the definition and preferred range of R shown in the above general formulas (1) and (2).]

[0076] When the conductive polymer composition of the present embodiment contains the compound (E), a part or all of the polythiophene (A') containing at least one structural unit selected from the group consisting of the structural unit represented by the general formula (1') and the structural unit represented by the general formula (2') interacts with the compound (E) to form a polythiophene (A'''') containing at least one structural unit selected from the group consisting of the structural unit represented by the following general formula (1'''') and the structural unit represented by the general formula (2''''):

[0077] [In the general formula (1'''') and the general formula (2''''), R ２ The definitions and preferred ranges of m and n are as defined in the R ２ The definitions and preferred ranges of m and n are the same as those of m and n. M represents a hydrogen ion, an alkali metal ion, an ammonium ion, an organic ammonium ion, or a quaternary ammonium ion.

[0078] The alkali metal ion, ammonium ion, organic ammonium ion, and quaternary ammonium ion in M ​​are as described above.

[0079] In the conductive polymer composition of this embodiment, the content of the compound (E) capable of forming an ion pair with a sulfonic acid group or a phosphonic acid group of the polythiophene (A) is preferably 0.001 to 20 mass %, and more preferably 0.01 to 20 mass %, and even more preferably 0.1 to 20 mass %, relative to the total amount of the conductive polymer composition including the compound (E), which is taken as 100 mass %. In terms of being able to provide an electrolytic capacitor with excellent low ESR characteristics, the content is more preferably 0.01 to 20 mass %, and even more preferably 0.1 to 20 mass %.

[0080] From the viewpoint of excellent chemical stability, the conductive polymer composition of the present embodiment preferably further contains a conductive polymer (F) that is a composite of a polyanion and a poly(3,4-ethylenedioxythiophene derivative) containing a structural unit represented by the following general formula (3):

[0081] [In the general formula (3), R ３ represents a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 6 carbon atoms, a substituted alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a substituted alkoxy group having 1 to 6 carbon atoms.]

[0082] The conductive polymer (F) in the present embodiment can be obtained by oxidatively polymerizing a 3,4-ethylenedioxythiophene derivative monomer, which corresponds to a monomer for producing a poly(3,4-ethylenedioxythiophene derivative) containing a structural unit represented by the above general formula (3), in water in the presence of a polyanion.

[0083] In the above general formula (3), R ３ represents a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 6 carbon atoms, a substituted alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a substituted alkoxy group having 1 to 6 carbon atoms.

[0084] The alkyl group having 1 to 6 carbon atoms is not particularly limited, and examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, a neopentyl group, a tert-pentyl group, a cyclopentyl group, an n-hexyl group, a 2-ethylbutyl group, and a cyclohexyl group.

[0085] The alkyl group having 1 to 6 carbon atoms and having a substituent is not particularly limited, but examples thereof include a hydroxymethyl group, a trifluoromethyl group, an aminomethyl group, a hydroxyethyl group, a 1,1,1-trifluoroethyl group, a 2-aminoethyl group, a 2-hydroxypropyl group, a 2-hydroxy-3-methoxypropyl group, and a 2-hydroxycyclohexyl group.

[0086] The alkoxy group having 1 to 6 carbon atoms is not particularly limited, and examples thereof include a methoxy group, an ethoxy group, an n-propyloxy group, an isopropyloxy group, an n-butyloxy group, an isobutyloxy group, a sec-butyloxy group, a tert-butyloxy group, an n-pentyloxy group, an isopentyloxy group, a neopentyloxy group, a tert-pentyloxy group, a cyclopentyloxy group, an n-hexyloxy group, a 2-ethylbutyloxy group, and a cyclohexyloxy group.

[0087] The alkoxy group having 1 to 6 carbon atoms and having the aforementioned substituent is not particularly limited, but examples thereof include a hydroxymethyloxy group, a trifluoromethyloxy group, an aminomethyloxy group, a hydroxyethyloxy group, a 1,1,1-trifluoroethyloxy group, a 2-aminoethyloxy group, a 2-hydroxypropyloxy group, a 2-hydroxy-3-methoxypropyloxy group, and a 2-hydroxycyclohexyloxy group.

[0088] R ３Regarding (a), in terms of excellent moisture resistance, it is preferably any one selected from the group consisting of a hydrogen atom, a methoxy group, an ethoxy group, a propoxy group, a butoxy group, and a hydroxymethyl group, more preferably a hydrogen atom or a hydroxymethyl group, and even more preferably a hydrogen atom.

[0089] The 3,4-ethylenedioxythiophene derivative monomer from which the structural unit represented by the general formula (3) is derived may be used alone or in combination for polymerization. 3,4-ethylenedioxythiophene alone is more preferred.

[0090] The polyanion is not particularly limited, but examples thereof include polystyrene sulfonic acid, polyvinyl sulfonic acid, polyallyl sulfonic acid, etc., or metal salts thereof, ammonium salts thereof, amine salts thereof, etc. Among these, polystyrene sulfonic acid is preferred in that it can provide an electrolytic capacitor with excellent low ESR characteristics.

[0091] The conductive polymer (F) is preferably a composite of poly(3,4-ethylenedioxythiophene) (PEDOT) and polystyrene sulfonic acid (PSS) (hereinafter referred to as "PEDOT:PSS"), in that it can provide an electrolytic capacitor with excellent low ESR characteristics, and commercially available PEDOT:PSS can also be used.

[0092] Furthermore, in the conductive polymer composition of the present embodiment, the content of the conductive polymer (F) is preferably 0.001 to 20 parts by mass, more preferably 0.1 to 20 parts by mass, and even more preferably 1 to 20 parts by mass, relative to 1 part by mass of the polythiophene (A).

[0093] The conductive polymer composition of this embodiment may contain a component (G) other than those described above.

[0094] The component (G) other than those mentioned above is not particularly limited, but examples thereof include a binder and a surfactant.

[0095] The binder is not particularly limited, but examples thereof include polyvinyl alcohol, polyvinylpyrrolidone, cellulose, a water-soluble polyester resin compound, a water-soluble polyurethane resin compound, or a mixture of organic acids having two or more carboxyl groups.

[0096] Examples of the water-soluble polyester resin compound include polyethylene terephthalate, polytrimethylene terephthalate, etc. The water-soluble polyester resin compound may be a self-emulsifying type or a reinforced emulsifying type, but is preferably a self-emulsifying water-soluble polyester resin compound from the viewpoint of water resistance and solvent resistance.

[0097] Examples of the water-soluble polyester resin compound include those commercially available under the trade name Vylonal manufactured by Toyobo Co., Ltd., the trade name PES Resin manufactured by Takamatsu Oil & Fats Co., Ltd., the trade name PLASCOAT manufactured by Go-o Chemical Co., Ltd., the trade name Aronmelt manufactured by Toagosei Co., Ltd., the trade name PES Resin A manufactured by Takamatsu Oil & Fats Co., Ltd., and the trade name Watersol manufactured by DIC Corporation.

[0098] The water-soluble polyester resin compounds may be used alone or in combination of two or more.

[0099] The water-soluble polyurethane resin compound is mainly used in industrial applications as a urethane resin emulsion, and may be a self-emulsifying type or a reinforced emulsifying type. However, from the viewpoint of water resistance and solvent resistance, a self-emulsifying water-soluble polyurethane resin compound is preferable. Examples of the self-emulsifying type include an anionic type, a cationic type, and a nonionic type, and any of them may be used. Furthermore, the water-soluble polyurethane resin compound is not particularly limited, but examples thereof include a polyether type, a polyester type, and a polycarbonate type.

[0100] Examples of water-soluble polyurethane resin compounds that can be easily obtained commercially include those manufactured by Sanyo Chemical Industries, Ltd. under the trade names U-coat, Permalin, and Euplen, those manufactured by Kusumoto Chemicals Co., Ltd. under the trade name NeoRez, those manufactured by ADEKA Corporation under the trade name Adeka Bontiter, those manufactured by Meisei Chemical Industry Co., Ltd. under the trade name Pascol, and those manufactured by DIC Corporation under the trade name Hydran.

[0101] The water-soluble polyurethane resin compounds may be used alone or in combination of two or more.

[0102] The organic acid having two or more carboxyl groups is not particularly limited, but examples thereof include adipic acid and phthalic acid.

[0103] The surfactant is not particularly limited, but examples thereof include anionic surfactants, cationic surfactants, nonionic surfactants, amphoteric surfactants, fluorine-based surfactants, and silicone-based surfactants, and more preferably at least one selected from the group consisting of nonionic surfactants and amphoteric surfactants.

[0104] The anionic surfactant is not particularly limited, but examples thereof include sodium lauryl alcohol sulfate and sodium dodecylbenzenesulfonate.

[0105] The cationic surfactant is not particularly limited, but a commercially available product can be used, or a commonly known product can be separately produced and used.

[0106] The nonionic surfactant is not particularly limited, but examples thereof include polyethylene glycol surfactants, acetylene glycol surfactants, polyhydric alcohol surfactants, and polymeric nonionic surfactants.

[0107] The polyethylene glycol surfactant is not particularly limited, but examples thereof include higher alcohol ethylene oxide adducts, alkylphenol ethylene oxide adducts, fatty acid ethylene oxide adducts, polyhydric alcohol fatty acid ester ethylene oxide adducts, higher alkylamine ethylene oxide adducts, ethylene oxide adducts of fats and oils, and polypropylene glycol ethylene oxide adducts.

[0108] The acetylene glycol surfactant is not particularly limited, but examples thereof include 2,4,7,9-tetramethyl-5-decyne-4,7-diol, Surfynol (manufactured by Air Products Co., Ltd.), and Olfine (manufactured by Nissin Chemical Industry Co., Ltd.).

[0109] The polyhydric alcohol surfactant is not particularly limited, but examples thereof include fatty acid esters of glycerol, fatty acid esters of pentaerythritol, fatty acid esters of sorbitol and sorbitan, fatty acid esters of sucrose, alkyl ethers of higher alcohols, and fatty acid amides of alkanolamines.

[0110] The amphoteric surfactant is not particularly limited, but examples thereof include betaine-type amphoteric surfactants, such as alkyl dimethyl betaine, lauryl dimethyl betaine, stearyl dimethyl betaine, and lauryl dihydroxyethyl betaine.

[0111] The fluorine-based surfactant is not particularly limited as long as it has a perfluoroalkyl group, and examples thereof include PLASCOAT RY-2, perfluoroalkane, perfluoroalkylcarboxylic acid, perfluoroalkylsulfonic acid, and perfluoroalkylethylene oxide adducts.

[0112] The silicone surfactant is not particularly limited, but examples thereof include polyether-modified polydimethylsiloxane, polyetherester-modified polydimethylsiloxane, hydroxyl group-containing polyether-modified polydimethylsiloxane, acrylic group-containing polyether-modified polydimethylsiloxane, methacrylic group-containing polyether-modified polydimethylsiloxane, acrylic group-containing polyester-modified polydimethylsiloxane, methacrylic group-containing polyester-modified polydimethylsiloxane, perfluoropolyether-modified polydimethylsiloxane, perfluoropolyester-modified polydimethylsiloxane, silicone-modified acrylic compound, and silicone-modified methacrylic compound.

[0113] In addition, fluorine-based surfactants or silicone-based surfactants are effective as leveling agents to improve the flatness of the coating film.

[0114] In the conductive polymer composition of the present embodiment, the content of the aforementioned component (G) is preferably 0.001 to 20 mass %, and from the viewpoint of excellent operability, is more preferably 0.01 to 15 mass %, and even more preferably 0.1 to 10 mass %, relative to 100 mass % of the total amount of the conductive polymer composition including the component (G).

[0115] The pH of the conductive polymer composition of this embodiment is not particularly limited, but is preferably 1.5 to 5.0, more preferably 2.0 to 4.0, even more preferably 2.5 to 3.5, even more preferably 2.75 to 3.25, and particularly preferably 3.0. This configuration has the advantage of being able to provide an electrolytic capacitor exhibiting low ESR characteristics. The pH of the conductive polymer composition can be controlled by the type and content of the compound (E) capable of forming an ion pair with the above-mentioned sulfonic acid group or phosphonic acid group.

[0116] The method for preparing the conductive polymer composition of this embodiment is not particularly limited, but may include, for example, a method in which a solution or solid of the polythiophene (A), a nanostructured material (B), at least one member (C) selected from the group consisting of polyglycerin and sugar alcohol, a solvent, and, if necessary, poly(meth)acrylic acid (D), a compound (E) capable of forming an ion pair with a sulfonic acid group or a phosphonic acid group of the polythiophene (A), a conductive polymer (F), and / or a component (G) are mixed together, and the mixture is homogenized by stirring or the like.

[0117] The temperature at which the mixture is mixed is not particularly limited, but may be, for example, from room temperature to heated, preferably from 0 to 100°C.

[0118] The atmosphere in which the mixture is mixed is not particularly limited, but may be air or an inert gas.

[0119] When mixing the conductive polymer composition of this embodiment, a general mixing and dissolving operation using a stirrer tip or a stirring blade can be used. Alternatively, ultrasonic irradiation or homogenization (using, for example, a mechanical homogenizer, an ultrasonic homogenizer, or a high-pressure homogenizer) may be performed for mixing. When homogenization is performed, it is preferable to perform the homogenization at a low temperature to prevent thermal degradation of the polymer.

[0120] The concentration of the conductive polymer composition of this embodiment may be adjusted by the blending ratio, or may be adjusted by concentrating the composition after blending. The concentrating method may be a method of distilling off the solvent under reduced pressure or a method using an ultrafiltration membrane.

[0121] The content of polythiophene (A) in the conductive polymer composition of this embodiment is not particularly limited as long as it is 0.01 to 10% by mass. Note that the conductive polymer composition containing polythiophene (A), nanostructured material (B), and at least one member (C) selected from the group consisting of polyglycerin and sugar alcohol is dried and dehydrated after application, so by setting the content within the above range, a good uniform film can be obtained.

[0122] The particle size of the solid content of the conductive polymer solution composition of this embodiment is not particularly limited, but the smaller the particle size, the better the water solubility, and this is also desirable from the viewpoints of conductivity and uniform film formation during film formation. For example, when the solid content concentration of the conductive polymer composition prepared at room temperature or under heating is 10 mass % or less, the particle size (D50) of the solid content is preferably 0.02 μm or less.

[0123] The viscosity (20° C.) of the conductive polymer composition of this embodiment is preferably 200 mPa·s or less, more preferably 150 mPa·s or less, and even more preferably 100 mPa·s or less.

[0124] The conductive polymer film of this embodiment can be formed using the conductive polymer composition of this embodiment. The method for forming the conductive polymer film of this embodiment (production method) is not particularly limited, but may include, for example, a method including a step of applying the conductive polymer composition of this embodiment to a substrate and drying it.

[0125] The drying atmosphere may be air, an inert gas, a vacuum, or a reduced pressure, but from the viewpoint of preventing deterioration of the polymer film, an inert gas such as nitrogen or argon is preferred.

[0126] The substrate is not particularly limited, but examples thereof include glass, plastic, polyester, polyacrylate, polycarbonate, metal oxide, ceramic, and resist substrates.

[0127] The coating method is not particularly limited, but examples thereof include casting, dipping, bar coating, roll coating, gravure coating, flexographic printing, spray coating, spin coating, and inkjet printing.

[0128] The drying temperature for the coating film is not particularly limited as long as a uniform conductive film can be obtained, but is preferably in the range of room temperature to 300° C., more preferably in the range of room temperature to 250° C., and even more preferably in the range of room temperature to 200° C. In this specification, room temperature means 15 to 25° C.

[0129] The thickness of the coating film is not particularly limited, but －２ ~10 ２ The surface resistivity of the resulting coating film is not particularly limited, but is preferably in the range of 1 to 10 ９ A range of Ω / □ is preferred.

[0130] The conductivity of the conductive polymer film obtained in this embodiment is not particularly limited, but it is preferable that the conductivity (electrical conductivity) in the film state is 10 S / cm or more.

[0131] The conductive polymer film of this embodiment can be used, for example, as an antistatic agent, a solid electrolyte for an electrolytic capacitor, a conductive paint, an electrochromic element, an electrode material, a thermoelectric conversion material, a transparent conductive film, a chemical sensor, or an actuator. It is particularly useful as a solid electrolyte for an electrolytic capacitor. When the conductive polymer film of this embodiment is used in an electrolytic capacitor, it is possible to provide an electrolytic capacitor with excellent low ESR characteristics while maintaining a high capacity.

[0132] Furthermore, the conductive polymer film of this embodiment can provide electrolytic capacitors and the like with long life, which can contribute to improving energy efficiency, thereby contributing to the achievement of the Sustainable Development Goals (SDGs).

[0133] A method for producing the electrolytic capacitor of this embodiment may include a method including the steps of covering the surface of the dielectric oxide film of an anode body on which a dielectric oxide film has been formed with the conductive polymer composition of this embodiment and drying by heating. More specifically, the method for producing the electrolytic capacitor of this embodiment may include the steps of immersing an element including an anode body and a cathode in the conductive polymer composition of this embodiment and drying by heating.

[0134] The electrolytic capacitor in this embodiment is not particularly limited, but may be, for example, an aluminum wound electrolytic capacitor, an aluminum laminated electrolytic capacitor, or a tantalum electrolytic capacitor.

[0135] The electrolytic solution in this embodiment is not particularly limited, but may be, for example, an electrolytic solution containing a solvent and a base component dissolved in the solvent.

[0136] In this embodiment, the anode body preferably includes a dielectric oxide film (dielectric layer) and an anode. The dielectric layer can also be said to be made of an oxide film.

[0137] In the present embodiment, the anode is not particularly limited, but is preferably one or more selected from the group consisting of aluminum, tantalum, niobium, and titanium, and more preferably made of aluminum, in terms of ease of forming a dielectric layer.

[0138] In this embodiment, the oxide film constituting the dielectric layer is preferably formed by oxidizing the surface of the anode. The method for forming the oxide film on the surface of the anode (i.e., the method for manufacturing the anode body) is not particularly limited, but examples thereof include a method of oxidizing the anode by applying a voltage in a buffer solution.

[0139] In the present embodiment, the cathode is not particularly limited, but is preferably one or more selected from the group consisting of aluminum, silver, tantalum, niobium, and titanium, and more preferably made of aluminum, in terms of ease of forming a dielectric layer.

[0140] The drying temperature in the method for producing the electrolytic capacitor of this embodiment can be the same as that described for the drying temperature of the coating film in the method for forming the conductive polymer film (production method) of this embodiment.

[0141] Furthermore, among the electrolytic capacitors of this embodiment, a hybrid capacitor can be obtained, for example, by obtaining a solid electrolytic capacitor by the above-described method and then immersing the solid electrolytic capacitor in an electrolytic solution. In other words, the method for producing the electrolytic capacitor of this embodiment includes the steps of covering the surface of the dielectric oxide film of the anode body on which the dielectric oxide film has been formed with the conductive polymer composition of this embodiment and heating and drying, and further impregnating the anode body with an electrolytic solution and heating and drying again.

[0142] [Summary] As a result of extensive research, the present inventors have found that the following conductive polymer composition can solve the problems of the present invention, and have thus completed the present invention.

[0143] That is, one aspect of the present invention relates to a conductive polymer composition, a conductive polymer film, and an electrolytic capacitor using the conductive polymer composition, as described below.

[0144] [1] A conductive polymer composition comprising: 0.01 to 10% by mass of a polythiophene (A) containing at least one structural unit selected from the group consisting of a structural unit represented by the following general formula (1) and a structural unit represented by the following general formula (2); 0.001 to 10% by mass of a nanostructured material (B); 1 to 50% by mass of at least one member (C) selected from the group consisting of polyglycerin and sugar alcohol; and a solvent.

[0145] [In the above general formula (1), M ＋ represents a hydrogen ion. In the above general formulas (1) and (2), R represents an organic group having a total of 1 to 18 carbon atoms and having at least one substituent selected from the group consisting of a sulfonic acid group and a phosphonic acid group.]

[0146] [2] The conductive polymer composition according to [1], wherein the nanostructured material (B) is at least one selected from the group consisting of cellulose nanofibers, single-walled carbon nanotubes, double-walled carbon nanotubes, and multi-walled carbon nanotubes.

[0147] [3] The conductive polymer composition according to [1] or [2], wherein the nanostructured material (B) is a cellulose nanofiber or a single-walled carbon nanotube.

[0148] [4] The conductive polymer composition according to any one of [1] to [3], wherein the sugar alcohol is sorbitol, mannitol, erythritol, xylitol, or lactitol.

[0149] [5] The conductive polymer composition according to any one of [1] to [4], further comprising 0.001 to 20 mass % of poly(meth)acrylic acid (D).

[0150] [6] The conductive polymer composition according to any one of [1] to [5], further comprising 0.001 to 20 mass % of a compound (E) capable of forming an ion pair with a sulfonic acid group or a phosphonic acid group of the polythiophene (A).

[0151] [7] The conductive polymer composition according to any one of [1] to [6], wherein the content of the nanostructured material (B) is 0.01 to 5 parts by mass per part by mass of the polythiophene (A).

[0152] [8] The conductive polymer composition according to any one of [1] to [7], wherein the content of the at least one member (C) selected from the group consisting of polyglycerin and sugar alcohol is 3 to 50 parts by mass per part by mass of the polythiophene (A).

[0153] [9] The conductive polymer composition according to [5], wherein the content of the poly(meth)acrylic acid (D) is 0.1 to 10 parts by mass per part by mass of the polythiophene (A).

[0154]

[10] The conductive polymer composition according to any one of [1] to [9], further comprising a conductive polymer (F) that is a composite of a polyanion and a poly(3,4-ethylenedioxythiophene derivative) containing a structural unit represented by the following general formula (3), wherein the content of the conductive polymer (F) is 0.001 to 20 parts by mass per part by mass of the polythiophene (A):

[0155] [In the formula, R ３ represents a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 6 carbon atoms, a substituted alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a substituted alkoxy group having 1 to 6 carbon atoms.]

[0156]

[11] R ３ is a hydrogen atom.

[0157]

[12] The conductive polymer composition according to

[10] or

[11] , wherein the conductive polymer (F) is PEDOT:PSS.

[0158]

[13] A method for producing an electrolytic capacitor, comprising the steps of covering a surface of the dielectric oxide film of an anode body on which the dielectric oxide film has been formed with the conductive polymer composition according to any one of [1] to

[12] , and drying by heating.

[0159]

[14] A method for producing an electrolytic capacitor, comprising the steps of covering a surface of the dielectric oxide film of an anode body on which the dielectric oxide film has been formed with the conductive polymer composition according to any one of [1] to

[12] and drying by heating, and further impregnating the surface with an electrolytic solution and drying by heating again.

[0160] [Additional Notes] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention.

[0161] The present invention will be described in detail below with reference to examples, but the present invention should not be construed as being limited thereto.

[0162] The analytical instruments and measurement methods used in the present examples are listed below.

[0163] [Measurement of Electrical Conductivity of Polythiophene (A)] 0.5 ml of an aqueous solution containing PEDOT-MPS (corresponding to polythiophene (A) according to one embodiment of the present invention) described below was applied to a 25 mm square alkali-free glass plate, heated on a hot plate in the atmosphere at 60°C for 30 minutes, and further heated at 200°C for 60 minutes to obtain a conductive polymer film.

[0164] The conductive polymer film was cut at intervals of 6.25 mm in the x direction and 6.25 mm in the y direction to expose the glass portion, and the film thickness at nine measurement points was measured in an atmosphere of 25°C and 50% RH. The measurement device used was a DEKTAK XT manufactured by BRUKER. The surface resistivity at the nine measurement points was also measured in an atmosphere of 25°C and 50% RH. The measurement device used was a surface resistance measuring device Loresta GP MCP-T600 manufactured by Mitsubishi Chemical Corporation, and the measurement probe was an ASP.

[0165] The conductivity was calculated from the film thickness and surface resistivity of the conductive polymer film measured by the above-mentioned measuring method according to the following formula: Conductivity [S / cm]=10 ４

[0043] / (surface resistivity [Ω / □] × film thickness [μm]) [Fabrication of Solid Electrolytic Capacitor] Aluminum foil was welded to a part of a 100 μm-thick etched aluminum foil, and a lead wire was attached (anode). The etched aluminum foil was immersed in a 0.2 wt % aqueous solution of ammonium dihydrogen phosphate at a liquid temperature of 80°C, and a DC voltage of 130 V was applied for 20 minutes to form a dielectric layer made of aluminum oxide (i.e., an aluminum oxide film) on the surface of the anode (anode body).

[0166] Separately, a 50 μm thick etched aluminum foil with a lead wire attached was used as a cathode, and a separator made of insulating paper was interposed between the anode body and the cathode, to prepare a wound element. The wound element was then immersed in a conductive polymer composition described below, removed, and then dried at 150° C. for 30 minutes to prepare an unsealed solid electrolytic capacitor element.

[0167] [Fabrication of Hybrid Capacitor] The solid electrolytic capacitor element fabricated by the above method was immersed in ethylene glycol to obtain an unsealed hybrid capacitor element.

[0168] [Measurement of Capacitor Element Characteristics] Apparatus: LCR meter IM3536 manufactured by Hioki E.E. Corporation The characteristics of the solid electrolytic capacitor elements and hybrid capacitor elements prepared by the above-described methods were evaluated using the above-described apparatus, including the initial capacitance [μF] at 120 Hz and the initial ESR [mΩ] at 100 kHz.

[0169] Here, for the "solid electrolytic capacitor," if the initial capacitance [μF] at 120 Hz was 100 μF or more, it was determined that the "solid electrolytic capacitor has high capacitance."

[0170] Furthermore, for the "solid electrolytic capacitor," if the initial ESR [mΩ] at 100 kHz was 15.0 mΩ or less, it was determined that "the solid electrolytic capacitor exhibits low ESR characteristics."

[0171] Furthermore, the "hybrid capacitor element" was left at 150° C. for 500 hours, and then the capacitance [μF] at 120 Hz and the ESR [mΩ] at 100 kHz were also evaluated.

[0172] The inventors also found that if the 120 Hz capacitance [μF] and 100 kHz ESR [mΩ] of a "hybrid capacitor element" after 500 hours at 150°C are good values, high capacitance and low ESR characteristics can be maintained for a long time (several thousand hours) at temperatures lower than 150°C. Therefore, in this example, if the 100 kHz ESR [mΩ] of the "hybrid capacitor element" after 500 hours at 150°C, measured by the above-mentioned method, is 20 mΩ or less, or if the ESR change rate (R / R0) is 1.70 or less, the "hybrid capacitor is capable of maintaining low ESR characteristics for a long time." Furthermore, if the 120 Hz capacitance [μF] of the "hybrid capacitor element" after 500 hours at 150°C, measured by the above-mentioned method, is 100 μF or more, the "hybrid capacitor is capable of maintaining high capacitance for a long time."

[0173] [Test for elution of conductive polymer film into ethylene glycol] 0.1 ml of the conductive polymer composition prepared in the Examples described later was applied to a 10 mm square alkali-free glass plate, heated on a hot plate in the atmosphere at 60° C. for 30 minutes, and then heated at 150° C. for 30 minutes to obtain a conductive polymer film. The obtained film was immersed in ethylene glycol, heated in an oven at 150° C. for 1 hour, removed, and visually inspected for the presence or absence of elution of the conductive polymer film into ethylene glycol.

[0174] If the ethylene glycol exhibits the black or blue color derived from PEDOT-MPS, it indicates that the conductive polymer film has eluted. Such a conductive polymer film has poor (poor) ethylene glycol resistance.

[0175] If the ethylene glycol remains colorless after heating, this indicates that the conductive polymer film has not been eluted. Such a conductive polymer film has excellent (good) resistance to ethylene glycol.

[0176] Synthesis Example 1 An aqueous solution of poly(3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-methyl-1-propanesulfonic acid) (hereinafter referred to as "PEDOT-MPS") was prepared in accordance with Synthesis Examples 1 and 2 of a known document (JP 2019-196443 A). PEDOT-MPS is a polymer containing structural units represented by the following formulas (5) and (6), and corresponds to polythiophene (A) in one embodiment of the present invention. The concentration of polythiophene (A) contained in this aqueous solution was 0.74 mass%. The aqueous solution also contained iron ions and sodium ions in amounts of 44 ppm and 12 ppm (relative to the polymer), respectively. The conductivity of the PEDOT-MPS was 342 S / cm.

[0177]

[0178] Example 1 (Preparation of Conductive Polymer Composition) The aqueous solution of PEDOT-MPS obtained in Synthesis Example 1 was dehydrated under reduced pressure to prepare an aqueous solution containing 2.10% by weight of PEDOT-MPS. To 9.524 g of the aqueous solution containing 2.10% by weight of PEDOT-MPS, 5.00 g of a 0.4% aqueous dispersion of single-walled carbon nanotubes (WPC-040 manufactured by Kusumoto Chemicals), 2.0 g of polyglycerin (Polyglycerin #310 manufactured by Sakamoto Pharmaceuticals), 1.8 g of sorbitol, and 1.68 g of water were added and mixed with stirring. Next, 0.06 g of 2-amino-2-hydroxymethyl-1,3-propanediol was added to the resulting mixture and mixed with stirring to obtain a conductive polymer composition with a pH of 3. The amount of 2-amino-2-hydroxymethyl-1,3-propanediol was 0.3 parts by weight per part by weight of PEDOT-MPS. Using the conductive polymer composition, a solid electrolytic capacitor element and a hybrid capacitor element were produced according to the method described above, and the characteristics were evaluated. The evaluation results are shown in Table 2 or Table 3.

[0179] Example 2: 9.524 g of the aqueous solution containing 2.10% by weight of PEDOT-MPS was mixed with 5.00 g of a 0.4% aqueous dispersion of single-walled carbon nanotubes (WPC-040, manufactured by Kusumoto Chemicals), 1.33 g of a 45% aqueous polyacrylic acid solution (Aqualic HL415, manufactured by Nippon Shokubai), 2.0 g of polyglycerin (Polyglycerin #310, manufactured by Sakamoto Yakuhin), 1.8 g of sorbitol, and 0.343 g of water, and the mixture was stirred. Next, 0.06 g of 2-amino-2-hydroxymethyl-1,3-propanediol was added to the resulting mixture and mixed with stirring, resulting in a conductive polymer composition with a pH of 3. The ratio of 2-amino-2-hydroxymethyl-1,3-propanediol was 0.3 parts by weight per part by weight of PEDOT-MPS. Using the conductive polymer composition, solid electrolytic capacitor elements and hybrid capacitor elements were fabricated according to the methods described above, and their characteristics were evaluated. The evaluation results are shown in Table 2 or Table 3.

[0180] Example 3: 0.02 g of single-walled carbon nanotubes (Tokyo Chemical Industry Co., Ltd.), 2.0 g of polyglycerin (Polyglycerin #310, Sakamoto Pharmaceutical Co., Ltd.), 1.8 g of sorbitol, and 6.656 g of water were added to 9.524 g of the aqueous solution containing 2.10% by mass of PEDOT-MPS and mixed with stirring. Next, 0.06 g of 2-amino-2-hydroxymethyl-1,3-propanediol was added to the resulting mixture and mixed with stirring to obtain a conductive polymer composition with a pH of 3. The ratio of 2-amino-2-hydroxymethyl-1,3-propanediol was 0.3 parts by mass per part by mass of PEDOT-MPS. Using the conductive polymer composition, solid electrolytic capacitor elements and hybrid capacitor elements were fabricated according to the methods described above, and their characteristics were evaluated. The evaluation results are shown in Table 2 or Table 3.

[0181] Example 4: 0.02 g of single-walled carbon nanotubes (Tokyo Chemical Industry Co., Ltd.), 1.33 g of a 45% aqueous solution of polyacrylic acid (Aqualic HL415, Nippon Shokubai Co., Ltd.), 2.0 g of polyglycerin (Polyglycerin #310, Sakamoto Yakuhin Co., Ltd.), 1.8 g of sorbitol, and 5.323 g of water were added and mixed by stirring. Next, 0.06 g of 2-amino-2-hydroxymethyl-1,3-propanediol was added to the resulting mixture and mixed by stirring, resulting in a conductive polymer composition with a pH of 3. The ratio of 2-amino-2-hydroxymethyl-1,3-propanediol was 0.3 parts by mass per part by mass of PEDOT-MPS. Using the conductive polymer composition, solid electrolytic capacitor elements and hybrid capacitor elements were fabricated according to the methods described above, and their characteristics were evaluated. The evaluation results are shown in Table 2 or Table 3.

[0182] Example 5: 0.02 g of multi-walled carbon nanotubes (Tokyo Chemical Industry Co., Ltd.), 2.0 g of polyglycerin (Polyglycerin #310, Sakamoto Pharmaceutical Co., Ltd.), 1.8 g of sorbitol, and 6.656 g of water were added to 9.524 g of the aqueous solution containing 2.10% by mass of PEDOT-MPS and mixed with stirring. Next, 0.06 g of 2-amino-2-hydroxymethyl-1,3-propanediol was added to the resulting mixture and mixed with stirring to obtain a conductive polymer composition with a pH of 3. The ratio of 2-amino-2-hydroxymethyl-1,3-propanediol was 0.3 parts by mass per part by mass of PEDOT-MPS. Using the conductive polymer composition, solid electrolytic capacitor elements and hybrid capacitor elements were fabricated according to the methods described above, and their characteristics were evaluated. The evaluation results are shown in Table 2 or Table 3.

[0183] Example 6: 9.524 g of the aqueous solution containing 2.10% by weight of PEDOT-MPS was mixed with 5.00 g of a 0.4% aqueous dispersion of single-walled carbon nanotubes (WPC-040, manufactured by Kusumoto Chemicals), 1.33 g of a 45% aqueous polyacrylic acid solution (Aqualic HL415, manufactured by Nippon Shokubai), 2.0 g of polyglycerin (Polyglycerin #310, manufactured by Sakamoto Yakuhin), 1.8 g of sorbitol, and 0.343 g of water, and the mixture was stirred. Next, 0.06 g of monoethanolamine was added to the resulting mixture and mixed with stirring, resulting in a conductive polymer composition with a pH of 3. The monoethanolamine content was 0.3 parts by weight per part by weight of PEDOT-MPS. Using the conductive polymer composition, solid electrolytic capacitor elements and hybrid capacitor elements were fabricated according to the methods described above, and their characteristics were evaluated. The evaluation results are shown in Table 2 or Table 3.

[0184] Example 7: 5.00 g of a 0.4% aqueous dispersion of single-walled carbon nanotubes (WPC-040, manufactured by Kusumoto Chemicals), 2.0 g of polyglycerin (Polyglycerin #310, manufactured by Sakamoto Pharmaceuticals), 1.8 g of mannitol, and 1.68 g of water were added to 9.524 g of the aqueous solution containing 2.10% by weight of PEDOT-MPS and mixed with stirring. Next, 0.06 g of 2-amino-2-hydroxymethyl-1,3-propanediol was added to the resulting mixture and mixed with stirring to obtain a conductive polymer composition with a pH of 3. The ratio of 2-amino-2-hydroxymethyl-1,3-propanediol was 0.3 parts by weight per part by weight of PEDOT-MPS. Using the conductive polymer composition, solid electrolytic capacitor elements and hybrid capacitor elements were fabricated according to the methods described above, and their characteristics were evaluated. The evaluation results are shown in Table 2 or Table 3.

[0185] Example 8: 9.524 g of the aqueous solution containing 2.10% by weight of PEDOT-MPS was mixed with 0.02 g of single-walled carbon nanotubes (Tokyo Chemical Industry Co., Ltd.), 5.00 g of a 1.2% PEDOT:PSS aqueous dispersion, 2.0 g of polyglycerin (Polyglycerin #310, Sakamoto Pharmaceutical Co., Ltd.), 1.8 g of sorbitol, and 1.656 g of water, and the mixture was stirred. Next, 0.03 g of 2-amino-2-hydroxymethyl-1,3-propanediol was added to the resulting mixture and mixed with stirring, resulting in a conductive polymer composition with a pH of 3. The ratio of 2-amino-2-hydroxymethyl-1,3-propanediol was 0.3 parts by weight per part by weight of PEDOT-MPS. Using the conductive polymer composition, solid electrolytic capacitor elements and hybrid capacitor elements were fabricated according to the methods described above, and their characteristics were evaluated. The evaluation results are shown in Table 2 or Table 3.

[0186] Example 9: To 9.524 g of the aqueous solution containing 2.10% by weight of PEDOT-MPS, 0.02 g of single-walled carbon nanotubes (manufactured by Tokyo Chemical Industry Co., Ltd.), 5.00 g of a 1.2% PEDOT:PSS aqueous dispersion, 1.33 g of a 45% aqueous polyacrylic acid solution (Aqualic HL415 manufactured by Nippon Shokubai Co., Ltd.), 2.0 g of polyglycerin (Polyglycerin #310 manufactured by Sakamoto Yakuhin Co., Ltd.), 1.8 g of sorbitol, and 0.323 g of water were added and mixed with stirring. Next, 0.03 g of 2-amino-2-hydroxymethyl-1,3-propanediol was added to the resulting mixture and mixed with stirring to obtain a conductive polymer composition with a pH of 3. The amount of 2-amino-2-hydroxymethyl-1,3-propanediol was 0.3 parts by weight per part by weight of PEDOT-MPS. Using the conductive polymer composition, a solid electrolytic capacitor element and a hybrid capacitor element were produced according to the method described above, and the characteristics were evaluated. The evaluation results are shown in Table 2 or Table 3.

[0187] Example 10: 9.524 g of the aqueous solution containing 2.10% by weight of PEDOT-MPS was mixed with 0.02 g of single-walled carbon nanotubes (Tokyo Chemical Industry Co., Ltd.), 5.00 g of a 1.2% PEDOT:PSS aqueous dispersion, 1.33 g of a 45% aqueous polyacrylic acid solution (Aqualic HL415, Nippon Shokubai Co., Ltd.), 2.0 g of polyglycerin (Polyglycerin #310, Sakamoto Yakuhin Co., Ltd.), and 2.123 g of water, and the mixture was stirred. Next, 0.03 g of 2-amino-2-hydroxymethyl-1,3-propanediol was added to the resulting mixture and stirred, resulting in a conductive polymer composition with a pH of 3. The ratio of 2-amino-2-hydroxymethyl-1,3-propanediol was 0.3 parts by weight per part by weight of PEDOT-MPS. Using the conductive polymer composition, solid electrolytic capacitor elements and hybrid capacitor elements were fabricated according to the methods described above, and their characteristics were evaluated. The evaluation results are shown in Table 2 or Table 3.

[0188] Example 11: 0.02 g of single-walled carbon nanotubes (Tokyo Chemical Industry Co., Ltd.), 5.00 g of a 1.2% PEDOT:PSS aqueous dispersion, 1.33 g of a 45% polyacrylic acid aqueous solution (Nippon Shokubai Co., Ltd., AQUALIC HL415), 4.0 g of sorbitol, and 0.123 g of water were added to 9.524 g of the aqueous solution containing 2.10% by weight of PEDOT-MPS, and the mixture was stirred and mixed. Next, 0.03 g of 2-amino-2-hydroxymethyl-1,3-propanediol was added to the resulting mixture and stirred, resulting in a conductive polymer composition with a pH of 3. The ratio of 2-amino-2-hydroxymethyl-1,3-propanediol was 0.3 parts by weight per part by weight of PEDOT-MPS. Using the conductive polymer composition, solid electrolytic capacitor elements and hybrid capacitor elements were fabricated according to the methods described above, and their characteristics were evaluated. The evaluation results are shown in Table 2 or Table 3.

[0189] Example 12: 0.02 g of single-walled carbon nanotubes (Tokyo Chemical Industry Co., Ltd.), 5.00 g of a 1.2% PEDOT:PSS aqueous dispersion, 1.33 g of a 45% polyacrylic acid aqueous solution (Nippon Shokubai Co., Ltd., AQUALIC HL415), 2.0 g of sorbitol, 2.0 g of mannitol, and 0.123 g of water were added to 9.524 g of the aqueous solution containing 2.10% by weight of PEDOT-MPS, and the mixture was stirred and mixed. Next, 0.03 g of 2-amino-2-hydroxymethyl-1,3-propanediol was added to the resulting mixture and stirred, resulting in a conductive polymer composition with a pH of 3. The ratio of 2-amino-2-hydroxymethyl-1,3-propanediol was 0.3 parts by weight per part by weight of PEDOT-MPS. Using the conductive polymer composition, solid electrolytic capacitor elements and hybrid capacitor elements were fabricated according to the methods described above, and their characteristics were evaluated. The evaluation results are shown in Table 2 or Table 3.

[0190] Using the conductive polymer composition obtained in Example 2, a conductive polymer film was produced according to the method described above in "Test for elution of conductive polymer film into ethylene glycol," and a test for elution into ethylene glycol was carried out. The evaluation results are shown in Table 4.

[0191] Using the conductive polymer composition obtained in Example 9, a conductive polymer film was produced according to the method described above in "Test for elution of conductive polymer film into ethylene glycol," and a test for elution into ethylene glycol was carried out. The evaluation results are shown in Table 4.

[0192] Comparative Example 1: 10.476 g of water was added to 9.524 g of the aqueous solution containing 2.10% by mass of PEDOT-MPS, and the mixture was stirred and mixed. Next, 0.3 g of 2-amino-2-hydroxymethyl-1,3-propanediol was added to the resulting mixture and stirred and mixed, yielding a conductive polymer composition with a pH of 3. The amount of 2-amino-2-hydroxymethyl-1,3-propanediol was 0.3 parts by mass per part by mass of PEDOT-MPS. Solid electrolytic capacitor elements and hybrid capacitor elements were fabricated using the conductive polymer composition according to the methods described above, and their characteristics were evaluated. The evaluation results are shown in Table 2 or Table 3.

[0193] Comparative Example 2: 5.00 g of a 1.2% PEDOT:PSS aqueous dispersion, 1.8 g of sorbitol, and 8.438 g of water were added to 9.524 g of the aqueous solution containing 2.10% by weight of PEDOT-MPS, and the mixture was stirred and mixed. Next, 0.03 g of 2-amino-2-hydroxymethyl-1,3-propanediol was added to the resulting mixture and stirred, resulting in a conductive polymer composition with a pH of 3. The amount of 2-amino-2-hydroxymethyl-1,3-propanediol was 0.3 parts by weight per part by weight of PEDOT-MPS. Using the conductive polymer composition, solid electrolytic capacitor elements and hybrid capacitor elements were fabricated according to the methods described above, and their characteristics were evaluated. The evaluation results are shown in Table 2 or Table 3.

[0194] Comparative Example 3: 0.02 g of single-walled carbon nanotubes (Tokyo Chemical Industry Co., Ltd.), 5.00 g of a 1.2% PEDOT:PSS aqueous dispersion, 1.33 g of a 45% polyacrylic acid aqueous solution (Aqualic HL415, Nippon Shokubai Co., Ltd.), and 4.123 g of water were added to 9.524 g of the aqueous solution containing 2.10% by weight of PEDOT-MPS, and the mixture was stirred and mixed. Next, 0.03 g of 2-amino-2-hydroxymethyl-1,3-propanediol was added to the resulting mixture and stirred, resulting in a conductive polymer composition with a pH of 3. The amount of 2-amino-2-hydroxymethyl-1,3-propanediol was 0.3 parts by weight per part by weight of PEDOT-MPS. Using the conductive polymer composition, solid electrolytic capacitor elements and hybrid capacitor elements were fabricated according to the methods described above, and their characteristics were evaluated. The evaluation results are shown in Table 2 or Table 3.

[0195] Comparative Example 4 1.67 g of water was added to 8.33 g of a 1.2 mass % PEDOT:PSS (corresponding to conductive polymer (F)) aqueous dispersion, and the mixture was stirred and mixed. Next, 0.03 g of 2-amino-2-hydroxymethyl-1,3-propanediol was added to the resulting mixture, and the mixture was stirred and mixed to obtain a conductive polymer aqueous dispersion with a pH of 3. The amount of 2-amino-2-hydroxymethyl-1,3-propanediol was 0.3 parts by mass per part by mass of PEDOT:PSS. Solid electrolytic capacitor elements and hybrid capacitor elements were produced using the conductive polymer aqueous dispersion according to the methods described above, and their characteristics were evaluated. The evaluation results are shown in Table 2 or Table 3.

[0196] Comparative Example 5: 5.00 g of a 0.4% aqueous dispersion of single-walled carbon nanotubes (WPC-040 manufactured by Kusumoto Chemicals) and 1.67 g of water were added to 13.33 g of a 1.2 mass % aqueous dispersion of PEDOT:PSS (corresponding to conductive polymer (F)), and the mixture was stirred and mixed. The resulting mixture coagulated, making it impossible to prepare a solid electrolytic capacitor.

[0197] Comparative Example 6 A conductive polymer film was prepared using the conductive polymer composition obtained in Comparative Example 2 according to the method described above in "Test for elution of conductive polymer film into ethylene glycol," and an elution test into ethylene glycol was carried out. The evaluation results are shown in Table 4.

[0198] Table 1 shows the compositions of Examples 1 to 12 and Comparative Examples 1 to 5.

[0199]

[0200]

[0201]

[0202]

[0203] The results shown in Table 2 demonstrate that Examples 1 to 12 have the effect of providing solid electrolytic capacitors that have high capacitance and low ESR characteristics.

[0204] In Comparative Examples 1 to 4, it was not possible to achieve both high capacitance and low ESR characteristics for the solid electrolytic capacitors. In Comparative Example 5, aggregation occurred, making it impossible to produce a solid electrolytic capacitor.

[0205] Furthermore, the results shown in Table 3 show that Examples 1 to 12 have the effect of suppressing the decrease in capacitance and the increase in ESR of the hybrid capacitor after being left at 150°C for 500 hours.

[0206] Furthermore, from the results shown in Table 4, Examples 13 and 14 have the effect of providing a conductive polymer film that is suppressed from eluting into ethylene glycol, which is used as an electrolyte in hybrid capacitors.

[0207] One of the reasons for suppressing the increase in ESR during the heat resistance test in the above hybrid capacitor is the effect of suppressing the elution of the conductive polymer film into the electrolyte.

[0208] As described above, by using the conductive polymer composition of the present embodiment, it is possible to provide an electrolytic capacitor that has a higher capacity and a lower ESR characteristic than when a conventional conductive polymer composition is used.

Claims

1. A conductive polymer composition comprising: 0.01 to 10 mass% of polythiophene (A) containing at least one structural unit selected from the group consisting of structural units represented by the following general formula (1) and structural units represented by the following general formula (2); 0.001 to 10 mass% of nanostructured material (B); 1 to 50 mass% of at least one member (C) selected from the group consisting of polyglycerin and sugar alcohol; and a solvent. [In the above general formula (1), M ＋ represents a hydrogen ion. In the above general formulas (1) and (2), R represents an organic group having a total of 1 to 18 carbon atoms and having at least one substituent selected from the group consisting of a sulfonic acid group and a phosphonic acid group.] 2. The conductive polymer composition according to claim 1, wherein the nanostructured material (B) is at least one selected from the group consisting of cellulose nanofibers, single-walled carbon nanotubes, double-walled carbon nanotubes, and multi-walled carbon nanotubes.

3. The conductive polymer composition according to claim 1, wherein the nanostructured material (B) is a cellulose nanofiber or a single-walled carbon nanotube.

4. The conductive polymer composition according to claim 1, wherein the sugar alcohol is sorbitol, mannitol, erythritol, xylitol, or lactitol.

5. The conductive polymer composition according to claim 1, further comprising 0.001 to 20% by mass of poly(meth)acrylic acid (D).

6. The conductive polymer composition according to claim 1, further comprising 0.001 to 20 mass % of a compound (E) capable of forming an ion pair with the sulfonic acid group or phosphonic acid group of the polythiophene (A).

7. The conductive polymer composition according to claim 1, wherein the content of the nanostructured material (B) is 0.01 to 5 parts by mass per part by mass of the polythiophene (A).

8. The conductive polymer composition according to claim 1, wherein the content of the at least one member (C) selected from the group consisting of polyglycerin and sugar alcohols is 3 to 50 parts by mass per part by mass of the polythiophene (A).

9. The conductive polymer composition according to claim 5, wherein the content of the poly(meth)acrylic acid (D) is 0.1 to 10 parts by mass per part by mass of the polythiophene (A).

10. The conductive polymer composition according to claim 1, further comprising a conductive polymer (F) which is a complex of a polyanion and a poly(3,4-ethylenedioxythiophene derivative) containing a structural unit represented by the following general formula (3), wherein the content of the conductive polymer (F) is 0.001 to 20 parts by mass per part by mass of the polythiophene (A): [In the formula, R ３ represents a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 6 carbon atoms, a substituted alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a substituted alkoxy group having 1 to 6 carbon atoms.] 11. R ３ The conductive polymer composition according to claim 10 , wherein is a hydrogen atom.

12. The conductive polymer composition according to claim 10, wherein the conductive polymer (F) is PEDOT:PSS.

13. A method for producing an electrolytic capacitor, comprising the steps of covering the surface of the dielectric oxide film of an anode body on which the dielectric oxide film has been formed with the conductive polymer composition according to any one of claims 1 to 12, and then heating and drying the composition.

14. A method for producing an electrolytic capacitor, comprising the steps of covering the surface of the dielectric oxide film of an anode body on which the dielectric oxide film has been formed with the conductive polymer composition according to any one of claims 1 to 12, and then heating and drying the film, and further impregnating the film with an electrolytic solution and again heating and drying the film.