Conductive polymer dispersion, capacitor and method for manufacturing the same, and conductive laminate and method for manufacturing the same

Abstract

This invention provides a conductive polymer dispersion suitable for the manufacture of high-performance capacitors. [Solution] A conductive polymer dispersion containing a conductive composite comprising a π-conjugated conductive polymer and a polyanion, a polyethyleneimine derivative, at least one of a nitrogen-containing aromatic cyclic compound and a tertiary amine, and a dispersion medium, wherein at least some of the hydrogen atoms bonded to the nitrogen atom constituting polyethyleneimine are of the chemical formula -(CH2CH2O) n -R 1 A conductive polymer dispersion substituted with a group represented by .

Description

Technical Field

[0001] The present invention relates to a conductive polymer dispersion containing a π-conjugated conductive polymer and a polyanion, a capacitor and a method for producing the same, and a conductive laminate and a method for producing the same.

Background Art

[0002] A π-conjugated conductive polymer whose main chain is composed of a π-conjugated system forms a conductive composite by doping with a polyanion having an anion group, and exhibits dispersibility in water. A method for manufacturing a capacitor is disclosed, in which a paint containing a conductive polymer dispersion containing a conductive composite is applied to a dielectric layer provided on the surface of an anode made of valve metal, dried to form a solid electrolyte layer, and a cathode is disposed opposite thereto (for example, Patent Document 1). According to this disclosure, the performance of the capacitor is improved by containing a specific unsaturated aliphatic alcohol compound in the paint.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] As the performance of a capacitor provided with a solid electrolyte layer, one or more of a high capacitance, a low equivalent series resistance (ESR), a small leakage current, and excellent heat resistance are required.

[0005] The present invention provides a conductive polymer dispersion suitable for manufacturing a high-performance capacitor, and a capacitor and a method for producing the same using the same.

Means for Solving the Problems

[0006] [1] A conductive polymer dispersion comprising a conductive composite containing a π-conjugated conductive polymer and a polyanion, a polyethyleneimine derivative, at least one of a nitrogen-containing aromatic cyclic compound and a tertiary amine, and a dispersion medium, wherein the polyethyleneimine derivative has more than 80% of the hydrogen atoms bonded to the nitrogen atoms constituting polyethyleneimine substituted by a group represented by formula (1) described below. [2] The conductive polymer dispersion according to [1], wherein the polyethyleneimine derivative has a molecular weight of 10,000 or more and 200,000 or less. [3] The conductive polymer dispersion according to [1] or [2], wherein the content of the polyethyleneimine derivative is 1 part by mass or more and 50 parts by mass or less per 100 parts by mass of the conductive composite. [4] A conductive polymer dispersion according to any one of [1] to [3], wherein the water content is 60% by mass or more relative to the total mass of the dispersion medium. [5] A conductive polymer dispersion according to any one of [1] to [4], wherein the pH at a temperature of 25°C is 3.0 or higher and less than 7.0. [6] A conductive polymer dispersion according to any one of [1] to [5], wherein the π-conjugated conductive polymer is poly(3,4-ethylenedioxythiophene), or the polyanion is polystyrene sulfonic acid, or the π-conjugated conductive polymer is poly(3,4-ethylenedioxythiophene) and the polyanion is polystyrene sulfonic acid. [7] A capacitor comprising an anode made of a porous body of valve metal, a dielectric layer made of an oxide of the valve metal, a cathode made of a conductive material provided on the side of the dielectric layer opposite to the anode, and a solid electrolyte layer formed between the dielectric layer and the cathode, wherein the solid electrolyte layer is a cured product of a conductive polymer dispersion according to any one of [1] to [6]. [8] A method for manufacturing a capacitor, comprising the step of applying a conductive polymer dispersion according to any one of [1] to [6] to the surface of a dielectric layer formed on the surface of an anode made of a porous valve metal, and drying it to form a solid electrolyte layer. [9] A conductive laminate comprising a substrate and a conductive layer formed on at least a portion of the surface of the substrate, wherein the conductive layer is a cured product of a conductive polymer dispersion according to any one of [1] to [6].

[10] A method for producing a conductive laminate, comprising the step of applying a conductive polymer dispersion according to any one of [1] to [6] to the surface of at least a portion of a substrate and drying it to form a conductive layer. [Effects of the Invention]

[0007] The conductive polymer dispersion of the present invention contains a specific polyethyleneimine derivative, which allows for the formation of a solid electrolyte layer with excellent conductive properties on an anode made of a porous valve metal. This property makes it suitable not only for the manufacture of capacitors but also for the manufacture of conductive laminates in which a conductive layer is laminated on a substrate.

[0008] This invention is believed to contribute to SDG Goal 12, "Responsible Consumption and Production."

[0009] In this specification and the claims, the lower and upper limits of the numerical ranges indicated by "~" are to be included within those numerical ranges. [Brief explanation of the drawing]

[0010] [Figure 1] This is a cross-sectional view showing one embodiment of a capacitor. [Modes for carrying out the invention]

[0011] <<Conductive polymer dispersion>> A conductive polymer dispersion according to a first aspect of the present invention contains a conductive composite comprising a π-conjugated conductive polymer and a polyanion, a polyethyleneimine derivative, at least one of a nitrogen-containing aromatic cyclic compound and a tertiary amine, and a dispersion medium.

[0012] <Conductive composite> The conductive composite according to this embodiment comprises a π-conjugated conductive polymer and a polyanion. The polyanion in the conductive composite dops the π-conjugated conductive polymer to form a conductive composite. In the polyanion, only some of the anionic groups dopate the π-conjugated conductive polymer, and there are excess anionic groups that do not participate in doping. Since the excess anionic groups are hydrophilic groups, the conductive composite is water-dispersible.

[0013] (π-conjugated conductive polymers) Any organic polymer whose main chain is composed of a π-conjugated system can be used as the π-conjugated conductive polymer. Examples include polypyrrole-based conductive polymers, polythiophene-based conductive polymers, polyacetylene-based conductive polymers, polyphenylene-based conductive polymers, polyphenylene-vinylene-based conductive polymers, polyaniline-based conductive polymers, polyacene-based conductive polymers, polythiophene-vinylene-based conductive polymers, and copolymers thereof. From the viewpoint of stability in air, polypyrrole-based conductive polymers, polythiophenes, and polyaniline-based conductive polymers are preferred, and from the viewpoint of transparency, polythiophene-based conductive polymers are more preferred.

[0014] Examples of polythiophene-based conductive polymers include polythiophene, poly(3-methylthiophene), poly(3-ethylthiophene), poly(3-propylthiophene), poly(3-butylthiophene), poly(3-hexylthiophene), poly(3-heptylthiophene), poly(3-octylthiophene), poly(3-decylthiophene), poly(3-dodecylthiophene), poly(3-octadecylthiophene), poly(3-bromothiophene), poly(3-chlorothiophene), and poly(3-iodine). Poly(3-Cyanothiophene), Poly(3-Phenylthiophene), Poly(3,4-Dimethylthiophene), Poly(3,4-Dibutylthiophene), Poly(3-Hydroxythiophene), Poly(3-Methoxythiophene), Poly(3-Ethoxythiophene), Poly(3-Butoxythiophene), Poly(3-Hexyloxythiophene), Poly(3-Heptyloxythiophene), Poly(3-Octyloxythiophene), Poly(3-Decyloxythiophene), Poly(3-Dodecyl Poly(3-octadecyloxythiophene), poly(3,4-dihydroxythiophene), poly(3,4-dimethoxythiophene), poly(3,4-diethoxythiophene), poly(3,4-dipropoxythiophene), poly(3,4-dibutoxythiophene), poly(3,4-dihexyloxythiophene), poly(3,4-diheptyloxythiophene), poly(3,4-dioctyloxythiophene), poly(3,4-didecyloxythiophene), poly(3,4-di Examples include dodecyloxythiophene, poly(3,4-ethylenedioxythiophene), poly(3,4-propylenedioxythiophene), poly(3,4-butylenedioxythiophene), poly(3-methyl-4-methoxythiophene), poly(3-methyl-4-ethoxythiophene), poly(3-carboxythiophene), poly(3-methyl-4-carboxythiophene), poly(3-methyl-4-carboxyethylthiophene), and poly(3-methyl-4-carboxybutylthiophene). Examples of polypyrrole-based conductive polymers include polypyrrole, poly(N-methylpyrrole), poly(3-methylpyrrole), poly(3-ethylpyrrole), poly(3-n-propylpyrrole), poly(3-butylpyrrole), poly(3-octylpyrrole), poly(3-decylpyrrole), poly(3-dodecylpyrrole), poly(3,4-dimethylpyrrole), poly(3,4-dibutylpyrrole), poly(3-carboxypyrrole), poly(3-methyl-4-carboxypyrrole), poly(3-methyl-4-carboxyethylpyrrole), poly(3-methyl-4-carboxybutylpyrrole), poly(3-hydroxypyrrole), poly(3-methoxypyrrole), poly(3-ethoxypyrrole), poly(3-butoxypyrrole), poly(3-hexyloxypyrrole), and poly(3-methyl-4-hexyloxypyrrole). Examples of polyaniline-based conductive polymers include polyaniline, poly(2-methylaniline), poly(3-isobutylaniline), poly(2-anilinesulfonic acid), and poly(3-anilinesulfonic acid). Among these π-conjugated conductive polymers, poly(3,4-ethylenedioxythiophene) is particularly preferred because of its excellent conductivity, transparency, and heat resistance. The π-conjugated conductive polymer contained in the conductive composite may be one type or two or more types.

[0015] (Polyanion) A polyanion is a polymer having two or more monomer units with anionic groups in the molecule. The anionic group of this polyanion functions as a dopant for the π-conjugated conductive polymer and improves the conductivity of the π-conjugated conductive polymer. The anionic group of the polyanion is preferably a sulfo group or a carboxy group. Specific examples of such polyanions include polystyrene sulfonic acid, polyvinyl sulfonic acid, polyallyl sulfonic acid, polyacrylate ester having a sulfo group, polymethacrylate ester having a sulfo group (for example, poly(4-sulfobutyl methacrylate), polysulfoethyl methacrylate, polymethacryloyloxybenzenesulfonic acid), poly(2-acrylamido-2-methylpropanesulfonic acid), polymers having a sulfo group such as polyisoprene sulfonic acid, and polymers having a carboxy group such as polyvinyl carboxylic acid, polystyrene carboxylic acid, polyallyl carboxylic acid, polyacrylic acid, polymethacrylic acid, poly(2-acrylamido-2-methylpropane carboxylic acid), polyisoprene carboxylic acid. The polyanion may be a homopolymer in which a single monomer is polymerized, or a copolymer in which two or more monomers are polymerized. Among these polyanions, polymers having a sulfo group are preferred, and polystyrene sulfonic acid is more preferred, because the conductivity can be made higher.

[0016] The weight average molecular weight Mw of the polyanion is not particularly limited. For example, it is preferably from 10,000 to 1,000,000, more preferably from 50,000 to 800,000, and even more preferably from 100,000 to 600,000. When the weight average molecular weight Mw of the polyanion is within the above range, the viscosity of the conductive polymer dispersion of the present embodiment becomes appropriately low, and a capacitor with a low ESR can be easily manufactured. The weight average molecular weight Mw of the polyanion is the average molecular weight on a mass basis measured by gel filtration chromatography and determined in terms of pullulan.

[0017] The polyanion content in the conductive polymer dispersion of this embodiment is preferably in the range of 1 to 1000 parts by mass, more preferably 10 to 700 parts by mass, and even more preferably 100 to 500 parts by mass, per 100 parts by mass of the π-conjugated conductive polymer. If the polyanion content is above the lower limit, the doping effect on the π-conjugated conductive polymer tends to be stronger, resulting in higher conductivity. On the other hand, if the polyanion content is below the upper limit, the π-conjugated conductive polymer can be sufficiently contained, thus ensuring sufficient conductivity.

[0018] In the conductive polymer dispersion of this embodiment, the content of the conductive composite is preferably 0.1 parts by mass or more and 3.0 parts by mass or less, more preferably 0.5 parts by mass or more and 2.5 parts by mass or less, even more preferably 1.0 part by mass or more and 2.3 parts by mass or less, and most preferably 1.3 parts by mass or more and 2.0 parts by mass or less, based on 100 parts by mass of the total of the conductive composite (total of π-conjugated conductive polymer and polyanion) and water. If the value is above the lower limit of the above range, the conductivity of the cured product of the conductive polymer dispersion will be further increased. If the value is below the upper limit of the above range, the viscosity of the conductive polymer dispersion can be reduced, and the dispersibility of the conductive composite can be further improved.

[0019] The content of the conductive composite (total content of π-conjugated conductive polymer and polyanion) relative to the total mass of the conductive polymer dispersion in this embodiment is preferably, for example, 0.1% by mass or more and 3.0% by mass or less, more preferably 0.5% by mass or more and 2.5% by mass or less, and even more preferably 1.0% by mass or more and 2.0% by mass or less. If the value is above the lower limit of the above range, the conductivity of the cured product of the conductive polymer dispersion will be further increased. If the value is below the upper limit of the above range, the viscosity of the conductive polymer dispersion can be reduced, and the dispersibility of the conductive composite can be further improved.

[0020] <Polyethyleneimine derivative> The conductive polymer dispersion of this embodiment contains a specific polyethyleneimine derivative, thereby improving capacitor performance. Although the details of this mechanism are not yet fully understood, it is presumed that one of the contributing factors is the electrostatic interaction between the nitrogen atoms constituting the repeating units (-CH2CH2NH-) of the polyethyleneimine main chain and the conductive composite, as these atoms have lone pairs of electrons. Furthermore, in the polyethyleneimine derivative used in this embodiment, at least some of the hydrogen atoms bonded to the nitrogen atoms of polyethyleneimine are substituted by a group represented by formula (1). This substituent is a hydrophilic group also known as the repeating unit of polyethylene glycol, and is thought to improve the dispersibility of the conductive composite in the dispersion and enhance wettability to the substrate.

[0021] In this embodiment, the polyethyleneimine derivative has a hydrogen atom bonded to the nitrogen atom constituting polyethyleneimine that is replaced by a group represented by formula (1). The nitrogen atom may be a nitrogen atom constituting the main chain of polyethyleneimine, or a nitrogen atom constituting the terminal amino group of polyethyleneimine.

[0022] The substituent represented by formula (1) can be formed by ethoxylation (sometimes called ethoxylation) of polyethyleneimine. Ethoxylation can be carried out by known methods, such as a reaction with ethylene oxide. It is preferable that more than 80%, 85% or more, or 90% or more of the nitrogen atoms of polyethyleneimine have substituents of formula (1). Within this range, the dispersibility of each component contained in the conductive polymer dispersion of this embodiment is increased, making it easier to manufacture capacitors.

[0023] [ka] [In equation (1), n ​​represents a natural number, R 1 [This represents a hydrogen atom or any monovalent organic group.]

[0024] In formula (1), R 1While a hydrogen atom is acceptable, any monovalent organic group may be added to the terminal hydroxyl group, as long as it does not impair the effects of the present invention. The lower limit of n is 1, and from the viewpoint of improving hydrophilicity, values ​​of 3 or higher, 5 or higher, 7 or higher, or 9 or higher are preferred. The upper limit of n is not particularly limited and can be adjusted by referring to the degree of polymerization and physical properties of polyethylene glycol that are generally known, for example, it can be 1000 or less, 500 or less, 100 or less, 50 or less, or 20 or less.

[0025] The polyethyleneimine that forms the base of the polyethyleneimine derivative may be linear, branched, or dendritic. From the viewpoint of improving the dispersibility of polyethyleneimine in the dispersion medium, it is preferable to be branched or dendritic, but since the polyethyleneimine derivative of this embodiment has improved hydrophilicity due to the substituent of formula (1), it may also be linear. It is known that the degree of branching can be adjusted by the acid concentration and temperature during the synthesis of polyethyleneimine. The degree of branching of the polyethyleneimine that forms the base of the polyethyleneimine derivative of this embodiment is not particularly limited.

[0026] The molecular weight of polyethyleneimine, which forms the base of the polyethyleneimine derivative, is known to be widely adjustable, for example, from 500 to 200,000. The molecular weight of the polyethyleneimine derivative in this embodiment is not particularly limited, and from the viewpoint of dispersibility in the dispersion medium and ease of interaction with the conductive composite, it is preferably, for example, 10,000 to 200,000, and may be further adjusted to the range of 10,000 to 100,000, 10,000 to 50,000, or 10,000 to 30,000. The molecular weight of polyethyleneimine derivatives can be measured by known methods.

[0027] The polyethyleneimine derivative used in this embodiment can be purchased commercially. Examples include PN-100 (molecular weight 13,000, specific gravity 1.128 g / mL (30℃)) manufactured by Nippon Shokubai Co., Ltd., and polyethyleneimine 80% ethoxylated solution (molecular weight 110,000, specific gravity 1.08 g / mL (25℃)) manufactured by Sigma-Aldrich.

[0028] The content of polyethyleneimine derivative in the conductive polymer dispersion of this embodiment is preferably 1 to 50 parts by mass, more preferably 3 to 40 parts by mass, and even more preferably 5 to 30 parts by mass, per 100 parts by mass of the conductive composite (total of π-conjugated conductive polymer and polyanion). If the value is above the lower limit of the above range, the effects of incorporating polyethyleneimine derivatives will be fully realized, resulting in improved capacitor performance. If the value is below the upper limit of the above range, the relative content of the conductive composite becomes sufficient, and as a result of the conductivity being fully expressed, the performance of the capacitor can be further improved.

[0029] The content of the polyethyleneimine derivative relative to the total mass of the conductive polymer dispersion in this embodiment can be, for example, 0.01% by mass or more and 1.0% by mass or less. Within the above range, it is possible to improve the dispersibility of the conductive composite while suppressing the increase in viscosity of the conductive polymer dispersion.

[0030] <Dispersion medium> The dispersion medium contained in the conductive polymer dispersion is preferably an aqueous dispersion medium containing water, given that the conductive composite is hydrophilic. However, a dispersion medium other than water may also be included. The dispersion medium other than water is not particularly limited, as long as it does not significantly impair the dispersibility of the conductive composite. Conductive composites have excess anionic groups derived from polyanions and exhibit high dispersibility in water; therefore, water-soluble organic solvents are preferred as dispersion media other than water. Here, water-soluble organic solvents are organic solvents whose solubility in 100g of water at 20°C is 1g or more, and examples include alcohol-based solvents, ketone-based solvents, and ester-based solvents. The dispersion media may consist of one or more water-soluble organic solvents. Non-water-soluble organic solvents are organic solvents whose solubility is less than 1g.

[0031] In this embodiment, the water content relative to the total mass of the dispersion medium is preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, and may even be 100% by mass, from the viewpoint of improving the dispersibility of the conductive composite and the dispersibility of the polyethyleneimine derivative.

[0032] The water content relative to the total mass of the conductive polymer dispersion in this embodiment is preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more, from the viewpoint of improving the dispersibility of the conductive composite and the polyethyleneimine derivative. Furthermore, from the viewpoint of obtaining room for components other than the dispersion medium, it is preferably 99% by mass or less. When water is included at or above the lower limit, the dispersibility of the conductive composite and polyethyleneimine derivative contained in the conductive polymer dispersion is improved, and the performance of the capacitor having a solid electrolyte layer formed from the conductive polymer dispersion can be further improved. In addition, the conductivity of the conductive layer formed from the conductive polymer dispersion can be further improved.

[0033] <Neutralizing agent> The conductive polymer dispersion of this embodiment may further contain one or more neutralizing agents. When the polyanion has an acidic group, the conductive polymer dispersion tends to become strongly acidic, but this can be neutralized by a neutralizing agent. Examples of neutralizing agents include basic compounds. Basic compounds function as Brønsted bases, accepting protons from the excess anionic groups of polyanions. To perform this function, the solubility of the basic compound in water is preferably 0.001 g or more per 100 g of water at 20°C. While there is no particular upper limit to the solubility, even a solubility of around 0.1 g is sufficient to perform the above function.

[0034] Examples of basic compounds that can be used include nitrogen-containing organic or inorganic basic compounds, alkali metal or group 2 metal hydroxides, and various carbonates and bicarbonates. Specific examples of alkali metal hydroxides include potassium hydroxide and sodium hydroxide. Specific examples of carbonates or bicarbonates include ammonium bicarbonate, ammonium carbonate, potassium bicarbonate, potassium carbonate, sodium bicarbonate, and sodium carbonate. Specific examples of quaternary ammonium hydroxides or their salts include tetramethylammonium hydroxide, tetraethylammonium hydroxide, and tetrabutylammonium hydroxide.

[0035] The conductive polymer dispersion of this embodiment preferably contains at least one of a nitrogen-containing aromatic cyclic compound and a tertiary amine as the basic compound.

[0036] Examples of nitrogen-containing aromatic cyclic compounds (aromatic compounds in which at least one nitrogen atom forms a ring structure) include pyrrole, indole, imidazole, 2-methylimidazole, 2-propylimidazole, N-methylimidazole, N-propylimidazole, N-butylimidazole, 1-(2-hydroxyethyl)imidazole, 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole, and 1-cyanoethyl-2-ethyl-4-methyl Examples of derivatives include imidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 1-acetylimidazole, 2-aminobenzimidazole, 2-amino-1-methylbenzimidazole, 2-hydroxybenzimidazole, 2-(2-pyridyl)benzimidazole, pyridine, pyrimidine, pyrazine, and their alkyl-substituted derivatives (e.g., derivatives with C1-C4 alkyl groups such as methyl, ethyl, propyl, and butyl), halogen-substituted derivatives (e.g., derivatives with halogen groups such as fluoro, chloro, and brom), and nitrile-substituted derivatives. Among these, imidazole is preferred. From the perspective of reducing the ESR of the capacitors being manufactured, nitrogen-containing aromatic cyclic compounds preferable.

[0037] Examples of tertiary amines include triethanolamine, trimethylamine, triethylamine, tripropylamine, tributylamine, trihexylamine, trioctylamine, triphenylamine, trynzylamine, and trinaphthylamine. From the viewpoint of reducing the leakage current of the capacitors being manufactured, tertiary amines are preferred.

[0038] The content of basic compounds in the conductive polymer dispersion is preferably, for example, 1 to 100 parts by mass, more preferably 10 to 70 parts by mass, and even more preferably 20 to 40 parts by mass, per 100 parts by mass of the conductive composite (total of π-conjugated conductive polymer and polyanion). Within the above preferred range, the acidity of the conductive polymer dispersion is reduced, the corrosiveness to the substrate is decreased, and the performance of the capacitor can be further improved.

[0039] The content of basic compounds in the conductive polymer dispersion is preferably such that the pH of the conductive polymer dispersion (at 25°C) is 3.0 or higher and less than 7.0, more preferably 5.0 or higher and 6.8 or lower, and even more preferably 5.5 to 6.5. Within the above preferred range, the acidity of the conductive polymer dispersion is reduced, the corrosiveness to the substrate is decreased, and the performance of the capacitor can be further improved.

[0040] <High boiling point solvents> The conductive polymer dispersion of this embodiment may further contain one or more organic solvents (high-boiling point solvents) having a boiling point of 150°C or higher at 1 atmosphere (101325 Pascals). Preferably, the boiling point is 250°C or lower. The inclusion of high-boiling point solvents provides effects such as improved conductivity of the cured product of the conductive polymer dispersion.

[0041] Examples of high-boiling point solvents include water-soluble organic solvents and water-insoluble organic solvents. Here, the definitions of water-soluble organic solvents and water-insoluble organic solvents are the same as described above.

[0042] Examples of high-boiling-point water-soluble organic solvents include alcohol-based solvents, ether-based solvents, ketone-based solvents, nitrogen-containing solvents, and sulfur-containing solvents. Examples of alcohol-based solvents include polyhydric alcohols such as ethylene glycol (boiling point 198°C), 1,2-propanediol (also known as propylene glycol, boiling point 188°C), 1,3-propanediol (boiling point 214°C), 1,2-butanediol (boiling point 194°C), 1,3-butanediol (boiling point 207°C), 1,4-butanediol (boiling point 228°C), dipropylene glycol (boiling point 232°C, a mixture of isomers), and diethylene glycol (boiling point 245°C). Examples of ether-based solvents include diethylene glycol dimethyl ether (boiling point 162°C) and diethylene glycol diethyl ether (boiling point 188°C). Examples of ketone-based solvents include methyl amyl ketone (boiling point 151°C) and diacetone alcohol (boiling point 168°C). Examples of nitrogen atom-containing solvents include N-methylpyrrolidone (boiling point 202°C), N-methylacetamide (boiling point 206°C), dimethylacetamide (boiling point 165°C), and N,N-dimethylformamide (boiling point 153°C). Examples of sulfur atom-containing solvents include dimethyl sulfoxide (boiling point 189°C).

[0043] Examples of high-boiling-point, water-insoluble organic solvents include hydrocarbon solvents. Examples of hydrocarbon solvents include aliphatic hydrocarbon solvents and aromatic hydrocarbon solvents. Examples of aliphatic hydrocarbon solvents include nonane (boiling point 151°C), decane (boiling point 174°C), and dodecane (boiling point 216°C). Examples of aromatic hydrocarbon solvents include propylbenzene (boiling point 159°C) and isopropylbenzene (boiling point 152°C).

[0044] Among the examples above, alcohol-based high-boiling point solvents are preferred because they provide an even greater effect in improving conductivity. Among alcohol-based high-boiling point solvents, ethylene glycol (boiling point 198°C), 1,2-propanediol (boiling point 188°C), 1,3-propanediol (boiling point 214°C), diethylene glycol (boiling point 245°C), and dimethyl sulfoxide (boiling point 189°C) are preferred because they exhibit superior effects such as improved conductivity.

[0045] The content of the high-boiling point solvent in the conductive polymer dispersion is preferably, for example, 10 parts by mass or more and 2000 parts by mass or less, more preferably 100 parts by mass or more and 1000 parts by mass or less, and even more preferably 400 parts by mass or more and 800 parts by mass or less, per 100 parts by mass of the conductive composite (total of π-conjugated conductive polymer and polyanion). Within the above range, the ESR of a capacitor having a solid electrolyte layer formed from a conductive polymer dispersion can be further reduced. Furthermore, the conductivity of the conductive layer formed from the conductive polymer dispersion can be further enhanced.

[0046] <Optional additives> The conductive polymer dispersion may contain other optional additives. The proportion of these additives can be appropriately determined depending on the type of additive, but for example, it can be 1 to 1000 parts by mass per 100 parts by mass of the total of the π-conjugated conductive polymer and polyanion. Here, the optional additives are compounds other than the basic compound, the high-boiling point solvent, the polyethyleneimine derivative, and the dispersion medium.

[0047] Optional additives include, for example, surfactants, inorganic conductive agents, defoamers, coupling agents, antioxidants, and UV absorbers. Examples of surfactants include nonionic, anionic, and cationic surfactants, but nonionic surfactants are preferred in terms of storage stability. Polymer-based surfactants such as polyvinyl alcohol may also be added. Examples of inorganic conductive agents include metal ions and conductive carbon. Metal ions can be generated by dissolving metal salts in water. Examples of defoaming agents include silicone resins, polydimethylsiloxanes, and silicone oils. Examples of coupling agents include silane coupling agents having vinyl groups, amino groups, epoxy groups, etc. Examples of antioxidants include phenolic antioxidants, amine antioxidants, phosphorus antioxidants, sulfur antioxidants, and sugars. Examples of UV absorbers include benzotriazole-based UV absorbers, benzophenone-based UV absorbers, salicylate-based UV absorbers, cyanoacrylate-based UV absorbers, oxanilide-based UV absorbers, hindered amine-based UV absorbers, and benzoate-based UV absorbers.

[0048] Method for producing conductive polymer dispersions A method for producing a conductive polymer dispersion according to the first aspect of the present invention includes, for example, adding a polyethyleneimine derivative and, if necessary, a neutralizing agent to an aqueous dispersion of a conductive composite. The composition of each component can be desired, and it is preferable to combine them within the preferred range described above. The aqueous dispersion of the conductive composite may be obtained by chemical oxidation polymerization of monomers that form a π-conjugated conductive polymer in an aqueous solution of polyanions using a known method, or a commercially available one may be used. To improve the dispersibility of conductive composites and polyethyleneimine derivatives in conductive polymer dispersions, it is preferable to perform high-pressure dispersion treatment using a high-pressure homogenizer with shear force.

[0049] Capacitor manufacturing method A second aspect of the present invention is a method for manufacturing a capacitor, comprising the step of applying a conductive polymer dispersion according to the first aspect to the surface of a dielectric layer formed on the surface of an anode made of a porous valve metal, and drying it to form a solid electrolyte layer.

[0050] A method for manufacturing a capacitor preferably includes the steps of: oxidizing the surface of an anode made of a porous valve metal to form a dielectric layer (dielectric formation step); arranging a cathode opposite the dielectric layer (cathode formation step); and forming a solid electrolyte layer on at least a portion of the surface of the dielectric layer (film formation step). Each step will be described below with reference to Figure 1.

[0051] [Dielectric Formation Process] In this process, the surface of the anode 11, which is made of a porous valve metal, is oxidized to form a dielectric layer 12. The method for forming the dielectric layer 12 is not particularly limited, and examples include anodic oxidation of the surface of the anode 11 in an electrolyte solution for chemical treatment, such as an aqueous solution of ammonium adipate, an aqueous solution of ammonium borate, or an aqueous solution of ammonium phosphate.

[0052] [Cathode formation process] In this process, a cathode 13 is placed opposite the dielectric layer 12. The method of arranging the cathode 13 is not particularly limited, and examples include forming the cathode 13 using a conductive paste such as carbon paste or silver paste, or arranging a metal foil such as aluminum foil opposite the dielectric layer 12.

[0053] [Film forming process] In this process, the aforementioned conductive polymer dispersion is applied to at least a portion of the surface of the dielectric layer 12 and dried to form a solid electrolyte layer 14.

[0054] Methods for applying the conductive polymer dispersion include, for example, dip coating, comma coating, reverse coating, lip coating, and microgravure coating. Of these, the method of immersing the anode 11 in the conductive polymer dispersion under reduced pressure is preferred. With the dip method, the conductive polymer dispersion can be sufficiently applied to the interior of the porous structure on the surface of the dielectric layer 12. After immersion, it is removed and the drying process is carried out.

[0055] Drying methods include, for example, room temperature drying, hot air drying, and far-infrared drying. Among these, hot air drying is preferred. The drying temperature is preferably 100 to 180°C, and more preferably 120 to 150°C. The drying time is preferably 0.2 to 1 hour. After drying, the capacitor can be assembled using conventional methods.

[0056] The composition of the components contained in the solid electrolyte layer 14 reflects the composition of the coated conductive polymer dispersion. The content of the polyethyleneimine derivative per 100 parts by mass of the conductive composite (total of π-conjugated conductive polymer and polyanion) contained in the solid electrolyte layer 14 is, for example, 1 part by mass or more and 50 parts by mass or less, preferably 1 part by mass or more and 30 parts by mass or less, more preferably 3 parts by mass or more and 15 parts by mass or less, and even more preferably 5 parts by mass or more and 10 parts by mass or less. If the value is above the lower limit of the above range, the effects of containing polyethyleneimine derivatives will be fully realized, resulting in improved capacitor performance. If the value is below the upper limit of the above range, the relative content of the conductive composite becomes sufficient, and as a result of the conductivity being fully expressed, the performance of the capacitor can be further improved.

[0057] Capacitor A third aspect of the present invention is a capacitor comprising an anode made of a porous valve metal, a dielectric layer made of an oxide of the valve metal, a cathode made of a conductive material provided on the dielectric layer opposite to the anode, and a solid electrolyte layer formed between the dielectric layer and the cathode, wherein the solid electrolyte layer contains a cured product of the conductive polymer dispersion of the first aspect. As an example, the capacitor of this aspect can be manufactured by the manufacturing method of the second aspect.

[0058] An example of an embodiment of the capacitor described above will be explained with reference to Figure 1. The capacitor 10 shown in Figure 1 comprises an anode 11 made of a porous valve metal, a dielectric layer 12 made of an oxide of the valve metal, a solid electrolyte layer 14 formed on the surface of the dielectric layer 12, and a cathode 13 provided on the outermost side. The cathode 13 is provided on the opposite side from the anode 11, with the dielectric layer 12 and the solid electrolyte layer 14 in between.

[0059] Examples of valve metals that constitute the anode 11 include aluminum, tantalum, niobium, titanium, hafnium, zirconium, zinc, tungsten, bismuth, and antimony. Of these, aluminum, tantalum, and niobium are preferred. Specific examples of anode 11 include aluminum foil that has been etched to increase its surface area and then oxidized, or sintered tantalum or niobium particles whose surface has been oxidized and formed into pellets. Materials treated in this way become porous bodies with irregularities formed on their surface.

[0060] In this embodiment, the dielectric layer 12 is a layer formed by oxidation of the surface of the anode 11. For example, it is formed by anodizing the surface of the metal anode 11 in an electrolyte such as an aqueous solution of ammonium adipate. Similar to the anode 11, the dielectric layer 12 also has irregularities formed on it.

[0061] In this embodiment, the cathode 13 can be a conductive layer formed from a conductive paste or a metal layer made of a conductive material such as aluminum foil.

[0062] In this embodiment, the solid electrolyte layer 14 is formed on the surface of the dielectric layer 12. The solid electrolyte layer 14 covers at least a portion of the surface of the dielectric layer 12, and may cover the entire surface of the dielectric layer 12. The thickness of the solid electrolyte layer 14 may be constant or not; for example, a thickness of 1 μm or more and 100 μm or less is possible.

[0063] [Electrolyte] The capacitor may have an electrolyte that impregnates a solid electrolyte layer. Examples of solvents that constitute the electrolyte include alcohol-based solvents such as ethylene glycol, diethylene glycol, propylene glycol, 1,4-butanediol, and glycerin; lactone-based solvents such as γ-butyrolactone, γ-valerolactone, and δ-valerolactone; sulfur-based solvents such as sulfolane, dimethyl sulfoxide, and dimethyl sulfone; amide-based solvents such as N-methylformamide, N,N-dimethylformamide, N-methylacetamide, and N-methylpyrrolidinone; nitrile-based solvents such as acetonitrile and 3-methoxypropionitrile; and water. The electrolytes constituting the electrolyte solution include, for example, adipic acid, glutaric acid, succinic acid, benzoic acid, isophthalic acid, phthalic acid, terephthalic acid, maleic acid, toluic acid, enanthic acid, malonic acid, formic acid, decanedicarboxylic acids such as 1,6-decanedicarboxylic acid and 5,6-decanedicarboxylic acid, octanedicarboxylic acids such as 1,7-octanedicarboxylic acid, organic acids such as azelaic acid and sebacic acid; or boric acid, polyhydric alcohol complex compounds of boric acid obtained from boric acid and polyhydric alcohols; and inorganic acids such as phosphoric acid, carbonic acid, and silicic acid as anionic components, with primary amines (methylamine, ethylamine, propylamine, Examples include electrolytes with cationic components such as butylamine, ethylenediamine, secondary amines (dimethylamine, diethylamine, dipropylamine, methylethylamine, diphenylamine, etc.), tertiary amines (trimethylamine, triethylamine, tripropylamine, triphenylamine, 1,8-diazabicyclo(5,4,0)-undecene-7, etc.), and tetraalkylammonium (tetramethylammonium, tetraethylammonium, tetrapropylammonium, tetrabutylammonium, methyltriethylammonium, dimethyldiethylammonium, etc.).

[0064] The capacitor is not limited to the configuration described above; a separator may be provided between the dielectric layer and the cathode. An example of a capacitor with a separator between the dielectric layer and the cathode is a wound-type capacitor. Examples of separators include sheets (including nonwoven fabrics) made of cellulose, polyvinyl alcohol, polyester, polyethylene, polystyrene, polypropylene, polyimide, polyamide, polyvinylidene fluoride, etc., and glass fiber nonwoven fabrics. The density of the separator is, for example, 0.1 g / cm³. 3 More than 1.0g / cm 3 The following are listed: When a separator is provided, a method can be applied in which carbon paste or silver paste is impregnated into the separator to form the cathode.

[0065] ≪Method for manufacturing conductive laminates≫ A fourth aspect of the present invention is a method for producing a conductive laminate by a manufacturing method that includes the step of coating a conductive polymer dispersion according to the first aspect of the present invention onto at least a portion of the surface of a substrate to form a conductive layer.

[0066] Methods for coating (applying) a conductive polymer dispersion to any surface of a substrate include, for example, methods using coaters such as gravure coaters, roll coaters, curtain flow coaters, spin coaters, bar coaters, reverse coaters, kiss coaters, fountain coaters, rod coaters, air doctor coaters, knife coaters, blade coaters, cast coaters, and screen coaters; methods using sprayers such as air sprayers, airless sprayers, and rotor dampening devices; and immersion methods such as dipping.

[0067] The amount of conductive polymer dispersion applied to the substrate is not particularly limited, but for example, 0.01 to 10.0 g / m² of non-volatile components is recommended. 2 A range of [this] is preferred.

[0068] A conductive layer can be formed by drying a coating film made of a conductive polymer dispersion applied to a substrate, removing at least a portion of the dispersion medium, and curing it. Methods for drying the coating include heat drying and vacuum drying. For heat drying, for example, methods such as hot air heating and infrared heating can be used. When applying heat drying, the heating temperature is set appropriately according to the dispersion medium used, but is usually within the range of 50°C to 200°C. Here, the heating temperature is the set temperature of the drying apparatus. Within the above heating temperature range, a suitable drying time is preferably 0.5 minutes to 30 minutes, and more preferably 1 minute to 15 minutes.

[0069] <<Conductive Laminate>> A fifth aspect of the present invention is a conductive laminate comprising a substrate and a conductive layer formed on at least a portion of the surface of the substrate, wherein the conductive layer contains a cured product of the conductive polymer dispersion of the first aspect. As an example, the conductive laminate of this aspect can be manufactured by the manufacturing method of the fourth aspect.

[0070] [Conductive layer] The area in which the conductive layer is formed may be the entire surface of any surface of the substrate, or it may be only a part of it. In the case of a conductive film, it is preferable that a conductive layer of substantially uniform thickness is formed on substantially the entire surface of one or the other surface of the film substrate. If the conductive layer is formed on only a part of the surface of the substrate, for example, the conductive layer may be a fine conductive pattern such as a circuit or an electrode, or the area with the conductive layer and the area without the conductive layer may exist on the same surface and be roughly separated.

[0071] The average thickness of the conductive layer is preferably, for example, 10 nm to 100 μm, more preferably 20 nm to 50 μm, and even more preferably 30 nm to 30 μm. If the average thickness of the conductive layer is above the lower limit, high conductivity can be achieved, and if it is below the upper limit, the adhesion of the conductive layer to the substrate is further improved.

[0072] The composition of the components contained in the conductive layer reflects the composition of the coated conductive polymer dispersion. The content of the polyethyleneimine derivative per 100 parts by mass of the conductive composite (total of π-conjugated conductive polymer and polyanions) contained in the conductive layer is preferably, for example, 1 part by mass or more and 50 parts by mass or less, more preferably 3 parts by mass or more and 40 parts by mass or less, and even more preferably 5 parts by mass or more and 30 parts by mass or less. Within this range, the conductivity of the conductive layer is good.

[0073] [Base material] The substrate may be made of an insulating material or a conductive material. The shape of the substrate is not particularly limited, and examples include mainly flat shapes such as films and substrates. Examples of insulating materials include glass, synthetic resins, and ceramics. Examples of conductive materials include metals, conductive metal oxides, and carbon.

[0074] (Film substrate) When a film substrate is used as the aforementioned substrate, the conductive laminate becomes a conductive film. Examples of the film substrate include plastic films made of synthetic resins. Examples of the synthetic resins include ethylene-methyl methacrylate copolymer resin, ethylene-vinyl acetate copolymer resin, polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinyl alcohol, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyacrylate, polycarbonate, polyvinylidene fluoride, polyarylate, styrene elastomer, polyester elastomer, polyethersulfone, polyetherimide, polyetheretherketone, polyphenylene sulfide, polyimide, cellulose triacetate, and cellulose acetate propionate. From the viewpoint of improving adhesion between the film substrate and the conductive layer, the synthetic resin for the film substrate is preferably a polyester resin, and among these, polyethylene terephthalate is preferred.

[0075] The synthetic resin used for the film substrate may be amorphous or crystalline. The film substrate may be unstretched or stretched. The film substrate may be subjected to surface treatments such as corona discharge treatment, plasma treatment, or flame treatment in order to further improve the adhesion of the conductive layer.

[0076] The average thickness of the film substrate is preferably 5 μm to 500 μm, and more preferably 20 μm to 200 μm. If the average thickness of the film substrate is above the lower limit, it becomes less prone to tearing, and if it is below the upper limit, sufficient flexibility as a film can be ensured. The average thickness of the film substrate is calculated by measuring the thickness at 10 randomly selected locations and averaging those measurements.

[0077] (Glass substrate) Examples of glass substrates include alkali-free glass substrates, soda-lime glass substrates, borosilicate glass substrates, and quartz glass substrates. Since the presence of alkaline components in the substrate tends to reduce the conductivity of the conductive layer, alkali-free glass is preferred among the glass substrates. Here, alkali-free glass refers to a glass composition in which the content of alkaline components is 0.1% by mass or less of the total mass of the glass composition.

[0078] The average thickness of the glass substrate is preferably 100 μm to 3000 μm, and more preferably 100 μm to 1000 μm. If the average thickness of the glass substrate is above the lower limit, it becomes less prone to breakage, and if it is below the upper limit, it contributes to thinning the conductive laminate. The average thickness of the glass substrate is calculated by measuring the thickness at 10 randomly selected locations and averaging those measurements. [Examples]

[0079] (Manufacturing Example 1) Production of polystyrene sulfonic acid 206 g of sodium styrene sulfonate was dissolved in 1000 ml of deionized water, and while stirring at 80°C, 1.14 g of ammonium persulfate oxidizing agent solution, which had been previously dissolved in 10 ml of water, was added dropwise for 20 minutes, and this solution was stirred for 12 hours. To the obtained sodium polystyrene sulfonate solution, 1000 ml of sulfuric acid diluted to 10% by mass was added, and approximately 1000 ml of the solvent from the resulting polystyrene sulfonate solution was removed by ultrafiltration. Next, 2000 ml of deionized water was added to the remaining solution, and approximately 2000 ml of solvent was removed by ultrafiltration to wash the polystyrene sulfonate with water. This washing procedure was repeated three times. The water in the resulting solution was removed under reduced pressure to obtain colorless, solid polystyrene sulfonic acid (PSS).

[0080] (Manufacturing Example 2) Production of PEDOT-PSS aqueous dispersion A solution of 14.2 g of 3,4-ethylenedioxythiophene and 36.7 g of polystyrene sulfonic acid dissolved in 2000 ml of deionized water was mixed at 20°C. The resulting mixed solution was kept at 20°C, and while stirring, a solution of 29.64 g of ammonium persulfate and 8.0 g of ferric sulfate, dissolved in 200 ml of deionized water, was slowly added as an oxidation catalyst, and the mixture was stirred for 3 hours to allow the reaction to proceed. 2000 ml of deionized water was added to the resulting reaction mixture, and approximately 2000 ml of solvent was removed by ultrafiltration. This procedure was repeated three times. Then, 200 ml of sulfuric acid diluted to 10% by mass and 2000 ml of deionized water were added to the obtained solution, and approximately 2000 ml of solvent was removed by ultrafiltration. 2000 ml of deionized water was added to the remaining solution, and approximately 2000 ml of the solution was removed by ultrafiltration. This procedure was repeated three times. Furthermore, 2000 ml of deionized water was added to the obtained solution, and approximately 2000 ml of solvent was removed by ultrafiltration. This procedure was repeated five times to obtain a 1.2% by mass polystyrene sulfonic acid-doped poly(3,4-ethylenedioxythiophene) solution (PEDOT-PSS aqueous dispersion). Then, the solution was concentrated to 1.6% by mass by further ultrafiltration, and treated at 160 MPa using a high-pressure homogenizer to obtain a PEDOT-PSS aqueous dispersion (conductive polymer dispersion).

[0081] (Manufacturing Example 3) Fabrication of capacitor elements After connecting anode lead terminals to etched aluminum foil (anodic foil), a voltage of 40V was applied in a 10% by mass aqueous solution of ammonium adipate to perform a chemical conversion (oxidation treatment) to form dielectric layers on both sides of the aluminum foil and obtain the anode foil. Next, opposing aluminum cathode foils, each with cathode lead terminals welded to both sides of an anode foil, were laminated with a cellulose separator in between, and this was wound into a cylindrical shape to obtain a capacitor element.

[0082] (Manufacturing Example 4) Electrolyte for Driving A driving electrolyte was obtained by mixing 55 parts by mass of γ-butyrolactone, 35 parts by mass of sulfolane, and 10 parts by mass of diammonium adipate.

[0083] (Example 1) To 100 g of the conductive polymer dispersion obtained in Production Example 2, add 0.5 g of imidazole (31.25 parts by mass per 100 parts by mass of conductive composite) and ethoxylated polyethyleneimine (manufactured by Nippon Shokubai Co., Ltd., PN-100; approximately 100% of the hydrogen atoms bonded to the nitrogen atom are groups represented by formula (1) (R 1 0.1 g (6.25 parts by mass per 100 parts by mass of conductive composite) of a substance ethoxylated with hydrogen atoms was added, and the mixture was stirred to obtain a conductive polymer dispersion. The pH was 6.0. Next, the capacitor element obtained in Manufacturing Example 3 was immersed in the conductive polymer dispersion under reduced pressure, and then dried twice in a hot air dryer at 125°C for 30 minutes each time. This process formed a solid electrolyte layer containing a conductive composite on the surface of the dielectric layer, thereby obtaining a solid electrolytic capacitor. Next, a solid electrolytic capacitor with a solid electrolyte layer formed on top of it, along with the driving electrolyte obtained in Manufacturing Example 4, was loaded into an aluminum case, sealed with a sealing rubber, and a voltage of 32V was applied in a 125°C atmosphere to obtain the capacitor.

[0084] (Example 2) A capacitor was obtained in the same manner as in Example 1, except that the amount of ethoxylated polyethyleneimine added was 0.3 g (18.75 parts by mass per 100 parts by mass of conductive composite). The pH of the obtained conductive polymer dispersion was 6.0.

[0085] (Example 3) A capacitor was obtained in the same manner as in Example 1, except that the amount of imidazole added was changed to 0.7 g (43.75 parts by mass per 100 parts by mass of conductive composite). The pH of the obtained conductive polymer dispersion was 6.9.

[0086] (Example 4) A capacitor was obtained in the same manner as in Example 1, except that the amount of imidazole added was changed to 0.4 g (25.00 parts by mass per 100 parts by mass of conductive composite) and the amount of ethoxylated polyethyleneimine added was changed to 0.05 g (3.125 parts by mass per 100 parts by mass of conductive composite). The pH of the obtained conductive polymer dispersion was 2.7.

[0087] (Example 5) A capacitor was obtained in the same manner as in Example 2, except that imidazole was replaced with triethylamine. The pH of the obtained conductive polymer dispersion was 3.1.

[0088] (Comparative Example 1) A capacitor was obtained in the same manner as in Example 1, except that ethoxylated polyethyleneimine was not added.

[0089] (Comparative Example 2) When 0.1 g of a 37 wt% aqueous solution of 80% ethoxylated polyethyleneimine was added to 100 g of the conductive polymer dispersion obtained in Production Example 2, aggregates formed in the conductive polymer dispersion, and a capacitor could not be obtained.

[0090] [Measuring pH] The pH was measured at 25°C using a commercially available pH meter and a standard method.

[0091] [Capacitance and equivalent series resistance] For each example, the solid electrolytic capacitor and capacitor fabricated were measured using an LCR meter ZM2376 (manufactured by NF Circuit Design Block Co., Ltd.) to determine the capacitance at 120 Hz and the equivalent series resistance at 100 kHz, respectively.

[0092] [Leakage current] For each example, a DC voltage of 25V was applied to the capacitors fabricated in a 20°C environment, and the leakage current value was measured after 120 seconds.

[0093] [Heat resistance test] The capacitors obtained as described above were placed in a hot air dryer at 145°C for 1000 hours, removed, and cooled at room temperature for 30 minutes. After cooling, the capacitance, equivalent series resistance, and leakage current of the capacitors were measured as described above.

[0094] [Table 1]

[0095] From the above, it can be concluded that the conductive polymer dispersion produced in the embodiment of the present invention contains a specific polyethyleneimine derivative, resulting in superior performance of the produced capacitor. Furthermore, it was confirmed that when the concentration of the polyethyleneimine derivative in the conductive polymer dispersion is appropriate, the capacitance of the capacitor tends to increase further, the equivalent series resistance (ESR) decreases further, and the leakage current tends to decrease even more. [Explanation of symbols]

[0096] 10 Capacitors 11 Anode 12 Dielectric layer 13 Cathode 14 Solid electrolyte layer

Claims

1. A conductive polymer dispersion containing a conductive composite comprising a π-conjugated conductive polymer and a polyanion, a polyethyleneimine derivative, at least one of a nitrogen-containing aromatic cyclic compound and a tertiary amine, and a dispersion medium. The polyethyleneimine derivative is a conductive polymer dispersion in which more than 80% of the hydrogen atoms bonded to the nitrogen atoms constituting polyethyleneimine are substituted by a group represented by formula (1). 【Chemistry 1】 [In equation (1), n ​​represents a natural number, R １ [This represents a hydrogen atom or any monovalent organic group.]

2. The conductive polymer dispersion according to claim 1, wherein the molecular weight of the polyethyleneimine derivative is 10,000 or more and 200,000 or less.

3. The conductive polymer dispersion according to claim 1, wherein the content of the polyethyleneimine derivative is 1 part by mass or more and 50 parts by mass or less per 100 parts by mass of the conductive composite.

4. The conductive polymer dispersion according to claim 3, wherein the water content is 60% by mass or more relative to the total mass of the dispersion medium.

5. The conductive polymer dispersion according to claim 4, wherein the pH at a temperature of 25°C is 3.0 or higher and less than 7.

0.

6. The π-conjugated conductive polymer is poly(3,4-ethylenedioxythiophene), or the polyanion is polystyrene sulfonic acid, or The conductive polymer dispersion according to claim 5, wherein the π-conjugated conductive polymer is poly(3,4-ethylenedioxythiophene) and the polyanion is polystyrene sulfonic acid.

7. The device comprises an anode made of a porous valve metal, a dielectric layer made of an oxide of the valve metal, a cathode made of a conductive material provided on the dielectric layer opposite to the anode, and a solid electrolyte layer formed between the dielectric layer and the cathode. A capacitor wherein the solid electrolyte layer is a cured product of a conductive polymer dispersion according to any one of claims 1 to 6.

8. A method for manufacturing a capacitor, comprising the step of applying a conductive polymer dispersion according to any one of claims 1 to 6 to the surface of a dielectric layer formed on the surface of an anode made of a porous valve metal, and drying it to form a solid electrolyte layer.

9. The system comprises a base material and a conductive layer formed on at least a portion of the surface of the base material, A conductive laminate in which the conductive layer is a cured product of a conductive polymer dispersion according to any one of claims 1 to 6.

10. A method for producing a conductive laminate, comprising the steps of applying a conductive polymer dispersion according to any one of claims 1 to 6 to at least a portion of the surface of a substrate, and drying it to form a conductive layer.

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