Conductive polymer solution and its uses

Abstract

To provide a conductive polymer solution for producing an electrolytic capacitor that can thicken an outer layer containing a conductive polymer formed in a capacitor anode and can achieve excellent coating of a corner and an edge.SOLUTION: A conductive polymer solution contains a polythiophene (A) at least containing any structural unit represented by the general formula (1) (where R1 is a hydrogen atom, a C1-6 linear or branched alkyl group, or a halogen atom, m is an integer of 1-6, n is 0 or 1), and a diamine compound (B).SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a conductive polymer solution, a conductive polymer film, and an electrolytic capacitor using the same.

Background Art

[0002] In recent years, conductive polymer materials in which π-conjugated polymers typified by polyacetylene, polythiophene, polyaniline, polypyrrole, etc. are doped with an electron-accepting compound as a dopant have been developed. Such conductive polymer materials are being studied for applications such as antistatic agents, solid electrolytes for electrolytic capacitors, conductive paints, electrochromic elements, electrode materials, thermoelectric conversion materials, transparent conductive films, chemical sensors, actuators, etc.

[0003] As a conductive polymer material used in an electrolytic capacitor, a polythiophene-based conductive polymer material is practically useful from the viewpoint of chemical stability. Examples of polythiophene-based conductive polymer materials include (i) a PEDOT / PSS aqueous dispersion solution obtained by polymerizing 3,4-ethylenedioxythiophene (EDOT) in an aqueous solution of polystyrene sulfonic acid (PSS) as a dopant, and (ii) so-called self-doped conductive polymers having a substituent (sulfonic group, sulfonate group, etc.) having both a water-solubility imparting and doping action directly or via a spacer in the polymer main chain (for example, sulfonated polyaniline, PEDOT-S, etc.) (see, for example, Non-Patent Document 1). Further, as a method for forming the outer layer of an electrolytic capacitor, a method by in-situ polymerization of PEDOT / PSS is generally known (Patent Document 1).

Prior Art Documents

Non-Patent Documents

[0004]

Non-Patent Document 1

Patent Documents

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2009-505413 [Summary of the Invention] [Problems to be Solved by the Invention]

[0006] In the production of electrolytic capacitors, thickening of the outer layer containing a conductive polymer formed on the capacitor anode is required. In particular, good coating on the corners and edges of the capacitor anode is required. Therefore, one aspect of the present invention is to provide a conductive polymer solution for manufacturing an electrolytic capacitor capable of thickening the outer layer containing a conductive polymer formed on the capacitor anode and achieving good coating on the corners and edges. [Means for Solving the Problems]

[0007] As a result of intensive studies to solve the above problems, the present inventors have found that by using the conductive polymer solution shown below, the outer layer containing a conductive polymer formed on the capacitor anode can be thickened and good coating on the corners and edges can be achieved, and thus the present invention has been completed.

[0008] That is, one aspect of the present invention includes the following [1] to [8]. [1] A structural unit represented by at least the following general formula (1) and a structural unit represented by (2)

[0009] [Chemical Formula]

[0010] [Chemical Formula]

[0011] {In the above general formulas (1) and (2), R 1represents a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, or a halogen atom. m represents an integer of 1 to 6, and n represents 0 or 1.} A conductive polymer solution comprising at least two or more structural units selected from the group consisting of polythiophene (A) and a diamine compound (B). [2] The diamine compound (B) is represented by the following general formula (3)

[0012]

Chemical formula

[0013] {In the above general formula (3), R 2 , R 3 , R 4 , and R 5 each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkyl group having 1 to 10 carbon atoms with a substituent. R 6 represents an alkylene group having 1 to 20 carbon atoms, or an alkylene group having 1 to 20 carbon atoms with a substituent.} A diamine compound represented by the formula, and the following general formula (4)

[0014]

Chemical formula

[0015] {In the above general formula (4), R 2 , R 3 , R 4 , and R 5 each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkyl group having 1 to 10 carbon atoms with a substituent. R 6 each independently represent an alkylene group having 1 to 20 carbon atoms, or an alkylene group having 1 to 20 carbon atoms with a substituent. p represents an integer of 1 to 5.} The conductive polymer solution according to [1], which is at least one selected from the group consisting of diamine compounds represented by the formula. [3] The diamine compound (B) is represented by the following general formula (3’)

[0016] [Chemical formula]

[0017] {In the above general formula (3’), R 6 represents an alkylene group having 2 to 12 carbon atoms in total, or an alkylene group having 2 to 12 carbon atoms in total and having a substituent.} A diamine compound represented by the following general formula (4’), and the following general formula (4’)

[0018] [Chemical formula]

[0019] {In the above general formula (4’), R 6 represents an alkylene group having 2 to 12 carbon atoms in total, or an alkylene group having 2 to 12 carbon atoms in total and having a substituent. p represents an integer of 1 to 5.} The conductive polymer solution according to [1] or [2], which is at least one selected from the group consisting of diamine compounds represented by the following general formula (4’). [4] The conductive polymer solution according to any one of [1] to [3], wherein m is 2 or 3. [5] The conductive polymer solution according to any one of [1] to [4], wherein the R 1 is a methyl group. [6] The conductive polymer solution according to any one of [1] to [5], wherein the content of the polythiophene (A) is 0.01 to 10% by weight based on the total conductive polymer solution. [7] The conductive polymer solution according to any one of [1] to [6], wherein the weight ratio of the polythiophene (A) to the diamine compound (B) is 0.01 to 10 parts by weight of the diamine compound (B) with respect to 1 part by weight of the polythiophene (A). [8] A method for producing a conductive polymer film, comprising the step of applying the conductive polymer solution according to any one of [1] to [7] to a substrate and then drying to obtain a conductive polymer film. [9] At least a structural unit represented by the following general formula (1) and a structural unit represented by the following general formula (2)

[0020] [Chemical formula]

[0021] [Chemical formula]

[0022] {In the above general formulas (1) and (2), R 1 represents a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, or a halogen atom. m represents an integer of 1 to 6, and n represents 0 or 1.} A conductive polymer film containing at least two or more structural units selected from the group consisting of polythiophene (A) and a diamine compound (B). An electrolytic capacitor characterized by comprising the conductive polymer film described in

[10] [9]. [Advantages of the Invention]

[0023] According to one aspect of the present invention, compared with those previously reported, the outer layer containing a conductive polymer formed on the capacitor anode can be thickened, and good coating on corners and edges can be achieved. Therefore, leakage current can be suppressed, and improvement in the characteristics of the electrolytic capacitor can be expected. [Modes for Carrying Out the Invention]

[0024] Hereinafter, an embodiment of the present invention will be described in detail. Unless otherwise specified in this specification, "A to B" representing a numerical range means "A or more and B or less".

[0025] One embodiment of the present invention aims to provide a novel conductive polymer solution capable of achieving a good surface coverage rate, and an electrolytic capacitor using the same.

[0026] In the field of electrolytic capacitors, with the high-speed and high-frequency operation of electronic devices, there is a strong demand for electrolytic capacitors with long life, high capacitance, and low ESR (equivalent series resistance). In addition to the above requirements, recent electrolytic capacitors also require an improvement in the coating rate of the conductive polymer on the capacitor anode. In particular, when the coating rate at the corners and edges of the capacitor anode is low, the leakage current increases due to the influence of mechanical stress when encapsulating the capacitor anode. Therefore, in order to suppress the leakage current, it is required that the film thickness of the outer layer containing the conductive polymer on the capacitor anode be 5 μm or more. This layer prevents the contact between the dielectric and the cathode of the capacitor anode and the damage of the dielectric when mechanical stress occurs, and suppresses the leakage current.

[0027] However, in order to increase the coating rate on the capacitor anode by the method of Patent Document 1, many cycles are required for coating, the formation of the outer layer becomes very uneven, and the coating at the corners and edges of the capacitor anode is insufficient.

[0028] As described above, the conductive polymer solution of the present embodiment contains at least a structural unit represented by the following general formula (1) and a structural unit represented by the following general formula (2).

[0029]

Chemical formula

[0030]

Chemical formula

[0031] {In the above general formulas (1) and (2), R 1 represents a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, or a halogen atom. m represents an integer of 1 to 6, and n represents 0 or 1.} contains at least two or more structural units selected from the group consisting of polythiophene (A) and diamine compound (B).

[0032] The polythiophene of this embodiment is a polythiophene containing at least two or more of at least one structural unit selected from the group consisting of the structural unit represented by the above general formula (1) and the structural unit represented by general formula (2). This polythiophene corresponds to a conductive polymer.

[0033] The structural unit represented by the above general formula (2) represents the doping state of the structural unit represented by the above general formula (1), and the doping state is expressed by the sulfonic acid group or sulfonate group in the structural unit represented by the above general formula (1) acting as a p-type dopant. A polymer that exhibits conductivity without adding a dopant from the outside in this way is called a self-doping type polymer.

[0034] In the above general formulas (1) and (2), R 1 represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a halogen atom.

[0035] The alkyl group having 1 to 6 carbon atoms (for the alkyl group having 3 to 6 carbon atoms, it may be linear or branched) 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, or a cyclohexyl group.

[0036] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom.

[0037] Among these, for the substituent R 1 from the viewpoint of film-forming properties, it is preferably a hydrogen atom, a methyl group, an ethyl group, a fluorine atom, a chlorine atom, or a bromine atom, more preferably a hydrogen atom, a methyl group, or a fluorine atom, and even more preferably a methyl group.

[0038] As the diamine compound (B), for example, the following general formula (3)

[0039]

Chemical formula

[0040] {In the above general formula (3), R 2 , R 3 , R 4 , and R 5 each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms in total, or an alkyl group having 1 to 10 carbon atoms in total and having a substituent. R 6 represents an alkylene group having 1 to 20 carbon atoms in total, or an alkylene group having 1 to 20 carbon atoms in total and having a substituent.} A diamine compound represented by, and the following general formula (4)

[0041]

Chemical formula

[0042] {In the above general formula (4), R 2 , R 3 , R 4 , and R 5 each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms in total, or an alkyl group having 1 to 10 carbon atoms in total and having a substituent. R 6 each independently represents an alkylene group having 1 to 20 carbon atoms in total, or an alkylene group having 1 to 20 carbon atoms in total and having a substituent. p represents an integer from 1 to 5.} At least one selected from the group consisting of diamine compounds represented by is mentioned.

[0043] In the above general formulas (3) and (4), R 2 , R 3 , R 4 , and R 5Each independently represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms (for an alkyl group having 3 to 10 carbon atoms, it may be linear, branched, or cyclic), or an alkyl group having 1 to 10 carbon atoms with a substituent (for an alkyl group having 3 to 10 carbon atoms, it may be linear, branched, or cyclic).

[0044] The alkyl group having 1 to 10 carbon atoms (for an alkyl group having 3 to 10 carbon atoms, it may be linear, branched, or cyclic) is not particularly limited, and examples 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, a cyclohexyl group, an n-heptyl group, a methylhexyl group, an n-octyl group, a methylheptyl group, an ethylhexyl group, an n-nonyl group, an n-decyl group, an ethyloctyl group, and the like.

[0045] Examples of the alkyl group having 1 to 10 carbon atoms with a substituent (for an alkyl group having 3 to 10 carbon atoms, it may be linear, branched, or cyclic) include an alkyl group having 1 to 10 carbon atoms with a halogen atom, an amino group, or a hydroxy group (for an alkyl group having 3 to 10 carbon atoms, it may be linear, branched, or cyclic). Specific examples include a trifluoromethyl group, a 2-hydroxyethyl group, an 8-hydroxyoctyl group, a 9-aminononyl group, and the like.

[0046] Among these, R 2 、R 3 、R 4 、and R 5Examples of these include, independently of each other, a hydrogen atom, 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 n-hexyl group, a 2-ethylbutyl group, an n-heptyl group, a methylhexyl group, an n-octyl group, a methylheptyl group, a 2-ethylhexyl group, an n-nonyl group, and an n-decyl group.

[0047] In the above general formulas (3) and (4), R 6 each independently represents an alkylene group having 1 to 20 carbon atoms in total (wherein, for an alkylene group having 3 to 20 carbon atoms in total, it may be linear, branched, or cyclic), or an alkylene group having 1 to 20 carbon atoms in total and having a substituent (wherein, for an alkylene group having 3 to 20 carbon atoms in total, it may be linear, branched, or cyclic).

[0048] Examples of the alkylene group having 1 to 20 carbon atoms in total (wherein, for an alkylene group having 3 to 20 carbon atoms in total, it may be linear, branched, or cyclic) are not particularly limited, and include, for example, a methylene group, an ethylene group, an n-propylene group, an isopropyl group, an n-butylene group, an isobutylene group, a sec-butylene group, a tert-butylene group, an n-pentylene group, an isopentylene group, a neopentylene group, a tert-pentylene group, a cyclopentylene group, an n-hexylene group, a 2-ethylbutylene group, a cyclohexylene group, an n-heptylene group, a methylhexylene group, an n-octylene group, a methylheptylene group, an ethylhexylene group, an n-nonylene group, an n-decylene group, an ethyloctylene group, a butylhexylene group, an n-undecylene group, an n-dodecylene group, an n-hexadecylene group, an n-heptadecylene group, an octylnonylene group, an n-octadecylene group, an n-nonadecylene group, an n-icosylene group, an octyldodecylene group, and the like.

[0049] An alkylene group having 1 to 20 carbon atoms in total and having a substituent (for an alkylene group having 3 to 20 carbon atoms in total, it may be linear, branched, or cyclic.) includes, for example, an alkylene group having 1 to 20 carbon atoms in total and having a halogen atom, an amino group, or a hydroxy group (for an alkylene group having 3 to 20 carbon atoms in total, it may be linear, branched, or cyclic.). Specifically, a trifluoromethylene group, a 2-hydroxyethylene group, an 8-hydroxyoctylene group, a 9-aminononylene group, etc. are exemplified.

[0050] Among these, R 6 is preferably, independently of each other, a methylene group, an ethylene group, an n-propylene group, an isopropylene group, an n-butylene group, an isobutylene group, a sec-butylene group, a tert-butylene group, an n-pentylene group, an n-hexylene group, a 2-ethylbutylene group, an n-heptylene group, a methylhexylene group, an n-octylene group, a methylheptylene group, a 2-ethylhexylene group, an n-nonylene group, an n-decylene group, or an n-dodecylene group.

[0051] The diamine compounds represented by the above general formulas (3) and (4) are not particularly limited, and examples thereof include 1,2-diaminoethane, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminooctane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,12-diaminododecane, 1,2-diaminopropane, 1,3-diamino-2-methylpropane, 1,2-diamino-2-methylpropane, 1,3-diamino-2,2-dimethylpropane, 1,4-cyclohexanediamine, 1,3-cyclohexanediamine, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, 4,4'-methylenebis(cyclohexylamine), 4,4'-methylenebis(2-methylcyclohexylamine), 2-(diethylamino)ethylamine, 2-(diisopropylamino)ethylamine, 3-(cyclohexylamino)propylamine, 3-(diethylamino)propylamine, 3-(dimethylamino)propylamine, N,N,N',N'-tetramethyl-1,2-diaminoethane, N,N,N',N'-tetramethyl-1,3-diaminopropane, N,N,N',N'-tetramethyl-1,4-diaminobutane, N,N,N',N'-tetramethyl-1,5-diaminooctane, N,N,N',N'-tetramethyl-1,6-diaminohexane, N,N,N',N'-tetramethyl-1,7-diaminoheptane, N,N,N',N'-tetramethyl-1,8-diaminooctane, N,N,N',N'-tetramethyl-1,9-diaminononane, N,N,N',N'-tetramethyl-1,10-diaminodecane, N,N,N',N'-tetramethyl-1,12-diaminododecane, 2,2'-oxybis(ethylamine), 1,2-bis(2-aminoethoxy)ethane, 1,4-butanediol bis(3-aminopropyl) ether, diethylene glycol bis(3-aminopropyl) ether, bis(2-dimethylaminoethyl) ether, 2-[[2-(dimethylamino)ethyl]methylamino]ethanol, and the like.

[0052] These compounds may be used alone or in combination of two or more thereof.

[0053] The diamine compound (B) is represented by the following general formula (3’)

[0054]

Chemical formula

[0055] {In the above general formula (3’), R 6 represents an alkylene group having 2 to 12 carbon atoms in total or an alkylene group having 2 to 12 carbon atoms in total and having a substituent.} a diamine compound represented by the formula, and the following general formula (4’)

[0056]

Chemical formula

[0057] {In the above general formula (4’), R 6 represents an alkylene group having 2 to 12 carbon atoms in total or an alkylene group having 2 to 12 carbon atoms in total and having a substituent. p represents an integer of 1 to 5.} It may be at least one selected from the group consisting of diamine compounds represented by the formula.

[0058] In the above general formula (1) or (2), m represents an integer of 1 to 6, preferably an integer of 1 to 4, and more preferably 2 or 3.

[0059] The polythiophene (A) of this embodiment can be produced by polymerizing a thiophene monomer represented by the following general formula (5) in water or an alcohol solvent in the presence of an oxidizing agent and then, if necessary, subjecting it to an acid treatment.

[0060]

Chemical formula

[0061] {In general formula (5), M represents a hydrogen ion or a metal ion. R represents a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, or a halogen atom. m represents an integer of 1 to 6, and n represents 0 or 1.} The metal ion represented by M in formula (5) is not particularly limited, and examples thereof include transition metal ions, noble metal ions, non-ferrous metal ions, alkali metal ions (for example, Li ion, Na ion, and K ion), alkaline earth metal ions, and the like.

[0062] When the polymer obtained after polymerization of the thiophene monomer represented by general formula (5) is a metal salt, M can be converted to a hydrogen ion by subjecting the obtained metal salt polymer to an acid treatment.

[0063] The thiophene monomer represented by the above general formula (5) is not particularly limited, but specifically, 6-(2,3-dihydro-thieno[3,4-b][1,4]dioxin-2-yl)hexane-1-sulfonic acid, sodium 6-(2,3-dihydro-thieno[3,4-b][1,4]dioxin-2-yl)hexane-1-sulfonate, lithium 6-(2,3-dihydro-thieno[3,4-b][1,4]dioxin-2-yl)hexane-1-sulfonate, potassium 6-(2,3-dihydro-thieno[3,4-b][1,4]dioxin-2-yl)hexane-1-sulfonate, 8-(2,3-dihydro-thieno[3,4-b][1,4]dioxin-2-yl)octane-1-sulfonic acid, sodium 8-(2,3-dihydro-thieno[3,4-b][1,4]dioxin-2-yl)octane-1-sulfonate, and potassium 8-(2,3-dihydro-thieno[3,4-b][1,4]dioxin-2-yl)octane-1-sulfonate, sodium 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-propanesulfonate, potassium 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-propanesulfonate, sodium 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-methyl-1-propanesulfonate, sodium 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-ethyl-1-propanesulfonate, sodium 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-propyl-1-propanesulfonate, sodium 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-butyl-1-propanesulfonate, sodium 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-pentyl-1-propanesulfonate, sodium 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-hexyl-1-propanesulfonate, sodium 3-[(2,3-dihydrothieno[3,4-b]-[1,Sodium 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-isopropyl-1-propanesulfonate, sodium 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-isobutyl-1-propanesulfonate, sodium 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-isopentyl-1-propanesulfonate, sodium 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-fluoro-1-propanesulfonate, potassium 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-methyl-1-propanesulfonate, 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-methyl-1-propanesulfonic acid, ammonium 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-methyl-1-propanesulfonate, triethylammonium 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-methyl-1-propanesulfonate, sodium 4-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-butanesulfonate, potassium 4-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-butanesulfonate, sodium 4-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-methyl-1-butanesulfonate, potassium 4-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-methyl-1-butanesulfonate, sodium 4-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-fluoro-1-butanesulfonate, and potassium 4-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-fluoro-1-butanesulfonate, etc. are exemplified.,

[0064] In this embodiment, the conductivity of polythiophene (A) is not particularly limited, but as the conductivity (electrical conductivity) in the film state, it is preferably 10 S / cm or more.

[0065] Regarding the polythiophene (A) in this embodiment, those synthesized based on publicly known information can also be used.

[0066] The content of polythiophene (A) is preferably 0.01 to 10% by weight based on the entire conductive polymer solution, more preferably 0.05 to 9% by weight, and even more preferably 0.1 to 8% by weight in terms of excellent low ESR.

[0067] The weight ratio of the polythiophene (A) to the diamine compound (B) is preferably 0.01 to 10 parts by weight of the diamine compound (B) with respect to 1 part by weight of the polythiophene (A), more preferably 0.05 to 8 parts by weight, and even more preferably 0.05 to 7 parts by weight.

[0068] The amount of the diamine compound (B) is not particularly limited, but is preferably 0.01 to 10 times the molar amount of the charged polythiophene (A) calculated by the following formula, and more preferably 0.05 to 5 times the molar amount.

[0069]

Equation

[0070] Examples of the repeating unit include the structural unit represented by the above general formula (1) and the structural unit represented by the general formula (2).

[0071] In the conductive polymer solution of the present embodiment, in terms of excellent coating property on the capacitor anode, its pH is preferably in the range of 1.5 to 13.5, more preferably in the range of 2.0 to 12.5, and even more preferably in the range of 2.0 to 11.5. The pH can be controlled by the type and content of the amine compound (B) and the addition of a pH adjuster.

[0072] The pH adjuster is not particularly limited, and examples thereof include sulfonic acid compounds (such as paratoluenesulfonic acid and polystyrenesulfonic acid), carboxylic acid compounds (such as succinic acid and citric acid), and phosphoric acid.

[0073] When mixing the conductive polymer solution of the present embodiment, in addition to general mixing and dissolution operations using a stirrer chip, stirring blades, etc., ultrasonic irradiation or homogenization treatment (for example, using a mechanical homogenizer, ultrasonic homogenizer, high-pressure homogenizer, etc.) may be performed.

[0074] Note that the mixing can also be carried out with appropriate temperature control, which is not particularly limited. For example, it can be mixed in the range of 10 to 80°C, preferably in the range of 15 to 60°C, and more preferably in the range of 20 to 50°C.

[0075] Also, the mixing is preferably carried out after oxygen degassing. The method of oxygen degassing is not particularly limited, and examples thereof include vacuum treatment or nitrogen bubbling.

[0076] The mixing time is not particularly limited, and for example, it is preferably in the range of 1 minute to 12 hours, and more preferably in the range of 1 minute to 6 hours.

[0077] The viscosity (20°C) of the conductive polymer solution of the present embodiment is not particularly limited, but is preferably 500 mPa·s or less, more preferably 300 mPa·s or less, and even more preferably 200 mPa·s or less.

[0078] Regarding the conductive polymer solution of this embodiment, it can be applied onto a support (substrate) and then dried to obtain a conductive polymer film.

[0079] The support is not particularly limited as long as the conductive polymer solution of this embodiment can be applied thereto, and examples thereof include a polymer substrate or an inorganic substrate. More specifically, for example, a thermoplastic resin, a nonwoven fabric, paper, etc. are included. Examples of the thermoplastic resin include polyethylene, polypropylene, polyethylene terephthalate, polyacrylate, or polycarbonate, etc. The nonwoven fabric may be either natural fiber or synthetic fiber, for example. The paper may be a general one mainly composed of cellulose. Other inorganic substrates are not particularly limited, and examples thereof include glass, glass fiber, ceramics, aluminum oxide, tantalum oxide, etc. The support may be a capacitor anode described later.

[0080] The coating method of the conductive polymer solution of this embodiment is not particularly limited, and examples thereof include a casting method, a dipping method, a bar coating method, a dispenser method, a roll coating method, a gravure coating method, a flexographic printing method, a spray coating method, a spin coating method, an inkjet method, etc. Preferably, it is a spin coating method.

[0081] The drying temperature of the coating film is not particularly limited as long as it is at a temperature at which a uniform film can be obtained and below the heat resistance temperature of the substrate, but it is in the range of room temperature to 300 °C, preferably in the range of room temperature to 250 °C, and more preferably in the range of room temperature to 200 °C. For example, by heating the coating film to 40 °C or higher to evaporate the solvent, a good conductive polymer film with a film thickness at the micron level can be manufactured.

[0082] The drying atmosphere may be any of in the air, in an inert gas, in a vacuum, or under reduced pressure. From the viewpoint of suppressing the deterioration of the polymer film, it is preferable to be in an inert gas such as nitrogen or argon.

[0083] As components other than the above-mentioned polythiophene (A) and diamine compound (B), there are no particular limitations, but examples thereof include binder resins, surfactants, monoamine compounds, silane compounds, solvents, and the like.

[0084] As the above-mentioned binder resin, there are no particular limitations, but examples thereof include acrylic resins, polyurethane resins, polymethyl methacrylate resins, styrene-butadiene resins, vinyl acetate resins, polyamide resins, phenol resins, epoxy resins, melamine resins, thermosetting polyimides, nitrocellulose or other cellulose resins, polyvinyl alcohol resins, polystyrene sulfonic acid resins, polyvinyl pyrrolidone resins, or polyester resins.

[0085] These binder resins may be used alone or in combination of two or more.

[0086] Examples of the above-mentioned polyester resin include polyethylene terephthalate or polytrimethylene terephthalate. The polyester resin may be self-emulsifying or strongly emulsifying, but from the viewpoints of water resistance and solvent resistance, a self-emulsifying polyester resin is preferred.

[0087] Examples of the above-mentioned polyester resin include those commercially available under the trade names: Byronal (registered trademark) manufactured by Toyobo Co., Ltd., Pesresin manufactured by Takamatsu Oil & Fat Co., Ltd., Plascoat (registered trademark) manufactured by Gohsei Chemical Industry Co., Ltd., Aron Melt (registered trademark) manufactured by Toagosei Co., Ltd., Pesresin A manufactured by Takamatsu Oil & Fat Co., Ltd., and Waterzol (registered trademark) manufactured by DIC Corporation.

[0088] The above-mentioned polyester resin can be used alone or in combination of two or more.

[0089] The above-mentioned polyurethane resin is mainly used for industrial applications as a urethane resin emulsion, and it may be a self-emulsifying type or a strengthened emulsifying type. However, from the viewpoints of water resistance and solvent resistance, it is preferably a self-emulsifying type polyurethane resin. Examples of the self-emulsifying type include anionic type, cationic type, and non-ionic type, and any of them may be used. Also, the polyurethane resin is not particularly limited, and examples thereof include polyether type, polyester type, polycarbonate type, etc.

[0090] The polyurethane resin can be commercially easily obtained, for example, products manufactured by Sanyo Chemical Industries, Ltd., trade names: Youcoat (registered trademark), Permalin (registered trademark), Youpren (registered trademark); products manufactured by Kusumoto Chemicals, Ltd., trade name: NeoRez (registered trademark); products manufactured by ADEKA Corporation, trade name: Adeka Bon Titer (registered trademark); products manufactured by Meisei Chemical Industry Co., Ltd., trade name: Pascol (registered trademark); products manufactured by DIC Corporation, trade name: Hydran (registered trademark), etc.

[0091] The above-mentioned polyurethane resin can be used alone or in combination of two or more.

[0092] The surfactant is not particularly limited, and examples thereof include anionic surfactants, cationic surfactants, non-ionic surfactants, amphoteric surfactants, fluorine-based surfactants, silicone-based surfactants, or acetylene glycol type surfactants, etc.

[0093] These surfactants may be used alone or in combination of two or more.

[0094] The anionic surfactant is not particularly limited, and examples thereof include sodium lauryl sulfate or sodium dodecylbenzenesulfonate, etc.

[0095] As the cationic surfactant described above, there is no particular limitation, but commercially available products can be used, or generally known ones can be separately manufactured and used.

[0096] As the nonionic surfactant described above, there is no particular limitation, but examples include polyvinylpyrrolidone and copolymers of polyvinylpyrrolidone. The average molecular weight of polyvinylpyrrolidone is preferably from 1,000 to 2,000,000, more preferably from 10,000 to 1,500,000. As the copolymer of polyvinylpyrrolidone, there is no particular limitation, but those having both a hydrophilic part and a hydrophobic part in the polymer chain are preferred. For example, graft copolymers of polyvinylpyrrolidone onto polyvinyl alcohol, or [vinylpyrrolidone-vinyl acetate] block copolymers, [vinylpyrrolidone-methyl methacrylate] copolymers, [vinylpyrrolidone-normal butyl methacrylate] copolymers, [vinylpyrrolidone-acrylamide] copolymers, etc. can be exemplified.

[0097] As the amphoteric surfactant described above, there is no particular limitation, but for example, betaine-type amphoteric surfactants can be mentioned. There is no particular limitation as the betaine-type amphoteric surfactant, but for example, alkyldimethylbetaine, lauryldimethylbetaine, stearyldimethylbetaine, or lauryldihydroxyethylbetaine, etc. can be mentioned.

[0098] As the fluorine-based surfactant described above, those having a perfluoroalkyl group are preferred. There is no particular limitation, but for example, perfluoroalkanes, perfluoroalkyl carboxylic acids, perfluoroalkyl sulfonic acids, or perfluoroalkyl ethylene oxide adducts, etc. can be mentioned.

[0099] The silicone surfactant is not particularly limited, and examples thereof include polyether-modified polydimethylsiloxane, polyether ester-modified polydimethylsiloxane, hydroxyl group-containing polyether-modified polydimethylsiloxane, acrylic group-containing polyether-modified polydimethylsiloxane, acrylic group-containing polyester-modified polydimethylsiloxane, perfluoropolyether-modified polydimethylsiloxane, perfluoropolyester-modified polydimethylsiloxane, or silicone-modified acrylic compounds.

[0100] The fluorosurfactant or silicone surfactant is effective in improving the flatness of the coating film as a leveling agent.

[0101] The monoamine compound is not particularly limited, and examples thereof include ammonia, methylamine, dimethylamine, ethylamine, triethylamine, normal-propylamine, isopropylamine, normal butylamine, tertiary butylamine, hexylamine, ethanolamine compounds (for example, aminoethanol, dimethylaminoethanol, methylaminoethanol, diethanolamine, N-methyldiethanolamine, triethanolamine), 3-amino-1,2-propanediol, 3-methylamino-1,2-propanediol, 3-dimethylamino-1,2-propanediol, 1,4-butanediamine, etc.

[0102] These monoamine compounds may be used alone or in combination of two or more.

[0103] The silane compounds described above are not particularly limited. For example, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane, etc. may be mentioned.

[0104] These silane compounds may be used alone or in combination of two or more.

[0105] The solvents described above are not particularly limited. For example, water, methanol, ethanol, propanol, butanol, methoxyethanol, ethoxyethanol, butoxyethanol, ethylene glycol, propylene glycol, butyl cellosolve, hexyl cellosolve, etc. may be mentioned. Alternatively, aprotic polar organic solvents such as dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide, 1-methyl-2-pyrrolidone, etc. may be used as the solvent. These solvents may be used alone or in combination of two or more.

[0106] By applying the conductive polymer solution of this embodiment to the capacitor body, an electrolytic capacitor provided with a conductive polymer film can be obtained. The conductive polymer film can be formed on the capacitor body as an outer layer containing the conductive polymer. In this specification, the capacitor body means an electrolytic capacitor body or a part thereof, and may particularly be a capacitor anode.

[0107] The application to the capacitor body is not particularly limited, and examples thereof include a casting method, a dipping method, a bar coating method, a dispenser method, a roll coating method, a gravure coating method, a flexographic printing method, a spray coating method, a spin coating method, an inkjet method, a spray coating method, a screen printing method, and the like.

[0108] The drying temperature after the application to the capacitor body is not particularly limited as long as it is at or below the temperature at which a uniform film can be obtained and the heat resistance temperature of the base material, but it is in the range of room temperature to 300 °C, preferably in the range of room temperature to 250 °C, and more preferably in the range of room temperature to 200 °C.

[0109] The drying atmosphere may be any of in the air, in an inert gas, in a vacuum, or under reduced pressure. From the viewpoint of suppressing the deterioration of the polymer film, it is preferably in an inert gas such as nitrogen or argon.

[0110] The film thickness of the outer layer containing the conductive polymer is not particularly limited, but is in the range of 1 to 1000 μm, preferably in the range of 3 to 100 μm, and more preferably in the range of 5 to 100 μm.

[0111] The outer layer containing the conductive polymer may be a part of a multilayer system forming the outer layer of the capacitor body. It is also possible for a further functional layer to exist on this polymer outer layer. In addition, an outer layer containing a plurality of conductive polymers may exist on the capacitor body.

[0112] In addition, since the conductive polymer film of the present embodiment can suppress leakage current, it can contribute to the improvement of energy efficiency. Thereby, it can contribute to the achievement of sustainable development goals (SDGs), such as Goal 7, "Ensure access to affordable, reliable, sustainable and modern energy for all" and the like.

[0113] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in 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.

Examples

[0114] Examples are shown below, but the present invention is not construed as being limited to these examples. The analytical instruments and measurement methods used in this example are listed below.

[0115] [Measurement of conductivity of A1] 2.0 ml of an aqueous solution containing 1.0% by weight of A1 described below was applied to a 50 mm square non-alkali glass plate, heated at 60 °C for 30 minutes on a hot plate in the atmosphere, and further heated at 200 °C for 60 minutes to obtain a film of A1.

[0116] The above A1 film was cut at intervals of 10 mm in the x direction and 10 mm in the y direction to expose the glass part, and the film thickness at the central part was measured. As the measuring device, DEKTAK XT manufactured by BRUKER was used.

[0117] For the above A1 film, the surface resistivity at the central part was measured. As the measuring device, a surface resistance measuring instrument Loresta GP MCP-T600 manufactured by Mitsubishi Chemical Corporation was used, and the measuring probe was ASP.

[0118] Based on the following formula, the conductivity was calculated from the film thickness and surface resistivity of the A1 film measured by the above measurement method. Conductivity [S / cm] = 10 4 / (Surface resistivity [Ω / sq] × Film thickness [μm]) [Evaluation of coating property] The evaluation of the coating property of the outer layer containing the conductive polymer on the capacitor body was determined by a scanning electron microscope. Good means a state in which the capacitor body is completely coated with the outer layer containing the conductive polymer and the film thickness is 5 μm or more. Poor means a state in which a part of the capacitor body is not coated with the outer layer containing the conductive polymer, or the capacitor body is completely coated but the film thickness is less than 5 μm. Below, a capacitor anode was used as the capacitor body.

[0119] Example 1 (Preparation of conductive polymer solution) According to a conventionally well-known manufacturing method, an aqueous solution (hereinafter abbreviated as A2) containing 2.0% by weight of 3-[(2,3-dihydrothieno[3,4-b]-[1,4]dioxin-2-yl)methoxy]-1-methyl-1-propanesulfonic acid polymer (a conductive polymer containing structural units represented by the following formulas (6) and (7), hereinafter abbreviated as A1) was prepared. The conductivity of the A1 was 300 S / cm. The weight average molecular weight of A1 was 13,500 in terms of standard polystyrene sulfonic acid sodium conversion. The viscosity of A2 was 60 mPa·s. The sodium ion content was 0.3 ppm, the iron ion content was 1.1 ppm, the chloride ion content was less than 1 ppm, and the sulfate ion was less than 50 ppm.

[0120]

Chemical formula

[0121] To 45.0 g of the aqueous solution of A2 in a glass container, 1.3 g of an aqueous solution containing 20% by weight of 1,4-diaminobutane was added while stirring, and the mixture was stirred at 20 °C for 1 hour to obtain the conductive polymer solution of Example 1. In the conductive polymer solution, the content of 1,4-diaminobutane was 0.29 parts by weight with respect to 1.0 part by weight of the conductive polymer of A1. The amount of the 1,4-diaminobutane is 1.00 times the molar amount of the polythiophene (A) charged.

[0122] Example 2 (Coating on a capacitor element using a conductive polymer solution) As a capacitor anode, a tantalum anode for a capacitor element (manufactured by High Purity Chemical Laboratory) having dimensions of 1.1 mm × 3.2 mm × 4.3 mm was immersed in the conductive polymer solution prepared in Example 1 for 30 seconds, and then the tantalum anode was lifted out of the conductive polymer solution to cut off the accompanying liquid (immersion step). Next, the lifted tantalum anode was dried at 150 °C for 10 minutes (drying step). The above immersion step and drying step were further repeated 4 times for the obtained tantalum anode (coating operation).

[0123] The coating property of the film formed on the tantalum anode was evaluated by a scanning electron microscope. As a result, the film thickness was 14 μm and the coating property was good.

[0124] Example 3 To 45.0 g of the aqueous solution of A2 described above, 0.2 g of an aqueous solution containing 20% by weight of 1,4-diaminobutane was added with stirring, and the mixture was stirred at 20°C for 1 hour to obtain the conductive polymer solution of Example 3. In the conductive polymer solution, the content of 1,4-diaminobutane is 0.044 parts by weight with respect to 1.0 part by weight of the conductive polymer of A1. The amount of 1,4-diaminobutane is 0.15 times the molar amount of the polythiophene (A) charged. Using the above conductive polymer solution, a coating operation was performed under the same conditions as in Example 2, and the film was evaluated. The evaluation results are shown in Table 1.

[0125] Example 4 To 45.0 g of the aqueous solution of A2 described above, 1.6 g of an aqueous solution containing 20% by weight of 1,8-diaminooctane was added with stirring, and the mixture was stirred at 20°C for 1 hour to obtain the conductive polymer solution of Example 4. In the conductive polymer solution, the content of 1,8-diaminooctane is 0.36 parts by weight with respect to 1.0 part by weight of the conductive polymer of A1. The amount of 1,8-diaminooctane is 0.76 times the molar amount of the polythiophene (A) charged. Using the above conductive polymer solution, a coating operation was performed under the same conditions as in Example 2, and the film was evaluated. The evaluation results are shown in Table 1.

[0126] Example 5 To 45.0 g of the above aqueous solution of A2, 0.3 g of an aqueous solution containing 20% by weight of 1,8-diaminooctane was added with stirring, and the mixture was stirred at 20 °C for 1 hour to obtain the conductive polymer solution of Example 5. In the conductive polymer solution, the content of 1,8-diaminooctane is 0.067 parts by weight with respect to 1.0 part by weight of the conductive polymer of A1. The amount of 1,8-diaminooctane is 0.14 times the molar amount of the polythiophene (A). Using the above conductive polymer solution, a coating operation was performed under the same conditions as in Example 2, and the film was evaluated. The evaluation results are shown in Table 1.

[0127] Example 6 To 45.0 g of the above aqueous solution of A2, 0.7 g of 1,10-diaminodecane was added with stirring, and the mixture was stirred at 20 °C for 5 hours to obtain the conductive polymer solution of Example 6. In the conductive polymer solution, the content of 1,10-diaminodecane is 0.78 parts by weight with respect to 1.0 part by weight of the conductive polymer of A1. The amount of 1,10-diaminodecane is 1.38 times the molar amount of the polythiophene (A). Using the above conductive polymer solution, a coating operation was performed under the same conditions as in Example 2, and the film was evaluated. The evaluation results are shown in Table 1.

[0128] Example 7 To 45.0 g of the above aqueous solution of A2, 10.0 g of an aqueous solution containing 20% by weight of 1,4-diaminobutane was added with stirring, and the mixture was stirred at 20 °C for 1 hour to obtain the conductive polymer solution of Example 7. In the conductive polymer solution, the content of 1,4-diaminobutane is 2.2 parts by weight with respect to 1.0 part by weight of the conductive polymer of A1. The amount of 1,4-diaminobutane is 7.72 times the molar amount of the polythiophene (A). Using the above conductive polymer solution, a coating operation was performed under the same conditions as in Example 2, and the film was evaluated. The evaluation results are shown in Table 1.

[0129] Example 8 To 45.0 g of the aqueous solution of A2 described above, 5.0 g of 1,10-diaminodecane was added with stirring, and the mixture was stirred at 20 °C for 5 hours to obtain the conductive polymer solution of Example 8. In the conductive polymer solution, the content of 1,10-diaminodecane is 5.6 parts by weight with respect to 1.0 part by weight of the conductive polymer of A1. The amount of the 1,10-diaminodecane is 9.88 times the molar amount of the polythiophene (A) charged. Using the conductive polymer solution described above, a coating operation was performed under the same conditions as in Example 2, and the film was evaluated. The evaluation results are shown in Table 1.

[0130] Comparative Example 1 Using the aqueous solution of A2 described above, a coating operation was performed under the same conditions as in Example 2, and the film was evaluated. The film thickness was less than 1 μm, and uncoated portions (voids) were confirmed here and there. The film state was poor.

[0131] Comparative Example 2 Using an aqueous solution containing 20% by weight of 1,4-diaminobutane, a coating operation was performed under the same conditions as in Example 2, and the film was evaluated. The film thickness was less than 1 μm, and uncoated portions (voids) were confirmed here and there. The film state was poor.

[0132] Comparative Example 3 To 45.0 g of the aqueous solution of A2 described above, 1.3 g of an aqueous solution containing 20% by weight of 1-aminobutane, which is a monoamine compound, was added with stirring, and the mixture was stirred at 20 °C for 1 hour to obtain the conductive polymer solution of Comparative Example 3. In the conductive polymer solution, the content of 1-aminobutane is 0.29 part by weight with respect to 1.0 part by weight of the conductive polymer of A1. Using the conductive polymer solution described above, a coating operation was performed under the same conditions as in Example 2, and the film was evaluated. The film thickness was less than 1 μm, and uncoated portions (voids) were confirmed here and there. The film state was poor.

[0133]

Table 1

[0134] As shown in Table 1, the films of Examples 2 to 8 using the conductive polymer solution of this embodiment containing a diamine compound showed good coatability and could be thickened. On the other hand, the films of Comparative Example 1 not containing a diamine compound, Comparative Example 2 not containing conductive polymer A1, and Comparative Example 3 containing a monoamine compound but not a diamine compound had poor coatability and a film thickness of less than 1 μm.

Industrial Applicability

[0135] This embodiment provides a conductive polymer solution for manufacturing an electrolytic capacitor capable of thickening an outer layer containing a conductive polymer formed on a capacitor anode and achieving good coating on corners and edges.

[0136] The conductive polymer solution of this embodiment can be used for solid electrolytes of electrolytic capacitors and the like. In addition, applications to antistatic agents, organic thin-film solar cells, organic ELs, electrochromic devices, transparent electrodes, transparent conductive films, thermoelectric conversion materials, chemical sensors, actuators, electromagnetic wave shielding materials, conductive paints, conductive inks, etc. can also be expected.

Claims

1. At least a structural unit represented by the following general formula (1) and a structural unit represented by the following general formula (2) 【Chemical Formula 1】 【Chemical Formula 2】 {In the above general formulas (1) and (2), R １ represents a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, or a halogen atom. m represents an integer of 1 to 6, and n represents 0 or 1.} A polythiophene (A) containing at least two or more of at least one structural unit selected from the group consisting of, and a diamine compound (B), wherein the diamine compound (B) is represented by the following general formula (3) 【Chemical Formula 3】 {In the above general formula (3), R 2, R 3, R 4, and R 5 each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms in total, or an alkyl group having 1 to 10 carbon atoms in total and having a substituent. R 6 represents an alkylene group having 1 to 20 carbon atoms in total, or an alkylene group having 1 to 20 carbon atoms in total and having a substituent.} A diamine compound represented by, and the following general formula (4) 【Chemical Formula 4】 {In the above general formula (4), R 2, R 3, R 4, and R 5 each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms in total, or an alkyl group having 1 to 10 carbon atoms in total and having a substituent. R 6 each independently represents an alkylene group having 1 to 20 carbon atoms in total, or an alkylene group having 1 to 20 carbon atoms in total and having a substituent. p represents an integer of 1 to 5.} A conductive polymer solution which is at least one selected from the group consisting of diamine compounds represented by.

2. The diamine compound (B) is represented by the following general formula (3') 【Chemical Formula 5】 {In the above general formula (3'), R ６represents an alkylene group having 2 to 12 carbon atoms in total, or an alkylene group having 2 to 12 carbon atoms in total and having a substituent.} a diamine compound represented by the following general formula (4'), and the following general formula (4') 【Chemical Formula 6】 {In the above general formula (4'), R ６ represents an alkylene group having 2 to 12 carbon atoms in total, or an alkylene group having 2 to 12 carbon atoms in total and having a substituent. p represents an integer of 1 to 5.} The conductive polymer solution according to claim 1, which is at least one selected from the group consisting of diamine compounds represented by the formula:

3. The conductive polymer solution according to claim 1 or 2, wherein m is 2 or 3.

4. The R １ is a methyl group, and the conductive polymer solution according to any one of claims 1 to 3.

5. The content of the polythiophene (A) is 0.01 to 10% by weight based on the total conductive polymer solution, and the conductive polymer solution according to any one of claims 1 to 4.

6. The weight ratio of the polythiophene (A) to the diamine compound (B) is 0.01 to 10 parts by weight of the diamine compound (B) with respect to 1 part by weight of the polythiophene (A), and the conductive polymer solution according to any one of claims 1 to 5.

7. A method for producing a conductive polymer film, comprising the step of applying the conductive polymer solution according to any one of claims 1 to 6 to a substrate and then drying to obtain a conductive polymer film.

8. At least a structural unit represented by the following general formula (1) and a structural unit represented by the following general formula (2) 【Chemical Formula 7】 【Chemical Formula 8】 {In the above general formulas (1) and (2), R １represents a hydrogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, or a halogen atom. m represents an integer of 1 to 6, and n represents 0 or 1.} comprises at least two or more structural units selected from the group consisting of polythiophene (A), and a diamine compound (B), wherein the diamine compound (B) is represented by the following general formula (3) 【Chemical Formula 9】 {In the above general formula (3), R2, R3, R4, and R5 each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms in total, or an alkyl group having 1 to 10 carbon atoms in total and having a substituent. R6 represents an alkylene group having 1 to 20 carbon atoms in total, or an alkylene group having 1 to 20 carbon atoms in total and having a substituent.} a diamine compound represented by the formula, and the following general formula (4) 【Chemical Formula 10】 {In the above general formula (4), R2, R3, R4, and R5 each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms in total, or an alkyl group having 1 to 10 carbon atoms in total and having a substituent. R6 each independently represents an alkylene group having 1 to 20 carbon atoms in total, or an alkylene group having 1 to 20 carbon atoms in total and having a substituent. p represents an integer of 1 to 5.} a conductive polymer film, which is at least one selected from the group consisting of diamine compounds represented by the formula.

9. An electrolytic capacitor comprising the conductive polymer film according to Claim 8.

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