JP7531356B2 - Manufacturing method of conductive powder - Google Patents

Description

The present invention relates to a conductive powder containing a π-conjugated conductive polymer and a manufacturing method thereof, a paint, and an electrode and a manufacturing method thereof.

π-conjugated conductive polymers, whose main chains are composed of π-conjugated systems, are basically poorly soluble in water, but a method is known in which a water-dispersible conductive complex is made by forming a complex with a polyanion having a hydrophilic anionic group. The formation of this conductive complex increases the conductivity. In addition, a method is known in which the water-dispersible anionic group of the conductive complex is reacted with an amine compound or an epoxy compound to hydrophobize it, thereby dispersing it in an organic solvent (see Patent Documents 1 and 2).

JP 2011-032382 A International Publication No. 2014/125827

The objective of Patent Documents 1 and 2 is to obtain a coating material in which a conductive complex is uniformly dispersed or dissolved in a dispersion medium at the molecular level.
When a conductive polymer is used as an electrode material for an energy device such as a battery, the conductive complex does not need to be dispersed at the molecular level, and may be easier to handle if the conductive complex is in an aggregated powder state. Therefore, the present inventors have investigated a method for obtaining a powder of the conductive complex.

The present invention provides a conductive powder and its manufacturing method, a paint, and an electrode and its manufacturing method that are useful as an electrode material for energy devices such as batteries.

[1] A conductive powder comprising: a conductive polymer powder containing a π-conjugated conductive polymer and a polyanion; and graphene, wherein a content ratio of the π-conjugated conductive polymer to the polyanion in the conductive polymer powder is, on a mass basis, from (1:0.5) to (1:1).
[2] The conductive powder according to [1], wherein a content ratio of the conductive polymer powder:the graphene is from (6:4) to (1:9) on a mass basis.
[3] The conductive powder according to [1] or [2], wherein the conductive polymer powder contains at least one of poly(3,4-ethylenedioxythiophene) and polystyrenesulfonic acid.
[4] The conductive powder according to any one of [1] to [3], wherein a part of the anion groups of the polyanion is modified by reacting with an amine compound.
[5] The conductive powder according to any one of [1] to [3], wherein a part of the anion groups of the polyanion is modified by reacting with an epoxy compound.
[6] A coating material comprising the conductive powder according to any one of [1] to [5] and a binder component.
[7] An electrode comprising the conductive powder according to any one of [1] to [5].
[8] A method for producing a conductive powder, comprising: a step of adding a catalyst and an oxidizing agent to a reaction liquid containing a monomer capable of forming a π-conjugated conductive polymer, a polyanion, and water, thereby oxidatively polymerizing the monomer to form a conductive polymer powder containing the π-conjugated conductive polymer and the polyanion; a step of separating the conductive polymer powder from the reaction liquid; and a step of mixing the separated conductive polymer powder with graphene to obtain a conductive powder, wherein a content ratio of the monomer:the polyanion in the reaction liquid is (1:0.5) to (1:1) on a mass basis.
[9] A method for producing a conductive powder, comprising: a step of adding a catalyst and an oxidizing agent to a reaction liquid containing a monomer capable of forming a π-conjugated conductive polymer, a polyanion, graphene, and water, thereby oxidatively polymerizing the monomer to form a conductive polymer powder containing the π-conjugated conductive polymer and the polyanion; and a step of separating the conductive polymer powder and the conductive powder containing the graphene from the reaction liquid, wherein a content ratio of the monomer:the polyanion in the reaction liquid is (1:0.5) to (1:1) on a mass basis.
[10] A method for producing a conductive powder, comprising: a step of adding a catalyst and an oxidizing agent to a reaction liquid containing a monomer capable of forming a π-conjugated conductive polymer, a polyanion, graphene, and water, thereby oxidatively polymerizing the monomer to form a conductive polymer powder containing the π-conjugated conductive polymer and the polyanion; a step of adding an amine compound to the reaction liquid containing the conductive polymer powder and the graphene and reacting the resulting mixture to precipitate a conductive powder containing the modified conductive polymer powder and the graphene; and a step of separating the conductive powder from the reaction liquid, wherein a content ratio of the monomer:polyanion in the reaction liquid is (1:0.5) to (1:1) on a mass basis.
[11] A method for producing a conductive powder, comprising: a step of adding a catalyst and an oxidizing agent to a reaction liquid containing a monomer capable of forming a π-conjugated conductive polymer, a polyanion, graphene, and water, thereby oxidatively polymerizing the monomer to form a conductive polymer powder containing the π-conjugated conductive polymer and the polyanion; a step of adding an epoxy compound to the reaction liquid containing the conductive polymer powder and the graphene and reacting the epoxy compound to precipitate a conductive powder containing the modified conductive polymer powder and the graphene; and a step of separating the conductive powder from the reaction liquid, wherein a content ratio of the monomer:the polyanion in the reaction liquid is (1:0.5) to (1:1) on a mass basis.
[12] A method for producing an electrode, comprising: applying the coating material according to [6] to at least a part of a substrate; curing the coating film formed on the substrate; and forming a conductive layer, thereby obtaining an electrode having the conductive layer on at least a part of the substrate.

The conductive layer produced using the conductive powder and paint of the present invention has excellent conductivity and is useful as an electrode for batteries, etc.

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

In this specification and claims, the lower and upper limits of the numerical ranges indicated with "~" are considered to be included in the numerical range.

<Conductive powder>
A first aspect of the present invention is a conductive powder comprising a conductive polymer powder containing a π-conjugated conductive polymer and a polyanion, and graphene, wherein a content ratio of the π-conjugated conductive polymer to the polyanion in the conductive polymer powder is from (1:0.5) to (1:1) on a mass basis.

<Conductive polymer powder>
The conductive polymer powder of this embodiment is an aggregate of conductive particles that includes a conductive complex having a π-conjugated conductive polymer and a polyanion.

[π-conjugated conductive polymer]
The π-conjugated conductive polymer may be any conductive organic polymer whose main chain is composed of a π-conjugated system, and examples thereof include polypyrrole-based conductive polymers, polythiophene-based conductive polymers, polyacetylene-based conductive polymers, polyphenylene-based conductive polymers, polyphenylenevinylene-based conductive polymers, polyaniline-based conductive polymers, polyacene-based conductive polymers, polythiophenevinylene-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.

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-iodothiophene). thiophene), 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-dodecyloxythiophene), oxythiophene), 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 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 preferable from the viewpoints of conductivity, transparency, and heat resistance.
The conductive particles may contain one type of π-conjugated conductive polymer, or two or more types of polymers.

(Polyanion)
The polyanion is a polymer having two or more monomer units each having an anionic group in the molecule. The anionic group of the polyanion functions as a dopant for the π-conjugated conductive polymer to improve the conductivity of the π-conjugated conductive polymer.
The anion group of the polyanion is preferably a sulfo group or a carboxy group.
Specific examples of such polyanions include polymers having a sulfo group, such as polystyrene sulfonic acid, polyvinyl sulfonic acid, polyallyl sulfonic acid, polyacrylic acid esters having a sulfo group, polymethacrylic acid esters having a sulfo group (e.g., poly(4-sulfobutyl methacrylate, polysulfoethyl methacrylate, polymethacryloyloxybenzenesulfonic acid), poly(2-acrylamido-2-methylpropanesulfonic acid), and 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-methylpropanecarboxylic acid), and 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, since they can provide higher electrical conductivity.
The polyanions may be used alone or in combination of two or more kinds.
The mass average molecular weight of the polyanion is preferably from 20,000 to 1,000,000, and more preferably from 100,000 to 500,000. The mass average molecular weight is the average molecular weight based on mass measured by gel permeation chromatography and calculated in terms of polystyrene.

The polyanion is doped into the π-conjugated conductive polymer to form a conductive complex having electrical conductivity. When the content ratio of the π-conjugated conductive polymer and the polyanion in the conductive complex is as follows, the conductive complex can form a conductive polymer powder.

The content ratio of the π-conjugated conductive polymer to the polyanion in the conductive complex is, on a mass basis, from (1:0.5) to (1:1), more preferably from (1:0.7) to (1:0.99), and even more preferably from (1:0.8) to (1:0.98).
When the content is at least the lower limit of the above range, the doping effect of the polyanion is sufficiently exhibited, and the conductivity of the conductive polymer powder formed by the conductive complex is further improved.
When the content is equal to or less than the upper limit of the above range, the conductive polymer powder has low dispersibility in water and can be easily precipitated in water while obtaining the doping effect of the polyanion.

In the polyanion of the conductive polymer powder of this embodiment, it is preferable that most or almost all of the anion groups are doped into the π-conjugated conductive polymer, and there are few or almost no excess anion groups that are not involved in the doping. By setting the content ratio of π-conjugated conductive polymer:polyanion within the above-mentioned preferred range, the excess anion groups can be reduced or almost eliminated.
The conductive polymer powder has a low or almost no excess anionic group, and is hydrophobic enough to easily precipitate in water. Furthermore, the conductive powder containing the conductive polymer powder can form an electrode that exhibits excellent battery properties.

When some of the polyanions in the conductive polymer powder of this embodiment have excess anion groups that are not involved in the doping, it is preferable that these excess anion groups are hydrophobically modified by reacting with an amine compound or an epoxy compound.

(Substituent A)
The substituent A that can be formed by reacting the excess anion group with an epoxy compound is represented, for example, by the following structural formula:
Although it is not necessarily easy to perform a detailed analysis of the modified conductive composite, it is presumed that the substituent (A) is a group represented by the following formula (A1) or a group represented by the following formula (A2).

［式（Ａ１）中、Ｒ^１１、Ｒ^１２、Ｒ^１３、及びＲ^１４はそれぞれ独立に、水素原子、又は任意の置換基である。］

[In formula (A1), R ¹¹ , R ¹² , R ¹³ , and R ¹⁴ each independently represent a hydrogen atom or any substituent.]

［式（Ａ２）中、ｍは２以上の整数であり、複数のＲ^１５、複数のＲ^１６、複数のＲ^１７、及び複数のＲ^１８はそれぞれ独立に、水素原子、又は任意の置換基であり、複数のＲ^１５は同一でも異なっていてもよく、複数のＲ^１６は同一でも異なっていてもよく、複数のＲ^１７は同一でも異なっていてもよく、複数のＲ^１８は同一でも異なっていてもよい。］

[In formula (A2), m is an integer of 2 or more, a plurality of R ^{15 s} , a plurality of R ^{16 s} , a plurality of R ^{17 s} , and a plurality of R ^{18 s} are each independently a hydrogen atom or any substituent, a plurality of R ^{15 s} may be the same or different, a plurality of R ^{16 s} may be the same or different, a plurality of R ^{17 s} may be the same or different, and a plurality of R ^{18 s} may be the same or different.]

In formula (A1) and formula (A2), the bond at the left end represents that the substituent (A) is substituted with a proton of an anionic group. Examples of the anionic group having a substituted proton include an anionic group having an active proton bonded to an oxygen atom, such as "-SO ₃ H".

In formula (A1), examples of the optional substituents of R ¹¹ , R ¹² , R ¹³ , and R ¹⁴ include an aliphatic hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and an aromatic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent. R ¹¹ and R ¹³ may be bonded to form a ring which may have a substituent. For example, there may be mentioned a case where R ¹¹ and R ¹³ are the above-mentioned hydrocarbon group, and a divalent hydrocarbon group obtained by removing any one hydrogen atom from the monovalent hydrocarbon group of R ¹¹ and a divalent hydrocarbon group obtained by removing any one hydrogen atom from the monovalent hydrocarbon group of R ¹³ are bonded to each other via the carbon atoms from which the hydrogen atoms have been removed to form a ring.
In particular, in formula (A1), it is preferable that R ¹¹ is a hydrogen atom or an alkoxyalkyl group having 10 to 16 carbon atoms, R ¹² is a hydrogen atom, R ¹³ is a hydrogen atom or an alkoxyalkyl group having 10 to 16 carbon atoms, and R ¹⁴ is a hydrogen atom.

In formula (A2), the optional substituents of R ¹⁵ , R ¹⁶ , R ¹⁷ and R ¹⁸ include an aliphatic hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and an aromatic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent. R ¹⁵ and R ¹⁷ may be bonded to form a ring which may have a substituent. Examples of the ring are the same as those mentioned above.
Among these, in formula (A2), it is preferable that R ¹⁵ is a hydrogen atom or an alkoxyalkyl group having 10 to 16 carbon atoms, R ¹⁶ is a hydrogen atom, R ¹⁷ is a hydrogen atom or an alkoxyalkyl group having 10 to 16 carbon atoms, and R ¹⁸ is a hydrogen atom.

In this specification, the term "optionally substituted" includes both the case where a hydrogen atom (-H) is replaced with a monovalent group and the case where a methylene group (-CH ₂ -) is replaced with a divalent group.
Examples of the monovalent group as a substituent include an alkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc.), a trialkoxysilyl group (a trimethoxysilyl group, etc.), and the like.
Examples of the divalent group as a substituent include an oxygen atom (-O-), -C(=O)-, -C(=O)-O-, etc., except for the case where two oxygen atoms are adjacent to each other.

In formula (A2), m is an integer of 2 or more, preferably 2 to 100, more preferably 2 to 50, and even more preferably 2 to 25. When m is equal to or greater than the lower limit, the hydrophobicity of the conductive composite is sufficiently high. When m is equal to or less than the upper limit, it is possible to prevent the hydrophobicity from becoming too high or the conductivity from decreasing.

The epoxy group-containing compound (epoxy compound) is a compound having one or more epoxy groups in one molecule. From the viewpoint of preventing aggregation or gelation during modification of the conductive composite, the epoxy compound is preferably a compound having one epoxy group in one molecule.
The epoxy compounds may be used alone or in combination of two or more.

Examples of monofunctional epoxy compounds having one epoxy group per molecule include ethylene oxide, propylene oxide, 2,3-butylene oxide, isobutylene oxide, 1,2-butylene oxide, 1,2-epoxyhexane, 1,2-epoxyheptane, 1,2-epoxypentane, 1,2-epoxyoctane, 1,2-epoxydecane, 1,3-butadiene monoxide, 1,2-epoxytetradecane, glycidyl methyl ether, 1,2-epoxyoctadecane, 1,2-epoxyhexadecane, ethyl glycidyl ether, glycidyl isopropyl ether, tert-butyl glycidyl ether, 1,2-epoxyeicosane, 2-(chloromethyl)-1,2-epoxypropane, glycidol, epichlorohydrin, epibromohydrin, and butyl glycidyl. ether, 1,2-epoxyhexane, 1,2-epoxy-9-decane, 2-(chloromethyl)-1,2-epoxybutane, 2-ethylhexyl glycidyl ether, 1,2-epoxy-1H,1H,2H,2H,3H,3H-trifluorobutane, allyl glycidyl ether, tetracyanoethylene oxide, glycidyl butyrate, 1,2-epoxycyclooctane, glycidyl methacrylate, 1,2-epoxycyclododecane, 1-methyl-1,2-epoxycyclohexane, 1,2-epoxycyclopentadecane, 1,2-epoxycyclopentane, 1,2-epoxycyclohexane, 1,2-epoxy-1H,1H,2H,2H,3H,3H-heptadecafluorobutane, 3,4-epoxytetrahydrofuran, glycidyl stearate, 3-glycidyloxypropyl trime methoxysilane, epoxysuccinic acid, glycidyl phenyl ether, isophorone oxide, α-pinene oxide, 2,3-epoxynorbornene, benzyl glycidyl ether, diethoxy(3-glycidyloxypropyl)methylsilane, 3-[2-(perfluorohexyl)ethoxy]-1,2-epoxypropane, 1,1,1,3,5,5,5-heptamethyl-3-(3-glycidyloxypropyl)trisiloxane, 9,10-epoxy-1,5-cyclododecadiene, glycidyl 4-tert-butylbenzoate, 2,2-bis(4-glycidyloxyphenyl)propane, 2-tert-butyl-2-[2-(4-chlorophenyl)]ethyloxirane, styrene oxide, glycidyl trityl ether, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-phenylpropylene oxide, cholesterol-5α,6α-epoxide, stilbene oxide, p-toluenesulfonate glycidyl, 3-methyl-3-phenylglycidic acid ethyl, N-propyl-N-(2,3-epoxypropyl)perfluoro-n-octylsulfonamide, (2S,3S)-1,2-epoxy-3-(tert-butoxycarbonylamino)-4-phenylbutane, 3-nitrobenzenesulfonate (R)-glycidyl, 3-nitrobenzenesulfonate-glycidyl, parthenolide, N-glycidylphthalimide, endrin, dieldrin, 4-glycidyloxycarbazole, 7,7-dimethyloctanoate [oxiranylmethyl], 1,2-epoxy-4-vinylcyclohexane, higher alcohol glycidyl ethers having 10 to 16 carbon atoms, etc.

The higher alcohol glycidyl ether is preferably one or more higher alcohol glycidyl ethers having 10 to 16 carbon atoms, more preferably one or more higher alcohol glycidyl ethers having 12 to 14 carbon atoms, even more preferably at least one of C12 (12 carbon atoms) higher alcohol glycidyl ether and C13 (13 carbon atoms) higher alcohol glycidyl ether, and particularly preferably a mixed C12 and C13 higher alcohol glycidyl ether.

Examples of polyfunctional epoxy compounds having two or more epoxy groups in one molecule include 1,6-hexanediol diglycidyl ether, 1,7-octadiene diepoxide, neopentyl glycol diglycidyl ether, 4-butanediol diglycidyl ether, 1,2:3,4-diepoxybutane, 1,2-cyclohexanedicarboxylate diglycidyl, triglycidyl isocyanurate neopentyl glycol diglycidyl ether, 1,2:3,4-diepoxybutane, polyethylene glycol diglycidyl ether, ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, propylene glycol diglycidyl diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, trimethylolpropane polyglycidyl ether, hydrogenated bisphenol A diglycidyl ether, hexahydrophthalic acid diglycidyl ester, glycerin polyglycidyl ether, diglycerin polyglycidyl ether, polyglycerin polyglycidyl ether, sorbitol-based polyglycidyl ether, ethylene oxide lauryl alcohol glycidyl ether, etc.

The epoxy compound preferably has a molecular weight of 50 or more and 2000 or less, since it has good reactivity with excess anionic groups. From the same viewpoint, the epoxy compound preferably has a carbon number of 2 or more and 100 or less, more preferably 5 or more and 80 or less, and even more preferably 10 or more and 50 or less.

(Substituent B)
The substituent B that can be formed by reacting the excess anion group with an amine compound is represented, for example, by the following structural formula:
Although it is not necessarily easy to perform a detailed analysis of the conductive composite, it is presumed that the substituent (B) is a group represented by the following formula (B).

-HN ⁺ R ²¹ R ²² R ²³ ...(B)
In formula (B), R ²¹ to R ²³ each independently represent a hydrogen atom or a hydrocarbon group which may have a substituent, provided that at least one of R ²¹ to R ²³ is a substituent. is a hydrocarbon group which may have the following formula:

In the substituent (B), the bond at the left end represents a bond between the negative charge of the anionic group and the positive charge of the amine compound. Examples of an anionic group that can be negatively charged include an anionic group having an oxygen atom to which an active proton can be bonded, such as "-SO ₃ ^- ".

In formula (B), R ²¹ to R ²³ each represent a hydrogen atom or a hydrocarbon group which may have a substituent. In formula (B), R ²¹ to R ²³ each represent a substituent derived from an amine compound.
Examples of the hydrocarbon group in formula (B) include an aliphatic hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and an aromatic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent.
Examples of the aliphatic hydrocarbon group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group.
Examples of the substituent that may replace the hydrogen of the aliphatic hydrocarbon group include a phenyl group and a hydroxyl group.
Examples of the aromatic hydrocarbon group include a phenyl group and a naphthyl group.
Examples of the substituent that may replace the hydrogen of the aromatic hydrocarbon group include an alkyl group having 1 to 5 carbon atoms, a hydroxyl group, and the like.

The amine compound is at least one selected from the group consisting of primary amines, secondary amines, and tertiary amines. One type of amine compound may be used alone, or two or more types may be used in combination.
Examples of primary amines include aniline, toluidine, benzylamine, and ethanolamine.
Examples of secondary amines include diethanolamine, dimethylamine, diethylamine, dipropylamine, diphenylamine, dibenzylamine, and dinaphthylamine.
Examples of tertiary amines include triethanolamine, trimethylamine, triethylamine, tripropylamine, tributylamine, trihexylamine, trioctylamine, triphenylamine, tribenzylamine, and trinaphthylamine.
Among the above amine compounds, tertiary amines are preferred because they can easily hydrophobize the conductive composite, and at least one of trioctylamine and tributylamine is more preferred.

The amine compound preferably has a substituent on the nitrogen atom having 4 or more carbon atoms, and more preferably has a substituent on the nitrogen atom having 6 or more carbon atoms.

(Substituent C)
When the amine compound reacted with the excess anion group is a heterocyclic aromatic amine, the substituent C formed by the reaction therewith is represented, for example, by the following structural formula:

-HN ⁺ R ²⁴ ...(C)
[In formula (C), N ⁺ R ²⁴ represents a heterocyclic aromatic amine containing a nitrogen atom that is positively charged due to the addition of a proton.]
Here, the heterocyclic aromatic amine refers to a cyclic amine compound containing a nitrogen atom constituting an aromatic ring, and the hydrogen atom bonded to the amine compound may be optionally substituted.

In formula (C), the bond at the left end represents a bond between the negative charge of the anionic group and the positive charge of the heterocyclic aromatic amine. Examples of an anionic group that can be negatively charged include an anionic group having an oxygen atom to which an active proton can be bonded, such as "-SO ₃ ^- ".

If the heterocyclic aromatic amine is too strongly basic, the conductivity of the modified conductive composite may decrease, so among heterocyclic aromatic amines, imidazole-based amines, which have a weak basicity, are preferred. Here, imidazole-based amines refer to compounds having an imidazole ring, and the hydrogen atom bonded to the imidazole ring may be optionally substituted.

Examples of substituents that may optionally substitute hydrogen atoms on the imidazole ring include hydroxyl groups, alkyl groups having 1 to 6 carbon atoms, alkenyl groups having 2 to 6 carbon atoms, and aryl groups having 6 to 12 carbon atoms. The hydrogen atoms constituting these substituents may be substituted with hydroxyl groups or cyano groups. Furthermore, the divalent or trivalent groups constituting these substituents may be substituted with -C(=O)-, -C(=O)-O-, -N=, etc. Furthermore, when there are two or more substituents substituting hydrogen atoms on the imidazole ring, these substituents may be bonded together to form a ring.

Examples of the imidazole-based amines include imidazole, 2-methylimidazole, 2-propylimidazole, N-methylimidazole, 1-(2-hydroxyethyl)imidazole, 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 1-acetylimidazole, 2-aminobenzimidazole, 2-amino-1-methylbenzimidazole, 2-hydroxybenzimidazole, and 2-(2-pyridyl)benzimidazole.
Among these, imidazole is preferred because it has good reactivity with the anion group of the conductive complex and is inexpensive.

The electrical conductivity (unit: S/cm) of the conductive polymer powder of this embodiment is preferably 0.1 to 100, more preferably 0.3 to 100, even more preferably 1 to 100, particularly preferably 2 to 100, and most preferably 3 to 100.
A higher electrical conductivity is preferable because the electrical conductivity of the conductive polymer powder is increased accordingly.
The upper limit of the electrical conductivity is not particularly limited, and the above range of 100 or less is merely a guideline.
The electrical conductivity of the conductive polymer powder of this embodiment was measured using a molded product obtained by compressing the conductive polymer powder as a sample.

The number average particle size of the conductive polymer powder of this embodiment is preferably 0.1 μm or more and 100 μm or less, more preferably 0.5 μm or more and 50 μm or less, and even more preferably 1 μm or more and 10 μm or less.
When the content is at least the lower limit of the above range, handling as a powder becomes easier.
When it is equal to or less than the upper limit of the above range, the dispersibility of the conductive polymer powder in the conductive powder is further improved.
The number average particle size of the conductive polymer powder of this embodiment is a number-based average particle size measured using a dynamic light scattering particle size distribution measuring device.

The conductive polymer powder of this embodiment may contain Fe (iron) atoms. The Fe content relative to the total mass of the conductive polymer powder is, for example, preferably 0.5 mass% or less, more preferably 0.2 mass% or less, and even more preferably 0.1 mass% or less. The Fe content is most preferably substantially 0 mass%.
When the content is equal to or less than the upper limit of the above range, the impurity Fe is small, and therefore the conductive powder containing the conductive polymer powder can form an electrode that exhibits excellent battery characteristics.
The Fe content in the conductive polymer powder is a value measured by fluorescent X-ray analysis.

The conductive polymer powder of this embodiment may contain water, but the smaller the water content, the more preferable. The water content relative to the total mass of the conductive polymer powder is, for example, preferably 20 mass% or less, more preferably 10 mass% or less, and even more preferably 5 mass% or less. The water content is most preferably substantially 0 mass%.
When the content is equal to or less than the upper limit of the above range, aggregation of the conductive polymer powder can be suppressed when the conductive polymer powder is mixed with a non-aqueous material, for example, a binder component.
The water content in the conductive polymer powder is a value measured by the Karl Fischer method.

The content of the conductive polymer powder in the conductive powder of this embodiment is, for example, preferably 5 to 90 mass%, more preferably 10 to 50 mass%, and even more preferably 10 to 30 mass%, relative to the total mass of the conductive polymer powder and the graphene being 100 mass%.
When the content is within the above range, when used as an electrode material, an electrode having excellent electrical conductivity and battery characteristics can be formed.

[Graphene]
The graphene contained in the conductive powder of this embodiment is a known conductive carbon material and is commercially available. The graphene may have a functional group containing an atom other than a carbon atom. Known examples of such functional groups include a carboxy group, an amino group, an epoxy group, and a hydroxyl group. From the viewpoint of obtaining a conductive powder with excellent conductivity, it is preferable that the graphene has one or more of the functional groups.
The graphene included in this embodiment may be of one type or of two or more types.

The graphene contained in the conductive powder of this embodiment may form a ternary reaction product of graphene, conductive polymer powder, and the amine compound or epoxy compound. The ternary reaction product can be obtained by the manufacturing method (2) described later, and has excellent electrical conductivity as shown in the examples described later. It is preferable that the graphene constituting the ternary reaction product has a functional group containing an atom other than the carbon atom as described above, since the electrical conductivity is further improved.

The content of graphene in the conductive powder of this aspect is, for example, preferably 10 mass% or more and 95 mass% or less, more preferably 60 mass% or more and 90 mass% or less, and even more preferably 70 mass% or more and 90 mass% or less, when the total mass of the conductive polymer powder and the graphene is 100 mass%.
When the content is within the above range, when used as an electrode material, an electrode having excellent electrical conductivity and battery characteristics can be formed.

<Content ratio of each component>
The content ratio of the conductive polymer powder:graphene in the conductive powder of this embodiment is, on a mass basis, preferably from (6:4) to (1:9), more preferably from (5:5) to (1:9), even more preferably from (4:6) to (1:9), particularly preferably from (1:7) to (1:9), and most preferably from (1:8) to (1:9).
When the content is within the above range, when used as an electrode material, an electrode having excellent electrical conductivity can be formed.

The total mass of the conductive polymer powder and the graphene relative to the total mass of the conductive powder of this embodiment is preferably 70 mass% or more and 100 mass% or less, more preferably 80 mass% or more and 100 mass% or less, and even more preferably 90 mass% or more and 100 mass% or less.
When the content is within the above range, when used as an electrode material, an electrode having excellent electrical conductivity can be formed.

[Conductive assistant]
The conductive powder of this embodiment may contain a conductive assistant other than the conductive polymer powder and graphene described above.
Examples of the conductive assistant include known conductive assistants added to electrode active materials of lithium ion secondary batteries, specifically, carbon materials, metal particles, and the like.
Examples of the carbon material include carbon black, graphite, vapor-grown carbon fiber, carbon nanofiber, and carbon nanotube.
Examples of the metal particles include silver particles, copper particles, gold particles, and aluminum particles.
The conductive assistant included in this embodiment may be one type or two or more types.

The content of the conductive assistant relative to the total mass of the powder composition of this embodiment can be, for example, 0% by mass or more and 10% by mass or less.

(Other optional ingredients)
The conductive powder of this embodiment may contain any component other than the conductive polymer powder, graphene, and conductive assistant described above. Specific examples of the optional components include inorganic compounds (excluding carbon materials and metal particles).
Examples of inorganic compounds include silica, silica-alumina, glass, calcium carbonate, calcium hydroxide, talc, alumina, titania, zirconia, magnesium hydroxide, aluminum hydroxide, hydrotalcite, and mica.

The content of the other optional components relative to the total mass of the powder composition of this embodiment can be, for example, 0% by mass or more and 10% by mass or less.

<Paint>
A second aspect of the present invention is a coating material containing the conductive powder of the first aspect and a binder component.

(Binder Component)
The binder component is a resin or a precursor thereof other than the π-conjugated conductive polymer and the polyanion, and is a thermoplastic resin or a curable monomer or oligomer that is cured when the conductive layer is formed. The thermoplastic resin becomes the binder resin as it is, and the curable monomer or oligomer becomes the resin formed by curing.
The paint of this embodiment may contain one type of binder component or two or more types of binder components.

Specific examples of binder resins derived from binder components include epoxy resins, acrylic resins (acrylic compounds), polyester resins, polyurethane resins, polyimide resins, polyether resins, melamine resins, silicones, etc.

The curable monomer or oligomer may be a thermosetting monomer or oligomer, or a photocurable monomer or oligomer. Here, the oligomer refers to a polymer having a mass average molecular weight of less than 10,000.
Examples of the curable monomer include an acrylic monomer (acrylic compound), an epoxy monomer, an organosiloxane, etc. Examples of the curable oligomer include an acrylic oligomer (acrylic compound), an epoxy oligomer, a silicone oligomer (curable silicone), etc.
When an acrylic monomer or an acrylic oligomer is used as the binder component, it can be easily cured by heating or irradiating with light.

When a curable monomer or oligomer is included, it is preferable to further include a curing catalyst. For example, when a thermosetting monomer or oligomer is included, it is preferable to include a thermal polymerization initiator that generates radicals by heating, and when a photocurable monomer or oligomer is included, it is preferable to include a photopolymerization initiator that generates radicals by light irradiation.

The content ratio of the binder component in the coating material of this embodiment can be, for example, 10 parts by mass or more and 10,000 parts by mass or less, preferably 100 parts by mass or more and 5,000 parts by mass or less, more preferably 200 parts by mass or more and 3,000 parts by mass or less, and even more preferably 300 parts by mass or more and 1,500 parts by mass or less, relative to 100 parts by mass of the conductive polymer powder.
When the content is equal to or greater than the lower limit of the above range, the film-forming properties and film strength can be improved when the coating material of this embodiment is applied to a film substrate or the like.
When the content is equal to or less than the upper limit of the above range, a decrease in electrical conductivity due to a decrease in the content ratio of the conductive polymer powder can be suppressed.

The paint of this embodiment may contain a dispersion medium for dilution. The dispersion medium may be water, an organic solvent, or a mixture of water and an organic solvent.

Examples of the organic solvent include alcohol-based solvents (alcohols), ether-based solvents, ketone-based solvents, and nitrogen atom-containing solvents.
Examples of alcohol-based solvents include methanol, ethanol, 1-propanol, 2-propanol (isopropanol), 2-methyl-2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol, allyl alcohol, ethylene glycol, propylene glycol, propylene glycol monomethyl ether, and ethylene glycol monomethyl ether.
Examples of the ether solvent include diethyl ether, dimethyl ether, propylene glycol dialkyl ether, and diethylene glycol diethyl ether.
Examples of the ketone solvent include diethyl ketone, methyl propyl ketone, methyl butyl ketone, methyl isopropyl ketone, methyl isobutyl ketone, methyl amyl ketone, diisopropyl ketone, methyl ethyl ketone, acetone, and diacetone alcohol.
Examples of the nitrogen atom-containing solvent include N-methylpyrrolidone, dimethylacetamide, and dimethylformamide.
The organic solvent contained in the coating material of this embodiment may be one type or two or more types.

(Other additives)
The coating material of this embodiment may contain additives other than the binder component and the dispersion medium.
Examples of the additives include a surfactant, an inorganic conductive agent, an antifoaming agent, an antioxidant, and an ultraviolet absorbing agent.
However, the additive is something other than the above-mentioned π-conjugated conductive polymer, polyanion, graphene, and conductive assistant.
The surfactant may be a nonionic, anionic or cationic surfactant, with the nonionic surfactant being preferred from the standpoint of storage stability. A polymer surfactant such as polyvinylpyrrolidone may also be added.
The antifoaming agent includes silicone resin, polydimethylsiloxane, silicone oil, and the like.
Examples of the antioxidant include phenol-based antioxidants, amine-based antioxidants, phosphorus-based antioxidants, sulfur-based antioxidants, and sugars.
Examples of the ultraviolet absorber include benzotriazole-based ultraviolet absorbers, benzophenone-based ultraviolet absorbers, salicylate-based ultraviolet absorbers, cyanoacrylate-based ultraviolet absorbers, oxanilide-based ultraviolet absorbers, hindered amine-based ultraviolet absorbers, and benzoate-based ultraviolet absorbers.

When the paint of this embodiment contains the other additives, the content ratio is appropriately determined depending on the type of additive, but can be, for example, in the range of 0.001 parts by mass to 5 parts by mass per 100 parts by mass of conductive powder.

Electrodes
A third aspect of the present invention is an electrode comprising the conductive powder of the first aspect.
The shape of the electrode is not particularly limited, and examples thereof include known electrode shapes such as a plate, sheet, film, rod, and column.
The average thickness of the plate-, sheet- or film-like electrode is, for example, preferably 0.01 μm or more and 1000 μm or less, and more preferably 0.1 μm or more and 100 μm or less, from the viewpoint of achieving both a reduction in electrical resistance and a reduction in the thickness of the electrode.
The average thickness of a plate-, sheet-, or film-like electrode is the average value of thickness measurements taken at 10 or more randomly selected locations on a cross section of the electrode observed using a magnifying observation means such as a measuring microscope.
The electrode of this embodiment may be supported by a base material such as a film or substrate, or may be an independent electrode.
When the electrode of this embodiment is used as an electrode for a lithium ion secondary battery, it may be either a positive electrode or a negative electrode.

<Electrode manufacturing method>
Examples of methods for producing the electrode of this embodiment include a method of forming the conductive powder of the first embodiment into an electrode of a desired shape, and a method of applying the coating material of the second embodiment to a desired substrate and drying it to form an electrode layer (conductive layer) containing the conductive powder of the first embodiment on the surface of the substrate.
The method for molding the conductive powder of the first embodiment is not particularly limited, and for example, the conductive powder of the first embodiment may be kneaded with a binder contained in a known electrode active material of a lithium ion secondary battery to obtain a pellet, and the pellet may be molded in a molding die or the like or may be extrusion molded. Alternatively, the conductive powder may be filled into a mold and compressed to form an electrode having a three-dimensional shape that reflects the shape of the mold.
As the substrate to which the coating material of the second embodiment is applied, a substrate supporting an electrode active material layer of a known battery can be applied, for example, a metal material such as a metal foil or a metal plate. For example, copper foil, aluminum foil, stainless steel plate, etc. may be used. Also, a known resin film or resin plate may be used as the substrate. The coating method is not particularly limited, and a conventional method may be applied.

<Batteries>
It is also possible to manufacture a battery or a capacitor equipped with the electrode of this embodiment.
The battery may be a primary battery or a secondary battery. The form of the battery is not particularly limited, and examples of the battery include known battery forms such as a dry battery, an electrode-stacked laminate battery, and a button battery.
The battery generally includes a positive electrode, a negative electrode, and an electrolyte. The electrode in this embodiment may be a positive electrode or a negative electrode. The positive electrode and the negative electrode in the battery are preferably insulated from each other by a separator such as a nonwoven fabric.
The battery is preferably a lithium ion secondary battery.

<Method of manufacturing conductive film>
Another aspect related to the present invention is a method for producing a conductive film, comprising applying the coating material of the second aspect to at least one surface of a film substrate, curing the coating film formed on the film substrate, and forming a conductive layer, thereby obtaining a conductive film having the conductive layer formed on at least a portion of the substrate.
The conductive layer may be an electrode layer, and the conductive film may be an electrode supported on a film substrate.

(Film substrate)
The film substrate may be, for example, a plastic film.
Examples of the resin for film substrate constituting the plastic film 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-based elastomer, polyester-based elastomer, polyethersulfone, polyetherimide, polyetheretherketone, polyphenylene sulfide, polyimide, cellulose triacetate, cellulose acetate propionate, etc. Among these resins for film substrate, polyethylene terephthalate is preferred because it is inexpensive and has excellent mechanical strength.

The resin for the film substrate may be either amorphous or crystalline.
The film substrate may be either unstretched or stretched.
The film substrate may be subjected to a surface treatment such as a corona discharge treatment, a plasma treatment, or a flame treatment in order to further improve the adhesion of the conductive layer formed from the conductive polymer-containing liquid.

The average thickness of the film substrate is preferably 5 μm or more and 500 μm or less, and more preferably 20 μm or more and 200 μm or less. If the average thickness of the film substrate is equal to or more than the lower limit, the film is less likely to break, and if the average thickness is equal to or less than the upper limit, the film can have sufficient flexibility.
The thickness of the film substrate is determined by measuring the thickness at any ten points and averaging the measured values.

Methods for applying the coating material to a film substrate include, for example, methods using a coater such as a gravure coater, roll coater, curtain flow coater, spin coater, bar coater, reverse coater, kiss coater, fountain coater, rod coater, air doctor coater, knife coater, blade coater, cast coater, or screen coater; methods using a sprayer such as an air spray, airless spray, or rotor dampening; and immersion methods such as dipping.

The coating film made of the coating material applied onto the film substrate is dried and cured to obtain a conductive film having a conductive layer formed thereon.
Methods for drying the coating film include heat drying, vacuum drying, etc. Heat drying can be performed by a conventional method such as hot air heating or infrared heating.
When heat drying is applied, the heating temperature is appropriately set depending on the dispersion medium used, but is usually within the range of 50° C. to 150° C. Here, the heating temperature is the set temperature of the drying device.

When the coating material contains a thermosetting monomer or oligomer as a binder component, the coating film can be heated to harden the binder component, thereby obtaining a conductive film having a conductive layer formed thereon.
When the coating material contains a photocurable monomer or oligomer as a binder component, the coating film can be irradiated with ultraviolet light or electron beams to cure the binder component, thereby obtaining a conductive film having a conductive layer formed thereon.

<Conductive film>
Another aspect related to the present invention is a conductive film having a film substrate and a conductive layer provided on at least one surface of the film substrate, the conductive layer containing the conductive polymer powder of the first aspect. The conductive film of this aspect can be produced by the production method described above.
The conductive layer may be an electrode layer, and the conductive film may be an electrode supported on a film substrate.

(Conductive Layer)
The average thickness of the conductive layer provided on at least one surface of the film substrate is, for example, preferably 1 μm or more and 50 μm or less, and more preferably 2 μm or more and 10 μm or less.
When the average thickness of the conductive layer is equal to or greater than the lower limit, a sufficiently high conductivity can be exhibited, and when the average thickness is equal to or less than the upper limit, the conductive layer can be easily formed.

As an indicator of good conductivity, the conductive layer preferably has a surface resistance value of 1×10 ⁴ Ω/□ to 1×10 ¹⁰ Ω/□, more preferably 1×10 ⁴ Ω/□ to 1×10 ⁹ Ω/□, and even more preferably 1×10 ⁴ Ω/□ to 1×10 ⁸ Ω/□.

<<Method for producing conductive polymer powder (1)>>
A fourth aspect of the present invention is a method for producing a conductive powder, comprising: a step of adding a catalyst and an oxidizing agent to a reaction liquid containing a monomer capable of forming a π-conjugated conductive polymer, a polyanion, and water, thereby oxidatively polymerizing the monomer to form a conductive polymer powder containing the π-conjugated conductive polymer and the polyanion (polymerization step); a step of separating the conductive polymer powder from the reaction liquid (separation step); and a step of mixing the separated conductive polymer powder with graphene to obtain a conductive powder (mixing step).
The content ratio of the monomer to the polyanion in the reaction solution is (1:0.5) to (1:1) on a mass basis.

(Polymerization process)
In this process, an aqueous solution (reaction solution) containing the monomer and the polyanion in a specific content ratio is prepared, and the monomer is polymerized to form a π-conjugated conductive polymer. In the reaction solution, the polyanion is naturally doped into the π-conjugated conductive polymer, and a conductive polymer powder containing a conductive complex consisting of the π-conjugated conductive polymer and the polyanion is formed. The content ratio (mass basis) of the π-conjugated conductive polymer:polyanion contained in the formed conductive complex is the same as the ratio of the content of the monomer contained in the aqueous solution immediately before the start of polymerization to the content of the polyanion. In other words, the content ratio of the monomer and the polyanion blended in the reaction solution is reflected in the content ratio of the π-conjugated conductive polymer and the polyanion in the formed conductive complex and conductive polymer powder.

The content ratio of the monomer to the polyanion in the reaction solution immediately before the start of polymerization is, on a mass basis, from (1:0.5) to (1:1), more preferably from (1:0.7) to (1:0.99), and even more preferably from (1:0.8) to (1:0.98).
When the content is equal to or more than the lower limit of the above range, the doping effect of the polyanion is sufficiently exhibited, and a conductive polymer powder having better conductivity can be obtained.
When the content is equal to or less than the upper limit of the above range, it is possible to obtain the doping effect of the polyanion, while forming a conductive polymer powder that has low dispersibility in water and can be easily precipitated.

In this step, the catalyst contained in the reaction solution is not particularly limited as long as it polymerizes the monomer, and examples thereof include transition metal compounds such as ferric chloride, ferric sulfate, ferric nitrate, and cupric chloride.
It is preferable to contain an oxidizing agent together with the catalyst. The oxidizing agent can return the reduced catalyst to its original oxidized state. Examples of the oxidizing agent include persulfates such as ammonium persulfate, sodium persulfate, and potassium persulfate.
When a catalyst containing Fe (iron) is used as the catalyst, Fe derived from the catalyst may be contained in the conductive polymer powder.

The content of the monomer contained in the reaction liquid immediately before the start of polymerization is, for example, preferably 0.1 mass % or more and 20 mass % or less, more preferably 0.3 mass % or more and 10 mass % or less, and even more preferably 0.5 mass % or more and 5 mass % or less, relative to the total mass of the reaction liquid.
When the concentration is at least the lower limit of the above range, the conductive polymer powder formed can be easily separated.
When the content is equal to or less than the upper limit of the above range, the polymerization reaction can be stably carried out, so that the formation of a complex with the polyanion present in the reaction system can be stably carried out, and a high-quality conductive polymer powder having high conductivity can be easily obtained.

It is preferable that the content of the polyanion contained in the reaction solution immediately before the start of polymerization is set based on the content ratio to the monomer.

The content of the catalyst contained in the reaction liquid immediately before the start of polymerization is, for example, preferably 0.01 mass % or more and 3 mass % or less, more preferably 0.1 mass % or more and 2 mass % or less, and even more preferably 0.3 mass % or more and 1 mass % or less, relative to the total mass of the reaction liquid.
When it is at least the lower limit of the above range, the conductive polymer powder can be easily formed.
When the content is equal to or less than the upper limit of the above range, the polymerization reaction can be stably carried out, so that the formation of a complex with the polyanion present in the reaction system can be stably carried out, and a high-quality conductive polymer powder having high conductivity can be easily obtained.

In order to promote the polymerization reaction, the reaction liquid may be heated and stirred to cause the reaction. The heating temperature of the reaction liquid may be, for example, 60 to 100° C.
When the content is equal to or more than the lower limit of the above range, the polymerization reaction can be sufficiently promoted.
When the content is equal to or less than the upper limit of the above range, deterioration of the π-conjugated conductive polymer due to heat can be suppressed.
The reaction time at the heating temperature in the above range can be, for example, about 1 to 10 hours.

(Precipitation process)
A precipitation step may be provided between the polymerization step and the recovery step. In this step, the method for precipitating the conductive polymer powder in the reaction liquid after the polymerization reaction of the monomer is not particularly limited, and examples thereof include a method of leaving the reaction liquid after the reaction at rest, a method of slowly stirring the reaction liquid after the reaction, a method of cooling the reaction liquid after the reaction to about -20°C to 4°C, a method of adding an amine compound or an epoxy compound to the reaction liquid, and the like. In any method, natural precipitation can be achieved due to the conductive polymer powder's property of being difficult to dissolve in water.

By adding an amine compound or an epoxy compound to the reaction liquid after the polymerization reaction, the amine compound or the epoxy compound reacts with the excess anion groups of the conductive complex formed after the polymerization reaction, and the excess anion groups are modified to increase the hydrophobicity of the conductive complex, making it easier to precipitate the conductive complex in the reaction liquid.

The explanation of the amine compound and epoxy compound added to the reaction liquid is the same as that of the first embodiment, so the overlapping explanation will be omitted. The type of amine compound or epoxy compound added to the reaction liquid may be one type or two or more types.

The amount of the amine compound added to the reaction liquid is preferably 100 parts by mass or more and 10,000 parts by mass or less, more preferably 200 parts by mass or more and 6,000 parts by mass or less, and even more preferably 300 parts by mass or more and 3,000 parts by mass or less, relative to 100 parts by mass of the conductive complex. If the amount is equal to or more than the lower limit of the above range, the hydrophobicity of the conductive complex is sufficiently improved, and the precipitated conductive complex floats in the upper layer of the reaction liquid, so that it can be recovered with a high yield as a conductive polymer powder. If the amount is equal to or less than the upper limit of the above range, it is possible to suppress a decrease in conductivity due to modification of the conductive complex.

The amount of epoxy compound added to the reaction liquid is preferably 100 parts by mass or more and 10,000 parts by mass or less, more preferably 200 parts by mass or more and 6,000 parts by mass or less, and even more preferably 300 parts by mass or more and 3,000 parts by mass or less, relative to 100 parts by mass of the conductive complex. If the amount is equal to or more than the lower limit of the above range, the hydrophobicity of the conductive complex is sufficiently improved, and the precipitated conductive complex settles to the lower layer of the reaction liquid, so that it can be recovered with a high yield as a conductive polymer powder. If the amount is equal to or less than the upper limit of the above range, it is possible to suppress a decrease in conductivity due to modification of the conductive complex.

An organic solvent may be added before, simultaneously with, or after the addition of the amine compound or epoxy compound to the reaction liquid. The organic solvent is preferably a water-soluble organic solvent. Examples of the water-soluble organic solvent include alcohol-based solvents, ketone-based solvents, and ester-based solvents. One type of water-soluble organic solvent may be added, or two or more types may be added.

(Isolation process)
The separation step is a step of separating and recovering the conductive polymer powder containing the conductive complex formed in the reaction solution from the reaction solution. Examples of the separation method include a method of allowing the conductive polymer powder to naturally settle at the bottom of a container containing the reaction solution and removing the supernatant, a method of sucking and recovering the conductive polymer powder floating in the upper layer of the reaction solution, a method of filtering the reaction solution to obtain the conductive polymer powder on a filter, a method of forming pellets of the conductive polymer powder at the bottom of a container containing the reaction solution by centrifugation, and a method of spraying the reaction solution into a gas and drying it to obtain a dried conductive polymer powder.
Among these recovery methods, the method of recovering by natural precipitation or suspension is preferred because it is possible to easily obtain a conductive polymer powder with few impurities, excellent conductivity, and excellent flowability.

The conductive polymer powder immediately after recovery from the reaction liquid is preferably washed with water or an organic solvent because the reaction liquid containing the catalyst, oxidant, etc. is attached to the conductive polymer powder. Specifically, for example, the conductive polymer powder is added to a washing liquid consisting of water or an organic solvent, stirred, and then precipitated again, thereby recovering the conductive polymer powder from the washing liquid.
The organic solvent is preferably at least one selected from isopropyl alcohol, methanol, and acetone, because it is difficult for the conductive polymer powder to dissolve therein and has excellent cleaning power.

The conductive polymer powder obtained in this process can be dried to produce a dry powder that is easy to handle. There are no particular limitations on the drying method, and any known method for drying powder can be used.

The conductive polymer powder obtained in this process may be pulverized to a desired particle size. The pulverization method is not particularly limited, and examples include a method of grinding and pulverizing using a mortar, a method of grinding using a pulverizer, etc. Examples of pulverizers include a homogenizer, a ball mill, a bead mill, a roller mill, a jet mill, and a hammer mill.

The method for grinding the conductive polymer powder may be a wet method in which the conductive polymer powder is ground in a dispersion medium, or a dry method in which the conductive polymer powder is ground without a dispersion medium. The wet method is preferred in that it can easily produce a conductive polymer powder having a number average particle size in the range of 0.1 μm to 100 μm. When the wet method is used, the conductive polymer powder is obtained in a state where it is dispersed in the dispersion medium. The dispersion medium used for the wet grinding preferably contains one or more selected from isopropyl alcohol, methanol, and acetone. By using these preferred dispersion media, it is possible to more easily produce a conductive polymer powder having a number average particle size in the range of 0.1 μm to 100 μm without impairing the conductivity of the conductive polymer powder.

By using the steps described above, the conductive polymer powder contained in the conductive powder of the first embodiment can be easily produced.

(Mixing process)
In this step, the conductive polymer powder obtained in each of the above steps, graphene, and, if necessary, other optional components are mixed in a desired ratio to obtain a conductive powder.
The mixing method is not particularly limited, and any known method for mixing materials constituting a known powder composition may be used.

<<Method for producing conductive polymer powder (2)>>
A fifth aspect of the present invention is a method for producing a conductive powder, the method comprising: a step of adding a catalyst and an oxidizing agent to a reaction solution containing a monomer capable of forming a π-conjugated conductive polymer, a polyanion, graphene, and water, thereby oxidatively polymerizing the monomer to form a conductive polymer powder containing the π-conjugated conductive polymer and the polyanion (polymerization step); and a step of separating the conductive powder containing the conductive polymer powder and the graphene from the reaction solution (separation step).

The content ratio of the monomer to the polyanion in the reaction solution immediately before the start of polymerization is, on a mass basis, from (1:0.5) to (1:1), more preferably from (1:0.7) to (1:0.99), and even more preferably from (1:0.8) to (1:0.98).
When the content is equal to or more than the lower limit of the above range, the doping effect of the polyanion is sufficiently exhibited, and a conductive polymer powder having better conductivity can be obtained.
When the content is equal to or less than the upper limit of the above range, it is possible to obtain the doping effect of the polyanion, while forming a conductive polymer powder that has low dispersibility in water and can be easily precipitated.

The polymerization step of this embodiment can be carried out in the same manner as the polymerization step of the fourth embodiment, except that the reaction liquid contains graphene.
The amount of graphene contained in the reaction solution is not particularly limited, and, for example, when the total mass of the monomer, the polyanion, and the graphene is 100 mass%, the amount is preferably 10 mass% or more and 95 mass% or less, more preferably 60 mass% or more and 90 mass% or less, and still more preferably 70 mass% or more and 90 mass% or less.
When the content is within the above range, the graphene content in the conductive powder containing the conductive polymer powder and graphene formed after the polymerization reaction can be within the preferred range of the first aspect described above. In other words, the contents of the monomer and the polyanion contained in the reaction solution correspond to the contents of the conductive polymer powder contained in the conductive powder to be produced, and the graphene content contained in the reaction solution corresponds to the graphene content contained in the conductive powder to be produced.

A precipitation step similar to that of the fourth embodiment may be provided between the polymerization step and the separation step. In the precipitation step, an amine compound or an epoxy compound may be added to the reaction liquid after the polymerization reaction to modify the conductive polymer powder. The modified conductive polymer powder and the conductive powder containing graphene float (when an amine compound is added) or settle (when an epoxy compound is added) in the reaction liquid, making it easy to separate the conductive polymer powder and the graphene.
Since the specific gravity of the conductive polymer powder changes after the reaction as described above, it is believed that when the conductive polymer powder is reacted with an amine compound or an epoxy compound in the presence of graphene, the graphene also participates in the reaction, resulting in a ternary reaction product of graphene-conductive polymer powder-amine compound or epoxy compound. The ternary reaction product has excellent electrical conductivity, as shown in the examples described below. It is preferable that the graphene constituting the ternary reaction product has a functional group containing an atom other than carbon atom as described above, since the electrical conductivity is further improved.

The description of the graphene in this embodiment is the same as that of the graphene in the first embodiment, so duplicated description will be omitted.

(Production Example 1) Production of polystyrene sulfonic acid 206 g of sodium styrene sulfonate was dissolved in 1000 ml of ion-exchanged water, and while stirring at 80° C., 1.14 g of an oxidizing agent solution of ammonium persulfate previously dissolved in 10 ml of water was added dropwise over 20 minutes, and the solution was stirred for 12 hours.
1000ml of sulfuric acid diluted to 10% by mass was added to the obtained sodium polystyrene sulfonate-containing solution, and 1000ml of the solvent was removed from the obtained polystyrene sulfonic acid-containing solution by ultrafiltration. Next, 2000ml of ion-exchanged water was added to the remaining liquid, and about 2000ml of the solvent was removed by ultrafiltration to wash the polystyrene sulfonic acid with water. This water washing operation was repeated three times.
Water in the resulting solution was removed under reduced pressure to obtain colorless solid polystyrene sulfonic acid.

(Production Example 2) Synthesis of conductive polymer powder containing π-conjugated conductive polymer and polyanion 5.0 g of 3,4-ethylenedioxythiophene and a solution in which 5.0 g of polystyrenesulfonic acid was dissolved in 995.0 ml of ion-exchanged water were mixed at 20°C.
The resulting mixed solution was kept at 20° C., and while stirring, 11 g of ammonium persulfate dissolved in 89 ml of ion-exchanged water and an oxidation catalyst solution of 0.3 g of ferric sulfate dissolved in 49.7 ml of ion-exchanged water were slowly added, and the mixture was reacted with stirring for 24 hours.
The resulting reaction solution was filtered to obtain 10.0 g of conductive polymer powder containing polystyrenesulfonic acid-doped poly(3,4-ethylenedioxythiophene) (PEDOT-PSS).

Production Example 3 Synthesis of Conductive Polymer Powder Containing π-Conjugated Conductive Polymer and Polyanion 5.0 g of 3,4-ethylenedioxythiophene and a solution of 2.5 g of polystyrenesulfonic acid dissolved in 997.5 ml of ion-exchanged water were mixed at 20°C.
Except for using the mixed solution obtained here, the same procedure as in Production Example 2 was followed to obtain 7.5 g of conductive polymer powder containing PEDOT-PSS.

(Production Example 4) Synthesis of conductive powder containing π-conjugated conductive polymer, polyanion, and graphene 5.0 g of 3,4-ethylenedioxythiophene, 2.5 g of polystyrene sulfonic acid, and a solution in which 7.5 g of graphene (GNH-XZ, manufactured by Graphene Platform, Inc., unmodified) was dissolved in 997.5 ml of ion-exchanged water were mixed at 20°C.
The resulting mixed solution was kept at 20° C., and while stirring, 11 g of ammonium persulfate dissolved in 89 ml of ion-exchanged water and an oxidation catalyst solution of 0.3 g of ferric sulfate dissolved in 49.7 ml of ion-exchanged water were slowly added, and the mixture was reacted with stirring for 24 hours.
The resulting reaction liquid was filtered to obtain 15.0 g of a conductive polymer powder containing PEDOT-PSS and a conductive powder containing graphene.

(Production Example 5) Synthesis of conductive powder containing π-conjugated conductive polymer, polyanion, and graphene 5.0 g of 3,4-ethylenedioxythiophene, 2.5 g of polystyrene sulfonic acid, and a solution in which 7.5 g of graphene (GNH-XXX, manufactured by Graphene Platform, Inc., modified with carboxyl group/amino group) was dissolved in 997.5 ml of ion-exchanged water were mixed at 20°C.
Except for using the mixed solution obtained here, the same procedure as in Production Example 4 was followed to obtain 15.0 g of a conductive polymer powder containing PEDOT-PSS and a conductive powder containing graphene.

(Production Example 6) Synthesis of conductive powder containing π-conjugated conductive polymer, polyanion, graphene, and amine compound 5.0 g of 3,4-ethylenedioxythiophene, 2.5 g of polystyrene sulfonic acid, and a solution in which 7.5 g of graphene (GNH-XZ, manufactured by Graphene Platform, Inc., unmodified) was dissolved in 997.5 ml of ion-exchanged water were mixed at 20°C.
The resulting mixed solution was kept at 20° C., and while stirring, 11 g of ammonium persulfate dissolved in 89 ml of ion-exchanged water and an oxidation catalyst solution of 0.3 g of ferric sulfate dissolved in 49.7 ml of ion-exchanged water were slowly added, and the mixture was reacted with stirring for 24 hours.
Next, 500 g of isopropanol and 100 g of trioctylamine were added and stirred for 1 hour. It was confirmed that all of the precipitated reaction products of the π-conjugated conductive polymer, polyanion, graphene, and trioctylamine were suspended in the upper layer of the solution.
The resulting reaction liquid was filtered to obtain 15.2 g of a conductive powder containing a conductive polymer powder including PEDOT-PSS, and a reaction product of graphene and trioctylamine.

(Production Example 7) Synthesis of conductive powder containing π-conjugated conductive polymer, polyanion, graphene, and amine compound 5.0 g of 3,4-ethylenedioxythiophene, 2.5 g of polystyrene sulfonic acid, and a solution in which 7.5 g of graphene (GNH-XXX, manufactured by Graphene Platform, Inc., modified with carboxyl group/amino group) was dissolved in 997.5 ml of ion-exchanged water were mixed at 20°C.
Except for using the mixed solution obtained here, the same procedure as in Production Example 6 was followed to obtain 15.2 g of conductive powder containing a reaction product of conductive polymer powder containing PEDOT-PSS, graphene, and trioctylamine.

(Production Example 8) Synthesis of conductive powder containing π-conjugated conductive polymer, polyanion, graphene, and epoxy compound 5.0 g of 3,4-ethylenedioxythiophene, 2.5 g of polystyrene sulfonic acid, and a solution in which 7.5 g of graphene (GNH-XZ, manufactured by Graphene Platform, Inc., unmodified) was dissolved in 997.5 ml of ion-exchanged water were mixed at 20°C.
The resulting mixed solution was kept at 20° C., and while stirring, 11 g of ammonium persulfate dissolved in 89 ml of ion-exchanged water and an oxidation catalyst solution of 0.3 g of ferric sulfate dissolved in 49.7 ml of ion-exchanged water were slowly added, and the mixture was reacted with stirring for 24 hours.
Next, 100 g of butyl glycidyl ether was added and stirred for 1 hour. It was confirmed that all of the reactants of the precipitated π-conjugated conductive polymer, polyanion, graphene, and butyl glycidyl ether had settled in the lower layer of the solution.
The resulting reaction liquid was filtered to obtain 15.3 g of a conductive powder containing a conductive polymer powder including PEDOT-PSS and a reaction product of graphene and butyl glycidyl ether.

(Production Example 9) Synthesis of conductive powder containing π-conjugated conductive polymer, polyanion, graphene, and epoxy compound 5.0 g of 3,4-ethylenedioxythiophene, 2.5 g of polystyrene sulfonic acid, and a solution in which 7.5 g of graphene (GNH-XXX, manufactured by Graphene Platform, Inc., modified with carboxyl group/amino group) was dissolved in 997.5 ml of ion-exchanged water were mixed at 20°C.
Except for using the mixed solution obtained here, the same procedure as in Production Example 8 was followed to obtain 15.3 g of a conductive powder containing a reaction product of a conductive polymer powder containing PEDOT-PSS, graphene, and butyl glycidyl ether.

(Production Example 10) Synthesis of powder containing only π-conjugated conductive polymer 5.0 g of 3,4-ethylenedioxythiophene was dissolved in 1000 ml of ion-exchanged water to obtain a solution.
The resulting solution was kept at 20° C., and while stirring, 11 g of ammonium persulfate dissolved in 89 ml of ion-exchanged water and an oxidation catalyst solution of 0.3 g of ferric sulfate dissolved in 49.7 ml of ion-exchanged water were slowly added, and the mixture was reacted with stirring for 24 hours.
The resulting reaction solution was filtered to obtain 5.0 g of poly(3,4-ethylenedioxythiophene) powder.

Production Example 11 Synthesis of a conductive complex containing a π-conjugated conductive polymer and a polyanion 5.0 g of 3,4-ethylenedioxythiophene and a solution of 10.0 g of polystyrenesulfonic acid dissolved in 990.0 ml of ion-exchanged water were mixed at 20°C.
The resulting mixed solution was kept at 20° C., and while stirring, 11 g of ammonium persulfate dissolved in 89 ml of ion-exchanged water and an oxidation catalyst solution of 0.3 g of ferric sulfate dissolved in 49.7 ml of ion-exchanged water were slowly added, and the mixture was reacted with stirring for 24 hours.
The resulting reaction solution was filtered in an attempt to obtain a powder of PEDOT-PSS, but since all of the PEDOT-PSS passed through the filter paper, the separation of the powder was discontinued.

(Production Example 12)
1000 g of pentaerythritol and 40 g of Irgacure 184 (a photopolymerization initiator manufactured by BASF) were mixed to obtain an acrylic resin solution.

Example 1
0.2 g of the PEDOT-PSS powder of Production Example 2, 1.8 g of graphene powder (GNH-XZ, manufactured by Graphene Platform, Inc., unmodified) and 18.0 g of the acrylic resin solution of Production Example 12 were mixed to obtain a coating material.
The obtained coating material was applied onto a PET film using a #4 bar coater, and 400 mJ of ultraviolet light was irradiated to form a conductive layer on the PET film, thereby obtaining a conductive film. The surface resistance value of the conductive layer of the obtained conductive film was measured, and the results are shown in Table 1.

Conductive films were formed using the paints obtained in the following Examples and Comparative Examples in the same manner as in Example 1, and the surface resistance of the conductive layer was measured. The results are shown in Table 1. In Table 1, "1.0E+11" means "1.0×10 ¹¹ ," and the same applies to the other values.

Example 2
0.4 g of the PEDOT-PSS powder of Production Example 2, 1.6 g of graphene powder (GNH-XZ, manufactured by Graphene Platform, Inc., unmodified) and 18.0 g of the acrylic resin solution of Production Example 12 were mixed to obtain a coating material.

Example 3
0.6 g of the PEDOT-PSS powder of Production Example 2, 1.4 g of graphene powder (GNH-XZ, manufactured by Graphene Platform, Inc., unmodified) and 18.0 g of the acrylic resin solution of Production Example 12 were mixed to obtain a coating material.

Example 4
0.8 g of the PEDOT-PSS powder of Production Example 2, 1.2 g of graphene powder (GNH-XZ, manufactured by Graphene Platform, Inc., unmodified) and 18.0 g of the acrylic resin solution of Production Example 12 were mixed to obtain a coating material.

Example 5
1.0 g of the PEDOT-PSS powder of Production Example 2, 1.0 g of graphene powder (GNH-XZ, unmodified, manufactured by Graphene Platform Co., Ltd.), and 18.0 g of the acrylic resin solution of Production Example 12 were mixed to obtain a coating material.

Example 6
1.2 g of the PEDOT-PSS powder of Production Example 2, 0.8 g of graphene powder (GNH-XZ, manufactured by Graphene Platform, Inc., unmodified) and 18.0 g of the acrylic resin solution of Production Example 12 were mixed to obtain a coating material.

(Example 7)
1.4 g of the PEDOT-PSS powder of Production Example 2, 0.6 g of graphene powder (GNH-XZ, unmodified, manufactured by Graphene Platform Co., Ltd.), and 18.0 g of the acrylic resin solution of Production Example 12 were mixed to obtain a coating material.

(Example 8)
1.6 g of the PEDOT-PSS powder of Production Example 2, 0.4 g of graphene powder (GNH-XZ, unmodified, manufactured by Graphene Platform Co., Ltd.), and 18.0 g of the acrylic resin solution of Production Example 12 were mixed to obtain a coating material.

Example 9
1.8 g of the PEDOT-PSS powder of Production Example 2, 0.2 g of graphene powder (GNH-XZ, manufactured by Graphene Platform, Inc., unmodified) and 18.0 g of the acrylic resin solution of Production Example 12 were mixed to obtain a coating material.

Example 10
0.2 g of PEDOT-PSS powder of Production Example 2, 1.8 g of graphene powder (Graphene Platform, GNH-XXX, modified with carboxyl and amino groups), and 18.0 g of the acrylic resin solution of Production Example 12 were mixed to obtain a coating material.

Example 11
0.4 g of PEDOT-PSS powder of Production Example 2, 1.6 g of graphene powder (Graphene Platform, GNH-XXX, modified with carboxyl and amino groups) and 18.0 g of the acrylic resin solution of Production Example 12 were mixed to obtain a coating material.

Example 12
0.6 g of PEDOT-PSS powder of Production Example 2, 1.4 g of graphene powder (Graphene Platform, GNH-XXX, modified with carboxy and amino groups), and 18.0 g of the acrylic resin solution of Production Example 12 were mixed to obtain a coating material.

(Example 13)
0.8 g of PEDOT-PSS powder of Production Example 2, 1.2 g of graphene powder (Graphene Platform, GNH-XXX, modified with carboxy and amino groups), and 18.0 g of the acrylic resin solution of Production Example 12 were mixed to obtain a coating material.

(Example 14)
1.0 g of PEDOT-PSS powder of Production Example 2, 1.0 g of graphene powder (Graphene Platform, GNH-XXX, modified with carboxyl and amino groups), and 18.0 g of the acrylic resin solution of Production Example 12 were mixed to obtain a coating material.

(Example 15)
1.2 g of PEDOT-PSS powder of Production Example 2, 0.8 g of graphene powder (Graphene Platform, GNH-XXX, modified with carboxyl and amino groups), and 18.0 g of the acrylic resin solution of Production Example 12 were mixed to obtain a coating material.

(Example 16)
1.4 g of the PEDOT-PSS powder of Production Example 2, 0.6 g of graphene powder (Graphene Platform, GNH-XXX, modified with carboxy and amino groups), and 18.0 g of the acrylic resin solution of Production Example 12 were mixed to obtain a coating material.

(Example 17)
1.6 g of PEDOT-PSS powder of Production Example 2, 0.4 g of graphene powder (Graphene Platform, GNH-XXX, modified with carboxyl and amino groups), and 18.0 g of the acrylic resin solution of Production Example 12 were mixed to obtain a coating material.

(Example 18)
1.8 g of PEDOT-PSS powder of Production Example 2, 0.2 g of graphene powder (Graphene Platform, GNH-XXX, modified with carboxyl and amino groups), and 18.0 g of the acrylic resin solution of Production Example 12 were mixed to obtain a coating material.

(Example 19)
0.2 g of the PEDOT-PSS powder of Production Example 3, 1.8 g of graphene powder (GNH-XZ, unmodified, manufactured by Graphene Platform Co., Ltd.) and 18.0 g of the acrylic resin solution of Production Example 12 were mixed to obtain a coating material.

(Example 20)
0.4 g of the PEDOT-PSS powder of Production Example 3, 1.6 g of graphene powder (GNH-XZ, manufactured by Graphene Platform, Inc., unmodified) and 18.0 g of the acrylic resin solution of Production Example 12 were mixed to obtain a coating material.

(Example 21)
0.6 g of the PEDOT-PSS powder of Production Example 3, 1.4 g of graphene powder (GNH-XZ, manufactured by Graphene Platform, Inc., unmodified) and 18.0 g of the acrylic resin solution of Production Example 12 were mixed to obtain a coating material.

(Example 22)
0.8 g of the PEDOT-PSS powder of Production Example 3, 1.2 g of graphene powder (GNH-XZ, manufactured by Graphene Platform, Inc., unmodified) and 18.0 g of the acrylic resin solution of Production Example 12 were mixed to obtain a coating material.

(Example 23)
1.0 g of the PEDOT-PSS powder of Production Example 3, 1.0 g of graphene powder (GNH-XZ, unmodified, manufactured by Graphene Platform Co., Ltd.), and 18.0 g of the acrylic resin solution of Production Example 12 were mixed to obtain a coating material.

(Example 24)
1.2 g of the PEDOT-PSS powder of Production Example 3, 0.8 g of graphene powder (GNH-XZ, manufactured by Graphene Platform, Inc., unmodified) and 18.0 g of the acrylic resin solution of Production Example 12 were mixed to obtain a coating material.

(Example 25)
1.4 g of the PEDOT-PSS powder of Production Example 3, 0.6 g of graphene powder (GNH-XZ, manufactured by Graphene Platform, Inc., unmodified) and 18.0 g of the acrylic resin solution of Production Example 12 were mixed to obtain a coating material.

(Example 26)
1.6 g of the PEDOT-PSS powder of Production Example 3, 0.4 g of graphene powder (GNH-XZ, manufactured by Graphene Platform, Inc., unmodified) and 18.0 g of the acrylic resin solution of Production Example 12 were mixed to obtain a coating material.

(Example 27)
1.8 g of the PEDOT-PSS powder of Production Example 3, 0.2 g of graphene powder (GNH-XZ, unmodified, manufactured by Graphene Platform Co., Ltd.), and 18.0 g of the acrylic resin solution of Production Example 12 were mixed to obtain a coating material.

(Example 28)
0.2 g of PEDOT-PSS powder of Production Example 3, 1.8 g of graphene powder (Graphene Platform, GNH-XXX, modified with carboxyl and amino groups), and 18.0 g of the acrylic resin solution of Production Example 12 were mixed to obtain a coating material.

(Example 29)
0.4 g of the PEDOT-PSS powder of Production Example 3, 1.6 g of graphene powder (Graphene Platform, GNH-XXX, modified with carboxyl and amino groups) and 18.0 g of the acrylic resin solution of Production Example 12 were mixed to obtain a coating material.

(Example 30)
0.6 g of PEDOT-PSS powder of Production Example 3, 1.4 g of graphene powder (Graphene Platform, GNH-XXX, modified with carboxyl and amino groups) and 18.0 g of the acrylic resin solution of Production Example 12 were mixed to obtain a coating material.

(Example 31)
0.8 g of the PEDOT-PSS powder of Production Example 3, 1.2 g of graphene powder (Graphene Platform, GNH-XXX, modified with carboxyl and amino groups) and 18.0 g of the acrylic resin solution of Production Example 12 were mixed to obtain a coating material.

(Example 32)
1.0 g of PEDOT-PSS powder of Production Example 3, 1.0 g of graphene powder (Graphene Platform, GNH-XXX, modified with carboxyl and amino groups) and 18.0 g of the acrylic resin solution of Production Example 12 were mixed to obtain a coating material.

(Example 33)
1.2 g of the PEDOT-PSS powder of Production Example 3, 0.8 g of graphene powder (GNH-XXX, manufactured by Graphene Platform, modified with carboxyl and amino groups), and 18.0 g of the acrylic resin solution of Production Example 12 were mixed to obtain a coating material.

(Example 34)
1.4 g of the PEDOT-PSS powder of Production Example 3, 0.6 g of graphene powder (Graphene Platform, GNH-XXX, modified with carboxyl and amino groups), and 18.0 g of the acrylic resin solution of Production Example 12 were mixed to obtain a coating material.

(Example 35)
1.6 g of the PEDOT-PSS powder of Production Example 3, 0.4 g of graphene powder (Graphene Platform, GNH-XXX, modified with carboxyl and amino groups), and 18.0 g of the acrylic resin solution of Production Example 12 were mixed to obtain a coating material.

(Example 36)
1.8 g of the PEDOT-PSS powder of Production Example 3, 0.2 g of graphene powder (Graphene Platform, GNH-XXX, modified with carboxy and amino groups), and 18.0 g of the acrylic resin solution of Production Example 12 were mixed to obtain a coating material.

(Example 37)
2.0 g of the conductive powder of Production Example 4 and 18.0 g of the acrylic resin solution of Production Example 12 were mixed together to obtain a coating material.

(Example 38)
2.0 g of the conductive powder of Production Example 5 and 18.0 g of the acrylic resin solution of Production Example 12 were mixed together to obtain a coating material.

(Example 39)
2.0 g of the conductive powder of Production Example 6 and 18.0 g of the acrylic resin solution of Production Example 12 were mixed together to obtain a coating material.

(Example 40)
2.0 g of the conductive powder of Production Example 7 and 18.0 g of the acrylic resin solution of Production Example 12 were mixed to obtain a coating material.

(Example 41)
2.0 g of the conductive powder of Production Example 8 and 18.0 g of the acrylic resin solution of Production Example 12 were mixed together to obtain a coating material.

(Example 42)
2.0 g of the conductive powder of Production Example 9 and 18.0 g of the acrylic resin solution of Production Example 12 were mixed to obtain a coating material.

(Comparative Example 1)
2.0 g of the PEDOT-PSS powder of Production Example 2 and 18.0 g of the acrylic resin solution of Production Example 12 were mixed to obtain a coating material.

(Comparative Example 2)
2.0 g of the PEDOT-PSS powder of Production Example 3 and 18.0 g of the acrylic resin solution of Production Example 12 were mixed to obtain a coating material.

(Comparative Example 3)
2.0 g of graphene powder (GNH-XZ, unmodified, manufactured by Graphene Platform) and 18.0 g of the acrylic resin solution of Production Example 12 were mixed to obtain a coating material.

(Comparative Example 4)
2.0 g of graphene powder (manufactured by Graphene Platform, GNH-XXX, modified with carboxy and amino groups) and 18.0 g of the acrylic resin solution of Production Example 12 were mixed to obtain a coating material.

(Comparative Example 5)
1.0 g of the PEDOT powder of Production Example 10, 1.0 g of graphene powder (GNH-XZ, manufactured by Graphene Platform, Inc., unmodified) and 18.0 g of the acrylic resin solution of Production Example 12 were mixed to obtain a coating material.

(Comparative Example 6)
1.0 g of PEDOT powder of Production Example 10, 1.0 g of graphene powder (manufactured by Graphene Platform, Inc., GNH-XXX, modified with carboxyl group and amino group), and 18.0 g of the acrylic resin solution of Production Example 12 were mixed to obtain a coating material.

<Results>
It was found that the conductive layers of the Examples containing the conductive polymer powder and graphene exhibited excellent conductivity and were useful as electrodes. In addition, the conductive layers of the Examples in which the content ratio of the conductive polymer powder to the graphene was 6:4 to 1:9 by mass showed better conductivity than the other Examples. Furthermore, it was found that when the graphene was modified with a carboxy group and an amino group, the conductivity was better. On the other hand, when the conductive polymer powder was not included and graphene was used alone (Comparative Examples 3 to 6), the modification of graphene did not improve the conductivity. In other words, it was found that the modification of graphene improved the conductivity only when the conductive polymer powder according to the present invention was combined with graphene.

The conductive layers of Comparative Examples 1 and 2 did not contain graphene and therefore had poor conductivity.
The conductive layers of Comparative Examples 3 and 4 did not contain conductive polymer powder and therefore had poor conductivity.
The conductive layers of Comparative Examples 5 and 6 were inferior in conductivity since PEDOT was not doped with PSS.
It should be noted that Examples 1 to 36 are reference examples.

Claims (3)

The method includes the steps of: adding a catalyst and an oxidizing agent to a reaction solution containing a monomer capable of forming a π-conjugated conductive polymer, a polyanion, graphene, and water, thereby oxidatively polymerizing the monomer to form a conductive polymer powder containing the π-conjugated conductive polymer and the polyanion; and separating the conductive polymer powder and the conductive powder containing the graphene from the reaction solution,
A content ratio of the monomer to the polyanion in the reaction solution is, on a mass basis, from (1:0.5) to (1:1). a step of adding a catalyst and an oxidizing agent to a reaction solution containing a monomer capable of forming a π-conjugated conductive polymer, a polyanion, graphene, and water, thereby oxidatively polymerizing the monomer to form a conductive polymer powder containing the π-conjugated conductive polymer and the polyanion; a step of adding an amine compound to the reaction solution containing the conductive polymer powder and the graphene, and reacting the conductive polymer powder and the graphene to precipitate a conductive powder containing the modified conductive polymer powder and the graphene;
and separating the conductive powder from the reaction liquid.
A content ratio of the monomer to the polyanion in the reaction solution is, on a mass basis, from (1:0.5) to (1:1). a step of adding a catalyst and an oxidizing agent to a reaction solution containing a monomer capable of forming a π-conjugated conductive polymer, a polyanion, graphene, and water, thereby oxidatively polymerizing the monomer to form a conductive polymer powder containing the π-conjugated conductive polymer and the polyanion; a step of adding an epoxy compound to the reaction solution containing the conductive polymer powder and the graphene, and reacting the epoxy compound to precipitate a conductive powder containing the modified conductive polymer powder and the graphene;
and separating the conductive powder from the reaction liquid.
A content ratio of the monomer to the polyanion in the reaction solution is, on a mass basis, from (1:0.5) to (1:1).