Method for producing a conductive polymer-containing liquid and method for producing a conductive laminate

Abstract

To provide a conductive polymer-containing solution which can be stably stored even in storage environments approximately at 40°C and a method for producing the same and to provide a conductive laminate and a method for producing the same.SOLUTION: There is provided a conductive polymer-containing solution which contains a conductive composite body containing a π-conjugated conductive polymer and a polyanion, the polyanion which does not form the conductive composite body, a molecular weight maintaining agent for suppressing the reduction of the molecular weight of the polyanion which does not form the conductive composite body and a dispersion medium, wherein when the initial weight average molecular weight of the polyanion which does not form the conductive composite body is defined as X and the weight average molecular weight of the polyanion which does not form the conductive composite body after the conductive polymer-containing solution is allowed to stand at 40°C for 720 hours is defined as Y, the molecular weight ratio represented by Y / X is 0.88 or more.SELECTED DRAWING: None

Description

Technical Field

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

Background Art

[0002] A π-conjugated conductive polymer whose main chain is composed of a π-conjugated system forms a conductive complex by doping with a polyanion having an anion group, and exhibits dispersibility in water. By coating a film substrate or the like with a conductive polymer-containing liquid containing the conductive complex (sometimes referred to as a conductive polymer dispersion), a conductive film provided with a conductive layer can be produced. Further, in order to enhance the wettability of the conductive polymer-containing liquid with respect to the film substrate or to enhance the conductivity of the formed conductive layer, an epoxy compound may be reacted with the conductive complex. For example, Patent Document 1 discloses a method for improving the conductivity of a conductive complex by reacting a cyclic epoxy compound.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Incidentally, when a storage period of about 30 days (720 hours) elapses after the production of the conductive polymer-containing liquid, the characteristics of the conductive layer formed from the coating film of the conductive polymer-containing liquid may change. Examples of this change include a decrease in weather resistance. When the inventor examined the cause of this change, it was considered that the temperature during storage was affecting because the change was likely to occur in the lots manufactured in summer. As a result of confirmation, it was found that there was almost no change even when stored at room temperature of about 25°C for 720 hours, but there was a change when stored at room temperature reaching about 40°C for 720 hours. Next, when analyzing the components contained in the conductive polymer-containing liquid before and after the change occurred, it was found that the weight average molecular weight of the single polyanion that did not form the conductive complex decreased (became lower molecular weight). Furthermore, by adding a drug (molecular weight maintaining agent) that suppresses the decrease in the molecular weight to the conductive polymer-containing liquid, it was found that even after storage at 40°C for 720 hours, the molecular weight of the single polyanion did not decrease, and the characteristics of the formed conductive layer hardly changed.

[0005] Through the above examinations, the present invention provides a conductive polymer-containing liquid capable of being stably stored even in a storage environment of about 40°C, a method for producing the same, a conductive laminate, and a method for producing the same.

Means for Solving the Problems

[0006] [1] A conductive polymer-containing liquid containing a conductive complex containing a π-conjugated conductive polymer and a polyanion, the polyanion that does not form the conductive complex, a molecular weight maintaining agent that suppresses the decrease in molecular weight of the polyanion that does not form the conductive complex, and a dispersion medium, where the initial weight average molecular weight of the polyanion that does not form the conductive complex is X, and when the weight average molecular weight of the polyanion that does not form the conductive complex after the conductive polymer-containing liquid is allowed to stand at 40°C for 720 hours is Y, the molecular weight ratio represented by Y / X is 0.88 or more. [2] The conductive polymer-containing liquid according to [1], wherein the molecular weight maintaining agent contains an aromatic compound having two or more hydroxyl groups. [3] The conductive polymer-containing liquid according to [1] or [2], wherein the π-conjugated conductive polymer is poly(3,4-ethylenedioxythiophene). [4] The conductive polymer-containing liquid according to any one of [1] to [3], wherein the polyanion is polystyrene sulfonic acid. [5] A method for producing a conductive polymer-containing liquid, comprising: adding an epoxy compound to the conductive polymer-containing liquid according to any one of [1] to [4] to precipitate a reaction product containing the conductive composite; and recovering the precipitated reaction product and adding an organic solvent. [6] A method for producing a conductive polymer-containing liquid, comprising: adding an amine compound or a quaternary ammonium compound to the conductive polymer-containing liquid according to any one of [1] to [4] to precipitate a reaction product containing the conductive composite; and recovering the precipitated reaction product and adding an organic solvent. [7] A method for producing a conductive polymer-containing liquid, comprising: adding an epoxy compound and an amine compound or a quaternary ammonium compound to the conductive polymer-containing liquid according to any one of [1] to [4] to precipitate a reaction product containing the conductive composite; and recovering the precipitated reaction product and adding an organic solvent. [8] A conductive laminate comprising a substrate and a conductive layer formed of a cured layer of the conductive polymer-containing liquid according to any one of [1] to [4] on at least a part of the surface of the substrate. [9] A method for producing a conductive laminate, comprising: obtaining a conductive polymer-containing liquid by the production method according to any one of [5] to [7]; and coating the conductive polymer-containing liquid on at least a part of the surface of a substrate.

[10] The method for producing a conductive laminate according to [9], wherein the substrate is a film substrate. [Effect of the Invention]

[0007] The conductive polymer-containing liquid of the present invention can be stably stored even in a storage environment of about 40°C. According to the method for producing a conductive polymer-containing liquid of the present invention, a paint containing a conductive composite dispersed in an organic solvent can be easily produced. In the conductive laminate of the present invention, sufficient atmospheric exposure resistance of the conductive layer can be obtained. According to the method for manufacturing the conductive laminate of the present invention, a conductive laminate having a conductive layer with sufficient atmospheric exposure resistance can be easily manufactured.

[0008] The present invention is considered to contribute to SDGs Goal 12, "Responsibility to Produce and Responsibility to Consume".

[0009] In this specification and the claims, the lower limit value and the upper limit value of the numerical range indicated by "~" are included in the numerical range.

Embodiments for Carrying Out the Invention

[0010] ≪Conductive Polymer-Containing Liquid≫ The first aspect of the present invention is a conductive polymer-containing liquid containing a conductive composite containing a π-conjugated conductive polymer and a polyanion, the polyanion not forming the conductive composite (hereinafter sometimes referred to as "single polyanion"), a molecular weight maintaining agent that suppresses the low molecular weight of the single polyanion, and a dispersion medium.

[0011] In the conductive polymer-containing liquid of this aspect, the conductive composite may be in a dispersed state or a dissolved state. In this specification, unless otherwise specified, the dispersed state and the dissolved state are not distinguished.

[0012] <π-Conjugated Conductive Polymer> The π-conjugated conductive polymer is not particularly limited as long as it has the effects of the present invention as long as it is an organic polymer whose main chain is composed of a π-conjugated system. For example, polypyrrole-based conductive polymers, polythiophene-based conductive polymers, polyacetylene-based conductive polymers, polyphenylene-based conductive polymers, polyphenylene vinylene-based conductive polymers, polyaniline-based conductive polymers, polyacene-based conductive polymers, polythiophene vinylene-based conductive polymers, and copolymers thereof can be mentioned. From the viewpoint of stability in air, polypyrrole-based conductive polymers, polythiophenes, and polyaniline-based conductive polymers are preferable, and from the viewpoint of transparency, polythiophene-based conductive polymers are more preferable.

[0013] 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), poly(3-iodothiophene), 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), 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-didodecyloxythiophene), 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), 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 the above π-conjugated conductive polymers, poly(3,4-ethylenedioxythiophene) is particularly preferred in terms of conductivity, transparency, and heat resistance. The π-conjugated conductive polymer contained in the conductive composite may be one type or two or more types.

[0014] <Polyanion> A polyanion is a polymer having two or more monomer units with anionic groups in the molecule. The anionic group of this polyanion functions as a dopant for the π-conjugated conductive polymer and can improve the conductivity of the π-conjugated conductive polymer. The anionic group of the polyanion is preferably a sulfo group or a carboxy group. Specific examples of such polyanions include polystyrene sulfonic acid, polyvinyl sulfonic acid, polyallyl sulfonic acid, polyacrylate esters having a sulfo group, polymethacrylate esters having a sulfo group (for example, poly(4-sulfobutyl methacrylate), polysulfoethyl methacrylate, polymethacryloyloxybenzene sulfonic acid), poly(2-acrylamido-2-methylpropane sulfonic acid), polymers having a sulfo group such as polyisoprene sulfonic acid, and polymers having a carboxy group such as polyvinyl carboxylic acid, polystyrene carboxylic acid, polyallyl carboxylic acid, polyacrylic acid, polymethacrylic acid, poly(2-acrylamido-2-methylpropane carboxylic acid), polyisoprene carboxylic acid. These may be homopolymers or copolymers of two or more types. Among these polyanions, polymers having a sulfo group are preferred and polystyrene sulfonic acid is more preferred because they can achieve higher conductivity. The polyanion may be of one type or two or more types.

[0015] A conductive composite is formed by doping a polyanion into a π-conjugated conductive polymer. However, in the polyanion that forms the conductive composite, some anion groups are not doped into the π-conjugated conductive polymer and have surplus anion groups that do not participate in the doping. Since this surplus anion group is a hydrophilic group, the conductive composite has high water dispersibility and low organic solvent dispersibility. When the number of all anion groups of the polyanion that forms the conductive composite is set to 100 mol%, the surplus anion groups are preferably 30 mol% or more and 90 mol% or less, and more preferably 45 mol% or more and 75 mol% or less.

[0016] The content ratio of the polyanion in the conductive composite is preferably in the range of 1 part by mass or more and 1000 parts by mass or less, more preferably 10 parts by mass or more and 700 parts by mass or less, and even more preferably 100 parts by mass or more and 500 parts by mass or less with respect to 100 parts by mass of the π-conjugated conductive polymer. If the content ratio of the polyanion is equal to or higher than the lower limit value, the doping effect on the π-conjugated conductive polymer tends to be enhanced, and the conductivity becomes higher. On the other hand, if the content of the polyanion is equal to or lower than the upper limit value, the π-conjugated conductive polymer can be sufficiently contained, so that sufficient conductivity can be ensured.

[0017] When the conductive polymer-containing liquid of this embodiment is subjected to a filtration treatment, the polyanion forming the conductive composite and the polyanion not forming the conductive composite (single polyanion) can be separated. That is, while the conductive composite is trapped by the filter, the single polyanion can be permeated and recovered in the filtrate. For the filtration treatment, it is preferable to use a membrane filter having an average pore diameter of 0.2 μm.

[0018] The weight average molecular weight of the single polyanion is the average molecular weight on a mass basis (which may also be referred to as the weight average molecular weight) determined by gel permeation chromatography using pullulan with a known weight average molecular weight as a standard substance.

[0019] In the conductive polymer-containing liquid of this embodiment, regarding the weight average molecular weight of the single polyanion, when the initial weight average molecular weight before standing at 40 °C for 720 hours is X and the weight average molecular weight after standing at 40 °C for 720 hours is Y, the molecular weight ratio represented by Y / X is 0.88 or more. The closer this molecular weight ratio is to 1.0, the higher the storage stability during the above standing period. Also, even after passing through a storage period of 720 hours at 40 °C, a conductive layer excellent in atmospheric exposure resistance can be formed.

[0020] In the present specification and claims, the significant figures of the molecular weight ratio (Y / X) shall be two digits. For example, for the calculated value 0.89583··· of Y / X = 86,000 / 96,000, it is rounded to 0.90 by rounding off the third decimal place. Here, the significant figures of each weight-average molecular weight may be two digits.

[0021] The weight-average molecular weight X of the single polyanion is preferably 80,000 or more and 800,000 or less, more preferably 90,000 or more and 700,000 or less, still more preferably 95,000 or more and 600,000 or less, particularly preferably 95,000 or more and 500,000 or less, and most preferably 95,000 or more and 400,000 or less. When it is at or above the lower limit value of the above range, while suppressing the gelation of the conductive polymer-containing liquid, the conductivity of the conductive layer formed from the conductive polymer-containing liquid can be increased. Further, a conductive polymer-containing liquid having the target Y / X ratio can be easily obtained. When it is at or below the upper limit value of the above range, the dispersibility of the polyanion in the conductive polymer-containing liquid is increased, and the conductivity of the conductive layer can be further increased.

[0022] The content of the single polyanion with respect to the total mass of the conductive polymer-containing liquid of this embodiment can be, for example, 0.01% by mass or more and 2.5% by mass or less, preferably 0.05% by mass or more and 2.0% by mass or less, more preferably 0.1% by mass or more and 1.5% by mass or less, and still more preferably 0.5% by mass or more and 1.0% by mass or less. When it is at or above the lower limit value of the above range, the atmospheric exposure resistance of the formed conductive layer becomes higher. When it is at or below the upper limit value of the above range, the conductivity of the formed conductive layer becomes higher.

[0023] The content of the single polyanion in the conductive polymer-containing liquid of this embodiment can be, for example, 1 part by mass or more and 10,000 parts by mass or less, preferably 5 parts by mass or more and 5,000 parts by mass or less, more preferably 10 parts by mass or more and 1,000 parts by mass or less, and still more preferably 50 parts by mass or more and 500 parts by mass or less with respect to 100 parts by mass of the π-conjugated conductive polymer. When it is at or above the lower limit value of the above range, the atmospheric exposure resistance of the formed conductive layer becomes higher. When it is below the upper limit value of the above range, the conductivity of the formed conductive layer becomes higher.

[0024] The content of the conductive composite with respect to the total mass of the conductive polymer-containing liquid of this embodiment can be, for example, 0.01% by mass or more and 10.0% by mass or less, preferably 0.05% by mass or more and 7.5% by mass or less, more preferably 0.1% by mass or more and 5.0% by mass or less, and even more preferably 0.5% by mass or more and 2.5% by mass or less. When it is above the lower limit value of the above range, the conductivity of the formed conductive layer becomes higher. When it is below the upper limit value of the above range, the dispersibility of the conductive composite in the conductive polymer-containing liquid can be enhanced, and a uniform conductive layer can be formed.

[0025] The content of the π-conjugated conductive polymer with respect to the total mass of the conductive polymer-containing liquid of this embodiment can be, for example, 0.1% by mass or more and 2.0% by mass or less. The total content of the polyanion with respect to the total mass of the conductive polymer-containing liquid of this embodiment can be, for example, 0.3% by mass or more and 10% by mass or less. Here, the polyanion is not distinguished whether it forms a conductive composite or not. The content ratio of the π-conjugated conductive polymer and the polyanion contained in the conductive polymer-containing liquid of this embodiment is preferably (1:2) to (1:5) on a mass basis, more preferably (1:2) to (1:4), and even more preferably (1:2) to (1:3). Here, the polyanion is not distinguished whether it forms a conductive composite or not.

[0026] <Molecular weight maintainer> The conductive polymer-containing liquid of this embodiment contains a molecular weight maintainer that suppresses the low molecular weight of a single polyanion. The molecular weight maintainer is a chemical agent that can make the molecular weight ratio Y / X of the weight average molecular weight of a single polyanion be 0.88 or more before and after the conductive polymer-containing liquid of this embodiment is allowed to stand at 40 °C for 720 hours.

[0027] The molecular weight maintaining agent preferably contains an aromatic compound having two or more hydroxyl groups. Hereinafter, the aromatic compound may be referred to as "aromatic compound (A)". Although the detailed mechanism is unclear, including the aromatic compound (A) makes it easy to make the molecular weight ratio represented by Y / X 0.88 or more. The aromatic compound (A) may have one or more carboxy groups, and the carboxy groups may be esterified. Here, it is assumed that a non-esterified carboxy group has one hydroxyl group and an esterified carboxy group has no hydroxyl group. The aromatic compound (A) is one or more selected from the group consisting of a compound in which two or more hydrogen atoms of an aromatic ring are substituted with hydroxyl groups, a compound in which two or more hydrogen atoms of an aromatic ring are substituted with carboxy groups, and a compound in which one or more hydrogen atoms of an aromatic ring are substituted with hydroxyl groups and one or more hydrogen atoms are substituted with carboxy groups.

[0028] Examples of the aromatic ring include a benzene ring, a naphthalene ring, an anthracene ring, furan, thiophene, pyrrole, etc., and a benzene ring is preferred. Examples of the compound in which two or more hydrogen atoms of the aromatic ring are substituted with hydroxyl groups include resorcinol (1,3-dihydroxybenzene), catechol (1,2-hydroxybenzene), hydroquinone (1,4-hydroxybenzene), pyrogallol (1,2,3-trihydroxybenzene), etc. Examples of the compound in which two or more hydrogen atoms of the aromatic ring are substituted with carboxy groups include phthalic acid, isophthalic acid, terephthalic acid, etc. Examples of the compound in which one or more hydrogen atoms of the aromatic ring are substituted with a hydroxy group and one or more hydrogen atoms are substituted with a carboxy group include gallic acid, 4-hydroxybenzoic acid, 4-carboxypyrogallol, etc. Examples of the ester of gallic acid include methyl gallate, propyl gallate, butyl gallate, etc. Among the aromatic compounds (A), at least one of gallic acid and an ester of gallic acid is preferred. The aromatic compound (A) contained in the conductive polymer-containing liquid of this aspect may be one kind or two or more kinds.

[0029] The content of the aromatic compound (A) with respect to the total mass of the conductive polymer-containing liquid of this aspect can be, for example, 0.01% by mass or more and 10% by mass or less, preferably 0.05% by mass or more and 4.0% by mass or less, more preferably 0.1% by mass or more and 3.0% by mass or less, and even more preferably 0.3% by mass or more and 2.0% by mass or less. When it is at or above the lower limit value of the above range, a conductive polymer-containing liquid in which the molecular weight ratio Y / X of a single polyanion shows a predetermined value or more can be easily obtained. In addition, the conductivity of the formed conductive layer can be further improved. The upper limit value of the above range is a guideline.

[0030] The content ratio of the aromatic compound (A) contained in the conductive polymer-containing liquid of this aspect can be, for example, 0.1 part by mass or more and 1000 parts by mass or less with respect to 100 parts by mass of a single polyanion, preferably 0.5 part by mass or more and 500 parts by mass or less, more preferably 1 part by mass or more and 100 parts by mass or less, and even more preferably 5 parts by mass or more and 50 parts by mass or less. When it is within the above range, a conductive polymer-containing liquid in which the molecular weight ratio Y / X of a single polyanion shows a predetermined value or more can be easily obtained.

[0031] The content ratio of the aromatic compound (A) contained in the conductive polymer-containing liquid of this aspect can be, for example, 1.0 part by mass or more and 1000 parts by mass or less with respect to 100 parts by mass of the total of the polyanion forming the conductive complex and a single polyanion, preferably 5.0 part by mass or more and 500 parts by mass or less, more preferably 10 parts by mass or more and 300 parts by mass or less, and even more preferably 20 parts by mass or more and 200 parts by mass or less. When it is within the above range, a conductive polymer-containing liquid in which the molecular weight ratio Y / X of a single polyanion shows a predetermined value or more can be easily obtained.

[0032] [Dispersion medium] Examples of the dispersion medium contained in the conductive polymer-containing liquid of this aspect include water, organic solvents, and a mixed liquid of water and organic solvents. The molecular weight maintainer shall not apply to the dispersion medium.

[0033] Examples of the organic solvent include alcohol solvents, ether solvents, ketone solvents, ester solvents, aromatic hydrocarbon solvents, etc. Specific examples will be described later. The organic solvent may be used alone or in combination of two or more.

[0034] Since the conductive composite has high dispersibility in water, the dispersion medium of the conductive polymer-containing liquid of this aspect is preferably an aqueous dispersion medium containing water. The content ratio of water to the total dispersion medium contained in the conductive polymer-containing liquid of this aspect can be, for example, 50% by mass or more and 100% by mass or less, preferably 60% by mass or more and 100% by mass or less, and more preferably 70% by mass or more and 100% by mass or less. As the dispersion medium other than water, monohydric alcohol is preferred.

[0035] <Optional component> The conductive polymer-containing liquid of this aspect may further contain a binder component and other additives.

[0036] (Other additives) The additives are not particularly limited as long as the effects of the present invention can be obtained. For example, surfactants, inorganic conductive agents, defoamers, coupling agents, antioxidants, ultraviolet absorbers, etc. can be used. Examples of the surfactant include nonionic, anionic, and cationic surfactants. From the viewpoint of storage stability, nonionic surfactants are preferred. Also, polymer surfactants such as polyvinylpyrrolidone may be added. Examples of the inorganic conductive agent include metal ions and conductive carbon. The metal ions can be generated by dissolving a metal salt in water. Examples of the defoamer include silicone resins, polydimethylsiloxane, silicone oils, etc. Examples of the coupling agent include silane coupling agents having a vinyl group or an amino group. Examples of the antioxidant include phenolic antioxidants, amine antioxidants, phosphorus antioxidants, sulfur antioxidants, saccharides, and the like. 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, benzoate-based ultraviolet absorbers, and the like. When the conductive polymer-containing liquid of this embodiment contains the above additives, the content ratio can be appropriately determined according to the type of the additive. For example, it can be in the range of 0.001 parts by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the π-conjugated conductive polymer and the total polyanion.

[0037] ≪Manufacturing method (1) of conductive polymer-containing liquid≫ The conductive polymer-containing liquid of the first embodiment can be produced by a production method including, for example, the polymerization step described below. The polymerization step is a step of obtaining a conductive polymer-containing liquid containing the π-conjugated conductive polymer, the aqueous dispersion medium, the polyanion (single polyanion) that has not formed the conductive complex, and a conductive complex containing the π-conjugated conductive polymer and the polyanion by polymerizing a monomer that forms the π-conjugated conductive polymer in a reaction liquid containing the polyanion and the aqueous dispersion medium. By adding a molecular weight maintaining agent to the conductive polymer-containing liquid obtained in the polymerization step, the conductive polymer-containing liquid of the first embodiment is obtained.

[0038] The weight average molecular weight (Mw) of the polyanion used in the polymerization step is preferably 80,000 or more and 1,000,000 or less, more preferably 100,000 or more and 800,000 or less, and even more preferably 150,000 or more and 600,000 or less. Here, the weight average molecular weight is the average molecular weight on a mass basis measured by gel permeation chromatography (GPC) using pullulan of a known weight average molecular weight as a standard substance. When the weight average molecular weight is within the above-mentioned preferred range, the conductivity of the conductive layer is further enhanced. Before subjecting the aqueous solution of the polyanion to GPC, it is preferable to filter it through a membrane filter with an average pore size of 0.2 μm in order to remove impurities and the like contained in the aqueous solution, and use the filtrate for GPC measurement.

[0039] As a method for synthesizing a polyanion having a specific weight average molecular weight, for example, a method of adjusting the addition amount of an oxidizing agent for polymerizing the monomers constituting the polyanion can be mentioned. Specifically, increasing the concentration of the oxidizing agent can reduce the weight average molecular weight of the polyanion formed by the polymerization of the monomers. By this method, for example, polystyrene sulfonic acid having a weight average molecular weight Mw of 100,000 or more and 1,000,000 or less can be obtained.

[0040] [Polymerization step] A reaction solution containing the monomer for forming the π-conjugated conductive polymer and the polyanion in an arbitrary content ratio is prepared, and the monomer is polymerized to form a π-conjugated conductive polymer. In the reaction solution, the polyanion naturally dopes the π-conjugated conductive polymer, and a conductive composite composed of the π-conjugated conductive polymer and the polyanion is formed. Also, a part of the polyanion does not form a conductive composite and remains as a single polyanion.

[0041] A catalyst may be added to the reaction solution. The catalyst is not particularly limited as long as it can promote the polymerization of the monomer, and examples thereof include transition metal compounds such as ferric chloride, ferrous sulfate, ferric nitrate, and cupric chloride. Among them, since the polymerization of the monomer proceeds stably at room temperature, it is preferable to use a catalyst containing iron.

[0042] It is preferable to contain an oxidizing agent in the reaction solution together with the catalyst. The oxidizing agent can polymerize the monomer. Examples of the oxidizing agent include persulfates such as ammonium persulfate, sodium persulfate, and potassium persulfate. It is preferable that the oxidizing agent is added slowly to the mixed solution S1 containing the monomer, the polyanion, and the catalyst as an oxidizing agent solution previously dissolved in ion-exchanged water to initiate polymerization. The concentration of the oxidizing agent solution is preferably 1.0% by mass or more and 3.0% by mass or less. When the volume of the mixed solution S1 before adding the oxidizing agent solution is V1 and the volume of the oxidizing agent solution is V2, the volume ratio represented by V1 / V2 is preferably 1.0 to 2.0, more preferably 1.2 to 1.5. When adding all of the oxidizing agent solution to the mixed solution S1, the time required from the start of addition to the end of addition is preferably 1 to 8 hours, more preferably 2 to 7 hours, and even more preferably 3 to 6 hours. The temperature of each of the mixed solution S1 before adding the oxidizing agent solution and the oxidizing agent solution is preferably 5 to 30°C independently.

[0043] It is preferable to maintain the temperature of the reaction solution obtained after adding all of the oxidizing agent solution at 5 to 30°C and perform the polymerization reaction. The standard of the reaction time required until the completion of the reaction in the reaction solution is 4 to 12 hours, and it is preferable that the reaction is completed in 6 to 10 hours. The completion of the polymerization reaction can be known by confirming that the monomer forming the π-conjugated conductive polymer has disappeared by gas chromatography.

[0044] The content ratio of the monomer: the polyanion contained in the mixed solution S1 is preferably (1:2) to (1:5) on a mass basis, more preferably (1:2) to (1:4), and even more preferably (1:2) to (1:3). When it is above the lower limit value of the above range, the doping effect by the polyanion is sufficiently exerted, and the dispersion stability of the conductive composite is further improved. When it is below the upper limit value of the above range, a conductive polymer-containing liquid capable of forming a conductive layer excellent in conductivity can be easily obtained. In addition, a conductive polymer-containing liquid having the target Y / X ratio can be easily obtained.

[0045] The content of the monomer with respect to the total mass of the mixed solution S1 is preferably, for example, 0.1% by mass or more and 10% by mass or less, more preferably 0.2% by mass or more and 5.0% by mass or less, and still more preferably 0.3% by mass or more and 1.0% by mass or less. When it is within the above range, the polymerization reaction can proceed stably, so the complexation with the polyanion present in the reaction system easily proceeds. Further, a conductive polymer-containing solution having the target Y / X ratio can be easily obtained.

[0046] The content of the polyanion with respect to the total mass of the mixed solution S1 is preferably set based on the content ratio with respect to the monomer. For example, 0.1% by mass or more and 10% by mass or less is preferable, 0.3% by mass or more and 8.0% by mass or less is more preferable, and 0.6% by mass or more and 4.0% by mass or less is still more preferable. When it is within the above range, a conductive polymer-containing solution having the target Y / X ratio can be easily obtained.

[0047] The weight average molecular weight of the polyanion to be contained in the mixed solution S1 is preferably within the above range. When it is within the above range, a conductive polymer-containing solution having the target Y / X ratio can be easily obtained.

[0048] The content of the catalyst with respect to the total mass of the reaction solution after all the oxidizing agent has been added is preferably, for example, 0.001% by mass or more and 2.0% by mass or less, more preferably 0.01% by mass or more and 1.0% by mass or less, and still more preferably 0.1% by mass or more and 0.5% by mass or less, with respect to the total mass of the reaction solution. When it is within the above range, the polymerization reaction can proceed stably, so the complexation with the polyanion easily proceeds. Further, a conductive polymer-containing solution having the target Y / X ratio can be easily obtained.

[0049] The addition amount of the oxidizing agent with respect to the total mass of the reaction solution after all the oxidizing agent has been added is preferably, for example, 0.01% by mass or more and 2.0% by mass or less, more preferably 0.1% by mass or more and 1.5% by mass or less, still more preferably 0.5% by mass or more and 1.2% by mass or less, and particularly preferably 0.7% by mass or more and 1.0% by mass or less. When it is within the above range, the polymerization reaction can proceed stably, so the complexation with the polyanion proceeds easily. Further, a conductive polymer-containing liquid having the target Y / X ratio can be easily obtained.

[0050] The amount of the monomer charged before the reaction with respect to the total mass of the reaction solution after all the oxidizing agent has been added is preferably, for example, 0.05% by mass or more and 5.0% by mass or less, more preferably 0.1% by mass or more and 3.0% by mass or less, and even more preferably 0.2% by mass or more and 2.0% by mass or less. When it is within the above range, the polymerization reaction can proceed stably, so the complexation with the polyanion present in the reaction system proceeds easily. Further, a conductive polymer-containing liquid having the target Y / X ratio can be easily obtained.

[0051] The amount of the polyanion charged before the reaction with respect to the total mass of the reaction solution after all the oxidizing agent has been added is preferably, for example, 0.1% by mass or more and 10% by mass or less, more preferably 0.3% by mass or more and 6.0% by mass or less, and even more preferably 0.5% by mass or more and 4.0% by mass or less. When it is within the above range, a conductive polymer-containing liquid having the target Y / X ratio can be easily obtained.

[0052] The aqueous dispersion medium constituting the reaction solution contains at least water and may further contain a water-soluble organic solvent. Specific examples of the water-soluble organic solvent will be described later. The content ratio of water with respect to the total mass of the aqueous dispersion medium is preferably, for example, 60% by mass or more and 100% by mass or less, more preferably 70% by mass or more and 100% by mass or less, even more preferably 80% by mass or more and 100% by mass or less, and particularly preferably 90% by mass or more and 100% by mass or less.

[0053] (Removal of catalyst and oxidizing agent) When using the reaction solution to which the catalyst and the oxidizing agent are added, it is preferable to remove the catalyst and the oxidizing agent from the conductive polymer-containing liquid obtained after the reaction. As a method for removal, for example, there are a method of bringing a conductive polymer-containing liquid into contact with an ion exchange resin to adsorb a catalyst and an oxidizing agent onto the ion exchange resin, a method of removing the conductive polymer-containing liquid by ultrafiltration to replace and remove an aqueous dispersion medium, and the like. Among these, the method using an ion exchange resin is preferable because it is simple. It is preferable to use a cation exchange resin and an anion exchange resin in combination as the ion exchange resin.

[0054] (Dispersion treatment) It is preferable to stir the conductive polymer-containing liquid obtained in the polymerization step to perform a dispersion treatment of the conductive composite. The method of stirring is not particularly limited, and it may be stirring with a weak shearing force such as a stirrer, or stirring may be performed using a disperser with a high shearing force such as a high-pressure homogenizer. However, from the viewpoint of enhancing dispersibility, it is preferable to use a high-pressure homogenizer or the like.

[0055] Through the above polymerization step, a conductive polymer-containing liquid containing a conductive composite including a π-conjugated conductive polymer and a polyanion, the aqueous dispersion medium, and the polyanion (single polyanion) that does not form the conductive composite is obtained.

[0056] After separating the single polyanion from the obtained conductive polymer-containing liquid and measuring its weight average molecular weight X, it is preferable because it can be accurately measured without being affected by the conductive composite. As the method of separation, for example, there is a method of filtering the conductive polymer-containing liquid using a membrane filter with an average pore diameter of 0.2 μm to trap the conductive composite on the filter while allowing the single polyanion to permeate and recovering it in the filtrate.

[0057] The weight average molecular weight X of the single polyanion is measured by gel permeation chromatography and is the average molecular weight on a mass basis determined using pullulan with a known weight average molecular weight as a standard substance.

[0058] The weight average molecular weight X of the individual polyanion is preferably smaller than the weight average molecular weight Z of the polyanion subjected to the polymerization step. The ratio of the weight average molecular weight X to the weight average molecular weight Z, represented by X / Z, can be, for example, 0.1 or more and less than 0.67.

[0059] The method of adding the molecular weight maintaining agent to the conductive polymer-containing liquid obtained in the polymerization step is not particularly limited. After adding it by a conventional method, the conductive polymer-containing liquid may be stirred to dissolve it uniformly. The conductive polymer-containing liquid after adding the molecular weight maintaining agent may be subjected to the precipitation and recovery steps described below.

[0060] ≪Method for producing conductive polymer-containing liquid (2)≫ The second aspect of the present invention is to add one or more selected from an epoxy compound, an amine compound, and a quaternary ammonium compound to the conductive polymer-containing liquid of the first aspect to precipitate a reaction product containing the conductive composite (precipitation step), and a method for producing a conductive polymer-containing liquid, comprising recovering the precipitated reaction product and adding an organic solvent (recovery step).

[0061] [Precipitation step] The conductive polymer-containing liquid of the first aspect (hereinafter sometimes referred to as a conductive polymer dispersion) is obtained, for example, by a production method including the above polymerization step. By adding one or more selected from an epoxy compound, an amine compound, and a quaternary ammonium compound to the conductive polymer dispersion, a reaction product containing the conductive composite can be precipitated. Also, an individual polyanion that has not formed a conductive composite reacts and precipitates in the same manner. Anionic groups such as sulfonic acid groups of the reaction product precipitated in this step are hydrophobized by the added above compounds reacting to form any of the following substituents (A) to (C).

[0062] Excess anionic groups that do not participate in the doping of the polyanion are sometimes referred to as "some anionic groups" below. The following substituent (A) is formed by the reaction of some anionic groups and an epoxy compound. The following substituent (B) is formed by the reaction of some anionic groups and an amine compound. The following substituent (C) is formed by the reaction of some anionic groups and a quaternary ammonium compound.

[0063] (Substituent A) The substituent (A) is presumed to be a group represented by the following formula (A1) or a group represented by the following formula (A2).

[0064] [Chemical formula]

[0065] [In formula (A1), R 1 , R 2 , R 3 , and R 4 are each independently a hydrogen atom or an arbitrary substituent.]

[0066] [Chemical formula]

[0067] [In formula (A2), m is an integer of 2 or more, and a plurality of R 5 , a plurality of R 6 , a plurality of R 7 , and a plurality of R 8 are each independently a hydrogen atom or an arbitrary substituent, a plurality of R 5 may be the same or different, a plurality of R 6 may be the same or different, a plurality of R 7 may be the same or different, a plurality of R 8 may be the same or different.]

[0068] In formulas (A1) and (A2), the leftmost bond represents that the substituent (A) has replaced the proton of an anionic group such as a sulfonic acid group.

[0069] In formula (A1), R 1 , R 2 , R 3 , and R 4 Examples of any substituent of include an aliphatic hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, an aromatic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent, and the like. R 1 and R 3 may combine to form a ring which may have a substituent. For example, R 1 and R 3 are the hydrocarbon groups, and a divalent hydrocarbon group obtained by removing any one hydrogen atom from a monovalent hydrocarbon group of R 1 and a divalent hydrocarbon group obtained by removing any one hydrogen atom from a monovalent hydrocarbon group of R 3 are bonded to each other at the carbon atoms from which the hydrogen atoms have been removed to form a ring. In formula (A2), R 5 , R 6 , R 7 , and R 8 Examples of any substituent of include an aliphatic hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, an aromatic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent, and the like. R 5 and R 7 may combine to form a ring which may have a substituent. Examples of forming a ring are the same as above. Here, "which may have a substituent" includes both the case of substituting a hydrogen atom (-H) with a monovalent group and the case of substituting a methylene group (-CH2-) 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 (such as a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), a trialkoxysilyl group (such as a trimethoxysilyl group), and the like. Examples of the divalent group as a substituent include an oxygen atom (-O-), -C(=O)-, -C(=O)-O-, and the like. m is an integer of 2 or more, preferably from 2 to 100, more preferably from 2 to 50, and even more preferably from 2 to 25. When m is at least the above lower limit, the hydrophobicity of the conductive composite becomes sufficiently high. When m is at most the above upper limit, it is possible to suppress the hydrophobicity from becoming too high or the conductivity from decreasing.

[0070] The epoxy compound is a compound having one or more epoxy groups in one molecule (epoxy group-containing compound). In terms of preventing aggregation or gelation, the epoxy compound is preferably a compound having one epoxy group in one molecule. The epoxy compound that reacts with the partial anion groups may be one type or two or more types.

[0071] Examples of monofunctional epoxy compounds having one epoxy group in the 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, 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-glycidyloxypropyltrimethoxysilane, epoxy succinic 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, 2,2,2-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, glycidyl p-toluenesulfonate, ethyl 3-methyl-3-phenylglycidate, N-propyl-N-(2,3-epoxypropyl)perfluorooctanesulfonamide, (2S,3S)-1,2-epoxy-3-(tert-butoxycarbonylamino)-4-phenylbutane, (R)-glycidyl 3-nitrobenzenesulfonate, glycidyl 3-nitrobenzenesulfonate, parthenolide, N-glycidylphthalimide, endrin, dieldrin, 4-glycidyloxycarbazole, [oxiranylmethyl] 7,7-dimethyloctanoate, 1,2-epoxy-4-vinylcyclohexane, higher alcohol glycidyl ethers having 10 to 16 carbon atoms, etc. may be mentioned.,

[0072] As the higher alcohol glycidyl ether, one or more of higher alcohol glycidyl ethers having 10 to 16 carbon atoms are preferable, one or more of higher alcohol glycidyl ethers having 12 to 14 carbon atoms are more preferable, and at least one of C12 (12 carbon atoms) higher alcohol glycidyl ether and C13 (13 carbon atoms) higher alcohol glycidyl ether is even more preferable.

[0073] Examples of the polyfunctional epoxy compound 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 - cyclohexanedicarboxylic acid diglycidyl, isocyanuric acid triglycidyl, neopentyl glycol diglycidyl ether, 1,2:3,4 - diepoxybutane, polyethylene glycol diglycidyl ether, ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, propylene glycol 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, and the like.

[0074] Since the epoxy compound has high dispersibility in an organic solvent, it preferably has a molecular weight of 50 or more and 2000 or less. Further, since the epoxy compound has high dispersibility in a low - polarity hydrocarbon - based solvent or ester - based solvent, the epoxy compound preferably has 4 or more and 120 or less carbon atoms, more preferably 7 or more and 100 or less carbon atoms, still more preferably 10 or more and 80 or less carbon atoms, and particularly preferably 15 or more and 50 or less carbon atoms.

[0075] (Substituent B) The substituent (B) is presumed to be a group represented by the following formula (B).

[0076] -HN + R 11 R 12 R 13 ···(B) [In formula (B), R 11 ~R 13 are each independently a hydrogen atom or a hydrocarbon group which may have a substituent, provided that at least one of R 11 ~R 13 is a hydrocarbon group which may have a substituent.]

[0077] In the substituent (B), the leftmost bond represents that the negative charge of the anion group, for example, the negative charge of the sulfonic acid group "-SO3 - ", is bonded to the positive charge of the amine compound.

[0078] R 11 ~R 13 in the chemical formula (B) is a hydrogen atom or a hydrocarbon group which may have a substituent. R 11 ~R 13 in the chemical formula (B) is a substituent derived from the amine compound described later. Examples of the hydrocarbon group in the chemical 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, an octyl group and the like. Examples of the substituent of the aliphatic hydrocarbon group include a phenyl group, a hydroxyl group and the like. Examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group and the like. Examples of the substituent of the aromatic hydrocarbon group include an alkyl group having 1 to 5 carbon atoms, a hydroxyl group and the like.

[0079] The amine compound is at least one selected from the group consisting of a primary amine, a secondary amine and a tertiary amine. The amine compound that reacts with a part of the anion groups may be one kind or two or more kinds. Examples of the primary amine include aniline, toluidine, benzylamine, ethanolamine and the like. Examples of the secondary amine include diethanolamine, dimethylamine, diethylamine, dipropylamine, diphenylamine, dibenzylamine, dinaphthylamine, and the like. Examples of the tertiary amine include triethanolamine, trimethylamine, triethylamine, tripropylamine, tributylamine, trihexylamine, trioctylamine, triphenylamine, tribenzylamine, trinaphthylamine, and the like. Among the amine compounds, since the conductivity of the conductive composite of this embodiment can be enhanced, a tertiary amine is preferable, and at least one of trioctylamine and tributylamine is more preferable.

[0080] Since the dispersibility in an organic solvent, particularly the dispersibility in a low-polarity hydrocarbon solvent and ester solvent, is high, the amine compound preferably has a substituent having 4 or more carbon atoms on the nitrogen atom, more preferably has a substituent having 6 or more carbon atoms, and even more preferably has a substituent having 8 or more carbon atoms on the nitrogen atom. The upper limit value of the carbon number of the substituent on this nitrogen atom is not particularly limited, and in consideration of the solubility and reactivity in the solvent, for example, 50 or less is preferable, 40 or less is more preferable, and 30 or less is even more preferable. Also, the R 11 ~R 13 The total carbon number of is preferably 6 to 33, more preferably 9 to 30, and even more preferably 12 to 27. The carbon numbers of the substituents on the nitrogen atom may be the same or different.

[0081] When the partial anion group has a substituent (A) and a substituent (B), the mass ratio represented by [substituent (A)]:[substituent (B)] (hereinafter also referred to as the A / B ratio) is preferably 10:90 to 90:10, more preferably 20:80 to 80:20, and even more preferably 25:75 to 75:25. When the A / B ratio is within the above range, it becomes easier to balance the dispersibility and conductivity. The mass of [substituent (A)] can be calculated by [(the mass of reaction product A obtained by reacting with an epoxy compound) - (the mass of the conductive composite before reacting with the epoxy compound and the mass of the polyanion not forming the conductive composite)]. The mass of [substituent (B)] can be calculated from [(the mass of reaction product B obtained by reacting the reaction product A with an amine compound) - (the mass of the reaction product A)].

[0082] (Substituent C) The substituent (C) is presumed to be a group represented by the following formula (C).

[0083] -N + R 11 R 12 R 13 R 14 ···(C) [In formula (C), R 11 ~R 14 are each independently a hydrocarbon group which may have a substituent.]

[0084] In the substituent (C), the leftmost bond represents that the negative charge of the anion group, for example, the negative charge of the sulfonic acid group "-SO3 - ", is bonded to the positive charge of the quaternary ammonium cation.

[0085] R 11 ~R 14 in chemical formula (C) is a hydrocarbon group which may have a substituent. R 11 ~R 14 in chemical formula (C) are substituents derived from a quaternary ammonium compound. The hydrocarbon group in the chemical formula (C) includes 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, an octyl group, etc. Examples of the substituent of the aliphatic hydrocarbon group include a phenyl group, a hydroxyl group, etc. Examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, etc. Examples of the substituent of the aromatic hydrocarbon group include an alkyl group having 1 to 5 carbon atoms, a hydroxyl group, etc.

[0086] Since the quaternary ammonium compound has high dispersibility in an organic solvent and improved conductivity, it preferably has a substituent having 3 or more carbon atoms on the nitrogen atom, more preferably has a substituent having 5 or more carbon atoms, and even more preferably has a substituent having 7 or more carbon atoms on the nitrogen atom. The upper limit value of the carbon number of each substituent on this nitrogen atom is not particularly limited, and in consideration of solubility and reactivity in a solvent, for example, 40 or less is preferable, 30 or less is more preferable, and 20 or less is even more preferable. Further, the R 11 ~R 14 of the quaternary ammonium compound preferably has a total carbon number of 8 to 44, more preferably 12 to 40, and even more preferably 16 to 36. The carbon numbers of each substituent on the nitrogen atom may be the same or different.

[0087] Specific examples of the quaternary ammonium compound include quaternary ammonium salts such as tetramethylammonium salt, tetraethylammonium salt, tetrapropylammonium salt, tetrabutylammonium salt, tetra-n-octylammonium salt, tetraphenylammonium salt, tetrabenzylammonium salt, tetranaphthylammonium salt. Examples of the counter anion of the ammonium cation include halogen ions such as bromide ion and chloride ion, and hydroxy ion.

[0088] When the conductive composite has substituent (A) and substituent (C), the mass ratio represented by [substituent (A)]:[substituent (C)] (hereinafter also referred to as A / C ratio) is preferably 10:90 to 90:10, more preferably 20:80 to 80:20, and still more preferably 25:75 to 75:25. When the A / C ratio is within the above range, it becomes easier to balance dispersibility and conductivity. The mass of [substituent (A)] can be calculated by [(the mass of reaction product A obtained by reacting with an epoxy compound) - (the mass of the conductive composite before reacting with the epoxy compound and the polyanion not forming the conductive composite)]. Also, the mass of [substituent (C)] can be calculated from [(the mass of reaction product C obtained by reacting the reaction product A with a quaternary ammonium compound) - (the mass of the reaction product A)].

[0089] When adding one or more epoxy compounds to the conductive polymer dispersion, the addition amount of the epoxy compound is preferably 10 parts by mass or more and 10000 parts by mass or less, more preferably 100 parts by mass or more and 5000 parts by mass or less, and still more preferably 500 parts by mass or more and 3000 parts by mass or less with respect to 100 parts by mass of the π-conjugated conductive polymer and all polyanions (including the polyanion forming the conductive composite) contained in the conductive polymer dispersion. When it is at or above the lower limit value of the above range, the hydrophobicity of the conductive composite becomes sufficiently high, and the dispersibility in the organic solvent is improved. When it is at or below the upper limit value of the above range, a decrease in conductivity due to unreacted epoxy compound can be prevented. When adding the epoxy compound, heating may be performed to promote the reaction. The heating temperature is preferably 40°C or higher and 100°C or lower.

[0090] When adding one or more amine compounds to the conductive polymer dispersion, the addition amount of the amine compound is preferably 1 part by mass or more and 10,000 parts by mass or less, more preferably 10 parts by mass or more and 5,000 parts by mass or less, and even more preferably 100 parts by mass or more and 2,000 parts by mass or less, based on 100 parts by mass of the π-conjugated conductive polymer and all polyanions (including the polyanions forming the conductive complex) contained in the conductive polymer dispersion. When it is at or above the lower limit value of the above range, the hydrophobicity of the conductive complex becomes sufficiently high, and the dispersibility in the organic solvent is improved. When it is at or below the upper limit value of the above range, a decrease in conductivity due to the unreacted amine compound can be prevented.

[0091] When adding one or more quaternary ammonium compounds to the conductive polymer dispersion, the addition amount of the quaternary ammonium compound is preferably 1 part by mass or more and 10,000 parts by mass or less, more preferably 10 parts by mass or more and 5,000 parts by mass or less, and even more preferably 50 parts by mass or more and 2,000 parts by mass or less, based on 100 parts by mass of the π-conjugated conductive polymer and all polyanions (including the polyanions forming the conductive complex) contained in the conductive polymer dispersion. When it is at or above the lower limit value of the above range, the hydrophobicity of the conductive complex becomes sufficiently high, and the dispersibility in the organic solvent is improved. When it is at or below the upper limit value of the above range, a decrease in conductivity due to the unreacted quaternary ammonium compound can be prevented. The quaternary ammonium compound shows good reactivity with an addition amount less than that of the amine compound in a reaction mechanism similar to that of the amine compound. The conductivity of the conductive layer containing the conductive complex modified by the quaternary ammonium compound tends to be superior to that when modified by the amine compound.

[0092] Before adding one or more selected from an epoxy compound, an amine compound, and a quaternary ammonium compound to the conductive polymer dispersion, an organic solvent may be added before, simultaneously with, or after the addition. As the organic solvent, a water-soluble organic solvent is preferable. Examples of the water-soluble organic solvent include an alcohol-based solvent, a ketone-based solvent, and an ester-based solvent. The organic solvent to be added may be one type or two or more types.

[0093] When both an epoxy compound and an amine compound or a quaternary ammonium compound are added to the conductive polymer dispersion, the addition order is not particularly limited. Since it is easy to handle the synthetic intermediate (reaction intermediate), it is preferable to first add the epoxy compound and react it, and then add the amine compound or the quaternary ammonium compound and react it.

[0094] [Recovery step] The method for recovering the precipitated reaction product is not particularly limited, and it can be recovered, for example, by filtration treatment, decantation, etc.

[0095] The water content of the recovered reaction product (precipitate) is preferably as low as possible, and most preferably contains no water at all. However, from a practical point of view, it may contain water in the range of 10% by mass or less. Examples of the method for reducing the water content include a method of washing away the reaction product with an organic solvent and a method of drying the reaction product.

[0096] [Washing step] A washing step of washing the reaction product recovered in the recovery step may be included. By this washing step, residual water, unreacted epoxy compound, unreacted amine compound or quaternary ammonium compound, and hydrolysis products of the epoxy compound are removed. The organic solvent for washing is preferably one that can wash while minimizing the dissolution of the reaction product. For this reason, an alcohol-based solvent is preferable as the organic solvent for washing. The organic solvent contained in the organic solvent for washing may be one type or two or more types. The washing method is not particularly limited. For example, the reaction product may be washed by pouring a washing organic solvent from above the reaction product, or the reaction product may be washed by stirring in the washing organic solvent.

[0097] [Addition step] This step is a step of adding a dispersion medium to the reaction product to obtain a conductive polymer-containing liquid. The dispersion medium to be added may be any one that can disperse the reaction product, and preferably contains an organic solvent. When the conductive polymer-containing liquid contains a hydrophobized conductive composite, the content of the organic solvent with respect to the total mass of the dispersion medium is preferably 70% by mass or more and 100% by mass or less, more preferably 80% by mass or more and 100% by mass or less, and still more preferably 90% by mass or more and 100% by mass or less.

[0098] The content of the reaction product with respect to the total mass of the conductive polymer-containing liquid obtained in this step is preferably, for example, 0.01% by mass or more and 10% by mass or less, more preferably 0.1% by mass or more and 3% by mass or less, and still more preferably 0.2% by mass or more and 1% by mass or less. When it is at or above the lower limit value of the above range, the conductivity of the conductive layer formed by coating the conductive polymer-containing liquid can be further improved. When it is at or below the upper limit value of the above range, the dispersibility of the reaction product in the conductive polymer-containing liquid can be enhanced, and a uniform conductive layer can be formed.

[0099] <Organic solvent> Examples of the organic solvent include alcohol solvents, ether solvents, ketone solvents, ester solvents, hydrocarbon solvents, nitrogen atom-containing compound solvents, and the like. The organic solvent may be of one type or two or more types.

[0100] The organic solvent may be a water-soluble organic solvent or a water-insoluble organic solvent. A water-soluble organic solvent is an organic solvent with a solubility of 1 g or more in 100 g of water at 20°C, and a water-insoluble organic solvent is an organic solvent with a solubility of less than 1 g in 100 g of water at 20°C. As the water-soluble organic solvent, one or more selected from alcohol-based solvents are preferred.

[0101] Examples of alcohol-based solvents include monohydric alcohols such as methanol, ethanol, 1-propanol, 2-propanol, 2-methyl-2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol, allyl alcohol, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, etc.; and dihydric alcohols such as ethylene glycol, propylene glycol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, etc. Examples of ether-based solvents include diethyl ether, dimethyl ether, propylene glycol dialkyl ether, etc. Examples of ketone-based solvents include diethyl ketone, methyl propyl ketone, methyl butyl ketone, methyl isopropyl ketone, methyl isobutyl ketone, methyl amyl ketone, diisopropyl ketone, methyl ethyl ketone, acetone, diacetone alcohol, etc. Examples of ester-based solvents and hydrocarbon-based solvents will be described later. Examples of nitrogen atom-containing compound-based solvents include N-methylpyrrolidone, dimethylacetamide, dimethylformamide, etc. Examples of solvents not classified above include dimethyl sulfoxide.

[0102] (Ester-based solvent) An ester-based solvent is an ester group-containing compound having an ester group (-C(=O)-O-). When the conductive composite is modified by reaction with an epoxy compound and an amine compound or a quaternary ammonium compound, it is preferable that the organic solvent contains an ester-based solvent because the dispersibility of the conductive composite is further enhanced. From the viewpoint of enhancing the dispersibility of the conductive composite, it is preferably contained one or more ester solvents represented by the following formula 1z. Formula 1z: R 21 -C(=O)-O-R 22 [In the formula, R 21 represents a hydrogen atom, a methyl group or an ethyl group, and R 22 represents a linear or branched alkyl group having 1 to 6 carbon atoms.]

[0103] From the viewpoint of enhancing the dispersibility of the conductive composite, R 21 is preferably a methyl group or an ethyl group, more preferably a methyl group. Also, the number of carbon atoms of R 22 is preferably 2 to 5, more preferably 2 to 4.

[0104] Examples of the ester solvent include ethyl acetate, propyl acetate, butyl acetate, isopropyl acetate, isobutyl acetate and the like.

[0105] The content of the ester solvent contained in the organic solvent is preferably 40% by mass or more, more preferably 50% by mass or more, further preferably 60% by mass or more, still more preferably 70% by mass or more, particularly preferably 80% by mass or more, most preferably 90% by mass or more, and may even be 100% by mass, based on the total mass of the organic solvent. When the content of the ester solvent is within the above range, the dispersibility of the conductive composite can be enhanced.

[0106] When the conductive polymer-containing liquid of this embodiment contains an ester solvent, one or more organic solvents other than the ester solvent may be further contained. Examples of the organic solvents other than the ester solvent include hydrocarbon solvents described below, ketone solvents described above, alcohol solvents, nitrogen atom-containing compound solvents and the like.

[0107] (Hydrocarbon solvent) When the conductive composite contained in the conductive polymer-containing liquid of this aspect is modified by reaction with an epoxy compound and an amine compound or a quaternary ammonium compound, if a hydrocarbon solvent is included as the dispersion medium, the wettability with respect to the plastic film substrate is increased, and a low-polarity binder component can be easily added, which is preferable.

[0108] Examples of the hydrocarbon solvent include aliphatic hydrocarbon solvents and aromatic hydrocarbon solvents. Examples of the aliphatic hydrocarbon solvent include pentane, hexane, heptane, octane, decane, cyclohexane, methylcyclohexane, and the like. Examples of the aromatic hydrocarbon solvent include benzene, toluene, xylene, ethylbenzene, propylbenzene, isopropylbenzene, and the like. Among them, toluene is preferable because of the high dispersibility of the conductive composite. Further, when a silicone compound is added as the binder component, at least one of heptane and toluene is preferable because of the excellent solubility of the silicone compound.

[0109] It is preferable to further contain methyl ethyl ketone in addition to the hydrocarbon solvent because the dispersibility of the conductive composite becomes higher. For example, with respect to 100 parts by mass of the hydrocarbon solvent, the amount of methyl ethyl ketone is preferably 20 parts by mass or more and 120 parts by mass or less, more preferably 30 parts by mass or more and 100 parts by mass or less, and even more preferably 40 parts by mass or more and 80 parts by mass or less.

[0110] The content of the hydrocarbon solvent is preferably 40% by mass or more, more preferably 50% by mass or more, even more preferably 60% by mass or more, still more preferably 70% by mass or more, particularly preferably 80% by mass or more, most preferably 90% by mass or more, and may be 100% by mass, based on the total mass of the organic solvents. When the content of the hydrocarbon solvent is within the above range, the dispersibility of the conductive composite can be enhanced.

[0111] When the conductive polymer-containing liquid of this aspect contains a hydrocarbon solvent, one or more organic solvents other than the hydrocarbon solvent may be further included. Examples of organic solvents other than hydrocarbon solvents include the ketone solvents, alcohol solvents, ester solvents, nitrogen atom-containing compound solvents, etc. described above.

[0112] Among these, the organic solvent is preferably at least one selected from alcohol solvents, ketone solvents, and ester solvents, and more preferably at least one selected from isopropanol, methyl ethyl ketone, and ethyl acetate. By using these suitable organic solvents, the dispersibility of the conductive composite contained in the conductive polymer-containing liquid can be further enhanced.

[0113] (Dispersion treatment) After adding a dispersion medium to the reaction product, the conductive polymer-containing liquid may be stirred to perform a dispersion treatment. The stirring method is not particularly limited, and it may be stirring with a weak shearing force such as a stirrer, or stirring may be performed using a disperser with a high shearing force such as a high-pressure homogenizer. However, from the viewpoint of enhancing the dispersibility, it is preferable to use a high-pressure homogenizer or the like.

[0114] (Addition of optional components) A binder component or other additives may be further added to the conductive polymer-containing liquid obtained above.

[0115] (Addition of binder component) The conductive polymer-containing liquid of this embodiment may further contain a binder component. By using a conductive polymer-containing liquid containing a binder component, the strength of the conductive layer to be formed can be improved, or adhesiveness or releasability can be imparted. 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 cures during the formation of the conductive layer. The thermoplastic resin directly becomes the binder resin, and the resin formed by curing of the curable monomer or oligomer becomes the binder resin. The binder component may be an adhesive described later. The binder component added in this embodiment may be one type or two or more types.

[0116] Specific examples of the binder resin derived from the binder component include, for example, epoxy resin, acrylic resin (acrylic compound), polyester resin, polyurethane resin, polyimide resin, polyether resin, melamine resin, silicone, and the like.

[0117] The curable monomer or oligomer may be a thermosetting monomer or oligomer, or may be a photocurable monomer or oligomer. Here, the oligomer is a polymer having a mass average molecular weight of less than 10,000. Examples of the curable monomer include, for example, acrylic monomer (acrylic compound), epoxy monomer, organosiloxane, and the like. Examples of the curable oligomer include, for example, acrylic oligomer (acrylic compound), epoxy oligomer, silicone oligomer (curable silicone), and the like. When an acrylic monomer or acrylic oligomer is used as the binder component, it can be easily cured by heating or light irradiation.

[0118] When a curable monomer or oligomer is included, it is preferably further included with a curing catalyst. For example, when a thermosetting monomer or oligomer is included, it is preferably included with a thermal polymerization initiator that generates radicals by heating, and when a photocurable monomer or oligomer is included, it is preferably included with a photopolymerization initiator that generates radicals by light irradiation.

[0119] The content ratio of the binder component (excluding the silicone compound described later) contained in the conductive polymer-containing liquid of this embodiment is preferably, for example, 1 part by mass or more and 10,000 parts by mass or less, more preferably 10 parts by mass or more and 5000 parts by mass or less, and even more preferably 100 parts by mass or more and 1000 parts by mass or less, based on 1 part by mass of the π-conjugated conductive polymer and the total polyanion. When it is at or above the lower limit value of the above range, the characteristics of the binder component contained in the conductive layer formed by the conductive polymer-containing liquid of this embodiment can be sufficiently exhibited. When it is below the upper limit value of the above range, sufficient conductivity of the conductive layer formed by the conductive polymer-containing liquid of this embodiment can be ensured.

[0120] (Silicone compound) When the dispersion medium of the conductive polymer-containing liquid of this embodiment contains a hydrocarbon-based solvent or an ester-based solvent, the dispersibility of the silicone compound is preferably enhanced. Examples of the silicone compound include curable silicones. When the binder component is a curable silicone, mold release properties can be imparted to the conductive layer by curing the curable silicone.

[0121] The curable silicone may be either an addition-curable silicone or a condensation-curable silicone. In this embodiment, an addition-curable silicone is preferred because curing inhibition is less likely to occur when it is used.

[0122] Examples of the addition-curable silicone include linear polymers having siloxane bonds and having vinyl groups at both ends of the linear chain, and those having a hydrogen silane. Such addition-curable silicones form a three-dimensional crosslinked structure by an addition reaction and cure. A platinum-based curing catalyst may be used to accelerate the curing. Specific examples of the addition-curable silicone include KS-3703T, KS-847T, KM-3951, X-52-151, X-52-6068, X-52-6069 (manufactured by Shin-Etsu Chemical Co., Ltd.), etc. Addition-curable silicones that are dissolved or dispersed in an organic solvent are preferably used.

[0123] The content ratio of the silicone compound contained in the conductive polymer-containing liquid of this embodiment is preferably 10 parts by mass or more and 10,000 parts by mass or less, more preferably 100 parts by mass or more and 5,000 parts by mass or less, and even more preferably 500 parts by mass or more and 3,000 parts by mass or less, based on 100 parts by mass of the π-conjugated conductive polymer and the total polyanion. When it is equal to or higher than the lower limit value of the above range, sufficient releasability can be imparted to the conductive layer formed by the conductive polymer-containing liquid of this embodiment. When it is equal to or lower than the upper limit value of the above range, sufficient conductivity of the conductive layer formed by the conductive polymer-containing liquid of this embodiment can be ensured.

[0124] [Adhesive] The conductive polymer-containing liquid of this embodiment may contain an adhesive as a binder component. By using a conductive polymer-containing liquid containing an adhesive, a conductive layer having adhesiveness can be formed. When the dispersion medium of the conductive polymer-containing liquid of this embodiment contains a hydrocarbon solvent or an ester solvent, it can be easily mixed with an adhesive preliminarily dispersed in the hydrocarbon solvent or the ester solvent, and the conductive composite can be stably dispersed in the mixed liquid, which is preferable.

[0125] The degree of adhesiveness of the adhesive is not particularly limited, and it may have an adhesiveness that can be easily peeled off by hand after being pasted, or an adhesiveness that is difficult to peel off after being pasted. The adhesiveness that is difficult to peel off can be regarded as adhesiveness. That is, the adhesiveness may be such that it can adhere semi-permanently.

[0126] As the adhesive, known adhesives can be applied. From the viewpoint of exhibiting good adhesiveness while maintaining conductivity, an acrylic adhesive is preferable.

[0127] (Acrylic adhesive) The acrylic adhesive can bond and integrate the surfaces of the same or different solids. The acrylic adhesive contains an acrylic resin (acrylic polymer).

[0128] Specific examples of acrylic monomers that form acrylic resins include acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, 2-methoxyethyl acrylate, ditrimethylolpropane tetraacrylate, 2-hydroxy-3-phenoxypropyl acrylate, bisphenol A·ethylene oxide modified diacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, dipentaerythritol monohydroxy pentaacrylate, dipropylene glycol diacrylate, trimethylolpropane triacrylate, glycerin propoxytriacrylate, 4-hydroxybutyl acrylate, 1,6-hexanediol diacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, isobornyl acrylate, polyethylene glycol diacrylate, pentaerythritol triacrylate, tetrahydrofurfuryl acrylate, tripropylene glycol diacrylate, and other acrylates; tetraethylene glycol dimethacrylate, methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, t-butyl methacrylate, allyl methacrylate, 1,3-butylene glycol dimethacrylate, benzyl methacrylate, cyclohexyl methacrylate, diethylene glycol dimethacrylate, 2-ethylhexyl methacrylate, glycidyl methacrylate, 1,6-hexanediol dimethacrylate, 2-hydroxyethyl methacrylate, isobornyl methacrylate, lauryl methacrylate, phenoxyethyl methacrylate, tetrahydrofurfuryl methacrylate, trimethylolpropane trimethacrylate, and other methacrylates;Examples of (meth)acrylamide include diacetone acrylamide, N,N-dimethylacrylamide, dimethylaminopropylacrylamide, dimethylaminopropylmethacrylamide, methacrylamide, N-methylolacrylamide, acryloyl morpholine, N-methylacrylamide, N-isopropylacrylamide, N-t-butylacrylamide, N-phenylacrylamide, acryloyl piperidine, 2-hydroxyethylacrylamide, etc.; The acrylic monomer forming the acrylic resin may be one kind or two or more kinds. By combining two or more acrylic monomers, the adhesiveness can be adjusted.

[0129] The acrylic resin may be a copolymer of an acrylic monomer and a vinyl monomer other than the acrylic monomer. Examples of the vinyl monomer include styrene, α-methylstyrene, vinyl acetate, acrylonitrile, methacrylonitrile, maleic anhydride, etc. The content of the acrylic monomer unit in the above copolymer is preferably 50 mol% or more and less than 100 mol%, more preferably 70 mol% or more and 98 mol% or less. If the content of the acrylic monomer unit is at least the above lower limit value, the adhesiveness can be easily exhibited. The content of the vinyl monomer unit in the above copolymer can be, for example, 2 mol% or more and 20 mol% or less.

[0130] The glass transition temperature of the acrylic resin is preferably 80°C or lower, more preferably 50°C or lower, and still more preferably 0°C or lower. An acrylic resin with a glass transition temperature exceeding 80°C has low adhesiveness. The glass transition temperature of the acrylic resin is -80°C or higher, and it is difficult to obtain one with a lower glass transition temperature. The glass transition temperature of the acrylic resin can be determined by differential scanning calorimetry or dynamic viscoelasticity measurement. As acrylic monomers having a tendency to lower the glass transition temperature of the acrylic resin, for example, ethyl acrylate, butyl acrylate (especially n-butyl acrylate), 2-ethylhexyl acrylate, etc. can be mentioned. In the acrylic resin, the higher the proportion of these monomer units, the lower the glass transition temperature.

[0131] The mass average molecular weight of the acrylic resin is preferably 10,000 or more and 2,000,000 or less, and more preferably 30,000 or more and 1,000,000 or less. If the mass average molecular weight of the acrylic resin is at least the lower limit value, sufficient cohesive force can be ensured. If it is at most the upper limit value, the adhesiveness can be further improved.

[0132] When the acrylic resin has an acrylic monomer unit having a reactive functional group, it may be reacted with a curing agent to be cured. When the acrylic resin is cured, the cohesive force of the conductive layer containing the adhesive can be improved and the strength can be improved. Also, by improving the cohesive force of the conductive layer, a re-peelable conductive layer capable of repeating adhesion and peeling can be obtained. Examples of the reactive functional group include a hydroxy group, a carboxy group, an amino group, an amide group, an epoxy group, etc. When reacting with a polyfunctional isocyanate described later, the reactive functional group is preferably a hydroxy group, a carboxy group, an amino group, and more preferably a hydroxy group. Examples of the acrylic monomer having a hydroxy group include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate, 4-hydroxybutyl acrylate, 4-hydroxybutyl methacrylate, etc. Examples of the acrylic monomer having a carboxy group include acrylic acid, methacrylic acid, itaconic acid, etc. Examples of the acrylic monomer having an amino group include dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, and the like. Examples of the acrylic monomer having an amide group include acrylamide, methacrylamide, N-methylolacrylamide, N-methylolmethacrylamide, and the like. Examples of the acrylic monomer having an epoxy group include glycidyl acrylate, glycidyl methacrylate, and the like. When a polyfunctional isocyanate is used as the curing agent, among the acrylic monomers having the reactive functional groups, considering the curability and cost, an acrylic monomer having a hydroxy group is preferred, and 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate are more preferred. The acrylic monomer having the reactive functional group that forms the acrylic resin may be one kind or two or more kinds.

[0133] The content ratio of the adhesive contained in the conductive polymer-containing liquid of this embodiment is preferably 10 parts by mass or more and 10000 parts by mass or less, more preferably 100 parts by mass or more and 5000 parts by mass or less, and even more preferably 300 parts by mass or more and 1000 parts by mass or less with respect to 1 part by mass of the π-conjugated conductive polymer and the total polyanion. When it is at or above the lower limit value of the above range, sufficient adhesiveness can be imparted to the conductive layer formed by the conductive polymer-containing liquid of this embodiment. When it is at or below the upper limit value of the above range, sufficient conductivity of the conductive layer formed by the conductive polymer-containing liquid of this embodiment can be ensured.

[0134] (Curing agent) When the adhesive contained in the conductive polymer-containing liquid of this embodiment has a reactive functional group, it is preferable that the conductive polymer-containing liquid of this embodiment contains a curing agent. Examples of the curing agent include isocyanate-based curing agents such as polyfunctional isocyanates having two or more isocyanate groups in one molecule, and epoxy-based curing agents such as epoxy compounds having two or more epoxy groups in one molecule. Among these curing agents, polyfunctional isocyanates are preferred from the viewpoint of reactivity. In particular, when the adhesive has an acrylic monomer unit having a hydroxy group, it is preferable that the curing agent is a polyfunctional isocyanate.

[0135] Examples of the polyfunctional isocyanate include aliphatic polyfunctional isocyanates, alicyclic polyfunctional isocyanates, and aromatic polyfunctional isocyanates. Specific examples of the polyfunctional isocyanate include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, polyphenylene polymethylene polyisocyanate, 1,6-hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, p-phenylene diisocyanate, trans-cyclohexane 1,4-diisocyanate, 4,4'-dicyclomethane diisocyanate, 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, dianisidine diisocyanate, m-xylylene diisocyanate, isophorone diisocyanate, 1,5-naphthalene diisocyanate, 1,4-cyclohexane diisocyanate, lysine diisocyanate, lysine ester triisocyanate, tetramethylxylylene diisocyanate, 1,6,11-undecane triisocyanate, 1,3,6-hexamethylene triisocyanate, bicycloheptane triisocyanate, trimethylhexamethylene diisocyanate, and the like. The polyfunctional isocyanate may be a modified diisocyanate formed from the modified polyfunctional isocyanate obtained by modifying the diisocyanate so that the NCO / OH molar ratio is 2 / 1 or more. The polyfunctional isocyanate may be a modified polyisocyanate. Examples of the modified polyisocyanate include polyurethane polyisocyanate obtained by reacting the polyfunctional isocyanate with a polyhydric alcohol, polyisocyanate containing an isocyanurate ring obtained by polymerizing the polyfunctional isocyanate, polyisocyanate containing a biuret bond obtained by reacting the polyfunctional isocyanate with water, and the like. The type of the curing agent contained in the conductive polymer-containing liquid of this embodiment may be one type or two or more types.

[0136] The content ratio of the curing agent contained in the conductive polymer-containing liquid of this embodiment is preferably, for example, 1 part by mass or more and 100 parts by mass or less, more preferably 2 parts by mass or more and 50 parts by mass or less, and even more preferably 3 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the adhesive. When it is within the above range, sufficient adhesiveness can be imparted to the conductive layer formed by the conductive polymer-containing liquid of this embodiment.

[0137] (High conductivity agent) The conductive polymer-containing liquid of this embodiment may contain a high conductivity agent. Here, the above-described π-conjugated conductive polymer, polyanion, organic solvent, adhesive, curing agent, and binder component are not classified as high conductivity agents. Note that the epoxy compound, the amine compound, and the quaternary ammonium compound may correspond to the high conductivity agent described herein. The high conductivity agent is preferably at least one compound selected from the group consisting of saccharides, nitrogen-containing aromatic cyclic compounds, compounds having two or more hydroxyl groups, compounds having one or more hydroxyl groups and one or more carboxyl groups, compounds having an amide group, compounds having an imide group, lactam compounds, and compounds having a glycidyl group. The high conductivity agent contained in the conductive polymer-containing liquid of this embodiment may be one type or two or more types. The content ratio of the conductivity improver is preferably 1 part by mass or more and 10,000 parts by mass or less, more preferably 10 parts by mass or more and 5,000 parts by mass or less, and even more preferably 100 parts by mass or more and 2,500 parts by mass or less with respect to 100 parts by mass of the π-conjugated conductive polymer and the total polyanion. If the content ratio of the conductivity improver is equal to or higher than the lower limit value, the effect of improving conductivity by adding the conductivity improver can be fully exerted. If it is equal to or lower than the upper limit value, a decrease in conductivity due to a decrease in the concentration of the π-conjugated conductive polymer can be prevented.

[0138] (Other additives) The conductive polymer-containing liquid of this embodiment may contain other known additives. Since the description of other additives is the same as above, the overlapping description is omitted here.

[0139] ≪Conductive laminate≫ The third aspect of the present invention is a conductive laminate including a base material and a conductive layer formed of a cured layer of the conductive polymer-containing liquid of the first aspect on at least a part of the surface of the base material. The above conductive polymer-containing liquid may be a conductive polymer-containing liquid containing a hydrophobized conductive composite produced by the production method of the second aspect.

[0140] [Conductive layer] The formation range of the conductive layer may be the entire surface of any surface of the base material or a part thereof. In the case of a conductive film, it is preferable that a conductive layer with a substantially uniform thickness is formed on substantially the entire surface of one side or the other side of the film base material. When the conductive layer is formed only on a part of the surface of the base material, for example, the conductive layer may be a fine conductive pattern such as a circuit or an electrode, or the region where the conductive layer is provided and the region where it is not provided may exist on the same surface and be roughly divided.

[0141] The average thickness of the conductive layer is, for example, preferably 10 nm or more and 100 μm or less, more preferably 20 nm or more and 50 μm or less, and even more preferably 30 nm or more and 30 μm or less. If the average thickness of the conductive layer is equal to or greater than the lower limit value, high conductivity can be exhibited. If it is equal to or less than the upper limit value, the adhesion of the conductive layer to the base material is further improved. The average thickness of the conductive layer is a value obtained by measuring the thickness at 10 randomly selected locations and averaging the measured values.

[0142] [Base material] The base material may be a base material made of an insulating material or a base material made of a conductive material. The shape of the base material is not particularly limited, and examples include shapes mainly composed of a plane such as a film or a substrate. Examples of the insulating material include glass, synthetic resin, and ceramics. Examples of the conductive material include metal, conductive metal oxide, and carbon.

[0143] (Film substrate) When a film substrate is used as the base material, the conductive laminate becomes a conductive film. Examples of the film substrate include plastic films made of synthetic resin. Examples of the synthetic resin 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, and the like. From the viewpoint of enhancing the adhesion between the film substrate and the conductive layer, the synthetic resin for the film substrate is preferably a polyester resin, and among them, polyethylene terephthalate is preferred.

[0144] The synthetic resin for the film substrate may be amorphous or crystalline. The film substrate may be unstretched or stretched. The film substrate may be subjected to surface treatment such as corona discharge treatment, plasma treatment, flame treatment, etc. in order to further improve the adhesion of the conductive layer.

[0145] The average thickness of the film substrate is preferably 5 μm or more and 500 μm or less, more preferably 20 μm or more and 200 μm or less. If the average thickness of the film substrate is at least the lower limit value, it becomes difficult to break, and if it is at most the upper limit value, sufficient flexibility as a film can be ensured. The average thickness of the film substrate is a value obtained by measuring the thickness at 10 randomly selected locations and averaging the measured values.

[0146] (Glass substrate) Examples of the glass substrate include an alkali-free glass substrate, a soda-lime glass substrate, a borosilicate glass substrate, a quartz glass substrate, etc. When the substrate contains an alkali component, the conductivity of the conductive layer tends to decrease. Therefore, among the above glass substrates, an alkali-free glass is preferred. Here, the alkali-free glass is a glass composition in which the content of the alkali component is 0.1% by mass or less based on the total mass of the glass composition.

[0147] The average thickness of the glass substrate is preferably 100 μm or more and 3000 μm or less, more preferably 100 μm or more and 1000 μm or less. If the average thickness of the glass substrate is at least the lower limit value, it becomes difficult to break, and if it is at most the upper limit value, it can contribute to thinning of the conductive laminate. The average thickness of the glass substrate is a value obtained by measuring the thickness at 10 randomly selected locations and averaging the measured values.

[0148] <<Manufacturing method of conductive laminate>> The fourth aspect of the present invention is a method for manufacturing a conductive laminate, which includes a step of obtaining a conductive polymer-containing liquid containing a hydrophobized conductive composite by the manufacturing method of the second aspect, and a step of applying the conductive polymer-containing liquid to at least a part of the surface of a substrate. The conductive polymer-containing liquid applied in the above process may be a conductive polymer-containing liquid containing the non-hydrophobized conductive composite of the first aspect.

[0149] Since the description of the substrate is the same as above, the overlapping description is omitted here.

[0150] As a method of applying (coating) the conductive polymer-containing liquid onto any surface of the substrate, for example, methods using coaters such as 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, screen coater, etc., methods using sprayers such as air spray, airless spray, rotor dump spraying, etc., dipping methods such as dip, etc. can be applied.

[0151] The coating amount of the conductive polymer-containing liquid on the substrate is not particularly limited, but considering uniform coating without unevenness and conductivity and film strength, as a solid content, it is preferably in the range of 0.01 g / m 2 or more and 10.0 g / m 2 or less.

[0152] A conductive layer can be formed by drying the coating film composed of the conductive polymer-containing liquid applied on the substrate to remove at least a part of the dispersion medium and then curing it. Examples of the method for drying the coating film include heat drying and vacuum drying. As heat drying, for example, methods such as hot air heating and infrared heating can be adopted. When applying heat drying, the heating temperature is appropriately set according to the dispersion medium used, but usually it is in the range of 50°C or more and 200°C or less. Here, the heating temperature is the set temperature of the drying device. As the preferred drying time in the above heating temperature range, it is preferably 0.5 minutes or more and 30 minutes or less, and more preferably 1 minute or more and 15 minutes or less. After drying, UV irradiation may be performed to cure the binder component contained in the coating film.

[0153] The formation range of the conductive layer may be the entire surface or a part of any surface of the substrate. In the conductive film, it is preferable that a conductive layer with a substantially uniform thickness is formed on substantially the entire one surface or the other surface of the film substrate. When the conductive layer is formed only on a part of the surface of the substrate, for example, the conductive layer may be a fine conductive pattern such as a circuit or an electrode, or the region where the conductive layer is provided and the region where it is not provided may exist on the same surface and be roughly divided.

[0154] Since the description of the average thickness of the conductive layer is the same as described above, the overlapping description is omitted here.

[0155] ≪Use of the conductive polymer-containing liquid≫ The fifth aspect of the present invention is a method of using the conductive polymer-containing liquid of the first aspect after gently storing it at 40 ° C or higher for 720 hours or more, and using the conductive polymer-containing liquid after the storage as a material for the production method of the conductive polymer-containing liquid of the second aspect, as a material for the conductive layer of the conductive laminate of the third aspect, or as a material for the production method of the conductive laminate of the fourth aspect. Since the conductive polymer-containing liquid of the first aspect contains a molecular weight maintaining agent, it is stable even under the above storage conditions and can form a conductive layer with sufficient atmospheric exposure resistance. The standard upper limit value of the temperature of the above storage conditions is 50 ° C or lower or 60 ° C or lower, and the upper limit value of the storage period (hours) is not particularly limited, but examples of the standard include 1000 hours or less, 2000 hours or less, or 3000 hours.

Examples

[0156] (Production Example 1) Production of polystyrene sulfonic acid 1 206 g of sodium styrene sulfonate was dissolved in 1000 ml of ion-exchanged water, and while stirring at 80 ° C, a 1.14 g ammonium persulfate oxidizing agent solution previously dissolved in 10 ml of water was added dropwise over 20 minutes, and this solution was stirred for 12 hours. To the obtained sodium polystyrene sulfonate solution, 1000 ml of sulfuric acid diluted to 10% by mass was added, and approximately 1000 ml of the solvent of the obtained polystyrene sulfonic acid solution was removed by ultrafiltration. Next, 2000 ml of ion-exchanged water was added to the residue, and approximately 2000 ml of the solvent was removed by ultrafiltration to wash the polystyrene sulfonic acid. This washing operation was repeated three times. The water in the obtained solution was removed under reduced pressure to obtain colorless solid polystyrene sulfonic acid. Next, 10 g of the obtained polystyrene sulfonic acid was dissolved in 90 g of ion-exchanged water to obtain a 10% by mass aqueous solution of polystyrene sulfonic acid.

[0157] By gel permeation chromatography (GPC), using pullulan with a known weight average molecular weight as a standard substance, the weight average molecular weight (Mw) of the polystyrene sulfonic acid (PSS) obtained above was measured. As a result, the weight average molecular weight was 180,000. The measurement of the weight average molecular weight was carried out using a high-performance liquid chromatograph Prominence manufactured by Shimadzu Corporation, using a 0.1% aqueous NaNO3 solution as a solvent, a Shodex OHpack SB-806M HQ column, a RID-20A detector, setting the solvent temperature at 40 °C, the flow rate at 0.6 ml / min, making the PSS concentration in the sample 0.1% by mass, injecting 100 μl of the sample filtered through a membrane filter with a pore size of 0.2 μm, and using analysis software Lab Solutions (manufactured by Shimadzu Corporation).

[0158] (Production Example 2) Production of Polystyrene Sulfonic Acid 2 206 g of sodium styrene sulfonate was dissolved in 1000 ml of ion-exchanged water, and while stirring at 80 °C, a solution of 0.38 g of ammonium persulfate oxidant previously dissolved in 10 ml of water was added dropwise over 20 minutes, and this solution was stirred for 12 hours. To the obtained sodium polystyrene sulfonate solution, 1000 ml of sulfuric acid diluted to 10% by mass was added, and approximately 1000 ml of the solvent of the obtained polystyrene sulfonic acid solution was removed by ultrafiltration. Next, 2000 ml of ion-exchanged water was added to the residual liquid, and approximately 2000 ml of the solvent was removed by ultrafiltration to wash the polystyrene sulfonic acid. This washing operation was repeated three times. The water in the obtained solution was removed under reduced pressure to obtain colorless solid polystyrene sulfonic acid. Next, 10 g of the obtained polystyrene sulfonic acid was dissolved in 90 g of ion-exchanged water to obtain a 10% by mass aqueous solution of polystyrene sulfonic acid. The weight-average molecular weight of the polystyrene sulfonic acid (PSS) obtained above, measured using GPC in the same manner as in Production Example 1, was 540,000.

[0159] (Example 1) 3.0 g of 3,4-ethylenedioxythiophene (EDOT), 90 g of the 10% by mass PSS aqueous solution of Production Example 1, and 325 g of ion-exchanged water were mixed at 20°C. The obtained mixed solution was kept at 20°C, and while stirring, 1.2 g of ferric sulfate was added. Next, an oxidizing agent solution (25°C) prepared by dissolving 6.6 g of sodium persulfate in 293.4 g of ion-exchanged water was slowly added over 4 hours, and the reaction solution (25°C) obtained after adding all of the oxidizing agent solution was stirred for 8 hours to react. By the above reaction, a conductive polymer-containing liquid containing a conductive composite (PEDOT-PSS) containing poly(3,4-ethylenedioxythiophene), which is a π-conjugated conductive polymer, and polystyrene sulfonic acid, and water as a dispersion medium was obtained. To this conductive polymer-containing liquid, 39 g of Duolite C255LFH (manufactured by Sumika Chemtex Corporation, cation exchange resin) and 39 g of Duolite A368S (manufactured by Sumika Chemtex Corporation, anion exchange resin) were added, and filtered to remove the ion exchange resin, obtaining 710 g of a conductive polymer-containing liquid (non-volatile component concentration: 1.4% by mass) from which the oxidizing agent and the catalyst had been removed. Next, ion-exchanged water was added to the obtained conductive polymer-containing liquid to adjust the non-volatile component concentration to 1.0% by mass, and it was dispersed using a high-pressure homogenizer.

[0160] A part of the above-mentioned conductive polymer-containing liquid was collected and analyzed by a gas chromatography-mass spectrometer. As a result, unreacted EDOT was below the measurement limit. From this result, it was found that almost all of the EDOT had formed PEDOT. The above gas chromatography measurement was performed using GCMS-QP2010Plus manufactured by Shimadzu Corporation, using helium as the carrier gas, DB-5MS as the column, a secondary electron multiplier tube with a conversion diode as the detector, setting the vaporization temperature to 250 °C, setting the flow rate to 1.2 mL / min, injecting 1 μL of the sample, setting the PEDOT-PSS concentration in the sample to 1.0% by mass, and using the analysis software GCMSsolution.

[0161] A part of the above-mentioned conductive polymer-containing liquid was collected and filtered through a membrane filter with a pore size of 0.2 μm (manufactured by Membrane Solutions Japan, model number: NY-030022) to trap PEDOT-PSS on the membrane, while allowing the single PSS (the one that did not form PEDOT-PSS) contained in the conductive polymer-containing liquid to permeate and be recovered in the filtrate. When the weight average molecular weight of the PSS contained in this filtrate was measured by GPC as described in Production Example 1, it was 96,000.

[0162] Next, 0.1 g of methyl gallate was added to 100 g of the above-mentioned conductive polymer-containing liquid, and after standing under the conditions of 40 °C for 720 hours, simulating the storage environment in a room without air conditioning in summer, the weight average molecular weight of the PSS that did not form PEDOT-PSS was measured by GPC in the same manner as above, and it was 86,000. Therefore, the weight average molecular weight X of the single PSS before the above standing was 96,000, the weight average molecular weight Y of the single PSS after the standing was 86,000, and Y / X = 0.90.

[0163] Subsequently, the conductive polymer-containing liquid after the above standing was applied onto a PET film using a #4 bar coater and dried at 120°C for 1 minute to obtain a conductive film. Table 1 shows the results of measuring the surface resistance value R0 of this conductive film. Furthermore, the conductive film whose surface resistance value R0 was measured was left standing in the atmosphere under the conditions of a temperature of 25°C and a humidity of 50%RH for 30 days, and then the surface resistance value R1 was measured again in the same manner as above. Table 1 shows the results and the increase ratio of the surface resistance value (R1 / R0).

[0164] The surface resistance value of the conductive layer of the conductive film was measured using a resistivity meter (HiResta manufactured by Nitto Seiko Analytic Co., Ltd.) under the condition of an applied voltage of 10V. In the table, "1.0E+05" means "1.0×10 5 ", and the same applies to others.

[0165] (Example 2) A conductive polymer-containing liquid was obtained in the same manner as in Example 1 except that the addition amount of methyl gallate was changed to 0.5 g in Example 1. The weight average molecular weight was measured, a conductive film was prepared, and its surface resistance value was measured.

[0166] (Example 3) A conductive polymer-containing liquid was obtained in the same manner as in Example 1 except that 0.1 g of gallic acid was added instead of 0.1 g of methyl gallate in Example 1. The weight average molecular weight was measured, a conductive film was prepared, and its surface resistance value was measured.

[0167] (Example 4) A conductive polymer-containing liquid was obtained in the same manner as in Example 1 except that 0.5 g of gallic acid was added instead of 0.1 g of methyl gallate in Example 1. The weight average molecular weight was measured, a conductive film was prepared, and its surface resistance value was measured.

[0168] (Example 5) A conductive polymer-containing solution was obtained in the same manner as in Example 1, except that 0.1 g of hydroquinone was added instead of 0.1 g of methyl gallate. The weight-average molecular weight was measured, and a conductive film was prepared and its surface resistance value was measured.

[0169] (Example 6) A conductive polymer-containing solution was obtained in the same manner as in Example 1, except that 0.5 g of hydroquinone was added instead of 0.1 g of methyl gallate. The weight-average molecular weight was measured, and a conductive film was prepared and its surface resistance value was measured.

[0170] (Comparative Example 1) A conductive polymer-containing solution was obtained in the same manner as in Example 1, except that methyl gallate was not added. The weight-average molecular weight was measured, and a conductive film was prepared and its surface resistance value was measured.

[0171] (Example 7) A conductive polymer-containing solution was obtained in the same manner as in Example 1, except that "90 g of a 10% by mass aqueous PSS solution of Production Example 1 and 325 g of ion-exchanged water were mixed at 20°C." was changed to "150 g of a 10% by mass aqueous PSS solution of Production Example 1 and 265 g of ion-exchanged water were mixed at 20°C." As a result, 710 g of a conductive polymer-containing solution (non-volatile component concentration: 1.8% by mass) was obtained. The weight-average molecular weight was measured, and a conductive film was prepared and its surface resistance value was measured. The results are shown in Table 1.

[0172] (Comparative Example 2) A conductive polymer-containing solution was obtained in the same manner as in Example 7, except that methyl gallate was not added. The weight-average molecular weight was measured, and a conductive film was prepared and its surface resistance value was measured.

[0173] (Example 8) A conductive polymer-containing liquid (nonvolatile component concentration: 1.4% by mass, 710 g) was obtained in the same manner as in Example 1, except that "90 g of a 10% by mass aqueous PSS solution of Production Example 1" was changed to "90 g of a 10% by mass aqueous PSS solution of Production Example 2". The weight average molecular weight was measured, a conductive film was prepared, and its surface resistance value was measured. The results are shown in Table 1.

[0174] (Comparative Example 3) A conductive polymer-containing liquid was obtained in the same manner as in Example 8, except that methyl gallate was not added in Example 8. The weight average molecular weight was measured, a conductive film was prepared, and its surface resistance value was measured.

[0175] [Table 1]

[0176] (Example 9) To 100 g of the conductive polymer-containing liquid after standing at 40°C for 720 hours in Example 1, 50 g of isopropanol and 10 g of trioctylamine were added, and the mixture was stirred for 1 hour to react trioctylamine with some of the sulfonic acid groups of the conductive composite. As a result, all of the reaction product precipitated on the upper layer of the reaction solution. This precipitate was filtered to obtain a powder of the reaction product of the conductive composite and trioctylamine. Isopropanol was added to this powder to make a 500 g mixture, which was dispersed using a high-pressure homogenizer to obtain 500 g of a conductive polymer-containing liquid. The results of measuring the nonvolatile component concentration of this liquid are shown in Table 2. Next, the obtained conductive polymer-containing liquid was coated on a PET film using a #8 bar coater and dried at 100°C for 1 minute to obtain a conductive film, and the surface resistance value was measured in the same manner as in Example 1. The results are shown in Table 2.

[0177] (Comparative Example 4) Except for changing 100 g of the conductive polymer-containing liquid of Example 1 to 100 g of the conductive polymer-containing liquid of Comparative Example 1 (nonvolatile component concentration: 1.0 mass%), a conductive polymer-containing liquid using isopropanol as a dispersion medium was obtained in the same manner as in Example 9, and a conductive film was produced. The results are shown in Table 2.

[0178] (Example 10) To 100 g of the conductive polymer-containing liquid of Example 1 after standing at 40 °C for 720 hours, 25 g of an epoxy compound (Epolite M-1230, C12,13 mixed higher alcohol glycidyl ether, manufactured by Kyoeisha Chemical Co., Ltd.) was added, and the mixture was heated and stirred at 60 °C for 4 hours to react the epoxy compound with some of the sulfonic acid groups of the conductive composite. As a result, a reaction product precipitated. This precipitate was filtered to obtain a reaction product of the conductive composite and the epoxy compound. Methyl ethyl ketone was added to this reaction product to make a 300 g mixture, which was dispersed using a high-pressure homogenizer to obtain 300 g of a conductive polymer-containing liquid. The results of measuring the nonvolatile component concentration of this containing liquid are shown in Table 2. Next, the obtained conductive polymer-containing liquid was applied onto a PET film using a #8 bar coater and dried at 100 °C for 1 minute to obtain a conductive film, and the surface resistance value thereof was measured. The results are shown in Table 2.

[0179] (Comparative Example 5) Except for changing 100 g of the conductive polymer-containing liquid of Example 1 to 100 g of the conductive polymer-containing liquid of Comparative Example 1 (nonvolatile component concentration: 1.0 mass%), a conductive polymer-containing liquid using methyl ethyl ketone as a dispersion medium was obtained in the same manner as in Example 10, and a conductive film was produced. The results are shown in Table 2.

[0180] (Example 11) To 100 g of the conductive polymer-containing liquid after standing at 40°C for 720 hours in Example 1, 25 g of an epoxy compound (manufactured by Kyoeisha Chemical Co., Ltd., Epolite M-1230, C12,13 mixed higher alcohol glycidyl ether) was added, and the mixture was heated and stirred at 60°C for 4 hours. Next, 50 g of isopropanol and 10 g of trioctylamine were added and stirred for 1 hour, whereby the epoxy compound and trioctylamine reacted with some of the sulfonic acid groups of the conductive composite. As a result, a reaction product precipitated. This precipitate was filtered to obtain a reaction product of the conductive composite, the epoxy compound, and trioctylamine. Ethyl acetate was added to this reaction product to make a 800 g mixture, which was dispersed using a high-pressure homogenizer to obtain 800 g of a conductive polymer-containing liquid. The results of measuring the non-volatile component concentration of this liquid are shown in Table 2. Next, the obtained conductive polymer-containing liquid was applied onto a PET film using a #8 bar coater and dried at 100°C for 1 minute to obtain a conductive film, and the surface resistance value thereof was measured. The results are shown in Table 2.

[0181] (Comparative Example 6) A conductive polymer-containing liquid using ethyl acetate as a dispersion medium was obtained, a conductive film was obtained, and the surface resistance value thereof was measured in the same manner as in Example 11, except that 100 g of the conductive polymer-containing liquid in Example 1 was changed to 100 g of the conductive polymer-containing liquid in Comparative Example 1 (non-volatile component concentration: 1.0 mass%). The results are shown in Table 2.

[0182]

Table 2

[0183] <Results> From the results of Comparative Examples 1 to 3, it was found that after standing at 40°C for 720 hours (storage conditions assuming a room without air conditioning in summer), the molecular weight of PSS (single PSS) that did not form PEDOT-PSS contained in the conductive polymer-containing liquid was reduced to a low molecular weight, and the ratio (Y / X) of the weight average molecular weight was less than 0.88. The atmospheric exposure resistance of the conductive layer formed by coating the conductive polymer-containing liquid containing such low molecular weight single PSS was inferior to that of the examples. On the other hand, in the conductive polymer-containing liquids of Examples 1 to 8, since a molecular weight maintaining agent is contained, even after the above-mentioned standing, the individual PSS contained in the conductive polymer-containing liquid is not degraded into low molecular weight, and the ratio (Y / X) of the weight average molecular weight was found to be 0.88 or more. The conductive layer formed by coating the conductive polymer-containing liquid in which the degradation of the individual PSS into low molecular weight was thus suppressed had better atmospheric exposure resistance than Comparative Examples 1 to 3. Note that Examples 1 to 8 are reference examples.

[0184] In the conductive polymer-containing liquids produced in Examples 9 to 11, although they substantially do not contain a molecular weight maintaining agent, since the conductive polymer-containing liquid of Example 1 used as a raw material contained a molecular weight maintaining agent, the individual PSS was not degraded into low molecular weight. For this reason, the conductive layer formed by coating the conductive polymer-containing liquid produced in Examples 9 to 11 had better atmospheric exposure resistance than Comparative Examples 4 to 6. The individual PSS contained in the conductive polymer-containing liquid of Comparative Example 1 used for producing the conductive polymer-containing liquids of Comparative Examples 4 to 6 was degraded into low molecular weight after the above-mentioned standing. For this reason, the conductive layer formed by coating the conductive polymer-containing liquid produced in Comparative Examples 4 to 6 was inferior in atmospheric exposure resistance to Examples 9 to 11.

[0185] <Action mechanism> In the conductive polymer-containing liquid of the comparative example, the individual polyanion was degraded into low molecular weight during the standing period (storage), the ratio of the individual polyanion present on the surface of the coating film decreased, and the ratio of the conductive complex present on the surface relatively increased. As a result, it is presumed that the conductive complex on the surface of the conductive layer is likely to come into contact with the atmosphere, and the atmospheric exposure resistance of the conductive layer is lowered. On the other hand, in the conductive polymer-containing liquid of the example, since the individual polyanion can be maintained at a high molecular weight after storage, the individual polyanion tends to gather on the surface of the coating film (is easily repelled from the deep part and easily accumulates on the surface). The individual polyanion on the surface of the coating film reduces the contact between the atmosphere and the conductive complex and functions as a protective agent for the conductive complex, so it is presumed that the conductive layer has excellent atmospheric exposure resistance.

Claims

1. By adding an epoxy compound to the following conductive polymer-containing liquid (Z) containing a molecular weight maintaining agent, a reaction product containing the following conductive composite is precipitated, recovering the precipitated reaction product, adding a dispersion medium containing an organic solvent, and obtaining a conductive polymer-containing liquid in which the reaction product is dispersed in the dispersion medium, A method for producing a conductive polymer-containing liquid. <Conductive polymer-containing liquid (Z)> The conductive polymer-containing liquid (Z) contains a conductive composite containing a π-conjugated conductive polymer and a polyanion, the polyanion not forming the conductive composite, and the polyanion not forming the conductive composite. It contains a molecular weight maintaining agent that suppresses the reduction of the molecular weight of the polyanion and a dispersion medium. When the initial weight average molecular weight of the polyanion not forming the conductive composite is X, and the weight average molecular weight of the polyanion not forming the conductive composite after the conductive polymer-containing liquid (Z) is allowed to stand at 40 ° C for 720 hours is Y, The molecular weight ratio represented by Y / X is 0.88 or more. The molecular weight maintaining agent contains an aromatic compound, and the aromatic compound is a compound in which two or more hydrogen atoms of a benzene ring are substituted with hydroxyl groups. The benzene ring may have one or more carboxyl groups, and the carboxyl group may be esterified. The benzene ring has no substituents other than the hydroxyl group and the carboxyl group.

2. By adding an amine compound or a quaternary ammonium compound to the following conductive polymer-containing liquid (Z) containing a molecular weight maintaining agent, a reaction product containing the following conductive composite is precipitated, recovering the precipitated reaction product, adding a dispersion medium containing an organic solvent, and obtaining a conductive polymer-containing liquid in which the reaction product is dispersed in the dispersion medium, A method for producing a conductive polymer-containing liquid. <Conductive polymer-containing liquid (Z)> The conductive polymer-containing liquid (Z) contains a conductive complex comprising a π-conjugated conductive polymer and a polyanion, the polyanion not forming the conductive complex, a molecular weight maintaining agent for suppressing the low molecular weight of the polyanion not forming the conductive complex, and a dispersion medium. When the initial weight average molecular weight of the polyanion not forming the conductive complex is X, and the weight average molecular weight of the polyanion not forming the conductive complex after allowing the conductive polymer-containing liquid (Z) to stand at 40 ° C for 720 hours is Y, the molecular weight ratio represented by Y / X is 0.88 or more. The molecular weight maintaining agent contains an aromatic compound, the aromatic compound is a compound in which two or more hydrogen atoms of a benzene ring are substituted with hydroxyl groups, the benzene ring may have one or more carboxyl groups, the carboxyl group may be esterified, and the benzene ring has no substituents other than the hydroxyl group and the carboxyl group.

3. By adding an epoxy compound and an amine compound or a quaternary ammonium compound to the following conductive polymer-containing liquid (Z) containing a molecular weight maintaining agent, a reaction product containing the following conductive complex is precipitated. Recovering the precipitated reaction product and adding a dispersion medium containing an organic solvent to obtain a conductive polymer-containing liquid in which the reaction product is dispersed in the dispersion medium. A method for producing a conductive polymer-containing liquid. <Conductive Polymer-Containing Liquid (Z)> The conductive polymer-containing liquid (Z) contains a conductive complex comprising a π-conjugated conductive polymer and a polyanion, the polyanion not forming the conductive complex, a molecular weight maintaining agent for suppressing the low molecular weight of the polyanion not forming the conductive complex, and a dispersion medium. When the initial weight average molecular weight of the polyanion not forming the conductive complex is X, and the weight average molecular weight of the polyanion not forming the conductive complex after allowing the conductive polymer-containing liquid (Z) to stand at 40 ° C for 720 hours is Y, the molecular weight ratio represented by Y / X is 0.88 or more. The molecular weight maintaining agent contains an aromatic compound, and the aromatic compound is a compound in which two or more hydrogen atoms of a benzene ring are substituted with hydroxyl groups. The benzene ring may have one or more carboxyl groups, and the carboxyl group may be esterified. The benzene ring has no substituents other than the hydroxyl group and the carboxyl group.

4. The method for producing a conductive polymer-containing liquid according to any one of claims 1 to 3, wherein the π-conjugated system conductive polymer is poly(3,4-ethylenedioxythiophene).

5. The method for producing a conductive polymer-containing liquid according to any one of claims 1 to 4, wherein the polyanion is polystyrene sulfonic acid.

6. A method for producing a conductive laminate, comprising: a step of obtaining a conductive polymer-containing liquid by the production method according to any one of claims 1 to 5; and a step of coating the conductive polymer-containing liquid on at least a part of a surface of a substrate.

7. The method for producing a conductive laminate according to claim 6, wherein the substrate is a film substrate.

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