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

Abstract

To provide a conductive polymer-containing liquid and a method for producing the same, in which dispersibility of a conductive complex coexisting with isopropanol is improved.SOLUTION: A conductive polymer-containing liquid comprising a conductive complex containing a π-conjugated conductive polymer and a polyanion, and a dispersion medium, wherein the dispersion medium contains water and isopropanol, and wherein a content of iron ions relative to a total mass of the conductive polymer-containing liquid is 0.200 ppm or less. Preferably, a content of the isopropanol relative to a total mass of the dispersion medium is 90 mass% 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 and a method for producing the same, as well as a conductive laminate and a method for producing the same. [Background technology]

[0002] A conductive polymer dispersion containing a conductive complex in which a π-conjugated conductive polymer is doped with a polyanion may be used as a paint or a component thereof for forming a conductive layer. For example, the π-conjugated conductive polymer poly(3,4-ethylenedioxythiophene) is difficult to disperse in water, but doping it with polystyrene sulfonic acid to form PEDOT-PSS increases its dispersibility in water. Patent Document 1 discloses a technique for improving the hydrophilicity of a conductive complex and its reactivity with epoxy compounds by dispersing the conductive complex in water and leaving it for 180 days or more. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-31013 Summary of the Invention [Problem to be solved by the invention]

[0004] In the method of Patent Document 1, an epoxy compound is reacted with a conductive composite, and then the composite is dissolved in an organic solvent to form a coating material, thereby increasing the wettability of the composite with respect to a hydrophobic film substrate. On the other hand, when the conductive composite is not hydrophobized by reaction with an epoxy compound, attempts have been made to improve the wettability of the conductive polymer dispersion by adding methanol or ethanol to the conductive polymer dispersion. However, satisfactory wettability is not always obtained. Furthermore, when isopropanol is added to the conductive polymer dispersion in an attempt to further improve wettability, the dispersibility of the conductive composite deteriorates, and it may precipitate immediately, making it impossible to coat.

[0005] The present inventors have discovered that significantly reducing the content of iron ions in a conductive polymer dispersion improves the dispersibility of a conductive composite in isopropanol, resulting in a coatable conductive polymer-containing liquid, and have completed the present invention.

[0006] The present invention provides a conductive polymer-containing liquid in which the dispersibility of a conductive composite coexisting with isopropanol is improved, a method for producing the same, and a conductive laminate formed using the conductive polymer-containing liquid and a method for producing the same. [Means for solving the problem]

[0007] [1] A conductive polymer-containing liquid containing a conductive complex including a π-conjugated conductive polymer and a polyanion, and a dispersion medium, wherein the dispersion medium contains water and isopropanol, and the content of iron ions relative to the total mass of the conductive polymer-containing liquid is 0.200 ppm or less. [2] The conductive polymer-containing liquid according to [1], wherein the content of the isopropanol relative to the total mass of the dispersion medium is 90 mass % or more. [3] The conductive polymer-containing liquid according to [1] or [2], wherein the content of the water relative to the total mass of the dispersion medium is 1% by mass or more and 10% by mass or less. [4] The conductive polymer-containing liquid according to any one of [1] to [3], wherein the total content of the isopropanol and the water relative to the total mass of the dispersion medium is 90 mass % or more. [5] The conductive polymer-containing liquid according to any one of [1] to [4], further containing a binder component. [6] The conductive polymer-containing liquid according to any one of [1] to [5], wherein the π-conjugated conductive polymer is poly(3,4-ethylenedioxythiophene) or the polyanion is polystyrene sulfonic acid. [7] A method for producing a conductive polymer-containing liquid, comprising the steps of: obtaining a conductive polymer dispersion (A) containing a conductive composite comprising the π-conjugated conductive polymer and the polyanion, the aqueous dispersion medium, and the iron ions by polymerizing the monomer in a reaction liquid containing a polyanion, an aqueous dispersion medium, a monomer that forms the π-conjugated conductive polymer, and iron ions; adding a cation exchange resin to the conductive polymer dispersion (A) to adsorb at least a portion of the iron ions, and then removing the cation exchange resin to obtain a conductive polymer dispersion (B); and adding at least isopropanol to the conductive polymer dispersion (B) to obtain a conductive polymer-containing liquid, wherein the content of the iron ions relative to the total mass of the conductive polymer dispersion (B) is 5 ppm or less, and the content of the iron ions relative to the total mass of the conductive polymer-containing liquid is 0.200 ppm. [8] A conductive laminate comprising a film substrate and a conductive layer formed on one surface of the film substrate, the conductive layer being a cured layer of the conductive polymer-containing liquid according to any one of [1] to [6]. [9] The conductive laminate according to [8], further comprising a pressure-sensitive adhesive layer on the other surface of the film substrate.

[10] A method for producing a conductive laminate, comprising applying the conductive polymer-containing liquid according to any one of [1] to [6] to at least a partial surface of a substrate. [Effects of the Invention]

[0008] According to the method for producing a conductive polymer-containing liquid of the present invention, a conductive polymer-containing liquid having excellent dispersibility of the conductive composite can be easily produced. The conductive polymer-containing liquid of the present invention has excellent dispersibility and also has excellent wettability to hydrophobic substrates such as plastics. According to the method for producing a conductive laminate of the present invention, the conductive polymer-containing liquid used has excellent dispersibility and excellent wettability to the substrate, so that the conductive laminate can be easily produced. The conductive laminate of the present invention has a conductive layer with good conductivity.

[0009] This invention is believed to contribute to SDG Goal 12, "Responsible Consumption and Production." DETAILED DESCRIPTION OF THE INVENTION

[0010] In this specification and claims, the lower and upper limits of numerical ranges indicated with "to" are included in the numerical range.

[0011] ≪Conductive polymer-containing liquid≫ A first aspect of the present invention is a conductive polymer-containing liquid containing a conductive composite including a π-conjugated conductive polymer and a polyanion, and a dispersion medium. The dispersion medium contains water and isopropanol. The conductive polymer-containing liquid has an iron ion content of 0.200 ppm or less relative to the total mass of the conductive polymer-containing liquid. In the conductive polymer-containing liquid of this embodiment, the conductive complex may be in a dispersed state or a dissolved state, and no distinction is made between the two unless otherwise specified.

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

[0013] Polythiophene-based conductive polymers include polythiophene, poly(3-methylthiophene), poly(3-ethylthiophene), poly(3-propylthiophene), poly(3-butylthiophene), poly(3-hexylthiophene), poly(3-heptylthiophene), poly(3-octylthiophene), poly(3-decylthiophene), poly(3-dodecylthiophene), poly(3-octadecylthiophene), poly(3-bromothiophene), poly(3-chlorothiophene), and poly(3-iodothiophene). thiophene), poly(3-cyanothiophene), poly(3-phenylthiophene), poly(3,4-dimethylthiophene), poly(3,4-dibutylthiophene), poly(3-hydroxythiophene), poly(3-methoxythiophene), poly(3-ethoxythiophene), poly(3-butoxythiophene), poly(3-hexyloxythiophene), poly(3-heptyloxythiophene), poly(3-octyloxythiophene), poly(3-decyloxythiophene), poly(3-dodecyloxythiophene) oxythiophene), poly(3-octadecyloxythiophene), poly(3,4-dihydroxythiophene), poly(3,4-dimethoxythiophene), poly(3,4-diethoxythiophene), poly(3,4-dipropoxythiophene), poly(3,4-dibutoxythiophene), poly(3,4-dihexyloxythiophene), poly(3,4-diheptyloxythiophene), poly(3,4-dioctyloxythiophene), poly(3,4-didecyloxythiophene), poly(3,4-di dodecyloxythiophene), poly(3,4-ethylenedioxythiophene), poly(3,4-propylenedioxythiophene), poly(3,4-butylenedioxythiophene), poly(3-methyl-4-methoxythiophene), poly(3-methyl-4-ethoxythiophene), poly(3-carboxythiophene), poly(3-methyl-4-carboxythiophene), poly(3-methyl-4-carboxyethylthiophene), and poly(3-methyl-4-carboxybutylthiophene). Examples of polypyrrole-based conductive polymers include polypyrrole, poly(N-methylpyrrole), poly(3-methylpyrrole), poly(3-ethylpyrrole), poly(3-n-propylpyrrole), poly(3-butylpyrrole), poly(3-octylpyrrole), poly(3-decylpyrrole), poly(3-dodecylpyrrole), poly(3,4-dimethylpyrrole), poly(3,4-dibutylpyrrole), poly(3-carboxypyrrole), poly(3-methyl-4-carboxypyrrole), poly(3-methyl-4-carboxyethylpyrrole), poly(3-methyl-4-carboxybutylpyrrole), poly(3-hydroxypyrrole), poly(3-methoxypyrrole), poly(3-ethoxypyrrole), poly(3-butoxypyrrole), poly(3-hexyloxypyrrole), and poly(3-methyl-4-hexyloxypyrrole). Examples of polyaniline-based conductive polymers include polyaniline, poly(2-methylaniline), poly(3-isobutylaniline), poly(2-anilinesulfonic acid), and poly(3-anilinesulfonic acid). Among the above-mentioned π-conjugated conductive polymers, poly(3,4-ethylenedioxythiophene) is particularly preferable in terms of conductivity, transparency, and heat resistance. The conductive composite may contain one type of π-conjugated conductive polymer, or two or more types of polymers.

[0014] <Polyanion> A polyanion is a polymer having two or more monomer units with an anionic group in the molecule. The anionic group of this polyanion functions as a dopant for a π-conjugated conductive polymer, improving 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 polymers having sulfo groups, such as polystyrene sulfonic acid, polyvinyl sulfonic acid, polyallyl sulfonic acid, polyacrylic acid esters having sulfo groups, polymethacrylic acid esters having sulfo groups (for example, poly(4-sulfobutyl methacrylate, polysulfoethyl methacrylate, polymethacryloyloxybenzenesulfonic acid), poly(2-acrylamido-2-methylpropanesulfonic acid), and polyisoprene sulfonic acid; and polymers having carboxy groups, such as polyvinyl carboxylic acid, polystyrene carboxylic acid, polyallyl carboxylic acid, polyacrylic acid, polymethacrylic acid, poly(2-acrylamido-2-methylpropanecarboxylic acid), and polyisoprene carboxylic acid. These may be homopolymers or copolymers of two or more types. Among these polyanions, polymers having sulfo groups are preferred, and polystyrene sulfonic acid is more preferred, since they can further increase the conductivity. The conductive complex may be made up of one type of polyanion or two or more types of polyanions. The mass-average molecular weight of the polyanion is preferably 20,000 to 1,000,000, more preferably 100,000 to 500,000. The mass-average molecular weight is the average molecular weight based on mass measured using gel permeation chromatography and calculated in terms of polystyrene.

[0015] A conductive composite is formed by doping a π-conjugated conductive polymer with a polyanion. However, in the polyanion, some anionic groups do not dope into the π-conjugated conductive polymer, leaving excess anionic groups that are not involved in the doping. Because these excess anionic groups are hydrophilic, the conductive composite has high water dispersibility but low organic solvent dispersibility unless the iron ion content is adjusted as described below. When the number of all anionic groups in the polyanion is taken as 100 mol %, the excess anionic 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] In the conductive polymer-containing liquid of this embodiment, the content of the polyanion is preferably in the range of 1 part by mass to 1,000 parts by mass, more preferably 10 parts by mass to 700 parts by mass, and even more preferably 100 parts by mass to 500 parts by mass, per 100 parts by mass of the π-conjugated conductive polymer. If the content of the polyanion is equal to or greater than the lower limit, the doping effect on the π-conjugated conductive polymer tends to be stronger, resulting in higher conductivity. On the other hand, if the content of the polyanion is equal to or less than the upper limit, the amount of anionic groups not involved in doping is appropriately suppressed, making it easier to disperse the conductive composite at a predetermined iron ion content in a dispersion medium containing isopropanol.

[0017] The content of the π-conjugated conductive polymer and polyanion relative to the total mass of the conductive polymer-containing liquid of this embodiment is preferably 0.001% by mass or more and 1.0% by mass or less, more preferably 0.01% by mass or more and 0.5% by mass or less, even more preferably 0.02% by mass or more and 0.1% by mass or less, and particularly preferably 0.03% by mass or more and 0.05% by mass or less. When the content is at least as large as the lower limit of the above range, the conductivity of the conductive layer formed by applying the conductive polymer-containing liquid can be further improved. When the content is equal to or less than the upper limit of the above range, the dispersibility of the conductive complex in the conductive polymer-containing liquid is improved, and a uniform conductive layer can be formed.

[0018] <Dispersion medium> The dispersion medium contained in the conductive polymer-containing liquid of this embodiment is a liquid agent that disperses or dissolves the conductive composite. In this specification, the term "dispersion" may be used without distinguishing between dispersion and dissolution, and the term "dispersion medium" may be used without distinguishing between a dispersion medium and a solvent. Therefore, the dispersion medium may also be referred to as a solvent.

[0019] The dispersion medium in this embodiment comprises water and isopropanol. The content of isopropanol relative to the total mass of the dispersion medium in this embodiment can be, for example, 90% by mass or more, more preferably 92% by mass or more, even more preferably 94% by mass or more, and even more preferably 96% by mass or more. Even at such a high content, the dispersibility of the conductive composite can be sufficiently improved. The content of water relative to the total mass of the dispersion medium in this embodiment is preferably from 1 to 10% by mass, more preferably from 1.5 to 5% by mass, and even more preferably from 2 to 4% by mass. When the content is at least the lower limit of the above range, the dispersibility of the conductive composite is further improved. When the content is equal to or less than the upper limit of the above range, the wettability of the conductive polymer-containing liquid to the substrate is further improved. The total content of isopropanol and water relative to the total mass of the dispersion medium in this embodiment is preferably 90 mass% or more, more preferably 95 mass% or more, and even more preferably 98 mass% or more. Within this preferred range, the dispersibility of the conductive composite is further improved, and the wettability of the conductive polymer-containing liquid to the substrate is further improved.

[0020] The dispersion medium of this embodiment may contain a solvent other than water and isopropanol (another solvent). The other solvent is preferably a water-soluble organic solvent, which dissolves 1 g or more in 100 g of water at 20°C.

[0021] Examples of the water-soluble organic solvent include alcohol-based solvents, ether-based solvents, ketone-based solvents, nitrogen atom-containing solvents, and ester-based solvents. Examples of alcohol-based solvents (alcohols) include ethanol, 1-propanol, 2-methyl-2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol, allyl alcohol, ethylene glycol, propylene glycol, propylene glycol monomethyl ether, and ethylene glycol monomethyl ether. Examples of the ether solvent include diethyl ether, dimethyl ether, propylene glycol dialkyl ether, and diethylene glycol diethyl ether. Examples of ketone 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, and diacetone alcohol. Examples of nitrogen atom-containing solvents include N-methylpyrrolidone, dimethylacetamide, and dimethylformamide. The water-soluble organic solvents may be used alone or in combination of two or more.

[0022] (iron ion content) The content of iron ions relative to the total mass of the conductive polymer-containing liquid of this embodiment is 0.200 ppm or less, preferably 0.150 ppm or less, more preferably 0.120 ppm or less, even more preferably 0.090 ppm or less, particularly preferably 0.050 ppm or less, and may be 0.0030 ppm or less, 0.010 ppm or less, or even 0 ppm. Within the above preferred range, the dispersibility of the conductive composite is further improved. The content of iron ions contained in the conductive polymer-containing liquid of this embodiment is determined by ICP emission spectrometry. 2+ and Fe 3+ The total amount of both is taken as the iron ion content without distinction.

[0023] <Binder components> The conductive polymer-containing liquid of this embodiment may contain a binder component. The binder component is a resin other than the π-conjugated conductive polymer and the polyanion or a precursor thereof, and is a thermoplastic resin or a curable monomer or oligomer that cures during the formation of the conductive layer. The thermoplastic resin becomes the binder resin as it is, and the curable monomer or oligomer becomes the resin formed by curing. Only one binder component may be included, or two or more binder components may be included.

[0024] Specific examples of binder resins derived from binder components include acrylic resins (acrylic compounds), polyester resins, polyurethane resins, polyimide resins, polyether resins, melamine resins, and silicones. The binder resin contained in the conductive polymer-containing liquid of this embodiment is preferably a water-dispersible resin, more preferably a water-dispersible emulsion resin. The water-dispersible resin is an emulsion resin or a water-soluble resin.

[0025] Specific examples of water-dispersible emulsion resins include acrylic resins (acrylic compounds), polyester resins, polyurethane resins, polyimide resins, melamine resins, and the like, which are emulsified with an emulsifier.

[0026] Since the strength of a coating film formed by applying the conductive polymer-containing liquid of this embodiment to a substrate is increased, the binder resin preferably contains a resin having an epoxy group, more preferably contains an acrylic resin having an epoxy group, and further preferably contains an emulsion of an acrylic resin having an epoxy group.

[0027] The binder resin preferably contains a polyester resin, more preferably a polyester resin emulsion, because the strength of the coating film formed by applying the conductive polymer-containing liquid of this embodiment to a substrate is increased. In particular, when applying the conductive polymer-containing liquid to a polyester film substrate, the binder resin preferably contains a polyester resin or an emulsion thereof, because the adhesion of the coating film to the substrate is increased. The combined use of the acrylic resin and polyester resin is preferred because it further increases the strength and adhesion of the coating film.

[0028] Specific examples of the water-soluble resin include acrylic resins (acrylic compounds), polyester resins, polyurethane resins, polyimide resins, and melamine resins, which have an acid group such as a carboxy group or a sulfo group or a salt thereof. Here, the water-soluble resin is preferably one that dissolves in 100 g of distilled water at 25° C. in an amount of 1 g or more, preferably 5 g or more, and more preferably 10 g or more. The acid group such as a carboxy group or a sulfo group contained in the water-dispersible resin may form a salt with a cation such as a sodium ion or a potassium ion.

[0029] The binder component may be a curable monomer or oligomer, which may be a thermosetting monomer or oligomer, or a photocurable monomer or oligomer. Here, the oligomer refers to a polymer having a mass average molecular weight of less than 10,000. Note that a polymer having a mass average molecular weight of more than 10,000 does not have curability. Examples of the curable monomer include an acrylic monomer (acrylic compound), an epoxy monomer, and an organosiloxane. Examples of the curable oligomer include an acrylic oligomer (acrylic compound), an epoxy oligomer, and a silicone oligomer (curable silicone). When an acrylic monomer or acrylic oligomer is used as the binder component, it can be easily cured by heating or light irradiation. When an organosiloxane or silicone oligomer is used as the binder component, it can impart releasability (non-stickiness) to the conductive layer.

[0030] When a curable monomer or oligomer is contained, it is preferable to further contain a curing catalyst. For example, when a thermosetting monomer or oligomer is contained, it is preferable to contain a thermal polymerization initiator that generates radicals by heating, and when a photocurable monomer or oligomer is contained, it is preferable to contain a photopolymerization initiator that generates radicals by light irradiation. Furthermore, when an organosiloxane or silicone oligomer is contained, it is preferable to contain a platinum catalyst for curing.

[0031] The content ratio of the binder component in the conductive polymer-containing liquid of this embodiment is preferably 100 parts by mass or more and 20,000 parts by mass or less, more preferably 500 parts by mass or more and 10,000 parts by mass or less, and even more preferably 1,000 parts by mass or more and 5,000 parts by mass or less, relative to 100 parts by mass of the conductive composite. When the content is equal to or greater than the lower limit of the above range, the film-forming properties and film strength can be improved when the conductive polymer-containing liquid of this embodiment is applied to a substrate. When the content is equal to or less than the upper limit of the above range, it is possible to suppress a decrease in conductivity due to a decrease in the content ratio of the conductive composite.

[0032] (Other additives) The conductive polymer-containing liquid of this embodiment may contain other known additives. Examples of additives that can be used include surfactants, inorganic conductive agents, antifoaming agents, coupling agents, antioxidants, and ultraviolet absorbers. The surfactant may be a nonionic, anionic, or cationic surfactant, with the nonionic surfactant being preferred from the standpoint of storage stability. A polymer surfactant such as polyvinylpyrrolidone may also be added. Examples of inorganic conductive agents include metal ions, conductive carbon, etc. Metal ions can be generated by dissolving a metal salt in water. Examples of the antifoaming agent include silicone resin, polydimethylsiloxane, and silicone oil. The coupling agent may be a silane coupling agent having a vinyl group or an amino group. Examples of the ultraviolet absorber include benzotriazole-based ultraviolet absorbers, benzophenone-based ultraviolet absorbers, salicylate-based ultraviolet absorbers, cyanoacrylate-based ultraviolet absorbers, oxanilide-based ultraviolet absorbers, hindered amine-based ultraviolet absorbers, and benzoate-based ultraviolet absorbers. When the above-mentioned additives are contained, the content ratio thereof is determined appropriately depending on the type of additive, but can be, for example, in the range of 0.001 parts by mass or more and 5 parts by mass or less per 100 parts by mass of the conductive composite.

[0033] <Method for producing conductive polymer-containing liquid> The second aspect of the present invention includes the following first to third steps: The conductive polymer-containing liquid of the first aspect can be obtained by the production method of this aspect. The first step is a step of obtaining a conductive polymer dispersion (A) containing a conductive composite containing the π-conjugated conductive polymer and the polyanion, the aqueous dispersion medium, and the iron ions by polymerizing the monomer in a reaction solution containing the polyanion, an aqueous dispersion medium, a monomer that forms a π-conjugated conductive polymer, and iron ions. The second step is a step of adding a cation exchange resin to the conductive polymer dispersion (A) to adsorb at least a portion of the iron ions, and then removing the cation exchange resin to obtain a conductive polymer dispersion (B). The third step is a step of adding at least isopropanol to the conductive polymer dispersion (B) to obtain a conductive polymer-containing liquid. The content by mass of the iron ions relative to the total mass of the conductive polymer dispersion (B) obtained in the second step is preferably 5 ppm or less. The content of the iron ions relative to the total mass of the conductive polymer-containing liquid obtained in the third step is preferably 0.200 ppm or less, and more preferably the preferred content described in the first embodiment.

[0034] (first step) The polyanion used in the first step is the same as the polyanion of the first embodiment, and therefore a duplicated description will be omitted here. The monomer used in the first step can be a known monomer that forms the above-mentioned π-conjugated conductive polymer.

[0035] The aqueous dispersion medium constituting the reaction solution is a solvent that dissolves the polyanion and the monomer, and contains at least water and may further contain a water-soluble organic solvent. Specific examples of the water-soluble organic solvent are the same as those described above. The water content relative to the total mass of the aqueous dispersion medium is preferably 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. Within the above preferred range, the polymerization reaction of the monomers can proceed stably.

[0036] The iron ions contained in the reaction solution can function as a catalyst for the polymerization reaction of the monomer. Therefore, it is preferable that the reaction solution contains a catalyst containing iron ions. Specific examples of the catalyst include ferric chloride, ferric sulfate, and ferric nitrate. Among these, ferric sulfate is preferred because it allows stable polymerization of the monomer at room temperature. The content of the catalyst is preferably 0.001% by mass to 2.0% by mass, more preferably 0.01% by mass to 1.0% by mass, and even more preferably 0.1% by mass to 0.5% by mass, based on the total mass of the reaction liquid. Within the above preferred range, the polymerization reaction can proceed stably.

[0037] The reaction solution preferably contains an oxidizing agent 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. The oxidizing agent is preferably dissolved in ion-exchanged water in advance as an oxidizing agent solution, and is then slowly added to the reaction solution. The concentration of the oxidizing agent solution is preferably 0.5% by mass or more and 2.0% by mass or less.

[0038] The temperature of the reaction liquid obtained after the addition of the oxidizing agent solution is preferably maintained at 5 to 30°C during the polymerization reaction. The reaction time required for the reaction in the reaction solution to be completed is approximately 4 to 12 hours, and preferably 6 to 10 hours. The completion of the polymerization reaction can be determined by confirming that all of the monomers have been consumed by gas chromatography.

[0039] (Second process) The conductive polymer dispersion (A) obtained in the first step contains iron ions. Examples of methods for removing at least a portion of the iron ions in this step include contacting the conductive polymer dispersion (A) with an ion exchange resin to adsorb the iron ions onto the ion exchange resin, and ultrafiltrating the conductive polymer dispersion (A) to replace the aqueous dispersion medium and remove the iron ions. Among these, the method using an ion exchange resin is preferred because it is simple. As the ion exchange resin, it is preferable to use at least a cation exchange resin out of a cation exchange resin and an anion exchange resin. The anion exchange resin can adsorb the counter anion of the iron ions.

[0040] In this step, a conductive polymer dispersion liquid (B) from which at least a portion of the iron ions have been removed is obtained. The content of iron ions relative to the total mass of the conductive polymer dispersion liquid (B) is preferably 5 ppm or less, more preferably 4 ppm or less, even more preferably 3 ppm or less, particularly preferably 2 ppm or less, and most preferably 1 ppm or less. When the content is within the above-mentioned preferred range, it becomes easier to adjust the iron ion content in the conductive polymer-containing liquid obtained in the later step to a desired range.

[0041] (Third step) The conductive polymer-containing liquid of the first embodiment can be obtained by adding at least isopropanol to the conductive polymer dispersion liquid (B) obtained in the second step. The amount and ratio of isopropanol to be added are preferably the same as those described in the first embodiment. Other solvents may also be added.

[0042] The obtained conductive polymer-containing liquid is preferably stirred to disperse the conductive composite. The stirring method is not particularly limited, and may be a low shear stirring method such as a stirrer, or a high shear stirring method such as a high-pressure homogenizer. However, from the viewpoint of improving dispersibility, it is preferable to use a high-pressure homogenizer.

[0043] (Optional ingredient addition) A binder component and other additives may be further added to the obtained conductive polymer-containing liquid.

[0044] <Conductive laminate> A third aspect of the present invention is a conductive laminate comprising a substrate and a conductive layer formed on at least a portion of the surface of the substrate, the conductive layer being a cured layer of the conductive polymer-containing liquid of the first aspect.

[0045] [Conductive layer] The conductive layer may be formed on the entire surface of the substrate, or on a part of the surface. When the substrate is a film substrate, the conductive laminate becomes a conductive film. In the conductive film, it is preferable that a conductive layer of substantially uniform thickness is formed on substantially the entire one or other surface of the film substrate. When the conductive layer is formed on only a portion of the surface of the substrate, for example, the conductive layer may be a fine conductive pattern such as a circuit or electrode, or the conductive layer may be provided on the same surface and the area without the conductive layer may be roughly divided.

[0046] The average thickness of the conductive layer is, for example, preferably 10 nm to 100 μm, more preferably 20 nm to 50 μm, and even more preferably 30 nm to 30 μm. When the average thickness of the conductive layer is equal to or greater than the lower limit, high conductivity can be exhibited, and when the average thickness is equal to or less than the upper limit, the adhesion of the conductive layer to the substrate is further improved. The average thickness of the conductive layer is determined by measuring the thickness at 10 randomly selected locations and averaging the measured values.

[0047] [Adhesive layer] When a conductive layer is formed on one surface of the film substrate, a pressure-sensitive adhesive layer may be provided on the other surface of the film substrate. In other words, the pressure-sensitive adhesive layer is an optional layer that may or may not be present. The average thickness of the pressure-sensitive adhesive layer is, for example, preferably 1 nm or more and 1000 μm or less, more preferably 5 nm or more and 500 μm or less, and even more preferably 10 nm or more and 100 μm or less. When the content is at least the lower limit of the above range, sufficient adhesiveness is obtained, and when the content is at most the upper limit of the above range, the adhesiveness of the adhesive layer to the substrate is further improved. The average thickness of the pressure-sensitive adhesive layer is determined by measuring the thickness at 10 randomly selected locations and averaging the measured values.

[0048] The degree of adhesiveness of the adhesive is not particularly limited, and may be adhesive enough to be easily peeled off by hand after application, or may be adhesive enough to be difficult to peel off after application. Adhesion that is difficult to peel off can be rephrased as adhesiveness. In other words, the adhesiveness may be such that it can adhere semi-permanently.

[0049] (acrylic adhesive) As the adhesive, known adhesives can be used, for example, acrylic adhesives. The acrylic adhesive can bond and integrate surfaces of the same or different solids. The acrylic adhesive contains an acrylic resin (acrylic polymer).

[0050] 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 monohydroxypentaacrylate, dipropylene glycol diacrylate, trimethylolpropane triacrylate, glycerin propoxy triacrylate, 4-hydroxybutyl acrylate, 1,6-hexanediol diacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate. acrylates such as acrylate, isobornyl acrylate, polyethylene glycol diacrylate, pentaerythritol triacrylate, tetrahydrofurfuryl acrylate, and tripropylene glycol diacrylate; methacrylates such as 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, and trimethylolpropane trimethacrylate;Examples of (meth)acrylamides include diacetone acrylamide, N,N-dimethylacrylamide, dimethylaminopropyl acrylamide, dimethylaminopropyl methacrylamide, methacrylamide, N-methylolacrylamide, acryloylformoline, N-methylacrylamide, N-isopropylacrylamide, Nt-butylacrylamide, N-phenylacrylamide, acryloylpiperidine, and 2-hydroxyethylacrylamide; The acrylic resin may be formed of one type of acrylic monomer or two or more types of acrylic monomers, and the adhesiveness can be adjusted by combining two or more types of acrylic monomers.

[0051] The acrylic resin may be a copolymer of an acrylic monomer and a vinyl monomer other than the acrylic monomer. Examples of vinyl monomers include styrene, α-methylstyrene, vinyl acetate, acrylonitrile, methacrylonitrile, and maleic anhydride. The content of the acrylic monomer unit in the copolymer is preferably 50 mol% or more and less than 100 mol%, and more preferably 70 mol% or more and 98 mol% or less. When the content of the acrylic monomer unit is equal to or more than the lower limit, adhesiveness can be easily exhibited. The content of the vinyl monomer unit in the copolymer can be, for example, from 2 mol % to 20 mol %.

[0052] The glass transition temperature of the acrylic resin is preferably 80°C or lower, more preferably 50°C or lower, and even more preferably 0°C or lower. Acrylic resins with a glass transition temperature higher than 80°C have low adhesiveness. The glass transition temperature of acrylic resins is -80°C or higher, and it is difficult to obtain acrylic resins with a glass transition temperature lower than that. The glass transition temperature of acrylic resins can be determined by differential scanning calorimetry or dynamic viscoelasticity measurement. Examples of acrylic monomers that tend to lower the glass transition temperature of acrylic resins include ethyl acrylate, butyl acrylate (particularly n-butyl acrylate), 2-ethylhexyl acrylate, etc. In acrylic resins, the higher the proportion of these monomer units, the lower the glass transition temperature.

[0053] 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 equal to or more than the lower limit, sufficient cohesive strength can be ensured. If it is equal to or less than the upper limit, adhesiveness can be further improved.

[0054] When the acrylic resin has an acrylic monomer unit having a reactive functional group, it may be cured by reacting with a curing agent. Curing the acrylic resin can improve the cohesive force of the pressure-sensitive adhesive layer, thereby improving its strength. In addition, by improving the cohesive force, it is possible to obtain a releasable pressure-sensitive adhesive layer that can be repeatedly bonded and peeled. 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 below, the reactive functional group is preferably a hydroxy group, a carboxy group, or an amino group, and more preferably a hydroxy group. Examples of acrylic monomers 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, and 4-hydroxybutyl methacrylate. Examples of the acrylic monomer having a carboxy group include acrylic acid, methacrylic acid, and itaconic acid. Examples of the acrylic monomer having an amino group include dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, and diethylaminoethyl methacrylate. Examples of acrylic monomers having an amide group include acrylamide, methacrylamide, N-methylol acrylamide, and N-methylol methacrylamide. Examples of the acrylic monomer having an epoxy group include glycidyl acrylate and glycidyl methacrylate. When a polyfunctional isocyanate is used as a curing agent, among the acrylic monomers having a reactive functional group, an acrylic monomer having a hydroxy group is preferred, and 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate are more preferred, taking into consideration curability and cost. The acrylic resin may be formed of one type of acrylic monomer having a reactive functional group, or two or more types of acrylic monomers.

[0055] (hardening 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 in terms of reactivity. In particular, when the adhesive contains acrylic monomer units having hydroxy groups, it is preferred that the curing agent be a polyfunctional isocyanate.

[0056] Examples of the polyfunctional isocyanate include aliphatic polyfunctional isocyanates, alicyclic polyfunctional isocyanates, and aromatic polyfunctional isocyanates. Specific examples of polyfunctional isocyanates 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, transcyclohexane 1,4-diisocyanate, 4,4'-dicyclomethane diisocyanate, 3, Examples of the isocyanate include 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, tetramethylxylene diisocyanate, 1,6,11-undecane triisocyanate, 1,3,6-hexamethylene triisocyanate, bicyclohepta triisocyanate, and trimethylhexamethylene diisocyanate. The polyfunctional isocyanate may be a modified diisocyanate formed from a 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, such as a polyurethane polyisocyanate obtained by reacting the polyfunctional isocyanate with a polyhydric alcohol, a polyisocyanate containing an isocyanurate ring obtained by polymerizing a polyfunctional isocyanate, or a polyisocyanate containing a biuret bond obtained by reacting a polyfunctional isocyanate with water. The type of curing agent used to cure the pressure-sensitive adhesive layer may be one type or two or more types.

[0057] [Base material] The substrate may be made of an insulating material or a conductive material. The shape of the substrate is not particularly limited, and examples thereof include a shape mainly having a flat surface, such as a film or a substrate. Examples of insulating materials include glass, synthetic resin, and ceramics. Examples of conductive materials include metals, conductive metal oxides, and carbon.

[0058] (Film substrate) Examples of the film substrate include plastic films made of synthetic resins, such as 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 elastomers, polyester-based elastomers, polyethersulfone, polyetherimide, polyetheretherketone, polyphenylene sulfide, polyimide, cellulose triacetate, and cellulose acetate propionate. From the viewpoint of improving the adhesion between the film substrate and the conductive layer, the synthetic resin for the film substrate is preferably a polyester resin, and among these, polyethylene terephthalate is preferred.

[0059] 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 a surface treatment such as corona discharge treatment, plasma treatment, or flame treatment in order to further improve the adhesion of the conductive layer.

[0060] The average thickness of the film substrate is preferably 5 μm or more and 500 μm or less, and more preferably 20 μm or more and 200 μm or less. When the average thickness of the film substrate is equal to or more than the lower limit, the film is less likely to break, and when the average thickness is equal to or less than the upper limit, the film can have sufficient flexibility. The average thickness of the film substrate is determined by measuring the thickness at 10 randomly selected locations and averaging the measured values.

[0061] (glass substrate) Examples of the glass substrate include an alkali-free glass substrate, a soda-lime glass substrate, a borosilicate glass substrate, and a quartz glass substrate. If the substrate contains an alkali component, the conductivity of the conductive layer tends to decrease. Therefore, among the glass substrates, an alkali-free glass is preferred. Here, alkali-free glass refers to a glass composition having an alkali component content of 0.1% by mass or less relative to the total mass of the glass composition.

[0062] The average thickness of the glass substrate is preferably 100 μm or more and 3000 μm or less, and more preferably 100 μm or more and 1000 μm or less. When the average thickness of the glass substrate is equal to or more than the lower limit, the glass substrate is less likely to break, and when the average thickness is equal to or less than the upper limit, the conductive laminate can be made thinner. The average thickness of the glass substrate is determined by measuring the thickness at 10 randomly selected locations and averaging the measured values.

[0063] <Method for manufacturing conductive laminate> A fourth aspect of the present invention is a method for producing a conductive laminate, which includes applying the conductive polymer-containing liquid of the first aspect to at least a part of the surface of a substrate. The conductive laminate of the third aspect can be obtained by the production method of this aspect.

[0064] Examples of a method for applying (coating) the conductive polymer-containing liquid to any surface of a substrate include a method using a coater such as a gravure coater, roll coater, curtain flow coater, spin coater, bar coater, reverse coater, kiss coater, fountain coater, rod coater, air doctor coater, knife coater, blade coater, cast coater, or screen coater; a method using a sprayer such as an air spray, airless spray, or rotor dampening; and an immersion method such as dipping.

[0065] The amount of conductive polymer-containing liquid to be applied to the substrate is not particularly limited, but taking into consideration the need for uniform and even application, conductivity, and film strength, it is recommended to apply a solid content of 0.01 g / m 2 More than 10.0g / m 2 The following ranges are preferred:

[0066] The conductive layer can be formed by drying the coating film made of the conductive polymer-containing liquid applied onto the substrate to remove at least a portion of the dispersion medium and then curing the coating film. Methods for drying the coating film include heat drying, vacuum drying, etc. Heat drying can be performed using, for example, hot air heating or infrared heating. When heat drying is applied, the heating temperature is appropriately set depending on the dispersion medium used, but is usually within the range of 50°C to 200°C. Here, the heating temperature is the temperature set in the drying device. A suitable drying time within the above heating temperature range is preferably 0.5 minutes to 30 minutes, more preferably 1 minute to 15 minutes. After drying, UV irradiation may be carried out to cure the binder component contained in the coating film.

[0067] When a conductive layer is formed on one side of a film substrate and a pressure-sensitive adhesive layer is formed on the other side, the pressure-sensitive adhesive layer can be formed in the same manner as the conductive layer by applying a coating material containing a pressure-sensitive adhesive to the other side. The coating material containing a pressure-sensitive adhesive is not particularly limited, and known coating materials can be used. For example, the coating material containing the above-mentioned acrylic pressure-sensitive adhesive can be used. [Example]

[0068] [Production Example 1] Production of polystyrene sulfonic acid 206 g of sodium styrenesulfonate was dissolved in 1000 ml of ion-exchanged water, and while stirring at 80°C, 1.14 g of an oxidizing agent solution of ammonium persulfate, which had been dissolved in 10 ml of water in advance, was added dropwise over 20 minutes, and the solution was stirred for 12 hours. To the resulting sodium polystyrene sulfonate-containing solution, 1000 ml of sulfuric acid diluted to 10% by mass was added, and 1000 ml of the solvent from the resulting polystyrene sulfonic acid-containing solution was removed by ultrafiltration. Next, 2000 ml of ion-exchanged water was added to the remaining solution, and approximately 2000 ml of the solvent was removed by ultrafiltration, and the polystyrene sulfonic acid was washed with water. This water washing procedure was repeated three times. Water in the resulting solution was removed under reduced pressure to obtain colorless solid polystyrene sulfonic acid.

[0069] [Production Example 2] Production of conductive polymer dispersion containing iron ions A 0.5 g of 3,4-ethylenedioxythiophene (EDOT) and a PSS aqueous solution prepared by dissolving 1.5 g of polystyrene sulfonic acid in 15.0 g of ion-exchanged water were mixed at 20° C. Next, 89.5 g of ion-exchanged water was added. The resulting mixed solution was kept at 20°C and, while stirring, a catalyst solution prepared by dissolving 0.3 g of ferric sulfate in 4.7 g of ion-exchanged water and an oxidant solution prepared by dissolving 1.1 g of ammonium persulfate in 8.9 g of ion-exchanged water were slowly added, and the resulting reaction solution was stirred for 24 hours to allow the reaction to occur. Through the above reaction, a conductive composite (PEDOT-PSS) containing poly(3,4-ethylenedioxythiophene) and polystyrenesulfonic acid, which are π-conjugated conductive polymers, was obtained, along with water as a dispersion medium and a conductive polymer dispersion containing iron ions derived from ferric sulfate. To this conductive polymer-containing liquid, 13.2 g of Duolite C255LFH (a cation exchange resin manufactured by Sumika Chemtex Corporation) and 13.2 g of Duolite A368MS (an anion exchange resin manufactured by Sumika Chemtex Corporation) were added, and the mixture was filtered to remove the ion exchange resin, thereby obtaining a conductive polymer dispersion liquid (non-volatile component concentration 1.3% by mass) from which the oxidant and at least a portion of the catalyst had been removed. Next, the mixture was dispersed using a high-pressure homogenizer, and the amount of iron ions in the resulting conductive polymer dispersion was measured by ICP emission spectrometry, and was found to be 10 ppm.

[0070] [Production Example 3] Production of conductive polymer dispersion containing iron ions B A conductive polymer dispersion (non-volatile component concentration: 1.3 mass %) was obtained in the same manner as in Production Example 2, except that the amount of Duolite C255LFH in Production Example 2 was changed to 26.4 g. Next, the mixture was dispersed using a high-pressure homogenizer, and the amount of iron ions in the resulting conductive polymer dispersion was measured by ICP emission spectrometry, and was found to be 3 ppm.

[0071] [Production Example 4] Production of conductive polymer dispersion containing iron ions C A conductive polymer dispersion (non-volatile component concentration 1.3% by mass) was obtained in the same manner as in Production Example 2, except that the amount of Duolite C255LFH in Production Example 2 was changed to 33.0 g. Next, the mixture was dispersed using a high-pressure homogenizer, and the amount of iron ions in the resulting conductive polymer dispersion was measured by ICP emission spectrometry, and was found to be 1 ppm.

[0072] [Example 1] 10 g of the conductive polymer dispersion of Production Example 4 was mixed with 290 g of isopropanol and dispersed using a high-pressure homogenizer to obtain a conductive polymer-containing liquid (iron ion content: approximately 0.033 ppm). This was then applied to a PET film using a #4 bar coater and dried at 120°C for 1 minute to obtain a conductive film. The surface resistance of this conductive film was measured, and the results are shown in Table 1. The conductive polymer-containing liquid obtained in this example had good wettability with respect to the PET film, and no repellency was observed.

[0073] [Example 2] 10 g of the conductive polymer dispersion liquid of Production Example 4 and 140 g of isopropanol were mixed and dispersed using a high-pressure homogenizer to obtain a conductive polymer-containing liquid (iron ion content: approximately 0.067 ppm). Thereafter, a conductive film was obtained in the same manner as in Example 1. The results are shown in Table 1.

[0074] [Example 3] A conductive polymer-containing liquid (iron ion content: 0.100 ppm) and a conductive film were obtained in the same manner as in Example 1, except that 10 g of the conductive polymer dispersion of Production Example 4 was changed to 10 g of the conductive polymer dispersion of Production Example 3. The results are shown in Table 1.

[0075] [Example 4] A conductive polymer-containing liquid (iron ion content: 0.200 ppm) and a conductive film were obtained in the same manner as in Example 2, except that 10 g of the conductive polymer dispersion of Production Example 4 was changed to 10 g of the conductive polymer dispersion of Production Example 3. The results are shown in Table 1.

[0076] [Comparative Example 1] A conductive polymer-containing liquid (iron ion content: approximately 0.333 ppm) was obtained in the same manner as in Example 1, except that 10 g of the conductive polymer dispersion liquid of Production Example 4 was changed to 10 g of the conductive polymer dispersion liquid of Production Example 2. However, precipitation occurred immediately, and a conductive film could not be produced.

[0077] Comparative Example 2 A conductive polymer-containing liquid (iron ion content: approximately 0.667 ppm) was obtained in the same manner as in Example 2, except that 10 g of the conductive polymer dispersion liquid of Production Example 4 was changed to 10 g of the conductive polymer dispersion liquid of Production Example 2. However, precipitation occurred immediately, and a conductive film could not be produced.

[0078] Comparative Example 3 A conductive polymer-containing liquid (iron ion amount: approximately 0.033 ppm) and a conductive film were obtained in the same manner as in Example 1, except that isopropanol was changed to methanol. The results are shown in Table 1.

[0079] Comparative Example 4 A conductive polymer-containing liquid (iron ion amount: approximately 0.033 ppm) and a conductive film were obtained in the same manner as in Example 1, except that ethanol was used instead of isopropanol in Example 1. The results are shown in Table 1.

[0080] Comparative Example 5 A conductive polymer-containing liquid (iron ion amount: approximately 0.067 ppm) and a conductive film were obtained in the same manner as in Example 2, except that isopropanol was changed to methanol. The results are shown in Table 1.

[0081] Comparative Example 6 A conductive polymer-containing liquid (iron ion amount: approximately 0.067 ppm) and a conductive film were obtained in the same manner as in Example 2, except that ethanol was used instead of isopropanol in Example 2. The results are shown in Table 1.

[0082] [Surface resistance measurement] For the conductive films prepared in each example, the surface resistance of the conductive layer was measured using a resistivity meter (Hiresta manufactured by Nitto Seiko Analytech Co., Ltd.) under the condition of an applied voltage of 10 V. In the table, "2.0E+08" means "2.0 × 10 8 " and so on.

[0083] [Table 1]

[0084] Example 5 10 g of the conductive polymer dispersion from Production Example 4 was mixed with 280 g of isopropanol and dispersed using a high-pressure homogenizer. 10 g of PESRESIN A-645GH (manufactured by Takamatsu Oil & Fat Co., Ltd., epoxy group-containing acrylic resin and polyester resin liquid, solids content 30%, water-dispersed emulsion) was then added to obtain a conductive polymer-containing liquid (iron ion content: approximately 0.033 ppm). This was then applied to a PET film using a #4 bar coater and dried at 120°C for 1 minute to obtain a conductive film. The surface resistance of this conductive film was measured, and the results are shown in Table 2. The conductive polymer-containing liquid obtained in this example had good wettability with respect to the PET film, and no repellency was observed.

[0085] Example 6 A conductive film was produced and evaluated in the same manner as in Example 5, except that in Example 5, 10 g of the conductive polymer dispersion liquid of Production Example 4 was changed to 10 g of the conductive polymer dispersion liquid of Production Example 3 to obtain a conductive polymer-containing liquid (iron ion content: approximately 0.100 ppm). The results are shown in Table 2.

[0086] (Comparative Example 7) In Example 5, 10 g of the conductive polymer dispersion liquid of Production Example 4 was changed to 10 g of the conductive polymer dispersion liquid of Production Example 2, and a conductive polymer-containing liquid (iron ion content: approximately 0.333 ppm) was obtained, but precipitation occurred immediately, and a conductive film could not be produced.

[0087] [Table 2]

[0088] Example 7 An adhesive solution was obtained by mixing 60 g of an acrylic adhesive (SK Dyne 1499M, manufactured by Soken Chemical & Engineering Co., Ltd., solids concentration 35% by mass, ethyl acetate / butyl acetate mixed solution), 1.62 g of a curing agent, toluene diisocyanate-trimethylolpropane adduct (L-45, manufactured by Soken Chemical & Engineering Co., Ltd., solids concentration 45% by mass, toluene / ethyl acetate mixed solution), and 40 g of methyl ethyl ketone. The obtained adhesive solution was applied to the surface opposite the conductive layer of the conductive film obtained in Example 1 using a #16 bar coater, and dried for 1 minute at 100° C. The adhesive strength of the adhesive layer side at this time was measured and found to be 0.13 N / cm.

[0089] <Result> In the conductive polymer-containing liquid of each example according to the present invention, the amount of iron ions was 0.200 ppm or less, so that the conductive composite was sufficiently dispersed in the dispersion medium containing isopropanol, and as a result, the conductivity of the conductive layer was also good. In Comparative Examples 1, 2, and 7, the conductive polymer-containing liquid contained a large amount of iron ions, so the conductive complex was poorly dispersible, precipitated, and was not in a state suitable for application. In Comparative Examples 3 to 6, the conductive polymer-containing liquid did not contain isopropanol, so the wettability to the film substrate was poor, and it was difficult to form a conductive layer of uniform thickness over a large area or a desired area.

Claims

1. The monomer is polymerized in a reaction solution containing a polyanion, an aqueous dispersion medium, a monomer that forms a π-conjugated conductive polymer, and iron ions, a step of obtaining a conductive polymer dispersion (A) containing a conductive complex containing the π-conjugated conductive polymer and the polyanion, the aqueous dispersion medium, and the iron ions; a step of adding a cation exchange resin to the conductive polymer dispersion (A) to adsorb at least a portion of the iron ions, and then removing the cation exchange resin to obtain a conductive polymer dispersion (B); and adding at least isopropanol to the conductive polymer dispersion liquid (B) to obtain a conductive polymer-containing liquid, a content of the iron ions relative to the total mass of the conductive polymer dispersion liquid (B) is 5 ppm or less, and a content of the iron ions relative to the total mass of the conductive polymer-containing liquid is 0.200 ppm or less.

2. the conductive polymer-containing liquid contains the conductive complex containing the π-conjugated conductive polymer and the polyanion, and a dispersion medium; the dispersion medium contains water and isopropanol; 2. The method for producing a conductive polymer-containing liquid according to claim 1, wherein a content of the isopropanol relative to a total mass of the dispersion medium is 90 mass % or more.

3. 3. The method for producing a conductive polymer-containing liquid according to claim 2, wherein the content of the water relative to the total mass of the dispersion medium is 1% by mass or more and 10% by mass or less.

4. 4. The method for producing a conductive polymer-containing liquid according to claim 3, wherein the π-conjugated conductive polymer is poly(3,4-ethylenedioxythiophene).

5. The method for producing a conductive polymer-containing liquid according to claim 4 , wherein the polyanion is polystyrene sulfonic acid.

6. 6. The method for producing a conductive polymer-containing liquid according to claim 5, wherein the conductive polymer-containing liquid is stirred using a high-pressure homogenizer to disperse the conductive complex.

7. 7. The method for producing a conductive polymer-containing liquid according to claim 6, further comprising adding a binder component to the obtained conductive polymer-containing liquid.

8. A step of obtaining the conductive polymer-containing liquid by the manufacturing method according to any one of claims 1 to 7; and applying the conductive polymer-containing liquid to at least a portion of a surface of a substrate.

9. 9. The method for producing a conductive laminate according to claim 8, wherein the substrate is a film substrate, and the conductive polymer-containing liquid is applied to one surface of the film substrate to form a conductive layer made of a cured layer of the conductive polymer-containing liquid.

10. The method for producing a conductive laminate according to claim 9 , further comprising forming a pressure-sensitive adhesive layer on the other surface of the film substrate.

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