JP6222836B2 - Conductive polymer dispersion and conductive coating film - Google Patents

Description

  The present invention relates to a conductive polymer dispersion containing a π-conjugated conductive polymer and a conductive coating film.

A π-conjugated conductive polymer whose main chain is composed of a conjugated system containing π electrons can be synthesized by an electrolytic polymerization method and a chemical oxidative polymerization method.
In the electropolymerization method, a support such as a previously formed electrode material is immersed in a mixed solution of an electrolyte serving as a dopant and a precursor monomer that forms a π-conjugated conductive polymer, and the π-conjugated system is formed on the support. A conductive polymer is formed into a film. Therefore, it was difficult to manufacture in large quantities.
On the other hand, in the chemical oxidative polymerization method, there is no restriction like electrolytic polymerization, and an oxidant and an oxidation polymerization catalyst are added to the precursor monomer of the π-conjugated conductive polymer, and a large amount of π-conjugated conductive conductivity is increased in the liquid. Can produce molecules.
However, in the chemical oxidative polymerization method, as the conjugated system of the π-conjugated conductive polymer main chain grows, the solubility in a solvent becomes poor, so that an insoluble solid powder can be obtained. If it is insoluble, it becomes difficult to form a π-conjugated conductive polymer film uniformly on the support surface.
Therefore, a method of solubilizing by introducing a functional group into a π-conjugated conductive polymer, a method of solubilizing by dispersing in a binder, and a method of solubilizing by adding a polyanion have been proposed.
For example, in order to improve the dispersibility in water, 3,4-dialkoxythiophene is used in the presence of polystyrene sulfonic acid, which is a polyanion having a molecular weight in the range of 2,000 to 500,000, using an oxidizing agent. A method for producing a poly (3,4-dialkoxythiophene) aqueous dispersion by chemical oxidative polymerization has been proposed (see Patent Document 1). In addition, a method for producing a π-conjugated conductive polymer colloid aqueous dispersion by chemical oxidative polymerization in the presence of polyacrylic acid has been proposed (see Patent Document 2).

According to the methods described in Patent Documents 1 and 2, an aqueous dispersion containing a π-conjugated conductive polymer can be easily produced. However, the conductive coating film formed by applying the aqueous dispersion in Patent Documents 1 and 2 has low light resistance, and has a problem that the surface resistance rapidly increases when exposed to visible light or ultraviolet light. .
Then, the method of suppressing the raise of the surface resistance of the electroconductive coating film formed from the aqueous dispersion solution containing (pi) conjugated system conductive polymer by adding polyphosphoric acid etc. is proposed (patent document 3). However, even the method described in Patent Document 3 cannot sufficiently suppress the increase in surface resistance after irradiation with ultraviolet light, and the addition of polyphosphoric acid causes a new problem that the stability of the aqueous dispersion decreases. Also occurred.

Japanese Patent No. 2636968 Japanese Patent Laid-Open No. 7-165892 JP-T-2006-505099

  An object of the present invention is to provide a conductive polymer dispersion which can easily form a conductive coating film having high stability as a dispersion and excellent in light resistance. Moreover, it aims at providing the conductive coating film excellent in light resistance.

The present invention has the following aspects.
[1] and π-conjugated conductive polymer, a polyanion, a silane-coupling agent, contains a dispersion medium, wherein the silane coupling agent has an alkoxysilyl group and two or more epoxy groups The mass average molecular weight is 200 to 10000, and the content of the silane coupling agent is 50 to 1000 parts by mass when the total mass of the π-conjugated conductive polymer and the polyanion is 100 parts by mass. Conductive polymer dispersion.
[ 2 ] A conductive coating film formed by applying the conductive polymer dispersion according to [1 ] .

The conductive polymer dispersion of the present invention can easily form a conductive coating film having high stability as a dispersion and excellent light resistance.
The conductive coating film of the present invention is excellent in light resistance.

<Conductive polymer dispersion>
The conductive polymer dispersion of the present invention contains a π-conjugated conductive polymer, a polyanion, a polymer type polyfunctional silane coupling agent, and a dispersion medium.

(Π-conjugated conductive polymer)
The π-conjugated conductive polymer is an organic polymer whose main chain is composed of a π-conjugated system, for example, polypyrroles, polythiophenes, polyacetylenes, polyphenylenes, polyphenylene vinylenes, polyanilines, polyacenes, Examples thereof include polythiophene vinylenes and copolymers thereof. Of these, polythiophenes, polypyrroles and polyanilines are preferred from the viewpoint of ease of polymerization and stability in air. Furthermore, polythiophenes are preferable from the viewpoint of solubility in solvents and transparency.

Polythiophenes 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-chloro Thiophene), 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-ethoxy Offene), 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-didodeci) Oxythiophene), poly (3,4-ethylenedioxythiophene), poly (3,4-propylenedioxythiophene), poly (3,4-butenedioxythiophene), 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 polypyrroles 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) Le), poly (3-methyl-4-hexyloxy-pyrrole), poly (3-methyl-4-hexyloxy-pyrrole) and the like.
Examples of polyanilines include polyaniline, poly (2-methylaniline), poly (3-isobutylaniline), poly (2-aniline sulfonic acid), and poly (3-aniline sulfonic acid).
The above π-conjugated conductive polymers may be used alone or in combination of two or more.
Among the π-conjugated conductive polymers, poly (3,4-ethylenedioxythiophene) or polypyrrole is preferable from the viewpoint of conductivity, transparency, and heat resistance.

(Polyanion)
A polyanion is a polymer having a structural unit having an anion group. The anion group of the polyanion functions as a dopant for the π-conjugated conductive polymer, and improves the conductivity and heat resistance of the π-conjugated conductive polymer.
The anion group of the polyanion may be any functional group that can undergo chemical oxidation doping to the π-conjugated conductive polymer. Among them, from the viewpoint of ease of production and stability, a sulfonic acid group, mono-substituted A sulfate group, a monosubstituted phosphate group, a phosphate group, a carboxy group and the like are preferable. Furthermore, from the viewpoint of the doping effect of the functional group on the π-conjugated conductive polymer, a sulfonic acid group, a mono-substituted sulfate group, and a carboxy group are more preferable.
Specific examples of polyanions include polystyrene sulfonic acid, polyvinyl sulfonic acid, polyallyl sulfonic acid, polyacryl sulfonic acid, polymethacryl sulfonic acid, poly-2-acrylamido-2-methylpropane sulfonic acid, polyisoprene sulfonic acid, polyvinyl carboxylic acid. Examples include acid, polystyrene carboxylic acid, polyallyl carboxylic acid, polyacryl carboxylic acid, polymethacryl carboxylic acid, poly-2-acrylamido-2-methylpropane carboxylic acid, polyisoprene carboxylic acid, polyacrylic acid and the like. These homopolymers may be sufficient and 2 or more types of copolymers may be sufficient.
The said polyanion may be used individually by 1 type, and may use 2 or more types together.

  The degree of polymerization of the polyanion is preferably in the range of 10 to 100,000 monomer units, and more preferably in the range of 50 to 10,000 from the viewpoint of dispersibility and conductivity.

  The content of the polyanion is preferably in the range of 0.1 to 10 mol, and more preferably in the range of 1 to 7 mol, with respect to 1 mol of the π-conjugated conductive polymer. When the polyanion content is less than the lower limit, the doping effect on the π-conjugated conductive polymer tends to be weakened, and the conductivity may be insufficient. In addition, dispersibility and solubility are lowered, making it difficult to obtain a uniform dispersion. On the other hand, when the polyanion content exceeds the upper limit, the content of the π-conjugated conductive polymer decreases, and it is difficult to obtain sufficient conductivity.

In the polyanion, a part of its anion group is coordinated to the π-conjugated conductive polymer, and the π-conjugated conductive polymer and the polyanion form a complex. When the anion group of the polyanion is coordinated to the π-conjugated conductive polymer, the π-conjugated conductive polymer is doped to develop conductivity. Excess anionic groups that do not coordinate with the π-conjugated conductive polymer of the polyanion serve to solubilize the complex in water.
The content of the conductive complex (complex of π-conjugated conductive polymer and polyanion) in the conductive polymer dispersion is preferably 0.05 to 5.0% by mass, It is more preferable that it is 4.0 mass%. When the content of the conductive composite is less than 0.05% by mass, sufficient conductivity may not be obtained, and when it exceeds 5.0% by mass, a uniform conductive coating film cannot be obtained. There is.

(Polymer type polyfunctional silane coupling agent)
The polymer type polyfunctional silane coupling agent is a polymer type silane coupling agent having an alkoxysilyl group and two or more reactive functional groups (for example, an epoxy group, an amino group, etc.) other than the alkoxysilyl group. .
Among polymer-type polyfunctional silane coupling agents, a polymer-type polyfunctional silane coupling agent having two or more epoxy groups is preferable because the effect of improving light resistance is higher.

Examples of the polymer type polyfunctional silane coupling agent having two or more epoxy groups include compounds represented by the following general formula (1) or the following general formula (2).
In the formula (1), R ¹ , R ² and R ³ are each independently selected from a hydrogen atom, a glycidyl group and an alkoxysilyl group represented by the following general formula (3), and R ¹ , R ² and R ³ Is at least one alkoxysilyl group, and at least two of R ¹ , R ² and R ³ are glycidyl groups. a is an integer of 1 to 100, preferably an integer of 1 to 40, and more preferably an integer of 1 to 30.
In the formula (2), R ⁴ , R ⁵ and R ⁶ are each independently selected from a hydrogen atom, a glycidyl group and an alkoxysilyl group represented by the following general formula (3), and R ⁴ , R ⁵ and R ^6. Is at least one alkoxysilyl group, and at least two of R ⁴ , R ⁵ and R ⁶ are glycidyl groups. b is an integer of 4 to 10, preferably an integer of 4 to 8, and more preferably an integer of 4 to 5. c is an integer of 0 to 10, preferably an integer of 0 to 8, and more preferably an integer of 0 to 5. d is an integer of 0 to 10, preferably an integer of 0 to 8, and more preferably an integer of 0 to 5. e is an integer of 0 to 10, preferably an integer of 0 to 8, and more preferably an integer of 0 to 5.
In Formula (3), R ⁷ is an alkyl group having 1 to 6 carbon atoms, and X is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. n is an integer of 1 to 3.

In the compound represented by the general formula (1), the molar ratio (C / D) of the glycidyl group (C) and the alkoxysilyl group (D) is preferably 0.02 to 100, It is more preferable that it is 50, and it is still more preferable that it is 0.1-10.
In the compound represented by the general formula (2), the molar ratio (E / F) of the glycidyl group (E) and the alkoxysilyl group (F) is preferably 0.1 to 9, and preferably 0.2 to 5 is more preferable.

The epoxy equivalent of the polymer-type polyfunctional silane coupling agent (the mass of the resin containing 1 equivalent of an epoxy group) is preferably 100 to 500, more preferably 100 to 400, and more preferably 100 to 300. Further preferred. The epoxy equivalent can be determined according to JIS K7236: 2009. When the epoxy equivalent of the polymer type polyfunctional silane coupling agent is within the above range, the light resistance of the conductive coating film formed from the conductive polymer dispersion becomes higher.
The mass average molecular weight of the polymer type polyfunctional silane coupling agent is preferably 200 to 10,000, and more preferably 300 to 8,000. Here, the mass average molecular weight is a value measured by gel permeation chromatography (GPC) and obtained using standard polystyrene. If the mass average molecular weight of the polymer type polyfunctional silane coupling agent is equal to or higher than the lower limit, the light resistance of the conductive coating film formed from the conductive polymer dispersion becomes higher, and should be equal to or lower than the upper limit. For example, a polymer type polyfunctional silane coupling agent can be easily obtained.

  Specific examples of the polymer-type polyfunctional silane coupling agent having two or more epoxy groups include X-12-981 and X-12-984 manufactured by Shin-Etsu Chemical Co., Ltd.

The content ratio of the polymer type polyfunctional silane coupling agent is preferably 50 to 1000 parts by mass, and 80 to 700 parts by mass when the total mass of the π-conjugated conductive polymer and the polyanion is 100 parts by mass. More preferably, it is a part.
If the content ratio of the polymer-type polyfunctional silane coupling agent is equal to or higher than the lower limit, the light resistance of the conductive coating film formed from the conductive polymer dispersion can be further increased, and if the content is equal to or lower than the upper limit. Sufficient conductivity can be secured.

(Dispersion medium)
Examples of the dispersion medium contained in the conductive polymer dispersion include water, N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, hexamethylene phosphortriamide, acetonitrile. , Polar solvents such as benzonitrile, phenols such as cresol, phenol and xylenol, alcohols such as methanol, ethanol, propanol and butanol, ketones such as acetone and methyl ethyl ketone, hydrocarbons such as hexane, benzene and toluene, formic acid , Carboxylic acids such as acetic acid, carbonate compounds such as ethylene carbonate and propylene carbonate, ether compounds such as dioxane and diethyl ether, ethylene glycol dialkyl ether, propylene glycol dialkyl ether , Chain ethers such as polyethylene glycol dialkyl ether and polypropylene glycol dialkyl ether, heterocyclic compounds such as 3-methyl-2-oxazolidinone, nitrile compounds such as acetonitrile, glutaronitrile, methoxyacetonitrile, propionitrile, and benzonitrile Etc. These solvents may be used alone, as a mixture of two or more kinds, or as a mixture with other organic solvents.

(Binder)
The conductive polymer dispersion may contain a binder for the purpose of improving the durability and transparency of the conductive coating film formed from the conductive polymer dispersion and improving the adhesion to the substrate. .
The binder may be a thermosetting resin or a thermoplastic resin. For example, polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyimide, polyamideimide, polyamide 6, polyamide 6,6, polyamide 12, polyamide 11, etc., polyvinyl alcohol, polyvinyl butyral, polyvinyl acetate, polychlorinated Examples thereof include vinyl resins such as vinyl, epoxy resins, oxetane resins, xylene resins, aramid resins, polyimide silicones, polyurethanes, polyureas, melamine resins, phenol resins, polyethers, acrylic resins, and copolymers thereof.
Among the binders, polyester, polyurethane, melamine resin, oxetane resin, epoxy resin, and acrylic resin are preferable because of high adhesion to the substrate.

  The binder content is preferably 1000 to 100000 parts by mass, and more preferably 3000 to 50000 parts by mass with respect to 100 parts by mass of the composite. If the binder is not less than the lower limit, the strength of the resulting conductive coating film can be sufficiently improved, and if it is not more than the upper limit, sufficient conductivity can be ensured.

(Additive)
The conductive polymer dispersion may contain additives as necessary.
The additive is not particularly limited as long as it can be mixed with a π-conjugated conductive polymer and a polyanion. For example, an inorganic conductive agent, a surfactant, an antifoaming agent, a non-polymer type coupling agent, an antioxidant Agents, ultraviolet absorbers and the like can be used.
Examples of the inorganic conductive agent include metal ions (formed by dissolving a metal salt in water), conductive carbon, and the like.
Surfactants include anionic surfactants such as carboxylates, sulfonates, sulfates and phosphates; cationic surfactants such as amine salts and quaternary ammonium salts; carboxybetaines and aminocarboxylics Examples include amphoteric surfactants such as acid salts and imidazolium betaines; nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene glycerin fatty acid esters, ethylene glycol fatty acid esters, and polyoxyethylene fatty acid amides.
Examples of the antifoaming agent include silicone resin, polydimethylsiloxane, and silicone resin.
Examples of the non-polymer type coupling agent include a non-polymer type (mass average molecular weight of less than 200) silane coupling agent having a vinyl group, an amino group, an epoxy group, and the like.
Examples of the antioxidant include phenolic antioxidants, amine antioxidants, phosphorus antioxidants, sulfur antioxidants, saccharides, vitamins and the like.
Examples of UV absorbers include benzotriazole UV absorbers, benzophenone UV absorbers, salicylate UV absorbers, cyanoacrylate UV absorbers, oxanilide UV absorbers, hindered amine UV absorbers, and benzoate UV absorbers. Is mentioned. It is preferable to use an antioxidant and an ultraviolet absorber in combination.

(Method for producing conductive polymer dispersion)
As a method for producing the conductive polymer dispersion, for example, a precursor monomer of a π-conjugated conductive polymer is chemically oxidatively polymerized in the presence of a polyanion and a dispersion medium, and a π-conjugated conductive polymer is obtained. An example is a method in which after obtaining a dispersion solubilized in a dispersion medium by a polyanion, a polymer type polyfunctional silane coupling agent is added to the dispersion.

<Conductive coating film>
The conductive coating film of the present invention is a coating film formed by applying the conductive polymer dispersion.
The conductive coating film is usually formed by coating on a substrate. Here, although it does not restrict | limit especially as a base material, Since a conductive coating film has transparency, it is preferable that a base material is also transparent.
The materials constituting the transparent substrate include polyethylene terephthalate (PET), polyethylene naphthalate, polyethersulfone, polyetherimide, polyetheretherketone, polyphenylene sulfide, polyarylate, polyimide, polycarbonate, cellulose triacetate, and cellulose acetate propio. And the like. Glass can also be used as the transparent substrate.
In addition, paper such as high-quality paper, kraft paper, and coated paper can be used as the substrate.

As a coating method of the conductive polymer dispersion, for example, bar coating, comma coating, reverse coating, lip coating, spray coating, flexographic printing, gravure printing and the like are applied.
It is preferable to perform a curing treatment after the application of the conductive polymer dispersion.
As the curing method, heating or light irradiation is applied. As a heating method, for example, a normal method such as hot air heating or infrared heating can be employed. Moreover, when hardening by light irradiation, the method of irradiating ultraviolet light from light sources, such as an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc, a xenon arc, a metal halide lamp, can be employ | adopted, for example.
The illuminance upon irradiation with ultraviolet light is preferably 100 mW / cm ² or more. If the illuminance is less than 100 mW / cm ² , the film may not be sufficiently crosslinked. In addition, the illumination intensity in this invention is the value measured using Topcon Co., Ltd. UVR-T1 (Industrial UV checker, light receiver; UD-T36, measurement wavelength range; 300-390 nm, peak sensitivity wavelength; about 355 nm). .

  The thickness (average value) of the conductive coating film is preferably 0.001 to 10 μm, and more preferably 0.01 to 1 μm. If the thickness of the conductive coating film is not less than the lower limit value, sufficient conductivity can be ensured, and if the thickness is not more than the upper limit value, sufficient flexibility can be ensured.

(Function and effect)
When a conductive coating film is formed from the conductive polymer dispersion of the present invention containing a polymer-type polyfunctional silane coupling agent, a complex of a π-conjugated conductive polymer and a polyanion is highly crosslinked. The light resistance of the conductive coating film is increased. Therefore, even if the conductive coating film formed from the conductive polymer dispersion of the present invention is irradiated with ultraviolet light, the surface resistance is hardly increased.
In the case where a monomer type silane coupling agent or an oligomer type silane coupling agent is contained in the conductive polymer dispersion instead of the polymer type polyfunctional silane coupling agent, the silane coupling agent is silsesquioxane. For example, the siloxane bond is not sufficiently formed. For this reason, the conductive composites cannot be sufficiently crosslinked with each other, and the effect of improving light resistance is small.

(Production Example 1) Synthesis of polystyrene sulfonic acid 206 g of sodium styrene sulfonate was dissolved in 1000 ml of ion-exchanged water, and while stirring at 80 ° C., 1.14 g of ammonium persulfate oxidizing agent solution previously dissolved in 10 ml of water was dissolved. The solution was added dropwise for 20 minutes, and the solution was stirred for 12 hours.
To the obtained sodium styrenesulfonate-containing solution, 1000 ml of sulfuric acid diluted to 10% by mass was added, about 1000 ml of the polystyrenesulfonic acid-containing solution was removed using an ultrafiltration method, and 2000 ml of ion-exchanged water was added to the remaining liquid. And about 20,000 ml solution was removed using ultrafiltration. The above ultrafiltration operation was repeated three times.
Further, about 2000 ml of ion-exchanged water was added to the obtained filtrate, and about 2000 ml of solution was removed using an ultrafiltration method. This ultrafiltration operation was repeated three times. Then, water in the obtained solution was removed under reduced pressure to obtain colorless solid polystyrene sulfonic acid.

(Production Example 2) Preparation of conductive polymer dispersion 14.2 g of 3,4-ethylenedioxythiophene and a solution of 36.7 g of polystyrene sulfonic acid dissolved in 2000 ml of ion-exchanged water were mixed at 20 ° C. I let you.
While keeping the mixed solution thus obtained at 20 ° C. and stirring, 29.64 g of ammonium persulfate dissolved in 200 ml of ion exchange water and 8.0 g of ferric sulfate oxidation catalyst solution were slowly added and stirred for 3 hours. And reacted.
2000 ml of ion-exchanged water was added to the reaction solution thus obtained, and about 2000 ml of solution was removed using an ultrafiltration method. This operation was repeated three times.
Then, 200 ml of sulfuric acid diluted to 10% by mass and 2000 ml of ion-exchanged water are added to the obtained solution, about 2000 ml of solution is removed by ultrafiltration, 2000 ml of ion-exchanged water is added thereto, and ultrafiltration is performed. About 2000 ml of solution was removed by the method. This operation was repeated three times.
Furthermore, 2000 ml of ion-exchanged water was added to the obtained solution, and about 2000 ml of solution was removed by ultrafiltration. This operation was repeated 5 times to obtain about 1.2% by mass of a blue polystyrenesulfonic acid-doped poly (3,4-ethylenedioxythiophene) dispersion (hereinafter referred to as “PEDOT-PSS dispersion”).

Example 1
To 200 g of a mixed solution of 100 g of PEDOT-PSS dispersion obtained in Production Example 2 and 100 g of ethanol, a silane coupling agent (X-12-984, manufactured by Shin-Etsu Chemical Co., Ltd., polymer type polyfunctional having two or more epoxy groups) Silane coupling agent, mass average molecular weight 4.0 × 10 ³ , epoxy equivalent 270, viscosity 1860 mPa · s) 8 g (333 parts by mass with respect to 100 parts by mass of PEDOT-PSS solid content) was added and stirred to be conductive. A polymer dispersion A was obtained.
Conductive polymer dispersion A was applied to a polyethylene terephthalate film (Toyobo A4300, thickness: 188 μm) with a # 8 bar coater and dried by heating at 120 ° C. for 3 minutes to form a conductive coating film. Thus, a conductive sheet was obtained.

[Light resistance evaluation]
The light resistance of the conductive coating film was evaluated by the following method. The results are shown in Tables 1 and 2.
After measuring the initial surface resistance of the conductive coating film of the obtained conductive sheet, the conductive sheet was irradiated with ultraviolet light generated by a carbon arc for 96 hours or 480 hours using an ultraviolet fade meter. . And the surface resistance of the conductive coating film after light irradiation was measured. The measurement results are shown in Tables 1 and 2. The smaller the increase in surface resistance after light irradiation, the better the light resistance.
The surface resistance was measured in accordance with JIS K6911 using a Hiresta MCP-HT450 manufactured by Mitsubishi Chemical Corporation.

[Transparency evaluation]
The total light transmittance and haze were measured according to JIS K7136 using a Nippon Denshoku Industries Co., Ltd. haze meter measuring device (NDH5000).

(Example 2)
X-12-981 manufactured by Shin-Etsu Chemical Co., Ltd. (polymer type polyfunctional silane coupling agent having two or more epoxy groups, mass average molecular weight 3.0 × 10 ³ , epoxy equivalent 290, viscosity 1010 Pa · A conductive polymer dispersion B was obtained in the same manner as in Example 1 except for changing to s). A conductive sheet was obtained by forming a conductive coating film in the same manner as in Example 1 except that the conductive polymer dispersion B was used instead of the conductive polymer dispersion A. Then, the light resistance was evaluated in the same manner as in Example 1.

(Example 3)
A conductive coating film was formed in the same manner as in Example 1 except that the addition amount of the silane coupling agent X-12-984 was changed to 2 g (83 parts by mass with respect to 100 parts by mass of PEDOT-PSS solid content). A conductive sheet was obtained. Then, the light resistance was evaluated in the same manner as in Example 1.

Example 4
A conductive coating film was formed in the same manner as in Example 1 except that the addition amount of the silane coupling agent X-12-984 was changed to 4 g (167 parts by mass with respect to 100 parts by mass of PEDOT-PSS solid content). A conductive sheet was obtained. Then, the light resistance was evaluated in the same manner as in Example 1.

(Example 5)
A conductive coating film was formed in the same manner as in Example 1 except that the addition amount of the silane coupling agent X-12-984 was changed to 16 g (666 parts by mass with respect to 100 parts by mass of PEDOT-PSS solid content). A conductive sheet was obtained. Then, the light resistance was evaluated in the same manner as in Example 1.

(Comparative Example 1)
A conductive coating film was formed in the same manner as in Example 1 except that the silane coupling agent was not added to obtain a conductive sheet. Then, the light resistance was evaluated in the same manner as in Example 1.

(Comparative Example 2)
1 g of silane coupling agent manufactured by Shin-Etsu Chemical Co., Ltd. KBM403 (3-glycidoxypropyltriethoxysilane, non-polymer silane coupling agent having one epoxy group) (83 parts by mass based on 100 parts by mass of PEDOT-PSS solid content) A conductive polymer dispersion C was obtained in the same manner as in Example 1 except that the mass was changed to (parts by mass). A conductive sheet was obtained by forming a conductive coating film in the same manner as in Example 1 except that the conductive polymer dispersion C was used instead of the conductive polymer dispersion A. Then, the light resistance was evaluated in the same manner as in Example 1.

(Comparative Example 3)
A conductive polymer dispersion D was obtained in the same manner as in Comparative Example 2 except that the amount of KBM403 manufactured by Shin-Etsu Chemical Co., Ltd. was changed to 2 g (167 parts by mass with respect to 100 parts by mass of PEDOT-PSS solid content). A conductive sheet was obtained by forming a conductive coating film in the same manner as in Example 1 except that the conductive polymer dispersion D was used instead of the conductive polymer dispersion A. Then, the light resistance was evaluated in the same manner as in Example 1.

(Comparative Example 4)
A conductive polymer dispersion E was obtained in the same manner as in Comparative Example 2 except that the amount of KBM403 manufactured by Shin-Etsu Chemical Co., Ltd. was changed to 4 g (333 parts by mass with respect to 100 parts by mass of PEDOT-PSS solid content). A conductive sheet was obtained by forming a conductive coating film in the same manner as in Example 1 except that the conductive polymer dispersion E was used instead of the conductive polymer dispersion A. Then, the light resistance was evaluated in the same manner as in Example 1.

(Comparative Example 5)
A silane coupling agent was made by Shin-Etsu Chemical Co., Ltd. KBM402 (3-glycidoxypropylmethyldimethoxysilane, non-polymer type silane coupling agent having one epoxy group) 2 g (based on 100 parts by mass of PEDOT-PSS solid content) A conductive polymer dispersion F was obtained in the same manner as in Example 1 except that the mass was changed to (parts by mass). A conductive sheet was obtained by forming a conductive coating film in the same manner as in Example 1 except that the conductive polymer dispersion F was used instead of the conductive polymer dispersion A. Then, the light resistance was evaluated in the same manner as in Example 1.

(Comparative Example 6)
Silane coupling agent is KBG503 (3-methacryloxypropyltrimethoxysilane, methacrylic non-polymeric silane coupling agent) manufactured by Shin-Etsu Chemical Co., Ltd. 2 g (167 parts by mass with respect to 100 parts by mass of PEDOT-PSS solid content). A conductive polymer dispersion G was obtained in the same manner as Example 1 except for the change. A conductive sheet was obtained by forming a conductive coating film in the same manner as in Example 1 except that the conductive polymer dispersion G was used instead of the conductive polymer dispersion A. Then, the light resistance was evaluated in the same manner as in Example 1.

(Comparative Example 7)
Silane coupling agent is KBE 5103 (3-acryloxypropyltrimethoxysilane, acrylic non-polymer type silane coupling agent) manufactured by Shin-Etsu Chemical Co., Ltd. 2 g (167 parts by mass with respect to 100 parts by mass of PEDOT-PSS solid content) A conductive polymer dispersion H was obtained in the same manner as in Example 1 except for the change. A conductive sheet was obtained by forming a conductive coating film in the same manner as in Example 1 except that the conductive polymer dispersion H was used instead of the conductive polymer dispersion A. Then, the light resistance was evaluated in the same manner as in Example 1.

The conductive coating films of Examples 1 to 5 formed from a conductive polymer dispersion containing a polymer-type polyfunctional silane coupling agent had a small increase in surface resistance after irradiation with ultraviolet light and were excellent in light resistance.
The conductive coating film of Comparative Example 1 formed from a conductive polymer dispersion containing no silane coupling agent had a large increase in surface resistance after irradiation with ultraviolet light and low light resistance.
The conductive coating films of Comparative Examples 2 to 7 formed from a conductive polymer dispersion containing a non-polymer type silane coupling agent instead of no polymer type polyfunctional silane coupling agent had a surface resistance after ultraviolet light irradiation. The rise of the light was large and the light resistance was low.

Claims (2)

a π-conjugated conductive polymer, a polyanion, a silane-coupling agent, contains a dispersion medium, wherein the silane coupling agent has an alkoxysilyl group and two or more epoxy groups, weight average The molecular weight is 200-10000,
The conductive polymer dispersion, wherein the content of the silane coupling agent is 50 to 1000 parts by mass when the total mass of the π-conjugated conductive polymer and the polyanion is 100 parts by mass . A conductive coating film formed by applying the conductive polymer dispersion according to claim 1 .