TW201925370A - Transparent conductive film, coating composition for forming transparent conductive film, and manufacturing method of transparent conductive film wherein the transparent conductive film is excellent in heat and humidity resistance and weather resistance - Google Patents

Abstract

The subject of the present invention is to provide a transparent conductive film excellent in heat and humidity resistance and weather resistance, and a coating composition excellent in storage stability for forming the transparent conductive film. To solve the problem, the transparent conductive film includes conductive polymer containing a polythiophene compound/polystyrene sulfonic acid, an inorganic binder containing a silane compound, an inorganic acid, and a surface modifier that are formed on one surface of a transparent substrate, wherein the content of the inorganic acid is in an amount of less than 30% by mass based on the content of the conductive polymer.

Description

Transparent conductive film, coating composition for forming transparent conductive film, and method for manufacturing transparent conductive film

The present invention relates to a transparent conductive film formed on one side of a transparent substrate, a coating composition for forming the transparent conductive film, and a method for producing the transparent conductive film.

Since thiophene-based or aniline-based polymers have excellent stability and electrical conductivity, they are expected to be utilized as organic conductive materials. As one of the applications, transparent electrodes and anti-charge films used in various devices such as liquid crystal displays and transparent touch panels are highly conductive by using an inorganic adhesive to bond an additional dopant to the polymer. Molecular transparent conductive film.

For example, Patent Document 1 describes that a transparent conductive film is provided on a transparent substrate, the transparent conductive film is a particulate inorganic adhesive containing a conductive polymer and a silane compound, and the conductive polymer is described above. The transparent conductive sheet is arranged between the particles of the inorganic adhesive. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2016-170914

[Problems to be Solved by the Invention]

In recent years, the performance requirements for transparent electrodes and anti-static films used in various devices have been improved. For transparent conductive films in which conductive polymers are bonded with inorganic adhesives, moist heat resistance and weather resistance have also been improved. . In particular, since the coating composition used to form the transparent conductive film changes its characteristics within a short time, it is difficult to efficiently produce a transparent conductive film having excellent uniformity in film thickness.

The present invention is to solve the above problems, and it is set that the object is to provide a transparent conductive film excellent in moist heat resistance and weather resistance, and a coating composition having excellent storage stability for forming the transparent conductive film. [Means to solve the problem]

The present invention is a transparent conductive film formed on one side of a transparent substrate. The transparent conductive film is a conductive polymer containing a polythiophene compound / polystyrene sulfonic acid, and an inorganic adhesive containing a silane compound. Inorganic acids and surface modifiers, characterized in that a transparent conductive film is provided, and the inorganic acid is contained in an amount of 30% by mass or less based on the content of the conductive polymer.

In a certain aspect, the transparent conductive film is an amount of 10% by mass or less based on the content of the conductive polymer, and further includes an antioxidant.

In one aspect, the inorganic acid is at least one selected from the group consisting of phosphoric acid, hydrochloric acid, and sulfuric acid.

In a certain aspect, the antioxidant is a quinone compound.

In a certain aspect, the conductive polymer is contained in an amount of 1 to 75% by mass based on the total amount of the conductive polymer and the inorganic adhesive.

The present invention is a coating composition containing a conductive polymer containing a polythiophene compound / polystyrene sulfonic acid, a silane compound, an inorganic acid, a surface modifier, and an aqueous solvent. A coating composition containing the conductive polymer in an amount of 30% by mass or less based on the content of the conductive polymer.

In a certain aspect, the coating composition contains an antioxidant in an amount of 10% by mass or less based on the content of the conductive polymer as a reference.

The present invention also provides a method for producing a transparent conductive film, which comprises applying a coating composition to one of the surfaces of a transparent substrate to form a coating film, and drying and curing the coating film. Film formation steps.

In one aspect, the coating is performed using a spray coating method. [Effect of the invention]

According to the present invention, it is possible to provide a transparent conductive film excellent in moist heat resistance and weather resistance, and a coating composition having excellent storage stability for forming the transparent conductive film.

<Transparent conductive film> The so-called conductive polymers are polymers called Conductive Polymers (CPs), which are said to be doped by dopants to form polyradical cation salts or polyfree radicals. In the state of an anionic salt, the polymer itself can exhibit conductivity.

In the present invention, a polythiophene compound and a dopant are used as the conductive polymer. As the conductive polymer system of the present invention, a mixture containing poly (3,4-ethylenedioxythiophene) as a polythiophene compound and a polystyrenesulfonic acid (also called PEDOT / PSS.). PEDOT / PSS is useful because it is excellent in electrical conductivity, moisture and heat resistance, and weather resistance.

As the inorganic binder, a binder having a high transparency and containing a silane compound which can constitute a particulate inorganic binder is used. By forming the inorganic adhesive in a particulate form, and by disposing the conductive polymer between the particles of the inorganic adhesive, the electrical characteristics of the transparent conductive film of the transparent conductive sheet of the present invention can be improved.

The major axis diameter of the particles of the inorganic adhesive is preferably 10 nm or more and 300 nm or less, and more preferably 20 nm or more and 200 nm or less. This is because if the major axis diameter of the particles of the inorganic adhesive is within the range, the conductive path formed by the conductive polymer can be densely formed.

In the present invention, the major axis diameter of the particles of the inorganic binder is observed with a scanning electron microscope, and the cross-section of the transparent conductive film is obtained. The average value is calculated.

The conductive polymer is used in an amount of 1 to 75% by mass based on the total amount of the conductive polymer and the inorganic adhesive. If the used amount of the conductive polymer is less than 1% by mass based on the total amount of the conductive polymer and the inorganic adhesive, the surface resistance of the transparent conductive film will increase, and the electrical characteristics will deteriorate. % By mass, the adhesion of the coating film is reduced. The used amount of the conductive polymer is based on the total amount of the conductive polymer and the inorganic adhesive, and is preferably 5 to 50% by mass, and more preferably 10 to 25% by mass.

Examples of the inorganic acid include phosphoric acid, hydrochloric acid, and sulfuric acid. A particularly preferred inorganic acid is phosphoric acid. The inorganic acid is used in an amount of 30% by mass or less based on the content of the conductive polymer. When the amount of the inorganic acid exceeds 30% by mass based on the content of the conductive polymer, the inorganic acid reacts with the conductive polymer, so the weather resistance of the transparent conductive film is reduced, and the storage stability of the coating composition is stable. Sex decreased. The amount of the inorganic acid used is based on the content of the conductive polymer, and is preferably less than 30% by mass, more than 5% by weight, and less than 30% by mass, and more preferably 7 to 25% by mass.

The transparent conductive film may further include an antioxidant. By using an antioxidant, the moisture and heat resistance and weather resistance of the transparent conductive film are improved, and the storage stability of the coating composition is further improved. As the antioxidant, a quinone compound, a nitrosamine compound, a phenol-based antioxidant, or the like is used.

Examples of the quinone compound system include hydroquinone, methoquinone, methylhydroquinone, 4-tert-butylcatechol tert-butylhydroquinone, 1,4-benzoquinone, dibutylhydroxytoluene, 1 , 1-diphenyl-2-trinitrophenylhydrazine free radical, methoxyphenol, phenothiazine, 4-hydroxy TEMPO, etc. Examples of the nitrosamine compound system include N-nitroso-N-phenylhydroxylamine, N-nitroso-N-phenylhydroxylamine aluminum salt, and N-nitroso-N-phenylhydroxylamine cerium salt. . Examples of the phenol-based antioxidant include 2,6-di-tertiary-butyl-4-methylphenol, propyl gallate, and 2,4,5-trihydroxybutyrophenone. Dihydroguaiaretic acid, butyl hydroxyanisole, octyl gallate, dibutyl hydroxytoluene, and dodecyl gallate.

A particularly preferred antioxidant is hydroquinone. The antioxidant is used in an amount of 20% by mass or less based on the content of the conductive polymer. When the amount of the antioxidant is more than 20% by mass based on the content of the conductive polymer, the ratio of the inorganic adhesive is reduced and the hardness of the coating film is reduced. Therefore, the amount of the antioxidant is to be highly conductive. The molecular content is used as a reference, preferably 1 to 15% by mass, and more preferably 2 to 10% by mass.

The transparent conductive film may further include an organic adhesive. When the transparent conductive film contains an organic adhesive, the adhesion between the transparent conductive film and the transparent substrate can be improved. In particular, when a flexible substrate such as a plastic film is used as the transparent substrate, the case where the transparent conductive film includes an organic binder is the adhesion or followability of the transparent conductive film and the transparent substrate. From a viewpoint, it is better.

Examples of the organic adhesive include acrylic resin, melamine resin, polyester resin, polyamide resin, polycarbonate resin, polyurethane resin, polystyrene resin, polyvinyl chloride resin, and polyvinylidene chloride. Vinyl chloride resin, polyvinyl acetate resin, polyvinylidene fluoride resin, hydroxyethyl cellulose, polyvinyl alcohol, polyethylene glycol (PEG), polyethylene oxide, polypropylene oxide, polysaccharides, Other photopolymerizable resins. In addition, as the use form of the organic binder, a solvent-soluble type or an emulsion type can be used. If the content of the organic-based adhesive is too large, the effect of the inorganic-based adhesive decreases, so the content of the organic-based adhesive is limited to a range that does not cause such problems.

The surface resistance value of the transparent conductive film is preferably 150 to 3000 Ω / □. The smaller the surface impedance value is, the better the electrical characteristics are. The surface resistance value of the transparent conductive film is more preferably 250 to 2000 Ω / □, and further preferably 500 to 1000 Ω / □.

The thickness of the transparent conductive film is appropriately set depending on the application, and is usually about 0.01 to 5 μm. If the film thickness is too thin or too thick, it becomes difficult to form a uniform transparent conductive film. The film thickness of the transparent conductive film is preferably 0.05 to 1 μm, and more preferably 0.1 to 0.3 μm.

The haze of the transparent conductive film is preferably 2% or less. A lower haze value indicates higher transparency. The haze can be measured by a haze meter, for example, NDH2000 manufactured by Nippon Denshoku Industries, Ltd. The haze of the transparent conductive film is more preferably 1% or less, and further preferably 0.5% or less.

The total light transmittance of the transparent conductive film is preferably 90% or more. The higher the total light transmittance, the better the optical characteristics. The total light transmittance can be measured by a spectrophotometer, such as "V-570" manufactured by JASCO Corporation. The total light transmittance of the transparent conductive film is more preferably 93% or more, and further preferably 95% or more.

The hardness of the transparent conductive film is preferably a pencil hardness of 2H or more. The pencil hardness is determined according to the measurement method of Japanese Industrial Standard (JIS) K5400. The hardness of the transparent conductive film is more preferably a pencil hardness of 3H or more.

The moisture and heat resistance of the transparent conductive film is determined based on the change rate of the surface resistance value before and after the moisture and heat test stored for 240 hours in an environment with a temperature of 85 ° C and a relative humidity of 85%. The change rate of the surface resistance value before and after the moist heat test is preferably 100% or less.

The weather resistance of the transparent conductive film is determined based on the change rate of the surface resistance value before and after the exposure test stored for 120 hours under the irradiation of 60W / m ² (wavelength 300-400nm). The change rate of the surface resistance value before and after the exposure test is preferably 300% or less.

As the transparent base material, for example, various transparent materials including plastic, rubber, glass, and ceramic can be used.

<Coating composition for forming a transparent conductive film> (1) The content of the conductive polymer in the coating composition for forming a transparent conductive film is 0.01 to 10% by mass based on the entire coating composition. When coating with a surface resistance value of 150 to 3000 Ω / □, if the content of the conductive polymer is less than 0.01% by mass, the wet film thickness becomes 50 μm or more, and if it exceeds 10% by mass, the film thickness becomes It is difficult to control the thickness of the coating film by 1 μm. The content of the conductive polymer is based on the entire coating composition, and is preferably 0.05 to 0.5% by mass, and more preferably 0.08 to 0.3% by mass.

Silane compounds undergo hydrolysis and dehydration condensation. The silane compound is preferably an alkoxysilane. In addition, examples of the alkoxysilane type include at least one type of alkoxysilane selected from the group consisting of tetraalkoxysilane, trialkoxysilane, dialkoxysilane, and alkoxysilane oligomers. .

Examples of the tetraalkoxysilane include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetraisopropoxysilane, and tetra-third-butoxysilane. ~ 4 alkoxy and tetra-substituted silane. Specific examples include "KBE-04" (trade name) manufactured by Shin-Etsu Chemical Co., Ltd., and the like.

Examples of trialkoxysilanes include trimethoxysilane, triethoxysilane, tripropoxysilane, tributoxysilane, triisopropoxysilane, and tri-L-butoxysilane. It is a tri-substituted silane with an alkoxy group having 1 to 4 carbon atoms.

Examples of the dialkoxysilane include dimethyldimethoxysilane, diphenyldimethoxysilane, dimethyldiethoxysilane, diphenyldiethoxysilane, and the like.

Alkoxysilane oligomers are lower molecular weight resins with alkoxysilyl groups. Specific examples include "X-40-2308", "X-40-9225", "X-40-9226", "X-40-9238", "X-40-9247" manufactured by Shin-Etsu Chemical Co., Ltd. "," X-40-9250 "," KC-89S "," KR-220LP "," KR-401N "," KR-500 "," KR-510 "," KR-9218 "(brand name), "Ethyl Silicate 40", "Ethyl Silicate 48", "Methyl Silicate 51", "Methyl Silicate 53A", "EMS-485", "SS101" (from COLCOAT) Trade name) and so on.

Also, as the alkoxysilane type, vinylmethoxysilane, p-styrylmethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, Methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, decyltrimethoxysilane, trifluoropropyltrimethylsilane An alkoxysilane monomer such as oxysilane.

Further, tetraalkoxysilane and trialkoxysilane can be used in combination.

As the alkoxysilane, when using a combination of tetraalkoxysilane and trialkoxysilane, the molar ratio of tetraalkoxysilane and trialkoxysilane is preferably 9: 1 to 5: 5, and more It is preferably 8: 2 to 6: 4. The reason why this molar ratio is better is to prevent the hardness of the transparent conductive film from being lowered, and at the same time, there is no risk of cracks in the transparent conductive film due to changes over time, and it can be more improved with the transparent substrate. Closeness. Tetraalkoxysilanes are thought to act on the development of high film hardness, and trialkoxysilanes are thought to act to prevent the occurrence of cracks in transparent conductive films and to adhere to transparent substrates.

The content of the silane compound in the coating composition for forming a transparent conductive film is 0.05 to 10% by mass based on the entire coating composition. When the content of the silane compound is less than 0.05% by mass, the pencil hardness is low, and when it exceeds 10% by mass, the ink storage property is deteriorated. The content of the hafnium compound is based on the entire coating composition, and is preferably 0.1 to 5% by mass, and more preferably 0.3 to 3% by mass.

The content of the inorganic acid in the coating composition for forming a transparent conductive film is 0.0001 to 0.1% by mass based on the entire coating composition. If the content of the inorganic acid is less than 0.0001% by mass, the surface resistance after the reliability test is increased, and if it exceeds 0.1% by mass, the ink preservation property is deteriorated. The content of the inorganic acid is based on the entire coating composition, and is preferably 0.001 to 0.07 mass%, and more preferably 0.003 to 0.04 mass%.

The content of the antioxidant in the coating composition for forming a transparent conductive film is 0.1% by mass or less based on the entire coating composition. When the content of the antioxidant exceeds 0.1% by mass, the pencil hardness decreases. The content of the antioxidant is based on the entire coating composition, and is preferably 0.05% by mass or less, and more preferably 0.03% by mass or less. The coating composition system for forming a transparent conductive film may not contain an antioxidant.

The content of the organic binder in the coating composition for forming a transparent conductive film is 50% by mass or less based on the entire coating composition. When the content of the organic-based adhesive exceeds 50% by mass, the surface resistance after the reliability test increases.含量 The content of the organic binder is based on the entire coating composition, and is preferably 25% by mass or less, and more preferably 10% by mass or less. The coating composition for forming a transparent conductive film may not contain an organic binder.

As the surface conditioner, a silicon-based surface conditioner can be used, and for example, a siloxane-based surface conditioner is used. The surface modifier is used in an amount of 0.01 to 10% by mass based on the entire coating composition. The thickness of the transparent conductive film, especially the spray coating film, is adjusted by adjusting the amount of the surface modifier used to the above range. The amount of the surface modifier used is based on the entire coating composition, and is preferably 0.02 to 5% by mass, and more preferably 0.05 to 0.3% by mass.

The aqueous solvent is a solvent containing water. The aqueous solvent system preferably contains a protic polar solvent and an aprotic polar solvent. By using a protic polar solvent and an aprotic polar solvent together, a transparent conductive film having excellent transparency can be obtained at a lower drying temperature.

Examples of the protic polar solvent system include water, ethanol, methanol, n-propanol, isopropanol, n-butanol, isobutanol, ethylene glycol, propylene glycol, and acetic acid. Examples of the aprotic polar solvent system include Dimethyl sulfene, N-methylpyrrolidone, N-ethylpyrrolidone, N, N-dimethylformamidine, acetonitrile, acetone, tetrahydrofuran and the like are produced. Particularly preferred aqueous solvents are those containing dimethyl sulfene, water and ethanol.

Examples of the aprotic polar solvent system include dimethylsulfinium, N-methylpyrrolidone, N-ethylpyrrolidone, N, N-dimethylformamidine, acetonitrile, acetone, and tetrahydrofuran. .

The content of the aprotic polar solvent is preferably 1.0% by mass or more and 50.0% by mass or less for the entire solvent. The content of the aprotic polar solvent is that for the entire solvent, if the content is less than 1.0% by mass, the optical characteristics of the transparent conductive film are reduced, and when it exceeds 50.0% by mass, the moisture and heat resistance of the transparent conductive film is reduced.

The content of the solvent is not particularly limited, but may be 50.0% by mass or more and 99.5% by mass or less for the entire coating composition. The solvent system may include a non-polar solvent.

The coating composition can be produced by appropriately mixing a conductive polymer, a silane compound, an inorganic acid, a surface conditioner, an aqueous solvent, and the like by a generally known method. For example, each component is mechanically processed by a ball mill, a sand mill, a hand mill, a paint conditioner, or the like, or a ultrasonic disperser, a homogenizer, a disperser, or a jet mill. Machines can be mixed and dispersed without media treatment.

The order of adding the components is not particularly limited. For example, a silane compound and an inorganic acid may be added to a solution composed of a conductive polymer and a solvent, and a conductive polymer and a solvent may be separately prepared. The resulting solution and the solution consisting of a silane compound, an inorganic acid, and a solvent are mixed with each other.

The solid content concentration of the coating composition is preferably 3% by weight or less based on the entire coating composition. When the solid content concentration of the coating composition exceeds 3% by weight based on the entire coating composition, the viscosity of the coating composition becomes high, and coating by the spray coating method becomes difficult, and as a result, it becomes difficult to form Transparent conductive film with excellent film thickness uniformity. The solid content concentration of the coating composition is based on the entire coating composition, and is more preferably 2.5% by weight or less. The solid content of the coating composition is called a non-volatile component. The solid content of the coating composition typically includes a conductive polymer, a silane compound, an acid catalyst, an antioxidant, and a surface conditioner.

The viscosity of the coating composition is preferably 20 cps or less. When the viscosity of the coating composition exceeds 20 cps, the coating by the spray coating method becomes difficult, and as a result, it becomes difficult to form a transparent conductive film having excellent uniformity in film thickness. The viscosity of the coating composition is more preferably 15 cps or less, and even more preferably 10 cps or less.

The storage stability of the coating composition is that the coating composition is stored at room temperature after manufacturing, and the coating film characteristics (for example, surface resistance, haze, transmittance, or pencil hardness) of the transparent conductive film are significant. The change is determined by using the time during which the coating composition has been stored as an index. The storage time of the coating composition which has reached a significant change in the coating film characteristics of the transparent conductive film is preferably 8 hours or more, more preferably 12 hours or more.

<Formation of transparent conductive film> The conductive film of the present invention is formed by applying the coating composition of the present invention to a transparent substrate to form a coating film, and drying and curing the coating film.

As a coating method of the coating composition, for example, a bar coating method, a reverse method, a gravure coating method, a micro gravure coating method, a mold coating method, a dipping method, a spin coating method, or a slit coating method can be used. And spray coating methods are generally known coating methods. The coating method of the coating composition is preferably a spray coating method. This reason is because the spray coating method can be used to form a coating film with a uniform film thickness even if the thickness of the substrate is not affected, and the film thickness of the coating film can be controlled to the end of the substrate. The substrate can also be easily handled.

The coating composition of the present invention is applied by a spray coating method but has a suitable viscosity. Moreover, the coating composition system of this invention has the outstanding storage stability. Therefore, after filling in the spray coater, the viscosity suitable for coating is maintained after the time when the coating is completed, and a coating film having a uniform film thickness can be formed on the entire surface of the substrate.

After the coating composition is spray-coated on the main surface of the substrate, the solvent is removed by heating to dehydrate and condense the silane compound to form a film. If necessary, the coating film may be irradiated with UV light or EB light to harden the coating film. A coating film formed by using the coating composition and spray coating method of the present invention to form a film by drying and curing the coating film can be referred to as a conductive spray coating. The conductive spray film has a uniform film thickness without being affected even if the thickness of the substrate is not changed, and has a film with a uniform film thickness up to the end of the substrate.

The heating after coating is only required if the solvent component of the coating composition is evaporated, and it is preferably performed at 100 to 150 ° C for 5 to 60 minutes. By heating, the silane compound becomes a particulate inorganic adhesive containing polysiloxane by hydrolysis and dehydration condensation reaction. A conductive polymer is arranged between the particles of the inorganic adhesive, and the transparent conductive film is arranged. A three-dimensional conductive path is formed among them. The heating method can be performed by, for example, a hot air drying method, a heating drying method, a vacuum drying method, or a natural drying method. In addition, a transparent conductive film may be formed by irradiating UV light or EB light to the coating film and curing the coating film as necessary.

Hereinafter, the present invention will be described in detail using examples. However, the present invention is not limited to the following examples. Unless otherwise specified, "parts" and "%" are the quality standards in the following. [Example]

<Production of a coating composition for forming a transparent conductive film> (1) The following components were prepared and mixed in an amount of the composition shown in Table 1 to produce a coating composition for forming a transparent conductive film. (1) Conductive polymer dispersion (trade name, "Clevios PH1000", manufactured by Heraeus), conductive polymer: PEDOT / PSS, solid content concentration: 1.12% by mass, solvent: water) (2) Silane compound: alkane Oxysilane (Made by Shin-Etsu Chemical Industry Co., Ltd., trade names "X-40-2308", "KR-220LP", "KR-500") (3) Aprotic polar solvent (dimethyl sulfonium) (4) Acid catalyst (phosphoric acid) (5) Antioxidant (hydroquinone) (6) Surface conditioner (polysiloxane series) (7) Water (8) Protonic polar solvent (ethyl alcohol)

<Storage stability> (1) The manufactured coating composition is stored at room temperature for a predetermined time. The stored coating composition was coated on the surface of an alkali-free glass substrate, and dried to form a film in an air environment at 120 ° C, and the coating film characteristics (surface resistance, haze, transmittance, and pencil hardness) were measured. Regarding each coating composition, the storage time in which any one of the coating film characteristics changed significantly was determined. The coating composition system whose storage time is within 8 hours was evaluated as ☓ for storage stability, 8 was evaluated for 8 to 12 hours, and ◯ was evaluated for 12 hours or more. The results are shown in Table 1.

＜ Production of transparent conductive film ＞ Using an alkali-free glass (total light transmittance: 91.2%) with a thickness of 0.7 mm and a thickness of 10 cm square is used as a substrate. The entire surface of one side of the substrate is coated by the spray coating method. The transparent conductive film-forming coating liquid is applied to form a coating film. For the spray coater, a spray gun (vortex nozzle, caliber: 1.0 mm) manufactured by Nordson was used. The coating conditions are set as follows. That is, the spray gun speed is 10 to 1500 mm / sec, the coating interval is 2 to 30 mm, the gun height is 1 to 20 cm, and the atomizing pressure is 0.01 to 0.5 MPa. Then, it heated at 120 degreeC for 1 hour. Thereby, a transparent conductive sheet in which a transparent conductive film film is formed on one surface is produced.

Next, each of the evaluations described below was performed on the transparent conductive film. The composition and evaluation results of the transparent conductive film are shown in Table 2.

<Surface resistance> 表面 The surface resistance value (Ω / □) of the transparent conductive film is measured using a resistivity measuring device "Loresta-GP" (MCP-T610 type) manufactured by Mitsubishi Chemical Analytech and an LSP probe.

<Film thickness> 膜 The film thickness (μm) of the transparent conductive film is obtained by cutting the conductive film together with the glass substrate, observing the cross section with a scanning electron microscope (SEM, "S-4500" by Hitachi, Ltd.), and measuring the film thickness. .

<Haze> 雾 The haze (%) of the transparent conductive film is measured using a haze meter "NDH2000" manufactured by Nippon Denshoku Industries.

<Total light transmittance> The total light transmittance (%) of a transparent conductive film is measured using a spectrophotometer "V-570" manufactured by Japan Spectroscopy Corporation.

<Pencil hardness> 铅笔 The pencil hardness of the transparent conductive film is measured according to the pencil hardness measurement method specified in Japanese Industrial Standards (JIS) K5400 using a surface property testing machine "HEIDON-14DR" manufactured by Shinto Scientific.

<Damp and heat resistance> First, the initial surface resistance value of the transparent conductive film was measured in the same manner as the aforementioned evaluation of the electrical characteristics. Next, the transparent conductive sheet was placed in a constant temperature and humidity tank and stored at a temperature of 85 ° C. and a relative humidity of 85% for 240 hours. Next, the surface resistance value of the transparent conductive film of the stored transparent conductive sheet was measured in the same manner as described above. Finally, the degree of change in the surface resistance value was calculated by the following formula (1).

Surface resistance value change rate (%) = (surface resistance value after storage-initial surface resistance value) / initial surface resistance value (1)

<Weather resistance> First, the initial surface resistance value of the transparent conductive film was measured in the same manner as the aforementioned evaluation of the electrical characteristics. Next, the transparent conductive sheet was placed in a weather meter and stored at a radiation intensity of 60 W / m ² (wavelength: 300 to 400 nm) for 120 hours. Next, the surface resistance value of the transparent conductive film of the stored transparent conductive sheet was measured in the same manner as described above. Finally, the change rate of the surface resistance value was calculated by the above-mentioned formula (1).

Claims (9)

A transparent conductive film comprising a conductive polymer containing a polythiophene compound / polystyrene sulfonic acid, an inorganic adhesive containing a silane compound, an inorganic acid, and a surface modifier, and is formed on one of the transparent substrates. This aspect is characterized in that the inorganic acid is contained in an amount of 30% by mass or less based on the content of the conductive polymer as a reference. The transparent conductive film according to claim 1, wherein the content of the conductive polymer is used as a reference in an amount of 10% by mass or less, and further includes an antioxidant. The transparent conductive film according to claim 1 or 2, wherein the inorganic acid is at least one selected from the group consisting of phosphoric acid, hydrochloric acid, and sulfuric acid. The transparent conductive film according to claim 2 or 3, wherein the antioxidant is a quinone compound. The transparent conductive film according to any one of claims 1 to 4, wherein the conductive polymer is contained in an amount of 1 to 75% by mass based on the total amount of the conductive polymer and the inorganic adhesive. A coating composition comprising a conductive polymer including a polythiophene compound / polystyrene sulfonic acid, a silane compound, an inorganic acid, a surface modifier, and an aqueous solvent, characterized in that: the inorganic acid is conductive The polymer content is included as an amount in an amount of 30% by mass or less. The coating composition according to claim 6, wherein the content of the conductive polymer is used as a reference in an amount of 10% by mass or less, and further includes an antioxidant. A method for manufacturing a transparent conductive film, comprising applying a coating composition of claim 6 or 7 to one surface of a transparent substrate to form a coating film, and drying and curing the coating film to form a film. A step of. The manufacturing method of the transparent conductive film of Claim 8 whose said coating is performed using the spray coating method.