JP2007126526A - Transparent electroconductive coating material and transparent electroconductive film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transparent electroconductive coating material capable of providing a transparent electroconductive film not only having excellent electroconductivity but also having organic solvent resistance; and to provide the transparent electroconductive film. <P>SOLUTION: The transparent electroconductive coating material contains an electroconductive oxide granular powder having 1-100 nm average particle diameter and dispersed in a solvent containing a binder. The binder consists essentially of a crosslinkable resin and a curing agent, and the crosslinkable resin before crosslinking has ≥80°C, preferably ≥100°C glass transition temperature (Tg). An acrylic polyol resin is preferable as the crosslinkable resin, and a blocked isocyanate is preferable as the curing agent. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a transparent conductive coating applied to various display devices such as liquid crystal displays (LCD), transparent electrodes such as touch panels and electronic papers, and in particular, excellent organic solvent resistance as well as excellent transparency and conductivity. It is related with the transparent conductive film suitable for formation of the transparent conductive film which has, and the transparent conductive film obtained from the transparent conductive paint.

  Conventionally, for transparent electrodes of various display devices such as LCDs, indium tin oxide (hereinafter, also referred to as ITO) transparent conductive material formed by using a physical film forming method typified by sputtering or ion plating. Membranes have been used. Among these, a transparent conductive film obtained by sputtering (hereinafter abbreviated as a sputtering ITO film) is most widely used.

  However, with the recent increase in the size of displays, there are problems such as an increase in capital investment cost for producing a sputtering ITO film and a low utilization efficiency of an ITO film material from the viewpoint of resource saving. That is, in order to form a sputtering ITO film on a large-area substrate, a large capital investment is required to make the large space into a high vacuum. Moreover, only about 10 to 20% of the sputtering target material is used for an actual transparent conductive film, and about 70% is used for recovery of indium as scrap.

  Therefore, research has been conducted to form a transparent conductive film using a coating method that does not require expensive equipment. The coating method is a method of coating a base material with a coating liquid (transparent conductive paint) containing conductive oxide powder (filler) mainly composed of indium oxide, tin oxide, zinc oxide and the like and a resin binder, and drying, A transparent conductive film is formed through a curing process. Since a vacuum is not required, there is an advantage that the capital investment cost can be greatly suppressed as compared with the case of producing a sputtering ITO film. Further, since it is sufficient to apply (print) the coating liquid only to the necessary portions, the use efficiency of the transparent conductive material is high, and it is also a resource-saving and material-saving method.

  However, the transparent conductive film obtained by the conventional coating method has a problem that the resistance value of the film is high. In general, when applied to transparent electrodes such as various display devices, touch panels, and electronic paper, the specific resistance of the film is required to be 1.0 Ω · cm or less, and this specific resistance must be satisfied. It was difficult. Further, since a thermoplastic resin binder such as an acrylic resin is usually used as the binder, there is a problem that the transparent conductive film has poor organic solvent resistance.

For example, Japanese Patent Application Laid-Open No. 9-109259 (Patent Document 1) discloses a method for producing a conductive layer by applying and drying a paint composed of conductive fine particles and a resin binder, and further applying pressure. However, the surface resistance of the obtained conductive film is as high as about 10 ⁶ Ω / □ at a film thickness of 2 μm, and cannot be used as transparent electrodes for various display devices, touch panels, electronic papers and the like.

  Moreover, in order to obtain a low-resistance film by coating with a paint containing conductive oxide powder, for example, as shown in Japanese Patent Application Laid-Open No. 2001-328195 (Patent Document 2), the conductive oxide powder is coated with a metal roll. There is a method to compress by sandwiching. According to this publication, a resistance value of 2 kΩ / □ is realized with a film thickness of 0.5 μm. However, in order to further increase the area, it is necessary to enlarge the metal roll. In addition, in this case, since the total pressure increases, there are technical problems such as non-uniform pressure due to deflection and the like, and there are problems such as an excessively large facility for securing the rigidity of the roll.

  Furthermore, Japanese Patent Application Laid-Open No. 8-199096 (Patent Document 3) discloses a method in which a coating material containing ITO powder is applied to a glass substrate and baked at a high temperature of 300 ° C. or higher. However, when plastic is used as the substrate, a temperature of 300 ° C. cannot be applied. For example, when using a suitable PET film as a substrate due to problems such as transparency, resistance to organic solvents, handling, and cost, the temperature that can be applied is limited to 150 ° C, so this method cannot be applied. It is.

  Further, as described above, the transparent conductive film needs to have organic solvent resistance in the process of manufacturing various devices. For example, in a manufacturing process of an organic electroluminescence element or electronic paper which is a next generation display device, it is necessary to stack various functional films on a transparent conductive film. However, when various functional films are formed on the transparent conductive film by a coating method, if the transparent conductive film does not have organic solvent resistance, the functional film-forming coating cannot be applied thereon. The device cannot be manufactured.

JP-A-9-109259 JP 2001-328195 A JP-A-8-199096

  In view of such a conventional situation, the present invention is excellent in transparency and conductivity while forming a transparent conductive film useful as a transparent electrode for various display devices such as an LCD by a coating method. It aims at providing the transparent conductive film which can form the transparent conductive film which also has organic solvent property at the low temperature of 150 degrees C or less, and the transparent conductive film formed using this transparent conductive paint.

  As a result of various studies conducted by the inventors to obtain a transparent conductive film having excellent conductivity and organic solvent resistance by a method of forming a transparent conductive film using a transparent conductive paint containing conductive oxide granular powder. The present inventors have found that it is effective to use a crosslinkable resin having a glass transition point of 80 ° C. or higher before crosslinking as a binder of a transparent conductive coating material, and have made the present invention.

  That is, to achieve the above object, the transparent conductive paint provided by the present invention is a transparent conductive paint in which conductive oxide granular powder having an average particle diameter of 1 to 100 nm is dispersed in a solvent containing a binder, The binder is mainly composed of a crosslinkable resin and a curing agent, and the glass transition point (Tg) of the crosslinkable resin before crosslinking is 80 ° C. or higher, preferably 100 ° C. or higher.

  In the transparent conductive paint of the present invention, the crosslinkable resin is preferably an acrylic polyol resin. Moreover, it is preferable that the said hardening | curing agent is block isocyanate.

  In the transparent conductive paint of the present invention, the conductive oxide granular powder preferably contains at least one of indium oxide, tin oxide, and zinc oxide as a main component. The conductive oxide granular powder preferably contains indium-tin oxide fine particles as a main component. Furthermore, the weight ratio of the conductive oxide particulate powder: binder is preferably 75:25 to 90:10.

  The present invention is also a transparent conductive film formed using the transparent conductive paint of the present invention, comprising conductive oxide granular powder dispersed in a crosslinked and cured resin, and having a specific resistance of 1 for the film. The present invention provides a transparent conductive film characterized by being 0.0Ω · cm or less.

  According to the present invention, there is provided a transparent conductive paint capable of forming a transparent conductive film having high transparency, excellent conductivity, and organic solvent resistance at a low temperature of 150 ° C. or less by a simple and inexpensive coating method. Can be provided. In addition, since the transparent conductive film formed by the transparent conductive paint of the present invention has resistance to organic solvents, it is difficult to be attacked by organic solvents when various functional films are formed thereon by a coating method. And deterioration of film characteristics such as resistance value can be prevented. Therefore, the transparent conductive film of the present invention can be suitably used as various display devices such as a liquid crystal display, transparent electrodes such as a touch panel and electronic paper.

  The transparent conductive paint of the present invention contains conductive oxide granular powder having an average particle diameter of 1 to 100 nm and a binder, and a resin binder mainly composed of a crosslinkable resin and a curing agent is used as the binder. This resin binder component bonds the fine particles of the conductive oxide granular powder to increase the conductivity and strength of the transparent conductive film, and also increases the adhesion between the substrate and the transparent conductive film. In addition, since the crosslinkable resin is cured by crosslinking, the organic solvent resistance of the transparent conductive film is improved. Therefore, even when another functional film is formed on the transparent conductive film, the transparent resin is transparent by the organic solvent in the coating solution Degradation of the conductive film can be prevented. Furthermore, in order to obtain a transparent conductive film having excellent conductivity, the crosslinkable resin must have a crow transition point (Tg) before crosslinking of 80 ° C. or higher, and more preferably 100 ° C. or higher. preferable.

  The reason why an excellent conductive transparent conductive film can be obtained when the glass transition point of the crosslinkable resin before crosslinking is 80 ° C. or higher is not clear, but can be considered as follows, for example. The crosslinkable resin softens when the glass transition point is exceeded, but when the glass transition point is high, it can give a stronger stress to the conductive oxide granular powder during the drying process of the coating film, and the fine particles contact each other. It is presumed to have an effect of strengthening. Therefore, if the resin binder is crosslinked after drying, a transparent conductive film excellent in organic solvent resistance can be obtained. On the other hand, when the glass transition point of the crosslinkable resin is low, the contact between the fine particles in the drying process is not strengthened, so even if the glass transition point finally increases due to crosslinking after drying, the resistance value of the film The effect of improvement is considered to be poor. In short, it is important that the glass transition point before crosslinking is 80 ° C. or higher, not the final glass transition point of the crosslinkable resin.

  The crosslinkable resin used as the binder of the transparent conductive paint may be any resin that crosslinks and cures by reacting with a curing agent and has a high glass transition point of 80 ° C. or higher before crosslinking. The resin can be appropriately selected from a functional resin, a room temperature curable resin, and the like. For example, an epoxy resin can be used as the thermosetting resin, and a two-component epoxy resin, a urethane resin, an acrylic polyol resin, or the like can be used as the room temperature curable resin. Among them, an acrylic polyol resin as a crosslinkable resin having a hydroxyl group (—OH) is particularly preferable in that a resin having both a high glass transition point and excellent crosslinkability is easily obtained. In addition to the above, an ultraviolet curable resin, an electron beam curable resin, or the like may be used.

  In addition, as the curing agent for the crosslinkable resin, an amino resin having an amino group or a methylol group capable of crosslinking with a hydroxyl group, or a polyisocyanate is used. Here, for polyisocyanate, depending on the starting isocyanate used, TDI (tolylene diisocyanate), MDI (diphenylmethane diisocyanate), XDI (xylylene diisocyanate), NDI (naphthylene 1,5-diisocyanate), TMXDI (tetra) Aromatic isocyanates such as methylene xylylene diisocyanate), IPDI (isophorone diisocyanate), H12MDI (hydrogenated MDI, dicyclohexylmethane diisocyanate), H6XDI (hydrogenated XDI), and other alicyclic isocyanates, HDI (hexa) Examples include aliphatic isocyanates such as methylene diisocyanate), DDI (dimer acid diisocyanate), and NBDI (norbornene diisocyanate).

  Among these curing agents, aromatic isocyanates such as TDI and MDI are generally easily yellowed by ultraviolet rays, but IPDI and HDI alicyclic isocyanates and aliphatic isocyanates are difficult to yellow. preferable. In addition, in the isocyanate curing agent, the blocked isocyanate, in which polyisocyanate is protected with a blocking agent, suppresses the crosslinking reaction at low temperatures, so it is not a two-component type in which the curing agent is mixed before use. Therefore, it is more preferable in terms of handling properties and storage stability of the transparent conductive paint.

  Among the above-mentioned blocked isocyanates, aliphatic blocked isocyanates are preferable because they do not turn yellow, and the minimum curing temperature (the temperature at which the protective agent of the blocking agent is reduced and functions effectively as a curing agent) is preferably 130 ° C. or less. Is preferably 100 ° C. or lower. This is because if the minimum curing temperature exceeds 130 ° C., the choice of usable base materials is narrowed. For example, when PET suitable as a substrate is used, the temperature that can be applied to PET is 150 ° C., preferably 130 ° C. or less. Examples of the curing agent that satisfies such conditions include Duranate MF-K60X (HDI block isocyanate, minimum curing temperature 90 ° C.) manufactured by Asahi Kasei Corporation. Here, the ratio (molar ratio) of the hydroxyl group (—OH) of the crosslinkable resin having a hydroxyl group to the isocyanate group (—NCO) of the polyisocyanate is considered in consideration of characteristics such as solvent resistance and strength of the crosslinked resin. In general, NCO / OH = 1 to 5 is preferable. More preferably, it is set in the range of 1 to 3.

  In addition to the above-described curing agent, an existing curing catalyst (dibutyltin dilaurate or the like) can be used in combination as necessary. Depending on the type of curing agent, the curing rate of the crosslinkable resin can be significantly increased by using a curing catalyst in combination.

  As the conductive oxide granular powder applied to the transparent conductive coating material of the present invention, a powder containing one or more of indium oxide, tin oxide and zinc oxide as a main component is preferable. For example, indium tin oxide (ITO), indium zinc oxide (IZO), indium-tungsten oxide (IWO), indium-titanium oxide (ITiO), indium zirconium oxide, tin antimony oxide (ATO), fluorine Examples thereof include tin oxide (FTO), aluminum zinc oxide (AZO), and gallium zinc oxide (GZO). Among these, ITO is particularly preferable because it has the highest characteristics.

  The average particle size of the conductive oxide granular powder needs to be 1 to 100 nm, and more preferably 5 to 50 nm. When the average particle size is less than 1 nm, it is difficult to produce a transparent conductive paint, and the resistance value of the obtained transparent conductive film increases. On the other hand, when the average particle diameter exceeds 100 nm, the conductive oxide granular powder easily settles in the transparent conductive paint, making it difficult to handle and simultaneously achieving high transmittance and low resistance in the transparent conductive film. Because it becomes difficult to do.

  Further, the particle shape of the conductive oxide granular powder needs to be granular. Here, granular means granular particles including spherical or regular polyhedrons, excluding particles having a clear shape anisotropy such as needles and flakes. The reason why the granular powder is used in the present invention is that the granular particles are easily densely packed in the film, and the densely packed film has less visible light scattering and excellent transparency. On the other hand, when shape anisotropic particles such as needles or flakes are used, the scattering of visible light is increased, and a translucent film having a high haze value (cloudiness) is obtained. The scope of application is greatly limited. In addition, evaluation of the average particle diameter and particle shape of conductive oxide granular powder is based on the observation result in a transmission electron microscope (TEM).

  The ratio of the conductive oxide granular powder and the binder (crosslinkable resin + curing agent) in the transparent conductive coating is preferably 75:25 to 90:10 in terms of the weight ratio of the conductive oxide granular powder to the binder, and 80:20. ~ 85: 15 is more preferred. When the ratio of the binder is more than 75:25 in terms of the conductive oxide granular powder: binder weight ratio, the resistance of the obtained transparent conductive film may be too high. On the other hand, when the binder ratio is less than 90:10 in terms of the conductive oxide granular powder: binder weight ratio, the strength of the transparent conductive film is lowered and at the same time sufficient adhesion with the substrate cannot be obtained. In addition, in the volume ratio of conductive oxide granular powder: binder, 34:66 to 61:39 is preferable, and 41:59 to 49:51 is more preferable.

  Examples of the solvent used for the transparent conductive paint include water, methanol (MA), ethanol (EA), 1-propanol (NPA), isopropanol (IPA), butanol, pentanol, benzyl alcohol, diacetone alcohol (DAA), and the like. Alcohol solvents, acetone, methyl ethyl ketone (MEK), methyl propyl ketone, methyl isobutyl ketone (MIBK), ketone solvents such as cyclohexanone and isophorone, ester solvents such as ethyl acetate, butyl acetate and methyl lactate, ethylene glycol monomethyl ether (MCS), ethylene glycol monoethyl ether (ECS), ethylene glycol isopropyl ether (IPC), ethylene glycol monobutyl ether (BCS), ethylene glycol monoethyl ether Acetate, ethylene glycol monobutyl ether acetate, propylene glycol methyl ether (PGM), propylene glycol ethyl ether (PE), propylene glycol methyl ether acetate (PGM-AC), propylene glycol ethyl ether acetate (PE-AC), diethylene glycol monomethyl ether, Diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, dipropylene Glycol derivatives such as polyglycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monobutyl ether, benzene derivatives such as toluene, xylene, mesitylene, dodecylbenzene, formamide (FA), N-methylformamide, dimethylformamide (DMF) , Dimethylacetamide, dimethyl sulfoxide (DMSO), N-methyl-2-pyrrolidone (NMP), γ-butyrolactone, ethylene glycol, diethylene glycol, tetrahydrofuran (THF), chloroform, etc., but are not limited thereto is not.

  In addition, the solvent used for the transparent conductive paint can be appropriately selected in consideration of the solubility in the plastic substrate to be used and the film forming conditions. For example, in the case of screen printing, considering the evaporation rate, the solubility of the printing plate in the emulsion or binder resin, and harmfulness, examples of preferred solvents include isophorone, cyclohexanone, and γ-butyrolactone.

  In the transparent conductive paint of the present invention, the conductive oxide granular powder is mixed with a binder (consisting of the above-mentioned crosslinkable resin and a curing agent) and a solvent, and if necessary, a dispersant is added to perform a dispersion treatment. Can be manufactured. For example, the conductive oxide granular powder is mixed with a solvent and a dispersant as necessary, and after dispersion treatment, a binder is added to the obtained dispersion, and the conductive oxide granular powder concentration, solvent composition, etc. Adjust the ingredients. In addition, there is no restriction | limiting in particular in the addition time of a binder, You may add beforehand to the solvent before dispersion | distribution of electroconductive oxide granular powder besides adding to electroconductive oxide granular powder dispersion liquid as mentioned above. In addition, a general-purpose method such as ultrasonic treatment, a homogenizer, a paint shaker, a bead mill, or a three roll mill can be applied to the dispersion treatment.

  Examples of the dispersant include various coupling agents such as a silicone coupling agent, various polymer dispersants, and various surfactants such as anionic, nonionic, and cationic types. These dispersants can be appropriately selected according to the type of conductive oxide granular powder used and the dispersion treatment method. Even if no dispersant is used, a good dispersion state may be obtained depending on the combination of the conductive oxide granular powder and the solvent and the dispersion treatment method. In addition, since the use of a dispersant may deteriorate the resistance value and weather resistance of the film, a transparent conductive paint that does not use a dispersant is most preferable.

  The transparent conductive film of the present invention can be formed by printing and applying the transparent conductive paint on a substrate, and then heating and reacting a crosslinkable resin of a binder with a curing agent to cause crosslinking and curing. Screen printing, gravure printing, ink jet printing, dispensing, wire bar coating, doctor blade coating, roll coating, and the like can be used for printing the transparent conductive paint on the substrate.

  As said base material, what is necessary is just to have transparency, and glass and various transparent plastics can be used. As the plastic, for example, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), nylon, polyethersulfone (PES), triacetyl cellulose, norbornene resin, acrylic resin, polycarbonate, or the like can be used. PET is a preferable material as a base material from the viewpoints of being inexpensive, excellent in strength, having both transparency and flexibility. When plastic is used for the base material, an easy adhesion treatment for increasing the adhesion to the transparent conductive film, specifically, a plasma treatment, a corona discharge treatment, a short wavelength ultraviolet irradiation treatment, etc. It can also be left.

  The transparent conductive film of the present invention thus obtained not only has both high transparency and conductivity, but also has excellent organic solvent resistance because the crosslinkable resin of the binder is crosslinked and cured. Therefore, when applied to various display devices such as LCDs, transparent electrodes such as touch panels and electronic paper, organic solvents in the coating liquid for layer formation in the layer printing process of each layer for further element formation thereon It is possible to prevent deterioration of film characteristics such as resistance value. The specific resistance of the transparent conductive film is preferably 1.0 Ω · cm or less. This is because when the specific resistance of the transparent conductive film exceeds 1.0 Ω · cm, it is difficult to achieve both transparency and conductivity required for the transparent conductive film.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples. Further, in the following description, “%” and “part” indicate “% by weight” and “part by weight”, excluding% of transmittance and haze value.

  Further, the organic solvent resistance of the transparent conductive film was evaluated by rubbing the film 10 times with a cotton swab soaked with acetone 10 times, and visually observing the state of the film. The transmittance (visible light) and haze value of the transparent conductive film were measured using a haze meter (HR-200) manufactured by Murakami Color Research Laboratory. The surface resistance of the transparent conductive film was measured using a surface resistance meter Loresta AP (MCP-T400) manufactured by Mitsubishi Chemical Corporation.

[Example 1]
As the conductive oxide granular powder, an ITO granular powder having an average particle size of 0.03 μm (SUFP-HX, manufactured by Sumitomo Metal Mining Co., Ltd.) was used. As a crosslinkable resin for the binder, an acrylic polyol resin solution (manufactured by Mitsubishi Rayon Co., Ltd., GS-5756, hydroxyl value 29 KOHmg / g [resin component]) having a glass transition point (Tg) of 102 ° C. is used as a curing agent. Isocyanate (manufactured by Asahi Kasei Corporation, MF-K60X, solid content (curing agent component) of about 60%) was used. Moreover, isophorone was used as a solvent.

  The ITO granular powder was dispersed in isophorone containing 8.6 parts of the acrylic polyol resin solution (resin concentration 40%) in which the solvent was replaced with isophorone and 1.2 parts of blocked isocyanate to prepare a transparent conductive paint. The composition of this transparent conductive paint is ITO: 55.2%, acrylic polyol resin: 8.1%, blocked isocyanate (curing agent component): 1.7%, isophorone: 35%, ITO granular powder: binder The weight ratio was 84.9: 15.1, and NCO (isocyanate group) / OH (hydroxyl group) = 1/1.

  The transparent conductive paint is applied on a PET substrate (Tetron HSL, manufactured by Teijin Ltd.) as a base material with a wire bar having a wire diameter of 0.15 mm, dried at 40 ° C. for 15 minutes, and further at 120 ° C. for 20 minutes. The binder was crosslinked and cured by heating for 2 minutes to form a transparent conductive film having a thickness of 2 μm.

  The obtained transparent conductive film was not damaged at all even when lightly rubbed 10 times with a cotton swab dipped in acetone. The film characteristics of the transparent conductive film were a visible light transmittance of 86.1%, a haze value of 4.5%, a surface resistance value of 850 Ω / □, and a specific resistance value of 0.17 Ω · cm. The visible light transmittance and the haze value described above are values only for the transparent conductive film, and are obtained by the following formulas.

Transmissivity of transparent conductive film (%) = (Transmittance of substrate with transparent conductive film) / (Transmittance of substrate) × 100
Haze value of transparent conductive film (%) = (Haze value of substrate with transparent conductive film) − (Haze value of substrate)

[Comparative Example 1]
A transparent conductive paint was obtained in the same manner as in Example 1 except that an acrylic polyol resin solution (hydroxyl value 108 KOHmg / g [resin component]) having a glass transition point (Tg) of 32 ° C. was used as the crosslinkable resin. . The composition of this transparent conductive paint is: ITO: 55.2%, acrylic polyol resin: 5.6%, blocked isocyanate (curing agent component): 4.2%, isophorone: 35%, ITO granular powder: binder The weight ratio was 84.9: 15.1, and NCO (isocyanate group) / OH (hydroxyl group) = 1/1.

  Using this transparent conductive paint, a transparent conductive film was formed on the substrate in the same manner as in Example 1. The obtained transparent conductive film was not damaged at all even when the surface was lightly rubbed 10 times with a cotton swab dipped in acetone. The film characteristics of the transparent conductive film were a visible light transmittance of 85.1%, a haze value of 4.6%, a surface resistance value of 13 kΩ / □, and a specific resistance of 2.6 Ω · cm. It can be seen that the transparent conductive film of Comparative Example 1 is excellent in organic solvent resistance as compared with Example 1, but has a specific resistance higher than 1.0 Ω · cm and inferior in conductivity.

[Comparative Example 2]
Transparent conductive coating material in which the binder has no crosslinkability in the same manner as in Example 1 except that the acrylic polyol resin (Tg: 102 ° C.) of Example 1 was used as the binder resin and no curing agent was added. Got. The composition of this transparent conductive paint is ITO: 55.2%, acrylic polyol resin: 9.8%, isophorone: 35%, and the weight ratio of ITO granular powder: binder is 84.9: 15.1. (Isocyanate group) / OH (hydroxyl group) = 0/1.

Using this transparent conductive paint, a transparent conductive film was formed on the substrate in the same manner as in Example 1. When the obtained transparent conductive film was lightly rubbed 10 times with a cotton swab dipped in acetone, it was markedly damaged. The film characteristics of the transparent conductive film were a visible light transmittance of 86.2%, a haze value of 4.4%, a surface resistance value of 1250Ω / □, and a specific resistance of 0.25Ω · cm. It can be seen that the transparent conductive film of Comparative Example 2 has almost the same resistance value and transmittance as compared to Example 1, but is inferior in organic solvent resistance.

Claims (8)

  A transparent conductive paint in which conductive oxide granular powder having an average particle size of 1 to 100 nm is dispersed in a solvent containing a binder, the binder mainly comprising a crosslinkable resin and a curing agent, and crosslinkability before crosslinking A transparent conductive paint, wherein the glass transition point (Tg) of the resin is 80 ° C. or higher.   The transparent conductive paint according to claim 1, wherein a glass transition point (Tg) of the crosslinkable resin is 100 ° C. or more.   The transparent conductive paint according to claim 1, wherein the crosslinkable resin is an acrylic polyol resin.   The transparent conductive paint according to claim 1, wherein the curing agent is a blocked isocyanate.   The transparent conductive paint according to claim 1, wherein the conductive oxide granular powder contains at least one of indium oxide, tin oxide, and zinc oxide as a main component.   The transparent conductive paint according to any one of claims 1 to 4, wherein the conductive oxide granular powder is mainly composed of indium-tin oxide fine particles.   The transparent conductive paint according to claim 1, wherein the conductive oxide granular powder: binder weight ratio is 75:25 to 90:10. A transparent conductive film formed using the transparent conductive paint according to claim 1, comprising conductive oxide granular powder dispersed in a crosslinked and cured resin, wherein the specific resistance of the film is 1 A transparent conductive film characterized by having a resistance of 0.0Ω · cm or less.