Transparent Conductive Film

Abstract

To provide a transparent electroconductive film that is provided with an electroconductive layer containing metal nanowires, and is excellent in humidification reliability.SOLUTION: A transparent electroconductive film is provided with a transparent base material and a transparent electroconductive layer disposed on at least one side of the transparent base material. The transparent electroconductive layer contains metal nanowires and a polymer matrix. The polymer matrix contains a thiol-based compound. In one embodiment, the thiol-based compound has a dithiolane skeleton.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a transparent conductive film. [Background technology]

[0002] Conventionally, transparent conductive films that have a metal oxide layer, such as an indium-tin composite oxide layer (ITO layer), formed on a transparent resin film have been widely used as transparent conductive films for electrodes in touch sensors, etc. However, transparent conductive films with a metal oxide layer formed on them have insufficient flexibility, making them difficult to use in applications that require flexibility, such as flexible displays.

[0003] Transparent conductive films with a conductive layer containing metal nanowires have been proposed as transparent conductive films with excellent flexibility. However, such transparent conductive films suffer from the problem of increased resistance due to deterioration of the metal nanowires under high humidity conditions. One possible solution to this problem is to protect the conductive layer composed of metal nanowires with a polymer matrix. However, even with this technology, it is difficult to fully prevent deterioration of the metal nanowires. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2009-505358 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been made to solve the above-mentioned problems, and its object is to provide a transparent conductive film having a conductive layer containing metal nanowires and having excellent humidification reliability. [Means for solving the problem]

[0006] The transparent conductive film of the present invention comprises a transparent substrate and a transparent conductive layer disposed on at least one side of the transparent substrate, the transparent conductive layer containing metal nanowires and a polymer matrix, and the polymer matrix containing a thiol-based compound. In one embodiment, the thiol compound is a thiol compound having a dithiolane skeleton. In one embodiment, the thiol compound is α-lipoic acid. In one embodiment, the content of the thiol compound having a dithiolane skeleton is 0.1 to 5 parts by weight relative to 100 parts by weight of the polymer that constitutes the polymer matrix. In one embodiment, the metal nanowires have a fused network structure. In one embodiment, the transparent conductive layer further contains a silane coupling agent. In one embodiment, the transparent conductive layer has a visible light transmittance of 80% or more. In one embodiment, the transparent conductive layer has a sheet resistivity of 200 Ω / □ or less. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a transparent conductive film that has a conductive layer containing metal nanowires and has excellent humidification reliability. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic cross-sectional view of a transparent conductive film according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] A. Overview of transparent conductive films 1 is a schematic cross-sectional view of a transparent conductive film according to one embodiment of the present invention. The transparent conductive film 100 comprises a transparent substrate 10 and a transparent conductive layer 20 disposed on at least one side of the transparent substrate 10. The transparent conductive layer 20 includes metal nanowires 21 and a polymer matrix 22. Typically, the transparent conductive layer 20 is configured so that the metal nanowires 21 are present in the polymer matrix 22.

[0010] The polymer matrix contains a thiol-based compound. In the present invention, it is believed that the thiol-based compound added to the polymer matrix constituting the transparent conductive layer binds to the metal nanowires in such a way as to form a protective film on the surface, thereby preventing deterioration of the metal nanowires. The transparent conductive film of the present invention, which exhibits such effects, can prevent deterioration of the metal nanowires even under high humidity conditions and maintain favorable conductivity. This effect becomes even more pronounced by appropriately selecting the thiol-based compound, as described below. In the present invention, even though metal nanowires are used as the material constituting the transparent conductive layer, deterioration of the material is prevented, thereby making it possible to obtain a transparent conductive film with excellent flexibility and high environmental durability.

[0011] The thickness of the transparent conductive film is preferably 10 μm to 500 μm, more preferably 15 μm to 300 μm, and even more preferably 20 μm to 200 μm.

[0012] The visible light transmittance of the transparent conductive film is preferably 80% or more, more preferably 85% or more, and particularly preferably 90% or more. Within this range, a transparent conductive film suitable for use as a transparent electrode can be obtained.

[0013] The sheet resistance of the transparent conductive film is preferably 200 Ω / □ or less, more preferably 150 Ω / □ or less, and even more preferably 100 Ω / □ or less. The lower the sheet resistance of the transparent conductive film, the better, but the lower limit is, for example, 1 Ω / □ (preferably 0.5 Ω / □, more preferably 0.1 Ω / □).

[0014] B.Transparent conductive layer As described above, the transparent conductive layer contains metal nanowires and a polymer matrix. By forming a transparent conductive layer containing metal nanowires, a transparent conductive film with excellent flexibility and light transmittance can be obtained. The metal nanowires are protected by the polymer matrix. As a result, corrosion of the metal nanowires is prevented, and a transparent conductive film with excellent durability can be obtained. The polymer matrix contains a thiol-based compound.

[0015] The thickness of the transparent conductive layer is preferably 10 nm to 1000 nm, and more preferably 20 nm to 500 nm.

[0016] The visible light transmittance of the transparent conductive layer is preferably 80% or more, more preferably 85% or more, even more preferably 90% or more, and particularly preferably 95% or more.

[0017] The sheet resistance of the transparent conductive layer is preferably 200 Ω / □ or less, more preferably 150 Ω / □ or less, and even more preferably 100 Ω / □ or less. The lower the sheet resistance of the transparent conductive film, the better, but the lower limit is, for example, 1 Ω / □ (preferably 0.5 Ω / □, more preferably 0.1 Ω / □).

[0018] (metal nanowires) Metal nanowires are conductive materials made of metal, shaped like needles or threads, and nanometer-sized diameters. Metal nanowires may be linear or curved. By using a transparent conductive layer made of metal nanowires, the metal nanowires form a mesh, allowing even a small amount of metal nanowires to form an excellent electrical conduction path, resulting in a transparent conductive film with low electrical resistance. Furthermore, the mesh-like shape of the metal nanowires allows openings to be formed in the gaps between the meshes, resulting in a transparent conductive film with high light transmittance.

[0019] The ratio of the thickness d to the length L of the metal nanowire (aspect ratio: L / d) is preferably 10 to 100,000, more preferably 50 to 100,000, and particularly preferably 100 to 10,000. By using metal nanowires with such a high aspect ratio, the metal nanowires can be well intersected, enabling a small number of metal nanowires to exhibit high conductivity. As a result, a transparent conductive film with high light transmittance can be obtained. In this specification, the "thickness of the metal nanowire" refers to the diameter of the metal nanowire when the cross section is circular, the minor axis of the metal nanowire when the cross section is elliptical, and the longest diagonal line of the metal nanowire when the cross section is polygonal. The thickness and length of the metal nanowire can be confirmed using a scanning electron microscope or a transmission electron microscope.

[0020] The thickness of the metal nanowires is preferably less than 500 nm, more preferably less than 200 nm, particularly preferably 10 to 100 nm, and most preferably 10 to 50 nm. Within this range, a transparent conductive layer with high light transmittance can be formed.

[0021] The length of the metal nanowires is preferably 1 μm to 1000 μm, more preferably 10 μm to 500 μm, and particularly preferably 10 μm to 100 μm. If the length is within this range, a transparent conductive film with high conductivity can be obtained.

[0022] Any suitable metal can be used as the metal constituting the metal nanowires, as long as it is a conductive metal. Examples of metals constituting the metal nanowires include silver, gold, copper, and nickel. Materials obtained by plating these metals (e.g., gold plating) may also be used. Among these, silver, copper, or gold are preferred from the viewpoint of conductivity, and silver is more preferred.

[0023] Any suitable method can be used to produce the metal nanowires. Examples include reducing silver nitrate in solution, applying a voltage or current from the tip of a probe to the surface of a precursor, drawing the metal nanowires from the tip of the probe, and continuously forming the metal nanowires. In the method of reducing silver nitrate in solution, silver nanowires can be synthesized by liquid-phase reduction of a silver salt such as silver nitrate in the presence of a polyol such as ethylene glycol and polyvinylpyrrolidone. Uniformly sized silver nanowires can be mass-produced, for example, according to the methods described in Xia, Y. et al., Chem. Mater. (2002), 14, 4736-4745 and Xia, Y. et al., Nano Letters (2003), 3(7), 955-960.

[0024] The transparent conductive layer containing the metal nanowires can be formed by applying a dispersion of the metal nanowires in a solvent onto the transparent substrate, and then drying the applied layer.

[0025] Examples of the solvent include water, alcohol solvents, ketone solvents, ether solvents, hydrocarbon solvents, aromatic solvents, etc. From the viewpoint of reducing the environmental load, it is preferable to use water.

[0026] The dispersion concentration of the metal nanowires in the metal nanowire dispersion liquid is preferably 0.1% by weight to 1% by weight, within such a range, making it possible to form a transparent conductive layer that is excellent in conductivity and light transmittance.

[0027] The metal nanowire dispersion may further contain any appropriate additive depending on the purpose. Examples of the additive include a corrosion inhibitor that prevents corrosion of the metal nanowires, a surfactant that prevents aggregation of the metal nanowires, etc. The type, number, and amount of the additives used may be appropriately determined depending on the purpose.

[0028] Any appropriate method can be used to apply the metal nanowire dispersion. Examples of the application method include spray coating, bar coating, roll coating, die coating, inkjet coating, screen coating, dip coating, letterpress printing, intaglio printing, and gravure printing. Any appropriate drying method (e.g., natural drying, air drying, and heat drying) can be used to dry the coating layer. For example, in the case of heat drying, the drying temperature is typically 50°C to 200°C, and the drying time is typically 1 minute to 10 minutes.

[0029] The content of the metal nanowires in the transparent conductive layer is preferably 30 to 90% by weight, and more preferably 45 to 80% by weight, based on the total weight of the transparent conductive layer. Within this range, a transparent conductive film with excellent conductivity and light transparency can be obtained.

[0030] When the metal nanowires are silver nanowires, the density of the transparent conductive layer is preferably 1.3 g / cm 3 ~10.5g / cm 3 and more preferably 1.5 g / cm 3 ~3.0g / cm 3 Within this range, a transparent conductive film having excellent conductivity and light transmittance can be obtained.

[0031] In one embodiment, the transparent conductive layer is patterned. Any appropriate method can be adopted as the patterning method depending on the form of the transparent conductive layer. The pattern shape of the transparent conductive layer can be any appropriate shape depending on the application. Examples include the patterns described in JP-T-2011-511357, JP-A-2010-164938, JP-A-2008-310550, JP-T-2003-511799, and JP-T-2010-541109. After the transparent conductive layer is formed on the transparent substrate, it can be patterned using any appropriate method depending on the form of the transparent conductive layer.

[0032] In one embodiment, the metal nanowires in the transparent conductive layer have a fused network structure. The metal nanowires having a fused network structure are in a state where the metal nanowires are fused to each other at their contact points. By forming a transparent conductive layer including metal nanowires having a fused network structure, a transparent conductive film with higher conductivity can be obtained without impairing transparency.

[0033] The transparent conductive layer containing the metal nanowires having the fused network structure can be formed, for example, by adding an additive to the metal nanowire dispersion to promote fusion. Examples of such additives include metal halides (e.g., LiCl, CsCl, NaF, NaCl, NaBr, NaI, KCl, MgCl2, CaCl2, AlCl3, AgF, etc.), inorganic acids (e.g., nitric acid, nitrous acid, sulfuric acid, etc.), organic acids (e.g., oxalic acid, citric acid, formic acid, acetic acid, lactic acid, propionic acid, butyric acid, acrylic acid, pyruvic acid, trichloroacetic acid, trifluoroacetic acid, hexanoic acid, octanoic acid, decanoic acid, dodecanoic (lauric) acid, tetradecanoic (myristic) acid, hexadecanoic (palmitic) acid, octadecanoic (stearic) acid, 2-ethylbutyric acid, 2-methyl ... Examples of suitable silver salts include silver nitrate, silver nitrite, silver lactate, silver chloride, silver sulfate, silver oxide, silver acetate, silver chlorate, silver sulfide, silver formate, silver hexanoate, silver octanoate, silver decanoate, silver dodecanoate, silver tetradecanoate, silver hexadecanoate, silver octadecanoate, silver pentanoate, silver pivalate, silver neoheptanoate, silver neononanoate, and silver neodecanoate, and compounds containing elements capable of forming silver salts (e.g., chlorine and sulfur) (e.g., hydrogen chloride and sodium chloride). Among these, metal halides are preferred, and NaCl, AgF, LiF, NaBr, or NaF is more preferred. In one embodiment, the transparent conductive layer containing the metal nanowires having the fused network structure can be formed by applying a metal nanowire dispersion containing the additive, followed by heat treatment and / or pressure treatment. The heat treatment temperature is, for example, 50°C to 200°C.

[0034] The transparent conductive layer containing the metal nanowires having the fused network structure may be formed by exposing a coating layer of the metal nanowire dispersion to an acid halide vapor, such as HCl, HBr, HI, or a mixture thereof.

[0035] Metal nanowires having a fused network structure and a method for producing the same are described, for example, in JP-A-2015-530693, the disclosure of which is incorporated herein by reference.

[0036] (polymer matrix) Any suitable polymer can be used as the polymer constituting the polymer matrix. Examples of such polymers include acrylic polymers; polyester polymers such as polyethylene terephthalate; aromatic polymers such as polystyrene, polyvinyltoluene, polyvinylxylene, polyimide, polyamide, and polyamideimide; polyurethane polymers; epoxy polymers; polyolefin polymers; acrylonitrile-butadiene-styrene copolymers (ABS); cellulose; silicone polymers; polyvinyl chloride; polyacetate; polynorbornene; synthetic rubber; and fluorine-containing polymers. Preferably, a curable resin (preferably a UV-curable resin) composed of a polyfunctional acrylate such as pentaerythritol triacrylate (PETA), neopentyl glycol diacrylate (NPGDA), dipentaerythritol hexaacrylate (DPHA), dipentaerythritol pentaacrylate (DPPA), or trimethylolpropane triacrylate (TMPTA) is used.

[0037] The polymer matrix can be formed by forming a layer of metal nanowires on a transparent substrate, applying a polymer solution onto the layer, and then drying or curing the applied layer, as described above, to form a transparent conductive layer in which the metal nanowires are present in the polymer matrix.

[0038] The polymer solution contains a polymer that constitutes the polymer matrix, or a precursor of the polymer (a monomer that constitutes the polymer).

[0039] The polymer solution may contain a solvent. Examples of the solvent contained in the polymer solution include alcohol-based solvents, ketone-based solvents, tetrahydrofuran, hydrocarbon-based solvents, and aromatic solvents. Preferably, the solvent is volatile. The boiling point of the solvent is preferably 200°C or less, more preferably 150°C or less, and even more preferably 100°C or less.

[0040] (Thiol compounds) The thiol compound may, for example, be a compound represented by general formula (1). HS-R (1) In formula (1), R is an aliphatic hydrocarbon group or aromatic hydrocarbon group having 1 to 30 carbon atoms, preferably an aliphatic hydrocarbon group or aromatic hydrocarbon group having 1 to 20 carbon atoms. R may be linear or branched. R may contain a double bond and / or a triple bond at any appropriate position. R may have any appropriate substituent. Examples of the substituent include an SH group, a hydroxyl group, an NH2 group, an alkyl ester group, a carboxyl group, an allyl group, and a halogen group. R may have a substituent containing an element such as N, S, O, Si, or P. Specific examples of thiol compounds include α-thioglycerol, aminoethanethiol, thioglycolic acid, methyl thioglycolate, ethyl thioglycolate, propyl thioglycolate, butyl thioglycolate, t-butyl thioglycolate, 2-ethylhexyl thioglycolate, octyl thioglycolate, isooctyl thioglycolate, decyl thioglycolate, dodecyl thioglycolate, thioglycolic acid esters of ethylene glycol, thioglycolic acid esters of neopentyl glycol, and thioglycolic acid esters of pentaerythritol.

[0041] In one embodiment, a thiol compound having a dithiolane skeleton (preferably a 1,2-dithiolane skeleton) is used. Thiol compounds having a dithiolane skeleton are characterized by their resistance to reaction with compounds constituting the polymer matrix. Therefore, they do not inhibit the protective function of the polymer matrix and can form a conductive layer that exhibits excellent adhesion to the transparent substrate. Furthermore, thiol compounds having a dithiolane skeleton have two bonding points, so they can densely coat the metal nanowires. Even a small amount of such a thiol compound can contribute to improved moisture resistance. When a small amount of thiol compound is added, they do not inhibit the protective function of the polymer matrix and can form a conductive layer that exhibits excellent adhesion to the transparent substrate.

[0042] Examples of thiol compounds having a dithiolane skeleton include α-lipoic acid, 5-(1,2-dithiolan-3-yl)pentanamide, and 4-methyl-1,2-dithiolane-4-carboxamid. Among these, α-lipoic acid is preferred. The use of α-lipoic acid not only significantly enhances the above-mentioned effects, but also allows the production of a transparent conductive film with superior durability due to the radical trapping, antioxidant, and other effects of α-lipoic acid.

[0043] In one embodiment, the thiol compound is an alkylthiol. Specific examples of the alkylthiol include methanethiol, ethanethiol, propanethiol, n-octanethiol, n-dodecanethiol, hexadecanethiol, and n-octadecanethiol.

[0044] The content of the thiol compound is preferably 0.04 to 10 parts by weight, more preferably 0.1 to 8 parts by weight, and even more preferably 0.12 to 5 parts by weight, relative to 100 parts by weight of the polymer constituting the polymer matrix. Within this range, a transparent conductive film with excellent moisture resistance can be obtained. In one embodiment, when a thiol compound having a dithiolane skeleton is used as the thiol compound, the content of the thiol compound having a dithiolane skeleton is preferably 0.1 to 5 parts by weight, more preferably 0.15 to 3 parts by weight, relative to 100 parts by weight of the polymer constituting the polymer matrix. When the content of the thiol compound having a dithiolane skeleton is within this range, a transparent conductive film with remarkably excellent conductivity in addition to moisture resistance can be obtained. If the content of the thiol compound having a dithiolane skeleton is too high, the thiol compound may react with the metal nanowires, resulting in a decrease in conductivity.

[0045] (coupling agent) In one embodiment, the transparent conductive layer (essentially, the polymer matrix) further contains a coupling agent. A silane coupling agent is preferably used as the coupling agent. By adding a coupling agent, a transparent conductive film having excellent adhesion between the transparent substrate and the transparent conductive layer can be obtained. Generally, coupling agents act to reduce moisture resistance (humidification reliability). However, according to the present invention, by using a thiol-based compound in combination with a coupling agent, it is possible to obtain a transparent conductive film having excellent adhesion between the transparent substrate and the transparent conductive layer while preventing deterioration of the metal nanowires and maintaining humidification reliability. In other words, the present invention is advantageous in that the effectiveness of the coupling agent is enhanced by including a thiol-based compound.

[0046] As the silane coupling agent, an amino-based silane coupling agent can be preferably used. Alternatively, an amino-based silane coupling agent and an acrylic-based silane coupling agent may be used in combination.

[0047] Examples of amino-based silane coupling agents include γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltriethoxysilane, N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane, γ-phenylaminopropyltrimethoxysilane, and 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine. Furthermore, many amino-based silane coupling agents are commercially available. Specific examples of commercially available products include KBE-9103, KBM-575, and KBM-6123 manufactured by Shin-Etsu Chemical Co., Ltd., and A-1102, A-1122, and A-1170 manufactured by Momentive Performance Materials Japan, Inc. 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine is preferred.

[0048] The acrylic silane coupling agent is typically a silane coupling agent having a (meth)acrylic group in its skeleton. Examples of the acrylic silane coupling agent include 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-acryloxypropyltriethoxysilane, methacryloxymethyltrimethoxysilane, methacryloxymethyltriethoxysilane, acryloxymethyltrimethoxysilane, acryloxymethyltriethoxysilane, and 3-methacryloxypropylmethyldimethoxysilane. Furthermore, many acrylic silane coupling agent products are commercially available. Specific examples of commercially available products include KBM-502 and KBM-5103 manufactured by Shin-Etsu Chemical Co., Ltd. Preferably, 3-acryloxypropyltrimethoxysilane or 3-methacryloxypropylmethyldimethoxysilane is used.

[0049] The content of the coupling agent (preferably a silane coupling agent) is preferably 0.001 to 20 parts by weight, more preferably 0.02 to 10 parts by weight, relative to 100 parts by weight of the polymer constituting the polymer matrix. Within this range, a transparent conductive film having excellent adhesion between the transparent substrate and the transparent conductive layer can be obtained.

[0050] C. Transparent base material The thickness of the transparent substrate is preferably 8 μm to 500 μm, more preferably 10 μm to 250 μm, still more preferably 10 μm to 150 μm, and particularly preferably 15 μm to 100 μm.

[0051] The total light transmittance of the transparent substrate is preferably 80% or more, more preferably 85% or more, and particularly preferably 90% or more. Within this range, a transparent conductive film suitable for use in touch panels and the like can be obtained.

[0052] Any appropriate resin can be used as the resin constituting the transparent substrate as long as the effects of the present invention can be obtained. Examples of resins constituting the transparent substrate include cycloolefin-based resins, polyimide-based resins, polyvinylidene chloride-based resins, polyvinyl chloride-based resins, polyethylene terephthalate-based resins, and polyethylene naphthalate-based resins. Cycloolefin-based resins are preferred. By using cycloolefin-based resins, a transparent substrate having high moisture barrier properties can be obtained inexpensively.

[0053] As the cycloolefin-based resin, for example, polynorbornene can be preferably used. Polynorbornene refers to a (co)polymer obtained by using norbornene-based monomers having a norbornene ring as part or all of the starting materials (monomers).

[0054] Various polynorbornene products are commercially available, including, for example, "Zeonex" and "Zeonor" manufactured by Zeon Corporation, "Arton" manufactured by JSR Corporation, "Topas" manufactured by TICONA, and "APEL" manufactured by Mitsui Chemicals, Inc.

[0055] The glass transition temperature of the resin constituting the transparent substrate is preferably 50°C to 200°C, more preferably 60°C to 180°C, and even more preferably 70°C to 160°C. If the transparent substrate has a glass transition temperature in this range, deterioration during the formation of the transparent conductive layer can be prevented.

[0056] The transparent substrate may further contain any appropriate additives as necessary. Specific examples of additives include plasticizers, heat stabilizers, light stabilizers, lubricants, antioxidants, UV absorbers, flame retardants, colorants, antistatic agents, compatibilizers, crosslinkers, and thickeners. The type and amount of additives used may be appropriately determined depending on the purpose.

[0057] The method for obtaining the transparent substrate can be any suitable molding method, and can be appropriately selected from, for example, compression molding, transfer molding, injection molding, extrusion molding, blow molding, powder molding, FRP molding, and solvent casting.Among these manufacturing methods, extrusion molding or solvent casting is preferably used.This is because it can improve the smoothness of the obtained transparent substrate and obtain good optical uniformity.The molding conditions can be appropriately set according to the composition and type of resin used.

[0058] If necessary, the transparent substrate may be subjected to various surface treatments. Any appropriate method may be used for the surface treatment depending on the purpose. Examples of the surface treatment include low-pressure plasma treatment, ultraviolet irradiation treatment, corona treatment, flame treatment, and acid or alkali treatment. In one embodiment, the transparent substrate is surface-treated to make the surface of the transparent substrate hydrophilic. [Example]

[0059] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Evaluation methods in the examples and comparative examples are as follows.

[0060] (1) Surface resistance Measurement was performed using a NAPSON product called "EC-80" at a temperature of 23°C. (2) Hayes Measurement was performed using an HR-100 product manufactured by Murakami Color Research Institute Co., Ltd. The measurement temperature was 23°C. The average value obtained by repeating the measurement three times was used as the measured value. (3) Humidification test The transparent conductive film was placed in a humidified oven at a temperature of 65°C and a humidity of 90%, and after leaving it for 500 hours, the above measurements (1) and (2) were carried out. (4) Adhesion (cross-cut peel test) The transparent conductive film was placed in a humidified oven at a temperature of 65°C and a humidity of 90%, and after leaving it for 500 hours, 100 grids were formed on the transparent conductive layer side of the transparent conductive film, and a cross-cut peel test was carried out in accordance with JIS K 5400. The test was carried out on three transparent conductive films, and the number of peeled grids was counted.

[0061] [Production Example 1] (Synthesis of Silver Nanowires and Preparation of Silver Nanowire Dispersion) In a reaction vessel equipped with a stirrer, 5 ml of anhydrous ethylene glycol and an anhydrous ethylene glycol solution of PtCl (concentration: 1.5 × 10 -40.5 ml of AgNO3 (concentration: 0.12 mol / L) was added. After 4 minutes, 2.5 ml of anhydrous ethylene glycol solution of AgNO3 (concentration: 0.12 mol / L) and 5 ml of anhydrous ethylene glycol solution of polyvinylpyrrolidone (MW: 55000) (concentration: 0.36 mol / L) were simultaneously added dropwise to the resulting solution over 6 minutes. After this addition, the mixture was heated to 160°C and reacted for over 1 hour until AgNO3 was completely reduced, producing silver nanowires. Next, acetone was added to the reaction mixture containing the silver nanowires obtained as described above until the volume of the reaction mixture was 5 times that of the reaction mixture, and the reaction mixture was centrifuged (2000 rpm, 20 minutes) to obtain silver nanowires. The obtained silver nanowires had a minor axis of 30 nm to 40 nm, a major axis of 30 nm to 50 nm, and a length of 5 μm to 50 μm. The silver nanowires (concentration: 0.2 wt %) and pentaethylene glycol dodecyl ether (concentration: 0.1 wt %) were dispersed in pure water to prepare a silver nanowire dispersion liquid I.

[0062] [Example 1] A commercially available long cycloolefin (norbornene) resin film (manufactured by Zeon Corporation, product name "ZEONOR ZF16", thickness 40 μm) was used as the substrate. Silver nanowire dispersion liquid I was applied to this substrate and dried. Next, as a material for forming the overcoat layer, resin composition A was prepared by blending 80 parts by weight of DIC Corporation's product name "UNIDIC ELS-888" and 20 parts by weight of DIC Corporation's product name "UNIDIC RS28-605". This resin composition A was applied to the conductive layer, and ultraviolet light was irradiated at an exposure dose of 230 mJ / cm. 2 The transparent conductive film had a surface resistance of 50 Ω and a thickness of 60 nm.

[0063] [Example 2] A transparent conductive film was obtained in the same manner as in Example 1, except that the amount of α-lipoic acid added was 3 parts by weight per 100 parts by weight of the resin composition A. The obtained transparent conductive film was subjected to the above evaluations. The results are shown in Table 1.

[0064] [Example 3] A transparent conductive film was obtained in the same manner as in Example 1, except that 0.15 parts by weight of decanethiol was used instead of 0.15 parts by weight of α-lipoic acid. The obtained transparent conductive film was subjected to the above-mentioned evaluations. The results are shown in Table 1.

[0065] [Example 4] A transparent conductive film was obtained in the same manner as in Example 3, except that the amount of decanethiol added was 3 parts by weight. The obtained transparent conductive film was subjected to the above-mentioned evaluations. The results are shown in Table 1.

[0066] [Example 5] A transparent conductive film was obtained in the same manner as in Example 1, except that 0.15 parts by weight of perfluorodecanethiol was used instead of 0.15 parts by weight of α-lipoic acid. The obtained transparent conductive film was subjected to the above-mentioned evaluations. The results are shown in Table 1.

[0067] [Example 6] A transparent conductive film was obtained in the same manner as in Example 5, except that the amount of perfluorodecanethiol added was 3 parts by weight. The obtained transparent conductive film was subjected to the above-mentioned evaluations. The results are shown in Table 1.

[0068] [Comparative Example 1] A transparent conductive film was obtained in the same manner as in Example 1, except that the thiol compound and the silane coupling agent were not added. The obtained transparent conductive film was subjected to the above-mentioned evaluations. The results are shown in Table 1.

[0069] Comparative Example 2 A transparent conductive film was obtained in the same manner as in Example 1, except that no thiol-based compound was added. The obtained transparent conductive film was subjected to the above-mentioned evaluations. The results are shown in Table 1.

[0070] Comparative Example 3 A transparent conductive film was obtained in the same manner as in Example 1, except that no thiol compound was added and the thickness of the transparent conductive layer was 90 nm. The obtained transparent conductive film was subjected to the above-mentioned evaluations. The results are shown in Table 1.

[0071] [Table 1]

[0072] As is clear from Table 1, according to the present invention, a transparent conductive film can be obtained that contains metal nanowires and yet has excellent adhesion of the transparent conductive layer to the transparent substrate, even under humidified conditions, and has little change in resistance value and haze, i.e., a transparent conductive film that has excellent humidification reliability. [Explanation of symbols]

[0073] 10 Transparent base material 20 Transparent conductive layer 21 Metal nanowires 22 Polymer Matrix 100 Transparent conductive film

Claims

1. A transparent substrate; a transparent conductive layer disposed on at least one side of the transparent substrate; the transparent conductive layer comprises metal nanowires and a polymer matrix; the polymer matrix comprises a thiol-based compound; the thiol compound is a thiol compound having a dithiolane skeleton; Transparent conductive film.

2. 2. The transparent conductive film according to claim 1, wherein the thiol compound is α-lipoic acid.

3. 3. The transparent conductive film according to claim 1, wherein the content of the thiol compound having a dithiolane skeleton is 0.1 to 5 parts by weight based on 100 parts by weight of the polymer constituting the polymer matrix.

4. The transparent conductive film according to claim 1 , wherein the metal nanowires have a fused network structure.

5. The transparent conductive film according to claim 1 , wherein the transparent conductive layer further contains a silane coupling agent.

6. The transparent conductive film according to claim 1 , wherein the transparent conductive layer has a visible light transmittance of 80% or more.

7. 7. The transparent conductive film according to claim 1, wherein the transparent conductive layer has a sheet resistivity of 200 Ω / □ or less.

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