Transparent conductive film

Abstract

To provide a transparent conductive film excellent in both flexibility and transparency.SOLUTION: A transparent conductive film includes a first transparent conductive layer, a substrate, and a second transparent conductive layer in this order. The first transparent conductive layer includes a metal nanowire. The second transparent conductive layer is composed of a metal oxide. In one embodiment, the metal oxide composing the second transparent conductive layer is an indium-tin complex oxide.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 resin film have been widely used as electrodes for touch sensors, etc. However, transparent conductive films with a metal oxide layer formed on them have the problem of insufficient flexibility and being prone to cracking due to physical stress such as bending.

[0003] Furthermore, transparent conductive films have been proposed that include a conductive layer containing metal nanowires made of silver, copper, or the like. Such transparent conductive films have the advantage of excellent flexibility. However, conductive layers containing metal nanowires tend to have high haze and are prone to developing metal-derived coloring, which presents problems in terms of optical properties. The lower the resistance of the conductive layer, the thicker it needs to be, and increasing the thickness of the conductive layer exacerbates the problems with optical properties. [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 problems, and an object of the present invention is to provide a transparent conductive film that is excellent in both flexibility and optical properties. [Means for solving the problem]

[0006] The transparent conductive film of the present invention comprises a substrate and a transparent conductive laminate disposed on at least one side of the substrate, the transparent conductive laminate comprising a first transparent conductive layer composed of a metal oxide and a second transparent conductive layer including a metal nanostructure. In one embodiment, the metal oxide is an indium-tin composite oxide. In one embodiment, the metal nanostructure is a metal nanowire. In one embodiment, the transparent conductive laminate is disposed so that the second transparent conductive layer faces the substrate. In one embodiment, the transparent conductive laminate is disposed so that the first transparent conductive layer faces the substrate. In one embodiment, the transparent conductive film has a surface resistance of 100 Ω / □ or less. In one embodiment, when the transparent conductive film is hung on a round rod having a diameter of 2 mm and bent, the rate of increase in surface resistance (= surface resistance after bending / surface resistance before bending) is 1.3 or less. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a transparent conductive film that is excellent in both flexibility and optical properties. [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. [Figure 2] FIG. 2 is a schematic cross-sectional view of a transparent conductive film according to another embodiment of the present invention. [Figure 3] FIG. 2 is a schematic cross-sectional view of a transparent conductive film according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] A. Overall structure of transparent conductive film FIG. 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 includes a substrate 10 and a transparent conductive laminate 20 disposed on at least one side of the substrate 10. The transparent conductive laminate 20 includes a first transparent conductive layer 21 and a second transparent conductive layer 22. The first transparent conductive layer 21 is composed of a metal oxide. The second transparent conductive layer 22 includes a metal nanostructure. The metal nanostructure may be, for example, a metal nanowire, a metal nanoparticle, or the like. Although not shown, the transparent conductive film may further include any other appropriate layers. For example, a hard coat layer may be disposed between the substrate and the transparent conductive laminate.

[0010] 1, the transparent conductive laminate 20 is disposed so that the second transparent conductive layer (metal nanostructure layer) 22 faces the substrate 10. That is, the first transparent conductive layer (metal oxide layer) 21, the second transparent conductive layer (metal nanostructure layer) 22, and the substrate 10 are disposed in this order.

[0011] 2 is a schematic cross-sectional view of a transparent conductive film according to another embodiment of the present invention. In this embodiment, a transparent conductive laminate 20 is disposed so that a first transparent conductive layer (metal oxide layer) 21 faces a substrate 10. That is, a second transparent conductive layer (metal nanostructure layer) 22, a first transparent conductive layer (metal oxide layer) 21, and a substrate 10 are disposed in this order.

[0012] The transparent conductive laminate 20 may be disposed on both sides of the substrate 10. Examples of a configuration in which the transparent conductive laminate 20 is disposed on both sides of the substrate 10 include the following configurations. A configuration including a first transparent conductive layer 21 / a second transparent conductive layer 22 / a substrate 10 / a second transparent conductive layer 22 / a first transparent conductive layer 21 in this order (FIG. 3(a)). A configuration including a first transparent conductive layer 21 / a second transparent conductive layer 22 / a substrate 10 / a first transparent conductive layer 21 / a second transparent conductive layer 22 in this order (FIG. 3(b)). A configuration in which the second transparent conductive layer 22 / first transparent conductive layer 21 / substrate 10 / second transparent conductive layer 22 / first transparent conductive layer 21 are provided in this order (FIG. 3(c)). A configuration in which the second transparent conductive layer 22 / first transparent conductive layer 21 / substrate 10 / first transparent conductive layer 21 / second transparent conductive layer 22 are provided in this order (FIG. 3(d)).

[0013] In the present invention, a transparent conductive film having excellent flexibility and excellent optical properties can be obtained by including a first transparent conductive layer composed of a metal oxide and a second transparent conductive layer containing a metal nanostructure. More specifically, the transparent conductive film of the present invention can be a transparent conductive film having excellent flexibility and a small increase in resistance when bent by including a second transparent conductive layer containing a metal nanostructure. Furthermore, a conductive layer composed of a metal nanostructure is characterized by its tendency to reduce resistance. Therefore, in the present invention, a transparent conductive film having excellent conductivity can be easily obtained by including a second transparent conductive layer. On the other hand, a conductive layer composed of a metal nanostructure can generally adversely affect optical properties. For example, problems such as increased haze or the development of metallic coloring can occur. According to the present invention, by including both a first transparent conductive layer composed of a metal oxide layer and a transparent conductive layer containing a metal nanostructure, a transparent conductive film having excellent conductivity while suppressing deterioration of optical properties can be provided. Furthermore, by disposing the first transparent conductive layer (metal oxide layer) on the outside of the second transparent conductive layer (metal nanostructure layer), corrosion of the metal nanostructures in the second transparent conductive layer can be prevented.

[0014] The surface resistance of the transparent conductive film of the present invention is preferably 0.01 Ω / □ to 1000 Ω / □, more preferably 0.1 Ω / □ to 500 Ω / □, particularly preferably 0.1 Ω / □ to 300 Ω / □, and most preferably 0.1 Ω / □ to 100 Ω / □. In one embodiment, the surface resistance of the transparent conductive film is 100 Ω / □ or less.

[0015] When the transparent conductive film of the present invention is bent around a round rod having a diameter of 2 mm (preferably a diameter of 1 mm), the rate of increase in surface resistance (= surface resistance after bending / surface resistance before bending) is preferably 1.3 or less, more preferably 1.2 or less, and even more preferably 1.1 or less. Regardless of which side of the transparent conductive film is bent facing outward, the rate of increase in surface resistance is preferably within the above range. Furthermore, when transparent conductive laminates are disposed on both sides of the substrate, the surface resistance on both sides is preferably within the above range.

[0016] When a transparent conductive laminate is disposed on one side of a substrate, when the transparent conductive laminate is hung on a round bar having a diameter of 2 mm (preferably, a diameter of 1 mm) and bent with the transparent conductive laminate facing outward, the rate of increase in the surface resistance of the transparent conductive laminate side (= surface resistance after bending / surface resistance before bending) is preferably 1.3 or less, more preferably 1.2 or less, and even more preferably 1.1 or less.

[0017] When a transparent conductive laminate is disposed on both sides of a substrate, when the substrate is bent around a round rod having a diameter of 2 mm (preferably, a diameter of 1 mm), the rate of increase in the surface resistance of the transparent conductive laminate on the outer side of the bend (=surface resistance after bending / surface resistance before bending) is preferably 1.3 or less, more preferably 1.2 or less, and even more preferably 1.1 or less.

[0018] The haze value of the transparent conductive film of the present invention is preferably 1% or less, more preferably 0.7% or less, and even more preferably 0.5% or less. The smaller the haze value, the better, and the lower limit thereof is, for example, 0.05%.

[0019] The total light transmittance of the transparent conductive film of the present invention is preferably 80% or more, more preferably 85% or more, and particularly preferably 90% or more.

[0020] The thickness of the transparent conductive film of the present invention is preferably 10 μm to 500 μm, more preferably 15 μm to 300 μm, and even more preferably 20 μm to 200 μm.

[0021] B. First transparent conductive layer As described above, the first transparent conductive layer is composed of a metal oxide. Examples of metal oxides include indium oxide, tin oxide, zinc oxide, indium-tin composite oxide, tin-antimony composite oxide, zinc-aluminum composite oxide, and indium-zinc composite oxide. Among these, indium-tin composite oxide (ITO) is preferred. The metal oxide may be a crystallized metal oxide. The crystallized metal oxide refers to a metal oxide obtained by forming a metal oxide film and then heating (for example, heating at 120°C to 200°C), as described below.

[0022] The total light transmittance of the first transparent conductive layer is preferably 80% or more, more preferably 85% or more, and even more preferably 90% or more.

[0023] The first transparent conductive layer can be formed, for example, by forming a metal oxide layer by any appropriate film-forming method (e.g., vacuum deposition, sputtering, CVD, ion plating, spraying, etc.) to obtain the first transparent conductive layer. The metal oxide layer may be used as the first transparent conductive layer as is, or may be further heated to crystallize the metal oxide. The heating temperature is, for example, 120°C to 200°C.

[0024] The thickness of the first transparent conductive layer is preferably 50 nm or less, more preferably 40 nm or less. Within this range, a transparent conductive film with excellent light transmittance can be obtained. The lower limit of the thickness of the conductive layer is preferably 1 nm, more preferably 5 nm.

[0025] The first transparent conductive layer may be patterned. Any suitable patterning method may be used depending on the shape of the conductive layer. For example, patterning may be performed by etching, laser, or the like. The pattern shape of the first transparent conductive layer may be any suitable shape depending on the application. Examples include the patterns described in JP-A-2011-511357, JP-A-2010-164938, JP-A-2008-310550, JP-A-2003-511799, and JP-A-2010-541109.

[0026] C. Second Transparent Conductive Layer As described above, the second transparent conductive layer includes a metal nanostructure. Examples of the metal nanostructure include a metal nanowire, a metal nanomesh, a metal nanorod, a metal nanotube, a metal nanopyramid, a metal particle, or a combination thereof. Preferably, the second transparent conductive layer includes a metal nanowire.

[0027] In one embodiment, the second transparent conductive layer further comprises a polymer matrix. In this embodiment, metal nanostructures (e.g., metal nanowires) are present in the polymer matrix. In the second transparent conductive layer composed of a polymer matrix, the metal nanostructures are protected by the polymer matrix. As a result, corrosion of the metal nanostructures is prevented, and a transparent conductive film with superior durability can be obtained.

[0028] The thickness of the second transparent conductive layer is preferably 10 nm to 1000 nm, more preferably 20 nm to 500 nm. When the second transparent conductive layer contains a polymer matrix, the thickness of the second transparent conductive layer corresponds to the thickness of the polymer matrix.

[0029] In one embodiment, the second transparent conductive layer is patterned. Any suitable method can be adopted as the patterning method depending on the form of the second transparent conductive layer. The pattern shape of the second transparent conductive layer can be any suitable shape depending on the application. Examples include the patterns described in JP-A-2011-511357, JP-A-2010-164938, JP-A-2008-310550, JP-A-2003-511799, and JP-A-2010-541109. After the second transparent conductive layer is formed on the substrate, it can be patterned using any suitable method depending on the form of the second transparent conductive layer.

[0030] The total light transmittance of the second transparent conductive layer is preferably 85% or more, more preferably 90% or more, and even more preferably 95% or more.

[0031] The metal nanowires are conductive materials made of metal, shaped like needles or threads, and nanometer-sized diameters. The metal nanowires may be straight or curved. By using a second transparent conductive layer made of metal nanowires, the metal nanowires form a mesh, allowing good electrical conduction paths to be formed even with a small amount of metal nanowires, resulting in a transparent conductive film with low electrical resistance.

[0032] 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 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.

[0033] The thickness of the metal nanowires is preferably less than 500 nm, more preferably less than 200 nm, particularly preferably 100 nm or less, and most preferably 60 nm or less. Within this range, a second transparent conductive layer with high light transmittance can be formed. The lower limit of the thickness of the metal nanowires is, for example, 10 nm.

[0034] The length of the metal nanowires is preferably 1 μm to 1000 μm, more preferably 1 μm to 500 μm, and particularly preferably 1 μm to 100 μm. If the length is within this range, a transparent conductive film with high conductivity can be obtained.

[0035] Any suitable metal can be used as the metal constituting the metal nanostructure (e.g., metal nanowire) as long as it is a metal with high conductivity. Examples of metals constituting the metal nanostructure (e.g., metal nanowire) include silver, gold, platinum, copper, and nickel. Materials obtained by plating these metals (e.g., platinum plating) may also be used. The metal nanowire is preferably composed of one or more metals selected from the group consisting of silver, gold, platinum, copper, and nickel, and more preferably composed of one or more metals selected from the group consisting of silver, gold, platinum, and copper.

[0036] 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.

[0037] The content of the metal nanostructures (e.g., metal nanowires) in the second transparent conductive layer is preferably 80% by weight or less, more preferably 70% by weight or less, and even more preferably 50% by weight or less, based on the total weight of the second transparent conductive layer. Within this range, a transparent conductive film with excellent conductivity and light transmittance can be obtained.

[0038] 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.

[0039] When the second transparent conductive layer is composed of a polymer matrix and the metal nanowires are silver nanowires, the density of the second transparent conductive layer is preferably 1.0 g / cm 3 ~10.5g / cm 3 and more preferably 1.0 g / cm 3 ~3.0g / cm 3 Within this range, a transparent conductive film having excellent conductivity and light transmittance can be obtained.

[0040] The second transparent conductive layer can be formed by applying a composition for forming a second conductive layer containing metal nanostructures (e.g., metal nanowires) to a substrate (or a laminate of the substrate and other layers), and then drying the applied layer.

[0041] The second conductive layer-forming composition may contain any appropriate solvent in addition to metal nanostructures (e.g., metal nanowires). The second conductive layer-forming composition may be prepared as a dispersion of metal nanostructures (e.g., metal nanowires). Examples of the solvent include water, alcohol-based solvents, ketone-based solvents, ether-based solvents, hydrocarbon-based solvents, and aromatic solvents. From the viewpoint of reducing environmental impact, it is preferable to use water. The second conductive layer-forming composition may further contain any appropriate additive depending on the purpose. Examples of the additive include a corrosion inhibitor that prevents corrosion of the metal nanostructures (e.g., metal nanowires), and a surfactant that prevents aggregation of the metal nanostructures (e.g., metal nanowires). The type, number, and amount of the additive used may be appropriately determined depending on the purpose.

[0042] When the second transparent conductive layer includes a polymer matrix, the polymer matrix can be formed by applying a second conductive layer-forming composition and drying it as described above, then applying a polymer solution (polymer composition, monomer composition) onto the layer composed of metal nanowires, and then drying or curing the applied layer of the polymer solution. Alternatively, the second transparent conductive layer may be formed using a second conductive layer-forming composition containing a polymer that constitutes the polymer matrix.

[0043] The dispersion concentration of the metal nanowires in the composition for forming the second conductive layer is preferably 0.1% by weight to 1% by weight, which allows the formation of a second transparent conductive layer having excellent conductivity and light transmittance.

[0044] Any appropriate method can be used to apply the second conductive layer-forming composition. Examples of application methods 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 preferably 80°C to 150°C. The drying time is typically 1 to 10 minutes.

[0045] The polymer solution contains a polymer that constitutes the polymer matrix, or a precursor of the polymer (a monomer that constitutes the polymer).

[0046] 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.

[0047] D. Base material The substrate is typically made of any suitable resin. Examples of resins constituting the 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. Preferably, a cycloolefin-based resin is used. By using a substrate made of a cycloolefin-based resin, a transparent conductive film with excellent flexibility can be obtained.

[0048] For example, polynorbornene can be preferably used as the cycloolefin resin. Polynorbornene refers to a (co)polymer obtained by using a norbornene-based monomer having a norbornene ring as part or all of the starting material (monomer). Various polynorbornene products are commercially available. Specific examples include "Zeonex" and "Zeonor" manufactured by Zeon Corporation, "Arton" manufactured by JSR Corporation, "Topas" manufactured by TICONA, and "APEL" manufactured by Mitsui Chemicals, Inc.

[0049] The glass transition temperature of the resin constituting the 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 substrate has a glass transition temperature within this range, deterioration during the formation of the transparent conductive laminate can be prevented.

[0050] The thickness of the 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 tensile breaking strength of the substrate is preferably 50 MPa or more, more preferably 70 MPa or more, and even more preferably 100 MPa or more. Within this range, a transparent conductive film with particularly excellent flexibility can be obtained. The tensile breaking strength can be measured at room temperature in accordance with JIS K 7161.

[0052] The total light transmittance of the 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.

[0053] The 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.

[0054] If necessary, the substrate may be subjected to various surface treatments. Any appropriate method may be used for the surface treatment depending on the purpose. Examples 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. By making the substrate hydrophilic, excellent processability can be achieved when applying a transparent conductive layer-forming composition prepared using an aqueous solvent. Furthermore, a transparent conductive film having excellent adhesion between the substrate and the transparent conductive layer can be obtained. [Example]

[0055] 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.

[0056] (1) Initial resistance A test piece was obtained by applying Ag paste (1 cm long x 1 cm wide) to both ends of a transparent conductive film (15 cm long x 1 cm wide) in the longitudinal direction on the transparent conductive laminate side. The conductivity between the Ag pastes was confirmed with a tester, and the surface resistance was measured.

[0057] (2) Resistance after bending Test pieces were obtained in the same manner as in (1) above. This test piece was hung on a stainless steel round bar having the diameter shown in Table 1, with the transparent conductive laminate side facing outward, and bent 180° so that the longitudinal direction was bent along the round bar. Then, weights (500 g each) were hung on both ends of the longitudinal direction via clips, and the test piece was held in this state for 10 seconds. After the above operation, the copper clip was removed, and the electrical continuity between the Ag paste portions was confirmed with a tester, and the surface resistance value was measured.

[0058] (3) Resistance increase rate The resistance value after bending obtained in (2) above was divided by the initial resistance value obtained in (1) above (resistance value after bending / initial resistance value) to calculate the resistance value increase rate.

[0059] [Manufacturing Example 1] (Manufacturing of metal nanowires) In a reaction vessel equipped with a stirrer, 5 ml of anhydrous ethylene glycol and 0.5 ml of anhydrous ethylene glycol solution of PtCl2 (concentration: 1.5 x 10-4 mol / L) were added at 160 °C. 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 silver nanowires (concentration: 0.2% by weight) and pentaethylene glycol dodecyl ether (concentration: 0.1% by weight) were dispersed in pure water to prepare a silver nanowire dispersion.

[0060] [Example 1] (Preparation of Transparent Conductive Layer-Forming Composition (PN)) The silver nanowire dispersion liquid (25 parts by weight) was diluted with 75 parts by weight of pure water to prepare a composition for forming a transparent conductive layer (PN) with a solid content concentration of 0.05% by weight. (Preparation of Monomer Composition) One part by weight of pentaerythritol triacrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., trade name "Viscoat #300") and 0.2 parts by weight of a photopolymerization initiator (manufactured by BASF, trade name "Irgacure 907") were diluted with 80 parts by weight of isopropyl alcohol and 19 parts by weight of diacetone alcohol to obtain a monomer composition with a solid content concentration of 1% by weight. (Preparation of transparent conductive film) The transparent conductive layer-forming composition (PN) was applied to one side of a substrate (polycycloolefin film (manufactured by Zeon Corporation, trade name "ZEONOR (registered trademark)", thickness 40 μm) and dried. Furthermore, the above-mentioned monomer composition was applied to the transparent conductive layer-forming composition (PN) coating layer and dried at 80°C for 1 minute, and then 300 mJ / cm 2 The film was then exposed to ultraviolet light for 1000 s to form a second transparent conductive layer. Next, a first transparent conductive layer consisting of an indium tin oxide layer with a thickness of 32 nm was formed on the second transparent conductive layer by sputtering. The resulting conductive film was wound around a plastic core to produce a conductive film roll. The conductive film roll was then placed in an air-circulating oven and heated at 140°C for 90 minutes to convert the indium tin oxide from amorphous to crystalline, producing a transparent conductive film with a surface resistance of 45 Ω / □.

[0061] [Comparative Example 1] (Formation of cured resin layer) As a material for forming the cured resin layer, a resin composition solution was prepared by mixing 80 parts by weight of "Unidic ELS-888" manufactured by DIC Corporation and 20 parts by weight of "Unidic RS28-605" manufactured by DIC Corporation. (Preparation of transparent conductive film) The prepared resin composition solution was applied to one side of a substrate (polycycloolefin film (manufactured by Zeon Corporation, trade name "ZEONOR (registered trademark)", thickness 40 μm) and dried at 80°C for 1 minute. After that, ultraviolet light was immediately irradiated from an ozone-type high-pressure mercury lamp (UV intensity 180 mW / cm2, cumulative light dose: 230 mJ / cm2) to form a cured resin layer with a thickness of 1.0 μm. Next, a transparent conductive layer composed of an indium tin oxide layer with a thickness of 50 nm was formed by sputtering. The conductive film thus obtained was wound around a plastic core to produce a conductive film roll. The conductive film roll was then placed in an air-circulating oven and heated at 140°C for 90 minutes to convert the indium tin oxide from amorphous to crystalline, producing a transparent conductive film with a surface resistance of 41 Ω / □.

[0062] [Table 1] [Explanation of symbols]

[0063] 10 Base material 20 Transparent conductive laminate 21 First transparent conductive layer 22 Second transparent conductive layer 100, 200 Transparent conductive film

Claims

1. A substrate and a transparent conductive laminate disposed on at least one side of the substrate, The transparent conductive laminate includes a first transparent conductive layer made of a metal oxide and a second transparent conductive layer including a metal nanostructure. Transparent conductive film.

2. 2. The transparent conductive film according to claim 1, wherein the metal oxide is an indium-tin composite oxide.

3. The transparent conductive film according to claim 1 , wherein the metal nanostructure is a metal nanowire.

4. The transparent conductive film according to claim 1 , wherein the transparent conductive laminate is disposed so that the second transparent conductive layer faces the substrate.

5. The transparent conductive film according to claim 1 , wherein the transparent conductive laminate is disposed so that the first transparent conductive layer faces the substrate.

6. 6. The transparent conductive film according to claim 1, which has a surface resistance of 100 Ω / □ or less.

7. 7. The transparent conductive film according to claim 1, wherein the rate of increase in surface resistance when the transparent conductive film is bent around a round rod having a diameter of 2 mm (= surface resistance after bending / surface resistance before bending) is 1.3 or less.

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