Transparent conductive film

Abstract

To provide a transparent conductive film that is excellent in both flexibility and transparency.SOLUTION: The transparent conductive film 100 includes a first transparent conductive layer 21, a second transparent conductive layer 22, and a substrate 10 in this order. The first transparent conductive layer includes a metal nanowire. The second transparent conductive layer is composed of metal oxide. As an example, the metal oxide forming the second transparent conductive layer is an indium-tin composite oxide.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] Conventionally, as a transparent conductive film used for electrodes of a touch sensor or the like, a transparent conductive film in which a metal oxide layer such as an indium tin composite oxide layer (ITO layer) is formed on a resin film has been widely used. However, the transparent conductive film with a metal oxide layer has a problem that its flexibility is insufficient and cracks are likely to occur due to physical stress such as bending.

[0003] In addition, as a transparent conductive film, a transparent conductive film provided with a conductive layer containing metal nanowires using silver, copper, or the like has been proposed. Such a transparent conductive film has an advantage of excellent flexibility. However, the conductive layer containing metal nanowires tends to have high haze, and there are problems from the viewpoint of optical properties such as the generation of color derived from the metal. The conductive layer needs to be thicker as the resistance value is reduced, and when the thickness of the conductive layer is increased, the problems of optical properties become prominent.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The present invention has been made to solve the above problems, and an object thereof is to provide a transparent conductive film excellent in both flexibility and optical properties.

Means for Solving the Problems

[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, wherein the transparent conductive laminate comprises a first transparent conductive layer made of a metal oxide and a second transparent conductive layer containing 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 arranged such that the second transparent conductive layer faces the substrate side. In one embodiment, the transparent conductive laminate is arranged such that the first transparent conductive layer faces the substrate side. 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 placed over a 2 mm diameter round rod 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 drawing]

[0008] [Figure 1] This is a schematic cross-sectional view of a transparent conductive film according to one embodiment of the present invention. [Figure 2] This is a schematic cross-sectional view of a transparent conductive film according to another embodiment of the present invention. [Figure 3] This is a schematic cross-sectional view of a transparent conductive film according to another embodiment of the present invention. [Modes for carrying out the invention]

[0009] A. Overall structure of the transparent conductive film Figure 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 substrate 10 and a transparent conductive laminate 20 disposed on at least one side of the substrate 10. The transparent conductive laminate 20 comprises 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 contains a metal nanostructure. The metal nanostructure may be, for example, a metal nanowire, a metal nanoparticle, etc. Although not shown, the transparent conductive film may further include any other suitable layers. For example, a hard coat layer may be disposed between the substrate and the transparent conductive laminate.

[0010] In one embodiment, as shown in Figure 1, the transparent conductive laminate 20 is arranged such 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 arranged in this order.

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

[0012] The transparent conductive laminate 20 may be arranged on both sides of the base material 10. For example, the following configurations can be given in which the transparent conductive laminate 20 is arranged on both sides of the base material 10. The configuration comprises the first transparent conductive layer 21, the second transparent conductive layer 22, the substrate 10, the second transparent conductive layer 22, and the first transparent conductive layer 21 in this order (Figure 3(a)). The configuration comprises the first transparent conductive layer 21, the second transparent conductive layer 22, the substrate 10, the first transparent conductive layer 21, and the second transparent conductive layer 22 in this order (Figure 3(b)). The configuration comprises the second transparent conductive layer 22, the first transparent conductive layer 21, the substrate 10, the second transparent conductive layer 22, and the first transparent conductive layer 21 in this order (Figure 3(c)). The configuration comprises the second transparent conductive layer 22, the first transparent conductive layer 21, the substrate 10, the first transparent conductive layer 21, and the second transparent conductive layer 22 in this order (Figure 3(d)).

[0013] In the present invention, by comprising a first transparent conductive layer composed of a metal oxide and a second transparent conductive layer containing a metal nanostructure, a transparent conductive film with excellent flexibility and optical properties can be obtained. More specifically, the transparent conductive film of the present invention, by comprising a second transparent conductive layer containing a metal nanostructure, can be made into a transparent conductive film with excellent flexibility and low resistance increase due to bending. Furthermore, conductive layers composed of metal nanostructures have the characteristic of being easy to reduce resistance, and therefore, in the present invention, by comprising a second transparent conductive layer, a transparent conductive film with excellent conductivity can be easily obtained. On the other hand, generally, conductive layers composed of metal nanostructures can adversely affect optical properties. For example, problems such as increased haze or the occurrence of metallic discoloration may occur. According to the present invention, by comprising 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 with excellent conductivity can be provided while suppressing deterioration of optical properties. Furthermore, by placing the first transparent conductive layer (metal oxide layer) on the outside of the second transparent conductive layer (metal nanostructure layer), corrosion of the metal nanostructure 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 by hanging it on a round bar with a diameter of 2 mm (preferably 1 mm), the increase rate of the surface resistance value (= surface resistance value after bending / surface resistance value before bending) is preferably 1.3 or less, more preferably 1.2 or less, and even more preferably 1.1 or less. It is preferable that the increase rate of the surface resistance value is within the above range regardless of which surface of the transparent conductive film is bent outward. Further, when the transparent conductive laminate is disposed on both sides of the base material, it is preferable that the surface resistance values on both surfaces are within the above range.

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

[0017] When the transparent conductive laminate is disposed on both sides of the base material, when it is bent by hanging it on a round bar with a diameter of 2 mm (preferably 1 mm), the increase rate of the surface resistance value on the transparent conductive laminate side on the outer side of the bending (= surface resistance value after bending / surface resistance value 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. Although the haze value is preferably smaller, the lower limit value 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. In particular, indium-tin composite oxide (ITO) is preferred. The metal oxide may also be a crystalline metal oxide. A crystalline metal oxide refers to a metal oxide obtained by heating (for example, heating to 120°C to 200°C) after forming a metal oxide film, as described later.

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

[0023] As a method for forming the first transparent conductive layer described above, for example, one method is to form a metal oxide layer by any suitable film deposition 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 it 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 described above is preferably 50 nm or less, and 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 described above is preferably 1 nm, and more preferably 5 nm.

[0025] The first transparent conductive layer described above may be patterned. Any appropriate method can be used for patterning, depending on the form of the conductive layer. For example, it can be patterned by etching, laser, etc. The shape of the pattern of the first transparent conductive layer can be any appropriate shape depending on the application. For example, the patterns described in Japanese Patent Publication No. 2011-511357, Japanese Patent Application Publication No. 2010-164938, Japanese Patent Application Publication No. 2008-310550, Japanese Patent Publication No. 2003-511799, and Japanese Patent Publication No. 2010-541109 can be cited.

[0026] C. Second transparent conductive layer As described above, the second transparent conductive layer contains metal nanostructures. Examples of metal nanostructures include metal nanowires, metal nanomesh, metal nanorods, metal nanotubes, metal nanopyramids, metal particles, or combinations thereof. Preferably, the second transparent conductive layer contains metal nanowires.

[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 the polymer matrix, the metal nanostructures are protected by the polymer matrix. As a result, corrosion of the metal nanostructures is prevented, and a more durable transparent conductive film can be obtained.

[0028] The thickness of the second transparent conductive layer is preferably 10 nm to 1000 nm, and more preferably 20 nm to 500 nm. If the second transparent conductive layer includes 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 patterning method can be employed depending on the form of the second transparent conductive layer. The shape of the pattern of the second transparent conductive layer can be any suitable shape depending on the application. For example, the patterns described in Japanese Patent Publication No. 2011-511357, Japanese Patent Application Publication No. 2010-164938, Japanese Patent Application Publication No. 2008-310550, Japanese Patent Publication No. 2003-511799, and Japanese Patent Publication No. 2010-541109 are examples. 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 described above is preferably 85% or more, more preferably 90% or more, and even more preferably 95% or more.

[0031] The above-mentioned metal nanowires refer to conductive materials that are made of metal, have a needle-like or thread-like shape, and a diameter of nanometers. Metal nanowires may be straight or curved. By using a second transparent conductive layer composed of metal nanowires, the metal nanowires form a mesh-like structure, allowing even a small amount of metal nanowires to form good electrical conduction paths, and thus enabling the creation of a transparent conductive film with low electrical resistance.

[0032] The ratio of the thickness d to the length L of the above-mentioned 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 large aspect ratio, the metal nanowires intersect well, and high conductivity can be achieved with a small amount of metal nanowire. As a result, a transparent conductive film with high light transmittance can be obtained. In this specification, "thickness of the metal nanowire" means the diameter if the cross-section of the metal nanowire is circular, the minor axis if it is elliptical, and the longest diagonal if it is polygonal. The thickness and length of the metal nanowire can be confirmed by scanning electron microscope or transmission electron microscope.

[0033] The thickness of the metal nanowire 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 nanowire is, for example, 10 nm.

[0034] The length of the above-mentioned metal nanowire is preferably 1 μm to 1000 μm, more preferably 1 μm to 500 μm, and particularly preferably 1 μm to 100 μm. 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 above-mentioned metal nanostructure (e.g., metal nanowire), as long as it is a highly conductive metal. Examples of metals constituting the above-mentioned metal nanostructure (e.g., metal nanowire) include silver, gold, platinum, copper, nickel, etc. Materials that have been plated (e.g., platinum plated) of these metals 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 manufacture the above-mentioned metal nanowires. For example, methods include reducing silver nitrate in solution, applying a voltage or current from the tip of a probe to the surface of a precursor, drawing out metal nanowires at 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. Silver nanowires of uniform size can be mass-produced according to methods such as those 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 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 described above. 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 copolymer (ABS); cellulose; silicone polymers; polyvinyl chloride; polyacetate; polynorbornene; synthetic rubber; and fluorine polymers. Preferably, a curable resin (preferably an ultraviolet-curable resin) composed of polyfunctional acrylates such as pentaerythritol triacrylate (PETA), neopentyl glycol diacrylate (NPGDA), dipentaerythritol hexaacrylate (DPHA), dipentaerythritol pentaacrylate (DPPA), and trimethylolpropane triacrylate (TMPTA) is used.

[0039] When the second transparent conductive layer is composed of a polymer matrix and the metal nanowire is a silver nanowire, the density of the second transparent conductive layer is preferably 1.0 g / cm³. 3 ~10.5g / cm 3 More preferably 1.0 g / cm³ 3 ~3.0g / cm 3 Within this range, a transparent conductive film with excellent conductivity and light transmittance can be obtained.

[0040] The second transparent conductive layer can be formed by applying a second conductive layer-forming composition 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 described above may contain a metal nanostructure (e.g., metal nanowire) and any suitable solvent. The second conductive layer-forming composition may be prepared as a dispersion of metal nanostructures (e.g., metal nanowire). 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 suitable additives depending on the purpose. Examples of the additives include corrosion inhibitors that prevent corrosion of metal nanostructures (e.g., metal nanowires) and surfactants that prevent aggregation of metal nanostructures (e.g., metal nanowires). The type, number, and amount of additives used may be appropriately set depending on the purpose.

[0042] If the second transparent conductive layer contains a polymer matrix, the polymer matrix may be formed by applying and drying the second conductive layer-forming composition as described above, then applying a polymer solution (polymer composition, monomer composition) onto a layer made of metal nanowires, and then drying or curing the polymer solution layer. Alternatively, the second transparent conductive layer may be formed using a second conductive layer-forming composition containing the polymer constituting the polymer matrix.

[0043] The dispersion concentration of metal nanowires in the above-mentioned second conductive layer forming composition is preferably 0.1% to 1% by weight. Within this range, a second transparent conductive layer with excellent conductivity and light transmittance can be formed.

[0044] Any suitable method can be used to apply the second conductive layer-forming composition described above. Examples of application methods include spray coating, bar coating, roll coating, die coating, inkjet coating, screen coating, dip coating, letterpress printing, intaglio printing, gravure printing, and the like. Any suitable drying method (e.g., natural drying, forced-air drying, heat drying) can be used to dry the coated layer. For example, in the case of heat drying, the drying temperature is typically 50°C to 200°C, preferably 80°C to 150°C. The drying time is typically 1 to 10 minutes.

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

[0046] The polymer solution may contain a solvent. Examples of solvents included in the polymer solution include alcohol-based solvents, ketone-based solvents, tetrahydrofuran, hydrocarbon-based solvents, or aromatic solvents. Preferably, the solvent is volatile. The boiling point of the solvent is preferably 200°C or lower, more preferably 150°C or lower, and even more preferably 100°C or lower.

[0047] D. Base material The above-mentioned substrate is typically composed of any suitable resin. Examples of resins that constitute the above-mentioned substrate include cycloolefin resins, polyimide resins, polyvinylidene chloride resins, polyvinyl chloride resins, polyethylene terephthalate resins, polyethylene naphthalate resins, and the like. Preferably, cycloolefin resins are used. By using a substrate composed of a cycloolefin resin, a transparent conductive film with excellent flexibility can be obtained.

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

[0049] The glass transition temperature of the resin constituting the above-mentioned substrate is preferably 50°C to 200°C, more preferably 60°C to 180°C, and even more preferably 70°C to 160°C. A substrate having a glass transition temperature within this range can prevent degradation when forming a transparent conductive laminate.

[0050] The thickness of the above-mentioned substrate is preferably 8 μm to 500 μm, more preferably 10 μm to 250 μm, even more preferably 10 μm to 150 μm, and particularly preferably 15 μm to 100 μm.

[0051] The tensile strength of the above-mentioned substrate is preferably 50 MPa or higher, more preferably 70 MPa or higher, and even more preferably 100 MPa or higher. Within this range, a transparent conductive film with particularly excellent flexibility can be obtained. The tensile strength can be measured at room temperature in accordance with JIS K 7161.

[0052] The total light transmittance of the above 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 as a transparent conductive film in touch panels and the like can be obtained.

[0053] The above-mentioned base material may further contain any suitable additives as needed. Specific examples of additives include plasticizers, heat stabilizers, light stabilizers, lubricants, antioxidants, UV absorbers, flame retardants, colorants, antistatic agents, compatibilizers, crosslinking agents, and thickeners. The type and amount of additives used may be appropriately determined depending on the purpose.

[0054] If necessary, various surface treatments may be performed on the above substrate. Any appropriate method can 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, the processability when coating with a transparent conductive layer-forming composition prepared with an aqueous solvent is improved. Furthermore, a transparent conductive film with excellent adhesion between the substrate and the transparent conductive layer can be obtained. [Examples]

[0055] The present invention will be specifically described below with reference to examples, but the present invention is not limited in any way to these examples. The evaluation methods in the examples and comparative examples are as follows.

[0056] (1) Initial resistance value Test specimens were obtained by applying Ag paste (1 cm long x 1 cm wide) to both longitudinal ends of a transparent conductive film (15 cm long x 1 cm wide) on the transparent conductive laminate side. Conductivity between the Ag pastes was confirmed with a tester, and the surface resistance value was measured.

[0057] (2) Resistance after bending A test specimen was obtained in the same manner as in (1) above. This test specimen was placed with the transparent conductive laminate side facing outwards on a stainless steel rod having the diameter specified in Table 1, and then bent 180° along the rod so that its longitudinal direction was curved. Next, weights (500g each) were attached to both ends in the longitudinal direction via clips, and this position was held for 10 seconds. After the above procedure, the copper clip was removed, the continuity between the Ag paste areas was checked 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 after bending / initial resistance value) to calculate the resistance increase rate.

[0059] [Manufacturing Example 1] (Manufacturing of metal nanowires) In a reaction vessel equipped with a stirring device, at 160°C, 5 ml of anhydrous ethylene glycol and 0.5 ml of anhydrous ethylene glycol solution of PtCl2 (concentration: 1.5 × 10⁻⁴ mol / L) were 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 over 6 minutes to the resulting solution. After this addition, the mixture was heated to 160°C and the reaction was carried out for more than 1 hour until AgNO₃ was completely reduced to produce 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 increased fivefold. The reaction mixture was then centrifuged (2000 rpm, 20 minutes) to obtain silver nanowires. A silver nanowire dispersion was prepared by dispersing the silver nanowire (concentration: 0.2 wt%) and pentaethylene glycol dodecyl ether (concentration: 0.1 wt%) in pure water.

[0060] [Example 1] (Preparation of transparent conductive layer-forming composition (PN)) A transparent conductive layer-forming composition (PN) with a solid content of 0.05% by weight was prepared by diluting the above silver nanowire dispersion with 25 parts by weight of pure water. (Preparation of monomer compositions) One part by weight of pentaerythritol triacrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., trade name "Viscote #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 of 1% by weight. (Fabrication 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, product name "ZEONOR®", thickness 40 μm) and dried. Furthermore, the monomer composition was applied on the PN coating layer, dried at 80°C for 1 minute, and then subjected to a 300 mJ / cm² test. 2 A second transparent conductive layer was formed by ultraviolet irradiation. Next, a first transparent conductive layer consisting of a 32 nm thick indium tin oxide layer was formed on the second transparent conductive layer by sputtering. The conductive film thus obtained was wound onto a plastic core to produce a conductive film roll. Subsequently, the conductive film roll was placed in an air-circulating oven and subjected to heat treatment 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 a 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," also manufactured by DIC Corporation. (Fabrication of transparent conductive film) A prepared resin composition solution was applied to one side of a substrate (polycycloolefin film (manufactured by Zeon Corporation, product name "ZEONOR®", thickness 40 μm), dried at 80°C for 1 minute, and immediately irradiated with ultraviolet light using an ozone-type high-pressure mercury lamp (UV intensity 180 mW / cm2, cumulative light amount: 230 mJ / cm2) to form a cured resin layer with a thickness of 1.0 μm. Next, a transparent conductive layer consisting of an indium tin oxide layer with a thickness of 50 nm was formed by sputtering. The conductive film thus obtained was wound onto a plastic core to produce a conductive film roll. Subsequently, the conductive film roll was placed in an air-circulating oven and heat-treated 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. The system comprises a substrate and a transparent conductive laminate disposed on at least one side of the substrate, The transparent conductive laminate comprises a first transparent conductive layer made of a metal oxide and a second transparent conductive layer containing a metal nanostructure. The base material is made of resin, The tensile breaking strength of the substrate is 50 MPa or more. The thickness of the substrate is 8 μm to 500 μm. The thickness of the first transparent conductive layer is 40 nm or less. The thickness of the second transparent conductive layer is 100 nm to 1000 nm. Transparent conductive film.

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 or 2, wherein the metal nanostructure is a metal nanowire.

4. The transparent conductive film according to any one of claims 1 to 3, wherein the transparent conductive laminate is arranged such that the second transparent conductive layer faces the substrate side.

5. The transparent conductive film according to any one of claims 1 to 3, wherein the transparent conductive laminate is arranged such that the first transparent conductive layer faces the substrate side.

6. A transparent conductive film according to any one of claims 1 to 5, wherein the surface resistance is 100 Ω / □ or less.

7. The transparent conductive film according to any one of claims 1 to 6, wherein the rate of increase in surface resistance (= surface resistance after bending / surface resistance before bending) when the transparent conductive film is bent over a round bar with a diameter of 2 mm is 1.3 or less.

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