JP2022122545A - transparent conductive film - Google Patents

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

The present invention relates to transparent conductive films.

Conventionally, 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 as a transparent conductive film used for touch sensor electrodes and the like. . However, the transparent conductive film having the metal oxide layer formed thereon has a problem that it has insufficient flexibility and cracks are likely to occur due to physical stress such as bending.

Moreover, as a transparent conductive film, a transparent conductive film having a conductive layer containing metal nanowires using silver, copper, or the like has been proposed. Such a transparent conductive film has an advantage of being excellent in flexibility. However, a conductive layer containing metal nanowires tends to have a high haze, and there is a problem from the viewpoint of optical properties, such as a tint derived from metal. As the resistance value of the conductive layer decreases, the thickness of the conductive layer needs to be increased.

Japanese Patent Publication No. 2009-505358

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.

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 being a first transparent conductive layer composed of a metal oxide. and a second transparent conductive layer including metal nanostructures.
In one embodiment, the metal oxide is an indium-tin composite oxide.
In one embodiment, the metal nanostructures are metal nanowires.
In one embodiment, the transparent conductive laminate is arranged such that the second transparent conductive layer faces the base material.
In one embodiment, the transparent conductive laminate is arranged such that the first transparent conductive layer faces the base material.
In one embodiment, the transparent conductive film has a surface resistance value of 100Ω/□ or less.
In one embodiment, the rate of increase in surface resistance when the transparent conductive film is hung on a round bar with a diameter of 2 mm and bent (=surface resistance after bending/surface resistance before bending) is 1.3 or less.

According to the present invention, it is possible to provide a transparent conductive film that is excellent in both flexibility and optical properties.

1 is a schematic cross-sectional view of a transparent conductive film according to one embodiment of the invention; FIG. 4 is a schematic cross-sectional view of a transparent conductive film according to another embodiment of the invention; FIG. 4 is a schematic cross-sectional view of a transparent conductive film according to another embodiment of the invention; FIG.

A. Overall Structure of Transparent Conductive Film FIG. 1 is a schematic 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 arranged 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 made of metal oxide. The second transparent conductive layer 22 includes metal nanostructures. Metal nanostructures can be, for example, metal nanowires, metal nanoparticles, and the like. Although not shown, the transparent conductive film may further include any other suitable layers. For example, a hard coat layer may be arranged between the substrate and the transparent conductive laminate.

In one embodiment, as shown in FIG. 1, the transparent conductive laminate 20 is arranged such that the second transparent conductive layer (metal nanostructure layer) 22 faces the substrate 10 side. 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.

FIG. 2 is a schematic cross-sectional view of a transparent conductive film according to another embodiment of the 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 side. 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.

The transparent conductive laminate 20 may be arranged on both sides of the substrate 10 . Examples of the configuration in which the transparent conductive laminate 20 is arranged on both sides of the substrate 10 include the following configuration.
A configuration comprising first transparent conductive layer 21/second transparent conductive layer 22/substrate 10/second transparent conductive layer 22/first transparent conductive layer 21 in this order (FIG. 3(a)).
A configuration comprising first transparent conductive layer 21/second transparent conductive layer 22/substrate 10/first transparent conductive layer 21/second transparent conductive layer 22 in this order (FIG. 3(b)).
A configuration comprising second transparent conductive layer 22/first transparent conductive layer 21/base material 10/second transparent conductive layer 22/first transparent conductive layer 21 in this order (FIG. 3(c)).
A configuration comprising second transparent conductive layer 22/first transparent conductive layer 21/substrate 10/first transparent conductive layer 21/second transparent conductive layer 22 in this order (FIG. 3(d)).

In the present invention, the first transparent conductive layer made of a metal oxide and the second transparent conductive layer containing a metal nanostructure are provided, so that the transparent conductive layer has excellent flexibility and optical properties. You can get a sex film. More specifically, the transparent conductive film of the present invention is provided with a second transparent conductive layer containing a metal nanostructure, so that it can be a transparent conductive film with excellent flexibility and little increase in resistance value due to bending. can. In addition, the conductive layer composed of metal nanostructures is characterized in that it is easy to reduce the resistance. Therefore, in the present invention, by providing the second transparent conductive layer, a transparent conductive film having excellent conductivity can be obtained. can be obtained easily. On the other hand, in general, conductive layers composed of metal nanostructures can adversely affect optical properties. For example, problems such as an increase in haze and generation of a tint derived from metal may occur. According to the present invention, by providing both the first transparent conductive layer composed of the metal oxide layer and the transparent conductive layer containing the metal nanostructure, the deterioration of the optical properties is suppressed and the conductivity is improved. An excellent transparent conductive film can be provided. Also, if the first transparent conductive layer (metal oxide layer) is arranged outside the second transparent conductive layer (metal nanostructure layer), corrosion of the metal nanostructure in the second transparent conductive layer can be prevented. be able to.

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

Rate of increase in surface resistance when the transparent conductive film of the present invention is hung on a round bar with a diameter of 2 mm (preferably 1 mm in diameter) and bent (=surface resistance after bending/surface resistance before bending). is preferably 1.3 or less, more preferably 1.2 or less, and still more preferably 1.1 or less. It is preferable that the rate of increase in the surface resistance value is within the above range even when the transparent conductive film is bent with any side facing outward. Moreover, when the transparent conductive laminate is arranged on both sides of the base material, the surface resistance values on both sides are preferably within the above range.

When the transparent conductive laminate is arranged on one side of the base material, the transparent conductive laminate side is bent while being hung on a round bar with a diameter of 2 mm (preferably 1 mm) with the transparent conductive laminate facing outward. The rate of increase in 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 still more preferably 1.1 or less. is.

When the transparent conductive laminate is arranged on both sides of the substrate, when it is bent over a round bar with a diameter of 2 mm (preferably 1 mm), the surface resistance value of the transparent conductive laminate side outside the bend is The rate of increase (=surface resistance value after bending/surface resistance value before bending) is preferably 1.3 or less, more preferably 1.2 or less, and still more preferably 1.1 or less.

The haze value of the transparent conductive film of the invention is preferably 1% or less, more preferably 0.7% or less, and even more preferably 0.5% or less. The haze value is preferably as small as possible, but its lower limit is, for example, 0.05%.

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

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, still more preferably 20 μm to 200 μm.

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 them, indium-tin composite oxide (ITO) is preferred. The metal oxide may be a crystallized metal oxide. A crystallized metal oxide means a metal oxide obtained by heating (for example, heating at 120° C. to 200° C.) after forming a metal oxide film, as will be described later.

The total light transmittance of the first transparent conductive layer is preferably 80% or more, more preferably 85% or more, still more preferably 90% or more.

As a method for forming the first transparent conductive layer, for example, any suitable film formation method (e.g., vacuum deposition method, sputtering method, CVD method, ion plating method, spray method, etc.) is used to form a metal oxide layer. to obtain the first transparent conductive layer. The metal oxide layer may be used as the first transparent conductive layer as it is, or may be further heated to crystallize the metal oxide. The temperature during the heating is, for example, 120°C to 200°C.

The thickness of the first transparent conductive layer is preferably 50 nm or less, more preferably 40 nm or less. Within such a 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.

The first transparent conductive layer may be patterned. Any appropriate patterning method may be employed depending on the form of the conductive layer. For example, it can be patterned by an etching method, a laser method, or the like. The shape of the pattern of the first transparent conductive layer can be any appropriate shape depending on the application. For example, patterns described in JP-A-2011-511357, JP-A-2010-164938, JP-A-2008-310550, JP-A-2003-511799, and JP-A-2010-541109 can be mentioned.

C. Second Transparent Conductive Layer As noted above, the second transparent conductive layer comprises metal nanostructures. Metal nanostructures include, for example, metal nanowires, metal nanomesh, metal nanorods, metal nanotubes, metal nanopyramids, metal particles, or combinations thereof. Preferably, the second transparent conductive layer comprises metal nanowires.

In one embodiment, the second transparent conductive layer further comprises a polymer matrix. In this embodiment, metal nanostructures (eg, metal nanowires) are present in the polymer matrix. In the second transparent conductive layer composed of a polymer matrix, the polymer matrix protects the metal nanostructures. As a result, corrosion of the metal nanostructure is prevented, and a transparent conductive film having superior durability can be obtained.

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.

In one embodiment, the second transparent conductive layer is patterned. Any appropriate patterning method may 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 appropriate shape depending on the application. For example, patterns described in JP-A-2011-511357, JP-A-2010-164938, JP-A-2008-310550, JP-A-2003-511799, and JP-A-2010-541109 can be mentioned. After the second transparent conductive layer is formed on the substrate, it can be patterned using any appropriate method depending on the form of the second transparent conductive layer.

The total light transmittance of the second transparent conductive layer is preferably 85% or more, more preferably 90% or more, still more preferably 95% or more.

The metal nanowire is a conductive material made of metal, needle-like or filamentous in shape, and having a diameter of nanometers. The metal nanowires may be straight or curved. If the second transparent conductive layer composed of metal nanowires is used, the metal nanowires form a mesh, so that even a small amount of metal nanowires can form a good electrical conduction path, and the electrical resistance A transparent conductive film with a small value can be obtained.

The ratio of the thickness d to the length L of the metal nanowires (aspect ratio: L/d) is preferably 10 to 100,000, more preferably 50 to 100,000, and particularly preferably 100 to 10,000. When metal nanowires having a large aspect ratio are used in this manner, the metal nanowires can cross each other satisfactorily, and a small amount of metal nanowires can 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” means the diameter when the cross section of the metal nanowire is circular, the minor axis when the metal nanowire is elliptical, and the polygonal In some cases it means the longest diagonal. The thickness and length of metal nanowires can be confirmed with a scanning electron microscope or a transmission electron microscope.

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 such a range, a second transparent conductive layer with high light transmittance can be formed. The lower limit of the thickness of metal nanowires is, for example, 10 nm.

The length of the metal nanowires is preferably 1 μm to 1000 μm, more preferably 1 μm to 500 μm, particularly preferably 1 μm to 100 μm. Within such a range, a transparent conductive film with high conductivity can be obtained.

Any appropriate metal can be used as the metal forming the metal nanostructure (for example, metal nanowire) as long as the metal has high conductivity. Examples of metals forming the metal nanostructures (eg, metal nanowires) include silver, gold, platinum, copper, and nickel. Also, materials obtained by subjecting these metals to plating (for example, platinum plating) may be used. The metal nanowires are preferably composed of one or more metals selected from the group consisting of silver, gold, platinum, copper and nickel, and one or more metals selected from the group consisting of silver, gold, platinum and copper. It is more preferable to be composed of a metal of

Any appropriate method can be adopted as a method for producing the metal nanowires. Examples include a method of reducing silver nitrate in a solution, and a method of continuously forming metal nanowires by applying voltage or current from the tip of the probe to the surface of the precursor, drawing out metal nanowires at the tip of the probe, and the like. . 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 are described, for example, in Xia, Y.; et al. , Chem. Mater. (2002), 14, 4736-4745; Xia, Y.; et al. , Nano letters (2003) 3(7), 955-960, mass production is possible.

The content of metal nanostructures (for example, metal nanowires) in the second transparent conductive layer is preferably 80% by weight or less, more preferably 70% by weight, based on the total weight of the second transparent conductive layer. % or less, more preferably 50% by weight or less. Within such a range, a transparent conductive film having excellent conductivity and light transmittance can be obtained.

Any appropriate polymer can be used as the polymer that constitutes the polymer matrix. Examples of the polymer include acrylic polymers; polyester polymers such as polyethylene terephthalate; aromatic polymers such as polystyrene, polyvinyltoluene, polyvinylxylene, polyimide, polyamide, and polyamideimide; polyurethane polymers; epoxy polymers; Polymer; acrylonitrile-butadiene-styrene copolymer (ABS); cellulose; silicon-based polymer; polyvinyl chloride; Preferably, polyfunctional compounds such as pentaerythritol triacrylate (PETA), neopentyl glycol diacrylate (NPGDA), dipentaerythritol hexaacrylate (DPHA), dipentaerythritol pentaacrylate (DPPA), trimethylolpropane triacrylate (TMPTA), etc. A curable resin composed of acrylate (preferably an ultraviolet curable resin) is used.

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 to 10.5 g/cm ³ . and more preferably 1.0 g/cm ³ to 3.0 g/cm ³ . Within such a range, a transparent conductive film having excellent conductivity and light transmittance can be obtained.

The second transparent conductive layer is formed by applying a second conductive layer-forming composition containing metal nanostructures (e.g., metal nanowires) to the substrate (or a laminate of the substrate and other layers), The coated layer can then be dried and formed.

The composition for forming the second conductive layer may contain metal nanostructures (for example, metal nanowires) and any appropriate solvent. The composition for forming the second conductive layer may be prepared as a dispersion of metal nanostructures (eg, metal nanowires). Examples of the solvent include water, alcohol solvents, ketone solvents, ether solvents, hydrocarbon solvents, aromatic solvents and the like. From the viewpoint of reducing environmental load, it is preferable to use water. The composition for forming the second conductive layer may further contain any appropriate additive depending on the purpose. Examples of the additive include corrosion inhibitors that prevent corrosion of metal nanostructures (eg, metal nanowires), surfactants that prevent aggregation of metal nanostructures (eg, metal nanowires), and the like. The type, number and amount of additives used can be appropriately set according to the purpose.

When the second transparent conductive layer contains a polymer matrix, the polymer matrix is coated on the layer composed of metal nanowires after the composition for forming the second conductive layer is applied and dried as described above. It can be formed by applying a polymer solution (polymer composition, monomer composition) 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.

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. Within such a range, a second transparent conductive layer having excellent conductivity and light transmittance can be formed.

Any appropriate method can be adopted as a method for applying the second conductive layer-forming composition. Examples of coating 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 (for example, natural drying, air drying, heat drying) may be employed as a drying method for the coating 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. Drying times are typically 1 to 10 minutes.

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

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, aromatic solvents, and the like. Preferably, the solvent is volatile. The boiling point of the solvent is preferably 200° C. or lower, more preferably 150° C. or lower, and still more preferably 100° C. or lower.

D. Substrate The substrate is typically composed of any suitable resin. Examples of the resin constituting the substrate include cycloolefin-based resin, polyimide-based resin, polyvinylidene chloride-based resin, polyvinyl chloride-based resin, polyethylene terephthalate-based resin, polyethylene naphthalate-based resin, and the like. Preferably, a cycloolefin resin is used. A transparent conductive film having excellent flexibility can be obtained by using a substrate composed of a cycloolefin resin.

Polynorbornene, for example, can be preferably used as the cycloolefin-based 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 products are commercially available as polynorbornene. Specific examples include the trade names “Zeonex” and “Zeonor” manufactured by Zeon Corporation, the trade name “Arton” manufactured by JSR Corporation, the trade name “Topas” manufactured by TICONA, and the trade name manufactured by Mitsui Chemicals. "APEL" may be mentioned.

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 still more preferably 70°C to 160°C. A substrate having a glass transition temperature within such a range can prevent deterioration during formation of a transparent conductive laminate.

The thickness of the 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.

The tensile strength at break of the substrate is preferably 50 MPa or higher, more preferably 70 MPa or higher, and still more preferably 100 MPa or higher. Within such a range, a transparent conductive film having particularly excellent flexibility can be obtained. The tensile strength at break can be measured according to JIS K 7161 at room temperature.

The total light transmittance of the substrate is preferably 80% or more, more preferably 85% or more, and particularly preferably 90% or more. Within such a range, a transparent conductive film suitable as a transparent conductive film provided in a touch panel or the like can be obtained.

The base material may further contain any appropriate additive as necessary. Specific examples of additives include plasticizers, heat stabilizers, light stabilizers, lubricants, antioxidants, UV absorbers, flame retardants, colorants, antistatic agents, compatibilizers, cross-linking agents, and thickeners. etc. The type and amount of additive used can be appropriately set according to the purpose.

Various surface treatments may be applied to the base material, if necessary. Any appropriate method is adopted for the surface treatment depending on the purpose. Examples include low-pressure plasma treatment, ultraviolet irradiation treatment, corona treatment, flame treatment, acid or alkali treatment. In one embodiment, the transparent substrate is surface-treated to make the transparent substrate surface hydrophilic. By making the base material hydrophilic, the workability is excellent when the composition for forming a transparent conductive layer prepared with an aqueous solvent is applied. Also, a transparent conductive film having excellent adhesion between the substrate and the transparent conductive layer can be obtained.

EXAMPLES The present invention will be specifically described below with reference to Examples, but the present invention is not limited to these Examples. Evaluation methods in Examples and Comparative Examples are as follows.

(1) Initial resistance value A test piece was obtained by applying Ag paste (each part, length 1 cm x width 1 cm) to both longitudinal ends of a transparent conductive film (length 15 cm x width 1 cm) on the transparent conductive laminate side. Conduction between Ag pastes was confirmed with a tester, and the surface resistance value was measured.

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

(3) Rate of increase in resistance value Calculated as rate of increase.

[Production Example 1]
(Production 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: 1.5×10 −4 mol/L) were added at 160°C. After 4 minutes, 2.5 ml of an anhydrous ethylene glycol solution of AgNO3 (concentration: 0.12 mol/l) and an anhydrous ethylene glycol solution of polyvinylpyrrolidone (MW: 55000) (concentration: 0.36 mol/l) were added to the resulting solution. l) 5 ml were added dropwise simultaneously over 6 minutes. After this dropping, the mixture was heated to 160° C. and reacted for more than 1 hour until AgNO ₃ 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 increased 5 times, and then the reaction mixture was centrifuged (2000 rpm, 20 minutes), A silver nanowire was obtained. 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.

[Example 1]
(Preparation of Composition for Forming Transparent Conductive Layer (PN))
25 parts by weight of the silver nanowire dispersion and 75 parts by weight of pure water were diluted to prepare a composition for forming a transparent conductive layer (PN) having a solid concentration of 0.05% by weight.
(Preparation of monomer composition)
1 part by weight of pentaerythritol triacrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., trade name "Viscoat #300"), 0.2 parts by weight of a photopolymerization initiator (manufactured by BASF, trade name "Irgacure 907"), and 80 parts by weight of isopropyl alcohol and 19 parts by weight of diacetone alcohol to obtain a monomer composition having a solid 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 (trade name “ZEONOR (registered trademark)”, manufactured by Nippon Zeon Co., Ltd., thickness 40 μm)) and dried. Furthermore, the above monomer composition is applied onto the coating layer of the composition for forming a transparent conductive layer (PN), dried at 80° C. for 1 minute, and then irradiated with ultraviolet rays of 300 mJ/cm ² to form a second transparent conductive layer. Next, on the second transparent conductive layer, a first transparent conductive layer made of an indium tin oxide layer with a thickness of 32 nm was formed by a sputtering method.The thus obtained conductive film was wound around a plastic core to produce a conductive film roll.Then, the conductive film roll was placed in an air circulation oven, and heat-treated at 140°C for 90 minutes to perform indium tin oxidation. A transparent conductive film having a surface resistance value of 45Ω/□ was produced by converting the material from amorphous to crystalline.

[Comparative Example 1]
(Formation of cured resin layer)
As materials for forming the cured resin layer, 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 were used. A mixed resin composition solution was prepared.
(Preparation of transparent conductive film)
The prepared resin composition solution was applied to one side of a substrate (polycycloolefin film (trade name “ZEONOR (registered trademark)” manufactured by Nippon Zeon Co., Ltd., thickness 40 μm), dried at 80 ° C. for 1 minute, and then Immediately thereafter, ultraviolet irradiation was performed with an ozone type high-pressure mercury lamp (UV intensity: 180 mW/cm2, integrated light quantity: 230 mJ/cm2) to form a cured resin layer with a thickness of 1.0 μm.Next, from an indium tin oxide layer with a thickness of 50 nm A transparent conductive layer was formed by a sputtering method.The conductive film thus obtained was wound around a plastic core to produce a conductive film roll.Then, the conductive film roll was exposed to air The film was placed in a circulating oven and heat-treated at 140° C. for 90 minutes to transform the indium tin oxide from amorphous to crystalline to produce a transparent conductive film with a surface resistance of 41Ω/□.

Reference Signs List 10 base material 20 transparent conductive laminate 21 first transparent conductive layer 22 second transparent conductive layer
100, 200 transparent conductive film

Claims (7)

comprising 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 composed of a metal oxide and a second transparent conductive layer comprising metal nanostructures,
Transparent conductive film. 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 nanostructures are metal nanowires. 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 base material. 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 base material. The transparent conductive film according to any one of claims 1 to 5, which has a surface resistance value of 100Ω/□ or less. The rate of increase in surface resistance when the transparent conductive film is hung on a round bar with a diameter of 2 mm and bent (=surface resistance after bending/surface resistance before bending) is 1.3 or less. The transparent conductive film according to any one of claims 1 to 6.

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