JP2022143836A - Transparent electroconductive film - Google Patents

Abstract

To provide a transparent electroconductive film that comprises an electroconductive layer containing metal fibers but is unsusceptible to poor electroconductivity due to contact.SOLUTION: This transparent electroconductive film comprises a base material and a transparent electroconductive layer disposed on at least either side of the base material. The transparent electroconductive layer includes a polymer matrix and metal fibers present in the polymer matrix. The arithmetic average surface roughness Ra of the transparent electroconductive layer is 1.5 μm or more.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.

Further, as a transparent conductive film, a transparent conductive film having a conductive layer containing metal fibers made of silver, copper, or the like has been proposed. Such a transparent conductive film has an advantage of being excellent in flexibility. On the other hand, a conductive layer containing metal fibers has a low contact resistance, and a conductive film having the conductive layer has a problem that poor conductivity tends to occur during transportation, storage, and the like.

Japanese Patent Publication No. 2009-505358

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 has a conductive layer containing metal fibers and is less likely to cause poor conductivity due to contact. That's what it is.

The transparent conductive film of the present invention comprises a substrate and a transparent conductive layer disposed on at least one side of the substrate, the transparent conductive layer comprising a polymer matrix and metal fibers present in the polymer matrix. and the transparent conductive layer has an arithmetic mean surface roughness Ra of 1.5 μm or more.
In one embodiment, the metal fibers are metal nanowires.
In one embodiment, the metal nanowires are silver nanowires.
In one embodiment, the transparent conductive film further comprises a metal layer.
In one embodiment, the metal layer is composed of copper.
In one embodiment, the transparent conductive layer has a thickness of 50 nm to 300 nm.

ADVANTAGE OF THE INVENTION According to this invention, the transparent conductive film which the electroconductivity defect by a contact does not produce easily can be provided, having a conductive layer containing a metal fiber.

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.

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 layer 20 disposed on at least one side (both sides in the illustrated example) of the substrate 10 . Transparent conductive layer 20 includes a polymer matrix and metal fibers present in the polymer matrix. Although not shown, the transparent conductive film may further include any other suitable layers. In one embodiment, at least one outermost layer of the transparent conductive film is a transparent conductive layer.

2(a) and (b) are schematic cross-sectional views of a transparent conductive film according to another embodiment of the present invention. The transparent conductive film 200 has the transparent conductive layer 20 arranged only on one side of the substrate 10 . Transparent conductive film 300 further comprises metal layer 30 . In the example of FIG. 2B, the transparent conductive film 300 has the metal layer transparent conductive layer 20, the substrate 10, and the metal layer 30 arranged in this order.

In the present invention, the arithmetic mean surface roughness Ra of the transparent conductive layer is 1.5 μm or more. By setting the arithmetic mean surface roughness Ra of the transparent conductive layer within the above range, it is possible to obtain a transparent conductive film that is less likely to cause defective conduction even when contact with the transparent conductive layer occurs within such a range. Obtainable. When a conventional transparent conductive film is provided in the form of a roll, frictional force is applied to the surface by contact with each other, and when a transparent conductive layer containing metal fibers is provided, the metal fibers are separated from each other. poor conductivity is likely to occur. On the other hand, even when the transparent conductive film of the present invention is provided in the form of a roll, the bonding between the metal fibers is maintained and the desired conductivity is maintained. Moreover, even if the transparent conductive film is a single sheet, it is possible to prevent the metal fibers from coming off from each other due to contact, friction, or the like when the transparent conductive films are laminated. In addition, the transparent conductive film can exhibit excellent contact resistance not only for contact between transparent conductive films but also for contact with other articles. The arithmetic mean surface roughness Ra of the transparent conductive layer is preferably 2.0 μm to 5.0 μm, more preferably 3.0 μm to 4.0 μm, still more preferably 3.0 μm to 3.5 μm. . With such a range, the above effect becomes remarkable. Arithmetic mean surface roughness Ra can be measured using an atomic force microscope.

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.

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. Transparent Conductive Layer As noted above, the transparent conductive layer comprises metal fibers and a polymer matrix.

The thickness of the transparent conductive layer is preferably 50 nm to 300 nm, more preferably 80 nm to 200 nm. By setting the thickness of the transparent conductive layer to 50 nm or more, a transparent conductive layer having a small coefficient of dynamic friction can be formed.

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

The coefficient of dynamic friction of the transparent conductive layer with respect to the transparent conductive layer is preferably 2.0 or less, more preferably 1.8 or less, still more preferably 1.5 or less, and still more preferably 1.2 or less. , particularly preferably 1.0 or less, and most preferably 0.8 or less. It is preferable that the coefficient of dynamic friction of the transparent conductive layer with respect to the transparent conductive layer is as small as possible, but the lower limit is, for example, 0.05. Within such a range, it is possible to obtain a transparent conductive film in which poor conductivity is unlikely to occur even when contact with the transparent conductive layer occurs. The “dynamic friction coefficient of the transparent conductive layer with respect to the transparent conductive layer” means the dynamic friction coefficient between the transparent conductive layer of the transparent conductive film/the transparent conductive layer of the transparent conductive film and the transparent conductive layer of the same composition. In this specification, the coefficient of dynamic friction is measured according to JIS K7125:1999 with a measurement load of 100 g, a measurement speed of 1 mm/s, and a measurement distance of 30 mm.

In one embodiment, the coefficient of dynamic friction when the transparent conductive layer and the surface opposite to the transparent conductive layer are brought into contact is preferably 2.0 or less, more preferably 1.8 or less. , more preferably 1.5 or less, more preferably 1.2 or less, particularly preferably 1.0 or less, and most preferably 0.8 or less. The smaller the coefficient of dynamic friction when the transparent conductive layer and the surface opposite to the transparent conductive layer are brought into contact with each other, the better, but the lower limit is, for example, 0.05. “The surface opposite to the transparent conductive layer” means the outermost surface opposite to the surface of the transparent conductive layer to be measured with respect to the substrate. Therefore, when the transparent conductive film has a configuration of transparent conductive layer A/substrate/transparent conductive layer A, "when the transparent conductive layer is brought into contact with the surface opposite to the transparent conductive layer, "Dynamic friction coefficient" is the dynamic friction coefficient when the transparent conductive layers (transparent conductive layer A and transparent conductive layer A) are brought into contact with each other, and is synonymous with "dynamic friction coefficient of the transparent conductive layer with respect to the transparent conductive layer." In addition, when the transparent conductive film has a transparent conductive layer/substrate configuration, the "dynamic friction coefficient when the transparent conductive layer and the surface opposite to the transparent conductive layer are brought into contact" It is a dynamic friction coefficient when the conductive layer and the base material are brought into contact with each other. If the coefficient of dynamic friction when the transparent conductive layer is brought into contact with the surface opposite to the transparent conductive layer is within the above range, the transparent conductive film is laminated or the transparent conductive film is rolled. In this case, it is possible to remarkably prevent the occurrence of poor conduction.

In one embodiment, the transparent conductive layer is patterned. Any appropriate patterning method may be employed depending on the form of the transparent conductive layer. The shape of the pattern of the transparent conductive layer may be any suitable 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 transparent conductive layer is formed on the substrate, it can be patterned using any appropriate method depending on the form of the transparent conductive layer.

Metal nanowires can be preferably used as the metal fibers. 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. When a transparent conductive layer composed of metal nanowires is used, the metal nanowires form a network, and by joining them together, a good electrical conduction path can be formed, and a transparent conductive film with low electrical resistance can be obtained. be able to.

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 10 nm to 100 nm, most preferably 10 nm to 60 nm. Within such a range, a transparent conductive layer with high light transmittance can be formed.

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 constituting the metal nanowires as long as the metal has high conductivity. Examples of metals forming the metal nanowires include silver, gold, copper, and nickel. Also, materials obtained by subjecting these metals to plating (for example, gold plating) may be used. The metal nanowires are preferably composed of one or more metals selected from the group consisting of gold, platinum, silver and copper. In one embodiment, the metal nanowires are silver nanowires.

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, a method of applying voltage or current from the tip of a probe to the surface of a precursor, pulling out metal nanowires at the tip of the probe, and forming the metal nanowires continuously. . 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 nanowires in the transparent conductive layer is preferably 80% by weight or less with respect to the total weight of the transparent conductive layer. Within such a range, a transparent conductive layer having a small coefficient of dynamic friction can be formed. The content of the metal nanowires in the transparent conductive layer is more preferably 30 wt% to 75 wt%, more preferably 30 wt% to 65 wt%, still more preferably, relative to the total weight of the transparent conductive layer. is between 45% and 65% by weight. 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.

The density of the transparent conductive layer is preferably 1.3 g/cm ³ to 10.5 g/cm ³ , more preferably 1.5 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 transparent conductive layer is formed by applying a conductive layer-forming composition containing metal fibers (for example, metal nanowires) to the substrate (or a laminate of the substrate and other layers), and then drying the coated layer. can be formed. The conductive layer-forming composition may contain a resin material that forms a polymer matrix. Alternatively, a resin material that forms the polymer matrix is prepared separately from the conductive layer-forming composition, and after the conductive layer-forming composition is applied and dried, the resin material (polymer composition material, monomer composition) and then drying or curing the applied layer of the resin material to form a transparent conductive layer.

The conductive layer-forming composition may contain any appropriate solvent in addition to metal fibers (eg, metal nanowires). The conductive layer-forming composition may be prepared as a dispersion of metal fibers (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 conductive layer-forming composition may further contain any appropriate additive depending on the purpose. Examples of the additive include corrosion inhibitors that prevent corrosion of metal fibers (eg, metal nanowires), surfactants that prevent aggregation of metal fibers (eg, metal nanowires), and the like. The type, number and amount of additives used can be appropriately set according to the purpose.

The dispersion concentration of the metal fibers (for example, metal nanowires) in the conductive layer-forming composition is preferably 0.1% by weight to 1% by weight. Within such a range, a transparent conductive layer having excellent conductivity and light transmittance can be formed.

Any appropriate method can be adopted as a method for applying the composition for forming a conductive layer. 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.

C. 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. Cycloolefin resins are preferably 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 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.

D. Metal Layer The metal layer is composed of any suitable metal. Preferably, it is composed of a conductive metal such as silver, gold, copper, nickel, or the like. In one embodiment, the metal layer is composed of copper.

The metal layer can be formed by any appropriate method. The metal layer can be formed by a vapor deposition method, a sputtering method, a dry process (dry method) such as CVD, a wet process such as plating, or the like.

EXAMPLES The present invention will be specifically described below with reference to Examples, but the present invention is not limited to these Examples.

[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 over 6 minutes simultaneously. After this dropping, the solution was heated to 160° C. and reacted over 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 ink.

[Example 1]
The silver nanowire ink obtained in Production Example 1 was applied onto the base material (cycloolefin film) using a wire bar so that the specific resistance value after film formation was 50 Ω/□, and the coating was performed at 120° C. for 2 minutes. A film was formed by heating.
Furthermore, a photocurable resin mainly composed of urethane acrylate was mixed with a mixed solvent of isopropanol (IPA) and diacetone alcohol (DAA) (mixing ratio (by weight) IPA:DAA = 8:2) to a solid content concentration of 1.5. %, apply it to the silver nanowire ink coated surface using a spin coater so that the dry film thickness is 70 nm, heat at 80 ° C. for 1 minute, and then integrate with a high pressure mercury lamp. A transparent conductive layer A was formed by irradiating ultraviolet light with an exposure amount of 450 mJ/cm ² to obtain a transparent conductive film A consisting of a substrate/transparent conductive layer A.
The transparent conductive film A was subjected to the following evaluations.
(1) Dynamic friction coefficient for transparent conductive layer A Using the product name "TSf-503" manufactured by Kyowa Interface Science Co., Ltd., according to JIS K7125: 1999, the contact side sample (transparent conductive layer A) size: 1 cm square, The dynamic friction coefficient was measured by sliding the transparent conductive layers A against each other under the conditions of measurement load: 100 g, measurement speed: 1 mm/s, measurement distance: 30 mm, and measurement temperature: 23°C.
(2) Static friction coefficient Using the product name "TSf-503" manufactured by Kyowa Interface Chemical Co., Ltd., according to JIS K7125: 1999, the contact side sample (transparent conductive layer A) size: 1 cm square, measurement load: 100 g, The transparent conductive layer A and the transparent conductive layer A were slid under the conditions of measurement speed: 1 mm/s, measurement distance: 30 mm, and measurement temperature: 23° C., and the coefficient of friction (static friction coefficient) at the start of sliding was measured.
(3) Rate of Increase in Resistance Value The transparent conductive layers A were slid once at a distance of 3 cm under the same conditions as those for measuring the coefficient of dynamic friction except that the load was 300 g.
The surface resistance value of the transparent conductive layer was measured with a non-contact surface resistance measuring instrument (manufactured by NAPSON, trade name "EC-80", sheet resistance measurement mode, room temperature: 26°C) for the above-mentioned sliding portion and other portions. was measured using
The rate of increase in resistance value due to sliding was determined by the formula: (Surface resistance value of slidable portion/Surface resistance value of other than slidable portion).
(4) Arithmetic mean roughness Ra of transparent conductive layer A
Arithmetic mean roughness Ra in a 5 μm×5 μm region of the surface of the transparent conductive layer A was measured using a scanning probe microscope “Nanscope IV” AFM tapping mode manufactured by Veeco Instruments.

[Reference Example 1-1]
A transparent conductive film A was obtained in the same manner as in Example 1.
(1a) Dynamic Friction Coefficient with respect to Copper Film on Transparent Conductive Layer A Separately, in the same manner as in Example 1, a transparent conductive film A was obtained. A copper film having a thickness of 100 nm was formed by sputtering on the transparent conductive layer A of the obtained transparent conductive film A to obtain a transparent conductive film with a copper film. Using this transparent conductive film with a copper film as a sample on the contact side, the transparent conductive layer A and the copper film on the transparent conductive layer A are slid in the same manner as in (1) above, and the dynamic friction coefficient is measured. did.
(2a) Static Friction Coefficient Separately, in the same manner as in Example 1, a transparent conductive film A was obtained. A copper film having a thickness of 100 nm was formed by sputtering on the transparent conductive layer A of the obtained transparent conductive film A to obtain a transparent conductive film with a copper film. Using this transparent conductive film with a copper film as a sample on the contact side, the transparent conductive layer A and the copper film on the transparent conductive layer A are slid in the same manner as in (2) above, and the coefficient of friction at the start of sliding is determined. (Static friction coefficient) was measured.
(3a) Resistance value increase rate The transparent conductive layer A and the copper film on the transparent conductive layer A were slid in the same manner as in (3) above, and the resistance value increase rate due to sliding was measured.
(4a) Arithmetic mean roughness Ra of copper film on transparent conductive layer A
The arithmetic mean roughness Ra of the copper film on the transparent conductive layer A was measured in the same manner as in (4) above.

[Reference Example 1-2]
A transparent conductive film A was obtained in the same manner as in Example 1.
(1b) Coefficient of dynamic friction with respect to transparent conductive layer d The silver nanowire ink obtained in Production Example 1 is applied on a base material (cycloolefin film) using a wire bar, and the specific resistance value after film formation is 50Ω/□. and heated at 120° C. for 2 minutes to form a film.
Furthermore, a photocurable resin containing urethane acrylate as a main component is diluted with methyl isobutyl ketone to a solid content concentration of 1.5% to prepare a coating liquid a, and a spin coater is used to dry the silver nanowire ink coated surface. After coating to a thickness of 70 nm and heating at 80° C. for 1 minute, ultraviolet rays were irradiated with an integrated exposure amount of 450 mJ/cm ² with a high-pressure mercury lamp to form a transparent conductive layer d, substrate/transparent conductive layer. A transparent conductive film d consisting of d was obtained.
Using the transparent conductive film d as a sample on the contactor side, the dynamic friction coefficient was measured by sliding the transparent conductive layer A and the transparent conductive layer d in the same manner as in (1) above.
(2b) Static friction coefficient Using the transparent conductive film d as the sample on the contact side, the transparent conductive layer A and the transparent conductive layer d are slid in the same manner as in (2) above, and the coefficient of friction at the start of sliding (static friction coefficient) was measured.
(3b) Resistance value increase rate By the same method as in (3) above, the transparent conductive layer A and the transparent conductive layer d were caused to slide, and the resistance value increase rate due to sliding was measured.
(4b) Arithmetic mean roughness Ra of transparent conductive layer d
The arithmetic mean roughness Ra of the transparent conductive layer d was measured by the same method as in (4) above.

[Reference Example 1-3]
A transparent conductive film A was obtained in the same manner as in Example 1.
(1c) Dynamic Friction Coefficient for Cycloolefin Film A cycloolefin film (manufactured by Nippon Zeon Co., Ltd., trade name “ZF16”) was used as a sample on the contactor side, and the transparent conductive layer A and the cycloolefin film were treated in the same manner as in (1) above. and the dynamic friction coefficient was measured.
(2c) Coefficient of Static Friction Using a cycloolefin film (manufactured by Nippon Zeon Co., Ltd., trade name "ZF16") as a sample on the contactor side, slide the transparent conductive layer A and the cycloolefin film in the same manner as in (2) above. The friction coefficient (static friction coefficient) at the start of sliding was measured.
(3c) Resistance value increase rate The transparent conductive layer A and the cycloolefin film were slid in the same manner as in (3) above, and the resistance value increase rate due to sliding was measured.
(4c) Arithmetic mean roughness Ra of cycloolefin film
The arithmetic mean roughness Ra of the cycloolefin film was measured in the same manner as in (4) above.

[Reference Example 1-4]
A transparent conductive film A was obtained in the same manner as in Example 1.
(1d) Coefficient of dynamic friction against PET film A PET film (manufactured by KOLON industry, trade name “CE900”) is used as a sample on the contact side, and the transparent conductive layer A and the PET film are slid in the same manner as in (1) above. The dynamic friction coefficient was measured.
(2d) Coefficient of static friction Using a PET film (manufactured by KOLON industry, trade name "CE900") as a sample on the contactor side, the transparent conductive layer A and the PET film are slid in the same manner as in (2) above, The friction coefficient (static friction coefficient) at the start of sliding was measured.
(3d) Resistance value increase rate The transparent conductive layer A and the PET film were slid in the same manner as in (3) above, and the resistance value increase rate due to sliding was measured.
(4d) Arithmetic mean roughness Ra of PET film
The arithmetic mean roughness Ra of the PET film was measured in the same manner as in (4) above.

[Reference Example 1-5]
A transparent conductive film A was obtained in the same manner as in Example 1.
(1e) Coefficient of dynamic friction against acrylic film Using an acrylic film (manufactured by Toyo Kohan Co., Ltd., trade name "HX-40-UF") as a sample on the contactor side, the transparent conductive layer A and The coefficient of dynamic friction was measured by sliding on an acrylic film.
(2e) Static friction coefficient Using an acrylic film (manufactured by Toyo Kohan Co., Ltd., trade name "HX-40-UF") as a sample on the contactor side, the transparent conductive layer A and the acrylic film were formed in the same manner as in (2) above. was slid to measure the friction coefficient (static friction coefficient) at the start of sliding.
(3e) Resistance value increase rate The transparent conductive layer A and the acrylic film were slid in the same manner as in (3) above, and the resistance value increase rate due to sliding was measured.
(4e) Arithmetic mean roughness Ra of acrylic film
The arithmetic mean roughness Ra of the acrylic film was measured in the same manner as in (4) above.

[Example 2]
A transparent conductive film B consisting of a substrate/transparent conductive layer B was obtained in the same manner as in Example 1, except that the dry film thickness of the coating solution a was 100 nm.
Transparent conductive film B was subjected to the following evaluations.
(1B) Coefficient of dynamic friction with respect to transparent conductive layer B Using the product name "TSf-503" manufactured by Kyowa Interface Science Co., Ltd., according to JIS K7125: 1999, the contact side sample (transparent conductive layer B) size: 1 cm square, The dynamic friction coefficient was measured by sliding the transparent conductive layer B against the transparent conductive layer B under the conditions of measurement load: 100 g, measurement speed: 1 mm/s, measurement distance: 30 mm, and measurement temperature: 23°C.
(2B) Static friction coefficient Using the product name "TSf-503" manufactured by Kyowa Interface Science Co., Ltd., according to JIS K7125: 1999, the contact side sample (transparent conductive layer B) size: 1 cm square, measurement load: 100 g, The transparent conductive layer B and the transparent conductive layer B were slid under the conditions of measurement speed: 1 mm/s, measurement distance: 30 mm, and measurement temperature: 23° C., and the coefficient of friction (static friction coefficient) at the start of sliding was measured.
(3B) Rate of Increase in Resistance Value The transparent conductive layers B were slid once at a distance of 3 cm under the same conditions as those for measuring the coefficient of dynamic friction, except that the load was 300 g.
The surface resistance value of the transparent conductive layer was measured with a non-contact surface resistance measuring instrument (manufactured by NAPSON, trade name "EC-80", sheet resistance measurement mode, room temperature: 26°C) for the above-mentioned sliding portion and other portions. was measured using
The rate of increase in resistance value due to sliding was determined by the formula: (Surface resistance value of slidable portion/Surface resistance value of other than slidable portion).
(4B) Arithmetic mean roughness Ra of transparent conductive layer B
Arithmetic mean roughness Ra in a 5 μm×5 μm region of the surface of the transparent conductive layer B was measured using a scanning probe microscope “Nanoscope IV” AFM tapping mode manufactured by Veeco Instruments.

[Comparative Example 1]
A silver nanowire layer was formed in the same manner as in Example 1. Furthermore, a silane coupling agent is added to a photocurable resin containing urethane acrylate as a main component, and a coating liquid c is prepared by diluting with methyl isobutyl ketone to a solid content concentration of 1.5%. It was applied using a spin coater so that the dry film thickness was 70 nm, heated at 80° C. for 1 minute, and then irradiated with ultraviolet rays with an integrated exposure amount of 450 mJ/cm ² from a high-pressure mercury lamp to form a transparent conductive layer C. , a transparent conductive film C consisting of a base material/transparent conductive film C was obtained.
(1f) Dynamic Friction Coefficient with respect to Transparent Conductive Layer d Using the transparent conductive layer C as the sample on the contact side, the transparent conductive layer C and the transparent conductive layer C are slid in the same manner as in (1) above, and the dynamic friction coefficient is was measured.
(2g) Static friction coefficient Using the transparent conductive layer C as the sample on the contactor side, the transparent conductive layer c and the transparent conductive layer C are slid in the same manner as in (2) above, and the coefficient of friction at the start of sliding (static friction coefficient ) was measured.
(3g) Resistance value increase rate By the same method as in (3) above, the transparent conductive layer C and the cycloolefin film were slid, and the resistance value increase rate due to sliding was measured.
(4g) Arithmetic mean roughness Ra of transparent conductive layer d
The arithmetic mean roughness Ra of the transparent conductive layer C was measured in the same manner as in (4) above.

[Comparative Example 2]
A transparent conductive film d comprising a substrate/transparent conductive layer d was obtained in the same manner as described in Reference Example 1-2.
(1g) Dynamic Friction Coefficient with respect to Transparent Conductive Layer d Using the transparent conductive layer d as the sample on the contact side, the transparent conductive layer d and the transparent conductive layer d are slid in the same manner as in (1) above, and the dynamic friction coefficient is was measured.
(2g) Static friction coefficient Using the transparent conductive layer d as the sample on the contact side, the transparent conductive layer d and the transparent conductive layer d are slid in the same manner as in (2) above, and the coefficient of friction at the start of sliding (static friction coefficient ) was measured.
(3g) Resistance value increase rate By the same method as in (3) above, the transparent conductive layer d and the cycloolefin film were slid, and the resistance value increase rate due to sliding was measured.
(4g) Arithmetic mean roughness Ra of transparent conductive layer d
The arithmetic mean roughness Ra of the transparent conductive layer d was measured by the same method as in (4) above.

[Comparative Reference Example 2-1]
A transparent conductive film d was obtained in the same manner as in Comparative Example 2.
(1h) Dynamic Friction Coefficient with respect to Copper Film on Transparent Conductive Layer d Separately, in the same manner as in Comparative Example 2, a transparent conductive film d was obtained. A copper film having a thickness of 100 nm was formed by sputtering on the transparent conductive layer d of the obtained transparent conductive film d to obtain a transparent conductive film with a copper film. Using this transparent conductive film with a copper film as a sample on the contact side, the transparent conductive layer d and the copper film on the transparent conductive layer d are slid in the same manner as in (1) above, and the dynamic friction coefficient is measured. did.
(2h) Coefficient of Static Friction Using the transparent conductive film with the copper film as the sample on the contact side, the transparent conductive layer d and the copper film on the transparent conductive layer d are slid in the same manner as in (2) above. , the friction coefficient (static friction coefficient) at the start of sliding was measured.
(3h) Resistance value increase rate By the same method as in (3) above, the transparent conductive layer d and the copper film on the transparent conductive layer d were slid, and the resistance value increase rate due to sliding was measured.
(4h) Arithmetic mean roughness Ra of copper film on transparent conductive layer d
The arithmetic mean roughness Ra of the copper film on the transparent conductive layer d was measured by the same method as in (4) above.

Table 1 shows the evaluation results of the above Examples, Reference Examples, Comparative Examples, and Comparative Reference Examples. In addition, the sample on the side of the contact in terms of the coefficient of dynamic friction and rate of increase in resistance value is described as "the layer brought into contact with the transparent conductive layer" in the table.

As is clear from Table 1, according to the present invention, by specifying the arithmetic mean surface roughness Ra of the transparent conductive layer, it is possible to provide a transparent conductive layer that does not easily cause poor conductivity due to contact while having a conductive layer containing metal fibers. A conductive film can be provided. As shown in Reference Examples, such a transparent conductive film suppresses an increase in resistance value even when it is brought into contact with and slid on various films.

REFERENCE SIGNS LIST 10 base material 20 transparent conductive layer 30 metal layer 100, 200, 300 transparent conductive film

Claims (6)

comprising a substrate and a transparent conductive layer disposed on at least one side of the substrate;
wherein the transparent conductive layer comprises a polymer matrix and metal fibers present in the polymer matrix;
The arithmetic mean surface roughness Ra of the transparent conductive layer is 1.5 μm or more.
Transparent conductive film. The transparent conductive film according to claim 1, wherein the metal fibers are metal nanowires. 3. The transparent conductive film of claim 2, wherein the metal nanowires are silver nanowires. The transparent conductive film according to any one of claims 1 to 3, further comprising a metal layer. 5. The transparent conductive film of claim 4, wherein said metal layer is composed of copper. The transparent conductive film according to any one of claims 1 to 5, wherein the transparent conductive layer has a thickness of 50 nm to 300 nm.

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