KR20230142601A - transparent conductive film - Google Patents

Abstract

A transparent conductive film is provided that has a conductive layer containing metal fibers and is unlikely to cause conductive defects due to contact. The transparent conductive film of the present invention includes a substrate and a transparent conductive layer disposed on at least one side of the substrate, wherein the transparent conductive layer includes a polymer matrix and metal fibers present in the polymer matrix, and the transparent conductive layer includes: The dynamic friction coefficient for the transparent conductive layer is 2.0 or less.

Description

transparent conductive film

The present invention relates to transparent conductive films.

Conventionally, as a transparent conductive film used for electrodes of touch sensors, etc., 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 on which the metal oxide layer is formed has a problem in that it has insufficient flexibility and is prone to cracks due to physical stress such as bending.

Additionally, as a transparent conductive film, a transparent conductive film provided with a conductive layer containing metal fibers made of silver, copper, etc. has been proposed. This transparent conductive film has the advantage of excellent flexibility. On the other hand, the conductive layer containing metal fiber has low contact resistance, and the conductive film including the conductive layer has a problem in that defects such as poor conductivity are likely to occur during transportation, storage, etc.

Japanese Patent Publication No. 2009-505358

The present invention was made to solve the above-described problems, and its purpose is to provide a transparent conductive film that is unlikely to cause conductive defects due to contact while having a conductive layer containing metal fibers.

The transparent conductive film of the present invention includes a substrate and a transparent conductive layer disposed on at least one side of the substrate, wherein the transparent conductive layer includes a polymer matrix and metal fibers present in the polymer matrix, and the transparent conductive layer includes: The dynamic friction coefficient for the transparent conductive layer is 2.0 or less.

In one embodiment, the metal fiber is a metal nanowire.

In one embodiment, the metal nanowire is a silver nanowire.

In one embodiment, the transparent conductive film further includes a metal layer.

In one embodiment, the metal layer is made of copper.

In one embodiment, the thickness of the transparent conductive layer is 50 nm to 300 nm.

According to the present invention, it is possible to provide a transparent conductive film that has a conductive layer containing metal fibers and is unlikely to cause conductivity defects due to contact.

1 is a schematic cross-sectional view of a transparent conductive film according to one embodiment of the present invention.
Figure 2 is a schematic cross-sectional view of a transparent conductive film according to another embodiment of the present invention.

A. Overall composition of transparent conductive film

1 is a schematic cross-sectional view of a transparent conductive film according to one embodiment of the present invention. The transparent conductive film 100 includes a substrate 10 and a transparent conductive layer 20 disposed on at least one side (both sides in the illustrated example) of the substrate 10. The 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 layer. In one embodiment, at least one outermost layer of the transparent conductive film is a transparent conductive layer.

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

The dynamic friction coefficient of the transparent conductive layer with respect to the transparent conductive layer is 2.0 or less. In the present invention, by setting the dynamic friction coefficient of the transparent conductive layer within the above range, it is possible to obtain a transparent conductive film in which conduction defects are unlikely to occur even when contact with the transparent conductive layer occurs. When conventional transparent conductive films are provided in the form of a roll, frictional force is applied to the surface by contact with each other, and when provided with a transparent conductive layer containing metal fibers, the bonding of the metal fibers is misaligned, resulting in conduction failure. It's easy to happen. On the other hand, even when the transparent conductive film of the present invention is provided in the form of a roll, bonding between metal fibers is maintained and desired conductivity is maintained. Furthermore, even if the transparent conductive film is a single wafer, it is possible to prevent bonding misalignment between metal fibers due to contact, friction, etc. when the transparent conductive film is 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 dynamic friction coefficient of the transparent conductive layer with respect to the transparent conductive layer is preferably 1.8 or less, more preferably 1.5 or less, further preferably 1.2 or less, particularly preferably 1.0 or less, and most preferably It is less than 0.8. The smaller the dynamic friction coefficient of the transparent conductive layer with respect to the transparent conductive layer, the more desirable it is, but the lower limit is, for example, 0.05. “The dynamic friction coefficient of the transparent conductive layer with respect to the transparent conductive layer” refers to the dynamic friction coefficient between the transparent conductive layer provided by the transparent conductive film/the transparent conductive layer provided by the transparent conductive film and the transparent conductive layer of the same composition. it means. In this specification, the dynamic friction coefficient 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 a transparent conductive layer is brought into contact with a surface opposite to the transparent conductive layer is preferably 2.0 or less, more preferably 1.8 or less, and even 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 dynamic friction coefficient when the transparent conductive layer is brought into contact with the surface opposite to the transparent conductive layer, the more preferable it is, but its lower limit is, for example, 0.05. “The surface on the opposite side to the transparent conductive layer” means the outermost surface on the opposite side to the surface of the transparent conductive layer to be measured, based on the base material. Therefore, when the transparent conductive film has a structure of transparent conductive layer A/substrate/transparent conductive layer A, “the dynamic friction coefficient when the transparent conductive layer is brought into contact with the surface opposite to the transparent conductive layer” is that of the transparent conductive layer. It is the dynamic friction coefficient when (transparent conductive layer A and transparent conductive layer A) are brought into contact with each other, and is the same as “the dynamic friction coefficient of the transparent conductive layer with respect to the transparent conductive layer.” In addition, when the transparent conductive film is composed of a transparent conductive layer/substrate, the “dynamic friction coefficient when the transparent conductive layer is brought into contact with the surface opposite to the transparent conductive layer” is the coefficient of friction when the transparent conductive layer and the substrate are brought into contact. This is the dynamic friction coefficient when: If the dynamic friction coefficient when the transparent conductive layer is brought into contact with the surface opposite to the transparent conductive layer is within the above range, conductivity failure occurs when transparent conductive films are laminated or when the transparent conductive film is in the form of a roll. Occurrence can be significantly prevented.

The surface resistance value 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/□, and particularly preferably 0.1 Ω/□ to 300 Ω/□. and most preferably 0.1Ω/□∼100Ω/□. In one embodiment, the surface resistance value of the transparent conductive film is 100 Ω/□ or less.

The haze value of the transparent conductive film of the present invention is preferably 1% or less, more preferably 0.7% or less, and still more preferably 0.5% or less. The smaller the haze value, the more preferable it is, but its lower limit is, for example, 0.05%.

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.

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 still more preferably 20 μm to 200 μm.

B. Transparent conductive layer

As above, the transparent conductive layer includes metal fibers and a polymer matrix.

The thickness of the transparent conductive layer is preferably 50 nm to 300 nm, and 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 with a small dynamic friction coefficient can be formed.

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

The arithmetic mean surface roughness Ra of the transparent conductive layer is preferably 1.5 μm or more, and more preferably 2.0 μm to 4.0 μm. Within this range, a transparent conductive layer with a small dynamic friction coefficient can be formed.

In one embodiment, the transparent conductive layer is patterned. As a patterning method, any appropriate method can be adopted depending on the form of the transparent conductive layer. The shape of the pattern of the transparent conductive layer may be any appropriate shape depending on the intended use. For example, Japanese Patent Publication No. 2011-511357, Japanese Patent Publication No. 2010-164938, Japanese Patent Publication No. 2008-310550, Japanese Patent Publication No. 2003-511799, and Japanese Patent Publication No. 2010-541109. There are patterns. After the transparent conductive layer is formed on the substrate, it can be patterned using any appropriate method, depending on the shape of the transparent conductive layer.

As the metal fiber, metal nanowire can be preferably used. The metal nanowire refers to a conductive material made of metal, shaped like a needle or thread, and having a nanometer-sized diameter. The metal nanowire may have a straight shape or a curved shape. When a transparent conductive layer made of metal nanowires is used, the metal nanowires are formed into a network shape, and by bonding them together, a good electrical conduction path can be formed, and a transparent conductive film with low electrical resistance can be obtained.

The ratio between the thickness d and the length L (aspect ratio: L/d) of the metal nanowire is preferably 10 to 100,000, more preferably 50 to 100,000, and particularly preferably 100 to 10,000. When metal nanowires with such a large aspect ratio are used, the metal nanowires intersect favorably, and high conductivity can be achieved with a small amount of metal nanowires. As a result, a transparent conductive film with high light transmittance can be obtained. In addition, in this specification, “thickness of a metal nanowire” means the diameter when the cross-section of the metal nanowire is circular, means the minor diameter when the cross-section of the metal nanowire is elliptical, and the longest diagonal when the cross-section of the metal nanowire is polygonal. means. The thickness and length of the metal nanowire can be confirmed using a scanning electron microscope or transmission electron microscope.

The thickness of the metal nanowire is preferably less than 500 nm, more preferably less than 200 nm, particularly preferably 10 nm to 100 nm, and most preferably 10 nm to 60 nm. Within this range, a transparent conductive layer with high light transmittance can be formed.

The length of the 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.

As the metal constituting the metal nanowire, any suitable metal can be used as long as it is a highly conductive metal. Examples of metals constituting the metal nanowire include silver, gold, copper, and nickel. Additionally, materials that have been subjected to plating treatment (for example, gold plating treatment) on these metals may be used. The metal nanowire is preferably made of at least one metal selected from the group consisting of gold, platinum, silver, and copper. In one embodiment, the metal nanowire is a silver nanowire.

As a method for producing the metal nanowire, any suitable method can be adopted. 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, drawing out a metal nanowire from the tip of the probe, and continuously forming the metal nanowire. there is. In the method of reducing silver nitrate in a 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 are described, for example, in Xia, Y. et al., Chem. Mass production is possible according to the method described in Mater. (2002), 14, 4736-4745, Xia, Y. et al., Nano letters (2003)3(7), 955-960.

The content ratio of metal nanowires in the transparent conductive layer is preferably 80% by weight or less based on the total weight of the transparent conductive layer. Within this range, a transparent conductive layer with a small dynamic friction coefficient can be formed. The content ratio of the metal nanowire in the transparent conductive layer is more preferably 30% by weight to 75% by weight, more preferably 30% by weight to 65% by weight, based on the total weight of the transparent conductive layer, More preferably, it is 45% by weight to 65% by weight. Within this range, a transparent conductive film excellent in conductivity and light transparency can be obtained.

As the polymer constituting the polymer matrix, any suitable polymer can be used. Examples of the polymer include acrylic polymer; Polyester-based polymers such as polyethylene terephthalate; aromatic polymers such as polystyrene, polyvinyl toluene, polyvinyl xylene, polyimide, polyamide, and polyamidoimide; polyurethane-based polymer; Epoxy-based polymer; polyolefin-based polymer; Acrylonitrile-butadiene-styrene copolymer (ABS); cellulose; silicone-based polymer; polyvinyl chloride; polyacetate; polynorbornene; synthetic rubber; Fluorine-based polymers, etc. can be mentioned. Preferably, pentaerythritol triacrylate (PETA), neopentyl glycol diacrylate (NPGDA), dipentaerythritol hexaacrylate (DPHA), dipentaerythritol pentaacrylate (DPPA), and trimethylolpropane triacrylate. A curable resin (preferably an ultraviolet curable resin) composed of a multifunctional acrylate such as (TMPTA) is used.

The density of the transparent conductive layer is preferably 1.3 g/cm3 to 10.5 g/cm3, and more preferably 1.5 g/cm3 to 3.0 g/cm3. Within this range, a transparent conductive film excellent in conductivity and light transparency can be obtained.

The transparent conductive layer is formed by applying a composition for forming a conductive layer containing metal fibers (e.g., metal nanowires) to a substrate (or a laminate of a substrate and other layers) and then drying the applied layer. can do. The composition for forming a conductive layer may contain a resin material that forms a polymer matrix. Alternatively, the resin material forming the polymer matrix is prepared separately from the composition for forming the conductive layer, the composition for forming the conductive layer is applied and dried, and then the resin material (polymer composition, monomer composition) is applied on the layer composed of metal fibers. may be applied, and then the applied layer of the resin material may be dried or cured to form a transparent conductive layer.

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

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

As a method of applying the composition for forming the conductive layer, any suitable method can be adopted. Examples of the application method include spray coating, bar coating, roll coating, die coating, inkjet coating, screen coating, dip coating, iron plate printing, intaglio printing, and gravure printing. As a drying method for the application layer, any suitable drying method (for example, natural drying, blow drying, heat drying) can be adopted. For example, in the case of heat drying, the drying temperature is typically 50°C to 200°C, and preferably 80°C to 150°C. Drying time is typically 1 to 10 minutes.

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

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

C. Description

The base material is typically made of any suitable resin. Examples of the resin constituting the base material include cycloolefin-based resin, polyimide-based resin, polyvinylidene chloride-based resin, polyvinyl chloride-based resin, polyethylene terephthalate-based resin, and polyethylene naphthalate-based resin. . Preferably, cycloolefin-based resin is used. By using a substrate made of cycloolefin-based resin, a transparent conductive film with excellent flexibility can be obtained.

As the cycloolefin resin, for example, polynorbornene can be preferably used. Polynorbornene refers to a (co)polymer obtained by using a norbornene-based monomer having a norbornene ring as part or all of the starting raw materials (monomers). As the polynorbornene, various products are commercially available. Specific examples include the brand names “Zeonex” and “Zeonor” manufactured by Nippon Zeon, the brand names “Arton” manufactured by JSR, the brand name “Topas” manufactured by TICONA, and the brand names “APEL” manufactured by Mitsui Chemicals. .

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. If the substrate has a glass transition temperature in this range, deterioration can be prevented when forming a transparent conductive laminate.

The thickness of the substrate is preferably 8 μm to 500 μm, more preferably 10 μm to 250 μm, further preferably 10 μm to 150 μm, and particularly preferably 15 μm to 100 μm.

The total light transmittance of the base material is preferably 80% or more, more preferably 85% or more, and particularly preferably 90% or more. Within this range, a transparent conductive film suitable as a transparent conductive film provided on a touch panel, etc. can be obtained.

The substrate may further include any suitable additives as needed. Specific examples of additives include plasticizers, heat stabilizers, light stabilizers, lubricants, antioxidants, ultraviolet absorbers, flame retardants, colorants, antistatic agents, compatibilizers, crosslinking agents, and thickeners. The type and amount of additives used can be appropriately set depending on the purpose.

If necessary, various surface treatments may be performed on the substrate. Any appropriate method is employed for 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. When the base material is made hydrophilic, processability is excellent when applying a composition for forming a transparent conductive layer prepared with an aqueous solvent. Additionally, a transparent conductive film with excellent adhesion between the substrate and the transparent conductive layer can be obtained.

D. Metal layer

The metal layer is comprised of any suitable metal. Preferably, it is made of conductive metal such as silver, gold, copper, or nickel. In one embodiment, the metal layer is comprised of copper.

The metal layer can be formed by any suitable method. The metal layer can be formed by a vapor deposition method, a sputtering method, a dry process such as CVD, or a wet process such as plating.

Example

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to these examples in any way.

[Production Example 1]

(Manufacture 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 an anhydrous ethylene glycol solution of PtCl2 (concentration: 1.5 x 10-4 mol/l) were added. 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 obtained solution. 5 ml was added dropwise simultaneously over 6 minutes. After this dropwise addition, it was heated to 160°C and a reaction was performed over 1 hour or more until AgNO ₃ was completely reduced, thereby producing a silver nanowire. Next, acetone was added to the reaction mixture containing the silver nanowires obtained as described above until the volume of the reaction mixture was 5 times, and then the reaction mixture was centrifuged (2000 rpm, 20 minutes) to obtain silver. Nanowires were obtained. Silver nanowire ink was prepared by dispersing the above-mentioned silver nanowires (concentration: 0.2% by weight) and pentaethylene glycol dodecyl ether (concentration: 0.1% by weight) in pure water.

[Example 1]

The silver nanowire ink obtained in Production Example 1 was applied onto the substrate (cycloolefin film) using a wire bar so that the resistivity value after film formation was 50 Ω/□, and the film was formed by heating at 120°C for 2 minutes.

In addition, photocurable resin containing urethane acrylate as the main ingredient was diluted to a solid content of 1.5% with a mixed solvent of isopropanol (IPA) and diacetone alcohol (DAA) (mixing ratio (by weight) IPA:DAA=8:2). Liquid a was prepared, applied to the surface coated with the silver nanowire ink 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 dose of 450 mJ/cm2 using a high-pressure mercury lamp. Thus, the transparent conductive layer A was formed, and the transparent conductive film A consisting of the base material/transparent conductive layer A was obtained.

Transparent conductive film A was subjected to the following evaluation.

(1) Dynamic friction coefficient for transparent conductive layer A

Using the product name "TSf-503" manufactured by Kyowa Kaimen Kagaku, in accordance with JIS K7125:1999, sample (transparent conductive layer A) size on the contact side: 1cm□, measurement load: 100g, measurement speed: 1mm/ Under the conditions of s, measurement distance: 30 mm, and measurement temperature: 23°C, transparent conductive layer A and transparent conductive layer A were slid and the dynamic friction coefficient was measured.

(2) Static friction coefficient

Using the product name "TSf-503" manufactured by Kyowa Kaimen Kagaku, in accordance with JIS K7125:1999, sample (transparent conductive layer A) size on the contact side: 1cm□, measurement load: 100g, measurement speed: 1mm/ Under the conditions of s, measurement distance: 30 mm, and measurement temperature: 23°C, transparent conductive layer A and transparent conductive layer A were slid, and the friction coefficient (static friction coefficient) of the slide was measured.

(3) Resistance value increase rate

Except that the load was 300 g, the transparent conductive layers A were slid against each other once at a distance of 3 cm under the conditions for measuring the dynamic friction coefficient.

For the sliding location and other locations, the surface resistance value of the transparent conductive layer was measured using a non-contact surface resistance meter (manufactured by NAPSON, brand name "EC-80", sheet resistance measurement mode, room temperature: 26°C). did.

The resistance value increase rate due to sliding was obtained by the equation (surface resistance value of the sliding portion/surface resistance value other than the sliding portion).

(4) Arithmetic average roughness Ra of transparent conductive layer A

The arithmetic mean roughness Ra in an area of 5 μm × 5 μm on the surface of the transparent conductive layer A was measured using a scanning probe microscope “NanoscopeIV” AFM tapping mode manufactured by Veeco Instruments.

[Reference Example 1-1]

In the same manner as in Example 1, transparent conductive film A was obtained.

(1a) Dynamic friction coefficient for the copper film on transparent conductive layer A

Separately, in the same manner as in Example 1, transparent conductive film A was obtained. On the transparent conductive layer A of the obtained transparent conductive film A, a copper film was formed by sputtering to a thickness of 100 nm, and a transparent conductive film with a copper film was obtained. This transparent conductive film with a copper film was used as a sample on the contact side, and the transparent conductive layer A and the copper film on the transparent conductive layer A were slid by the same method as (1) above, and the dynamic friction coefficient was measured.

(2a) Static friction coefficient

Separately, in the same manner as in Example 1, transparent conductive film A was obtained. On the transparent conductive layer A of the obtained transparent conductive film A, a copper film was formed by sputtering to a thickness of 100 nm, and a transparent conductive film with a copper film was obtained. The sample on the contact side is this transparent conductive film with a copper film, and the transparent conductive layer A and the copper film on the transparent conductive layer A are slid by the same method as (2) above, and the friction coefficient (static friction coefficient) of the slide is Measured.

(3a) Resistance value increase rate

By the same method as (3) above, the transparent conductive layer A and the copper film on the transparent conductive layer A were slid, and the resistance value increase rate due to sliding was measured.

(4a) Arithmetic average roughness Ra of the copper film on transparent conductive layer A

The arithmetic mean roughness Ra of the copper film on the transparent conductive layer A was measured by the same method as (4) above.

[Reference Example 1-2]

In the same manner as in Example 1, transparent conductive film A was obtained.

(1b) Dynamic friction coefficient for transparent conductive layer d

The silver nanowire ink obtained in Production Example 1 was applied onto the substrate (cycloolefin film) using a wire bar so that the resistivity value after film formation was 50 Ω/□, and the film was formed by heating at 120°C for 2 minutes.

In addition, a coating solution a was prepared by diluting a photocurable resin containing urethane acrylate as a main component to a solid concentration of 1.5% with methyl isobutyl ketone, and a dry film thickness of 70 nm was applied to the surface coated with the silver nanowire ink using a spin coater. After applying as much as possible and heating at 80°C for 1 minute, the transparent conductive layer d was formed by irradiating ultraviolet rays with a cumulative exposure dose of 450 mJ/cm2 using a high-pressure mercury lamp to obtain a transparent conductive film d consisting of the base material/transparent conductive layer d.

The sample on the contact side was the transparent conductive film d, the transparent conductive layer A and the transparent conductive layer d were slid by the same method as (1) above, and the dynamic friction coefficient was measured.

(2b) Static friction coefficient

The sample on the contact side was the transparent conductive film d, the transparent conductive layer A and the transparent conductive layer d were slid by the same method as (2) above, and the friction coefficient (static friction coefficient) of the slide was measured.

(3b) Resistance value increase rate

By the same method as (3) above, the transparent conductive layer A and the transparent conductive layer d were slid, and the resistance value increase rate due to sliding was measured.

(4b) Arithmetic average 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 (4) above.

[Reference Example 1-3]

In the same manner as in Example 1, transparent conductive film A was obtained.

(1c) Dynamic friction coefficient for cycloolefin film

The sample on the contact side was a cycloolefin film (manufactured by Nippon Zeon, brand name "ZF16"), the transparent conductive layer A and the cycloolefin film were slid by the same method as (1) above, and the dynamic friction coefficient was measured.

(2c) Static friction coefficient

The sample on the contact side was a cycloolefin film (manufactured by Nippon Zeon, brand name "ZF16"), the transparent conductive layer A and the cycloolefin film were slid in the same manner as in (2) above, and the friction coefficient (static friction) of the slide was determined. coefficient) was measured.

(3c) Resistance value increase rate

The transparent conductive layer A and the cycloolefin film were slid by the same method 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 by the same method as (4) above.

[Reference Example 1-4]

In the same manner as in Example 1, transparent conductive film A was obtained.

(1d) Dynamic friction coefficient for PET film

The sample on the contact side was a PET film (manufactured by KOLON Industries, brand name "CE900"), the transparent conductive layer A and the PET film were slid by the same method as (1) above, and the dynamic friction coefficient was measured.

(2d) Static friction coefficient

The sample on the contact side is a PET film (manufactured by KOLON Industries, brand name "CE900"), the transparent conductive layer A and the PET film are slid in the same manner as in (2) above, and the friction coefficient (static friction coefficient) of the slide is determined. was measured.

(3d) Resistance value increase rate

The transparent conductive layer A and the PET film were slid by the same method 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 by the same method as (4) above.

[Reference Example 1-5]

In the same manner as in Example 1, transparent conductive film A was obtained.

(1e) Dynamic friction coefficient for acrylic film

The sample on the contact side was an acrylic film (manufactured by Toyo Kohan, brand name "HX-40-UF"), the transparent conductive layer A and the acrylic film were slid by the same method as (1) above, and the dynamic friction coefficient was measured. did.

(2e) Static friction coefficient

The sample on the contact side was an acrylic film (manufactured by Toyo Kohan, brand name "HX-40-UF"), the transparent conductive layer A and the acrylic film were slid in the same manner as in (2) above, and the friction coefficient of the slide was determined ( coefficient of static friction) was measured.

(3e) Resistance value increase rate

The transparent conductive layer A and the acrylic film were slid by the same method 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 by the same method as (4) above.

[Example 2]

Transparent conductive film B consisting of base material/transparent conductive layer B was obtained in the same manner as in Example 1, except that the dry film thickness of coating liquid a was 100 nm.

Transparent conductive film B was subjected to the following evaluation.

(1B) Dynamic friction coefficient for transparent conductive layer B

Using the product name “TSf-503” manufactured by Kyowa Kaimen Kagaku, in accordance with JIS K7125:1999, sample (transparent conductive layer B) size on the contact side: 1 cm□, measurement load: 100 g, measurement speed: 1 mm/ Under the conditions of s, measurement distance: 30 mm, and measurement temperature: 23°C, transparent conductive layer B and transparent conductive layer B were slid and the dynamic friction coefficient was measured.

(2B) Static friction coefficient

Using the product name “TSf-503” manufactured by Kyowa Kaimen Kagaku, in accordance with JIS K7125:1999, sample (transparent conductive layer B) size on the contact side: 1 cm□, measurement load: 100 g, measurement speed: 1 mm/ s, measurement distance: 30 mm, measurement temperature: 23°C, transparent conductive layer B and transparent conductive layer B were slid, and the friction coefficient (static friction coefficient) of the slide was measured.

(3B) Resistance value increase rate

Except that the load was 300 g, the transparent conductive layers B were slid against each other once at a distance of 3 cm under the conditions for measuring the dynamic friction coefficient.

For the sliding locations and other locations, the surface resistance value of the transparent conductive layer was measured using a non-contact surface resistance meter (manufactured by NAPSON, brand name "EC-80", sheet resistance measurement mode, room temperature: 26°C). did.

The rate of increase in resistance value due to sliding was determined using the formula (surface resistance value at the sliding location/surface resistance value other than the sliding portion).

(4B) Arithmetic average roughness Ra of transparent conductive layer B

The arithmetic mean roughness Ra in an area of 5 μm × 5 μm on the surface of the transparent conductive layer B was measured using a scanning probe microscope “NanoscopeIV” AFM tapping mode manufactured by Veeco Instruments.

[Comparative Example 1]

As in Example 1, a silver nanowire layer was formed. Additionally, a silane coupling agent was added to a photocurable resin containing urethane acrylate as a main component, a coating solution c diluted with methyl isobutyl ketone to a solid content concentration of 1.5% was prepared, and a spin coater was applied to the silver nanowire ink application surface. It is applied so that the dry film thickness is 70 nm, heated at 80°C for 1 minute, and then irradiated with ultraviolet rays with a cumulative exposure dose of 450 mJ/cm2 using a high-pressure mercury lamp to form a transparent conductive layer C, and a transparent conductive film consisting of the base material/transparent conductive C is formed. I got a C.

(1f) Dynamic friction coefficient for transparent conductive layer C

The sample on the contact side was the transparent conductive layer C, the transparent conductive layer C and the transparent conductive layer C were slid by the same method as (1) above, and the dynamic friction coefficient was measured.

(2f) Static friction coefficient

The sample on the contact side was the transparent conductive layer C, and the transparent conductive layer C and transparent conductive layer C were slid by the same method as (2) above, and the friction coefficient (static friction coefficient) of the slide was measured.

(3f) Resistance value increase rate

The transparent conductive layer C and the cycloolefin film were slid by the same method as in (3) above, and the resistance value increase rate due to sliding was measured.

(4f) Arithmetic average roughness Ra of transparent conductive layer C

The arithmetic mean roughness Ra of the transparent conductive layer C was measured by the same method as (4) above.

[Comparative Example 2]

By the same method as that described in Reference Example 1-2, a transparent conductive film d consisting of the base material/transparent conductive layer d was obtained.

(1g) Dynamic friction coefficient for transparent conductive layer d

The sample on the contact side was the transparent conductive layer d, and the transparent conductive layer d and the transparent conductive layer d were slid by the same method as (1) above, and the dynamic friction coefficient was measured.

(2g) Static friction coefficient

The sample on the contact side was the transparent conductive layer d, and the transparent conductive layer d and the transparent conductive layer d were slid by the same method as (2) above, and the friction coefficient (static friction coefficient) of the slide was measured.

(3g) Resistance value increase rate

The transparent conductive layer d and the cycloolefin film were slid by the same method as in (3) above, and the resistance value increase rate due to sliding was measured.

(4g) Arithmetic average 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 (4) above.

[Comparative Reference Example 2-1]

In the same manner as Comparative Example 2, transparent conductive film d was obtained.

(1h) Dynamic friction coefficient for the copper film on the transparent conductive layer d

Separately, in the same manner as Comparative Example 2, a transparent conductive film d was obtained. A copper film was formed by sputtering on the transparent conductive layer d of the obtained transparent conductive film d to a thickness of 100 nm, thereby obtaining a transparent conductive film with a copper film. This transparent conductive film with a copper film was used as a sample on the contact side, and the transparent conductive layer d and the copper film on the transparent conductive layer d were slid by the same method as (1) above, and the dynamic friction coefficient was measured.

(2h) Static friction coefficient

The sample on the contact side is the transparent conductive film with the copper film, and the transparent conductive layer d and the copper film on the transparent conductive layer d are slid by the same method as (2) above, and the friction coefficient (static friction coefficient) of the slide is calculated as Measured.

(3h) Resistance value increase rate

By the same method as (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 average 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 (4) above.

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

As is clear from Table 1, according to the present invention, the dynamic friction coefficient of the transparent conductive layer with respect to the transparent conductive layer is set to 2.0 or less, so that conductive defects due to contact are unlikely to occur while providing a conductive layer containing metal fibers. A difficult transparent conductive film can be provided. As shown in the reference example, such a transparent conductive film suppresses an increase in resistance value even when it is slid in contact with various films, etc.

10: Description
20: Transparent conductive layer
30: metal layer
100, 200, 300: Transparent conductive film

Claims (6)

Equipped with a base material and a transparent conductive layer disposed on at least one side of the base material,
The transparent conductive layer includes a polymer matrix and metal fibers present in the polymer matrix,
A transparent conductive film wherein the dynamic friction coefficient of the transparent conductive layer with respect to the transparent conductive layer is 2.0 or less. According to claim 1,
A transparent conductive film wherein the metal fiber is a metal nanowire. According to claim 2,
A transparent conductive film wherein the metal nanowire is a silver nanowire. The method according to any one of claims 1 to 3,
A transparent conductive film further comprising a metal layer. According to claim 4,
A transparent conductive film wherein the metal layer is made of copper. The method according to any one of claims 1 to 5,
A transparent conductive film wherein the transparent conductive layer has a thickness of 50 nm to 300 nm.