TW202123257A - Method for manufacturing transparent electroconductive film - Google Patents

Abstract

Provided is a method for manufacturing a transparent electroconductive film that has low electroconductive anisotropy while including metal nanowires. This method for manufacturing a transparent electroconductive film includes: a coating step in which, while a long substrate is conveyed, the substrate is coated with a transparent-electroconductive-layer-forming composition that includes metal nanowires to form a coating layer; and a blowing step for blowing on the coating layer to dry the coating layer and form a transparent electroconductive layer on the substrate. The blowing in the blowing step includes blowing in a direction different from the conveying direction of the substrate as seen from the coating-layer-surface side of the substrate.

Description

Manufacturing method of transparent conductive film

The present invention relates to a method for manufacturing a transparent conductive film.

Previously, in an image display device with a touch sensor, as the electrode of the touch sensor, a metal oxide layer such as ITO (Indium Tin Composite Oxide) was formed on a transparent resin film to obtain the electrode. Transparent conductive film. However, the transparent conductive film provided with the metal oxide layer tends to lose conductivity due to bending, and there is a problem that it is difficult to use in applications requiring flexibility such as flexible displays.

On the other hand, as a transparent conductive film with high flexibility, a transparent conductive film containing a metal nanowire is known. Metallic nanowires are linear conductive materials with a diameter of nanometers. In a transparent conductive film containing metal nanowires, the metal nanowires are mesh-shaped, and a small amount of metal nanowires form a good electrical conduction path. In addition, openings are formed in the gaps of the meshes. To achieve higher light transmittance. On the other hand, since the metal nanowire is linear, it is easy to arrange it in a state of alignment. Therefore, there is a problem of conductive anisotropy in the transparent conductive film containing the metal nanowire. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Special Publication No. 2009-505358 [Patent Document 2] Japanese Patent No. 6199034

[The problem to be solved by the invention]

The present invention was made in order to solve the above-mentioned problems, and its object is to provide a method for manufacturing a transparent conductive film with small conductive anisotropy even when metal nanowires are included. [Technical means to solve the problem]

The manufacturing method of the transparent conductive film of the present invention is used to manufacture a transparent conductive film, the transparent conductive film is provided with a substrate and a transparent conductive layer arranged on one side of the substrate, and the transparent conductive film The manufacturing method includes: a coating step, one side of which conveys the elongated substrate, and one side of which is coated with a transparent conductive layer forming composition containing metal nanowires to form a coating layer; and an air blowing step, which Blowing the coating layer; and the blowing in the blowing step includes blowing in a direction different from the conveying direction of the substrate. In one embodiment, the air blowing in the air blowing step is performed in two or more directions. In one embodiment, the direction of air blowing in the air blowing step viewed from the side of the coating layer of the substrate includes the direction from the inner side in the width direction of the substrate to the outer sides in the width direction. In one embodiment, the direction of air blowing in the air blowing step viewed from the side of the coating layer of the substrate includes a direction from both outer sides in the width direction of the substrate toward the inner side in the width direction. In one embodiment, the air blowing in the air blowing step is spiral air blowing. [Effects of Invention]

According to the present invention, a method of manufacturing a transparent conductive film with small conductive anisotropy can be provided.

A. Summary of the manufacturing method of the transparent conductive film The manufacturing method of the transparent conductive film of the present invention includes: a coating step, which transports a long substrate on one side and coats the substrate with a metal nanowire The composition for forming a transparent conductive layer is used to form a coating layer; and an air blowing step of blowing air to the coating layer. According to the manufacturing method of the present invention, a transparent conductive film having a substrate and a transparent conductive layer arranged on one side of the substrate can be obtained. The manufacturing method of the present invention may also include any appropriate other steps in addition to the above-mentioned coating step and air blowing step. In one embodiment, the above-mentioned manufacturing method may further include a drying step of drying the coating layer after the air blowing step. In another embodiment, the air blowing step is a step for drying the coating layer, and the transparent conductive layer is formed through the air blowing step.

Typically, the substrate in the state of a roll is discharged and the substrate is conveyed, while the above-mentioned coating step and air blowing step (and other steps such as a drying step if necessary) are performed to form a substrate provided with a substrate and arranged on the substrate. An elongated transparent conductive film with a transparent conductive layer on one side. In one embodiment, the transparent conductive film is wound after being formed. In the present invention, the blowing in the blowing step includes blowing in a direction different from the conveying direction of the substrate. The so-called direction different from the conveying direction of the substrate includes the following concepts, namely: the conveying direction of the substrate is different from the conveying direction of the substrate when viewed from the coating layer side of the substrate, the direction not parallel to the surface of the substrate, and When viewed from the coating layer side of the substrate, it is a direction different from the conveying direction of the substrate and not parallel to the surface of the substrate. In one embodiment, the blowing direction that is different from the conveying direction of the substrate is a direction that is different from the conveying direction of the substrate when viewed from the coating layer side of the substrate, and is parallel or non-parallel to the surface of the substrate . In another embodiment, the air blowing in a direction different from the conveying direction of the substrate is different from the conveying direction of the substrate or approximately parallel to the conveying direction of the substrate when viewed from the coating layer side of the substrate. The direction is not parallel to the surface of the substrate. In addition, in this specification, the "non-parallel direction" means that the angle with respect to the direction/surface (substrate surface) used as a reference is 5ﾟ or less.

Fig. 1 (a) to (e) are schematic plan views illustrating the blowing direction in the blowing step of one embodiment of the present invention. Fig. 1 (a')-(e') is a schematic diagram illustrating the blowing direction in the blowing step of an embodiment of the present invention. Fig. 1(a') is a schematic front view of Fig. 1(a) (viewed from the winding side of the transparent conductive film), and Fig. 1(b') is a schematic front view of Fig. 1(b). Fig. 1(c') is a schematic side view of Fig. 1(c), and Fig. 1(d') is a schematic side view of Fig. 1(d). Fig. 1(e') is a schematic front view of Fig. 1(e).

In one embodiment, as shown in FIGS. 1(a) and (b), the blowing direction in the blowing step viewed from the side of the coating layer 21 of the substrate 10 is at least from the coating layer of the substrate When viewed from the side, it is a different direction from the conveying direction of the substrate, and the air blowing is performed in two or more directions.

In the embodiment shown in FIG. 1(a), the blowing direction (also referred to as the blowing direction X) in the blowing step viewed from the side of the coating layer 21 of the substrate 10 includes the width direction from the substrate 10 The two outer sides face the inner side of the width direction. In this embodiment, the angle formed by the conveying direction A of the substrate and the blowing direction X is greater than 0ﾟ but less than 180ﾟ, preferably 30ﾟ～150ﾟ, more preferably 60ﾟ～120ﾟ, more preferably It is 60ﾟ～100ﾟ, more preferably 60ﾟ～95ﾟ, still more preferably 75ﾟ～95ﾟ, particularly preferably 85ﾟ～95ﾟ. Furthermore, the wind from the outside in the width direction of the base material 10 toward the inside in the width direction can be blown in a fan shape.

In the embodiment shown in FIG. 1(b), the blowing direction (also referred to as the blowing direction X) in the blowing step viewed from the side of the coating layer 21 of the substrate 10 includes the width direction from the substrate 10 The direction from the inside to the outside in the width direction. In this embodiment, the angle formed by the conveying direction A of the substrate and the blowing direction X is greater than 0ﾟ but less than 180ﾟ, preferably 30ﾟ～150ﾟ, more preferably 60ﾟ～120ﾟ, more preferably It is 60ﾟ～100ﾟ, more preferably 60ﾟ～95ﾟ, still more preferably 75ﾟ～95ﾟ, particularly preferably 85ﾟ～95ﾟ. Furthermore, the wind from the inner side in the width direction of the base material 10 toward the outer side in the width direction can be blown in a fan shape.

As an embodiment in which air is blown in two or more directions, in addition to the form shown in Figure 1 (a) and (b), a spiral shape as shown in Figure 1 (c) and (d) can also be mentioned. The implementation mode of blowing (that is, flowing the wind as a spiral flow). In the case of spiral blowing, the direction X'of the spiral axis of the wind viewed from the surface of the coating layer 21 of the substrate 10 can be parallel to the conveying direction A of the substrate as shown in Fig. 1(c). It may not be parallel. In one embodiment, the angle formed by the direction X'of the spiral axis of the wind as viewed from the side of the coating layer 21 of the substrate 10 and the conveying direction A of the substrate is preferably 0-60, and more Preferably it is 0ﾟ～45ﾟ, particularly preferably it is 0ﾟ～30ﾟ. In another embodiment, the angle formed by the direction X'of the spiral axis of the wind viewed from the side of the coating layer 21 of the substrate 10 and the conveying direction A of the substrate is preferably 60~120ﾟ, More preferably, it is 80ﾟ～100ﾟ. Furthermore, in another embodiment, the angle formed by the direction X'of the spiral axis of the wind viewed from the side of the coating layer 21 of the substrate 10 and the conveying direction A of the substrate is preferably 120ﾟ～180ﾟ, more preferably 150ﾟ～180ﾟ. When the wind is blowing spirally, the direction Z'of the spiral axis of the wind viewed from the side of the substrate 10 may be parallel to the conveying direction A of the substrate (Figure 1(c')) or not . In one embodiment, the angle formed by the direction Z'of the spiral axis of the wind viewed from the side surface of the substrate 10 and the conveying direction A of the substrate is preferably 0-60, and more preferably 0ﾟ～30ﾟ. In another embodiment, the angle formed by the direction Z'of the spiral axis of the wind viewed from the side surface of the substrate 10 and the conveying direction A of the substrate is preferably 60~120, and more preferably 80ﾟ～100ﾟ (Figure 1(d')). Furthermore, in this specification, in order to distinguish from the spirally blowing wind, the wind as shown in Fig. 1 (a), (b) and (e) is not spiral but oriented substantially constant. The wind blowing in the direction is called the rectified wind.

In one embodiment, as shown in FIG. 1(e), the blowing direction in the blowing step viewed from the side of the coating layer 21 of the substrate 10 is a different direction from the conveying direction of the substrate, and This blowing is performed in one direction. In this embodiment, the angle formed by the conveying direction A of the substrate and the blowing direction X is greater than 0ﾟ but not 90ﾟ or more than 90 but not 180ﾟ, preferably 30ﾟ～60ﾟ or 120ﾟ～150ﾟ. Furthermore, the wind can blow in a fan shape.

When the rectified wind is blown toward the coating layer 21, the blowing direction Z in the blowing step viewed from the side of the substrate 10 can be parallel to the surface of the substrate (Figure 1(a') and (b')) , Or not parallel (Figure 1(e')). The angle formed by the blowing direction Z in the blowing step in the blowing step viewed from the side surface of the substrate 10 and the conveying direction A on the surface of the substrate is preferably 0-60. In one embodiment, the blowing direction Z in the blowing step viewed from the side of the substrate 10 is substantially parallel to the surface of the substrate (that is, the angle formed by the blowing direction Z and the surface of the substrate is 10 ﾟ or less). Thereby, a transparent conductive layer with excellent surface smoothness can be formed. In another embodiment, the angle formed by the blowing direction Z in the blowing step viewed from the side surface of the substrate 10 and the surface of the substrate is greater than 10ﾟ and less than 60ﾟ.

In the present invention, by setting the wind direction in the air blowing step to a specific direction, the alignment of the metal nanowires is disordered, and as a result, a transparent conductive film with small conductive anisotropy can be manufactured. This effect is more pronounced by blowing air in more than two directions. In addition, if air is blown in two or more directions, a transparent conductive film with remarkably high dispersion uniformity of metal nanowires can be obtained.

B. Coating step As described above, in the coating step, while conveying a long substrate, the substrate is coated with a transparent conductive layer forming composition containing metal nanowires to form a coating layer.

(Substrate) Any suitable material can be used for the material constituting the above-mentioned base material. Specifically, for example, a polymer substrate such as a film or a plastic substrate can be preferably used. This is due to the excellent wettability of the substrate smoothness and the composition for forming a transparent conductive layer, and the productivity can be greatly improved by continuous production using rollers.

The material constituting the above-mentioned substrate is typically a polymer film with a thermosetting resin as the main component. Examples of thermosetting resins include polyester resins, cycloolefin resins such as polynorbornene, acrylic resins, polycarbonate resins, and cellulose resins. Among them, polyester-based resins, cycloolefin-based resins, or acrylic resins are preferred. These resins are excellent in transparency, mechanical strength, thermal stability, and moisture barrier properties. The above-mentioned thermosetting resin may be used alone or in combination of two or more kinds. In addition, as an optical film used for a polarizing plate, for example, a low retardation substrate, a high retardation substrate, a retardation plate, a brightness enhancement film, etc. can also be used as a substrate.

The thickness of the aforementioned substrate is preferably 20 μm to 200 μm, more preferably 30 μm to 150 μm.

The total light transmittance of the substrate is preferably 30% or more, more preferably 35% or more, and particularly preferably 40% or more.

As the conveying method of the substrate, any suitable method can be adopted. For example, transportation by a transportation roller, transportation by a transportation belt, a combination of these, and the like can be cited. The transport speed is, for example, 5 m/min to 50 m/min.

(Metal Nanowire) The so-called metal nanowire is a conductive material whose material is metal, is needle-like or thread-like, and has a diameter of nanometers. Metal nanowires can be straight or curved. If a transparent conductive layer containing metal nanowires is used, the mesh-shaped metal nanowires can form a good electrical conduction path even with a small amount of metal nanowires, and a transparent conductivity with low resistance can be obtained. membrane. Furthermore, since the metal nanowire has a mesh shape and an opening is formed in the gap of the mesh, a transparent conductive film with high light transmittance can be obtained.

The ratio of the thickness d to 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. If such a metal nanowire with a large aspect ratio is used, the metal nanowire will cross well, and a small amount of metal nanowire can exhibit higher conductivity. As a result, a transparent conductive film with high light transmittance can be obtained. Furthermore, in this specification, the "thickness of the metal nanowire" refers to the diameter of the metal nanowire when the cross-section of the metal nanowire is round, and the short diameter when the cross section of the metal nanowire is elliptical. In the case of a polygon, it means the longest diagonal. The thickness and length of the metal nanowire can be confirmed with a scanning electron microscope or a 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 50 nm. If it is in such a 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 10 μm to 500 μm, and particularly preferably 10 μm to 100 μm. If it is such a 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 conductive metal. Examples of the metal constituting the metal nanowire include silver, gold, copper, nickel, and the like. In addition, materials that have been plated (for example, gold-plated) on these metals can also be used. Among them, silver, copper or gold is preferred from the viewpoint of conductivity, and silver is more preferred.

As the manufacturing method of the above-mentioned metal nanowire, any appropriate method can be adopted. For example, a method of reducing silver nitrate in a solution, and applying a voltage or current to the surface of the precursor from the front end of the probe, and draw a metal nanowire at the front end of the probe, and continuously form the metal nanometer. Line method, etc. In the method of reducing silver nitrate in solution, silver nanowires can be synthesized by reducing silver salts such as silver nitrate in a liquid phase in the presence of polyols such as ethylene glycol and polyvinylpyrrolidone. Uniform size silver nanowires, for example, can be based on Xia, Y. et al., Chem. Mater. (2002), 14, 4736-4745, Xia, Y. et al., Nano letters (2003) 3(7) , The method described in 955-960 and mass production.

(Composition for forming transparent conductive layer) The composition for forming a transparent conductive layer contains a metal nanowire. In one embodiment, a metal nanowire is dispersed in any suitable solvent to prepare a composition for forming a transparent conductive layer. Examples of the solvent include water, alcohol-based solvents, ketone-based solvents, aromatic ether-based solvents, hydrocarbon-based solvents, and aromatic-based solvents. In addition, the composition for forming a transparent conductive layer may further contain additives such as resin (binder resin), conductive materials other than metal nanowires (for example, conductive particles), and leveling agents. In addition, the composition for forming a transparent conductive layer may also contain a plasticizer, a heat stabilizer, a light stabilizer, a lubricant, an antioxidant, an ultraviolet absorber, a flame retardant, a colorant, an antistatic agent, a phase solvent, and a crosslinking agent. , Additives such as thickeners, inorganic particles, surfactants, and dispersants.

The viscosity of the composition for forming a transparent conductive layer is preferably 5 mP·s/25°C to 300 mP·s/25°C, more preferably 10 mP·s/25°C to 100 mP·s/25°C. If it is in such a range, the effect obtained by setting the wind direction in the air blowing step to a specific direction becomes greater. The viscosity of the composition for forming a transparent conductive layer can be measured by a rheometer (for example, MCR302 from Anton Paar).

The dispersion concentration of the metal nanowires in the composition for forming a transparent conductive layer is preferably 0.01% by weight to 5% by weight. If it is in such a range, the effect of the present invention is remarkable.

As the coating method of the composition for forming the transparent conductive layer, any appropriate method can be adopted. Examples of coating methods include spray coating, bar coating, roll coating, die coating, inkjet coating, screen coating, dip coating, relief printing, gravure printing, gravure printing, and the like.

The weight per unit area of the coating layer is preferably 0.3 g/m ² to 30 g/m ² , more preferably 1.6 g/m ² to 16 g/m ² . If it is in such a range, the metal nanowires can be well dispersed by the air blowing in the air blowing step, so that a transparent conductive film with less conductive anisotropy can be manufactured.

The film thickness of the coating layer is preferably 1 μm-50 μm, more preferably 2 μm-40 μm.

C. Air blowing step As described above, in the air blowing step, air is blown toward the coating layer side to set the alignment of the metal nanowires in the coating layer to a proper alignment. The direction of the air supply is as described in item A.

The air supply to the coating layer can be performed by any appropriate method. In one embodiment, a blower disposed above the coating layer (on the opposite side to the substrate) and/or on the side can be used to blow air toward the coating layer. Regarding the blowing direction, for example, a blind is installed on a blower, and it can be adjusted by the direction of the blind. In one embodiment, the blowing direction is specified by the opening direction of the shutter. In addition, in the case of sending out spiral wind, it can be used for a blower with a spiral wind direction plate at the air outlet.

The wind speed of the aforementioned wind is preferably 0.5 m/s to 10 m/s, more preferably 1 m/s to 5 m/s. If it is in such a range, the metal nanowires are well dispersed, and a transparent conductive film with smaller conductive anisotropy can be produced. In addition, a transparent conductive film excellent in surface smoothness and thickness uniformity can be obtained. The wind speed can be appropriately set according to the solvent and the like contained in the composition for forming a transparent conductive layer. In the case of using a composition for forming a transparent conductive layer prepared with water, the wind speed is preferably 0.5 m/s to 10 m/s, more preferably 1 m/s to 5 m/s. In addition, in this specification, the so-called wind speed means the wind speed at the point when it reaches the coating layer.

The temperature of the above-mentioned wind is preferably 10°C to 50°C, more preferably 15°C to 30°C. The wind speed can be appropriately set according to the solvent and the like contained in the composition for forming a transparent conductive layer. In the case of using a composition for forming a transparent conductive layer prepared with water, the temperature of the wind is preferably 10°C to 50°C, more preferably 15°C to 30°C. Furthermore, in this specification, the so-called wind temperature means the temperature of the wind at the point when it reaches the coating layer.

The blowing time is preferably 1 minute to 10 minutes, more preferably 2 minutes to 5 minutes. If it is in such a range, the metal nanowires are well dispersed, and a transparent conductive film with smaller conductive anisotropy can be produced. Specifically, if the area to be blown is determined so that the blowing time falls within the above-mentioned range, the metal nanowires can be appropriately dispersed in the entire coating layer, and a transparent conductive film with smaller conductive anisotropy can be produced. In addition, a transparent conductive film excellent in surface smoothness and thickness uniformity can be obtained.

In one embodiment, the above-mentioned air blowing is performed on the substrate (the substrate on which the coating layer is formed) on the transport roller. Thereby, the metal nanowires are well dispersed, and a transparent conductive film with smaller conductive anisotropy can be manufactured. In addition, a transparent conductive film excellent in surface smoothness and thickness uniformity can be obtained.

In the air supply step, the air supply can be divided into multiple stages. For example, it can be divided into different ways such as wind direction, wind speed, temperature, etc., and the air can be sent in stages. In addition, the thickness of the coating layer may be reduced by methods such as oven heating, natural drying, etc., before the air blowing step. The weight per unit area of the coating layer at the start of the air blowing step is preferably 0.001 g/m ² to 0.09 g/m ² , more preferably 0.005 g/m ² to 0.05 g/m ² .

Any appropriate treatment can be performed after the air supply step. For example, in the case of using a composition for forming a transparent conductive layer containing a binder resin, curing treatment by ultraviolet irradiation or the like can be performed. In addition, a drying step may be performed after the conveying step. As a drying method, oven heating, natural drying, etc. are mentioned, for example.

D. Transparent conductive film A transparent conductive film is formed by the above-mentioned manufacturing method. Fig. 2 is a schematic cross-sectional view of a transparent conductive film obtained by the manufacturing method of one embodiment of the present invention. The transparent conductive film 100 includes a substrate 10 and a transparent conductive layer 20 arranged on one side of the substrate 10.

The surface resistance of the transparent conductive film is preferably 0.1 Ω/□～1000 Ω/□, more preferably 0.5 Ω/□～300 Ω/□, especially preferably 1 Ω/□～200 Ω/□. The ratio (TD/MD) of the surface resistance value of the transparent conductive film in TD (direction orthogonal to MD) to the surface resistance value in MD (transport direction), preferably 0.7 to 1.5, more preferably 0.8 ～1.2, particularly preferably 0.9～1.1. The surface resistance value can be measured by the "Automatic resistivity measurement system MCP-S620 type·MCP-S521 type" of MITSUBISHI CHEMICAL ANALYTECH. The haze value of the transparent conductive film is preferably 20% or less, more preferably 10% or less, and particularly preferably 0.1% to 5%.

The total light transmittance of the transparent conductive film is preferably 30% or more, more preferably 35%, and particularly preferably 40% or more.

The weight per unit area of the transparent conductive layer is preferably 0.001 g/m ² to 0.09 g/m ² , more preferably 0.005 g/m ² to 0.05 g/m ² .

The content ratio of the metal nanowire in the transparent conductive layer is preferably 0.1 to 50 parts by weight, and more preferably 0.1 to 30 parts by weight relative to 100 parts by weight of the binder resin constituting the transparent conductive layer. If it is in such a range, a transparent conductive film excellent in conductivity and light transmittance can be obtained. [Example]

Hereinafter, the present invention will be specifically described with examples, but the present invention is not limited in any way by these examples. The evaluation methods of the examples are as follows. Regarding the thickness, the cross section was formed by cutting with an ultra-thin microtome after embedding with epoxy resin, and using a scanning electron microscope "S-4800" manufactured by Hitachi High-Technologies. And determined.

(1) Surface resistance value The surface resistance value of the transparent conductive film (surface resistance value of MD and TD) was measured by the eddy current method using a non-contact surface resistance tester made by NAPSON Co., Ltd., trade name "EC-80". The measurement temperature was 23°C.

[Manufacturing Example 1] Preparation of a composition for forming a transparent conductive layer Based on the method described in Chem. Mater. 2002, 14, 4736-4745, silver nanowires were synthesized. The silver nanowire obtained above was dispersed in pure water so that the concentration of the silver nanowire was 0.2% by weight and the concentration of dodecylpentaethylene glycol was 0.1% by weight, to obtain a composition for forming a transparent conductive layer.

[Example 1] A PET film (manufactured by Mitsubishi Plastics, trade name "S100") was used as the substrate. While transporting the substrate using a transfer roller, while using a bar coater (manufactured by Daiichi Science Co., Ltd., product name "bar coater No. 16"), the transparent conductive layer prepared in Production Example 1 The forming composition is coated on the substrate to form a ^{coating layer with a thickness per unit area of 0.015 g/m 2} and a wet film thickness of 15 μm. Thereafter, while conveying the substrate with the coating layer formed on one side, while sending out the rectified air to face the coating layer to dry the coating layer, a transparent conductive layer is formed, thereby obtaining a transparent conductive film with a substrate and a transparent conductive layer . As shown in Fig. 1(b), the air blowing is carried out from the center of the substrate toward both ends in the direction from the inner side to the both outer sides in the width direction. The angle formed by the lower blowing direction) is set to 90°, and the angle formed by the conveying direction A of the substrate and the blowing direction Z (the blowing direction viewed from the side of the coating layer) is set to 0ﾟ. In addition, the wind speed is set to 2 m/s, and the wind temperature is set to 25°C. In addition, the blowing time (drying time) was set to 2 minutes. The obtained transparent conductive film was provided to the above-mentioned evaluation (1). The results are shown in Table 1.

[Example 2] A conductive film was obtained in the same manner as in Example 1, except that the method of blowing air was performed in the direction from both outsides of the base material toward the inside in the width direction as shown in FIG. 1(a). The angle formed by the conveying direction A of the substrate and the blowing direction X (the blowing direction when viewed from the side of the coating layer) is set to 90ﾟ, the conveying direction A and the blowing direction Z of the substrate (when viewed from the side of the coating layer) The angle formed by the air supply direction) is set to 0ﾟ. In addition, the wind speed is set to 2 m/s, and the wind temperature is set to 25°C. In addition, the blowing time (drying time) was set to 2 minutes. The obtained transparent conductive film was provided to the above-mentioned evaluation (1). The results are shown in Table 1.

[Example 3] In the same manner as in Example 1, a coating layer was formed on the substrate. After that, while conveying the substrate with the coating layer formed on one side, while using a circulator to send a spiral flow to the coating layer to dry the coating layer to form a transparent conductive layer, a transparent conductive layer with a substrate and a transparent conductive layer is obtained.性膜。 The film. As shown in Figure 1(c) and (c'), the air supply is such that the direction X'of the spiral axis viewed from the coating layer side of the substrate is parallel to the conveying direction A of the substrate, and the self-base When viewed from the side of the material, the direction Z'of the spiral axis is parallel to the conveying direction A of the base material. The wind speed is set to 2 m/s, and the wind temperature is set to 25°C. In addition, the blowing time (drying time) was set to 2 minutes. The obtained transparent conductive film was provided to the above-mentioned evaluation (1). The results are shown in Table 1.

[Example 4] In the same manner as in Example 1, a coating layer was formed on the substrate. After that, while conveying the substrate with the coating layer, a circulator is used to send a spiral flow from above the coating layer to dry the coating layer to form a transparent conductive layer, thereby obtaining a transparent substrate and a transparent conductive layer. Conductive film. As shown in Figure 1(d) and (d'), the angle formed by the direction X'of the spiral axis and the conveying direction A of the substrate as viewed from the coating layer side of the substrate is set to 90ﾟ and get on. The wind speed is set to 2 m/s, and the wind temperature is set to 25°C. In addition, the blowing time (drying time) was set to 2 minutes. The obtained transparent conductive film was provided to the above-mentioned evaluation (1). The results are shown in Table 1.

[Example 5] Set the air supply method as shown in Figure 1(e), proceed from the left side of the substrate, and combine the transport direction A of the substrate and the air supply direction X (the air supply direction viewed from the side of the coating layer) The angle is set to 40ﾟ, and the angle formed by the conveying direction A of the substrate and the blowing direction Z (the blowing direction viewed from the side of the coating layer) is set to 0ﾟ. In addition, the wind speed is set to 2 m/s, and the wind temperature is set to 25°C. In addition, the blowing time (drying time) was set to 2 minutes. [Comparative Example 1] In the same manner as in Example 1, a coating layer was formed. Thereafter, the substrate on which the coating layer was formed was placed in an oven at an oven temperature of 100°C for 2 minutes to obtain a transparent conductive film. The obtained transparent conductive film was provided to the above-mentioned evaluation (1). The results are shown in Table 1.

[Table 1] Average resistance value (Ω) MD resistance value (Ω) TD resistance value (Ω) Anisotropy TD/MD Example 1 69.5 65 74 1.1 Example 2 65.5 59 72 1.2 Example 3 68 64 72 1.1 Example 4 67.5 65 70 1.1 Example 5 68 61 75 1.2 Comparative example 1 70 52 88 1.7

10: Substrate 20: Transparent conductive layer 21: Coating layer 100: Transparent conductive film A: The conveying direction of the substrate X, Z: air supply direction X', Z': the direction of the spiral axis

Fig. 1 (a) to (e) are schematic plan views illustrating the blowing direction in the blowing step of one embodiment of the present invention. (a') to (e') are schematic diagrams explaining the blowing direction in the blowing step of one embodiment of the present invention. Fig. 2 is a schematic cross-sectional view of a transparent conductive film obtained by the manufacturing method of one embodiment of the present invention.

10: Substrate

21: Coating layer

A: The conveying direction of the substrate

X, Z: air supply direction

X', Z': the direction of the spiral axis

Claims (6)

A method for manufacturing a transparent conductive film, which is used for manufacturing a transparent conductive film having a substrate and a transparent conductive layer arranged on one side of the substrate; and comprising: In the coating step, one side of the substrate is conveyed in a long strip shape, and the substrate is coated with a composition for forming a transparent conductive layer containing metal nanowires to form a coating layer; and The blowing step, which blows the coating layer; and The blowing in the blowing step includes blowing in a direction different from the conveying direction of the substrate. The method for manufacturing a transparent conductive film according to claim 1, wherein the air blowing in the air blowing step at least includes air blowing in a direction different from the conveying direction of the substrate when viewed from the coating layer side of the substrate. The method for manufacturing a transparent conductive film of claim 1 or 2, wherein the air blowing in the air blowing step is performed in two or more directions. The method of manufacturing a transparent conductive film according to claim 3, wherein the direction of air blowing in the air blowing step viewed from the side of the coating layer of the substrate includes the direction from the inner side in the width direction of the substrate to the outer sides in the width direction direction. The method for producing a transparent conductive film according to claim 3, wherein the direction of air blowing in the air blowing step viewed from the side of the coating layer of the substrate includes the direction from both outer sides in the width direction of the substrate toward the inner side in the width direction direction. The transparent conductive film of claim 1, wherein the air blowing in the air blowing step is spiral air blowing.

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