JP2012009239A - Method of producing conductive film and conductive film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of producing a flexible lightweight conductive film having a high optical transparency and exhibiting a low resistance and excellent uniformity of resistance even in case of a large area in which a wiring method of metal nanowire is simplified, and production cost of a conductive film can be reduced.SOLUTION: The method of producing a conductive film having a conductive pattern on a transparent substrate comprises: (a) a step of coating the surface of a transparent substrate with a dispersion containing conductive fibers and a conductive polymer, and (b) a step of forming a conductive pattern containing conductive fibers in a space formed between the transparent substrate and the recess of a mold by abutting the mold having a shape of regular protrusions and recesses against the surface of the transparent substrate from the dispersion side.

Description

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

Conventionally, as the transparent conductive film, various metal thin films such as gold, silver, platinum, copper, etc., indium oxide system doped with tin or zinc (ITO, IZO), zinc oxide system doped with aluminum or gallium (AZO, GZO), tin oxide-based (FTO, ATO) doped with fluorine or antimony, and the like are generally used. Moreover, the transparent conductive film is required to have a low resistance and a high transmittance. However, when a transparent conductive film is produced using the above conductive oxide, a transparent conductive film is formed by using a vacuum process such as a sputtering method. As a result, in addition to a decrease in light transmittance, problems such as an increase in cost occur, and there is a limit to reducing the resistance particularly on the film.
In recent years, as an improvement measure, metal nanowires, which are conductive materials that are transparent in the visible light region (400 nm to 700 nm), have been focused. Since the metal nanowire is conductive, a conductive layer can be formed by applying it to the surface of a substrate such as a film, so that the surface resistance of the substrate can be reduced. In addition, since the diameter of the metal nanowire is as small as 200 nm or less, the optical transparency in the visible light region is high, and by using the silver nanowire as the metal nanowire, it has good conductivity and transparency in combination with the original high conductivity of silver. It is expected to be applied as a transparent conductive film in place of a metal oxide film.

  In the case of linear metal nanowires, the conductive layer using metal nanowires is formed by applying a composition containing metal nanowires to the substrate surface, and the conductive network is formed by contact between metal nanowires. However, it is difficult to form a conductive network by being entangled well. Further, in order to prevent aggregation of the metal nanowires, the metal nanowires are coated with an organic substance such as a dispersant. After the metal nanowire-containing composition is applied to the surface of the substrate, annealing and pressing are performed. At present, contact between the nanowires is promoted to increase the conductivity (see, for example, Patent Document 1).

Here, regarding the conductive material other than the metal nanowire, in order to solve the above-described problem, various types of conductive and transparent materials that use a metal mesh having an opening as described below can be used. Methods have been proposed so far.
(1) Method of forming a conductive metal pattern using a silver salt photosensitive material Patent Document 2 forms a metal fine wire mesh pattern by exposing and developing a silver salt photosensitive layer provided on a transparent support. A method has been proposed.
(2) Method for pattern printing of conductive ink Patent Document 3 or 4 proposes a method for forming a mesh pattern by printing using a conductive ink containing metal fine particles. Further, in Patent Document 5, after forming a patterned nano ink layer made of metal nano ink containing conductive nanoparticles on a substrate by printing, a laser beam is irradiated around the patterned nano ink layer, and the pattern A method of forming a conductive pattern by fixing a nano ink layer on the surface of a substrate has been proposed.
(3) Method of pattern printing of conductive paste Patent Document 6 proposes a method of patterning a conductive paste containing conductive particles by screen printing or the like.
(4) Method of providing a network-like fine metal particle laminate structure on a base material Patent Document 7 discloses that a self-organizing metal fine particle solution is applied under specific conditions to a substrate having surface wetting tension under specific conditions. A method of forming a network-like metal fine particle multilayer structure on the substrate has been proposed.
With regard to the metal nanowires as well, it is possible to form a conductive layer having both conductivity and transparency by patterning the conductive portion as described above. For example, Patent Document 1 discloses a transparent electrode made of a fine mesh obtained by patterning silver nanowires. Patent Document 8 proposes a method of directly forming a conductive layer pattern by a printing method using silver nanowires. Further, Non-Patent Document 1 describes an example in which a silver nanowire mesh structure is formed on a film by using nanowire ink.

However, the above-described conventional technique has the following problems.
In Patent Document 1, particularly for a metal mesh using silver, both good conductivity and transparency can be achieved due to the inherent high conductivity of silver. However, although the metal mesh portion has high conductivity, since it has a mesh structure, there is a drawback that the portion that transmits light does not have conductivity.
Moreover, in patent document 8, since it is excellent in simple patterning property and continuous productivity by forming a pattern by the gravure printing method, it is possible to create a conductive film at low cost, but the characteristics of the nanowire are utilized. A fine pattern has not been formed, and a method for increasing the wiring density is not described in detail. Similarly, regarding Non-Patent Document 1, formation of a fine pattern has not been achieved.

JP 2009-505358 A JP 2010-003667 A JP 2009-016570 A JP 2009-140788 A JP 2010-043346 A JP 2009-176608 A JP 2009-016700 A JP 2010-073322 A

“Nikkei Electronics”, Nikkei BP, August 10, 2009, p. 64

  The present invention simplifies the wiring method of metal nanowires, can reduce the manufacturing cost of conductive films, has low resistance and excellent resistance uniformity even in a large area, has high light transmission, is lightweight. The present invention provides a method for producing a flexible conductive film and a conductive film obtained by this production method.

Such an object is achieved by the following present inventions (1) to (11).
(1) A method for producing a conductive film having a conductive pattern on a transparent substrate,
(A) a step of applying a dispersion containing conductive fibers and a conductive polymer on the surface of the transparent substrate, (b) a mold having a regular uneven shape is brought into contact with the transparent substrate surface from the dispersion side. Forming a conductive pattern containing conductive fibers in a space formed between the transparent substrate and the concave portion of the mold,
The manufacturing method of the electrically conductive film characterized by having.
(2) The convex part front-end | tip part which comprises the uneven | corrugated shape of the said casting_mold | template has a spire shape said (
The manufacturing method of the electrically conductive film as described in 1).
(3) The manufacturing method of the electrically conductive film as described in said (1) or (2) whose convex part front-end | tip part which comprises the uneven | corrugated shape of the said casting_mold | template consists of elastic bodies.
(4) The method for producing a conductive film according to (3), wherein the elastic body is a low surface energy polymer substance.
(5) The method for producing a conductive film according to (4), wherein the low surface energy polymer substance has a surface energy of 25 mJ / m ² or less.
(6) The method for producing a conductive film according to (4) or (5), wherein the low surface energy polymer substance is polydimethylsiloxane.
(7) In the step (b), (b) a mold having a regular concavo-convex shape is brought into contact with the surface of the transparent substrate from the dispersion side, and then the mold is further pressed to The method for producing a conductive film according to any one of the above (1) to (6), which is a step of forming a conductive pattern containing conductive fibers in a space formed between.
(8) The method for producing a conductive film according to any one of (1) to (7), wherein the conductive fiber is at least one selected from metal nanowires, carbon nanotubes, and carbon nanofibers.
(9) A conductive film produced by the production method described in any one of (1) to (8) above.
(10) The conductive film according to (9), wherein the conductive pattern has a width of a conductive pattern of 100 nm to 10 μm.
(11) The conductive film according to (9) or (10), wherein the conductive film has an adjacent conductive pattern interval of 1 to 100 μm.

According to the present invention, it is possible to easily and inexpensively produce a transparent conductive layer having a conductive pattern, low resistance, and high light transmittance on a transparent substrate.
According to the present invention, it is possible to provide a conductive film that can be preferably applied to various fields such as an organic light-emitting element, an inorganic electroluminescent element, a liquid crystal display element, electronic paper, a solar cell, an electromagnetic wave shield, and a touch panel, and a manufacturing method thereof.

It is the schematic (side sectional drawing) which shows arrangement | positioning of a casting_mold | template, a transparent base material, and a nanowire dispersion liquid. It is a conceptual diagram (side sectional view) when a mold is brought into contact with a transparent substrate. It is a conceptual diagram (side sectional view) when an elastic body is deformed by pushing a mold. It is a conceptual diagram (side sectional view) when the mold is further pushed. It is a conceptual diagram (side sectional view) when the nanowire dispersion liquid is heated. It is a conceptual diagram (side sectional view) when the mold is lifted from the transparent substrate. It is a conceptual diagram (side sectional view) when an elastic body returns to its original shape. It is a conceptual diagram (side sectional view) when the mold is separated from the transparent substrate. It is a conceptual diagram (side sectional view) when a conductive pattern is formed. It is an electron micrograph of the casting_mold | template used in the Example. It is an example of the laser micrograph of the electrically conductive film produced in the Example.

  Hereinafter, the present invention, its components, and modes for carrying out the present invention will be described in detail.

[Conductive fiber]
The conductive fiber used in the present invention is conductive and has a sufficiently long fiber length compared to the fiber diameter, and an aspect ratio (= fiber length / fiber) which is a ratio of the fiber length to the fiber diameter. The value of (diameter) is 10 or more, preferably 30 or more.
Examples of the conductive fibers include metal oxide fibers, metal nanowires, carbon nanotubes, and carbon nanofibers, and the forms include fibers, tubes, and the like. The conductive fiber used in the present invention preferably has a fiber diameter of 200 nm or less, and is preferably a conductive fiber containing at least one selected from metal nanowires, carbon nanotubes, and carbon nanofibers from the viewpoint of conductivity. In addition, when selecting from the group of metal nanowires, at least one metal belonging to the group consisting of noble metal elements (for example, gold, silver, platinum, palladium, rhodium, iridium, ruthenium, osmium) and iron, copper, cobalt, tin In view of conductivity and cost, metal nanowires composed of silver are more preferable.

[Conductive polymer]
The conductive polymer used in the present invention is not particularly limited, but a π-conjugated polymer is preferable. For example, polyazine, polyazulene, polyacetylene, polyacene, polyaniline, poly (isothianaphthene), polyindole , Polyethylenedioxythiophene, polycarbazole, polydiacetylene, polythiazyl, polythiophene, polypyridyl vinylin, polypyridazine, polypyrrole, poly (phenylacetylene), polyphenylene sulfide, polyfuran, poly (fluorene) , Poly (arylene ethynylene), poly (diacetylene), poly (thienylene vinylene), poly (paraphenylene) series, poly (paraphenylene oxide), poly (paraphenylene sulfide) series, poly (paraphenylene vinyl) Can be alkylene) system, a conductive polymer etc. may be utilized. Of these, polypyrrole, polyethylenedioxythiophene, and polyaniline are more preferable from the viewpoint of conductivity and transparency.

[Dispersion]
The dispersion used in the present invention contains at least one kind of the above-mentioned conductive fiber and conductive polymer.
The dispersion may contain a third component such as an additive as long as both conductivity and transparency are compatible. As the third component, for example, an antioxidant, a corrosion inhibitor, a viscosity modifier, a preservative, and the like can be contained.

(Transparent substrate)
Glass and plastic can be used as the transparent substrate used in the present invention.
Here, in the present invention, “transparent” means JIS K7361-1 (ISO 1346).
The total light transmittance in the visible light wavelength region is 70% or more measured by a method in accordance with “Plastic-Test method for total light transmittance of transparent material” in 8-1). There is no restriction | limiting in particular as a kind of base material, About the material, a shape, a structure, thickness, etc., it can select suitably from well-known things.
For example, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyester resin film such as modified polyester, polyethylene (PE) resin film, polypropylene (PP) resin film, polystyrene (PS) resin film, cyclic olefin resin, etc. Polyolefin resin films, vinyl resin films such as polyvinyl chloride and polyvinylidene chloride, polyether ether ketone (PEEK) resin films, polysulfone (PSF) resin films, polyether sulfone (PES) resin films, polycarbonate (PC ) Resin film, polyamide (PA) resin film, polyimide (PI) resin film, acrylic resin film, triacetyl cellulose (TAC) resin film, etc. However, when producing a conductive film using these transparent substrates, the conductive film according to the present invention is any resin film that has a total light transmittance of 80% or more in the visible wavelength (400 to 700 nm). It can be preferably applied to.
Among these, from the viewpoint of transparency, heat resistance, ease of handling, strength and cost, it is preferably a biaxially stretched polyethylene terephthalate film, a biaxially stretched polyethylene naphthalate film, a polyethersulfone film, or a polycarbonate film, and biaxially stretched. More preferred are polyethylene terephthalate films and biaxially stretched polyethylene naphthalate films.

〔template〕
The mold used in the present invention has a regular concavo-convex shape, and the tip of the convex portion preferably has a spire shape. The spire shape refers to all shapes with a sharp tip shape (top), and includes, for example, cone shapes such as a cone shape and a pyramid shape, and a V-shaped bowl-like continuum. Furthermore, the shape having a curved shape on the side surface may be used instead of a shape having a linear shape on the side surface such as a cone shape.
It is preferable that the convex part front-end | tip part which comprises the uneven | corrugated shape of the said casting_mold | template consists of an elastic body. Thereby, it can be deformed by applying a force, and a mechanism for discharging the dispersion at the time of deformation of the tip of the projection can be provided, so that the dispersion can be efficiently arranged in the recess of the mold. Furthermore, since it is an elastic body, it can return to its original shape when the pressing force is removed, so that the mold can be used again.
Moreover, it is preferable that the said elastic body is a low surface energy polymer substance which has a surface energy lower than the surface tension of the dispersion liquid containing a conductive fiber or a transparent base material. Specifically, the surface energy of a low surface energy polymeric material may have 40 mJ / ^{m 2} or less, preferably from 25 mJ / ^{m 2} or less. Thereby, when separating the mold from the transparent substrate, the structure formed between the mold and the transparent substrate can be prevented from adhering to the mold side, and the structure can be prevented from peeling off from the transparent substrate. be able to.
Examples of the polymer substance having such a low surface energy include acrylates, silicone materials, fluorinated epoxy resins, fluorinated thermoplastic elastomers, fluoroolefins, and the like. Among these, from the viewpoint of elastic properties, polydimethylsiloxane (PDMS: Polydimethylsiloxane) which is a silicone material is preferable.

[Method for producing conductive film]
The method for producing a conductive film of the present invention is a method for producing a conductive film having a conductive pattern on a transparent substrate,
(A) a step of applying a dispersion containing conductive fibers and a conductive polymer on the surface of the transparent substrate, (b) a mold having a regular uneven shape is brought into contact with the transparent substrate surface from the dispersion side. Forming a conductive pattern containing conductive fibers in a space formed between the transparent substrate and the concave portion of the mold,
It is characterized by having.

Hereinafter, the manufacturing method of a transparent conductive film is demonstrated using drawing. In the description, a case will be described in which nanowires are used as the conductive fibers and the tip of the convex portion of the mold is made of an elastic body having a quadrangular pyramid shape.
FIG. 1 is a schematic view showing the arrangement of a mold, a transparent substrate, and a nanowire dispersion. The nanowire dispersion liquid can be applied in advance by a method such as bar coating, and nanowires can be randomly arranged on the transparent substrate. The film thickness at the time of coating is determined by the shape and size of the mold. From the arrangement of FIG. 1, the mold is brought into contact with the mold (FIG. 2), and by applying pressure, the elastic body part having a spire shape provided at the tip of the convex part of the mold is slightly deformed, and the nanowire dispersion is transferred to the concave part of the mold. And selectively excreting (FIG. 3). After that, by further pressing, the elastic body portion provided at the tip of the convex portion of the mold is further deformed, and the nanowire dispersion is completely confined in the concave portion, thereby producing a nanowire structure (FIG. 4). After pressing, in some cases, heat treatment is performed to harden the nanowire structure (FIG. 5), and then the mold is gradually pulled up (FIGS. 6, 7, and 8) to form the nanowire structure on the transparent substrate. (FIG. 9). When the mold is pulled up, as shown in FIGS. 7 and 8, since the convex portion of the mold is an elastic body, the shape is self-restored and the mold can be used continuously. By using the above method, conductive fibers that were difficult to be placed in a predetermined position can be placed in a predetermined position by using the shape of the mold. The shape can be easily manufactured. Further, it is possible to pattern long fibers having a higher aspect ratio as compared with a mesh shape (see Patent Document 8 and Non-Patent Document 1) formed by using nanowire ink using a printing method.

[Transparent conductive layer]
In the conductive film provided by the present invention, the transparent conductive layer formed on the transparent substrate is composed of conductive fibers and a conductive polymer, and uses a dispersion containing the conductive fibers and the conductive polymer. A conductive fiber pattern is formed by a transfer printing method.
The transfer printing method used in the present invention can be classified into soft lithography, and a conventional micro transfer molding (μTM) method in which a concave portion formed in a mold is filled with a transfer material, and the filled transfer material is transferred onto a substrate. It is similar to In the conventional method, it has been difficult to selectively fill the concave portions of the mold with the conductive fibers used in the present invention. In the present invention, the conductive fiber can be selectively disposed in the concave portion of the mold by providing a mechanism for rejecting the conductive fiber at the tip of the convex portion of the mold.
Further, from the viewpoint of transparency, that is, light transmittance, it is preferable that the line width of the conductive pattern is narrow and the aperture ratio is large. Specifically, the line width is preferably in the range of 100 nm to 10 μm, preferably 10 μm or less, and more preferably 200 nm or less. The interval between adjacent conductive patterns is in the range of 1 to 100 μm, preferably 100 μm or less, and more preferably 50 μm or less. These sizes can be controlled by changing the pitch and line width of the concave portions of the mold.
When patterning continuously over a large area, it is possible to take a printing form, and transfer can be performed by using a roll elastic mold having a spire shape.

[Conductive film]
Next, the conductive film of the present invention will be described.
The conductive film of the present invention is manufactured by the above-described method for manufacturing a conductive film of the present invention.
The thickness of the conductive film of the present invention is not particularly limited and can be appropriately set depending on the purpose. In general, the conductive pattern forming portion is preferably 10 μm or less, and the thinner the thickness, the more transparent the conductive film is formed. It is more preferable because of improved properties.
70% or more is preferable and, as for the total light transmittance of the transparent conductive film of this invention, it is more preferable that it is 80% or more. The total light transmittance can be measured according to a known method using a spectrophotometer, a haze meter or the like.
The electrical resistance value in the transparent conductive film of the present invention is preferably 10 ⁴ Ω / □ or less, more preferably 10 ³ Ω / □ or less, and more preferably 10 ² Ω / □ or less as the surface resistivity. It is particularly preferred. The surface resistivity can be measured in accordance with, for example, JIS K6911, ASTM D257, IEC 60093, etc., and can also be easily measured using a commercially available surface resistivity meter.

Examples are given below to illustrate the present invention. However, the present invention is not limited to these.
1. Production of mold A pyramid-shaped body produced by cutting on a nickel alloy was converted into a polyethersulfone having a thickness of 0.5 mm (Sumilite FS-1300, manufactured by Sumitomo Bakelite Co., Ltd.,
Nanoimprint device for test (NanoimPro Type 510) on a substrate (abbreviated as PES)
, Manufactured by Nanonics Co., Ltd.) (250 ° C., 1 min).
Thereafter, PDMS (SYLGARD 184, manufactured by Toray Dow Corning Co., Ltd.) is poured onto the PES substrate on which the inverted pyramid-shaped body is formed, cured (80 ° C., 20 min), and then released to form a pyramid-shaped body. The obtained PDMS sheet was obtained and used as a mold.
The shape on the PDMS sheet was observed using a field emission scanning electron microscope (JSM-7401F, manufactured by JEOL Ltd.). The observation results are shown in FIG. The surface energy of the PDMS sheet was estimated by an automatic contact angle meter (DM-500, manufactured by Kyowa Interface Science Co., Ltd.) using a PDMS smooth surface portion where no mold was formed, and was 12.2 mJ / m ² . (For example, refer to the following document for the calculation method). In general, since the surface energy of the transparent substrate to be used is about 40 mJ / m ² , the structure formed between the mold and the transparent substrate is separated when the mold is separated from the transparent substrate in the present invention. It can be prevented from adhering to the mold side. (Reference: C.J. van
Oss, The Properties of Water and the Roll in Colloidal and Biological Systems, Interface Sci. Technol. , 2008, 16, p. 13-30. )

2. Production of Conductive Film <Example>
2.1 Preparation of conductive film α (1) Preparation of silver nanowire dispersion liquid Silver nanowire solution (Clear Ohm, manufactured by Cambrios Technologies Corp.) and polyethylenedioxythiophene / polyethylenedioxythiophene / polystyrenesulfonic acid, which is a conductive polymer of polyethylenedioxythiophene system (PEDOT: PSS, Clevio
s FE, H.M. C. Stark) and isopropyl alcohol were blended at a ratio of 1: 2: 1 and stirred to obtain a silver nanowire dispersion α. Moreover, the wire diameter of the used silver nanowire was about 100 nm, and the aspect-ratio was 90-350.
(2) Coating, pressing The obtained silver nanowire dispersion α was dropped onto a biaxially stretched polyethylene terephthalate (Cosmoshine A4100, manufactured by Toyobo Co., Ltd., hereinafter abbreviated as PET) film having a thickness of 100 μm. Was vacuum-adsorbed to the lower mold of the nanoimprint apparatus. The prepared mold was attached to the upper mold by vacuum suction. Moreover, the surface energy of the used PET film was 43.2 mJ / m ² . After attaching the film and the mold, pressing was performed by applying a pressure of 1.6 MPa using a nanoimprint apparatus. At that time, the moving speed of the workpiece was set to 0.005 mm · s ⁻¹ . Thereafter, the pressure was further increased to 2.3 MPa, and the upper mold and the lower mold were heated to 80 ° C. after pressurization (2 min). After a predetermined time, the film was cooled to room temperature and gradually depressurized to separate the conductive film and the mold.
(3) Drying Pressed, the PET film on which the conductive film was laminated was dried in a dryer at 110 ° C. (2 min), and the one taken out was used as the conductive film α.

<Comparative example>
2.2 Preparation of conductive film β As a comparative example, a dispersion β containing silver nanowires equivalent to the amount of silver nanowires contained in the silver nanowire dispersion α used in the conductive film α was prepared and applied without pressing. A conductive film β obtained when only the work is performed is prepared. The effectiveness of patterning is confirmed by comparing the conductive film α and the conductive film β according to the present invention.
(1) Preparation of silver nanowire dispersion liquid Silver nanowire dispersion liquid and diluent (ClearOhm Diluent-A AQ, manufactured by Cambrios Technologies Corp.) and isopropyl alcohol were mixed at a ratio of 1: 2: 1 and stirred to obtain a silver nanowire dispersion liquid β It was. The silver nanowire solution was the same as the silver nanowire dispersion α.
(2) Using a film applicator (MODEL 360, ERICHSEN) in which the coated silver nanowire dispersion β is attached on a PET film to a bar coater (K202 Control Coater, manufactured by RK Print Coat Instruments Ltd.), the wet film pressure is 60 μm. It was applied to become.
(3) The PET film coated with the dry silver nanowire dispersion β was dried in a dryer at 110 ° C. (2 min), and the taken-out was used as the conductive film β.

3. Evaluation Method of Conductive Film According to the following method, the transmittance and surface resistance of the conductive film were measured, and the results of surface observation were combined to evaluate the conductive film.
(1) Measurement of transmittance The transmittance was determined by measuring the light transmittance (%) of the conductive film portion at a light wavelength of 550 nm using an ultraviolet-visible spectrophotometer (UV-mini 1240, manufactured by Shimadzu Corporation).
(2) Measurement of surface resistance The surface resistance is measured by a four-terminal method using a surface resistance meter (RCHEK MODEL # RC2175, manufactured by Electronic Design to Market, Inc.). did. In addition, the measurement range of this surface resistance meter is 0-19990Ω / □.
(3) Observation of conductive film surface The surface of the conductive film was observed using a confocal laser microscope (VK-9710, manufactured by KEYENCE), and the size of the lattice was analyzed using analysis software (VK-Analyzer, manufactured by KEYENCE). Measured using.
4). Evaluation Results of Conductive Film Table 1 shows the evaluation results of the transparent conductive film obtained as described above. In addition, FIG. 11 shows the surface observation results of the manufactured conductive film.

According to the present invention, a transparent conductive film having the performance shown in Table 1 was obtained. In addition, FIG. 11 shows the results of observation of the conductive film α with a laser microscope. From this, it is confirmed that a silver nanowire / conductive polymer lattice pattern having a pattern width of 1.5 μm, a pattern interval of 13.5 μm, and a lattice portion height of 500 to 800 nm is obtained on the substrate. confirmed. Further, in the conductive film β with the same silver nanowire coating amount, the resistance value was not displayed by the used surface resistance meter (outside the measurement range). This is due to the lack of sufficient silver nanowires to form a silver nanowire network.
By performing the patterning as described above, it is possible to obtain performance required as a conductive film while suppressing the amount of silver nanowires used on the conductive film.

By the method for producing a conductive film of the present invention, a conductive film having low resistance and high transmittance and having a wiring pitch of 100 μm or less can be efficiently produced.
The conductive film obtained by the production method of the present invention can be usefully applied to a conductive film in which a fine line pattern is effective, such as a transparent conductive film for solar cells, an organic light emitting element, an inorganic electroluminescent element, and a liquid crystal display element. Is.

DESCRIPTION OF SYMBOLS 1 Template 2 Nanowire dispersion 3 Transparent base material 4 Elastic body 5 Conductive pattern 6 Hot plate

Claims (11)

A method for producing a conductive film having a conductive pattern on a transparent substrate,
(A) a step of applying a dispersion containing conductive fibers and a conductive polymer on the surface of the transparent substrate, (b) a mold having a regular uneven shape is brought into contact with the transparent substrate surface from the dispersion side. Forming a conductive pattern containing conductive fibers in a space formed between the transparent substrate and the concave portion of the mold,
The manufacturing method of the electrically conductive film characterized by having.   The method for producing a conductive film according to claim 1, wherein a tip end portion of the convex portion constituting the uneven shape of the mold has a spire shape.   The method for producing a conductive film according to claim 1 or 2, wherein a tip end portion of the convex portion constituting the concave-convex shape of the mold is made of an elastic body.   The method of manufacturing a conductive film according to claim 3, wherein the elastic body is a low surface energy polymer material. The method for producing a conductive film according to claim 4, wherein the low surface energy polymer substance has a surface energy of 25 mJ / m ² or less.   The method for manufacturing a conductive film according to claim 4, wherein the low surface energy polymer substance is polydimethylsiloxane. In the step (b), (b) a mold having a regular concavo-convex shape is brought into contact with the transparent substrate surface from the dispersion side, and then the mold is further pressed between the transparent substrate and the concave portion of the mold. 7. A step of forming a conductive pattern containing conductive fibers in the space to be formed.
The manufacturing method of the electrically conductive film as described in a term.   The method for producing a conductive film according to claim 1, wherein the conductive fiber is at least one selected from metal nanowires, carbon nanotubes, and carbon nanofibers.   A conductive film manufactured by the manufacturing method according to claim 1.   The conductive film according to claim 9, wherein the conductive pattern has a conductive pattern width of 100 nm to 10 μm.   The conductive film according to claim 9 or 10, wherein the conductive film has an adjacent conductive pattern interval of 1 to 100 µm.

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