JP2010165460A - Conductive nanofiber sheet and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a conductive nanofiber sheet with reduced pattern visibility and with a capability of forming a conductive pattern film with ease, and to provide a method of manufacturing the same. <P>SOLUTION: The conductive nanofiber sheet 1 includes a substrate sheet 10, a conductive pattern layer 6 formed on the substrate sheet 10, containing conductive nanofibers 3, capable of being conductive through the conductive nanofiber 3, and having a plurality of minute pinholes 7 which cannot be recognized by viewing, and an insulating pattern layer 5 formed on a part of the substrate sheet 10 where the conductive pattern layer 6 is not formed, containing the conductive nanofibers 3 and insulated from the conductive pattern layer 6. Narrow channels 9 disconnect the conductive nanofibers 3 which are in a conductive state, and the narrow channels 9 insulate the insulating pattern layer 5 from the conductive pattern layer 6. The narrow channels 9 and the minute pinholes 7 are filled with insulating materials. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a conductive nanofiber sheet used for a touch panel or the like and a method for producing the same.

  Conventionally, as a method for forming a layer made of nanofibers having a conductive layer on the surface of a base material made of resin, glass or the like, for example, as in Patent Document 1 below, a solution in which a binder resin is dissolved in a volatile solvent is extremely fine. There has been a method in which a coating liquid in which conductive fibers are dispersed is applied to the surface of a substrate, and this coating coating liquid is dried to form a conductive layer. However, the conductive nanofiber sheet obtained by the method as disclosed in Patent Document 1 has a problem that a pattern appears when a conductive layer is formed in a pattern. Therefore, in order to solve this problem, the inventors are a conductive nanofiber sheet in which a conductive pattern layer including a conductive nanofiber and an insulating pattern layer are formed on a base sheet, and the conductive pattern layer includes A conductive nanofiber sheet was invented in which a minute pinhole having a size that cannot be visually recognized was formed, and a narrow groove having a width that cannot be visually recognized was formed in the insulating pattern layer.

Japanese Patent No. 3903159

  However, if the conductive pattern layer (or insulating pattern layer) is made thick to obtain high conductivity, the depth of the minute pinholes and narrow grooves will increase, and the interior of the minute pinholes will illuminate when illuminated from an oblique angle. And shadows appear in narrow grooves and appear black. As a result, the difference in color and reflectivity from the conductive pattern layer (or insulating pattern layer) becomes remarkable, and even if it is configured with a size and width that cannot be recognized visually, minute pinholes and narrow grooves can be seen. In some cases, the pattern appearance did not disappear completely. Therefore, an attempt was made to solve this problem by making the size of the minute pinhole 7 and the width of the narrow groove 9 narrower. However, if the size of the minute pinhole 7 is made smaller or the width of the narrow groove 9 is made more delicate. The more it was done, the more difficult it was to pattern and there was a problem that productivity was lowered.

  The present invention has been made to solve the above-described problems. A conductive pattern layer containing conductive nanofibers and an insulating pattern layer are formed on a base sheet, and the width in which the insulating pattern layer cannot be visually recognized. The conductive nanofiber sheet is formed in an island-like structure by narrow grooves, and a part or all of the depth of the narrow grooves is filled with an insulating material. Moreover, this invention is good also as an electroconductive nanofiber sheet | seat whose depth of the narrow groove filled with the insulating material is 0-1 micrometer. Or it is good also as an electroconductive nanofiber sheet | seat whose thickness of the conductive pattern layer containing an electroconductive nanofiber and an insulating pattern layer is 1-5 micrometers.

  Moreover, this invention is a conductive nanofiber sheet in which a conductive pattern layer containing conductive nanofibers and an insulating pattern layer are formed of a photocurable material.

  In the present invention, a conductive pattern layer including conductive nanofibers is formed on the entire surface of the substrate sheet, a part of the conductive pattern layer is cured by light exposure, and a part of the uncured conductive pattern layer is developed and removed. Thus, after forming a narrow groove having a width that cannot be visually recognized and forming an insulating pattern layer on a portion surrounded by the narrow groove, the conductive nanofiber sheet is manufactured by applying an insulating material to the narrow groove. Further, a conductive pattern layer containing conductive nanofibers is formed on the entire surface of the substrate sheet, and a portion of the conductive pattern layer is irradiated with energy rays to burn off and remove a portion of the conductive pattern layer. After forming a narrow groove with a width that cannot be recognized in the above and forming a portion surrounded by the narrow groove as an insulating pattern layer, a method of manufacturing a conductive nanofiber sheet in which an insulating material is applied to the narrow groove may be used. Alternatively, in the present invention, a conductive pattern layer including conductive nanofibers is formed on the entire surface of the base sheet, an etching resist layer is formed on a part of the conductive pattern layer, and then the entire surface is etched to form an etching resist layer. By etching away a part of the conductive pattern layer that has not been formed, a narrow groove with a width that cannot be visually recognized is formed, and the portion surrounded by the narrow groove is made into an insulating pattern layer, and then an insulating material is applied to the narrow groove It is good also as a manufacturing method of the conductive nanofiber sheet characterized by doing.

  The present invention is also a method for producing a conductive nanofiber sheet in which the method of applying an insulating material to the narrow groove is any one of die coating, inkjet, and dipping. Furthermore, this invention is good also as a touchscreen using the said electroconductive nanofiber sheet as an electrode.

  In the conductive nanofiber sheet of the present invention, the narrow groove is filled with an insulating material, and the depth of the narrow groove becomes shallow or disappears, and the shadow of the narrow groove becomes difficult to be reflected. Therefore, even if the thickness of the conductive pattern layer or the insulating pattern layer increases, the shadow of the narrow groove becomes difficult to be reflected, and the thickness of the conductive pattern layer or the insulating pattern layer is not affected by the thickness of the conductive pattern layer or the insulating pattern layer. The pattern appearance can be considerably reduced.

  In the conductive nanofiber sheet obtained by the present invention, the conductive pattern layer and the insulating pattern layer are formed of a photocurable material. By developing and removing a part of the pattern layer, a conductive nanofiber sheet having no visible pattern can be easily produced.

  In the method for producing a conductive nanofiber sheet of the present invention, a conductive pattern layer containing conductive nanofibers is formed on the entire surface of a substrate sheet, and exposed and developed, or an energy beam is irradiated to a part of the conductive pattern layer. Or etching to form a narrow groove and an island-like insulating pattern layer, and an insulating material is applied to the narrow groove by any one of a coating method of die coating, ink jetting, and dipping. Therefore, it is possible to easily manufacture a conductive nanofiber sheet in which the pattern appearance is considerably reduced.

(1) is a plan view showing a schematic configuration of the conductive nanofiber sheet according to the first embodiment of the present invention, and (2) is a sectional view taken along line II-II shown in (1). It is. (1) is a partially enlarged view of the conductive pattern layer and the insulating pattern layer shown in (2) of FIG. 1, and (2) is a touch panel using the conductive nanofiber sheet shown in FIG. 1 as an electrode. It is sectional drawing which showed schematic structure. It is the figure which showed the manufacturing process of the electroconductive nanofiber sheet | seat shown in FIG. It is the figure which showed the other manufacturing process of the electroconductive nanofiber sheet | seat shown in FIG. (1) is a plan view showing a schematic configuration of a conductive nanofiber sheet according to the second embodiment of the present invention, and (2) is a sectional view taken along line II-II shown in (1). It is.

  Next, embodiments of the invention will be described with reference to the drawings.

  With reference to FIG. 1 and FIG. 2 (1), a conductive nanofiber sheet 1 according to the first embodiment of the present invention is formed on a base sheet 10 and the base sheet 10. And a conductive pattern layer 6 having a plurality of minute pinholes 7 having a size that cannot be visually recognized through the conductive nanofiber 3 and the conductive pattern layer 6 on the base sheet 10. An insulating pattern layer 5 that is formed in an unformed portion, includes conductive nanofibers 3 and is insulated from the conductive pattern layer 6 is provided. The conductive pattern layer 6 and the insulating pattern layer 5 are each formed in a band shape in plan view, and are formed so as to be alternately arranged with one direction as an axial direction. In addition, the planar view shape of the conductive pattern layer 6 and the insulating pattern layer 5 may be formed in other shapes such as a shape in which a plurality of rhombus shapes are linearly continued in one direction. The insulating pattern layer 5 has a narrow groove 9 having a width that cannot be visually recognized. The conductive nanofibers 3 in which the narrow groove 9 is in a conductive state are disconnected, and the insulating pattern layer 5 is insulated from the conductive pattern layer 6 by the narrow groove 9. The narrow grooves 9 are formed in a lattice shape in plan view, and the insulating pattern layer 5 is formed in a plurality of island shapes having a rectangular shape in plan view. The minute pinhole 7 is formed over the entire surface of the conductive pattern layer 6. The narrow groove 9 and the minute pinhole 7 are filled with an insulating material. The insulating material is buried so that the narrow grooves 9 and the minute pinholes 7 are deep enough not to be shaded. The insulating material may be aligned over the upper surfaces of the conductive pattern layer 6 and the insulating pattern layer 5 to fill the entire depth of the narrow groove 9 and the minute pinhole 7. By putting the insulating material over the entire depth, there is no shadow caused by the presence of the depth, and the pattern appearance can be more effectively prevented.

  With reference to (2) of FIG. 2, the touch panel 8 using the conductive nanofiber sheet 1 as an electrode has two conductive nanofiber sheets 1 such that the axial directions of the conductive pattern layers 6 are orthogonal to each other. It is configured by pasting together. A protective plate 52 is bonded so as to cover the upper surface of the bonded conductive nanofiber sheet 1, and a liquid crystal display device is bonded to the lower surface.

  Examples of the material of the base sheet 10 include resin films such as acrylic, polycarbonate, polyester, polybutylene terephthalate, polypropylene, polyamide, polyurethane, polyvinyl chloride, and polyvinyl fluoride. The thickness of the base sheet layer can be appropriately set within a range of 5 to 800 μm. If the thickness is less than 5 μm, the strength of the layer is insufficient and the layer is torn when it is peeled off, making it difficult to handle. If the thickness exceeds 800 μm, the base sheet 10 layer is too rigid and difficult to process.

  Examples of the conductive pattern layer 6 and the insulating pattern layer 5 include those composed of a photocurable resin binder such as urethane acrylate and cyanoacrylate and the conductive nanofiber 3. The conductive pattern layer 6 and the insulating pattern layer 5 can be provided by various general printing methods such as gravure printing, offset printing, screen printing, and the like, and a dry film made of a photocurable resin containing the conductive nanofiber 3 It is also possible to provide a sheet such as a sticker.

  The conductive pattern layer 6 and the insulating pattern layer 5 are made of various resin binders 33 such as acrylic, polyester, polyurethane, and polyvinyl chloride, and conductive nanofibers, and can be used for gravure printing, offset printing, screen printing, and the like. You may provide by various general-purpose printing methods. The insulating pattern layer 5 is not different from the material of the conductive pattern layer 6 such as the binder resin 33 and the conductive nanofiber 3 except that the narrow groove 9 having a width that cannot be visually recognized is formed.

  The thicknesses of the conductive pattern layer 6 and the insulating pattern layer 5 are as equal as possible and are preferably in the range of 1 to 50 μm. If the thickness is less than 1 μm, the conductivity of the conductive pattern layer 6 may be insufficient. If the thickness exceeds 50 μm, it becomes difficult to embed part or all of the narrow grooves of the insulating pattern layer 5 with the insulating material 4. And in order to perform the process of embedding with the insulating material 4 more rapidly, it is more preferable to make thickness into 5 micrometers or less. The conductive pattern layer 6 and the insulating pattern layer 5 may be provided with a release layer, an anchor layer, or the like between the base sheet 10, and the conductive pattern 6 and the insulating pattern layer 5 may be anchored or bonded on the layer. A layer or the like may be provided.

  As an example of the conductive nanofiber 3, it was produced by continuously applying an applied voltage or current from the tip of the probe to the surface of a precursor carrying metal ions such as gold, silver, platinum, copper, and palladium. Examples thereof include metal nanowires, peptide nanofibers obtained by adding gold particles to nanofibers formed by self-organization of peptides or derivatives thereof. Further, even if the conductive nanofibers 3 are blackish, such as carbon nanotubes, if there is a difference in the color of the shadow or the reflectivity, it becomes a target.

  The width of the narrow groove 9 is preferably about 10 μm to 100 μm. This is because if the narrow groove 9 is formed with the width of the narrow groove 9 being less than 10 μm, the yield is extremely lowered, and it is technically difficult to fill the narrow groove 9. Further, if the width exceeds 100 μm, even if the narrow groove 9 is filled, the portion may be visually recognized when illuminated by illumination. Further, the depth of the narrow groove 9 corresponds to the thickness of the conductive pattern layer 6 and the insulating pattern layer 5.

  The shape of the narrow groove 9 may be a lattice shape, a honeycomb shape, a random shape, or any other shape, or may be a mixture of grooves having different shapes. Further, the island pattern of the insulating pattern layer 5 formed by being surrounded by the narrow groove 9 may be any of a polygonal shape, an elliptical shape, and an arc shape in addition to a circular shape, and these different shapes are mixed. It doesn't matter. The size of the island pattern is on the order of several hundred microns to several tens of millimeters, and the shapes of these different sizes may be mixed.

  As a method of forming the narrow groove 9 to obtain the insulating pattern layer 5, when the conductive pattern layer 6 is made of a photocurable resin, it is cured by exposure to light such as ultraviolet light, infrared light, or visible light, There is a method of developing and removing a part of the uncured conductive pattern layer 6.

  When the conductive pattern layer 6 is made of a material other than the photocurable resin, the narrow groove 9 is formed by forming the conductive pattern layer 6 including the conductive nanofibers 3 on the entire surface of the base sheet 10 and then forming the conductive pattern layer 6. For example, a method may be used in which a part of the substrate is irradiated with an energy beam such as a carbon dioxide laser having a spot diameter of several tens of μm to burn out the binder resin 33 of the conductive pattern layer 6. Alternatively, after forming an etching resist layer such as an alkyd resin, a polyester resin, or an epoxy resin on a part of the conductive pattern layer 6, the entire surface is etched with an acid or alkaline aqueous solution, and the conductive pattern layer in which no etching resist layer is formed. There is a method of removing a part of 6 by etching.

  Examples of the method for applying the insulating material 4 to the narrow groove 9 include die coating, ink jetting, and dipping, but other methods may be used.

  As the insulating material 4, for example, the same kind of material as that of the conductive pattern layer 6 and the insulating pattern layer 5 is used. If the same kind of material is used, the difference in refractive index, transmittance and haze value between the portion where the conductive pattern layer 6 and the insulating pattern layer 5 are formed and the portion where the insulating material 4 is buried is reduced. Therefore, in addition to reducing the pattern appearance by filling the narrow groove 9 with an insulating material, the pattern appearance can be further reduced. The insulating material 4 may be made of different materials in consideration of the above-described differences in refractive index, transmittance, and haze value. If the insulating material 4 contains insulating particles such as silica or an insulating wire material and is adjusted so that the above-described differences in refractive index, transmittance and haze value become smaller, the narrow groove 9 In addition to reducing the pattern appearance by embedding an insulating material, the pattern appearance can be further reduced. The insulating material 4 is preferably a liquid having a low viscosity. If the insulating material 4 is a liquid having a low viscosity, it is rich in fluidity, so that problems such as clogging are less likely to occur and foaming is reduced, so that the insulating material 4 can be quickly filled into the narrow groove 9. .

  It is preferable that the depth of the narrow groove 9 after applying the insulating material is 0 to 1 μm. If the depth exceeds 1 μm, a shadow may appear in the narrow groove 9.

  In addition, it is preferable to form the position detection mark 25 of a size of about 3 to 10 mm square, for example, on the base sheet 10. This is because if the position detection mark 25 is read by an optical method, the narrow groove 9 can be formed at a predetermined position on the base sheet 10, and when the insulating material 4 is applied by inkjet or the like, it can be applied with high positional accuracy. As described above, in the present invention, only the filling of the narrow groove 9 has been described, but the case where the minute pinhole 7 having a size that cannot be visually recognized is formed in the conductive pattern layer 9 is described in the same manner as the filling of the narrow groove 9. Can solve the problem.

  In the conductive nanofiber sheet 1 obtained by the above method, the pattern appearance of the conductive pattern layer 6 and the insulating pattern layer 5 is considerably reduced. It is possible to manufacture a resistance film type or electrostatic capacity type touch panel that is excellent in resistance.

  Next, the conductive nanofiber sheet 2 according to the second embodiment of the present invention will be described. Since the basic configuration is common to the conductive nanofiber sheet 1 according to the first embodiment, different points will be described.

  Referring to FIG. 5, in the first embodiment, the insulating pattern layer 5 made of a plurality of islands surrounded by the narrow grooves 9 is formed. In the second embodiment, such an insulating pattern layer 5 is formed. The pattern layer is not formed. In the first embodiment, a plurality of minute pinholes 7 are formed in the conductive pattern layer 6. However, in the second embodiment, such minute pinholes 7 are not formed. The conductive nanofiber sheet 2 includes a base sheet 10 and a conductive pattern layer 6 that is formed on the base sheet 10, includes the conductive nanofiber 3, and can be conducted through the conductive nanofiber 3. Yes. The conductive pattern layer 6 is divided into a plurality of regions by narrow grooves 9 having a width that cannot be visually recognized, and the adjacent conductive pattern layers 6 are insulated by the narrow grooves 9. Each of the plurality of divided regions is formed in a planar view band shape, and is arranged with one direction as an axial direction. In addition, the planar view shape of the electroconductive pattern layer 6 is formed in the shape according to the use of the touch panel to which the electroconductive nanofiber sheet 2 is applied, a function, performance, etc. The narrow groove 9 is filled with an insulating material 4 as in the case of the conductive nanofiber sheet 1.

  In the conductive nanofiber sheet 2, since the insulating material 4 is buried in the narrow groove 9, the shadow of the narrow groove 9 portion disappears, and the pattern appearance generated from the narrow groove 9 can be considerably reduced. Since the insulating pattern layer 5 as shown in the conductive nanofiber sheet 1 is not configured, the total area of the conductive nanofiber sheet 2 can be reduced, which is effective when applied to a touch panel with a small area. .

  A conductive nanofiber 2 made of silver nanowires having an average diameter of 0.2 μm and an average length of 10 μm on one side of a biaxially stretched polyethylene terephthalate film having a thickness of 100 μm as the base sheet 10 is a binder made of a cyanoacrylate UV curable resin. Silk printing was performed using the ink dispersed in the resin 33, and touch drying with hot air was performed to form a conductive pattern layer 6 having a thickness of 3 μm. Next, a photomask 20 having a large number of narrow groove positive patterns is placed thereon, a part of the conductive pattern layer 6 is exposed by irradiating with ultraviolet rays, and an uncured narrow groove pattern portion is peeled off with an organic solvent. The insulating pattern layer 5 was formed by removing (see FIG. 3). Next, the narrow groove 9 of the insulating pattern layer 5 was filled with an insulating material 4 made of urethane acrylate-based ultraviolet curable resin by a die coating method, thereby forming the conductive nanofiber sheet 1 in which the narrow groove 9 was completely filled ( (See (1) in FIGS. 1 and 2).

  The narrow grooves 9 formed in the insulating pattern layer 5 occupy about 37% of the total area of the insulating pattern layer 5 and have a lattice shape with a pitch of 300 μm and an average width of about 50 μm. Normally, the width cannot be determined from the appearance, but before filling the narrow groove 9, when illuminated from an oblique angle, the narrow groove 9 becomes shadowed and black, and contrast with the white color of the silver nanowires. As a result, some people have the problem of recognizing their existence. However, in the conductive nanofiber sheet 1 in which the narrow groove 9 is filled with the insulating material 4, no one can recognize its existence, the optical performance is as good as 92% light transmittance, 3% haze value, and surface resistance. The value was also in the range of good conductivity of 50 to 200Ω / □.

  The obtained conductive nanofiber sheet 1 is a sheet made of a transparent conductive pattern layer 6, which has no visible pattern of the conductive pattern layer 6, has high light transmittance, and can be bent. Then, the two conductive nanofiber sheets 1 are bonded so that the axial directions of the conductive patterns 6 are orthogonal to each other to form an X electrode and a Y electrode, and a protective plate 52 is bonded so as to cover the upper surface thereof, If the liquid crystal display device 53 was attached to the lower surface, the transparent capacitive touch panel 8 could be manufactured (see (2) in FIG. 2).

  In the production of the conductive nanofiber sheet 1, a position detection mark 25 is formed on the base sheet 10, and a urethane acrylate UV curable resin containing the same conductive nanofiber 2 as in Example 1 instead of the binder resin 33. An insulating pattern layer 5 was formed in the same manner as in Example 1 except that a dry film 15 having a thickness of 5 μm was pasted on the base sheet 10 and developed (see FIG. 3). Next, the narrow groove 9 of the insulating pattern layer 5 is filled with the insulating material 4 made of urethane acrylate-based ultraviolet curable resin by reading the position detection mark 25 by the ink jet method with high positional accuracy, and 80% of the narrow groove 9 is filled. A conductive nanofiber sheet 1 was formed.

  In the conductive nanofiber sheet 1 obtained by this method, no one can recognize the presence of the narrow groove 9, optical performance, light transmittance is 90%, haze value is 2%, and surface resistance is also good. It was 30-100Ω / □ and a good conductivity range.

  In the production of the conductive nanofiber sheet 1, the binder resin 33 is changed to an acrylic resin instead of the ultraviolet curable resin, the thickness is set to 1 μm, and a carbon dioxide gas laser having a spot diameter of 20 μm is irradiated to form the binder resin 33 of the conductive pattern layer 6. A conductive nanofiber sheet 1 was formed in the same manner as in Example 1 except that the insulating pattern layer 5 was formed by burning (see (1) in FIG. 4). In the conductive nanofiber sheet 1 obtained by this method, no one can recognize the existence of the narrow groove 9, and the optical performance and the electrical performance are in a good range that does not cause a problem for the use of the touch panel.

  In forming the conductive nanofiber sheet 1, an etching resist layer made of an alkyd resin is formed on a part of the conductive pattern layer 6 instead of the method of burning out the binder resin 33, and then the entire surface is etched with an alkaline aqueous solution. A conductive nanofiber sheet 1 was formed in the same manner as in Example 3 except that the insulating pattern layer 5 was formed by etching away a part of the conductive pattern layer 6 where no film was formed ((2) in FIG. 4). And (3)). In the conductive nanofiber sheet 1 obtained by this method, no one can recognize the existence of the narrow groove 9, and the optical performance and the electrical performance are in a good range that does not cause a problem for the use of the touch panel.

DESCRIPTION OF SYMBOLS 1, 2 Conductive nanofiber sheet 3 Conductive nanofiber 4 Insulating material 5 Insulating pattern layer 6 Conductive pattern layer 7 Minute pinhole 8 Touch panel 9 Narrow groove 10 Base sheet 11 Etch resist layer 20 Photomask 25 Position detection mark 33 Resin binder 50 Laser irradiation machine tip 51 Laser irradiation light 52 Protection plate 53 Liquid crystal display device

Claims (12)

A base sheet;
A conductive pattern layer formed on the substrate sheet, including conductive nanofibers, and capable of conducting through the conductive nanofibers;
The conductive pattern layer is divided into a plurality of regions by narrow grooves having a width that cannot be visually recognized, and is set so that the conductive pattern layers adjacent to each other are insulated by the narrow grooves,
A conductive nanofiber sheet in which the narrow groove is filled with an insulating material over part or all of its depth. A base sheet;
A conductive pattern layer formed on the substrate sheet, including conductive nanofibers, and being conductive through the conductive nanofibers;
Formed on a portion of the base sheet where the conductive pattern layer is not formed, including the conductive nanofibers, and an insulating pattern layer insulated from the conductive pattern layer,
The insulating pattern layer has a narrow groove having a width that cannot be visually recognized, and is insulated from the conductive pattern layer by the narrow groove and formed into a plurality of islands,
A conductive nanofiber sheet in which the narrow groove is filled with an insulating material over part or all of its depth.   The conductive nanofiber sheet according to claim 1 or 2, wherein a depth of the narrow groove after the insulating material is buried is 0 to 1 µm.   The conductive nanofiber sheet according to any one of claims 1 to 3, wherein the conductive pattern layer has a thickness of 1 to 5 µm.   The conductive nanofiber sheet according to claim 2 or 3, wherein the insulating pattern layer has a thickness of 1 to 5 µm.   The conductive nanofiber sheet according to any one of claims 1 to 3, wherein the conductive pattern layer is formed of a photocurable material.   The conductive nanofiber sheet according to claim 2 or 3, wherein the insulating pattern layer is formed of a photocurable material. On the base sheet, a forming step of forming a conductive pattern layer made of a photocurable material including conductive nanofibers so as to be conductive on the entire surface,
Curing a part of the formed conductive pattern layer by photosensitivity;
By developing and removing the uncured portion of the partially cured conductive pattern layer, an insulating pattern layer insulated from the conductive pattern layer is formed and the insulating pattern layer is formed into an island shape by visual inspection. Forming a narrow groove having a width that cannot be recognized;
And a step of applying an insulating material to the formed narrow groove. On the base sheet, a forming step of forming a conductive pattern layer including conductive nanofibers on the entire surface so as to be conductive,
An insulating pattern layer insulated from the conductive pattern layer is formed by irradiating a part of the formed conductive pattern layer with energy rays to remove a part of the conductive pattern layer. Forming a narrow groove having a width that cannot be visually recognized,
And a step of applying an insulating material to the formed narrow groove. Forming a conductive pattern layer including conductive nanofibers on the entire surface of the base sheet so as to be conductive;
Forming an etching resist layer on a part of the formed conductive pattern layer;
An insulating pattern layer insulated from the conductive pattern layer by etching the entire surface of the conductive pattern layer on which the etching resist layer is formed, and removing the conductive pattern layer in a portion where the etching resist layer is not formed. Forming the insulating pattern layer into an island shape and forming a narrow groove having a width that cannot be visually recognized;
And a step of applying an insulating material to the formed narrow groove.   The method for producing a conductive nanofiber sheet according to any one of claims 8 to 10, wherein a method of applying the insulating material to the narrow groove is one of die coating, ink jetting, and dipping.   A touch panel using the conductive nanofiber sheet according to any one of claims 1 to 7 as an electrode.

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