JP2014092581A - Transparent conductive film with anti-reflective properties, touch panel, and image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transparent conductive film which has anti-reflective properties and yet offers superior adhesion of a transparent conductive layer.SOLUTION: A transparent conductive film having anti-reflective properties comprises; a micro concavo-convex structure containing a resin and having a micro concavo-convex pattern; a fist transparent conductive layer containing either a combination of an organic compound and conductive-metal-containing nano-particles or a conductive organic polymer; and a second transparent conductive layer containing a conductive metallic oxide formed on at least one surface of a transparent base material in the described order. A surface of an outer most layer on the second transparent conductive layer side has a micro concavo-convex pattern with a micro-protrusion group comprising a group of micro-protrusions. The micro-protrusions are structured such that the shortest wavelength Λmin in a wavelength band of anti-reflection target light and a maximum value dmax of distance d between two adjacent micro-protrusions satisfy a relationship expressed as dmax≤Λmin, and that a cross-sectional area occupied by the material portion of each micro-protrusion in a horizontal cross-sectional plane perpendicular to a depth direction thereof continuously and gradually increases from an apex thereof toward the deepest point.

Description

  The present invention relates to an antireflection transparent conductive film, a touch panel using the same, and an image display device.

  In recent years, a resistive touch panel for inputting information or a capacitive touch panel capable of simultaneous input of multiple points is disposed on a display device such as a liquid crystal display element included in a mobile device or a mobile phone device. It has become so.

  The resistive touch panel has a structure in which two transparent conductive films are arranged to face each other with a spacer made of an insulating material such as acrylic resin. A transparent conductive film functions as an electrode for a touch panel. A transparent base material such as a polymer film and a material having a high refractive index such as ITO (Indium Tin Oxide) formed on the base material. And a transparent conductive film (for example, about 1.9 to 2.1). In the case of a capacitive touch panel, the transparent conductive film for detecting XY coordinates is not limited to the above-described configuration, and the XY coordinates are detected through the front and back surfaces or the insulating layer. In order to ensure the operation of the transparent conductive film, the antireflection transparent conductive layer for removing electromagnetic noise generated from the liquid crystal display element is provided between the transparent conductive film and the liquid crystal display element. It is also effective to provide it.

  A transparent conductive film for a touch panel is required to have a surface resistance value of, for example, 500Ω / □ or less. The antireflection transparent conductive layer also requires a certain surface resistance value (for example, 10 ^ 6Ω / □ or less). In addition, the transparent conductive film is required to have a high transmittance in order to avoid deterioration in display quality of a display device such as a liquid crystal display element on which a resistive touch panel is disposed.

  In order to realize a desired surface resistance value, it is necessary to increase the thickness of the transparent conductive film constituting the transparent conductive film. However, if the transparent conductive film, which is a high refractive index material, is thickened, the reflection of external light at the interface between the transparent conductive film and the substrate increases, and the transmittance of the transparent conductive film decreases. There is a problem that the quality deteriorates.

  In order to solve this problem, for example, Patent Document 1 proposes a transparent conductive film for a touch panel in which an antireflection film is provided between a base material and a transparent conductive film. This antireflection film is formed by sequentially laminating a plurality of dielectric films having different refractive indexes.

Patent Document 2 includes a structure composed of convex portions or concave portions arranged on the surface of a substrate at a fine pitch equal to or smaller than the wavelength of visible light, and a transparent conductive film formed on the structure. The structure has a cone shape with an aspect ratio of 0.2 or more and 1.78 or less, the transparent conductive film has a surface that follows the structure, and an average film of the transparent conductive film at the top of the structure A transparent conductive electrode having a thickness D _m 1 of 5 nm or more and 80 nm or less and a surface resistance of the transparent conductive film of 270Ω / □ or more and 4000Ω / □ or less is described.
However, as in the technique disclosed in Patent Document 2, a structure having a plurality of convex portions or concave portions arranged at a fine pitch equal to or smaller than the wavelength of visible light has a surface following the structure. When a thin transparent conductive film is formed by vapor deposition, there is a problem that the adhesion of the transparent conductive film is poor. Moreover, in the said transparent conductive film, there existed a problem that the electrical conductivity of a transparent conductive film became inadequate.

JP 2003-136625 A Japanese Patent No. 4626721

  The present invention has been made in view of the above problems, and provides a transparent conductive film excellent in adhesion of a transparent conductive layer while having antireflection performance, and a touch panel and an image display device using the transparent conductive film. With the goal.

The antireflection transparent conductive film according to the present invention is a combination of a fine concavo-convex structure having a fine concavo-convex shape containing a resin on at least one surface of a transparent substrate, and an organic compound and conductive metal-containing nanoparticles. Or a first transparent conductive layer containing a conductive organic polymer and a second transparent conductive layer containing a conductive metal oxide in this order,
The outermost layer surface on the second transparent conductive layer side has fine irregularities provided with a group of minute protrusions formed by a collection of minute protrusions, and the minute protrusions have the shortest wavelength in the wavelength band of light for antireflection. , When the maximum value of the distance d between adjacent protrusions is dmax,
dmax ≦ Λmin
And the cross-sectional area occupancy rate of the material portion forming the microprojection in the horizontal cross section when it is assumed that the microprojection is cut in a horizontal plane perpendicular to the depth direction of the microprojection is It has the structure which increases gradually gradually as it approaches the deepest part direction from the top.

  The touch panel according to the present invention is a touch panel in which the electrode surfaces of two electrode films are opposed to each other at a constant interval, and at least one of the electrode films is the antireflection transparent conductive film according to the present invention. It is characterized by that.

  The image display apparatus according to the present invention is characterized in that the touch panel according to the present invention is provided on an image display surface.

  In the antireflection transparent conductive film, the touch panel, and the image display device according to the present invention, at least a part of the microprojections on the outermost layer surface on the second transparent conductive layer side are microprojections having a plurality of vertices. Is preferable from the viewpoint of improving the adhesion and antireflection performance of the transparent conductive layer.

  ADVANTAGE OF THE INVENTION According to this invention, it can provide the transparent conductive film excellent in the adhesiveness of a transparent conductive layer, and a touch panel and image display apparatus using the same, while having antireflection performance.

It is sectional drawing which shows typically an example of the antireflection transparent conductive film which concerns on this invention. It is sectional drawing which shows typically another example of the antireflection transparent conductive film which concerns on this invention. It is sectional drawing which shows typically another example of the antireflection transparent conductive film which concerns on this invention. It is a figure explaining the definition of the film thickness of the transparent conductive layer which concerns on this invention. It is sectional drawing (FIG.5 (a)), a perspective view (FIG.5 (b)), and a top view (FIG.5 (c)) with which it uses for description of the multimodal microprotrusion which has two or more vertices. It is a figure which shows a Delaunay figure. It is a frequency distribution diagram used for measurement of the distance between adjacent protrusions. It is a frequency distribution diagram used for description of the microprojection height. It is sectional drawing which shows typically the form in which the envelope surface of the valley bottom of a microprotrusion exhibits a large uneven | corrugated surface (undulation). It is the schematic which shows an example of the process of forming a fine grooving | roughness structure in a transparent base material among the manufacturing processes of the antireflection transparent conductive film of this invention. It is sectional drawing which shows typically an example of the touchscreen which concerns on this invention. It is sectional drawing which shows typically an example of the image display apparatus which concerns on this invention.

Next, embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments, and various modifications can be made within the scope of the spirit thereof.
The antireflection transparent conductive film of the present invention is defined as “film” including the meaning of both thick and thin films. In other words, it is usually “sheet-like” that is not supplied in the form of a roll, or is thicker than a sheet-like one, does not bend completely, and does not bend enough to be wound, but by applying a load A curved “plate” is also included in the “film” of the present invention.
In the present invention, (meth) acrylic resin means acrylic resin and / or methacrylic resin, and (meth) acrylate means acrylate and / or methacrylate.
Moreover, in this invention, resin is the concept containing a polymer other than a monomer and an oligomer.

I. Antireflective transparent conductive film The antireflective transparent conductive film according to the present invention includes a fine concavo-convex structure having a fine concavo-convex shape containing a resin on at least one surface of a transparent substrate, an organic compound, and a conductive property. A first transparent conductive layer containing a combination of metal-containing nanoparticles or a conductive organic polymer, and a second transparent conductive layer containing a conductive metal oxide in this order,
The outermost layer surface on the second transparent conductive layer side has fine irregularities provided with a group of minute protrusions formed by a collection of minute protrusions, and the minute protrusions have the shortest wavelength in the wavelength band of light for antireflection. , When the maximum value of the distance d between adjacent protrusions is dmax,
dmax ≦ Λmin
And the cross-sectional area occupancy rate of the material portion forming the microprojection in the horizontal cross section when it is assumed that the microprojection is cut in a horizontal plane perpendicular to the depth direction of the microprojection is It has the structure which increases gradually gradually as it approaches the deepest part direction from the top.

In the antireflection transparent conductive film of the present invention, since the outermost layer surface on the second transparent conductive layer side has fine irregularities having the specific structure, at least the transparent conductive layer and the outside (usually an air layer) It is an antireflection transparent conductive film that realizes an antireflection effect at the interface and an improvement in the transmittance of the transparent conductive film.
The specific fine unevenness is obtained by including a fine uneven structure containing a resin and having a fine uneven shape. Therefore, the fine uneven shape of the fine uneven structure needs to be maintained. The antireflective transparent conductive film of the present invention comprises a combination of an organic compound and conductive metal-containing nanoparticles or a conductive organic material between a fine concavo-convex structure and a second transparent conductive layer containing a conductive metal oxide. A first transparent conductive layer containing a polymer is interposed. Since the first transparent conductive layer contains an organic compound or a conductive organic polymer, the adhesion between the fine concavo-convex structure containing resin and the first transparent conductive layer, and further through the first transparent conductive layer. Thus, the adhesion with the second transparent conductive layer is improved. Moreover, since such a 1st transparent conductive layer is normally formed by the apply | coating method, the film formability of the 2nd conductive layer normally formed by a vapor deposition method is maintained, maintaining the fine uneven | corrugated shape of the said fine uneven structure. As a result, the shape of the fine irregularities on the surface of the outermost layer on the second transparent conductive layer side is also maintained, so that the antireflection performance is excellent.
In addition, a first transparent conductive layer containing a combination of an organic compound and conductive metal-containing nanoparticles or a conductive organic polymer, and a second transparent conductive layer containing a conductive metal oxide are included in this order. Since the conductive layer has a two-layer structure, the thickness of the transparent conductive layer can be sufficiently ensured and the conductivity is excellent.

FIG. 1 is a cross-sectional view schematically showing an example of an antireflection transparent conductive film according to the present invention. An antireflective transparent conductive film 10 shown in FIG. 1 includes a fine concavo-convex structure 2 having a fine concavo-convex shape, containing resin on one surface of the transparent base 1 in order from the transparent base 1 side, A first transparent conductive layer 3 containing a combination of an organic compound and conductive metal-containing nanoparticles or a conductive organic polymer, and a second transparent conductive layer 4 containing a conductive metal oxide, and a second transparent The outermost layer surface on the conductive layer 4 side has the specific fine irregularities.
An antireflective transparent conductive film 10 shown in FIG. 2 has a fine concavo-convex structure 2 containing a resin and having a fine concavo-convex shape on one surface of a transparent substrate 1. It has the 1st transparent conductive layer 3 and the 2nd transparent conductive layer 4 in this order on the surface, and the outermost layer surface by the side of the 2nd transparent conductive layer 4 becomes the said specific fine unevenness | corrugation.
Hereinafter, the transparent substrate, the fine concavo-convex structure, the first transparent conductive layer, and the second transparent conductive layer included in the antireflection transparent conductive film according to the present invention will be described in order.

<Transparent substrate>
As said transparent base material, the well-known transparent base material used for a transparent conductive film can be selected suitably, and is not specifically limited. Examples of the material used for the transparent substrate include a transparent resin. Examples of the transparent resin include acetyl cellulose resins such as triacetyl cellulose, polyester resins such as polyethylene terephthalate and polyethylene naphthalate, olefin resins such as polyethylene and polymethylpentene, acrylic resins, polyurethane resins, and polyethers. Examples include sulfone, polycarbonate, polysulfone, polyether, polyether ketone, acrylonitrile, methacrylonitrile, cycloolefin polymer, and cycloolefin copolymer.
In addition to the transparent resin, materials used for the transparent substrate include, for example, soda glass, potassium glass, lead glass, and other transparent inorganic materials such as ceramics such as PLZT, quartz, and fluorite. Can be mentioned.

  The transparent substrate preferably has a transmittance in the visible light region of 80% or more, and more preferably 90% or more. Here, the transmittance | permeability of a transparent base material can be measured by JISK7361-1 (the test method of the total light transmittance of a plastic-transparent material).

  Although the thickness of the said transparent base material can be suitably set according to the use of the transparent conductive film of this invention, Although it does not specifically limit, Usually, it is 20-5000 micrometers, The said transparent base material is supplied with the form of a roll. However, it may be any one of those that do not bend to the extent that they can be wound, but that can be bent by applying a load, or those that do not bend completely.

The configuration of the transparent substrate used in the present invention is not limited to a configuration consisting of a single layer, and may have a configuration in which a plurality of layers are laminated. When it has the structure by which the several layer was laminated | stacked, the layer of the same composition may be laminated | stacked, and the several layer which has a different composition may be laminated | stacked.
Moreover, you may form the primer layer for improving the adhesiveness of a transparent base material and the fine grooving | roughness structure mentioned later, and by extension, abrasion resistance on a transparent base material. This primer layer only needs to have adhesiveness to both the transparent substrate and the fine concavo-convex structure and be transparent in terms of visible optics.
As a material for the primer layer, for example, a material selected from a fluorine-based coating agent and a silane coupling agent can be used as appropriate. Examples of commercially available fluorine coating agents include Fluorosurf FG-5010Z130 manufactured by Fluoro Technology, and examples of commercially available silane coupling agents include Durasurf Primer DS-PC-3B manufactured by Harves. Etc.

  Further, as shown in FIG. 2 described above, the fine concavo-convex structure to be described later is formed on the surface of the transparent resin base material by shaping one surface of the transparent base material. The transparent resin base material and the fine concavo-convex structure may have a single layer structure.

<Fine uneven structure>
At least one surface of the transparent substrate has a fine concavo-convex structure containing a resin and having a fine concavo-convex shape.
The fine concavo-convex structure may be laminated as a separate layer made of a material different from the transparent base material as shown in FIG. 1, or transparent as a transparent base material as shown in FIG. A resin base material may be used and formed integrally with the transparent resin base material.
Moreover, from the point which improves base-material surface performances, such as adhesiveness between layers, coating suitability, and surface smoothness, a fine concavo-convex structure body via at least one intermediate layer on at least one surface of the transparent base material It may be a laminated body in which are stacked.
Moreover, you may have the said fine concavo-convex structure on both surfaces of a transparent base material directly or through another layer.

When laminating the fine concavo-convex structure as a layer different from the transparent substrate, the fine concavo-convex structure is preferably made of a resin, and further made of a cured product of the resin composition. The resin composition used for forming the microprojection structure includes at least a resin and, if necessary, other components such as a polymerization initiator.
The resin is not particularly limited, for example, ionizing radiation curable resins such as acrylate, epoxy, and polyester, acrylate, urethane, epoxy, polysiloxane, and other thermosetting resins, acrylate, Various materials such as polyester resins, polycarbonate resins, polyethylene resins, polypropylene resins, and the like, and various types of curing resins can be used. The ionizing radiation means electromagnetic waves or charged particles having energy that can be cured by polymerizing molecules. For example, all ultraviolet rays (UV-A, UV-B, UV-C), visible rays, gamma rays , X-rays, electron beams and the like.

As the resin, an ionizing radiation curable resin is preferable from the viewpoint of excellent formability and mechanical strength of a fine uneven shape.
The ionizing radiation curable resin used in the present invention is a mixture of a monomer having a radical polymerizable and / or cationic polymerizable bond in the molecule, a polymer having a low polymerization degree, and a reactive polymer. It is cured by a polymerization initiator described later. In addition, you may contain a non-reactive polymer.

  The resin composition further contains a release agent, a photosensitizer, an antioxidant, a polymerization inhibitor, a crosslinking agent, an infrared absorber, an antistatic agent, a viscosity modifier, an adhesion improver, etc., as necessary. It can also be contained.

The fine concavo-convex shape of the fine concavo-convex structure is formed by forming at least first and second transparent conductive layers, which will be described later, on the surface of the fine concavo-convex structure having the fine concavo-convex shape, and forming the outermost layer on the second transparent conductive layer side. The surface is not particularly limited as long as it can have specific fine irregularities described later.
Since it becomes an underlayer of specific fine unevenness described later, it is preferable that the fine unevenness of the fine unevenness included in the fine unevenness structure has a structure similar to the minute protrusion of the specific fine unevenness described later.
For example, it is preferable that the adjacent convex part interval of the fine convex part in the fine concavo-convex structure is usually designed to be 10 to 300 nm. Moreover, it is preferable to design the height of a micro convex part normally with 10-400 nm.

In particular, as shown in FIG. 3, it is preferable that the fine concavo-convex shape of the fine concavo-convex structure 2 has a flat portion 2 c at a valley bottom portion 2 b between adjacent convex portions 2 a and convex portions 2 a ′. Thereby, it becomes easy to make the outermost layer surface by the side of the 2nd transparent conductive layer of the antireflection transparent conductive film of this invention into the specific fine uneven | corrugated shape provided with the microprotrusion group mentioned later.
In addition, the said flat part is an adjacent convex in the said fine concavo-convex structure 2, when the intersection line of the envelope surface 2d which connected the valley bottom of the adjacent convex part, and convex part 2a etc. is made into a "hem" (2e). It means a portion that does not constitute a minute protrusion from the skirt 2e to the skirt 2e ′ between the portions. The size of the flat portion can be appropriately adjusted to a size that allows the outermost layer surface on the second transparent conductive layer side of the antireflection transparent conductive film of the present invention to have a fine uneven shape, which will be described later. The shortest distance (E in FIG. 2) from the skirt to the skirt between adjacent minute projections is preferably 50 to 300 nm, and particularly preferably 50 to 100 nm. In addition, the said distance observes the TEM photograph or SEM photograph of the vertical cross section which cut | disconnected the fine uneven | corrugated layer in the depth direction so that the antireflection transparent conductive film of this invention might contain the top part of an adjacent minute convex part. Can be measured.

As shown in FIG. 1, when the fine concavo-convex structure is laminated as a separate layer made of a material different from the transparent substrate, the thickness of the fine concavo-convex layer (t in FIG. 1) is particularly Although not limited, it is usually 10 to 300 μm. The thickness of the fine concavo-convex layer means the distance in the direction perpendicular to the substrate plane from the interface on the transparent substrate side of the fine concavo-convex layer to the height of the highest top of the fine concavo-convex surface of the fine concavo-convex layer. To do.
When the fine concavo-convex structure is integrated with the transparent substrate as shown in FIG. 2, the total thickness of the fine concavo-convex structure and the transparent substrate (t ′ in FIG. 2) is: Although not particularly limited, it is usually 20 to 5300 μm. The total thickness of the fine concavo-convex layer and the transparent substrate is a distance in a direction perpendicular to the substrate plane from the height of the highest top of the fine concavo-convex surface to the substrate plane opposite to the fine concavo-convex surface. Means.

<First transparent conductive layer>
In the antireflection transparent conductive film of the present invention, the first transparent conductive layer formed on the fine concavo-convex structure contains a combination of an organic compound and conductive metal-containing nanoparticles, or a conductive organic polymer. .
Since the first transparent conductive layer contains an organic compound or a conductive organic polymer, the affinity between the fine concavo-convex structure comprising the resin and the first transparent conductive layer is increased, and the adhesiveness is excellent. Become. Moreover, the 1st transparent conductive layer containing the combination of an organic compound and a conductive metal containing nanoparticle or a conductive organic polymer shall be formed on the fine concavo-convex structure formed by the solution coating method. Is possible. When formed on a fine concavo-convex structure containing the resin by a solution coating method, there is an advantage that the concavo-convex shape on the surface of the first transparent conductive layer can be easily formed into a desired shape.

  The conductive organic polymer is not particularly limited, and is polypyrrole, polyindole, polycarbazole, polythiophene (including basic polythiophene, the same applies hereinafter), polyaniline, polyacetylene, polyfuran, polyparaphenylene vinylene, polyazulene. It is also possible to use chain-type conductive polymers such as poly-type, polyparaphenylene-type, polyparaphenylene sulfide-type, polyisothianaphthene-type, and polythiazyl, and polyacene-type conductive polymers. Of these, polyethylene dioxythiophene (PEDOT) and polyaniline are preferable from the viewpoints of conductivity and transparency.

Moreover, in this invention, in order to raise the electroconductivity of the said conductive polymer more, it is preferable to perform a doping process. As a dopant for the conductive polymer, for example, a sulfonic acid having a hydrocarbon group having 6 to 30 carbon atoms (hereinafter also referred to as “long-chain sulfonic acid”) or a polymer thereof (for example, polystyrene sulfonic acid), halogen , Lewis acid, proton acid, transition metal halide, transition metal compound, alkali metal, alkaline earth metal, MClO ₄ (M = Li ⁺ , Na ⁺ ), R ₄ N ⁺ (R═CH ₃ , C ₄ H ₉ , C ₆ H ₅ ), or R ₄ P ⁺ (R═CH ₃ , C ₄ H ₉ , C ₆ H ₅ ). Especially, the said long chain sulfonic acid and its polymer are preferable, for example, PEDOT: PSS (polyethylene dioxythiophene poly (styrene sulfonate)) is used suitably.

Examples of the long chain sulfonic acid include dinonyl naphthalene disulfonic acid, dinonyl naphthalene sulfonic acid, and dodecylbenzene sulfonic acid. Examples of the halogen include Cl ₂ , Br ₂ , I ₂ , ICl ₃ , IBr, IF _{5 and the} like. Examples of the Lewis acid include PF ₅ , AsF ₅ , SbF ₅ , BF ₃ , BCl ₃ , BBr ₃ , SO ₃ , GaCl _{3 and the} like.
Examples of the protonic acid include HF, HCl, HNO ₃ , H ₂ SO ₄ , HBF ₄ , HClO ₄ , FSO ₃ H, ClSO ₃ H, CF ₃ SO ₃ H, and the like.
The transition metal _{halide, NbF 5, TaF 5, MoF} 5, WF 5, RuF 5, BiF 5, TiCl 4, ZrCl 4, MoCl 5, MoCl 3, WCl 5, FeCl 3, TeCl 4, SnCl 4, SeCl ₄ , FeBr ₃ , SnI _{5 and the} like. The transition metal _{compound, AgClO 4, AgBF 4, La} (NO 3) 3, Sm (NO 3) 3 and the like. Examples of the alkali metal include Li, Na, K, Rb, and Cs. Examples of the alkaline earth metal include Be, Mg, Ca, Sc, and Ba.
It is preferable that 0.001 mass part or more of the said dopant is contained with respect to 100 mass parts of conductive polymers. Furthermore, it is more preferable that 0.5 mass part or more is contained.

  On the other hand, in the combination of the organic compound and conductive metal-containing nanoparticles used in the first transparent conductive layer of the present invention, examples of the organic compound include those used as a protective agent or binder component present on the nanoparticle surface. . Examples of the protective agent include organic compounds having a functional group having a high affinity for nanoparticles and a portion having a high affinity for a dispersion solvent, and those that function as so-called surfactants, dispersants, and the like contain conductive metals. What is necessary is just to select suitably according to a nanoparticle. The organic compound used in the present invention may be a low molecular compound or a high molecular compound, and the conductive organic polymer may be used.

Moreover, as a conductive metal containing nanoparticle used for a 1st transparent conductive layer, what is necessary is just to contain a conductive metal, In addition to the case where a conductive metal is included, conductive metal compounds, such as a conductive metal oxide, are included. Nanoparticles may be included.
Examples of conductive metals include Group 6 transition metals, Group 7 transition metals, Group 8 transition metals, Group 9 transition metals, Group 10 (Group 8A) transition metals, Group 11 (Group 1B) transition metals, It is desirable to use a transition metal of Group 12 (2B), a typical metal of Group 13 (3B), a typical metal of Group 14 (4B), and more specifically, molybdenum (Mo), chromium (Cr), tungsten (W), nickel (Ni), palladium (Pd), platinum (Pt), zinc (Zn), copper (Cu), silver (Ag), gold (Au), aluminum (Al), gallium (Ga), indium Examples thereof include those selected from the group consisting of (In), tin (Sn), and combinations thereof. The conductive metal may be used alone or in combination of two or more metals, or an alloy of two or more metals may be used.
Examples of the conductive metal compound include a metal complex in which a ligand is coordinated to a metal, and a metal compound in which an organic or inorganic chemical group is covalently bonded and ionically bonded to a metal. As the conductive metal oxide, those described in detail in the second transparent conductive layer can be suitably used. Specific examples of other conductive metal compounds include copper (II) hydroxide (Cu (OH) ₂ ), copper (I) thiocyanate (CuSCN), and copper (II) nitrate (Cu (NO ₃ )). ₂ ), palladium nitrate (Pd (NO ₃ ) ₂ ), silver nitrate (AgNO ₃ ), silver nitrite (AgNO ₂ ), copper sulfate (II) (CuSO ₄ ), aluminum sulfate (Al ₂ (SO ₄ ) ₃ ), sulfuric acid Zinc (ZnSO ₄ ), gold cyanide (I) (AuCN), and the like can be given.

  The particle diameter of the conductive metal-containing nanoparticles is not particularly limited, but the average particle diameter is preferably 1 to 20 nm and particularly preferably 1 to 10 nm from the viewpoint of excellent transparency. In addition, in this invention, an average particle diameter is an arithmetic average particle diameter measured from a TEM photograph or a SEM photograph, for example, observation of particle | grains using the TEM photograph or SEM photograph image | photographed by 2 to 2 million times. The arithmetic average value of the particle diameters of 100 particles observed and observed can be used as the average particle diameter. Further, in the present invention, when the particle shape is a shape including the concept of aspect ratio, such as a spheroid shape or a rod shape having a minor axis and a major axis, the particle size of the particle is an average value of the minor axis and the major axis. And

  In the combination of the organic compound and the conductive metal-containing nanoparticles used in the first transparent conductive layer of the present invention, the organic compound is 0.01 to 50% by weight based on the total amount of the organic compound and the conductive metal-containing nanoparticles. About 0.1 to 30% by weight is more preferable.

  The first transparent conductive layer can be formed by inkjet printing, screen printing, gravure printing, offset printing, flexographic printing, dispenser printing, slit coating, die coating, doctor blade coating, wire bar coating. A solution coating method such as a method, a spin coating method, a dip coating method, or a spray coating method is preferably used.

FIG. 4 is a diagram illustrating the film thickness of the first transparent conductive layer of the present invention. In the 1st transparent conductive layer 3 in this invention, about the film thickness D1 of the transparent conductive layer in the top part 5 of the convex part of the said fine concavo-convex structure body, and the film thickness D3 of the transparent conductive layer in the trough part 6, it is between said microprotrusion. The distance from the microprojection structure-side interface 9 of the transparent conductive layer to the transparent conductive layer surface 11 in the normal direction 8 with respect to the envelope surface 7 connecting the valley bottoms.
On the other hand, regarding the film thickness D2 of the transparent conductive layer on the slope of the minute projection, such as a half (H / 2) portion of the height (H) of the minute projection, the normal direction of the slope of the minute projection The distance is 12.

Although the thickness of the said 1st transparent conductive layer is not specifically limited, The average film thickness D1-1 of the 1st transparent conductive layer in the top part 5 of the convex part of the said fine concavo-convex structure is in the range of 0-20 nm. Is preferable, and it is particularly preferably in the range of 0 to 10 nm. Moreover, it is preferable that the average film thickness D3-1 of the 1st transparent conductive layer in the trough part 6 of the said fine concavo-convex structure is in the range of 1 to 60 nm, and particularly in the range of 1 to 30 nm. . Moreover, it is preferable that the average film thickness D2-1 of the 1st transparent conductive layer in 1/2 of the height of a micro convex part exists in the range of 0.1-40 nm, and especially in the range of 0.1-20 nm. It is preferable that
If the thickness of the first transparent conductive layer is less than the lower limit, it may be difficult to form a continuous layer. If the thickness exceeds the upper limit, the antireflection performance may be deteriorated. 2 It may be difficult to make the surface of the outermost layer on the side of the transparent conductive layer have specific fine irregularities.

<Second transparent conductive layer>
The antireflection transparent conductive film of the present invention has a second transparent conductive layer containing a conductive metal oxide on the first transparent conductive layer.
Conductive metal oxide is easy to improve the conductivity when made with the same film thickness as the conductive organic polymer and conductive metal-containing nanoparticles, but trying to laminate a thin film directly on the fine concavo-convex structure Then, there existed a problem that adhesiveness was bad. In the present invention, the fine concavo-convex structure has a conductive metal oxide containing a combination of an organic compound and conductive metal-containing nanoparticles or a first transparent conductive layer containing a conductive organic polymer. Two transparent conductive layers are laminated. Therefore, while improving the adhesion between the fine concavo-convex structure, the first transparent conductive layer, and the second transparent conductive layer, the concavo-convex shape on the outermost layer surface on the second transparent conductive layer side is formed to have specific fine concavo-convex. There is a merit that it is easy. Moreover, since the transparent conductive layer has the above-mentioned two-layer structure, the film thickness of the transparent conductive layer can be sufficiently secured while the outermost surface is made to have specific fine irregularities, and the conductivity becomes excellent.

The conductive metal oxide is preferably a transparent oxide semiconductor, for example, a binary compound such as SnO ₂ , InO ₂ , ZnO and CdO, or a constituent element of the binary compound, Sn, In, Zn and Cd. Among these, a ternary compound containing at least one element or a multi-component (composite) oxide can be used. Examples of the material constituting the transparent conductive layer include ITO (In ₂ O ₃ , SnO ₂ : indium tin oxide), AZO (Al ₂ O ₃ , ZnO: aluminum-doped zinc oxide), SZO, and FTO (fluorine-doped tin oxide). ), SnO ₂ (tin oxide), GZO (gallium-doped zinc oxide), IZO (In ₂ O ₃ , ZnO: indium zinc oxide), etc., but high reliability, low resistivity, etc. From the viewpoint, ITO is preferable. These conductive metal oxides are preferably in a mixed state of amorphous and polycrystal from the viewpoint of improving conductivity.

  The particle size of the conductive metal oxide crystal particles is not particularly limited, but the average particle size is preferably 1 to 20 nm, and particularly preferably 1 to 10 nm, from the viewpoint of excellent transparency. In addition, in this invention, an average particle diameter is an arithmetic average particle diameter measured from a TEM photograph or a SEM photograph, for example, observation of particle | grains using the TEM photograph or SEM photograph image | photographed by 2 to 2 million times. The arithmetic average value of the particle diameters of 100 particles observed and observed can be used as the average particle diameter. Further, in the present invention, when the particle shape is a shape including the concept of aspect ratio, such as a spheroid shape or a rod shape having a minor axis and a major axis, the particle size of the particle is an average value of the minor axis and the major axis. And

  The method for forming the second transparent conductive layer is not particularly limited, and for example, a liquid phase method such as a sol-gel method, a liquid phase deposition method, a spray method, or a pyrosol method, a gas phase such as a sputtering method, a vacuum deposition method, or a CVD method. Law. Among these, the vapor phase method is preferable, and the sputtering method is particularly preferable because it is easy to form a continuous layer thin film.

The thickness of the second transparent conductive layer is also defined in the same manner as the thickness of the first transparent conductive layer. Although the thickness of a 2nd transparent conductive layer is not specifically limited, The average film thickness D1-2 of the 2nd transparent conductive layer in the top part 5 of the convex part of the said fine concavo-convex structure is in the range of 1-60 nm. It is particularly preferable that the thickness is in the range of 1 to 30 nm. Moreover, it is preferable that the average film thickness D3-2 of the 2nd transparent conductive layer in the trough part 6 of the said fine concavo-convex structure body exists in the range of 0-20 nm, and it is especially preferable that it exists in the range of 0-10 nm. . Moreover, it is preferable that the average film thickness D2-2 of the 2nd transparent conductive layer in 1/2 of the height of a micro convex part exists in the range of 0.1-40 nm, especially in the range of 0.1-20 nm. It is preferable that
If the thickness of the second transparent conductive layer is less than the lower limit, it may be difficult to improve the conductivity, and if it exceeds the upper limit, the antireflection performance may be deteriorated. 2 It may be difficult to make the surface of the outermost layer on the side of the transparent conductive layer have specific fine irregularities.

  The first transparent conductive layer is preferably a continuous layer, but may be a continuous layer including a portion where the layer is not formed in an island shape, such as a sea portion of a sea-island structure. On the other hand, the second transparent conductive layer may be a discontinuous layer such as an island portion of a sea-island structure as long as it has a contact portion with the first transparent conductive layer as a base. The laminated body of the first transparent conductive layer and the second transparent conductive layer is preferably formed so as to cover the entire surface of the fine concavo-convex structure in a stage before patterning described later.

  Further, the total thickness of the first transparent conductive layer and the second transparent conductive layer is not particularly limited, but the transparent conductive layer (the first transparent conductive layer and the second transparent conductive layer at the top 5 of the convex portion of the fine concavo-convex structure body). The average film thickness D1 of the total thickness of the transparent conductive layers is preferably in the range of 1 to 80 nm, and particularly preferably in the range of 1 to 40 nm. Moreover, the average film thickness D3 of the transparent conductive layer (the total thickness of the first transparent conductive layer and the second transparent conductive layer) in the valley 6 of the fine concavo-convex structure is in the range of 1 to 80 nm. It is particularly preferable that the thickness is in the range of 1 to 40 nm. Moreover, the average film thickness D2 of the transparent conductive layer (the total film thickness of the first transparent conductive layer and the second transparent conductive layer) at ½ of the height of the minute convex portion is within a range of 0.2 to 80 nm. It is preferable that it is within a range of 0.2 to 40 nm.

  The surface resistance of the transparent conductive layer (the first transparent conductive layer and the second transparent conductive layer) is not particularly limited as long as it is appropriately selected depending on the application, but is preferably in the range of 500Ω / □ or less. More preferably, it is in the range of 250Ω / □ or less. This is because by setting the surface resistance within such a range, a transparent conductive film can be used as an upper electrode or a lower electrode of various types of touch panels. Here, the surface resistance of the transparent conductive layer can be determined by 4-terminal measurement (JIS K 7194).

<Fine irregularities on the outermost layer surface>
In the present invention, the surface of the outermost layer on the second transparent conductive layer side has fine irregularities provided with a group of minute protrusions formed by a collection of minute protrusions, and the minute protrusions have a wavelength band of light for preventing reflection. Is the shortest wavelength Λmin, and the maximum value of the distance d between adjacent protrusions of the microprotrusions is dmax,
dmax ≦ Λmin
And the cross-sectional area occupancy rate of the material portion forming the microprojection in the horizontal cross section when it is assumed that the microprojection is cut in a horizontal plane perpendicular to the depth direction of the microprojection is It has the structure which increases gradually gradually as it approaches the deepest part direction from the top.
The “outermost layer surface on the second transparent conductive layer side” is a surface on which the transparent substrate on the side including the fine concavo-convex structure, the first transparent conductive layer, and the second transparent conductive layer is present. Means the surface of the outermost layer on the opposite side. When the second transparent conductive layer is the outermost layer, it is the surface of the second transparent conductive layer, and another layer is laminated on the second transparent conductive layer. In the case, it is the surface of the other layer.

The minute protrusions are closely arranged so that the distance d between adjacent protrusions (see FIG. 1) is not more than the shortest wavelength Λmin (d ≦ Λmin) of the wavelength band for preventing reflection. When the antireflection transparent conductive film according to the present invention is used mainly for the purpose of improving visibility by placing it on a touch panel, this shortest wavelength Λmin is in the visible light region taking into account individual differences and viewing conditions. The shortest wavelength (usually 380 nm) is set, and the interval d is usually 100 to 300 nm in consideration of variations.
The adjacent minute protrusions related to the distance d are so-called adjacent minute protrusions, which are in contact with the hem portion of the minute protrusion which is the base portion on the base material side. In the transparent conductive film according to the present invention, when the microprojections are arranged closely so that a line segment is created so as to sequentially follow the valley portions between the microprojections, a polygonal shape surrounding each microprojection in plan view A mesh-like pattern formed by connecting a large number of regions is produced. The adjacent minute protrusions related to the distance d are protrusions that share a part of the line segments constituting the mesh pattern.

When the microprotrusions are assumed to have been cut along a horizontal plane perpendicular to the depth direction of the microprotrusions, the cross-sectional area occupancy of the material portion forming the microprotrusions in the horizontal cross section is the deepest from the top of the microprotrusions. Since it has a structure that gradually increases gradually as it approaches the part direction, it exhibits an antireflection effect. This is because an abrupt and discontinuous change in refractive index between the fine concavo-convex structure and the outside (usually air) can be changed to a continuous and gradually changing refractive index change. Since light reflection is a phenomenon caused by a sudden and rapid change in refractive index at the material interface, the refractive index change on the surface of the transparent conductive film is made to change spatially and continuously. This is because light reflection on the surface of the transparent conductive film is reduced.
The fine concavo-convex structure is usually transparent and allows light to pass therethrough, but even an opaque object can provide an antireflection effect that reduces surface reflection.
Each of the microprotrusions is produced so that the cross-sectional area gradually decreases toward the tip side from the base material so as to be planted on the base material (so that it tapers). For example, hemispheres, spheroid semi-circular shapes, and cones such as cones and quadrangular pyramids are exemplified.

It is preferable that at least a part of the microprotrusions have a plurality of apexes (hereinafter sometimes referred to as “multimodal microprotrusions”). By including multimodal microprotrusions as the microprotrusions, the antireflection transparent conductive film of the present invention is further improved in antireflection and adhesion. Note that a microprojection having only one apex may be referred to as a “unimodal microprojection” in comparison with a multimodal microprojection. In addition, each convex portion forming each top portion related to a multi-peak microprojection and a single-peak microprojection is appropriately referred to as a “peak”.
When the microprotrusions are multimodal microprotrusions, the valley bottom does not include the recesses between the tops of the multimodal microprotrusions, and means the recesses between the microprotrusions. Moreover, the top of the multimodal microprotrusion means the highest top of the plurality of tops.
In addition, in order to form multi-peaked microprotrusions on the outermost layer surface on the second transparent conductive layer side, in the fine concavo-convex structure, the first transparent conductive layer and the second transparent conductive layer are laminated and then multi-peaked. It is preferable to form multi-peaked micro-projections so as to form a characteristic micro-projection.

FIG. 5 is a cross-sectional view (FIG. 5 (a)), a perspective view (FIG. 5 (b)), and a plan view (FIG. 5 (c)) for explaining the multi-peak microprotrusions having a plurality of vertices. . Note that FIG. 5 is a diagram schematically showing for easy understanding, and FIG. 5A is a diagram showing a cross section by a broken line connecting the vertices of continuous minute protrusions. 5B and 5C, the xy direction is the in-plane direction of the substrate 1, and the z direction is the height direction of the microprojections. On the outermost layer surface 11 on the second transparent conductive layer side of the antireflection transparent conductive film, many microprotrusions 12 gradually cross-sectional area (surface perpendicular to the height direction ( In FIG. 5, the cross-sectional area when cut along a plane parallel to the XY plane) is reduced, and one vertex is produced. However, in some cases, as if a plurality of microprotrusions were combined, a groove g was formed at the tip, and the apex was two (12A), the apex was three (12B), Furthermore, there were those having four or more vertices (not shown). The shape of the unimodal microprotrusion 12 can be approximated by a round shape at the top like a paraboloid of revolution, or a sharp shape at the apex like a cone. On the other hand, the shape of the multimodal microprotrusions 12A and 12B is roughly approximated by a shape in which a groove-shaped recess is cut in the vicinity of the top of the single-peak microprotrusion 12 and the top is divided into a plurality of peaks. The The shape of the multi-peak microprotrusions 12A and 12B, or the vertical cross-sectional shape when cutting along a virtual cut surface including a plurality of peaks and including the height direction (Z-axis direction in FIG. 5) is the maximum point. It is a shape that is approximated by an algebraic curve Z = a ₂ X ² + a ₄ X ⁴ +... + A _2n X ²ⁿ +.

  The microprojections with different heights in the height of each microprotrusion have a broad antireflection performance, and have a wide spectral range for light with multiple wavelengths such as white light or light with a wideband spectrum. It is advantageous for realizing a low reflectance. This is because the wavelength band in which good antireflection performance can be exhibited by such a microprojection group depends not only on the distance d between adjacent projections but also on the projection height.

  In addition, when multi-peak microprojections coexist, the anti-reflection performance can be improved as compared with the case of using only single-peak micro-projections as shown in FIG. Even if the distance between adjacent protrusions is the same and the protrusion height is the same, the microprojections 5A, 5B, etc. of the microprojections have a lower light reflectance than the single-peak microprojections. This is because the multi-modal microprotrusions 5A, 5B, etc., change the effective refractive index in the height direction in the vicinity of the apex, compared to the monomodal microprotrusions below the apex (in the middle and the heel). This is because the rate is reduced.

  In addition, when multi-peaked microprojections are mixed, compared to the case of only single-peaked microprojections, the shape below the top (middle and heel) is the same as the single-peaked microprojections. Since the surface area in the vicinity of the top is increased, the adhesion is improved.

  In addition, the ratio of the number of the multimodal microprotrusions in the entire microprotrusions existing on the surface is 10% or more from the viewpoint that the multimodal microprotrusions have the effect of improving the antireflection property and the adhesion. Preferably there is. In particular, in order to sufficiently exhibit the effect of improving the antireflection and adhesion due to the multimodal microprotrusions, the ratio of the multimodal microprotrusions is preferably 30% or more, and preferably 50% or more. .

  In the microprojection group, when microprojections having the same height H are regularly arranged at a constant period, in order to obtain the antireflection effect, for example, Japanese Patent Application Laid-Open No. 50-70040, Japanese Patent No. 4632589, As disclosed in Japanese Patent No. 4270806 and the like, the adjacent protrusion interval d is a protrusion arrangement period p (d = p). Thus, when the longest wavelength in the visible light band is λmax and the shortest wavelength is λmin, the minimum necessary condition that can exhibit an antireflection effect at the longest wavelength in the visible light band is Λmin = λmax. Since p ≦ λmax, the necessary and sufficient condition for exhibiting the antireflection effect for all wavelengths in the visible light band is Λmin = λmin, and therefore p ≦ λmin.

  The wavelengths λmax and λmin may have some width depending on observation conditions, light intensity (luminance), individual differences, and the like, but are typically λmax = 780 nm and λmin = 380 nm. A preferable condition that can more reliably exhibit an antireflection effect for all wavelengths in the visible light band is d ≦ 300 nm, and a more preferable condition is d ≦ 200 nm. Note that the lower limit value of the distance d between adjacent protrusions is usually d ≧ 50 nm, preferably d ≧ 100 nm, for reasons such as the appearance of an antireflection effect and the securing of isotropic (low angle dependency) reflectance. . On the other hand, the height H of the protrusion (see FIG. 1) is H ≧ 0.2 × λmax = 156 nm (assuming λmax = 780 nm) from the viewpoint of exhibiting a sufficient antireflection effect. Further, the height H of the protrusion is usually 350 nm or less from the viewpoint of the antireflection effect.

  Further, in the minute protrusions, the aspect ratio (average protrusion height H / average adjacent protrusion interval d) is preferably 0.8 to 2.5, and more preferably 0.8 to 2.1. preferable.

  On the other hand, when the microprotrusions of the fine concavo-convex structure are irregularly arranged as in the case where the multimodal microprotrusions coexist, the adjacent protrusion interval d varies. Therefore, in such a case, the interval d is calculated as follows.

  (1) First, an in-plane arrangement of projections (planar shape of the projection arrangement) is detected using an atomic force microscope (AFM) or a scanning electron microscope (SEM).

  (2) Subsequently, a maximum point of the height of each protrusion (hereinafter simply referred to as a maximum point) is detected from the obtained in-plane arrangement. There are various methods for obtaining the maximum point, such as a method of sequentially comparing the planar view shape and the enlarged photograph of the corresponding cross-sectional shape to obtain the maximum point, and a method of obtaining the maximum point by image processing of the plan view enlarged photo. Can be applied.

  (3) Next, a Delaunay diagram with the detected maximum point as a generating point is created. Here, Delaunay diagram is obtained by dividing the Voronoi region adjacent to the Voronoi region when the Voronoi division is performed with each local maximum as the generating point, and connecting the adjacent generating points with line segments. This is a net-like figure made up of triangular aggregates. Each triangle is called a Delaunay triangle, and a side of each triangle (a line segment connecting adjacent generating points) is called a Delaunay line. FIG. 6 is a diagram in which a Delaunay diagram (a diagram represented by a white line segment) is superimposed on the original image.

  (4) Next, the frequency distribution of the line segment length of each Delaunay line, that is, the frequency distribution of the distance between adjacent maximum points (hereinafter referred to as the distance between adjacent protrusions) is obtained. FIG. 7 is a histogram of the frequency distribution created from the Delaunay diagram of FIG. In addition, as shown in FIG. 5, when a concave portion such as a groove exists at the top of the protrusion, or when the top is divided into a plurality of peaks, from the obtained frequency distribution, the top of such a protrusion is The data resulting from the fine structure in which the concave portion exists and the fine structure in which the top portion is divided into a plurality of peaks are removed, and only the data of the projection body itself is selected to create a frequency distribution.

  Specifically, a fine structure in which a concave portion exists on the top of the protrusion, or a fine structure related to a fine protrusion (multi-modal micro protrusion) in which the top is divided into a plurality of peaks has such a fine structure. From the numerical range in the case of the microprotrusions that are not (single-peak microprotrusions), the distance between adjacent local maximum points is clearly greatly different. Thus, by removing the corresponding data using this feature, only the data of the projection body itself is selected and the frequency distribution is detected. More specifically, for example, about 5 to 20 adjacent single-peaked microprojections are selected from an enlarged photograph of the microprojections (group) in plan view, and the value of the distance between adjacent maximum points is sampled. However, the frequency is excluded by excluding values that are clearly out of the numerical range obtained by sampling (usually, data having a value of 1/2 or less of the average distance between adjacent maximum points obtained by sampling). Detect distribution. In the example of FIG. 7, data having a distance between adjacent maximal points of 56 nm or less (the leftmost small mountain indicated by the arrow A) is excluded. FIG. 7 shows a frequency distribution before such exclusion processing is performed.

(5) The average value d _AVG and the standard deviation σ are determined from the frequency distribution of the adjacent protrusion intervals d thus determined. Here, when the frequency distribution obtained in this way is regarded as a normal distribution and the average value d _AVG and the standard deviation σ are obtained, the average value d _AVG = 158 nm and the standard deviation σ = 38 nm are obtained in the example of FIG. As a result, the maximum value of the distance d between adjacent protrusions is set to dmax = d _AVG + 2σ, and dmax = 234 nm in this example.

The same method is applied to define the height of the protrusion. In this case, a relative height difference of each local maximum point position from a specific reference position is acquired from the local maximum point obtained by the above (2), and is histogrammed. FIG. 8 is a diagram showing a histogram of the frequency distribution of the protrusion height H with the protrusion root position obtained in this way as a reference (height 0). The average value _HAVG of the protrusion height and the standard deviation σ are obtained from the frequency distribution based on the histogram. Here in the example of FIG. 7, the average value _H AVG = 178 nm, the standard deviation sigma = 30 nm. Thus in this example, the height of the projections is an average value _H AVG = 178 nm. In the histogram of the protrusion height H shown in FIG. 8, in the case of a multi-peak microprotrusion, the plurality of data are mixed for one protrusion because the protrusion has a plurality of apexes. Therefore, in this case, the frequency distribution is obtained by adopting, as the projection height of the microprojection, the top portion having the highest height from among the plurality of apexes belonging to the same microprojection.

If the protrusions are irregularly arranged, when this way the maximum value of the adjacent protrusions distance obtained by dmax = d AVG ₊ 2σ, average H _AVG height of projections are arranged regularly It is necessary to satisfy the above conditions. Specifically, the condition of the distance between the microprotrusions that exhibits the antireflection effect is dmax ≦ Λmin. At a minimum, the minimum necessary condition that can exhibit the antireflection effect at the longest wavelength in the visible light band is Λmin = λmax, so dmax ≦ λmax, and the antireflection effect can be achieved for all wavelengths in the visible light band. The necessary and sufficient condition is dmax ≦ λmin because Λmin = λmin. A preferable condition that can more reliably exhibit the antireflection effect for all wavelengths in the visible light band is dmax ≦ 300 nm, and a more preferable condition is dmax ≦ 200 nm. Also, dmax ≧ 50 nm is usually satisfied and dmax ≧ 100 nm is preferable because of the antireflection effect and ensuring the isotropic (low angle dependency) of the reflectance. The height of the protrusion is set to _HAVG ≧ 0.2 × λmax = 156 nm (assuming λmax = 780 nm) in order to exhibit a sufficient antireflection effect. _HAVG is preferably 350 nm or less from the viewpoint of the antireflection effect. The projection height distribution is usually 50 to 350 nm.

  The measurement results according to FIGS. 6 to 8 described above are the measurement results in the embodiment of the multi-modal microprojections having a plurality of vertices as shown in FIG. 5, and in the frequency distribution shown in FIG. Regarding the distance d (value on the horizontal axis), there are two types of maximum values, short-range maximum values of 20 nm and 40 nm and long-range maximum values of 120 nm and 164 nm. Among these maximum values, the maximum value of the long distance corresponds to the arrangement of the microprojection bodies (the part from the middle to the heel below the top part), while the maximum value of the short distance exists in the vicinity of the top part. Corresponds to the apex (peak) of. As a result, the presence of multi-peaked microprotrusions can be seen also from the frequency distribution of the distance between the maximal points.

  In addition, the reference position when measuring the height of the protrusion described above is based on the valley bottom (minimum point of height) between the adjacent minute protrusions as a reference of height 0. However, when the height of the valley bottom itself varies depending on the location (for example, as will be described later, the concave and convex shape in which the envelope surface connecting the valley bottoms between the microprotrusions undulates with a larger period than the distance between adjacent microprotrusions (1) First, the average value of the height of each valley bottom measured from the front surface or the back surface of the transparent substrate 1 is calculated within an area sufficient for the average value to converge. (2) Next, a plane having the average height and parallel to the front or back surface of the transparent substrate 1 is considered as a reference plane. (3) Then, the height of each microprotrusion from the reference surface is calculated by setting the reference surface to a height of 0 again.

  For example, as shown in FIG. 9, the height of the valley bottom between adjacent microprotrusions varies depending on the location. The envelope surface connecting the valley bottoms between the microprotrusions is larger than the distance between adjacent microprotrusions. The case where it has the uneven | corrugated shape wavy with the period P is mentioned. In other words, the envelope surface connecting the valley bottoms between the microprotrusions may have a large concavo-convex shape wavy with a period P (that is, P> λmax) equal to or longer than the longest wavelength λmax of the visible light band. The large concavo-convex shape has a constant height in only one direction (for example, the X direction) on the XY plane (see FIG. 9) parallel to the front and back surfaces of the transparent substrate 1 and in a direction perpendicular to the same (for example, the Y direction). Alternatively, the two directions (X direction and Y direction) in the XY plane may have undulations. The uneven surface 13 undulating with a period P satisfying P> λmax is superimposed on the fine uneven structure body composed of a large number of microprojections, thereby scattering the reflected light remaining without being completely prevented from being reflected by the fine uneven structure body, Residual reflected light, particularly specularly reflected light, can be made more difficult to visually recognize, and as a result, the antireflection effect can be further improved.

When the period P of the concavo-convex surface 4 has a distribution that is not constant over the front surface, the frequency distribution of the distance between the convexes is obtained for the concavo-convex surface, and the average value is P _AVG and the standard deviation is Σ. of,
P _MIN = P _AVG -2Σ
Designed as an alternative to period P with a minimum inter-protrusion distance defined as That is, the conditions that can sufficiently exhibit the scattering effect of the residual reflected light of the fine concavo-convex structure are as follows:
P _MIN > λmax
It is. Usually, P or P _MIN is 1 to 200 μm, preferably 10 to 100 μm.
In addition, the said period P can be measured by observing the transparent conductive film of this invention using the TEM photograph or SEM photograph of the vertical cross section cut | disconnected in the thickness direction.

  Further, the height difference (h in FIG. 9) of the large uneven shape undulated in the period P is preferably 10 μm or less from the viewpoint of the antireflection effect, and more preferably in the range of 500 nm to 2 μm. preferable. In addition, since the large uneven | corrugated shape which wavy with the said period P is an uneven | corrugated shape of the envelope surface which connected the valley bottom between each microprotrusion, the height waviness between the said protrusions is the valley bottom of the microprotrusion which separated 500 nm or more, for example It can be obtained by measuring the height difference of the position of the part. The position of the valley bottom of the fine protrusion can be determined by observing the transparent conductive film of the present invention using a TEM photograph or SEM photograph of a vertical section cut in the thickness direction.

<Patterning of transparent conductive layer>
In the antireflection transparent conductive film according to the present invention, the transparent conductive layer comprising the first transparent conductive layer and the second transparent conductive layer is patterned to form a transparent conductive layer forming region and a transparent conductive layer non-forming region. The transparent conductive layer is preferably used from the point that the transparent conductive layer functions as, for example, a wiring for coordinate recognition.
The method for patterning the transparent conductive layer is not particularly limited, and examples thereof include a method of performing dry etching using a photoresist.

  When patterning the transparent conductive layer, it is preferable that the fine concavo-convex structure is further removed in the transparent conductive layer non-forming region from the viewpoint of making the pattern of the transparent conductive layer inconspicuous. This is because the difference in refractive index between the transparent conductive layer non-forming region and the transparent conductive layer forming region becomes larger when the fine concavo-convex structure is still formed in the transparent conductive layer non-forming region. As a method for further removing the fine concavo-convex structure in the transparent conductive layer non-formation region, there may be mentioned a method of performing dry etching.

  Moreover, when patterning a transparent conductive layer, in the said transparent conductive layer non-formation area | region, the said transparent conductive layer non-formation area | region is the hardened | cured material of the resin composition whose refractive index difference is 0.14 or less with the said fine concavo-convex structure body It is also preferable that the transparent conductive layer pattern is less noticeable. It is particularly preferable that the resin composition to be filled has the same composition as the fine concavo-convex structure from the viewpoint of reducing the refractive index difference.

<Other layers>
The antireflection transparent conductive film of the present invention may have a fine uneven structure, a first transparent conductive layer, and a second transparent conductive layer only on one surface of a transparent substrate as shown in FIG. And it may have a fine concavo-convex structure and a transparent conductive layer on both surfaces by having the same layer constitution on the other surface of the transparent substrate.
Moreover, the anti-reflective transparent conductive film of this invention may have further another layer in the surface which does not have a fine concavo-convex structure. Other layers include, for example, a conventionally known single layer or multilayer antireflection layer, a layer imparting antiglare property (or antireflection) by light diffusion, a conventionally known hard coat layer for preventing scratches, etc. Etc.
In addition, in the antireflection transparent conductive film of the present invention, the protective film that can be peeled off is temporarily attached to the surface of the transparent conductive layer, and then stored, transported, bought and sold, post-processed or constructed, It can also be made into the form which peels and removes.

<Method for producing antireflection transparent conductive film>
Although the manufacturing method of the anti-reflective transparent conductive film of this invention will not be specifically limited if it is a method which can manufacture the transparent conductive film of this invention mentioned above, For example, (i) Fine uneven structure on a transparent base material And (ii) a production method including a step of forming a transparent conductive layer on the fine concavo-convex structure. The method for forming the transparent conductive layer in the step (ii) is as described above, and is omitted here.
Hereinafter, the formation method of the fine concavo-convex structure in the step (i) will be described in detail.

The method for forming the fine concavo-convex structure on the transparent substrate is not particularly limited. For example, first, a fine concavo-convex structure forming resin composition is applied on the transparent substrate to form the fine concavo-convex structure. After forming the fine protrusion shape of the original plate into the resin composition for forming the fine concavo-convex structure, the resin composition is cured to form a fine concavo-convex structure, and the fine concavo-convex structure and a transparent substrate are used. Examples include a method of peeling the laminate from the original plate for forming a fine concavo-convex structure.
The method of shaping the fine protrusion shape of the fine concavo-convex structure forming original plate into the fine concavo-convex structure forming resin composition and curing the resin composition is appropriately selected according to the type of the resin composition, etc. Can do.

The fine concavo-convex structure forming original plate is not particularly limited as long as it is not deformed and worn when repeatedly used, and may be made of metal or resin, Usually, metal is used suitably. This is because it is excellent in deformation resistance and wear resistance.
The surface having the fine protrusion shape of the original plate for forming a fine concavo-convex structure is not particularly limited, but is preferably made of aluminum from the viewpoint of being easily oxidized and easily processed by anodization.
Specifically, the original plate for forming a fine concavo-convex structure has high purity, for example, by sputtering or the like directly on the surface of a metal base material such as stainless steel, copper, or aluminum, or through various intermediate layers. An aluminum layer is provided, and the aluminum layer is formed with a fine protrusion shape. Before providing the aluminum layer, the base material may be formed into a super-mirror surface on the peripheral side surface by an electrolytic composite polishing method that combines electrolytic elution action and abrasion action by abrasive grains.
As a method for forming a fine protrusion shape on the original plate for forming a fine concavo-convex structure, for example, an anodic oxidation step of forming a plurality of fine holes on the surface of the aluminum layer by an anodic oxidation method, and etching the aluminum layer A first etching step for forming a tapered shape in the opening of the microhole, and a step of expanding the hole diameter of the microhole by etching the aluminum layer at an etching rate higher than the etching rate of the first etching step. It can be formed by sequentially repeating the two etching steps.

When forming the fine concavo-convex shape, a desired shape can be obtained by appropriately adjusting the purity (amount of impurities), crystal grain size, anodizing treatment and / or etching treatment conditions of the aluminum layer. More specifically, in the anodizing treatment, the micropores are formed into shapes corresponding to the target depth and microprojection shape, respectively, by managing the liquid temperature, the voltage to be applied, the time for the anodizing, and the like. Can do.
A multi-peaked microprojection shape having a plurality of vertices can also be produced by alternately repeating an anodizing process and an etching process.
In the present invention, after laminating at least the first transparent conductive layer and the second transparent conductive layer on the fine uneven structure, the outermost surface of the fine uneven structure has the specific fine unevenness. A fine concavo-convex shape is designed, and based on that, a fine concavo-convex structure forming original plate is designed.
In this way, in the fine concavo-convex structure forming original plate, a large number of fine holes whose diameters are gradually reduced in the depth direction are densely produced. In the fine concavo-convex structure manufactured using the original plate for forming the fine concavo-convex structure, a fine protrusion having a minute protrusion group that gradually decreases in diameter as it approaches the top corresponding to the fine hole is formed. The That is, the cross-sectional area occupancy of the material portion forming the microprojection in the horizontal cross section when it is assumed that the microprojection is cut in a horizontal plane orthogonal to the depth direction of the microprojection approaches the deepest portion direction from the top of the microprojection. As a result, a fine protrusion shape having a group of minute protrusions that gradually and continuously increase is formed.

In addition, the shape of the original plate for forming a fine concavo-convex structure is not particularly limited as long as a desired shape can be formed, and may be, for example, a flat plate shape or a roll shape. However, from the viewpoint of improving productivity, a roll-shaped mold (hereinafter sometimes referred to as “roll mold”) is preferable.
As the roll mold used in the present invention, for example, a cylindrical metal material is used as a base material, and the above-described aluminum layer is provided on the peripheral side surface of the base material directly or through various intermediate layers. Thus, what formed the fine uneven | corrugated shape by repeating an anodizing process and an etching process is mentioned.

In FIG. 10, when an ultraviolet curable resin composition is used as a resin composition for forming a fine concavo-convex structure and a roll die is used as a master for forming a fine concavo-convex structure, the fine concavo-convex structure is formed on a transparent substrate. An example of a forming method is shown.
In the method shown in FIG. 10, in the resin supplying step, an uncured and liquid UV curable resin composition is applied to the transparent substrate 1 in the form of a belt-like film by the die 21 to form a microprojection-shaped receiving layer 2 ′. To do. In addition, about application | coating of an ultraviolet curable resin composition, not only the case by the die | dye 21 but various methods are applicable. Subsequently, the transparent substrate 1 is pressed and pressed by the pressing roller 23 onto the peripheral side surface of the roll mold 22 which is a mold for shaping the antireflection transparent conductive film, whereby the receiving layer 2 is applied to the transparent substrate 1. In addition, the ultraviolet curable resin composition constituting the receiving layer 2 ′ is sufficiently filled in the concave portions of the fine irregularities formed on the peripheral side surface of the roll mold 22. In this state, the ultraviolet curable resin composition is cured by irradiation with ultraviolet rays, whereby the fine concavo-convex structure 2 is produced on the surface of the transparent substrate 1. Subsequently, the transparent substrate 1 is peeled from the roll die 12 through the peeling roller 24 integrally with the hardened fine uneven structure 2. If necessary, another layer such as a hard coat layer is formed on the transparent substrate 1 and then cut into a desired size to produce an antireflection transparent conductive film. As a result, the antireflection transparent conductive film sequentially shapes the fine protrusion shape produced on the peripheral side surface of the roll mold 22 which is the original plate for forming the fine concavo-convex structure on the long transparent substrate 1 made of a roll material. Efficient mass production.

  Moreover, although the above-mentioned embodiment described the case where the antireflection transparent conductive film by a film shape was produced by the shaping process using a roll metal mold | die, this invention is not limited to this, Antireflection transparent conductive film Depending on the shape of the transparent base material according to the shape, for example, when forming an antireflection transparent conductive film by processing a flat plate or a single wafer using a fine uneven structure forming original plate with a specific curved surface shape, a shaping process The step for forming a fine concavo-convex structure body can be appropriately changed according to the shape of the transparent substrate according to the shape of the antireflection transparent conductive film.

II. Touch panel The touch panel according to the present invention is a touch panel in which the electrode surfaces of two electrode films are opposed to each other at a constant interval, and at least one electrode film is
A first transparent material containing a fine concavo-convex structure containing a resin and having a fine concavo-convex shape, a combination of an organic compound and conductive metal-containing nanoparticles, or a conductive organic polymer on at least one surface of the transparent substrate. Including a conductive layer and a second transparent conductive layer containing a conductive metal oxide in this order,
The outermost layer surface on the second transparent conductive layer side has fine irregularities provided with a group of minute protrusions formed by a collection of minute protrusions, and the minute protrusions have the shortest wavelength in the wavelength band of light for antireflection. , When the maximum value of the distance d between adjacent protrusions is dmax,
dmax ≦ Λmin
And the cross-sectional area occupancy rate of the material portion forming the microprojection in the horizontal cross section when it is assumed that the microprojection is cut in a horizontal plane perpendicular to the depth direction of the microprojection is It is an antireflection transparent conductive film having a structure that gradually increases gradually as it approaches the deepest part from the top.

In the touch panel 30 according to the present invention, as shown in FIG. 11 as an example, two electrode films 10 are arranged with their electrodes facing each other at a predetermined interval G via a spacer. At least one of the two electrode films is made of the antireflection transparent conductive film according to the present invention. In particular, in the embodiment shown in FIG. 11, the two electrode films are both made of the antireflection transparent conductive film of the present invention.
In the touch panel of the present invention, at least one of the two electrode films may be the antireflection transparent conductive film according to the present invention, and the other parts are various types of conventionally known various types of touch panels. A configuration can be employed.

  In the form of FIG. 10, the two electrode films are arranged so that the electrode surfaces face each other, but are arranged so that the electrode surfaces of the two electrode films are all back as viewed from the viewer side. Alternatively, the electrode surfaces of the two electrode films may be arranged so as to be all surfaces when viewed from the viewer side. Further, the electrode surfaces of the two electrode films may be arranged so that the electrode surface of the first electrode film is the front side and the electrode surface of the second electrode film is the back side when viewed from the viewer side. good.

  Further, as described above, when the transparent conductive layer of the antireflection transparent conductive film according to the present invention is patterned and has a transparent conductive layer forming region and a transparent conductive layer non-forming region, The layer functions as a wiring for coordinate recognition, for example, and is suitably used for a capacitive touch panel.

  For example, the structure which provided the layer which provides the glare-proof property or antireflection property by light diffusion in the touchscreen surface may be sufficient. Further, a conventionally known hard coat layer may be provided on the surface of the touch panel to prevent scratches or the like regardless of the presence or absence of the antireflection layer. It is effective to provide the antireflection layer on the hard coat layer.

III. Image display device The image display device according to the present invention is a touch panel in which the electrode surfaces of two electrode films are opposed to each other at a constant interval, and at least one electrode film is
A first transparent material containing a fine concavo-convex structure containing a resin and having a fine concavo-convex shape, a combination of an organic compound and conductive metal-containing nanoparticles, or a conductive organic polymer on at least one surface of the transparent substrate. Including a conductive layer and a second transparent conductive layer containing a conductive metal oxide in this order,
The outermost layer surface on the second transparent conductive layer side has fine irregularities provided with a group of minute protrusions formed by a collection of minute protrusions, and the minute protrusions have the shortest wavelength in the wavelength band of light for antireflection. , When the maximum value of the distance d between adjacent protrusions is dmax,
dmax ≦ Λmin
And the cross-sectional area occupancy rate of the material portion forming the microprojection in the horizontal cross section when it is assumed that the microprojection is cut in a horizontal plane perpendicular to the depth direction of the microprojection is The image display surface is provided with a touch panel, which is an antireflection transparent conductive film, having a structure that gradually and gradually increases from the top toward the deepest portion.

The image display device 40 of the present invention is an image display device having a configuration in which the touch panel 30 according to the present invention is arranged on the image display surface of a display panel 41 as shown in FIG. The touch panel may be bonded to the display panel 41 via an adhesive layer, or an image display panel 41 using a flat panel display such as an LCD may be disposed with a gap between the touch panel 30 and the touch panel 30. When the touch panel 30 has the fine concavo-convex structure on the surface facing the image display surface, an image display panel 41 using a flat panel display such as an LCD is disposed with a space between the back side of the touch panel 30. It is preferable.
The image display device of the present invention may be a device having only a display function (for example, an LCD monitor, a CRT monitor, etc.), but a device having a display function as a part of the function of the device is also applicable. For example, as described later in the application, it is a PDA or a portable information terminal, a car navigation system, or the like.

  The touch panel by this invention can be used as an input means (a transparent tablet is also included) in the display part of various display apparatuses. Such a display device with an input function includes, for example, an LCD (liquid crystal display), an ELD (electroluminescent display), an FPD (flat panel display) such as a plasma display (PDP), or a CRT as a display panel. The device used. In particular, since the display is not a self-luminous type, an LCD that is relatively susceptible to deterioration in display performance due to external light is preferable in that the effect of the present invention can be obtained more greatly. The display device according to the present invention includes a display device that displays information by mechanical means such as a mechanical analog meter represented by a timepiece having hands on a dial.

  Examples of various products having a display device with an input function as described above include PDAs such as electronic notebooks or portable information terminals (devices), car navigation systems, point-of-sale (POS) terminals, portable orders Input terminal, ATM (automatic cash deposit payment machine), facsimile, landline phone terminal, mobile phone terminal, digital camera, video camera, personal computer, PC display, television receiver, TV monitor display, ticket vending machine, measuring instrument There are electronic devices such as calculators and electronic musical instruments, office machines such as copiers and ECRs (cash register machines), and electrical products such as washing machines and microwave ovens.

(Preparation of original plate for forming fine relief structure)
The polished aluminum plate having a purity of 99.50% was polished and then anodized in an electrolytic solution of 0.02 M oxalic acid aqueous solution for 120 seconds under conditions of a conversion voltage of 40 V and 20 ° C. Next, as a first etching process, an etching process was performed for 60 seconds with the electrolytic solution after anodization. Subsequently, as the second etching treatment, a pore size treatment was performed with a 1.0 M phosphoric acid aqueous solution for 150 seconds. Furthermore, the said process was repeated and these were added and implemented 5 times in total. As a result, an anodized aluminum layer having fine irregularities formed on the aluminum substrate was formed. Finally, a fluorine-based mold release agent was applied and the excess mold release agent was washed to obtain an original plate for forming a fine relief structure. The fine unevenness formed in the aluminum layer has an average distance between adjacent projections of 100 nm and an average depth of 200 nm of the microprojection structure, and a large number of micropores whose pore diameter gradually decreases in the depth direction. It was formed, and it was the fine uneven | corrugated shape in which a micropore exists so that a part of microprotrusion may become a microprotrusion which has multiple apexes.

(Preparation of resin composition for forming fine relief structure)
20 parts by weight of dipentaerythritol hexaacrylate (DPHA), 70 parts by weight of Aronix M-260 (manufactured by Toa Gosei Co., Ltd.), 10 parts by weight of hydroxyethyl acrylate, and 3 parts by weight of lucillin TPO (manufactured by BASF) as a photopolymerization initiator Were mixed to prepare an ultraviolet curable resin composition for forming a fine relief structure.

Example 1
1. Formation of fine concavo-convex structure body The resin composition for forming a fine concavo-convex structure body is formed so that the fine projection surface of the original plate for forming the fine concavo-convex structure body is covered, and the thickness of the fine concavo-convex structure body after curing is 20 μm. After coating and filling, a 80 μm thick triacetyl cellulose film (manufactured by Fuji Film Co., Ltd.) was laminated obliquely thereon as a transparent substrate, and then the bonded laminate was loaded with a rubber roller at a load of 10 N / cm 2. Crimped. After confirming that the uniform composition was applied to the entire mold, the resin composition was cured by irradiating ultraviolet rays with energy of 2000 mJ / cm 2 from the film side. Thereafter, the laminate of the transparent substrate peeled off from the mold and the fine concavo-convex structure which is a fine protrusion having an average adjacent protrusion interval of 100 nm, an average protrusion height of 200 nm, and a part of the fine protrusions having a plurality of apexes. Got.

2. Formation of the first transparent conductive layer A gravure printing method (gravure plate: cell shape) using a PEDOT: PSS dispersion (trade name Clevios, Heraeus) on the fine uneven surface of the fine uneven structure of the obtained laminate. The first transparent conductive layer was formed by 180 line / inch, plate depth 50 μm.

3. Formation of the second transparent conductive layer On the fine irregular surface of the first transparent conductive layer of the obtained laminate, ITO was sputtered at 150 ° C. using a sputtering apparatus (SMD-750; manufactured by ULVAC, Inc.). The antireflection transparent conductive film of Example 1 was obtained by forming the 2nd transparent conductive layer which consists of layers.
The average film thickness D1 of the transparent conductive layer (the total of the first transparent conductive layer and the second transparent conductive layer) at the top of the microprotrusions is 62 nm, and the average of the transparent conductive layers at half the height of the microprotrusions. The film thickness D2 was 18 nm, and the average film thickness of the transparent conductive layer in the valleys between the fine protrusions was D3.
The outermost layer surface on the second transparent conductive layer side had the fine irregularities specified in the present invention.
In addition, said D1, D2, and D3 each were calculated | required by observing using the TEM photograph of the vertical cross section cut | disconnected in the thickness direction so that the top part of a fine concavo-convex structure might be included. The measurement of D1, D2, and D3 is repeated at 10 points randomly selected from the transparent conductive film, the measured values D1, D2, and D3 are averaged (arithmetic average), and the average film thicknesses D1, D2, And D3.

(Example 2)
In Example 1, the transparent conductive layer is the same as in Example 1 except that a polyaniline dispersion (trade name Olmecon, Nissan Chemical Co., Ltd.) was used instead of the PEDOT: PSS dispersion as the first transparent conductive layer. The first transparent conductive layer was formed so as to have an average film thickness.
The average film thickness D1 of the transparent conductive layer (the total of the first transparent conductive layer and the second transparent conductive layer) at the top of the fine protrusion is 63 nm, and the average of the transparent conductive layer is ½ of the height of the fine protrusion. The film thickness D2 was 19 nm, and the average film thickness of the transparent conductive layer in the valleys between the fine protrusions was D3.
The outermost layer surface on the second transparent conductive layer side had the fine irregularities specified in the present invention.

(Example 3)
In Example 1, silver nanoparticle ink (trade name: Nanometal Ink L-Ag Series, ULVAC, Inc.) containing an organic compound and silver nanoparticles is used as the first transparent conductive layer instead of the PEDOT: PSS dispersion. The first transparent conductive layer was formed in the same manner as in Example 1 except that the gravure printing method (gravure plate: cell shape 180 line / inch, plate depth 50 μm) was used. Formed.
The average film thickness D1 of the transparent conductive layer (the total of the first transparent conductive layer and the second transparent conductive layer) at the top of the microprotrusions is 62 nm, and the average of the transparent conductive layers at half the height of the microprotrusions. The film thickness D2 was 17 nm, and the average film thickness of the transparent conductive layer in the valleys between the fine protrusions was D3.
The outermost layer surface on the second transparent conductive layer side had the fine irregularities specified in the present invention.

(Comparative Example 1)
In Example 1, the first transparent conductive layer was not formed, and only the second transparent conductive layer was replaced by the average film thickness of the transparent conductive layer of Example 1 (the total of the first transparent conductive layer and the second transparent conductive layer). An antireflective transparent conductive film of Comparative Example 1 was obtained in the same manner as in Example 1 except that a transparent conductive layer made of ITO was formed so as to have a film thickness substantially the same as the thickness of.
The average film thickness D1 of the transparent conductive layer at the top of the microprotrusions is 60 nm, the average film thickness D2 of the transparent conductive layer at half the height of the microprotrusions is 15 nm, and the transparent at the valleys between the microprotrusions. The average thickness D3 of the conductive layer was 5 nm.

(Evaluation)
The following evaluation was performed about the antireflection transparent conductive film obtained by each Example and each comparative example. The evaluation results are shown in Table 1, respectively.

<Conductivity>
The surface resistance of the antireflection transparent conductive film obtained in each Example and Comparative Example was measured by a four-terminal method (JIS K 7194). When the surface resistance required for touch panel wiring is 500Ω / □ or less, it was determined as OK.
OK: 500Ω / □ or less NG: Over 500Ω / □

<Adhesion>
About the anti-reflective transparent conductive film obtained by each Example and the comparative example, the classification | category 0-2 was set to OK determination in the crosscut method (JISK5600-5-6).
OK: Classification 0-2
NG: Classification 3-5

<Reflectance>
The transparent base of the antireflection transparent conductive film obtained in each Example and each Comparative Example through a black acrylic plate (manufactured by Nitto Jushi Kogyo Co., Ltd., product name CLAREX) via an adhesive (manufactured by Panac, product name Panaclean PDR5) The material side was bonded and the 5 ° regular reflectance was measured with a spectroscope (manufactured by Shimadzu Corporation, spectrophotometer UV-3100PC).

(Summary of results)
The antireflective transparent conductive film of the present invention obtained in Examples 1 to 3 is formed by laminating the first transparent conductive layer and the second transparent conductive layer specified in the present invention on the fine concavo-convex structure, and 2 Since the outermost layer surface on the transparent conductive layer side has the specific fine irregularities, the conductivity and adhesion were good while being excellent in antireflection properties.
On the other hand, the antireflective transparent conductive film obtained in Comparative Example 1 was inferior in antireflection performance in addition to poor adhesion of the transparent conductive layer. In the antireflective transparent conductive film obtained in Comparative Example 1, the outermost surface of the transparent conductive layer does not have the fine irregularities of the shape specified in the present invention. It is estimated that the performance was inferior.

(Example 4)
In the same manner as in Example 1, an antireflection transparent conductive film was obtained. Next, the transparent conductive layer was patterned using a photolithography method. For the plasma etching of the transparent conductive layer, a dry etcher (trade name DEA-506T, manufactured by Canon Anelva Engineering Co., Ltd.) was used, and the following plasma etching conditions (oxygen plasma, output: 50 W, gas amount: 50 sccm, gas pressure: 50 mTorr, irradiation time 5 minutes). The transparent conductive layer non-formation region was provided by plasma etching, and the fine concavo-convex structure present in the non-formation region was also removed to obtain the antireflection transparent conductive film of Example 4.
When the antireflection transparent conductive film of Example 4 was used for the touch panel, it was confirmed that the pattern of the transparent conductive layer was not noticeable.

(Example 5)
In the same manner as in Example 1, an antireflection transparent conductive film was obtained. Next, the transparent conductive layer was patterned using a photolithography method. For the plasma etching of the transparent conductive layer, a dry etcher (trade name DEA-506T, manufactured by Canon Anelva Engineering Co., Ltd.) was used, and the following plasma etching conditions (oxygen plasma, output: 50 W, gas amount: 50 sccm, gas pressure: 50 mTorr, irradiation time 5 minutes) to provide a transparent conductive layer non-formation region. Next, in the transparent conductive layer non-formation region, the fine concavo-convex structure forming resin composition is applied by gravure printing so that the wet film thickness is 10 μm, and the surface is doctored with a plastic doctor, The transparent conductive layer non-formation region was filled with the above-described resin composition for forming a fine concavo-convex structure. Thereafter, the resin composition was cured by irradiating ultraviolet rays with an energy of 2000 mJ / cm 2 to obtain an antireflection transparent conductive film of Example 5.
When the antireflection transparent conductive film of Example 5 was used for the touch panel, it was confirmed that the pattern of the transparent conductive layer was not noticeable.

DESCRIPTION OF SYMBOLS 1 Transparent base material 2 Fine uneven structure 3 1st transparent conductive layer 4 2nd transparent conductive layer 10 Antireflection transparent conductive film 21 Die 22 Roll metal mold 23 Press roller 24 Peeling roller 30 Touch panel 40 Image display apparatus 41 Image display panel

Claims (4)

A first transparent material containing a fine concavo-convex structure containing a resin and having a fine concavo-convex shape, a combination of an organic compound and conductive metal-containing nanoparticles, or a conductive organic polymer on at least one surface of the transparent substrate. Including a conductive layer and a second transparent conductive layer containing a conductive metal oxide in this order,
The outermost layer surface on the second transparent conductive layer side has fine irregularities provided with a group of minute protrusions formed by a collection of minute protrusions, and the minute protrusions have the shortest wavelength in the wavelength band of light for antireflection. , When the maximum value of the distance d between adjacent protrusions is dmax,
dmax ≦ Λmin
And the cross-sectional area occupancy rate of the material portion forming the microprojection in the horizontal cross section when it is assumed that the microprojection is cut in a horizontal plane perpendicular to the depth direction of the microprojection is An antireflection transparent conductive film having a structure that gradually and gradually increases from the top toward the deepest portion.   The antireflection transparent conductive film according to claim 1, wherein at least a part of the microprojections is a microprojection having a plurality of vertices. A touch panel in which electrode surfaces of two electrode films are opposed to each other at regular intervals, and at least one electrode film contains a resin on at least one surface of a transparent substrate and has a fine uneven shape. A fine concavo-convex structure, a first transparent conductive layer containing a combination of an organic compound and conductive metal-containing nanoparticles or a conductive organic polymer, and a second transparent conductive layer containing a conductive metal oxide are arranged in this order. Including
The outermost layer surface on the second transparent conductive layer side has fine irregularities provided with a group of minute protrusions formed by a collection of minute protrusions, and the minute protrusions have the shortest wavelength in the wavelength band of light for antireflection. , When the maximum value of the distance d between adjacent protrusions is dmax,
dmax ≦ Λmin
And the cross-sectional area occupancy rate of the material portion forming the microprojection in the horizontal cross section when it is assumed that the microprojection is cut in a horizontal plane perpendicular to the depth direction of the microprojection is A touch panel characterized by being an antireflection transparent conductive film having a structure that gradually and gradually increases from the top toward the deepest part. It is a touch panel in which the electrode surfaces of two electrode films are opposed to each other at a constant interval, and at least one of the electrode films contains a resin on at least one surface of the transparent substrate, and has a fine uneven shape. A fine concavo-convex structure having a first transparent conductive layer containing a combination of an organic compound and conductive metal-containing nanoparticles or a conductive organic polymer, and a second transparent conductive layer containing a conductive metal oxide. Including in order,
The outermost layer surface on the second transparent conductive layer side has fine irregularities provided with a group of minute protrusions formed by a collection of minute protrusions, and the minute protrusions have the shortest wavelength in the wavelength band of light for antireflection. , When the maximum value of the distance d between adjacent protrusions is dmax,
dmax ≦ Λmin
And the cross-sectional area occupancy rate of the material portion forming the microprojection in the horizontal cross section when it is assumed that the microprojection is cut in a horizontal plane perpendicular to the depth direction of the microprojection is An image display device comprising a touch panel, which is an antireflection transparent conductive film, having a structure that gradually and gradually increases as approaching from the top toward the deepest portion, on the image display surface.