JP2014089308A - Transparent conductive film with antireflection property, touch panel and image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transparent conductive film which has antireflection performance and yet has superior adhesion of a transparent conductive layer and superior stable mass productivity.SOLUTION: The transparent conductive film having antireflection properties includes a transparent base material 1, a micro-protrusion structure 2 having densely arranged micro-protrusions and a transparent conductive layer 3 which are formed on at least one surface of the transparent base material 1 in this order. The micro-protrusions satisfies a relationship expressed as dmax≤Λmin, where Λmin represents the shortest wavelength in a wavelength band of antireflection target light and dmax represents a maximum value of distance d between two adjacent micro-protrusions. Average film thickness FT1 of the transparent conductive layer at apexes of the micro-protrusions, an average film thickness FT2 of the transparent conductive layer at half height of the micro-protrusions, and an average film thickness FT3 of the transparent conductive layer at valleys of the micro-protrusions satisfy a relationship expressed as FT1<FT2<FT3. An average level difference ΔD on the surface of the transparent conductive film and the longest wavelength Λmax in the wavelength band of antireflection target light satisfy a relationship expressed as ΔD<Λmax×0.2.

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. Further, 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 between the transparent conductive film and the liquid crystal display element. It is also effective to provide

  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 Patent Document 2, a transparent conductive film having a surface following the structure is formed on a structure composed of convex portions or concave portions arranged in a large number with a fine pitch below the wavelength of visible light. In reality, it is difficult, the variation is large, stable production is difficult, and when a transparent conductive film is formed on the structure, it is composed of a plurality of convex portions or concave portions arranged at a fine pitch below the wavelength of visible light. There is a problem that the surface shape of the structure is broken and the antireflection effect is eventually reduced. In addition, when an attempt is made to form a transparent conductive film having a surface following the structure, there is a problem that the film thickness of the transparent conductive film becomes thin and the conductivity of the transparent conductive film becomes insufficient. Furthermore, as in the technique disclosed in Patent Document 2, a transparent conductive film is formed by sputtering so as to follow a structure composed of a plurality of convex portions or concave portions arranged at a fine pitch below the wavelength of visible light. When formed, there was a problem that the adhesion of the transparent conductive film was poor.

JP 2003-136625 A Japanese Patent No. 4626721

  The present invention has been made in view of the above problems, and has a transparent conductive film excellent in adhesion of the transparent conductive layer and having stable mass productivity while having antireflection performance, a touch panel using the same, and An object is to provide an image display device.

The antireflective transparent conductive film according to the present invention includes a microprojection structure in which microprojections are disposed in close contact with at least one surface of a transparent substrate, a conductive metal oxide, a conductive organic polymer, and a conductive layer. A transparent conductive layer containing at least one selected from the group consisting of conductive metal nanoparticles and conductive metal nanowires in this order,
When the shortest wavelength of the wavelength band of light for preventing reflection is Λmin and the maximum value of the adjacent protrusion interval d of the fine protrusion 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 a structure that increases gradually and gradually as it approaches the deepest part from the top,
The film thickness of the transparent conductive layer is the distance from the microprojection structure side interface of the transparent conductive layer to the transparent conductive layer surface in the normal direction to the envelope surface connecting the valley bottoms between the microprojections,
The average film thickness of the transparent conductive layer at the top of the microprotrusions is FT1, the average film thickness of the transparent conductive layer at ½ the height of the microprotrusions is FT2, and the transparent conductive film at the valleys between the microprotrusions. When the average film thickness of the layer is FT3,
FT1 <FT2 <FT3
Satisfy the relationship
When the average height difference ΔD of the surface of the transparent conductive layer is Λmax as the longest wavelength of the wavelength band of light for preventing reflection,
ΔD <Λmax × 0.2
It is characterized by satisfying the following relationship.

  In the antireflection transparent conductive film according to the present invention, it is preferable that at least a part of the microprojections are microprojections having a plurality of apexes from the viewpoint of improving the adhesion and antireflection performance of the transparent conductive layer.

In the antireflection transparent conductive film according to the present invention, the transparent conductive layer is patterned, and the embodiment having the transparent conductive layer forming region and the transparent conductive layer non-forming region is used for, for example, coordinate recognition. It is preferably used from the point of functioning as wiring.
In the transparent conductive layer non-formation region, it is preferable that the microprojection structure is further removed from the viewpoint of making the pattern of the transparent conductive layer inconspicuous.
Further, in the transparent conductive layer non-formation region, the transparent conductive layer non-formation region is filled with a cured product of a resin composition having a refractive index difference of 0.14 or less from the microprojection structure, This is preferable from the viewpoint of making the pattern of the transparent conductive layer inconspicuous.

  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.

  According to the present invention, it is possible to provide a transparent conductive film excellent in adhesion of a transparent conductive layer and having stable mass productivity while having antireflection performance, and a touch panel and an image display device using the transparent conductive film. .

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 (FIG. 3 (a)), a perspective view (FIG.3 (b)), and a top view (FIG.3 (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 a figure explaining the definition of the film thickness of the transparent conductive layer which concerns on this invention. It is the schematic which shows an example of the process of forming a microprotrusion structure in a transparent base material among the manufacturing processes of the reflection preventing 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 microprojection structure in which microprotrusions are placed in close contact with at least one surface of a transparent substrate, a conductive metal oxide, and a conductive layer. A transparent conductive layer containing at least one selected from the group consisting of conductive organic polymers, conductive metal nanoparticles, and conductive metal nanowires in this order,
When the shortest wavelength of the wavelength band of light for preventing reflection is Λmin and the maximum value of the adjacent protrusion interval d of the fine protrusion 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 a structure that increases gradually and gradually as it approaches the deepest part from the top,
The film thickness of the transparent conductive layer is the distance from the microprojection structure side interface of the transparent conductive layer to the transparent conductive layer surface in the normal direction to the envelope surface connecting the valley bottoms between the microprojections,
The average film thickness of the transparent conductive layer at the top of the microprotrusions is FT1, the average film thickness of the transparent conductive layer at ½ the height of the microprotrusions is FT2, and the transparent conductive film at the valleys between the microprotrusions. When the average film thickness of the layer is FT3,
FT1 <FT2 <FT3
Satisfy the relationship
When the average height difference ΔD of the surface of the transparent conductive layer is Λmax as the longest wavelength of the wavelength band of light for preventing reflection,
ΔD <Λmax × 0.2
It is characterized by satisfying the following relationship.

Since the antireflection transparent conductive film of the present invention has a microprojection structure in which microprojections having the specific structure are arranged in close contact with each other, the antireflection effect and the transparent conductivity at the interface between the transparent conductive layer and the substrate are included. It is an antireflective transparent conductive film that realizes an improvement in the transmittance of the film.
In the present invention, for the transparent conductive layer formed on the microprojection structure, the transparent conductive layer has a film thickness of the transparent conductive layer in a direction normal to an envelope surface connecting valleys between the microprojections. The distance from the microprojection structure side interface of the transparent conductive layer surface,
The average film thickness of the transparent conductive layer at the top of the microprotrusions is FT1, the average film thickness of the transparent conductive layer at ½ the height of the microprotrusions is FT2, and the transparent conductive film at the valleys between the microprotrusions. When the average film thickness of the layer is FT3,
FT1 <FT2 <FT3
Satisfy the relationship
When the average height difference ΔD of the surface of the transparent conductive layer is Λmax as the longest wavelength of the wavelength band of light for preventing reflection,
It is formed so as to satisfy the relationship of ΔD <Λmax × 0.2.
The transparent conductive layer formed on the microprojection structure is not formed following the structure, but the transparent conductive layer is buried in the concave portion of the microprojection structure, and the surface of the transparent conductive layer has an average height difference. By forming so as to be low, reflection at the interface between the transparent conductive layer and the substrate of the transparent conductive film is surely prevented, and the transmittance is improved by that amount, and the stable mass productivity is excellent. Furthermore, the transparent conductive layer formed on the microprojection structure is transparent by filling the concave portion of the microprojection structure with the transparent conductive layer, and the transparent conductive layer surface has a low average height difference. The film thickness of the conductive layer can be sufficiently secured and the conductivity becomes excellent, and the adhesion between the transparent conductive layer and the microprojection structure is improved.

FIG. 1 is a cross-sectional view schematically showing an example of an antireflection transparent conductive film according to the present invention. An antireflection transparent conductive film 10 shown in FIG. 1 includes a microprojection structure 2 in which microprojections are arranged in close contact with one surface of a transparent substrate 1 in order from the transparent substrate 1 side, and a transparent conductive material. Layer 3. FIG. 2 is a cross-sectional view schematically showing another example of the antireflection transparent conductive film according to the present invention. An antireflective transparent conductive film 10 shown in FIG. 2 has a microprojection structure 2 in which microprojections are arranged in close contact with one surface of a transparent substrate 1, and is on the surface of the microprojection structure 2. In addition, the transparent conductive layer 3 is provided.
Hereinafter, the transparent base material, microprojection structure, and 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.
In addition, a primer layer may be formed on the transparent base material for improving the adhesion between the transparent base material and the microprojection structure described later and thus improving the wear resistance. This primer layer only needs to have adhesiveness to both the transparent substrate and the microprojection 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.

  In addition, as shown in FIG. 2 described above, the microprojection structure described later is formed on the surface of the transparent base material by shaping one surface of the transparent base material. The transparent substrate and the microprojection structure may have a single layer structure.

<Microprojection structure>
A microprojection structure in which microprotrusions are arranged in close contact with at least one surface of the transparent substrate is provided.
The microprojection structure may be laminated as a separate layer made of a material different from the transparent base material as shown in FIG. 1, or integrated with the transparent base material as shown in FIG. May be formed.
Moreover, from the point which improves base-material surface performance, such as adhesiveness between layers, coating suitability, and surface smoothness, a microprotrusion structure is provided on at least one surface of the transparent base via one or more intermediate layers. It may be a laminated body in which are stacked.
Moreover, you may have the microprotrusion structure by which the microprotrusion was arrange | positioned closely on both surfaces of the transparent base material directly or through another layer.

The microprotrusions in the microprotrusion structure have the shortest wavelength of the wavelength band of light for preventing reflection as Λmin, and the maximum value of the adjacent protrusion interval d between the microprotrusions as 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 a structure that increases gradually and gradually as it approaches the deepest direction from the top.

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. A sudden and discontinuous change in refractive index between the microprojection structure and the outside world (usually air, but in this embodiment, a transparent conductive layer) is changed to a continuous and gradually changing refractive index change. Because it becomes possible. Reflection of light is a phenomenon caused by a sudden and sudden change in refractive index at the material interface, so that the refractive index change at the interface between the substrate and the transparent conductive layer changes continuously in space. By doing so, light reflection at the interface between the substrate and the transparent conductive layer is reduced.
The microprojection structure is usually transparent and allows light to pass therethrough. However, even if the microprojection structure is opaque, the antireflection effect of reducing the surface reflection can be obtained.
Each microprotrusion constituting the microprotrusion structure 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 (to be tapered), Specific examples of the shape include a hemisphere, a spheroid half-cut shape, and a cone shape such as a cone shape or a quadrangular pyramid shape.

  The microprotrusions are preferably those having 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”.

FIG. 3 is a cross-sectional view (FIG. 3 (a)), a perspective view (FIG. 3 (b)), and a plan view (FIG. 3 (c)) for explaining the multimodal microprotrusions having a plurality of vertices. . Note that FIG. 3 is a diagram schematically showing for easy understanding, and FIG. 3A is a diagram showing a cross-section by a broken line connecting the vertices of continuous minute protrusions. 3B and 3C, the xy direction is the in-plane direction of the substrate 1, and the z direction is the height direction of the microprojections. In the antireflection transparent conductive film 10, many microprotrusions 5 gradually have a cross-sectional area (a plane perpendicular to the height direction (a plane parallel to the XY plane in FIG. 3)) toward the apex away from the substrate 1. The cross-sectional area when cut is small, and a single 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 (5A), the apex was three (5B), Furthermore, there were those having four or more vertices (not shown). The shape of the unimodal microprotrusions 5 can be approximated by a round shape at the top, such as a paraboloid of revolution, or a pointed shape, such as a cone. On the other hand, the shape of the multimodal microprotrusions 5A and 5B is roughly approximated by a shape in which a groove-shaped recess is cut in the vicinity of the top of the monomodal microprotrusion 5 and the top is divided into a plurality of peaks. The The shape of the multi-peaked microprotrusions 5A, 5B, or the vertical cross-sectional shape when cut along a virtual cut surface including a plurality of peaks and including the height direction (Z-axis direction in FIG. 3) 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 by the multimodal microprojections, the ratio of the number of the multimodal microprojections should be 30% or more, preferably 50% or more. Is preferred.

  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.

  On the other hand, when the microprojections of the microprojection structure are irregularly arranged as in the case where the multimodal microprojections coexist, the adjacent projection interval d has a variation. 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. 4 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. 5 is a histogram of the frequency distribution created from the Delaunay diagram of FIG. In addition, as shown in FIG. 3, 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. 5, 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. 5 shows a frequency distribution before performing such exclusion processing.

(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. 6 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. 5, the mean 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 projection height H shown in FIG. 6, in the case of a multi-peak microprojection, the plurality of data are mixed for one projection because of having 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. 4 to 6 described above are the measurement results in the embodiment of the multimodal microprojection having a plurality of vertices as shown in FIG. 3, 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. 7, the height of the valley bottom between adjacent microprotrusions varies depending on the location, and 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 uneven shape has a constant height in only one direction (for example, the X direction) on the XY plane (see FIG. 7) parallel to the front and back surfaces of the transparent substrate 1 and in a direction orthogonal 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 4 wavy with a period P satisfying P> λmax is superimposed on a microprojection structure composed of a large number of microprojections, so that the reflected light remaining without being completely prevented from being reflected by the microprojection structure is scattered, 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 microprojection 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. 7) 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.

  In the microprojection structure, the aspect ratio (average projection height H / average adjacent projection spacing d) is preferably 0.8 to 2.5, and more preferably 0.8 to 2.1. preferable.

When laminating the microprojection structure as a layer separate from the transparent substrate, the microprojection structure is preferably one containing a resin, and further comprising a cured product of the resin composition. preferable. 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 because it is excellent in moldability and mechanical strength in the form of fine protrusions.
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.

<Transparent conductive layer>
In the antireflection transparent conductive film of the present invention, at least selected from the group consisting of a conductive metal oxide, a conductive organic polymer, a conductive metal nanoparticle, and a conductive metal nanowire on the microprojection structure. It has a transparent conductive layer containing one kind.
And the figure explaining the film thickness of the transparent conductive layer of this invention in FIG. 8 is shown. The transparent conductive layer 3 according to the present invention has a film thickness of the transparent conductive layer in the normal direction 7 with respect to the envelope surface 6 connecting the valley bottoms between the microprojections, and the microprojection structure side interface of the transparent conductive layer. A distance from 8 to the surface 9 of the transparent conductive layer,
The average film thickness of the transparent conductive layer at the top of the minute protrusion is FT1, the average film thickness of the transparent conductive layer at ½ (H / 2) of the height (H) of the minute protrusion is FT2, and the minute protrusion. When the average film thickness of the transparent conductive layer in the troughs is FT3,
FT1 <FT2 <FT3
Satisfy the relationship.
Furthermore, as shown in FIG. 2, the transparent conductive layer 3 according to the present invention has an average height difference ΔD on the surface of the transparent conductive layer when the longest wavelength of the wavelength band of light for preventing reflection is Λmax.
ΔD <Λmax × 0.2
It is characterized by satisfying the following relationship.

  The transparent conductive layer 3 in the present invention is not formed following the microprojection structure, but the film thickness is set to FT1 <FT2 <FT3, and the average height difference ΔD on the transparent conductive layer surface is reduced. In other words, the transparent conductive layer is formed so as to be buried in the concave portion of the microprojection structure. Thereby, it is excellent in stable mass productivity compared with the case where it forms following a microprotrusion structure, preventing the reflection in the interface of a transparent conductive film base material and a transparent conductive layer reliably. Furthermore, the transparent conductive layer formed on the microprojection structure is transparent by filling the concave portion of the microprojection structure with the transparent conductive layer, and the transparent conductive layer surface has a low average height difference. The film thickness of the conductive layer can be sufficiently secured and the conductivity becomes excellent, and the adhesion between the transparent conductive layer and the microprojection structure is improved.

Here, the average film thicknesses FT1, FT2, and FT3 of the transparent conductive layer and the average height difference ΔD of the surface of the transparent conductive layer are such that the transparent conductive film of the present invention includes the top of the microprojection structure. It can obtain | require by observing using the TEM photograph or SEM photograph of the vertical cross section cut | disconnected in the thickness direction. In addition, when there is a large undulation as shown in FIG. 7 on the envelope surface connecting the valley bottoms between the microprotrusions, the film thickness of the transparent conductive layer on the microprotrusions may be different on the left and right of the cross section of one protrusion, In such a case, it is set as the average of the film thickness in the right and left with respect to one protrusion.
FT1, FT2, and FT3, and ΔD measurement are repeated at 10 points randomly selected from the transparent conductive film, and the measured values FT1, FT2, FT3, and ΔD are averaged (arithmetic average), and the average film The thicknesses FT1, FT2, and FT3 and the average height difference ΔD are obtained.

  The surface resistance of the transparent conductive layer 3 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 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 3 is determined by four-terminal measurement (JIS K 7194).

Here, the average film thickness of the transparent conductive layer at the top of the fine protrusions may be appropriately selected according to the required surface resistance of the transparent conductive layer 3. The average film thickness FT1 and the average height difference ΔD between the transparent conductive layer surfaces are appropriately selected so that the relationship FT1 <FT2 <FT3 is satisfied.
Here, the average film thickness FT1 of the transparent conductive layer at the top of the microprojections is preferably selected from 0 to 2000 nm depending on the required surface resistance of the transparent conductive layer 3, and more preferably 0 to It is preferable to select from 1000 nm.
On the other hand, the average height difference ΔD of the transparent conductive layer surface is:
ΔD <Λmax × 0.2
Meet. That is, the surface of the transparent conductive layer of the present application indicates that it does not have the uneven structure that the surface of the microprojection structure has. The longest wavelength Λmax of the wavelength band of light for preventing reflection is set to the longest wavelength λmax (normally 780 nm) in the visible light region taking into account individual differences and viewing conditions, and ΔD is λmax (780 nm) × 0.2 = 156 nm. Less than can be used as an index.

The transparent conductive layer contains at least one selected from the group consisting of conductive metal oxides, conductive organic polymers, conductive metal nanoparticles, and conductive metal nanowires. May be. The transparent conductive layer may have a laminated structure of these materials.
The conductive metal oxide here is preferably a transparent oxide semiconductor, for example, a binary compound such as SnO ₂ , InO ₂ , ZnO and CdO, a constituent element of the binary compound, Sn, In, A ternary compound containing at least one element of Zn and Cd, or a multi-component (composite) oxide can be used. Examples of the material constituting the transparent conductive layer 3 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 oxide). Tin), 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. Moreover, you may use a conductive metal oxide as a conductive metal oxide containing nanoparticle.

  In addition, the conductive polymer is not particularly limited, and polypyrrole, polyindole, polycarbazole, polythiophene (including basic polythiophene, the same shall apply hereinafter), polyaniline, polyacetylene, polyfuran, polyparaphenylene vinylene, A chain conductive polymer such as polyazulene, polyparaphenylene, polyparaphenylene sulfide, polyisothianaphthene, and polythiazyl, and polyacene conductive polymer can also be used. 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.

The conductive metal nanoparticles used in the transparent conductive layer of the present invention are nanoparticles containing a conductive metal, and a nanoparticle partially containing a conductive metal compound such as a conductive metal oxide, Also good.
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.

  The conductive metal nanoparticles may be used by being dispersed with an organic compound such as a surfactant or a binder component. A combination of conductive metal nanoparticles and a conductive organic polymer may be used. In the case of using a combination of conductive metal nanoparticles and an organic compound, the adhesion with the micro-concave structure as a lower layer is also improved.

  The particle diameter of the conductive metal 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

  Moreover, the metal nanowire used for the transparent conductive layer of this invention means the linear structure which has a metal element as a main component. In particular, the metal nanowire in the present invention means a structure in which a large number of linear structures having a diameter from the atomic scale to the nm size are formed in a mesh shape.

  As the metal nanowire used in the present invention, in order to form a long conductive path with one metal nanowire, the average length is preferably 3 μm or more, more preferably 3 to 500 μm, particularly 3 to 300 μm. Preferably there is. In addition, the relative standard deviation of the length is preferably 40% or less. Moreover, it is preferable that an average diameter is small from a transparency viewpoint, On the other hand, the larger one is preferable from an electroconductive viewpoint. In this invention, 10-300 nm is preferable as an average diameter of metal nanowire, and it is more preferable that it is 30-200 nm. In addition, the relative standard deviation of the diameter is preferably 20% or less.

  The metal composition of the metal nanowire used in the present invention is not particularly limited and may be composed of one or more metals of noble metal elements and base metal elements, but noble metals (for example, gold, platinum, silver, palladium, rhodium, (Iridium, ruthenium, osmium, etc.) and at least one metal belonging to the group consisting of iron, cobalt, copper, and tin is preferable, and at least silver is more preferable from the viewpoint of conductivity. In order to achieve both conductivity and stability (sulfurization and oxidation resistance of metal nanowires and migration resistance), it is also preferable to include silver and at least one metal belonging to a noble metal other than silver. When the metal nanowire according to the present invention includes two or more kinds of metal elements, for example, the metal composition may be different between the inside and the surface of the metal nanowire, or the entire metal nanowire has the same metal composition. May be.

In the present invention, the means for producing the metal nanowire is not particularly limited, and for example, known means such as a liquid phase method and a gas phase method can be used. Moreover, there is no restriction | limiting in particular in a specific manufacturing method, A well-known manufacturing method can be used. For example, as a method for producing Ag nanowires, Adv. Mater. , 2002, 14, 833-837; Chem. Mater. , 2002, 14, 4736-4745, etc. As a method for producing Co nanowires, a method for producing Au nanowires is disclosed in JP 2006-233252A, and a method for producing Cu nanowires is disclosed in JP 2002-266007 A, etc. Reference can be made to Japanese Unexamined Patent Publication No. 2004-149871.
Moreover, as a metal nanowire, you may use a commercial item, for example, a silver nanowire can be obtained from Cambrios Technologies.

  The method for forming the transparent conductive layer is not particularly limited as long as it is appropriately selected depending on the material and can form the transparent conductive layer with the film thickness as described above. For example, sputtering method, ion plating method, vacuum deposition Method, gas phase method such as CVD method, ink jet printing method, screen printing method, gravure printing method, offset printing method, flexographic printing method, dispenser printing method, slit coating method, die coating method, doctor blade coating method, wire bar coating method And solution coating methods such as spin coating, dip coating, and spray coating. Among these, when a conductive metal oxide is used, a vapor phase method is preferable, and a sputtering method is particularly preferable. On the other hand, when a conductive polymer, conductive metal nanoparticles, or conductive metal nanowires are used, a solution coating method is preferable.

In the antireflection transparent conductive film according to the present invention, the transparent conductive layer is patterned, and the transparent conductive layer is for coordinate recognition, for example, having a transparent conductive layer forming region and a transparent conductive layer non-forming region. It is preferably used because it functions as a wiring.
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 microprojection 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 microprojection structure is still formed in the transparent conductive layer non-forming region. As a method for further removing the microprojection structure in the transparent conductive layer non-formation region, a method of performing dry etching and the like can be mentioned.

  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 a hardened | cured material of the resin composition whose refractive index difference is 0.14 or less with the said microprotrusion structure. 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 microprojection structure from the viewpoint of reducing the difference in refractive index.

<Other layers>
The antireflective transparent conductive film of the present invention may have a microprojection structure and a transparent conductive layer only on one surface of a transparent substrate as shown in FIG. By having the same layer structure on one surface, a transparent conductive layer may be provided on both surfaces.
Moreover, the antireflection transparent conductive film of the present invention may further have other layers on the surface not having the microprojection 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) Microprotrusion structure on a transparent base material And (ii) a manufacturing method including a step of forming a transparent conductive layer on the microprojection structure. The method for forming the transparent conductive layer in the step (ii) is as described above, and is omitted here.
Hereinafter, the method for forming the microprojection structure in the step (i) will be described in detail.

The method for forming the microprojection structure on the transparent substrate is not particularly limited. For example, the resin composition for forming the microprojection structure is first applied on the transparent substrate to form the microprojection structure. After forming the fine projection shape of the original plate into the resin composition for forming the microprojection structure, the resin composition is cured to form the microprojection structure, and the microprojection structure and the transparent substrate are formed. The method etc. which peel the laminated body from the said original plate for microprojection structure formation can be mentioned.
The method of shaping the fine projection shape of the original plate for forming the microprojection structure into the resin composition for forming the microprojection structure and curing the resin composition is appropriately selected according to the type of the resin composition, etc. Can do.

The original plate for forming the microprojection structure 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 the fine protrusion 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 the microprojection structure has high purity 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 protrusion 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 a 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 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 this manner, the microprojection structure forming original plate has a large number of micropores that are gradually reduced in the depth direction. In the microprojection structure manufactured using the microprojection structure forming original plate, a microprojection having a microprojection group that gradually decreases in diameter as it approaches the top corresponding to the micropore 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.

Further, the shape of the original plate for forming a microprojection structure is not particularly limited as long as a desired shape can be formed. For example, the shape may be a flat plate or a roll. 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. 7, when an ultraviolet curable resin composition is used as the resin composition for forming a microprojection structure and a roll mold is used as an original plate for forming the microprojection structure, the microprojection structure is formed on a transparent substrate. An example of a forming method is shown.
In the method shown in FIG. 7, in the resin supplying step, an uncured and liquid UV curable resin composition is applied to the transparent base material 1 in the form of a belt-like film by the die 11 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 11 but various methods are applicable. Subsequently, the pressure roller 13 presses and presses the transparent base material 1 against the peripheral side surface of the roll mold 12 which is the original plate for forming the microprojection structure, thereby bringing the receiving layer 2 ′ into close contact with the transparent base material 1. The fine concavo-convex recesses formed on the peripheral side surface of the roll mold 12 are sufficiently filled with the ultraviolet curable resin composition constituting the receiving layer 2 ′. In this state, the ultraviolet curable resin composition is cured by irradiation with ultraviolet rays, whereby the microprojection 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 14 together with the hardened microprojection 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 12 that is the original plate for forming the fine protrusion 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 antireflective transparent conductive film by processing a flat plate or a single wafer using a microprojection structure forming original plate with a specific curved surface shape, a shaping process The step for forming a microprojection structure and the original plate for forming a microprojection structure 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 group consisting of a microprojection structure in which microprojections are arranged in close contact with at least one surface of a transparent substrate, and a conductive metal oxide, a conductive organic polymer, conductive metal nanoparticles, and a conductive metal nanowire. A transparent conductive layer containing at least one selected from:
When the shortest wavelength in the wavelength band of light for preventing reflection is Λmin and the maximum value of the distance d between 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 a structure that increases gradually and gradually as it approaches the deepest part from the top,
The film thickness of the transparent conductive layer is the distance from the microprojection structure side interface of the transparent conductive layer to the transparent conductive layer surface in the normal direction to the envelope surface connecting the valley bottoms between the microprojections,
The average film thickness of the transparent conductive layer at the top of the microprotrusions is FT1, the average film thickness of the transparent conductive layer at ½ the height of the microprotrusions is FT2, and the transparent conductive film at the valleys between the microprotrusions. When the average film thickness of the layer is FT3,
FT1 <FT2 <FT3
Satisfy the relationship
When the average height difference ΔD of the surface of the transparent conductive layer is Λmax as the longest wavelength of the wavelength band of light for preventing reflection,
ΔD <Λmax × 0.2
It is an antireflection transparent conductive film that satisfies the following relationship.

In the touch panel 30 according to the present invention, as shown in FIG. 10 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 of FIG. 10, 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 configurations of known various types of touch panels. Can be adopted.

  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 group consisting of a microprojection structure in which microprojections are arranged in close contact with at least one surface of a transparent substrate, and a conductive metal oxide, a conductive organic polymer, conductive metal nanoparticles, and a conductive metal nanowire. A transparent conductive layer containing at least one selected from:
When the shortest wavelength of the wavelength band of light for preventing reflection is Λmin and the maximum value of the adjacent protrusion interval d of the fine protrusion 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 a structure that increases gradually and gradually as it approaches the deepest part from the top,
The film thickness of the transparent conductive layer is the distance from the microprojection structure side interface of the transparent conductive layer to the transparent conductive layer surface in the normal direction to the envelope surface connecting the valley bottoms between the microprojections,
The average film thickness of the transparent conductive layer at the top of the microprotrusions is FT1, the average film thickness of the transparent conductive layer at ½ the height of the microprotrusions is FT2, and the transparent conductive film at the valleys between the microprotrusions. When the average film thickness of the layer is FT3,
FT1 <FT2 <FT3
Satisfy the relationship
When the average height difference ΔD of the surface of the transparent conductive layer is Λmax as the longest wavelength of the wavelength band of light for preventing reflection,
ΔD <Λmax × 0.2
The image display surface is provided with a touch panel that is an antireflection transparent conductive film that satisfies the following relationship.

The image display device 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 microprojection 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 microprojection structure forming master)
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 mold release agent was applied and the excess mold release agent was washed to obtain an original plate for forming a microprojection structure. Note that the fine unevenness formed in the aluminum layer has a fine protrusion structure with an average distance between adjacent protrusions of 100 nm and an average depth of 200 nm, and a large number of fine holes whose diameter decreases gradually in the depth direction. In addition, the fine protrusions and protrusions were formed in such a manner that a part of the fine protrusions was a fine protrusion having a plurality of apexes.

(Preparation of resin composition for forming microprojection 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 microprojection structure.

Example 1
1. Formation of the microprojection structure The resin composition for forming the microprojection structure is formed so that the microprojection surface of the original plate for forming the microprojection structure is covered and the thickness of the microprojection structure 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, it is peeled off from the mold, and a laminate with a microprojection structure in which the interval between the transparent substrate and the average adjacent projection is 100 nm, the average projection height is 200 nm, and a part of the microprojections is a microprojection having a plurality of apexes Got.

2. Formation of transparent conductive layer On the microprojection surface of the microprojection structure of the obtained laminate, using a sputtering apparatus (SMD-750; made by ULVAC), ITO was sputtered at 150 ° C., and the average of the surface of the transparent conductive layer An antireflection transparent conductive film of Example 1 was obtained by forming a transparent conductive layer composed of a continuous layer of ITO having a height difference ΔD of 0 nm. The average film thickness FT1 of the transparent conductive layer at the top of the microprojections is 10 nm, the average film thickness FT2 of the transparent conductive layer at half the height of the microprojections is 110 nm, and the valleys between the microprojections The average film thickness of the transparent conductive layer was FT3 of 210 nm.
Note that ΔD, FT1, FT2, and FT3 were each determined by observing using a TEM photograph of a vertical section cut in the thickness direction so as to include the top of the microprojection structure. FT1, FT2, and FT3, and ΔD measurement are repeated at 10 points randomly selected from the transparent conductive film, and the measured values FT1, FT2, FT3, and ΔD are averaged (arithmetic average), and the average film The thicknesses FT1, FT2, and FT3 and the average height difference ΔD were determined.

(Example 2)
In Example 1, the reflection of Example 2 was performed in the same manner as Example 1 except that a transparent conductive layer composed of a continuous ITO layer having an average height difference ΔD of 50 nm was formed as the transparent conductive layer. A protective transparent conductive film was obtained.
The average film thickness FT1 of the transparent conductive layer at the top of the microprojections is 9 nm, the average film thickness FT2 of the transparent conductive layer at half the height of the microprojections is 90 nm, and the valleys between the microprojections FT3 of the average film thickness of the transparent conductive layer was 159 nm.

(Examples 3 to 6)
In Example 1, as the transparent conductive layer, the transparent conductive layer composed of a continuous layer of ITO so that the average height difference ΔD on the surface of the transparent conductive layer becomes the value described in Table 1 and FT1 <FT2 <FT3 is satisfied. The antireflection transparent conductive film of Examples 3-6 was obtained like Example 1 except having formed.

(Comparative Example 1)
In Example 1, the reflection of Comparative Example 1 was performed in the same manner as in Example 1 except that a transparent conductive layer composed of a continuous ITO layer having an average height difference ΔD of 160 nm was formed as the transparent conductive layer. A protective transparent conductive film was obtained.
Although FT1 <FT2 <FT3 was satisfied, ΔD exceeds the value of the longest visible light wavelength of 780 nm × 0.2.

(Comparative Example 2)
In Example 1, the reflection of Comparative Example 2 was performed in the same manner as in Example 1 except that a transparent conductive layer composed of a continuous ITO layer having an average height difference ΔD of 180 nm was formed as the transparent conductive layer. A protective transparent conductive film was obtained.
The average film thickness FT1 of the transparent conductive layer at the top of the microprojections is 2 nm, the average film thickness FT2 of the transparent conductive layer at half the height of the microprojections is 3 nm, and the valleys between the microprojections. The average film thickness of the transparent conductive layer was FT3 of 22 nm.

(Example 7)
In Example 1, as the transparent conductive layer, a gravure printing method (gravure plate: gravure plate: using PEDOT: PSS dispersion (trade name Clevios, Heraeus) so that the average height difference ΔD of the transparent conductive layer surface is 50 nm. The antireflection transparent conductive film of Example 7 was obtained in the same manner as in Example 1 except that the transparent conductive layer was formed with a cell shape of 180 line / inch and a plate depth of 50 μm.
The average film thickness FT1 of the transparent conductive layer at the top of the microprojections is 2 nm, the average film thickness FT2 of the transparent conductive layer at half the height of the microprojections is 10 nm, and the valleys between the microprojections The average film thickness of the transparent conductive layer was FT3 of 152 nm.

(Example 8)
In Example 1, as the transparent conductive layer, a gravure printing method (gravure plate: gravure plate: PEDOT: PSS dispersion (trade name Crevius, Heraeus)) was used so that the average height difference ΔD of the transparent conductive layer surface was 125 nm. Cell shape 180 line / inch, plate depth 50 μm) An antireflection transparent conductive film of Example 8 was obtained in the same manner as in Example 1 except that a transparent conductive layer was formed.
The average film thickness FT1 of the transparent conductive layer at the top of the microprojections is 0 nm, the average film thickness FT2 of the transparent conductive layer at half the height of the microprojections is 5 nm, and the valleys between the microprojections. The average film thickness of the transparent conductive layer was FT3 of 75 nm.

Example 9
In Example 1, a gravure printing method (gravure plate: cell) was used as a transparent conductive layer using a polyaniline dispersion (trade name Olmecon, Nissan Chemical Co., Ltd.) so that the average height difference ΔD on the surface of the transparent conductive layer was 50 nm. The antireflection transparent conductive film of Example 9 was obtained in the same manner as in Example 1 except that the transparent conductive layer was formed with a shape of 180 line / inch and a plate depth of 50 μm.
The average film thickness FT1 of the transparent conductive layer at the top of the microprotrusions is 10 nm, the average film thickness FT2 of the transparent conductive layer at half the height of the microprotrusions is 20 nm, and the valleys between the microprotrusions are The average film thickness of the transparent conductive layer was FT3 of 160 nm.

(Example 10)
In Example 1, a gravure printing method (gravure plate: cell) was used as a transparent conductive layer using a polyaniline dispersion (trade name: Olmecon, Nissan Chemical Co., Ltd.) so that the average height difference ΔD on the surface of the transparent conductive layer was 125 nm. The antireflection transparent conductive film of Example 10 was obtained in the same manner as in Example 1 except that the transparent conductive layer was formed with a shape of 180 line / inch and a plate depth of 50 μm.
The average film thickness FT1 of the transparent conductive layer at the top of the microprotrusions is 5 nm, the average film thickness FT2 of the transparent conductive layer at half the height of the microprotrusions is 15 nm, and the troughs between the microprotrusions are The average film thickness of the transparent conductive layer was FT3 of 80 nm.

(Example 11)
In Example 1, a silver nanoparticle ink (trade name Nanometal Ink L-Ag series, ULVAC, Inc.) was used as the transparent conductive layer so that the average height difference ΔD on the surface of the transparent conductive layer was 50 nm. An antireflection transparent conductive film of Example 11 was obtained in the same manner as in Example 1 except that a transparent conductive layer was formed by a printing method (gravure plate: cell shape 180 line / inch, plate depth 50 μm).
The average film thickness FT1 of the transparent conductive layer at the top of the microprojections is 2 nm, the average film thickness FT2 of the transparent conductive layer at half the height of the microprojections is 20 nm, and the valleys between the microprojections The average film thickness of the transparent conductive layer was FT3 of 152 nm.

(Example 12)
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 microprojection structure existing in the non-formation region was also removed to obtain the antireflection transparent conductive film of Example 12.
When the antireflection transparent conductive film of Example 12 was used for the touch panel, it was confirmed that the pattern of the transparent conductive layer was not noticeable.

(Example 13)
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, the above-mentioned resin composition for forming a microprojection structure is applied to the transparent conductive layer non-formation region 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 microprojection 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 13.
When the antireflection transparent conductive film of Example 13 was used for the touch panel, it was confirmed that the pattern of the transparent conductive layer was not noticeable.

(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)
Since the antireflective transparent conductive film of the present invention obtained in Examples 1 to 11 has a transparent conductive layer having the thickness specified in the present invention on the microprojection structure, it is easy to manufacture and is stable in mass production. Excellent, excellent conductivity and adhesion. Moreover, the antireflective transparent conductive film of this invention obtained in Examples 1-11 is reduced also about 5% reflectance compared with about 15% when there is no microprotrusion structure, and antireflection performance. It was revealed that it improved.
On the other hand, Comparative Examples 1 and 2 are formed in a concavo-convex shape that can also have an antireflection effect even on the surface of the transparent conductive layer, so the reflectance is low, but the film thickness of the transparent conductive layer is thin. For this reason, the electrical conductivity tends to be insufficient, and the adhesiveness of the transparent conductive layer was poor. Further, Comparative Examples 1 and 2 had a large variation in film thickness depending on the protrusion shape in terms of manufacturing conditions, and were inferior in mass production stability.

DESCRIPTION OF SYMBOLS 1 Transparent base material 2 Microprotrusion structure 3 Transparent conductive layer 10 Antireflection transparent conductive film 11 Die 12 Roll metal mold 13 Press roller 14 Peeling roller 30 Touch panel 40 Image display apparatus 41 Display panel

Claims (7)

A group consisting of a microprojection structure in which microprojections are arranged in close contact with at least one surface of a transparent substrate, and a conductive metal oxide, a conductive organic polymer, conductive metal nanoparticles, and a conductive metal nanowire. A transparent conductive layer containing at least one selected from:
When the shortest wavelength of the wavelength band of light for preventing reflection is Λmin and the maximum value of the adjacent protrusion interval d of the fine protrusion 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 a structure that increases gradually and gradually as it approaches the deepest part from the top,
The film thickness of the transparent conductive layer is the distance from the microprojection structure side interface of the transparent conductive layer to the transparent conductive layer surface in the normal direction to the envelope surface connecting the valley bottoms between the microprojections,
The average film thickness of the transparent conductive layer at the top of the microprotrusions is FT1, the average film thickness of the transparent conductive layer at ½ the height of the microprotrusions is FT2, and the transparent conductive film at the valleys between the microprotrusions. When the average film thickness of the layer is FT3,
FT1 <FT2 <FT3
Satisfy the relationship
When the average height difference ΔD of the surface of the transparent conductive layer is Λmax as the longest wavelength of the wavelength band of light for preventing reflection,
ΔD <Λmax × 0.2
An antireflection transparent conductive film that satisfies the relationship.   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.   The antireflection transparent conductive film according to claim 1, wherein the transparent conductive layer is patterned and has a transparent conductive layer forming region and a transparent conductive layer non-forming region.   The antireflection transparent conductive film according to claim 3, wherein the microprojection structure is further removed in the transparent conductive layer non-formation region.   The antireflection transparent conductive film according to claim 3, wherein the transparent conductive layer non-formation region is filled with a cured product of a resin composition having a refractive index difference of 0.14 or less with respect to the microprojection structure. A touch panel in which the electrode surfaces of two electrode films are opposed to each other at regular intervals, and at least one electrode film is
A group consisting of a microprojection structure in which microprojections are arranged in close contact with at least one surface of a transparent substrate, and a conductive metal oxide, a conductive organic polymer, conductive metal nanoparticles, and a conductive metal nanowire. A transparent conductive layer containing at least one selected from:
When the shortest wavelength of the wavelength band of light for preventing reflection is Λmin and the maximum value of the adjacent protrusion interval d of the fine protrusion 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 a structure that increases gradually and gradually as it approaches the deepest part from the top,
The film thickness of the transparent conductive layer is the distance from the microprojection structure side interface of the transparent conductive layer to the transparent conductive layer surface in the normal direction to the envelope surface connecting the valley bottoms between the microprojections,
The average film thickness of the transparent conductive layer at the top of the microprotrusions is FT1, the average film thickness of the transparent conductive layer at ½ the height of the microprotrusions is FT2, and the transparent conductive film at the valleys between the microprotrusions. When the average film thickness of the layer is FT3,
FT1 <FT2 <FT3
Satisfy the relationship
When the average height difference ΔD of the surface of the transparent conductive layer is Λmax as the longest wavelength of the wavelength band of light for preventing reflection,
ΔD <Λmax × 0.2
A touch panel characterized by being an antireflection transparent conductive film that satisfies the following relationship. A touch panel in which the electrode surfaces of two electrode films are opposed to each other at regular intervals, and at least one electrode film is
A group consisting of a microprojection structure in which microprojections are arranged in close contact with at least one surface of a transparent substrate, and a conductive metal oxide, a conductive organic polymer, conductive metal nanoparticles, and a conductive metal nanowire. A transparent conductive layer containing at least one selected from:
When the shortest wavelength of the wavelength band of light for preventing reflection is Λmin and the maximum value of the adjacent protrusion interval d of the fine protrusion 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 a structure that increases gradually and gradually as it approaches the deepest part from the top,
The film thickness of the transparent conductive layer is the distance from the microprojection structure side interface of the transparent conductive layer to the transparent conductive layer surface in the normal direction to the envelope surface connecting the valley bottoms between the microprojections,
The average film thickness of the transparent conductive layer at the top of the microprotrusions is FT1, the average film thickness of the transparent conductive layer at ½ the height of the microprotrusions is FT2, and the transparent conductive film at the valleys between the microprotrusions. When the average film thickness of the layer is FT3,
FT1 <FT2 <FT3
Satisfy the relationship
When the average height difference ΔD of the surface of the transparent conductive layer is Λmax as the longest wavelength of the wavelength band of light for preventing reflection,
ΔD <Λmax × 0.2
The image display apparatus which equipped the image display surface with the touchscreen which is the antireflection transparent conductive film which satisfy | fills the relationship which becomes.