JP2016051455A - Conductive pattern sheet, touch panel device, and image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively prevent visibility of a conductive pattern.SOLUTION: A conductive pattern sheet 10 includes a conductive pattern 20 having metal conductors 23a, 25a and a visual function layer 40 layered on the conductive pattern 20. The visual function layer 40 comprises a binder resin 41, and particles 42 dispersed in the binder resin 41 and having a refractive index different from that of the binder resin 41. The particles 42 have an average particle diameter Dlarger than average line widths W, Wof the metal conductors 23a, 25a.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a conductive pattern sheet having a visual function layer, and more particularly to a conductive pattern sheet that can effectively prevent the conductive pattern from being visually recognized. The present invention also relates to a touch panel device and an image display device having the conductive pattern sheet.

  Conventionally, a conductive pattern having visible light permeability has been widely used in various fields as an electrode substrate for a touch panel, a transparent antenna, an electromagnetic wave shielding material (electromagnetic wave shielding sheet), and the like. While such a conductive pattern is formed by using an opaque metal material itself, it is used for many applications, for example, an electrode substrate for a touch panel and an electromagnetic wave shielding material (electromagnetic wave shielding sheet) disposed on a display device. ) Is required to be sufficiently invisible. In particular, when the pattern of the conductive mesh comes to be partially visible, not only the transmittance is lowered, but also, for example, when overlapping with other members, there are problems such as uneven shading, flickering, and moire. It will cause.

  Patent Document 1 discloses a touch screen sensor in which a conductive pattern is laminated with a micropattern obscuring structure such as a polarizer, a contrast filter, a light scattering element, anti-glare, and a matte finish, thereby reducing the visibility of the conductive pattern. Is disclosed.

  Patent Document 2 has a microlens formed so as to correspond to the conductive pattern so that an erecting virtual image of the conductive pattern with a magnification of 1 or less is formed. A touch panel in which the line width of the conductive pattern is reduced is disclosed.

Special table 2011-517355 JP2013-222456A

  In the touch screen sensor disclosed in Patent Document 1, the conductive pattern is obscured by a micropattern obscuring structure such as a polarizer, a contrast filter, a light scattering element, anti-glare, and a matte finish. The emitted image light is also obscured, and the resolution of the display is lowered.

  In the touch panel disclosed in Patent Document 2, although the line width of the conductive pattern visually recognized is reduced by the microlens, the conductive pattern is still visually recognized, and the visibility of the conductive pattern can be sufficiently reduced. It wasn't possible.

  The present invention has been made in consideration of the above points, and an object thereof is to effectively prevent a conductive pattern from being visually recognized in a conductive pattern sheet.

The conductive pattern sheet according to the present invention is:
A conductive pattern having metal conductors;
A visual functional layer laminated with the conductive pattern,
The visual functional layer includes a binder resin and particles dispersed in the binder resin and having a refractive index different from that of the binder resin,
The average particle diameter of the particles is larger than the average line width of the metal conductor.

  In the conductive pattern sheet according to the present invention, the average particle diameter of the particles may be larger than twice the average line width of the metal conductor.

  In the conductive pattern sheet according to the present invention, the thickness of the visual functional layer may be larger than the average particle diameter of the particles and smaller than twice the average particle diameter of the particles.

  In the conductive pattern sheet according to the present invention, the refractive index of the particles may be lower than the refractive index of the binder resin.

  In the conductive pattern sheet according to the present invention, at least a part of the conductive pattern may enter the binder resin.

  The conductive pattern sheet according to the present invention further includes a base material that supports the conductive pattern, and the visual function layer is laminated from a side opposite to the surface of the conductive pattern facing the base material, and the visual function layer A part thereof may be in contact with the substrate.

  A touch panel device according to the present invention includes the above-described conductive pattern sheet.

  An image display device according to the present invention includes the above-described conductive pattern sheet.

  According to the present invention, it is possible to effectively prevent the conductive pattern from being visually recognized in the conductive pattern sheet.

FIG. 1 is a plan view illustrating an electrode substrate for a touch panel having a conductive pattern sheet as viewed from a direction perpendicular to the plate surface of the electrode substrate for a touch panel, for explaining an embodiment according to the present invention. It is. FIG. 2 is an enlarged view of a part of the electrode substrate for a touch panel in FIG. 1 and is an enlarged view showing an example of the conductive pattern in the conductive pattern sheet. FIG. 3 is a diagram showing in further detail the shape of the conductive thin wire group forming the conductive pattern by further expanding the conductive pattern and the extraction wiring of FIG. FIG. 4 is an enlarged view showing another example of the conductive pattern. FIG. 5 is a diagram showing in further detail the shape of the conductive mesh forming the conductive pattern by further expanding the conductive pattern and the extraction wiring of FIG. FIG. 6 is a partially enlarged view illustrating a method for measuring the average line width of the metal conductors forming the conductive mesh of FIG. FIG. 7 is a cross-sectional view of an electrode substrate for a touch panel having a conductive pattern sheet. FIG. 8 is an enlarged view of a part of the cross-sectional view shown in FIG. FIG. 9 is a cross-sectional view showing a modification of the electrode substrate for a touch panel having a conductive pattern sheet.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings attached to the present specification, for the sake of illustration and ease of understanding, the scale, the vertical / horizontal dimension ratio, and the like are appropriately changed and exaggerated from those of the actual product.

  In this specification, the terms “plate”, “sheet”, and “film” are not distinguished from each other only based on the difference in designation. For example, the “conductive pattern sheet” is a concept including a member that can be called a plate or a film. Therefore, the “conductive pattern sheet” is a “conductive pattern plate (substrate)” or “conductive pattern”. It cannot be distinguished from a member called “film” only by the difference in designation.

  In addition, “sheet surface (plate surface, film surface)” means a target sheet-like member (plate-like) when the target sheet-like (plate-like, film-like) member is viewed as a whole and globally. It refers to the surface that coincides with the plane direction of the member or film-like member.

  Furthermore, as used in this specification, the shape and geometric conditions and the degree thereof are specified. For example, terms such as “parallel”, “orthogonal”, “identical”, length and angle values, etc. Without being bound by meaning, it should be interpreted including the extent to which similar functions can be expected.

  FIGS. 1-9 is a figure for demonstrating one Embodiment and its modification by this invention. The conductive pattern sheet 10 according to the present embodiment has a conductive pattern 20 having metal conductive wires 23 a and 25 a and a visual function layer 40 laminated with the conductive pattern 20. The conductive pattern 20 has conductivity, exhibits some function related to conductivity, and has visible light permeability. Examples of the conductive pattern 20 include a touch panel electrode substrate incorporated in a touch panel device, an electromagnetic wave shielding material that shields electromagnetic waves, an antenna having visible light permeability, and a heat generation electrode for preventing condensation. In many cases, the conductive pattern 20 is formed on the transparent substrate 30 to form the conductive pattern sheet 10 together with the transparent substrate 30.

  Below, with reference to FIGS. 1-9, the example in which the electroconductive pattern sheet 10 is integrated in the electrode substrate 11 for touchscreens is demonstrated. FIG. 1 is a plan view showing an electrode substrate 11 for a touch panel in which a conductive pattern sheet 10 is incorporated. 2 and 3 are enlarged views of a part of the touch panel electrode substrate 11 of FIG. 1, and are diagrams for explaining an example of the conductive pattern 20. FIGS. 4 to 6 illustrate the conductive pattern 20. It is a figure for demonstrating the other example of. FIG. 7 is a cross-sectional view of the electrode substrate 11 for a touch panel having the conductive pattern sheet 10.

  As shown in FIG. 7, the touch panel electrode substrate 11 in the illustrated embodiment has a transparent cover 62, a bonding layer 61, and a conductive pattern sheet 10 in order from the viewer side (upper side in FIG. 7). ing. The conductive pattern sheet 10 has a conductive pattern 20 having metal conductive wires 23 a and 25 a and a visual function layer 40 laminated with the conductive pattern 20. In the illustrated example, the conductive pattern sheet 10 further includes a transparent substrate 30.

  The transparent cover 62 is a translucent layer that functions as a dielectric, and functions as an input surface (touch surface, contact surface) to the touch panel device. The transparent cover 62 is formed from, for example, a glass plate or a resin film. The transparent cover 62 preferably has a transmittance in the visible light region of 80% or more, and more preferably 84% or more. Note that the visible light transmittance of the transparent cover 62 is measured using a spectrophotometer (manufactured by Shimadzu Corporation “UV-3100PC”, JIS K0115 compliant product) within a measurement wavelength range of 380 nm to 780 nm. It is specified as an average value of transmittance at a wavelength.

  The transparent cover 62 is bonded to the conductive pattern sheet 10 via the bonding layer 61. As such a bonding layer 61, a layer made of a material having various adhesiveness or tackiness can be used. As a typical joining layer, the layer which consists of an acrylic adhesive or an acrylic adhesive can be illustrated.

  The touch panel electrode substrate 11 is not limited to the illustrated example, and may be provided with other functional layers expected to exhibit a specific function. Further, one functional layer may exhibit two or more functions, and for example, a function may be imparted to the transparent base material 30 and other layers (the transparent cover 62 and the bonding layer 61). Good. Examples of functions that can be imparted to the electrode substrate 11 for the touch panel include antiglare (AG) function, antireflection (AR) function, hard coat (HC) function having scratch resistance, antistatic (AS) function, Examples thereof include an electromagnetic wave shielding function, an infrared shielding function, an ultraviolet shielding function, a phase difference function, a polarization function, and an antifouling function.

  Next, the conductive pattern sheet 10 having the conductive pattern 20 and the visual function layer 40 will be described. As shown in FIG. 1, the touch panel electrode substrate 11 has a group of a pair of detection electrodes 21 that are spaced apart from each other along the normal direction, and each detection electrode 21 includes a conductive pattern 20. Is included. The detection electrode 21 located on the side closer to the observer is referred to as the front surface detection electrode 21s, and the detection electrode 21 located on the side away from the observer is referred to as the back surface detection electrode 21r. These are names for distinguishing the group of the pair of detection electrodes 21 for explanation, and are not called for the purpose of limiting to the exposed surface. Here, in the image display apparatus in which the touch panel device incorporating the touch panel electrode substrate 11 is installed, the side of the image observer or the touch panel operator is referred to as the front surface, and the opposite surface is referred to as the back surface.

  In the illustrated example, the electrode substrate 11 for a touch panel includes two sheets of a first transparent base material 30 on which a front surface detection electrode 21s is formed and a second transparent base material 30 on which a back surface detection electrode 21r is formed. The transparent substrate 30 may be included. Further, the present invention is not limited to this, and a single transparent base material 30 in which the front surface detection electrode 21s and the back surface detection electrode 21r are formed on both surfaces may be included.

  Each detection electrode 21s, 21r is used for position detection, and is disposed in the active area Aa1. As shown in FIG. 1, each detection electrode 21 is connected to an extraction wiring 51 disposed in the inactive area Aa2. The extraction wiring 51 includes a front surface extraction wiring 51s connected to the front surface detection electrode 21s and a back surface extraction wiring 51r connected to the back surface detection electrode 21r. Each detection electrode 21 includes a conductive pattern 20, and the conductive pattern 20 is formed by a conductive fine wire group 23 made of metal conductive wires 23a or a conductive mesh 25 made of metal conductive wires 25a as described below. However, in FIG. 1, the area | region where each detection electrode 21 is arrange | positioned is shown.

  One or two extraction wirings 51 are provided for each of the detection electrodes 21 depending on the detection method of the contact position. Each extraction wiring 51 is connected to the corresponding detection electrode 21 to form a wiring. The extraction wiring 51 extends from the corresponding detection electrode 21 to the edge of the transparent substrate 30 in the inactive area Aa2 of the transparent substrate 30. The extraction wiring 51 is connected to a control circuit (not shown) through an external connection wiring (for example, FPC) (not shown).

  The detection electrode 21 is provided to detect an electromagnetic change or a change in capacitance that occurs when an external conductor approaches the touch panel electrode substrate 11. The detection electrode 21 (21s, 21r) is composed of a conductive fine wire group 23 made of a metal conductive wire 23a or a metal conductive wire 25a made of a metal conductive wire 25a formed of a metal material with a predetermined line width and thickness. As the metal material, a highly conductive metal such as copper, gold, silver, platinum, tin, aluminum, or nickel, and an alloy containing these metals can be used.

  2 and 3 show a conductive pattern 20 having a conductive thin wire group 23 made of metal conductive wires 23a as an example of the conductive pattern 20 in the present invention. FIG. 2 is an enlarged view of a part of the touch panel electrode substrate 11 (conductive pattern sheet 10) shown in FIG. FIG. 3 is an enlarged view of the conductive pattern 20 and the extraction wiring 51 on the surface of FIG.

  In the example shown in FIG. 2, the surface extraction wiring 51s arranged in the non-active area Aa2 includes a surface wiring part 52s and a surface connection part 53s arranged at the end of the surface wiring part 52s. . The surface detection electrode 21 s includes a surface conductive thin wire group 23 s that forms the conductive pattern 20.

  FIG. 3 further shows the conductive pattern 20 and the extraction wiring 51 on the surface of FIG. As illustrated, the surface conductive thin wire group 23s extends in the first direction (X) and is arranged in a second direction (Y) that is non-parallel to the first direction (X). The metal conducting wire 23a is provided. Thereby, a gap region 24a is defined between the adjacent metal conductors 23a. The plurality of metal conductive wires 23a extend from the active area Aa1 to the inactive area Aa2 along the first direction (X), and are connected to the common surface connecting portion 53s. The surface connecting portion 53s extends in a direction non-parallel to the first direction (X) which is the longitudinal direction of the metal conducting wire 23a. In particular, the surface connecting portion 53s extends in the second direction (Y) that is the arrangement direction of the metal conductors 23a. The plurality of surface conductive thin wire groups 23s are arranged apart from each other in the second direction (Y) that is non-parallel to the first direction (X). Thereby, a gap region 24b is defined between the adjacent surface conductive thin wire groups 23s. In the illustrated example, the first direction (X) is orthogonal to the second direction (Y).

  On the other hand, as shown in FIG. 2, the back surface conductive thin wire group 23r extends in a third direction intersecting the first direction (X). The plurality of back surface conductive thin wire groups 23r are arranged away from each other in the fourth direction intersecting both the second direction (Y) and the third direction. In the illustrated example, as shown in FIG. 2, the third direction which is the longitudinal direction of the back surface conductive thin wire group 23r is parallel to the second direction (Y). The fourth direction, which is the arrangement direction of the back surface conductive thin wire group 23r, is parallel to the first direction (X). That is, the longitudinal direction of the front surface conductive thin wire group 23s and the longitudinal direction of the back surface conductive thin wire group 23r are orthogonal to each other. The arrangement direction of the front surface conductive thin wire group 23s and the arrangement direction of the back surface conductive thin wire group 23r are orthogonal to each other. However, without being limited to this example, as the electrode substrate 1 for a touch panel, the longitudinal direction of the front surface conductive thin wire group 23s and the longitudinal direction of the back surface conductive thin wire group 23r do not need to be orthogonal to each other and intersect. Just do it. Similarly, the arrangement direction of the surface conductive fine wire group 23s and the arrangement direction of the back surface conductive fine wire group 23r do not need to be orthogonal to each other, and may be crossed.

  In the example shown in FIG. 3, the metal conductor 23 a extends linearly along the first direction (X). However, the present invention is not limited to this, and the first conductive wire 23 a has a polygonal or wavy pattern. It may have an amplitude in a direction non-parallel to the direction (X), in particular in the second direction (Y), and may extend along the first direction (X).

  The metal conductive wires 23a of the conductive thin wire group 23 as described above may be formed by, for example, copper, gold, silver, platinum, tin, aluminum, nickel, or the like by vapor deposition, sputtering, foil transfer, coating, or the like. A metal film containing an alloy is formed on the transparent substrate 30, and the metal film is etched in a desired pattern, or a conductive ink (for example, copper, gold in a resin binder such as an acrylic resin or a polyester resin). Transparent substrate 30 by a conventionally known method such as a method of printing a conductive ink in which conductive metal particles such as silver, platinum, tin, aluminum and nickel are dispersed in a desired pattern on transparent substrate 30. Can be formed on top.

In the case of manufacturing a metal wire 23a by etching the metal film as described above, the line width W ₁ of the metal wire 23a will vary. Therefore, the line width _{W 1} of the metal wire 23a, to evaluate an average line width _{W ave1} the average of multiple measurements. The average line width W _ave1 is measured by measuring the line width of the metal conducting wire 23a forming the conductive thin wire group 23 at a plurality of locations expected to reflect the overall tendency of the variation in the line width. is specified as the average value of the line width W ₁ has. Specifically, the line width W ₁ of the metal wire 23a constituting the electroconductive thin line group 23, measured at 50 points randomly selected. Line width W ₁ is identified as the length between opposite edges of the metal wire 23a in the direction orthogonal to the extending direction of the metal wires 23a at each measurement point, for example, it is measured using an optical microscope. Then, the arithmetic mean value of the total of 50 measurements of the line width W _1, and the average line width W _ave1 of metal conductors 23a forming the electroconductive thin line group 23.

In the conductive thin wire group 23 having visible light permeability, it is preferable that the metal conductive wire 23a is hardly visible. On the other hand, it is preferable that the sheet resistance of the conductive thin wire group 23 is sufficiently low so that the function due to the conductivity expected of the conductive thin wire group 23 can be sufficiently exhibited. In the case of being used as the above-mentioned application, the conductive thin wire group 23 is formed from the viewpoint of effectively expressing the expected function and the conductive thin wire group 23 having sufficient transparency. It can be designed as follows. First, the average line width W _ave1 of the conductive thin wire group 23 can be 50 μm or less, preferably 30 μm or less, more preferably 15 μm or less, and even more preferably 10 μm or less. The lower limit of the average line width W _ave1 can be, for example, 1 μm or more, preferably 3 μm or more in order to avoid disconnection.

  FIGS. 4 to 6 show a conductive pattern 20 having a conductive mesh 25 made of a metal conductive wire 25a as another example of the conductive pattern 20 that can be applied to the electrode substrate for a touch panel. FIG. 4 is an enlarged view of a part of the touch panel electrode substrate 11 (conductive pattern sheet 10) shown in FIG. FIG. 5 is an enlarged view of the conductive pattern 20 on the surface of FIG.

  In the example shown in FIG. 4, the surface detection electrode 21 s includes a surface conductive mesh 25 s that forms the conductive pattern 20. The surface conductive mesh 25s is a mesh-like material in which a large number of open regions 26 are defined by a large number of metal conducting wires 25a. In particular, in the illustrated example, the surface conductive mesh 25 s is formed in a lattice-like mesh with a large number of metal conductors 25 a, thereby defining a large number of rectangular opening regions 26.

  As shown in FIG. 5, the surface conductive mesh 25 s includes a large number of conductive connection elements 28 that extend between two branch points (confluence points) 27 and define an open region 26. In particular, in the illustrated example, the surface conductive mesh 25s is configured as a collection of a large number of connecting elements 28 that form branch points 27 at both ends. That is, the surface conductive mesh 25 s is configured as a collection of a large number of connection elements 28 extending between the two branch points 27. An opening region 26 is defined by connecting the connecting element 28 at the branch point 27. In other words, one opening region 26 is defined by being surrounded and partitioned by the connecting element 28.

  The metal conductive wire 25a of the conductive mesh 25 as described above is formed by, for example, the same method as the metal conductive wire 23a of the conductive thin wire group 23 described above, that is, a metal film is formed on the transparent substrate 30, and this metal film is formed. It can be formed by a method of etching with a desired pattern or a method of printing a conductive ink on the transparent substrate 30 with a desired pattern.

As described above, the case of producing a metal wire 25a by etching a metal film, as shown in FIG. 6, the line width W ₂ of the metal wire 25a will vary. Therefore, the line width _{W 2} of the metal wires 25a, to evaluate an average line width _{W ave2} the average of multiple measurements. The average line width W _ave2 was measured by measuring the line width of the metal conducting wire 25a forming the conductive mesh 25 at a plurality of locations expected to reflect the overall tendency of the variation in the line width. It is specified as the average value of the line width W _2. Specifically, the average line width W _ave2 is specified by the following method.

As shown in FIG. 6, the metal conductor 25 a forming the conductive mesh 25 can be said to be an assembly of connection elements 28 extending between the branch points 27. Therefore, first, 30 connecting elements 28 are arbitrarily selected. Next, three intermediate points 29 located on a virtual straight line vl that connects between the pair of branch points 27 that define each connection element 28, and the intermediate point 29 that equally divides the virtual straight line vl into four parts are identified. Then, for each of the 15 connection elements selected to measure the line width W ₂ of the three intermediate points 29. Line width W ₂ is identified as the length between opposite edges of the metal wire 25a in the direction perpendicular to the virtual straight line vl passes through the midpoint 29, for example, be measured using an optical microscope. Then, the arithmetic average value of the measured values of 90 line widths W ₂ in total is defined as the average line width W _ave2 of the metal conductive wires 25 a forming the conductive mesh 25.

The conductive mesh 25 desirably has a sufficiently low surface resistance and a sufficient transparency. Therefore, the average line width W _ave2 of the metal conductor 25a of the conductive mesh 25 can be 50 μm or less, preferably 30 μm or less, more preferably 15 μm or less, and even more preferably 10 μm or less. The lower limit of the average line width W _ave2 can be, for example, 1 μm or more, preferably 3 μm or more in order to avoid disconnection. In addition, the size of one opening region 26 defined by the conductive mesh 25 formed using an opaque material can be 50 to 2000 μm. Here, the size of one opening region 26 is the average of the maximum width and the minimum width of the opening region 26 in plan view.

  Next, the base material 30 will be described. The base material 30 functions as a base material that supports the detection electrode 21 including the conductive pattern 20. In the illustrated example, the transparent base material 30 as the base material 30 functions as a base material that supports the detection electrode 21 and also functions as a dielectric in the touch panel electrode substrate 11.

  The transparent substrate 30 is not particularly limited as long as it is a transparent and electrically insulating substrate that generally transmits wavelengths in the visible light wavelength band (380 nm to 780 nm). Polyester such as polyethylene terephthalate and polyethylene naphthalate Resin, acrylic resin such as polymethyl methacrylate, polyolefin resin such as polypropylene, cellulose resin such as triacetyl cellulose (cellulose triacetate), resin sheet made of polycarbonate resin, etc., inorganic material made of glass, ceramics, etc. it can.

  Next, the visual function layer 40 will be described. The visual function layer 40 includes a binder resin 41 and particles 42 dispersed in the binder resin 41 and having a refractive index different from that of the binder resin 41.

  In the example shown in FIG. 7, the conductive pattern 20 composed of the metal conductive wires 23 a and 25 a spreads on one plane parallel to the plate surface of the base material 30. A large number of particles 42 dispersed in the binder resin 41 are provided on the viewer side (upper side in FIG. 7) of the conductive pattern 20 and the base material 30. Thereby, the particles 42 are arranged on the viewer side of the conductive pattern 20. In particular, in the illustrated example, in the direction parallel to the plate surface of the substrate 30 and perpendicular to the longitudinal direction of the metal conductors 23a and 25a, that is, in the width direction of the metal conductors 23a and 25a, the centers of the metal conductors 23a and 25a The centers of the respective particles 42 located on the viewer side of the metal conductors 23a and 25a coincide with each other.

  The particles 42 are not particularly limited as long as they are electrically insulating particles that are transparent in general terms and transmit wavelengths in the visible light wavelength band (380 nm to 780 nm). For example, styrene resin beads, acrylic resins Beads, styrene acrylic copolymer resin beads, and silicone resin beads can be used. The shape of the particles 42 is preferably spherical.

  In the illustrated example, the refractive index of the particles 42 is different from the refractive index of the binder resin 41. In particular, the refractive index of the particles 42 can be made lower than the refractive index of the binder resin 41. In this case, the refractive index of the particles 42 is preferably 0.03 or more lower than the refractive index of the binder resin 41.

In the illustrated example, the average particle diameter D _ave of the particles 42 is larger than the average line widths W _ave1 and W _ave2 of the metal conductors 23a and 25a. Preferably, the average particle diameter D _ave of the particles 42 is larger than twice the average line widths W _ave1 and W _ave2 of the metal conductors 23a and 25a. According to the particles 42 having such an average particle diameter D _ave , it is possible to effectively prevent the conductive pattern 20 from being visually recognized from the observer side of the conductive pattern sheet 10.

The average particle diameter D _ave of the particle 42 is an arithmetic average value of the diameter of the particle 42 photographed by optical microscopy or transmission electron microscopy, and is an annex to JIS Z 8901: 2006 (test powder and test particle). The arithmetic average particle diameter measured by the method defined in 1. The average particle diameter D _ave of such particles 42 is, for example, 3 μm or more and 100 μm or less, preferably 10 μm or more and 50 μm or less.

  At least a part of each of the metal conductive wires 23 a and 25 a of the conductive pattern 20 enters the binder resin 41 of the visual function layer 40. In particular, in the illustrated example, the metal conductive wires 23 a and 25 a of the conductive pattern 20 are completely embedded in the visual functional layer 40 from the surface of the visual functional layer 40 on the substrate 30 side. In other words, the binder resin 41 of the visual function layer 40 is formed by the gap region 24a between the metal conductors 23a of the conductive thin wire group 23, the gap region 24b between the conductive thin wire groups 23, or each metal of the conductive mesh 25. Each opening region 26 between the conductors 25 a is filled, and the visual function layer 40 is in surface contact with the base material 30 at the gap regions 24 a and 24 b or the opening region 26.

  The binder resin 41 is not particularly limited as long as it is a transparent and electrically insulating resin that generally transmits a wavelength in the visible light wavelength band (380 nm to 780 nm). For example, a urethane resin or an epoxy resin is used. An acrylic resin can be used.

It is preferable that the thickness T of the visual functional layer 40 along the normal direction to one plane in which the conductive pattern 20 extends is larger than the average particle diameter D _ave of the particles 41. According to the visual function layer 40 having such a thickness, the entire particles 41 can be disposed in the binder resin 41 of the visual function layer 40. In addition, the thickness T of the visual functional layer 40 is preferably smaller than twice the average particle diameter D _ave of the particles 41. According to the visual function layer 40 having such a thickness, it is possible to prevent the plurality of particles 41 from being arranged in the normal direction to one plane in which the conductive pattern 20 extends. More preferably, the thickness T of the visual functional layer 40 is larger than the average particle diameter D _{ave of} the particles 41 and smaller than twice the average particle diameter D _ave of the particles 41.

  Next, with reference to FIG. 8, the effect | action of the electroconductive pattern sheet 10 which consists of the above structures is demonstrated. FIG. 8 is an enlarged view of a part of the sectional view of the electrode substrate 11 for a touch panel having the conductive pattern sheet 10 shown in FIG.

  As described above, the refractive index of the particles 41 and the refractive index of the binder resin 41 are different. As a result, as shown in FIG. 8, the light L1 incident on the part of the surface of the particle 42 facing the metal conductors 23 a and 25 a and the part adjacent to the width direction of the metal conductors 23 a and 25 a And refracted at the interface between the binder resin 41 and the particles 41. The light L2 incident on the particle 41 travels in the particle 41 toward the observer side and on the side opposite to the side on which the light L1 is incident on the particle 41 in the width direction of the metal conductors 23a and 25a. The portion of the surface on the viewer side that is opposite to the side where the light L1 is incident on the particles 41 in the width direction of the metal conductors 23a and 25a is emitted to the binder resin 41. At this time, the light is refracted again at the interface between the particles 41 and the binder resin 41. The light L3 emitted from the particles 41 to the binder resin 41 passes through the bonding layer 61 and the transparent cover 62, and is emitted from the surface on the observer side of the electrode substrate for touch panel 11 so that it can be visually recognized by the observer. Therefore, when an observer observes the metal conductors 23a and 25a of the conductive pattern sheet 10 from the side opposite to the side facing the metal conductors 23a and 25a of the visual function layer 40, the light L3 is visually recognized. The metal conductors 23a and 25a are difficult to be visually recognized.

According to this embodiment as described above, the conductive pattern sheet 10 has the conductive pattern 20 including the metal conductive wires 23a and 25a, and the visual function layer 40 laminated with the conductive pattern 20, The visual function layer 40 includes a binder resin 41 and particles 42 dispersed in the binder resin 41 and having a refractive index different from that of the binder resin 41. The average particle diameter D _ave of the particles 42 is determined by the metal conductor 23a. , 25a is larger than the average line width W _ave1 , W _ave2 . According to such a conductive pattern sheet 10, when the metal conductors 23a and 25a are observed from the side opposite to the side facing the metal conductors 23a and 25a of the visual function layer 40, the metal conductors 23a and 25a are visually recognized. It becomes difficult. Therefore, the conductive pattern 20 is effectively prevented from being visually recognized in the conductive pattern sheet 10.

  Various modifications can be made to the above-described embodiment. Hereinafter, modified examples will be described with reference to the drawings as appropriate. In the following description and the drawings used in the following description, the same reference numerals as those used for the corresponding parts in the above embodiment are used for the parts that can be configured in the same manner as in the above embodiment. A duplicate description is omitted.

  In the above-described embodiment, one conductive pattern 20 and one visual function layer 40 are provided, but the present invention is not limited to this. A modification of the embodiment described above is shown in FIG. In the case of having a plurality of conductive patterns 20, a plurality of visual function layers 40 may be provided corresponding to each conductive pattern 20 as shown in FIG. 9. In this case, the visual functional layer 40 may be disposed on the viewer side of the conductive pattern 20 intended to be prevented from being visually recognized. For example, when this modification is applied to the electrode substrate 11 for a touch panel in which the front surface detection electrode 21s and the back surface detection electrode 21r each include the conductive pattern 20, the conductive pattern 20 and the back surface detection electrode 21r of the front surface detection electrode 21s. Both of the conductive patterns 20 can be effectively prevented from being viewed from the viewer side.

  In the above-described embodiment, the description has been mainly made of the conductive pattern sheet 10 used for the electrode substrate 11 for the touch panel. However, the present invention is not limited to this, and an electromagnetic wave shielding material that shields electromagnetic waves and an antenna having visible light permeability. Any member can be used as long as the member has a conductive pattern that exhibits some function related to conductivity, such as a heat generation electrode for preventing condensation.

  In addition, although the some modification with respect to embodiment mentioned above was demonstrated above, naturally, it is also possible to apply combining several modifications suitably.

DESCRIPTION OF SYMBOLS 10 Conductive pattern sheet | seat 11 Electrode board | substrate 20 for touchscreens Conductive pattern 21 Detection electrode 23 Conductive fine wire group 23a Metal conducting wire 24a Gap area 24b Gap area 25 Conductive mesh 25a Metal conducting wire 26 Opening area 27 Branch point 28 Connection element 29 Intermediate point 30 Base material 40 Visual functional layer 41 Binder resin 42 Particle 51 Extraction wiring 52 Wiring part 53 Connection part 61 Joining layer 62 Transparent cover Aa1 Active area Aa2 Inactive area

Claims (8)

A conductive pattern having metal conductors;
A visual functional layer laminated with the conductive pattern,
The visual functional layer includes a binder resin and particles dispersed in the binder resin and having a refractive index different from that of the binder resin,
The conductive pattern sheet, wherein an average particle diameter of the particles is larger than an average line width of the metal conductor.   The conductive pattern sheet according to claim 1, wherein an average particle diameter of the particles is larger than twice an average line width of the metal conductor.   The conductive pattern sheet according to claim 1 or 2, wherein the thickness of the visual functional layer is larger than the average particle diameter of the particles and smaller than twice the average particle diameter of the particles.   The conductive pattern sheet according to claim 1, wherein a refractive index of the particles is lower than a refractive index of the binder resin.   The electroconductive pattern sheet in any one of Claims 1-4 in which at least one part of the said electroconductive pattern has penetrated in binder resin. Further comprising a substrate supporting the conductive pattern;
The said visual function layer is laminated | stacked from the opposite side to the surface which opposes the said base material of the said electroconductive pattern, The said visual function layer is contacting the said base material in part. The electroconductive pattern sheet in any one.   A touch panel device comprising the conductive pattern sheet according to claim 1.   An image display device comprising the conductive pattern sheet according to claim 1.

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