JP2017208034A - Film base material, see-through electrode, touch panel, and display device having touch position detection function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film base material capable of sufficiently suppressing the occurrence of wrinkles when the film base material is conveyed by a roll-to-roll system.SOLUTION: A film base material 32 has a pair of main surfaces 32a and 32b. When a displacement of a probe 81 of a friction force microscope when moving the probe along the main surface on each main surface of the film base material using an environment control type unit AFM5300E made in Hitachi Hightech Science Co., Ltd. as the friction force microscope is measured at the conditions of a probe model number: SI-DF3-P3, a scanning area: 5.0[μm]×2.5 [μm], a measurement frequency: 0.5 [Hz], a probe deflection amount: -0.9977 [nm], a friction measurement set load: -0.908 [nN] and a vacuum measurement environment: 3.0×10[Pa], the value of an FFM [mv] is 12 [mv] or less.SELECTED DRAWING: Figure 7A

Description

  The present invention relates to a film substrate. The present invention also relates to a transparent electrode provided with a film substrate. The present invention also relates to a touch panel provided with a transparent electrode. The present invention also relates to a display device with a touch position detection function obtained by combining a touch panel and a display device.

  Today, touch panel devices are widely used as input means. The touch panel device includes a touch panel, a control circuit that detects a contact position on the touch panel, wiring, and an FPC (flexible printed circuit board). In many cases, the touch panel device is used together with the display device as an input means for various devices including a display device such as a liquid crystal display or an organic EL display (for example, a ticket vending machine, an ATM device, a mobile phone, a game machine). It has been. In such a device, the touch panel is arranged on the display surface of the display device, thereby enabling extremely direct input to the display device, particularly the position coordinates of the display image and information associated with the position coordinates. Input is possible. The area of the touch panel that faces the display area of the display device is transparent, and this area of the touch panel constitutes an active area that can detect the contact position (or approach position).

  As a touch panel, a projected capacitive coupling type touch panel is known. In a capacitively coupled touch panel, a parasitic capacitance is newly generated when an external conductor (typically a finger) whose position is to be detected contacts (or approaches) the touch panel via a dielectric. The position of the external conductor on the touch panel is detected on the basis of the change in capacitance caused by the parasitic capacitance. Such a projected capacitively coupled touch panel includes, for example, a transparent electrode including a transparent base material such as a PET film and a plurality of conductive patterns provided on the transparent base material. The conductive pattern is made of, for example, a transparent conductive material made of ITO (indium tin oxide) having translucency and conductivity.

  In addition, in order to reduce the electrical resistance value of the conductive pattern and thereby improve the detection accuracy of the touch position, a metal material such as silver or copper having higher conductivity than the transparent conductive material is used as a material constituting the conductive pattern. It has been proposed to use (see, for example, Patent Document 1). However, since these metal materials are opaque, when the conductive pattern is made of a metal material, the conductive pattern has an opening for transmitting the image light from the display device at an appropriate ratio. For example, the conductive pattern is composed of conductive wires arranged in a mesh shape.

  By the way, metal materials, such as copper, show a metallic luster, while having high electroconductivity. For this reason, when an untreated metal material is used as a conducting wire, the visibility of the image light from the display device is hindered by the metallic luster of the conducting wire. In particular, copper exhibits a reddish color peculiar to copper, so that it is more conspicuous than other metal materials such as silver, and this hinders the visibility of image light from the display device. In order to reduce such metallic luster peculiar to copper, for example, in the above-mentioned Patent Document 1, it is proposed to reduce the metallic luster of the conductive wire by providing a low reflective layer made of copper nitride on the surface of the metal layer. Has been.

JP 2013-169712 A

  As a method of manufacturing a flexible wiring board such as a flexible board, it is placed in a vacuum atmosphere (strictly on a long resin substrate (film substrate) supplied and transported by a roll-to-roll method. In other words, in a reduced-pressure atmosphere), the above-described low-reflection layer or metal layer is formed by a technique such as vapor deposition or sputtering to produce a long wiring board, and the wiring board is wound into a roll. Can be considered. Here, the “roll-to-roll method” means that a long belt-like flexible substrate is unwound and conveyed from a take-up (roll), supplied, subjected to predetermined processing, and then taken up ( A processing method of winding into a roll) form.

  In such a roll-to-roll system, it is known that when the friction between the film substrate and the guide roller is large, wrinkles are generated in the film substrate and the shape becomes defective. According to the knowledge of the present inventors, the following two factors can be considered as wrinkle generation factors.

  That is, in the roll-to-roll method, the film substrate is transported in a state where a constant tension is applied in the transport direction (MD direction) so as not to be bent between the guide rollers due to the influence of gravity. By applying a certain tension in the transport direction (MD direction) and pulling, a compressive force acts in the width direction (TD direction) of the film substrate. Moreover, when forming thin films, such as a metal layer, on a film base material, in order to raise the adhesiveness of a film base material and a thin film, a thin film is formed, heating a film base material. The dimension of a film base material changes with heat because a film base material is heated. Then, the film base material is deformed without being able to withstand the synergistic effect of the compressive force in the width direction (TD direction) and the dimensional change due to heat (particularly thermal expansion), and wrinkles are generated (first factor).

  In addition, even if wrinkles are temporarily generated, if the slip between the film base and the guide roller is high, it is generated by the film base trying to return to its original shape by elastic recovery force. Wrinkles can be easily eliminated. However, when the frictional force between the film base and the guide roller is larger than the elastic recovery force, the generated wrinkle is eliminated because the film base prevents the film base from returning to its original shape. Will remain in the product (second factor).

  In order to suppress the occurrence of wrinkles on the film substrate, the present inventors initially have a friction coefficient measured by a method according to JIS K7125: 1999, that is, in a standard atmosphere defined in JIS K7100: 1999. It was considered to use a film substrate having a friction coefficient within a predetermined range. However, according to actual verification by the present inventors, among the commercially available film base materials having the same friction coefficient, there are a film base material in which wrinkles are generated and a film base material in which wrinkles are not generated. I found it. In other words, it was found that the generation of wrinkles cannot be sufficiently suppressed by the method of limiting the range of the friction coefficient.

  For example, the inventors of the present invention used a frictional friction test system “Tribogear” (registered trademark) TYPE: HHS2000 manufactured by Shinto Kagaku Co., Ltd., for a plurality of commercially available film substrates in a standard atmosphere. Was measured. Thereafter, the correlation between the measured friction coefficient of each film substrate and the occurrence of wrinkles on each film substrate was examined. However, in the study by the present inventors, there was no correlation between the measured friction coefficient of each film substrate and the occurrence of wrinkles on each film substrate. That is, it was found that it is difficult to sufficiently suppress the generation of wrinkles on the film base by limiting the coefficient of friction of the film base measured in a standard atmosphere within a predetermined range. .

  Here, the inventors of the present invention have focused on the fact that when a film forming process is performed on a film substrate, the film forming process may be performed under reduced pressure such as in a vacuum. When the film forming process is performed under reduced pressure, the film substrate is conveyed while being in contact with the guide roller under reduced pressure. Further, according to further experiments by the present inventors, it has been found that no clear correlation is observed between the friction coefficient in the standard atmosphere and the friction coefficient under reduced pressure in the film substrate. That is, when a certain film substrate has a low coefficient of friction in a standard atmosphere, the film substrate does not necessarily have a low coefficient of friction even under reduced pressure. Therefore, it can be said that it is not sufficient to use the friction coefficient of the film substrate measured in a standard atmosphere in order to evaluate the slipping property between the film substrate and the guide roller under reduced pressure.

  The present invention has been made in consideration of the above points. An object of the present invention is to provide a film base material capable of sufficiently suppressing generation of wrinkles when forming a thin film while being conveyed by a roll-to-roll method, a transparent electrode provided with the film base material, a touch panel, and a touch It is to provide a display device with a position detection function.

The film substrate according to the present invention comprises:
A film substrate having a pair of main surfaces,
Displacement of the probe when the probe of the friction force microscope is moved on each main surface of the film substrate along the main surface using an environment control type unit AFM5300E manufactured by Hitachi High-Tech Science Co. as a friction force microscope. The
Probe model number: SI-DF3-P3
Scanning area: 5.0 [μm] x 2.5 [μm]
Measurement frequency: 0.5 [Hz]
Probe deflection: -0.9977 [nm]
Friction measurement setting load: -0.908 [nN]
Vacuum measurement environment: 3.0 × 10 ⁻³ [Pa]
_Is output as the product of the minute displacement ΔX [nm] of the probe and the signal difference S _FFM [mv / nm] in the horizontal direction of the detector with respect to the torsional displacement of 1 nm of the probe. The value of FFM [mv] is 12 [mv] or less.

The transparent electrode according to the present invention comprises:
Any of the film substrates according to the invention described above;
A plurality of conductive patterns provided on the film substrate;
With
The conductive pattern is a conductive wire having a light shielding property, and is composed of conductive wires arranged in a mesh shape so that openings are formed between the conductive wires.

  The touch panel according to the present invention includes the above-described transparent electrode according to the present invention.

The display device with a touch position detection function according to the present invention is
A display device;
A touch panel according to the present invention described above, disposed on the display surface of the display device;
Is provided.

  ADVANTAGE OF THE INVENTION According to this invention, when forming a thin film on a film base material, conveying by a roll-to-roll system, it can fully suppress that a wrinkle generate | occur | produces on a film base material.

FIG. 1 is a plan view showing a transparent electrode in the first embodiment of the present invention. 2A is an enlarged plan view showing a conductive pattern in a portion surrounded by an alternate long and short dash line denoted by reference numeral II in FIG. FIG. 2B is an enlarged plan view showing a modification of the conductive pattern. FIG. 3 is a cross-sectional view showing a case where the transparent electrode is cut along line III-III in FIG. 2A. FIG. 4 is an enlarged cross-sectional view of the transparent substrate and the conductor shown in FIG. FIG. 5 is a diagram for explaining a method for measuring the displacement of the probe of the frictional force microscope to obtain the value of the FFM signal of the film substrate. FIG. 6A is a diagram illustrating an example of the displacement of the probe of FIG. FIG. 6B is a diagram illustrating an example of the displacement of the probe in FIG. 5. FIG. 6C is a diagram illustrating an example of the displacement of the probe in FIG. 5. FIG. 7A is a diagram for explaining a method of manufacturing a transparent electrode. FIG. 7B is a diagram for explaining a method of manufacturing a transparent electrode. FIG. 7C is a diagram for explaining a method of manufacturing a transparent electrode. FIG. 7D is a diagram for explaining a method of manufacturing the transparent electrode. FIG. 7E is a diagram for explaining a method of manufacturing a transparent electrode. FIG. 8 is a development view showing a display device with a touch position detection function in the third embodiment of the present invention. FIG. 9 is a plan view showing a touch panel in the display device with a touch position detection function of FIG. FIG. 10 is an enlarged plan view showing a conductive pattern in a portion surrounded by a one-dot chain line denoted by reference numeral X in FIG. 11 is a cross-sectional view showing a case where the touch panel is cut along the line XI-XI in FIG. 12 is an enlarged cross-sectional view of a part of the touch panel shown in FIG. FIG. 13 is a cross-sectional view showing a modification of the touch panel according to the second embodiment of the present invention. FIG. 14 is a cross-sectional view showing a modification of the touch panel according to the second embodiment of the present invention. FIG. 15 is a diagram showing a modification of the cross-sectional shape of the conducting wire arranged on the display device side. FIG. 16 is a cross-sectional view showing a transparent electrode according to the third embodiment of the present invention. 17 is an enlarged cross-sectional view of a part of the transparent electrode shown in FIG. FIG. 18 is a graph showing FFM values in the sample of the example and the comparative sample.

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Note that, in the drawings attached to the present specification, for the sake of easy understanding of the drawings, the scale and the vertical / horizontal dimension ratio are appropriately changed and exaggerated from those of the actual ones.

<First Embodiment>
Hereinafter, the first embodiment of the present invention will be described with reference to FIGS.

  First, with reference to FIG. 1, the transparent electrode 31 provided with the film base material 32 by this Embodiment is demonstrated. FIG. 1 is a plan view showing the transparent electrode 31 when viewed from the observer side.

  Here, an example in which the transparent electrode 31 is configured for a projection-type capacitively coupled touch panel will be described. Note that the “capacitive coupling” method is also referred to as “capacitance” method, “capacitance coupling” method, or the like in the technical field of the touch panel. It is treated as a term synonymous with the “capacitive coupling” method. A typical capacitive coupling type touch panel has a conductive pattern, and when an external conductor (typically a human finger) approaches the touch panel, the electrical conductivity of the external conductor and the touch panel is reduced. A capacitor (capacitance) is formed between these patterns. Based on the change in the electrical state accompanying the formation of the capacitor, the position coordinates of the position where the external conductor is approaching on the touch panel are specified.

  As shown in FIG. 1, the transparent electrode 31 includes a film substrate 32 and a plurality of conductive patterns 41 provided on the film substrate 32. As shown in FIG. 1, each conductive pattern 41 has a rectangular outline shape, and the long side of the rectangle extends in a strip shape in the vertical direction of FIG. The plurality of conductive patterns 41 are arranged at a constant arrangement pitch in a direction orthogonal to the direction in which each conductive pattern 41 extends. The arrangement pitch of the conductive patterns 41 is determined according to the resolution required for the detection of the touch position, and is several mm, for example. In the present invention, “touch” of the touch panel means non-contact with a distance of several mm or less, except when the tip of a writing instrument such as a human finger or pencil directly contacts the touch panel or the transparent electrode. It also includes the case of close approach.

  As shown in FIG. 1, the film substrate 32 of the transparent electrode 31 includes a rectangular active area Aa1 corresponding to a region where the touch position can be detected, and a rectangular frame-shaped inactive located around the active area Aa1. Area Aa2. The active area Aa1 and the inactive area Aa2 are respectively divided in accordance with the active area and the inactive area of the display device of the display device with a touch position detection function 10 described later.

  The conductive pattern 41 described above is disposed in the active area Aa1. Further, in the inactive area Aa2, a plurality of frame wirings 43 electrically connected to each conductive pattern 41 and a plurality of frame wirings 43 arranged near the outer edge of the film base 32 and electrically connected to each frame wiring 43 are provided. Terminal portion 44.

  The frame wiring 43 and the terminal portion 44 connected to the conductive pattern 41 are provided for extracting a signal from the conductive pattern 41 to the outside of the transparent electrode 31. As long as signals can be appropriately transmitted, the specific configurations of the frame wiring 43 and the terminal portion 44 are not particularly limited. For example, the frame wiring 43 and the terminal portion 44 may be formed simultaneously with the conductive wire 51 with the same layer configuration as the conductive wire 51 described later.

  Next, the pattern shape of the conductive pattern 41 will be described with reference to FIG. 2A. 2A is a plan view showing a conductive pattern 41 in a portion surrounded by a one-dot chain line denoted by reference numeral II in FIG. As shown in FIG. 2A, the conductive pattern 41 is a conductive wire 51 having light shielding properties and electrical conductivity, and is composed of conductive wires 51 arranged in a mesh shape so that openings 51a are formed between the conductive wires 51. Has been.

  The ratio of the area occupied by the opening 51a (hereinafter referred to as the aperture ratio) in the total area of the conductive pattern 41 is sufficiently high, so that the image light from the display device can be transmitted through the transparent electrode 31 with an appropriate transmittance. As long as it can pass through the active area Aa1, the size and shape of the conducting wire 51 are not particularly limited. For example, in the example shown in FIG. 2A, the conductive pattern 41 is configured by arranging conductive wires 51 formed in a rectangular shape along a predetermined direction. The aperture ratio is appropriately set according to the characteristics of the image light emitted from the display device.

  The line width of the conducting wire 51 is set according to the required aperture ratio, the invisibility of the conductive pattern, etc. For example, the line width of the conducting wire 51 is in the range of 1 μm to 5 μm, more preferably in the range of 1 μm to 3 μm. More preferably, it is set to 2 μm or less. The arrangement pitch P1 of the conductive wires 51 extending in parallel with each other is also set according to the required aperture ratio. As a result, the influence of the conductive wire 51 on the image visually recognized by the observer can be reduced to a negligible level, that is, sufficient invisibility can be obtained.

  Although FIG. 2A shows an example in which the conductive pattern 41 is configured by arranging the conductive wires 51 whose opening portions are formed in a rectangular shape along a predetermined direction, the present invention is not limited thereto. . For example, as illustrated in FIG. 2B, the conductive pattern 41 may be configured by arranging the conductive wires 51 whose opening portions are formed in a rhombus shape along a predetermined direction. In this embodiment, as shown in FIGS. 2A and 2B, the number of openings 51a of the conductive pattern 41 is two in the direction orthogonal to the extending direction of the conductive pattern 41 (the left-right direction in the figure). However, the number of arrangements in the present invention is not limited to two, and the number is arranged as appropriate according to the resolution of detecting the position of the touch panel, the sensitivity, the invisibility of the conductive pattern, and the like.

  Next, the layer configuration of the transparent electrode 31 will be described with reference to FIGS. 3 and 4. 3 is a cross-sectional view showing a case where the transparent electrode 31 is cut along the line III-III in FIG. 2A. FIG. 4 is an enlarged cross-sectional view showing the film substrate 32 and the conductive wire 51 shown in FIG. FIG.

  As shown in FIG. 3, the transparent electrode 31 includes a transparent film substrate 32 having a pair of main surfaces 32 a and 32 b, and a conductive pattern 41 including a conductive wire 51 provided on the surface of the film substrate 32, Is included. In the present specification, “transparent” means that the light transmittance is sufficiently high and the other side can be seen through. Specifically, for example, the visible light transmittance is 50% or more, more preferably 80% or more, and still more preferably 90% or more. Moreover, it is preferable that the film base material 32 has a small haze. Specifically, for example, the haze is 1% or less, more preferably 0.5% or less. The total light transmittance is measured according to JIS K7361-1: 1997, and the haze is measured according to JIS K7136: 2000. The pair of main surfaces 32a and 32b is a polyhedron (usually a surface area of a pair of opposed surfaces that is much larger than the surface area of the other surface, as in the film substrate 32 shown in FIGS. Is a rectangular parallelepiped) means a pair of opposed surfaces having such a larger surface area than the other surfaces. Usually, the surfaces called the front surface and the back surface correspond to this. When the long belt-shaped film is conveyed by the guide roller, the surfaces that come into contact with the guide roller and are damaged or generate a frictional force with the guide roll are mainly a pair of main surfaces.

  The film substrate 32 is for supporting patterns and wiring such as the conductive pattern 41 and the frame wiring 43 described above. As shown in FIG. 4, the film base material 32 includes a transparent base material 33 that can transmit image light from the display device, and an acrylic resin provided between the transparent base material 33 and the conductive wire 51 of the conductive pattern 41. And a layer 34a. The film substrate 32 may further include an acrylic resin layer 34 b provided on the side of the transparent substrate 33 opposite to the side facing the conductive wire 51.

  As a material constituting the transparent base material 33, a material having transparency and flexibility is used, and for example, a synthetic resin (plastic) is used. Examples of synthetic resins include polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyolefin resins such as polypropylene (PP) and cycloolefin polymer (COP), polycarbonate (PC) resin, and triacetyl cellulose. A resin having flexibility and transparency such as a cellulose resin such as (TAC) is used. The thickness of the film substrate is 20 μm to 500 μm.

  The acrylic resin layers 34a and 34b have a function of improving the scratch resistance against scratches that may be caused by friction with the guide roller when the transparent electrode 31 is manufactured by the roll-to-roll method, This is a layer provided to realize a function of adjusting optical characteristics such as transmittance and reflectance.

  As a material constituting the acrylic resin layers 34a and 34b, an acrylic resin is used. As the acrylic resin, those having sufficient scratch resistance and transparency are preferable, and as a typical one satisfying these conditions, an ionizing radiation curable acrylic resin that cures by a crosslinking reaction or a polymerization reaction by ionizing radiation irradiation is used. Can be mentioned. As such an ionizing radiation curable acrylic resin, a (meth) acrylate prepolymer or a (meth) acrylate monomer having a polymerizable functional group such as a (meth) acryloyl group or a (meth) acryloyloxy group in the molecule is used. It is done. Examples of the (meth) acrylate prepolymer include prepolymers such as urethane (meth) acrylate, epoxy (meth) acrylate, and polyester (meth) acrylate. Examples of the (meth) acrylate monomer include ethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, and dipentaerythritol hexa (meth) methacrylate. Examples include a polymer. (Here, “(meth) acryloyl group”, “(meth) acrylate” and the like mean “acryloyl group or methacryloyl group” and “acrylate or methacrylate”, respectively). These prepolymers and monomers are Depending on the required performance such as scratch resistance, flexibility, coating suitability, etc., one or more of the above prepolymers may be mixed as appropriate, and the above monomers may be used alone or in combination of two or more. Alternatively, one or more of the above prepolymers and one or more of the above monomers may be mixed and used. When ultraviolet rays or visible rays are used as ionizing radiation, photoinitiators such as benzotriazole compounds and benzophenone compounds are added in an amount of 0.1 parts by mass to 100 parts by mass of these prepolymers and monomers. About 5 parts by mass can be added. Further, in order to improve the scratch resistance, fine particles having a particle size of 0.1 to 5 μm may be added to the acrylic resin as a filler (filler). The fine particles include inorganic particles made of silica (silicon oxide), alumina (aluminum oxide), calcium carbonate, barium sulfate, etc., and organic particles such as acrylic resin, urethane resin, silicon resin, fluorine resin, melamine resin. Can be used. The addition amount of the fine particles can be about 0.1 to 30% by mass in the acrylic resin layer composition. The thickness of the acrylic resin layers 34a and 34b can be about 1 to 5 μm in a dry and cured state. As ionizing radiation, charged particle beams such as ultraviolet rays, visible rays, electromagnetic waves such as X-rays, electron beams, and alpha rays can be used. In this embodiment, a cured product of an ultraviolet curable acrylic resin composition comprising an acrylate prepolymer, an acrylate monomer, and a benzotriazole photoinitiator is used.

In this embodiment, the dynamic friction characteristics on the surfaces of the acrylic resin layers 34a and 34b are measured under specific conditions using a specific apparatus in a specific vacuum atmosphere as will be described later. The range of the FFM signal value of the substrate is configured to be a specific range. For this purpose, the relationship between the average particle diameter D _AVG and the film thickness t of the acrylic resin layers 34a and 34b is expressed as D _AVG > t for the fine particles added to the acrylic resin.
In addition, the shape of the fine particles, the particle size distribution of the fine particles, the amount of fine particles added in the acrylic resin (the number of fine particles per unit surface area), the dispersion state of the fine particles in the acrylic resin, and the like are appropriately adjusted. .

  The acrylic resin layer 34a may be composed of a plurality of layers. For example, although not shown, the acrylic resin layer 34 a includes a first acrylic resin layer and a second acrylic resin layer provided between the first acrylic resin layer and the transparent substrate 33. You may go out. In this case, preferably, the refractive index of the first acrylic resin layer is in the range of 1.58 to 1.75, and the refractive index of the second acrylic resin layer is 1.50 to 1.60. And the refractive index of the first acrylic resin layer is larger than the refractive index of the second acrylic resin layer. Thereby, the acrylic resin layer 34a can have not only the function as the hard coat layer described above but also the function of adjusting optical characteristics such as transmittance and reflectance. As the material constituting the first acrylic resin layer, a material obtained by dispersing particles or fillers made of a high refractive index material such as niobium oxide or zirconium in a base acrylic resin can be used. Moreover, an acrylic resin etc. may be used as a material which comprises a 2nd acrylic resin layer.

  Similarly, the acrylic resin layer 34b may also be composed of a plurality of layers. For example, although not illustrated, the acrylic resin layer 34 b includes a first acrylic resin layer and a second acrylic resin layer provided between the first acrylic resin layer and the transparent substrate 33. You may go out. In this case, preferably, the refractive index of the first acrylic resin layer is in the range of 1.58 to 1.75, and the refractive index of the second acrylic resin layer is 1.50 to 1.60. And the refractive index of the first acrylic resin layer is larger than the refractive index of the second acrylic resin layer. As a result, as in the case of the acrylic resin layer 34a, the acrylic resin layer 34b has not only the function as the above-mentioned hard coat layer but also the function of adjusting optical characteristics such as transmittance and reflectance. Can do. As a material constituting the first acrylic resin layer and the second acrylic resin layer, the same material as that of the acrylic resin layer 34a can be used.

  When the acrylic resin layers 34a and 34b are composed of a plurality of layers, for example, the acrylic resin layers 34a and 34b are formed of the first acrylic resin layer, the first acrylic resin layer, and the transparent substrate 33. And a second acrylic resin layer provided therebetween, the particle size larger than the thickness of the first acrylic resin layer as a filler (filler) in the acrylic resin of the first acrylic resin layer Fine particles having may be added. Since the fine particles have a particle diameter larger than the thickness of the first acrylic resin layer, the top portion protrudes from the surface of the first acrylic resin layer. Thereby, a minute unevenness | corrugation can be formed in the surface of the film base material 32, and sufficient slipperiness can be provided between the film base material 32 and a guide roller. Therefore, it can suppress that the film base material 32 sticks to a guide roller, and a wrinkle generate | occur | produces in the film base material 32. FIG. Examples of the fine particles include inorganic particles made of silica (silicon oxide), alumina (aluminum oxide), calcium carbonate, barium sulfate, and the like, and organic particles such as acrylic resin, urethane resin, silicon resin, fluorine resin, and melamine resin. Can be used. It is more preferable to use organic particles of styrene acrylic resin because the haze can be reduced by combining the refractive indexes of the fine particles and the acrylic resin.

  In addition, the refractive index shown in this specification means the refractive index with respect to light with a wavelength of 500 nm unless otherwise specified.

  Of the acrylic resin layers 34a and 34b, the acrylic resin layer located on the observer side of the transparent base material 33 is referred to as an “observer side acrylic resin layer”, and the acrylic resin layer located on the opposite side. This may be referred to as “display device side acrylic resin layer”. As will be described later, the conducting wire 51 may be located on the viewer side of the film base material 32 or may be located on the display device side of the film base material 32. Therefore, the acrylic resin layer 34a may be an “observer side acrylic resin layer” and the acrylic resin layer 34b may be a “display device side acrylic resin layer”, or the acrylic resin layer 34b may be an “observer”. In some cases, the acrylic resin layer 34 a becomes a “display side acrylic resin layer”.

  By the way, as mentioned in the column of the problem to be solved by the invention, when a thin film is formed on a film substrate while conveying the film substrate by a roll-to-roll method, the film substrate and the guide roller It is known that when the friction between them is large, wrinkles are generated in the film base material, resulting in a defective shape.

  Therefore, the inventors of the present invention initially have a friction coefficient (hereinafter referred to as a standard atmosphere friction coefficient) measured by a method according to JIS K7125: 1999 in order to suppress the occurrence of wrinkles on the film base. It was considered to use a film substrate within a predetermined range. However, according to actual verification by the present inventors, among the commercially available film base materials having the same standard friction coefficient, wrinkle-generating film base materials, and wrinkle-free film base materials Was found to exist. In other words, it was found that wrinkles could not be sufficiently suppressed by limiting the range of the standard atmospheric friction coefficient.

  As a result of diligent research on such a problem, the inventors of the present invention have the following FFM signal value of the film substrate measured under a specific condition using a specific apparatus in a vacuum atmosphere, It came to know that there is a high correlation between the generation of wrinkles on the film substrate. That is, by limiting the range of the value of the FFM signal of the film base material measured under a specific condition using a specific device in a vacuum atmosphere, the generation of wrinkles on the film base material can be suppressed. It was discovered. This is presumably because the value of the FFM signal corresponds to the coefficient of dynamic friction in the vacuum atmosphere of the film substrate.

  FIG. 5 is a diagram for explaining a method for measuring the displacement of the probe of the friction force microscope to obtain the value of the FFM signal. In the present embodiment, an environmental control type unit AFM5300E having an atomic force microscope (AFM) provided with an atomic force microscope (AFM) is used as the friction force microscope.

  In the example shown in FIG. 5, the frictional force microscope has a probe 81 having a probe 82 at the tip, and a detector 83 that receives light L1 emitted from a light source (not shown) and reflected by the upper surface 81a of the probe 81. doing. The probe 81 is arranged in a cantilever shape having a free end on the side on which the probe 82 is provided. Accordingly, the probe 81 is also called a “cantilever”. In the illustrated example, the detection surface of the detector 83 is divided into two regions, a first region 83a and a second region 83b, which are adjacent in the horizontal direction. In the first region 83a and the second region 83b of the detector 83, photoelectric conversion elements that can convert light such as photodiodes into voltages are arranged. In addition, each area | region 83a, 83b of the detector 83 may be further divided | segmented into 2 areas up and down, and may be divided | segmented into a total of 4 area | regions.

  The probe 81 is moved in the scanning area 85 on each main surface 32a, 32b of the film base 32 along the main surface 32a, 32b in a direction intersecting the longitudinal direction of the probe 81, particularly in a direction orthogonal. In addition, the dynamic frictional force generated between the probe 82 of the probe 81 and the main surfaces 32a and 32b causes the probe 81 to be inclined (displaced) in the torsional direction.

  Light L1 emitted from a light source (not shown) is reflected by the upper surface 81a of the probe 81 and enters the detector 83. The incident position of the light L1 on the detector 83 changes depending on the inclination (displacement) of the upper surface 81a of the probe 81. That is, the incidence ratio of the light L1 to the respective regions 83a and 83b of the detector 83 varies depending on the inclination (displacement) of the upper surface 81a of the probe 81, particularly the inclination (displacement) of the probe 81 in the twisted direction. Therefore, by measuring the voltage difference (signal difference) generated in the photoelectric conversion elements arranged in the regions 83a and 83b by the light L1 incident on the regions 83a and 83b of the detector 83, the displacement of the probe 81, in particular, The inclination (displacement) in the twist direction of the probe 81 can be measured.

  6A to 6C are diagrams illustrating an example of displacement of the probe 81 of the friction force microscope. 6A to 6C, when the probe 81 of the friction force microscope is moved along one main surface 32a of the film base 32 having the pair of main surfaces 32a and 32b along the main surface 32a. An example of the displacement of the probe 81 is shown. 6A to 6C show the probe 81 as seen from the direction along the longitudinal direction thereof.

FIG. 6A shows a state in which the probe 81 is in contact with the main surface 32a of the film base 32 and stopped. In the illustrated example, the upper surface 81a of the probe 81 is parallel to the horizontal direction. The probe 81 is moved along the main surface 32a of the film base 32 in a direction indicated by an arrow that intersects the longitudinal direction of the probe 81 and is parallel to the horizontal direction. In particular, the probe 81 is moved in a direction orthogonal to the longitudinal direction of the probe 81. The movement of the probe 81 along the main surface 32a of the film substrate 32 is performed in a vacuum environment. In the present embodiment, the vacuum specifically refers to a state having a pressure of 3.0 × 10 ⁻³ [Pa].

  When the probe 81 is moved on the main surfaces 32a and 32b of the film base 32 along the main surfaces 32a and 32b, the dynamic friction force generated between the probe 82 of the probe 81 and the main surfaces 32a and 32b. As a result, the probe 81 is inclined (displaced) in the twisted direction. When the dynamic friction coefficient in the vacuum atmosphere of the main surface 32a of the film base 32 is low, the upper surface 81a of the probe 81 is in the horizontal direction (direction parallel to the main surface 32a of the film base 32) as shown in FIG. 6B. The inclination (displacement) is generated with a relatively small angle. On the other hand, when the dynamic friction coefficient in the vacuum atmosphere of the main surface 32a of the film base 32 is high, the upper surface 81a of the probe 81 is in the horizontal direction (the main surface 32a of the film base 32 and the main surface 32a). Inclination (displacement) occurs at a relatively large angle with respect to (parallel direction).

  In the present embodiment, as a signal corresponding to the displacement of the probe 81, the amount of light entering the first region 83a and the second region 83b of the detector 83 corresponding to the lateral displacement of the probe 81 (detection of torsional displacement). A signal (referred to as an FFM signal) that is a difference between signals (voltages) corresponding to is used.

The relationship between the displacement of the probe 81 and the dynamic friction force acting between the probe 82 of the probe 81 and the film substrate 32 will be described. It is known that there is a relationship of the following formula (1) between the FFM signal (FFM) and the minute displacement ΔX of the probe 81.
FFM [mV] = S _FFM [mV / nm] × ΔX [nm] (1)
In the equation, FFM is a voltage value output when a minute displacement ΔX occurs, and S _FFM is a torsional sensitivity, which is a difference in horizontal signal (voltage) of the detector 83 with respect to a torsional displacement of ΔX = 1 nm. Yes, ΔX is a minute displacement of the probe 81.

Note that the frictional force Ft [N] in the minute region is expressed by the following mathematical formula (2).
Ft [N] = Ct [N / m] × ΔX [nm] × 10 ⁻⁹ (2)
In the formula, Ct represents a spring constant of torsion in the probe 81.

From the above formulas (1) and (2), the relationship between the FFM signal and the frictional force Ft [N] in the minute region can be expressed by the following formula (3).
Ft [N] = (Ct [N / m] / S _FFM [mV / nm]) × FFM [mV] × 10 ⁻⁹ (3)

Here, since the spring constant Ct and the torsional sensitivity _SFFM of the probe 81 are inherent constants of the probe 81 and the apparatus, it is clear that the frictional force in the minute region and the FFM signal difference have a proportional relationship. is there. Therefore, the dynamic friction force acting between the probe 82 of the probe 81 and the film substrate 32 can be estimated by accurately estimating the spring constant and the torsional sensitivity and using the FFM signal obtained by the measurement. .

The film substrate 32 of the present embodiment has a pair of main surfaces 32a and 32b, uses an environment control type unit AFM5300E manufactured by Hitachi High-Tech Science Co. as a friction force microscope, and the probe 81 of the friction force microscope is connected to the film. The displacement of the probe 81 when moved along the main surfaces 32a and 32b on the main surfaces 32a and 32b of the base material 32,
Probe model number: SI-DF3-P3
Scanning area: 5.0 [μm] x 2.5 [μm]
Measurement frequency: 0.5 [Hz]
Probe deflection: -0.9977 [nm]
Friction measurement setting load: -0.908 [nN]
Vacuum measurement environment: 3.0 × 10 ⁻³ [Pa]
As a product of the minute displacement ΔX [nm] of the probe 81 and the horizontal signal difference S _FFM [mv / nm] of the detector 83 with respect to the 1 nm torsional displacement of the probe 81 The value of FFM [mv] to be output is 12 [mv] or less.

  Here, the scanning area, measurement frequency (tapping cycle), probe deflection (pushing amount), friction measurement setting load and vacuum measurement environment (vacuum pressure) are all made by Hitachi High-Tech Science Co., Ltd. used as a friction force microscope. A desired value can be set in the control type unit AFM5300E.

  Further, the value of FFM [mv] is 12 [mv] or less means that the probe 81 is placed on the main surface 32a of the film substrate 32 in one direction intersecting the longitudinal direction of the probe 81 in the scanning area 85. The value of FFM [mv] is measured while moving (scanning) along, and the probe 81 is moved (scanning) along the main surface 32a of the film substrate 32 in the other direction intersecting the longitudinal direction of the probe 81. While measuring the value of FFM [mv], the absolute values of all the FFM values measured when the probe 81 was moved in one direction and all the values measured when the probe 81 was moved in the other direction It means that the average value of the absolute values of the FFM values is 12 [mv] or less.

  According to such a film base material 32, since the value of the FFM signal (FFM) corresponding to the dynamic friction coefficient in the vacuum of the film base material 32 is small, it is easy for the surface (main surface) of the film base material 32 in the vacuum. Lubricity can be imparted. Therefore, when the film base material 32 is subjected to some processing while being transported by the roll-to-roll method, the friction between the film base material 32 and the guide roller under reduced pressure such as in a vacuum is reduced. And generation of wrinkles on the film substrate 32 during conveyance can be effectively suppressed. Moreover, since it is not necessary to calculate the dynamic friction coefficient itself in the vacuum of the film base material 32, evaluation of the slipperiness of the surface (main surface) of the film base material 32 can be performed easily and simply.

  In addition, it is preferable that the film base material 32 has heat shrinkability. In the roll-to-roll method, the film substrate 32 is transported in a state where a constant tension is applied in the transport direction (MD direction) so as not to bend between the guide rollers due to the influence of gravity. By applying a certain tension in the transport direction (MD direction) and pulling, a compressive force acts in the width direction (TD direction) of the film substrate. When the film substrate 32 has heat shrinkability, the compressibility in the width direction (TD direction) can be relaxed by heat shrinkage, so that the film substrate 32 is less likely to be wrinkled.

When the film base material 32 has a thermal expansion property, wrinkles are likely to occur in the film base material 32 due to the synergistic effect of the compressive force and the thermal expansion in the width direction (TD direction). Therefore, when the film base material 32 has thermal expansibility, it is preferable that the dimensional change due to heat is small. Specifically, for example, −10 in a direction parallel to the surface and perpendicular to the one direction, measured in a state where a tension of 20 mN / mm ² per unit cross-sectional area is applied in one direction parallel to the surface. When the length at ₀ ° C. is L ₀ and the length at 80 ° C. is L, the dimensional change rate calculated by the formula of (L−L ₀ ) / L ₀ × 100 is 0.25 or less. Is preferred.

  Next, the layer structure of the conducting wire 51 will be described. As shown in FIG. 4, the conducting wire 51 includes a conducting wire forming layer 52 having a low reflection layer 54, a main body layer 53, and a low reflection layer 55 arranged in this order from the film substrate 32 side.

  The main body layer 53 is a layer for mainly realizing electrical conductivity in the conductive wire 51. The main body layer 53 in the present invention is configured to have a thickness of, for example, 0.2 μm or less, more specifically, in a range of 0.02 μm to 0.2 μm. Thereby, it can suppress that the thickness of the conducting wire 51 whole becomes large, and it can suppress that external light and video light are reflected in the side surface of the conducting wire 51 by this. For this reason, the visibility in the display device to which the transparent electrode 31 is attached can be sufficiently ensured.

On the other hand, reducing the thickness of the main body layer 53 can lead to an increase in the electrical resistance value of the conducting wire 51. Here, in the present embodiment, a metal material having a specific resistance equal to or lower than a desired value is used as a material constituting the main body layer 53. For example, the specific resistance is 4.0 × 10 ⁻⁶ (Ωm). The following metal materials are used. Thereby, the electrical resistance value of the conducting wire 51 can be made sufficiently low. For example, the sheet resistance value of the main body layer 53 can be set to 0.3Ω / □ or less. In the present invention, for example, gold, silver, copper, platinum, aluminum, or the like, as a metal material having a specific resistance of 4.0 × 10 ⁻⁶ (Ωm) or less for constituting the main body layer 53, A material (metal simple substance, metal alloy, etc.) containing 90% by weight or more of a metal such as tin can be used. In the present embodiment, a material containing 99% by weight of copper can be used.

  By the way, metal materials, such as copper, show a metallic luster, while having high electroconductivity. For this reason, when an untreated metal material is used as the conducting wire 51, the visibility of the image light from the display device is hindered by the metallic luster of the conducting wire. In particular, copper exhibits a reddish color peculiar to copper, so that it is more conspicuous than other metal materials such as silver, and this hinders the visibility of image light from the display device.

  In order to relieve such a metallic luster peculiar to copper, thin low reflection layers 54 and 55 in which the metallic luster is suppressed as compared with the main body layer 53 are provided on both surfaces of the main body layer 53. Hereinafter, the low reflection layers 54 and 55 will be described.

  The low reflection layers 54 and 55 are layers made of copper nitride. Copper nitride may further contain oxygen atoms. As the copper nitride, for example, a copper compound containing 10 to 15 atomic% nitrogen, 10 to 15 atomic% oxygen, and 70 to 80 atomic% copper may be used. In the low reflection layer 54 configured using such copper nitride, the metallic luster is reduced compared to the metallic luster in the main body layer 53, and in particular, the reddish color peculiar to copper is present. In particular, the reddish color peculiar to copper is reduced. For this reason, it can suppress that the visibility of an image | video falls by the reflected light from the conducting wire 51. FIG.

  The low reflection layers 54 and 55 have a smaller thickness than the main body layer 53. Specifically, the thicknesses of the low reflection layers 54 and 55 are in the range of 10 nm to 60 nm. It is possible to suppress an increase in the thickness of the entire conductive wire 51, and thereby it is possible to suppress external light and video light from being reflected on the side surface of the conductive wire 51.

  Moreover, the reflectance of the light in the conducting wire 51 can also be lowered by setting the thickness of the low reflection layers 54 and 55 within the range of 10 nm to 60 nm. Examples of this reason include, but are not limited to, thin film interference that occurs in the low reflection layers 54 and 55. The thin film interference is a phenomenon in which light reflected on one surface of the low reflection layers 54 and 55 interferes with light reflected on the other surface of the low reflection layers 54 and 55. By setting the thicknesses of the low reflection layers 54 and 55 within the above-mentioned range of 10 to 60 nm, thin film interference occurs so as to weaken the reflected light, and this reduces the light reflectance of the conducting wire 51. Can be considered.

  A method for forming the thin low-reflection layers 54 and 55 as described above is not particularly limited, and a known thin film forming method such as a sputtering method, a vacuum evaporation method, a CVD method, an ion plating method, or an electron beam method is used. Can be used. For example, when a sputtering method is used, a desired composition is obtained by applying discharge power to a target made of copper while supplying both nitrogen gas or nitrogen gas and oxygen gas controlled to a predetermined flow rate in a vacuum atmosphere. It is possible to obtain a layer made of the above-mentioned copper nitride having

  Next, a method for manufacturing the transparent electrode 31 having the above configuration will be described with reference to FIGS. 7A to 7E.

  First, as shown to FIG. 7A, the film base material 32 is prepared. As described above, the film base 32 includes the transparent base 33 and the acrylic resin layers 34 a and 34 b provided on both sides of the transparent base 33.

  An example of a method for producing the film substrate 32 will be described. First, a long transparent substrate 33 is prepared, and acrylic resin layers 34 a and 34 b are formed on both sides of the transparent substrate 33. For example, the acrylic resin layers 34a and 34b can be formed by coating a coating liquid containing an acrylic resin on the transparent substrate 33 using a coater. At this time, as the coater, a coater that can sufficiently ensure the flatness of the acrylic resin layers 34a and 34b is preferably used. For example, a gravure coater is used. The coating liquid for forming the acrylic resin layers 34a and 34b may contain a leveling agent for improving the flatness of the acrylic resin layers 34a and 34b. Thereby, for example, it is possible to suppress the occurrence of defects such as pinholes when the conductive wire 51 layer is formed on the acrylic resin layer 34a.

After the film base material 32 is prepared, the low reflection layer 54 is formed on the acrylic resin layer 34a as shown in FIG. 7B while transporting the film base material 32 by a roll-to-roll method. The low reflective layer 54 uses, for example, AC discharge with a frequency of 30 kHz to 2 MHz (hereinafter, also referred to as AC discharge of a specific frequency or AC discharge) in a vacuum atmosphere containing nitrogen gas and a pressure of 10 ⁻¹ Pa. It can be formed by sputtering a copper target. A copper target may be sputtered using an AC discharge and a DC discharge (hereinafter also referred to as DC discharge) having a frequency of 30 kHz to 2 MHz in combination. In addition to nitrogen gas, oxygen gas may be further introduced.

  Next, as shown in FIG. 7B, the main body layer 53 is formed on the low reflection layer 54. Then, the low reflection layer 55 is formed on the main body layer 53. As a method for forming the main body layer 53 and the low reflection layer 55, as described above, a thin film forming method such as a sputtering method can be used.

  In this way, a laminate 60 (also referred to as a blank) as a base material for producing the transparent electrode 31 is obtained. The laminated body 60 includes a film base material 32 and a conductive wire forming layer 52 provided on the film base material 32. The conductive wire forming layer 52 includes a low reflection layer 54, a main body layer 53, and a low reflection layer 55 arranged in this order from the film base material 32 side.

  After the laminated body 60 is prepared, as shown in FIG. 7C, a photosensitive resist layer 71 is formed on the conductive wire forming layer 52 in a predetermined pattern. The photosensitive resist layer 71 has photosensitivity to light in a specific wavelength range, for example, ultraviolet rays. The type of the photosensitive resist layer 71 is not particularly limited. For example, a photodissolvable photosensitive resist layer may be used, or a photocurable photosensitive resist layer may be used. Here, an example in which a photodissolvable photosensitive resist layer is used will be described.

  The photosensitive resist layer 71 is formed in a pattern corresponding to the pattern of the conductive wire 51. The photosensitive resist layer 71 is, for example, by first coating a photosensitive resist material on the surface of the laminate 60 using a coater, and then exposing and developing the photosensitive resist material in a predetermined pattern. A photosensitive resist layer 71 having a predetermined pattern shape is formed.

  Next, as shown in FIG. 7D, the low reflection layer 55, the main body layer 53, and the low reflection layer 54 are etched using the photosensitive resist layer 71 as a mask. As described above, all of the low reflection layer 55, the main body layer 53, and the low reflection layer 54 are configured to include copper. For this reason, the low reflection layer 55, the main body layer 53, and the low reflection layer 54 can be etched simultaneously using an etching solution capable of dissolving copper. For example, an aqueous ferric chloride solution is used as the etching solution.

  Next, the photosensitive resist layer 71 remaining on the main body layer 53 is washed with a chemical solution for dissolving and removing the photosensitive resist layer 71 and subjected to film removal. Thereby, as shown in FIG. 7E, the photosensitive resist layer 71 can be removed. In this way, the conductive wire forming layer 52 having the low reflective layer 55, the main body layer 53, and the low reflective layer 54 is patterned, and the transparent electrode 31 including the conductive wire 51 configured therefrom can be obtained.

  Here, according to the present embodiment, as described above, the conductive wire 51 includes the main body layer 53 containing 90% by weight or more of copper, and the low reflection layer 54 made of copper nitride provided on the surface of the main body layer 53. And. For this reason, the low reflection layer 54 can suppress reddish light from reaching the observer due to the metallic luster of copper. Moreover, since both the main body layer 53 and the low reflection layers 54 and 55 contain copper, when producing the transparent electrode 31 from the laminated body 60, by using an etching solution capable of selectively dissolving copper. The conductor layer 51 can be formed by simultaneously etching the main body layer 53 and the low reflection layers 54 and 55 of the laminate 60. For this reason, the man-hour required in order to produce the transparent electrode 31 can be made small.

The film substrate 32 of the present embodiment has a pair of main surfaces 32a and 32b, uses an environment control type unit AFM5300E manufactured by Hitachi High-Tech Science Co. as a friction force microscope, and the probe 81 of the friction force microscope is connected to the film. The displacement of the probe 81 when moved along the main surfaces 32a and 32b on the main surfaces 32a and 32b of the base material 32,
Probe model number: SI-DF3-P3
Scanning area: 5.0 [μm] x 2.5 [μm]
Measurement frequency: 0.5 [Hz]
Probe deflection: -0.9977 [nm]
Friction measurement setting load: -0.908 [nN]
Vacuum measurement environment: 3.0 × 10 ⁻³ [Pa]
As a product of the minute displacement ΔX [nm] of the probe 81 and the horizontal signal difference S _FFM [mv / nm] of the detector 83 with respect to the 1 nm torsional displacement of the probe 81 The value of FFM [mv] to be output is 12 [mv] or less.

  According to such a film base material 32, since the value of the FFM signal (FFM) corresponding to the dynamic friction coefficient in the vacuum of the film base material 32 is small, it is easy for the surface (main surface) of the film base material 32 in the vacuum. Lubricity can be imparted. Therefore, when the film base material 32 is subjected to some processing while being transported by the roll-to-roll method, the friction between the film base material 32 and the guide roller under reduced pressure such as in a vacuum is reduced. And generation of wrinkles on the film substrate 32 during conveyance can be effectively suppressed. Moreover, since it is not necessary to calculate the dynamic friction coefficient itself in the vacuum of the film base material 32, evaluation of the slipperiness of the surface (main surface) of the film base material 32 can be performed easily and simply.

<Second Embodiment>
Next, a second embodiment of the present invention will be described with reference to FIGS. In the present embodiment, a display device with a touch position detection function obtained by combining a touch panel including the above-described transparent electrode 31 and a display device will be described. In the present embodiment, the same parts as those in the above-described embodiments are denoted by the same reference numerals, and detailed description thereof is omitted. In addition, when it is clear that the operational effects obtained in each embodiment can be obtained also in this embodiment, the description thereof may be omitted.

  FIG. 8 is a development view showing the display device 10 with a touch position detection function. As shown in FIG. 8, the display device 10 with a touch position detection function is configured by combining a touch panel 30 and a display device 15 such as a liquid crystal display or an organic EL display.

  The illustrated display device 15 is configured as a flat panel display. The display device 15 includes a display panel 16 having a display surface 16 a and a display control unit (not shown) connected to the display panel 16. The display panel 16 includes an active area A1 that can display an image, and an inactive area (also referred to as a frame area) A2 that is disposed outside the active area A1 so as to surround the active area A1. . The display control unit processes information regarding the video to be displayed, and drives the display panel 16 based on the video information. The display panel 16 displays a predetermined image on the display surface 16a based on a control signal from the display control unit. That is, the display device 15 plays a role as an output device that outputs information such as characters and drawings as video.

  As shown in FIG. 8, a protective plate 12 having translucency may be further provided on the viewer side of the touch panel 30, that is, the side opposite to the display device 15. For example, the protective plate 12 is bonded to the surface of the touch panel 30 on the viewer side with an adhesive layer or the like. The protective plate 12 is for preventing damage to the pattern of the touch panel 30 and the display device 15 due to contact with an external conductor such as a finger, and is also referred to as a so-called front plate.

  As shown in FIG. 8, the touch panel 30 is bonded to the display surface 16a of the display device 15 via, for example, an adhesive layer (not shown). The touch panel 30 is configured by combining two transparent electrodes 31. In FIG. 8, the see-through electrode arranged on the viewer side is represented by reference numeral 31A, and the see-through electrode arranged on the display device side from the see-through electrode 31A is represented by reference numeral 31B. In the following description, the transparent electrode labeled 31A is also referred to as a first transparent electrode 31A, and the transparent electrode labeled 31B is also referred to as a second transparent electrode 31B.

  FIG. 9 is a plan view showing the touch panel 30 when viewed from the observer side. In FIG. 9, the constituent elements of the first transparent electrode 31A are represented by solid lines, and the constituent elements of the second transparent electrode 31B are represented by dotted lines.

  As shown in FIG. 9, each of the first transparent electrode 31A and the second transparent electrode 31B includes a plurality of conductive patterns 41 extending in a predetermined direction. Here, the first transparent electrode 31A and the second transparent electrode 31B are arranged so that the respective conductive patterns 41 extend in directions intersecting each other. For example, the first transparent electrode 31A is arranged such that the conductive pattern 41 extends along the first direction D1. On the other hand, the 2nd transparent electrode 31B is arrange | positioned so that the conductive pattern 41 may extend along the 2nd direction D2 orthogonal to the 1st direction D1.

  FIG. 10 is an enlarged plan view showing the conductive pattern 41 in the portion surrounded by the alternate long and short dash line with the symbol X in FIG. As shown in FIG. 10, the conductive pattern 41 of the first transparent electrode 31 </ b> A and the conductive pattern 41 of the second transparent electrode 31 </ b> B are each composed of conductive wires 51 arranged in a mesh shape.

  11 is a cross-sectional view showing a case where the touch panel 30 is cut along the line XI-XI in FIG. As shown in FIG. 11, the touch panel 30 has a first perspective view so that both the lead wire 51 of the first transparent electrode 31 </ b> A and the lead wire 51 of the second transparent electrode 31 </ b> B are located on the display device side of the film base 32. 31A and the second transparent electrode 31B are combined. Note that an adhesive layer 38 or the like may be interposed between the first transparent electrode 31A and the second transparent electrode 31B.

  12 is an enlarged cross-sectional view of a part of the touch panel 30 shown in FIG. As shown in FIG. 12, both the conductive wire 51 of the first transparent electrode 31 </ b> A and the conductive wire 51 of the second transparent electrode 31 </ b> B include the above-described conductive wire forming layer 52. Here, as shown in FIG. 12, the conductor forming layer 52 includes a main body layer 53, a low reflection layer 54 provided on the viewer side of the main body layer 53, and a low reflection provided on the display device side of the main body layer 53. Layer 55.

  Since the low reflection layer 54 is provided on the viewer side of the main body layer 53, it is possible to prevent external light incident on the touch panel 30 from the viewer side from being reflected by the conductive wire 51 and returning to the viewer side. it can. Thereby, it can suppress that the conducting wire 51 is visually recognized by an observer, and this can suppress that the visibility of the image from the display device 15 is hindered by the conducting wire 51. Further, since the low reflection layer 55 is provided on the display device side of the main body layer 53, the image light from the display device 15 incident on the touch panel 30 is reflected by the conductive wire 51 and returns to the display device 15 side, and then the display is performed. It can be suppressed that the light is reflected again by the components of the device 15 and reaches the observer as noise light.

  Further, as described above, the main body layer 53 of the conductive wire forming layer 52 is configured to have a thickness of 0.2 μm or less. In the present embodiment, it is 0.1 μm. For this reason, it can suppress that the light which injected into the touch panel 30 along the direction inclined from the normal line direction of the film base material 32 is reflected by the side surface of the conducting wire formation layer 52. Thereby, it can suppress that the side of the conducting wire 51 is visually recognized by an observer, and that the video light from the display device is hindered by the side of the conducting wire 51. Accordingly, the visibility of the video can be improved.

  Various changes can be made to the above-described embodiment. Hereinafter, modified examples will be described with reference to the drawings. 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 the above embodiment. The duplicated explanation is omitted. In addition, when it is clear that the operational effects obtained in the above-described embodiment can be obtained in the modified example, the description thereof may be omitted.

  FIG. 11 shows an example in which both the conductive wire 51 of the first transparent electrode 31A and the conductive wire 51 of the second transparent electrode 31B are located on the display device side of the film substrate 32, but the present invention is limited to this. There is no. For example, as shown in FIG. 13, the conducting wire 51 of the first transparent electrode 31A is located on the viewer side of the film substrate 32, while the conducting wire 51 of the second transparent electrode 31B is an indication of the film substrate 32. It may be located on the device side.

  As shown in FIG. 14, the conducting wire 51 of the first transparent electrode 31 </ b> A is located on the display device side of the film substrate 32, while the conducting wire 51 of the second transparent electrode 31 </ b> B is an observation of the film substrate 32. It may be located on the person side.

  Next, a preferred example of the cross-sectional shape of the conducting wire 51 when the conducting wire 51 is provided on the display device side of the film base material 32 will be described with reference to FIG.

  As shown in FIG. 15, the conductive wire forming layer 52 of the conductive wire 51 has a tapered shape that tapers toward the display device 15. In this case, the external light L2 incident on the touch panel 30 along the direction inclined from the normal direction of the film base material 32 is not incident on the side surface of the conductor 51 due to the tapered shape of the conductor formation layer 52. You can escape to the side. For this reason, it can further suppress that external light is reflected by the conducting wire 51 and returns to the observer side.

  Although the specific taper shape of the conducting wire forming layer 52 is appropriately set according to the assumed degree of inclination of external light, for example, the normal direction of the film substrate 32 and the side surface of the conducting wire 51 are formed. The angle is in the range of 10 ° to 30 °.

  In addition, although the some modification with respect to this Embodiment mentioned above has been demonstrated, naturally, it can also apply combining a some modification suitably.

<Third Embodiment>
Next, a third embodiment of the present invention will be described with reference to FIGS. In the present embodiment, an example in which the conductive wires 51 are provided on both sides of the film substrate 32 will be described. In the present embodiment, the same parts as those in the above-described embodiments are denoted by the same reference numerals, and detailed description thereof is omitted. In addition, when it is clear that the operational effects obtained in each embodiment can be obtained also in this embodiment, the description thereof may be omitted.

  As shown in FIG. 16, the transparent electrode 31 includes a film base 32, a conductor 51 provided on an observer-side surface (first surface, main surface) 32 a of the film base 32, and a film base. And a conductive wire 51 provided on a display device side surface (second surface, main surface) 32b. The conductive pattern 41 made of the conductive wire 51 on the first surface 32a side and the conductive pattern 41 made of the conductive wire 51 on the second surface 32b side are provided so as to cross each other. For example, in the figure, the conductive pattern 41 on the first surface 32a extends in a direction orthogonal to the paper surface, and the conductive pattern 41 on the second surface 32b extends in a direction parallel to the paper surface. For this reason, according to the present embodiment, the touch panel 30 can be configured by the single transparent electrode 31.

  FIG. 17 is an enlarged cross-sectional view of a part of the transparent electrode 31 shown in FIG. As shown in FIG. 17, the conductive wires 51 provided on the first surface 32 a and the second surface 32 b of the film base 32 each include the above-described conductive wire forming layer 52. For this reason, it can suppress that the external light which injected into the touch panel 30 from the observer side is reflected by the conducting wire 51, and returns to the observer side. Thereby, it can suppress that the conducting wire 51 is visually recognized by an observer, and this can suppress that the visibility of the image from the display device 15 is hindered by the conducting wire 51.

  In addition, although the some modification with respect to this Embodiment mentioned above has been demonstrated, naturally, it can also apply combining a some modification suitably.

  In each of the above-described embodiments, the dynamic friction characteristics on the surfaces of the acrylic resin layers 34a and 34b were measured under specific conditions using a specific apparatus in a specific vacuum atmosphere. The range of the value of the FFM signal is configured to be a specific range.

  However, the present invention is not limited to this. In addition to such a configuration, the surface of the film base 32 itself, that is, the first surface 32a and the second surface 32b, can be formed with a specific dynamic friction characteristic in a specific vacuum atmosphere without forming the acrylic resin layers 34a and 34b. You may comprise so that the range of the value of the FFM signal of the film base material 32 measured on specific conditions using the apparatus may become a specific range. For that purpose, fine particles are added to the film base material 32 in the same manner as the acrylic resin layers 34a and 34b, or the dynamic friction characteristic is specified on the surface of the film base material 32 in a specific vacuum atmosphere. A fine uneven shape is shaped (embossed) so that the range of the value of the FFM signal of the film substrate 32 measured under a specific condition using an apparatus falls within the specific range.

  In each of the embodiments described above, the use of the transparent electrode 31 has been described using the touch position detection electrode of the touch panel as an example. However, the use of the transparent electrode 31 of the present invention is not limited to this. In addition to touch position detection electrodes, transparent electrodes of EL (electroluminescence) image display devices, screens of various image display devices, windows of buildings, transparent electromagnetic shielding materials to be mounted on vehicle windows, windows of buildings, It can also be used for applications such as a transparent heating electrode mounted on a vehicle window or the like for defrosting or defogging.

  EXAMPLES Next, although an Example demonstrates this invention further more concretely, this invention is not limited to description of a following example, unless the summary is exceeded.

  As shown to FIG. 7A, the film base material 32 containing the transparent base material 33 and the acrylic resin layers 34a and 34b provided in both surfaces of the transparent base material 33 was prepared. In this example, five types of film base materials 32 were prepared as samples. As a material constituting the transparent base material 33 of the film base material 32, a biaxially stretched PET film having a thickness of 100 μm was used. Materials constituting the acrylic resin layers 34a and 34b of the film substrate 32 include a monomer having an acryloyl group in the molecule, a prepolymer having an acryloyl group in the molecule, and a benzotriazole photoinitiator to ultraviolet rays. A curable acrylic resin obtained by crosslinking and curing by ultraviolet irradiation was used.

For each sample, the value of the FFM signal was measured. Using the environment control type unit AFM5300E manufactured by Hitachi High-Tech Science Co., Ltd. as the friction force microscope, the displacement of the probe of the friction force microscope is measured under the following conditions, and the detection of the probe's minute displacement ΔX [nm] and the 1 nm torsional displacement of the probe The value of FFM [mv] output as the product of the horizontal signal difference S _FFM [mv / nm] of the device was obtained.
Probe model number: SI-DF3-P3
Scanning area: 5.0 [μm] x 2.5 [μm]
Measurement frequency (tapping cycle): 0.5 [Hz]
Probe deflection (pushing amount): -0.9977 [nm]
Friction measurement setting load: -0.908 [nN]
Vacuum measurement environment (vacuum pressure): 3.0 × 10 ⁻³ [Pa]

Then, each sample was conveyed through the guide roller in vacuum (3.0 × 10 ⁻³ [Pa]), and the presence or absence of wrinkles after the conveyance was visually observed.

  Table 1 shows a summary of the thickness of the acrylic resin layer [μm], the material and particle size of the fine particles contained in the acrylic resin layer [μm], FFM [mv], and the presence or absence of wrinkles for each sample. . Moreover, what represented the value of FFM [mv] of each sample with the bar graph is shown in FIG. Here, samples whose FFM [mv] value is 12 [mv] or less are samples 1 to 3 in order from the smallest FFM [mv] value, and the FFM [mv] value is larger than 12 [mv]. The samples were designated as Comparative Samples 1 and 2 in order from the smallest FFM [mv] value.

  As shown in Table 1, Samples 1 to 3 having an FFM [mv] value of 12 [mv] or less had a good film shape with no visible wrinkles even after conveyance in vacuum. In Comparative Samples 1 and 2, in which the value of FFM [mv] was larger than 12 [mv], wrinkles were visually observed after conveyance in vacuum.

  Thereby, the displacement of the probe of the friction force microscope is measured under the above-described conditions using the environment control type unit AFM5300E manufactured by Hitachi High-Tech Science Co. as the friction force microscope as the film base material 32, and the value of FFM [mv] acquired. By using the film base 32 having a thickness of 12 [mv] or less, when the film base 32 is conveyed through a guide roller in a vacuum, the film base 32 is effectively prevented from being wrinkled. It was confirmed that it can be suppressed. Therefore, when the film substrate is conveyed while being in contact with the guide roller under reduced pressure, such as when film formation is performed under reduced pressure, the film substrate is used from the viewpoint of suppressing the generation of wrinkles on the film substrate during conveyance. It can be said that it is extremely effective to use a film base material having an FFM [mv] value of 12 [mv] or less as a material.

DESCRIPTION OF SYMBOLS 10 Display apparatus with a touch position detection function 12 Protection board 15 Display apparatus 16 Display panel 30 Touch panel 31 Transparent electrode 32 Film base material 32a, 32b Main surface 33 Transparent base material 34a, 34b Acrylic resin layer 38 Adhesive layer 41 Conductive pattern 43 Frame wiring 44 Terminal portion 51 Conductive wire 52 Conductive wire forming layer 53 Main body layer 54 Low reflective layer 55 Low reflective layer 60 Laminate 71 Photosensitive resist layer 81 Probe 82 Probe 83 Detector 85 Scanning area

Claims (4)

A film substrate having a pair of main surfaces,
Displacement of the probe when the probe of the friction force microscope is moved on each main surface of the film base along the main surface using an environment control type unit AFM5300E manufactured by Hitachi High-Tech Science Co. as a friction force microscope. The
Probe model number: SI-DF3-P3
Scanning area: 5.0 [μm] x 2.5 [μm]
Measurement frequency: 0.5 [Hz]
Probe deflection: -0.9977 [nm]
Friction measurement setting load: -0.908 [nN]
Vacuum measurement environment: 3.0 × 10 ⁻³ [Pa]
_Is output as the product of the minute displacement ΔX [nm] of the probe and the signal difference S _FFM [mv / nm] in the horizontal direction of the detector with respect to the torsional displacement of 1 nm of the probe. The film base material whose value of FFM [mv] is 12 [mv] or less. A film substrate according to claim 1;
A plurality of conductive patterns provided on the film substrate;
With
The conductive pattern is a transparent electrode which is a conductive wire having a light shielding property and is configured by conductive wires arranged in a mesh shape so that an opening is formed between the conductive wires.   A touch panel comprising the transparent electrode according to claim 2. A display device;
The touch panel according to claim 3, which is disposed on a display surface of the display device,
A display device with a touch position detection function.

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