WO2015012199A1 - Touch panel and conductive film - Google Patents

Abstract

The present invention provides a touch panel whereby occurrence of iridescence is reduced, and which is not prone to location detection precision degradation even after high-temperature high-humidity processing. This touch panel comprises an image display panel which emits linearly polarized light, and a touch panel sensor which is positioned on a viewable side of the image display panel. The touch panel sensor further comprises at least a substrate which exhibits optical anisotropy. The substrate satisfies the relation of the formula (1) and is positioned such that the oscillation direction of the linearly polarized light which is emitted from the image display panel and the planar slow axis of the substrate are either orthogonal or parallel, and the maximum index of refraction (nx) in the plane of the substrate is 1.60 or greater. Formula (1): Nz > 3.0

Description

Touch panel, conductive film

The present invention relates to a touch panel, and in particular, a substrate showing optical anisotropy contained in a touch panel sensor exhibits a predetermined Nz coefficient and nx, and an in-plane slow axis of the substrate and a straight line emitted from an image display panel. The present invention relates to a touch panel in which a polarization vibration direction has a predetermined relationship.
Moreover, this invention relates also to the electroconductive film used for the said touch panel.

In recent years, the mounting rate of touch panels on mobile phones, portable game devices, and the like has increased, and for example, capacitive touch panels capable of multipoint detection have attracted attention.
Especially, the aspect which uses the transparent conductive film which shows a predetermined Nz coefficient for the purpose of the visibility improvement of a touch panel is disclosed (patent document 1). More specifically, when a transparent conductive film having a transparent conductive layer on at least one surface of a flexible transparent substrate and having an Nz coefficient satisfying the following relationship (ii) is used, rainbow unevenness is generated. It is disclosed that it can be suppressed.
(Ii) 0.8 ≦ Nz ≦ 1.4
In paragraph [0057] of Patent Document 1, in order for Nz of the entire transparent conductive film to satisfy the above relationship (ii), it is necessary and sufficient that the flexible transparent substrate satisfies the above (ii). Is described.
Moreover, as described in Patent Document 1, it is preferred that a flexible transparent substrate is a substrate such as PET that has been subjected to stretching / crystallization treatment because of its excellent mechanical properties. These substrates have a large birefringence in the plane and in the thickness direction. That is, the flexible transparent substrate exhibits optical anisotropy.

JP 2012-230491 A

In recent years, in order to meet the demand for a larger touch panel screen, it is required to perform position detection with higher accuracy. On the other hand, the touch panel is used in a warm environment such as high temperature and high humidity, and may be exposed to high temperature and high humidity for accelerated device reliability testing. High position detection accuracy (touch position detection accuracy) is required. Furthermore, from the viewpoint of improving the visibility of the touch panel, it is also required to reduce the occurrence of rainbow unevenness.
When the inventors produce a touch panel using a transparent conductive film having a predetermined Nz coefficient described in Patent Document 1 and leave it in a high-temperature and high-humidity environment, the occurrence of rainbow unevenness is reduced. However, it has been found that there is a problem that the position detection accuracy deteriorates.

In view of the above circumstances, an object of the present invention is to provide a touch panel in which the occurrence of rainbow unevenness is reduced and the position detection accuracy is hardly deteriorated even after high-temperature and high-humidity processing.

As a result of intensive studies on the above problems, the inventors of the present invention use a touch panel sensor including a substrate exhibiting a predetermined Nz coefficient and nx, and the in-plane slow axis of the substrate and linearly polarized light emitted from the image display panel. It has been found that the above problem can be solved by making the arrangement with the vibration direction a predetermined relationship. That is, it has been found that the above object can be achieved by the following configuration.

(1) A touch panel having an image display panel that emits linearly polarized light, and a touch panel sensor disposed on a viewing side of the image display panel,
The touch panel sensor includes at least a substrate exhibiting optical anisotropy,
The substrate satisfies the relationship of formula (1) described later,
The vibration direction of the linearly polarized light emitted from the image display panel and the in-plane slow axis of the substrate are arranged so as to be orthogonal or parallel,
A touch panel having a maximum refractive index nx in the substrate plane of 1.60 or more.
(2) The touch panel according to (1), wherein nx is 1.61 to 1.70.
(3) The touch panel according to (1) or (2), wherein Re (550), which is a retardation value of the substrate measured at a wavelength of 550 nm, is 1000 to 3500 nm.
(4) The touch panel according to any one of (1) to (3), wherein the substrate includes polyethylene terephthalate.
(5) The touch panel according to any one of (1) to (4), wherein the detection electrode included in the touch panel sensor has a mesh pattern including a plurality of conductive thin wires that intersect.
(6) The touch panel according to (5), wherein the conductive thin wire includes at least one selected from the group consisting of gold, silver, and copper.
(7) A conductive film disposed on the viewing side of the image display panel that emits linearly polarized light,
A substrate having optical anisotropy, and a conductive portion on at least one surface of the substrate,
The substrate satisfies the relationship of formula (1) described later,
The electroconductive film whose maximum refractive index nx in a substrate surface is 1.60 or more.

According to the present invention, it is possible to provide a touch panel in which occurrence of rainbow unevenness is reduced and position detection accuracy is hardly deteriorated even after high-temperature and high-humidity treatment.

It is sectional drawing of embodiment of the touchscreen of this invention. It is sectional drawing of other embodiment of the touchscreen of this invention. It is a top view which shows one Embodiment of a touchscreen sensor. FIG. 4 is a cross-sectional view taken along a cutting line AA shown in FIG. It is an enlarged plan view of a 1st detection electrode. It is a partial cross section of 2nd Embodiment of a touch panel sensor. It is a partial cross section of 3rd Embodiment of a touchscreen sensor. It is the schematic which shows the relationship between a polar angle and an azimuth.

Hereinafter, the present invention will be described in detail. In the present specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value. First, terms used in this specification will be described.
Re (λ) represents in-plane retardation at the wavelength λ, respectively. Re (λ) is measured with KOBRA 21ADH or WR (manufactured by Oji Scientific Instruments Co., Ltd.) by making light having a wavelength of λ nm incident in the normal direction of the film. In selecting the measurement wavelength λnm, the wavelength selection filter can be exchanged manually, or the measurement value can be converted by a program or the like. Details of the method for measuring Re (λ) are described in paragraphs 0010 to 0012 of JP2013-041213A, the contents of which are incorporated herein by reference.

In addition, in this specification, when there is no special mention about a measurement wavelength, a measurement wavelength is 550 nm.
In this specification, an angle (for example, an angle such as “90 °”) and a relationship thereof (for example, “orthogonal (right angle)”, “parallel”, etc.) are errors allowed in the technical field to which the present invention belongs. The range of At this time, the allowable error means, for example, that the angle is within a range of a strict angle ± 5 ° or less, and the error from the strict angle is preferably 3 ° or less. More specifically, orthogonal (right angle) is intended to be within the range of 90 ° ± 5 °, and parallel is intended to be within the range of 0 ° ± 5 °.

Below, the suitable aspect of the touchscreen of this invention (henceforth only a touchscreen) is demonstrated with reference to drawings.
As described above, the touch panel of the present invention is characterized by using a touch panel sensor including a substrate showing a predetermined Nz coefficient (also simply referred to as Nz) and nx, as well as an in-plane slow axis and image of the substrate. For example, the arrangement of the linearly polarized light emitted from the display panel and the vibration direction may have a predetermined relationship. The inventors of the present invention are flexible and transparent as a cause of the deterioration of position detection accuracy when a high-temperature and high-humidity treatment is performed on a touch panel manufactured using the transparent conductive film described in Patent Document 1. It was found that the deformation of the substrate contributed greatly. That is, since the flexible transparent substrate is deformed, it has been found that the position of the transparent conductive layer functioning as the detection electrode is displaced, and as a result, the position detection accuracy is likely to deteriorate. Hereinafter, the cause of the problem in the prior art will be described in more detail.
As a result of intensive studies on the problems of the prior art, the present inventors have found that the refractive index and heat shrinkability show a certain relationship. That is, it has been found that when the substrate exhibits a high refractive index in a predetermined direction, the heat shrinkability in that direction becomes small. In other words, when the substrate exhibits a low refractive index in a predetermined direction, it corresponds to an increase in heat shrinkability in that direction.
The transparent conductive film used in Patent Document 1 shows 0.8 ≦ Nz ≦ 1.4, and Nz is relatively small. In consideration of the point that Nz is “formula (X): Nz = (nx−nz) / (nx−ny)”, in order for Nz to be small, the denominator (nx−ny) in formula (X) Is large, in other words, the difference between nx and ny needs to be large. That is, the difference (refractive index difference) between nx and ny is required to be large. If it does so, it will become small as a value of ny and, as a result, the heat shrinkability in the direction will become large. In other words, if Nz is small, the heat shrinkability in the ny direction becomes relatively large, and the position of the detection electrode included in the touch panel sensor is greatly displaced due to the heat shrinkage of the substrate, resulting in degradation of position detection accuracy. It becomes easy.
On the other hand, in the present invention, the Nz of the substrate used is large. When Nz is large, the denominator (nx−ny) in formula (X) is small, in other words, the difference between nx and ny is small. Also, the molecule (nx-nz) in formula (X) is required to be large, and nx itself is relatively large. Then, since the value of ny approximates nx, the refractive index in the ny direction is large. In other words, since the heat shrinkability in that direction (y direction) is reduced, the detection electrode is less likely to be misaligned, and as a result, the position detection accuracy is less likely to deteriorate.
In the present invention, the rainbow unevenness is less likely to occur because the arrangement of the in-plane slow axis of the substrate and the vibration direction of the linearly polarized light emitted from the image display panel satisfies a predetermined relationship. In this specification, the observation of rainbow unevenness is when the touch panel is observed while changing the azimuth angle from the direction orthogonal or the same as the vibration direction of the linearly polarized light emitted from the image display panel (in particular, When observing at an azimuth angle of 30 to 60 °), it is intended to observe whether or not rainbow unevenness is suppressed.

FIG. 1 is a cross-sectional view of the touch panel of the present invention. In addition, the figure in this invention is a schematic diagram, and the relationship of the thickness of each layer, a positional relationship, etc. do not necessarily correspond with an actual thing.
As shown in FIG. 1, the touch panel 1 includes an image display panel 2 and a touch panel sensor 3, and the image display panel 2 emits linearly polarized light toward the viewing side. In addition, in FIG. 1, it visually recognizes from the direction of an arrow. The image display panel 2 includes at least an image display cell 4 and a polarizing plate 5 on the viewing side.
In the case where the touch panel 1 is a capacitive touch panel, when a finger approaches or touches the touch panel sensor 3, the capacitance between the finger and the detection electrode in the touch panel sensor 3 changes. Here, a position detection driver (not shown) always detects a change in capacitance between the finger and the detection electrode. When the position detection driver detects a change in capacitance that is equal to or greater than a predetermined value, the position detection driver detects a position where the change in capacitance is detected as an input position. In this way, the touch panel 1 can detect the input position.
Hereinafter, each member of the touch panel 1 will be described in detail. First, the image display panel 2 will be described.

[Image display panel]
The image display panel 2 includes an image display cell 4 and a polarizing plate 5 (viewing-side polarizing plate) on the viewing side.
As the image display cell 4, a liquid crystal cell, an organic EL cell, or the like is used.
Liquid crystal cells include reflective liquid crystal cells that use external light, transmissive liquid crystal cells that use light from a light source such as a backlight, and semi-transmissive and semi-reflective types that use both external light and light from the light source. Any liquid crystal cell may be used. In addition, as a driving method of the liquid crystal cell, for example, any type such as a VA mode, an IPS mode, a TN mode, an STN mode, or a bend alignment (π type) can be used. When a transmissive liquid crystal cell or a transflective liquid crystal cell is adopted as the liquid crystal cell, the image display panel includes a light source side polarizing plate on the side opposite to the viewing side of the liquid crystal cell, and further includes a light source. It may be. In this case, the light emitted from the light source is converted in its polarization state while propagating through the liquid crystal cell, and the amount of transmitted light is absorbed by the polarizing plate disposed on the viewing side of the liquid crystal cell. Has been adjusted to enable image display. Therefore, the light emitted from the image display panel to the viewing side is linearly polarized light having a vibration surface in the transmission axis direction of the polarizing plate 5.

As the organic EL cell, for example, a light emitting body (organic electroluminescent light emitting body) in which a transparent electrode, an organic light emitting layer, and a metal electrode are sequentially laminated on a transparent substrate is used. The organic light emitting layer is a laminate of various organic thin films, for example, a laminate of a hole injection layer made of a triphenylamine derivative or the like and a light emitting layer made of a fluorescent organic solid such as anthracene, or the like Structures having various combinations such as a laminate of an electron injection layer composed of a light emitting layer and a perylene derivative, or a laminate of these hole injection layer, light emitting layer, and electron injection layer are known. Since the organic EL panel enables image display by adjusting the light emission amount of the organic EL cell itself, a polarizing plate is not essential for image display. However, since the thickness of the organic light emitting layer is very thin, external light is reflected by the metal electrode and emitted again to the viewing side, and when viewed from the outside, the display surface of the organic EL display device may appear as a mirror surface. is there. In order to shield such specular reflection of external light, a circularly polarizing plate 8 in which a polarizing plate 5 and a quarter-wave plate 7 are laminated is arranged on the viewing side of the organic EL cell 6 as shown in FIG. The method is adopted. Therefore, the light emitted from the organic EL panel 9 including the circularly polarizing plate 8 on the viewing side to the viewing side is linearly polarized light having a vibration surface in the transmission axis direction of the polarizing plate 5 constituting the circularly polarizing plate 8.
As described above, the light emitted from the image display cell is absorbed by the polarizing plate 5 in the absorption axis direction of the polarizing plate 5 and only the light in the transmission axis direction orthogonal to the absorption axis direction is emitted to the touch panel sensor 3 side. Is done.

As the polarizing plate 5, a polarizing plate having an appropriate absorption type linear polarizer is used. As such a polarizing plate, for example, a polarizing plate made of a polyvinyl alcohol-based stretched film containing iodine is suitably used.

[Touch panel sensor]
The touch panel sensor 3 is disposed on the image display panel 2 (on the operator side), and uses, for example, a change in capacitance that occurs when an external conductor such as a human finger comes into contact (approaching). It is a sensor that detects the position of an external conductor such as a finger.
The touch panel sensor 3 is a projection type that identifies the coordinates of a finger by detecting a change in capacitance of a detection electrode (in particular, a detection electrode extending in the X direction and a detection electrode extending in the Y direction) that is in contact with or close to the finger. A capacitive touch panel sensor is preferably used. As the touch panel sensor 3, for example, a resistive film type touch panel sensor may be used.
The configuration of the touch panel sensor 3 is not particularly limited as long as it includes a substrate exhibiting optical anisotropy, but is a conductive film having a substrate exhibiting optical anisotropy and a detection electrode disposed on at least one surface of the substrate. It is preferable to contain at least. The detection electrode constitutes a conductive part in the conductive film.
As described above, a substrate exhibiting optical anisotropy is a substrate having birefringence in the in-plane and thickness directions, and the substrate is generally excellent in mechanical properties.
Hereinafter, a preferred embodiment of the touch panel sensor 3 including at least a conductive film having a substrate exhibiting optical anisotropy and a detection electrode disposed on at least one surface of the substrate will be described in detail with reference to the drawings. In addition, the board | substrate 12 shown in FIG. 3 mentioned later is a board | substrate which shows optical anisotropy.

3 and 4 are diagrams illustrating an example of a capacitive touch panel sensor using a single conductive film. FIG. 3 shows a plan view of the touch panel sensor 300. FIG. 4 is a cross-sectional view taken along the cutting line AA in FIG. 3 and 4 are schematically shown to facilitate understanding of the layer configuration of the touch panel sensor, and are not drawings that accurately represent the arrangement of each layer.
The touch panel sensor 300 includes a substrate 12, a first detection electrode 14 disposed on one main surface (on the surface) of the substrate 12, a first lead wiring 16, a first transparent resin layer 40, and a first protection. A substrate 50, a second detection electrode 18 disposed on the other main surface (back surface) of the substrate 12, a second lead wiring 20, a second transparent resin layer 42, and a second protective substrate 52 are provided. . The region where the first detection electrode 14 and the second detection electrode 18 are provided constitutes an input region E _I that can be input by the user, and the outer region E _O located outside the input region E _I is the first region. A first lead-out wiring 16, a second lead-out wiring 20, and a flexible printed wiring board (not shown) are arranged. Moreover, the board | substrate 12, the 1st detection electrode 14, and the 2nd detection electrode 18 comprise an electroconductive film.
Below, the said structure is explained in full detail.

The substrate 12 plays a role of supporting a first detection electrode 14 and a second detection electrode 18 to be described later in the input region E _I , and supports a first lead wiring 16 and a second lead wiring 20 to be described later in the outer region E _O. It is a member that plays the role of
The board | substrate 12 satisfy | fills the relationship of the following formula | equation (1).
Formula (1): Nz> 3.0
Especially, it is preferable that Nz is 4.0 or more at the point by which the position detection accuracy degradation of a touch panel under high temperature, high humidity is suppressed more. Although the upper limit of Nz is not specifically limited, 20 or less is preferable and 10 or less is more preferable from the point which prevents the fracture | rupture by extending | stretching of a biaxially stretched film.
When Nz is 3.0 or less, the position detection accuracy of the touch panel is likely to deteriorate.
Nz represents the Nz coefficient, nx is the maximum refractive index in the substrate surface at a wavelength of 550 nm, ny is the refractive index in the direction orthogonal to nx in the substrate surface at a wavelength of 550 nm, and the refractive index is in the substrate thickness direction at a wavelength of 550 nm. When the rate is nz, this is a value obtained by Nz = (nx−nz) / (nx−ny).

The value of nx of the substrate 12 is 1.60 or more, and is preferably 1.61 or more, more preferably 1.65 or more in terms of further suppressing the occurrence of deterioration in the position detection accuracy of the touch panel. The upper limit is not particularly limited, but is usually 1.70 or less in many cases.
The value of ny of the substrate 12 is not particularly limited as long as it satisfies the relationship of the Nz coefficient. However, the difference from nx (nx−ny) is preferably within 0.05, and is preferably within 0.03. preferable. The lower limit is not particularly limited, but usually the difference from nx (nx−ny) is greater than zero.
The value of nz of the substrate 12 is not particularly limited as long as it satisfies the relationship of the Nz coefficient, but is preferably 1.55 or less, and more preferably 1.50 or less. The lower limit is not particularly limited, but is usually 1.45 or more in many cases.
A biaxially stretched substrate is preferably used as the substrate satisfying the above Nz and nx.

Orthogonal in that the in-plane slow axis of the substrate 12 and the vibration direction of the linearly polarized light emitted from the image display panel 2 described above are orthogonal or parallel, and the occurrence of rainbow unevenness is further suppressed. It is preferable that If this is not the case, rainbow unevenness occurs more. The definitions of orthogonal and parallel are as described above.
In addition, the said aspect is synonymous with arrange | positioning so that the in-plane slow axis of the board | substrate 12 and the transmission axis of the polarizing plate 5 (viewing side polarizing plate) in the image display panel 2 may become orthogonal or parallel. is there.

In the above, the Nz and nx of the substrate 12 and the arrangement of the in-plane slow axis of the substrate 12 and the vibration direction of the linearly polarized light are defined. If included, like the substrate 12, those substrates also have predetermined Nz and nx, and the in-plane slow axis of the substrate and the vibration direction of the linearly polarized light satisfy the predetermined arrangement. More specifically, as described later, when the first protective substrate 50 or the second protective substrate 52 exhibits optical anisotropy, they also satisfy the above-described Nz and nx, as in the substrate 12, and The in-plane slow axis and the vibration direction of linearly polarized light are arranged so as to be orthogonal or parallel to each other.

Re (550) which is a retardation value measured at a wavelength of 550 nm of the substrate 12 is not particularly limited, but is preferably 1000 to 3500 nm from the viewpoint of suppressing generation of rainbow unevenness.
It is preferable that the substrate 12 appropriately transmits light. Specifically, the total light transmittance of the substrate 12 is preferably 85 to 100%.

The substrate 12 preferably has an insulating property. That is, the substrate 12 is preferably a layer for ensuring the insulation between the first detection electrode 14 and the second detection electrode 18.
The substrate 12 is preferably a transparent substrate. Specific examples thereof include an insulating resin substrate, a ceramic substrate, and a glass substrate. Among these, an insulating resin substrate is preferable because of its excellent toughness.
More specifically, the material constituting the substrate 12 is polyethylene terephthalate, polyethersulfone, polyacrylic resin, polyurethane resin, polyester, polycarbonate, polysulfone, polyamide, polyarylate, polyolefin, cellulose resin, polychlorinated resin. Examples thereof include vinyl and cycloolefin resins.
Especially, the board | substrate (polyester film) which has polyester as a main component is used suitably from a mechanical strength, dimensional stability, and a heat resistant viewpoint. Examples of the polyester include terephthalic acid, isophthalic acid, orthophthalic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, and diphenylcarboxylic acid. , Diphenoxyethanedicarboxylic acid, diphenylsulfonecarboxylic acid, anthracenedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, hexahydroterephthalic acid, hexahydroisophthalic acid , Malonic acid, dimethylmalonic acid, succinic acid, 3,3-diethylsuccinic acid, glutaric acid, 2,2-dimethylglutaric acid, adipic acid, 2-methyladipic acid, trimethyladipic acid, pimelic acid, azelaic acid, dimer , Dicarboxylic acids such as sebacic acid, suberic acid, dodecadicarboxylic acid, and ethylene glycol, propylene glycol, hexamethylene glycol, neopentyl glycol, 1,2-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, decamethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexadiol, 2,2-bis (4-hydroxyphenyl) propane, bis (4-hydroxyphenyl) sulfone, etc. These diols are each a homopolymer obtained by polycondensation of one kind, a copolymer obtained by polycondensation of one or more dicarboxylic acids and two or more diols, or two or more dicarboxylic acids and one or more kinds of diols. Copolymers obtained by polycondensation of diols, and their homopoly It can include any of the polyester resin blend resin obtained by blending two or more of the chromatography and copolymers. Among these, from the viewpoint of showing crystallinity of the polyester, an aromatic polyester is preferable, polyethylene terephthalate (PET) or polyethylene naphthalate (PEN) is particularly preferable, and polyethylene terephthalate is most preferable.

The polyester film can be obtained by, for example, a method in which the above polyester-based resin is melt-extruded on a casting drum and then cooled and solidified. In addition, when using what has an aromatic polyester as a main component as the board | substrate 12, this board | substrate 12 may contain resin, an additive, etc. other than aromatic polyester. “The main component is aromatic polyester” means that the aromatic polyester is 50% by weight or more, preferably 60% by weight or more, more preferably 70% or more, further preferably 80% or more with respect to the total weight of the substrate 12. Means that.
In addition, from the viewpoint of imparting crystallinity to the polyester film and achieving the above characteristics, a biaxially stretched polyester film can be suitably used as the substrate.

3 and 4, the substrate 12 is a single layer, but may be a multilayer of two or more layers.
The thickness of the substrate 12 (when the substrate 12 is a multilayer of two or more layers is not particularly limited), it is preferably 5 to 350 μm, more preferably 30 to 150 μm. Within the above range, desired visible light transmittance can be obtained, and handling is easy.
3 and 4, the planar view shape of the substrate 12 is substantially rectangular, but is not limited thereto. For example, it may be circular or polygonal.

The first detection electrode 14 and the second detection electrode 18 are sensing electrodes that sense a change in capacitance, and constitute a sensing unit (sensor unit). That is, when the fingertip is brought into contact with the touch panel, the mutual capacitance between the first detection electrode 14 and the second detection electrode 18 changes, and the position of the fingertip is calculated by the IC circuit based on the change amount.
First detection electrode 14, which has a role to detect the input position in the X direction of the finger of the user in proximity to the input region E _I, has the function of generating an electrostatic capacitance between the finger ing. The first detection electrodes 14 are electrodes that extend in a first direction (X direction) and are arranged at a predetermined interval in a second direction (Y direction) orthogonal to the first direction. Includes patterns.
Second detection electrode 18, which has a role to detect the input position in the Y direction of the finger of the user in proximity to the input region E _I, has the function of generating an electrostatic capacitance between the finger ing. The second detection electrodes 18 are electrodes that extend in the second direction (Y direction) and are arranged at a predetermined interval in the first direction (X direction), and include a predetermined pattern as will be described later. In FIG. 3, five first detection electrodes 14 and five second detection electrodes 18 are provided, but the number is not particularly limited and may be plural.

In FIG. 3, the first detection electrode 14 and the second detection electrode 18 can be composed of, for example, conductive thin wires. FIG. 5 shows an enlarged plan view of a part of the first detection electrode 14. As shown in FIG. 5, the first detection electrode 14 is composed of conductive thin wires 30, and includes a plurality of lattices 32 formed of intersecting conductive thin wires 30. In other words, the first detection electrode 14 has a mesh pattern composed of a plurality of conductive thin wires that intersect. Note that, similarly to the first detection electrode 14, the second detection electrode 18 also includes a plurality of lattices 32 formed by intersecting conductive thin wires 30.

Examples of the material of the conductive thin wire 30 include metals and alloys such as gold (Au), silver (Ag), copper (Cu), and aluminum (Al), ITO, tin oxide, zinc oxide, cadmium oxide, gallium oxide, Examples thereof include metal oxides such as titanium oxide. Especially, it is preferable that it is silver from the reason for which the electroconductivity of the electroconductive fine wire 30 is excellent.

The conductive fine wire 30 preferably contains a binder from the viewpoint of adhesion between the conductive fine wire 30 and the substrate 12.
The binder is preferably a water-soluble polymer because the adhesion between the conductive thin wire 30 and the substrate 12 is more excellent. Examples of the binder include gelatin, carrageenan, polyvinyl alcohol (PVA), polyvinyl pyrrolidone (PVP), polysaccharides such as starch, cellulose and derivatives thereof, polyethylene oxide, polysaccharides, polyvinylamine, chitosan, polylysine, polyacryl. Examples include acid, polyalginic acid, polyhyaluronic acid, carboxycellulose, gum arabic, and sodium alginate. Among these, gelatin is preferable because the adhesion between the conductive thin wire 30 and the substrate 12 is more excellent.
In addition to lime-processed gelatin, acid-processed gelatin may be used as gelatin, and gelatin hydrolyzate, gelatin enzyme decomposition product, and other gelatins modified with amino groups and carboxyl groups (phthalated gelatin, acetylated gelatin) Can be used.

The volume ratio of metal to binder (metal volume / binder volume) in the conductive thin wire 30 is preferably 1.0 or more, and more preferably 1.5 or more. By setting the volume ratio of the metal and the binder to 1.0 or more, the conductivity of the conductive thin wire 30 can be further increased. The upper limit is not particularly limited, but is preferably 4.0 or less and more preferably 2.5 or less from the viewpoint of productivity.
The volume ratio of the metal and the binder can be calculated from the density of the metal and the binder contained in the conductive thin wire 30. For example, when the metal is silver, the density of silver is 10.5 g / cm ³ , and when the binder is gelatin, the density of gelatin is 1.34 g / cm ³ .

The line width of the conductive thin wire 30 is not particularly limited, but is preferably 30 μm or less, more preferably 15 μm or less, still more preferably 10 μm or less, and particularly preferably 9 μm or less, from the viewpoint that a low-resistance electrode can be formed relatively easily. 7 μm or less is most preferable, 0.5 μm or more is preferable, and 1.0 μm or more is more preferable.
The thickness of the conductive thin wire 30 is not particularly limited, but can be selected from 0.00001 to 0.2 mm from the viewpoint of conductivity and visibility, but is preferably 30 μm or less, more preferably 20 μm or less, and 0.01 Is more preferably from 9 to 9 μm, most preferably from 0.05 to 5 μm.

The lattice 32 includes an opening region surrounded by the thin conductive wires 30. The length W of one side of the grating 32 is preferably 800 μm or less, more preferably 600 μm or less, preferably 50 μm or more, and more preferably 400 μm or more.
In the first detection electrode 14 and the second detection electrode 18, the aperture ratio is preferably 85% or more, more preferably 90% or more, and most preferably 95% or more from the viewpoint of visible light transmittance. preferable. The aperture ratio corresponds to the ratio of the transmissive portion excluding the conductive thin wire 30 in the first detection electrode 14 or the second detection electrode 18 in the predetermined region.

The lattice 32 has a substantially rhombus shape. However, other polygonal shapes (for example, a triangle, a quadrangle, a hexagon, and a random polygon) may be used. Further, the shape of one side may be a curved shape or a circular arc shape in addition to a linear shape. In the case of the arc shape, for example, the two opposing sides may have an outwardly convex arc shape, and the other two opposing sides may have an inwardly convex arc shape. The shape of each side may be a wavy shape in which an outwardly convex arc and an inwardly convex arc are continuous. Of course, the shape of each side may be a sine curve.
In FIG. 5, the conductive thin wire 30 is formed as a mesh pattern, but is not limited to this mode, and may be a stripe pattern.

In FIG. 3, the first detection electrode 14 and the second detection electrode 18 are configured with a mesh structure of the conductive thin wires 30, but are not limited to this mode. For example, ITO, tin oxide, zinc oxide A transparent metal oxide thin film such as cadmium oxide, gallium oxide, or titanium oxide may also be used. Further, the first detection electrode 14 and the second detection electrode 18 may be formed of metal oxide particles, metal paste such as silver paste or copper paste, and metal nanowire particles such as silver nanowire or copper nanowire. Among these, silver nanowires are preferable because they are excellent in conductivity and transparency.
The patterning of the electrode part can be selected according to the material of the electrode part, and a photolithography method, a resist mask screen printing-etching method, an ink jet method, a printing method, or the like may be used.

The first lead wiring 16 and the second lead wiring 20 are members that play a role in applying a voltage to the first detection electrode 14 and the second detection electrode 18, respectively.
The first lead-out wiring 16 is disposed on the substrate 12 in the outer region E _O , one end thereof is electrically connected to the corresponding first detection electrode 14, and the other end is an external continuity in which a flexible printed wiring board or the like is disposed. It is located in the region _{G I.}
The second lead-out wiring 20 is disposed on the substrate 12 in the outer region E _O , one end of which is electrically connected to the corresponding second detection electrode 18, and the other end is an external continuity in which a flexible printed wiring board or the like is disposed. It is located in the region _{G I.}
In FIG. 3, five first lead wires 16 and five second lead wires 20 are shown, but the number is not particularly limited, and a plurality of the first lead wires 16 are usually arranged according to the number of detection electrodes. The

Examples of the wiring material constituting the first lead wiring 16 and the second lead wiring 20 include metals such as gold (Au), silver (Ag), copper (Cu), tin oxide, zinc oxide, cadmium oxide, Examples thereof include metal oxides such as gallium oxide and titanium oxide. Among these, silver is preferable because of its excellent conductivity. Moreover, you may be comprised by metal or alloy thin films, such as metal pastes, such as a silver paste and a copper paste, aluminum (Al), molybdenum (Mo), and palladium (Pd). In the case of a metal paste, a screen printing or ink jet printing method is used, and in the case of a metal or alloy thin film, a patterning method such as a photolithography method is suitably used for the sputtered film.
In addition, it is preferable that the binder is contained in the 1st lead-out wiring 16 and the 2nd lead-out wiring 20 from the point which adhesiveness with the board | substrate 12 is more excellent. The kind of binder is as above-mentioned.

The first transparent resin layer 40 and the second transparent resin layer 42 are disposed on the first detection electrode 14 and the second detection electrode 18 in the input region E _I , respectively, and the first detection electrode 14 and the first protective substrate 50 are disposed. And a layer (particularly an adhesive transparent resin layer) for ensuring adhesion between the second detection electrode 18 and the second protective substrate 52.
The thickness of the first transparent resin layer 40 and the second transparent resin layer 42 is not particularly limited, but is preferably 5 to 350 μm, and more preferably 20 to 150 μm. Within the above range, desired visible light transmittance can be obtained, and handling is easy.
The total light transmittance of the first transparent resin layer 40 and the second transparent resin layer 42 is preferably 85 to 100%.
In addition, the 1st transparent resin layer 40 and the 2nd transparent resin layer 42 usually show optical isotropy.

As a material constituting the first transparent resin layer 40 and the second transparent resin layer 42, a known pressure-sensitive adhesive is preferably used, and examples thereof include a rubber-based pressure-sensitive adhesive, an acrylic pressure-sensitive adhesive, and a silicone-based pressure-sensitive adhesive. It is done. Among these, an acrylic pressure-sensitive adhesive is preferable from the viewpoint of excellent transparency.
The acrylic pressure-sensitive adhesive that is a preferred embodiment of the pressure-sensitive adhesive is mainly composed of an acrylic polymer having a repeating unit derived from an alkyl (meth) acrylate. (Meth) acrylate refers to acrylate and / or methacrylate. Among the acrylic pressure-sensitive adhesives, an acrylic polymer having a repeating unit derived from an alkyl (meth) acrylate having an alkyl group having about 1 to 12 carbon atoms is preferable because the adhesiveness is more excellent. An acrylic polymer having a number of repeating units derived from alkyl methacrylate and a number of repeating units derived from alkyl acrylate having the above carbon number is more preferred.
In the repeating unit in the acrylic polymer, a repeating unit derived from (meth) acrylic acid may be contained.

The first protective substrate 50 and the second protective substrate 52 are substrates disposed on the first transparent resin layer 40 and the second transparent resin layer 42, respectively, and the first detection electrode 14 and the second detection electrode 18 from the external environment. In general, the main surface of one of the protective substrates constitutes a touch surface.
The first protective substrate 50 and the second protective substrate 52 are preferably transparent substrates, and a plastic film, a plastic plate, a glass plate, or the like is used. It is desirable that the thickness of the layer is appropriately selected according to each application.
Examples of the raw material for the plastic film and the plastic plate include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN); polyolefins such as polyethylene (PE), polypropylene (PP), polystyrene, and EVA; Resin; In addition, polycarbonate (PC), polyamide, polyimide, acrylic resin, triacetyl cellulose (TAC), cycloolefin resin (COP), and the like can be used.

In addition, as the 1st protective substrate 50 and the 2nd protective substrate 52, the board | substrate which shows optical isotropy from the point which is excellent in mechanical strength is used preferably, However, The board | substrate which shows optical anisotropy may be used.
When the first protective substrate 50 and / or the second protective substrate 52 exhibit optical anisotropy, the respective substrates are arranged in the same manner as the substrate 12 with respect to the image display panel 2.
More specifically, when the first protective substrate 50 exhibits optical anisotropy, the in-plane slow axis of the first protective substrate 50 and the vibration direction of the linearly polarized light emitted from the image display panel are orthogonal or parallel. The first protective substrate 50 is arranged so that When the second protective substrate 52 exhibits optical anisotropy, the in-plane slow axis of the second protective substrate 52 and the vibration direction of the linearly polarized light emitted from the image display panel are the same as the first protective substrate 50. The second protective substrate 52 is arranged so that is orthogonal or parallel to each other.
Furthermore, when the 1st protective substrate 50 and / or the 2nd protective substrate 52 show optical anisotropy, Nz and nx of each board | substrate show the range similar to the said board | substrate 12. FIG. More specifically, when the first protective substrate 50 exhibits optical anisotropy, the first protective substrate 50 satisfies the relationship of the above formula (1): Nz> 3.0, and nx is 1.6 or more. The preferred embodiment is the same as that of the substrate 12. When the second protective substrate 52 exhibits optical anisotropy, the second protective substrate 52 satisfies the relationship of the above formula (1): Nz> 3.0, and nx is 1.6 or more. The preferred embodiment is the same as that of the substrate 12.

The second protective substrate 52 may not be used, and the second transparent resin layer 42 may be in direct contact with the image display panel 2.
A hard coat layer may be provided on the surfaces of the first protective substrate 50 and the second protective substrate 52. The hard coat layer is provided for the purpose of preventing the scratch by imparting hardness to the substrate.
Examples of the resin that forms the hard coat layer include thermosetting resins, thermoplastic resins, ultraviolet curable resins, electron beam curable resins, and two-component mixed resins, among which curing by ultraviolet irradiation. An ultraviolet curable resin capable of efficiently forming a hard coat layer by a simple processing operation is preferable. Examples of the ultraviolet curable resin include various types such as polyester, acrylic, urethane, amide, silicone, and epoxy, and examples include ultraviolet curable monomers, oligomers, and polymers. Examples of the ultraviolet curable resin preferably used include those having an ultraviolet polymerizable functional group, particularly those containing an acrylic monomer or oligomer component having two or more, particularly 3 to 6 functional groups. . Further, an ultraviolet polymerization initiator is blended in the ultraviolet curable resin.
The formation method in particular of a hard-coat layer is not restrict | limited, A suitable system can be employ | adopted.

The external conductive region G _I of FIG. 3, is arranged a flexible printed circuit board (not shown). The flexible printed wiring board is a board in which a plurality of wirings and terminals are provided on a substrate, and is connected to the other end of each of the first lead-out wirings 16 and the other end of each of the second lead-out wirings 20, and is a touch panel sensor. It plays a role of connecting 300 and an external device (for example, an image display panel).

(Method for manufacturing touch panel sensor)
The manufacturing method in particular of the touch panel sensor 300 is not restrict | limited, A well-known method is employable. First, as a method of manufacturing the detection electrode and the lead-out wiring, a photoresist film on the metal foil formed on both main surfaces of the substrate 12 is exposed and developed to form a resist pattern, and the metal exposed from the resist pattern A method of etching the foil is mentioned. Further, a method of printing a paste containing metal fine particles or metal nanowires on both main surfaces of the substrate 12 and performing metal plating on the paste can be mentioned. Moreover, the method of printing and forming on the board | substrate 12 with a screen printing plate or a gravure printing plate, or the method of forming by an inkjet is also mentioned.

Furthermore, in addition to the above method, a method using silver halide can be mentioned. More specifically, first, silver halide was used as a method of forming the first detection electrode 14 and the first lead wiring 16, and the second detection electrode 18 and the second lead wiring 20 on the substrate 12. A method is mentioned. More specifically, the step (1) of forming a silver halide emulsion layer (hereinafter also referred to simply as a photosensitive layer) containing silver halide and gelatin on both surfaces of the substrate 12, respectively, and exposing the photosensitive layer After that, a method including a step (2) of forming the first detection electrode 14 and the first lead wiring 16, and the second detection electrode 18 and the second lead wiring 20 by developing is given.
Below, each process is demonstrated.

[Step (1): Photosensitive layer forming step]
Step (1) is a step of forming a photosensitive layer containing silver halide and gelatin on both surfaces of the substrate 12.
The method for forming the photosensitive layer is not particularly limited, but from the viewpoint of productivity, the photosensitive layer forming composition containing silver halide and a binder is brought into contact with the substrate 12, and the photosensitive layer is formed on both surfaces of the substrate 12. The method of forming is preferred.
Below, after explaining in full detail the aspect of the composition for photosensitive layer formation used with the said method, the procedure of a process is explained in full detail.

The composition for forming a photosensitive layer contains silver halide and gelatin.
The halogen element contained in the silver halide may be any of chlorine, bromine, iodine and fluorine, or a combination thereof. As the silver halide, for example, silver halides mainly composed of silver chloride, silver bromide and silver iodide are preferably used, and silver halides mainly composed of silver bromide and silver chloride are preferably used.
The types of gelatin are as described above.
The volume ratio of silver halide and gelatin contained in the composition for forming a photosensitive layer is not particularly limited, and is appropriately adjusted so as to be within a suitable volume ratio range of the metal and the binder in the conductive thin wire 30 described above. Is done.

The composition for forming a photosensitive layer contains a solvent, if necessary.
Examples of the solvent used include water, organic solvents (for example, alcohols such as methanol, ketones such as acetone, amides such as formamide, sulfoxides such as dimethyl sulfoxide, esters such as ethyl acetate, ethers, and the like. Etc.), ionic liquids, or mixed solvents thereof.
The content of the solvent to be used is not particularly limited, but is preferably in the range of 30 to 90% by mass, and more preferably in the range of 50 to 80% by mass with respect to the total mass of silver halide and binder.

(Process procedure)
A method for bringing the composition for forming a photosensitive layer and the substrate 12 into contact with each other is not particularly limited, and a known method can be adopted. For example, the method of apply | coating the composition for photosensitive layer formation to the board | substrate 12, the method of immersing the board | substrate 12 in the composition for photosensitive layer formation, etc. are mentioned.
The silver halide content in the photosensitive layer is not particularly limited, but is preferably 1.0 to 20.0 g / m ^{2 in} terms of silver, and preferably 5.0 to 15.0 g / m ^{2 in} terms of more excellent conductive properties. ² is more preferable.
In addition, you may further provide the protective layer which consists of a binder on a photosensitive layer as needed. By providing the protective layer, scratches can be prevented and mechanical properties can be improved.

[Step (2): Exposure and development step]
In the step (2), the photosensitive layer obtained in the above step (1) is subjected to pattern exposure and then developed to thereby perform the first detection electrode 14 and the first lead wiring 16, and the second detection electrode 18 and the second detection electrode. This is a step of forming the two lead wirings 20.
Hereinafter, the pattern exposure process will be described in detail, and then the development process will be described in detail.

(Pattern exposure)
By subjecting the photosensitive layer to pattern exposure, the silver halide in the photosensitive layer in the exposed region forms a latent image. In the region where the latent image is formed, the first detection electrode 14 and the first lead-out wiring 16, and the second detection electrode 18 and the second lead-out wiring 20 are formed by a development process described later. On the other hand, in an unexposed area that has not been exposed, the silver halide dissolves and flows out of the photosensitive layer during the fixing process described later, and a transparent film is obtained.
The light source used in the exposure is not particularly limited, and examples thereof include light such as visible light and ultraviolet light, and radiation such as X-rays.
The method for performing pattern exposure is not particularly limited. For example, surface exposure using a photomask may be performed, or scanning exposure using a laser beam may be performed. The shape of the pattern is not particularly limited, and is appropriately adjusted according to the pattern of the conductive fine wire to be formed.

(Development processing)
The development processing method is not particularly limited, and a known method can be employed. For example, a usual development processing technique used for silver salt photographic film, photographic paper, film for printing plate making, emulsion mask for photomask, and the like can be used.
The type of the developer used in the development process is not particularly limited. For example, PQ developer, MQ developer, MAA developer and the like can be used.
The development process can include a fixing process performed for the purpose of removing and stabilizing the silver salt in the unexposed part. For the fixing process, a technique of fixing process used for silver salt photographic film, photographic paper, film for printing plate making, emulsion mask for photomask and the like can be used.
The fixing temperature in the fixing step is preferably about 20 ° C. to about 50 ° C., more preferably 25 ° C. to 45 ° C. The fixing time is preferably 5 seconds to 1 minute, more preferably 7 seconds to 50 seconds.
The mass of the metallic silver contained in the exposed area (conductive thin wire) after the development treatment is preferably a content of 50% by mass or more based on the mass of silver contained in the exposed area before the exposure, More preferably, it is at least mass%. If the mass of silver contained in the exposed portion is 50% by mass or more based on the mass of silver contained in the exposed portion before exposure, it is preferable because high conductivity can be obtained.

The method for forming the first transparent resin layer 40 and the second transparent resin layer 42 is not particularly limited, and a method for pasting known transparent resin films or a composition for forming a transparent resin layer for forming a transparent resin layer is applied. And a method of forming a layer.
A method for forming the first protective substrate 50 and the second protective substrate 52 is not particularly limited, and examples thereof include a method in which protective substrates are bonded to the first transparent resin layer 40 and the second transparent resin layer 42, respectively.

In the above, the aspect in which the first detection electrode and the second detection electrode are disposed on the front surface and the back surface of the substrate has been described in detail, but the touch panel sensor is not limited to this aspect.
Hereinafter, another aspect of the touch panel sensor will be described in detail.
FIG. 6 shows a partial cross-sectional view of the second embodiment of the touch panel sensor.
As shown in FIG. 6, the touch panel sensor 400 is electrically connected to the second substrate 62, the second detection electrode 18 disposed on the second substrate 62, and one end of the second detection electrode 18. A second lead-out wiring (not shown) disposed on the substrate 62, the second transparent resin layer 42, the first detection electrode 14, and a first electrode electrically connected to one end of the first detection electrode 14. A lead wiring 16 (not shown), a first substrate 60 adjacent to the first detection electrode 14 and the first lead wiring 16, a first transparent resin layer 40, and a first protective substrate 50 are provided.
The touch panel sensor 400 shown in FIG. 6 has the same layers as the touch panel sensor 300 shown in FIG. 3 except that the order of the layers is different. Therefore, the same reference numerals are assigned to the same components. The description is omitted. In addition, the 1st board | substrate 60 and the 2nd board | substrate 62 are the layers similar to the board | substrate 12 shown in FIG. 3, Both show optical anisotropy, The definition is as above-mentioned.
Further, a plurality of the first detection electrodes 14 and the second detection electrodes 18 in FIG. 6 are used as shown in FIG. 3, and they are arranged so as to be orthogonal to each other as shown in FIG. .
In addition, the touch panel sensor 400 shown in FIG. 6 prepares two substrates (conductive films) with electrodes having a substrate and detection electrodes arranged on the substrate surface and lead-out wiring, and the detection electrodes face each other. It corresponds to the touch panel obtained by bonding through a transparent resin layer.

In the case of the above aspect, the in-plane slow axis of the first substrate 60 and the in-plane slow axis of the second substrate 62 included in the touch panel sensor 400 are orthogonal to the vibration direction of the linearly polarized light emitted from the image display panel, respectively. Or it arrange | positions so that it may become parallel.
Furthermore, both the first substrate 60 and the second substrate 62 satisfy the above formula (1) and exhibit a predetermined nx.

Hereinafter, another aspect of the touch panel sensor will be described in detail.
FIG. 7 shows a partial cross-sectional view of a third embodiment of the touch panel sensor. As shown in FIG. 7, the touch panel sensor 500 is electrically connected to the second substrate 62, the second detection electrode 18 disposed on the second substrate 62, and one end of the second detection electrode 18. A second lead-out wiring (not shown) disposed on the substrate 62, a second transparent resin layer 42, the first substrate 60, the first detection electrode 14 disposed on the first substrate 60, and the first A first lead wiring (not shown), a first transparent resin layer 40, and a first protective substrate 50 are electrically connected to one end of the detection electrode 14 and disposed on the first substrate 60.
Since the touch panel sensor 500 shown in FIG. 7 has the same layers as the touch panel sensor 400 shown in FIG. 6 except that the order of the layers is different, the same reference numerals are assigned to the same components. The description is omitted.
Further, a plurality of the first detection electrodes 14 and the second detection electrodes 18 in FIG. 7 are used as shown in FIG. 3, and they are arranged so as to be orthogonal to each other as shown in FIG. .
Note that the touch panel sensor 500 shown in FIG. 7 is prepared by preparing two substrates with electrodes (conductive film) having a substrate and detection electrodes and lead wires arranged on the substrate surface, and the substrate in one substrate with electrodes. This corresponds to a touch panel obtained by bonding through a transparent resin layer so that the electrode of the other substrate with an electrode faces each other.

In the case of the above aspect, the in-plane slow axis of the first substrate 60 and the in-plane slow axis of the second substrate 62 included in the touch panel sensor 500 are orthogonal to the vibration direction of the linearly polarized light emitted from the image display panel, respectively. Or it arrange | positions so that it may become parallel.
Furthermore, both the first substrate 60 and the second substrate 62 satisfy the above formula (1) and exhibit a predetermined nx.

An adhesive layer may be disposed between the image display panel and the touch panel sensor as necessary. As the pressure-sensitive adhesive in the pressure-sensitive adhesive layer to be used, those having transparency are preferable. Specifically, for example, acrylic polymer, silicone polymer, polyester, polyurethane, polyamide, polyvinyl ether, vinyl acetate / vinyl chloride copolymer Those having a base polymer such as a modified polyolefin, an epoxy-based polymer, a fluorine-based polymer, a rubber-based polymer such as natural rubber, and synthetic rubber can be appropriately selected and used. In particular, an acrylic pressure-sensitive adhesive is preferably used from the viewpoint that it is excellent in optical transparency, exhibits adhesive properties such as appropriate wettability, cohesiveness and adhesiveness, and is excellent in weather resistance and heat resistance.

Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these.

<Example 1>
(Preparation of silver halide emulsion)
To the following 1 liquid maintained at 38 ° C. and pH 4.5, an amount corresponding to 90% of each of the following 2 and 3 liquids was simultaneously added over 20 minutes while stirring to form 0.16 μm core particles. Subsequently, the following 4 and 5 solutions were added over 8 minutes, and the remaining 10% of the following 2 and 3 solutions were added over 2 minutes to grow to 0.21 μm. Further, 0.15 g of potassium iodide was added and ripened for 5 minutes to complete the grain formation.

1 liquid:
750 ml of water
9g gelatin
Sodium chloride 3g
1,3-Dimethylimidazolidine-2-thione 20mg
Sodium benzenethiosulfonate 10mg
Citric acid 0.7g
Two liquids:
300 ml of water
150 g silver nitrate
3 liquids:
300 ml of water
Sodium chloride 38g
Potassium bromide 32g
Potassium hexachloroiridium (III) (0.005% KCl 20% aqueous solution) 8 ml
Ammonium hexachlororhodate (0.001% NaCl 20% aqueous solution) 10 ml
4 liquids:
100ml water
Silver nitrate 50g
5 liquids:
100ml water
Sodium chloride 13g
Potassium bromide 11g
Yellow blood salt 5mg

Then, it was washed with water by a flocculation method according to a conventional method. Specifically, the temperature was lowered to 35 ° C., and the pH was lowered using sulfuric acid until the silver halide precipitated (the pH was in the range of 3.6 ± 0.2). Next, about 3 liters of the supernatant was removed (first water washing). Further, 3 liters of distilled water was added, and sulfuric acid was added until the silver halide settled. Again, 3 liters of the supernatant was removed (second water wash). The same operation as the second water washing was further repeated once (third water washing) to complete the water washing / desalting step. The emulsion after washing with water and desalting was adjusted to pH 6.4 and pAg 7.5, and gelatin 3.9 g, sodium benzenethiosulfonate 10 mg, sodium benzenethiosulfinate 3 mg, sodium thiosulfate 15 mg and chloroauric acid 10 mg were added. Chemical sensitization to obtain optimum sensitivity at 0 ° C., 100 mg of 1,3,3a, 7-tetraazaindene as stabilizer and 100 mg of proxel (trade name, manufactured by ICI Co., Ltd.) as preservative It was. The finally obtained emulsion contains 0.08 mol% of silver iodide, and the ratio of silver chlorobromide is 70 mol% of silver chloride and 30 mol% of silver bromide. It was a silver iodochlorobromide cubic grain emulsion having a coefficient of 9%.

(Preparation of photosensitive layer forming composition)
1,3,3a, 7-tetraazaindene 1.2 × 10 ⁻⁴ mol / mol Ag, hydroquinone 1.2 × 10 ⁻² mol / mol Ag, citric acid 3.0 × 10 ⁻⁴ mol / Mole Ag and 2,4-dichloro-6-hydroxy-1,3,5-triazine sodium salt (0.90 g / mole Ag) were added, and the pH of the coating solution was adjusted to 5.6 using citric acid, and photosensitivity was achieved. A composition for forming a conductive layer was obtained.

(Photosensitive layer forming step)
A polyethylene terephthalate (PET) film having a thickness of 99.8 μm is subjected to corona discharge treatment, and then a gelatin layer having a thickness of 0.1 μm as an undercoat layer on both sides of the PET film, and an optical density of about 1 on the undercoat layer. An antihalation layer containing a dye that is decolorized by alkali in the developer at 0.0 was provided. On the antihalation layer, the composition for forming a photosensitive layer was applied, a gelatin layer having a thickness of 0.15 μm was further provided, and a PET film having a photosensitive layer formed on both sides was obtained. The obtained film is referred to as film A. The formed photosensitive layer had a silver amount of 6.0 g / m ² and a gelatin amount of 1.0 g / m ² .
Moreover, the used PET film showed optical anisotropy, Nz was 10, Re (550) was 1700 nm, nx was 1.668, ny was 1.651, and nz was 1.495.

(Exposure development process)
Through a photomask in which a touch panel sensor pattern (first detection electrode and second detection electrode) and a lead wiring portion (first lead wiring and second lead wiring) as shown in FIG. 3 are arranged on both surfaces of the film A, Exposure was performed using parallel light using a high-pressure mercury lamp as a light source. After the exposure, development was performed with the following developer, and further development processing was performed using a fixing solution (trade name: N3X-R for CN16X, manufactured by Fuji Film Co., Ltd.). Furthermore, by rinsing with pure water and drying, a PET film having a detection electrode having a mesh pattern made of Ag fine wires and a gelatin layer on both surfaces was obtained. The gelatin layer was formed between the Ag fine wires. The resulting film is referred to as film B.
The first detection electrode arranged on the PET film is an electrode extending in the X direction, the second detection electrode is an electrode extending in the Y direction, and there are 32 X detection electrodes (length: 170 mm), Y detection electrodes. (Length: 300 mm) was 56.

(Developer composition)
The following compounds are contained in 1 liter (L) of the developer.
Hydroquinone 0.037mol / L
N-methylaminophenol 0.016 mol / L
Sodium metaborate 0.140 mol / L
Sodium hydroxide 0.360 mol / L
Sodium bromide 0.031 mol / L
Potassium metabisulfite 0.187 mol / L

Using the film B obtained above, a touch panel was manufactured by the following method.
A film in which OCA (# 8146-4: 100 micrometers thick) manufactured by 3M was bonded to one surface (top surface) of the film B obtained above was prepared. The OCA on the other end of each of the first lead-out wiring portion and the second lead-out wiring portion corresponding to the FPC (flexible printed wiring board) pressure-bonding portion was previously made so that the hollow FPC can be pressure-bonded.
Adjust the outer shape of the above laminate (film B + OCA) to approximately the same size as 0.7mm thick soda-lime glass, and press-fit the FPC with Sony Chemicals ACF (CP906AM-25AC), then the top side The above-mentioned soda lime glass was affixed to produce a touch panel sensor.
A touch panel was produced by the following method using the touch panel sensor obtained above.
On the surface of the touch panel sensor obtained above (the bottom surface, the surface opposite to the surface with soda lime glass), put the necessary amount for the final thickness of 300 μm with Kyotsuri Chemical OCR (HRJ-21) dispenser, After bonding with a liquid crystal display including a front polarizing plate, a touch panel was prepared by ultraviolet curing.
In addition, the film B was arrange | positioned so that the in-plane slow axis of the PET film in the film B and the transmission axis of the front polarizing plate of a liquid crystal display may become parallel (0 degree).
Further, the touch panel sensor in the formed touch panel corresponds to an aspect in which the second protective substrate 52 in FIG. 3 is not provided.

<Example 2>
A touch panel was produced by the following method using the film B produced in Example 1.
On one surface (bottom surface) of the film B obtained above, 3M OCA (# 8146-4: 100 micrometers thick), Kimoto hard coat film (G1SBF: 50 micrometers thick) (hereinafter, HC-PET) was laminated in this order. Further, an OCA (# 8146-4: 100 micrometer thickness) manufactured by 3M was bonded to the other surface (top surface) of the film B. The OCA and hard coat film on the other end of each of the first lead wiring and the second lead wiring corresponding to the FPC press-bonding portion were previously made so that the hollow FPC can be pressure-bonded.
After adjusting the outer shape of the laminate obtained above to the same size as 0.7mm thick soda lime glass with a sensor size, and FPC bonded with Sony Chemicals ACF (CP906AM-25AC), the top side The above-mentioned soda lime glass was affixed to produce a touch panel sensor.
A touch panel was produced by the following method using the touch panel sensor obtained above.
A double-sided adhesive tape (Nitto Denko, 5000NS) is applied to the peripheral edge of the hard coat film surface of the touch panel sensor obtained above, and the front polarizing plate of the liquid crystal display including the front polarizing plate and the hard coat film are faced to each other. The touch panel was produced by bonding. In the obtained touch panel, an air layer surrounded by a double-sided adhesive tape exists between the liquid crystal display and the touch panel sensor.
In addition, the film B was arrange | positioned so that the in-plane slow axis of the PET film in the film B and the transmission axis of a front polarizing plate may become parallel (0 degree). The HC-PET corresponding to the second protective substrate was arranged so that the in-plane slow axis of the HC-PET and the transmission axis of the front polarizing plate were parallel (0 °). The PET film in HC-PET exhibited optical anisotropy, Nz was 4.3, Re (550) was 2800 nm, and nx was 1.642.
Moreover, the touch panel sensor in the formed touch panel corresponds to the aspect in FIG.

<Example 3>
A touch panel was produced according to the same procedure as in Example 2 except that the in-plane slow axis of HC-PET and the transmission axis of the front polarizing plate were arranged to be orthogonal to each other.

<Example 4>
(Formation of conductive film)
On the ITO transparent conductive layer of the ITO substrate including the PET film (thickness: 100.1 μm) and the ITO transparent conductive layer, an etching mask material is formed by a negative photoresist method and immersed in an etching solution for dissolving ITO. A conductive film provided with a detection electrode was formed. The procedure of each process is shown below.
The PET film used exhibited optical anisotropy, Nz was 10, Re (550) was 1700 nm, nx was 1.668, ny was 1.651, and nz was 1.495.

-Resist patterning (etching mask material application) process-
On the surface of the ITO transparent conductive layer, a photosensitive composition (1) described later was applied with a bar so as to have a dry film thickness of 5 μm, and dried in an oven at 150 ° C. for 5 minutes. The substrate was exposed to 400 mJ / cm ² (illuminance: 50 mW / cm ² ) with a high-pressure mercury lamp i-line (365 nm) from above the exposure glass mask.
The exposed substrate was subjected to shower development for 60 seconds with a 1% aqueous sodium hydroxide solution (35 ° C.). The shower pressure was 0.08 MPa, and the time until the stripe pattern appeared was 30 seconds. After rinsing with a shower of pure water, it was dried at 50 ° C. for 1 minute to produce a conductive member with a resist pattern.
In addition, the mask which can form the detection electrode of a capacitive touch panel sensor was used for the exposure glass mask.
-Etching process-
The conductive member with a resist pattern was immersed in an etching solution for ITO. Etching is performed by immersing in an etching solution adjusted to 35 ° C. for 2 minutes, rinsing with a shower of pure water, then blowing off water on the surface of the sample with an air knife, drying at 60 ° C. for 5 minutes, and a pattern with a resist pattern A conductive member was produced.
-Resist stripping process-
The patterned conductive member with a resist pattern after etching was subjected to shower development for 75 seconds with a 2.38% tetramethylammonium hydroxide aqueous solution kept at 35 ° C. The shower pressure was 3.0 MPa. After rinsing with a pure water shower, water on the sample surface was blown off with an air knife and dried at 60 ° C. for 5 minutes to produce a conductive film.
In addition, as a conductive film, the pattern of the detection electrode was changed and the two conductive films (a 1st conductive film and a 2nd conductive film) were produced. The detection electrode of the first conductive film was an electrode extending in the X direction (length: 170 mm), and there were 32 detection electrodes. The number of detection electrodes of the second conductive film was 56 (length: 300 mm) extending in the Y direction.

-Preparation of photosensitive composition (1)-
MAA (methacrylic acid; 7.79 g) and BzMA (benzyl methacrylate; 37.21 g) are used as monomer components constituting the copolymer, and AIBN (2,2′-azobis (isobutyro) is used as a radical polymerization initiator. Nitrile); 0.5 g), and a PGMEA solution of the binder (A-1) represented by the following formula (solid) by solidifying these in a solvent PGMEA (propylene glycol monomethyl ether acetate; 55.00 g) The partial concentration was 45% by mass). The polymerization temperature was adjusted to 60 to 100 ° C.
The molecular weight was measured using gel permeation chromatography (GPC). As a result, the weight average molecular weight (Mw) in terms of polystyrene was 30,000, and the molecular weight distribution (Mw / Mn) was 2.21.

3.80 parts by mass of binder (A-1) (solid content: 40.0% by mass, PGMEA solution), 1.59 parts by mass of KAYARAD DPHA (manufactured by Nippon Kayaku Co., Ltd.) as a photosensitive compound, as a photopolymerization initiator IRGACURE 379 (manufactured by Ciba Specialty Chemicals Co., Ltd.) 0.159 parts by mass, EHPE-3150 (manufactured by Daicel Chemical Co., Ltd.) 0.150 parts by mass as a cross-linking agent, Megafac F781F (manufactured by DIC Corporation) 0.002 1 part by mass and 19.3 parts by mass of PGMEA were added and stirred to prepare a photosensitive composition (1).

(Peripheral wiring formation)
The lead-out wiring (peripheral wiring) formed by the patterning and connected to the detection electrode in the conductive film was produced as follows. That is, a silver paste (Dotite FA-401CA, manufactured by Fujikura Kasei) was printed by a screen printer, and then cured by annealing at 130 ° C. for 30 minutes to form peripheral wiring.
The screen printing plate used was a printing plate capable of forming a capacitive touch panel peripheral wiring.

(Touch panel manufacturing method)
Using the conductive film produced above, a touch panel was produced by the following method.
An OCA (# 8146-4: 100 micrometer thickness) manufactured by 3M was bonded to the ITO layer surface of the second conductive film (bottom surface) obtained above, and another first conductive film was passed through the OCA. What was bonded to the surface opposite to the side having the ITO layer (top surface) was produced. The obtained laminate has a PET film, an ITO layer, an OCA, a PET film, and an ITO layer in this order. Note that the OCA on the other end of each of the first lead-out wiring and the second lead-out wiring corresponding to the FPC crimping portion can be preliminarily crimped with the FPC.
3M OCA (# 8146-4: 100 micrometer thickness) is pasted on the ITO layer (top surface) of the above laminate, and the outer shape is adjusted to the same size as 0.7mm thick soda lime glass with a sensor size. The FPC was pressure bonded with Sony Chemicals ACF (CP906AM-25AC), and then the soda lime glass was pasted on the top side to produce a touch panel sensor.
A touch panel was produced by the following method using the touch panel sensor obtained above.
A double-sided adhesive tape (Nitto Denko, 5000NS) is applied to the peripheral edge of the PET film surface of the touch panel sensor obtained above, and the front polarizing plate of the liquid crystal display including the front polarizing plate and the PET film are bonded to each other. A touch panel was produced. In the obtained touch panel, an air layer surrounded by a double-sided adhesive tape exists between the liquid crystal display and the touch panel sensor.
The two conductive films were arranged such that the in-plane slow axis of the PET film in each conductive film and the transmission axis of the front polarizing plate were parallel (0 °).
Moreover, the touch panel sensor in the formed touch panel corresponds to the aspect in FIG.

<Example 5>
The same as Example 4 except that the in-plane slow axis of the PET film in the conductive film on the side close to the liquid crystal display in the two conductive films and the transmission axis of the front polarizing plate are orthogonal to each other. A touch panel was manufactured in accordance with the procedure described above.

<Comparative Example 1>
According to Example 1 of Patent Document 1, a uniaxially stretched polyethylene terephthalate film having a thickness of 46 μm was obtained. A touch panel was produced according to the same procedure as in Example 1 except that the PET film was used. The PET film used exhibited optical anisotropy, Nz was 1.0, and Re (550) was 1900 nm. nx was 1.681.

<Evaluation method>
(Detection position accuracy evaluation method)
The touch panel produced above was left in an environment of 85 ° C. and 85% for 240 hours, and then the detection position accuracy of the touch panel was evaluated. Specifically, a 5 mm square grid is displayed on the display panel of the liquid crystal display, and a finger is traced in parallel to the side in a region close to the edge of each side of the rectangular input region of the touch panel sensor. Evaluate the displacement (maximum value) of the touch position and the locus displayed on the screen, and calculate the displacement amount (maximum value) (mm) / electrode wiring length (mm) x 100 (%) on the four sides. The maximum value was taken as the position accuracy. The value was evaluated as A when the value was ± 2% or less, B when the value was more than ± 2% and ± 5% or less, and C when the value was ± 5% or more.
The electrode wiring length in the above formula is intended to be a length of 170 mm of the X detection electrode (length: 170 mm) when a region along the short side of the rectangular input region is traced with a finger. When the area along the long side of the input area is traced with a finger, the length of the Y detection electrode (length: 300 mm) is intended to be 300 mm.

(Rainbow unevenness evaluation)
Using the touch panel produced above, rainbow unevenness was evaluated. More specifically, as shown in FIG. 8, the angle between the touch panel plane and the observer's line of sight is the azimuth angle θ1, and the angle between the line perpendicular to the long side of the touch panel and the observer's line of sight is the polar The angle is θ2. The direction of the long side of the touch panel and the transmission axis of the front polarizing plate in the liquid crystal display are in a parallel relationship.
A rainbow when the observer's line of sight is shaken with a polar angle of ± 30 ° with the polar angle = 0 ° or 90 ° and the azimuth = 30-45 ° (fixed) at the center. The uneven coloring was confirmed and evaluated according to the following criteria.
When at least one of the rainbow unevenness evaluation at a polar angle = 0 ° (rainbow unevenness evaluation 0 °) and the rainbow unevenness evaluation at a polar angle = 90 ° (rainbow unevenness evaluation 90 °), the case where there is a score 4 is defined as “A”. At least one of the unevenness evaluation 0 ° and the rainbow unevenness evaluation 90 ° is evaluated as “B” when the score 3 is present, and the case where both the rainbow unevenness evaluation 0 ° and the rainbow unevenness evaluation 90 ° are equal to or less than the evaluation 2 is evaluated as “C”. did. In practice, “B” or more is preferable.
Score 1: Rainbow irregularities appear prominent with respect to changes in polar angle and azimuth angle.
Rating 2: Rainbow irregularities can be visually recognized with respect to changes in polar angle and azimuth angle, but coloring is lighter than 1.
Rating 3: Rainbow irregularities are visible, but within an acceptable range.
Score 4: Rainbow unevenness is not visually recognized.

(Refractive index measurement)
The refractive index (nx, ny, nx) of the PET film used in each example and comparative example was evaluated by an Abbe refractometer (Atago NAR-1T SOLID).

Table 1 below summarizes the evaluation results of the touch panels produced in the examples and comparative examples.
In Table 1, the “presence / absence” column of “protective substrate” indicates whether or not a protective substrate (HC-PET) showing optical anisotropy was used.
In Table 1, “Arrangement” indicates the relationship (orthogonal or parallel) between the in-plane slow axis of the substrate (PET film) or protective substrate and the vibration direction of linearly polarized light. “/” In Examples 4 and 5 indicates the arrangement of the substrates in the two conductive films used, respectively.

As shown in Table 1, in the touch panel of the present invention, it was confirmed that the occurrence of rainbow unevenness and the deterioration of position detection accuracy were suppressed.
On the other hand, in Comparative Example 1 in which the Nz of the substrate was 3.0 or less, deterioration in position detection accuracy was confirmed.

DESCRIPTION OF SYMBOLS 1 Touch panel 2 Image display panel 3,300,400,500 Touch panel sensor 4 Image display cell 5 Polarizing plate 6 Organic EL cell 7 1/4 wavelength plate 8 Circular polarizing plate 9 Organic EL panel 12 Substrate 14 First detection electrode 16 1st Lead wire 18 Second detection electrode 20 Second lead wire 30 Conductive thin wire 32 Grid 40 First transparent resin layer 42 Second transparent resin layer 50 First protective substrate 52 Second protective substrate 60 First substrate 62 Second substrate

Claims (7)

1. A touch panel having an image display panel that emits linearly polarized light, and a touch panel sensor disposed on a viewing side of the image display panel,
   The touch panel sensor includes at least a substrate exhibiting optical anisotropy,
   The substrate satisfies the relationship of the following formula (1),
   The vibration direction of linearly polarized light emitted from the image display panel and the in-plane slow axis of the substrate are arranged so as to be orthogonal or parallel,
   The touch panel having a maximum refractive index nx in the substrate plane of 1.60 or more.
   Formula (1): Nz> 3.0
   (Nz represents the Nz coefficient, the maximum refractive index in the substrate surface at a wavelength of 550 nm is nx, the refractive index at a wavelength of 550 nm in the direction orthogonal to nx in the substrate surface is ny, and the substrate thickness direction at a wavelength of 550 nm is (When the refractive index is nz, Nz = (nx−nz) / (nx−ny)).
2. The touch panel according to claim 1, wherein the nx is 1.61 to 1.70.
3. The touch panel according to claim 1, wherein Re (550) which is a retardation value of the substrate measured at a wavelength of 550 nm is 1000 to 3500 nm.
4. The touch panel according to any one of claims 1 to 3, wherein the substrate includes polyethylene terephthalate.
5. The touch panel according to any one of claims 1 to 4, wherein the detection electrode included in the touch panel sensor has a mesh pattern composed of a plurality of conductive thin wires intersecting each other.
6. The touch panel according to claim 5, wherein the conductive thin wire includes at least one selected from the group consisting of gold, silver, and copper.
7. A conductive film disposed on the viewing side of the image display panel that emits linearly polarized light,
   A substrate having optical anisotropy, and a conductive portion on at least one surface of the substrate,
   The substrate satisfies the relationship of the following formula (1),
   The electroconductive film whose maximum refractive index nx in the said substrate surface is 1.60 or more.
   Formula (1): Nz> 3.0
   (Nz represents the Nz coefficient, the maximum refractive index in the substrate surface at a wavelength of 550 nm is nx, the refractive index at a wavelength of 550 nm in the direction orthogonal to nx in the substrate surface is ny, and the substrate thickness direction at a wavelength of 550 nm is (When the refractive index is nz, Nz = (nx−nz) / (nx−ny)).
   
   

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