TW201505038A - Touch panel, conductive film - Google Patents

Abstract

The present invention provides a touch panel which can reduce generation of rainbow uneveness and shows little deterioration in position-detection accuracy even after a treatment at a high temperature and high humidity. The touch panel of the present invention has an image display panel that emits linearly polarized light and a touch panel sensor provided on the viewing side of the image display panel, wherein the touch panel sensor includes at least an optically anisotropic substrate which satisfies the following formula (1) and is configured such that the linearly polarized light emitted by the image display panel has a direction of vibration orthogonal or parallel to the in-plane slow axis of the substrate, and the maximum in-plane refractive index nx of the substrate is 1.60 or more. Formula (1): Nz > 3.0.

Description

Touch panel, conductive film

The present invention relates to a touch panel, and more particularly to a substrate that exhibits optical anisotropy included in a touch panel sensor, which exhibits a specific Nz coefficient and nx, while the in-plane slow axis of the substrate is displayed by an image. The vibration direction of the linearly polarized light emitted by the panel forms a specific relationship of the touch panel.

Further, the present invention relates to a conductive film used in the above touch panel.

In recent years, the mounting rate of touch panels in mobile phones and portable game devices has been increasing. For example, capacitive touch panels capable of detecting multiple points are attracting attention.

In order to improve the visibility of the touch panel, there is a method of using a transparent conductive film showing a specific Nz coefficient (refer to Japanese Laid-Open Patent Publication No. 2012-230491, hereinafter referred to as Patent Document 1). More specifically, it is disclosed that when a transparent conductive film having a transparent conductive layer on at least one surface of a flexible transparent substrate and having a Nz coefficient satisfying the relationship (ii) below is used, rainbow spots can be suppressed (rain)ムラ) is produced.

(ii) 0.8 ≤ Nz ≤ 1.4

In addition, in paragraph [0057] of the patent document 1, it is described that the flexible transparent substrate satisfies the above (ii) in order to satisfy the relationship (n) of Nz of the entire transparent conductive film. Full.

Further, as described in Patent Document 1, it is preferable to use a substrate such as PET which has been subjected to stretching and crystallization treatment as a flexible transparent substrate, which is excellent in mechanical properties, and these substrates have large in-plane and thickness directions. Birefringence. That is, the flexible transparent substrate exhibits optical anisotropy.

In recent years, in response to demands such as large-screening of touch panels, position detection is required with higher precision. On the other hand, the touch panel may be used in a use environment such as a warm place under high temperature and high humidity conditions, and may be exposed to high temperature and high humidity conditions in order to perform reliability test of the device, in which case Position detection accuracy (touch position detection accuracy) is also required to be high. In addition, from the viewpoint of improving the visibility of the touch panel, it is also required to reduce the generation of rainbow spots.

The inventors of the present invention have obtained the following knowledge: in the case where a touch panel is produced by using a transparent conductive film having a specific Nz coefficient described in Patent Document 1 and placed in a high-temperature and high-humidity environment, the generation of rainbow spots can be reduced. However, the position detection accuracy is degraded.

In view of the above circumstances, an object of the present invention is to provide a touch panel which can reduce the generation of rainbow spots and which is less likely to deteriorate in position detection accuracy even after high-temperature and high-humidity processing.

The present inventors conducted intensive studies on the above problems, and as a result, found that the in-plane slow axis of the substrate and the image display panel are simultaneously emitted by using a touch panel sensor including a substrate showing a specific Nz coefficient and nx. The arrangement of the vibration direction of the linearly polarized light has a specific relationship, and the above problem can be solved. That is, it was found that the above object can be achieved by the following constitution.

(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);

Formula (1): Nz>3.0;

Arranging in such a manner that the direction of vibration of the linearly polarized light emitted by the image display panel is orthogonal or parallel to the in-plane slow axis of the substrate;

The maximum refractive index nx in the plane of the substrate is 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 the retardation value Re (550) of the substrate measured at a wavelength of 550 nm is from 1000 nm to 3,500 nm.

The touch panel according to any one of (1) to (3) wherein the substrate comprises polyethylene terephthalate.

The touch panel according to any one of (1) to (4), wherein the sensing electrode included in the touch panel sensor has a mesh formed of two or more conductive thin wires that intersect each other. pattern.

(6) The touch panel according to (5), wherein the conductive thin wires comprise at least one selected from the group consisting of gold, silver, and copper.

(7) A conductive film which is disposed on a viewing side of an image display panel that emits linearly polarized light, wherein:

The conductive film includes a substrate exhibiting optical anisotropy and a conductive portion located on at least one surface of the substrate;

The substrate satisfies the relationship of the following formula (1);

Formula (1): Nz>3.0;

The maximum refractive index nx in the plane of the substrate is 1.60 or more.

The effect of the invention is:

The present invention can provide a touch panel which can reduce the generation of rainbow spots and which is less likely to deteriorate in position detection accuracy even after high-temperature and high-humidity processing.

The invention will be described in detail below. In addition, the numerical range represented by "-" in this specification is a range in which the numerical value described before and after "-" is included as a lower limit and an upper limit. First, the terms used in this specification will be explained.

Re(λ) each represents an in-plane retardation under the condition of wavelength λ. Re (λ) was measured by entering light of a wavelength λ nm in the normal direction of the film in KOBRA 21ADH or WR (manufactured by Oji Scientific Instruments Co., Ltd.). When the measurement wavelength λ nm is selected, the wavelength selection filter can be manually replaced or the measurement value can be converted by a program or the like. The details of the method for measuring Re(λ) are described in paragraphs 0010 to 0012 of JP-A-2013-041213, the contents of which are incorporated herein by reference.

In the present specification, when there is no special note on the measurement wavelength, the measurement wavelength is 550 nm.

Further, in the present specification, the angles (for example, "90°" and the like) and their relationships (for example, "orthogonal (orthogonal)", "parallel", etc.) include the allowable error range in the technical field to which the present invention pertains. In this case, the allowable error is, for example, a range of a strict angle of ±5° or less, and specifically, the error with the strict angle is preferably 3° or less. More specifically, orthogonal (orthogonal angle) means a range of 90 ° ± 5 °, and parallel means a range of 0 ° ± 5 °.

Hereinafter, a preferred mode of the touch panel (hereinafter also simply referred to as a touch panel) of the present invention will be described with reference to the drawings.

It should be noted that, as a feature of the touch panel of the present invention, as described above, a touch panel sensor including a substrate including a specific Nz coefficient (also referred to as Nz) and nx may be used, while making The arrangement of the in-plane slow axis of the substrate and the direction of vibration of the linearly polarized light emitted from the image display panel has a specific relationship. The present inventors have recognized that the high-temperature and high-humidity treatment of the touch panel produced by using the transparent conductive film described in Patent Document 1 is likely to cause deterioration in position detection accuracy, and the deformation of the flexible transparent substrate is very large. Great effect. In other words, the present inventors have recognized that since the flexible transparent substrate is deformed, the transparent conductive layer functioning as the sensing electrode is displaced, and as a result, the position detection accuracy is likely to deteriorate. In the following, the causes of the problems in the prior art will be described in more detail.

The inventors conducted intensive studies on the problems of the prior art, and as a result, found that the refractive index and the heat shrinkage showed a certain correlation. That is, the inventors have found that when the substrate exhibits a high refractive index in a specific direction, the heat shrinkability in this direction is reduced. In other words, it also corresponds to an increase in the heat shrinkability in this direction when the substrate exhibits a low refractive index in a specific direction.

The transparent conductive film used in Patent Document 1 exhibits 0.8 ≤ Nz ≤ 1.4, and Nz is relatively small. If Nz is considered to be "formula (X): Nz = (nx - nz) / (nx - ny)", in order for Nz to become smaller, the denominator (nx-ny) in equation (X) is required to be large, in other words, nx is required. The difference with ny becomes bigger. That is, it is required that the difference (refractive index difference) between nx and ny becomes large. In this case, the value of ny becomes small, and as a result, the heat shrinkability in this direction becomes large. In other words, when Nz is small, the heat shrinkability in the ny direction becomes relatively large, and the position of the sensing electrode included in the touch panel sensor is largely shifted due to thermal contraction of the substrate, and as a result, deterioration of position detection accuracy is liable to occur. .

On the other hand, in the present invention, the substrate used has a large Nz. In the case where Nz is large, the denominator (nx-ny) in the equation (X) is small, in other words, the difference between nx and ny becomes small. Further, it is required that the molecule (nx-nz) in the formula (X) is also large, and the nx itself is also relatively large. In this case, the value of ny is similar to nx, so the refractive index in the ny direction is large. In other words, since the heat shrinkability in this direction (y direction) becomes small, it is difficult to cause a positional shift of the sensing electrode, and as a result, deterioration in position detection accuracy is less likely to occur.

Further, in the present invention, it is difficult to generate a rainbow spot by satisfying a specific relationship between the in-plane slow axis of the substrate and the arrangement of the vibration directions of the linearly polarized light emitted from the image display panel. In addition, in the present specification, the observation of the rainbow spot means that the touch panel is observed while changing the azimuth angle by the direction orthogonal to or the same as the vibration direction of the linearly polarized light emitted from the image display panel (especially When the azimuth angle is observed from 30° to 60°, it is observed whether the rainbow spot is suppressed.

The first figure is a cross-sectional view of the touch panel of the present invention. It should be noted that the drawings in the present invention are schematic views, and the relationship of the thickness of each layer, the positional relationship, and the like are not necessarily consistent with the actual situation.

As shown in the first figure, the touch panel 1 has 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. It should be noted that the first figure is visually confirmed from the direction of the arrow. The image display panel 2 includes at least an image display unit 4 and a polarizing plate 5 on the viewing side.

It should be noted that, in the case that the touch panel 1 is a capacitive touch panel, if the finger approaches and contacts the touch panel sensor 3, the sensing electrode in the finger and the touch panel sensor 3 The electrostatic capacitance between them changes. Here, the position detection drive (not shown) constantly detects a change in electrostatic capacitance between the finger and the sensing electrode. When the position detection drive detects a change in electrostatic capacitance equal to or greater than a predetermined value, a position at which the change in electrostatic capacitance is detected is detected as an input position. Thus, the touch panel 1 can detect the input position.

Hereinafter, each component 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 unit 4 and a polarizing plate 5 (viewing side polarizing plate) on the viewing side.

As the image display unit 4, a liquid crystal cell, an organic EL unit, or the like is used.

As the liquid crystal cell, a transflective liquid crystal cell using external light, a transmissive liquid crystal cell using light from a light source such as a backlight, and a transflective liquid crystal cell using both external light and light from the light source can be used. Any of them. Further, as the driving method of the liquid crystal cell, any type of driving method such as a VA mode, an IPS mode, a TN mode, an STN mode, or a bend orientation (π type) can be used. In the case where a transmissive liquid crystal cell or a transflective liquid crystal cell is used as the liquid crystal cell, the image display panel may be provided with a light source side polarizing plate on the side opposite to the viewing side of the liquid crystal cell. With a light source. In this case, the polarized light state is converted during the transmission of the light from the light source in the liquid crystal cell, and the amount of light corresponding to the polarized light state is absorbed by the polarizing plate disposed on the viewing side of the liquid crystal cell, thereby adjusting the amount of transmitted light. Ability to display images. Therefore, the light emitted from the image display panel toward the viewing side is linearly polarized light having a vibration surface in the direction of the transmission axis of the polarizing plate 5.

As the organic EL unit, for example, an illuminant (organic electroluminescence illuminator) in which a transparent electrode, an organic luminescent 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, and 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 ruthenium, and such a light-emitting layer are known. A laminate of an electron injecting layer composed of a perylene derivative or the like, or a laminate of the hole injecting layer, the light emitting layer, and the electron injecting layer has various combinations. The organic EL panel can perform image display by adjusting the amount of light emitted from the organic EL unit itself, and thus the polarizing plate is not necessary in image display. However, since the thickness of the organic light-emitting layer is extremely thin, external light is reflected on the metal electrode and is again emitted toward the viewing side, and when viewed from the outside, the display surface of the organic EL display device may appear as a mirror surface. In order to shield the specular reflection of such external light, as shown in the second figure, a method of arranging a circular polarizing plate in which a polarizing plate 5 and a quarter-wavelength plate 7 are laminated on the viewing side of the organic EL unit 6 is employed. 8. 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 direction of the transmission axis of the polarizing plate 5 constituting the circularly polarizing plate 8.

As described above, with respect to the light emitted from the image display unit, the light in the absorption axis direction of the polarizing plate 5 is absorbed by the polarizing plate 5, and only the light in the direction of the transmission axis orthogonal to the absorption axis direction is directed to the touch panel sensor 3. The side is shot.

As the polarizing plate 5, a polarizing plate having a suitable absorption type linear polarizer is used. As such a polarizing plate, for example, a polarizing plate in which a polarizing plate composed of a polyvinyl alcohol-based stretched film containing iodine is sandwiched by a suitable transparent protective film is preferably used.

[Touch Panel Sensor]

The touch panel sensor 3 is disposed on the image display panel 2 (operator side), for example, to detect an external conductor such as a human finger by a change in electrostatic capacitance generated when an external conductor such as a human finger contacts (closes) The location of the sensor.

As the touch panel sensor 3, it is preferable to use a projection type capacitive touch panel sensor that detects a sensing electrode that is in contact with or close to a finger (especially The electrostatic capacitance of the sensing electrode extending in the X direction and the sensing electrode extending in the Y direction changes to determine the coordinates of the finger. As the touch panel sensor 3, for example, a touch panel sensor of a resistive film type can be used.

The structure of the touch panel sensor 3 is not particularly limited as long as it includes a substrate exhibiting optical anisotropy, and preferably includes at least a substrate having optical anisotropy and a sensing electrode disposed on at least one surface of the substrate. Conductive film. It should be noted that the sensing electrode constitutes a conductive portion in the conductive film.

As described above, the substrate exhibiting optical anisotropy means 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 will be described in detail with reference to the accompanying drawings. The touch panel sensor 3 includes at least a conductive film having a substrate exhibiting optical anisotropy and being disposed on a sensing electrode on at least one surface of the substrate. In addition, the substrate 12 shown in the third figure mentioned later is a board|substrate which shows optical anisotropy.

The third and fourth figures are diagrams showing an example of a capacitive touch panel sensor using a single conductive film. A top view of the touch panel sensor 300 is shown in the third figure. The fourth figure is a cross-sectional view taken along the cutting line A-A in the third figure. It should be noted that the third and fourth figures are diagrams schematically shown in order to make the understanding of the layer structure of the touch panel sensor easy, and the drawings do not accurately represent the configuration of the layers.

The touch panel sensor 300 includes a substrate 12, a first sensing electrode 14 disposed on one main surface (surface) of the substrate 12, a first lead wiring 16, a first transparent resin layer 40, and a first protective substrate. 50. The second sensing electrode 18, the second lead wiring 20, the second transparent resin layer 42, and the second protective substrate 52 are disposed on the other main surface (back surface) of the substrate 12. It should be noted that the region having the first sensing electrode 14 and the second sensing electrode 18 constitutes an input region E _I that can be input by the user, and is disposed in the outer region E _O outside the input region E _I . The first lead wiring 16, the second lead wiring 20, and a flexible printed circuit board (not shown). Further, the substrate 12, the first sensing electrode 14, and the second sensing electrode 18 constitute a conductive film.

The above structure will be described in detail below.

The substrate 12 by the following means, which bears the role of sensing a first sensing electrode in the input region E _I in said rear support 14 and the second sensing electrode 18, and charged with a first lead-out in the outer region E _O in said rear support The wiring 16 and the second lead wiring 20 function.

The substrate 12 satisfies the relationship of the following formula (1).

Formula (1): Nz>3.0

In particular, Nz is preferably 4.0 or more from the viewpoint that the deterioration of the position detection accuracy of the touch panel under high temperature and high humidity is further suppressed. The upper limit of Nz is not particularly limited, and is preferably 20 or less, and more preferably 10 or less from the viewpoint of preventing breakage due to stretching of the biaxially stretched film.

When the Nz is 3.0 or less, the position detection accuracy of the touch panel is likely to deteriorate.

In addition, Nz represents the Nz coefficient, and the maximum refractive index in the surface of the substrate at a wavelength of 550 nm is nx, and the refractive index in the direction orthogonal to nx at a wavelength of 550 nm is set to ny. When the refractive index in the thickness direction of the substrate at a wavelength of 550 nm is nz, Nz 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, and more preferably 1.65 or more from the viewpoint of further suppressing the occurrence of deterioration in the position detection accuracy of the touch panel. The upper limit is not particularly limited, and is usually more than 1.70.

The value of ny of the substrate 12 is not particularly limited as long as it satisfies the relationship of the above-described Nz coefficient, and the difference (nx-ny) from nx is preferably 0.05 or less, more preferably 0.03 or less. There is no particular limitation on the lower limit, and usually the difference (nx-ny) from nx 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 above-described Nz coefficient, and is preferably 1.55 or less, and more preferably 1.50 or less. The lower limit is not particularly limited, and is usually more than 1.45.

In addition, as the substrate satisfying the above Nz and nx, it is preferable to use a biaxially stretched substrate.

The in-plane slow axis of the substrate 12 is arranged to be orthogonal or parallel to the vibration direction of the linearly polarized light emitted from the image display panel 2, and is preferably orthogonal from the viewpoint of further suppressing the generation of rainbow spots. In the case where this is not the case, rainbow spots are further generated. The definitions of orthogonal and parallel are as described above.

In addition, the above aspect has the same meaning as the arrangement in which the in-plane slow axis of the substrate 12 and the transmission axis of the polarizing plate 5 (the viewing-side polarizing plate) in the image display panel 2 are orthogonal or parallel.

It should be noted that, 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 direction of vibration of the linearly polarized light are specified. If the touch panel sensor includes the optical other than the substrate 12 In the anisotropic substrate, similarly to the substrate 12, the specific Nz and nx, and the in-plane slow axis of the substrate and the vibration direction of the linearly polarized light satisfy a specific arrangement. More specifically, when the first protective substrate 50 or the second protective substrate 52 exhibits optical anisotropy, they also satisfy the above-described Nz and nx in the same manner as the substrate 12, and according to their faces. The inner slow axis is arranged in a manner orthogonal or parallel to the vibration direction of the linearly polarized light.

The retardation value Re (550) measured at a wavelength of 550 nm of the substrate 12 is not particularly limited, and is preferably from 1000 nm to 3,500 nm from the viewpoint of further suppressing generation of rainbow spots.

The substrate 12 preferably transmits light appropriately. Specifically, the total light transmittance of the substrate 12 is preferably 85% to 100%.

The substrate 12 is preferably insulating. That is, the substrate 12 is preferably a layer for ensuring insulation between the first sensing electrode 14 and the second sensing 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 them, an insulating resin substrate is preferred because of its excellent toughness.

More specifically, the material constituting the substrate 12 may be polyethylene terephthalate, polyether oxime, polyacrylic resin, urethane resin, polyester, polycarbonate, polyfluorene or polyfluorene. An amine, a polyarylate, a polyolefin, a cellulose resin, a polyvinyl chloride, a cycloolefin resin, or the like.

Among them, from the viewpoint of mechanical strength, dimensional stability, and heat resistance, it is preferred to use a substrate (polyester film) containing polyester as a main component. Examples of the polyester include a dicarboxylic acid (for example, terephthalic acid, isophthalic acid, phthalic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1, 4-naphthalenedicarboxylic acid, 1,5-naphthalene dicarboxylic acid, diphenylcarboxylic acid, diphenoxyethane dicarboxylic acid, diphenylphosphonium carboxylic acid, stilbene dicarboxylic acid, 1,3-cyclopentane Dicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, malonic acid, dimethylmalonic acid , succinic acid, 3,3-diethyl succinic acid, glutaric acid, 2,2-dimethylglutaric acid, adipic acid, 2-methyladipate, trimethyl adipate, Geng Acid, azelaic acid, dimer acid, sebacic acid, suberic acid, dodecane dicarboxylic acid, etc.) and diol (eg ethylene glycol, propylene glycol, hexamethylene glycol, neopentyl glycol, 1 , 2-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, decanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-six a homopolymer obtained by polycondensation of each of a diol, 2,2-bis(4-hydroxyphenyl)propane, bis(4-hydroxyphenyl)propane, or the like; or one or more dicarboxylic acids and two a copolymer obtained by polycondensation of the above diol; or A copolymer of two or more dicarboxylic acids with one or more kinds obtained by polycondensation of a diol; and any one of polyester resin or two or more of these homopolymers or copolymers obtained by blending the blended resin. Among them, from the viewpoint of the polyester exhibiting crystallinity, an aromatic polyester is preferable, and polyethylene terephthalate (PET) or polyethylene naphthalate (PEN) is particularly preferable, and polyparaphenylene is most preferable. Ethylene glycol dicarboxylate.

The polyester film is obtained, for example, by a method in which the polyester resin is melt-extruded onto a casting drum, and then cooled and solidified. In the case where a substrate containing an aromatic polyester as a main component is used as the substrate 12, the substrate 12 may contain a resin other than an aromatic polyester, an additive, or the like. The "aromatic polyester as a main component" means an aromatic polyester having 50% by weight or more, preferably 60% by weight or more, more preferably 70% or more, and still more preferably 80% or more, based on the total weight of the substrate 12. .

In addition, from the viewpoint of imparting crystallinity to the polyester film to achieve the above characteristics, a biaxially oriented polyester film can be preferably used as the substrate.

In the third and fourth figures, the substrate 12 is a single layer, but may be a multilayer of two or more layers.

The thickness of the substrate 12 (the total thickness of the substrate 12 when two or more layers are used) is not particularly limited, but is preferably 5 μm to 350 μm, and more preferably 30 μm to 150 μm. When it is in the above range, a desired visible light transmittance can be obtained, and handling is also easy.

Further, in the third and fourth figures, the shape of the plan view of the substrate 12 is substantially rectangular, but is not limited thereto. For example, it may be a circle or a polygon.

The first sensing electrode 14 and the second sensing electrode 18 are sensing electrodes that sense changes in electrostatic capacitance, and constitute a sensing unit (sensor portion). In other words, when the fingertip comes into contact with the touch panel, the mutual capacitance between the first sensing electrode 14 and the second sensing electrode 18 changes, and based on the amount of change, the position of the fingertip is calculated by the IC circuit.

The first sensing electrode 14 has a function of detecting an input position in the X direction of the user's finger approaching the input region E _I , and has a function of generating an electrostatic capacitance with the finger. The first sensing electrode 14 is an electrode that extends in the first direction (X direction) and is arranged at a specific interval in the second direction (Y direction) orthogonal to the first direction, and includes a specific pattern as will be described later.

The second sensing electrode 18 has a function of detecting an input position in the Y direction of the user's finger approaching the input region E _I , and has a function of generating an electrostatic capacitance with the finger. The second sensing electrode 18 is an electrode that extends in the second direction (Y direction) and is arranged at a specific interval in the first direction (X direction), and includes a specific pattern as will be described later. In the third figure, five first sensing electrodes 14 are provided, and five second sensing electrodes 18 are provided. However, the number of the second sensing electrodes 18 is not particularly limited, and may be two or more.

In the third diagram, the first sensing electrode 14 and the second sensing electrode 18 may be formed of, for example, conductive thin wires. The enlarged view of a part of the first sensing electrode 14 is shown in the fifth figure. As shown in FIG. 5, the first sensing electrode 14 is composed of a conductive thin wire 30 and includes a plurality of lattices 32 formed by intersecting conductive thin wires 30. In other words, the first sensing electrode 14 has a mesh pattern composed of two or more conductive thin wires that intersect. In addition, the second sensing electrode 18 also includes a plurality of lattices 32 formed of intersecting conductive thin wires 30 similarly to the first sensing electrodes 14 .

Examples of the material of the conductive thin wires 30 include metals or alloys such as gold (Au), silver (Ag), copper (Cu), and aluminum (Al); ITO, tin oxide, zinc oxide, cadmium oxide, gallium oxide, and the like. Metal oxides such as titanium dioxide; and the like. Among them, silver is preferable because of the excellent conductivity of the conductive thin wires 30.

The conductive fine wire 30 preferably contains a binder from the viewpoint of adhesion between the conductive thin wires 30 and the substrate 12.

The binder is preferably a water-soluble polymer because the adhesion between the conductive fine wires 30 and the substrate 12 is more excellent. Examples of the type of the binder include polysaccharides such as gelatin, carrageenan, polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), and starch, cellulose and derivatives thereof, polyethylene oxide, and polysaccharide. Polyvinylamine, chitosan, polylysine, polyacrylic acid, polyalginic acid, polyhyaluronic acid, carboxy cellulose, gum arabic, sodium alginate, and the like. Among them, gelatin is preferred because the adhesion between the conductive thin wires 30 and the substrate 12 is more excellent.

It should be noted that, as gelatin, in addition to lime treatment gelatin, acid-treated gelatin may be used, and hydrolyzate of gelatin, gelatinase decomposition product, gelatin modified with amino group or carboxyl group (phthalic acid gelatin, acetamidine) may be used. Gelatin).

The volume ratio of the metal to the binder in the conductive fine wires 30 (the volume of the metal / the volume of the binder) is preferably 1.0 or more, and more preferably 1.5 or more. When the volume ratio of the metal to the binder is 1.0 or more, the conductivity of the conductive thin wires 30 can be further improved. The upper limit is not particularly limited, and is preferably 4.0 or less, and more preferably 2.5 or less from the viewpoint of productivity.

It should be noted that the volume ratio of the metal to the binder can be calculated by using the density of the metal and the binder contained in the conductive fine wire 30. For example, when the metal is silver, the density of silver is set to 10.5 g/cm ³ , and when the binder is gelatin, the density of gelatin is set to 1.34 g/cm ³ , thereby calculating the above. Volume ratio.

The line width of the conductive thin wires 30 is not particularly limited, and is preferably 30 μm or less, more preferably 15 μm or less, further preferably 10 μm or less, particularly preferably 9 μm or less, and most preferably from the viewpoint of easily forming an electrode having a low electrical resistance. It is preferably 7 μm or less, preferably 0.5 μm or more, and more preferably 1.0 μm or more.

The thickness of the conductive thin wire 30 is not particularly limited, and may be selected from 0.00001 mm to 0.2 mm, preferably 30 μm or less, more preferably 20 μm or less, further preferably 0.01 μm to 9 μm, and most preferably from the viewpoint of conductivity and visibility. It is preferably 0.05 μm to 5 μm.

The lattice 32 includes an open area surrounded by the conductive thin wires 30. The length W of one side of the lattice 32 is preferably 800 μm or less, more preferably 600 μm or less, or preferably 50 μm or more, and more preferably 400 μm or more.

In the first sensing electrode 14 and the second sensing 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. The aperture ratio corresponds to a ratio of a transmissive portion other than the conductive thin wires 30 in the first sensing electrode 14 or the second sensing electrode 18 in a specific region.

The lattice 32 has an approximately diamond shape. However, in addition to this, it may be a polygon (for example, a triangle, a quadrangle, a hexagon, a random polygon). Further, the shape of one side may be linear, or may be a curved shape or an arc shape. In the case of an arc shape, for example, the two opposite sides may be formed in an arc shape convex outward, and the other two opposite sides may be formed in an arc shape convex inward. Further, the shape of each side may be a wavy line shape in which an arc convex toward the outside and a circular arc convex toward the inside are continuous. Of course, the shape of each side can also be sinusoidal.

In the fifth drawing, the conductive thin wires 30 are formed in the form of a mesh pattern. However, the present invention is not limited to this embodiment, and may be a stripe pattern.

In the third diagram, the first sensing electrode 14 and the second sensing electrode 18 are formed of a mesh structure of the conductive thin wires 30. However, the present invention is not limited to this embodiment, and may be, for example, ITO or tin oxide. A transparent metal oxide film such as zinc oxide, cadmium oxide, gallium oxide or titanium dioxide. Further, the first sensing electrode 14 and the second sensing electrode 18 may be formed of a metal paste such as a metal oxide, a silver paste or a copper paste, or a metal nanowire such as a silver nanowire or a copper nanowire. Among them, silver nanowires are preferred from the viewpoint of excellent conductivity and transparency.

Further, the patterning of the electrode portion can be selected depending on the material of the electrode portion, and a photolithography method, a resist mask screen printing-etching method, an inkjet method, a printing method, or the like can be used.

Each of the first lead line 16 and the second lead line 20 is a member for supporting a voltage applied to the first sensing electrode 14 and the second sensing electrode 18, respectively.

The first lead wiring 16 is disposed on the substrate 12 of the outer region E _O , and one end thereof is electrically connected to the corresponding first sensing electrode 14 and the other end is located in the external conductive region G _{I where a} flexible printed circuit board or the like is disposed.

The second lead-out wiring 20 is disposed on the substrate 12 of the outer region E _O , and one end thereof is electrically connected to the corresponding second sensing electrode 18 , and the other end is located in an external conductive region G _I in which a flexible printed circuit board or the like is disposed.

In the third diagram, five first lead wires 16 are described, and two second lead wires 20 are described. However, the number of the first lead wires 16 is not particularly limited, and two types of sensing electrodes are usually arranged. the above.

Examples of the material constituting the wiring of the first lead wiring 16 and the second lead wiring 20 include metals such as gold (Au), silver (Ag), and copper (Cu); tin oxide, zinc oxide, cadmium oxide, and gallium oxide. , metal oxides such as titanium dioxide, and the like. Among them, silver is preferable because of its excellent electrical conductivity. Further, it may be composed of a metal paste such as a silver paste or a copper paste, or a metal such as aluminum (Al), molybdenum (Mo), or palladium (Pd) or an alloy thin film. In the case of a metal paste, screen printing or inkjet printing is preferably used. In the case of a metal or alloy thin film, it is preferable to use a patterning method such as photolithography for the sputtered film.

In addition, it is preferable that the first lead wiring 16 and the second lead wiring 20 contain a binder from the viewpoint of being more excellent in adhesion to the substrate 12 . The type of binder is as described above.

The first transparent resin layer 40 and the second transparent resin layer 42 are disposed on the first sensing electrode 14 on the input region E _I and the second sensing electrode 18, respectively, for securing the first sensing electrode 14 and the first A layer (particularly an adhesive transparent resin layer) that protects the substrate 50 and the adhesion between the second sensing 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 μm to 350 μm, and more preferably 20 μm to 150 μm. When it is in the above range, a desired visible light transmittance can be obtained, and handling is also 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 first transparent resin layer 40 and the second transparent resin layer 42 generally exhibit optical isotropy.

As a material constituting the first transparent resin layer 40 and the second transparent resin layer 42, a known adhesive is preferably used, and examples thereof include a rubber-based pressure-sensitive adhesive, an acrylic pressure-sensitive adhesive, and an anthrone-based pressure-sensitive adhesive. Among them, an acrylic pressure-sensitive adhesive is preferred from the viewpoint of excellent transparency.

The acrylic adhesive which is a preferable aspect of the above-mentioned adhesive agent has an acrylic polymer having a repeating unit derived from an alkyl (meth)acrylate as a main component. It should be noted that (meth) acrylate means acrylate and/or methacrylate. In the acrylic pressure-sensitive adhesive, an acrylic polymer having a repeating unit of an alkyl (meth)acrylate having an alkyl group having about 1 to 12 carbon atoms is preferable, from the viewpoint of further excellent adhesion. It is preferably an acrylic polymer having an alkyl methacrylate repeating unit derived from the above carbon atoms and an alkyl acrylate repeating unit derived from the above carbon atoms.

In the repeating unit in the above acrylic polymer, a repeating unit derived from (meth)acrylic acid may be contained.

Each of the first protective substrate 50 and the second protective substrate 52 is a substrate disposed on the first transparent resin layer 40 and the second transparent resin layer 42 , and protects the first sensing electrode 14 and the second sensing electrode 18 from external In the substrate for environmental damage, usually, 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. The thickness of the layers is desirably selected as appropriate for the respective application.

As a raw material of the above plastic film and plastic sheet, polyesters such as polyethylene terephthalate (PET) or polyethylene naphthalate (PEN); polyethylene (PE) and polypropylene can be used. Polyolefins such as (PP), polystyrene, EVA; vinyl resins; and polycarbonate (PC), polyamides, polyimine, acrylics, triethylene cellulose (TAC), rings An olefin resin (COP) or the like.

In addition, as the first protective substrate 50 and the second protective substrate 52, it is preferable to use a substrate exhibiting optical isotropy from the viewpoint of excellent mechanical strength, and a substrate exhibiting 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 formed in the same manner as the substrate 12 in 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 is orthogonal or parallel to the vibration direction of the linearly polarized light emitted from the image display panel. The first protective substrate 50 is placed in a manner. When the second protective substrate 52 exhibits optical anisotropy, the in-plane slow axis of the second protective substrate 52 and the linearly polarized light emitted from the image display panel are similar to those of the first protective substrate 50. The second protective substrate 52 is disposed such that the vibration direction is orthogonal or parallel.

Further, when the first protective substrate 50 and/or the second protective substrate 52 exhibit optical anisotropy, Nz and nx of the respective substrates show the same range as the substrate 12. More specifically, when the first protective substrate 50 exhibits optical anisotropy, the first protective substrate 50 satisfies the above formula (1): Nz>3.0, and nx is 1.6 or more. 12 is the same. When the second protective substrate 52 exhibits optical anisotropy, the second protective substrate 52 satisfies the above formula (1): Nz>3.0, and nx is 1.6 or more. The preferred embodiment is the same as the substrate 12.

In addition, the second transparent resin layer 42 may be directly brought into contact with the image display panel 2 without using the second protective substrate 52 described above.

Further, 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 making the substrate have a hardness to prevent the occurrence of scratches.

Examples of the resin for forming the hard coat layer include a thermosetting resin, a thermoplastic resin, an ultraviolet curable resin, an electron beam curable resin, and a two-liquid mixing resin. Among them, it is preferable to be capable of curing by ultraviolet irradiation. The ultraviolet curable resin of the hard coat layer is effectively formed by a simple processing operation. Examples of the ultraviolet curable resin include various ultraviolet curable resins such as polyester, acrylic, urethane, guanamine, ketone, and epoxy, including ultraviolet curable monomers and oligomerization. Materials, polymers, etc. The ultraviolet curable resin to be preferably used is, for example, an ultraviolet curable resin having an ultraviolet polymerizable functional group, and particularly an acrylic monomer or oligomer component having two or more, particularly three to six, functional groups. UV curable resin. Further, an ultraviolet polymerization initiator is blended in the ultraviolet curable resin.

The method of forming the hard coat layer is not particularly limited, and a suitable method can be employed.

A flexible printed circuit board (not shown) is disposed in the external conduction region G _{I of the} third diagram. The flexible printed circuit board is a board in which a plurality of wirings and terminals are provided on a substrate, and is connected to each other end of the first lead wiring 16 and the other end of the second lead wiring 20 to function as a touch panel sensor. The role of 300 in connection with an external device, such as an image display panel.

[Manufacturing method of touch panel sensor]

The method of manufacturing the touch panel sensor 300 is not particularly limited, and a known method can be employed. First, as a method of manufacturing the sensing electrode and the lead wiring, a method of exposing and developing a photoresist film formed on a metal foil formed on both main surfaces of the substrate 12 to form a resist pattern is exemplified. The metal foil exposed from the resist pattern is etched. Further, a method of printing a paste containing metal fine particles or metal nanowires on both main surfaces of the substrate 12 and subjecting the paste to metal plating may be mentioned. Further, a method of forming on the substrate 12 by using a screen printing plate or a gravure printing plate, or a method of forming by inkjet can also be mentioned.

Further, in addition to the above methods, a method using silver halide can be mentioned. More specifically, first, as a method of forming the first sensing electrode 14 and the first lead wiring 16 and the second sensing electrode 18 and the second lead wiring 20 on the substrate 12, silver halide may be used. method. More specifically, a method having the following steps: step (1), forming a silver halide emulsion layer containing silver halide and gelatin (hereinafter also referred to simply as a photosensitive layer) on both surfaces of the substrate 12; 2) After the photosensitive layer is exposed, development processing is performed to form the first sensing electrode 14 and the first lead wiring 16, and the second sensing electrode 18 and the second lead wiring 20.

Hereinafter, each step will be described.

[Step (1): Photosensitive layer forming step]

The step (1) is a step of forming a photosensitive layer containing silver halide and gelatin on both surfaces of the substrate 12.

The method of forming the photosensitive layer is not particularly limited, and from the viewpoint of productivity, it is preferred that the photosensitive layer-forming composition containing silver halide and a binder is brought into contact with the substrate 12 to form a photosensitive layer on both surfaces of the substrate 12. method.

Hereinafter, the method of the composition for forming a photosensitive layer used in the above method will be described in detail, and the procedure of the step will be described in detail.

The composition for forming a photosensitive layer contains silver halide and gelatin.

The halogen element contained in the silver halide may be any one of chlorine, bromine, iodine and fluorine, or may be combined. As the silver halide, for example, silver halide mainly composed of silver chloride, silver bromide or silver iodide is preferably used, and silver halide mainly composed of silver bromide or silver chloride is more preferably used.

The type of gelatin is as described above.

The volume ratio of the silver halide to the gelatin contained in the photosensitive layer-forming composition is not particularly limited, and is appropriately adjusted so as to reach a range of a preferable volume ratio of the metal to the binder in the conductive fine wire 30.

The photosensitive layer-forming composition contains a solvent as needed.

Examples of the solvent to be used include water and an organic solvent (for example, an alcohol such as methanol, a ketone such as acetone, a guanamine such as formamide, an anthracene such as dimethyl hydrazine, or an ester such as ethyl acetate. A class, an ether, etc.), an ionic liquid, or a mixed solvent thereof.

The content of the solvent to be used is not particularly limited, and is preferably in the range of 30 to 90% by mass, and more preferably in the range of 50 to 80% by mass, based on the total mass of the silver halide and the binder.

[Steps of the process]

The method of bringing the composition for forming a photosensitive layer into contact with the substrate 12 is not particularly limited, and a known method can be employed. For example, a method of applying the composition for forming a photosensitive layer to the substrate 12, a method of immersing the substrate 12 in the composition for forming a photosensitive layer, and the like can be given.

The content of the silver halide in the photosensitive layer is not particularly limited, and is preferably 1.0 to 20.0 g/m ² , and more preferably 5.0 to 15.0 g/m ² in terms of silver, from the viewpoint of further excellent conductivity.

It is to be noted that a protective layer composed of an adhesive may be further provided on the photosensitive layer as needed. Anti-scratch and mechanical properties can be improved by providing a protective layer.

[Process (2): Exposure and development process]

In the step (2), the photosensitive layer pattern obtained in the step (1) is exposed, and then development processing is performed to form the first sensing electrode 14 and the first lead wiring 16, and the second sensing electrode 18 and the second The process of drawing out the wiring 20.

Hereinafter, the pattern exposure processing will be described in detail, and then the development processing will be described in detail.

[pattern exposure]

The silver halide in the photosensitive layer in the exposed region forms a latent image by performing pattern exposure on the photosensitive layer. The region in which the latent image is formed forms the first sensing electrode 14 and the first lead wiring 16, and the second sensing electrode 18 and the second lead wiring 20 by development processing to be described later. On the other hand, in the unexposed area where the exposure is not performed, silver halide dissolves and flows out of the photosensitive layer in the fixing process to be described later, and a transparent film is obtained.

The light source used for the exposure is not particularly limited, and examples thereof include visible light, ultraviolet light, and the like; or radiation such as X-rays.

The method of performing pattern exposure is not particularly limited, and for example, it may be performed by surface exposure using a photomask, or by scanning exposure using a laser beam. It should be noted that the shape of the pattern is not particularly limited, and the pattern of the conductive thin wires to be formed is adjusted as appropriate.

[development processing]

The method of the development treatment is not particularly limited, and a known method can be employed. For example, a technique of usual development processing used in silver salt photographic film, printing paper, film for printing plate, emulsion mask for photomask, or the like can be used.

The type of the developer to be used in the development treatment is not particularly limited, and for example, a PQ developer, an MQ developer, a MAA developer or the like can be used.

The development processing may include a fixing treatment for the purpose of stabilizing the silver salt of the unexposed portion to stabilize it. As the fixing treatment, a technique of fixing treatment used in silver salt photographic film or printing paper, printing plate making film, emulsion mask for photomask, or the like can be used.

The fixing temperature in the fixing step is preferably from about 20 ° C to about 50 ° C, and more preferably from 25 ° C to 45 ° C. Further, the fixing time is preferably 5 seconds to 1 minute, and more preferably 7 seconds to 50 seconds.

The quality of the metallic silver contained in the exposed portion (conductive thin wire) after the development treatment is preferably 50% by mass or more, and more preferably 80% by mass or more, based on the mass of silver contained in the exposed portion before exposure. When the quality of the silver contained in the exposed portion is 50% by mass or more based on the quality of the silver contained in the exposed portion before the exposure, high conductivity can be obtained, which is preferable.

The method of forming the first transparent resin layer 40 and the second transparent resin layer 42 is not particularly limited, and a method of bonding a known transparent resin film or a composition for forming a transparent resin layer forming transparent resin layer to form a layer is exemplified. Method etc.

The method of forming the first protective substrate 50 and the second protective substrate 52 is not particularly limited, and a method of bonding the protective substrate to each of the first transparent resin layer 40 and the second transparent resin layer 42 is exemplified.

Although the method of arranging the first sensing electrode and the second sensing electrode on the front and back surfaces of the substrate has been described in detail above, the touch panel sensor is not limited to this embodiment.

In the following, other ways of the touch panel sensor will be described in detail.

FIG. 6 is a cross-sectional view showing a part of a second embodiment of the touch panel sensor.

As shown in FIG. 6 , the touch panel sensor 400 includes a second substrate 62 , a second sensing electrode 18 disposed on the second substrate 62 , and is electrically connected to one end of the second sensing electrode 18 . The second lead wiring (not shown) on the second substrate 62, the second transparent resin layer 42, the first sensing electrode 14, and the first lead wiring 16 electrically connected to one end of the first sensing electrode 14 (not The first sensing electrode 14 and the first lead-out wiring 16 are adjacent to each other, the first substrate 60, the first transparent resin layer 40, and the first protective substrate 50.

The touch panel sensor 400 shown in FIG. 6 has the same layer as the touch panel sensor 300 shown in FIG. 3 except that the order of the layers is different, and thus the same structural elements are attached. The same reference numerals are used, and the description thereof is omitted. In addition, the first substrate 60 and the second substrate 62 are the same layers as the substrate 12 shown in the third figure, and both exhibit optical anisotropy, and the definition thereof is as described above.

Further, the first sensing electrode 14 and the second sensing electrode 18 in the sixth diagram are respectively used in two or more as shown in the third figure, and as shown in the third figure, the two are arranged orthogonally to each other.

It should be noted that the touch panel sensor 400 shown in FIG. 6 corresponds to a touch panel in which two electrode substrates (conductive films) having a substrate and sensing electrodes and lead wires disposed on the surface of the substrate are prepared. The touch panel is obtained by bonding the transparent electrodes along the sensing electrodes so as to face each other.

In the case of the above-described aspect, the in-plane slow axis of the first substrate 60 included in the touch panel sensor 400 and the in-plane slow axis of the second substrate 62 and the linearly polarized light emitted from the respective image display panels are used. The vibration directions are arranged in an orthogonal or parallel manner.

Further, both the first substrate 60 and the second substrate 62 satisfy the above formula (1) and show a specific nx.

In the following, other ways of the touch panel sensor will be described in detail.

FIG. 7 is a cross-sectional view showing a part of a third embodiment of the touch panel sensor. As shown in FIG. 7 , the touch panel sensor 500 includes a second substrate 62 , a second sensing electrode 18 disposed on the second substrate 62 , and is electrically connected to one end of the second sensing electrode 18 . The second lead-out wiring (not shown) on the second substrate 62, the second transparent resin layer 42, the first substrate 60, the first sensing electrode 14 disposed on the first substrate 60, and the first sensing One end of the electrode 14 is electrically connected to the first lead wiring (not shown) on the first substrate 60, the first transparent resin layer 40, and the first protective substrate 50.

The touch panel sensor 500 shown in FIG. 7 has the same layer as the touch panel sensor 400 shown in FIG. 6 except that the order of the layers is different, and thus the same structural elements are attached. The same reference numerals are used, and the description thereof is omitted.

Further, the first sensing electrode 14 and the second sensing electrode 18 in the seventh diagram are respectively used in two or more as shown in the third figure, and as shown in the third figure, the two are arranged orthogonally to each other.

It should be noted that the touch panel sensor 500 shown in FIG. 7 is equivalent to the following touch panel: preparing two electrodes with a substrate and sensing electrodes and lead wires disposed on the surface of the substrate (conductive film) The touch panel is obtained by laminating a transparent resin layer so that the substrate in one of the electrode substrates faces the electrode of the other electrode substrate.

In the case of the above-described aspect, the in-plane slow axis of the first substrate 60 included in the touch panel sensor 500 and the in-plane slow axis of the second substrate 62 and the linearly polarized light emitted from each image display panel are used. The vibration directions are arranged in an orthogonal or parallel manner.

Further, both the first substrate 60 and the second substrate 62 satisfy the above formula (1) and show a specific nx.

An adhesive layer may be disposed between the image display panel and the touch panel sensor as needed. As the adhesive in the adhesive layer to be used, an adhesive having transparency is preferable, and specifically, for example, an acrylic polymer, an anthrone polymer, a polyester, a polyurethane, a polyamide may be selected as appropriate. A polymer such as a polyvinyl ether, a vinyl acetate/vinyl chloride copolymer, a modified polyolefin, an epoxy-based, a fluorine-based, a natural rubber, or a synthetic rubber is used as an adhesive for a base polymer. In particular, an acrylic pressure-sensitive adhesive is preferably used because it is excellent in optical transparency, exhibits excellent wettability, adhesion properties such as cohesiveness and adhesion, and weather resistance and heat resistance.

Example

Hereinafter, the present invention will be described in more detail by way of examples, but the invention is not limited thereto.

<Example 1>

(Preparation of silver halide emulsion)

For the following 1 liquid which was kept at 38 ° C and pH 4.5, the following two liquids and three liquids were added in an amount equivalent to 90% for 20 minutes while stirring, to form core particles of 0.16 μm. Next, the following four liquids and five liquids were added over 8 minutes, and the remaining 10% of the following two liquids and three liquids were further added over 2 minutes to grow to 0.21 μm. Further, 0.15 g of potassium iodide was added and aged for 5 minutes to terminate the formation of particles.

1 liquid:

Water 750ml

Gelatin 9g

Sodium chloride 3g

1,3-dimethylimidazolidin-2-thione 20mg

Sodium phenylthiosulfonate 10mg

Citric acid 0.7g

2 liquid:

Water 300ml

Silver nitrate 150g

3 liquid:

Water 300ml

Sodium chloride 38g

Potassium bromide 32g

Potassium hexachloroantimonate (III)

(0.005% KCl 20% aqueous solution) 8ml

Ammonium hexachloroantimonate

(0.001% NaCl 20% aqueous solution) 10ml

4 liquid:

Water 100ml

Silver nitrate 50g

5 liquid:

Water 100ml

Sodium chloride 13g

Potassium bromide 11g

Yellow blood salt 5mg

Thereafter, water washing is carried out by a flocculation method according to a conventional method. Specifically, the temperature was lowered to 35 ° C, and the pH was lowered to a position where the silver halide was precipitated by using sulfuric acid (in the range of pH 3.6 ± 0.2). Next, about 3 liters of the supernatant (first water wash) was removed. Further, 3 liters of distilled water was added, and then sulfuric acid was added until the silver halide settled. Remove 3 liters of supernatant (second water wash) again. Further, the same operation as the second water washing (third water washing) was repeated once, and the water washing and desalting step was terminated. The emulsion after washing and desalting was adjusted to pH 6.4 and pAg7.5, and 3.9 g of gelatin, 10 mg of sodium thiosulfonate, 3 mg of sodium phenylsulfinate, 15 mg of sodium thiosulfate, and 10 mg of chloroauric acid were added. Chemical sensitization was carried out at 55 ° C to obtain the best sensitivity, and 100 mg of 1,3,3a,7-tetrazine dyed as a stabilizer, PROXEL (trade name, manufactured by ICI Co., Ltd.) as a preservative was added. 100mg. The finally obtained emulsion was a silver iodide bromide cube containing 0.08 mol% of silver iodide, a ratio of silver chlorobromide of 70 mol% of silver chloride, 30 mol% of silver bromide, an average particle diameter of 0.22 μm, and a coefficient of variation of 9%. Granular emulsion.

[Preparation of Composition for Photosensitive Layer Formation]

To the above emulsion, 1,3,3a,7-tetraazaindene 1.2 × 10 ^-4 mol / mol of Ag, hydroquinone 1.2 × 10 ^-2 mol / mol of Ag, and citric acid 3.0 × 10 ^-4 mol / mol of Ag are added. 2,4-Dichloro-6-hydroxy-1,3,5-triazine sodium salt 0.90 g/mol Ag, and the pH of the coating liquid was adjusted to 5.6 with citric acid to obtain a photosensitive layer-forming composition.

[Photosensitive layer forming process]

After performing a corona discharge treatment on a polyethylene terephthalate (PET) film having a thickness of 99.8 μm, a gelatin layer having a thickness of 0.1 μm as an undercoat layer was provided on both surfaces of the PET film, and on the undercoat layer. An antihalation layer comprising a dye having an optical density of about 1.0 and which is decolorizable by the alkali of the developer. The photosensitive layer-forming composition was applied onto the antihalation layer, and a gelatin layer having a thickness of 0.15 μm was further provided to obtain a PET film having a photosensitive layer formed on both surfaces thereof. The obtained film was referred to as film A. The photosensitive layer formed had a silver content of 6.0 g/m ² and a gelatin content of 1.0 g/m ² .

Further, 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.

[Exposure development process]

The touch panel sensor pattern (first sensing electrode and second sensing electrode) and the lead wiring portion (first lead wiring and second lead) shown in FIG. 3 are disposed on both surfaces of the film A The photomask of the wiring is exposed by parallel light using a high pressure mercury lamp as a light source. After the exposure, development was carried out by the following developer, and development treatment was carried out using a fixing solution (trade name: N3X-R for CN16X, manufactured by Fujifilm Co., Ltd.). Further, it was rinsed with pure water and dried to obtain a PET film having a sensing electrode and a gelatin layer formed on both sides, the sensing electrode having a mesh pattern composed of Ag fine lines. The gelatin layer is formed between the fine lines of Ag. The obtained film was referred to as film B.

In addition, the first sensing electrode disposed on the PET film is an electrode extending in the X direction, the second sensing electrode is an electrode extending in the Y direction, and the X sensing electrode (length: 170 mm) is 32. Y sensing electrodes (length: 300 mm) were 56 pieces.

[Composition of developer]

The following compound was contained in 1 liter (L) of the developer.

Hydroquinone 0.037mol/L

N-methylaminophenol 0.016mol/L

Sodium metaborate 0.140mol/L

Sodium hydroxide 0.360mol/L

Sodium bromide 0.031mol/L

Potassium metabisulfite 0.187mol/L

Using the film B obtained above, a touch panel was manufactured by the following method.

A laminate of OCA (#8146-4: 100 μm thick) manufactured by 3M Co., Ltd. was bonded to one surface (top surface) of the film B obtained above. In addition, the OCA located at each of the other ends of the first lead-out wiring portion and the second lead-out wiring portion corresponding to the FPC (flexible printed circuit board) crimping portion is opened in advance, and the FPC can be pressure-bonded.

For the laminate (film B+OCA), the outer shape was adjusted to the same size as the 0.7 mm thick soda lime glass of the approximate sensor size, and the FPC was crimp bonded by ACF (CP906AM-25AC) manufactured by Sony Chemical Co., Ltd. Thereafter, the above-mentioned soda lime glass was attached to the top side to fabricate a touch panel sensor.

Using the touch panel sensor obtained above, a touch panel was fabricated by the following method.

The OCR (HRJ-21) manufactured by Kyoritsu Chemical Co., Ltd., which is placed on the surface of the touch panel sensor (bottom surface opposite to the surface having soda lime glass) obtained by the dispenser described above to reach a final thickness of 300 μm. After bonding with a liquid crystal display panel including a front polarizing plate, the touch panel is fabricated by ultraviolet curing.

It should be noted that the film B is disposed such that the in-plane slow axis of the PET film in the film B is parallel (0°) to the transmission axis of the front polarizing plate of the liquid crystal display.

In addition, the touch panel sensor in the formed touch panel corresponds to a mode in which the second protective substrate 52 in the third figure is not present.

<Example 2>

Using the film B manufactured in Example 1, a touch panel was manufactured by the following method.

On one surface (bottom surface) of the film B obtained above, OCA (#8146-4: 100 μm thick) manufactured by 3M Co., Ltd. and hard coating film (G1SBF: 50 μm thick) manufactured by KIMOTO Co., Ltd. were laminated in this order (hereinafter also Called HC-PET). Further, a laminate of OCA (#8146-4: 100 μm thick) manufactured by 3M Co., Ltd. was bonded to the other surface (top surface) of the film B. In addition, the OCA and the hard coat film on each of the other ends of the first lead-out wiring portion and the second lead-out wiring portion corresponding to the FPC crimping portion are opened in advance, and the FPC can be pressure-bonded.

With respect to the laminate obtained above, the outer shape was adjusted to the same size as the soda lime glass having a thickness of 0.7 mm which is approximately the size of the sensor, and the FPC was crimp bonded to the ACF (CP906AM-25AC) manufactured by Sony Chemical Co., Ltd. at the top. A touch panel sensor was fabricated by attaching the above-mentioned soda lime glass to the side.

Using the touch panel sensor obtained above, a touch panel was fabricated by the following method.

A double-sided tape (manufactured by Nitto Denko, 5000NS) is attached to the peripheral portion of the hard coating film surface of the touch panel sensor obtained above, and the front polarizing plate and the hard coating film of the liquid crystal display panel including the front polarizing plate are opposed to each other. The touch panel was made by fitting it. In the obtained touch panel, there is an air layer surrounded by the double-sided tape between the liquid crystal display screen and the touch panel sensor.

It should be noted that the film B is disposed such that the in-plane slow axis of the PET film in the film B is parallel (0°) to the transmission axis of the front polarizing plate. Further, the HC-PET corresponding to the second protective substrate is disposed such that the in-plane slow axis of the HC-PET is parallel (0°) to the transmission axis of the front polarizing plate. Further, the PET film in HC-PET exhibited optical anisotropy, Nz was 4.3, Re (550) was 2800 nm, and nx was 1.642.

In addition, the touch panel sensor in the formed touch panel is equivalent to the manner in the third figure described above.

<Example 3>

A touch panel was manufactured in the same manner as in Example 2 except that the in-plane slow axis of the HC-PET was arranged orthogonal to the transmission axis of the front polarizing plate.

<Example 4>

[Formation of Conductive Film]

An etching mask material is formed on the ITO transparent conductive layer of the ITO substrate including the PET film (thickness: 100.1 μm) and the ITO transparent conductive layer by a negative photoresist method, and immersed in an etching solution for dissolving ITO to form A conductive film having a sensing electrode. The steps of each step are shown below.

It should be noted that 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 imparting) process -

The photosensitive composition (1) described later was bar-coated on the surface of the ITO transparent conductive layer to a dry film thickness of 5 μm, and dried in an oven at 150 ° C for 5 minutes. For this substrate, high pressure mercury lamp i-ray (365 nm) of 400 mJ/cm ² (illuminance 50 mW/cm ² ) was exposed from the exposure glass mask.

The exposed substrate was subjected to spray development with a 1% aqueous sodium hydroxide solution (35 ° C) for 60 seconds. The spray pressure was 0.08 MPa, and the time until the stripe pattern appeared was 30 seconds. After rinsing by spraying with pure water, it was dried at 50 ° C for 1 minute to prepare a conductive member with a resist pattern.

It should be noted that the exposure glass mask uses a mask capable of forming a sensing electrode of the capacitive touch panel sensor.

- etching process -

The conductive member with a resist pattern was immersed in an etchant for ITO. After immersing in an etching solution adjusted to 35 ° C for 2 minutes, etching treatment was performed, and after rinsing by spraying with pure water, water on the surface of the sample was blown off with an air knife, and dried at 60 ° C for 5 minutes to prepare a resist pattern. Patterned conductive component.

-Resist stripping process -

The patterned conductive member with a resist pattern after etching was spray-developed for 75 seconds with a 2.38% aqueous solution of tetramethylammonium hydroxide maintained at a temperature of 35 °C. The spray pressure was 3.0 MPa. After rinsing by spraying with pure water, the water on the surface of the sample was blown off with an air knife, and dried at 60 ° C for 5 minutes to prepare a conductive film.

In addition, as the conductive film, two conductive films (first conductive film and second conductive film) were produced by changing the pattern of the sensing electrodes. The sensing electrode of the first conductive film was an electrode (length: 170 mm) extending in the X direction, and was 32. Further, the sensing electrode of the second conductive film is an electrode (length: 300 mm) extending in the Y direction, and is 56.

- Preparation of photosensitive composition (1) -

As a monomer component constituting the copolymer, MAA (methacrylic acid: 7.79 g) and BzMA (benzyl methacrylate: 37.21 g) were used as a radical polymerization initiator, and AIBN (2,2'-azodiene was used. (isobutyronitrile): 0.5 g), and they were subjected to polymerization in a solvent PGMEA (propylene glycol monomethyl ether acetate: 55.00 g) to obtain a PGMEA solution of the binder (A-1) represented by the following formula ( Solid content concentration: 45% by mass). It should be noted that the polymerization temperature was adjusted to a temperature of from 60 ° C to 100 ° C.

The molecular weight was measured by gel permeation chromatography (GPC), and the weight average molecular weight (Mw) based on polystyrene conversion was 30,000, and the molecular weight distribution (Mw/Mn) was 2.21.

3.80 parts by mass of a 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, and IRGACURE 379 as a photopolymerization initiator ( 0.159 parts by mass of EHPE-3150 (manufactured by Daicel Chemical Co., Ltd.), 0.150 parts by mass of MEGAFACE F781F (manufactured by DIC Corporation), and 0.002 parts by mass of PGMEA, manufactured by Ciba Specialty Chemicals Co., Ltd. The photosensitive composition (1) was prepared by stirring.

[peripheral wiring property]

The lead wiring (peripheral wiring) connected to the sensing electrode in the conductive film formed by the above-described patterning is produced as follows. In other words, silver paste (DOTITE FA-401CA, manufactured by Fujikura Kasei Co., Ltd.) was printed by a screen printer, and then annealed at 130 ° C for 30 minutes to be cured to form a peripheral wiring.

In addition, the screen printing plate uses a printing plate which can form the peripheral wiring for a capacitive touch panel.

[Touch Panel Production Method]

Using the conductive film produced above, a touch panel was manufactured by the following method.

OCA (#8146-4: 100 μm thick) manufactured by 3M Co., Ltd. was bonded to the ITO layer of the second conductive film (bottom surface) obtained above, and bonded to the other first conductive film (top surface) via OCA. A laminate is formed on the opposite side of the ITO layer. The obtained laminate had a PET film, an ITO layer, an OCA, a PET film, and an ITO layer in this order. In addition, the OCA located at each of the other ends of the first lead-out wiring portion and the second lead-out wiring portion corresponding to the FPC crimping portion is opened in advance, and the FPC can be pressure-bonded.

OCA (#8146-4: 100 μm thick) manufactured by 3M Co., Ltd. was bonded to the ITO layer (top surface) of the laminate, and the outer shape was adjusted to be the same as the soda lime glass having a thickness of 0.7 mm which is substantially the size of the sensor. After the FPC was crimp-bonded by ACF (CP906AM-25AC) manufactured by Sony Chemical Co., Ltd., the above-mentioned soda lime glass was attached to the top side to prepare a touch panel sensor.

Using the touch panel sensor obtained above, a touch panel was fabricated by the following method.

A double-sided tape (5000NS manufactured by Nitto Denko Corporation) is attached to the peripheral portion of the surface of the PET film of the touch panel sensor obtained above, and the front polarizing plate of the liquid crystal display panel including the front polarizing plate and the PET film are attached to each other. In combination, a touch panel was produced. In the obtained touch panel, there is an air layer surrounded by the double-sided tape between the liquid crystal display screen and the touch panel sensor.

It is to be noted that the two conductive films are disposed such that the in-plane slow axis of the PET film in the respective conductive films is parallel (0°) to the transmission axis of the front polarizing plate.

In addition, the touch panel sensor in the formed touch panel is equivalent to the manner in the seventh figure described above.

<Example 5>

The same procedure as in Example 4 was carried out except that the in-plane slow axis of the PET film in the conductive film on the liquid crystal display side of the two conductive films was arranged to be orthogonal to the transmission axis of the front polarizing plate. Touch panel.

<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 fabricated in accordance with the same procedure as in Example 1 except that the PET film was used. It should be noted that the PET film used exhibited optical anisotropy, Nz was 1.0, and Re (550) was 1900 nm. The nx is 1.681.

<Evaluation method>

[Detection position accuracy evaluation method]

After the touch panel produced above was placed in an environment of 85% at 85 ° C for 240 hours, the positional accuracy of the touch panel was evaluated. Specifically, the display panel of the liquid crystal display panel is displayed with a 5 mm grid, and the area of the edge of each side of the rectangular input area of the touch panel sensor is drawn with a finger in parallel with respect to the side to evaluate the actual finger contact. The offset (maximum value) of the position and the trajectory displayed on the screen, and the offset (maximum) (mm) of the four sides / electrode wiring length (mm) × 100 (%) is calculated, and the maximum value is used as the position. Accuracy. When the value is ±2% or less, it is evaluated as A; when it is more than ±2% and ±5% or less, it is evaluated as B; and when it is ±5% or more, it is evaluated as C.

In the case where the electrode wiring length in the above formula is drawn by a finger in a region along the short side of the rectangular input region, the electrode wiring length in the above formula means the X sensing electrode (length: 170 mm) The length of the electrode wiring in the above formula is drawn by a finger in a region along the long side of the rectangular input region, and means that the length of the Y sensing electrode (length: 300 mm) is 300 mm.

[Rain spot evaluation]

The evaluation of the rainbow spot was carried out using the touch panel produced as described above. More specifically, as shown in the eighth figure, the angle formed by the touch panel plane and the observer's line of sight is set to the azimuth angle θ1, and the line orthogonal to the long side of the touch panel and the observer's line of sight are The resulting angle is set to the polar angle θ2. It should be noted that the direction of the long side of the touch panel is parallel to the transmission axis of the front polarizer in the liquid crystal display.

In a state where the polar angle = 0 or 90 and the azimuth angle of 30 to 45 (fixed) is the center of the observer's line of sight, the observer's line of sight is swung at a polar angle of ±30°, and observation is confirmed. The color of the rainbow spot was evaluated and evaluated according to the following criteria.

In at least one of the rainbow spot evaluation (the rainbow spot evaluation 0°) at the polar angle=0° and the rainbow spot evaluation (the rainbow spot evaluation 90°) at the polar angle=90°, the case where the score 4 is evaluated is evaluated as "A"; in at least one of the rainbow spot evaluation 0° and the rainbow spot evaluation 90°, the case of having a score of 3 is evaluated as "B"; the case where the rainbow spot is evaluated by 0° and the rainbow spot is evaluated by 90 degrees are both scores 2 The following case was evaluated as "C". It is to be noted that it is preferably "B" or more in practical use.

Score 1: For the polar and azimuthal changes, the rainbow spot is noticeably visible.

Score 2: For polar and azimuth changes, the rainbow spot is visible, but the coloration is lighter than 1.

Score 3: The rainbow spot is visible, but the allowable range.

Score 4: Rainbow spots cannot be recognized.

[Refractive index measurement]

The refractive indices (nx, ny, nx) of the PET films used in the respective examples and comparative examples were evaluated using an Abbe refractometer (Atago NAR-1T SOLID).

The evaluation results of the touch panel manufactured in the examples and the comparative examples are summarized in Table 1 below.

In addition, in Table 1, the "presence or absence" column of "protective substrate" indicates whether or not a protective substrate (HC-PET) exhibiting optical anisotropy is used.

In addition, in Table 1, "arrangement" indicates the relationship (orthogonal or parallel) of the in-plane slow axis of the substrate (PET film) or the protective substrate and the vibration direction of the linearly polarized light. " / " of Examples 4 and 5 respectively indicate the arrangement of the substrates in the two conductive films used.

As shown in Table 1, in the touch panel of the present invention, it was confirmed that the generation of rainbow spots and the deterioration of the 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.

The above is only a part of the embodiments of the present invention, and is not intended to limit the present invention. It is intended to be included in the scope of the present invention.

In summary, the embodiments of the present invention can achieve the expected use efficiency, and the specific technical means disclosed therein have not been seen in similar products, nor have they been disclosed before the application, and have completely complied with the patent law. The regulations and requirements, the application for invention patents in accordance with the law, and the application for review, and the grant of patents, are truly sensible.

1‧‧‧ touch panel

2‧‧‧Image display panel

3,300,400,500‧‧‧ touch panel sensor

4‧‧‧Image display unit

5‧‧‧Polarizer

6‧‧‧Organic EL unit

7‧‧‧1/4 wave plate

8‧‧‧Polar polarizer

9‧‧‧Organic EL panel

12‧‧‧Substrate

14‧‧‧1st sensing electrode

16‧‧‧1st lead wiring

18‧‧‧2nd sensing electrode

20‧‧‧2nd lead wiring

30‧‧‧Electrical thin wires

32‧‧‧ lattice

40‧‧‧1st transparent resin layer

42‧‧‧2nd transparent resin layer

50‧‧‧1st protective substrate

52‧‧‧2nd protective substrate

60‧‧‧1st substrate

62‧‧‧2nd substrate

First FIG.: A cross-sectional view of an embodiment of a touch panel of the present invention

Second drawing: a cross-sectional view of another embodiment of the touch panel of the present invention

Third: a top view showing one embodiment of a touch panel sensor

Fourth: Sectional view taken along the cutting line A-A shown in the third figure

Fifth: enlarged top view of the first sensing electrode

Figure 6: Partial cross section of the second embodiment of the touch panel sensor

FIG. 7 is a partial cross section of a third embodiment of the touch panel sensor

Figure 8: Schematic diagram showing the relationship between polar angle and azimuth

2‧‧‧Image display panel

3‧‧‧Touch panel sensor

4‧‧‧Image display unit

5‧‧‧Polarizer

Claims (7)

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, wherein: the touch panel sensor includes at least a display An optically anisotropic substrate; the substrate satisfies the relationship of the following formula (1); the touch panel is slower in accordance with a vibration direction of the linearly polarized light emitted by the image display panel and an in-plane of the substrate The axis is orthogonal or parallel; the maximum refractive index nx in the plane of the substrate is 1.60 or more; Formula (1): Nz>3.0; It should be noted that Nz represents the Nz coefficient at a substrate having a wavelength of 550 nm. When the maximum refractive index in the plane is nx, the refractive index at a wavelength of 550 nm in the direction orthogonal to nx in the substrate plane is ny, and the refractive index in the thickness direction of the substrate at a wavelength of 550 nm is nz. Nz is a value obtained by Nz = (nx - nz) / (nx - ny). The touch panel of claim 1, wherein the nx is 1.61 to 1.70. The touch panel according to claim 1 or 2, wherein the retardation value Re (550) of the substrate measured at a wavelength of 550 nm is from 1000 nm to 3500 nm. The touch panel of claim 1 or 2, wherein the substrate comprises polyethylene terephthalate. The touch panel of claim 1 or 2, wherein the sensing electrode included in the touch panel sensor has a mesh pattern, and the mesh pattern consists of two or more conductive thin wires intersecting Composition. The touch panel of claim 5, wherein the conductive thin wire comprises at least one selected from the group consisting of gold, silver, and copper. A conductive film disposed on a viewing side of an image display panel that emits linearly polarized light, wherein: the conductive film includes a substrate exhibiting 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 maximum refractive index nx in the plane of the substrate is 1.60 or more; Formula (1): Nz>3.0; It should be noted that Nz represents an Nz coefficient at a wavelength of 550 nm. The maximum refractive index in the plane of the substrate 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 refractive index in the thickness direction of the substrate at a wavelength of 550 nm is nz. , Nz is a value obtained by Nz = (nx - nz) / (nx - ny).