JP5347037B2 - Photosensitive material for producing conductive sheet, conductive sheet, transparent conductive sheet, and capacitive touch panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve visibility of a touch panel by decreasing a difference between tones of a front surface and a rear surface of a transparent conductive sheet. <P>SOLUTION: Provided is a photosensitive material for manufacturing a conductive sheet, in which the photosensitive material forms photosensitive layers including silver halide emulsions on two surfaces (a front surface and a rear surface) of a transparent support body separately. The photosensitive material is characterized in that the photosensitive layer on at least one side of the front surface or the rear surface includes a mercapto compound. <P>COPYRIGHT: (C)2013,JPO&amp;INPIT

Description

  The present invention relates to a transparent conductive sheet having a high-definition pattern of conductive fine lines formed on a transparent support, a photosensitive material for producing a transparent conductive sheet having a high-definition pattern of conductive thin lines, and a transparent conductive sheet. The present invention relates to a manufacturing method and a capacitive touch panel using these transparent conductive sheets.

In the field of touch panels, projection capacitive touch panels have been widely used for PDAs, mobile phones, and the like, and attempts to increase the size of touch panels of this type have begun. When increasing the size of the panel, it is essential to reduce the resistance of the transparent electrode. As a technique for reducing the resistance, a method of forming a capacitance sensing portion with a mesh-like conductive thin wire is disclosed in, for example, Patent Literature 1 and 2. The method for forming a mesh-like conductive fine wire described in these documents is a conductive ink printing method or thinning by photolithography of ITO or a metal thin film. In the former printing method, the method is 20 μm or less. There is a problem that it is difficult to stably form a thin line having a line width, and in the latter case, the photolithography process is composed of a plurality of processes, resulting in a high cost.
On the other hand, a method of forming a low-resistance conductive fine wire from a silver image obtained by developing a silver halide photographic light-sensitive material has been studied in the field of electromagnetic shielding films and printed wiring. In this method, since various patterns can be formed by exposure through a mask and subsequent development processing, the manufacturing process is stable. As a developing system, for example, Patent Document 3 can be cited, and an example of a surface resistance of 50 to 100Ω / □ with a mesh pattern having a fine line width of 20 μm and a lattice spacing of 250 μm is described.
In the method of creating a capacitance sensing unit using these thin conductive wires, when a touch panel is formed by laminating a first electrode and a second electrode as shown in FIG. The layers need to be laminated so as to have a uniform mesh shape as shown in FIG. 8 when viewed from the side. If the electrodes are not uniform and non-uniform electrode overlaps or blanks occur, the screen will appear non-uniform, resulting in poor visibility. For this reason, high accuracy is required for alignment of the two conductive sheets, and alignment with high accuracy is performed for each touch panel, which causes a problem that productivity of the touch panel is inferior.

JP 2010-039537 A International Publication No. 2010/014683 JP 2007-188655 A

In recent years, an attempt has been made to form electrodes on both sides of the back of a single transparent support in order to simplify the alignment when two conductive sheets are bonded. Electrodes made of thin conductive wires formed on the front and back surfaces of the transparent support need to be visually recognized as a uniform pattern as shown in FIG. 8 of Patent Document 1, and therefore, a photosensitive material is used as the electrode forming material. It is believed that a method of forming an electrode by the subsequent exposure and subsequent development processing is advantageous.
However, a sample in which electrodes are formed on both front and back surfaces of a transparent support can be used even if the exposure pattern is precisely aligned so that the perspective image of the front and back electrodes is a uniform pattern. It was found that subtle color unevenness occurred. In addition, the phenomenon in which the color of the formed electrode surface changes depending on the conditions for forming the electrode is a particularly thick electrode even in a method of printing a conductive ink such as a silver paste or a method using vapor deposition or sputtering. May be observed when forming. These phenomena are presumed to be due to the difference in the microstructure of the metal film between the initial film and the thick film when a relatively thick electrode film is formed. Absent.

  The present invention has been made in consideration of such problems, and an object thereof is to provide a transparent conductive sheet in which the color tone of the electrode surface is controlled. Another object of the present invention is to provide a transparent conductive sheet in which the color tone of an electrode made of developed silver is controlled. Moreover, this invention aims at provision of the manufacturing method of the transparent conductive sheet which controlled the color tone of these electrodes. Furthermore, an object of the present invention is to provide a transparent electrode that controls the color tone of the electrode and has a low resistance and can be used for a large-screen touch panel. Another object of the present invention is to provide uses other than the touch panel using the transparent conductive sheet having the improved color tone.

As a result of intensive investigation of the cause of the above-described unevenness in color, the present inventors have reached the present invention from the following facts.
FIG. 1 shows a cross-sectional view when a transparent electrode having first and second electrodes formed on both front and back surfaces of a single transparent support is used in a projected capacitive touch panel. 1 shows a transparent support 31 that also serves as a touch surface, an adhesive layer 41 that also serves as an insulating layer, a conductive thin wire 21 that constitutes an upper electrode, a transparent support 32 for an electrode, and a lower electrode, from the upper toucher side. It is a schematic cross section of the touch panel 01 comprised by the electroconductive fine wire 22 to perform, the adhesion layer 41 which serves as an insulating layer, and the transparent support 33. In the configuration of FIG. 1, the toucher (viewer) views the conductive thin wires 21 constituting the upper electrode and the conductive thin wires 22 constituting the lower electrode alternately. Specifically, as shown in FIG. 1, in the conductive thin wire 21, the surface of the conductive thin wire 21 on the side far from the transparent support from the direction of arrow b1 is visually recognized. In the thin conductive wire 22, the surface of the thin conductive wire 22 on the side closer to the transparent support from the direction of arrow b2 is visually recognized. When the distance d1 between the conductive thin wires of the upper and lower electrodes is equal to or less than the identification distance of human eyes (in most cases, 0.1 mm or less), it is difficult to feel uneven color.
On the other hand, when one electrode is composed of a plurality of conductive thin wires (for example, the capacitance sensing part is in a mesh shape or a long lattice shape), as shown in FIG. There is a region d2 in which a plurality of conductive thin wires are arranged, and then a region d3 in which a plurality of conductive thin wires are arranged on the other surface, and the length of d2 and d3 is a distance recognized by a person. However, in the embodiment as shown in FIG. 2, it has been found that color unevenness is recognized depending on the electrode formation conditions, and the following invention has been achieved. FIG. 2 is a diagram showing a model of a cross section when the square lattice of FIG. 9 is cut in parallel to the long-side line of the lattice, for example.

<1>
A photosensitive material for producing a conductive sheet, in which a photosensitive layer containing a silver halide emulsion is formed on both sides (a front side and a back side) of a transparent support, respectively, wherein the front side photosensitive layer or the back side is provided. The photosensitive layer on at least one side of the photosensitive layer comprises a mercapto compound;
The photosensitive material for producing a conductive sheet is characterized in that the mercapto compound contained in the photosensitive layer is contained more in the photosensitive layer closer to the transparent support than in the photosensitive layer far from the transparent support of the photosensitive layer. .
<2>
The photosensitive material for producing a conductive sheet according to <1>, wherein the photosensitive layer on either the front surface or the back surface of the transparent support does not contain a mercapto compound.
<3>
The photosensitive sheet for producing a conductive sheet according to <1>, wherein the amount of mercapto compound contained in the photosensitive layer on the back surface is greater than the amount of mercapto compound contained in the photosensitive layer on the front surface of the transparent support. material.
<4>
The amount of the mercapto compound contained in at least one photosensitive layer of the photosensitive layer is 0.1 mg or more and 15 mg or less with respect to 1 g (gram) of silver in the silver halide emulsion contained in the same layer as the mercapto compound. The photosensitive material for producing a conductive sheet according to any one of <1> to <3>, wherein:
<5>
<1> to <4>, wherein the volume ratio of silver and binder contained in the photosensitive layer formed on both surfaces of the transparent support is 1.0 or more. Photosensitive material.
<6>
The conductive sheet according to any one of <1> to <5>, wherein the photosensitive layers on both surfaces of the transparent support have antihalation layers between the transparent support and the respective photosensitive layers. Photosensitive material for manufacturing.
<7>
<1>-<6> The front surface which consists of a conductive fine wire of developed silver by performing image-like pattern exposure on both surfaces of the photosensitive material for conductive sheet manufacture of any one of <6>, and then developing. A conductive sheet, wherein a transparent electrode and a backside transparent electrode made of a developed thin conductive silver wire are formed on both sides of a transparent support.
<8>
The conductive direction according to <7>, wherein the conduction direction of the front surface transparent electrode and the conduction direction of the back surface transparent electrode are formed by exposure and development so as to be orthogonal to each other. Sheet.
<9>
The absolute value of the difference between the reflection chromaticity b ₁ ^* of the electrode surface on the side far from the transparent support of the front surface electrode and the reflection chromaticity b ₂ ^* of the electrode surface on the side close to the transparent support of the back surface electrode <2> or less (| Δb ^* | = | b ₁ ^* −b ₂ ^* | ≦ 2), The transparent conductive sheet according to <7> or <8>.
<10>
<7>-<9> The capacitive touch panel using the transparent conductive sheet of any one of <9>.
Although the present invention relates to the above <1> to <10>, other matters including the matters described in the following [1] to [30] are also described for reference.
[1] A photosensitive material for producing a conductive sheet, in which a photosensitive layer containing a silver halide emulsion is formed on both sides (a front surface and a back surface) of a transparent support, respectively. A photosensitive material for producing a conductive sheet, wherein the photosensitive layer on at least one side of the photosensitive layer on the back side or the back side contains a mercapto compound.
[2] Item 1 is characterized in that the mercapto compound contained in the photosensitive layer is contained more in the photosensitive layer closer to the transparent support than in the photosensitive layer far from the transparent support in the photosensitive layer. The photosensitive material for conductive sheet manufacture of description.
[3] The photosensitive material for producing a conductive sheet according to Item 1 or 2, wherein the photosensitive layer on either the front surface or the back surface of the transparent support does not contain a mercapto compound.
[4] Any one of Items 1 to 3, wherein the amount of mercapto compound contained in the photosensitive layer on the back surface is greater than the amount of mercapto compound contained in the photosensitive layer on the front surface of the transparent support. The photosensitive material for electroconductive sheet manufacture as described in claim | item.

[5] The amount of mercapto compound contained in at least one photosensitive layer of the photosensitive layer is 0.1 mg or more and 15 mg based on 1 g (gram) of silver in the silver halide emulsion contained in the same layer as the mercapto compound. Item 5. The photosensitive material for producing a conductive sheet according to any one of Items 1 to 4, which is:
[6] The mercapto compound is a mercapto compound having a 5-membered ring azole having an NH structure or a 6-membered ring azine having an NH structure as a skeleton, and the NH structure is an azole or azine. Item 6. The photosensitive material for producing a conductive sheet according to Item 4 or 5, which means a nitrogen-hydrogen bond contained, wherein the hydrogen is dissociable.
[7] The mercapto compound has an SO ³ M group as a substituent at any of the 4th to 7th positions of 2-mercaptobenzimidazole, and further a hydrogen atom, hydroxyl group, lower alkyl group, lower alkoxy group, carboxyl group Item 8. The photosensitive material for producing a conductive sheet according to Item 7, having at least one group selected from a halogen group and a sulfo group as a substituent, wherein M is an alkali metal atom or an ammonium group.

[8] The silver bromide content of the silver halide emulsion of the photosensitive layer formed on both sides of the transparent support is 50 mol% or more, and the mercapto compound is contained only in the photosensitive layer close to the transparent support. Item 8. The photosensitive material for producing a conductive sheet according to any one of Items 1 to 7,
[9] Item [1] is characterized in that it has a layer in which the volume ratio of silver and binder contained in the photosensitive layer formed on both surfaces of the transparent support is 1.0 or more. Photosensitive material for producing conductive sheets.
[10] The photosensitive material for producing a conductive sheet according to any one of Items 1 to 9, wherein the volume ratio of silver and binder in the layer is 1.5 or more.
[11] Item 1-10, wherein the volume ratio of silver and binder contained in the photosensitive layer on the side close to the support of at least one of the front and back photosensitive layers is less than 1.0. The photosensitive material for electroconductive sheet manufacture of any one of these.
[12] Item 1-11, wherein the volume ratio of silver and binder contained in the photosensitive layer far from the support of at least one photosensitive layer on the front side and the back side is less than 0.5. The photosensitive material for electroconductive sheet manufacture of any one of Claims 1.
[13] The volume ratio of silver and binder contained in the photosensitive layer far from the support of the photosensitive layer on one side of the front side and the back side is less than 0.5, and the photosensitive layer on the other side is Item 13. The photosensitive material for producing a conductive sheet according to any one of Items 1 to 12, wherein the volume ratio of silver and binder contained in the photosensitive layer on the side close to the support is less than 0.5.
[14] The conductive sheet according to any one of items 1 to 13, wherein the photosensitive layers on both sides of the transparent support have an antihalation layer between the transparent support and each photosensitive layer. Photosensitive material for manufacturing.

[15] A front surface composed of conductive thin wires of developed silver by performing imagewise pattern exposure on both sides of the photosensitive material for producing a conductive sheet according to any one of items 1 to 14, followed by development processing. A conductive sheet, wherein a transparent electrode and a backside transparent electrode made of a developed thin conductive silver wire are formed on both sides of a transparent support.
[16] Item 15 wherein the conduction direction of the front surface transparent electrode and the conduction direction of the back surface transparent electrode are formed by exposure and development processing so as to be orthogonal to each other. Conductive sheet.
[17] The conductive sheet according to item 15 or 16, wherein the transparent electrode made of a conductive thin wire is a patterned electrode made of a plurality of conductive thin wires.
[18] The conductive sheet according to item 17, wherein the patterned electrode has a square lattice or a rectangular lattice in the electrode by a conductive thin wire.
[19] The conductive sheet according to any one of items 15 to 18, wherein a line width of the conductive fine wire constituting the patterned electrode is 1 μm or more and 10 μm or less.
[20] The transparent conductive sheet according to any one of items 15 to 18, wherein a line width of the conductive fine wire is 2 μm or more and 6 μm or less.

[21] The conductive sheet according to any one of items 15 to 20, wherein the thickness of the conductive thin wire is 0.1 μm or more and 1.5 μm or less.
[22] The conductive sheet according to any one of items 15 to 21, wherein the thickness of the conductive thin wire is 0.2 μm or more and 0.8 μm or less.
[23] The reflection chromaticity b ₁ ^* of the electrode surface on the side far from the transparent support of the front electrode of the conductive sheet and the reflection chromaticity b ₂ of the electrode surface on the side of the back electrode close to the transparent support. Item 21. The transparent conductive material according to any one of Items 15 to 22, wherein an absolute value of a difference from ^* is 2 or less (| Δb ^* | = | b ₁ ^* −b ₂ ^* | ≦ 2) Sheet.
[24] The transparent conductive sheet according to Item 23, wherein | Δb ^* | is 1 or less.
[25] Item 23 or 24, wherein b ₁ ^* and b ₂ ^* are −2.0 <b ₁ ^* ≦ 0 and −1.0 <b ₂ ^* ≦ 1.0. Transparent conductive sheet.
[26] Item 25, wherein b ₁ ^* and b ₂ ^* satisfy −1.0 <b ₁ ^* ≦ −0.5 and −0.5 <b ₂ ^* ≦ 0.2 The transparent conductive sheet as described.
[27] A capacitive touch panel using the conductive sheet according to any one of items 15 to 26.
[28] The photosensitive material for producing a conductive sheet according to any one of items 1 to 14 is subjected to imagewise exposure, and then a substantially transparent electrode composed of a developed silver network conductor wire is formed by development processing. In the method for producing a conductive sheet, the image-wise exposure method is a method for simultaneously exposing different electrode patterns to the photosensitive materials on both sides of the photosensitive material for producing a conductive sheet.
[29] The method for producing a conductive sheet according to item 28, wherein the exposure is scanning exposure.
[30] The method for producing a conductive sheet according to item 28, wherein the exposure is a surface exposure through different masks.
In the present invention, the front surface and the back surface are the surfaces close to the viewer and the surfaces far from the viewer when the photosensitive material and the conductive sheet are configured as a visual device such as a touch panel. It is called a surface.

  The above-described transparent conductive sheet with improved color tone according to the present invention is not limited to the electrode material used for the above capacitive touch panel because the color tone of the surface of the conductive material is improved. It can be applied to all applications that relate to conductivity and conductivity. These are applicable. Transparent conductive sheets used for resistive film type touch panels, electromagnetic wave shielding sheets for shielding electromagnetic waves from the inside of image display devices, etc., simply change the pattern of conductive thin wires formed by patterning the electrodes of the present invention. The technology of the present invention can be used. Further, a heating element sheet or an antistatic sheet can be prepared by adjusting the resistance value of the electrode of the present invention.

When the photosensitive material for producing a conductive sheet of the present invention is subjected to pattern exposure and development processing, an upper electrode and a lower electrode composed of developed silver fine wires are formed on both sides of the transparent support. The pattern exposure is performed from above and below so that the conduction direction between the upper electrode and the lower electrode formed by the development process is orthogonal and recognized as a uniform pattern when visually recognized. Therefore, the present invention can be a stable and inexpensive method for producing a conductive sheet. On the other hand, unevenness of color when the electrode is visually recognized, which is a problem of this method, is solved by the photosensitive material for producing a conductive sheet of the present invention.
As described above, when a touch panel is constituted by a conductive sheet using the photosensitive material for producing a conductive sheet of the present invention, a large-screen touch panel can be obtained with little color unevenness and low resistance. Further, when the transparent conductive sheet of the present invention is applied, a transparent conductive sheet, an electromagnetic wave shield sheet, a heating element sheet and an antistatic sheet excellent in color tone can be obtained.

It is sectional drawing of the touchscreen model which formed the electrode on both surfaces of the transparent support body. It is a detailed sectional view of a touch panel model in which electrodes are formed on both surfaces of a transparent support. It is sectional drawing of the photosensitive material used in order to manufacture the transparent conductive sheet of this invention. It is the figure which showed the process which manufactures the transparent conductive sheet which formed the electrode on both surfaces of the transparent support body of this invention. It is a figure which exposes on both surfaces of the photosensitive material of this invention through a photomask. 2 is a perspective view of a laminate of an upper conductive sheet 11 and a lower conductive sheet 12. FIG. It is a figure explaining the electroconductive grating | lattice part and connection part of the upper conductive sheet of FIG. It is a figure explaining the electroconductive grating | lattice part and connection part of the lower conductive sheet of FIG. It is a perspective view from the toucher side when an upper conductive sheet and a lower conductive sheet are laminated. It is a schematic diagram of 1 aspect of the lamination | stacking system of an upper conductive sheet and a lower conductive sheet. It is a schematic diagram of 1 aspect of the lamination | stacking system of an upper conductive sheet and a lower conductive sheet. It is a schematic diagram of 1 aspect of the lamination | stacking system of an upper conductive sheet and a lower conductive sheet.

  Hereinafter, referring to FIGS. 1 to 12, embodiments of a photosensitive material according to the present invention, a conductive sheet formed using the photosensitive material, a method for manufacturing the conductive sheet, and a touch panel using the conductive sheet of the present invention will be described. While explaining. In the present specification, “to” is used as a meaning including numerical values described before and after the lower limit value and the upper limit value. In this case, in the touch panel described later, the surface on the toucher side is referred to as the front surface, and the surface far from the toucher is referred to as the back surface. In the drawings used in this case, the upper surface is called the front surface, and the lower surface is called the back surface.

[Photosensitive material]
The light-sensitive material of the present invention is a light-sensitive material for producing a conductive sheet in which a light-sensitive layer containing a silver halide emulsion is formed on both surfaces (a front surface and a back surface) of a transparent support, respectively. The photosensitive material for producing a conductive sheet, wherein the photosensitive layer on at least one side of the photosensitive layer on the side or the photosensitive layer on the back side contains a mercapto compound.
The photosensitive material of the present invention has a configuration having photosensitive layers on both sides of a transparent support, and a typical configuration will be described with reference to FIG. An upper photosensitive material layer (also referred to as a front surface photosensitive material layer) 50 is provided on the front side of the transparent support 32, and a lower photosensitive material layer (also referred to as a back side photosensitive material layer) 60 is provided on the rear side. Is formed.
The upper photosensitive material layer 50 includes an undercoat layer 56, an antihalation layer 57, an upper photosensitive layer (also referred to as a front surface photosensitive layer) 51 containing a silver halide emulsion, and a protective layer 55 formed on the transparent support 32. Has been. The undercoat layer, the antihalation layer, and the protective layer are layers provided as necessary. The upper photosensitive layer 51 may be formed of a photosensitive layer containing several silver halide emulsions and an intermediate layer between the photosensitive layers. In the present invention, the photosensitive layer 51 is divided into three photosensitive layers, that is, from the side close to the transparent support 32, an upper first photosensitive layer 52 (also referred to as an upper u layer) and an upper second photosensitive layer 53 (also referred to as an upper m layer). The upper third photosensitive layer 54 (also referred to as the upper o layer) will be described separately.
The lower photosensitive material layer 60 also has a layer configuration similar to that of the upper photosensitive material layer 50, and preferably has a symmetrical layer configuration around the transparent support.

(Transparent support)
As the transparent support used in the photosensitive material of the present invention, a plastic film, a plastic plate, a glass plate and the like can be used, and a plastic film is preferable.
Examples of plastic film materials include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN); polyolefins such as polyethylene (PE), polypropylene (PP) and polystyrene; polyvinyl chloride and polyvinylidene chloride Other vinyl chloride resins such as polyether ether ketone (PEEK), polysulfone (PSF), polyether sulfone (PES), polycarbonate (PC), polyamide, polyimide, acrylic resin, triacetyl cellulose (TAC), etc. Can be used.
The plastic film in the present invention can be used as a single layer, but can also be used as a multilayer film in which two or more layers are combined.
As the support, PET (258 ° C.), PEN (269 ° C.), PE (135 ° C.), PP (163 ° C.), polystyrene (230 ° C.), polyvinyl chloride (180 ° C.), polyvinylidene chloride (212 ° C.) A plastic film having a melting point of about 290 ° C. or less such as TAC (290 ° C.) is preferable, and PET is particularly preferable. Figures in parentheses are melting points. The transmittance of the film is preferably 85% to 100%.
The thickness of the transparent support film can be arbitrarily selected in the range of 50 μm or more and 500 μm or less. In particular, in the case where it also functions as a touch surface in addition to the function of the support of the transparent conductive sheet, it can be designed with a thickness exceeding 500 μm. When a photosensitive layer containing a silver halide emulsion is provided on a transparent support by a coating method, the thickness of the film is preferably 50 μm or more and 250 μm or less from the viewpoint of production.

[Mercapto compound]
The mercapto compound needs to be contained in at least one of the front surface photosensitive layer 51 and the back surface photosensitive layer 61. With such an embodiment, it is possible to improve color unevenness when a touch panel described later is created.
The mercapto compound contained in the photosensitive layer is preferably contained in a larger amount in the photosensitive layer closer to the transparent support than in the photosensitive layer farther from the transparent support. That is, it is preferably included in the m layer or the u layer, and more preferably included in the u layer, rather than the o layer. Alternatively, it is preferable to increase the concentration of the mercapto compound in the order of the o layer, the m layer, and the u layer.
When the photosensitive layer on either the front surface or the back surface of the transparent support contains a mercapto compound, the other photosensitive layer preferably does not contain a mercapto compound, and the photosensitive layer does not contain a mercapto compound. A front photosensitive layer is more preferable.
When both the front side photosensitive layer and the back side photosensitive layer of the transparent support contain a mercapto compound, it is preferable that the amount of the mercapto compound in the front side and the back side photosensitive layer is different. It is more preferable that the amount of mercapto compound contained in the photosensitive layer on the back surface is larger than the amount of mercapto compound contained in the photosensitive layer.

  The amount of the mercapto compound contained in at least one of the plurality of photosensitive layers of the present invention is 0.1 mg or more and 15 mg or less with respect to 1 g (gram) of silver in the silver halide emulsion contained in the same layer as the mercapto compound. It is preferably 0.5 mg or more and 10 mg or less, more preferably 1 mg or more and 6 mg or less. It is easy to adjust the color when it is in the range of 0.1 mg or more and 15 mg or less.

Examples of the mercapto compound used in the present invention include an alkyl mercapto compound, an aryl mercapto compound, a heterocyclic mercapto compound, and the like. From the paragraph 34 of JP-A-2007-116137, The compound described in paragraph 102 can be used.
Among the compounds described in Paragraph 34 to Paragraph 102 of JP-A-2007-116137, a 5-membered ring azole having an NH structure or a mercapto compound having a 6-membered ring azine having an NH structure as a skeleton is preferable. . The N—H structure means a nitrogen-hydrogen bond contained in azoles or azines, and the hydrogen is characterized by being dissociable.
The 5-membered azoles or 6-membered azines that form the skeleton structure of the mercapto compound may be monocyclic, but are preferably complex heterocycles in which two or more rings are condensed. A preferable structure of the complex heterocyclic ring may be a complex ring (condensed ring) of a 5-membered ring azoles or a 6-membered ring azines and a benzene ring having no hetero atom, and a 5-membered ring azoles It may be a complex ring (condensed ring) with a 6-membered ring azine. More specifically, it is preferably a complex ring in which pyrimidine, pyrazole, imidazole, and phenyl rings are condensed. Particularly preferred ring structures are benzimidazole and benzopyrazole.
In addition to the mercapto group, the ring includes a hydroxyl group, a sulfo group, a carboxyl group, a nitro group, a halogen atom (for example, a chlorine atom, a bromine atom), an aryl group (for example, phenyl, 4-methanesulfonamidophenyl, 4-methylphenyl, 3,4-dichlorophenyl and naphthyl groups), aralkyl groups (for example, benzyl, 4-methylbenzyl and phenethyl groups), sulfonyl groups (for example, methanesulfonyl, ethanesulfonyl and p-toluenesulfonyl groups), It may have a carbamoyl group (for example, unsubstituted carbamoyl, methylcarbamoyl, phenylcarbamoyl groups), a sulfamoyl group (for example, unsubstituted sulfamoyl, methylsulfamoyl, phenylsulfamoyl groups), a sulfo group, It preferably has a carboxyl group. These water-soluble groups may have an alkali metal salt structure.

Among these mercapto compounds, compounds preferably used in the present invention include 39 compounds described in paragraphs 60 to 65 of JP-A-2007-116137, 55 compounds described in paragraphs 90 to 93, and 101 compounds. The following three compounds can be mentioned. Among these compounds, compounds that can be preferably used according to the present invention are the compounds described in paragraphs 60, 65, and 101.
Among the above mercapto compounds, 2-mercaptobenzimidazole has an SO ³ M group as a substituent at any of the 4th to 7th positions, and further has a hydrogen atom, hydroxyl group, lower alkyl group, lower alkoxy group, carboxyl Most preferred are compounds having at least one group selected from a group, a halogen group, and a sulfo group as a substituent, and M is an alkali metal atom or an ammonium group, and particularly preferred compounds are the three compounds described in paragraph 101.

[Photosensitive layer containing silver halide emulsion]
Next, a photosensitive layer containing a silver halide emulsion will be described. In order to use developed silver as an electrode material, the type of photosensitive material and the type of development processing can be selected from the following three methods. it can.
(1) A method in which a photosensitive silver halide black-and-white photosensitive material not containing physical development nuclei is chemically or thermally developed to form a metallic silver portion on the photosensitive material.
(2) A system in which a photosensitive silver halide black-and-white photosensitive material containing physical development nuclei in a silver halide emulsion layer is dissolved and physically developed to form a metallic silver portion on the photosensitive material.
(3) A photosensitive silver halide black-and-white photosensitive material that does not contain physical development nuclei and an image-receiving sheet having a non-photosensitive layer that contains physical development nuclei are overlaid and diffused and transferred to develop a non-photosensitive image-receiving sheet. Forming on top.

The mode (1) is a black-and-white development type, and a light-transmitting conductive film such as a light-transmitting electromagnetic wave shielding film is formed on the photosensitive material. The developed silver obtained is chemically developed silver or heat developed silver, and is a filament with a high specific surface. Furthermore, when a subsequent process of plating or physical development is provided, it is a highly active and preferable method.
In the above aspect (2), in the exposed portion, the silver halide grains close to the physical development nucleus are dissolved and deposited on the development nucleus, whereby a light transmissive electromagnetic wave shielding film or a light transmissive conductive sheet is formed on the photosensitive material. A translucent conductive film such as is formed. This is also a black and white development type. Although the developing action is precipitation on physical development nuclei, it is highly active, but the developed silver obtained has a spherical shape with a small specific surface.
In the above aspect (3), the silver halide grains are dissolved and diffused in the unexposed area and deposited on the development nuclei on the image receiving sheet, whereby a light transmitting electromagnetic wave shielding film or a light transmitting conductive film is formed on the image receiving sheet. A translucent conductive film such as a sheet is formed. This is a so-called two-sheet separate type in which the image receiving sheet is peeled off from the photosensitive material.
In either embodiment, either negative development processing or reversal development processing can be selected (in the case of the diffusion transfer method, negative development processing is possible by using an auto-positive type photosensitive material as the photosensitive material). .

  The chemical development, thermal development, dissolution physical development, and diffusion transfer development referred to here have the same meanings as are commonly used in the art, and a general textbook of photographic chemistry such as Shinichi Kikuchi, “Photochemistry” (Kyoritsu) Published by publisher), C.I. E. K. It is described in “The Theory of Photographic Process, 4th ed.” Edited by Mees (Mcmillan, 1977). Further, for example, the techniques described in JP-A Nos. 2004-184893, 2004-334077, and 2005-010752 can be referred to.

Among the above methods (1) to (3), since the method (1) does not have a physical development nucleus in the photosensitive layer before development and is not a two-sheet diffusion transfer method, the method (1) Is the most convenient and stable treatment, and is preferable for producing the transparent conductive sheet of the present invention. In the following, the description of the method (1) will be described. However, when other methods are used, it is possible to refer to the document described in the upper part. Note that “dissolved physical development” is not a development method unique to the method (2) but a development method that can also be used in the method (1).
(Silver halide emulsion)

  The halogen element contained in the silver halide emulsion of the present invention may be any of chlorine, bromine, iodine and fluorine, or a combination thereof. 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. Silver chlorobromide, silver iodochlorobromide and silver iodobromide are also preferably used. More preferred are silver chlorobromide, silver bromide, silver iodochlorobromide and silver iodobromide, and most preferred are silver chlorobromide and silver iodochlorobromide containing 50 mol% or more of silver chloride. Used.

  Here, “silver halide mainly composed of silver bromide” refers to silver halide in which the molar fraction of bromide ions in the silver halide composition is 50% or more. The silver halide grains mainly composed of silver bromide may contain iodide ions and chloride ions in addition to bromide ions.

  The silver iodide content in the silver halide emulsion is preferably in a range not exceeding 1.5 mol% per mole of silver halide emulsion. By setting the silver iodide content in a range not exceeding 1.5 mol%, fogging can be prevented and the pressure property can be improved. A more preferred silver iodide content is 1 mol% or less per mole of silver halide emulsion.

  Regarding the average grain size of silver halide, the shape and dispersion degree of silver halide grains, and the coefficient of variation, reference can be made to the descriptions in paragraphs 36 and 37 of JP-A-2009-188360. Regarding the use of metal compounds belonging to Group VIII and VIIB, such as rhodium compounds and iridium compounds, and palladium compounds, which are used for stabilizing and enhancing the sensitivity of silver halide emulsions, paragraph 39 of JP-A-2009-188360. -The description of paragraph 42 can be referred to. Further, regarding chemical sensitization, reference can be made to the technical description in paragraph 43 of JP2009-188360A.

  The silver halide emulsion used in the present invention is preferably a silver chlorobromide emulsion. Further, before development, in order to suppress fogging during development, a small amount of silver iodide is preferably contained, more preferably about 0.5 mol%. In the following, no indication is given even if silver iodide is included to the extent shown on the left.

In the present invention, in order to adjust the reflection chromaticity of the electrode composed of the conductive thin wire of developed silver formed after the development processing of the photosensitive material 05 of the present invention, the photosensitive layers 51 and 61 are formed as shown in FIG. A photosensitive layer (u layer), a second photosensitive layer (m layer), and a third photosensitive layer (o layer) are coated and formed as a photosensitive layer having a three-layer structure. The photosensitive layer is divided into multiple layers in the same manner as the emulsion layers of the silver halide photographic light-sensitive material are formed as an o layer, an m layer, and a u layer in order of increasing photosensitivity. By making multiple layers, adjustments such as sensitivity and gradation can be facilitated. Also in the present invention, for the sake of understanding the layers, for convenience, they are abbreviated as o layer, m layer, and u layer, but this does not represent the level of sensitivity. The o layer, which is the third photosensitive layer, is the photosensitive layer located farthest from the transparent support, and the u layer, which is the first photosensitive layer, is the photosensitive layer located closest to the transparent support. Such a three-layered photosensitive layer (o layer / m layer / u layer configuration) is preferably formed by simultaneous coating.
In the present invention, the thickness of the photosensitive layer having the o layer / m layer / u layer structure is 0.2 / 0.6 / 0.2 with respect to the total photosensitive layer thickness for convenience. To do.
In the above description, the photosensitive layer is composed of three layers. However, the photosensitive layer may be composed of two or more arbitrary layers depending on the purpose. The thickness of each layer is preferably 40 to 90% of the total photosensitive layer when the o layer and the u layer are considered as the cover layer of the m layer. 60% can be allocated.

The volume ratio of silver and binder contained in the photosensitive layers 51 and 61 formed on both surfaces of the transparent support of the present invention is preferably 1.0 or more, and more preferably 1.5 or more. By setting the volume ratio of silver and binder to 1.0 or more, the conductivity of developed silver after development processing can be increased. The volume ratio of silver and binder in the present invention is calculated by calculating the mass of silver and the mass of binder contained in the silver halide emulsion layer, assuming that the density of silver is 10.5 and the density of binder is 1.34. To ask for.
The volume ratio of silver and binder may be the same for all of the o layer / m layer / u layer and the photosensitive layers 51 and 61, but can be changed for each layer, and support of at least one of the photosensitive layers 51 or 61 is possible. The volume ratio of silver and binder contained in the u-layer photosensitive layer located close to the body is preferably less than 1.0, and more preferably less than 0.5. Furthermore, it is more preferable that the volume ratio of silver and binder contained in the o layer located far from the support of at least one photosensitive layer is less than 0.5.

(binder)
In the photosensitive layer containing a silver halide emulsion, a binder is used for the purpose of uniformly dispersing silver salt grains and assisting the adhesion between the emulsion layer and the support. Examples of the binder include polysaccharides such as gelatin, carrageenan, polyvinyl alcohol (PVA), polyvinyl pyrrolidone (PVP), starch, cellulose and derivatives thereof, polyethylene oxide, polysaccharides, polyvinylamine, chitosan, polylysine, and polyacrylic acid. , Polyalginic acid, polyhyaluronic acid, carboxycellulose, gum arabic, sodium alginate and the like, and gelatin is preferred.
As gelatin, lime-processed gelatin or acid-processed gelatin may be used, and gelatin hydrolyzate, gelatin enzyme decomposition product, and other gelatins modified with amino groups and carboxyl groups (phthalated gelatin, acetylated gelatin) are used. can do.
Moreover, latex can also be used as a binder. Here, as the latex, the polymer latex described in JP-A-2-103536, page 18, lower left column, lines 12 to 20 can be preferably used.

The solvent used for forming the photosensitive layer of the present invention is not particularly limited. For example, water, organic solvents (for example, alcohols such as methanol, ketones such as acetone, amides such as formamide, dimethyl sulfoxide, etc. Sulphoxides such as, esters such as ethyl acetate, ethers, etc.), ionic liquids, and mixed solvents thereof.
The content of the solvent used in the photosensitive layer is in the range of 30 to 90% by mass and preferably in the range of 50 to 80% by mass with respect to the total mass of the silver salt and binder contained in the photosensitive layer. .

  There are no particular restrictions on the various additives used in the present embodiment, and known ones can be preferably used. For example, various matting agents can be used, and thereby the surface roughness can be controlled. The matting agent is preferably made of a material that remains after development processing and does not impair the transparency and dissolves in the processing step.

(Other layer structure)
A protective layer (not shown) may be provided on the photosensitive layer of the present invention. In the present embodiment, the “protective layer” means a layer composed of a binder such as gelatin or a high molecular polymer, and is formed on a photosensitive layer having photosensitivity in order to exhibit an effect of preventing scratches or improving mechanical properties. The The thickness is preferably 0.5 μm or less. The coating method and forming method of the protective layer are not particularly limited, and a known coating method and forming method can be appropriately selected.
Antihalation layers 57 and 67 can be provided between the photosensitive layer of the present invention and the transparent support. Regarding the material used for the antihalation layer and the method of using the same, the description in paragraphs 29 to 32 of JP-A-2009-188360 can be referred to. The optical density of the antihalation layer varies depending on the intensity and wavelength of exposure light, but is preferably about 0.5 to 3.0.

Next, a process for producing the transparent conductive sheet of the present invention using the material of the present invention described above will be described with reference to FIG.
4A shows a transparent support 32, and FIG. 4B shows a photosensitive material 05 of the present invention in which an upper photosensitive material layer 50 and a lower photosensitive material layer 60 are provided on both sides of the transparent support by coating. (C) shows a view of the light-sensitive material of the present invention exposed through a photomask, and (d) shows a developed silver electrode formed by a development-fixing process subsequent to exposure. Below, each process after exposure is demonstrated.
[exposure]
Since the photosensitive material 05 of the present invention is a photosensitive material having photosensitive layers formed on both sides of a support, in the present invention, light is irradiated 102a and 102b on both sides of the photosensitive material as shown in FIG. Exposure. Light irradiation is performed on the photosensitive material through photomasks 110 and 120. Since the photomasks 110 and 120 are masks used to form the electrode patterns shown in FIGS. 7 and 8 described later with developed silver, the photomasks 110 and 120 correspond to the thin lines of the electrodes shown in FIGS. 7 and 8. This is a mask that transmits light. Therefore, the photomasks 110 and 120 are not the same, but are masks with different patterns. As described above, 111 and 121 are mask openings, and 112 and 122 are mask light shielding portions. The light transmitted through the opening of the mask forms a latent image on the silver halide emulsion at portions 131 and 141 of the photosensitive layer. The portions 131 and 141 where the latent image is formed form a developed silver pattern by the next development process. In the unexposed portions 132 and 142 of the photosensitive material that are not exposed by the light shielding portion of the mask, the silver halide emulsion grains that are not exposed by the fixing process are dissolved and flow out of the layers to form transparent films 152 and 162.

As described above, when exposure is performed from both sides of the photosensitive material using masks having different patterns, the following problems occur. The light that has passed through the opening 111 of the photomask 110 forms a latent image on the portion 131 of the photosensitive material, but the excess light also passes through the transparent support, and the photosensitive layer 61 on the opposite surface also has an unexpected latent image. An image is formed. Such a problem is difficult only by adjusting the exposure amount, and can be dealt with by providing the photosensitive material with antihalation layers 57 and 67 having an optical density that absorbs light transmitted through the photosensitive layer 51. Another method is to change the color sensitivity of the silver halide emulsions of the photosensitive layers 51 and 61 with a sensitizing dye.
FIG. 5 is a model diagram of an exposure apparatus according to the present invention. The light from the two light sources 100a and 100b is converted into parallel light by the lens, and both surfaces of the photosensitive material are exposed through the mask. In the exposure apparatus unit including the light source to the photomask in FIG. 5, the positioning of the two exposure apparatuses is strictly performed. The silver image formed by the photomasks 110 and 120 having the patterns of FIG. 7 and FIG. 8 is precisely positioned so as to have a uniform pattern as shown in FIG. 10 to 12 in which the touch panel is configured by combining two conductive sheets, it is necessary to position the two conductive sheets for each set, compared to the double-sided type as in this case. Productivity is greatly inferior.
An electromagnetic wave can be used as a light source for exposure. Examples of the electromagnetic wave include light such as visible light and ultraviolet light, and radiation such as X-rays. Further, a light source having a wavelength distribution may be used for exposure, and a light source having a specific wavelength may be used.
The exposure method may be a surface exposure as shown in FIG. 5 or a surface exposure through a different mask. In addition, scanning exposure is preferable instead of using a mask as shown in FIG.
As described above, both the surface of the photosensitive material for producing a conductive sheet of the present invention are subjected to image-like pattern exposure, and then developed, whereby a front surface transparent electrode composed of developed thin conductive silver wires and development. Backside transparent electrodes made of silver conductive fine wires can be formed on both sides of the transparent support.
In addition, the conductive sheet formed as described above is exposed so that the conduction direction of the front transparent electrode and the conduction direction of the back transparent electrode are orthogonal to each other, and then developed. It is formed.

(Development processing)
In this embodiment, after the photosensitive layer is exposed, further development processing is performed. The development processing can be performed by a normal development processing technique used for silver salt photographic film, photographic paper, printing plate-making film, photomask emulsion mask, and the like. The developer is not particularly limited, but a PQ developer, MQ developer, MAA developer and the like can also be used. Commercially available products include, for example, CN-16, CR-56, CP45X, and FD prescribed by FUJIFILM Corporation. -3, Papitol, a developer such as C-41, E-6, RA-4, D-19, D-72, etc. formulated by KODAK, or a developer included in the kit can be used. A lith developer can also be used.
The development processing in the present invention can include a fixing processing performed for the purpose of removing and stabilizing the silver salt in the unexposed portion. For the fixing process in the present invention, a fixing process 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 fixing temperature in the fixing step is preferably about 20 ° C. to about 50 ° C., more preferably 25 to 45 ° C. The fixing time is preferably 5 seconds to 1 minute, more preferably 7 seconds to 50 seconds. The replenishing amount of the fixing solution is preferably 600 ml / ^{m 2} or less with respect to the processing of the photosensitive material 122, more preferably 500 ml / ^{m 2} or less, 300 ml / ^{m 2} or less is particularly preferred.
The photosensitive material 122 that has been subjected to development and fixing processing is preferably subjected to water washing processing and stabilization processing. In the water washing treatment or the stabilization treatment, the washing water amount is usually 20 liters or less per 1 m ^{2 of the} light-sensitive material, and can be replenished in 3 liters or less (including 0, ie, rinsing with water).
The mass of the metallic silver contained in the exposed portion (conductive pattern) after the development treatment is preferably a content of 50% by mass or more with respect to the mass of silver contained in the exposed portion before the exposure, and 80 mass. % Or more is more preferable. 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 gradation after the development processing in the present embodiment is not particularly limited, but is preferably more than 4.0. When the gradation after the development processing exceeds 4.0, the conductivity of the conductive metal portion can be increased while keeping the light transmissive property of the light transmissive portion high. Examples of means for making the gradation exceed 4.0 include the aforementioned doping of rhodium ions and iridium ions, and the inclusion of a polyethylene oxide derivative in the developing solution.

(Hardening after development)
It is preferable to carry out the film hardening process by immersing the film in a hardening agent after developing the photosensitive layer. Examples of the hardener include dialdehydes such as potassium alum, glutaraldehyde, adipaldehyde, 2,3-dihydroxy-1,4-dioxane, and those described in JP-A-2-141279 such as boric acid. be able to.
A transparent conductive sheet is obtained through the above steps. The surface resistance of the obtained transparent conductive sheet is 0.1 to 100 ohm / sq. In the range of 1 to 50 ohm / sq. Is more preferably in the range of 1 to 10 ohm / sq. It is more preferable that it is in the range. In addition to the above, the unit of surface resistance is also expressed as Ω / □ or Ω / square.
Moreover, the volume low efficiency of the obtained transparent conductive sheet is preferably 160 μΩ · cm or less, more preferably in the range of 1.6 to 16 μΩ · cm, and 1.6 to 10 μΩ · cm. More preferably, it is in the range.

(Calendar processing)
In the manufacturing method of the present embodiment, a smoothing process is performed on the transparent conductive sheet that has been developed. This significantly increases the conductivity of the transparent conductive sheet. The smoothing process can be performed by, for example, a calendar roll. The calendar roll usually consists of a pair of rolls. Hereinafter, the smoothing process using the calendar roll is referred to as a calendar process.
As a roll used for the calendar process, a plastic roll or a metal roll such as epoxy, polyimide, polyamide, polyimide amide or the like is used. In particular, when emulsion layers are provided on both sides, it is preferable to treat with metal rolls. When an emulsion layer is provided on one side, a combination of a metal roll and a plastic roll can be used from the viewpoint of preventing wrinkles. The upper limit of the linear pressure is 1960 N / cm (200 kgf / cm, converted to a surface pressure of 699.4 kgf / cm ² ) or more, more preferably 2940 N / cm (300 kgf / cm, converted to a surface pressure of 935.8 kgf / cm ^2). ) That's it. The upper limit of the linear pressure is 6880 N / cm (700 kgf / cm) or less.
The application temperature of the smoothing treatment represented by the calender roll is preferably 10 ° C. (no temperature control) to 100 ° C., and the more preferable temperature varies depending on the line density and shape of the metal mesh pattern and metal wiring pattern, and the binder type. , Approximately 10 ° C. (no temperature control) to 50 ° C.

(Treatment in contact with steam)
In the manufacturing method of the present embodiment, the smoothed conductive pattern may be brought into contact with steam (steam contact process). In this vapor contact step, the smoothed transparent conductive sheet is brought into contact with superheated steam, and the smoothed conductive pattern 108 is brought into contact with pressurized steam (pressurized saturated steam); There is. Thereby, electroconductivity and transparency can be improved simply in a short time. It is considered that a part of the water-soluble binder is removed and the bonding sites between the metals (conductive substances) are increased.

(Washing treatment)
In the manufacturing method of this Embodiment, it is preferable to wash with water after making a transparent conductive sheet contact superheated steam or pressurized steam. By washing with water after the steam contact treatment, the binder dissolved or brittle with superheated steam or pressurized steam can be washed away, whereby the conductivity can be improved.

(Plating treatment)
In the present embodiment, the above-described smoothing process may be performed, or a plating process may be performed on the transparent conductive sheet. By plating, the surface resistance can be further reduced and the conductivity can be increased. The smoothing treatment may be performed either before or after the plating treatment. However, by performing the smoothing treatment before the plating treatment, the plating treatment is made efficient and a uniform plating layer is formed. The plating treatment may be electrolytic plating or electroless plating. Further, the constituent material of the plating layer is preferably a metal having sufficient conductivity, and copper is preferable.

(Oxidation treatment)
In the present embodiment, it is preferable to subject the transparent conductive sheet after the development treatment and the conductive metal portion formed by the plating treatment to an oxidation treatment. By performing the oxidation treatment, for example, when a metal is slightly deposited on the light transmissive portion, the metal can be removed and the light transmissive portion can be made almost 100% transparent.

The conductive sheet 10 made of conductive thin wires formed through the above process is a patterned electrode made of a plurality of conductive thin wires.
Next, the patterned electrode formed on the transparent support of the present invention will be described in relation to a capacitive touch panel in which the transparent conductive sheet of the present invention is preferably used. In the conventional capacitive type touch panel, an ITO thin film, which is a transparent electrode material, has been used as a bar electrode as an electrode material. However, in the present invention, an electrode is formed by a combination of conductive thin wires using a material having a resistance lower than that of ITO. This is called a patterned electrode.
As shown in FIG. 4D, the capacitive touch panel using the transparent conductive sheet of the present invention has an upper electrode (also referred to as a front surface electrode) 11 and a lower electrode on both surfaces of the transparent support 32. (Also referred to as back surface electrode) 12 is formed.
The upper electrode (also referred to as a front surface electrode) 11 has a pattern as shown in the upper diagram of FIG. 6, and each electrode includes a plurality of conductive grid portions 14 </ b> A for sensing capacitance, a grid and a grid. The conductive connecting portion 16A is connected, and the lead wire 18A is connected to the electrode and the external control portion. FIG. 7 is an enlarged view of the conductive grating portion 14A. In FIG. 7, the shape of the conductive lattice portion is described as a square lattice mesh shape. However, the shape is not necessarily a square lattice, and may be a rhombus or a rectangular lattice. The conductive lattice portion 14A is disposed around the square lattice composed of the conductive thin wires 21, the dummy thin wires 19 including a number of short lines, and the conductive lattice portion 14A connecting the conductive lattice portion 14A in the electrode direction. The connecting portion 16A is described. In order to prevent the electrode from functioning due to an unexpected disconnection failure, the conductive connecting portion 16A is connected not by a single thin line but by a plurality of thin lines.
The lower electrode (also referred to as the back surface electrode) 12 has a pattern as shown in the lower diagram of FIG. 6, and each electrode has a plurality of conductive grid portions 14 </ b> B that sense capacitance, and a conductivity that connects the grid and the grid. The connecting portion 16B and the lead wire 18B connecting the electrode and the external control portion. The description of FIG. 8 can be based on the description of the upper electrode 12.
The patterned electrode is preferably a conductive sheet having a square lattice or a rectangular lattice in the electrode by conductive thin wires.

FIG. 9 shows how the electrode lines appear when FIG. 6 is seen through from the toucher side. FIG. 9 using the upper conductive sheet 11 and the lower conductive sheet 12 of the present invention can form a uniform square lattice and constitute a panel that is easily visible. In FIG. 9, the lattice appears to be formed in a straight line, but there are a straight line part and a part composed of two short lines. This state is shown in an enlarged view of the portion marked with a circle in FIG. 9, and the solid line part on the left side represents a part of the conductive thin wire 21 of the conductive lattice part 14A of the upper conductive sheet. (21) is a dummy fine wire around the conductive grid portion 14A. Similarly, the dotted line portion on the right side represents a part of the conductive thin wire 22 of the conductive lattice portion 14B of the lower conductive sheet, and the dotted line 19 (22) is a dummy thin wire around the conductive lattice portion 14B. In this way, even though it looks visually as a single straight line, the conductive thin wires 21 and 22 are not actually connected, and the dummy thin wire 19 is not connected.
As can be understood from the above, the dummy thin wire 19 used in the present invention is a thin wire used for improving the visibility, and as described in FIGS. 7 and 8, the dummy thin wire is at both ends of the long wire of the square lattice. It is formed on the extension line of the part and is disconnected so as not to be electrically connected to the conductive grid part. It is preferable that the length of the dummy fine wire is ½ or less of the side length of the unit cell of the electrode portion.

Below, the upper conductive sheet 11 is taken as an example and the details of the electrodes will be described. The ITO diamond pattern, which has been used to form conventional electrodes, is difficult to apply to large screens because of its high ITO resistance value. In the present invention, the diamond portion is formed of a mesh or lattice made of low-resistance fine wires, and the diamond pattern is low. Resistance and screen brightness are guaranteed. Hereinafter, the description will be made using a square lattice, but this does not preclude the use of a rectangular lattice or the like.
The line width of the thin conductive wires forming the conductive lattice portion is preferably 1 μm or more and 10 μm or less, and more preferably 2 μm or more and 6 μm or less. When the thickness is in the range of 1 μm or more and 10 μm or less, a low-resistance electrode can be formed relatively easily.
The thickness of the conductive thin wire forming the conductive lattice portion is preferably 0.1 μm or more and 1.5 μm or less, and more preferably 0.2 μm or more and 0.8 μm or less. When the thickness is in the range of 0.1 μm or more and 1.5 μm or less, a low-resistance electrode that is excellent in durability can be formed relatively easily.

  The length of one side of the conductive grid portions 14A and 14B of the present invention is preferably 3 to 10 mm, and more preferably 4 to 6 mm. If the length of one side is 3 to 10 mm, it is difficult to cause problems such as a possibility of detection failure due to insufficient sensing capacitance and a decrease in position detection accuracy. From the same viewpoint, the length of one side of the unit cell constituting the conductive lattice part is preferably 50 to 500 μm, and more preferably 150 to 300 μm. When the length of the side of the unit cell is in the above range, the transparency can be further kept good, and the display can be visually recognized without a sense of incongruity when attached to the front surface of the display device.

Note that the upper and lower electrodes of the touch panel in FIG. 8 are substantially perpendicular to the conduction direction, but can be set to any angle as long as there is no hindrance in determining the coordinates of the touch position.
Furthermore, the direction of the conductive thin wires constituting the square lattice illustrated in FIGS. 7 and 8 is 45 ° with respect to the X and Y axes. The touch panel of the present invention has a feature that moire does not easily occur when the X and Y directions of the panel are bonded as the electrode axis direction of the image display device.

  The conductive sheet composed of the above patterned electrodes can significantly reduce the electric resistance as compared with a structure in which one electrode is formed by one ITO film. Accordingly, when the conductive sheet of the present invention is used, for example, when applied to a projected capacitive touch panel, the response speed can be increased, and an increase in the size of the touch panel can be promoted.

"Double-sided conductive sheet with improved color difference"
As described in the means for solving the problems, the conductive sheet of the present invention is a color of the upper electrode and the lower electrode formed on both surfaces of a single transparent support used for improving productivity. The conductive sheet can reduce the difference.
The improvement of the color difference is that the electrode on the side far from the transparent support of the front surface electrode of the conductive sheet (also referred to as a double-sided conductive sheet) having an upper electrode and a lower electrode formed on both surfaces of a single transparent support. The absolute value of the difference between the reflected chromaticity b ₁ ^* of the surface and the reflected chromaticity b ₂ ^* of the electrode surface on the side close to the transparent support of the back electrode is 2 or less (| Δb ^* | = | b ₁ ^* This can be achieved by the transparent conductive sheet satisfying −b ₂ ^* | ≦ 2).
Moreover, it is preferable that the color tone when observed is easily visually recognized as black. The measured values of b ₁ ^* and b ₂ ^* are neutral in the vicinity of 0. However, in the present invention, when set as follows, the viewer can easily recognize black. In the present invention, b ₁ ^* is preferably −2.0 <b ₁ ^* ≦ 0, more preferably −1.5 <b ₁ ^* ≦ −0.3, and −1.0 <b ₁ ^* ≦ -0.5 is particularly preferred.
As b ₂ ^* , −1.0 <b ₂ ^* ≦ 1.0 is preferable, −0.7 <b ₂ ^* ≦ 0.5 is more preferable, and −0.5 <b ₂ ^* ≦ 0.2 is satisfied. Particularly preferred.
The combination of b ₁ ^* and b ₂ ^* is preferably −2.0 <b ₁ ^* ≦ 0 and −1.0 <b ₂ ^* ≦ 1.0, and −1.5 <b ₁ ^* ≦ −0.3 and −0.7 <b ₂ ^* ≦ 0.5 are more preferable, −1.0 <b ₁ ^* ≦ −0.5, and −0.5 <b ₂ ^* ≦ 0.2 Is particularly preferred.
By doing so, it is possible to eliminate the color unevenness on the electrode surface and to make it feel a black tone (neutral), and the visibility is further improved.
Here, the reflection chromaticity b ₁ ^* of the electrode surface far from the transparent support of the front electrode is the reflection chromaticity of the electrode surface in the region d2 in FIG. B ^* value when measured from the side. Further, the reflection chromaticity b ₂ ^* of the electrode surface on the side close to the transparent support of the back surface electrode is a measurement of the reflection chromaticity of the electrode surface in the region d3 in FIG. 2 from the viewer side at the top of the figure. This is the b ^* value.

The reflection chromaticity b ^* is a characteristic value defined by the L ^* a ^* b ^* color system. The L ^* a ^* b ^* color system is a color specification method defined by the International Commission on Illumination (CIE) in 1976, and the L ^* value, a ^* value, and b ^* value in the present invention are JIS- Z8729: A value obtained by measurement by the method defined in 1994. As a measuring method of JIS-Z8729, there are a measuring method by reflection and a measuring method by transmission. In the present invention, a value measured by reflection is used.
L ^* a ^* b ^* L ^* values in a color system, a ^* value, b ^* value, as is well known, L ^* value is brightness, and the a ^* value and b ^* value, hue and chroma Represents degrees. Specifically, if the a ^* value has a positive sign, it indicates a red hue, and if it has a negative sign, it indicates a green hue. If the b ^* value is positive, the hue is yellow, and if it is negative, the hue is blue. Further, for both the a ^* value and the b ^* value, the larger the absolute value, the larger the saturation of the color, and the brighter the color, and the smaller the absolute value, the smaller the saturation.
In the present invention, a ^* value is less change in the viewing direction (b ₁ direction and the b ₂ direction). On the other hand, the b ^* value has a greater change depending on the viewing direction of the electrode than the a ^* value. Specifically, the b ^* value moves easily from yellow to blue or vice versa and is easily recognized as color unevenness. Details of the measurement method are described in the Examples section.

The improvement of the color of the electrode surface of the above double-sided conductive sheet has been achieved by the photosensitive material of the present invention already described.
Below, the outline of the preferred embodiments of the respective layers of the photosensitive layer for adjusting the reflection chromaticity will be briefly described. In the system in which the silver amount is increased for the purpose of lowering the resistance as in the present invention, and the silver density is increased in order to impart conductivity to the developed silver image, the transparent support for the developed silver electrode The color of the electrode surface far from the surface tends to be blue, and the color of the electrode surface near the transparent support of the developed silver electrode tends to be yellowish.
As a cause of this tint phenomenon, in a system with a large amount of silver and a high silver density, development proceeds with a fresh developer composition on the surface side as the developer permeates from the surface of the photosensitive layer far from the transparent support. On the other hand, as the developer penetrates into the photosensitive layer toward the lower layer, development fatigue substances accumulate, and the development inhibitor contained in the developer is consumed in the surface layer. It is considered that development with a liquid composition with less agent proceeds. Along with this, it is presumed that a difference occurs in the shape of the developed silver filament on the upper layer side (o layer side) / lower layer side (u layer side) of the light-sensitive material, and is observed as a chromaticity difference. Based on such estimation, preferred embodiments in the present invention have already been described in the items [1] to [30] in the means for solving the problems.

  The double-sided conductive sheet of the present invention is preferably used for a touch panel, particularly a capacitive touch panel.

In addition, this invention can be used in combination with the technique of the publication gazette and international publication pamphlet of following Table 1 suitably. Notations such as “JP,” “Gazette” and “No. Pamphlet” are omitted.
However, Japanese publications have hyphens after the year, as in 2004-221564, and international pamphlets have a slash after the year, as in 2006/001461.

  Hereinafter, the present invention will be described more specifically with reference to examples of the present invention. In addition, the material, usage-amount, ratio, processing content, processing procedure, etc. which are shown in the following Examples can be changed suitably unless it deviates from the meaning of this invention. Accordingly, the scope of the present invention should not be construed as being limited by the specific examples shown below.

Example 1
(Preparation of 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 added simultaneously over 20 minutes with stirring to form 0.16 μm core particles. Subsequently, the following 4 liquid and 5 liquid were added over 8 minutes, and the remaining 10% of the following 2 liquid and 3 liquid were further 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 grain formation.

1 liquid:
750 ml of water
Gelatin (phthalated gelatin) 8g
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
Hexachloroiridium (III) potassium (0.005% KCl 20% aqueous solution) 5 ml
Ammonium hexachlororhodate (0.001% NaCl 20% aqueous solution) 7 ml
4 liquids:
100ml water
Silver nitrate 50g
5 liquids:
100ml water
Sodium chloride 13g
Potassium bromide 11g
Yellow blood salt 5mg

  Then, it washed with water by the flocculation method according to a conventional method. Specifically, the temperature was lowered to 35 ° C., 3 liters of distilled water was added, and then 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 process. The emulsion after washing and desalting is adjusted to pH 6.4 and pAg 7.5, and 10 mg of sodium benzenethiosulfonate, 3 mg of sodium benzenethiosulfinate, 15 mg of sodium thiosulfate and 10 mg of chloroauric acid are added. And 1,3,3a, 7-tetraazaindene (100 mg) as a stabilizer and 100 mg of proxel (trade name, manufactured by ICI Co., Ltd.) as a preservative were added. 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 coating solution)
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 / Mol Ag, 2,4-dichloro-6-hydroxy-1,3,5-triazine sodium salt 0.90 g / mol Ag, a trace amount of hardener was added, and the coating solution pH was adjusted to 5.6 using citric acid. To prepare a photosensitive layer coating solution. Using the composition of the photosensitive layer coating solution as a reference, the amount of gelatin added is adjusted so that the volume ratio of silver and binder shown in Table 2 is obtained, and the type and amount of mercapto compound are changed, so that the front three layers A coating solution of (u layer, m layer, o layer) and three back surfaces (u layer, m layer, o layer) was prepared.

A dye that undergoes corona discharge treatment on both sides of a 100 μm polyethylene terephthalate (PET) film, then has a 0.1 μm thick gelatin undercoat layer, and further has an optical density of about 1.0 on the undercoat layer and decolorizes with an alkali of the developer. An antihalation layer containing was provided on both sides to form a support. The photosensitive layer coating solution prepared and prepared above was applied to both surfaces of this support.
The coating amount is set based on the silver amount, and the total amount of silver contained in the three photosensitive layers (u layer, m layer, o layer) is the developed silver image thickness (unit: μm) in Tables 2 and 3. It was made to become. In this case, the developed silver image thickness is calculated on the assumption that all silver salts in the coated emulsion are converted to developed silver, and the density of the developed silver (representing the silver / binder volume ratio) is 10.5. The film thickness of each layer of the photosensitive layers (u layer, m layer, o layer) is as shown in Table 3 for photosensitive materials 16-31 so that the film thickness is 1: 2: 1 for photosensitive materials 1-15. It was set so that the film thickness ratio entered in () of the silver density row of values was obtained. When the value in () is 1, it represents the case of a single layer, and 0.2 represents that the film thickness of that layer is 20% of the entire photosensitive layer.
Accordingly, in Table 3, the total thickness of the silver and the binder in the three photosensitive layers is determined on the other surfaces except the front surface and the back surface of the photosensitive material 19 and the front surface of the photosensitive material 31. The silver and the binder each have a thickness of 0.7 μm, and the silver and the binder each have a thickness of 1.5 μm on the front surface of the photosensitive material 31.
The front surface and the back surface of the photosensitive material 19 and the front surface and the back surface of the photosensitive material 16 are the same except for the silver / binder volume ratio of the o layer. That is, both o layers have the same coating thickness of the binder, but differ only in the thickness of silver. In the comparison between the photosensitive materials 19 and 18, in the photosensitive material 18, the reduction amount of silver and the increase amount of the binder caused by setting the silver / binder volume ratio of the o layer to 0.3 are adjusted in the m layer. On the other hand, the photosensitive material 19 does not adjust the decrease in the silver amount in the o layer, so that the developed silver image in Table 3 is thinner than the other photosensitive materials.
The silver bromide content of the emulsion is shown in Table 3 for photosensitive materials 1 to 15 in which all layers were 30 mol%.
As described above, the volume ratio of silver and binder in Table 2 was converted to volume assuming that the density of developed silver was 10.5 and the density of the binder was 1.34. The density of 1.34 is a density applicable to gelatin. When using other polymer compounds, conversion according to the compound is necessary.
Moreover, the addition amount of the mercapto compound added to the photosensitive layer coating solution was expressed as mg addition amount of mercapto with respect to 1 g of silver. The structure of the mercapto compound used is described after Table 3.
Further, a protective layer having a thickness of 0.15 μm made of gelatin containing a preservative was provided on the o layer. The three photosensitive layers and the four protective layers were coated using a simultaneous coating machine to prepare photosensitive materials 1 to 31.

(Exposure and development processing)
Next, the photosensitive materials 1 to 31 prepared above were subjected to double-sided exposure using the double-sided exposure machine shown in FIG. A high pressure mercury lamp was used as the light source, and exposure was performed using the pattern formation mask of FIG. 7 as the front side photomask and the pattern formation mask of FIG. 8 as the back side photomask. . The light transmission windows of the mask used have the same pattern as in FIGS. 7 and 8, respectively. The line width of the unit square lattice forming the lattice is 3 μm, and the side length of the lattice is 300 μm.
After the exposure, development is performed with the following developer, and further development processing is performed using a fixing solution (trade name: N3X-R for CN16X: manufactured by Fuji Photo Film Co., Ltd.), followed by rinsing with pure water and drying. The obtained sample was calendered to obtain a double-sided electrode type transparent conductive sheet 1. Similarly, double-sided electrode type transparent conductive sheets 2 to 31 were obtained.

The processing flow is as follows.
[Processing Flow] Processing machine: Fujifilm automatic processing machine (FG-710PTS)
Processing conditions: development is at 35 ° C. for 30 seconds,
Fixing is at 34 ° C for 23 seconds.
Washing with water is 20 seconds of running water (5 L / min).

(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

(Create touch panel)
A polyethylene terephthalate film having a thickness of 300 μm was attached to the front surface side of the double-sided electrode type transparent conductive sheet 1 obtained by the above development treatment using an adhesive. Moreover, the glass plate of thickness 3mm was bonded together to the back surface side of the transparent conductive sheet 1 with the adhesive, and the touch panel of the comparative example 1 was created. A touch panel of Comparative Examples 2 and 3 and a touch panel of Examples 1 to 28 were prepared in the same manner as Comparative Example 1 except that the transparent conductive sheets 2 to 31 were used instead of the transparent conductive sheet 1.

(Evaluation)
The following evaluation was performed using the double-sided electrode type transparent conductive sheets 1 to 31 created above.
(1) Measurement of reflection chromaticity b ₁ ^* and b ₂ ^* A sample for measurement is placed on a BCRA black tile (glossy plate), irradiated from 0 ° direction, and spectral reflectance of light received in 45 ° direction. Measure. Preferred tile is Sakata Engineering BCRA black tiles Co., Ltd. (gloss plate), the reflection chromaticity of the black tile, L ^* is 3.6, ^{a *} is -0.9, b ^* -0.6 It is. As the reflection densitometer, Spectro Eye LT manufactured by GretagMacbeth (Gretag Macbeth) can be used.
The reflection chromaticity measurement sample is not an ordinary mask for pattern exposure, but the front surface exposure mask 110 uses a mask having a window having a size capable of measuring reflection chromaticity. For the back surface exposure, the entire surface was exposed without using a mask. The reflection chromaticity is measured from the front surface side, and the reflection chromaticity b ₁ ^* of the exposed portion of the front surface where the silver image is formed is defined as reflection chromaticity b ₁ ^* , and the front surface is not exposed. was a reflection chromaticity measured reflection chromaticity b ₂ ^*, and the resulting reflected chromaticity b ₁ ^*, from the reflection chromaticity b ₂ ^*, the absolute value of the difference △ b ^* (Δb ^* represent also) calculated did.

(2) Visibility evaluation Observe the created double-sided electrode type transparent conductive sheet in the vertical direction and oblique directions in each direction, and perform sensory evaluations such as uneven color of reflected light, fluctuation of reflected light, and outline of electrode Went like that.
Evaluation ◎ Not concerned at all.
Evaluation ○ Level that hardly recognizes color.
Evaluation △ Level that can be visually recognized without a sense of incongruity even if there is color.
Evaluation × I am interested.

(3) Evaluation of conductivity The resistance value of the electrode of the transparent conductive sheet was directly read and evaluated based on the resistance value of the electrode on the front surface and the electrode on the back surface of Comparative Example 1.
Evaluation: The resistance value is clearly lower than that of Comparative Example 1. The surface resistance value is less than 20Ω / □.
Evaluation ○ Almost same as the resistance value of Comparative Example 1. The surface resistance value is 20Ω / □ or more and 50Ω / □ or less.
Evaluation x Inferior to the resistance value of Comparative Example 1 for some reason. The surface resistance value exceeds 50Ω / □.
The above results are summarized in Table 2 and Table 3 below.

From the results of Table 2 above, the following can be understood.
The double-sided electrode type transparent conductive sheet of Comparative Example 1 that does not use a mercapto compound for either the front surface or the back surface of the photosensitive layer has a sufficient resistance value as an electrode constituting a capacitive touch panel. Unevenness of taste is observed and visibility is poor. In order to further reduce the resistance, when the volume ratio of silver and binder is increased as in Comparative Examples 2 and 3, that is, the silver density is increased, the color unevenness is further deteriorated.
On the other hand, in Examples 1 to 12 using the mercapto compound for the photosensitive layer on either the front surface or the back surface, the color unevenness can be reduced without increasing the resistance value compared to the comparative example. Visibility has been improved.
The surface using the mercapto compound is added only to the back surface in this experiment, but the back surface is preferably added. Among the back surfaces, it is preferable to add to the u layer, which is a photosensitive layer close to the support, and as can be seen from the comparison between Example 1 and Example 11 or the comparison between Example 5 and Example 12, It can be seen that the mercapto compound is preferably localized in a lower layer (that is, a layer close to the support).
In addition, the effect of improving the color tone varies depending on the type of mercapto compound, and in Examples 7 to 9 using the monocyclic mercapto compounds C, D, and E, the color improvement is achieved with respect to Comparative Example 1 in which no mercapto compound is used. The effect of is negligible.
On the other hand, Examples 1, 4 to 6 using compounds A, B, F, and G, which are condensed ring compounds, show a significant improvement effect of uneven color, especially from the 4-position to the 7-position of 2-mercaptobenzimidazole. It turns out that Example 1 and 5 using the compounds F and G which have a sulfo group and a carboxyl group are preferable.
Further, in Example 3 in which the silver density was set to 2 for further lowering the resistance and the compound F was added to the back side photosensitive layer u, the color unevenness was small, and the reduction in resistance was realized.
Example 10 is an example in which the mercapto compound F is added to the photosensitive layer on the back side and the silver image thickness is increased from 0.7 to 1.5, but the resistance of the lower layer electrode of the touch panel is reduced. This indicates that the capacitance sensing ability can be improved and the unevenness of the color of the electrode when visually recognized can be improved.

Furthermore, the results of Table 3 show the following.
Examples 1 to 12 in Table 2 above use a silver chlorobromide emulsion containing 30 mol% of silver bromide in the silver halide emulsion, and have a photosensitive layer having a constant volume ratio (silver density) of silver and binder. In contrast to the constitutional example in which the mercapto compound is contained in the layer (u layer) close to the support of the photosensitive layer, Examples 13 to 28 in Table 3 have a silver bromide content of 50 mol% or Changed to 70 mol%, or changed the volume ratio (silver density) of silver and binder in the photosensitive layer in the thickness direction of the photosensitive layer (changed the silver density of specific layers of the o layer, m layer and u layer) ) This is an example of an electrode and a touch panel formed using a photosensitive material. Compared with Examples 1 to 12, the result of the absolute value | Δb ^* | of the difference in reflection chromaticity and the visibility are improved.

Examples 13 to 19 are characterized in that a double-sided conductive sheet formed of the same photosensitive material is used for the electrodes on both sides of the transparent support. All of these samples are characterized in that the color to be observed does not change even if the direction of observing the conductive sheet is changed, it is easy to identify on the touch panel formation, even if the front and back sides are wrong There is an advantage of not causing a problem.
Examples 13 to 16 all have the same addition of the development inhibitor F (mercapto compound) of the present invention to the layer (u layer) on the side close to the transparent support among the photosensitive layers on both sides. Samples 13 and 14 are samples in which the silver bromide ratio in all layers is changed from 30 mol% to 50 mol% or 70 mol%. Examples 15 and 16 are samples in which the silver o / a sample changed the volume ratio from 1.0 to 0.3 of the binder, the absolute value of the difference of the reflection chromaticity (| △ b ^* |, or | [Delta] b ^* | denote also), visibility, entirely conductive A problem-free sample was obtained.
Example 15 is a sample adjusted so as to keep the average silver / binder volume ratio of the entire photosensitive layer at 1.0. On the other hand, Example 16 is an unadjusted sample, and since the amount of silver in the o layer is reduced, the thickness of the developed silver image is reduced. In the comparison between Examples 15 and 16, no substantial difference was observed except that the resistance value of the sample of Example 16 was slightly high. From this, in order to ensure conductivity, the silver / binder volume ratio of the layer contributing to conductivity needs to be 1.0 or more. However, as in Example 16, it contributes to conductivity. If the silver / binder volume ratio of the main layer (m and u layers in Example 16) is 1.0 or more, a layer that contributes little to the conductivity for improving the tint can be provided. The thickness of the layer that contributes little to conductivity is preferably 50% or less, more preferably 30% or less, of the total thickness of the layer containing silver.
Examples 17 to 19 are samples in which the silver bromide ratio in all layers is increased, the volume ratio of silver / binder in the o layer is decreased, and the u layer addition of the development inhibitor F is combined. This sample is on the bluish side. By combining the above three requirements, a desired non-uniform color can be obtained.

Examples 20 to 28 are characterized in that double-sided conductive sheets formed from photosensitive materials having different electrode designs on both sides of the transparent support are used (also referred to as asymmetric type). All of these samples have an advantage that the color of the front surface electrode and the back surface electrode can be controlled independently, that is, the optimal values can be independently achieved.
In Examples 20 to 28, the addition of the development inhibitor, the content of silver bromide, and the volume ratio of silver / binder were changed on the front surface, the back surface, the o layer, or the u layer. , B ₁ ^* and b ₂ ^* can be changed, and in Examples 27 and 28, it was found that | Δb ^* | could be controlled to 0.5 or less. However, these samples may have large color unevenness observed from the opposite surface, and it is necessary to avoid troubles when creating the touch panel by the surface markings.
From the above results, it can be seen that | Δb ^* | is preferably 2 or less, more preferably 1 or less.
It can also be seen that the most preferable combinations of b ₁ ^* and b ₂ ^* are −1.0 <b ₁ ^* ≦ −0.5 and −0.5 <b ₂ ^* ≦ 0.2.

  The transparent conductive sheets 4 to 31 used in Examples 1 to 28 have a resistance value of 50Ω / □ or less and can be used as an electromagnetic wave shielding film. It was also found that the color tone was excellent even when used as an electromagnetic shielding film.

01 Touch panel 05 Photosensitive material 10 for producing a transparent conductive sheet Transparent conductive sheet (also referred to as a double-sided conductive sheet)
11 Upper electrode (front surface electrode)
12 Lower electrode (back surface electrode)
14A, 14B A plurality of conductive grating parts 16A, 16B for sensing electrostatic capacitance. Conductive connecting parts 18A, 18B connecting the grids and the grids. Lead wires 19 connecting the electrodes and the external control unit 19. Dummy thin wires 21. Conductors constituting the upper electrode. Conductive fine wire 22 Conductive fine wires 30 and 31 constituting the lower electrode Transparent support 32 also serving as the touch surface Transparent support 33 for the conductive sheet Transparent support 41 and 42 Adhesive layer 50 also serving as the insulating layer Upper photosensitive material layer (mainly Surface photosensitive material layer)
51 Upper photosensitive layer (front surface photosensitive layer)
52 Upper first photosensitive layer (upper u layer)
53 Upper second photosensitive layer (upper m layer)
54 Upper third photosensitive layer (upper o layer)
55 Upper protective layer 56 Upper undercoat layer 57 Upper antihalation layer 60 Lower photosensitive material layer (back side photosensitive material layer)
61 Lower photosensitive layer (back side photosensitive layer)
62 Lower first photosensitive layer (lower u layer)
63 Lower second photosensitive layer (lower m layer)
64 Lower third photosensitive layer (lower o layer)
65 Lower protective layer 66 Lower undercoat layer 67 Lower antihalation layers 100a and 100b Light sources a and b for exposure
101a, 101b Exposure lenses a and b
102a, 102b Parallel light a and b for exposure
110 Photomask 120 used for forming upper electrode (front surface electrode) 120 Photomask 111, 121 used for forming lower electrode (back surface electrode) Light transmitting portion 112, 122 Photomask light shielding portion 131 141 Exposed part in photosensitive layer (part where latent image is formed)
132, 142 Parts of the photosensitive layer that were not exposed (parts where no latent image was formed)
151 (21) Silver fine wire of the upper electrode formed after development processing (conductive thin wire constituting the upper electrode)
161 (22) Silver thin wire of the lower electrode formed after development processing (conductive thin wire constituting the lower electrode)
152, 162 Transparent layer b1 from which unexposed silver halide emulsion or the like has been removed by development processing b1 Direction to view conductive thin wire 21 b2 Direction to view conductive thin wire 22 d, d1 Repeat distance of upper and lower electrode thin wires ( pitch)
d2 Region where the conductive thin wires of the upper electrode are continuously arranged d3 Region where the conductive thin wires of the lower electrode are continuously arranged

Claims (10)

A photosensitive material for producing a conductive sheet, in which a photosensitive layer containing a silver halide emulsion is formed on both sides (a front side and a back side) of a transparent support, respectively, wherein the front side photosensitive layer or the back side is provided. photosensitive layer of at least one side of the photosensitive layer surface is observed containing a mercapto compound,
The photosensitive material for producing a conductive sheet is characterized in that the mercapto compound contained in the photosensitive layer is contained more in the photosensitive layer closer to the transparent support than in the photosensitive layer far from the transparent support of the photosensitive layer. . 2. The photosensitive material for producing a conductive sheet according to claim 1, wherein the photosensitive layer on either the front surface or the back surface of the transparent support does not contain a mercapto compound. 2. The photosensitive sheet for producing a conductive sheet according to claim 1, wherein the amount of mercapto compound contained in the photosensitive layer on the back surface is greater than the amount of mercapto compound contained in the photosensitive layer on the front surface of the transparent support. material. The amount of the mercapto compound contained in at least one photosensitive layer of the photosensitive layer is 0.1 mg or more and 15 mg or less with respect to 1 g (gram) of silver in the silver halide emulsion contained in the same layer as the mercapto compound. conductive sheet for producing light-sensitive material as described in any one of claims 1 to 3, characterized in that. The photosensitive sheet manufacturing photosensitive material according to any one of claims 1 to 4 , wherein the volume ratio of silver and binder contained in the photosensitive layer formed on both surfaces of the transparent support is 1.0 or more. material. The photosensitive layer on both sides of the transparent support has an antihalation layer between the transparent support and the respective photosensitive layers, for producing a conductive sheet according to any one of claims 1 to 5 . Photosensitive material. A front surface transparent electrode comprising conductive thin wires of developed silver by subjecting both surfaces of the photosensitive material for producing a conductive sheet according to any one of claims 1 to 6 to imagewise pattern exposure and subsequent development processing. And a backside transparent electrode made of developed fine conductive silver wires on both sides of the transparent support. The conductive direction according to claim 7 , wherein the conductive direction of the front surface transparent electrode and the conductive direction of the back surface transparent electrode are formed by being exposed and developed so as to be orthogonal to each other. Sheet. The absolute value of the difference between the reflection chromaticity b ₁ ^* of the electrode surface on the side far from the transparent support of the front surface electrode and the reflection chromaticity b ₂ ^* of the electrode surface on the side close to the transparent support of the back surface electrode Is 2 or less (| Δb ^* | = | b ₁ ^* −b ₂ ^* | ≦ 2), the transparent conductive sheet according to claim 7 or 8 . A capacitive touch panel using the transparent conductive sheet according to any one of claims 7 to 9 .

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