JP2012218402A - Transparent conductive sheet, photosensitive material for manufacturing the same, method of manufacturing the transparent conductive sheet, and capacitance type touch panel using the transparent conductive sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve visibility (shade irregularity or the like) when a conductive sheet is used in an image display device by reducing difference of a shade of a conductive pattern of a transparent conductive sheet.SOLUTION: In this transparent conductive sheet of a double-sided conductive pattern type, conductive layers each formed of a conductive fine wire are formed on both surfaces of a transparent support body. In the transparent conductive sheet of a double-sided conductive pattern type, the conductive layer at least on one-side surface of the conductive layers on both the surfaces includes a part high in density of a metal constituting the conductive fine wire, and a part low in density of the metal.

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. In increasing the size of the panel, it is essential to reduce the resistance of the conductive layer. 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 the alignment of the two electrodes, and the alignment is performed with high accuracy for each touch panel, and there is a problem that productivity of the touch panel is inferior.

In recent years, in order to simplify the positioning at the time of bonding of two conductive sheets (electrodes), a method of forming a conductive pattern on both sides of the back of one transparent support has been attempted. Since the conductive patterns (electrodes) made of conductive thin wires formed on the front and back surfaces of the transparent support must be visually recognized as a uniform pattern as shown in FIG. 8 of Patent Document 1, a photosensitive material is used as a conductive pattern forming material. It is considered that a method of forming a conductive pattern by exposure from both sides and subsequent development processing is advantageous.
However, in the sample in which electrodes are formed on both the front and back surfaces of the transparent support, the exposure pattern is precisely aligned so that the fluoroscopic images of the front and back electrodes have a uniform pattern. However, it was found that subtle color unevenness occurs. In addition, the phenomenon that the color of the formed electrode surface changes depending on the conditions under which the electrode is formed is also observed in a method of printing a conductive ink such as a silver paste, or a method using vapor deposition or sputtering, It may be observed when a thick electrode is formed.

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

The present invention has been made in consideration of the above problems, and an object thereof is to provide a transparent conductive sheet in which the color tone of the surface of the conductive pattern is controlled. A further object of the present invention is to provide a transparent conductive sheet in which the color tone of a conductive pattern 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 conductive patterns. Furthermore, an object of the present invention is to provide a conductive sheet that controls the color tone of a conductive pattern and has a low resistance and can be used for a large-screen touch panel. Furthermore, another object of the present invention is to provide a conductive sheet that can be used for an electromagnetic wave shield whose color tone is controlled.
In the conductive sheet of the present invention, a “conductive pattern made of conductive thin wires” is used for various purposes, so it is simplified and referred to as a “conductive pattern”. However, when used for electrode applications such as a touch panel, it is easy to understand. Prioritize the use of “conductive pattern” and “electrode”.

  The inventors of the present invention are more likely to observe the unevenness of the color as the thickness of the electrode is increased, and that two conductive sheets are used, and the observer visually recognizes the same side surface of the two conductive sheets. In this case, color unevenness is not observed, and it is easy to observe when the observer sees the electrode surface far from the support and the electrode surface close to the support as in the present case. It was found that the color observed through the support and the color observed from the surface of the conductive film differed not only in the case of forming with a fine pattern but also in the sample in which a uniform conductive film was formed on the support. Based on these facts, the color of the reflected light is different between the initial film surface of the electrode formation process and the surface of the electrode that has become thicker as the process progresses due to the difference in the metal microstructure of the conductive material. Were estimated to be different, leading to the following aspects of the invention.

1) A transparent conductive sheet in which conductive layers made of conductive thin wires are formed on both surfaces of a transparent support, wherein at least one of the conductive layers on both sides has a high density of metal constituting the conductive thin wires; A transparent conductive sheet having a low portion.
2) In item 1, when the density of the metal itself is ρ, the high metal density is 0.41ρ or more, and the low metal density is 0.33ρ or less. Sheet.
3) The transparent conductive sheet is subjected to pattern exposure and development treatment on a photosensitive material in which a photosensitive layer containing a silver halide emulsion is formed on both sides of a transparent support. A transparent conductive sheet in which a layer is formed on both sides of a transparent support, wherein a conductive layer on at least one side of the conductive layers on both sides has a portion with a high developed silver density and a portion with a low developed silver density. Item 3. The transparent conductive sheet according to Item 1 or 2, wherein
4) The transparent conductive sheet according to item 3 is such that the silver density on the side close to the transparent support of the developed silver fine wire formed on one side of the transparent support is lower than the average density of silver in the fine wire. A transparent conductive sheet, wherein the silver density on the side farther from the transparent support of the developed silver fine wire formed on the other surface is lower than the average density of silver in the fine wire.
5) The photosensitive material is a photosensitive material in which a photosensitive layer containing a silver halide emulsion is formed on both surfaces of a transparent support, and the photosensitive material formed on either the front surface or the back surface. Item 5. The photosensitive layer according to item 3 or 4, wherein the layer has a photosensitive layer having a small volume ratio of silver and binder (silver volume / binder volume) and a photosensitive layer having a large volume ratio of silver and binder. material.
6) The light-sensitive material is a light-sensitive material in which a light-sensitive layer containing a silver halide emulsion is formed on both sides of a transparent support, and silver and a binder from one side of the transparent support close to the support surface. The photosensitive layer having a small volume ratio and a photosensitive layer having a large volume ratio of silver and binder are at least in this order, and the volume ratio of silver and binder is large from the side closer to the support surface on the other surface of the transparent support. Item 6. The photosensitive material according to any one of Items 3 to 5, comprising a photosensitive layer and a photosensitive layer having a small volume ratio of silver and binder in this order.
7) The coated silver amount of the photosensitive layer containing a silver halide emulsion formed on both surfaces of the transparent support is 4 g / m ² or more and 20 g / m ² or less, respectively. 2. The photosensitive material according to item 1.
8) A film in which the film thickness of the photosensitive layer having a small volume ratio of silver and binder is 10% or more and 40% or less with respect to the film thickness of the photosensitive layer containing the silver halide emulsion formed on both surfaces of the transparent support. Item 8. The photosensitive material according to any one of Items 3 to 7, which has a thickness.
9) The volume ratio of silver and binder in the photosensitive layer having a small volume ratio of silver and binder is 0.05 or more and 0.5 or less, and the volume ratio of silver and binder in the photosensitive layer having a large volume ratio of silver and binder. Item 9. The photosensitive material according to any one of Items 5 to 8, which is 0.7 or more.
10) The volume ratio of silver and binder in the photosensitive layer having a small volume ratio of silver and binder is from 0.1 to 0.4, and the volume ratio of silver to binder in the photosensitive layer having a large volume ratio of silver and binder. Item 10. The photosensitive material according to any one of Items 5 to 9, which is 1.0 or more.
11) The light-sensitive material contains a silver chlorobromide emulsion, and the silver bromide content of the silver chlorobromide emulsion of the photosensitive layer having a small volume ratio of silver and binder is a photosensitive layer having a large volume ratio of silver and binder. Item 11. The photosensitive material according to any one of Items 5 to 10, which is higher by 5 mol% or more than the silver bromide content of the silver chlorobromide emulsion.
12) The silver bromide content of the silver halide emulsion of the photosensitive layer having a small volume ratio of silver and binder is 40 mol% or more, and the bromide of the silver halide emulsion of the photosensitive layer having a large volume ratio of silver and binder. Item 12. The photosensitive material according to any one of Items 5 to 11, wherein the silver content is less than 40 mol%.
13) One of the photosensitive layers having a small volume ratio of silver and binder contains a development inhibitor, and the other of the photosensitive layers having a small volume ratio of silver and binder does not contain a development inhibitor. 2. The photosensitive material according to any one of the above.
14) The photosensitive material according to item 13, wherein the development inhibitor is a mercapto compound.
15) The photosensitive material according to item 13, wherein the development inhibitor is a compound capable of releasing the development inhibitor by development.
16) The photosensitive material according to any one of items 5 to 15, wherein the photosensitive material on both surfaces of the transparent support has an antihalation layer between the transparent support and each photosensitive layer.
17) The photosensitive material according to item 16, wherein the optical density of the antihalation layer is preferably about 0.5 to 3.0.
18) The photosensitive material according to any one of items 5 to 17, wherein an easy adhesion layer is provided between the transparent support and each antihalation layer.
19) The photosensitive material according to any one of items 5 to 18, wherein a protective layer is provided on the surface of the photosensitive layer.
20) The photosensitive material according to item 19, wherein the protective layer has a thickness of 0.5 μm or less.
21) The said pattern exposure is given from both surfaces of the photosensitive material of claim | item 5-20, The transparent conductive sheet characterized by the above-mentioned.
22) The pattern exposure is performed so that the conduction direction of the conductive pattern on one surface of the conductive layer formed on both surfaces of the support after the development processing is orthogonal to the conduction direction of the conductive pattern on the other surface. The transparent conductive sheet according to claim 21, wherein the transparent conductive sheet is formed.
23) The pattern exposure is adjusted so that a conductive layer pattern composed of developed thin conductive silver wires formed on both sides of a support after development processing can be regarded as a continuous pattern when seen through from one side. Item 23. The transparent conductive sheet according to Item 21 or 22, wherein
24) A capacitive touch panel using the transparent conductive sheet according to any one of items 21 to 23.
25) In the capacitive touch panel using the transparent conductive sheet according to Item 24, the reflection chromaticity b ^* value of the conductive pattern measured from the toucher side is the conductive pattern on the side close to the toucher of the double-sided conductive pattern. a reflection chromaticity b ₁ ^* a (front surface conductive pattern), when the reflection chromaticity b ₂ ^* of the conductive patterns of distant touch's side (back surface conductive pattern), a reflection chromaticity b ₁ ^*, A touch panel, wherein an absolute value of a difference from the reflection chromaticity b ₂ ^* is 2 or less (| Δb ^* | = | b ₁ ^* −b ₂ ^* | ≦ 2).
26) The touch panel according to item 25, wherein | Δb ^* | = | b ₁ ^* −b ₂ ^* | ≦ 1.
27) The touch panel according to Item 25 or 26, wherein the reflection chromaticity b ₁ ^* is −2.0 <b ₁ ^* ≦ 0.
28) The touch panel according to any one of Items 25 to 27, wherein the reflection chromaticity b ₂ ^* is −1.0 <b ₂ ^* ≦ 1.0.
29) Item 25, wherein the reflection chromaticities b ₁ ^* and b ₂ ^* satisfy −2.0 <b ₁ ^* ≦ 0 and −1.0 <b ₂ ^* ≦ 1.0. 28. The touch panel according to any one of 28.
30) The reflection chromaticity b ₁ ^* and b ₂ ^* are −1.0 <b ₁ ^* ≦ −0.5 and −0.5 <b ₂ ^* ≦ 0.2. Item 29. The touch panel according to any one of items 25 to 28.

  When a photosensitive material having a photosensitive material layer formed on both sides of the transparent support of the present invention is subjected to pattern exposure and development processing, an upper conductive pattern (upper electrode) and a lower conductive pattern (lower electrode) made of developed silver are formed on both sides of the transparent support. Electrode), the conductive sheet can be manufactured inexpensively and stably. Moreover, since the color tone of the upper conductive pattern and the lower conductive pattern can be improved, a conductive sheet that is easy to visually recognize can be obtained. Furthermore, since highly conductive silver is used for the conductive pattern material, a low-resistance conductive sheet can be obtained, which can be used for a heating element, an electromagnetic wave shield, and the like, and in particular, a touch panel having a large screen suitability can be obtained.

It is sectional drawing of the model of the touchscreen which formed the conductive pattern on both surfaces of the transparent support body. It is sectional drawing of the transparent conductive sheet model of this invention which formed the conductive pattern on both surfaces of the transparent support body. It is sectional drawing of another transparent conductive sheet model of this invention which formed the conductive pattern on both surfaces of the transparent support body. It is sectional drawing of the conventional transparent conductive sheet model which formed the conductive pattern on both surfaces of the transparent support body. It is a perspective view of the upper conductive pattern 11 and the lower conductive pattern 12 formed on both surfaces of the transparent support. It is a figure explaining the electroconductive grating | lattice part and connection part of the upper conductive pattern of FIG. It is a figure explaining the electroconductive grating | lattice part and connection part of the lower conductive pattern of FIG. It is a perspective view when an upper conductive pattern and a lower conductive pattern are viewed from the toucher side. It is sectional drawing of the photosensitive material used in order to manufacture the transparent conductive sheet of this invention. It is another sectional drawing of the photosensitive material used in order to manufacture the transparent conductive sheet of this invention. It is sectional drawing of the photosensitive material used in order to manufacture the conventional transparent conductive sheet. It is the figure which showed the process which manufactures the transparent conductive sheet which formed the conductive pattern 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. It is a schematic diagram of the touch panel which laminated | stacked two conventional conductive sheets. It is another schematic diagram of the touch panel which laminated | stacked the conventional two conductive sheets. It is another schematic diagram of the touch panel which laminated | stacked the conventional two conductive sheets.

  Hereinafter, referring to FIGS. 1 to 16, 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 the front surface and the lower surface is the back surface.

A first aspect of the transparent conductive sheet of the present invention is a double-sided conductive pattern type transparent conductive sheet in which conductive layers made of conductive thin wires are formed on both sides of a transparent support, and at least of the conductive layers on both sides. The double-sided conductive pattern type transparent conductive sheet is characterized in that the conductive layer on one side has a portion where the metal density of the conductive thin wire is high and a portion where the metal density is low.
Here, the high metal density means the metal density when the formed conductive pattern is cut from the conductive pattern surface toward the transparent support with a constant thickness. The component other than the metal that causes the density difference may be any material that does not exhibit conductivity, such as a gas such as air, various binders, or a metal salt not reduced to metal.

As the metal constituting the conductive thin wire of the conductive layer of the present invention, it is preferable to use a highly conductive metal or alloy. Examples of such metals include copper, silver, gold, platinum, palladium, nickel, tin, aluminum, cobalt, rhodium, iridium, iron, ruthenium, osmium, manganese, molybdenum, tungsten, niobium, tantel, titanium, and bismuth. , Antimony, lead and the like. Among these, copper, silver, gold, platinum, palladium, nickel, tin, aluminum, and alloys thereof are preferable in terms of excellent conductivity.
For forming a conductive pattern with these metals or alloys, a method of forming a metal foil or a metal thin film and then forming a conductive pattern using photolithography, a conductive ink (or paste) containing conductive nanoparticles In the present invention, the method using the latter conductive ink or paste or the method using developed silver described later is preferable.

In addition to the above metal fine particles, carbon may be used as the conductive nanoparticles. The conductive nanoparticles are preferably particles containing gold, silver, palladium, platinum, copper, carbon, or a mixture thereof. The average particle size of the nanoparticles is 2 μm or less, preferably 200 to 500 nm, and those having a particle size smaller than that of conventional micron particles are preferable for forming a mesh pattern. Screen printing or gravure printing is used for mesh pattern printing.
The conductive material included in the ink (or paste) may be conductive fibers instead of metal particles. In the present case, the conductive fiber includes a metal wire, a fibrous substance called nanowire, a hollow structure tube, and a nanotube. The average minor axis length of the metal nanowire (sometimes referred to as “average minor axis diameter” or “average diameter”) is preferably 100 nm or less, more preferably 1 nm to 50 nm, still more preferably 10 nm to 40 nm, and even more preferably 15 nm. -35 nm is particularly preferred. In the case of forming a conductive layer using conductive fibers, for example, JP2009-215594, JP2009-242880, JP2009-299162, JP2010-84173, JP2010-87105, JP2010. It can be formed by combining the techniques disclosed in -86714.

  2 to 4 show a double-sided conductive pattern type transparent conductive sheet. In the conductive thin wires 21 and 22 of the conductive patterns of FIGS. 2 and 3, there are portions where the density of the metal is different. Some parts are shown by dotted lines. 2 shows that there is a density difference only in the lower conductive pattern fine wire 22, and FIG. 3 shows that there is a density difference in both the upper conductive pattern fine wire 21 and the lower conductive pattern fine wire 22. The density difference may be different at the boundary of the dotted line portion as shown by the dotted line in FIGS. 2 and 3, and the present invention includes a case where the density continuously changes.

  Furthermore, in the second embodiment of the double-sided conductive pattern type transparent conductive sheet of the present invention, pattern exposure and development processing are performed on a photosensitive material having a photosensitive layer containing a silver halide emulsion on both sides of a transparent support. Is a double-sided conductive pattern type transparent conductive sheet in which conductive layers made of developed silver conductive wires are formed on both sides of a transparent support, and the conductive layer on at least one side of the conductive layers on both sides constitutes a conductive thin wire It is a double-sided conductive pattern type transparent conductive sheet characterized by having a portion having a high developed silver density and a portion having a low developed silver density. The first embodiment uses metal in general as the conductive pattern material, whereas the second embodiment is characterized in that developed silver is used. The “conductive layer on at least one surface of the conductive layers on both sides of the above aspect has a portion with a high developed silver density and a portion with a low developed silver density” constituting the conductive thin wire is the lower conductive pattern of FIG. This corresponds to 22.

Further, in the above-mentioned double-sided conductive pattern type transparent conductive sheet of the present invention, the silver density on the side close to the transparent support of the developed silver fine wire formed on one side of both sides of the transparent support is the silver density of the silver in the fine wire. A double-sided conductive pattern type transparent conductive sheet characterized in that the silver density on the side farther from the transparent support of the developed silver fine wire formed on the other surface is lower than the average density and lower than the average density of silver in the fine wire. .
In the above, the conductive pattern corresponding to “the silver density on the side of the developed silver fine wire formed on one side of the both sides of the transparent support close to the transparent support is lower than the average density of silver in the fine wire” is shown in FIG. 3, and the conductive pattern corresponding to “the silver density far from the transparent support of the developed silver fine wire formed on the other surface is lower than the average density of silver in the fine wire” is shown in FIG. This is the upper conductive pattern 21.

Below, the photosensitive material for forming the 2nd aspect of the double-sided conductive pattern type transparent conductive sheet of this invention, and the preparation method of the double-sided conductive pattern type transparent conductive sheet using this photosensitive material are explained in full detail.
The light-sensitive material of the present invention is a light-sensitive material in which a light-sensitive layer containing a silver halide emulsion is formed on both surfaces of a transparent support, and the light-sensitive material formed on either the front surface or the back surface. The layer is a photosensitive material having a photosensitive layer having a small volume ratio of silver and binder (that is, a ratio obtained by dividing the volume of silver by the volume of binder) and a photosensitive layer having a large volume ratio of silver and binder.
Another photosensitive material of the present invention is a photosensitive material in which a photosensitive layer containing a silver halide emulsion is formed on both sides of a transparent support, and silver is formed on one side of the transparent support from the side closer to the support. And a photosensitive layer having a small volume ratio of binder and a photosensitive layer having a large volume ratio of silver and binder in this order, and the volume ratio of silver to binder from the side closer to the support surface on the other surface of the transparent support. Is a photosensitive material having at least a photosensitive layer having a large volume and a photosensitive layer having a small volume ratio of silver and binder in this order.

The structure of the photosensitive material will be described with reference to FIGS. The photosensitive material 05 for producing the transparent conductive sheet of the present invention has an upper photosensitive material layer (front surface photosensitive material layer) 50 and a lower photosensitive material layer (back surface photosensitive material layer) on both surfaces of the transparent support 32. 60 is formed. The upper photosensitive material layer and the lower photosensitive material layer have protective layers 55 and 65, photosensitive layers 51 and 61, antihalation layers 57 and 67, and easy adhesion layers 56 and 66, respectively. This configuration is common to FIGS. 9 and 10 of the present invention and FIG. 11 which is a conventional configuration example. In FIG. 11 of the conventional example, the silver density (volume ratio of silver and binder) of both the upper photosensitive layer 51 and the lower photosensitive layer 61 is substantially constant in the layer, whereas in FIG. In the layer 61, the photosensitive layer 69 close to the support has a low silver density (volume ratio of silver and binder), and the photosensitive layer 68 far from the support has a high silver density. In the upper photosensitive layer 51, the silver density (volume ratio of silver and binder) of the photosensitive layer 58 close to the support is high, and the silver density of the photosensitive layer 59 far from the support is low. 9 and 10 of the present invention, the structure of the upper photosensitive layer and the lower photosensitive layer is asymmetric with respect to the transparent support.
In the present invention, the silver density, that is, the volume ratio of silver and binder is calculated or measured only in each photosensitive layer, and does not contain a silver halide emulsion such as a protective layer, an antihalation layer, and an easy-adhesion layer. The component of is not included. Further, the volume of silver is obtained by calculating or actually measuring the amount of silver applied and converted into a volume having a specific gravity of 10.5, and the volume of the binder is obtained by actually measuring whether the solid content other than silver is calculated. 34 is converted into a volume. When the ratio of the latex polymer contained in the gelatin exceeds 20% by mass, the volume of the latex polymer is calculated using the specific gravity of the latex polymer.

  In the photosensitive material of the present invention, the volume ratio of silver to binder in the photosensitive layer having a small volume ratio of silver to binder is 0.05 to 0.5, and the silver to binder in the photosensitive layer having a large volume ratio of silver to binder The volume ratio is preferably 0.7 or more, and the volume ratio of silver and binder in the photosensitive layer having a small volume ratio of silver and binder is 0.1 or more and 0.4 or less, and the volume ratio of silver and binder is It is more preferable that the volume ratio of silver and binder in the photosensitive layer having a large is 1.0 or more.

In the present invention, the thickness of the photosensitive layer is described by the amount of silver applied. The thickness itself can be obtained by the above conversion method based on the amount of silver applied and the amount of additives such as a binder. Specifically, the silver coating amount of each of the upper photosensitive layer 51 and the lower photosensitive layer 61 is preferably 4 g / m ² or more and 230 g / m ² or less, and more preferably 5 g / m ² or more and 20 g / m ² or less. When it is 4 g / m ² or more and 230 g / m ² or less, it is possible to form a coating film and a conductive sheet having low resistance and stable production. The coated silver amount of the upper photosensitive layer 51 and the lower photosensitive layer 61 may be the same coating amount or different coating amounts as long as they are within the above range.
The film thickness of the photosensitive layers 59 and 69 having a small volume ratio of silver and binder is preferably 10% or more and 40% or less, and preferably 15% or more and 30% or less with respect to the total film thickness of the upper photosensitive layer 51 and the lower photosensitive layer 61, respectively. Is more preferable.
The materials constituting the photosensitive material of the present invention are described in detail below.

(Transparent support)
As the transparent support 32 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 more preferably 50 μm or more and 250 μm or less from the viewpoint of production.
When the transparent conductive sheet formed using the photosensitive material of the present invention is used for a touch panel, the transparent material 30 to be a touch surface can be a plastic film used as the above-mentioned support for photosensitive material, For example, films made of polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN); polyolefins such as polyethylene (PE), polypropylene (PP), and polystyrene are preferable.
Moreover, the same film as the transparent material 30 can also be used as the material that can be used for the transparent support 33 at the bottom of the touch panel.

[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 a conductive pattern material, the type of photosensitive material and the type of development processing should be selected from the following three methods. Can do.
(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.
The light-sensitive material of the present invention preferably contains a silver chlorobromide emulsion, and the silver bromide content of the silver chlorobromide emulsion of the photosensitive layer having a small volume ratio of silver to binder is the volume ratio of silver to binder. More preferably, the silver bromide content of the silver chlorobromide emulsion of the photosensitive layer having a large is higher by 5 mol% or more.
Further, the silver bromide content of the silver halide emulsion in the photosensitive layer having a small volume ratio of silver and binder is 40 mol% or more, and the silver bromide of the silver halide emulsion in the photosensitive layer having a large volume ratio of silver and binder. The content is less than 40 mol%, and it is particularly preferable that the silver bromide content difference is 5 mol% or more. By designing in this way, the difference in color can be reduced.

  In the present invention, it is preferable to include a small amount of silver iodide in order to suppress fogging, and the silver iodide content is in a range not exceeding 1.5 mol% per mol of silver halide emulsion. It is preferable. 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. In the present invention, 0.5 mol% of silver iodide is included, but in order to avoid complicated description, the display of silver iodide is omitted.

  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.

(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. .
(Development inhibitor)

In the present invention, a development inhibitor such as sodium bromide or potassium bromide is included in the development processing solution described later to control the development speed so that developed silver is obtained only in the exposed area. However, in a system having a large amount of silver as in the present invention, it is expected that a development inhibitory substance is consumed as the developer permeates from the surface of the photosensitive layer, causing a phenomenon in which physical development proceeds. Therefore, it is preferable to include a development inhibitor on the lower layer side of the photosensitive layer.
Development inhibitors used in the photosensitive layer include organic mercapto compounds, unsaturated 5-membered heterocycles or 6-membered heterocycles having nitrogen atoms such as pyrrole ring, imidazole ring, pyrazole ring, pyrimidine ring, pyridazine ring, pyrazine ring, etc. A ring can be mentioned. In order for these compounds to remain in a specific layer and be activated by a permeated developer, a) a relatively low molecular weight compound that remains in a specific layer due to the interaction with the emulsion. A compound that is activated by alkali in the solution, b) a compound that has a large molecular weight and is difficult to move, but reacts with the alkali to release a low-molecular inhibitory compound, and c) a molecular weight that is difficult to move but is an oxidation product in the treatment liquid. Examples include compounds that react to release low-molecular inhibitory compounds.

  Examples of a) include mercapto compounds having a 5-membered ring azole having an NH structure or a 6-membered ring azine having an NH structure as a skeleton. As the mercapto compound, compounds described in paragraph 34 to paragraph 102 of JP-A No. 2007-116137 can be used, preferably 39 compounds described in paragraph 60 to paragraph 65, and paragraphs 90 to 93. And the three compounds described in paragraph 101. Among these compounds, compounds that can be particularly preferably used are the compounds described in paragraphs 60, 65, and 101.

As an example of the above b), a compound group described in JP-A-2-285344, which has an adsorption ability for silver halide grains but is protected so as not to exhibit the adsorption ability before development, that is, development. Mention may be made of compounds known as inhibitor precursors. As these compounds, compounds represented by (1) to (33) of JP-A-2-285344 can be used.
Examples of the above c) include redox compounds described in Japanese Patent No. 4035268, which can release a low-molecular development inhibitor when oxidized. As these compounds, compounds represented by the general formulas (1) to (3) described in Japanese Patent No. 4035268 are preferable, hydrazine derivatives are more preferable, and specifically R-1 to R-70 hydrazines. Derivatives are particularly preferred.

  The development inhibiting compound of the present invention contained in the photosensitive layer may be uniformly contained in the photosensitive layer, but the photosensitive layer (u layer) in which the content of the development inhibiting compound in the photosensitive layer is close to the transparent support. ) Is preferably high. Furthermore, it is more preferable to include the mercapto compound only in the photosensitive layer on the transparent support side, in other words, to localize the development inhibitor in the layer farthest from the photosensitive layer surface in contact with the developer. Alternatively, it is preferable to sequentially increase the concentration of the development inhibitor toward the layer far from the photosensitive layer surface in contact with the developer.

The amount of the development inhibiting compound contained in at least one of the plurality of photosensitive layers of the present invention is the amount of addition itself in the case of a), and the amount of the released inhibitor in the cases of b) and c), It is preferably 0.1 mg or more and 15 mg or less, more preferably 0.5 mg or more and 10 mg or less with respect to 1 g (gram) of silver in the silver halide emulsion contained in the same layer as the development inhibiting compound. It is particularly 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.
[Other layers]

In the photosensitive material having photosensitive layers on both sides of the transparent support of the present invention, antihalation layers 57 and 67 are preferably provided between the transparent support and the respective photosensitive layers.
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 light to be exposed, but is preferably about 0.5 to 3.0.

  It is preferable to provide protective layers 55 and 65 on the photosensitive layer of the present invention. The “protective layer in the form” of this embodiment expresses the effect of preventing emulsion fogging and conductive pattern damage due to scratches and improving mechanical properties of conductive patterns formed by subsequent photosensitive materials and development processing. Therefore, it is formed on a photosensitive layer having photosensitivity. For the protective layer, in order to improve fine particles and slip for increasing the strength of the film to the binder such as gelatin or polymer polymer described in the (Binder) section described in the above [Photosensitive layer containing silver halide emulsion]. And a matting agent for controlling the surface roughness of the light-sensitive material to prevent adhesion when it is formed into a roll shape. The thickness of the protective layer 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. It is preferable that the matting agent does not hinder the transparency even if it remains after the development processing or dissolves in the processing step.

Next, a process for producing the transparent conductive sheet of the present invention using the photosensitive material of the present invention described above will be described with reference to FIG.
12A shows the transparent support 32, and FIG. 12B shows the photosensitive material 05 of the present invention in which the upper photosensitive material layer 50 and the lower photosensitive material layer 60 are provided on both surfaces of the transparent support by coating. (C) represents a view of the photosensitive material of the present invention exposed through a photomask, and (d) represents a developed silver conductive pattern formed by a development fixing process subsequent to the exposure. Below, each process after exposure is demonstrated.
[exposure]

  Since the photosensitive material 05 of the present invention is a photosensitive material having a photosensitive layer formed on both sides of a support, in the present invention, exposure for forming a conductive pattern is performed from both sides of the photosensitive material of the present invention. It is preferable. Specifically, as shown in FIG. 12C, light is irradiated on both sides of the photosensitive material 102a and 102b for 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 conductive patterns of FIGS. 7 and 8 to be described later with developed silver, the photomasks 110 and 120 are the upper conductive pattern 11 and the lower conductive pattern 12 of FIG. The portion corresponding to the conductive thin wire of the conductive pattern 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. In the portions 131 and 141 where the latent image is formed, a developed silver pattern is formed by development processing in the next step. 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 for absorbing the light transmitted through the photosensitive layer 51 already described. 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. 13 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. 13, the positioning of the two exposure apparatuses is strictly performed. The silver image formed by the photomasks 110 and 120 having the patterns shown in FIGS. 6 and 7 is strictly positioned so as to form a uniform pattern as shown in FIG.
14 to 16 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 surface exposure as shown in FIG. 13 or may be 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 to thereby develop a front surface conductive pattern composed of developed thin conductive silver wires and development. The back surface conductive layer pattern which consists of a conductive fine wire of silver can be formed on both surfaces of a transparent support body.
In addition, the conductive sheet formed as described above is exposed so that the conduction direction of the front surface conductive pattern and the conduction direction of the back surface conductive pattern are orthogonal to each other, and then developed. It is formed.
That is, in the pattern exposure according to the present invention, the conduction direction of the conductive pattern on one side of the conductive layer formed on both sides of the support after the development processing is perpendicular to the conduction direction of the conductive pattern on the other side. It is characterized by being patterned.
Further, the pattern exposure of the present invention is adjusted so that a conductive pattern composed of conductive thin wires of developed silver formed on both sides of the support after development processing can be regarded as a continuous pattern when seen through from one side. It is characterized by that.

(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 setting the gradation to 4.0 or higher include doping of the aforementioned rhodium ions and iridium ions, and containing 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.
Moreover, the volume low efficiency of the obtained transparent conductive sheet is preferably 160 μΩcm or less, more preferably in the range of 1.6 to 16 μΩcm, and in the range of 1.6 to 10 μΩcm. It is more preferable.

(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 surface pressure of 699.4 kgf / cm ² or more, more preferably 2940 N / cm (300 kgf / cm, converted to surface pressure, 935.8 kgf / cm). ² ) or more. 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 process may be performed either before or after the plating process. However, when the smoothing process is performed before the plating process, the plating process becomes 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 double-sided conductive sheet 10 made of conductive thin wires formed through the above process is a patterned conductive pattern made of a plurality of conductive thin wires.
The double-sided conductive pattern type transparent conductive sheet of the present invention is also used for antistatic purposes, but is preferably used as a heating element, electromagnetic wave shield, or electrode material. More preferably, it is used for a capacitive touch panel.
Hereinafter, the conductive sheet having conductive thin wires formed and patterned 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 a conventional capacitive touch panel, an ITO thin film is processed into a bar electrode as a conductive material. 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. Therefore, this is called a conductive pattern.

As shown in FIG. 1, the capacitive touch panel using the transparent conductive sheet of the present invention has a glass plate 34 provided as needed from the lower part of the figure on the side to be installed in an image display device, etc. The support 33, the double-sided conductive sheet 10, and the transparent support 30 that also serves as a touch surface are stacked, and an opaque frame member having an open touch surface is stacked thereon. The portion indicated by 02 in FIG. 1 is the touch surface. Adhesives 41 and 42 that also serve as insulating layers are filled between the double-sided conductive sheet 10 and the transparent supports 30 and 33 on both sides thereof.
An upper conductive pattern (also referred to as a front surface conductive pattern) 11 of the double-sided conductive sheet 10 has a pattern as shown in the upper diagram of FIG. 5, and each conductive pattern has a plurality of conductive characteristics that sense capacitance. It comprises a child portion 14A, a conductive connecting portion 16A that connects the lattice and the lead wire 18A that connects the conductive pattern and the external control portion. FIG. 6 is an enlarged view of the conductive grid portion 14A and the connecting portion 16A. In FIG. 6, 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 arranged around the square lattice composed of the conductive thin wires 21, the dummy thin wires 19 including a plurality of short wires, and the conductive wire connecting the conductive lattice portion 14A in the direction of the conductive pattern. The connecting portion 16A is described. In order to prevent the conductive pattern 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 conductive pattern (also referred to as the back surface conductive pattern) 12 has a pattern as shown in the lower diagram of FIG. 5. Each conductive pattern includes a plurality of conductive grid portions 14B for sensing capacitance, a grid and a grid. The conductive connecting portion 16B is connected, and the lead wire 18B is connected to the conductive pattern and the external control portion. The description of FIG. 7 can be based on the description of the upper conductive pattern 11.
The patterned conductive pattern is preferably a conductive sheet having a square lattice or a rectangular lattice in the conductive pattern by conductive thin wires.

FIG. 8 shows how the conductive pattern looks when FIG. 5 is seen through from the toucher side. FIG. 8 using the upper conductive sheet 11 and the lower conductive sheet 12 of the present invention has a uniform square lattice, and can constitute a panel that is easy to visually recognize. In FIG. 8, 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 circled portion in FIG. 8, and the solid line portion on the left side represents a part of the conductive thin wire 21 of the conductive lattice portion 14 </ b> A 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 visibility, and as described in FIGS. 6 and 7, 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. The length of the dummy fine wire is preferably ½ or less of the side length of the unit cell of the conductive pattern portion.
6 to 8, the double-sided conductive sheet is cut at this position, and the sectional view at this position is the touch panel of FIG. 1 and the double-sided conductive sheet of FIGS. 2 to 4. Show.

Below, the upper conductive sheet 11 is taken as an example, and the details of the conductive pattern will be described. The ITO diamond pattern that has been used to form a conventional conductive pattern is difficult to apply to a large screen 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, 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 conductive pattern 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 conductive pattern having a low resistance and an excellent 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.

In addition, although the conduction | electrical_connection direction of the up-and-down conductive pattern of the touch panel of FIG. 5 is made substantially orthogonal, it can set to arbitrary angles, as long as there is no trouble in the coordinate determination of a touch position.
Furthermore, the direction of the conductive thin wires constituting the square lattice illustrated in FIGS. 6 and 7 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 attached as the directions of the conductive pattern axes of the image display device.

The conductive sheet composed of the above-described patterned conductive patterns can significantly reduce the electric resistance as compared with the configuration in which one conductive pattern 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"

The conductive sheet of the present invention has an upper conductive pattern and a lower conductive pattern formed on both sides of a single transparent support used to improve productivity, as described in the means for solving the problems. It is an electroconductive sheet which can make a tint difference small.
The improvement of the color difference is far from the transparent support of the surface conductive pattern of the conductive sheet (also referred to as a double-sided conductive sheet) having an upper conductive pattern and a lower conductive pattern formed on both sides of a single transparent support. The absolute value of the difference between the reflection chromaticity b ₁ ^* of the conductive pattern surface on the side and the reflection chromaticity b ₂ ^* of the conductive pattern surface on the side close to the transparent support of the back surface conductive pattern is 2 or less (| Δb ^* | = | B ₁ ^* −b ₂ ^* | ≦ 2). More specifically, the reflection chromaticity b ^* value of the conductive pattern measured from the toucher side is used as the reflection chromaticity b ₁ ^* of the conductive pattern (front surface conductive pattern) on the side closer to the toucher of the double-sided conductive pattern ^. And the absolute value of the difference between the reflected chromaticity b ₁ ^* and the reflected chromaticity b ₂ ^* is 2 or less, assuming that the reflected chromaticity b ₂ ^* of the conductive pattern (back surface conductive pattern) on the side far from the toucher is This can be achieved by a touch panel using a transparent conductive sheet (| Δb ^* | = | b ₁ ^* −b ₂ ^* | ≦ 2).
Here, the reflection chromaticity b ₁ ^{* of the} surface of the conductive pattern far from the transparent support of the surface conductive pattern is the reflection chromaticity of the surface of the conductive pattern in the region d1 in FIG. It is a b ^* value when measured from a certain viewer side. The reflective chromaticity b ₂ ^* of the conductive pattern surface on the side close to the transparent support of the back surface conductive pattern is the reflective chromaticity of the conductive pattern surface in the region d2 in FIG. B ^* value when measured from the side.

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 direction in which the conductive pattern is observed than the a ^* value. Specifically, the b ^* value is easily visually recognized as color unevenness by moving from yellow to blue or vice versa. Details of the measurement method are described in the Examples section.

The improvement of the color of the conductive pattern surface of the double-sided conductive sheet is 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 of the developed silver conductive pattern The color of the surface of the conductive pattern far from the body tends to be blue, and the color of the surface of the conductive pattern near the transparent support of the developed silver conductive pattern 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 means 1) to 30) of means for solving the problems.

  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. Therefore, 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, 0.10 g of potassium iodide was added and ripened for 5 minutes to complete the 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 salt
(20% aqueous solution containing 0.005% KCl) 5 ml
Ammonium hexachlororhodate (20% aqueous solution containing 0.001% NaCl) 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 0.05 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. The photosensitive layer coating solution was prepared as a reference prescription coating solution. The volume ratio of silver and binder in the coating solution at this time is 2.0.
When the volume ratio of silver and binder is smaller than 2.0 of the standard formula, adjust the volume ratio of silver and binder by adding gelatin to the coating solution, and change the ratio of silver chloride and silver bromide above. The coating solutions for the front surface and the back surface of Table 2 were prepared and prepared by changing the ratio of sodium chloride and potassium bromide in the third and fifth solutions.
Since the photosensitive layer in Table 2 may have three layers, all examples are represented by a three-layer configuration for convenience, and are represented as a u layer, an m layer, and an o layer from the side close to the support. In the case of Comparative Example 1, both the front surface and the back surface are examples of a single coating layer configuration. Also, the indication in parentheses in the silver density row of each layer represents the ratio of the film thickness. For example, the back surface of Example 1 indicates that the thickness of the o layer and the u layer is 0.8: 0.2. Show. The development inhibitor was a compound of the structural formula attached mainly to the u layer in the table.

After corona discharge treatment is applied to both sides of a 100 μm polyethylene terephthalate (PET) film, a 0.1 μm thick gelatin subbing layer (adhesive layers 56 and 66), and an optical density of about 1.0 on the subbing layer. Anti-halation layers 57 and 67 containing a dye that is decolorized by alkali of the developer are provided on both surfaces to form a transparent support 32 for a conductive sheet.
The photosensitive layer coating solution prepared and prepared above was applied to both surfaces of this support. The silver coating amount of the entire photosensitive layer is an amount converted from the silver image thickness in Table 2, and the film thickness and silver amount of each of the three photosensitive layers (u layer, m layer, o layer) Can be calculated from the film thickness ratio, the silver density of each layer, and the silver amount of the entire photosensitive layer.
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 development inhibitory compound used for each photosensitive layer was displayed as mg of the development inhibitory compound added to 1 g of silver. The structure of the development inhibiting compound used is shown after Table 2.
Further, a protective layer having a thickness of 0.15 μm made of gelatin containing a preservative was provided on the o layer. Three layers of the photosensitive layer and four layers of the protective layer were coated using a simultaneous coater to prepare photosensitive materials 1 to 29.

(Exposure and development processing)
Next, the photosensitive materials 1 to 29 prepared above were subjected to double-sided exposure using the double-sided exposure machine shown in FIG. A high-pressure mercury lamp is used as the light source, the mask for forming the pattern in FIG. 6 (upper conductive pattern 11 in FIG. 5) is used as the photomask on the front side, and the photomask on the back side is shown in FIG. 5 was exposed using a mask for pattern formation of the lower conductive pattern 12). The light transmission windows of the mask used are the negative patterns shown in FIGS. 6 and 7, 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, development is performed using a fixer (trade name: N3X-R for CN16X: manufactured by Fuji Photo Film Co., Ltd.), rinse with pure water, and drying. A double-sided conductive pattern type transparent conductive sheet 1 was obtained. Similarly, double-sided conductive pattern type transparent conductive sheets 2 to 29 were obtained.

(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 300 μm-thick polyethylene terephthalate film was adhered to the front surface side of the above-described double-sided conductive pattern type transparent conductive sheet 1 using an adhesive. Further, a glass plate having a thickness of 3 mm was bonded to the back surface side of the transparent conductive sheet 1 with an adhesive to produce a capacitance type touch panel of Comparative Example 1. The capacitive touch panels of Comparative Examples 2 and 3 and the capacitive touch panels of Examples 1 to 26 are the same as Comparative Example 1 except that the transparent conductive sheets 2 to 29 are used instead of the transparent conductive sheet 1. It was created.

(Evaluation)
The following evaluation was performed using the double-sided conductive pattern type transparent conductive sheets 1 to 29 created above.
(1) Reflection chromaticity b ₁ ^* and b ₂ ^* measurement measurement samples are 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 solid mask with 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. the reflection chromaticity was measured reflection chromaticity b ₂ ^* and then, the obtained reflection chromaticity b ₁ ^*, from the reflection chromaticity b ₂ ^*, and calculates the absolute value of the difference △ b ^*.

(2) Evaluation of visibility Observe the created transparent conductive sheet of the double-sided conductive pattern type from the vertical direction and the oblique direction of each direction, and sensory evaluation such as uneven color of reflected light, fluctuation of reflected light, contour of conductive pattern, etc. Was performed as follows.
Evaluation ◎ Not concerned at all.
Evaluation ○ I don't care.
△ Depending on the direction, there are times when you are concerned.
Evaluation × I am interested.

(3) Conductivity Evaluation The resistance value of the conductive pattern of the transparent conductive sheet was directly read and evaluated based on the resistance value of the conductive pattern on the front surface and the conductive pattern 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 / □.
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 below.

From the results of Table 2 above, the following was found.
Comparative Examples 1 to 3 in which the density of silver in the conductive layer (volume ratio of silver and binder) is uniform satisfy both the color (reflection chromaticity, color unevenness, and visibility of color) and conductivity. It hasn't been done yet.
In comparison with Comparative Examples 1 to 3, Examples 1 to 3 in which the back surface conductive pattern has a high silver layer having a silver density of 1.0 or 1.5 and a low silver layer of 0.3 are colored. Has been greatly improved. Although the improvement effect of Example 2 is slightly small, Example 1 has the best visibility.
Examples 4 to 8 are examples in which the front surface conductive pattern and the back surface conductive pattern were further divided into multiple layers. The silver density 0.3 of the u layer of the back surface conductive pattern was further increased to 0.375 and 0. Example 6 divided into .2 layers has the same improvement effect as Example 1. It was found that providing a low-density layer with a small amount of silver is effective for achieving both color and conductivity. The other embodiments have the same performance as that of the third embodiment.
Examples 9 to 17 are examples in which the silver bromide ratio was changed in addition to the multilayering due to the difference in silver density. Increasing the silver bromide ratio has the effect of shifting the color tone of the developed silver surface toward the bluish direction. By combining these, Examples 9 to 16 can achieve the same performance as Example 2 or 3. In addition, the performance of Example 17 is close to that of Example 1.
Examples 18 to 26 are examples in which a development inhibitor was further added to the u layer on one side (back side conductive pattern in the examples). When a development inhibitor was used, it was found that the performance equivalent to or higher than that of Example 1 can be achieved as in Examples 20 to 22, and it is effective as a means for adjusting the color. Although the effect is large in the order of Compound 12, Compound R-1, and Compound F used in Examples, each can be used properly according to the color to be adjusted.

01 Touch panel 02 Touch surface 03 Touch surface cover 05 Photosensitive material 10 for producing a transparent conductive sheet Transparent conductive sheet (also referred to as a double-sided conductive sheet)
11 Upper conductive pattern (front surface conductive pattern, also called front surface electrode)
12 Lower conductive pattern (also called back side conductive pattern, back side electrode)
14A, 14B A plurality of conductive grating portions 16A, 16B for sensing electrostatic capacitance. Conductive connecting portions 18A, 18B for connecting the lattice to the lattice. Lead wires 19 for connecting the conductive pattern and the external control portion 19. Dummy thin wire 21 Upper conductive pattern (upper portion) Conductive thin wire 22 constituting a lower conductive pattern (also referred to as a lower electrode) 30 Conductive fine wire constituting a lower conductive pattern 30 Transparent support 31 for a touch surface Transparent support 32 for a conductive sheet also serving as a touch surface Transparent support 33 Transparent support 34 Glass plates 41 and 42 Adhesive layer 50 also serving as an insulating layer Upper photosensitive material layer (front 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 58 High-density silver layer 59 in the upper photosensitive layer 59 Low-density silver layer 60 in the upper photosensitive layer 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 layer 68 High-density silver layer 69 in the lower photosensitive layer Low-density silver layers 100a and 100b in the lower photosensitive layer 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 used for forming upper conductive pattern (front surface conductive pattern) 120 Photomasks 111 and 121 used for forming lower conductive pattern (back surface conductive pattern) Light transmitting portions 112 and 122 of photomask Light-shielding portions 131, 141 exposed portions in the photosensitive layer (portions where latent images are formed)
132, 142 Parts of the photosensitive layer that were not exposed (parts where no latent image was formed)
151 (21) Silver thin wire of the upper conductive pattern formed after development processing (conductive thin wire constituting the upper conductive pattern)
161 (22) Silver thin wire of lower conductive pattern formed after development processing (conductive thin wire constituting lower conductive pattern)
152, 162 Transparent layer d1 from which unexposed silver halide emulsion and the like have been removed by development processing Region where conductive fine lines of upper conductive pattern are continuously arranged (place visible as b ₁ ^* )
d2 Region where conductive thin wires of the lower conductive pattern are continuously arranged (place visually recognized as b ₂ ^* )

Claims (15)

  A transparent conductive sheet in which conductive layers made of conductive thin wires are formed on both sides of a transparent support, wherein at least one of the conductive layers on both sides has a high density of metal constituting the conductive thin wires and a low density A transparent conductive sheet comprising a portion.   The transparent conductive sheet is formed by subjecting a photosensitive material in which a photosensitive layer containing a silver halide emulsion is formed on both sides of a transparent support to pattern exposure and development, thereby forming a conductive layer composed of conductive fine wires on the transparent support. A transparent conductive sheet formed on both sides, wherein at least one of the conductive layers on both sides has a high density part and a low density part of the metal constituting the conductive thin wire. The transparent conductive sheet according to 1.   The transparent conductive sheet according to claim 2, wherein the silver density on the side close to the transparent support of the developed silver fine wire formed on one side of both sides of the transparent support is lower than the average density of silver in the fine wire, And the silver density of the side far from the transparent support body of the development silver fine wire formed in the other side is lower than the average density of the silver in a thin wire, The transparent conductive sheet characterized by the above-mentioned.   The photosensitive material is a photosensitive material in which a photosensitive layer containing a silver halide emulsion is formed on both sides of a transparent support, and the photosensitive layer formed on either the front side or the back side. The photosensitive material according to claim 2, comprising a photosensitive layer having a small volume ratio of silver and binder and a photosensitive layer having a large volume ratio of silver and binder.   The volume ratio of silver and binder of the photosensitive layer having a small volume ratio of silver and binder is 0.05 or more and 0.5 or less, and the volume ratio of silver and binder of the photosensitive layer having a large volume ratio of silver and binder is 0. The photosensitive material according to claim 4, wherein the photosensitive material is 7 or more.   The photosensitive material includes a silver chlorobromide emulsion, and the silver bromide content of the silver chlorobromide emulsion of the photosensitive layer having a small volume ratio of silver and binder is the salt of the photosensitive layer having a large volume ratio of silver and binder. 6. The light-sensitive material according to claim 2, which is higher by 5 mol% or more than the silver bromide content of the silver bromide emulsion.   The silver bromide content of the silver halide emulsion of the photosensitive layer having a small volume ratio of silver and binder is 40 mol% or more, and the silver bromide content of the silver halide emulsion of the photosensitive layer having a large volume ratio of silver and binder The photosensitive material according to claim 2, wherein the rate is less than 40 mol%.   8. The photosensitive layer having a small volume ratio of silver and binder contains a development inhibitor, and the other of the photosensitive layer having a small volume ratio of silver and binder contains no development inhibitor. 2. The photosensitive material according to any one of items 1.   9. The photosensitive material according to claim 8, wherein the development inhibitor is a mercapto compound.   The photosensitive material according to claim 2, wherein the photosensitive material on both sides of the transparent support has an antihalation layer between the transparent support and each photosensitive layer.   The said pattern exposure is given from both surfaces of the photosensitive material of Claims 2-10, The transparent conductive sheet characterized by the above-mentioned.   The pattern exposure is characterized in that the conductive direction of one surface of the conductive layer formed on both surfaces of the support after development processing is patterned so that the conductive direction of the other surface is orthogonal to each other. The transparent conductive sheet according to claim 11.   The pattern exposure is adjusted so that a conductive pattern made of conductive thin wires of developed silver formed on both sides of a support after development processing can be regarded as a continuous pattern when seen through from one side. The transparent conductive sheet according to claim 11 or 12.   A capacitive touch panel using the transparent conductive sheet according to claim 11. The capacitive touch panel using the transparent conductive sheet according to claim 14, wherein the reflection chromaticity b ^* value of the conductive pattern measured from the toucher side is defined as a conductive pattern (front surface) closer to the toucher. When the reflection chromaticity b ₁ ^* of the conductive pattern) and the reflection chromaticity b ₂ ^* of the conductive pattern (back surface conductive pattern) on the side far from the toucher are given, the reflection chromaticity b ₁ ^* and the reflection chromaticity b ₂ An absolute value of a difference from ^* is 2 or less (| Δb ^* | = | b ₁ ^* −b ₂ ^* | ≦ 2).

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