JP5463315B2 - Electrode sheet, electrode sheet manufacturing method, and touch panel - Google Patents

Description

  The present invention relates to an electrode sheet comprising a plurality of electrodes configured with a desired conductor pattern on a support and a plurality of wirings connected to each of the plurality of electrodes, a method for producing the electrode sheet, and an electrode sheet. It is related with the touch panel provided.

In recent years, in the field of touch panels (touch screens), there has been a growing demand for multi-touch and large screens. As for multi-touch, it is realized in a projection capacitive system having a plurality of electrodes arranged in the X direction and a plurality of electrodes arranged in the Y direction, and is capable of multi-touch. The touch panel has been widely used for PDAs, mobile phones and the like.
Here, when the panel has a large screen, it is essential to reduce the resistance of the electrode from the viewpoint of power consumption and response speed, and as a technique for reducing the resistance, a method of forming the electrode with a mesh-like conductor pattern Are described in Patent Documents 1 and 2, for example. The method for forming a conductive wire pattern described in these documents is a printing method using conductive ink or thinning of ITO or metal thin film by photolithography, but the former printing method has a stable line width. However, the latter has a problem of high cost because photolithography requires an expensive large-scale apparatus and is composed of a plurality of processes.
On the other hand, a method of forming a low-resistance lead pattern 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 (Patent Document 3). In this method, various patterns can be formed by exposure through a mask and subsequent development processing, so that the above-described problems in the printing method and photolithography can be solved.

JP 2010-039537 A International Publication No. 2010/014683 JP 2007-129205 A

  In order to manufacture a touch panel using the developed silver system, first, an electrode sheet is mass-produced by forming a conductive wire pattern, and the electrode is connected to an electrode according to the type of the touch panel, and the electrode is connected to an external device or the like. Wiring is provided. However, the manufactured electrode surface is likely to be scratched during winding, storage, unwinding, etc. at the time of manufacturing the electrode sheet, and the conductor pattern is liable to be peeled off or short-circuited. That is, the durability is difficult. Therefore, it is conceivable to insert a sandwich sheet between the sheets, or to provide a protective film on the emulsion layer of the silver halide photosensitive material. However, when using the sandwich sheet, the cost is high. Thus, when the protective film is provided, since the protective film is insulative, there is a possibility of causing a conduction failure between the electrode and the wiring. In addition, the material for forming the protective layer (resin) and the material for forming the wiring (metal / resin) are not compatible with the material itself or have different expansion coefficients for heat / humidity. There is also a problem that the wiring easily peels off after the durability test.

  An object of the present invention is an electrode sheet that does not cause a decrease in yield due to poor conduction or scratches, is excellent in wet heat durability, and can reduce the total resistance of electrodes and wiring, a method for manufacturing the electrode sheet, And it is providing a touch panel provided with an electrode sheet.

The present inventor has found out a technique for obtaining electrical continuity between the electrode and the wiring while using an insulating protective film through intensive research. More specifically, the thickness of the protective layer that can ensure scratch resistance at the time of manufacturing an electrode sheet and the like, and can reduce the total resistance between the electrode and the wiring without causing a failure in conduction, and the electrode And the ratio of wiring thickness.
That is, the present inventor has found that the above problem can be solved by the following means.

[1]
An electrode sheet having an electrode, a protective layer covering the electrode, and a wiring electrically connected to the electrode on at least one surface of the support,
The electrode is composed of a conductive thin wire containing developed silver,
The wiring is formed of conductive ink or conductive paste,
The protective layer has a thickness of 0.3 μm or less, and
An electrode sheet having a ratio of the thickness of the electrode to the wiring (thickness of the wiring) / (thickness of the electrode) of 3 or more.
[2]
The electrode sheet according to [1] above, wherein the conductive thin wire containing the developed silver is obtained by exposing and developing a photosensitive material having a silver halide emulsion layer.
[3]
The electrode sheet according to [1] or [2], wherein the protective layer has a thickness of 0.05 μm or more and 0.3 μm or less.
[4]
The electrode according to any one of [1] to [3], wherein the protective layer contains at least one of colloidal silica, silica mat, silicone oil, paraffinic oil, and (meth) acrylic particles. Sheet.
[5]
The electrode sheet according to any one of [1] to [4] above, wherein the protective layer contains colloidal silica.
[6]
Any one of the above [1] to [5], wherein the wiring is provided so as to cover at least a part of the electrode, and an area where the wiring covers the electrode is 1 × 10 ⁻⁸ m ² or more. The electrode sheet according to item.
[7]
The electrode sheet according to any one of [1] to [6], wherein a line width of the conductive thin wire is 20 μm or less.
[8]
The electrode sheet according to any one of [1] to [7], wherein the thickness of the electrode is 0.4 μm or more and 1.5 μm or less.
[9]
The electrode sheet according to any one of [1] to [8] above, wherein the protective layer has a scratch strength of 9 g or more.
[10]
The electrode sheet according to any one of [1] to [9], wherein the conductive ink or the conductive paste contains silver particles or a silver filler.
[11]
The electrode sheet according to any one of [1] to [10], wherein the electrode and the wiring are respectively formed on both surfaces of the support.
[12]
[1] to [1] to [1] to [1], wherein the support is formed with a conductive ink or conductive paste through holes for taking out the potential of the wiring provided on one surface of the support to the other surface of the support. The electrode sheet according to any one of 11].
[13]
On at least one surface of the support, there is an electrode composed of a pattern made of a conductive thin wire containing developed silver, a protective layer having a thickness of 0.3 μm or less covering the electrode, and a wiring electrically connected to the electrode. And the ratio of the thickness of the electrode and the wiring (thickness of wiring) / (thickness of electrode) is 3 or more,
An electrode forming step of forming an electrode composed of a conductive fine wire containing developed silver by exposing and developing a photosensitive material having a silver halide emulsion layer and a protective layer in this order on a support;
A method of manufacturing an electrode sheet, comprising: a wiring forming step of forming a wiring that is conducted to an electrode configured by a pattern made of the conductive thin wire using a conductive ink or a conductive paste.
[14]
The touch panel provided with the electrode sheet as described in any one of said [1]-[12], or the electrode sheet manufactured by the manufacturing method as described in said [13].

  According to the present invention, it is possible to provide an electrode sheet that can ensure scratch resistance, is excellent in wet heat durability without causing trouble in conduction, and can reduce the total resistance between the electrode and the wiring. Can do. In addition, since the resistance is reduced by the electrode sheet, a large-screen touch panel can be provided.

It is a sectional side view which shows the touch panel of this invention typically. It is side sectional drawing which shows the other touch panel of this invention typically. It is side sectional drawing which shows the other touch panel of this invention typically. It is side sectional drawing which shows the other touch panel of this invention typically. It is a top view which shows the surface in which the X electrode of the electrode sheet was formed. It is an enlarged view of a sensor part. It is a top view which shows the surface in which the Y electrode of the electrode sheet was formed. It is an enlarged view of a sensor part. It is the top view and side sectional view which show the connection part of a conductive fine wire and wiring. It is a sectional side view which shows the photosensitive material used for manufacture of an electrode sheet. It is a figure which shows the manufacturing process of an electrode sheet. It is a figure for demonstrating the exposure process of an electrode sheet. It is a top view which shows the surface in which the X electrode of the electrode sheet was formed.

Hereinafter, an example of the configuration and manufacturing method of a projected capacitive touch panel for explaining an embodiment of the present invention will be described with reference to FIGS.
In addition, about the structure similar to the structure already described, the same code | symbol is attached | subjected and description is abbreviate | omitted or simplified. Moreover, in this specification, "to" is used as the meaning including the numerical value described before and behind as a lower limit and an upper limit.

〔overall structure〕
1 to 4 schematically show sectional views of examples of the projected capacitive touch panel of the present invention.
The touch panel 1 of FIG. 1 includes an upper transparent cover member 11 that constitutes a touch surface 11A that is touched by a user, an electrode sheet 20 that is disposed on the back side in the visual recognition direction of the upper transparent cover member 11, and senses contact with a finger, The lower transparent cover member 12 arrange | positioned on the opposite side to the upper cover member 11 side of the electrode sheet 20 is provided. A dielectric layer 13 made of resin or the like is provided between the electrode sheet 20 and the upper transparent cover member 11, and a dielectric layer 13 is also provided between the electrode sheet 20 and the lower transparent cover member 12. ing.
The electrode sheet 20 includes a support 10, an electrode 30 formed on the support, and a protective layer that covers the electrode. The electrode is preferably constituted by a pattern made of conductive thin wires. In this specification, the electrode and the protective layer covering the electrode are collectively referred to as a “conductor pattern”.

  Electrodes and wirings formed in a conductive wire pattern are formed on both the front and back surfaces of the support 10 of the electrode sheet 20. That is, the X electrode 30 and the wiring 40 formed with the conductive pattern 70 are formed on the surface of the support 10, and the Y electrode 35 and the wiring 45 formed with the conductive pattern 70 are formed on the back of the support 10. Has been. The wiring 40 provided on the surface of the support 10 is drawn out to the back side of the support 10 through a through hole 48 provided in the support 10. The through hole 48 is formed by conductive ink filled in a hole formed in the support 10. The electrode sheet of the present invention preferably includes a plurality of electrodes and wirings from the viewpoint of various uses. The wiring is used to connect the electrode to an external device.

  The touch panel 2 of FIG. 2 includes a transparent cover member 11 that constitutes the touch surface 11 </ b> A and two electrode sheets 20 and 25. The upper electrode sheet 20 on which the X electrode 30 and the wiring 40 are formed and the lower electrode sheet 25 on which the Y electrode 35 and the wiring 45 are formed are overlapped with the surfaces on which the respective electrodes are formed facing the upper surface. It has been.

The touch panel 3 in FIG. 3 includes two electrode sheets 20 and 25 disposed in the opposite direction to the case in FIG. 2 and a transparent cover member 12 that covers the surface of the electrode sheet 25 on which the Y electrode 35 is formed. ing. The touch surface 11 </ b> A is configured by the upper electrode sheet 20.
In the touch panel 4 of FIG. 4, the upper electrode sheet 20 and the lower electrode sheet 25 that constitute the touch surface 11 </ b> A are overlaid with the surfaces on which the respective electrodes are formed facing inside.
Note that the touch panels 1 to 4 may be formed integrally with a display (not shown). Although not shown in FIGS. 1 to 4, a shield layer that shields electromagnetic waves from the display may be provided on the surface of the touch panel 1 to 4 facing the display.

  Regarding the touch panels 1 to 4, the transparent cover members 11 and 12, the support 10, and the shield layer may use the same insulating material, or may use different insulating materials, A plastic film, a plastic plate, a glass plate, etc. are used and formed. The thicknesses of these members, plates, and layers are appropriately determined according to the respective uses.

  Examples of the material of the plastic film and the plastic plate include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN); polyolefins such as polyethylene (PE), polypropylene (PP), polystyrene, and EVA; Resin; In addition, polycarbonate (PC), polyamide, polyimide, acrylic resin, triacetyl cellulose (TAC) and the like are used.

  Preferred materials for the plastic film and plastic plate include PET (melting point: 258 ° C.), PEN (melting point: 269 ° C.), PE (melting point: 135 ° C.), PP (melting point: 163 ° C.), polystyrene (melting point: 230 ° C.). ), Polyvinyl chloride (melting point: 180 ° C.), polyvinylidene chloride (melting point: 212 ° C.), TAC (melting point: 290 ° C.), etc. From the viewpoints of light transmittance and processability, PET is preferred. The thickness of the film or plate is preferably 50 μm to 300 μm.

  The entire dielectric layer 13 is formed as a non-conductive adhesive layer with an adhesive material, or includes a dielectric substrate and adhesive layers respectively provided on the front and back of the substrate. The A non-conductive adhesive or the like can be used for the pressure-sensitive adhesive layer included in the dielectric layer 13 and the pressure-sensitive adhesive layer used when the transparent cover members 11 and 12 are bonded to each other. Examples of the adhesive material include acrylic resin, epoxy resin, phenol resin, and vinyl resin. These adhesive layers are formed by, for example, a screen printing method.

[Configuration of electrode sheet]
FIG. 5 shows the surface of the electrode sheet 20 on which the X electrode 30 is formed. On the support 10, a plurality of X electrodes 30 formed of a conductive wire pattern 70 (FIG. 1) are arranged in the X direction.
Each X electrode 30 is formed by conducting a plurality of sensor portions 30 </ b> A formed in a rhombus (diamond shape) with a mesh-like conductive wire pattern 70. A wiring 40 formed using conductive ink or conductive paste is connected to one end side of each X electrode 30.

  FIG. 6 is an enlarged view of the sensor unit 30 </ b> A constituting the X electrode 30. The sensor unit 30 </ b> A is formed in a rhombus (here, a square) by the crossed conductor patterns 70. Adjacent sensor portions 30A are connected to each other via a conductive portion C including a bent conductive thin wire, whereby an X electrode 30 that is a sensor array is formed. In addition, short conductive thin wires that are isolated from other conductive thin wires are arranged around each sensor unit 30A, and these conductive thin wires are dummy electrodes Dm.

  The length of one side of the sensor unit 30A 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 sensor unit 30A (the interval between the conductor patterns 70 (the dimension between the lines)) is preferably 50 to 500 μm, and 150 to 300 μm. More preferably. When the length of the side of the unit cell is in the above range, it is possible to keep the transparency better, and the display can be visually recognized without discomfort when attached to the front surface of the display device.

FIG. 7 shows the surface of the electrode sheet 25 on which the Y electrode 35 is formed. On the support 10, a plurality of Y electrodes 35 formed of a conductive wire pattern 70 (FIG. 1) are arranged in the Y direction.
Each Y electrode 35 is formed by conducting a plurality of sensor portions 35A formed in a diamond shape. A wiring 45 formed using conductive ink or conductive paste is connected to one end side of each Y electrode 35.

Each wiring 45 extends along the side of the support 10 and is collected in a contact portion (not shown) provided at the end of the support 10. Each wiring 45 is connected to a circuit board for driving and controlling the touch panel by FPC (Flexible printed circuits) (not shown) provided in the contact portion.
On the other hand, the wiring 40 on the surface on which the X electrode 30 is formed is drawn out to the back surface (surface on which the wiring 45 is formed) side of the support 10 through the through hole 48 in the case of the touch panel 1 in FIG. The circuit board is connected by an FPC provided on the back surface of the support 10. In this way, the wiring formed on one surface of the support 10 using the through hole 48 is drawn out to the other surface, so that it is sufficient to provide the FPC only on one surface, so that the wiring can be facilitated.
In the other touch panels 2 to 4, the wiring 40 on the surface on which the X electrode 30 is formed is connected to the circuit board by an FPC or the like provided on the surface of the support 10.

  FIG. 8 is an enlarged view of the sensor unit 35 </ b> A constituting the Y electrode 35. The sensor unit 35A is formed in the same manner as the sensor unit 30A of the X electrode 30, and the adjacent sensor units 35A are connected to each other via the conduction unit C, whereby the Y electrode 35 that is a sensor array is formed.

  The X electrode 30 and the Y electrode 35 are seen through from the touch surface 11 </ b> A side in a state of being overlapped as illustrated in FIGS. 1 to 4. In the fluoroscopic state, a sensor surface is formed in which the sensor units 30A and the sensor units 35A are alternately arranged in a plane. At this time, the dummy electrode Dm is disposed between the adjacent sensor unit 30A and the sensor unit 35A. Since the lattice pattern of the conductive wire pattern is made uniform by the dummy electrode Dm, it is possible to solve a visual problem such as unevenness. Further, since the parasitic capacitance between the adjacent electrodes 30 and 30 (or the electrodes 35 and 35) is reduced due to the presence of the dummy electrode Dm, a short circuit during high frequency driving can be prevented.

The electrodes 30 in FIG. 6 and the electrodes 35 in FIG. 8 are substantially perpendicular to each other in the conduction direction (the array direction of the sensor array), but can be set to any angle as long as there is no problem in determining the coordinates of the touch position.
Furthermore, the direction of the conductive thin wires constituting the square lattice (which may be a rectangular lattice) illustrated in FIGS. 6 and 8 is 45 ° with respect to the X and Y directions. For this reason, when the touch panel and the display are bonded together with the X and Y directions as the directions of the electrode axes of the display, moire is unlikely to occur.

[Construction of conducting wire pattern and wiring]
FIG. 9 schematically shows a connection portion between the conductor pattern 70 and the wiring 40 shown in FIG. As shown in FIG. 9, the wiring is preferably provided so as to cover at least a part of the electrode. 9A is a plan view of a connecting portion between the conductive wire pattern 70 and the wiring 40, and FIG. 9B is a cross-sectional view taken along the line BB of FIG. 9A.
As shown in FIG. 9A, the conductor pattern 70 and the wiring 40 are in contact with each other at the portion where the conductor pattern 70 is indicated by a broken line and the portion where the wiring 40 overlaps (the hatched portion). The area of the portion (shaded portion) where the wiring 40 overlaps is the contact area between the conductor pattern 70 and the wiring 40.
Although not shown, the wiring 45 shown in FIG. 7 is also connected to the end of the conductive pattern 70 in the same manner as the wiring 40, and the contact state between the conductive pattern 70 and the wiring 45 is shown in FIG. The contact state between the conductor pattern 70 and the wiring 40 is the same.

It is preferable that the line width of the conductive thin wire which comprises the conducting wire pattern 70 is 20 micrometers or less, and the conducting wire pattern 70 can be stably manufactured to the line width of 20 micrometers or less by the developing silver system manufacturing method mentioned later. Thus, since the aperture ratio of an electrode rises because the line | wire width of the conducting wire pattern 70 is thin, the transmissivity of a touchscreen improves. The line width of the conductor pattern 70 is more preferably 1 μm or more and 10 μm or less, and further preferably 2 μm or more and 6 μm or less. When the thickness is in the range of 1 μm or more and 10 μm or less, a low-resistance electrode can be formed relatively easily.
Further, the thickness of the conductive wire pattern 70 is preferably 0.1 μm or more and 1.5 μm or less, more preferably 0.4 μm or more and 1.5 μm or less, and 0.2 μm or more and 0.8 μm or less. More preferably it is. When the thickness is in the range of 0.1 μm or more and 1.5 μm or less, a low-resistance electrode that is excellent in durability can be formed relatively easily. In the present invention, the thickness of the electrode is the thickness of the conductor pattern.

  Here, as shown in FIG. 9B, the conductive wire pattern 70 includes an electrode 71 made of a conductive thin wire that is developed silver, and a protective layer 72 provided on the opposite side of the electrode 71 from the support 10 side. It is configured to include. The protective layer is preferably an organic binder layer. The protective layer is provided so as to cover at least the electrode, but it is preferable to cover the upper surface side (the side opposite to the support) of the electrode and the side surface of the electrode. Further, as shown in FIG. 9B, the protective layer may be provided so as to cover the electrode and the support.

  The protective layer 72 is formed on the photosensitive layer in order to exhibit the effect of preventing scratches and improving mechanical properties. The formation method of this protective layer 72 is not specifically limited, For example, it can select suitably from the well-known coating method.

The thickness t of the protective layer 72 is 0.3 μm or less, more preferably 0.05 μm or more and 0.3 μm or less, and still more preferably 0.05 μm or more and 0.2 μm or less. Such a thickness t makes it difficult for poor conduction between the wiring 40 and the conductor pattern 70 with the protective layer 72 interposed therebetween.
Moreover, by setting it as such thickness t, scratch resistance can be improved. In particular, when the thickness t is 0.05 μm or more, the protective layer 72 reliably covers the electrode 71 and adheres closely to the electrode 71, so that scratch resistance can be ensured.

  As described above, by setting the thickness t of the protective layer 72 to 0.3 μm or less, pressure resistance can be increased and conduction failure can be prevented, and there is no problem in insulation between the formed electrodes. Handling is improved. Further, as will be described later, by setting the thickness ratio of the wiring and the electrode to 3 or more, the durability test is not hindered.

  The protective layer 72 includes a binder, inorganic fine particles, a surfactant, and the like. The binder is gelatin or a high molecular polymer, and gelatin is preferable. As the inorganic fine particles, oxide fine particles such as silica and alumina are used, and the particle diameter is 0.005 to 0.3 μm, preferably 0.01 to 0.2 μm. Silica is preferable as the inorganic fine particles, and colloidal silica can be used.

As colloidal silica, for example, manufactured by Nissan Chemical Industries, Ltd .: Snowtex XS (particle diameter 4 to 6 nm), Snowtex OXS (particle diameter 4 to 6 nm), Snowtex S (particle diameter), which have excellent binding power among the Snowtex series 8-11 nm), Snowtex OS (particle diameter 8-11 nm), Snowtex 20 (particle diameter 10-20 nm), Snowtex 30 (particle diameter 10-20 nm), Snowtex 40 (particle diameter 10-20 nm), Snow Tex O (particle diameter 10-20 nm), Snowtex N (particle diameter 10-20 nm), and Snowtex C (particle diameter 10-20 nm), or Snowtex PS-S (particle diameter 20-30 nm) with excellent film properties Snowtex PS-M (particle diameter 40-50 nm) or the like can be used.
By adding colloidal silica, the scratch strength of the protective layer 72 can be increased, thereby increasing the hardness. The scratch strength of the protective layer is preferably 8 g or more, more preferably 9 g or more, further preferably 10 g or more, and particularly preferably 15 g or more.
The scratch strength can be measured as follows.
After conditioning the unexposed photosensitive material for 24 hours under conditions of 23 ° C. and 55% relative humidity, a sapphire needle with a radius of curvature of the tip of 0.1 mm is applied at right angles to the coated surface at 60 cm / min. While moving the sample, gradually increase the load on the sapphire needle from 0g to 100g, develop the sample, observe the part scanned by the sapphire needle with a loupe, and determine the load at which fogging starts to occur To do.

The protective layer preferably contains any one of colloidal silica, silica mat, silicone oil, paraffinic oil, and other compounds that are soluble in the solvent of the conductive ink or conductive paste. Colloidal silica, silica mat It is more preferable to contain at least one of silicone oil, paraffinic oil, and (meth) acrylic particles. By adding the above materials, it is considered that the connection between the protective layer and the wiring material (conductive paste) is strengthened, and durability can be improved. In particular, by adding a compound that dissolves in the solvent of the conductive paste, when the conductive paste is printed on the protective layer, the compound dissolves in the conductive paste solvent and escapes, and the compound in the protective layer is present. It is presumed that the conductivity is improved by the paste liquid entering the place (anchor effect).
Examples of the colloidal silica include the same ones as described above.
As the silicone oil, those having a polymerization number of polysiloxane constituting the silicone oil of preferably 2 to 100, more preferably 5 to 20 can be suitably used.
As the paraffinic oil, those having a paraffinic hydrocarbon constituting the paraffinic oil of preferably 2 to 1000, more preferably 5 to 100 can be suitably used.
The silica mat preferably has an average particle size of 5 μm or less, more preferably 0.5 to 3.5 μm. The particle size variation coefficient is preferably 3 to 50, and particularly preferably 3 to 30%.
Examples of the compound that dissolves in the solvent of the conductive ink or conductive paste include silicone oil, paraffin oil, and (meth) acrylic particles, and silicone oil or paraffin oil is particularly preferable.

The addition amount of the colloidal silica in the protective layer is preferably from 0.5 to 50 mg / ^{m 2,} more preferably 5 to 30 mg / ^{m 2,} more preferably 10-20 mg / ^{m 2.}
The addition amount of the silicone oil in the protective layer is preferably from 5 to 100 mg / ^{m 2,} more preferably 10 to 80 mg / ^{m 2,} more preferably 30 to 70 mg / ^{m 2.}
5-100 mg / m < ² > is preferable, as for the addition amount of the paraffinic oil in a protective layer, 10-80 mg / m < ² > is more preferable, and 30-70 mg / m < ² > is still more preferable.
The addition amount of the (meth) acrylic particles in the protective layer is preferably from 50 to 400 mg / ^{m 2,} more preferably 100 to 300 mg / ^{m 2,} more preferably 150 to 250 / ^{m 2.}

The wirings 40 and 45 are preferably formed by printing, coating or the like of conductive ink. This conductive ink contains conductive particles such as silver particles and Al particles, or conductive fillers such as silver filler and Al filler. As the conductive ink (conductive paste), for example, Fujikura Kasei Co., Ltd .: Dotite series XA-436 (volume resistivity 7 × 10 ⁻⁵ Ω · cm), FA-401CA (volume resistivity 3 × 10 ⁻⁵ Ω) Cm), FA-333 (volume resistivity 4 × 10 ⁻⁵ Ω · cm), FA-353N (volume resistivity 4 × 10 ⁻⁵ Ω · cm), and the like can be used. In addition, volume resistivity (measured at a film thickness of 10 μm) of 2 × 10 ^{−5 to} 5 × 10 for flat screen, rotary screen, flexo, and gravure, which are product groups of Toyo Ink Corporation: REXALPHA series. ^-5 Ω · cm products are also commercially available, and these can also be used.

Here, the thickness and line width of the wirings 40 and 45 are determined in consideration of the material resistivity of the conductive ink, the volume resistivity given by the product selection, and the like.
The thickness of the wirings 40 and 45 is preferably 0.4 μm to 1.5 μm, and the thickness is larger than the thickness of the conductor pattern 70. More preferably, the thickness of the wirings 40 and 45 is 5 μm to 15 μm.
The line width of the wirings 40 and 45 is preferably 20 μm to 100 μm, and the line width is wider than the line width of the conductor pattern 70. A more preferable line width of the wirings 40 and 45 is 20 μm to 50 μm.
Furthermore, the distance between the wirings 40 and 40 and the distance between the wirings 45 and 45 (dimensions between the lines) are preferably 50 μm to 200 μm, and more preferably 50 μm to 100 μm.

As described above, the wiring 40 formed of the conductive ink is connected to the conductive wire pattern 70 formed by the developed silver system, and the connecting portion between the conductive wire pattern 70 and the wiring 40 has a contact resistance. In order to control this contact resistance, the area of the portion where the wiring 40 covers the electrode 30 (or the electrode 35) is preferably 1 × 10 ⁻⁸ m ² or more, and preferably 3 × 10 ⁻⁸ m ² or more. Is more preferable. When the area is 1 × 10 ⁻⁸ m ² or more, the continuity of the connection portion between the wiring and the electrode after the durability test can be improved. The thickness of the protective layer 72 described above is determined in consideration of conduction failure due to contact resistance between the conductive pattern 70 and the wiring 40.

  From the viewpoint of improving the continuity of the connection between the wiring and the electrode after the durability test, the ratio of the thickness of the electrode and the wiring (thickness of the wiring) / (thickness of the electrode) is 3 or more, and 5 or more. Preferably, it is 10 or more.

The electrical characteristics of the electrodes and wiring configured as described above will be described.
The volume resistivity of the electrodes (each of the electrodes 30 and 35) is, for example, 5 to 100 μΩ · cm, and preferably 5 to 50 μΩ · cm.
On the other hand, the volume resistivity of the wirings 40 and 45 formed of conductive ink containing Ag particles is preferably 3 to 20 μΩ · cm, and more preferably 3 to 8 μΩ · cm, for example. The wirings 40 and 45 (conductive ink) are easy to form thicker than the thickness of the conductor pattern 70.

  As described above, according to the touch panel of this embodiment including the electrodes 30 and 35 formed in an ultrafine pattern by the developed silver system and the wirings 40 and 45 formed of conductive ink, the display quality of the display is shown. Can be provided and a low-resistance touch panel can be provided. In this touch panel, since the thickness of the protective layer 72 is effective under optimum conditions both for the conduction between the conductor pattern 70 and the wirings 40 and 45 and for the pressure resistance of the conductor pattern 70, the electrode does not deteriorate the yield. In addition, the total resistance of the wiring can be reduced. Thereby, since the subject about the power consumption and response speed accompanying the enlargement of a touchscreen is solved, the enlargement of a touchscreen can be promoted.

[Photosensitive material]
FIG. 10 shows a photosensitive material 05 used for manufacturing the electrode sheets 20 and 25 described above.
The photosensitive material 05 has a photosensitive layer containing a silver halide emulsion formed on both sides (a front surface and a back surface) of a support, and is used for manufacturing an electrode sheet.
A typical structure of the photosensitive material will be described with reference to FIG. An upper photosensitive material layer (also referred to as a front surface photosensitive material layer) 50 is formed on the front surface side of the support 10, and a lower photosensitive material layer (also referred to as a back surface photosensitive material layer) 60 is formed on the back surface side. Has been.
In the upper photosensitive material layer 50, an undercoat layer 56, an antihalation layer 57, an upper photosensitive layer (also referred to as a front photosensitive layer) 51 containing a silver halide emulsion, and a protective layer 72 are formed on the support 10. ing. The undercoat layer and the antihalation layer are layers provided as necessary. The upper photosensitive layer 51 may be formed of a photosensitive layer containing several silver halide emulsions and an intermediate layer between these photosensitive layers. The lower photosensitive material layer 60 also has the same layer structure as the upper photosensitive material layer 50 (an undercoat layer 66, an antihalation layer 67, a lower photosensitive layer (also referred to as a back side photosensitive layer) 61, and a protective layer 72). A symmetric layer structure around the center is preferable.

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

The mode (1) is a black-and-white development type, and a light-transmitting conductive film such as a light-transmitting electromagnetic wave shielding film is formed on the photosensitive material. The developed silver obtained is chemically developed silver or heat developed silver, and is a filament with a high specific surface. Further, 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 electrode 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 electrode 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 the production of the transparent electrode 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. The “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 may be any of chlorine, bromine, iodine and fluorine, or a combination thereof. For example, silver halides mainly composed of silver chloride, silver bromide and silver iodide are preferably used, and silver halides mainly composed of silver bromide and silver chloride are preferably used. Silver chlorobromide, silver iodochlorobromide and silver iodobromide are also preferably used. More preferred are silver chlorobromide, silver bromide, silver iodochlorobromide and silver iodobromide, and most preferred are silver chlorobromide and silver iodochlorobromide containing 50 mol% or more of silver chloride. Used.

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

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

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

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

  The volume ratio of silver and binder contained in the photosensitive layers 51 and 61 formed on both sides of the support is preferably 1.0 or more, and more preferably 1.5 or more. By setting the volume ratio of silver and binder to 1.0 or more, the conductivity of developed silver after development processing can be increased. The volume ratio of silver and binder is obtained by calculating the mass of silver and the mass of binder contained in the silver halide emulsion layer, and calculating the density of silver as 10.5 and the density of binder as 1.34. And

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

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

(Protective layer)
The protective layer 72 described above is provided on the photosensitive layers 51 and 61.
(Other layer structure)
Antihalation layers 57 and 67 can be provided between the photosensitive layer of the present invention and the support. Regarding the material used for the antihalation layer and the method of using the same, the description in paragraphs 29 to 32 of JP-A-2009-188360 can be referred to. The optical density of the antihalation layer varies depending on the intensity and wavelength of exposure light, but is preferably about 0.5 to 3.0.

〔Production method〕
Next, a method for manufacturing the touch panel described above will be described. Here, the manufacturing process of the touch panel 1 shown in FIG. 1 will be described as an example.
FIG. 11 shows a pattern forming process for forming the silver conducting wire pattern 70 on the support 10.
11A shows the support 10, and FIG. 11B 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 support by coating. (C) represents a diagram of the photosensitive material of the present invention exposed through a photomask, and (d) represents a developed silver electrode formed by a development fixing process subsequent to exposure. Below, each process after exposure is demonstrated.

〔exposure]
Since the photosensitive material 05 of the present invention is a photosensitive material having a photosensitive layer formed on both sides of a support, in the present invention, light is irradiated 102a and 102b on both sides of the photosensitive material as shown in FIG. Exposure. Light irradiation is performed on the photosensitive material through photomasks 110 and 120. Since the photomasks 110 and 120 are masks used for forming the conductive pattern 70 with developed silver, the photomasks 110 and 120 are masks that transmit light in portions corresponding to the thin lines of the electrodes in FIGS. is there. Therefore, the photomasks 110 and 120 are not the same, but are masks with different patterns. As described above, 111 and 121 are mask openings, and 112 and 122 are mask light shielding portions. The light transmitted through the opening of the mask forms a latent image on the silver halide emulsion at portions 131 and 141 of the photosensitive layer. The portions 131 and 141 where the latent image is formed form a developed silver pattern by the next development process. In the unexposed portions 132 and 142 of the photosensitive material that are not exposed by the light shielding portion of the mask, the silver halide emulsion grains that are not exposed by the fixing process are dissolved and flow out of the layers to form transparent films 152 and 162.

  As described above, when exposure is performed from both sides of the photosensitive material using masks having different patterns, the following problems occur. The light transmitted 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 transmits through the support, and an unexpected latent image is also formed on the photosensitive layer 61 on the opposite surface. Will be formed. Such a problem is difficult only by adjusting the exposure amount, and can be dealt with by providing the photosensitive material with antihalation layers 57 and 67 having an optical density that absorbs light transmitted through the photosensitive layer 51. Another method is to change the color sensitivity of the silver halide emulsions of the photosensitive layers 51 and 61 with a sensitizing dye.

  FIG. 12 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. 12, the positioning of the two exposure apparatuses is strictly performed. Strict positioning is performed so that the silver image formed by the photomasks 110 and 120 has a uniform pattern. In the aspect as shown in FIGS. 2 to 4 in which the two electrode sheets 20 and 25 are combined to form the touch panel 2 to 4, it is necessary to position the two electrode sheets 20 and 25 for each set. Productivity is greatly inferior compared to the double-sided type as in this case.

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. Furthermore, a light source having a wavelength distribution may be used for exposure, or a light source having a specific wavelength may be used.
The exposure method may be a surface exposure as shown in FIG. 12, or a scanning exposure instead of using a mask as shown in FIG.

As described above, both the surface of the photosensitive material for producing an electrode sheet of the present invention are subjected to image-like pattern exposure, and then developed, whereby a front surface transparent electrode composed of developed thin conductive silver wires and development. Backside transparent electrodes made of silver conductive fine wires can be formed on both sides of the support (pattern forming step).
In addition, the electrode sheet formed as described above is exposed so that the conduction direction of the front transparent electrode and the conduction direction of the back transparent electrode are arranged orthogonal to each other, and then developed. It is formed.

(Development processing)
In the present 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 05, more preferably 500 ml / ^{m 2} or less, 300 ml / ^{m 2} or less is particularly preferred.

The photosensitive material 05 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.

  Next, a wiring forming process for forming the wirings 40 and 45 using a conductive ink or a conductive paste is performed. As the conductive ink, a general ink can be used. Moreover, the conductive paste and conductive ink described in JP2009-99561A can also be used.

A transparent electrode sheet is obtained through the above steps. The surface resistance of the obtained transparent electrode 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.
The volume resistivity of the obtained transparent electrode sheet is preferably 160 μΩ · cm 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 electrode sheet that has been developed. This significantly increases the conductivity of the transparent electrode 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), 699.4 kgf / cm 2 or more when converted to surface pressure, more preferably 2940 N / cm (300 kgf / cm, 935.8 kgf / cm ² when converted to surface pressure). ) That's it. The upper limit of the linear pressure is 6880 N / cm (700 kgf / cm) or less.
The application temperature of the smoothing treatment represented by the calender roll is preferably 10 ° C. (no temperature control) to 100 ° C., and the more preferable temperature varies depending on the line density and shape of the metal mesh pattern and metal wiring pattern, and the binder type. , Approximately 10 ° C. (no temperature control) to 50 ° C.

(Treatment in contact with steam)
In the manufacturing method of the present embodiment, the smoothed conductive pattern may be brought into contact with steam (steam contact process). In this vapor contact step, the smoothed transparent electrode sheet is brought into contact with superheated steam, and the smoothed conductive wire pattern 70 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 electrode 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 this Embodiment, the smoothing process mentioned above may be performed and a plating process may be performed with respect to a transparent electrode sheet. By plating, the surface resistance can be further reduced and the conductivity can be increased. The smoothing treatment may be performed either before or after the plating treatment. However, by performing the smoothing treatment before the plating treatment, the plating treatment is made efficient and a uniform plating layer is formed. The plating treatment may be electrolytic plating or electroless plating. Further, the constituent material of the plating layer is preferably a metal having sufficient conductivity, and copper is preferable.

(Oxidation treatment)
In the present embodiment, it is preferable to oxidize the transparent electrode sheet after the development process and the conductive metal part formed by the plating process. 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 electrode sheet of the present invention is preferably used for a touch panel, particularly a capacitive touch panel.

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

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

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

1 liquid:
750 ml of water
Gelatin (phthalated gelatin) 8g
Sodium chloride 3g
1,3-Dimethylimidazolidine-2-thione 20mg
Sodium benzenethiosulfonate 10mg
Citric acid 0.7g
Two liquids:
300 ml of water
150 g silver nitrate
3 liquids:
300 ml of water
Sodium chloride 38g
Potassium bromide 32g
Hexachloroiridium (III) potassium salt
(0.005% KCl 20% aqueous solution) 5 ml
Ammonium hexachlororhodate
(0.001% NaCl 20% aqueous solution) 7 ml
4 liquids:
100ml water
Silver nitrate 50g
5 liquids:
100ml water
Sodium chloride 13g
Potassium bromide 11g
Yellow blood salt 5mg

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

(Preparation of photosensitive layer coating solution)
1,3,3a, 7-tetraazaindene 1.2 × 10 ⁻⁴ mol / mol Ag, hydroquinone 1.2 × 10 ⁻² mol / mol Ag, citric acid 3.0 × 10 ⁻⁴ mol / Mol Ag, 2,4-dichloro-6-hydroxy-1,3,5-triazine sodium salt 0.90 g / mol Ag, a trace amount of hardener was added, and the coating solution pH was adjusted to 5.6 using citric acid. To prepare a photosensitive layer coating solution. Based on the composition of the photosensitive layer coating solution, the amount of gelatin added was adjusted to prepare a coating solution.

(Preparation of protective layer coating solution)
In Example 1, a coating aid was prepared by adding a coating aid to an aqueous gelatin solution. This coating solution was coated on a support so as to give gelatin of 0.3 g / m ² .
In Example 2, the coating solution and the coating amount were adjusted so that the gelatin coating amount was 0.2 g / m ² compared to Example 1.
In Example 6, with respect to Example 1, the coating solution and the coating amount were adjusted so that the gelatin coating amount was 0.05 g / m ² .
In Example 7, with respect to Example 1, the coating solution and the coating amount were adjusted so that the gelatin coating amount was 0.1 g / m ² .
In Examples 11 to 12, with respect to Example 1, the coating solution and the coating amount were adjusted so that the gelatin coating amount was 0.3 g / m ² .
In Example 3, a coating aid, colloidal silica (Snowtex C, manufactured by Nissan Chemical Industries, Ltd., particle size: 10 to 20 nm) was added to an aqueous gelatin solution to prepare a coating solution. This coating solution was coated on a support so that gelatin was 0.3 g / m ² and colloidal silica was 10 mg / m ² .
In Examples 4 and 5, colloidal silica was applied to Example 3 so as to be 20 mg / m ² .
In Example 8, a coating aid and the following silicone oil (median value of particle size distribution: 0.18 μm, manufactured by Shin-Etsu Chemical Co., Ltd.) were added to an aqueous gelatin solution to prepare a coating solution. This coating solution was coated on a support so that gelatin was 0.3 g / m ² and silicone oil was 50 mg / m ² .

In Example 9, a coating aid and the following liquid paraffin (median particle size distribution: 1.8 μm, manufactured by ISP) were added to an aqueous gelatin solution to prepare a coating solution. This coating solution was coated on a support so that gelatin was 0.3 g / m ² and liquid paraffin was 50 mg / m ² .
_{- (CH 2) n- (n} = 15~50)
In Example 10, a coating aid and polymethyl methacrylate (PMMA) particles (median size distribution: 3.0 μm, manufactured by Fujikura Kasei Co., Ltd.) were added to an aqueous gelatin solution to prepare a coating solution. This coating solution was coated on a support so that gelatin was 0.3 g / m ² and PMMA particles were 200 mg / m ² .

After a corona discharge treatment is applied to a 100 μm polyethylene terephthalate (PET) film, a gelatin subbing layer having a thickness of 0.1 μm, and further, a dye that has an optical density of about 1.0 and is decolorized by an alkali of the developer on the subbing layer An antihalation layer was provided as a support. The photosensitive layer coating solution prepared and prepared above was applied to this support.
A protective layer coating solution was applied on the photosensitive layer so that the thickness of the protective layer was 0.3 μm. The photosensitive layer and the protective layer were coated using a simultaneous coating machine to prepare a photosensitive material.

(Exposure and development processing)
Next, the photosensitive material prepared above was exposed. A high pressure mercury lamp was used as the light source, and exposure was performed using the mask for pattern formation shown in FIG. The light transmission windows of the mask used have the same pattern as that in FIG. 6, the line width of the conductor pattern is 3 μm, and the side length of the grating is 300 μm.
After exposure, the film was developed with the following developer, developed with a fixer (trade name: N3X-R for CN16X: manufactured by Fuji Film Co., Ltd.), rinsed with pure water, and dried. In this way, an electrode made of a conductive thin wire containing developed silver was produced (volume resistivity 15 μΩcm).

(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

(Creation of wiring)
At the end of the conductor pattern created as described above, Fujikura Kasei Co., Ltd .: Dotite series FA-401CA (volume resistivity 3 × 10 ⁻⁵ Ω · cm) was used as the conductive ink, and the film thickness was 10 μm. A wiring having a line width of 100 μm was formed by screen printing.

The electrode sheet of Example 1 was obtained as described above.
In Example 1, the amount of gelatin added was changed so that the thickness of the protective layer shown in Table 2 below was changed, and the amount of additive added was changed so that the additive concentration shown in Table 2 was changed. Except having provided, the electrode sheet of Examples 2-4 and 6-10 was created similarly to Example 1. FIG. In Example 5, in Example 4, it changed so that the area of the part which wiring may cover an electrode might become what was shown in following Table 2. FIG. In Example 11, the thickness of the wiring in Example 1 was changed as shown in Table 2 below. In Example 12, the area where the wiring covered the electrode in Example 11 was changed to the one shown in Table 2 below.
Further, Comparative Example 1 was obtained in the same manner as in Example 1 except that the amount of gelatin added was changed so that the thickness of the protective layer was 0.4 μm. In Comparative Example 2, no protective layer was provided. In Comparative Example 3, the thickness ratio between the wiring and the electrode was 2.5.

(Evaluation)
The following evaluation was performed using the transparent electrode sheet (Examples 1-12 and Comparative Examples 1-3) created above.

(1) Conductivity of connection part The resistance value between the electrode 71 and the wiring 40 shown in FIG. 9 was directly read, and conduction was confirmed.
Evaluation ◎ Energization of all wiring was confirmed.
Evaluation ○ Energization could not be confirmed with less than 1% of all wiring, and energization was confirmed with the remaining wiring.
Evaluation △ Energization could not be confirmed in 1% or more and less than 5% of all wiring, and energization was confirmed in the remaining wiring.
Evaluation × There are 5% or more of the wiring that cannot be energized.

(2) Conductivity of connection part after endurance test After aging for 240 hours under the condition of 60 ° C. and 90%, a test apparatus for scratching is used for each of the entire surface and back surface of the electrode sheet. Then, an endurance test on the pressure resistance of reciprocating the friction member 1000 times was performed, and then the resistance value between the electrode 71 and the wiring 40 shown in FIG. Conductivity was evaluated.

(3) Electrode short circuit due to fogging of photosensitive material The electrode sheet was connected to the circuit board via FPC, the insulation resistance between adjacent electrodes was measured, the number of electrodes that were 5 MΩ or less was counted, and the following evaluation was made. . Here, the adjacent electrodes are, for example, 30-1 and 30-2 shown in FIG.
Evaluation: The number of electrodes having an insulation resistance of less than 5 MΩ is less than 1% of the total number of electrodes.
Evaluation ○ The number of electrodes having an insulation resistance of less than 5 MΩ is less than 5% of the total number of electrodes.
Evaluation x The number of electrodes whose insulation resistance is less than 5 MΩ is 5% or more of all the electrodes.

(4) Scratch strength After conditioning the unexposed photosensitive material for 24 hours under conditions of 23 ° C. and 55% relative humidity, a sapphire needle having a radius of curvature of the tip of 0.1 mm is applied to the application surface at a right angle. The load applied to the sapphire needle is gradually increased from 0 g to 100 g while moving the sample at 60 cm / min, the sample is developed, the portion scanned by the sapphire needle is observed with a loupe, and the load at which fogging starts to occur It was measured by seeking.

  The evaluation results are summarized in Table 2 below.

From the above, the following can be understood.
In Examples 1 to 12 in which the thickness of the protective layer is 0.3 μm or less and (thickness of wiring) / (thickness of electrode) is 3 or more, the conductivity of the connection portion between each wiring and electrode is good, and the scratch strength is high. Excellent, excellent conductivity after durability test, and no short circuit of electrodes.
When Example 1 is compared with Examples 6 and 7, it can be seen that Examples 6 and 7 in which the protective layer is thinner have further improved conductivity. On the other hand, in Comparative Example 1 in which the protective layer thickness exceeds 0.3 μm, the conductivity is poor.
It can be seen that the conductivity of the connection part after the durability test is particularly excellent when the protective layer contains colloidal silica, silica mat, silicone oil, paraffinic oil, or (meth) acrylic particles as additives. (Examples 3, 4, 8 to 10).
About the short circuit of an electrode, although it cannot be said that it is very good like the case of the comparative example 1 (0.4 micrometer) with a large thickness of a protective layer, the good level is maintained through Examples 1-12.
Furthermore, the conductivity after the durability test in Examples 3 and 4 in which the contact area between the wiring and the conductive pattern (the area of the portion where the wiring covers the electrode) is 3 × 10 ⁻⁸ m ² or more is 1 × It is better than the conductivity after the durability test in Example 5 which is 10 ⁻⁸ m ² . That is, by increasing the contact area between the wiring and the conductor pattern to 3 × 10 ⁻⁸ m ² or more, the conductivity after the durability test can be more reliably maintained.

Dm Dummy electrode C Conducting portion w Line width 1 to 4 Touch panel 05 Photosensitive material 10 Support body 11 Transparent cover member 11A Touch surface 12 Transparent cover member 13 Dielectric layer 20, 25 Electrode sheets 30, 35, 30-1, 30-2 Electrode 30A, 35A Sensor unit 31 Sensor unit 40, 45 Wiring 48 Through hole 50 Upper photosensitive material layer 51, 61 Photosensitive layer 55, 65 Protective layer 56, 66 Undercoat layer 57, 67 Antihalation layer 60 Lower photosensitive material layer 70 Conductive pattern 71, 151, 161 Electrode 72 Protective layer 100a Light source 101a, 101b Lens 102a, 102b Parallel light 110 Photomask 111 Opening 132 Unexposed part 152, 162 Transparent film

Claims (14)

An electrode sheet having an electrode, a protective layer covering the electrode, and a wiring electrically connected to the electrode on at least one surface of the support,
The electrode is composed of a conductive thin wire containing developed silver,
The wiring is formed of conductive ink or conductive paste,
The protective layer has a thickness of 0.3 μm or less, and
An electrode sheet having a ratio of the thickness of the electrode to the wiring (thickness of the wiring) / (thickness of the electrode) of 3 or more.   The electrode sheet according to claim 1, wherein the conductive fine wire containing developed silver is obtained by exposing and developing a photosensitive material having a silver halide emulsion layer.   The electrode sheet according to claim 1 or 2, wherein the protective layer has a thickness of 0.05 µm or more and 0.3 µm or less.   The electrode sheet according to any one of claims 1 to 3, wherein the protective layer contains at least one of colloidal silica, silica mat, silicone oil, paraffinic oil, and (meth) acrylic particles.   The electrode sheet according to any one of claims 1 to 4, wherein the protective layer contains colloidal silica. The said wiring is provided so that at least one part of the said electrode may be covered, The area which the said wiring covers the said electrode is 1 * 10 < ^-8 > m < ² > or more, It is any one of Claims 1-5. Electrode sheet.   The electrode sheet as described in any one of Claims 1-6 whose line | wire width of the said electroconductive thin wire is 20 micrometers or less.   The electrode sheet as described in any one of Claims 1-7 whose thickness of the said electrode is 0.4 micrometer or more and 1.5 micrometers or less.   The electrode sheet according to any one of claims 1 to 8, wherein the protective layer has a scratch strength of 9 g or more.   The electrode sheet according to claim 1, wherein the conductive ink or the conductive paste contains silver particles or a silver filler.   The electrode sheet according to any one of claims 1 to 10, wherein the electrode and the wiring are respectively formed on both surfaces of the support.   The through hole of the said support body which takes out the electric potential of the said wiring provided in the one surface of a support body to the other surface of a support body was formed with the conductive ink or the conductive paste. The electrode sheet according to any one of the above. On at least one surface of the support, there is an electrode composed of a pattern made of a conductive thin wire containing developed silver, a protective layer having a thickness of 0.3 μm or less covering the electrode, and a wiring electrically connected to the electrode. And the ratio of the thickness of the electrode and the wiring (thickness of wiring) / (thickness of electrode) is 3 or more,
An electrode forming step of forming an electrode composed of a conductive fine wire containing developed silver by exposing and developing a photosensitive material having a silver halide emulsion layer and a protective layer in this order on a support;
A method of manufacturing an electrode sheet, comprising: a wiring forming step of forming a wiring that is conducted to an electrode configured by a pattern made of the conductive thin wire using a conductive ink or a conductive paste.   A touch panel provided with the electrode sheet according to any one of claims 1 to 12, or the electrode sheet produced by the production method according to claim 13.

Images