WO2014061591A1 - Electrically conductive sheet, and touch panel - Google Patents

Abstract

Provided are an electrically conductive sheet with improved visibility, and a touch panel. In an electrically conductive sheet (1), a first electrode layer (10) having a plurality of columns of first electrodes (12), a transparent insulation layer (30), and a second electrode layer (40) having a plurality of columns of second electrodes (42) are stacked in that order. The first electrodes (12) include a plurality of first lattices (26), the plurality of first lattices (26) including M × N lattice groups. The second electrodes (42) include a plurality of second lattices (56), the plurality of second lattices (56) including M × N lattice groups. The first electrode layer (10) and the second electrode layer (40) are disposed such that the plurality of first lattices (26) and the plurality of second lattices (56) do not overlap each other, and such that, when viewed from above, the plurality of first lattices (26) and the plurality of second lattices (56) are continuous on an entire surface. M and N are integers such that M + N ≤ 9.

Description

Conductive sheet and touch panel

The present invention relates to a conductive sheet and a touch panel.

In recent years, many touch panels have been used as input devices for mobile terminals and computers. A touch panel is arrange | positioned on the surface of a display, detects the contact position, such as a finger | toe, and performs input operation. A capacitance method or the like is known as a position detection method for a touch panel.

For example, in a capacitive touch panel, ITO (indium tin oxide) is used as a material for the transparent electrode pattern from the viewpoint of visibility. However, since ITO has a high wiring resistance and does not have sufficient transparency, use of a transparent electrode pattern using a thin metal wire for a touch panel has been studied.

For example, in Patent Documents 1-4, a plurality of first electrodes configured by a grid of fine metal wires and arranged in parallel in one direction and a plurality of first electrodes configured by a grid of metal fine wires and arranged in parallel in a direction orthogonal to the first electrode. A touch panel including a conductive sheet including a plurality of second electrodes is disclosed.

International Publication No. 2010/013679 Pamphlet International Publication No. 2011-0662301 Pamphlet JP 2011-237839 A Special table 2012-508937 gazette

1st electrode and 2nd electrode which comprise the above-mentioned electrically conductive sheet contain the area | region where the metal fine wire grid | lattice is arrange | positioned, and the area | region where the metal fine wire grid | lattice is not arrange | positioned. The conductive sheet is configured so that the grid-like fine metal wires are uniformly arranged on the entire surface in a plan view by superimposing the first electrode and the second electrode. This improves the visibility of the conductive sheet.

When light hits this conductive sheet, the light is reflected in the area of the fine metal wire lattice constituting the first electrode and the second electrode. However, since the reflectance of light is slightly different between the first electrode and the second electrode, there is a problem that the electrode is visually recognized with a slight difference in the amount of reflected light.

The present invention has been made in view of such problems, and an object of the present invention is to provide a conductive sheet and a touch panel having an electrode of a fine metal wire grid, and having improved visibility. To do.

The conductive sheet of one embodiment of the present invention includes a first electrode layer having a plurality of first electrodes extending in a first direction and arranged in a second direction intersecting the first direction, a transparent insulating layer, and a second direction. And a second electrode layer having a plurality of second electrodes extending in the first direction, and a conductive sheet laminated in this order, the first electrode having a branch electrode extending in the width direction, and the first electrode Is composed of a plurality of first lattices made of fine metal wires, the plurality of first lattices is composed of M × N lattice groups, the second electrode has branch electrodes extending in the width direction, and the second electrode is made of fine metal wires The plurality of second lattices are composed of M × N lattice groups, and the first electrode layer and the second electrode layer include a plurality of first lattices and a plurality of second lattices. When viewed from above, the plurality of first lattices and the plurality of second lattices are continuous over the entire surface. M and N are integers and M + N ≦ 9.

Preferably, in the conductive sheet, the first electrode has an aperture ratio of 98 to 99.8% and 40 to 80Ω / sq. The second electrode has an aperture ratio of 98-99.5% and 40-80 Ω / sq. Surface resistivity.

Preferably, the conductive sheet has a plurality of first grids when the first electrode layer and the second electrode layer are viewed from above so that the plurality of first grids and the plurality of second grids do not overlap. And the plurality of second lattices are adjacent to each other by four or less.

Preferably, in the conductive sheet, the proportion of the fine metal wires constituting the first lattice and the second lattice per unit area is 0.2 to 2%.

Preferably, in the conductive sheet, the first grid and the second grid each have one side of 200 to 1000 μm.

Preferably, in the conductive sheet, the first electrode and the second electrode have a width of 4 to 12 mm.

Preferably, in the conductive sheet, the first grid and the second grid each have one side of 240 to 500 μm, and the first electrode and the second electrode have a width of 5 to 7 mm.

Preferably, the conductive sheet is 4 or less in both M and N.

The touch panel according to the second aspect of the present invention has the above conductive sheet.

The conductive sheet according to the three aspects of the present invention includes a first electrode layer having a plurality of first electrodes extending in a first direction and arranged in a second direction intersecting the first direction, a transparent insulating layer, and a second direction. And a second electrode layer having a plurality of second electrodes extending in the first direction, and a conductive sheet laminated in this order, wherein the first electrode has a plurality of first grids of fine metal wires The second electrode has a plurality of second gratings made of fine metal wires, and a first sensing part comprising a second grating of 4 or more and 8 or less and a second sensing part comprising a second grating of 9 or more and 20 or less. The first electrode layer and the second electrode layer are arranged alternately so that the plurality of first lattices and the plurality of second lattices do not overlap with each other when viewed from above. One lattice and the plurality of second lattices are continuously arranged on the entire surface.

The conductive sheet according to the four aspects of the present invention includes a first electrode layer having a plurality of first electrodes extending in a first direction and arranged in a second direction intersecting the first direction, a transparent insulating layer, and a second direction. And a second electrode layer having a plurality of second electrodes extending in the first direction, and a conductive sheet laminated in this order, wherein the first electrode has a plurality of first grids of fine metal wires The second electrode has a plurality of second grids made of thin metal wires, and the first sensing units and the second sensing units having an area 1.5 times larger than the first sensing unit are alternately arranged. The first electrode layer and the second electrode layer are configured such that the plurality of first lattices and the plurality of second lattices do not overlap with each other and when viewed from the top surface, The second lattice is continuously arranged on the entire surface.

Preferably, in the conductive sheet, the first grid and the second grid have the same shape.

Preferably, in the conductive sheet, a sensing unit composed of two or more first grids of the first electrode surrounds the second sensing unit of the second electrode.

Preferably, in the conductive sheet, the second sensing portion has an area of 7 mm ² or less.

According to the present invention, visibility can be improved in a conductive sheet and a touch panel having electrodes formed of a metal thin wire grid.

FIG. 1 is a schematic plan view of a conductive sheet. FIG. 2 is a schematic cross-sectional view of a conductive sheet. FIG. 3 is a plan view of a conductive sheet composed of a diamond pattern. FIG. 4 is a schematic plan view of the first electrode layer. FIG. 5 is a schematic plan view of the second electrode layer. FIG. 6 is a schematic plan view of a conductive sheet in which a first electrode layer and a second electrode layer are overlaid. FIG. 7 is a partially enlarged view of the conductive sheet. FIG. 8 is a partially enlarged view of the conductive sheet. FIG. 9A is a plan view showing an overlapping state of the first electrode and the second electrode. FIG. 9B is a plan view showing an overlapping state of the first electrode and the second electrode. FIG. 9C is a plan view showing an overlapping state of the first electrode and the second electrode. FIG. 10 is an exploded perspective view showing the configuration of the touch panel.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. The present invention will be described by the following preferred embodiments, but can be modified in many ways without departing from the scope of the present invention, and other embodiments than the present embodiment are utilized. be able to. Accordingly, all modifications within the scope of the present invention are included in the claims. In the present specification, “˜” indicating a numerical range is used as a meaning including numerical values described before and after the numerical value as a lower limit value and an upper limit value.

FIG. 1 is a schematic plan view of a conductive sheet 1 for a touch panel, and FIG. 2 is a schematic cross-sectional view of the conductive sheet 1. The conductive sheet 1 extends in a first direction (X direction), has a first electrode layer 10 having a plurality of first electrodes 12 arranged in a second direction (Y direction) intersecting the first direction, a transparent insulating layer 30, And a second electrode layer 40 having a plurality of second electrodes 42 extending in the second direction (Y direction) and arranged in the first direction (X direction).

Each first electrode 12 is electrically connected to the first electrode terminal 14 at one end thereof. Further, each first electrode terminal 14 is electrically connected to the conductive first wiring 16. Each second electrode 42 is electrically connected to the second electrode terminal 44 at one end thereof. Each second electrode terminal 44 is electrically connected to the conductive second wiring 46. The first electrode 12 and the second electrode 42 are each composed of a grid of fine metal wires.

The conductive sheet 1 includes a transparent insulating layer 30 having a first main surface and a second main surface, a first electrode layer 10 disposed on the first main surface of the transparent insulating layer 30, and a transparent insulating layer 30. And a second electrode layer 40 disposed on the second main surface. As shown in FIG. 2, the first electrode 12 and the second electrode 42 are formed with the transparent insulating layer 30 interposed therebetween, but the first electrode 12 and the second electrode 42 are not provided at positions facing each other. On the other hand, when the conductive sheet 1 is viewed from the top, the first electrode 12 and the second electrode 42 are formed of a first main surface and a second main surface of the transparent insulating layer 30 so that the entire surface can be seen as a uniform electrode. Is formed.

The inventor has intensively studied the problem that the electrode is visually recognized due to a slight difference in the amount of reflected light that is generated when light hits the conductive sheet having the above-described configuration.

FIG. 3 is a schematic plan view of a conductive sheet 101 composed of a general so-called diamond pattern. The conductive sheet 101 includes a first electrode 112 and a second electrode 142. The first electrode 112 is composed of a plurality of fine metal grids 126, and the second electrode 142 is composed of a plurality of fine metal grids 156. In order to clarify the first electrode 112 and the second electrode 142, the first electrode 112 is displayed thicker than the second electrode 142. The first electrode 112 has two lattice groups 132 including a plurality of 8 × 8 lattices 126. Similarly, the second electrode 142 includes two lattice groups 162 including a plurality of 8 × 8 lattices 156.

When light hits the conductive sheet 101, the light is reflected in the region of the lattice group 132 and the lattice group 162. Each of the lattice group 132 and the lattice group 162 includes a plurality of 8 × 8 lattices 126 and 156, and the lattice group 132 and the lattice group 162 have a relatively large area. It has been found that even if the difference in reflectance between the grating group 132 and the grating group 162 is small, the electrode is easily visible even if the difference in the amount of reflected light is small when the area is large.

As a result, the first electrode and the second electrode are subdivided as much as possible to reduce the area of the lattice group, and the first electrode and the second electrode are branched so as to extend in the width direction. As a result, it was found that a slight difference in the amount of reflected light is less visible to the human eye, and the present invention was invented.

FIG. 4 is a schematic plan view of the first electrode layer 10 showing an example of the present embodiment. The first electrode layer 10 includes a plurality of first electrodes 12 extending in a first direction (X direction) and arranged in a second direction (Y direction) intersecting the first direction. The first electrode 12 is composed of a plurality of first grids 26 of fine metal wires. The 1st grating | lattice 26 is comprised by enclosing a metal fine wire in the state mutually connected, The opening area | region is formed in the 1st grating | lattice 26. FIG. In the first grating 26 of the present embodiment, an opening region is formed by four sides.

The first electrode 12 extends in the first direction when viewed as a whole. Looking at each first grid 26 constituting the first electrode 12, the first grid 26-1 extends continuously from the first grid 26-1 so as to spread in the width direction of the first electrode 12 along the third direction. Further, starting from the first lattice 26-1, the first grid 26-1 extends continuously in the width direction of the first electrode 12 along the fourth direction. In other words, the first electrode 12 has branch electrodes extending in the third direction and the fourth direction starting from the first lattice 26-1. By having the branch electrode, the sensing area can be widened.

The first grid 26 is continuous means that the two first grids 26 are adjacently arranged sharing one side. However, when the two first gratings 26 are arranged with only the corners without sharing the sides, the first gratings 26 are not in a continuous state.

The first grid 26 continuous along the third direction is conducted by a thin metal wire and extends in the first direction. Similarly, the first grid 26 continuous along the fourth direction is conducted by the fine metal wires and extends in the first direction.

The first grating 26 extending so as to continuously spread in the third direction then extends continuously toward the first grating 26-2 along the fourth direction. In addition, the first grating 26 extending so as to continuously spread in the fourth direction then extends continuously toward the first grating 26-2 along the third direction. Thereby, the repeating pattern of the 1st electrode 12 enclosed with the circle mark is comprised. In this embodiment, one repeating pattern has a hexagonal shape, and three repeating patterns extend in the first direction.

Adjacent repeating patterns are electrically connected by the first grating 26-2 and the first grating 26-3, and by the first grating 26-4 and the first grating 26-5. However, the corners of the first grating 26-2 and the first grating 26-3 are connected to each other, and the corners of the first grating 26-4 and the first grating 26-5 are connected to each other. This does not correspond to the continuous first lattice 26.

As shown in FIG. 4, the first electrode 12 is composed of a lattice group of a plurality of M × N first lattices 26. Here, the lattice group composed of a plurality of M × N first lattices 26 means a state in which a plurality of first lattices 26 sharing a side are arranged in a matrix of M × N. At this time, the plurality of first lattices 26 are arranged so that M and N are integers and M + N ≦ 9. This is to prevent the area of the lattice group from becoming too large when the plurality of first lattices 26 are arranged in M × N. Visibility can be improved by setting the grid group of the first grid 12 of the first electrode 12 to M + N ≦ 9. Further, both M and N are preferably 4 or less.

For M and N, for example, when M = 7 and N = 2, M + N = 9 and satisfies M + N ≦ 9. M × N = 7 × 2 and the lattice group includes 14 first lattices 26. Visibility can be improved because the area of the lattice group does not become too large.

On the other hand, when M = 5 and N = 5, M + N = 10 and M + N ≦ 9 is not satisfied. Since the lattice group constituted by the first lattice 26 has a large area as a whole, it is not preferable from the viewpoint of visibility.

In FIG. 4, along the third direction, the first lattice 26 continuously forms a lattice group with M × N = 1 × 5. Further, along the fourth direction, the first lattice 26 continuously forms a lattice group with M × N = 1 × 5. In FIG. 4, these are the lattice groups having the maximum area. Since the lattice group in FIG. 4 satisfies M + N ≦ 9, visibility can be improved. Since the first electrode 12 has an elongated shape, M × N = 2 × 7 is preferable, M × N = 2 × 5 is more preferable, and M × N = 1 × 5 is more preferable.

Further, from another viewpoint, in the first electrode 12, the first grating 26 is arranged so that when the first grating 26 continues seven or more in the third direction, it does not continue three or more in the fourth direction. That is, the first lattice 26 is not arranged in a matrix of 7 × 3 or more and restricts the lattice group from occupying a large area. It is important to satisfy M + N ≦ 9.

In addition, regarding the direction, the direction in which the first electrode 12 extends and the direction in which the first electrode 12 extends are defined as the first direction and the second direction, respectively, and the direction in which the continuous first lattice 26 extends is defined as the third direction and the fourth direction. The direction in which the continuous first lattice 26 extends is not limited to the third direction and the fourth direction, and many directions such as a fifth direction can be adopted.

The first direction and the third direction, the second direction and the fourth direction may be the same, or each may have a certain inclination angle. In FIG. 4 of the present embodiment, the first direction and the third direction, and the second direction and the fourth direction have a constant inclination angle.

Generally, the first direction and the second direction indicate the vertical and horizontal directions of the screen display in which the conductive sheet 1 is used, but are not particularly specified here. It is preferable that the direction of the continuous first lattice 26 and the direction of the first electrode 12 have an angle at which moiré is unlikely to occur. The direction of the first electrode 12 substantially coincides with the vertical and horizontal directions of the screen, but may not be completely the same.

The fine metal wire constituting the first electrode 12 has a line width of 30 μm or less, and the fine metal wire is made of a metal material such as gold, silver or copper, or a conductive material such as a metal oxide.

Regarding the line width of the fine metal wire, it is 30 μm or less, preferably 15 μm or less, more preferably 10 μm or less, more preferably 9 μm or less, more preferably 7 μm or less, and preferably 0.5 μm or more, preferably 1 μm or more.

The first electrode 12 includes a plurality of first lattices 26 made of intersecting fine metal wires. The first lattice 26 includes an opening region surrounded by fine metal wires. The first grating 26 preferably has one side of 200 to 1000 μm. More preferably, the first grating 26 has one side of 240 to 500 μm. By setting it as this range, it is excellent in light transmittance and it is hard to visually recognize a thin line.

The first electrode 12 has a width W1 of 4 to 12 mm or less, preferably a width W1 of 5 to 7 mm. By setting this range, the electrode width can be adapted to finger touch.

In particular, when one side of the first grating 26 is 240 to 500 μm and the width of the first electrode 12 is 5 to 7 mm, the effects of low resistance and improved visibility can be achieved.

The first electrode 12 preferably has an aperture ratio of 98 to 99.8% from the viewpoint of visible light transmittance. The aperture ratio corresponds to the ratio of the area of the translucent portion not occupied by the fine metal wires of the first electrode 12 in the predetermined region to the entire area. In other words, it corresponds to the ratio of the fine metal wire per unit area subtracted from 1, expressed as a percentage. Therefore, the ratio of the fine metal wires per unit area is 0.2 to 2%.

The surface resistivity of the first electrode 12 is 10 to 120 Ω / sq. , Especially 40-80 Ω / sq. The range is as follows. There is a trade-off relationship between the aperture ratio and the surface resistivity. For example, in the case of a display for electronic paper to which the conductive sheet 1 of the present embodiment is applied, priority is given to increasing the first lattice 26 to increase the aperture ratio, and in the case of a display for a personal computer monitor or tablet PC, the surface Prioritize lowering resistivity. Therefore, the aperture ratio and the surface resistivity are determined in consideration of the applied display.

The surface resistivity can be obtained with a surface resistivity meter of MCP-T610 manufactured by Mitsubishi Chemical Corporation. At the time of measurement, a full-face mesh sample (without a cut portion or the like) having the same line width, lattice size, and aperture ratio as that of the electrode is prepared and measured.

In the conductive sheet 1 described above, the first lattice 26 has a rectangular shape. However, other polygonal shapes may be used. Further, the shape of one side may be a curved shape or a circular arc shape in addition to a linear shape. In the case of an arc shape, for example, two opposing sides may be outwardly convex arc shapes, and the other two opposing sides may be inwardly convex arc shapes. The shape of each side may be a wavy shape in which an outwardly convex arc and an inwardly convex arc are continuous. Of course, the shape of each side may be a sine curve.

FIG. 5 is a schematic plan view of the second electrode layer 40 showing an example of the present embodiment. The second electrode layer 40 includes a plurality of second electrodes 42 extending in the second direction (Y direction) and arranged in a first direction (X direction) intersecting the second direction. The second electrode 42 is composed of a plurality of second grids 56 of fine metal wires. The 2nd grating | lattice 56 is comprised by enclosing a metal fine wire in the state mutually connected, The opening area | region is formed in the 2nd grating | lattice 56. FIG. In the second grating 56 of the present embodiment, an opening region is formed by four sides.

The second electrode 42 extends in the second direction as a whole. In FIG. 5, the second grating 56 constitutes a plurality of grating groups arranged in a matrix continuously in the third direction and the fourth direction. Specifically, the second electrode 42 includes a lattice group having a small area indicated by a circled area A and a lattice group having a large area indicated by a circled area B. Small lattice areas and large lattice groups are alternately arranged along the second direction. The lattice group having a small area and the lattice group having a large area are electrically connected by a thin metal wire. A lattice group having a small area constitutes a first sensing unit, and a lattice group having a large area constitutes a second sensing unit.

The first sensing unit is M + N ≦ 9, and is composed of a lattice group of seven second lattices 56. The first sensing unit in the present embodiment includes a lattice group composed of the second lattice 56 of M × N = 2 × 2. It is preferable that the first sensing unit is configured by a number of second gratings 56 that is 4 or more and 8 or less.

Further, from another viewpoint, in the second electrode 42, when the second grating 56 is continuous seven or more in the third direction, the second grating 56 is arranged so as not to be continuous five or more in the fourth direction. That is, the second lattice 56 is not arranged in a matrix of 7 × 3 or more and restricts the lattice group from occupying a large area. It is important to satisfy M + N ≦ 9.

The second sensing unit is M + N ≦ 9, and is composed of a lattice group of 14 second lattices 56. The second sensing unit in the present embodiment includes a lattice group composed of the second lattice 56 of M × N = 3 × 3. It is preferable that the second sensing unit is composed of 9 or more and 20 or less second gratings 56.

Regarding the size of the second sensing unit and the first sensing unit, the second sensing unit preferably has an area of 1.5 times or more that of the first sensing unit. Further, the area of the second sensing part is preferably 7 mm ² or less. The area can be obtained by (area of second grating 56) × (number of second gratings 56).

The second electrode 42 includes two branch electrodes extending in the first direction from the first sensing unit. By having the branch electrode, the sensing area can be widened. The branch electrode is provided in the first sensing unit that is repeatedly arranged.

The same thing as the first electrode 12 can be applied to the line width and material of the fine metal wire constituting the second electrode 42. The length of one side constituting the second grating 56 is 200 to 1000 μm, preferably 240 to 500 μm, like the first grating 26.

The second electrode 42 has a width W2 of 4 to 12 mm, preferably a width W2 of 5 to 7 mm or less. Similarly to the first electrode 12, it is preferable that one side of the second grating 56 is 240 to 500 μm and the width of the second electrode 42 is 5 to 7 mm.

The aperture ratio of the second electrode 42 is in the range of 98 to 99.8%. The proportion of the second electrode 42 per unit area of the fine metal wire is 0.2 to 2%. The surface resistivity of the second electrode 42 is 40 to 80Ω / sq. Range. In the above-described conductive sheet 1, the second grid 56 has a rectangular shape, but is not limited thereto, and can have the same shape as the first grid 26.

FIG. 6 is a plan view of the conductive sheet 1 in which the first electrode layer 10 and the second electrode layer 40 are disposed to face each other. The first electrode 12 and the second electrode 42 are disposed so as to be orthogonal to each other, and constitute the conductive sheet 1.

The first electrode layer 10 and the second electrode layer 40 are arranged to face each other, but the first electrode 12 and the second electrode 42 are not opposed to each other. It arrange | positions so that it may not overlap with the 2nd grating | lattice 56 of 42. FIG. That is, the region where the first electrode 12 of the first electrode layer 10 is formed overlaps the region where the second electrode 42 of the second electrode layer 40 is not formed, and the first electrode 12 of the first electrode layer 10 is The region where the second electrode 42 of the second electrode layer 40 is formed overlaps the region where it is not formed. In FIG. 6, the second electrode 42 is indicated by a thicker line than the first electrode 12 so that the first electrode 12 and the second electrode 42 can be easily recognized.

By arranging the first electrode layer 10 and the second electrode layer 40 to face each other, as shown in FIG. 6, a plurality of first gratings 26 and a plurality of second gratings 56 are continuously arranged on the entire surface. . The arrangement of the plurality of first gratings 26 and the plurality of second gratings 56 continuously on the entire surface means a state in which the first grating 26 and the second grating 56 are continuous at a glance. Since the first grid 26 is formed on the first electrode layer 10 and the second grid 56 is formed on the second electrode layer 40, the first grid 26 and the second grid 56 are not physically connected. . When the first electrode layer 10 and the second electrode layer 40 are overlapped and seen through, the first electrode layer 10 and the second electrode layer 40 may be continuous at first glance. Also. At first glance, the metal lines of the first grating 26 and the metal lines of the second grating 56 are not exactly linearly continuous, but it looks like that to the human naked eye, and the magnifying lens It also includes a state where there is a disconnection part or the line is slightly shifted when viewed through.

FIG. 7 is a partially enlarged view of the conductive sheet 1 shown in FIG. The first electrode 12 and the second electrode 42 are disposed so as not to overlap each other when viewed from above. In the top view, the area C includes four first gratings 26-1 to 26-4 that constitute a part of the first electrode 12. The first gratings 26-1 to 26-4 are arranged adjacent to the metal thin wires or the second gratings 56-1 to 56-2 constituting the second electrode 42 in the area C. In the present embodiment, the first grating 26 and the second grating 56 are arranged adjacent to each other with four or less.

Thus, by disposing the first grid 26 and the second grid 56, the capacitance Cm can be reduced. When the capacitance Cm decreases, the ratio ΔCm / Cm of the capacitance ΔCm that changes when touched with a finger increases, and the presence / absence of the finger is easily detected. Even when the overlapping portion of the first grating 26 and the second grating 56 is reduced, the first electrode 12 has a hexagonal repeating pattern in order to increase the sensing area, and the second electrode 42 Includes a branch electrode extending in the width direction of the second electrode 42.

FIG. 8 is a partially enlarged view of the conductive sheet 1 shown in FIG. Unlike the conductive sheet of FIG. 7, the conductive sheet of FIG. 8 has a dummy pattern. In FIG. 6, when viewed from the top, there is a gap between the first electrode 12 and the second electrode 42 where no fine metal wire is formed. In this gap, since it does not reflect even if it hits, it is recognized as a pattern and affects visibility.

Therefore, in FIG. 8, dummy patterns 29 and 59 are formed by metal fine wires in the gap between the first electrode 12 and the second electrode 42. The dummy pattern 29 is formed on the first electrode layer 10, and the dummy pattern 59 is formed on the second electrode layer 40. Since the dummy patterns 29 and 59 are formed in the gap between the first electrode 12 and the second electrode 42, they may be formed on either the first electrode layer 10 or the second electrode layer 40. As long as the first electrode 12, the second electrode 42, and the dummy patterns 29 and 59 are viewed from the top, the first grating 26 and the second grating 56 may be in a continuous state at a glance.

When the first electrode layer 10 and the second electrode layer 40 are arranged to face each other, there may be a shift in the position of the fine metal wire between the first grating 26 and the second grating 56 due to a process error. Therefore, by design, when the first electrode layer 10 and the second electrode layer 40 are overlapped, a continuous lattice having a uniform interval and a uniform shape as a whole is formed. However, the phenomenon of FIGS. 9A to 9C occurs. In FIG. 9A, the first electrode 12 and the second electrode 42 are not displaced and match as designed. In FIG. 9B, the first electrode 12 and the second electrode 42 are not arranged in a straight line. On the other hand, it is not recognized with the naked eye. In FIG. 9C, the first electrode 12 and the second electrode 42 are partially overlapped, and a gap (discontinuity) is partially generated. A portion where the first electrode 12 and the second electrode 42 overlap is a factor that deteriorates visibility because the fine metal wire looks thick.

In the above situation, the following is effective. First, it is important to design such that the deviation occurs as shown in FIG. 9B, and secondly, to design the metal fine wire to be short, so that the first electrode 12 and the second electrode 42 do not overlap.

Next, a touch panel 100 using the above-described conductive sheet 1 will be described with reference to FIG. The touch panel 100 includes a sensor body 102 and a control circuit (not shown) (configured by an IC (Integrated Circuit) circuit or the like). The sensor body 102 includes the conductive sheet 1 and a protective layer 106 laminated thereon. The conductive sheet 1 and the protective layer 106 are arranged on a display panel 110 in a display device 108 such as a liquid crystal display.

Next, a method for manufacturing the conductive sheet 1 will be described.

When the conductive sheet 1 is produced, for example, by exposing a photosensitive material having an emulsion layer containing a photosensitive silver halide salt on the first main surface of the transparent transparent insulating layer 30, and performing a development process, The first electrode layer 10 may be formed by forming a metal silver part (metal thin wire) and a light transmissive part (opening region) in the exposed part and the unexposed part, respectively. In addition, you may make it carry | support a conductive metal to a metal silver part by giving a physical development and / or a plating process to a metal silver part further.

Alternatively, a photoresist film on the copper foil formed on the first main surface of the transparent transparent insulating layer 30 is exposed and developed to form a resist pattern, and the copper foil exposed from the resist pattern is etched. Thus, the first electrode layer 10 may be formed.

Alternatively, the first electrode layer 10 may be formed by printing a paste containing metal fine particles on the first main surface of the transparent transparent insulating layer 30 and performing metal plating on the paste.

The first electrode layer 10 may be printed on the first main surface of the transparent transparent insulating layer 30 by screen printing or gravure printing. Alternatively, the first electrode layer 10 may be formed on the first main surface of the transparent transparent insulating layer 30 by inkjet.

Regarding the second electrode layer 40, the second electrode layer 40 can be formed on the second main surface of the transparent insulating layer 30 by the same manufacturing method of the first electrode layer 10.

By forming a photosensitive layer to be plated on the transparent transparent insulating layer 30 using a pretreatment material for plating, exposing and developing, and then performing plating treatment, the exposed portion and the unexposed portion are respectively subjected to a metal portion and a light transmissive property. The first electrode layer 10 and the second electrode layer 40 may be formed by forming a portion. Further, a conductive metal may be supported on the metal part by further performing physical development and / or plating treatment on the metal part. More specific contents are disclosed in JP2003-213437, JP2006-64923, JP2006-58797, JP2006-135271, and the like.

As shown in FIG. 2, when the first electrode layer 10 is formed on the first main surface of the transparent insulating layer 30 and the second electrode layer 40 is formed on the second main surface of the transparent insulating layer 30, In accordance with the manufacturing method, the first electrode surface 10 and the second electrode layer 40 having a desired pattern are obtained by adopting a method in which the first main surface is first exposed and then the second main surface is exposed. It may not be possible.

Therefore, the following production method can be preferably employed.

That is, the photosensitive silver halide emulsion layer formed on both surfaces of the transparent insulating layer 30 is collectively exposed to form the first electrode layer 10 on one main surface of the transparent insulating layer 30. The second electrode layer 40 is formed on the other main surface.

A specific example of this manufacturing method will be described.

First, make a long photosensitive material. The photosensitive material includes a transparent insulating layer 30, a photosensitive silver halide emulsion layer (hereinafter referred to as a first photosensitive layer) formed on the first main surface of the transparent insulating layer 30, and the other main layer of the transparent insulating layer 30. And a photosensitive silver halide emulsion layer (hereinafter referred to as a second photosensitive layer) formed on the surface.

Next, the photosensitive material is exposed. In this exposure process, the first photosensitive layer is irradiated with light toward the transparent insulating layer 30 to expose the first photosensitive layer along the first exposure pattern, and the second photosensitive layer is exposed. Then, a second exposure process is performed in which light is irradiated toward the transparent insulating layer 30 to expose the second photosensitive layer along the second exposure pattern (double-sided simultaneous exposure).

For example, while conveying a long photosensitive material in one direction, the first photosensitive layer is irradiated with the first light (parallel light) through the first photomask, and the second photosensitive layer is irradiated with the second light (parallel light). ) Through the second photomask. The first light is obtained by converting the light emitted from the first light source into parallel light by the first collimator lens in the middle, and the second light is obtained by converting the light emitted from the second light source in the middle of the first light. It is obtained by being converted into parallel light by a two-collimator lens.

In the above description, the case where two light sources (the first light source and the second light source) are used is shown, but the light emitted from one light source is divided through the optical system, and the first light and the second light are divided. The first photosensitive layer and the second photosensitive layer may be irradiated as light.

Next, the exposed photosensitive material is developed to produce a conductive sheet 1 for a touch panel. The conductive sheet 1 for a touch panel includes a transparent insulating layer 30, the first electrode layer 10 along the first exposure pattern formed on the first main surface of the transparent insulating layer 30, and the other main electrode of the transparent insulating layer 30. And a second electrode layer 40 along the second exposure pattern formed on the surface. In addition, since the exposure time and development time of the first photosensitive layer and the second photosensitive layer vary depending on the types of the first light source and the second light source, the type of the developer, and the like, the preferable numerical range should be determined unambiguously. However, the exposure time and the development time are adjusted so that the development rate becomes 100%.

In the manufacturing method according to the present embodiment, the first exposure process includes, for example, arranging a first photomask on the first photosensitive layer in close contact with the first light source arranged opposite to the first photomask. The first photosensitive layer is exposed by irradiating the first light toward one photomask. The first photomask is composed of a glass substrate formed of transparent soda glass and a mask pattern (first exposure pattern) formed on the glass substrate. Accordingly, the first exposure process exposes a portion of the first photosensitive layer along the first exposure pattern formed on the first photomask. A gap of about 2 to 10 μm may be provided between the first photosensitive layer and the first photomask.

Similarly, in the second exposure process, for example, a second photomask is disposed in close contact with the second photosensitive layer, and the second light source disposed opposite to the second photomask is secondly directed toward the second photomask. The second photosensitive layer is exposed by irradiating light. Similar to the first photomask, the second photomask is composed of a glass substrate made of transparent soda glass and a mask pattern (second exposure pattern) formed on the glass substrate. Therefore, the second exposure process exposes a portion of the second photosensitive layer along the second exposure pattern formed on the second photomask. In this case, a gap of about 2 to 10 μm may be provided between the second photosensitive layer and the second photomask.

In the first exposure process and the second exposure process, the emission timing of the first light from the first light source and the emission timing of the second light from the second light source may be simultaneous or different. At the same time, the first photosensitive layer and the second photosensitive layer can be exposed simultaneously by one exposure process, and the processing time can be shortened. By the way, when both the first photosensitive layer and the second photosensitive layer are not spectrally sensitized, when the photosensitive material is exposed from both sides, the exposure from one side affects the image formation on the other side (back side). Become.

That is, the first light from the first light source that has reached the first photosensitive layer is scattered by the silver halide grains in the first photosensitive layer, passes through the transparent insulating layer 30 as scattered light, and a part thereof is the first light. Reach up to 2 photosensitive layers. Then, the boundary portion between the second photosensitive layer and the transparent insulating layer 30 is exposed over a wide range, and a latent image is formed. For this reason, in the second photosensitive layer, exposure with the second light from the second light source and exposure with the first light from the first light source are performed, and when the conductive sheet 1 for touch panel is formed in the subsequent development processing. In addition to the conductive pattern (second electrode layer 40) by the second exposure pattern, a thin conductive layer by the first light from the first light source is formed between the conductive patterns, and a desired pattern (along the second exposure pattern) Pattern) cannot be obtained. The same applies to the first photosensitive layer.

In order to avoid this, as a result of earnest studies, by setting the thickness of the first photosensitive layer and the second photosensitive layer to a specific range, or by specifying the coating silver amount of the first photosensitive layer and the second photosensitive layer, It has been found that the silver halide itself absorbs light and can limit light transmission to the back side. The thickness of the first photosensitive layer and the second photosensitive layer can be set to 1 μm or more and 4 μm or less. The upper limit is preferably 2.5 μm. Further, the coated silver amount of the first photosensitive layer and the second photosensitive layer was regulated to 5 to 20 g / m ² .

In the above-described double-sided contact exposure method, image defects due to exposure inhibition due to dust adhering to the sheet surface becomes a problem. It is known to apply a conductive material to the sheet as a dust prevention, but metal oxides remain after processing, impairing the transparency of the final product, and conductive polymers are storable. There is a problem. As a result of intensive studies, it was found that the silver halide with a reduced amount of binder provided the necessary conductivity for antistatic, and the silver / binder volume ratio of the first photosensitive layer and the second photosensitive layer was defined. That is, the silver / binder volume ratio of the first photosensitive layer and the second photosensitive layer is 1/1 or more, and preferably 2/1 or more.

As described above, the first light from the first light source reaching the first photosensitive layer is set and defined by setting the thickness of the first photosensitive layer and the second photosensitive layer, the coating silver amount, and the volume ratio of silver / binder. Does not reach the second photosensitive layer. Similarly, the second light from the second light source that has reached the second photosensitive layer does not reach the first photosensitive layer. As a result, when the conductive sheet 1 is formed in the subsequent development processing, only the first electrode layer 10 based on the first exposure pattern is formed on the first main surface of the transparent insulating layer 30, and the first of the transparent insulating layer 30 Only the second electrode layer 40 based on the second exposure pattern is formed on the main surface of 2, and a desired pattern can be obtained.

Thus, in the manufacturing method using the above-described double-sided batch exposure, it is possible to obtain the first photosensitive layer and the second photosensitive layer that have both conductivity and suitability for double-sided exposure. In addition, the same pattern or different patterns can be arbitrarily formed on both surfaces of the transparent insulating layer 30 by the exposure process on one transparent insulating layer 30, thereby easily forming the electrodes of the touch panel. At the same time, the touch panel can be made thinner (low profile).

Next, in the conductive sheet 1 according to the present embodiment, a method using a silver halide photographic light-sensitive material that is a particularly preferable aspect will be mainly described.

The manufacturing method of the conductive sheet 1 according to the present embodiment includes the following three forms depending on the photosensitive material and the form of development processing.

(1) A mode in which a photosensitive silver halide black-and-white photosensitive material not containing physical development nuclei is chemically developed or thermally developed to form a metallic silver portion on the photosensitive material.

(2) A mode 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 overlapped and transferred to develop a non-photosensitive image-receiving sheet. Form formed on top.

The above aspect (1) is an integrated black-and-white development type, and a light-transmitting conductive film such as a light-transmitting conductive film is formed on the photosensitive material. The resulting developed silver is chemically developed silver or heat developed silver, and is highly active in the subsequent plating or physical development process in that it is a filament with a high specific surface.

In the above aspect (2), the light-transmitting conductive film such as a light-transmitting conductive film is formed on the photosensitive material by dissolving silver halide grains close to the physical development nucleus and depositing on the development nucleus in the exposed portion. A characteristic film is formed. This is also an integrated black-and-white development type. Although the development action is precipitation on the physical development nuclei, it is highly active, but developed silver is a sphere 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 conductive film or the like is formed on the image receiving sheet. A conductive film is formed. This is a so-called 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). .

Here, the configuration of the conductive sheet 1 according to the present embodiment will be described in detail below.

[Transparent insulating layer 30]
Examples of the transparent insulating layer 30 include a plastic film, a plastic plate, and a glass plate. Examples of the raw material for the plastic film and plastic plate include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN); polyethylene (PE), polypropylene (PP), polystyrene, ethylene vinyl acetate (EVA) / cyclo Polyolefins such as olefin polymer (COP) / cycloolefin polymer (COC); vinyl resins; others, polycarbonate (PC), polyamide, polyimide, acrylic resin, triacetyl cellulose (TAC), and the like can be used. In particular, polyethylene terephthalate (PET) is preferable from the viewpoints of light transmittance and processability.

[Silver salt emulsion layer]
The silver salt emulsion layer to be the first electrode layer 10 and the second electrode layer 40 of the conductive sheet 1 contains additives such as a solvent and a dye in addition to the silver salt and the binder.

Examples of the silver salt used in the present embodiment include inorganic silver salts such as silver halide and organic silver salts such as silver acetate. In the present embodiment, it is preferable to use silver halide having excellent characteristics as an optical sensor.

Silver coating amount of silver salt emulsion layer (coating amount of silver salt) is preferably 1 ~ 30g / ^{m 2} in terms of silver, more preferably 1 ~ 25g / ^{m 2,} more preferably 5 ~ 20g / ^{m 2} . By setting the amount of coated silver within the above range, a desired surface resistivity can be obtained when the conductive sheet 1 for a touch panel is used.

Examples of the binder used in this embodiment include gelatin, polyvinyl alcohol (PVA), polyvinyl pyrrolidone (PVP), starch and other polysaccharides, cellulose and derivatives thereof, polyethylene oxide, polyvinyl amine, chitosan, polylysine, and polyacryl. Examples include acid, polyalginic acid, polyhyaluronic acid, carboxycellulose and the like. These have neutral, anionic, and cationic properties depending on the ionicity of the functional group.

The content of the binder contained in the silver salt emulsion layer is not particularly limited, and can be appropriately determined as long as dispersibility and adhesion can be exhibited. The binder content in the silver salt emulsion layer is preferably ¼ or more, more preferably ½ or more in terms of the silver / binder volume ratio. The silver / binder volume ratio is preferably 100/1 or less, more preferably 50/1 or less, further preferably 10/1 or less, and particularly preferably 6/1 or less. The silver / binder volume ratio is more preferably 1/1 to 4/1. Most preferably, it is 1/1 to 3/1. By setting the silver / binder volume ratio in the silver salt emulsion layer within this range, it is possible to obtain a conductive sheet for a touch panel having a uniform surface resistivity by suppressing variation in resistance value even when the amount of coated silver is adjusted. it can. The silver / binder volume ratio is converted from the amount of silver halide / binder amount (weight ratio) of the raw material to the amount of silver / binder amount (weight ratio), and the amount of silver / binder amount (weight ratio) is further converted to the amount of silver. / It can obtain | require by converting into binder amount (volume ratio).

<Solvent>
The solvent used for forming the silver salt emulsion layer 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 silver salt emulsion layer of the present embodiment is in the range of 30 to 90% by mass with respect to the total mass of silver salt and binder contained in the silver salt emulsion layer, and 50 to 80%. It is preferably in the range of mass%.

<Other additives>
The various additives used in the present embodiment are not particularly limited, and known ones can be preferably used.

[Other layer structure]
A protective layer (not shown) may be provided on the silver salt emulsion layer. In the present embodiment, the “protective layer” means a layer made of a binder such as gelatin or a high molecular polymer, and is formed on a silver salt emulsion layer having photosensitivity in order to exhibit an effect of preventing scratches and improving mechanical properties. It is formed. The thickness is preferably 0.5 μm or less. The coating method and forming method of the protective layer are not particularly limited, and a known coating method and forming method can be appropriately selected. An undercoat layer, for example, can be provided below the silver salt emulsion layer.

Next, each step of the method for producing the conductive sheet 1 will be described.

[exposure]
In the present embodiment, the case where the first electrode layer 10 and the second electrode layer 40 are applied by a printing method is included, but the first electrode layer 10 and the second electrode layer 40 are formed by exposure and development, etc., except for the printing method. To do. That is, exposure is performed on a photosensitive material having a silver salt-containing layer provided on the transparent insulating layer 30 or a photosensitive material coated with a photopolymer for photolithography. The exposure can be performed using electromagnetic waves. 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.

Regarding the exposure method, a method through a glass mask or a pattern exposure method by laser drawing is preferable.

[Development processing]
In this embodiment, after the emulsion layer is exposed, development processing is further 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 development process in the present embodiment can include a fixing process performed for the purpose of removing and stabilizing the silver salt in the unexposed part. 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 light-sensitive material that has been subjected to development and fixing processing is preferably subjected to a film hardening process, a water washing process, and a stabilization process.

The mass of the metallic silver contained in the exposed part after the development treatment is preferably 50% by mass or more, and 80% by mass or more, based on the mass of silver contained in the exposed part before exposure. More preferably. 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 the aforementioned doping of rhodium ions and iridium ions.

The conductive sheet is obtained through the above steps, but the surface resistivity of the obtained conductive sheet is 40-80 Ω / sq. The following is preferred.

By adjusting the surface resistivity within such a range, position detection can be performed even with a large touch panel having an area of 10 cm × 10 cm or more. Further, the conductive sheet after the development treatment may be further subjected to a calendar treatment, and can be adjusted to a desired surface resistivity by the calendar treatment.

(Hardening after development)
It is preferable to perform a film hardening process by immersing the film in a hardener after the silver salt emulsion layer is developed. Examples of the hardener include dialdehydes such as glutaraldehyde, adipaldehyde, 2,3-dihydroxy-1,4-dioxane, and inorganic compounds such as boric acid and chromium alum / potassium alum. No. 141279 can be mentioned.

[Physical development and plating]
In the present embodiment, for the purpose of improving the conductivity of the metallic silver portion formed by the exposure and development processing, physical development and / or plating treatment for supporting the conductive metal particles on the metallic silver portion is performed. May be. In the present invention, the conductive metal particles may be supported on the metallic silver portion by only one of physical development and plating treatment, or the conductive metal particles are supported on the metallic silver portion by combining physical development and plating treatment. May be. In addition, the thing which performed the physical development and / or the plating process to the metal silver part is called "conductive metal part".

[Oxidation treatment]
In the present embodiment, it is preferable to subject the metallic silver portion after the development treatment and the conductive metal portion formed by physical development and / or plating treatment to 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.

[Light transmissive part]
The “light transmissive part” in the present embodiment means a part having translucency other than the first electrode layer 10 and the second electrode layer 40 in the conductive sheet 1. As described above, the transmittance in the light transmissive portion is 90% or more, preferably the transmittance indicated by the minimum value of the transmittance in the wavelength region of 380 to 780 nm excluding the contribution of light absorption and reflection of the transparent insulating layer 30. Is 95% or more, more preferably 97% or more, even more preferably 98% or more, and most preferably 99% or more.

[Conductive sheet 1]
The film thickness of the transparent insulating layer 30 in the conductive sheet 1 according to the present embodiment is preferably 5 to 350 μm, and more preferably 30 to 150 μm. If it is in the range of 5 to 350 μm, a desired visible light transmittance can be obtained, and handling is easy.

The thickness of the metallic silver portion provided on the transparent insulating layer 30 can be appropriately determined according to the coating thickness of the silver salt-containing layer coating applied on the transparent insulating layer 30. The thickness of the metallic silver part can be selected from 1.0 × 10 ⁻⁵ to 0.2 mm, preferably 30 μm or less, more preferably 20 μm or less, and 0.01 to 9 μm. More preferably, the thickness is 0.05 to 5 μm. Moreover, it is preferable that a metal silver part is pattern shape. The metallic silver part may be a single layer or a multilayer structure of two or more layers. When the metallic silver portion is patterned and has a multilayer structure of two or more layers, different color sensitivities can be imparted so as to be sensitive to different wavelengths. Thereby, when the exposure wavelength is changed and exposed, a different pattern can be formed in each layer.

The thickness of the conductive metal part is preferably as the thickness of the touch panel is thinner because the viewing angle of the display panel is wider, and a thin film is also required for improving the visibility. From such a viewpoint, the thickness of the layer made of the conductive metal supported on the conductive metal portion is desirably less than 9 μm, less than 5 μm, less than 3 μm, and 0.1 μm or more.

In the present embodiment, the thickness of the layer made of conductive metal particles is formed by controlling the coating thickness of the silver salt-containing layer described above to form a metallic silver portion having a desired thickness, and further by physical development and / or plating treatment. Therefore, even the conductive sheet 1 having a thickness of less than 5 μm, preferably less than 3 μm can be easily formed.

In addition, in the manufacturing method of the electrically conductive sheet which concerns on this Embodiment, processes, such as plating, do not necessarily need to be performed. This is because in the method for manufacturing the conductive sheet 1 according to the present embodiment, a desired surface resistivity can be obtained by adjusting the amount of silver applied to the silver salt emulsion layer and the silver / binder volume ratio.

The conductive sheet and the touch panel according to the present invention are not limited to the above-described embodiments, and various configurations can be adopted without departing from the gist of the present invention. Further, it can be used in appropriate combination with the techniques disclosed in JP2011-113149, JP2011-129501, JP2011-129112, JP2011-134311, JP2011-175628, and the like.

Hereinafter, the present invention will be described in more detail 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.

<Formation of conductive pattern>
(Silver halide photosensitive material)
An emulsion containing 10.0 g of gelatin per 150 g of Ag in an aqueous medium and containing silver iodobromochloride grains having an average equivalent sphere diameter of 0.1 μm (I = 0.2 mol%, Br = 40 mol%) was prepared. .

In this emulsion, K ₃ Rh ₂ Br ₉ and K ₂ IrCl ₆ were added so as to have a concentration of 10 ⁻⁷ (mol / mol silver), and silver bromide grains were doped with Rh ions and Ir ions. . After adding Na ₂ PdCl ₄ to this emulsion and further performing gold-sulfur sensitization using chloroauric acid and sodium thiosulfate, together with the gelatin hardener, the coating amount of silver was 10 g / m ^2. It apply | coated on the base | substrate 30 (here, both polyethylene terephthalate (PET)). At this time, the volume ratio of Ag / gelatin was 2/1.

A 30 cm wide PET support was applied for 20 m in a width of 25 cm, and both ends were cut off by 3 cm so as to leave a central portion of the coating, and a roll-shaped silver halide photosensitive material was obtained.

(exposure)
With respect to the exposure pattern, a plurality of photomasks having different numbers of lattices, aperture ratios, line widths, and the like were prepared, and exposure was performed using parallel light using a high-pressure mercury lamp as a light source via these photomasks.

(Development processing)
・ Developer 1L formulation Hydroquinone 20 g
Sodium sulfite 50 g
Potassium carbonate 40 g
Ethylenediamine tetraacetic acid 2 g
Potassium bromide 3 g
Polyethylene glycol 2000 1 g
Potassium hydroxide 4 g
Adjust pH to 10.3 ・ Prescription fixer 1L ammonium thiosulfate solution (75%) 300 ml
Ammonium sulfite monohydrate 25 g
1,3-diaminopropane tetraacetic acid 8 g
Acetic acid 5 g
Ammonia water (27%) 1 g
Adjustment to pH 6.2 Photosensitive material exposed using the above processing agent is processed using an automatic processor FG-710PTS manufactured by Fujifilm Corporation: Development 35 ° C. for 30 seconds, Fixing 34 ° C. 23 seconds, Washing water (5 L / Min) for 20 seconds.

<Tests 1 to 12>
Using multiple photomasks, changing the conditions of the lattice group size (M × N), aperture ratio, surface resistivity, metal wire occupancy, electrode width, and length of one side of the lattice Thus, conductive sheets of Tests 1 to 12 were produced. For Tests 1 to 12, visibility was evaluated. The evaluation of visibility was judged by visual observation, and A was given when the lattice group was almost invisible, B was given when the lattice group was slightly visible but C was given when the lattice group was clearly visible. Table 1 shows the conditions and evaluation results of tests 1 to 12.

From Table 1, Tests 1 to 10 satisfying M + N ≦ 9 obtained an evaluation of B or more for visibility. In tests 1 to 10, the evaluation of A was made especially when the length of one side of the lattice was 500 μm or less. On the other hand, tests 11 and 12 with M + N> 9 were C evaluations even when the length of one side of the grating was 500 μm.

DESCRIPTION OF SYMBOLS 1 ... Conductive sheet, 10 ... 1st electrode layer, 12 ... 1st electrode, 14 ... 1st electrode terminal, 16 ... 1st wiring, 26 ... 1st grating | lattice, 29 ... Dummy pattern, 30 ... Transparent insulating layer, 40 ... Second electrode layer, 42 ... second electrode, 44 ... second electrode terminal, 46 ... second wiring, 50 ... terminal, 54 ... additional second electrode terminal, 56 ... second grating, 59 ... dummy pattern

Claims (9)

1. A first electrode layer having a plurality of first electrodes extending in a first direction and arranged in a second direction intersecting the first direction;
   A transparent insulating layer;
   A second electrode layer having a plurality of second electrodes extending in the second direction and arranged in the first direction, and a conductive sheet laminated in this order,
   The first electrode has a branch electrode extending in the width direction, and the first electrode is composed of a plurality of first lattices made of fine metal wires, and the plurality of first lattices is composed of an M × N lattice group,
   The second electrode has a branch electrode extending in the width direction, and the second electrode is composed of a plurality of second lattices of fine metal wires, and the plurality of second lattices is composed of an M × N lattice group,
   When the first electrode layer and the second electrode layer are viewed from above so that the plurality of first gratings and the plurality of second gratings do not overlap, A conductive sheet in which a plurality of second lattices are continuously arranged on the entire surface, and M and N are integers and M + N ≦ 9.
2. The first electrode has an aperture ratio of 98 to 99.5% and 40 to 80Ω / sq. The second electrode has an aperture ratio of 98-99.8% and 40-80 Ω / sq. The conductive sheet according to claim 1 having a surface resistivity of
3. When the first electrode layer and the second electrode layer are viewed from above so that the plurality of first gratings and the plurality of second gratings do not overlap, 3. The conductive sheet according to claim 1, wherein the plurality of second lattices are adjacent to each other by four or less.
4. The conductive sheet according to any one of claims 1 to 3, wherein a ratio of each of the thin metal wires constituting the first lattice and the second lattice per unit area is 0.2 to 2%.
5. The conductive sheet according to any one of claims 1 to 4, wherein each of the first grid and the second grid has a side of 200 to 1000 µm in length.
6. The conductive sheet according to any one of claims 1 to 5, wherein the first electrode and the second electrode have a width of 4 to 12 mm.
7. The conductive layer according to claim 5 or 6, wherein each of the first grid and the second grid has one side having a length of 240 to 500 µm, and the first electrode and the second electrode have a width of 5 to 7 mm. Sheet.
8. The conductive sheet according to any one of claims 1 to 7, wherein both M and N are 4 or less.
9. A touch panel having the conductive sheet according to claim 1.

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