Sensor, article, method for manufacturing sensor, and electrical conductor

Abstract

To provide a sensor or the like that has good flexibility and can make a bridge wiring portion invisible by using a new invisible technology different from conventional technology. [Solution] A sensor 10 is provided which includes a substrate 11, a first conductive portion 12 provided on the first surface 11A side of the substrate 11, and a second conductive portion 13 provided on the first surface 11A side of the substrate 11 and spaced apart from the first conductive portion 12, wherein the first conductive portion 12 has a plurality of first electrode portions 12A arranged in a first direction DR1 and a wiring portion 12B that electrically connects adjacent first electrode portions 12A, and the second conductive portion 13 has a plurality of second electrode portions 13A arranged in a second direction DR2 that intersects with the first direction DR1 and a bridge wiring portion 13B that straddles the wiring portion 12B and electrically connects adjacent second electrode portions 13A, and the bridge wiring portion 13B includes a resin portion 17B and conductive fibers 18B arranged in the resin portion 17B.

Description

REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority from earlier Japanese applications No. 2020-166235 (filing date: September 30, 2020) and No. 2020-199842 (filing date: December 1, 2020), the entire disclosures of which are incorporated herein by reference. [Technical Field]

[0002] The present invention relates to a sensor, an article, a method for manufacturing a sensor, and an electrical conductor. [Background technology]

[0003] BACKGROUND ART In recent years, some image display devices such as smartphones and tablet terminals are provided with touch sensors that allow information to be directly input by touching the image display surface with a finger or the like.

[0004] Sensors such as touch sensors usually have conductive parts patterned into a predetermined shape on a substrate. Indium tin oxide (ITO) is mainly used as the conductive material for the conductive parts. However, since ITO is not flexible, cracks are likely to occur in the conductive parts when a flexible substrate is used as the substrate.

[0005] For this reason, the use of metal nanowires with nanometer-sized fiber diameters as the conductive material that makes up the conductive portion is currently being considered instead of ITO.

[0006] Meanwhile, a bridge-type sensor is known. A bridge-type sensor includes a substrate, a first conductive portion formed on one surface of the substrate and extending in, for example, the X direction, and a second conductive portion spaced apart from the first conductive portion and extending in, for example, the Y direction. The first conductive portion has a first electrode portion and a wiring portion, and the second conductive portion has a second electrode portion and a bridge wiring portion that straddles the wiring portion of the first conductive portion and separates the second conductive portion from the first conductive portion (see, for example, Patent Document 1).

[0007] When the second electrode is made of conductive nanowires and the bridge wiring is made of an oxide material such as ITO, the dense presence of the oxide material increases the refractive index of the surface of the bridge wiring, making it easier to see the difference in refractive index between the electrode and the bridge wiring.

[0008] Conventionally, known techniques for making bridge wiring portions invisible include refractive index control, thinning of the bridge wiring portion, etc. In Patent Document 1, in order to control the refractive index, a reflection-reducing layer is formed so as to cover the electrode portion and the bridge wiring portion. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] International Publication No. 2018 / 066214 Summary of the Invention [Problem to be solved by the invention]

[0010] However, making the bridge wiring invisible using conventional invisibility techniques such as refractive index control of a reflection-reducing layer as in Patent Document 1 or thinning of the bridge wiring requires a great deal of effort and cost, and therefore a new invisibility technique that differs from conventional techniques is desired for making the bridge wiring invisible.

[0011] In recent years, there has been a demand for forming metal nanowire patterns containing metal nanowires on the three-dimensional surfaces of various shapes of three-dimensional objects. However, when attempting to form such metal nanowire patterns on three-dimensional surfaces, the aspect ratio of the metal nanowires makes it difficult to coat the metal nanowires uniformly, making it difficult to achieve the desired performance, and therefore, it has not been possible to apply this method to three-dimensional surfaces.

[0012] The present invention has been made to solve the above problems. Specifically, it aims to provide a sensor that has good flexibility and can achieve invisibility of the bridge wiring portion using a new invisibility technology different from conventional technologies, an article equipped with this sensor, and a method for manufacturing such a sensor. Another aim is to provide a conductor having a conductive fiber pattern that can be adapted to three-dimensional surfaces of various shapes. [Means for solving the problem]

[0013] The present invention includes the following inventions. [1] A sensor comprising a substrate, a first conductive portion provided on a first surface side of the substrate, and a second conductive portion provided on the first surface side of the substrate and spaced apart from the first conductive portion, wherein the first conductive portion has a plurality of first electrode portions arranged in a first direction and a wiring portion that electrically connects adjacent first electrode portions, the second conductive portion has a plurality of second electrode portions arranged in a second direction that intersects the first direction and a bridge wiring portion that straddles the wiring portion and electrically connects adjacent second electrode portions, and the bridge wiring portion includes a resin portion and conductive fibers arranged in the resin portion.

[0014] [2] A sensor comprising a substrate, a first conductive portion provided on a first surface side of the substrate, and a second conductive portion provided on the first surface side of the substrate and spaced apart from the first conductive portion, wherein the first conductive portion has a plurality of first electrode portions arranged in a first direction and a wiring portion that electrically connects adjacent first electrode portions, the second conductive portion has a plurality of second electrode portions arranged in a second direction that intersects the first direction and a bridge wiring portion that straddles the wiring portion and electrically connects adjacent second electrode portions, the second electrode portions include a conductive material, and the bridge wiring portion includes a resin portion and a conductive material that is arranged in the resin portion and is the same type as the conductive material contained in the second electrode portions.

[0015] [3] The sensor described in [2] above, wherein the conductive material of the second electrode portion and the conductive material of the bridge wiring portion are conductive fibers.

[0016] [4] The sensor according to any one of [1] to [3] above, wherein the width of the second electrode portion is 10 mm or less.

[0017] [5] The sensor according to any one of [1] to [4] above, wherein the width of the bridge wiring portion is 0.35 mm or more.

[0018] [6] The sensor described in any one of [1] to [5] above, wherein the first electrode portion and the wiring portion of the first conductive portion each contain conductive fibers.

[0019] [7] The sensor described in any one of [1] to [6] above, further comprising an electrical insulating layer provided between the wiring portion and the bridge wiring portion.

[0020] [8] The sensor according to [7] above, wherein the absolute value of the difference in refractive index between the bridge wiring portion and the electrical insulating layer is 0.08 or less.

[0021] [9] An article comprising the sensor described in any one of [1] to [8] above.

[0022]

[10] The article according to [9] above, wherein the article is an image display device.

[0023]

[11] A method for manufacturing a sensor, comprising the steps of: arranging first conductive fibers in regions on a first surface side of a substrate where a first conductive section having a plurality of first electrode sections arranged in a first direction and wiring sections electrically connecting adjacent first electrode sections, and a plurality of second electrode sections spaced apart from the first conductive section and arranged in a second direction intersecting the first direction, are to be formed; forming an electrical insulating layer to cover the first conductive fibers arranged in the regions where the wiring sections are to be formed; arranging second conductive fibers in regions on the electrical insulating layer where bridge wiring sections that straddle the wiring sections and electrically connect adjacent second electrode sections are to be formed; and forming a resin layer that covers the first conductive fibers and the second conductive fibers.

[0024]

[12] A method for manufacturing a sensor described in

[11] above, wherein the step of arranging the first conductive fiber comprises the steps of: forming a conductive layer containing a resin portion and the first conductive fiber on the first surface side of the substrate; and removing at least the first conductive fiber present in areas of the conductive layer other than the areas where the first conductive portion and the second electrode portion are to be formed.

[0025]

[13] The method for manufacturing a sensor according to

[11] or

[12] above, wherein the width of the second electrode portion is 10 mm or less.

[0026]

[14] The method for manufacturing a sensor according to any one of

[11] to

[13] above, wherein the width of the bridge wiring portion is 0.35 mm or more.

[0027]

[15] A conductor comprising: a three-dimensional object having a three-dimensional surface; and a conductive portion including a first conductive fiber pattern provided on the three-dimensional surface, consisting of a plurality of conductive fibers, and conforming to the shape of the three-dimensional surface.

[0028]

[16] The conductor described in

[15] above, wherein the three-dimensional object comprises a substrate, a first conductive portion provided on a first surface of the substrate and having a plurality of first electrode portions arranged in a first direction and a wiring portion electrically connecting adjacent first electrode portions, a second conductive fiber pattern provided on the first surface of the substrate, spaced apart from the first conductive portion and arranged in a second direction intersecting the first direction, and consisting of a plurality of conductive fibers, and an electrical insulating layer provided on the wiring portion, wherein the three-dimensional surface is composed of the surface of the electrical insulating layer and the surface of the second conductive fiber pattern, and the first conductive fiber pattern is formed on the surface of the electrical insulating layer between adjacent second conductive fiber patterns so as to straddle the wiring portion and electrically connect adjacent second conductive fiber patterns.

[0029]

[17] A sensor comprising the conductor according to

[15] or

[16] above.

[0030]

[18] An article comprising the sensor described in

[17] above.

[0031]

[19] The article according to

[18] above, wherein the article is an image display device. [Effects of the Invention]

[0032] According to one aspect and another aspect of the present invention, it is possible to provide a sensor that has good flexibility and can achieve invisibility of a bridge wiring portion using a new invisibility technology different from conventional technology, an article that includes this sensor, and a method for manufacturing such a sensor. Also, according to another aspect of the present invention, it is possible to provide a conductor that has a conductive fiber pattern that can be adapted to three-dimensional surfaces of various shapes. [Brief explanation of the drawings]

[0033] [Figure 1] FIG. 1 is a schematic diagram of a sensor (conductor) according to an embodiment. [Figure 2] FIG. 2 is a cross-sectional view of the sensor shown in FIG. 1 taken along line II. [Figure 3] FIG. 3 is a cross-sectional view of the sensor shown in FIG. 1 taken along line II-II. [Figure 4] FIG. 4 is a plan view of the bridge wiring portion of the sensor shown in FIG. [Figure 5] FIG. 5 is a plan view of the samples S1 and S2 when measuring the electrical resistance values. [Figure 6] FIG. 6 is an enlarged view of a portion of sample S1 in FIG. [Figure 7] FIG. 7 is an enlarged view of a portion of sample S2 in FIG. [Figure 8] 8(A) to 8(C) are diagrams showing the folding test in a schematic manner. [Figure 9] FIG. 9 is a plan view of the sample after the folding test. [Figure 10] FIG. 10 is a schematic configuration diagram of another sensor according to the embodiment. [Figure 11] FIG. 11 is a cross-sectional view of the sensor shown in FIG. 10 taken along line III-III. [Figure 12] FIG. 12 is a cross-sectional view of the sensor shown in FIG. 10 taken along line IV-IV. [Figure 13] FIG. 13 is a schematic configuration diagram of another sensor according to the embodiment. [Figure 14] FIG. 14 is a cross-sectional view of the sensor shown in FIG. 13 taken along line VV. [Figure 15] 15(A) and 15(B) are diagrams schematically showing the manufacturing process of the sensor according to the embodiment. [Figure 16] 16(A) and 16(B) are diagrams schematically showing the manufacturing process of the sensor according to the embodiment. [Figure 17] FIG. 17 is a diagram schematically illustrating a manufacturing process of the sensor according to the embodiment. [Figure 18] 18(A) and 18(B) are diagrams schematically showing the manufacturing process of another sensor according to the embodiment. [Figure 19]19(A) and 19(B) are diagrams schematically showing the manufacturing process of another sensor according to the embodiment. [Figure 20] FIG. 20 is a schematic configuration diagram of an image display device according to an embodiment. [Figure 21] FIG. 21 is a cross-sectional view of another conductor according to the embodiment. [Figure 22] FIG. 22 is a schematic diagram of a biosensor according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0034] A sensor, a manufacturing method thereof, an article, and a conductor according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram of a sensor (conductor) according to this embodiment, FIG. 2 is a cross-sectional view of the sensor shown in FIG. 1 taken along line II, and FIG. 3 is a cross-sectional view of the sensor shown in FIG. 1 taken along line II-II. FIG. 4 is a plan view of the bridge wiring portion of the sensor shown in FIG. 1, and FIG. 5 is a plan view of samples S1 and S2 when measuring electrical resistance values. FIG. 6 is an enlarged view of a portion of sample S1 in FIG. 5, FIG. 7 is an enlarged view of a portion of sample S2 in FIG. 5, FIGS. 8(A) to 8(C) are schematic views showing the state of a folding test, and FIG. 9 is a plan view of the sample after the folding test. Figures 10 and 13 are schematic configuration diagrams of another sensor according to the present embodiment, Figure 11 is a cross-sectional view of the sensor shown in Figure 10 taken along line III-III, Figure 12 is a cross-sectional view of the sensor shown in Figure 10 taken along line IV-IV, and Figure 14 is a cross-sectional view of the sensor shown in Figure 13 taken along line VV. Figures 15 and 16 are diagrams schematically showing a manufacturing process for the sensor according to the present embodiment, Figures 17 to 19 are diagrams schematically showing a manufacturing process for another sensor according to the present embodiment, Figure 20 is a schematic configuration diagram of an image display device according to the present embodiment, Figure 21 is a cross-sectional view of another conductor according to the embodiment, and Figure 22 is a schematic configuration diagram of a biosensor according to the embodiment.

[0035] <<<Sensor>>> 1 includes a substrate 11, a first conductive portion 12 provided on a first surface 11A side of the substrate 11, a second conductive portion 13 provided on the first surface 11A side of the substrate 11 and spaced apart from the first conductive portion 12, an electrical insulating layer 14 provided between a wiring portion 12B and a bridge wiring portion 13B (described later), and an extraction wiring portion 15 electrically connected to a first electrode portion 12A (described later). Note that the sensor 10 is an example of a conductor (described later).

[0036] Although the sensor 10 includes the electrical insulating layer 14, as long as the first conductive portion 12 and the second conductive portion 13 are spaced apart, the sensor 10 does not necessarily have to include the electrical insulating layer 14. Furthermore, the sensor 10 includes the extracting wiring portion 15, but the extracting wiring portion 15 does not necessarily have to be included.

[0037] The first conductive portion 12 has a plurality of first electrode portions 12A arranged in a first direction DR1 (see FIG. 1) and a wiring portion 12B that electrically connects adjacent first electrode portions 12A. The second conductive portion 13 has a plurality of second electrode portions 13A arranged in a second direction DR2 (see FIG. 1) that intersects with the first direction DR1 and a bridge wiring portion 13B that straddles the wiring portion 12B and electrically connects adjacent second electrode portions 13A. Here, in this specification, "straddles the wiring portion" means that the bridge wiring portion extends from a second electrode portion, passes above the wiring portion, and to an adjacent second electrode portion. In FIG. 1, the second direction DR2 is perpendicular to the first direction DR1.

[0038] The haze value (total haze value) of the sensor 10 is preferably 5% or less. A haze value of 5% or less ensures sufficient optical performance. The haze value can be measured in accordance with JIS K7136:2000 using a haze meter (e.g., product name "HM-150" manufactured by Murakami Color Research Laboratory) at a temperature of 23±5°C and a relative humidity of 30% to 70%. The haze value is the value measured across the entire sensor. A sample measuring 50 mm x 100 mm is obtained from the sensor, and the sample is placed with the first conductive part facing away from the light source, free of curls, wrinkles, fingerprints, dust, etc., and measured three or more times for each sample. The arithmetic mean value of the measured values ​​is used. In this specification, "measured three or more times" does not mean measuring the same location three or more times, but rather measuring three or more different locations on the sample. Measuring the haze value at three or more different locations on a cut sample is believed to provide an approximate average haze value across the entire sensor surface. It is preferable to measure five times, i.e., at five different locations, and then calculate the average value from the measurements at three locations, excluding the maximum and minimum values. If the sample cannot be cut to the above size, for example, the HM-150 has an entrance opening of 20 mmφ for measurement, so a sample with a diameter of 21 mm or larger is required. Therefore, a sample with a size of 22 mm x 22 mm or larger may be cut out. If the sample is small, the measurement points can be set to three by gradually shifting the sample or changing the angle within the range where the light source spot does not shift. It is more preferable that the haze value of the sensor 10 be 3% or less, 2% or less, 1.5% or less, 1.2% or less, or 1.1% or less. The variation in the obtained haze value is within 30%, preferably within ±10%, even when the measurement object is as long as 1 m × 3000 m or as small as a 5-inch smartphone. When the variation is within the above preferred range, low haze and low resistance are more likely to be obtained. It is also preferable that the same haze value be obtained for the entire laminate, in which multiple layers are stacked, such as a touch panel equipped with a sensor.

[0039] The total light transmittance of the sensor 10 is preferably 80% or more. A total light transmittance of 80% or more of the sensor 10 ensures sufficient optical performance. The total light transmittance can be measured in accordance with JIS K7361-1:1997 using a haze meter (e.g., product name "HM-150" manufactured by Murakami Color Research Laboratory) in an environment with a temperature of 23±5°C and a relative humidity of 30% to 70%. The total light transmittance of the sensor 10 is more preferably 85% or more, 88% or more, or 89% or more. The total light transmittance is measured at five locations, and the average value of the three total light transmittances measured at the five locations, excluding the maximum and minimum values, is used.

[0040] Even when a folding test (folding test) is repeatedly performed 100,000 times in which the sensor 10 is folded 180° so that the distance φ between opposing sides of the sensor 10 is 3 mm, the electrical resistance ratio (described below) of the first conductive portion 12 and the electrical resistance ratio of the second conductive portion 13 of the sensor 10 before and after the folding test are preferably 3 or less. When the folding test is repeatedly performed 100,000 times on the sensor, if the electrical resistance ratio of the first conductive portion and the electrical resistance ratio of the second conductive portion of the sensor before and after the folding test exceed 3, the sensor may have cracks or other defects, resulting in insufficient flexibility. If cracks or other defects occur in the sensor as a result of the folding test, the conductivity of the sensor decreases, and the electrical resistance of the conductive portion of the sensor after the folding test increases compared to the electrical resistance of the conductive portion of the sensor before the folding test. Therefore, determining the electrical resistance ratio of the conductive portion of the sensor before and after the folding test can determine whether cracks or other defects have occurred in the sensor. The folding test may be performed by folding the sensor 10 so that the first conductive portion 12 and the second conductive portion 13 are on the inside, or may be performed by folding the sensor 10 so that the first conductive portion 12 and the second conductive portion 13 are on the outside, but in either case, it is preferable that the ratio of the electrical resistance values ​​of the first conductive portion 12 and the second conductive portion 13 of the sensor 10 before and after the folding test is 3 or less.

[0041] Whether the folding test involves 200,000, 300,000, 500,000, or 1,000,000 folding cycles, it is more preferable that the ratio of the electrical resistance values ​​of the first conductive portion 12 and the second conductive portion 13 of sensor 10 before and after the folding test be 3 or less. The greater the number of folding cycles, the more difficult it becomes to achieve a ratio of the electrical resistance values ​​of the conductive portions before and after the folding test of 3 or less. Therefore, there is a significant technical difference between a ratio of the electrical resistance values ​​of the first conductive portion 12 and the second conductive portion 13 before and after the folding test involving 200,000, 300,000, 500,000, or 1,000,000 folding cycles being 3 or less and a ratio of the electrical resistance values ​​of the first conductive portion 12 and the second conductive portion 13 before and after the folding test involving 100,000 folding cycles being 3 or less. The reason for evaluating the folding test involves a folding cycle of at least 100,000 cycles is as follows. For example, if a sensor is incorporated into a foldable smartphone, the frequency of folding (opening and closing) will be extremely high. Therefore, evaluations based on the number of folds in the folding test, such as 10,000 or 50,000 times, may not be practical. Specifically, for example, assuming a person who regularly uses a smartphone, it is expected that the smartphone will be opened and closed 5 to 10 times just during the morning commute on a train or bus, meaning that the smartphone will be opened and closed at least 30 times per day. Therefore, assuming that a smartphone is opened and closed 30 times per day, a folding test with 10,000 folds would be 30 times x 365 days = 10,950 folds, which is a test based on one year of use. In other words, even if the results of the folding test with 10,000 folds are good, there is a risk that the sensor will develop creases or cracks after one year. Therefore, an evaluation of 10,000 folds in a folding test can only confirm a level at which the product cannot be used as a product, and products that are usable but not sufficient will also be classified as good and cannot be evaluated. For this reason, in order to evaluate whether a product is at a practical level, the folding test must be performed at least 100,000 times.

[0042] Regardless of whether the number of folds in the folding test is 100,000, 200,000, 300,000, 500,000 or 1,000,000, it is more preferable that the electrical resistance ratio of the first conductive part 12 and the second conductive part 13 of the sensor 10 before and after the folding test is 1.5 or less.

[0043] The folding test is performed with the distance φ between the opposing sides of sensor 10 set to 3 mm, but from the perspective of reducing the thickness of the image display device, even when the folding test is performed by folding sensor 10 by 180° 100,000 times with the distance φ between the opposing sides of sensor 10 set to a narrower range, specifically 2 mm or 1 mm, it is more preferable that the ratio of the electrical resistance values ​​of first conductive portion 12 and second conductive portion 13 before and after the folding test be 3 or less. Note that even when the number of foldings is the same, it becomes more difficult to achieve a ratio of the electrical resistance values ​​of the conductive portions before and after the folding test of 3 or less as the distance φ becomes narrower. Therefore, there is a significant technical difference between a ratio of the electrical resistance values ​​of first conductive portion 12 and second conductive portion 13 before and after a folding test with the distance φ set to 2 mm or 1 mm and a ratio of the electrical resistance values ​​of first conductive portion 12 and second conductive portion 13 before and after a folding test with the distance φ set to 3 mm.

[0044] When conducting the folding test, first, samples S1 and S2 of a predetermined size (for example, a rectangular shape of 125 mm length x 50 mm width) are cut out from any position of sensor 10 before the folding test so as to include first conductive portion 12 and second conductive portion 13 (see FIG. 5). Here, sample S1 is cut out from sensor 10 so that the longitudinal direction of sample S1 is the direction in which first conductive portion 12 extends (conduction direction), and sample S2 is cut out from sensor 10 so that the longitudinal direction of sample S2 is the direction in which second conductive portion 13 extends (conduction direction). Note that if it is not possible to cut out samples of 125 mm x 50 mm, any size that allows for the various evaluations described below to be performed after the folding test may be used; for example, a rectangular sample of 80 mm x 25 mm may be cut out. Samples S1 and S2 were cut out from sensor 10 before the folding test, and then the electrical resistance value of first conductive portion 12 was measured for sample S1 before the folding test, and the electrical resistance value of second conductive portion 13 was measured for sample S2 before the folding test. Specifically, as shown in Fig. 5, silver paste (product name "DW-520H-14", manufactured by Toyobo Co., Ltd.) was applied to both longitudinal ends of samples S1 and S2 (e.g., portions measuring 10 mm in length and 50 mm in width) to prevent fluctuations in the measurement distance of the electrical resistance value, and the samples were heated at 130°C for 30 minutes, providing hardened silver paste 21 on both ends of samples S1 and S2. Thereafter, in sample S1, the hardened silver paste 21 is irradiated with laser light to remove a portion of the silver paste 21 so that the first conductive portion 12 is not electrically conductive with the second conductive portion 13, and in sample S2, the hardened silver paste 21 is irradiated with laser light to remove a portion of the silver paste 21 so that the second conductive portion 13 is not electrically conductive with the first conductive portion 12 (see FIGS. 6 and 7). Note that the portion indicated by reference numeral 21A in FIGS. 6 and 7 is the portion from which the silver paste 21 has been removed. In this state, the electrical resistance value of each sample is measured using a tester (product name "Digital MΩ Hitester 3454-11", manufactured by Hioki E.E. Corporation).The distance between the silver pastes 21 (the distance between the portions where the silver paste 21 is not provided) is the measurement distance (e.g., 100 mm) for the electrical resistance values ​​of samples S1 and S2, and this measurement distance is constant between samples S1 and S2. When measuring the electrical resistance value, for sample S1, the probe terminals of a tester are brought into contact with the portions of the hardened silver paste 21 provided at both ends that are in contact with the first conductive portion 12, and for sample S2, the probe terminals of the tester are brought into contact with the portions of the hardened silver paste 21 provided at both ends that are in contact with the second conductive portion 13. The electrical resistance value is measured in an environment with a temperature of 23±5°C and a relative humidity of 30% to 70%. The electrical resistance value of the first conductive portion 12 is measured for sample S1 before the folding test, and the electrical resistance value of the second conductive portion 13 is measured for sample S2 before the folding test. Then, samples S1 and S2 are each subjected to a folding test.

[0045] The folding test is performed as follows. As shown in FIG. 8A, in the folding test, first, side S1a and side S1b of the selected sample S1 are fixed by the fixing parts 22 of a parallel-arranged folding endurance tester (for example, a "U-shaped extension tester DLDMLH-FS" manufactured by Yuasa System Co., Ltd., conforming to IEC 62715-6-1). Fixation by the fixing parts 22 is performed by holding a portion of the sample S1 approximately 10 mm on each side in the longitudinal direction of the sample S1. However, if the sample S1 is smaller than the above size, measurement is possible by attaching it to the fixing parts 22 with tape, provided that the portion of the sample S1 required for fixation is up to approximately 20 mm (i.e., the smallest sample is 60 mm × 25 mm). Furthermore, as shown in FIG. 8A, the fixing parts 22 are slidable horizontally. The above-described device is preferable because it allows evaluation of durability against bending load without generating tension or friction in the sample, unlike conventional methods such as winding a sample around a rod.

[0046] Next, as shown in Figure 8(B), the fixing portions 22 are moved closer to each other, thereby deforming the central portion S1c of the sample S1 in a folding manner, and then, as shown in Figure 8(C), the fixing portions 22 are moved to a position where the distance φ between the two opposing side portions S1a, S1b of the sample S1 fixed by the fixing portions 22 is 3 mm, and then the fixing portions 22 are moved in the opposite direction to eliminate the deformation of the sample S1.

[0047] As shown in Figures 8(A) to 8(C), sample S1 can be folded 180° at the center portion S1c by moving the fixing portion 22. Furthermore, by ensuring that the bent portion S1d of sample S1 does not protrude from the lower end of the fixing portion 22, conducting the folding test under the following conditions, and controlling the distance between the fixing portions 22 to 3 mm when they are closest, the distance φ between the two opposing sides S1a and S1b of sample S1 can be set to 3 mm. In this case, the outer diameter of the bent portion S1d is considered to be 3 mm. Note that because the thickness of sample S1 is sufficiently small compared to the distance between the fixing portions 22 (3 mm), the results of the folding test of sample S1 can be considered unaffected by differences in the thickness of sample S1. (Folding conditions) Reciprocating speed: 80 rpm (revolutions per minute) Test stroke: 60mm Flexion angle: 180°

[0048] After the folding test, the electrical resistance of the first conductive portion 12 is measured for the sample S1 after the folding test in the same manner as for the sample S1 before the folding test. The ratio of the electrical resistance of the sample S1 after the folding test to the electrical resistance of the sample S1 before the folding test (electrical resistance of the sample S1 after the folding test / electrical resistance of the sample S1 before the folding test) is then calculated. The electrical resistance ratio is calculated by measuring the electrical resistance ratio five times, i.e., at five different locations, and excluding the maximum and minimum values ​​from the five measured electrical resistance ratios, and then calculating the arithmetic mean value of three electrical resistance ratios. Similarly, the ratio of the electrical resistance of the sample S2 after the folding test to the electrical resistance of the sample S2 before the folding test (electrical resistance of the sample S2 after the folding test / electrical resistance of the sample S2 before the folding test) is calculated.

[0049] When the sensor is subjected to the folding test described above, even if the electrical resistance ratio of the first conductive part and the second conductive part of the sensor before and after the folding test is 3 or less, folding creases and microcracks may occur at the bent parts, resulting in poor appearance, specifically, cloudiness and delamination (poor adhesion) initiated by the microcracks. One cause of cloudiness is thought to be a change in the crystalline state of the organic compounds that make up one of the sensor's layers. If localized poor adhesion occurs, changes in temperature and humidity can cause moisture to accumulate at the delamination or air to enter the delamination, potentially increasing the cloudiness. Microcracks rarely occur in substrates alone or in laminates with some functional layer on top of the substrate. While the origin of the cracks is unknown, it is suspected that the conductive part containing conductive fibers is a contributing factor. In recent years, displays have become more diverse, ranging from flat to foldable, curved, and featuring diverse three-dimensional designs. Therefore, preventing folding creases and microcracks at the bent parts is extremely important for use as image display devices. For these reasons, it is preferable that the sensor 10 have excellent flexibility. In this specification, "excellent flexibility" means not only that the ratio of the electrical resistance values ​​of the conductive parts before and after the folding test is 3 or less, but also that no creases or microcracks are observed.

[0050] The observation of fold creases is to be carried out visually, but when observing fold creases, the bend should be observed thoroughly using transmitted and reflected light in a bright room with white lighting (800 lux to 2000 lux), and both the inside and outside of the bend should be observed. The observation of fold creases should be carried out in an environment with a temperature of 23±5°C and a relative humidity of 30% to 70%.

[0051] The microcracks are observed using a digital microscope. An example of a digital microscope is the VHX-5000 manufactured by Keyence Corporation. Microcracks are observed using a ring light as the digital microscope's illumination, and in dark field and reflected light. Specifically, the sample after the folding test is first slowly unfolded and fixed to the microscope stage with tape. If the fold is severe, the area to be observed is made as flat as possible. However, the area to be observed near the center of the sample (the bent portion) is not touched with the hands, and no force is applied. Both the inside and outside portions of the sample that will be folded are then observed. The microcrack observation is performed in an environment with a temperature of 23±5°C and a relative humidity of 30% to 70%.

[0052] In observing the fold creases and microcracks, the sample before the folding test is placed on a fixed portion of a durability tester, and when folded once, marks A1 indicating the bent portion can be marked with an oil-based pen or the like on both ends S1d1 of the bent portion S1d that are located in a direction perpendicular to the folding direction FD, as shown in FIG. 9. Furthermore, in the case of a sample in which no fold creases or the like are observed after the folding test, a line A2 (dotted line in FIG. 9) connecting the marks A1 on both ends S1d1 of the bent portion S1d can be drawn with an oil-based pen or the like after the sample is removed from the durability tester after the folding test to prevent the observation position from becoming unclear. Then, in observing the fold creases, the entire bent portion S1d, which is the area formed by the marks A1 on both ends S1d1 of the bent portion S1d and the line A2 connecting these marks A1, is visually observed. When observing microcracks, the microscope is positioned so that the center of the microscope field of view (the area surrounded by the two-dot chain line in Figure 9) is at the center of the bend S1d. Note that care should be taken not to mark areas required for actual measurements with oil-based pens or the like.

[0053] Furthermore, when the sensor is subjected to the folding test, the adhesion between the substrate and the resin layer may be reduced. Therefore, when the interface between the substrate 11 and the resin layer 17 (described later) is observed with a digital microscope at the bent portion of the sensor after the folding test, it is preferable that no peeling or the like is observed near the interface between the substrate 11 and the resin layer 17. An example of a digital microscope is the VHX-5000 manufactured by Keyence Corporation.

[0054] If another film is attached to the sensor via an adhesive layer or bonding layer, the adhesive layer and the other film are peeled off together before measuring the haze value and total light transmittance, and also performing a folding test. Peeling of the other film can be performed, for example, as follows: First, a laminate in which the other film is attached to the sensor via an adhesive layer or bonding layer is heated with a dryer, and the tip of a cutter is inserted into the area believed to be the interface between the sensor and the other film, and the film is slowly peeled off. Repeating this heating and peeling process allows the adhesive layer, bonding layer, and other film to be peeled off. Note that even if such a peeling process is performed, it does not significantly affect the measurement of the haze value or the folding test.

[0055] As described above, when measuring the haze value and total light transmittance of sensor 10 or when performing a folding test on sensor 10, samples of the respective sizes must be cut from sensor 10. However, if sensor 10 is large (e.g., if it is long, such as in a roll), a sample of A4 size (210 mm x 297 mm) or A5 size (148 mm x 210 mm) is cut from an arbitrary position, and then samples of the respective measurement item sizes are cut. Furthermore, if sensor 10 is in a roll, a predetermined length of sensor 10 is unwound from the roll, and samples are cut from the effective area near the center, where quality is stable, rather than from the ineffective area including both ends extending along the longitudinal direction of the roll. Furthermore, when measuring the haze value and total light transmittance of sensor 10 or performing a folding test on sensor 10, measurements are made using the above-mentioned device. However, measurements may also be made using a similar device, such as a successor model, instead of the above-mentioned device.

[0056] The thickness of sensor 10 is not particularly limited, but can be 500 μm or less. From the viewpoints of ease of handling and thinning, the thickness of sensor 10 is more preferably 5 μm to 500 μm, 5 μm to 250 μm, 5 μm to 100 μm, 10 μm to 500 μm, 10 μm to 250 μm, 10 μm to 100 μm, 20 μm to 500 μm, 20 μm to 250 μm, or 20 μm to 100 μm. Furthermore, when flexibility is more important, the thickness of sensor 10 is more preferably 5 μm to 78 μm, 10 μm to 78 μm, or 20 μm to 78 μm, particularly preferably 5 μm to 45 μm, 10 μm to 45 μm, or 20 μm to 45 μm. Therefore, when flexibility is more important, the thickness of the sensor 10 is preferably 5 μm to 78 μm, more preferably 5 μm to 28 μm, or even 5 μm to 20 μm. The thickness of the sensor 10 is determined by measuring the thickness at 10 random locations on a cross-sectional photograph of the sensor taken using a transmission electron microscope (TEM), a scanning transmission electron microscope (STEM), or a scanning electron microscope (SEM), and excluding the maximum and minimum values ​​from the 10 thickness measurements to obtain the average value of 8 thicknesses. Sensors generally have thickness variations. In this embodiment, since the sensor is used for optical applications, the thickness variation is preferably within ±2 μm of the average thickness, and even more preferably within ±1 μm.

[0057] When measuring the thickness of the sensor using a transmission electron microscope (TEM) or a scanning transmission electron microscope (STEM), the measurement can be performed using a method similar to that used to measure the thickness of the first conductive portion 12. However, the magnification when taking a cross-sectional photograph of the sensor is 100 to 20,000 times. When measuring the thickness of the sensor using a scanning electron microscope (SEM), the cross-section of the sensor can be obtained using an ultramicrotome (product name "Ultramicrotome EM UC7", manufactured by Leica Microsystems) or the like. Note that, for measurement with a TEM or STEM, the sample is prepared by using the above-mentioned ultramicrotome to prepare an ultrathin section with a feed thickness set to 100 nm. The prepared ultrathin section is then collected using a collodion-coated mesh (150) to serve as the sample. When cutting with the ultramicrotome, the sample may be pre-treated to make it easier to cut, such as by embedding it in resin.

[0058] The application of the sensor of the present invention (e.g., sensor 10 shown in FIG. 1 ) is not particularly limited, and the sensor of the present invention can be used in a variety of products. Specifically, the sensor of the present invention may be used, for example, in optical applications or touch panel applications. The sensor of the present invention is also suitable for image display devices (including smartphones, tablet devices, wearable devices, personal computers, televisions, digital signage, public information displays (PIDs), in-vehicle displays, etc.) and in-vehicle applications (including all types of vehicles, such as trains and construction machinery). When used as an in-vehicle sensor, it can be placed in areas that people touch, such as steering wheels and seats. The sensor is also preferred for applications requiring flexibility, such as foldability and rollability. Furthermore, it may be used in electrical appliances and windows used in homes and cars (including all types of vehicles, such as trains and construction machinery). In particular, the sensor of the present invention is suitable for use in areas where transparency is important. The sensor of the present invention can also be suitable for use in electrical appliances that require aesthetic appeal and design, in addition to technical aspects such as transparency. Specific applications of the sensor other than image display devices include, for example, biosensors, defrosters, antennas, solar cells, audio systems, speakers, electric fans, electronic whiteboards, carrier films for semiconductors, etc. The shape of the sensor when in use is not particularly limited as it is designed appropriately depending on the application, but may be, for example, curved.

[0059] The sensor 10 may be cut to a desired size or may be in a roll. If the sensor is in a roll, it may be cut to a desired size at this stage. If the sensor 10 is cut to a desired size, the size of the sensor is not particularly limited and is determined appropriately depending on the size of the display surface of the image display device. Specifically, the size of the sensor may be, for example, 5 inches to 500 inches. In this specification, "inches" refers to the length of the diagonal if the sensor is rectangular, the diameter if the sensor is circular, and the average value of the sum of the minor axis and the major axis if the sensor is elliptical. Here, if the sensor is rectangular, the aspect ratio of the sensor used to calculate the inches is not particularly limited as long as it does not cause any problems as a display screen for the image display device. Examples include height:width = 1:1, 4:3, 16:10, 16:9, and 2:1. However, these aspect ratios are not limited, particularly for in-vehicle applications and digital signage, which require sophisticated design. Furthermore, if the sensor 10 is large, it is cut from any position into an easily manageable size such as A4 size (210 mm x 297 mm) or A5 size (148 mm x 210 mm), and then cut into the size of each measurement item. Note that, for example, if the sensor 10 is in roll form, a predetermined length of the sensor 10 is unwound from the roll, and the desired size is cut from the effective region near the center where quality is stable, rather than from the ineffective region including both ends extending along the longitudinal direction of the roll.

[0060] <<Base material>> The substrate 11 is not particularly limited, but it is preferable that it be optically transparent depending on the application. For example, when the sensor 10 is used for optical applications, it is preferable that the substrate be optically transparent. In this specification, "optically transparent" means the property of transmitting light. Furthermore, "optically transparent" does not necessarily mean transparent, but may also be translucent.

[0061] Examples of materials constituting the light-transmitting substrate 11 include substrates containing light-transmitting resins. Such resins are not particularly limited as long as they are light-transmitting, but examples include polyolefin-based resins, polycarbonate-based resins, polyacrylate-based resins, polyester-based resins, aromatic polyetherketone-based resins, polyethersulfone-based resins, polyimide-based resins, polyamide-based resins, polyamideimide-based resins, and mixtures of two or more of these resins. Substrates are easily scratched when they come into contact with a coating device during coating of the first conductive portion, etc. However, substrates made of polyester-based resins are less susceptible to scratches even when they come into contact with the coating device, thereby suppressing an increase in haze value. Furthermore, polyester-based resins are superior to substrates made of light-transmitting resins other than polyester-based resins in terms of heat resistance, barrier properties, and water resistance. Therefore, polyester-based resins are preferred.

[0062] When obtaining a foldable sensor, it is preferable to use a polyimide resin, a polyamideimide resin, a polyamide resin, a polyester resin, or a mixture thereof as the resin constituting the substrate, because of its good flexibility. Among these, polyimide resins, polyamide resins, or mixtures thereof are preferable, because they not only have excellent flexibility but also excellent hardness and transparency, and are also excellent in heat resistance, and can be imparted with even better hardness and transparency by baking.

[0063] Examples of polyolefin resins include resins containing at least one of polyethylene, polypropylene, cycloolefin polymer resins, etc. Examples of cycloolefin polymer resins include those having a norbornene skeleton.

[0064] Examples of polycarbonate resins include aromatic polycarbonate resins based on bisphenols (such as bisphenol A), and aliphatic polycarbonate resins such as diethylene glycol bisallyl carbonate.

[0065] Examples of polyacrylate resins include polymethyl(meth)acrylate-based resins, polyethyl(meth)acrylate-based resins, and methyl(meth)acrylate-butyl(meth)acrylate copolymers.

[0066] Examples of polyester resins include resins containing at least one of polyethylene terephthalate (PET), polypropylene terephthalate, polybutylene terephthalate (PBT), and polyethylene naphthalate (PEN). Of these, PET is preferred for the following reasons:

[0067] Examples of aromatic polyether ketone resins include polyether ether ketone (PEEK).

[0068] The polyimide resin may partially contain a polyamide structure. Examples of the polyamide structure include a polyamideimide structure containing a tricarboxylic acid residue such as trimellitic anhydride, and a polyamide structure containing a dicarboxylic acid residue such as terephthalic acid. The polyamide resin is a concept that includes not only aliphatic polyamides but also aromatic polyamides (aramids). Specifically, examples of the polyimide resin include compounds having structures represented by the following chemical formulas (1) and (2). In the following chemical formulas, n is a repeating unit and represents an integer of 2 or more. Among the compounds represented by the following chemical formulas (1) and (2), the compound represented by chemical formula (1) is preferred because it has low retardation and high transparency. [ka] [ka]

[0069] The thickness of the substrate 11 is not particularly limited, but can be 500 μm or less. From the viewpoint of handleability and thinning, the thickness of the substrate 11 can be set to 3 μm or more and 500 μm or less, 3 μm or more and 250 μm or less, 3 μm or more and 100 μm or less, 3 μm or more and 80 μm or less, 3 μm or more and 50 μm or less, 5 μm or more and 500 μm or less, 5 μm or more and 250 μm or less, 5 μm or more and 100 μm or less, More preferably, the thickness of the substrate 11 is 5 μm to 80 μm, 5 μm to 50 μm, 10 μm to 500 μm, 10 μm to 250 μm, 10 μm to 100 μm, 10 μm to 80 μm, 10 μm to 50 μm, 20 μm to 500 μm, 20 μm to 250 μm, 20 μm to 100 μm, 20 μm to 80 μm, or 20 μm to 50 μm. Furthermore, when flexibility is more important, the thickness of the substrate 11 is more preferably 3 μm to 35 μm, 5 μm to 35 μm, 10 μm to 35 μm, or 20 μm to 35 μm, particularly preferably 3 μm to 18 μm, 5 μm to 18 μm, or 10 μm to 18 μm. The thickness of the substrate is determined by measuring the thickness at 10 random locations on a cross-sectional photograph of the substrate taken using a transmission electron microscope (TEM), scanning transmission electron microscope (STEM), or scanning electron microscope (SEM), and excluding the maximum and minimum values ​​from the 10 thickness measurements, averaging the thicknesses at 8 locations. Substrates generally have thickness variations. When the substrate is used for optical purposes, the thickness variation is preferably within ±2 μm of the average thickness, and more preferably within ±1 μm.

[0070] When measuring the thickness of the substrate using a transmission electron microscope (TEM) or a scanning transmission electron microscope (STEM), the thickness can be measured using a method similar to that used to measure the thickness of the first conductive portion 12. However, the magnification when taking a cross-sectional photograph of the substrate 11 is 100 to 20,000 times. When measuring the thickness of the substrate using a scanning electron microscope (SEM), the cross-section of the substrate can be obtained using an ultramicrotome (product name "Ultramicrotome EM UC7", manufactured by Leica Microsystems) or the like. Note that samples for TEM and STEM are prepared by using the above-mentioned ultramicrotome to prepare ultrathin sections with a feed thickness set to 100 nm. The prepared ultrathin sections are collected using a collodion-coated mesh (150) to serve as samples for TEM and STEM. When cutting with the ultramicrotome, the sample may be pre-treated to make it easier to cut, such as by embedding it in resin.

[0071] Conductive fibers such as silver nanowires are suitable for flexibility. However, if the substrate or resin layer used to laminate the conductive fiber-containing conductive portion is too thick, cracks may occur in the substrate or resin layer at the bends during folding. These cracks may cause the conductive fibers to break, and may also cause creases or microcracks in the substrate or resin layer at the bends. These breaks may result in the failure to achieve the desired resistance value and may also cause poor appearance, specifically, cloudiness or poor adhesion due to cracks. For this reason, controlling the thickness of the substrate and resin layer and the adhesion between each layer (adhesion due to chemical bonds affected by the materials, or physical adhesion that prevents cracks) are important when using sensors for flexible applications. In particular, controlling the thickness of the substrate is important when the substrate 11 contains a polyester-based resin or a polyimide-based resin, because the resistance to cracking varies depending on the thickness.

[0072] When the substrate 11 contains, for example, a polyester resin, the thickness of the substrate 11 is preferably 45 μm or less. If the thickness of the substrate 11 is 45 μm or less, cracking of the substrate 11 at the bent portion when folded can be suppressed, and clouding at the bent portion can also be suppressed. In this case, from the viewpoint of handleability and the like, the thickness of the substrate 11 is preferably 5 μm or more and 45 μm or less, 5 μm or more and 35 μm or less, or 5 μm or more and 29 μm or less, particularly preferably 5 μm or more and 18 μm or less.

[0073] When substrate 11 contains, for example, a polyimide resin, a polyamide resin, a polyamideimide resin, or a mixture thereof, the thickness of substrate 11 is preferably thin, specifically 75 μm or less, from the viewpoints of preventing cracking of substrate 11 during folding and of optical and mechanical properties. In this case, the thickness of substrate 11 is preferably 5 μm to 70 μm, 5 μm to 50 μm, 5 μm to 35 μm, 5 μm to 29 μm, and particularly 5 μm to 20 μm, or 5 μm to 18 μm, from the viewpoints of handleability and the like.

[0074] When the thickness of each of the above substrates is 5 μm or more and 35 μm or less, particularly 5 μm or more and 20 μm or more or 5 μm or more and 18 μm or less, it is preferable to apply a protective film during production, as this improves processability.

[0075] The substrate 11 may have a surface that has been subjected to physical treatments such as corona discharge treatment and oxidation treatment to improve adhesion. The substrate 11 may also have a primer layer on at least one side to improve adhesion to other layers, prevent sticking during winding, and / or suppress repelling of coating solutions forming other layers. However, if a conductive portion is formed on the surface of the primer layer using a conductive fiber dispersion containing conductive fibers and a dispersion medium, the dispersion medium may penetrate the primer layer, causing the conductive fibers to also penetrate into the primer layer, resulting in an increase in electrical resistance, although this may vary depending on the type of dispersion system. Therefore, it is preferable that the substrate does not have a primer layer on the conductive portion side, and the conductive portion is provided directly on the substrate. In this specification, a primer layer that is present on at least one side of the substrate and in contact with the substrate is considered to be part of the substrate.

[0076] The underlayer has the functions of improving adhesion with other layers, preventing sticking during winding, and / or suppressing the repelling of coating solutions for forming other layers. Whether or not the substrate has an underlayer can be confirmed by observing the cross section of the interface between the substrate 11 and the first conductive part 12 and the interface between the substrate 11 and the resin layer 17 at 1,000 to 500,000 magnifications (preferably 25,000 to 50,000 magnifications) using a scanning electron microscope (SEM), a scanning transmission electron microscope (STEM), or a transmission electron microscope (TEM). Note that the underlayer may contain particles such as a lubricant to prevent sticking during winding, and therefore the presence of particles between the substrate and the first conductive part and the second electrode part can also determine that this layer is an underlayer.

[0077] The thickness of the underlayer is preferably 10 nm or more and 1 μm or less. When the thickness of the underlayer is 10 nm or more, it fully functions as an underlayer, and when the thickness of the underlayer is 1 μm or less, there is no risk of optical influence. The thickness of the underlayer is determined by measuring the thickness at 10 random locations on a cross-sectional photograph of the underlayer taken at 1,000 to 500,000 magnifications (preferably 25,000 to 50,000 magnifications) using a scanning electron microscope (SEM), a scanning transmission electron microscope (STEM), or a transmission electron microscope (TEM), and excluding the maximum and minimum thicknesses from the 10 measured locations, and then calculating the arithmetic mean value of the thicknesses at eight locations. The thickness of the underlayer is more preferably 10 nm or more and 150 nm or less, 30 nm or more and 1 μm or less, or 30 nm or more and 150 nm or less. The thickness of the underlayer can also be measured using the same method as for the thickness of the first conductive part 12. When taking a cross-sectional photograph using an SEM, TEM, or STEM, it is preferable to prepare a sample using an ultramicrotome as described above.

[0078] The underlayer contains, for example, an anchor agent or a primer agent. Examples of the anchor agent or primer agent that can be used include at least one of polyurethane resin, polyester resin, polyvinyl chloride resin, polyvinyl acetate resin, vinyl chloride-vinyl acetate copolymer, acrylic resin, polyvinyl alcohol resin, polyvinyl acetal resin, copolymer of ethylene with vinyl acetate or acrylic acid, copolymer of ethylene with styrene and / or butadiene, thermoplastic resin such as olefin resin and / or modified resin thereof, polymer of ionizing radiation polymerizable compound, and polymer of thermally polymerizable compound.

[0079] The underlayer may contain particles such as a lubricant to prevent sticking during winding, as described above. Examples of the particles include silica particles.

[0080] <<First conductive part>> The first conductive portion 12 is an electrically conductive portion. When determining conductivity from the surface resistance of the first conductive portion 12, if the surface resistance of the first conductive portion 12 is less than 2000 Ω / □, it can be determined that electrical conductivity is obtained from the first conductive portion 12. The surface resistance of the first conductive portion 12 is determined as follows. First, a sample S1 for a folding test is prepared. After obtaining the sample S1, the resistance is measured by contacting the probe terminal of a tester (product name "Digital MΩ Hitester 3454-11", manufactured by Hioki E.E. Corporation) with the hardened silver paste 21 in an environment of a temperature of 23±5°C and a relative humidity of 30% to 70%. Specifically, the Digital MΩ Hitester 3454-11 has two probe terminals (a red probe terminal and a black probe terminal, both pin-shaped), and the resistance value is measured by contacting the red probe terminal with the portion of one hardened silver paste 21 that is in contact with first conductive portion 12, and the black probe terminal with the portion of the other hardened silver paste 21 that is in contact with first conductive portion 12. Then, the surface resistance value of first conductive portion 12 is calculated using the following formula (1). Rs = R × (C W ×C N / C L ) …(1) In the above formula (1), Rs is the surface resistance value (Ω / □), R is the measured resistance value (Ω), and C W is the line width (μm) of one first conductive part, and C N is the number of first conductive parts, and C L is the line length (μm) of the first conductive part.

[0081] The surface resistance value of the first conductive part 12 is preferably 3 Ω / □ or more and 1000 Ω / □ or less. If the surface resistance value of the first conductive part 12 is 3 Ω / □ or more, the optical performance is sufficient, and if the surface resistance value of the first conductive part 12 is 1000 Ω / □ or less, problems such as slow response speed can be suppressed, particularly in touch panel applications. It is more preferable that the surface resistance value of the first conductive portion 12 is 3Ω / □ or more and 100Ω / □ or less, 3Ω / □ or more and 70Ω / □ or less, 3Ω / □ or more and 60Ω / □ or less, 3Ω / □ or more and 50Ω / □ or less, 5Ω / □ or more and 1000Ω / □ or less, 5Ω / □ or more and 100Ω / □ or less, 5Ω / □ or more and 70Ω / □ or less, 5Ω / □ or more and 60Ω / □ or less, 5Ω / □ or more and 50Ω / □ or less, 10Ω / □ or more and 1000Ω / □ or less, 10Ω / □ or more and 100Ω / □ or less, 10Ω / □ or more and 70Ω / □ or less, 10Ω / □ or more and 60Ω / □ or less, or 10Ω / □ or more and 50Ω / □ or less.

[0082] When determining electrical continuity from the linear resistance value of the first conductive portion 12, if the linear resistance value of the first conductive portion 12 is at least less than 20,000 Ω, it can be determined that electrical continuity is obtained from the surface of the first conductive portion 12. The linear resistance value of the first conductive portion 12 is calculated as follows. First, the resistance value of a sample is measured in the same manner as the surface resistance value of the first conductive portion 12. Then, the linear resistance value of the first conductive portion 12 is calculated from the following equation (2). R L = R × C N …(2) In the above formula (2), R L is the wire resistance (Ω), R is the measured resistance (Ω), and C N is the number of conductive parts.

[0083] The linear resistance value of the first conductive part 12 is preferably 15,000 Ω or less. If the linear resistance value of the first conductive part 12 is 15,000 Ω or less, problems such as slow response speed can be suppressed, particularly in touch panel applications. The linear resistance value of the first conductive part 12 is more preferably 20 Ω or more and 15,000 Ω or less, 20 Ω or more and 12,000 Ω or less, 20 Ω or more and 8,000 Ω or less, 20 Ω or more and 1,000 Ω or less, 100 Ω or more and 15,000 Ω or less, 100 Ω or more and 12,000 Ω or less, 100 Ω or more and 8,000 Ω or less, 100 Ω or more and 1,000 Ω or less, 200 Ω or more and 15,000 Ω or less, 200 Ω or more and 12,000 Ω or less, 200 Ω or more and 8,000 Ω or less, or 200 Ω or more and 1,000 Ω or less.

[0084] The thickness T1 (see FIG. 2) of the first conductive part 12 is preferably 160 nm or more and 1.8 μm or less. If the thickness of the first conductive part 12 is 160 nm or more, it can cover the conductive fiber 18A, and if it is 1.8 μm or less, good flexibility can be obtained. From the viewpoint of reliably covering the conductive fibers 18A, the thickness of the first conductive portion 12 is more preferably 160 nm or more and 1.6 μm or less, 160 nm or more and 1.5 μm or less, 160 nm or more and 1.2 μm or less, 180 nm or more and 1.8 μm or less, 180 nm or more and 1.6 μm or less, 180 nm or more and 1.5 μm or less, 180 nm or more and 1.2 μm or less, 200 nm or more and 1.8 μm or less, 200 nm or more and 1.6 μm or less, 200 nm or more and 1.5 μm or less, 200 nm or more and 1.2 μm or less, 250 nm or more and 1.8 μm or less, 250 nm or more and 1.6 μm or less, 250 nm or more and 1.5 μm or less, or 250 nm or more and 1.2 μm or less.

[0085] The thickness of first conductive portion 12 means the maximum thickness from first surface 11A of substrate 11 to the surface of first conductive portion 12.

[0086] The thickness of the first conductive part 12 is determined by measuring the thickness at 10 random locations on a cross-sectional photograph of the first conductive part 12 taken using a scanning transmission electron microscope (STEM), a transmission electron microscope (TEM), or a scanning electron microscope (SEM), and calculating the arithmetic mean value of the thicknesses at 8 locations among the 10 measured locations, excluding the maximum and minimum values.

[0087] The specific method for taking cross-sectional photographs is described below. First, a sample for cross-sectional observation is prepared from the sensor using the same method as described above. Since the lack of electrical continuity in this sample can make STEM images difficult to see, it is preferable to sputter Pt-Pd for approximately 20 seconds. The sputtering time can be adjusted as needed, but caution is required because 10 seconds is too short and 100 seconds is too long, as the sputtered metal will appear as particulate foreign matter. Next, a cross-sectional photograph of the STEM sample is taken using a scanning transmission electron microscope (STEM) (e.g., the "S-4800 (TYPE 2)" manufactured by Hitachi High-Technologies Corporation). When taking this cross-sectional photograph, STEM observation is performed with the detector (selection signal) set to "TE," the accelerating voltage set to "30 kV," and the emission set to "10 μA." The magnification is adjusted between 5,000x and 200,000x, depending on the focus, contrast, and brightness, and whether each layer can be distinguished. The preferred magnification is 10,000 to 100,000, more preferably 10,000 to 50,000, and most preferably 25,000 to 50,000. When photographing a cross-section, the beam monitor aperture may be set to 3, the objective lens aperture to 3, and the working distance to 8 mm. When measuring the film thickness of the first conductive portion or the second conductive portion, it is important to be able to clearly observe the interfacial contrast between the conductive portion and other layers (such as the substrate or the embedding resin) as much as possible during cross-sectional observation. If the interface is difficult to see due to insufficient contrast, a pretreatment commonly used in electron microscope observations may be performed, such as forming a metal layer such as Pt-Pd, Pt, or Au on the surface of the conductive portion by sputtering. Staining treatments using osmium tetroxide, ruthenium tetroxide, or phosphotungstic acid may also be performed to make the interface between the organic layers more visible. The contrast of the interface may be difficult to see at high magnifications. In such cases, observations at low magnifications should also be performed simultaneously. For example, the specimen is observed at two magnifications, high and low, such as 25,000x and 50,000x, or 50,000x and 100,000x, and the arithmetic mean value is calculated at both magnifications. The average value is then used as the wire thickness value of the conductive part.

[0088] The first conductive portion 12 functions as, for example, an X-direction electrode in a projected capacitive touch panel. The first conductive portion 12 is provided within a rectangular active area, which is an area where a touch position can be detected.

[0089] As described above, the first conductive portion 12 has a plurality of first electrode portions 12A and a wiring portion 12B.

[0090] <First electrode part> The shape of first electrode portion 12A is not particularly limited and may be, for example, a square or diamond shape. Width W1 (electrode width) of first electrode portion 12A must be equal to or smaller than the contact area of ​​a finger (approximately 10 mmφ), and is therefore preferably equal to or smaller than 10 mm. Width W1 of first electrode portion 12A may be 0.35 mm to 10 mm, 0.35 mm to 9 mm, 0.35 mm to 8.5 mm, 0.35 mm to 8 mm, 0.5 mm to 10 mm, 0.5 mm to 9 mm, 0.5 mm to 8.5 mm, 0.5 mm to 8 mm, 0.7 mm to 10 mm, 0.7 mm to 9 mm, 0.7 mm to 8.5 mm, or 0.7 mm to 8 mm.

[0091] As shown in FIG. 2, the first electrode portion 12A includes a resin portion 17A and a plurality of conductive fibers 18A (first conductive fibers) arranged in the resin portion 17A. In this specification, the term "conductive fiber" refers to a material that is conductive and has a length that is sufficiently longer than its thickness (e.g., diameter), specifically, a length that is five times or more the thickness (an aspect ratio (length / thickness) of 5 or more). The resin portion 17A and a resin portion 17B described below are part of the resin layer 17 shown in FIG. 2. The first electrode portion 12A is formed into a desired shape, and therefore includes a conductive fiber pattern 12A1 (see FIG. 2) that is made up of a plurality of conductive fibers 18A and formed into the desired shape.

[0092] (resin) Resin portion 17A covers conductive fiber 18A. Covering conductive fiber 18A with resin portion 17A prevents conductive fiber 18A from detaching from first electrode portion 12A and second electrode portion 13A, and improves the durability and scratch resistance of first electrode portion 12A and second electrode portion 13A.

[0093] The thickness of resin portion 17A is the same as the thickness of first conductive portion 12, and therefore a description thereof will be omitted here.

[0094] The resin portion 17A is not particularly limited, but if the sensor is for optical use, it is preferably made of a resin having optical transparency.

[0095] The resin portion 17A may include a polymer (cured product, cross-linked product) of a polymerizable compound. The resin portion 17A may include a solvent-drying resin in addition to a polymer of a polymerizable compound. The polymerizable compound may include an ionizing radiation-polymerizable compound and / or a thermally polymerizable compound. Among these, the ionizing radiation-polymerizable compound is preferred as the polymerizable compound because of its fast curing rate and ease of design.

[0096] An ionizing radiation-polymerizable compound has at least one ionizing radiation-polymerizable functional group per molecule. In this specification, an "ionizing radiation-polymerizable functional group" refers to a functional group that can undergo a polymerization reaction upon exposure to ionizing radiation. Examples of the ionizing radiation-polymerizable functional group include ethylenically unsaturated groups such as (meth)acryloyl groups, vinyl groups, and allyl groups. The term "(meth)acryloyl group" encompasses both "acryloyl groups" and "methacryloyl groups." Examples of ionizing radiation used to polymerize an ionizing radiation-polymerizable compound include visible light, ultraviolet light, X-rays, electron beams, α-rays, β-rays, and γ-rays.

[0097] Examples of the ionizing radiation-polymerizable compound include an ionizing radiation-polymerizable monomer, an ionizing radiation-polymerizable oligomer, or an ionizing radiation-polymerizable prepolymer, which can be appropriately adjusted and used. As the ionizing radiation-polymerizable compound, a combination of an ionizing radiation-polymerizable monomer and an ionizing radiation-polymerizable oligomer or an ionizing radiation-polymerizable prepolymer is preferred.

[0098] Examples of ionizing radiation-polymerizable monomers include monomers containing a hydroxyl group, such as 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate, and (meth)acrylic acid esters, such as 2-ethylhexyl (meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, tetramethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and glycerol (meth)acrylate.

[0099] The ionizing radiation-polymerizable oligomer is preferably a polyfunctional oligomer having two or more functional groups, and more preferably a polyfunctional oligomer having three or more (trifunctional) ionizing radiation-polymerizable functional groups. Examples of the polyfunctional oligomer include polyester (meth)acrylate, urethane (meth)acrylate, polyester-urethane (meth)acrylate, polyether (meth)acrylate, polyol (meth)acrylate, melamine (meth)acrylate, isocyanurate (meth)acrylate, and epoxy (meth)acrylate.

[0100] The ionizing radiation polymerizable prepolymer has a weight-average molecular weight of 10,000 or more, preferably 10,000 to 80,000, and more preferably 10,000 to 40,000. If the weight-average molecular weight exceeds 80,000, the viscosity will be high, which will reduce the coating suitability and may result in a poor appearance of the resulting light-transmitting resin. Examples of multifunctional prepolymers include urethane (meth)acrylate, isocyanurate (meth)acrylate, polyester-urethane (meth)acrylate, and epoxy (meth)acrylate.

[0101] A thermally polymerizable compound has at least one thermally polymerizable functional group per molecule. In this specification, a "thermally polymerizable functional group" refers to a functional group that can undergo a polymerization reaction with other functional groups or with other functional groups upon heating. Examples of the thermally polymerizable functional group include a hydroxyl group, a carboxyl group, an isocyanate group, an amino group, a cyclic ether group, and a mercapto group.

[0102] The thermally polymerizable compound is not particularly limited, and examples thereof include epoxy compounds, polyol compounds, isocyanate compounds, melamine compounds, urea compounds, and phenol compounds.

[0103] The solvent-drying resin is a resin, such as a thermoplastic resin, that can be formed into a coating simply by drying the solvent added to adjust the solid content during coating. When a solvent-drying resin is added, coating defects on the surface to which the coating liquid is applied can be effectively prevented when forming the electrical insulation layer 14. There are no particular restrictions on the solvent-drying resin, and generally, a thermoplastic resin can be used.

[0104] Examples of thermoplastic resins include styrene-based resins, (meth)acrylic-based resins, vinyl acetate-based resins, vinyl ether-based resins, halogen-containing resins, alicyclic olefin-based resins, polycarbonate-based resins, polyester-based resins, polyamide-based resins, cellulose derivatives, silicone-based resins, and rubber or elastomers.

[0105] The thermoplastic resin is preferably amorphous and soluble in an organic solvent (particularly a common solvent capable of dissolving multiple polymers and curable compounds). In particular, from the viewpoints of transparency and weather resistance, styrene-based resins, (meth)acrylic-based resins, alicyclic olefin-based resins, polyester-based resins, cellulose derivatives (cellulose esters, etc.), etc. are preferred.

[0106] The resin portion 17A can be formed by using a curable resin composition containing a polymerizable compound, etc. The resin composition contains the polymerizable compound, etc., and may also contain a solvent or a polymerization initiator as needed. Furthermore, the resin composition may contain conventionally known dispersants, surfactants, silane coupling agents, thickeners, color inhibitors, colorants (pigments, dyes), antifoaming agents, flame retardants, UV absorbers, adhesion promoters, polymerization inhibitors, antioxidants, surface modifiers, lubricants, etc., depending on the purpose of increasing the hardness of the resin, suppressing cure shrinkage, or controlling the refractive index.

[0107] Examples of the solvent include alcohols (methanol, ethanol, propanol, isopropanol, n-butanol, s-butanol, t-butanol, benzyl alcohol, PGME, ethylene glycol, etc.), ketones (acetone, methyl ethyl ketone (MEK), cyclohexanone, methyl isobutyl ketone, diacetone alcohol, cycloheptanone, diethyl ketone, etc.), ethers (1,4-dioxane, dioxolane, diisopropyl ether dioxane, tetrahydrofuran, etc.), aliphatic hydrocarbons ( hexane, etc.), alicyclic hydrocarbons (cyclohexane, etc.), aromatic hydrocarbons (toluene, xylene, etc.), halogenated carbons (dichloromethane, dichloroethane, etc.), esters (methyl formate, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, ethyl lactate, etc.), cellosolves (methyl cellosolve, ethyl cellosolve, butyl cellosolve, etc.), cellosolve acetates, sulfoxides (dimethyl sulfoxide, etc.), amides (dimethylformamide, dimethylacetamide, etc.), or mixtures thereof.

[0108] A polymerization initiator is a component that is decomposed by light or heat to generate radicals or ionic species, thereby initiating or progressing the polymerization (crosslinking) of a polymerizable compound. Examples of the polymerization initiator used in the resin composition include photopolymerization initiators (e.g., photoradical polymerization initiators, photocationic polymerization initiators, and photoanionic polymerization initiators), thermal polymerization initiators (e.g., thermal radical polymerization initiators, thermal cationic polymerization initiators, and thermal anionic polymerization initiators), and mixtures thereof.

[0109] As described above, when sensor 10 is used for flexible applications, it is important that resin 17 adheres closely to substrate 11 and follows the substrate 11 when folded. In order to form resin 17 that adheres closely to substrate 11 and can follow the substrate 11 when folded, it is preferable to use an oxime ester compound as a polymerization initiator. Examples of commercially available oxime ester compounds include IRGACURE (registered trademark) OXE01, IRGACURE (registered trademark) OXE02, and IRGACURE (registered trademark) OXE03 (all manufactured by BASF Japan Ltd.).

[0110] (Conductive fiber) A plurality of conductive fibers 18A are present in resin portion 17A. Since first electrode portion 12A is electrically conductive, conductive fibers 18A are in contact with each other in the thickness direction of first electrode portion 12A.

[0111] In the first electrode portion 12A, it is preferable that the conductive fibers 18A contact each other to form a network structure (mesh structure) in the planar direction (two-dimensional direction) of the first electrode portion 12A. The conductive fibers 18A form a network structure, which allows the formation of conductive paths.

[0112] The thicker the conductive fibers, the greater the overlapping areas between them, making it possible to achieve a low linear resistance value. However, excessive overlapping of the conductive fibers can increase costs and make it difficult to maintain a low haze value. For this reason, the thickness of the conductive fibers 18A is preferably 300 nm or less. As long as a low linear resistance value can be maintained, a thinner first conductive portion is preferable from the perspective of optical properties and thinning. From the perspectives of thinning and obtaining good optical properties such as a low haze value, the thickness of the conductive fibers 18A is more preferably 10 nm to 200 nm, 10 nm to 145 nm, 10 nm to 140 nm, 10 nm to 120 nm, 10 nm to 110 nm, 10 nm to 80 nm, or 10 nm to 50 nm. A thickness of the conductive fibers 18A of 10 nm or more ensures stable electrical conduction. To obtain more stable electrical conduction, it is desirable that two or more conductive fibers overlap and contact each other, so the lower limit of the thickness of the conductive fiber 18A is more preferably 20 nm to 200 nm, 20 nm to 145 nm, 20 nm to 140 nm, 20 nm to 120 nm, 20 nm to 110 nm, 20 nm to 80 nm, 20 nm to 50 nm, 30 nm to 200 nm, 30 nm to 145 nm, 30 nm to 140 nm, 30 nm to 120 nm, 30 nm to 110 nm, 30 nm to 80 nm, or 30 nm to 50 nm. Note that, to obtain flexibility, if the spacing φ is large and the number of folding times is about 100,000, a stable linear resistance value can be obtained if the thickness of the conductive fiber 18A is 300 nm or less. Furthermore, when the spacing φ becomes small and the number of folding times exceeds 100,000, it is preferable that the thickness of the conductive fiber 18A is thin, for example, 10 nm or more and 200 nm or less, 10 nm or more and 145 nm or less, 10 nm or more and 120 nm or less, 20 nm or more and 200 nm or less, 20 nm or more and 145 nm or less, 20 nm or more and 120 nm or less, 30 nm or more and 200 nm or less, 30 nm or more and 145 nm or less, or 30 nm or more and 120 nm or less.

[0113] When measuring the average fiber diameter of the conductive fibers 18A using the sensor 10, the average fiber diameter of the conductive fibers 18A is preferably 30 nm or less. If the average fiber diameter of the conductive fibers 18A is 30 nm or less, an increase in the haze value of the sensor 10 can be suppressed and sufficient light transmission performance can be achieved. From the viewpoint of the conductivity of the first electrode portion 12A, the average fiber diameter of the conductive fibers 18A is more preferably 5 nm to 28 nm, 5 nm to 25 nm, 5 nm to 20 nm, 7 nm to 28 nm, 7 nm to 25 nm, 7 nm to 20 nm, 10 nm to 28 nm, 10 nm to 25 nm, or 10 nm to 20 nm. Among these, a more preferred range for the fiber diameter of the conductive fibers 18A is 7 nm to 25 nm in order to control the balance between the resistance value and the haze value within a preferred range.

[0114] When measuring the average fiber diameter of the conductive fibers 18A using the sensor 10, a scanning transmission electron microscope (STEM, product name "S-4800," manufactured by Hitachi High-Technologies Corporation) is used to photograph the cross section of the first electrode portion. Ten conductive fibers 18A are observed in the cross-sectional image, and the shortest diameter (minor diameter) of each conductive fiber 18A is measured. The three smallest data points are selected from the ten data points, and the arithmetic mean value calculated from the three data points is used as the average fiber diameter of the conductive fibers 18A. The specific method for photographing the cross section is described below. First, a sample measuring 1 mm x 10 mm is cut from the sensor to include the first electrode portion. This sample is then placed in a silicone-based embedding plate, and epoxy-based resin is poured in to embed the entire sample in the resin. The embedding resin is then left to harden at 25°C for at least 12 hours. Then, an ultrathin section was prepared using an ultramicrotome (product name "Ultramicrotome EM UC7" manufactured by Leica Microsystems) with a feed thickness set to 100 nm. The prepared ultrathin section was then collected using a collodion-coated mesh (150) to serve as a STEM sample. A cross-sectional photograph of the STEM sample was then taken using a scanning transmission electron microscope (STEM) (product name "S-4800 (TYPE 2)" manufactured by Hitachi High-Technologies Corporation). When taking this cross-sectional photograph, the detector (selection signal) was set to "TE," the acceleration voltage was set to 30 kV, and the emission was set to "10 μA." The magnification was adjusted appropriately between 5,000x and 200,000x while adjusting the focus and observing the contrast and brightness to see if each layer could be distinguished. The preferred magnification is 10,000x to 50,000x, and more preferably 25,000x to 40,000x. If the magnification is too high, the pixels at the interface become coarse and difficult to see, so it is best not to increase the magnification too much when measuring the fiber diameter.When taking cross-sectional photographs, the beam monitor aperture should also be set to 3, the objective lens aperture to 3, and the WD to 8 mm.

[0115] As will be described later, the first electrode unit 12A is formed using a conductive fiber dispersion containing the conductive fibers 18A, and the average fiber diameter of the conductive fibers 18A can also be measured using the conductive fiber dispersion. When measuring the average fiber diameter of the conductive fibers 18A in the conductive fiber dispersion, the preferred range of the average fiber diameter of the conductive fibers 18A is the same as the preferred range of the average fiber diameter of the conductive fibers 18A when measuring the average fiber diameter of the conductive fibers 18A using the sensor 10.

[0116] An example of measuring the average fiber diameter of the conductive fibers 18A using a conductive dispersion will be described below. For example, a transmission electron microscope (TEM) (e.g., product name "H-7650" manufactured by Hitachi High-Technologies Corporation) is used to capture 50 images at 100,000 to 200,000 magnifications. The fiber diameters of 100 conductive fibers are measured on the image screen using the software provided with the TEM, and the arithmetic mean value is calculated. When measuring the fiber diameter using the H-7650, the acceleration voltage is set to "100 kV," the emission current to "10 μA," the focusing lens aperture to "1," the objective lens aperture to "0," the observation mode to "HC," and the spot to "2." Alternatively, the fiber diameter of the conductive fibers can also be measured using a scanning transmission electron microscope (STEM) (e.g., product name "S-4800 (TYPE 2)" manufactured by Hitachi High-Technologies Corporation). When using a STEM, 50 images are taken at 100,000 to 200,000 magnifications, and the fiber diameters of 100 conductive fibers are measured on the imaging screen using the software provided with the STEM. The average fiber diameter of the conductive fibers is calculated as the arithmetic mean value. When measuring fiber diameter using the S-4800 (TYPE 2) mentioned above, the signal selection is set to "TE," the acceleration voltage to "30 kV," the emission current to "10 μA," the probe current to "Norm," the focus mode to "UHR," the condenser lens 1 to "5.0," the working distance to "8 mm," and the tilt to "0°."

[0117] When measuring the fiber diameter of conductive fiber 18A using a conductive dispersion, a measurement sample prepared by the following method is used. Because TEM measurement requires high magnification, it is important to minimize the concentration of the conductive fiber dispersion to minimize overlap of the conductive fibers. Specifically, the conductive fiber dispersion is preferably diluted with water or alcohol to a conductive fiber concentration of 0.05% by mass or less, or to a solids content of 0.2% by mass or less, depending on the dispersion medium. A drop of this diluted conductive fiber dispersion is then placed on a grid mesh with a carbon support film for TEM or STEM observation, dried at room temperature, and observed under the above conditions to obtain image data. The arithmetic mean value is calculated based on this data. A Cu grid with a carbon support film, model number "#10-1012 Elastic Carbon ELS-C10 STEM Cu100P Grid Specification," is preferred as the grid mesh with a carbon support film. Its high electron beam radiation resistance and electron beam transmittance, better than that of plastic support films, make it suitable for high magnification and are resistant to organic solvents. Furthermore, when dripping, it is recommended to place the grid mesh on a glass slide, as the grid mesh alone is too small to drip easily.

[0118] The fiber diameter can be determined by actual measurement based on a photograph, or it can be calculated by binarizing image data. When measuring, the photograph can be printed and enlarged as needed. In this case, the conductive fibers will appear darker than the other components. Measurements are taken with the outside of the outline as the starting and ending points. The conductive fiber concentration is determined as the ratio of the mass of the conductive fibers to the total mass of the conductive fiber dispersion, and the solid content is determined as the ratio of the mass of components other than the dispersion medium (conductive fibers, resin components, and other additives) to the total mass of the conductive fiber dispersion. The fiber diameter determined using the conductive fiber dispersion and the fiber diameter determined by actual measurement based on a photograph are approximately the same value.

[0119] The average fiber length of the conductive fibers 18A can be measured using a conductive fiber dispersion. When measuring the average fiber length of the conductive fibers 18A using a conductive fiber dispersion, the average fiber length of the conductive fibers 18A is preferably 15 μm or more and 20 μm or less to suppress cloudiness. If the average fiber length of the conductive fibers 18A is 15 μm or more, a first electrode portion with sufficient conductive performance can be formed, and there is no risk of cloudiness due to aggregation, an increase in haze value, or a decrease in light transmittance. Furthermore, if the average fiber length of the conductive fibers 18A is 20 μm or less, coating can be performed without clogging the filter. The average fiber length of the conductive fibers 18A may be 5 μm or more and 40 μm or less, 5 μm or more and 35 μm or less, 5 μm or more and 30 μm or less, 5 μm or more and 20 μm or less, 7 μm or more and 40 μm or less, 7 μm or more and 35 μm or less, 7 μm or more and 30 μm or less, 7 μm or more and 20 μm or less, 10 μm or more and 40 μm or less, 10 μm or more and 35 μm or less, 10 μm or more and 30 μm or less, 10 μm or more and 20 μm or less, 15 μm or more and 40 μm or less, 15 μm or more and 35 μm or less, or 15 μm or more and 30 μm or less.

[0120] The following describes an example of measuring the average fiber length of conductive fiber 18A using a conductive dispersion. For example, using the SEM function of a scanning electron microscope (SEM) (e.g., product name "S-4800 (TYPE 2)" manufactured by Hitachi High-Technologies Corporation), 10 images are taken at 5-20 million magnifications. The fiber lengths of 100 conductive fibers are measured on the image screen using the accompanying software. The fiber length is then calculated as the arithmetic mean of the fiber lengths of 98 conductive fibers, excluding the maximum and minimum values. When measuring fiber length using the S-4800 (TYPE 2) described above, a sample stage is used, tilted at 45°, and the settings are as follows: signal selection is set to "SE," acceleration voltage is set to "3 kV," emission current is set to "10 μA to 20 μA," SE detector is set to "mixed," probe current is set to "Norm," focus mode is set to "UHR," condenser lens 1 is set to "5.0," WD is set to "8 mm," and tilt is set to "30°." The TE detector is not used during SEM observation, so be sure to remove it beforehand. The S-4800 can be used to select between STEM and SEM functions, but the SEM function is used when measuring the fiber length.

[0121] When measuring the fiber length of the conductive fiber 18A using the conductive dispersion, a measurement sample prepared by the following method is used: First, the conductive fiber dispersion is applied to the untreated surface of a B5-sized polyethylene terephthalate (PET) film having a thickness of 50 μm, with the conductive fiber applied in an amount of 10 mg / m 2 The dispersion medium is then dried, and conductive fibers are placed on the surface of the PET film to produce a sensor. A 10mm x 10mm piece is cut out from the center of this sensor. This cut sensor is then attached flat to the surface of a 45° inclined SEM sample stage (model number "728-45", manufactured by Nissin EM Co., Ltd., inclined sample stage 45°, φ15mm x 10mm, M4 aluminum) using silver paste. Pt-Pd is then sputtered for 20-30 seconds to ensure conductivity. Images may be difficult to see without an adequate sputtered film, so adjust accordingly.

[0122] The fiber length can be determined by measuring the fiber based on a photograph, or it can be calculated by binarizing the image data. When measuring the fiber based on a photograph, the same method as above should be used. The fiber length determined using a conductive fiber dispersion and the fiber length determined by measuring the fiber based on a photograph are approximately the same value.

[0123] The conductive fibers 18A are preferably at least one type of fiber selected from the group consisting of conductive carbon fibers, metal fibers such as metal nanowires, metal-coated organic fibers, metal-coated inorganic fibers, and carbon nanotubes. The conductive fibers 18A are not subjected to a blackening treatment that suppresses metallic luster.

[0124] Examples of the conductive carbon fibers include vapor grown carbon fibers (VGCF), carbon nanotubes, wire cups, wire walls, etc. These conductive carbon fibers can be used alone or in combination of two or more.

[0125] The metal fibers are preferably metal nanowires made of, for example, stainless steel, Ag, Cu, Au, Al, Rh, Ir, Co, Zn, Ni, In, Fe, Pd, Pt, Sn, Ti, or alloys thereof. Among metal nanowires, silver nanowires are preferred because they can achieve low resistance, are resistant to oxidation, and are suitable for wet coating. The metal fibers can be, for example, fibers produced by wire drawing or cutting, which stretch the metals into thin, long fibers. One or more types of such metal fibers can be used.

[0126] When silver nanowires are used as metal fibers, they can be synthesized by liquid-phase reduction of a silver salt (e.g., silver nitrate) in the presence of a polyol (e.g., ethylene glycol) and poly(vinylpyrrolidone). Mass production of uniformly sized silver nanowires can be achieved, for example, by methods described in Xia, Y. et al., Chem. Mater. (2002), 14, 4736-4745 and Xia, Y. et al., Nanoletters (2003) 3(7), 955-960.

[0127] There are no particular limitations on the means for producing metal nanowires, and known means such as liquid-phase methods and vapor-phase methods can be used. Furthermore, there are no particular limitations on the specific production method, and known production methods can be used. For example, reference can be made to Adv. Mater., 2002, 14, 833-837; Chem. Mater., 2002, 14, 4736-4745, etc., for methods for producing silver nanowires, Japanese Patent Application Laid-Open No. 2006-233252, etc., for methods for producing gold nanowires, Japanese Patent Application Laid-Open No. 2002-266007, etc., for methods for producing Cu nanowires, and Japanese Patent Application Laid-Open No. 2004-149871, etc., for methods for producing cobalt nanowires.

[0128] Examples of the metal-coated synthetic fibers include acrylic fibers coated with gold, silver, aluminum, nickel, titanium, etc. One or more types of such metal-coated synthetic fibers can be used.

[0129] <Wiring section> The wiring portion 12B also extends along the first direction DR1 (see FIG. 1). As shown in FIG. 3, the wiring portion 12B includes conductive fibers 18A, similar to the first electrode portion 12A. However, if metal nanowires are used as the conductive fibers 18A, there is a risk that the metal nanowires may break due to the concentration of static electricity. To prevent such breakage, the width W2 (neck width) of the wiring portion 12B is preferably 0.35 mm or more. From the viewpoint of further suppressing the above-mentioned disconnection and ensuring the area of ​​the first electrode portion 12A, it is preferable that the width W2 of the wiring portion 12B be 0.35 mm or more and 5.0 mm or less, 0.35 mm or more and 4.5 mm or less, 0.35 mm or more and 4.0 mm or less, 0.4 mm or more and 5.0 mm or less, 0.4 mm or more and 4.5 mm or less, 0.4 mm or more and 4.0 mm or less, 0.45 mm or more and 5.0 mm or less, 0.45 mm or more and 4.5 mm or less, 0.45 mm or more and 4.0 mm or less, 0.5 mm or more and 5.0 mm or less, 0.5 mm or more and 4.5 mm or less, or 0.5 mm or more and 4.0 mm or less.

[0130] From the viewpoint of ensuring the area of ​​the first electrode portion 12A, the width W2 of the wiring portion 12B is preferably equal to or less than ½ of the width W1 (electrode width) of the first electrode portion 12A. From the viewpoint of further ensuring the area of ​​the first electrode portion 12A, the upper limit of the width W2 of the wiring portion 12B is preferably equal to or less than ⅓ or ¼ of the width W1 of the first electrode portion 12A.

[0131] The wiring portion 12B includes a constituent material of the electrical insulating layer 14 (e.g., resin) and a plurality of conductive fibers 18A disposed in the constituent material of the electrical insulating layer 14. Furthermore, since the wiring portion 12B extends along the first direction DR1, the wiring portion 12B includes a conductive fiber pattern 12B1 (see FIG. 3) made of a plurality of conductive fibers 18A and extending along the first direction DR1. The constituent material of the electrical insulating layer 14 will be described in the section on the electrical insulating layer 14, and therefore will not be described here. Furthermore, since the conductive fibers 18A were described in the section on the first electrode portion 12A, their description will be omitted.

[0132] The absolute value of the difference in refractive index between the wiring portion 12B and the substrate 11 (|refractive index of wiring portion 12B - refractive index of substrate 11|) and the absolute value of the difference in refractive index between the wiring portion 12B and the electrical insulating layer 14 (|refractive index of wiring portion 12B - refractive index of electrical insulating layer 14|) are preferably 0.08 or less. That is, the refractive index of the wiring portion 12B is almost the same as the refractive index of the substrate 11 and the refractive index of the electrical insulating layer 14. This is because the wiring portion 12B contains conductive fibers 18A, and therefore the influence of the conductive fibers 18A is not taken into account when determining the refractive index of the wiring portion 12B. The refractive index of the wiring portion 12B is determined by the refractive index of the material of the electrical insulating layer 14 that is embedded in the wiring portion 12B. This makes it possible to suppress interfacial reflection between the wiring portion 12B and the substrate 11 and between the wiring portion 12B and the electrical insulating layer 14, thereby preventing the wiring portion 12B from being visible. The difference in refractive index between the wiring portion 12B and the substrate 11, and the difference in refractive index between the wiring portion 12B and the electrical insulating layer 14 are more preferably 0.07 or less, 0.06 or less, or 0.05 or less, respectively.

[0133] <<Second conductive part>> The second conductive portion 13 is an electrically conductive portion. The surface resistance, line resistance, and thickness T2 (see FIG. 3) of the second conductive portion 13 are the same as the surface resistance, line resistance, and thickness T1 of the first electrode portion 12A, and therefore, description thereof will be omitted.

[0134] The second conductive portion 13 functions as, for example, an electrode in the Y direction in a projected capacitive touch panel. The second conductive portion 13 is provided within a rectangular active area, which is an area where a touch position can be detected.

[0135] As described above, the second conductive portion 13 has a plurality of second electrode portions 13A and a bridge wiring portion 13B.

[0136] <Second electrode section> The shape of second electrode portion 13A is not particularly limited and may be, for example, a square or diamond shape. Width W3 (electrode width) of second electrode portion 13A must be equal to or smaller than the contact area of ​​a finger (approximately 10 mmφ), and is therefore preferably equal to or smaller than 10 mm. Width W3 of second electrode portion 13A may be 0.35 mm to 10 mm, 0.35 mm to 9 mm, 0.35 mm to 8.5 mm, 0.35 mm to 8 mm, 0.5 mm to 10 mm, 0.5 mm to 9 mm, 0.5 mm to 8.5 mm, 0.5 mm to 8 mm, 0.7 mm to 10 mm, 0.7 mm to 9 mm, 0.7 mm to 8.5 mm, or 0.7 mm to 8 mm.

[0137] As shown in Fig. 3, the second electrode portion 13A includes a resin portion 17A and a plurality of conductive fibers 18A arranged in the resin portion 17A. Furthermore, since the second electrode portion 13A is formed in a predetermined shape, the second electrode portion 13A includes a conductive fiber pattern 13A1 (second conductive fiber pattern, see Fig. 3) that is made up of a plurality of conductive fibers 18A and formed in a desired shape. The resin portion 17A and the conductive fibers 18A were explained in the section for the first electrode portion 12A, and therefore further explanation will be omitted.

[0138] <Bridge wiring section> The bridge wiring portion 13B also extends along the second direction DR2 (see FIG. 1). The bridge wiring portion 13B includes a resin portion 17B and conductive fibers 18B (second conductive fibers) arranged in the resin portion 17B. The resin portion 17B is similar to the resin portion 17A, and the conductive fibers 18B are similar to the conductive fibers 18A, so their description will be omitted. Furthermore, since the bridge wiring portion 13B extends along the second direction DR2, the bridge wiring portion 13B includes a conductive fiber pattern 13B1 (see FIG. 3) made of a plurality of conductive fibers 18B and extending along the second direction DR2.

[0139] For the same reasons as those described for wiring portion 12B, width W4 (neck width) of bridge wiring portion 13B is preferably 0.35 mm or more. From the viewpoint of further suppressing the above-mentioned disconnection and ensuring the area of ​​second electrode portion 13A, width W4 of bridge wiring portion 13B is preferably 0.35 mm to 5.0 mm, 0.35 mm to 4.5 mm, 0.35 mm to 4.0 mm, 0.4 mm to 5.0 mm, 0.4 mm to 4.5 mm, 0.4 mm to 4.0 mm, 0.45 mm to 5.0 mm, 0.45 mm to 4.5 mm, 0.45 mm to 4.0 mm, 0.5 mm to 5.0 mm, 0.5 mm to 4.5 mm, or 0.5 mm to 4.0 mm.

[0140] From the viewpoint of ensuring the area of ​​the second electrode portion 13A, the width W4 of the bridge wiring portion 13B is preferably equal to or less than ½ of the width W3 (electrode width) of the second electrode portion 13A. From the viewpoint of further ensuring the area of ​​the second electrode portion 13A, the upper limit of the width W4 of the bridge wiring portion 13B is preferably equal to or less than ⅓ or ¼ of the width W3 of the second electrode portion 13A.

[0141] The thickness T3 of the bridge wiring portion 13B (see FIG. 3) is preferably 0.16 μm or more and 1.8 μm or less. If the thickness of the bridge wiring portion 13B is 0.16 μm or more, reliability can be improved by covering the conductive fibers 18B with the resin 17B, and if the thickness is 1.8 μm or less, flexibility can be ensured. The thickness T3 of the bridge wiring portion 13B is more preferably 0.2 μm or more and 1.6 μm or less, 0.2 μm or more and 1.4 μm or less, 0.2 μm or more and 1.2 μm or less, 0.3 μm or more and 1.6 μm or less, 0.3 μm or more and 1.4 μm or less, 0.3 μm or more and 1.2 μm or less, 0.5 μm or more and 1.6 μm or less, 0.5 μm or more and 1.4 μm or less, or 0.5 μm or more and 1.2 μm or less. In the case of FIG. 3, the thickness of the bridge wiring portion 13B means the distance from the upper surface 14A1 of the electrical insulating layer 14 to the surface of the resin portion 17B.

[0142] The bridge wiring portion 13B preferably contains the same type of conductive material as the conductive material contained in the second electrode portion 13A. For example, since the second electrode portion 13A contains conductive fibers, the bridge wiring portion 13B preferably also contains conductive fibers. In this specification, "same type" means that the type is the same, and does not necessarily mean that the length or diameter is the same.

[0143] The mass concentration of the conductive fibers measured in a 1 cm square sample including the bridge wiring portion 13B and centered on the bridge wiring portion 13B is preferably less than 10 wt%. The conductive fibers used to measure the mass concentration may include conductive fibers 18B in the bridge wiring portion 13B as well as conductive fibers in portions other than the bridge wiring portion 13B. The mass concentration of the conductive fibers can be determined by removing organic matter, such as the resin portion 17B, contained in the bridge wiring portion 13B using a dry ashing method, and then calculating the ratio of the masses before and after organic matter removal. If the mass concentration of the conductive fibers is less than 10 wt%, the bridge wiring portion 13B is composed almost entirely of the resin portion 17B, and therefore the refractive index of the bridge wiring portion is almost the same as the refractive index of the resin portion 17B, making the conductive fibers 18B less visible. From the viewpoint of ensuring conductivity of the bridge wiring portion 13B and making the bridge wiring portion 13B less visible, it is preferable that the mass concentration of this conductive fiber be 0.2 wt% to 40 wt%, 0.2 wt% to 30 wt%, 0.2 wt% to 20 wt%, 0.2 wt% to 15 wt%, 0.5 wt% to 40 wt%, 0.5 wt% to 30 wt%, 0.5 wt% to 20 wt%, 0.5 wt% to 15 wt%, 1 wt% to 40 wt%, 1 wt% to 30 wt%, 1 wt% to 20 wt%, or 1 wt% to 15 wt%.

[0144] In the bridge wiring section 13B, as shown in FIG. 3, it is preferable that the conductive fibers 18B are unevenly distributed toward the substrate 11 from the position HL, which is halfway through the thickness of the bridge wiring section 13B (resin section 17B). Since the conductive fibers 18B are unevenly distributed toward the substrate 11, the amount of conductive fibers 18B present on the surface side of the bridge wiring section 13B is reduced. Therefore, the surface of the bridge wiring section 13B is almost entirely made up of the resin section 17B, making the bridge wiring section 13B less visible. Whether the conductive fibers 18B are unevenly distributed toward the substrate 11 from the position HL, which is halfway through the thickness of the bridge wiring section 13B, can be determined as follows: First, a sample for cross-sectional observation is prepared from the sensor. Specifically, a 2 mm × 5 mm sample is cut from the sensor so as to include the bridge wiring section. The cut sample is then placed in a silicone-based embedding plate, and epoxy-based resin is poured into it to embed the entire sample in the resin. The embedding resin is then left to harden at 65°C for at least 12 hours. Next, an ultrathin section is prepared using an ultramicrotome (product name "Ultramicrotome EM UC7" manufactured by Leica Microsystems) with a feed thickness set to 100 nm. The prepared ultrathin section is then collected using a collodion-coated mesh (150) to serve as a STEM sample. Since STEM images may be difficult to see if conductivity is not achieved in this sample, it is preferable to sputter Pt-Pd for approximately 20 seconds. The sputtering time can be adjusted as needed, but care must be taken because 10 seconds is too short and 100 seconds is too long, as the sputtered metal will appear as particulate foreign matter. Then, a scanning transmission electron microscope (STEM) (product name "S-4800 (TYPE2)" manufactured by Hitachi High-Technologies Corporation) is used to take cross-sectional photographs of the conductive portion of the STEM sample. When taking this cross-sectional photograph, the detector (selection signal) is set to "TE," the acceleration voltage is set to 30 kV, and the emission is set to "10 μA." The magnification for STEM observation is adjusted to 5,000 to 200,000 times, and the contrast and brightness are appropriately adjusted so that each layer can be distinguished. The preferred magnification is 10,000 to 100,000 times, more preferably 10,000 to 50,000 times, and most preferably 25,000 to 50,000 times.When taking the cross-sectional photographs, the aperture may be set to 3 for the beam monitor, 3 for the objective lens, and 8 mm for the working distance. Ten cross-sectional photographs taken in this manner are then prepared. After taking the cross-sectional photographs of the bridge wiring section, the position at half the thickness of the bridge wiring section is determined in each cross-sectional photograph. It is then determined whether the conductive fibers appearing in the cross-sectional photograph are located closer to the substrate than this half-thickness position. Specifically, in the cross-sectional photograph of the bridge wiring section taken with the electron microscope, the conductive fibers appear in a darker color (e.g., black) than the resin section, making it possible to confirm the conductive fibers in the cross-sectional photograph of the bridge wiring section. Meanwhile, when the cross-sectional photograph is enlarged, pixels appear. Since the pixels are the same size and arranged in a grid (lattice), the number of pixels displaying the conductive fibers located closer to the substrate than the half-thickness position and the number of pixels displaying the conductive fibers located closer to the surface of the bridge wiring section than the half-thickness position are counted in each cross-sectional photograph, and the ratio of the number of pixels displaying the conductive fibers located closer to the substrate than the half-thickness position to the total number of pixels displaying the conductive fibers is calculated. Here, when a pixel displaying conductive fibers spans the halfway point, each pixel is divided into a portion located closer to the substrate than the halfway point and a portion located closer to the surface of the bridge wiring portion than this position, and each pixel is divided based on the area ratio of the divided portions. The above percentage determined from the cross-sectional photograph is then taken as the proportion of conductive fibers located closer to the substrate than the halfway point in the thickness of the bridge wiring portion. If this proportion is 55% or more, it is determined that the conductive fibers are unevenly distributed closer to the substrate than the halfway point in the thickness of the bridge wiring portion. This proportion is taken as the arithmetic mean of the proportions determined from each cross-sectional photograph. Note that when the surface resistance is low, conductive fibers are uniformly distributed throughout the bridge wiring portion, so even if the proportion of conductive fibers is determined using a cross-sectional photograph of only a portion of the bridge wiring portion, it is considered to represent the proportion of conductive fibers in the entire bridge wiring portion. The proportion of conductive fibers located closer to the substrate than the halfway point in the thickness of the bridge wiring portion determined from the cross-sectional photograph is more preferably 70% or more, and even more preferably 80% or more.

[0145] Whether the conductive fibers 18B are unevenly distributed toward the substrate 11 from the half-thickness position HL of the bridge wiring portion 13B can also be determined as follows. First, a first sample is prepared in which a metal layer, such as Pt-Pd, Pt, or Au, is formed on the surface of the bridge wiring portion of the sensor by sputtering, and a second sample is prepared in which no metal layer is formed on the surface of the sensor. The thickness of the bridge wiring portion 13B is measured using the first sample, as described below. Furthermore, a cross-sectional photograph of the conductive portion of the second sample is taken using the method described above. The cross-sectional photograph data is then imported into image analysis and measurement software (product name "WinROOF Version 7.4" by Mitani Corporation) and binarized. STEM observation creates contrast by using differences in electron beam penetration. High-density metals are difficult for electron beams to penetrate, so they appear black, while organic materials with lower densities than metals appear white. Therefore, the black areas in the data can be identified as conductive fibers, and the white to gray areas that are not black can be identified as resin. Therefore, if the proportion of the black portion in the region closer to the substrate than the halfway point of the bridge wiring portion is greater than the proportion of the black portion in the region closer to the surface of the bridge wiring portion than the halfway point, it can be determined that the conductive fibers 18B are unevenly distributed on the substrate 11 side of the halfway point HL of the bridge wiring portion 13B. The black portion can be extracted based on brightness. Furthermore, the area can be measured only by automatic area measurement because the contrast between metals and organic materials is clearly different.

[0146] The area measurement using the binarization process is performed using the following procedure. First, the cross-sectional image is loaded into the software and opened in the software's image window. Then, within the image window, the ROI (processing area) to be processed is selected, with the bottom and top sections selected. Each section is binarized to calculate the total area of ​​the conductive fiber. The processing area is set by selecting the "Draw Rectangle ROI" button on the image toolbar and drawing a rectangular ROI within the image window. The software outputs measurement values ​​in pixel units, but calibration can be used to convert the measurement values ​​to actual length. When calculating area ratios, conversion to actual length is not necessary to determine whether the conductive fibers are unevenly distributed toward the substrate. However, calibration is required to visualize the surface resistance, haze, and fiber distribution in the conductive film. The STEM image has a scale display, which can be used to calibrate the ROI area. Specifically, from the image toolbar, use the Line ROI button to draw a line the length of the STEM image scale. Then, the calibration dialog box is displayed, the selected line is checked, and the length and units corresponding to the STEM image scale are set. The binarization process separates the area of ​​the conductive fiber to be measured from the rest of the image. Specifically, select "Binarization using two thresholds" from the binarization menu. Because conductive fibers appear dark and black, while other areas appear white to gray, enter the appropriate density (brightness) thresholds (e.g., 0 and 80) to perform binarization using these two thresholds. If the conductive fibers in the actual STEM image do not match the conductive fibers in the binarized image, which are displayed in two colors (e.g., conductive fibers appear green) due to the threshold, change the threshold value as appropriate to correct the image until it most closely resembles the STEM image. For example, the difference between the STEM image and the binarized image can be corrected by selecting "Fill" or "Delete" from the binarization menu. If the coloring of the binarized conductive fiber is insufficient compared to the conductive fiber, fill the hole; conversely, delete the excess colored area. Filling and deletion can be performed by setting an area threshold to fill or delete the extracted area. Clicking on the area to be deleted will display the threshold for that area.Additionally, if necessary, use the items in the Binarization Processing menu to correct and match the STEM image and the binarized image as closely as possible. You can also manually select and delete unnecessary portions of the binarized image using the eraser tool button. You can also manually paint on the window using the pen tool button to correct coloring. Once this is complete, select Shape Features from the Measurement menu and select the area of ​​the item you want to measure. The area of ​​each conductive fiber is measured, and you can also calculate the total value. This process measures the total area below and above half the thickness of the bridge wiring section. Furthermore, manually measure the areas of the ROI below and above half the thickness and calculate the ratios. Manual measurement is possible by selecting Line Length Measurement under Manual Measurement from the Measurement menu and selecting all line length measurement items. Using the appropriate tools in the Line Length Tool Palette, you can measure the line by dragging the start and end points with the mouse, and then calculate the ROI area. Note that the above process follows the WinROOF Version 7.4 User's Manual.

[0147] The absolute value of the difference in refractive index between the bridge wiring portion 13B and the electrical insulating layer 14 (|refractive index of the bridge wiring portion 13B−refractive index of the electrical insulating layer 14|) is preferably 0.08 or less. That is, the refractive index of the bridge wiring portion 13B is almost the same as the refractive index of the electrical insulating layer 14. This is because, although the bridge wiring portion 13B contains the conductive fibers 18B, the influence of the conductive fibers 18B is not taken into account when determining the refractive index of the bridge wiring portion 13B, and the refractive index of the bridge wiring portion 13B is the refractive index of the resin portion 17B. This suppresses interfacial reflection between the bridge wiring portion 13B and the electrical insulating layer 14, thereby preventing the bridge wiring portion 13B from being visible. Note that if the conductive fibers 18B are visible, this is not due to interfacial reflection but rather to the haze caused by scattering by the conductive fibers. This can be resolved by reducing the fiber diameter of the conductive fibers 18B, for example, to 30 nm or less. The difference in refractive index between the bridge wiring portion 13B and the electrical insulating layer 14 is more preferably 0.07 or less, 0.06 or less, or 0.05 or less.

[0148] The method for measuring the refractive index of the bridge wiring portion 13B is not particularly limited, and measurement can be performed using the Becke method. The Becke method uses a refractive index standard solution with a known refractive index. A fragment taken from the bridge wiring portion is placed on a slide glass or the like, the refractive index standard solution is dropped onto the fragment, and the fragment is immersed in the refractive index standard solution. The state of the fragment is observed under a microscope. The refractive index of the refractive index standard solution is determined as the refractive index of the bridge wiring portion. When measuring the refractive index of the bridge wiring portion 13B using the Becke method, fragments of the bridge wiring portion 13B are first extracted one by one from any five locations on the bridge wiring portion 13B by cutting or other methods. Here, the refractive index of the surface side of the bridge wiring portion 13B, which affects the visibility of the bridge wiring portion 13B, is the refractive index on the surface side of the bridge wiring portion 13B. The fragments do not necessarily have to be made of conductive fibers alone. That is, the fragments may include the resin portion 17B and the conductive fibers 18B, or may include only the resin portion 17B without the conductive fibers 18B. Note that observation using the Becke method is performed visually using a microscope, so observation is performed at low magnification. At such low magnification, the conductive fibers 18B are not visible. Therefore, the fragments may include only the resin portion 17B without the conductive fibers 18B. The refractive index of the bridge wiring portion 13B is then measured for each of the five fragments using the Becke method, and the arithmetic mean value of the refractive indexes of the three fragments excluding the maximum and minimum values ​​is defined as the refractive index of the bridge wiring portion 13B. The refractive indexes of the substrate 11, wiring portion 12B, and electrical insulation layer 14 can also be measured using the same method as for the bridge wiring portion 13B. The refractive index of the bridge wiring portion 13B is not particularly limited, but may be, for example, 1.45 to 1.60.

[0149] The conductive fibers 18B in the bridge wiring portion 13B may be arranged randomly, or may be aligned along the second direction DR2 as shown in Fig. 4. Whether the conductive fibers 18B are aligned along the second direction DR2 can be confirmed using, for example, a surface fiber orientation analysis program (V.8.03) (http: / / www.enomae.com / FiberOri / index.htm). This program is based on Enomae, T., Han, Y.-H. and Isogai, A., "Nondestructive determination of fiber orientation distribution of fiber surface by image analysis," Nordic Pulp and Paper Research Journal 21(2): 253-259(2006) and Enomae, T., Han, Y.-H. and Isogai, A., "Fiber orientation distribution of paper surface calculated by image analysis," Proceedings of International Papermaking and Environment Conference, Tianjin, PR China (May 12-14), Book2, 355-368 (2004)(http: / / www.enomae.com / publish.htm). In this program, a planar photograph of conductive fibers taken with a scanning electron microscope (SEM) is binarized, then Fourier transformed. The Fourier transformed image is then transformed into polar coordinates to calculate the average amplitude versus angle, thereby creating a fiber orientation distribution. Then, this fiber orientation distribution is approximated to an ellipse, the angle between the major axis of the approximated ellipse and the second direction is defined as the orientation angle, and the ratio of the major axis length to the minor axis length of the approximated ellipse (major axis length / minor axis length) is calculated as the orientation intensity. Specifically, 10 planar photographs of the conductive fibers in the conductive part are taken with an SEM at magnifications of 1000x to 6000x, the fiber orientation distribution is calculated for each of the 10 photographs, and the average fiber orientation distribution is calculated by averaging these fiber orientation distributions.The orientation angle and orientation strength are calculated from the average fiber orientation distribution according to the above method. For the conductive fibers 18B in the bridge wiring portion 13B, if the orientation angle is within 0°±10° (however, the calculated orientation angle is a value between 0° and 180°, but 180° and 90° should be interpreted as -0° to -90°) and the orientation strength is 1.2 or greater, it can be determined that the conductive fibers 18B are aligned in the second direction. It is more preferable that the orientation angle is within 0°±5°, and the orientation strength is more preferably 1.3 or greater, 1.5 or greater, or 1.7 or greater. In the above example, the conductive fibers 18B in the bridge wiring portion 13B are aligned along the second direction DR2. However, the conductive fibers 18A in the first electrode portion 12A and the wiring portion 12B may be aligned along the first direction DR1, and the conductive fibers 18A in the second electrode portion 13A may be aligned along the second direction DR2. Furthermore, when the conductive fibers 18B in the bridge wiring portion 13B are arranged randomly, even when the resistance value is measured in various directions, approximately the same resistance value can be obtained.

[0150] <<Electrical insulation layer>> Electrical insulating layer 14 is provided between wiring portion 12B and bridge wiring portion 13B. By providing such electrical insulating layer 14, contact between wiring portion 12B and bridge wiring portion 13B can be suppressed, and therefore electrical short-circuiting between first conductive portion 12 and second conductive portion 13 can be suppressed.

[0151] The size of the electrical insulating layer 14 is preferably larger than the sizes of the wiring portion 12B and the bridge wiring portion 13B, which can reliably prevent contact between the wiring portion 12B and the bridge wiring portion 13B.

[0152] The thickness of the electrical insulating layer 14 is preferably 160 nm or more and 2000 nm or less. If the thickness of the electrical insulating layer 14 is 160 nm or more, contact between the wiring portion 12B and the bridge wiring portion 13B can be reliably prevented, and if the thickness of the electrical insulating layer 14 is 2000 nm or less, cracks can be prevented when the layer is bent. From the viewpoint of more reliably preventing contact between the wiring portion 12B and the bridge wiring portion 13B and preventing cracks when the layer is bent, the thickness of the electrical insulating layer 14 is preferably 160 nm or more and 2000 nm or less, 160 nm or more and 1500 nm or less, 160 nm or more and 1300 nm or less, 160 nm or more and 1100 nm or less, 160 nm or more and 1000 nm or less, 180 nm or more and 2000 nm or less, 180 nm or more and 1500 nm or less, 180 nm or more and 1300 nm or less, 180 nm or more and ... More preferably, the thickness is 1100 nm or more, 180 nm or more, 1000 nm or less, 200 nm or more, 200 nm or more, 1500 nm or less, 200 nm or more, 1300 nm or more, 200 nm or more, 1100 nm or less, 200 nm or more, 1000 nm or less, or 250 nm or more, 2000 nm or less, 250 nm or more, 1500 nm or less, 250 nm or more, 1300 nm or more, 250 nm or more, 1100 nm or less, or 250 nm or more, 1000 nm or less.

[0153] The thickness of the electrical insulating layer 14 is determined by measuring the thickness at 10 random locations on a cross-sectional photograph of the electrical insulating layer taken using a transmission electron microscope (TEM), scanning transmission electron microscope (STEM), or scanning electron microscope (SEM), and averaging the thicknesses at 8 locations, excluding the maximum and minimum values, of the 10 measured thicknesses. Electrical insulating layers generally have thickness variations. In this embodiment, since the electrical insulating layer is used for optical purposes, the thickness variation is preferably within ±10% of the average thickness, and more preferably within ±5% of the average thickness.

[0154] When measuring the thickness of the electrical insulating layer 14 using a transmission electron microscope (TEM) or a scanning transmission electron microscope (STEM), the measurement can be performed using a method similar to that used to measure the thickness of the first conductive portion 12. However, the magnification when taking a cross-sectional photograph of the electrical insulating layer 14 is 100 to 20,000 times. When measuring the thickness of the substrate using a scanning electron microscope (SEM), the cross-section of the electrical insulating layer 14 can be obtained using an ultramicrotome (product name "Ultramicrotome EM UC7", manufactured by Leica Microsystems) or the like. Note that samples for TEM and STEM are prepared by using the above-mentioned ultramicrotome to prepare ultrathin sections with a feed thickness of 100 nm. The prepared ultrathin sections are collected using a collodion-coated mesh (150) to serve as samples for TEM and STEM. When cutting with the ultramicrotome, the sample may be pre-treated to make it easier to cut, such as by embedding it in resin.

[0155] The constituent material of the electrical insulating layer 14 is not particularly limited as long as it is an electrically insulating material, but if the sensor is for optical use, a material having optical transparency is preferable. When the constituent material of the electrical insulating layer 14 is a resin, examples of the resin include the same resins as those described in the section on the first electrode portion 12A, and therefore a description thereof will be omitted here.

[0156] <<Output wiring section>> The extracting wiring portion 15 is electrically connected to the first electrode portion 12A. Specifically, the extracting wiring portion 15 is electrically connected to the first electrode portion 12A at the end of the plurality of first electrode portions 12A arranged along the first direction DR1. The extracting wiring portion 15 shown in FIG. 1 is formed on the first electrode portion 12A and the substrate 11.

[0157] The extracting wiring portion 15 is not particularly limited as long as it is made of a conductive material. For example, the extracting wiring portion may be made of a hardened conductive paste. The conductive paste is not particularly limited, and examples thereof include silver paste.

[0158] <<Other sensors>> In sensor 10, conductive fibers 18A of first electrode portion 12A and second electrode portion 13A are covered with resin portion 17A. However, as in sensor 30 shown in FIG. 10, conductive fibers 18A of first electrode portion 12A and second electrode portion 13A may be covered with resin portions 17A and 17C (see FIGS. 11 and 12). The thickness of resin portion 17C is preferably 40 nm or more and 100 nm or less. When forming first conductive portion 12 using a roll-to-roll process, if substrate 11 on which conductive fibers 18A are arranged is wound up without the conductive fibers 18A being covered with a resin portion, there is a risk of conductive fibers 18A peeling off. In contrast, if the thickness of resin portion 17C is 40 nm or more, peeling of conductive fibers 18A can be prevented by winding a laminate in which resin portion 17C is formed on conductive fibers 18A. Furthermore, the thinner the resin portion 17C, the more the conductive fibers 18A are exposed from the resin portion 17C. Therefore, if the thickness of the resin portion 17C is 100 nm or less, the thickness of the resin portion 17C is small, and therefore the portion of the conductive fibers 18A that is exposed from the resin portion 17C increases, thereby making it possible to reduce the contact resistance value between the first conductive portion 12 and the extracting wiring portion 15.

[0159] The sensor 10 does not have an electrically insulating wall between the first conductive portion 12 and the second electrode portion 13A, but may have an electrically insulating wall 41 between the first conductive portion 12 and the second electrode portion 13A, as in the sensor 40 shown in Figure 13.

[0160] <<Wall section>> The wall portion 41 has a function of guiding the filling of the first conductive portion 12 and the second electrode portion 13A, and also has a function of suppressing an electrical short circuit between the first conductive portion 12 and the second electrode portion 13A. The wall portion 41 is made of an electrically insulating material. An example of the electrically insulating material is a resin. The resin is not particularly limited, but examples thereof include the resins described in the section on the electrical insulating layer.

[0161] The width W5 of the wall portion 41 (see FIG. 13) is preferably 5 μm or more and 500 μm or less. If the width W5 of the wall portion 41 is 5 μm or more, the wall portion 41 is less likely to collapse when filled with a conductive fiber dispersion liquid described below, and electrical short circuits can be further suppressed. If the width W of the wall portion 41 is 500 μm or less, a fine pattern can be arranged. The width W of the wall portion 41 is preferably 5 μm or more and 300 μm or less, 5 μm or more and 200 μm or less, 5 μm or more and 100 μm or less, 10 μm or more and 500 μm or less, 10 μm or more and 300 μm or less, 10 μm or more and 200 μm or less, 10 μm or more and 100 μm or less, 20 μm or more and 500 μm or less, 20 μm or more and 300 μm or less, 20 μm or more and 200 μm or less, 20 μm or more and 100 μm or less, 30 μm or more and 500 μm or less, 30 μm or more and 300 μm or less, 30 μm or more and 200 μm or less, or 30 μm or more and 100 μm or less.

[0162] The width W5 of the wall portion 41 is determined by measuring the width at 10 random locations on a cross-sectional photograph of the wall portion 41 taken using a scanning transmission electron microscope (STEM) or a transmission electron microscope (TEM), and calculating the arithmetic mean value of 8 widths excluding the maximum and minimum values ​​among the 10 measured widths. The cross-sectional photograph of the wall portion 41 is taken in the same manner as the cross-sectional photograph of the first conductive part 12.

[0163] The thickness of the wall portion 41 is preferably greater than the thicknesses of the first conductive portion 12 and the second electrode portion 13A. In FIG. 14, the thickness T of the wall portion 41 is greater than the thickness of the first electrode portion 12A. By making the thickness of the wall portion 41 greater than the thicknesses of the first conductive portion 12 and the second electrode portion 13A, electrical short-circuiting between the first conductive portion 12 and the second electrode portion 13A can be further suppressed. Specifically, the thickness of the wall portion 41 is more preferably greater than the thicknesses of the first conductive portion 12 and the second electrode portion 13A by 0.02 μm or more. The thickness of the wall portion 41 is the length of the wall portion 41 in the normal direction of the substrate 11, and the thickness of the first conductive portion 12 and the second electrode portion 13A is the length of the first conductive portion 12 and the second electrode portion 13A in the normal direction of the substrate 11.

[0164] The thickness of the wall portion 41 is preferably 0.1 μm or more and 100 μm or less. If the thickness of the wall portion 41 is 0.1 μm or more, it is possible to prevent the conductive fiber dispersion liquid from overflowing when filling the conductive fiber dispersion liquid described below. If the thickness of the wall portion 41 is 50 μm or less, it is possible to ensure foldability and followability during lamination. The thickness of the wall portion 41 is preferably 0.1 μm or more and 40 μm or less, 0.1 μm or more and 30 μm or less, 0.1 μm or more and 25 μm or less, 0.2 μm or more and 100 μm or less, 0.2 μm or more and 40 μm or less, 0.2 μm or more and 30 μm or less, 0.2 μm or more and 25 μm or less, 0.5 μm or more and 100 μm or less, 0.5 μm or more and 40 μm or less, 0.5 μm or more and 30 μm or less, 0.5 μm or more and 25 μm or less, 1 μm or more and 100 μm or less, 1 μm or more and 40 μm or less, 1 μm or more and 30 μm or less, or 1 μm or more and 25 μm or less.

[0165] The thickness of the wall portion 41 is determined by measuring the thickness at 10 random locations on a cross-sectional photograph of the wall portion 41 taken using a scanning transmission electron microscope (STEM) or a transmission electron microscope (TEM), and calculating the arithmetic mean value of the thicknesses at 8 locations among the 10 measured locations, excluding the maximum and minimum values. The method for taking the cross-sectional photograph of the wall portion 41 is the same as the method for taking the cross-sectional photograph of the first conductive part 12.

[0166] The absolute value of the refractive index difference between the wall portion 41 and the substrate 11 (refractive index of the wall portion 41 - refractive index of the substrate 11) is preferably 0.2 or less. If the absolute value of this refractive index difference is 0.2 or less, an increase in the haze value can be suppressed, and the shape of the wall portion 41 can be suppressed from being visible (bone visibility phenomenon). The refractive index of the wall portion 41 can be measured by the same method as the refractive index of the first conductive portion 12, etc.

[0167] The wall 41 can be formed by applying and curing a wall composition containing a polymerizable compound such as an ionizing radiation-polymerizable compound to the first surface 11A of the substrate 11. The wall composition can be applied by, for example, flexographic printing, offset printing, gravure printing, screen printing, an inkjet method, or a dispenser.

[0168] <<Sensor manufacturing method>> The sensor 10 can be fabricated, for example, as follows: First, as shown in Fig. 15(A), a conductive fiber dispersion containing conductive fibers 18B and a dispersion medium is applied using a dispenser or inkjet method to an area on the first surface 11A of the substrate 11 where the first conductive portion 12 and the second electrode portion 13A are to be formed, and then dried to arrange the conductive fibers 18A in the area where the first conductive portion 12 and the second electrode portion 13A are to be formed.

[0169] The conductive fiber dispersion may contain, in addition to the conductive fibers 18A and the dispersion medium, a resin component made of a thermoplastic resin or a polymerizable compound. In this specification, the term "resin component" refers to a resin (however, this does not include a resin (e.g., polyvinylpyrrolidone) that constitutes an organic protective layer formed around the conductive fibers during the synthesis of the conductive fibers to prevent the conductive fibers from self-welding or reacting with substances in the atmosphere), as well as a component that can be polymerized to form a resin, such as a polymerizable compound.

[0170] The dispersion medium may be either an aqueous dispersion medium or an organic dispersion medium. However, if the resin content in the conductive fiber dispersion is too high, the resin may penetrate between the conductive fibers, potentially impairing the conductivity of the conductive portion. This is particularly likely to occur when the conductive portion is thin. On the other hand, the use of an organic dispersion medium results in a lower resin content in the conductive fiber dispersion than when an aqueous dispersion medium is used. Therefore, when forming the first conductive portion 12 and the second electrode portion 13A with a thin film thickness, for example, 300 nm, it is preferable to use an organic dispersion medium. The organic dispersion medium may contain less water by mass.

[0171] The organic dispersion medium is not particularly limited, but is preferably a hydrophilic organic dispersion medium. Examples of organic dispersion media include saturated hydrocarbons such as hexane; aromatic hydrocarbons such as toluene and xylene; alcohols such as methanol, ethanol, propanol, and butanol; ketones such as acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone, and diisobutyl ketone; esters such as ethyl acetate and butyl acetate; ethers such as tetrahydrofuran, dioxane, and diethyl ether; amides such as N,N-dimethylformamide, N-methylpyrrolidone (NMP), and N,N-dimethylacetamide; and halogenated hydrocarbons such as ethylene chloride and chlorobenzene. Among these, alcohols are preferred from the viewpoint of the stability of the conductive fiber dispersion liquid.

[0172] Examples of thermoplastic resins that may be contained in the conductive fiber dispersion include acrylic resins; polyester resins such as polyethylene terephthalate; aromatic resins such as polystyrene, polyvinyl toluene, polyvinyl xylene, polyimide, polyamide, and polyamideimide; polyurethane resins; epoxy resins; polyolefin resins; acrylonitrile-butadiene-styrene copolymers (ABS); cellulose resins; polyvinyl chloride resins; polyacetate resins; polynorbornene resins; synthetic rubber; and fluorine-based resins.

[0173] Examples of polymerizable compounds that may be contained in the conductive fiber dispersion include the same polymerizable compounds as those described in the section on the electrical insulating layer 14, and therefore further description thereof will be omitted here.

[0174] After arranging the conductive fibers 18A, a conductive paste is applied to a portion of the surface of the conductive fibers 18A that will become the first electrode portion 12A located at the end of the multiple first electrode portions 12A arranged along the first direction DR1 using a dispenser or inkjet method to form a coating film. Next, the conductive paste is hardened by heating at a temperature of 80°C to 150°C for a predetermined time, forming the extracting wiring portion 15 shown in Figure 15(B).

[0175] After forming the output wiring portion 15, an electrical insulation layer composition is applied using a dispenser or inkjet printing to the conductive fibers 18A arranged in the area where the wiring portion 12B is to be formed, and then dried to form a coating film. The electrical insulation layer composition contains a polymerizable compound and a solvent, and may also contain a polymerization initiator or reaction inhibitor as needed. Next, the coating film is irradiated with ionizing radiation such as ultraviolet light to polymerize (crosslink) the polymerizable compound, thereby curing the coating film and forming the electrical insulation layer 14 shown in FIG. 16(A).

[0176] After forming the electrical insulating layer 14, a conductive fiber dispersion liquid containing conductive fibers 18B and a dispersion medium is applied to the surface of the electrical insulating layer 14 and the surface of the conductive fiber pattern 13A1 using a dispenser or an inkjet method in the area where the bridge wiring portion 13B is to be formed, and then dried to arrange the conductive fibers 18B shown in Figure 16(B).

[0177] The viscosity of the conductive fiber dispersion is preferably 0.01 Pa·s or more and 20 Pa·s or less. If the viscosity of the conductive fiber dispersion is 0.01 Pa·s or more, for example, when the conductive fiber dispersion is applied to a three-dimensional surface described below, the conductive fiber dispersion is less likely to run off, and the conductive fiber dispersion can be kept in the desired location. Furthermore, if the viscosity of the conductive fiber dispersion is 20 Pa·s or less, clogging of the conductive fiber dispersion can be suppressed when the conductive fiber dispersion is applied using a dispenser or inkjet method, and the conductive fiber dispersion can be easily discharged. The viscosity of the conductive fiber dispersion is 0.01 Pa·s or more and 10 Pa·s or less, 0.01 Pa·s or more and 8 Pa·s or less, 0.01 Pa·s or more and 5 Pa·s or less, 0.01 Pa·s or more and 1 Pa·s or less, 0.02 Pa·s or more and 20 Pa·s or less, 0.02 Pa·s or more and 10 Pa·s or less, 0.02 Pa·s or more and 8 Pa·s or less, 0.02 Pa·s or more and 5 Pa·s or less, 0.02 Pa·s or more and 1 Pa·s or less, 0.03 Pa·s or more It is more preferable that the viscosity is 20 Pa·s or less, 0.03 Pa·s or more and 10 Pa·s or less, 0.03 Pa·s or more and 8 Pa·s or less, 0.03 Pa·s or more and 5 Pa·s or less, 0.03 Pa·s or more and 1 Pa·s or less, 0.05 Pa·s or more and 20 Pa·s or less, 0.05 Pa·s or more and 10 Pa·s or less, 0.05 Pa·s or more and 8 Pa·s or less, 0.05 Pa·s or more and 5 Pa·s or less, or 0.05 Pa·s or more and 1 Pa·s or less.

[0178] The viscosity of the conductive fiber dispersion can be measured using a vibration viscometer (for example, product name "VM-10A-M" manufactured by Sekonic Corporation). Specifically, the viscosity of the conductive fiber dispersion is measured 10 times in an environment of a temperature of 25°C and a relative humidity of 30% to 70%, and the viscosity is calculated by calculating the arithmetic mean value of 8 viscosities excluding the maximum and minimum values ​​among the 10 measured viscosities.

[0179] The conductive fiber dispersion is preferably applied using a contact-type dispenser. By applying the conductive fiber dispersion using a contact-type dispenser, the conductive fibers 18B of the bridge wiring portion 13B can be aligned in the second direction DR2. Specifically, the discharge part of the contact-type dispenser is moved in the second direction DR2 relative to the substrate 11, and the conductive fiber dispersion is discharged from the discharge part along the second direction DR2 to apply the conductive fiber dispersion in a line. This results in the arrangement of the conductive fibers. In this specification, the term "contact-type dispenser" refers to a dispenser whose discharge part directly contacts a pool of conductive fiber dispersion formed on the surface to be coated. Furthermore, "moving the discharge part of the dispenser relative to the substrate" may refer to either moving the discharge part of the dispenser relative to the substrate or moving the substrate relative to the discharge part of the dispenser. The discharge part is configured to discharge the conductive fiber dispersion by, for example, pushing a plunger with air pressure. Examples of the discharge part include a syringe and a nozzle.

[0180] When the conductive fiber dispersion is discharged, the relative movement speed of the discharge part with respect to the substrate 11 is preferably 5 mm / sec or more and 500 mm / sec or less. If the relative movement speed is 5 mm / sec or more, the wet spreading of the conductive fibers 18B can be suppressed, and if it is 500 mm / sec or less, the conductive fiber dispersion can be discharged in a linear form without running out of liquid. The relative movement speed is more preferably 5 mm / sec to 450 mm / sec, 5 mm / sec to 420 mm / sec, 5 mm / sec to 400 mm / sec, 10 mm / sec to 500 mm / sec, 10 mm / sec to 450 mm / sec, 10 mm / sec to 420 mm / sec, 10 mm / sec to 400 mm / sec, 15 mm / sec to 500 mm / sec, 15 mm / sec to 450 mm / sec, 15 mm / sec to 420 mm / sec, 15 mm / sec to 400 mm / sec, 20 mm / sec to 500 mm / sec, 20 mm / sec to 450 mm / sec, 20 mm / sec to 420 mm / sec, or 20 mm / sec to 400 mm / sec. In this specification, the "relative movement speed of the discharge portion relative to the substrate" refers to the relative movement speed in the direction in which the linear coating portion is formed.

[0181] The distance (coating gap) between the discharge part and the electrical insulating layer when discharging the conductive fiber dispersion is preferably 5 μm or more and 80 μm or less. If the coating gap is 5 μm or more, contact between the discharge part and the electrical insulating layer can be suppressed, and if it is 80 μm or less, the conductive fiber dispersion can be discharged in a linear fashion without running out of liquid. More preferably, the coating gap is 5 μm to 70 μm, 5 μm to 60 μm, 5 μm to 50 μm, 10 μm to 80 μm, 10 μm to 70 μm, 10 μm to 60 μm, 10 μm to 50 μm, 15 μm to 80 μm, 15 μm to 70 μm, 15 μm to 60 μm, 15 μm to 50 μm, 20 μm to 80 μm, 15 μm to 70 μm, 15 μm to 60 μm, or 15 μm to 50 μm.

[0182] The diameter of the discharge port of the discharge part is preferably 20 μm or more and 200 μm or less. If the diameter of the discharge port is 20 μm or more, clogging of the discharge port with the conductive fiber dispersion can be suppressed, and if the diameter is 200 μm or less, outflow of the conductive fiber dispersion can be suppressed. The diameter of the discharge port is more preferably 20 μm or more and 160 μm or less, 20 μm or more and 120 μm or less, 20 μm or more and 100 μm or less, 22 μm or more and 200 μm or less, 22 μm or more and 160 μm or less, 22 μm or more and 120 μm or less, 22 μm or more and 100 μm or less, 24 μm or more and 200 μm or less, 24 μm or more and 160 μm or less, 24 μm or more and 120 μm or less, 24 μm or more and 100 μm or less, 25 μm or more and 200 μm or less, 25 μm or more and 160 μm or less, 25 μm or more and 120 μm or less, or 25 μm or more and 100 μm or less.

[0183] The discharge pressure of the conductive fiber dispersion when it is discharged is preferably 1 kPa or more and 50 kPa or less. If the discharge pressure is 1 kPa or more, the conductive fiber dispersion can be discharged without clogging, and if it is 50 kPa or less, excessive pressure can be prevented from being applied to the conductive fiber dispersion. The discharge pressure is more preferably 1 kPa or more and 40 kPa or less, 1 kPa or more and 30 kPa or less, 1 kPa or more and 20 kPa or less, 2 kPa or more and 50 kPa or less, 2 kPa or more and 40 kPa or less, 2 kPa or more and 30 kPa or less, 2 kPa or more and 20 kPa or less, 4 kPa or more and 50 kPa or less, 4 kPa or more and 40 kPa or less, 4 kPa or more and 30 kPa or less, 4 kPa or more and 20 kPa or less, 5 kPa or more and 50 kPa or less, 5 kPa or more and 40 kPa or less, 5 kPa or more and 30 kPa or less, or 5 kPa or more and 20 kPa or less.

[0184] The drying temperature of the conductive fiber dispersion is preferably 60°C or higher and 200°C or lower. If the drying temperature of the conductive fiber dispersion is 60°C or higher, a wider variety of substrates can be used when the conductive fiber dispersion is applied to, for example, a three-dimensional surface (described later). Furthermore, if the drying temperature of the conductive fiber dispersion is 200°C or lower, dimensional changes in the substrate can be suppressed. The drying temperature of the conductive fiber dispersion is more preferably 60°C or higher and 180°C or lower, 60°C or higher and 160°C or lower, 60°C or higher and 150°C or lower, 80°C or higher and 200°C or lower, 80°C or higher and 180°C or lower, 80°C or higher and 160°C or lower, 80°C or higher and 150°C or lower, 90°C or higher and 200°C or lower, 90°C or higher and 180°C or lower, 90°C or higher and 160°C or lower, 90°C or higher and 150°C or lower, 100°C or higher and 200°C or lower, 100°C or higher and 180°C or lower, 100°C or higher and 160°C or lower, or 100°C or higher and 150°C or lower.

[0185] After the conductive fiber 18B is positioned, a resin composition is applied using a die coater, dispenser, or inkjet method to cover the conductive fibers 18A, 18B, and then dried to form a coating. The resin composition contains a polymerizable compound and a solvent, and may also contain a polymerization initiator or reaction inhibitor, if necessary. The coating is then irradiated with ionizing radiation such as ultraviolet light to polymerize (crosslink) the polymerizable compound, thereby curing the coating and forming a resin layer 17 including resin portions 17A, 17B as shown in FIG. 17. This results in the sensor 10 shown in FIG. 1.

[0186] In the above, the conductive fiber dispersion containing the conductive fibers 18A and the conductive fiber dispersion containing the conductive fibers 18B are applied using a dispenser or an inkjet method, but these conductive fiber dispersions may also be applied by, for example, a spray coating method, a dip coating method, a drop casting method, etc. Among these, application using a dispenser or an inkjet method is particularly preferred because the dispenser or inkjet method can suppress aggregation of the conductive fibers, enable the formation of a fine pattern, and can provide a coating film with excellent uniformity.

[0187] <<Other manufacturing methods for sensors>> The sensor 30 can also be produced by, for example, the following method: First, as shown in Fig. 18(A), a conductive fiber dispersion liquid containing conductive fibers 18A and a dispersion medium is applied to the entire first surface 11A of the substrate 11 using a coating device such as a die coater, and then dried to arrange the conductive fibers 18A.

[0188] Thereafter, a resin composition containing a polymerizable compound and a solvent is applied to the entire surface of the conductive fibers 18A using a coating device such as a die coater, and the coating is dried to form a coating film of the resin composition. Next, the coating film is irradiated with ionizing radiation such as ultraviolet light to polymerize (crosslink) the polymerizable compound and harden the coating film, forming the resin shown in Figure 18(B), which forms a conductive layer 51 having resin portion 17C and conductive fibers 18A arranged in resin portion 17C.

[0189] After forming the conductive layer 51, a conductive paste is applied to the surface of the resin portion 17C in the region where the first electrode portion 12A is to be formed, using a screen printing method or the like, to form a coating film. Next, the conductive paste is cured by heating at a temperature of 80°C or higher and 150°C or lower for a predetermined time, thereby obtaining the cured conductive paste 52 shown in Fig. 19(A).

[0190] After the conductive paste is hardened, the conductive layer 51 and the hardened conductive paste 52 are patterned to form conductive fibers 18A in the shapes of the first conductive portion 12 and the second electrode portion 13A, and to form the extraction wiring portion 15. Specifically, laser light (e.g., infrared laser) is irradiated onto the areas that will become the first conductive portion 12 and the second electrode portion 13A to etch the conductive layer 51 by dry etching, and laser light (e.g., infrared laser) is irradiated onto the hardened conductive paste 52 so that the hardened conductive paste 52 is positioned on a portion of the surface of the first electrode portion 12A located at the end of the multiple first electrode portions 12A arranged along the first direction DR1, to etch the hardened conductive paste 52. When the laser light is irradiated onto the conductive layer 51, the heat of the laser light sublimates the conductive fibers 18A contained in this area. The sublimated conductive fibers 18A break through the resin portion 17C and are released outside the resin portion 17C. In the above, the conductive layer 51 and the hardened conductive paste 52 are patterned by dry etching, but the conductive layer 51 and the hardened conductive paste 52 may also be patterned by photolithography.

[0191] The subsequent steps of forming the electrical insulating layer 14 and the bridge wiring portion 13B are the same as those when fabricating the sensor 10, and therefore a description thereof will be omitted here. In this way, the sensor 30 can be obtained.

[0192] If the bridge wiring portion is made of an oxide material such as ITO, there is a risk of breakage or cracks occurring when the sensor is folded, making it difficult to obtain good flexibility. In contrast, according to this embodiment, the bridge wiring portion 13B contains conductive fiber 18B, so good flexibility can be obtained.

[0193] According to this embodiment, the bridge wiring portion 13B includes the conductive fibers 18B, but since the conductive fibers 18B are disposed in the resin portion 17B, most of the bridge wiring portion 13B is the resin portion 17B. Therefore, the refractive index of the bridge wiring portion 13B is almost the same as the refractive index of the resin portion 17B. This makes it possible to make the bridge wiring portion invisible.

[0194] According to this embodiment, the bridge wiring portion 13B includes conductive fibers 18B, which are the same type of conductive material as the conductive fibers 18A contained in the second electrode portion 13A. However, since the conductive fibers 18B are disposed within the resin portion 17B, most of the bridge wiring portion 13B is made up of the resin portion 17B. Therefore, the refractive index of the bridge wiring portion 13B is almost the same as that of the resin portion 17B. This reduces the refractive index difference between the second electrode portion 13A and the bridge wiring portion 13B, thereby making the bridge wiring portion 13B invisible. Conventionally, the second electrode portion and the bridge wiring portion are formed by etching. However, if the second electrode portion and the bridge wiring portion were to be made of the same conductive material, it would be difficult to make the second electrode portion and the bridge wiring portion out of the same conductive material because the second electrode portion would also be etched when the bridge wiring portion was etched.

[0195] According to this embodiment, the first electrode portion 12A, the wiring portion 12B, the second electrode portion 13A, and the bridge wiring portion 13B are formed by applying a conductive fiber dispersion liquid, eliminating the need for patterning by etching. This allows unnecessary conductive fibers 18A and 18B to be eliminated, thereby reducing costs. Furthermore, because etching is no longer necessary, the number of processes is reduced, thereby shortening the manufacturing time.

[0196] According to the sensor 40, a wall portion 41 is formed between the first conductive portion 12 and the second electrode portion 13A, so that the wall portion 41 can suppress migration of conductive fibers from the first conductive portion 12 and the second electrode portion 13A, thereby suppressing electrical short circuits between the first conductive portion 12 and the second electrode portion 13A.

[0197] Typically, a die coating method or a bar coating method is used to apply a conductive fiber dispersion. However, when a conductive layer is formed using the die coating method or the bar coating method, the conductive fibers are randomly arranged. Therefore, even if the conductive layer is etched to form a patterned linear conductive portion, the conductive fibers are randomly arranged. Furthermore, when a linear conductive portion is formed by applying a conductive fiber dispersion using a non-contact dispenser or an inkjet method, although there is a directionality of the conductive fibers in each droplet, there is no directionality in the applied conductive fibers as a whole, so the conductive fibers in the conductive portion are randomly arranged. Furthermore, when a linear conductive portion is formed by applying a conductive fiber dispersion using a screen printing method, the conductive fibers in the conductive portion are also randomly arranged. On the other hand, when the conductive fibers are aligned in a certain direction, the linear resistance value is lower than when the conductive fibers are randomly arranged. According to this embodiment, when the discharge part of a contact-type dispenser is moved relative to the substrate 11 and the conductive fiber dispersion liquid containing the conductive fibers 18B is applied from the discharge part to the first surface 11A of the substrate 11, the conductive fibers 18B can be aligned along the direction of movement of the discharge part or the substrate 11. This is thought to be because the narrow opening of the dispenser discharge part prevents the conductive fibers from lying flat when the conductive fiber dispersion liquid is applied, and the conductive fibers are applied with their longitudinal direction oriented normal to the substrate 11. This reduces the linear resistance of the bridge wiring portion 13B, thereby reducing the content of the conductive fibers 18B in the bridge wiring portion 13B. This allows for a desired linear resistance value and reduces costs.

[0198] As described above, when the conductive fiber dispersion is applied by the die coating method or bar coating method, the conductive portion is formed in a layer, and therefore, patterning by etching is required to form a linear conductive portion. Patterning by etching removes unnecessary conductive portions, and the conductive fibers contained in the portions removed by etching are wasted. In contrast, according to this embodiment, when the conductive fiber dispersion is directly applied in a linear shape, patterning by etching is not necessary. This reduces the waste of conductive fibers 18A and 18B, thereby reducing costs. Furthermore, because etching is not required, the number of processes is reduced, and the manufacturing time can also be shortened.

[0199] According to this embodiment, when the conductive fibers 18B in the bridge wiring portion 13B are aligned along the second direction DR2, the linear resistance value of the bridge wiring portion 13B can be reduced, and as a result, the content of the conductive fibers 18B in the bridge wiring portion 13B can be reduced, thereby achieving a desired linear resistance value and reducing costs.

[0200] According to this embodiment, the first conductive portion 12 and the second electrode portion 13A are formed by filling the space between the wall portions 41 with a conductive fiber dispersion liquid, eliminating the need for patterning by etching. This allows unnecessary conductive fibers 18A to be eliminated, thereby reducing costs. Furthermore, because etching is no longer necessary, the number of processes is reduced, and the manufacturing time can also be shortened.

[0201] According to this embodiment, the first conductive portion 12 and the second electrode portion 13A are formed between the wall portions 41, so that the wall portions 41 can suppress migration of conductive material from the first conductive portion 12 and / or the second electrode portion 13A, thereby suppressing electrical short circuits between the first conductive portion 12 and the second conductive portion 13.

[0202] The sensors 10 and 20 are incorporated into an article for use. The article is not particularly limited, but an example thereof is an image display device. Fig. 20 is a schematic diagram of an image display device according to this embodiment.

[0203] <<<Image display devices>>> An image display device 60 shown in Fig. 20 includes a display element 70, a circular polarizer 80, a sensor 10, and a cover member 90, in this order, facing the viewer. The sensor 10 functions as a touch panel, and is arranged so that the bridge wiring portion 13B is closer to the viewer than the first conductive portion 12. The display element 70 and the circular polarizer 80, the circular polarizer 80 and the sensor 10, and the sensor 10 and the cover member 90 are bonded together via adhesive layers 91 to 93. In this specification, the term "bonding" is a concept that includes adhesion.

[0204] <<Display element>> Examples of the display element 70 include a liquid crystal display element, an organic light-emitting diode element (hereinafter sometimes referred to as an "OLED element"), an inorganic light-emitting diode element, a micro LED, and a plasma element. Known organic light-emitting diode elements can be used as the organic light-emitting diode element. The liquid crystal display element may also be an in-cell touch panel liquid crystal display element that has a touch panel function built into the element.

[0205] <<Circular polarizer>> The circular polarizer 80 has a function of suppressing external light reflection, and is therefore particularly effective when an OLED element is used as the display element. The circular polarizer 80 includes, for example, a first retardation film, an adhesive layer, a second retardation film, an adhesive layer, and a polarizer, in this order, facing the viewer side.

[0206] From the viewpoint of achieving a thinner circular polarizer 80, the thickness is preferably 100 μm or less. From the viewpoint of processability due to a decrease in strength, the thickness of the circular polarizer 80 is preferably 20 μm to 100 μm, 20 μm to 95 μm, 20 μm to 90 μm, 20 μm to 80 μm, 30 μm to 100 μm, 30 μm to 95 μm, 30 μm to 90 μm, 30 μm to 80 μm, 50 μm to 100 μm, 50 μm to 95 μm, 50 μm to 90 μm, or 50 μm to 80 μm. The thickness of the circular polarizer 80 can be determined by photographing a cross section of the circular polarizer 80 using a scanning electron microscope (SEM), measuring the thickness of the circular polarizer 80 at 10 points on the image of the cross section, and calculating the arithmetic mean value of the thickness at 8 points, excluding the maximum and minimum values, among the 10 thickness points.

[0207] The circular polarizer 80 may be incorporated into an image display device by either a chip-cut method or a roll-to-panel method. The chip-cut method involves cutting a circular polarizer of a predetermined size from a roll of circular polarizer to match the size of the image display device, and then attaching it to a cover member such as glass via an adhesive layer. The roll-to-panel method involves cutting a roll of circular polarizer as it is fed out on the image display device manufacturing line, and then attaching it to a cover member such as glass via an adhesive layer.

[0208] <<Cover material>> A surface 90A of the cover member 90 serves as the surface 60A of the image display device 60. The cover member 90 may be a cover glass or a cover film made of a resin. When the image display device 60 is flexible, the cover member 90 is preferably made of flexible glass or flexible resin. Examples of flexible resins include polyimide resins, polyamideimide resins, polyamide resins, polyester resins (e.g., polyethylene terephthalate resins and polyethylene naphthalate resins), and mixtures of two or more of these resins.

[0209] <<adhesive layer>> The adhesive layers 91 to 93 can be made of a cured liquid ionizing radiation curable adhesive containing a polymerizable compound (for example, OCR: Optically Clear Resin) or a pressure sensitive adhesive (for example, OCA: Optical Clear Adhesive).

[0210] <<<Conductors>>> The conductor comprises a three-dimensional object having a three-dimensional surface, a resin portion provided on the three-dimensional surface, and a conductive portion including a conductive fiber pattern (first conductive fiber pattern) arranged in the resin portion, the conductive fiber pattern consisting of a plurality of conductive fibers, and conforming to the shape of the three-dimensional surface. Such a conductor is not particularly limited as long as it has a conductive fiber pattern conforming to the shape of the three-dimensional surface, but examples include the sensor 10 described above. In this case, "conforms" means that the conductive fiber pattern as a whole conforms to the three-dimensional surface and is electrically connected. Therefore, each conductive fiber does not have to conform to the three-dimensional surface. Furthermore, the conductive fiber pattern does not need to conform strictly to the shape of the three-dimensional surface; as long as it conforms roughly, it is considered to be conforming to the three-dimensional surface. Whether or not the conductive fiber pattern is electrically connected can be confirmed by measuring its linear resistance. For example, if the linear resistance of the conductive fiber pattern is 1,000,000 Ω or less, it can be determined that the conductive fiber pattern is electrically connected.

[0211] The use of the conductor is not particularly limited, but the conductor can be incorporated into a sensor and used in various products (e.g., image display devices and biosensors). The use of the sensor is the same as that of the sensor described above in the sensor section.

[0212] The following describes the case where the conductor 100 (see FIGS. 1 and 3) is a sensor 10. The conductor 100 includes a three-dimensional object 101 as shown in FIG. 3. In FIG. 3, the three-dimensional object 101 is composed of a substrate 11, a first conductive portion 12 provided on a first surface 11A of the substrate 11 and having a plurality of first electrode portions 12A arranged in a first direction DR1 and a wiring portion 12B that electrically connects adjacent first electrode portions 12A, a plurality of conductive fiber patterns 13A1 provided on the first surface 11A of the substrate 11, spaced apart from the first conductive portion 12 and arranged in a second direction DR2 that intersects with the first direction DR1, and an electrical insulating layer 14 disposed on the wiring portion 12B.

[0213] The three-dimensional object 101 has a three-dimensional surface 101A. The three-dimensional surface is not particularly limited, but examples include a three-dimensional surface formed by combining flat surfaces, a curved surface, a combination of flat and curved surfaces, and a surface with steps. While it is typically very difficult to apply conductive fibers to a shape with a step of 50 μm or more, application using a dispenser or inkjet method is possible. Therefore, the three-dimensional surface may have a step of 50 μm or more (e.g., a step of 1 mm or more or a step of 1 cm or more). In FIG. 3, the wiring portion 12B and the conductive fiber pattern 13A1 are both formed on the first surface 11A of the substrate 11, and the electrical insulating layer 14 is formed on the wiring portion 12B. Therefore, the surface 14A of the electrical insulating layer 14 is higher than the surface 13A11 of the conductive fiber pattern 13A1. Therefore, the surface formed by the surface 14A of the electrical insulating layer 14 and the surface 13A11 of the conductive fiber pattern 13A1 constitutes the three-dimensional surface 101A. 3, the upper surface 14A1 of the surface 14A of the electrical insulating layer 14 is flat and the side surface 14A2 is approximately parallel to the normal direction DR3 of the base material 11, but for example, as in the conductor 110 shown in Fig. 21, the upper surface 14A1 of the electrical insulating layer 14 may be curved and the side surface 14A2 may be inclined with respect to the normal direction DR3 of the base material 11. In Fig. 21, the members denoted with the same reference numerals as those in Fig. 3 are the same as the members shown in Fig. 3, and therefore description thereof will be omitted.

[0214] The conductive portion 102 includes a conductive fiber pattern 102A, which is formed on the surface 14A of the electrical insulating layer 14 between the surfaces 13A11 of adjacent conductive fiber patterns 13A1 and the conductive fiber pattern 13A1 so as to straddle the wiring portion 12B and electrically connect adjacent conductive fiber patterns 13A1. That is, the conductive portion 102 serves as a bridge wiring portion 13B. When the conductive portion 102 is a bridge wiring portion 13B, the conductive portion 102 includes a resin portion 17B in addition to the conductive fiber pattern 102A. However, the conductive portion does not need to include a resin portion as long as it includes a conductive fiber pattern.

[0215] In the above, the three-dimensional object 101 is composed of a substrate 11, etc., but the three-dimensional object 101 is not particularly limited as long as it has a shape with a three-dimensional surface. Furthermore, the three-dimensional surface 101A is composed of the surface 14A of the electrical insulating layer 14 and the surface 13A11 of the conductive fiber pattern 13A1, but the surface is not particularly limited to this configuration. For example, the three-dimensional object may be a plano-convex lens whose three-dimensional surface is a convex surface. In the above, the conductive portion 102 is the bridge wiring portion 13B, but it does not have to be the bridge wiring portion 13B.

[0216] When forming the conductive fiber pattern 102A on the three-dimensional surface 101A, the conductive fiber dispersion is applied while moving the discharge unit of a dispenser or inkjet device or the three-dimensional object 101. Preferably, the distance between the discharge unit and the surface 14A of the electrical insulating layer 14 and the surface 13A11 of the conductive fiber pattern 13A1 is controlled. For example, the distance between the discharge unit of the dispenser and the surface 14A of the electrical insulating layer 14 and the surface 13A11 of the conductive fiber pattern 13A1 may be controlled to be approximately constant. By controlling the distance between the discharge unit and the surface 14A of the electrical insulating layer 14 and the surface 13A11 of the conductive fiber pattern 13A1 during application of the conductive fiber dispersion, even when conductive fibers 18A with an aspect ratio of 5 or greater are arranged on the three-dimensional surface 101A, the conductive fibers 18A can be evenly distributed. This allows the conductive fiber pattern 13B1 to be uniformly formed on the three-dimensional surface 101A. This allows the conductive fiber pattern 13B1 to be formed conforming to the three-dimensional surface 101A.

[0217] The conductor 130 shown in FIG. 22 is incorporated into, for example, a cotton-swab-type biosensor 120. The biosensor 120 includes the conductor 130 and a covering portion 140 that covers a portion of the conductor 130. The conductor 130 includes a support (three-dimensional object) 131 having a three-dimensional surface 131A, and a conductive portion 132 that is provided on the three-dimensional surface 131A and includes a conductive fiber pattern 132A that is made of a plurality of conductive fibers and conforms to the shape of the three-dimensional surface 131A. The covering portion 140 covers the conductive portion 132. In the biosensor 120, for example, when the inside of the nasal cavity or oral cavity is swabbed with the biosensor 120 and a sample such as nasal mucus, mucus, or saliva adheres to the covering portion 140, the sample passes through the covering portion 140 and is introduced into the conductive portion 132, making it available for testing.

[0218] The conductive portion 132 includes a resin portion (not shown) in addition to the conductive fiber pattern 132A, but the conductive portion 132 does not need to include a resin portion as long as it includes the conductive fiber pattern 132A. The conductive fibers that make up the conductive fiber pattern 132A are the same as the conductive fibers 18A, so a description thereof will be omitted here.

[0219] According to this embodiment, the conductors 100, 110, 130 include conductive fiber patterns 102A, 132A that conform to the three-dimensional surfaces 101A, 131A, so it is possible to obtain conductors 100, 110, 130 having conductive fiber patterns 102A, 132A that can be adapted to various three-dimensional surfaces 101A, 131A. Furthermore, such conductors 100, 110, 130 can obtain performance according to the purpose. [Example]

[0220] In order to explain the present invention in detail, examples are given below, but the present invention is not limited to these descriptions.

[0221] <Preparation of silver nanowire dispersion> (Silver nanowire dispersion 1) Ethylene glycol was prepared as the alcohol solvent, silver nitrate as the silver compound, sodium chloride as the chloride, sodium bromide as the bromide, sodium hydroxide as the alkali metal hydroxide, aluminum nitrate nonahydrate as the aluminum salt, and a copolymer of vinylpyrrolidone and diallyldimethylammonium nitrate (copolymer prepared from 99% by mass of vinylpyrrolidone and 1% by mass of diallyldimethylammonium nitrate, weight average molecular weight 130,000) was prepared as the organic protective agent.

[0222] At room temperature, 0.041 g of sodium chloride, 0.0072 g of sodium bromide, 0.0506 g of sodium hydroxide, 0.0416 g of aluminum nitrate nonahydrate, and 5.24 g of vinylpyrrolidone and diallyldimethylammonium nitrate copolymer were dissolved in 540 g of ethylene glycol to form solution A. In a separate container, 4.25 g of silver nitrate was dissolved in 20 g of ethylene glycol to form solution B. In this example, the Al / OH molar ratio was 0.0876, and the OH / Ag molar ratio was 0.0506.

[0223] The entire amount of solution A was heated from room temperature to 115°C while stirring, and then the entire amount of solution B was added to solution A over 1 minute. After the addition of solution B was completed, the mixture was further stirred and held at 115°C for 24 hours. The reaction solution was then cooled to room temperature. After cooling, acetone in an amount 10 times the reaction solution was added to the reaction solution, and after stirring for 10 minutes, the mixture was allowed to stand for 24 hours. After standing, a concentrate and a supernatant were observed, so the supernatant was carefully removed with a pipette to obtain a concentrate.

[0224] 500g of pure water was added to the resulting concentrate and stirred for 10 minutes to disperse the concentrate. Then, 10 times the volume of acetone was added, and the mixture was stirred again and left to stand for 24 hours. After standing, new concentrate and supernatant were observed, and the supernatant was carefully removed with a pipette. Excess organic protective agent is unnecessary for achieving good conductivity, so this washing procedure was repeated 1 to 20 times as necessary to thoroughly wash the solids.

[0225] Pure water was added to the washed solids to obtain a dispersion of this solid. An aliquot of this dispersion was taken, and the pure water solvent was evaporated on an observation table. After that, the solids were observed with a high-resolution FE-SEM (high-resolution field emission scanning electron microscope), and it was confirmed that the solids were silver nanowires.

[0226] Isopropyl alcohol was added to the washed silver nanowires to obtain Silver Nanowire Dispersion 1. Measurement of the average fiber diameter and average fiber length of the silver nanowires in Silver Nanowire Dispersion 1 revealed that the average fiber diameter was 45 nm and the average fiber length was 15 μm. The concentration of silver nanowires in Silver Nanowire Dispersion 1 was 1.5 mg / ml. The viscosity of Silver Nanowire Dispersion 1 was 0.08 Pa s.

[0227] The average fiber diameter of the silver nanowires was determined using a transmission electron microscope (TEM) (product name "H-7650" manufactured by Hitachi High-Technologies Corporation) by taking 50 images at 100,000 to 200,000 magnifications. The fiber diameters of 100 conductive fibers were measured on the image screen using the software provided with the TEM, and the arithmetic mean value was calculated. The fiber diameters were measured under the following conditions: acceleration voltage: 100 kV, emission current: 10 μA, focusing lens aperture: 1, objective lens aperture: 0, observation mode: "HC," and Spot: 2. The average fiber length of the silver nanowires was determined using a scanning electron microscope (SEM) (product name "S-4800 (TYPE 2)" manufactured by Hitachi High-Technologies Corporation) by measuring the fiber lengths of 100 silver nanowires at 5,000,000 to 20,000,000 magnifications. The arithmetic mean value of the 98 fiber lengths, excluding the maximum and minimum values, was calculated. When measuring the fiber length, the signal selection was "SE," the acceleration voltage was "3 kV," the emission current was "10 μA," and the SE detector was "mixed." The fiber length of the silver nanowires was measured using the SEM function of a scanning electron microscope (SEM) (product name "S-4800 (TYPE 2), Hitachi High-Technologies Corporation) by taking 10 images at 5-20 million magnifications, and the fiber lengths of 100 silver nanowires were measured on the image screen using the accompanying software. Of the fiber lengths of the 100 silver nanowires, the arithmetic mean value of 98 fibers, excluding the maximum and minimum values, was calculated. The fiber length measurements were performed using a 45° tilted sample stage. The signal selection was set to "SE," the acceleration voltage to "3 kV," the emission current to "10 μA-20 μA," the SE detector to "Mixed," the probe current to "Norm," the focus mode to "UHR," the condenser lens 1 to "5.0," the working distance to "8 mm," and the tilt to "30°." The TE detector was removed in advance. The measurement sample prepared by the following method was used to measure the silver nanowire fiber diameter. First, silver nanowire dispersion 1 was diluted with ethanol to a silver nanowire concentration of 0.05% by mass or less, matching the dispersion medium.Furthermore, one drop of this diluted silver nanowire dispersion 1 was placed on a grid mesh with a carbon support film for TEM or STEM observation (Cu grid model number "#10-1012 Elastic Carbon ELS-C10 STEM Cu100P grid specification"), dried at room temperature, and observed under the above conditions to obtain observation image data. The arithmetic mean value was calculated based on this. When measuring the fiber length of the silver nanowires, a measurement sample prepared by the following method was used. First, silver nanowire dispersion 1 was applied to the untreated surface of a B5-sized polyethylene terephthalate (PET) film with a thickness of 50 μm, with a silver nanowire coating amount of 10 mg / m. 2 The dispersion medium was then dried, and conductive fibers were placed on the surface of the PET film to produce a sensor. A 10 mm x 10 mm piece was cut from the center of this sensor. This cut sensor was then attached flat to the surface of a 45° inclined SEM sample stage (model number "728-45," manufactured by Nissin EM Co., Ltd., inclined sample stage 45°, φ15 mm x 10 mm, M4 aluminum) using silver paste. Further, Pt-Pd was sputtered for 20 to 30 seconds to obtain electrical conductivity.

[0228] The viscosity of silver nanowire dispersion 1 was measured using a vibration viscometer (product name "VM-10A-M", manufactured by Sekonic Corporation). Specifically, the viscosity of silver nanowire dispersion 1 was measured 10 times in an environment of a temperature of 25°C and a relative humidity of 50%, and the viscosity was calculated by calculating the arithmetic mean value of 8 viscosities, excluding the maximum and minimum values, out of the 10 measured viscosities.

[0229] (Silver nanowire dispersion 2) Silver nanowire dispersion liquid 2 was obtained in the same manner as silver nanowire dispersion liquid 1, except that the amount of isopropyl alcohol added was increased compared to silver nanowire dispersion liquid 1, and the viscosity was set to 0.008 Pa·s.

[0230] (Silver nanowire dispersion 3) Silver nanowire dispersion liquid 3 was obtained in the same manner as silver nanowire dispersion liquid 1, except that the amount of isopropyl alcohol added was reduced compared to silver nanowire dispersion liquid 1, and the viscosity was set to 30 Pa·s.

[0231] <Preparation of composition for electrical insulation layer> The components were blended to obtain the composition shown below, thereby obtaining a composition 1 for an electrical insulating layer. (Electrical insulating layer composition 1) Dipentaerythritol hexaacrylate (DPHA): 100 parts by weight Polymerization initiator (product name "Omnirad184", manufactured by IGM Resins BV): 4.0 parts by mass

[0232] <Preparation of Resin Composition> The components were mixed to obtain the following resin composition. (Resin composition 1) Dipentaerythritol hexaacrylate (DPHA): 100 parts by weight Polymerization initiator (product name "Omnirad184", manufactured by IGM Resins BV): 4.0 parts by mass Methyl isobutyl ketone (MIBK): 500 parts by weight

[0233] (Resin composition 2) Dipentaerythritol hexaacrylate (DPHA): 100 parts by weight Polymerization initiator (product name "Omnirad184", manufactured by IGM Resins BV): 4.0 parts by mass Methyl isobutyl ketone (MIBK): 2000 parts by weight

[0234] <Preparation of Composition for High Refractive Index Layer> The components were blended so as to obtain the composition shown below, thereby obtaining a composition 1 for a high refractive index layer. (Composition 1 for high refractive index layer) Dipentaerythritol hexaacrylate (DPHA): 14 parts by weight Zirconium oxide microparticle dispersion (dispersion of zirconium oxide microparticles with an average particle size of 10 to 15 nm dispersed in methyl isobutyl ketone (solid content 32.5%)): 69 parts by mass Polymerization initiator (product name "Omnirad127", manufactured by IGM Resins BV): 1.0 part by mass Methyl isobutyl ketone (MIBK): 1000 parts by weight

[0235] <Preparation of composition for low refractive index layer> The components were blended so as to obtain the composition shown below, thereby obtaining a composition 1 for a low refractive index layer. (Low refractive index layer composition 1) Dipentaerythritol hexaacrylate (DPHA) (product name "KAYARAD DPHA", manufactured by Nippon Kayaku Co., Ltd.): 3.5 parts by mass Solid silica microparticle dispersion (a dispersion of solid silica microparticles with an average particle size of 10 to 15 nm dispersed in methyl isobutyl ketone (solid content 30%)): 21.7 parts by mass Polymerization initiator (product name "Omnirad127", manufactured by IGM Resins BV): 0.7 parts by mass Methyl isobutyl ketone (MIBK): 1000 parts by weight

[0236] Example 1 First, a 48 μm thick polyethylene terephthalate film (trade name "Cosmoshine (registered trademark) A4100", manufactured by Toyobo Co., Ltd.) having a base layer on one side was prepared as a substrate. On the untreated side of this polyethylene terephthalate film, silver nanowires were arranged using silver nanowire dispersion 1 in regions where a first conductive section having a plurality of first electrode sections arranged in a first direction and wiring sections electrically connecting adjacent first electrode sections, and a plurality of second electrode sections spaced apart from the first conductive section and arranged in a second direction perpendicular to the first direction, were to be formed. Specifically, first, using a dispenser capable of discharging silver nanowire dispersion, silver nanowire dispersion 1 was applied in the shape of the first conductive section and the shape of the second electrode sections to form a coating film. The coating was then dried by passing dry air at 40°C at a flow rate of 0.5 m / s for 15 seconds, followed by passing dry air at 70°C at a flow rate of 15 m / s for 30 seconds to evaporate the solvent in the coating. This resulted in silver nanowires being arranged on the surface of the polyethylene terephthalate film in the areas where the first conductive part and second electrode part were to be formed, forming silver nanowire patterns.

[0237] After arranging the silver nanowires, a silver paste (product name "DW-520H-14", manufactured by Toyobo Co., Ltd.) was applied using a dispenser to the silver nanowires that would become the first electrode portions at the ends of the multiple first electrode portions aligned in the first direction. Next, the silver paste was heated at 130°C for 30 minutes to harden the silver paste, thereby forming an extraction wiring portion.

[0238] After forming the extraction wiring portion, the composition for an electrical insulating layer was applied using a dispenser to the silver nanowires in the region where the wiring portion of the first conductive portion was to be formed, to form a coating film. Next, dry air at 50°C was circulated through the formed coating film at a flow rate of 0.5 m / s for 15 seconds, and then dry air at 70°C was circulated at a flow rate of 10 m / s for 30 seconds to dry the coating film, thereby evaporating the solvent in the coating film, and ultraviolet light was applied at an integrated light dose of 100 mJ / cm. 2 The coating was cured by irradiating the coating with light so that the temperature was 100° C. to 120° C., thereby forming an electrical insulating layer having a size of 1 mm×2 mm, a film thickness of 300 nm, and a refractive index of 1.50.

[0239] After forming the electrical insulating layer, a coating was formed by using a dispenser capable of dispensing silver nanowire dispersion to apply silver nanowire dispersion 1 in the shape of the bridge wiring portion, which straddles the wiring portion and electrically connects adjacent second electrode portions, to a three-dimensional surface consisting of the surface of the electrical insulating layer and the surface of the silver nanowire pattern in an area where the second electrode portion should be formed, in a second direction perpendicular to the first direction while controlling the distance between the dispenser's discharge portion and the surface of the electrical insulating layer and the silver nanowire pattern. This application of silver nanowire dispersion 1 was carried out under the following conditions. (Discharge conditions) Discharge pressure: 5kPa ·Discharge port diameter: 100μm Coating gap: 50μm PET film moving speed: 1mm / sec

[0240] The coating was then dried by passing dry air at 40°C at a flow rate of 0.5 m / s for 15 seconds, followed by passing dry air at 70°C at a flow rate of 15 m / s for 30 seconds to evaporate the solvent in the coating, thereby arranging silver nanowires in the areas where the bridge wiring was to be formed, and forming a silver nanowire pattern.

[0241] After arranging the silver nanowires in the region where the bridge wiring portion was to be formed, resin composition 1 was applied using a die coater so as to cover the silver nanowires arranged in the region where the first electrode portion, the second electrode portion, and the bridge wiring portion were to be formed, forming a coating film. Next, dry air at 50°C was circulated through the formed coating film at a flow rate of 0.5 m / s for 15 seconds, and then dry air at 70°C was circulated at a flow rate of 10 m / s for 30 seconds to dry the film, thereby evaporating the solvent in the coating film, and ultraviolet rays were irradiated at an integrated light intensity of 100 mJ / cm. 2The coating was cured by irradiating the coating with light at a rate of 1000 nm to form a resin layer with a thickness of 1000 nm and a refractive index of 1.50. This resulted in a sensor having a first conductive part having a first electrode part and wiring part made of a resin part and silver nanowires disposed in the resin part, a second electrode part made of a resin part and silver nanowires disposed in the resin part, and a second conductive part having a bridge wiring part made of a resin part and silver nanowires disposed in the resin part.

[0242] The shape of the first electrode section in the sensor of Example 1 was the shape shown in FIG. 1, and the width W1 of the first electrode section was 4 mm. The shape of the wiring section was strip-shaped, and the refractive index of the wiring section was 1.50. The width W2 of the wiring section was 1 mm, and the length of the wiring section was 0.5 mm. The shape of the second electrode section was the shape shown in FIG. 1, and the width W3 of the second electrode section was 4 mm. The thickness of the silver nanowire patterns constituting the first electrode section, wiring section, and second electrode section was each 100 nm. The shape of the bridge wiring section was strip-shaped, and the refractive index of the bridge wiring section was 1.50. The width W4 of the bridge wiring section was 0.5 mm, the length of the bridge wiring section was 3 mm, and the thickness T3 of the bridge wiring section was 1 μm.

[0243] The thickness of each part or layer was measured at 10 random locations on a cross-sectional photograph of the conductive part taken using a scanning transmission electron microscope (STEM), and the arithmetic mean value of the thicknesses at 8 locations, excluding the maximum and minimum values, was used.

[0244] Specific cross-sectional photographs were taken using the following method. First, a sample for cross-sectional observation was prepared from the sensor. Specifically, a 2 mm × 5 mm sample was cut from the sensor, placed in a silicone-based embedding plate, and epoxy resin was poured into the sample. The entire sample was embedded in the resin. The embedding resin was then left at 65°C for 12 hours or more to harden. Ultrathin sections were then prepared using an ultramicrotome (product name "Ultramicrotome EM UC7" manufactured by Leica Microsystems) with a feed thickness set to 100 nm. The prepared ultrathin sections were then collected using a collodion-coated mesh (150) to serve as STEM samples. Cross-sectional photographs of the STEM samples were then taken using a scanning transmission electron microscope (STEM) (product name "S-4800 (TYPE2)" manufactured by Hitachi High-Technologies Corporation). When taking this cross-sectional photograph, the detector (selection signal) was set to "TE," the acceleration voltage was set to 30 kV, and the emission was set to "10 μA." The magnification was adjusted appropriately from 5,000x to 200,000x while adjusting the focus and observing whether the contrast and brightness of each layer could be distinguished. A preferred magnification is 10,000x to 50,000x, and more preferably 25,000x to 40,000x. Since increasing the magnification too much makes the interface pixelated and difficult to distinguish, it is best not to increase the magnification too much when measuring the thickness of the wall portion. Furthermore, when taking the cross-sectional photograph, the beam monitor aperture was set to 3, the objective lens aperture was set to 3, and the WD was set to 8 mm. The thickness of each portion and each layer was measured using this method not only in Example 1 but also in all subsequent Examples and Comparative Examples.

[0245] The refractive index of each part was determined by cutting out one piece from each part at any five locations, measuring the refractive index of each of the five pieces using the Becke method, and calculating the arithmetic mean value of the refractive index of three pieces excluding the maximum and minimum values ​​of the five measured pieces. The refractive index of each part was measured using this method not only in Example 1 but also in all subsequent Examples and Comparative Examples. In Table 1, the "BW" in the "Refractive Index Difference" column represents the refractive index of the bridge wiring portion, and "EL" represents the refractive index of the electrical insulation layer.

[0246] <Example 2> In Example 2, a sensor was obtained in the same manner as in Example 1, except that the width W4 of the bridge wiring portion was set to 0.8 mm.

[0247] Example 3 In Example 3, a sensor was obtained in the same manner as in Example 1, except that the width W4 of the bridge wiring portion was set to 0.35 mm. Example 4 In Example 4, a sensor was obtained in the same manner as in Example 1, except that the width W4 of the bridge wiring portion was set to 0.1 mm.

[0248] <Example 5> First, a 48 μm thick polyethylene terephthalate film (trade name "Cosmoshine (registered trademark) A4100", manufactured by Toyobo Co., Ltd.) having a primer layer on one side was prepared as a substrate, and silver nanowire dispersion 1 was applied to the entire untreated surface of this polyethylene terephthalate film using a bar coater to form a coating film. Thereafter, dry air at 40°C was circulated through the formed coating film at a flow rate of 0.5 m / s for 15 seconds, and then dry air at 70°C was circulated at a flow rate of 15 m / s for 30 seconds to dry the coating film and evaporate the solvent in the coating film. As a result, silver nanowires were disposed over the entire untreated surface of the polyethylene terephthalate film.

[0249] After arranging the silver nanowires, resin composition 2 was applied using a die coater so as to cover the silver nanowires, forming a coating film. Next, dry air at 50°C was circulated through the formed coating film at a flow rate of 0.5 m / s for 15 seconds, and then dry air at 70°C was circulated at a flow rate of 10 m / s for 30 seconds to dry the film, thereby evaporating the solvent in the coating film, and ultraviolet rays were irradiated at an integrated light intensity of 100 mJ / cm. 2 The coating was cured by irradiating the coating with light so that a resin part with a thickness of 100 nm and a refractive index of 1.6 was formed. This resulted in the formation of a conductive layer containing the resin part and the silver nanowires.

[0250] After forming the conductive layer, a silver paste (product name "DW-520H-14", manufactured by Toyobo Co., Ltd.) was applied by screen printing to the surface of the resin part on the region that would become the first conductive part. The silver paste was then heated at 130°C for 30 minutes to harden.

[0251] Thereafter, laser light was irradiated under the following conditions to areas of the hardened silver paste other than the area where the extracting wiring portion was to be formed, and to areas of the conductive layer other than the areas where the first conductive portion and the second electrode portion were to be formed, thereby patterning the hardened silver paste and the conductive layer. Note that when laser light was irradiated to areas of the hardened silver paste other than the area where the extracting wiring portion was to be formed, the silver paste present in these areas was sublimated and removed. As a result, an extracting wiring portion of the same shape and dimensions as the extracting wiring portion in Example 1 was formed. (Laser light irradiation conditions) Type: YVO4 ·Wavelength: 1064nm Pulse width: 8~10ns Frequency: 100kHz Spot diameter: 30 μm Pulse energy: 16μJ ·Processing speed: 1200mm / s

[0252] After forming the extraction wiring portion, the composition for an electrical insulating layer was applied to the area of ​​the conductive layer where the wiring portion was to be formed using a dispenser to form a coating film. Next, dry air at 50°C was circulated through the formed coating film at a flow rate of 0.5 m / s for 15 seconds, and then dry air at 70°C was circulated at a flow rate of 10 m / s for 30 seconds to dry the coating film, thereby evaporating the solvent in the coating film, and ultraviolet rays were irradiated at an integrated light dose of 100 mJ / cm. 2 The coating was cured by irradiating the coating with light so that an electrical insulating layer having a size of 1 mm×2 mm, a film thickness of 500 nm, and a refractive index of 1.50 was formed.

[0253] After forming the electrical insulating layer, a silver nanowire dispersion liquid 1 was applied to the area where the bridge wiring was to be formed on the three-dimensional surface consisting of the surface of the electrical insulating layer and the surface of the silver nanowire pattern in the area where the second electrode was to be formed, in a second direction perpendicular to the first direction, using a dispenser capable of dispensing silver nanowire dispersion liquid, to form a coating film. The coating film was then dried by passing dry air at 40°C at a flow rate of 0.5 m / s for 15 seconds, followed by passing dry air at 70°C at a flow rate of 15 m / s for 30 seconds to evaporate the solvent in the coating film. This resulted in the placement of silver nanowires in the area where the bridge wiring was to be formed, forming a silver nanowire pattern.

[0254] After arranging the silver nanowires in the region where the bridge wiring portion was to be formed, resin composition 1 was applied using a die coater so as to cover the silver nanowires arranged in the region where the first electrode portion, the second electrode portion, and the bridge wiring portion were to be formed, forming a coating film. Next, dry air at 50°C was circulated through the formed coating film at a flow rate of 0.5 m / s for 15 seconds, and then dry air at 70°C was circulated at a flow rate of 10 m / s for 30 seconds to dry the film, thereby evaporating the solvent in the coating film, and ultraviolet rays were irradiated at an integrated light intensity of 100 mJ / cm. 2 The coating was cured by irradiating the coating with light at a rate of 1000 nm to form a resin layer with a thickness of 1000 nm and a refractive index of 1.50. This resulted in a sensor having a first conductive part having a first electrode part and wiring part made of a resin part and silver nanowires disposed in the resin part, a second electrode part made of a resin part and silver nanowires disposed in the resin part, and a second conductive part having a bridge wiring part made of a resin part and silver nanowires disposed in the resin part.

[0255] The first conductive section having the first electrode section and wiring section in the sensor according to Example 5 had the same shape and dimensions as the first conductive section having the first electrode section and wiring section in Example 1, and the second electrode section had the same shape and dimensions as the second electrode section in Example 1. The bridge wiring section in the sensor according to Example 5 had a strip shape and the refractive index of the wiring section was 1.50. The width W4 of the bridge wiring section was 0.5 mm, the length of the bridge wiring section was 3 mm, and the thickness T3 of the bridge wiring section was 1 μm.

[0256] Example 6 In Example 6, a sensor was obtained in the same manner as in Example 1, except that silver nanowires were arranged in the region where the bridge wiring portion was to be formed by the following process. First, a contact-type dispenser (product name "SuperΣ (registered trademark) CMIII", manufactured by Musashi Engineering Inc.) was used to apply silver nanowire dispersion 1 in a line shape onto the surface of the electrical insulating layer under the following conditions, from the discharge portion of the dispenser so that the line thickness upon application was 182 μm, thereby forming a linear coated portion. (Discharge conditions) Discharge pressure: 5kPa ·Discharge port diameter: 100μm Coating gap: 50μm PET film moving speed: 20mm / sec

[0257] The coated area was then dried by passing dry air at 40°C at a flow rate of 0.5 m / s for 15 seconds, followed by passing dry air at 70°C at a flow rate of 15 m / s for 30 seconds to evaporate the solvent in the coated area. This resulted in silver nanowires being positioned in the area where the bridge wiring was to be formed. The shape, width W4, and length of the bridge wiring of the sensor of Example 6 were the same as those of Example 1.

[0258] Example 7 In Example 7, a sensor was obtained in the same manner as in Example 1, except that silver nanowires were disposed in the region where the first conductive portion and the second electrode portion were to be formed by the following process. First, on the untreated surface of the polyethylene terephthalate film, a first conductive portion having a plurality of first electrode portions arranged in a first direction and wiring portions electrically connecting adjacent first electrode portions, and a plurality of second electrode portions spaced from the first conductive portion and arranged in a second direction perpendicular to the first direction, were to be formed. Wall composition 1 (product name "U-403B", manufactured by Chemitech Corporation) was applied by flexographic printing to form a coating film on both sides of the region. Then, dry air at 40°C was circulated through the formed coating film at a flow rate of 0.5 m / s for 15 seconds, and then dry air at 70°C was circulated at a flow rate of 15 m / s for 30 seconds to dry the coating, thereby evaporating the solvent in the coating film. Then, ultraviolet light was applied to the coating film at an integrated light intensity of 100 mJ / cm. 2 The coating was cured by irradiating the coating with light so that a plurality of electrically insulating wall portions having the shape shown in Fig. 13 were formed. The width of the wall portion was 30 µm, and the thickness of the wall portion was 1 µm.

[0259] After forming multiple wall portions, the spaces between the walls were filled with silver nanowire dispersion 1 using an inkjet method to form a coating film. Dry air at 40°C was then circulated through the formed coating film at a flow rate of 0.5 m / s for 15 seconds, followed by dry air at 70°C at a flow rate of 15 m / s for 30 seconds to evaporate the solvent in the coating film. This resulted in silver nanowires being positioned on the surface of the polyethylene terephthalate film in the areas where the first conductive portion and second electrode portion were to be formed.

[0260] The wall width was measured at 10 random locations on a cross-sectional photograph of the wall taken using a scanning transmission electron microscope (STEM). The arithmetic mean value of the widths at eight locations, excluding the maximum and minimum values, was used. The cross-sectional photographs were taken using the following method. First, a sample for cross-sectional observation was prepared from the conductive film. Specifically, a sensor cut into a 2 mm × 5 mm size was placed in a silicone-based embedding plate, and epoxy resin was poured into it to embed the entire sensor in the resin. The embedding resin was then left to harden at 65°C for at least 12 hours. Ultrathin sections were then prepared using an ultramicrotome (product name: "Ultramicrotome EM UC7" manufactured by Leica Microsystems) with a feed thickness of 100 nm. The prepared ultrathin sections were then cut using a collodion-coated mesh (150) to serve as STEM samples. Subsequently, a cross-sectional photograph of the STEM sample was taken using a scanning transmission electron microscope (STEM) (product name "S-4800 (TYPE2)" manufactured by Hitachi High-Technologies Corporation). When taking these cross-sectional photographs, the detector (selection signal) was set to "TE," the acceleration voltage was set to 30 kV, and the emission was set to "10 μA." The magnification was adjusted appropriately from 5,000 to 200,000 times while adjusting the focus and observing the contrast and brightness to see whether each layer could be distinguished. A preferred magnification is 10,000 to 50,000 times, and more preferably 25,000 to 40,000 times. Since increasing the magnification too much results in coarse pixels at the interface, making it difficult to distinguish, it is best not to increase the magnification too much when measuring the wall thickness. When taking the cross-sectional photographs, the beam monitor aperture was set to 3, the objective lens aperture was set to 3, and the WD was set to 8 mm.

[0261] The thickness of the wall was measured at 10 random locations on a cross-sectional photograph of the wall taken using a scanning transmission electron microscope (STEM), and the arithmetic mean value of the thicknesses at 8 locations, excluding the maximum and minimum values, was used as the wall thickness. The cross-sectional photograph used to measure the wall thickness was taken under the same conditions as the cross-sectional photograph used to measure the wall width.

[0262] The shapes and widths of the first electrode portion, wiring portion, and second electrode portion in the sensor of Example 7 were similar to those of the first electrode portion, wiring portion, and second electrode portion in Example 1.

[0263] <Comparative Example 1> The sensor of Comparative Example 1 was obtained in the same manner as in Example 1, except that the process of disposing silver nanowires in the region where the bridge wiring portion was to be formed and the subsequent processes were performed as follows. Specifically, a 30-nm-thick tin-doped indium oxide (ITO) layer was formed on the surface of the electrical insulation layer by sputtering. After the ITO layer was formed, it was heated at 150°C for 30 minutes to crystallize the ITO layer. The ITO layer was then patterned using photolithography. This resulted in the formation of a bridge wiring portion made of ITO with a refractive index of 2.00, measuring 0.1 mm in width, 3 mm in length, and 30 nm in thickness.

[0264] After the bridge wiring portion was formed, resin composition 1 was applied using a die coater so as to cover the silver nanowires arranged in the region where the first electrode portion and the second electrode portion were to be formed, as well as the bridge wiring portion, to form a coating film. Next, dry air at 50°C was circulated through the formed coating film at a flow rate of 0.5 m / s for 15 seconds, and then dry air at 70°C was circulated at a flow rate of 10 m / s for 30 seconds to dry the film, thereby evaporating the solvent in the coating film, and ultraviolet light was applied to the film at an integrated light intensity of 100 mJ / cm. 2 The coating was cured by irradiating the coating with light so that the thickness was 100 nm, forming a resin layer with a refractive index of 1.6. This resulted in the formation of a first conductive part having a first electrode part and wiring part made of a resin part and silver nanowires arranged in the resin part, and a second conductive part having a second electrode part made of a resin part and silver nanowires arranged in the resin part, and a bridge wiring part made of ITO.

[0265] Thereafter, composition 1 for a high refractive index layer was applied to the surface of the resin layer to form a coating film. The formed coating film was then dried at 70°C for 30 seconds, and then cured by ultraviolet irradiation at an integrated light dose of 150 mJ / cm2 to form a high refractive index layer with a film thickness of 50 nm. Next, composition 1 for a low refractive index layer was applied to the high refractive index layer to form a coating film. This coating film was then dried at 70°C for 30 seconds, and then cured by ultraviolet irradiation at an integrated light dose of 150 mJ / cm2. 2 The resulting resin was cured by irradiating it with ultraviolet light at a temperature of 1.66 to form a low refractive index layer with a thickness of 20 nm. This resulted in a reflection-reducing layer consisting of a high refractive index layer with a refractive index of 1.66 and a low refractive index layer with a refractive index of 1.48, and a sensor was obtained.

[0266] <Comparative Example 2> In Comparative Example 2, an attempt was made to fabricate a sensor in the same manner as in Example 1, except that Silver Nanowire Dispersion Liquid 2 was used instead of Silver Nanowire Dispersion Liquid 1. However, because the viscosity of Silver Nanowire Dispersion Liquid 2 was too low, Silver Nanowire Dispersion Liquid 2 ran off the three-dimensional surface, and it was not possible to form a silver nanowire pattern for the bridge wiring portion.

[0267] <Comparative Example 3> In Comparative Example 3, an attempt was made to fabricate a sensor in the same manner as in Example 1, except that Silver Nanowire Dispersion Liquid 3 was used instead of Silver Nanowire Dispersion Liquid 1. However, because the viscosity of Silver Nanowire Dispersion Liquid 3 was too high, the silver nanowire dispersion liquid 3 clogged when it was ejected, and a silver nanowire pattern could not be formed.

[0268] <Flexibility evaluation> (1) Evaluation of the electrical resistance ratio before and after the folding test (FD test) A folding test was conducted to evaluate the flexibility of the sensors according to Examples 1 to 7 and Comparative Example 1. Specifically, first, rectangular samples 1 and 2 measuring 125 mm in length and 50 mm in width were cut out from the sensor. Sample 1 was cut out so that the longitudinal direction of Sample 1 was the first direction, and Sample 2 was cut out so that the longitudinal direction of Sample 2 was the second direction.

[0269] After cutting out Samples 1 and 2 from the sensor, silver paste (product name "DW-520H-14" manufactured by Toyobo Co., Ltd.) was applied to both ends of the longitudinal surface of each of Samples 1 and 2, measuring 10 mm x 50 mm. The samples were then heated at 130°C for 30 minutes to form hardened silver paste at both ends. The electrical resistance of Samples 1 and 2, which had hardened silver paste at both ends, was measured over a distance of 105 mm and a width of 50 mm. The hardened silver paste was then irradiated with laser light under the following conditions. For Sample 1, a portion of the silver paste was removed to prevent electrical conduction between the first conductive portion and the second electrode portion, as shown in FIG. 6. For Sample 2, a portion of the silver paste was removed to prevent electrical conduction between the second conductive portion and the first electrode portion, as shown in FIG. 7. (Laser light irradiation conditions) Type: YVO4 ·Wavelength: 1064nm Pulse width: 8~10ns Frequency: 100kHz Spot diameter: 30 μm Pulse energy: 16μJ ·Processing speed: 1200mm / s

[0270] The electrical resistance values ​​of Samples 1 and 2 were measured using a tester (product name "Digital MΩ Hitester 3454-11" manufactured by Hioki E.E. Corporation). Specifically, the Digital MΩ Hitester 3454-11 has two probe terminals (a red probe terminal and a black probe terminal, both pin-shaped). For Sample 1, the red probe terminal was brought into contact with a portion of the hardened silver paste at one end that contacted the first conductive portion, and the black probe terminal was brought into contact with a portion of the hardened silver paste at the other end that contacted the first conductive portion, to measure the electrical resistance value. For Sample 2, the red probe terminal was brought into contact with a portion of the hardened silver paste at one end that contacted the second conductive portion, and the black probe terminal was brought into contact with a portion of the hardened silver paste at the other end that contacted the second conductive portion, to measure the electrical resistance value.

[0271] Thereafter, the short sides (50 mm) of the selected sample were fixed to a U-shaped stretch tester (product name "DLDMLH-FS", manufactured by Yuasa System Co., Ltd.) as a folding durability tester, with the short sides (50 mm) fixed to each other and the sample attached so that the minimum distance between the two opposing sides was 3 mm (outer diameter of the bent part: 3.0 mm) as shown in Figure 8(C), and a test was performed in which the conductive part side of the sample was folded 180 degrees (a test in which the first conductive part was folded on the inside and the base material was folded on the outside: an inward bending folding test) 100,000 times under the following conditions. (Folding conditions) Reciprocating speed: 80 rpm (revolutions per minute) Test stroke: 60mm Flexion angle: 180°

[0272] After the folding test, the electrical resistance value of the first conductive portion and the electrical resistance value of the second conductive portion were measured for the sample after the folding test in the same manner as for the sample before the folding test. Then, the electrical resistance value ratio (electrical resistance value of sample 1 after folding test / electrical resistance value of sample 1 before folding test), which is the ratio of the electrical resistance value of sample 1 after the folding test to the electrical resistance value of sample 1 before the folding test, was determined. In addition, the electrical resistance value ratio (electrical resistance value of sample 2 after folding test / electrical resistance value of sample 2 before folding test), which is the ratio of the electrical resistance value of sample 2 after the folding test to the electrical resistance value of sample 2 before the folding test, was determined.

[0273] In addition, new samples 1 and 2 cut from the sensors according to Examples 1 to 7 in the same manner as above were attached to the durability tester in the same manner as above, and a test was performed in which the substrate-side surface of the sample was folded 180° (a test in which the first conductive part was folded on the outside and the substrate was folded on the inside: an outward bending folding test) 100,000 times. In the same manner, the electrical resistance of the first conductive part of sample 1 after the folding test was measured to determine the electrical resistance ratio. In addition, the electrical resistance of the second conductive part of sample 2 after the folding test was measured to determine the electrical resistance ratio. The results of the folding test were evaluated according to the following criteria. The electrical resistance ratio was measured five times at different locations, and the arithmetic mean value of the three electrical resistance ratios excluding the maximum and minimum values ​​was used. A: In all folding tests, the electrical resistance ratio was 1.5 or less. B: In all folding tests, the electrical resistance ratio was greater than 1.5 and less than or equal to 3. C: In any of the folding tests, the electrical resistance ratio exceeded 3.

[0274] (2) Evaluation of fold creases after folding test The appearance of the sensors according to Examples 1 to 7 after the folding test was observed to evaluate whether or not a crease had occurred at the bent portion of the sensor. The folding test was performed according to the method described in the section on the evaluation of the electrical resistance ratio before and after the folding test. The crease observation was performed visually in an environment with a temperature of 23°C and a relative humidity of 50%. The crease observation was performed in a bright room with white lighting (800 lux to 2000 lux), and the bent portion was thoroughly observed using transmitted and reflected light. Both the inside and outside portions of the bent portion when folded were also observed. To easily identify the positions to be observed, the sample before the folding test was placed on the fixing section of a durability tester. When folded once, marks indicating the bent portion were made with an oil-based pen on both ends of the bent portion located perpendicular to the folding direction, as shown in FIG. 8. After the folding test, the sensor was removed from the durability tester and a line connecting the marks at both ends of the bent portion was drawn with an oil-based pen. The crease was observed by visually observing the entire bent portion, which was the area formed by the marks at both ends of the bent portion and the line connecting these marks. The area that would become the bent portion of each sensor before the folding test was observed and no crease was observed. The evaluation criteria were as follows: A: No creases were observed in the sensor after any of the folding tests. B: After each folding test, slight creases were observed in the sensor, but were at a level that would not cause any problems in practical use. C: After any of the folding tests, creases were clearly observed on the sensor.

[0275] (3) Microcrack (MC) evaluation after folding test The appearance of the sensors according to Examples 1 to 7 after the folding test was observed to evaluate whether microcracks had occurred at the bent portions of the sensor. The folding test was performed according to the method described in the section on the evaluation of the electrical resistance ratio before and after the folding test. Microcrack observation was performed using a digital microscope (product name "VHX-5000", manufactured by Keyence Corporation) in an environment of 23°C temperature and 50% relative humidity. Specifically, the sample after the folding test was first slowly unfolded and fixed to the microscope stage with tape. If the fold was strong, the observation area was made as flat as possible. However, the area to be observed near the center of the sample (the bent portion) was not touched with the hands, and only to the extent that no force was applied. Next, both the inner and outer portions of the folded sample were observed. Microcrack observation was performed using a ring light as the illumination for the digital microscope at 200x magnification, in dark field and reflected light. To observe microcracks, the sample before the folding test was placed on the fixed part of the durability tester to easily identify the observation position. When folded once, marks indicating the bent portion were made with an oil-based pen on both ends of the bent portion located in a direction perpendicular to the folding direction, as shown in Figure 9. After the folding test, the sample was removed from the durability tester and a line connecting the marks on both ends of the bent portion was drawn with an oil-based pen. The microscope was positioned so that the center of the microscope's field of view was centered on the bent portion. When the bent portion of each sensor was observed before the folding test, no microcracks were observed. The evaluation criteria were as follows: A: No microcracks were observed in the sensor after any of the folding tests. B: After any of the folding tests, some microcracks were observed in the sensor, but the level was not problematic for practical use. C: Microcracks were clearly observed on the sensor after both folding tests.

[0276] <Evaluation of visibility of bridge wiring> The sensors according to Examples 1 to 7 and Comparative Example 1 were evaluated for whether the shape of the bridge wiring portion was visible. Specifically, a sample measuring 100 mm × 100 mm was first cut out from the sensor. Then, in an indoor environment of 1200 Lux, this sample was placed with the bridge wiring portion facing upward, and whether the shape of the bridge wiring portion was visible was evaluated by visual observation under a white LED light (model number "Reach-18A", manufactured by Prime Star Co., Ltd.). Visual observation was performed from all angles (-180° to 180°) with the normal direction of the sensor as the reference (0°). Fifteen observers were employed, and if all observers could see the shape of the bridge wiring portion, it was determined that the shape of the bridge wiring portion was visible. The evaluation criteria were as follows: A: The shape of the bridge wiring portion was not visible. B: The shape of the bridge wiring portion was visible.

[0277] <Haze value measurement> For the sensors according to Examples 1 to 7 and Comparative Example 1, the haze value (total haze value) of the sensor was measured in accordance with JIS K7136:2000 using a haze meter (product name "HM-150", manufactured by Murakami Color Research Laboratory Co., Ltd.) under an environment of 23°C temperature and 50% relative humidity. The haze value was measured for the entire sensor. A sample measuring 50 mm x 100 mm was cut out from the sensor, and the sample was placed with the first conductive part facing away from the light source, without curls or wrinkles and without fingerprints or dust. The haze value was measured five times for each sample, and the arithmetic mean of the three haze values ​​excluding the maximum and minimum values ​​was calculated.

[0278] <Silver nanowire arrangement and evaluation> The sensors according to Examples 1 and 6 were evaluated for whether the silver nanowires in the bridge wiring portion were aligned along the second direction. Specifically, a sample measuring 5 mm x 5 mm was first cut out from the sensor. Then, using the SEM function of a scanning transmission electron microscope (product name "S-4800 (TYPE 2)", manufactured by Hitachi High-Technologies Corporation), 10 photographs of the bridge wiring portion of the sample were taken at magnifications of 1000 to 6000 times. The orientation angle and orientation strength were calculated for each photograph of the bridge wiring portion using the surface fiber orientation analysis program (V.8.03) described above. In the bridge wiring section, if the orientation angle of the silver nanowires was within 0°±10° and the orientation strength was 1.2 or more, the silver nanowires were deemed to be aligned in the second direction, and if the orientation angle was within 0°±10° but the orientation strength was less than 1.2, or if the orientation angle was 1.2 or more but the orientation angle exceeded 0°±10°, or if the orientation angle exceeded 0°±10° and the orientation strength was less than 1.2, the silver nanowires were deemed not to be aligned in the direction in which the bridge wiring section extended. The evaluation criteria were as follows: A: The silver nanowires in the bridge wiring section were aligned along the second direction. B: The silver nanowires in the bridge wiring portion were not aligned along the second direction.

[0279] <Electrical short circuit evaluation> The sensors according to Examples 1 and 7 were evaluated for electrical short-circuiting. Specifically, first, samples measuring 50 mm × 50 mm were cut from the sensor along the first and second directions. Then, a tester (product name: "Digital MΩ Hitester 3454-11," manufactured by Hioki E.E. Corporation) was used to evaluate whether a current flowed between the first conductive part and the second conductive part adjacent to the first conductive part. A durability test was then conducted in which a voltage of 32 V was applied to the first conductive part of the sample for 100 hours in an environment of 65°C and 95% relative humidity. After the durability test, a tester (product name: "Digital MΩ Hitester 3454-11," manufactured by Hioki E.E. Corporation) was used to evaluate whether a current flowed between the first conductive part and the second conductive part adjacent to the first conductive part, thereby evaluating whether an electrical short-circuit occurred. The evaluation criteria were as follows: A: No current flowed between the first conductive part and the second conductive part not only before the durability test but also after the durability test. B: Before the durability test, no current flowed between the first conductive part and the second conductive part, and after the durability test, a small amount of current flowed between the first conductive part and the second conductive part, but this was at a level that did not cause any problems in practical use. C: Before the durability test, no current flowed between the first conductive part and the second conductive part, but after the durability test, a current flowed between the first conductive part and the second conductive part.

[0280] <3D surface tracking evaluation> In Examples 1 to 7, the silver nanowire pattern of the bridge wiring portion was evaluated for conformity to the three-dimensional surface consisting of the surface of the electrical insulating layer and the surface of the silver nanowire pattern of the second electrode portion. The conformity evaluation was determined from cross-sectional photographs taken using a scanning transmission electron microscope (STEM) and linear resistance measurements. Specifically, if the silver nanowire pattern of the bridge wiring portion conformed to the three-dimensional surface and the linear resistance was 1,000,000 Ω or less, the silver nanowire pattern of the bridge wiring portion was deemed to conform to the three-dimensional surface. If the silver nanowire pattern of the bridge wiring portion did not conform to the three-dimensional surface and the linear resistance was greater than 1,000,000 Ω, the silver nanowire pattern of the bridge wiring portion was deemed not to conform to the three-dimensional surface. Whether the silver nanowire pattern of the bridge wiring portion conformed to the three-dimensional surface was determined from cross-sectional photographs taken using a scanning transmission electron microscope (STEM). The conditions for taking the cross-sectional photographs using the scanning transmission electron microscope were the same as those for taking the cross-sectional photographs described in Example 1. For the linear resistance measurement, first, a sample similar to that used in the folding test was prepared. After obtaining the sample, the resistance value was measured by contacting the probe terminal of a tester (product name "Digital MΩ Hitester 3454-11" manufactured by Hioki E.E. Corporation) with the cured silver paste in an environment of 23°C and 50% relative humidity. Specifically, the Digital MΩ Hitester 3454-11 is equipped with two probe terminals (a red probe terminal and a black probe terminal, both pin-shaped). The red probe terminal was contacted with the portion of one cured silver paste that was in contact with the bridge wiring portion, and the black probe terminal was contacted with the portion of the other cured silver paste that was in contact with the bridge wiring portion, to measure the resistance value. The linear resistance value of the bridge wiring portion was then calculated using the above formula (2). The evaluation criteria were as follows: A: The silver nanowire pattern of the bridge wiring section followed the three-dimensional surface. B: The silver nanowire pattern in the bridge wiring section did not follow the three-dimensional surface.

[0281] <Static electricity evaluation> The sensors according to Examples 1 to 7 were subjected to static electricity evaluation of the bridge wiring portion. Specifically, five samples measuring 10 mm x 150 mm were cut out from the sensor so as to include the bridge wiring portion, and then 2 kV was applied to the bridge wiring portion of each sample using an electron gun, and the presence or absence of disconnection in the bridge wiring portion was evaluated. The evaluation criteria were as follows: A: There were no breaks in any of the samples. B: No breaks were found in samples 1 to 4. C: All five samples were broken.

[0282] <Measurement of the average fiber diameter of silver nanowires in the bridge wiring part of the sensor> For the sensors according to Examples 1 to 7, the average fiber diameter of the silver nanowires contained in the bridge wiring portion was measured using a scanning transmission electron microscope (STEM, product name "S-4800," manufactured by Hitachi High-Technologies Corporation). Specifically, a sample measuring 1 mm x 10 mm was first cut from the sensor so as to include the bridge wiring portion. This was then placed in a silicone-based embedding plate, and epoxy-based resin was poured into it to embed the entire sample in the resin. The embedding resin was then left at 25°C for 12 hours or more to harden. Ultrathin sections were then prepared using an ultramicrotome (product name "Ultramicrotome EM UC7," manufactured by Leica Microsystems) with a feed thickness set to 100 nm. The prepared ultrathin sections were then collected using a collodion-coated mesh (150) to serve as STEM samples. Next, a scanning transmission electron microscope (STEM) (product name "S-4800 (TYPE2)" manufactured by Hitachi High-Technologies Corporation) was used to take cross-sectional images of the STEM sample. The detector (selection signal) was set to "TE," the acceleration voltage was set to 30 kV, and the emission was set to "10 μA." The magnification was adjusted appropriately from 5,000x to 200,000x while adjusting the focus and observing whether the individual layers could be distinguished. The beam monitor aperture was set to 3, the objective lens aperture was set to 3, and the working distance was set to 8 mm. Ten silver nanowires contained in the bridge wiring were then observed in the cross-sectional image, and the shortest diameter (minor diameter) of each silver nanowire was measured. The three smallest data points were selected from the ten data points, and the arithmetic mean was calculated using these three data points. This arithmetic mean value was used as the average fiber diameter of the silver nanowires.

[0283] <Uneven evaluation> In the sensors according to Examples 1 to 7, we investigated whether the silver nanowires in the bridge wiring section were unevenly distributed toward the polyethylene terephthalate film side of the bridge wiring section at a position halfway through the thickness of the bridge wiring section. Specifically, a sample for cross-sectional observation was first prepared from the sensor. Specifically, a 2 mm × 5 mm sample was cut from the sensor to include the bridge wiring section. The sample was placed in a silicone-based embedding plate, and epoxy-based resin was poured into it to embed the entire sample in the resin. The embedding resin was then left to harden at 65°C for 12 hours or more. Ultrathin sections were then prepared using an ultramicrotome (product name "Ultramicrotome EM UC7" manufactured by Leica Microsystems) with a feed thickness of 100 nm. The prepared ultrathin sections were then collected using a collodion-coated mesh (150 mesh) to serve as STEM samples. Next, cross-sectional photographs of the STEM sample were taken using a scanning transmission electron microscope (STEM) (product name "S-4800 (TYPE2)" manufactured by Hitachi High-Technologies Corporation). When taking these cross-sectional photographs, the detector (selection signal) was set to "TE," the acceleration voltage to "30 kV," and the emission current to "10 μA." The magnification for STEM observation was adjusted to 25,000 to 50,000 times the focus, and the contrast and brightness were appropriately adjusted so that each layer could be distinguished. Furthermore, when taking the cross-sectional photographs, the aperture was set to "beam monitor aperture 3," the objective lens aperture to "3," and the WD to "8 mm." Ten cross-sectional photographs were then prepared in this manner. Next, each cross-sectional photograph was enlarged to the pixel level, and the number of pixels in each cross-sectional photograph displaying silver nanowires located on the polyethylene terephthalate film side from a position halfway through the thickness of the bridge wiring portion and the number of pixels displaying silver nanowires located on the surface side of the bridge wiring portion from a position halfway through the thickness of the bridge wiring portion were counted, and the ratio of the number of pixels displaying silver nanowires located on the polyethylene terephthalate film side from the above-mentioned halfway position to the total number of pixels displaying silver nanowires was calculated.In addition, when a pixel in which silver nanowires were displayed spanned the above-mentioned half position, each pixel was divided into a portion present on the polyethylene terephthalate film side from the above-mentioned half position and a portion present on the surface side of the bridge wiring portion from this position, and one pixel was divided based on the area ratio of the divided portions.The above proportion obtained from each cross-sectional photograph was then taken as the abundance proportion of silver nanowires present on the polyethylene terephthalate film side from the half-thickness position of the bridge wiring portion, and the arithmetic mean of the abundance proportions obtained from each cross-sectional photograph was calculated.When this arithmetic mean value was 55% or more, it was considered to be unevenly distributed on the polyethylene terephthalate film side.The evaluation criteria were as follows. A: Silver nanowires were unevenly distributed on the polyethylene terephthalate film side from the position halfway through the thickness of the bridge wiring part. B: Silver nanowires were not unevenly distributed on the polyethylene terephthalate film side from the position halfway through the thickness of the bridge wiring portion.

[0284] The results are shown in Tables 1 and 2. The results of the electrical resistance ratios shown in Table 1 are the results when an inward bending folding test was performed, and the results of the electrical resistance ratios shown in Table 2 are the results when an outward bending folding test was performed. [Table 1]

[0285] [Table 2]

[0286] As shown in Table 1, the sensor according to Comparative Example 1 had poor flexibility because the bridge wiring was made of ITO. In contrast, the sensors according to Examples 1 to 7 had excellent flexibility and visibility because the bridge wiring included a resin part in addition to the silver nanowires.

[0287] As shown in Table 2, in the sensor according to Example 6, the silver nanowires in the bridge wiring portion were aligned along the second direction, and therefore the electrical resistance value was lower than that of Example 1. This allows the silver nanowires to be reduced from the bridge wiring portion in the sensor according to Example 6, thereby achieving desired linear resistance and surface resistance values ​​while reducing costs.

[0288] As shown in Table 2, in the sensor according to Example 4, the width of the bridge wiring portion was less than 0.35 mm, so the bridge wiring portion was broken when static electricity of 2 kV was applied. In contrast, in the sensors according to Examples 1 to 3 and 5 to 7, the width of the bridge wiring portion was 0.35 mm or more, so the bridge wiring portion was not broken even when static electricity was applied.

[0289] As shown in Table 2, in the sensor of Example 1, a small amount of current flowed between the first conductive part and the second conductive part after the durability test. This is thought to be because silver ions in the first electrode part and the second electrode part migrated and precipitated from the first electrode part and the second electrode part during the durability test. In contrast, in the sensor of Example 7, an electrically insulating wall part was formed between the first electrode part and the second electrode part. Therefore, no current flowed between the conductive parts before and after the durability test, and no electrical short circuit occurred. This is thought to be because even if silver ions in the conductive part migrated and precipitated from the first electrode part and the second electrode part during the durability test, the silver ions were blocked by the wall part. [Explanation of symbols]

[0290] 10...Sensor 11...Base material 11A…Surface 12...First conductive part 12A…1st electrode part 12B...Wiring section 13...Second conductive part 13A…Second electrode part 13B...Bridge wiring section 17...Resin layer 17A, 17B...Resin part 18A, 18B...Conductive fiber 100, 110, 130...conductor 101...Three-dimensional object 101A, 131A…3D surface 102, 132...Conductive part 102A, 132A...Conductive fiber pattern

Claims

1. A sensor comprising: a substrate; a first conductive part provided on a first surface side of the substrate; and a second conductive part provided on the first surface side of the substrate and spaced apart from the first conductive part, the first conductive portion has a plurality of first electrode portions arranged in a first direction and a wiring portion that electrically connects the first electrode portions adjacent to each other, the second conductive portion has a plurality of second electrode portions arranged in a second direction intersecting the first direction, and a bridge wiring portion that straddles the wiring portion and electrically connects adjacent second electrode portions to each other, The sensor, wherein the bridge wiring portion includes a resin portion and a conductive fiber disposed in the resin portion.

2. A sensor comprising: a substrate; a first conductive part provided on a first surface side of the substrate; and a second conductive part provided on the first surface side of the substrate and spaced apart from the first conductive part, the first conductive portion has a plurality of first electrode portions arranged in a first direction and a wiring portion that electrically connects the first electrode portions adjacent to each other, the second conductive portion has a plurality of second electrode portions arranged in a second direction intersecting the first direction, and a bridge wiring portion that straddles the wiring portion and electrically connects adjacent second electrode portions to each other, the second electrode portion includes a conductive material, The sensor, wherein the bridge wiring portion includes a resin portion and a conductive material disposed in the resin portion and the same type as the conductive material contained in the second electrode portion.

3. The sensor according to claim 2 , wherein the conductive material of the second electrode portion and the conductive material of the bridge wiring portion are conductive fibers.

4. The sensor according to claim 1 or 2, wherein the second electrode portion has a width of 10 mm or less.

5. 3. The sensor according to claim 1, wherein the width of the bridge wiring portion is 0.35 mm or more.

6. The sensor according to claim 1 or 2, wherein the first electrode portion and the wiring portion of the first conductive portion each include a conductive fiber.

7. The sensor according to claim 1 or 2, further comprising an electrical insulating layer provided between the wiring portion and the bridge wiring portion.

8. 8. The sensor according to claim 7, wherein an absolute value of the difference in refractive index between the bridge wiring portion and the electrical insulating layer is 0.08 or less.

9. An article comprising the sensor of claim 1 or 2.

10. The article of claim 9 , wherein the article is a visual display device.

11. a step of arranging first conductive fibers in regions on the first surface side of the substrate where a first conductive portion having a plurality of first electrode portions arranged in a first direction and wiring portions electrically connecting adjacent first electrode portions, and a plurality of second electrode portions spaced apart from the first conductive portion and arranged in a second direction intersecting the first direction, are to be formed; forming an electrical insulating layer so as to cover the first conductive fibers arranged in an area where the wiring portion is to be formed; arranging second conductive fibers in a region on the electrical insulation layer where a bridge wiring portion that straddles the wiring portion and electrically connects adjacent second electrode portions is to be formed; forming a resin layer covering the first conductive fibers and the second conductive fibers; A method for manufacturing a sensor comprising:

12. 12. The method for manufacturing a sensor described in claim 11, wherein the step of arranging the first conductive fiber comprises the steps of: forming a conductive layer including a resin portion and the first conductive fiber on the first surface side of the substrate; and removing at least the first conductive fiber present in an area of ​​the conductive layer other than an area where the first conductive portion and the second electrode portion are to be formed.

13. The method for manufacturing a sensor according to claim 11 , wherein the second electrode portion has a width of 10 mm or less.

14. The method for manufacturing a sensor according to claim 11, wherein the width of the bridge wiring portion is 0.35 mm or more.

15. a three-dimensional object having a three-dimensional surface; a conductive portion provided on the surface of the three-dimensional object, the conductive portion including a first conductive fiber pattern made of a plurality of conductive fibers and conforming to the shape of the three-dimensional object; A conductor comprising:

16. the three-dimensional object comprises: a base material; a first conductive portion provided on a first surface side of the base material, the first conductive portion having a plurality of first electrode portions arranged in a first direction and a wiring portion electrically connecting adjacent first electrode portions; a second conductive fiber pattern provided on the first surface side of the base material, spaced apart from the first conductive portion and arranged in a second direction intersecting the first direction, the second conductive fiber pattern being made up of a plurality of conductive fibers; and an electrical insulating layer provided on the wiring portion; the three-dimensional surface is composed of a surface of the electrical insulation layer and a surface of the second conductive fiber pattern; The conductor described in claim 15, wherein the first conductive fiber pattern is formed on the surface of adjacent second conductive fiber patterns and on the surface of the electrical insulation layer between the second conductive fiber patterns so as to straddle the wiring portion and electrically connect adjacent second conductive fiber patterns to each other.

17. A sensor comprising the electrical conductor of claim 15.

18. An article comprising the sensor of claim 17.

19. 20. The article of claim 18, wherein the article is a visual display device.

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