antenna

Abstract

The present invention provides an antenna that takes into account both low transmission loss and visual recognition. The antenna has a transparent film substrate, an antenna element disposed on one of the two surfaces of the transparent film substrate, and a grounding portion disposed on the other of the two surfaces of the transparent film substrate. The antenna element and the grounding portion are composed of a mesh pattern formed by silver fine wires, and the line width of the fine wires is greater than 1.0 μm and less than 5.0 μm. The thickness of the transparent film substrate is greater than 30 μm and less than 300 μm.

Description

Technical Field

[0001] The present invention relates to an antenna having an antenna element composed of silver thin wires, and more particularly to an antenna having both low transmission loss and visual recognition. Background Art

[0002] Currently, there are various communication systems using wireless technologies, such as mobile phones, smartphones, tablet computers, and other mobile communication terminals, Internet communications, WiFi (Wireless Fidelity), Bluetooth (registered trademark), and GPS (Global Positioning System). In order to cope with various communication systems, an antenna capable of transmitting and receiving radio waves used in each communication system is required.

[0003] And, for example, the communication standard 5G (Generation) uses frequency bands of 3.7 to 6 GHz and above 24 GHz. Since 5G uses higher frequency radio waves than before, it has the advantages of high speed, simultaneous multi-point connection and low latency. However, compared with the communication standard 4G (Generation) with a frequency band of 450 MHz to 3.6 GHz used so far, it has the characteristics of short propagation distance and strong linearity of radio waves. According to these characteristics, many base stations are required and multiple antennas need to be set in the terminal.

[0004] Since windows of buildings and display sections of mobile communication terminals serve as good radio wave openings, there is a need for a transparent antenna that can be installed in the radio wave opening and is difficult to be visually recognized.

[0005] For example, Patent Document 1 describes an antenna unit having a transparent substrate, one or more antenna conductors, and a transparent conductive film, wherein the one or more antenna conductors are provided on a first main surface side of the transparent substrate, and the transparent conductive film is provided on a second main surface side opposite to the first main surface of the transparent substrate. In Patent Document 1, the transparent substrate is made of glass.

[0006] Previous technical literature

[0007] Patent Literature

[0008] Patent Document 1: International Publication No. 2019 / 107514 Summary of the invention

[0009] Technical issues to be solved by the invention

[0010] As described above, from the perspective of being easy to install in windows of buildings and display parts of mobile communication terminals, etc., and not compromising design, landscape or display quality, a thin, flexible and highly transparent antenna is preferred. So far, as a substrate for a transparent antenna, glass or synthetic quartz can be cited as described in the above-mentioned patent document 1. From the perspective of thinness, it is necessary to thin the glass substrate. However, it is not limited to glass. When the substrate is thinned, it is sometimes necessary to narrow the width of the antenna pattern or the power supply line in order to perform impedance matching with the antenna's transceiver circuit. If a transparent conductive material such as ITO (Indium Tin Oxide: Indium Tin Oxide) is used, although impedance matching with the antenna's transceiver circuit can be achieved, the transparent conductive material has high resistance and large transmission loss. On the other hand, a mesh pattern using fine metal wires has low resistance and therefore less transmission loss. However, it is necessary to narrow the opening of the mesh pattern according to the width of the power supply line. If the opening is narrow, the transmittance decreases and becomes easy to visually recognize. In this way, there is no antenna that takes into account both low transmission loss and visual recognition.

[0011] An object of the present invention is to provide an antenna that achieves both low transmission loss and visual recognition.

[0012] Means for solving technical problems

[0013] In order to achieve the above-mentioned purpose, one embodiment of the present invention provides an antenna, which has a transparent film substrate, an antenna element arranged on one of the two surfaces of the transparent film substrate, and a grounding portion arranged on the other of the two surfaces of the transparent film substrate, the antenna element and the grounding portion are composed of a grid pattern formed by silver fine wires, the line width of the fine wires is greater than 1.0μm and less than 5.0μm, and the thickness of the transparent film substrate is greater than 30μm and less than 300μm.

[0014] It is preferred that the substrate has a power supply line provided on one surface of the transparent film substrate, the power supply line being composed of a mesh pattern formed of silver fine wires, and the line width of the fine wires being 1.0 μm or more and less than 5.0 μm.

[0015] The line width of the thin line is preferably 2.1 μm or more and 3.7 μm or less.

[0016] It is preferred that the silver thin wires contain a plurality of silver particles dispersed in a polymer, and the ratio of the plurality of silver particles contained in the silver thin wires is 70 volume % or more.

[0017] The thickness of the thin wire is preferably 0.5 μm or more and less than 5.0 μm.

[0018] When observing the transparent film substrate from one side or the other side, the surface roughness of the fine line on one side or the other side of the observation side is set to Rq(A), and the surface roughness of the transparent film substrate side of the fine line on the other side or one side opposite to the observation side is set to Rq(B), preferably satisfying 0.05μm≤Rq(A)≤0.35μm, and satisfying |Rq(B)-Rq(A)|≤0.25μm.

[0019] Effects of the Invention

[0020] According to the present invention, it is possible to achieve both low transmission loss and high visibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic perspective view showing an example of an antenna according to an embodiment of the present invention.

[0022] Figure 2 This is a schematic plan view showing an example of an antenna according to an embodiment of the present invention.

[0023] Figure 3 This is a schematic cross-sectional view showing an example of an antenna according to an embodiment of the present invention.

[0024] Figure 4 This is a schematic diagram showing an example of a mesh pattern of silver thin wires constituting the antenna according to the embodiment of the present invention.

[0025] Figure 5 This is an enlarged view showing an example of a mesh pattern of silver thin wires constituting the antenna according to the embodiment of the present invention.

[0026] Figure 6 This is a schematic longitudinal cross-sectional view showing an example of a silver thin wire constituting the antenna according to the embodiment of the present invention.

[0027] Figure 7 This is a schematic cross-sectional view showing an example of a silver thin wire constituting the antenna according to the embodiment of the present invention.

[0028] Figure 8 This is a schematic cross-sectional view showing an example of the arrangement of silver thin wires constituting the antenna according to the embodiment of the present invention.

[0029] Fig. 9 It is a schematic diagram showing a first example of an antenna array including antennas according to an embodiment of the present invention.

[0030] Fig.10 It is a schematic diagram showing a second example of an antenna array including antennas according to an embodiment of the present invention.

[0031] Fig.11 It is a schematic diagram showing a third example of an antenna array including antennas according to an embodiment of the present invention.

[0032] Fig.12 It is a schematic diagram showing an example of arrangement of a plurality of antennas according to an embodiment of the present invention.

[0033] Fig.13 This is a schematic plan view showing another example of the antenna according to the embodiment of the present invention.

[0034] Fig.14 These are schematic plan views showing two other examples of antennas according to the embodiments of the present invention.

[0035] Fig.15 It is a schematic plan view showing another example of the antenna element of the antenna according to the embodiment of the present invention.

[0036] Fig.16 This is a schematic diagram showing an example of a rolling process for manufacturing the antenna according to the embodiment of the present invention.

[0037] Fig.17 is a schematic diagram showing an antenna array pattern.

[0038] Fig.18 is a schematic diagram showing a ground plane pattern.

[0039] Fig.19 is a schematic diagram showing a grid pattern.

[0040] Fig. 20 is a schematic cross section showing a structure for evaluating transmission loss.

[0041] Fig.21 It is a schematic plan view showing a structure for evaluating transmission loss. DETAILED DESCRIPTION

[0042] Hereinafter, the antenna of the present invention will be described in detail based on the preferred embodiments shown in the accompanying drawings.

[0043] In addition, the drawings described below are exemplary drawings for explaining the present invention, and the present invention is not limited to the drawings shown below.

[0044] In addition, the following "to" indicating a numerical range includes the numerical values ​​described on both sides. For example, ε is a numerical value α to a numerical value β, which means that the range of ε is a range including the numerical values ​​α and β, and when expressed in mathematical symbols, it is α≤ε≤β.

[0045] Unless otherwise specified, angles such as “angles expressed by specific numerical values”, “parallel”, “perpendicular” and “orthogonal” include error ranges generally allowed in the corresponding technical fields.

[0046] Furthermore, “entire surface” and the like include an error range generally allowed in the corresponding technical field.

[0047] In addition, light refers to active light or radiation. Unless otherwise specified, "exposure" in this specification includes not only exposure using a mercury lamp, extreme ultraviolet light represented by an excimer laser, X-rays, EUV light, etc., but also drawing using a particle beam such as an electron beam and an ion beam.

[0048] Furthermore, “(meth)acrylate” means both or either of acrylate and methacrylate, and “(meth)acrylic acid” means both or either of acrylic acid and methacrylic acid.

[0049] In addition, unless otherwise specified, transparency means transparency to visible light. Unless otherwise specified, transparency means that the light transmittance in the visible light wavelength region of 380 to 780 nm is 92% or more.

[0050] The light transmittance is a value measured according to "Plastics - Method for determining total light transmittance and total light reflectance" specified in JIS (Japanese Industrial Standards) K 7375:2008.

[0051] (antenna)

[0052] The antenna comprises a transparent film substrate, an antenna element disposed on one of the two surfaces of the transparent film substrate, and a grounding portion disposed on the other surface. The antenna element and the grounding portion are both composed of a mesh pattern formed of silver fine wires. In addition, the antenna comprises a power supply line disposed on one surface of the transparent film substrate, that is, on the same surface as the antenna element. The power supply line is also composed of a mesh pattern formed of silver fine wires.

[0053] The antenna will be described in detail below.

[0054] Figure 1 is a schematic perspective view showing an example of an antenna according to an embodiment of the present invention, Figure 2 is a schematic plan view showing an example of an antenna according to an embodiment of the present invention, Figure 3 1 is a schematic cross-sectional view showing an example of an antenna according to an embodiment of the present invention. Figure 1 and Figure 2 In the figure, the grid pattern is omitted.

[0055] Figure 1 The antenna 10 shown has a transparent film substrate 12, and an antenna element 14 and a power supply line 15 provided on a surface 12a of the transparent film substrate 12. The antenna 10 has a ground portion 16 provided on a back surface 12b of the transparent film substrate 12 facing the surface 12a of the transparent film substrate 12. The antenna element 14 and the power supply line 15 constitute an antenna portion 13. The antenna 10 is an antenna called a microstrip antenna, the antenna element 14 is also called a radiation element, and the power supply line 15 is also called a microstrip line.

[0056] Figure 1 and Figure 2 In the antenna 10 shown, for example, the outer shape of the antenna element 14 is a quadrilateral with an internal angle of 90 degrees. In the antenna element 14, the side 14a and the side 14b are orthogonal. The side 14b is a side extending in a direction parallel to the longitudinal direction of the feed line 15.

[0057] The length of the side 14 a is W, and the length of the side 14 b is L. The length W of the side 14 a and the length L of the side 14 b are appropriately set according to characteristics such as the frequency of transmission and reception of the antenna 10 .

[0058] The feed line 15 is inserted into the antenna element 14. The insertion amount of the feed line 15 into the antenna element 14 is denoted by R. The insertion amount R enables impedance matching.

[0059] like Figure 3 As shown in FIG. 1 , the grounding portion 16 is provided on the entire surface of the back surface 12b of the transparent film substrate 12. The grounding portion 16 functions as a ground plane. In addition, the grounding portion 16 also functions as a radio wave reflection layer, and the directivity of the antenna 10 is controlled by the grounding portion 16. The grounding portion 16 only needs to be larger than the antenna element 14, and does not necessarily have to be provided on the entire surface of the back surface 12b of the transparent film substrate 12.

[0060] Figure 1 The antenna 10 shown is a type in which power is supplied to the antenna element 14 via a power supply line 15 disposed on the same surface as the antenna element 14 .

[0061] Antenna 10 has a notch for inserting feed line 15 from the end of antenna element 14 toward the inner region, and the front end of the notch is electrically connected to feed line 15. Antenna 10 can match impedance by adjusting the position of the front end of feed line 15, that is, adjusting insertion amount R.

[0062] in addition, Figure 1 The operating frequency of the antenna 10 shown is determined by the length L of the side 14b. When the center frequency is fc, the center frequency fc is obtained by the following formula. In the following formula, c is the speed of light, ε r is the relative dielectric constant of the transparent film substrate, ε0 is the vacuum dielectric constant, and μ0 is the vacuum magnetic permeability. In addition, in the antenna pattern design, the resonance length may deviate slightly from the length L due to the influence of the pattern shape, substrate thickness, dielectric constant, etc.

[0063] [Formula 1]

[0064]

[0065] The input impedance can be changed by changing the length W of the side 14a of the antenna element 14 of the antenna 10. If the length W of the side 14a is increased, the input impedance can be reduced. Figure 1 In the structure of the antenna 10 shown, for example, as an antenna that supports the 28 GHz frequency band and has an impedance of 50Ω, the length W of the side 14a and the length L of the side 14b are both 3 mm, and the insertion amount R is 0.75 mm.

[0066] Figure 1 The antenna 10 shown is configured to have a power supply line 15 in the antenna element 14 , but is not limited thereto. The power supply line 15 may be not connected to the antenna element 14 , and the power supply line 15 may not be provided on the surface 12 a of the transparent film substrate 12 .

[0067] in, Figure 4 is a schematic diagram showing an example of a mesh pattern of silver thin wires constituting an antenna according to an embodiment of the present invention, Figure 5 This is an enlarged view showing an example of a mesh pattern of silver thin wires constituting the antenna according to the embodiment of the present invention.

[0068] Figure 1 In the antenna 10 shown in FIG. 1 , as described above, the antenna element 14, the power supply line 15, and the ground portion 16 are all formed of a mesh pattern formed of silver fine wires. Specifically, for example, Figure 4 and Figure 5 As shown, the mesh pattern has a plurality of rhombus-shaped openings 22 (lattices) formed by a plurality of thin lines 20 crossing at 90 degrees.

[0069] In the antenna 10, the line width Ws (refer to Figure 5 , Figure 6 ) is 1.0 μm or more and less than 5.0 μm, preferably 2.1 μm or more and 3.7 μm or less. The thickness t of the thin wire 20 is preferably 0.5 μm or more and less than 5.0 μm. The thickness h of the transparent film substrate 12 (reference Figure 1 , Figure 2 ) is greater than or equal to 30 μm and less than or equal to 300 μm.

[0070] <Grid pattern>

[0071] like Figure 4 and Figure 5 As shown in FIG. 1 , the mesh pattern formed by the thin lines 20 refers to a shape including a plurality of rhombus-shaped openings 22 (lattices) formed by the intersecting thin lines 20. The openings 22 are areas surrounded by the thin lines 20 and exist within the mesh pattern. Figure 4 and Figure 5In the figure, the opening 22 has a rhombus shape, but it can also be other shapes. The opening 22 is preferably a triangle such as an equilateral triangle, an isosceles triangle, a right triangle, a square, a rectangle, a parallelogram, a trapezoid, a quadrilateral such as a (regular) hexagon, a (regular) octagon, a geometric figure formed by a combination of a circle, an ellipse and a star. In addition, the shape of one side of the opening 22 can be set to a straight line, a curved shape, or an arc shape. When set to an arc shape, for example, the two facing sides can be set to an outwardly convex arc shape, and the other two facing sides can be set to an inwardly convex arc shape. In addition, the shape of each side can be set to a wavy line shape of a continuous outwardly convex arc and an inwardly convex arc. Of course, the shape of each side can also be set to a sine curve.

[0072] <Thin line>

[0073] As described above, the structure of the thin wire 20 is not particularly limited as long as it is made of silver.

[0074] The thin wire 20 is not limited to being composed of a single metal silver, but may also be a structure containing silver and a polymer, or a structure containing a plurality of silver particles dispersed in a polymer. In this case, for example, the thin wire 20 is formed by a manufacturing method using silver halide. When the thin wire 20 is composed of a single metal silver, for example, it is formed by a vapor deposition method or a sputtering method.

[0075] As the thin wire 20, for example, Figure 6 As shown, the polymer 24 and a plurality of silver particles 26 are included. In the thin wire 20, the plurality of silver particles 26 are dispersed in the polymer 24 in many cases.

[0076] The type of polymer 24 is not particularly limited, and a known polymer can be used. Among them, a specific polymer described below is preferred as the polymer 24. The specific polymer is a polymer other than gelatin, that is, a polymer different from gelatin, and will be described below.

[0077] The silver particles 26 included in the thin wire 20 are a part that ensures the conductivity of the thin wire 20. The silver particles 26 may be dispersed in the polymer or may be aggregated. By being composed of silver, the thin wire is less likely to be broken.

[0078] Silver particles 26 Figure 6 The particles in the figure are granular in shape, but the shape of the silver particles 26 is not limited to the granular shape, and for example, the shape may be a fused shape in which part or all of the silver particles are bonded.

[0079] The ratio of the plurality of silver particles contained in the thin wire is preferably 70% by volume or more, and the upper limit is 90% by volume. If the ratio of the silver particles is 70% by volume or more, sufficient conductivity can be obtained and high-frequency transmission can be improved. In addition, the ratio of the silver particles can be obtained as described later.

[0080] The shape and the like of the thin wire silver particles can be determined by observing the cross section of the thin wire with a scanning electron microscope.

[0081] As the measurement method based on the above scanning electron microscope, first, in order to give conductivity to the surface of the thin wire, carbon vapor deposition is performed on the surface of the thin wire, and the surface morphology is observed by a scanning electron microscope (S-5200 SEM manufactured by Hitachi High-Tech Corporation), thereby being able to observe the region where the silver particles exist inside the thin wire. In addition, the observation is carried out under the secondary electron mode and the acceleration voltage: 10 kV.

[0082] At this time, the cross section of the thin wire was observed using a scanning electron microscope, and an acceleration voltage was selected to form a contrast between the polymer and the metal particles. More specifically, as a method for observing the cross section of the thin wire, after the cross section of the thin wire was cut with a microtome, carbon was evaporated on the exposed cross section to give conductivity, and the cross section was observed using a scanning electron microscope (S-5200 SEM manufactured by Hitachi High-Tech Corporation). In addition, the observation was carried out under the conditions of reflected electron mode and acceleration voltage: 5 kV.

[0083] The ratio (volume %) of the silver particles can be determined by calculating the area of ​​the silver particle portion and the area of ​​the entire thin wire from an image of a vertical cross section of the thin wire observed using a scanning electron microscope.

[0084] [Aperture ratio]

[0085] The length Wd of one side of the opening 22 is not particularly limited, and is preferably 1500 μm or less, more preferably 1300 μm or less, further preferably 1000 μm or less, further preferably 400 μm or less, and preferably 5 μm or more, more preferably 30 μm or more, further preferably 80 μm or more. When the side length of the opening is within the above range, the transparency can be maintained well, and when the antenna 10 is installed in front of the display device, the display content can be visually recognized without any sense of disobedience. In addition, when the antenna 10 is installed on glass, etc., there is no sense of disobedience.

[0086] In terms of visible light transmittance, the opening ratio of the mesh pattern is preferably 75% or more, more preferably 80% or more, further preferably 85% or more, further preferably 90% or more, and most preferably 95% or more. The larger the opening ratio of the mesh pattern, the less likely the antenna is to be visually recognized.

[0087] The aperture ratio refers to the ratio of the area on the transparent film substrate 12 excluding the area where the thin wires 20 exist in the mesh pattern area. In other words, it refers to the ratio of the openings 22 of the mesh pattern in the surface 12 a of the transparent film substrate 12 .

[0088] The aperture ratio can be measured as follows. First, the total light transmittance of the transparent film substrate after the grid pattern is formed is measured in the antenna portion. Next, for the antenna, the total light transmittance of the transparent film substrate after the grid pattern is formed is measured in 5 areas. The 5 areas of the transparent film substrate can be the same or different in size as long as the acquisition positions on the transparent film substrate are different. Next, the aperture ratio is calculated using the following formula. The average value of the 5 calculated aperture ratios is taken as the aperture ratio.

[0089] Aperture ratio = ((total light transmittance of the transparent film substrate after the mesh pattern is formed) / (total light transmittance of the transparent film substrate before the mesh pattern is formed)) × 100 (%)

[0090] [Line width and thickness of thin lines]

[0091] In the antenna, the line width Ws (reference Figure 6 ) with a plurality of silver particles 26 (reference Figure 6 ) exists. Considering the balance between conductivity and visual recognition difficulty, the line width Ws of the fine line is 1.0 μm or more and less than 5.0 μm. Considering that the fine line is not easily visually recognized, the line width Ws is preferably 2.1 μm or more and 3.7 μm or less. The line width Ws of the fine line (reference Figure 6 ) is less than 1.0 μm, the thin line is difficult to be visually identified, but the conductivity becomes smaller and the transmission loss becomes larger. On the other hand, the line width Ws (reference Figure 6 ) is 5.0 μm or more, conductivity is ensured and transmission loss is sufficiently small, but thin lines are easily visually recognized.

[0092] In the antenna, the thickness of the thin wire t (reference Figure 6 ) with a plurality of silver particles 26 (reference Figure 6 The thickness t of the thin wire is not particularly limited, but is preferably 0.5 μm or more and less than 5.0 μm, more preferably 0.5 to 3.0 μm, and even more preferably 1.0 to 2.0 μm, in view of the electrical conductivity and flexibility of the thin wire.

[0093] As described above, after the cross section of the thin wire is cut with a microtome, carbon vapor deposition is performed on the exposed cross section, and the cross section is observed with a scanning electron microscope to measure the line width Ws of the thin wire 20. With regard to the line width Ws of the thin wire 20, any five points of one thin wire are selected, and the arithmetic mean value of the line width obtained from the images of each vertical cross section observed with a scanning electron microscope is taken as the line width Ws.

[0094] Also, the thickness t of the thin line is also calculated by taking the arithmetic mean of the thicknesses at five locations corresponding to one thin line as the thickness t, similarly to the line width Ws.

[0095] [Surface roughness]

[0096] In order to suppress the visual recognition of reflection, there is a method of setting the surface of the thin wire to a convex-concave shape to suppress the light reflectivity. In this method, since there is no need to form a blackening layer on the thin wire, the manufacturing method is simplified. However, in the high frequencies used in 5G communications, especially in millimeter waves, due to the skin effect, a smooth conductor with an optimal surface roughness is preferred. On the other hand, when there are thin wires on both sides of a transparent film substrate, if the reflectivity difference between the thin wires close to the observation direction and the thin wires far from the observation direction becomes larger, it sometimes causes the thin wires to be visually recognized. Therefore, the difference between the surface roughness of the thin wire on the side close to the observation direction and the surface roughness of the thin wire on the side far from the observation direction is specified.

[0097] When observing the transparent film substrate 12 from one side or the other side, the surface roughness of the fine line surface on one side or the other side of the observation side is set to Rq(A), and the surface roughness of the transparent film substrate side surface of the fine line on the other side or one side opposite to the observation side is set to Rq(B), preferably satisfying 0.05μm≤Rq(A)≤0.35μm, and satisfying |Rq(B)-Rq(A)|≤0.25μm.

[0098] The surface roughness Rq(A) and the surface roughness Rq(B) are both root mean square roughness measured in accordance with JIS B0601:2013.

[0099] Regarding the surface roughness Rq(A), the thin wire was cut into cross sections in the longitudinal direction of the thin wire using a microtome (reference Figure 7 ) After the length of the thin wire is about 20μm, carbon vapor deposition is performed on the cross section of the exposed thin wire to give it conductivity. A scanning electron microscope is used to obtain a cross-sectional image. The image processing software ImageJ is used to analyze the obtained cross-sectional image to determine the surface roughness. The measurement range is set to 20μm, and cross-sectional images of any five locations of the thin wire are obtained to determine the surface roughness of each surface. The arithmetic mean of the surface roughness at the five locations is taken as the surface roughness Rq(A). When observed from the surface 20a of the thin wire 20, the surface roughness Rq(A) is the surface roughness of the surface 20a of the thin wire 20, which is actually the surface roughness of the surface 20a of the thin wire 20. Figure 7 The roughness of the surface composed of the plurality of silver particles 26 is shown.

[0100] Regarding the above-mentioned surface roughness Rq(B), similarly to the above-mentioned surface roughness Rq(A), the thin wire is cut into a cross section with a length of about 20 μm in the longitudinal direction by a slicer, and then the exposed cross section of the thin wire is carbon-evaporated to impart conductivity, and a cross-sectional image is obtained by a scanning electron microscope. The surface roughness is calculated by performing image analysis on the obtained cross-sectional image using the image processing software ImageJ. The measurement range is set to 20 μm, and cross-sectional images of any five locations of the thin wire are obtained to calculate the surface roughness of each surface. The arithmetic mean of the surface roughness of the five locations is taken as the surface roughness Rq(B). When observed from the surface 20a of the thin wire 20, the surface roughness Rq(B) is the surface roughness of the surface 20d of the thin wire 20, which is actually the surface roughness of the thin wire 20. Figure 7 The roughness of the surface composed of the plurality of silver particles 26 is shown.

[0101] Specifically, if Figure 8 As shown, the antenna 10 has thin wires 20 constituting the antenna element 14 and the power supply line 15 disposed on the surface 12a of the transparent film substrate 12. The thin wires 20 constituting the grounding portion 16 are disposed on the back surface 12b of the transparent film substrate 12. For example, when the antenna 10 is viewed from the surface 12a side of the transparent film substrate 12, the surface roughness of the surface 20a of the thin wires 20 constituting the antenna element 14 and the power supply line 15 is determined by Figure 7 The surface roughness of the surface formed by the plurality of silver particles 26 shown is Rq(A). The surface roughness of the surface 20d of the thin wire 20 constituting the grounding portion 16 is Rq(B). Figure 7 The roughness of the surface composed of the plurality of silver particles 26 shown is the surface roughness Rq(B) of the thin line on the transparent film substrate side of the surface on the side opposite to the observation side.

[0102] As described above, when the surface roughness Rq(A) and the surface roughness Rq(B) satisfy 0.05 μm ≤ Rq(A) ≤ 0.35 μm and |Rq(B) - Rq(A)| ≤ 0.25 μm, reflection of the fine line is reduced and the fine line is not easily visually recognized.

[0103] In addition, the surface roughness Rq(A) and the surface roughness Rq(B) are adjusted by the calendering process.

[0104] (Antenna Array)

[0105] Figure 1 The antenna 10 shown is not limited to a single antenna, but can be configured as a structure in which a plurality of antennas are arranged.

[0106] Fig. 9 is a schematic diagram showing a first example of an antenna array having antennas according to an embodiment of the present invention, Fig.10is a schematic diagram showing a second example of an antenna array having antennas according to an embodiment of the present invention, Fig.11 It is a schematic diagram showing a third example of an antenna array including antennas according to an embodiment of the present invention. Fig.12 is a schematic diagram showing an example of the configuration of multiple antennas according to an embodiment of the present invention. Figures 9 to 12 In, with Figure 1 The same components of the antenna 10 are denoted by the same reference numerals, and their detailed descriptions are omitted. Figures 9 to 12 In the figure, the grid pattern is omitted.

[0107] Fig. 9 In the antenna array 30 shown, for example, four antennas 10 are arranged in a manner such that the direction of the power supply line 15 is consistent. The four antennas 10 are all the same size and are arranged at equal intervals in one direction. Fig. 9 The antenna array 30 shown is also referred to as a linear array antenna or a linear array antenna.

[0108] In the antenna array 30 , all antennas 10 or some of the antennas 10 are excited, and the amplitude of the excitation current or the amplitude of the excitation voltage and the phase of the excitation current or the phase of the excitation voltage are controlled, thereby changing the radiation directivity and the like.

[0109] Fig.10 In the antenna array 30a shown, for example, the direction of the power supply line 15 is changed by 90 degrees to configure two antennas 10a and two antennas 10b. The two antennas 10a are configured so that the sides 14b are aligned in the Vy direction. The two antennas 10b are configured so that the sides 14b are aligned in the Hx direction. In addition, the Vy direction is orthogonal to the Hx direction.

[0110] Antenna 10a transmits and receives vertically polarized light, for example. Antenna 10b transmits and receives horizontally polarized light, for example, in the H direction. In antenna array 30a, by configuring two antennas 10a and 10b with different polarization directions, stable transmission and reception can be performed in all directions. Fig.10 The structure of the antenna 10a, 10b shown is similar to Figure 1 The antennas 10 shown are identical.

[0111] Fig.11 In the antenna array 30b, antennas 10c and 10d of different sizes are arranged in a straight line. The length of the side 14a of the antenna 10c is W1, and the length of the side 14b is L1. The length of the side 14a of the antenna 10d is W2, and the length of the side 14b is L2. The length W1 of the side 14a of the antenna 10c is greater than the length W2 of the side 14a of the antenna 10d. The length L1 of the side 14b of the antenna 10c is greater than the length L2 of the side 14b of the antenna 10d.

[0112] As described above, the operating frequency of the antenna, that is, the center frequency fc, is determined by the length of the side 14b. According to the above formula, when the length of the side 14b of the antenna 10 is long, the center frequency fc becomes smaller. Fig.11 The antenna array 30b shown can transmit and receive multiple frequencies by arranging antennas with different lengths of sides 14b. The length W1 of the side 14a of the antenna 10c and the length W2 of the side 14a of the antenna 10d are determined according to input impedance.

[0113] in addition, Fig.11 The antennas 10c and 10d shown are similar to the antennas 10c and 10d except for the difference in side length. Figure 1 The antennas 10 shown have the same structure.

[0114] And, if Fig.12 In the antenna array 30c shown, the plurality of antennas 10 can also be configured as follows: the antenna unit 13 is provided on the surface 12a of the transparent film substrate 12, and the antenna unit 13 is provided on the back surface 12b. Thus, it is possible to transmit and receive on the surface 12a of the transparent film substrate 12, and it is also possible to transmit and receive on the back surface 12b of the transparent film substrate 12. Therefore, for example, by providing the transparent film substrate 12 on a window of a building or a wall separating rooms, communication between the outside and the inside of the building, or communication between rooms can be achieved.

[0115] In addition, the antenna arrays 30, 30a, 30b, and 30c are not limited to being arranged in a straight line, but may be arranged in a plane. In this case, for example, the antennas 10 are arranged in two orthogonal directions.

[0116] In the antenna arrays 30, 30a, 30b, and 30c, the antenna 10 also has the antenna portion 13 and the ground portion 16 formed in a mesh pattern of silver fine wires, so that a plurality of antennas 10 can be simultaneously formed on the transparent film substrate 12. Furthermore, the antenna arrays 30, 30a, 30b, and 30c can be continuously manufactured by utilizing a roll-to-roll process.

[0117] (Other Examples of Antennas)

[0118] Not limited to Figure 1 The structure of the antenna 10 is shown. Other examples of the antenna will be described below. Fig.13 is a schematic plan view showing another example of an antenna according to an embodiment of the present invention, Fig.14 These are schematic plan views showing two other examples of antennas according to the embodiments of the present invention. Fig.15 1 is a schematic plan view showing another example of an antenna element of an antenna according to an embodiment of the present invention. Figure 13 to Figure 15 In, with Figure 1 The same components of the antenna 10 are denoted by the same reference numerals, and their detailed descriptions are omitted. Fig.13 and Fig.15 In the figure, the grid pattern is omitted.

[0119] Fig.13 The antenna 10 shown is Figure 1 The antenna 10 shown in FIG. 1 is different in that the power supply line 15 is not inserted into the antenna element 14. The other structures are the same as those shown in FIG. Figure 1 The antennas 10 shown are identical. Fig.13 The insertion amount R of the antenna 10 shown (reference Figure 2 ) is zero.

[0120] And, if Fig.14 The antenna 10 shown may have a structure having a dummy pattern portion 17 around the antenna portion 13. The dummy pattern portion 17 is provided at a distance Gt from the antenna portion 13. No mesh pattern is formed in the distance Gt. Due to the distance Gt, the antenna portion 13 and the dummy pattern portion 17 are not electrically connected. Fig.14 In the illustrated antenna, lines indicating the outline of the antenna 10 and the outline of the dummy pattern portion 17 do not actually exist.

[0121] The width of the gap Gt is preferably 5 μm or more and 50 μm or less, and more preferably 7 μm or more and 20 μm or less. If the gap Gt is within the above range, the antenna portion 13 and the dummy pattern portion 17 will not be electrically connected, and the visual recognition of the dummy pattern portion 17 can also be suppressed. In addition, the length of the conductive portion inside the dummy pattern portion 17 is preferably less than 1 / 4 of the resonance wavelength of the antenna, and more preferably less than 1 / 10.

[0122] In addition, the dummy pattern portion 17 is provided at a gap Gt from the antenna portion 13, but the present invention is not limited thereto. The antenna portion 13 and the dummy pattern portion 17 may be formed without providing a gap Gt where the mesh pattern is not formed. In this case, a part of the thin wire 20 constituting the mesh pattern is cut off to provide a disconnected portion so as to be non-conductive, thereby making the antenna portion 13 and the dummy pattern portion 17 in a non-electrically connected state.

[0123] and, Figure 1 The antenna element 14 of the antenna 10 shown, Fig.13 The antenna element 14 of the antenna 10 is shown as Fig.14 The antenna elements 14 of the antenna 10 shown are all quadrilaterals of the same shape, but are not limited thereto. Fig.15 The antenna element 32 shown may have a structure having notches 33 formed by cutting opposite corners on a diagonal line. The antenna element 32 generates circularly polarized light. Fig.15 The antenna element 32 shown is used to transmit and receive left-hand circularly polarized light. Fig.15 The antenna element 32 shown has notches on different diagonal lines, so that it can transmit and receive right-handed circularly polarized light.

[0124] In addition to the above-mentioned configuration, the antenna element may be, for example, circular or elliptical, or may be a polygon such as a triangle.

[0125] The power supply line is not particularly limited as long as impedance matching can be achieved, and may be in a ring shape or an L shape.

[0126] Furthermore, the antenna is not limited to Figure 1 A microstrip antenna, such as the antenna 10 shown, may be a slot antenna.

[0127] And, in such Figures 9 to 12 In the antenna arrays 30, 30a, 30b, and 30c shown in the drawings, a dummy pattern portion 17 ( Fig.14 ). Regarding the dummy pattern portion 17, as Fig.14 As shown, the gap Gt may be provided. Also, the dummy pattern portion 17 may be formed without providing the gap Gt. At this time, as described above, a part of the thin wires 20 constituting the mesh pattern is cut off to provide a disconnected portion to become non-conductive, thereby being in a non-electrically connected state.

[0128] In such Figures 9 to 12 In the antenna arrays 30, 30a, 30b, and 30c shown in the figure, the antenna element 14 of the antenna 10 can also be set to Fig.15 Antenna element 32 is shown.

[0129] (Antenna installation location)

[0130] The location of the antenna is not particularly limited. Examples of the location of the transparent antenna include windows of buildings (Japanese Patent Publication No. 2006-287729), glass of automobiles (US7656357), display units of mobile terminals (US20140106684, US7847753), display panels (WO2019 / 223713), and frame units (US20180342789).

[0131] Furthermore, the antenna is provided at the above-mentioned setting position as a glass antenna sandwiched by glass together with the film substrate (WO2019 / 107514). Furthermore, as a flexible film antenna, the antenna can also be provided as a curved surface to improve the design or the directivity of the antenna.

[0132] However, when the antenna is set in a window, a display portion of a terminal, or a frame portion of a terminal, compared with the case where it is set inside the device, further environmental resistance is required, for example, UV (Ultraviolet) resistance and low hygroscopicity are sometimes required to be higher. In this case, it is preferred to introduce a method for strengthening environmental resistance such as that shown in Patent Publication No. 6355824 (UV-resistant OCA (Optical Clear Adhesive)) or Patent Publication No. 5849059 (low hygroscopicity).

[0133] <Antenna Manufacturing Method>

[0134] Next, a method for manufacturing the antenna will be described.

[0135] The method for producing the antenna is not particularly limited as long as it can produce an antenna having the above structure, but a method for producing a conductive substrate having steps A to E described below in order is preferred from the viewpoint of excellent productivity. Each step will be described in detail below.

[0136] <Process A>

[0137] Step A is a step of forming a silver halide-containing photosensitive layer (hereinafter also referred to as a "photosensitive layer") containing silver halide, gelatin, and a polymer different from gelatin (hereinafter also referred to as a "specific polymer") on a transparent film substrate. Through this step, a transparent film substrate with a photosensitive layer subjected to an exposure treatment described later is manufactured.

[0138] First, the materials and components used in step A are described in detail, and then the steps of step A are described in detail.

[0139] (Transparent film substrate)

[0140] As described above, the transparent film substrate is formed with the antenna portion and the ground portion made of silver thin wires. The type of the transparent film substrate is not particularly limited as long as it can support the photosensitive layer, and the antenna portion and the ground portion made of silver thin wires.

[0141] The transparent film substrate is transparent, and for example, the total light transmittance is preferably 85 to 100%. The total light transmittance is measured according to "Plastics - Method for determining total light transmittance and total light reflectance" specified in JIS K7375:2008.

[0142] Furthermore, the transparent film substrate is preferably flexible. A flexible substrate refers to a substrate that can be bent, specifically, a substrate that does not break even when bent with a curvature radius of 2 mm. The transparent film substrate has processability that allows it to be formed into a three-dimensional shape. In addition, by using a flexible transparent film substrate, the antenna has flexibility.

[0143] As the material constituting the transparent film substrate, preferred are resins having a melting point of about 290°C or less, such as polyethylene terephthalate (PET) (258°C), polycycloolefin (134°C), polycarbonate (250°C), acrylic film (128°C), polyethylene naphthalate (269°C), polyethylene (135°C), polypropylene (163°C), polystyrene (230°C), polyvinyl chloride (180°C), polyvinylidene chloride (212°C), and triacetyl cellulose (290°C), and PET, polycycloolefin and polycarbonate are more preferred. Among them, PET is most preferred from the viewpoint of excellent adhesion to the silver fine wire. In addition, the numerical value in () is the melting point or glass transition temperature.

[0144] As mentioned above, the thickness h of the transparent film substrate (reference Figure 1 , Figure 2 ) is 30 μm or more and 300 μm or less. When the thickness h of the transparent film substrate is less than 30 μm, the antenna portion and the ground portion cannot be sufficiently held. On the other hand, when the thickness h of the transparent film substrate exceeds 300 μm, it is difficult to bend.

[0145] Since transparent film substrates are lighter than glass substrates, they are preferred. However, from the perspective of impedance matching, it is necessary to narrow the antenna element and the power supply line. In the antenna, as described above, the line width of the silver thin wire is adjusted to achieve a balance between low transmission loss and visual recognition.

[0146] A primer layer may be disposed on the surface of the transparent film substrate.

[0147] The primer layer preferably contains a specific polymer described below. When the primer layer is used, the adhesion to the transparent film substrate of the silver thin wire described below is further improved.

[0148] The formation method of the primer layer is not particularly limited, for example, a method in which a primer layer-forming composition comprising a specific polymer is applied to a transparent film substrate and heat-treated as required can be cited. The primer layer-forming composition can contain a solvent as required. The type of solvent is not particularly limited, and the solvent used in the photosensitive layer-forming composition described later can be exemplified. In addition, as the primer layer-forming composition comprising a specific polymer, a latex containing particles of the specific polymer can be used.

[0149] The thickness of the primer layer is not particularly limited, but is preferably 0.02 to 0.3 μm, more preferably 0.03 to 0.2 μm, from the viewpoint of better adhesion of the thin wire to the transparent film substrate.

[0150] (Silver Halide)

[0151] The halogen atom contained in the silver halide can be any one of a chlorine atom, a bromine atom, an iodine atom and a fluorine atom, or these can be combined. For example, preferably, a silver halide with silver chloride, silver bromide or silver iodide as the main component, more preferably a silver halide with silver chloride or silver bromide as the main component. In addition, silver chlorobromide, silver iodochlorobromide or silver iodobromide is also preferably used.

[0152] For example, "silver halide with silver chloride as the main component" refers to a silver halide in which the molar fraction of chloride ions in all halide ions in the silver halide composition is 50% or more. The silver halide with silver chloride as the main component may contain bromide ions and / or iodide ions in addition to chloride ions.

[0153] Usually, silver halide is in the form of solid particles, and the average particle size of the silver halide is preferably 10 to 1000 nm in terms of equivalent spherical diameter, more preferably 10 to 200 nm, and further preferably 50 to 150 nm in terms of small change in resistance value of the silver thin wire in a hot and humid environment.

[0154] In addition, the equivalent spherical diameter refers to the diameter of a spherical particle having the same volume.

[0155] The "equivalent spherical diameter" used as the average particle size of the above-mentioned silver halide is an average value, and is a value obtained by measuring the equivalent spherical diameters of 100 silver halides and arithmetically averaging them.

[0156] The shape of the silver halide particles is not particularly limited, and examples thereof include spherical, cubic, flat (hexagonal, triangular, quadrilateral, etc.) flat, octahedral, and tetradecahedral shapes.

[0157] (gelatin)

[0158] The type of gelatin is not particularly limited, and examples thereof include lime-treated gelatin and acid-treated gelatin. In addition, gelatin hydrolysates, gelatin enzymatic decomposition products, and gelatin modified with amino groups and / or carboxyl groups (phthalated gelatin and acetylated gelatin) can be used.

[0159] (Polymer different from gelatin)

[0160] The photosensitive layer contains a polymer different from gelatin. When the photosensitive layer contains the specific polymer, the strength of the silver thin wire formed by the photosensitive layer is further improved.

[0161] The type of the specific polymer is not particularly limited as long as it is different from gelatin, but is preferably a polymer that is not decomposed by a proteolytic enzyme or oxidizing agent that decomposes gelatin as described below.

[0162] As specific polymers, hydrophobic polymers (water-insoluble polymers) can be cited, for example, (meth)acrylic resins, styrene resins, vinyl resins, polyolefin resins, polyester resins, polyurethane resins, polyamide resins, polycarbonate resins, polydiene resins, epoxy resins, silicone resins, at least one resin selected from the group consisting of cellulose polymers and chitosan polymers, or a copolymer composed of monomers constituting these resins, etc.

[0163] Furthermore, the specific polymer preferably has a reactive group that reacts with a cross-linking agent described below.

[0164] The specific polymer is preferably in a particle form. That is, the photosensitive layer preferably contains particles of the specific polymer.

[0165] As the specific polymer, a polymer (copolymer) represented by the following general formula (1) is preferred.

[0166] General formula (1): -(A) x -(B) y -(C) z -(D) w -

[0167] In the general formula (1), A, B, C, and D each represent a repeating unit represented by the following general formulae (A) to (D).

[0168] [Chemical formula 1]

[0169]

[0170] R 1 represents a methyl group or a halogen atom, preferably a methyl group, a chlorine atom or a bromine atom. p represents an integer of 0 to 2, preferably 0 or 1, and more preferably 0.

[0171] R 2 It represents a methyl group or an ethyl group, preferably a methyl group.

[0172] R 3 represents a hydrogen atom or a methyl group, preferably a hydrogen atom. L represents a divalent linking group, preferably a group represented by the following general formula (2).

[0173] General formula (2): -(CO-X 1 )rX 2 -

[0174] In the general formula (2), X 1 Represents oxygen atom or NR 30 -. Among them, R 30 represents a hydrogen atom, an alkyl group, an aryl group or an acyl group, and each of them may have a substituent (for example, a halogen atom, a nitro group, a hydroxyl group, etc.). 30, preferably a hydrogen atom, an alkyl group having 1 to 10 carbon atoms (for example, methyl, ethyl, n-butyl, and n-octyl), or an acyl group (for example, acetyl and benzoyl). 1 , preferably an oxygen atom or NH-.

[0175] X 2 represents an alkylene group, an arylene group, an alkylenearylene group, an arylenealkylene group or an alkylenearylenealkylene group, and -O-, -S-, -CO-, -COO-, -NH-, -SO2-, -N(R 31 )-or-N(R 31 )SO2- etc. 31 represents a linear or branched alkyl group having 1 to 6 carbon atoms. 2 , preferably dimethylene, trimethylene, tetramethylene, o-phenylene, m-phenylene, p-phenylene, -CH2CH2OCOCH2CH2- or -CH2CH2OCO(C6H4)-, etc.

[0176] r represents 0 or 1.

[0177] q represents 0 or 1, preferably 0.

[0178] R 4 It represents an alkyl group, an alkenyl group or an alkynyl group, and is preferably an alkyl group having 5 to 50 carbon atoms, more preferably an alkyl group having 5 to 30 carbon atoms, and still more preferably an alkyl group having 5 to 20 carbon atoms.

[0179] R 5 Represents a hydrogen atom, a methyl group, an ethyl group, a halogen atom, or -CH2COOR 6 , preferably a hydrogen atom, a methyl group, a halogen atom or -CH2COOR 6 , more preferably a hydrogen atom, a methyl group or -CH2COOR 6 , and more preferably a hydrogen atom.

[0180] R 6 represents a hydrogen atom or an alkyl group having 1 to 80 carbon atoms, and may be combined with R 4 Same or different, R 6 The number of carbon atoms in the moiety is preferably 1-70, more preferably 1-60.

[0181] In the general formula (1), x, y, z and w represent the molar ratio of each repeating unit.

[0182] x is 3 to 60 mol %, preferably 3 to 50 mol %, more preferably 3 to 40 mol %.

[0183] y is 30 to 96 mol %, preferably 35 to 95 mol %, more preferably 40 to 90 mol %.

[0184] z is 0.5 to 25 mol %, preferably 0.5 to 20 mol %, more preferably 1 to 20 mol %.

[0185] w is 0.5 to 40 mol %, preferably 0.5 to 30 mol %.

[0186] In the general formula (1), it is preferred that x is 3 to 40 mol %, y is 40 to 90 mol %, z is 0.5 to 20 mol % and w is 0.5 to 10 mol %.

[0187] As the polymer represented by the general formula (1), a polymer represented by the following general formula (2) is preferred.

[0188] [Chemical formula 2]

[0189]

[0190] In the general formula (2), x, y, z and w are as defined above.

[0191] The polymer represented by the general formula (1) may contain other repeating units in addition to the repeating units represented by the above general formulae (A) to (D).

[0192] As monomers for other repeating units, for example, acrylates, methacrylates, vinyl esters, olefins, crotonates, itaconic acid diesters, maleic acid diesters, fumaric acid diesters, acrylamides, unsaturated carboxylic acids, allyl compounds, vinyl ethers, vinyl ketones, vinyl heterocyclic compounds, glycidyl esters and unsaturated nitriles can be cited. As these monomers, they are also described in paragraphs 0010 to 0022 of Patent Gazette No. 3754745. From the viewpoint of hydrophobicity, acrylates or methacrylates are preferred, and hydroxyalkyl methacrylate or hydroxyalkyl acrylate is more preferred.

[0193] The polymer represented by the general formula (1) preferably contains a repeating unit represented by the general formula (E).

[0194] [Chemical formula 3]

[0195]

[0196] In the above formula, L E The group represents an alkylene group, and is preferably an alkylene group having 1 to 10 carbon atoms, more preferably an alkylene group having 2 to 6 carbon atoms, and still more preferably an alkylene group having 2 to 4 carbon atoms.

[0197] As the polymer represented by the general formula (1), a polymer represented by the following general formula (3) is particularly preferred.

[0198] [Chemical formula 4]

[0199] General formula (3)

[0200]

[0201] In the above formula, a1, b1, c1, d1 and e1 represent the molar ratio of each repeating unit, a1 represents 3 to 60 (mol%), b1 represents 30 to 95 (mol%), c1 represents 0.5 to 25 (mol%), d1 represents 0.5 to 40 (mol%), and e1 represents 1 to 10 (mol%).

[0202] The preferred range of a1 is the same as the preferred range of x, the preferred range of b1 is the same as the preferred range of y, the preferred range of c1 is the same as the preferred range of z, and the preferred range of d1 is the same as the preferred range of w.

[0203] e1 is 1 to 10 mol %, preferably 2 to 9 mol %, more preferably 2 to 8 mol %.

[0204] The specific polymer can be synthesized by referring to, for example, Japanese Patent No. 3305459 and Japanese Patent No. 3754745.

[0205] The weight average molecular weight of the specific polymer is not particularly limited, but is preferably 1,000 to 1,000,000, more preferably 2,000 to 750,000, and even more preferably 3,000 to 500,000.

[0206] The photosensitive layer may contain other materials than the above materials as necessary.

[0207] For example, metal compounds belonging to Group 8 and Group 9 such as rhodium compounds and iridium compounds for stabilizing and increasing the sensitivity of silver halide can be cited. Alternatively, antistatic agents, nucleation promoters, spectral sensitizing dyes, surfactants, antifogging agents, film hardeners, black spot inhibitors, redox compounds, monomethylamine compounds, and dihydroxybenzenes described in paragraphs 0220 to 0241 of Japanese Patent Application Laid-Open No. 2009-004348 can also be cited. Furthermore, the photosensitive layer can contain a physical development nucleus.

[0208] Furthermore, the photosensitive layer may contain a crosslinking agent for crosslinking the specific polymers. By containing the crosslinking agent, the specific polymers are crosslinked, and even when the gelatin is decomposed and removed, the connection between the metallic silver in the thin wires is maintained.

[0209] (Steps of Process A)

[0210] The method for forming the photosensitive layer containing the above-mentioned components in step A is not particularly limited. From the perspective of productivity, a method in which a photosensitive layer is formed on a transparent film substrate by contacting a photosensitive layer-forming composition containing silver halide, gelatin and a specific polymer with a transparent film substrate is preferred.

[0211] Hereinafter, the form of the photosensitive layer-forming composition used in this method will be described in detail, and then the steps of the process will be described in detail.

[0212] (Materials Contained in the Photosensitive Layer-Forming Composition)

[0213] The photosensitive layer forming composition contains the above-mentioned silver halide, gelatin and a specific polymer. In addition, the specific polymer can be contained in the photosensitive layer forming composition in the form of particles as needed.

[0214] The photosensitive layer-forming composition may contain a solvent as necessary.

[0215] Examples of the solvent include water, organic solvents (for example, alcohols, ketones, amides, sulfoxides, esters, and ethers), ionic liquids, and mixed solvents thereof.

[0216] The method of bringing the photosensitive layer-forming composition into contact with the transparent film substrate is not particularly limited, and examples thereof include a method of coating the photosensitive layer-forming composition on the transparent film substrate and a method of immersing the transparent film substrate in the photosensitive layer-forming composition.

[0217] Furthermore, after the above treatment, a drying treatment may be performed as necessary.

[0218] (Photosensitive layer containing silver halide)

[0219] The photosensitive layer formed through the above steps contains silver halide, gelatin and a specific polymer.

[0220] The content of the silver halide in the photosensitive layer is not particularly limited, but is preferably 3.0 to 20.0 g / m2 in terms of silver conversion from the viewpoint of better conductivity of the conductive film. 2 , more preferably 5.0 to 15.0 g / m 2 .

[0221] Silver conversion refers to the mass of silver produced by the reduction of all silver halides.

[0222] The content of the specific polymer in the photosensitive layer is not particularly limited, but is preferably 0.04 to 2.0 g / m 2 , more preferably 0.08 to 0.40 g / m 2 , more preferably 0.10 to 0.40 g / m 2 .

[0223] <Process B>

[0224] Step B is a step of exposing the photosensitive layer and then developing it to form a thin line-shaped silver-containing layer containing metallic silver, gelatin, and polymer.

[0225] By subjecting the photosensitive layer to exposure processing, a latent image is formed in the exposed area.

[0226] The exposure may be performed in a pattern. For example, in order to obtain a mesh pattern composed of silver fine wires described later, exposure is performed through a mask having a mesh opening pattern, and exposure is performed in a mesh pattern by scanning with a laser.

[0227] The type of light used for exposure is not particularly limited as long as it is light that can form a latent image on the silver halide, and examples thereof include visible light, ultraviolet light, and X-rays.

[0228] By subjecting the exposed photosensitive layer to a development process, metallic silver is deposited in the exposed region (region where a latent image is formed).

[0229] The method of the development treatment is not particularly limited, and examples thereof include known methods used for silver salt photographic films, printing papers, films for printing plate making, and emulsion masks for photomasks.

[0230] Generally, a developer is used in the development process. The type of the developer is not particularly limited, and examples thereof include PQ (phenidone hydroquinone) developer, MQ (metol hydroquinone) developer, and MAA (methol ascorbic acid) developer.

[0231] This step may further include a fixing treatment for the purpose of removing the silver halide in the unexposed portion and stabilizing the image.

[0232] The fixing treatment is performed simultaneously with the development and / or after the development. The method of the fixing treatment is not particularly limited, and examples thereof include methods used for silver salt photographic films, printing papers, films for printing plate making, and emulsion masks for photomasks.

[0233] Usually, a fixing solution is used in the fixing process. The type of the fixing solution is not particularly limited, and examples thereof include the fixing solution described in "Chemistry of Photography" (written by Sasai, Photo Industry Publishing Co., Ltd.), p. 321.

[0234] By performing the above-mentioned treatment, a thin line-shaped silver-containing layer containing metallic silver, gelatin and a specific polymer is formed.

[0235] As a method for adjusting the width of the silver-containing layer, for example, there is a method of adjusting the opening width of a mask used for exposure. For example, by setting the opening width of the mask to be greater than 1.0 μm and less than 5.0 μm, the exposure region can be adjusted.

[0236] Furthermore, when a mask is used during exposure, the width of the formed silver-containing layer can be adjusted by adjusting the exposure amount. For example, when the opening width of the mask is narrower than the width of the target silver-containing layer, the width of the area where the latent image is formed can be adjusted by increasing the exposure amount more than usual. That is, the line width of the silver fine line can be adjusted by the exposure amount.

[0237] Furthermore, when using laser, the exposure area can be adjusted by adjusting the focusing range and / or scanning range of the laser.

[0238] The width of the silver-containing layer is preferably 1.0 μm or more and less than 5.0 μm, and is more preferably 3.7 μm or less from the viewpoint that the formed silver thin wires are not easily visually recognized.

[0239] The silver-containing layer obtained by the above steps is in the form of thin lines, and the width of the silver-containing layer refers to the length (width) of the silver-containing layer in a direction perpendicular to the direction in which the thin line-shaped silver-containing layer extends.

[0240] <Process C>

[0241] Step C is a step of subjecting the silver-containing layer obtained in step B to a heat treatment. By carrying out this step, fusion between specific polymers in the silver-containing layer is promoted, and the strength of the silver-containing layer is improved.

[0242] The method of heat treatment is not particularly limited, and examples thereof include a method of bringing the silver-containing layer into contact with superheated steam and a method of heating the silver-containing layer using a temperature control device (eg, a heater). Preferably, the method of bringing the silver-containing layer into contact with superheated steam is used.

[0243] The superheated steam may be superheated steam or a mixture of superheated steam and other gases.

[0244] The contact time between the superheated steam and the silver-containing layer is not particularly limited, but is preferably 10 to 70 seconds.

[0245] The supply rate of superheated steam is preferably 500 to 600 g / m 3 The temperature of the superheated steam is preferably 100 to 160° C. (preferably 100 to 120° C.) at 1 atmosphere.

[0246] As heating conditions in the method of heating the silver-containing layer with a temperature control device, heating at 100 to 200° C. (preferably 100 to 150° C.) for 1 to 240 minutes (preferably 60 to 150 minutes) is preferred.

[0247] <Process D>

[0248] Step D is a step of removing gelatin from the silver-containing layer obtained in step C. By carrying out this step, gelatin is removed from the silver-containing layer, and spaces are formed in the silver-containing layer.

[0249] The method for removing gelatin is not particularly limited, and examples thereof include a method using a proteolytic enzyme (hereinafter also referred to as "method 1") and a method of decomposing and removing gelatin using an oxidizing agent (hereinafter also referred to as "method 2").

[0250] Examples of the proteolytic enzyme used in method 1 include known plant enzymes or animal enzymes that can hydrolyze proteins such as gelatin.

[0251] Examples of the proteolytic enzyme include pepsin, rennet, trypsin, chymotrypsin, cathepsin, papain, ficin, thrombin, renin, collagenase, bromelain, and bacterial proteases, and preferably trypsin, papain, ficin, or bacterial proteases.

[0252] The step in method 1 may be any method as long as it is a method of contacting the silver-containing layer with the above-mentioned proteolytic enzyme, and for example, a method of contacting the silver-containing layer with a treatment solution containing a proteolytic enzyme (hereinafter also referred to as "enzyme solution") can be mentioned. As the contact method, a method of immersing the silver-containing layer in the enzyme solution and a method of coating the silver-containing layer with the enzyme solution can be mentioned.

[0253] The content of the proteolytic enzyme in the enzyme solution is not particularly limited, but is preferably 0.05 to 20% by mass, more preferably 0.5 to 10% by mass, based on the total amount of the enzyme solution, from the viewpoint of easily controlling the degree of decomposition and removal of gelatin.

[0254] The enzyme solution generally contains water in addition to the above-mentioned proteolytic enzyme.

[0255] The enzyme solution may contain other additives (eg, pH buffers, antimicrobial compounds, wetting agents, and anti-degradants) as needed.

[0256] The pH of the enzyme solution is selected within a range that maximizes the effect of the enzyme, and is usually preferably 5 to 9.

[0257] The temperature of the enzyme solution is preferably a temperature at which the enzyme action increases, specifically, preferably 25 to 45°C.

[0258] Furthermore, the obtained silver-containing layer may be subjected to a cleaning treatment with warm water after the treatment with the enzyme solution, if necessary.

[0259] The cleaning method is not particularly limited, but is preferably a method of bringing the silver-containing layer into contact with warm water. Examples of the method include a method of immersing the silver-containing layer in warm water and a method of applying warm water to the silver-containing layer.

[0260] The temperature of the warm water is optimally selected depending on the type of proteolytic enzyme used, and is preferably 20 to 80° C., more preferably 40 to 60° C., from the viewpoint of productivity.

[0261] The contact time (cleaning time) of the warm water and the silver-containing layer is not particularly limited, but is preferably 1 to 600 seconds, more preferably 30 to 360 seconds, from the viewpoint of productivity.

[0262] The oxidant used in method 2 may be any oxidant capable of decomposing gelatin, and preferably has a standard electrode potential of +1.5 V or higher. The standard electrode potential refers to the standard electrode potential of the oxidant relative to a standard hydrogen electrode in an aqueous solution (25° C., E0).

[0263] Examples of the oxidizing agent include persulfuric acid, percarbonic acid, perphosphoric acid, hypoperchloric acid, peracetic acid, meta-chloroperbenzoic acid, hydrogen peroxide solution, perchloric acid, periodic acid, potassium permanganate, ammonium persulfate, ozone, hypochlorous acid or its salts, and the like. From the viewpoint of productivity and economic efficiency, hydrogen peroxide solution (standard electrode potential: 1.76 V), hypochlorous acid or its salts are preferred, and sodium hypochlorite is more preferred.

[0264] As the step in method 2, any method may be used as long as it is a method of contacting the silver-containing layer with the above-mentioned oxidant, for example, a method of contacting the silver-containing layer with a treatment solution containing an oxidant (hereinafter also referred to as "oxidant solution") can be mentioned. As the contact method, a method of immersing the silver-containing layer in the oxidant liquid and a method of coating the silver-containing layer with the oxidant liquid can be mentioned.

[0265] The type of solvent contained in the oxidizing agent liquid is not particularly limited, and examples thereof include water and organic solvents.

[0266] <Process E>

[0267] Step E is a step of obtaining silver thin wires by plating the silver-containing layer obtained in step D. By performing this step, silver thin wires are formed in which the space formed by removing the gelatin is filled with metal (plated metal).

[0268] The type of plating treatment is not particularly limited, and electroless plating (chemical reduction plating or displacement plating) and electrolytic plating can be cited, and electroless plating is preferred. As electroless plating, a known electroless plating technique is used. As plating treatment, silver plating treatment is more preferred.

[0269] The components contained in the plating solution used in the plating treatment are not particularly limited, and generally contain, in addition to a solvent (e.g., water), 1. metal ions for plating, 2. a reducing agent, 3. an additive (stabilizer) for improving the stability of the metal ions, and 4. a pH adjuster. In addition to these, the plating bath may also contain known additives such as a stabilizer for the plating bath.

[0270] The type of metal ions for plating contained in the plating solution is appropriately selected according to the type of metal to be deposited, and silver ions can be used.

[0271] The procedure of the plating treatment is not particularly limited as long as the silver-containing layer is brought into contact with the plating solution. For example, there can be mentioned a method of immersing the silver-containing layer in the plating solution.

[0272] The contact time between the silver-containing layer and the plating solution is not particularly limited, but is preferably 1 to 30 minutes from the perspective of better conductivity of the silver thin wire and productivity. The volume % of the silver particles can be changed by adjusting the plating treatment time, and the proportion of the silver particles can be increased by extending the plating treatment time, thereby increasing the volume % of the silver particles.

[0273] <Process F>

[0274] The method for manufacturing an antenna of the present invention may include, after step E, step F of further subjecting the silver thin wire obtained in step E to a smoothing treatment.

[0275] By carrying out this step, a silver thin wire with better conductivity can be obtained.

[0276] The method of smoothing treatment is not particularly limited, and for example, it is preferable to pass the transparent film substrate having the silver fine wires through a calendering treatment step between at least a pair of rollers under pressure. Hereinafter, the smoothing treatment using calendering rollers is referred to as calendering treatment.

[0277] in, Fig.16 This is a schematic diagram showing an example of a rolling process for manufacturing the antenna according to the embodiment of the present invention.

[0278] like Fig.16 As shown, the calendering process uses a first calendering roll 40a and a second calendering roll 40b that are arranged facing each other.

[0279] Furthermore, when the calendaring process is performed, a co-carrying mat 42 that is carried together with the transparent film substrate 12 is used.

[0280] The thin wires 34 are formed on the front surface 12a side of the transparent film substrate 12, and the thin wires 35 are formed on the back surface 12b side. The thin wires 34 are the thin wires 20 constituting the antenna portion 13. The thin wires 35 are the thin wires 20 constituting the ground portion 16.

[0281] Examples of the first calender roll 40 a and the second calender roll 40 b used in the calendering process include plastic rolls and metal rolls. From the viewpoint of wrinkle prevention, plastic rolls are preferred.

[0282] The pressure between the rolls is not particularly limited, but is preferably 2 MPa or more, more preferably 4 MPa or more, and preferably 120 MPa or less. The pressure between the rolls can be measured using a pressure measuring film "Prescale" (for high pressure) manufactured by Fujifilm Corporation.

[0283] The temperature of the smoothing treatment is not particularly limited, but is preferably 10 to 100°C, more preferably 10 to 50°C.

[0284] As described above, the co-carrying mat 42 is used to control the surface shape of the thin wires 34 and 35 by performing a calendering process. The co-carrying mat 42 can use a film material used in a calendering process described in Japanese Patent Application Laid-Open No. 2016-118819, for example.

[0285] During the calendering process, while the fine wires 35 on the back side 12b of the transparent film substrate 12 are overlapped with the common carrier pad 42, the surface shape of the fine wires 35 is controlled by applying pressure through the first calendering roller 40a and the second calendering roller 40b, thereby obtaining the fine wires 20 having the above-mentioned surface roughness Rq(A) and Rq(B).

[0286] The surface roughness Rq(A) and Rq(B) can be adjusted by the material of the first calendering roller 40a and the second calendering roller 40b, the surface roughness of the first calendering roller 40a and the second calendering roller 40b, the material of the co-carrying pad, the pressure between the rollers during the calendering process, the temperature during the calendering process, etc.

[0287] The calendering process controls the surface shape of the thin wires 20 on the transparent film substrate, and can produce a conductive material in which the thin wires 20 are difficult to see, the resistance is low, and the visibility, conductivity, and disconnection rate are improved.

[0288] <Process G>

[0289] The method for manufacturing an antenna of the present invention may include a step G of subjecting the silver thin wire obtained in step F to a heat treatment after step F. By performing this step, a silver thin wire having a higher electrical conductivity can be obtained.

[0290] The method for heat-treating the silver thin wire is not particularly limited, and the method described in step C can be used.

[0291] <Process H>

[0292] The method for manufacturing an antenna of the present invention may include a step H of forming a layer containing no silver halide and gelatin and a specific polymer on a transparent film substrate before step A. By carrying out this step, a layer containing no silver halide is formed between the transparent film substrate and the photosensitive layer containing silver halide. The layer containing no silver halide functions as a so-called antihalation layer and helps to improve the adhesion between the thin wire and the transparent film substrate.

[0293] The layer not containing silver halide contains the above-mentioned gelatin and a specific polymer. On the other hand, the layer not containing silver halide does not contain silver halide.

[0294] The ratio of the mass of the specific polymer to the mass of gelatin (mass of the specific polymer / mass of gelatin) in the layer not containing silver halide is not particularly limited, but is preferably 0.1 to 5.0, and more preferably 1.0 to 3.0.

[0295] The content of the specific polymer in the layer not containing silver halide is not particularly limited, but 0.03 g / m 2 The above cases are more common. From the perspective of better adhesion of the silver thin wire, 1.0 g / m 2 There is no particular upper limit, 1.63g / m 2 The following situations are more common.

[0296] The method for forming the layer not containing silver halide is not particularly limited, and an example thereof includes a method in which a layer-forming composition containing gelatin and a specific polymer is applied on a transparent film substrate and then subjected to a heat treatment as necessary.

[0297] The layer-forming composition may contain a solvent as necessary. Examples of the solvent include the solvents used in the above-mentioned photosensitive layer-forming composition.

[0298] The thickness of the layer not containing silver halide is not particularly limited, and is often 0.05 μm or more. From the perspective of better adhesion of the silver fine wire, it is preferably more than 1.0 μm, and more preferably 1.5 μm or more. The upper limit is not particularly limited, but is preferably less than 3.0 μm.

[0299] <Process I>

[0300] The method for producing an antenna of the present invention may include step I of forming a protective layer containing gelatin and a specific polymer on the photosensitive layer containing silver halide after step A and before step B. Providing the protective layer can improve scratch prevention and mechanical properties of the photosensitive layer.

[0301] The ratio of the mass of the specific polymer to the mass of gelatin (mass of specific polymer / mass of gelatin) in the protective layer is not particularly limited, but is preferably greater than 0 and less than 2.0, and more preferably greater than 0 and less than 1.0.

[0302] Furthermore, the content of the specific polymer in the protective layer is not particularly limited, but is preferably more than 0 g / m 2 And 0.3g / m 2 Below, more preferably 0.005 to 0.1 g / m 2 .

[0303] The method for forming the protective layer is not particularly limited, and examples thereof include a method in which a protective layer-forming composition containing gelatin and a specific polymer is applied on the silver halide-containing photosensitive layer and then subjected to a heat treatment as necessary.

[0304] The protective layer forming composition may contain a solvent as needed. Examples of the solvent include the solvents used in the above-mentioned photosensitive layer forming composition.

[0305] The thickness of the protective layer is not particularly limited, but is preferably 0.03 to 0.3 μm, more preferably 0.075 to 0.20 μm.

[0306] In addition, the above-mentioned step H, step A and step I can be simultaneously performed by simultaneous multi-layer coating.

[0307] <Other Manufacturing Methods of Antennas>

[0308] In the manufacturing method of the antenna, the manufacturing method of the silver fine wire is not limited to the above-mentioned manufacturing method, and a known method can be used. For example, a method of exposing and developing a photoresist film on a foil formed on the surface of a transparent film substrate to form a resist pattern, and etching the silver foil exposed from the resist pattern can be cited. In addition, a method of printing a slurry containing silver particles or silver nanowires on the surface and back of a transparent film substrate and silver-plating the slurry can be cited. In addition, a method of forming silver fine wires by pattern printing an ink containing silver particles or silver nanowires on the surface of a transparent film substrate using an inkjet method can be cited. In addition, a method of pre-forming a patterned groove structure on the surface of a transparent film substrate and burying a slurry containing silver particles or silver nanowires in the groove by screen printing can be cited.

[0309] The basic structure of the present invention is as described above. Although the antenna of the present invention has been described in detail above, the present invention is not limited to the above-described embodiment, and various improvements or changes can be made without departing from the gist of the present invention.

[0310] Example

[0311] Below, enumerate embodiment, further specific description is given to the feature of the present invention. The material, reagent, amount of substance and its ratio and operation etc. shown in the following examples can be appropriately changed without departing from the scope of the gist of the present invention. Therefore, the scope of the present invention is not limited to the following examples.

[0312] In this example, transmission loss, transmission visibility, and reflection visibility were evaluated as evaluation items for Examples 1 to 17 and Comparative Examples 1 to 3. Hereinafter, Examples 1 to 17 and Comparative Examples 1 to 3 will be described. Transmission visibility and reflection visibility are evaluations of visibility.

[0313] <Example 1>

[0314] (Preparation of Silver Halide Emulsion)

[0315] In the following liquid 1 maintained at 38°C and pH 4.5, 90% of the following liquids 2 and 3 were added over 20 minutes while stirring the following liquid 1, thereby forming 0.16μm core particles. Next, the following liquids 4 and 5 were added to the obtained solution over 8 minutes, and the remaining 10% of the following liquids 2 and 3 were further added over 2 minutes to grow the core particles to 0.21μm. 0.15g of potassium iodide was further added to the obtained solution, and the particle formation was completed after aging for 5 minutes.

[0316] 1 fluid:

[0317]

[0318] 2 fluids:

[0319] 300ml water

[0320] Silver nitrate 150g

[0321] 3 fluids:

[0322]

[0323] 4 fluids:

[0324] Water 100ml

[0325] Silver nitrate 50g

[0326] 5. Liquid:

[0327]

[0328] Afterwards, water washing was performed by flocculation method according to the conventional method. Specifically, the temperature of the solution obtained above was lowered to 35°C, and the pH was lowered with sulfuric acid until the silver halide precipitated (the pH was within the range of 3.6±0.2). Then, about 3 liters of supernatant were removed from the obtained solution (first water washing). Then, 3 liters of distilled water were added to the solution from which the supernatant was removed, and sulfuric acid was added until the silver halide precipitated. The upper 3 liters of supernatant were removed from the obtained solution again (second water washing). The same operation as the second water washing was further repeated once (third water washing), and the water washing and desalting process was completed. The emulsion after water washing and desalting was adjusted to pH 6.4 and pAg 7.5, and 2.5 g of gelatin, 10 mg of sodium benzenethiosulfonate, 3 mg of sodium benzenethiosulfinate, 15 mg of sodium thiosulfate and 10 mg of chloroauric acid were added, and chemical sensitization was performed at 55°C to obtain the best sensitivity. Then, 100 mg of 1,3,3a,7-tetraazaindene as a stabilizer and 100 mg of PROXEL (trade name, manufactured by ICI Co., Ltd.) as a preservative were added to the obtained emulsion. The finally obtained emulsion was a silver chlorobromide cubic grain emulsion containing 0.08 mol % of silver iodide, with a ratio of silver chlorobromide of 70 mol % of silver chloride and 30 mol % of silver bromide, an average particle size (equivalent spherical diameter) of 0.12 μm, and a coefficient of variation of 9%.

[0329] (Preparation of Photosensitive Layer-Forming Composition)

[0330] To the above emulsion, 1,3,3a,7-tetraazaindene (1.2×10 -4 mol / mol Ag), hydroquinone (1.2×10 -2 mol / mol Ag), citric acid (3.0×10 -4 mol / mol Ag), 2,4-dichloro-6-hydroxy-1,3,5-triazine sodium salt (0.90 g / mol Ag) and a trace amount of a hardener were added to obtain a composition. Next, the pH of the composition was adjusted to 5.6 using citric acid.

[0331] A polymer latex (the ratio of the mass of the dispersant to the mass of the polymer 1 (the mass of the dispersant / the mass of the polymer 1, in g / g) was 0.02 and the solid content was 22% by mass) containing a dispersant composed of a polymer represented by the following (P-1) and dialkylphenyl PEO (PEO is the abbreviation of polyethylene oxide) sulfate and water was added to the above composition in such a manner that the ratio of the mass of the polymer 1 in the composition to the total mass of gelatin (the mass of the polymer 1 / the mass of the gelatin, in g / g) was 0.25 / 1, thereby obtaining a polymer latex composition. In the polymer latex composition, the ratio of the mass of gelatin to the mass of silver derived from silver halide (the mass of gelatin / the mass of silver derived from silver halide, in g / g) was 0.11.

[0332] EPOXY RESIN DY 022 (trade name: manufactured by Nagase ChemteX Corporation) was further added as a crosslinking agent. The amount of the crosslinking agent added was adjusted so that the amount of the crosslinking agent in the silver halide-containing photosensitive layer described later would be 0.09 g / m 2 .

[0333] As described above, a photosensitive layer-forming composition was prepared.

[0334] In addition, polymer 1 was synthesized with reference to Japanese Patent Nos. 3305459 and 3754745.

[0335] [Chemical formula 5]

[0336]

[0337] The above polymer latex was applied to both sides of a polyethylene terephthalate film ("Fujifilm Corporation roll-shaped long film") with a thickness of 100 μm prepared as a transparent film substrate, and a primer layer with a thickness of 0.05 μm was provided. This treatment was performed by roll-to-roll, and the following treatments (processes) were performed by roll-to-roll in the same manner. In addition, the roll width at this time was 1 m and the length was 1000 m. In addition, the relative dielectric constant εr of the polyethylene terephthalate film was 3.0 and the dissipation factor was 0.003.

[0338] (Process H1, Process A1, Process I1)

[0339] Next, on the undercoat layer on one side of the polyethylene terephthalate film, the composition for forming a layer containing no silver halide, which is a mixture of the polymer latex and gelatin, the composition for forming a photosensitive layer, and the composition for forming a protective layer, which is a mixture of polymer latex and gelatin, are simultaneously applied in multiple layers to form a layer containing no silver halide, a photosensitive layer containing silver halide, and a protective layer on the undercoat layer. On the remaining undercoat layer on the other side, a layer containing no silver halide, a photosensitive layer containing silver halide, and a protective layer are formed as described above.

[0340] The thickness of the layer not containing silver halide was 2.0 μm, the mixing mass ratio of polymer 1 to gelatin in the layer not containing silver halide (polymer 1 / gelatin) was 2 / 1, and the content of polymer 1 was 1.3 g / m 2 .

[0341] The thickness of the silver halide-containing photosensitive layer was 2.5 μm, the mixing mass ratio of polymer 1 to gelatin (polymer 1 / gelatin) in the silver halide-containing photosensitive layer was 0.25 / 1, and the content of polymer 1 was 0.19 g / m 2 .

[0342] The thickness of the protective layer was 0.15 μm, the mixing mass ratio of polymer 1 to gelatin in the protective layer (polymer 1 / gelatin) was 0.1 / 1, and the content of polymer 1 was 0.015 g / m 2 .

[0343] (Process B1)

[0344] The pattern exposure was performed on the prepared photosensitive layer as follows. In the pattern exposure, a concave mirror (dichroic mirror) composed of a dielectric multilayer film that transmits infrared rays was used to focus the light emitted by the ultra-high pressure mercury lamp and pass it through a fly-eye lens, and then pass it through a concave mirror optical system to set it as a quasi-parallel light source. The photosensitive material was exposed on both sides simultaneously by using mask 1 and mask 2, and the intermittent transportation of the photosensitive material and the simultaneous exposure of both sides by using masks 1 and 2 were repeated, thereby implementing the relevant pattern exposure. Mask 1 is formed with Fig.17 The antenna pattern 11 and the antenna array pattern 31 of the dummy pattern 17a are shown. Fig.18 The ground plane pattern 16a is shown.

[0345] Furthermore, the antenna pattern 11, the dummy pattern 17a, and the ground plane pattern 16a are composed of the same grid pattern, the line width of the rhombus grid is set to 2.1 μm, and the pitch of the rhombus grid is set to 70.7 μm. In pattern exposure, the positions of mask 1 and mask 2 when both sides are simultaneously exposed are adjusted so that the grid patterns on the upper and lower surfaces overlap at half pitch (equal intervals).

[0346] After exposure, the obtained sample is polarity developed with the developer described later, and further developed with a fixing solution (trade name: CN16X uses N3X-R: manufactured by Fujifilm Corporation), and then rinsed with pure water at 25°C and dried. An antenna array pattern 31 having an antenna pattern 11 and a dummy pattern 17a is formed on the surface of the polyethylene terephthalate film serving as a transparent film substrate, thereby obtaining a sample A having a ground plane pattern 16a formed on the back.

[0347] Formed on sample A Fig.17 The antenna array pattern 31 shown is used to form an antenna array. In the antenna array pattern 31, four antenna patterns 11 are arranged at intervals J. The interval J is 5 mm. The antenna pattern 11 is used to form an antenna. The antenna pattern 11 has an antenna element pattern 11a and a power supply line pattern 11b. The antenna part pattern 11c is formed by the antenna element pattern 11a and the power supply line pattern 11b. In the antenna element pattern 11a, the length equivalent to the side length W of the antenna element 14 is set to 3 mm, the length equivalent to the side length L is set to 3 mm, and the insertion amount R is set to 0.75 mm. In the power supply line pattern 11b, the length equivalent to the power supply line 15 is set to 5 mm, and the length equivalent to the width of the power supply line 15 is set to 0.25 mm. In addition, the side length Rt of the portion where the power supply line pattern 11b is provided is set to 1 mm.

[0348] The dummy pattern 17a is provided continuously without any gap around the antenna pattern 11. The dummy pattern 17a is used to form a dummy pattern portion.

[0349] Fig.18 The illustrated ground plane pattern 16a is composed of only a mesh pattern. The ground plane pattern 16a is used to form a ground portion.

[0350] Furthermore, the mesh pattern forming the antenna pattern, the dummy pattern and the ground plane pattern is composed of a diamond grid 23 (reference Fig.19 As described above, in the rhombus lattice 23, the length Wd of one side corresponding to the pitch is set to 70.7 μm, and the length Wp of the diagonal line is set to 100 μm. Fig.19 As shown, in order to set the antenna pattern 11 and the dummy pattern 17a to be non-conductive, a disconnection portion 21 is provided on the rhombus lattice 23a around the antenna pattern 11. The disconnection portion 21 is provided at the center of one side of the rhombus lattice 23a, and the length Wb of the disconnection portion 21 is set to 5 μm.

[0351] in addition, Fig.17 and Fig.18 In the figure, the size of the grid pattern is schematically indicated and is different from the actual size.

[0352] And, Fig.17 The antenna array pattern 31 and Fig.18 The ground plane patterns 16a shown are all set to be rectangular patterns with a length Hp and a width Vp. The length Hp is set to 37 mm, and the width Vp is set to 15 mm.

[0353] (Composition of developer)

[0354] The following compounds are contained in 1 liter (L) of the developer.

[0355]

[0356] The obtained sample A was immersed in warm water at 50° C. for 180 seconds, and then the water was removed by air showering, followed by natural drying.

[0357] (Process C1)

[0358] The sample A obtained in step B1 was placed in a superheated steam treatment tank at 110° C. and allowed to stand for 30 seconds to be subjected to superheated steam treatment. The steam flow rate at this time was 100 kg / h.

[0359] (Process D1)

[0360] The sample A obtained in step C1 was immersed in a hypochlorous acid-containing aqueous solution (25° C.) for 30 seconds. The sample A was taken out from the aqueous solution and washed by immersing it in warm water (liquid temperature: 50° C.) for 120 seconds. Thereafter, water was removed by air showering and the sample was dried naturally.

[0361] The hypochlorous acid-containing aqueous solution used was prepared by diluting Haiter manufactured by Kao Corporation by 2 times.

[0362] (Process E1)

[0363] The sample A obtained in step D1 was immersed in a plating solution A (30° C.) having the following composition for 270 seconds. The sample A was taken out from the plating solution A and was immersed in warm water (liquid temperature: 50° C.) for 120 seconds for washing.

[0364] The composition of the plating solution A (total amount 1200 ml) is as follows. In addition, the pH of the plating solution A was 9.5, which was adjusted by adding a predetermined amount of potassium carbonate (manufactured by FUJIFILM Wako Pure Chemical Corporation). In addition, the following components used were all manufactured by FUJIFILM Wako Pure Chemical Corporation. No line width change was found before and after the plating treatment.

[0365] (Composition of Plating Solution A)

[0366]

[0367]

[0368] (Process F1)

[0369] Sample A obtained in step E1 was subjected to a calendering treatment at a pressure of 30 kN using a calendering device composed of a combination of a metal roll and a resin roll. The calendering treatment was performed at room temperature.

[0370] (Process G1)

[0371] The sample A obtained in step F1 was placed in a superheated steam treatment tank at 110°C and allowed to stand for 30 seconds for superheated steam treatment. Thus, a transparent film substrate was obtained in which an antenna array was formed by forming an antenna and a dummy pattern portion based on the antenna pattern 11 and the dummy pattern 17a on the surface of the polyethylene terephthalate film as a transparent film substrate, and a ground portion based on the ground plane pattern 16a was formed on the back. Hereinafter, the transparent film substrate is referred to as a transparent film substrate having an antenna array formed thereon. Regarding the size of the transparent film substrate having an antenna array formed thereon, the length corresponding to the length Hp of the antenna array pattern 31 is 60 mm, and the width corresponding to the width Vp is 25 mm.

[0372] In addition, the steam flow rate at this time is 100 kg / h. The obtained grid pattern area is as follows Figure 4 The grid-like layer of a diamond lattice formed by silver thin wires is shown. The wire width of the thin wires is 2.1 μm, and the thickness of the conductive thin wires is 1.5 μm.

[0373] Regarding the surface roughness Rq(A) of the thin wire, the thin wire was cut into a cross section with a length of about 20 μm in the longitudinal direction with a slicer, and the exposed cross section of the thin wire was carbon-evaporated to impart conductivity, and a cross-sectional image was obtained using a scanning electron microscope. Using the image processing software ImageJ, the obtained cross-sectional image was analyzed to obtain the surface roughness. The measurement range was set to 20 μm, and cross-sectional images of any 5 locations of the thin wire were obtained to obtain each surface roughness, and the arithmetic mean of the surface roughness at the 5 locations was taken as the surface roughness Rq(A). The surface roughness Rq(A) of Example 1 is 0.08 μm.

[0374] Regarding the surface roughness Rq(B) of the above-mentioned fine wire, similarly to the above-mentioned surface roughness Rq(A), the fine wire is cut into a cross section with a length of about 20 μm in the longitudinal direction by a slicer, and then the exposed cross section of the fine wire is carbon-evaporated to impart conductivity, and a cross-sectional image is obtained using a scanning electron microscope. Using the image processing software ImageJ, the obtained cross-sectional image is analyzed to obtain the surface roughness. The measurement range is set to 20 μm, and cross-sectional images of any 5 locations of the fine wire are obtained to obtain each surface roughness, and the arithmetic mean of the surface roughness at the 5 locations is taken as the surface roughness Rq(B). The surface roughness Rq(B) of Example 1 is 0.15 μm.

[0375] The cross section of the obtained sample A was cut with a microtome, subjected to carbon vapor deposition, and then observed using a S-5200 SEM manufactured by Hitachi High-Tech Corporation. The observation mode was a reflected electron mode, and the acceleration voltage was set to 5 kV.

[0376] According to the observation image of the vertical cross section of the thin wire obtained by the scanning electron microscope, the ratio (volume %) of the silver particles was 70 volume %.

[0377] <Examples 2 to 17, Comparative Examples 1 to 3>

[0378] In Examples 2 to 17 and Comparative Examples 1 to 3, the line width was adjusted by adjusting the exposure time in step B1 to change the exposure amount.

[0379] The "wire width" and "thickness of the thin wire" recorded in Table 1 were measured after the heated water vapor treatment in step G1. The wire width and thickness of the thin wire were measured using the S-5200 SEM manufactured by Hitachi High-Tech Corporation. For the measurement of the wire width and thickness of the thin wire, the cross section of the thin wire was cut with a slicer, and then carbon was evaporated on the exposed cross section. Five random points of one thin wire were selected, and the arithmetic mean of the line width obtained from the images of each vertical cross section observed with a scanning electron microscope was used as the line width. Similarly to the line width, the thickness of the thin wire was the arithmetic mean of the thickness of the five points equivalent to the thickness of one thin wire.

[0380] Furthermore, the silver particle size was adjusted by adjusting the exposure amount through the heated water vapor treatment in step G1.

[0381] By lengthening the plating treatment time of step E1, the particles on the outside grow and the volume % of the silver particles also increases. Therefore, by adjusting the exposure amount and plating treatment time in step B1, the line width of the fine line, the thickness of the fine line and the volume fraction of the silver particles are adjusted.

[0382] In addition, in Examples 2 to 17 and Comparative Examples 1 to 4, the surface roughness Rq(A) and the surface roughness Rq(B) were adjusted by adjusting the combination of rollers used for the calendering treatment in Step F1, the material of the co-carrier pad, the presence or absence of the co-carrier pad, the pressure and the temperature.

[0383] In Comparative Example 3, electroless copper plating was performed during the plating treatment of step E1. A commercially available electroless copper plating solution can be used as the electroless copper plating solution. In the preparation of Comparative Example 3, "OIC ACCELERATOR" and "OIC COPPER" manufactured by OKUNO Chemical Industries Co., Ltd. were used. After immersion in OIC ACCELERATOR (25°C) for 3 minutes and in OIC COPPER (55°C) for 10 minutes, the sample was rinsed with pure water at 25°C. The other steps were prepared in the same manner as in the other examples.

[0384] <Evaluation>

[0385] Hereinafter, transmission loss, transmission visibility, and reflection visibility as evaluation items will be described.

[0386] (Transmission loss)

[0387] The transmission loss was evaluated by the insertion loss. The evaluation criteria of the transmission loss based on the insertion loss are shown below. Among the following 1 to 5, 3 or more is preferred, 4 or more is more preferred, and 5 is further preferred.

[0388] Insertion loss is the power loss propagated from one terminal to the other terminal in a high-frequency circuit composed of a two-port network, expressed in dB (decibel).

[0389] Regarding transmission loss, Fig. 20 and Fig.21 Transmission loss measurement samples are shown.

[0390] Fig. 20 The transmission loss measurement sample 50 shown in FIG. 1 has a microstrip line transmission line 54 (hereinafter referred to as transmission line 54) with a width Wm formed on the surface 52a of a transparent film substrate 52. Fig.21 As shown in FIG. 1 , the transmission line 54 is arranged in a straight line. The width Wm of the transmission line 54 is set to 250 μm and the length is set to 40 mm. A grounding portion 56 is formed on the entire surface of the back surface 52 b. The mesh pattern of the fine lines constituting the transmission line 54 and the grounding portion 56 is set to have a Fig.19The grid pattern of the diamond lattice 23 shown in FIG. As described above, in the diamond lattice 23, the length Wd of one side corresponding to the pitch is set to 70.7 μm, and the length Wp of the diagonal is set to 100 μm. The transmission line 54 is a structure having 2.5 diamond lattices in the width direction. Full metal contact areas (touchlands) for contact terminals are provided at both ends of the transmission line 54. The width of the contact area is set to 250 μm, and the length is set to 2 mm. The width of the contact area is the same as the width Wm of the transmission line 54.

[0391] Transmission loss measurement sample 50 (reference Fig. 20 ) was set on a universal test fixture (ANRITSU CORPORATION, model 3680V), and a vector network analyzer (Keysight Technologies, N5247A) was used to determine the insertion loss (dB / cmm) at 28 GHz. In addition, the impedance at 28 GHz was confirmed to be 50Ω using the Smith chart of S11 of the S parameter.

[0392] 5: Insertion loss < 0.5dB

[0393] 4: 0.5dB≤Insertion loss<0.8dB

[0394] 3: 0.8dB≤Insertion loss<1.2dB

[0395] 2: 1.2dB≤Insertion loss<1.5dB

[0396] 1: 1.5dB ≤ insertion loss

[0397] (Transmission visual recognition)

[0398] Regarding the transmission visual recognition, in the antenna pattern part, the total light transmittance of the transparent film substrate before the mesh pattern is formed and the total light transmittance of the transparent film substrate after the mesh pattern is formed are measured. The opening ratio (%) is calculated as follows, and the evaluation is performed using the opening ratio. The following shows the evaluation criteria for the transmission visual recognition based on the opening ratio. Among the following 1 to 5, 3 or more is preferred, 4 or more is more preferred, and 5 is further preferred.

[0399] Regarding the aperture ratio, first, the total light transmittance of the transparent film substrate after the grid pattern is formed is measured. Then, for the antenna, the total light transmittance of the transparent film substrate after the grid pattern is formed is measured in 5 areas. The areas of the 5 transparent film substrates can be the same or different in size as long as the acquisition positions on the transparent film substrate are different. Then, the aperture ratio is calculated using the following formula. The average value of the 5 aperture ratios calculated is taken as the aperture ratio.

[0400] Aperture ratio = ((total light transmittance of the transparent film substrate after the mesh pattern is formed) / (total light transmittance of the transparent film substrate before the mesh pattern is formed)) × 100 (%)

[0401] The total light transmittance was measured using a spectrophotometer CM-3600A (manufactured by KONICA MINOLTA, INC.).

[0402] 5: Opening rate ≥ 85%

[0403] 4: 80% ≤ opening rate < 85%

[0404] 3: 75% ≤ opening rate < 80%

[0405] 2: 70% ≤ opening rate < 75%

[0406] 1: Opening rate <70%

[0407] (Reflection Vision)

[0408] A laminated body was obtained by laminating a transparent film substrate having an antenna array in the order of glass plate / transparent film substrate having an antenna array / polyethylene terephthalate film. In addition, the polyethylene terephthalate film was used for the transparent film substrate and had a thickness of 100 μm. In the laminated body, the transparent film substrate having an antenna array was arranged so that the surface having the antenna formed was located on the glass plate side. In the glass and the polyethylene terephthalate film, the corresponding Fig.17 The length Hp of the antenna array pattern 31 shown is set to 60 mm, and the width corresponding to the width Vp is set to 25 mm. Also, the transparent film substrate on which the antenna array is formed is 60 mm in length and 25 mm in width, similar to glass and polyethylene terephthalate films.

[0409] Next, the stack was vertically erected and irradiated with LED (Light Emitting Diode) light of 2000 lux from an angle of 30° to 60° obliquely above the glass surface. Ten observers visually observed the transparent film substrate with the antenna array formed thereon from an angle of 60° to 30° obliquely below the glass surface, and the reflection visual recognition was evaluated according to the following criteria. As an evaluation of the reflection visual recognition, 3 or more is preferred, 4 or more is more preferred, and 5 is further preferred among the following 1 to 5. In addition, in the evaluation of the reflection visual recognition, the mesh pattern constituting the antenna and the ground portion was not visually recognized.

[0410] 5: When the transparent film substrate on which the antenna array was formed was observed from a distance of 15 cm, the outline of the mesh formation portion was not visually recognized.

[0411] 4: When observing the transparent film substrate on which the antenna array was formed from a distance of 30 cm, the number of observers who visually recognized the outline of the mesh formation portion was 0 or 1.

[0412] 3: When observing the transparent film substrate on which the antenna array was formed from a distance of 30 cm, 2 to 4 observers visually recognized the outline of the mesh formation portion.

[0413] 2: When observing the transparent film substrate on which the antenna array is formed from a distance of 30 cm, five or more observers visually recognized the outline of the mesh formation portion.

[0414] 1: When observing the transparent film substrate on which the antenna array is formed from a distance of 50 cm, five or more observers visually recognized the outline of the mesh formation portion.

[0415]

[0416] As shown in Table 1, Examples 1 to 17 achieved both low transmission loss and visibility compared to Comparative Examples 1 to 3. In addition, it was confirmed that all Examples 1 to 17 functioned as millimeter waveband antennas.

[0417] In Comparative Example 1, the line width of the thin line is thin and the transmission loss is large, and it is not possible to achieve both low transmission loss and visual recognition.

[0418] In Comparative Example 2, the line width of the thin line is large, and the transmission visibility and reflection visibility are poor, and the transmission loss and visibility cannot be achieved at the same time.

[0419] Comparative Example 3 uses a thin copper wire, and the reflection visibility is poor, and both low transmission loss and visibility cannot be achieved.

[0420] In addition, according to Examples 1 and 10, and Examples 2 and 9, it can be seen that the transmission loss of the examples with a large proportion of silver particles is excellent. According to Examples 12 to 15, it can be seen that the transmission loss or reflection visual recognition of the examples with surface roughness Rq(A) within the preferred range is excellent. As shown in Example 13, even if the surface roughness Rq(A) on the visual recognition side is large, as long as the surface roughness Rq(A) and |Rq(B)-Rq(A)| are within the preferred range, the reflection visual recognition is also good.

[0421] Furthermore, according to Examples 3, 16, and 17, it is understood that there is a tendency that when the transparent film substrate is thick, the transmission loss is reduced, and conversely, when the transparent film substrate is thin, the transmission loss is increased.

[0422] Explanation of symbols

[0423] 10, 10a, 10b, 10c, 10d-antenna, 11-antenna pattern, 11a-antenna element pattern, 11b-power supply line pattern, 11c-antenna portion pattern, 12, 52-transparent film substrate, 12a-surface, 12b-back surface, 13-antenna portion, 14-antenna element, 15-power supply line, 16-ground portion, 16a-ground plane pattern, 17-dummy pattern portion, 17a-dummy pattern, 20-fine line, 20a-surface, 20d-surface, 21-broken line portion, 22-opening portion, 23, 23a-diamond lattice, 24-polymer, 26-silver particles, 30, 30a, 30b, 30c-antenna array, 31-antenna array pattern, 32-antenna element, 33-notch, 34, 35-fine wire, 40a-first calendering roller, 40b-second calendering roller, 42-co-carrying pad, 50-transmission loss measurement sample, 52a-surface, 52b-back side, 54-microstrip line transmission line (transmission line), 56-ground part, J, Gt-interval, L, L1, L2, Rt-length, Hp-length, R-insertion amount, Vp-width, W, W1, W2, Wb, Wp-length, Wd-length of one side, Ws-line width, h-thickness, t-thickness.

Claims

1. An antenna, comprising: Transparent film substrate; an antenna element disposed on one of the two surfaces of the transparent film substrate; and A grounding portion is provided on the other of the two surfaces of the transparent film substrate. The antenna element and the ground portion are formed of a mesh pattern formed by silver fine wires. The line width of the thin line is greater than 1.0 μm and less than 5.0 μm, The transparent film substrate has a thickness of 30 μm or more and 300 μm or less, The silver fine wires contain a plurality of silver particles dispersed in a particulate hydrophobic polymer. The ratio of the plurality of silver particles contained in the silver thin wire is 70 volume % or more, When the transparent film substrate is observed from one side or the other side, the surface roughness of the fine line on the one side or the other side on the observation side is set to Rq(A), and the surface roughness of the transparent film substrate side of the fine line on the other side or the one side on the side opposite to the observation side is set to Rq(B), 0.05μm≤Rq(A)≤0.35μm is satisfied, and |Rq(B)-Rq(A)|≤0.25μm is satisfied.

2. The antenna according to claim 1, comprising a power supply line provided on the one side of the transparent film substrate, The power supply line is formed of a mesh pattern formed by the silver thin wires, and the line width of the thin wires is greater than or equal to 1.0 μm and less than 5.0 μm.

3. The antenna according to claim 1 or 2, wherein: The line width of the thin line is greater than or equal to 2.1 μm and less than or equal to 3.7 μm.

4. The antenna according to claim 1 or 2, wherein: The thickness of the thin wire is 0.5 μm or more and less than 5.0 μm.

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