Glass body

Abstract

To provide a glass body capable of preventing a radio wave transmission area from being conspicuous in appearance and highly holding performance due to a conductive film.SOLUTION: A glass body includes a first glass plate having a first surface and a second surface on the side opposite to the first surface. The plate surface of at least one of the first and second surfaces includes: a plurality of radio wave transmission areas 21 capable of transmitting a radio wave and separated from each other; and a conductive film area 22 entirely covered with a conductive film 23 having radio wave blockage around the radio wave transmission area 21. A patterning part 26 including a plurality of radio wave passage parts 24 capable of passing the radio wave and separated to each other and a conductive film part 25 having the conductive film 23 formed between adjacent radio wave passage parts 24 is formed in each radio wave transmission area 21.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a glass body. [Background technology]

[0002] Glass bodies having heat insulating or heat shielding properties, in which a Low-E film (low emissivity film) is formed on the surface of the window glass of a vehicle or building, are known (see, for example, Patent Document 1). This Low-E film has a problem in that it has low transmittance (blocking properties) for radio waves in the frequency band of several hundred MHz to several tens of GHz.

[0003] Therefore, the glass body described in Patent Document 2 has openings in the Low-E film consisting of multiple parallel lines, and by specifying the ratio between the length of these multiple lines and the area of ​​the Low-E film, radio wave transmittance is increased for radio waves in the frequency band of several hundred MHz to several tens of GHz.

[0004] Furthermore, the glass body described in Patent Document 3 has a plurality of discontinuous islands provided in a first film region having a Low-E film, and this first film region has radio wave transparency. Patent Document 3 also discloses an embodiment of a double-glazed glass panel in which a first film region is provided on the second surface of a first glass plate, and an antenna is provided on the fourth surface of a second glass plate at a position facing the first film region. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-226235 [Patent Document 2] International Publication No. 2020 / 054762 [Patent Document 3] International Publication No. 2021 / 095885 Summary of the Invention [Problem to be solved by the invention]

[0006] The opening described in Patent Document 2 and the first film region described in Patent Document 3 are configured to have a shape that ensures radio wave transparency as a radio wave transparent region. In particular, the opening described in Patent Document 2 has multiple parallel lines provided in the conductive film (Low-E film), which is easily visible as a striped pattern, significantly affecting the appearance. Furthermore, the opening described in Patent Document 2 and the first film region described in Patent Document 3 ensure radio wave transparency over a wide frequency band by removing a large portion of the conductive film (Low-E film), which ensures an opening area, and therefore the performance (thermal insulation or heat shielding properties and radio wave blocking properties) of the conductive film in the glass body is easily impaired.

[0007] Therefore, there is a demand for a glass body that has an inconspicuous radio wave transmitting area and can maintain high performance due to the conductive film. [Means for solving the problem]

[0008] A characteristic configuration of a glass body according to the present invention includes a first glass plate having a first surface and a second surface opposite to the first surface, wherein at least one of the first surface and the second surface includes a plurality of radio wave transparent regions that are spaced apart and allow radio waves to pass therethrough, and a conductive film region that is entirely covered around the radio wave transparent region with a conductive film that has a property of blocking the radio waves, the conductive film is a Low-E film, In each of the radio wave transmitting regions, a patterning section is formed which has a plurality of radio wave passing sections spaced apart from each other that allow the radio waves to pass therethrough, and a conductive film section in which the conductive film is formed between adjacent radio wave passing sections. The patterning portion is formed of a thin line having a line width of 5 μm or more and 30 μm or less, the width of the patterning portion is 2 mm or more and 5 mm or less, and the interval between adjacent thin lines is 500 μm or more and 1 mm or less. It's at the point.

[0009] Radio waves passing through the glass body have high radio wave intensity in the area facing the area of ​​the first glass sheet where there is no conductive film, so the glass body has good reception sensitivity for radio waves in a specified frequency band. Therefore, to increase the radio wave reception area in the glass body, it is sufficient to not provide a conductive film on the glass body. However, in that case, the glass body loses the performance provided by the conductive film (thermal insulation, heat shielding, and radio wave blocking), resulting in a trade-off between the performance provided by the conductive film and radio wave transmittance.

[0010] Therefore, the glass body of this configuration is provided with a plurality of spaced apart radio wave transparent regions that are permeable to radio waves, and a conductive film region that is entirely covered with a conductive film around the radio wave transparent region, and further, the radio wave transparent region has a plurality of spaced apart radio wave passing portions that allow radio waves to pass, and a conductive film portion in which a conductive film is formed between adjacent radio wave passing portions. In other words, by providing the conductive film portions even in the radio wave transparent region, it is possible to maintain high performance of the conductive film, and by providing a plurality of radio wave passing portions in each of the plurality of radio wave transparent regions, radio wave transparency is improved.

[0011] Furthermore, the radio wave transmitting region of this configuration has a patterned portion formed therein, which includes multiple radio wave transmitting portions and a conductive film portion between adjacent radio wave transmitting portions. In other words, the radio wave transmitting region has a predetermined pattern in which portions without a conductive film (radio wave transmitting portions) and portions covered with a conductive film (conductive film portions) are mixed. This reduces the impact on appearance between the conductive film portion and the radio wave transmitting region. Furthermore, by setting the shape of the patterned portion, frequency selectivity can be imparted. As a result, the glass body has a good appearance because the radio wave transmitting region is less noticeable on the outside, and can also have frequency selectivity. In this way, the glass body has a radio wave transmitting region that is less noticeable on the outside and can maintain high performance due to the conductive film. Furthermore, as in this configuration, the patterned portion has a radio wave passing portion formed of thin lines having a line width of 1 μm or more and 100 μm or less, and if the spacing between adjacent thin lines is 200 μm or more and 3 mm or less, radio wave permeability can be ensured while minimizing the impact on appearance. Note that if the line width of the thin lines is less than 1 μm, radio wave permeability decreases, and if it is greater than 100 μm, the performance of the conductive film tends to decrease. Furthermore, if the spacing between adjacent thin lines is less than 200 μm, the patterned portion becomes more visible externally and the performance of the conductive film decreases, and if it is greater than 3 mm, radio wave permeability tends to decrease. Furthermore, if the conductive film is a Low-E film as in this configuration, it is possible to improve the heat insulating or heat blocking performance while ensuring radio wave transparency.

[0012] Another characteristic feature is that each of the radio wave transmitting areas has a common symmetrical shape configured to transmit only the radio waves having a predetermined frequency band.

[0013] In this configuration, the radio wave transmitting areas each have a common symmetrical shape, which makes it easier for the radio wave transmitting portion to maintain frequency selectivity for the radio waves that pass through it, thereby forming a radio wave transmitting area that is optimal for radio waves in a predetermined frequency band.

[0014] Another characteristic feature is that the width of the conductive film region, which is the shortest distance between adjacent radio wave transmitting regions, is uniform.

[0015] In this configuration, by making the width of the conductive film area (conductive film) that is the shortest distance between multiple adjacent radio wave transmission areas uniform, it is possible to appropriately achieve both the performance of the conductive film and radio wave transmission.

[0016] Another characteristic feature is that the width of the conductive film region, which is the shortest distance between adjacent radio wave transmitting regions, is 0.5 mm or more and 10 mm or less.

[0017] As in this configuration, if the width of the conductive film region, which is the shortest distance between adjacent radio wave transmitting regions, is 0.5 mm to 10 mm, it is possible to ensure radio wave transparency while minimizing the impact on appearance. If the width of the conductive film region, which is the shortest distance between adjacent radio wave transmitting regions, is less than 0.5 mm, the performance of the conductive film will decrease, and if it is more than 10 mm, radio wave transparency will likely decrease.

[0018] Another characteristic feature of the radio wave transmitting area is that the maximum length of a line segment passing through the center of the area is 0.5 mm or more and 30 mm or less.

[0019] As in this configuration, if the maximum length of the line segment passing through the center of the radio wave transparent area is 0.5 mm or more and 30 mm or less, radio wave transparency can be ensured while minimizing the impact on appearance. If the maximum length of the line segment passing through the center is less than 0.5 mm, radio wave transparency decreases, and if it is more than 30 mm, the performance of the conductive film is likely to decrease.

[0020]

[0021]

[0022] Another characteristic feature is that the plurality of thin lines are formed parallel to or concentric with the outline of the radio wave transmitting area.

[0023] As in this configuration, if multiple thin lines are formed parallel to or concentric with the outline of the radio wave transmitting area, patterning processing is easy in the radio wave transmitting area, and radio wave transmittance in a specified frequency band is improved.

[0024] Another characteristic feature is that the radio wave transmitting area is annular.

[0025] If the radio wave transmitting region is annular, as in this configuration, the radio wave transmittance for radio waves having the desired frequency band is improved, and a glass body can be constructed that has frequency selectivity that transmits only the desired frequency band.

[0026] Another characteristic feature is that the visible light transmittance of the radio wave transmitting region is set to be 1.1 times or less the visible light transmittance of the conductive film region.

[0027] As in this configuration, when the visible light transmittance of the radio wave transmitting region is 1.1 times or less than the visible light transmittance of the conductive film region, the influence on the appearance between the conductive film region and the radio wave transmitting region can be reliably reduced.

[0028]

[0029]

[0030] Another characteristic configuration is that the glass panel further includes a second glass plate having a third surface facing the second surface and a fourth surface opposite the third surface, and a spacer in contact with the second surface and the third surface to form an air gap layer between the first glass plate and the second glass plate, and the radio wave transmitting area is formed on the second surface or the third surface.

[0031] In double-glazing glass with this configuration, the heat insulating performance can be improved by placing a Low-E film on the second surface of the first glass sheet or the third surface of the second glass sheet. In a glass body with this improved heat insulating performance, forming a radio wave transparent area on the second surface or the third surface can increase the benefits of using a glass body with the above configuration. [Brief explanation of the drawings]

[0032] [Figure 1] FIG. 1 is a plan view of a glass body according to a first embodiment. [Figure 2] FIG. 2 is a plan view showing a radio wave transmission area. [Figure 3] FIG. 3 is a cross-sectional view taken along the line III-III in FIG. 2. [Figure 4] FIG. [Figure 5] 1A and 1B are diagrams showing external photographed images of Experimental Example 1 and Comparative Example. [Figure 6] 1 is a graph showing the amount of attenuation versus frequency in Experimental Example 1 and Comparative Example 1. [Figure 7] 1 is a graph showing the amount of attenuation versus frequency in Experimental Examples 1 to 3. [Figure 8] FIG. 10 is a cross-sectional view of a glass body according to a second embodiment. [Figure 9] 9 is a cross-sectional view taken along the line IX-IX in FIG. 8. [Figure 10] 10A and 10B are diagrams illustrating the shape of a radio wave transmitting region in another form. DETAILED DESCRIPTION OF THE INVENTION

[0033] Hereinafter, embodiments of the glass body according to the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiments, and various modifications are possible without departing from the spirit of the present invention.

[0034] The glass body 100 of this embodiment can be used for various purposes, for example, as window glass for buildings, and window glass for mobile bodies such as automobiles, aircraft, ships, trains, etc. The glass body 100 may be a window glass that comes into contact with the outside air, or may be a window glass that divides a room.

[0035] As shown in Fig. 1, glass body 100 includes a first glass plate 1 whose plate surface has a rectangular outer shape. Glass body 100 includes a radio wave transmitting region 21 that can transmit radio waves corresponding to the 4G or 5G frequency band of 700 MHz to 30 GHz (wavelength 428 mm to 10 mm) that have linearity, and a conductive film region 22 in which a Low-E film 23 (an example of a conductive film) is formed around radio wave transmitting region 21.

[0036] <First embodiment: single-pane glass> As shown in FIG. 3, the first glass plate 1 has a first surface 11 and a second surface 12 opposite to the first surface 11. A Low-E film 23 (an example of a conductive film) having radio wave blocking properties is formed on at least one of the first surface 11 and the second surface 12 of the first glass plate 1. In FIGS. 1 to 3, the Low-E film 23 is formed on the second surface 12 of the first glass plate 1. The Low-E film 23 is a conductive thin film that blocks radio waves. The surface resistivity of the conductive thin film is preferably less than 20 Ω. In this case, the Low-E film 23 has high reflectance in a wavelength range from the infrared region to the radio wave region (a frequency band of several hundred MHz to several tens of GHz). Therefore, the surface of the first glass plate 1 on which the Low-E film 23 is formed has low radio wave transmittance but also low emissivity. The second surface 12 of the first glass plate 1 has a conductive film region 22 over the entire area of ​​which the Low-E film 23 is formed. Furthermore, a rectangular partitioned region 30 including a plurality of (nine in the figure) radio wave transparent regions 21 is provided in a portion (the center portion in the figure) of the second surface 12, which is the plate surface on which the Low-E film 23 is formed, by removing a portion of the Low-E film 23 using laser processing or the like. The partitioned region 30 has a plurality of radio wave transparent regions 21 spaced apart from one another. The radio wave transparent regions 21 are arranged to allow transmission of radio waves corresponding to the 44G frequency band of 700 MHz to 3.5 GHz (wavelength 428 mm to 85 mm) and the 5G frequency band of 3.6 GHz to 30 GHz (wavelength 83 mm to 10 mm), which have linear propagation. The radio wave transparent regions 21 will be described in detail later. The conductive film region 22 and the radio wave transparent regions 21 may also be provided on the first surface 11 of the first glass plate 1.

[0037] The material of the first glass plate 1 (the same applies to the second glass plate 2 described later) is not particularly limited, and a known glass plate can be used. For example, various glass plates such as heat-absorbing glass, clear glass, green glass, UV green glass, and soda-lime glass can be used. The thickness of the first glass plate 1 is not particularly limited, but for example, it is preferably 2 to 15 mm, and more preferably 2.5 to 8 mm.

[0038] <Low-E film> The Low-E film 23 is not particularly limited as long as it does not inhibit the object of the present invention, but preferably, it is a multilayer film including a layer mainly composed of silver. Also, the Low-E film 23 preferably consists of a multilayer formed by laminating two or more layers selected from a metal layer, a metal oxide layer, a metal nitride layer, and a metal oxynitride layer. A suitable example of the metal layer is a silver layer. Suitable examples of the metal oxide layer include a tin oxide layer, a titanium oxide layer, or a zinc oxide layer. A suitable example of the metal nitride layer is silicon nitride. A suitable example of the metal oxynitride layer is silicon oxynitride. The Low-E film 23 is preferably formed by a vacuum film-forming method such as a physical vapor deposition method (PVD), and particularly preferably, the sputtering method is preferred because it can form a large area uniformly. The radio wave transmission region 21 is formed, for example, by removing the Low-E film 23 by laser processing or the like after forming the Low-E film 23 on the glass plate by the sputtering method. The radio wave transmission region 21 may be formed using various masking materials. By forming the radio wave transmission region 21 by such a method, it can be easily arranged at a desired position on the glass plate.

[0039] Furthermore, the Low-E film 23 is more preferably made of a multilayer structure consisting of three or more layers selected from a tin oxide layer, a silicon nitride layer, a silicon oxynitride layer, a titanium oxide layer, a zinc oxide layer, and a silver layer, and most preferably made of three or five layers consisting of, in order from the glass plate surface, (1) a tin oxide layer (first antireflection layer), a zinc oxide layer (first antireflection layer), a silver layer (metal layer), a zinc oxide layer (second antireflection layer), and a tin oxide layer (second antireflection layer); and (2) a silicon nitride layer (first antireflection layer), a zinc oxide layer (first antireflection layer), a silver layer (metal layer), and a zinc oxide layer (second antireflection layer).

[0040] The Low-E film 23 contains a metal layer whose main component is silver. The thickness of the metal layer is preferably 5 nm to 15 nm, and more preferably 5 nm to 10 nm. When the Low-E film 23 has a metal layer whose main component is silver and has a predetermined thickness, heat radiation can be suppressed. This allows the glass body 100 to have improved heat insulating performance. Furthermore, when the thickness of the metal layer is 15 nm or less, the impact of the Low-E film 23 on the appearance can be reduced.

[0041] The Low-E film 23 preferably has a first antireflection layer on the inner side of the metal layer, closer to the plate surface on which the Low-E film 23 is formed, and the total optical thickness of the first antireflection layer is preferably 20 nm or more and 120 nm or less. The Low-E film 23 preferably has a second antireflection layer on the outer side of the metal layer, farther from the plate surface on which the Low-E film 23 is formed, and the total optical thickness of the second antireflection layer is preferably 60 nm or more and 120 nm or less. The optical thickness can be calculated by (refractive index n) x (film thickness d). When the first antireflection layer (second antireflection layer) is composed of multiple films, the sum of the optical thicknesses calculated for each film is the optical thickness of the first antireflection layer (second antireflection layer). When calculating the optical thickness, the refractive index varies depending on the wavelength of visible light. Here, the optical thickness is calculated based on the refractive index when the wavelength of visible light is a common reference wavelength (550 nm) in the visible range.

[0042] As described above, the Low-E film 23 has a first antireflection layer of a predetermined thickness located on the side of the metal layer closer to the second surface 12 of the first glass plate 1, thereby protecting the metal layer and providing the Low-E film 23 with low reflectivity, thereby reliably blocking heat. Furthermore, the glass body 100 can achieve high visible light transmittance and a favorable reflected color tone.

[0043] Furthermore, even if a second antireflection layer of a predetermined thickness is present on the side of the first glass plate 1 farther from the second surface 12 relative to the metal layer, the Low-E film 23 protects the metal layer, allowing the Low-E film 23 to have low reflection performance and reliably block heat. Furthermore, the glass body 100 can achieve high visible light transmittance and a favorable reflection color tone.

[0044] <Radio wave transmission area> In this embodiment, as shown in FIGS. 1 and 2, a plurality of radio wave transmission regions 21 are disposed in the center of the second surface 12 of the first glass plate 1. The plurality of radio wave transmission regions 21 are disposed on the top, bottom, left, and right sides of the second surface 12. Each of the plurality of radio wave transmission regions 21 has a common symmetrical shape and is configured to transmit only radio waves having a predetermined frequency band (e.g., any frequency band selected from the frequency band of 700 MHz to 30 GHz, such as 4G or 5G). As shown in FIG. 2, in this embodiment, each radio wave transmission region 21 is formed in an annular shape, and the Low-E film 23 remains in an inner region 31 located inside the annular radio wave transmission region 21. Because each of the radio wave transmission regions 21 has a common symmetrical shape, the radio wave passing portion 24 can easily maintain frequency selectivity of the transmitted radio waves. This allows the formation of a radio wave transmission region 21 that is optimal for radio waves having a predetermined frequency band. Furthermore, if the radio wave transmission region 21 is annular, radio wave transmission is improved for radio waves having a desired frequency band (for example, any value selected from 3 GHz to 5 GHz), and it is possible to construct a glass body 100 with frequency selectivity that transmits only the desired frequency band. If such a frequency-selective glass body 100 is provided on a windowpane in a highly airtight room, it will not transmit radio waves other than those in the specific frequency band, thereby preventing the leakage of confidential information.

[0045] As shown in FIG. 2, the annular radio wave transmitting region 21 is formed with a patterned section 26 having a plurality of spaced-apart radio wave transmitting sections 24 that allow radio waves to pass through, and a conductive film section 25 in which a Low-E film 23 is formed between adjacent radio wave transmitting sections 24. In the patterned section 26, the radio wave transmitting sections 24 are formed of a plurality of thin wires 24a. The thin wires 24a are formed between adjacent conductive film sections 25, for example, by forming the Low-E film 23 on a glass plate by sputtering and then removing only the Low-E film 23 by laser processing or the like. Forming the thin wires 24a in this manner prevents scratches on the glass plate and makes the thin wires 24a less noticeable.

[0046] The multiple radio wave transmission regions 21 are arranged within square-shaped unit sections 30a each having vertical sides a1, a2 and horizontal sides b1, b2. The unit sections 30a include conductive film regions 22 on the outside and inside (inner regions 31) of the radio wave transmission regions 21. That is, the radio wave transmission regions 21 are provided in a portion of the unit sections 30a, and the conductive film regions 22 are entirely covered around the radio wave transmission regions 21 with a low-E film 23 that blocks radio waves. The length W1 of one side (sides a1, a2, b1, b2) of each unit section 30a is 1 mm or more and 40 mm or less, preferably 3 mm or more and 15 mm or less. The outer diameter W2 of each unit section 30a is less than the side length W1, and is set to 0.5 mm or more and 30 mm or less, preferably 1 mm or more and 10 mm or less. The outer diameter W2 corresponds to the maximum length of the line segment passing through the center of the radio wave transmitting region 21. If this outer diameter W2 is smaller than 0.5 mm, the radio wave transmittance decreases, and if it is larger than 30 mm, the performance of the Low-E film 23 is likely to decrease. The line width W3 of the curved portion including both the radio wave transmitting portion 24 and the conductive film portion 25 is 2 mm or more and 5 mm or less.

[0047] The shortest distance between adjacent radio wave transmitting regions 21 in two unit sections 30a is twice the gap W4 between a side (for example, vertical side a2) of the unit section 30a and the outer edge of the radio wave transmitting region 21. The gap W4 is 0.25 mm to 5 mm, preferably 0.5 mm to 3 mm, and the shortest distance (W4 × 2) is set to 0.5 mm to 10 mm, preferably 1 mm to 6 mm. If the width (W4 × 2) of the conductive film region 22, which is the shortest distance between adjacent radio wave transparent regions 21, is smaller than 0.5 mm, the performance of the Low-E film 23 will decrease. If it is larger than 10 mm, the radio wave transmittance will likely decrease. The multiple radio wave transparent regions 21 are evenly distributed in the partitioned region 30. That is, in the partitioned region 30, the shortest distance (gap W4 × 2) between adjacent radio wave transparent regions 21 is uniform. By making the widths of the conductive film regions 22 (Low-E film 23), which are the shortest distance between adjacent multiple radio wave transparent regions 21, uniform, it is possible to appropriately achieve both the performance of the Low-E film 23 and radio wave transmittance.

[0048] The line width W5 of the thin wires 24a constituting the radio wave passing portion 24 is preferably 1 μm or more and 100 μm or less, and more preferably 5 μm or more and 30 μm or less. If the line width W5 of the thin wires 24a is smaller than 1 μm, the radio wave transmittance decreases, and if it is larger than 100 μm, the performance (heat insulating property or blocking property) of the Low-E film 23 is likely to decrease and the thin wires 24a are likely to be visible.

[0049] The interval (pitch) W6 between adjacent thin wires 24a in one radio wave transmitting region 21 is preferably 200 μm or more and 3 mm or less, and more preferably 500 μm or more and 1 mm or less. If the interval W6 between adjacent thin wires 24a is smaller than 200 μm, the performance (heat insulating property or blocking property) of the Low-E film 23 is likely to decrease and the thin wires 24a are likely to be visible, whereas if it is larger than 3 mm, radio wave transmittance is likely to decrease.

[0050] In this way, the glass body 100 has conductive film regions 22 formed of Low-E film 23 on the second surface 12 of the first glass plate 1, and further has conductive film portions 25 made of Low-E film 23 also provided in the radio wave transparent regions 21, thereby maintaining high performance provided by the Low-E film 23, and improving radio wave transmittance by providing multiple radio wave passing portions 24 in each of the multiple radio wave transparent regions 21. In this way, the glass body 100 has radio wave transparent regions 21 that are not noticeable from the outside, and is able to maintain high performance provided by the Low-E film 23.

[0051] Furthermore, the radio wave transmitting region 21 is formed with a patterned portion 26 having a plurality of radio wave transmitting portions 24 and a conductive film portion 25 between adjacent radio wave transmitting portions 24. That is, the radio wave transmitting region 21 has a mixture of portions (radio wave transmitting portions 24) that do not have the Low-E film 23 (conductive film) and portions (conductive film portions 25) that are covered with the Low-E film 23, in a predetermined pattern. This reduces the impact on appearance between the conductive film region 22 and the radio wave transmitting region 21. As a result, the glass body 100 has a good appearance because the radio wave transmitting region 21 is less noticeable in appearance. Furthermore, frequency selectivity can be imparted by setting the shape of the patterned portion 26.

[0052] In this embodiment, the radio wave transmission region 21 is annular, and the multiple thin wires 24a are formed concentrically along the outer shape of the radio wave transmission region 21. A circular radio wave transmission region 21 provides good radio wave transmission for radio waves in a desired frequency band, resulting in a glass body 100 with frequency selectivity that transmits only the desired frequency band. The multiple thin wires 24a may be formed in the radio wave transmission region 21 in either the left-right direction (along the horizontal sides b1 and b2 of the cell) or the up-down direction (along the vertical sides a1 and a2 of the cell), or may be formed at predetermined intervals. Furthermore, when multiple thin wires 24a are formed in both the left-right direction and the up-down direction, the individual thin wires 24a may be perpendicular to each other. Forming the multiple thin wires 24a parallel to the outer shape of the radio wave transmission region 21 or concentrically facilitates patterning in the radio wave transmission region 21, resulting in good radio wave transmission in a predetermined frequency band.

[0053] The visible light transmittance of the radio wave transparent region 21 is preferably set to be, for example, 1.1 times or less than the visible light transmittance of the conductive film region 22. When the visible light transmittance of the radio wave transparent region 21 is 1.1 times or less than the visible light transmittance of the conductive film region 22, it is possible to reliably reduce the influence on the appearance of the glass body 100 between the conductive film region 22 and the radio wave transparent region 21.

[0054] <Evaluation test> (Test conditions) The first glass plate 1 was made of soda lime glass with a surface of 50 cm × 50 cm and a thickness of 6 mm, and the Low-E film 23 covering the second surface 12 was made of SnO2 / ZnO / Ag / SUS / ZnO / SnO2 from the second surface 12 side of the first glass plate 1, with a total film thickness of 80 nm and an emissivity of 0.1. The laser processing conditions for removing the Low-E film 23 were a YAG:Nd laser with a repetition rate of 100 kHz, a wavelength of 355 nm, and an operation speed of 300 mm / sec, so as to remove only the Low-E film 23 without removing the glass.

[0055] In Example 1, a circular radio wave transmission region 21 shown in FIG. 2 was formed on the entire second surface 12 of the first glass plate 1. The radio wave transmission region 21 in Example 1 had an outer diameter W2 of 22.5 mm, a width W3 of the circular portion of 3 mm, a width W5 of the thin wires 24a of 10 μm, and a spacing W6 (pitch) between adjacent thin wires 24a of 500 μm. In the comparative example, as shown in FIG. 4, the Low-E film 23 was completely removed from the radio wave transmission region 21A. That is, the radio wave transmission region 21A of the comparative example has the same external shape as the radio wave transmission region 21 of Example 1, but differs in configuration from Example 1 in that it does not have a conductive film portion 25 (Low-E film 23). The configuration of the comparative example is the same as that of Example 1 except for the radio wave transmission region 21A.

[0056] Table 1 below shows the outer diameter W2, inner diameter, gap (W4 × 2) between adjacent radio wave transmitting regions 21 (21A), line width (Example 1: W5, Comparative Example: W3), number of lines, spacing (pitch) W6 between the fine lines 24a, and remaining rate of the conductive film (Low-E film 23) on the second surface 12 of the first glass plate 1 in Example 1 and the Comparative Example. [Table 1]

[0057] (exterior) The glass bodies of Example 1 and the Comparative Example were placed on black felt, and the second surfaces 12 of the glass bodies of Example 1 and the Comparative Example were photographed with a camera. FIG. 5 shows the photographed images of Example 1 and the Comparative Example. As shown in FIG. 5, in the Comparative Example, the difference between the color tone of the radio wave transmission region 21A and the color tone of the conductive film region 22 was large, so the shape of the radio wave transmission region 21A was easily visible and gave the impression of being conspicuous. This is thought to be because, in the Comparative Example, the line width W3 of the radio wave transmission region 21A was wide, and the area from which the Low-E film 23 was removed was large (i.e., the remaining rate of the Low-E film 23 was small). On the other hand, in the Example, the radio wave transmission region 21A had a color tone similar to that of the adjacent conductive film region 22, so the shape was barely visible and gave the impression of being difficult to notice. This is thought to be because, in the Example, the line width W5 of the thin wires 24a was narrow, and the area from which the Low-E film 23 was removed was small (i.e., the remaining rate of the Low-E film 23 was large). In addition, the visible light transmittance (average) of the radio wave transmitting region 21A in the comparative example was 1.53 times that of the conductive film region 22, and the visible light transmittance (average) of the radio wave transmitting region 21 in Example 1 was 1.01 times that of the conductive film region 22.

[0058] (Radio wave transparency) The radio wave transmission characteristics of Example 1 and the Comparative Example were evaluated based on the propagation loss (attenuation) (dB) relative to a glass plate (reference glass plate) not having the Low-E film 23. That is, the propagation loss (attenuation) of the glass plate not having the Low-E film 23 was set to 0 dB, and the propagation loss (attenuation) (dB) of the glass body of Example 1 and the Comparative Example was measured under the following conditions. The frequency band of the radio wave for measuring the propagation loss (attenuation) (dB) was 0.7 to 8.5 GHz. The installation angle of the first glass plate 1 was perpendicular (90 degrees) to the ground. The distance between the first glass plate 1 and the transmitting antenna and the distance between the first glass plate 1 and the receiving antenna were both 50 mm. The evaluation results of the radio wave transmission characteristics (propagation loss) versus radio wave frequency are shown in the graph of FIG. 6.

[0059] As shown in the graph of FIG. 6, although the remaining rate of the conductive film (Low-E film 23) differs greatly between the comparative example and Example 1, the difference in propagation loss (attenuation) (dB) is small. Incidentally, when the frequency of the radio wave is 3 GHz, the attenuation amount in the comparative example is −2.3 (dB), and the attenuation amount in the first embodiment is −3.6 dB, so the attenuation rate in the first embodiment is greater than that in the comparative example. On the other hand, when the radio wave frequency is 7 GHz, the attenuation amount in the comparative example is −16.1 (dB) and in example 1 is −14.5 (dB), so that the attenuation amount in example 1 is smaller than that in the comparative example.

[0060] Thus, it was confirmed that Example 1, like the Comparative Example, has sufficient radio wave transmission characteristics, and there is no significant difference in the radio wave frequency selection characteristics between the Comparative Example and Example 1. Therefore, by forming the radio wave transmission region 21 into a thin line pattern as in Example 1, it is possible to form a radio wave transmission region 21 in the glass body 100 that has radio wave frequency selectivity with greatly improved appearance, without significantly impairing the radio wave frequency selection characteristics.

[0061] In addition to Example 1, Examples 2 and 3 were prepared in which the outer diameter W2 of the radio wave transmitting region 21 of Example 1 was increased or decreased, and simulation software (DiffractMOD) was used to calculate the attenuation of radio waves in a predetermined frequency range for Examples 1 to 3. In Example 2, the outer diameter W2 of the radio wave transmitting region 21 was 22.0 mm, 0.5 mm smaller than in Example 1. In Example 3, the outer diameter W2 of the radio wave transmitting region 21 was 23.0 mm, 0.5 mm larger than in Example 1. Other configurations of Examples 2 and 3 are the same as those of Example 1.

[0062] The evaluation results of the radio wave transmission characteristics (propagation loss) of Examples 1, 2, and 3 are shown in the graph of Figure 7. For Examples 1, 2, and 3, the propagation loss was the same up to the frequency band of 5 GHz, but for radio waves with frequencies of 5 to 8 GHz, attenuation calculations showed that Example 2, which has the smallest outer diameter W2, had the smallest propagation loss. From this, it can be seen that as long as the outer diameter W2 of the radio wave transmission region 21 is in the range of 22 mm to 23 mm, there is no difference in radio wave transmission property for any frequency band selected from 3 GHz to 5 GHz.

[0063] <Second embodiment: double glazing> As shown in FIGS. 8 and 9 , the glass body 100 of the second embodiment is a double-glazed glass panel having two glass sheets, i.e., a first glass sheet 1 and a second glass sheet 2, whose sheet surfaces have substantially the same rectangular outer shape. The pair of glass sheets 1 and 2 are connected to each other by a spacer 5 arranged around their peripheries. The spacer 5 forms an air gap layer 3 between the pair of glass sheets 1 and 2. The first glass sheet 1 has a first surface 11, which is the sheet surface facing the outdoor side, and a second surface 12, which is the sheet surface facing the air gap layer 3 opposite the first surface 11. The second glass sheet 2 has a third surface 13, which is the sheet surface facing the air gap layer 3, and a fourth surface 14, which is the sheet surface facing the indoor side opposite the third surface 13. In other words, the spacer 5 is in contact with the second surface 12 and the third surface 13. A Low-E film 23 (an example of a conductive film) having radio wave blocking properties is formed on the sheet surface (second surface 12) facing the air gap layer 3. Although not shown, the air gap layer 3 is sealed by a frame on which a sealing material is arranged and which is disposed outside the spacers 5.

[0064] The second surface 12 of the first glass sheet 1 has a conductive film region 22 in which a Low-E film 23 is formed over the entire surface. Furthermore, the second surface 12, which is the plate surface on which the Low-E film 23 is formed, has a radio wave-transmitting region 21 formed by removing a portion of the Low-E film 23 using laser processing or the like. This radio wave-transmitting region 21 is positioned to allow transmission of radio waves corresponding to a frequency band of 700 MHz to 30 GHz (wavelength 428 mm to 10 mm), such as 4G and 5G, which have linear propagation. Note that in a double-glazed glass such as this embodiment, providing the Low-E film 23 on the second surface 12 of the first glass sheet 1 or the third surface 13 of the second glass sheet 2 improves thermal insulation performance. The conductive film region 22 and the radio wave-transmitting region 21 may also be provided on the first surface 11 of the first glass sheet 1 or the fourth surface 14 of the second glass sheet 2. Furthermore, an antenna (not shown) for transmitting and receiving radio waves may be installed on the indoor-facing plate surface (fourth surface 14) of the glass body 100, or the antenna may be installed on the indoor ceiling or the like.

[0065] [Other embodiments] (1) In the above embodiment, an example was shown in which the radio wave transparent region 21 had a circular ring shape, but the shape of the radio wave transparent region 21 is not limited to a circular ring shape and may be any of the shapes shown in (a) to (j) in Fig. 10. Like the radio wave transparent region 21 shown in Fig. 2, the radio wave transparent regions 21 shown in (a) to (j) in Fig. 10 also have a shape formed with a constant line width, and are formed with a patterned portion 26 having a plurality of thin wires 24a and a conductive film portion 25. Furthermore, the plurality of thin wires 24a may be formed in both the left-right direction and the up-down direction.

[0066] Among the shapes of the radio wave transparent region 21 shown in FIG. 10, (a) [Three-legged] and (b) [Anchor] are common in that the radio wave transparent region 21 includes three lines extending from the center to each vertex of a triangle. (c) [Cross], (d) [Jerusalem cross], and (e) [Square spiral] are common in that the radio wave transparent region 21 includes a crosshair. (f) [Three-legged loaded], (g) [Four-legged loaded], (h) [Square loop], (i) [Hexagonal loop], and (j) [Mixed (d) and (g)] are common in that the radio wave transparent region 21 is annular. When the radio wave transparent region 21 has a linear outer shape, the multiple thin wires 24a can be formed parallel to the outer shape of the radio wave transparent region 21. The radio wave transparent region 21 shown in FIG. 10 also has high radio wave transparency for specific frequency bands and frequency selectivity that allows only specific frequency bands to pass through.

[0067] (2) In the radio wave transmitting region 21, it is not necessary to remove the Low-E film 23 to expose the glass plate, as long as at least the metal layer containing silver as the main component is removed.

[0068] (3) In the double-glazing glass of the second embodiment, a heat-shielding film may be disposed on the second surface 12 of the first glass sheet 1, and a Low-E film 23 may be disposed on the third surface 13 of the second glass sheet 2. The heat-shielding film is preferably a multilayer film including a layer containing titanium nitride as a main component. A suitable example of a metal nitride layer is a titanium nitride layer. The thickness of the heat-shielding film is selected appropriately depending on the type of film to be laminated, but is usually 5 to 100 nm, and preferably 10 to 50 nm. The heat-shielding film is composed of, for example, a heat-ray absorbing film. When the heat-shielding film is a heat-ray absorbing film, infrared rays can be absorbed by the heat-shielding film, thereby improving the heat-shielding properties of the glass body 100. [Industrial Applicability]

[0069] The present invention can be used as a glass body for window glass of buildings, and window glass of moving bodies such as automobiles, aircraft, ships, and trains. [Explanation of symbols]

[0070] 1: First glass plate 2: Second glass plate 3 :Void layer 5: Spacer 11: 1st page 12:Second side 13:Third side 14:Side 4 21:Radio wave transmission area 22: Conductive film area 23: Low-E film (conductive film) 24:Radio wave passing section 24a: Thin line 25: Conductive film section 26: Patterning section 30: Compartment area 30a: Unit plot 100: Glass body W2: Outer diameter W3: Line width W4: Gap W5: Line width

Claims

1. a first glass plate having a first surface and a second surface opposite to the first surface; at least one of the first and second surfaces includes a plurality of radio wave transmission regions that are spaced apart and allow radio waves to pass through, and a conductive film region that is entirely covered around the radio wave transmission regions with a conductive film that has a property of blocking the radio waves, the conductive film is a Low-E film, a patterning section is formed in each of the radio wave transmitting regions, the patterning section having a plurality of radio wave passing sections spaced apart from each other and allowing the radio waves to pass therethrough, and a conductive film section in which the conductive film is formed between adjacent radio wave passing sections; A glass body in which the patterning portion is formed of thin lines having a line width of 5 μm or more and 30 μm or less, the radio wave passing portion has a width of 2 mm or more and 5 mm or less, and the spacing between adjacent thin lines is 500 μm or more and 1 mm or less.

2. 2. The glass body according to claim 1, wherein each of the radio wave transmitting regions has a common symmetrical shape configured to transmit only the radio waves having a predetermined frequency band.

3. 3. The glass body according to claim 1, wherein the width of the conductive film region, which is the shortest distance between adjacent radio wave transmitting regions, is uniform.

4. 4. The glass body according to claim 3, wherein the width of the conductive film region, which is the shortest distance between adjacent radio wave transmitting regions, is 0.5 mm or more and 10 mm or less.

5. The glass body according to claim 1 , wherein the maximum length of a line segment passing through the center of the radio wave transmitting region is 0.5 mm or more and 30 mm or less.

6. The glass body according to claim 5 , wherein the plurality of thin wires are formed parallel to or concentric with the outline of the radio wave transmitting region.

7. The glass body according to claim 1 , wherein the radio wave transmitting region is annular.

8. 8. The glass body according to claim 1, wherein the visible light transmittance of the radio wave transmitting region is set to be 1.1 times or less the visible light transmittance of the conductive film region.

9. a second glass plate having a third surface opposite to the second surface and a fourth surface opposite to the third surface; a spacer in contact with the second surface and the third surface to form a gap layer between the first glass plate and the second glass plate, The glass body according to claim 1 , wherein the radio wave transmitting region is formed on the second surface or the third surface.

Images