Multi-layered glass

Abstract

Provided is a technique for suppressing warpage of vacuum glass caused by the high thermal insulation properties of vacuum glass.　This multi-layered glass comprises, in the stated order in a prescribed direction: a vacuum glass having a first glass plate, a vacuum layer, and a second glass plate in the stated order in the prescribed direction; a gas layer; and a third glass plate or laminated glass. The thickness of the third glass plate or the laminated glass is greater than the thickness of the vacuum glass.

Description

double-glazed glass

[0001] The present disclosure relates to insulating glazing.

[0002] Double-glazed glass incorporating vacuum glass is known. Vacuum glass has a first glass pane, a vacuum layer, and a second glass pane arranged in this order in a specific direction. The vacuum layer suppresses heat conduction and convection, among the three principles of heat transfer (radiation, conduction, and convection), and provides high thermal insulation.

[0003] The double glazing described in Patent Document 1 below comprises a vacuum glass pane and a regular glass pane spaced apart. Dry air or a rare gas is sealed between the vacuum glass pane and the regular glass pane. According to Table 1 of Patent Document 1, the vacuum glass pane and the regular glass pane have the same thickness.

[0004] Japanese Patent Application Publication No. 10-87350

[0005] Vacuum glass has high thermal insulation properties and can experience large temperature differences in a certain direction. This temperature difference can cause dimensional differences between the first and second glass panes. As a result, the vacuum glass can warp. When the vacuum glass warps, the first and second glass panes warp to the same degree in the same direction.

[0006] One aspect of the present disclosure provides a technique for suppressing warping of vacuum glass that is caused by the high thermal insulation properties of vacuum glass incorporated into double glazing.

[0007] A double-glazing unit according to one aspect of the present disclosure includes a vacuum glazing unit having a first glass sheet, a vacuum layer, and a second glass sheet, arranged in this order in a predetermined direction, a gas layer, and a third glass sheet or laminated glass, arranged in this order in the predetermined direction, wherein the thickness of the third glass sheet or laminated glass is greater than the thickness of the vacuum glazing unit.

[0008] According to one aspect of the present disclosure, the thickness of the third glass sheet or laminated glass is greater than the thickness of the vacuum glass, and therefore, by utilizing the thermal expansion or thermal contraction of the gas layer formed between the third glass sheet or laminated glass and the vacuum glass, warping of the vacuum glass due to the high thermal insulation properties of the vacuum glass can be suppressed.

[0009] FIG. 1 is a cross-sectional view of a double-glazing unit according to an embodiment. FIG. 2 is a cross-sectional view showing an enlarged portion of the double-glazing unit shown in FIG. 1. FIG. 3A is a cross-sectional view showing a state in which the temperature increases toward a predetermined direction (leftward in the figure) in a double-glazing unit according to a conventional example, and FIG. 3B is a cross-sectional view showing a state in which the temperature increases toward a predetermined direction (leftward in the figure) in a double-glazing unit according to an example. FIG. 4A is a cross-sectional view showing a state in which the temperature decreases toward a predetermined direction (leftward in the figure) in a double-glazing unit according to a conventional example, and FIG. 4B is a cross-sectional view showing a state in which the temperature decreases toward a predetermined direction (leftward in the figure) in a double-glazing unit according to an example. FIG. 5 is a cross-sectional view showing an example of a low-emissivity film. FIG. 6 is a cross-sectional view showing an example of a double-glazing unit including laminated glass instead of a third glass sheet. FIG. 7 is a cross-sectional view showing an example in which a low-reflection film is provided on the double-glazing unit shown in FIG. 6.

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In each drawing, the same or corresponding components are denoted by the same reference numerals, and their description may be omitted. In the specification, the term "to" indicating a range of values ​​means that the values ​​before and after it are included as the lower and upper limits.

[0011] A double-glazing unit 2 according to one embodiment will be described with reference to Figures 1 and 2. The double-glazing unit 2 is used, for example, as window glass in a building. In this embodiment, the double-glazing unit 2 is installed vertically, but it may also be installed at an angle or horizontally. In this embodiment, the shape of the double-glazing unit 2 when viewed from inside or outside the room is rectangular, but it may also be circular, semicircular, trapezoidal, triangular, or other shapes, and is not particularly limited. The corners of shapes with corners, such as rectangular, trapezoidal, or triangular, may be chamfered.

[0012] When the double-glazing glass 2 has a rectangular shape when viewed from the inside or outside of the room, the length of the shortest side of the rectangle is preferably 600 mm or more, and more preferably 1000 mm or more. Generally, the larger the size of the double-glazing glass 2, the more likely it is that warping will occur. The larger the size of the double-glazing glass 2, the more likely it is that the technology disclosed herein will be effective in suppressing warping.

[0013] The double glazing 2 includes a vacuum glass 10, a gas layer 20, and a third glass sheet 30, arranged in this order in a predetermined direction (leftward in Figures 1 and 2). In this specification, the predetermined direction is the direction along the thickness direction. In this embodiment, the predetermined direction is the direction from inside the room to outside the room, but it may also be the direction from outside to inside the room.

[0014] The vacuum glass 10 has a first glass plate 11, a vacuum layer 12, and a second glass plate 13 arranged in this order in a predetermined direction. The pressure in the vacuum layer 12 is preferably 1×10 －５ Pa to 10 Pa, more preferably 1×10 －５ The pressure is 0.1 Pa to 0.1 Pa. Of the three principles of heat transfer (radiation, conduction, and convection), the vacuum layer 12 suppresses heat conduction and convection, and exhibits high heat insulation properties.

[0015] As will be described in more detail below, to suppress the remaining radiation of the three principles of heat transfer, a low-emissivity film 40 may be provided as shown in Fig. 5. The low-emissivity film 40 is provided on at least one of the mutually opposing first and second surfaces 41 and 42 of the first and second glass plates 11 and 13, and the mutually opposing third and fourth surfaces 43 and 44 of the vacuum glass 10 and third glass plate 30, so as to prevent exposure to the atmosphere.

[0016] The vacuum glass 10 has high thermal insulation properties and may experience a large temperature difference in a predetermined direction. The outdoor temperature may be higher than the indoor temperature, or the indoor temperature may be higher than the outdoor temperature. In this embodiment, the vacuum glass 10 is provided on the indoor side of the third glass sheet 30, but it may also be provided on the outdoor side of the third glass sheet 30.

[0017] The first glass plate 11 and the second glass plate 13 are formed of glass commonly used in buildings. Examples of the glass include soda-lime glass, aluminosilicate glass, borosilicate glass, and alkali-free glass. The glass may be either untempered glass or tempered glass. The tempered glass may be either air-cooled tempered glass or chemically tempered glass. The glass may also be crystallized glass.

[0018] The thicknesses of the first glass plate 11 and the second glass plate 13 may be the same or different. The difference in thickness between the first glass plate 11 and the second glass plate 13 can prevent the first glass plate 11 and the second glass plate 13 from cracking due to a temperature difference. When the thicknesses of the first glass plate 11 and the second glass plate 13 are different, the thickness of the first glass plate 11 may be 1 mm or more thicker, 2 mm or more thicker, or 3 mm or more thicker than the thickness of the second glass plate 13. Within the above range, cracking due to a temperature difference between the first glass plate 11 and the second glass plate 13 when the third glass plate 30 is at a lower temperature than the first glass plate 11 can be prevented. Furthermore, when the thicknesses of the first glass plate 11 and the second glass plate 13 are different, the thickness 11 of the first glass plate 11 may be 1 mm or less thinner, 2 mm or more thicker, or 3 mm or less thinner than the thickness of the second glass plate 13. Within the above range, when the third glass plate 30 has a higher temperature than the first glass plate 11, the first glass plate 11 and the second glass plate 13 can be prevented from cracking due to the temperature difference.

[0019] The vacuum layer 12 is formed between the first glass plate 11 and the second glass plate 13. The thickness of the vacuum layer 12 is preferably 0.05 mm or more, and more preferably 0.07 mm or more. If the thickness of the vacuum layer 12 is 0.05 mm or more, high heat insulation properties can be obtained. The thickness of the vacuum layer 12 is preferably 0.2 mm or less, more preferably 0.15 mm or less, and even more preferably 0.10 mm or less. If the thickness of the vacuum layer 12 is 0.2 mm or less, the first glass plate 11 and the second glass plate 13 are less likely to warp, and deterioration of appearance due to reflected light from the first glass plate 11 and the second glass plate 13 is less likely to occur.

[0020] Pillars (not shown) may be provided between the first glass plate 11 and the second glass plate 13 so that the thickness of the vacuum layer 12 is constant. When pillars are provided, a plurality of pillars are arranged two-dimensionally. The thickness of the pillars is equal to the thickness of the vacuum layer 12.

[0021] The vacuum glass 10 includes a sealing layer 14. The sealing layer 14 is provided along the periphery of the vacuum glass 10. The sealing layer 14 seals the vacuum layer 12 and bonds the first glass sheet 11 and the second glass sheet 13 together. The sealing layer 14 is preferably a glass layer rather than a resin layer. The glass layer can maintain the pressure of the vacuum layer 12 at a desired pressure for a long period of time.

[0022] The glass layer serving as the sealing layer 14 is formed by filling a glass frit between the first glass plate 11 and the second glass plate 13 and firing the filled glass frit. After forming a glass layer by firing the glass frit at a high temperature in the atmosphere, the vacuum layer 12 may be formed by drawing a vacuum, or the glass layer and the vacuum layer 12 may be formed simultaneously by firing the glass frit at a high temperature in a vacuum.

[0023] The gas layer 20 is formed between the vacuum glass 10 and the third glass plate 30. The gas layer 20 has a lower thermal conductivity than glass, improving thermal insulation. The gas layer 20 is composed of, for example, dry air or a rare gas. Dry air is a gas obtained by removing water vapor from air to prevent condensation. The rare gas is, for example, Ar gas, He gas, or Kr gas. The rare gas has a lower thermal conductivity than dry air, further improving thermal insulation.

[0024] The third glass plate 30 is disposed opposite the second glass plate 13 of the vacuum glass 10. In this embodiment, the third glass plate 30 is disposed on the exterior side of the vacuum glass 10, but may also be disposed on the interior side of the vacuum glass 10. Like the first glass plate 11 and the second glass plate 13, the third glass plate 30 is formed of general glass for buildings. The glass may be, for example, soda-lime glass, aluminosilicate glass, borosilicate glass, or alkali-free glass. The glass may be either untempered glass or tempered glass. The tempered glass may be either air-cooled tempered glass or chemically tempered glass. The glass may also be crystallized glass. The third glass plate 30 may be wired glass or figured glass, or may be laminated glass. When the third glass plate 30 is laminated glass, at least one glass pane of the laminated glass may be tempered glass.

[0025] As shown in Figure 2, the double glazing 2 includes a gas layer 20, a spacer 21, primary seals 22 and 23, and a secondary seal 24 between the vacuum glass 10 and the third glass pane 30. The spacer 21, primary seals 22 and 23, and secondary seal 24 are provided along the periphery of the double glazing 2 to surround the gas layer 20 and restrict atmospheric air from entering the gas layer 20.

[0026] The spacer 21 separates the vacuum glass 10 from the third glass plate 30 and maintains the thickness t2 of the gas layer 20 at a desired thickness.

[0027] The spacer 21 has a storage chamber 21a that stores a desiccant 25 and a communication hole 21b that connects the storage chamber 21a to the gas layer 20. The desiccant 25 is, for example, granular zeolite. The desiccant 25 dries the gas layer 20 by adsorbing water vapor. The spacer 21 is made of, for example, a metal or a resin. The metal is, for example, aluminum or stainless steel.

[0028] The primary seal 22 is provided between the vacuum glass 10 and the spacer 21. The primary seal 23 is provided between the spacer 21 and the third glass sheet 30. The primary seals 22 and 23 are not particularly limited, but may contain, for example, butyl rubber or polyisobutylene as a main component. The primary seals 22 and 23 may further contain a filler such as carbon black for the purposes of coloring and reinforcement.

[0029] The secondary seal 24 is disposed on the opposite side of the spacer 21 from the gas layer 20, and bonds the spacer 21, the vacuum glass 10, and the third glass sheet 30 together. The secondary seal 24 preferably contains a curable elastomer as a main component. Examples of the curable elastomer include polysulfide, silicone, or urethane. The curable elastomer may be appropriately modified to improve adhesion.

[0030] In this embodiment, the spacer 21, the primary seals 22 and 23, and the secondary seal 24 are used, but instead, a sealing material that serves as both a spacer and a seal may be used. The sealing material is made of resin. The sealing material may be a single layer or multiple layers. When the sealing material is a multiple layer, the multiple layers are continuously arranged in a direction perpendicular to the interface between the sealing material and the gas layer 20.

[0031] The double-glazing glass 2 is fitted into a groove 6 in a window frame 5 via, for example, a glazing channel 3. The glazing channel 3 is provided along the periphery of the double-glazing glass 2 and fills the gap between the double-glazing glass 2 and the window frame 5. A setting block 7 may be provided in the groove 6 in the window frame 5. The double-glazing glass 2 is placed on top of the setting block 7.

[0032] 3A, a state in which the temperature increases in a predetermined direction (leftward in the figure) in a conventional double-glazing unit 2 will be described. The right side of the double-glazing unit 2 is the indoor side, and the left side of the double-glazing unit 2 is the outdoor side. For example, in summer, the outdoor temperature is higher than the indoor temperature, and the temperature increases toward the left in the figure.

[0033] The temperature difference in the vacuum glass 10 causes a dimensional difference between the first glass sheet 11 and the second glass sheet 13. Because the sealing layer 14 is thinner and harder than the secondary seal 24, it does not undergo shear deformation that would absorb the dimensional difference between the first glass sheet 11 and the second glass sheet 13. Therefore, when a dimensional difference occurs between the first glass sheet 11 and the second glass sheet 13, the first glass sheet 11 and the second glass sheet 13 warp in the same direction and to the same extent. The warp is, for example, a convex warp toward the outside (left side in FIG. 3A ).

[0034] In the conventional double-glazing glass 2, the thickness t3 of the third glass pane 30 is equal to or less than the thickness t1 of the vacuum glass 10. That is, in the conventional double-glazing glass 2, the bending rigidity of the third glass pane 30 is equal to or less than the bending rigidity of the vacuum glass 10 in a side view. Therefore, the third glass pane 30 is prone to bending.

[0035] When the vacuum glass 10 warps, it presses against the third glass sheet 30 via the gas layer 20. The third glass sheet 30 is easily bent and warps more in the same direction as the vacuum glass 10 than the vacuum glass 10. The reason why the third glass sheet 30 warps more is that in summer, the temperature of the gas layer 20 is higher than the temperature of the gas layer 20 during the manufacture of the double-glazed glass 2, causing thermal expansion of the gas layer 20. The thermal expansion of the gas layer 20 promotes warping of the third glass sheet 30.

[0036] Note that a temperature difference may occur between the vacuum glass 10 and the third glass plate 30, resulting in a dimensional difference. However, the secondary seal 24 is made of rubber or the like and is capable of shear deformation to absorb the dimensional difference between the vacuum glass 10 and the third glass plate 30. Therefore, warping due to the dimensional difference between the vacuum glass 10 and the third glass plate 30 hardly occurs.

[0037] 3B , a state in which the temperature increases in a predetermined direction (toward the left in the figure) in the double-glazing glass 2 according to the example will be described. In the double-glazing glass 2 according to the example, the thickness t3 of the third glass pane 30 is greater than the thickness t1 of the vacuum glass pane 10. That is, in the double-glazing glass 2 according to the example, the bending rigidity of the third glass pane 30 is greater than the bending rigidity of the vacuum glass pane 10 in a side view.

[0038] According to the embodiment, the third glass plate 30 hardly bends. Therefore, even if the vacuum glass 10 tries to warp so as to protrude to the left, the third glass plate 30 pushes the vacuum glass 10 back to the right via the gas layer 20. The thermal expansion of the gas layer 20 also acts to push the vacuum glass 10 back to the right. Therefore, warping of the vacuum glass 10 can be suppressed.

[0039] The thickness t2 of the gas layer 20 is preferably greater than the thickness of the vacuum layer 12. The thickness t2 of the gas layer 20 is preferably 3 mm or more, and more preferably 5 mm or more. If t2 is 3 mm or more, the thermal expansion force of the gas layer 20 is sufficiently large. Note that if t2 is 3 mm or more, the thermal contraction force of the gas layer 20, which will be described later, is also sufficiently large. Furthermore, the thickness t2 of the gas layer 20 is preferably 20 mm or less, and more preferably 15 mm or less. If t2 is 20 mm or less, convection can be suppressed.

[0040] 4A , a state in which the temperature decreases toward a specific direction (leftward in the figure) in a conventional double-glazing unit 2 will be described. The right side of the double-glazing unit 2 is the indoor side, and the left side of the double-glazing unit 2 is the outdoor side. For example, in winter, the outdoor temperature is lower than the indoor temperature, and the temperature decreases toward the left in the figure.

[0041] The temperature difference in the vacuum glass 10 causes a dimensional difference between the first glass sheet 11 and the second glass sheet 13. Because the sealing layer 14 is thinner and harder than the secondary seal 24, it hardly generates shear deformation that would absorb the dimensional difference between the first glass sheet 11 and the second glass sheet 13. Therefore, when a dimensional difference occurs between the first glass sheet 11 and the second glass sheet 13, the first glass sheet 11 and the second glass sheet 13 warp in the same direction and to the same extent. The warp is, for example, a convex warp toward the interior side (the right side in FIG. 4A ).

[0042] In the conventional double-glazing glass 2, the thickness t3 of the third glass pane 30 is equal to or less than the thickness t1 of the vacuum glass 10. That is, in the conventional double-glazing glass 2, the bending rigidity of the third glass pane 30 is equal to or less than the bending rigidity of the vacuum glass 10 in a side view. Therefore, the third glass pane 30 is prone to bending.

[0043] When the vacuum glass 10 warps, it attracts the third glass sheet 30 via the gas layer 20. The third glass sheet 30 is easily bent and warps more in the same direction as the vacuum glass 10 than the vacuum glass 10. The reason why the third glass sheet 30 warps more is that in winter, the temperature of the gas layer 20 is lower than the temperature of the gas layer 20 during the manufacture of the double-glazed glass 2, causing thermal contraction of the gas layer 20. The thermal contraction of the gas layer 20 promotes warping of the third glass sheet 30.

[0044] 4B , a state in which the temperature decreases toward a predetermined direction (leftward in the figure) in the double-glazing glass 2 according to the example will be described. In the double-glazing glass 2 according to the example, the thickness t3 of the third glass pane 30 is greater than the thickness t1 of the vacuum glass pane 10. That is, in the double-glazing glass 2 according to the example, the bending rigidity of the third glass pane 30 is greater than the bending rigidity of the vacuum glass pane 10 in a side view.

[0045] According to the embodiment, the third glass sheet 30 hardly bends. Therefore, even if the vacuum glass sheet 10 tries to warp so as to protrude to the right, the third glass sheet 30 pulls the vacuum glass sheet 10 back to the left via the gas layer 20. The thermal contraction of the gas layer 20 also acts to pull the vacuum glass sheet 10 back to the left. Therefore, warping of the vacuum glass sheet 10 can be suppressed.

[0046] The difference (t3 - t1) between the thickness t3 of the third glass sheet 30 and the thickness t1 of the vacuum glass 10 is preferably 0.5 mm or more, more preferably 1.0 mm or more, and even more preferably 2.0 mm or more. If the difference (t3 - t1) is 0.5 mm or more, the difference in bending rigidity is sufficiently large. From the viewpoint of thinning the double glazing 2, the difference (t3 - t1) is, for example, 3.0 mm or less.

[0047] At least one of the first glass plate 11 and the second glass plate 13 may be tempered glass. Tempered glass has superior strength (less likely to break) and can be made thinner than untempered glass. This allows the vacuum glass 10 to be made thinner, and the difference in bending rigidity between the vacuum glass 10 and the third glass plate 30 can be increased. The thickness of the tempered glass is preferably 0.5 mm to 2.0 mm, and more preferably 1.0 mm to 2.0 mm.

[0048] The tempered glass may be either air-tempered or chemically tempered. However, the tempered glass is preferably chemically tempered. Unlike air-tempered glass, chemically tempered glass can be manufactured without creating a temperature difference, and is therefore more suitable for thinning than air-tempered glass.

[0049] Air-cooling tempering involves rapidly cooling a uniformly heated glass sheet from a temperature near its softening point, creating compressive stress on the surface due to the temperature difference between the surface and interior of the glass.Chemical tempering involves replacing alkali metal ions on the surface of the glass with other alkali metal ions with a larger ionic radius, creating compressive stress on the surface of the glass.

[0050] The surface compressive stress of the chemically strengthened glass is preferably 340 MPa or more, more preferably 360 MPa or more, and still more preferably 380 MPa or more. From the viewpoint of production costs, the surface compressive stress of the chemically strengthened glass is preferably 650 MPa or less.

[0051] The thickness of the compressive stress layer of the chemically strengthened glass is preferably 20 μm or more, more preferably 24 μm or more, and even more preferably 28 μm or more. From the viewpoint of manufacturing costs, the thickness of the compressive stress layer of the chemically strengthened glass is preferably 50 μm or less.

[0052] As shown in Figure 5, the double glazing 2 may be provided with a low-emissivity film 40 to suppress radiation. The low-emissivity film 40 is also called a Low-E (Low Emissivity) film. When the double glazing 2 is provided with the low-emissivity film 40, the thermal insulation properties of the double glazing 2 are further improved, making it very meaningful to apply the present invention.

[0053] The low-emissivity film 40 includes, for example, a heat-reflecting layer. The heat-reflecting layer is made of silver (Ag) or tin oxide (SnO ２ The low-emissivity film 40 may include multiple layers, and may include a heat-reflecting layer and a dielectric layer. The dielectric layer is made of an oxide, nitride, or oxynitride. The low-emissivity film 40 is formed by chemical vapor deposition, sputtering, or the like.

[0054] The low-emissivity film 40 is provided on at least one of the mutually opposing first and second surfaces 41 and 42 of the first and second glass plates 11 and 13, and the mutually opposing third and fourth surfaces 43 and 44 of the vacuum glass 10 and third glass plate 30 (fourth surface 44 in FIG. 5 ) so as not to be exposed to the atmosphere. This makes it possible to prevent oxidation of the low-emissivity film 40 due to water vapor in the atmosphere and damage to the low-emissivity film 40 due to dust and sand.

[0055] As shown in Fig. 6, the double glazing 2 may include a laminated glass 50 instead of the third glass pane 30. The laminated glass 50 includes multiple (e.g., two) glass panes 51, 53 and an interlayer film 52 that bonds the two adjacent glass panes 51, 53 together. In this case, it is sufficient that the thickness t4 of the laminated glass 50 is greater than the thickness t1 of the vacuum glass 10.

[0056] The difference (t4 - t1) between the thickness t4 of the laminated glass 50 and the thickness t1 of the vacuum glass 10 is preferably 0.5 mm or more, more preferably 1.0 mm or more, and even more preferably 2.0 mm or more. If the difference (t4 - t1) is 0.5 mm or more, the difference in bending rigidity is sufficiently large. From the viewpoint of thinning the double-glazing unit 2, the difference (t4 - t1) is, for example, 3.0 mm or less.

[0057] Various organic resins that are commonly used in conventional laminated glass can be used for the interlayer film 52. From the viewpoints of transparency and adhesion, examples of organic resins include polyvinyl butyral (PVB) and ethylene vinyl acetate copolymer (EVA).

[0058] 7 , a low-emissivity film 40 may be provided on at least one of the opposing third surfaces 43 and fourth surfaces 44 of the vacuum glass 10 and the laminated glass 50. As described above, the low-emissivity film 40 may be provided on at least one of the opposing first surfaces 41 and second surfaces 42 of the first glass sheet 11 and the second glass sheet 13.

[0059] Experimental data will be described below. Example 1 below is an embodiment, and Example 2 is a comparative example. In Examples 1 and 2, double-glazing units 2 were manufactured under the same conditions except for the thickness t3 of the third glass sheet 30. As shown in FIG. 1 etc., the double-glazing units 2 were composed of a vacuum glass sheet 10, a gas layer 20, and a third glass sheet 30. In Example 1, the thickness t3 of the third glass sheet 30 was 8.0 mm. In Example 2, the thickness t3 of the third glass sheet 30 was 3.0 mm. The shape of the double-glazing units 2 when viewed from inside or outside the room was a square (each side 600 mm).

[0060] In both Example 1 and Example 2, the thickness t1 of the vacuum glass 10 was 6.1 mm, and the thickness t2 of the gas layer 20 was 12 mm. The thickness of the first glass plate 11 was 3.0 mm, the thickness of the second glass plate 13 was 3.0 mm, and the thickness of the vacuum layer 12 was 0.1 mm. The first glass plate 11, the second glass plate 13, and the third glass plate 30 were all untempered glass. The low-emissivity coating 40 was formed only on the second surface 42.

[0061] In Examples 1 and 2, the manufactured double-glazed glass 2 was installed in a window in a chamber, and the temperature inside the chamber was changed between -21°C and 48°C for four cycles over two days. The vacuum glass 10 was installed facing the outside of the chamber. The third glass sheet 30 was installed facing the inside of the chamber. Since the temperature inside the chamber changes, the inside of the chamber corresponds to the outside of the room, and the outside of the chamber corresponds to the inside of the room. The temperature outside the chamber was maintained at 24°C to 25°C. The warpage of the vacuum glass 10 and the warpage of the third glass sheet 30 were then measured. The measurement results are shown in Table 1.

[0062]

[0063] First, we will explain the results of measuring warpage in summer. In summer, as shown in Figures 3A and 3B, the outdoor temperature is higher than the indoor temperature, with the temperature increasing toward the left in the figure. In Example 2, as shown in Figure 3A, the thickness t3 of the third glass sheet 30 was smaller than the thickness t1 of the vacuum glass sheet 10, and the vacuum glass sheet 10 warped convexly toward the outside (left side in Figure 3A), and the third glass sheet 30 warped more than the vacuum glass sheet 10 in the same direction as the vacuum glass sheet 10. On the other hand, in Example 1, as shown in Figure 3B, the thickness t3 of the third glass sheet 30 was larger than the thickness t1 of the vacuum glass sheet 10, and the vacuum glass sheet 10 warped less, and the warpage of the third glass sheet 30 was also small. In Example 1, the third glass sheet 30 hardly bent. Therefore, even if the vacuum glass sheet 10 tried to warp to the left, the third glass sheet 30 pushed the vacuum glass sheet 10 back to the right through the gas layer 20. The thermal expansion of the gas layer 20 also acts to push the vacuum glass 10 back to the right side, thereby suppressing warping of the vacuum glass 10.

[0064] Next, the measurement results of warpage in winter will be described. In winter, as shown in Figures 4A and 4B, the outdoor temperature is lower than the indoor temperature, with the temperature decreasing toward the left in the figure. In Example 2, as shown in Figure 4A, the thickness t3 of the third glass sheet 30 was smaller than the thickness t1 of the vacuum glass sheet 10, and the vacuum glass sheet 10 warped convexly toward the indoor side (the right side in Figure 4A), and the third glass sheet 30 warped more than the vacuum glass sheet 10 in the same direction as the vacuum glass sheet 10. On the other hand, in Example 1, as shown in Figure 4B, the thickness t3 of the third glass sheet 30 was larger than the thickness t1 of the vacuum glass sheet 10, and the vacuum glass sheet 10 warped less, and the warpage of the third glass sheet 30 was also small. In Example 1, the third glass sheet 30 hardly bent. Therefore, even if the vacuum glass sheet 10 tried to warp to the right, the third glass sheet 30 pulled the vacuum glass sheet 10 back to the left through the gas layer 20. The thermal contraction of the gas layer 20 also acts to pull the vacuum glass 10 back to the left, thereby suppressing warping of the vacuum glass 10.

[0065] When the outdoor temperature and the indoor temperature were both 25° C., in both Example 1 and Example 2, the vacuum glass 10 and the third glass plate 30 hardly warped.

[0066] The following supplementary notes are disclosed regarding the above-described embodiments.

[0067] [Supplementary Note 1] Double-glazing comprising: a vacuum glazing having a first glass plate, a vacuum layer, and a second glass plate, in that order, in a predetermined direction; a gas layer; and a third glass plate or laminated glass, in that order, in the predetermined direction; wherein the thickness of the third glass plate or laminated glass is greater than the thickness of the vacuum glazing.

[0068] [Appendix 2] The double-glazing unit according to Appendix 1, wherein the difference between the thickness of the third glass plate or laminated glass and the thickness of the vacuum glass is 0.5 mm or more.

[0069] [Appendix 3] The double-glazing unit according to Appendix 1 or 2, further comprising a low-emissivity coating on at least one of the first and second opposing surfaces of the first and second glass sheets, and the third and fourth opposing surfaces of the third glass sheet or laminated glass and the vacuum glass.

[0070] [Appendix 4] The insulating glass according to any one of Appendices 1 to 3, wherein at least one of the first glass plate and the second glass plate is tempered glass.

[0071] [Appendix 5] The double-glazing unit according to Appendix 4, wherein the tempered glass has a thickness of 0.5 mm to 2.0 mm.

[0072] [Appendix 6] The double-glazing unit according to any one of Appendices 1 to 5, wherein the thickness of the gas layer is 3 mm to 20 mm.

[0073] The above describes the double-glazing glass according to the present disclosure, but the present disclosure is not limited to the above-described embodiments. Various changes, modifications, substitutions, additions, deletions, and combinations are possible within the scope of the claims. These naturally fall within the technical scope of the present disclosure. The entire contents of the specification, claims, drawings, and abstract of Japanese Patent Application No. 2023-125277, filed on August 1, 2023, are hereby incorporated by reference as the disclosure of the specification of the present invention.

[0074] 2 double glazing 10 vacuum glass 11 first glass pane 12 vacuum layer 13 second glass pane 20 gas layer 30 third glass pane

Claims

1. Insulating glass comprising a vacuum glass having a first glass plate, a vacuum layer, and a second glass plate, in that order, in a specified direction, a gas layer, and a third glass plate or laminated glass, in that order, in the specified direction, and the thickness of the third glass plate or laminated glass is greater than the thickness of the vacuum glass.

2. The insulating glass according to claim 1, wherein the difference between the thickness of the third glass sheet or laminated glass and the thickness of the vacuum glass is 0.5 mm or more.

3. The insulating glass according to claim 1 or 2, further comprising a low-emissivity coating on at least one of the mutually opposing first and second surfaces of the first glass sheet and the second glass sheet, and the mutually opposing third and fourth surfaces of the third glass sheet or laminated glass and the vacuum glass.

4. The insulating glass according to claim 1 or 2, wherein at least one of the first glass sheet and the second glass sheet is tempered glass.

5. The insulating glass according to claim 4, wherein the thickness of the tempered glass is 0.5 mm to 2.0 mm.

6. The insulating glass according to claim 1 or 2, wherein the thickness of the gas layer is 3 mm to 20 mm.

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