JP2018012637A - Method for producing double-layered glass - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a double-layered glass capable of suppressing the deflection amount of a glass plate caused by a change in the outer atmospheric pressure, and also, capable of preventing the leakage of a functional gas sealed into a hollow layer.SOLUTION: In the first altitude region, two glass plates 12, 12 are separated by a spacer 14 to laminate them via a hollow layer 16. After that, the edge parts of the two glass plates 12, 12 are adhered with the primary seal material 18 and secondary seal material 20 as seal materials to close the hollow layer 16. Subsequently, the production method includes a pressure reduction step where the pressure of the hollow layer 16 is reduction-adjusted in the first altitude region, and in such a manner that, in the second altitude region having an altitude higher than that of the first altitude region and to be set with a double-layered glass 10, provided that the deflection amount of the two glass plates 12, 12 in the second altitude region of the double-layered glass produced without being subjected to the pressure reduction are defined as the first deflection amount, the deflection amount of the two glass plates 12, 12 in the second altitude region reaches the second deflection amount smaller than the first deflection amount, the two glass plates 12, 12 are deflected at the third deflection amount in the pressure reduction step.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a method for producing a multilayer glass.

  From the viewpoints of heat insulation and soundproofing properties, multiple glass is often used as a glass window. The multi-layer glass is laminated through a hollow layer by separating at least two glass plates with a frame-shaped spacer, and then both side surfaces of the spacer are bonded to the two glass plates with a primary sealing material. It is comprised by sealing the edge part between the glass plates of a sheet | seat with a secondary sealing material. Thereby, the hollow layer pinched | interposed with two glass plates is sealed, and airtightness is improved.

  By the way, the double-glazed glass is hermetic when there is a difference in altitude between the double-glazed glass manufacturing factory (corresponding to the first altitude zone) and the site where the double-glazed glass is installed (corresponding to the second altitude zone). Since the hollow layer held in the wall expands and contracts due to a change in atmospheric pressure, the two glass plates of the multilayer glass are bent. For example, if the altitude at the site where the multi-layer glass is installed is higher than the altitude of the multi-layer glass manufacturing plant, the hollow layer expands, so that the two glass plates bend in a curved direction in a direction away from each other. Mu The amount of bending of the two glass plates increases as the elevation difference increases. For example, when a double-glazed glass manufactured on a flat ground at an altitude of 100 meters or less is transferred to a high place at an altitude of 1500 meters, the double-glazed glass Although it depends on the size, the total value bends about 5 to 6 mm. For this reason, a load is applied to the primary sealing material and the secondary sealing material sealing the hollow layer from the two bent glass plates, and the primary sealing material and the secondary sealing material are fatigued and cracked by the load. When this occurs, there is a concern that the airtightness of the hollow layer is impaired. The amount of bending of the glass plate refers to the maximum value of the amount of deformation from a flat state where the amount of bending is zero.

  In order to solve the above problem, the double-glazed glass of Patent Document 1 is provided with a communication hole communicating with the internal air layer and the outside air in a required portion of any one of the glass plates. It is disclosed that a filter that allows the passage of rainwater and dust is pasted on the communication hole, the filter is peeled off in the field, and the communication hole is sealed with another sealing member. Patent Document 1 also discloses that a sealed air layer is depressurized in advance at a factory in accordance with the external atmospheric pressure.

  On the other hand, in the double-glazed glass of Patent Document 2, a thin tube communicating with the air layer inside the double-glazed glass and the outside air penetrates the spacer and protrudes to the end surface of the double-glazed glass, thereby sealing the outer end of the thin tube in the field. Thus, it is disclosed that the inside of the double-glazed glass is formed into a sealed air layer having the same pressure as the external air pressure.

JP-A-62-13681 JP-A-4-189997

  It is well known that a heat insulating gas, which is a functional gas, is sealed in a hollow layer of a multilayer glass, and the multilayer glass has heat insulating properties. Since the heat insulating gas sealed in the hollow layer leaks from the through-hole, there is a drawback that it cannot be formed into a double-glazed glass having heat insulating properties. Similarly, in the double-glazed glass of Patent Document 2 in which the thin tube is open to the outside, the heat insulating gas enclosed in the hollow layer leaks out from the thin tube, so that it cannot be formed into a double-glazed glass having heat insulation properties. was there.

  On the other hand, Patent Document 1 discloses that a sealed air layer is depressurized in advance at a factory in accordance with an external atmospheric pressure. When this multilayer glass is illustrated and described, the hollow layer 2 of the multilayer glass 1 manufactured in a factory in a low place as shown in FIG. The two glass plates 3 and 3 of the multilayer glass 1 are reduced in advance in accordance with the external pressure of the glass so that the glass interval between the two glass plates 3 and 3 is reduced in the factory of FIG. It bends greatly. For this reason, there exists a concern that the primary sealing material 4 and the secondary sealing material 5 which are sealing the hollow layer 2 will be fatigued, and the airtightness of the hollow layer 2 will be impaired. For example, assuming that the multi-layer glass 1 is manufactured at a low place and installed at a high place of 1500 meters, it is necessary to bend the amount of bending of the two glass plates 3 and 3 by about 5 to 6 mm in total. Therefore, there is a concern that not only the primary sealing material 4 and the secondary sealing material 5 are damaged, but also the glass plate 3 is damaged.

  This invention is made | formed in view of such a situation, can suppress the bending amount of the glass plate resulting from the change of external atmospheric pressure, and prevents the leakage of the functional gas enclosed by the hollow layer. An object of the present invention is to provide a method for producing a multilayer glass.

  According to one aspect of the present invention, in order to achieve the object of the present invention, in the first elevation zone, at least two glass plates are laminated with a spacer by being separated by a spacer, and then two glasses are laminated. A method for producing a double-glazed glass in which a hollow layer is hermetically sealed by adhering an edge portion of a plate with a sealing material, the method comprising: a depressurization step of depressurizing and adjusting a pressure of the hollow layer in a first elevation zone; The second altitude zone where the altitude is higher than the altitude zone and the double glazing is installed, and the amount of bending of the two glass plates in the second altitude zone of the double glazing produced without going through the decompression process is In the decompression step, the two glass plates are placed in the second depressing step so that the amount of bending of the two glass plates in the second altitude zone is a second amount of bending that is smaller than the first amount of bending. Provided is a method for producing a double-glazed glass that is bent by three bending amounts. .

  According to the method for producing a multilayer glass of one embodiment of the present invention, it is possible to suppress the amount of bending of the glass plate due to a change in the external air pressure, and to prevent leakage of the functional gas sealed in the hollow layer. be able to.

  In addition, according to one aspect of the present invention, in the third elevation zone between the first elevation zone and the second elevation zone, the third deflection amount so that the deflection amount of the two glass plates becomes zero. Is preferably set.

  In one embodiment of the present invention, the first altitude zone is 0 to 300 meters above sea level, the second altitude zone is 1000 to 1500 meters above sea level, and the third altitude zone is 300 meters above sea level. It is preferable that it is less than 1000 meters.

  In one embodiment of the present invention, the pressure reduction of the hollow layer is preferably adjusted after the sealing material is cured.

  Further, according to one embodiment of the present invention, the pressure reduction of the hollow layer can be performed by arranging a suction pipe through the sealing material and the spacer, connecting the suction means to the suction pipe, and driving the suction means to generate air in the hollow layer. The first pressure reducing step of sucking through the suction pipe, and the amount of deflection of the two glass plates that change in the first pressure reducing step are measured by the amount of deflection measuring means, and the measured amount of deflection becomes the third amount of deflection. It is preferable to include a second depressurization step that, when reached, seals the conduit of the suction pipe and maintains the pressure of the hollow layer at a reduced pressure.

  According to the multilayer glass manufacturing method of the present invention, it is possible to suppress the amount of bending of the glass plate due to the change in the atmospheric pressure, and to prevent the functional gas enclosed in the hollow layer from leaking out. it can.

Main section enlarged cross-sectional view of double-glazed glass before decompression adjustment Explanatory drawing which showed the manufacturing method of the multilayer glass concerning this invention notionally The figure which exaggerated and showed the bending state of the glass plate in the 1st thru | or 3rd altitude zone The flowchart which showed the manufacturing method of the multilayer glass including the pressure reduction process which concerns on embodiment 4 is a schematic diagram of a manufacturing method corresponding to the flowchart. Table showing an example of an actual measurement value of “−deflection amount β” which is the third deflection amount Explanatory drawing which showed an example of the manufacturing method of the conventional multilayer glass

  Hereinafter, preferred embodiments of a method for producing a multilayer glass according to the present invention will be described with reference to the accompanying drawings.

[Multilayer glass 10]
FIG. 1 is a cross-sectional view of an essential part showing a configuration of a double-glazed glass 10 before pressure reduction adjustment of an embodiment.

  The multilayer glass 10 includes two glass plates 12 and 12 and a frame-shaped spacer 14 which are configured in a rectangular shape. The two glass plates 12 and 12 are separated by a spacer 14, and a hollow layer 16 is formed between the two glass plates 12 and 12. Both sides 14A of the spacer 14 are bonded to the two glass plates 12 and 12 by a primary sealing material 18 such as a butyl sealant, and are attached to the concave portion 13 at the edge between the two glass plates 12 and 12. The secondary sealing material 20 such as a silicone-based sealing material, a polysulfide-based sealing material, a polyurethane-based sealing material, and a butyl-based sealing material is sealed. Thereby, the hollow layer 16 sandwiched between the two glass plates 12 and 12 is sealed. The spacer 14 is constituted by a hollow pipe material, and the hollow portion 14B of the spacer 14 is filled with a drying material 22 such as zeolite. Further, the spacer 14 is formed with a through hole 14 </ b> C that communicates the hollow portion 14 </ b> B and the hollow layer 16, whereby the air in the hollow layer 16 is dried by the desiccant 22. In addition, the hollow layer 16 is preliminarily filled with a heat insulating gas (an inert gas such as argon gas or krypton glass) that is a functional gas, so that the multilayer glass 10 is provided with heat insulating properties.

  As a method for enclosing the heat insulating gas in the hollow layer 16, for example, a through hole penetrating the hollow layer 16 is formed in a corner key (not shown) located in a corner portion of the spacer 14, and gas is supplied from the through hole to the hollow layer 16. Insulating gas is injected by an injection device. After the insulative gas is injected, the through hole of the corner key is sealed with a cap (not shown). Thereafter, the above-described secondary sealing material 20 is sealed in the concave portion 13 at the edge between the two glass plates 12 and 12. The heat insulating gas can be enclosed in the hollow layer 16 by the above operation.

  The heat insulating gas may be sealed when the two glass plates 12 and 12 and the spacer 14 are bonded together, and the multilayer glass 10 having a through hole is placed in a sealed space, and the air in the space is placed. May be sealed with a vacuum pump and replaced with a gas instead.

  The glass plate 12 of the multilayer glass 10 may be a so-called float glass manufactured by a float process, or may be fireproof glass such as template glass or netted glass, or laminated glass. Moreover, the number of the glass plates 12 is not limited to two, and may be a multi-layer glass provided with at least two glass plates. For example, in a multi-layer glass including first to third glass plates, a first spacer is formed between a first glass plate and a second glass plate to form a first hollow layer, and a second glass plate and a third glass plate are provided. The second spacer is disposed between the glass plate and the second hollow layer.

[Manufacturing Method of Multilayer Glass 10]
The manufacturing method of the multilayer glass 10 which concerns on embodiment laminates | stacks through the hollow layer 16 by separating the at least 2 glass plate 12 and 12 by the spacer 14 in a 1st altitude zone. Then, the hollow layer 16 is sealed by bonding the edge portions of the two glass plates 12 and 12 with the primary sealing material 18 and the secondary sealing material 20 which are sealing materials. Then, it has a pressure reduction process for reducing the pressure of the hollow layer 16 in the first elevation zone, is a second elevation zone where the altitude is higher than the first elevation zone and the multi-layer glass 10 is installed. When the amount of bending of the two glass plates 12 and 12 in the second elevation zone of the multi-layer glass produced without going through the process is defined as the first deflection amount, the two glass plates 12 in the second elevation zone, In the decompression step, the two glass plates 12 and 12 are bent by the third bending amount so that the bending amount of 12 becomes a second bending amount smaller than the first bending amount. By undergoing these steps, the multilayer glass 10 of the embodiment is manufactured. This will be specifically described below.

  FIG. 2 is an explanatory view conceptually showing the method for producing the multilayer glass 10 according to the embodiment. The vertical axis in FIG. 2 indicates the altitude (altitude above sea level), and the horizontal axis indicates the amount of bending of the glass plate 12. Further, the first to third multi-layer glasses 10A, 10B, and 10C schematically shown in FIGS. 2 and 3 exaggerately show the bending state of the glass plate 12 in the first to third elevation zones. It is a thing. 2 and 3 and the double-glazed glass 10 shown in FIG. 1 are given the same reference numerals but have the same configuration.

  The first elevation zone described in the embodiment is a zone where a manufacturing factory for producing the double-glazed glass 10 is erected, preferably 0 meters to less than 300 meters above sea level, more preferably 0 meters to 100 meters below sea level. The lowland. The second altitude zone is a site where the double-glazed glass 10 is installed, and is preferably a high place of 1000 to 1500 meters above sea level. The third elevation zone is a zone between the first elevation zone and the second elevation zone, preferably a height of 300 to 1,000 meters above sea level, more preferably a height of 500 to 750 meters above sea level. It is.

  In the manufacturing method of the multi-layer glass 10 of the embodiment, the pressure of the hollow layer 16 is adjusted to be reduced in the manufacturing factory (first elevation zone), and the two glass plates 12 and 12 are respectively subjected to a third deflection amount (in FIG. 2). The pressure reducing step is preliminarily bent by “−β”). In this decompression step, the third deflection amount (“2” in FIG. 2) is set so that the deflection amounts of the two glass plates 12 and 12 of the multilayer glass 10C in the third elevation zone become zero (“0” in FIG. 2). -Β ") is set.

  Here, the bending amount of the glass plate 12 is defined. The glass interval between two flat glass plates 12 and 12 with zero deflection is defined as the reference interval, and the deflection amount in the direction in which the glass interval increases from the reference interval is defined as “+ deflection amount”. The amount of bending in the direction in which the angle becomes narrower is defined as “−the amount of bending”. Then, the third deflection amount set in the decompression step is “−deflection amount β” as in the multilayer glass 10A, whereby the deflection of the two glass plates 12 and 12 of the multilayer glass 10C in the third altitude zone. The amount is zero.

  Note that “−deflection amount β”, which is the third deflection amount, is set based on the third elevation zone, but is set based on any elevation zone between the first elevation zone and the second elevation zone. May be. However, in order to effectively suppress the bending amount of the glass plate 12 due to the change in the external air pressure, it is preferable to set the “−deflection amount β” that is the third bending amount with reference to the third altitude zone. .

  The glass plates 12 and 12 of the double glazing 10 that have undergone the pressure reduction process in the first elevation zone are bent by the “−deflection amount β” that is the third bend amount as in the double glazing 10A of FIGS. 2 and 3. . When this multi-layer glass 10A is transferred from the first elevation zone to the second elevation zone, the two glass plates 12 and 12 are deflected by “−deflection amount β”, and the amount of deflection by the change in atmospheric pressure. Transforms into zero. Then, when passing through the third altitude zone, it begins to bend at “+ deflection amount”, and in the second elevation zone, the two glass plates 12, 12 are “+ deflection” which is the second deflection amount, like the multi-layer glass 10B. Deflection by amount α ”. This “+ deflection amount α” is “+ deflection amount” (hereinafter referred to as “+ deflection amount”), which is the first deflection amount of the two glass plates in the second altitude zone in the multi-layer glass manufactured without going through the decompression step. Smaller than the amount of bending γ ”). That is, the “+ deflection amount α” that is the second deflection amount becomes smaller by subtracting the “− deflection amount β” that is the third deflection amount from the “+ deflection amount γ” that is the first deflection amount. This subtraction is a subtraction between absolute values. Thereby, the bending amount of the glass plate 12 resulting from the change of external atmospheric pressure which arises when the multilayer glass 10 is transferred from a 1st elevation zone to a 2nd elevation zone can be suppressed. Based on this effect, breakage of the glass plate 12, the primary sealing material 18, and the secondary sealing material 20 of the multilayer glass 10A in the second elevation zone can be prevented.

  On the other hand, the conventional multilayer glass 1 shown in FIG. 7A has only “−deflection amount γ” for offsetting “+ deflection amount γ” that is the first deflection amount in the first elevation zone, that is, Since the glass plate 3 is bent in advance by the same amount as the first bending amount, the load on the glass plate 3, the primary sealing material 4 and the secondary sealing material 5 becomes very large. On the other hand, in the embodiment, since “−deflection amount β” in the first altitude zone is smaller than “−deflection amount γ”, the glass plate 12, the primary sealing material 18, and the secondary sealing material 20 are applied. The load is reduced. Therefore, it is possible to prevent the glass plate 12, the primary sealing material 18 and the secondary sealing material 20 of the multilayer glass 10A from being damaged in the first elevation zone.

  Moreover, the manufacturing method of the laminated glass 10 of embodiment is the 2nd altitude zone, without releasing the hollow layer 16 sealed with the primary sealing material 18 and the secondary sealing material 20 to external air. Since it can be installed, leakage of the heat insulating gas sealed in the hollow layer 16 can be prevented.

  FIG. 4 is a flowchart showing an example of a method for producing the multilayer glass 10 including the pressure reducing step according to the embodiment. 5A to 5D are schematic diagrams of a manufacturing method corresponding to the flowchart of FIG. FIG. 5 shows a stainless steel L-shaped suction tube 24, but the material and shape of the suction tube 24 are not limited thereto.

  According to FIGS. 4 and 5A, first, a through hole 26 for penetrating the one end 24A of the suction tube 24 is formed at a predetermined position of the spacer 14 (S (Step) 10). Next, the spacer 14 is assembled with respect to the two glass plates 12 and 12 (S12). Next, the spacer 14 is bonded to the two glass plates 12 and 12 by the primary sealing material 18 (not shown in FIG. 5A) (S14). Next, as shown in FIG. 5B, one end 24A of the suction tube 24 is disposed through the through hole 26 of the spacer 14 (S16). Next, as described above, a heat insulating gas is injected into the hollow layer 16 from the through hole of the corner key (S18). Further, the heat insulating gas may be injected from the suction pipe 24. In this case, it is preferable to seal the gap between the through hole 26 and the suction pipe 24 with a sealing material such as putty before injecting the heat insulating gas. Next, the secondary sealing material 20 is sealed in the recessed part 13 of the edge part between the two glass plates 12 and 12 (S20). At this time, the other end 24 </ b> B of the suction pipe 24 is exposed from the secondary sealing material 20. In other words, the suction tube 24 is arranged to penetrate through the secondary sealing material 20 and the spacer 14. Then, a glazing channel (not shown) is fitted to three sides excluding the side of the multilayer glass 10 on which the other end 24B of the suction tube 24 is disposed. Thereafter, the multilayer glass 10 is cured until the primary sealing material 18 and the secondary sealing material 20 are cured (S22). This curing period is one day (1 day) as an example.

  When the primary sealing material 18 and the secondary sealing material 20 are cured, as shown in FIG. 5C, a pump 28 as suction means is connected to the other end 24B of the suction pipe 24, and the pump 28 is driven to form a hollow layer. Sixteen heat insulating gases are sucked through the suction pipe 24 (S24: first decompression step).

  During this decompression, the glass plate 12 begins to bend in the direction in which the glass interval becomes narrower from the reference interval, and the amount of deflection is measured by the deflection amount measuring means. When the measured deflection amount reaches “−deflection amount β” which is the third deflection amount, the suction pipe 24 is disconnected from the pump 28 as shown in FIG. Among them, the opening of the other end 24B is sealed with the cap 30, and the pressure of the hollow layer 16 is maintained at a reduced pressure (S26: second decompression step). In addition, as a deflection amount measuring means, a glass plate thickness meter (model number: MG1500) manufactured by EDTM can be used. The cap 30 is made of a material that is used as a sealant for multi-layer glass such as butyl.

  Thereafter, the portion of the suction tube 24 exposed from the multi-layer glass 10 is fixed to the multi-layer glass 10 (equivalent to the multi-layer glass 10A) (S28), and the remaining glazing channel is fitted to the side of the portion. To do. By the above, the multilayer glass 10 of embodiment is manufactured in the factory of a 1st altitude zone. Thereafter, the multilayer glass 10 is packed and shipped to the site of the second altitude zone (S30).

  Next, an example of an actual measurement value of “−deflection amount β” that is the third deflection amount will be described.

  The multilayer glass shown in FIG. 6 (A) uses two float glasses (FL3) having a thickness of 3 mm, and the hollow layer thickness is 16 mm when the deflection amount of the two float glasses is zero. The multilayer glass which is (A16) is shown. 6A has lengths of 500 mm, 1000 mm, and 1500 mm in the H direction as the height direction, and lengths of 500 mm and 1000 mm in the W direction as the width direction. The actual measurement values of “−deflection amount β” × 2 in different sizes are shown. That is, an actual measurement value obtained by adding the deflection amounts of the two float glasses is shown. Furthermore, the elevation of the first elevation zone where the manufacturing plant is located is 67 meters, and the elevation of the third elevation zone is 665 meters. That is, the value of “−deflection amount β” × 2 is an actual measurement value set to zero the deflection amount of the two glass plates in the area of 665 meters above sea level. In the double-glazed glass of FIG. 6 (A), by setting the value of “−deflection amount β” × 2 to 1.80 mm to 2.16 mm, the amount of deflection can be made zero in an area of 665 meters above sea level. did it.

  The multilayer glass shown in FIG. 6 (B) uses a template glass (F4) with a thickness of 4 mm and a float glass (FL3) with a thickness of 3 mm, and the amount of deflection between the template glass and the float glass is zero. A multilayer glass having a hollow layer thickness of 15 mm (A15) is shown. In addition, the double-glazed glass of FIG. 6B has “−deflection amount β in six sizes in which the lengths of the sides in the H direction are 500 mm, 1000 mm, and 1500 mm, and the lengths of the sides in the W direction are 500 mm and 1000 mm. ”× 2 actually measured values are shown. Furthermore, the elevation of the first elevation zone where the manufacturing plant is located is 67 meters, and the elevation of the third elevation zone is 665 meters. That is, the value of “−deflection amount β” × 2 is an actual measurement value set to zero the deflection amount of the two glass plates in the area of 665 meters above sea level. In the double-glazed glass of FIG. 6 (B), by setting the value of “−deflection amount β” × 2 to 1.71 mm to 2.07 mm, the amount of deflection can be made zero in a zone of 665 meters above sea level. did it.

  The multi-layer glass shown in FIG. 6C uses a transparent glass (PHW) with a thickness of 7 mm and a float glass (FL3) with a thickness of 3 mm, and the deflection of the transparent glass and the float glass is zero. In this case, the multilayer glass having a hollow layer thickness of 12 mm (A12) is shown. In addition, the double-glazed glass of FIG. 6C has “−deflection amount β in six sizes in which the lengths of the sides in the H direction are 500 mm, 1000 mm, and 1500 mm, and the lengths of the sides in the W direction are 500 mm and 1000 mm. ”× 2 actually measured values are shown. Furthermore, the elevation of the first elevation zone where the manufacturing plant is located is 67 meters, and the elevation of the third elevation zone is 665 meters. That is, the value of “−deflection amount β” × 2 is an actual measurement value set to zero the deflection amount of the two glass plates in the area of 665 meters above sea level. In the double-glazed glass of FIG. 6C, by setting the value of “−deflection amount β” × 2 to 1.26 mm to 1.53 mm, it is possible to make the deflection amount zero in a zone of 665 meters above sea level. did it.

[Industrial applicability]
As mentioned above, although embodiment of this invention was explained in full detail with drawing, this invention is not limited to embodiment mentioned above, The various design change etc. in the range which does not deviate from the summary of this invention are possible. . For example, although embodiment demonstrated the point which suppresses the deflection amount of the glass plate 12 at the time of transferring a multilayer glass from a low place (factory) to a high place (site), from a high place (factory) to a low place ( The present invention can also be applied to suppressing the amount of bending of the glass plate when the multi-layer glass is transferred to the site).

  DESCRIPTION OF SYMBOLS 10 ... Multi-layer glass 10, 12 ... Glass plate, 13 ... Recessed part, 14 ... Spacer, 16 ... Hollow layer, 18 ... Primary sealing material, 20 ... Secondary sealing material, 22 ... Drying material, 24 ... Suction tube, 26 ... Through hole, 28 ... Pump, 30 ... Cap

Claims (5)

In the first altitude zone, after laminating at least two glass plates with a spacer by separating them with a spacer, the hollow layer is formed by adhering the edge portions of the two glass plates with a sealing material. A method for producing a double-glazed glass, wherein
A depressurizing step of depressurizing the pressure of the hollow layer in the first elevation zone
The second elevation zone in which the multi-layer glass is installed at a higher elevation than the first elevation zone, and the two sheets in the second elevation zone of the multi-layer glass manufactured without the depressurization step. When the amount of bending of the glass plate is the first amount of bending,
In the depressurization step, the two glass plates are subjected to a third deflection amount so that the deflection amount of the two glass plates in the second altitude zone is a second deflection amount smaller than the first deflection amount. A method for producing a double-glazed glass, which is bent at a temperature.   The third bending amount is set so that the bending amount of the two glass plates becomes zero in a third elevation zone having a height between the first elevation zone and the second elevation zone. Item 2. A method for producing a multilayer glass according to Item 1. The first altitude zone is 0 to 300 meters above sea level,
The second altitude zone is not less than 1000 meters above sea level and not more than 1500 meters,
The third elevation zone is at least 300 meters above sea level and less than 1000 meters above sea level.
The manufacturing method of the multilayer glass of Claim 2.   The method for producing a multilayer glass according to any one of claims 1 to 3, wherein the pressure reduction of the pressure of the hollow layer is performed after the sealing material is cured. In order to adjust the pressure of the hollow layer, the suction pipe penetrates through the sealing material and the spacer, the suction means is connected to the suction pipe, and the suction means is driven to suck the air in the hollow layer. A first decompression step of sucking through a tube;
The amount of deflection of the two glass plates that changes in the first pressure reducing step is measured by a deflection amount measuring means, and when the measured amount of deflection reaches the third deflection amount, the conduit of the suction pipe is sealed. A second decompression step of maintaining the pressure of the hollow layer at a reduced pressure;
The manufacturing method of the multilayer glass of any one of Claim 1 to 4 containing this.

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