Sealing material and multilayer glass panel using the same

Abstract

The present invention provides a sealing material and a multilayer glass panel using the same. A multilayer glass panel with high reliability and a sealing material for achieving the same are provided. A sealing material, comprising: a lead-free low-melting glass particle containing vanadium oxide and tellurium oxide, a low-thermal expansion filler particle, and a glass bead as solid components, the volume content of the glass bead in the solid components being 10% or more and 35% or less, the volume content of the lead-free low-melting glass particle in the solid components being greater than the volume content of the low-thermal expansion filler in the solid components.

Description

[0001] This application is a divisional application of Chinese patent application No. 201880076212.4, filed on November 1, 2018, entitled "Sealing Material and Multilayer Glass Panel Using the Same". Technical Field

[0002] This invention relates to sealing materials and multilayer glass panels using the same. Background Technology

[0003] In recent years, there has been a demand for window glass with significantly higher thermal insulation compared to traditional multi-pane windows. To achieve this, the high-vacuum interior of multi-pane windows is necessary to provide superior thermal insulation. Furthermore, for widespread global adoption, the manufacturing costs of multi-pane windows must be carefully considered during development.

[0004] To achieve a high vacuum inside the panels of multi-pane windows, the number of spacers used to ensure internal space within the panels needs to be increased. Spacers are typically made of cylindrical metal. However, metal has high thermal conductivity, so a large number of spacers can sometimes create a contradictory problem: even with increased vacuum, insulation performance may decrease.

[0005] The use of ceramics and glass, which have lower thermal conductivity than metals, for spacers was also considered. However, ceramics and glass are harder than metals. Therefore, it is possible for the panel glass to be scratched, or for the vacuum-insulated multilayer glass panel to break.

[0006] Resins have low thermal conductivity, making them effective alternatives to metals, ceramics, and glass in spacers. However, resins also have lower heat resistance than metals, ceramics, and glass, necessitating hermetic sealing at temperatures below their heat resistance. Therefore, when using resins in spacers, it is difficult to apply conventional lead-based or bismuth-based low-melting-point glasses, which have higher sealing temperatures.

[0007] Furthermore, to prevent breakage caused by high vacuum, ensure safety, and deter crime, tempered glass, which undergoes air-cooling strengthening treatment and is less prone to breakage, is required for panel glass. Tempered glass achieves high strength by forming a compression strengthening layer on its surface. However, the strengthening layer of conventional lead-based and bismuth-based low-melting-point glasses gradually diminishes at heating temperatures above approximately 320°C and disappears completely above approximately 400°C. Therefore, it is difficult to apply tempered glass to panel glass for conventional lead-based and bismuth-based low-melting-point glasses, which have sealing temperatures above 400°C.

[0008] As mentioned above, in order to achieve high vacuum inside the panel and high heat insulation in the vacuum-insulated multilayer glass panel, it is very important to keep the sealing temperature low.

[0009] Patent Document 1 discloses a lead-free low-melting-point glass composition, which, when expressed as oxides, contains 10-60% by mass Ag₂O, 5-65% by mass V₂O₅, and 15-50% by mass TeO₂. The total content of Ag₂O, V₂O₅, and TeO₂ is 75% by mass or more and less than 100% by mass. The remaining portion contains one or more of P₂O₅, BaO, K₂O, WO₃, Fe₂O₃, MnO₂, Sb₂O₃, and ZnO in a range of more than 0% by mass and less than 25% by mass. This Ag₂O-V₂O₅-TeO₂-based lead-free low-melting-point glass has a softening point in the temperature range of 268-320°C, and softens and flows at a significantly lower temperature than conventional lead-based or bismuth-based low-melting-point glasses.

[0010] Patent Document 2 discloses a glass adhesive material containing vanadium-based (V₂O₅-P₂O₅) low-melting-point glass (vanadium phosphate glass) and filler particles, which can be used as an adhesive material for glass panels of flat panel display devices and achieves high bonding strength without devitrification during the sealing process. This glass adhesive material also contains 0.1 to 1.0% by volume of glass beads. The glass beads function as a support for attaching two glass panels at equal intervals.

[0011] Existing technical documents

[0012] Patent documents

[0013] Patent Document 1: Japanese Patent Application Publication No. 2013-32255

[0014] Patent Document 2: Japanese Patent Application Publication No. 2007-320822 Summary of the Invention

[0015] The problem that the invention aims to solve

[0016] The glass composition disclosed in Patent Document 1 can achieve hermetically tight sealing at low temperatures below 320°C. However, as the sealing temperature decreases, there is a tendency for the mechanical strength of the sealing part to decrease. Therefore, there is room for improvement in the reliability of the sealing part.

[0017] The softening point of the vanadium phosphate glass disclosed in Patent Document 2 is about 400°C, and the flow point is about 450°C to 500°C. Therefore, the research on improving the mechanical strength of the sealing part associated with the lower sealing temperature is insufficient.

[0018] The purpose of this invention is to provide a highly reliable multilayer glass panel and a sealing material for achieving it.

[0019] Methods for solving problems

[0020] The sealing material of the present invention comprises: lead-free low-melting-point glass particles containing vanadium oxide and tellurium oxide, low thermal expansion filler particles, and glass beads as solid components. The volume content of glass beads in the solid components is more than 10% and less than 35%, and the volume content of lead-free low-melting-point glass particles in the solid components is greater than the volume content of low thermal expansion filler particles in the solid components.

[0021] Invention Effects

[0022] According to the present invention, it is possible to provide a highly reliable multilayer glass panel and a sealing material for achieving it. Attached Figure Description

[0023] Figure 1A A schematic perspective view of a representative vacuum-insulated multilayer glass panel is shown.

[0024] Figure 1B To show Figure 1A A cross-sectional view of a vacuum-insulated multilayer glass panel and an enlarged cross-sectional view of its sealing part.

[0025] Figure 2 An enlarged cross-sectional view of the sealing portion of a vacuum-insulated multilayer glass panel according to one embodiment is shown.

[0026] Figure 3A This is a schematic perspective view showing the coating process of a sealing material paste as part of a method for manufacturing a vacuum-insulated multilayer glass panel according to one embodiment.

[0027] Figure 3B To show Figure 3A Enlarged cross-sectional view of the periphery of a vacuum-insulated multilayer glass panel.

[0028] Figure 4A This is a schematic perspective view showing the formation process of a heat radiation reflective film and spacers as part of a manufacturing method of a vacuum heat-insulating multilayer glass panel according to one embodiment.

[0029] Figure 4B for Figure 4A A summary cross-sectional view.

[0030] Figure 5A This is a schematic cross-sectional view showing the state in which two glass substrates are overlapped, as part of a method for manufacturing a vacuum-insulated multilayer glass panel according to one embodiment.

[0031] Figure 5B This is a schematic cross-sectional view showing the state in which two glass substrates are fixed, as part of a method for manufacturing a vacuum-insulated multilayer glass panel according to one embodiment.

[0032] Figure 6AThis is a schematic cross-sectional view showing the process of depressurizing the internal space of a vacuum multilayer glass panel as part of a method for manufacturing a vacuum insulated multilayer glass panel according to one embodiment.

[0033] Figure 6B for Figure 6A An enlarged cross-sectional view of the area near the seal.

[0034] Figure 7A This is a schematic cross-sectional view showing the state in which the internal space of the vacuum multilayer glass panel is sealed, as part of a manufacturing method of a vacuum insulated multilayer glass panel according to one embodiment.

[0035] Figure 7B for Figure 7A An enlarged cross-sectional view of the area near the seal.

[0036] Figure 8A A coordinate graph showing the temperature distribution during the process of removing the adhesive resin from the sealant paste.

[0037] Figure 8B A coordinate graph showing the temperature distribution when the sealing part is heated during the process of depressurizing the internal space of a vacuum multilayer glass panel.

[0038] Figure 9 A coordinate graph illustrating an example of a representative differential thermal analysis (DTA) curve characteristic of glass.

[0039] Figure 10A This is a schematic perspective view showing a part of a manufacturing method simulating the sealing part of a vacuum-insulated multilayer glass panel, in which a sealing material paste and spacers are placed on a glass substrate.

[0040] Figure 10B To show in Figure 10A A schematic perspective view of the process of overlapping one glass substrate onto another glass substrate.

[0041] Figure 11A To show Figure 10B A summary cross-sectional view of the process of pressing two glass substrates after the first process.

[0042] Figure 11B To show Figure 11A A summary cross-sectional view of the state at the end of the process.

[0043] Figure 12 This is a schematic cross-sectional view of a portion of a test apparatus simulating the bonding strength of a seal in a vacuum-insulated multilayer glass panel.

[0044] Figure 13A graph showing the relationship between the increase in joint strength of the joint in a simulated vacuum-insulated multilayer glass panel and the volume content of spherical glass beads in the solid component of the sealant paste.

[0045] Figure 14 To illustrate the improvement rate of joint strength of the joint in a simulated vacuum-insulated multilayer glass panel, the average particle size (D) of the spherical glass beads in the solid component of the sealing material paste is compared with that of the joint. 50 A coordinate graph showing the relationship between ).

[0046] Figure 15 A schematic cross-sectional view showing the reliability testing apparatus for vacuum-insulated multilayer glass panels. Detailed Implementation

[0047] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, the present invention is not limited to the embodiments listed herein, and appropriate combinations and modifications can be made without changing the spirit of the invention.

[0048] (Vacuum-insulated multi-layered glass panel)

[0049] Vacuum-insulated multilayer glass panels (also simply referred to as "multilayer glass panels") used in architectural windows and the like have an internal space between two glass substrates via multiple spacers. This internal space is in a vacuum state, and to maintain this vacuum state for a long time, the periphery of the two glass substrates is airtightly sealed. For this airtight seal, a sealing material containing low-melting-point glass and low-thermal-expansion filler particles is used, resulting in an airtight seal where the low-thermal-expansion filler is dispersed within the low-melting-point glass. Furthermore, in vacuum-insulated multilayer glass panels, the distance between the two glass substrates (i.e., the height of the spacers and the thickness of the airtight seal) is typically in the range of 100–300 μm.

[0050] Figure 1A A schematic perspective view of a representative vacuum-insulated multilayer glass panel is shown.

[0051] Figure 1B To and Figure 1A The corresponding cross-sectional view is also enlarged to show its airtight sealing part.

[0052] exist Figure 1A In this process, the vacuum-insulated multilayer glass panel includes a first glass substrate 1 and a second glass substrate 2, as well as a spacer 3 and a sealing portion 4 sandwiched between them. The sealing portion 4 is provided at the periphery of the first glass substrate 1 and the second glass substrate 2.

[0053] In addition, such as Figure 1BAs shown, an internal space 5 is formed by a region surrounded by a first glass substrate 1, a second glass substrate 2, and a sealing portion 4. A heat radiation reflective film 6 is attached to the inner surface of the second glass substrate 2. A plurality of spacers 3 are arranged to support the first glass substrate 1 and the second glass substrate 2 in such a way that the distance between the first glass substrate 1 and the second glass substrate 2 is a predetermined value. Generally, it is desirable that this distance be constant.

[0054] In vacuum-insulated multilayer glass panels, for the first glass substrate 1 and the second glass substrate 2, a coefficient of thermal expansion of (80~90)×10 is typically used. -7 Sodium-calcium glass substrates within the range of / ℃.

[0055] like Figure 1B As shown in the enlarged view, the sealing part 4 includes low-melting-point glass 7 and low-thermal-expansion filler particles 8. The low-thermal-expansion filler particles 8 are dispersed in the low-melting-point glass 7. The sealing part 4 is used to achieve and maintain a vacuum state in the internal space 5 for a long period of time. The low-thermal-expansion filler particles 8 are mixed to adapt the coefficient of thermal expansion of the sealing part 4 to the coefficient of thermal expansion of the first glass substrate 1 and the second glass substrate 2.

[0056] Thermal radiation reflective film 6 is useful and commonly used when applying vacuum-insulated multilayer glass panels to architectural window glass.

[0057] In such a vacuum-insulated multilayer glass panel, the sealing temperature is largely determined by the softening flow characteristics resulting from the heating temperature of the low-melting-point glass 7 used in the sealing section 4. That is, the lower the softening point of the low-melting-point glass 7 used, the lower the sealing temperature can be. However, on the other hand, the lower the softening point of the low-melting-point glass 7 used, the greater the tendency for mechanical strength to decrease. Furthermore, in this case, the coefficient of thermal expansion tends to increase. To address this, it is necessary to increase the volumetric content of the low-thermal-expansion filler particles 8 contained in the sealing section 4.

[0058] Figure 2 A cross-section of the sealing portion of a representative vacuum-insulated multilayer glass panel according to one embodiment is shown in magnified view.

[0059] Figure 2 Zhongyu Figure 1B The difference in the magnified image is that spherical glass beads 9 are also dispersed in the low melting point glass 7.

[0060] Low-melting-point glass 7 (lead-free low-melting-point glass) contains vanadium oxide (V₂O₅) and tellurium oxide (TeO₂). This composition enables sealing temperatures below 400°C.

[0061] The volume fraction of glass beads 9 is above 10% and below 35%. The volume fraction of low-melting-point glass 7 is greater than the volume fraction of low thermal expansion filler particles 8.

[0062] By setting the glass bead 9 to the aforementioned volume fraction, aggregation and damage in the sealing portion 4 can be prevented, thus improving mechanical strength. This ensures the reliability of the vacuum-insulated multilayer glass panel. When the volume fraction of the glass bead 9 is less than 10%, the improvement in mechanical strength is barely noticeable; on the other hand, when it exceeds 35%, the sealing portion 4 easily peels off from the interface between the first glass substrate 1 and the second glass substrate 2. It should be noted that the volume fraction of the glass bead 9 is more preferably 20% or more and 30% or less.

[0063] Furthermore, when the low-melting-point glass 7 contains silver oxide (Ag₂O), the sealing temperature can be lower than 320°C. Therefore, a resin with low thermal conductivity can be used for the spacer 3. This allows for the application of tempered glass subjected to air-cooling strengthening and chemical strengthening treatments to the first glass substrate 1 and the second glass substrate 2. Additionally, by lowering the sealing temperature, the mass production capability of vacuum-insulated multilayer glass panels can be improved, and investment in mass production equipment can be reduced, contributing to a decrease in manufacturing costs.

[0064] Regarding the size of the glass bead 9, its maximum diameter needs to be less than or equal to the distance between the first glass substrate 1 and the second glass substrate 2. Furthermore, its average diameter (D) is preferably [not specified]. 50 The average diameter (D) is more than half of that spacing. 50 The median diameter, also known as the "average particle size," is the diameter of glass beads 9. 50 For example, particle size distribution can be determined by using a laser diffraction / scattering particle size distribution measuring device after grading with a sieve.

[0065] The glass bead 9 is preferably made of the same or similar glass system as the first glass substrate 1 and the second glass substrate 2. This is because the thermal expansion characteristics are the same or similar, thereby stably improving the mechanical strength of the sealing part.

[0066] Specifically, glass beads made of soda-lime glass (SiO2-Na2O-CaO system glass), borosilicate glass (SiO2-B2O3-Na2O system glass), quartz glass (SiO2) are preferred.

[0067] It should be noted that in this specification, glass beads are defined as approximately spherical glass. Furthermore, in vacuum-insulated multilayer glass panels, low thermal expansion filler particles 8 are introduced to adapt the thermal expansion of the sealing portion 4 to the thermal expansion of the first glass substrate 1 and the second glass substrate 2. However, when the volume content of the low melting point glass 7 is higher than the aforementioned, the softening and fluidity of the low melting point glass 7 during heat sealing decreases, making it difficult to achieve an airtight seal. Therefore, it is necessary to ensure that the volume content of the low melting point glass 7 is greater than the volume content of the low thermal expansion filler particles 8. More preferably, setting the volume content of the low melting point glass 7 to 35% or higher is effective. Additionally, the volume content of the low melting point glass 7 is preferably 72% or less.

[0068] When the low-melting-point glass 7 further comprises any one or more of oxides (WO3), barium oxide (BaO), potassium oxide (K2O), and phosphorus oxide (P2O5) as glass components, vitrification during glass production becomes easier. Using such a composition reduces the tendency of the produced low-melting-point glass 7 to crystallize. When the low-melting-point glass 7 has a high tendency to crystallize, problems arise such as crystallization during heat sealing, poor softening and flow characteristics, and insufficient airtightness of the sealing part 4.

[0069] Furthermore, it is effective to further include any one or more of alumina (Al2O3), iron oxide (Fe2O3), yttrium oxide (Y2O3), and lanthanum oxide (La2O3) as the glass composition. Even in small amounts, these components help to prevent or significantly inhibit crystallization. As a result, a highly airtight sealing section 4 is obtained.

[0070] Low thermal expansion filler particles 8 can be, for example, particles formed from zirconium tungstate phosphate (Zr2(WO4)(PO4)2), quartz glass, β-lithium nepheline or cordierite.

[0071] Of these, zirconium tungstate phosphate is effective. Zirconium tungstate phosphate has a large negative thermal expansion, with a coefficient of thermal expansion of -40 × 10⁻⁶. -7 / ℃. Furthermore, the low thermal expansion filler particles 8 exhibit good wettability and adhesion to the aforementioned low melting point glass 7, thus achieving a significant effect of low thermal expansion and easily adapting the thermal expansion of the sealing portion 4 to the thermal expansion of the glass substrate. The average particle size (D) of the low thermal expansion filler 50 The particle size is preferably 3μm or larger and 20μm or smaller. By setting it to 3μm or larger and 20μm or smaller, the generation of cracks at the interface can be suppressed, and the effect of adjusting the coefficient of thermal expansion can be achieved. It should be noted that the average particle size (D) of the low thermal expansion filler... 50 The particle size distribution can be measured using a laser diffraction / scattering particle size distribution measuring device.

[0072] In particular, when lead-free low-melting-point glass containing vanadium oxide (V₂O₅), tellurium oxide (TeO₂), and silver oxide (Ag₂O) is used in the sealing part, the sealing temperature can be lowered, so the spacer 3 described above can be made of a resin with low thermal conductivity. Specific resins include polyimide resin, polyamide resin, fluoropolymer resin, epoxy resin, phenoxy resin, and silicone resin.

[0073] Generally, resin is softer than metal, ceramic, and glass, so when used as spacer 3, it will not scratch the first glass substrate 1 or the second glass substrate 2, causing them to break. Furthermore, if hardness is required for spacer 3, glass particles or ceramic particles can be dispersed in the resin as filler materials.

[0074] The vacuum-insulated multilayer glass panel described in this embodiment exhibits excellent thermal insulation, mass production capabilities, and reliability, making it particularly effective for architectural windows. Furthermore, it is easily and widely adopted in residential and building applications worldwide. This allows for the reduction of CO2 emissions by decreasing energy consumption, contributing to efforts to combat global warming. In addition to architectural windows, this vacuum-insulated multilayer glass panel can also be widely applied to applications requiring thermal insulation, such as vehicle windows, commercial refrigerators, and freezer doors.

[0075] (Sealing paste)

[0076] Figure 2 The sealing portion 4 of the vacuum-insulated multilayer glass panel shown is typically formed using a sealing paste. The sealing paste comprises: particles of low-melting-point glass 7 containing vanadium oxide (V2O5) and tellurium oxide (TeO2), low thermal expansion filler particles 8, glass beads 9, adhesive resin, and solvent.

[0077] To clarify, in this specification, the solid components of these sealing material pastes are described as low-melting-point glass 7, low-thermal-expansion filler particles 8, and glass beads 9. This is because the adhesive resin and solvent vaporize during drying and firing, and are essentially not present in the finished sealing part 4.

[0078] Furthermore, regarding the volumetric content of the solid components, it is calculated using the sum of the true volumes of the three constituent elements of the solid components mentioned above as the basis (denominator). This is because it is assumed that the sealing part 4 substantially does not contain voids. In this specification, even when the description of "volume content" related to "solid components" is simply stated as "volume content," it still refers to "volume content of the solid components." Volume content is the content based on volume, and the unit is volume %. It should be noted that in this specification, volume % is sometimes simply expressed as "%."

[0079] The volume fraction of glass beads 9 in the solid composition is 10% or more and 35% or less. In addition, it is desirable that the volume fraction of low-melting-point glass 7 particles in the solid composition is greater than the volume fraction of low thermal expansion filler particles 8 in the solid composition.

[0080] Furthermore, regarding the size of the glass beads 9 in the solid component, when considering the spacing between the first glass substrate 1 and the second glass substrate 2 of the vacuum-insulated multilayer glass panel (i.e., the height of the spacer 3 and the thickness of the sealing portion 4), the average diameter (D) of the glass beads 9 is... 50 The thickness is preferably 50 μm or more and 200 μm or less. This is because, typically, the thickness of the gap (i.e., the height of the spacer 3 and the sealing portion 4) between the first glass substrate 1 and the second glass substrate 2 of a vacuum heat-insulating multilayer glass panel is usually in the range of 100 to 300 μm.

[0081] From the viewpoint of improving the strength of the sealing part 4, a volume content of glass beads 9 in the solid composition of 20% or more and 30% or less is particularly effective. Furthermore, a volume content of low-melting-point glass 7 particles in the solid composition of 35% or more is particularly effective. Moreover, a volume content of low-melting-point glass 7 particles of 7 of 7 is effectively 72% or less.

[0082] When considering the influence of the adhesive resin contained in the sealing paste on the softening, flowability, and crystallization of the low-melting-point glass 7, it is preferably any one or more of ethyl cellulose, nitrocellulose, and aliphatic polycarbonate. Similarly, when considering the influence of the solvent on the low-melting-point glass 7, it is preferably any one or more of butyl carbitol acetate, terpene solvents, and propylene carbonate.

[0083] By applying the aforementioned sealing material paste to the sealing portion 4 of the vacuum-insulated multilayer glass panel, the sealing temperature can be lowered, and high airtightness and sealing strength can be obtained. Furthermore, since the spacer 3 can be made of resin and the first glass substrate 1 and the second glass substrate 2 can be made of tempered glass, the thermal insulation, mass production, and reliability of the vacuum-insulated multilayer glass panel can be improved.

[0084] (Manufacturing method of vacuum-insulated multilayer glass panel)

[0085] use Figures 3A-7B The exhaust pipe method is described as an example of a series of manufacturing methods for a representative vacuum multilayer glass panel.

[0086] Figure 3A A perspective view showing the application process of the sealant paste.

[0087] Figure 3B for Figure 3A A partially enlarged cross-sectional view.

[0088] Figure 4 is a perspective view showing the state in which a thermal radiation reflective film and spacers are formed.

[0089] Figure 4B for Figure 4A Cross-sectional view.

[0090] Figure 5A A cross-sectional view showing the state of the two glass substrates combined.

[0091] Figure 5B A cross-sectional view showing the state in which the two glass substrates are fixed.

[0092] Figure 6A A cross-sectional view showing the process of depressurizing the internal space of a vacuum multilayer glass panel.

[0093] Figure 6B for Figure 6A A partially enlarged cross-sectional view.

[0094] Figure 7A A cross-sectional view showing the state in which the internal space of a vacuum multilayer glass panel is sealed.

[0095] Figure 7B for Figure 7A A partially enlarged cross-sectional view.

[0096] Figure 8A A coordinate graph showing the temperature distribution during the process of removing the adhesive resin from the sealant paste.

[0097] Figure 8B A coordinate graph showing the temperature distribution when the sealing part is heated during the process of depressurizing the internal space of a vacuum multilayer glass panel.

[0098] First, such as Figure 3A As shown, a sealant paste 13 is applied to the periphery of the first glass substrate 1, which has vent holes 10 and vent pipes 11, using a dispenser 12. Then, it is dried on a hot plate at about 150°C for 30 minutes to evaporate and remove the solvent from the sealant paste 13.

[0099] Subsequently, according to Figure 8A The temperature distribution shown decomposes and removes the adhesive resin of the sealant paste. Subsequently, the sealant 14 is fired onto the first glass substrate 1 by softening and flowing the low-melting-point glass 7 particles contained in the sealant paste 13.

[0100] Regarding its firing conditions, such as Figure 8A As shown, the heating and cooling rates in the atmosphere are set to 2°C / minute. During the heating process, the yield point M of the low-melting-point glass 7 is measured. g and softening point T sThe adhesive resin is temporarily maintained at a certain temperature T1 for about 30 minutes to decompose and remove it. Afterwards, the temperature is raised again to a temperature higher than the softening point T. s A certain temperature T2, which is 20 to 40°C higher, is maintained for about 30 minutes, thereby forming a sealing material 14 at the periphery of the first glass substrate 1.

[0101] After the aforementioned process, the sealant paste 13 is transformed into sealant 14.

[0102] On the other hand, in the second glass substrate 2, such as Figure 4A and Figure 4B As shown, a thermal radiation reflective film 6 is formed on a single surface using a vapor deposition method. Then, a plurality of spacers 3 are attached to the surface of the thermal radiation reflective film 6.

[0103] Next, as Figure 5A As shown, the first glass substrate 1 and the second glass substrate 2, fabricated in the above process, are aligned and overlapped (fitted). Then, as... Figure 5B As shown, it is fixed with heat-resistant clips 15, etc.

[0104] Take it as Figure 6A As shown, an electric heater 17 is installed inside the vacuum exhaust furnace 16, and the exhaust pipe 11 is connected to the vacuum pump 18.

[0105] With Figure 8B The sealing temperature distribution shown is achieved by first heating at atmospheric pressure to the yield point M of the low-melting-point glass 7 contained in the sealing material 14. g and softening point T s Maintain a constant temperature T3 for approximately 30 minutes. Afterward, while... Figure 6A and Figure 6B The exhaust port 10 and exhaust pipe 11 shown exhaust the internal space 5 while heating it to a temperature lower than the softening point T. s A temperature T4 that is 10 to 30°C higher. As a result, a sealing part 4 is formed at the periphery using sealing material 14, while the internal space 5 is made into a vacuum state.

[0106] Next, as Figure 7A and 7B As shown, by burning off the exhaust pipe 11 with an electric heater 17 during or after cooling, the vacuum state of the internal space 5 can be maintained.

[0107] As described above, vacuum-insulated multi-layered glass panels are manufactured.

[0108] Example

[0109] The present invention will now be described in further detail based on specific embodiments. However, the present invention is not limited to the embodiments described herein, but includes variations thereof.

[0110] In order to manufacture the vacuum-insulated multilayer glass panel of the present invention, firstly, 42 types of lead-free low-melting-point glass were tested for use in making the sealant paste.

[0111] Table 1 shows the composition and properties of the prototype lead-free low-melting-point glass.

[0112] Table 1

[0113]

[0114] These lead-free low-melting-point glasses, G-01 to G-42, are designed to be essentially free of harmful lead and other environmental and safety concerns.

[0115] As glass raw materials, powders of V2O5 produced by Shinshin Chemical, TeO2 produced by the High Purity Chemical Research Institute, Ag2O produced by Wako Pure Chemical, WO3 produced by the High Purity Chemical Research Institute, BaCO3 produced by the High Purity Chemical Research Institute, K2CO3 produced by the High Purity Chemical Research Institute, P2O5 produced by the High Purity Chemical Research Institute, Al2O3 produced by the High Purity Chemical Research Institute, Fe2O3 produced by the High Purity Chemical Research Institute, Y2O3 produced by the High Purity Chemical Research Institute, La2O3 produced by the High Purity Chemical Research Institute, and ZnO produced by the High Purity Chemical Research Institute were used.

[0116] The glass raw materials were weighed, mixed, and prepared in batches of approximately 200–300 g, and then placed into a platinum or quartz crucible. The crucible was placed in a glass melting furnace (electric furnace) and heated to 750–950 °C at a rate of approximately 10 °C / min. To ensure uniform molten metal in the crucible, the mixture was stirred with an alumina rod and kept at this temperature for 1 hour. Afterward, the crucible was removed from the furnace, and the molten metal was allowed to flow into a stainless steel plate. Lead-free low-melting-point glasses G-01–42, as shown in Table 1, were then produced.

[0117] For V2O5-TeO2-based lead-free low-melting-point glasses G-01 to G-09, platinum crucibles are used; for V2O5-TeO2-Ag2O-based lead-free low-melting-point glasses G-10 to G-42, quartz crucibles are used. Furthermore, G-01 to G-09 are melted at 950℃, G-10 to G-19 at 850℃, and G-20 to G-42 at 750℃.

[0118] The density, characteristic temperature, and coefficient of thermal expansion of lead-free low-melting-point glasses G-01 to G-42 were determined. The characteristic temperature was measured using differential thermal analysis (DTA) of the glass powder. A large sample pan (macrocell) was used to clearly represent the characteristic points of the glass's DTA curve.

[0119] Figure 9 An example of a DTA curve for a representative glass is shown.

[0120] exist Figure 9 In the middle, the starting temperature of the first endothermic peak is the glass transition point T. g Its endothermic peak temperature is the yield point M. g The second endothermic peak temperature is the softening point T. s Generally, these characteristic temperatures are determined using the tangent method. Each characteristic temperature is defined by the viscosity of the glass, T. g Equivalent to 10 13.3 The temperature of the lake, M g Equivalent to 10 11.0 The temperature of the lake, and T s Equivalent to 10 7.65 The temperature of the lake.

[0121] Next, the prototype lead-free low-melting-point glass G-01 to G-42 was pulverized to an average particle size (D) using a jet mill. 50 The particle size is approximately 1–3 μm, and it is used in sealant pastes. It should be noted that the average particle size (D) of lead-free low-melting-point glass is... 50 The measurements were performed using a laser diffraction / scattering particle size distribution measuring device LA-950V2 manufactured by Horiba Manufacturing Co., Ltd.

[0122] Tables 2 and 3 show the low thermal expansion filler particles and spherical glass beads used in the sealing material paste of the present invention.

[0123] Low thermal expansion filler particles use average particle size (D) 50 Particles ranging from 5 to 15 μm in size. Their average particle size (D...) 50 The particle size distribution was measured using a laser diffraction / scattering particle size analyzer LA-950V2 manufactured by Horiba Manufacturing Co., Ltd. Spherical glass beads were graded using sieves to obtain the desired size range. The average diameter (D) was... 50 The measurements were performed using a laser diffraction / scattering particle size distribution measuring device LA-950V2 manufactured by Horiba Manufacturing Co., Ltd.

[0124] Table 2

[0125] Table 2 Density and coefficient of thermal expansion of low thermal expansion filler particles

[0126]

[0127] Table 3

[0128] Table 3 Density and coefficient of thermal expansion of spherical glass beads

[0129]

[0130] A sealant paste was prepared using lead-free low-melting-point glass particles from Table 1, low-thermal-expansion fillers from Table 2, spherical glass beads from Table 3, resin binders, and solvents.

[0131] As the adhesive resin, ethyl cellulose or nitrocellulose is used when using lead-free low-melting-point glasses G-01 to G-09, and aliphatic polycarbonate is used when using lead-free low-melting-point glasses G-10 to G-42. As the solvent, butyl carbitol acetate is used when using lead-free low-melting-point glasses G-01 to G-09, and both propylene carbonate and terpene solvents are used when using lead-free low-melting-point glasses G-10 to G-42.

[0132] [Example 1]

[0133] In this embodiment, a joint simulating the sealing portion of the vacuum-insulated multilayer glass of the present invention was fabricated using the sealing material paste of the present invention, and the reliability of the joint was evaluated. Specifically, two glass substrates were joined using the sealing material paste of the present invention, and the joint strength of the joint was evaluated using shear stress. As a comparative example, a sealing material paste without spherical glass beads was used, and the effectiveness of containing glass beads was confirmed based on this.

[0134] The method for manufacturing the joint in this embodiment is shown below. Figures 10A-11B .

[0135] Figure 10A This is a schematic perspective view showing a state in which a sealant paste and spacers are placed on a glass substrate as part of a manufacturing method for a joint that simulates a vacuum-insulated multilayer glass panel.

[0136] Figure 10B To show in Figure 10A A schematic perspective view of the process of overlapping one glass substrate onto another glass substrate.

[0137] Figure 11A To show Figure 10B A summary cross-sectional view of the process of pressing two glass substrates after the first process.

[0138] Figure 11B To show Figure 11A A summary cross-sectional view of the state at the end of the process.

[0139] The glass substrates 101 and 102 are made of very common soda-lime glass with a thickness of 5 mm. The glass substrate 101 is a square with a size of 20 × 20 mm, and the glass substrate 102 is a square with a size of 10 × 10 mm.

[0140] First, such as Figure 10AAs shown, a sealing material paste 13 is applied to the top surface of the glass substrate 101 to form a diameter of 5 mm and a thickness of approximately 500–600 μm. Then, four metal spacers 3 with a height of 220 μm are disposed. After drying at 150°C for 30 minutes, as shown... Figure 10B As shown, the glass substrate 102 is bonded.

[0141] Then, as Figure 11A As shown, a load of 3N is applied from above the glass substrate 102 while... Figure 8A The temperature distribution shown is combined. At this time, as... Figure 11B As shown, the joint thickness is adjusted to 220 μm using four spacers 3. During this process, the sealant paste 13 is transformed into sealant 14.

[0142] Figure 12 The apparatus for measuring the bonding strength of a joint obtained by the above-described manufacturing method is shown.

[0143] As shown in this figure, the joint consisting of glass substrates 101 and 102, and the sealing material 14 and spacer 3 sandwiched between them, is fixed to the joint fixing fixture 52. Then, an external force is applied to the glass substrate 102 laterally using the shearing fixture 51. At this time, the lower end of the shearing fixture 51 is positioned 500 μm from the top surface of the glass substrate 101. In addition, the moving speed of the shearing fixture 51 is set to 34 μm / second.

[0144] In both the examples and comparative examples, five joints were fabricated simultaneously. The joint strength of each joint, measured under the aforementioned conditions, was used to calculate the average value (average joint strength). The advantages of the sealant paste were evaluated by comparing this average value.

[0145] Regarding the sealing material paste used in this embodiment, the solid components include lead-free low-melting-point glasses G-01 to G-42 as shown in Table 1, low-thermal-expansion filler particles F-01 as shown in Table 2, and spherical glass beads B-14 as shown in Table 3. The volume percentages of the lead-free low-melting-point glasses G-01 to G-42 and the low-thermal-expansion filler particles F-01 in the solid components are determined taking into account the thermal expansion of the soda-lime glass used in the glass substrates 101 and 102. Furthermore, the volume percentage of the spherical glass beads B-14 in the solid components is set to 20-30% by volume. Thus, five joints for each embodiment are fabricated, and the average joint strength is calculated.

[0146] Table 4 shows the volume content of the solid components in the sealant paste, its bonding conditions, and the improvement rate of the bonding strength of the resulting joints.

[0147] It should be noted that the bond strength improvement rate of joints A-01 to A-42 is based on the case where the solid composition does not contain spherical glass beads B-14. That is, the value is calculated by subtracting the average bond strength of the comparative examples from the average bond strength of the joints of the embodiments as the numerator, using the average bond strength of the comparative examples as the denominator. In the case of the comparative examples, i.e., without spherical glass beads B-14, all joints exhibit an average bond strength of approximately 10 to 20 MPa using a shear stress gauge. Furthermore, within this range, the softening point T is used to measure the average bond strength. s The higher the lead-free, low-melting-point glass, the greater its tendency to become larger.

[0148] Table 4

[0149]

[0150] As can be seen from this table, for the joints A-01 to A-42 of the embodiments containing spherical glass beads B-14, the average joint strength is improved compared to the comparative examples.

[0151] When observing the fracture sites of the comparative example joints, it was found that in almost all joints, the following was observed: Figure 12 The sealant 14 is shown as being broken in a state where it is divided vertically, i.e., broken approximately at the center of the 220 μm joint thickness. In contrast, when observing the damaged portions of joints A-01 to A-42 in embodiments containing spherical glass beads B-14, it was confirmed that in all joints, the propagation of cracks in the sealant 14 was suppressed due to the presence of the spherical glass beads B-14. This is believed to be the reason for the increased joint strength.

[0152] Therefore, it can be seen that incorporating spherical glass beads into sealing materials or their pastes is effective in improving the strength, i.e., the reliability, of the joint. Clearly, this can be effectively applied to the airtight sealing of vacuum-insulated multilayer glass at low temperatures.

[0153] [Example 2]

[0154] In this embodiment, the effect of the volume content of spherical glass beads in the solid component of the sealant paste on the bond strength was prepared in the same manner as in Example 1. Figure 11B The bonding bodies were investigated by evaluating their average bonding strength. A sealant paste was prepared using lead-free low-melting-point glass (G-08, G-10, G-25, G-36, and G-42 from Table 1), low thermal expansion filler particles (F-01 from Table 2), spherical glass beads (B-14 from Table 3).

[0155] It should be noted that, similarly to Example 1, the volumetric content ratios of lead-free low-melting-point glasses G-08, G-10, G-25, G-36, and G-42, as well as low-thermal-expansion filler particles F-01, are set constant after considering the thermal expansion of glass substrates 101 and 102, while the volumetric content ratio of spherical glass beads B-14 varies. Compared to G-08 and G-10, lead-free low-melting-point glasses G-25, G-36, and G-42 have larger coefficients of thermal expansion. Therefore, to accommodate the thermal expansion of glass substrates 101 and 102, it is necessary to reduce the volumetric content ratio of lead-free low-melting-point glasses and increase the volumetric content ratio of low-thermal-expansion filler particles.

[0156] Figure 13 A graph showing the relationship between the increase in joint strength and the volume content of spherical glass beads B-14 in the solid component of the sealant paste.

[0157] As shown in the figure, regardless of the type of lead-free low-melting-point glass used, when the volume content of spherical glass beads B-14 is less than 10 vol%, almost no improvement in bond strength is observed. When the volume content of these glass beads is between 10 and 20 vol%, the bond strength increases with increasing volume content, reaching a maximum in the range of 20 to 30 vol%. Above 30 vol%, the bond strength decreases. It should be noted that even above 30 vol%, the rate of increase in bond strength remains positive up to 35 vol%, and the bond strength is higher than in the case without spherical glass beads B-14.

[0158] Regarding the bond strength at 40% by volume, the results are approximately equivalent to those without spherical glass beads B-14 when using lead-free low-melting-point glass G-08 or G-10. However, the results are lower than those without spherical glass beads B-14 when using lead-free low-melting-point glass G-25, G-36, and G-10. Furthermore, the bond strength decreases even when exceeding 40% by volume. This is believed to be because the volume content of lead-free low-melting-point glass is insufficient when bonding glass substrates 101, 102 and spherical glass beads. Therefore, it is believed that the volume content of lead-free low-melting-point glass is lower when using G-25, G-36, or G-42 compared to when using G-08 or G-10, and the rate of decrease in bond strength is greater when the volume content of spherical glass beads B-14 exceeds 35% by volume. It is believed that the volume content of lead-free low-melting-point glass in the solid components of the sealing material paste should be at least 35% by volume.

[0159] As described above, the volume content of glass beads in the sealing paste is preferably 10-35% by volume, and particularly effective is 20-30% by volume. Furthermore, the volume content of lead-free low-melting-point glass is preferably 35% by volume or more. It is also readily apparent that this result will be effectively reflected when applied to the low-temperature hermetic sealing of vacuum-insulated multilayer glass panels.

[0160] Furthermore, in this embodiment, for F-02 to F-04, other than the low thermal expansion filler particles F-01 in Table 2, the same type of conjugate was also fabricated and evaluated and discussed.

[0161] As shown in Table 2, low thermal expansion filler particles F-01 and F-03 have large negative coefficients of thermal expansion. Furthermore, low thermal expansion fillers F-02 and F-04 have coefficients of thermal expansion close to zero. Generally, the smaller the coefficient of thermal expansion of the low thermal expansion filler particles, the easier it is to match the coefficients of thermal expansion of glass substrates 101 and 102. Moreover, in this case, the volume fraction of lead-free low-melting-point glass can be increased, thus proving effective. Considering this, F-03, with the smallest coefficient of thermal expansion in Table 2, becomes the most effective low thermal expansion filler particle.

[0162] However, compared to the low thermal expansion filler particles F-01, F-03 exhibits insufficient wettability with all lead-free low-melting-point glasses G-01 to G-42 of the V2O5-TeO2 and V2O5-TeO2-Ag2O systems shown in Table 1, making it difficult to obtain a dense bond. Furthermore, achieving the desired low coefficient of thermal expansion is challenging. Therefore, even with the introduction of spherical glass beads, the expected improvement in bond strength is not achieved.

[0163] The low thermal expansion filler particle F-04 was also studied, and the results showed that its coefficient of thermal expansion was not as small as that of low thermal expansion filler particle F-03, but the outcome was the same. When using low thermal expansion filler particles F-03 and F-04, it is considered necessary to perform surface treatment on the filler particles to improve the wettability of V2O5-TeO2-based lead-free low-melting-point glass and V2O5-TeO2-Ag2O-based lead-free low-melting-point glass as shown in Table 1.

[0164] Compared to low thermal expansion filler particles F-03 and F-04, low thermal expansion filler particle F-02 exhibits better wettability with V2O5-TeO2-based lead-free low melting point glass and V2O5-TeO2-Ag2O-based lead-free low melting point glass. However, for a low thermal expansion filler particle, F-02's coefficient of thermal expansion is not particularly small.

[0165] When using V2O5-TeO2-Ag2O series lead-free low-melting-point glass with a very high coefficient of thermal expansion as a sealing material paste, the use of low-thermal-expansion filler particles with a negative coefficient of thermal expansion, F-01, is effective among the low-thermal-expansion filler particles shown in Table 2. Clearly, this result can also be effectively applied to the low-temperature hermetically tight sealing of vacuum-insulated multilayer glass panels.

[0166] [Example 3]

[0167] In this embodiment, regarding the average particle size (D) of the spherical glass beads in the solid component of the sealant paste... 50 The effect on the bond strength is similar to that in Example 1, and is fabricated as follows: Figure 11B The average joint strength of the joint shown was evaluated. However, as... Figure 11B The spacer 3 shown is made of metal with a height of 250 μm. In addition, the coating thickness of the sealing material paste 13 is increased to more than 600 μm.

[0168] As lead-free low-melting-point glasses, G-07, G-12, G-24, G-34, and G-39 from Table 1 were used as low-thermal-expansion filler particles, F-01 from Table 2 was used as spherical glass beads, and B-11 to B-15 from Table 3 were used to prepare a sealing material paste. It should be noted that the volume content ratio of lead-free low-melting-point glasses G-07, G-12, G-24, G-34, and G-39 to low-thermal-expansion filler particles F-01 was the same as in Example 1, determined after considering the thermal expansion of glass substrates 101 and 102.

[0169] The spherical glass beads B-11 to B-15, as shown in Table 3, are all made of soda-lime glass from the same raw material as the glass substrates 101 and 102. Regarding their average particle size (D... 50 For example, B-11 has a diameter of 46 μm, B-12 has a diameter of 88 μm, B-13 has a diameter of 125 μm, B-14 has a diameter of 143 μm, and B-15 has a diameter of 184 μm. The height of spacer 3, 250 μm, is taken into account the maximum particle size of spherical glass beads, specifically the average particle size (D). 50 The maximum particle size of B-15 is determined by the largest particle size. In addition, the volume content of spherical glass beads B-11 to B-15 is set to 30% by volume when using lead-free low melting point glass G-07 or G-24, 25% by volume when using G-12, and 20% by volume when using G-34 or G-39.

[0170] Figure 14 To illustrate the increase in joint strength of the joint compared to the average particle size (D) of the spherical glass beads contained in the sealant paste. 50The graph shows the relationship between the volumetric and non-volume components of the glass beads. The areas within square brackets [] represent the volumetric content of the spherical glass beads.

[0171] When using all lead-free low-melting-point glass, the average particle size (D) of the spherical glass beads is... 50 When the diameter is less than 100 μm, the effect on improving the bonding strength is small. On the other hand, in D... 50 With a thickness of 125 μm, a significant improvement in bonding strength is achieved.

[0172] When observing the fracture site of the conglomerate, the average particle size (D) of the spherical glass beads... 50 When the size is less than 100 μm, almost all of them exhibit the following characteristics: Figure 12 The sealing material 14 shown is in a state of damage from top to bottom, that is, damage occurs approximately from the center of the 250 μm bonding thickness. The average particle size (D) of the spherical glass beads... 50 When the thickness of the joint is more than half of 250 μm, exceeding 125 μm, it is confirmed that the propagation of cracks in the sealing material 14 is suppressed due to the spherical glass beads.

[0173] As can be seen from the above, to improve the bonding strength of the joint, the average particle size (D) of the spherical glass beads is increased. 50 A thickness of more than half the joint thickness is effective. Furthermore, it is easy to infer that this result will be effectively reflected in the cryogenic hermetic sealing of vacuum-insulated multilayer glass panels. In vacuum-insulated multilayer glass panels, the spacing between the two glass substrates (i.e., the height of the spacer and the thickness of the seal) is typically in the range of 100–300 μm; therefore, the average diameter (D) of the spherical glass beads is also relevant. 50 A value between 50μm and 200μm is suitable.

[0174] [Example 4]

[0175] In this embodiment, the effect of different raw materials for the spherical glass beads in the solid component of the sealant paste on the bonding strength was handled in the same manner as in Example 1. Figure 11B The average bond strength of the joint was evaluated.

[0176] As lead-free low-melting-point glasses, G-05, G-17, G-33, and G-40 from Table 1 were used as low-thermal-expansion filler particles; F-01 from Table 2 was used as spherical glass beads; and B-14, B-21, and B-31 from Table 3 were used to prepare a sealant paste. The spherical glass beads B-14, B-21, and B-31, as shown in Table 3, use different raw materials but are all graded using the same sieve to achieve a particle size of 75 μm or larger and less than 212 μm. The raw materials for each spherical glass bead are: B-14 is soda-lime glass, B-21 is borosilicate glass, and B-31 is quartz glass. Thus, even with the same particle size range, different raw materials result in different physical properties such as density and coefficient of thermal expansion. Since the coefficient of thermal expansion of the spherical glass beads is different, this was also considered in this embodiment, and the volume content of each solid component in the sealant paste was determined to adapt to the thermal expansion of the glass substrates 101 and 102.

[0177] Table 5 shows the volumetric content of the solid components of the sealant paste, its bonding conditions, and the improvement rate of bond strength of the resulting joints. It should be noted that the improvement rate of bond strength for joints A-05a~A-05c, A-17a~A-17c, A-33a~A-33c, and A-40a~A-40c is based on the average bond strength of joints made using a sealant paste containing lead-free low-melting-point glass G-05, G-17, G-33, or G-40 and low-thermal-expansion filler particles F-01, as a comparative example where the solid components do not contain spherical glass beads. The volumetric content of the lead-free low-melting-point glass and the low-thermal-expansion filler particles was determined taking into account the thermal expansion of the soda-lime glass used in the glass substrates 101 and 102.

[0178] Table 5

[0179]

[0180] Among all the joints A-05a~A-05c, A-17a~A-17c, A-33a~A-33c, and A-40a~A-40c, assuming the same type of lead-free low-melting-point glass, the presence of soda-lime glass spherical beads B-14 has the greatest effect on improving the bonding strength. The presence of borosilicate glass spherical beads B-21 also contributes to the bonding effect.

[0181] Regarding the presence of quartz glass spherical beads B-31, almost no effect on strength improvement was observed in joints A-5c and A-17c. Furthermore, in joints A-33c and A-40c, the result was a decrease in joint strength.

[0182] To investigate the cause, the cross-section of the joint before the bonding strength test was observed using an electron microscope. The results showed that cracks had already formed in the lead-free low-melting-point glass near the interface of the quartz glass spherical beads B-31 after bonding. This was attributed to the very small thermal expansion of the quartz glass spherical beads B-31, which contrasted sharply with the large difference in thermal expansion between the beads and the lead-free low-melting-point glass, thus leading to the cracking.

[0183] When the particle size is very small, such as that of low thermal expansion filler particles, the generation of such cracks cannot be detected. Therefore, when introducing spherical glass beads, it is necessary to consider not only the thermal expansion of the glass substrates 101 and 102 as the bonding materials, but also the difference in thermal expansion between them and the spherical glass beads.

[0184] Based on the above, the spherical glass beads in the sealant paste are made of the same glass-based raw material as the glass substrates 101 and 102, which is most effective for improving the bonding strength of the joint. Secondly, it is known that similar glass-based raw materials also have the effect of improving bonding strength. This is based on the compatibility (integration) of the thermal expansion of the glass substrates 101 and 102 with that of the spherical glass beads. Furthermore, it suggests that setting the coefficient of thermal expansion of the spherical glass beads in the sealant paste relative to the coefficient of thermal expansion of the glass substrates 101 and 102 to ±15 × 10⁻⁶ is appropriate. -7 The results are effective within a range of / ℃. Clearly, the results of this embodiment can be effectively applied to the low-temperature hermetically sealed application of vacuum-insulated multilayer glass.

[0185] [Example 5]

[0186] In this embodiment, based on the discussion results of Examples 1 to 4 above, a sealing material paste containing lead-free low-melting-point glass (Table 1), low thermal expansion filler particles (Table 2), and spherical glass beads (Table 3) is used to prepare... Figure 1A The vacuum-insulated multilayer glass panel of the present invention was shown, and its heat insulation and reliability were evaluated. Additionally, as a comparative example, a vacuum-insulated multilayer glass panel as shown in FIG1 was fabricated using a sealing material paste that does not contain the spherical glass beads listed in Table 3, in the same manner as described above, and its heat insulation and reliability were evaluated. The comparative example is used for comparison with the vacuum-insulated multilayer glass panel of this embodiment. It should be noted that both this embodiment and the comparative example are based on... Figures 3A-7B The manufacturing method of the vacuum-insulated multilayer glass panel shown and Figure 8A and 8B The temperature distribution shown was used to fabricate a vacuum-insulated multilayer glass panel.

[0187] In the vacuum-insulated multilayer glass panel of this embodiment and its comparative examples, a 300×300×3mm soda-lime glass substrate is used for the first glass substrate 1 and the second glass substrate 2, and a metal spacer (made of stainless steel) with a height of 200μm and an outer diameter of 500μm is used for the spacer 3. The sealing material paste used in this embodiment contains lead-free low-melting-point glass G-08 from Table 1, low thermal expansion filler particles F-01 from Table 2, and spherical glass beads B-13 from Table 3 as solid components. The respective volume contents of these solid components are 48:27:25 (volume %).

[0188] In addition, the sealing paste used in the comparative example contained lead-free low-melting-point glass G-08 from Table 1 and low thermal expansion filler particles F-01 from Table 2 as solid components. The respective volume content of these solid components was 64:36 (volume %). The content ratio of lead-free low-melting-point glass G-08 and low thermal expansion filler particles F-01 in the comparative example was the same as that in this embodiment.

[0189] Regarding the thermal insulation properties of the vacuum-insulated multilayer glass panels of this embodiment and its comparative examples, the heat transfer coefficient is 0.7 W / m. 2 A value around K is considered good.

[0190] Figure 15 This illustrates a test apparatus used to evaluate the reliability of vacuum-insulated multilayer glass panels.

[0191] The test apparatus shown in this figure has a configuration in which a vacuum-insulated multilayer glass panel is placed within a quadrilateral fluoropolymer container 19 (made of PTFE, polytetrafluoroethylene, etc.) via a silicone rubber gasket 20, enabling testing. A hot air blower and a cold air blower are installed outside the fluoropolymer container 19. Two types of air at significantly different temperatures can be introduced into the fluoropolymer container 19 from either of these via a φ10mm fluoropolymer pipe 21 (made of PTFE, etc.). The air temperature can be switched using an automatic on / off valve.

[0192] Regarding the vacuum-insulated multilayer glass panel of this embodiment and its comparative example, hot air at 80°C and cold air at -50°C were alternately blown onto the panel at a flow rate of 30 L / min for 15 minutes. One cycle was defined as each instance of hot and cold air being blown, and this was repeated 1000 times. Then, after 1000 cycles, the heat transfer coefficient was measured, etc., to evaluate the damage condition of the sealing portion.

[0193] After the above cycle, in the comparative example of the vacuum-insulated multilayer glass panel, the seal appeared undamaged, but there was a leak somewhere, resulting in a complete lack of insulation. However, in the embodiment of the vacuum-insulated multilayer glass panel, the initial insulation performance was maintained, confirming that the seal was not damaged. This demonstrates that introducing the spherical glass beads into the seal is effective.

[0194] [Example 6]

[0195] In this embodiment, instead of the lead-free low-melting-point glass G-08 in Table 1 of the solid composition of Example 5, lead-free low-melting-point glass G-12 in Table 1 was used. Other components of the solid composition are the low thermal expansion filler particles F-01 in Table 2 and the spherical glass beads B-13 in Table 3. A sealant paste containing these solid components was prepared. Figure 1A The vacuum-insulated multilayer glass panel of the present invention, as shown, was evaluated for its thermal insulation and reliability. Additionally, as a comparative example, a sealing material paste, excluding the spherical glass beads in Table 3, was used to prepare the panel. Figure 1A The vacuum-insulated multilayer glass panel shown was evaluated for its thermal insulation and reliability. Comparative examples are provided for comparison with the vacuum-insulated multilayer glass panel of this embodiment.

[0196] Furthermore, the difference between this embodiment and Comparative Example 5 in the vacuum-insulated multilayer glass panel is that a spacer made of polyimide resin with a height of 200 μm and an outer diameter of 500 μm is used in spacer 3 of this embodiment. In spacer 3 of the Comparative Example, a metal spacer (made of stainless steel) of the same shape is used, similar to that in Example 5.

[0197] In this embodiment, the volume percentages of lead-free low-melting-point glass G-12, low-thermal-expansion filler particles F-01, and spherical glass beads B-13 in the solid components of the sealant paste are 46:29:25 (volume %). In contrast, the volume percentages of lead-free low-melting-point glass G-12 and low-thermal-expansion filler particles F-01 in the sealant paste used in the comparative example are 61:39 (volume %). The content ratios of lead-free low-melting-point glass G-12 and low-thermal-expansion filler particles F-01 in the comparative example are the same as in this embodiment.

[0198] Regarding the thermal insulation performance of the vacuum-insulated multilayer glass panels of this embodiment and its comparative example, the thermal transfer coefficient of the comparative example is 0.7 W / m. 2 The K value is around 0.5 W / m², while in this embodiment it is 0.5 W / m². 2 The thermal insulation performance is approximately K. That is, the vacuum-insulated multilayer glass panel of this embodiment exhibits superior thermal insulation compared to the vacuum-insulated multilayer glass panel of the comparative example. This is believed to be due to the use of a resin with a significantly lower thermal conductivity than metal in the spacer 3.

[0199] The reliability of the vacuum-insulated multilayer glass panels of the embodiments and comparative examples was evaluated in the same manner as in Example 5.

[0200] After undergoing the same cycle as in Example 5, in the comparative example's vacuum-insulated multilayer glass panel, the seal appeared undamaged, but leakage occurred, resulting in a significant deterioration in insulation performance. However, in the vacuum-insulated multilayer glass panel of this embodiment, the initial insulation performance was maintained, confirming that the seal was not damaged. This demonstrates that introducing the spherical glass beads into the seal is effective. Furthermore, the effectiveness of the resin spacer was confirmed.

[0201] [Example 7]

[0202] In this embodiment, instead of the lead-free low-melting-point glass G-08 in Table 1 and the spherical glass beads B-13 in Table 3 of the solid composition of Example 5, lead-free low-melting-point glass G-24 in Table 1 and spherical glass beads B-12 in Table 3 were used. Other components of the solid composition are the low thermal expansion filler particles F-01 in Table 2. A sealant paste containing these solid components is used to prepare... Figure 1A The vacuum-insulated multilayer glass panel of the present invention, as shown, was evaluated for its thermal insulation and reliability. Additionally, as a comparative example, a sealing material paste, excluding the spherical glass beads in Table 3, was used to prepare the panel. Figure 1A The vacuum-insulated multilayer glass panel shown was evaluated for its thermal insulation and reliability. Comparative examples are provided for comparison with the vacuum-insulated multilayer glass panel of this embodiment.

[0203] Furthermore, the differences between this embodiment and its comparative examples of vacuum-insulated multilayer glass panels and those of Example 5 are that an air-cooled strengthened soda-lime glass substrate is used for the first glass substrate 1 and the second glass substrate 2, and a spacer made of polyamide resin with a height of 150 μm and an outer diameter of 300 μm is used for the spacer 3 in this embodiment. In the spacer 3 of the comparative example, a metal spacer (made of stainless steel) with the same shape as that in this embodiment is used.

[0204] In this embodiment, the volume percentages of lead-free low-melting-point glass G-24, low-thermal-expansion filler particles F-01, and spherical glass beads B-12 in the solid components of the sealant paste are 46:34:20 (volume %). In contrast, the volume percentages of lead-free low-melting-point glass G-24 and low-thermal-expansion filler particles F-01 in the sealant paste used in the comparative example are 57:43 (volume %). The content ratios of lead-free low-melting-point glass G-12 and low-thermal-expansion filler particles F-01 in the comparative example are the same as in this embodiment.

[0205] Regarding the thermal insulation performance of the vacuum-insulated multilayer glass panels of this embodiment and its comparative example, the thermal transfer coefficient of the comparative example is 0.8 W / m. 2 The K value is approximately 0.6 W / m², while in this embodiment it is 0.6 W / m². 2The thermal insulation performance is approximately K. That is, the vacuum-insulated multilayer glass panel of this embodiment exhibits superior thermal insulation compared to the vacuum-insulated multilayer glass panel of the comparative example. This is believed to be due to the use of a resin with a significantly lower thermal conductivity than metal in the spacer 3.

[0206] The reliability of the vacuum-insulated multilayer glass panels of the embodiments and comparative examples was evaluated in the same manner as in Example 5.

[0207] After undergoing the same cycle as in Example 5, in the comparative example's vacuum-insulated multilayer glass panel, peeling was visually observed at the sealing portion, indicating a significant deterioration in thermal insulation. However, in the vacuum-insulated multilayer glass panel of this embodiment, the initial thermal insulation performance was maintained, confirming that the sealing portion remained intact. This demonstrates that introducing the spherical glass beads into the sealing portion is effective. Furthermore, the effectiveness of the resin spacer was confirmed. Therefore, it can be seen that air-cooled tempered glass can be effectively applied to glass substrates.

[0208] [Example 8]

[0209] In this embodiment, instead of the lead-free low-melting-point glass G-08 in Table 1 and the spherical glass beads B-13 in Table 3 of the solid composition of Example 5, lead-free low-melting-point glass G-25 in Table 1 and spherical glass beads B-15 in Table 3 were used. Other components of the solid composition are the low thermal expansion filler particles F-01 in Table 2. A sealant paste containing these solid components was prepared. Figure 1A The vacuum-insulated multilayer glass panel of the present invention, as shown, was evaluated for its thermal insulation and reliability. Additionally, as a comparative example, a sealing material paste, excluding the spherical glass beads in Table 3, was used to prepare the panel. Figure 1A The vacuum-insulated multilayer glass panel shown was evaluated for its thermal insulation and reliability. Comparative examples are provided for comparison with the vacuum-insulated multilayer glass panel of this embodiment.

[0210] Furthermore, the differences between this embodiment and Comparative Example 5 in the vacuum-insulated multilayer glass panel are as follows: a chemically strengthened soda-lime glass substrate is used for the first glass substrate 1 and the second glass substrate 2; and a spacer made of fluororesin containing ceramic particles, with a height of 250 μm and an outer diameter of 500 μm, is used for spacer 3 in this embodiment. Here, the ceramic particles are Al2O3 particles. To prevent deformation of the resin spacer during airtight sealing, the ceramic particles are dispersed within the resin spacer. In the spacer 3 of the Comparative Example, a metal spacer (made of stainless steel) with the same shape as in this embodiment is used.

[0211] In this embodiment, the volume percentage of lead-free low-melting-point glass G-25, low-thermal-expansion filler particles F-01, and spherical glass beads B-15 in the solid components of the sealant paste is 40:30:30 (volume %). In contrast, the volume percentage of lead-free low-melting-point glass G-25 and low-thermal-expansion filler particles F-01 in the sealant paste used in the comparative example is 57:43 (volume %). The content ratio of lead-free low-melting-point glass G-25 and low-thermal-expansion filler particles F-01 in the comparative example is the same as that in this embodiment.

[0212] Regarding the thermal insulation performance of the vacuum-insulated multilayer glass panels of this embodiment and its comparative example, the thermal transfer coefficient of the comparative example is 0.7 W / m. 2 The K value is around 0.4 W / m², while in this embodiment it is 0.4 W / m². 2 The thermal insulation performance is approximately K. That is, the vacuum-insulated multilayer glass panel of this embodiment exhibits superior thermal insulation compared to the vacuum-insulated multilayer glass panel of the comparative example. This is believed to be due to the use of a resin with a significantly lower thermal conductivity than metal in the spacer 3.

[0213] In the comparative example of the vacuum-insulated multilayer glass panel, several areas of peeling were observed in the sealing portion, resulting in a significant deterioration in thermal insulation. However, in the vacuum-insulated multilayer glass panel of the embodiment, the initial thermal insulation performance was maintained, confirming that the sealing portion remained intact. This demonstrates that introducing spherical glass beads into the sealing portion is effective. Furthermore, the effectiveness of the resin spacer with dispersed ceramic particles was confirmed. Therefore, it can be seen that chemically strengthened glass can be effectively applied to glass substrates.

[0214] [Example 9]

[0215] In this embodiment, instead of the lead-free low-melting-point glass G-08 in Table 1 of the solid composition of Example 5, lead-free low-melting-point glass G-22 in Table 1 was used. Other components of the solid composition are the low thermal expansion filler particles F-01 in Table 2 and the spherical glass beads B-13 in Table 3. Two types of sealant pastes containing these solid components were produced by changing the material of the spacer 3. Figure 1A The vacuum-insulated multilayer glass panel of the present invention, as shown, was evaluated for its thermal insulation and reliability. Additionally, as a comparative example, a sealing material paste, excluding the spherical glass beads in Table 3, was prepared using the solid components of Example 5. Figure 1A The vacuum-insulated multilayer glass panel shown was evaluated for its thermal insulation and reliability. Comparative examples are provided for comparison with the vacuum-insulated multilayer glass panel of this embodiment.

[0216] Furthermore, the difference between this embodiment and Comparative Example 5 in the vacuum-insulated multilayer glass panel is that two types of spacers, one made of epoxy resin containing glass particles and the other of phenoxy resin containing glass particles, with a height of 200 μm and an outer diameter of 500 μm, are used in spacer 3 of this embodiment. Here, the glass particles are SiO2 particles. To prevent the resin spacer from deforming during airtight sealing, the glass particles are dispersed within the resin spacer. In spacer 3 of the Comparative Example, a metal spacer (made of stainless steel) with the same shape as in this embodiment is used.

[0217] In this embodiment, the volume percentages of lead-free low-melting-point glass G-22, low-thermal-expansion filler particles F-01, and spherical glass beads B-13 in the solid components of the sealant paste are 42:38:20 (volume %). In contrast, the volume percentages of lead-free low-melting-point glass G-22 and low-thermal-expansion filler particles F-01 in the sealant paste used in the comparative example are 53:47 (volume %). The content ratios of lead-free low-melting-point glass G-22 and low-thermal-expansion filler particles F-01 in the comparative example are the same as in this embodiment.

[0218] Regarding the thermal insulation performance of the vacuum-insulated multilayer glass panels of this embodiment and its comparative example, the thermal transfer coefficient of the comparative example is 0.8 W / m. 2 The K value is around 0.5 W / m², while in this embodiment, both are 0.5 W / m². 2 The thermal insulation performance is approximately K. That is, the vacuum-insulated multilayer glass panel of this embodiment exhibits superior thermal insulation compared to the vacuum-insulated multilayer glass panel of the comparative example. This is believed to be due to the use of a resin with a significantly lower thermal conductivity than metal in the spacer 3.

[0219] In the comparative example of the vacuum-insulated multilayer glass panel, several areas of peeling were observed in the sealing portion, resulting in a significant deterioration in thermal insulation. However, in the vacuum-insulated multilayer glass panel of the embodiment, the initial thermal insulation performance was maintained, confirming that the sealing portion was not damaged. This demonstrates that introducing spherical glass beads into the sealing portion is effective. Furthermore, the effectiveness of the resin spacer with dispersed glass particles was confirmed.

[0220] [Example 10]

[0221] In this embodiment, instead of the lead-free low-melting-point glass G-08 in Table 1 of the solid composition of Example 5, lead-free low-melting-point glass G-42 in Table 1 was used. Other components of the solid composition are the low thermal expansion filler particles F-01 in Table 2 and the spherical glass beads B-13 in Table 3. A sealant paste containing these solid components was prepared. Figure 1AThe vacuum-insulated multilayer glass panel of the present invention, as shown, was evaluated for its thermal insulation and reliability. Additionally, as a comparative example, a sealing material paste, excluding the spherical glass beads in Table 3, was used to prepare the panel. Figure 1A The vacuum-insulated multilayer glass panel shown was evaluated for its thermal insulation and reliability. Comparative examples are provided for comparison with the vacuum-insulated multilayer glass panel of this embodiment.

[0222] Furthermore, the differences between this embodiment and Comparative Example 5 in the vacuum-insulated multilayer glass panel are as follows: an air-cooled strengthened soda-lime glass substrate is used for the first glass substrate 1 and the second glass substrate 2; and a spacer made of silicone resin containing glass particles, with a height of 200 μm and an outer diameter of 500 μm, is used for the spacer 3 in this embodiment. Here, the glass particles are SiO2 particles. To prevent deformation of the resin spacer during airtight sealing, the glass particles are dispersed within the resin spacer. In the spacer 3 of the Comparative Example, a metal spacer (made of stainless steel) with the same shape as in this embodiment is used.

[0223] In this embodiment, the volume percentages of lead-free low-melting-point glass G-42, low-thermal-expansion filler particles F-01, and spherical glass beads B-13 in the solid components of the sealant paste are 43:32:25 (volume %). In contrast, the volume percentages of lead-free low-melting-point glass G-42 and low-thermal-expansion filler particles F-01 in the sealant paste used in the comparative example are 57:43 (volume %). The content ratios of lead-free low-melting-point glass G-42 and low-thermal-expansion filler particles F-01 in the comparative example are the same as in this embodiment.

[0224] Regarding the thermal insulation performance of the vacuum-insulated multilayer glass panels of this embodiment and its comparative example, the thermal transfer coefficient of the comparative example is 0.7 W / m. 2 The K value is around 0.4 W / m², while in this embodiment, both are 0.4 W / m². 2 The thermal insulation performance is approximately K. That is, the vacuum-insulated multilayer glass panel of this embodiment exhibits superior thermal insulation compared to the vacuum-insulated multilayer glass panel of the comparative example. This is believed to be due to the use of a resin with a significantly lower thermal conductivity than metal in the spacer 3.

[0225] In the comparative example of the vacuum-insulated multilayer glass panel, peeling was visually observed at the sealing portion, indicating a significant deterioration in thermal insulation. However, in the embodiment of the vacuum-insulated multilayer glass panel, the initial thermal insulation performance was maintained, confirming that the sealing portion remained intact. This demonstrates that introducing spherical glass beads into the sealing portion is effective. Furthermore, the effectiveness of the resin spacer with dispersed glass particles was confirmed. Therefore, it is evident that air-cooled tempered glass can be effectively applied to glass substrates.

[0226] According to Examples 1 to 10 above, the vacuum-insulated multilayer glass panel of the present invention can achieve an airtight seal at low temperatures, thus exhibiting excellent mass production capabilities. Furthermore, a resin with low thermal conductivity can be used as a spacer, resulting in excellent thermal insulation. Moreover, since the bonding strength of the sealing portion can be improved, reliability is also excellent. These advantages of mass production capability, thermal insulation, and reliability can be achieved using the sealing material paste of the present invention.

[0227] Therefore, the vacuum-insulated multilayer glass panel of the present invention, which utilizes the sealing material paste of the present invention, can be widely adopted in the residential and building sectors worldwide, and can significantly contribute to addressing global warming by reducing CO2 emissions through energy consumption reduction.

[0228] Explanation of reference numerals in the attached figures

[0229] 1: First glass substrate; 2: Second glass substrate; 3: Spacer; 4: Sealing part; 5: Internal space; 6: Heat radiation reflective film; 7: Low melting point glass; 8: Low thermal expansion filler particles; 9: Glass beads; 10: Vent hole; 11: Vent pipe; 12: Distributor; 13: Sealing material paste; 14: Sealing material; 15: Heat-resistant clamp; 16: Vacuum exhaust furnace; 17: Electric heater; 18: Vacuum pump; 19: Fluoropolymer container; 20: Silicone rubber gasket; 21: Fluoropolymer tube; 51: Shearing clamp; 52: Joint fixing clamp; 101, 102: Glass substrate.

Claims

1. A sealing material for multilayer glass panels, comprising: lead-free low-melting-point glass particles containing vanadium oxide and tellurium oxide, low thermal expansion filler particles, and glass beads as a solid component. The volume content of the glass beads in the solid component is more than 10% and less than 35%. The volume fraction of the lead-free low-melting-point glass particles in the solid composition is greater than the volume fraction of the low thermal expansion filler particles in the solid composition. The low thermal expansion filler particles are formed from zirconium tungstate phosphate. The glass beads are formed of soda-lime glass or borosilicate glass. The average diameter D of the glass bead 50 The size is between 50μm and 200μm. The average particle size D of the low thermal expansion filler particles 50 It is between 3μm and 20μm.

2. The sealing material for multilayer glass panels according to claim 1, wherein, The volume content of the glass beads in the solid component is more than 20% and less than 30%.

3. The sealing material for multilayer glass panels according to claim 1, wherein, The volume content of the lead-free low-melting-point glass particles in the solid component is more than 35%.

4. The sealing material for multilayer glass panels according to claim 1, wherein, The lead-free low-melting-point glass particles further contain silver oxide.

5. The sealing material for multilayer glass panels according to claim 1, wherein, The lead-free low-melting-point glass particles further comprise one or more of tungsten oxide, barium oxide, potassium oxide, and phosphorus oxide.

6. The sealing material for multilayer glass panels according to claim 1, wherein, The lead-free low-melting-point glass particles further comprise one or more of aluminum oxide, iron oxide, yttrium oxide, and lanthanum oxide.

7. The sealing material for multilayer glass panels according to claim 1, further comprising a solvent and an adhesive resin.

8. The sealing material for multilayer glass panels according to claim 7, wherein, The adhesive resin comprises one or more of ethyl cellulose, nitrocellulose, and aliphatic polycarbonate.

9. The sealing material for multilayer glass panels according to claim 7, wherein, The solvent comprises one or more of butyl carbitol acetate, terpene solvents, and propylene carbonate.

10. A multilayer glass panel comprising: a first glass substrate, a second glass substrate disposed opposite to the first glass substrate at a predetermined distance, a spacer sandwiched between the first glass substrate and the second glass substrate to maintain the distance, and a sealing portion sandwiched between the first glass substrate and the second glass substrate. It has an internal space surrounded by the first glass substrate, the second glass substrate, and the sealing portion, and the spacer is disposed in the internal space. The sealing portion comprises the sealing material for multilayer glass panels as described in any one of claims 1 to 9.

11. The multilayer glass panel of claim 10, wherein, The maximum diameter of the glass beads is below the specified spacing, and the average diameter D of the glass beads is... 50 It is more than half of the aforementioned spacing.

12. The multilayer glass panel of claim 10, wherein, The coefficient of thermal expansion of the glass bead relative to the coefficient of thermal expansion of the first glass substrate or the second glass substrate is within ±15×10. -7 Within the range of / ℃.

13. The multilayer glass panel of claim 10, wherein, The spacer comprises resin.

14. The multilayer glass panel of claim 13, wherein, The resin comprises one or more of polyimide resin, polyamide resin, fluororesin, epoxy resin, phenoxy resin, and silicone resin.

15. The multilayer glass panel of claim 13, wherein, The spacer comprises glass particles or ceramic particles.

16. The multilayer glass panel of claim 10, wherein, The first glass substrate or the second glass substrate is formed of reinforced glass that has undergone air-cooling strengthening treatment or chemical strengthening treatment.

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