Multilayer insulating glass and preparation method thereof

Abstract

The present invention relates to the field of glass technology, specifically to a multi-layer insulating glass and a preparation method thereof. The present invention overcomes the problems of poor thermal insulation and durability of ordinary glass. The present invention improves the durability of the glass by changing the proportion of borosilicate glass components, ultrasonically cleaning the borosilicate glass, and then exchanging ions with potassium nitrate molten salt and sodium nitrate molten salt; preparing a composite insulating coating slurry by nano-silicon carbide, nano-zirconium dioxide and nano-titanium dioxide particles, and using an electrostatic spraying process to attach it to the surface of a pretreated substrate to improve the thermal insulation performance of the glass; obtaining an aerogel interlayer by mixing silica sol and polyvinyl pyrrolidone and then spin-coating it on the outer surface of the pretreated substrate to improve the thermal insulation performance of the glass; and forming a stable chemical bond connection at the interface through a low-temperature sintering bonding process reinforced by nano-zirconium oxide, which greatly improves the durability of the glass.

Description

Technical Field

[0001] The present invention relates to the technical field of glass, in particular to a multi-layer heat-insulating glass and a preparation method thereof. Background Art

[0002] Glass products are widely used in home life, and glass tea sets are deeply loved by tea lovers. However, traditional glass tea sets have obvious shortcomings in thermal insulation performance: when people brew hot tea, ordinary single-layer glass tea sets conduct heat quickly, causing the outer wall temperature to be too high, which not only easily burns the user's hands, but also causes the heat of the tea soup to dissipate quickly, making it difficult to maintain a suitable drinking temperature for a long time, affecting the full release of the tea aroma and the taste experience; although double-layer glass tea sets have improved the thermal insulation to a certain extent, the effect is still unsatisfactory, especially in cold seasons or after being placed for a long time, the temperature of the tea soup drops rapidly. In addition, from the perspective of durability, glass tea sets are used frequently in households. Traditional glass tea sets are prone to cracking due to thermal expansion and contraction during the frequent alternation of hot and cold in daily life. Their preparation process is complex and requires delicate operations to ensure the sealing and uniformity of the glass, which increases costs and unstable product quality. Ordinary families often have concerns when choosing. Therefore, developing a multi-layer insulating glass with excellent thermal insulation and durability is of great significance to improving household glass tea sets and enhancing the quality of family life.

[0003] Therefore, a multi-layer heat-insulating glass and a preparation method thereof are proposed. Summary of the Invention

[0004] The object of the present invention is to provide a multi-layer insulating glass and a preparation method thereof. By changing the proportion of borosilicate glass components, the borosilicate glass is ultrasonically cleaned and then ion-exchanged with potassium nitrate molten salt and sodium nitrate molten salt to improve the durability of the glass; a composite insulating coating slurry is prepared by nano-silicon carbide, nano-zirconium dioxide and nano-titanium dioxide particles, and an electrostatic spraying process is used to attach it to the surface of a pretreated substrate to improve the thermal insulation performance of the glass; an aerogel interlayer is obtained by mixing silica sol and polyvinyl pyrrolidone and then spin-coating it on the outer surface of the pretreated substrate to improve the thermal insulation performance of the glass; and a stable chemical bond connection is formed at the interface through a low-temperature sintering bonding process strengthened by nano-zirconium oxide, thereby greatly improving the durability of the glass.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] In one aspect, the present invention provides a method for preparing multi-layer insulating glass. The method comprises: subjecting a substrate to ion exchange with potassium nitrate molten salt and sodium nitrate molten salt to obtain a pretreated substrate; coating the inner surface of the pretreated substrate with a composite insulating coating; mixing silica sol and polyvinyl pyrrolidone and then spin-coating the mixture on the outer surface of the pretreated substrate to form an aerogel interlayer; and finally coating with a bonding slurry and sintering the mixture to obtain the multi-layer insulating glass.

[0007] The composite thermal insulation coating is prepared from nano-silicon carbide, nano-zirconium dioxide and nano-titanium dioxide particles;

[0008] The bonding slurry is prepared from aluminum silicate sol and nano zirconium oxide.

[0009] Preferably, the method for preparing the pretreated substrate is as follows: borosilicate glass is ultrasonically cleaned with acetone and deionized water in sequence and dried to obtain a glass blank; a potassium nitrate molten salt bath is heated to 440-460° C., and the glass blank is immersed therein for treatment for 60 minutes; then, the glass blank is transferred to a sodium nitrate molten salt bath, treated at 495-515° C. for 30 minutes, and then washed with deionized water and dried to obtain a pretreated substrate.

[0010] Preferably, the borosilicate glass comprises 75-85 wt% silicon dioxide, 8-12 wt% boron trioxide and 2-5 wt% aluminum oxide.

[0011] Preferably, the preparation method of the composite thermal insulation coating is as follows: nano silicon carbide and nano zirconium dioxide are added to a ball mill in a mass ratio of 12:8, ball milled for 4-6 hours, then added to xylene, and 0.5 parts of silane coupling agent KH560 are added, and ultrasonic dispersion is performed for 40 minutes to obtain a suspension; 1-3 parts of nano titanium dioxide particles are added to the suspension and ultrasonicated again for 25 minutes to obtain a slurry; a high-voltage electrostatic generator is used to make the slurry sprayed from the spray gun adhere to the surface of the pretreated substrate to obtain a composite thermal insulation coating, the distance between the spray gun and the pretreated substrate is 15-20 cm, and the spraying pressure is 0.3-0.4 MPa.

[0012] Preferably, the aerogel interlayer preparation method is as follows: silica sol and polyvinyl pyrrolidone are mixed in a mass ratio of 1:0.5-2, and ultrasonically formed into a composite sol; using a spin coating process, the composite sol is spin-coated onto the surface of a pretreated substrate at a speed of 2000-4000 rpm to form a wet film, and the film is allowed to stand at room temperature for 2 hours to obtain a gel film; the gel film is placed in a supercritical drying device, liquid CO2 is injected, the temperature is raised to 40°C, the pressure is increased to 7-15 MPa and maintained for 4 hours, and the pressure is released to obtain the aerogel interlayer.

[0013] Preferably, the bonding slurry is prepared as follows: aluminum silicate sol and nano zirconium oxide are mixed in a mass ratio of 7:1.5-5, and 2 wt% of the total amount of aluminum silicate sol and nano zirconium oxide as a rheological additive polyethylene oxide is added, and ball milling is performed for 4 hours to obtain the bonding slurry.

[0014] Preferably, the sintering steps are as follows: using a slit coater to apply the adhesive slurry to the edge bonding area of ​​the aerogel interlayer and then placing it on a fixture for prepolymerization; then, under a nitrogen atmosphere, heating to 300-500°C at 5°C / min, keeping warm for 30 minutes, and cooling to room temperature to obtain multi-layer insulating glass.

[0015] Another aspect of the present invention provides a multi-layer insulating glass, which is composed of a pretreated substrate, a composite insulating coating, an aerogel interlayer and an adhesive slurry; the multi-layer insulating glass is prepared by any of the above preparation methods.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. The present invention treats the glass blank in a potassium nitrate molten salt bath to reduce the Na + K in molten salt + The initial compressive stress layer is formed by replacement, and then a secondary exchange treatment is carried out in a sodium nitrate molten salt bath to balance the deep stress distribution and generate a gradient compressive stress layer. This ion exchange process significantly improves the strength and thermal shock resistance of the glass, effectively reducing the risk of breakage caused by collisions and alternating hot and cold temperatures in daily use, greatly improving the durability of the glass and extending its service life.

[0018] 2. The present invention prepares a composite thermal insulation coating, and the composite matrix of nano-silicon carbide and zirconium dioxide forms a dense nano-network, which effectively blocks the solid-phase heat transfer path and reduces the radiation heat transfer coefficient of the glass; the introduction of titanium dioxide enhances the reflection ability of infrared radiation and significantly reduces the proportion of radiation heat transfer; the electrostatic spraying process is used to make the nanoparticles directionally enriched on the surface of the substrate to form a continuous and uniform structure, avoiding the thermal bridge effect caused by coating gaps; the silane coupling agent strengthens the bonding strength between the nanoparticles and the glass interface, ensuring that the coating maintains structural integrity during thermal cycles and improving the thermal insulation performance of the glass.

[0019] 3. The present invention utilizes an aerogel interlayer, which exhibits extremely low thermal conductivity and effectively blocks heat conduction. After the components of the aerogel interlayer are left to stand at room temperature to form a gel film, they are then subjected to supercritical drying, preserving their internal pore structure. This significantly reduces air convection and conduction, further lowering thermal conductivity. This aerogel interlayer forms a highly effective thermal insulation barrier on the outer surface of the glass, synergizing with the composite thermal insulation coating on the inner layer to significantly enhance the overall thermal insulation performance of the glass, effectively reducing heat loss and transfer.

[0020] 4. The present invention uses a low-temperature sintering bonding process based on nano-zirconia reinforcement to form a stable chemical bond at the interface, significantly improving interlayer bonding and high-temperature aging resistance. The nanoparticles in the bonding layer fill micro-gaps and resist moisture penetration, preventing delamination of the interface due to water vapor erosion during long-term use. The composite structure maintains excellent stability in high-temperature and high-humidity environments (such as cooking and steam sterilization). The strong bond between the coating and the substrate also enhances the overall impact resistance. Even special-shaped tea sets (such as curved teapots) can withstand daily bumps and mechanical stress, greatly improving their durability. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a graph showing the thermal insulation performance test results of Example 3, Examples 5-7, and Comparative Examples 5-8 of the present invention. DETAILED DESCRIPTION

[0022] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0023] See also Figure 1 The present invention provides a multi-layer insulating glass and a preparation method thereof, and the technical solution is as follows:

[0024] The substance information involved in the present invention is as follows:

[0025] Acetone (CAS: 67-64-1); silicon dioxide (CAS: 14808-60-7); boron trioxide (CAS: 1303-86-2); aluminum oxide (CAS: 1344-28-1); nano-silicon carbide (CAS: 409-21-2); xylene (CAS: 1330-20-7); silane coupling agent KH560 (CAS: 2530-83-8); polyvinyl pyrrolidone (CAS: 9003-39-8); nano-zirconium oxide (CAS: 1314-23-4); molten salt-grade potassium nitrate and molten salt-grade sodium nitrate were purchased from Shandong Aobo Energy Storage Technology Co., Ltd.; nano-zirconium dioxide, nano-titanium dioxide, and silica sol were purchased from Xuancheng Jingrui New Materials Co., Ltd.; and aluminum silicate sol was purchased from Guangzhou Xinxi Metallurgical Chemical Co., Ltd.

[0026] Example 1

[0027] The borosilicate glass was ultrasonically cleaned with acetone and deionized water (frequency 40 kHz, time 10 minutes each) and dried to obtain a glass blank; a potassium nitrate molten salt bath was heated to 440°C and the glass blank was immersed in the bath for 60 minutes; the glass blank was then transferred to a sodium nitrate molten salt bath, treated at 495°C for 30 minutes, washed with deionized water, and dried to obtain a pretreated substrate; the borosilicate glass comprises 75 wt% silicon dioxide, 8 wt% boron trioxide, and 2 wt% aluminum oxide;

[0028] 12 parts of nano-silicon carbide (average particle size of 40 nm) and 8 parts of nano-zirconium dioxide (average particle size of 40 nm) were added to a ball mill and milled for 4 hours, then added to 38 parts of xylene, and 0.5 parts of silane coupling agent KH560 were added, and ultrasonic dispersion was performed for 40 minutes to obtain a suspension; 1 part of nano-titanium dioxide particles (average particle size of 30 nm) was added to the suspension and ultrasonicated again for 25 minutes to obtain a slurry; a high-voltage electrostatic generator was used to negatively charge the slurry droplets sprayed from the spray gun, and the pretreated substrate was positively charged by grounding. Under the action of electrostatic attraction, the slurry was evenly attached to the surface of the pretreated substrate to obtain a composite thermal insulation coating (thickness 1 μm), the distance between the spray gun and the pretreated substrate was 15 cm, and the spraying pressure was 0.3 MPa;

[0029] Silica sol and polyvinyl pyrrolidone were mixed in a mass ratio of 1:0.5 and treated with ultrasound (frequency 40 kHz, power 200 W) for 20 minutes to form a composite sol; the composite sol was spin-coated onto the surface of the pretreated substrate at a speed of 2000-4000 rpm using a spin coating process for 30 seconds to form a wet film, and the film was allowed to stand at room temperature for 2 hours to obtain a gel film; the gel film was placed in a supercritical drying device, liquid CO2 was injected to replace the ethanol in the pores, the temperature was raised to 40°C, the pressure was increased to 7 MPa and maintained for 4 hours, and the pressure was released to obtain an aerogel interlayer (thickness 100 μm);

[0030] Aluminum silicate sol (solid content 25%) and nano zirconium oxide (particle size 20 nm) were mixed in a mass ratio of 7:1.5, and a rheological additive polyethylene oxide (2 wt% of the total amount of aluminum silicate sol and nano zirconium oxide) was added, and the mixture was ball-milled for 4 hours to obtain a bonding slurry. The bonding slurry was applied to the edge bonding area of ​​the aerogel interlayer using a slit coater (gap height 100 μm) and then placed in a fixture for pre-polymerization (0.1 MPa). Then, under a nitrogen atmosphere, the temperature was raised to 300°C at 5°C / min, kept warm for 30 minutes, and cooled to room temperature to obtain multi-layer insulating glass.

[0031] Examples 2-4

[0032] Refer to the preparation method and parameter conditions of Example 1, the specific differences are shown in Table 1.

[0033] Table 1 Specific preparation parameters of Examples 2-4

[0034]

[0035] Comparative Example 1

[0036] The preparation method and parameter conditions are similar to those of Example 1, except that the borosilicate glass is not ultrasonically cleaned with acetone and deionized water in sequence.

[0037] Comparative Example 2

[0038] The preparation method and parameter conditions are the same as those in Example 1, except that the glass blank is not treated in a potassium nitrate molten salt bath.

[0039] Comparative Example 3

[0040] The preparation method and parameter conditions are the same as those in Example 1, except that the glass blank is not treated in a sodium nitrate molten salt bath.

[0041] Comparative Example 4

[0042] The preparation method and parameter conditions are similar to those of Example 1, except that no aluminum oxide is added to the borosilicate glass.

[0043] Experimental Example 1 Durability Test

[0044] The surface compressive stress is tested according to the standard GB / T 18144-2008;

[0045] Thermal shock test: The prepared glass was alternately immersed in 0°C ice water and 100°C boiling water 100 times to observe whether there were cracks or delamination; the results are shown in Table 2.

[0046] Table 2 Durability test of Example 4 and Comparative Examples 1-4

[0047] Example Surface compressive stress / MPa Thermal shock test Example 1 155 No cracks or delamination Example 2 156 No cracks or delamination Example 3 158 No cracks or delamination Example 4 155 No cracks or delamination Comparative Example 1 130 No cracks or delamination Comparative Example 2 112 Cracks appear Comparative Example 3 109 Cracks appear Comparative Example 4 124 Cracks appear

[0048] As can be seen from Table 1 and Table 2, in Examples 1-4, the borosilicate glass was ultrasonically cleaned and then treated in a potassium nitrate molten salt bath to replace the Na+ on the surface of the glass with the K+ in the molten salt to form a preliminary compressive stress layer, and then a secondary exchange treatment was performed in a sodium nitrate molten salt bath to balance the deep stress distribution and generate a gradient compressive stress layer. This ion exchange process improves the strength and thermal shock resistance of the glass, effectively reduces the risk of breakage caused by collisions and alternating hot and cold conditions in daily use, greatly improves the durability of the glass, and extends its service life. When the potassium nitrate molten salt bath temperature is 450°C and the sodium nitrate molten salt bath temperature is 505°C, and the borosilicate glass includes 82wt% silicon dioxide, 11wt% boron trioxide, and 4wt% aluminum oxide, the insulating glass obtained has the best durability, a surface compressive stress of 158MPa, and no cracks or delamination under hot and cold shock tests. In Comparative Example 1, the borosilicate glass was not ultrasonically cleaned with acetone and deionized water in sequence, and the contaminants caused uneven contact between the glass matrix and the molten salt, and K + with Na + The exchange is incomplete, the thickness of the compressive stress layer is reduced and unevenly distributed, and the local stress weak area increases. In Comparative Example 2, the glass blank was not treated with potassium nitrate molten salt bath, and the surface layer lacked dense K + The replacement layer results in a low overall compressive stress level, accelerated deep stress relaxation, and insufficient ability to inhibit crack propagation; the tensile strength of the glass matrix is ​​insufficient, and microcracks are easily formed when the surface is subjected to tensile stress during alternating hot and cold temperatures. In Comparative Example 3, the glass blank was not treated with a sodium nitrate molten salt bath, and no secondary Na + Backfilling balances deep stress gradients, increasing brittleness and reducing the glass matrix's resistance to mechanical impact. During rapid temperature changes, differential expansion at different depths causes stress release. In Comparative Example 4, alumina was not added to the borosilicate glass, reducing the stability of the glass network and weakening the density and interlocking ability of ion exchange active sites during molten salt treatment.

[0049] Examples 5-7

[0050] Referring to the preparation method and parameter conditions of Example 3, the specific differences are shown in Table 3; the ball milling time in Table 3 is the time for ball milling nano-silicon carbide and nano-zirconium dioxide when preparing the composite thermal insulation coating.

[0051] Comparative Example 5

[0052] The preparation method and parameter conditions are similar to those in Example 3, except that nano-silicon carbide is not added when preparing the composite thermal insulation coating.

[0053] Comparative Example 6

[0054] The preparation method and parameter conditions are similar to those of Example 3, except that nano zirconium dioxide is not added when preparing the composite thermal insulation coating.

[0055] Comparative Example 7

[0056] The preparation method and parameter conditions are similar to those in Example 3, except that nano-titanium dioxide is not added when preparing the composite thermal insulation coating.

[0057] Comparative Example 8

[0058] Refer to the preparation method and parameter conditions of Example 3, except that the composite thermal insulation coating is prepared without using an electrostatic spraying process, but directly sprayed with a spray gun.

[0059] Experimental Example 2 Thermal Insulation Performance Test

[0060] Refer to GB / T 38712-2020 standard test thermal conductivity;

[0061] Infrared isolation rate test method: Use a 150W Philips infrared halogen lamp as the light source, the test distance between the sample and the light source is 10cm, and use an LS122 infrared power meter to test the radiation power S0 and S1 before and after the sample glass is blocked. The infrared ray isolation rate was calculated; the results are shown in Table 3.

[0062] Table 3 Thermal insulation performance test of Example 3, Examples 5-7 and Comparative Examples 5-8

[0063]

[0064] From Table 3 and Figure 1 It can be seen that in Example 3 and Examples 5-7, by preparing a composite thermal insulation coating, a composite matrix of nano-silicon carbide and zirconium dioxide forms a dense nano-network, effectively blocking the solid-phase heat transfer path and reducing the radiation heat transfer coefficient of the glass; the introduction of titanium dioxide enhances the reflection ability of infrared radiation and significantly reduces the proportion of radiation heat transfer; an electrostatic spraying process is used to enrich the nanoparticles on the surface of the substrate in a direction, forming a continuous and uniform structure, avoiding the thermal bridge effect caused by coating gaps; the silane coupling agent strengthens the bonding strength between the nanoparticles and the glass interface, ensuring that the coating maintains structural integrity during thermal cycles and improving the thermal insulation performance of the glass. In Example 5, when the ball milling time is 5h, the amount of nano-titanium dioxide is 2 parts, the spray gun distance is 18cm, and the spraying pressure is 0.35MPa, the obtained glass has the best thermal insulation performance, with an infrared isolation rate of 98.2% and a thermal conductivity of 0.2W / m 2·K. In Comparative Example 5, nano silicon carbide was not added when preparing the composite thermal insulation coating, which cut off the phonon scattering network inside the coating, weakened the blocking ability of solid heat transfer, and partially lost its own optical reflection properties. In Comparative Example 6, nano zirconium dioxide was not added when preparing the composite thermal insulation coating. Zirconium dioxide serves as a low thermal conductivity skeleton. Its absence destroys the dense stacking structure between the nanoparticles, and at the same time loses the selective reflection effect on the mid- and far-infrared. The porosity of the particle stacking increases, and the proportion of gas convection heat transfer increases. In Comparative Example 7, nano titanium dioxide was not added when preparing the composite thermal insulation coating. Titanium dioxide has a high refractive index and wide-spectrum infrared reflection characteristics. Its absence causes the coating to lose its core reflection barrier to thermal radiation. In Comparative Example 8, the electrostatic spraying process was not used when preparing the composite thermal insulation coating. Instead, it was sprayed directly with a spray gun, resulting in disordered accumulation of particles and an island-like distribution of the coating microstructure, forming a heat conduction "short-circuit channel" and a fracture of the reflective interface.

[0065] Examples 8-10

[0066] Referring to the preparation method and parameter conditions of Example 5, the specific differences are shown in Table 4; the mass ratio of the two in Table 4 is the mass ratio of silica sol to polyvinyl pyrrolidone; and the pressure is the supercritical drying pressure when preparing the aerogel interlayer.

[0067] Comparative Example 9

[0068] The preparation method and parameter conditions were similar to those of Example 5, except that polyvinyl pyrrolidone was not added when preparing the aerogel interlayer.

[0069] Comparative Example 10

[0070] The preparation method and parameter conditions are similar to those of Example 5, except that the spin coating process is replaced by ordinary coating when preparing the aerogel interlayer.

[0071] Comparative Example 11

[0072] The preparation method and parameter conditions were similar to those in Example 5, except that supercritical drying was replaced by ordinary oven drying at 40° C. for 4 h during the preparation of the aerogel interlayer.

[0073] Comparative Example 12

[0074] The preparation method and parameter conditions are similar to those of Example 5, except that the prepared multi-layer insulating glass does not include an aerogel interlayer.

[0075] Comparative Example 13

[0076] The preparation method and parameter conditions are similar to those of Example 5, except that the prepared multi-layer insulating glass does not include a composite insulating layer.

[0077] Experimental Example 3 Thermal Insulation Performance Test

[0078] The thermal conductivity was tested according to GB / T 38712-2020. The results are shown in Table 4.

[0079] Table 4 Thermal insulation performance test of Example 5, Examples 8-10 and Comparative Examples 9-13

[0080] Example The quality ratio of the two Rotation speed / rpm Pressure / MPa <![CDATA[Thermal conductivity / (W / m 2 ·K)]]> Example 5 1：0.5 2000 7 0.20 Example 8 1：0.7 3000 10 0.16 Example 9 1：1.4 3500 12 0.21 Example 10 1：2 4000 15 0.25 Comparative Example 9 / 2000 7 0.24 Comparative Example 10 1：0.5 / 7 0.26 Comparative Example 11 1：0.5 2000 / 0.30 Comparative Example 12 / / / 0.42 Comparative Example 13 1：0.5 2000 7 0.43

[0081] As can be seen from Table 4, by preparing the aerogel interlayer, the aerogel has an extremely low thermal conductivity coefficient, which can effectively prevent heat conduction. After the components of the aerogel interlayer are left to stand at room temperature to form a gel film, they are subjected to supercritical drying treatment, and their internal pore structure is retained, which greatly reduces air convection and conduction, and further reduces thermal conductivity; the aerogel interlayer forms an efficient thermal insulation barrier on the outer surface of the glass, and synergizes with the composite thermal insulation coating of the inner layer to significantly improve the overall thermal insulation performance of the glass, which can effectively reduce heat loss or transfer, so that the prepared glass tea set can better maintain the temperature of the tea soup. In Example 8, when the mass ratio of silica sol and polyvinyl pyrrolidone is 1:0.7, the rotary coating speed is 3000rpm, and the pressure is 10MPa, the obtained glass has the best thermal insulation performance and a thermal conductivity coefficient of 0.16W / m 2 ·K. In Comparative Example 9, polyvinyl pyrrolidone was not added when preparing the aerogel interlayer. Polyvinyl pyrrolidone serves as a dispersant and pore stabilizer. Its absence leads to a decrease in the degree of cross-linking of the aerogel skeleton during the sol-gel reaction, agglomeration of nanoparticles, formation of large pores and even cracks, which reduces the mean free path of gas molecules and enhances gas relative flow and conduction. In Comparative Example 10, the rotary coating process was replaced by ordinary coating when preparing the aerogel interlayer. The uniform thickness control of the rotary process could not be achieved, resulting in local high-density areas and weak areas in the aerogel layer. The uneven thickness of the coating caused heat flow concentration, and the solid-phase thermal conductivity of the high-density area increased. In Comparative Example 11, supercritical drying was replaced by ordinary oven drying when preparing the aerogel interlayer. The aerogel was dried at 40°C for 4 hours. The surface tension of the liquid caused the aerogel pores to collapse, forming a dense capillary network, and the proportion of solid-phase heat conduction increased significantly. In Comparative Example 12, the prepared multi-layer insulating glass did not include an aerogel interlayer and relied solely on the glass matrix and composite insulation layer for insulation. Heat was directly transferred through conduction and convection through the air layer, resulting in reduced insulation performance. In Comparative Example 13, the prepared multi-layer insulating glass did not include a composite insulation layer, resulting in significantly reduced insulation performance.

[0082] Examples 11-13

[0083] Referring to the preparation method and parameter conditions of Example 8, the specific differences are shown in Table 5; the mass ratio of the two in Table 5 is the mass ratio of aluminum silicate sol and nano zirconium oxide; the temperature is the heating temperature of the bonding slurry in a nitrogen atmosphere after prepolymerization.

[0084] Comparative Example 14

[0085] The preparation method and parameter conditions are similar to those of Example 8, except that the rheological additive polyethylene oxide is not added when preparing the bonding slurry.

[0086] Comparative Example 15

[0087] The preparation method and parameter conditions are similar to those of Example 8, except that the bonding slurry is not coated.

[0088] Comparative Example 16

[0089] The preparation method and parameter conditions are similar to those of Example 8, except that nano-zirconia is not added when preparing the bonding slurry.

[0090] Experimental Example 4 Durability Test

[0091] The impact strength was tested according to GB / T 39814-2021. The results are shown in Table 5.

[0092] Table 5 Durability test of Example 8, Examples 11-13 and Comparative Examples 14-16

[0093] Example The quality ratio of the two Temperature / ℃ <![CDATA[Impact strength / kg / cm 2 > Example 8 7：1.5 300 2.28 Example 11 7：3 400 2.37 Example 12 7：4.5 450 2.30 Example 13 7：5 500 2.26 Comparative Example 14 7：1.5 300 2.03 Comparative Example 15 / / 1.80 Comparative Example 16 / 300 1.98

[0094] As can be seen from Table 5, in Examples 8 and 11-13, a stable chemical bond connection is formed at the interface through a low-temperature sintering bonding process based on nano-zirconia reinforcement, which significantly improves the interlayer bonding strength and high-temperature aging resistance. The nanoparticles in the bonding layer fill the micro-gaps and resist moisture penetration, avoiding stratification of the interface due to water vapor erosion during long-term use; the composite structure still maintains excellent stability in high temperature and high humidity environments, and the firm bonding of the coating and the substrate also enhances the overall impact resistance. Even special-shaped tea sets can withstand daily bumps and mechanical stress, and their durability is greatly improved. In Example 11, when the mass ratio of the two is 7:3 and the temperature is 400°C, the obtained glass has the best durability and an impact resistance of 2.37kg / cm 2 . In Comparative Example 14, the rheological additive polyethylene oxide was not added when preparing the bonding slurry, resulting in uncontrolled fluidity of the slurry, forming a bonding layer of uneven thickness after drying, with microcracks and voids inside. In Comparative Example 15, the bonding slurry was not coated, and under the impact load, the layers were quickly peeled off due to lack of adhesion, and the energy could not be transferred and dispersed through the interface. Each layer independently bore the impact force, and the brittle material was directly exposed to the stress, making it prone to brittle fracture. In Comparative Example 16, nano-zirconium oxide was not added when preparing the bonding slurry, the brittleness of the bonding layer increased, the impact energy could not be dissipated through mechanisms such as crack deflection, and the impact strength was reduced.

[0095] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing multi-layer insulating glass, characterized in that: The preparation method is as follows: a substrate is subjected to ion exchange between potassium nitrate molten salt and sodium nitrate molten salt to obtain a pretreated substrate; a composite thermal insulation coating is applied to the inner surface of the pretreated substrate; a silica sol and polyvinyl pyrrolidone are mixed and then spin-coated on the outer surface of the pretreated substrate to form an aerogel interlayer; and finally, a bonding slurry is applied and sintered to obtain the multi-layer thermal insulation glass. The composite thermal insulation coating is prepared from nano silicon carbide, nano zirconium dioxide and nano titanium dioxide particles; The bonding slurry is prepared from aluminum silicate sol and nano zirconium oxide.

2. The method for preparing multi-layer insulating glass according to claim 1, wherein: The pretreated substrate preparation method is as follows: borosilicate glass is ultrasonically cleaned with acetone and deionized water in sequence and dried to obtain a glass blank; a potassium nitrate molten salt bath is heated to 440-460° C., and the glass blank is immersed in the bath for treatment for 60 minutes; then, the glass blank is transferred to a sodium nitrate molten salt bath, treated at 495-515° C. for 30 minutes, and then washed with the deionized water and dried to obtain the pretreated substrate.

3. The method for preparing multi-layer insulating glass according to claim 2, wherein: The borosilicate glass comprises 75-85 wt % of silicon dioxide, 8-12 wt % of boron trioxide and 2-5 wt % of aluminum oxide.

4. The method for preparing multi-layer insulating glass according to claim 1, wherein: The preparation method of the composite thermal insulation coating is as follows: the nano-silicon carbide and the nano-zirconium dioxide are ball-milled for 4-6 hours, then added to xylene, and the silane coupling agent KH560 is added, and ultrasonic dispersion is performed to obtain a suspension; 1-3 parts of the nano-titanium dioxide particles are added to the suspension and ultrasonic dispersion is performed again to obtain a slurry; a high-voltage electrostatic generator is used to make the slurry sprayed from the spray gun adhere to the surface of the pretreated substrate to obtain the composite thermal insulation coating, the distance between the spray gun and the pretreated substrate is 15-20 cm, and the spraying pressure is 0.3-0.4 MPa.

5. The method for preparing multi-layer insulating glass according to claim 1, wherein: The aerogel interlayer preparation method is as follows: the silica sol and the polyvinyl pyrrolidone are mixed in a mass ratio of 1:0.5-2, and ultrasonically treated to form a composite sol; using a spin coating process, the composite sol is spin-coated at a speed of 2000-4000 rpm onto the surface of the pretreated substrate to form a wet film, and the film is allowed to stand at room temperature for 2 hours to obtain a gel film; the gel film is placed in a supercritical drying device, liquid CO2 is injected, the temperature is raised to 40°C, the pressure is increased to 7-15 MPa and maintained for 4 hours, and the pressure is released to obtain the aerogel interlayer.

6. The method for preparing multi-layer insulating glass according to claim 1, wherein: The bonding slurry is prepared as follows: the aluminum silicate sol and the nano zirconium oxide are mixed in a mass ratio of 7:1.5-5, a rheological additive is added, and the mixture is ball-milled to obtain the bonding slurry.

7. The method for preparing multi-layer insulating glass according to claim 1, wherein: The sintering steps are as follows: using a slit coater to apply the adhesive slurry to the edge bonding area of ​​the aerogel interlayer and then placing it on a fixture for prepolymerization; then, under a nitrogen atmosphere, heating to 300-500° C., keeping the temperature for 30 minutes, and cooling to room temperature to obtain the multi-layer insulating glass.

8. A multi-layer insulating glass, characterized in that: The multi-layer insulating glass consists of a pretreated substrate, a composite insulating coating, an aerogel interlayer and a bonding slurry; the multi-layer insulating glass is prepared by the preparation method according to any one of claims 1 to 7.

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