Multi-layer heat insulation glass and preparation method thereof

Abstract

The invention relates to the technical field of glass, in particular to multi-layer heat insulation glass and a preparation method thereof. The problems that common glass is poor in heat insulation performance and durability are solved. According to the invention, the borosilicate glass is subjected to ultrasonic cleaning by changing the component proportion of the borosilicate glass, and then is subjected to ion exchange through potassium nitrate molten salt and sodium nitrate molten salt, so that the durability of the glass is improved; composite heat-insulating coating slurry is prepared from nano silicon carbide, nano zirconium dioxide and nano titanium dioxide particles, and is attached to the surface of a pretreated base material by using an electrostatic spraying process, so that the heat-insulating property of the glass is improved; silica sol and polyvinylpyrrolidone are mixed and then spin-coated on the outer surface of a pretreated base material to obtain an aerogel interlayer, so that the heat insulation performance of the glass is improved; and stable chemical bond connection is formed at an interface through a low-temperature sintering and bonding process strengthened by nano-zirconia, so that the durability of the glass is greatly improved.

Description

Technical Field

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

[0002] In the family life scenario, glass products are widely used, and glass tea sets are deeply loved by tea lovers. However, traditional glass tea sets have obvious shortcomings in heat insulation performance: when people brew hot tea, ordinary single-layer glass tea sets conduct heat quickly, resulting in too high an outer wall temperature, which not only easily scalds the user's hand, 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 heat insulation to a certain extent, the effect is still not satisfactory, especially in cold seasons or after being placed for a long time, the temperature of the tea soup drops relatively quickly. In addition, from the perspective of durability, the frequency of using glass tea sets in families is relatively high. Traditional glass tea sets are prone to cracking due to thermal expansion and contraction during daily frequent hot and cold alternations. Their preparation process is complex and requires precise operation to ensure the sealing and uniformity of the glass, which leads to an increase in cost and unstable product quality. Ordinary families often have concerns when selecting. Therefore, researching and developing a multi-layer heat-insulating glass with excellent heat insulation performance and durability is of great significance for improving glass tea sets for household use and enhancing the quality of family life.

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

[0004] The purpose of the present invention is to provide a multi-layer heat-insulating glass and a preparation method thereof. By changing the proportion of borosilicate glass components, ultrasonic cleaning of the borosilicate glass is carried out, and then ion exchange is carried out with potassium nitrate molten salt and sodium nitrate molten salt to improve the durability of the glass; a composite heat-insulating coating slurry is prepared from nano silicon carbide, nano zirconia and nano titanium dioxide particles, and an electrostatic spraying process is used to make it adhere to the surface of the pretreated substrate to improve the heat insulation performance of the glass; a silica sol and polyvinylpyrrolidone are mixed and then spin-coated on the outer surface of the pretreated substrate to obtain an aerogel interlayer to improve the heat insulation performance of the glass; through a low-temperature sintering bonding process strengthened by nano zirconia, stable chemical bond connections are formed at the interface, greatly improving the durability of the glass.

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

[0006] On the one hand, the present invention provides a method for preparing a multilayer heat-insulating glass, and the preparation method is as follows: After the substrate is subjected to ion exchange in potassium nitrate molten salt and sodium nitrate molten salt, a pretreated substrate is obtained; a composite heat-insulating coating is coated on the inner surface of the pretreated substrate; silica sol and polyvinylpyrrolidone are mixed and then spin-coated on the outer surface of the pretreated substrate to form an aerogel interlayer; finally, a bonding slurry is coated and sintered to obtain the multilayer heat-insulating glass;

[0007] The composite heat-insulating coating is prepared from nano silicon carbide, nano zirconia and nano titanium dioxide particles;

[0008] The bonding slurry is prepared from aluminosilicate sol and nano zirconia.

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

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

[0011] Preferably, the method for preparing the composite heat-insulating coating is as follows: Nano silicon carbide and nano zirconia are added to a ball mill in a mass ratio of 12:8, ball-milled for 4 - 6 h, then added to xylene, and 0.5 part of silane coupling agent KH560 is added, and ultrasonically dispersed for 40 min to obtain a suspension; 1 - 3 parts of nano titanium dioxide particles are added to the suspension and ultrasonically dispersed for another 25 min to obtain a slurry; the slurry sprayed from a spray gun is attached to the surface of the pretreated substrate by using a high-voltage electrostatic generator to obtain the composite heat-insulating 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 method for preparing the aerogel interlayer is as follows: Silica sol and polyvinylpyrrolidone are mixed in a mass ratio of 1:0.5 - 2 and ultrasonically treated to form a composite sol; by using a spin-coating process, the composite sol is spin-coated on the surface of the pretreated substrate at a speed of 2000 - 4000 rpm to form a wet film, and left standing at room temperature for 2 h 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 h, and after pressure relief, the aerogel interlayer is obtained.

[0013] Preferably, the method for preparing the bonding slurry is as follows: Mix aluminum silicate sol and nano-zirconia according to a mass ratio of 7:1.5-5, add 2 wt% of the rheology aid polyethylene oxide based on the total amount of aluminum silicate sol and nano-zirconia, and ball-mill and mix for 4 h to obtain the bonding slurry.

[0014] Preferably, the sintering step is as follows: Use a slot coater to coat the bonding slurry on the edge fitting area of the aerogel sandwich and then place it in a fixture for pre-polymerization; then, under a nitrogen atmosphere, heat it to 300-500 °C at a rate of 5 °C / min, keep it warm for 30 min, and cool it to room temperature to obtain the multi-layer heat-insulating glass.

[0015] On the other hand, the present invention provides a multi-layer heat-insulating glass, which is composed of a pretreated substrate, a composite heat-insulating coating, an aerogel sandwich, and a bonding slurry; the multi-layer heat-insulating glass is prepared by any one of the above preparation methods.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] 1. In the present invention, by treating the glass blank in a potassium nitrate molten salt bath, the Na on the glass surface + is replaced with K in the molten salt + to form a preliminary compressive stress layer, and then secondary exchange treatment in a sodium nitrate molten salt bath is carried out 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 reduces the risk of cracking caused by collision and thermal cycling during daily use, greatly enhances the durability of the glass, and prolongs its service life.

[0018] 2. In the present invention, by preparing a composite heat-insulating coating, the composite matrix of nano-silicon carbide and zirconia 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, significantly reducing the proportion of radiation heat transfer; the electrostatic spraying process enables the nano-particles to be directionally enriched on the surface of the substrate to form a continuous and uniform structure, avoiding the thermal bridge effect caused by coating voids; the silane coupling agent strengthens the bonding strength between the nano-particles and the glass interface, ensuring the structural integrity of the coating during thermal cycling and improving the heat-insulating performance of the glass.

[0019] 3. In the present invention, by preparing an aerogel sandwich, the aerogel has an extremely low thermal conductivity and can effectively prevent heat conduction. After the components for preparing the aerogel sandwich are left standing at room temperature to form a gel film and then subjected to supercritical drying treatment, its internal pore structure is retained, greatly reducing air convection and conduction and further reducing the thermal conductivity; this aerogel sandwich forms an efficient heat-insulating barrier on the outer surface of the glass, and in cooperation with the inner composite heat-insulating coating, significantly improves the overall heat-insulating performance of the glass and can effectively reduce heat dissipation or heat transfer.

[0020] 4. Through the low-temperature sintering bonding process strengthened by nano-zirconia oxide, stable chemical bond connections are formed at the interface, significantly enhancing the interlayer bonding force and high-temperature aging resistance. The nano-particles in the bonding layer fill the micro-gaps and resist moisture penetration, preventing delamination 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 (such as steaming and steam sterilization). The firm bonding between the coating and the substrate also enhances the overall impact resistance. Even for special-shaped tea sets (such as curved kettle bodies), they can withstand daily bumps and mechanical stresses, greatly improving their durability. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0022] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0023] Please refer to Figure 1 , the present invention provides a multi-layer heat-insulating glass and a preparation method thereof, and the technical solutions are as follows:

[0024] The substances involved in the present invention are 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; Polyvinylpyrrolidone CAS: 9003 - 39 - 8; Nano-zirconia oxide CAS: 1314 - 23 - 4; Potassium nitrate of molten salt grade and sodium nitrate of molten salt grade are both purchased from Shandong Aobo Energy Storage Technology Co., Ltd.; Nano-zirconia dioxide, nano-titanium dioxide and silica sol are all purchased from Xuancheng Jingrui New Material Co., Ltd.; Aluminosilicate sol is purchased from Guangzhou Xinxi Metallurgical Chemical Co., Ltd.

[0026] Example 1

[0027] The borosilicate glass was ultrasonically cleaned successively with acetone and deionized water (frequency 40 kHz, 10 min each) and then dried to obtain a glass blank. The potassium nitrate molten salt bath was heated to 440 °C, and the glass blank was immersed therein for 60 min. Then the glass blank was transferred to a sodium nitrate molten salt bath and treated at 495 °C for 30 min, followed by washing with deionized water and drying to obtain a pretreated substrate. The borosilicate glass comprises 75 wt% silica, 8 wt% boron trioxide and 2 wt% alumina.

[0028] 12 parts of nano silicon carbide (average particle size 40 nm) and 8 parts of nano zirconia (average particle size 40 nm) were added to a ball mill and ball milled for 4 h, then added to 38 parts of xylene, and 0.5 part of silane coupling agent KH560 was added, followed by ultrasonic dispersion for 40 min to obtain a suspension. 1 part of nano titanium dioxide particles (average particle size 30 nm) was added to the suspension and ultrasonically dispersed again for 25 min to obtain a slurry. The droplets of the slurry ejected from the spray gun were charged negatively by using a high-voltage electrostatic generator, and the pretreated substrate was charged positively by grounding. Under the action of electrostatic attraction, the slurry adhered uniformly to the surface of the pretreated substrate to obtain a composite heat-insulating 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 polyvinylpyrrolidone were mixed at a mass ratio of 1:0.5 and ultrasonically treated (frequency 40 kHz, power 200 W) for 20 min to form a composite sol. By using a spin coating process, the composite sol was spin-coated onto the surface of the pretreated substrate at a speed of 2000 - 4000 rpm to form a wet film. The spin coating time was 30 s, and it was left standing at room temperature for 2 h to obtain a gel film. The gel film was placed in a supercritical drying device, liquid CO2 was injected to displace ethanol in the pores, the temperature was raised to 40 °C, the pressure was increased to 7 MPa and maintained for 4 h, and after pressure relief, an aerogel interlayer (thickness 100 μm) was obtained.

[0030] Aluminum silicate sol (solid content 25%) and nano zirconia (particle size 20 nm) were mixed at a mass ratio of 7:1.5, 2 wt% of the rheological aid polyethylene oxide based on the total amount of aluminum silicate sol and nano zirconia was added, and ball milled and mixed for 4 h to obtain an adhesive slurry. The adhesive slurry was coated on the edge fitting area of the aerogel interlayer by using a slot coater (gap height 100 μm) and then placed in a fixture for pre-polymerization (0.1 MPa). Then, in a nitrogen atmosphere, the temperature was raised to 300 °C at a rate of 5 °C / min, held for 30 min, and cooled to room temperature to obtain a multi-layer heat-insulating glass.

[0031] Examples 2 - 4

[0032] Referring 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] Referring to the preparation method and parameter conditions of Example 1, the difference is that the borosilicate glass was not ultrasonically cleaned successively with acetone and deionized water.

[0037] Comparative Example 2

[0038] Referring to the preparation method and parameter conditions of Example 1, the difference is that the glass blank was not treated in a potassium nitrate molten salt bath.

[0039] Comparative Example 3

[0040] Referring to the preparation method and parameter conditions of Example 1, the difference is that the glass blank was not treated in a sodium nitrate molten salt bath.

[0041] Comparative Example 4

[0042] Referring to the preparation method and parameter conditions of Example 1, the difference is that alumina was not added to the borosilicate glass.

[0043] Experimental Example 1 Durability performance test

[0044] Refer to the standard of GB / T 18144 - 2008 to test the surface compressive stress;

[0045] Thermal shock test: Immerse the prepared glass alternately in ice water at 0°C and boiling water at 100°C for 100 times, and observe whether there are cracks or delamination; the obtained results are shown in Table 2.

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

[0047] Example Surface compressive stress / MPa Thermal shock test Example 1 155 No cracks and no delamination Example 2 156 No cracks and no delamination Example 3 158 No cracks and no delamination Example 4 155 No cracks and no delamination Comparative Example 1 130 No cracks and no 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, by ultrasonically cleaning the borosilicate glass and then treating it in a potassium nitrate molten salt bath, the Na+ on the glass surface layer is replaced with K+ in the molten salt to form a preliminary compressive stress layer. Then, a secondary ion exchange treatment in a sodium nitrate molten salt bath is carried out to balance the deep-layer 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 cracking caused by collisions and thermal cycling during daily use, greatly enhances the durability of the glass, and extends its service life. When the temperature of the potassium nitrate molten salt bath is 450 °C, the temperature of the sodium nitrate molten salt bath is 505 °C, and the borosilicate glass contains 82 wt% silica, 11 wt% boron trioxide, and 4 wt% alumina, the prepared heat-insulating glass has the best durability, with a surface compressive stress of 158 MPa and no cracks or delamination under the thermal shock test. In Comparative Example 1, the borosilicate glass was not ultrasonically cleaned successively with acetone and deionized water, and the contaminants caused uneven contact between the glass matrix and the molten salt, resulting in incomplete exchange of K + and Na + , a reduction in the thickness of the compressive stress layer and uneven distribution, and an increase in local stress weak areas. In Comparative Example 2, the glass blank was not treated in a potassium nitrate molten salt bath, lacking the dense K + replacement layer on the surface, resulting in a low overall compressive stress level, accelerated deep-layer stress relaxation, and insufficient ability to inhibit crack propagation; the tensile strength of the glass matrix was insufficient, and microcracks were easily formed on the surface under thermal cycling due to tensile stress. In Comparative Example 3, the glass blank was not treated in a sodium nitrate molten salt bath, and the deep-layer stress gradient was not balanced by secondary Na + backfilling, increasing brittleness and reducing the mechanical shock resistance of the glass matrix; during rapid temperature changes, stress release was caused by the expansion difference at different depths. In Comparative Example 4, alumina was not added to the borosilicate glass, reducing the stability of the glass network structure 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-zirconia when preparing the composite heat-insulating coating.

[0051] Comparative Example 5

[0052] Referring to the preparation method and parameter conditions of Example 3, the difference is that nano-silicon carbide was not added when preparing the composite heat-insulating coating.

[0053] Comparative Example 6

[0054] Referring to the preparation method and parameter conditions of Example 3, the difference is that nano-zirconia was not added when preparing the composite heat-insulating coating.

[0055] Comparative Example 7

[0056] Referring to the preparation method and parameter conditions of Example 3, the difference is that nano-titanium dioxide was not added when preparing the composite thermal insulation coating.

[0057] Comparative Example 8

[0058] Referring to the preparation method and parameter conditions of Example 3, the difference is that the electrostatic spraying process was not used when preparing the composite thermal insulation coating, but it was directly sprayed with a spray gun.

[0059] Experimental Example 2 Thermal Insulation Performance Test

[0060] Referring to the standard of GB / T 38712-2020 to test the thermal conductivity;

[0061] Infrared isolation rate test method: Using a 150W Philips infrared halogen lamp as the light source, the test distance between the sample and the light source is 10 cm. Use an LS122 infrared power meter to test the radiation powers S0 and S1 before and after the sample glass barrier, and through the formula Calculate the infrared isolation rate; the obtained 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, Examples 5-7, by preparing the composite thermal insulation coating, the composite matrix of nano-silicon carbide and zirconia 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; the electrostatic spraying process enables the nano-particles to be directionally enriched on the surface of the substrate, forming a continuous and uniform structure, avoiding the thermal bridge effect caused by the coating voids; the silane coupling agent strengthens the bonding strength between the nano-particles and the glass interface, ensuring the structural integrity of the coating during thermal cycling and improving the thermal insulation performance of the glass. In Example 5, when the ball milling time is 5h, the dosage of nano-titanium dioxide is 2 parts, the spray gun distance is 18 cm, and the spraying pressure is 0.35 MPa, the prepared glass has the best thermal insulation performance, the infrared isolation rate is 98.2%, and the thermal conductivity is 0.2W / m 2·K. In Comparative Example 5, nano-silicon carbide was not added during the preparation of the composite thermal insulation coating, which cut off the phonon scattering network inside the coating, weakened the ability to block solid heat transfer, and partially lost its own optical reflection characteristics. In Comparative Example 6, nano-zirconia was not added during the preparation of the composite thermal insulation coating. As a low-thermal-conductivity framework, its absence destroyed the dense stacking structure between nanoparticles, and at the same time, the selective reflection effect on medium and far infrared was lost, the porosity of particle stacking increased, and the proportion of gas convection heat transfer rose. In Comparative Example 7, nano-titanium dioxide was not added during the preparation of the composite thermal insulation coating. Titanium dioxide has high refractive index and wide-spectrum infrared reflection characteristics, and its absence makes the coating lose the core reflection barrier to thermal radiation. In Comparative Example 8, the electrostatic spraying process was not used during the preparation of the composite thermal insulation coating, but it was directly sprayed with a spray gun, resulting in disordered particle stacking, and the microstructure of the coating was island-shaped, forming a "short-circuit channel" for heat conduction and fracture of the reflection 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; in Table 4, the mass ratio of the two is the mass ratio of silica sol and polyvinylpyrrolidone; the pressure is the pressure of supercritical drying when preparing the aerogel interlayer.

[0067] Comparative Example 9

[0068] Referring to the preparation method and parameter conditions of Example 5, the difference is that polyvinylpyrrolidone was not added when preparing the aerogel interlayer.

[0069] Comparative Example 10

[0070] Referring to the preparation method and parameter conditions of Example 5, the difference is that the spin coating process was replaced with ordinary coating when preparing the aerogel interlayer.

[0071] Comparative Example 11

[0072] Referring to the preparation method and parameter conditions of Example 5, the difference is that supercritical drying was replaced with ordinary oven drying at 40 °C for 4 h when preparing the aerogel interlayer.

[0073] Comparative Example 12

[0074] Referring to the preparation method and parameter conditions of Example 5, the difference is that the prepared multi-layer insulating glass does not include an aerogel interlayer.

[0075] Comparative Example 13

[0076] Referring to the preparation method and parameter conditions of Example 5, the difference is that the prepared multi-layer insulating glass does not include a composite thermal insulation layer.

[0077] Experimental Example 3 Thermal Insulation Performance Test

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

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

[0080] Example Mass 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 an aerogel interlayer, the aerogel has an extremely low thermal conductivity and can effectively prevent heat conduction. After the components for preparing the aerogel interlayer are left standing at room temperature to form a gel film and then subjected to supercritical drying treatment, the internal pore structure is retained, significantly reducing air convection and conduction and further reducing the thermal conductivity; the aerogel interlayer forms an efficient thermal insulation barrier on the outer surface of the glass, and synergistically acts with the inner composite thermal insulation coating to significantly improve the overall thermal insulation performance of the glass, effectively reducing heat loss or heat transfer, enabling the prepared glass tea set to better maintain the temperature of the tea soup. In Example 8, when the mass ratio of silica sol to polyvinylpyrrolidone is 1:0.7, the spin coating speed is 3000 rpm, and the pressure is 10 MPa, the prepared glass has the best thermal insulation performance, and the thermal conductivity is 0.16 W / m 2 ·K. In Comparative Example 9, polyvinylpyrrolidone was not added during the preparation of the aerogel interlayer. As a dispersant and pore stabilizer, the absence of polyvinylpyrrolidone results in a decrease in the crosslinking degree of the aerogel skeleton during the sol-gel reaction process, agglomeration of nanoparticles, formation of macropores or even cracks, reducing the mean free path of gas molecules and enhancing gas convection and conduction. In Comparative Example 10, the spin coating process was replaced with a conventional coating process during the preparation of the aerogel interlayer, and the uniform thickness control of the spin process could not be achieved, resulting in local high-density areas and weak areas in the aerogel layer. The uneven thickness of the coating causes heat flux concentration and an increase in the solid-phase thermal conductivity of the high-density area. In Comparative Example 11, the supercritical drying was replaced with ordinary oven drying during the preparation of the aerogel interlayer, and dried at 40 °C for 4 h. The surface tension of the liquid causes the collapse of the aerogel pores, forming a dense capillary pore network, and the proportion of solid-phase heat conduction increases significantly. In Comparative Example 12, the prepared multi-layer thermal insulation glass does not include an aerogel interlayer and relies only on the glass substrate and the composite thermal insulation layer for heat insulation. Heat is directly transferred through air layer conduction and convection, resulting in a decrease in heat insulation performance. In Comparative Example 13, the prepared multi-layer thermal insulation glass does not include a composite thermal insulation layer, and the heat insulation performance decreases significantly.

[0082] Examples 11-13

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

[0084] Comparative Example 14

[0085] Referring to the preparation method and parameter conditions of Example 8, the difference is that the rheology aid polyethylene oxide was not added when preparing the bonding slurry.

[0086] Comparative Example 15

[0087] Referring to the preparation method and parameter conditions of Example 8, the difference is that the bonding slurry was not coated.

[0088] Comparative Example 16

[0089] Referring to the preparation method and parameter conditions of Example 8, the difference is that nano-zirconia was not added when preparing the bonding slurry.

[0090] Experimental Example 4 Durability Performance Test

[0091] The impact resistance strength was tested with reference to the standard of GB / T 39814-2021; the obtained results are shown in Table 5.

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

[0093] Example Mass ratio of the two Temperature / °C <![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 Example 8 and Examples 11-13, through the low-temperature sintering bonding process strengthened by nano-zirconia, stable chemical bond connections are formed at the interface, significantly improving the interlayer bonding force and high-temperature aging resistance. The nano-particles in the bonding layer fill the micro-gaps and resist moisture penetration, preventing delamination at 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 between the coating and the substrate also enhances the overall impact resistance. Even for shaped tea sets, they can withstand daily bumps and mechanical stresses, and their durability performance is greatly improved. In Example 11, when the mass ratio of the two is 7:3 and the temperature is 400 °C, the prepared glass has the best durability performance, and the impact resistance is 2.37 kg / cm 2 . In Comparative Example 14, the rheology aid polyethylene oxide was not added when preparing the bonding slurry, resulting in out-of-control fluidity of the slurry and a bonding layer with uneven thickness after drying, with micro-cracks and voids inside. In Comparative Example 15, the bonding slurry was not coated. Under impact load, each layer quickly peeled off due to lack of adhesion force, and the energy could not be transmitted and dispersed through the interface. Each layer independently withstood the impact force, and the brittle material was directly exposed to the stress, prone to brittle fracture. In Comparative Example 16, nano-zirconia 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 resistance strength decreased.

[0095] Although embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

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

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

3. The manufacturing method of a multi-layer heat-insulating glass according to claim 2, characterized in that: 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 preparation method of a multi-layer heat-insulating glass according to claim 1, characterized in that: The preparation method of the composite thermal insulation coating is as follows: The nano silicon carbide and the nano zirconia are ball-milled for 4 - 6 h and then added into xylene, and a silane coupling agent KH560 is added, and ultrasonic dispersion is carried out to obtain a suspension; 1 - 3 parts of the nano titanium dioxide particles are added into the suspension and ultrasonic treatment is carried out again to obtain a slurry; the slurry sprayed by a spray gun is attached to the surface of the pretreated substrate by using a high-voltage electrostatic generator 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 preparation method of a multi-layer heat-insulating glass according to claim 1, wherein: The preparation method of the aerogel interlayer is as follows: The silica sol and the polyvinylpyrrolidone are mixed according to a mass ratio of 1:0.5 - 2, and ultrasonic treatment is carried out to form a composite sol; by adopting a spin-coating process, the composite sol is spin-coated onto the surface of the pretreated substrate at a speed of 2000 - 4000 rpm to form a wet film, and the wet film is left standing at room temperature for 2 h 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 h, and after pressure relief, the aerogel interlayer is obtained.

6. The preparation method of a multi-layer insulating glass according to claim 1, characterized in that: The preparation method of the bonding slurry is as follows: The aluminosilicate sol and the nano zirconia are mixed according to a mass ratio of 7:1.5 - 5, a rheology aid is added, and ball-milling and mixing are carried out to obtain the bonding slurry.

7. The preparation method of a multi-layer heat-insulating glass according to claim 1, characterized in that: The sintering steps are as follows: The bonding slurry is coated on the edge fitting area of the aerogel interlayer by using a slot coater and then placed in a fixture for pre-polymerization; then, in a nitrogen atmosphere, the temperature is raised to 300 - 500 °C, held for 30 min, and cooled to room temperature to obtain the multi-layer thermal insulation glass.

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

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