Thermal insulation material and preparation method thereof

Abstract

The invention discloses a thermal insulation material and a preparation method thereof, and belongs to the technical field of thermal insulation materials. The preparation process is simple and controllable, the inorganic glass fiber felt serves as a framework, the surface of the inorganic glass fiber felt is coated with the thermal insulation coating, the problem that the thermal insulation coating cracks due to thermal expansion and cold contraction is solved, the inorganic glass fiber felt is treated through the silane coupling agent, the interface bonding force between the inorganic glass fiber felt and the thermal insulation coating can be enhanced, and the thermal insulation performance is improved. The thermal insulation coating can permeate into fiber gaps of the glass fiber felt to form a firm integrated structure, and by adding the aerogel compound, the heat conductivity coefficient of the material is remarkably reduced, and the thermal insulation performance of the material is improved. When the device is used for heat management of the household electrical appliance chip, a stable working temperature environment can be provided for the chip, and the overall safety of the household electrical appliance is greatly improved.

Description

Technical Field

[0001] The present invention relates to the field of thermal insulation technology, and in particular to a thermal insulation material and a preparation method thereof. Background Art

[0002] With the rapid development of modern electronic technology, the power density of home appliances continues to increase. Chips generate a lot of heat during operation. If the heat cannot be managed in a timely and effective manner, it will not only cause the chip itself to reduce its frequency due to overheating, unstable operation, shortened lifespan or even burn out, but may also pose a threat to the performance and safety of the entire home appliance. Therefore, effective thermal management has become a key technical issue to ensure the performance stability and service life of home appliances. Traditional heat dissipation methods mainly rely on active heat dissipation methods such as metal radiators and fans. However, in home appliances with limited space, these solutions often have problems such as heavy weight, high noise, and high energy consumption. Therefore, the development of efficient thermal insulation materials has become an important way to solve the thermal management problem of home appliances.

[0003] Chinese patent document CN106400301A discloses food-grade glass wool for home appliance insulation and its manufacturing method. The glass wool is composed of 95.9-97.8 parts by weight of centrifugal glass fiber, 2.0-3.5 parts of binder, and 0.2-0.6 parts of water. The thermal conductivity and other quality indicators of the fiber are as follows: thermal conductivity ≥ 0.042w / km, fiber diameter ≤ 6.0μm, and tensile strength ≥ 16N / cm 2 , cotton distribution uniformity ≤ 10%, slag shot content ≤ 0.5%, formaldehyde release rate 0, compression resilience-compression rate ≥ 50%, compression resilience-recovery rate ≥ 78%, fiber appearance smooth, uniform color, soft fiber, and good rebound. The glass wool of the present invention has low bulk density, thin thickness, and good elasticity, making it particularly suitable for use as thermal insulation glass wool in food-grade household appliances. However, this method has high equipment requirements and complex processes, resulting in high production costs.

[0004] Silica aerogel is a new type of lightweight nanoporous material with the characteristics of high specific surface area, high porosity and low thermal conductivity, and has excellent thermal insulation properties. However, due to its poor mechanical properties, the application of single silica aerogel is severely limited. At the same time, existing aerogel composites often use a simple physical mixing method, resulting in poor compatibility between different components, and the comprehensive performance of the composite material is difficult to achieve the ideal effect. Therefore, it is necessary to develop a new type of composite thermal insulation material and its preparation technology that has excellent thermal insulation performance, good mechanical properties, environmental friendliness and economic feasibility, so as to meet the urgent demand for efficient thermal management of modern home appliances. Summary of the Invention

[0005] The main purpose of the present invention is to provide a heat-insulating material and a preparation method thereof. The heat-insulating material obtained by the present invention has a low thermal conductivity and good mechanical properties.

[0006] To achieve the above-mentioned purpose, the present invention proposes a method for preparing a thermal insulation material, which comprises treating an inorganic glass fiber felt with a silane coupling agent, coating its surface with a thermal insulation coating composed of a mixture of sodium silicate, alumina powder, aerogel composite, calcium carbonate, carboxymethyl cellulose ether, sodium lauryl sulfate, and water, and drying the coating to obtain the thermal insulation material.

[0007] Preferably, the silane coupling agent is at least one of 3-aminopropyltriethoxysilane, γ-glycidyloxypropyltrimethoxysilane, and isocyanatepropyltriethoxysilane.

[0008] Preferably, the mass ratio of the sodium silicate, alumina powder, aerogel composite, calcium carbonate, carboxymethyl cellulose ether, sodium lauryl sulfate, and water is 10-30:20-30:10-20:5-10:1-5:0.1-0.5:50-80.

[0009] Further preferably, the method for preparing the aerogel composite comprises the following steps:

[0010] (1) adding hydrotalcite to water, heating and stirring, adding sodium lauryl sulfate, continuing stirring, filtering, washing, drying, and then adding to ethanol aqueous solution, adding KH550, stirring and reacting, filtering, collecting the solid, washing, and drying to obtain modified hydrotalcite;

[0011] (2) adding silica aerogel powder to an ethanol aqueous solution, adding mercaptopropylmethyldimethoxysilane, stirring to react, filtering, collecting the solid, washing, drying, and adding it to anhydrous ethanol, adding 2-aminocinnamic acid and a photoinitiator, and reacting under ultraviolet light to obtain a modified silica aerogel;

[0012] (3) Adding the modified hydrotalcite and the modified SiO2 aerogel to anhydrous ethanol, adding epichlorohydrin, adjusting the pH value to 8-9, and reflux reaction, adding the obtained solid product to water, then adding Na2HPO4 aqueous solution, and then adding ammonia water to adjust the pH to 11-12 to obtain a mixed slurry; adding Ca(NO3)2 aqueous solution to the mixed slurry, adding ammonia water during the addition to maintain the pH at 10-11, carrying out a hydrothermal reaction after the addition is completed, filtering, washing, and drying after the reaction is completed to obtain an aerogel composite.

[0013] Preferably, in step (1), the mass ratio of hydrotalcite, sodium lauryl sulfate and KH550 is 10-15:1-3:1-2; the heating reaction temperature is 60-80°C; the stirring reaction temperature is 40-60°C, and the reaction time is 3-5h.

[0014] In this step, sodium dodecyl sulfate is first used to replace the original anions between the hydrotalcite layers through ion exchange, which not only significantly increases the interlayer spacing but also destroys the interlayer hydrogen bond network, which is conducive to dispersion; then it is aminated using the silane coupling agent KH550 to provide reaction sites for subsequent chemical bonding.

[0015] Preferably, in step (2), the mass ratio of silica aerogel, mercaptopropylmethyldimethoxysilane, 2-aminocinnamic acid and photoinitiator is 15-25:3-5:4-6:0.5-1; the photoinitiator is one of benzophenone, benzoin methyl ether, and 2-hydroxy-2-methylpropiophenone; the stirring reaction temperature is 60-80°C, and the reaction time is 1-3h.

[0016] In this step, the silica aerogel powder is subjected to hydrophobic treatment on the pore surface. By grafting hydrophobic functional groups to resist capillary stress, the cracking of the aerogel and the collapse of the three-dimensional network structure are effectively prevented; and active amino groups are provided for subsequent reactions.

[0017] Preferably, in the step (3), the mass ratio of the modified hydrotalcite, modified SiO2 aerogel, epichlorohydrin, Na2HPO4 aqueous solution, and Ca(NO3)2 aqueous solution is 3-5:2-4:5-8:10-12:15-18; the concentration of the Na2HPO4 aqueous solution is 0.5-0.7 mol / L; the concentration of the Ca(NO3)2 aqueous solution is 0.8-1 mol / L; the hydrothermal reaction temperature is 130-140°C, and the time is 6-8h.

[0018] In this step, the modified hydrotalcite and the modified SiO2 aerogel are compounded under the cross-linking action of epichlorohydrin to form a stable covalent bond bridge between the two, forming a stable composite structure. Phase separation is avoided through chemical bonding, and the interface voids during ordinary physical mixing are avoided, thereby greatly reducing the thermal conductivity of the aerogel composite. Hydrotalcite has a layered structure and a high modulus, and acts as a rigid skeleton in the composite system, avoiding excessive deformation of the aerogel when subjected to stress, thereby improving the overall structural mechanical properties and stability, thereby enhancing the thermal insulation performance of the material. Finally, hydroxyapatite is in situ generated in the composite structure through a hydrothermal reaction. On the one hand, its low thermal conductivity and nanoscale size are utilized to further fill the tiny pores in the composite structure, forming a denser and more tortuous heat conduction path, which significantly enhances the thermal insulation performance of the material.

[0019] Preferably, the coating thickness of the thermal insulation coating is 3-5 mm.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The preparation process of the present invention is simple and controllable. It uses an inorganic glass fiber mat as a framework, and coats its surface with a thermal insulation coating, thus avoiding the problem of cracking of the thermal insulation coating due to thermal expansion and contraction. The inorganic glass fiber mat is treated with a silane coupling agent to enhance the interfacial bonding between the inorganic glass fiber mat and the thermal insulation coating, allowing the thermal insulation coating to penetrate the interfiber gaps of the glass fiber mat, forming a strong integrated structure. The addition of an aerogel composite significantly reduces the thermal conductivity of the material and improves its thermal insulation properties. Using it for thermal management of home appliance chips can provide a stable operating temperature environment for the chips and greatly enhance the overall safety of the home appliances. DETAILED DESCRIPTION

[0022] To avoid redundancy, the items used in the following examples are all commercially available products unless otherwise specified, and the methods used are all conventional methods unless otherwise specified.

[0023] The sources of some raw materials used in the present invention are as follows:

[0024] Hydrotalcite, magnesium-aluminum hydrotalcite, particle size ≤ 200 μm, was purchased from Zhejiang Huate New Materials Co., Ltd.

[0025] Silica aerogel powder, with a particle size of 50–100 nm, was purchased from Hebei Hegao Insulation Materials Co., Ltd.

[0026] Inorganic glass fiber felt was purchased from Taian Hongfa New Materials Co., Ltd.

[0027] Example 1

[0028] A method for preparing a heat-insulating material comprises the following steps:

[0029] S1, immersing the inorganic glass fiber felt in a 50 wt% 50 wt% ethanol aqueous solution, adding 3-aminopropyltriethoxysilane, heating at 45° C. for 2 h, taking out the inorganic glass fiber felt and drying it to obtain a pretreated inorganic glass fiber felt;

[0030] S2, 60g of hydrotalcite was added to 300mL of water, heated to 70°C and stirred for 0.5h, 10g of sodium lauryl sulfate was added, and stirring was continued for 1h. After the reaction was completed, it was filtered, washed, and dried, and then added to 300mL of 50wt% ethanol aqueous solution, 7.5g of KH550 was added, and the reaction was stirred at 50°C for 4h, filtered, and the solid was collected, washed, and dried to obtain modified hydrotalcite;

[0031] S3, adding 40 g of silica aerogel powder to 300 mL of 50 wt% ethanol aqueous solution, adding 8 g of mercaptopropylmethyldimethoxysilane, stirring and reacting at 70° C. for 2 h, filtering, collecting the solid, washing, drying, and adding it to 300 mL of anhydrous ethanol, adding 10 g of 2-aminocinnamic acid and 1 g of benzoin methyl ether, and reacting under ultraviolet light with a wavelength of 365 nm for 1 h to obtain modified silica aerogel;

[0032] S4. Add 40 g of modified hydrotalcite and 30 g of modified SiO2 aerogel to 500 mL of anhydrous ethanol, add 60 g of epichlorohydrin, adjust the pH value to 9, and reflux the reaction at 60°C for 3 h. Add the obtained solid product to 100 mL of water, then add 110 g of 0.6 mol / L Na2HPO4 aqueous solution, and then add 28 wt% ammonia water to adjust the pH to 11 to obtain a mixed slurry; add 160 g of 0.9 mol / L Ca(NO3)2 aqueous solution dropwise to the mixed slurry, add ammonia water during the addition to maintain the pH at 10, and after the addition is completed, carry out a hydrothermal reaction at 140°C for 7 h. After the reaction is completed, cool, filter, wash and dry to obtain an aerogel composite;

[0033] S5. Mix 20g of sodium silicate, 25g of alumina powder, 15g of aerogel composite, 7.5g of calcium carbonate, 3g of carboxymethyl cellulose ether, 0.3g of sodium lauryl sulfate, and 60g of water and stir them evenly to obtain a thermal insulation coating. Then, apply the thermal insulation coating evenly on the surface of the pretreated inorganic glass fiber felt. The thickness of the thermal insulation coating is 4mm. After the thermal insulation coating is dried, a thermal insulation material is obtained.

[0034] Example 2

[0035] A method for preparing a heat-insulating material comprises the following steps:

[0036] S1. Immerse the inorganic glass fiber felt in a 50 wt% ethanol aqueous solution, add 3-aminopropyltriethoxysilane, heat at 45° C. for 2 h, and remove the inorganic glass fiber felt;

[0037] S2, 50g of hydrotalcite was added to 300mL of water, heated to 60°C and stirred for 0.5h, 10g of sodium lauryl sulfate was added, and stirring was continued for 1h. After the reaction was completed, it was filtered, washed, and dried, and then added to 300mL of 50wt% ethanol aqueous solution, 5g of KH550 was added, and the reaction was stirred at 40°C for 5h, filtered, and the solid was collected, washed, and dried to obtain modified hydrotalcite;

[0038] S3, adding 30 g of silica aerogel powder to 300 mL of 50 wt% ethanol aqueous solution, adding 8 g of mercaptopropylmethyldimethoxysilane, stirring and reacting at 70° C. for 2 h, filtering, collecting the solid, washing, drying, and adding it to 300 mL of anhydrous ethanol, adding 6 g of 2-aminocinnamic acid and 0.8 g of benzoin methyl ether, and reacting under ultraviolet light with a wavelength of 365 nm for 1 h to obtain modified silica aerogel;

[0039] S4. Add 30 g of modified hydrotalcite and 20 g of modified SiO2 aerogel to 500 mL of anhydrous ethanol, add 50 g of epichlorohydrin, adjust the pH value to 9, and reflux the reaction at 60°C for 3 h. Add the obtained solid product to 100 mL of water, then add 100 g of 0.5 mol / L Na2HPO4 aqueous solution, and then add 28 wt% ammonia water to adjust the pH to 11 to obtain a mixed slurry; add 150 g of 0.8 mol / L Ca(NO3)2 aqueous solution dropwise to the mixed slurry, add ammonia water during the addition to maintain the pH at 10, and after the addition is completed, carry out a hydrothermal reaction at 130°C for 8 h. After the reaction is completed, cool, filter, wash and dry to obtain an aerogel composite;

[0040] S5. Mix 10g of sodium silicate, 20g of alumina powder, 10g of aerogel composite, 5g of calcium carbonate, 1g of carboxymethyl cellulose ether, 0.1g of sodium lauryl sulfate, and 50g of water and stir them evenly to obtain a thermal insulation coating. Then, apply the thermal insulation coating evenly on the surface of the pretreated inorganic glass fiber felt. The thickness of the thermal insulation coating is 3mm. After the thermal insulation coating is dried, a thermal insulation material is obtained.

[0041] Example 3

[0042] A method for preparing a heat-insulating material comprises the following steps:

[0043] S1. Immerse the inorganic glass fiber felt in a 50 wt% ethanol aqueous solution, add 3-aminopropyltriethoxysilane, heat at 45° C. for 2 h, and remove the inorganic glass fiber felt;

[0044] S2, 75g of hydrotalcite was added to 400mL of water, heated to 70°C and stirred for 0.5h, 15g of sodium lauryl sulfate was added, and stirring was continued for 1h. After the reaction was completed, it was filtered, washed, and dried, and then added to 300mL of 50wt% ethanol aqueous solution, 10g of KH550 was added, and the reaction was stirred at 50°C for 4h, filtered, and the solid was collected, washed, and dried to obtain modified hydrotalcite;

[0045] S3. Add 50 g of silica aerogel powder to 400 mL of 50 wt% ethanol aqueous solution, add 10 g of mercaptopropylmethyldimethoxysilane, stir and react at 80° C. for 1 h, filter and collect the solid, wash and dry it, then add it to 300 mL of anhydrous ethanol, add 12 g of 2-aminocinnamic acid and 1 g of benzoin methyl ether, and react under ultraviolet light with a wavelength of 365 nm for 1 h to obtain modified silica aerogel;

[0046] S4. Add 50 g of modified hydrotalcite and 40 g of modified SiO2 aerogel to 500 mL of anhydrous ethanol, add 80 g of epichlorohydrin, adjust the pH value to 9, and reflux the reaction at 60°C for 3 h. Add the obtained solid product to 100 mL of water, then add 120 g of 0.6 mol / L Na2HPO4 aqueous solution, and then add 28 wt% ammonia water to adjust the pH to 11 to obtain a mixed slurry; add 180 g of 0.9 mol / L Ca(NO3)2 aqueous solution dropwise to the mixed slurry, add ammonia water during the addition to maintain the pH at 10, and after the addition is completed, carry out a hydrothermal reaction at 130°C for 8 h. After the reaction is completed, cool, filter, wash and dry to obtain an aerogel composite;

[0047] S5. Mix 30g of sodium silicate, 30g of alumina powder, 10g of rock wool fiber, 20g of aerogel composite, 10g of calcium carbonate, 5g of carboxymethyl cellulose ether, 0.5g of sodium lauryl sulfate, and 80g of water and stir them evenly to obtain a thermal insulation coating. Then, apply the thermal insulation coating evenly on the surface of the pretreated inorganic glass fiber felt. The thickness of the thermal insulation coating is 5mm. After the thermal insulation coating is dried, a thermal insulation material is obtained.

[0048] Comparative Example 1

[0049] A method for preparing a heat-insulating material comprises the following steps:

[0050] S1, immersing the inorganic glass fiber felt in a 50 wt% 50 wt% ethanol aqueous solution, adding 3-aminopropyltriethoxysilane, heating at 45° C. for 2 h, taking out the inorganic glass fiber felt and drying it to obtain a pretreated inorganic glass fiber felt;

[0051] S2, 60g of hydrotalcite was added to 300mL of water, heated to 70°C and stirred for 0.5h, 10g of sodium lauryl sulfate was added, and stirring was continued for 1h. After the reaction was completed, it was filtered, washed, and dried, and then added to 300mL of 50wt% ethanol aqueous solution, 7.5g of KH550 was added, and the reaction was stirred at 50°C for 4h, filtered, and the solid was collected, washed, and dried to obtain modified hydrotalcite;

[0052] S3, adding 40 g of silica aerogel powder to 300 mL of 50 wt% ethanol aqueous solution, adding 8 g of mercaptopropylmethyldimethoxysilane, stirring and reacting at 70° C. for 2 h, filtering, collecting the solid, washing, drying, and adding it to 300 mL of anhydrous ethanol, adding 10 g of 2-aminocinnamic acid and 1 g of benzoin methyl ether, and reacting under ultraviolet light with a wavelength of 365 nm for 1 h to obtain modified silica aerogel;

[0053] S4, adding 40 g of modified hydrotalcite and 30 g of modified SiO2 aerogel to 500 mL of anhydrous ethanol, adding 60 g of epichlorohydrin, adjusting the pH value to 9, and refluxing at 60 ° C for 3 h. After the reaction is completed, cooling, filtering, washing, and drying to obtain an aerogel composite;

[0054] S5. Mix 20g of sodium silicate, 25g of alumina powder, 15g of aerogel composite, 7.5g of calcium carbonate, 3g of carboxymethyl cellulose ether, 0.3g of sodium lauryl sulfate, and 60g of water and stir them evenly to obtain a thermal insulation coating. Then, apply the thermal insulation coating evenly on the surface of the pretreated inorganic glass fiber felt. The thickness of the thermal insulation coating is 4mm. After the thermal insulation coating is dried, a thermal insulation material is obtained.

[0055] Comparative Example 2

[0056] A method for preparing a heat-insulating material comprises the following steps:

[0057] S1, immersing the inorganic glass fiber felt in a 50 wt% 50 wt% ethanol aqueous solution, adding 3-aminopropyltriethoxysilane, heating at 45° C. for 2 h, taking out the inorganic glass fiber felt and drying it to obtain a pretreated inorganic glass fiber felt;

[0058] S2. 40 g of silica aerogel powder was added to 300 mL of a 50 wt% ethanol aqueous solution, 8 g of mercaptopropylmethyldimethoxysilane was added, and the mixture was stirred and reacted at 70° C. for 2 h. The solid was collected by filtration, washed, and dried, and then added to 300 mL of anhydrous ethanol. 10 g of 2-aminocinnamic acid and 1 g of benzoin methyl ether were added, and the mixture was reacted under ultraviolet light with a wavelength of 365 nm for 1 h to obtain a modified silica aerogel.

[0059] S3. Add hydrotalcite and 30 g of modified SiO2 aerogel to 100 mL of water, then add 110 g of 0.6 mol / L Na2HPO4 aqueous solution, and then add 28 wt% ammonia water to adjust the pH to 11 to obtain a mixed slurry; add 160 g of 0.9 mol / L Ca(NO3)2 aqueous solution dropwise to the mixed slurry, adding ammonia water to maintain the pH at 10 during the addition, and perform a hydrothermal reaction at 140°C for 7 h after the addition is completed. After the reaction is completed, cool, filter, wash, and dry to obtain an aerogel composite;

[0060] S4. Mix 20g of sodium silicate, 25g of alumina powder, 15g of aerogel composite, 7.5g of calcium carbonate, 3g of carboxymethyl cellulose ether, 0.3g of sodium lauryl sulfate and 60g of water and stir them evenly to obtain a thermal insulation coating. Then, apply the thermal insulation coating evenly on the surface of the pretreated inorganic glass fiber felt. The thickness of the thermal insulation coating is 4mm. After the thermal insulation coating is dried, a thermal insulation material is obtained.

[0061] Comparative Example 3

[0062] A method for preparing a heat-insulating material comprises the following steps:

[0063] S1, immersing the inorganic glass fiber felt in a 50 wt% 50 wt% ethanol aqueous solution, adding 3-aminopropyltriethoxysilane, heating at 45° C. for 2 h, taking out the inorganic glass fiber felt and drying it to obtain a pretreated inorganic glass fiber felt;

[0064] S2, 60g of hydrotalcite was added to 300mL of water, heated to 70°C and stirred for 0.5h, 10g of sodium lauryl sulfate was added, and stirring was continued for 1h. After the reaction was completed, it was filtered, washed, and dried, and then added to 300mL of 50wt% ethanol aqueous solution, 7.5g of KH550 was added, and the reaction was stirred at 50°C for 4h, filtered, and the solid was collected, washed, and dried to obtain modified hydrotalcite;

[0065] S3. Add 40 g of modified hydrotalcite and 30 g of SiO2 aerogel powder to 100 mL of water, then add 110 g of 0.6 mol / L Na2HPO4 aqueous solution, and then add 28 wt% ammonia water to adjust the pH to 11 to obtain a mixed slurry; add 160 g of 0.9 mol / L Ca(NO3)2 aqueous solution dropwise to the mixed slurry, add ammonia water during the addition to maintain the pH at 10, and after the addition is completed, perform a hydrothermal reaction at 140°C for 7 h. After the reaction is completed, cool, filter, wash, and dry to obtain an aerogel composite;

[0066] S4. Mix 20g of sodium silicate, 25g of alumina powder, 15g of aerogel composite, 7.5g of calcium carbonate, 3g of carboxymethyl cellulose ether, 0.3g of sodium lauryl sulfate and 60g of water and stir them evenly to obtain a thermal insulation coating. Then, apply the thermal insulation coating evenly on the surface of the pretreated inorganic glass fiber felt. The thickness of the thermal insulation coating is 4mm. After the thermal insulation coating is dried, a thermal insulation material is obtained.

[0067] Performance Testing

[0068] The thermal insulation materials prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to performance tests, wherein the thermal conductivity was tested in accordance with GB / T10294-2008 "Determination of Steady-State Thermal Resistance and Related Properties of Thermal Insulation Materials - Guarded Hot Plate Method";

[0069] The tensile strength test was carried out in accordance with GB / T30804-2014 "Determination of tensile strength of thermal insulation products for building use perpendicular to the surface" using a B-type specimen structure. The test results are shown in Table 1:

[0070] Table 1 Test results of thermal insulation material performance

[0071]

[0072]

[0073] It can be seen from the experimental results in Table 1 that the thermal insulation material obtained by the present invention has good thermal insulation and mechanical properties.

[0074] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of the present invention.

Claims

1. A method for preparing a heat-insulating material, characterized in that: The method comprises the following steps: treating an inorganic glass fiber felt with a silane coupling agent, coating the surface of the inorganic glass fiber felt with a thermal insulation coating prepared by mixing sodium silicate, aluminum oxide powder, aerogel composite, calcium carbonate, carboxymethyl cellulose ether, sodium lauryl sulfate and water, and drying the coating to obtain the thermal insulation material.

2. The preparation method according to claim 1, wherein: The silane coupling agent is at least one of 3-aminopropyltriethoxysilane, γ-glycidyloxypropyltrimethoxysilane, and isocyanatepropyltriethoxysilane.

3. The preparation method according to claim 1, characterized in that The mass ratio of the sodium silicate, alumina powder, aerogel composite, calcium carbonate, carboxymethyl cellulose ether, sodium lauryl sulfate and water is 10-30:20-30:10-20:5-10:1-5:0.1-0.5:50-80.

4. The preparation method according to claim 1 or 3, characterized in that The method for preparing the aerogel composite comprises the following steps: (1) adding hydrotalcite to water, heating and stirring, adding sodium lauryl sulfate, continuing stirring, filtering, washing, drying, and then adding to ethanol aqueous solution, adding KH550, stirring and reacting, filtering, collecting the solid, washing, and drying to obtain modified hydrotalcite; (2) adding silica aerogel powder to an ethanol aqueous solution, adding mercaptopropylmethyldimethoxysilane, stirring to react, filtering, collecting the solid, washing, drying, and adding it to anhydrous ethanol, adding 2-aminocinnamic acid and a photoinitiator, and reacting under ultraviolet light to obtain a modified silica aerogel; (3) Adding the modified hydrotalcite and the modified SiO2 aerogel to anhydrous ethanol, adding epichlorohydrin, adjusting the pH value to 8-9, and reflux reaction, adding the obtained solid product to water, then adding Na2HPO4 aqueous solution, and then adding ammonia water to adjust the pH to 11-12 to obtain a mixed slurry; adding Ca(NO3)2 aqueous solution to the mixed slurry, adding ammonia water during the addition to maintain the pH at 10-11, carrying out a hydrothermal reaction after the addition is completed, filtering, washing, and drying after the reaction is completed to obtain an aerogel composite.

5. The preparation method according to claim 4, characterized in that: In the step (1), the mass ratio of hydrotalcite, sodium lauryl sulfate and KH550 is 10-15:1-3:1-2.

6. The preparation method according to claim 4, characterized in that: In the step (2), the mass ratio of the silica aerogel, mercaptopropylmethyldimethoxysilane, 2-aminocinnamic acid and the photoinitiator is 15-25:3-5:4-6:0.5-1.

7. The preparation method according to claim 4, characterized in that: The photoinitiator is one of benzophenone, benzoin methyl ether and 2-hydroxy-2-methylpropiophenone.

8. The preparation method according to claim 4, characterized in that: In the step (3), the mass ratio of the modified hydrotalcite, modified SiO2 aerogel, epichlorohydrin, Na2HPO4 aqueous solution, and Ca(NO3)2 aqueous solution is 3-5:2-4:5-8:10-12:15-18.

9. The preparation method according to claim 4, characterized in that: The hydrothermal reaction temperature in step (3) is 130-140° C. and the reaction time is 6-8 hours.

10. The preparation method according to claim 1, characterized in that: The coating thickness of the thermal insulation coating is 3-5 mm.

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