An architectural heat-insulating and fireproof coating containing an aerogel composite modified silicate binder and a preparation method thereof

Abstract

The present invention relates to the technical field of architectural coatings, and provides an architectural heat-insulating and fireproof coating containing an aerogel composite modified silicate binder and a preparation method thereof. The architectural heat-insulating and fireproof coating includes a modified silica aerogel, a modified silicate binder, fillers and additives. In the present invention, carboxylated modified halloysite and nanofibers are used to modify the silica aerogel, enhancing the heat-insulating performance of the silica aerogel and the binding force with the binder; while the heat-insulating, fireproof and mechanical properties of the silicate binder are synergistically enhanced by modified vermiculite and modified inorganic fibers. The architectural heat-insulating and fireproof coating provided by the present invention has good heat-insulating and fireproof properties.

Description

Technical Field

[0001] The present invention belongs to the field of architectural coatings, and relates to an architectural heat-insulating and fireproof coating containing an aerogel composite-modified silicate binder and a preparation method thereof. Background Art

[0002] The heat-insulating and fireproof properties of buildings are key factors to ensure the safety and energy efficiency of buildings. Traditional heat-insulating and fireproof coatings, such as inorganic mineral coatings and organic polymer coatings, have disadvantages such as poor high-temperature resistance, high thermal conductivity, easy cracking, and easy combustion, and are difficult to meet the requirements of modern buildings for heat-insulating and fireproof materials.

[0003] As the main component of heat-insulating and fireproof coatings, silicate binders (such as water glass, aluminum silicate, lithium silicate, etc.) are widely sourced, low-cost, and have a simple preparation process, making them easy to mass-produce. Secondly, silicate binders have excellent high-temperature resistance and can maintain their stability in high-temperature environments without easy decomposition or deterioration. In addition, silicate binders also have good insulation properties and certain corrosion resistance capabilities, giving them good application prospects in various harsh environments. However, a single silicate binder also has significant defects in practical applications: the durability of silicate binders is poor, and they are prone to aging, cracking, etc. when exposed to the natural environment for a long time, thus affecting their service life. Summary of the Invention

[0004] Aiming at the above problems, the purpose of the present invention is to provide an architectural heat-insulating and fireproof coating containing an aerogel composite-modified silicate binder and a preparation method thereof. The present invention modifies the silicate binder by introducing modified vermiculite and modified inorganic fibers. Vermiculite expands at high temperatures to form a porous structure, significantly improving the heat-insulating and fireproof properties of the material and enhancing its durability to a certain extent. Adding inorganic fibers can enhance the toughness and impact resistance of the silicate binder, and the high strength and high modulus of inorganic fibers contribute to improving the mechanical properties of the composite material. At the same time, inorganic fibers and vermiculite can act synergistically to increase the crack resistance and durability of the material. During the curing process, inorganic fibers can prevent the propagation of cracks, while the porous structure formed by vermiculite can absorb stress, thus reducing the cracking phenomenon during curing and use; the introduction of modified aerogel can also form a tight bond with the binder matrix, significantly improving its mechanical strength, durability, and adhesiveness. These modification measures work together to make the modified silicate binder have excellent heat-insulating properties, mechanical strength, and durability, meeting the energy conservation and environmental protection requirements of buildings.

[0005] To achieve this purpose, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides a building heat-insulating and fireproof coating containing an aerogel composite-modified silicate binder, and the building heat-insulating and fireproof coating comprises a modified silica aerogel, a modified silicate binder, fillers, and additives.

[0007] The brittleness, poor durability, shrinkage, and deformation during the curing process of silicate binders restrict their development in practical applications. In the present invention, vermiculite, inorganic fibers, and aerogels are introduced to modify the silicate binder. Vermiculite expands at high temperatures to form a porous structure, significantly improving the heat-insulating and fireproof properties of the material and enhancing its durability to a certain extent. Adding inorganic fibers can enhance the toughness and impact resistance of the silicate binder, and the high strength and high modulus of the inorganic fibers contribute to improving the mechanical properties of the composite material. At the same time, inorganic fibers and vermiculite can act synergistically to increase the crack resistance and durability of the material. During the curing process, inorganic fibers can prevent the propagation of cracks, while the porous structure formed by vermiculite can absorb stress, thereby reducing cracking during curing and use; the introduction of modified aerogels can also form a tight bond with the binder matrix, significantly improving its mechanical strength, durability, and adhesiveness. These modification measures work together to make the modified silicate binder have excellent heat-insulating properties, mechanical strength, and durability, meeting the energy-saving and environmental protection requirements of buildings.

[0008] As a preferred technical solution of the present invention, the building heat-insulating and fireproof coating containing an aerogel composite-modified silicate binder comprises the following components in parts by mass:

[0009] Modified silica aerogel: 20 - 40 parts

[0010] Modified silicate binder: 30 - 50 parts

[0011] Fillers: 10 - 30 parts

[0012] Additives: 5 - 10 parts

[0013] Deionized water: 40 - 50 parts

[0014] Among them, the mass parts of the modified silica aerogel can be 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, 26 parts, 27 parts, 28 parts, 29 parts, 30 parts, 31 parts, 32 parts, 33 parts, 34 parts, 35 parts, 36 parts, 37 parts, 38 parts, 39 parts or 40 parts; the mass parts of the modified silicate binder can be 30 parts, 31 parts, 32 parts, 33 parts, 34 parts, 35 parts, 36 parts, 37 parts, 38 parts, 39 parts, 40 parts, 41 parts, 42 parts, 43 parts, 44 parts, 45 parts, 46 parts, 47 parts, 48 parts, 49 parts or 50 parts; the mass parts of the filler can be 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, 26 parts, 27 parts, 28 parts, 29 parts or 30 parts; the mass parts of the auxiliary agent can be 5.0 parts, 5.5 parts, 6.0 parts, 6.5 parts, 7.0 parts, 7.5 parts, 8.0 parts, 8.5 parts, 9.0 parts, 9.5 parts or 10.0 parts; the mass parts of deionized water can be 40 parts, 41 parts, 42 parts, 43 parts, 44 parts, 45 parts, 46 parts, 47 parts, 48 parts, 49 parts or 50 parts. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0015] In the present invention, the silica aerogel is modified by carboxylated halloysite and nanofibrous carbon. Halloysite itself has certain high-temperature resistance and can form a material with good heat insulation performance under appropriate high-temperature conditions, further improving the heat insulation effect of the aerogel. Carboxylation modification can cause halloysite to undergo an esterification reaction with the hydroxyl groups on the surface of the aerogel to form covalent bonds, thereby enhancing the compatibility and binding force between halloysite and the aerogel matrix, forming a more stable composite structure and making the overall structure more stable and heat-resistant; at the same time, it can also react with the hydroxyl groups in the silicate binder to enhance the binding force between the binder and the aerogel.

[0016] The nanofibrous carbon has excellent mechanical strength and tensile resistance, and can effectively improve the mechanical properties of the aerogel. In a high-temperature environment, the nanofibrous carbon can evenly disperse heat and reduce local thermal stress concentration, thereby enhancing the stability and durability of the aerogel. In addition, the high specific surface area and unique structure of the nanofibrous carbon can provide more strengthening points, further improving the overall performance of the composite material.

[0017] The present invention particularly limits the mass parts of the modified silica aerogel to 20 - 40 parts. Since the structure of the aerogel is relatively brittle, too high a content may cause a decrease in the mechanical strength of the coating, affecting its service life in a harsh environment; at the same time, it may also cause a decrease in the adhesion between the coating and the substrate, thereby affecting the durability and stability of the coating.

[0018] The present invention modifies the silicate binder by introducing modified vermiculite and modified inorganic fibers. Vermiculite expands at high temperatures to form a porous structure, significantly improving the heat insulation and fire resistance of the material and enhancing its durability to a certain extent. Vermiculite is a layered silicate mineral. Under high-temperature conditions, the water between its layers evaporates, causing its volume to expand rapidly, forming a porous structure with a high specific surface area. This porous structure can not only effectively block the conduction of heat and improve the heat insulation performance of the material but also provide excellent fire resistance in case of a fire, preventing the spread of flames. In addition, the chemical stability and weather resistance of vermiculite enable it to maintain stable performance in various harsh environments for a long time.

[0019] Adding inorganic fibers can enhance the toughness and impact resistance of the silicate binder. For example, glass fibers have good chemical inertness and corrosion resistance and can remain stable in acidic and alkaline environments, while carbon fibers are known for their high strength and high modulus and can significantly improve the mechanical properties of composite materials. Inorganic fibers can effectively disperse and absorb external impact energy by forming a uniformly distributed reinforcement network in the matrix, enhancing the toughness and impact resistance of the material and preventing brittle fracture.

[0020] Inorganic fibers and vermiculite can act synergistically to increase the crack resistance and durability of the material. During the curing process, inorganic fibers act as a reinforcement skeleton, preventing the initiation and propagation of cracks and improving the overall crack resistance of the material. The porous structure formed by vermiculite can effectively absorb and disperse stress, reducing stress concentration and thus preventing cracking during curing and use. This porous structure also has a certain water absorption capacity, capable of absorbing and releasing moisture in a changing humidity environment, preventing cracks caused by wetting and drying shrinkage of the material, and further improving durability.

[0021] Introducing phenolic resin to modify inorganic fibers and vermiculite can improve their dispersibility and compatibility. The polar functional groups in phenolic resin, such as hydroxyl groups, can form hydrogen bonds with the polar groups on the surfaces of inorganic fibers and vermiculite, thus enhancing the interaction between the inorganic filler and the resin and improving their dispersibility and compatibility. At the same time, phenolic resin can form a modified layer with strong affinity on the surfaces of inorganic fibers and vermiculite, further promoting their dispersion and compatibility in the binder. In addition, the phenolic and formaldehyde groups in phenolic resin can undergo a condensation reaction with the active groups in the silicate binder to form covalent bonds, significantly enhancing the bonding strength between the inorganic filler and the binder and improving the interfacial bonding performance of the entire composite material.

[0022] The present invention specifically limits the mass fraction of the modified silicate binder to 30 - 50 parts. Increasing the content of the silicate binder can enhance the bonding strength of the coating, but too high a silicate content may cause the coating layer to become too brittle and hard, prone to cracking, thus affecting the use effect and durability of the coating.

[0023] In a second aspect, the present invention provides a method for preparing a heat-insulating and fireproof coating containing an aerogel composite modified silicate binder, and the preparation method is as follows:

[0024] S1: Add halloysite into absolute ethanol to obtain a halloysite dispersion, perform ultrasonic dispersion, and then add methacrylic acid. The obtained mixed dispersion is stirred at a constant temperature under nitrogen protection; the sample obtained after washing and suction filtration of the mixed dispersion is dried to obtain carboxylated modified halloysite; dissolve water glass in deionized water at room temperature, and perform ion exchange through a strongly acidic styrene-based cation exchange resin to obtain a silicic acid solution. Add sodium dodecyl sulfate to the silicic acid solution and stir until dissolved uniformly to obtain a mixed solution. Add the carboxylated modified halloysite and nanofibers to the mixed solution to obtain a precursor suspension, mechanically stir, and perform ultrasonic dispersion to form a suspension; adjust the pH of the suspension with an ammonia water solution, inject it into a polypropylene mold, let it stand, age after gel formation, take it out of the mold, place it in a first ethanol aqueous solution for the first immersion, and then transfer it to absolute ethanol for the second immersion to obtain a modified silica wet gel. Hydrophobically modify the modified silica wet gel, and then transfer it to a vacuum drying oven for drying to obtain a modified silica aerogel;

[0025] S2: Put inorganic fibers and vermiculite into a phenolic resin ethanol solution to obtain an inorganic fiber / vermiculite dispersion, stir and impregnate, and obtain a mixture after suction filtration. Heat-cure the mixture in an oven to obtain a modified inorganic fiber / vermiculite mixture; dissolve silicate in a second ethanol aqueous solution to obtain a silicate solution. Add a silane coupling agent and oleic acid to the silicate solution and stir to obtain a modified silicate solution. Add the modified inorganic fiber / vermiculite mixture to the modified silicate solution and continuously stir to obtain a mixed suspension;

[0026] S3: Crush and grind the modified silica aerogel, add it to the mixed suspension into deionized water, stir evenly, then add fillers, defoamers, dispersants, and thickeners and continue to stir to obtain the fireproof and heat-insulating coating.

[0027] As a preferred technical solution of the present invention, in step S1, the ultrasonic treatment time of the halloysite dispersion is 20 - 30 min, for example, it can be 20 min, 21 min, 22 min, 23 min, 24 min, 25 min, 26 min, 27 min, 28 min, 29 min, or 30 min, but is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0028] In some optional examples, the ultrasonic time for ultrasonic treatment of the halloysite dispersion is 1000 - 2000 W. For example, it can be 1000 W, 1100 W, 1200 W, 1300 W, 1400 W, 1500 W, 1600 W, 1700 W, 1800 W, 1900 W or 2000 W. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0029] In some optional examples, the mass ratio of the methacrylic acid to the halloysite is (2 - 3):1. For example, it can be 2:1, 2.1:1, 2.2:1, 2.3:1, 2.4:1, 2.5:1, 2.6:1, 2.7:1, 2.8:1, 2.9:1 or 3.0:1. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0030] In some optional examples, the constant temperature of the mixed dispersion is 70 - 80 °C. For example, it can be 70 °C, 71 °C, 72 °C, 73 °C, 74 °C, 75 °C, 76 °C, 77 °C, 78 °C, 79 °C or 80 °C. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0031] In some optional examples, the stirring time of the mixed dispersion is 2 - 4 h. For example, it can be 2.0 h, 2.2 h, 2.4 h, 2.6 h, 2.8 h, 3.0 h, 3.2 h, 3.4 h, 3.6 h, 3.8 h or 4.0 h. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0032] In some optional examples, the drying temperature of the sample is 70 - 90 °C. For example, it can be 70 °C, 72 °C, 74 °C, 76 °C, 78 °C, 80 °C, 82 °C, 84 °C, 86 °C, 88 °C or 90 °C. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0033] In some optional examples, the drying time of the sample is 6 - 8 h. For example, it can be 6.0 h, 6.2 h, 6.4 h, 6.6 h, 6.8 h, 7.0 h, 7.2 h, 7.4 h, 7.6 h, 7.8 h or 8.0 h. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0034] In some alternative examples, the volume ratio of the sodium silicate to deionized water is (3 to 4):1. For example, it can be 3.0:1, 3.1:1, 3.2:1, 3.3:1, 3.4:1, 3.5:1, 3.6:1, 3.7:1, 3.8:1, 3.9:1, 4.0:1. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0035] In some alternative examples, the concentration of sodium dodecyl sulfate added to the silicic acid solution is 14 - 16 mmol / L. For example, it can be 14.0 mmol / L, 14.2 mmol / L, 14.4 mmol / L, 14.6 mmol / L, 14.8 mmol / L, 15.0 mmol / L, 15.2 mmol / L, 15.4 mmol / L, 15.6 mmol / L, 15.8 mmol / L, or 16.0 mmol / L. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0036] In some alternative examples, the concentration of nano-carbon fibers added to the mixed solution is 1 - 4 wt%. For example, it can be 1.0 wt%, 1.3 wt%, 1.6 wt%, 1.9 wt%, 2.2 wt%, 2.5 wt%, 2.8 wt%, 3.1 wt%, 3.4 wt%, 3.7 wt%, or 4.0 wt%. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0037] In some alternative examples, the mass ratio of carboxylated modified halloysite to sodium silicate added to the mixed solution is (0.1 to 0.3):1. For example, it can be 0.1:1, 0.12:1, 0.14:1, 0.16:1, 0.18:1, 0.2:1, 0.22:1, 0.24:1, 0.26:1, 0.28:1, or 0.3:1. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0038] In some alternative examples, the ultrasonic treatment time of the suspension precursor is 20 - 30 min. For example, it can be 20 min, 21 min, 22 min, 23 min, 24 min, 25 min, 26 min, 27 min, 28 min, 29 min, or 30 min. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0039] In some optional examples, the frequency of ultrasonic treatment of the suspension precursor is 1000 - 2000 W. For example, it can be 1000 W, 1100 W, 1200 W, 1300 W, 1400 W, 1500 W, 1600 W, 1700 W, 1800 W, 1900 W or 2000 W. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0040] In some optional examples, the concentration of the ammonia water is 1 - 2 M. For example, it can be 1 M, 1.1 M, 1.2 M, 1.3 M, 1.4 M, 1.5 M, 1.6 M, 1.7 M, 1.8 M, 1.9 M or 2 M. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0041] In some optional examples, the pH of the suspension is adjusted to 5.0 - 6.0 with ammonia water. For example, it can be 5.0, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, 6.0. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0042] In some optional examples, the temperature for gel aging is 25 - 35 °C. For example, it can be 25°C, 26°C, 27°C, 28°C, 29°C, 30°C, 31°C, 32°C, 33°C, 34°C, 35°C. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0043] In some optional examples, the time for gel aging is 20 - 30 h. For example, it can be 20 h, 21 h, 22 h, 23 h, 24 h, 25 h, 26 h, 27 h, 28 h, 29 h, 30 h. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0044] In some optional examples, the volume fraction of the ethanol solution for the first soaking is 40 - 60%. For example, it can be 40%, 42%, 44%, 46%, 48%, 50%, 52%, 54%, 56%, 58%, or 60%. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0045] In some optional examples, the time interval for changing the solution during the first soaking and the second soaking is 6 - 8 h. For example, it can be 6.0 h, 6.2 h, 6.4 h, 6.6 h, 6.8 h, 7.0 h, 7.2 h, 7.4 h, 7.6 h, 7.8 h or 8.0 h. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0046] In some alternative examples, the temperature for vacuum drying the modified silica wet gel is 40 to 50 °C, such as 40 °C, 41 °C, 42 °C, 43 °C, 44 °C, 45 °C, 46 °C, 47 °C, 48 °C, 49 °C or 50 °C, but is not limited to the listed values, and other unlisted values within this range are equally applicable.

[0047] In some alternative examples, the time for vacuum drying the modified silica wet gel is 18 to 26 h, such as 18 h, 19 h, 20 h, 21 h, 22 h, 23 h, 24 h, 25 h or 26 h, but is not limited to the listed values, and other unlisted values within this range are equally applicable.

[0048] As a preferred technical solution of the present invention, in step S2, the mass ratio of phenolic resin to absolute ethanol in the phenolic resin ethanol solution is (1 to 2):10, such as 1:10, 1.1:10, 1.2:10, 1.3:10, 1.4:10, 1.5:10, 1.6:10, 1.7:10, 1.8:10, 1.9:10 or 2:10, but is not limited to the listed values, and other unlisted values within this range are equally applicable.

[0049] In some alternative examples, the stirring and impregnation time of the inorganic fiber / vermiculite dispersion is 1 to 3 h, such as 1 h, 1.2 h, 1.4 h, 1.6 h, 1.8 h, 2 h, 2.2 h, 2.4 h, 2.6 h, 2.8 h or 3 h, but is not limited to the listed values, and other unlisted values within this range are equally applicable.

[0050] In some alternative examples, the temperature for heat curing treatment of the mixture is 150 to 200 °C, such as 150 °C, 155 °C, 160 °C, 165 °C, 170 °C, 175 °C, 180 °C, 185 °C, 190 °C, 195 °C or 200 °C, but is not limited to the listed values, and other unlisted values within this range are equally applicable.

[0051] In some alternative examples, the time for heat curing treatment of the mixture is 2 to 4 h, such as 2 h, 2.2 h, 2.4 h, 2.6 h, 2.8 h, 3 h, 3.2 h, 3.4 h, 3.6 h, 3.8 h or 4 h, but is not limited to the listed values, and other unlisted values within this range are equally applicable.

[0052] In some optional examples, the volume ratio of absolute ethanol to deionized water in the second aqueous ethanol solution is (7 - 9):(1 - 3). For example, it can be 7:1, 7:2, 7:3, 8:1, 8:2, 8:3, 9:1, 9:2, or 9:3. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0053] In some optional examples, the mass ratio of the silicate to the second aqueous ethanol solution is 1:(2 - 3). For example, it can be 1:2, 1:2.1, 1:2.2, 1:2.3, 1:2.4, 1:2.5, 1:2.6, 1:2.7, 1:2.8, 1:2.9, or 1:3. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0054] In some optional examples, the mass ratio of the oleic acid to the silane coupling agent is (0.5 - 1.5):1. For example, it can be 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1.0:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1, or 1.5:1. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0055] In some optional examples, the mass ratio of the silane coupling agent to the silicate solution is (1 - 2):20. For example, it can be 1:20, 1.1:20, 1.2:20, 1.3:20, 1.4:20, 1.5:20, 1.6:20, 1.7:20, 1.8:20, 1.9:20, or 2:20. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0056] In some optional examples, the mass fraction of the inorganic fiber in the modified silicate solution is 5 - 10 wt%. For example, it can be 5 wt%, 5.5 wt%, 6 wt%, 6.5 wt%, 7 wt%, 7.5 wt%, 8 wt%, 8.5 wt%, 9 wt%, 9.5 wt%, or 10 wt%. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0057] In some optional examples, the mass fraction of the vermiculite in the modified silicate solution is 10 - 15 wt%. For example, it can be 10 wt%, 10.5 wt%, 11 wt%, 11.5 wt%, 12 wt%, 12.5 wt%, 13 wt%, 13.5 wt%, 14 wt%, 14.5 wt%, or 15 wt%. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0058] In some alternative embodiments, the stirring time after adding the modified inorganic fiber / vermiculite mixture to the modified silicate solution is 40 to 60 minutes, such as 40 minutes, 42 minutes, 44 minutes, 46 minutes, 48 minutes, 50 minutes, 52 minutes, 54 minutes, 56 minutes, 58 minutes or 60 minutes. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0059] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0060] By introducing modified inorganic fibers and modified vermiculite, the present invention can significantly enhance the performance of the silicate binder: Vermiculite expands at high temperatures to form a porous structure, improving the heat insulation and fire resistance of the material. Inorganic fibers enhance the toughness and impact resistance of the binder, and their synergistic effect increases the crack resistance and durability of the material. Moreover, after phenolic resin-modified inorganic fibers and vermiculite, their dispersibility and compatibility can be enhanced, forming a stable composite material structure.

[0061] The silica aerogel is modified by carboxylated halloysite and carbon nanofibers. Halloysite has high-temperature resistance. Carboxylation modification can cause halloysite to undergo an esterification reaction with the hydroxyl groups on the surface of the aerogel, forming covalent bonds, thereby enhancing the compatibility and binding force between halloysite and the aerogel matrix, forming a more solid composite structure, making the overall structure more stable and heat-resistant, and reacting with the hydroxyl groups in the silicate binder to enhance the binding force. Carbon nanofibers improve the mechanical properties and thermal stability of the aerogel, evenly disperse heat, and reduce heat stress concentration.

[0062] Meanwhile, there is also a synergistic effect between the modified silica aerogel and the modified silicate binder. The low thermal conductivity of the aerogel combined with the fire resistance of the silicate binder enables the coating to provide better heat insulation and fire protection effects under high-temperature conditions; Carboxylated halloysite reacts with the hydroxyl groups in the silicate binder at the same time to form a strong crosslinked network, further enhancing the overall structural stability of the composite material. Description of the Drawings

[0063] Figure 1 It is a flow chart of the preparation method of the heat-insulating and fireproof coating containing aerogel composite modified silicate binder provided in Embodiments 1-4 of the present invention;

[0064] Figure 2 It is an infrared spectrogram of carboxylated halloysite and unmodified halloysite provided in Embodiment 1 of the present invention. Detailed Embodiments

[0065] The technical solution of the present invention will be described in detail below in conjunction with specific embodiments and their accompanying drawings. The embodiments described herein are specific specific embodiments of the present invention and are used to illustrate the concept of the present invention; these descriptions are all explanatory and exemplary, and should not be construed as limiting the embodiments of the present invention and the protection scope of the present invention. Except for the embodiments described herein, those skilled in the art can also adopt other obvious technical solutions based on the content disclosed in the claims and the specification of this application. These technical solutions include technical solutions that make any obvious substitutions and modifications to the embodiments described herein.

[0066] The chemical reagents used in the examples and comparative examples of the present invention are all commercially available products, and their brand names, specifications, manufacturers and other information are as follows:

[0067] Absolute ethanol: purity > 99%, purchased from Sinopharm Chemical Reagent Co., Ltd.;

[0068] Halloysite: purity > 99.3%, purchased from Xi'an Mingchuangda Biotechnology Co., Ltd.;

[0069] Methacrylic acid: purity > 98%, purchased from Sinopharm Chemical Reagent Co., Ltd.;

[0070] Sodium silicate: modulus 3.1, purchased from Dalian Qing'an Chemical Co., Ltd.;

[0071] Strong acid styrene cation exchange resin: purchased from Shanghai Huizhu Resin Co., Ltd.;

[0072] Sodium dodecyl sulfate: purchased from Sinopharm Chemical Reagent Co., Ltd.;

[0073] Nanometer carbon fiber: purity > 99%, purchased from Zhejiang Asia-America Nanotechnology Co., Ltd.;

[0074] Ammonia water: purchased from Sinopharm Chemical Reagent Co., Ltd.;

[0075] Trimethylchlorosilane: purity > 98%, purchased from Sinopharm Chemical Reagent Co., Ltd.;

[0076] n-Hexane: purity > 97%, purchased from Sinopharm Chemical Reagent Co., Ltd.;

[0077] Glass fiber: purchased from Shanghai Puzhensheng Technology Co., Ltd.;

[0078] Carbon fiber: purchased from Ningbo Luofei Nanotechnology Co., Ltd.;

[0079] Ceramic fiber: purchased from Suzhou Nijias Industrial Products Co., Ltd.;

[0080] Vermiculite: purchased from Shanghai Macklin Biochemical Co., Ltd.;

[0081] Phenolic resin: purchased from Sinopharm Chemical Reagent Co., Ltd.;

[0082] Sodium silicate: purchased from Hubei Chengfeng Chemical Co., Ltd.;

[0083] Aluminum silicate: purity > 99%, purchased from Sinopharm Chemical Reagent Co., Ltd.;

[0084] 3-aminopropyltriethoxysilane: purchased from Shanghai Macklin Biochemical Co., Ltd.;

[0085] 3-methylpropyltrichlorosilane: purchased from Shanghai Macklin Biochemical Co., Ltd.;

[0086] Oleic acid: purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.;

[0087] Expanded perlite: purchased from Shanghai Merry Biochemical Co., Ltd.;

[0088] Ceramic microspheres: purchased from Univar Chemicals (Shanghai) Co., Ltd.;

[0089] Dimethyl silicone oil: purchased from Sinopharm Chemical Reagent Co., Ltd.;

[0090] Polydimethylsiloxane: purchased from Sinopharm Chemical Reagent Co., Ltd.;

[0091] Sodium polyacrylate: purchased from Sinopharm Chemical Reagent Co., Ltd.;

[0092] Polypropylene glycol: purchased from Shanghai Macklin Biochemical Co., Ltd.;

[0093] Kaolin: purchased from Sinopharm Chemical Reagent Co., Ltd.;

[0094] Bentonite: purchased from Sinopharm Chemical Reagent Co., Ltd.;

[0095] Example 1

[0096] This example provides a building heat-insulating and fireproof coating containing an aerogel composite modified silicate binder and a preparation method thereof. Among them, the building heat-insulating and fireproof coating comprises the following components in parts by mass:

[0097] Modified silica aerogel 20 parts

[0098] Modified silicate binder 35 parts

[0099] Filler 20 parts

[0100] Auxiliary agent 10 parts

[0101] Deionized water 40 parts

[0102] As Figure 1As shown, the preparation method specifically includes the following steps:

[0103] S1: Add halloysite into absolute ethanol to obtain a halloysite dispersion, perform ultrasonic dispersion treatment for 28 min with an ultrasonic power of 1300 W, then add methacrylic acid, where the mass ratio of methacrylic acid to halloysite is 2.8:1, and keep the obtained mixed dispersion stirred at 80 °C for 3.4 h under nitrogen protection; wash and filter the mixed dispersion, and dry the obtained sample at 70 °C for 7.6 h to obtain carboxylated modified halloysite; dissolve sodium silicate in deionized water at room temperature, where the volume ratio of sodium silicate to deionized water is 4:1, and perform ion exchange through a strongly acidic styrene-based cation exchange resin to obtain a silicic acid solution. Add sodium dodecyl sulfate to the silicic acid solution to make the concentration of sodium dodecyl sulfate 16 mmol / L, stir until dissolved evenly to obtain a mixed solution. Add the carboxylated modified halloysite and nanofiber carbon to the mixed solution to obtain a precursor suspension, where the concentration of nanofiber carbon is 4 wt%, the mass ratio of carboxylated modified halloysite to sodium silicate is 0.3:1, perform mechanical stirring, with an ultrasonic dispersion time of 28 min and an ultrasonic frequency of 2000 W to form a suspension; adjust the pH of the suspension to 5.7 with 1 M ammonia water solution, then inject it into a polypropylene mold, let it stand, and after gel formation, age it at 35 °C for 22 h. Take it out of the mold, place it in a first ethanol aqueous solution with a volume fraction of 42% for the first immersion for 20 h, then transfer it to absolute ethanol for the second immersion for 23 h, and the time interval for changing the solution during the first immersion and the second immersion is 7.4 h to obtain a modified silica wet gel. Hydrophobically modify the modified silica wet gel, and then transfer it to a vacuum drying oven to dry at 48 °C for 21 h to obtain a modified silica aerogel.

[0104] S2: Put glass fiber and vermiculite into a phenolic resin ethanol solution to obtain an inorganic fiber / vermiculite dispersion. Among them, the mass ratio of phenolic resin to absolute ethanol in the phenolic resin ethanol solution is 1.8:10. Stir and impregnate for 2.7 h, and obtain a mixture after suction filtration. Heat-cure the mixture in an oven at 190 °C for 3.6 h to obtain a modified glass fiber / vermiculite mixture; dissolve aluminum silicate in a second ethanol aqueous solution. The volume ratio of absolute ethanol to deionized water in the second ethanol aqueous solution is 8.5:1.5, and the mass ratio of aluminum silicate to the second ethanol aqueous solution is 1:2.8 to obtain an aluminum silicate solution. Add 3-aminopropyltriethoxysilane and oleic acid to the aluminum silicate solution. Among them, the mass ratio of oleic acid to 3-aminopropyltriethoxysilane is 0.6:1, and the mass ratio of 3-aminopropyltriethoxysilane to the aluminum silicate solution is 1.8:20. Stir to obtain a modified aluminum silicate solution. Add the modified glass fiber / vermiculite mixture to the modified aluminum silicate solution and continuously stir. Among them, the mass fraction of glass fiber in the modified aluminum silicate solution is 6 wt%, and the mass fraction of vermiculite in the modified aluminum silicate solution is 10 wt%. Stir for 40 min to obtain a mixed suspension.

[0105] S3: Crush and grind the modified silica aerogel and add it to the mixed suspension in deionized water. After stirring evenly, add expanded perlite, ceramic microspheres, dimethyl silicone oil, sodium polyacrylate, and kaolin and continue to stir. Obtain the fireproof and heat-insulating coating.

[0106] Figure 2 The infrared spectrogram of the carboxylated modified halloysite and the unmodified halloysite provided in this example. As can be seen from the figure, the stretching vibration of Al-OH is at about 3620 cm -1 and 3670 cm -1 The strong characteristic bands at the position, and the characteristic band at 907 cm -1 is related to the bending vibration on the surface of halloysite. The characteristic bands at 1110 cm -1 and 1033 cm -1 are related to the stretching vibration and asymmetric stretching vibration of the Si-O-Si bond. Compared with the unmodified halloysite, the characteristic bands at 1690 cm -1 and 1570 cm -1 are respectively related to the stretching vibration of C=O of carboxylic acid and amide, which also strongly proves the successful carboxylation modification of halloysite.

[0107] Example 2

[0108] This example provides a building heat-insulating and fireproof coating containing an aerogel composite modified silicate binder and a preparation method. Among them, the building heat-insulating and fireproof coating includes the following components in parts by mass:

[0109] 40 parts of modified silica aerogel

[0110] 30 parts of modified silicate binder

[0111] 15 parts of filler

[0112] 5 parts of auxiliary agent

[0113] 45 parts of deionized water

[0114] As Figure 1 shown, the preparation method specifically includes the following steps:

[0115] S1: Add halloysite into absolute ethanol to obtain a halloysite dispersion, perform ultrasonic dispersion treatment for 23 min with an ultrasonic power of 1800 W, then add methacrylic acid, where the mass ratio of methacrylic acid to halloysite is 2.5:1, and keep the obtained mixed dispersion stirring at a constant temperature of 74 °C for 2.6 h under nitrogen protection; wash and filter the sample obtained from the mixed dispersion, and then dry the sample at 80 °C for 7 h to obtain carboxylated modified halloysite; dissolve sodium silicate in deionized water at room temperature, where the volume ratio of sodium silicate to deionized water is 3.3:1, and perform ion exchange through a strongly acidic styrene-based cation exchange resin to obtain a silicic acid solution. Add sodium dodecyl sulfate to the silicic acid solution, where the concentration of sodium dodecyl sulfate is 14.8 mmol / L, and stir until it is uniformly dissolved to obtain a mixed solution. Add the carboxylated modified halloysite and carbon nanofibers to the mixed solution to obtain a precursor suspension, where the concentration of carbon nanofibers is 1.8 wt%, and the mass ratio of carboxylated modified halloysite to sodium silicate is 0.15:1. Perform mechanical stirring with an ultrasonic dispersion time of 23 min and an ultrasonic frequency of 1500 W to form a suspension; use 1.5 M ammonia water solution to adjust the pH of the suspension to 5.3, then inject it into a polypropylene mold, let it stand, and after gel formation, age it at 28 °C for 25 h. Take it out of the mold, place it in a first ethanol aqueous solution with a volume fraction of 60% for the first immersion for 18 h, and then transfer it to absolute ethanol for the second immersion for 24 h. The time interval for changing the solution during the first immersion and the second immersion is 6 h to obtain a modified silica wet gel. Perform hydrophobic modification on the modified silica wet gel, and then transfer it to a vacuum drying oven and dry it at 43 °C for 20 h to obtain modified silica aerogel.

[0116] S2: Put ceramic fiber and vermiculite into a phenolic resin ethanol solution to obtain an inorganic fiber / vermiculite dispersion. Among them, the mass ratio of phenolic resin to absolute ethanol in the phenolic resin ethanol solution is 1.3:10. Stir and impregnate for 1.2 h, and obtain a mixture after suction filtration. Heat-cure the mixture in an oven at 170 °C for 2.3 h to obtain a modified ceramic fiber / vermiculite mixture; dissolve sodium silicate in a second ethanol aqueous solution. The volume ratio of absolute ethanol to deionized water in the second ethanol aqueous solution is 7:3, and the mass ratio of sodium silicate to the second ethanol aqueous solution is 1:2.2 to obtain a sodium silicate solution. Add 3-methylpropyltrichlorosilane and oleic acid to the sodium silicate solution. Among them, the mass ratio of oleic acid to 3-methylpropyltrichlorosilane is 0.8:1, and the mass ratio of 3-methylpropyltrichlorosilane to the sodium silicate solution is 1.4:20. Stir to obtain a modified sodium silicate solution. Add the modified ceramic fiber / vermiculite mixture to the modified sodium silicate solution and continuously stir. Among them, the mass fraction of ceramic fiber in the modified sodium silicate solution is 8 wt%, and the mass fraction of vermiculite in the modified sodium silicate solution is 11 wt%. Stir for 50 min to obtain a mixed suspension.

[0117] S3: Crush and grind the modified silica aerogel, add it to the mixed suspension in deionized water, stir evenly, and then add ceramic microspheres, dimethyl silicone oil, polypropylene glycol, and bentonite and continue to stir. Obtain the fireproof and heat-insulating coating.

[0118] Example 3

[0119] This example provides a building heat-insulating and fireproof coating containing an aerogel composite modified silicate binder and a preparation method. Among them, the building heat-insulating and fireproof coating includes the following components in parts by mass:

[0120] Modified silica aerogel: 30 parts

[0121] Modified silicate binder: 50 parts

[0122] Filler: 10 parts

[0123] Auxiliary agent: 8 parts

[0124] Deionized water: 50 parts

[0125] As Figure 1 shown, the preparation method specifically includes the following steps:

[0126] S1: Add halloysite into absolute ethanol to obtain a halloysite dispersion, and perform ultrasonic dispersion treatment for 30 min with an ultrasonic power of 1000 W. Subsequently, add methacrylic acid, where the mass ratio of methacrylic acid to halloysite is 3:1. The obtained mixed dispersion is stirred at a constant temperature of 78 °C for 4 h under nitrogen protection; the sample obtained after washing and suction filtration of the mixed dispersion is dried at 73 °C for 8 h to obtain carboxylated modified halloysite; dissolve sodium silicate in deionized water at room temperature, where the volume ratio of sodium silicate to deionized water is 3.8:1, and perform ion exchange through a strongly acidic styrene-based cation exchange resin to obtain a silicic acid solution. Add sodium dodecyl sulfate to the silicic acid solution, where the concentration of sodium dodecyl sulfate is 15.6 mmol / L, and stir until dissolved uniformly to obtain a mixed solution. Add the carboxylated modified halloysite and carbon nanofibers to the mixed solution to obtain a suspension precursor, where the concentration of carbon nanofibers is 3.5 wt%, the mass ratio of carboxylated modified halloysite to sodium silicate is 0.2:1, mechanically stir, and the ultrasonic dispersion time is 30 min with an ultrasonic frequency of 1000 W to form a suspension; adjust the pH of the suspension to 6.0 with 1.8 M ammonia water solution, then inject it into a polypropylene mold, let it stand, and after gel formation, age it at 32 °C for 30 h. Take it out of the mold and place it in a first ethanol aqueous solution with a volume fraction of 52% for the first immersion for 21 h, then transfer it to absolute ethanol for the second immersion for 19 h. The solution replacement time interval during the first immersion and the second immersion is 6.4 h to obtain a modified silica wet gel. Hydrophobically modify the modified silica wet gel, and then transfer it to a vacuum drying oven and dry it at 40 °C for 26 h to obtain a modified silica aerogel.

[0127] S2: Put glass fiber and vermiculite into a phenolic resin ethanol solution to obtain an inorganic fiber / vermiculite dispersion, where the mass ratio of phenolic resin to absolute ethanol in the phenolic resin ethanol solution is 2:10, stir and impregnate for 1 h, and obtain a mixture after suction filtration. Heat-cure the mixture in an oven at 200 °C for 2 h to obtain a modified glass fiber / vermiculite mixture; dissolve sodium silicate in a second ethanol aqueous solution, where the volume ratio of absolute ethanol to deionized water in the second ethanol aqueous solution is 8:2, and the mass ratio of sodium silicate to the second ethanol aqueous solution is 1:2 to obtain a sodium silicate solution. Add 3-methylpropyltrichlorosilane and oleic acid to the sodium silicate solution, where the mass ratio of oleic acid to 3-methylpropyltrichlorosilane is 1.5:1 and the mass ratio of 3-methylpropyltrichlorosilane to the sodium silicate solution is 1:20, stir to obtain a modified sodium silicate solution. Add the modified glass fiber / vermiculite mixture to the modified sodium silicate solution and continuously stir, where the mass fraction of glass fiber in the modified sodium silicate solution is 10 wt% and the mass fraction of vermiculite in the modified sodium silicate solution is 13 wt%. Stir for 45 min to obtain a mixed suspension.

[0128] S3: After crushing and grinding the modified silica aerogel, add the mixed suspension into deionized water. After stirring evenly, add expanded perlite, ceramic microspheres, dimethyl silicone oil, sodium polyacrylate, and kaolin and continue stirring. Obtain the fireproof and heat-insulating coating.

[0129] Example 4

[0130] This example provides a building heat-insulating and fireproof coating containing an aerogel composite modified silicate binder and a preparation method thereof. Among them, the building heat-insulating and fireproof coating includes the following components in parts by mass:

[0131] Modified silica aerogel: 38 parts

[0132] Modified silicate binder: 48 parts

[0133] Filler: 30 parts

[0134] Auxiliary agent: 6 parts

[0135] Deionized water: 48 parts

[0136] As Figure 1 shown, the preparation method specifically includes the following steps:

[0137] S1: Add halloysite into absolute ethanol to obtain a halloysite dispersion, and perform ultrasonic dispersion treatment for 20 min with an ultrasonic power of 2000 W. Subsequently, add methacrylic acid, where the mass ratio of methacrylic acid to halloysite is 2:1, and keep the obtained mixed dispersion stirred at 70 °C for 2 h under nitrogen protection; wash and filter the mixed dispersion, and dry the obtained sample at 90 °C for 6 h to obtain carboxylated modified halloysite; dissolve sodium silicate in deionized water at room temperature, where the volume ratio of sodium silicate to deionized water is 3:1, and perform ion exchange through a strongly acidic styrene-based cation exchange resin to obtain a silicic acid solution. Add sodium dodecyl sulfate to the silicic acid solution to make the concentration of sodium dodecyl sulfate 14 mmol / L, and stir until dissolved uniformly to obtain a mixed solution. Add the carboxylated modified halloysite and carbon nanofibers to the mixed solution to obtain a precursor suspension, where the concentration of carbon nanofibers is 1 wt%, the mass ratio of carboxylated modified halloysite to sodium silicate is 0.3:1, stir mechanically, with an ultrasonic dispersion time of 20 min and an ultrasonic frequency of 1800 W, to form a suspension; adjust the pH of the suspension to 5.0 with 2 M ammonia water solution, then inject it into a polypropylene mold, let it stand, and after gel formation, age it at 25 °C for 20 h. Take it out of the mold, place it in a first ethanol aqueous solution with a volume fraction of 40% for the first immersion for 24 h, then transfer it to absolute ethanol for the second immersion for 18 h. The solution replacement time interval during the first immersion and the second immersion is 8 h to obtain a modified silica wet gel. Hydrophobically modify the modified silica wet gel, and then transfer it to a vacuum drying oven and dry it at 50 °C for 24 h to obtain a modified silica aerogel.

[0138] S2: Put carbon fiber and vermiculite into a phenolic resin ethanol solution to obtain an inorganic fiber / vermiculite dispersion, where the mass ratio of phenolic resin to absolute ethanol in the phenolic resin ethanol solution is 1:10, stir and impregnate for 3 h, and filter to obtain a mixture. Heat-cure the mixture in an oven at 150 °C for 4 h to obtain a modified carbon fiber / vermiculite mixture; dissolve aluminum silicate in a second ethanol aqueous solution, where the volume ratio of absolute ethanol to deionized water in the second ethanol aqueous solution is 9:1, and the mass ratio of aluminum silicate to the second ethanol aqueous solution is 1:3, to obtain an aluminum silicate solution. Add 3-aminopropyltriethoxysilane and oleic acid to the aluminum silicate solution, where the mass ratio of oleic acid to 3-aminopropyltriethoxysilane is 0.5:1 and the mass ratio of 3-aminopropyltriethoxysilane to the aluminum silicate solution is 1:20, stir to obtain a modified aluminum silicate solution. Add the modified carbon fiber / vermiculite mixture to the modified aluminum silicate solution and keep stirring, where the mass fraction of carbon fiber in the modified aluminum silicate solution is 5 wt% and the mass fraction of vermiculite in the modified aluminum silicate solution is 15 wt%, and stir for 60 min to obtain a mixed suspension.

[0139] S3: After crushing and grinding the modified silica aerogel, add it and the mixed suspension into deionized water. After stirring evenly, add expanded perlite, ceramic microspheres, polydimethylsiloxane, polypropylene glycol, and kaolin and continue stirring to obtain the fireproof and heat-insulating coating.

[0140] Comparative Example 1

[0141] This example provides a heat-insulating and fireproof coating, which is different from Example 1 in that the mass fraction of the modified silica aerogel in the heat-insulating and fireproof coating is adjusted to 45 parts. Compared with Example 1, the mass fraction of the modified silica aerogel in this example is increased by 25 parts, and the increased 25 parts are proportionally deducted from the mass fractions of the modified silicate binder, filler, and additives, so that the proportion of the mass fractions of other components except the modified silica aerogel remains unchanged. The mass fractions of the components of the adjusted heat-insulating and fireproof coating are as follows:

[0142] Modified silica aerogel 50 parts

[0143] Modified silicate binder 25 parts

[0144] Filler 14.29 parts

[0145] Additive 7.14 parts

[0146] Deionized water 28.57 parts

[0147] Other process parameters and operating conditions are exactly the same as those in Example 1.

[0148] Comparative Example 2

[0149] This example provides a heat-insulating and fireproof coating, which is different from Example 1 in that the mass fraction of the modified silica aerogel in the heat-insulating and fireproof coating is adjusted to 10 parts. Compared with Example 1, the mass fraction of the modified silica aerogel in this example is reduced by 10 parts, and the reduced 10 parts are proportionally supplemented to the mass fractions of the modified silicate binder, filler, and additives, so that the proportion of the mass fractions of other components except the modified silica aerogel remains unchanged. The mass fractions of the components of the adjusted heat-insulating and fireproof coating are as follows:

[0150] Modified silica aerogel 10 parts

[0151] Modified silicate binder 38.33 parts

[0152] Filler 21.90 parts

[0153] Additive 10.95 parts

[0154] Deionized water 43.80 parts

[0155] Other process parameters and operating conditions are exactly the same as those in Example 1.

[0156] Comparative Example 3

[0157] This example provides a heat-insulating and fireproof coating, which is different from Example 1 in that the mass fraction of the modified silicate binder in the heat-insulating and fireproof coating is adjusted to 60 parts. Compared with Example 1, the mass fraction of the modified silicate binder in this example is increased by 25 parts, and the increased 25 parts are deducted proportionally from the mass fractions of the modified silica aerogel, filler, and additive, so that the proportion of the mass fractions of other components except the modified silicate binder remains unchanged. The mass fractions of the components of the adjusted heat-insulating and fireproof coating are as follows:

[0158] Modified silica aerogel 14.44 parts

[0159] Modified silicate binder 60 parts

[0160] Filler 14.44 parts

[0161] Additive 7.22 parts

[0162] Deionized water 28.89 parts

[0163] Other process parameters and operating conditions are exactly the same as those in Example 1.

[0164] Comparative Example 4

[0165] This example provides a heat-insulating and fireproof coating, which is different from Example 1 in that the mass fraction of the modified silicate binder in the heat-insulating and fireproof coating is adjusted to 20 parts. Compared with Example 1, the mass fraction of the modified silicate binder in this example is decreased by 15 parts, and the decreased 15 parts are supplemented proportionally to the mass fractions of the modified silica aerogel, filler, and additive, so that the proportion of the mass fractions of other components except the modified silicate binder remains unchanged. The mass fractions of the components of the adjusted heat-insulating and fireproof coating are as follows:

[0166] Modified silica aerogel 23.33 parts

[0167] Modified silicate binder 20 parts

[0168] Filler 23.33 parts

[0169] Additive 11.67 parts

[0170] Deionized water 46.67 parts

[0171] Other process parameters and operating conditions are exactly the same as those in Example 1.

[0172] The performance of the heat-insulating and fireproof coatings of the above Examples 1-4 and Comparative Examples 1-4 was tested, and the specific process is as follows:

[0173] A Fourier transform infrared spectrometer was used to characterize the functional groups in the molecular structures of the carboxylated modified halloysite and unmodified halloysite in Example 1;

[0174] According to the national standard GB / T 10295-2008, the thermal conductivity of Examples 1-4 and Comparative Examples 1-4 was tested respectively;

[0175] According to the national standard GB / T8624-2012, the fire protection grades of Examples 1-4 and Comparative Examples 1-4 were tested respectively;

[0176] According to the national standard GB / T23445-2009, the bond strength of Examples 1-4 and Comparative Examples 1-4 was tested respectively;

[0177] According to the national standard GB / T13893-2008, the aging resistance of Examples 1-4 and Comparative Examples 1-4 was tested respectively;

[0178] All the test results are shown in Table 1:

[0179] Table 1: Performance test of the heat-insulating and fireproof coatings of Examples 1-4 and Comparative Examples 1-4

[0180]

[0181] It can be seen from the data in Table 1 that the coatings prepared in Examples 1-4 provided by the present invention have good heat-insulating performance and fireproof performance.

[0182] It can be seen from the test results of Example 1, Comparative Example 1 and Comparative Example 2 that when the mass fraction of the modified silica aerogel in the coating is in the range of 20-40 parts, the excellent heat-insulating performance of the silica aerogel can significantly improve the heat-insulating effect of the coating. Among them, the carboxylated modified halloysite can also react with the hydroxyl groups in the silicate binder, so that the aerogel and the binder matrix form a tight combination, thereby improving the mechanical strength and other properties of the binder; however, when the addition amount of the modified silica aerogel is too much, due to the brittle structure of the aerogel, too high content may lead to a decrease in the mechanical strength of the coating, affecting its service life in harsh environments; at the same time, it may lead to a decrease in the adhesion between the coating and the substrate, thus affecting the durability and stability of the coating.

[0183] From the test results of Example 1, Comparative Example 3 and Comparative Example 4, it can be seen that when the mass fraction of the modified silicate binder in the coating is in the range of 30-50 parts, the heat insulation and fireproof performance of the silicate binder can be enhanced by the modification of vermiculite and inorganic fibers. Increasing the content of the silicate binder in the coating can enhance the bonding strength of the coating, improve the adhesion between the coating and the substrate, and improve its durability. However, too high a silicate content may cause the coating layer to become too hard, brittle and prone to cracking, thus affecting the use effect and durability of the coating.

[0184] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of within the technical scope disclosed by the present invention by those skilled in the art all fall within the protection scope and the disclosure scope of the present invention.

Claims

1. A preparation method of a building heat-insulating and fireproof coating containing an aerogel composite modified silicate binder, characterized in that The preparation method includes: S1: Adding halloysite into absolute ethanol to obtain a halloysite dispersion, ultrasonically dispersing it, and then adding methacrylic acid. The resulting mixed dispersion is stirred under nitrogen protection at a constant temperature; the sample obtained after washing and suction filtration of the mixed dispersion is dried to obtain carboxylated modified halloysite; dissolving sodium silicate in deionized water at room temperature and performing ion exchange through a strongly acidic styrene-based cation exchange resin to obtain a silicic acid solution. Adding sodium dodecyl sulfate to the silicic acid solution and stirring until it is uniformly dissolved to obtain a mixed solution. Adding the carboxylated modified halloysite and nanofiber carbon into the mixed solution to obtain a precursor suspension, and ultrasonically dispersing it to form a suspension; adjusting the pH of the suspension with an ammonia water solution, injecting it into a polypropylene mold, standing, aging after gel formation, taking it out of the mold, placing it in a first ethanol aqueous solution for the first immersion, and then transferring it into absolute ethanol for the second immersion to obtain a modified silica wet gel. Hydrophobically modifying the modified silica wet gel and then transferring it into a vacuum drying oven for drying to obtain a modified silica aerogel; S2: Putting inorganic fibers and vermiculite into a phenolic resin ethanol solution to obtain an inorganic fiber / vermiculite dispersion, stirring and impregnating it, and obtaining a mixture after suction filtration. Thermally curing the mixture in an oven to obtain a modified inorganic fiber / vermiculite mixture; dissolving a silicate in a second ethanol aqueous solution, and the mass ratio of the silicate to the second ethanol aqueous solution is 1:(2 - 3) to obtain a silicate solution. Adding a silane coupling agent and oleic acid to the silicate solution, and the mass ratio of oleic acid to the silane coupling agent is (0.5 - 1.5):1, and the mass ratio of the silane coupling agent to the silicate solution is (1 - 2):

20. Stirring to obtain a modified silicate solution, adding the modified inorganic fiber / vermiculite mixture to the modified silicate solution and continuously stirring to obtain a mixed suspension, which is a modified silicate binder; S3: Crushing and grinding the modified silica aerogel and adding it to the mixed suspension into deionized water. After stirring evenly, adding a filler and an auxiliary agent and continuing to stir to obtain a heat-insulating and fireproof coating; the auxiliary agent is an antifoaming agent, a dispersant, and a thickening agent; The heat-insulating and fireproof coating includes the following components in parts by mass: 20 - 40 parts of modified silica aerogel; 30 - 50 parts of modified silicate binder; 10 - 30 parts of filler; 5 - 10 parts of auxiliary agent; 40 - 50 parts of deionized water.

2. The preparation method of a building heat-insulating and fireproof coating containing an aerogel composite modified silicate binder according to claim 1, characterized in that, In the above S1, The ultrasonic time of the halloysite dispersion is 20 - 30 min; The ultrasonic frequency of the halloysite dispersion is 1000 - 2000 W; The mass ratio of methacrylic acid to halloysite is (2 - 3):1; The constant temperature at which the mixed dispersion is located is 70 - 80 °C; The stirring time of the mixed dispersion is 2 - 4 h; The drying temperature of the sample is 70 - 90 °C; The drying time of the sample is 6 - 8 h.

3. The preparation method of a building heat-insulating and fireproof coating containing an aerogel composite modified silicate binder according to claim 1, characterized in that, In the above S1, The volume ratio of sodium silicate to deionized water is (3 - 4):1; The concentration of sodium dodecyl sulfate added to the silicic acid solution is 14 - 16 mmol / L; The concentration of nano-carbon fiber added to the mixed solution is 1-4 wt%. The mass ratio of carboxylated modified halloysite to sodium silicate added to the mixed solution is (0.1-0.3):

1. The ultrasonic treatment time of the suspension precursor is 20-30 min. The ultrasonic treatment frequency of the suspension precursor is 1000-2000 W.

4. The preparation method of a building heat-insulating and fireproof coating containing an aerogel composite modified silicate binder according to claim 1, characterized in that, In S1, The concentration of the ammonia water solution is 1-2 M. The pH of the suspension is adjusted to 5.0-6.0 with the ammonia water solution. The gel aging temperature is 25-35 °C. The gel aging time is 20-30 h. The volume fraction of the first ethanol aqueous solution is 40-60%. The soaking time for the first soaking and the second soaking is 18-24 h. The time interval for replacing the solution during the first soaking and the second soaking is 6-8 h. The vacuum drying temperature of the modified silica wet gel is 40-50 °C. The vacuum drying time of the modified silica wet gel is 18-24 h.

5. The preparation method of a building heat-insulating and fireproof coating containing an aerogel composite modified silicate binder according to claim 1, characterized in that, In S2, The mass ratio of phenolic resin to absolute ethanol in the phenolic resin ethanol solution is (1-2):

10. The inorganic fiber is glass fiber, carbon fiber or ceramic fiber. The stirring and impregnation time of the inorganic fiber / vermiculite dispersion is 1-3 h. The temperature of the thermal curing treatment of the mixture is 150-200 °C. The time of the thermal curing treatment of the mixture is 2-4 h. The volume ratio of absolute ethanol to deionized water in the second ethanol aqueous solution is (7-9):(3-1). The silane coupling agent is 3-aminopropyltriethoxysilane. The mass fraction of the inorganic fiber in the modified silicate solution is 5-10 wt%. The mass fraction of the vermiculite in the modified silicate solution is 10-15 wt%. The stirring time after adding the modified inorganic fiber / vermiculite mixture to the modified silicate solution is 40-60 min.

6. The preparation method of a building heat-insulating and fireproof coating containing an aerogel composite modified silicate binder according to claim 1, characterized in that In S3, The defoaming agent is polydimethylsiloxane. The dispersant is sodium polyacrylate and / or polypropylene glycol. The thickener is kaolin and / or bentonite.

7. An architectural heat-insulating and fireproof coating containing an aerogel composite modified silicate binder prepared by the preparation method according to any one of claims 1 to 6, characterized in that The building thermal insulation and fireproof coating comprises the following components in parts by mass: Modified silica aerogel 20-40 parts; Modified silicate binder 30-50 parts; Filler 10-30 parts; Auxiliary agent 5-10 parts; Deionized water 40-50 parts.

8. An architectural heat-insulating and fireproof coating containing an aerogel composite modified silicate binder according to claim 7, characterized in that The silicate in the modified silicate binder is sodium silicate and / or aluminum silicate.

9. The building heat-insulating and fireproof coating containing the aerogel composite modified silicate binder according to claim 7, wherein, The filler is any one or a combination of at least two of expanded perlite, ceramic microspheres and ceramic fibers.

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