An aerogel composite thermal insulation coating and its preparation method

Abstract

The present invention relates to the technical field of thermal insulation materials, and specifically discloses an aerogel composite thermal insulation coating and a preparation method thereof. In the composite emulsion provided by the present invention, the monomer raw materials are selected from 4-vinylphenylboronic acid, styrene, and acrylate. The polystyrene structure and the alkyl long-chain structure of polyacrylate formed by polymerization have strong hydrophobic properties, improving the hydrophobicity of the coating. At the same time, the polystyrene structure can also endow the coating with a certain thermal insulation effect. The boric acid groups in 4-vinylphenylboronic acid form a B-O-B cross-linked network structure at high temperatures, which can form a borate glass layer with zirconia in the modified montmorillonite, improving the density and thermal stability of the carbon layer, and further improving the flame retardant effect of the coating. And by modifying the montmorillonite, the hydrophobicity and flame retardant effect of the coating are further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of thermal insulation materials, and particularly relates to an aerogel composite thermal insulation coating and a preparation method thereof. Background Art

[0002] With the continuous improvement of building energy conservation requirements, external wall thermal insulation technology has become a key research direction in the field of modern architecture. Traditional external wall thermal insulation systems mostly use inorganic or organic thermal insulation boards such as polystyrene foam boards and rock wool boards, which are attached to the building facade by bonding or mechanical fixing methods; although such materials have certain thermal insulation performance, their construction processes have problems such as complex procedures and difficult joint treatment, which are prone to cause the cold and heat bridge effect. In addition, defects such as poor impact resistance and easy aging and shedding of plate materials not only affect the building appearance, but also pose safety hazards of high-altitude falling objects. In recent years, some projects have tried to use on-site spraying thermal insulation materials such as foamed cement, but there are still problems such as uneven thickness and drying shrinkage cracking, which restrict their large-scale application.

[0003] Currently, the thermal insulation coatings for external wall panels mainly improve performance from the aspects of the selection of emulsions, fillers, and additives and their mutual dispersion and stability. However, such coatings often face the contradiction of single functionality and the difficulty of synergistically improving mechanical strength and thermal insulation performance. For example, Chinese Patent Document ZL202211645360.8 discloses an interior wall thermal insulation coating and a preparation method thereof. An interior wall thermal insulation coating: including 40-60 parts of silicone-acrylic emulsion, 10-25 parts of modified reed fiber, 8-12 parts of fly ash hollow microspheres, 10-12 parts of modified vitrified microspheres, 5-8 parts of epoxy resin, 2-4 parts of thickener, 0.8-1.5 parts of dodecyl alcohol ester, and 1-1.2 parts of potassium methyl silicate. The prepared coating can be used for the construction of interior wall thermal insulation coatings, and it has the advantages of strong water resistance, small thermal conductivity, and good heat preservation, but its flame retardant performance still needs to be further improved. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide an aerogel composite thermal insulation coating and a preparation method thereof.

[0005] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0006] An aerogel composite thermal insulation coating, in parts by weight, comprises raw materials of the following components: 80-120 parts of composite emulsion, 10-20 parts of aerogel, 8-15 parts of modified montmorillonite, 5-10 parts of titanium dioxide, 5-10 parts of epoxy resin, 1-5 parts of dispersant, 1-3 parts of dodecyl alcohol ester, and 1-3 parts of sodium methyl silicate.

[0007] In the technical solution disclosed by the present invention, the amount of the composite emulsion is 80-120 parts. For example, 80 parts, 85 parts, 90 parts, 95 parts, 100 parts, 105 parts, 110 parts, 115 parts, 120 parts can be selected, but the listed values are not limitative, and other unlisted values within the numerical range are equally applicable.

[0008] Specifically, the preparation method of the composite emulsion is as follows: Sodium dodecyl sulfate, nonylphenol polyoxyethylene ether and tert-dodecyl mercaptan are added to deionized water, stirred evenly, and nitrogen is introduced to expel air. Then, 4-vinylbenzeneboronic acid, styrene and acrylate are added thereto, and the mixture is stirred and heated to 55-65 °C. Subsequently, an initiator is added for reaction. After the reaction is completed, it is cooled to room temperature to obtain the composite emulsion.

[0009] Preferably, the mass ratio of sodium dodecyl sulfate, nonylphenol polyoxyethylene ether, tert-dodecyl mercaptan, deionized water, 4-vinylbenzeneboronic acid, styrene, acrylate and initiator is 1-3:1-3:2-4:100-150:10-15:20-25:15-20:1-2.

[0010] Preferably, the initiator is selected from persulfates, such as sodium persulfate, potassium persulfate or ammonium persulfate can be selected.

[0011] Preferably, the acrylate has ≥10 carbon atoms. For example, dodecyl acrylate, hexadecyl acrylate or octadecyl acrylate can be selected, but it is not limited to the several listed above.

[0012] Preferably, the reaction time is 2-5 h. For example, 2 h, 2.5 h, 3 h, 3.5 h, 4 h, 4.5 h, 5 h can be selected, but the listed values are not limitative, and other unlisted values within the numerical range are equally applicable.

[0013] In the composite emulsion provided by the present invention, the monomer raw materials are selected from 4-vinylbenzeneboronic acid, styrene and acrylate. The formed polystyrene structure and the alkyl long-chain structure of polyacrylate have strong hydrophobic properties, which improve the hydrophobicity of the coating. At the same time, the polystyrene structure can also endow the coating with a certain heat preservation effect. The boric acid group in 4-vinylbenzeneboronic acid forms a B-O-B cross-linked network structure at high temperature, which can form a borate glass layer with zirconia in the modified montmorillonite, improving the denseness and thermal stability of the carbon layer, and further improving the flame retardant effect of the coating.

[0014] In the technical solution disclosed by the present invention, the amount of the aerogel is 10-20 parts. For example, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts can be selected, but the listed values are not limitative, and other unlisted values within the numerical range are equally applicable.

[0015] Specifically, the aerogel is selected from silica aerogels. Due to the unique nanoporous structure and low thermal conductivity of silica aerogels, the heat insulation effect of the coating is thereby improved.

[0016] In the technical solution disclosed in the present invention, the amount of the modified montmorillonite is 8 - 15 parts. For example, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts can be selected, but it is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0017] Specifically, the preparation method of the modified montmorillonite is as follows:

[0018] S1. Add montmorillonite to an acid solution, heat and stir, then filter, wash, dry, and calcine to obtain pretreated montmorillonite.

[0019] S2. Add zirconium nitrate to deionized water, stir to dissolve, then add the pretreated montmorillonite thereto, stir evenly, adjust the pH of the solution to 8 - 10, and dry and calcine to obtain a montmorillonite composite material.

[0020] S3. Disperse the montmorillonite composite material in an ethanol aqueous solution, then add 1,1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,8 - heptadecafluorooctyltrimethoxysilane thereto, stir, and then filter, wash, and dry to obtain the modified montmorillonite.

[0021] Preferably, in step S1, the acid solution is selected from sulfuric acid solution, nitric acid solution or hydrochloric acid solution, and the concentration of the acid solution is 0.5 - 2 mol / L. For example, 0.5 mol / L, 1 mol / L, 1.5 mol / L, 2 mol / L can be selected, but it is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0022] Preferably, in step S1, the temperature of heating and stirring is 60 - 90 °C. For example, 60 °C, 65 °C, 70 °C, 75 °C, 80 °C, 85 °C, 90 °C can be selected; the time of heating and stirring is 1 - 3 h. For example, 1 h, 1.5 h, 2 h, 2.5 h, 3 h can be selected, but it is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0023] Preferably, in step S1, the calcination temperature is 500 - 600 °C. For example, 500 °C, 510 °C, 520 °C, 530 °C, 540 °C, 550 °C, 600 °C can be selected; the calcination time is 2 - 4 h. For example, 2 h, 2.5 h, 3 h, 3.5 h, 4 h can be selected, but it is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0024] Preferably, in step S2, the mass ratio of zirconium nitrate to pretreated montmorillonite is 2-4:10-15, for example, 2:10, 2:12, 2:15, 3:10, 3:12, 3:15, 4:10, 4:12, 4:15 can be selected, but is not limited to the listed values, and other values not listed within the numerical range are also applicable.

[0025] Preferably, in step S2, the calcination temperature is 500-600°C, for example, 500°C, 510°C, 520°C, 530°C, 540°C, 550°C, and 600°C can be selected; the calcination time is 2-4h, for example, 2h, 2.5h, 3h, 3.5h, and 4h can be selected, but is not limited to the listed values, and other unlisted values within the numerical range are also applicable.

[0026] Preferably, in step S3, the mass ratio of the montmorillonite composite material to tridecafluorooctyltrimethoxysilane is 10-15:1-3, for example, 10:1, 10:2, 10:3, 12:1, 12:2, 12:3, 15:1, 15:2, 15:3 can be selected, but is not limited to the listed values, and other unlisted values within the numerical range are also applicable.

[0027] In the present invention, montmorillonite is first treated with an acid solution to dissolve metal ions between montmorillonite layers in the form of soluble salts, thereby unblocking the pores. The layered structure of the montmorillonite and the nanopores of the aerogel form a "micrometer-nanometer" dual-scale barrier, extending the heat conduction path, and reducing the thermal conductivity of the coating. Subsequently, zirconium oxide is loaded on the surface and between the layers of the montmorillonite. The polystyrene structure and boric acid groups in the zirconium oxide and the composite emulsion act synergistically to jointly improve the flame retardant effect of the coating. At the same time, zirconium oxide has a lower thermal conductivity, and filling it between the layers of the montmorillonite further extends the heat conduction path and further reduces the thermal conductivity of the coating. Then, tridecafluorooctyltrimethoxysilane is used to treat the surface of the montmorillonite composite material, and the hydrophobicity of the coating is further improved by introducing fluorine-containing groups.

[0028] In the technical solution disclosed in the present invention, the number of parts of titanium dioxide is 5-10 parts, for example, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, and 10 parts can be selected, but it is not limited to the listed values, and other unlisted values within the numerical range are also applicable.

[0029] The titanium dioxide used in the present invention is rutile titanium dioxide, which has a high refractive index and can effectively reflect visible light and infrared light in sunlight, thereby reducing heat absorption. Titanium dioxide and other functional fillers such as aerogel and modified montmorillonite work synergistically to further improve the thermal insulation performance of the coating.

[0030] In the technical solution disclosed by the present invention, the amount of epoxy resin is 5-10 parts. For example, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts can be selected, but it is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0031] In the technical solution disclosed by the present invention, the amount of the dispersant is 1-5 parts. For example, 1 part, 2 parts, 3 parts, 4 parts, 5 parts can be selected, but it is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0032] Specifically, the dispersant is selected from polyphosphates.

[0033] In the technical solution disclosed by the present invention, the amount of dodecyl alcohol ester is 1-3 parts. For example, 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts can be selected, but it is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0034] In the technical solution disclosed by the present invention, the amount of sodium methyl silicate is 1-3 parts. For example, 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts can be selected, but it is not limited to the listed values, and other unlisted values within the numerical range are equally applicable.

[0035] The present invention also provides a method for preparing the above-mentioned aerogel composite thermal insulation coating, which includes the following steps: mixing the composite emulsion and epoxy resin evenly to obtain a mixed solution, and then adding aerogel, modified montmorillonite, titanium dioxide, dispersant, dodecyl alcohol ester and sodium methyl silicate to the mixed solution and mixing evenly to obtain the aerogel composite thermal insulation coating.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] (1) In the composite emulsion provided by the present invention, the monomer raw materials are selected from 4-vinylphenylboronic acid, styrene and acrylate. The polystyrene structure and the alkyl long-chain structure of polyacrylate formed by polymerization have strong hydrophobic characteristics, which improve the hydrophobicity of the coating. At the same time, the polystyrene structure can also endow the coating with a certain heat preservation effect. The boric acid group in 4-vinylphenylboronic acid forms a B-O-B cross-linked network structure at high temperature, which can form a borate glass layer with zirconia in the modified montmorillonite, improving the density and thermal stability of the carbon layer, and further improving the flame retardant effect of the coating.

[0038] (2) In the present invention, montmorillonite is first treated with an acid solution to dissolve the metal ions between the montmorillonite layers in the form of soluble salts, thereby unblocking the pores. The layered structure of the montmorillonite and the nanopores of the aerogel form a "micrometer-nanometer" dual-scale barrier, extending the heat conduction path and reducing the thermal conductivity of the coating. Subsequently, zirconium oxide is loaded on the surface and between the layers of the montmorillonite. The zirconium oxide and the polystyrene structure and boric acid groups in the composite emulsion act synergistically to improve the flame retardant effect of the coating. At the same time, zirconium oxide has a lower thermal conductivity. Filling it between the layers of the montmorillonite further extends the heat conduction path and further reduces the thermal conductivity of the coating. The montmorillonite composite material is then surface treated with tridecafluorooctyltrimethoxysilane to further improve the hydrophobicity of the coating by introducing fluorine-containing groups. DETAILED DESCRIPTION

[0039] The present invention is further described in detail below through specific preferred embodiments, but the present invention is not limited to the following embodiments.

[0040] It should be noted that, unless otherwise specified, the chemical reagents involved in the present invention were purchased through commercial channels.

[0041] The mesh number of the silica aerogel selected in the present invention is 400 mesh; the montmorillonite is calcium-based montmorillonite with a mesh number of 400 mesh; the titanium dioxide is rutile titanium dioxide with CAS number: 13463-67-7 and product model DuPont R103; and the brand of the epoxy resin is epoxy resin E-51 or epoxy resin E-44.

[0042] Example 1

[0043] A method for preparing an aerogel composite thermal insulation coating comprises the following steps:

[0044] 100 parts of the composite emulsion and 8 parts of epoxy resin E-51 were mixed evenly to obtain a mixed solution, and then 15 parts of silica aerogel, 10 parts of modified montmorillonite, 8 parts of titanium dioxide, 3 parts of dispersant sodium polyphosphate, 2 parts of dodecyl alcohol and 2 parts of sodium methyl silicate were added to the mixed solution and mixed evenly to obtain an aerogel composite thermal insulation coating;

[0045] The preparation method of the composite emulsion is as follows: 2g of sodium dodecyl sulfate, 2g of nonylphenol polyoxyethylene ether NP-10 and 3g of tert-dodecyl mercaptan are added to 100 parts of deionized water, stirred evenly, nitrogen is introduced to exhaust the air, and then 10g of 4-vinylbenzene boronic acid, 20g of styrene and 15g of dodecyl acrylate are added thereto, stirred and heated to 60°C, and then 1g of initiator ammonium persulfate is added, reacted at 60°C for 3h, and after the reaction is completed, cooled to room temperature to obtain a composite emulsion;

[0046] The preparation method of the modified montmorillonite is as follows:

[0047] S1. Add 15 g of montmorillonite to 150 mL of 1 mol / L nitric acid solution, heat and stir at 80 °C for 2 h, then filter, wash, dry, and calcine at 500 °C for 4 h to obtain pretreated montmorillonite;

[0048] S2. Add 2 g of zirconium nitrate to 100 mL of deionized water, stir to dissolve, then add 10 g of pretreated montmorillonite thereto, stir evenly, adjust the pH of the solution to 9, dry, and calcine at 500 °C for 4 h to obtain a montmorillonite composite material;

[0049] S3. Disperse 10 g of the montmorillonite composite material in 100 mL of 80 wt% ethanol aqueous solution, then add 1 g of trifluorooctyltrimethoxysilane thereto, stir at room temperature for 2 h, then filter, wash, and dry to obtain modified montmorillonite.

[0050] Example 2

[0051] A preparation method of an aerogel composite thermal insulation coating, comprising the following steps:

[0052] Mix 80 parts of composite emulsion and 5 parts of epoxy resin E-44 evenly to obtain a mixed solution, then add 10 parts of silica aerogel, 8 parts of modified montmorillonite, 5 parts of titanium dioxide, 1 part of dispersant sodium polyphosphate, 1 part of dodecyl alcohol ester, and 1 part of sodium methyl silicate to the mixed solution, and mix evenly to obtain the aerogel composite thermal insulation coating;

[0053] Among them, the preparation method of the composite emulsion is as follows: Add 3 g of sodium dodecyl sulfate, 3 g of nonylphenol polyoxyethylene ether NP-10, and 4 g of tert-dodecyl mercaptan to 150 parts of deionized water, stir evenly, pass nitrogen to remove air, then add 15 g of 4-vinylbenzeneboronic acid, 25 g of styrene, and 20 g of dodecyl acrylate thereto, stir and heat up to 60 °C, then add 2 g of initiator ammonium persulfate, react at 60 °C for 3 h, and after the reaction is completed, cool to room temperature to obtain the composite emulsion;

[0054] The preparation method of the modified montmorillonite is as follows:

[0055] S1. Add 15 g of montmorillonite to 150 mL of 1 mol / L nitric acid solution, heat and stir at 80 °C for 2 h, then filter, wash, dry, and calcine at 500 °C for 4 h to obtain pretreated montmorillonite;

[0056] S2. Add 4 g of zirconium nitrate to 100 mL of deionized water, stir to dissolve, then add 15 g of pretreated montmorillonite thereto, stir evenly, adjust the pH of the solution to 9, dry, and calcine at 500 °C for 4 h to obtain a montmorillonite composite material;

[0057] S3. Disperse 15 g of montmorillonite composite in 100 mL of an 80 wt% ethanol aqueous solution, then add 3 g of tridecafluorooctyltrimethoxysilane thereto, stir at room temperature for 2 h, and then filter, wash, and dry to obtain modified montmorillonite.

[0058] Example 3

[0059] A preparation method of an aerogel composite thermal insulation coating includes the following steps:

[0060] Mix 120 parts of composite emulsion and 10 parts of epoxy resin E-44 evenly to obtain a mixed solution, then add 20 parts of silica aerogel, 15 parts of modified montmorillonite, 10 parts of titanium dioxide, 3 parts of dispersant sodium polyphosphate, 3 parts of dodecyl alcohol ester, and 3 parts of sodium methyl silicate to the mixed solution and mix evenly to obtain the aerogel composite thermal insulation coating;

[0061] Among them, the preparation method of the composite emulsion is as follows: Add 1 g of sodium dodecyl sulfate, 1 g of nonylphenol polyoxyethylene ether NP-10, and 2 g of tert-dodecyl mercaptan to 100 parts of deionized water, stir evenly, pass nitrogen to expel air, then add 10 g of 4-vinylbenzeneboronic acid, 20 g of styrene, and 20 g of octadecyl acrylate thereto, stir and heat up to 60 °C, then add 2 g of initiator ammonium persulfate, react at 60 °C for 3 h, and after the reaction is completed, cool to room temperature to obtain the composite emulsion;

[0062] The preparation method of the modified montmorillonite is as follows:

[0063] S1. Add 15 g of montmorillonite to 150 mL of a 1 mol / L nitric acid solution, heat and stir at 80 °C for 2 h, then filter, wash, and dry, and calcine at 500 °C for 4 h to obtain pretreated montmorillonite;

[0064] S2. Add 3 g of zirconium nitrate to 100 mL of deionized water, stir to dissolve, then add 12 g of pretreated montmorillonite thereto, stir evenly, adjust the pH of the solution to 9, dry, and calcine at 500 °C for 4 h to obtain montmorillonite composite;

[0065] S3. Disperse 12 g of montmorillonite composite in 100 mL of an 80 wt% ethanol aqueous solution, then add 2 g of tridecafluorooctyltrimethoxysilane thereto, stir at room temperature for 2 h, and then filter, wash, and dry to obtain modified montmorillonite.

[0066] Example 4

[0067] A preparation method of an aerogel composite thermal insulation coating includes the following steps:

[0068] Mix 90 parts of the composite emulsion and 8 parts of epoxy resin E-51 evenly to obtain a mixed solution. Then, add 15 parts of silica aerogel, 12 parts of modified montmorillonite, 6 parts of titanium dioxide, 2 parts of dispersant sodium polyphosphate, 2 parts of dodecyl alcohol ester, and 2 parts of sodium methyl silicate to the mixed solution and mix evenly to obtain the aerogel composite thermal insulation coating;

[0069] Among them, the preparation method of the composite emulsion is as follows: Add 2 g of sodium dodecyl sulfate, 3 g of nonylphenol polyoxyethylene ether NP-10, and 4 g of tert-dodecyl mercaptan to 120 parts of deionized water, stir evenly, introduce nitrogen to discharge air, and then add 12 g of 4-vinylbenzeneboronic acid, 24 g of styrene, and 16 g of dodecyl acrylate to it. Stir and heat up to 60 °C, then add 1.5 g of initiator ammonium persulfate and react at 60 °C for 3 h. After the reaction is completed, cool to room temperature to obtain the composite emulsion;

[0070] The preparation method of the modified montmorillonite is as follows:

[0071] S1. Add 15 g of montmorillonite to 150 mL of 1 mol / L nitric acid solution, heat and stir at 80 °C for 2 h, then filter, wash, dry, and calcine at 500 °C for 4 h to obtain pretreated montmorillonite;

[0072] S2. Add 3 g of zirconium nitrate to 100 mL of deionized water, stir to dissolve it, then add 12 g of pretreated montmorillonite to it, stir evenly, adjust the pH of the solution to 9, dry, and calcine at 500 °C for 4 h to obtain the montmorillonite composite material;

[0073] S3. Disperse 15 g of the montmorillonite composite material in 100 mL of 80 wt% ethanol aqueous solution, then add 3 g of trifluorooctyltrimethoxysilane to it, stir at room temperature for 2 h, then filter, wash, and dry to obtain the modified montmorillonite.

[0074] Comparative Example 1

[0075] A preparation method of an aerogel composite thermal insulation coating includes the following steps:

[0076] Mix 100 parts of the composite emulsion and 8 parts of epoxy resin E-51 evenly to obtain a mixed solution. Then, add 15 parts of silica aerogel, 10 parts of montmorillonite, 8 parts of titanium dioxide, 3 parts of dispersant sodium polyphosphate, 2 parts of dodecyl alcohol ester, and 2 parts of sodium methyl silicate to the mixed solution and mix evenly to obtain the aerogel composite thermal insulation coating;

[0077] Among them, the preparation method of the composite emulsion is as follows: Add 2 g of sodium dodecyl sulfate, 2 g of nonylphenol polyoxyethylene ether NP-10, and 3 g of tert-dodecyl mercaptan to 100 parts of deionized water, stir evenly, introduce nitrogen to discharge air, and then add 10 g of 4-vinylbenzeneboronic acid, 20 g of styrene, and 15 g of dodecyl acrylate thereto, stir and heat up to 60 °C, then add 1 g of initiator ammonium persulfate, react at 60 °C for 3 h, and after the reaction is completed, cool to room temperature to obtain the composite emulsion.

[0078] Compared with Example 1, in Comparative Example 1, montmorillonite was not modified.

[0079] Comparative Example 2

[0080] A preparation method of an aerogel composite thermal insulation coating includes the following steps:

[0081] Mix 100 parts of the composite emulsion and 8 parts of epoxy resin E-51 evenly to obtain a mixed solution, and then add 15 parts of silica aerogel, 10 parts of modified montmorillonite, 8 parts of titanium dioxide, 3 parts of dispersant sodium polyphosphate, 2 parts of dodecyl alcohol ester, and 2 parts of sodium methyl silicate to the mixed solution, and mix evenly to obtain the aerogel composite thermal insulation coating;

[0082] Among them, the preparation method of the composite emulsion is as follows: Add 2 g of sodium dodecyl sulfate, 2 g of nonylphenol polyoxyethylene ether NP-10, and 3 g of tert-dodecyl mercaptan to 100 parts of deionized water, stir evenly, introduce nitrogen to discharge air, and then add 10 g of 4-vinylbenzeneboronic acid, 20 g of styrene, and 15 g of dodecyl acrylate thereto, stir and heat up to 60 °C, then add 1 g of initiator ammonium persulfate, react at 60 °C for 3 h, and after the reaction is completed, cool to room temperature to obtain the composite emulsion;

[0083] The preparation method of the modified montmorillonite is as follows:

[0084] S1. Add 15 g of montmorillonite to 150 mL of 1 mol / L nitric acid solution, heat and stir at 80 °C for 2 h, then filter, wash, dry, and calcine at 500 °C for 4 h to obtain pretreated montmorillonite;

[0085] S2. Disperse 10 g of pretreated montmorillonite in 100 mL of 80 wt% ethanol aqueous solution, then add 1 g of trifluorooctyltrimethoxysilane thereto, stir at room temperature for 2 h, then filter, wash, dry to obtain modified montmorillonite.

[0086] Compared with Example 1, in Comparative Example 2, montmorillonite was not loaded with zirconia.

[0087] Comparative Example 3

[0088] A preparation method of an aerogel composite heat-insulating coating, comprising the following steps:

[0089] Mix 100 parts of composite emulsion and 8 parts of epoxy resin E-51 evenly to obtain a mixed solution, and then add 15 parts of silica aerogel, 10 parts of modified montmorillonite, 8 parts of titanium dioxide, 3 parts of dispersant sodium polyphosphate, 2 parts of dodecyl alcohol ester and 2 parts of sodium methyl silicate to the mixed solution, and mix evenly to obtain the aerogel composite heat-insulating coating;

[0090] Among them, the preparation method of the composite emulsion is as follows: Add 2 g of sodium dodecyl sulfate, 2 g of nonylphenol polyoxyethylene ether NP-10 and 3 g of tert-dodecyl mercaptan to 100 parts of deionized water, stir evenly, pass nitrogen to discharge air, and then add 20 g of styrene and 15 g of dodecyl acrylate to it, stir and heat up to 60 °C, then add 1 g of initiator ammonium persulfate, react at 60 °C for 3 h, and after the reaction is completed, cool to room temperature to obtain the composite emulsion;

[0091] The preparation method of the modified montmorillonite is as follows:

[0092] S1. Add 15 g of montmorillonite to 150 mL of 1 mol / L nitric acid solution, heat and stir at 80 °C for 2 h, then filter, wash and dry, and calcine at 500 °C for 4 h to obtain pretreated montmorillonite;

[0093] S2. Add 2 g of zirconium nitrate to 100 mL of deionized water, stir and dissolve it, then add 10 g of pretreated montmorillonite to it, stir evenly, adjust the pH of the solution to 9, dry, and calcine at 500 °C for 4 h to obtain a montmorillonite composite material;

[0094] S3. Disperse 10 g of montmorillonite composite material in 100 mL of 80 wt% ethanol aqueous solution, then add 1 g of trifluorooctyltrimethoxysilane to it, stir at room temperature for 2 h, then filter, wash and dry to obtain modified montmorillonite.

[0095] Compared with Example 1, 4-vinylbenzeneboronic acid was not added to the composite emulsion in Comparative Example 3.

[0096] Comparative Example 4

[0097] A preparation method of an aerogel composite heat-insulating coating, comprising the following steps:

[0098] Mix 100 parts of the composite emulsion and 8 parts of epoxy resin E-51 evenly to obtain a mixed solution. Then, add 15 parts of silica aerogel, 10 parts of modified montmorillonite, 8 parts of titanium dioxide, 3 parts of dispersant sodium polyphosphate, 2 parts of dodecyl alcohol ester, and 2 parts of sodium methyl silicate to the mixed solution and mix evenly to obtain the aerogel composite thermal insulation coating;

[0099] Among them, the preparation method of the composite emulsion is as follows: Add 2 g of sodium dodecyl sulfate, 2 g of nonylphenol polyoxyethylene ether NP-10, and 3 g of tert-dodecyl mercaptan to 100 parts of deionized water, stir evenly, pass nitrogen to expel air, and then add 10 g of 4-vinylbenzeneboronic acid and 15 g of dodecyl acrylate to it, stir and heat up to 60 °C, then add 1 g of initiator ammonium persulfate, react at 60 °C for 3 h, and after the reaction is completed, cool to room temperature to obtain the composite emulsion;

[0100] The preparation method of the modified montmorillonite is as follows:

[0101] S1. Add 15 g of montmorillonite to 150 mL of 1 mol / L nitric acid solution, heat and stir at 80 °C for 2 h, then filter, wash, dry, and calcine at 500 °C for 4 h to obtain pretreated montmorillonite;

[0102] S2. Add 2 g of zirconium nitrate to 100 mL of deionized water, stir and dissolve it, then add 10 g of pretreated montmorillonite to it, stir evenly, adjust the pH of the solution to 9, dry, and calcine at 500 °C for 4 h to obtain the montmorillonite composite material;

[0103] S3. Disperse 10 g of the montmorillonite composite material in 100 mL of 80 wt% ethanol aqueous solution, then add 1 g of trifluorooctyltrimethoxysilane to it, stir at room temperature for 2 h, then filter, wash, and dry to obtain the modified montmorillonite.

[0104] Compared with Example 1, styrene was not added to the composite emulsion in Comparative Example 4.

[0105] Perform performance tests on the thermal insulation coatings prepared in Examples 1-2 and Comparative Examples 1-4, specifically as follows:

[0106] According to the general technical requirements for architectural exterior wall coatings JG / T 512-2017, the thermal insulation coatings prepared in Examples 1-2 and Comparative Examples 1-4 were coated on the exterior wall panels by the roller coating method, and the coating thickness was 0.5 mm. After the thermal insulation coating was dried, its thermal conductivity, water resistance and flame retardancy were measured. Among them, the thermal conductivity was measured in accordance with GB / T 10295-2008 "Determination of steady-state thermal resistance and related characteristics of thermal insulation materials - Heat flow meter method", the water resistance was tested in accordance with the standard of GB / T 1733-1993, and the flame retardancy was tested in accordance with the standard of GB 12441-2018. The test results are shown in Table 1.

[0107] Table 1 Test results of coating properties of different groups

[0108] Thermal conductivity (W / (m·k)) Water resistance (h) Flame resistance time (min) Example 1 0.063 168 ＞30 Example 2 0.071 168 ＞30 Comparative Example 1 0.156 96 15 Comparative Example 2 0.137 168 18 Comparative Example 3 0.075 168 19 Comparative Example 4 0.104 120 27

[0109] As can be seen from the table, the coating materials prepared in the examples of the present invention have the characteristics of low thermal conductivity, good water resistance and good flame resistance.

[0110] Finally, it should be noted that the above embodiments do not limit the present invention in any form. For those skilled in the art, based on the present invention, some modifications and improvements can be made. Therefore, any modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection of the present invention.

Claims

1. An aerogel composite thermal insulation coating, characterized in that, Raw materials including the following components by weight parts: 80 - 120 parts of composite emulsion, 10 - 20 parts of aerogel, 8 - 15 parts of modified montmorillonite, 5 - 10 parts of titanium dioxide, 5 - 10 parts of epoxy resin, 1 - 5 parts of dispersant, 1 - 3 parts of dodecyl alcohol ester, 1 - 3 parts of sodium methyl silicate; Among them, the preparation method of the composite emulsion is as follows: Add sodium dodecyl sulfate, nonylphenol polyoxyethylene ether and tert-dodecyl mercaptan into deionized water, stir evenly, pass in nitrogen to discharge air, then add 4-vinylphenylboronic acid, styrene and acrylate to it, stir and heat up to 55 - 65 °C, then add initiator and carry out the reaction. After the reaction is completed, cool to room temperature to obtain the composite emulsion; The mass ratio of sodium dodecyl sulfate, nonylphenol polyoxyethylene ether, tert-dodecyl mercaptan, deionized water, 4-vinylphenylboronic acid, styrene, acrylate and initiator is 1 - 3:1 - 3:2 - 4:100 - 150:10 - 15:20 - 25:15 - 20:1 - 2; The preparation method of the modified montmorillonite is as follows: S1. Add montmorillonite into an acid solution, heat and stir, then filter, wash, dry and calcine to obtain pretreated montmorillonite; S2. Add zirconium nitrate into deionized water, stir to dissolve, then add pretreated montmorillonite to it, stir evenly, adjust the pH of the solution to 8 - 10, dry and calcine to obtain a montmorillonite composite material; S3. Disperse the montmorillonite composite material in an ethanol aqueous solution, then add 1H,1H,2H,2H-perfluorooctyltrimethoxysilane to it, stir, then filter, wash and dry to obtain modified montmorillonite.

2. The aerogel composite thermal insulation coating according to claim 1, wherein The initiator is selected from persulfate.

3. The aerogel composite thermal insulation coating according to claim 1, wherein, The acrylate has ≥10 carbon atoms.

4. The aerogel composite thermal insulation coating according to claim 1, wherein In step S2, the mass ratio of zirconium nitrate to pretreated montmorillonite is 2 - 4:10 - 15.

5. The aerogel composite thermal insulation coating according to claim 1, characterized in that, In step S3, the mass ratio of the montmorillonite composite material to 1H,1H,2H,2H-perfluorooctyltrimethoxysilane is 10 - 15:1 - 3.

6. The aerogel composite thermal insulation coating according to claim 1, wherein, The aerogel is selected from silica aerogel, and the dispersant is selected from polyphosphate.

7. The preparation method of the aerogel composite thermal insulation coating according to any one of claims 1-6, characterized in that, Including the following steps: Mix the composite emulsion and epoxy resin evenly to obtain a mixed solution, then add aerogel, modified montmorillonite, titanium dioxide, dispersant, dodecyl alcohol ester and sodium methyl silicate to the mixed solution and mix evenly to obtain an aerogel composite thermal insulation coating.