Transparent heat-insulating coating as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of coatings, and particularly relates to a transparent heat-insulating coating as well as a preparation method and application thereof. The transparent heat-insulating coating is prepared from modified nano aerogel, organic silicon modified acrylic emulsion, an auxiliary agent and water, the modified nano aerogel is obtained by modifying silicon dioxide nano aerogel by using fluorine-containing siloxane; the auxiliaries comprise a defoaming agent, a light stabilizer and a dispersing agent; the defoaming agent comprises a polysiloxane defoaming agent; the dispersing agent comprises an anionic polyacrylic acid sodium salt dispersing agent. Fluorine-containing siloxane is adopted to conduct hydrophobic modification on the silicon dioxide nano aerogel, the light transmittance of the coating can be guaranteed, and under the combined action of the fluorine-containing siloxane, the organic silicon modified acrylic emulsion, the light stabilizer, the specific type of dispersing agent and the defoaming agent, the coating is endowed with a good heat insulation effect under the condition that the light transmittance is not affected, and the coating has the good heat insulation effect. The light transmittance, the heat insulation property, the weather resistance, the pollution resistance, the acid rain resistance and the stability of the coating can be effectively improved.

Description

Technical Field

[0001] The invention belongs to the technical field of coatings, and in particular relates to a transparent heat-insulating coating and a preparation method and application thereof. Background Art

[0002] Today, as energy shortages and environmental pollution problems become increasingly prominent, energy conservation and consumption reduction as well as improving the effective utilization of energy are the current trends in social development. As people's living standards continue to improve, the requirements for a comfortable living environment are also increasing. For example, using air conditioning for cooling not only aggravates the greenhouse effect, but also requires a large amount of coal, natural gas and other energy sources to supply electricity.

[0003] Energy-saving buildings are a new type of energy-saving and environmentally friendly buildings. Their main feature is the thermal insulation effect. When achieving the thermal insulation function, the selection of thermal insulation materials, the layout of the thermal insulation system and the design of the thermal insulation system all play a key role. At present, the thermal insulation system of architectural coatings is mainly composed of primers, thermal insulation mid-coats, thermal insulation topcoats and transparent coatings. Most of the transparent coatings available on the market use light transmittance as the main design principle to ensure the color and decorativeness of the lower coating, but the functionality of transparent coatings is often difficult to balance. At present, the main material that gives coatings thermal insulation function is rutile titanium dioxide, but the use of titanium dioxide will greatly reduce the transmittance of the coating. Some also use silicone-modified acrylic resins, but the grafting rate of silicone is limited and its thermal insulation performance cannot be guaranteed.

[0004] Therefore, it is of great significance to provide a coating with good light transmittance and heat insulation effect. Summary of the invention

[0005] The present invention aims to solve one or more technical problems existing in the above-mentioned prior art and at least provide a beneficial choice. Specifically, the present invention provides a coating having good light transmittance and heat insulation effect.

[0006] The inventive concept of the present invention is as follows: the coating of the present invention comprises modified nano-aerogel, organosilicon-modified acrylic emulsion, auxiliary agent and water; the modified nano-aerogel is obtained by modifying silica nano-aerogel with fluorinated siloxane; the auxiliary agent comprises a defoamer, a light stabilizer and a dispersant; the defoamer comprises an organopolysiloxane defoamer; the dispersant comprises an anionic polyacrylic acid sodium salt dispersant. The present invention adopts fluorinated siloxane with low surface free energy to hydrophobically modify silica nano-aerogel to obtain hydrophobic modified nano-aerogel with a special three-dimensional network structure, which has extremely low thermal conductivity and high contact angle, is transparent after dispersion, can ensure the light transmittance of the coating, and works together with organosilicon-modified acrylic emulsion, light stabilizer, specific types of dispersant and defoamer to give the coating a good heat insulation effect without affecting the light transmittance, and also has good weather resistance, stain resistance, acid rain resistance, low temperature stability and storage stability.

[0007] Therefore, a first aspect of the present invention provides a transparent heat-insulating coating.

[0008] Specifically, the transparent heat-insulating coating comprises modified nano-aerogel, silicone-modified acrylic emulsion, additives, and water;

[0009] The modified nano aerogel is obtained by modifying the silicon dioxide nano aerogel with fluorine-containing siloxane;

[0010] The auxiliary agents include defoamers, light stabilizers and dispersants;

[0011] The defoaming agent includes a polysiloxane defoaming agent;

[0012] The dispersant includes an anionic polyacrylic acid sodium salt dispersant.

[0013] Preferably, the coating comprises, by weight, 9-33 parts of modified nano aerogel, 18-55 parts of silicone-modified acrylic emulsion, 0.1-2.2 parts of dispersant, 0.1-2.2 parts of light stabilizer, 0.1-1.1 parts of defoamer, and 27-65 parts of water.

[0014] Further preferably, the coating comprises, by weight, 10-30 parts of modified nano aerogel, 20-50 parts of silicone-modified acrylic emulsion, 0.1-2 parts of dispersant, 0.1-2 parts of light stabilizer, 0.1-1 parts of defoamer, and 30-60 parts of water.

[0015] Preferably, the auxiliary agent further includes at least one of a pH regulator, a film-forming auxiliary agent, a leveling agent, an antifreeze agent, a bactericide, a mildewcide, and a thickener.

[0016] Preferably, the additives also include a pH regulator, a film-forming aid, a leveling agent, an antifreeze agent, a bactericide, a mildew preventer and a thickener, and the coating includes, by weight, 9-33 parts of modified nano aerogel, 0.1-2.2 parts of dispersant, 0.1-2.2 parts of pH regulator, 18-55 parts of silicone-modified acrylic emulsion, 0.1-3.3 parts of film-forming aid, 0.1-2.2 parts of light stabilizer, 0.1-1.1 parts of defoamer, 0.1-1.1 parts of leveling agent, 0.1-1.1 parts of antifreeze agent, 0.1-1.1 parts of bactericide, 0.1-1.1 parts of mildew preventer, 0.1-1.1 parts of thickener and 27-65 parts of water.

[0017] Further preferably, the additives also include a pH regulator, a film-forming aid, a leveling agent, an antifreeze agent, a bactericide, a mildew preventer and a thickener, and the coating includes, by weight, 10-30 parts of modified nano aerogel, 0.1-2 parts of a dispersant, 0.1-2 parts of a pH regulator, 20-50 parts of a silicone-modified acrylic emulsion, 0.1-3 parts of a film-forming aid, 0.1-2 parts of a light stabilizer, 0.1-1 parts of a defoamer, 0.1-1 parts of a leveling agent, 0.1-1 parts of an antifreeze agent, 0.1-1 parts of a bactericide, 0.1-1 parts of a mildew preventer, 0.1-1 parts of a thickener, and 30-60 parts of water.

[0018] Specifically, the modified nano aerogel is a hydrophobic powder having a special three-dimensional network structure, and the maximum spacing of its internal skeleton is 50nm.

[0019] Preferably, the particle size of the modified nano aerogel is 4.5-110 nm; further preferably, the particle size of the modified nano aerogel is 5-100 nm.

[0020] Preferably, the hydrophobic angle of the modified nano-aerogel is greater than 140°, and further preferably, the hydrophobic angle of the modified nano-aerogel is greater than 140° and less than or equal to 160°.

[0021] Preferably, the thermal conductivity of the modified nano-aerogel is 0.009-0.045 W / (m·K); further preferably, the thermal conductivity of the modified nano-aerogel is 0.01-0.04 W / (m·K).

[0022] Preferably, the silicone-modified acrylic emulsion is a core-shell silicone acrylic emulsion having excellent stain resistance and weather resistance, and excellent light transmittance; preferably at least one of Rosf ROSF-5019A, Badford RS-996KD, and Sunrise RC-1269F.

[0023] Specifically, the dispersant is an anionic polyacrylic acid sodium salt dispersant having an amphiphilic hydrophilic and lipophilic structure, the hydrophobic end is connected to and covers the modified nano aerogel, and the hydrophilic end is in the outer layer of the modified nano aerogel to make it hydrophilic, thereby improving the compatibility with the aqueous system.

[0024] Preferably, the dispersant includes at least one of San Nopco SN-5040, Dow Chemical OROTAN 9830A, and Baolijia BLJ5040.

[0025] Specifically, compared with mineral oil defoamers, the defoamer of the present invention is an organopolysiloxane defoamer, which, combined with other components, can better ensure the gloss and transparency of the coating and has better anti-foaming and defoaming effects. It is preferably at least one of Evonik TEGO Airex 901W, BYK-093, BYK-094, and BYK-1610.

[0026] Preferably, the light stabilizer includes a benzotriazole ultraviolet light absorber and a hindered amine light stabilizer.

[0027] Further preferably, the light stabilizer includes at least one of HS-3203 and HS-3310 produced by Beijing Tiangang.

[0028] Specifically, weather resistance can be improved through the efficient coordination of the two components.

[0029] Preferably, the pH adjuster includes at least one of diethanolamine, butyldiethylenediamine, 2-amino-2-methyl-1-propanol, and 2-amino-2-ethyl-1,3-propanediol.

[0030] Further preferably, the pH adjuster comprises Dow AMP-95.

[0031] Preferably, the film-forming aid comprises an alcohol ester film-forming aid.

[0032] Further preferably, the film-forming aid includes at least one of Runtai Ester Alcohol 12, Runtai Hexadecene Diester, and Dow COASOL.

[0033] Preferably, the leveling agent includes a polyether-modified silicone surfactant.

[0034] Specifically, the leveling agent can effectively reduce surface tension, improve the leveling property of the coating and the wettability of the substrate, and is preferably at least one of BYK-333, BYK-346 and BYK-348 produced by BYK Chemical.

[0035] Preferably, the thickener comprises an aqueous non-ionic modified polyurethane thickener.

[0036] Further preferably, the thickener includes RM-8W, RM-2020, At least one of PU 1341.

[0037] Preferably, the antifreeze comprises an alcohol antifreeze.

[0038] Further preferably, the antifreeze agent includes at least one of ethylene glycol, propylene glycol and polyethylene glycol.

[0039] Preferably, the fungicide includes at least one of 5-chloro-2-methylisothiazoline-3-one, 2-methyl-4-isothiazoline-3-one, and 1,2-benzisothiazolin-3-one; preferably at least one of Dow Chemical's ROCIMA623, ROCIMA631, and ROCIMA562.

[0040] Preferably, the mildew preventer includes at least one of iodopropynyl n-butylcarbamate, methyl benzimidazole carbamate, and dichlorophenol dimethyl urea; preferably at least one of PREVENTOL BM5, PREVENTOL D7, and PREVENTOL A21D produced by LANXESS Chemical.

[0041] The second aspect of the present invention provides a method for preparing the transparent heat-insulating coating according to the first aspect of the present invention.

[0042] Specifically, the method for preparing the transparent heat-insulating coating comprises the following steps:

[0043] The various raw material components are mixed to prepare the transparent heat-insulating coating.

[0044] Preferably, the method for preparing the transparent heat-insulating coating comprises the following steps:

[0045] The water, modified nano aerogel, dispersant and pH regulator are first mixed to obtain a mixture, and then the mixture is mixed with the organosilicon-modified acrylic emulsion, film-forming aid, light stabilizer, defoamer, leveling agent, antifreeze agent, bactericide, mildewproofing agent and thickener to obtain the coating.

[0046] Preferably, the method for preparing the modified nano aerogel comprises the following steps:

[0047] (1) mixing silica nanoaerogel and a solvent to obtain a slurry;

[0048] (2) The slurry obtained in step (1) and fluorinated silicone are mixed and reacted to obtain the modified nano aerogel.

[0049] Preferably, step (1) specifically comprises mixing the silica nanoaerogel and the solvent, stirring and sand-milling to obtain a slurry.

[0050] Preferably, the silica nano-aerogel is silica nano-aerogel powder.

[0051] Preferably, the solvent comprises anhydrous ethanol.

[0052] Preferably, the mass ratio of the silica nanoaerogel to the solvent is 1:(20-30); further preferably, the mass ratio of the silica nanoaerogel to the solvent is 1:(22-27); further preferably, the mass ratio of the silica nanoaerogel to the solvent is 1:25.

[0053] Preferably, step (2) specifically comprises mixing the slurry obtained in step (1) and fluorinated silicone, adjusting the pH to acidic, heating, reacting, cooling to room temperature after the reaction, centrifuging, washing, drying, and grinding to obtain the modified nano aerogel.

[0054] Preferably, the modified nano aerogel is modified nano aerogel powder.

[0055] Preferably, in step (2), the amount of the fluorinated silicone is 2.5-3.5% of the mass of the slurry; further preferably, the amount of the fluorinated silicone is 2.7-3.3% of the mass of the slurry; further preferably, the amount of the fluorinated silicone is 3% of the mass of the slurry.

[0056] Preferably, in step (2), the reaction temperature is 60-80°C, and the reaction time is 4-6h; further preferably, the reaction temperature is 65-75°C, and the reaction time is 4.5-5.5h; further preferably, the reaction temperature is 70°C, and the reaction time is 5h.

[0057] Preferably, the method for preparing the fluorinated silicone comprises the following steps:

[0058] The fluorine-containing esters and the silane coupling agent are mixed and reacted to obtain the fluorine-containing siloxane.

[0059] Preferably, the fluorine-containing esters include at least one of tridecafluorooctyl methacrylate and perfluorohexylethyl methacrylate.

[0060] Preferably, the silane coupling agent includes at least one of γ-methacryloxypropyltrimethoxysilane and γ-aminopropyltriethoxysilane.

[0061] Preferably, the mass ratio of the fluorinated ester to the silane coupling agent is (1.5-2.5):1; further preferably, the mass ratio of the fluorinated ester to the silane coupling agent is (1.8-2.2):1; further preferably, the mass ratio of the fluorinated ester to the silane coupling agent is 2:1.

[0062] Preferably, in the preparation process of the fluorinated silicone, the reaction temperature is 45-65°C, and the reaction time is 16-25h; further preferably, the reaction temperature is 50-60°C, and the reaction time is 18-22h; further preferably, the reaction temperature is 55°C, and the reaction time is 20h.

[0063] Preferably, the reaction is carried out in an inert gas atmosphere.

[0064] The third aspect of the present invention provides a use of the transparent heat-insulating coating described in the first aspect of the present invention in the field of construction.

[0065] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0066] (1) The present invention uses fluorinated siloxane with low surface free energy to hydrophobically modify silica nanoaerogel to obtain hydrophobic modified nanoaerogel with a special three-dimensional network structure. The modified nanoaerogel has extremely low thermal conductivity and high contact angle, and is transparent after dispersion, which can ensure the light transmittance of the coating. The modified nanoaerogel works together with organosilicon-modified acrylic emulsion, light stabilizer, specific types of dispersant and defoamer to give the coating a good thermal insulation effect without affecting the light transmittance, and makes the coating have good weather resistance, stain resistance, acid rain resistance and stability.

[0067] (2) The organosilicon-modified acrylic emulsion of the present invention is a core-shell type silicone acrylic emulsion, which, combined with a light stabilizer, can effectively absorb and block ultraviolet light, thereby improving the weather resistance of the coating.

[0068] (3) The additive system provided by the present invention can well integrate the hydrophobic modified nano aerogel into the aqueous system, ensuring the compatibility and stability of the system, and finally producing a coating with good light transmittance, acid rain resistance, weather resistance, stain resistance and heat insulation. DETAILED DESCRIPTION

[0069] In order to make the technical scheme of the present invention more clearly understood by those skilled in the art, the following embodiments are listed for illustration. It should be pointed out that the following embodiments do not limit the protection scope of the present invention.

[0070] Unless otherwise specified, the raw materials, reagents or devices used in the following examples can be obtained from conventional commercial sources or by existing known methods.

[0071] Example 1

[0072] A transparent heat-insulating coating, comprising, by weight:

[0073]

[0074] A method for preparing a transparent heat-insulating coating comprises the following steps:

[0075] Water, modified nano aerogel powder, dispersant and pH adjuster were added into the reactor, and dispersed at a high speed of 1400 rpm for 15 minutes to fully depolymerize the modified nano aerogel powder. The rotation speed was adjusted to a medium speed of 700 rpm, and silicone-modified acrylic emulsion, film-forming aid, light stabilizer, defoamer, leveling agent, antifreeze agent, bactericidal preservative and thickener were added in sequence. After each material was added, it was necessary to stir for 3 minutes to obtain a transparent heat-insulating coating.

[0076] The preparation method of modified nano aerogel powder comprises the following steps:

[0077] (1) adding nano-scale silica aerogel powder and anhydrous ethanol in a mass ratio of 1:25 into a reactor, stirring at room temperature for 30 minutes, and then sand-milling once with a sand mill to obtain a nano-aerogel slurry;

[0078] (2) placing tridecafluorooctyl methacrylate and γ-aminopropyltriethoxysilane in a reaction kettle at a mass ratio of 2:1, maintaining the temperature at 55°C, and introducing nitrogen for protection, and performing the synthesis reaction for 20 hours. After completion, the reaction was cooled to room temperature to obtain fluorinated siloxane;

[0079] (3) Slowly adding the fluorinated silicone obtained in step (2) to the reactor of step (1) at 3% of the mass of the nano aerogel slurry obtained in step (1), adjusting the pH to 3, heating to 70° C., stirring and reacting for 5 h, cooling to room temperature after the reaction, transferring to a centrifuge for centrifugation, washing with anhydrous ethanol for 3 times, and finally drying at 100° C. for 12 h, and grinding to obtain modified nano aerogel powder.

[0080] Example 2

[0081] A transparent heat-insulating coating, comprising, by weight:

[0082]

[0083] The preparation method of the transparent heat-insulating coating of Example 2 is the same as that of Example 1.

[0084] Example 3

[0085] A transparent heat-insulating coating, comprising, by weight:

[0086]

[0087]

[0088] The preparation method of the transparent heat-insulating coating of Example 3 is the same as that of Example 1.

[0089] Comparative Example 1

[0090] The difference between Comparative Example 1 and Example 1 is that Comparative Example 1 uses an equal amount of water to replace the modified nano aerogel powder and the dispersant, that is, does not contain the modified nano aerogel powder and the dispersant, and the amount of the pH regulator AMP-95 is 0.1 parts, and the rest is the same as Example 1.

[0091] Comparative Example 2

[0092] The difference between Comparative Example 2 and Example 1 is that Comparative Example 2 uses an equal amount of Zhongning Technology Aerogel AG-D to replace the modified nano aerogel powder, and the rest is the same as Example 1.

[0093] Comparative Example 3

[0094] The difference between Comparative Example 3 and Example 1 is that Comparative Example 3 uses an equal amount of Sunrise styrene acrylic emulsion RC-1269A to replace the silicone-modified acrylic emulsion, and the rest is the same as Example 1.

[0095] Comparative Example 4

[0096] The difference between Comparative Example 4 and Example 1 is that Comparative Example 4 uses an equal amount of BASF Tinuvin P light stabilizer to replace HS-3203, and the rest is the same as Example 1.

[0097] Comparative Example 5

[0098] The difference between Comparative Example 5 and Example 1 is that Comparative Example 5 uses an equal amount of PVA1799 (Inner Mongolia Shuangxin) dispersant to replace dispersant SN-5040, and the rest is the same as Example 1.

[0099] Comparative Example 6

[0100] The difference between Comparative Example 6 and Example 1 is that Comparative Example 6 uses an equal amount of RhodoLine DF 5800C (Solvirodia) defoamer to replace the defoamer TEGO Airex 901W, and the rest is the same as Example 1.

[0101] Performance Testing

[0102] The coatings prepared in Examples 1-3 and Comparative Examples 1-6 were subjected to performance tests. The specific test items, test methods and evaluation criteria are shown in Table 1.

[0103] Table 1: Test items, test methods and evaluation criteria

[0104] Test items Test Method Evaluation Criteria Status in container HG / T 5065-2016 After stirring, there is no hard lump and it is in a uniform state Construction HG / T 5065-2016 Barrier-free application Drying time (surface drying) / h HG / T 5065-2016 ≤1 Drying time (actual drying) / h HG / T 5065-2016 ≤24 Coating appearance HG / T 5065-2016 normal Water resistance (96h) HG / T 5065-2016 No abnormality Alkali resistance (48h) HG / T 5065-2016 No abnormality Coating temperature resistance HG / T 5065-2016 No abnormality Washability (2000 times) HG / T 5065-2016 The paint film is not damaged Compatibility with underlying coatings HG / T 5065-2016 pass Light transmittance / % HG / T 5065-2016 ≥90 Acid rain resistance (48h) HG / T 5065-2016 No abnormality Stain resistance / % HG / T 5065-2016 ≤15％ Artificial weathering resistance HG / T 5065-2016 1000h passed Low temperature stability HG / T 5065-2016 No deterioration Storage stability at 50℃ (30 days) / No stratification Thermal insulation temperature difference with reference blackboard / ℃ GB / T25261-2018 Measured

[0105] The performance test results of the coatings of Examples 1-3 and Comparative Examples 1-6 are shown in Table 2.

[0106] Table 2: Performance test results of coatings of Examples 1-3 and Comparative Examples 1-6

[0107]

[0108] It can be seen from Table 1 that the coating prepared by the present invention has good light transmittance and heat insulation at the same time, which can solve the problem that light transmittance and heat insulation cannot be taken into account at the same time, and has good acid rain resistance, weather resistance, stain resistance and stability.

[0109] It can be seen from Comparative Examples 1-2 and Example 1 that, compared with siloxane-modified aerogel powder, the nano-aerogel powder modified by fluorinated siloxane in the present invention can make the coating have better acid resistance, stain resistance, and heat insulation, while taking into account the light transmittance of the coating. In addition, while improving the performance, the color and decorativeness of the underlying coating can also be maintained. This is because the aerogel modified by fluorinated siloxane has a small radius of fluorine atoms and low surface free energy. After being grafted with silane to the aerogel, better acid resistance, a larger hydrophobic contact angle, stronger stain resistance and self-cleaning properties can be obtained.

[0110] It can be seen from Comparative Example 3 and Example 1 that, compared with ordinary styrene acrylic emulsion, the present invention uses core-shell silicone acrylic emulsion and other components to improve thermal insulation, weather resistance and stain resistance. This is because the core-shell structure of the core-shell silicone acrylic emulsion can reduce thermal conductivity, and the weather resistance can be further improved after modification with organic silicon.

[0111] It can be seen from Comparative Example 4 and Example 1 that the addition of a light stabilizer in combination with other components in the present invention can improve heat insulation, weather resistance and stain resistance, and can also improve light transmittance to a certain extent.

[0112] It can be seen from Comparative Examples 5-6 and Example 1 that, compared with common dispersants and defoamers, the present invention uses anionic polyacrylic acid sodium salt dispersants and organopolysiloxane defoamers with amphoteric hydrophilic and lipophilic structures, which can improve light transmittance, heat insulation, stain resistance and system stability. This is because the hydrophobic end of the dispersant with an amphiphilic structure is connected to and coated with the modified nano aerogel, and the hydrophilic end is in the outer layer of the aerogel to make it hydrophilic. At the same time, the organopolysiloxane defoamer is used to make the modified aerogel powder better depolymerized into nanometers, give full play to the heat insulation performance of the aerogel, and keep the system stable, so that the storage stability of the coating system is improved, and it has better light transmittance.

[0113] It can be seen from Examples 1-3 and Comparative Example 1 that the addition of a specific type of modified nano aerogel in the present invention can significantly improve the thermal insulation performance of the coating, and the higher the amount of modified nano aerogel used, the better the thermal insulation performance of the coating.

[0114] In summary, the present invention uses fluorinated siloxane with low surface free energy to hydrophobically modify silica nanoaerogel, which can ensure the light transmittance of the coating, and works together with silicone-modified acrylic resin, light stabilizer, specific types of dispersants and defoaming agents to give the coating a good thermal insulation effect without affecting the light transmittance, and can also improve the light transmittance, thermal insulation, weather resistance, stain resistance, acid rain resistance and stability of the coating.

[0115] The above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A coating, characterized in that: Including modified nano aerogel, silicone modified acrylic emulsion, additives, and water; The modified nano aerogel is obtained by modifying the silicon dioxide nano aerogel with fluorine-containing siloxane; The auxiliary agents include defoamers, light stabilizers and dispersants; The defoaming agent includes a polysiloxane defoaming agent; The dispersant includes an anionic polyacrylic acid sodium salt dispersant.

2. The coating according to claim 1, characterized in that Calculated by weight, the coating comprises 9-33 parts of modified nano aerogel, 18-55 parts of organosilicon-modified acrylic emulsion, 0.1-2.2 parts of dispersant, 0.1-2.2 parts of light stabilizer, 0.1-1.1 parts of defoamer and 27-65 parts of water.

3. The coating according to claim 1, characterized in that The auxiliary agent also includes at least one of a pH regulator, a film-forming auxiliary agent, a leveling agent, an antifreeze agent, a bactericide, a mildew preventer, and a thickener.

4. The coating according to claim 3, characterized in that The additives also include a pH regulator, a film-forming aid, a leveling agent, an antifreeze agent, a bactericide, a mildew preventer and a thickener, and the coating includes, by weight, 9-33 parts of modified nano aerogel, 0.1-2.2 parts of a dispersant, 0.1-2.2 parts of a pH regulator, 18-55 parts of an organosilicon-modified acrylic emulsion, 0.1-3.3 parts of a film-forming aid, 0.1-2.2 parts of a light stabilizer, 0.1-1.1 parts of a defoamer, 0.1-1.1 parts of a leveling agent, 0.1-1.1 parts of an antifreeze agent, 0.1-1.1 parts of a bactericide, 0.1-1.1 parts of a mildew preventer, 0.1-1.1 parts of a thickener and 27-65 parts of water.

5. The coating according to claim 3, characterized in that The light stabilizer includes a benzotriazole ultraviolet light absorber and a hindered amine light stabilizer; and / or, the pH adjuster includes at least one of diethanolamine, butyl diethylenediamine, 2-amino-2-methyl-1-propanol, and 2-amino-2-ethyl-1,3-propanediol; and / or, the film-forming aid includes an alcohol ester film-forming aid; and / or, the leveling agent includes a polyether-modified silicone surfactant; and / or, the thickener includes an aqueous non-ionic modified polyurethane thickener.

6. The method for preparing the coating according to any one of claims 1 to 5, characterized in that: The following steps are involved: The coating is prepared by mixing various raw material components.

7. The preparation method according to claim 6, characterized in that: The preparation method of the modified nano aerogel comprises the following steps: (1) mixing silica nanoaerogel and a solvent to obtain a slurry; (2) The slurry obtained in step (1) and fluorinated silicone are mixed and reacted to obtain the modified nano aerogel.

8. The preparation method according to claim 7, characterized in that: In step (2), the amount of the fluorinated silicone is 2.5-3.5% of the mass of the slurry; and / or, the reaction temperature is 60-80°C, and the reaction time is 4-6h; and / or, the preparation method of the fluorinated silicone comprises the following steps: mixing a fluorinated lipid substance with a silane coupling agent, reacting, and obtaining the fluorinated silicone.

9. The preparation method according to claim 8, characterized in that: The fluorine-containing lipid substance includes at least one of tridecafluorooctyl methacrylate and perfluorohexylethyl methacrylate; and / or, the silane coupling agent includes at least one of γ-methacryloxypropyltrimethoxysilane and γ-aminopropyltriethoxysilane; and / or, the mass ratio of the fluorine-containing lipid substance to the silane coupling agent is (1.5-2.5):1; and / or, during the preparation of the fluorine-containing silicone, the reaction temperature is 45-65°C and the reaction time is 16-25h.

10. Use of the coating according to any one of claims 1 to 5 in the field of construction.

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