Fluorine-modified silica aerogel and its preparation method, application, heat-insulating coating and its preparation method, application

Abstract

The present invention provides a fluorine-modified silica aerogel, a preparation method thereof, an application thereof, a heat-insulating coating and a preparation method thereof, and an application thereof, relating to the technical field of heat-insulating coatings. The heat-insulating coating of the present invention comprises the following components: cellulose, titanium dioxide, filler, auxiliary agent, fluorine-modified silica aerogel, silicate, acrylic emulsion, and water. The present invention solves the technical problems of the collapse and too heavy particle feeling of the topcoat paint of the aerogel, and achieves the technical effects of smooth and beautiful topcoat paint and excellent heat insulation and heat preservation.

Description

Technical Field

[0001] The present invention relates to the technical field of heat-insulating coatings, and particularly to a fluorine-modified silica aerogel and its preparation method, application, heat-insulating coating and its preparation method, application. Background Art

[0002] With the development of technology and the progress of society, the problems of energy consumption and environmental damage have become increasingly prominent. Among energy consumption, building energy consumption has become a high-energy-consuming industry alongside industrial energy consumption and transportation energy consumption. Among them, building energy consumption accounts for about 40% of the total social energy consumption, and 70-80% of the loss is caused by heat loss of the envelope structure.

[0003] At present, most building heat-insulating measures adopt the method of painting reflective heat-insulating coatings on the roof and walls to reduce the impact of sunlight on the temperature of the building, lower the surface temperature of the building, and thus reduce the indoor temperature to make the indoor reach a relatively comfortable temperature. Its principle is to reflect and scatter as much as possible the electromagnetic waves that generate energy in sunlight to reduce the absorption of sunlight by the building wall, thereby reducing the temperature of the outer wall surface. However, this kind of coating is only suitable for playing a heat-insulating role in summer in areas with hot summers and cold winters and areas with hot summers and warm winters. In severely cold or cold regions, especially in winter, it cannot play a heat-preserving role. At the same time, the heat-preserving performance of the reflective heat-insulating coating is unstable and will change with the change of the coating lightness. Basically, it can only meet the requirements of heat-preserving performance in the white state.

[0004] In view of the heat-preserving defects of the reflective coating, in recent years, aerogel-type reflective / radiative coatings have also emerged one after another. Their performance has been greatly improved compared with traditional reflective coatings, and the heat-preserving effect is more obvious. However, as a porous material, the solid content of the topcoat of aerogel is low, and it is easy to appear surface collapse after film formation, resulting in uneven surface and affecting the appearance. At the same time, the topcoat prepared from aerogel powder also has the defect of too heavy particle feeling, so it is also very difficult to be actually applied.

[0005] In view of this, the present invention is particularly proposed. Summary of the Invention

[0006] One of the purposes of the present invention is to provide a fluorine-modified silica aerogel, which has the advantage of high strength. When used in combination with an inorganic film-forming substance, it can solve the problems of collapse and particle feeling generated by the topcoat of aerogel, make the topcoat smooth and beautiful, and has a significant heat-insulating and heat-preserving effect.

[0007] Another purpose of the present invention is to provide a preparation method of a fluorine-modified silica aerogel, which is simple and efficient in process.

[0008] A third object of the present invention is to provide an application of fluorine-modified silica aerogel in the preparation of heat-insulating coatings, which can make the appearance of the topcoat paint flat and shiny, with a smooth touch, solve the technical problems of collapse and heavy particle feeling of the topcoat paint of aerogel, and achieve the technical effects of smooth and beautiful topcoat paint and excellent heat insulation and heat preservation.

[0009] A fourth object of the present invention is to provide a heat-insulating coating, which has the advantages of smooth and beautiful topcoat paint and excellent heat insulation and heat preservation, and avoids the problems of collapse and heavy particle feeling of the topcoat paint.

[0010] A fifth object of the present invention is to provide a preparation method of a heat-insulating coating, which is simple and efficient in process.

[0011] A sixth object of the present invention is to provide an application of a heat-insulating coating, which has excellent heat insulation and heat preservation effects and remarkable energy-saving effects.

[0012] In order to achieve the above objects of the present invention, the following technical solutions are specifically adopted:

[0013] In the first aspect, a fluorine-modified silica aerogel is mainly prepared from the following components by mass:

[0014] 6-12 parts of tetraethyl orthosilicate, 2-4 parts of methacryloxypropyltrimethoxysilane, and 4-8 parts of vinylidene fluoride.

[0015] In the second aspect, a preparation method of a fluorine-modified silica aerogel includes the following steps:

[0016] (a) Tetraethyl orthosilicate is acid-dissolved to obtain a silicic acid solution, and then the pH is adjusted and aged to obtain a silica gel;

[0017] (b) The silica gel obtained in step (a) reacts with the methoxy group of methacryloxypropyltrimethoxysilane by alcoholysis reaction to obtain a silica gel modified with methacryloxypropyltrimethoxysilane on the surface;

[0018] (c) The silica gel modified with methacryloxypropyltrimethoxysilane on the surface obtained in step (b) reacts with vinylidene fluoride by a polymerization reaction to obtain the fluorine-modified silica aerogel.

[0019] Further, the pH value adjusted in step (a) is 5-6;

[0020] Preferably, the temperature of the alcoholysis reaction in step (b) is 40-60 °C;

[0021] Preferably, the temperature of the polymerization reaction in step (c) is 70-80 °C;

[0022] Preferably, step (c) includes the following steps:

[0023] The surface of the silica gel modified with 3-(trimethoxysilyl)propyl methacrylate obtained in step (b) is immersed in an alcohol solution of vinylidene fluoride, and then ammonium persulfate is added, followed by a polymerization reaction to obtain the fluorine-modified silica aerogel.

[0024] Thirdly, an application of the fluorine-modified silica aerogel in preparing a heat-insulating coating.

[0025] Fourthly, a heat-insulating coating, comprising the following components:

[0026] Cellulose, titanium dioxide, filler, additives, the above-mentioned fluorine-modified silica aerogel, silicate, acrylic emulsion, and water.

[0027] Furthermore, the cellulose includes at least one of hydroxymethyl cellulose and hydroxyethyl cellulose;

[0028] Preferably, the titanium dioxide includes at least one of rutile titanium dioxide and anatase titanium dioxide;

[0029] Preferably, the filler includes at least one of kaolin, talc powder, heavy calcium, and titanium dioxide;

[0030] Preferably, the additives include at least one of a dispersant, a wetting agent, a thickener, an antifoaming agent, a preservative, a pH regulator, a film-forming aid, and an antifreezing agent;

[0031] Preferably, the particle size of the above-mentioned fluorine-modified silica aerogel is 20 - 100 nm;

[0032] Preferably, the silicate includes at least one of potassium silicate, lithium silicate, and sodium silicate;

[0033] Preferably, the potassium silicate includes modified potassium silicate.

[0034] Furthermore, the heat-insulating coating comprises the following components in parts by mass:

[0035] Cellulose 0.1 - 0.3 parts, rutile titanium dioxide 15 - 25 parts, filler 5 - 15 parts, additives 1 - 7 parts, the above-mentioned fluorine-modified silica aerogel 5 - 20 parts, modified potassium silicate 10 - 15 parts, acrylic emulsion 1 - 5 parts, and water 10 - 15 parts.

[0036] Furthermore, the additives include the following components in parts by mass:

[0037] 0.5 - 1.5 parts of dispersant, 0.2 - 0.5 parts of wetting agent, 0.2 - 0.5 parts of thickener, 0.3 - 0.6 parts of defoamer, 0.1 - 0.3 parts of preservative, 0.1 - 0.3 parts of pH regulator, 0.5 - 2 parts of film-forming auxiliary, and 1 - 2 parts of antifreezing agent.

[0038] Fifth aspect, a preparation method of the heat-insulating coating according to any one of the above, characterized by comprising the following steps:

[0039] Mix each component to obtain the heat-insulating coating;

[0040] Preferably, the preparation method comprises the following steps:

[0041] Mix water and cellulose, then add titanium dioxide and filler and mix, then add auxiliary agents and mix, then add fluorine-modified silica aerogel and mix, and then add silicate and acrylic emulsion to obtain the heat-insulating coating.

[0042] Sixth aspect, an application of the heat-insulating coating according to any one of the above in building insulation.

[0043] Compared with the prior art, the present invention has at least the following beneficial effects:

[0044] The fluorine-modified silica aerogel provided by the present invention has the advantages of high strength under the synergistic cooperation of specific raw material components and their ratios, excellent performance. When applied to the aerogel topcoat and used in combination with inorganic film-forming substances, it can solve the problems of collapse and particle feeling generated by the aerogel topcoat, making the topcoat smooth and beautiful, and having a remarkable heat-insulating and heat-preserving effect.

[0045] The preparation method of the fluorine-modified silica aerogel provided by the present invention is simple and efficient.

[0046] The application of the fluorine-modified silica aerogel provided by the present invention. The fluorine-modified silica aerogel has the characteristics of high strength, strong toughness, and easy leveling, which can make the appearance of the topcoat of the heat-insulating coating flat and shiny. At the same time, it has good heat-insulating and heat-preserving performance, smooth hand feeling, and solves the technical problems of collapse and too heavy particle feeling of the aerogel topcoat, achieving the technical effects of smooth and beautiful topcoat, high solar reflectance and near-infrared reflectance, and good heat-insulating and heat-preserving performance.

[0047] The heat-insulating coating provided by the present invention, through the particle overlapping technology, uses the fluorine-modified silica aerogel in combination with inorganic film-forming substances and other components, and through synergistic cooperation, can avoid the collapse of the aerogel topcoat and reduce the particle feeling of the topcoat, thereby solving the problems of collapse and too heavy particle feeling of the aerogel topcoat, making the surface of the topcoat smooth and beautiful, and at the same time having a high solar reflectance and near-infrared reflectance, and a remarkable heat-insulating and heat-preserving effect.

[0048] The preparation method of the heat-insulating coating provided by the present invention is simple and efficient in process.

[0049] The application of the heat-insulating coating provided by the present invention has the characteristics of a smooth and shiny surface coating appearance and a silky feel. At the same time, it also has an excellent heat preservation effect. It can be used as a radiation coating on the inner wall and as a reflective coating on the outer wall, with remarkable energy-saving effects. Specific Embodiments

[0050] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0051] According to the first aspect of the present invention, a fluorine-modified silica aerogel is provided, which is mainly prepared from the following components in parts by mass:

[0052] 6-12 parts of tetraethyl orthosilicate, 2-4 parts of methacryloxypropyltrimethoxysilane, and 4-8 parts of vinylidene fluoride.

[0053] In the present invention, the typical but non-limiting parts by mass of tetraethyl orthosilicate are, for example, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts; the typical but non-limiting parts by mass of methacryloxypropyltrimethoxysilane are, for example, 2 parts, 3 parts, 4 parts; the typical but non-limiting parts by mass of vinylidene fluoride are, for example, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts.

[0054] The fluorine-modified silica aerogel provided by the present invention has the advantage of high strength under the synergistic cooperation of specific raw material components and their ratios, with excellent performance. When applied to the aerogel surface coating paint and used in combination with inorganic film-forming substances, it can solve the problems of collapse and particle feeling generated by the aerogel surface coating, making the surface coating smooth and beautiful, and having a significant heat insulation and heat preservation effect.

[0055] According to the second aspect of the present invention, a preparation method of a fluorine-modified silica aerogel is provided, including the following steps:

[0056] (a) Tetraethyl orthosilicate is acid-dissolved to obtain a silicic acid solution, and then the pH is adjusted and aged to obtain a silica gel;

[0057] (b) The silica gel obtained in step (a) undergoes a transesterification reaction with the methoxy group of methacryloxypropyltrimethoxysilane to obtain a silica gel modified with methacryloxypropyltrimethoxysilane on the surface;

[0058] (c) The silica gel obtained in step (b) whose surface is modified by methacryloxypropyltrimethoxysilane is polymerized with vinylidene fluoride to obtain fluorine-modified silica aerogel.

[0059] The method for preparing fluorine-modified silica aerogel provided by the present invention has simple process and high efficiency.

[0060] In a preferred embodiment, in the preparation method of the present invention, the pH value adjusted in step (a) can be 5-6, for example, 5, 5.5, 6, but not limited thereto, which is more conducive to the formation of silica gel.

[0061] In a preferred embodiment, in the preparation method of the present invention, the temperature of the acetal reaction in step (b) can be 40-60°C, for example, 40°C, 50°C, 60°C, but not limited thereto, which is more conducive to the formation of Si-O-Si bonds.

[0062] In a preferred embodiment, in the preparation method of the present invention, the temperature of the polymerization reaction in step (c) can be 70-80°C, for example, 70°C, 75°C, 80°C, but not limited thereto, which is more conducive to improving the polymerization reaction effect of silicone gel and vinylidene fluoride.

[0063] In a preferred embodiment, in the preparation method of the present invention, step (c) comprises the following steps:

[0064] The silica gel obtained in step (b) with its surface modified by methacryloxypropyltrimethoxysilane is immersed in an alcohol solution of vinylidene fluoride, and then ammonium persulfate is added, followed by polymerization reaction to obtain fluorine-modified silica aerogel.

[0065] A typical preparation method of fluorine-modified silica aerogel comprises the following steps:

[0066] S1: Take tetraethyl orthosilicate as a precursor, dilute it with water and stir it thoroughly, then add hydrochloric acid to dissolve it to obtain a silicic acid solution, control the pH at 1-2, and wash out impurities with water;

[0067] S2: adding an ammonia solution to the silicic acid solution obtained in step S1, adjusting the pH of the silicic acid solution to 5-6, stirring and mixing, pouring into a mold, standing at room temperature to convert it into a silica gel, standing and aging, and then taking it out and immersing it in an ethanol solution;

[0068] S3: Dissolve 3 - (Methacryloyloxy)propyltrimethoxysilane in an ethanol solution to obtain a mixed solution. Immerse the silica gel obtained in step S2 in the 3 - (Methacryloyloxy)propyltrimethoxysilane mixed solution, and carry out a reaction by heating in a water bath, so that the methoxy groups of the 3 - (Methacryloyloxy)propyltrimethoxysilane molecules directly undergo a transesterification reaction with the Si - OH on the surface of the silica gel particles to form Si - O - Si bonds;

[0069] After that, wash the silica gel with ethanol to remove the residual 3 - (Methacryloyloxy)propyltrimethoxysilane solution. Immerse the silica gel modified by 3 - (Methacryloyloxy)propyltrimethoxysilane molecules in an ethanol solution of vinylidene fluoride monomer, then add an ethanol solution of ammonium persulfate, heat after immersion for polymerization, convert the silica gel into a white opaque state, then dry it at room temperature and further dry it under vacuum to obtain a fluorine - modified silica aerogel.

[0070] The preparation method of the fluorine - modified silica aerogel provided by the present invention can successfully prepare the fluorine - modified silica aerogel, which has the advantage of high strength. When it is used in combination with an inorganic film - forming substance, it can cooperate synergistically to avoid the collapse phenomenon of the aerogel topcoat, and can reduce the particle feeling of the topcoat, making the surface of the topcoat smooth, beautiful, and having a good heat insulation and heat preservation effect.

[0071] According to the third aspect of the present invention, there is provided an application of the above - mentioned fluorine - modified silica aerogel in the preparation of a heat - insulating coating.

[0072] The application of the fluorine - modified silica aerogel provided by the present invention has the characteristic of high strength. It can make the appearance of the topcoat paint of the heat - insulating coating flat and shiny, with a smooth silk - like feel, solve the technical problems of the collapse and too heavy particle feeling of the aerogel topcoat paint, and achieve the technical effects of smooth and beautiful topcoat paint, high solar reflectance and near - infrared reflectance, and good heat insulation and heat preservation.

[0073] According to the fourth aspect of the present invention, there is provided a heat - insulating coating, which comprises the following components:

[0074] Cellulose, titanium dioxide, filler, auxiliary agent, the above - mentioned fluorine - modified silica aerogel, silicate, acrylic emulsion, and water.

[0075] The heat - insulating coating provided by the present invention, through the particle overlapping technology, uses the fluorine - modified silica aerogel in combination with an inorganic film - forming substance and other components, and cooperates synergistically, can avoid the collapse phenomenon of the aerogel topcoat, and reduce the particle feeling of the topcoat, thereby solving the problems of the collapse and too heavy particle feeling of the aerogel topcoat paint, making the surface of the topcoat smooth and beautiful, and at the same time having a high solar reflectance and near - infrared reflectance, and a significant heat insulation and heat preservation effect.

[0076] In a preferred embodiment, the cellulose in the present invention includes, but is not limited to, hydroxyethyl cellulose and hydroxymethyl cellulose, which is beneficial to improving the interlayer continuity of the coating;

[0077] In a preferred embodiment, the titanium dioxide in the present invention includes, but is not limited to, rutile titanium dioxide and anatase titanium dioxide, which is beneficial to improving the surface flatness of the heat-insulating coating.

[0078] In the present invention, the specific type of the filler is not particularly limited. For example, it can be at least one of heavy calcium, kaolin, talcum powder, and titanium dioxide, but not limited thereto, which is beneficial to further improving the performance of the heat-insulating coating.

[0079] In the present invention, the additives are not particularly restricted. For example, they can be at least one of dispersants, wetting agents, thickeners, defoamers, preservatives, pH regulators, film-forming aids, and antifreeze agents, but not limited thereto. Among them, the types and specific substances of the dispersants, wetting agents, thickeners, defoamers, preservatives, pH regulators, film-forming aids, and antifreeze agents are not particularly restricted, and those common in the art can be used in the present invention.

[0080] In a preferred embodiment, the particle size of the fluorine-modified silica aerogel in the present invention is 20 - 100 nm, and its typical but non-limiting particle sizes are, for example, 20 nm, 50 nm, 65 nm, 75 nm, 80 nm, 95 nm, 100 nm, which is more beneficial to solving the problems of collapse and too heavy particle feeling of the topcoat paint of the aerogel, further improving the appearance performance of the topcoat paint, making it flat and shiny, with a smooth feel, enabling the topcoat paint to have a high solar reflectance and near-infrared reflectance, and having a good heat insulation and heat preservation effect.

[0081] In a preferred embodiment, the silicate in the present invention includes, but is not limited to, at least one of potassium silicate, lithium silicate, and sodium silicate. For example, modified potassium silicate can be selected, but not limited thereto, which is beneficial to improving the film-forming performance of the heat-insulating coating, and can more effectively act together with the fluorine-modified silica aerogel to achieve a synergistic effect, further improving the surface flatness and smoothness and heat insulation and heat preservation effect of the heat-insulating coating.

[0082] In a preferred embodiment, the heat-reflective and heat-insulating coating of the present invention comprises the following components by mass parts: cellulose 0.1 - 0.3 part, rutile titanium dioxide 15 - 25 parts, filler 5 - 15 parts, additive 1 - 7 parts, fluorine-modified silica aerogel 5 - 20 parts, modified potassium silicate 10 - 15 parts, acrylic emulsion 1 - 5 parts, and water 10 - 15 parts.

[0083] In the present invention, the typical but non-limiting mass parts of cellulose are, for example, 0.1 part, 0.2 part, 0.3 part; the typical but non-limiting mass parts of rutile titanium dioxide are, for example, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts; the typical but non-limiting mass parts of fillers are, for example, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts; the typical but non-limiting mass parts of additives are, for example, 1 part, 2 part, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts; the typical but non-limiting mass parts of fluorine-modified silica aerogel are, for example, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts; the typical but non-limiting mass parts of modified potassium silicate are, for example, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts; the typical but non-limiting mass parts of acrylic emulsion are, for example, 1 part, 2 parts, 3 parts, 4 parts, 5 parts; the typical but non-limiting mass parts of water are, for example, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts.

[0084] The components and their mass parts selected in the present invention are more conducive to improving the synergistic cooperation effect of each component, so as to further improve the surface smoothness and heat insulation effect of the heat insulation coating.

[0085] In a preferred embodiment, the additives include the following components by mass parts:

[0086] 0.5 - 1.5 parts of dispersant, 0.2 - 0.5 parts of wetting agent, 0.2 - 0.5 parts of thickener, 0.3 - 0.6 parts of defoamer, 0.1 - 0.3 parts of preservative, 0.1 - 0.3 parts of pH regulator, 0.5 - 2 parts of film-forming aid, and 1 - 2 parts of antifreeze.

[0087] For the heat insulation coating provided by the present invention, the fluorine-modified silica aerogel is used in combination with the inorganic film-forming substance and other components, and the components and their mass ratios have a synergistic cooperation effect. Through the particle overlapping technology, the collapse of the aerogel topcoat and the particle feeling of the topcoat can be avoided, thereby solving the problems of the collapse and too heavy particle feeling of the aerogel topcoat paint, making the surface of the topcoat smooth and beautiful, and at the same time having a high solar reflectance and near-infrared reflectance, and the heat insulation effect is remarkable.

[0088] According to the fifth aspect of the present invention, a preparation method of a heat insulation coating is provided, including the following steps:

[0089] Mix each component to obtain the heat insulation coating.

[0090] The preparation method of the heat insulation coating provided by the present invention is simple and efficient in process.

[0091] In a preferred embodiment, the preparation method of the present invention comprises the following steps:

[0092] Mix water and cellulose, then add titanium dioxide and filler and mix, then add additives and mix, then add fluorine-modified silica aerogel and mix, and then add silicate and acrylic emulsion to obtain the heat-insulating coating.

[0093] A typical preparation method of a heat-insulating coating comprises the following steps:

[0094] Place deionized water in a dispersion tank, adjust the dispersion speed to 600 - 800 r / min, slowly add cellulose powder, and when the viscosity of the solution in the tank increases, add rutile titanium dioxide and filler, then increase the speed to 1000 - 1500 r / min and disperse for 30 min;

[0095] Add additives and disperse for 5 min;

[0096] Reduce the speed to 800 - 1000 r / min, add fluorine-modified silica aerogel, disperse for 15 min, and finally add modified potassium silicate and acrylic emulsion, disperse for 10 min and discharge to obtain the heat-insulating coating.

[0097] The preparation method of the heat-insulating coating provided by the present invention can fully mix each component and play a synergistic role, thereby ensuring the smoothness and heat-insulating and heat-preserving properties of the surface of the heat-insulating coating, obtaining a heat-insulating coating with more prominent comprehensive performance, and being applicable to actual production.

[0098] According to the sixth aspect of the present invention, there is provided an application of a heat-insulating coating in building insulation.

[0099] The application of the heat-insulating coating provided by the present invention has the characteristics of smooth and shiny surface coating appearance and silky feel, and at the same time has excellent heat-insulating effect. It can be used as a radiation coating on the inner wall and as a reflective coating on the outer wall, with remarkable energy-saving effect.

[0100] The present invention will be further described below through examples. Unless otherwise specified, the materials in the examples are prepared according to the existing methods or directly purchased from the market.

[0101] Example 1

[0102] A heat-insulating coating is mainly prepared from the following components by weight:

[0103] 10 parts of deionized water, 0.1 part of cellulose, 15 parts of rutile titanium dioxide, 5 parts of filler, 1 part of additive, 5 parts of fluorine-modified silica aerogel, 10 parts of modified potassium silicate, and 1 part of acrylic emulsion;

[0104] Among them, the cellulose is hydroxyethyl cellulose;

[0105] The fillers are rutile titanium dioxide, 800-mesh kaolin, and 1250-mesh AB heavy calcium carbonate;

[0106] The additives include: 1.0 part of dispersant, 0.3 part of wetting agent, 0.3 part of thickener, 0.3 part of defoamer, 0.3 part of preservative, 0.1 part of pH regulator, 2 parts of film-forming aid, and 1 part of antifreeze;

[0107] The dispersant is AB2248, the wetting agent is LFH, the thickener is B3OK, the defoamer is AGITAN109, the preservative is BM6E, the pH regulator is 45% KOH, the film-forming aid is CL3101, and the antifreeze is propylene glycol.

[0108] The particle size of the fluorine-modified silica aerogel is 45 nm;

[0109] The preparation method of the fluorine-modified silica aerogel in this example includes the following steps:

[0110] S1: Using tetraethyl orthosilicate as a precursor, diluting it with deionized water at a volume ratio of 3:1 and stirring well, then adding hydrochloric acid to dissolve it to obtain a silicic acid solution, controlling the pH value at 1 - 2, and washing out impurities with water;

[0111] S2: Adding 1 mol / L ammonia water solution to the silicic acid solution obtained in step S1, adjusting the pH value of the silicic acid solution to 5 - 6, stirring for 1 min and then pouring it into a mold, standing at room temperature to convert it into a silica gel, and standing and aging for 24 h, taking it out and transferring it to a 50% ethanol solution to soak for 24 h, and replacing the ethanol solution every 8 h during this period;

[0112] S3: Dissolving methacryloxypropyltrimethoxysilane in an ethanol solution to prepare a 50% mixed solution, soaking the silica gel obtained in step S2 in the methacryloxypropyltrimethoxysilane mixed solution for 24 h, then heating and reacting in a water bath at 50 °C, so that the methoxy groups of the methacryloxypropyltrimethoxysilane molecules directly undergo a transesterification reaction with the Si-OH on the surface of the silica gel particles to form Si-O-Si bonds;

[0113] After that, washing the silica gel with ethanol to remove the residual methacryloxypropyltrimethoxysilane solution, then soaking the silica gel modified by methacryloxypropyltrimethoxysilane molecules in a 50% ethanol solution of vinylidene fluoride monomer for 24 h, adding an ethanol solution of ammonium persulfate, soaking for 2 h, then heating to 75 °C for polymerization to convert the silica gel into a white opaque state, then drying at room temperature for 24 h, and then drying under 50% vacuum for 24 h to obtain the fluorine-modified silica aerogel;

[0114] Among them, the mass ratio of tetraethyl orthosilicate, methacryloxypropyltrimethoxysilane, and vinylidene fluoride is 6:2:4.

[0115] Examples 2 - 5

[0116] Examples 2 - 5 provide a heat-insulating coating. The difference from Example 1 is that the weight parts of the fluorine-modified silica aerogel in Examples 2 - 5 are 3 parts, 10 parts, 15 parts, and 20 parts in sequence, and the other components and their weight parts are the same as those in Example 1.

[0117] Examples 6 - 7

[0118] Examples 6 - 7 provide a heat-insulating coating. The difference from Example 1 is that the weight parts of the modified potassium silicate in Examples 6 - 7 are 5 parts and 15 parts in sequence, and the other components and their weight parts are the same as those in Example 1.

[0119] Example 8

[0120] This example provides a heat-insulating coating. The difference from Example 1 is that the particle size of the fluorine-modified silica aerogel in the reflective coating of this example is 80 nm, and the other components and their weight parts are the same as those in Example 1.

[0121] Example 9

[0122] This example provides a heat-insulating coating. The difference from Example 1 is that the mass ratio of tetraethyl orthosilicate, methacryloxypropyltrimethoxysilane, and vinylidene fluoride in the preparation method of the fluorine-modified silica aerogel in this example is 6:2:8, and the other components and their weight parts are the same as those in Example 1.

[0123] Example 10

[0124] A heat-insulating coating is mainly prepared from the following components by weight:

[0125] 12 parts of deionized water, 0.2 part of cellulose, 20 parts of rutile titanium dioxide, 10 parts of filler, 4 parts of auxiliary agent, 13 parts of fluorine-modified silica aerogel, 12 parts of modified potassium silicate, and 3 parts of acrylic emulsion;

[0126] The rest are the same as those in Example 1.

[0127] Example 11

[0128] A heat-insulating coating is mainly prepared from the following components by weight:

[0129] 15 parts of deionized water, 0.3 parts of cellulose, 25 parts of rutile titanium dioxide, 15 parts of filler, 7 parts of additive, 20 parts of fluorine-modified silica aerogel, 15 parts of modified potassium silicate, and 5 parts of acrylic emulsion;

[0130] The rest are the same as those in Example 1.

[0131] Example 12

[0132] The preparation method of the heat-insulating coating in this example is for Examples 1-11 and includes the following steps:

[0133] Place the deionized water in a dispersion tank, adjust the dispersion speed to 600-800 r / min, slowly add cellulose, and when the viscosity of the solution in the tank increases, add rutile titanium dioxide and filler, then increase the speed to 1000-1500 r / min, disperse for 30 min, then add the additive and disperse for 5 min, then reduce the speed to 800-1000 r / min, add fluorine-modified silica aerogel, disperse for 15 min, and finally add modified potassium silicate and acrylic emulsion, disperse for 10 min and discharge to obtain the heat-insulating coating.

[0134] Comparative Example 1

[0135] The difference between this comparative example and Example 1 is that in step S3 of the preparation method of the aerogel in this comparative example, vinylidene fluoride is not used for modification, so unfluorinated silica aerogel is obtained and added to the reflective coating, and the rest are the same as those in Example 1 to obtain the coating.

[0136] Comparative Example 2

[0137] The difference between this comparative example and Example 1 is that the reflective coating in this comparative example does not contain fluorine-modified silica aerogel, and the rest are the same as those in Example 1 to obtain the coating.

[0138] Test Example 1

[0139] The coatings provided in Examples 1-11 and Comparative Examples 1-2 are made into paint films, and tests on surface effect, heat-insulating temperature difference, solar reflectance, and near-infrared reflectance are carried out, and the results are shown in Table 1.

[0140] The test method for the heat-insulating temperature difference is in accordance with the standard of GB / T 25261-2018;

[0141] The test method for the solar reflectance is in accordance with the standard of JG / T 235-2014;

[0142] The test method for the near-infrared reflectance is in accordance with the standard of JG / T 235-2014.

[0143] Table 1 Test data

[0144]

[0145]

[0146] As can be seen from Table 1, adding silica aerogel to the inorganic heat-insulating coating can make the appearance of the coating smoother and more even, and at the same time, the heat-insulating performance is better; further, the comprehensive performance of the heat-insulating coating after adding fluorine-modified silica aerogel is significantly better than that of the heat-insulating coating after adding unmodified silica aerogel; at the same time, when the weight ratio of the components in the heat-insulating coating is within the preferred range of the present invention, the performance of the heat-insulating coating is further improved, and when the weight ratio of the components in the heat-insulating coating is too high or too low, this effect cannot be achieved.

[0147] Therefore, for the heat-insulating coating provided by the present invention, the fluorine-modified silica aerogel is used in combination with the inorganic film-forming substance and other components, and the components and their mass ratios have a synergistic effect. Through the particle overlapping technology, the collapse of the aerogel topcoat and the particle feeling of the topcoat can be avoided, thereby solving the problems of the collapse and too heavy particle feeling of the aerogel topcoat paint, making the surface of the topcoat smooth and beautiful, and at the same time having a high solar reflectance and near-infrared reflectance, and the heat-insulating and heat-preserving effect is remarkable.

[0148] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A heat-insulating coating, characterized in that, It comprises the following components by mass parts: Cellulose 0.1 - 0.3 parts, rutile titanium dioxide 15 - 25 parts, filler 5 - 15 parts, auxiliary agent 1 - 7 parts, fluorine-modified silica aerogel 5 - 20 parts, modified potassium silicate 10 - 15 parts, acrylic emulsion 1 - 5 parts, and water 10 - 15 parts; The filler includes at least one of heavy calcium, kaolin, talc powder, and titanium dioxide; The auxiliary agent includes at least one of dispersant, wetting agent, thickening agent, defoaming agent, preservative, pH regulator, film-forming auxiliary agent, and antifreezing agent; The fluorine-modified silica aerogel is mainly prepared from the following components by mass parts: Ethyl orthosilicate 6 - 12 parts, 3-(Trimethoxysilyl)propyl methacrylate 2 - 4 parts, and vinylidene fluoride 4 - 8 parts.

2. The heat-insulating coating according to claim 1, wherein The cellulose includes at least one of hydroxyethyl cellulose and hydroxymethyl cellulose.

3. The heat-insulating coating according to claim 1, characterized in that, The particle size of the fluorine-modified silica aerogel is 20 - 100 nm.

4. The heat-insulating coating according to claim 1, characterized in that, The auxiliary agent includes the following components by mass parts: Dispersant 0.5 - 1.5 parts, wetting agent 0.2 - 0.5 parts, thickening agent 0.2 - 0.5 parts, defoaming agent 0.3 - 0.6 parts, preservative 0.1 - 0.3 parts, pH regulator 0.1 - 0.3 parts, film-forming auxiliary agent 0.5 - 2 parts, and antifreezing agent 1 - 2 parts.

5. A method for preparing the heat-insulating coating according to any one of claims 1-4, characterized in that, It includes the following steps: After mixing water and cellulose, then adding titanium dioxide and filler and mixing, then adding auxiliary agent and mixing, then adding fluorine-modified silica aerogel and mixing, and then adding silicate and acrylic emulsion to obtain the heat-insulating coating.

6. Application of the heat-insulating coating according to any one of claims 1 - 4 in building insulation.

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