Thermal and sound insulation aerogel coating and method of preparation

Abstract

The application provides a heat and sound insulation aerogel coating and a preparation method. The coating realizes a double heat insulation mechanism through compounding of hydrophobic silica aerogel and hollow fillers, synergistically enhances, and reduces the thermal conductivity of the coating. The hollow fillers and fibers are compounded and used to achieve the sound insulation and sound absorption effects. The hydrophobic silica aerogel and the dense film-forming material jointly act to make the coating film have excellent hydrophobicity, a high contact angle, and difficult rainwater infiltration. The coating in the application is a water-based coating, can be applied by roll coating, brushing or spraying, is environment-friendly, and is suitable for new buildings and energy-saving reconstruction of old buildings.

Description

Technical Field

[0001] This invention belongs to the field of aerogel coating technology, and relates to a thermal insulation and soundproofing aerogel coating and its preparation method. Background Technology

[0002] With increasingly stringent requirements for building energy conservation and industrial insulation, the demand for high-performance thermal insulation materials is growing. Traditional thermal insulation materials such as polystyrene boards and rock wool suffer from problems such as complex construction, numerous seams, susceptibility to moisture absorption, and low fire resistance. Coatings, as a convenient construction material, are widely used in the construction and industrial sectors.

[0003] Aerogel, a novel material with a nanoporous network structure, is hailed as the lightest solid in the world. It boasts extremely low thermal conductivity, high specific surface area, and excellent sound insulation properties, making it an ideal and highly efficient thermal insulation material. However, applying aerogel to coatings presents the following technical challenges: 1) Aerogels have extremely low density, making them prone to agglomeration and floating in coating systems, resulting in poor dispersibility, unstable coating storage, and uneven coating performance; 2) Aerogels have low mechanical strength, making them easily damaged by shear forces during coating preparation and application, losing their nanoporous structure and leading to decreased sound and heat insulation performance; 3) Silica aerogels are hydrophilic, and their thermal conductivity increases significantly after moisture absorption, affecting long-term thermal insulation performance; 4) Coatings containing a large number of loose aerogel particles have low adhesion to the substrate, leading to easy film detachment after coating. Summary of the Invention

[0004] The purpose of this invention is to provide a thermal insulation and sound insulation aerogel coating and its preparation method, so as to solve the problem of poor thermal insulation and sound insulation performance when preparing coatings from aerogel.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: This application provides a thermal insulation and soundproofing aerogel coating, which comprises, by weight, 20-40 parts of film-forming material, 5-25 parts of aerogel particles, 10-30 parts of hollow filler, 15-30 parts of fiber, 5-10 parts of dispersant, 2-5 parts of wetting agent, 2-5 parts of defoamer, 4-8 parts of thickener, 4-8 parts of film-forming aid, 3-7 parts of preservative, and 20-40 parts of deionized water.

[0006] This application also provides a method for preparing a thermal insulation and soundproofing aerogel coating, the method comprising: At a speed of 300-500 rpm / min, add dispersant, wetting agent, and half of the defoamer to deionized water, stir and mix well, then slowly add aerogel particles, hollow filler, and fiber, and stir and disperse at a speed of 1000-1500 rpm / min to form a mixture. At a speed of 300-500 rpm / min, film-forming materials and film-forming aids are added to the mixture and stirred evenly. Then, thickener, the other half of the defoamer and preservative are added and stirred evenly to form a thermal insulation and soundproofing aerogel coating.

[0007] The present invention has the following beneficial effects: (1) Excellent thermal insulation performance: The combination of hydrophobic silica aerogel and hollow filler forms a dual thermal insulation mechanism of nano-micro-nano-scale pores or micro-nano-micro-scale pores, which synergistically enhances the effect, resulting in a thermal conductivity of the coating of less than 0.035 W / (m·K).

[0008] (2) Excellent sound insulation performance: Hollow filler can complicate the sound wave path, increase the sound wave transmission distance, and cause the sound energy to attenuate in repeated refraction, thus achieving the purpose of sound insulation; when the sound wave hits the outer wall of the hollow filler, it will cause a small resonance of the thin wall, which will consume some of the sound energy through resonance; there are a large number of micropores inside the fiber. After the sound wave enters the micropores, it will cause air vibration, which will absorb sound through the porous structure. Therefore, the sound insulation and sound absorption effects are achieved by using hollow filler and hemp fiber in combination.

[0009] (3) Good dispersibility and stability: The aerogel particles are hydrophobic silica aerogel powder with surface modification treatment, which effectively prevents the agglomeration and floating of aerogel, and ensures the storage stability of the product and the uniformity of the coating performance.

[0010] (4) Waterproofing: The hydrophobic silica aerogel and the dense film-forming material work together to give the coating excellent water repellency, high contact angle, and difficulty in rainwater penetration.

[0011] (5) Adhesion: High-performance emulsion is selected as the film-forming substance to ensure the adhesion between the coating and various substrates such as cement mortar, metal, and ceramics, and to prevent peeling.

[0012] (6) Convenient construction: This product is a water-based coating and can be applied by roller coating, brush coating or spraying. It is environmentally friendly and suitable for energy-saving renovation of new buildings and old buildings. Detailed Implementation

[0013] This application provides a thermal insulation and soundproofing aerogel coating, which comprises, by weight, the following components: 20-40 parts film-forming material, 5-25 parts aerogel particles, 10-30 parts hollow filler, 15-30 parts fiber, 5-10 parts dispersant, 2-5 parts wetting agent, 2-5 parts defoamer, 4-8 parts thickener, 4-8 parts film-forming aid, 3-7 parts preservative, and 20-40 parts deionized water.

[0014] In the embodiments of this application, the film-forming material includes one or more of pure acrylic emulsion, silicone acrylic emulsion, acrylate emulsion, elastic emulsion, and organosilicon-modified resin; the film-forming aid includes one or more of dodecyl alcohol ester, dimethyl phthalate, and dipropylene glycol methyl ether. The film-forming material and film-forming aid help the thermal insulation and soundproofing aerogel coating to form a film more easily after application. Preferably, the film-forming material is an elastic emulsion or acrylate emulsion, wherein the elastic emulsion refers to a copolymer emulsion formed by acrylate and organosilicon copolymer, to improve the weather resistance and crack resistance of the coating film through the flexibility of the cured film layer.

[0015] In this embodiment, the aerogel particles are surface-modified hydrophobic silica aerogel powder with a particle size of 10-100 μm and a contact angle >150°. The hollow filler includes one or more of hollow glass microspheres, ceramic microspheres, and cenospheres, with a particle size of 20-150 μm and a hollow inner diameter of 5-80 μm. The hydrophobic silica aerogel is hydrophobic fumed silica, and its nanopores have thermal insulation properties, which can improve the thermal insulation of the coating. The hollow filler is a hollow microsphere with rarefied air or vacuum inside its micron-sized pores, which can form a thermal insulation space and improve the thermal insulation of the coating. Thus, the combination of hydrophobic silica aerogel and hollow filler forms a dual thermal insulation mechanism of nano-micron-nano-sized pores or micron-nano-micron-sized pores, which synergistically enhances the effect, resulting in a thermal conductivity of the coating of less than 0.035 W / (m·K).

[0016] In this embodiment, the hollow filler also possesses sound insulation properties. When sound waves enter the coating, they bypass countless tiny spheres. This complex path significantly increases the transmission distance of the sound waves, causing the sound energy to attenuate through repeated refraction, thus achieving sound insulation. Furthermore, when sound waves impact the outer wall of the hollow filler, they induce micro-resonance in the thin wall, consuming some of the sound energy and further enhancing sound insulation.

[0017] This application embodiment also uses hemp fiber, which has sound-absorbing properties. Hemp fiber contains numerous micropores; when sound waves enter these micropores, they cause air vibrations, thus absorbing sound through the porous structure. Furthermore, when sound waves come into contact with the fiber surface, air molecules rub against the hemp fiber surface, converting sound energy into heat energy, achieving the purpose of sound absorption. In this application embodiment, the hemp fiber is selected from one or more of glass fiber, aluminosilicate fiber, and wood fiber, with a fiber length of 10-25 mm, which is beneficial for fiber dispersion in the coating.

[0018] Dispersants, wetting agents, defoamers, thickeners, and preservatives are the additives in the embodiments of this application, each performing its respective function. In the embodiments of this application, the dispersant includes one or more of polycarboxylate, sodium hexametaphosphate, sodium tripolyphosphate, and sodium polyacrylate; the wetting agent includes one or more of sodium dodecyl sulfate, succinate sulfonate, polyether-modified polydimethylsiloxane, and perfluorooctyl sulfonate; the defoamer includes one or more of polydimethylsiloxane, polyoxypropylene polyoxyethylene ether, and stearic acid; the thickener includes one or more of hydroxyethyl cellulose, methyl cellulose, hydrophobically modified polyurethane, xanthan gum, and gelatin; and the preservative includes one or more of isothiazolinone, quaternary ammonium salt, 1,2-benzisothiazolin-3-one, and 2-bromo-2-nitro-1,3-propanediol.

[0019] A preferred embodiment of the thermal insulation and soundproofing aerogel coating comprises, by weight, 35 parts film-forming material, 20 parts aerogel particles, 15 parts hollow filler, 20 parts fiber, 8 parts dispersant, 4 parts wetting agent, 3 parts defoamer, 5 parts thickener, 5 parts film-forming aid, 5 parts preservative, and 30 parts deionized water.

[0020] In addition, this application embodiment also provides a method for preparing a thermal insulation and soundproofing aerogel coating, the method comprising: S01: Under low-speed stirring at 300-500 rpm / min, add dispersant, wetting agent, and half of the defoamer to deionized water, stir and mix well, then slowly add aerogel particles, hollow filler, and fiber, and stir and disperse under high-speed stirring at 1000-1500 rpm / min to form a mixture.

[0021] S02: After reducing the rotation speed to 300-500 rpm / min, add the film-forming material and film-forming aid to the mixture and stir evenly. Then add the thickener, the other half of the defoamer and preservative, and stir evenly to form a thermal insulation and sound insulation aerogel coating in a rheological state.

[0022] The technical solution of the present invention will be further explained and described below through specific embodiments.

[0023] Example 1 This application provides a thermal insulation and soundproofing aerogel coating, which comprises, by weight, the following: 20 parts of acrylic emulsion, 15 parts of hydrophobic silica aerogel powder with a particle size of 50 μm, 15 parts of hollow glass microspheres with a particle size of 80 μm and a hollow inner diameter of 40 μm, 10 parts of glass fiber, 10 parts of ramie fiber, 10 parts of polycarboxylate, 2 parts of sodium dodecyl sulfate, 2 parts of stearic acid, 4 parts of hydroxyethyl cellulose, 8 parts of dodecyl alcohol ester, 3 parts of isothiazolinone, and 40 parts of deionized water.

[0024] This application also provides a method for preparing a thermal insulation and soundproofing aerogel coating, the method comprising: S101: Under low-speed stirring at 400 rpm / min, add polycarboxylate, sodium dodecyl sulfate, and half of the stearic acid to deionized water. After stirring and mixing, slowly add hydrophobic silica aerogel powder, hollow glass microspheres, glass fiber, and ramie fiber. Stir and disperse under high-speed stirring at 1200 rpm / min to form a mixture.

[0025] S102: After reducing the rotation speed to 400 rpm / min, add acrylate emulsion and dodecyl alcohol ester to the mixture and stir evenly. Then add hydroxyethyl cellulose, the other half of the stearic acid and preservative, and stir evenly to form a thermal insulation and sound insulation aerogel coating in a rheological state.

[0026] Example 2 This application provides a thermal insulation and soundproofing aerogel coating, which comprises, by weight, the following: 35 parts of elastic emulsion, 20 parts of hydrophobic silica aerogel powder with a particle size of 30 μm, 15 parts of ceramic microspheres with a particle size of 50 μm and a hollow inner diameter of 10 μm, 20 parts of glass fiber, 8 parts of sodium hexametaphosphate, 4 parts of succinate sulfonate, 3 parts of stearic acid, 5 parts of methylcellulose, 5 parts of dodecyl alcohol ester, 5 parts of quaternary ammonium salt, and 30 parts of deionized water. This application also provides a method for preparing a thermal insulation and soundproofing aerogel coating, which is the same as in Example 1.

[0027] Example 3 This application provides a thermal insulation and soundproofing aerogel coating, which comprises, by weight, the following: 40 parts of silicone-acrylic emulsion, 25 parts of hydrophobic silica aerogel powder with a particle size of 10 μm, 30 parts of cenospheres with a particle size of 20 μm and a hollow inner diameter of 5 μm, 2 parts of wood fiber, 21 parts of aluminum silicate fiber, 8 parts of sodium tripolyphosphate, 5 parts of polyether-modified polydimethylsiloxane, 3 parts of polyoxypropylene polyoxyethylene ether, 5 parts of hydrophobic modified polyurethane, 5 parts of dimethyl phthalate, 3 parts of 1,2-benzisothiazolin-3-one, and 20 parts of deionized water.

[0028] This application also provides a method for preparing a thermal insulation and soundproofing aerogel coating, which is the same as in Example 1.

[0029] Example 4 This application provides a thermal insulation and soundproofing aerogel coating, which comprises, by weight, the following: 30 parts of pure acrylic emulsion, 15 parts of hydrophobic silica aerogel powder with a particle size of 100 μm, 20 parts of hollow glass microspheres with a particle size of 150 μm and a hollow inner diameter of 80 μm, 15 parts of aluminum silicate fiber, 7 parts of sodium polyacrylate, 3 parts of perfluorooctyl sulfonate, 3 parts of polydimethylsiloxane, 6 parts of xanthan gum, 5 parts of dipropylene glycol methyl ether, 6 parts of 2-bromo-2-nitro-1,3-propanediol, and 35 parts of deionized water.

[0030] This application also provides a method for preparing a thermal insulation and soundproofing aerogel coating, which is the same as in Example 1.

[0031] Comparative Example 1 This application provides a coating as a comparative example, which is the same as that in Example 1, except that hydrophobic silica aerogel powder is not added.

[0032] Comparative Example 2 This application provides a coating as a comparative example, which is the same as that in Example 1, except that hollow glass microspheres are not added.

[0033] Comparative Example 3 This application provides a coating as a comparative example, which is the same as that in Example 1, except that no fibers are added.

[0034] In this application, the coatings prepared in Examples 1-4 and Comparative Examples 1-3 were fabricated and cured according to national standards, and their thermal conductivity, stain resistance, water absorption, adhesion, sound insulation, and storage stability (50℃ / 30d) were tested, resulting in Table 1.

[0035] Table 1: Performance Test Data As can be seen from Table 1, the coatings prepared in Examples 1-4 of this application have lower thermal conductivity and lower decibel values, and their stain resistance, water resistance, adhesion, and storage stability are all better than those of the comparative example. This indicates that the coatings prepared in the examples of this application have better thermal insulation and sound insulation properties.

[0036] Compared with Example 1, the thermal conductivity of the plates prepared by the coatings in Comparative Examples 1 and 2 is higher than that in Example 1. This indicates that although the addition of hydrophobic silica aerogel powder or hollow glass microspheres can reduce the thermal conductivity, it is still much higher than that in Example 1. This shows that the synergistic effect of hydrophobic silica aerogel powder and hollow glass microspheres can significantly reduce the thermal conductivity and achieve the effect of heat preservation.

[0037] Compared with Example 1, the decibel value of the board prepared by the coating of Example 3 was higher than that of Example 1, indicating that the addition of fiber can reduce the decibel level and achieve the effect of sound insulation.

[0038] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A thermal insulation and soundproofing aerogel coating, characterized in that, The components, by weight, are: 20-40 parts film-forming material, 5-25 parts aerogel particles, 10-30 parts hollow filler, 15-30 parts fiber, 5-10 parts dispersant, 2-5 parts wetting agent, 2-5 parts defoamer, 4-8 parts thickener, 4-8 parts film-forming aid, 3-7 parts preservative, and 20-40 parts deionized water.

2. The thermal insulation and soundproofing aerogel coating according to claim 1, characterized in that, The composition by weight is as follows: 35 parts film-forming material, 20 parts aerogel particles, 15 parts hollow filler, 20 parts fiber, 8 parts dispersant, 4 parts wetting agent, 3 parts defoamer, 5 parts thickener, 5 parts film-forming aid, 5 parts preservative, and 30 parts deionized water.

3. The thermal insulation and soundproofing aerogel coating according to claim 1, characterized in that, The film-forming material includes one or more of the following: pure acrylic emulsion, silicone acrylic emulsion, acrylate emulsion, elastic emulsion, and organosilicon modified resin.

4. The thermal insulation and soundproofing aerogel coating according to claim 1, characterized in that, The aerogel particles are hydrophobic silica aerogel powder with a particle size of 10-100 μm.

5. The thermal insulation and soundproofing aerogel coating according to claim 1, characterized in that, The hollow filler includes one or more of hollow glass microspheres, ceramic microspheres, and cenospheres, with a particle size of 20-150 μm and a hollow inner diameter of 5-80 μm.

6. The thermal insulation and soundproofing aerogel coating according to claim 1, characterized in that, The fiber includes one or more of glass fiber, aluminum silicate fiber, and wood fiber, and the fiber length is 10-25 mm.

7. The thermal insulation and soundproofing aerogel coating according to claim 1, characterized in that, The dispersant includes one or more of polycarboxylate, sodium hexametaphosphate, sodium tripolyphosphate, and sodium polyacrylate; the wetting agent includes one or more of sodium dodecyl sulfate, succinate sulfonate, polyether-modified polydimethylsiloxane, and perfluorooctyl sulfonate.

8. The thermal insulation and soundproofing aerogel coating according to claim 1, characterized in that, The defoamer includes one or more of polydimethylsiloxane, polyoxypropylene polyoxyethylene ether, and stearic acid; the thickener includes one or more of hydroxyethyl cellulose, methyl cellulose, hydrophobically modified polyurethane, xanthan gum, and gelatin.

9. The thermal insulation and soundproofing aerogel coating according to claim 1, characterized in that, The film-forming aid includes one or more of dodecyl alcohol ester, dimethyl phthalate, and dipropylene glycol methyl ether; the preservative includes one or more of isothiazolinone, quaternary ammonium salt, 1,2-benzisothiazolin-3-one, and 2-bromo-2-nitro-1,3-propanediol.

10. The method for preparing the thermal insulation and sound insulation aerogel coating according to any one of claims 1-9, characterized in that, include: At a speed of 300-500 rpm / min, add dispersant, wetting agent, and half of the defoamer to deionized water, stir and mix well, then slowly add aerogel particles, hollow filler, and fiber, and stir and disperse at a speed of 1000-1500 rpm / min to form a mixture. At a speed of 300-500 rpm / min, film-forming materials and film-forming aids are added to the mixture and stirred evenly. Then, thickener, the other half of the defoamer and preservative are added and stirred evenly to form a thermal insulation and soundproofing aerogel coating.

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