Thermal insulation coating and preparation method thereof

Abstract

The application provides a kind of heat insulation coating and its preparation method, belong to coating technical field, the coating of the application contains glass bead, ceramic fiber, alumina fiber, ammonium polyphosphate, rutile titanium dioxide, modified expanded vermiculite, modified halloysite powder, dimethyl silyl silicic stone, VP-methyl methacrylate dimethyl amino ethyl ester copolymer, nano aerogel etc. Component, has very good heat preservation effect, fireproof performance is improved, and heat preservation fire resistance effect is durable and stable. Modified expanded vermiculite, modified halloysite powder, dimethyl silyl silicic stone, VP-methyl methacrylate dimethyl amino ethyl ester copolymer, four are used with good synergies, can greatly improve the heat preservation performance of coating, can block heat conduction, play the role of heat insulation, simultaneously, also have excellent weather resistance, can waterproof, fireproof, corrosion resistant, under the complex and changeable climate conditions, maintain good performance state.

Description

Technical Field

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

[0002] As a new type of insulation material, thermal insulation coatings offer advantages such as easy construction, low cost, and excellent insulation effects, thus reducing energy consumption. Thermal insulation coatings have a wide range of applications, including the following: in the construction sector, they can be used for exterior wall insulation and roof insulation; in the industrial sector, they can be used for pipe insulation, storage tank insulation, and industrial equipment insulation; in the transportation sector, they can be used in areas such as the engine compartment to insulate and reduce noise; in addition, using thermal insulation coatings on the water tanks and pipes of solar water heaters can reduce heat loss and improve the efficiency of solar water heaters; they can also be used for the insulation and heat insulation of military facilities and equipment, improving their performance and reliability in harsh environments.

[0003] With the continuous advancement of technology, people's performance requirements for thermal insulation materials are becoming increasingly higher. Thermal insulation coatings must not only have excellent thermal insulation properties, but also be waterproof, fireproof, and corrosion-resistant. At the same time, to adapt to different application scenarios, thermal insulation coatings also need to have good workability and durability.

[0004] At present, there are many types of thermal insulation coatings on the market, with varying quality, and the following problems generally exist:

[0005] 1. Heat reflection is significantly affected by environmental factors: The performance of some heat-reflective insulation coatings is closely related to season, light intensity, and surface contamination. While they perform best in the summer when sunlight is strong, their reflective effect is significantly reduced in spring and autumn, on cloudy days, or at night. In winter, reflected solar heat may increase heat loss from buildings, making overall insulation performance unstable.

[0006] 2. The durability of thermal insulation needs to be improved: Over time, coatings may age, crack, and peel, leading to a gradual decline in thermal insulation performance. For example, thermal insulation coatings exposed outdoors for long periods of time are subject to erosion by natural factors such as ultraviolet rays, wind and rain, significantly impacting their thermal insulation performance.

[0007] 3. Fire resistance needs to be improved: Frequent building fires have placed higher demands on the fire resistance of insulation materials. Some thermal insulation coatings have poor fire resistance and are easily burned.

[0008] Therefore, it is necessary to develop and improve thermal insulation coatings with better thermal insulation, fire resistance, corrosion resistance, weather resistance, etc. to meet the increasingly higher usage requirements. Summary of the Invention

[0009] Aiming at the problems existing in thermal insulation coatings, such as the heat reflection effect being greatly affected by environmental factors, the durability of the thermal insulation effect being poor, and the fireproofing performance being in need of improvement, the present invention provides a thermal insulation coating and a preparation method thereof. The coating contains glass microbeads, ceramic fibers, alumina fibers, ammonium polyphosphate, rutile titanium dioxide, modified expanded vermiculite, modified halloysite powder, dimethyl silylated silica, VP-dimethylaminoethyl methacrylate copolymer, nano-aerogel and other ingredients. The coating has a good thermal insulation effect, improved fireproofing performance, and long-lasting and stable thermal insulation and fire-resistant effects. The specific technical scheme is as follows:

[0010] A thermal insulation coating comprises the following raw materials in parts by mass: 25 to 35 parts of glass microbeads, 12 to 20 parts of ceramic fibers, 4 to 8 parts of alumina fibers, 4 to 7 parts of ammonium polyphosphate, 3 to 6 parts of rutile titanium dioxide, 5 to 8 parts of modified expanded vermiculite, 5 to 10 parts of modified halloysite powder, 2 to 5 parts of silica dimethyl silylate, 6 to 10 parts of VP-dimethylaminoethyl methacrylate copolymer, 12 to 18 parts of nano aerogel, 20 to 30 parts of silicone resin, 3 to 4 parts of dispersant, 0.5 to 1 part of leveling agent, 1 to 3 parts of defoaming agent, 1 to 3 parts of fumed silica, and 10 to 15 parts of turpentine.

[0011] In the above-mentioned coating, the preparation method of the modified expanded vermiculite comprises the following steps: drying the expanded vermiculite at a temperature of 100°C to 120°C for 2h to 3h, adding the dried expanded vermiculite to the coating modifier at a ratio of expanded vermiculite to coating modifier = 1:(5-8), stirring at a temperature of 35°C to 45°C for 1h to 2h to obtain coated modified expanded vermiculite, centrifuging, taking the precipitate and drying it at 80°C to 90°C, breaking it up, and obtaining the modified expanded vermiculite.

[0012] In the preparation method of the modified expanded vermiculite, the particle size range of the expanded vermiculite is 250-325 mesh; the mass ratio of the coating modifier is ethanol: dicetearyl dimer linoleate: PVP K30 = 100: (2-5): (1-3).

[0013] In the above-mentioned coating, the preparation method of the modified halloysite powder comprises the following steps: drying the halloysite powder at a temperature of 100°C to 120°C for 2h to 3h, adding the dried halloysite powder to the intercalation modifier at a ratio of halloysite powder to intercalation modifier = 1: (5 to 8), stirring at a temperature of 35°C to 45°C for 3h to 5h to obtain intercalation-modified halloysite powder, centrifuging, taking the precipitate and drying it at 80°C to 90°C, breaking it up, and obtaining modified halloysite powder.

[0014] In the preparation method of the modified halloysite powder, the particle size range of the halloysite powder is 250-325 mesh; the mass ratio of the intercalation modifier is ethanol: pentaerythritol tetracocoate = 100: (3-8).

[0015] In the above coating, the particle size range of the glass microspheres is 10μm to 250μm, and the wall thickness range is 1μm to 2μm; the diameter range of the ceramic fiber is 3μm to 10μm, and the length is 0.1mm to 0.5mm; the diameter range of the alumina fiber is 3μm to 10μm, and the length is 0.1mm to 0.5mm.

[0016] In the above-mentioned coating, the particle size range of the ammonium polyphosphate is through a 250-325 mesh sieve; the particle size range of the rutile titanium dioxide is through a 250-325 mesh sieve; the particle size range of the dimethyl silylate silica is through a 200-250 mesh sieve; and the particle size range of the nano aerogel is below 100 nm.

[0017] The preparation method of the above-mentioned thermal insulation coating comprises the following steps:

[0018] S1: Add silicone resin by mass into a high-speed disperser, set the speed to 800 r / min to 1000 r / min, then add dispersant and turpentine in sequence, and stir for 10 min to 15 min; then add glass microbeads, ceramic fiber, alumina fiber, modified expanded vermiculite, and modified halloysite powder in sequence, increase the speed to 1200 r / min to 1500 r / min, and stir for 20 min to 30 min to obtain mixture A;

[0019] S2: Transfer mixture A to a sand mill, add grinding media, and grind at 500 rpm to 800 rpm for 1 to 2 hours to improve the uniformity and flatness of the coating; filter and remove the grinding media to obtain ground material B;

[0020] S3: Transfer the ground material B back to the high-speed disperser, and add ammonium polyphosphate, rutile titanium dioxide, dimethyl silylated silica, VP-dimethylaminoethyl methacrylate copolymer, nano aerogel, and fumed silica in sequence at a speed of 600 r / min to 800 r / min, and stir for 15 to 25 minutes; finally, add the leveling agent and defoaming agent, and continue stirring for 5 to 10 minutes to obtain a uniform and stable thermal insulation coating.

[0021] In S2 of the above preparation method, the grinding media are glass beads with a diameter of 2 mm to 3 mm; the grinding media are added in an amount of 30 to 40 parts by mass.

[0022] In the above preparation method, the glass microspheres, ceramic fibers, alumina fibers, modified expanded vermiculite and modified halloysite powder are dried separately to remove moisture before being mixed.

[0023] The present invention provides a thermal insulation coating and a preparation method thereof, which have the following beneficial effects:

[0024] After modification, the expanded vermiculite is coated with a coating modifier consisting of dicetearyl dimer linoleate and PVPK30. This coating modifier improves the compatibility of the expanded vermiculite with other coating ingredients, allowing it to disperse more evenly within the coating system. Unmodified expanded vermiculite inherently possesses certain thermal insulation properties. The improved dispersibility of the modified expanded vermiculite allows for more uniform distribution of these air gaps within the coating, reducing heat conduction pathways and further enhancing the coating's thermal insulation properties. Unmodified expanded vermiculite, an inorganic mineral, exhibits excellent fire resistance. After modification, its inherent fire resistance is retained. Furthermore, its improved dispersibility allows it to more effectively form a barrier layer within the coating in high-temperature environments, preventing flames from penetrating and enhancing the coating's overall fire resistance. The ingredients in the coating modifier form a protective film on the surface of the expanded vermiculite. When exposed to corrosive substances, this protective film comes into contact with the material first, slowing its attack on the expanded vermiculite. This improves the corrosion resistance of the expanded vermiculite in the coating and contributes to the overall corrosion resistance of the coating. Similarly, the protective film formed on the surface of the expanded vermiculite by the coating modifier protects against the effects of climatic factors such as ultraviolet rays, moisture, and temperature fluctuations. For example, the protective film can reduce the damage caused by ultraviolet rays to the expanded vermiculite's structure, allowing it to better maintain its structural integrity in long-term outdoor environments and enhancing the coating's weather resistance.

[0025] Second, modified halloysite powder is modified through intercalation with pentaerythritol tetracocoate. This modification improves the surface properties of the halloysite powder, enhancing its interaction with other coating components and dispersibility, allowing for a more even distribution within the coating system. Unmodified halloysite powder has a low thermal conductivity, which aids in thermal insulation. After modification, due to its more even dispersion within the coating, the halloysite powder's nanotubular structure more effectively absorbs air and forms a more continuous low-heat conduction path, reducing heat transfer and enhancing the coating's thermal insulation properties. The modified halloysite powder is more evenly distributed within the coating, enabling it to better synergize with other fire-retardant ingredients, such as ammonium polyphosphate, to prevent the spread of flames during high temperatures. Furthermore, its inherent structure provides a certain degree of heat insulation at high temperatures, enhancing the overall fire-retardant performance of the coating. The modified structure formed by the intercalation modifier on the surface and within the halloysite powder provides a certain degree of insulation. When the coating comes into contact with corrosive substances, the modified halloysite powder can better resist the intrusion of corrosive substances, reducing damage to its structure, thereby improving the overall corrosion resistance of the coating. The modified halloysite powder's surface structure effectively resists the effects of environmental factors such as ultraviolet rays, moisture, and temperature fluctuations. For example, under ultraviolet radiation, the modified structure can reduce the damage to the halloysite powder's internal structure, making it more stable in long-term outdoor environments, thereby improving the coating's weather resistance.

[0026] 3. Adding silica dimethyl silylate can improve the water resistance and weather resistance of the coating. Silica dimethyl silylate forms a hydrophobic siloxane network structure on the surface of the coating. This layer can prevent the intrusion of moisture and harmful gases, and at the same time resist the influence of ultraviolet rays and other climate factors, thereby improving the weather resistance of the coating.

[0027] Fourth, adding VP-dimethylaminoethyl methacrylate copolymer improves the coating's rheological properties and homogeneity, resulting in better workability. It also helps enhance the coating's adhesion and weather resistance. The copolymer forms a protective film on the coating surface, preventing damage from UV rays and moisture, and improving the coating's weather resistance.

[0028] 5. The present invention designs the parameters of the grinding step according to the characteristics of each component raw material. Grinding improves the uniformity of the coating and improves the particle size, thereby ensuring the thermal insulation, fire resistance, corrosion resistance and weather resistance of the coating to a certain extent.

[0029] 6. Functions of Other Conventional Ingredients: Glass microspheres provide excellent thermal insulation. Ceramic fibers offer excellent thermal insulation and high-temperature resistance, enhancing the coating's structural strength. Alumina fibers improve the coating's high-temperature resistance and thermal insulation. Ammonium polyphosphate is primarily used to enhance the coating's fire resistance. Rutile titanium dioxide improves the coating's hiding power and weather resistance. Nanoaerogel is a highly effective thermal insulation material that significantly enhances the coating's thermal insulation properties.

[0030] In summary, the coating of the present invention contains glass microspheres, ceramic fibers, alumina fibers, ammonium polyphosphate, rutile titanium dioxide, modified expanded vermiculite, modified halloysite powder, dimethyl silylated silica, VP-dimethylaminoethyl methacrylate copolymer, nano-aerogel, and other ingredients, and has excellent thermal insulation effect, improved fire resistance, and long-lasting and stable thermal insulation and fire resistance. The modified expanded vermiculite, modified halloysite powder, dimethyl silylated silica, and VP-dimethylaminoethyl methacrylate copolymer are used in combination to produce a good synergistic effect, which can significantly improve the thermal insulation and heat insulation properties of the coating, block heat conduction, and provide thermal insulation. At the same time, it also has excellent weather resistance, is waterproof, fireproof, and corrosion-resistant, and maintains good performance under complex and changing climatic conditions. DETAILED DESCRIPTION

[0031] The present invention will be further described below with reference to specific implementation cases, but the present invention is not limited to these embodiments.

[0032] Example 1

[0033] A thermal insulation coating comprises the following raw materials in parts by mass: 30 parts of glass microbeads, 16 parts of ceramic fibers, 6 parts of alumina fibers, 5 parts of ammonium polyphosphate, 4 parts of rutile titanium dioxide, 6 parts of modified expanded vermiculite, 8 parts of modified halloysite powder, 3 parts of silica dimethyl silylate, 8 parts of VP-dimethylaminoethyl methacrylate copolymer, 15 parts of nano aerogel, 25 parts of silicone resin, 3.5 parts of dispersant, 0.8 part of leveling agent, 2 parts of defoaming agent, 2 parts of fumed silica, and 12 parts of turpentine.

[0034] The preparation method of the modified expanded vermiculite includes the following steps: preparing a coating modifier according to the mass ratio of ethanol: dicetearyl dimer linoleate: PVP K30 = 100:3:2; passing the expanded vermiculite through a 250-mesh sieve and taking the sieve bottom; drying the sieved expanded vermiculite at 110°C for 2.5 hours, adding the dried expanded vermiculite to the coating modifier according to the ratio of expanded vermiculite: coating modifier = 1:6, stirring at 40°C for 1.5 hours to obtain coated modified expanded vermiculite, centrifuging, taking the precipitate and drying it at 85°C, breaking it up, and obtaining the modified expanded vermiculite.

[0035] In the above-mentioned coating, the preparation method of the modified halloysite powder includes the following steps: preparing an intercalation modifier in a mass ratio of ethanol: pentaerythritol tetracocoate = 100:5; passing the halloysite powder through a 250-mesh sieve and taking the sieve bottom; drying the sieved halloysite powder at 110°C for 2.5 hours, adding the dried halloysite powder to the intercalation modifier in a ratio of halloysite powder: intercalation modifier = 1:6.5, stirring at 40°C for 4 hours to obtain intercalation-modified halloysite powder, centrifuging, taking the precipitate and drying it at 85°C, and breaking it up to obtain modified halloysite powder.

[0036] In the above coating, the particle size range of ammonium polyphosphate is below 250 mesh sieve; the particle size range of the rutile titanium dioxide is below 250 mesh sieve; and the particle size range of the dimethyl silylate silica is below 200 mesh sieve.

[0037] The preparation method of the above-mentioned thermal insulation coating comprises the following steps:

[0038] The glass microspheres, ceramic fibers, alumina fibers, modified expanded vermiculite and modified halloysite powder are dried separately to remove moisture before being mixed.

[0039] S1: Add silicone resin by mass into a high-speed disperser, set the speed to 900 r / min, then add dispersant and turpentine in sequence, and stir for 12 minutes; then add glass microbeads, ceramic fiber, alumina fiber, modified expanded vermiculite, and modified halloysite powder in sequence, increase the speed to 1300 r / min, and stir for 25 minutes; to obtain mixture A.

[0040] S2: Transfer mixture A to a sand mill, add 35 parts by mass of grinding media, i.e., glass beads with a diameter of 2 mm, and grind at 600 r / min for 1.5 h to improve the uniformity and flatness of the coating; filter and remove the grinding media to obtain ground material B.

[0041] S3: Transfer the ground material B back to the high-speed disperser, and add ammonium polyphosphate, rutile titanium dioxide, dimethyl silylated silica, VP-dimethylaminoethyl methacrylate copolymer, nano aerogel, and fumed silica in sequence at a speed of 700 r / min, and stir for 20 minutes; finally, add the leveling agent and defoaming agent, and continue stirring for 8 minutes to obtain a uniform and stable thermal insulation coating.

[0042] Example 2

[0043] A thermal insulation coating comprises the following raw materials in parts by mass: 25 parts of glass microbeads, 12 parts of ceramic fibers, 4 parts of alumina fibers, 4 parts of ammonium polyphosphate, 3 parts of rutile titanium dioxide, 5 parts of modified expanded vermiculite, 5 parts of modified halloysite powder, 2 parts of silica dimethyl silylate, 6 parts of VP-dimethylaminoethyl methacrylate copolymer, 12 parts of nano aerogel, 20 parts of silicone resin, 3 parts of dispersant, 0.5 parts of leveling agent, 1 part of defoamer, 1 part of fumed silica, and 10 parts of turpentine.

[0044] The preparation method of the modified expanded vermiculite comprises the following steps: preparing a coating modifier according to a mass ratio of ethanol: dicetearyl dimer linoleate: PVP K30 = 100:2:1; passing the expanded vermiculite through a 250-mesh sieve and taking the sieve bottom; drying the sieved expanded vermiculite at 100° C. for 2 hours, adding the dried expanded vermiculite to the coating modifier at a ratio of expanded vermiculite: coating modifier = 1:5, stirring at 35° C. for 1 hour to obtain coated modified expanded vermiculite, centrifuging, taking the precipitate and drying it at 80° C., and breaking it up to obtain the modified expanded vermiculite.

[0045] In the above-mentioned coating, the preparation method of the modified halloysite powder includes the following steps: preparing an intercalation modifier in a mass ratio of ethanol: pentaerythritol tetracocoate = 100:3; passing the halloysite powder through a 250-mesh sieve and taking the sieve bottom; drying the sieved halloysite powder at 100° C. for 2 hours, adding the dried halloysite powder to the intercalation modifier in a ratio of halloysite powder: intercalation modifier = 1:5, stirring at 35° C. for 3 hours to obtain intercalation-modified halloysite powder, centrifuging, taking the precipitate and drying it at 80° C., and breaking it up to obtain modified halloysite powder.

[0046] In the above coating, the particle size range of ammonium polyphosphate is below 250 mesh sieve; the particle size range of the rutile titanium dioxide is below 250 mesh sieve; and the particle size range of the dimethyl silylate silica is below 200 mesh sieve.

[0047] The preparation method of the above-mentioned thermal insulation coating comprises the following steps:

[0048] The glass microspheres, ceramic fibers, alumina fibers, modified expanded vermiculite and modified halloysite powder are dried separately to remove moisture before being mixed.

[0049] S1: Add silicone resin by mass into a high-speed disperser, set the speed to 800 r / min, then add dispersant and turpentine in sequence, and stir for 10 minutes; then add glass microbeads, ceramic fiber, alumina fiber, modified expanded vermiculite, and modified halloysite powder in sequence, increase the speed to 1200 r / min, and stir for 20 minutes; to obtain mixture A.

[0050] S2: Transfer mixture A to a sand mill, add 30 parts by mass of grinding media, i.e., glass beads with a diameter of 2 mm, and grind at 500 r / min for 1 hour to improve the uniformity and flatness of the coating; filter and remove the grinding media to obtain ground material B.

[0051] S3: Transfer the ground material B back to the high-speed disperser, and add ammonium polyphosphate, rutile titanium dioxide, dimethyl silylated silica, VP-dimethylaminoethyl methacrylate copolymer, nano aerogel, and fumed silica in sequence at a speed of 600 r / min, and stir for 15 minutes; finally, add the leveling agent and defoaming agent, and continue stirring for 5 minutes to obtain a uniform and stable thermal insulation coating.

[0052] Example 3

[0053] A thermal insulation coating comprises the following raw materials in parts by mass: 25 parts of glass microbeads, 20 parts of ceramic fibers, 4 parts of alumina fibers, 7 parts of ammonium polyphosphate, 3 parts of rutile titanium dioxide, 8 parts of modified expanded vermiculite, 5 parts of modified halloysite powder, 5 parts of dimethyl silylated silica, 6 parts of VP-dimethylaminoethyl methacrylate copolymer, 18 parts of nano aerogel, 20 parts of silicone resin, 4 parts of dispersant, 0.5 parts of leveling agent, 3 parts of defoaming agent, 1 part of fumed silica, and 13 parts of turpentine.

[0054] The preparation method of the modified expanded vermiculite includes the following steps: preparing a coating modifier according to the mass ratio of ethanol: dicetearyl dimer linoleate: PVP K30 = 100:2:3; passing the expanded vermiculite through a 250-mesh sieve and taking the sieve bottom; drying the sieved expanded vermiculite at 120° C. for 2 hours, adding the dried expanded vermiculite to the coating modifier according to the ratio of expanded vermiculite: coating modifier = 1:8, stirring at 35° C. for 2 hours to obtain coated modified expanded vermiculite, centrifuging, taking the precipitate and drying it at 80° C., and breaking it up to obtain the modified expanded vermiculite.

[0055] In the above-mentioned coating, the preparation method of the modified halloysite powder comprises the following steps: preparing an intercalation modifier in a mass ratio of ethanol to pentaerythritol tetracocoate = 100:8; passing the halloysite powder through a 250-mesh sieve and taking the sieve bottom; drying the sieved halloysite powder at 120° C. for 2 h, adding the dried halloysite powder to the intercalation modifier in a ratio of halloysite powder to intercalation modifier = 1:8, stirring at 35° C. for 5 h to obtain intercalation-modified halloysite powder, centrifuging, taking the precipitate and drying it at 80° C., and breaking it up to obtain modified halloysite powder.

[0056] In the above coating, the particle size range of ammonium polyphosphate is below 325 mesh sieve; the particle size range of the rutile titanium dioxide is below 250 mesh sieve; and the particle size range of the dimethyl silylate silica is below 250 mesh sieve.

[0057] The preparation method of the above-mentioned thermal insulation coating comprises the following steps:

[0058] The glass microspheres, ceramic fibers, alumina fibers, modified expanded vermiculite and modified halloysite powder are dried separately to remove moisture before being mixed.

[0059] S1: Add silicone resin by mass into a high-speed disperser, set the speed to 800 r / min, then add dispersant and turpentine in sequence, and stir for 15 minutes; then add glass microbeads, ceramic fiber, alumina fiber, modified expanded vermiculite, and modified halloysite powder in sequence, increase the speed to 1200 r / min, and stir for 30 minutes; to obtain mixture A.

[0060] S2: Transfer mixture A to a sand mill, add 30 parts by mass of grinding media, i.e., glass beads with a diameter of 3 mm, and grind at 500 r / min for 2 h to improve the uniformity and flatness of the coating; filter and remove the grinding media to obtain ground material B.

[0061] S3: Transfer the ground material B back to the high-speed disperser, and add ammonium polyphosphate, rutile titanium dioxide, dimethyl silylated silica, VP-dimethylaminoethyl methacrylate copolymer, nano aerogel, and fumed silica in sequence at a speed of 600 r / min, and stir for 25 minutes; finally, add the leveling agent and defoamer, and continue stirring for 5 minutes to obtain a uniform and stable thermal insulation coating.

[0062] Example 4

[0063] A thermal insulation coating comprises the following raw materials in parts by mass: 35 parts of glass microbeads, 20 parts of ceramic fibers, 8 parts of alumina fibers, 7 parts of ammonium polyphosphate, 6 parts of rutile titanium dioxide, 8 parts of modified expanded vermiculite, 10 parts of modified halloysite powder, 5 parts of silica dimethyl silylate, 10 parts of VP-dimethylaminoethyl methacrylate copolymer, 18 parts of nano aerogel, 30 parts of silicone resin, 4 parts of dispersant, 1 part of leveling agent, 3 parts of defoaming agent, 3 parts of fumed silica, and 15 parts of turpentine.

[0064] The preparation method of the modified expanded vermiculite comprises the following steps: preparing a coating modifier in a mass ratio of ethanol: dicetearyl dimer linoleate: PVP K30 = 100:5:3; passing the expanded vermiculite through a 325-mesh sieve and taking the sieve bottom; drying the sieved expanded vermiculite at 120° C. for 3 hours, adding the dried expanded vermiculite to the coating modifier in a ratio of expanded vermiculite: coating modifier = 1:8, stirring at 45° C. for 2 hours to obtain coated modified expanded vermiculite, centrifuging, taking the precipitate and drying it at 90° C., and breaking it up to obtain the modified expanded vermiculite.

[0065] In the above-mentioned coating, the preparation method of the modified halloysite powder includes the following steps: preparing an intercalation modifier in a mass ratio of ethanol: pentaerythritol tetracocoate = 100:8; passing the halloysite powder through a 325-mesh sieve and taking the sieve bottom; drying the sieved halloysite powder at 120°C for 3 hours, adding the dried halloysite powder to the intercalation modifier in a ratio of halloysite powder: intercalation modifier = 1:8, stirring at 45°C for 5 hours to obtain intercalation-modified halloysite powder, centrifuging, taking the precipitate and drying it at 90°C, and breaking it up to obtain modified halloysite powder.

[0066] In the above coating, the particle size range of ammonium polyphosphate is below 325 mesh sieve; the particle size range of the rutile titanium dioxide is below 325 mesh sieve; and the particle size range of the dimethyl silylate silica is below 250 mesh sieve.

[0067] The preparation method of the above-mentioned thermal insulation coating comprises the following steps:

[0068] The glass microspheres, ceramic fibers, alumina fibers, modified expanded vermiculite and modified halloysite powder are dried separately to remove moisture before being mixed.

[0069] S1: Add silicone resin by mass into a high-speed disperser, set the speed to 1000 r / min, then add dispersant and turpentine in sequence, and stir for 15 minutes; then add glass microbeads, ceramic fiber, alumina fiber, modified expanded vermiculite, and modified halloysite powder in sequence, increase the speed to 1500 r / min, and stir for 30 minutes; to obtain mixture A.

[0070] S2: Transfer mixture A to a sand mill, add 40 parts by mass of grinding media, i.e., glass beads with a diameter of 3 mm, and grind at 800 r / min for 2 h to improve the uniformity and flatness of the coating; filter and remove the grinding media to obtain ground material B.

[0071] S3: Transfer the ground material B back to the high-speed disperser, and add ammonium polyphosphate, rutile titanium dioxide, dimethyl silylate silica, VP-dimethylaminoethyl methacrylate copolymer, nano aerogel, and fumed silica in sequence at a speed of 800 r / min, and stir for 25 minutes; finally, add the leveling agent and defoamer, and continue stirring for 10 minutes to obtain a uniform and stable thermal insulation coating.

[0072] Example 5

[0073] A thermal insulation coating comprises the following raw materials in parts by mass: 35 parts of glass microbeads, 12 parts of ceramic fibers, 8 parts of alumina fibers, 4 parts of ammonium polyphosphate, 6 parts of rutile titanium dioxide, 5 parts of modified expanded vermiculite, 10 parts of modified halloysite powder, 2 parts of silica dimethyl silylate, 10 parts of VP-dimethylaminoethyl methacrylate copolymer, 12 parts of nano aerogel, 30 parts of silicone resin, 3 parts of dispersant, 1 part of leveling agent, 1 part of defoamer, 3 parts of fumed silica, and 12 parts of turpentine.

[0074] The preparation method of the modified expanded vermiculite includes the following steps: preparing a coating modifier according to the mass ratio of ethanol: dicetearyl dimer linoleate: PVP K30 = 100:5:1; passing the expanded vermiculite through a 325-mesh sieve and taking the sieve bottom; drying the sieved expanded vermiculite at 100°C for 3 hours, adding the dried expanded vermiculite to the coating modifier at a ratio of expanded vermiculite: coating modifier = 1:5, stirring at 45°C for 1 hour to obtain coated modified expanded vermiculite, centrifuging, taking the precipitate and drying it at 90°C, breaking it up, and obtaining the modified expanded vermiculite.

[0075] In the above-mentioned coating, the preparation method of the modified halloysite powder includes the following steps: preparing an intercalation modifier according to a mass ratio of ethanol: pentaerythritol tetracocoate = 100:3; passing the halloysite powder through a 325-mesh sieve and taking the sieve bottom; drying the sieved halloysite powder at 100°C for 3 hours, adding the dried halloysite powder to the intercalation modifier at a ratio of halloysite powder: intercalation modifier = 1:5, stirring at 45°C for 3 hours to obtain intercalation-modified halloysite powder, centrifuging, taking the precipitate and drying it at 90°C, and breaking it up to obtain modified halloysite powder.

[0076] In the above coating, the particle size range of ammonium polyphosphate is below 250 mesh sieve; the particle size range of the rutile titanium dioxide is below 325 mesh sieve; and the particle size range of the dimethyl silylate silica is below 200 mesh sieve.

[0077] The preparation method of the above-mentioned thermal insulation coating comprises the following steps:

[0078] The glass microspheres, ceramic fibers, alumina fibers, modified expanded vermiculite and modified halloysite powder are dried separately to remove moisture before being mixed.

[0079] S1: Add silicone resin by mass into a high-speed disperser, set the speed to 1000 r / min, then add dispersant and turpentine in sequence, and stir for 10 minutes; then add glass microbeads, ceramic fiber, alumina fiber, modified expanded vermiculite, and modified halloysite powder in sequence, increase the speed to 1500 r / min, and stir for 20 minutes; to obtain mixture A.

[0080] S2: The mixture A is transferred to a sand mill, 40 parts of grinding medium, i.e. glass beads with a diameter of 2 mm, are added, and grinding is carried out at 800 r / min for 1 h to improve the uniformity and flatness of the coating; the grinding medium is removed by filtration to obtain a ground material B.

[0081] S3: The ground material B is transferred back to the high-speed dispersion machine, and ammonium polyphosphate, rutile titanium dioxide, dimethylsilylated silica, VP-dimethylaminoethyl methacrylate copolymer, nano-aerogel, and fumed silica are sequentially added at a rotation speed of 800 r / min, and stirring is carried out for 15 min; finally, a leveling agent and a defoaming agent are added, and stirring is continued for 10 min to obtain a uniform and stable thermal insulation coating.

[0082] In the above examples: the particle size of the glass microbeads ranges from 10 μm to 250 μm, and the wall thickness ranges from 1 μm to 2 μm; the diameter of the ceramic fiber ranges from 3 μm to 10 μm, and the length ranges from 0.1 mm to 0.5 mm; the diameter of the alumina fiber ranges from 3 μm to 10 μm, and the length ranges from 0.1 mm to 0.5 mm; the particle size of the nano-aerogel is less than 100 nm. The dimethylsilylated silica is from Hubei Shixing Chemical Co., Ltd.; the fumed silica is Wacker HDK H20BET200 from Shanghai Yunhe Material Technology Co., Ltd.; the nano-aerogel is from Jin Yuan Mining Processing Factory in Lingshou County; the VP-dimethylaminoethyl methacrylate copolymer is from Shanghai Yuyu New Material Technology Co., Ltd.; the silicone resin is a liquid resin, which is Dow Corning RSN-0805 resin from Guangzhou Rongda Chemical Co., Ltd.; the dispersing agent is sodium hexametaphosphate; the leveling agent is an acrylate leveling agent, model LS3022, from Kunshan Luolisi High Polymer Material Co., Ltd.; the defoaming agent is a polyether-modified silicone defoaming agent, model W-650, from Guangzhou Weikai New Material Co., Ltd.; the turpentine is from Jinan Tian Tai Chemical Co., Ltd.; the dicetylstearyl alcohol dimer dilinoleate is from Jin Jile (Hunan) Chemical Co., Ltd.; PVP K30 is polyvinylpyrrolidone K30 from Shanghai Changyu New Chemical Material Co., Ltd.; and pentaerythritol tetra-cocoate is from Shanghai Donghui Chemical Technology Co., Ltd.

[0083] Comparative Example 1

[0084] In the coating, the expanded vermiculite is not modified, and the modified expanded vermiculite is directly replaced by expanded vermiculite; other parameters and methods are the same as in Example 1.

[0085] Comparative Example 2

[0086] In the coating, the halloysite powder is not modified, and the modified halloysite powder is directly replaced by halloysite powder; other parameters and methods are the same as in Example 1.

[0087] Comparative Example 3

[0088] In the coating, the expanded vermiculite was not modified, and the modified expanded vermiculite was directly replaced by the expanded vermiculite; the halloysite powder was not modified, and the modified halloysite powder was directly replaced by the halloysite powder; other parameters and methods were the same as in Example 1.

[0089] Comparative Example 4

[0090] In the coating, modified expanded vermiculite and modified halloysite powder were not added, and the mass fractions of modified expanded vermiculite and modified halloysite powder were replaced by glass microspheres; other parameters and methods were the same as in Example 1.

[0091] Comparative Example 5

[0092] No silica dimethyl silylate was added to the coating; other parameters and methods were the same as in Example 1.

[0093] Comparative Example 6

[0094] No VP-dimethylaminoethyl methacrylate copolymer was added to the coating; other parameters and methods were the same as in Example 1.

[0095] Comparative Example 7

[0096] In the coating, expanded vermiculite is not modified, and the modified expanded vermiculite is directly replaced by expanded vermiculite; halloysite powder is not modified, and the modified halloysite powder is directly replaced by halloysite powder; no silica dimethyl silylate is added; no VP-dimethylaminoethyl methacrylate copolymer is added; other parameters and methods are the same as in Example 1.

[0097] Comparative Example 8

[0098] In the preparation method, S2 is omitted and a sand mill is not used for grinding; other parameters and methods are the same as in Example 1.

[0099] The coatings prepared in the above embodiments and comparative examples were tested for their performance.

[0100] 1. Sample:

[0101] Substrate: 4 mm thick low-carbon steel plate, the thermal conductivity of the bare steel plate is 45 W / (m·K). After sandblasting, the steel plate is scraped with the coatings of each embodiment and each comparative example, and the coating thickness is 1 mm.

[0102] 2. Project testing:

[0103] (1) Adhesion test: The test was conducted according to GB / T 9286 "Cross-cut test for paint and varnish films". A 10 × 10 2 mm × 2 mm grid was drawn on the surface of the sample using a cross-cut knife. After the grid was drawn, adhesive tape was tightly applied to the small grid to be tested. The tape was rubbed vigorously with an eraser and then quickly torn off in a vertical direction. The adhesion was graded based on the degree of coating shedding. The test results are shown in Table 1 below.

[0104] (2) Water resistance test: The test was conducted according to GB / T 1733 "Determination of water resistance of paint films". The sample was placed in distilled water, with 2 / 3 of the test panel length immersed in water. The water temperature was adjusted to 25°C. After 240 hours, the test panel was observed for loss of gloss, discoloration, blistering, wrinkling, shedding, rusting, etc. The test results are shown in Table 1 below.

[0105] Water resistance evaluation level: Level 1: The coating is intact and maintains its original state, with no loss of gloss, discoloration, blistering, wrinkling, peeling, rust, etc.; Level 2: The coating surface has slight changes, with a lighter degree of gloss loss, slightly lighter color, etc., but it does not affect the overall performance of the coating; Level 3: The coating surface has obvious changes, with a heavier degree of gloss loss, discoloration, blistering, wrinkling, peeling, rust, etc., but it has not reached the level of serious damage; Unqualified: The coating has serious bubbles, peeling, rust, etc., and the water resistance is poor and cannot meet the use requirements.

[0106] (3) Thermal conductivity test: The test was conducted in accordance with GB / T 10295 "Determination of Steady-State Thermal Resistance and Related Properties of Insulating Materials - Heat Flow Meter Method" using a WPY heat flow meter thermal conductivity tester DX-8377. The hot surface temperature was controlled at 70°C and the cold surface temperature was controlled at room temperature. The device was turned on and the thermal conductivity of the sample was automatically measured using a computer. The test results are shown in Table 1 below.

[0107] (4) Combustion Growth Rate Index Test: The test was conducted using an FTT0007 cone calorimeter. A 3mm thick layer of thermal insulation coating was filled into a sample box, and the sides and bottom were wrapped with tin foil. After preheating the radiation cone, the test was performed to determine the combustion growth rate index of the coating. The test results are shown in Table 1 below.

[0108] (5) Salt spray resistance test: According to the test method of GB / T 1771 "Determination of resistance of paints and varnishes to neutral salt spray", the coated sample is placed on the sample rack of the salt spray test chamber and the neutral salt spray test (sodium chloride solution concentration of 5%, test temperature of 35 ° C, salt spray deposition rate of 1.2 ml / 80 cm) is used. 2 / h), and after the spraying continued for 500h, the state of the coating surface was observed. The test results are shown in Table 1 below.

[0109] Salt spray resistance evaluation level, level 10: no defect area of ​​the coating, no change in the appearance of the sample surface; level 9: the coating defect area accounts for less than 0.1%, and the sample surface has slight to moderate discoloration; level 8: the coating defect area accounts for greater than or equal to 0.1% and less than 0.25%, and the sample surface has severe discoloration or very slight corrosion products; level 7: the coating defect area accounts for greater than or equal to 0.25% and less than 0.5%, and the sample surface has severe gloss loss or very slight corrosion products; level 6: the coating defect area accounts for greater than or equal to 0.5% and less than 1.0%, and the sample surface has severe gloss loss or a thin layer of corrosion products or pitting on the local surface of the sample; level 5: the coating defect area accounts for greater than or equal to 1 .0% and less than 2.5%, there are corrosion products or pitting on the surface of the specimen, and one of them is distributed on the entire surface of the specimen; Level 4: The coating defect area accounts for greater than or equal to 2.5% and less than 5%, and there is a thick corrosion product layer or pitting on the surface of the specimen; Level 3: The coating defect area accounts for greater than or equal to 5% and less than 10%, and there is a very thick corrosion product layer or pitting on the surface of the specimen, and there are deep pitting; Level 2: The coating defect area accounts for greater than or equal to 10% and less than 25%, and the specimen has base metal corrosion; Level 1: The coating defect area accounts for greater than or equal to 25% and less than 50%, which is a serious corrosion phenomenon; Level 0: The coating defect area accounts for greater than 50%, which is a very serious corrosion phenomenon.

[0110] (6) Xenon lamp accelerated aging test was carried out according to GB / T 1865 “Paints and varnishes exposed to artificial weathering and artificial radiation by filtered xenon arc radiation”, with a light intensity of 0.65W / m 2 nm; during daytime, when sunlight is strong, the temperature was set to 60°C and the humidity to 40%, simulating a high-temperature environment under direct sunlight; at night (when sunlight is off), the temperature was lowered to 30°C and the humidity to 60%, creating a diurnal temperature difference; spraying was conducted every 6 hours, with each spraying lasting 15 minutes; the hardness of the spraying water was controlled at 80 mg / L (calculated as calcium carbonate), and 0.2% sodium chloride was added to the spraying water to adjust the pH to 5.0. The test lasted 1200 hours, after which the coating's water resistance, thermal conductivity, and combustion growth rate index were measured. The test results are shown in Table 1 below.

[0111] Table 1 Coating performance test results

[0112]

[0113] From the above experimental results, it can be seen that the thermal insulation coatings prepared by examples 1 to 5 have good thermal insulation performance, can block heat conduction, and play a role in thermal insulation, and also have excellent weather resistance, can prevent water, fire, corrosion, and maintain good performance state under complex and changeable climate conditions. From the results of comparative example 1, it can be seen that after modification of the expanded vermiculite, the surface of the modified modifier can improve the compatibility of the expanded vermiculite with other components in the coating, so that it is more uniformly dispersed in the coating system, thereby achieving better thermal insulation, fire resistance, corrosion resistance and weather resistance; From the results of comparative example 2, it can be seen that after modification of the halloysite powder, the surface properties are improved, and the interaction with other components in the coating is enhanced, thereby achieving better thermal insulation, fire resistance, corrosion resistance and weather resistance; From the results of comparative example 3, it can be seen that the expanded vermiculite and halloysite powder are not modified, and the thermal insulation, fire resistance, corrosion resistance and weather resistance of the coating are all decreased; From the results of comparative example 4, it can be seen that the modified expanded vermiculite and modified halloysite powder are not added in the coating, which affects the thermal insulation performance of the coating, and at the same time, the waterproof, fireproof, corrosion resistant and weather resistant properties of the coating are also weakened; From the results of comparative example 5, it can be seen that dimethylsilylated silica can form a layer of hydrophobic siloxane network structure on the surface of the coating, preventing the intrusion of water and harmful gases, thereby improving the water resistance, weather resistance and other properties of the coating; From the results of comparative example 6, it can be seen that VP-methyl methacrylate dimethylaminoethyl copolymer can form a protective film on the surface of the coating, and improve the compatibility of each component, thereby improving the performance of the coating; From the results of comparative example 7, it can be seen that the expanded vermiculite and halloysite powder in the coating are not modified, and at the same time, dimethylsilylated silica and VP-methyl methacrylate dimethylaminoethyl copolymer are not added, and the thermal insulation, fire resistance, corrosion resistance and weather resistance of the coating are significantly weakened; From the results of comparative example 8, it can be seen that the grinding step of mixture A is removed in the preparation method, the uniformity of the coating is poor, and the thermal insulation, fire resistance, corrosion resistance and weather resistance are weakened.

Claims

1. A thermal insulation coating, characterized in that: The coating comprises the following raw materials in parts by mass: 25 to 35 parts of glass microbeads, 12 to 20 parts of ceramic fibers, 4 to 8 parts of alumina fibers, 4 to 7 parts of ammonium polyphosphate, 3 to 6 parts of rutile titanium dioxide, 5 to 8 parts of modified expanded vermiculite, 5 to 10 parts of modified halloysite powder, 2 to 5 parts of silica dimethyl silylate, 6 to 10 parts of VP-dimethylaminoethyl methacrylate copolymer, 12 to 18 parts of nano aerogel, 20 to 30 parts of silicone resin, 3 to 4 parts of dispersant, 0.5 to 1 part of leveling agent, 1 to 3 parts of defoaming agent, 1 to 3 parts of fumed silica, and 10 to 15 parts of turpentine. The preparation method of the modified expanded vermiculite comprises the following steps: drying the expanded vermiculite at a temperature of 100° C. to 120° C. for 2 h to 3 h, adding the dried expanded vermiculite to the coating modifier at a ratio of expanded vermiculite to coating modifier of 1:(5-8), stirring at a temperature of 35° C. to 45° C. for 1 h to 2 h to obtain coated modified expanded vermiculite, centrifuging, drying the precipitate at 80° C. to 90° C., and breaking it up to obtain modified expanded vermiculite; the mass ratio of the coating modifier is ethanol: dicetearyl dimer linoleate: PVP K30 = 100:(2-5):(1-3); The preparation method of the modified halloysite powder comprises the following steps: drying the halloysite powder at a temperature of 100°C to 120°C for 2h to 3h, adding the dried halloysite powder to the intercalation modifier at a ratio of halloysite powder to intercalation modifier of 1:(5-8), stirring at a temperature of 35°C to 45°C for 3h to 5h to obtain intercalation-modified halloysite powder, centrifuging, drying the precipitate at 80°C to 90°C, and breaking it up to obtain the modified halloysite powder; the mass ratio of the intercalation modifier is ethanol to pentaerythritol tetracocoate of 100:(3-8).

2. A thermal insulation coating according to claim 1, characterized in that: The particle size range of the expanded vermiculite is 250-325 mesh.

3. The thermal insulation coating according to claim 1, characterized in that: The particle size of the halloysite powder ranges from 250 mesh to 325 mesh.

4. The thermal insulation coating according to claim 1, characterized in that: The particle size of the glass microbeads ranges from 10 μm to 250 μm, and the wall thickness ranges from 1 μm to 2 μm; the diameter of the ceramic fibers ranges from 3 μm to 10 μm, and the length ranges from 0.1 mm to 0.5 mm; the diameter of the alumina fibers ranges from 3 μm to 10 μm, and the length ranges from 0.1 mm to 0.5 mm.

5. The thermal insulation coating according to claim 1, characterized in that: The particle size range of the ammonium polyphosphate is 250-325 mesh; the particle size range of the rutile titanium dioxide is 250-325 mesh; the particle size range of the dimethyl silylate silica is 200-250 mesh; the particle size range of the nano aerogel is below 100 nm.

6. A method for preparing a thermal insulation coating, for preparing the thermal insulation coating according to claim 1, characterized in that: The preparation method comprises the following steps: S1: Add silicone resin by mass into a high-speed disperser, set the speed to 800 r / min to 1000 r / min, then add dispersant and turpentine in sequence, and stir for 10 min to 15 min; then add glass microbeads, ceramic fiber, alumina fiber, modified expanded vermiculite, and modified halloysite powder in sequence, increase the speed to 1200 r / min to 1500 r / min, and stir for 20 min to 30 min to obtain mixture A; S2: Transfer mixture A to a sand mill, add grinding media, and grind at 500 rpm to 800 rpm for 1 h to 2 h to improve the uniformity and flatness of the coating; Filter and remove the grinding medium to obtain grinding material B; S3: Transfer the ground material B back to the high-speed disperser, and add ammonium polyphosphate, rutile titanium dioxide, dimethyl silylated silica, VP-dimethylaminoethyl methacrylate copolymer, nano aerogel, and fumed silica in sequence at a speed of 600 r / min to 800 r / min, and stir for 15 to 25 minutes; finally, add the leveling agent and defoaming agent, and continue stirring for 5 to 10 minutes to obtain a uniform and stable thermal insulation coating.

7. The method for preparing a thermal insulation coating according to claim 6, characterized in that: In S2, the grinding media are glass beads with a diameter of 2 mm to 3 mm; the grinding media are added in an amount of 30 to 40 parts by mass.

8. The method for preparing a thermal insulation coating according to claim 6, characterized in that: The glass microbeads, ceramic fibers, alumina fibers, modified expanded vermiculite and modified halloysite powder are dried separately to remove moisture before being mixed.

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