High temperature resistant lightweight coating and its preparation method and application

Abstract

The present invention provides a high-temperature resistant lightweight coating, which is composed of, in addition to polyvinyl pyrrolidone, sulfobetaine, and water-based polyurethane, magnesium aluminum hydrotalcite, diatomaceous earth, nano titanium dioxide, nano iron oxide, nano copper oxide, nano aluminum oxide, nano silicon dioxide, nano zinc borate, nano tungsten trioxide, aluminum silicate fiber, hollow silicon dioxide microspheres, nano lithium silicate, nano lanthanum oxide, nano modified zirconium oxide fiber, ethylene glycol, and vinyl trimethoxysilane. The high-temperature resistant lightweight coating provided by the present invention has excellent thermal insulation effect. When the obtained coating thickness is 0.05 mm, the temperature of the coating substrate can be kept below 50°C for more than 15 minutes at 1300°C. It also has excellent thermal shock resistance and can withstand 50 1300°C water temperature cycles without cracking. In addition, it can also have an anti-fouling effect on the ashes of burning wood.

Description

Technical Field

[0001] This patent belongs to the field of new material technology, involving coating material preparation technology, and particularly relates to lightweight coating materials that are resistant to high temperatures and thermal shock. Background Art

[0002] In recent years, the need for specialized equipment to adapt to increasingly complex operating conditions has led to an increasing demand for high-temperature-resistant materials. High-temperature-resistant coatings for drones are a key research and development area. Furthermore, due to the need for extended flight time, coatings for drones often require lightweighting. Therefore, the high-temperature resistance and lightweight nature of drone coatings are top priorities in research and development.

[0003] Two years ago, the high temperature resistance of coating materials in this field was poor, and the insulation temperature was generally only a few hundred degrees Celsius. For example, Shen Hang wrote in his paper "Application of Water-Based Base Materials in the Construction of Ultra-Thin Steel Structure Fireproof and Anti-Corrosion Coating Systems" [1] A water-based base material with high fire resistance and corrosion resistance was reported in the paper. The coating prepared with it can make the substrate heat up to 360℃ after 8 minutes under flame, which greatly delays the heating time compared with the uncoated coating. However, the impact of high temperature environment on battery performance appears above 50℃. When the ambient temperature exceeds 50℃, the battery temperature cannot be well controlled. [2] . It can be seen that the coating used two years ago is not suitable for coating drones containing batteries. This aspect has been described in detail in the background technology and cited documents of the two invention patents CN115521676B and ZLCN115521695B applied for by the inventor team of this patent on May 18, 2022, and will not be repeated in this patent.

[0004] Invention patents CN115521676B and ZLCN115521695B significantly improve the high-temperature resistance of drone coatings to a good level of working at 1300°C for 15 minutes with the temperature on the back of the coating not exceeding 50°C. After the above two invention patents, some coatings that can withstand 1300°C have also been developed in this field. For example, the invention patent CN115433479B applied for on October 18, 2022, the resulting phosphate gum-based flame retardant and thermal insulation coating can keep the temperature on the back of the coating at a low level under a flame spray of 1200-1300°C, but after 800 seconds (i.e. 15 minutes), the temperature on the back of the coating has reached about 200°C, which is obviously not suitable for coating on drones with batteries inside the body. However, this patent has the advantage of preheating expansion and is suitable for high-temperature working conditions for collision prevention. In other words, there are still few coating materials that can be used for drone coating, can withstand high temperatures of 1300°C and ensure that drones can work for a long time.

[0005] Following the invention patents CN115521676B and ZLCN115521695B, the inventors discovered that the coatings obtained from these two patents lacked thermal shock resistance. Specifically, when the coating is exposed to a sudden drop in temperature after being exposed to high temperatures, it is prone to premature cracking and flaking, resulting in poor thermal shock resistance. Consequently, when drones are deployed near fires or fighting fires in the rain, they are prone to thermal shock and cracking due to water contact, causing the drone's internal temperature to rise instantly, rendering it inoperable.

[0006] Thermal shock problems are prone to occur in high-temperature resistant materials. For example, 6-8wt.% Y203-Zr02 (8YSZ) material is a commonly used high-temperature resistant coating, but it has poor thermal shock resistance and the coating service life is often short. Generally speaking, thermal shock resistance can be improved by adjusting the critical particle size and shape of the raw material particles, but this method has little effect. In addition, the introduction of fibers can increase the energy required for the material to break and exhibit significant nonlinear characteristics, thereby improving thermal shock resistance. However, CN 115521695 B, which uses nano-aluminum silicate fibers as raw materials, also failed to solve the problem of thermal shock resistance.

[0007] Therefore, how to prepare a coating that can operate in a temperature environment of 1300°C and ensure that the drone components in the coating can operate in a working environment at a temperature not higher than 50°C for a long time, while also making the resulting coating have good thermal shock resistance, is a problem that needs to be further solved in this field.

[0008] In addition, in a fire scene, not only can flying debris from the explosion easily scratch the drone coating, but the ash produced after the combustion can also easily fall or adhere to the fuselage. Therefore, the high-temperature resistant coating on the drone needs to have certain anti-fouling properties in addition to being scratch-resistant.

[0009] [1] Shen Hang. Application of water-based binder in the construction of ultra-thin steel structure fire retardant and anti-corrosion coating system[J]. Coatings Industry, 2018, 48(04): 35-42.

[0010] [2] Li Niansi, Liu Xiaoyong, Li Liang, et al. Research on the adaptability of UAV lithium-ion batteries to high and low temperature extreme environments [J]. China Journal of Safety Science, 30(8):6. Summary of the Invention

[0011] In response to the shortcomings of the prior art, the purpose of the present invention is to provide a lightweight coating material that is resistant to high temperatures and thermal shock. At a coating thickness of 0.05 mm, the coating can not only ensure that the temperature of the back of the coating does not exceed 50°C within 15 minutes at a temperature of 1300°C; it also has excellent thermal shock resistance and can withstand 50 1300°C-water temperature cycles without cracking; in addition, it can also have an anti-fouling effect on the ashes of burning wood.

[0012] Therefore, unless otherwise specified, the "high-temperature resistant lightweight coating" referred to in the present invention should be understood as a coating material that can meet the above requirements.

[0013] In order to achieve the above object, the technical solution provided by the present invention is as follows:

[0014] A high-temperature resistant lightweight coating, comprising the following components A, B, and C;

[0015] The ingredients of component A include polyvinyl pyrrolidone, sulfobetaine and water-based polyurethane;

[0016] The ingredients in component B, calculated by weight, include 5-7 parts of magnesium aluminum hydrotalcite, 2-3 parts of diatomaceous earth, 5-7 parts of nano titanium dioxide, 8-10 parts of nano iron oxide, 5-8 parts of nano copper oxide, 12-15 parts of nano aluminum oxide, 8-10 parts of nano silicon dioxide, 5-8 parts of nano zinc borate, 3-5 parts of nano tungsten trioxide, 5-8 parts of nano aluminum silicate fiber, 22-25 parts of hollow silicon dioxide microspheres, 3-5 parts of nano lithium silicate, 5-8 parts of nano lanthanum oxide, and 12-15 parts of nano modified zirconia fiber;

[0017] The components in component C are composed of ethylene glycol and vinyltrimethoxysilane in a weight ratio of 3:4;

[0018] The weight ratio of component A, component B and component C is (10-12):10:(2-3);

[0019] The nano-modified zirconia fiber is obtained by the following preparation method:

[0020] (1) placing the zirconium oxide fiber in hydrochloric acid for heating treatment, washing and drying to obtain the treated zirconium oxide fiber;

[0021] (2) Using crystalline aluminum chloride as an aluminum source, ethanol and deionized water as solvents, 1,2-propylene oxide as a gel promoter, and polyethylene oxide as a surfactant, the treated zirconia fiber is mixed with polyethylene oxide and ethanol, deionized water is added dropwise, and then crystalline aluminum chloride is slowly added. After dissolution, 1,2-propylene oxide is added to obtain a gel;

[0022] (3) After obtaining the gel, add isopropyl alcohol solution for aging; then remove the aging solution, wash and dry;

[0023] (4) After drying, the obtained fibers are placed in a muffle furnace for heat treatment and then ground to obtain nano-modified zirconia fibers.

[0024] As shown in the embodiments of the present invention, the present invention can ensure that the temperature of the coating substrate does not exceed 50°C for more than 15 minutes at 1300°C when the coating has a thickness of 0.05 mm. At the same time, it can also have excellent thermal shock resistance and can remain free of cracks during 50 1300°C-water temperature cycles. In addition, it can also have an anti-fouling effect on the ashes of burning wood.

[0025] As shown in the specific embodiments of the present invention, the previous research results of the inventors (i.e., CN115521695B) show that the ability to achieve high-temperature resistance of 1300°C is mainly based on the synergistic effect between radiation insulation and thermal insulation materials. Therefore, in order to solve the problem of thermal shock resistance, the inventors first considered adding other nanofibers or known thermal shock-resistant materials (graphene aerogel and vermiculite). However, unfortunately, the addition of these materials not only failed to effectively increase the thermal shock resistance, but instead caused the high-temperature resistance of the resulting coating to drop significantly. The reason may be that the synergistic effect between radiation insulation and thermal insulation materials is broken. The difficulty in obtaining this synergistic effect is also reflected in the previous research results CN115521695B and CN115521676B.

[0026] Through continuous experimentation, the inventors discovered that adding alumina-modified zirconia fibers, supplemented with polyvinyl pyrrolidone, and adjusting the specific composition of the radiant insulation and thermal insulation materials significantly alleviated the thermal shock problem. This may be because the coating raw material system of the present invention, while still achieving a synergistic effect between the radiant insulation and thermal insulation materials in terms of high temperature resistance, the addition of modified fibers enhances the rigidity of the coating, and polyvinyl pyrrolidone increases the viscosity of the coating raw material slurry, thereby improving the coating's toughness. As demonstrated in experimental examples of the present invention, the coating of the present invention remained crack-free after 50 cycles of heating and cooling from 1300°C to water temperature.

[0027] In the process of obtaining the above-mentioned technical solution of the present invention, as shown in the comparative examples of the present invention, the selection of different radiation insulation and thermal insulation materials also has a huge impact on the high temperature resistance of the resulting coating, and the selection of the combination of the two materials is crucial for the generation of synergistic effects. At present, although the present invention has found that the additional addition of fibers can enhance the thermal shock resistance of the coating, which is consistent with the general understanding in the field, the fibers need to undergo special surface modification, and the modified fibers cannot destroy the synergistic effect between the radiation insulation and thermal insulation materials. Based on this discovery, the inventor speculates that the surface properties of the nano-oxide mixture in previous research results may be an important influencing factor in obtaining the synergistic effect between the two materials mentioned above.

[0028] In addition, generally speaking, graphene aerogel has the characteristics of light weight and high elasticity, and can be used to make thermal insulation materials with a certain thermal shock resistance effect. Based on this characteristic, it can be combined with vermiculite that expands and bends when heated to improve the thermal shock resistance of the coating. However, it may be because graphene aerogel also has high adsorption properties. After adding graphene aerogel, the spatial contact basis between the aforementioned radiation insulation and thermal insulation materials is destroyed, thereby destroying the synergistic effect between the two, resulting in a significant decrease in the high temperature resistance of the coating, causing the overall performance of the coating to be outweighed by the gains. The polyvinyl pyrrolidone added in the present invention has relatively good water solubility and is also a commonly used raw material for heat-resistant materials. The inventor speculates that the addition of this raw material leads to an increase in the viscosity of the raw material solution and a "physical traction" between the raw materials. Thus, on the basis of improving the rigidity of the coating, the toughness of the coating is also enhanced. However, after the inventor replaced polyvinyl pyrrolidone with polyethylene oxide, a water-soluble substance that can also be used as a raw material for heat-resistant materials, the high temperature resistance of the coating also decreased significantly. Therefore, the viscosity of the coating raw material solution and the selection of radiation insulation and thermal insulation materials may also affect each other in achieving synergistic high temperature resistance.

[0029] Therefore, the contribution of the present invention to this field is: a coating material is prepared that can keep the temperature of the coating substrate below 50°C for more than 15 minutes at 1300°C, and at the same time has excellent thermal shock resistance and can produce no cracks in 50 1300°C-water temperature cycles. To obtain a coating with this kind of performance, it is necessary to ensure the synergy between the radiation insulation and thermal insulation materials in the coating raw material system in terms of high temperature resistance on the basis of improving the rigidity and toughness of the coating (which can be regarded as further improving the rigidity of the coating in all directions on the basis of improving the overall toughness of the coating; it can also be regarded as further improving the overall toughness of the coating on the basis of improving the rigidity of the coating in all directions). Among them, the surface modification of the fiber material and the viscosity of the raw material solution may be the key.

[0030] In addition, the inventor unexpectedly discovered that the obtained coating also has a good anti-fouling effect on firewood burning ash. The speculation and demonstration of the mechanism in this regard have not been carried out in the present invention.

[0031] Preferably, in the component B, except for the hollow silicon dioxide microspheres having a particle size of 200-300 nm and the nano-lithium silicate having a particle size of 10-20 nm, the particle sizes of the remaining substances are all 100-200 nm.

[0032] Preferably, the weight ratio of polyvinyl pyrrolidone, sulfobetaine and aqueous polyurethane is 5:2:3.

[0033] Preferably, when preparing the nano-modified zirconia fiber, the mass ratio of crystalline aluminum chloride, ethanol, deionized water, 1,2-propylene oxide and polyethylene oxide is 1:1.5:1.5:2:0.03; and the mass ratio of zirconia fiber to crystalline aluminum chloride is 1:8.

[0034] Preferably, when preparing the nano-modified zirconia fiber, in step (3), washing is performed with ethanol; and / or, in step (4), treatment is performed in a muffle furnace at 300° C. for 2 hours.

[0035] Preferably, the ingredients in component B, by weight, include 6 parts of magnesium aluminum hydrotalcite, 2.5 parts of diatomaceous earth, 6 parts of nano titanium dioxide, 9 parts of nano iron oxide, 6 parts of nano copper oxide, 14 parts of nano aluminum oxide, 9 parts of nano silicon dioxide, 6 parts of nano zinc borate, 4 parts of nano tungsten trioxide, 6 parts of nano aluminum silicate fiber, 23 parts of hollow silicon dioxide microspheres, 4 parts of nano lithium silicate, 6 parts of nano lanthanum oxide, and 13 parts of nano modified zirconia fiber.

[0036] Preferably, the weight ratio of component A, component B and component C is 11:10:2.

[0037] The present invention also provides a method for preparing the coating, which comprises mixing the components uniformly and adding water and stirring during the mixing.

[0038] Preferably, the components are mixed according to the weight portions of each component in component B, deionized water is added, and the mixture is stirred uniformly at 1000-1500 rpm at 50-60° C.; component C is then added, stirred at 1000-1500 rpm at 50-60° C., and finally component A is added, and the mixture is stirred uniformly at 2000-2500 rpm at 50-60° C. to obtain the product.

[0039] The present invention also provides the use of the high-temperature resistant lightweight coating prepared by the above method as a coating for drones. In practical applications, the thickness of the coating may not exceed 0.1 mm.

[0040] Beneficial effects of the present invention:

[0041] The high-temperature resistant lightweight coating provided by the present invention has an excellent thermal insulation effect. When the obtained coating thickness is 0.05 mm, the temperature of the coating substrate can be kept below 50°C for more than 15 minutes at 1300°C. It also has excellent thermal shock resistance and can withstand 50 1300°C-water temperature cycles without cracking. In addition, it can also have an anti-fouling effect on the ashes of burning wood. DETAILED DESCRIPTION

[0042] The present invention is described in detail below through examples. It is necessary to point out that the following examples are only used to further illustrate the present invention and are not to be construed as limiting the scope of protection of the present invention. Non-essential improvements and adjustments made by those skilled in the art based on the above-mentioned invention still fall within the scope of protection of the present invention.

[0043] In the following experiments, the experimental materials and test methods used are as follows:

[0044] Experimental materials:

[0045] Silica hollow microspheres: laboratory-produced, with a particle size of 200-300 nm (Note: This particle size is a particle size range, indicating that the particle size of the raw material is within this range, not the exact value; the particle size of other raw materials has the same meaning);

[0046] Nano-titanium dioxide, nano-iron oxide, nano-copper oxide, nano-aluminum oxide, nano-silicon dioxide, nano-zinc borate, nano-tungsten trioxide, nano-lanthanum oxide, nano-aluminum silicate fiber, and diatomaceous earth were purchased from Hefei AVIC Nano-Technology Development Co., Ltd., with a particle size of 100-200 nm.

[0047] Magnesium aluminum hydrotalcite: purchased from Jinan Shenghe Chemical Co., Ltd., with a particle size of 100-200 nm;

[0048] Nano-lithium silicate: purchased from Jinan Shenghe Chemical Co., Ltd., particle size 10-20 nm;

[0049] Polyvinylpyrrolidone (CAS: 9003-39-8): purchased from Jinan Shenghe Chemical Co., Ltd.

[0050] Sulfobetaine: laboratory-owned;

[0051] Waterborne polyurethane: prepared according to reference (DOI:10.19319 / j.cnki.issn.1008-021x.2019.21.003).

[0052] Nano-modified zirconia fibers were prepared in-house by the following method:

[0053] (1) The zirconia fiber was placed in hydrochloric acid (0.6 mol / L) and heated (70°C, 2 hours), washed and dried (80°C) to obtain the treated zirconia fiber;

[0054] (2) Using crystalline aluminum chloride as an aluminum source, ethanol and deionized water as solvents, 1,2-propylene oxide as a gel promoter and polyethylene oxide as a surfactant, the treated zirconia fiber is mixed with polyethylene oxide and ethanol, deionized water is added dropwise, and then the crystalline aluminum chloride is slowly added. After dissolution, 1,2-propylene oxide is added to obtain a gel; wherein the weight ratio of crystalline aluminum chloride, ethanol, deionized water, 1,2-propylene oxide and polyethylene oxide is 1:1.5:1.5:2:0.03; the mass ratio of zirconia fiber to crystalline aluminum chloride is 1:8;

[0055] (3) After obtaining the gel, add isopropanol solution (stand for 10 hours) for aging; then remove the aging solution, wash with ethanol and dry (80°C);

[0056] (4) After drying, the fiber was placed in a muffle furnace for heat treatment (300°C, 2 hours) and then ground to obtain nano-modified zirconia fibers (100-200 nm).

[0057] Thermal insulation performance test: Fix the blowtorch, aim the flame at the center of the sample, and burn the flame vertically onto the sample. At the same time, use an infrared thermometer to test the temperature of the back of the tinplate sheet.

[0058] Heat resistance test

[0059] Place the sample in a muffle furnace and heat it to 1300°C at 10°C / min for 2 hours. Allow it to cool down and observe and record whether the coating has any delamination, peeling, bubbling, cracking, etc. after it cools down to room temperature (25°C). The coating substrate is a ceramic substrate.

[0060] Thermal shock resistance test: The sample is kept at 1300℃ for 5 minutes, quenched in water (25℃) (the temperature is reduced to 25℃), and blown dry. This is recorded as one thermal shock cycle. Multiple thermal shock cycles are performed, with cracks visible to the naked eye in sufficient sunlight as the inspection standard.

[0061] Anti-fouling test: Prepare wood burning ash (primarily ash and fine particles). After heating the sample to 600°C, spread the ash over the sample surface until it completely covers the sample. After cooling naturally, purge the sample surface with compressed air at a pressure of 0.4 MPa using a 5mm aperture, a 20cm distance between the spray gun outlet and the sample, and a 1-minute purge cycle. Repeat this cycle five times. Visually inspect the sample coating to determine if there are any visible stains.

[0062] Example 1

[0063] Prepare the following materials by weight:

[0064] 6 parts of magnesium aluminum hydrotalcite, 2.5 parts of diatomaceous earth, 6 parts of nano titanium dioxide, 9 parts of nano iron oxide, 6 parts of nano copper oxide, 14 parts of nano aluminum oxide, 9 parts of nano silicon dioxide, 6 parts of nano zinc borate, 4 parts of nano tungsten trioxide, 6 parts of nano aluminum silicate fiber, 23 parts of hollow silicon dioxide microspheres, 4 parts of nano lithium silicate, 6 parts of nano lanthanum oxide, and 13 parts of modified zirconium oxide fiber, which together constitute component B, a total of 114.5 parts by weight;

[0065] Component A consists of 75 parts of polyvinyl pyrrolidone, 30 parts of sulfobetaine, and 45 parts of waterborne polyurethane, totaling 150 parts by weight;

[0066] 9 parts of ethylene glycol and 12 parts of vinyltrimethoxysilane constitute component C, totaling 21 parts by weight.

[0067] Mix the ingredients in component B, add deionized water (solid-liquid ratio of 50-55%, the same as in other embodiments), and stir evenly at 1500 rpm at 50-60°C for 30 minutes; then add component C, stir at 1500 rpm at 50-60°C for 20 minutes, and finally add component A, stir at 2500 rpm at 50-60°C for 30 minutes, and then apply the coating.

[0068] Example 2

[0069] Reference Example 1, on the basis of which component B is adjusted to:

[0070] 5 parts of magnesium aluminum hydrotalcite, 3 parts of diatomaceous earth, 5 parts of nano titanium dioxide, 10 parts of nano iron oxide, 8 parts of nano copper oxide, 12 parts of nano aluminum oxide, 8 parts of nano silicon dioxide, 8 parts of nano zinc borate, 3 parts of nano tungsten trioxide, 5 parts of nano aluminum silicate fiber, 25 parts of hollow silicon dioxide microspheres, 3 parts of nano lithium silicate, 8 parts of nano lanthanum oxide, and 15 nano modified zirconia fiber.

[0071] The weight ratio of component A, component B and component C was adjusted to 160:120:23.

[0072] Example 3

[0073] Reference Example 1, on the basis of which component B is adjusted to:

[0074] 7 parts of magnesium aluminum hydrotalcite, 2 parts of diatomaceous earth, 7 parts of nano titanium dioxide, 8 parts of nano iron oxide, 5 parts of nano copper oxide, 15 parts of nano aluminum oxide, 10 parts of nano silicon dioxide, 5 parts of nano zinc borate, 5 parts of nano tungsten trioxide, 8 nano aluminum silicate fiber, 22 parts of hollow silicon dioxide microspheres, 5 nano lithium silicate, 5 parts of nano lanthanum oxide, and 12 nano modified zirconia fiber.

[0075] The weight ratio of component A, component B and component C was adjusted to 140:110:18.

[0076] The above examples 1-3 were tested, and the test results are shown in Table 1:

[0077] Table 1

[0078]

[0079] Note 1: In Table 1, the thermal insulation performance test was conducted with an external flame temperature of 1300-1350°C, a coating thickness of 0.05mm, and a tinplate substrate (4.6mm thick). The thermal insulation time is the time the temperature of the tinplate backside remains below 50°C while the flame is directed at the coating.

[0080] Note 2: In Table 1, the “apparent condition after ablation” reflects the results of the heat resistance test. Smooth means that there is no delamination, peeling, blistering, cracking, etc., and the coating is in a smooth state.

[0081] Note 3: In Table 1, the "Number of Thermal Shock Cycles" reflects the number of thermal shock cycles required for visible cracks to develop after the thermal shock test of the present invention. For example, a thermal shock cycle of 53 indicates that visible cracks only developed after 53 thermal shock cycles.

[0082] Note 4: The temperature rise in Example 1 of this patent is similar to that in Example 1 of CN 115521676 B. Similarly, the temperature rises significantly from 31.4°C to 42.5°C between 6.5 and 8.5 minutes. It then rises steadily to 48.8°C over the next 15.5 minutes, and then suddenly rises to 92.5°C between 15.5 and 16.5 minutes. The temperature rise diagram can be found in CN 115521676 B and is not described in this patent.

[0083] In addition, after the anti-fouling test, no visible stains were found on the samples of Examples 1-3.

[0084] Comparative Example 1

[0085] The coating was prepared with reference to Example 1 of CN 115521676 B.

[0086] Comparative Example 2

[0087] The coating was prepared with reference to Example 1 of CN 115521695 B.

[0088] Comparative Example 3

[0089] Based on Example 1 of CN 115521676 B, 5 parts of nanographene aerogel (prepared in the laboratory, with a particle size of 200-300 nm) and 3 parts of nanovermiculite (prepared in the laboratory, with a particle size of 50-100 nm) were added, and other aspects were consistent with the example.

[0090] Comparative Example 4

[0091] The polyvinyl pyrrolidone in Example 1 was replaced by polyethylene oxide, and the rest remained the same as in the example.

[0092] Comparative Example 5

[0093] On the basis of Example 1 of this patent, in addition to the nano-modified zirconia fiber, the remaining substances of component B are replaced by a mixture of nano-yttrium oxide, nano-alumina, nano-alumina, nano-magnesium oxide, nano-silica, and nano-zinc borate in a weight ratio of 2:5:7:2:2:1.

[0094] Comparative Example 6

[0095] Based on Example 1 of CN 115521695 B, 3 parts of nano-zirconia fibers were added to component C, and the rest remained unchanged.

[0096] The above comparative examples 1-6 were tested, and the test results are shown in Table 2:

[0097] Table 2

[0098]

[0099] Note: Except for the “-” which means that due to poor insulation effect, it is not necessary to conduct a 2-hour heat resistance test, the rest of the notes are in Table 1.

Claims

1. A high temperature resistant lightweight coating, characterized in that: The coating comprises the following components A, B and C; The ingredients of component A include polyvinyl pyrrolidone, sulfobetaine and water-based polyurethane; The ingredients in component B, calculated by weight, include 5-7 parts of magnesium aluminum hydrotalcite, 2-3 parts of diatomaceous earth, 5-7 parts of nano titanium dioxide, 8-10 parts of nano iron oxide, 5-8 parts of nano copper oxide, 12-15 parts of nano aluminum oxide, 8-10 parts of nano silicon dioxide, 5-8 parts of nano zinc borate, 3-5 parts of nano tungsten trioxide, 5-8 parts of nano aluminum silicate fiber, 22-25 parts of hollow silicon dioxide microspheres, 3-5 parts of nano lithium silicate, 5-8 parts of nano lanthanum oxide, and 12-15 parts of nano modified zirconia fiber; The components in component C are composed of ethylene glycol and vinyltrimethoxysilane in a weight ratio of 3:4; The weight ratio of component A, component B and component C is (140-160):(110-120):(18-23); The nano-modified zirconia fiber is obtained by the following preparation method: (1) placing the zirconium oxide fiber in hydrochloric acid for heating treatment, washing and drying to obtain the treated zirconium oxide fiber; (2) Using crystalline aluminum chloride as an aluminum source, ethanol and deionized water as solvents, 1,2-propylene oxide as a gel promoter, and polyethylene oxide as a surfactant, the treated zirconia fiber is mixed with polyethylene oxide and ethanol, deionized water is added dropwise, and then crystalline aluminum chloride is slowly added. After dissolution, 1,2-propylene oxide is added to obtain a gel; (3) adding isopropyl alcohol solution to the obtained gel for aging; Then remove the aging liquid, wash and dry; (4) After drying, the obtained fibers are placed in a muffle furnace for heat treatment and then ground to obtain nano-modified zirconia fibers.

2. The high temperature resistant lightweight coating according to claim 1, characterized in that: In the component B, except for the hollow silicon dioxide microspheres having a particle size of 200-300 nm and the nano-lithium silicate having a particle size of 10-20 nm, the particle sizes of the remaining substances are all 100-200 nm.

3. The high temperature resistant lightweight coating according to claim 1, characterized in that: The weight ratio of the polyvinyl pyrrolidone, sulfobetaine and aqueous polyurethane is 5:2:

3.

4. The high temperature resistant lightweight coating according to claim 1, characterized in that: When preparing the nano-modified zirconia fiber, the mass ratio of crystalline aluminum chloride, ethanol, deionized water, 1,2-propylene oxide and polyethylene oxide is 1:1.5:1.5:2:0.03; the mass ratio of zirconia fiber to crystalline aluminum chloride is 1:

8.

5. The high temperature resistant lightweight coating according to claim 4, characterized in that: When preparing the nano-modified zirconia fiber, in step (3), washing is performed with ethanol; and / or, in step (4), treating is performed in a muffle furnace at 300° C. for 2 hours.

6. The high temperature resistant lightweight coating according to claim 1, characterized in that: The ingredients in component B, by weight, include 6 parts of magnesium aluminum hydrotalcite, 2.5 parts of diatomaceous earth, 6 parts of nano titanium dioxide, 9 parts of nano iron oxide, 6 parts of nano copper oxide, 14 parts of nano aluminum oxide, 9 parts of nano silicon dioxide, 6 parts of nano zinc borate, 4 parts of nano tungsten trioxide, 6 parts of nano aluminum silicate fiber, 23 parts of hollow silicon dioxide microspheres, 4 parts of nano lithium silicate, 6 parts of nano lanthanum oxide, and 13 parts of nano modified zirconia fiber.

7. The high temperature resistant lightweight coating according to claim 1, characterized in that: The weight ratio of component A, component B and component C is 150:114.5:

21.

8. A method for preparing a high-temperature resistant lightweight coating, characterized in that: The high-temperature resistant lightweight coating is the high-temperature resistant lightweight coating according to any one of claims 1 to 7, and the preparation method is to mix the components evenly and add water and stir during mixing.

9. The preparation method according to claim 8, characterized in that Mix the components according to the weight parts of each component in component B, add deionized water, and stir evenly at 50-60°C and 1000-1500 rpm; then add component C, stir at 50-60°C and 1000-1500 rpm, and finally add component A, and stir evenly at 50-60°C and 2000-2500 rpm to obtain the product.

10. Use of the high-temperature resistant lightweight coating according to any one of claims 1 to 7 or the high-temperature resistant lightweight coating prepared by the preparation method according to claim 8 or 9 as a coating for unmanned aerial vehicles, characterized in that: The thickness of the coating does not exceed 0.1mm.

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