High-temperature-resistant and scratch-resistant lightweight coating, preparation method thereof, and application on drones

Abstract

The present invention provides a high-temperature resistant and scratch-resistant lightweight coating. The coating components include hollow silica microspheres, zeolite, lithium silicate, magnesium aluminum hydrotalcite, diatomaceous earth, nano-tungsten trioxide, nano-titanium dioxide, nano-zirconium oxide, nano-copper oxide, nano-aluminum trioxide, nano-silicon dioxide, nano-zinc borate, nano-lanthanum oxide, ethylene glycol, sulfobetaine, vinyltrimethoxysilane, and water-based polyurethane. The high-temperature resistant lightweight coating provided by the present invention has excellent thermal insulation effect. When the resulting coating thickness is 0.05 mm, the temperature of the coating substrate is kept below 50°C for more than 15 minutes at 1300°C. It also has excellent hydrogen sulfide corrosion resistance and scratch resistance, and can survive 30 cycles of 1300°C hydrogen sulfide gas environment without significantly affecting the scratch resistance.

Description

Technical Field

[0001] This patent belongs to the field of new material technology and involves coating material preparation technology, in particular, a high-temperature resistant and scratch-resistant lightweight coating, its preparation method, and its application in drones. Background Art

[0002] In recent years, the performance requirements for coatings of special equipment have been increasing, among which high temperature resistance is an important consideration for special equipment that needs to enter high temperature environments.

[0003] In 2022, the inventor team first proposed the technical concept of a "lightweight" and "high-temperature resistant" coating and completed the corresponding technical research and development. Among the related technical achievements, a technical solution was proposed to combine materials with "irradiation thermal insulation" performance and materials with "irradiation heat insulation" performance, and to ensure that the resulting coating reaches an excellent high-temperature resistant effect of no more than 50°C at a temperature of 1300°C within 15 minutes. Based on this, the inventor applied for two invention patents CN115521676B and CN115521695B. The aforementioned technology of the inventor team overcomes problems such as Shen Hang [1] The traditional coating obtained by et al. has the defect that it is difficult to control the temperature of the back side of the coating to reach the operating temperature of general electronic equipment (i.e. below 50°C) at high temperature.

[0004] To further research the aforementioned "lightweight" and "high-temperature-resistant" coating system, the inventor team conducted in-depth research on the shortcomings of existing coatings in terms of thermal shock resistance, and on October 30, 2023, they applied for a lightweight coating material that is both high-temperature-resistant and thermal-shock-resistant (Acceptance Number 202311431106.2). This patent addresses the problem of coating cracking or peeling that can occur when a drone enters a fire scene, either due to falling into water or being sprayed by firefighting water, suddenly experiencing a low-temperature environment when exposed to high temperatures.

[0005] In addition to thermal shock, fires easily generate hydrogen sulfide gas, which can corrode drone coatings. Repeated exposure to hydrogen sulfide can lead to a reduction in scratch resistance due to corrosion. The inventors have discovered through experiments that the scratch resistance of the coating obtained in CN115521695B significantly decreases after repeated exposure to high temperatures and hydrogen sulfide. Therefore, addressing this issue is crucial to ensuring that the resulting coating can extend the service life of drones.

[0006] Existing technologies for coatings against hydrogen sulfide corrosion are mainly focused on petroleum and petrochemical equipment. This is because hydrogen sulfide, as a dissolved gas, exists in crude oil or geological water and can cause severe corrosion to drilling and production equipment. Generally speaking, due to the low demand for lightweighting in petroleum and petrochemical equipment, the thickness of the anti-corrosion coating for these equipment is usually more than 0.3mm.[2] , making it difficult to achieve lightweighting. More importantly, the equipment in this field does not have many requirements for high-temperature resistance. This makes it difficult to apply the hydrogen sulfide corrosion-resistant coatings developed in the petroleum and petrochemical industry to the development of high-temperature resistant, lightweight, and hydrogen sulfide corrosion-resistant coatings for drones.

[0007] Therefore, how to prepare a coating that can ensure that the drone components in the coating can operate in a working environment with a temperature of no more than 50°C for a long time in a temperature environment of 1300°C, while also making the resulting coating have good resistance to hydrogen sulfide corrosion and scratch resistance, is a problem that needs to be further solved in this field.

[0008] [1] Shen Hang. Application of water-based base materials in the construction of ultra-thin steel structure fire retardant and anti-corrosion coating system[J]. Coatings Industry, 2018, 48(04): 35-42.

[0009] [2] Wang Lei, Ding Chao, Kang Shaowei, et al. Research and application of graphene-modified high-efficiency anti-corrosion coating technology for H_2S acidic media[J]. Electroplating and Finishing, 2021, 40(14): 1101-1109. DOI: 10.19289 / j.1004-227x.2021.14.008. Summary of the Invention

[0010] In response to the defects 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 is not higher than 50°C within 15 minutes at a temperature of 1300°C; it also has excellent hydrogen sulfide corrosion resistance and scratch resistance, and can undergo 30 cycles of 1300°C-hydrogen sulfide gas environment without significantly affecting the scratch resistance.

[0011] Therefore, unless otherwise specified, the "high-temperature resistant and scratch-resistant lightweight coating" referred to in the present invention should be understood as a coating material that can meet the above requirements.

[0012] In order to achieve the above object, the technical solution provided by the present invention is as follows:

[0013] A high-temperature resistant and scratch-resistant lightweight coating, characterized in that the coating comprises the following components A, B and C;

[0014] The components of component A include, by weight, 25 to 28 parts of hollow silicon dioxide microspheres, 12 to 15 parts of zeolite, and 5 parts of lithium silicate;

[0015] The ingredients in component B, calculated by weight, include 3 to 5 parts of magnesium aluminum hydrotalcite, 5 to 7 parts of diatomaceous earth, 6 to 8 parts of nano tungsten trioxide, 3 to 5 parts of nano titanium dioxide, 3 to 5 parts of nano zirconium oxide, 3 to 5 parts of nano copper oxide, 12 to 15 parts of nano aluminum oxide, 3 to 5 parts of nano silicon dioxide, 5 to 8 parts of nano zinc borate, and 3 to 5 parts of nano lanthanum oxide;

[0016] The components in component C are composed of ethylene glycol, sulfobetaine, vinyltrimethoxysilane, and waterborne polyurethane in a weight ratio of 2:1:4:20-25;

[0017] The weight ratio of component A, component B and component C is (40-50):(60-70):(100-110).

[0018] As shown in the embodiments of the present invention, the present invention can ensure that the temperature of the coating substrate is not higher than 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 not significantly affect the anti-scratch performance during 30 cycles of 1300°C-hydrogen sulfide gas environment.

[0019] As shown in a comparative example of the present invention, the coating obtained by the inventor team's previous research results CN115521695B has good salt spray resistance and certain scratch resistance. However, after a long period of observation, the inventor team found that the coating's high temperature resistance decreased after frequently entering the hydrogen sulfide gas environment, causing overheating and damage to the internal components of the drone. In response to this phenomenon, the inventor team designed a high-temperature-hydrogen sulfide gas environment test scheme. Among them, the high temperature test still uses 1300°C, and the hydrogen sulfide gas test environment refers to the "Determination of Hydrogen Sulfide Gas Corrosion Test Method" [3] After testing, the inventors found that the scratch resistance and high temperature resistance of the coating obtained from CN115521695B decreased after 13 cycles.

[0020] After extensive experimentation, the inventors discovered that, without changing their previously discovered technique of combining materials with "radiation heat-insulating" and "radiation heat-insulating" properties, by adjusting the composition of components A, B, and C, they significantly enhanced the coating's resistance to hydrogen sulfide corrosion while maintaining its lightweight and high-temperature properties. The introduction of zeolite and the adjustment of the other components were crucial.

[0021] To the best of the inventors' knowledge, there are few reports on the use of zeolites in coatings to combat hydrogen sulfide corrosion, and the underlying mechanism remains unclear. Furthermore, the inventors have discovered that the addition of zeolites is not the sole key to achieving the performance of the coatings obtained in this invention. Therefore, further enhancing the coating's corrosion and scratch resistance, while maintaining high-temperature resistance, remains a challenging technical research and development task, as the underlying mechanisms remain unclear.

[0022] The contribution of the present invention to the field lies in: preparing a method that can keep the temperature of the coating substrate below 50°C for more than 15 minutes at 1300°C, while also having excellent thermal shock resistance and being able to have no significant impact on the scratch resistance during 30 cycles of 1300°C-hydrogen sulfide gas environment.

[0023] Preferably, in the component A, the particle size of lithium silicate is 10-20 nm, and the particle size of zeolite and hollow silica microspheres is 200-300 nm.

[0024] Preferably, in the component B, the particle size of the various nano-oxides is 200 to 300 nm.

[0025] Preferably, component A comprises, by weight, 26 parts of hollow silicon dioxide microspheres, 13 parts of zeolite, and 5 parts of lithium silicate.

[0026] Preferably, the ingredients in component C are composed of ethylene glycol, sulfobetaine, vinyltrimethoxysilane and waterborne polyurethane in a weight ratio of 2:1:4:22.

[0027] Preferably, the ingredients in component B, by weight, include 4 parts of magnesium aluminum hydrotalcite, 6 parts of diatomaceous earth, 7 parts of nano tungsten trioxide, 4 parts of nano titanium dioxide, 4 parts of nano zirconium oxide, 4 parts of nano copper oxide, 13 parts of nano aluminum oxide, 4 parts of nano silicon dioxide, 6 parts of nano zinc borate, and 4 parts of nano lanthanum oxide.

[0028] Preferably, the weight ratio of component A, component B and component C is 9:13:21.

[0029] 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.

[0030] 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.

[0031] The present invention also provides the use of the high-temperature resistant and scratch-resistant lightweight coating prepared by the above method as a coating for drones. In practical applications, the thickness of the coating can be no more than 0.1 mm.

[0032] [3] Wu Mingli, Liu Fuying. Determination of the test method for hydrogen sulfide gas corrosion[J]. Special Electrician, 1978, (03): 43-63.

[0033] Beneficial effects of the present invention:

[0034] 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. At the same time, it also has excellent hydrogen sulfide corrosion resistance and scratch resistance, and can be cycled in 30 1300°C-hydrogen sulfide gas environments without significantly affecting the scratch resistance. DETAILED DESCRIPTION

[0035] 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.

[0036] In the following experiments, the experimental materials and test methods used are as follows:

[0037] Experimental materials:

[0038] 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);

[0039] Diatomaceous earth, nano-tungsten trioxide, nano-titanium dioxide, nano-zirconium oxide, nano-copper oxide, nano-aluminum trioxide, nano-silicon dioxide, nano-zinc borate, and nano-lanthanum oxide were purchased from Hefei AVIC Nano-Technology Development Co., Ltd., with a particle size of 100-200 nm.

[0040] Magnesium aluminum hydrotalcite: purchased from Jinan Shenghe Chemical Co., Ltd., with a particle size of 100-200 nm;

[0041] Nano-lithium silicate: purchased from Jinan Shenghe Chemical Co., Ltd., particle size 10-20 nm;

[0042] Sulfobetaine: laboratory-owned;

[0043] Ethylene glycol: laboratory-owned;

[0044] Vinyltrimethoxysilane: purchased from Merck;

[0045] Waterborne polyurethane: prepared according to reference (DOI:10.19319 / j.cnki.issn.1008-021x.2019.21.003).

[0046] 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.

[0047] Heat resistance test: Place the sample in a muffle furnace and heat it to 1300°C at 10°C / min for 2 hours. Allow to cool. After cooling to room temperature (25°C), observe and record whether the coating has any delamination, peeling, bubbling, cracking, etc. The coating substrate is a ceramic substrate.

[0048] Scratch resistance test: Load a 500g weight on one side of a sand-containing scouring pad and repeatedly scratch the surface of the coating at a certain speed (0.5m / s). The maximum number of scratches without leaving visible scratches is used to characterize the scratch resistance of the coating.

[0049] Hydrogen sulfide resistance test: The sample is kept at 1300℃ for 5 minutes, cooled naturally to 50℃, and then placed in a box with a hydrogen sulfide gas concentration of 200mg / L (relative humidity 80%, temperature 50℃) for 3 hours. This is recorded as one test cycle, and the changes in the cooling performance and scratch resistance of the coating after the test cycle are examined. If the insulation time obtained in the cooling performance test is less than 15 minutes, and the number of scratches in the scratch resistance test is less than 32 times, it is considered unqualified.

[0050] Example 1

[0051] Prepare the following materials by weight:

[0052] Prepare, by weight, 4 parts of magnesium aluminum hydrotalcite, 6 parts of diatomaceous earth, 7 parts of nano tungsten trioxide, 4 parts of nano titanium dioxide, 4 parts of nano zirconium oxide, 4 parts of nano copper oxide, 13 parts of nano aluminum oxide, 4 parts of nano silicon dioxide, 6 parts of nano zinc borate, and 4 parts of nano lanthanum oxide to form component B;

[0053] Prepare Component A by weight: 26 parts of hollow silica microspheres, 13 parts of zeolite, and 5 parts of lithium silicate;

[0054] Component C is composed of ethylene glycol, sulfobetaine, vinyltrimethoxysilane and waterborne polyurethane in a weight ratio of 2:1:4:22.

[0055] The weight ratio of component A, component B and component C is 9:13:21

[0056] Mix the ingredients in component B, add deionized water (solid-to-liquid ratio of 50-55%, the same for other embodiments), and stir evenly at 1500 rpm / min at 50-60°C for 30 minutes; then add component C, stir at 1500 rpm / min at 50-60°C for 20 minutes, and finally add component A, stir at 2500 rpm / min at 50-60°C for 30 minutes, and then apply the coating.

[0057] Example 2

[0058] Reference Example 1, on the basis of which component B is adjusted to:

[0059] 5 parts of magnesium aluminum hydrotalcite, 5 parts of diatomaceous earth, 8 parts of nano tungsten trioxide, 5 parts of nano titanium dioxide, 3 parts of nano zirconium oxide, 5 parts of nano copper oxide, 15 parts of nano aluminum oxide, 3 parts of nano silicon dioxide, 5 parts of nano zinc borate, and 3 parts of nano lanthanum oxide.

[0060] Component A is adjusted to 28 parts of hollow silica microspheres, 15 parts of zeolite, and 5 parts of lithium silicate.

[0061] The weight ratio of component A, component B and component C was adjusted to 4:7:11.

[0062] Example 3

[0063] Reference Example 1, on the basis of which component B is adjusted to:

[0064] 3 parts of magnesium aluminum hydrotalcite, 7 parts of diatomaceous earth, 6 parts of nano tungsten trioxide, 3 parts of nano titanium dioxide, 5 parts of nano zirconium oxide, 3 parts of nano copper oxide, 12 parts of nano aluminum oxide, 5 parts of nano silicon dioxide, 8 parts of nano zinc borate, and 5 parts of nano lanthanum oxide.

[0065] The weight ratio of component A, component B and component C was adjusted to 5:6:10.

[0066] The above examples 1-3 were tested, and the test results are shown in Table 1:

[0067] Table 1

[0068]

[0069] 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.

[0070] 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.

[0071] Note 3: In Table 1, the "Number of Test Cycles" reflects the number of test cycles after the hydrogen sulfide resistance test of this invention that resulted in the coating being deemed unqualified. The failure criteria are described in the aforementioned test specifications. For example, a thermal shock cycle count of 37 indicates that the coating's cooling time only dropped below 15 minutes and the scratch resistance count only fell below 32 after 37 test cycles.

[0072] 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 31.1°C to 42.9°C in the 6.0-9.0 minute period. It then rises steadily to 47.6°C over the next 15.0 minutes, then to 49.1°C over the 15.0-16.0 minute period, and finally abruptly rises to 96.1°C over the 16.0-17.5 minute period. The temperature rise diagram can be found in CN 115521676 B and is not described further in this patent.

[0073] Comparative Example 1

[0074] The coating was prepared with reference to Example 1 of CN 115521676 B.

[0075] Comparative Example 2

[0076] The coating was prepared with reference to Example 1 of CN 115521695 B.

[0077] Comparative Example 3

[0078] Except for not adding zeolite, the rest is the same as Example 1.

[0079] Comparative Example 4

[0080] In Example 1 of CN 115521695 B, 15 parts of zeolite are added to component A, and the rest are consistent with Example 1 of the patent.

[0081] Comparative Example 5

[0082] On the basis of Example 1 of this patent, component B is adjusted to component B of Example 1 of CN 115521695 B, and the rest is consistent with Example 1 of this patent.

[0083] The above comparative examples 1-5 were tested, and the test results are shown in Table 2:

[0084] Table 2

[0085]

[0086] Note: Except for “-” which means that due to poor insulation effect, it is not necessary to conduct a 2-hour heat resistance test, the rest of the content refers to Table 1.

Claims

1. A high temperature resistant and scratch resistant lightweight coating, characterized in that: The coating comprises the following components A, B and C; The components of component A include, by weight, 25 to 28 parts of hollow silicon dioxide microspheres, 12 to 15 parts of zeolite, and 5 parts of lithium silicate; The ingredients in component B, calculated by weight, include 3 to 5 parts of magnesium aluminum hydrotalcite, 5 to 7 parts of diatomaceous earth, 6 to 8 parts of nano tungsten trioxide, 3 to 5 parts of nano titanium dioxide, 3 to 5 parts of nano zirconium oxide, 3 to 5 parts of nano copper oxide, 12 to 15 parts of nano aluminum oxide, 3 to 5 parts of nano silicon dioxide, 5 to 8 parts of nano zinc borate, and 3 to 5 parts of nano lanthanum oxide; The components in component C are composed of ethylene glycol, sulfobetaine, vinyltrimethoxysilane, and waterborne polyurethane in a weight ratio of 2:1:4:20-25; The weight ratio of component A, component B and component C is (40-50):(60-70):(100-110).

2. The high temperature resistant and scratch resistant lightweight coating according to claim 1, characterized in that: In the component A, the particle size of lithium silicate is 10-20 nm, and the particle size of zeolite and hollow silicon dioxide microspheres is 200-300 nm.

3. The high temperature resistant and scratch resistant lightweight coating according to claim 1, characterized in that: In the component B, the particle size of various nano-oxides is 200-300 nm.

4. The high temperature resistant and scratch resistant lightweight coating according to claim 1, characterized in that: Component A comprises, by weight, 26 parts of hollow silicon dioxide microspheres, 13 parts of zeolite, and 5 parts of lithium silicate.

5. The high temperature resistant and scratch resistant lightweight coating according to claim 4, characterized in that: The components in component C are composed of ethylene glycol, sulfobetaine, vinyltrimethoxysilane and waterborne polyurethane in a weight ratio of 2:1:4:

22.

6. The high temperature resistant and scratch resistant lightweight coating according to claim 1, characterized in that: The ingredients in component B, by weight, include 4 parts of magnesium aluminum hydrotalcite, 6 parts of diatomaceous earth, 7 parts of nano tungsten trioxide, 4 parts of nano titanium dioxide, 4 parts of nano zirconium oxide, 4 parts of nano copper oxide, 13 parts of nano aluminum oxide, 4 parts of nano silicon dioxide, 6 parts of nano zinc borate, and 4 parts of nano lanthanum oxide.

7. The high temperature resistant and scratch resistant lightweight coating according to claim 1, characterized in that: The weight ratio of component A, component B and component C is 9:13:

21.

8. A method for preparing a high-temperature resistant and scratch-resistant lightweight coating, characterized in that: The high-temperature resistant and scratch-resistant lightweight coating is the high-temperature resistant and scratch-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 and scratch-resistant lightweight coating according to any one of claims 1 to 8 or the high-temperature resistant and scratch-resistant lightweight coating prepared by the preparation method according to claim 8 or 9 as a coating for an unmanned aerial vehicle, characterized in that: The thickness of the coating does not exceed 0.1mm.

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