Metal surface thermal protection coating as well as preparation method and application thereof

Abstract

The invention discloses a metal surface thermal protection coating as well as a preparation method and application thereof, and relates to a heavy-load unmanned aerial vehicle thermal protection coating as well as a preparation method and application thereof. The invention aims to solve the problems that the heat resistance of a thermal protection coating on the surface of a fuselage metal plate below an engine tail nozzle of an existing heavy-load unmanned aerial vehicle is lower than 150 DEG C, the bonding strength of the coating and metal is lower than 2MPa, and a paint film is loose and low in bearing strength. The coating is prepared from acrylic organic silicon emulsion, ceramic microbeads, aluminum silicate fibers, silicon dioxide aerogel, titanium dioxide, iron black, distilled water, dipropylene glycol butyl ether, dipropylene glycol monomethyl ether, a dispersing agent, a defoaming agent, an anti-settling agent, auxiliaries and a silane coupling agent. The problem of heat insulation protection of the surface of a fuselage metal plate under the long-term working condition of 200 DEG C below a heavy-load unmanned aerial vehicle tail nozzle is solved, a coating formed by the prepared metal surface thermal protection paint on the metal surface is good in temperature resistance, the short-term temperature resistance can reach 300 DEG C, and the metal bonding strength is gt; the pressure is 3MPa.

Description

Technical Field

[0001] The present invention relates to a thermal protective coating for a heavy-loaded unmanned aerial vehicle (UAV), a preparation method thereof, and applications thereof. Background Art

[0002] Lightweight alloys (such as aluminum alloys, titanium alloys, etc.) are widely used as structural materials in aerospace, energy and power and other fields due to their excellent specific strength and corrosion resistance. However, under the operating conditions of a certain type of heavy-loaded UAV, the heat flow from the engine tail nozzle will cause significant thermal shock to the fuselage plate below, causing local areas to be in a high temperature environment of 200°C or even above 300°C for a short period of time. Unlike instantaneous high temperature, although the absolute temperature of this condition is not high, the heating time is long, which can last for several hours to span the operating phase of the heavy-loaded UAV. This extreme working condition not only requires the material itself to have good heat resistance, but also ensures that adjacent key components such as electronic equipment and sensors are not affected by high temperatures to avoid performance degradation or failure due to heat conduction or heat radiation. Therefore, the development of efficient and stable metal surface thermal protection coating technology has become the key to solving such problems.

[0003] Currently, organic thermal insulation coatings commonly used in industry are mainly based on film-forming materials such as acrylic emulsions, epoxy resin emulsions, or polyurethane resins, supplemented with thermal insulation fillers such as glass microspheres and aerogels. However, such coatings have the following limitations:

[0004] 1. Insufficient temperature resistance: The long-term temperature resistance limit of traditional acrylic, epoxy, or polyurethane coatings is generally below 150°C. They are prone to thermal oxidative degradation in environments above 200°C, resulting in cross-linking network breakage, coating powdering, or peeling.

[0005] 2. Mechanical performance defects: The bonding strength between the coating and the metal substrate is usually less than 2MPa. After curing, the structure is loose and the pressure bearing capacity is poor, making it difficult to adapt to the high dynamic load conditions of heavy-load UAV fuselages.

[0006] 3. Insufficient stability: Although the coating of cold-blended commercially available acrylic emulsion and silicone emulsion can achieve both adhesion and temperature resistance, it has problems such as poor compatibility and easy phase separation, and its performance degrades significantly under long-term high temperature.

[0007] To address these issues, existing technologies attempt to improve performance through organic-inorganic hybridization or resin modification. For example, acrylic resins provide excellent metal adhesion, while silicones impart high-temperature resistance and chemical inertness to the coating. However, simple physical blending of the two makes it difficult to achieve molecular-level synergistic effects, resulting in limited improvements in the coating's overall performance. Therefore, a new resin synthesis and coating design method is urgently needed that integrates the advantages of acrylic and silicone at the molecular level while simultaneously addressing the synergistic optimization of temperature resistance, bonding strength, and thermal stability.

[0008] The present application is based on this background, proposes to prepare acrylic-silicone hybrid emulsion by crosslinking polymerization method, aims to break through the performance bottleneck of traditional coating, and provides a more reliable solution for metal thermal protection under high temperature working condition. SUMMARY

[0009] The present application aims to solve the problems of heat resistance of the existing heavy-duty unmanned aerial vehicle engine tail nozzle under the metal plate surface of the fuselage, the bonding strength of the coating and the metal is less than 2MPa, and the loose pressure strength of the paint film is low, and provides a metal surface thermal protection coating and its preparation method and application.

[0010] A metal surface thermal protection coating is prepared from 20-60 parts by mass of acrylic silicone emulsion, 10-20 parts of ceramic microbead 0-1#, 10-20 parts of ceramic microbead 0-2#, 10-15 parts of aluminum silicate fiber, 5-10 parts of silica aerogel, 2-5 parts of titanium white, 2-5 parts of iron black, 20-30 parts of distilled water, 2-5 parts of dipropylene glycol butyl ether, 2-5 parts of dipropylene glycol methyl ether, 0.5-1 part of dispersant, 0.5-1 part of defoamer, 0.2-0.8 part of anti-settling agent, 0.5-1 part of auxiliary agent and 1-3 parts of silane coupling agent.

[0011] A preparation method of a metal surface thermal protection coating, specifically is completed by the following steps:

[0012] I. 20-60 parts by mass of acrylic silicone emulsion, 10-20 parts of ceramic microbead 0-1#, 10-20 parts of ceramic microbead 0-2#, 10-15 parts of aluminum silicate fiber, 5-10 parts of silica aerogel, 2-5 parts of titanium white, 2-5 parts of iron black, 20-30 parts of distilled water, 2-5 parts of dipropylene glycol butyl ether, 2-5 parts of dipropylene glycol methyl ether, 0.5-1 part of dispersant, 0.5-1 part of defoamer, 0.2-0.8 part of anti-settling agent, 0.5-1 part of auxiliary agent and 1-3 parts of silane coupling agent are taken by mass fraction;

[0013] II. The distilled water, dipropylene glycol butyl ether, dipropylene glycol methyl ether, dispersant and defoamer are mixed uniformly, and then the titanium white, iron black, anti-settling agent, auxiliary agent and silane coupling agent are added under stirring conditions, and the grinder is used to grind to a fineness of <50μm to obtain a color paste;

[0014] III. The acrylic silicone emulsion and the color paste are mixed uniformly, and then the aluminum silicate fiber is added under stirring conditions, and stirred for a period of time, and then the ceramic microbead 0-1#, ceramic microbead 0-2# and silica aerogel are sequentially added, and stirred for a period of time to obtain the metal surface thermal protection coating.

[0015] A metal surface thermal protection coating is used as a thermal protection coating on the metal surface; the construction process is completed by the following steps:

[0016] The substrate is polished to a surface roughness Ra>3.5μm, a water-based epoxy primer is sprayed on the polished substrate surface, and after the primer is dry, a metal surface thermal protection coating is sprayed on the substrate surface, and the coating is naturally dried at room temperature to obtain a thermal protection coating on the substrate surface;

[0017] The substrate is aluminum alloy, titanium alloy or stainless steel;

[0018] The spraying thickness of the waterborne epoxy primer is 60 μm to 100 μm;

[0019] The spraying thickness of the metal surface thermal protection coating is 2mm~4mm.

[0020] Principle of the present invention:

[0021] 1. The metal surface thermal protection coating prepared by this invention utilizes an acrylic silicone emulsion. During the pre-emulsification stage of acrylic monomers (such as methyl methacrylate and butyl acrylate), a double-bond silicone monomer (such as vinyltrimethoxysilane) is introduced stepwise. This results in in-situ block copolymerization of acrylic and siloxane segments through controlled free radical polymerization, rather than simple physical blending. After the coating cures, the siloxane undergoes hydrolysis and condensation to form a three-dimensional crosslinked network, resulting in a coating with a bond strength of ≥3 MPa at 200°C (a 150% improvement compared to traditional cold-blended emulsions).

[0022] Second, the metal surface thermal protection coating prepared in this invention uses ceramic microbeads 0-1# and ceramic microbeads 0-2#. Adjusting the volume filling ratio of the two microbeads forms a tightly packed structure, significantly improving the coating's pressure-bearing capacity while maintaining thermal insulation.

[0023] 3. The metal surface thermal protection coating prepared by the present invention uses aluminum silicate fiber. The fiber structure and low thermal conductivity of aluminum silicate fiber significantly improve the compressive strength of the coating film when added to the coating and help the coating film resist cracking.

[0024] Fourth, the metal surface thermal protection coating prepared by this invention utilizes silica aerogel. During the coating's curing process, the silica aerogel permeates and fills the voids within the three-dimensional framework constructed of aluminum silicate fibers and ceramic microspheres, forming a multi-level gradient insulation structure. This reduces the coating's thermal diffusivity at 200°C by extending the heat flow path, thereby improving overall thermal insulation performance.

[0025] 5. R900 titanium dioxide is used in the metal surface thermal protection coating prepared by the present invention. R900 titanium dioxide has an extremely high reflectivity (up to 80% to 90%) for visible light and near-infrared rays in sunlight (accounting for more than 50% of solar thermal energy), which can effectively reduce heat absorption and lower the surface temperature. In addition, titanium dioxide itself has a low thermal conductivity coefficient, which can reduce the transfer of heat through the coating to the substrate; R900 titanium dioxide has excellent weather resistance, which helps to extend the outdoor service life of the coating.

[0026] 6. Iron black is used in the metal surface thermal protective coating prepared by the present invention. Iron black as a coloring pigment has good temperature resistance and high cost performance, and is unified with the color matching of heavy-load drones.

[0027] 7. The metal surface thermal protection coating prepared by the present invention uses a silane coupling agent, which has a modifying effect on the thermal insulation material and significantly improves the tensile strength of the coating.

[0028] Advantages of the present invention:

[0029] The present invention solves the problem of thermal insulation protection of the metal sheet surface of the fuselage under the long-term 200°C working condition below the tail nozzle of the heavy-load UAV engine. The metal surface thermal protection coating prepared by the present invention forms a coating on the metal surface with good temperature resistance, and the short-term temperature resistance can reach 300°C. Other specific effects are shown in Table 1.

[0030] Table 1

[0031] DETAILED DESCRIPTION

[0032] Specific embodiment 1: This embodiment is a metal surface thermal protective coating, which is prepared by weight from 20 to 60 parts of acrylic silicone emulsion, 10 to 20 parts of ceramic microbeads 0-1#, 10 to 20 parts of ceramic microbeads 0-2#, 10 to 15 parts of aluminum silicate fiber, 5 to 10 parts of silica aerogel, 2 to 5 parts of titanium dioxide, 2 to 5 parts of iron black, 20 to 30 parts of distilled water, 2 to 5 parts of dipropylene glycol butyl ether, 2 to 5 parts of dipropylene glycol methyl ether, 0.5 to 1 part of dispersant, 0.5 to 1 part of defoaming agent, 0.2 to 0.8 parts of anti-settling agent, 0.5 to 1 part of auxiliary agent and 1 to 3 parts of silane coupling agent.

[0033] Specific embodiment 2: This embodiment differs from specific embodiment 1 in that the preparation method of the acrylic silicone emulsion is specifically completed according to the following steps:

[0034] ①. Synthetic acrylic silicone resin:

[0035] Mixing the silicone resin and the acrylic resin uniformly according to the mass ratio (10-25):(15-30), adding the organic metal catalyst, heating to 70-120℃, and reacting for 2-10h to obtain an acrylic silicone resin with a solid content of 85-95% and a viscosity of 1000-2000cp;

[0036] ②, Emulsification of the acrylic silicone resin:

[0037] Adding the emulsifier to the acrylic silicone resin with a solid content of 85-95% and a viscosity of 1000-2000cp, and then adding deionized water at a stirring speed of 1000-1500r / min to obtain an acrylic silicone emulsion with a solid content of 50±2% and a viscosity of 300-500cp. The other steps are the same as in Embodiment One.

[0038] Embodiment Three: The difference between this embodiment and Embodiments One or Two is that the silicone resin in step ① is IC232, purchased from Wacker Chemie AG; the acrylic resin in step ① is BS1996, purchased from Jiangsu Sanmu Group Co., Ltd.; and the organic metal catalyst in step ① is cobalt naphthenate. The other steps are the same as in Embodiments One or Two.

[0039] Embodiment Four: The difference between this embodiment and Embodiments One to Three is that the emulsifier in step ② is one of OP-10 and AEO-9 or a mixture of the two; and the mass ratio of the emulsifier to the acrylic silicone resin in step ② is (5-10):100. The other steps are the same as in Embodiments One to Three.

[0040] Embodiment Five: The difference between this embodiment and Embodiments One to Four is that the ceramic microbeads 0-1# have a particle size of 40-50μm and are hollow silicate microbeads, purchased from Shenzhen Dongyou New Material Co., Ltd.; and the ceramic microbeads 0-2# have a particle size of 50-60μm and are hollow silicate microbeads, purchased from Shenzhen Dongyou New Material Co., Ltd. The other steps are the same as in Embodiments One to Four.

[0041] Embodiment Six: The difference between this embodiment and Embodiments One to Five is that the aluminum silicate fiber is JW aluminum silicate fiber, purchased from Zhejiang Jiwei Refractory Materials Co., Ltd.; the titanium white is titanium white R900, purchased from Kobo; the iron black is iron black BLACK B-260, purchased from Jiangxi Dingrui New Materials Co., Ltd.; and the dispersant is dispersant BYK-190, purchased from Wacker Chemie AG. The other steps are the same as in Embodiments One to Five.

[0042] Specific embodiment 7: This embodiment differs from specific embodiments 1 to 6 in that the defoamer is TEGO 8030, purchased from Evonik; the anti-settling agent is anti-settling agent LT, purchased from Hemmings, Inc.; the additive is AMP-95, purchased from Dow Chemical; and the silane coupling agent is CoatOSil 1770, purchased from Momentive Advanced Materials Group. The other steps are the same as specific embodiments 1 to 6.

[0043] Specific embodiment eight: This embodiment differs from specific embodiments one to seven in that the preparation method is specifically completed according to the following steps:

[0044] 1. Weigh 20-60 parts of acrylic silicone emulsion, 10-20 parts of ceramic microbeads 0-1#, 10-20 parts of ceramic microbeads 0-2#, 10-15 parts of aluminum silicate fiber, 5-10 parts of silica aerogel, 2-5 parts of titanium dioxide, 2-5 parts of iron black, 20-30 parts of distilled water, 2-5 parts of dipropylene glycol butyl ether, 2-5 parts of dipropylene glycol methyl ether, 0.5-1 part of dispersant, 0.5-1 part of defoamer, 0.2-0.8 part of anti-settling agent, 0.5-1 part of auxiliary agent and 1-3 parts of silane coupling agent according to the following parts by mass;

[0045] 2. Evenly mix distilled water, dipropylene glycol butyl ether, dipropylene glycol methyl ether, dispersant and defoamer, then add titanium dioxide, iron black, anti-settling agent, additives and silane coupling agent under stirring, and grind with a grinder to a fineness of <50 μm to obtain a color paste;

[0046] 3. Evenly mix the acrylic silicone emulsion and color paste, then add aluminum silicate fiber while stirring. Stir for a period of time. Then, sequentially add ceramic microbeads 0-1#, ceramic microbeads 0-2#, and silica aerogel. Stir for a period of time to obtain a metal surface thermal protective coating. The remaining steps are the same as in Specific Embodiments 1 to 7.

[0047] Specific Embodiment 9: This embodiment differs from Specific Embodiments 1 to 8 in that the stirring time in step 3 is 30 to 40 minutes, and the stirring speed is 600 to 800 rpm. The metal surface thermal protection coating in step 3 has a temperature resistance of up to 300°C. The other steps are the same as Specific Embodiments 1 to 8.

[0048] Specific embodiment 10: This embodiment differs from specific embodiments 1 to 9 in that: a metal surface thermal protection paint is used as a thermal protection coating on the metal surface; the construction process is completed according to the following steps:

[0049] The substrate is polished to a surface roughness Ra>3.5μm, a water-based epoxy primer is sprayed on the polished substrate surface, and after the primer is dry, a metal surface thermal protection coating is sprayed on the substrate surface, and the coating is naturally dried at room temperature to obtain a thermal protection coating on the substrate surface;

[0050] The substrate is aluminum alloy, titanium alloy or stainless steel;

[0051] The spraying thickness of the waterborne epoxy primer is 60 μm to 100 μm;

[0052] The thickness of the metal surface thermal protection coating sprayed is 2 mm to 4 mm. The other steps are the same as those of the first to ninth embodiments.

[0053] The following examples are used to verify the beneficial effects of the present invention:

[0054] Example 1: A method for preparing a metal surface thermal protective coating is specifically completed according to the following steps:

[0055] 1. Weigh the following components in parts by mass: 40 parts acrylic silicone emulsion, 15 parts ceramic microbeads 0-1#, 0 parts ceramic microbeads 0-2#, 0 parts aluminum silicate fiber, 5 parts silica aerogel, 3 parts titanium dioxide, 5 parts iron black, 25.7 parts distilled water, 3 parts dipropylene glycol butyl ether, 3 parts dipropylene glycol methyl ether, 1 part dispersant, 0.8 parts defoaming agent, 0.5 parts anti-settling agent, 1 part auxiliary agent, and 2 parts silane coupling agent;

[0056] The preparation method of the acrylic silicone emulsion is specifically completed according to the following steps:

[0057] ①. Synthetic acrylic silicone resin:

[0058] The organic silicone resin and the acrylic resin were mixed uniformly in a mass ratio of 20:20, and an organic metal catalyst was added. The mixture was heated to 105°C, reacted for 4 hours, and distilled under reduced pressure to obtain an acrylic organic silicone resin with a solid content of 85% to 95% and a viscosity of 1000 cp to 2000 cp.

[0059] The model of the organic silicone resin described in step ① is IC232, purchased from Wacker Chemie Co., Ltd. in Germany; the model of the acrylic resin described in step ① is BS1996, purchased from Jiangsu Sanmu Group Co., Ltd.;

[0060] The organometallic catalyst described in step ① is cobalt naphthenate;

[0061] ②. Emulsification of acrylic silicone resin:

[0062] The acrylic silicone resin with solid content of 85%~95% and viscosity of 1000cp~2000cp is added with emulsifier for high-speed emulsification, and then deionized water is added under stirring at a speed of 700r / min to obtain the acrylic silicone emulsion with solid content of 50±2% and viscosity of 300cp~500cp;

[0063] The emulsifier in step ② is a mixture of OP-10 and AEO-9, wherein the mass ratio of OP-10 to AEO-9 is 1:1;

[0064] The mass ratio of the emulsifier in step ② to the acrylic silicone resin is 7:100;

[0065] The ceramic microbead 0-1# has a particle size of 40~50μm and is a hollow silicate microbead, which is purchased from Shenzhen Dongyou New Material Co., Ltd.;

[0066] The ceramic microbead 0-2# has a particle size of 50~60μm and is a hollow silicate microbead, which is purchased from Shenzhen Dongyou New Material Co., Ltd.;

[0067] The aluminum silicate fiber is JW aluminum silicate fiber, which is purchased from Zhejiang Jiwei Refractory Material Co., Ltd.; and the titanium white is titanium white R900, which is purchased from KOMO;

[0068] The iron black is iron black BLACK B-260, which is purchased from Jiangxi Dingrui New Material Co., Ltd.;

[0069] The dispersant is dispersant BYK-190, which is purchased from Germany BYK-Chemie Co., Ltd.;

[0070] The defoaming agent is defoaming agent TEGO 8030, which is purchased from Wacker Chemie AG;

[0071] The anti-settling agent is anti-settling agent LT, which is purchased from American Hanninges Co., Ltd.;

[0072] The auxiliary agent is AMP-95, which is purchased from Dow Chemical Company;

[0073] The silane coupling agent is CoatOSil 1770, which is purchased from Meitu High New Material Group;

[0074] II. Distilled water, dipropylene glycol butyl ether, dipropylene glycol methyl ether, dispersant and defoaming agent are mixed uniformly, and then titanium white, iron black, anti-settling agent, auxiliary agent and silane coupling agent are added under stirring, and a grinder is used to grind to a fineness of <50μm to obtain a color paste;

[0075] 3. Evenly mix the acrylic silicone emulsion and the color paste, then add the aluminum silicate fiber under stirring, stir for 30 minutes, then add ceramic microbeads 0-1#, ceramic microbeads 0-2# and silica aerogel in sequence, stir for 30 minutes to obtain a metal surface thermal protection coating;

[0076] The stirring speed in step 3 is 700 r / min;

[0077] Fourth, the substrate is polished until the surface roughness Ra>3.5μm, and a water-based epoxy primer is sprayed on the polished substrate surface. After the primer is dry, a metal surface thermal protection coating is sprayed on the substrate surface and naturally dried at room temperature to obtain a thermal protection coating on the substrate surface;

[0078] The substrate is aluminum alloy, titanium alloy or stainless steel;

[0079] The spraying thickness of the waterborne epoxy primer is 80 μm;

[0080] The spraying thickness of the metal surface thermal protection coating is 3mm.

[0081] Example 2: This example differs from Example 1 in that in step 1, 40 parts of acrylic silicone emulsion, 15 parts of ceramic microbeads 0-1#, 0 parts of ceramic microbeads 0-2#, 15 parts of aluminum silicate fiber, 5 parts of silica aerogel, 3 parts of titanium dioxide, 5 parts of iron black, 25.7 parts of distilled water, 3 parts of dipropylene glycol butyl ether, 3 parts of dipropylene glycol methyl ether, 1 part of dispersant, 0.8 part of defoamer, 0.5 part of anti-settling agent, 1 part of auxiliary agent, and 2 parts of silane coupling agent were weighed in the following amounts by mass. Other steps and parameters were the same as in Example 1.

[0082] Example 3: This example differs from Example 1 in that in step 1, 40 parts of acrylic silicone emulsion, 0 parts of ceramic microbeads 0-1#, 15 parts of ceramic microbeads 0-2#, 15 parts of aluminum silicate fiber, 5 parts of silica aerogel, 3 parts of titanium dioxide, 5 parts of iron black, 25.7 parts of distilled water, 3 parts of dipropylene glycol butyl ether, 3 parts of dipropylene glycol methyl ether, 1 part of dispersant, 0.8 parts of defoamer, 0.5 parts of anti-settling agent, 1 part of auxiliary agent, and 2 parts of silane coupling agent were weighed in the following amounts by mass. Other steps and parameters were the same as in Example 1.

[0083] Example 4: This example differs from Example 1 in that in step 1, 40 parts of acrylic silicone emulsion, 0 parts of ceramic microbeads 0-1#, 0 parts of ceramic microbeads 0-2#, 15 parts of aluminum silicate fiber, 10 parts of silica aerogel, 3 parts of titanium dioxide, 5 parts of iron black, 25.7 parts of distilled water, 3 parts of dipropylene glycol butyl ether, 3 parts of dipropylene glycol methyl ether, 1 part of dispersant, 0.8 parts of defoamer, 0.5 parts of anti-settling agent, 1 part of auxiliary agent, and 2 parts of silane coupling agent were weighed in the following amounts by mass. Other steps and parameters were the same as in Example 1.

[0084] Example 5: The difference between this example and Example 1 is that in Step 1, 40 parts of acrylic silicone emulsion, 8 parts of ceramic microbead 0-1#, 8 parts of ceramic microbead 0-2#, 15 parts of aluminum silicate fiber, 5 parts of silica aerogel, 3 parts of titanium white, 5 parts of iron black, 25.7 parts of distilled water, 3 parts of dipropylene glycol butyl ether, 3 parts of dipropylene glycol methyl ether, 1 part of dispersing agent, 0.8 parts of defoaming agent, 0.5 parts of anti-settling agent, 1 part of auxiliary agent and 2 parts of silane coupling agent are taken by mass fraction. The other steps and parameters are the same as those in Example 1.

[0085] Example 6: The difference between this example and Example 1 is that in Step 1, 40 parts of acrylic silicone emulsion, 8 parts of ceramic microbead 0-1#, 8 parts of ceramic microbead 0-2#, 15 parts of aluminum silicate fiber, 10 parts of silica aerogel, 3 parts of titanium white, 5 parts of iron black, 25.7 parts of distilled water, 3 parts of dipropylene glycol butyl ether, 3 parts of dipropylene glycol methyl ether, 1 part of dispersing agent, 0.8 parts of defoaming agent, 0.5 parts of anti-settling agent, 1 part of auxiliary agent and 2 parts of silane coupling agent are taken by mass fraction. The other steps and parameters are the same as those in Example 1.

[0086] The thermal protection coating obtained on the surface of the substrate in Examples 1-6 is detected, as shown in Table 2.

[0087] Table 2

[0088]

[0089] Example 7: The difference between this example and Example 3 is that: ①, synthesis of acrylic silicone resin: mix the silicone resin and the acrylic resin uniformly according to the mass ratio of 25:15. The other steps and parameters are the same as those in Example 3.

[0090] Example 8: The difference between this example and Example 3 is that: ①, synthesis of acrylic silicone resin: mix the silicone resin and the acrylic resin uniformly according to the mass ratio of 15:25. The other steps and parameters are the same as those in Example 3.

[0091] Example 9: The difference between this example and Example 3 is that: ①, synthesis of acrylic silicone resin: mix the silicone resin and the acrylic resin uniformly according to the mass ratio of 30:10. The other steps and parameters are the same as those in Example 3.

[0092] Comparative Example 1: This example differs from Example 1 in that, in step 1, 40 parts of the acrylic silicone emulsion is replaced with 20 parts of a water-based acrylic resin CH-X-2159 and 20 parts of a water-based silicone resin FNMT-3014. Specifically, in step 1, 20 parts of the water-based acrylic resin CH-X-2159, 20 parts of the water-based silicone resin FNMT-3014, 15 parts of ceramic microbeads 0-1#, 0 parts of ceramic microbeads 0-2#, 0 parts of aluminum silicate fiber, 5 parts of silica aerogel, 3 parts of titanium dioxide, 5 parts of iron black, 25.7 parts of distilled water, 3 parts of dipropylene glycol butyl ether, 3 parts of dipropylene glycol methyl ether, 1 part of a dispersant, 0.8 parts of a defoamer, 0.5 parts of an anti-settling agent, 1 part of an auxiliary agent, and 2 parts of a silane coupling agent are weighed in the following amounts by mass. Other steps and parameters are the same as in Example 1.

[0093] The waterborne acrylic resin CH-X-2159 described in Comparative Example 1 was purchased from Defuler (Shanghai) Trading Co., Ltd.

[0094] The water-based silicone resin FNMT-3014 described in Comparative Example 1 was purchased from Hangzhou Nuotu New Material Technology Co., Ltd.

[0095] The thermal protective coatings obtained on the substrate surface of Examples 3, 7 to 9 and Comparative Example 1 were tested, as shown in Table 3;

[0096] Table 3

[0097]

[0098] The comprehensive performance of Example 5 and Example 9 was tested, as shown in Table 4;

[0099] Table 4

[0100]

Claims

1. A metal surface thermal protection coating, characterized in that The coating is prepared from 20 to 60 parts by mass of acrylic silicone emulsion, 10 to 20 parts of ceramic microbeads 0-1#, 10 to 20 parts of ceramic microbeads 0-2#, 10 to 15 parts of aluminum silicate fiber, 5 to 10 parts of silica aerogel, 2 to 5 parts of titanium dioxide, 2 to 5 parts of iron black, 20 to 30 parts of distilled water, 2 to 5 parts of dipropylene glycol butyl ether, 2 to 5 parts of dipropylene glycol methyl ether, 0.5 to 1 part of dispersant, 0.5 to 1 part of defoaming agent, 0.2 to 0.8 part of anti-settling agent, 0.5 to 1 part of auxiliary agent and 1 to 3 parts of silane coupling agent.

2. A metal surface thermal protection coating according to claim 1, characterized in that The preparation method of the acrylic silicone emulsion is specifically completed according to the following steps: ①. Synthetic acrylic silicone resin: The organic silicone resin and the acrylic resin are uniformly mixed in a mass ratio of (10-25):(15-30), and then an organic metal catalyst is added, and the mixture is heated to 70°C-120°C and reacted for 2h-10h to obtain an acrylic organic silicone resin with a solid content of 85%-95% and a viscosity of 1000cp-2000cp; ②. Emulsification of acrylic silicone resin: An emulsifier was added to an acrylic silicone resin having a solid content of 85% to 95% and a viscosity of 1000 cp to 2000 cp for emulsification, and then deionized water was added at a stirring speed of 1000 r / min to 1500 r / min to obtain an acrylic silicone emulsion having a solid content of 50±2% and a viscosity of 300 cp to 500 cp.

3. A metal surface thermal protection coating according to claim 2, characterized in that The model of the organic silicon resin described in step ① is IC232; the model of the acrylic resin described in step ① is BS1996; and the organic metal catalyst described in step ① is cobalt naphthenate.

4. A metal surface thermal protection coating according to claim 2, characterized in that The emulsifier described in step ② is a mixture of one or both of OP-10 and AEO-9; the mass ratio of the emulsifier described in step ② to the acrylic silicone resin is (5~10):

100.

5. The metal surface thermal protection coating according to claim 1, characterized in that The particle size of the ceramic microbeads 0-1# is 40-50 μm, and the material is hollow silicate microbeads; the particle size of the ceramic microbeads 0-2# is 50-60 μm, and the material is hollow silicate microbeads.

6. The metal surface thermal protection coating according to claim 1, characterized in that The aluminum silicate fiber is JW aluminum silicate fiber; the titanium dioxide is titanium dioxide R900; the iron black is iron black BLACK B-260; and the dispersant is dispersant BYK-190.

7. The metal surface thermal protection coating according to claim 1, characterized in that The defoaming agent is defoaming agent TEGO8030; the anti-settling agent is anti-settling agent LT; the auxiliary agent is AMP-95; and the silane coupling agent is CoatOSil 1770.

8. The method for preparing a metal surface thermal protective coating according to claim 1, characterized in that The preparation method is specifically completed according to the following steps:

1. Weigh 20-60 parts of acrylic silicone emulsion, 10-20 parts of ceramic microbeads 0-1#, 10-20 parts of ceramic microbeads 0-2#, 10-15 parts of aluminum silicate fiber, 5-10 parts of silica aerogel, 2-5 parts of titanium dioxide, 2-5 parts of iron black, 20-30 parts of distilled water, 2-5 parts of dipropylene glycol butyl ether, 2-5 parts of dipropylene glycol methyl ether, 0.5-1 part of dispersant, 0.5-1 part of defoamer, 0.2-0.8 part of anti-settling agent, 0.5-1 part of auxiliary agent and 1-3 parts of silane coupling agent according to the following parts by mass; 2. Evenly mix distilled water, dipropylene glycol butyl ether, dipropylene glycol methyl ether, dispersant and defoamer, then add titanium dioxide, iron black, anti-settling agent, additives and silane coupling agent under stirring, and grind with a grinder to a fineness of <50 μm to obtain a color paste; 3. Evenly mix the acrylic silicone emulsion and color paste, then add aluminum silicate fiber under stirring, stir for a while, then add ceramic microbeads 0-1#, ceramic microbeads 0-2# and silica aerogel in sequence, stir for a while to obtain a metal surface thermal protection coating.

9. The method for preparing a metal surface thermal protective coating according to claim 8, characterized in that The stirring time in step 3 is 30 min to 40 min, and the stirring speed is 600 r / min to 800 r / min; the metal surface thermal protection coating in step 3 can withstand a temperature of up to 300°C.

10. The use of a metal surface thermal protection coating according to claim 1, characterized in that A metal surface thermal protection coating is used as a thermal protection coating on a metal surface; the construction process is completed in the following steps: The substrate is polished to a surface roughness Ra>3.5μm, a water-based epoxy primer is sprayed on the polished substrate surface, and after the primer is dry, a metal surface thermal protection coating is sprayed on the substrate surface, and the coating is naturally dried at room temperature to obtain a thermal protection coating on the substrate surface; The substrate is aluminum alloy, titanium alloy or stainless steel; The spraying thickness of the waterborne epoxy primer is 60 μm to 100 μm; The spraying thickness of the metal surface thermal protection coating is 2mm~4mm.

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