High-temperature-resistant elastic protective coating for radome and preparation method of high-temperature-resistant elastic protective coating

Abstract

The invention discloses a high-temperature-resistant elastic protective coating for a radome, the high-temperature-resistant elastic protective coating is composed of a component A and a component B according to a mass ratio of 1.5: 1-2: 1, and the component A is composed of polycarbonate triol resin, high-temperature-resistant inorganic pigment, conductive carbon fiber, mica powder, a dispersing agent, a leveling agent, a defoaming agent, a catalyst, a mixed solvent and the like. The component B is high-temperature-resistant elastic isocyanate resin synthesized from dihydroxyl-terminated organosilicon prepolymers with different molecular weights, polycarbonate diol, trimethylolpropane, a diisocyanate monomer, a catalyst and a solvent, has excellent rain erosion resistance, antistatic property and elastic property, and has excellent adhesive force and elastic matching property with the radome. The radome can be used on different types of high-sound-speed aircrafts, and the working reliability of the radome is improved.

Description

Technical Field

[0001] This invention belongs to the field of polymer synthesis technology, specifically relating to a high-temperature resistant elastic protective coating for radar domes and its preparation method. Background Technology

[0002] The radome is an important component of an aircraft and serves as a window to electromagnetic waves. Its function is to protect the antenna, prevent environmental influences and interference on the radar antenna's operating status, thereby reducing the power required to drive the antenna, improving its reliability, and ensuring all-weather operation of the radar antenna.

[0003] When an aircraft flies in complex environments, the radome is subjected to rain erosion, sand and gravel erosion, and static electricity generated on its surface due to intense friction with the air. In order to protect the radome's mechanical properties, antistatic properties, and electromagnetic wave transmission efficiency, and to ensure the normal functioning of the radar—that is, to maintain its performance under various environments—a protective coating must be applied to the radome surface.

[0004] As aircraft speeds increase, high-speed aircraft face intense aerodynamic heating during flight. When the speed exceeds Mach 2.5, the surface temperature of the aircraft radome can reach around 220°C. Currently available aliphatic radome protective coatings do not have high-temperature resistance (approximately 170°C). Prolonged exposure to 220°C will cause the elastic polyurethane resin in the coating to decompose, resulting in yellowing, failure, blistering, and peeling, thus failing to meet actual usage requirements.

[0005] Existing elastic protective coatings for radomes are mainly prepared by compounding elastic polyurethane with weather-resistant pigments and fillers, antistatic fillers, etc., which can meet the application requirements in a temperature range of -55℃ to 170℃. However, the 220℃ temperature generated by aerodynamic heating during long-term flight of hypersonic aircraft will cause the base resin of existing elastic protective coatings for radomes to decompose and fail, resulting in a sharp drop in elasticity, aging resistance, rain erosion resistance and antistatic properties, thus failing to protect the radome. Summary of the Invention

[0006] The purpose of this invention is to address the issue that existing elastic protective coatings for radomes cannot meet high-temperature resistance requirements (220℃ / 24h), and lose their protective function after long-term use. This invention synthesizes a high-temperature resistant silicone-modified elastic polyurethane resin using high-molecular-weight, double-terminated hydroxyl organosilicon prepolymer, polycarbonate diol, and diisocyanate monomers. High-temperature resistant inorganic pigments and fillers, along with high-temperature resistant conductive carbon fibers, are added to prepare a high-temperature resistant elastic protective coating for radomes. This coating can be used on the surface of hypersonic aircraft radomes, providing high-temperature resistance, antistatic properties, and protection against rain erosion.

[0007] This invention discloses a high-temperature resistant elastic protective coating for radar domes, mainly composed of component A and component B in a mass ratio of 1.5:1 to 2:1. Component A consists of polycarbonate triol resin, high-temperature resistant inorganic pigments, conductive carbon fibers, mica powder, dispersant, leveling agent, defoamer, catalyst, and mixed solvent. Component B is a high-temperature resistant elastic isocyanate resin synthesized from prepolymers of different molecular weights with dihydroxyl-terminated organosilicon, polycarbonate diol, trimethylolpropane, diisocyanate monomer, catalyst, and solvent.

[0008] The formula for component A, by mass percentage, is as follows: Polycarbonate triol 24%~28% High-temperature resistant inorganic pigments: 28%~31% Mica powder 9%~12% Conductive carbon fiber 4%~6% Organosilicon dispersant 2%~3.5% Organosilicon leveling agent 0.2%~0.3% Organosilicon defoamer 0.4%~0.5% Catalyst A 0.1%~0.2% Mixed solvent A 22%~26% The polycarbonate triol is at least one of Tosoh's PCP-100L2 and Wengjiang PB41060.

[0009] The high-temperature resistant inorganic pigment is selected from at least one of rutile titanium dioxide, cobalt blue, copper chromate black, and cadmium red.

[0010] The mica powder is at least one of GA-2, GA-4 and GD-2 with different particle sizes.

[0011] The conductive carbon fiber is at least one of different lengths of 350 micrometers, 400 micrometers, and 500 micrometers.

[0012] The organosilicon dispersant is at least one of Wyncoat® 8110A, WynCoat® DIS 8290, and WynCoat® 8104S.

[0013] The silicone leveling agent is at least one of BD-3410, BD-3432 and BD-3405.

[0014] The silicone defoamer is at least one of BYK-066N and BYK-085.

[0015] The catalyst is at least one of dibutyltin dilaurate, monobutyltin oxide, and triethylamine.

[0016] The mixed solvent is at least one of xylene, methyl ethyl ketone (MEK), and butyl acetate.

[0017] The formula for component B, by mass percentage, is as follows: 29%~31% of bihydroxyl-terminated organosilicon prepolymers Polycarbonate diol 11%~14% Trimethylolpropane 3%~4% Diisocyanate monomer 30%~33% Catalyst B 0.1%~0.15% Catalyst C 0.1%~0.2% Solvent B 20%~22%.

[0018] The B component is polymerized from a double-hydroxyl-terminated organosilicon prepolymer, polycarbonate diol, trimethylolpropane, diisocyanate monomer, catalyst, and solvent, and has an NCO content of 5% to 7%.

[0019] The hydroxyl-terminated organosilicon prepolymer is a mixture of Siwell Rebon® SR-903 and one of Siwell Rebon® SR-901 and Siwell Rebon® SR-902.

[0020] The polycarbonate diol is a mixture of one of SYH1000 and SYHP1000 with a molecular weight of 1000 and one of SYHP2000 and SYH2000 with a molecular weight of 2000, manufactured by Shuyu Chemical.

[0021] The diisocyanate monomer is at least one of HDI, IPDI and HMDI.

[0022] Catalyst B is at least one of dibutyltin dilaurate and monobutyltin oxide.

[0023] The catalyst C is triethylamine.

[0024] The mixed solvent is at least one of xylene, methyl ethyl ketone (MEK), and butyl acetate.

[0025] The preparation method of the high-temperature resistant elastic protective coating for radar domes of the present invention involves preparing materials according to the above-described formula, and the preparation process of component A is as follows: Under stirring, polycarbonate triol, organosilicon dispersant, organosilicon leveling agent, organosilicon defoamer, catalyst A and mixed solvent A are added sequentially to the mixing tank. After stirring evenly, high-temperature resistant inorganic pigment, mica powder and conductive carbon fiber are added under stirring. After stirring evenly, the mixture is ground in a basket mill for 4 hours. The surface resistance is tested and found to be between 5MΩ and 100MΩ. The material is then filtered out to obtain component A.

[0026] The preparation method of the high-temperature resistant elastic protective coating for radar domes of the present invention, according to the above-described formula, includes the following preparation process for component B: First, in a nitrogen-filled reaction flask, different molecular weight double-terminated hydroxyl organosilicon prepolymers, different molecular weight polycarbonate diols, trimethylolpropane, and solvent B are added. The mixture is heated to 125℃~135℃ and refluxed for dehydration, yielding a solution containing hydroxyl resin. Then, in another nitrogen-filled reaction flask, diisocyanate monomers and catalyst B are added as a base. The refluxed and dehydrated solution containing hydroxyl resin is then added dropwise to the reaction flask. The reaction is carried out at 70℃ for 2 hours, then at 90℃ for 2 hours. Catalyst C is then added, and the reaction is maintained at 90℃~120℃. The NCO percentage is used as the final control indicator. The mixture is then filtered to obtain component B.

[0027] Component A is a premix containing hydroxyl groups (-OH), mainly dispersed and mixed physically without chemical reaction, but it provides a crucial foundation for subsequent crosslinking. After 4 hours of grinding in a basket mill, the solid fillers (pigment, mica powder, carbon fiber) are uniformly dispersed in the elastic matrix of polycarbonate triol, forming a stable suspension. The hydroxyl groups (-OH) of the polycarbonate triol are the active sites for subsequent reaction with the isocyanate (-NCO) of component B; the conductive carbon fiber, mica powder, and other fillers impart antistatic and rain-resistant properties to the coating. Furthermore, the long-chain structure of polycarbonate triol provides the coating with flexibility, the conductive carbon fiber forms a conductive network, and the surface resistivity is controlled at 32-53 MΩ, meeting aerospace antistatic requirements; the mica powder enhances the coating's toughness and improves wear resistance; and the high-temperature resistant pigment ensures no discoloration or decomposition at 220℃.

[0028] Component B is a prepolymer containing isocyanate (-NCO), synthesized through a two-step chemical reaction to provide active groups for final crosslinking: Step 1: Hydroxyl resin synthesis (dehydration reaction). Under nitrogen protection, hydroxyl-terminated organosilicon prepolymer, polycarbonate diol, trimethylolpropane, and solvent are mixed and heated to 125-135℃ for reflux dehydration (physical dehydration to remove trace amounts of moisture from the raw materials, preventing moisture from reacting with -NCO and causing crosslinking failure). Step 2: Isocyanate prepolymerization (addition reaction). The dehydrated hydroxyl resin is added dropwise to a reaction flask containing diisocyanate, reacted at 70℃ for 2 hours, then at 90℃ for 2 hours, followed by the addition of a catalyst and incubation to obtain a prepolymer containing free -NCO (NCO content 5-7%). The polyurethane addition reaction (-NCO reacts with -OH to form urethane bonds) leaves a large number of -NCO groups at the ends of the prepolymer molecular chains, preparing for subsequent crosslinking with component A.

[0029] When component A (containing -OH) and component B (containing -NCO) are mixed at a ratio of 1.5:1 to 2:1, a polyurethane crosslinking reaction occurs, and urethane bonds are formed (-NCO + -OH → -NH-CO-O-). The -NCO groups of component B react with the -OH groups of the polycarbonate triol in component A. Simultaneously, the fillers (carbon fiber, mica powder) in component A are encapsulated in a three-dimensional network, eventually curing into a film. The high Si-O bond energy of the hydroxyl-terminated organosilicon prepolymer (452 ​​kJ / mol) imparts a high-temperature resistance of 220℃ / 24h to the coating. The -NCO groups in the prepolymer act as a "bridge" for the reaction with component A, ensuring the formation of a three-dimensional network structure after the coating cures.

[0030] The film-forming resin in this coating contains NCO functional groups, which can react with the NH bonds of the polyimide in the radome to form chemical bonds. Through the presence of a large number of polar functional groups such as hydroxyl groups, it can form hydrogen bonds and van der Waals forces with the polyimide composite material. Therefore, after the coating is sprayed onto the surface of the polyimide composite material of the radome to form a film, the cross-cut adhesion is ≤1 grade and the peel strength is ≥3kN / m.

[0031] Therefore, the three-dimensional network structure of the coating of this invention enables the coating to have a tensile strength >10MPa and an elongation at break >200%, meeting the requirements of impact resistance and rain erosion protection for radomes. It also exhibits strong adhesion; the cross-linking reaction forms a chemical bond between the coating and the polyimide composite material of the radome, achieving a cross-cut adhesion grade of 0 and a peel strength ≥3kN / m. Furthermore, it possesses high temperature resistance and weather resistance; the Si-O bonds of the organosilicon prepolymer synergistically work with the polyurethane network to ensure stable performance over a wide temperature range of -60℃ to 220℃, maintaining an elongation at break >150% and a tensile strength >10MPa even after 220℃ / 24h. SR-903, a hydroxyl-terminated silicone prepolymer, is a trihydroxyl-functionalized silicone prepolymer with a unique T-shaped structure. Both ends and side ends have hydroxyl functional groups. The T-shaped structure provides greater molecular steric hindrance, enhancing the durability of the modification effect. The three hydroxyl functional groups provide higher reactivity and crosslinking density. The presence of side-terminated hydroxyl groups broadens the scalability of the modified structure, enabling the formation of more complex crosslinking networks and improving coating brightness and durability. The linear structure of SR-901 gives it good compatibility and flowability in resin systems. The dihydroxyl structure provides moderate crosslinking ability, effectively improving resin performance. The terminal hydroxyl group of SR-902 can undergo an addition reaction with -NCO to form a polyurethane structure, which helps improve adhesion to polar substrates. The compounding of hydroxyl-terminated silicone prepolymers allows the coating to achieve a "permanent and strong" interfacial bond through a triple action of chemical crosslinking, substrate wetting, and dense coating. Through a complementary hard and soft elastic network, it balances the coating's scratch resistance and substrate deformation adaptability, preventing cracking or peeling.

[0032] Through the design of functional fillers, two-component resins, and preparation processes, these reactions collectively endow this coating with combined properties such as high-temperature stability, antistatic properties, high adhesion, and rain erosion resistance under extreme environments. This meets the extreme environmental requirements of hypersonic aircraft radomes, withstands aerodynamic heating (220℃), rain erosion, and electrostatic interference, protects antenna electromagnetic wave transmission, meets a wide temperature range of -60℃ to 220℃, resists vibration and signal interference, complies with aviation material standards (GJB 150.3A), and has electromagnetic wave transmittance compatible with radar requirements. Beneficial effects

[0033] 1) The high-temperature resistant elastic protective coating for radomes prepared by this invention has durable high-temperature resistance (220℃ / 24h), excellent rain erosion resistance, antistatic properties, and elasticity. It also exhibits excellent adhesion and elasticity matching with the radome. This allows the radome to be used on various types of hypersonic aircraft, improving their operational reliability.

[0034] 2) The high-temperature resistant elastic protective coating for radar domes prepared in this paper has an elongation at break greater than 200%, a tensile strength greater than 10 MPa, and a Shore A hardness greater than 75, which meets the requirements for rain erosion protection of radar domes. 3) The high-temperature resistant elastic protective coating for radar domes still maintains excellent antistatic and elastic properties (elongation at break greater than 150% and tensile strength greater than 10MPa) after 220℃ / 24h. 4) The high-temperature resistant elastic protective coating for the radome is sprayed onto the polyimide composite material surface of the radome to form a film. The cross-cut adhesion is ≤ Grade 1 and the peel strength is ≥ 3kN / m.

[0035] 5) High-temperature resistant elastic protective coatings for radomes can improve and enhance the rain erosion resistance, antistatic properties, aging resistance, and high and low temperature resistance (-60℃~220℃) of radome composite materials, broadening the application of radomes on aircraft with different flight speeds, improving the ability of radomes to protect antennas, and extending the service life of radomes. Detailed Implementation

[0036] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example 1

[0037] Preparation of Component A of High-Temperature Resistant Elastic Protective Coating for Radar Domes: Under stirring, 25 kg of PCP-100L2 polycarbonate triol, 2.5 kg of Wyncoat® 8110A silicone dispersant, 0.25 kg of BD-3410 silicone leveling agent, 0.45 kg of BYK-066N silicone defoamer, 0.15 kg of dibutyltin dilaurate, 10 kg of xylene, and 13 kg of butyl acetate were added sequentially to a mixing tank. After stirring evenly, 29 kg of rutile titanium dioxide, 10 kg of GA-2 mica powder, and 5 kg of 400-micron conductive carbon fiber were added under stirring. After stirring evenly, the mixture was ground in a basket mill for 4 hours. The surface resistivity was tested and found to be between 5 MΩ and 100 MΩ. The mixture was then filtered to obtain Component A.

[0038] Preparation of Component B of High-Temperature Resistant Elastic Protective Coating for Radomes: First, in a nitrogen-filled reaction flask, add 19 kg of Siwell·Rebon® SR-901 hydroxyl-terminated silicone prepolymer, 10 kg of Siwell·Rebon® SR-903 hydroxyl-terminated silicone prepolymer, 7 kg of SYH1000 polycarbonate diol, 5 kg of SYH2000 polycarbonate diol, 3.5 kg of trimethylolpropane, and 21 kg of xylene. Heat to 135°C, reflux to dehydrate, and discharge. Then, in another nitrogen-filled reaction flask, add 30 kg of IPDI diisocyanate monomer and 0.1 kg of... The dibutyltin dilaurate catalyst was used as a base, and then the refluxed and dehydrated solution containing hydroxyl resin was added dropwise to the reaction flask. The reaction was carried out at 70℃ for 2 hours and at 90℃ for 2 hours. Then, 0.15 kg of triethylamine catalyst was added and the reaction was maintained at 110℃. The NCO content was tested to be 5%~7%. The product was filtered out to obtain component B.

[0039] The mass ratio of component A to component B is 1.5:1. Example 2

[0040] Preparation of Component A of High-Temperature Resistant Elastic Protective Coating for Radar Domes: Under stirring, 25 kg of PCP-100L2 polycarbonate triol, 3 kg of WynCoat® DIS 8290 silicone dispersant, 0.25 kg of BD-3410 silicone leveling agent, 0.4 kg of BYK-085 silicone defoamer, 0.2 kg of monobutyltin oxide, 20 kg of xylene, and 4 kg of methyl ethyl ketone were added sequentially to a mixing tank. After stirring evenly, 29 kg of rutile titanium dioxide, 10 kg of GA-2 mica powder, and 4 kg of 500-micron conductive carbon fiber were added under stirring. After stirring evenly, the mixture was ground in a basket mill for 4 hours. The surface resistivity was tested and found to be between 5 MΩ and 100 MΩ. The mixture was then filtered to obtain Component A.

[0041] Preparation of Component B of High-Temperature Resistant Elastic Protective Coating for Radomes: First, in a nitrogen-filled reaction flask, add 22 kg of Siwell·Rebon® SR-902 hydroxyl-terminated silicone prepolymer, 8 kg of Siwell·Rebon® SR-903 hydroxyl-terminated silicone prepolymer, 6 kg of SYHP1000 polycarbonate diol, 6 kg of SYHP2000 polycarbonate diol, 3.5 kg of trimethylolpropane, and 21 kg of xylene. Heat to 135°C, reflux to dehydrate, and discharge. Then, in another nitrogen-filled reaction flask, add 32 kg of HMDI diisocyanate monomer and 0.15 kg of... A monobutyltin oxide catalyst was used as a base, and then the refluxed and dehydrated solution containing hydroxyl resin was added dropwise to the reaction flask. The reaction was carried out at 70°C for 2 hours and at 90°C for 2 hours. Then, 0.15 kg of triethylamine catalyst was added and the reaction was maintained at 100°C. The NCO content was tested to be 5%~7%. The product was filtered out to obtain component B.

[0042] The mass ratio of component A to component B is 1.9:1. Example 3

[0043] Preparation of Component A of High-Temperature Resistant Elastic Protective Coating for Radar Domes: Under stirring, 27 kg of PB41060 polycarbonate triol, 3 kg of WynCoat® DIS 8290 silicone dispersant, 0.2 kg of BD-3405 silicone leveling agent, 0.4 kg of BYK-085 silicone defoamer, 0.1 kg of dibutyltin dilaurate catalyst, 10 kg of xylene, 10 kg of butyl acetate, and 4 kg of butanone were added sequentially to a mixing tank. After stirring evenly, 28 kg of cobalt blue, 11 kg of GA-4 mica powder, and 5.5 kg of 350-micron conductive carbon fiber were added under stirring. After stirring evenly, the mixture was ground in a basket mill for 4 hours. The surface resistivity was tested and found to be between 5 MΩ and 100 MΩ. The mixture was then filtered to obtain Component A.

[0044] Preparation of Component B of High-Temperature Resistant Elastic Protective Coating for Radomes: First, in a nitrogen-filled reaction flask, add 22 kg of Siwell·Rebon® SR-902 hydroxyl-terminated silicone prepolymer, 8 kg of Siwell·Rebon® SR-903 hydroxyl-terminated silicone prepolymer, 7 kg of SYH1000 polycarbonate diol, 6 kg of SYHP2000 polycarbonate diol, 3.5 kg of trimethylolpropane, and 20 kg of butyl acetate. Heat to 125°C, reflux to dehydrate, and discharge. Then, in another nitrogen-filled reaction flask, add 30 kg of HDI diisocyanate monomer and 0.10 kg of… A monobutyltin oxide catalyst was used as a base, and then the refluxed and dehydrated solution containing hydroxyl resin was added dropwise to the reaction flask. The reaction was carried out at 70°C for 2 hours and at 90°C for 2 hours. Then, 0.20 kg of triethylamine catalyst was added and the reaction was maintained at 90°C. The NCO content was tested to be 5%~7%. The product was filtered out to obtain component B.

[0045] The mass ratio of component A to component B is 1.6:1.

[0046] Comparative Example 1 Preparation of Component A of Elastic Protective Coating for Radar Dome: Under stirring, 27 kg of PCL-305 polycaprolactone triol, 3 kg of BYK-110 dispersant, 0.2 kg of BD-3405 silicone leveling agent, 0.4 kg of BYK-085 silicone defoamer, 0.1 kg of dibutyltin dilaurate catalyst, 10 kg of xylene, 10 kg of butyl acetate, and 4 kg of butanone were added sequentially to a mixing tank. After stirring evenly, 28 kg of iron blue, 11 kg of GA-4 mica powder, and 5.5 kg of conductive carbon black were added under stirring. After stirring evenly, the mixture was ground in a basket mill for 4 hours. The surface resistivity was tested and found to be between 5 MΩ and 100 MΩ. The mixture was then filtered to obtain Component A.

[0047] Preparation of Component B of the Elastic Protective Coating for Radar Domes: First, in a nitrogen-filled reaction flask, add 15 kg of PCL-210N polycaprolactone diol, 28 kg of PCL-220N polycaprolactone diol, 3.5 kg of trimethylolpropane, and 20 kg of xylene. Heat to 135°C, reflux to remove water, and discharge. Then, in another nitrogen-filled reaction flask, add 30 kg of IPDI diisocyanate monomer and 0.15 kg of monobutyltin oxide catalyst as a base. Then, add the refluxed and dehydrated solution containing hydroxyl resin dropwise to the reaction flask. React at 70°C for 2 hours, and maintain the reaction at 90°C. The NCO percentage is tested to be 5%~7%. Filter and discharge to obtain Component B.

[0048] The mass ratio of component A to component B is 1.2:1. Implementation effect

[0049] The products from Examples 1-3 and the comparative example were coated onto the polyimide composite material of the radome. The dry film thickness of the high-temperature resistant elastic protective coating for the radome was 120μm~150μm. After drying for 7 days or baking at 80℃ for 4 hours, key performance tests were conducted on cross-cut adhesion, peel strength, antistatic properties, abrasion resistance, and temperature resistance. The dry film thickness of the elongation at break and tensile strength was 1mm±0.1mm. The curing process was also drying for 7 days or baking at 80℃ for 6 hours. Specific test results are as follows:

[0050] This disclosure has been described with reference to the foregoing embodiments; however, these embodiments are merely examples for implementing this disclosure. It must be noted that the disclosed embodiments do not limit the scope of this disclosure. On the contrary, any changes and modifications made without departing from the spirit and scope of this disclosure are within the scope of patent protection of this disclosure.

Claims

1. A high temperature resistant elastomeric protective coating for radomes, characterized by: The component A and component B are mixed in a mass ratio of 1.5:1-2:1, wherein the percentage content of NCO in the component B is 5%-7%; the component A is composed of the following components in a mass ratio: Polycarbonate triol 24%-28% High-temperature-resistant inorganic pigment 28%-31% Mica powder 9%-12% Conductive carbon fiber 4%-6% Organic silicon dispersing agent 2%-3.5% Organic silicon leveling agent 0.2%-0.3% Organic silicon defoaming agent 0.4%-0.5% Catalyst A 0.1%-0.2% Mixed solvent A 22%-26% The component B is composed of the following components in a mass ratio: Hydroxyl-terminated organic silicon prepolymer 29%-31% Polycarbonate diol 11%-14% Trimethylolpropane 3%-4% Diisocyanate monomer 30%-33% Catalyst B 0.1%-0.15% Catalyst C 0.1%-0.2% Solvent B 20%-22%.

2. The high temperature resistant elastomeric protective coating for radomes according to claim 1, characterized in that: The polycarbonate triol is at least one of PCP-100L2 of Dow Corning and PB41060 of Wengjiang.

3. The high temperature resistant elastomeric protective coating for radomes according to claim 1, characterized in that: The conductive carbon fiber is at least one of 350 microns, 400 microns and 500 microns in length.

4. The high temperature resistant elastomeric protective coating for radomes according to claim 1, characterized in that: The mica powder is at least one of GA-2, GA-4 and GD-2 in particle size.

5. The high temperature resistant elastomeric protective coating for radomes according to claim 1, characterized in that: The high-temperature-resistant inorganic pigment is at least one of rutile, titanium dioxide, cobalt blue, copper-chromium black and cadmium red; the organic silicon dispersing agent is at least one of Wyncoat®8110A, WynCoat®DIS 8290 and WynCoat®8104S; the organic silicon leveling agent is at least one of BD-3410, BD-3432 and BD-3405; the organic silicon defoaming agent is at least one of BYK-066N and BYK-085; the catalyst A is at least one of dibutyltin dilaurate, monobutyl tin oxide and triethylamine.

6. The high temperature resistant elastomeric protective coating for radomes according to claim 1, characterized in that: The mixed solvent A is at least one of dimethylbenzene, butanone and butyl acetate.

7. The high temperature resistant elastomeric protective coating for radomes according to claim 1, characterized in that: The hydroxyl-terminated organic silicon prepolymer is a mixture of Siwell·Rebon® SR-903 and one of Siwell·Rebon® SR-901 and Siwell·Rebon® SR-902.

8. The high temperature resistant elastomeric protective coating for radomes according to claim 1, characterized in that: The polycarbonate diol is a mixture of one of SYH1000 and SYHP1000 with a molecular weight of 1000 and one of SYHP2000 and SYH2000 with a molecular weight of 2000.

9. The high temperature resistant elastomeric protective coating for radomes according to claim 1, characterized in that: The diisocyanate monomer is at least one of HDI, IPDI and HMDI; the catalyst B is at least one of dibutyltin dilaurate and monobutyl tin oxide; the catalyst C is triethylamine; and the solvent B is at least one of dimethylbenzene, butanone and butyl acetate.

10. A process for the preparation of a high temperature resistant elastomeric protective coating for radomes according to any one of claims 1 to 9, characterized in that, The method comprises the following steps: 1) Preparation of the component A: In the state of stirring, add polycarbonate triols, silicone dispersant, silicone leveling agent, silicone defoamer, catalyst A and mixed solvent A into the cylinder in turn, stir uniformly, then add high temperature resistant inorganic pigment, mica powder, conductive carbon fiber in the state of stirring, stir uniformly, then grind in the basket sand mill for 4h, then test the surface resistance, which is 5MΩ~100MΩ, filter the product, and obtain the component A; 2) In the nitrogen-filled reaction bottle, add hydroxyl-terminated silicone prepolymer, polycarbonate diol, trimethylolpropane and solvent B, heat to 125℃~135℃ to reflux and dehydrate, then discharge the product, which is a solution containing hydroxyl resin, then in another nitrogen-filled reaction bottle, first add diisocyanate monomer and catalyst B, then add the solution containing hydroxyl resin in the form of drop, react at 70℃ for 2h, at 90℃ for 2h, then add catalyst C, and react at 90℃~120℃, when the NCO content is 5%~7%, filter the product, and obtain the component B; 3) Then, mix the component A and component B according to the mass ratio of 1.5:1~2:1, stir uniformly, and discharge the product.

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