Normal-temperature curing ablative-resistant coating and preparation method thereof

Abstract

The application discloses a normal-temperature curing ablation-resistant coating and a preparation method thereof. The coating is composed of three parts of A component, B component and C component. The A component comprises the following raw materials in parts by weight: epoxy resin 20-30 parts, liquid butyronitrile rubber 30-40 parts, ablation-resistant filler 27-50 parts, heat-insulating functional filler 10-20 parts and toluene 200-300 parts; the B component is a curing agent; and the C component is a curing accelerator. The ablation-resistant and heat-insulating coating protection construction under the normal-temperature curing condition is realized by selecting a high-performance polymer-based resin material and adding the ablation-resistant filler and the heat-insulating functional filler. The ablation-resistant coating construction and thermal protection when the ablation-resistant coating of a high-temperature curing system cannot be used for fragile covers and launching racks in a launching system are solved. The coating can be used in military technology and civil use, and can be widely applied to building fire prevention and heat-insulating construction.

Description

Technical Field

[0001] This invention belongs to the field of coating technology, specifically relating to a room-temperature curing ablation-resistant coating and its preparation method. Background Technology

[0002] As tactical missiles achieve longer ranges and higher speeds, the aerodynamic heating generated by friction with the air during flight can easily lead to a decrease in the mechanical properties of the missile casing. Similarly, in spacecraft (such as electronics compartments), aerodynamic heating can cause elevated internal temperatures, potentially damaging delicate instruments (tactical missiles generally require internal casing temperatures below 300°C). Therefore, external protective thermal insulation materials play a crucial role in ensuring the quality of spacecraft.

[0003] During launch, the exhaust plume of tactical missiles causes rapid erosion of the launch equipment. Similarly, the high temperature and high-speed jets of rocket engines during operation cause severe ablation and erosion of the engine compartment. While various ablation-resistant and heat-insulating coating technologies exist both domestically and internationally, they all require high-temperature curing, making application difficult. Furthermore, the increasing use of lightweight equipment and the widespread application of non-metallic materials and polymer-based composites have limited the application of ablation-resistant coatings. Therefore, there is an urgent need for an ablation-resistant and heat-insulating coating that can cure at room temperature.

[0004] With the construction of various high-rise buildings and special industrial plants, and the increasing demand for improved fire resistance and structural fire insulation in fire conditions, traditional fire-retardant coatings face challenges such as difficult application, limited ablation resistance, and a sharp decline in structural strength as temperatures rise. Therefore, high-performance ablation-resistant and heat-insulating coatings are needed for building fire protection and insulation.

[0005] Patent CN103666189B discloses an impact-resistant, high-temperature ablation-resistant, self-lubricating, and wear-resistant coating and its preparation method. This coating consists of a binder, a lubricant / wear-resistant agent, additives, and a mixed solvent. The binder is polyetheretherketone resin; the lubricant / wear-resistant agent is polytetrafluoroethylene, molybdenum disulfide, and graphite; the additives are melamine-cyanurate complex, lead oxide, and rare earth oxides; and the mixed solvent is a mixture of distilled water, ethanol, and butanol. Coatings made with this invention exhibit environmental friendliness, ultra-high load-bearing capacity, good adaptability to lubricating oil media, and excellent properties such as impact resistance, high-temperature ablation resistance, and long service life. They also possess high bonding strength, good flexibility, chemical corrosion resistance, and excellent integrated performance. However, this coating requires high-temperature curing, which is inconvenient for application. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a room-temperature curing ablation-resistant coating and its preparation method.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A room-temperature curing ablation-resistant coating comprises three parts: component A, component B, and component C. Component A includes the following raw materials in parts by weight: 20-30 parts epoxy resin, 30-40 parts liquid nitrile rubber, 27-50 parts ablation-resistant filler, 10-20 parts heat-insulating filler, and 200-300 parts toluene. Component B is a curing agent, and component C is a curing accelerator. The ablation-resistant filler includes high-silica fiber powder, chromium trioxide, aluminum hydroxide powder, and carbon fiber powder. The heat-insulating filler includes fumed silica.

[0009] Preferably, the mass ratio of high silica fiber powder, chromium trioxide, aluminum hydroxide powder, and carbon fiber powder is 5-10:1-5:20-30:1-5.

[0010] Preferably, the ablation-resistant filler further includes liquid nitrile rubber-modified graphene oxide in the same mass as the high-silica fiber powder.

[0011] More preferably, the liquid nitrile rubber modified graphene oxide is prepared by the following method: first, graphene oxide is modified with γ-glycidyl etheroxypropyltrimethoxysilane to obtain modified graphene oxide; then, the modified graphene oxide is mixed and reacted with amino-terminated liquid nitrile rubber to obtain the final product.

[0012] A further preferred method for modification is as follows: γ-glycidyl etheroxypropyltrimethoxysilane and anhydrous ethanol are mixed evenly at a mass ratio of 1:2 to 3, then graphene oxide is added, and the mixture is stirred and reacted at 40 to 50°C for 5 to 7 hours. The solvent is then removed by rotary evaporation to obtain modified graphene oxide; wherein the mass ratio of graphene oxide to γ-glycidyl etheroxypropyltrimethoxysilane is 1:0.5 to 0.7.

[0013] A further preferred method for the reaction of modified graphene oxide with amino-terminated liquid nitrile rubber is as follows: the modified graphene oxide is ultrasonically dispersed in ethyl acetate, the amino-terminated liquid nitrile rubber is added, the mixture is ultrasonically oscillated at 300-400W for 20-30 minutes, stirred at 38-40℃ for 60-70 minutes, the precipitate is collected by centrifugation, washed with ethyl acetate, and dried to obtain the final product; wherein the mass ratio of modified graphene oxide, ethyl acetate, and amino-terminated liquid nitrile rubber is 1:25-30:5-6.

[0014] Preferably, the heat-insulating filler further includes zirconium dioxide / zinc oxide hollow microspheres, specifically obtained by mixing fumed silica with zirconium dioxide / zinc oxide hollow microspheres by equal mass.

[0015] More preferably, the zirconium dioxide / zinc oxide hollow microspheres are prepared by the following method: zirconium nitrate pentahydrate, zinc nitrate hexahydrate, and glucose are added to deionized water in a molar ratio of 1:2-3:7-9, stirred until completely dissolved, and subjected to hydrothermal reaction at 160-180°C for 60-80 minutes. The precipitate is collected by centrifugation, washed with water, dried, and calcined at 550-650°C for 2-3 hours to obtain the product; wherein the amount of deionized water is 8-10 times the total mass of zirconium nitrate pentahydrate, zinc nitrate hexahydrate, and glucose.

[0016] Preferably, the curing agent is epoxy resin 593 curing agent (diethylenetriamine and butyl glycidyl ether adduct); the curing accelerator is obtained by mixing dibutyltin dilaurate and 1-benzyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt in a mass ratio of 1:0.2-0.3.

[0017] Preferably, the mass ratio of component A, component B, and component C is 90–110:5–10:1–5.

[0018] The specific steps of the aforementioned method for preparing a room-temperature curing ablation-resistant coating are as follows:

[0019] S1. First, according to the formula composition, ultrasonically disperse the ablation-resistant filler and the heat-insulating filler in half of the formula amount of toluene to obtain the filler dispersion; then ultrasonically disperse the epoxy resin and liquid nitrile rubber in the remaining formula amount of toluene to obtain the resin-rubber mixture; then, under stirring conditions, uniformly and slowly add the filler dispersion to the resin-rubber mixture, perform ultrasonic oscillation treatment under pulsed magnetic field conditions, grind, and obtain component A.

[0020] S2. The curing agent is component B; the curing accelerator is component C.

[0021] Preferably, in step S1, the feeding time of the filler dispersion is 30 to 40 minutes.

[0022] Preferably, in step S1, the pulse magnetic field conditions are: frequency 20-30Hz, current 40-50A, and pulse magnetic field current duty cycle 15-20%; the ultrasonic oscillation treatment conditions are: 400-500W ultrasonic oscillation treatment for 20-30 minutes.

[0023] Preferably, in step S1, a three-roll mill is used for grinding. First, the mill is ground 2 to 3 times with a roller gap of 0.5 to 1 mm, and then it is ground 4 to 5 times with a roller gap of 0.05 to 0.1 mm.

[0024] The aforementioned method for using a room-temperature curing ablation-resistant coating involves mixing components A, B, and C evenly, allowing it to stand for 5–10 minutes, and then spraying or brushing it onto a clean substrate surface. The coating is then cured for 20–24 hours at a temperature of 18–25°C and a relative humidity of 65%.

[0025] Preferably, the matrix material is metal or glass fiber.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] This invention provides a room-temperature curing ablation-resistant coating and its preparation method, comprising three parts: component A, component B, and component C. Component A includes the following raw materials by weight: 20-30 parts epoxy resin, 30-40 parts liquid nitrile rubber, 27-50 parts ablation-resistant filler, 10-20 parts thermal insulation filler, and 200-300 parts toluene. Component B is a curing agent, and component C is a curing accelerator. This invention achieves ablation-resistant and thermal insulation coating protection for equipment under room-temperature curing conditions by selecting high-performance polymer-based resin materials and adding ablation-resistant and thermal insulation fillers. It solves the problem of ablation-resistant coating construction and thermal protection for fragile covers and launch pads in launch systems where high-temperature curing ablation-resistant coatings cannot be used. This coating can be applied to both military and civilian uses and can be widely used in building fireproofing and thermal insulation construction.

[0028] This invention has the following advantages:

[0029] 1. Achieved room temperature curing: By selecting a specific room temperature curing resin system and corresponding curing agent, the curing agent is epoxy resin 593 curing agent, and the curing accelerator is a mixture of dibutyltin dilaurate and 1-benzyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, which promotes curing and allows the coating to undergo a full cross-linking reaction at an ambient temperature of 18-25℃ to form a three-dimensional network structure. No external heating equipment is required, which greatly expands the application scenarios.

[0030] 2. Excellent application adaptability: The three-component packaging ensures storage stability and rapid curing upon use. The viscosity can be adjusted using the solvent to suit various complex application conditions, including on-site and outdoor environments, depending on the application requirements (e.g., brushing, spraying).

[0031] 3. In this invention, the ablation-resistant filler includes high-silica fiber powder, chromium trioxide, aluminum hydroxide powder, and carbon fiber powder; the thermal insulation filler includes fumed silica. The thermal insulation filler in the formulation provides reliable thermal insulation, improves the mechanical strength and toughness of the coating, prevents cracking during the curing process or under thermal shock, and ensures the reliability of the protection.

[0032] The present invention further introduces liquid nitrile rubber modified graphene oxide as part of the ablation-resistant filler, and introduces zirconium dioxide / zinc oxide hollow microspheres as part of the thermal insulation functional filler. The synergistic effect of these two components helps to further improve the ablation resistance and thermal insulation performance. Detailed Implementation

[0033] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0034] Epoxy resin, brand name E-44, purchased from Shandong Duoju Chemical Co., Ltd.

[0035] Liquid nitrile rubber, grade SH-820, was purchased from Dongguan Shenghao Plastic Raw Materials Co., Ltd.

[0036] Amino-terminated liquid nitrile butadiene rubber, grade TL55, purchased from Jiangsu Jufeng Chemical Technology Co., Ltd.

[0037] High-silica fiber powder (silane modified, particle size 300 mesh), purchased from Donghai County Fucai Mineral Products Co., Ltd.

[0038] Chromium trioxide, 200 mesh particle size, purchased from Sichuan Xinjinchun Metal Materials Co., Ltd.

[0039] Aluminum hydroxide powder, 200 mesh particle size, purchased from Shandong Anquan Chemical Technology Co., Ltd.

[0040] Carbon fiber powder, 300 mesh, purchased from Yancheng Xiang Sheng Carbon Fiber Technology Co., Ltd.

[0041] Fumed silica, 300 mesh, purchased from Lingshou County Kaiqi Mineral Products Processing Plant;

[0042] 1-Benzyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt was purchased from Wuhan Smike Biotechnology Co., Ltd.

[0043] Example 1

[0044] A room-temperature curing ablation-resistant coating comprises three parts: component A, component B, and component C. Component A includes the following raw materials: 2 kg of epoxy resin, 3 kg of liquid nitrile rubber, 2.7 kg of ablation-resistant filler, 1 kg of heat-insulating filler, and 20 kg of toluene. Component B is a curing agent, and component C is a curing accelerator. The ablation-resistant filler is obtained by mixing high-silica fiber powder, chromium trioxide, aluminum hydroxide powder, carbon fiber powder, and liquid nitrile rubber-modified graphene oxide in a mass ratio of 5:1:20:1:5. The heat-insulating filler is obtained by mixing fumed silica with zirconium dioxide / zinc oxide hollow microspheres by equal mass.

[0045] The liquid nitrile rubber modified graphene oxide is prepared by the following method: first, graphene oxide is modified with γ-glycidyl etheroxypropyltrimethoxysilane to obtain modified graphene oxide; then, the modified graphene oxide is mixed and reacted with amino-terminated liquid nitrile rubber to obtain the final product.

[0046] The specific method of modification is as follows: γ-glycidoxypropyltrimethoxysilane and anhydrous ethanol are mixed evenly at a mass ratio of 1:2, then graphene oxide (prepared by a modified Hummers method) is added, and the mixture is stirred and reacted at 40°C for 5 hours. The solvent is removed by rotary evaporation to obtain modified graphene oxide; wherein the mass ratio of graphene oxide to γ-glycidoxypropyltrimethoxysilane is 1:0.5.

[0047] The specific method for the mixed reaction of modified graphene oxide and amino-terminated liquid nitrile rubber is as follows: the modified graphene oxide is ultrasonically dispersed in ethyl acetate, the amino-terminated liquid nitrile rubber is added, the mixture is ultrasonically oscillated at 300W for 20 minutes, stirred at 38℃ for 60 minutes, the precipitate is collected by centrifugation, washed with ethyl acetate, and dried to obtain the final product; wherein, the mass ratio of modified graphene oxide, ethyl acetate, and amino-terminated liquid nitrile rubber is 1:25:5.

[0048] The zirconium dioxide / zinc oxide hollow microspheres were prepared by the following method: zirconium nitrate pentahydrate, zinc nitrate hexahydrate, and glucose were added to deionized water in a molar ratio of 1:2:7, stirred until completely dissolved, hydrothermally reacted at 160°C for 60 minutes, the precipitate was collected by centrifugation, washed with water, dried, and calcined at 550°C for 2 hours to obtain the product; wherein, the amount of deionized water used was 8 times the total mass of zirconium nitrate pentahydrate, zinc nitrate hexahydrate, and glucose.

[0049] The curing agent is epoxy resin 593 curing agent (diethylenetriamine and butyl glycidyl ether adduct); the curing accelerator is obtained by mixing dibutyltin dilaurate and 1-benzyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt in a mass ratio of 1:0.2.

[0050] The mass ratio of component A, component B, and component C is 90:5:1.

[0051] The specific steps of the aforementioned method for preparing a room-temperature curing ablation-resistant coating are as follows:

[0052] S1. First, according to the formula composition, ultrasonically disperse the ablation-resistant filler and the heat-insulating filler in half of the formula amount of toluene to obtain the filler dispersion; then ultrasonically disperse the epoxy resin and liquid nitrile rubber in the remaining formula amount of toluene to obtain the resin-rubber mixture; then, under stirring conditions, uniformly and slowly add the filler dispersion to the resin-rubber mixture, perform ultrasonic oscillation treatment under pulsed magnetic field conditions, grind, and obtain component A.

[0053] S2. The curing agent is component B; the curing accelerator is component C.

[0054] In step S1, the feeding time of the filler dispersion is 30 minutes.

[0055] In step S1, the pulse magnetic field conditions are: frequency 20Hz, current 40A, pulse magnetic field current duty cycle 15%; the ultrasonic oscillation treatment conditions are: 400W ultrasonic oscillation treatment for 20 minutes.

[0056] In step S1, a three-roll mill is used for grinding. First, the mill is ground twice with a roller gap of 0.5 mm, and then it is ground four times with a roller gap of 0.05 mm.

[0057] Example 2

[0058] A room-temperature curing ablation-resistant coating comprises three parts: component A, component B, and component C. Component A includes the following raw materials: 3 kg of epoxy resin, 4 kg of liquid nitrile rubber, 5 kg of ablation-resistant filler, 2 kg of heat-insulating filler, and 30 kg of toluene. Component B is a curing agent, and component C is a curing accelerator. The ablation-resistant filler is obtained by mixing high-silica fiber powder, chromium trioxide, aluminum hydroxide powder, carbon fiber powder, and liquid nitrile rubber-modified graphene oxide in a mass ratio of 10:5:30:5:10. The heat-insulating filler is obtained by mixing fumed silica with zirconium dioxide / zinc oxide hollow microspheres by equal mass.

[0059] The liquid nitrile rubber modified graphene oxide is prepared by the following method: first, graphene oxide is modified with γ-glycidyl etheroxypropyltrimethoxysilane to obtain modified graphene oxide; then, the modified graphene oxide is mixed and reacted with amino-terminated liquid nitrile rubber to obtain the final product.

[0060] The specific method of modification is as follows: γ-glycidoxypropyltrimethoxysilane and anhydrous ethanol are mixed evenly at a mass ratio of 1:3, then graphene oxide (prepared by the modified Hummers method) is added, and the mixture is stirred and reacted at 50°C for 7 hours. The solvent is removed by rotary evaporation to obtain modified graphene oxide; wherein the mass ratio of graphene oxide to γ-glycidoxypropyltrimethoxysilane is 1:0.7.

[0061] The specific method for the mixed reaction of modified graphene oxide and amino-terminated liquid nitrile rubber is as follows: the modified graphene oxide is ultrasonically dispersed in ethyl acetate, the amino-terminated liquid nitrile rubber is added, the mixture is ultrasonically oscillated at 400W for 30 minutes, stirred at 40℃ for 70 minutes, the precipitate is collected by centrifugation, washed with ethyl acetate, and dried to obtain the final product; wherein, the mass ratio of modified graphene oxide, ethyl acetate, and amino-terminated liquid nitrile rubber is 1:30:6.

[0062] The zirconium dioxide / zinc oxide hollow microspheres were prepared by the following method: zirconium nitrate pentahydrate, zinc nitrate hexahydrate, and glucose were added to deionized water at a molar ratio of 1:3:9, stirred until completely dissolved, hydrothermally reacted at 180°C for 80 minutes, the precipitate was collected by centrifugation, washed with water, dried, and calcined at 650°C for 3 hours to obtain the product; wherein, the amount of deionized water used was 10 times the total mass of zirconium nitrate pentahydrate, zinc nitrate hexahydrate, and glucose.

[0063] The curing agent is epoxy resin 593 curing agent (diethylenetriamine and butyl glycidyl ether adduct); the curing accelerator is obtained by mixing dibutyltin dilaurate and 1-benzyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt in a mass ratio of 1:0.3.

[0064] The mass ratio of component A, component B, and component C is 110:10:5.

[0065] The specific steps of the aforementioned method for preparing a room-temperature curing ablation-resistant coating are as follows:

[0066] S1. First, according to the formula composition, ultrasonically disperse the ablation-resistant filler and the heat-insulating filler in half of the formula amount of toluene to obtain the filler dispersion; then ultrasonically disperse the epoxy resin and liquid nitrile rubber in the remaining formula amount of toluene to obtain the resin-rubber mixture; then, under stirring conditions, uniformly and slowly add the filler dispersion to the resin-rubber mixture, perform ultrasonic oscillation treatment under pulsed magnetic field conditions, grind, and obtain component A.

[0067] S2. The curing agent is component B; the curing accelerator is component C.

[0068] In step S1, the feeding time of the filler dispersion is 40 minutes.

[0069] In step S1, the pulse magnetic field conditions are: frequency 30Hz, current 50A, pulse magnetic field current duty cycle 20%; the ultrasonic oscillation treatment conditions are: 500W ultrasonic oscillation treatment for 30 minutes.

[0070] In step S1, a three-roll mill is used for grinding. First, the mill is ground 3 times with a roller gap of 1 mm, and then it is ground 5 times with a roller gap of 0.1 mm.

[0071] Example 3

[0072] A room-temperature curing ablation-resistant coating comprises three parts: component A, component B, and component C. Component A includes the following raw materials: 2.5 kg of epoxy resin, 3.5 kg of liquid nitrile rubber, 4.5 kg of ablation-resistant filler, 1.5 kg of heat-insulating filler, and 25 kg of toluene. Component B is a curing agent, and component C is a curing accelerator. The ablation-resistant filler is obtained by mixing high-silica fiber powder, chromium trioxide, aluminum hydroxide powder, carbon fiber powder, and liquid nitrile rubber-modified graphene oxide in a mass ratio of 8:4:25:3:7. The heat-insulating filler is obtained by mixing fumed silica with zirconium dioxide / zinc oxide hollow microspheres by equal mass.

[0073] The liquid nitrile rubber modified graphene oxide is prepared by the following method: first, graphene oxide is modified with γ-glycidyl etheroxypropyltrimethoxysilane to obtain modified graphene oxide; then, the modified graphene oxide is mixed and reacted with amino-terminated liquid nitrile rubber to obtain the final product.

[0074] The specific method of modification is as follows: γ-glycidoxypropyltrimethoxysilane and anhydrous ethanol are mixed evenly at a mass ratio of 1:2.5, then graphene oxide (prepared by a modified Hummers method) is added, and the mixture is stirred and reacted at 45°C for 6 hours. The solvent is removed by rotary evaporation to obtain modified graphene oxide; wherein the mass ratio of graphene oxide to γ-glycidoxypropyltrimethoxysilane is 1:0.6.

[0075] The specific method for the mixed reaction of modified graphene oxide and amino-terminated liquid nitrile rubber is as follows: the modified graphene oxide is ultrasonically dispersed in ethyl acetate, the amino-terminated liquid nitrile rubber is added, the mixture is ultrasonically oscillated at 400W for 25 minutes, stirred at 39℃ for 65 minutes, the precipitate is collected by centrifugation, washed with ethyl acetate, and dried to obtain the final product; wherein, the mass ratio of modified graphene oxide, ethyl acetate, and amino-terminated liquid nitrile rubber is 1:28:5.5.

[0076] The zirconium dioxide / zinc oxide hollow microspheres were prepared by the following method: zirconium nitrate pentahydrate, zinc nitrate hexahydrate, and glucose were added to deionized water at a molar ratio of 1:2.5:8, stirred until completely dissolved, and subjected to hydrothermal reaction at 170°C for 70 minutes. The precipitate was collected by centrifugation, washed with water, dried, and calcined at 600°C for 2 hours to obtain the product. The amount of deionized water used was 9 times the total mass of zirconium nitrate pentahydrate, zinc nitrate hexahydrate, and glucose.

[0077] The curing agent is epoxy resin 593 curing agent (diethylenetriamine and butyl glycidyl ether adduct); the curing accelerator is obtained by mixing dibutyltin dilaurate and 1-benzyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt in a mass ratio of 1:0.25.

[0078] The mass ratio of component A, component B, and component C is 100:8:3.

[0079] The specific steps of the aforementioned method for preparing a room-temperature curing ablation-resistant coating are as follows:

[0080] S1. First, according to the formula composition, ultrasonically disperse the ablation-resistant filler and the heat-insulating filler in half of the formula amount of toluene to obtain the filler dispersion; then ultrasonically disperse the epoxy resin and liquid nitrile rubber in the remaining formula amount of toluene to obtain the resin-rubber mixture; then, under stirring conditions, uniformly and slowly add the filler dispersion to the resin-rubber mixture, perform ultrasonic oscillation treatment under pulsed magnetic field conditions, grind, and obtain component A.

[0081] S2. The curing agent is component B; the curing accelerator is component C.

[0082] In step S1, the feeding time of the filler dispersion is 35 minutes.

[0083] In step S1, the pulse magnetic field conditions are: frequency 30Hz, current 45A, pulse magnetic field current duty cycle 17%; the ultrasonic oscillation treatment conditions are: 500W ultrasonic oscillation treatment for 25 minutes.

[0084] In step S1, a three-roll mill is used for grinding. First, the mill is ground 3 times with a roller gap of 0.7 mm, and then it is ground 5 times with a roller gap of 0.08 mm.

[0085] Comparative Example 1

[0086] Liquid nitrile rubber modified graphene oxide is omitted;

[0087] The rest is the same as in Example 1.

[0088] Comparative Example 2

[0089] Zirconia / zinc oxide hollow microspheres are omitted;

[0090] The rest is the same as in Example 1.

[0091] Comparative Example 3

[0092] The curing accelerator omits 1-benzyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt;

[0093] The rest is the same as in Example 1.

[0094] Comparative Example 4

[0095] A coating comprises three parts: component A, component B, and component C. Component A includes the following raw materials: 2 kg of epoxy resin, 3 kg of liquid nitrile rubber, 2.7 kg of ablation-resistant filler, 1 kg of thermal insulation filler, and 20 kg of toluene. Component B is a curing agent, and component C is a curing accelerator. The ablation-resistant filler is obtained by mixing high-silica fiber powder, chromium trioxide, aluminum hydroxide powder, carbon fiber powder, and liquid nitrile rubber-modified graphene oxide in a mass ratio of 5:1:20:1:5. The thermal insulation filler is obtained by mixing fumed silica with zirconium dioxide / zinc oxide hollow microspheres by equal mass.

[0096] The liquid nitrile rubber modified graphene oxide is prepared by the following method: first, graphene oxide is modified with γ-glycidyl etheroxypropyltrimethoxysilane to obtain modified graphene oxide; then, the modified graphene oxide is mixed and reacted with amino-terminated liquid nitrile rubber to obtain the final product.

[0097] The specific method of modification is as follows: γ-glycidoxypropyltrimethoxysilane and anhydrous ethanol are mixed evenly at a mass ratio of 1:2, then graphene oxide (prepared by a modified Hummers method) is added, and the mixture is stirred and reacted at 40°C for 5 hours. The solvent is removed by rotary evaporation to obtain modified graphene oxide; wherein the mass ratio of graphene oxide to γ-glycidoxypropyltrimethoxysilane is 1:0.5.

[0098] The specific method for the mixed reaction of modified graphene oxide and amino-terminated liquid nitrile rubber is as follows: the modified graphene oxide is ultrasonically dispersed in ethyl acetate, the amino-terminated liquid nitrile rubber is added, the mixture is ultrasonically oscillated at 300W for 20 minutes, stirred at 38℃ for 60 minutes, the precipitate is collected by centrifugation, washed with ethyl acetate, and dried to obtain the final product; wherein, the mass ratio of modified graphene oxide, ethyl acetate, and amino-terminated liquid nitrile rubber is 1:25:5.

[0099] The zirconium dioxide / zinc oxide hollow microspheres were prepared by the following method: zirconium nitrate pentahydrate, zinc nitrate hexahydrate, and glucose were added to deionized water in a molar ratio of 1:2:7, stirred until completely dissolved, hydrothermally reacted at 160°C for 60 minutes, the precipitate was collected by centrifugation, washed with water, dried, and calcined at 550°C for 2 hours to obtain the product; wherein, the amount of deionized water used was 8 times the total mass of zirconium nitrate pentahydrate, zinc nitrate hexahydrate, and glucose.

[0100] The curing agent is epoxy resin 593 curing agent (diethylenetriamine and butyl glycidyl ether adduct); the curing accelerator is obtained by mixing dibutyltin dilaurate and 1-benzyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt in a mass ratio of 1:0.2.

[0101] The mass ratio of component A, component B, and component C is 90:5:1.

[0102] The specific steps of the aforementioned method for preparing a coating are as follows:

[0103] S1. First, according to the formula composition, ultrasonically disperse the ablation-resistant filler and the heat-insulating filler in toluene, then add epoxy resin and liquid nitrile rubber, ultrasonically vibrate and grind to obtain component A;

[0104] S2. The curing agent is component B; the curing accelerator is component C.

[0105] In step S1, the conditions for ultrasonic oscillation treatment are: 400W ultrasonic oscillation treatment for 20 minutes.

[0106] In step S1, a three-roll mill is used for grinding. First, the mill is ground twice with a roller gap of 0.5 mm, and then it is ground four times with a roller gap of 0.05 mm.

[0107] Test case

[0108] The coatings obtained in Examples 1-3 and Comparative Examples 1-4 were brushed onto the surface of a stainless steel substrate. The specific method was as follows: Components A, B, and C were mixed evenly, left to stand for 5-10 minutes, and then brushed onto the cleaned surface of a stainless steel substrate (100mm×50mm×1mm). The mixture was cured at a temperature of 25℃ and a relative humidity of 65% to form a coating with a thickness of 0.2mm, thus obtaining a sample.

[0109] Refer to GB / T1728-2020 "Determination of Drying Time of Paint Film and Putty Film" to determine the surface drying time and actual drying time.

[0110] Further tests were conducted on the coating's ablation resistance and thermal insulation properties:

[0111] Ablation resistance: An oxy-acetylene flame ablation test was conducted to detect the linear ablation rate. The test duration was 10 seconds. Specific test conditions are as follows:

[0112] Oxygen, pressure 0.30 MPa, flow rate 14.2 L / min;

[0113] Acetylene, pressure 0.09 MPa, flow rate 10.5 L / min;

[0114] Heat flux density 1000kW / m 2 ;

[0115] Nozzle diameter 2mm;

[0116] The ablation distance is 50mm.

[0117] Thermal insulation performance test method: Place the sample in a sealed box and irradiate the coating surface of the sample with a 250W incandescent lamp for 5 hours. Use a temperature sensor and temperature display to test and display the temperature of the bottom of the sample. The lower the temperature of the bottom of the sample, the better the thermal insulation performance.

[0118] The test results are shown in Table 1.

[0119] Table 1. Coating performance test

[0120]

[0121] As shown in Table 1, the coatings obtained in Examples 1 to 3 can be cured at room temperature and have excellent ablation resistance and thermal insulation properties.

[0122] The curing accelerator 1-benzyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt in Comparative Example 3 showed a significantly longer curing time and also affected the coating's ablation resistance and thermal insulation properties.

[0123] Comparative Example 1 omitted liquid nitrile rubber modified graphene oxide, Comparative Example 2 omitted zirconium dioxide / zinc oxide hollow microspheres, and Comparative Example 4 used a direct mixing method when preparing component A, resulting in significantly worse ablation resistance and thermal insulation performance. This indicates that the ablation-resistant filler, thermal insulation filler, and specific mixing method of the present invention work synergistically to improve coating performance.

[0124] The present invention has been illustrated through the above embodiments, but the present invention is not limited to the above embodiments, that is, it does not mean that the present invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of individual raw materials in the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A room temperature curing ablative resistant coating characterized in that, It is composed of three parts of A component, B component and C component: the A component includes the following raw materials by weight: epoxy resin 20-30 parts, liquid butyronitrile rubber 30-40 parts, ablative filler 27-50 parts, heat insulation functional filler 10-20 parts, toluene 200-300 parts; the B component is a curing agent; the C component is a curing accelerator; wherein the ablative filler includes high silicon fiber powder, chromium trioxide, aluminum hydroxide powder, carbon fiber powder; the heat insulation functional filler includes fumed silica; The ablative filler also includes liquid butyronitrile rubber modified graphene oxide with high silicon fiber powder; the liquid butyronitrile rubber modified graphene oxide is prepared by the following method: first, the graphene oxide is modified by gamma-glycidyl ether oxypropyl trimethoxysilane to obtain modified graphene oxide; then the modified graphene oxide is mixed and reacted with the amino-terminated liquid butyronitrile rubber to obtain the liquid butyronitrile rubber modified graphene oxide; The heat insulation functional filler also includes zirconium dioxide / zinc oxide hollow microspheres, and the heat insulation functional filler is obtained by mixing fumed silica and zirconium dioxide / zinc oxide hollow microspheres in equal quality. The curing accelerator is a mixture of dibutyltin dilaurate and 1-benzyl-3-methylimidazole bis(trifluoromethanesulfonyl) imidate salt in a mass ratio of 1:0.2-0.

3. The preparation method of the one kind of normal temperature curing ablative coating, the specific steps are as follows: S1. According to the formula composition, the ablative filler and the heat insulation functional filler are ultrasonically dispersed in half of the formula amount of toluene to obtain a filler dispersion liquid; then the epoxy resin and the liquid butyronitrile rubber are ultrasonically dispersed in the remaining formula amount of toluene to obtain a resin rubber mixture; then the filler dispersion liquid is slowly and uniformly added to the resin rubber mixture under stirring conditions, and ultrasonic oscillation treatment is carried out under the condition of pulse magnetic field, grinding to obtain the A component; S2. The curing agent is the B component; the curing accelerator is the C component.

2. The ambient-curable ablative-resistant coating according to claim 1, characterized in that, The mass ratio of high silicon fiber powder, chromium trioxide, aluminum hydroxide powder, and carbon fiber powder is 5-10:1-5:20-30:1-5.

3. The ambient-curable ablative-resistant coating of claim 1, wherein, The curing agent is epoxy resin 593 curing agent.

4. The ambient-curable ablative-resistant coating of claim 1, wherein, The mass ratio of the A component, the B component, and the C component is 90-110:5-10:1-5.

5. The process for preparing a room temperature vulcanizable ablative resistant coating according to any one of claims 1 to 4, characterized in that, The specific steps are as follows: S1. According to the formula composition, the ablative filler and the heat insulation functional filler are ultrasonically dispersed in half of the formula amount of toluene to obtain a filler dispersion liquid; then the epoxy resin and the liquid butyronitrile rubber are ultrasonically dispersed in the remaining formula amount of toluene to obtain a resin rubber mixture; then the filler dispersion liquid is slowly and uniformly added to the resin rubber mixture under stirring conditions, and ultrasonic oscillation treatment is carried out under the condition of pulse magnetic field, grinding to obtain the A component; S2. The curing agent is the B component; the curing accelerator is the C component.

6. The preparation method according to claim 5, characterized in that, In step S1, the pulse magnetic field condition is: frequency 20-30 Hz, current 40-50 A, pulse magnetic field current duty cycle 15-20%; the ultrasonic oscillation treatment condition is: 400-500 W ultrasonic oscillation treatment for 20-30 minutes.

7. The preparation method according to claim 5, characterized in that, In step S1, the three-roller grinder is used for grinding, first with a roller gap of 0.5-1 mm for 2-3 times, and then with a roller gap of 0.05-0.1 mm for 4-5 times.

8. The use of the ambient-curable ablative-resistant coating according to any one of claims 1 to 4, characterized in that The A component, the B component and the C component are mixed uniformly, and are left for 5-10 minutes. The mixture is sprayed or brushed on the surface of a cleaned substrate. The mixture is cured at a temperature of 18-25°C and a relative humidity of 65% for 20-24 hours.

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