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

Abstract

The invention discloses a normal-temperature curing ablation-resistant coating and a preparation method thereof, the normal-temperature curing ablation-resistant coating comprises a component A, a component B and a component C, the component A comprises the following raw materials by weight: 20-30 parts of epoxy resin, 30-40 parts of liquid nitrile rubber, 27-50 parts of an ablation-resistant filler, 10-20 parts of a heat-insulating functional filler, and 200-300 parts of toluene; the component B is a curing agent; and the component C is a curing accelerator. By selecting the high-performance polymer-based resin material and adding the ablation-resistant filler and the heat-insulating functional filler, the ablation-resistant and heat-insulating coating protection construction of the equipment under the normal-temperature curing condition is realized; the problems of ablation-resistant coating construction and thermal protection when a fragile cover, a launcher and the like in a launching system cannot use a high-temperature curing system ablation-resistant coating are solved. The coating can realize military technology and civil use, and can be widely applied to fire prevention and heat insulation construction of buildings.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of paint, and particularly relates to a normal-temperature curing ablation-resistant paint and a preparation method thereof. BACKGROUND

[0002] With the longer range and faster flight speed of tactical missiles, the tactical missiles are prone to aerodynamic heating due to air friction during flight, which easily leads to the decline of the mechanical properties of the missile shell. Under the condition of aerodynamic heating of spacecraft (such as electronic cabin), the temperature in the cabin rises, which easily leads to the damage of the precision instruments in the cabin (the shell inside of the tactical missile is generally required to be below 300 DEG C). Therefore, the outer protective thermal insulation material plays a very important role in the quality guarantee of aerospace vehicles.

[0003] When the tactical missile is launched, the tail flame causes rapid scouring to the launching equipment, and the high-temperature and high-speed flame flow during the operation of the rocket engine causes sharp ablation and scouring to the engine cabin body, etc. Although there are various ablation-resistant and thermal insulation coating technologies at home and abroad, they are all cured at high temperature, which is inconvenient for construction. With the development of lightweight equipment, the application of a large number of non-metallic materials and polymer matrix composites causes the limitation of the application of ablation-resistant coating. There is an urgent need for an ablation-resistant and thermal insulation coating which can be cured at room temperature.

[0004] With the construction of various high-rise buildings and special industrial plants, the improvement of the fireproofing and fire-resistant and thermal insulation performance of building structures under fire conditions, the traditional fireproofing coating has the problems of great construction difficulty, limited ablation-resistant performance, and sharp decline of the building structure strength with the increase of temperature. Therefore, an ablation-resistant and thermal insulation coating with superior performance is also needed to be applied to building fireproofing and thermal insulation.

[0005] Patent CN103666189B discloses an impact-resistant high-temperature ablation-resistant self-lubricating wear-resistant coating and a preparation method thereof. The coating is composed of a binder, a lubricating wear-resistant agent, an additive, and a mixed solvent. The binder is polyether ether ketone resin, the lubricating wear-resistant agent is polytetrafluoroethylene, molybdenum disulfide and graphite, the additive is triazine cyanamide tricyanate complex, lead oxide and rare earth oxide, and the mixed solvent is a mixture of distilled water, ethanol and butanol. The coating made of the coating has the advantages of environmental friendliness, super high bearing, good adaptability to lubricating oil medium, excellent properties such as impact resistance, high-temperature ablation resistance and long service life, and excellent functions such as high bonding strength, good flexibility, chemical corrosion resistance and medium resistance. However, the coating needs to be cured at high temperature, which is inconvenient for construction. SUMMARY

[0006] In view of the deficiencies in the prior art, the present application aims to provide a normal-temperature curing ablation-resistant paint and a preparation method thereof.

[0007] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions: The room temperature curing ablative resistant coating is composed of three parts of A component, B component and C component: the A component includes the following raw materials in parts by weight: epoxy resin 20-30 parts, liquid butyl nitrile rubber 30-40 parts, ablative resistant 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 resistant filler includes high silicon fiber powder, chromium (III) oxide, aluminum hydroxide powder, carbon fiber powder; the heat insulation functional filler includes fumed silica.

[0008] Preferably, the mass ratio of high silicon fiber powder, chromium (III) oxide, aluminum hydroxide powder, carbon fiber powder is 5-10: 1-5: 20-30: 1-5.

[0009] Preferably, the ablative resistant filler further includes liquid butyl nitrile rubber modified graphene oxide in equal mass with the high silicon fiber powder.

[0010] Further preferably, the liquid butyl nitrile rubber modified graphene oxide is prepared by the following method: first, the graphene oxide is modified by γ-glycidoxypropyltrimethoxysilane to obtain modified graphene oxide; then the modified graphene oxide is mixed and reacted with the amino-terminated liquid butyl nitrile rubber.

[0011] More preferably, the specific method of modification is: γ-glycidoxypropyltrimethoxysilane is mixed with anhydrous ethanol in a mass ratio of 1:2-3, then graphene oxide is added, and stirred at 40-50℃ for 5-7 hours, and the solvent is removed by rotary evaporation to obtain modified graphene oxide; wherein the mass ratio of graphene oxide to γ-glycidoxypropyltrimethoxysilane is 1:0.5-0.7.

[0012] More preferably, the specific method of mixing and reacting the modified graphene oxide with the amino-terminated liquid butyl nitrile rubber is: the modified graphene oxide is ultrasonically dispersed in ethyl acetate, the amino-terminated liquid butyl nitrile rubber is added, and ultrasonic oscillation treatment is carried out at 300-400W for 20-30 minutes, stirring reaction is carried out at 38-40℃ for 60-70 minutes, the precipitate is obtained by centrifugation, washed with ethyl acetate, and dried to obtain the product; wherein the mass ratio of modified graphene oxide, ethyl acetate, and amino-terminated liquid butyl nitrile rubber is 1:25-30:5-6.

[0013] Preferably, the heat insulation functional filler further includes zirconium dioxide / zinc oxide hollow microspheres, which are obtained by mixing fumed silica and zirconium dioxide / zinc oxide hollow microspheres in equal mass.

[0014] Further preferably, the zirconium dioxide / zinc oxide hollow microspheres are prepared by the following method: zirconium nitrate pentahydrate, zinc nitrate hexahydrate and glucose are added into deionized water in a molar ratio of 1:2-3:7-9, stirred until completely dissolved, hydrothermally reacted at 160-180℃ for 60-80 minutes, centrifuged to take the precipitate, washed with water, dried, calcined at 550-650℃ for 2-3 hours, and obtained; wherein the amount of deionized water is 8-10 times the total mass of zirconium nitrate pentahydrate, zinc nitrate hexahydrate and glucose.

[0015] Preferably, the curing agent is epoxy resin 593 curing agent (diethylenetriamine and butyl glycidyl ether adduct); and the curing accelerator is a mixture of dibutyltin dilaurate and 1-benzyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt in a mass ratio of 1:0.2-0.3.

[0016] Preferably, the mass ratio of A component, B component and C component is 90-110:5-10:1-5.

[0017] The preparation method of the aforementioned room temperature curing ablative-resistant coating is as follows: S1. First, according to the formula composition, the ablative-resistant filler and the heat-insulating 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; and then the filler dispersion liquid is uniformly and slowly added to the resin-rubber mixture under stirring conditions, and ultrasonic oscillation treatment is carried out under the condition of a pulsed magnetic field, and grinding is carried out to obtain the A component; S2. The curing agent is used as the B component; and the curing accelerator is used as the C component.

[0018] Preferably, in step S1, the feeding time of the filler dispersion liquid is 30-40 minutes.

[0019] Preferably, in step S1, the pulsed magnetic field condition is: frequency 20-30 Hz, current 40-50 A, and pulse magnetic field current duty cycle 15-20%; and the ultrasonic oscillation treatment condition is: 400-500 W ultrasonic oscillation treatment for 20-30 minutes.

[0020] Preferably, in step S1, a three-roll grinder is used for grinding, and first, the grinding is carried out for 2-3 times with a roll gap of 0.5-1 mm, and then the grinding is carried out for 4-5 times with a roll gap of 0.05-0.1 mm.

[0021] The use method of the aforementioned room temperature curing ablative-resistant coating is as follows: the A component, the B component and the C component are uniformly mixed, and then left to stand for 5-10 minutes; and then the mixture is sprayed or brushed on the surface of a cleaned substrate, and then cured at a temperature of 18-25℃ and a relative humidity of 65% for 20-24 hours.

[0022] Preferably, the base material is metal or glass fiber.

[0023] Compared with the prior art, the present application has the following advantages: The present application provides a normal-temperature curing ablation-resistant coating and a preparation method thereof, which is composed of three parts of A component, B component and C component: the A component includes 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 present application realizes the construction of the equipment ablation-resistant and heat-insulating coating under the normal-temperature curing condition by selecting a high-performance polymer-based resin material and adding the ablation-resistant filler and the heat-insulating functional filler, and solves the ablation-resistant coating construction and thermal protection when the ablation-resistant coating of the high-temperature curing system cannot be used for the fragile cover and the launching rack in the launching system. The coating can be used in military technology and civil use, and can be widely applied to building fire prevention and heat-insulating construction.

[0024] The present application has the following advantages: 1. Normal-temperature curing is realized: by selecting a specific normal-temperature curing resin system and a 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-methylimidazole bis(trifluoromethanesulfonyl) imidazole salt, which promotes curing, so that the coating can occur sufficient crosslinking reaction at an ambient temperature of 18-25 DEG C, and a three-dimensional network structure is formed, without the need of external heating equipment, which greatly expands the application scenarios.

[0025] 2. Good construction adaptability: three-component packaging ensures the storage stability and the characteristics of rapid curing during use. The viscosity can be adjusted by solvent according to the construction requirements (such as brushing and spraying), and the coating is suitable for construction under various complex working conditions such as on-site and outdoor.

[0026] 3. In the present application, the ablation-resistant filler includes high-silicon fiber powder, chromium sesquioxide, aluminum hydroxide powder and carbon fiber powder; and the heat-insulating functional filler includes fumed silica. The heat-insulating filler in the formula provides reliable heat-insulating effect, improves the mechanical strength and toughness of the coating, prevents cracks from being generated during the curing process or thermal shock, and ensures the reliability of the protection.

[0027] The present application further introduces liquid butyronitrile rubber modified graphene oxide as part of the ablation-resistant filler, and zirconium dioxide / zinc oxide hollow microspheres as part of the heat-insulating functional filler, and the synergistic effect of the two components helps to further improve the ablation-resistant performance and heat-insulating performance. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0029] Epoxy resin, brand E-44, purchased from Shandong Duoli Chemical Co., Ltd.; Liquid nitrile rubber, brand SH-820, purchased from Dongguan Shenghao Plastic Raw Material Co., Ltd.; Amino-terminated liquid nitrile rubber, brand TL55, purchased from Jiangsu Jufeng Chemical Technology Co., Ltd.; High-silica fiber powder (silane modified, particle size 300 mesh), purchased from Donghai County Fucai Mineral Products Co., Ltd.; Chromium trioxide, particle size 200 mesh, purchased from Sichuan Xinjinxun Metal Material Co., Ltd.; Aluminum hydroxide powder, particle size 200 mesh, purchased from Shandong Anquan Chemical Technology Co., Ltd.; Carbon fiber powder, particle size 300 mesh, purchased from Yancheng Xiangsheng Carbon Fiber Technology Co., Ltd.; Fumed silica, particle size 300 mesh, purchased from Kaixi Mineral Product Processing Factory in Lingshou County; 1-benzyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, purchased from Wuhan Smac Biotech Co., Ltd.

[0030] Example 1 A normal-temperature curing ablative-resistant coating is composed of three parts of A component, B component and C component: the A component comprises the following raw materials: epoxy resin 2 kg, liquid nitrile rubber 3 kg, ablative-resistant filler 2.7 kg, heat-insulating functional filler 1 kg, and toluene 20 kg; the B component is a curing agent; and the C component is a curing accelerator; wherein the ablative-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; and the heat-insulating functional filler is obtained by mixing fumed silica and zirconium dioxide / zinc oxide hollow microspheres in equal mass.

[0031] The liquid nitrile rubber modified graphene oxide is prepared by the following method: first, the graphene oxide is modified by γ-glycidoxypropyltrimethoxysilane to obtain modified graphene oxide; and then the modified graphene oxide is mixed and reacted with the amino-terminated liquid nitrile rubber.

[0032] The specific method of the modification treatment is that: γ-glycidoxypropyltrimethoxysilane is uniformly mixed with anhydrous ethanol according to a mass ratio of 1:2, then graphene oxide (prepared by improving the Hummers method) is added, stirring and reacting at 40℃ for 5 hours, and then 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.

[0033] The specific method of mixing and reacting the modified graphene oxide and the amino-terminated liquid butyl nitrile rubber is that: the modified graphene oxide is ultrasonically dispersed in ethyl acetate, the amino-terminated liquid butyl nitrile rubber is added, ultrasonic oscillation treatment is carried out at 300W for 20 minutes, stirring and reaction is carried out at 38℃ for 60 minutes, the precipitate is obtained by centrifugation, washed with ethyl acetate, and dried to obtain the product; wherein the mass ratio of the modified graphene oxide, ethyl acetate and amino-terminated liquid butyl nitrile rubber is 1:25:5.

[0034] 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 according to a molar ratio of 1:2:7, stirring until completely dissolved, hydrothermal reaction at 160℃ for 60 minutes, centrifugation to obtain the precipitate, water washing, drying, and calcination at 550℃ for 2 hours to obtain the product; wherein the amount of deionized water is 8 times the total mass of zirconium nitrate pentahydrate, zinc nitrate hexahydrate and glucose.

[0035] The curing agent is epoxy resin 593 curing agent (addition product of diethylenetriamine and butyl glycidyl ether); the curing accelerator is a mixture of dibutyltin dilaurate and 1-benzyl-3-methylimidazolium bis(trifluoromethanesulfonyl) imide salt according to a mass ratio of 1:0.2.

[0036] The mass ratio of component A, component B and component C is 90:5:1.

[0037] The preparation method of the aforementioned normal-temperature curing ablative-resistant coating is specifically as follows: S1. First, according to the formula composition, the ablative-resistant filler and the heat-insulating 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 butyl nitrile rubber are ultrasonically dispersed in the remaining formula amount of toluene to obtain a resin-rubber mixture; then the filler dispersion liquid is uniformly and slowly added to the resin-rubber mixture under stirring conditions, ultrasonic oscillation treatment is carried out under the condition of a pulse magnetic field, and grinding is carried out to obtain component A; S2. The curing agent is used as component B; and the curing accelerator is used as component C.

[0038] In step S1, the feeding time of the filler dispersion liquid is 30 minutes.

[0039] In step S1, the pulse magnetic field conditions are: frequency 20 Hz, current 40 A, pulse magnetic field current duty cycle 15%; the ultrasonic oscillation treatment conditions are: 400 W ultrasonic oscillation treatment for 20 minutes.

[0040] In step S1, a three-roller grinding machine is used for grinding, first with a roller gap of 0.5 mm for 2 passes, and then with a roller gap of 0.05 mm for 4 passes.

[0041] Example 2 A normal-temperature curing ablative-resistant coating is composed of three parts of A component, B component and C component: the A component comprises the following raw materials: epoxy resin 3 kg, liquid butyl nitrile rubber 4 kg, ablative-resistant filler 5 kg, heat-insulating functional filler 2 kg, and toluene 30 kg; the B component is a curing agent; the C component is a curing accelerator; wherein the ablative-resistant filler is obtained by mixing high-silicon fiber powder, chromium (III) oxide, aluminum hydroxide powder, carbon fiber powder, and liquid butyl nitrile rubber modified graphene oxide in a mass ratio of 10:5:30:5:10; the heat-insulating functional filler is obtained by mixing fumed silica and zirconium dioxide / zinc oxide hollow microspheres in equal mass.

[0042] The liquid butyl nitrile rubber modified graphene oxide is prepared by the following method: first, the graphene oxide is modified by γ-glycidyl ether oxypropyltrimethoxysilane to obtain modified graphene oxide; then the modified graphene oxide is mixed and reacted with the amino-terminated liquid butyl nitrile rubber to obtain the product.

[0043] The specific method of modification is as follows: γ-glycidyl ether oxypropyltrimethoxysilane and anhydrous ethanol are mixed uniformly in a mass ratio of 1:3, then graphene oxide (prepared by improving the Hummers method) is added, and stirred at 50°C for 7 hours, and the solvent is removed by rotary evaporation to obtain the modified graphene oxide; wherein the mass ratio of graphene oxide to γ-glycidyl ether oxypropyltrimethoxysilane is 1:0.7.

[0044] The specific method of mixing and reacting the modified graphene oxide with the amino-terminated liquid butyl nitrile rubber is as follows: the modified graphene oxide is ultrasonically dispersed in ethyl acetate, the amino-terminated liquid butyl nitrile rubber is added, 400 W ultrasonic oscillation treatment is performed for 30 minutes, 40°C stirring reaction is performed for 70 minutes, the precipitate is obtained by centrifugation, washed with ethyl acetate, and dried to obtain the product; wherein the mass ratio of modified graphene oxide, ethyl acetate, and amino-terminated liquid butyl nitrile rubber is 1:30:6.

[0045] The zirconium dioxide / zinc oxide hollow microspheres are prepared by the following method: zirconium nitrate pentahydrate, zinc nitrate hexahydrate and glucose are added into deionized water according to a molar ratio of 1:3:9, stirred until completely dissolved, hydrothermally reacted at 180 DEG C for 80 minutes, the precipitate is taken by centrifugation, washed with water, dried, calcined at 650 DEG C for 3 hours, and the zirconium dioxide / zinc oxide hollow microspheres are obtained; wherein the amount of deionized water is 10 times the total mass of zirconium nitrate pentahydrate, zinc nitrate hexahydrate and glucose.

[0046] The curing agent is epoxy resin 593 curing agent (diethylene triamine and butyl glycidyl ether addition product); the curing accelerator is a mixture of dibutyl tin dilaurate and 1-benzyl-3-methyl imidazole bis (trifluoromethane sulfonate) imidate salt according to a mass ratio of 1:0.3.

[0047] The mass ratio of component A, component B and component C is 110:10:5.

[0048] The preparation method of the aforementioned normal-temperature curing ablative-resistant coating is specifically as follows: S1. First, according to the formula composition, the ablative-resistant filler and the heat-insulating 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 butyl nitrile rubber are ultrasonically dispersed in the remaining formula amount of toluene to obtain a resin-rubber mixture; and then the filler dispersion liquid is uniformly and slowly added to the resin-rubber mixture under stirring conditions, and ultrasonic oscillation treatment is carried out under the condition of a pulse magnetic field, and grinding is carried out to obtain component A; S2. The curing agent is used as component B; and the curing accelerator is used as component C.

[0049] In step S1, the feeding time of the filler dispersion liquid is 40 minutes.

[0050] In step S1, the pulse magnetic field condition is: a frequency of 30 Hz, a current of 50 A, and a pulse magnetic field current duty cycle of 20%; and the ultrasonic oscillation treatment condition is: 500 W ultrasonic oscillation treatment for 30 minutes.

[0051] In step S1, a three-roll grinder is used for grinding, and first, 1 mm roll gap is used for grinding for 3 times, and then 0.1 mm roll gap is used for grinding for 5 times.

[0052] Example 3 The room temperature curing ablative resistant coating is composed of three parts of A component, B component and C component: the A component comprises the following raw materials: epoxy resin 2.5 kg, liquid butyl nitrile rubber 3.5 kg, ablative resistant filler 4.5 kg, heat insulation functional filler 1.5 kg, toluene 25 kg; the B component is a curing agent; the C component is a curing accelerator; wherein the ablative resistant filler is obtained by mixing high silicon fiber powder, chromium (III) oxide, aluminum hydroxide powder, carbon fiber powder and liquid butyl nitrile rubber modified graphene oxide according to a mass ratio of 8:4:25:3:7; the heat insulation functional filler is obtained by mixing fumed silica and zirconium dioxide / zinc oxide hollow microspheres in equal quality.

[0053] The liquid butyl nitrile rubber modified graphene oxide is prepared by the following method: first, the graphene oxide is modified by γ-glycidyl ether oxypropyl trimethoxysilane to obtain modified graphene oxide; then the modified graphene oxide is mixed and reacted with the amino-terminated liquid butyl nitrile rubber to obtain the liquid butyl nitrile rubber modified graphene oxide.

[0054] The specific method of the modification treatment is: mixing γ-glycidyl ether oxypropyl trimethoxysilane and anhydrous ethanol uniformly according to a mass ratio of 1:2.5, then adding graphene oxide (prepared by improving the Hummers method), stirring and reacting at 45℃ for 6 hours, and removing the solvent by rotary evaporation to obtain the modified graphene oxide; wherein the mass ratio of graphene oxide to γ-glycidyl ether oxypropyl trimethoxysilane is 1:0.6.

[0055] The specific method of the mixing and reaction of the modified graphene oxide and the amino-terminated liquid butyl nitrile rubber is: ultrasonic dispersion of the modified graphene oxide in ethyl acetate, addition of the amino-terminated liquid butyl nitrile rubber, 400W ultrasonic oscillation treatment for 25 minutes, 39℃ stirring reaction for 65 minutes, centrifugal precipitation, ethyl acetate washing, and drying to obtain the product; wherein the mass ratio of the modified graphene oxide, ethyl acetate and amino-terminated liquid butyl nitrile rubber is 1:28:5.5.

[0056] The zirconium dioxide / zinc oxide hollow microspheres are prepared by the following method: adding zirconium nitrate pentahydrate, zinc nitrate hexahydrate and glucose in a molar ratio of 1:2.5:8 into deionized water, stirring until completely dissolved, hydrothermal reaction at 170℃ for 70 minutes, centrifugal precipitation, water washing, drying, and calcination at 600℃ for 2 hours to obtain the product; wherein the amount of deionized water is 9 times the total mass of zirconium nitrate pentahydrate, zinc nitrate hexahydrate and glucose.

[0057] The curing agent is epoxy resin 593 curing agent (addition product of diethylenetriamine and butyl glycidyl ether); the curing accelerator is obtained by mixing dibutyltin dilaurate and 1-benzyl-3-methylimidazolium bis(trifluoromethanesulfonyl) imide salt according to a mass ratio of 1:0.25.

[0058] The mass ratio of the A component, the B component and the C component is 100:8:3.

[0059] The preparation method of the aforementioned normal-temperature curing ablative-resistant coating is specifically as follows: S1. First, according to the formula composition, the ablative-resistant filler and the heat-insulating 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 butyl nitrile rubber are ultrasonically dispersed in the remaining formula amount of toluene to obtain a resin-rubber mixture; and then the filler dispersion liquid is uniformly and slowly added to the resin-rubber mixture under stirring, and ultrasonic oscillation treatment is carried out under the condition of a pulsed magnetic field to obtain the A component; S2. The curing agent is used as the B component; and the curing accelerator is used as the C component.

[0060] In step S1, the feeding time of the filler dispersion liquid is 35 minutes.

[0061] In step S1, the pulsed magnetic field condition is: a frequency of 30 Hz, a current of 45 A, and a pulsed magnetic field current duty cycle of 17%; and the ultrasonic oscillation treatment condition is: 500 W ultrasonic oscillation treatment for 25 minutes.

[0062] In step S1, a three-roll grinder is used for grinding, and first, the grinding is carried out for 3 times at a roll gap of 0.7 mm, and then the grinding is carried out for 5 times at a roll gap of 0.08 mm.

[0063] Comparative Example 1 The liquid butyl nitrile rubber modified graphene oxide is omitted. The rest is the same as in Example 1.

[0064] Comparative Example 2 The zirconium dioxide / zinc oxide hollow microspheres are omitted. The rest is the same as in Example 1.

[0065] Comparative Example 3 The curing accelerator is omitted, i.e., 1-benzyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt. The rest is the same as in Example 1.

[0066] Comparative Example 4 A coating is composed of three parts of an A component, a B component and a C component: the A component includes the following raw materials: 2 kg of epoxy resin, 3 kg of liquid butyl nitrile rubber, 2.7 kg of ablative-resistant filler, 1 kg of heat-insulating functional filler, and 20 kg of toluene; the B component is a curing agent; and the C component is a curing accelerator; wherein the ablative-resistant filler is obtained by mixing high-silica fiber powder, chromium(III) oxide, aluminum hydroxide powder, carbon fiber powder and liquid butyl nitrile rubber at a mass ratio of 5:1:20:1:5; and the heat-insulating functional filler is obtained by mixing fumed silica and zirconium dioxide / zinc oxide hollow microspheres in equal mass.

[0067] The liquid nitrile rubber modified graphene oxide is prepared by the following method: first, the graphene oxide is modified by γ-glycidoxypropyltrimethoxysilane to obtain modified graphene oxide; then the modified graphene oxide is mixed and reacted with the amino-terminated liquid nitrile rubber to obtain the product.

[0068] The specific method of the modification treatment is as follows: γ-glycidoxypropyltrimethoxysilane and anhydrous ethanol are mixed uniformly according to a mass ratio of 1:2, then graphene oxide (prepared by improving the Hummers method) is added, and stirred and reacted at 40℃ for 5 hours, and the solvent is removed by rotary evaporation to obtain the modified graphene oxide; wherein the mass ratio of graphene oxide to γ-glycidoxypropyltrimethoxysilane is 1:0.5.

[0069] The specific method of the mixed reaction of the modified graphene oxide and the 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, ultrasonic oscillation treatment is performed at 300W for 20 minutes, stirring reaction is performed at 38℃ for 60 minutes, the precipitate is taken by centrifugation, washed with ethyl acetate, and dried to obtain the product; wherein the mass ratio of the modified graphene oxide, ethyl acetate and amino-terminated liquid nitrile rubber is 1:25:5.

[0070] 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 according to a molar ratio of 1:2:7, stirred until completely dissolved, hydrothermally reacted at 160℃ for 60 minutes, the precipitate is taken by centrifugation, washed with water, and dried, and then calcined at 550℃ for 2 hours to obtain the product; wherein the amount of deionized water is 8 times the total mass of zirconium nitrate pentahydrate, zinc nitrate hexahydrate and glucose.

[0071] The curing agent is epoxy resin 593 curing agent (addition product of diethylenetriamine and butyl glycidyl ether); the curing accelerator is a mixture of dibutyltin dilaurate and 1-benzyl-3-methylimidazolium bis(trifluoromethanesulfonyl) imide salt according to a mass ratio of 1:0.2.

[0072] The mass ratio of component A, component B and component C is 90:5:1.

[0073] The preparation method of the aforementioned coating is as follows: S1. First, according to the formula composition, the ablative filler and the heat insulation functional filler are ultrasonically dispersed in toluene, then the epoxy resin and the liquid nitrile rubber are added, ultrasonic oscillation treatment is performed, and grinding is performed to obtain component A; S2. The curing agent is used as component B; the curing accelerator is used as component C.

[0074] In step S1, the ultrasonic oscillation treatment was performed at 400 W for 20 minutes.

[0075] In step S1, the grinding was performed using a three-roll grinder. First, the grinding was performed twice at a roll gap of 0.5 mm, and then the grinding was performed four times at a roll gap of 0.05 mm.

[0076] Test Example The paint obtained in Examples 1 to 3 and Comparative Examples 1 to 4 was respectively brushed on the surface of a stainless steel substrate. Specifically, the A component, the B component and the C component were mixed uniformly, and then left to stand for 5 to 10 minutes. The mixture was brushed on the surface of a cleaned stainless steel substrate (100 mm x 50 mm x 1 mm), and then cured under the conditions of a temperature of 25°C and a relative humidity of 65% to form a coating layer having a thickness of 0.2 mm, thereby obtaining a sample.

[0077] The surface dry time and the actual dry time were determined according to GB / T 1728-2020 “Determination of Dry Time of Paint Film and Putty Film”.

[0078] The ablation resistance and the heat insulation performance of the coating layer were further tested. Ablation resistance: an oxygen-acetylene flame ablation test was performed to detect the linear ablation rate, and the test time was 10 s. The specific test conditions were as follows: Oxygen, pressure 0.30 MPa, flow rate 14.2 L / min; Acetylene, pressure 0.09 MPa, flow rate 10.5 L / min; Heat flux density 1000 kW / m 2 ; Nozzle diameter 2 mm; Ablation distance 50 mm.

[0079] Heat insulation performance test method: the sample was placed in a sealed box, and the sample coating surface was irradiated by a 250 W incandescent lamp for 5 hours. The temperature sensor and the temperature display were used to test and display the temperature at the bottom of the sample. The lower the temperature at the bottom of the sample, the better the heat insulation performance.

[0080] The test results are shown in Table 1.

[0081] Table 1. Coating performance test As shown in Table 1, the paint obtained in Examples 1 to 3 can be cured at room temperature, and has excellent ablation resistance and heat insulation performance.

[0082] The curing accelerator 1-benzyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt in Comparative Example 3 significantly increased the curing time, and also affected the ablation resistance and the heat insulation performance of the coating layer.

[0083] Comparative Example 1 omits liquid butyl nitrile rubber modified graphene oxide, Comparative Example 2 omits zirconium dioxide / zinc oxide hollow microspheres, Comparative Example 4 uses a direct mixing method in the preparation of component A, and the ablation resistance and thermal insulation performance are obviously deteriorated, which indicates that the ablation resistant filler, the thermal insulation functional filler and the specific mixing method of the present application have a synergistic effect, and the coating performance is improved.

[0084] The present application is illustrated by the above examples, but the present application is not limited to the above examples, i.e. it does not mean that the present application must rely on the above examples to be implemented. It should be understood by those skilled in the art that any improvement of the present application, equivalent replacement of individual raw materials of the product of the present application, addition of auxiliary ingredients, selection of specific methods, etc. fall within the protection scope and disclosure scope of the present application.

Claims

1. A room-temperature curing, ablation-resistant coating, characterized in that, It consists of 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 thermal insulation filler, and 200-300 parts toluene. Component B is a curing agent. 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 thermal insulation filler includes fumed silica.

2. The room-temperature curing ablation-resistant coating according to claim 1, characterized in that, 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.

3. The room-temperature curing ablation-resistant coating according to claim 1, characterized in that, The ablation-resistant filler also includes liquid nitrile rubber-modified graphene oxide in the same mass as the high-silica fiber powder.

4. The room-temperature curing ablation-resistant coating according to claim 1, characterized in that, The heat-insulating filler also includes zirconium dioxide / zinc oxide hollow microspheres, specifically obtained by mixing fumed silica with zirconium dioxide / zinc oxide hollow microspheres in equal mass.

5. The room-temperature curing ablation-resistant coating according to claim 1, characterized in that, The curing agent is epoxy resin 593 curing agent; 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.

6. The room-temperature curing ablation-resistant coating according to claim 1, characterized in that, The mass ratio of component A, component B, and component C is 90–110:5–10:1–5.

7. A method for preparing a room-temperature curing ablation-resistant coating according to any one of claims 1 to 6, characterized in that, The specific steps are as follows: 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. S2. The curing agent is component B; the curing accelerator is component C.

8. The preparation method according to claim 7, characterized in that, In step S1, the pulsed magnetic field conditions are: frequency 20-30Hz, current 40-50A, and pulsed magnetic field current duty cycle 15-20%; the ultrasonic oscillation treatment conditions are: 400-500W ultrasonic oscillation treatment for 20-30 minutes.

9. The preparation method according to claim 7, characterized in that, 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.

10. A method of using a room-temperature curing ablation-resistant coating as described in any one of claims 1 to 6, characterized in that, Mix components A, B, and C thoroughly, let stand for 5–10 minutes, and then apply by spraying or brushing to the cleaned substrate surface. Curing time is 20–24 hours at a temperature of 18–25°C and a relative humidity of 65%.

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