High-temperature resistant metal surface coating and preparation method thereof

Abstract

The invention discloses a high-temperature resistant metal surface coating and a preparation method thereof, comprising the following components by weight: 40-60 parts of ceramic silicone resin, 20-30 parts of polyethersulfone modified organic fluorine resin, 8-10 parts of water-based polyimide resin, 10-15 parts of zinc chrome yellow, 4-6 parts of boron nitride, 3-5 parts of modified phenolic amine curing agent, 8-15 parts of barium sulfate, 8-10 parts of chopped carbon fibers, 5-8 parts of hollow glass microspheres, 2-4 parts of silane coupling agent, 1-3 parts of organosilicon defoaming agent, 8-12 parts of dispersant, 1-2 parts of thickener, and 6-9 parts of composite coating anti-aging agent. The invention relates to the technical field of metal surface coating preparation. The high-temperature resistant metal surface coating and the preparation method thereof adopt ceramic silicone resin, polyethersulfone modified organic fluorine resin and water-based polyimide resin as main resin components, can form a stable structure at high temperature, and can withstand higher temperatures.

Description

Technical Field

[0001] The present invention relates to the technical field of metal surface coating preparation, in particular to a high-temperature resistant metal surface coating and a preparation method thereof. Background Art

[0002] In many industrial fields, high-temperature resistant metal surface coatings play a vital role. For example, in the aerospace field, the engine components and casings of aircraft need to withstand extreme high-temperature environments. Good high-temperature resistant coatings can protect metal components, ensure their stable performance and extended service life, and ensure the safe operation of aircraft. In the energy industry, such as thermal power generation equipment and high-temperature reaction devices in petrochemicals, metal surfaces are exposed to harsh working conditions such as high temperature and corrosion for a long time. High-temperature resistant coatings can effectively prevent metal corrosion and oxidation, improve equipment reliability and operating efficiency, and reduce maintenance costs.

[0003] Some high-temperature resistant coatings currently on the market have many problems. Their anti-aging performance is insufficient. Under the influence of environmental factors such as long-term high temperature and light, they are prone to aging and cracking, which leads to a decrease in the protective performance of the coating. Their composition is not optimized enough and cannot simultaneously take into account the requirements of high temperature resistance, good adhesion, mechanical properties and other aspects. Therefore, the development of a metal surface coating with excellent high-temperature resistance and good anti-aging performance has become an urgent need in the current industrial field. Summary of the Invention

[0004] To achieve the above objectives, the present invention is implemented through the following technical scheme: a high-temperature resistant metal surface coating, comprising the following components by weight: ceramic silicone resin: 40-60 parts, polyethersulfone modified organic fluorine resin: 20-30 parts, water-based polyimide resin: 8-10 parts, zinc chrome yellow: 10-15 parts, boron nitride: 4-6 parts, modified phenolic amine curing agent: 3-5 parts, barium sulfate: 8-15 parts, short-cut carbon fiber: 8-10 parts, hollow glass microspheres: 5-8 parts, silane coupling agent: 2-4 parts, organosilicon defoaming agent: 1-3 parts, dispersant: 8-12 parts, thickener: 1-2 parts, composite coating anti-aging agent: 6-9 parts;

[0005] The specific preparation method of the composite coating anti-aging agent is as follows:

[0006] Step 1: Dry the nano zinc oxide in a vacuum drying oven at 80°C for 4 hours to remove moisture, and then perform ultrafine grinding. Grind 4-hydroxybenzophenone, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole and a composite hindered amine light stabilizer in a ball mill respectively;

[0007] Step 2: Add acrylic resin to the reactor, add 5%-8% ethyl acetate as a solvent, stir, and heat to 50°C-55°C. Add 4-hydroxybenzophenone, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole, composite hindered amine light stabilizer, nano zinc oxide, antioxidant and dispersant to the reactor, continue stirring, and add each addition for 15 minutes;

[0008] Step 3: Use an ultrasonic disperser to ultrasonically disperse the mixture in the reactor. During the ultrasonic process, the temperature is maintained at 50°C ± 2°C and the temperature is controlled by a circulating water bath.

[0009] Step 4: Remove the solvent from the ultrasonically dispersed mixture by vacuum distillation, control the distillation temperature at 60-70°C, and the vacuum degree at -0.08MPa to -0.1MPa. After removing the solvent, cool it to room temperature to obtain a composite coating anti-aging agent.

[0010] Preferably, the silane coupling agent is bis-[γ-(triethoxysilyl)propyl]tetrasulfide, and the thickener is fumed silica thickener.

[0011] Preferably, the specific preparation method of the composite hindered amine light stabilizer in step 1 is as follows:

[0012] Step A1: adding tetrahydrodicyclopentadienylamine and potassium carbonate catalyst to a reaction kettle, and reacting bromoalkane under nitrogen protection, controlling the reaction temperature at 80-90°C, and reacting for 6-8 hours. After the reaction, cooling, filtering, and washing are performed to obtain hindered amine compound A;

[0013] Step A2: adding hydrogen siloxane and tetramethylpiperidinamine derivative into a reaction vessel, adding chloroplatinic acid catalyst, heating and stirring, and reacting at 60-70° C. for 4-6 hours to obtain hindered amine compound B;

[0014] Step A3: First, add the carrier resin phenolic modified epoxy resin into the mixer, start stirring, set the speed to 800-1000 rpm, add antioxidant 1010, ultraviolet absorber and dispersant in sequence, mix for 15-20 minutes, reduce the stirring speed to 500-600 rpm, and then add hindered amine compound A and hindered amine compound B in sequence. After the addition is complete, increase the stirring speed to 1200-1500 rpm and continue stirring for 30-40 minutes;

[0015] Step A4: The uniformly mixed material is extruded and granulated through a twin-screw extruder. The extruded material is cooled and pelletized to obtain composite hindered amine light stabilizer particles.

[0016] Preferably, the ultraviolet absorber in step A3 is a triazine derivative, and the dispersant in step A3 is polyethylene wax.

[0017] Preferably, the composite coating anti-aging agent includes the following components by weight: 4-hydroxybenzophenone: 12-15 parts, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole 12-14 parts, hindered amine light stabilizer 18-20 parts, nano zinc oxide 14-16 parts, acrylic resin 35-45 parts, antioxidant 1-2.5 parts, and dispersant 0.8-1.6 parts.

[0018] A method for preparing a high-temperature resistant metal surface coating comprises the following steps:

[0019] Step S1: ceramic silicone resin, polyethersulfone modified organic fluorine resin and water-based polyimide resin are placed in a reaction kettle and heated to 40-50°C, and stirred at 100-200 rpm for 30 minutes to obtain a mixed resin A; boron nitride, barium sulfate and chopped carbon fibers are placed in a vacuum drying oven, dried, and then ground using a grinding device, filtered and set aside; hollow glass microspheres are preheated at 80-100°C for 1-2 hours;

[0020] Step S2: In a reactor equipped with a high-speed disperser, a heating device, and a temperature control, monitoring, and speed regulation system, xylene and n-butanol are mixed in a volume ratio of 3:1 to obtain a solvent, and the boron nitride, barium sulfate, chopped carbon fibers, and hollow glass microspheres pretreated in step S1 are added, along with a dispersant;

[0021] Step S3: pouring the mixed resin A pretreated in step S1 into the reactor;

[0022] Step S4: In a reaction kettle, a silane coupling agent, an organosilicon defoaming agent, and a composite coating anti-aging agent are sequentially added, and finally a thickener is added, and the mixture is stirred to obtain a high-temperature resistant metal surface coating.

[0023] Preferably, the total amount of the mixed solvent of toluene and n-butanol in step S2 is 15-20% of the total amount of the resin.

[0024] Preferably, the temperature control, monitoring and speed regulation system in step S2 has the following control method:

[0025] Step 1: System initialization;

[0026] (2) Set the temperature control parameters. The lower limit of high-speed dispersion operation temperature is 40°C, the upper limit is 50°C, and the allowable range of temperature fluctuation is ±1°C.

[0027] (3) Set the speed control parameters, the initial stirring speed is 500 rpm, the speed increase gradient during the filler addition process, and the final high-speed dispersion speed target value is 1800 rpm, and the speed deviation allowable range is ±35 rpm.

[0028] Step 2: Preheating of hollow glass microspheres;

[0029] (1) The temperature sensor monitors the temperature inside the reactor in real time. When the hollow glass microspheres begin to preheat, the system records the initial temperature T0;

[0030] (2) As the preheating process progresses, the temperature sensor continuously transmits temperature data to the control system, and the operator can view the temperature changes in real time through the display screen;

[0031] (3) The lower limit of the preheating target temperature is 80°C and the upper limit is 100°C. If the temperature is lower than the preheating target temperature range, the heating device control system starts and gradually increases the heating power to increase the temperature;

[0032] (4) When the temperature approaches or reaches the upper limit of the preheating target temperature of 100°C, the heating device control system reduces the power or stops heating, and maintains the temperature within the preheating target temperature range through feedback control, and the temperature fluctuation is controlled within ±2°C;

[0033] Step 3: Filler addition and high-speed dispersion;

[0034] (1) When the filler is added, the speed monitoring device records the initial stirring speed as 500 rpm. As the filler is gradually added, the system increases the gradient according to the preset speed, monitors the changes in the stirring speed in real time, and feeds the data back to the control system;

[0035] (2) The high-speed disperser drive motor control system increases the stirring speed by 100 rpm every 5 minutes according to the preset program during the filler addition process until the high-speed dispersion speed target value of 1800 rpm is reached. During the high-speed dispersion process, if the actual speed deviates from the set target speed and the deviation exceeds ±35 rpm, the speed control system will immediately fine-tune the drive motor, increase or decrease the motor power, and restore the stirring speed to the target range;

[0036] (3) The temperature sensor continuously monitors the temperature during the entire process of filler addition and high-speed dispersion. Due to changes in stirring speed and material mixing reaction, the temperature changes. When the temperature is lower than the lower limit of the high-speed dispersion operating temperature of 40°C, the heating device starts to increase the temperature. When the temperature is higher than the upper limit of 50°C, the cooling device starts to lower the temperature. The temperature fluctuation is always controlled within ±1°C.

[0037] Preferably, the working process of the heating device control system in the second step is as follows:

[0038] Step B1: During the heating process, a high-precision temperature sensor monitors the temperature of the solvent and material mixture system in the reactor. The temperature sensor transmits the real-time collected temperature data to the controller in the form of an electrical signal. After receiving the temperature data, the controller processes and analyzes it and compares the actual temperature with the set target temperature range;

[0039] Step B2: When the actual temperature is lower than the lower limit of the target temperature, the controller issues a command to increase the heating power. The heating device may use a resistance wire heating method. The controller adjusts the heating power. As the temperature gradually approaches the target temperature range, the controller gradually reduces the increase in the heating power according to a preset algorithm.

[0040] Step B3: When the temperature reaches the target temperature range, the heating device control system enters the temperature maintenance phase. At this time, the controller monitors the temperature change and fine-tunes the heating power to compensate for the slight temperature drop caused by factors such as heat loss;

[0041] Step B4: The temperature sensor acts as a feedback element to feed back the temperature information in the reactor to the controller in real time. The controller compares the temperature feedback data with the set temperature and calculates the temperature deviation. If the temperature deviation exceeds ±2°C, the controller adjusts the heating power.

[0042] Preferably, the algorithm preset by the controller in step B2 is as follows:

[0043] The temperature range of the entire heating process is divided into multiple intervals. Assuming the lower limit of the target temperature is T1 and the upper limit is T2, the intervals can be divided as follows;

[0044] Low temperature range: T0 to T1- T1;

[0045] Medium temperature range: T1- T1 to T2- T2;

[0046] High temperature range: T2- T2 to T2;

[0047] In the low temperature range, the initial heating power is set to P0, and the heating power in this range increases by P1, that is, the first heating power is adjusted to P0+ P1, the second heating power is adjusted to P0+2 P1;

[0048] In the medium temperature range, if the temperature rises by 1℃, the increase of heating power will decrease. P2, when the temperature changes from T1- When T1 starts to rise, the heating power increases by = P1- P2;

[0049] As the temperature continues to rise, let the current temperature be T, T1- T1<T<T2- T2, heating power increase The calculation formula is = P1- P2 (T-(T1- T1));

[0050] In the high temperature range, when the temperature enters the high temperature range, the increase in heating power is very small and approaches zero. When the temperature reaches T2- At T2, the increase in heating power decreases to P3;

[0051] At temperatures from T2- T2 rises to T2, let the current temperature be T, T2- T2<T<T2, heating power increase Further reduce, The calculation formula is = P3- P4 (T-(T2- T2)), where P4 is the amplitude value that is further reduced in the high temperature range.

[0052] The present invention provides a high-temperature resistant metal surface coating and a preparation method thereof. It has the following beneficial effects:

[0053] The high-temperature resistant metal surface coating and its preparation method use ceramic silicone resin, polyethersulfone modified organic fluorine resin and water-based polyimide resin as main resin components. The ceramic silicone resin is a thermosetting polysiloxane polymer with a highly cross-linked structure. This cross-linked structure is like a three-dimensional network that tightly connects molecules together. At high temperatures, the cross-linked structure can prevent the free movement and slippage of molecular chains, so that the resin maintains the stability of its shape and can withstand higher temperatures. At the same time, the heat insulation effect of the hollow glass microspheres and the reinforcement effect of the chopped carbon fibers reduce the transfer and accumulation of heat in the coating, further improving the high-temperature resistance of the coating. Compared with traditional coatings, it can remain stable at higher temperatures. The oxide film formed by zinc chrome yellow mainly fills the pores on the metal surface, while the flaky structure of boron nitride is in Physical barrier is carried out on a larger scale. The flaky structure of boron nitride can cover the preliminary protective film formed by zinc chrome yellow, further improving the integrity of the protective film. Through the synergistic effect of zinc chrome yellow and boron nitride, a dense protective film is formed on the metal surface to prevent corrosion by corrosive media such as acids, alkalis, and salts. Good coating adhesion and barrier properties effectively isolate the metal from the external environment and reduce the chance of electrochemical corrosion. A specially prepared composite coating anti-aging agent contains 4-hydroxybenzophenone, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole, hindered amine light stabilizer, nano zinc oxide and other ingredients. 4-hydroxybenzophenone and 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole are both UV absorbers.Their molecular structures contain functional groups that can absorb ultraviolet energy. When the coating is exposed to ultraviolet light, these functional groups can absorb the energy of ultraviolet photons and cause intramolecular electronic transitions. For example, electronic transitions occur between the carbonyl and hydroxyl groups in the 4-hydroxybenzophenone molecule, converting ultraviolet energy into harmless heat energy and releasing it, thereby preventing ultraviolet rays from directly destroying the chemical bonds of the coating. 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole also absorbs ultraviolet light through a similar intramolecular energy conversion mechanism. The two components have certain complementarity in the ultraviolet absorption spectrum. 4-hydroxybenzophenone mainly absorbs ultraviolet light in the wavelength range of 280-340nm, while 2-( 2'-Hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole has a good effect on absorbing ultraviolet rays in the wavelength range of 300-380nm. In actual environments, the wavelength range of ultraviolet rays is relatively wide. The combination of the two can absorb ultraviolet rays more comprehensively, expand the wavelength range of ultraviolet protection, and reduce the photoaging effect of ultraviolet rays on coatings. It can effectively absorb ultraviolet rays, capture free radicals, and interrupt the photooxidation chain reaction, thereby delaying the aging process of the coating and extending the service life of the coating. In addition, the precise temperature control and stable speed control work together to ensure that the various components of the coating can be fully and evenly mixed during the preparation process, and the chemical reaction can be carried out under suitable conditions, ensuring the performance stability of the coating in different batches of production. DETAILED DESCRIPTION

[0054] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0055] In a first embodiment, the present invention provides a technical solution: a high-temperature resistant metal surface coating, comprising the following components by weight: ceramic silicone resin: 40 parts, polyethersulfone modified organic fluorine resin: 20 parts, water-based polyimide resin: 8 parts, zinc chrome yellow: 10 parts, boron nitride: 4 parts, modified phenolic amine curing agent: 3 parts, barium sulfate: 8 parts, chopped carbon fibers: 8 parts, hollow glass microspheres: 5 parts, bis-[γ-(triethoxysilyl)propyl]tetrasulfide: 2 parts, organic silicon defoamer: 1 part, dispersant: 8 parts, fumed silica thickener: 1 part, and composite coating anti-aging agent: 6 parts;

[0056] Among them, the specific preparation method of the composite coating anti-aging agent is as follows:

[0057] Step 1: Dry the nano zinc oxide in a vacuum drying oven at 80°C for 4 hours to remove moisture, and then perform ultrafine grinding. Grind 4-hydroxybenzophenone, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole and a composite hindered amine light stabilizer in a ball mill respectively;

[0058] Step 2: Add acrylic resin to the reactor, add 5% ethyl acetate as a solvent, stir, and heat to 50°C. Add 4-hydroxybenzophenone, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole, composite hindered amine light stabilizer, nano zinc oxide, antioxidant and dispersant to the reactor, continue stirring, and add each addition for 15 minutes;

[0059] Step 3: Use an ultrasonic disperser to ultrasonically disperse the mixture in the reactor. During the ultrasonic process, the temperature is maintained at 50°C ± 2°C and the temperature is controlled by a circulating water bath.

[0060] Step 4: Remove the solvent from the ultrasonically dispersed mixture by vacuum distillation. The distillation temperature is controlled at 60°C and the vacuum degree is -0.08MPa. After the solvent is removed, the composite coating anti-aging agent is cooled to room temperature.

[0061] The specific preparation method of the composite hindered amine light stabilizer in step 1 is as follows:

[0062] Step A1: adding tetrahydrodicyclopentadienylamine and potassium carbonate catalyst to a reaction kettle, and reacting bromoalkane under nitrogen protection, controlling the reaction temperature at 80° C., and reacting for 6 hours. After the reaction is completed, cooling, filtering, and washing are performed to obtain hindered amine compound A;

[0063] Step A2: adding hydrogen siloxane and tetramethylpiperidinamine derivative into a reaction vessel, adding chloroplatinic acid catalyst, heating and stirring, and reacting at 60° C. for 4 hours to obtain hindered amine compound B;

[0064] Step A3: First, add the carrier resin phenolic modified epoxy resin to the mixer and start stirring at 800 rpm. Then, add antioxidant 1010, triazine derivative, and polyethylene wax in sequence and mix for 15 minutes. Then, reduce the stirring speed to 500 rpm and sequentially add hindered amine compound A and hindered amine compound B. After the addition is complete, increase the stirring speed to 1200 rpm and continue stirring for 30 minutes.

[0065] Step A4: The uniformly mixed material is extruded and granulated through a twin-screw extruder. The extruded material is cooled and pelletized to obtain composite hindered amine light stabilizer particles.

[0066] The composite coating anti-aging agent includes the following components by weight: 12 parts of 4-hydroxybenzophenone, 12 parts of 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole, 18 parts of hindered amine light stabilizer, 14 parts of nano zinc oxide, 35 parts of acrylic resin, 1 part of antioxidant, and 0.8 part of dispersant.

[0067] A method for preparing a high-temperature resistant metal surface coating comprises the following steps:

[0068] Step S1: ceramic silicone resin, polyethersulfone modified organic fluorine resin and water-based polyimide resin are placed in a reactor and heated to 40°C, and stirred at 100 rpm for 30 minutes to obtain a mixed resin A; boron nitride, barium sulfate and chopped carbon fibers are placed in a vacuum drying oven, dried, and then ground using a grinding device, filtered and set aside; hollow glass microspheres are preheated at 80°C for 1 hour;

[0069] Step S2: In a reactor equipped with a high-speed disperser, a heating device, and a temperature control, monitoring, and speed regulation system, xylene and n-butanol are mixed in a volume ratio of 3:1 to obtain a solvent, and the boron nitride, barium sulfate, chopped carbon fibers, and hollow glass microspheres pretreated in step S1 are added, along with a dispersant;

[0070] Step S3: pouring the mixed resin A pretreated in step S1 into the reactor;

[0071] Step S4: In a reaction kettle, add bis-[γ-(triethoxysilyl)propyl]tetrasulfide, an organosilicon defoamer, and a composite coating anti-aging agent in sequence, and finally add a fumed silica thickener, and stir to obtain a high-temperature resistant metal surface coating.

[0072] The temperature control, monitoring and speed regulation system in step S2 has the following control method:

[0073] Step 1: System initialization;

[0074] (2) Set the temperature control parameters. The lower limit of high-speed dispersion operation temperature is 40°C, the upper limit is 50°C, and the allowable range of temperature fluctuation is ±1°C.

[0075] (3) Set the speed control parameters, the initial stirring speed is 500 rpm, the speed increase gradient during the filler addition process, and the final high-speed dispersion speed target value is 1800 rpm, and the speed deviation allowable range is ±35 rpm.

[0076] Step 2: Preheating of hollow glass microspheres;

[0077] (1) The temperature sensor monitors the temperature inside the reactor in real time. When the hollow glass microspheres begin to preheat, the system records the initial temperature T0;

[0078] (2) As the preheating process progresses, the temperature sensor continuously transmits temperature data to the control system, and the operator can view the temperature changes in real time through the display screen;

[0079] (3) The lower limit of the preheating target temperature is 80°C and the upper limit is 100°C. If the temperature is lower than the preheating target temperature range, the heating device control system starts and gradually increases the heating power to increase the temperature;

[0080] (4) When the temperature approaches or reaches the upper limit of the preheating target temperature of 100°C, the heating device control system reduces the power or stops heating, and maintains the temperature within the preheating target temperature range through feedback control, and the temperature fluctuation is controlled within ±2°C;

[0081] Step 3: Filler addition and high-speed dispersion;

[0082] (1) When the filler is added, the speed monitoring device records the initial stirring speed as 500 rpm. As the filler is gradually added, the system increases the gradient according to the preset speed, monitors the changes in the stirring speed in real time, and feeds the data back to the control system;

[0083] (2) The high-speed disperser drive motor control system increases the stirring speed by 100 rpm every 5 minutes according to the preset program during the filler addition process until the high-speed dispersion speed target value of 1800 rpm is reached. During the high-speed dispersion process, if the actual speed deviates from the set target speed and the deviation exceeds ±35 rpm, the speed control system will immediately fine-tune the drive motor, increase or decrease the motor power, and restore the stirring speed to the target range;

[0084] (3) The temperature sensor continuously monitors the temperature during the entire process of filler addition and high-speed dispersion. Due to changes in stirring speed and material mixing reaction, the temperature changes. When the temperature is lower than the lower limit of the high-speed dispersion operating temperature of 40°C, the heating device starts to increase the temperature. When the temperature is higher than the upper limit of 50°C, the cooling device starts to lower the temperature. The temperature fluctuation is always controlled within ±1°C.

[0085] The working process of the heating device control system in the second step is as follows:

[0086] Step B1: During the heating process, a high-precision temperature sensor monitors the temperature of the solvent and material mixture system in the reactor. The temperature sensor transmits the real-time collected temperature data to the controller in the form of an electrical signal. After receiving the temperature data, the controller processes and analyzes it and compares the actual temperature with the set target temperature range;

[0087] Step B2: When the actual temperature is lower than the lower limit of the target temperature, the controller issues a command to increase the heating power. The heating device may use a resistance wire heating method. The controller adjusts the heating power. As the temperature gradually approaches the target temperature range, the controller gradually reduces the increase in the heating power according to a preset algorithm.

[0088] Step B3: When the temperature reaches the target temperature range, the heating device control system enters the temperature maintenance phase. At this time, the controller monitors the temperature change and fine-tunes the heating power to compensate for the slight temperature drop caused by factors such as heat loss;

[0089] Step B4: The temperature sensor acts as a feedback element to feed back the temperature information in the reactor to the controller in real time. The controller compares the temperature feedback data with the set temperature and calculates the temperature deviation. If the temperature deviation exceeds ±2°C, the controller adjusts the heating power.

[0090] The algorithm preset by the controller in step B2 is as follows:

[0091] The temperature range of the entire heating process is divided into multiple intervals. Assuming the lower limit of the target temperature is T1 and the upper limit is T2, the intervals can be divided as follows;

[0092] Low temperature range: T0 to T1- T1;

[0093] Medium temperature range: T1- T1 to T2- T2;

[0094] High temperature range: T2- T2 to T2;

[0095] In the low temperature range, the initial heating power is set to P0, and the heating power in this range increases by P1, that is, the first heating power is adjusted to P0+ P1, the second heating power is adjusted to P0+2 P1;

[0096] In the medium temperature range, if the temperature rises by 1℃, the increase of heating power will decrease. P2, when the temperature changes from T1- When T1 starts to rise, the heating power increases by = P1- P2;

[0097] As the temperature continues to rise, let the current temperature be T, T1- T1<T<T2- T2, heating power increase The calculation formula is = P1- P2 (T-(T1- T1));

[0098] In the high temperature range, when the temperature enters the high temperature range, the increase in heating power is very small and approaches zero. When the temperature reaches T2- At T2, the increase in heating power decreases to P3;

[0099] At temperatures from T2- T2 rises to T2, let the current temperature be T, T2- T2<T<T2, heating power increase Further reduce, The calculation formula is = P3- P4 (T-(T2- T2)), where P4 is the amplitude value that is further reduced in the high temperature range.

[0100] In a second embodiment, the present invention provides a technical solution: a high-temperature resistant metal surface coating, characterized in that it includes the following components by weight: ceramic silicone resin: 50 parts, polyethersulfone modified organic fluorine resin: 25 parts, water-based polyimide resin: 9 parts, zinc chrome yellow: 12 parts, boron nitride: 5 parts, modified phenolic amine curing agent: 4 parts, barium sulfate: 11 parts, short-cut carbon fiber: 9 parts, hollow glass microspheres: 6 parts, bis-[γ-(triethoxysilyl)propyl] tetrasulfide: 3 parts, silicone defoamer: 2 parts, dispersant: 10 parts, fumed silica thickener: 1.5 parts, composite coating anti-aging agent: 7 parts;

[0101] The specific preparation method of the composite coating anti-aging agent is as follows:

[0102] Step 1: Dry the nano zinc oxide in a vacuum drying oven at 80°C for 4 hours to remove moisture, and then perform ultrafine grinding. Grind 4-hydroxybenzophenone, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole and a composite hindered amine light stabilizer in a ball mill respectively;

[0103] Step 2: Add acrylic resin to the reactor, add 6% ethyl acetate as a solvent, stir, and heat to 53°C. Add 4-hydroxybenzophenone, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole, composite hindered amine light stabilizer, nano zinc oxide, antioxidant and dispersant to the reactor, continue stirring, and add each addition every 15 minutes;

[0104] Step 3: Use an ultrasonic disperser to ultrasonically disperse the mixture in the reactor. During the ultrasonic process, the temperature is maintained at 50°C ± 2°C and the temperature is controlled by a circulating water bath.

[0105] Step 4: Remove the solvent from the ultrasonically dispersed mixture by vacuum distillation. The distillation temperature is controlled at 65°C and the vacuum degree is -0.09MPa. After the solvent is removed, the composite coating anti-aging agent is cooled to room temperature.

[0106] The specific preparation method of the composite hindered amine light stabilizer in step 1 is as follows:

[0107] Step A1: adding tetrahydrodicyclopentadienylamine and potassium carbonate catalyst to a reaction kettle, and reacting bromoalkane under nitrogen protection, controlling the reaction temperature at 85° C., and reacting for 7 hours. After the reaction, cooling, filtering, and washing are performed to obtain hindered amine compound A;

[0108] Step A2: adding hydrogen siloxane and tetramethylpiperidinamine derivative into a reaction vessel, adding chloroplatinic acid catalyst, heating and stirring, and reacting at 65° C. for 5 hours to obtain hindered amine compound B;

[0109] Step A3: First, add the carrier resin phenolic modified epoxy resin to the mixer and start stirring at 900 rpm. Then, add antioxidant 1010, triazine derivative, and polyethylene wax in sequence and mix for 17 minutes. Then, reduce the stirring speed to 550 rpm and sequentially add hindered amine compound A and hindered amine compound B. After the addition is complete, increase the stirring speed to 1350 rpm and continue stirring for 35 minutes.

[0110] Step A4: The uniformly mixed material is extruded and granulated through a twin-screw extruder. The extruded material is cooled and pelletized to obtain composite hindered amine light stabilizer particles.

[0111] The composite coating anti-aging agent includes the following components by weight: 13 parts of 4-hydroxybenzophenone, 13 parts of 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole, 19 parts of hindered amine light stabilizer, 15 parts of nano zinc oxide, 40 parts of acrylic resin, 2 parts of antioxidant, and 1.2 parts of dispersant.

[0112] A method for preparing a high-temperature resistant metal surface coating comprises the following steps:

[0113] Step S1: ceramic silicone resin, polyethersulfone modified organic fluorine resin and water-based polyimide resin are placed in a reactor and heated to 45°C, and stirred at 150 rpm for 30 minutes to obtain a mixed resin A; boron nitride, barium sulfate and chopped carbon fibers are placed in a vacuum drying oven, dried, and then ground using a grinding device, filtered and set aside; hollow glass microspheres are preheated at 90°C for 1.5 hours;

[0114] Step S2: In a reactor equipped with a high-speed disperser, a heating device, and a temperature control, monitoring, and speed regulation system, xylene and n-butanol are mixed in a volume ratio of 3:1 to obtain a solvent, and the boron nitride, barium sulfate, chopped carbon fibers, and hollow glass microspheres pretreated in step S1 are added, along with a dispersant;

[0115] Step S3: pouring the mixed resin A pretreated in step S1 into the reactor;

[0116] Step S4: In a reaction kettle, add bis-[γ-(triethoxysilyl)propyl]tetrasulfide, an organosilicon defoamer, and a composite coating anti-aging agent in sequence, and finally add a fumed silica thickener, and stir to obtain a high-temperature resistant metal surface coating.

[0117] In a third embodiment, the present invention provides a technical solution: a high-temperature resistant metal surface coating, characterized in that it includes the following components by weight: ceramic silicone resin: 60 parts, polyethersulfone modified organic fluorine resin: 30 parts, water-based polyimide resin: 10 parts, zinc chrome yellow: 15 parts, boron nitride: 6 parts, modified phenolic amine curing agent: 5 parts, barium sulfate: 15 parts, short-cut carbon fiber: 10 parts, hollow glass microspheres: 8 parts, bis-[γ-(triethoxysilyl)propyl] tetrasulfide: 4 parts, silicone defoamer: 3 parts, dispersant: 12 parts, fumed silica thickener: 2 parts, composite coating anti-aging agent: 9 parts;

[0118] The specific preparation method of the composite coating anti-aging agent is as follows:

[0119] Step 1: Dry the nano zinc oxide in a vacuum drying oven at 80°C for 4 hours to remove moisture, and then perform ultrafine grinding. Grind 4-hydroxybenzophenone, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole and a composite hindered amine light stabilizer in a ball mill respectively;

[0120] Step 2: Add acrylic resin to the reactor, add 8% ethyl acetate as a solvent, stir, and heat to 55°C. Add 4-hydroxybenzophenone, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole, composite hindered amine light stabilizer, nano zinc oxide, antioxidant and dispersant to the reactor, continue stirring, and add each addition for 15 minutes;

[0121] Step 3: Use an ultrasonic disperser to ultrasonically disperse the mixture in the reactor. During the ultrasonic process, the temperature is maintained at 50°C ± 2°C and the temperature is controlled by a circulating water bath.

[0122] Step 4: Remove the solvent from the ultrasonically dispersed mixture by vacuum distillation. The distillation temperature is controlled at 70°C and the vacuum degree is -0.1MPa. After the solvent is removed, the composite coating anti-aging agent is cooled to room temperature.

[0123] The specific preparation method of the composite hindered amine light stabilizer in step 1 is as follows:

[0124] Step A1: adding tetrahydrodicyclopentadienylamine and potassium carbonate catalyst to a reaction kettle, and reacting bromoalkane under nitrogen protection, controlling the reaction temperature at 90° C., reacting for 8 hours, and cooling, filtering, and washing to obtain hindered amine compound A;

[0125] Step A2: adding hydrogen siloxane and tetramethylpiperidinamine derivative into a reaction vessel, adding chloroplatinic acid catalyst, heating and stirring, and reacting at 70° C. for 6 hours to obtain hindered amine compound B;

[0126] Step A3: First, add the carrier resin phenolic modified epoxy resin to the mixer and start stirring at 1000 rpm. Then, add antioxidant 1010, triazine derivative, and polyethylene wax in sequence and mix for 20 minutes. Then, reduce the stirring speed to 600 rpm, and then add hindered amine compound A and hindered amine compound B in sequence. After the addition is complete, increase the stirring speed to 1500 rpm and continue stirring for 40 minutes.

[0127] Step A4: The uniformly mixed material is extruded and granulated through a twin-screw extruder. The extruded material is cooled and pelletized to obtain composite hindered amine light stabilizer particles.

[0128] The composite coating anti-aging agent includes the following components by weight: 15 parts of 4-hydroxybenzophenone, 14 parts of 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole, 20 parts of hindered amine light stabilizer, 16 parts of nano zinc oxide, 45 parts of acrylic resin, 2.5 parts of antioxidant, and 1.6 parts of dispersant.

[0129] A method for preparing a high-temperature resistant metal surface coating comprises the following steps:

[0130] Step S1: ceramic silicone resin, polyethersulfone modified organic fluorine resin and water-based polyimide resin are placed in a reactor and heated to 50°C, and stirred at 200 rpm for 30 minutes to obtain a mixed resin A; boron nitride, barium sulfate and chopped carbon fibers are placed in a vacuum drying oven, dried, and then ground using a grinding device, filtered and set aside; hollow glass microspheres are preheated at 100°C for 2 hours;

[0131] Step S2: In a reactor equipped with a high-speed disperser, a heating device, and a temperature control, monitoring, and speed regulation system, xylene and n-butanol are mixed in a volume ratio of 3:1 to obtain a solvent, and the boron nitride, barium sulfate, chopped carbon fibers, and hollow glass microspheres pretreated in step S1 are added, along with a dispersant;

[0132] Step S3: pouring the mixed resin A pretreated in step S1 into the reactor;

[0133] Step S4: In a reaction kettle, add bis-[γ-(triethoxysilyl)propyl]tetrasulfide, an organosilicon defoamer, and a composite coating anti-aging agent in sequence, and finally add a fumed silica thickener, and stir to obtain a high-temperature resistant metal surface coating.

[0134] The high temperature resistance performance testing method of the high temperature resistant metal surface coating prepared in the above embodiments includes the following contents:

[0135] The first step is thermogravimetric analysis. Place the metal specimen coated with the coating into the sample cell of the thermogravimetric analyzer and test it under a nitrogen atmosphere. Set the heating rate to 10°C / min and the temperature range to 30-800°C. Record the weight change of the sample during the heating process, focusing on observing the starting decomposition temperature, decomposition rate and the remaining weight percentage at the target high temperature. The higher the starting decomposition temperature, the slower the decomposition rate and the higher the remaining weight percentage at the target high temperature, the better the high temperature resistance of the coating.

[0136] The second step is high-temperature hardness test. The metal specimen coated with the coating is placed in a high-temperature furnace. The temperature gradient of the high-temperature furnace is set to 200℃, 400℃, 600℃, and 800℃. After the temperature stabilizes at the set value, a high-temperature hardness tester or Rockwell hardness tester is used to test the hardness of the coating surface. Measure 5 times at each temperature point and take the average value. Record the change of hardness value with temperature. The smaller the decrease in hardness value at high temperature, the better the structural stability of the coating at high temperature and the stronger the high-temperature resistance.

[0137] The anti-aging performance testing method of the high-temperature resistant metal surface coating prepared in the above embodiments includes the following contents:

[0138] The coated samples were placed in a xenon lamp aging test chamber, set at a light intensity of 0.55W / m²・nm at a wavelength of 340nm, a blackboard temperature of 63°C, a relative humidity of 50%, and a rainfall cycle of 18 minutes of water spray every 120 minutes. Samples were removed every 200 hours and observed for changes in the coating surface, such as color change, chalking, and cracking. The gloss change of the coating surface was measured using a gloss meter, color change using a colorimeter, and adhesion change using an adhesion tester. If the gloss decreases slightly with increasing aging time, the color change is minimal, and adhesion remains good, then the coating has excellent anti-aging properties.

[0139] The anti-corrosion performance testing method of the high temperature resistant metal surface coating prepared in the above embodiments includes the following contents:

[0140] Place the treated specimens in a salt spray chamber and conduct salt spray testing according to the test cycle specified in the standard (e.g., 240 hours, 480 hours, 720 hours, etc.). After the test, remove the specimens, rinse them with clean water, and observe the coating surface for signs of corrosion (e.g., rust, blistering, flaking, etc.). The coating's corrosion resistance is evaluated based on the degree of corrosion (e.g., the percentage of the corrosion area to the total area). Alternatively, electrochemical impedance spectroscopy (EIS) can be performed on the specimens using an electrochemical workstation. By analyzing the impedance spectrum, the coating's protective performance can be evaluated. Higher impedance values indicate better corrosion resistance.

[0141] The performance comparison chart of the metal surface coatings prepared in the above three embodiments is as follows:

[0142]

[0143] The high-temperature resistant anti-corrosion coating in the above chart is a common high-temperature resistant anti-corrosion coating on the market. According to the above test results, the coating prepared in this case has good performance in high-temperature resistance, aging resistance and corrosion resistance, and the metal surface coating prepared according to the preparation process in Example 3 has better performance in all aspects.

[0144] Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field and related fields without making creative efforts should fall within the scope of protection of the present invention. Structures, devices, and operating methods not specifically described and explained in the present invention shall be implemented in accordance with conventional means in the field unless otherwise specified or limited.

Claims

1. A high temperature resistant metal surface coating, characterized in that: The invention comprises the following components by weight: ceramic silicone resin: 40-60 parts, polyethersulfone modified organic fluorine resin: 20-30 parts, water-based polyimide resin: 8-10 parts, zinc chrome yellow: 10-15 parts, boron nitride: 4-6 parts, modified phenolic amine curing agent: 3-5 parts, barium sulfate: 8-15 parts, chopped carbon fiber: 8-10 parts, hollow glass microspheres: 5-8 parts, silane coupling agent: 2-4 parts, organic silicon defoaming agent: 1-3 parts, dispersant: 8-12 parts, thickener: 1-2 parts, composite coating anti-aging agent: 6-9 parts; The specific preparation method of the composite coating anti-aging agent is as follows: Step 1: Dry the nano zinc oxide in a vacuum drying oven to remove moisture, and then perform ultrafine grinding treatment, and grind 4-hydroxybenzophenone, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole and a composite hindered amine light stabilizer in a ball mill respectively; Step 2: Add acrylic resin to a reactor, add 5%-8% ethyl acetate as a solvent, stir, add 4-hydroxybenzophenone, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole and composite hindered amine light stabilizer, nano zinc oxide, antioxidant and dispersant treated in step 1 to the reactor, and continue stirring; Step 3: Using an ultrasonic disperser to perform ultrasonic dispersion treatment on the mixture in the reactor; Step 4: removing the solvent from the ultrasonically dispersed mixture by vacuum distillation, and cooling the mixture to room temperature to obtain a composite coating anti-aging agent; The silane coupling agent is bis-[γ-(triethoxysilyl)propyl]tetrasulfide, and the thickener is fumed silica thickener; The specific preparation method of the composite hindered amine light stabilizer in step 1 is as follows: Step A1: adding tetrahydrodicyclopentadienylamine and potassium carbonate catalyst into a reaction kettle, and bromoalkane under nitrogen protection. After the reaction is completed, cooling, filtering and washing are performed to obtain hindered amine compound A; Step A2: adding hydrogen siloxane and tetramethylpiperidinamine derivative into a reaction vessel, adding chloroplatinic acid catalyst, heating and stirring to obtain hindered amine compound B; Step A3: First, add the carrier resin phenolic modified epoxy resin into the mixer, start stirring, add antioxidant 1010, ultraviolet absorber and dispersant in sequence, and then add hindered amine compound A and hindered amine compound B in sequence. After the addition is completed, continue stirring; Step A4: The uniformly mixed material is extruded and granulated through a twin-screw extruder. The extruded material is cooled and pelletized to obtain composite hindered amine light stabilizer particles.

2. A high temperature resistant metal surface coating according to claim 1, characterized in that: The ultraviolet absorber in step A3 is a triazine derivative, and the dispersant in step A3 is polyethylene wax.

3. The high temperature resistant metal surface coating according to claim 1, characterized in that: The composite coating anti-aging agent comprises the following components by weight: 12-15 parts of 4-hydroxybenzophenone, 12-14 parts of 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole, 18-20 parts of hindered amine light stabilizer, 14-16 parts of nano zinc oxide, 35-45 parts of acrylic resin, 1-2.5 parts of antioxidant, and 0.8-1.6 parts of dispersant.

4. The method for preparing a high temperature resistant metal surface coating according to claim 3, characterized in that: The method comprises the following preparation steps: Step S1: ceramic silicone resin, polyethersulfone modified organic fluorine resin and water-based polyimide resin are placed in a reactor, heated and stirred to obtain a mixed resin A; boron nitride, barium sulfate and short carbon fibers are placed in a vacuum drying oven, dried, and then ground using a grinding device, filtered and set aside; hollow glass microspheres are preheated; Step S2: In a reactor equipped with a high-speed disperser, a heating device, and a temperature control, monitoring, and speed regulation system, xylene and n-butanol are mixed in a volume ratio of 3:1 to obtain a solvent, and the boron nitride, barium sulfate, chopped carbon fibers, and hollow glass microspheres pretreated in step S1 are added, along with a dispersant; Step S3: pouring the mixed resin A pretreated in step S1 into the reactor; Step S4: In a reaction kettle, a silane coupling agent, an organosilicon defoaming agent, and a composite coating anti-aging agent are sequentially added, and finally a thickener is added, and the mixture is stirred to obtain a high-temperature resistant metal surface coating.

5. The method for preparing a high temperature resistant metal surface coating according to claim 4, characterized in that: The total amount of the mixed solvent of toluene and n-butanol in step S2 is 15-20% of the total amount of the resin.

6. The method for preparing a high temperature resistant metal surface coating according to claim 4, characterized in that: The temperature control, monitoring and speed regulation system in step S2 has the following control method: Step 1: Initialize the system and set the temperature control parameters and speed control parameters; Step 2: Preheating of hollow glass microspheres; Step 3: Filler addition and high-speed dispersion.

7. The method for preparing a high-temperature resistant metal surface coating according to claim 6, characterized in that: The working process of the heating device control system in the second step is as follows: Step B1: During the heating process, a high-precision temperature sensor monitors the temperature of the solvent and material mixture system in the reactor. The temperature sensor transmits the real-time collected temperature data to the controller in the form of an electrical signal. After receiving the temperature data, the controller processes and analyzes it and compares the actual temperature with the set target temperature range; Step B2: When the actual temperature is lower than the lower limit of the target temperature, the controller issues a command to increase the heating power. The heating device may use a resistance wire heating method, and the controller adjusts the heating power. Step B3: When the temperature reaches the target temperature range, the heating device control system enters the temperature maintenance stage, during which the controller monitors the temperature change and fine-tunes the heating power; Step B4: The temperature sensor acts as a feedback element to feed back the temperature information in the reactor to the controller in real time. The controller compares the temperature feedback data with the set temperature and calculates the temperature deviation. If the temperature deviation exceeds ±2°C, the controller adjusts the heating power.

8. The method for preparing a high-temperature resistant metal surface coating according to claim 7, characterized in that: The algorithm preset by the controller in step B2 is as follows: The temperature range of the entire heating process is divided into multiple intervals. Assuming the lower limit of the target temperature is T1 and the upper limit is T2, the intervals can be divided as follows; Low temperature range: T0 to T1- T1; Medium temperature range: T1- T1 to T2- T2; High temperature range: T2- T2 to T2; In the low temperature range, the initial heating power is set to P0, and the heating power in this range increases by P1, that is, the first heating power is adjusted to P0+ P1, the second heating power is adjusted to P0+2 P1; In the medium temperature range, if the temperature rises by 1℃, the increase of heating power will decrease. P2, when the temperature changes from T1- When T1 starts to rise, the heating power increases by = P1- P2; As the temperature continues to rise, let the current temperature be T, T1- T1<T<T2- T2, heating power increase The calculation formula is = P1- P2 (T-(T1- T1)); In the high temperature range, when the temperature enters the high temperature range, the increase in heating power is very small and approaches zero. When the temperature reaches T2- At T2, the increase in heating power decreases to P3; At temperatures from T2- T2 rises to T2, let the current temperature be T, T2- T2<T<T2, heating power increase Further reduce, The calculation formula is = P3- P4 (T-(T2- T2)), where P4 is the amplitude value that is further reduced in the high temperature range.

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