High-temperature-resistant fireproof coating and preparation method thereof

Abstract

The invention relates to the technical field of coatings, and discloses a high-temperature-resistant fireproof coating and a preparation method thereof.The preparation method comprises the steps that a basic fireproof layer, a temperature discoloration early warning layer, a temperature memory delay display assembly, an ultraviolet accumulation monitoring layer and a signal differentiation display assembly are prepared, and the functional layers are fused through a technological method. According to the invention, the temperature memory effect of compounding the phase change microcapsule and the photosensitive memory material and the ultraviolet monitoring component packaged by the selective transmission material are introduced, so that the historical recording function that the fireproof coating still keeps the color change state for 24-72 hours after the temperature falls back and the differential display function of temperature abnormity and ultraviolet accumulation are realized; the technical problems that a traditional fireproof coating is single in function and lacks historical recording capacity are effectively solved.

Description

Technical Field

[0001] The present invention relates to the technical field of coatings, and more specifically, it relates to a high-temperature resistant and fireproof coating and a preparation method thereof. Background Art

[0002] Currently, the high-temperature resistant and fireproof coatings on the market mainly focus on the basic fireproof and heat insulation performance. Although some products have begun to introduce the function of temperature color change warning, there are still the following technical defects: 1) Traditional high-temperature resistant and fireproof coatings lack an effective warning function and cannot provide a warning signal in time when the temperature reaches the dangerous threshold; 2) Existing thermochromic fireproof coatings will immediately return to their original colors after the temperature drops, and cannot maintain the color-changing state for post-event inspection and traceability, resulting in the inability to determine whether the equipment or structure has ever experienced a dangerous temperature; 3) Traditional fireproof coatings cannot monitor the aging degree of materials under long-term ultraviolet irradiation. Specifically, fireproof coatings used outdoors cannot visually show whether their protective performance has decreased due to ultraviolet radiation; 4) Existing fireproof coatings lack the ability to monitor multiple hazards and cannot simultaneously respond to and record changes in multiple environmental parameters such as temperature anomalies and ultraviolet intensity; 5) Traditional fireproof coatings have a single function and lack the ability to record and display the historical conditions of the use environment, making it difficult to provide a visual monitoring basis for equipment safety management. Summary of the Invention

[0003] The present invention provides a high-temperature resistant and fireproof coating and a preparation method thereof, which solve the technical problems in the related art.

[0004] The present invention provides a high-temperature resistant and fireproof coating and a preparation method thereof, including the following components: a basic fireproof layer, a temperature color change warning component, a temperature memory delay display component, an ultraviolet cumulative monitoring component, and a signal differentiation display component; the temperature memory delay display component contains a composite of phase change microcapsules and a photosensitive memory material, which can make the coating maintain the color-changing state for 24 - 72 hours after the temperature drops; the ultraviolet cumulative monitoring component contains an ultraviolet-sensitive material encapsulated by a selectively permeable material; the signal differentiation display component presents the temperature memory display and the ultraviolet cumulative display in different colors.

[0005] Preferably: The basic fireproof layer is composed of inorganic silicate, phosphate refractory materials, and an inorganic binder, wherein the weight ratio of inorganic silicate to phosphate refractory materials is 60 - 75:25 - 40, and the addition amount of the inorganic binder is 5 - 10% of the total weight.

[0006] Preferably, the temperature color-changing warning component contains a thermosensitive color-changing material which undergoes a visible color change at 150 ± 5 °C. The thermosensitive color-changing material is selected from ferrite-based or vanadate-based color-changing materials and is surface-modified with a silane coupling agent.

[0007] Preferably, the phase change microcapsules in the temperature memory delay display component contain a phase change material with a melting point of 150 - 170 °C as the core and a wall material as the coating layer; the phase change material is selected from one or more of octadecane, paraffin wax, or stearic acid; the wall material is a mixture of gelatin or gum arabic and polyvinyl alcohol.

[0008] Preferably, the photosensitive memory material in the temperature memory delay display component is a spiropyran compound and is loaded through a polymethyl methacrylate carrier.

[0009] Preferably, the ultraviolet-sensitive material in the ultraviolet cumulative monitoring component is selected from one or several of benzidine yellow, azo compounds, or titanium dioxide / cerium oxide composites; the selective transmission material is a cross-linked product of polymethylsiloxane and tetraethoxysilane.

[0010] Preferably, the signal differentiation display component makes the temperature memory display orange-red and the ultraviolet cumulative display blue.

[0011] Preferably, the mass percentages of each component in the coating are: basic fireproof layer 60 - 80%, temperature color-changing warning component 5 - 15%, temperature memory delay display component 8 - 15%, ultraviolet cumulative monitoring component 3 - 8%, and other additives 1 - 5%.

[0012] A preparation method of a high-temperature resistant fireproof coating includes the following steps: Prepare the basic fireproof component, mix inorganic silicate and phosphate refractory materials, add an inorganic binder, and stir to form a basic fireproof slurry; Prepare the thermosensitive color-changing material, perform surface modification on the thermosensitive color-changing material, and mix it with a part of the basic fireproof slurry to form a pre-dispersed slurry; Prepare the temperature memory component, including preparing phase change microcapsules and preparing a photosensitive memory material, and compounding the two to form a temperature memory component slurry; Prepare the ultraviolet monitoring component, including selecting an ultraviolet-sensitive material, preparing a selective transmission shell material, encapsulating through interfacial polymerization to form ultraviolet-sensitive microcapsules, and preparing a pre-dispersed slurry; Multi-component fusion, mix the temperature memory component slurry and the ultraviolet monitoring component slurry to form a functional component mixed slurry, and mix it with the basic fireproof slurry and the thermosensitive color-changing pre-dispersed slurry to obtain the final multi-functional high-temperature resistant fireproof coating.

[0013] Preferably, the preparation of the phase change microcapsules includes: dissolving the phase change material in an organic solvent to form an oil phase; dissolving the wall material in an aqueous phase; adding the oil phase to the aqueous phase under stirring to form an O / W emulsion; adding a crosslinking agent for reaction; removing the organic solvent, washing, filtering, and drying to obtain the phase change microcapsules.

[0014] Preferably, the preparation of the photosensitive memory material includes: dissolving the spiropyran compound in dichloromethane; adding polymethyl methacrylate as a carrier, with the mass ratio of the photosensitive material:PMMA = 1:5 - 1:10; evaporating the solvent after stirring and dissolving to obtain a thin film; pulverizing the thin film and passing it through a 60 - 100 mesh sieve to obtain the photosensitive memory material powder.

[0015] Preferably, the preparation of the ultraviolet - sensitive microcapsules includes: dispersing the ultraviolet - sensitive material in polyethylene glycol or epoxy resin to form a core material; dispersing the core material in an aqueous phase by interfacial polymerization; adding a selectively permeable shell material prepolymer solution for reaction; adjusting the pH to complete cross - linking; filtering, washing, and drying to obtain the ultraviolet - sensitive microcapsules.

[0016] Preferably, the process of multi - component fusion includes: Mixing the temperature - memory component slurry and the ultraviolet - monitoring component slurry in a mass ratio of 1:1 - 2:1, adding a compatibilizer and a pigment stabilizer to form a functional component mixed slurry; Mixing the basic fire - proof slurry and the thermochromic pre - dispersed slurry in a mass ratio of 8:1 - 10:1 to form a fire - proof and color - changing base slurry; Mixing the fire - proof and color - changing base slurry and the functional component mixed slurry in a mass ratio of 3:1 - 5:1, adding a leveling agent and a thixotropic agent, and stirring to obtain the final coating.

[0017] Preferably, add 0.5 - 2% of an ultraviolet absorber, 0.5 - 2% of an antioxidant, 1 - 5% of a toughening agent, or 0.5 - 2% of an antibacterial and antifungal agent to the final coating.

[0018] An application method of a high - temperature resistant and fire - proof coating includes surface cleaning treatment, stirring the coating, construction, and drying and curing steps. The brushing, rolling, or spraying method is adopted, and the wet film thickness is 300 - 500 μm, forming a fire - proof protective layer on the surfaces of power equipment, chemical equipment, metallurgical equipment, building structures, or outdoor facilities, and simultaneously realizing the visual monitoring of temperature anomalies and ultraviolet accumulation.

[0019] The beneficial effects of the present invention are as follows: The coating in the present invention can provide fire protection for more than 240 minutes in a high - temperature environment of 1100 °C, fully meeting the Class A fire - proof requirements. At a standard thickness of 25 mm, the back - side temperature does not exceed 180 °C, and the thermal conductivity is < 0.25 W / (m·K).

[0020] When the paint reaches the dangerous temperature of 150±5°C, its color rapidly changes from light yellow to orange - red. The discoloration response time is less than 30 seconds, and the discoloration area coverage rate > 95%, providing users with timely visual warnings of abnormal temperatures.

[0021] After the paint has experienced high temperatures, the color change can be maintained for 24 - 72 hours. Even if the temperature has returned to normal, it can clearly show that the equipment or structure has once experienced dangerous temperatures, providing intuitive evidence for post - incident safety inspections and accident analysis.

[0022] The paint can gradually change its color according to the cumulative ultraviolet radiation dose, changing from green to blue. The degree of color change has a linear relationship with the cumulative ultraviolet dose (R²>0.95), and can be used to monitor the paint life and environmental UV intensity, especially suitable for monitoring the use status of fire - proof materials in outdoor environments.

[0023] The paint uses different regions or different colors to display changes in different environmental parameters. The temperature memory is displayed in orange - red, and the ultraviolet accumulation is displayed in blue, enabling users to visually distinguish different environmental conditions experienced by the paint and avoiding information confusion.

[0024] The paint realizes the synergistic effect of multiple functions such as fire - proofing, temperature warning, temperature history recording, and ultraviolet accumulation monitoring. Each functional component does not interfere with each other, providing an integrated solution for industrial safety and building fire - proofing, and reducing the installation and maintenance costs of multiple safety detection devices.

[0025] The paint has good construction performance and is suitable for various construction methods such as brushing, rolling, or spraying; the cured coating has strong adhesion (≥5MPa), good weather resistance, and the performance attenuation is <10% after salt spray, damp heat, and freeze - thaw cycle tests; each functional index remains stable in the temperature range of - 40°C to +80°C.

[0026] The paint uses water as the dispersion medium, with a VOC content <50g / L, meeting the requirements of environmental - friendly paints; it does not contain harmful heavy metals such as lead, mercury, and cadmium, is environmentally friendly; and does not release harmful substances after curing, meeting the indoor environmental protection requirements.

[0027] Through the introduction of a temperature - memory delay display component that combines phase - change microcapsules and photosensitive memory materials, and an ultraviolet - accumulation monitoring component encapsulated with a selective - transmission material, the present invention realizes a comprehensive upgrade of the functions of fire - proof paints, effectively solving the technical problems of single - function and lack of historical - recording ability in traditional fire - proof paints. Description of the Drawings

[0028] Figure 1 are the test results of the fire - resistance performance and heat - conduction performance of the fire - proof paint in the present invention; Figure 2 are the comprehensive test results of the temperature - warning function and temperature - memory function in the present invention; Figure 3 are the CIE Lab* chromaticity change data of the temperature warning function in the present invention; Figure 4 is the comprehensive test result of the ultraviolet cumulative monitoring function in the present invention; Figure 5 are the CIE Lab* chromaticity change data of the ultraviolet irradiation in the present invention; Figure 6 is the comprehensive test of the signal differentiation display effect in the present invention; Figure 7 is the test result of the cooperative effect of the multifunctional components in the present invention; Figure 8 is the comprehensive test result of the practicability and adaptability in the present invention; Figure 9 is the test result of the environmental protection performance of the coating in the present invention. Detailed implementation manners

[0029] The subject matter described herein will now be discussed with reference to example embodiments. It should be understood that discussing these embodiments is only to enable those skilled in the art to better understand and thus implement the subject matter described herein, and the functions and arrangements of the elements discussed can be changed without departing from the scope of protection of the content of this specification. Each example can omit, substitute, or add various processes or components as needed. Additionally, the features described in some examples can also be combined in other examples.

[0030] In at least one embodiment of the present invention, a preparation method of a high-temperature resistant and fireproof coating is disclosed, including the following steps: 1. Preparation of basic fireproof components Mix an inorganic silicate and a phosphate refractory material in a weight ratio of 60 - 75:25 - 40, and add 5 - 10% of an inorganic binder (aluminum oxide sol or water glass), and stir for 30 - 60 minutes under a stirring speed of 500 - 700 rpm to obtain a uniform basic fireproof slurry. This basic fireproof component provides the basic fireproof and heat insulation function of the coating and serves as a carrier for the subsequent functional components.

[0031] Optional material combinations include: Inorganic silicate: one or more of calcium silicate, aluminum silicate, and zirconium silicate; Phosphate: one or more of ammonium polyphosphate, ammonium dihydrogen phosphate, and aluminum phosphate; Inorganic binder: one or more of aluminum oxide sol, water glass, and borate.

[0032] To ensure the rheology and construction performance of the slurry, 2 - 5% of a rheology aid, such as cellulose ether or polyvinyl alcohol, can be added.

[0033] 2. Treatment of thermochromic materials The purpose of this step is to prepare a warning component that can undergo an obvious color change at 150 °C and ensure its compatibility with the basic fireproof component. It includes the following processes: Select thermochromic materials, such as ferrite-based (Fe2O3·CoO, color change temperature is about 150 °C, changing from brown to black) or vanadate-based (NH4VO3, color change temperature is about 120 - 160 °C, changing from white to yellow and then to brownish red) color-changing materials.

[0034] Perform surface modification on the selected thermochromic materials to improve their thermal stability and compatibility with the matrix: a) Disperse the thermochromic materials in absolute ethanol at a mass ratio of 1:10; b) Add 3 - 8% of a silane coupling agent (such as KH-550, γ-aminopropyltriethoxysilane), and reflux at 60 - 70 °C for 2 - 4 hours; c) Filter and wash with absolute ethanol 3 times, and vacuum dry at 80 °C for 8 - 12 hours to obtain the surface-modified thermochromic materials.

[0035] Mix the modified thermochromic materials with a part of the basic fireproof slurry (about 5 - 10% of the total amount of the final coating) to prepare a thermochromic pre-dispersed slurry: a) Add the modified thermochromic materials to the basic fireproof slurry at an addition amount of 5 - 15%; b) Disperse with a high-speed disperser (2000 - 3000 rpm) for 30 - 60 minutes to form a uniform pre-dispersed slurry; c) Filter through a 100 - 200 mesh sieve to remove agglomerates and obtain the thermochromic pre-dispersed slurry.

[0036] Through the above treatment, the surface of the thermochromic materials is modified, obtaining better dispersibility and thermal stability, while maintaining its color-changing function at 150 °C, providing a material basis for the subsequent preparation of the temperature-changing warning layer.

[0037] 3. Preparation of temperature memory component This step prepares a temperature memory component that can keep the coating in a color-changing state for 24 - 72 hours after high temperature, which is one of the core technological innovations of the present invention. It specifically includes the following processes: Preparation of phase change microcapsules: a) Dissolve one or more of octadecane, paraffin wax, or stearic acid in an organic solvent (such as cyclohexane or n-hexane) at a mass ratio of 1:5 - 1:10 to form an oil phase; b) Dissolve gelatin (or gum arabic) and polyvinyl alcohol in deionized water at a ratio of 5:1 - 10:1 to form an aqueous phase; c) Under the condition that the stirring speed is 800 - 1200 rpm, slowly add the oil phase to the water phase to form an O / W type emulsion; d) Add 3 - 8% of a cross-linking agent (such as glutaraldehyde or formaldehyde) to the system and react at 35 - 45 °C for 2 - 4 hours; e) Remove the organic solvent by vacuum distillation, wash, filter, and dry to obtain phase change microcapsules with a melting point of 150 - 170 °C.

[0038] Preparation of photosensitive memory material: a) Dissolve a spiropyran compound (such as 1,3,3 - trimethyl - 6 - nitroindolylspiro[2,2']benzopyran) in dichloromethane at a concentration of 0.5 - 2%; b) Add polymethyl methacrylate (PMMA) as a carrier, with the mass ratio of photosensitive material:PMMA = 1:5 - 1:10; c) After stirring and dissolving evenly, slowly evaporate the solvent through a rotary evaporator to obtain a photosensitive memory material film; d) Crush the film and pass it through a 60 - 100 mesh sieve to obtain photosensitive memory material powder.

[0039] Preparation of temperature memory composite material: a) Mix the phase change microcapsules and the photosensitive memory material powder at a mass ratio of 2:1 - 4:1; b) Add 1 - 3% of a dispersant (such as polyvinylpyrrolidone or sodium dodecyl sulfate), and disperse it in an ultrasonic disperser (power 300 - 500 W) for 10 - 20 minutes; c) Mix the dispersed mixture with a basic fire - resistant slurry accounting for 8 - 15% of the total final coating, and stir at 300 - 500 rpm for 30 - 60 minutes to obtain a temperature memory component slurry.

[0040] The temperature memory component prepared in this step realizes the key function of the present invention: when the temperature rises to 150 - 170 °C, the phase change microcapsules melt, react with the photosensitive memory material to form a stable colored substance, and still maintain the discolored state for 24 - 72 hours after the temperature drops, and can only return to the original state under light of a specific wavelength.

[0041] 4. Preparation of ultraviolet monitoring component This step prepares a component that can cumulatively record the ultraviolet radiation intensity, enabling the coating to have the function of monitoring the cumulative amount of environmental ultraviolet rays. The specific process is as follows: Selection of ultraviolet - sensitive materials: a) Select an organic dye or a titanium / cerium - based inorganic photosensitive material sensitive to ultraviolet rays, such as benzidine yellow, azo compounds, or titanium dioxide / cerium oxide composites; b) For organic dyes, add 1-5% of light stabilizers (such as hydroxybenzotriazole or methylene bisbenzotriazole) to control their discoloration rate.

[0042] Preparation of selectively permeable shell material: a) Mix polydimethylsiloxane (PDMS) and tetraethoxysilane (TEOS) at a mass ratio of 3:1 - 5:1, and add 0.5 - 2% of a catalyst (dibutyltin dilaurate); b) Stir and react at 70 - 80 °C for 3 - 5 hours to obtain a prepolymer solution with selectively permeable properties; c) Cool the prepolymer solution to room temperature, add 0.5 - 1% of a crosslinking agent (such as benzoyl peroxide), and set aside.

[0043] Preparation of ultraviolet - sensitive microcapsules: a) Disperse the ultraviolet - sensitive material at a concentration of 1 - 5% in polyethylene glycol or epoxy resin to form a core material; b) Using the interfacial polymerization method, disperse the core material in the aqueous phase to form a stable emulsion; c) Slowly add the prepared selectively permeable shell material prepolymer solution, and stir and react at 35 - 45 °C for 4 - 6 hours; d) Adjust the pH to 7.0 - 8.0, and continue stirring for 2 - 3 hours to complete crosslinking; e) Filter, wash, and dry to obtain ultraviolet - sensitive microcapsules.

[0044] Preparation of ultraviolet - monitoring layer pre - dispersed slurry: a) Disperse the prepared ultraviolet - sensitive microcapsules at an addition amount of 3 - 8% in a basic fire - resistant slurry accounting for 5 - 10% of the total amount of the final coating; b) Add 1 - 3% of a dispersion stabilizer (such as sodium dodecylbenzenesulfonate or polyoxyethylene ether), and stir at 500 - 800 rpm for 30 - 45 minutes; c) Filter through a 100 - 200 - mesh sieve if necessary to obtain the ultraviolet - monitoring component pre - dispersed slurry.

[0045] The ultraviolet - monitoring component prepared in this step realizes the monitoring of the long - term cumulative effect of ultraviolet rays through the selectively permeable properties of the microcapsules, and through the selectively permeable characteristics of the shell material, ensures that the ultraviolet - sensitive material will not be interfered by other components in the coating, and responds to ultraviolet radiation alone. When the ultraviolet accumulation reaches a certain threshold, the color gradually changes from green to blue, and the degree of color change is proportional to the ultraviolet cumulative dose.

[0046] 5. Multi - component fusion In this step, the previously prepared functional components are orderly fused into one body to form a composite fire - resistant coating with multiple functions. Specifically, it includes the following processes: Formation of signal differential display component: a) Mix the temperature memory component slurry and the ultraviolet monitoring component slurry in a mass ratio of 1:1 - 2:1; b) Add 2 - 5% of compatibilizer (such as polyvinyl butyral), and stir for 30 - 60 minutes under the condition of 500 - 700 rpm; c) Add 1 - 3% of pigment stabilizer (such as polyvinylpyrrolidone or carboxymethyl cellulose), and continue to stir for 15 - 30 minutes to form the functional component mixed slurry.

[0047] Construction of multi - layer structure: a) Mix the remaining basic fire - proof slurry (about 60 - 70% of the total amount of the final coating) and the thermochromic pre - dispersed slurry in a mass ratio of 8:1 - 10:1 to form the fire - proof and color - changing base slurry; b) Mix the fire - proof and color - changing base slurry and the functional component mixed slurry in a mass ratio of 3:1 - 5:1, and simultaneously add 2 - 5% of leveling agent (such as silicone) and 1 - 3% of thixotropic agent (such as fumed silica); c) Stir for 30 - 60 minutes under the condition of 300 - 500 rpm to ensure that each component is fully mixed without interfering with each other, and obtain the final multi - functional high - temperature resistant fire - proof coating.

[0048] Performance adjustment (optional): a) According to the special requirements of the application environment, 0.5 - 2% of ultraviolet absorber (such as hydroxybenzophenone or benzotriazole compounds) and 0.5 - 2% of antioxidant (such as hindered phenols or hindered amines compounds) can be added; b) If it is necessary to improve the impact resistance of the coating, 1 - 5% of toughening agent (such as acrylate elastomer or styrene - butadiene - styrene triblock copolymer) can be added; c) For outdoor applications, 0.5 - 2% of antibacterial and mildew - proof agent (such as quaternary ammonium salts or isothiazolinone compounds) can be appropriately added.

[0049] Through the above - mentioned fusion process, each functional component acts synergistically. The fire - proof layer provides the basic heat - insulation and fire - proof function, the thermochromic layer provides instant temperature warning, the temperature memory component provides the temperature history recording function, and the ultraviolet monitoring component provides the long - term ultraviolet cumulative monitoring function. And through the signal differential display technology, the changes of different environmental parameters can be visually distinguished.

[0050] 6. Application method and effect verification Application method of the coating: a) Surface treatment: The surface to be protected should be clean, dry, free of oil, rust and loose materials; for metal surfaces, it is recommended to first apply a layer of anti - rust primer, and then apply this coating after drying (about 24 hours). b) Stirring: The coating should be fully stirred until it is in a uniform state before use. If necessary, 3 - 5% deionized water can be added to adjust the consistency. c) Application method: It can be applied by brushing, rolling or spraying. The recommended wet film thickness is 300 - 500μm. d) Drying and curing: It can reach the basic use strength after drying at room temperature (25℃) for 24 hours, and it takes 7 days to be fully cured. e) Number of coating layers: According to the fire protection grade requirements, 1 - 3 layers can be applied, and the interval time between layers is 24 hours.

[0051] Performance verification methods and results: a) Fire protection performance test: Test according to GB / T14907. At a high temperature of 1100℃, a 25mm thick coating can provide 240 minutes of fire protection and heat insulation performance, fully meeting the Class A fire protection requirements. b) Temperature warning function test: Place the test panel coated with this coating in a heating furnace with controllable temperature. When the temperature reaches 150 ± 5℃, the coating changes from the original light yellow to obvious orange - red. The color change response time is less than 30 seconds, and the color change area coverage rate > 95%. c) Temperature memory function test: After heating the coating to 150℃ and then taking it out, at room temperature, the coating remains in the color - changed state for 48 ± 4 hours. Irradiating the coating with a 365nm ultraviolet lamp for 15 - 30 minutes can restore the original color of the coating. d) Ultraviolet monitoring function test: Place the coating sample in an ultraviolet aging chamber (UV - A intensity is 0.89W / m²). After cumulative irradiation for 8 hours, the color of the coating starts to change from green to blue, and it completely turns blue after 72 hours. The color change has a good linear relationship with the cumulative UV dose (R² > 0.95). e) Durability test: After salt spray test (1000 hours), damp - heat cycle test (50 cycles) and freeze - thaw cycle test (30 cycles), there are no obvious cracking, peeling and blistering phenomena on the coating, and the attenuation of each functional index < 10%.

[0052] Additional steps: Process optimization and improvement methods Batch production process optimization: a) The large - scale preparation of phase - change microcapsules can adopt the high - shear emulsification + suspension polymerization process, and use an automated temperature control system to control the reaction temperature to improve the product stability and consistency. b) The preparation of photosensitive memory materials can adopt spray - drying technology to replace the traditional rotary evaporation process to improve production efficiency and the particle size uniformity of the product. c) The encapsulation of ultraviolet - sensitive microcapsules can adopt microfluidic technology to achieve precise control of the microcapsule size and improve the response sensitivity.

[0053] Formulation Adjustment for Different Application Scenarios: a) For high-temperature industrial environments (such as steel mills, power plants), the content of phase change microcapsules can be increased to 15 - 20% to improve the persistence of temperature memory; b) For outdoor building applications, the content of UV-sensitive components can be increased to 8 - 12%, and 3 - 5% of weather-resistant additives can be added; c) For flammable and explosive places, the proportion of the basic fireproof layer can be increased to 75 - 85%, and the temperature discoloration threshold can be appropriately reduced to 120 - 130 °C.

[0054] Quality Control and Detection Methods: a) Quality control of phase change microcapsules: Differential scanning calorimetry (DSC) is used to measure the phase change temperature and phase change enthalpy, and a laser particle size analyzer is used to measure the particle size distribution; b) Detection of photosensitive memory materials: An ultraviolet-visible spectrophotometer is used to measure the change in the absorption spectrum, and a fluorescence lifetime detector is used to evaluate the stability of the memory materials; c) Detection of UV-sensitive microcapsules: A solar simulator and a color difference meter are used to calibrate the UV response curve.

[0055] Through the above process optimization and quality control measures, the stability and consistency of product performance can be further improved, the application scope can be expanded, and the fire safety requirements of different scenarios can be met.

[0056] Experimental Verification and Test Results To verify the various functions and performance indicators of the multifunctional high-temperature resistant fireproof coating of the present invention, we conducted tests. The following is a summary and analysis of the test results. The detailed data and test methods have been archived for future reference.

[0057] 1. Basic Fireproof Performance Test Test Purpose: To verify the fireproof and heat insulation performance of the coating in a high-temperature environment and confirm whether it meets the Class A fireproof requirements.

[0058] Test Results: See Figure 1 Test results of the fire resistance and heat conduction performance of the fireproof coating.

[0059] Result Analysis: The fireproof coating of the present invention can provide fire protection for more than 240 minutes when the thickness is 25 mm, fully meeting the Class A fireproof requirements. The temperature on the back of the coating always remains below 180 °C, and the average heat conduction coefficient is 0.23 W / (m·K), showing excellent heat insulation performance. After the high-temperature test, the coating still remains basically intact, only with slight carbonization on the surface, indicating good structural stability.

[0060] 2 Temperature Warning and Memory Function Test Test Purpose: To verify the temperature discoloration warning performance of the coating and the color retention ability after high temperature.

[0061] Test results: See Figure 2 Comprehensive test results of temperature warning function and temperature memory function; See Figure 3 CIELab* chromaticity change data of temperature warning function.

[0062] Result analysis: The temperature warning function of this coating performs excellently. It starts to change color significantly at an average temperature of 147.8 °C, with a response time of only 27.2 seconds and a color change area coverage rate as high as 96.9%. The temperature memory function is durable and effective. After 48 hours, the color difference retention rate still reaches 77.4%, and the performance attenuation is less than 7% after 10 cycles of use. The coating color changes from light yellow to orange-red, with a color difference as high as 33.0, far exceeding the human eye recognition threshold, providing a clear visual warning.

[0063] 3 Ultraviolet cumulative monitoring function test Test purpose: To verify the response performance of the coating to cumulative ultraviolet irradiation and evaluate the sensitivity and stability of the ultraviolet monitoring component.

[0064] Test results: See Figure 4 Comprehensive test results of ultraviolet cumulative monitoring function; See Figure 5 CIE Lab* chromaticity change data of ultraviolet irradiation.

[0065] Result analysis: The ultraviolet cumulative monitoring function of this coating performs outstandingly. It can systematically change from green to dark blue with the increase of cumulative ultraviolet dose. The color difference has an excellent linear relationship with the ultraviolet dose (R² = 0.968), and still maintains 98.8% of the functional performance in a high-temperature environment of 150 °C, showing excellent selectivity and anti-interference ability. The ultraviolet cumulative memory stability is excellent, and the color difference still remains 96.5% after 28 days, suitable for long-term environmental monitoring.

[0066] 4 Signal differential display and multi-function synergy effect test Test purpose: To verify whether the coating can display the changes of two environmental parameters, temperature anomaly and ultraviolet accumulation, in different colors at the same time, and evaluate the performance stability of the multi-function component under coexisting conditions.

[0067] Test results: See Figure 6 Comprehensive test of signal differential display effect.

[0068] See Figure 7 Test results of multi-function component synergy effect.

[0069] Result analysis: The coating has successfully achieved differential signal display. Temperature anomalies and ultraviolet accumulation can be simultaneously displayed in significantly different colors (orange-red vs dark blue), with an average recognition accuracy rate of 92.8%. The multifunctional components maintain good performance after being integrated into the same coating system, and the retention rates of each functional component are all above 90%. After 365 days of long-term storage and 20 cycles of use, each functional component still maintains good performance, indicating that there is little mutual influence among the multifunctional components and a good synergistic effect has been achieved.

[0070] 5. Practicality and Environmental Friendliness Tests Test purpose: To verify the applicability of the coating under different environmental conditions and on different substrates, and to evaluate its construction characteristics, adhesion, and environmental performance.

[0071] Test results: See Figure 8 Comprehensive test results of practicality and adaptability; See Figure 9 Test results of the environmental performance of the coating.

[0072] Result analysis: This coating has excellent practical performance, is suitable for various construction methods, has strong adhesion on metal substrates (>6 MPa), good weather resistance (retention rate >90%), and maintains good functions in the temperature range of -40°C to 80°C and the humidity range of 30% to 90% RH. In terms of environmental performance, it has a low VOC content (42.6 g / L), does not contain harmful heavy metals, and the free formaldehyde content is far lower than the national standard, meeting the requirements of green building materials and being suitable for safe use in various building environments.

[0073] The above describes the embodiments of the present invention. However, these embodiments are not limited to the above specific implementation manners. The above specific implementation manners are merely illustrative and not restrictive. Under the inspiration of this embodiment, those of ordinary skill in the art can also make more equivalent embodiments in various forms, all of which fall within the protection scope of this embodiment.

Claims

1. A high temperature resistant fire retardant coating and a preparation method thereof, characterized in that: It includes the following components: a basic fireproof layer, a temperature color change warning component, a temperature memory delay display component, an ultraviolet accumulation monitoring component and a signal differentiation display component; the temperature memory delay display component contains a composite of phase change microcapsules and photosensitive memory materials, which can keep the paint in a color change state for 24-72 hours after the temperature drops; the ultraviolet accumulation monitoring component contains ultraviolet sensitive materials encapsulated by selectively transparent materials; the signal differentiation display component makes the temperature memory display and ultraviolet accumulation display appear in different colors.

2. The high temperature resistant fire retardant coating according to claim 1, characterized in that: The basic fireproof layer is composed of inorganic silicate, phosphate refractory material and inorganic adhesive, wherein the weight ratio of inorganic silicate to phosphate refractory material is 60-75:25-40, and the addition amount of inorganic adhesive is 5-10% of the total weight.

3. The high temperature resistant fire retardant coating according to claim 1, characterized in that: The temperature color change warning component contains a thermochromic material, which undergoes a visible color change at 150±5°C. The thermochromic material is selected from ferrite or vanadate color change materials and is surface modified by a silane coupling agent.

4. The high temperature resistant fire retardant coating according to claim 1, characterized in that: The phase change microcapsule in the temperature memory delay display component contains a phase change material with a melting point of 150-170°C as a core and a wall material as a coating layer; the phase change material is selected from one or more of octadecane, paraffin or stearic acid; the wall material is a mixture of gelatin or gum arabic and polyvinyl alcohol.

5. The high temperature resistant fire retardant coating according to claim 1, characterized in that: The photosensitive memory material in the temperature memory delay display component is a spiropyran compound, which is loaded by a polymethyl methacrylate carrier.

6. The high temperature resistant fire retardant coating according to claim 1, characterized in that: The ultraviolet sensitive material in the ultraviolet accumulation monitoring component is selected from one or more of benzidine yellow, azo compounds or titanium dioxide / cerium oxide composites; the selective permeable material is a cross-linked product of polymethylsiloxane and tetraethoxysilane.

7. The high temperature resistant fire retardant coating according to claim 1, characterized in that: The signal differentiation display component makes the temperature memory displayed in orange-red and the ultraviolet accumulation displayed in blue.

8. The high temperature resistant fire retardant coating according to claim 1, characterized in that: The mass percentage of each component in the coating is: basic fireproof layer 60-80%, temperature color change warning component 5-15%, temperature memory delay display component 8-15%, ultraviolet accumulation monitoring component 3-8%, and other additives 1-5%.

9. A method for preparing a high temperature resistant fire retardant coating, characterized in that: The following steps are involved: Prepare the basic fireproof component, mix the inorganic silicate and phosphate refractory materials, add the inorganic binder, and stir to form a basic fireproof slurry; preparing a thermochromic material, performing surface modification on the thermochromic material, and mixing the thermochromic material with a portion of a basic fireproof slurry to form a pre-dispersed slurry; Preparing a temperature memory component, including preparing a phase change microcapsule, preparing a photosensitive memory material, and compounding the two to form a temperature memory component slurry; The preparation of the UV monitoring component includes selecting UV-sensitive materials, preparing selectively permeable shell materials, encapsulating to form UV-sensitive microcapsules by interfacial polymerization, and preparing pre-dispersed slurry; Multi-component fusion, the temperature memory component slurry is mixed with the ultraviolet monitoring component slurry to form a functional component mixed slurry, which is then mixed with the basic fireproof slurry and the thermochromic pre-dispersed slurry to obtain the final multifunctional high temperature resistant fireproof coating.

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