A synergistic protective self-adaptive temperature control fireproof coating and a preparation method thereof

Abstract

The application specifically relates to a synergistically protective self-adaptive temperature control fireproof paint and a preparation method thereof. The fireproof paint takes a phosphate-based composite phase change material as a core material, a urea-formaldehyde resin as a wall material, and further comprises inorganic ceramic fillers, intumescent flame retardants and high-temperature stable additives to form phase change microcapsules. Moreover, the preparation process of the fireproof paint is simple, efficient, controllable and environment-friendly. The fireproof paint has excellent self-adaptive temperature control capability, fireproof performance and mechanical performance, and the fireproof time exceeds 120 min at 1000 DEG C. In the initial stage of fire, the phase change microcapsules absorb heat to delay temperature rise; at high temperature, the phosphorus-containing material promotes carbonization, the intumescent flame retardant forms a carbon layer, and the inorganic ceramic fillers are sintered into a heat insulation layer, realizing the synergistic protection of "initial heat absorption and temperature reduction and high-temperature flame retardation and heat insulation", and providing an efficient, environment-friendly and stable fireproof solution for the fields of buildings, transportation and electronic equipment.

Description

Technical Field

[0001] This invention relates to the field of fire-retardant coating technology, specifically to a synergistic protective adaptive temperature-controlled fire-retardant coating and its preparation method. Background Technology

[0002] With the rapid development of fields such as construction, transportation, and electronic equipment, the demand for fire-retardant coatings is increasing, placing higher requirements on the performance of fire-retardant materials. Traditional fire-retardant coatings mainly rely on materials such as expanded graphite and aluminum hydroxide, achieving fire-retardant functions through physical expansion or chemical decomposition to absorb heat. However, these materials have significant limitations: firstly, their thermal response is slow, making it difficult to quickly absorb large amounts of heat in the early stages of a fire, leading to a rapid temperature rise; secondly, their flame-retardant efficiency is limited, making it difficult to form a stable heat-insulating char layer at high temperatures; furthermore, traditional coatings have poor environmental friendliness, and the use of some halogenated flame retardants has been restricted by the EU REACH regulation. The high proportion of fire spread accidents caused by the failure of fire-retardant materials in building fires exposes the inadequacies of traditional coatings in thermal management and multiple protection mechanisms.

[0003] In recent years, phase change materials (PCMs) have attracted widespread attention in the field of fire protection due to their excellent thermal energy storage characteristics. PCMs can absorb or release a large amount of latent heat during the phase change process, thereby effectively regulating temperature. However, directly applying PCMs to fire-retardant coatings presents technical challenges: firstly, the poor compatibility between PCMs and the coating matrix can easily lead to a decline in the mechanical properties of the coating; secondly, the insufficient flame-retardant properties of PCMs make it difficult to meet the fire protection requirements at high temperatures. Furthermore, although inorganic ceramic fillers have good heat absorption properties, their dehydration temperature is low, making it difficult to cover the protection requirements throughout the entire fire process when used alone.

[0004] Existing fire-retardant coatings suffer from slow thermal response and poor high-temperature stability. In the early stages of a fire, traditional fire-retardant coatings cannot react quickly, leading to a rapid temperature rise and an inability to effectively suppress the spread of fire. Furthermore, the performance of fire-retardant coatings deteriorates drastically at high temperatures, making it difficult to provide long-term effective protection for the protected object. While CN118599493A describes the preparation of phase-change flame-retardant and thermally conductive microcapsules, it does not address the overall formulation of the fire-retardant coating, failing to achieve multi-component synergistic fire protection. The microcapsules in this technology use a magnesium hydroxide shell and a phosphorus-containing organic phase-change material core. The magnesium hydroxide shell has shortcomings in synergistically working with other components of the coating to form a complete fire protection system. For example, the magnesium hydroxide shell has limited stability at high temperatures and limited adhesion to other materials, making it difficult to maintain its effectiveness during a fire and unsuitable for widespread application. CN104861935A focuses on optimizing the microcapsule preparation process, using a paraffin core and urea-formaldehyde resin wall material. However, this system cannot meet the requirements for high-efficiency fire protection in fire-retardant coatings. Paraffin core materials have a narrow phase change temperature range and poor flame retardant properties. They cannot effectively absorb heat and prevent the spread of fire in a fire, making them unsuitable for widespread application. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of the prior art by providing a synergistic protective adaptive temperature-controlled fireproof coating and its preparation method. Through the combined action of modified epoxy resin, phase change microcapsules, inorganic ceramic fillers, intumescent flame retardants, and nano-reinforced fillers, it achieves rapid thermal response in the early stages of a fire and efficient flame retardancy and heat insulation at high temperatures. This provides a novel fire protection solution for building structures, transportation, and electronic equipment, and is particularly suitable for scenarios with high fire protection requirements, such as buildings, transportation, and electronic equipment.

[0006] The objective of this invention is achieved through the following technical solution: This invention provides a synergistic protective adaptive temperature-controlled fireproof coating, comprising the following raw materials by weight percentage: 30-45% modified epoxy resin, 5-20% phase change microcapsules, 5-20% inorganic ceramic filler, 8-20% intumescent flame retardant, 5-10% nano-reinforcing filler, 3-8% high-temperature stabilizing additive, 1-5% processing aid, and the remainder being deionized water.

[0007] Furthermore, the modified epoxy resin is a cobalt aminosulfonate-modified waterborne epoxy resin. The introduction of cobalt aminosulfonate complexes improves its carbonization ability and thermal stability at high temperatures, while also enhancing the adhesion and flexibility of the coating. In this invention, the preparation method of the modified epoxy resin includes the following steps: (a) adding waterborne epoxy resin and deionized water to a reaction vessel at a mass ratio of 2.5:1 and stirring thoroughly; heating to 45-50°C; slowly adding 2-5 wt% of cobalt aminosulfonate to the waterborne epoxy resin; continuing stirring for 20-30 minutes to completely dissolve it; then adding 1-2 wt% dimethylethanolamine to adjust the pH of the system to 7.5-8.0; (b) continuing to heat to 75-85°C and stirring for 2-3 hours; (c) cooling to below 40°C; adding 2-8 wt% ethylene glycol butyl ether and stirring evenly; then adding deionized water to adjust the solid content to 40-45%; and obtaining the modified epoxy resin through sieving.

[0008] In this invention, by grafting sulfonic acid groups onto the epoxy resin matrix using the above method, the adhesion between the fire-retardant coating and the substrate can be improved. By cobalt ions coordinating with oxygen atoms in the sulfonic acid groups and epoxy chains, a stable cross-linking network is formed, which combines good flexibility and high-temperature strength, and enhances high-temperature stability and high-temperature carbonization ability.

[0009] Furthermore, the inorganic ceramic filler is at least one of nano-alumina, silicate fiber, and nano-titanium dioxide. In this invention, the inorganic ceramic filler forms a stable heat-insulating protective layer at a high temperature of 1000℃. Preferably, the inorganic ceramic filler is composed of silicate fiber, nano-alumina, and nano-titanium dioxide in a mass ratio of 2-7:2-5:1. Through the synergistic effect of these three components, a triple protective barrier of "reflection + shielding + heat insulation" can be formed on the surface of the fireproof coating, delaying heat penetration and improving the fireproof duration and heat insulation capacity of the fireproof coating.

[0010] Furthermore, the intumescent flame retardant is at least one of ammonium polyphosphate, pentaerythritol, and melamine. Preferably, the intumescent flame retardant is a composite of ammonium polyphosphate, pentaerythritol, and melamine in a mass ratio of 2-4:1:1-2.

[0011] In this invention, the intumescent flame retardant utilizes a specific ratio of ammonium polyphosphate, pentaerythritol, and melamine. The reactions of these three components are synchronized and complementary. Ammonium polyphosphate provides an acidic environment and thermal stability, pentaerythritol provides a stable char source, and melamine provides the expansion drive. Furthermore, by precisely controlling the ratio of these three components, dynamic coordination between char layer formation and expansion rate is achieved, thereby generating an intumescent char shell with high adhesion, high density, and thermal stability, effectively blocking oxygen and heat.

[0012] Furthermore, the nano-reinforcing filler is at least one of nano-silica and layered nano-montmorillonite.

[0013] Furthermore, the high-temperature stabilizing agent is at least one selected from magnesium oxide, magnesium silicate, and zinc oxide. This invention improves the thermal shock resistance and anti-peeling properties of the coating under high-temperature conditions by adding the high-temperature stabilizing agent.

[0014] Furthermore, the processing aid includes at least one of a leveling agent, a defoamer, and a thickener. The leveling agent is a polyether-modified polysiloxane leveling agent, used to improve coating uniformity; the defoamer is a polyether-based or mineral oil-based defoamer, used to eliminate bubbles generated during mixing and spraying; the thickener is a polyurethane-based or acrylic-based thickener, used to enhance the storage stability and application performance of the coating. Preferably, the ratio of the leveling agent, defoamer, and thickener is 1.5-4.0:1:1.8-4.0.

[0015] Furthermore, the preparation method of the phase change microcapsules includes the following steps:

[0016] Step A1: Dissolve 10-20 parts of tributyl phosphate in 30-50 parts of anhydrous ethanol, add 3-6 parts of alkyl chain modifier, and then add 0.5-1.0 parts of p-toluenesulfonic acid as an esterification catalyst. Heat and stir the mixture at 50-60℃ for 6-8 hours to form a phosphate ester-based composite phase change material. After the reaction is complete, allow it to cool naturally to room temperature and separate the organic phase. Then, mix the obtained organic phase with emulsifier and water at a mass ratio of 1:2:5. The mixture is then processed by a high-speed shear homogenizer at a shear rate of 8000-12000 rpm for 5-10 minutes to obtain a stable O / W type emulsion.

[0017] Step A2: Add an aqueous solution containing urea and formaldehyde at a molar ratio of 1:1.5-2.0 to the emulsion obtained in step A1, wherein the amount of urea is 3-6% of the total mass of the emulsion and the amount of formaldehyde solution is 5-8%; then adjust the pH of the system to 2.0-2.5, raise the temperature to 50-70℃, and maintain the temperature for 2-4 hours to allow the urea-formaldehyde resin to polymerize on the outer surface of the phase change core to form a uniform wall material layer; by adjusting the stirring speed to 300-600 rpm, the microcapsule particle size is stably controlled within the range of 1-10 μm;

[0018] Step A3: After the reaction is complete, the suspension is naturally cooled to room temperature, and the precipitated microcapsules are collected by centrifugation. The microcapsules are washed 3-5 times with deionized water to remove surface free matter and residual monomers. Finally, the microcapsule powder is freeze-dried at -50°C for 24-36 hours to obtain the phase change microcapsule powder, which is then stored in a dry and sealed environment for later use.

[0019] Furthermore, in step A1, the alkyl chain in the alkyl chain modifier has a carbon number of C6-C18; the emulsifier is Span-80 and / or Tween-80, and the amount of the emulsifier is 2-5% of the total mass of the emulsion. Preferably, the emulsifier is a compound of Span-80 and Tween-80 in a mass ratio of 3:2.

[0020] In this invention, the phase change microcapsules utilize the esterification configuration of tributyl phosphate with alkyl chains of different chain lengths under the action of an acidic catalyst to synthesize a novel composite phase change material with a phosphate ester skeleton. The introduction of long-chain alkyl groups allows for flexible adjustment of the phase change temperature range of this composite phase change material. Compared to traditional organic phase change core materials such as paraffin and fatty alcohols, it exhibits superior thermal stability, phase change rate control, and interfacial activity matching at high temperatures. This phase change agent demonstrates excellent emulsification stability and wall material affinity during microencapsulation, providing a material basis for achieving adaptive temperature control and long-lasting fire-retardant functions in coating systems.

[0021] This invention provides a method for preparing the above-mentioned synergistic protective adaptive temperature-controlled fire-retardant coating, comprising the following preparation steps:

[0022] Step S1: Prepare phase change microcapsules;

[0023] Step S2: Mix the modified epoxy resin with processing aids and deionized water to form a uniform base material;

[0024] Step S3: Add phase change microcapsules, inorganic ceramic fillers, intumescent flame retardants, nano-reinforced fillers and high-temperature stabilizing agents to the base material obtained in step S2 according to the formula ratio, and stir to disperse;

[0025] Step S4: Ultrasonic dispersion is used to further mix the components thoroughly, thus obtaining the synergistic protective adaptive temperature-controlled fireproof coating.

[0026] Furthermore, in step S4, the ultrasonic dispersion time is 30-60 min and the temperature is 25-40℃.

[0027] In this invention, the synergistic protective adaptive temperature-controlled fireproof coating prepared by the above method can achieve dynamic temperature control at high temperatures, with a maximum cooling rate of 15-20℃ / min, and the coating can remain stable at 1000℃, with a fireproof time of more than 120min.

[0028] The beneficial effects of the present invention are as follows: (1) The present invention successfully synthesizes a high-efficiency fireproof coating with adaptive temperature control function through the ingenious combination of phase change microcapsules, inorganic ceramic fillers and intumescent flame retardants. The core mechanism of the fireproof coating is based on the synergistic effect of the heat absorption regulation of phase change microcapsules, the high temperature stability of ceramic fillers and the carbonization expansion effect of the flame retardant system. Under low temperature or normal temperature conditions, phase change microcapsules exist stably and will not affect the basic mechanical properties of the coating. When the fire occurs in the early stage, the phosphate ester-based composite phase change material in the phase change microcapsules can quickly absorb a large amount of heat and undergo phase change, significantly reducing the temperature rise rate of the coating, avoiding the high temperature impact on the substrate in the early stage of the fire, and effectively delaying the spread of the fire. As the temperature further rises to 1000℃, the intumescent flame retardant releases gas and expands to form a dense carbon layer. At the same time, the inorganic ceramic filler forms a stable heat insulation barrier at high temperature. The two continue to play a role at high temperature, effectively preventing heat from being transferred to the substrate, so that the fireproof coating can withstand fire for more than 120 minutes at 1000℃, greatly improving the protection capability of the substrate. In addition, the addition of nano-silica and ceramic powder can improve the density and durability of the coating, enabling it to maintain its integrity even under extreme high-temperature environments.

[0029] (2) The fire-retardant coating of the present invention employs a multi-layer protection mechanism, namely, through dynamic heat absorption, char layer expansion, and ceramic insulation, the performance of the fire-retardant coating is comprehensively improved. This protection mechanism includes the phase change process of the phase change microcapsules, which can rapidly absorb heat in the early stages of a fire, effectively reducing the rate of temperature rise and preventing thermal damage to the substrate in the early stages of a fire. The synergistic effect of the intumescent flame retardant and the ceramic filler ensures that the coating can maintain a fire-retardant time of more than 120 minutes in a high-temperature environment, greatly improving the long-term protection capability for the substrate.

[0030] (3) The preparation method of the fire-retardant coating provided by the present invention is simple, has a short process, and the production conditions are temperature-controllable, resulting in stable product quality. The fire-retardant coating obtained by this preparation method has excellent adaptive temperature control function, thermal stability, and protective performance, and is suitable for high-temperature fire protection in multiple fields such as construction, transportation, and electronic equipment. Attached Figure Description

[0031] Figure 1 Here is a SEM image of the phase change microcapsules from Example 1;

[0032] Figure 2 This is a schematic diagram of the fire-resistant mechanism of the fire-retardant coating (SEM image of the carbonized layer in Example 1). Detailed Implementation

[0033] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments. The content mentioned in the embodiments is not intended to limit the present invention.

[0034] As a classic embodiment of the present invention, the present invention provides a synergistic protective adaptive temperature control fireproof coating, comprising the following raw materials by weight percentage: 30-45% modified epoxy resin, 5-20% phase change microcapsules, 5-20% inorganic ceramic filler, 8-20% intumescent flame retardant, 5-10% nano-reinforcing filler, 3-8% high temperature stabilizing agent, 1-5% processing aid, and the remainder being deionized water.

[0035] Furthermore, the modified epoxy resin is a cobalt aminosulfonate-modified waterborne epoxy resin. The introduction of cobalt aminosulfonate complexes improves its carbonization ability and thermal stability at high temperatures, while also enhancing the adhesion and flexibility of the coating. In this invention, the preparation method of the modified epoxy resin includes the following steps: (a) adding waterborne epoxy resin and deionized water to a reaction vessel at a mass ratio of 2.5:1 and stirring thoroughly; heating to 45-50°C; slowly adding 2-5 wt% of cobalt aminosulfonate to the waterborne epoxy resin; continuing stirring for 20-30 minutes to completely dissolve it; then adding 1-2 wt% dimethylethanolamine to adjust the pH of the system to 7.5-8.0; (b) continuing to heat to 75-85°C and stirring for 2-3 hours; (c) cooling to below 40°C; adding 2-8 wt% ethylene glycol butyl ether and stirring evenly; then adding deionized water to adjust the solid content to 40-45%; and obtaining the modified epoxy resin through sieving.

[0036] Furthermore, the inorganic ceramic filler is at least one of nano-alumina, silicate fiber, and nano-titanium dioxide. Preferably, the inorganic ceramic filler is composed of silicate fiber, nano-alumina, and nano-titanium dioxide in a mass ratio of 2-7:2-5:1. The nano-alumina has a particle size of 20-50 nm, and the silicate fiber has an aspect ratio greater than 10. For this coating, the mechanism by which the inorganic ceramic filler forms a stable thermal insulation layer at 1000℃ can be summarized as follows: In the early stages of a fire, nano-alumina reflects heat radiation with its high reflectivity, delaying heat accumulation; silicate fiber inhibits heat convection through a three-dimensional porous network and consumes heat through a melting phase change. As the temperature rises to 1000℃, the surface of the nano-alumina particles sinters and densifies, forming a low thermal conductivity ceramic layer; the nano-titanium dioxide undergoes anatase-rutile phase transformation, and its nanoparticles migrate to the surface to form a dense oxide layer, further blocking heat conduction. The three elements work together to form a gradient thermal insulation structure of "reflection-porous barrier-dense ceramic". At the same time, the coating stress is relieved by matching the coefficient of thermal expansion and chemically bonded with the expandable flame-retardant carbon layer, ultimately achieving a fire resistance of more than 120 minutes at extreme high temperatures.

[0037] Furthermore, the intumescent flame retardant is at least one of ammonium polyphosphate, pentaerythritol, and melamine. Preferably, the intumescent flame retardant is a composite of ammonium polyphosphate, pentaerythritol, and melamine in a mass ratio of 2-4:1:1-2. Among them, the intumescent flame retardant adopts a unique ratio of ammonium polyphosphate: pentaerythritol: melamine = 2-4:1:1-2. The core mechanism achieves dynamic fire-retardant performance through a three-stage synergistic effect: ① Ammonium polyphosphate acts as an acid source, decomposing at 150-300℃ to generate polyphosphoric acid, which catalyzes the dehydration and cross-linking of pentaerythritol to form a carbon skeleton; ② One part of melamine releases gas (NH3 / H2O) to drive expansion, and its release rate is synchronized with the carbonization rate of pentaerythritol, preventing gas overload from causing the carbon layer to collapse; ③ When the proportion of ammonium polyphosphate is increased to 4:1, excess pyrophosphate (800℃) forms a POC cross-linked structure with the carbon skeleton, which increases the graphitization degree of the carbon layer. At the same time, it synergistically generates a Si-OP ceramic barrier with inorganic ceramic fillers. Finally, through the synergistic effect of expansion effect and heat release inhibition, the dual flame-retardant effect of carbon layer structure strengthening and heat dissipation is achieved.

[0038] Furthermore, the nano-reinforced filler is nano-silica and / or layered nano-montmorillonite. To improve the dispersibility of the nano-reinforced filler, it is pretreated with a silane coupling agent such as KH-550 before use.

[0039] Furthermore, the high-temperature stabilizing agent is at least one of magnesium oxide, magnesium silicate, and zinc oxide.

[0040] Furthermore, the processing aids include at least one of a leveling agent, a defoamer, and a thickener. The leveling agent is a polyether-modified polysiloxane leveling agent, used to improve coating uniformity; the defoamer is a polyether- or mineral oil-based defoamer, used to eliminate bubbles generated during mixing and spraying; the thickener is a polyurethane- or acrylic-based thickener, used to enhance the storage stability and application performance of the coating. Preferably, the ratio of the leveling agent, defoamer, and thickener is 1.5-4.0:1:1.8-4.0. This invention achieves a dynamic balance between rheological properties and defect control through the design of processing aid combinations: a reasonable proportion of leveling agent ensures uniform spreading of the thick system containing microcapsules / fillers; an appropriate amount of defoamer inhibits bubble generation during stirring and dispersion, avoiding excessive addition that leads to a decrease in coating density; and the thickener, through its shear-thinning properties, balances storage stability and application flowability, preventing microcapsule rupture. This ratio, as verified by the process, can simultaneously achieve low surface defects and high component integrity, ensuring the reliability of large-scale preparation of fire-retardant coatings.

[0041] Furthermore, the preparation method of the phase change microcapsules includes the following steps:

[0042] Step A1: Dissolve 10-20 parts of tributyl phosphate in 30-50 parts of anhydrous ethanol, add 3-6 parts of alkyl chain modifier, and then add 0.5-1.0 parts of p-toluenesulfonic acid as an esterification catalyst. Heat and stir the mixture at 50-60℃ for 6-8 hours to form a phosphate ester-based composite phase change material. After the reaction, allow it to cool naturally to room temperature. Separate the aqueous and organic phases using a separatory funnel and remove the water. Then, mix the obtained phase change material solution with emulsifier and water at a mass ratio of 1:2:5. Process the mixture using a high-speed shear homogenizer at a shear rate of 8000-12000 rpm for 5-10 minutes to obtain a stable O / W type emulsion.

[0043] Step A2: Add an aqueous solution containing urea and formaldehyde at a molar ratio of 1:1.5-2.0 to the emulsion obtained in step A1, wherein the amount of urea is 3-6% of the total mass of the emulsion, and the amount of 37% formaldehyde solution is 5-8%; adjust the pH of the system to 2.0-2.5 using hydrochloric acid, raise the temperature to 50-70℃, and maintain this temperature for 2-4 hours to allow the urea-formaldehyde resin to polymerize on the outer surface of the phase change core to form a uniform wall material layer; by adjusting the stirring speed to 300-600 rpm, the microcapsule particle size is stably controlled within the range of 1-10 μm;

[0044] Step A3: After the reaction is complete, the suspension is naturally cooled to room temperature, and the precipitated microcapsules are collected by centrifugation at 6000-8000 rpm for 10-15 min. The microcapsules are washed 3-5 times with deionized water to remove surface free matter and residual monomers. Finally, the microcapsules are freeze-dried at -50℃ for 24-36 h to completely remove moisture, thus obtaining the phase change microcapsule powder. The powder is then stored in a dry and sealed environment for later use.

[0045] Furthermore, in step A1, the alkyl chain in the alkyl chain modifier has a carbon number of C6-C18; the emulsifier is Span-80 and / or Tween-80, and the amount of the emulsifier is 2-5% of the total mass of the emulsion. Preferably, the emulsifier is a compound of Span-80 and Tween-80 in a mass ratio of 3:2.

[0046] This invention provides a method for preparing the above-mentioned synergistic protective adaptive temperature-controlled fire-retardant coating, comprising the following preparation steps:

[0047] Step S1: Prepare phase change microcapsules;

[0048] Step S2: Mix the modified epoxy resin with processing aids and deionized water to form a uniform base material;

[0049] Step S3: Add phase change microcapsules, inorganic ceramic fillers, intumescent flame retardants, nano-reinforced fillers and high-temperature stabilizing agents to the base material obtained in step S2 according to the formula ratio, and stir to disperse;

[0050] Step S4: Ultrasonic dispersion is used to further mix the components thoroughly, thus obtaining the synergistic protective adaptive temperature-controlled fireproof coating.

[0051] Furthermore, in step S4, the ultrasonic dispersion time is 30-60 min and the temperature is 25-40℃.

[0052] Example 1

[0053] This embodiment provides a synergistic protective adaptive temperature control fireproof coating (hereinafter referred to as fireproof coating I), which includes the following raw materials in parts by weight: 38g modified epoxy resin, 8g phase change microcapsules, 10g inorganic ceramic filler, 20g intumescent flame retardant, 7g nano-reinforcing filler, 3g high temperature stabilizing agent, 2.5g processing aid, and 11.5g deionized water containing 5wt% propylene glycol.

[0054] The inorganic ceramic filler is composed of 5g of silicate fiber, 4g of nano-alumina, and 1g of nano-titanium dioxide; the intumescent flame retardant is composed of 10g of ammonium polyphosphate, 6g of pentaerythritol, and 4g of melamine; the nano-reinforcing filler is nano-silica; the high-temperature stabilizing agent is composed of 2g of magnesium oxide and 1g of zinc oxide; the processing aid is composed of 0.8g of leveling agent, 0.5g of defoamer, and 1.2g of thickener, wherein the leveling agent is polyether-modified polysiloxane leveling agent BYK-333, the defoamer is polyether defoamer TEGO FOAMEX 810, and the thickener is polyurethane thickener RM-2020NPR.

[0055] In this embodiment, the preparation method of the modified epoxy resin includes the following steps: (a) adding bisphenol A type waterborne epoxy resin and deionized water into a reaction vessel at a mass ratio of 2.5:1 and stirring thoroughly, heating to 45°C, slowly adding 3wt% of cobalt aminosulfonate of bisphenol A type waterborne epoxy resin, continuing to stir for 30 min to completely dissolve it, and then adding 1.5wt% dimethylethanolamine to adjust the pH of the system to 7.5; (b) continuing to heat to 80°C and stirring for 3 h; (c) cooling to below 40°C, adding 4wt% ethylene glycol butyl ether, stirring evenly, then adding deionized water to adjust the solid content to 40%, and obtaining the modified epoxy resin by sieving.

[0056] In this embodiment, the preparation method of the phase change microcapsules includes the following steps:

[0057] Step A1: Dissolve 18 parts of tributyl phosphate in 40 parts of anhydrous ethanol, add 4 parts of alkyl chain modifier, and then add 0.8 parts of p-toluenesulfonic acid as an esterification catalyst. Heat and stir at 55°C for 8 hours to form a phosphate ester-based composite phase change material. After the reaction, allow it to cool naturally to room temperature, separate the aqueous phase and organic phase using a separatory funnel, and remove the water. Then, mix the obtained phase change material solution with emulsifier and water at a mass ratio of 1:2:5. The mixture is then processed by a high-speed shear homogenizer at a shear rate of 10,000 rpm for 8 minutes to obtain a stable O / W type emulsion.

[0058] Step A2: Add an aqueous solution containing urea and formaldehyde at a molar ratio of 1:1.7 to the emulsion obtained in step A1, wherein the amount of urea is 4% of the total mass of the emulsion and the amount of 37% formaldehyde solution is 6%; adjust the pH of the system to 2.5 using hydrochloric acid, raise the temperature to 60°C, and maintain this temperature for 3 hours to allow the urea-formaldehyde resin to polymerize on the outer surface of the phase change core to form a uniform wall material layer; by adjusting the stirring speed to 500 rpm, the microcapsule particle size is stably controlled within the range of 1-10 μm;

[0059] Step A3: After the reaction is complete, the suspension is naturally cooled to room temperature, and the precipitated microcapsules are collected by centrifugation at 7000 rpm for 12 min. The microcapsules are washed three times with deionized water to remove surface free matter and residual monomers. Finally, the microcapsules are freeze-dried at -50℃ for 24 h to completely remove moisture, thus obtaining the phase change microcapsule powder. The powder is then stored in a dry and sealed environment for later use.

[0060] Furthermore, in step A1, the alkyl chain modifier is octadecyl alcohol; the emulsifier is a compound of Span-80 and Tween-80 in a mass ratio of 3:2, and the amount of the emulsifier is 3% of the total mass of the emulsion.

[0061] This embodiment provides a method for preparing the above-mentioned synergistic protective adaptive temperature-controlled fire-retardant coating, including the following preparation steps:

[0062] Step S1: Prepare phase change microcapsules;

[0063] Step S2: Mix the modified epoxy resin with processing aids and deionized water to form a uniform base material;

[0064] Step S3: Add phase change microcapsules, inorganic ceramic fillers, intumescent flame retardants, nano-reinforced fillers and high-temperature stabilizing agents to the base material obtained in step S2 according to the formula ratio, and stir to disperse;

[0065] Step S4: Ultrasonic dispersion is used to further mix the components thoroughly, thus obtaining the synergistic protective adaptive temperature-controlled fireproof coating.

[0066] Furthermore, in step S4, the ultrasonic dispersion time is 45 minutes and the temperature is 30°C.

[0067] Example 2

[0068] This embodiment provides a synergistic protective adaptive temperature control fireproof coating (hereinafter referred to as fireproof coating II), which includes the following raw materials in parts by weight: 35g modified epoxy resin, 12g phase change microcapsules, 8g inorganic ceramic filler, 16g intumescent flame retardant, 6g nano-reinforcing filler, 4g high temperature stabilizing agent, 3.5g processing aid, and 15.5g deionized water.

[0069] The inorganic ceramic filler is composed of 4g of silicate fiber, 3g of nano-alumina, and 1g of nano-titanium dioxide; the intumescent flame retardant is composed of 8g of ammonium polyphosphate, 5g of pentaerythritol, and 3g of melamine; the nano-reinforcing filler is layered nano-montmorillonite; the high-temperature stabilizing agent is magnesium oxide; the processing aid is composed of 1.2g of leveling agent, 0.8g of defoamer, and 1.5g of thickener, wherein the leveling agent is polyether-modified polysiloxane leveling agent HT-706, the defoamer is mineral oil defoamer BYK-024, and the thickener is acrylic thickener Rheovis AS1130.

[0070] In this embodiment, the preparation method of the modified epoxy resin includes the following steps: (a) adding bisphenol A type aqueous epoxy resin and deionized water into a reaction vessel at a mass ratio of 2.5:1 and stirring thoroughly, heating to 50°C, slowly adding 3wt% of cobalt aminosulfonate of bisphenol A type aqueous epoxy resin, continuing to stir for 25 min to completely dissolve it, and then adding 2wt% dimethylethanolamine to adjust the pH of the system to 8.0; (b) continuing to heat to 80°C and stirring for 2.5 h; (c) cooling to below 40°C, adding 5wt% ethylene glycol butyl ether, stirring evenly, then adding deionized water to adjust the solid content to 40%, and obtaining the modified epoxy resin by sieving.

[0071] In this embodiment, the preparation method of the phase change microcapsules includes the following steps:

[0072] Step A1: Dissolve 13 parts of tributyl phosphate in 32 parts of anhydrous ethanol, add 3 parts of alkyl chain modifier, and then add 0.6 parts of p-toluenesulfonic acid as an esterification catalyst. Heat and stir at 60°C for 7 hours to form a phosphate ester-based composite phase change material. After the reaction, allow it to cool naturally to room temperature, separate the aqueous phase and organic phase using a separatory funnel, and remove the water. Then, mix the obtained phase change material solution with emulsifier and water at a mass ratio of 1:2:5. The mixture is then processed by a high-speed shear homogenizer at a shear rate of 10,000 rpm for 8 minutes to obtain a stable O / W type emulsion.

[0073] Step A2: Add an aqueous solution containing urea and formaldehyde at a molar ratio of 1:1.8 to the emulsion obtained in step A1, wherein the amount of urea is 5% of the total mass of the emulsion and the amount of 37% formaldehyde solution is 6%; adjust the pH of the system to 2.5 using hydrochloric acid, raise the temperature to 65°C, and maintain this temperature for 3 hours to allow the urea-formaldehyde resin to polymerize on the outer surface of the phase change core to form a uniform wall material layer; by adjusting the stirring speed to 500 rpm, the microcapsule particle size is stably controlled within the range of 1-10 μm;

[0074] Step A3: After the reaction is complete, the suspension is naturally cooled to room temperature, and the precipitated microcapsules are collected by centrifugation at 7000 rpm for 12 min. The microcapsules are washed three times with deionized water to remove surface free matter and residual monomers. Finally, the microcapsules are freeze-dried at -50℃ for 24 h to completely remove moisture, thus obtaining the phase change microcapsule powder. The powder is then stored in a dry and sealed environment for later use.

[0075] Furthermore, in step A1, the alkyl chain modifier is hexadecyl alcohol; the emulsifier is a compound of Span-80 and Tween-80 in a mass ratio of 3:2, and the amount of the emulsifier is 4% of the total mass of the emulsion.

[0076] The preparation method of the fire-retardant coating described in this embodiment is basically the same as that in Example 1, except that in step S4, the ultrasonic dispersion time is 40 min and the temperature is 35℃.

[0077] Example 3

[0078] This embodiment provides a synergistic protective adaptive temperature control fireproof coating (hereinafter referred to as fireproof coating III), which includes the following raw materials in parts by weight: 40g modified epoxy resin, 6g phase change microcapsules, 12g inorganic ceramic filler, 24g intumescent flame retardant, 5g nano-reinforcing filler, 3g high temperature stabilizing agent, 1.7g processing aid, and 8.3g deionized water.

[0079] The inorganic ceramic filler is composed of 6g of silicate fiber, 5g of nano alumina, and 1g of nano titanium dioxide; the intumescent flame retardant is composed of 12g of ammonium polyphosphate, 7g of pentaerythritol, and 5g of melamine; the nano-reinforcing filler is nano silica; the high-temperature stabilizing agent is magnesium oxide; and the processing aid is composed of 0.5g of leveling agent, 0.3g of defoamer, and 0.9g of thickener.

[0080] The preparation method of the fire-retardant coating in this embodiment is basically the same as that in Embodiment 1, except that in step S4, the ultrasonic dispersion time is 50 min and the temperature is 30℃. The rest of the contents of this embodiment are the same as those in Embodiment 1, and will not be repeated here.

[0081] Example 4

[0082] This embodiment provides a synergistic protective adaptive temperature control fireproof coating (hereinafter referred to as fireproof coating IV), which includes the following raw materials in parts by weight: 32g modified epoxy resin, 10g phase change microcapsules, 7g inorganic ceramic filler, 18g intumescent flame retardant, 7g nano-reinforcing filler, 4g high temperature stabilizing agent, 3.0g processing aid, and 19g deionized water.

[0083] The inorganic ceramic filler is composed of 3g of silicate fiber, 3g of nano alumina, and 1g of nano titanium dioxide; the intumescent flame retardant is composed of 9g of ammonium polyphosphate, 5g of pentaerythritol, and 4g of melamine; the nano-reinforcing filler is nano silica; the high-temperature stabilizing agent is composed of 2g of magnesium oxide and 2g of zinc oxide; and the processing aid is composed of 1g of leveling agent, 0.6g of defoamer, and 1.4g of thickener.

[0084] The preparation method of the fire-retardant coating in this embodiment is basically the same as that in Embodiment 2, except that in step S4, the ultrasonic dispersion time is 60 minutes and the temperature is 25°C. The rest of the contents of this embodiment are the same as those in Embodiment 2, and will not be repeated here.

[0085] Example 5

[0086] This embodiment provides a synergistic protective adaptive temperature control fireproof coating (hereinafter referred to as fireproof coating V), which includes the following raw materials in parts by weight: 36g modified epoxy resin, 9g phase change microcapsules, 10g inorganic ceramic filler, 20g intumescent flame retardant, 5g nano-reinforcing filler, 3g high temperature stabilizing agent, 2.2g processing aid, and 14.8g deionized water.

[0087] The inorganic ceramic filler is composed of 5g of silicate fiber, 4g of nano alumina and 1g of nano titanium dioxide; the intumescent flame retardant is composed of 11g of ammonium polyphosphate, 6g of pentaerythritol and 3g of melamine; the nano-reinforcing filler is nano silica; the high-temperature stabilizing agent is magnesium silicate; and the processing aid is composed of 0.7g of leveling agent, 0.4g of defoamer and 1.1g of thickener.

[0088] The preparation method of the fire-retardant coating in this embodiment is basically the same as that in Embodiment 1, except that in step S4, the ultrasonic dispersion time is 45 minutes and the temperature is 30°C. The rest of the contents of this embodiment are the same as those in Embodiment 1, and will not be repeated here.

[0089] Example 6

[0090] This embodiment provides a synergistic protective adaptive temperature control fireproof coating (hereinafter referred to as fireproof coating VI), which includes the following raw materials in parts by weight: 34g modified epoxy resin, 11g phase change microcapsules, 8g inorganic ceramic filler, 16g intumescent flame retardant, 8g nano-reinforcing filler, 4g high temperature stabilizing agent, 3.8g processing aid, and 15.2g deionized water.

[0091] The inorganic ceramic filler is composed of 4g of silicate fiber, 3g of nano alumina, and 1g of nano titanium dioxide; the intumescent flame retardant is composed of 7g of ammonium polyphosphate, 4g of pentaerythritol, and 5g of melamine; the nano-reinforcing filler is layered nano montmorillonite; the high-temperature stabilizing agent is composed of 3g of magnesium oxide and 1g of zinc oxide; and the processing aid is composed of 1.5g of leveling agent, 0.5g of defoamer, and 1.8g of thickener.

[0092] The preparation method of the fire-retardant coating in this embodiment is basically the same as that in Embodiment 1, except that in step S4, the ultrasonic dispersion time is 50 min and the temperature is 30℃. The rest of the contents of this embodiment are the same as those in Embodiment 2, and will not be repeated here.

[0093] Example 7

[0094] This embodiment provides a synergistic protective adaptive temperature control fireproof coating (hereinafter referred to as fireproof coating VII), which includes the following raw materials in parts by weight: 37g modified epoxy resin, 7g phase change microcapsules, 13g inorganic ceramic filler, 19g intumescent flame retardant, 7g nano-reinforcing filler, 3g high temperature stabilizing agent, 1.5g processing aid, and 12.5g deionized water.

[0095] The inorganic ceramic filler is composed of 7g of silicate fiber, 5g of nano alumina, and 1g of nano titanium dioxide; the intumescent flame retardant is composed of 13g of ammonium polyphosphate, 5g of pentaerythritol, and 4g of melamine; the nano-reinforcing filler is nano silica; the high-temperature stabilizing agent is magnesium oxide; and the processing aid is composed of 0.6g of leveling agent, 0.2g of defoamer, and 0.7g of thickener.

[0096] The preparation method of the fire-retardant coating in this embodiment is basically the same as that in Embodiment 1, except that in step S4, the ultrasonic dispersion time is 40 minutes and the temperature is 35°C. The rest of the contents of this embodiment are the same as those in Embodiment 1, and will not be repeated here.

[0097] Example 8

[0098] This embodiment provides a synergistic protective adaptive temperature control fireproof coating (hereinafter referred to as fireproof coating VIII), which includes the following raw materials in parts by weight: 33g modified epoxy resin, 13g phase change microcapsules, 6g inorganic ceramic filler, 14g intumescent flame retardant, 5g nano-reinforcing filler, 5g high temperature stabilizing agent, 4.5g processing aid, and 19.5g deionized water.

[0099] The inorganic ceramic filler is composed of 3g of silicate fiber, 2g of nano-alumina, and 1g of nano-titanium dioxide; the intumescent flame retardant is composed of 6g of ammonium polyphosphate, 5g of pentaerythritol, and 3g of melamine; the nano-reinforcing filler is layered nano-montmorillonite; the high-temperature stabilizing agent is composed of 3.5g of magnesium oxide and 1.5g of zinc oxide; and the processing aid is composed of 1.8g of leveling agent, 0.7g of defoamer, and 2g of thickener.

[0100] The preparation method of the fire-retardant coating in this embodiment is basically the same as that in Embodiment 1, except that in step S4, the ultrasonic dispersion time is 50 min and the temperature is 30℃. The rest of the contents of this embodiment are the same as those in Embodiment 2, and will not be repeated here.

[0101] Example 9

[0102] This embodiment provides a synergistic protective adaptive temperature control fireproof coating (hereinafter referred to as fireproof coating IX), which includes the following raw materials in parts by weight: 39g modified epoxy resin, 5g phase change microcapsules, 10g inorganic ceramic filler, 20g intumescent flame retardant, 7g nano-reinforcing filler, 3g high temperature stabilizing agent, 1.7g processing aid, and 14.3g deionized water.

[0103] The inorganic ceramic filler is composed of 5g of silicate fiber, 4g of nano alumina, and 1g of nano titanium dioxide; the intumescent flame retardant is composed of 10g of ammonium polyphosphate, 6g of pentaerythritol, and 4g of melamine; the nano-reinforcing filler is nano silica; the high-temperature stabilizing agent is magnesium oxide; and the processing aid is composed of 0.5g of leveling agent, 0.3g of defoamer, and 0.9g of thickener.

[0104] The preparation method of the fire-retardant coating in this embodiment is basically the same as that in Embodiment 1, except that in step S4, the ultrasonic dispersion time is 50 min and the temperature is 30℃. The rest of the contents of this embodiment are the same as those in Embodiment 1, and will not be repeated here.

[0105] Example 10

[0106] This embodiment provides a synergistic protective adaptive temperature control fireproof coating (hereinafter referred to as fireproof coating X), which includes the following raw materials in parts by weight: 35g modified epoxy resin, 15g phase change microcapsules, 6g inorganic ceramic filler, 11g intumescent flame retardant, 10g nano-reinforcing filler, 3g high temperature stabilizing agent, 4g processing aid, and 16g deionized water.

[0107] The inorganic ceramic filler is composed of 2g of silicate fiber, 3g of nano alumina and 1g of nano titanium dioxide; the intumescent flame retardant is composed of 5g of ammonium polyphosphate, 4g of pentaerythritol and 2g of melamine; the nano-reinforcing filler is nano silica; the high-temperature stabilizing agent is magnesium oxide; and the processing aid is composed of 2.0g of leveling agent, 0.5g of defoamer and 1.5g of thickener.

[0108] The preparation method of the fire-retardant coating in this embodiment is basically the same as that in Embodiment 1, except that in step S4, the ultrasonic dispersion time is 45 minutes and the temperature is 30°C. The rest of the contents of this embodiment are the same as those in Embodiment 2, and will not be repeated here.

[0109] Comparative Example 1

[0110] The difference between this comparative example and Example 1 is that the phase change microcapsules in this comparative example were prepared using the preparation method of patent number CN118599493A. The preparation method of the phase change microcapsules includes the following steps: (a) heating 10.8g of 1-octadecyl alcohol and 4.28g of 3-hydroxyphenylphosphonopropionic acid for 1h to melt them; then adding 0.15g of p-toluenesulfonic acid, and carrying out a stepwise heating reaction under negative pressure, reacting at 120℃ for 1h, 140℃ for 1h, 160℃ for 1h, 180℃ for 1h, and 200℃ for 0.5h respectively to obtain octadecyl 3-hydroxyphenylphosphonopropionic acid; (b) mixing 5g of octadecyl 3-hydroxyphenylphosphonopropionic acid and 0.05g of p-toluenesulfonic acid. Tween 80 and 100 mL of deionized water were added to a four-necked flask, heated at 75 °C and stirred at 150 rpm. After the octadecyl phosphoropropionate was completely melted, the mixture was stirred at 600 rpm for 2 h to obtain a dispersion of 3-hydroxyphenylphosphonopropionate. (c) 1.21 g of sodium hydroxide and 1.44 g of magnesium chloride were dissolved in 10 mL of deionized water. (d) The sodium hydroxide solution and magnesium chloride solution were added dropwise to the 3-hydroxyphenylphosphonopropionate dispersion. During the dropwise addition, the stirring speed was reduced and the mixture was stirred slowly and uniformly. After both solutions were added simultaneously, the reaction was continued for 10 minutes. Then, the mixture was cooled to room temperature under slow stirring. The resulting suspension was filtered, washed several times with deionized water, and dried in an oven at 50 °C for 24 h to obtain 3-hydroxyphenylphosphonopropionate / magnesium hydroxide microcapsules.

[0111] The rest of the content of this embodiment is the same as that of embodiment 1, and will not be repeated here.

[0112] Comparative Example 2

[0113] The difference between this comparative example and Example 1 is that the phase change microcapsules in this comparative example are prepared using the preparation method of patent number CN104861935A. The preparation method of the phase change microcapsules includes the following steps: (a) Add 10 mL of distilled water, 4 g of melamine and 9.5 g of formaldehyde solution with a concentration of 37% to a 250 mL three-necked flask, stir and heat to 70 °C, adjust the pH value of the solution to 10 with triethanolamine, and react at a constant temperature for 30 min to obtain melamine-formaldehyde resin prepolymer. (a) The prepared prepolymer was divided into two equal parts in a 5:5 ratio; (b) 4.5g of styrene-maleic anhydride copolymer was added to 250mL of water as an emulsifier, heated to dissolve, and then 40g of paraffin was added. The mixture was emulsified in a high-shear emulsifier under the following conditions: 5000 rpm for 10 min to obtain a paraffin emulsion; (c) The pH of the emulsion in (b) was adjusted to 4 with citric acid, stirred at 800 rpm, and the emulsion temperature was 70℃. 50% of the prepolymer was added dropwise to the emulsion, and the reaction was allowed to proceed for 1 h; (d) The pH of the mixed emulsion in (c) was adjusted to 5, the stirring speed remained constant, and the emulsion temperature was increased to 75℃. 50% of the prepolymer was added dropwise to the emulsion, and the reaction was allowed to proceed for 2 h. The resulting suspension containing phase change microcapsules was filtered by vacuum filtration and dried in a vacuum drying oven at 50℃ for 2 h to obtain white powdered phase change microcapsules.

[0114] The rest of the content in this embodiment is the same as in embodiment 2, and will not be repeated here.

[0115] Comparative Example 3

[0116] The difference between this comparative example and Example 1 is that the fire-retardant coating provided in this comparative example uses an equal amount of nano-alumina to replace the inorganic ceramic filler in Example 1, uses an equal amount of ammonium polyphosphate to replace the intumescent flame retardant in Example 1, and does not add nano-reinforcing fillers and high-temperature stabilizing additives, while the remaining components are changed in proportion.

[0117] To investigate the performance of the fire-retardant coatings prepared in Examples 1-10 and Comparative Examples 1-3, fire resistance tests were conducted on the samples according to the provisions of standard GB14907-2018 "Fire-retardant Coatings for Steel Structures". The coating expansion thickness, unexposed surface temperature, and fire resistance limit time (target ≥120 min) were recorded. According to GB / T 1765-2009 "Test Method for Damp Heat Resistance of Coating Films", the coating test pieces were placed in a damp heat test chamber (temperature 47℃, relative humidity 96%) and cyclically tested for 240 h to evaluate the coating blistering, cracking, and adhesion loss rate (target ≤5%). The test results of Examples 1-10 are shown in Table 1 below, and the performance comparison with Comparative Examples 1-3 is shown in Table 2 below.

[0118] Table 1 Coating performance test results

[0119]

[0120] Table 2 Comparison and Analysis of Coating Performance

[0121]

[0122] In this invention, the appendix Figure 1 SEM images of the phase change microcapsules prepared in Example 1 are shown. The microcapsules are spherical or nearly spherical in shape, with uniform particle size, relatively smooth surface, and intact structure, indicating that the preparation process of the phase change microcapsules is good. The close packing of particles helps to improve the material's filling rate and thermal conductivity, making it suitable for temperature control and energy storage applications. (Attached) Figure 2 The microstructure of the carbonized fire-retardant coating is shown, revealing a typical porous interconnected network that contributes to thermal insulation and gas barrier properties. The complex skeletal structure of the carbonized layer enhances fire resistance and thermal stability, and strengthens resistance to thermal shock.

[0123] As can be seen from the coating performance test results in Table 1 above, the fire-retardant coating exhibits excellent performance in terms of fire resistance and humid heat stability. Specifically, the fire resistance limit time of the fire-retardant coatings prepared in Examples 1-10 is greater than 120 min, which meets the fire protection requirements; the temperature of the unexposed surface is controlled within the range of 170~190℃, which is good; the maximum cooling rate is 16.8~19.5 ℃ / min, realizing dynamic temperature control; some samples showed slight blistering or cracking under humid heat (240h), but most samples showed no obvious damage; the adhesion loss rate is ≤5%, which meets the standard requirements. In particular, Example 7 exhibited the best performance in terms of fire resistance, thermal stability, and damp heat stability. Specifically, its fire resistance limit time reached 132 min, the longest among all examples; the back-exposed surface temperature was only 170°C, the lowest among all examples, indicating excellent thermal insulation performance of the coating; the highest cooling rate reached 19.5°C / min, demonstrating good dynamic temperature control capability; after 240 hours of damp heat testing, there was no blistering or cracking, indicating excellent stability of the coating in high humidity environments; and the adhesion loss rate was only 2.0%, the lowest among all examples, indicating that the coating maintained good adhesion.

[0124] As can be seen from the comparative analysis of coating performance in Table 2 above, the fire-retardant coatings prepared in Examples 3, 7, and 9 are superior to those in Comparative Examples 1-3 in terms of fire resistance, tensile strength, and flexural strength. Specifically, their fire resistance time exceeds that of Comparative Examples 1-3 by at least 40°C, their peak temperature on the unexposed surface is at least 38°C higher than that of Comparative Examples 1-3, their tensile strength is at least 1.3 MPa higher, and their flexural strength is at least 3.7 MPa higher. This demonstrates that the fire-retardant coating prepared in this invention possesses long-lasting and stable fire-retardant performance and can provide excellent high-temperature fire protection for the substrate.

[0125] The specific embodiments described above are further illustrations of the technical solution and beneficial effects of the present invention, and are not intended to limit the implementation methods. For those skilled in the art, any obvious substitutions without departing from the concept of the present invention are within the protection scope of the present invention.

Claims

1. A synergistic protective adaptive temperature-controlled fire-retardant coating, characterized in that: The raw materials include the following weight percentages: modified epoxy resin 30-45%, phase change microcapsules 5-20%, inorganic ceramic filler 5-20%, intumescent flame retardant 8-20%, nano-reinforcing filler 5-10%, high temperature stabilizing agent 3-8%, processing aid 1-5%, and the remainder is deionized water. The preparation method of the phase change microcapsules includes the following steps: Step A1: Dissolve 10-20 parts of tributyl phosphate in 30-50 parts of anhydrous ethanol, add 3-6 parts of alkyl chain modifier, and then add 0.5-1.0 parts of p-toluenesulfonic acid as an esterification catalyst. Heat and stir the mixture at 50-60℃ for 6-8 hours to form a phosphate ester-based composite phase change material. After the reaction is complete, allow it to cool naturally to room temperature and separate the organic phase. Then, mix the obtained organic phase with emulsifier and water at a mass ratio of 1:2:

5. The mixture is then processed by a high-speed shear homogenizer at a shear rate of 8000-12000 rpm for 5-10 minutes to obtain a stable O / W type emulsion. Step A2: Add an aqueous solution containing urea and formaldehyde at a molar ratio of 1:1.5-2.0 to the emulsion obtained in step A1, wherein the amount of urea is 3-6% of the total mass of the emulsion and the amount of formaldehyde solution is 5-8%; then adjust the pH of the system to 2.0-2.5, raise the temperature to 50-70℃, and maintain the temperature for 2-4 hours to allow the urea-formaldehyde resin to polymerize on the outer surface of the phase change core to form a uniform wall material layer; by adjusting the stirring speed to 300-600 rpm, the microcapsule particle size is stably controlled within the range of 1-10 μm; Step A3: After the reaction is complete, the suspension is naturally cooled to room temperature, and the precipitated microcapsules are collected by centrifugation. The microcapsules are washed 3-5 times with deionized water to remove surface free matter and residual monomers. Finally, the microcapsule powder is freeze-dried at -50°C for 24-36 hours to obtain the phase change microcapsule powder, which is then stored in a dry and sealed environment for later use.

2. The synergistic protective adaptive temperature-controlled fireproof coating according to claim 1, characterized in that: The modified epoxy resin is a waterborne epoxy resin modified with cobalt aminosulfonate.

3. The synergistic protective adaptive temperature-controlled fireproof coating according to claim 1, characterized in that: The inorganic ceramic filler is at least one of nano-alumina, silicate fiber, and nano-titanium dioxide.

4. The synergistic protective adaptive temperature-controlled fireproof coating according to claim 1, characterized in that: The intumescent flame retardant is at least one of ammonium polyphosphate, pentaerythritol, and melamine.

5. The synergistic protective adaptive temperature-controlled fireproof coating according to claim 1, characterized in that: The nano-reinforcing filler is nano-silica and / or layered nano-montmorillonite.

6. The synergistic protective adaptive temperature-controlled fireproof coating according to claim 1, characterized in that: The high-temperature stabilizing agent is at least one of magnesium oxide, magnesium silicate, and zinc oxide.

7. The synergistic protective adaptive temperature-controlled fireproof coating according to claim 1, characterized in that: The processing aids include at least one of leveling agents, defoamers, and thickeners.

8. The synergistic protective adaptive temperature-controlled fireproof coating according to claim 7, characterized in that: The ratio of leveling agent, defoamer, and thickener is 1.5-4.0:1:1.8-4.

0.

9. The preparation method of the synergistic protective adaptive temperature-controlled fire-retardant coating as described in any one of claims 1-8, characterized in that: The preparation steps include the following: Step S1: Prepare phase change microcapsules; Step S2: Mix the modified epoxy resin with processing aids and deionized water to form a uniform base material; Step S3: Add phase change microcapsules, inorganic ceramic fillers, intumescent flame retardants, nano-reinforced fillers and high-temperature stabilizing agents to the base material obtained in step S2 according to the formula ratio, and stir to disperse; Step S4: Ultrasonic dispersion is used to further mix the components thoroughly, thus obtaining the synergistic protective adaptive temperature-controlled fireproof coating.

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