Low-temperature porcelain-forming nano-micro-eruptive high-temperature radiation coating, preparation method and application thereof

Abstract

This application relates to a low-temperature ceramic-forming nano-micro-melting high-temperature radiation coating, its preparation method, and its application. It comprises a high-temperature radiation agent and a low-temperature ceramic-forming film-forming material in a weight ratio of (8-15):100. The low-temperature ceramic-forming film-forming material consists of the following raw materials in parts by weight: 55-75 parts of ceramic-forming polysilazane agent; 3-8 parts of synergist; 4-8 parts of nano-micro-melting agent; 1-3 parts of additives; and 25-35 parts of solvent. The synergist is at least two of the following: 1,1,5,5-tetramethyl-3,3-diphenyltrisiloxane, methacryloyloxypropyl cage-like polysilsesquioxane, and epoxycyclohexylethyl-glycidyloxypropyl cage-like polysilsesquioxane, with at least one being 1,1,5,5-tetramethyl-3,3-diphenyltrisiloxane. This application, while possessing excellent radiation performance, also exhibits superior resistance to weathering properties such as high temperature, acids and alkalis, and thermal expansion and contraction, reducing the possibility of peeling and wear.

Description

Technical Field

[0001] This application relates to the field of high-performance coating technology, and more specifically, to a low-temperature ceramic nano-melting high-temperature radiation coating, its preparation method, and its application. Background Technology

[0002] High-temperature radiation coatings are functional coatings that can operate for extended periods in high-temperature environments and are widely used in high-temperature industrial fields such as metallurgy, power, aerospace, and building materials. They absorb ambient heat and convert it into infrared radiation energy, achieving heat transfer, energy saving, and temperature control. This is significant for improving the thermal efficiency of high-temperature equipment, extending equipment lifespan, and reducing energy loss. Furthermore, they can assist in achieving high-temperature resistance and oxidation protection for equipment surfaces.

[0003] To meet the high-temperature resistance requirements of coatings in high-temperature service environments, existing technologies generally employ high-temperature resins such as polysilazane as film-forming agents, combined with high-temperature auxiliary agents such as silicon carbide, boron carbide, and rare earth metal oxides. Through the binding effect of the film-forming agent and the high-temperature enhancement effect of the high-temperature auxiliary agents, the coating acquires a certain degree of high-temperature resistance to meet the basic usage requirements of medium- and high-temperature environments. Generally, this method utilizes the properties of high-temperature resins to bond various auxiliary agents together, forming a coating structure with a certain degree of high-temperature resistance. Such coatings can withstand high-temperature environments to a certain extent, providing protection and heat transfer functions for equipment.

[0004] Existing high-temperature radiation coatings prepared using high-temperature resin film-forming agents such as polysilazane have many defects, especially poor service stability under long-term high temperature and radiation conditions. For example, the coating exhibits extremely poor adhesion stability on various substrate surfaces, with weak surface bonding to different types of substrates such as carbon steel, stainless steel, and refractory materials, easily leading to peeling, blistering, and detachment. Furthermore, the thermal expansion and contraction characteristics of the coating are difficult to match with different substrates, resulting in insufficient resistance to temperature-induced cracking. During temperature cycling, problems such as component separation and structural loosening easily occur, leading to large fluctuations in emissivity and reduced service life. Summary of the Invention

[0005] The purpose of this application is to further improve the resistance to high temperature, thermal expansion and contraction, acid and alkali and other weathering properties while ensuring good radiation performance, wear resistance and adhesion, and reduce the possibility of coating peeling and wear during long-term use. It provides a low-temperature ceramic nano-melting high-temperature radiation coating and its application and preparation method.

[0006] In a first aspect, a low-temperature ceramic nano-micro-melting high-temperature radiation coating is provided, comprising a high-temperature radiation agent and a low-temperature ceramic film-forming material in a weight ratio of (8-15):100, wherein the low-temperature ceramic film-forming material is composed of the following raw materials in parts by weight: 55-75 parts of ceramic-forming polysilazane agent; Synergist 3-8 parts; 4-8 parts of nano-micro flux; 1-3 parts of auxiliary agent; Solvent 25-35 parts; The synergist is composed of at least two of the following: 1,1,5,5-tetramethyl-3,3-diphenyltrisiloxane, methacryloyloxypropyl cage-like polysilsesquioxane, and epoxycyclohexylethyl-glycidyloxypropyl cage-like polysilsesquioxane, with at least one being 1,1,5,5-tetramethyl-3,3-diphenyltrisiloxane.

[0007] Using ceramic-forming polysilazane agent as the core film-forming agent, it has the characteristics of excellent low-temperature ceramic-forming properties, strong high-temperature stability, and good adhesion. It can complete film formation and curing in a low-temperature environment. The ceramic film layer formed after curing has a dense structure and excellent toughness. The specific combination design of the synergist forms a synergistic effect with the ceramic-forming polysilazane agent, and can improve the dispersion uniformity of each raw material, enhance the bonding force between each component, and improve the flexibility and aging resistance of the cured coating. Methacryloxypropyl cage-like polysilsesquioxane and epoxycyclohexylethyl-glycidyloxypropyl cage-like polysilsesquioxane possess both rigid POSS nanocage structures and crosslinkable active groups. They can work together with the flexible phenyltrisiloxane segments of 1,1,5,5-tetramethyl-3,3-diphenyltrisiloxane to construct an interpenetrating network of rigid POSS nodes and flexible siloxane segments, synergistically enhancing the nano-melting and high-temperature radiation effects. Combined with ceramic-type polysilazane, the resulting low-temperature ceramic nano-melting high-temperature radiation coating, after curing, maintains excellent radiation performance, wear resistance, and adhesion while further improving the coating's tolerance to complex environments such as high temperatures, alternating hot and cold temperatures, and acidic and alkaline media, effectively reducing the risk of coating cracking, peeling, and wear failure during long-term use.

[0008] Preferably, the ceramic-forming polysilazane agent is composed of organoborosilicate, perhydropolysilazane, and ethylene-type polysilazane in a weight ratio of 1:(0.5-1):(1-2.5).

[0009] This application constructs a matrix of "high heat resistance (boron) - high density (hydrogen) - high toughness (ethylene)" through the precise compounding of organoborosilicate, perhydropolysilazane, and vinyl polysilazane: organoborosilicate serves as the heat-resistant and ceramic core, and its high-temperature pyrolysis generates a SiBCN ceramic skeleton, giving the coating excellent thermal stability; perhydropolysilazane, because it does not contain organic side groups, rapidly hydrolyzes and crosslinks at low temperatures to form a high-density SiO2-ceramic layer, providing ultra-high hardness, wear resistance, and strong adhesion to the substrate; vinyl polysilazane, through the regulation of the crosslinking network by active vinyl groups, enhances the coating's toughness and processing adaptability. The synergistic agent combination uses 1,1,5,5-tetramethyl-3,3-diphenyltrisiloxane as the core flexible component, combined with at least one POSS containing an active functional group (methacryloyloxypropyl cage-like polysilsesquioxane or epoxycyclohexylethyl-glycidyloxypropyl cage-like polysilsesquioxane), constructing an organic-inorganic hybrid network in the matrix with rigid POSS nanonodes and flexible phenylsiloxane segments interpenetrating. This structure synergistically exerts multiple effects: the flexible siloxane segments buffer thermal stress and inhibit cracking; the POSS nanonodes enhance mechanical strength and provide crosslinking sites, chemically bonding with vinyl polysilazane to achieve a strong organic-inorganic interface; simultaneously, the low-temperature ceramic-forming properties of boron-modified polysilazane are coupled with the stress-buffering mechanism of phenylsiloxane, ensuring that the coating rapidly cures into ceramic at low temperatures and maintains structural integrity at high temperatures. Ultimately, while retaining excellent radiation performance, high wear resistance, and strong adhesion, the coating significantly improves its resistance to high temperatures, alternating hot and cold temperatures, and acid and alkali media, effectively reducing the risk of cracking, peeling, and wear failure during long-term use.

[0010] Preferably, the ethylene-type polysilazane is a liquid polysilazane containing vinyl groups and silane-hydrogen bonds.

[0011] This application uses a compound of organoborosilicate, perhydropolysilazane, and ethylene-type polysilazane (liquid polysilazane containing vinyl groups and silane-hydrogen bonds) as a ceramic matrix. It features good low-temperature crosslinking and film-forming properties, low ceramicization temperature, and dense structure after curing. It can form a continuous and stable ceramic coating skeleton at a lower temperature, giving the coating good high-temperature stability, resistance to media, and ceramic strength, providing a basic support for the overall performance of the coating.

[0012] Based on this, a synergist composed of at least two of the following (and at least 1,1,5,5-tetramethyl-3,3-diphenyltrisiloxane), methacryloxypropyl cage-like polysilsesquioxane, and epoxycyclohexylethyl-glycidyloxypropyl cage-like polysilsesquioxane is added; wherein methacryloxypropyl cage-like polysilsesquioxane and epoxycyclohexylethyl-glycidyloxypropyl cage-like polysilsesquioxane possess both rigid POSS nanocage structures and crosslinkable active groups, which can work together with the flexible phenyltrisiloxane segments of 1,1,5,5-tetramethyl-3,3-diphenyltrisiloxane to construct an interpenetrating network of rigid POSS nodes and flexible silica segments, synergistically exerting the nano-micro-melting and high-temperature radiation enhancement effects, and forming a tightly crosslinked composite structure with ceramic polysilazane.

[0013] The low-temperature ceramic nano-melting high-temperature radiation coating prepared in this way, after curing, can further improve the coating's tolerance to complex environments such as high temperature, alternating hot and cold temperatures, and acid and alkali media, while maintaining excellent radiation performance, wear resistance, and adhesion. This effectively reduces the risk of coating cracking, peeling, and wear failure during long-term use.

[0014] Preferably, the synergist is composed of 1,1,5,5-tetramethyl-3,3-diphenyltrisiloxane, methacryloyloxypropyl cage-like polysilsesquioxane, and epoxycyclohexylethyl-glycidyloxypropyl cage-like polysilsesquioxane.

[0015] Furthermore, the weight ratio of 1,1,5,5-tetramethyl-3,3-diphenyltrisiloxane, methacryloyloxypropyl cage-like polysilsesquioxane, and epoxycyclohexylethyl-glycidyloxypropyl cage-like polysilsesquioxane is 7:(0.5-1.5):(1.5-2.5).

[0016] When the synergist is a specific ternary combination consisting of 1,1,5,5-tetramethyl-3,3-diphenyltrisiloxane, methacryloyloxypropyl cage-like polysilsesquioxane, and epoxycyclohexylethyl-glycidyloxypropyl cage-like polysilsesquioxane, it forms a deep synergistic effect with the ceramic polysilazane agent, significantly improving the overall performance of the coating. Among them, 1,1,5,5-tetramethyl-3,3-diphenyltrisiloxane, with its excellent compatibility and interfacial activity, not only effectively improves the dispersion uniformity of multi-components such as ceramic polysilazane, high-temperature radiation agent and nano-micro flux, and enhances interfacial bonding, but also endows the cured coating with excellent flexibility and aging resistance. Methacryloxypropyl cage-like polysilsesquioxane, with its unique cage-like nanostructure and acryloyloxy active groups, introduces rigid nodes and provides crosslinking sites in the system, further enhancing the mechanical strength and heat resistance of the coating. Epoxycyclohexylethyl-glycidyloxypropyl cage-like polysilsesquioxane, through the reactive activity of epoxy groups, chemically bonds with polysilazane and flexible segments, optimizing crosslinking density and network integrity. The three elements work together to construct a rigid-flexible interpenetrating nanonetwork and promote the chemical fusion of the organic-inorganic interface. This greatly enhances the coating's resistance to high temperatures, alternating hot and cold temperatures, and acid and alkali media while maintaining excellent radiation performance, wear resistance, and adhesion, effectively suppressing the risk of cracking, peeling, and wear during long-term use.

[0017] Preferably, the high-temperature radiation agent is composed of nano-TiO2-ZrO2 composite powder and rare earth metal oxides.

[0018] More preferably, the weight ratio of nano-titanium dioxide to zirconium dioxide is 1:(2-4). The weight ratio of nano-TiO2-ZrO2 composite powder to rare earth metal oxide is 1:7-9.

[0019] The high-temperature radiant composed of nano-TiO2-ZrO2 composite powder and rare earth metal oxides plays a decisive role in this coating system, synergistically achieving a leap in performance with other components: First, it achieves extreme radiation efficiency by complementing the band structure of the two components and using lattice defect engineering to achieve ultra-high emissivity across the entire wavelength range (especially in the mid- and far-infrared), maximizing the heat dissipation efficiency of the coating; second, it provides ultra-high temperature stability by effectively suppressing phase transitions and stabilizing the lattice, ensuring that the radiation performance does not decay and the structure does not collapse under long-term high-temperature conditions; third, it facilitates low-temperature dense ceramic formation by using nano-effects and rare earth fluxing to promote the formation of a dense, smooth, and defect-free radiation ceramic layer at low temperatures; and fourth, it ensures long-term reliable service by forming a chemical bond with the coating substrate and combining excellent oxidation resistance to completely solve the risks of radiant shedding, powdering, and failure.

[0020] The aforementioned comprehensive synergistic system can significantly improve the adhesion stability of low-temperature ceramic nano-micro-melting high-temperature radiation coatings, resulting in strong adhesion to various substrate surfaces. It can adhere tightly even after long-term service at both room temperature and high temperature. At the same time, it significantly enhances the coating's adaptability, matching the thermal expansion and contraction characteristics of different substrates and exhibiting excellent resistance to temperature-induced cracking. Ultimately, after the coating is cured, it significantly improves its tolerance to complex environments while maintaining excellent radiation, wear resistance, and adhesion, reducing the risk of coating failure and extending its service life.

[0021] Preferably, the nano-melting aid is nano-silica.

[0022] Nano-silica is used as a "micro-melting aid" to promote low-temperature ceramic formation. Furthermore, through functions such as filling and reinforcement, interface bonding, and rheological regulation, it forms a deep synergy with polysilazane, active POSS, phenyltrisiloxane, and high-temperature radiation agents, ensuring that the coating ultimately achieves advantages such as extreme radiation, strong adhesion, and heat and corrosion resistance.

[0023] The additive is a combination of multiple substances selected from hydrosilylation catalysts, dispersants, anti-settling agents, inhibitors, and antioxidants; the solvent is a combination of multiple substances selected from PGMEA, ethyl acetate, and xylene.

[0024] The selection of the above additives and solvents, combined with the synergist and ceramic-forming polysilazane agent of this application, enables the final coating layer to have better overall performance.

[0025] The rare earth metal oxide is a combination of multiple elements selected from cerium oxide, lanthanum oxide, yttrium oxide, neodymium oxide, praseodymium oxide, samarium oxide, europium oxide, gadolinium oxide, terbium oxide, dysprosium oxide, holmium oxide, erbium oxide, thulium oxide, ytterbium oxide, and lutetium oxide.

[0026] The selection of various rare metal oxides, combined with nano-TiO2-ZrO2 composite powder as a thermal radiation functional filler, ensures high emissivity across various temperature ranges, guaranteeing a high thermal emissivity of ≥0.90 for the coating within the applicable temperature range of 300-1800℃. Meanwhile, the dense film formed at low temperatures ensures its adhesion stability and reduces the consumption of radioactive materials, thereby extending the coating's service life.

[0027] Preferably, the particle size of the nano-silica and the nano-TiO2-ZrO2 composite powder is <200nm.

[0028] The particle size of nano-silica and nano-TiO2-ZrO2 composite powder is made smaller than 200nm, which can further optimize the performance of coatings. Combined with ceramic polysilazane agents, synergists and other components, the coating structure is made denser, which is conducive to improving the radiation performance, weather resistance, wear resistance and adhesion stability of the coating, ensuring long-term stable service of the coating under high temperature and complex working conditions, and improving the thermal utilization efficiency of high temperature equipment.

[0029] Preferably, the hydrosilylation catalyst is a diethylenetetramethyldisiloxane platinum complex.

[0030] This coating is composed of a high-temperature radiant agent and a low-temperature ceramic film-forming material in a specific weight ratio. The low-temperature ceramic film-forming material includes a ceramic polysilazane agent, a synergist, a nano-micro-melting agent, additives, and a solvent. The synergist is a combination of specific components. The high-temperature radiant agent consists of nano-TiO2-ZrO2 composite powder and rare earth metal oxides. The nano-micro-melting agent is nano-silica. The additives contain various components such as a hydrosilylation catalyst. The solvent contains various components such as PGMEA. The use of diethylenetetramethyldisiloxane platinum complex as a hydrosilylation catalyst allows these components to participate in the reaction more effectively, contributing to the formation of a uniformly dispersed and stable coating system. This significantly improves the adhesion stability of the final coating, enabling it to adhere tightly to various substrates. It also enhances compatibility, matching the thermal expansion and contraction characteristics of the substrates and exhibiting excellent resistance to temperature-induced cracking.

[0031] Secondly, the application of a low-temperature ceramic nano-melting high-temperature radiation coating involves using a low-temperature ceramic nano-melting high-temperature radiation coating to produce a coating structure. The first curing temperature is 60-85℃, and the time is 0.5-3h; the second curing temperature is 200℃-280℃, and the curing time is 1-10min.

[0032] Coatings made from high-temperature radiants and low-temperature ceramic-forming film-forming materials with specific compositions can achieve excellent low-temperature ceramic-forming properties, strong high-temperature stability, and good adhesion. Specific combinations of synergists work synergistically with each component to enhance the overall performance of the coating, including significantly improved adhesion stability, enhanced compatibility, improved wear resistance and weather resistance, and guaranteed stable and reliable radiation performance. Specific compositions of ceramic-forming polysilazane agents and the selection of ethylene-type polysilazane further enhance the stability, wear resistance, high-temperature resistance, and adhesion stability of the film layer in complex environments. The selection of specific high-temperature radiants, nano-micro-melting aids, additives, solvents, and particle size requirements optimizes the coating performance. The use of diethylenetetramethyldisiloxane platinum complex as a hydrosilylation catalyst and a specific two-stage curing process for coating structure production allows the coating to better form the desired coating, fully leveraging its various performance advantages, improving the thermal efficiency of high-temperature equipment, and expanding its application range in high-end industrial scenarios.

[0033] Thirdly, a method for preparing a low-temperature ceramic nano-micro molten high-temperature radiation coating is obtained by the following method: 1) By weight, the synergist is dissolved in part of the solvent to obtain a synergistic dispersant; the adjuvant is dissolved in the remaining solvent to obtain a dispersion. 2) According to the weight parts, add the high-temperature radiation agent, the synergistic dispersant, and the nano-micro melt agent to the dispersion in sequence, stir evenly, and obtain the mixed slurry; 3) Grind the mixed slurry according to the weight parts to obtain a stable dispersion slurry; then add the ceramic polysilazane agent, mix evenly, filter, and degas under vacuum to obtain a low-temperature ceramic nano-micro molten high-temperature radiation coating.

[0034] First, the synergist is dissolved in a portion of the solvent to obtain a synergistic dispersant, and the additives are dissolved in the remaining solvent to obtain a dispersion. Then, a high-temperature radiation agent, a synergistic dispersant, and a nano-micro flux are added sequentially to the dispersion and stirred to form a mixed slurry. Next, a stable dispersion slurry is obtained by grinding, followed by the addition of a ceramic-forming polysilazane agent. After mixing, filtration, and vacuum degassing, the coating is obtained. This preparation method ensures thorough dispersion and mixing of all components, guaranteeing uniform distribution of each component in the coating. It helps to leverage the excellent low-temperature ceramic-forming properties, strong high-temperature stability, and good adhesion of the ceramic-forming polysilazane agent, as well as the synergistic effect of the synergist and other components. This results in a significant improvement in the coating's adhesion stability, compatibility, abrasion resistance, weather resistance, and stable and reliable radiation performance.

[0035] In summary, this application includes at least one of the following beneficial technical effects: 1. The synergist combination used in this application uses 1,1,5,5-tetramethyl-3,3-diphenyltrisiloxane as the core flexible component, combined with at least one POSS containing an active functional group (methacryloyloxypropyl cage-like polysilsesquioxane or epoxycyclohexylethyl-glycidyloxypropyl cage-like polysilsesquioxane), to construct an organic-inorganic hybrid network in the matrix in which rigid POSS nanonodes and flexible phenylsiloxane segments interpenetrate, and then combined to form a ceramic-like structure. Polysilazane enables the obtained low-temperature ceramic nano-micro-melting high-temperature radiation coating to achieve an adhesion (cross-cut test) grade of 0. After curing and forming the coating, its hemispherical emissivity at high temperature is ≥0.93 and at room temperature is ≥0.90. After 72 hours of acid and alkali resistance, the coating shows no abnormalities such as blistering, peeling, or discoloration. After 40 cycles of heating at 600℃ and quenching in cold water, there is no peeling. After 120 hours of accelerated aging under QUVB ultraviolet light, the emissivity retention rate is ≥88%, with no chalking or cracking. 2. When the ceramic-forming polysilazane agent is composed of organic polyboron silazane, perhydropolysilazane, and ethylene-type polysilazane, it constructs a matrix with "high heat resistance (boron) - high density (hydrogen) - high toughness (ethylene)," which further improves the overall performance, especially the mass loss retention rate (%) and emissivity retention rate (%). 3. When the synergist is a specific ternary combination composed of 1,1,5,5-tetramethyl-3,3-diphenyltrisiloxane, methacryloyloxypropyl cage-like polysilsesquioxane, and epoxycyclohexyl ethyl-glycidyl oxypropyl cage-like polysilsesquioxane, it forms a deep synergistic effect with the ceramic polysilazane agent, significantly improving the overall performance of the coating, such as the mass loss retention rate (%) and emissivity retention rate (%) both increasing to over 95%. Detailed Implementation

[0036] The present application will be further described in detail below with reference to the embodiments.

[0037] Source of some raw materials: The structural formula of 1,1,5,5-tetramethyl-3,3-diphenyltrisiloxane: ; Methacryloxypropyl cage-type polysilsesquioxane: Ecotion® POSS102; The molecular structure of epoxycyclohexylethyl-glycidyloxypropyl cage-like polysilsesquioxane is as follows: ; Organic polyborosilazane brand and model: IOTA IOTA-9120; CAS No.: 122174-44-1; Ethylene-type polysilazane is a liquid polysilazane containing vinyl groups and silane-hydrogen bonds. Brand name: IOTA IOTA-9108; Hydrosilylation catalyst (IOTA-8100), diethylenetetramethyldisiloxane platinum complex. Example

[0038] Example 1 A method for preparing a low-temperature ceramic nano-micro molten high-temperature radiation coating, obtained by the following method: 1) By weight, the synergist is dissolved in the solvent (PGMEA) to obtain the synergistic dispersant; the adjuvant is dissolved in the remaining solvent (ethyl acetate and xylene) to obtain the dispersion. 2) According to the weight parts, stir the dispersion at a stirring rate of 100 r / min, and then add the high temperature radiation agent, the synergistic dispersant, and the nano-micro melt agent to the dispersion in sequence. After the addition is completed, continue stirring for 10 min to make it evenly dispersed and obtain the mixed slurry. 3) According to the weight, put the mixed slurry into the grinding device and grind it until the particles reach the nanoscale (≤50nm) to obtain a stable dispersion slurry; then add the ceramic polysilazane agent and stir at a stirring rate of 100r / min for 10min to make it uniformly mixed, then transfer it to the filtration device for filtration (1000 mesh sieve), and then transfer it to the vacuum degassing machine for vacuum degassing at a temperature of 25℃, a time of 30min, and a vacuum degree of -0.08 MPa to obtain a low-temperature ceramic nano-melting high-temperature radiation coating.

[0039] The synergist is composed of 1,1,5,5-tetramethyl-3,3-diphenyltrisiloxane and methacryloyloxypropyl cage-type polysilsesquioxane in a weight ratio of 7:3.

[0040] The ceramic-forming polysilazane agent is composed of organic polyboron silazane, perhydropolysilazane, and ethylene-type polysilazane in a weight ratio of 1:0.5:2.5.

[0041] The high-temperature radiation agent is composed of nano TiO2-ZrO2 composite powder and rare earth metal oxides in a weight ratio of 9:1; wherein, the nano TiO2-ZrO2 composite powder contains 70wt% nano titanium dioxide and 30wt% zirconium dioxide.

[0042] The nano-melting additive is nano-silica; the additive is composed of a hydrosilylation catalyst (diethylenetetramethyldisiloxane platinum complex), an inhibitor (tetravinyltetramethylcyclotetrasiloxane), and an antioxidant (antioxidant 1010) in a weight ratio of 1:0.1:0.9.

[0043] The solvents include PGMEA, ethyl acetate, and xylene in a weight ratio of 2:2:1.

[0044] Rare earth metal oxides are composed of cerium oxide, lanthanum oxide, yttrium oxide, neodymium oxide, and europium oxide in a weight ratio of 1:1:1:1:1.

[0045] For details on the amount of raw materials used, please refer to Table 1.

[0046] Example 2-3 The difference between Examples 2-3 and Example 1 is that the amount of raw materials used is different, as shown in Table 1 below; Table 1. Raw material usage (parts by weight) for Examples 1-3

[0047] Example 4

[0048] The difference between Example 4 and Example 2 is that the synergist is composed of 1,1,5,5-tetramethyl-3,3-diphenyltrisiloxane and epoxycyclohexylethyl-glycidyloxypropyl cage-like polysilsesquioxane in a weight ratio of 7:3.

[0049] Example 5 The difference between Example 5 and Example 2 is that the synergist is composed of 1,1,5,5-tetramethyl-3,3-diphenyltrisiloxane, methacryloyloxypropyl cage-like polysilsesquioxane, and epoxycyclohexylethyl-glycidyloxypropyl cage-like polysilsesquioxane in a weight ratio of 7:1:2.

[0050] Example 6 The difference between Example 6 and Example 5 is that the ceramic-forming polysilazane agent is composed of organic polyborosilazane, perhydropolysilazane, and ethylene-type polysilazane in a weight ratio of 1:1:1.

[0051] Example 7 The difference between Example 7 and Example 5 is that the ceramic-forming polysilazane agent is composed of organic polyborosilazane, perhydropolysilazane, and ethylene-type polysilazane in a weight ratio of 1:0.8:1.2.

[0052] Example 8 The difference between Example 8 and Example 5 is that the ceramic-forming polysilazane agent is an organic polyborosilazane.

[0053] Example 9 The difference between Example 9 and Example 5 is that the ceramic-forming polysilazane agent is composed of organic polyboron silazane and ethylene-type polysilazane in a weight ratio of 1:2.

[0054] Example 10 The difference between Example 10 and Example 5 is that the ceramic-forming polysilazane agent is ethylene-type polysilazane.

[0055] Comparative Example Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that the synergist is 1,1,5,5-tetramethyl-3,3-diphenyltrisiloxane.

[0056] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that the synergist is acryloyloxypropyl cage-type polysilsesquioxane.

[0057] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that the synergist is epoxycyclohexyl ethyl-glycidyl oxypropyl cage polysilsesquioxane.

[0058] Comparative Example 4 The difference between Example 4 and Example 1 is that the synergist is replaced with an equal amount of ceramic polysilazane agent.

[0059] Comparative Example 5 The difference between Comparative Example 5 and Example 1 is that the synergist is γ-methacryloyloxypropyltrimethoxysilane.

[0060] Application examples Application Example 1 An application of a low-temperature ceramic nano-melting high-temperature radiation coating was carried out by spraying the low-temperature ceramic nano-melting high-temperature radiation coating of Example 1 onto the surface of 304 stainless steel. The coating with a thickness of 100 micrometers was formed by first curing at 80°C for 1 hour and second curing at 270°C for 5 minutes. Samples were obtained for subsequent experimental performance testing.

[0061] Application Example 2-14 The difference between Application Example 2-14 and Application Example 1 lies in the different sources of the low-temperature porcelain-forming nano-melt high-temperature radiation coating, which are specifically as follows; Table 2 Sources of the low-temperature porcelain-forming nano-melt high-temperature radiation coating for Application Examples 1-14

[0062] Performance Detection Test 1. Radiation Performance: Refer to GJB 2502.3-2015 "Test Methods for Thermal Control Coatings of Spacecraft - Part 3: Emissivity Test", and measure with a radiometer at a specified temperature; High-temperature section (400 - 1800 °C): Hemispherical emissivity ≥ 0.93.

[0063] Normal temperature (23 °C): Hemispherical emissivity ≥ 0.90.

[0064] When the above requirements are met simultaneously, it is recorded as qualified.

[0065] 2. Adhesion Stability: Refer to GB / T 9286-2021, use a cross cutter to score the coating surface, and observe the grid peeling situation after sticking and tearing with a special tape. If the cutting edge is completely smooth and there is no peeling, it is grade 0.

[0066] When the adhesion (cross cut method) is grade 0, it is recorded as qualified.

[0067] 3. Abrasion Resistance: Detection standard: Refer to GB / T 1768-2006; use a rubber grinding wheel, with a load of 1 kg and a rotation speed of 500 revolutions. Weigh the mass difference before and after the test.

[0068] When the mass loss ≤ 0.2 g, it is recorded as qualified.

[0069] 4. Weather Resistance A. QUV Aging Detection Standard: Refer to GB / T 23987-2009 (QUV aging); use a UVB lamp tube, with a test cycle of 120 h. After the test, first observe the appearance, and there is no powdering or cracking; refer to the detection methods in Experiment 1 and Experiment 2 to detect the normal temperature hemispherical emissivity and mass loss, and calculate the corresponding retention rate.

[0070] B. Thermal Expansion and Contraction Resistance: Refer to GB / T 1735-2009. Heat the specimen to 600 °C, hold for 15 minutes and then quickly take it out, and completely immerse it in cold water at 5 °C (quenching) until the temperature drops to 25 °C. This is 1 cycle. Repeat 40 times and then visually inspect.

[0071] If there is no detachment after 40 cycles of (heating at 600℃ and quenching in cold water), it is considered qualified. Refer to the testing methods in Experiment 1 and Experiment 2 to conduct the test and calculate the mass loss retention rate and hemispherical emissivity before and after the test.

[0072] 1. Acid and alkali resistance: Refer to GB / T 9274-1988 (immersion method); Acid resistance: After immersion in 10% H2SO4 solution for 72 hours, the coating showed no abnormalities such as blistering, peeling, or discoloration. Alkali resistance: After immersion in 10% NaOH solution for 72 hours, the coating showed no abnormalities such as blistering, peeling, or discoloration. Refer to the testing methods in Experiments 1 and 2, conduct tests, and calculate the mass loss retention rate and hemispherical emissivity before and after the test. Take the average value after acid and alkali aging.

[0073] Note: The retention rate is calculated by dividing the experimental data after aging by the experimental data before aging, and then multiplying by 100%.

[0074] The retention rate levels are as follows: I ≥ 95%; 92% ≤ II < 95%; 88% ≤ III < 92%; IV < 88%.

[0075] The specific experimental data are shown in Table 2 below; Table 3 Experimental data from Application Examples 1-15

[0076] Combining Application Example 1 (corresponding to Example 1) and Application Examples 11-15 (corresponding to Examples 1-5) with Table 3, it can be seen that the radiation performance and abrasion resistance of Application Examples 11-15 (corresponding to Examples 1-5) are both unqualified, and the adhesion grade is above level 1, while the adhesion grade of Application Example 1 (corresponding to Example 1) is level 0. However, after the aging performance test, the hemispherical emissivity retention rate and mass loss retention rate of Application Examples 11-15 (corresponding to Examples 1-5) are significantly higher in A (QUV aging performance), B (thermal expansion and contraction resistance), and C (acid and alkali resistance). Most samples were at level IV (Ⅳ<88%), a small portion at level III (88%≦Ⅲ<92%), while the examples all reached level II (92%≦Ⅱ<95%) or higher at level I (Ⅰ≧95%). This indicates that the present application uses at least two of the following synergists: 1,1,5,5-tetramethyl-3,3-diphenyltrisiloxane, methacryloyloxypropyl cage-like polysilsesquioxane, and epoxycyclohexylethyl-glycidyloxypropyl cage-like polysilsesquioxane, with at least one being 1,1,5,5-tetramethyl-3,3-diphenyltrisiloxane. This combination has a better synergistic effect and further improves the overall performance.

[0077] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A low-temperature ceramic nano-micro-melting high-temperature radiation coating, characterized in that, It is composed of a high-temperature radiation agent and a low-temperature ceramic film-forming material in a weight ratio of (8-15):

100. The low-temperature ceramic film-forming material is composed of the following raw materials in parts by weight: 55-75 parts of ceramic-forming polysilazane agent; Synergist 3-8 parts; 4-8 parts of nano-micro flux; 1-3 parts of auxiliary agent; Solvent 25-35 parts; The synergist is composed of at least two of the following: 1,1,5,5-tetramethyl-3,3-diphenyltrisiloxane, methacryloyloxypropyl cage-like polysilsesquioxane, and epoxycyclohexylethyl-glycidyloxypropyl cage-like polysilsesquioxane, with at least one being 1,1,5,5-tetramethyl-3,3-diphenyltrisiloxane.

2. The low-temperature ceramic nano-micro-melting high-temperature radiation coating according to claim 1, characterized in that: The ceramic-forming polysilazane agent is composed of organic polyboron silazane, perhydropolysilazane, and ethylene-type polysilazane in a weight ratio of 1:(0.5-1):(1-2.5).

3. The low-temperature ceramic nano-micro-melting high-temperature radiation coating according to claim 2, characterized in that: The ethylene-type polysilazane is a liquid polysilazane containing vinyl groups and silane-hydrogen bonds.

4. The low-temperature ceramic nano-micro-melting high-temperature radiation coating according to claim 1, characterized in that: The synergist is composed of 1,1,5,5-tetramethyl-3,3-diphenyltrisiloxane, methacryloyloxypropyl cage-like polysilsesquioxane, and epoxycyclohexylethyl-glycidyloxypropyl cage-like polysilsesquioxane.

5. The low-temperature ceramic nano-micro-melting high-temperature radiation coating according to claim 1, characterized in that: The high-temperature radiation agent is composed of nano-TiO2-ZrO2 composite powder and rare earth metal oxides.

6. The low-temperature ceramic nano-micro-melting high-temperature radiation coating according to claim 5, characterized in that: The nano-melting aid is nano-silica; the aid is a combination of multiple substances selected from hydrosilylation catalyst, dispersant, anti-settling agent, inhibitor, and antioxidant; the solvent is a combination of multiple substances selected from PGMEA, ethyl acetate, and xylene. The rare earth metal oxide is a combination of multiple elements selected from cerium oxide, lanthanum oxide, yttrium oxide, neodymium oxide, praseodymium oxide, samarium oxide, europium oxide, gadolinium oxide, terbium oxide, dysprosium oxide, holmium oxide, erbium oxide, thulium oxide, ytterbium oxide, and lutetium oxide.

7. The low-temperature ceramic nano-micro-melting high-temperature radiation coating according to claim 6, characterized in that: The particle size of both the nano-silica and the nano-TiO2-ZrO2 composite powder is <200nm.

8. The low-temperature ceramic nano-micro-melting high-temperature radiation coating according to claim 6, characterized in that: The hydrosilylation catalyst is a diethylenetetramethyldisiloxane platinum complex.

9. An application of a low-temperature ceramic nano-micro-melting high-temperature radiation coating, characterized in that: The low-temperature ceramic nano-micro molten high-temperature radiation coating described in claims 1-8 is used to produce coating structures, with a first curing temperature of 60-85℃ and a time of 0.5-3h. The second curing temperature is 200℃-280℃, and the curing time is 1-10 minutes.

10. A method for preparing a low-temperature ceramic nano-micro-melting high-temperature radiation coating as described in any one of claims 1-8, characterized in that, Obtained by the following method: 1) By weight, the synergist is dissolved in part of the solvent to obtain a synergistic dispersant; the adjuvant is dissolved in the remaining solvent to obtain a dispersion. 2) According to the weight parts, add the high-temperature radiation agent, the synergistic dispersant, and the nano-micro melt agent to the dispersion in sequence, stir evenly, and obtain the mixed slurry; 3) Grind the mixed slurry according to the weight parts to obtain a stable dispersion slurry; then add the ceramic polysilazane agent, mix evenly, filter, and degas under vacuum to obtain a low-temperature ceramic nano-micro molten high-temperature radiation coating.

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