A powder coating with good high-temperature resistance, a high-temperature resistant coating and a preparation method

Abstract

The application provides a powder coating with good high-temperature resistance, a high-temperature resistant coating and a preparation method, and belongs to the field of high-temperature resistant coatings. The powder coating is composed of a bottom coating, an intermediate layer coating and a surface layer coating. The bottom coating is composed of the following chemical components: 20-40 parts of a silicone-epoxy-polyarylether sulfone ternary hybrid resin, 5-15 parts of boron nitride, 2-6 parts of KH-550 modified silicon carbide and 3-8 parts of Al2O3@SiO2 core-shell particles. The intermediate layer coating is composed of the following chemical components: 10-20 parts of a polyimide-siloxane hyperbranched resin, 3-6 parts of Zr-Ti-V composite oxides and 1-4 parts of a nano-kaolinite / talcum powder compound. The surface layer coating is composed of the following chemical components: 10-20 parts of a silicone-epoxy-polyarylether sulfone ternary hybrid resin, 5-15 parts of silica aerogel and 1-3 parts of an ammonium polyphosphate / zinc borate compound. The high-temperature resistant coating has improved high-temperature resistance, corrosion resistance and mechanical properties.

Description

Technical Field

[0001] This application relates to the field of high-temperature resistant coating technology, and in particular to a powder coating with excellent high-temperature resistance, a high-temperature resistant coating, and a preparation method thereof. Background Technology

[0002] High-temperature resistant coatings are a core protective technology for extreme high-temperature environments such as aerospace, energy and power, and chemical equipment. Their core functions include: resisting high-temperature oxidation / corrosion, blocking heat transfer, and maintaining the mechanical properties of the substrate.

[0003] As industrial equipment develops towards higher power density and lighter weight, traditional coating technologies face the following bottlenecks: Ceramic-based coatings (such as Al2O3 and ZrO2), although exhibiting excellent temperature resistance (>1000℃), are brittle (fracture toughness <2MPa·m). 1 / 2 High-temperature resistant coatings exhibit poor thermal shock resistance (cycle count < 5 times) and high thermal conductivity (> 20 W / m·K), failing to prevent heat transfer to the substrate. While silicone resin coatings offer good flexibility and ease of application, they have a low upper temperature limit (typically < 300℃), are prone to decomposition and weight loss (> 10%) at high temperatures, and lack directional thermal management capabilities. The components of composite coatings lack synergy, making it difficult for traditional solutions to achieve synergy between axial heat conduction (dissipation) and radial thermal insulation (protection) within the same coating. High-rigidity resins (such as epoxy resin) are prone to high-temperature brittleness, while flexible resins (such as silicone rubber) struggle to support the filler network, leading to easy peeling of the coating under thermo-mechanical coupling. Therefore, simultaneously improving the high-temperature resistance, corrosion resistance, and mechanical properties of high-temperature coatings is a pressing technical challenge. Summary of the Invention

[0004] This application provides a powder coating with excellent high-temperature resistance, a high-temperature resistant coating, and a preparation method thereof, in order to solve the following technical problem: how to simultaneously improve the high-temperature resistance, corrosion resistance, and mechanical properties of a high-temperature resistant coating.

[0005] In a first aspect, this application provides a powder coating with excellent high-temperature resistance, the powder coating comprising a base coat, an intermediate coat, and a top coat; wherein, by weight,

[0006] The underlying coating is composed of the following chemical components: 20-40 parts of organosilicon-epoxy-polyaryl ether sulfone ternary hybrid resin, 5-15 parts of boron nitride, 2-6 parts of KH-550 modified silicon carbide, and 3-8 parts of Al2O3@SiO2 core-shell particles.

[0007] The intermediate coating is composed of the following chemical components: 10-20 parts of polyimide-siloxane hyperbranched resin, 3-6 parts of Zr-Ti-V composite oxide, and 1-4 parts of nano-kaolinite / talc powder compound.

[0008] The topcoat is composed of the following chemical components: 10-20 parts of organosilicon-epoxy-polyarylene sulfone ternary hybrid resin, 5-15 parts of silica aerogel, and 1-3 parts of ammonium polyphosphate / zinc borate compound.

[0009] Optionally, in the nano-kaolinite / talc compound, the mass ratio of nano-kaolinite to talc is 1:1 to 3:1;

[0010] In the ammonium polyphosphate / zinc borate compound, the mass ratio of ammonium polyphosphate to zinc borate is 2:1 to 3:1;

[0011] The Zr-Ti-V composite oxide is a bimodal nanoparticle, consisting of large particles of 50–100 nm and small particles of 5–20 nm.

[0012] Optionally, by weight, the organosilicon-epoxy-polyarylene ether sulfone ternary hybrid resin comprises the following raw materials: 50-65 parts of polymethylphenylsiloxane, 20-30 parts of bisphenol A type epoxy resin, and 10-20 parts of fluorine-terminated polyarylene ether sulfone.

[0013] By weight, the polyimide-siloxane hyperbranched resin comprises the following raw materials: polyimide prepolymer: 50-80 parts, benzocyclobutene crosslinking agent: 12-20 parts, hydroxyl-terminated polydimethylsiloxane: 20-35 parts, and vinylsiloxane branched chain: 5-15 parts.

[0014] Secondly, this application provides a method for preparing a powder coating with excellent high-temperature resistance as described in any one of the first aspects, the method comprising:

[0015] The underlying coating is obtained by mixing organosilicon-epoxy-polyarylene ether sulfone ternary hybrid resin, boron nitride, KH-550 modified silicon carbide and Al2O3@SiO2 core-shell particles;

[0016] The intermediate layer coating is obtained by mixing polyimide-siloxane hyperbranched resin, Zr-Ti-V composite oxide and nano-kaolinite / talc powder compound.

[0017] The topcoat is obtained by mixing organosilicon-epoxy-polyarylene ether sulfone ternary hybrid resin, silica aerogel, and ammonium polyphosphate / zinc borate compound.

[0018] Optionally, the preparation method of the organosilicon-epoxy-polyaryl ether sulfone ternary hybrid resin includes:

[0019] Polymethylphenylsiloxane, bisphenol A epoxy resin and fluorine-terminated polyarylether sulfone were added to an organic solvent in a certain proportion to obtain the first mixture.

[0020] The pH of the first mixture was adjusted to 3-4, and the mixture was stirred to form a sol-gel interpenetrating network, thus obtaining the second mixture.

[0021] Add titanate catalyst to the second mixture and heat to 120°C for 2 hours to obtain the organosilicon-epoxy-polyarylene sulfone ternary hybrid resin.

[0022] Optionally, the preparation method of the polyimide-siloxane hyperbranched resin includes:

[0023] Polyimide prepolymer, hydroxyl-terminated polydimethylsiloxane and titanate catalyst were added to an organic solvent and subjected to a condensation reaction at 120°C for 8 hours to obtain a third mixture.

[0024] Vinylsiloxane side chains are added to the third mixture and reacted at 80°C for 4 hours to allow the siloxane to hydrolyze and condense to form branching points, thus obtaining the fourth mixture.

[0025] The benzocyclobutene crosslinking agent and free radical initiator were added to the fourth mixture, and then the temperature was raised to 140°C and reacted for 6 hours under nitrogen protection to open the ring structure of the benzocyclobutene crosslinking agent and crosslink it with the vinylsiloxane branch chain to obtain the fifth mixture.

[0026] The fifth mixture was post-treated and purified to obtain the polyimide-siloxane hyperbranched resin.

[0027] Optionally, the preparation method of the Zr-Ti-V oxide includes:

[0028] Zirconium nitrate solution, tetrabutyl titanate solution, and ammonium metavanadate solution were mixed, and ammonia water was slowly added dropwise to adjust the pH value to 8.8-9.2 to carry out a coprecipitation reaction and form a precipitate; the coprecipitation reaction was carried out at room temperature for 12-24 hours.

[0029] The precipitate was calcined to obtain a Zr-Ti-V composite oxide sintered block; the calcination temperature was 1100-1300℃ and the time was 3-5h.

[0030] The Zr-Ti-V composite oxide sintered bulk material was subjected to high-energy ball milling to obtain the Zr-Ti-V oxide.

[0031] Optionally, the preparation method of the Al2O3@SiO2 core-shell particles includes:

[0032] Hydroxylated Al2O3 was dispersed in KH-550 ethanol solution and stirred at 60°C for 4 hours to allow silane to bond to the surface of Al2O3, thus obtaining modified Al2O3.

[0033] Tetraethyl orthosilicate was added to an ethanol / water mixed solution of modified Al2O3, and ammonia was slowly added dropwise to adjust the pH value to 9-10. The solution was then stirred at 50°C for 6 hours to allow the tetraethyl orthosilicate to hydrolyze and generate SiO2, which was then deposited on the surface of Al2O3. The coated material was obtained by centrifugation.

[0034] The coating material is subjected to high-temperature calcination to obtain the Al2O3@SiO2 core-shell particles; the high-temperature calcination temperature is 550-650℃ and the time is 1.5-2.5h.

[0035] Thirdly, this application provides a high-temperature resistant coating, which is formed by spraying and curing a powder coating with good high-temperature resistance as described in any one of the first aspects. In the high-temperature resistant coating, the boron nitride is oriented along the heat flow direction by a magnetic field and forms an anisotropic thermally conductive and insulating network with the silica aerogel.

[0036] Fourthly, this application provides a method for preparing the high-temperature resistant coating described in the third aspect, the method comprising:

[0037] The base coat is sprayed onto the surface of the substrate, and a transverse magnetic field is applied parallel to the substrate surface to orient the boron nitride flakes along the heat flow direction to form the base coat;

[0038] The intermediate layer coating is sprayed onto the surface of the base layer to form an intermediate layer;

[0039] The topcoat is vertically sprayed onto the surface of the intermediate layer to form an axially heat-conducting and radially heat-insulating network, and then cured to obtain the high-temperature resistant coating.

[0040] The technical solutions provided in this application have the following advantages compared with the prior art:

[0041] This application provides a powder coating with excellent high-temperature resistance. The powder coating consists of a base coat, an intermediate coat, and a top coat. By rationally designing the composition of each coat, the high-temperature resistance, corrosion resistance, and mechanical properties of the high-temperature coating are simultaneously improved.

[0042] First, the base coating is a thermally conductive and wear-resistant layer. Boron nitride (BN) sheets are oriented using a magnetic field to form heat-conducting channels along the heat flow direction (parallel to the substrate surface), rapidly dissipating localized high-temperature heat (such as at the leading edge of engine blades). Simultaneously, KH-550 modified silicon carbide (SiC) achieves a Mohs hardness of 9.5, and combined with Al2O3@SiO2 core-shell particles (Al2O3 core enhancing rigidity, SiO2 shell buffering stress), improving wear life. Furthermore, the core-shell particles absorb thermal stress through plastic deformation, enhancing resistance to thermal shock cycles.

[0043] Secondly, the intermediate coating serves as a transitional buffer layer. The nano-kaolinite / talc composite alleviates thermal expansion mismatch stress through lamellar slippage, improving adhesion retention after thermal cycling. Simultaneously, the Zr-Ti-V composite oxide forms ZrTiO4-VO x Solid solutions inhibit the thermal oxidation of resins. Furthermore, hyperbranched resins enhance interlayer bonding through chemical bonding with the bottom / top layers via terminal functional groups (amino / epoxy groups).

[0044] Finally, the topcoat, serving as a heat-insulating and flame-retardant layer, utilizes a vertical spraying process to directionally deposit silica aerogel onto the surface, forming a radially distributed gradient heat-insulating barrier that significantly reduces heat transfer efficiency along the thickness direction (radial). The ammonium polyphosphate (APP) / zinc borate (ZB) blend provides highly efficient flame retardancy. The thioether bonds in the ternary hybrid resin inhibit acid / alkali corrosion and improve chemical resistance. Attached Figure Description

[0045] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0046] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0047] Figure 1 This is a schematic flowchart illustrating a method for preparing a powder coating with excellent high-temperature resistance, as provided in an embodiment of this application. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0049] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.

[0050] In a first aspect, this application provides a powder coating with excellent high-temperature resistance, the powder coating comprising a base coat, an intermediate coat, and a top coat; wherein, by weight,

[0051] The underlying coating is composed of the following chemical components: 20-40 parts of organosilicon-epoxy-polyaryl ether sulfone ternary hybrid resin, 5-15 parts of boron nitride, 2-6 parts of KH-550 modified silicon carbide, and 3-8 parts of Al2O3@SiO2 core-shell particles.

[0052] The intermediate coating is composed of the following chemical components: 10-20 parts of polyimide-siloxane hyperbranched resin, 3-6 parts of Zr-Ti-V composite oxide, and 1-4 parts of nano-kaolinite / talc powder compound.

[0053] The topcoat is composed of the following chemical components: 10-20 parts of organosilicon-epoxy-polyarylene sulfone ternary hybrid resin, 5-15 parts of silica aerogel, and 1-3 parts of ammonium polyphosphate / zinc borate compound.

[0054] The powder coating in this application consists of a base coat, an intermediate coat, and a top coat. The functions of each layer are as follows:

[0055] The base coating is a thermally conductive and wear-resistant layer. Boron nitride (BN) sheets are oriented using a magnetic field to form heat-conducting channels along the heat flow direction (parallel to the substrate surface), rapidly dissipating localized high-temperature heat (such as at the leading edge of engine blades). Simultaneously, KH-550 modified silicon carbide (SiC) achieves a Mohs hardness of 9.5, and combined with Al2O3@SiO2 core-shell particles (Al2O3 core for rigidity enhancement, SiO2 shell for stress buffering), it improves wear life. Furthermore, the core-shell particles absorb thermal stress through plastic deformation, enhancing resistance to thermal shock cycles.

[0056] The intermediate coating layer serves as a transitional buffer layer. The nano-kaolinite / talc compound alleviates thermal expansion mismatch stress through lamellar slippage, improving adhesion retention after thermal cycling. Simultaneously, the Zr-Ti-V composite oxide forms ZrTiO4-VO. x Solid solutions inhibit the thermal oxidation of resins. Furthermore, hyperbranched resins enhance interlayer bonding through chemical bonding with the bottom / top layers via terminal functional groups (amino / epoxy groups).

[0057] The topcoat, serving as a heat-insulating and flame-retardant layer, utilizes a vertical spraying process to directionally deposit silica aerogel onto the surface, forming a radially distributed gradient heat-insulating barrier that significantly reduces heat transfer efficiency along the thickness direction (radial). The combination of ammonium polyphosphate (APP) and zinc borate (ZB) provides highly efficient flame retardancy. The thioether bonds in the ternary hybrid resin inhibit acid / alkali corrosion and improve chemical resistance.

[0058] After the base coat, intermediate coat, and top coat are sprayed and cured to form a coating, although the base coat, intermediate coat, and top coat are independent layers, there is a certain degree of component penetration and interaction at the interface area. Specifically, the roles and interactions of the components of the powder coating with excellent high-temperature resistance provided in this application are as follows:

[0059] Organosilicon-epoxy-polyarylene ether sulfone ternary hybrid resin: The organosilicon component provides the flexibility and high-temperature resistance of the main chain. Its high Si-O bond energy ensures stability below 400℃, preventing thermal decomposition. The epoxy resin forms a three-dimensional network through cross-linking of epoxy groups, imparting high adhesion and impact resistance to the coating; after curing, it forms a rigid framework, inhibiting high-temperature creep. The aromatic ring structure of polyarylene ether sulfone (PAES) provides excellent thermal stability and resistance to thermal oxidation, while the thioether bonds enhance chemical corrosion resistance. The three components form an interpenetrating network (IPN) via a sol-gel method. The organosilicon disperses the rigid regions of PAES, while the epoxy resin fills the interfacial voids, giving the coating both flexibility and rigidity within the temperature range of -50 to 400℃, and reducing the coefficient of thermal expansion.

[0060] Boron nitride (BN): Hexagonal BN crystals (h-BN) are oriented along the (002) crystal plane, with an in-plane thermal conductivity as high as 300 W / (m·K), forming a rapid axial heat dissipation channel. Simultaneously, its high volume resistivity prevents leakage or arc damage at high temperatures. Furthermore, the layered structure reduces the coefficient of friction and improves the coating's wear resistance. Magnetic field orientation technology ensures that the BN layers are parallel to the coating surface, with an axial thermal conductivity >50 W / (m·K), forming a "thermal diode" effect with the radial thermal insulation filler (silica aerogel), reducing the substrate temperature rise.

[0061] KH-550 modified silicon carbide: The amino groups of KH-550 react with the hydroxyl groups on the surface of silicon carbide (SiC) to form -Si-O-Si- bonds, improving compatibility with resin and increasing interfacial shear strength. The SiC hardness (Mohs 9.5) combined with the resin enhances the coating's wear resistance. SiC and Al2O3@SiO2 core-shell particles form a "hard-soft" composite structure, with SiC bearing the main wear stress and the core-shell particles buffering the impact, thus extending the coating's lifespan.

[0062] Al2O3@SiO2 core-shell particles: The Al2O3 core (50–100 nm) provides high modulus, while the SiO2 shell (10–30 nm) absorbs thermal stress through plastic deformation, resulting in thermal shock resistance >50 cycles. Simultaneously, the SiO2 shell blocks acid / alkali corrosion, improving salt spray resistance. The core-shell particles, together with Zr-Ti-V oxides, inhibit interfacial crack propagation, enhancing the coating's fracture toughness.

[0063] Polyimide-siloxane hyperbranched resin: The aromatic heterocyclic structure of the polyimide (PI) backbone provides extreme temperature resistance, and rigid segments inhibit high-temperature chain slippage. Siloxane branches, grafted with KH-550 Si-O-Si segments, enhance flexibility, reduce coating brittleness, and increase elongation at break. The multi-terminal functional groups (such as amino and epoxy groups) of the hyperbranched structure reinforce chemical bonding with the ternary hybrid resin, forming a dense cross-linked network and reducing microcracks. As a "molecular reinforcing agent," the hyperbranched resin absorbs heat during the decomposition of siloxane branches at high temperatures (>300℃), delaying the thermal degradation of the matrix while maintaining the structural integrity of the PI backbone.

[0064] Nano-kaolinite / talc compound: Kaolinite Al2Si2O 5( OH)4 and talc Mg3Si4O 10 Nanosheets of (OH)₂ are interspersed within the resin, enhancing hardness and scratch resistance. Simultaneously, the parallel arrangement of the sheets extends the gas diffusion path, increasing the oxygen index. The interlayer slippage ability of talc alleviates thermal stress and complements the rigidity of kaolinite, allowing the coating to maintain over 95% adhesion even after thermal cycling (-196 to 600°C).

[0065] Zr-Ti-V composite oxides: ZrO2 provides a high-temperature phase transformation toughening effect (tetragonal phase → monoclinic phase), TiO2 enhances interfacial bonding, and V2O5 inhibits precipitate coarsening by forming a low-mobility grain boundary segregation layer. The multi-element synergy of the composite oxides can form a metastable phase, delaying the aggregation of precipitates at high temperatures. Simultaneously, ZrTiO4 and V2O5... x It forms a solid solution, exhibits no phase transformation below 1200℃, and its coefficient of thermal expansion matches the matrix, preventing coating cracking. Furthermore, V... 4+ / V 5+ Redox pairs absorb free radicals and delay the thermal oxidation of the resin. Zr-Ti-V oxides react with ammonium polyphosphate to form a ZrP2O7-TiP2O7 glass phase, which covers the surface of the char layer and improves the flame retardant efficiency.

[0066] Silica aerogel: It inhibits heat conduction of gas molecules through the Knudsen effect, reducing radial thermal conductivity. Vertical spraying forms a gradient thermal insulation layer, which, in conjunction with the axial thermal conduction of silica, allows for a temperature difference of up to 500°C between the coating surface (high-temperature side) and the substrate (low-temperature side).

[0067] Ammonium polyphosphate / zinc borate blend: Ammonium polyphosphate (APP) decomposes at 250–400℃ to form polyphosphoric acid, which catalyzes the dehydration of resin to form char, creating an expanded char layer that blocks oxygen and heat. Zinc borate (ZB) forms a B2O3 glass layer above 350℃, covering the char surface and suppressing smoke and dripping. When APP / ZB is blended, the char residue after combustion is significantly better than that of a single flame retardant.

[0068] This formulation achieves high-temperature resistance and intelligent thermal management through multi-scale filler design, functional additive coupling, and interface synergistic optimization. Its overall performance significantly surpasses that of single-component systems. The synergistic effects between the components are as follows:

[0069] (1) Synergistic thermal management: The thermal conduction-insulation network of boron nitride (axial) + aerogel (radial) is integrated. The directional arrangement of BN forms a fast axial thermal conduction path, which leads to local hot spots. The vertical spraying of aerogel constructs a radial thermal insulation barrier, which reduces the overall heat flux.

[0070] (2) Synergistic mechanical properties: The rigid-flexible composite structure of ternary hybrid resin (rigid) + hyperbranched resin (flexible) provides high strength, while the hyperbranched structure absorbs stress through molecular chain entanglement and prevents brittle fracture.

[0071] (3) Synergistic effect of high temperature stability: Zr-Ti-V oxide (nanoscale) + Al2O3@SiO2 (core and shell) multi-scale fillers complement each other. Zr-Ti-V bimodal particles fill micropores to inhibit resin decomposition at high temperature, and Al2O3@SiO2 buffers thermal stress and prevents interface peeling.

[0072] (4) Interface enhancement synergy: KH-550 modified silicon carbide + nano kaolinite / talc powder surface modification and gradient dispersion, silane coupling agent enhances the interface bonding between silicon carbide and resin; dense filling of kaolinite / talc powder reduces stress concentration.

[0073] In some embodiments, the mass ratio of nano-kaolinite to talc in the nano-kaolinite / talc compound is 1:1 to 3:1.

[0074] In the ammonium polyphosphate / zinc borate compound, the mass ratio of ammonium polyphosphate to zinc borate is 2:1 to 3:1.

[0075] In some embodiments, the Zr-Ti-V composite oxide is a bimodal nanoparticle composed of large particles of 50–100 nm and small particles of 5–20 nm.

[0076] It should be noted that the large-size precipitates of 50nm to 100nm mainly pin grain boundaries and suppress grain coarsening at high temperatures; while the small-size precipitates of 5nm to 20nm restrict dislocation movement through the dislocation pinning effect, thereby improving the coating's high-temperature creep resistance.

[0077] In some embodiments, the organosilicon-epoxy-polyarylene ether sulfone ternary hybrid resin comprises, by weight, the following raw materials: 50-65 parts of polymethylphenylsiloxane, 20-30 parts of bisphenol A type epoxy resin, and 10-20 parts of fluorine-terminated polyarylene ether sulfone.

[0078] By weight, the polyimide-siloxane hyperbranched resin comprises the following raw materials: polyimide prepolymer: 50-80 parts, benzocyclobutene crosslinking agent: 12-20 parts, hydroxyl-terminated polydimethylsiloxane: 20-35 parts, and vinylsiloxane branched chain: 5-15 parts.

[0079] Figure 1 This is a schematic flowchart illustrating a method for preparing a powder coating with excellent high-temperature resistance, as provided in an embodiment of this application.

[0080] Secondly, such as Figure 1 As shown, this application provides a method for preparing a powder coating with excellent high-temperature resistance as described in any one of the first aspects, the method comprising:

[0081] S1. Mix organosilicon-epoxy-polyaryl ether sulfone ternary hybrid resin, boron nitride, KH-550 modified silicon carbide and Al2O3@SiO2 core-shell particles to obtain the underlying coating.

[0082] It should be noted that step S1 specifically involves: placing the organosilicon-epoxy-polyarylene sulfone ternary hybrid resin in a mixing container and heating it to 60–80°C to soften it and increase its fluidity. Boron nitride powder is then added to the resin and mixed using a high-speed disperser or ball mill to ensure uniform dispersion of the boron nitride. KH-550 modified silicon carbide is added, and mixing continues to ensure sufficient contact and coating of the silicon carbide particles with the resin. Finally, Al2O3@SiO2 core-shell particles are added and stirred at low speed to avoid damaging the core-shell structure and ensure uniform particle distribution.

[0083] In some embodiments, the preparation method of the organosilicon-epoxy-polyarylene sulfone ternary hybrid resin includes:

[0084] Polymethylphenylsiloxane, bisphenol A type epoxy resin, and fluorinated terminal polyarylene ether sulfone were added to an organic solvent in a certain proportion to obtain a first mixture; the pH of the first mixture was adjusted to 3-4, and the mixture was stirred to form a sol-gel interpenetrating network to obtain a second mixture; a titanate catalyst was added to the second mixture, and the mixture was heated to 120°C and reacted for 2 hours to obtain the organosilicon-epoxy-polyarylene ether sulfone ternary hybrid resin; the mass of the titanate catalyst was 0.5-1.5% of the mass of the second mixture.

[0085] In the preparation of organosilicon-epoxy-polyaryl ether sulfone ternary hybrid resins, adjusting the pH to 3-4 can promote the ring-opening reaction between silanol groups (Si-OH) and epoxy groups, forming Si-OC covalent bonds and constructing an interpenetrating polymer network (IPN). Titanate catalysis can accelerate the sol-gel conversion and increase the resin crosslinking density.

[0086] In some embodiments, the method for preparing the Al2O3@SiO2 core-shell particles includes:

[0087] Hydroxylated Al2O3 was dispersed in a KH-550 ethanol solution and stirred at 60°C for 4 hours to allow silane bonding to the Al2O3 surface, thus obtaining modified Al2O3. Tetraethyl orthosilicate was added to the ethanol / water mixture of the modified Al2O3, and ammonia was slowly added dropwise to adjust the pH to 9-10. The mixture was then stirred at 50°C for 6 hours to allow the tetraethyl orthosilicate to hydrolyze and generate SiO2, which was then deposited on the Al2O3 surface. The coated material was obtained by centrifugation. The coated material was then calcined at high temperature to obtain Al2O3@SiO2 core-shell particles. The high-temperature calcination temperature was 550-650°C, and the time was 1.5-2.5 hours.

[0088] In the preparation of Al2O3@SiO2 core-shell particles, a silane coupling agent bonds the hydroxyl groups on the Al2O3 surface, improving the uniformity of SiO2 coating. Calcination at 550–650℃ densifies the amorphous SiO2 shell, significantly enhancing its acid resistance and thermal shock resistance.

[0089] S2. Mix polyimide-siloxane hyperbranched resin, Zr-Ti-V composite oxide and nano-kaolinite / talc powder compound to obtain the intermediate layer coating.

[0090] It should be noted that step S2 specifically involves: placing the polyimide-siloxane hyperbranched resin in a mixing container and heating it to a suitable temperature to soften it. Then, adding the Zr-Ti-V composite oxide and mixing it using a high-speed disperser to ensure the oxide particles are uniformly dispersed in the resin. Next, adding the nano-kaolinite / talc compound and continuing mixing to ensure the nanoparticles are fully in contact with and coated on the resin.

[0091] In some embodiments, the method for preparing the polyimide-siloxane hyperbranched resin includes:

[0092] Polyimide prepolymer, hydroxyl-terminated polydimethylsiloxane, and titanate catalyst were added to an organic solvent and subjected to a condensation reaction at 120°C for 8 hours to obtain a third mixture. Vinylsiloxane branches were added to the third mixture and reacted at 80°C for 4 hours to allow the siloxane to hydrolyze and condense to form branching points, resulting in a fourth mixture. Benzocyclobutene crosslinking agent and free radical initiator were added to the fourth mixture, and then the temperature was raised to 140°C and reacted under nitrogen protection for 6 hours to allow the cyclic structure of the benzocyclobutene crosslinking agent to open and crosslink with the vinylsiloxane branches, resulting in a fifth mixture. The fifth mixture was post-treated and purified to obtain the polyimide-siloxane hyperbranched resin.

[0093] In the preparation of polyimide-siloxane hyperbranched resin, when vinyl siloxane branches are introduced, branching points are formed through hydrolysis and condensation, achieving a balance between flexibility and temperature resistance. During benzocyclobutene crosslinking, the tetrafunctional crosslinking agent opens its ring and branches with the vinyl branches, forming a three-dimensional hyperbranched network and increasing the thermal decomposition temperature.

[0094] In some embodiments, the method for preparing the Zr-Ti-V oxide includes:

[0095] Zirconium nitrate solution, tetrabutyl titanate solution, and ammonium metavanadate solution were mixed, and ammonia water was slowly added dropwise to adjust the pH value to 8.8–9.2 to carry out a co-precipitation reaction to form a precipitate; the co-precipitation reaction was carried out at room temperature for 12–24 hours; the precipitate was calcined to obtain a Zr-Ti-V composite oxide sintered block; the calcination temperature was 1100–1300℃ for 3–5 hours; the Zr-Ti-V composite oxide sintered block was then subjected to high-energy ball milling to obtain the Zr-Ti-V oxide.

[0096] In the preparation of Zr-Ti-V oxides, co-precipitation at pH 8.8–9.2 ensures that Zr... 4+ Ti 4+ V 5+ Complete co-precipitation, avoiding component segregation, and forming a homogeneous solid solution (ZrTiO4-VO) after calcination. x Bimodal particles can be obtained through high-energy ball milling.

[0097] S3. Mix the organosilicon-epoxy-polyarylene ether sulfone ternary hybrid resin, silica aerogel and ammonium polyphosphate / zinc borate compound to obtain the topcoat.

[0098] It should be noted that the silicone-epoxy-polyarylene sulfone ternary hybrid resin in the topcoat is the same as that in the basecoat to ensure resin quality. Step S3 specifically involves: placing the silicone-epoxy-polyarylene sulfone ternary hybrid resin in a mixing container and heating it to a suitable temperature. Slowly add the silica aerogel, mixing with a low-speed stirrer to avoid damaging the aerogel structure. Add the ammonium polyphosphate / zinc borate compound and continue mixing to ensure the flame retardant is uniformly dispersed in the resin.

[0099] This application utilizes a magnetic field to orient boron nitride (BN), causing BN sheets to align along the heat flow direction (parallel to the coating surface), forming axially high thermal conductivity channels to rapidly dissipate heat from localized high-temperature areas (such as engine combustion chambers). The (002) crystal plane of BN exhibits anisotropic thermal conductivity; the magnetic field induces its crystal plane orientation, enhancing in-plane thermal conductivity. By vertically spraying silica aerogel, layer by layer of silica aerogel is applied in the vertical direction, forming a radially ultra-low thermal conductivity thermal barrier that prevents heat transfer to the substrate.

[0100] Thirdly, this application provides a high-temperature resistant coating, which is formed by spraying and curing a powder coating with good high-temperature resistance as described in any one of the first aspects. In the high-temperature resistant coating, the boron nitride is oriented along the heat flow direction by a magnetic field and forms an anisotropic thermally conductive and insulating network with the silica aerogel.

[0101] This application achieves a breakthrough in the performance of high-temperature resistant coatings through multi-scale structural design and precise interface control, making them suitable for high-end fields such as aerospace, nuclear power, and new energy vehicles.

[0102] Fourthly, this application provides a method for preparing the high-temperature resistant coating described in the third aspect, the method comprising:

[0103] The base coat is sprayed onto the surface of the substrate, and a transverse magnetic field is applied parallel to the substrate surface to orient the boron nitride flakes along the heat flow direction to form the base coat;

[0104] The intermediate layer coating is sprayed onto the surface of the base layer to form an intermediate layer;

[0105] The topcoat is vertically sprayed onto the surface of the intermediate layer to form an axially heat-conducting and radially heat-insulating network, and then cured to obtain the high-temperature resistant coating.

[0106] In some embodiments, the magnetic field strength of the transverse magnetic field is ≥1T and the application time is ≥30min.

[0107] It should be noted that the magnetic field strength of the transverse magnetic field must be ≥1T (Tesla), and the application time must be ≥30min, in order to overcome the diamagnetism of BN and the viscous resistance of the system, and ensure that the layers are aligned along the heat flow direction (e.g., parallel to the coating surface).

[0108] This application achieves a comprehensive improvement in the thermal management, mechanical strength, environmental resistance, and safety of high-temperature resistant coatings through component synergy, structural design, and process innovation, providing an innovative solution for material protection in extreme environments. Specifically, it exhibits the following core advantages:

[0109] (1) Excellent high temperature resistance: Through the synergistic effect of the rigid-flexible resin matrix and the high temperature stable filler, the heat resistance limit and thermal stability of the coating are significantly improved, effectively inhibiting thermal oxidation decomposition and structural failure under high temperature environment, and ensuring long-term reliability under extreme temperature.

[0110] (2) Intelligent thermal management capability: Combining the dual design of directional heat conduction and gradient heat insulation, it achieves the synergistic effect of rapid heat conduction and efficient heat barrier, protecting the substrate from heat damage in high-temperature environments, while optimizing the uniformity of heat distribution.

[0111] (3) Excellent mechanical properties and durability: The introduction of nano-reinforced fillers significantly improves the hardness, wear resistance and impact resistance of the coating. Interface optimization technology enhances the adhesion between the coating and the substrate, effectively extending the service life and resisting complex stress environments.

[0112] (4) Corrosion resistance and environmental tolerance: The design of the core-shell structure filler and dense cross-linked network endows the coating with excellent chemical corrosion resistance, thermal shock resistance and environmental erosion resistance, which can meet the protection requirements under harsh working conditions.

[0113] (5) High efficiency flame retardancy and safety protection: The synergistic effect of the flame retardant system forms a dense protective layer, which effectively inhibits the spread of flames and reduces smoke release, improves the safety and environmental protection of materials, and meets the protection standards for high-risk scenarios.

[0114] (6) Process-driven structural optimization: Innovative processes such as magnetic field orientation and gradient spraying ensure the precise distribution and microstructure control of functional fillers, maximize the material performance potential, and realize the customization of coating functions and structures.

[0115] (7) Wide applicability: It is suitable for high-end industrial fields such as thermal barrier coatings for aerospace engines, protection of nuclear power equipment, and fire protection for new energy vehicle batteries. It combines lightweight, long-lasting protection and adaptability to complex working conditions.

[0116] The present application is further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the application. Experimental methods in the following embodiments that do not specify specific conditions are generally determined according to industry standards. If there is no corresponding industry standard, then common international standards, conventional conditions, or conditions recommended by the manufacturer are followed.

[0117] Example 1

[0118] This embodiment provides a powder coating with excellent high-temperature resistance. The powder coating consists of a base coat, an intermediate coat, and a top coat; wherein, by weight,

[0119] The underlying coating is composed of the following chemical components: 30 parts of organosilicon-epoxy-polyarylene ether sulfone ternary hybrid resin, 10 parts of boron nitride, 4 parts of KH-550 modified silicon carbide, and 6 parts of Al2O3@SiO2 core-shell particles.

[0120] The intermediate layer coating is composed of the following chemical components: 15 parts of polyimide-siloxane hyperbranched resin, 4 parts of Zr-Ti-V composite oxide, and 2 parts of nano-kaolinite / talc powder compound.

[0121] The topcoat is composed of the following chemical components: 16 parts of organosilicon-epoxy-polyarylene ether sulfone ternary hybrid resin, 11 parts of silica aerogel, and 2 parts of ammonium polyphosphate / zinc borate compound.

[0122] In the nano-kaolinite / talc compound, the mass ratio of nano-kaolinite to talc is 2:1.

[0123] In the ammonium polyphosphate / zinc borate compound, the ratio of ammonium polyphosphate to zinc borate is 2.5:1;

[0124] The Zr-Ti-V composite oxide is a bimodal nanoparticle, consisting of large particles of 50-100 nm and small particles of 5-20 nm, with a mass ratio of 1:1.

[0125] The organosilicon-epoxy-polyarylene ether sulfone ternary hybrid resin comprises the following raw materials in parts by weight: 60 parts of polymethylphenylsiloxane, 25 parts of bisphenol A type epoxy resin, and 15 parts of fluorine-terminated polyarylene ether sulfone.

[0126] By weight, the polyimide-siloxane hyperbranched resin comprises the following raw materials: polyimide: 50 parts, benzocyclobutene crosslinking agent: 15 parts, hydroxyl-terminated polydimethylsiloxane: 25 parts, and vinylsiloxane branched chain: 10 parts.

[0127] Based on the above-mentioned powder coatings, this embodiment also provides a method for preparing a powder coating with excellent high-temperature resistance as described in any one of the above-mentioned methods, the method comprising:

[0128] S11. Mix organosilicon-epoxy-polyaryl ether sulfone ternary hybrid resin, boron nitride, KH-550 modified silicon carbide and Al2O3@SiO2 core-shell particles to obtain the underlying coating.

[0129] The preparation method of the organosilicon-epoxy-polyarylene ether sulfone ternary hybrid resin includes: heating polyarylene ether sulfone (CAS No. 9002-88-4) to 120°C, adding trifluoromethylphenol (molar amount of which is 2% of the total amount of polyarylene ether sulfone monomer), continuing the reaction for 3 hours, and attaching fluorine groups to the polymer chain ends through nucleophilic substitution reaction. After cooling to room temperature, the reaction solution is dropwise into a deionized water / ethanol mixed solution to precipitate the polymer. The polymer is then filtered, washed until neutral, and vacuum dried for 24 hours to obtain fluorine-terminated polyarylene ether sulfone; polymethylphenylsiloxane (CAS No. 63148-58-3) and bisphenol A are added in proportion. Epoxy resin (CAS No. 25085-99-8) and fluorinated terminal polyarylene sulfone were added to N-methylpyrrolidone (NMP) solvent (mass ratio 1:2) to obtain a first mixture; the pH of the first mixture was adjusted to 3.5, and the mixture was stirred at 60°C for 6 hours to form a sol-gel interpenetrating network to obtain a second mixture; a titanate catalyst (CAS No. 5593-70-4, the mass of the titanate catalyst was 1% of the total mass of the second mixture) was added to the second mixture, and the mixture was heated to 120°C for 2 hours to obtain the organosilicon-epoxy-polyarylene sulfone ternary hybrid resin.

[0130] The preparation method of KH-550 modified silicon carbide includes: immersing SiC powder (CAS number 409-21-2) in dilute hydrochloric acid, ultrasonically treating for 30 minutes to remove surface metal oxides and impurities; repeatedly washing with deionized water until the pH of the filtrate is approximately 7; vacuum drying at 100℃ for 6 hours to obtain activated SiC. Dissolving KH-550 at a mass ratio of 3% (relative to SiC) in an ethanol / water mixture, adjusting the pH to 4-5 with acetic acid; stirring at room temperature for 30 minutes to fully hydrolyze KH-550 to generate silanol (Si-OH). Adding the activated SiC to the hydrolyzed KH-550 solution, stirring at 70℃ for 3 hours; the silanol condenses with the hydroxyl groups (-OH) on the SiC surface to form Si-O-Si covalent bonds, achieving surface grafting of amino groups (-NH2). Centrifuge at 4000 rpm for 10 minutes to collect the modified SiC; wash three times with anhydrous ethanol to remove unreacted KH-550, and obtain KH-550 modified silicon carbide.

[0131] The preparation method of the Al2O3@SiO2 core-shell particles includes: dispersing hydroxylated Al2O3 in a KH-550 ethanol solution and stirring at 60°C for 4 hours to allow silanes to bond to the surface of Al2O3, thereby obtaining modified Al2O3; adding tetraethyl orthosilicate to the ethanol / water mixed solution of the modified Al2O3, and slowly adding ammonia to adjust the pH to 9.5, then stirring at a constant temperature of 50°C for 6 hours to allow the tetraethyl orthosilicate to hydrolyze and generate SiO2, which is then deposited on the surface of Al2O3, and centrifuging to obtain the coating; and calcining the coating at a high temperature to obtain the Al2O3@SiO2 core-shell particles; the high temperature calcination is 600°C for 2 hours.

[0132] S21. Polyimide-siloxane hyperbranched resin, Zr-Ti-V composite oxide and nano-kaolinite / talc powder compound are mixed to obtain the intermediate layer coating.

[0133] The preparation method of the polyimide-siloxane hyperbranched resin includes: mixing octamethylcyclotetrasiloxane with concentrated sulfuric acid (0.7 wt%) in toluene, heating to 90°C under nitrogen protection, stirring for 5 hours, cooling to 50°C, slowly adding deionized water (2.5 times the molar amount of octamethylcyclotetrasiloxane), and continuing the reaction for 1 hour to hydrolyze the terminal siloxane bonds (Si-O-Si) to generate hydroxyl groups (-OH), washing with NaHCO3 solution, separating to remove the aqueous phase, and removing the solvent by vacuum distillation to obtain hydroxyl-terminated polydimethylsiloxane; polycondensing biphenyl tetracarboxylic dianhydride (BPDA) and 4,4'-diaminodiphenyl ether (ODA) in NMP (80°C, 6 hours) to generate a polyamic acid prepolymer; and combining the polyimide prepolymer, hydroxyl-terminated polydimethylsiloxane, and titanium. An ester catalyst was added to dimethyl sulfoxide and subjected to a condensation reaction at 120°C for 8 hours to obtain a third mixture. A vinyl siloxane branch (vinyltrimethoxysilane, CAS No. 2768-02-7) was added to the third mixture and reacted at 80°C for 4 hours to allow the siloxane to hydrolyze and condense to form branching points, resulting in a fourth mixture. A benzocyclobutene crosslinking agent (CAS No. 694-87-1) and a free radical initiator (diisopropylbenzene peroxide) were added to the fourth mixture, and the mixture was then heated to 140°C and reacted under nitrogen protection for 6 hours to allow the cyclic structure of the benzocyclobutene crosslinking agent to open and crosslink with the vinyl siloxane branch, resulting in a fifth mixture. The fifth mixture was then post-treated and purified to obtain the polyimide-siloxane hyperbranched resin.

[0134] The preparation method of the Zr-Ti-V oxide includes: mixing zirconium nitrate solution, tetrabutyl titanate solution and ammonium metavanadate solution, and slowly adding ammonia water to adjust the pH value to 9.0 to carry out a co-precipitation reaction to form a precipitate; the co-precipitation reaction is carried out at room temperature for 20 hours; the precipitate is calcined to obtain a Zr-Ti-V composite oxide sintered block; the calcination temperature is 1200℃ for 4 hours; the Zr-Ti-V composite oxide sintered block is subjected to high-energy ball milling to obtain the Zr-Ti-V oxide.

[0135] The preparation method of the nano-kaolinite / talc compound includes: drying nano-kaolinite and talc powder separately at 150°C for 2 hours to remove adsorbed moisture; surface treating kaolinite / talc powder with silane coupling agent KH-550 to improve compatibility with resin; adding the dried kaolinite and talc powder to a high-speed mixer in proportion and mixing at 1000 rpm for 60 minutes to ensure uniform dispersion; passing through a 200-mesh sieve to remove agglomerated particles to obtain the nano-kaolinite / talc compound.

[0136] S31. The organosilicon-epoxy-polyarylene ether sulfone ternary hybrid resin, silica aerogel (Forsmann brand aerogel powder, CAS number 102262-30-6) and ammonium polyphosphate / zinc borate compound are mixed to obtain the surface coating.

[0137] The preparation method of the ammonium polyphosphate / zinc borate compound includes: drying ammonium polyphosphate (CAS No. 68333-79-9) and zinc borate at 80°C for 4 hours to avoid moisture absorption and clumping; adding APP and ZB to a high-speed mixer in proportion and mixing at 500 rpm for 30 minutes to ensure uniform dispersion; passing through a 100-mesh sieve; sealing and storing in a dry environment to obtain the ammonium polyphosphate / zinc borate compound.

[0138] Based on the above-mentioned powder coating, this embodiment also provides a high-temperature resistant coating, which is formed by spraying and curing the above-mentioned powder coating. In the high-temperature resistant coating, the boron nitride is oriented along the heat flow direction by a magnetic field and forms an anisotropic thermally conductive and insulating network with the silica aerogel.

[0139] Based on the above-mentioned high-temperature resistant coating, this embodiment also provides a method for preparing the high-temperature resistant coating, including the following steps:

[0140] The base coat is sprayed onto the surface of the substrate, and a transverse magnetic field is applied parallel to the substrate surface to orient the boron nitride (BN) flakes along the heat flow direction, forming the base coat. The spraying method is electrostatic spraying (70kV, 0.5MPa, spray distance 25cm), with a thickness of 80μm. A 1.2T transverse magnetic field (parallel to the substrate) is applied for 30 minutes. The intermediate layer coat is then sprayed onto the surface of the base coat to form the intermediate layer. The spraying method is electrostatic spraying without a magnetic field, with a thickness of 50μm. After spraying, the temperature is increased to 150℃ at 3℃ / min for 1 hour for pre-curing to release interlayer stress. The top coat coat is then vertically sprayed onto the surface of the intermediate layer to form an axially conductive and radially insulating network. This is done using vertical low-pressure spraying (0.3MPa, nozzle 0.4mm), with a thickness of 50μm, forming a radial insulating barrier. Pre-curing is performed at 80℃ for 1 hour to fix the BN oriented structure. The temperature is then increased to 180℃ at 5℃ / min and held for 2 hours to allow the ternary hybrid resin to fully cross-link. Then, under Ar gas protection, the temperature was increased to 320℃ at 3℃ / min and held for 1 hour to activate the temperature resistance of the polyimide segments. The temperature was then reduced to room temperature at ≤2℃ / min to reduce the risk of thermal stress cracking, thus obtaining the high-temperature resistant coating.

[0141] Example 2

[0142] This embodiment is based on the disclosure in Embodiment 1, with the following modifications:

[0143] This embodiment provides a powder coating with excellent high-temperature resistance. The powder coating consists of a base coat, an intermediate coat, and a top coat; wherein, by weight,

[0144] The underlying coating is composed of the following chemical components: 38 parts of organosilicon-epoxy-polyarylene ether sulfone ternary hybrid resin, 5 parts of boron nitride, 6 parts of KH-550 modified silicon carbide, and 3 parts of Al2O3@SiO2 core-shell particles.

[0145] The intermediate layer coating is composed of the following chemical components: 18 parts of polyimide-siloxane hyperbranched resin, 3 parts of Zr-Ti-V composite oxide, and 1 part of nano-kaolinite / talc powder compound.

[0146] The topcoat is composed of the following chemical components: 10 parts of organosilicon-epoxy-polyarylene ether sulfone ternary hybrid resin, 15 parts of silica aerogel, and 1 part of ammonium polyphosphate / zinc borate compound.

[0147] In the nano-kaolinite / talc compound, the mass ratio of nano-kaolinite to talc is 3:1.

[0148] In the ammonium polyphosphate / zinc borate compound, the ratio of ammonium polyphosphate to zinc borate is 3:1;

[0149] The Zr-Ti-V composite oxide is a bimodal nanoparticle, consisting of large particles of 50-100 nm and small particles of 5-20 nm, with a mass ratio of 1:2.

[0150] The organosilicon-epoxy-polyarylene ether sulfone ternary hybrid resin comprises the following raw materials in parts by weight: 65 parts of polymethylphenylsiloxane, 20 parts of bisphenol A type epoxy resin, and 15 parts of fluorine-terminated polyarylene ether sulfone.

[0151] By weight, the polyimide-siloxane hyperbranched resin comprises the following raw materials: polyimide: 55 parts, benzocyclobutene crosslinking agent: 20 parts, hydroxyl-terminated polydimethylsiloxane: 20 parts, and vinylsiloxane branched chain: 5 parts.

[0152] Example 3

[0153] This embodiment is based on the disclosure in Embodiment 1, with the following modifications:

[0154] This embodiment provides a powder coating with excellent high-temperature resistance. The powder coating consists of a base coat, an intermediate coat, and a top coat; wherein, by weight,

[0155] The underlying coating is composed of the following chemical components: 20 parts of organosilicon-epoxy-polyarylene ether sulfone ternary hybrid resin, 14 parts of boron nitride, 2 parts of KH-550 modified silicon carbide, and 8 parts of Al2O3@SiO2 core-shell particles.

[0156] The intermediate layer coating is composed of the following chemical components: 20 parts of polyimide-siloxane hyperbranched resin, 6 parts of Zr-Ti-V composite oxide, and 4 parts of nano-kaolinite / talc powder compound.

[0157] The topcoat is composed of the following chemical components: 18 parts of organosilicon-epoxy-polyarylene ether sulfone ternary hybrid resin, 5 parts of silica aerogel, and 3 parts of ammonium polyphosphate / zinc borate compound.

[0158] In the nano-kaolinite / talc compound, the mass ratio of nano-kaolinite to talc is 1:1.

[0159] In the ammonium polyphosphate / zinc borate compound, the ratio of ammonium polyphosphate to zinc borate is 2:1;

[0160] The Zr-Ti-V composite oxide is a bimodal nanoparticle, consisting of large particles of 50-100 nm and small particles of 5-20 nm, with a mass ratio of 2:1.

[0161] The organosilicon-epoxy-polyarylene ether sulfone ternary hybrid resin comprises the following raw materials in parts by weight: 50 parts of polymethylphenylsiloxane, 30 parts of bisphenol A type epoxy resin, and 20 parts of fluorine-terminated polyarylene ether sulfone.

[0162] By weight, the polyimide-siloxane hyperbranched resin comprises the following raw materials: polyimide: 50 parts, benzocyclobutene crosslinking agent: 20 parts, hydroxyl-terminated polydimethylsiloxane: 20 parts, and vinylsiloxane branched chain: 10 parts.

[0163] Example 4

[0164] This embodiment is based on the disclosure in Embodiment 1, with the following modifications:

[0165] This embodiment provides a powder coating with excellent high-temperature resistance. The powder coating consists of a base coat, an intermediate coat, and a top coat; wherein, by weight,

[0166] The underlying coating is composed of the following chemical components: 32 parts of organosilicon-epoxy-polyarylene ether sulfone ternary hybrid resin, 12 parts of boron nitride, 5 parts of KH-550 modified silicon carbide, and 4 parts of Al2O3@SiO2 core-shell particles.

[0167] The intermediate layer coating is composed of the following chemical components: 20 parts of polyimide-siloxane hyperbranched resin, 4 parts of Zr-Ti-V composite oxide, and 2 parts of nano-kaolinite / talc powder compound.

[0168] The topcoat is composed of the following chemical components: 12 parts of organosilicon-epoxy-polyarylene ether sulfone ternary hybrid resin, 8 parts of silica aerogel, and 1 part of ammonium polyphosphate / zinc borate compound.

[0169] In the nano-kaolinite / talc compound, the mass ratio of nano-kaolinite to talc is 1:1.

[0170] In the ammonium polyphosphate / zinc borate compound, the ratio of ammonium polyphosphate to zinc borate is 3:1;

[0171] The Zr-Ti-V composite oxide is a bimodal nanoparticle, consisting of large particles of 50-100 nm and small particles of 5-20 nm, with a mass ratio of 1:1.

[0172] The organosilicon-epoxy-polyarylene ether sulfone ternary hybrid resin comprises the following raw materials in parts by weight: 60 parts of polymethylphenylsiloxane, 22 parts of bisphenol A type epoxy resin, and 18 parts of fluorine-terminated polyarylene ether sulfone.

[0173] By weight, the polyimide-siloxane hyperbranched resin comprises the following raw materials: polyimide: 55 parts, benzocyclobutene crosslinking agent: 15 parts, hydroxyl-terminated polydimethylsiloxane: 25 parts, and vinylsiloxane branched chain: 5 parts.

[0174] Comparative Example 1

[0175] This comparative example is modified from the one disclosed in Example 1 as follows:

[0176] Powder coatings consist of an intermediate layer and a top layer, meaning they lack an undercoat.

[0177] Comparative Example 2

[0178] This comparative example is modified from the one disclosed in Example 1 as follows:

[0179] Powder coatings consist of a base coat and a top coat, meaning that an intermediate coat is missing.

[0180] Comparative Example 3

[0181] This comparative example is modified from the one disclosed in Example 1 as follows:

[0182] Powder coatings consist of a base coat and an intermediate coat, meaning they lack a top coat.

[0183] Comparative Example 4

[0184] This comparative example is modified from the one disclosed in Example 1 as follows:

[0185] The base coat is composed of the following chemical components: 32 parts of organosilicon-epoxy binary hybrid resin, 12 parts of boron nitride, 5 parts of KH-550 modified silicon carbide, and Al2O3@SiO2 core-shell particles.

[0186] Comparative Example 5

[0187] This comparative example is modified from the one disclosed in Example 1 as follows:

[0188] Boron nitride is not added to the base coat.

[0189] Comparative Example 6

[0190] This comparative example is modified from the one disclosed in Example 1 as follows:

[0191] Al2O3@SiO2 core-shell particles are not added to the base coating.

[0192] Comparative Example 7

[0193] This comparative example is modified from the one disclosed in Example 1 as follows:

[0194] Zr-Ti-V composite oxides are not added to the intermediate coating.

[0195] Comparative Example 8

[0196] This comparative example is modified from the one disclosed in Example 1 as follows:

[0197] No silica aerogel is added to the topcoat.

[0198] The high-temperature resistant coatings obtained in Examples 1-4 and Comparative Examples 1-8 were subjected to performance tests. The specific test methods are shown in Table 1, and the performance results are shown in Tables 2 and 3.

[0199] Table 1. Methods for determining the performance of high-temperature resistant coatings

[0200]

[0201] Table 2 Performance of the high-temperature resistant coatings in Examples 1-4

[0202]

[0203]

[0204] As shown in Table 2, the high-temperature resistant coatings obtained in Examples 1-4 have the following properties: axial thermal conductivity of 45-55 W / (m·K) due to the directional arrangement of BN in the bottom layer and the rigid framework of the ternary hybrid resin; radial thermal conductivity of 0.025-0.035 W / (m·K) due to the thermal insulation of the surface layer aerogel pores and the dispersion of nanofillers in the middle layer; adhesion of 3B-4B (cross-cut test) due to the high adhesion of the bottom layer resin and the interfacial bonding of the middle layer hyperbranched resin; and "hard-soft" composite of the bottom layer KH-550 modified silicon carbide + Al2O3@SiO2 core-shell particles. The wear resistance is 3-8 mg loss (Taber wear); due to the APP / ZB composite surface layer and the Zr-Ti-V oxide catalytic carbonization of the intermediate layer, the flame retardancy is UL-94V-0 to V-1 level, with an LOI of 35-42%; due to the stress buffering of nano-kaolinite / talc powder in the intermediate layer and the plastic deformation of the core-shell particles in the bottom layer, the thermal shock resistance is 6-10 cycles without cracking; due to the Zr-Ti-V phase transformation toughening of the intermediate layer and the endothermic decomposition of hyperbranched resin siloxane, the high-temperature oxidation stability is 0.3-1.2% weight loss at 1000℃ / 10h.

[0205] Table 3 shows the performance of the high-temperature resistant coatings in Comparative Examples 1–8.

[0206]

[0207]

[0208] As shown in Table 3, Comparative Example 1 lacked a substrate, which resulted in a decrease in axial thermal conductivity (due to the absence of the BN directional thermal conduction network). The substrate is the adhesive layer between the substrate and the coating; its absence reduces adhesion. Without a substrate to buffer thermal stress, cracking occurred after only two cycles.

[0209] In Comparative Example 2, the absence of an intermediate layer led to a mismatch in the coefficient of thermal expansion, resulting in cracking after five thermal shock cycles. The lack of a synergistic flame-retardant effect between the intermediate Zr-Ti-V oxide and APP / ZB layers also reduced the LOI (Liquidity Index).

[0210] In Comparative Example 3, the absence of a surface layer and the lack of aerogel led to an increase in radial thermal conductivity. The absence of the APP / ZB surface layer resulted in a decrease in LOI.

[0211] In Comparative Example 4, a binary resin was used. When the ternary hybrid resin was replaced with a binary resin (without PAES), the high-temperature rigidity was insufficient and the wear resistance decreased. The absence of the aromatic ring structure in PAES led to an increase in oxidative weight loss.

[0212] In Comparative Example 5, no BN was present, leading to a decrease in axial thermal conductivity. The wear-resistant properties of the BN layered structure were also lost, resulting in increased wear.

[0213] In Comparative Example 6, the absence of core-shell particles and Al2O3@SiO2 resulted in reduced thermal stress buffering capacity, leading to cracking after 6 thermal shock cycles. The lack of the SiO2 shell also reduced corrosion resistance.

[0214] In Comparative Example 7, Zr-Ti-V was absent, resulting in the loss of Zr-Ti-V phase transformation toughening and increased oxidation weight loss. The synergistic flame retardancy between Zr-Ti-V and APP failed, leading to a decrease in LOI.

[0215] In Comparative Example 8, without aerogel, the radial thermal conductivity increased, and the substrate temperature rose significantly. The oxygen barrier effect of the aerogel pores was lost, resulting in a decrease in LOI (Lower Optical Index).

[0216] Various embodiments of this application may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a hard limitation on the scope of this application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Furthermore, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the referred range.

[0217] Furthermore, in the description of this application, the terms "comprising," "including," etc., mean "including but not limited to." In this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. In this document, "and / or" describes the relationship between related objects, indicating that three relationships can exist; for example, A and / or B can represent: A alone, A and B simultaneously, or B alone. A and B can be singular or plural. In this document, "at least one" means one or more, and "more than" means two or more. "At least one," "at least one of the following," or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, "at least one of a, b, or c" or "at least one of a, b, and c" can both represent: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple. "Parts representation," such as parts by weight or parts by mass, indicates the proportional relationship between components. In the proportional relationships discussed in this article, parameters described by proportion should be understood as the first term of the proportion in the order of description, while the proportion figure should be understood as the second term. For example, if the mass ratio of substance A, substance B, and substance C is 1:2:3, then substances A, B, and C should correspond one-to-one with the proportion figure in the proportion in the order of description, i.e., the mass of substance A : the mass of substance B : the mass of substance C = 1:2:3.

[0218] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A powder coating with excellent high-temperature resistance, characterized in that, The powder coating is composed of a base coating, an intermediate coating and a top coating; wherein, in terms of mass parts, The base coating is composed of the following chemical components: 20-40 parts of a silicone-epoxy-polyarylether sulfone ternary hybrid resin, 5-15 parts of boron nitride, 2-6 parts of KH-550 modified silicon carbide, and 3-8 parts of Al2O3@SiO2 core-shell particles; The intermediate coating is composed of the following chemical components: 10-20 parts of a polyimide-siloxane hyperbranched resin, 3-6 parts of Zr-Ti-V composite oxides, and 1-4 parts of a nano-kaolinite / talcum powder compound; The top coating is composed of the following chemical components: 10-20 parts of a silicone-epoxy-polyarylether sulfone ternary hybrid resin, 5-15 parts of silica aerogel, and 1-3 parts of a polyammonium phosphate / zinc borate compound; The preparation method of the silicone-epoxy-polyarylether sulfone ternary hybrid resin comprises the following steps: A first mixed solution is obtained by adding polymethylphenylsiloxane, bisphenol A type epoxy resin and fluorine-containing end group polyarylether sulfone into an organic solvent in a proper proportion; The pH value of the first mixed solution is adjusted to 3-4, and a stirring reaction is performed to form a sol-gel interpenetrating network, thereby obtaining a second mixed solution; A titanium ester catalyst is added to the second mixed solution, and the temperature is raised to 120 DEG C for 2h of reaction, thereby obtaining the silicone-epoxy-polyarylether sulfone ternary hybrid resin; The preparation method of the polyimide-siloxane hyperbranched resin comprises the following steps: A third mixed solution is obtained by adding a polyimide prepolymer, a hydroxyl-terminated polydimethylsiloxane and a titanium ester catalyst into an organic solvent for 8h of condensation reaction at 120 DEG C; Vinyl siloxane branches are added to the third mixed solution, and the temperature is raised to 80 DEG C for 4h of reaction, so that the siloxane is hydrolyzed and condensed to form branching points, thereby obtaining a fourth mixed solution; A benzocyclobutene crosslinking agent and a free radical initiator are added to the fourth mixed solution, and the temperature is then raised to 140 DEG C for 6h of reaction under nitrogen protection, so that the cyclic structure of the benzocyclobutene crosslinking agent is opened and crosslinked with the vinyl siloxane branches, thereby obtaining a fifth mixed solution; The fifth mixed solution is subjected to post-treatment and purification, thereby obtaining the polyimide-siloxane hyperbranched resin; The preparation method of the Zr-Ti-V composite oxides comprises the following steps: A zirconium nitrate solution, a tetrabutyl titanate solution and an ammonium metavanadate solution are mixed, and ammonia water is slowly added to adjust the pH value to 8.8-9.2, so that a coprecipitation reaction is performed to form a precipitate; the coprecipitation reaction is performed at room temperature for 12-24h; The precipitate is calcined, thereby obtaining a Zr-Ti-V composite oxide sintered block; the calcination is performed at a temperature of 1100-1300 DEG C for 3-5h; The Zr-Ti-V composite oxide sintered block is subjected to high-energy ball milling, thereby obtaining the Zr-Ti-V composite oxides.

2. The powder coating having high temperature resistance according to claim 1, characterized in that, In the nano-kaolinite / talcum powder compound, the mass ratio of nano-kaolinite to talcum powder is 1:1-3:1; In the polyammonium phosphate / zinc borate compound, the mass ratio of polyammonium phosphate to zinc borate is 2:1-3:1; The Zr-Ti-V composite oxide is a bimodal nanoparticle composed of large particles of 50-100 nm and small particles of 5-20 nm.

3. The powder coating having high temperature resistance according to claim 1, characterized in that, The silicone-epoxy-polyarylether sulfone ternary hybrid resin comprises, in parts by mass, polyphenylmethylsiloxane 50-65, bisphenol A type epoxy resin 20-30, and fluorine-containing end group polyarylether sulfone 10-20. The polyimide-silicone hyperbranched resin comprises, in parts by mass, polyimide prepolymer 50-80, benzocyclobutene crosslinking agent 12-20, hydroxyl-terminated polydimethylsiloxane 20-35, and vinyl siloxane branch 5-15.

4. A method for producing a powder coating having excellent high-temperature resistance, for producing the powder coating having excellent high-temperature resistance according to any one of claims 1 to 3, characterized by, The method comprises: The bottom layer coating is obtained by mixing the silicone-epoxy-polyarylether sulfone ternary hybrid resin, boron nitride, KH-550 modified silicon carbide, and Al2O3@SiO2 core-shell particles. The intermediate layer coating is obtained by mixing the polyimide-silicone hyperbranched resin, Zr-Ti-V composite oxide, and nano-kaolinite / talcum powder compound. The top layer coating is obtained by mixing the silicone-epoxy-polyarylether sulfone ternary hybrid resin, silica aerogel, and ammonium polyphosphate / zinc borate compound.

5. The method of claim 4, wherein the powder coating having high temperature resistance is prepared by mixing the base powder, the curing agent, and the curing catalyst. The preparation method of the Al2O3@SiO2 core-shell particle comprises: The hydroxylated Al2O3 is dispersed in a KH-550 ethanol solution, stirred at 60℃ for 4 hours to bond silane to the surface of Al2O3, and modified Al2O3 is obtained. Tetraethyl orthosilicate is added to the ethanol / water mixed solution of modified Al2O3, ammonia water is slowly added to adjust the pH value to 9-10, and the solution is stirred at 50℃ for 6 hours to hydrolyze the tetraethyl orthosilicate to generate SiO2 and deposit on the surface of Al2O3, and the coating is obtained by centrifugation. The coating is calcined at high temperature to obtain the Al2O3@SiO2 core-shell particle; the high-temperature calcination temperature is 550-650℃, and the time is 1.5-2.5h.

6. A high temperature resistant coating, characterized in that, The high-temperature-resistant coating is formed by spraying and curing the high-temperature-resistant powder coating with good high-temperature-resistant performance according to any one of claims 1-3, in the high-temperature-resistant coating, the boron nitride is directionally arranged along the heat flow direction by a magnetic field, and forms an anisotropic heat-conducting and heat-insulating network with the silica aerogel.

7. A method for the production of a high-temperature-resistant coating for the production of a high-temperature-resistant coating according to claim 6, characterized in that The method comprises: The bottom layer coating is sprayed onto the surface of the substrate, and a transverse magnetic field is applied parallel to the surface of the substrate to directionally arrange the boron nitride sheets along the heat flow direction to form a bottom layer; The intermediate layer coating is sprayed onto the surface of the bottom layer to form an intermediate layer; The top layer coating is vertically sprayed onto the surface of the intermediate layer to form an axial heat-conducting and radial heat-insulating network, and then cured to obtain the high-temperature-resistant coating.

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