High-temperature-resistant heat-insulating ceramicizable fireproof sealing glue and preparation method thereof

Abstract

This invention discloses a high-temperature resistant, heat-insulating, ceramizable fire-resistant sealing adhesive and its preparation method. The fire-resistant sealing adhesive comprises the following raw materials: base adhesive, dimethyl silicone oil, flame retardant, composite ceramic powder, additive filler, flux, silane coupling agent, crosslinking agent, functional filler, and catalyst. The functional filler is composed of fumed silica, high-temperature resistant aerogel powder, and silicon carbide powder, with a mass ratio of 40-50:20-30:20-30. Through the specific selection of multi-stage filler compounding, this invention achieves a balance between room-temperature performance and the high-temperature ceramization process that is unattainable in existing technologies. Its flame retardant rating can reach V0, its fire resistance limit is greater than 4.5 hours, and during the burning process, the highest temperature on the unexposed surface does not exceed 110°C.

Description

Technical Field

[0001] This invention relates to the field of organosilicon elastomer fireproof sealing materials, and in particular to a high-temperature resistant, heat-insulating, ceramicizable fireproof sealing adhesive and its preparation method. Background Technology

[0002] Fire-resistant sealing materials are a key component in ensuring building fire safety. They are mainly used to seal openings and gaps formed when cables, oil pipes, air ducts, natural gas pipes, etc. pass through floors and walls in industrial and civil buildings, structures, and facilities, as well as to provide fire-resistant partitions for cable trays. They can effectively prevent the spread of flames, hot air currents, and toxic fumes through these openings and gaps.

[0003] Organosilicon elastomer fire-retardant sealants hold an important position in the fire-sealing field due to their dual functions of sealing and fireproofing, as well as their advantages such as high elasticity, good waterproof and airtight properties, and convenient construction. In practical engineering, flame-retardant sealants often achieve their flame-retardant effect by filling ordinary sealants with large amounts of flame retardants (such as aluminum hydroxide, calcium carbonate, melamine, etc.). While these flame retardants can impart a certain degree of self-extinguishing ability to the material after the flame is removed, the organic matrix will gradually decompose in a sustained flame environment, eventually collapsing and completely losing its sealing function. Furthermore, these flame retardants offer limited improvement to the material's fire resistance, cannot significantly improve the integrity and strength of the char residue after combustion, and have poor compatibility with the base adhesive; excessive addition can impair the mechanical properties at room temperature.

[0004] To overcome the aforementioned shortcomings, ceramizable fire-resistant sealants have become a research hotspot in recent years. By introducing ceramic powder into silicone sealants, they are sintered at high temperatures to form a self-supporting ceramic body, thus maintaining structural integrity during a fire. However, this technical approach still faces challenges: First, the removal of small molecules from the silicone sealant at high temperatures leads to volume shrinkage and the formation of pores, compromising density and the strength of the ceramic body; second, achieving ceramization requires the addition of large amounts of inorganic fillers such as wollastonite and mica, resulting in increased viscosity and decreased flowability, affecting application performance; third, while the use of modified whiskers and organopolysilazanes can improve the effect, their high cost limits their application to high-end scenarios and hinders widespread adoption.

[0005] In summary, significantly improving the mechanical strength and thermal insulation performance of ceramic bodies after high-temperature sintering, while ensuring the bonding strength, elasticity, and mechanical properties of materials at room temperature, remains a pressing technical challenge in this field. Most existing solutions often compromise on one aspect while neglecting another, resulting in insufficient ceramic body strength or the material becoming hard and brittle at room temperature, making it difficult to simultaneously meet the long-term performance requirements under complex working conditions and the protection requirements under extreme fire conditions. Summary of the Invention

[0006] To address the challenges in balancing room-temperature mechanical properties and high-temperature ceramization properties in existing fire-resistant sealing adhesives, which often result in low strength and structural collapse of the high-temperature ceramic body, this invention provides a high-temperature resistant, heat-insulating, and ceramizable fire-resistant sealing adhesive and its preparation method. This material maintains excellent elasticity and adhesion at room temperature and rapidly forms a high-strength, heat-insulating, and structurally intact ceramic body upon contact with fire, effectively preventing the spread of flames.

[0007] In a first aspect, the present invention provides a high-temperature resistant, heat-insulating, ceramicizable fireproof sealing adhesive, which is achieved through the following technical solution.

[0008] A high-temperature resistant, heat-insulating, ceramizable fireproof sealing adhesive comprises the following raw materials in parts by weight: 100 parts base adhesive, 5-15 parts dimethyl silicone oil, 15-25 parts flame retardant, 10-20 parts composite ceramic powder, 60-100 parts additive filler, 0.5-5 parts flux, 1-2 parts silane coupling agent, 5-15 parts crosslinking agent, 2-6 parts functional filler, and 0.1-0.3 parts catalyst;

[0009] The functional filler is composed of fumed silica, high-temperature resistant aerogel powder and silicon carbide powder, and the mass ratio of the three is 40~50:20~30:20~30; the high-temperature resistant aerogel powder is an alumina-silica or zirconium oxide-silica composite aerogel with a particle size of 2~50μm.

[0010] The reaction principle of this invention is as follows: The ceramization process is the gradual hardening of materials at high temperatures to form a ceramic body with a certain strength, involving both physical bonding and chemical reactions. The physical bonding process involves the flux melting to form a liquid phase as the temperature rises, which bonds the ceramic filler and the solid products of polymer decomposition, forming a relatively complete ceramic structure. The chemical reaction process, taking a composite material of kaolin, wollastonite, and quartz powder / zinc borate / silicone rubber as an example, has the following eutectic reaction mechanism:

[0011] Decomposition of zinc borate:

[0012] 2ZnO·3B2O3·3.5H2O→2ZnO+3B2O3+3.5H2O↑ at 370 ~ 500 ℃

[0013] Transformation of silicon dioxide:

[0014] At 1000 ℃, SiO2 (amorphous) → SiO2 (crystalline).

[0015] Decomposition of ceramic fillers:

[0016] At 600 ~ 950 ℃, Al2O3·2SiO2·2H2O (kaolin) → Al2O3·2SiO2+2H2O↑

[0017] Al₂O₃·2SiO₂→Al₂O₃+2SiO₂ at 950 ~ 1050 ℃

[0018] Eutectic reaction:

[0019] 2SiO2 + 3Al2O3 → Al6Si2O 13 (Mollite)

[0020] CaO + 2SiO2 + Al2O3 → CaAl2Si2O8 (calcium feldspar)

[0021] ZnO + Al₂O₃ → ZnAl₂O₄ (Zinc Aluminum Spinel)

[0022] At room temperature, the ceramic powder is tightly encapsulated by the fire-retardant sealant system, with almost no impact on tensile and adhesive properties. As the temperature rises, the ceramic powder absorbs heat to form a dense protective film that isolates oxygen, achieving a flame-retardant effect. Simultaneously, the ceramic-forming components in the ceramic powder work synergistically with the flame retardant, causing the fire-retardant sealant to sinter and form a ceramicized structure with a certain strength during high-temperature calcination. Before calcination, the ceramic powder is tightly encapsulated by the polysiloxane polymer, resulting in an almost completely homogeneous cross-sectional structure. After calcination, the polysiloxane decomposes and diffuses, causing a phase transition in the ceramic powder, forming a dense ceramicized structure.

[0023] Most existing flame-retardant silicone fire-resistant sealants comply with the GB / T 24267-2009 standard, "Flame-retardant sealants for building applications." This standard only assesses the self-extinguishing performance of materials after flame exposure and does not address the fire integrity and heat insulation properties that are crucial considerations in actual fire conditions. Flame-retardant sealants that pass this standard test are not easily combustible in a sustained flame environment, but they are prone to rapid ablation and pulverization after exposure to a large fire, losing strength and collapsing rapidly under vibration or pressure, leading to secondary flame spread. This application introduces ceramizable components into organic fire-resistant sealant materials. Upon exposure to fire, the internal ceramizable filler rapidly ceramizes, and the ablated material forms a ceramic body with a certain mechanical strength, effectively preventing secondary flame spread. Its flame retardant rating can reach V0, with a fire resistance limit greater than 4.5 hours, and the highest temperature on the unexposed surface does not exceed 110℃ during burning. In addition, the incremental filler in this application is a compound of wollastonite and nano-calcium carbonate, and the functional filler is preferably a compound of fumed silica, high-temperature resistant aerogel powder and silicon carbide powder, thus obtaining a fireproof sealing adhesive with excellent fire resistance, thermal insulation and mechanical properties.

[0024] Furthermore, the base adhesive is α,ω-dihydroxypolydimethylsiloxane, the viscosity of the base adhesive at 25 °C is 20000 ~ 80000 mPa·s, and its solid content is ≥98%.

[0025] By adopting the above technical solution, the α,ω-dihydroxy polydimethylsiloxane (107 glue) molecular chain has active hydroxyl groups at both ends. During crosslinking, it reacts with the crosslinking agent to form a network structure, thus forming a three-dimensional network elastomer. In addition, this invention strictly controls the molecular weight of the base glue. If the molecular weight is too high, the fireproof sealing glue has high viscosity, poor flowability, is difficult to process, and is inconvenient to use; if the molecular weight is too low, the mechanical properties are poor.

[0026] Furthermore, the dimethyl silicone oil has a viscosity of 200-500 mPa·s at 25 °C and a molecular formula of (CH3)3SiO[Si(CH3)2O]. n Si(CH3)3, n=30~160.

[0027] By adopting the above technical solution, the present invention uses dimethyl silicone oil as a diluent for high-viscosity base polymers, which can effectively reduce the viscosity of the adhesive, making it easier to mix and degas, improve the extrusion performance during construction, and enhance the flexibility and elasticity of the cured adhesive; its decomposition at high temperature to form silica residue helps to form a ceramic thermal insulation barrier.

[0028] Furthermore, the flame retardant is composed of melamine polyphosphate and dipentaerythritol, with a mass ratio of 50-80:10-30. The combination of these two components forms a highly efficient intumescent flame retardant system, which generates a dense, porous char layer upon heating, providing heat insulation, oxygen barrier, and smoke suppression.

[0029] Furthermore, the composite ceramic powder is composed of wollastonite, quartz, and kaolin in a mass ratio of 35~45:35~40:5~10; the wollastonite has a particle size of 800~4000 mesh, a needle-like morphology, and an aspect ratio of 15~20:1; the quartz has a particle size of 1250~15000 mesh; and the kaolin has a particle size of 1250~15000 mesh.

[0030] By adopting the above technical solution, the composite ceramic powder can generate mullite, calcium feldspar and other crystalline phases at high temperature. The three phases work together to form a ceramic structure, which serves as a supporting skeleton after the fireproof sealing adhesive decomposes, and continues to play a fireproof sealing role, ensuring that the fire resistance limit is greater than 4.5h.

[0031] Furthermore, the incremental filler uses wollastonite and nano-calcium carbonate in a mass ratio of 30~80:20~50.

[0032] Furthermore, the flux is selected from at least one of zinc borate and boron oxide. The flux has a very low melting point and melts at high temperatures to form a liquid phase, initiating and promoting the ceramization process.

[0033] Furthermore, the silane coupling agent is selected from one or more of γ-(methacryloyloxy)propyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and 3-aminopropyltriethoxysilane. The silane coupling agent participates in the formation of a three-dimensional siloxane network structure through hydrolysis and condensation reactions, becoming part of the cured colloid and bridging the interface between the organic phase and the inorganic substrate, significantly enhancing adhesion strength and durability.

[0034] Furthermore, the crosslinking agent is selected from at least one of methyltributanone oxime silane and vinyltributanone oxime silane.

[0035] Furthermore, the catalyst is dibutyltin dilaurate.

[0036] Furthermore, the fumed silica is hydrophobic and has a specific surface area of ​​50 to 400 m² / g.

[0037] Furthermore, the silicon carbide powder is α-SiC crystal form, with a purity ≥99% and a particle size of 1~10μm. Moreover, the silicon carbide powder does not react with other components in the system at high temperatures, which can suppress radiative heat transfer to improve thermal insulation performance and serve as an inert skeleton to improve the structural integrity of the ceramic body.

[0038] By adopting the above technical solution, the compressive strength of the ceramic body formed by the fireproof sealing adhesive of the present invention after being burned at 1000 ℃ is ≥0.5 MPa.

[0039] Secondly, the present invention provides a method for preparing a high-temperature resistant, heat-insulating, ceramicizable fireproof sealing adhesive, which is achieved through the following technical solution.

[0040] A method for preparing the above-mentioned high-temperature resistant, heat-insulating, ceramicizable fireproof sealing adhesive includes the following steps:

[0041] S1. Mix the base adhesive, dimethyl silicone oil, flame retardant, and flux, and disperse for 15 to 40 minutes at a stirring speed of 20-40 rpm and a dispersion speed of 2000-3500 rpm to obtain system I;

[0042] S2. Nano-calcium carbonate is compounded with wollastonite to obtain an incremental filler;

[0043] S3. Wollastonite, quartz and kaolin are compounded to obtain composite ceramic powder;

[0044] S4. Mix fumed silica, high-temperature resistant aerogel powder and silicon carbide powder in a high-speed mixer for 10 to 30 minutes to fully disperse the three components and obtain a premixed functional filler.

[0045] S5. Add incremental filler and composite ceramic powder to system I, and stir to dehydrate and disperse under heating at 110 ℃ ~ 120 ℃ and vacuum conditions. The stirring speed is 20 - 40 rpm, the dispersion speed is 2000 - 3500 rpm, and the stirring and dispersion time is 120 ~ 180 min. Cool to below 40 ℃ to obtain system II.

[0046] S6. Add crosslinking agent and functional filler to system II, mix evenly under vacuum to obtain system III;

[0047] S7. Add silane coupling agent and catalyst to system III, mix evenly under vacuum conditions to obtain the fireproof sealing adhesive.

[0048] Furthermore, in steps S1, S5, S6, and S7, the vacuum degree is -0.08 ~ -0.1 MPa.

[0049] This application has the following beneficial effects.

[0050] The fire-resistant sealing adhesive of this application achieves a balance between room-temperature performance and high-temperature ceramization through the specific selection of multi-level filler compounding, a balance unmatched by existing technologies. Fumed silica significantly improves the fluidity and thixotropy of the adhesive; high-temperature resistant aerogel powder provides superior thermal insulation; silicon carbide does not decompose or undergo phase change at high temperatures, effectively suppressing radiative heat transfer and significantly enhancing the strength and structural integrity of the ceramic body as an inert framework. The synergistic effect of these three components results in excellent mechanical properties at room temperature and higher strength and better thermal insulation in the ceramic body formed at high temperatures. The ceramization of the adhesive is achieved through the physical gradation of inorganic fillers and a high-temperature eutectic reaction, offering advantages such as lower cost and simpler processing. Its flame retardant rating reaches V0, its fire resistance limit is greater than 4.5 hours, and the maximum temperature on the unexposed surface does not exceed 110°C during burning. It is applicable to the openings and gaps formed when cables, oil pipes, air ducts, natural gas pipes, etc. pass through floors and walls in industrial and civil buildings, as well as the segmented fireproof separation of cable bridges, to prevent the spread of flames, hot air currents and toxic fumes through these openings and gaps, and to enhance structural safety. Detailed Implementation

[0051] The invention will be further described below with reference to the embodiments. Unless otherwise specified, the experimental methods used in the embodiments of the present invention are conventional methods, and the materials and reagents used are commercially available unless otherwise specified.

[0052] The α,ω-dihydroxy polydimethylsiloxane used in the following embodiments of the present invention was purchased from Dow Corning 107 glue OHX.

[0053] The melamine polyphosphate used in the following embodiments of the present invention was purchased from Aladdin.

[0054] The high-temperature resistant aerogel powder used in the following embodiments of the present invention was purchased from GreenAo KNF-W.

[0055] Example 1

[0056] A method for preparing a high-temperature resistant, heat-insulating, ceramicizable fireproof sealing adhesive, comprising the following steps:

[0057] Step 1: Mix 500g of α,ω-dihydroxypolydimethylsiloxane (viscosity 80000 mPa·s), 50g of dimethyl silicone oil (viscosity 350 mPa·s), 75g of melamine polyphosphate, 25g of dipentaerythritol, and 10g of zinc borate. Turn on the stirring and dispersing device, with a stirring speed of 30 rpm, a dispersing speed of 3000 rpm, a stirring and dispersing time of 30 min, a heating temperature of 120 ℃, and a vacuum degree of -0.08 MPa to obtain System I;

[0058] Step 2: Add 160g of nano-calcium carbonate (D50 of 70 nm, specific surface area of ​​20 m²) 2 / g) and 240g of wollastonite (particle size of 1250 mesh) were compounded to obtain the incremental filler;

[0059] Step 3: Combine 39g of wollastonite (1250 mesh), 30.15g of quartz (8000 mesh), and 5.85g of kaolin (8000 mesh) to obtain composite ceramic powder;

[0060] Step 4: Add 10g of fumed silica (specific surface area 400m²) 2 The mixture of 5g of high-temperature resistant aerogel powder (particle size 2-50μm) and 5g of silicon carbide powder (1-10μm) is premixed in a high-speed mixer for 30 min to ensure full dispersion of the three components and obtain a premixed functional filler.

[0061] Step 5: Add incremental filler and composite ceramic powder to system I, dehydrate and disperse under heating and vacuum conditions, and obtain the system after cooling. The heating temperature is 120 ℃, the vacuum degree is -0.08 MPa, the stirring speed is 30 rpm, the dispersion speed is 3000 rpm, the stirring and dispersion time is 150 min, and the cooling temperature is ≤40 ℃.

[0062] Step 6: Add 31.25g of methyl tributanone oxime silane and 18.75g of vinyl tributanone oxime silane and functional filler to system II, and mix them evenly under vacuum (vacuum degree of -0.08 MPa) to obtain system III;

[0063] Step 7: Add 6g of γ-glycidyl oxypropyltrimethoxysilane and 0.5g of dibutyltin dilaurate to system III, mix thoroughly under vacuum conditions, and the vacuum degree is -0.08 MPa.

[0064] Example 2

[0065] A method for preparing a high-temperature resistant, heat-insulating, ceramicizable fireproof sealing adhesive, comprising the following steps:

[0066] Step 1: Mix 400g of α,ω-dihydroxypolydimethylsiloxane (viscosity 80000 mPa·s), 40g of dimethyl silicone oil (viscosity 350 mPa·s), 60g of melamine polyphosphate, 20g of dipentaerythritol, and 10g of zinc borate. Turn on the stirring and dispersing device, with a stirring speed of 30 rpm, a dispersing speed of 3000 rpm, a stirring and dispersing time of 30 min, a heating temperature of 120 ℃, and a vacuum degree of -0.08 MPa to obtain System I;

[0067] Step 2: Add 106.6g of nano-calcium carbonate (D50 of 70 nm, specific surface area of ​​20 m²) 2 / g) and 213.4g of wollastonite (particle size of 800 mesh) were compounded to obtain the incremental filler;

[0068] Step 3: Combine 31.2g of wollastonite (1250 mesh), 24.12g of quartz (1250 mesh), and 4.68g of kaolin (1250 mesh) to obtain composite ceramic powder;

[0069] Step 4: Add 8g of fumed silica (specific surface area 400m²) 2 The premixed functional filler is prepared by mixing 4g of high-temperature resistant aerogel powder (particle size 2-50μm) and 4g of silicon carbide powder (1-10μm) in a high-speed mixer for 30 min.

[0070] Step 5: Add incremental filler and composite ceramic powder to system I, dehydrate and disperse under heating and vacuum conditions, and obtain the system after cooling. The heating temperature is 120 ℃, the vacuum degree is -0.08 MPa, the stirring speed is 30 rpm, the dispersion speed is 3000 rpm, the stirring and dispersion time is 150 min, and the cooling temperature is ≤40 ℃.

[0071] Step 6: Add 31.25g of methyl tributanone oxime silane and 18.75g of vinyl tributanone oxime silane and functional filler to system II, and mix them evenly under vacuum (vacuum degree of -0.08 MPa) to obtain system III;

[0072] Step 7: Add 6g of γ-glycidyl oxypropyltrimethoxysilane and 0.5g of dibutyltin dilaurate to system III, mix thoroughly under vacuum conditions, and the vacuum degree is -0.08 MPa.

[0073] Example 3

[0074] A high-temperature resistant, heat-insulating, ceramicizable fireproof sealing adhesive differs from Example 1 in that the preparation process of the composite ceramic powder in step 3 is as follows: 39g of wollastonite (particle size 1250 mesh), 30.15g of quartz (particle size 1250 mesh) and 5.85g of kaolin (particle size 1250 mesh) are compounded.

[0075] Example 4

[0076] A high-temperature resistant, heat-insulating, ceramicizable fireproof sealing adhesive differs from Example 1 in that the preparation process of the composite ceramic powder in step 3 is as follows: 30g of wollastonite (particle size 1250 mesh), 20g of quartz (particle size 1250 mesh) and 5g of kaolin (particle size 1250 mesh) are compounded.

[0077] Example 5

[0078] A high-temperature resistant, heat-insulating, ceramicizable fireproof sealing adhesive differs from Example 1 in that the amount of melamine polyphosphate and dipentaerythritol added in step 1 is 50g each.

[0079] Comparative Example 1

[0080] A fire-resistant sealing adhesive, differing from Example 1 in that the preparation process of the functional filler in step 4 is as follows: 10g of fumed silica (with a specific surface area of ​​400m²) is added... 2 5g of high-temperature resistant aerogel powder (particle size 2-50μm) were pre-dry-mixed in a high-speed mixer for 30 min to ensure full dispersion.

[0081] Comparative Example 2

[0082] A fire-resistant sealing adhesive, differing from Example 1 in that the preparation process of the functional filler in step 4 is as follows: 10g of fumed silica (with a specific surface area of ​​400m²) is added... 2 5g of silicon carbide powder (1-10μm) was pre-dry-mixed in a high-speed mixer for 30 min to ensure full dispersion.

[0083] Comparative Example 3

[0084] A fireproof sealing adhesive differs from Example 1 in that the preparation process of the functional filler in step 4 is as follows: 5g of high-temperature resistant aerogel powder (particle size 2-50μm) and 5g of silicon carbide powder (1-10μm) are pre-dry mixed in a high-speed mixer for 30 min to ensure full dispersion.

[0085] Comparative Example 4

[0086] A commercially available fireproof sealing adhesive that can be ceramicized.

[0087] Performance testing

[0088] Performance tests were conducted on the high-temperature resistant, heat-insulating, and ceramic-type fire-resistant sealing adhesives of Examples 1 to 5, and the comparative fire-resistant adhesive samples of Examples 1 to 4. The test standards and test data are shown in Table 1.

[0089] Table 1 Performance Test Data

[0090]

[0091] As shown in Table 1, the functional filler of this application uses a specified ratio of fumed silica, high-temperature resistant aerogel powder and silicon carbide powder, and is supplemented with nano-calcium carbonate and wollastonite as incremental fillers. This effectively balances the density, mechanical properties and fire resistance of the fireproof sealing adhesive, resulting in a tensile strength ≥1.0 MPa at room temperature and a compressive strength of ≥0.5 MPa in the ceramic body after ignition. This achieves a balance between room temperature mechanical properties and high-temperature ceramic fireproofing performance.

[0092] Based on comparative examples 1 to 4 and the data comparison table, it can be seen that this application uses a compound of fumed silica, high-temperature resistant aerogel powder and silicon carbide powder in a specified ratio. Fumed silica is used to provide room temperature reinforcement and thixotropy, high-temperature resistant aerogel powder is used to provide high-temperature insulation, and silicon carbide powder is used to improve the structural integrity of the ceramic body. After synergy, it can effectively improve the strength of the ceramic body of the fireproof sealing adhesive after high-temperature burning, increase the structural stability of the component, and the strength of the ceramic body far exceeds the sum of the strength of any one of the fillers used alone, far exceeding the commercial fireproof sealing adhesive.

[0093] Compared to the existing technology (such as CN113122180A) which discloses a "white carbon black + aluminum-based aerogel + ceramic filler" system, this application introduces high-purity α-SiC silicon carbide powder to replace aluminum-based aerogel or other ceramic fillers, constructing a novel reinforcing system. Silicon carbide powder does not undergo phase transformation or oxidative decomposition at high temperatures and can form a denser and more stable SiC-Si-OC ceramic framework with flux (zinc borate / boron oxide) above 800℃, rather than relying solely on the physical insulation of aerogel or the eutectic reaction of ordinary ceramic fillers. Experiments show that the ceramic body formed by this specific combination after calcination at 1000℃ has a compressive strength of over 0.5 MPa, significantly better than the comparative scheme using other ceramic fillers, while simultaneously maintaining excellent room-temperature mechanical properties.

[0094] The embodiments described herein are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape, and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A high-temperature resistant, heat-insulating, ceramic-compatible fireproof sealing adhesive, characterized in that, The raw materials include the following parts by weight: 100 parts base adhesive, 5-15 parts dimethyl silicone oil, 15-25 parts flame retardant, 10-20 parts composite ceramic powder, 60-100 parts additive filler, 0.5-5 parts flux, 1-2 parts silane coupling agent, 5-15 parts crosslinking agent, 2-6 parts functional filler, and 0.1-0.3 parts catalyst; The functional filler is composed of fumed silica, high-temperature resistant aerogel powder and silicon carbide powder, and the mass ratio of the three is 40~50:20~30:20~30; the high-temperature resistant aerogel powder is an alumina-silica or zirconium oxide-silica composite aerogel with a particle size of 2~50μm.

2. The high-temperature resistant, heat-insulating, ceramic-compatible fireproof sealing adhesive according to claim 1, characterized in that, The base adhesive is α,ω-dihydroxypolydimethylsiloxane, and the viscosity of the base adhesive at 25 °C is 20000 ~ 80000 mPa·s.

3. The high-temperature resistant, heat-insulating, ceramic-compatible fireproof sealing adhesive according to claim 1, characterized in that, The dimethyl silicone oil has a viscosity of 200-500 mPa·s at 25 °C and a molecular formula of (CH3)3SiO[Si(CH3)2O]. n Si(CH3)3, n=30~160.

4. The high-temperature resistant, heat-insulating, ceramic-compatible fireproof sealing adhesive according to claim 1, characterized in that, The flame retardant is composed of melamine polyphosphate and dipentaerythritol, with a mass ratio of 50-80:10-30.

5. The high-temperature resistant, heat-insulating, ceramic-compatible fireproof sealing adhesive according to claim 1, characterized in that, The composite ceramic powder is composed of wollastonite, quartz, and kaolin in a mass ratio of 35-45:35-40:5-10; the wollastonite has a particle size of 800-4000 mesh, a needle-like morphology, and an aspect ratio of 15-20:1; the quartz has a particle size of 1250-15000 mesh; and the kaolin has a particle size of 1250-15000 mesh.

6. The high-temperature resistant, heat-insulating, ceramic-compatible fireproof sealing adhesive according to claim 1, characterized in that, The incremental filler uses wollastonite and nano-calcium carbonate in a mass ratio of 30~80:20~50.

7. The high-temperature resistant, heat-insulating, ceramic-compatible fireproof sealing adhesive according to claim 1, characterized in that, The flux is selected from at least one of zinc borate and boron oxide; the silane coupling agent is selected from one or more of γ-(methacryloyloxy)propyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and 3-aminopropyltriethoxysilane; the crosslinking agent is selected from at least one of methyltributanone oxime silane and vinyltributanone oxime silane; and the catalyst is dibutyltin dilaurate.

8. The high-temperature resistant, heat-insulating, ceramic-compatible fireproof sealing adhesive according to claim 1, characterized in that, The fumed silica is hydrophobic and has a specific surface area of ​​50 to 400 m² / g.

9. The high-temperature resistant, heat-insulating, ceramic-compatible fireproof sealing adhesive according to claim 1, characterized in that, The silicon carbide powder is of α-SiC crystal form, with a purity ≥99% and a particle size of 1 ~ 10 μm.

10. A method for preparing a high-temperature resistant, heat-insulating, ceramizable fireproof sealing adhesive according to any one of claims 1-9, characterized in that: Includes the following steps: S1. Mix the base adhesive, dimethyl silicone oil, flame retardant, and flux, and disperse for 15 to 40 minutes at a stirring speed of 20-40 rpm and a dispersion speed of 2000-3500 rpm to obtain system I; S2. Nano-calcium carbonate is compounded with wollastonite to obtain an incremental filler; S3. Wollastonite, quartz and kaolin are compounded to obtain composite ceramic powder; S4. Mix fumed silica, high-temperature resistant aerogel powder and silicon carbide powder in a high-speed mixer for 10 to 30 minutes to fully disperse the three components and obtain a premixed functional filler. S5. Add incremental filler and composite ceramic powder to system I, and stir to dehydrate and disperse under heating at 110 ℃ ~ 120 ℃ and vacuum conditions. The stirring speed is 20 - 40 rpm, the dispersion speed is 2000 - 3500 rpm, and the stirring and dispersion time is 120 ~ 180 min. Cool to below 40 ℃ to obtain system II. S6. Add crosslinking agent and functional filler to system II, mix evenly under vacuum to obtain system III; S7. Add silane coupling agent and catalyst to system III, mix evenly under vacuum conditions to obtain the fireproof sealing adhesive.

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