Thermal insulation material capable of being vitrified at high temperature and preparation method of thermal insulation material

Abstract

The invention relates to the technical field of heat-insulating materials, and discloses a heat-insulating material capable of being ceramized at high temperature and a preparation method thereof.The heat-insulating material comprises a framework including hafnium carbide and tantalum carbide, and the framework is used for improving the performance of a system after ceramization and improving the ablation performance of the material; the matrix material is ethylene propylene diene monomer which is used as a matrix of the material and provides good processability and flexibility for the material at normal temperature; the reinforcing materials comprise hollow glass beads, fumed silica and aerogel silicon dioxide, and the three reinforcing materials have a synergistic effect, so that the mechanical property of the material is improved by enhancing the interface bonding force and forming a'skeleton effect 'at normal temperature, structural support is provided for the ceramic layer, and formation of the compact ceramic layer is promoted; the nitrile elastomer contains phosphorus, nitrogen and other elements, and is used as a ceramic auxiliary agent and a flame-retardant substance to improve the network structure stability of the material and enhance the normal-temperature mechanical property; and the ceramic additives comprise silicon carbide and zirconium oxide, so that the stability of the material at high temperature is improved, and the ablation resistance of the ceramic layer is enhanced.

Description

Technical Field

[0001] The present invention relates to the technical field of thermal insulation materials, in particular to a thermal insulation material capable of being ceramicized at high temperature and a preparation method thereof. Background Art

[0002] Highly flame-retardant cables are a difficult problem in high-rise buildings. It is very important to ensure the safety and reliability of electricity in the event of a fire. The current measure is that the cable coating can be quickly ceramicized at high temperatures, which can not only protect the cable from further burning but also serve the purpose of insulation. However, there are not many materials on the market that can be ceramicized at lower temperatures and the strength after ceramicization is not high. This invention solves this problem.

[0003] In addition, the inner insulation layer material of the solid rocket engine needs to withstand high temperatures above 3000K, which is difficult for general materials to withstand. The rubber material is carbonized after ablation to form a carbonized layer that can not only withstand high-temperature ablation, but also prevent heat from being further conducted to the bottom layer. However, the carbonized layer usually has low strength after formation and will be blown away with the gas flow. This invention provides a ceramic component in the system as a skeleton, which improves the strength after carbonization, reduces the chance of the carbonized layer being blown away with the gas flow, and improves the material's anti-ablation performance.

[0004] Therefore, the present invention rationally designs the material system, and the components that can be ceramicized in different temperature ranges are different, the melting points of ceramicization are different, and the action mechanisms are also different, thereby effectively improving the performance of the material in the entire temperature range and enhancing the ceramicization ability of the material. Summary of the Invention

[0005] In view of the deficiencies of the prior art, the present invention provides a thermal insulation material capable of high-temperature ceramicization and a preparation method thereof.

[0006] To achieve the above objectives, the present invention provides the following technical solutions: a thermal insulation material capable of high temperature ceramicization, comprising a skeleton: hafnium carbide and tantalum carbide, for improving the performance of the system after ceramicization and improving the ablation performance of the material; Base material: EPDM rubber, as the base material, provides the material with good processing performance and flexibility at room temperature; Reinforcement materials: Hollow glass microspheres, fumed silica, and aerogel silica. The three reinforcing materials work synergistically to improve the material's mechanical properties at room temperature by enhancing interfacial bonding and forming a "skeleton effect." They also participate in the ceramicization process at high temperatures, providing structural support for the ceramic layer and promoting the formation of a dense ceramic layer. This is an important foundation for the material to combine good processing properties with high-temperature thermal insulation and ablation resistance. Nitrile elastomers: Containing elements such as phosphorus and nitrogen, they act as ceramicizing agents and flame retardants, improving the stability of the material network structure, enhancing mechanical properties at room temperature, and providing flame retardancy. Ceramicization additives: Silicon carbide and zirconium oxide, as high-temperature resistant materials, promote the ceramicization of materials, improve the stability of materials at high temperatures, and enhance the anti-ablation performance of the ceramic layer.

[0007] Preferably, the ratio is: 100-120 parts of EPDM rubber, 25-35 parts of hollow glass microspheres, 12-18 parts of fumed silica, 8-12 parts of aerogel silica, 15-30 parts of nitrile elastomer, 5-15 parts of silicon carbide, 3-8 parts of zirconium oxide, 1-5 parts of hafnium carbide and 1-5 parts of tantalum carbide. The final product is obtained through the steps of mixing, melting and vulcanization.

[0008] Preferably, the hafnium carbide and tantalum carbide form a high-temperature resistant ceramic phase skeleton at high temperature; The EPDM rubber, as the matrix of the material, is the basic carrier of the entire material structure, supporting the dispersion and combination of other components; Hollow glass microspheres act as rigid fillers, forming a "skeleton effect" to enhance the mechanical properties of the material; they participate in the ceramicization process and provide structural support for the ceramic layer; Fumed silica acts as a ceramic additive to assist in forming ceramic structures and enhance the ceramicization ability of the material; Aerogel silica enhances the interfacial bonding between the matrix and filler with its nano-scale pore structure, reduces internal defects in the material, and improves mechanical properties at room temperature. It also participates in ceramicization at high temperatures, promoting the formation of a dense ceramic layer. Silicon carbide and zirconium oxide: Promote the initial ceramicization of the material at around 600-800℃, forming a ceramic substance containing nitrogen, phosphorus, and silicon, which is cross-linked with the matrix through chemical bonds. Nitrogen and phosphorus elements help to melt silicon dioxide, preventing oxygen propagation and crack expansion; Ceramizing additives: Work synergistically with fused silica to prevent crack growth and oxygen propagation.

[0009] Preferably, a preparation method of a high-temperature ceramic insulating material includes raw material processing: drying hollow glass microspheres, fumed silica, aerogel silica, silicon carbide, zirconium oxide, hafnium carbide, tantalum carbide and other additives and fillers to remove moisture, drying at a temperature of 80-100°C for 2-4 hours; cutting the phosphorus and nitrogen-containing nitrile elastomer into small pieces for easy mixing.

[0010] Preferably, the process further comprises the following steps: adding EPDM rubber into an internal mixer, and plasticizing for 2-3 minutes at a temperature of 80-100°C and a rotation speed of 40-60 r / min; sequentially adding 30 parts of hollow glass microspheres, fumed silica, and 10 parts of aerogel silica, and continuing to mix for 3-5 minutes; then adding an elastomer containing flame retardants such as phosphorus and nitrogen, silicon carbide, zirconium oxide, hafnium carbide, and tantalum carbide, and mixing for 5-8 minutes to fully and evenly disperse the components to obtain a mixed rubber.

[0011] Preferably, the process further comprises the step of transferring the mixed rubber after internal mixing to an open mill, controlling the roller temperature of the open mill at 50-70° C., adjusting the roller distance to 0.5-1 mm, and performing 16 thin passes to further improve the uniformity and plasticity of the mixed rubber.

[0012] Preferably, vulcanization: the rubber compound after the open mill is cut into suitable sizes and placed in a flat vulcanizer for vulcanization. The vulcanization temperature is 160-180°C, the vulcanization pressure is 10-15 MPa, and the vulcanization time is determined according to the thickness of the product, generally 10-30 minutes, to obtain a high-performance EPDM rubber product.

[0013] Preferably, a step-by-step mixing process is performed through a gradient ceramic design: Step 1: using EPDM rubber as a matrix, adding ceramic additives such as hollow glass microspheres, fumed silica, and aerogel silica to lay the foundation for the basic structure; Step 2: Add nitrile elastomer containing elements such as phosphorus and nitrogen and mix to form a material that can be initially ceramicized at 600-800°C; Step 3: Continue to add silicon carbide and zirconium oxide to mix, so that when the material is at about 1500℃, silicon dioxide will melt first with the help of nitrogen and phosphorus substances, preventing crack expansion and oxygen propagation; Step 4: Add hafnium carbide and tantalum carbide to the mixture based on step 3 to form a high-temperature resistant skeleton to further reduce the ablation rate.

[0014] Preferably, a step-by-step mixing process is used: by controlling the order of adding the components, nitrile elastomers of elements such as nitrogen and phosphorus → silicon carbide, zirconium oxide → hafnium carbide, tantalum carbide, so as to achieve gradient control of the ceramicization process.

[0015] Preferably, the application of a high-temperature ceramic insulating material, when applied to the flame-retardant cable sheath, has a compressive strength of ≥10MPa after ceramicization, and a flame retardant grade reaching UL94V-0; when applied to the thermal insulation layer inside a solid rocket engine, under the conditions of a high-temperature gas flow of 3000K, the linear ablation rate is ≤0.1mm / s, the mass ablation rate is ≤0.05g / s, and a dense ceramic layer can be formed on the surface without obvious holes or cracks.

[0016] Compared with the prior art, the present invention provides a thermal insulation material capable of high-temperature ceramicization and a preparation method thereof, which has the following beneficial effects: 1. This high-temperature ceramicized thermal insulation material and its preparation method have good processing performance and flexibility. It can be quickly ceramicized in a high-temperature environment to form a dense ceramic layer. It has excellent thermal insulation performance and high mechanical strength to meet the use requirements of high-temperature industrial fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1The figures are the mechanical property test results of Example 1 and Comparative Examples 1, 2, 3 and 4 of the present invention.

[0018] Figure 2 These are the ablation performance test results of Example 1 and Comparative Examples 4 and 5 in the present invention. DETAILED DESCRIPTION

[0019] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0020] See also Figure 1-Figure 2 , a high temperature ceramic insulation material, characterized by: including a skeleton: hafnium carbide, tantalum carbide, used to improve the performance of the system after ceramicization and improve the ablation performance of the material; Base material: EPDM rubber, as the base material, provides the material with good processing performance and flexibility at room temperature; Reinforcement materials: Hollow glass microspheres, fumed silica, and aerogel silica. The three reinforcing materials work synergistically to improve the material's mechanical properties at room temperature by enhancing interfacial bonding and forming a "skeleton effect." They also participate in the ceramicization process at high temperatures, providing structural support for the ceramic layer and promoting the formation of a dense ceramic layer. This is an important foundation for the material to combine good processing properties with high-temperature thermal insulation and ablation resistance. Nitrile elastomers: Containing elements such as phosphorus and nitrogen, they act as ceramicizing agents and flame retardants, improving the stability of the material network structure, enhancing mechanical properties at room temperature, and providing flame retardancy. Ceramicization additives: Silicon carbide and zirconium oxide, as high-temperature resistant materials, promote the ceramicization of materials, improve the stability of materials at high temperatures, and enhance the anti-ablation performance of the ceramic layer.

[0021] The mixing ratio is: 100-120 parts of EPDM rubber, 25-35 parts of hollow glass microspheres, 12-18 parts of fumed silica, 8-12 parts of aerogel silica, 15-30 parts of nitrile elastomer, 5-15 parts of silicon carbide, 3-8 parts of zirconium oxide, 1-5 parts of hafnium carbide and 1-5 parts of tantalum carbide. The final product is obtained through the steps of mixing, melting and vulcanization.

[0022] The hafnium carbide and tantalum carbide form a high-temperature resistant ceramic phase skeleton at high temperature; The EPDM rubber, as the matrix of the material, is the basic carrier of the entire material structure, supporting the dispersion and combination of other components; Hollow glass microspheres act as rigid fillers, forming a "skeleton effect" to enhance the mechanical properties of the material; they participate in the ceramicization process and provide structural support for the ceramic layer; Fumed silica acts as a ceramic additive to assist in forming ceramic structures and enhance the ceramicization ability of the material; Aerogel silica enhances the interfacial bonding between the matrix and filler with its nano-scale pore structure, reduces internal defects in the material, and improves mechanical properties at room temperature. It also participates in ceramicization at high temperatures, promoting the formation of a dense ceramic layer. Silicon carbide and zirconium oxide: Promote the initial ceramicization of the material at around 600-800℃, forming a ceramic substance containing nitrogen, phosphorus, and silicon, which is cross-linked with the matrix through chemical bonds. Nitrogen and phosphorus elements help to melt silicon dioxide, preventing oxygen propagation and crack expansion; Ceramizing additives: Work synergistically with fused silica to prevent crack growth and oxygen propagation.

[0023] A preparation method of a high-temperature ceramic thermal insulation material includes the following steps: drying hollow glass microspheres, fumed silica, aerogel silica, silicon carbide, zirconium oxide, hafnium carbide, tantalum carbide and other additives and fillers to remove moisture at a temperature of 80-100°C for 2-4 hours; and cutting a phosphorus- and nitrogen-containing nitrile elastomer into small pieces for easy mixing.

[0024] The process also includes internal kneading: adding EPDM rubber into an internal mixer, and plasticizing for 2-3 minutes at a temperature of 80-100°C and a rotation speed of 40-60 r / min; sequentially adding 30 parts of hollow glass microspheres, fumed silica, and 10 parts of aerogel silica, and continuing to mix for 3-5 minutes; then adding an elastomer containing flame retardants such as phosphorus and nitrogen, silicon carbide, zirconium oxide, hafnium carbide, and tantalum carbide, and mixing for 5-8 minutes to fully and evenly disperse the components to obtain a rubber mixture.

[0025] The process also includes open mixing: transferring the mixed rubber after internal mixing to an open mixing mill, controlling the roller temperature of the open mixing mill at 50-70°C, adjusting the roller distance at 0.5-1mm, and performing 16 thin passes to further improve the uniformity and plasticity of the mixed rubber.

[0026] Vulcanization: Cut the milled rubber into suitable sizes and place it in a flat vulcanizer for vulcanization. The vulcanization temperature is 160-180°C, the vulcanization pressure is 10-15 MPa, and the vulcanization time is determined by the thickness of the product, generally 10-30 minutes, to obtain high-performance EPDM rubber products.

[0027] A step-by-step mixing process is carried out through a gradient ceramicization design: Step 1: Using EPDM rubber as the matrix, ceramicizing additives such as hollow glass microspheres, fumed silica, and aerogel silica are added to lay the foundation for the basic structure; Step 2: Add nitrile elastomer containing elements such as phosphorus and nitrogen and mix to form a material that can be initially ceramicized at 600-800°C; Step 3: Continue to add silicon carbide and zirconium oxide to mix, so that when the material is at about 1500℃, silicon dioxide will melt first with the help of nitrogen and phosphorus substances, preventing crack expansion and oxygen propagation; Step 4: Add hafnium carbide and tantalum carbide to the mixture based on step 3 to form a high-temperature resistant skeleton to further reduce the ablation rate.

[0028] Step-by-step mixing process: By controlling the order of adding each component, nitrile elastomers of elements such as nitrogen and phosphorus → silicon carbide, zirconium oxide → hafnium carbide, tantalum carbide, gradient control of the ceramicization process is achieved.

[0029] When used in flame-retardant cable coverings, the compressive strength after ceramicization is ≥10MPa, and the flame retardant grade reaches UL94V-0; when used in the thermal insulation layer of solid rocket engines, under the conditions of 3000K high-temperature gas flow, the linear ablation rate is ≤0.1mm / s, the mass ablation rate is ≤0.05g / s, and a dense ceramic layer can be formed on the surface without obvious holes or cracks.

[0030] Example 1 The EPDM rubber described in this embodiment comprises, in parts by weight, 100 parts of EPDM rubber, 30 parts of hollow glass microspheres, 15 parts of fumed silica, 10 parts of aerogel silica, 20 parts of an elastomer containing flame retardants such as phosphorus and nitrogen, 8 parts of silicon carbide, 5 parts of zirconium oxide, 3 parts of hafnium carbide, and 2 parts of tantalum carbide.

[0031] The present invention also provides a rubber section preparation method of the above-mentioned EPDM rubber, which specifically comprises the following steps: Raw material pretreatment: Dry the hollow glass microspheres, fumed silica, aerogel silica, silicon carbide, zirconium oxide, hafnium carbide, and tantalum carbide separately to remove moisture at a drying temperature of 80-100°C for 2-4 hours; cut the elastomer containing flame retardants such as phosphorus and nitrogen into small pieces for subsequent mixing.

[0032] Internal mixing: Add 100 parts of EPDM rubber into an internal mixer and plasticize for 2-3 minutes at a temperature of 80-100°C and a speed of 40-60r / min; add 30 parts of hollow glass microspheres, 15 parts of fumed silica, and 10 parts of aerogel silica in sequence, and continue mixing for 3-5 minutes; then add 20 parts of an elastomer containing flame retardants such as phosphorus and nitrogen, 8 parts of silicon carbide, 5 parts of zirconium oxide, 3 parts of hafnium carbide, and 2 parts of tantalum carbide, and mix for 5-8 minutes to fully and evenly disperse the components to obtain a mixed rubber.

[0033] Open mixing: Transfer the mixed rubber after internal mixing to an open mixing mill. Control the roller temperature of the open mixing mill at 50-70°C, adjust the roller distance to 0.5-1mm, and pass the mill 16 times to further improve the uniformity and plasticity of the mixed rubber.

[0034] Vulcanization: Cut the milled rubber into suitable sizes and place it in a flat vulcanizer for vulcanization. The vulcanization temperature is 160-180°C, the vulcanization pressure is 10-15 MPa, and the vulcanization time is determined by the thickness of the product, generally 10-30 minutes, to obtain high-performance EPDM rubber products.

[0035] Comparative Example 1 This embodiment provides an EPDM rubber material, which is operated with reference to the operation content of Example 1, except that the aerogel silica is removed.

[0036] Comparative Example 2 This embodiment provides an EPDM rubber material, which is operated with reference to the operation contents of Example 1, except that the hollow glass microspheres are reduced to 15 parts, and the other ingredients remain unchanged.

[0037] Comparative Example 3 This embodiment provides an EPDM rubber material, which is operated with reference to the operation contents of Example 1. The difference from Example 1 is that the phosphorus-nitrogen flame retardant elastomer is replaced with 20 parts of ordinary EPDM rubber, and the other ingredients remain unchanged.

[0038] Comparative Example 4 This embodiment provides an EPDM rubber material, which is operated with reference to the operation content of Example 1, but differs from Example 1 in that hafnium carbide and tantalum carbide are removed, while the other components remain unchanged.

[0039] Comparative Example 5 This embodiment provides an EPDM rubber material. The operation content of Example 1 is referred to, but the difference from Example 1 is that the phosphorus-nitrogen-containing flame retardant elastomer is reduced to 10 parts, and 10 parts of ordinary EPDM rubber is added.

[0040] Comparative Example 1 was subjected to mechanical property testing, and the results are shown in Table 1. After removing the aerogel silica, the tensile strength and elongation at break decreased, and the decrease in mechanical properties was gradual, with a small difference. The mechanical property test results of Example 1 were compared with those of Comparative Examples 1, 2, 3, and 4, as shown in Table 1.

[0041] Table 1 As can be seen from the table, the effect of aerogel silica: Comparative Example 1 After removing the aerogel, the tensile strength decreased by about 18.4%, because the nano-scale pore structure of the aerogel can enhance the interfacial bonding between the matrix and the filler. After its removal, the internal defects of the material increase and the load-bearing capacity decreases. The effect of the amount of hollow glass microspheres: Comparative Example 2 After reducing the amount of hollow glass microspheres, the tensile strength decreased by about 21.6%, because hollow microspheres are rigid fillers, and adding an appropriate amount can form a "skeleton effect". When the amount is insufficient, the reinforcement effect is weakened. The effect of flame retardant elastomer: Comparative Example 3 After replacing with ordinary rubber, the tensile strength decreased significantly by 23.2%, because the phosphorus and nitrogen-containing flame retardant elastomer is cross-linked with the matrix through chemical bonds, improving the stability of the network structure. Ordinary rubber has a low cross-linking density and insufficient strength.

[0042] Effect of high-temperature resistant fillers (hafnium carbide and tantalum carbide): After comparative example 4 is removed, the tensile strength decreases by about 12%. This is because hafnium carbide and tantalum carbide can form a ceramic phase skeleton at high temperatures and can also improve mechanical properties at room temperature through particle reinforcement effect.

[0043] Comparative Examples 4 and 5 were subjected to ablation performance tests, and the results are shown in Table 2. The mechanical performance test results of Example 1 and Comparative Examples 4 and 5 were compared and sorted, as shown in Table 2.

[0044]

[0045] When using, While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A thermal insulation material capable of high temperature ceramicization, characterized in that: It includes a skeleton: hafnium carbide and tantalum carbide, which are used to improve the performance of the system after ceramicization and improve the ablation performance of the material; Base material: EPDM rubber, as the base material, provides the material with good processing performance and flexibility at room temperature; Reinforcement materials: Hollow glass microspheres, fumed silica, and aerogel silica. The three reinforcing materials work synergistically to enhance the mechanical properties of the material by strengthening the interfacial bonding and forming a "skeleton effect" at room temperature. They also participate in the ceramicization process at high temperatures, providing structural support for the ceramic layer and promoting the formation of a dense ceramic layer. This is an important foundation for the material to combine good processing properties with high-temperature thermal insulation and ablation resistance. Nitrile elastomers: Containing elements such as phosphorus and nitrogen, they act as ceramicizing agents and flame retardants, improving the stability of the material network structure, enhancing mechanical properties at room temperature, and providing flame retardancy. Ceramicization additives: Silicon carbide and zirconium oxide, as high-temperature resistant materials, promote the ceramicization of materials, improve the stability of materials at high temperatures, and enhance the anti-ablation performance of the ceramic layer.

2. The high-temperature ceramic insulating material according to claim 2, characterized in that: The mixing ratio is: 100-120 parts of EPDM rubber, 25-35 parts of hollow glass microspheres, 12-18 parts of fumed silica, 8-12 parts of aerogel silica, 15-30 parts of nitrile elastomer, 5-15 parts of silicon carbide, 3-8 parts of zirconium oxide, 1-5 parts of hafnium carbide and 1-5 parts of tantalum carbide. The final product is obtained through the steps of mixing, melting and vulcanization.

3. The high-temperature ceramic insulating material according to claim 3, characterized in that: The hafnium carbide and tantalum carbide form a high-temperature resistant ceramic phase skeleton at high temperature; The EPDM rubber, as the matrix of the material, is the basic carrier of the entire material structure, supporting the dispersion and combination of other components; Hollow glass microspheres act as rigid fillers, forming a "skeleton effect" to enhance the mechanical properties of the material; they participate in the ceramicization process and provide structural support for the ceramic layer; Fumed silica acts as a ceramic additive to assist in forming ceramic structures and enhance the ceramicization ability of the material; Aerogel silica enhances the interfacial bonding between the matrix and filler with its nano-scale pore structure, reduces internal defects in the material, and improves mechanical properties at room temperature. It also participates in ceramicization at high temperatures, promoting the formation of a dense ceramic layer. Silicon carbide and zirconium oxide: Promote the initial ceramicization of the material at around 600-800℃, forming a ceramic substance containing nitrogen, phosphorus, and silicon, which is cross-linked with the matrix through chemical bonds. Nitrogen and phosphorus elements help to melt silicon dioxide, preventing oxygen propagation and crack expansion; Ceramizing additives: Work synergistically with fused silica to prevent crack growth and oxygen propagation.

4. A method for preparing a high-temperature ceramic thermal insulation material, the high-temperature ceramic thermal insulation material according to any one of claims 1 to 3, characterized in that: The process includes raw material processing: drying hollow glass microspheres, fumed silica, aerogel silica, silicon carbide, zirconium oxide, hafnium carbide, tantalum carbide and other additives and fillers to remove moisture at a temperature of 80-100°C for 2-4 hours; cutting phosphorus and nitrogen-containing nitrile elastomers into small pieces for easy mixing.

5. The method for preparing a high-temperature ceramic insulating material according to claim 1, characterized in that: The process also includes internal kneading: adding EPDM rubber into an internal mixer, and plasticizing for 2-3 minutes at a temperature of 80-100°C and a rotation speed of 40-60 r / min; sequentially adding 30 parts of hollow glass microspheres, fumed silica, and 10 parts of aerogel silica, and continuing to mix for 3-5 minutes; then adding an elastomer containing flame retardants such as phosphorus and nitrogen, silicon carbide, zirconium oxide, hafnium carbide, and tantalum carbide, and mixing for 5-8 minutes to fully and evenly disperse the components to obtain a rubber mixture.

6. The method for preparing a high-temperature ceramic insulating material according to claim 1, characterized in that: The process also includes open mixing: transferring the mixed rubber after internal mixing to an open mixing mill, controlling the roller temperature of the open mixing mill at 50-70°C, adjusting the roller distance at 0.5-1mm, and performing 16 thin passes to further improve the uniformity and plasticity of the mixed rubber.

7. The method for preparing a high-temperature ceramic insulating material according to claim 1, characterized in that: Vulcanization: Cut the rubber compound after milling into appropriate size and put it into a flat vulcanizer for vulcanization. The vulcanization temperature is 160-180℃, the vulcanization pressure is 10-15MPa, and the vulcanization time is determined according to the thickness of the product, generally 10-30 minutes, to obtain high-performance EPDM rubber products.

8. The method for preparing a high-temperature ceramic insulating material according to claim 1, characterized in that: A step-by-step mixing process is carried out through a gradient ceramicization design: Step 1: Using EPDM rubber as the matrix, ceramicizing additives such as hollow glass microspheres, fumed silica, and aerogel silica are added to lay the foundation for the basic structure; Step 2: Add nitrile elastomer containing elements such as phosphorus and nitrogen and mix to form a material that can be initially ceramicized at 600-800°C; Step 3: Continue to add silicon carbide and zirconium oxide to mix, so that when the material is at about 1500℃, silicon dioxide will melt first with the help of nitrogen and phosphorus substances, preventing crack expansion and oxygen propagation; Step 4: Add hafnium carbide and tantalum carbide to the mixture based on step 3 to form a high-temperature resistant skeleton to further reduce the ablation rate.

9. The method for preparing a high-temperature ceramic insulating material according to claim 1, characterized in that: Step-by-step mixing process: By controlling the order of adding each component, nitrile elastomers of elements such as nitrogen and phosphorus → silicon carbide, zirconium oxide → hafnium carbide, tantalum carbide, gradient control of the ceramicization process is achieved.

10. Application of a high-temperature ceramic insulating material, the high-temperature ceramic insulating material according to any one of claims 1 to 9, characterized in that: Its applications are: when used in flame-retardant cable sheathing, the compressive strength after ceramicization is ≥10MPa, and the flame retardant grade reaches UL94V-0; when used in the thermal insulation layer of solid rocket engines, under the conditions of 3000K high-temperature gas flow, the linear ablation rate is ≤0.1mm / s, the mass ablation rate is ≤0.05g / s, and a dense ceramic layer can be formed on the surface without obvious holes or cracks.

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