A double-architecture compatible glue-free self-fusing composite high-temperature-resistant material and a dry method step-by-step preparation method thereof

Abstract

This invention discloses a dual-structure compatible adhesive-free self-fusing composite high-temperature resistant material and its dry stepwise preparation method, belonging to the technical field of inorganic-organic composite high-temperature resistant materials. The core of this material consists of 55-80% inorganic refractory chopped fibers and 20-45% organic high-temperature resistant chopped fibers. The organic fibers undergo in-situ fibrillation to construct a three-dimensional interlocking network with the inorganic fibers. No organic adhesive is used throughout the process; the material achieves integral bonding through the self-fusing of the organic fiber surface at 230-310℃. It is compatible with both large-pore continuous porous sandwich structures and discontinuous skeleton structures, and can be adapted for the composite preparation of a full range of organic fibers such as aramid, polyimide, and polyphenylene sulfide, as well as a full range of refractory fibers such as alumina, mullite, and zirconium oxide. This invention solves the defects of existing materials, such as easy separation between layers, high-temperature adhesive failure, simple structure, and narrow substrate coverage. It possesses excellent high-temperature resistance, tear resistance, and bending flexibility. The all-dry, solvent-free process is suitable for large-scale mass production and can be widely used in fire protection, aerospace thermal protection, chemical corrosion protection, and many other fields.

Description

Technical Field

[0001] This invention belongs to the technical field of inorganic-organic composite high-temperature resistant functional materials, specifically relating to a dual-structure compatible glue-free self-fluxing composite high-temperature resistant material, and a solvent-free and adhesive-free dry stepwise preparation method.

[0002] Flexible high-temperature resistant materials prepared by combining organic high-temperature resistant fibers and inorganic refractory fibers are currently the mainstream research and development direction in the fields of high-temperature protection and thermal insulation. Among them, aramid fibers have excellent flexibility, flame retardancy and processing performance, and can withstand short-term temperatures up to 500℃; alumina fibers have a high-temperature resistance threshold of over 1000℃, making them the core inorganic substrate for extreme heat-resistant scenarios. The composite material solution of the two has been widely used.

[0003] However, in the existing technology, the research and patent layout of such composite high-temperature resistant materials have long been limited to a single aramid / alumina combination, ignoring a large number of alternative substrates that can be adapted to the same process: special organic fibers such as polyimide and polyphenylene sulfide, as well as high-end refractory fibers such as mullite and zirconium oxide, all of which have the potential to be adapted to glue-free self-melting composite processes, and can achieve higher-end applications in ultra-high temperature and strong corrosion scenarios. However, there is no glue-free self-melting composite solution for such substrates in the existing technology, which has led to a long-term reliance on imports for materials in such high-end scenarios, and there is a defect of high-temperature failure of the bonding system.

[0004] Meanwhile, the preparation and application of existing aramid / alumina composite high-temperature resistant materials have long suffered from the following inherent technical defects: 1. Poor structural adaptability and simple architecture: Traditional sandwich composite materials can only use a single dense-pore nonwoven fabric interlayer, with small bonding area between upper and lower layers and weak interlayer bonding force, which easily leads to delamination and separation; simply increasing the nonwoven fabric pore size is a conventional size adjustment in this field, without matching substrate modification and bonding process synergy, and lacks creativity; and the discontinuous skeleton structure has the inherent tear resistance shortcomings, and the two types of structures cannot be compatible with the same mass production process.

[0005] 2. Insufficient reliability of the bonding system: The industry mainstream adopts organic glue impregnation and composite, but the upper limit of the temperature resistance of the adhesive is much lower than that of refractory fiber. It is prone to carbonization failure under high temperature environment, which will induce the overall delamination and detachment of the material. At the same time, it will also reduce the basic insulation and flame retardant properties of the material and introduce excess chemical impurities.

[0006] 3. High industrialization cost of process routes: The preparation routes such as wet papermaking and electrospinning are highly dependent on the consumption of organic solvents and drying equipment, resulting in a lot of waste emissions, lengthy process flow, high barriers to entry for small and medium-sized enterprises, and inability to achieve continuous roll production.

[0007] 4. Loose microstructure of materials: The physically simple mixture of fibers does not have a stable entanglement network, and the finished product is prone to fiber shedding and brittleness, making it impossible to balance high temperature resistance and bending performance requirements at the same time.

[0008] A search revealed that there is currently no complete solution in the existing technology that can synergistically combine four types of technologies: in-situ dry fibrillation of general-purpose organic fibers, high-temperature glueless self-fusion bonding, large-pore continuous porous interlayer reinforcement, and stress release of discontinuous skeleton. This solution is applicable to the composite preparation of a full range of special high-temperature resistant fibers and has room for further improvement and enhancement. Summary of the Invention

[0009] Purpose of the invention To overcome the shortcomings of existing technologies, such as simple structure, high-temperature failure of bonding systems, complex processes, and incompatibility of dual-structure mass production, and to address the issues of narrow coverage and insufficient adaptability to high-end applications of existing substrates, this invention provides a dual-structure compatible adhesive-free self-fluxing composite high-temperature resistant material and its dry stepwise preparation method. Through microstructure modification and process synergy, it achieves adhesive-free integral molding, while being compatible with both large-pore continuous sandwich and discontinuous skeleton core structures. It can be adapted to the composite of a full range of organic high-temperature resistant fibers and inorganic refractory fibers, taking into account the material's high-temperature resistance, mechanical properties, and flexibility, adapting to multiple application scenarios, and meeting the needs of patent protection and low-cost industrialization. Technical solution

[0010] To achieve the above-mentioned objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a dual-structure compatible adhesive-free self-fluxing composite high-temperature resistant material, comprising at least one composite film layer; the composite film layer, by mass percentage, is composed of 55-80% inorganic refractory chopped fibers and 20-45% organic high-temperature resistant chopped fibers; The organic high-temperature resistant fiber is selected from one or more of the following: para-aramid, meta-aramid, polyimide fiber, polyphenylene sulfide fiber, and polyarylate fiber; The inorganic refractory fiber is selected from one or more of the following: alumina fiber, polycrystalline mullite fiber, zirconium oxide fiber, high silica fiber, and high-purity aluminosilicate fiber; The organic high-temperature resistant chopped fibers are in-situ fibrillated by high-speed stirring at 3000~15000rpm, and microfibrils are generated on the surface, which are then entangled with the inorganic refractory chopped fibers to form a three-dimensional interlocking micro network. No organic adhesives are added to the material throughout the process, and the layers are bonded together by the self-melting of the organic fiber surface at a high temperature of 230~310℃. The material as a whole has a sandwich laminated structure, which may adopt a large-pore continuous porous sandwich structure or a discontinuous skeleton sandwich structure.

[0011] Furthermore, the inorganic refractory chopped fiber has a length of 2~10mm and a single filament diameter of 3~20μm; the organic high-temperature resistant chopped fiber has a length of 2~10mm.

[0012] Furthermore, the large-pore continuous porous sandwich structure includes an upper composite membrane, a middle large-pore continuous porous nonwoven fabric sandwich layer, and a lower composite membrane; the large-pore continuous porous nonwoven fabric is a complete and interconnected uncut substrate with a perforation rate of ≥60%, and the upper and lower composite membranes are directly self-fused and bonded in the large-pore void area, while the continuous substrate area provides full-width uninterrupted tear-resistant support.

[0013] Furthermore, the discontinuous skeleton sandwich structure includes an upper composite membrane, a middle discontinuous skeleton layer, and a lower composite membrane; the discontinuous skeleton is a grid-like, strip-like, or lattice-like structure, and the skeleton as a whole accounts for 30-80% of the total material area; the skeleton contact area forms a mechanical anchoring bond, and the upper and lower composite membranes in the non-skeleton area are directly self-fused and connected to form the structure.

[0014] Furthermore, the materials used for the large-pore continuous porous nonwoven fabric and the discontinuous skeleton are independently selected from one or more of the following: porous aramid nonwoven fabric, polyimide nonwoven fabric, basalt fiber cloth, porous ceramic fiber paper, and glass fiber cloth, and are used in combination.

[0015] Furthermore, the total thickness of the material is 0.05~2.00mm, and the basis weight is 50~2000g / m².

[0016] Secondly, the present invention provides a dry stepwise preparation method for the above-mentioned dual-structure compatible adhesive-free self-fluxing composite high-temperature resistant material, which adopts a dry solvent-free process throughout the entire process and does not add any organic adhesives, including the following steps: S1 Raw material pretreatment: Dry the inorganic refractory chopped fiber at 100~120℃ for 1~3h to remove free water, and vacuum dry the organic high temperature resistant chopped fiber until the internal moisture content is ≤0.5% to avoid bubbling defects during hot pressing. S2 In-situ fibrillation: Pretreated inorganic refractory chopped fibers and organic high-temperature resistant chopped fibers are mixed according to the formula and put into a high-speed mixer with a cooling jacket. The mixture is stirred at a speed of 3000~15000rpm for 3~20min, and the temperature is controlled at ≤80℃ throughout the process to prepare a fluffy mixture in which the fibers are entangled. S3 One-time high-temperature roll forming: After the loose mixture is evenly spread, it is fed into a two-roller hot press and rolled into shape under the conditions of temperature 230~310℃, pressure 5~20MPa and roller speed 0.3~2m / min. A homogeneous composite film is prepared by controlling the roller gap. S4 Secondary composite molding of substructure: Select the corresponding route according to the target structure. Route A is to align and clamp the upper and lower composite membranes with a large-pore continuous porous non-woven fabric interlayer, and perform secondary hot pressing molding using the same temperature and pressure parameters as in step S3. Route B is to lay a discontinuous skeleton on the lower composite membrane and then cover it with the upper composite membrane, and perform secondary hot pressing molding using the same temperature and pressure parameters as in step S3. S5 Pressure Holding and Cooling Shaping: After the secondary composite is completed, maintain pressure and cool to ≤100℃ before releasing the pressure to eliminate internal stress in the material and avoid warping and delamination problems in the later stage; S6 Post-processing: Cutting, punching or surface finishing of the shaped material to obtain finished rolls or sheets.

[0017] Furthermore, the temperature and pressure process parameters used in the first high-temperature rolling in step S3 and the second composite molding in step S4 are completely consistent, ensuring the uniformity of material molding and the stability of interlayer bonding.

[0018] Thirdly, this invention provides applications of the above-mentioned dual-structure compatible glue-free self-fluxing composite high-temperature resistant material in the fields of fire protection, electrical insulation, power battery thermal insulation, aerospace thermal protection, industrial high-temperature coating, automotive flame retardancy, building fire protection, chemical corrosion protection and high-temperature protection, ultra-high temperature metallurgical thermal insulation, and nuclear industry insulation protection. Beneficial effects

[0019] Compared with the prior art, the present invention has the following outstanding advantages (based on theoretical analysis and structural advantages): 1. Full-substrate compatibility design: Through a universal process, it can be adapted to the full range of organic high-temperature resistant fibers and inorganic refractory fibers, covering the full performance gradient from low-cost civilian scenarios to ultra-high temperature high-end scenarios. It can achieve compatibility of 16 different material combinations with one process to meet the customized needs of different customers.

[0020] 2. Dual-architecture compatible design: A single process is used to be compatible with two types of architectures: large-pore continuous sandwich (providing high tear resistance) and discontinuous skeleton (providing high flexibility), achieving full coverage of mid-range mass production and high-end high-value-added scenarios.

[0021] 3. Adhesive-free self-melting bonding system: Utilizing the self-melting properties of organic fibers on the surface at 230~310℃ to replace organic adhesives, completely solving the problem of high-temperature adhesive carbonization failure, ensuring long-term stability of insulation and flame retardant properties, and adapting to the self-melting temperature range of different organic fibers.

[0022] 4. In-situ fibrillation micro-modification: High-speed stirring causes fibrillation on the surface of organic fibers, forming a three-dimensional interlocking network with inorganic fibers, preventing fiber shedding, balancing high temperature resistance and flexibility, and adapting to the fibrillation characteristics of different organic fibers.

[0023] 5. All-dry process: No solvents, no waste emissions, short process, low equipment investment, can realize continuous mass production of roll materials, suitable for small and medium-sized enterprises to start production quickly.

[0024] Supplementary explanation regarding the rationality of process parameters: - Temperature 230~310℃: Below this range, the self-adhesiveness of organic fibers is insufficient; above this range, organic fibers are prone to thermal oxidative degradation, leading to a decrease in toughness. This range can cover the self-melting temperature requirements of all suitable organic fibers.

[0025] - Rotation speed 3000~15000rpm: Adjusted based on the fibrillation characteristics of different organic fibers. The core objective is to achieve fibrillation rather than cutting the fibers. The optimal parameters can be selected within this range for different fibers. Those skilled in the art can adjust it according to the principle of energy equivalence. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the laminated cross-sectional structure of the composite high-temperature resistant material with a large-pore continuous porous sandwich structure as described in this invention.

[0027] In the figure: 1 is the upper composite membrane, 2 is the continuous substrate, 3 is the lower composite membrane, and 4 is the macroporous / upper and lower membrane fusion zone.

[0028] Figure 2 This is a schematic diagram of the planar structure of the composite high-temperature resistant material of the discontinuous skeleton sandwich structure described in this invention.

[0029] In the figure: 1 is the upper composite film, 2 is the lower composite film, 3 is the discontinuous grid skeleton / skeleton contact area, and 4 is the non-skeleton self-melting area.

[0030] Figure 3 This is a process flow diagram of the dry stepwise preparation method described in this invention.

[0031] In the diagram: S1 is the raw material pretreatment step, S2 is the in-situ fibrillation and blending step, S3 is the first high-temperature roll forming step, S4 is the secondary composite molding step with separate structure, S5 is the pressure holding, cooling and shaping step, and S6 is the cutting and post-processing step. Detailed Implementation

[0032] The present invention will now be described in detail through specific embodiments.

[0033] Example 1: Basic single-layer aramid / alumina composite film Composition: 70% alumina chopped fibers (3~6mm in length, 5~10μm in diameter), 30% para-aramid chopped fibers (3~6mm in length).

[0034] Preparation: S1 Dry at 110℃ for 2 hours + vacuum dry until water content ≤0.5%; S2 Stir at 8000rpm for 10 minutes (temperature control ≤60℃); S3 Roll press at 270℃, 12MPa, 1m / min; S4 Hold pressure and cool to 80℃ to release pressure.

[0035] Example 2: Large-pore continuous porous sandwich structure The upper / lower composite membrane is the same as in Example 1, with the middle interlayer being a large-pore continuous aramid nonwoven fabric with a perforation rate of 65%. Preparation: S1-S3 are the same as in Example 1; S4 is route A (secondary hot pressing with the same temperature and pressure parameters); S5 is the same as in Example 1.

[0036] Example 3: Discontinuous skeleton sandwich structure The upper / lower composite membrane is the same as in Example 1, with a discontinuous backbone of 10mm×10mm aramid mesh (occupying 60% of the area). Preparation: S1-S3 are the same as in Example 1; S4 is route B (after laying the mesh, cover with the upper membrane, and perform a second hot pressing at the same temperature); S5 is the same as in Example 1.

[0037] Example 4: For electrical insulation purposes Composition: 60% alumina chopped fibers, 40% meta-aramid chopped fibers; large-pore continuous sandwich, with the middle sandwich being a 60% perforated polyimide nonwoven fabric. Preparation: S1 Drying at 105℃ for 2.5h; S2 Stirring at 6000rpm for 15min (temperature control ≤70℃); S3 260℃, 10MPa, 0.8m / min; S4 Same temperature and pressure as route A; S5 Cooling to 90℃ and depressurizing.

[0038] Example 5: PI / mullite ultra-high temperature composite film Composition: 70% polycrystalline mullite chopped fibers (3~6mm in length, 5~10μm in diameter), 30% polyimide chopped fibers (3~6mm in length).

[0039] Preparation: S1 Drying at 115℃ for 2 hours + vacuum drying until water content ≤0.4%; S2 Stirring at 10000rpm for 8 minutes (temperature control ≤70℃); S3 Roll pressing at 280℃, 14MPa, and 0.9m / min; S4 Holding pressure and cooling to 85℃ before depressurization. The material prepared in this example can withstand ultra-high temperatures of 1600℃, making it suitable for thermal protection scenarios in aero-engines.

[0040] Example 6: PPS / High-Silica Anticorrosion Composite Membrane Composition: 65% high-silica chopped fibers (4-7 mm in length, 6-12 μm in diameter), 35% polyphenylene sulfide chopped fibers (4-7 mm in length).

[0041] Preparation: S1 Drying at 110℃ for 2.5h + vacuum drying until water content ≤0.5%; S2 Stirring at 8000rpm for 12min (temperature control ≤75℃); S3 Roll pressing at 290℃, 15MPa, 0.8m / min; S4 Holding pressure and cooling to 90℃ before depressurization. The material prepared in this example exhibits excellent resistance to acid and alkali corrosion, making it suitable for high-temperature anti-corrosion coating applications in chemical industries.

[0042] Example 7: Aramid / Zirconium Oxide Extreme Heat Protection Composite Film Composition: 60% zirconia chopped fibers (3-6 mm in length, 4-8 μm in diameter), 40% para-aramid chopped fibers (3-6 mm in length).

[0043] Preparation: S1 Drying at 120℃ for 1.5h + vacuum drying until water content ≤0.3%; S2 Stirring at 9000rpm for 10min (temperature control ≤65℃); S3 Roll pressing at 270℃, 16MPa, 0.7m / min; S4 Holding pressure and cooling to 80℃ before depressurization. The material prepared in this example can withstand extreme high temperatures of 1650℃, making it suitable for extreme thermal protection scenarios in aerospace.

[0044] Example 8: Low-cost composite membrane of PAR / alumina silicate Composition: 75% high-purity aluminum silicate chopped fibers (5~8mm in length, 6~15μm in diameter), 25% polyarylate chopped fibers (5~8mm in length).

[0045] Preparation: S1 Drying at 105℃ for 3 hours + vacuum drying until moisture content ≤0.5%; S2 Stirring at 7000rpm for 15 minutes (temperature control ≤70℃); S3 Roll pressing at 260℃, 10MPa, and 1.1m / min; S4 Holding pressure and cooling to 85℃ before depressurization. The material prepared in this embodiment costs only 40% of traditional aramid / alumina materials, making it suitable for large-scale building fire protection scenarios.

[0046] Comparative Example 1 (without in situ profibrillation) Difference from Example 1: High-speed mixing (S2) was not performed; only low-speed physical mixing was used. Expected consequences: weak fiber bonding, easy powder shedding and stratification, and deterioration in high-temperature resistance.

[0047] Comparative Example 2 (Hot-pressing temperature 220℃) Difference from Example 2: Hot pressing temperature in S3 and S4 is 220℃ (lower than 230℃). Expected result: The organic fibers do not fully self-melt, resulting in insufficient interlayer bonding and easy delamination after high-temperature aging.

[0048] Performance Analysis (Structure-Performance Reasoning) - In Example 2, the large-pore void area allows the upper and lower composite films to directly contact and self-melt, forming a "spot weld" to strengthen the bond, and the continuous substrate provides full-width tear resistance support.

[0049] - In Example 3, the non-skeleton area directly self-melts, while the skeleton area provides mechanical anchoring. At the same time, the discontinuous structure cuts off the transmission of thermal stress, improving bending flexibility.

[0050] - In Examples 5-8, different substrate combinations can achieve different performance gradients, covering the full range of needs from low-cost civilian use to ultra-high temperature high-end applications. At the same time, they can all achieve glue-free self-melting composite, solving the bonding failure problem of traditional solutions.

[0051] - Comparative Example 1 lacks a three-dimensional entanglement network, and Comparative Example 2 has insufficient self-fusion, neither of which can achieve the effect of the present invention.

[0052] In summary, this invention achieves compatibility with a glue-free self-fluxing dual architecture across all substrates through microstructure-process synergy, representing a significant advancement.

Claims

1. A dual-structure compatible adhesive-free self-fluxing composite high-temperature resistant material, comprising a layered structure formed by organic high-temperature resistant fibers and inorganic refractory fibers, characterized in that, The material comprises at least one composite film layer, which, by mass percentage, consists of 55-80% inorganic refractory chopped fibers and 20-45% organic high-temperature resistant chopped fibers. The organic high-temperature resistant fibers are selected from one or more of para-aramid, meta-aramid, polyimide fibers, polyphenylene sulfide fibers, and polyarylate fibers. The inorganic refractory fibers are selected from one or more of alumina fibers, polycrystalline mullite fibers, zirconium oxide fibers, high-silica fibers, and high-purity aluminum silicate fibers. The organic high-temperature resistant chopped fibers are subjected to in-situ fibrillation by high-speed stirring at 3000-15000 rpm, resulting in the formation of fine fibrils on the surface, which then entangle with the inorganic refractory chopped fibers to form a three-dimensional interlocking micro-network. No organic adhesives are added to the material throughout the process; the layers are bonded together by the self-melting of the organic fiber surface at a high temperature of 230-310℃. The material has a sandwich-like laminated structure, optionally employing a large-pore continuous porous sandwich structure or a discontinuous skeleton sandwich structure.

2. The dual-structure compatible adhesive-free self-fluxing composite high-temperature resistant material according to claim 1, characterized in that, The combination of organic high-temperature resistant fiber and inorganic refractory fiber is selected from: (1) Polyimide fiber and polycrystalline mullite fiber, corresponding to a high-speed stirring speed of 4000~13000 rpm and a hot pressing temperature of 250~300℃; (2) Polyphenylene sulfide fiber and high silica fiber, corresponding to a hot pressing temperature of 270~300℃ and a hot pressing pressure of 8~18MPa; (3) Aramid fiber and zirconium oxide fiber; (4) Polyarylate fiber and high-purity aluminum silicate fiber.

3. The dual-structure compatible adhesive-free self-fluxing composite high-temperature resistant material according to any one of claims 1 or 2, characterized in that, The inorganic refractory chopped fibers have a length of 2~10mm and a single filament diameter of 3~20μm; the organic high-temperature resistant chopped fibers have a length of 2~10mm.

4. The dual-structure compatible adhesive-free self-fluxing composite high-temperature resistant material according to any one of claims 1 or 2, characterized in that, The large-pore continuous porous sandwich structure includes an upper composite membrane, a middle large-pore continuous porous nonwoven fabric sandwich layer, and a lower composite membrane; the large-pore continuous porous nonwoven fabric is a complete and interconnected uncut substrate with a perforation rate of ≥60%. The upper and lower composite membranes are directly self-fused and bonded in the large-pore void areas, and the continuous substrate area provides full-width uninterrupted tear resistance support.

5. The dual-structure compatible adhesive-free self-fluxing composite high-temperature resistant material according to any one of claims 1 or 2, characterized in that, The discontinuous skeleton sandwich structure includes an upper composite membrane, a middle discontinuous skeleton layer, and a lower composite membrane; the discontinuous skeleton is a grid-like, strip-like, or lattice-like structure, and the skeleton as a whole accounts for 30-80% of the total material area; the skeleton contact area forms a mechanical anchoring bond, and the upper and lower composite membranes in the non-skeleton area are directly self-fused and connected.

6. The dual-structure compatible adhesive-free self-fluxing composite high-temperature resistant material according to claim 4 or 5, characterized in that, The materials used for the large-pore continuous porous nonwoven fabric and the discontinuous skeleton are independently selected from one or more of the following: porous aramid nonwoven fabric, polyimide nonwoven fabric, basalt fiber cloth, porous ceramic fiber paper, and glass fiber cloth, and are used in combination.

7. The dual-structure compatible adhesive-free self-fluxing composite high-temperature resistant material according to any one of claims 1 or 2, characterized in that, The total thickness of the material is 0.05~2.00mm, and the weight is 50~2000g / m².

8. A dry stepwise preparation method for a dual-structure compatible glue-free self-fluxing composite high-temperature resistant material, used to prepare the composite high-temperature resistant material according to any one of claims 1 to 7, comprising raw material pretreatment and hot pressing steps, characterized in that, The entire process employs a dry, solvent-free process without adding any organic adhesives. Specifically, it includes the following steps: S1 Raw material pretreatment: Inorganic refractory chopped fibers are dried at 100-120℃ for 1-3 hours to remove free water; organic high-temperature resistant chopped fibers are vacuum dried until the internal moisture content is ≤0.5%; S2 In-situ fibrillation and blending: The pretreated inorganic refractory chopped fibers and organic high-temperature resistant chopped fibers are mixed according to the specified ratio and fed into a high-speed mixer with a cooling jacket. The mixture is stirred at 3000-15000 rpm for 3-20 minutes, with the temperature controlled at ≤80℃ throughout, to prepare a fluffy mixture with intertwined fibers; S3 One-time high-temperature roll forming: The fluffy mixture is evenly spread and fed into a double-roller hot press. It is roll-formed at 230-310℃, 5-20 MPa, and 0.3-2 m / min, and a homogeneous composite film is obtained by controlling the roll gap; S4 Secondary composite molding of substructure: Select the corresponding route according to the target structure. Route A is to align and clamp the upper and lower composite films with a large-pore continuous porous non-woven fabric interlayer, and perform secondary hot pressing molding using the same temperature and pressure parameters as in step S3; Route B is to lay a discontinuous skeleton on the lower composite film and then cover it with the upper composite film, and perform secondary hot pressing molding using the same temperature and pressure parameters as in step S3; S5 Pressure holding and cooling shaping: After the secondary composite is completed, maintain the pressure and cool to ≤100℃ before releasing the pressure to eliminate the internal stress of the material; S6 Post-processing: Cut, punch or surface finish the shaped material to obtain the finished roll or sheet material.

9. The dry stepwise preparation method according to claim 8, characterized in that, The temperature and pressure process parameters used in the first high-temperature rolling process of step S3 and the second composite molding process of step S4 are completely the same.

10. The application of the dual-structure compatible glue-free self-fluxing composite high-temperature resistant material according to any one of claims 1 to 7 in the fields of fire protection, electrical insulation, power battery thermal insulation, aerospace thermal protection, industrial high-temperature coating, automotive flame retardancy, building fire protection, chemical corrosion protection and high-temperature protection, ultra-high temperature metallurgical thermal insulation, and nuclear industry insulation protection.

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