High-strength multilayer thermal insulation material and method for producing same

Abstract

The present application relates to a kind of high-strength multilayer thermal insulation material and its preparation method.The method includes the following steps: phenolic fiber, zirconium oxide fiber, alumina nanosheet and phosphate solution are uniformly dispersed with water, to obtain dispersion system;Porous phenolic fiber cloth is laid in the papermaking equipment as filter medium, then the dispersion system is papered by the papermaking equipment with porous phenolic fiber cloth, to obtain preform;The preform includes porous phenolic fiber cloth and the papered material obtained on porous phenolic fiber cloth;Multilayer preform is laid in the setting mold layer by layer to be shaped and dried, then carbonization is carried out under inert atmosphere, and high-strength multilayer thermal insulation material is prepared.The present application effectively solves the traditional interface effect of reflecting screen and zirconium oxide fiber, greatly improves the mechanical strength of multilayer thermal insulation material, and lays a solid material foundation for the application of multilayer thermal insulation material in extreme environment.

Description

Technical Field

[0001] This invention belongs to the technical field of zirconia fiber thermal insulation materials, and particularly relates to a high-strength multilayer thermal insulation material and its preparation method. Background Technology

[0002] As various aerospace vehicles develop towards higher Mach numbers and longer endurance, they face increasingly harsh thermal environments, placing entirely new demands on thermal insulation materials. High-temperature resistant multilayer thermal insulation materials, due to their excellent high-temperature insulation performance, demonstrate significant advantages in the thermal protection structure of flight systems.

[0003] Current high-temperature resistant multilayer thermal insulation materials are mainly made of zirconium oxide or alumina fibers as the fiber layer, with graphite, carbon fiber cloth, or silicon carbide carbon-based reflectors in the middle. The spacer layer and fiber layer are bonded together with high-temperature resistant adhesives, but the interlayer adhesives are ineffective, resulting in insufficient shear strength. Furthermore, the insufficient thermophysical matching between carbon-based materials and inorganic oxide materials leads to significant deficiencies in compressive strength, making the material prone to strength and structural failure during long-term high-temperature applications. Therefore, it is essential to design and develop new high-strength multilayer thermal insulation materials that can effectively improve mechanical strength while ensuring thermal insulation performance.

[0004] In summary, it is essential to provide a high-strength multilayer thermal insulation material and its preparation method. Summary of the Invention

[0005] To address one or more technical problems existing in the prior art, this invention provides a high-strength multilayer thermal insulation material and its preparation method.

[0006] In a first aspect, the present invention provides a method for preparing a high-strength multilayer thermal insulation material, the method comprising the following steps:

[0007] (1) Disperse phenolic fiber, zirconium oxide fiber, alumina nanosheets and phosphate solution evenly with water to obtain a dispersion system;

[0008] (2) The porous phenolic fiber cloth is laid flat in the papermaking equipment as a filter medium, and then the dispersion system is papermade by the papermaking equipment with the porous phenolic fiber cloth laid flat to obtain a preform; the preform includes the porous phenolic fiber cloth and the papermaking material obtained on the porous phenolic fiber cloth.

[0009] (3) The multi-layer prefabricated body is laid layer by layer in a shaping mold for shaping and drying, and then carbonized in an inert atmosphere to obtain a high-strength multi-layer thermal insulation material.

[0010] Preferably, in step (1): the mass ratio of the zirconium oxide fiber to the phenolic fiber is (4-19):1; the mass ratio of the alumina nanosheet to the phosphate solution is (1-4):(1-9); and / or the phosphate solution is an aluminum dihydrogen phosphate solution, wherein the aluminum dihydrogen phosphate solution contains an aluminum dihydrogen phosphate mass fraction of 20-50%.

[0011] Preferably, in step (1): the diameter of the zirconium oxide fiber is 1 to 10 μm; and / or the diameter of the phenolic fiber is 200 to 1000 nm.

[0012] Preferably, in step (1): the dispersion rotation speed is 4000-10000 r / min, and the dispersion time is 3-40 min.

[0013] Preferably, in step (2): the pore size of the porous phenolic fiber cloth is 500 nm to 2 μm; and / or the thickness of the porous phenolic fiber cloth is 10 to 200 μm.

[0014] Preferably, the thickness of a single layer of the prefabricated body is 0.5 to 2 mm; and / or the thickness of the high-strength multilayer thermal insulation material is 15 to 25 mm.

[0015] Preferably, in step (3), the temperature for the shaping and drying process is 200℃~300℃.

[0016] Preferably, in step (3): the carbonization temperature is 500-900℃, and the carbonization time is 10-20h.

[0017] Preferably, in step (1): potassium hexatitanate (K2Ti6O) is also added to the dispersion system. 13 Nanowires; preferably, the potassium hexatite K2Ti6O 13 The mass ratio of nanowires to alumina nanosheets is 1:(1-2).

[0018] In a second aspect, the present invention provides a high-strength multilayer thermal insulation material prepared by the preparation method described in the first aspect of the present invention.

[0019] Compared with the prior art, the present invention has at least the following beneficial effects:

[0020] (1) This invention uses zirconia fiber and phenolic nanofiber as the main materials. By introducing alumina nanosheets and phosphate (aluminum dihydrogen phosphate) solution as binders, the fiber overlap and bonding area are effectively improved, thus enhancing the strength of the material. At the same time, this invention uses phenolic nanofiber as the flexible building block and forms carbon nanofiber through carbonization. The carbonization process effectively enhances the interfacial interaction between zirconia fiber and phenolic fiber, thereby improving the strength and flexibility of the composite material. In addition, this invention uses porous phenolic fiber cloth as the precursor of the reflector. Through hot pressing to assist the subsequent carbonization process, a dense carbon-based reflector is constructed. This method effectively solves the traditional interfacial interaction between the reflector and zirconia fiber, greatly improving the mechanical strength of the multilayer thermal insulation material and laying a solid material foundation for the application of multilayer thermal insulation materials in extreme environments.

[0021] (2) In some preferred embodiments of the present invention, potassium hexatitanate (K2Ti6O) is also introduced into the material. 13 Nanowires, as discovered in this invention, the K2Ti6O 13 The introduction of nanowires helps to further improve the strength, flexibility, and thermal insulation performance of high-strength multilayer thermal insulation materials; a possible reason is that K2Ti6O 13 The fibrous structure of nanowires endows them with very high tensile strength, enabling them to act as a skeletal reinforcement in composite materials. Meanwhile, K2Ti6O... 13 Nanowires can be uniformly distributed throughout the material matrix, forming a dense reinforcing network structure. This network structure can effectively block crack propagation, enhance the overall strength of the material, and fill any micropores or voids that may exist in the material, making the material structure more compact and effectively reducing defects in the material; at the same time, due to K2Ti6O 13 The nanoscale size and aspect ratio of nanowires endow them with good flexibility, which allows for favorable interactions with the matrix material. This enhances both strength and flexibility of the material. Furthermore, K2Ti6O... 13 The fibrous structure of nanowires can prevent the rapid propagation of cracks in materials. This crack-resistant effect can also significantly improve the fracture toughness of materials, making them less prone to brittle fracture even under external stress, thus enhancing their flexibility; in addition, K2Ti6O 13 The introduction of nanowires can also improve the thermal insulation performance of high-strength multilayer thermal insulation materials, K2Ti6O 13 The fibrous structure of nanowires can form complex three-dimensional networks within materials, effectively hindering heat conduction paths. This network structure restricts heat conduction within the material, thereby improving its thermal insulation performance. Furthermore, K₂Ti₆O 13 Nanowires have a certain blocking effect on infrared radiation, reducing infrared radiation, lowering the thermal conductivity of insulation materials, and effectively enhancing the insulation performance of materials. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0023] In a first aspect, the present invention provides a method for preparing a high-strength multilayer thermal insulation material, the method comprising the following steps:

[0024] (1) Disperse phenolic fiber, zirconium oxide fiber, alumina nanosheets and phosphate solution evenly with water to obtain a dispersion system; In this invention, the total mass percentage of phenolic fiber, zirconium oxide fiber, alumina nanosheets and phosphate in the dispersion system can be, for example, 8 to 25%; This invention does not specifically limit the source of phenolic fiber, zirconium oxide fiber, alumina nanosheets, etc., and products that can be purchased directly or products prepared by existing methods can be used;

[0025] (2) A porous phenolic fiber cloth (porous phenolic fiber cloth) is laid flat in a papermaking equipment as a filter medium, and then the dispersion system is papermade by the papermaking equipment with the porous phenolic fiber cloth laid flat to obtain a preform; the preform includes a porous phenolic fiber cloth and a papermaking material obtained on the porous phenolic fiber cloth; the present invention does not specifically limit the papermaking process, which is a conventional technology in the field;

[0026] (3) The multi-layer preforms are laid layer by layer in a shaping mold (hot pressing mold) for shaping and drying, and then carbonized in an inert atmosphere to obtain a high-strength multi-layer thermal insulation material. When laying layer by layer, the porous phenolic fiber cloth and papermaking material contained in each preform are alternately arranged. The present invention does not have special requirements for the pressure of shaping and drying, i.e. the pressure assisted by hot pressing. Those skilled in the art can choose conventionally, for example, 1 to 2 MPa.

[0027] This invention uses zirconia fibers and phenolic nanofibers as the main materials. By introducing alumina nanosheets and phosphate (aluminum dihydrogen phosphate) solution as binders, the overlap and bonding area of ​​the fibers are effectively increased, thereby enhancing the strength of the material. Simultaneously, this invention uses phenolic nanofibers as the flexible building block, forming carbon nanofibers through carbonization. The carbonization process effectively enhances the interfacial interaction between zirconia fibers and phenolic fibers, improving the strength and flexibility of the composite material. Furthermore, this invention uses porous phenolic fiber cloth as the precursor for the reflector, constructing a dense carbon-based reflector through a hot-pressed, assisted carbonization process. This method effectively solves the traditional interfacial interaction between the reflector and zirconia fibers, greatly improving the mechanical strength of the multilayer thermal insulation material and laying a solid material foundation for the application of multilayer thermal insulation materials in extreme environments.

[0028] According to some specific embodiments, the preparation of the high-strength multilayer thermal insulation material includes the following steps:

[0029] ① Use porous phenolic fiber cloth as a filter medium and lay it flat on the dispersion-forming (paper making) integrated equipment;

[0030] ② Weigh a certain mass of phenolic fiber, zirconium oxide fiber, alumina nanosheets and aluminum dihydrogen phosphate solution and add them to the dispersion-forming (paper making) integrated equipment. Start the program and add water for rapid dispersion to obtain a dispersion system. Then, the dispersion system is paper made on porous phenolic fiber cloth to obtain paper making material.

[0031] ③ The papermaking material, together with the bottom filter medium (porous phenolic fiber cloth), is laid layer by layer on a hot press mold for shaping and drying.

[0032] ④ Finally, the shaped and dried material is placed in an inert atmosphere furnace for carbonization to obtain a high-strength multilayer thermal insulation material.

[0033] According to some preferred embodiments, in step (1): the mass ratio of the zirconium oxide fiber to the phenolic fiber is (4-19):1 (e.g., 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1 or 19:1); the mass ratio of the alumina nanosheets to the phosphate solution is (1-4):(1-9); in this invention, preferably, the sum of the mass amounts of the alumina nanosheets and the phosphate solution is 25-60% of the sum of the mass amounts of the phenolic fiber and the zirconium oxide fiber; and / or the phosphate solution is an aluminum dihydrogen phosphate solution, wherein the aluminum dihydrogen phosphate solution (i.e., an aqueous solution of aluminum dihydrogen phosphate) contains an aluminum dihydrogen phosphate mass fraction of 20-50%.

[0034] According to some preferred embodiments, in step (1): the diameter of the zirconium oxide fiber is 1 to 10 μm; and / or the diameter of the phenolic fiber (phenolic nanofiber) is 200 to 1000 nm.

[0035] According to some preferred embodiments, in step (1): the dispersion rotation speed is 4000 to 10000 r / min (e.g., 4000, 5000, 6000, 7000, 8000, 9000 or 10000 r / min), and the dispersion time is 3 to 40 min (e.g., 3, 5, 8, 10, 15, 20, 25, 30, 35 or 40 min).

[0036] According to some preferred embodiments, in step (2): the pore size of the porous phenolic fiber cloth is 500 nm to 2 μm (e.g., 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1 μm, 1.2 μm, 1.5 μm, 1.8 μm or 2 μm); and / or the thickness of the porous phenolic fiber cloth (i.e., the porous phenolic fiber cloth) is 10 to 200 μm (e.g., 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190 or 200 μm); in this invention, the porosity of the porous phenolic fiber cloth is, for example, 50 to 70%.

[0037] According to some preferred embodiments, the thickness of the single-layer preform is 0.5 to 2 mm (e.g., 0.5, 1, 1.2, 1.5, 1.8, or 2 mm); and / or the thickness of the high-strength multilayer thermal insulation material is 15 to 25 mm (e.g., 15, 18, 20, or 25 mm); in this invention, preferably, the thickness of the internal accommodating space of the shaping mold is 15 to 25 mm, and in this invention, the thickness of the internal accommodating space of the shaping mold corresponds to the thickness of the high-strength multilayer thermal insulation material obtained.

[0038] According to some preferred embodiments, in step (3): the temperature of the shaping and drying is 200℃~300℃ (e.g. 200℃, 210℃, 220℃, 230℃, 240℃, 250℃, 260℃, 270℃, 280℃, 290℃ or 300℃), and the shaping and drying time is, for example, 12~36h, preferably 24h.

[0039] According to some preferred embodiments, in step (3): the carbonization temperature is 500 to 900°C (e.g., 500°C, 600°C, 700°C, 800°C or 900°C), and the carbonization time is 10 to 20 hours (e.g., 10, 12, 15, 18 or 20 hours).

[0040] According to some preferred embodiments, in step (1): potassium hexatitanate (K2Ti6O) is also added to the dispersion system. 13 Nanowires (i.e., K2Ti6O) 13 Nanowires); This invention relates to K2Ti6O 13 The source and size of the nanowires are not specifically limited; they can be purchased products or synthesized using existing methods. In this invention, the potassium hexatitanate K2Ti6O... 13 The diameter of the nanowire is, for example, 80–120 nm, and the length is, for example, 40–50 μm.

[0041] The present invention preferably introduces potassium hexatitanate (K₂Ti₆O) into the material. 13 Nanowires, as discovered in this invention, the K2Ti6O 13 The introduction of nanowires helps to further improve the strength, flexibility, and thermal insulation performance of high-strength multilayer thermal insulation materials; a possible reason is that K2Ti6O 13 The fibrous structure of nanowires endows them with very high tensile strength, enabling them to act as a skeletal reinforcement in composite materials. Meanwhile, K2Ti6O... 13 Nanowires can be uniformly distributed throughout the material matrix, forming a dense reinforcing network structure. This network structure can effectively block crack propagation, enhance the overall strength of the material, and fill any micropores or voids that may exist in the material, making the material structure more compact and effectively reducing defects in the material; at the same time, due to K2Ti6O 13 The nanoscale size and aspect ratio of nanowires endow them with good flexibility, which allows for favorable interactions with the matrix material. This enhances both strength and flexibility of the material. Furthermore, K2Ti6O... 13 The fibrous structure of nanowires can prevent the rapid propagation of cracks in materials. This crack-resistant effect can also significantly improve the fracture toughness of materials, making them less prone to brittle fracture even under external stress, thus enhancing their flexibility; in addition, K2Ti6O 13 The introduction of nanowires can also improve the thermal insulation performance of high-strength multilayer thermal insulation materials, K2Ti6O 13 The fibrous structure of nanowires can form complex three-dimensional networks within materials, effectively hindering heat conduction paths. This network structure restricts heat conduction within the material, thereby improving its thermal insulation performance. Furthermore, K₂Ti₆O 13 Nanowires have a certain blocking effect on infrared radiation, reducing infrared radiation, lowering the thermal conductivity of insulation materials, and effectively enhancing the insulation performance of materials.

[0042] According to some preferred embodiments, the potassium hexatitanate K2Ti6O 13The mass ratio of nanowires to alumina nanosheets is 1:(1-2) (e.g., 1:1, 1:1.5, or 1:2); in this invention, it is preferred that the potassium hexatite K2Ti6O 13 The mass ratio of nanowires to alumina nanosheets is 1:(1-2). This invention discovers that potassium hexatitanate (K₂Ti₆O₅) 13 Nanowires possess a large surface area and reinforcing effect in materials, but their addition amount needs to be controlled within a reasonable range to avoid K2Ti6O 13 The aggregation of nanowires affects the uniform dispersion and overall properties of the material. For example, K₂Ti₆O₂... 13 If too little nanowire is used, the reinforcing effect may be insignificant, failing to effectively improve the material's strength, flexibility, and thermal insulation properties. However, if K2Ti6O... 13 Excessive use of nanowires may lead to K2Ti6O 13 The difficulty in dispersing nanowires affects the uniformity of the material, increases the processing difficulty, and impacts the overall performance of the material.

[0043] In a second aspect, the present invention provides a high-strength multilayer thermal insulation material prepared by the preparation method described in the first aspect of the present invention.

[0044] The present invention will be further described below by way of examples, but the scope of protection of the present invention is not limited to these embodiments. The present invention may have many other embodiments, and those skilled in the art can make various corresponding changes and modifications based on the present invention without departing from its spirit and essence; however, all such corresponding changes and modifications should fall within the scope of protection of the appended claims.

[0045] Example 1

[0046] ① A uniformly dispersed system was obtained by stirring and dispersing 1 part phenolic fiber (diameter 200-500 nm), 19 parts zirconium oxide fiber (1-3 μm), 1 part alumina nanosheets, and 9 parts aluminum dihydrogen phosphate solution (the aluminum dihydrogen phosphate solution contains 30% aluminum dihydrogen phosphate by mass) in water at a speed of 4000 r / min for 35 min; the total mass percentage of phenolic fiber, zirconium oxide fiber, alumina nanosheets, and aluminum dihydrogen phosphate in the dispersion system was 15%.

[0047] ② A porous phenolic fiber cloth with a thickness of 10 μm and a pore size of 2 μm (the porosity of the porous phenolic fiber cloth is 60%) is laid flat in a papermaking equipment as a filter medium. Then, the dispersion system obtained in step ① is papermade through the papermaking equipment with the porous phenolic fiber cloth laid flat to obtain a preform. The preform includes the porous phenolic fiber cloth and the papermaking material obtained on the porous phenolic fiber cloth.

[0048] ③ The 20-layer prefabricated body is laid layer by layer in a hot press mold with an internal space of 20mm thickness (the thickness of each prefabricated body is 1mm after the hot press mold is closed and pressed). It is shaped and dried at 200℃ for 24h, and then placed in an inert atmosphere furnace and carbonized at 500℃ for 20h in an inert atmosphere (argon) to obtain a high-strength multilayer heat insulation material.

[0049] Example 2

[0050] ① Disperse 3 parts of phenolic fiber (500-1000 nm in diameter), 17 parts of zirconium oxide fiber (3-8 μm), 2 parts of alumina nanosheets, and 8 parts of aluminum dihydrogen phosphate solution (the aluminum dihydrogen phosphate solution contains 30% aluminum dihydrogen phosphate by mass) in water at a speed of 4000 r / min for 35 min to obtain a uniformly dispersed system; the total mass percentage of phenolic fiber, zirconium oxide fiber, alumina nanosheets, and aluminum dihydrogen phosphate in the dispersion system is 15%.

[0051] ② A porous phenolic fiber cloth with a thickness of 10 μm and a pore size of 500 nm (the porosity of the porous phenolic fiber cloth is 60%) is laid flat in a papermaking equipment as a filter medium. Then, the dispersion system obtained in step ① is papermade through the papermaking equipment with the porous phenolic fiber cloth laid flat to obtain a preform. The preform includes the porous phenolic fiber cloth and the papermaking material obtained on the porous phenolic fiber cloth.

[0052] ③ The 40-layer prefabricated body is laid layer by layer in a hot press mold with an internal space of 20mm thickness (the thickness of each prefabricated body is 0.5mm after the hot press mold is closed and pressed). It is shaped and dried at 240℃ for 24h, and then placed in an inert atmosphere furnace and carbonized at 900℃ for 10h in an inert atmosphere (argon) to obtain a high-strength multilayer heat insulation material.

[0053] Example 3

[0054] ① Four parts of phenolic fiber (500-1000 nm in diameter), 16 parts of zirconium oxide fiber (5-10 μm), four parts of alumina nanosheets, and one part of aluminum dihydrogen phosphate solution (the aluminum dihydrogen phosphate solution contains 30% aluminum dihydrogen phosphate by mass) were stirred and dispersed in water at a speed of 4000 r / min for 35 min to obtain a uniformly dispersed system; the total mass percentage of phenolic fiber, zirconium oxide fiber, alumina nanosheets, and aluminum dihydrogen phosphate in the dispersion system was 15%.

[0055] ② A porous phenolic fiber cloth with a thickness of 10 μm and a pore size of 1 μm (the porosity of the porous phenolic fiber cloth is 60%) is laid flat in a papermaking equipment as a filter medium. Then, the dispersion system obtained in step ① is papermade through the papermaking equipment with the porous phenolic fiber cloth laid flat to obtain a preform. The preform includes the porous phenolic fiber cloth and the papermaking material obtained on the porous phenolic fiber cloth.

[0056] ③ The 10-layer prefabricated body is laid layer by layer in a hot press mold with an internal space thickness of 20mm (the thickness of each prefabricated body is 2mm after the hot press mold is closed and pressed). It is shaped and dried at 300℃ for 24h, and then placed in an inert atmosphere furnace and carbonized at 900℃ for 10h in an inert atmosphere (argon) to obtain a high-strength multilayer thermal insulation material.

[0057] Example 4

[0058] ① Disperse 3 parts of phenolic fiber (diameter 300-800 nm), 17 parts of zirconium oxide fiber (3-8 μm), 2 parts of alumina nanosheets, and 8 parts of aluminum dihydrogen phosphate solution (the aluminum dihydrogen phosphate solution contains 30% aluminum dihydrogen phosphate by mass) in water at a speed of 4000 r / min for 35 min to obtain a uniformly dispersed system; the total mass percentage of phenolic fiber, zirconium oxide fiber, alumina nanosheets, and aluminum dihydrogen phosphate in the dispersion system is 15%.

[0059] ② A porous phenolic fiber cloth with a thickness of 10 μm and a pore size of 1 μm (the porosity of the porous phenolic fiber cloth is 60%) is laid flat in a papermaking equipment as a filter medium. Then, the dispersion system obtained in step ① is papermade through the papermaking equipment with the porous phenolic fiber cloth laid flat to obtain a preform. The preform includes the porous phenolic fiber cloth and the papermaking material obtained on the porous phenolic fiber cloth.

[0060] ③ The 20-layer prefabricated body is laid layer by layer in a hot press mold with an internal space thickness of 20mm (the thickness of each prefabricated body is 1mm after the hot press mold is closed and pressed). It is shaped and dried at 300℃ for 24h, and then placed in an inert atmosphere furnace and carbonized at 900℃ for 10h in an inert atmosphere (argon) to obtain a high-strength multilayer heat insulation material.

[0061] Example 5

[0062] Example 5 is basically the same as Example 4, except that:

[0063] ① Mix 3 parts phenolic fiber (diameter 300-800nm), 17 parts zirconium oxide fiber (3-8μm), and 1.5 parts potassium hexatitanate (K2Ti6O) with water. 13Nanowires, 2 parts alumina nanosheets, and 8 parts aluminum dihydrogen phosphate solution (the aluminum dihydrogen phosphate solution contains 30% aluminum dihydrogen phosphate by mass) were stirred and dispersed at 4000 r / min for 35 min to obtain a uniformly dispersed system; the dispersion system contains 15% by mass of phenolic fiber, zirconium oxide fiber, alumina nanosheets, and aluminum dihydrogen phosphate.

[0064] Example 6

[0065] Example 6 is basically the same as Example 4, except that:

[0066] ① Mix 3 parts phenolic fiber (diameter 300-800 nm), 17 parts zirconium oxide fiber (3-8 μm), and 3 parts potassium hexatitanate (K2Ti6O) with water. 13 Nanowires, 2 parts alumina nanosheets, and 8 parts aluminum dihydrogen phosphate solution (the aluminum dihydrogen phosphate solution contains 30% aluminum dihydrogen phosphate by mass) were stirred and dispersed at 4000 r / min for 35 min to obtain a uniformly dispersed system; the dispersion system contains 15% by mass of phenolic fiber, zirconium oxide fiber, alumina nanosheets, and aluminum dihydrogen phosphate.

[0067] Example 7

[0068] Example 7 is basically the same as Example 4, except that:

[0069] ① Mix 3 parts phenolic fiber (diameter 300-800 nm), 17 parts zirconium oxide fiber (3-8 μm), and 0.5 parts potassium hexatitanate (K₂Ti₆O) with water. 13 Nanowires, 2 parts alumina nanosheets, and 8 parts aluminum dihydrogen phosphate solution (the aluminum dihydrogen phosphate solution contains 30% aluminum dihydrogen phosphate by mass) were stirred and dispersed at 4000 r / min for 35 min to obtain a uniformly dispersed system; the dispersion system contains 15% by mass of phenolic fiber, zirconium oxide fiber, alumina nanosheets, and aluminum dihydrogen phosphate.

[0070] Example 8

[0071] Example 8 is basically the same as Example 4, except that:

[0072] ① A uniformly dispersed system was obtained by stirring and dispersing 3 parts of phenolic fiber (diameter 300-800 nm), 17 parts of zirconium oxide fiber (3-8 μm), 1.5 parts of titanium dioxide (TiO2) nanowires, 2 parts of alumina nanosheets, and 8 parts of aluminum dihydrogen phosphate solution (the aluminum dihydrogen phosphate solution contained 30% by mass) in water at a speed of 4000 r / min for 35 min. The total mass percentage of phenolic fiber, zirconium oxide fiber, alumina nanosheets, and aluminum dihydrogen phosphate in the dispersion system was 15%.

[0073] Comparative Example 1

[0074] ① Disperse 3 parts of phenolic fiber (diameter 300-800 nm), 17 parts of zirconium oxide fiber (3-8 μm), 2 parts of alumina nanosheets, and 8 parts of aluminum dihydrogen phosphate solution (the aluminum dihydrogen phosphate solution contains 30% aluminum dihydrogen phosphate by mass) in water at a speed of 4000 r / min for 35 min to obtain a uniformly dispersed system; the total mass percentage of phenolic fiber, zirconium oxide fiber, alumina nanosheets, and aluminum dihydrogen phosphate in the dispersion system is 15%.

[0075] ② A porous phenolic fiber cloth with a thickness of 1 mm and a pore size of 2 μm (the porosity of the porous phenolic fiber cloth is 60%) is laid flat in a papermaking equipment as a filter medium. Then, the dispersion system obtained in step ① is papermade through the papermaking equipment with the porous phenolic fiber cloth laid flat to obtain a preform. The preform includes the porous phenolic fiber cloth and the papermaking material obtained on the porous phenolic fiber cloth.

[0076] ③ The 10 layers of prefabricated material are laid one by one in a hot press mold with an internal space of 20 mm thickness (the thickness of each prefabricated material is 2 mm after the hot press mold is closed and pressed). The material is shaped and dried at 300℃ for 24 hours, and then placed in an inert atmosphere furnace and carbonized at 900℃ for 10 hours in an inert atmosphere (argon) to produce a multi-layer heat insulation material.

[0077] Comparative Example 2

[0078] ① Disperse 3 parts of phenolic fiber (diameter 300-800 nm), 17 parts of zirconium oxide fiber (3-8 μm), 2 parts of alumina nanosheets, and 8 parts of aluminum dihydrogen phosphate solution (the aluminum dihydrogen phosphate solution contains 30% aluminum dihydrogen phosphate by mass) in water at a speed of 4000 r / min for 35 min to obtain a uniformly dispersed system; the total mass percentage of phenolic fiber, zirconium oxide fiber, alumina nanosheets, and aluminum dihydrogen phosphate in the dispersion system is 15%.

[0079] ② A porous phenolic fiber cloth with a thickness of 10 μm and a pore size of 3 μm (the porosity of the porous phenolic fiber cloth is 60%) is laid flat in a papermaking equipment as a filter medium. Then, the dispersion system obtained in step ① is papermade through the papermaking equipment with the porous phenolic fiber cloth laid flat to obtain a preform. The preform includes the porous phenolic fiber cloth and the papermaking material obtained on the porous phenolic fiber cloth.

[0080] ③ Lay 20 layers of prefabricated material layer by layer in a hot press mold with an internal space of 20mm thickness (the thickness of each prefabricated material is 1mm after the hot press mold is closed and pressed), and shape and dry at 300℃ for 24h. Then place it in an inert atmosphere furnace and carbonize at 900℃ for 10h in an inert atmosphere (argon) to produce multi-layer heat insulation material.

[0081] Comparative Example 3

[0082] ① Disperse 20 parts of zirconia fiber (3-8 μm), 2 parts of alumina nanosheets, and 8 parts of aluminum dihydrogen phosphate solution (the aluminum dihydrogen phosphate solution contains 30% aluminum dihydrogen phosphate by mass) in water at a speed of 4000 r / min for 35 min to obtain a uniformly dispersed system; the total mass percentage of zirconia fiber, alumina nanosheets, and aluminum dihydrogen phosphate in the dispersion system is 15%.

[0083] ② A porous phenolic fiber cloth with a thickness of 10 μm and a pore size of 1 μm (the porosity of the porous phenolic fiber cloth is 60%) is laid flat in a papermaking equipment as a filter medium. Then, the dispersion system obtained in step ① is papermade through the papermaking equipment with the porous phenolic fiber cloth laid flat to obtain a preform. The preform includes the porous phenolic fiber cloth and the papermaking material obtained on the porous phenolic fiber cloth.

[0084] ③ Lay 20 layers of prefabricated material layer by layer in a hot press mold with an internal space of 20mm thickness (the thickness of each prefabricated material is 1mm after the hot press mold is closed and pressed), and shape and dry at 300℃ for 24h. Then place it in an inert atmosphere furnace and carbonize at 900℃ for 10h in an inert atmosphere (argon) to produce multi-layer heat insulation material.

[0085] Comparative Example 4

[0086] ① Disperse 20 parts of zirconia fiber (3-8 μm) and 10 parts of aluminum dihydrogen phosphate solution (the aluminum dihydrogen phosphate solution contains 30% aluminum dihydrogen phosphate by mass) in water at a speed of 4000 r / min for 35 min to obtain a uniformly dispersed system; the total mass percentage of zirconia fiber and aluminum dihydrogen phosphate in the dispersion system is 15%.

[0087] ② A porous phenolic fiber cloth with a thickness of 10 μm and a pore size of 1 μm (the porosity of the porous phenolic fiber cloth is 60%) is laid flat in a papermaking equipment as a filter medium. Then, the dispersion system obtained in step ① is papermade through the papermaking equipment with the porous phenolic fiber cloth laid flat to obtain a preform. The preform includes the porous phenolic fiber cloth and the papermaking material obtained on the porous phenolic fiber cloth.

[0088] ③ Lay 20 layers of prefabricated material layer by layer in a hot press mold with an internal space of 20mm thickness (the thickness of each prefabricated material is 1mm after the hot press mold is closed and pressed), and shape and dry at 300℃ for 24h. Then place it in an inert atmosphere furnace and carbonize at 900℃ for 10h in an inert atmosphere (argon) to produce multi-layer heat insulation material.

[0089] Comparative Example 5

[0090] ① Disperse 20 parts of zirconia fiber (3-8 μm) and 10 parts of aluminum dihydrogen phosphate solution (the aluminum dihydrogen phosphate solution contains 30% aluminum dihydrogen phosphate by mass) in water at a speed of 4000 r / min for 35 min to obtain a uniformly dispersed system; the total mass percentage of zirconia fiber and aluminum dihydrogen phosphate in the dispersion system is 15%.

[0091] ② A porous phenolic fiber cloth with a thickness of 10 μm and a pore size of 1 μm (the porosity of the porous phenolic fiber cloth is 60%) is laid flat in a papermaking equipment as a filter medium. Then, the dispersion system obtained in step ① is papermade through the papermaking equipment with the porous phenolic fiber cloth laid flat to obtain a preform. The preform includes the porous phenolic fiber cloth and the papermaking material obtained on the porous phenolic fiber cloth.

[0092] ③ Lay 20 layers of prefabricated material one by one in a hot press mold with an internal space of 20mm thickness (the thickness of each prefabricated material is 1mm after the hot press mold is closed and pressed), and dry it at 300℃ for 24 hours to produce multi-layer heat insulation material.

[0093] Comparative Example 6

[0094] ① Disperse 20 parts of zirconia fiber (3-8 μm), 2 parts of alumina nanosheets, and 8 parts of aluminum dihydrogen phosphate solution (the aluminum dihydrogen phosphate solution contains 30% aluminum dihydrogen phosphate by mass) in water at a speed of 4000 r / min for 35 min to obtain a uniformly dispersed system; the total mass percentage of zirconia fiber, alumina nanosheets, and aluminum dihydrogen phosphate in the dispersion system is 15%.

[0095] ② The dispersion system obtained in step ① is formed using a papermaking equipment to obtain a wet fiber sheet with a thickness of 1 mm.

[0096] ③ Twenty-one reflective screens (carbon fiber cloth) and twenty fiber wet sheets are alternately arranged and molded under a pressure of 1 MPa for 60 minutes. Then, they are sent to a high-temperature oven at 120°C for 24 hours to cure at high temperature, thus producing a multi-layer heat insulation material. The thickness of each carbon fiber cloth is 0.1 mm. In the alternating arrangement, a fiber wet sheet is placed between every two carbon fiber cloths. The carbon fiber cloth and the fiber wet sheet are bonded together by an aluminum phosphate aqueous solution (the aluminum phosphate aqueous solution contains 20% aluminum phosphate by mass).

[0097] Comparative Example 7

[0098] Comparative Example 7 is basically the same as Example 4, except that:

[0099] ① Three parts of carbon fiber (diameter 300-800 nm), 17 parts of zirconia fiber (3-8 μm), 2 parts of alumina nanosheets, and 8 parts of aluminum dihydrogen phosphate solution (the aluminum dihydrogen phosphate solution contains 30% aluminum dihydrogen phosphate by mass) were stirred and dispersed in water at a speed of 4000 r / min for 35 min to obtain a uniformly dispersed system; the total mass percentage of carbon fiber, zirconia fiber, alumina nanosheets, and aluminum dihydrogen phosphate in the dispersion system was 15%.

[0100] The high-strength multilayer thermal insulation materials prepared in each embodiment and the multilayer thermal insulation materials prepared in each comparative example were tested for bending strength, compressive strength (5% deformation) and thermal conductivity at 300℃. The results are shown in Table 1. As can be seen from Table 1, the high-strength multilayer thermal insulation materials prepared in each embodiment of the present invention have high strength and excellent thermal insulation performance.

[0101] Table 1: Results of the mechanical and thermal properties of the high-strength multilayer thermal insulation materials prepared in each embodiment and the multilayer thermal insulation materials prepared in each comparative example.

[0102]

[0103] In the various embodiments and comparative examples of this invention, the term "parts" refers to "parts by weight," and the unit can be uniformly taken as "g" or "kg" or other weight units.

[0104] The parts of this invention not described in detail are techniques known to those skilled in the art.

[0105] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a high-strength multilayer thermal insulation material, characterized in that, The method includes the following steps: (1) Disperse phenolic fiber, zirconium oxide fiber, alumina nanosheets and phosphate solution evenly with water to obtain a dispersion system; (2) The porous phenolic fiber cloth is laid flat in the papermaking equipment as a filter medium, and then the dispersion system is papermade by the papermaking equipment with the porous phenolic fiber cloth laid flat to obtain a preform; the preform includes the porous phenolic fiber cloth and the papermaking material obtained on the porous phenolic fiber cloth; the pore size of the porous phenolic fiber cloth is 500nm~2μm; the thickness of the porous phenolic fiber cloth is 10~200μm; (3) The multi-layer prefabricated body is laid layer by layer in a shaping mold for shaping and drying, and then carbonized in an inert atmosphere to obtain a high-strength multi-layer thermal insulation material.

2. The preparation method according to claim 1, characterized in that, In step (1): The mass ratio of the zirconium oxide fiber to the phenolic fiber is (4~19):1; The mass ratio of the alumina nanosheets to the phosphate solution is (1~4):(1~9); and / or The phosphate solution is an aluminum dihydrogen phosphate solution, and the aluminum dihydrogen phosphate solution contains an aluminum dihydrogen phosphate mass fraction of 20-50%.

3. The preparation method according to claim 1, characterized in that, In step (1): The diameter of the zirconium oxide fiber is 1~10μm; and / or The diameter of the phenolic fiber is 200~1000nm.

4. The preparation method according to claim 1, characterized in that, In step (1): The dispersion rotation speed is 4000~10000 r / min, and the dispersion time is 3~40 min.

5. The preparation method according to claim 1, characterized in that: The thickness of a single layer of the prefabricated body is 0.5~2mm; and / or The thickness of the high-strength multilayer thermal insulation material is 15~25mm.

6. The preparation method according to claim 1, characterized in that, In step (3): The temperature for shaping and drying is 200℃~300℃.

7. The preparation method according to claim 1, characterized in that, In step (3): The carbonization temperature is 500~900℃, and the carbonization time is 10~20h.

8. The preparation method according to any one of claims 1 to 7, characterized in that, In step (1): Potassium hexatitanate (K₂Ti₆O) was also added to the dispersion system. 13 Nanowires.

9. The preparation method according to claim 8, characterized in that: The potassium hexatitanate K2Ti6O 13 The mass ratio of nanowires to alumina nanosheets is 1:(1~2).

10. A high-strength multilayer thermal insulation material prepared by any one of claims 1 to 9.

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