Nano-silicon composite thermal insulation material and preparation method therefor

Abstract

The present application relates to a nano-silicon composite thermal insulation material and a preparation method therefor. The nano-silicon composite thermal insulation material comprises a reinforcement mesh and thermal insulation layers arranged on two sides of the reinforcement mesh, the reinforcement mesh and the thermal insulation layers being bonded to each other by means of an inorganic binder. Raw materials for preparing the thermal insulation layers comprise the following components: 60-90 parts by weight of nano silicon, 15-35 parts by weight of an opacifying agent and 1-10 parts by weight of fibers. The preparation method comprises the following steps: accurately weighing the raw materials used for the thermal insulation layers, and uniformly mixing same; spreading the thermal insulation layer raw materials, spraying the inorganic binder and laying the reinforcement mesh, spraying the inorganic binder on the reinforcement mesh, and then laying a thermal insulation layer raw material layer again; and pressing-fitting same at 0.001-0.2 Mpa, and then raising the pressure to 1-5 Mpa at a rate of 0.1-0.3 Mpa / min to press-fit same, thus obtaining the nano-silicon composite thermal insulation material after molding. The thermal insulation material of the present application has the advantages of a low thermal conductivity coefficient, excellent thermal insulation performance, long-term resistance to high temperature and burn-through, a reducible thickness, a high tensile strength and high cost performance.

Description

Nano-silicon composite thermal insulation material and preparation method thereof Technical Field

[0001] The present application relates to the field of thermal insulation materials, and in particular to nano-silicon composite thermal insulation materials and preparation methods thereof. Background Art

[0002] Insulation panels, formed from a high-barrier film, a porous core material, and an adsorbent, have attracted widespread attention due to their ultra-low thermal conductivity. The core material, the core component, is primarily a mixture of glass fiber, chopped strands, silica, and a binder. Insulation panels with silica as the core have been widely researched and rapidly developed due to their low thermal conductivity, long service life, and environmental friendliness.

[0003] Common insulation panels are often made by bonding various raw materials with glue, such as pressure-sensitive adhesive, followed by pressing and drying. During the manufacturing process, the glue can easily clog pores in core materials, such as silica, reducing the insulation effectiveness of the core material and shortening the service life of the insulation panel. To address this issue, the present application provides a nano-silicon composite insulation material.

[0004] Summary of the Invention

[0005] In order to improve the thermal insulation effect and service life of the insulation board, the present application provides a nano-silicon composite thermal insulation material and a preparation method thereof.

[0006] In the first aspect, the nano-silicon composite thermal insulation material provided by the present application adopts the following technical solutions:

[0007] The nano-silicon composite thermal insulation material comprises a reinforcing mesh and thermal insulation layers arranged on both sides of the reinforcing mesh, wherein the reinforcing mesh and the thermal insulation layers are bonded by an inorganic adhesive;

[0008] The raw materials for preparing the heat insulation layer include the following components: 60-90 parts by weight of nano silicon, 15-35 parts by weight of sunscreen and 1-10 parts by weight of fiber.

[0009] By adopting the above technical solutions, nano-silicon has better fireproof and heat-insulating effects, and can effectively reduce heat conduction, heat radiation and heat convection in the material, giving the material better thermal insulation performance; the sunscreen in the material can reduce the radiation heat transfer of the material, block the path of infrared radiation, and achieve the purpose of blocking thermal radiation; the fiber has excellent thermal insulation performance, can effectively insulate in the material, and inhibit heat conduction. The pore size of nano-silicon is 20-50nm, which is smaller than the mean free path of air (69nm), so that the gas molecules in the pores cannot flow freely, basically losing the ability of macroscopic movement, inhibiting the thermal motion between gas molecules, and blocking thermal convection. Nano-silicon, sunscreen and fiber are compounded to give the thermal insulation material an excellent thermal insulation effect. At the same time, the use of a reinforcing mesh allows the material to maintain a specific shape and can also improve the material's strength in use. The use of an inorganic adhesive to bond the thermal insulation layer and the reinforcing mesh avoids the use of glue for bonding and clogging the pores in the material. The inorganic adhesive has excellent heat resistance and is not easily decomposed by heat during later use, which can ensure a stable connection between the thermal insulation layer and the reinforcing mesh. At the same time, the inorganic adhesive is bonded between the thermal insulation layer and the reinforcing mesh without clogging the pores of the nano-silicon and fibers in the thermal insulation layer, so that the thermal insulation layer can maintain a long-lasting and excellent thermal insulation effect, and the thermal insulation material has a longer service life.

[0010] In a specific embodiment, the inorganic binder is selected from one or more of sodium water glass, potassium water glass, lithium water glass, and nano-silicon resin.

[0011] By adopting the above technical solution, sodium water glass, potassium water glass and lithium water glass are a mixture of sodium silicate, potassium silicate and lithium silicate, which have good bonding properties, are resistant to high temperatures and have high stability, and can effectively bond the thermal insulation layer and the reinforcement layer; nano silicone resin is resistant to high temperatures and also has excellent corrosion resistance and weather resistance, and can effectively bond the thermal insulation layer and the reinforcement mesh at high temperatures, reducing the possibility of separation between the thermal insulation layer and the reinforcement mesh and affecting the thermal insulation effect of the thermal insulation material.

[0012] In a specific embodiment, the nano-silicon is fumed silica or silica aerogel; the reinforcing mesh is glass fiber mesh, high silica fiber mesh, basalt fiber mesh, ceramic fiber mesh, pre-oxidized silk fiber mesh, carbon fiber mesh or metal mesh.

[0013] In a specific embodiment, the metal mesh is made of stainless steel, aluminum alloy or copper substrate, and has a mesh size of 2-30 meshes, preferably 5-15 meshes, and can specifically be 2 mesh, 3 mesh, 5 mesh, 13 mesh, 15 mesh, 20 mesh, 25 mesh or 30 mesh.

[0014] By adopting the above technical solution, fumed silica has a higher specific surface area and porosity, and can form a microscopic pore structure in the material, effectively blocking heat transfer, improving the thermal insulation effect of the material, reducing heat absorption, and further improving the thermal insulation performance of the material; silica aerogel has a higher porosity and lower thermal conductivity coefficient, and high strength, so that the thermal insulation material can maintain excellent thermal insulation performance while also maintaining better shape stability.

[0015] As a mesh structure, glass fiber mesh has good tensile strength, which can improve the strength of the thermal insulation material, and can also give the thermal insulation material a certain degree of impact resistance and corrosion resistance; high silica fiber has excellent high strength, high temperature resistance, heat insulation and thermal insulation properties. Choosing high silica fiber mesh as a reinforcing mesh can improve the strength of the thermal insulation material while also improving the thermal insulation effect of the thermal insulation material; metal mesh has high mechanical strength and compressive strength, which can effectively improve the use strength of the thermal insulation material.

[0016] In a specific embodiment, the bulk density of the fumed silica is 20-100 g / m 3 .

[0017] By adopting the above technical solution, the bulk density of fumed silica affects its thermal insulation efficiency. The smaller the bulk density, the lower the thermal conductivity of the fumed silica and the better the thermal insulation effect. However, if the bulk density is too low, the fumed silica will be too light and easily float, which will affect the quality of the finished product when preparing the thermal insulation material.

[0018] In a specific embodiment, the sunscreen is selected from one or more of silicon carbide, carbon black, zirconium oxide, graphite or graphene, and has a particle size of 0.01-15 μm.

[0019] By adopting the above technical solutions, silicon carbide can significantly reduce infrared radiation heat transfer and effectively improve the high-temperature thermal insulation performance of the material; carbon black, as a black inorganic pigment, has strong covering power and a large specific surface area, which can effectively improve the light shading and absorption effects to achieve the purpose of thermal insulation; zirconium oxide has excellent high-temperature resistance and a high refractive index, which can effectively improve the thermal insulation effect of the material; graphite and graphene have a large specific surface area, which can effectively absorb infrared radiation and reduce the heat conduction of the material, thereby making the thermal insulation material have excellent thermal insulation performance.

[0020] In a specific embodiment, the particle size of the silicon carbide is 3-5 μm.

[0021] By adopting the above technical solution, the smaller the silicon carbide particle size, the larger the surface area. Smaller silicon carbide has more interfaces to hinder heat conduction. At the same time, it can be evenly distributed in the material, reducing the pores and air in the material, thereby improving the thermal insulation performance. However, too small a particle size will lead to increased production costs and unstable quality of the finished product. Therefore, by limiting the particle size of silicon carbide, it can stably exert its thermal insulation performance.

[0022] In a specific embodiment, the fiber is selected from one or more of glass fiber, high silica fiber, and carbon fiber, and the fiber has a diameter of 3-15 μm and a length of 5-20 mm.

[0023] By adopting the above technical solution, the smaller the fiber diameter, the smaller the internal pores, and the more tortuous the heat transfer path, thereby improving the thermal insulation effect of the material; the shorter the fiber, the easier it is to disperse in the material, but it is prone to breakage, folding and aging under high temperature conditions, which will affect the high temperature resistance. The longer the fiber, the higher the tensile strength and modulus of the fiber, which can maintain good strength and stability at high temperatures. However, the longer the length, the less likely the fiber is to disperse in the material and the more likely it is to agglomerate. The fiber may even extend out of the material system, which can easily cause the fiber to be pulled out, thereby reducing the stability of subsequent use. By limiting the diameter and length of the fiber, the fiber can be stably present in the material system and can exert a good thermal insulation effect.

[0024] In a specific embodiment, the fibers include glass fiber, high silica fiber and carbon fiber, and the weight ratio of the three is (1-2): (2-3):1.

[0025] By adopting the above technical solutions, glass fiber, high-silica fiber and carbon fiber all have excellent high-temperature resistance. However, the tensile strength of glass fiber is lower than that of carbon fiber, it is more brittle and has lower wear resistance. However, glass fiber has excellent heat resistance, is lightweight and has lower cost. The mechanical properties and chemical stability of carbon fiber are easily affected by high temperatures, and high temperatures will accelerate the oxidation and failure process of carbon fiber. Compared with glass fiber, high-silica fiber has better heat resistance, wear resistance and chemical corrosion resistance, while glass fiber has better strength, flexibility and insulation. Therefore, by compounding the above three fibers in a specific ratio, the performance of the thermal insulation material can be improved.

[0026] In a specific embodiment, the carbon fiber surface is coated with a polyamic acid coating, and the specific preparation method is as follows:

[0027] Dissolve pyromellitic dianhydride and diaminodiphenyl ether in N,N-dimethylamide and react under nitrogen protection. Then adjust the pH to 9 with ammonia water, impregnate carbon fiber, and then dry and disperse to obtain carbon fiber coated with polyamic acid.

[0028] By adopting the above technical solution, carbon fibers are prone to oxidation and failure at high temperatures. By coating the surface of the carbon fibers with a polyamic acid coating, the polyamic acid coating containing heat-resistant amide groups improves the thermal stability of the carbon fibers, slowing down the oxidation and failure process of the carbon fibers, and making the thermal insulation material have a long-lasting thermal insulation effect. In addition, the surface of the fumed silica is insufficiently coordinated, has a large specific surface area, and is oxygen-deficient. When preparing the thermal insulation material, a bonding effect can be formed between the fumed silica and the carbon fibers, reducing the occurrence of powder loss and easy splitting of the thermal insulation layer, and making the thermal insulation layer have a long-lasting thermal insulation effect.

[0029] In a specific embodiment, the thickness of the thermal insulation material is 0.3-2 mm, specifically 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 1 mm, 1.2 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.8 mm, or 2 mm.

[0030] In a specific embodiment, a flame retardant resin layer is provided on the surface of the heat insulation layer.

[0031] In a specific embodiment, the coating thickness of the flame retardant resin layer is 20-100 μm, specifically 20 μm, 30 μm, 50 μm, 70 μm, 90 μm, or 100 μm.

[0032] By adopting the above technical solution, coating the flame retardant resin layer on the surface of the thermal insulation layer can play a packaging role, further reduce the occurrence of powder loss, and at the same time play a certain flame retardant role.

[0033] In a second aspect, the present application provides a method for preparing a nano-silicon composite thermal insulation material, which adopts the following technical solution:

[0034] The preparation method of nano-silicon composite thermal insulation material comprises the following steps:

[0035] Accurately weigh the raw materials for the thermal insulation layer and mix them evenly;

[0036] Lay the insulation material flat, spray the inorganic binder, lay the reinforcement mesh, spray the inorganic binder on the reinforcement mesh, and then lay another layer of insulation material;

[0037] The process is firstly pressed at 0.001-0.2Mpa, and then the pressure is increased to 1-5Mpa at a speed of 0.1-0.3Mpa / min to press, and the nano-silicon composite heat insulation material is obtained after molding.

[0038] By adopting the above technical solution, the thermal insulation layer is formed by lamination, eliminating the use of glue. During the lamination process, low pressure is applied first to initially expel air from the material, and then higher pressure is applied to further expel any remaining air and finalize the thermal insulation layer. This method reduces the risk of air not being able to escape quickly enough during one-time high pressure lamination, which can lead to the formation of pores in the material, which can reduce the thermal insulation performance of the material.

[0039] In summary, this application includes at least one of the following beneficial technical effects:

[0040] This application utilizes nano-silicon, sunscreen and fiber to give the insulation material excellent thermal insulation properties, and at the same time uses a reinforcing mesh to ensure that the insulation material has better use strength. The insulation layer and the reinforcing mesh are bonded with an inorganic adhesive, avoiding the use of glue and retaining the natural pores of nano-silicon, so that its thermal insulation effect can be effectively exerted, thereby making the insulation material have the advantages of high thermal insulation and high strength.

[0041] This application selects fibers of specific diameter and length so that they can exist stably in the system and can be effectively combined with sunscreen and nano-silicon to form an insulation layer, so that the insulation material has better insulation effect and longer service life.

[0042] When preparing the thermal insulation material, the present application adopts a step-by-step pressing method to press and form. First, a lower pressure is used to expel the air contained in the material, and then a higher pressure is used to press and form it, so that the raw materials in the thermal insulation material can be closely connected, reducing the appearance of pores, and effectively ensuring the thermal insulation performance of the thermal insulation material. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] FIG1 is a schematic diagram of the test results of the sample in Example 2;

[0044] FIG2 is a comparison chart of the test results of the samples in Example 2, Comparative Example 1 and Comparative Example 2;

[0045] FIG3 is a schematic diagram of the test results of the samples in Example 4;

[0046] FIG4 is a schematic diagram of the test results of the sample in Example 38;

[0047] Figure 5 is a comparison chart of the test results of the samples in Example 4, Example 38, Comparative Example 1, Comparative Example 3 and Comparative Example 4. DETAILED DESCRIPTION

[0048] The present application is further described in detail below with reference to the embodiments.

[0049] Preparation Example 1

[0050] Pyromellitic dianhydride and diaminodiphenyl ether were dissolved in N,N-dimethylformamide at a molar ratio of 1:1 and reacted at 5°C under nitrogen for 2 hours to prepare a polyamic acid solution with a polyamic acid mass fraction of 10%. Ammonia water was then added to adjust the solution pH to 9, and excess ammonia water was removed under ventilation. Deionized water was then added to the solution to prepare a polyamic acid aqueous solution with a mass fraction of 0.5%. Carbon fibers were immersed in the polyamic acid aqueous solution and then dried and dispersed to obtain carbon fibers coated with a polyamic acid coating.

[0051] Example 1

[0052] Nano-silicon composite thermal insulation material includes a reinforcing mesh and thermal insulation layers arranged on both sides of the reinforcing mesh. The reinforcing mesh is a glass fiber mesh with a gram weight of 30g / square meter. The thermal insulation layer includes 60g of fumed silica, 15g of silicon carbide and 1g of high-silica fiber. The bulk density of the fumed silica is 50g / cubic meter, the particle size of the silicon carbide is 3μm, and the diameter of the high-silica fiber is 8μm and the length is 10mm.

[0053] During preparation, fumed silica, silicon carbide and high silica fiber are accurately weighed and fully dispersed to obtain the materials;

[0054] Take two portions of material, 30g each;

[0055] Spread 30g of material on a 310mm*310mm square fixture, vibrate and flatten it, and spray a sodium water glass solution with a modulus of 3 on the surface of the material at a spraying amount of 40g / m2;

[0056] Lay a glass fiber mesh on the material, spray a sodium water glass solution on the surface of the glass fiber mesh at a spraying amount of 40g / square meter, and then lay another 30g material flat;

[0057] A layer of release film is laid on the surface of the laid material, which is then placed in a pressing machine and pressed for 60 seconds under vacuum conditions at a pressure of 0.1 MPa. The pressure is then increased to 2 MPa at a rate of 0.2 MPa / min and maintained for 120 seconds. The mold is opened to obtain a nano-silicon composite thermal insulation material with a thickness of 2 mm.

[0058] Example 2

[0059] Nano-silicon composite thermal insulation material includes a reinforcing mesh and thermal insulation layers arranged on both sides of the reinforcing mesh. The reinforcing mesh is a glass fiber mesh with a gram weight of 30g / square meter. The thermal insulation layer includes 70g of fumed silica, 30g of silicon carbide and 5g of high-silica fiber. The bulk density of the fumed silica is 50g / cubic meter, the particle size of the silicon carbide is 3μm, and the diameter of the high-silica fiber is 8μm and the length is 10mm.

[0060] During preparation, fumed silica, silicon carbide and high silica fiber are accurately weighed and fully dispersed to obtain the materials;

[0061] Take two portions of material, 30g each;

[0062] Spread 30g of material on a 310mm*310mm square fixture, vibrate and flatten it, and spray a sodium water glass solution with a modulus of 3 on the surface of the material at a spraying amount of 40g / m2;

[0063] Lay a glass fiber mesh on the material, spray a sodium water glass solution on the surface of the glass fiber mesh at a spraying amount of 40g / square meter, and then lay another 30g material flat;

[0064] A layer of release film is laid on the surface of the laid material, which is then placed in a pressing machine and pressed for 60 seconds under vacuum conditions at a pressure of 0.1 MPa. The pressure is then increased to 2 MPa at a rate of 0.2 MPa / min and maintained for 120 seconds. The mold is opened to obtain a nano-silicon composite thermal insulation material with a thickness of 2 mm.

[0065] Example 3

[0066] Nano-silicon composite thermal insulation material includes a reinforcing mesh and thermal insulation layers arranged on both sides of the reinforcing mesh. The reinforcing mesh is a glass fiber mesh with a gram weight of 30g / square meter. The thermal insulation layer includes 90g of fumed silica, 35g of silicon carbide and 10g of high-silica fiber. The bulk density of the fumed silica is 50g / cubic meter, the particle size of the silicon carbide is 3μm, and the diameter of the high-silica fiber is 8μm and the length is 10mm.

[0067] During preparation, fumed silica, silicon carbide and high silica fiber are accurately weighed and fully dispersed to obtain the materials;

[0068] Take two portions of material, 30g each;

[0069] Spread 30g of material on a 310mm*310mm square fixture, vibrate and flatten it, and spray a sodium water glass solution with a modulus of 3 on the surface of the material at a spraying amount of 40g / m2;

[0070] Lay a glass fiber mesh on the material, spray a sodium water glass solution on the surface of the glass fiber mesh at a spraying amount of 40g / square meter, and then lay another 30g material flat;

[0071] A layer of release film is laid on the surface of the laid material, which is then placed in a pressing machine and pressed for 60 seconds under vacuum conditions at a pressure of 0.1 MPa. The pressure is then increased to 2 MPa at a rate of 0.2 MPa / min and maintained for 120 seconds. The mold is opened to obtain a nano-silicon composite thermal insulation material with a thickness of 2 mm.

[0072] Example 4-Example 7

[0073] Compared with Example 2, the differences between Examples 4 to 7 are only in the amount of materials used and the thickness of the finished products, as follows:

[0074] In Example 4, two portions of material were taken, each 22 g, and the thickness of the obtained finished product was 1.4 mm;

[0075] In Example 5, two portions of material were taken, each 10 g, and the thickness of the obtained finished product was 0.7 mm;

[0076] In Example 6, two portions of material were taken, each 9 g, and the thickness of the obtained finished product was 0.6 mm;

[0077] In Example 7, two portions of material were taken, each weighing 6 g, and the thickness of the obtained finished product was 0.4 mm.

[0078] Example 8-Example 11

[0079] Compared with Example 2, the difference between Examples 8 to 11 is only that the bulk density of the fumed silica used is different, specifically:

[0080] The bulk density of the fumed silica in Example 8 is 20 g / m3;

[0081] The bulk density of the fumed silica in Example 9 is 100 g / m3;

[0082] The bulk density of the fumed silica in Example 10 is 5 g / m3;

[0083] The bulk density of the fumed silica in Example 11 is 200 g / m3.

[0084] Example 12

[0085] Nano-silicon composite thermal insulation material includes a reinforcing mesh and thermal insulation layers arranged on both sides of the reinforcing mesh. The reinforcing mesh is a glass fiber mesh with a gram weight of 30g / square meter. The thermal insulation layer includes 70g of silicon aerogel, 30g of silicon carbide and 5g of high-silica fiber. The particle size of silicon carbide is 3μm, and the diameter of the high-silica fiber is 8μm and the length is 10mm.

[0086] During preparation, fumed silica, silicon carbide and high silica fiber are accurately weighed and fully dispersed to obtain the materials;

[0087] Take two portions of material, 30g each;

[0088] Spread 30g of material on a 310mm*310mm square fixture, vibrate and flatten it, and spray a sodium water glass solution with a modulus of 3 on the surface of the material at a spraying amount of 40g / m2;

[0089] Lay a glass fiber mesh on the material, spray a sodium water glass solution on the surface of the glass fiber mesh at a spraying amount of 40g / square meter, and then lay another 30g material flat;

[0090] A layer of release film is laid on the surface of the laid material, which is then placed in a pressing machine and pressed for 60 seconds under vacuum conditions at a pressure of 0.1 MPa. The pressure is then increased to 2 MPa at a rate of 0.2 MPa / min and maintained for 120 seconds. The mold is opened to obtain a nano-silicon composite thermal insulation material with a thickness of 2 mm.

[0091] Example 13-Example 17

[0092] Compared with Example 2, the difference between Examples 13 to 17 is only the particle size of silicon carbide, specifically:

[0093] The particle size of silicon carbide in Example 13 is 0.01 μm;

[0094] The particle size of silicon carbide in Example 14 is 5 μm;

[0095] The particle size of silicon carbide in Example 15 is 10 μm;

[0096] The particle size of silicon carbide in Example 16 is 15 μm;

[0097] The particle size of silicon carbide in Example 17 is 30 μm.

[0098] Example 18-Example 25

[0099] Compared with Example 2, the difference between Examples 18 to 25 is only the specifications of the high-silica fiber, specifically:

[0100] In Example 18, the diameter of the high silica fiber is 1 μm;

[0101] In Example 19, the diameter of the high silica fiber is 3 μm;

[0102] In Example 20, the diameter of the high silica fiber is 15 μm;

[0103] The diameter of the high silica fiber in Example 21 is 30 μm;

[0104] The length of the high silica fiber in Example 22 is 1 mm;

[0105] The length of the high silica fiber in Example 23 is 5 mm;

[0106] The length of the high silica fiber in Example 24 is 20 mm;

[0107] The length of the high silica fiber in Example 25 is 35 mm.

[0108] Example 26

[0109] Nano-silicon composite thermal insulation material includes a reinforcing mesh and thermal insulation layers arranged on both sides of the reinforcing mesh. The reinforcing mesh is a glass fiber mesh with a gram weight of 30g / square meter. The thermal insulation layer includes 70g of fumed silica, 30g of silicon carbide and 5g of glass fiber. The bulk density of the fumed silica is 50g / cubic meter, the particle size of the silicon carbide is 3μm, and the diameter of the glass fiber is 8μm and the length is 10mm.

[0110] During preparation, fumed silica, silicon carbide and glass fiber are accurately weighed and fully dispersed to obtain the materials;

[0111] Take two portions of material, 30g each;

[0112] Spread 30g of material on a 310mm*310mm square fixture, vibrate and flatten it, and spray a sodium water glass solution with a modulus of 3 on the surface of the material at a spraying amount of 40g / m2;

[0113] Lay a glass fiber mesh on the material, spray a sodium water glass solution on the surface of the glass fiber mesh at a spraying amount of 40g / square meter, and then lay another 30g material flat;

[0114] A layer of release film is laid on the surface of the laid material, which is then placed in a pressing machine and pressed for 60 seconds under vacuum conditions at a pressure of 0.1 MPa. The pressure is then increased to 2 MPa at a rate of 0.2 MPa / min and maintained for 120 seconds. The mold is opened to obtain a nano-silicon composite thermal insulation material with a thickness of 2 mm.

[0115] Example 27

[0116] Nano-silicon composite thermal insulation material includes a reinforcing mesh and thermal insulation layers arranged on both sides of the reinforcing mesh. The reinforcing mesh is a glass fiber mesh with a gram weight of 30g / square meter. The thermal insulation layer includes 70g of fumed silica, 30g of silicon carbide and 5g of carbon fiber. The bulk density of the fumed silica is 50g / cubic meter, the particle size of the silicon carbide is 3μm, and the diameter of the carbon fiber is 8μm and the length is 10mm.

[0117] During preparation, fumed silica, silicon carbide and carbon fiber are accurately weighed and fully dispersed to obtain the materials;

[0118] Take two portions of material, 30g each;

[0119] Spread 30g of material on a 310mm*310mm square fixture, vibrate and flatten it, and spray a sodium water glass solution with a modulus of 3 on the surface of the material at a spraying amount of 40g / m2;

[0120] Lay a glass fiber mesh on the material, spray a sodium water glass solution on the surface of the glass fiber mesh at a spraying amount of 40g / square meter, and then lay another 30g material flat;

[0121] A layer of release film is laid on the surface of the laid material, which is then placed in a pressing machine and pressed for 60 seconds under vacuum conditions at a pressure of 0.1 MPa. The pressure is then increased to 2 MPa at a rate of 0.2 MPa / min and maintained for 120 seconds. The mold is opened to obtain a nano-silicon composite thermal insulation material with a thickness of 2 mm.

[0122] Example 28

[0123] Nano-silicon composite thermal insulation material includes a reinforcing mesh and thermal insulation layers arranged on both sides of the reinforcing mesh. The reinforcing mesh is a glass fiber mesh with a gram weight of 30g / square meter. The thermal insulation layer includes 70g of fumed silica, 30g of silicon carbide and 5g of fiber. The bulk density of the fumed silica is 50g / cubic meter, the particle size of the silicon carbide is 3μm, and the fiber is composed of glass fiber and high silica fiber with a mass ratio of 1:2. The fiber has a diameter of 8μm and a length of 10mm.

[0124] During preparation, fumed silica, silicon carbide, glass fiber and high silica fiber are accurately weighed and fully dispersed to obtain the materials;

[0125] Take two portions of material, 30g each;

[0126] Spread 30g of material on a 310mm*310mm square fixture, vibrate and flatten it, and spray a sodium water glass solution with a modulus of 3 on the surface of the material at a spraying amount of 40g / m2;

[0127] Lay a glass fiber mesh on the material, spray a sodium water glass solution on the surface of the glass fiber mesh at a spraying amount of 40g / square meter, and then lay another 30g material flat;

[0128] A layer of release film is laid on the surface of the laid material, which is then placed in a pressing machine and pressed for 60 seconds under vacuum conditions at a pressure of 0.1 MPa. The pressure is then increased to 2 MPa at a rate of 0.2 MPa / min and maintained for 120 seconds. The mold is opened to obtain a nano-silicon composite thermal insulation material with a thickness of 2 mm.

[0129] Example 29

[0130] Nano-silicon composite thermal insulation material includes a reinforcing mesh and thermal insulation layers arranged on both sides of the reinforcing mesh. The reinforcing mesh is a glass fiber mesh with a gram weight of 30g / square meter. The thermal insulation layer includes 70g of fumed silica, 30g of silicon carbide and 5g of fiber. The bulk density of the fumed silica is 50g / cubic meter, the particle size of the silicon carbide is 3μm, and the fiber is composed of high-silica fiber and carbon fiber with a mass ratio of 2:1. The fiber has a diameter of 8μm and a length of 10mm.

[0131] During preparation, fumed silica, silicon carbide, high silica fiber and carbon fiber are accurately weighed and fully dispersed to obtain the materials;

[0132] Take two portions of material, 30g each;

[0133] Spread 30g of material on a 310mm*310mm square fixture, vibrate and flatten it, and spray a sodium water glass solution with a modulus of 3 on the surface of the material at a spraying amount of 40g / m2;

[0134] Lay a glass fiber mesh on the material, spray a sodium water glass solution on the surface of the glass fiber mesh at a spraying amount of 40g / square meter, and then lay another 30g material flat;

[0135] A layer of release film is laid on the surface of the laid material, which is then placed in a pressing machine and pressed for 60 seconds under vacuum conditions at a pressure of 0.1 MPa. The pressure is then increased to 2 MPa at a rate of 0.2 MPa / min and maintained for 120 seconds. The mold is opened to obtain a nano-silicon composite thermal insulation material with a thickness of 2 mm.

[0136] Example 30

[0137] Nano-silicon composite thermal insulation material includes a reinforcing mesh and thermal insulation layers arranged on both sides of the reinforcing mesh. The reinforcing mesh is a glass fiber mesh with a gram weight of 30g / square meter. The thermal insulation layer includes 70g of fumed silica, 30g of silicon carbide and 5g of fiber. The bulk density of the fumed silica is 50g / cubic meter, the particle size of the silicon carbide is 3μm, and the fiber is composed of glass fiber, high silica fiber and carbon fiber in a mass ratio of 1:2:1. The fiber has a diameter of 8μm and a length of 10mm.

[0138] During preparation, fumed silica, silicon carbide, glass fiber, high silica fiber and carbon fiber are accurately weighed and fully dispersed to obtain the materials;

[0139] Take two portions of material, 30g each;

[0140] Spread 30g of material on a 310mm*310mm square fixture, vibrate and flatten it, and spray a sodium water glass solution with a modulus of 3 on the surface of the material at a spraying amount of 40g / m2;

[0141] Lay a glass fiber mesh on the material, spray a sodium water glass solution on the surface of the glass fiber mesh at a spraying amount of 40g / square meter, and then lay another 30g material flat;

[0142] A layer of release film is laid on the surface of the laid material, which is then placed in a pressing machine and pressed for 60 seconds under vacuum conditions at a pressure of 0.1 MPa. The pressure is then increased to 2 MPa at a rate of 0.2 MPa / min and maintained for 120 seconds. The mold is opened to obtain a nano-silicon composite thermal insulation material with a thickness of 2 mm.

[0143] Example 31

[0144] Nano-silicon composite thermal insulation material includes a reinforcing mesh and thermal insulation layers arranged on both sides of the reinforcing mesh. The reinforcing mesh is a glass fiber mesh with a gram weight of 30g / square meter. The thermal insulation layer includes 70g of fumed silica, 30g of silicon carbide and 5g of fiber. The bulk density of the fumed silica is 50g / cubic meter, the particle size of the silicon carbide is 3μm, and the fiber is composed of glass fiber, high silica fiber and carbon fiber in a mass ratio of 2:3:1. The fiber has a diameter of 8μm and a length of 10mm.

[0145] During preparation, fumed silica, silicon carbide, glass fiber, high silica fiber and carbon fiber are accurately weighed and fully dispersed to obtain the materials;

[0146] Take two portions of material, 30g each;

[0147] Spread 30g of material on a 310mm*310mm square fixture, vibrate and flatten it, and spray a sodium water glass solution with a modulus of 3 on the surface of the material at a spraying amount of 40g / m2;

[0148] Lay a glass fiber mesh on the material, spray a sodium water glass solution on the surface of the glass fiber mesh at a spraying amount of 40g / square meter, and then lay another 30g material flat;

[0149] A layer of release film is laid on the surface of the laid material, which is then placed in a pressing machine and pressed for 60 seconds under vacuum conditions at a pressure of 0.1 MPa. The pressure is then increased to 2 MPa at a rate of 0.2 MPa / min and maintained for 120 seconds. The mold is opened to obtain a nano-silicon composite thermal insulation material with a thickness of 2 mm.

[0150] Example 32

[0151] Nano-silicon composite thermal insulation material includes a reinforcing mesh and thermal insulation layers arranged on both sides of the reinforcing mesh. The reinforcing mesh is a glass fiber mesh with a gram weight of 30g / square meter. The thermal insulation layer includes 70g of fumed silica, 30g of silicon carbide and 5g of fiber. The bulk density of the fumed silica is 50g / cubic meter, the particle size of the silicon carbide is 3μm, and the fiber is composed of glass fiber, high silica fiber and carbon fiber in a mass ratio of 1:2:4. The fiber has a diameter of 8μm and a length of 10mm.

[0152] During preparation, fumed silica, silicon carbide, glass fiber, high silica fiber and carbon fiber are accurately weighed and fully dispersed to obtain the materials;

[0153] Take two portions of material, 30g each;

[0154] Spread 30g of material on a 310mm*310mm square fixture, vibrate and flatten it, and spray a sodium water glass solution with a modulus of 3 on the surface of the material at a spraying amount of 40g / m2;

[0155] Lay a glass fiber mesh on the material, spray a sodium water glass solution on the surface of the glass fiber mesh at a spraying amount of 40g / square meter, and then lay another 30g material flat;

[0156] A layer of release film is laid on the surface of the laid material, which is then placed in a pressing machine and pressed for 60 seconds under vacuum conditions at a pressure of 0.1 MPa. The pressure is then increased to 2 MPa at a rate of 0.2 MPa / min and maintained for 120 seconds. The mold is opened to obtain a nano-silicon composite thermal insulation material with a thickness of 2 mm.

[0157] Example 33-Example 37

[0158] The difference between Example 33-Example 37 and Example 2 is that the pressing conditions of the materials are different after being placed in the pressing machine, specifically:

[0159] In Example 33, a release film was laid on the surface of the laid material, and the material was placed in a laminating machine and pressed under vacuum for 60 seconds at a pressure of 0.001 MPa. The pressure was then increased to 1 MPa at a rate of 0.1 MPa / min and maintained for 120 seconds. The mold was then opened to obtain a nano-silicon composite thermal insulation material.

[0160] In Example 34, a release film was laid on the surface of the laid material, and the material was placed in a laminating machine and pressed under vacuum for 60 seconds at a pressure of 0.2 MPa. The pressure was then increased to 5 MPa at a rate of 0.3 MPa / min and maintained for 120 seconds. The mold was then opened to obtain a nano-silicon composite thermal insulation material.

[0161] In Example 35, a release film was laid on the surface of the laid material, and the material was placed in a pressing machine and pressed under vacuum for 60 seconds at a pressure of 2 MPa. The pressure was then increased to 5 MPa at a rate of 0.2 MPa / min and maintained for 120 seconds. The mold was opened to obtain a nano-silicon composite thermal insulation material.

[0162] In Example 36, a release film was laid on the surface of the laid material, and the material was placed in a laminating machine and pressed under vacuum for 60 seconds at a pressure of 0.1 MPa. The pressure was then increased to 2 MPa at a rate of 1 MPa / min and maintained for 120 seconds. The mold was then opened to obtain a nano-silicon composite thermal insulation material.

[0163] In Example 37, a layer of release film is laid on the surface of the laid material, which is placed in a pressing machine and pressed for 180 seconds under vacuum conditions at a pressure of 2 MPa. The mold is opened to obtain the nano-silicon composite thermal insulation material.

[0164] Example 38

[0165] The nano-silicon composite thermal insulation material includes a reinforcing mesh and an insulation layer arranged on both sides of the reinforcing mesh. A flame retardant resin layer is arranged on the insulation layer. The reinforcing mesh is a glass fiber mesh with a gram weight of 30g / square meter. The insulation layer includes 70g of fumed silica, 30g of silicon carbide and 5g of high-silica fiber. The bulk density of the fumed silica is 50g / cubic meter, the particle size of the silicon carbide is 3μm, and the diameter of the high-silica fiber is 8μm and the length is 10mm; the flame retardant resin layer is a vinyl resin layer, and the vinyl resin was purchased from Langfang Wanteng Anti-corrosion Materials Co., Ltd., model FX-450.

[0166] During preparation, fumed silica, silicon carbide and high silica fiber are accurately weighed and fully dispersed to obtain the materials;

[0167] Take two portions of material, 22g each;

[0168] Spread 22g of material on a 310mm*310mm square fixture, vibrate and flatten it, and spray a sodium water glass solution with a modulus of 3 on the surface of the material at a spraying amount of 40g / m2;

[0169] Lay a glass fiber mesh on the material, spray a sodium water glass solution on the surface of the glass fiber mesh at a spraying amount of 40g / square meter, and then lay another 22g material flat;

[0170] A layer of release film is laid on the surface of the laid material, and the material is placed in a pressing machine and pressed for 60 seconds under vacuum conditions with a pressure of 0.1 MPa. The pressure is then increased to 2 MPa at a rate of 0.2 MPa / min and maintained for 120 seconds. After the mold is opened, a flame retardant resin layer with a thickness of 50 μm is coated on both sides of the material. After curing, a nano-silicon composite thermal insulation material is obtained.

[0171] Example 39

[0172] The only difference between this embodiment and Example 26 is that the carbon fiber is the carbon fiber coated with polyamic acid prepared in Preparation Example 1.

[0173] Comparative Example 1

[0174] A ceramic fiber aerogel felt with a thickness of 2 mm is used as comparative example 1, and the specific model is FRA-C650.

[0175] Comparative Example 2

[0176] A ceramic fiber aerogel sheet with a thickness of 2 mm is used as comparative example 2, and the specific model is AJ1200.

[0177] Comparative Example 3

[0178] A pre-oxidized silk aerogel felt with a thickness of 1.4 mm was used as comparative example 3, and the specific model was FRA-PC350.

[0179] Comparative Example 4

[0180] A wet-process glass fiber aerogel mat with a thickness of 1.4 mm was used as comparative example 4, and the specific model was FRA-G600.

[0181] Comparative Example 5

[0182] The nano-silicon composite thermal insulation material is prepared by accurately weighing 70g of fumed silica, 30g of silicon carbide, 5g of high-silica fiber, and 30g of 801 glue, dispersing the 801 glue in 250g of water, and then adding the fumed silica, silicon carbide, and high-silica fiber and fully dispersing the material;

[0183] Take two portions of material, 30g each;

[0184] Spread 30g of material on a 310mm*310mm square jig, scrape it flat to a thickness of 1mm, lay a glass fiber mesh with a gram weight of 30g / square meter on the material, and spread another material on the surface of the glass fiber mesh, scrape it flat to a thickness of 1mm;

[0185] A layer of release film is laid on the surface of the flattened material, which is placed in a pressing machine and pressed for 60 seconds under vacuum conditions at a pressure of 0.1 MPa. The pressure is then increased to 2 MPa at a rate of 0.2 MPa / min and maintained for 120 seconds. After the mold is opened, the product is placed in an oven to remove excess moisture to obtain a nano-silicon composite thermal insulation material.

[0186] Performance testing

[0187] Test 1. The 2 mm thick nano-silicon composite insulation material in Example 2, the ceramic fiber aerogel felt in Comparative Example 1, and the ceramic fiber aerogel sheet in Comparative Example 2 were selected as samples. The samples were placed on a high-temperature heating plate, the surface of the sample in contact with the high-temperature heating plate was the hot surface, and the surface away from the hot surface was the cold surface. Four temperature sensors were randomly set between the sample and the high-temperature heating plate to record the temperature of the hot surface. Four temperature sensors were correspondingly set on the cold surface of the sample to record the temperature of the cold surface. The temperature of the high-temperature heating plate was raised to 650°C, kept warm and pressurized at 0.45MP. The sensor temperatures of the hot and cold surfaces were recorded every 10s, and the average temperature of the cold surface and the temperature difference between the cold and hot surfaces were calculated. The results are shown in Figures 1 and 2. Figure 1 is a schematic diagram of the test results of the sample in Example 2, and Figure 2 is a comparison diagram of the test results of three samples.

[0188] Referring to Figures 1 and 2, 1#, 2#, 3#, and 4# in Figure 1 respectively refer to the temperatures measured by four temperature sensors, YRD in Figure 2 refers to the sample in Example 2, Fanrui refers to the sample in Comparative Example 1, and Jiayun refers to the sample in Comparative Example 2. It can be seen from the figure that the temperature rise rate of the cold surface of the nano-silicon composite thermal insulation material prepared in the present application is much lower than that of Comparative Example 1 and Comparative Example 2, and the temperature difference between the hot surface and the cold surface is also greater than that of Comparative Example 1 and Comparative Example 2, indicating that the nano-silicon composite thermal insulation material in the present application has excellent thermal insulation properties.

[0189] Test 2: The 1.4 mm thick nano-silicon composite thermal insulation material in Example 4, the nano-silicon composite thermal insulation material in Example 38, the ceramic fiber aerogel felt in Comparative Example 1, the pre-oxidized silk aerogel felt in Comparative Example 3, and the wet-process glass fiber aerogel felt in Comparative Example 4 were selected as samples, and the five samples were placed on a high-temperature heating plate respectively. The surface of the sample in contact with the high-temperature heating plate was the hot surface, and the surface away from the hot surface was the cold surface. Four temperature sensors were randomly set between the sample and the high-temperature heating plate to record the temperature of the hot surface. Four temperature sensors were correspondingly set on the cold surface of the sample to record the temperature of the cold surface. The temperature of the high-temperature heating plate was raised to 650°C, and the temperature was kept warm and pressurized at 0.45MP. The sensor temperatures of the hot surface and the cold surface were recorded every 10s, and the average temperature of the cold surface and the temperature difference between the cold surface and the hot surface were calculated. The results are shown in Figures 3 to 5. Figure 3 is a schematic diagram of the test results of the sample in Example 4, and Figure 4 is a schematic diagram of the test results of the sample in Example 38. Figures 3 and 4 1#, 2#, 3#, and 4# refer to the temperatures measured by the four temperature sensors, respectively. FIG5 is a comparison chart of the test results of the five samples. In the figure, the average value of 1.4 mm + YRD + 108 and the temperature difference of 1.4 mm + YRD + 108 refer to the average temperature of the cold surface and the temperature difference between the hot surface and the cold surface of the sample in Example 38, respectively. The average value of 1.4 mm + YRD and the temperature difference of 1.4 mm + YRD refer to the average temperature of the cold surface and the temperature difference between the hot surface and the cold surface of the sample in Example 4, respectively. The average value of .4mm+Fanrui pre-oxidized wire and the temperature difference of 1.4mm+Fanrui pre-oxidized wire refer to the average temperature of the cold side and the temperature difference between the hot side and the cold side of the samples in Comparative Example 3; the average value of 1.4mm+Fanrui wet-process glass fiber and the temperature difference of 1.4mm+Fanrui wet-process glass fiber refer to the average temperature of the cold side and the temperature difference between the hot side and the cold side of the samples in Comparative Example 4; the average value of 2.0mm+Fanrui ceramic fiber and the temperature difference of 2.0mm+Fanrui ceramic fiber refer to the average temperature of the cold side and the temperature difference between the hot side and the cold side of the samples in Comparative Example 1.

[0190] As can be seen from Figures 3-5, the cold surface temperature rise rate of the sample in Example 4 is the lowest, indicating that the thermal insulation material of the present application has excellent thermal insulation performance. Even though the thickness is lower than that of the sample in Comparative Example 1, it still exhibits a good thermal insulation effect. Comparing Example 4 and Example 38, after the flame retardant resin layer is coated on the surface of the thermal insulation layer, the thermal insulation effect of the thermal insulation material is relatively reduced. Analysis shows that the main function of the flame retardant resin is flame retardancy and prevention of powder loss, and its thermal insulation effect is not as good as that of Example 4. However, as can be seen from Figure 5, although the temperature rise rate of the sample in Example 38 is higher than that of the sample in Comparative Example 1 in the initial stage of temperature rise, the temperature rise rate of the sample in Example 38 gradually decreases as time goes on, indicating that the thermal insulation material in the present application can maintain a long-lasting thermal insulation effect and a long service life.

[0191] Test 3: High temperature resistance test: Use the flame of a spray gun to treat the sample, the flame temperature is 1200℃, observe the sample, and record the time it takes for the sample to burn through.

[0192] Test 4: The tensile strength of Example 2, Example 18-Example 32, and Example 39 was tested with reference to GB / T17911-2006.

[0193] Test 5: Powder loss rate test: Select samples of Example 2, Example 4, Example 8-Example 11, Example 18-Example 25, Example 27, Example 38 and Example 39, accurately weigh the sample mass, and then put the sample into a vibrating sieve with a vibration frequency of 1400 times / min and an amplitude of 3mm. After vibrating for 5 minutes, take out the sample and weigh the sample again. The powder loss rate is expressed as the mass loss rate.

[0194] Table 1 Test results of test 3 in Example 1-Example 8

[0195] Table 2 Test results of test 3 in Examples 9 to 16

[0196] Table 3 Test results of test 3 in Example 17-Example 24

[0197] Table 4 Test results of test 3 in Examples 25-32

[0198] Table 5 Test results of test 3 in Examples 33-37 and Comparative Example 5

[0199] Table 6 Test results of Example 2, Example 18-Example 24 Test 4

[0200] Table 7 Test results of Example 25-Example 32, Example 39 Test 4

[0201] Table 8 Test results of Example 2, Example 8-Example 11, Example 18-Example 20 Test 5

[0202] Table 9 Test results of Example 21-Example 27, Example 38, and Example 39 Test 5

[0203] Referring to Tables 1 to 5, compared with Comparative Example 5, the thermal insulation materials in Examples 1 to 3 exhibit better high temperature resistance, indicating that by referring to the raw materials disclosed in this application and using an inorganic adhesive to bond the thermal insulation layer and the reinforcement layer, the thermal insulation material can have better thermal insulation performance. Compared with using glue to bond the raw materials, the thermal insulation layer in this application relies on tightly stacked nano-silicon, sunscreen and fiber to achieve thermal insulation performance. The porous nano-silicon itself can effectively block heat conduction. In the later long-term use process, the thermal insulation layer will not split due to failure and degradation of the glue, so that the thermal insulation performance of the thermal insulation material is excellent and long-lasting.

[0204] In combination with Example 2 and Example 4-Example 7, as the thickness decreases, the high temperature resistance of the thermal insulation material shows a downward trend, indicating that the thickness affects the thermal insulation effect of the thermal insulation material. The smaller the thickness, the less conducive it is to the thermal insulation of the thermal insulation material.

[0205] In combination with Examples 2, 8, and 11, the bulk density of fumed silica is within a certain range. As the bulk density decreases, the thermal insulation effect of the thermal insulation material becomes better, indicating that the smaller the bulk density of fumed silica and the lower the thermal conductivity of fumed silica, the better the thermal insulation effect. However, in combination with Example 10, it can be seen that if the bulk density is too low, the fumed silica will easily float because it is too light, which will affect the quality of the finished product when preparing the thermal insulation material and reduce the thermal insulation performance of the thermal insulation material.

[0206] In combination with Example 2 and Example 13-Example 17, the effect of the particle size of silicon carbide on the thermal insulation effect of the thermal insulation material is: the smaller the particle size of silicon carbide, the larger the surface area, and therefore there are more interfaces to hinder heat conduction, thereby improving the thermal insulation effect, but too small a particle size will also reduce the quality of the finished product, and thus reduce the thermal insulation effect.

[0207] In combination with Example 2 and Example 18-Example 23, the diameter and length of the high-silica fiber will also affect the thermal insulation of the thermal insulation material. The smaller the diameter and the shorter the length, the smaller the pores of the fiber and the more evenly dispersed it is in the material, thereby improving the thermal insulation effect of the thermal insulation material. As the length increases, it is not conducive to the dispersion of the fiber in the material, which reduces the quality of the thermal insulation material, which is manifested as a shortened burn-through resistance time.

[0208] In combination with Example 2, Example 24-Example 30, glass fiber, high silica fiber and carbon fiber all have good thermal insulation properties. Considering the production cost and the comprehensive performance of the thermal insulation material, it can be considered to compound the three in a specific proportion so that the thermal insulation material has excellent thermal insulation performance while also having good strength and other properties.

[0209] In combination with Example 2 and Example 31-Example 35, compared with direct pressing with a certain pressure, first using a lower pressure for pressing to pre-expel the air in the material, and then using a higher pressure for pressing to further expel the air in the material and shape the material, can effectively reduce the air in the molded material, so that the material has a higher thermal insulation effect; while using a higher pressure for pressing at one time will cause the air in the material to not have time to be discharged and form pores, and the pores will reduce the thermal insulation performance of the material. Therefore, the pressing method in this application can ensure that the material has a better thermal insulation effect.

[0210] In combination with Example 37 and Example 25, coating the carbon fiber surface with a polyamic acid coating can improve the thermal stability of the carbon fiber at high temperatures, thereby appropriately extending the anti-burn-through time of the thermal insulation material.

[0211] Referring to Tables 6 and 7, combined with Examples 2 and 18–25, it can be seen that a fiber diameter that is too short prevents entanglement and weakens connectivity with other raw materials, resulting in relatively low tensile strength. On the other hand, a fiber diameter that is too large may hinder fiber dispersion within the system, thus also affecting tensile strength. While longer fibers can increase the tensile strength of the insulation material, excessive fiber length can lead to fiber aggregation and difficulty dispersing within the system, ultimately reducing tensile strength.

[0212] In conjunction with Examples 26-32, while using a single fiber type can improve the tensile strength of the thermal insulation material, the corresponding burn-through resistance is reduced. Therefore, considering both burn-through resistance and tensile strength, a combination of three fibers can be used. In conjunction with Examples 26 and 39, coating the carbon fibers with a polyamic acid coating can also improve the tensile strength of the thermal insulation material and extend the burn-through resistance.

[0213] Referring to Table 8 and Table 9, combined with Example 2 and Example 8 to Example 11, it can be seen that although a smaller bulk density of silicon carbide can improve the thermal insulation effect of the thermal insulation material, silicon carbide is too light and easily floats, thereby increasing the powder loss rate.

[0214] In conjunction with Examples 18 to 25, the smaller the fiber diameter and the shorter the length, the more likely it is for the fiber to detach from the system, increasing the powder loss rate of the thermal insulation material. In conjunction with Examples 36 and 39, a polyamic acid coating is coated on the surface of the carbon fiber. The polyamic acid coating can form a bond with the fumed silica, thereby appropriately increasing the connection between the raw materials and reducing the occurrence of powder loss.

[0215] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. Nano-silicon composite heat insulation material, characterized in that: It includes a reinforcing mesh and heat insulation layers arranged on both sides of the reinforcing mesh, and the reinforcing mesh and the heat insulation layers are bonded by an inorganic binder; The raw materials for preparing the heat insulation layer include the following components: 60-90 parts by weight of nano-silicon, 15-35 parts by weight of a light-shielding agent, and 1-10 parts by weight of fibers; The light-shielding agent is silicon carbide, and the particle size is 0.01-15 μm; The fibers include glass fibers, high-silica fibers, and carbon fibers, and the weight ratio of the three is (1-2):(2-3):1; the diameter of the fibers is 3-15 μm and the length is 10-20 mm; The nano-silicon is fumed silica or silica aerogel; The bulk density of the fumed silica is 20 - 100 g / m 3 ; The surface of the carbon fiber is coated with a polyamic acid coating. The specific preparation method is as follows: dissolve pyromellitic dianhydride and diaminodiphenyl ether in N,N-dimethylformamide, react under nitrogen protection, then adjust the pH to 9 with ammonia water, impregnate the carbon fiber, and then dry and disperse to obtain carbon fiber coated with a polyamic acid coating; The reinforcing mesh is a glass fiber mesh, a high-silica fiber mesh, a basalt fiber mesh, a ceramic fiber mesh, a pre-oxidized fiber mesh, a carbon fiber mesh, or a metal mesh; The preparation of the nano-silicon composite heat insulation material includes the following steps: Accurately weigh the raw materials for the heat insulation layer and mix them evenly; Lay the heat insulation layer raw materials flat, spray the inorganic binder, then lay the reinforcing mesh, spray the inorganic binder on the reinforcing mesh, and then lay another layer of heat insulation layer raw materials; First press at 0.001-0.2 Mpa, and then raise the pressure to 1-5 Mpa at a speed of 0.1-0.3 Mpa / min for pressing. After molding, the nano-silicon composite heat insulation material is obtained.

2. The nano-silicon composite heat insulation material according to claim 1, characterized in that: The inorganic binder is selected from one or more of sodium silicate, potassium silicate, lithium silicate, and nano-silicon resin.

3. The nano-silicon composite thermal insulation material according to claim 1, characterized in that: The particle size of the silicon carbide is 3-5 μm.

4. The nano-silicon composite heat insulation material according to claim 1, characterized in that: A flame-retardant resin layer is provided on the surface of the heat insulation layer.

5. The preparation method of the nano-silicon composite heat insulation material according to any one of claims 1-4, characterized in that: It includes the following steps: Accurately weigh the raw materials for the heat insulation layer and mix them evenly; Lay the heat insulation layer raw materials flat, spray the inorganic binder, then lay the reinforcing mesh, spray the inorganic binder on the reinforcing mesh, and then lay another layer of heat insulation layer raw materials; First press at 0.001-0.2 Mpa, and then raise the pressure to 1-5 Mpa at a speed of 0.1-0.3 Mpa / min for pressing. After molding, the nano-silicon composite heat insulation material is obtained.

Images