A method for preparing a composite thermal insulation material

Abstract

The application provides a preparation method of a composite heat insulation material, and relates to the field of fireproof heat insulation materials. The heat insulation composite material comprises, in sequence, an anti-ablation layer, a transition layer, a hot surface protection layer, a heat insulation layer, a heat resistance layer and a cold surface protection layer. The specific steps comprise the following steps. Step one, preparing the coating or blank of each layer and cutting the blank; step two, sequentially attaching the heat insulation layer and the heat resistance layer to the end surface of the hot surface protection layer, embedding the welding piece composed of the hot surface protection layer, the heat insulation layer and the heat resistance layer into the cold surface protection layer, and welding; step three, brushing the transition layer on the surface of the hot surface protection layer, and brushing the anti-ablation layer on the surface of the transition layer by using a multiple brushing process. The composite material obtained by the method has the characteristics of excellent fireproof heat insulation performance, thin thickness, light weight, good long-term stability and the like, and has the advantages of simple structure, convenient installation, wide application range and the like.

Description

[0001] The application is a divisional application of patent application No. 202411158584.5 and has the title "Integrated heat-insulating composite layer and preparation method thereof". TECHNICAL FIELD

[0002] The application relates to the technical field of fireproof heat-insulating materials, in particular to a preparation method of a composite heat-insulating material. BACKGROUND

[0003] Aerodynamic heat environment refers to a complex thermal environment generated by the intense aerodynamic interaction between an object and the surrounding air during high-speed movement. Aerodynamic heat not only causes the surface temperature of the aircraft to rise sharply, resulting in the decline of the strength, rigidity and other properties of the outer wall of the aircraft, but also easily affects the internal components of the aircraft through heat transfer, causing the aircraft to be unable to operate normally. Therefore, in order to avoid the influence of the aerodynamic heat environment, a heat-insulating protective structure is usually arranged on the surface of a high-speed aircraft such as a missile during the research and design process of the high-speed aircraft, so as to not only achieve heat insulation and protection and ensure the stability of the internal cavity of the aircraft, but also effectively avoid the influence of high-temperature environments such as accidental fires during operation. The heat-insulating protective structure on the surface of the aircraft in the prior art mainly adopts a heat-insulating layer in the form of a fiber felt coating and a protective coating spraying. However, the fiber felt coating has problems such as large weight, high space occupancy and the like, and also has problems such as large ablation amount after ablation, poor long-term stability and poor heat-insulating performance, which do not meet the needs of the long-term flight operation of the aircraft such as a missile in the aerodynamic heat environment. Although the protective coating spraying can reduce the weight and space occupancy to a certain extent, the protective coating is easily subjected to problems such as smoking, slagging, cracking, and peeling and stripping due to low bonding strength, and is prone to failure, so that the protective coating loses the protective effect on the surface of the aircraft, and the aircraft is directly exposed to the aerodynamic heat environment. It can be seen that there is still a lack of a heat-insulating protective structure with the functions of heat insulation and fire prevention, light weight, thin thickness and good long-term stability in the prior art for long-term use in the aerodynamic heat environment. SUMMARY

[0004] In view of the problems in the prior art, the application aims to provide a preparation method of a composite heat-insulating material. The composite material prepared by the method has the advantages of good heat-insulating and fireproof performance, light weight, thin thickness, good long-term stability and easy installation, and can be effectively used for the thermal protection of the outer wall of a high-speed aircraft such as a missile.

[0005] The object of the application is achieved by the following technical scheme.

[0006] The application relates to a preparation method of a composite heat insulation material, and the heat insulation composite material comprises, in sequence, an anti-ablation layer, a transition layer, a hot surface protection layer, a heat insulation layer, a heat resistance layer and a cold surface protection layer; the anti-ablation layer is made of intumescent fireproof paint, the transition layer is made of primer, the hot surface protection layer and the cold surface protection layer are made of metal titanium foil, the heat insulation layer is made of aerogel felt, and the heat resistance layer is made of phase change material.

[0007] The specific preparation method is as follows: step one, preparing the anti-ablation layer, the transition layer coating and the blank of the hot surface protection layer, the heat insulation layer, the heat resistance layer and the cold surface protection layer according to requirements, and cutting the blank; step two, placing the hot surface protection layer on the working table plane, and sequentially attaching the heat insulation layer and the heat resistance layer to the end surface of the hot surface protection layer; then, embedding the welding part composed of the hot surface protection layer, the heat insulation layer and the heat resistance layer into the cold surface protection layer, folding the outer circle of the hot surface protection layer to form the coating of the cold surface protection layer, and welding the connecting part between the hot surface protection layer and the cold surface protection layer; step three, firstly brushing the transition layer on the surface of the hot surface protection layer (i.e. the side surface far from the heat insulation layer); then, brushing the anti-ablation layer on the surface of the transition layer by using the multiple brushing process, so as to obtain the heat insulation composite material.

[0008] Based on the further optimization of the above scheme, the thickness of the anti-ablation layer is 0.6-1.0 mm; the intumescent fireproof paint comprises a film forming substance, a flame retardant and a functional filler, and the mass ratio among the film forming substance, the flame retardant and the functional filler is 2-3:6-10:1-3; wherein the film forming substance is a high-elasticity polyurethane polymer (wherein the high-elasticity polyurethane polymer is polymerized by one or both of polycaprolactone dihydric alcohol and polyether dihydric alcohol and aliphatic polyisocyanate HDI); the flame retardant is composed of polyphosphoric acid ammonium, pentaerythritol and melamine, and the mass ratio among them is 5-8:4-7:2-4; the functional filler is composed of nanoscale aluminum hydroxide, expanded graphite and superfine ceramic hollow microbeads, and the mass ratio among them is 5-10:2-5:3-8. The particle size of the superfine ceramic hollow microbeads is 20-50 mu m, and the melting point thereof is not lower than 1600 DEG C.

[0009] The flame retardant composed of polyphosphoric acid ammonium, pentaerythritol and melamine is matched with the film forming substance to expand and carbonize in a high-temperature environment, so as to form a dense carbonized layer, thereby realizing the heat insulation and fireproofing purposes; meanwhile, the functional filler composed of nanoscale aluminum hydroxide, expanded graphite and superfine ceramic hollow microbeads is used to inhibit the smoke emission amount in the high-temperature carbonization process and reduce the material loss by using the nanoscale aluminum hydroxide, to enhance the carbonized layer strength by using the nanoscale aluminum hydroxide, and to fill the voids of the carbonized layer after expansion by using the expanded graphite and the superfine ceramic hollow microbeads, thereby enhancing the heat insulation performance of the carbonized layer.

[0010] Further optimization based on the above scheme, the thickness of the transition layer is 40-60 μm, and the transition layer uses epoxy primer; the transition layer improves the bonding force between the ablation-resistant layer and the thermal surface protection layer.

[0011] Further optimization based on the above scheme, the thermal surface protection layer thickness (in a flat state) is 0.03-0.1 mm; the thermal surface protection layer uses a metal embossed titanium foil structure, i.e., an array of protrusions is arranged on the surface of the flat titanium foil structure; the shape of the protrusions is any one of rice grain, pearl, and water drop; the diameter of the protrusions is 1-2.5 mm, and the height is 0.4-1.0 mm; the distance between adjacent two protrusions is 4-8 mm; the number of protrusions per unit area in the thermal surface protection layer is 1.5x10 4 ~6x10 4 The protrusions of the thermal surface protection layer have the following effects: 1) the strain hardening effect generated in the pressing process of the protrusions improves the rigidity of the thermal surface protection layer; 2) the distribution of the protrusions increases the roughness of the thermal surface protection layer to the transition layer, and then the transition layer increases the interfacial bonding force between the thermal surface protection layer and the ablation-resistant layer; 3) the preparation of the protrusions reduces the wrinkles formed in the forming process of the protection layer, thereby reducing the weak points of failure and avoiding damage to the protection layer, and improving the overall liquid penetration resistance of the composite structure; 4) the protrusions provide a buffer gap for the ablation-resistant layer, ensuring that the ablation-resistant layer completes the expansion and carbonization, while avoiding cracking and peeling of the ablation-resistant layer due to the expansion impact force; 5) the protrusions convert the mirror reflection of the reflecting surface into a dot-matrix diffuse reflection, thereby expanding the reflection area of the heat and improving the reflection efficiency; 6) the continuous protrusions cooperate with the heat insulation layer to form multiple cavity matrices, thereby changing the interlayer flow field and forming micro air gaps, effectively blocking heat conduction and inhibiting heat convection, and improving the heat insulation effect; 7) the thermal surface protection layer and the heat insulation layer are in point contact, thereby reducing the heat conduction between the thermal surface protection layer and the heat insulation layer, allowing the heat to be effectively dissipated in the cavity matrix, and further improving the heat insulation effect.

[0012] Based on the further optimization of the above scheme, the thickness of the heat insulation layer is 2-5mm, and the heat insulation layer adopts basalt fiber reinforced silica aerogel felt; wherein the diameter of the basalt fiber is not greater than 6μm, the mass ratio of the basalt fiber to the silica aerogel is 1:0.78-1, and the thermal conductivity of the basalt fiber reinforced silica aerogel felt at room temperature is 0.017-0.020W / (m•K). Using basalt fibers with small diameters as reinforcing fibers for nano-porous silica aerogel can effectively limit the solid thermal conduction of the fibers themselves, making the basalt fiber felt itself have a lower thermal conductivity; at the same time, using short-diameter basalt fibers to form a low-bulk-density preform can further reduce the bulk density of the fiber-reinforced aerogel composite while ensuring its mechanical properties, and the diameter of the fiber preform is close to the wavelength of near-infrared radiation, thereby allowing strong diffraction and scattering of near-infrared radiation, thereby further enhancing the high-temperature infrared radiation heat conduction barrier effect; in addition, the addition of basalt fibers can effectively solve the problems of large brittleness and easy breaking of pure aerogel. The bulk density of the basalt fiber reinforced silica aerogel felt is 150-170kg / m 3 , the bulk density of the preform formed by the basalt fiber is 80-90kg / m 3 , and the bulk density of the silica aerogel is 70-80kg / m 3 .

[0013] Based on the further optimization of the above scheme, the thickness of the heat insulation layer is 2-5mm; the phase change material is composed of phase change raw materials and matrix materials, the phase change raw materials are microcapsules, the particle size of the microcapsules is 10-100μm, wherein the encapsulating material of the microcapsules is a mixture of melamine, formaldehyde and urea (by combining urea and a specific formula, the formaldehyde residue is effectively reduced, and the coating performance of the encapsulating material is avoided), and the phase change core of the microcapsules is paraffin; the matrix material is epoxy resin; the phase change temperature of the phase change material is 95-120℃, the density is 1.0-1.3g / cm 3 , and the phase change enthalpy value is 220-260J / g. The mass ratio between the epoxy resin (matrix material) and the microcapsules (phase change raw materials) is 1:1-15; the mass ratio between the encapsulating material (i.e. melamine formaldehyde resin) of the microcapsules and paraffin is 6:1; and the mass ratio of melamine, formaldehyde and urea in the encapsulating material is 10:20-30:1-5.

[0014] Based on the further optimization of the above scheme, the thickness of the cold face protection layer is 0.03-0.1mm, and the cold face protection layer is a flat and smooth titanium foil, which is convenient for installation of the cold face protection layer.

[0015] Based on the further optimization of the above scheme, the hot face protective layer and the cold face protective layer in the step two are cleaned with ethyl acetate before use and dried. The welding process requirement in the step two is that 1-3 rows of welding is adopted, the welding point spacing is 6±2mm, and the welding point indentation diameter is 1±0.5mm.

[0016] Based on the further optimization of the above scheme, the multiple coating process of the anti-ablation layer is specifically that the thickness of the anti-ablation layer is K, divided into N times of coating, and the thickness of each coating is K / N, and after each layer is coated, drying and curing are performed according to requirements to ensure that the previous layer is completely cured before the next layer is constructed; the multiple coating process can effectively prevent the anti-ablation layer from forming a bulge, thereby avoiding problems such as air holes and cracking during the expansion and carbonization process. During the coating process of the anti-ablation layer and the transition layer, the construction environment temperature is 5-40℃, the component surface temperature is 5-45℃, the air humidity during the coating process is not more than 90%, the air flow of the coating site is maintained, and the wind speed is not more than 5m / s.

[0017] The following are the effects of the technical scheme of the present application:

[0018] The present application realizes the purpose of flame blocking and heat insulation by the dense carbonized layer formed by the heat expansion and carbonization of the anti-ablation layer of the intumescent fire retardant coating, and through the cooperation between the hot face protective layer, the transition layer and the anti-ablation layer, not only can reflect and block thermal radiation, realize fireproof and heat insulation, but also effectively improve the interlayer bonding force and provide a buffer for the expansion and carbonization process, avoiding problems such as cracking and falling off during the expansion and carbonization process of the anti-ablation layer. Through the cooperation between the heat insulation layer and the heat blocking layer, the heat insulation effect is improved by the synergistic effect of phase change heat absorption and aerogel felt heat insulation; by the synergistic cooperation between the hot face protective layer, the heat insulation layer, the heat blocking layer and the cold face protective layer, not only the heat insulation layer and the heat blocking layer are fixed and protected, avoiding problems such as falling off, deviation and cracking between them (i.e. the heat insulation layer and the heat blocking layer), but also a large number of cavity matrixes are formed to inhibit and partition heat conduction, avoid the formation of temperature collection points, further improve the heat insulation efficiency and effect, in addition, the gap between the composite material and the structural part can be effectively avoided, ensuring the stability of the composite material coating and fireproof and heat insulation. The hot face protective layer and the cold face protective layer can also improve the resistance to infiltration and corrosion of the whole composite material, thereby ensuring that each layer fully plays its role. The composite material prepared by the method of the present application not only has excellent fireproof and heat insulation performance, thin thickness and light weight, but also has the advantages of simple structure, easy installation and wide application range, and can be used for fireproof and heat insulation of various equipment hot end parts in a high temperature environment of 400℃-1200℃. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1A schematic diagram of the whole heat insulation composite material in the embodiment of the present application.

[0020] Figure 2 A schematic diagram of the structure of the hot surface protection layer of the heat insulation composite material in the embodiment of the present application.

[0021] In the figure, 10, an ablation-resistant layer; 20, a transition layer; 30, a hot surface protection layer; 40, a heat insulation layer; 50, a heat resistance layer; and 60, a cold surface protection layer. DETAILED DESCRIPTION

[0022] For the convenience of understanding of those skilled in the art, the present application is further described below in combination with the embodiments and the accompanying drawings, and the content mentioned in the embodiments is not a limitation on the present application.

[0023] Embodiment 1

[0024] A preparation method of a composite heat insulation material, referring to Figure 1 The heat insulation composite material comprises, in sequence, an ablation-resistant layer 10, a transition layer 20, a hot surface protection layer 30, a heat insulation layer 40, a heat resistance layer 50, and a cold surface protection layer 60; the thickness of the ablation-resistant layer 10 is 0.6 mm; the ablation-resistant layer 10 adopts an intumescent fire retardant coating, which comprises a film-forming substance, a flame retardant, and a functional filler, and the mass ratio among the film-forming substance, the flame retardant, and the functional filler is 2:6:1; the film-forming substance is a high-elasticity polyurethane polymer (the high-elasticity polyurethane polymer is polymerized from one or both of polycaprolactone diol and polyether diol and aliphatic polyisocyanate HDI); the flame retardant is composed of ammonium polyphosphate, pentaerythritol, and melamine, and the mass ratio among them is 5:4:2; and the functional filler is composed of nano-sized aluminum hydroxide, expanded graphite, and ultra-fine ceramic hollow microbeads (the average particle size of the ultra-fine ceramic hollow microbeads is 20 μm, and the melting point thereof is not lower than 1600 ℃), and the mass ratio among them is 5:2:3.

[0025] The thickness of the transition layer 20 is 40 μm, and the transition layer 20 adopts an epoxy primer. The thickness of the hot surface protection layer 30 (in a flat state of the hot surface protection layer 30) is 0.03 mm; the hot surface protection layer 30 adopts a metal embossed titanium foil structure, that is, an array of protrusions is arranged on the surface of a flat titanium foil structure (refer to Figure 2 The protrusions of the hot surface protection layer 30 are directed toward the transition layer 20); the shape of the protrusions adopts a rice grain shape; the diameter of the protrusions is 1 mm, and the height thereof is 0.4 mm; the distance between two adjacent protrusions is 4 mm; and the number of the protrusions per unit area in the hot surface protection layer 30 is 6x10 4

[0026] ​The thickness of the thermal insulation layer 40 is 2 mm, and the thermal insulation layer 40 is basalt fiber reinforced silica aerogel felt; wherein the diameter of the basalt fiber is not greater than 6 μm, the mass ratio of the basalt fiber to the silica aerogel is 1:0.78, and the thermal conductivity of the basalt fiber reinforced silica aerogel felt at room temperature is 0.020 W / (m•K); the bulk density of the basalt fiber reinforced silica aerogel felt is 159.74 kg / m 3 , the bulk density of the basalt fiber preform is 89.74 kg / m 3 , and the bulk density of the silica aerogel is 70 kg / m 3 . The thickness of the heat resistance layer 50 is 2 mm; the heat resistance layer 50 is made of a phase change material, the phase change material is composed of a phase change raw material and a matrix material, the phase change raw material is a microcapsule, the average particle size of the microcapsule is 30 μm, wherein the encapsulating material of the microcapsule is a mixture of melamine, formaldehyde and urea, and the mass ratio of melamine, formaldehyde and urea in the encapsulating material is 10:20:1; the phase change core of the microcapsule is paraffin, and the mass ratio between the encapsulating material (i.e. melamine formaldehyde resin) and paraffin is 6:1; the matrix material is epoxy resin, and the mass ratio between the epoxy resin (matrix material) and the microcapsule (phase change raw material) is 1:2; the phase change temperature of the phase change material is 95℃, the density is 1.0 g / cm 3 , and the phase change enthalpy value is 220 J / g. The thickness of the cold surface protection layer 60 is 0.03 mm, and the cold surface protection layer 60 is a flat and smooth titanium foil.

[0027] The specific preparation method is as follows:

[0028] Step one, prepare the coating of the anti-ablation layer 10, the transition layer 20 (i.e. uniformly mix the raw materials of the anti-ablation layer 10 according to the above formula to obtain the anti-ablation layer 10 coating, and the transition layer 20 coating can use existing products in the art), and the blank of the hot surface protection layer 30, the thermal insulation layer 40, the heat resistance layer 50 and the cold surface protection layer 60 (the hot surface protection layer 30 can be embossed by pressing the existing flat and smooth titanium foil which meets the thickness size according to the above size; the thermal insulation layer 40 is prepared according to the above ratio of basalt fiber and silica aerogel to prepare basalt fiber reinforced silica aerogel felt, and the preparation method adopts the existing preparation method of fiber reinforced aerogel felt; the heat resistance layer 50 is uniformly mixed with each material according to the above proportion to prepare the heat resistance layer 50; and the cold surface protection layer 60 uses the existing titanium foil with composite thickness size), and the blank is cut (i.e. the blank of the hot surface protection layer 30, the thermal insulation layer 40, the heat resistance layer 50 and the cold surface protection layer 60 is cut according to the size of the component which needs to be thermally insulated and the thickness of the thermal insulation layer 40 and the heat resistance layer 50, and the cutting method is a conventional means in the art, which is not limited in the embodiment).

[0029] Step two, before use, the hot face protective layer 30 and the cold face protective layer 60 are cleaned with ethyl acetate and dried; the hot face protective layer 30 is placed on the workbench plane (specifically: the side of the hot face protective layer 30 with protrusions is placed downward), and the heat insulation layer 40 and the heat resistance layer 50 are sequentially attached to the end face of the hot face protective layer 30; then, the welding part composed of the hot face protective layer 30, the heat insulation layer 40 and the heat resistance layer 50 is embedded into the cold face protective layer 60 (if the edge material is too much to be embedded, the outer edge of the cold face protective layer 60 can be appropriately trimmed), and then the outer circle of the hot face protective layer 30 is folded inward to form a package for the cold face protective layer 60 (after folding, a hammer can be used to knock the folded part to ensure tightness); finally, check whether the hot face protective layer 30, the heat insulation layer 40, the heat resistance layer 50 and the cold face protective layer 60 are misaligned, abnormally bulged or have other problems, and if there is no abnormality, weld the connection between them (i.e. between the hot face protective layer 30 and the cold face protective layer 60); the welding process requires: single-row welding, welding point spacing 6±2mm, welding point indentation diameter 1±0.5mm; before each start of the welding machine, a sample of the same structure and thickness needs to be welded for 5 points, and after passing the tearing test, formal welding is carried out. The edges of the hot face protective layer 30 and the cold face protective layer 60 after welding are ground and deburred.

[0030] Step three, first, apply the transition layer 20 to the surface of the hot face protective layer 30 (i.e. the side surface away from the heat insulation layer 40). Then, use a multiple coating process to apply the ablative layer 10 to the surface of the transition layer 20. The multiple coating process of the ablative layer 10 is as follows: the thickness of the ablative layer 10 is 0.6mm, which is divided into 6 coatings, each with a thickness of 0.1mm. After each coating, dry and cure as required to ensure that the previous layer is completely cured before applying the next layer. During the coating of the ablative layer 10 and the transition layer 20, the construction environment temperature is 15℃, the component surface temperature is 20℃, the air humidity during coating is not more than 90%, the air flow in the coating site is maintained and the wind speed is not more than 5m / s. Finally, the heat-insulating composite material is obtained.

[0031] Example 2:

[0032] A method for preparing a composite heat-insulating material, see Figure 1As shown, the thermal insulation composite comprises, in sequence, an ablative layer 10, a transition layer 20, a hot-face protection layer 30, a thermal insulation layer 40, a thermal resistance layer 50, and a cold-face protection layer 60; wherein the thickness of the ablative layer 10 is 0.8 mm; the ablative layer 10 adopts an intumescent fire retardant coating, which comprises a film-forming substance, a flame retardant, and a functional filler, and the mass ratio between the film-forming substance, the flame retardant, and the functional filler is 2.5:8:2; wherein the film-forming substance is a high-elasticity polyurethane polymer (wherein the high-elasticity polyurethane polymer is polymerized from one or both of polycaprolactone diol and polyether diol and aliphatic polyisocyanate HDI); the flame retardant is composed of ammonium polyphosphate, pentaerythritol, and melamine, and the mass ratio between them is 6:5:3; and the functional filler is composed of nanoscale aluminum hydroxide, expanded graphite, and superfine ceramic hollow microbeads (the average particle diameter of the superfine ceramic hollow microbeads is 35 μm, and the melting point thereof is not lower than 1600℃), and the mass ratio between them is 8:3:5.

[0033] The thickness of the transition layer 20 is 50 μm, and the transition layer 20 adopts an epoxy primer. The thickness of the hot-face protection layer 30 (in a flat state) is 0.06 mm; the hot-face protection layer 30 adopts a metal embossed titanium foil structure, that is, an array of protrusions is arranged on the surface of a flat titanium foil structure (for reference Figure 2 , the direction of the protrusions of the hot-face protection layer 30 is towards the transition layer 20); the shape of the protrusions adopts a pearl shape; the diameter of the protrusions is 1.5 mm, and the height thereof is 0.7 mm; the distance between two adjacent protrusions is 6 mm; and the number of protrusions per unit area in the hot-face protection layer 30 is 3.5x10 4 .

[0034] The thickness of the thermal insulation layer 40 is 3 mm, and the thermal insulation layer 40 adopts a basalt fiber reinforced silica aerogel felt; wherein the diameter of the basalt fiber is not greater than 6 μm, the mass ratio between the basalt fiber and the silica aerogel is 1:0.85, and the thermal conductivity of the basalt fiber reinforced silica aerogel felt at room temperature is 0.018 W / (m•K); the bulk density of the basalt fiber reinforced silica aerogel felt is 163.24 kg / m 3 , the bulk density of the preform formed by the basalt fiber is 88.24 kg / m 3 , and the bulk density of the silica aerogel is 75 kg / m 3The thickness of the heat resistance layer 50 is 3 mm; the heat resistance layer 50 adopts a phase change material, the phase change material is composed of a phase change raw material and a matrix material, the phase change raw material is a microcapsule, the average particle size of the microcapsule is 60 μm, wherein the encapsulating material of the microcapsule is a mixture of melamine, formaldehyde and urea, the mass ratio of melamine, formaldehyde and urea in the encapsulating material is 10:25:3; the phase change core of the microcapsule is paraffin, the mass ratio between the encapsulating material (i.e. melamine formaldehyde resin) and paraffin is 6:1; the matrix material is epoxy resin, the mass ratio between the epoxy resin (matrix material) and the microcapsule (phase change raw material) is 1:6; the phase change temperature of the phase change material is 110°C, the density is 1.2 g / cm 3 , and the phase change enthalpy value is 240 J / g. The thickness of the cold surface protection layer 60 is 0.06 mm, and the cold surface protection layer 60 is a flat and smooth titanium foil.

[0035] The specific preparation method is as follows:

[0036] Step one, prepare the coating of the anti-ablation layer 10, the transition layer 20 (i.e. uniformly mix the raw materials of the anti-ablation layer 10 according to the above formula to obtain the anti-ablation layer 10 coating, and the transition layer 20 coating can adopt existing products in the art) and the blank of the hot surface protection layer 30, the heat insulation layer 40, the heat resistance layer 50 and the cold surface protection layer 60 (the hot surface protection layer 30 can be embossed by pressing the existing flat and smooth titanium foil with a thickness size according to the above size; the heat insulation layer 40 is prepared according to the above ratio of basalt fiber and silica aerogel to prepare a basalt fiber reinforced silica aerogel felt, and the preparation method adopts the existing preparation method of fiber reinforced aerogel felt; the heat resistance layer 50 is uniformly mixed with each material according to the above ratio to prepare the heat resistance layer 50; the cold surface protection layer 60 adopts an existing titanium foil with a composite thickness size), and the blank is cut (i.e. the blank of the hot surface protection layer 30, the heat insulation layer 40, the heat resistance layer 50 and the cold surface protection layer 60 is cut according to the size of the heat insulation covering required by the component and the thickness of the heat insulation layer 40 and the heat resistance layer 50 required, and the cutting method is a conventional means in the art, which is not limited in the embodiment).

[0037] Step two, the hot face protective layer 30 and the cold face protective layer 60 are cleaned with ethyl acetate before use and dried; the hot face protective layer 30 is placed on the workbench plane (specifically: the side of the hot face protective layer 30 with protrusions is placed downward), and the heat insulation layer 40 and the heat resistance layer 50 are sequentially attached to the end face of the hot face protective layer 30; then, the welding part composed of the hot face protective layer 30, the heat insulation layer 40 and the heat resistance layer 50 is embedded into the cold face protective layer 60 (if the edge material is too much to be embedded, the outer edge of the cold face protective layer 60 can be appropriately trimmed), and then the outer circle of the hot face protective layer 30 is folded inward to form a package for the cold face protective layer 60 (after folding, a hammer can be used to knock the folded part to ensure tightness); finally, check whether the hot face protective layer 30, the heat insulation layer 40, the heat resistance layer 50 and the cold face protective layer 60 are misaligned, abnormally bulged or have other problems, and if there is no abnormality, weld the connection between them (i.e. between the hot face protective layer 30 and the cold face protective layer 60); the welding process requires: using double-row staggered welding method, welding point spacing 6±2mm, welding point indentation diameter 1±0.5mm; before each start of the welding machine, a sample of the same structure and thickness needs to be welded for 5 points, and after passing the tearing test, formal welding is carried out. The edges of the hot face protective layer 30 and the cold face protective layer 60 after welding are ground and deburred.

[0038] Step three, first brush the transition layer 20 on the surface of the hot face protective layer 30 (i.e. the side away from the heat insulation layer 40). Then, use multiple coating process to brush the ablative layer 10 on the surface of the transition layer 20, the multiple coating process of the ablative layer 10 is as follows: the thickness of the ablative layer 10 is 0.8mm, which is divided into 8 times of coating, and the thickness of each coating is 0.1mm, at the same time, after each layer is coated, it is dried and cured according to the requirements, to ensure that the previous layer is completely cured before the next layer is constructed; during the coating process of the ablative layer 10 and the transition layer 20, the construction environment temperature is 25℃, the component surface temperature is 30℃, the air humidity during the coating process is not more than 90%, the air flow of the coating site is maintained and the wind speed is not more than 5m / s. Finally, the heat-insulating composite material is obtained.

[0039] Example 3:

[0040] A method for preparing a composite heat-insulating material, see Figure 1As shown, the thermal insulation composite comprises, in sequence, an ablative layer 10, a transition layer 20, a hot-face protection layer 30, a thermal insulation layer 40, a thermal resistance layer 50, and a cold-face protection layer 60; wherein the thickness of the ablative layer 10 is 1.0 mm; the ablative layer 10 adopts an intumescent fire retardant coating, which comprises a film-forming substance, a flame retardant, and a functional filler, and the mass ratio among the film-forming substance, the flame retardant, and the functional filler is 3:10:3; wherein the film-forming substance is a high-elasticity polyurethane polymer (wherein the high-elasticity polyurethane polymer is polymerized from one or both of polycaprolactone diol and polyether diol and aliphatic polyisocyanate HDI); the flame retardant is composed of ammonium polyphosphate, pentaerythritol, and melamine, and the mass ratio among them is 8:7:4; and the functional filler is composed of nano-sized aluminum hydroxide, expanded graphite, and ultra-fine ceramic hollow microbeads (the average particle diameter of the ultra-fine ceramic hollow microbeads is 50 μm, and the melting point thereof is not lower than 1600℃), and the mass ratio among them is 10:5:8.

[0041] The thickness of the transition layer 20 is 60 μm, and the transition layer 20 adopts an epoxy primer. The thickness of the hot-face protection layer 30 (under the flat state of the hot-face protection layer 30) is 0.1 mm; the hot-face protection layer 30 adopts a metal embossed titanium foil structure, that is, an array of protrusions is arranged on the surface of the flat titanium foil structure (refer to Figure 2 As shown, the protrusions of the hot-face protection layer 30 are directed towards the transition layer 20); the shape of the protrusions adopts a water-drop shape; the diameter of the protrusions is 2.5 mm, and the height thereof is 1.0 mm; the distance between two adjacent protrusions is 8 mm; and the number of the protrusions per unit area of the hot-face protection layer 30 is 1.5x10 4 .

[0042] The thickness of the thermal insulation layer 40 is 5 mm, and the thermal insulation layer 40 adopts a basalt fiber reinforced silica aerogel felt; wherein the diameter of the basalt fiber is not greater than 6 μm, the mass ratio between the basalt fiber and the silica aerogel is 1:1, and the thermal conductivity of the basalt fiber reinforced silica aerogel felt at room temperature is 0.017 W / (m•K); the bulk density of the basalt fiber reinforced silica aerogel felt is 160 kg / m 3 , the bulk density of the preform formed by the basalt fiber is 80 kg / m 3 , and the bulk density of the silica aerogel is 80 kg / m 3The thickness of the heat resistance layer 50 is 5 mm; the heat resistance layer 50 adopts a phase change material, the phase change material is composed of a phase change raw material and a matrix material, the phase change raw material is a microcapsule, the average particle size of the microcapsule is 70 μm, wherein the encapsulating material of the microcapsule is a mixture of melamine, formaldehyde and urea, the mass ratio of melamine, formaldehyde and urea in the encapsulating material is 10:30:5; the phase change core of the microcapsule is paraffin, the mass ratio between the encapsulating material (i.e. melamine formaldehyde resin) and paraffin is 6:1; the matrix material is epoxy resin, the mass ratio between the epoxy resin (matrix material) and the microcapsule (phase change raw material) is 1:8; the phase change temperature of the phase change material is 120℃, the density is 1.3 g / cm 3 , and the phase change enthalpy value is 260 J / g. The thickness of the cold surface protection layer 60 is 0.1 mm, and the cold surface protection layer 60 is a flat and smooth titanium foil.

[0043] The specific preparation method is as follows:

[0044] Step one, prepare the coating of the anti-ablation layer 10, the transition layer 20 (i.e. uniformly mix the raw materials of the anti-ablation layer 10 according to the above formula to obtain the anti-ablation layer 10 coating, and the transition layer 20 coating can adopt existing products in the art) and the blank of the hot surface protection layer 30, the heat insulation layer 40, the heat resistance layer 50 and the cold surface protection layer 60 (the hot surface protection layer 30 can be embossed by pressing the existing flat and smooth titanium foil with a thickness size according to the above size; the heat insulation layer 40 is prepared according to the above ratio of basalt fiber and silica aerogel to prepare a basalt fiber reinforced silica aerogel felt, and the preparation method adopts the existing preparation method of fiber reinforced aerogel felt; the heat resistance layer 50 is uniformly mixed with each material according to the above ratio to prepare the heat resistance layer 50; and the cold surface protection layer 60 adopts an existing titanium foil with a composite thickness size), and the blank is cut (i.e. the blank of the hot surface protection layer 30, the heat insulation layer 40, the heat resistance layer 50 and the cold surface protection layer 60 is cut according to the size of the heat insulation layer 40 and the thickness of the heat insulation layer 40 required for the heat insulation of the component, and the cutting method is a conventional means in the art, which is not limited in the embodiment).

[0045] Step two, the hot surface protective layer 30 and the cold surface protective layer 60 are cleaned with ethyl acetate before use and dried; the hot surface protective layer 30 is placed on the workbench plane (specifically: the side of the hot surface protective layer 30 with protrusions is placed downward), and the heat insulation layer 40 and the heat resistance layer 50 are sequentially attached to the end surface of the hot surface protective layer 30; then, the welding part composed of the hot surface protective layer 30, the heat insulation layer 40 and the heat resistance layer 50 is embedded into the cold surface protective layer 60 (if the edge material is too much to be embedded, the outer edge of the cold surface protective layer 60 can be properly trimmed), and then the outer circle of the hot surface protective layer 30 is folded inward to form a package for the cold surface protective layer 60 (after folding, a hammer can be used to knock the folded part to ensure tightness); finally, check whether the hot surface protective layer 30, the heat insulation layer 40, the heat resistance layer 50 and the cold surface protective layer 60 are misaligned, abnormally bulged or have other problems, and if there is no abnormality, weld the connection between them (i.e. between the hot surface protective layer 30 and the cold surface protective layer 60), the welding process requires: using 3 rows of staggered welding method, the welding point spacing is 6±2mm, and the welding point indentation diameter is 1±0.5mm; before each start of the welding machine, 5 sample points of the same structure and thickness need to be tested by tearing and passing the inspection before formal welding. The edges of the hot surface protective layer 30 and the cold surface protective layer 60 after welding are ground and deburred.

[0046] Step three, first brush the transition layer 20 on the surface of the hot surface protective layer 30 (i.e. the side away from the heat insulation layer 40). Then, use multiple coating process to brush the ablative layer 10 on the surface of the transition layer 20, the multiple coating process of the ablative layer 10 is as follows: the thickness of the ablative layer 10 is 1.0mm, which is divided into 5 times of coating, and the thickness of each coating is 0.2mm, at the same time, after each layer is coated, dry and solidify according to the requirements, and ensure that the previous layer is completely solidified before the next layer is constructed; during the coating process of the ablative layer 10 and the transition layer 20, the construction environment temperature is 35℃, the component surface temperature is 40℃, the air humidity during the coating process is not more than 90%, the air flow of the coating site is maintained and the wind speed is not more than 5m / s. Finally, the heat insulation composite material is obtained.

[0047] Comparative example 1:

[0048] A kind of heat insulation composite material, the heat insulation composite material includes ablative layer, transition layer, hot surface protective layer, heat insulation layer, heat resistance layer and cold surface protective layer in turn;Wherein, the thickness, material, etc. of the ablative layer, the transition layer, the heat insulation layer, the heat resistance layer, the cold surface protective layer are consistent with those in example 2, the thickness of the hot surface protective layer is 0.06mm, and the hot surface protective layer adopts flat and smooth metal titanium foil.

[0049] The preparation method of the above heat insulation composite material is basically consistent with the preparation method in example 2, the difference is that in step one, the blank of the hot surface protective layer is directly obtained by using the existing smooth titanium foil with the required composite thickness.

[0050] Comparative Example 2

[0051] A thermal insulation composite material, which comprises, in sequence, an ablative layer, a transition layer, a hot face protection layer, a first thermal resistance layer and a cold face protection layer; wherein the thicknesses, materials, etc. of the ablative layer, the transition layer, the hot face protection layer and the cold face protection layer are consistent with those in Example 2; the first thermal resistance layer has a thickness of 6 mm, and is made of basalt fiber reinforced silica aerogel felt, the basalt fiber has a diameter of not more than 6 μm, the mass ratio of the basalt fiber to the silica aerogel is 1:0.85, and the thermal conductivity of the basalt fiber reinforced silica aerogel felt at room temperature is 0.018 W / (m•K); the bulk density of the basalt fiber reinforced silica aerogel felt is 163.24 kg / m 3 , the bulk density of the preform formed by the basalt fiber is 88.24 kg / m 3 , and the bulk density of the silica aerogel is 75 kg / m 3 .

[0052] The preparation method of the above thermal insulation composite material is generally consistent with the preparation method in Example 2, except that in Step 1, only the blank of the first thermal resistance layer is cut, and the blanks of the thermal insulation layer 40 and the thermal resistance layer 50 are not cut; in Step 2, when the composite is laid up, the first thermal resistance layer is also laid up between the hot face protection layer and the cold face protection layer.

[0053] Comparative Example 3

[0054] A thermal insulation composite material, which comprises, in sequence, an ablative layer, a transition layer, a hot face protection layer, a second thermal resistance layer and a cold face protection layer; wherein the thicknesses, materials, etc. of the ablative layer, the transition layer, the hot face protection layer and the cold face protection layer are consistent with those in Example 2; the second thermal resistance layer has a thickness of 6 mm; the second thermal resistance layer is made of a phase change material, the phase change material is composed of a phase change raw material and a matrix material, the phase change raw material is a microcapsule, the average particle size of the microcapsule is 60 μm, wherein the encapsulating material of the microcapsule is a mixture of melamine, formaldehyde and urea, the mass ratio of melamine, formaldehyde and urea in the encapsulating material is 10:25:3; the phase change core of the microcapsule is paraffin, and the mass ratio between the encapsulating material (i.e. melamine formaldehyde resin) and paraffin is 6:1; the matrix material is epoxy resin, and the mass ratio between the epoxy resin (matrix material) and the microcapsule (phase change raw material) is 1:6; the phase change temperature of the phase change material is 110℃, the density is 1.2 g / cm 3 , and the phase change enthalpy value is 240 J / g.

[0055] The preparation method of the above-mentioned thermal insulation composite material is basically consistent with the preparation method in Example 2, except that in step one, only the blanking of the second thermal resistance layer is performed, and the blanking of the thermal insulation layer 40 and the thermal resistance layer 50 is not performed; in step two, when the composite is performed, the second thermal resistance layer is only laid between the hot surface protection layer and the cold surface protection layer.

[0056] Comparative Example 4:

[0057] A preparation method of a composite thermal insulation material, the thermal insulation composite material sequentially comprises an anti-ablation layer, a transition layer, a hot surface protection layer, a thermal insulation layer, a thermal resistance layer and a cold surface protection layer; wherein the thickness, material and the like of the transition layer, the hot surface protection layer, the thermal insulation layer, the thermal resistance layer and the cold surface protection layer are consistent with those in Example 2; the thickness of the anti-ablation layer is 0.8 mm; the anti-ablation layer adopts an intumescent fire retardant coating, the intumescent fire retardant coating comprises a film-forming substance, a flame retardant and a functional filler, and the mass ratio between the film-forming substance, the flame retardant and the functional filler is 2.5:8:2; wherein the film-forming substance is a high-elasticity polyurethane polymer (wherein the high-elasticity polyurethane polymer is polymerized from one or both of polycaprolactone diol and polyether diol and aliphatic polyisocyanate HDI); the flame retardant is composed of ammonium polyphosphate, pentaerythritol and melamine, and the mass ratio among them is 6:5:3; the functional filler is composed of expanded graphite and superfine ceramic hollow microbeads (the average particle size of the superfine ceramic hollow microbeads is 35 μm, and the melting point thereof is not less than 1600℃), and the mass ratio between them is 3:5.

[0058] The preparation method of the above-mentioned thermal insulation composite material is basically consistent with the preparation method in Example 2, except that in the anti-ablation layer coating preparation process in step one, the functional filler of nano-sized aluminum hydroxide is not added.

[0059] The thermal insulation composite material samples in Examples 1-3 and Comparative Examples 1-4 are respectively fixed on the fixture in the inner cavity of the heating equipment, three thermocouples are arranged on the cold surface of the sample, and the three thermocouples are uniformly distributed on the cold surface of the sample, the cold surface temperature of the corresponding sample is obtained when the ambient temperature is 25 degrees Celsius (the remaining test conditions are consistent) and the hot surface temperature is 800℃, the test time is 300s, and the test results are as follows:

[0060]

[0061] As shown in the above table: using the specific anti-ablation layer, transition layer, hot surface protection layer, heat insulation layer, heat resistance layer, cold surface protection layer structure combination of the specific material combination of the corresponding structure layer, the fireproof and heat insulation performance of the composite material can be effectively improved. Under the action of the hot surface temperature of 800℃ for a long time (i.e. 300s), the average temperature of the cold surface of the heat insulation composite material prepared in the application is not more than 60℃, which is obviously lower than that of the composite materials prepared in Comparative Examples 1-4; at the same time, the temperature difference of each temperature measuring point of the composite material prepared in the application is small, which proves that the structure of the application can uniformly dissipate heat and there is no temperature aggregation point, while the temperature deviation of the temperature measuring points of the composite materials in Comparative Examples 1-4 is large, which also indirectly proves that the interlayer heat insulation effect of the application is good.

Claims

1. A method of preparing a composite thermal insulation material, characterized by: The composite thermal insulation material comprises, in sequence, an anti-ablation layer, a transition layer, a hot surface protection layer, a thermal insulation layer, a thermal resistance layer and a cold surface protection layer; the anti-ablation layer is made of intumescent fire retardant paint, the transition layer is made of primer, the hot surface protection layer and the cold surface protection layer are made of metal titanium foil, the thermal insulation layer is made of aerogel felt, and the thermal resistance layer is made of phase change material. The thickness of the heat resistance layer is 2-5 mm; the phase change material is composed of phase change raw material and base material, the phase change raw material is microcapsule, the particle size of the microcapsule is 10-100 μm, the encapsulating material of the microcapsule is a mixture of melamine, formaldehyde and urea, and the phase change core of the microcapsule is paraffin; the base material is epoxy resin; the phase change temperature of the phase change material is 95-120 ℃, the density is 1.0-1.3 g / cm 3 , and the phase change enthalpy is 220-260 J / g; the thickness of the hot surface protection layer is 0.03-0.1 mm; the hot surface protection layer adopts a metal embossed titanium foil structure, i.e. an array of protrusions is arranged on the surface of a flat titanium foil structure; the shape of the protrusions is any one of rice grain shape, pearl shape and water drop shape; the diameter of the protrusions is 1-2.5 mm, and the height is 0.4-1.0 mm; the distance between two adjacent protrusions is 4-8 mm; the number of protrusions per unit area in the hot surface protection layer is 1.5x10 4 -6x10 4 ​ The specific preparation method comprises the following steps: Step 1: preparing the anti-ablation layer, the transition layer coating, and the blank of the hot surface protection layer, the thermal insulation layer, the thermal resistance layer and the cold surface protection layer according to requirements, and cutting the blank; Step 2: placing the hot surface protection layer on the working table plane, and sequentially attaching the thermal insulation layer and the thermal resistance layer to the end surface of the hot surface protection layer; then, embedding the welding part composed of the hot surface protection layer, the thermal insulation layer and the thermal resistance layer into the cold surface protection layer, folding the outer circle of the hot surface protection layer to form a coating for the cold surface protection layer, and welding the connection part of them; Step 3: first, brushing the transition layer on the surface of the hot surface protection layer; then, using a multiple brushing process to brush the anti-ablation layer on the surface of the transition layer to obtain the composite thermal insulation material.

2. A method of preparing a composite thermal insulation material according to claim 1, characterized in that: The thickness of the anti-ablation layer is 0.6-1.0 mm; the intumescent fire retardant paint comprises a film-forming substance, a flame retardant and a functional filler, and the mass ratio among the film-forming substance, the flame retardant and the functional filler is 2-3:6-10:1-3; wherein the film-forming substance is a high-elasticity polyurethane polymer; the flame retardant is composed of ammonium polyphosphate, pentaerythritol and melamine, and the mass ratio among them is 5-8:4-7:2-4; and the functional filler is composed of nano aluminum hydroxide, expanded graphite and superfine ceramic hollow microbeads, and the mass ratio among them is 5-10:2-5:3-8.

3. A method of producing a composite thermal insulation material according to claim 1 or 2, characterized in that: The thickness of the transition layer is 40-60 μm, and the transition layer is made of epoxy primer.

4. A method of producing a composite thermal insulation material according to claim 3, characterized in that: The thickness of the thermal insulation layer is 2-5 mm, and the thermal insulation layer is made of basalt fiber reinforced silica aerogel felt; wherein the diameter of the basalt fiber is not greater than 6 μm, the mass ratio of the basalt fiber to the silica aerogel is 1:0.78-1, and the thermal conductivity coefficient of the basalt fiber reinforced silica aerogel felt at room temperature is 0.017-0.020 W / (m•K).

5. A method of producing a composite thermal insulation material according to claim 4, characterized in that: The bulk density of the basalt fiber reinforced silica aerogel felt is 150-170 kg / m 3 The bulk density of the preform formed by the basalt fiber is 80-90 kg / m 3 The bulk density of the silica aerogel is 70-80 kg / m 3 .

6. The method of claim 1, wherein: The mass ratio between the epoxy resin and the microcapsule is 1:1-15; the mass ratio between the encapsulating material of the microcapsule and the paraffin is 6:1; and the mass ratio of melamine to formaldehyde urea in the encapsulating material is 10:20-30:1-5.

7. A method of preparing a composite thermal insulation material according to claim 3, characterized in that: The thickness of the cold surface protection layer is 0.03-0.1 mm, and the cold surface protection layer is a flat and smooth metal titanium foil.

8. The method of claim 1, wherein: In step 2, the hot surface protection layer and the cold surface protection layer are cleaned with ethyl acetate before use and dried; and the welding process in step 2 requires that 1-3 rows of welding are used, the welding point spacing is 6±2 mm, and the welding point indentation diameter is 1±0.5 mm.

9. The method of claim 1, wherein: The multiple brushing process of the anti-ablation layer is as follows: the thickness of the anti-ablation layer is K, and the anti-ablation layer is brushed N times, and the thickness of each brushing is K / N; meanwhile, after each layer is brushed, drying and curing are performed according to requirements, and the next layer can be constructed only after the previous layer is completely cured.

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