Fireproof composite insulation board with thermal stress buffering and preparation method

Abstract

The present application relates to the technical field of building thermal insulation composite materials, in particular to a fireproof composite insulation board with thermal stress buffering and a preparation method, comprising a metal surface layer, an inorganic thermal insulation core material and a bonding transition layer arranged between the metal surface layer and the inorganic thermal insulation core material, wherein the bonding transition layer is formed by curing of a full-inorganic nano-modified material, and the thermal expansion coefficient of the cured bonding transition layer is between the thermal expansion coefficients of the metal surface layer and the inorganic thermal insulation core material, thereby forming a stepwise decreasing gradient transition structure from the metal surface layer to the inorganic thermal insulation core material through the bonding transition layer, and effectively buffering the alternating thermal stress at the interface. The present application solves the problem of thermal stress failure at the interface of metal and inorganic materials by gradient matching design of the thermal expansion coefficient, and the bonding strength retention rate is still above 85% after 100 times of cold and hot cycles, and the present application has A-grade fireproof performance and wide temperature range stability, and can be widely applied to the large-scale production of building exterior wall fireproof and thermal insulation composite boards.

Description

Technical Field

[0001] This invention relates to a fireproof composite insulation board with thermal stress buffering and its preparation method, particularly to a fireproof composite insulation board with thermal stress buffering and its preparation method, belonging to the technical field of building insulation composite materials. Background Technology

[0002] With the continuous upgrading of domestic building energy conservation and fire protection standards, high-rise buildings, public buildings, and underground enclosed spaces are required to use Class A non-combustible building insulation materials. Organic insulation materials are gradually being restricted from use due to their poor flame retardancy, high-temperature smoke toxicity, and low fire resistance limit. Class A inorganic insulation materials have become the mainstream application products in the industry.

[0003] Metal-faced composite inorganic insulation core panels, combining structural strength, decorative effect, thermal insulation, and fire resistance, represent a core development category in current exterior wall insulation projects. However, the coefficient of thermal expansion of aluminum in these panels is approximately 2310 °C, while that of conventional inorganic silicate insulation materials is only 5-810 °C, a significant difference. Under extreme temperature variations throughout the year, diurnal temperature variations, and alternating high and low temperatures, the expansion and contraction of the metal surface layer and the inorganic core material are asynchronous, continuously generating alternating thermal stress at the bonding interface. This ultimately leads to bulging, delamination, cracking, and detachment of the panel interface, drastically shortening its service life and seriously affecting the safety and durability of building exterior wall insulation projects.

[0004] Existing composite board bonding systems are mainly divided into two categories: organic bonding systems and ordinary inorganic bonding systems. Organic adhesives have poor temperature resistance, are prone to aging and decomposition at high temperatures, release toxic fumes when burned, cannot meet Class A fire protection requirements, and suffer severe attenuation of bonding strength after long-term thermal cycling. Conventional inorganic phosphate and silicate adhesives only focus on initial bonding strength and do not make specific adaptation designs for the difference in thermal expansion coefficients between metal and inorganic core materials, thus failing to effectively buffer interfacial thermal stress and exhibiting poor temperature change stability.

[0005] Among the existing published patents, CN112480828B discloses an inorganic insulation board composite adhesive, mainly addressing the problem of insufficient bonding strength of inorganic materials themselves; CN119505782A discloses a nano-modified inorganic adhesive, which only improves the hardness and wear resistance of the adhesive. None of these existing technologies solve the interfacial failure problem of metal-inorganic composite panels from the core perspectives of matching the coefficient of thermal expansion gradient and buffering interfacial thermal stress, and they also cannot meet the bonding requirements of novel lightweight, high-porosity inorganic insulation core materials.

[0006] Therefore, there is an urgent need for a fireproof composite insulation board with thermal stress buffering and its preparation method to solve the above-mentioned problems. Summary of the Invention

[0007] The purpose of this invention is to provide a fireproof composite insulation board with thermal stress buffering and its preparation method. Through a gradient matching design of thermal expansion coefficients, the thermal expansion coefficient of the bonding transition layer after curing is precisely controlled between the metal surface layer and the inorganic insulation core material, forming a progressively decreasing gradient transition structure that effectively buffers the alternating thermal stress at the interface. At the same time, a high-strength chemical bonding interface is constructed using all-inorganic nano-modified materials, taking into account Class A fire resistance, wide temperature range stability, and bonding ability to adapt to multiple specifications of core materials, thus solving the industry problems of poor durability and insufficient safety of existing products.

[0008] To achieve the above objectives, the main technical solution adopted by the present invention includes: a fireproof composite insulation board with thermal stress buffer and a preparation method thereof, comprising a metal surface layer, an inorganic insulation core material and an adhesive transition layer disposed between the metal surface layer and the inorganic insulation core material; The bonding transition layer is formed by curing an all-inorganic nano-modified material. After curing, the coefficient of thermal expansion of the bonding transition layer is between that of the metal surface layer and the inorganic thermal insulation core material, forming a gradually decreasing gradient transition structure from the metal surface layer to the bonding transition layer and then to the inorganic thermal insulation core material, which is used to buffer the alternating thermal stress at the interface.

[0009] Preferably, the curing thermal expansion coefficient of the bonding transition layer is 10 / ℃~18 / ℃, and the curing thickness is 0.5mm~3mm; the metal surface layer is anodized aluminum alloy thin plate with high surface flatness, strong adhesion, and excellent corrosion resistance, and a thermal expansion coefficient of 23 / ℃; the inorganic thermal insulation core material is expanded perlite board with a density of 150kg / m³~200kg / m³ or 240kg / m³~320kg / m³, and a thermal expansion coefficient of 5 / ℃~8 / ℃.

[0010] Preferably, the inorganic nano-modified material used to prepare the bonding transition layer is composed of the following inorganic components in parts by weight: 60-100 parts sodium silicate solution, 1-5 parts magnesium oxide powder, 5-20 parts nano silica, 3-15 parts nano alumina, 10-30 parts 1200 mesh micro silica powder, and 5-20 parts deionized water.

[0011] Preferably, the sodium silicate solution has a modulus of 3.0 to 3.8 and a Baumé degree of 45 to 50B, balancing system stability and curing adhesion performance; the average particle size of the nano-silica is 10 to 100 nm; the average particle size of the nano-alumina is 20 to 80 nm, and the nano-sized particles can fully fill the micropores, improving interfacial bonding and thermal stability; the microsilica powder has a mesh size of 1200 to 3000 mesh, and high-mesh microsilica powder has high pozzolanic activity, which can optimize the density and thermal expansion compatibility of the adhesive layer.

[0012] Preferably, the inorganic nano-modified material raw material further includes 0.5 to 3 parts by weight of inorganic fiber, wherein the inorganic fiber is selected from at least one of aluminum silicate fiber and glass fiber, which can further improve the crack resistance and overall tensile strength of the adhesive layer.

[0013] Preferably, the preparation steps of the inorganic nanomaterial include: S1: Sodium silicate solution aging treatment: Place the sodium silicate solution that meets the parameter requirements in a sealed container and let it stand at a constant temperature of 40~60℃ for 12~24h to eliminate internal stress in the solution and stabilize the colloidal system to obtain an aged sodium silicate solution. S2: Pre-dispersion of nanoparticles: Nano-silica, nano-alumina and some deionized water are mixed and dispersed in a high-speed disperser at a speed of 1000~3000r / min for 20~60min to completely solve the problem of nanoparticle agglomeration and prepare a uniform and stable nanoparticle dispersion. S3: Mixing and blending: Under the condition of uniform stirring at 500~1500r / min, add nano powder dispersion, micro silica powder, magnesium oxide powder and remaining deionized water to the hydrated sodium silicate solution in sequence, and continue stirring for 30~90min until the system is free of agglomeration, free of layering and uniformly mixed. S4: Room temperature aging: The uniformly mixed slurry is left to stand at room temperature for 1-3 hours to release slurry bubbles and stabilize reaction activity, finally obtaining inorganic nano-bonding transition layer material.

[0014] A method for preparing a fire-resistant composite insulation board with thermal stress buffer as described in any one of claims 1 to 6, comprising the following steps: Inorganic nano-bonding transition layer slurry is applied to the inner surface of the metal surface layer or the surface of the inorganic thermal insulation core material. After the boards are stacked, they are hot-pressed and cured for 1h to 4h under a pressure of 0.5MPa to 2MPa and a temperature of 100℃ to 200℃ to form a gradient transition layer with a thermal expansion coefficient between the two, thus obtaining a fireproof composite thermal insulation board with a thermal stress buffer gradient bonding layer.

[0015] Preferably, the entire board is made of inorganic composite material, and its combustion performance meets the GB8624A non-combustible standard.

[0016] Preferably, the inorganic thermal insulation core material is compatible with both lightweight (150~200kg / m²) and conventional (240~320kg / m²) expanded perlite boards, and the bonding transition layer nanofiller forms molecular-level chemical bonds within the pores of the core material to improve the interfacial bonding stability.

[0017] This invention has at least the following beneficial effects: 1. This invention uses a synergistic compounding of nano-silica, nano-alumina, and highly active microsilica powder to precisely control the thermal expansion coefficient of the bonding transition layer, forming a gradient transition layer between the metal surface layer and the inorganic core material. This layer absorbs and buffers the thermal stress at the interface of alternating hot and cold temperatures, completely solving the problems of bulging, delamination, and cracking failure of the board. After 100 cycles of hot and cold testing, the board's bonding strength retention rate can reach over 85%, far exceeding the retention rate of less than 50% for ordinary inorganic bonding systems. The typical thermal expansion coefficient of the bonding layer, as tested by TMA, is 14.5 / ℃, perfectly filling the numerical gap in the expansion coefficients between the metal and the core material.

[0018] 2. The bonding system of this invention contains no organic colloids or organic additives. It does not decompose, burn, or release toxic or harmful fumes at high temperatures, making it suitable for high-rise buildings, public buildings, and other high-fire-resistance environments. By adding nanoparticles, it possesses an ultra-high specific surface area and surface activity, which can form a large number of chemical bonding sites at the interface between the metal surface layer and the inorganic core material, achieving molecular-level composite bonding. This meets the bonding requirements of high-porosity lightweight inorganic core materials and solves the problems of weak bonding and easy detachment of conventional adhesives.

[0019] 3. The all-inorganic structure of this invention is stable and can maintain stable bonding performance and structural integrity in a wide temperature range environment. It is suitable for building insulation projects in various climate regions across the country. It is also compatible with both lightweight and conventional density perlite insulation core materials. It has a wide range of applications, readily available raw materials, mild preparation process, no need for complex equipment, strong parameter controllability, can be directly adapted to existing composite insulation board production lines, has low mass production cost, and high industrialization value. Attached Figure Description

[0020] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a schematic diagram of the layered structure of the composite insulation board of the present invention; Figure 2 This is a process flow diagram of the method for preparing the bonding transition layer material of the present invention; Figure 3 This is a schematic diagram illustrating the principle of gradient matching of thermal expansion coefficients in this invention. Figure 4 This is a schematic diagram of the hot pressing process for the composite insulation board of the present invention.

[0021] In the figure, 1-metal surface layer; 2-inorganic nano-bonding transition layer; 3-inorganic thermal insulation core material. Detailed Implementation

[0022] The following will describe in detail the implementation of this application with reference to the accompanying drawings and embodiments, so that the implementation process of how this application uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0023] like Figures 1-4 As shown in the figure, this embodiment provides a fireproof composite insulation board with thermal stress buffer and its preparation method, including a metal surface layer 1, an inorganic insulation core material 3, and an adhesive transition layer 2 disposed between the metal surface layer 1 and the inorganic insulation core material 3; wherein, the adhesive transition layer 2 has a curing thermal expansion coefficient of 10 / ℃~18 / ℃ and a curing thickness of 0.5mm~3mm; the metal surface layer 1 is an anodized aluminum alloy thin plate with a thermal expansion coefficient of 23 / ℃; the inorganic insulation core material 3 is an expanded perlite board with a density of 150kg / m³~200kg / m³ or 240kg / m³~320kg / m³ and a thermal expansion coefficient of 5 / ℃~8 / ℃; Furthermore, the inorganic nano-modified material used to prepare the bonding transition layer 2 is composed of the following inorganic components in parts by weight: 60-100 parts of sodium silicate solution (modulus 3.0, Baumé degree 45B), 1-5 parts of magnesium oxide powder, 5-20 parts of nano-silica, 3-15 parts of nano-alumina, 10-30 parts of 1200-mesh microsilica powder, and 5-20 parts of deionized water; the modulus of the sodium silicate solution is 3.0-3.8, and the Baumé degree is 45-50B; the average particle size of the nano-silica is 10-100 nm; the average particle size of the nano-alumina is 20-80 nm; and the mesh size of the microsilica powder is 1200-3000 mesh. Furthermore, the inorganic nano-modified material raw materials also contain 0.5 to 3 parts by weight of inorganic fibers. The inorganic fibers are selected from at least one of aluminum silicate fiber and glass fiber, specifically using a mixture of the two fibers. The fibers form a three-dimensional tensile mesh skeleton inside the bonding transition layer 2, which significantly improves the tensile and crack resistance of the transition layer. When subjected to cold and hot stress, the fibers disperse localized concentrated stress, preventing fine lines from appearing in the transition layer itself and thus preventing delamination. Since the fibers are also inorganic materials, they do not reduce the Class A fire resistance rating of the board. The amount added is controllable, and it will not clog the pores of the core material or affect the fluidity of the slurry coating, thus balancing toughness and ease of construction. Furthermore, the preparation steps of inorganic nanomaterials include: S1: Sodium silicate solution aging treatment: Place the sodium silicate solution that meets the parameter requirements in a sealed container and let it stand at a constant temperature of 40~60℃ for 12~24h to eliminate internal stress in the solution and stabilize the colloidal system to obtain an aged sodium silicate solution. S2: Pre-dispersion of nanoparticles: Nano-silica, nano-alumina and some deionized water are mixed and dispersed in a high-speed disperser at a speed of 1000~3000r / min for 20~60min to completely solve the problem of nanoparticle agglomeration and prepare a uniform and stable nanoparticle dispersion. S3: Mixing and blending: Under the condition of uniform stirring at 500~1500r / min, add nano powder dispersion, micro silica powder, magnesium oxide powder and remaining deionized water to the hydrated sodium silicate solution in sequence, and continue stirring for 30~90min until the system is free of agglomeration, free of layering and uniformly mixed. S4: Room temperature aging: The uniformly mixed slurry is left to stand at room temperature for 1-3 hours to release slurry bubbles and stabilize reaction activity, finally obtaining inorganic nano-bonding transition layer material. The segmented process solves the problem of nanoparticle agglomeration, and maximizes the bonding activity after full dispersion; the sodium silicate is pre-cured to avoid uneven coating caused by rapid curing in the later stage; the step-by-step feeding process results in a smooth reaction, with no lumps or stratification in the slurry, and the static aging process eliminates internal air bubbles, and the transition layer after hot pressing is free of pore defects; the whole process does not require high-temperature reaction and can be completed with room temperature equipment, with low investment in production line modification and compatibility with existing insulation board coating equipment. The bonding transition layer 2 is formed by curing an all-inorganic nano-modified material. After curing, the thermal expansion coefficient of the bonding transition layer 2 is between that of the metal surface layer 1 and the inorganic thermal insulation core material 3, forming a gradually decreasing gradient transition structure from the metal surface layer 1 to the bonding transition layer 2 and then to the inorganic thermal insulation core material 3, which is used to buffer the alternating thermal stress at the interface.

[0024] A method for preparing a fireproof composite insulation board with thermal stress buffering includes the following steps: Inorganic nano-bonding transition layer slurry is applied to the inner surface of the metal surface layer 1 or the surface of the inorganic thermal insulation core material 3. The three layers of boards are aligned and stacked, and then fed into a hot press. After stacking, the boards are hot-pressed and cured for 1 to 4 hours at a pressure of 0.5 MPa to 2 MPa and a temperature of 100℃ to 200℃, forming a gradient transition layer with a thermal expansion coefficient between the two. This results in a fireproof composite insulation board with a thermal stress buffer gradient bonding layer. The medium-low temperature and low-pressure hot-pressing process does not damage the porous thermal insulation structure inside the perlite core material. The controllable pressure ensures a uniform thickness of 0.5 to 3 mm for the thin transition layer, without localized glue shortages or overflows. The high temperature accelerates the inorganic colloidal aluminosilicate reaction, quickly forming a high-strength chemical bonding interface and shortening the curing cycle of the board. The process parameters are compatible with commercially available hot-pressing composite production lines, eliminating the need for additional specialized large-scale equipment and making industrialization easier. The entire panel is made of inorganic composite material, and its combustion performance meets the GB8624 Class A non-combustible standard, completely solving the safety shortcomings of traditional organic composite insulation boards, such as flammability and the release of toxic fumes at high temperatures; it meets the mandatory Class A fire protection building specifications for high-rise buildings, underground garages, hospitals, schools, etc.; the panels will not delaminate and fall off quickly under fire conditions, the insulation structure remains intact, the fireproof and heat insulation time is extended, the fire safety level of the building is improved, and there are no obstacles to flame retardant compliance during project acceptance.

[0025] Furthermore, the inorganic insulation core material is compatible with both lightweight (150~200kg / m²) and conventional (240~320kg / m²) expanded perlite boards. The nanofiller in the bonding transition layer forms molecular-level chemical bonds within the core material pores to improve interfacial bonding stability. It is suitable for both high and low density perlite core materials, and the lightweight porous core material will not experience insufficient adhesion or detachment. The nanofiller is embedded in the pores to form an anchoring structure, which increases the tensile strength by more than 40% compared to planar bonding. High and low density core materials can be freely selected according to insulation and load requirements. One bonding formula is compatible with both substrates, greatly improving the flexibility of factory stocking and project material selection. The interface does not delaminate under long-term temperature difference conditions.

[0026] Example 1: Basic Optimal Formulation, Preparation of Adhesive Layer Material Raw material by weight: 80 parts sodium silicate solution with modulus 3.2 and Baume degree 46B, 2.5 parts magnesium oxide powder, 8 parts nano silica with an average particle size of 50nm, 8 parts nano alumina with an average particle size of 40nm, 18 parts 1200 mesh micro silica powder, and 12 parts deionized water.

[0027] Preparation steps: S1: Sodium silicate solution, aged in a sealed container at 50℃ for 18 hours; S2: Take 5 parts of deionized water and mix with nano-silica and nano-alumina, disperse at high speed of 2000r / min for 40min to prepare nano-dispersion; S3: Under stirring at 1000r / min, add nano-dispersion, silica powder, magnesium oxide, and the remaining 7 parts of deionized water in sequence, and continue stirring for 60min until homogeneous; S4: Aging at room temperature for 2 hours yields the finished adhesive transition layer material.

[0028] Example 2: Preparation and Performance Testing of Conventional Core Material Composite Insulation Board The adhesive material prepared in Example 1 was used, with a 0.8mm anodized aluminum alloy sheet as the metal surface layer and a 280kg / m expanded perlite board as the inorganic core material. A 1.5mm thick adhesive material was coated on the sheet, and after lamination, it was hot-pressed and cured at 1.0MPa and 150℃ for 2.5h. The thickness of the adhesive layer after curing was 1.0mm.

[0029] Performance testing: Fire rating: Class A; Tensile bond strength: 0.10 MPa, meeting JG / T287-2013 standard; After 100 cycles of hot and cold cycling, the board interface showed no bulging, delamination, or cracking.

[0030] Example 3: Modification with inorganic fibers to improve crack resistance Based on the formulation of Example 1, 2 parts by weight of aluminum silicate fiber were added. The remaining raw materials, preparation process, and board composite process were completely consistent with those of Example 2. The crack resistance of the adhesive layer and the overall tensile strength of the resulting board were significantly improved, and the high-temperature stability was further optimized.

[0031] Example 4: Verification of the lower limit ratio of nano-silica The amount of nano-silica added was adjusted to 5 parts, and the remaining components were finely adjusted for adaptation. The preparation and composite process were the same as in Example 2. Test results: the thermal expansion coefficient of the adhesive layer was qualified, the interface was undamaged after cold and hot cycling, and the performance met the standards.

[0032] Example 5: Verification of the upper limit ratio of nano-silica The amount of nano-silica added was adjusted to 20 parts, and the remaining components were finely adjusted for adaptation. The preparation and composite process were the same as in Example 2. Test results: The adhesive layer showed excellent density, good thermal stress buffering effect, and the board interface was stable and defect-free.

[0033] Example 6: Verification of High Mesh Count Microsilica Powder Modification Using 2000-mesh silica powder instead of 1200-mesh silica powder, with the remaining formulation and process the same as in Example 2, the resulting adhesive layer exhibited higher density, fewer micropores, and better interfacial stability after thermal cycling compared to Example 2.

[0034] Example 7: Compatibility Verification of Lightweight Core Material Using the bonding material from Example 1, a lightweight expanded perlite core material of 180 kg / m² was selected. The bonding layer coating thickness was 1.2 mm. Hot pressing at 0.8 MPa and 150℃ for 2.5 h resulted in a cured thickness of 0.8 mm. Test results: Fire resistance rating A, bonding strength met standards, interface remained intact after thermal cycling, suitable for ultra-lightweight insulation core material applications. Comparison of measured thermal expansion coefficients of bonding transition layers The bonding transition layer material prepared in Example 1 was cured at 150°C for 2.5 h to make a standard sample, and its coefficient of linear expansion in the temperature range of -20°C to 80°C was tested using a thermomechanical analyzer.

[0035] The test results are shown in Table 1. Test Project Metal surface layer (aluminum alloy) Example 1: Adhesive Transition Layer Inorganic thermal insulation core material (expanded perlite) Coefficient of thermal expansion ( / °C) 23.0 14.5 6.8 Comparison of bond strength retention rate after thermal cycling The composite boards prepared in Example 2, Comparative Example 1, and Comparative Example 3 were subjected to 100 cycles of hot and cold cycling to test the tensile bond strength before and after the cycles and to calculate the strength retention rate. The results are shown in Table 2. Group Initial tensile bond strength (MPa) Tensile bond strength (MPa) after 100 cycles Strength retention rate (%) Interface appearance Example 2 (Invention) 0.15 0.13 85% No bulges, no cracks Comparative Example 1 (pure silicate) 0.12 0.05 Approximately 42% Obvious bulging and peeling Comparative Example 3 (without microsilica powder) 0.13 0.09 Approximately 69% Microcracks appeared Comparative Example 1: Ordinary sodium silicate binder system without nano or micro silica powder Pure sodium silicate-magnesium oxide inorganic adhesive was used, without the addition of nano-silica, nano-alumina, or microsilica powder. The remaining composite process was the same as in Example 2. After thermal cycling tests, obvious bulging and localized peeling appeared at the interface of the board, indicating extremely poor thermal stress adaptability.

[0036] Comparative Example 2: Organic Binder System A commercially available building-specific organic adhesive was used to replace the adhesive layer of this invention, with the remaining processes the same as in Example 2. Under high-temperature conditions, the organic adhesive decomposes and ages, resulting in a significant decrease in adhesive strength, which fails to meet the requirements for Class A fire resistance and long-term stable use.

[0037] Comparative Example 3: System with only nanofillers and no microsilica powder The formulation only added nano-silica and nano-alumina, omitting microsilica powder; otherwise, it was the same as in Example 2. The adhesive layer lacked sufficient micro-density, resulting in localized microcracks after thermal cycling, large temperature deformation, and a significant decrease in stability.

[0038] Comparative Example 4: Microsilica powder only, no nanofillers The formulation only adds microsilica powder, omitting nano-silica and nano-alumina; otherwise, it is the same as in Example 2. Insufficient interfacial chemical bonding sites result in low initial bond strength and poor long-term temperature stability.

[0039] Comparative Example 5: Low-mesh silica powder system Using 800-mesh silica powder instead of 1200-mesh or finer silica powder, the rest is the same as in Example 2. The silica powder has insufficient activity, resulting in high porosity and poor density in the adhesive layer, and its thermal cycling stability is significantly inferior to the solution of this invention.

[0040] The above examples and comparative examples confirm that the present invention achieves multiple technical effects, such as precise control of thermal expansion coefficient, high-strength bonding, Class A fire resistance, and wide-temperature stability, through the synergistic compounding effect of nano-double fillers and high-mesh-count microsilica powder. Single fillers or conventional fillers cannot achieve the technical effects of the present invention.

[0041] like Figures 1-4 As shown in the figure, the principle of the fireproof composite insulation board with thermal stress buffer and its preparation method provided in this embodiment is as follows: The board is arranged in a three-layer composite structure, with an outer metal surface layer 1, a middle bonding transition layer 2, and an inner inorganic insulation core material 3; the bonding transition layer 2 is made of all inorganic nano-materials and cured, with a thermal expansion value between that of the metal surface layer 1 and the inorganic insulation core material 3, forming a thermal expansion gradient structure of metal surface layer 1-bonding transition layer 2-inorganic insulation core material 3; when the deformation difference occurs due to seasonal and diurnal temperature variations, the gradient bonding transition layer 2 absorbs and disperses the alternating thermal stress generated at the interface layer by layer, offsetting the tensile force caused by the asynchronous deformation of the two substrates, and avoiding interface delamination and cracking; it breaks the defect of traditional single adhesive without gradient buffer, and dissolves the interface thermal stress layer by layer through the three-layer thermal expansion gradient structure.

[0042] The specification and claims use certain terms to refer to specific components. Those skilled in the art will understand that hardware manufacturers may use different names to refer to the same component. This specification and claims do not distinguish components based on differences in name, but rather on differences in function. The term "inclusion" used throughout the specification and claims is an open-ended term and should be interpreted as including but not limited to. "Generally speaking" refers to the ability of those skilled in the art to solve the technical problem and achieve the basic technical effect within an acceptable margin of error.

[0043] It should be noted that the terms "include," "contain," or any other variations thereof are intended to cover non-exclusive inclusion, such that a product or system that includes a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a product or system. Without further limitations, the inclusion of a defined element by a statement does not exclude the presence of other identical elements in the product or system that includes that element.

[0044] The foregoing description illustrates and describes several preferred embodiments of the present invention. However, as previously stated, it should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the inventive concept described herein through the foregoing teachings or techniques or knowledge in related fields. Any modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. A fireproof composite insulation board with thermal stress buffering, characterized in that: It includes a metal surface layer (1), an inorganic thermal insulation core material (3), and an adhesive transition layer (2) disposed between the metal surface layer (1) and the inorganic thermal insulation core material (3); The bonding transition layer (2) is formed by curing an all-inorganic nano-modified material. After curing, the thermal expansion coefficient of the bonding transition layer (2) is between that of the metal surface layer (1) and the inorganic thermal insulation core material (3), forming a progressively decreasing gradient transition structure from the metal surface layer (1) to the bonding transition layer (2) and then to the inorganic thermal insulation core material (3), which is used to buffer the alternating thermal stress at the interface.

2. The fireproof composite insulation board with thermal stress buffering according to claim 1, characterized in that: The bonding transition layer (2) has a curing thermal expansion coefficient of 10 / ℃~18 / ℃ and a curing thickness of 0.5mm~3mm; the metal surface layer (1) is an anodized aluminum alloy thin plate with a thermal expansion coefficient of 23 / ℃; the inorganic thermal insulation core material (3) is an expanded perlite board with a density of 150kg / m~200kg / m or 240kg / m~320kg / m and a thermal expansion coefficient of 5 / ℃~8 / ℃.

3. A fireproof composite insulation board with thermal stress buffering according to claim 2, characterized in that: The inorganic nano-modified material used to prepare the bonding transition layer (2) is composed of the following inorganic components in parts by weight: 60-100 parts of sodium silicate solution (modulus 3.0, Baume degree 45B), 1-5 parts of magnesium oxide powder, 5-20 parts of nano silica, 3-15 parts of nano alumina, 10-30 parts of 1200 mesh micro silica powder, and 5-20 parts of deionized water.

4. A fireproof composite insulation board with thermal stress buffering according to claim 3, characterized in that: The sodium silicate solution has a modulus of 3.0 to 3.8 and a Baume degree of 45 to 50B; the average particle size of the nano-silica is 10 to 100 nm; the average particle size of the nano-alumina is 20 to 80 nm; and the mesh size of the microsilica powder is 1200 to 3000 mesh.

5. A fireproof composite insulation board with thermal stress buffering according to claim 4, characterized in that: The inorganic nano-modified material raw material also contains 0.5 to 3 parts by weight of inorganic fiber, wherein the inorganic fiber is selected from at least one of aluminum silicate fiber and glass fiber.

6. A fireproof composite insulation board with thermal stress buffering according to claim 1, characterized in that: The preparation steps of the inorganic nano-modified material include: S1: Place the sodium silicate solution in a sealed container and let it stand at a constant temperature of 40~60℃ for 12~24 hours to mature. S2: Nano-silica, nano-alumina and some deionized water are mixed and dispersed at high speed of 1000~3000r / min for 20~60min to prepare nano-powder dispersion; S3: While stirring, add nano-dispersion, micro silica powder, magnesium oxide and remaining deionized water to the hydrated sodium silicate in sequence, and continue stirring for 30-90 minutes until the slurry is uniform; S4: The mixed slurry is left to stand at room temperature for 1-3 hours to obtain an inorganic nano-binder slurry.

7. A method for preparing a fire-resistant composite insulation board with thermal stress buffer as described in any one of claims 1 to 6, characterized in that: Includes the following steps: Inorganic nano-bonding transition layer slurry is applied to the inner surface of the metal surface layer (1) or the surface of the inorganic thermal insulation core material (3). After the boards are stacked, they are hot-pressed and cured for 1h to 4h under a pressure of 0.5MPa to 2MPa and a temperature of 100℃ to 200℃ to form a gradient transition layer with a thermal expansion coefficient between the two, thus obtaining a fireproof composite thermal insulation board with a thermal stress buffer gradient bonding layer.

8. The method for preparing a fireproof composite insulation board with thermal stress buffering according to claim 7, characterized in that: The entire panel is made of inorganic composite material, and its combustion performance meets the GB8624A non-combustible standard.

9. The method for preparing a fireproof composite insulation board with thermal stress buffering according to claim 7, characterized in that: The inorganic thermal insulation core material is compatible with both lightweight (150~200kg / m) and conventional (240~320kg / m) expanded perlite boards. The bonding transition layer nanofiller forms molecular-level chemical bonds within the pores of the core material to improve the interfacial bonding stability.

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