Aerogel-containing building energy-saving and heat-insulating integrated board

Abstract

The invention relates to the technical field of building materials, and discloses a preparation method of an aerogel-containing building energy-saving thermal-insulation integrated board, which comprises the following steps: using diatomite to replace an organic silicon source; silica sol is used as a silicon source, and the molar ratio of tetraethoxysilane to water is 1: 4; mixing the wet gel with ceramic fibers, and adding epoxy resin and ammonium polyacrylate as dispersing agents; preparing aerogel slurry and a ceramic thin plate; the first section of plate heat treatment is 100 DEG C, the second section is 150 DEG C, and the third section is 200 DEG C; 500-1000 L of supercritical COO equipment is adopted; microencapsulated epoxy resin is introduced, and gaps are automatically filled when the material cracks; the vacuum degree is 10Pa, and the time is 2 hours. By means of a composite adding mode, the aerogel-containing building energy-saving and heat-preservation integrated board can keep the integrity of the structure by means of the tensile and compressive properties of the board and is not prone to cracking and deformation, and the problems that the mechanical property and the heat-preservation efficiency of a heat-preservation board are insufficient are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of building materials, and specifically to an integrated building energy-saving and heat-insulating board containing aerogel. Background Art

[0002] With the increasingly severe global energy shortage problem and the continuous improvement of people's requirements for indoor comfort in buildings, building energy conservation has become one of the key directions for the development of the building industry. Among building energy consumptions, the heat dissipated through the envelope structure (such as walls, roofs, etc.) accounts for a relatively large proportion. Therefore, the research and application of high-performance thermal insulation materials are of great significance for reducing building energy consumption.

[0003] Traditional building thermal insulation materials, such as polystyrene foam boards, rock wool boards, etc., although they can play a certain role in heat insulation to a certain extent, each has some limitations. Polystyrene foam boards have poor fire resistance, are easy to burn and release a large amount of toxic and harmful gases, posing a great safety hazard; although rock wool boards have good fire resistance, their thermal insulation performance is relatively insufficient, and they are brittle and easy to absorb water. After long-term use, the thermal insulation effect will significantly decline. At the same time, dust pollution is easily generated during the construction process, causing adverse effects on human health and the environment. Summary of the Invention

[0004] In view of the deficiencies of the prior art, the present invention provides an integrated building energy-saving and heat-insulating board containing aerogel, which solves the problems of insufficient mechanical properties and heat insulation efficiency of existing building thermal insulation materials.

[0005] To achieve the above objectives, the present invention is realized through the following technical solutions: A preparation method for an integrated building energy-saving and heat-insulating board containing aerogel, comprising the following steps: S1. Use diatomite to replace the organosilicon source. After mixing with aerogel, the thermal conductivity is reduced to 0.012 W / (m·K), and the cost is reduced by 40%; S2. Use silica sol as the silicon source, with the molar ratio of tetraethyl orthosilicate to water being 1:4, and adjust the pH to 6.7 with ammonia water; S3. Mix the wet gel with ceramic fibers, add epoxy resin and ammonium polyacrylate as dispersants, and the viscosity of the slurry is 500 - 800 mPa·s; S4. The aerogel slurry and the ceramic thin plate form a composite board through a co-extrusion die, and the dosage of the binder is reduced to 8%; S5. Heat treatment of the board: the first stage is at 100 °C for 1 hour, with the humidity ≤ 30%; the second stage is at 150 °C for 2 hours, with the humidity ≤ 20%; the third stage is at 200 °C for 3 hours, with the humidity ≤ 10%; S6. Use a 500 - 1000 L supercritical CO2 device. The supercritical conditions for ethanol are Tc = 241.15 °C and Pc = 6.38 MPa, and the drying time is shortened to 4 hours; S7. Introduce microencapsulated epoxy resin, which automatically fills the gaps when the material cracks, and extends the service life to more than 25 years. S8. The vacuum degree is 10⁻³ Pa, the time is 2 hours, and the encapsulation film uses a PET / PI composite film.

[0006] Preferably, in the S1 step, it includes: compound reinforcement by adding nano-mullite with a particle size of 50 nm and a volume ratio of 15%, and aluminosilicate fiber with a length of 12 mm and a volume ratio of 20%, which increases the tensile strength to 0.15 MPa and the compressive strength reaches 0.8 MPa.

[0007] Preferably, in the S2 step, it includes: gelation reaction: stirring at 25 °C for 4 hours to form a three-dimensional network structure, with a wet gel density of 1.2 g / cm³ and a porosity ≥ 90%.

[0008] Preferably, in the S3 step, it includes: homogenization treatment: using an ultrasonic cell disruptor with a value of 20 kHz for 30 minutes to eliminate bubbles and ensure the uniformity of the slurry.

[0009] Preferably, in the S4 step, it includes: mechanical boosting: directly pressing with a 25 MPa high-pressure hose, with a sheet thickness tolerance of ±0.5 mm and a surface density ≤ 8 kg / m².

[0010] Preferably, in the S5 step, it also includes: increasing the thermal efficiency by 40% and reducing the energy consumption to 60 kWh / m³.

[0011] Preferably, in the S6 step, it includes: post-treatment: silanization treatment with γ-methacryloxypropyltrimethoxysilane at a concentration of 0.3 wt% and curing at 120 °C for 2 hours to enhance the interfacial bonding force.

[0012] Preferably, in the S7 step, it includes: a heat-reflecting layer: a composite aluminum-based reflective film with a thickness of 50 μm, a reflectivity > 85%, and an overall thermal conductivity ≤ 0.018 W / (m·K).

[0013] Preferably, in the S8 step, it includes: quality inspection: thermal conductivity by the laser flash method with an error of ±5%; compressive strength by a universal testing machine (loading rate 10 mm / min) ≥ 0.5 MPa; hydrophobicity by a water contact angle tester ≥ 150°.

[0014] The present invention provides a building energy-saving and heat-insulating integrated board containing aerogel, which has the following beneficial effects: 1. Through the method of compound addition, the present invention enables the tensile strength of the material to be increased to 0.15 MPa, and the compressive strength can also reach 0.8 MPa. The building energy-saving and heat-insulating integrated board containing aerogel can maintain the integrity of its own structure by virtue of its tensile and compressive properties, and will not easily crack, deform, etc., solving the problems of insufficient mechanical properties and heat-insulating efficiency of the heat-insulating board.

[0015] 2. Through the homogenization treatment, the present invention achieves the effect of eliminating air bubbles and ensuring the uniformity of the slurry. Eliminating air bubbles can avoid the formation of holes due to the existence of air bubbles during the subsequent forming process of the board, which affects the structural integrity and performance of the board; ensuring the uniformity of the slurry makes the composition and performance of each part of the board consistent, improving the stability of the board quality and solving the problems of air bubbles and uneven composition in the slurry.

[0016] 3. Through the mechanical pressurization operation, the present invention achieves the effect that the thickness tolerance of the board is controlled within ±0.5 mm and the surface density ≤ 8 kg / m², reducing the unit weight of the board. This is not only beneficial to transportation, handling and other operation links, reducing the labor and material costs and improving the safety of the overall structure, but also solving the problems of poor thickness consistency and excessive surface density of the board.

[0017] 4. Through the treatment process of temperature, time and humidity control, the present invention achieves the remarkable effects of a 40% increase in thermal efficiency and a reduction in energy consumption to 60 kWh / m³. It can play a better heat-insulating role and reduce the energy consumed by the building to maintain a suitable indoor temperature. The reduction in energy consumption directly reduces the energy cost expenditure of the entire building during the production and subsequent use of the board, solving the problems of low thermal efficiency and excessive energy consumption during the heat treatment process of traditional boards.

[0018] 5. Through the setting of the heat-reflective layer, the present invention achieves the effect that the overall thermal conductivity ≤ 0.018 W / (m·K). Whether in the hot summer, a large amount of outdoor high-temperature thermal radiation is difficult to penetrate into the room, enabling the room to maintain a relatively cool environment and reducing the use frequency of refrigeration equipment such as air conditioners; in the cold winter, the indoor heat is not easily dissipated to the outside through thermal radiation, helping to maintain the warmth of the room and reducing the heating energy consumption, solving the problem of insufficient ability of traditional heat-insulating boards to block thermal radiation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a flowchart of the steps of the preparation method of the building energy-saving and heat-insulating integrated board containing aerogel proposed by the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0020] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0021] Please refer to the attached Figure 1 , the embodiment of the present invention provides a preparation method of an aerogel-containing integrated building energy-saving insulation board, including the following steps: S1. Use diatomite to replace the organosilicon source. After mixing with aerogel, the thermal conductivity is reduced to 0.012 W / (m·K), and the cost is reduced by 40%; S2. Use silica sol as the silicon source, the molar ratio of tetraethyl orthosilicate to water is 1:4, and ammonia water is used to adjust the pH to 6.7; S3. Mix the wet gel with ceramic fibers, add epoxy resin and ammonium polyacrylate as dispersants, and the slurry viscosity is 500 - 800 mPa·s; S4. The aerogel slurry and the ceramic thin plate form a composite board through a co-extrusion die, and the dosage of the binder is reduced to 8%; S5. Heat treatment of the board: the first stage: 100 °C, 1 hour, humidity ≤ 30%, the second stage: 150 °C, 2 hours, humidity ≤ 20%, the third stage: 200 °C, 3 hours, humidity ≤ 10%; S6. Use a 500 - 1000 L supercritical CO2 device, the supercritical conditions of ethanol are Tc = 241.15 °C, Pc = 6.38 MPa, and the drying time is shortened to 4 hours; S7. Introduce microencapsulated epoxy resin, which automatically fills the gaps when the material cracks, and the service life is extended to more than 25 years; S8. The vacuum degree is 10⁻³ Pa, the time is 2 hours, and the encapsulation film uses a PET / PI composite film.

[0022] Step S1 includes: adding nano-mullite with a particle size of 50 nm and a volume ratio of 15% and aluminosilicate fiber with a length of 12 mm and a volume ratio of 20% for composite reinforcement, and the tensile strength is increased to 0.15 MPa, and the compressive strength reaches 0.8 MPa.

[0023] Specifically, the main chemical component of diatomite is silicon dioxide, and its surface contains a certain amount of reactive groups such as silanol groups. During the mixing process with aerogel, these reactive groups can undergo physical adsorption and partial chemical bonding with similar reactive groups on the surface of the aerogel, making the combination between the two more compact and forming a relatively stable and continuous composite structure. This tightly bound structure helps to reduce the weak thermal conduction links that may exist at the material interface, making it more difficult for heat to transfer through the interface, thereby further inhibiting the overall thermal conduction and synergistically reducing the thermal conductivity of the material.

[0024] Nano-mullite has a small particle size and good properties such as high temperature resistance and high strength. After being mixed with aerogel and other raw materials, it can be evenly dispersed in the material system. With its own rigid structure, it plays a filling and supporting role at the microscopic level, enhancing the structural stability inside the material. The aluminosilicate fiber has a length of 12 mm and a volume ratio of 20%. It has a high aspect ratio and forms a network-like structure by intertwining with each other in the system. Acting synergistically with nano-mullite, it can effectively share the externally applied tensile and compressive forces, and transfer and disperse stress.

[0025] Through the method of compound addition, the tensile strength of the material can be increased to 0.15 MPa, and the compressive strength can also reach 0.8 MPa. In actual building application scenarios, whether it is during the installation of the board or during the long-term use of the building, under the pressure effects such as extrusion and shear caused by factors such as the self-weight of the building, wind load, and vibration, the building energy-saving insulation integrated board containing aerogel can maintain the integrity of its own structure by virtue of its own tensile and compressive properties, and will not easily crack, deform, etc., solving the problems of insufficient mechanical properties and insulation efficiency of the insulation board.

[0026] Step S2 includes: gelation reaction: stirring for 4 hours at 25 °C to form a three-dimensional network structure, wet gel density 1.2 g / cm³, porosity ≥ 90%.

[0027] Specifically, using silica sol as the silicon source, when tetraethyl orthosilicate and water are mixed at a molar ratio of 1:4 and the pH is adjusted to 6.7 with ammonia water, the silanol groups in the silica sol will undergo hydrolysis reactions in this specific pH environment. The silanol groups (Si-OH) will condense with each other and gradually form silicon-oxygen-silicon (Si-O-Si) bonds. At a temperature of 25°C, this temperature is within the appropriate reaction range, which not only ensures that the reaction can proceed at a suitable rate but also avoids adverse effects on the reaction process due to too high or too low temperature. Stir continuously for 4 hours. The stirring action enables the reactants to be fully mixed and contacted, promoting the uniform and continuous progress of the hydrolysis and polycondensation reaction. Numerous silicon-oxygen-silicon bonds are continuously connected and extended, ultimately constructing a three-dimensional network structure. During the formation of this structure, the various components are intertwined and arranged, resulting in the formation of a large number of pores inside the gel. At the same time, due to the combined action of the reaction conditions, the density of the wet gel is finally stabilized at about 1.2 g / cm³, and the porosity can reach a level of ≥90%.

[0028] Through the gelation reaction process, a wet gel with a stable three-dimensional network structure is prepared, with a density of 1.2 g / cm³ and a porosity of ≥90%. This structure endows the material with unique properties. The large number of pores makes the air content inside the material high. As a poor conductor of heat, air can effectively hinder the transfer of heat, thus bringing good heat insulation performance to the material. At the same time, the three-dimensional network structure provides a certain supporting role for the entire material, ensuring the structural integrity of the material during subsequent processing and use. It solves the problem that it is difficult to accurately control the internal microstructure of the gel when preparing aerogel-containing building energy-saving insulation integrated boards, resulting in the porosity and density not meeting the ideal insulation requirements.

[0029] The S3 step includes: homogenization treatment: using an ultrasonic cell disruptor with a value of 20 kHz for 30 minutes to eliminate bubbles and ensure the uniformity of the slurry.

[0030] Specifically, epoxy resin molecules have a certain chain structure and can adsorb on the surfaces of wet gel particles and ceramic fibers. By virtue of the steric hindrance effect, they can prevent the particles and fibers from aggregating due to approaching each other. At the same time, it has a certain compatibility with the components in the system and can stably adsorb and play a dispersing role, which is conducive to maintaining the uniformity of the system. As a polymer electrolyte, ammonium polyacrylate, after ionization in the solution, the charged groups on its molecular chain make the surfaces of wet gel particles and ceramic fibers carry the same kind of charge. Relying on the electrostatic repulsion effect, they keep each other away and avoid aggregation. Moreover, its polar groups have strong hydrophilicity and can form a hydration film on the surfaces of the particles and fibers, increasing the distance and enhancing the suspension stability, enabling them to be evenly dispersed in the system.

[0031] The ultrasonic cell disruptor operates at a frequency of 20 kHz for 30 minutes. Its working principle is based on the cavitation effect of ultrasonic waves. When ultrasonic waves propagate in the slurry, alternating compression and expansion cycles are formed. During the expansion cycle, tiny cavitation bubbles are formed in the slurry; while during the compression cycle, these cavitation bubbles will quickly collapse. When the cavitation bubbles collapse, local high temperature, high pressure, intense shock waves and microjets are generated. These extreme physical conditions can have a significant impact on the bubbles and agglomerates in the slurry. For bubbles, the intense shock waves and microjets can break the surface tension of the bubbles, causing them to break and dissipate; for the possible agglomerates, the high temperature, high pressure and microjets can break the interaction forces between the agglomerated particles, causing them to disperse. At the same time, the stirring effect of ultrasonic waves also helps various components to be more evenly distributed in the slurry.

[0032] Through homogenization treatment, the effects of eliminating bubbles and ensuring the uniformity of the slurry are achieved. Eliminating bubbles can avoid the formation of holes due to the presence of bubbles during the subsequent sheet forming process, which affects the structural integrity and performance of the sheet; ensuring the uniformity of the slurry makes the composition and performance of each part of the sheet consistent, improving the stability of the sheet quality and solving the problems of bubbles and uneven composition in the slurry.

[0033] Step S4 includes: Mechanical boosting: Direct ramming is carried out using a 25 MPa high-pressure hose. The thickness tolerance of the sheet is ±0.5 mm, and the surface density is ≤8 kg / m².

[0034] Specifically, the aerogel slurry is responsible for the main thermal insulation task, while the ceramic thin plate plays an important role in mechanical support, protection and appearance decoration. After the two are combined through the process, the sheet can not only have high thermal insulation performance, but also meet the requirements of strength, durability and aesthetics in the construction and long-term use process, becoming a building energy-saving thermal insulation material with excellent comprehensive performance. When ramming the combination of aerogel slurry and ceramic thin plate with a high pressure of 25 MPa through a hose, the high pressure will exert a uniform and powerful external force on the material. This external force will cause the aerogel slurry to be strongly squeezed in the mold (the space where it acts together with the ceramic thin plate), prompting the components in the slurry to be further closely arranged. For a material like aerogel with a porous structure, the high pressure can compact its originally relatively loose pore structure to a certain extent, reduce the proportion of pore volume, make the contact between components closer, and thus improve the overall density.

[0035] Through supercharging operation, the thickness tolerance of the board is controlled within ±0.5 mm and the surface density is ≤8 kg / m². The precise control of the board thickness tolerance within a small range enables each aerogel-containing building energy-saving insulation integrated board produced to maintain relatively consistent specifications and dimensions, meet the strict requirements for board size accuracy in building construction, facilitate construction and installation, and ensure the flatness and sealing of the entire building envelope structure. The achievement of the index of surface density ≤8 kg / m² means that while ensuring that the board has sufficient insulation, mechanical and other properties, the unit weight of the board is reduced. This not only facilitates transportation, handling and other operation links, reduces labor and material costs, but also reduces the load on the building structure in building applications, improves the safety of the overall structure, and solves the problems of poor thickness consistency and excessive surface density of the board.

[0036] Step S5 also includes: the thermal efficiency is increased by 40% and the energy consumption is reduced to 60 kWh / m³.

[0037] Specifically, a thermal curing furnace can be used for heat treatment. The temperature and humidity control process is used in the heat treatment link of the board, which plays a key role in improving the insulation performance, structural stability and overall quality of the aerogel-containing building energy-saving insulation integrated board. During the treatment process at 100°C for 1 hour and humidity ≤30% in the first stage, the low temperature and humidity environment will first cause volatile substances such as moisture inside the board to slowly and gently volatilize, and at the same time allow the components in the material to initially adjust and stabilize at the molecular level, avoiding the generation of internal stress due to rapid temperature and humidity changes and affecting the structural integrity. This stage lays the foundation for subsequent further treatment, enabling the material to better adapt to the subsequent temperature increase process.

[0038] Entering the second stage at 150°C for 2 hours and humidity ≤20%, the increase in temperature promotes the intensification of molecular motion inside the material, and the chemical bonding, physical combination and other interactions between various components are further optimized. Some originally unstable structures gradually become stable. For example, the combination between aerogel and other added components becomes closer, and the synergistic effect between reinforcing materials such as ceramic fibers and the matrix is also strengthened. Moreover, with the further reduction of humidity, the moisture is basically removed, reducing the possible heat conduction channels caused by the presence of moisture and improving the basic conditions for insulation performance.

[0039] In the third stage at 200°C for 3 hours with a humidity ≤ 10%, the higher temperature enables the full release of the residual stress inside the material, and the overall structure of the material reaches a more stable and dense state. During this process, the interaction between components continues to be optimized, the pore structure of the aerogel completes its final stabilization under the thermal effect, and the interfacial bonding between the ceramic thin plate and the aerogel and other parts becomes stronger. As a result, the loss links during the heat transfer inside the plate are reduced as a whole, enabling heat to be more effectively blocked on one side of the plate, thus enhancing the thermal efficiency. From the perspective of energy consumption, this method of staging, gradually increasing the temperature, and strictly controlling the humidity, compared with the traditional methods of continuous heating at high temperature for a long time or irregular heat treatment, avoids unnecessary energy consumption behaviors such as overheating and repeatedly adjusting the temperature, precisely utilizes heat to prompt the material to reach the ideal state, and achieves the effect of reducing energy consumption to 60 kWh / m³.

[0040] Through the treatment process of controlling temperature, time, and humidity, significant effects of a 40% increase in thermal efficiency and a reduction in energy consumption to 60 kWh / m³ are achieved. The increase in thermal efficiency means that during the use of the building, the building energy-saving insulation integrated board containing aerogel can more effectively block the heat transfer. Whether it is to keep the indoor heat in winter or block the external heat from entering the room in summer, it can play a better role in heat insulation, reducing the energy consumed by the building to maintain a suitable indoor temperature. The reduction in energy consumption directly reduces the energy cost expenditure of the entire building during the production and subsequent use stages of the board, solving the problems of low thermal efficiency and high energy consumption during the heat treatment of traditional boards.

[0041] The S6 step includes: post-treatment: silanization treatment, γ-methacryloxypropyltrimethoxysilane, concentration 0.3 wt%, curing at 120°C for 2 hours to enhance the interfacial bonding force.

[0042] Specifically, when supercritical CO2 is at a specific critical temperature (Tc = 241.15°C) and critical pressure (Pc = 6.38 MPa), it has both the high diffusivity of a gas and the strong dissolution ability of a liquid. In the supercritical state created by a 500 - 1000 L supercritical CO2 device, CO2 can quickly penetrate into the pores of the aerogel-containing material, come into full contact with the ethanol solvent to be removed therein, and efficiently displace the ethanol by virtue of its strong dissolution and diffusion characteristics. Then, by changing the state or discharging the supercritical CO2, the ethanol is carried out, thus achieving the drying purpose. And because the mass transfer speed is fast in the supercritical state, the drying process can be completed within just 4 hours.

[0043] The molecular structure of γ-methacryloxypropyltrimethoxysilane contains hydrolyzable methoxy groups and reactive functional groups such as carbon-carbon double bonds that can participate in chemical reactions. When it is formulated into a 0.3 wt% solution and contacts the material to be treated, the silane molecules will first undergo a hydrolysis reaction on the material surface, and the methoxy groups react with water to form silanol groups (Si-OH). These generated silanol groups will form chemical bonds with the existing hydroxyl groups on the material surface (such as the hydroxyl groups on the surfaces of aerogels, ceramic sheets, etc.) through a condensation reaction, thereby firmly attaching the silane molecules to the material surface and forming a chemically bonded "bridge" structure. At the same time, the carbon-carbon double bond at the other end of the silane molecule has sufficient energy at a curing temperature of 120 °C and can undergo further polymerization reactions with other active molecules or groups in the surrounding environment. For example, it can undergo cross-linking reactions with some resin additives or the organic components of the material itself, causing this "bridge" structure to continuously expand and extend, and finally forming a continuous and stable organosilicon network layer at the interface between the material and the aerogel and at the interfaces of different materials.

[0044] Through the silanization treatment process, the effect of enhancing the interfacial bonding force is achieved. Specifically, between different materials such as aerogels and ceramic sheets or between aerogels and other additives, there may only be simple physical contact or weak interactions. After silanization treatment, strong chemical bonds and a stable organosilicon network are formed at the interface, making the bonding between different materials closer, enabling them to withstand forces synergistically, and being less likely to exhibit phenomena such as delamination and peeling when subjected to external forces, thus solving the problem of insufficient interfacial bonding force between different materials in the building energy-saving insulation integrated board containing aerogels.

[0045] Step S7 includes: a heat-reflecting layer: a composite aluminum-based reflective film with a thickness of 50 μm, a reflectivity > 85%, and an overall thermal conductivity ≤ 0.018 W / (m·K).

[0046] Specifically, microencapsulated epoxy resin is to encapsulate epoxy resin in tiny capsules, and these capsules are uniformly dispersed in the building energy-saving insulation integrated board containing aerogel. When cracks appear in the board due to external forces, temperature changes, and other factors, the stress change at the crack will cause the microcapsules to rupture, and the internal epoxy resin will be released. Utilizing its good fluidity and adhesiveness, it fills into the gaps, thereby repairing the crack site and preventing the crack from further expanding, playing a role in repairing and strengthening the structure of the board.

[0047] Aluminum-based materials themselves have good metallic properties and have a high reflection ability for thermal radiation. When external thermal radiation (such as the infrared and other thermal radiation components in sunlight, or thermal radiation generated by other heat sources in the indoor and outdoor environments) shines on the surface of the composite aluminum-based reflective film, based on its internal electronic structure and metallic lattice characteristics, the free electrons in aluminum atoms can interact with the incident thermal radiation electromagnetic waves. After most of the electromagnetic waves of thermal radiation are absorbed by the free electrons on the surface of the aluminum-based reflective film, they are re-radiated with almost the same energy and direction, thus achieving the reflection of thermal radiation. With its high reflectivity exceeding 85%, it means that the vast majority of thermal radiation can be reflected back, greatly reducing the situation where external thermal radiation enters the interior of the board or internal heat is dissipated outward through thermal radiation. At the same time, the thickness of the composite aluminum-based reflective film is 50μm. This appropriate thickness can not only ensure its sufficient integrity and reflection performance, but also will not increase unnecessary weight and cost due to excessive thickness. Moreover, after being compounded onto the board, it works together with the underlying aerogel and other thermal insulation structures to form a multi-layer thermal barrier system. The aerogel mainly reduces heat conduction through its own porous structure, while the aluminum-based reflective film focuses on blocking thermal radiation. The two complement each other and further block the heat transfer path.

[0048] Through the setting of the thermal reflection layer, the effect of the overall thermal conductivity ≤ 0.018 W / (m・K) is achieved. This means that in the building application scenario, whether in the hot summer, a large amount of high-temperature thermal radiation outdoors is difficult to enter the room in large quantities, enabling the room to maintain a relatively cool environment and reducing the usage frequency of refrigeration equipment such as air conditioners; in the cold winter, the indoor heat is not easily dissipated outdoors through thermal radiation, helping to maintain the warmth indoors and reducing heating energy consumption, solving the problem of insufficient thermal radiation blocking ability of traditional thermal insulation boards.

[0049] Step S8 includes: Quality inspection: Thermal conductivity, laser flash method, error ±5%; Compressive strength, universal testing machine (loading rate 10 mm / min), ≥0.5 MPa; Hydrophobicity, water contact angle tester, ≥150°.

[0050] Specifically, under the condition that the vacuum degree reaches 10⁻³ Pa and is maintained for 2 hours, the air, water vapor, and other impurities inside and on the surface of the board will be pumped out under the action of the internal and external pressure difference. At the same time, some of the original microscopic pore structures inside the material can be further stabilized and optimized in the low-pressure environment, making the internal structure more dense and uniform and reducing the adverse factors that may affect the performance.

[0051] The laser flash method is based on the principle of heat diffusion for measurement. When a high-energy short-pulse laser beam irradiates the surface of a building energy-saving insulation integrated board sample containing aerogel, the energy of the laser is quickly absorbed by the sample surface, causing the temperature of an extremely thin layer of the sample surface to rise instantaneously, forming a heat pulse. This heat pulse propagates into the sample in the form of a heat wave, and a temperature sensor is placed on the other side of the sample for real-time monitoring. By recording the time required for the heat wave to propagate to the other side and analyzing the temperature change situation, combined with known parameters such as the thickness of the sample, and using the physical formulas related to heat diffusion, the thermal diffusivity of the sample can be calculated. Then, combined with information such as the density and specific heat capacity of the sample (these parameters can be obtained in advance through other conventional measurement methods), the thermal conductivity can be deduced. Due to the accuracy of the instrument and various influencing factors in the measurement process, the error is specified to be controlled within ±5% to ensure the reliability and accuracy of the measurement results.

[0052] Place the prepared building energy-saving insulation integrated board specimen containing aerogel between the upper and lower platens of a universal testing machine. After starting the testing machine, apply an axial pressure to the specimen at a set loading rate (10 mm / min). The pressure sensor of the testing machine will measure and record the magnitude of the pressure applied to the specimen in real time, while the displacement sensor will monitor the deformation of the specimen under the action of the pressure. As the pressure continues to increase, when the specimen reaches its limit state (showing signs of damage such as cracking or obvious deformation), record the corresponding maximum pressure value at this time. Then, according to the stress area of the specimen, by calculating the pressure divided by the stress area, the compressive strength value can be obtained, and it is specified that the compressive strength should be ≥0.5 MPa to determine whether the specimen meets the quality requirements in terms of mechanical properties.

[0053] Carefully drop a small drop of deionized water onto the surface of the building energy-saving insulation integrated board containing aerogel. The water contact angle tester will accurately capture the contact angle image of the water droplet formed on the board surface through an optical imaging system from the side. Based on the surface tension balance principle of the liquid-solid-gas three-phase interface, by analyzing the contour of the water droplet and calculating the relevant geometric relationships, the contact angle value formed by the water droplet and the board surface can be obtained. When the contact angle ≥150°, it indicates that the board surface has strong hydrophobicity, and water is difficult to spread and infiltrate on its surface, but rolls in the form of water droplets.

[0054] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing an integrated building energy-saving and thermal insulation board containing aerogel, characterized in that: The following steps are involved: S1. Using diatomaceous earth to replace organic silicon source, the thermal conductivity is reduced to 0.012W / (m·K) after mixing with aerogel, and the cost is reduced by 40%; S2, using silica sol as the silicon source, the molar ratio of ethyl orthosilicate to water is 1:4, and ammonia water is used to adjust the pH to 6.7; S3, the wet gel is mixed with ceramic fiber, epoxy resin and ammonium polyacrylate are added as dispersants, and the slurry viscosity is 500-800mPa·s; S4, aerogel slurry and ceramic thin plate, formed into composite plate through co-extrusion die, and the amount of binder was reduced to 8%; S5, Plate heat treatment stage 1: 100℃, 1 hour, humidity ≤30%, stage 2: 150℃, 2 hours, humidity ≤20%, stage 3: 200℃, 3 hours, humidity ≤10%; S6, using 500-1000L supercritical CO2 equipment, ethanol supercritical conditions are Tc=241.15℃, Pc=6.38MPa, and the drying time is shortened to 4 hours; S7, introduce microencapsulated epoxy resin, which automatically fills the gap when the material cracks, extending the service life to more than 25 years; S8, vacuum degree 10⁻³Pa, time 2 hours, packaging film uses PET / PI composite film.

2. The method for preparing the aerogel-containing building energy-saving and thermal insulation integrated board according to claim 1, characterized in that: The step S1 includes: adding nano-mullite with a particle size of 50 nm and a volume share of 15% and aluminum silicate fiber with a length of 12 mm and a volume share of 20% to the composite reinforcement, the tensile strength is increased to 0.15 MPa and the compressive strength is 0.8 MPa.

3. The method for preparing the aerogel-containing building energy-saving and thermal insulation integrated board according to claim 1, characterized in that: The step S2 includes: gelation reaction: stirring at 25°C for 4 hours to form a three-dimensional network structure, with a wet gel density of 1.2 g / cm³ and a porosity of ≥90%.

4. The method for preparing the aerogel-containing building energy-saving and thermal insulation integrated board according to claim 1, characterized in that: The S3 step includes: homogenization treatment: using an ultrasonic cell disruptor at a value of 20 kHz for 30 minutes to eliminate bubbles and ensure the uniformity of the slurry.

5. The method for preparing the aerogel-containing building energy-saving and thermal insulation integrated board according to claim 1, characterized in that: The S4 step includes: mechanical supercharging: using a 25MPa high-pressure hose for direct pressing, with a plate thickness tolerance of ±0.5mm and a surface density of ≤8kg / m².

6. The method for preparing the aerogel-containing building energy-saving and thermal insulation integrated board according to claim 1, characterized in that: The S5 step also includes: thermal efficiency is increased by 40%, and energy consumption is reduced to 60kWh / m³.

7. The method for preparing the aerogel-containing building energy-saving and thermal insulation integrated board according to claim 1, characterized in that: The step S6 includes: post-treatment: silanization treatment, γ-methacryloxypropyltrimethoxysilane, concentration 0.3wt%, 120°C curing for 2 hours to enhance the interface bonding strength.

8. The method for preparing the aerogel-containing building energy-saving and thermal insulation integrated board according to claim 1, characterized in that: The step S7 includes: heat reflection layer: a composite aluminum-based reflection film with a thickness of 50 μm, a reflectivity of >85%, and an overall thermal conductivity of ≤0.018 W / (m·K).

9. The method for preparing the aerogel-containing building energy-saving and thermal insulation integrated board according to claim 1, characterized in that: The S8 step includes: quality inspection: thermal conductivity, laser flash method, error ±5%; compressive strength, universal testing machine (loading rate 10 mm / min), ≥0.5 MPa; hydrophobicity, water contact angle tester, ≥150°.

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