Lightweight thermal insulation composite external wall panel and preparation method thereof

Abstract

The application relates to the field of building board preparation, and particularly discloses a light thermal-insulation composite external wall board and a preparation method thereof, and a preparation method of the light thermal-insulation composite external wall board, which comprises the following steps: mixing raw materials of a thermal-insulation core material, extruding and foaming by injecting a foaming agent, and cooling and shaping to obtain the thermal-insulation core material; the foaming agent is carbon dioxide and / or 1,1,1,3,3-pentafluoropropane, the nucleating agent is talcum powder which is prepared by sequentially carrying out in-situ grafting and amidation reaction of amino silane and maleic anhydride after intercalation treatment; pouring a bottom layer of a surface layer cement-based light mortar in a mold, laying the thermal-insulation core material, pouring an upper layer of the surface layer cement-based light mortar, and preparing the light thermal-insulation composite external wall board through initial setting and maintenance. The foaming process is mild and controllable, and the nucleating agent cooperates to further ensure that the cells are uniform, fine and high in closed cell rate, so that the core layer is light in weight, high in thermal insulation, fireproof and durable.

Description

Technical Field

[0001] This application relates to the field of building panel preparation, and more specifically, it relates to a lightweight thermal insulation composite exterior wall panel and its preparation method. Background Technology

[0002] With the escalating global energy crisis and the advancement of dual-carbon goals, building energy conservation has become one of the core issues for achieving sustainable development. As a key component of the building envelope, the thermal insulation performance of the exterior wall directly determines the building's energy consumption level and indoor thermal comfort. The development of high-performance lightweight thermal insulation composite exterior wall panels has become an important development direction in the field of building materials.

[0003] Currently, building exterior wall insulation materials are mainly divided into three major systems: organic, inorganic, and composite materials. Among them, organic insulation materials are represented by polystyrene foam and polyurethane foam. Although they are lightweight, have low thermal conductivity, and are easy to mold, they have poor fire resistance, their insulation performance is easily deteriorated, and their environmental protection is insufficient. Inorganic insulation materials, such as rock wool, glass wool, and autoclaved aerated concrete boards, have good fire resistance and are environmentally stable, but they have defects such as strong moisture absorption, easily affected insulation effect, low strength, and easy splicing problems. To overcome the shortcomings of single materials, various composite exterior wall panels have emerged in the prior art. For example, patent application CN101475360A discloses a lightweight magnesium cement thermal insulation exterior wall panel and its processing method. The exterior wall panel body contains a lightweight inorganic thermal insulation core board, which is composed of the following mixture: a magnesium chloride aqueous solution with a Baume degree of 25-30°Be, chopped vinylon engineering fibers, lightweight magnesium oxide, fly ash, and animal protein foaming agent. The lightweight inorganic thermal insulation core board of this lightweight magnesium cement exterior wall panel uses animal protein foam. Foaming the insulation core material results in poor foam stability, making it prone to cracking, collapse, and interconnected pores. This makes it difficult to form a uniform and stable closed-cell structure, leading to a high thermal conductivity, inconsistent mechanical properties, and uneven density. Furthermore, the core material lacks any waterproofing treatment or interface stabilization design, exhibiting an overall hydrophilic inorganic structure with high water absorption. Moisture intrusion damages the internal pores and gel structure, causing a decrease in insulation performance and strength. It also cannot resist freeze-thaw cycles and damp heat aging, ultimately rendering the core material's insulation, mechanical, and durability properties unacceptable for use. Summary of the Invention

[0004] In order to develop an exterior wall panel with uniform and stable foaming, good waterproof performance, and strong interfacial bonding, this application provides a lightweight thermal insulation composite exterior wall panel and its preparation method.

[0005] In a first aspect, this application provides a method for preparing a lightweight thermal insulation composite exterior wall panel, employing the following technical solution: A method for preparing a lightweight thermal insulation composite exterior wall panel includes the following steps: (1) Polystyrene resin, decabromodiphenyl ethane, antimony trioxide, zinc borate, nucleating agent, polyethylene wax, calcium stearate and antioxidant are mixed, kneaded, injected with foaming agent and extruded to foam, and cooled and shaped to obtain thermal insulation core material; the foaming agent is carbon dioxide and / or 1,1,1,3,3-pentafluoropropane, and the nucleating agent is talc powder after intercalation treatment, and then prepared by in-situ grafting and amidation reaction of aminosilane and maleic anhydride in sequence; (2) Dry mix cement, quartz sand, fly ash, and vitrified microspheres, add ethylene-vinyl acetate, hydroxypropyl methylcellulose, polypropylene fiber and polycarboxylate superplasticizer, dry mix, add deionized water and stir evenly to obtain surface cement-based lightweight mortar. (3) Pour the bottom layer of cement-based lightweight mortar into the mold, lay the insulation core material, and then pour the top layer of cement-based lightweight mortar. After initial setting and curing, a lightweight insulation composite exterior wall panel is obtained.

[0006] By adopting the above technical solution, this application uses polystyrene resin-based extruded foamed thermal insulation core material. Compared with the animal protein-foamed magnesium cement-based inorganic thermal insulation core material in the background technology, it fundamentally avoids the problems of unstable foam, easy cracking and collapse, interconnected pores, uneven density, and high thermal conductivity. At the same time, it overcomes the defects of inorganic core materials such as strong hydrophilicity, high water absorption, easy decay of thermal insulation and strength, and poor resistance to freeze-thaw and humid heat aging. It has a more stable closed-cell structure, lower thermal conductivity, better waterproof performance, and more balanced mechanical properties. Secondly, the nucleating agent is modified by intercalation, aminosilane grafting, and amidation. This process can be adapted to both organic polystyrene matrix and inorganic surface mortar systems, significantly improving the interfacial compatibility and bonding strength between the organic core layer and the inorganic surface layer, reducing the risk of delamination, hollowing, and detachment, and enhancing the overall structural stability of the composite wall panel. Finally, it is combined with carbon dioxide and / or 1,1,1,3,3-pentafluoropropane environmentally friendly foaming agent, ensuring a mild and controllable foaming process with no release of harmful substances. The synergistic effect with the nucleating agent further guarantees uniform and fine pores and a high closed-cell rate, simultaneously improving the lightweight, thermal insulation, fire resistance, and durability of the core layer, ultimately resulting in a lightweight thermal insulation composite exterior wall panel with excellent comprehensive performance.

[0007] Preferably, in step (1), the method for preparing the nucleating agent includes the following steps: S1. Dry 100 parts by weight of talc powder at 110-120℃ for 60-90 min, then cool it to 75-85℃, add anhydrous ethanol, then add 1-1.5 parts by weight of dimethyldiethoxysilane, and stir under nitrogen protection for 60 min to obtain the modified nucleating agent. S2, add 2-3 parts by weight of aminosilane to the modified nucleating agent, heat to 80-90℃, and react for 90-120 min; then add 0.8-1.2 parts by weight of maleic anhydride, heat to 95-105℃, and continue to react for 60 min; then vacuum dry at 120-130℃ for 2-3 h to obtain the nucleating agent.

[0008] By adopting the above technical solution, the nucleating agent is prepared by drying and activating talc powder, intercalating silane, grafting aminosilane, and modifying maleic anhydride through midination. It can serve as an efficient nucleation site inside the insulation core material to guide the uniform nucleation and growth of cells, improve the stability and closed-cell rate of the cells, and optimize the lightweight, thermal insulation, and mechanical properties of the core layer. At the same time, its surface has both organic functional groups and inorganic active sites, which can significantly improve the interfacial compatibility between the organic polystyrene insulation core material and the inorganic cement-based mortar layer, enhance the interfacial bonding strength and adhesion between the two layers, avoid delamination, hollowing, and detachment during use, and effectively enhance the overall structural stability and long-term durability of the composite exterior wall panel.

[0009] Preferably, in step S1, 100 parts by weight of talc powder is dried at 110-120℃ for 60-90 min, then cooled to 75-85℃, anhydrous ethanol is added, followed by 1-1.5 parts by weight of dimethyldiethoxysilane. The mixture is kept warm and stirred for 60 min under nitrogen protection, and finally 0.5-2 parts by weight of expanded graphite is added. The mixture is kept warm and stirred for 60-90 min to obtain the modified nucleating agent.

[0010] By adopting the above technical solution, expanded graphite, a typical layered flexible structure, can not only form a stable composite structure with talc under the assistance of silane, but also achieve a tight bond between layers through the layered overlapping effect, further expanding the interlayer spacing and constructing a low thermal conductivity composite system, significantly reducing the overall thermal conductivity and effectively improving the thermal insulation effect; at the same time, its layer edges are rich in active sites, which can serve as efficient heterogeneous nucleation centers, refining the foaming pores, increasing the closed-cell rate, and enhancing the dimensional stability and mechanical strength of the insulation core material; in addition, expanded graphite itself has excellent hydrophobicity, which can effectively reduce the water absorption rate of the board and avoid the thermal insulation performance degradation caused by water intrusion, and has good compatibility with cement matrix and modified interface agent, which can synergistically improve the interfacial bonding force, ultimately achieving simultaneous optimization of the composite insulation board in terms of thermal insulation effect, structural strength, water resistance and cell uniformity, achieving a synergistic improvement in thermal insulation, strength and durability.

[0011] Preferably, the expanded graphite is obtained by reacting graphite and an intercalating agent at 40-60°C for 40-60 min, then adding hydrogen peroxide and continuing the reaction for 30-40 min; the intercalated graphite is then expanded by expanding the intercalated graphite in hot air at 800-950°C for 10-30 s. The intercalating agent is a mixture of phosphoric acid, glacial acetic acid and acetic anhydride in a volume ratio of (3.5-4.5):2:1.

[0012] By adopting the above technical solution, compared with the traditional strong acid high-temperature oxidation intercalation process, this application uses a phosphoric acid-glacial acetic acid-acetic anhydride compound intercalation system, which performs mild intercalation at 40-60℃. The reaction is uniform and controllable, and will not cause oxidation damage to the graphite substrate. It can completely preserve the layered structure and hydrophobic properties of graphite. After intercalation, it is rapidly expanded by hot air at 800-950℃ for 10-30s. With the help of high temperature, the intercalating agent is rapidly vaporized and expanded, allowing the graphite layers to separate quickly and fully, resulting in expanded graphite with a high expansion ratio and complete layered structure. The resulting expanded graphite has excellent nucleation activity, hydrophobicity and low thermal conductivity. It can work synergistically with talc and silane modification systems to optimize the foaming cell structure and improve the interfacial bonding and water resistance, so that the composite wall panel can achieve simultaneous improvement in thermal insulation, strength and durability.

[0013] Preferably, in step S2, 2-3 parts by weight of aminosilane and 0.3-0.5 parts by weight of BYK-333 polyether-modified polysiloxane are added to the modified nucleating agent, the temperature is raised to 80-90℃, and the reaction is carried out for 90-120 min; then 0.8-1.2 parts by weight of maleic anhydride are added, the temperature is raised to 95-105℃, and the reaction is carried out for another 60 min; subsequently, the mixture is vacuum dried at 120-130℃ for 2-3 h to obtain the nucleating agent.

[0014] By adopting the above technical solutions, BYK-333 polyether-modified polysiloxane can effectively reduce the interfacial tension and surface energy of the system, improve the wetting and dispersion state of nucleating agent powder in the organic matrix, and reduce powder agglomeration and foaming defects; at the same time, it can improve the fluidity of the system and the uniformity of cell nucleation, help form a fine and stable cell structure, and further improve the molding stability and structural uniformity of the thermal insulation core material.

[0015] Preferably, in step (1), the foaming agent is a mixture of carbon dioxide and 1,1,1,3,3-pentafluoropropane in a mass ratio of (3-5):(5-7).

[0016] By adopting the above technical solutions, the compounded foaming agent leverages the advantages of carbon dioxide—being environmentally friendly, non-toxic, and low-cost—and possessing supercritical foaming properties, thereby reducing the amount of 1,1,1,3,3-pentafluoropropane used, lowering production costs and global warming potential, and aligning with environmental policy requirements. Simultaneously, the high diffusivity of carbon dioxide enhances foaming efficiency, adapting to existing low-temperature preparation processes and avoiding damage to the active sites of expanded graphite and the layered structure of talc by high temperatures. Furthermore, relying on the excellent foaming performance, fine and uniform pores, and high closed-cell rate of 1,1,1,3,3-pentafluoropropane, the high pressure required for carbon dioxide foaming is reduced, inhibiting pore merging and rupture, improving pore structure stability, further reducing the thermal conductivity of the composite insulation board, and enhancing insulation performance. In addition, the uniform and dense pores formed by the compounded foaming agent perfectly match the porous structure of expanded graphite and the layered interpenetrating structure of talc, reducing pore defects and synergistically improving the compressive strength and dimensional stability of the insulation board.

[0017] Preferably, in step (1), the antioxidant is a mixture of antioxidant 1010 and antioxidant 168 in a mass ratio of 1:(1-3).

[0018] By adopting the above technical solution, antioxidant 1010 can effectively capture free radicals generated in the composite insulation board system, preventing the organic components, modifiers, and the modified structures of expanded graphite and talc from undergoing oxidative degradation. Antioxidant 168 can decompose the peroxides generated during the oxidation process. Combined with the activity of antioxidant 1010, it improves the antioxidant efficiency. Compared with a single antioxidant, it can more comprehensively and effectively delay the aging of the system, avoiding problems such as yellowing, embrittlement, and loss of active sites. The compatibility and dispersibility of the compounded antioxidants are better, and they can be perfectly adapted to the entire process of low-temperature intercalation, hot air expansion, silane modification, and compound foaming. They do not react adversely with other components in the system, and can effectively protect the porous structure and active sites of expanded graphite and the layered modified structure of talc, while avoiding cell defects caused by oxidation during the foaming process.

[0019] Preferably, in step (1), the thermal insulation core material comprises the following raw materials in parts by weight: 100 parts of polystyrene resin, 6-8 parts of decabromodiphenyl ethane, 2-3 parts of antimony trioxide, 2-3 parts of zinc borate, 1.2-2 parts of foaming agent, 0.5-1 parts of nucleating agent, 0.5-1 parts of polyethylene wax, 0.3-0.8 parts of calcium stearate, and 0.3-0.5 parts of antioxidant.

[0020] Preferably, in step (2), the surface cement-based lightweight mortar comprises the following raw materials in parts by weight: 100 parts of sulfoaluminate cement, 80-120 parts of quartz sand, 30-50 parts of fly ash, 20-40 parts of vitrified microspheres, 2-3 parts of ethylene-vinyl acetate, 0.2-0.3 parts of hydroxypropyl methylcellulose, 0.15-0.25 parts of polypropylene fiber, 0.6-0.9 parts of polycarboxylate superplasticizer, and 40-52 parts of deionized water.

[0021] Secondly, this application provides a lightweight thermal insulation composite exterior wall panel, which adopts the following technical solution: A lightweight thermal insulation composite exterior wall panel is prepared using the above-mentioned preparation method.

[0022] By adopting the above technical solution, the lightweight thermal insulation composite exterior wall panel adopts a composite structure of inorganic surface layer cement-based lightweight mortar and organic polystyrene resin-based foamed insulation core material, which effectively solves the problems of unstable foam, poor thermal insulation, weak interface bonding and easy delamination of the overall structure of traditional insulation boards.

[0023] In summary, this application has the following beneficial effects: 1. The nucleating agent in the thermal insulation core material of this application is talc powder that has been modified by intercalation, aminosilane grafting and amidation. This can improve the interfacial compatibility and bonding strength between the organic core layer and the inorganic surface layer, reduce the risk of delamination, hollowing and falling off, and enhance the overall structural stability of the composite wall panel.

[0024] 2. This application introduces expanded graphite into the nucleating agent. Due to its layered flexible structure, active sites and hydrophobicity, it can work synergistically with talc and other materials to optimize the thermal insulation effect, improve structural stability and water resistance, and achieve a synergistic improvement in the overall performance of the composite insulation board.

[0025] 3. By introducing BYK-333 polyether-modified polysiloxane into the nucleating agent, this application can effectively reduce the interfacial tension and surface energy of the system, improve the wetting and dispersion state of the nucleating agent powder in the organic matrix, and reduce powder agglomeration and foaming defects; at the same time, it can improve the fluidity of the system and the uniformity of cell nucleation, help form a fine and stable cell structure, and further improve the molding stability and structural uniformity of the thermal insulation core material. Detailed Implementation

[0026] The present application will be further described in detail below with reference to the embodiments. Unless otherwise specified, the raw materials used in the preparation examples, embodiments and comparative examples of the present application are all commercially available.

[0027] Preparation Example 1 This preparation example discloses a method for preparing a nucleating agent, specifically including the following steps: S1. Weigh 100 kg of 2000 mesh talc powder and dry it for 75 min at 115℃ and 350 r / min stirring speed. Then cool it down to 80℃, add 50 kg of anhydrous ethanol, stir at 180 r / min speed for 18 min, then add 1.25 kg of dimethyldiethoxysilane, and stir at 80℃ and 225 r / min speed for 60 min under nitrogen protection to obtain the modified nucleating agent. S2, 2.5 kg of KH-550 aminosilane was added to the modified nucleating agent and reacted at 85 °C and 275 r / min for 105 min; then 1 kg of maleic anhydride was added, the temperature was raised to 100 °C, and the mixture was stirred at 275 r / min for 60 min to obtain the product; the product was vacuum dried at 125 °C and -0.08 MPa for 2.5 h to obtain the nucleating agent.

[0028] Preparation Example 2 This preparation example is basically the same as Preparation Example 1, except that: S1, 100 kg of 2000 mesh talc powder was weighed and dried for 75 min at 115 °C and 350 r / min stirring speed; then cooled to 80 °C, 50 kg of anhydrous ethanol was added, and stirred at 180 r / min speed for 18 min, then 1.25 kg of dimethyldiethoxysilane was added, and stirred at 80 °C and 225 r / min speed for 60 min under nitrogen protection, then 1 kg of expanded graphite was added, and stirred at the temperature for 75 min to obtain the modified nucleating agent; The preparation method of expanded graphite is as follows: 2.25 kg of intercalating agent (a mixture of phosphoric acid, glacial acetic acid, and acetic anhydride in a volume ratio of 4:2:1) is added dropwise to 1 kg of 100-mesh natural graphite at a dropping rate of 6.5 mL / min, while stirring at a speed of 150 r / min. The reaction temperature is controlled to be stable at 50℃. After the addition is complete, stirring is continued for 50 min. Then, 40 g of hydrogen peroxide is added in three portions, with an interval of 10 min between each addition. Stirring is maintained after each addition, and the reaction continues for 35 min, during which the reaction temperature is controlled to be stable. Intercalated graphite slurry was obtained at 50℃; the intercalated graphite slurry was placed in a vacuum filter and vacuum filtered under a vacuum of -0.08MPa. It was stirred with 500mL of deionized water for 10min and repeatedly washed and filtered until the pH of the washing liquid was 7; the washed graphite filter cake was placed in a 70℃ oven and dried for 2.5h to obtain expandable graphite; the expandable graphite was placed in a hot air expansion furnace, and dry hot air at 900℃ was introduced with a wind speed controlled at 1.8m / s. It was expanded for 20s, crushed, and sieved to obtain 2000-mesh expanded graphite.

[0029] Preparation Example 3 This preparation example is basically the same as Preparation Example 1, except that: in S2, 2.5 kg of KH-550 aminosilane and 0.4 kg of BYK-333 polyether-modified polysiloxane were added to the modified nucleating agent and reacted at 85°C and 275 r / min for 105 min; then 1 kg of maleic anhydride was added, the temperature was raised to 100°C, and the mixture was stirred at 275 r / min for 60 min to obtain the product; the product was then vacuum dried at 125°C and -0.08 MPa for 2.5 h to obtain the nucleating agent.

[0030] Preparation Example 4 This preparation example discloses a method for preparing a nucleating agent, specifically including the following steps: S1. Weigh 100 kg of 2000 mesh talc powder and dry it for 90 min at 110℃ and 350 r / min stirring speed. Then cool it down to 75℃, add 50 kg of anhydrous ethanol, stir at 180 r / min for 18 min, then add 1 kg of dimethyldiethoxysilane, stir at 75℃ and 225 r / min for 60 min under nitrogen protection, then add 0.5 kg of expanded graphite, keep warm and stir for 60 min to obtain the modified nucleating agent. The preparation method of expanded graphite is as follows: 2.25 kg of intercalating agent (a mixture of phosphoric acid, glacial acetic acid, and acetic anhydride in a volume ratio of 3.5:2:1) is added dropwise to 1 kg of 100-mesh natural graphite at a dropping rate of 6.5 mL / min, while stirring at a speed of 150 r / min. The reaction temperature is controlled to be stable at 40℃. After the addition is complete, stirring is continued for 60 min. Then, 40 g of hydrogen peroxide is added in three portions, with an interval of 10 min between each addition. Stirring is maintained after each addition, and the reaction continues for 30 min, during which the reaction temperature is controlled to be stable. Intercalated graphite slurry was obtained at 40℃. The intercalated graphite slurry was placed in a vacuum filter and vacuum filtered under a vacuum of -0.08MPa. It was stirred with 500mL of deionized water for 10min and repeatedly washed until the pH of the washing liquid was 7. The washed graphite filter cake was placed in a 70℃ oven and dried for 2.5h to obtain expandable graphite. The expandable graphite was placed in a hot air expansion furnace and dried hot air at 800℃ was introduced with a wind speed controlled at 1.8m / s. It was expanded for 30s, crushed, and sieved to obtain 2000-mesh expanded graphite. S2, 2 kg of KH-550 aminosilane and 0.3 kg of BYK-333 polyether-modified polysiloxane were added to the modified nucleating agent and reacted at 80 °C and 275 r / min for 120 min; then 0.8 kg of maleic anhydride was added, the temperature was raised to 95 °C, and the mixture was stirred at 275 r / min for 60 min to obtain the product; the product was then vacuum dried at 120 °C and -0.08 MPa for 3 h to obtain the nucleating agent.

[0031] Preparation Example 5 This preparation example discloses a method for preparing a nucleating agent, specifically including the following steps: S1. Weigh 100 kg of 2000 mesh talc powder and dry it for 60 min at 120℃ and 350 r / min stirring speed. Then cool it down to 85℃, add 50 kg of anhydrous ethanol, stir at 180 r / min speed for 18 min, then add 1.5 kg of dimethyldiethoxysilane, stir at 85℃ and 225 r / min speed for 60 min under nitrogen protection, then add 2 kg of expanded graphite, keep warm and stir for 90 min to obtain the modified nucleating agent. The preparation method of expanded graphite is as follows: 2.25 kg of intercalating agent (a mixture of phosphoric acid, glacial acetic acid, and acetic anhydride in a volume ratio of 4.5:2:1) is added dropwise to 1 kg of 100-mesh natural graphite at a dropping rate of 6.5 mL / min, while stirring at a speed of 150 r / min. The reaction temperature is controlled to be stable at 60℃. After the addition is complete, stirring is continued for 40 min. Then, 40 g of hydrogen peroxide is added in three portions, with each portion 10 min apart. Stirring is maintained after each addition, and the reaction continues for 40 min, during which the reaction temperature is controlled to be stable. Intercalated graphite slurry was obtained at 60℃. The intercalated graphite slurry was placed in a vacuum filter and vacuum filtered under a vacuum of -0.08MPa. It was stirred with 500mL of deionized water for 10min and repeatedly washed until the pH of the washing liquid was 7. The washed graphite filter cake was placed in a 70℃ oven and dried for 2.5h to obtain expandable graphite. The expandable graphite was placed in a hot air expansion furnace and dried hot air at 950℃ was introduced with a wind speed controlled at 1.8m / s. It was expanded for 10s, crushed, and sieved to obtain 2000-mesh expanded graphite. S2, 3 kg of KH-550 aminosilane and 0.5 kg of BYK-333 polyether-modified polysiloxane were added to the modified nucleating agent and reacted at 90 °C and 275 r / min for 90 min; then 1.2 kg of maleic anhydride was added, the temperature was raised to 105 °C, and the mixture was stirred at 275 r / min for 60 min to obtain the product; the product was vacuum dried at 130 °C and -0.08 MPa for 2 h to obtain the nucleating agent.

[0032] Example 1 This embodiment provides a method for preparing a lightweight thermal insulation composite exterior wall panel, including the following steps: (1) Thermal insulation core material: 100 kg of polystyrene resin, 7 kg of decabromodiphenyl ethane, 2.5 kg of antimony trioxide, 2.5 kg of zinc borate, 0.75 kg of nucleating agent (obtained in Preparation Example 1), 0.75 kg of polyethylene wax, 0.5 kg of calcium stearate and 0.4 kg of antioxidant (antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1) were mixed at 80 °C and 400 r / min for 30 min to obtain a mixture; the mixture was fed into a twin-screw extruder. The extruder is operated using a rod extruder. Temperatures are controlled at different sections: 140℃ for the feeding section, 165℃ for the melting section, and 180℃ for the die head section. After melt extrusion, 1.6 kg of foaming agent (carbon dioxide and 1,1,1,3,3-pentafluoropropane in a 4:6 mass ratio) is injected. The extrusion foaming temperature is controlled at 160℃ and the foaming pressure at 10 MPa, resulting in a 50 mm thick insulation core material. The insulation core material undergoes interface treatment (coating with 5 wt% KH-550 silane coupling agent solution, at a coating amount of 0.2 kg / m²). 2 (Air dry for 40 minutes) for later use; (2) Surface layer cement-based lightweight mortar: Add 100 kg of sulfoaluminate cement (grade 42.5), 100 kg of quartz sand (passing through 200 mesh with a passing rate ≥90%), 40 kg of fly ash (grade 1), and 30 kg of vitrified microspheres (30-50 mesh) to a mixer and stir at 200 r / min for 20 min. Then add 2.5 kg of ethylene-vinyl acetate (solid content 40%) and 0.25 kg of hydroxypropyl methylcellulose (viscosity 25℃, 100,000-200,000 mPa) in sequence. Add 0.2 kg of polypropylene fiber (diameter 20-30 μm, length 6-12 mm) and continue stirring at 200 r / min for 10 min; finally add 46 kg of deionized water, adjust the stirring speed to 300 r / min, and then add 0.75 kg of polycarboxylate superplasticizer and stir for 25 min to obtain the surface cement-based lightweight mortar. (3) Composite molding: Select a mold with dimensions of 2400mm×1200mm×100mm, and coat the inner wall of the mold with a release agent (machine oil and diesel in a mass ratio of 1:1); pour the above-mentioned surface layer cement-based lightweight mortar into the bottom of the mold with a thickness of 25mm, smooth it with a scraper, and let it stand for 5 minutes; lay the interface-treated insulation core material on the bottom layer mortar, adjust its position to make it centered, and press it flat; then pour the upper layer cement-based lightweight mortar with a thickness of 25mm, smooth it with a scraper, and let it stand for initial setting (25℃, 2h); send the mold into the steam curing chamber, control the steam curing temperature at 60℃ and the humidity at 95%, and cure for 24h; after taking it out, demold it and allow it to cure naturally at a temperature of 25℃ and a humidity of 65% for 28 days to obtain a lightweight insulation composite exterior wall panel.

[0033] Example 2 This embodiment is basically the same as that of Example 1, except that the nucleating agent in step (1) is the one obtained in Preparation Example 2.

[0034] Example 3 This embodiment is basically the same as that of Example 1, except that the nucleating agent in step (1) is the one obtained in Preparation Example 3.

[0035] Example 4 This embodiment provides a method for preparing a lightweight thermal insulation composite exterior wall panel, including the following steps: (1) Thermal insulation core material: 100 kg of polystyrene resin, 6 kg of decabromodiphenyl ethane, 2 kg of antimony trioxide, 2 kg of zinc borate, 0.5 kg of nucleating agent (obtained in Preparation Example 4), 0.5 kg of polyethylene wax, 0.3 kg of calcium stearate, and 0.3 kg of antioxidant (antioxidant 1010 and antioxidant 168 in a mass ratio of 1:2) were mixed at 80°C and 400 r / min for 30 min to obtain a mixture; the mixture was fed into a twin-screw extruder. The temperatures of each section of the extruder were controlled as follows: feed section 140℃, melt section 165℃, and die head section 180℃. After melt extrusion, 1.2 kg of foaming agent (carbon dioxide and 1,1,1,3,3-pentafluoropropane in a mass ratio of 3:7) was injected. The extrusion foaming temperature was controlled at 160℃ and the foaming pressure at 10 MPa to obtain a 50 mm thick insulation core material. The insulation core material was then subjected to interface treatment (coating with 5 wt% KH-550 silane coupling agent solution, coating amount 0.2 kg / m²). 2 (Air dry for 40 minutes) for later use; (2) Surface layer cement-based lightweight mortar: Add 100 kg of sulfoaluminate cement (grade 42.5), 80 kg of quartz sand (passing through 200 mesh with a passing rate ≥90%), 30 kg of fly ash (grade 1), and 20 kg of vitrified microspheres (30-50 mesh) to a mixer and stir at 200 r / min for 20 min. Then add 2 kg of ethylene-vinyl acetate (solid content 40%) and 0.2 kg of hydroxypropyl methylcellulose (viscosity 25℃, 100,000-200,000 mPa) in sequence. Add 0.15 kg of polypropylene fiber (diameter 20-30 μm, length 6-12 mm) and continue stirring at 200 r / min for 10 min; finally add 40 kg of deionized water, adjust the stirring speed to 300 r / min, and then add 0.6 kg of polycarboxylate superplasticizer and stir for 25 min to obtain the surface cement-based lightweight mortar. (3) Composite molding: Select a mold with dimensions of 2400mm×1200mm×100mm, and coat the inner wall of the mold with a release agent (machine oil and diesel in a mass ratio of 1:1); pour the above-mentioned surface layer cement-based lightweight mortar into the bottom of the mold with a thickness of 25mm, smooth it with a scraper, and let it stand for 5 minutes; lay the interface-treated insulation core material on the bottom layer mortar, adjust its position to make it centered, and press it flat; then pour the upper layer cement-based lightweight mortar with a thickness of 25mm, smooth it with a scraper, and let it stand for initial setting (25℃, 2h); send the mold into the steam curing chamber, control the steam curing temperature at 60℃ and the humidity at 95%, and cure for 24h; after taking it out, demold it and allow it to cure naturally at a temperature of 25℃ and a humidity of 65% for 28 days to obtain a lightweight insulation composite exterior wall panel.

[0036] Example 5 This embodiment provides a method for preparing a lightweight thermal insulation composite exterior wall panel, including the following steps: (1) Thermal insulation core material: 100 kg of polystyrene resin, 8 kg of decabromodiphenyl ethane, 3 kg of antimony trioxide, 3 kg of zinc borate, 1 kg of nucleating agent (obtained in Preparation Example 5), 1 kg of polyethylene wax, 0.8 kg of calcium stearate, and 0.5 kg of antioxidant (antioxidant 1010 and antioxidant 168 in a mass ratio of 1:3) were mixed at 80°C and 400 r / min for 30 min to obtain a mixture; the mixture was fed into a twin-screw extruder and controlled to... The extruder temperatures are set as follows: feed section 140℃, melt section 165℃, die head section 180℃. After melt extrusion, 2kg of foaming agent (carbon dioxide and 1,1,1,3,3-pentafluoropropane in a 1:1 mass ratio) is injected. The extrusion foaming temperature is controlled at 160℃ and the foaming pressure at 10MPa to obtain a 50mm thick insulation core material. The insulation core material is then subjected to interface treatment (coating with 5wt% KH-550 silane coupling agent solution, coating amount 0.2kg / m²). 2 (Air dry for 40 minutes) for later use; (2) Surface layer cement-based lightweight mortar: Add 100 kg of sulfoaluminate cement (grade 42.5), 120 kg of quartz sand (passing through 200 mesh with a passing rate ≥90%), 50 kg of fly ash (grade 1), and 40 kg of vitrified microspheres (30-50 mesh) to a mixer and stir at 200 r / min for 20 min. Then add 3 kg of ethylene-vinyl acetate (solid content 40%) and 0.3 kg of hydroxypropyl methylcellulose (viscosity 25℃, 100,000-200,000 mPa) in sequence. Add 0.25 kg of polypropylene fiber (diameter 20-30 μm, length 6-12 mm) and continue stirring at 200 r / min for 10 min; finally add 52 kg of deionized water, adjust the stirring speed to 300 r / min, and then add 0.9 kg of polycarboxylate superplasticizer and stir for 25 min to obtain the surface cement-based lightweight mortar. (3) Composite molding: Select a mold with dimensions of 2400mm×1200mm×100mm, and coat the inner wall of the mold with a release agent (machine oil and diesel in a mass ratio of 1:1); pour the above-mentioned surface layer cement-based lightweight mortar into the bottom of the mold with a thickness of 25mm, smooth it with a scraper, and let it stand for 5 minutes; lay the interface-treated insulation core material on the bottom layer mortar, adjust its position to make it centered, and press it flat; then pour the upper layer cement-based lightweight mortar with a thickness of 25mm, smooth it with a scraper, and let it stand for initial setting (25℃, 2h); send the mold into the steam curing chamber, control the steam curing temperature at 60℃ and the humidity at 95%, and cure for 24h; after taking it out, demold it and allow it to cure naturally at a temperature of 25℃ and a humidity of 65% for 28 days to obtain a lightweight insulation composite exterior wall panel.

[0037] Comparative Example 1 The difference between this comparative example and Example 1 is that in step (1) the insulation core material is as follows: 99% pure light anhydrous magnesium oxide is completely dissolved in an appropriate amount of water, and a 25°Bé magnesium chloride aqueous solution is prepared by Baume degree testing; 90 kg of the 25°Bé magnesium chloride aqueous solution is added to 0.1 kg of short-cut vinylon engineering fibers (length 5-15 mm), stirred until uniformly mixed, then 110 kg of light magnesium oxide (purity 80-90%, fineness 180-350 mesh, active ingredient 60-70%) is added and mixed evenly, followed by 22 kg of fly ash and stirred until uniformly mixed to obtain a mixed slurry; 3 kg of animal protein foaming agent is diluted with 12 times the amount of water, and then... Foam was obtained using a high-pressure gas foaming mechanism; animal protein foam, equivalent to 4.2 times the volume of the mixed slurry, was added to the mixed slurry and stirred until uniformly mixed to obtain the core material slurry; after laying a glass fiber mesh in a core board mold, the core material slurry was poured in, and a glass fiber mesh cloth was laid on the front surface of the core material slurry. After natural curing for 6 hours at an indoor temperature of 30℃ and a relative humidity of 50%, the material was demolded. After demolding, it was further cured for 15 days at an indoor temperature of 30℃ and a relative humidity of 50% to obtain a 50mm thick thermal insulation core material; the thermal insulation core material was then subjected to interface treatment (coating with 5wt% KH-550 silane coupling agent solution, coating amount 0.2kg / m²). 2 (Let it air dry for 40 minutes) for later use.

[0038] Comparative Example 2 This comparative example is basically the same as Example 1, except that in step (1), the nucleating agent is 2000 mesh talc powder.

[0039] Performance testing Thermal conductivity (25℃): GB / T10294-2008; In accordance with the above testing standards, the thermal insulation performance of the insulation core materials of Examples 1-5 and Comparative Examples 1-2 was tested, and the test results are recorded in Table 1.

[0040] Bulk density: GB / T11969-2020; Interfacial bond strength: GB / T25181-2019; Drying shrinkage rate (28d): GB / T30100-2013; Compressive strength (28d): GB / T30100-2013; Freeze resistance (25 cycles): According to GB / T30100-2013, freezing at -20℃ for 8 hours and immersion in water at 20℃ for 16 hours constitutes one cycle, for a total of 25 cycles. The compressive strength and interfacial bond strength are tested after the cycles, and the compressive strength retention rate and interfacial bond strength retention rate are calculated. Flame retardancy: GB / T8624-2012; Water absorption rate (24h): GB / T30100-2013.

[0041] In accordance with the above testing standards, the lightweight thermal insulation composite exterior wall panels obtained in Examples 1-5 and Comparative Examples 1-2 were subjected to performance tests. The test results are shown in Tables 2 and 3.

[0042] Table 1. Thermal insulation performance test data of the thermal insulation core materials of Examples 1-5 and Comparative Examples 1-2.

[0043] Table 2 Performance test data of lightweight thermal insulation composite exterior wall panels in Examples 1-5 and Comparative Examples 1-2

[0044] Table 3 Performance test data of lightweight thermal insulation composite exterior wall panels in Examples 1-5 and Comparative Examples 1-2

[0045] Combining Example 1 and Comparative Example 1 with reference to Tables 1-3, it can be seen that Example 1, using a polystyrene extrusion foaming system and a talc nucleating agent modified by silane intercalation, amino grafting, and amidation, can form a uniform and dense closed-cell structure, effectively blocking heat transfer and moisture intrusion. Therefore, its thermal insulation performance, waterproof performance, and dimensional stability are superior to Comparative Example 1. Comparative Example 1 uses magnesium cement core material foamed with animal protein, which has poor foam stability, is prone to interconnection and collapse, and the inorganic matrix itself is highly hydrophilic with weak interfacial bonding, resulting in poor thermal insulation, high water absorption, and low mechanical strength. Meanwhile, the nucleating agent in Example 1 has both organic functional groups and inorganic active sites, which can form a good interfacial bond between the organic core material and the inorganic surface layer, improving interfacial bonding strength and freeze-thaw resistance, and also has a better flame retardant rating.

[0046] Combining Example 1 and Comparative Example 2, and referring to Tables 1-3, it can be seen that Comparative Example 2 directly uses unmodified talc as a nucleating agent, resulting in poor cell uniformity during extrusion foaming and limited compatibility with the organic matrix and inorganic surface layer. This leads to low overall thermal insulation performance, mechanical strength, and interfacial bonding. In contrast, the talc in Example 1 undergoes multi-stage modification through intercalation activation, aminosilane grafting, and maleic anhydride amidation. This not only efficiently induces the formation of a uniform and fine closed-cell structure during foaming, improving thermal insulation performance and dimensional stability, but also the amphiphilic functional groups introduced on its surface significantly improve the interfacial bonding state between the organic core material and the inorganic mortar layer, enhancing interfacial adhesion strength and structural integrity. Furthermore, the synergistic effect of the antioxidant system and flame-retardant components makes it superior to Comparative Example 2 in terms of compressive strength, water resistance, and freeze-thaw durability.

[0047] Combining Examples 1 and 2 and referring to Tables 1-3, it can be seen that Example 2, due to the introduction of expanded graphite components into the nucleating agent, exhibits further improved overall performance compared to Example 1. The expanded graphite and modified talc form a layered interpenetrating composite structure, which not only further optimizes the morphology and closed-cell rate of the cells, effectively reducing heat conduction to improve insulation, but also reduces the water absorption rate of the board due to its excellent hydrophobic properties, minimizing moisture erosion of the internal structure. Furthermore, the active sites at the edges of the expanded graphite synergistically enhance the interfacial bonding between the organic core material and the inorganic surface layer, improving the mechanical properties and freeze-thaw resistance of the system. Therefore, Example 2 outperforms Example 1, which only uses silane-modified talc nucleating agent, in terms of insulation, waterproofing, strength, and long-term stability.

[0048] Combining Examples 1 and 3 and referring to Tables 1-3, it can be seen that Example 3 introduced BYK-333 polyether-modified polysiloxane during the nucleating agent preparation process, which significantly improved the overall performance of the material. This additive can effectively reduce the interfacial tension and surface energy of the system, improve the dispersion state of the nucleating agent powder in the system, reduce agglomeration, and at the same time reduce interfacial tension, promoting a more uniform and stable foaming process, thereby optimizing the internal pore structure and overall density of the core material. In addition, its organosilicon structure further improves the compatibility between the nucleating agent and the organopolystyrene matrix, making the interfacial bond between the core material and the surface mortar stronger. It is superior to Example 1 without the additive in terms of compressive strength, dimensional stability, water resistance, and freeze-thaw durability.

[0049] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A method for preparing a lightweight thermal insulation composite exterior wall panel, characterized in that, Includes the following steps: (1) Polystyrene resin, decabromodiphenyl ethane, antimony trioxide, zinc borate, nucleating agent, polyethylene wax, calcium stearate and antioxidant are mixed, kneaded, injected with foaming agent and extruded to foam, and cooled and shaped to obtain thermal insulation core material; the foaming agent is carbon dioxide and / or 1,1,1,3,3-pentafluoropropane, the nucleating agent is talc powder after intercalation treatment, and then prepared by in-situ grafting and amidation reaction of aminosilane and maleic anhydride; the intercalation treatment is dimethyldiethoxysilane, in ethyl... (1) Under the protection of nitrogen and alcohol system, silane intercalation of talc powder is carried out at 75-85℃; (2) Cement, quartz sand, fly ash and vitrified microspheres are dry mixed, ethylene-vinyl acetate, hydroxypropyl methylcellulose, polypropylene fiber and polycarboxylate superplasticizer are added and dry mixed, and deionized water is added and stirred evenly to obtain surface cement-based lightweight mortar; (3) The bottom layer of surface cement-based lightweight mortar is poured in the mold, the thermal insulation core material is laid, and the top layer of surface cement-based lightweight mortar is poured. After initial setting and curing, lightweight thermal insulation composite exterior wall panel is obtained.

2. The method for preparing the lightweight thermal insulation composite exterior wall panel according to claim 1, characterized in that, In step (1), the preparation method of the nucleating agent includes the following steps: S1, drying 100 parts by weight of talc powder at 110-120℃ for 60-90 min, then cooling to 75-85℃, adding anhydrous ethanol, then adding 1-1.5 parts by weight of dimethyldiethoxysilane, stirring under nitrogen protection for 60 min to obtain the modified nucleating agent; S2, adding 2-3 parts by weight of aminosilane to the modified nucleating agent, heating to 80-90℃, reacting for 90-120 min; then adding 0.8-1.2 parts by weight of maleic anhydride, heating to 95-105℃, continuing the reaction for 60 min; then vacuum drying at 120-130℃ for 2-3 h to obtain the nucleating agent.

3. The method for preparing the lightweight thermal insulation composite exterior wall panel according to claim 2, characterized in that, S1. Dry 100 parts by weight of talc powder at 110-120℃ for 60-90 min, then cool to 75-85℃, add anhydrous ethanol, then add 1-1.5 parts by weight of dimethyldiethoxysilane, keep warm and stir for 60 min under nitrogen protection, and finally add 0.5-2 parts by weight of expanded graphite, keep warm and stir for 60-90 min to obtain the modified nucleating agent.

4. The method for preparing the lightweight thermal insulation composite exterior wall panel according to claim 3, characterized in that, The expanded graphite is obtained by reacting graphite with an intercalating agent at 40-60℃ for 40-60 min, then adding hydrogen peroxide and continuing the reaction for another 30-40 min; the intercalated graphite is then expanded under hot air at 800-950℃ for 10-30 s to obtain expanded graphite; the intercalating agent is a mixture of phosphoric acid, glacial acetic acid and acetic anhydride in a volume ratio of (3.5-4.5):2:

1.

5. The method for preparing the lightweight thermal insulation composite exterior wall panel according to claim 2, characterized in that, S2, add 2-3 parts by weight of aminosilane and 0.3-0.5 parts by weight of BYK-333 polyether-modified polysiloxane to the modified nucleating agent, heat to 80-90℃, and react for 90-120 min; then add 0.8-1.2 parts by weight of maleic anhydride, heat to 95-105℃, and continue to react for 60 min; then vacuum dry at 120-130℃ for 2-3 h to obtain the nucleating agent.

6. The method for preparing the lightweight thermal insulation composite exterior wall panel according to claim 1, characterized in that, In step (1), the foaming agent is a mixture of carbon dioxide and 1,1,1,3,3-pentafluoropropane in a mass ratio of (3-5):(5-7).

7. The method for preparing the lightweight thermal insulation composite exterior wall panel according to claim 1, characterized in that, In step (1), the antioxidant is a mixture of antioxidant 1010 and antioxidant 168 in a mass ratio of 1:(1-3).

8. The method for preparing the lightweight thermal insulation composite exterior wall panel according to claim 1, characterized in that, In step (1), the thermal insulation core material comprises the following raw materials in parts by weight: 100 parts polystyrene resin, 6-8 parts decabromodiphenyl ethane, 2-3 parts antimony trioxide, 2-3 parts zinc borate, 1.2-2 parts foaming agent, 0.5-1 part nucleating agent, 0.5-1 part polyethylene wax, 0.3-0.8 parts calcium stearate, and 0.3-0.5 parts antioxidant.

9. The method for preparing the lightweight thermal insulation composite exterior wall panel according to claim 1, characterized in that, In step (2), the surface cement-based lightweight mortar comprises the following raw materials in parts by weight: 100 parts of sulfoaluminate cement, 80-120 parts of quartz sand, 30-50 parts of fly ash, 20-40 parts of vitrified microspheres, 2-3 parts of ethylene-vinyl acetate, 0.2-0.3 parts of hydroxypropyl methylcellulose, 0.15-0.25 parts of polypropylene fiber, 0.6-0.9 parts of polycarboxylate superplasticizer, and 40-52 parts of deionized water.

10. A lightweight thermal insulation composite exterior wall panel, characterized in that, It is prepared by the method of any one of claims 1-9 for the preparation of lightweight thermal insulation composite exterior wall panels.

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