Environment-friendly fire-resistant light decorative plate and preparation method thereof

Abstract

The invention relates to the technical field of decorative plates, and particularly discloses an environment-friendly fireproof light decorative plate and a preparation method thereof. An environment-friendly fireproof lightweight decorative plate comprises a base material and a coating coated on the surface of the base material, and the base material comprises the following raw materials in parts by mass: 25-35 parts of silica fume, 20-30 parts of rice hull ash, 30-40 parts of calcium hydroxide micro powder, 18-35 parts of lightweight aggregate, 5-10 parts of composite fibers, 0.3-1.0 part of a polycarboxylic acid water reducer, 0.1-0.3 part of hydroxypropyl methyl cellulose, 0.1-0.3 part of zinc stearate, 3-6 parts of silicone acrylic emulsion and water; the dosage of the water is (0.4-0.6) times of the total mass of the silica fume, the rice hull ash and the calcium hydroxide micro powder; the environment-friendly fire-resistant light decorative plate prepared by the invention shows better collaborative optimization in multiple dimensions of light weight, high strength and fire resistance.

Description

Technical Field

[0001] The present application relates to the technical field of decorative panels, and more specifically, to an environmentally friendly, fire-resistant, lightweight decorative panel and a preparation method thereof. Background Art

[0002] With the development of green buildings and prefabricated decoration, the demand for environmentally friendly, safe, and functionally integrated interior decoration materials is increasing. Traditional decorative materials such as gypsum board and plywood generally have the following flaws: First, they pose significant environmental risks. Some materials contain carcinogens such as asbestos or release volatile organic compounds (VOCs) such as formaldehyde, posing long-term health risks to indoor environments. This is particularly true in crowded places like hospitals and schools. Second, they lack fire resistance, with most only meeting the B1 flame retardancy standard. They easily burn and release toxic gases in fires, making them difficult to meet public building fire protection regulations. Third, they suffer from limited performance and inefficient construction. The high density of traditional board materials requires on-site painting, which prolongs construction time, increases pollution, and carries high maintenance costs. These materials are unable to meet the industrial requirements of prefabricated buildings for rapid installation and green construction.

[0003] In recent years, calcium silicate board-based decorative materials have gradually gained popularity. Their environmentally friendly, 100% asbestos- and formaldehyde-free nature, fire resistance, and the construction efficiency advantages of a pre-coating process have made them a top choice for green buildings. However, compared with ultra-lightweight materials like rock wool and aerogel, there is still room for improvement in lightweighting. Currently, most calcium silicate decorative boards in the industry still rely on the inherent material properties of the substrate to achieve lightweighting, limiting their application in scenarios such as reducing the weight of high-rise buildings and optimizing transportation energy consumption.

[0004] The patent application document with publication number CN117263634A discloses a method for preparing a calcium silicate board, comprising the following steps: S1, mixing 80-100 parts of lime slag, 60-80 parts of fly ash, 70-80 parts of water, and 1-5 parts of a water reducer to obtain slurry A; S2, mixing 30-50 parts of waste rubber, 30-50 parts of coal gangue, 60-70 parts of fiber, 40-60 parts of water, and a grinding aid to obtain slurry B; S3, mixing slurry A and slurry B, filtering, extruding, and pre-curing to obtain a pre-cured green body; S4, autoclaving and curing the pre-cured green body, and drying to obtain a calcium silicate board.

[0005] In this technical solution, industrial solid waste (lime slag, fly ash, waste rubber, coal gangue) accounts for a high proportion and has complex characteristics. Among them, cementitious components such as lime slag and fly ash are prone to insufficient cementation reaction due to differences in activity and unreasonable proportions, thereby generating low-strength products; at the same time, the potential radioactive nuclides in coal gangue and fly ash and the organic residues of waste rubber will also bring environmental and safety risks, and impurities can easily cause internal structural defects, resulting in deterioration of properties such as flexural strength. Summary of the Invention

[0006] In order to meet the multi-dimensional requirements of green buildings for decorative materials that are lightweight, high-strength, fire-resistant and environmentally friendly, the present application provides an environmentally friendly, fire-resistant, lightweight decorative board and a preparation method thereof.

[0007] In a first aspect, the present application provides an environmentally friendly fire-resistant lightweight decorative panel, which adopts the following technical solution: An environmentally friendly fire-resistant lightweight decorative board comprises a substrate and a coating applied on the surface of the substrate, wherein the substrate contains the following raw materials in parts by weight: 25-35 parts of silica fume, 20-30 parts of rice husk ash, 30-40 parts of calcium hydroxide powder, 18-35 parts of lightweight aggregate, 5-10 parts of composite fiber, 0.3-1.0 part of polycarboxylate water reducer, 0.1-0.3 part of hydroxypropyl methylcellulose, 0.1-0.3 part of zinc stearate, 3-6 parts of silicone acrylic emulsion and water; The amount of water used is (0.4-0.6) times the total mass of silica fume, rice husk ash and calcium hydroxide powder; The lightweight aggregate is a compound of hollow glass microspheres and ceramsite that have been subjected to two-stage coating treatment; the two-stage coating includes a shell layer and a functional layer, the shell layer is a silane-silicone resin layer; and the functional layer is a magnesium hydroxide-graphene composite flame retardant layer.

[0008] This technical solution uses silica fume, rice husk ash, and calcium hydroxide powder as the core cementitious system. Silica fume and rice husk ash provide highly active siliceous components, which react with calcium hydroxide powder to form a dense cementitious product, laying a high-strength skeleton foundation for the substrate. Furthermore, hollow glass microspheres and expanded clay, which have undergone a two-stage coating process, are introduced as lightweight aggregates. The silane-silicone resin shell layer strengthens the interfacial adhesion between the aggregate and the cementitious system through chemical bonding, while the magnesium hydroxide-graphene functional layer enhances fire resistance through endothermic decomposition and fire-retardant and oxygen-isolating mechanisms. The addition of composite fibers further constructs a rigid-flexible composite reinforcement network, compensating for the strength loss that may be caused by lightweight aggregates. Simultaneously, additives such as polycarboxylate superplasticizer and hydroxypropyl methylcellulose synergistically regulate the slurry's rheological properties and construction performance, ensuring uniform dispersion of the components and forming a stable structure. Ultimately, through the synergistic effect of these components, the substrate maintains a low density while combining high strength, high fire resistance, and environmental safety. After application of the composite coating, a decorative panel with optimized multi-dimensional performance is formed, meeting the stringent material functional requirements of green buildings.

[0009] Preferably, the thickness of the coating is 35-70 μm.

[0010] Preferably, the coating material used in the coating is UV coating.

[0011] Preferably, the composite fiber includes basalt fiber and meta-aramid.

[0012] Preferably, the mass ratio of the basalt fiber to the meta-aramid is (3-6):(2-4).

[0013] Preferably, the diameter of the basalt fiber is 9-13 μm, and the chopped length is 3-6 mm.

[0014] Preferably, the diameter of the meta-aramid is 10-20 μm, and the chopped length is 3-6 mm.

[0015] Preferably, the rice husk ash is activated at a temperature of 650-750° C. for 2-4 hours before use and is set aside.

[0016] In this technical solution, rice husk ash is activated at a temperature of 650~750℃ before use. On the one hand, it can effectively remove organic matter in the rice husk ash and form a microporous structure, increase the specific surface area, accelerate the volcanic ash reaction to generate tobermorite and CSH gel, and improve the strength, fire resistance and density of the substrate.

[0017] Preferably, the method for preparing the lightweight aggregate comprises the following steps: S11: uniformly mixing the silane coupling agent, the aqueous silicone resin emulsion, and the ethanol aqueous solution, adjusting the pH to 5.5-6.5, heating to 60-80° C., reacting for 35-45 minutes, and cooling to room temperature to obtain a silane-silicone resin solution; S12: adding ceramsite and hollow glass microspheres to the silane-silicone resin solution, mixing for 15-25 minutes, separating the solid and liquid, and drying to obtain a pre-coated material; S13: uniformly dispersing magnesium hydroxide and graphene in aqueous acrylate, adding a crosslinking agent, and mixing for 15 to 25 minutes to obtain a composite coating liquid; then uniformly applying the composite coating liquid to the surface of the pre-coated object and curing it to obtain a lightweight aggregate.

[0018] Preferably, the mass ratio of the silane coupling agent, the aqueous silicone resin emulsion and the ethanol aqueous solution is (0.5-1.5):(2.5-3.5):(5.5-6.5).

[0019] Preferably, the mass ratio of the magnesium hydroxide, graphene and aqueous acrylate is (1.5-2.5):(0.5-1.5):(5.5-6.5).

[0020] Preferably, the mass ratio of the ceramsite to the hollow glass microspheres is (1.5-2):1.

[0021] Preferably, the mass ratio of the total mass of the ceramsite and the hollow glass microspheres, the silane-silicone resin solution and the composite coating liquid is 1:(1.5-2.5):(0.25-0.35).

[0022] Preferably, the mass concentration of the aqueous silicone resin emulsion is 25% to 35%.

[0023] Preferably, the mass concentration of the water-based acrylate is 40% to 50%.

[0024] Preferably, the amount of the cross-linking agent is 1.3% to 1.54% by mass of the water-based acrylate.

[0025] In this technical solution, first, the silane coupling agent is hydrolyzed under weakly acidic conditions to generate silanol groups, which form a pre-cross-linked network with the water-based silicone resin emulsion. This solution is evenly dispersed on the surface of the expanded clay and hollow glass microspheres, and after drying, an elastic silane-silicone resin shell layer bonded by covalent bonds is formed; then, the magnesium hydroxide nanoparticles and graphene sheets are evenly dispersed in the acrylic resin to form a composite coating liquid. After being coated on the surface of the pre-coated object, the acrylic resin and the silicone resin shell are interlocked through hydrogen bonds, so that the functional layer is firmly attached. The magnesium hydroxide decomposes at high temperatures to absorb heat and cool down, and the graphene forms a barrier layer to inhibit heat and oxygen transfer; this hierarchical design enables the lightweight aggregate to have low-density skeleton support, strong interface bonding and high-efficiency flame retardant functions. When it works synergistically with the silica fume-rice husk ash-based cementitious system, it significantly improves the mechanical properties and fire resistance of the decorative board, thereby achieving optimized integration of the multi-dimensional performance of the material.

[0026] Preferably, the ceramsite undergoes the following simple pretreatment steps before use: The aqueous epoxy resin emulsion, curing agent, propylene glycol methyl ether and water are uniformly mixed to obtain an emulsion; the ceramsite is then immersed in the emulsion for 20 to 30 minutes, solid-liquid separation is performed, and solidification is performed to obtain the product.

[0027] Preferably, the mass ratio of the water-based epoxy resin emulsion, curing agent, propylene glycol methyl ether and water is (15-20): (8-10): (5-7): (60-70).

[0028] Preferably, the mass ratio of the ceramsite to the emulsion is 1:(1.5~2.5).

[0029] Preferably, the curing conditions are: 75-85° C., drying for 110-130 min.

[0030] Preferably, the curing agent is an amine.

[0031] In this technical solution, the water-based epoxy resin emulsion can penetrate into the pores on the surface of the ceramsite and deep into the gaps through molecular-level infiltration, and form a continuous resin film of uniform thickness after curing. This film layer reduces the water absorption of the ceramsite through the dual effects of physical filling (flexible chain segments blocking pores) and chemical anchoring (epoxy groups combining with hydroxyl groups on the surface of the ceramsite), and can also improve the interfacial bonding strength between the ceramsite particles and the subsequent coating layer.

[0032] Preferably, the ceramsite undergoes the following deep pretreatment steps before use: The method comprises the following steps: uniformly mixing water glass, nano-silica dispersion, methyltrimethoxysilane hydrolyzate and borax, adjusting the pH value to 7.5-8, and obtaining a homogeneous sol; then immersing the ceramsite in the homogeneous sol, evacuating the mixture to -0.08--0.1 MPa, immersing the mixture for 20-30 minutes, separating the solid and the liquid, drying the mixture at 70-90° C. for 1.5-2.5 hours, continuously heating the mixture to 110-130° C., and drying the mixture to a constant weight.

[0033] Preferably, the mass ratio of the sodium silicate in the water glass, the nano-silica in the nano-silica dispersion, the methyltrimethoxysilane in the methyltrimethoxysilane hydrolyzate, and the borax is (28-40): (2-6): (2.5-3.5): (1-2).

[0034] In this technical solution, a vacuum environment is used to encourage the homogeneous sol to penetrate into the pores on the surface of the ceramsite and deep into the gaps, forming a continuous and dense protective layer on the surface of the ceramsite and in some micropores; this protective layer significantly improves the closed porosity of the ceramsite micropores and reduces the water absorption rate through the dual mechanisms of chemical sealing and physical filling, and subsequently enables it to be tightly combined with the silane-silicone resin shell layer, forming a synergistic reinforcement effect.

[0035] Preferably, the mass ratio of the homogeneous sol to the ceramsite is (1.5-2.0):1.

[0036] Preferably, the mass concentration of the water glass is 20% to 25%.

[0037] Preferably, the method for preparing the nano-silicon dioxide dispersion comprises the following steps: The nano-silica is evenly mixed with a silane coupling agent aqueous solution with a mass concentration of 1% to 3% and a pH of 4 to 5 to obtain the product.

[0038] Preferably, the silane coupling agent is silane coupling agent KH560.

[0039] Preferably, the mass concentration of the nano-silicon dioxide dispersion is 20% to 30%.

[0040] Preferably, the particle size of the nano-silica is 20-50 nm.

[0041] Preferably, the method for preparing the methyltrimethoxysilane hydrolyzate comprises the following steps: Methyltrimethoxysilane, ethanol and water are uniformly mixed, the pH is adjusted to 4-5, the temperature is raised to 40-60°C, and the hydrolysis reaction is carried out for 50-70 minutes to obtain the product; the mass ratio of methyltrimethoxysilane, ethanol and water is (0.8-1.2): (2.5-3.5): (1.5-2.5).

[0042] Preferably, the environmentally friendly fire-resistant lightweight decorative board further comprises 1 to 1.8 parts by mass of aluminum borate whiskers.

[0043] In this technical solution, aluminum borate whiskers are uniformly dispersed in the gelling system, which significantly improves the toughness, impact resistance and high-temperature stability of the substrate by bridging microcracks in the substrate and delaying crack propagation.

[0044] In a second aspect, the present application provides a method for preparing the above-mentioned environmentally friendly fire-resistant lightweight decorative board, comprising the following steps: S1: Slurry preparation: Mix silica fume, rice husk ash and calcium hydroxide powder evenly, add silicone acrylic emulsion, water and polycarboxylate water reducer and mix evenly, add composite fiber and lightweight aggregate and mix evenly, then add hydroxypropyl methylcellulose and zinc stearate and mix evenly to obtain slurry; S2: Forming and curing: After vibration forming, pre-curing, autoclaving and drying are carried out in sequence to obtain the base material; S3: Decorative protection: After pre-treatment of the substrate surface, apply the composite coating with a roller.

[0045] In this technical solution, during the slurry preparation stage, the silica fume, rice husk ash and calcium hydroxide powder cementitious system generates a dense tobermorite skeleton, the composite fiber constructs a rigid-flexible network, and the lightweight aggregate graded coating effectively seals the pores to avoid high-temperature cracking while effectively enhancing the interface bonding and flame retardancy, ultimately achieving the goal of reducing the substrate density while improving the compressive strength and fire resistance.

[0046] Preferably, the pre-curing conditions are: temperature 20-30°C, relative humidity ≥90%, and curing time 24-28h.

[0047] Preferably, the conditions for the autoclave curing are: pressure 1.2-1.5 MPa, temperature 180-200° C., and curing time 6-8 h.

[0048] Preferably, when adding lightweight aggregate, the method further includes adding aluminum borate whiskers.

[0049] In summary, this application has the following beneficial effects: 1. This application uses silica fume, rice husk ash, and calcium hydroxide powder to gel and react to construct a high-strength skeleton, combined with two-stage coated hollow glass microspheres and ceramsite lightweight aggregate. While reducing the density of the substrate, the silane-silicone resin shell layer is used to enhance the interface bonding, the magnesium hydroxide-graphene functional layer is used to improve the fire resistance, and the composite fiber is used to construct a rigid and flexible reinforced network, so that the substrate has the characteristics of light weight, high strength, and fire resistance, meeting the needs of green buildings for the multifunctional integration of materials.

[0050] 2. In this application, aluminum borate whiskers are preferably added, which are evenly dispersed inside the substrate, and significantly improve the toughness, impact resistance and high-temperature stability of the substrate by bridging the microcracks of the substrate and delaying the crack propagation. DETAILED DESCRIPTION

[0051] The present application is further described in detail below with reference to the embodiments.

[0052] Unless otherwise specified, the raw materials used in the examples and comparative examples of the present application are all commercially available.

[0053] The mass concentration of UV coating is not less than 90%; the mass concentration of polycarboxylate water reducer is 30%; the water-based epoxy resin emulsion is a water-based phenolic epoxy resin emulsion; the particle size distribution of the expanded clay is 1-3 mm, the surface open porosity is not higher than 20%, and it is dried to constant weight at 105°C before use; the particle size of the hollow glass microspheres is 80-120 μm; the dissolution rate of active silica in rice husk ash is approximately 68%-72%, and after pretreatment at 650-750°C, the dissolution rate of active silica in rice husk ash is 84%-93%; the diameter of the aluminum borate whiskers is 1-2 μm, the length is 10-20 μm, the aspect ratio is 10-20, and the purity is not less than 98%.

[0054] Preparation Examples 1-6 Pretreated Ceramsite Preparation Example 1 The method for pre-treating ceramsite of this preparation example comprises the following steps: 45 g of water-based epoxy resin emulsion, 24 g of ethylenediamine, 15 g of propylene glycol methyl ether and 180 g of water were added to the reactor in sequence, stirred and mixed at a stirring speed of 300 rpm for 10 min, 176 g of ceramsite was added, soaked at 25°C for 20 min, filtered, spread on a tray, and transferred to a blast drying oven and dried at 75°C for 130 min.

[0055] Preparation Example 2 The method for pre-treating ceramsite of this preparation example comprises the following steps: Add 60 g of water-based epoxy resin emulsion, 30 g of ethylenediamine, 21 g of propylene glycol methyl ether and 210 g of water into the reactor in sequence, stir and mix at a stirring speed of 300 rpm for 20 min, add 128 g of ceramsite, soak at 25 ° C for 30 min, filter, spread on a tray, transfer to a blast drying oven, and dry at 85 ° C for 110 min to obtain the product.

[0056] Preparation Example 3 The method for pre-treating ceramsite of this preparation example comprises the following steps: 52.5 g of waterborne epoxy resin emulsion, 27 g of ethylenediamine, 18 g of propylene glycol methyl ether and 195 g of water were added to the reactor in sequence, stirred and mixed at a stirring speed of 300 rpm for 15 min, 146 g of ceramsite was added, soaked at 25 ° C for 25 min, filtered, spread on a tray, and transferred to a blast drying oven and dried at 80 ° C for 120 min.

[0057] Preparation Example 4 The method for pre-treating ceramsite of this preparation example comprises the following steps: 140 g of water glass was added to a reactor, and 10 g of nano-silica dispersion was slowly added at a stirring speed of 200 rpm. The mixture was stirred for 10 min, and then methyltrimethoxysilane hydrolyzate was added. The mixture was stirred for 5 min, and then 1 g of borax powder was added and stirred until completely dissolved. The pH was adjusted to 8.0 with 5% acetic acid to obtain a homogeneous sol. Add 106 g of ceramsite into the impregnation tank, then add the above-mentioned homogeneous sol, seal the tank, evacuate to -0.08 MPa, maintain for 30 minutes, slowly break the vacuum, continue stirring for 10 minutes, take out, filter, spread on a tray, dry with forced air at 70°C for 2.5 hours, continue to heat to 110°C, and dry to constant weight.

[0058] The preparation method of water glass comprises the following steps: 30 g of sodium silicate with a modulus of 3.3 was weighed, 120 g of deionized water was added, and the mixture was stirred at a stirring speed of 200 rpm for 15 minutes to obtain water glass with a mass concentration of 20%.

[0059] The preparation method of nano-silicon dioxide dispersion comprises the following steps: Take 10g of a 1% mass concentration of silane coupling agent KH560 aqueous solution and add it to a beaker. Use 5% mass fraction of acetic acid to adjust the pH to 5 to obtain a pre-dispersion liquid. Take 10g of the pre-dispersion liquid, add 2.5g of nano-silica, transfer to an ultrasonic device, and ultrasonically disperse for 15 minutes at a power of 200W and a frequency of 30KHz to obtain a nano-silica dispersion with a mass fraction of 20%.

[0060] The preparation method of methyltrimethoxysilane hydrolyzate comprises the following steps: Add 2.4 g of methyltrimethoxysilane, 7.5 g of ethanol and 4.5 g of deionized water into a beaker, adjust the pH to 5 with 5% acetic acid, place in a 40°C water bath, stir at 300 rpm, and hydrolyze for 70 min. Cool to obtain methyltrimethoxysilane hydrolyzate.

[0061] Preparation Example 5 The method for pre-treating ceramsite of this preparation example comprises the following steps: 160 g of water glass was added to a reactor, and 20 g of nano-silica dispersion was slowly added at a stirring speed of 200 rpm, and the mixture was stirred for 10 min. Then, methyltrimethoxysilane hydrolyzate was added, and the mixture was stirred for another 10 min. Then, 2 g of borax powder was added and stirred until completely dissolved. The pH was adjusted to 7.5 with 5% by mass acetic acid to obtain a homogeneous sol. Add 97g of ceramsite into the impregnation tank, then add the above-mentioned homogeneous sol, seal the tank, evacuate to -0.1MPa, maintain for 20min, slowly break the vacuum, continue stirring for 10min, take out, filter, spread on a tray, dry with forced air at 90℃ for 1.5h, continue to heat to 130℃, and dry to constant weight.

[0062] The preparation method of water glass comprises the following steps: 42.5 g of sodium silicate with a modulus of 3.3 was weighed, 127.5 g of deionized water was added, and the mixture was stirred at a stirring speed of 200 rpm for 25 minutes to obtain water glass with a mass concentration of 25%.

[0063] The preparation method of nano-silicon dioxide dispersion comprises the following steps: Take 17g of a 3% mass concentration of silane coupling agent KH560 aqueous solution and add it to a beaker. Use 5% mass fraction of acetic acid to adjust the pH to 5 to obtain a pre-dispersion liquid. Take 17g of the pre-dispersion liquid, add 7.3g of nano-silica, transfer to an ultrasonic device, and ultrasonically disperse for 20 minutes at a power of 200W and a frequency of 30KHz to obtain a nano-silica dispersion with a mass fraction of 30%.

[0064] The preparation method of methyltrimethoxysilane hydrolyzate comprises the following steps: Add 3.6 g of methyltrimethoxysilane, 10.5 g of ethanol and 7.5 g of deionized water into a beaker, adjust the pH to 4 with 5% acetic acid, place in a water bath at 60°C, stir at 300 rpm and hydrolyze for 50 min, then cool to obtain methyltrimethoxysilane hydrolyzate.

[0065] Preparation Example 6 The method for pre-treating ceramsite of this preparation example comprises the following steps: 150 g of water glass was added to a reactor, and 20 g of nano-silica dispersion was slowly added at a stirring speed of 200 rpm, and the mixture was stirred for 10 min. Then, methyltrimethoxysilane hydrolyzate was added, and the mixture was stirred for 10 min. Then, 1.5 g of borax powder was added and stirred until completely dissolved. The pH was adjusted to 8.0 with 5% by mass acetic acid to obtain a homogeneous sol. Add 98g of ceramsite into the impregnation tank, then add the above-mentioned homogeneous sol, seal the tank, evacuate to -0.09MPa, maintain for 25min, slowly break the vacuum, continue stirring for 10min, take out, filter, spread on a tray, dry with air at 90℃ for 2h, continue to heat to 120℃, and dry to constant weight.

[0066] The preparation method of water glass comprises the following steps: 35.2 g of sodium silicate with a modulus of 3.3 was weighed, 127.5 g of deionized water was added, and the mixture was stirred at a stirring speed of 200 rpm for 20 minutes to obtain water glass with a mass concentration of 22%.

[0067] The preparation method of nano-silicon dioxide dispersion comprises the following steps: Take 15g of a 2% mass concentration of silane coupling agent KH560 aqueous solution and add it to a beaker. Use 5% mass fraction of acetic acid to adjust the pH to 5 to obtain a pre-dispersion liquid. Take 15g of the pre-dispersion liquid, add 5g of nano-silica, transfer to an ultrasonic device, and ultrasonically disperse for 15 minutes at a power of 200W and a frequency of 30KHz to obtain a nano-silica dispersion with a mass fraction of 25%.

[0068] The preparation method of methyltrimethoxysilane hydrolyzate comprises the following steps: Add 3 g of methyltrimethoxysilane, 9 g of ethanol, and 6 g of deionized water into a beaker, adjust the pH to 4 with 5% acetic acid, place the beaker in a 50°C water bath, stir at 300 rpm, and hydrolyze for 60 min. Cool the beaker to obtain a methyltrimethoxysilane hydrolyzate.

[0069] Preparation Examples 7~12 Lightweight Aggregates Preparation Example 7 The preparation method of the lightweight aggregate of this preparation example comprises the following steps: S11: 18 g of silane coupling agent KH560, 90 g of aqueous silicone resin emulsion, and 198 g of ethanol-water solution (volume ratio of ethanol to water is 1:1) were added to a reactor, transferred to a 40°C water bath, and stirred at 200 rpm for 15 min. The pH was adjusted to 6.5 with 5% acetic acid, maintained at 60°C, and stirred for 45 min. The mixture was cooled to room temperature to obtain a silane-silicone resin solution. S12: 300 g of the above-mentioned silane-silicone resin solution was added to the reactor and stirred at a speed of 200 rpm. 120 g of ceramsite and 80 g of hollow glass microspheres were slowly added and stirred for 15 min. The excess solution was separated by vacuum filtration (-0.08 MPa). The filter cake was dried at 70°C for 2 h to obtain a pre-coated material. S13: The graphene dispersion was added to 38.5 g of aqueous acrylate, and the mixture was transferred to an ultrasonic device and ultrasonically treated at a power of 200 W and a frequency of 30 kHz for 10 min. Then, magnesium hydroxide and sodium hexametaphosphate were added in 5 portions (the same amount was added each time, the total amount of magnesium hydroxide added was 10.5 g, and the total amount of sodium hexametaphosphate added was 0.5 g, with an interval of 5 min between each addition). During this period, stirring was continued at a stirring speed of 600 rpm, and 0.5 g of hexamethoxymethylmelamine was added. Stirring and mixing were continued for 15 min to obtain a composite coating liquid. Immediately take 50g of the composite coating liquid and spray it on the surface of the pre-coated object, and then cure it in a hot air circulation at 120℃ for 120min to obtain a lightweight aggregate.

[0070] Wherein, before magnesium hydroxide is added, it undergoes the following pretreatment steps: Add 0.21 g of stearic acid into a beaker, heat to 75° C., slowly add 10.5 g of magnesium hydroxide, stir and mix at a stirring speed of 600 rpm for 15 minutes, and cool to room temperature to obtain the product.

[0071] The graphene dispersion was prepared by adding 3.5 g of graphene and 10 g of ethanol into a beaker, placing the beaker into an ultrasonic device, and ultrasonically treating the beaker at a power of 200 W and a frequency of 30 kHz for 8 minutes.

[0072] Among them, the mass concentration of water-based silicone resin emulsion is 25%; the mass concentration of water-based acrylate is 40%, and the water-based acrylate is water-based self-crosslinking acrylate (heat-activated type, crosslinking temperature ≥100°C).

[0073] The ceramsite was obtained from Preparation Example 1.

[0074] Preparation Example 8 The preparation method of the lightweight aggregate of this preparation example comprises the following steps: S11: 67.5 g of silane coupling agent KH560, 157.5 g of water-based silicone resin emulsion, and 292.5 g of ethanol-water solution (volume ratio of ethanol to water is 1:1) were added to a reactor, transferred to a 40°C water bath, and stirred at a stirring speed of 200 rpm for 25 min. The pH was adjusted to 5.5 with 5% acetic acid, the temperature was raised to 80°C, stirring was continued for 35 min, and the mixture was cooled to room temperature to obtain a silane-silicone resin solution. S12: 500 g of the above-mentioned silane-silicone resin solution was added to the reactor and stirred at a speed of 200 rpm. 133 g of ceramsite and 67 g of hollow glass microspheres were slowly added and stirred for 25 min. The excess solution was separated by vacuum filtration (-0.08 MPa). The filter cake was dried at 70°C for 3 h to obtain a pre-coated material. S13: The graphene dispersion was added to 45.5 g of aqueous acrylate, and the mixture was transferred to an ultrasonic device and ultrasonically treated at a power of 200 W and a frequency of 30 kHz for 20 min. Then, magnesium hydroxide and sodium hexametaphosphate were added in 5 portions (the same amount was added each time, the total amount of magnesium hydroxide added was 17.5 g, and the total amount of sodium hexametaphosphate added was 0.7 g, with an interval of 5 min between each addition). During this period, stirring was continued at a stirring speed of 600 rpm, and 0.7 g of hexamethoxymethylmelamine was added. Stirring and mixing were continued for 25 min to obtain a composite coating liquid. Immediately take 70g of the composite coating liquid and spray it on the surface of the pre-coated object, and then cure it in a hot air circulation at 120°C for 160 minutes to obtain a lightweight aggregate.

[0075] Wherein, before magnesium hydroxide is added, it undergoes the following pretreatment steps: Add 0.7 g of stearic acid into a beaker, heat to 85° C., slowly add 17.5 g of magnesium hydroxide, stir and mix at a stirring speed of 600 rpm for 25 minutes, and cool to room temperature to obtain the product.

[0076] The graphene dispersion was prepared by adding 10.5 g of graphene and 20 g of ethanol into a beaker, placing the beaker into an ultrasonic device, and ultrasonically treating the beaker at a power of 200 W and a frequency of 30 kHz for 12 minutes.

[0077] Among them, the mass concentration of water-based silicone resin emulsion is 35%; the mass concentration of water-based acrylate is 50%, and the water-based acrylate is water-based self-crosslinking acrylate (heat-activated type, crosslinking temperature ≥100°C).

[0078] The ceramsite was obtained from Preparation Example 2.

[0079] Preparation Example 9 The preparation method of the lightweight aggregate of this preparation example comprises the following steps: S11: 41 g of silane coupling agent KH560, 123 g of aqueous silicone resin emulsion, and 246 g of ethanol-water solution (volume ratio of ethanol to water is 1:1) were added to a reactor, transferred to a 40°C water bath, and stirred at a stirring speed of 200 rpm for 20 min. The pH was adjusted to 6.0 with 5% acetic acid, the temperature was raised to 70°C, stirring was continued for 40 min, and the mixture was cooled to room temperature to obtain a silane-silicone resin solution. S12: 400 g of the above-mentioned silane-silicone resin solution was added to the reactor and stirred at a speed of 200 rpm. 130 g of ceramsite and 70 g of hollow glass microspheres were slowly added and stirred for 20 min. The excess solution was separated by vacuum filtration (-0.08 MPa). The filter cake was dried at 70°C with forced air for 2.5 h to obtain a pre-coated material. S13: The graphene dispersion was added to 42 g of aqueous acrylate, and the mixture was transferred to an ultrasonic device and ultrasonically treated at a power of 200 W and a frequency of 30 kHz for 15 min. Then, magnesium hydroxide and sodium hexametaphosphate were added in 5 portions (the same amount was added each time, the total amount of magnesium hydroxide added was 14 g, and the total amount of sodium hexametaphosphate added was 0.6 g, with an interval of 5 min between each addition). During this period, stirring was continued at a stirring speed of 600 rpm, and 0.6 g of hexamethoxymethylmelamine was added. Stirring and mixing were continued for 20 min to obtain a composite coating liquid. Immediately take 60g of the composite coating liquid and spray it on the surface of the pre-coated object, and then cure it in a hot air circulation at 120°C for 140 minutes to obtain a lightweight aggregate.

[0080] Wherein, before magnesium hydroxide is added, it undergoes the following pretreatment steps: Add 0.42 g of stearic acid into a beaker, heat to 80° C., slowly add 14 g of magnesium hydroxide, stir and mix at a stirring speed of 600 rpm for 20 minutes, and cool to room temperature to obtain the product.

[0081] The graphene dispersion was prepared by adding 7 g of graphene and 15 g of ethanol into a beaker, placing the beaker into an ultrasonic device, and ultrasonically treating the beaker at a power of 200 W and a frequency of 30 kHz for 10 min.

[0082] Among them, the mass concentration of water-based silicone resin emulsion is 30%; the mass concentration of water-based acrylate is 45%, and the water-based acrylate is water-based self-crosslinking acrylate (heat-activated type, crosslinking temperature ≥100°C).

[0083] The ceramsite was obtained from Preparation Example 3.

[0084] Preparation Example 10 The difference between this preparation example and preparation example 9 is: The ceramsite comes from Preparation Example 4.

[0085] Other details are the same as those in Preparation Example 9.

[0086] Preparation Example 11 The difference between this preparation example and preparation example 10 is: The ceramsite was obtained from Preparation Example 5.

[0087] Other details are the same as those in Preparation Example 10.

[0088] Preparation Example 12 The difference between this preparation example and preparation example 11 is: The ceramsite was obtained from Preparation Example 5.

[0089] Other details are the same as those in Preparation Example 11.

[0090] Example 1 The environmentally friendly fire-resistant lightweight decorative board of this embodiment includes a substrate and a coating applied on the surface of the substrate. The substrate contains the following raw materials: 250g silica fume, 200g rice husk ash, 300g calcium hydroxide powder, 180g lightweight aggregate, 50g composite fiber, 3g polycarboxylate water reducer, 1g hydroxypropyl methylcellulose, 1g zinc stearate, 30g silicone acrylic emulsion and 300g water; The coating material used in the coating is UV coating material.

[0091] The composite fibers are 30 g of basalt fiber and 20 g of meta-aramid; the diameter of the basalt fiber is 9 μm, the short cut length is 3 mm, the diameter of the meta-aramid fiber is 10 μm, and the short cut length is 3 mm.

[0092] The lightweight aggregate was obtained from Preparation Example 7.

[0093] Before use, rice husk ash undergoes the following pretreatment steps: Place rice husk ash in a sintering furnace, heat it to 650°C at 5°C / min, activate it for 4 hours, and cool it to room temperature in the furnace to obtain the product.

[0094] The method for preparing the environmentally friendly fire-resistant lightweight decorative board of this embodiment includes the following steps: S1: Slurry preparation: Silica fume, rice husk ash and calcium hydroxide powder were placed in a container and dry-mixed at a stirring speed of 200 rpm for 5 minutes to ensure that there was no agglomeration. Then, silicone acrylic emulsion, water and polycarboxylate water reducer were added. The stirring speed was adjusted to 800 rpm and the mixture was stirred for 8 minutes. Then, composite fiber was added and manually dispersed for 30 seconds until there was no fiber agglomeration. The stirring speed was adjusted to 200 rpm and the mixture was stirred for 2 minutes. Then, lightweight aggregate was added and the mixture was stirred for 5 minutes. Then, hydroxypropyl methylcellulose solution was slowly added dropwise. Then, zinc stearate was added and the stirring speed was adjusted to 300 rpm and the mixture was stirred for 5 minutes to obtain a slurry. S2: Pour the slurry into a 300mm×300mm×10mm steel mold (with a release agent applied to the inner wall), place it on a vibration table (frequency 50Hz, amplitude 0.5mm), and vibrate until the surface is flat and no large bubbles overflow. The vibration time is about 3min. Seal the mold with plastic wrap and move it into a constant temperature and humidity curing box (temperature 20±2℃, humidity ≥90%). After standing for 24h, demould it and transfer it to an autoclave. Heat it to 180℃ at 3℃ / min and simultaneously increase the pressure to 1.2MPa. Curing it at constant temperature and pressure for 8h. After naturally decreasing the pressure and temperature, take it out and transfer it to a 105℃ forced air drying oven to dry it to constant weight to obtain a substrate. S3: Use 200-grit sandpaper to lightly grind the surface of the substrate, and then use compressed air (pressure 0.4MPa) to blow it clean. The surface roughness Ra is ≤ 5μm. Pour the UV coating into the roller coating machine trough, adjust the roller gap to 40μm, and evenly roll it on the substrate surface at a speed of 1.0m / min. Immediately send the coated substrate into the UV curing box (wavelength 365nm, light intensity 80mW / cm 2 ), and cured for 60s to obtain an environmentally friendly fire-resistant lightweight decorative board.

[0095] The hydroxypropyl methylcellulose solution is prepared by uniformly mixing 1 g of hydroxypropyl methylcellulose and 20 g of deionized water.

[0096] Example 2 The environmentally friendly fire-resistant lightweight decorative board of this embodiment includes a substrate and a coating applied on the surface of the substrate. The substrate contains the following raw materials: 350g silica fume, 300g rice husk ash, 400g calcium hydroxide powder, 350g lightweight aggregate, 100g composite fiber, 10g polycarboxylate water reducer, 3g hydroxypropyl methylcellulose, 3g zinc stearate, 60g silicone acrylic emulsion and 630g water; The coating material used in the coating is UV coating material.

[0097] The composite fibers are 60 g of basalt fiber and 40 g of meta-aramid; the diameter of the basalt fiber is 13 μm, the short cut length is 6 mm, the diameter of the meta-aramid fiber is 20 μm, and the short cut length is 6 mm.

[0098] The lightweight aggregate was obtained from Preparation Example 8.

[0099] Before use, rice husk ash undergoes the following pretreatment steps: Place rice husk ash in a sintering furnace, heat it to 750°C at 5°C / min, activate it for 2 hours, and cool it to room temperature with the furnace to obtain the product.

[0100] The method for preparing the environmentally friendly fire-resistant lightweight decorative board of this embodiment includes the following steps: S1: Slurry preparation: Silica fume, rice husk ash and calcium hydroxide powder were placed in a container and dry-mixed at a stirring speed of 200 rpm for 10 minutes to ensure that there was no agglomeration. Then, silicone acrylic emulsion, water and polycarboxylate water reducer were added. The stirring speed was adjusted to 800 rpm and the mixture was stirred for 12 minutes. Then, composite fiber was added and manually dispersed for 60 seconds until there was no fiber agglomeration. The stirring speed was adjusted to 200 rpm and the mixture was stirred for 4 minutes. Then, lightweight aggregate was added and the mixture was stirred for 10 minutes. Then, hydroxypropyl methylcellulose solution was slowly added dropwise. Then, zinc stearate was added and the stirring speed was adjusted to 300 rpm and the mixture was stirred for 10 minutes to obtain a slurry. S2: Pour the slurry into a 300mm×300mm×10mm steel mold (with a release agent applied to the inner wall), place it on a vibration table (frequency 50Hz, amplitude 0.5mm), and vibrate until the surface is flat and no large bubbles overflow. The vibration time is about 5min. Seal the mold with plastic wrap and move it into a constant temperature and humidity curing box (temperature 25±2℃, humidity ≥90%). After standing for 28h, demould it and transfer it to an autoclave. Heat it to 200℃ at 3℃ / min and simultaneously increase the pressure to 1.5MPa. Maintain it at constant temperature and pressure for 6h. After naturally decreasing the pressure and temperature, take it out and transfer it to a 105℃ forced air drying oven to dry it to constant weight to obtain a substrate. S3: Use 200-grit sandpaper to lightly grind the surface of the substrate, then use compressed air to blow it clean. The surface roughness Ra ≤ 5μm, pour the UV coating into the roller coating machine trough, adjust the roller gap to 78μm, and evenly roll it on the substrate surface at a speed of 0.5m / min. Immediately send the coated substrate into the UV curing box (wavelength 365nm, light intensity 120mW / cm 2 ), and cured for 40s to obtain an environmentally friendly fire-resistant lightweight decorative board.

[0101] The hydroxypropyl methylcellulose solution is prepared by uniformly mixing 3 g of hydroxypropyl methylcellulose and 50 g of deionized water.

[0102] Example 3 The environmentally friendly fire-resistant lightweight decorative board of this embodiment includes a substrate and a coating applied on the surface of the substrate. The substrate contains the following raw materials: 300g silica fume, 260g rice husk ash, 350g calcium hydroxide powder, 270g lightweight aggregate, 80g composite fiber, 7g polycarboxylate water reducer, 2g hydroxypropyl methylcellulose, 2g zinc stearate, 45g silicone acrylic emulsion and 460g water; The coating material used in the coating is UV coating material.

[0103] The composite fibers are 50 g of basalt fiber and 30 g of meta-aramid; the diameter of the basalt fiber is 11 μm, the short cut length is 5 mm, and the diameter of the meta-aramid is 15 μm, the short cut length is 5 mm.

[0104] The lightweight aggregate was obtained from Preparation Example 9.

[0105] Before use, rice husk ash undergoes the following pretreatment steps: Place rice husk ash in a sintering furnace, heat it to 700°C at a rate of 5°C / min, activate it for 3 hours, and cool it to room temperature in the furnace to obtain the product.

[0106] The method for preparing the environmentally friendly fire-resistant lightweight decorative board of this embodiment includes the following steps: S1: Slurry preparation: Silica fume, rice husk ash and calcium hydroxide powder were placed in a container and dry-mixed at a stirring speed of 200 rpm for 8 minutes to ensure that there was no agglomeration. Then, silicone acrylic emulsion, water and polycarboxylate water reducer were added. The stirring speed was adjusted to 800 rpm and the mixture was stirred for 10 minutes. Then, composite fiber was added and manually dispersed for 45 seconds until there was no fiber agglomeration. The stirring speed was adjusted to 200 rpm and the mixture was stirred for 3 minutes. Then, lightweight aggregate was added and the mixture was stirred for 8 minutes. Then, hydroxypropyl methylcellulose solution was slowly added dropwise. Then, zinc stearate was added and the stirring speed was adjusted to 300 rpm and the mixture was stirred for 8 minutes to obtain a slurry. S2: Pour the slurry into a 300mm×300mm×10mm steel mold (with a release agent applied to the inner wall), place it on a vibration table (frequency 50Hz, amplitude 0.5mm), and vibrate until the surface is flat and no large bubbles overflow. The vibration time is about 4min. Seal the mold with plastic wrap and move it into a constant temperature and humidity curing box (temperature 25±2℃, humidity ≥90%). After standing for 26h, demould it and transfer it to an autoclave. Heat it to 190℃ at 3℃ / min and simultaneously increase the pressure to 1.4MPa. Maintain it at constant temperature and pressure for 7h. After naturally decreasing the pressure and temperature, take it out and transfer it to a 105℃ forced air drying oven to dry it to constant weight to obtain a substrate. S3: Use 200-grit sandpaper to lightly grind the substrate surface, then use compressed air to clean it. The surface roughness Ra is ≤ 5μm. Pour the UV coating into the roller coating machine trough, adjust the roller gap to 60μm, and evenly roll it on the substrate surface at a speed of 0.75m / min. Immediately send the coated substrate into the UV curing box (wavelength 365nm, light intensity 100mW / cm 2 ), and cured for 50s to obtain an environmentally friendly fire-resistant lightweight decorative board.

[0107] The hydroxypropyl methylcellulose solution is prepared by uniformly mixing 2 g of hydroxypropyl methylcellulose and 30 g of deionized water.

[0108] Example 4 The difference between this embodiment and embodiment 3 is that: The lightweight aggregate was obtained from Preparation Example 10.

[0109] Other details are the same as in Example 3.

[0110] Example 5 The difference between this embodiment and embodiment 4 is that: The lightweight aggregate was obtained from Preparation Example 11.

[0111] Other details are the same as in Example 4.

[0112] Example 6 The difference between this embodiment and embodiment 5 is that: The lightweight aggregate was obtained from Preparation Example 12.

[0113] Other details are the same as in Example 5.

[0114] Example 7 The difference between this embodiment and embodiment 6 is that: The environmentally friendly fire-resistant lightweight decorative board of this embodiment includes a substrate and a composite coating applied on the surface of the substrate. The substrate also includes 10g of aluminum borate whiskers.

[0115] In the method for preparing the environmentally friendly fire-resistant lightweight decorative board of this embodiment, in step S1, when adding the lightweight aggregate, the step of adding aluminum borate whiskers is also included.

[0116] Other details are the same as in Example 6.

[0117] Example 8 The difference between this embodiment and embodiment 7 is that: The environmentally friendly fire-resistant lightweight decorative board of this embodiment includes a substrate and a composite coating applied on the surface of the substrate. The substrate also includes 18g of aluminum borate whiskers.

[0118] In the method for preparing the environmentally friendly fire-resistant lightweight decorative board of this embodiment, in step S1, when adding the lightweight aggregate, the step of adding aluminum borate whiskers is also included.

[0119] Other details are the same as in Example 7.

[0120] Comparative Example 1 The difference between this comparative example and Example 1 is: Before use, the ceramsite was dried at 105°C to constant weight.

[0121] Other details are the same as in Example 1.

[0122] Comparative Example 2 The difference between this comparative example and Example 1 is: Rice husk ash was not pretreated before use.

[0123] Other details are the same as in Example 1.

[0124] Comparative Example 3 The difference between this comparative example and Example 1 is: 50g basalt fiber is used to replace composite fiber.

[0125] Other details are the same as in Example 1.

[0126] Performance testing The performance of the environmentally friendly fire-resistant lightweight decorative panels prepared in Examples 1 to 8 and Comparative Examples 1 to 3 was tested according to JC / T 564.1-2018, GB / T8624-2012, Q / LTZPS001-2022, and GB / T 9286-1998, as shown in Table 1: Table 1 Performance test data of environmentally friendly fire-resistant lightweight decorative panels prepared in Examples 1 to 8 and Comparative Examples 1 to 3

[0127] By analyzing the data in Table 1 in combination with Examples 1 to 8 and Comparative Examples 1 to 3, it can be seen that: As shown in Examples 1-8 and Comparative Example 1, after the surface coating treatment, a protective layer is formed on the ceramsite surface, effectively filling the ceramsite's native micropores, blocking the intrusion pathways for water molecules, and preventing the risk of matrix cracking due to water absorption and expansion. Furthermore, the coating layer and the gelled matrix form a strong interfacial transition zone through bonding or physical entanglement, significantly enhancing stress transfer efficiency, inhibiting water absorption and expansion during autoclaving, and suppressing the initiation of microcracks, thus fundamentally preventing strength degradation caused by weak interfaces.

[0128] On the basis of Example 6, aluminum borate whiskers are introduced, which can withstand tensile stress across both ends of some microcracks, fill the pores of the matrix, block the water absorption path, and transform into a ceramic phase at subsequent high temperatures (reaching 600°C), synergistically strengthening the matrix skeleton with the silica glass phase generated by the coating layer, thereby improving the fire resistance limit.

[0129] It can be seen from Example 1 and Comparative Example 2 that after high-temperature activation of rice husk ash, the organic matter content can be effectively reduced, the weak interface layer can be eliminated, and the content and specific surface area of amorphous silica can be increased, thereby generating a relatively large amount of CSH gel with calcium hydroxide micropowder, reducing the porosity of the matrix, and effectively improving the flexural strength of the substrate and reducing the water absorption rate.

[0130] As demonstrated in Example 1 and Comparative Example 3, the meta-aramid and basalt fiber composite optimizes the material's mechanical behavior through a complementary rigidity-flexibility mechanism. The basalt fiber acts as a rigid framework, bearing the principal stress during the initial loading phase and inhibiting crack initiation. The meta-aramid fiber, as a flexible component, absorbs impact energy through plastic deformation, enhancing crack and impact resistance. The two components form a partially interwoven network within the matrix, forcing crack propagation paths to become more circuitous, significantly improving the material's resistance to deformation.

[0131] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. An environmentally friendly fire-resistant lightweight decorative board, characterized in that: The invention comprises a substrate and a coating applied on the surface of the substrate, wherein the substrate contains the following raw materials in parts by mass: 25-35 parts of silica fume, 20-30 parts of rice husk ash, 30-40 parts of calcium hydroxide powder, 18-35 parts of lightweight aggregate, 5-10 parts of composite fiber, 0.3-1.0 part of polycarboxylate water reducer, 0.1-0.3 part of hydroxypropyl methylcellulose, 0.1-0.3 part of zinc stearate, 3-6 parts of silicone acrylic emulsion and water; The amount of water used is (0.4-0.6) times the total mass of silica fume, rice husk ash and calcium hydroxide powder; The lightweight aggregate is a compound of hollow glass microspheres and ceramsite that have been subjected to two-stage coating treatment; the two-stage coating includes a shell layer and a functional layer, the shell layer is a silane-silicone resin layer; and the functional layer is a magnesium hydroxide-graphene composite flame retardant layer.

2. The environmentally friendly fire-resistant lightweight decorative board according to claim 1, characterized in that: The composite fiber includes basalt fiber and meta-aramid.

3. The environmentally friendly fire-resistant lightweight decorative board according to claim 1, characterized in that: Before use, the rice husk ash is activated at a temperature of 650-750° C. for 2-4 hours and set aside.

4. The environmentally friendly fire-resistant lightweight decorative board according to claim 1, characterized in that: The method for preparing the lightweight aggregate comprises the following steps: S11: uniformly mixing the silane coupling agent, the aqueous silicone resin emulsion, and the ethanol aqueous solution, adjusting the pH to 5.5-6.5, heating to 60-80° C., reacting for 35-45 minutes, and cooling to room temperature to obtain a silane-silicone resin solution; S12: adding ceramsite and hollow glass microspheres to the silane-silicone resin solution, mixing for 15-25 minutes, separating the solid and liquid, and drying to obtain a pre-coated material; S13: uniformly dispersing magnesium hydroxide and graphene in aqueous acrylate, adding a crosslinking agent, and mixing for 15 to 25 minutes to obtain a composite coating liquid; then uniformly applying the composite coating liquid to the surface of the pre-coated object and curing it to obtain a lightweight aggregate.

5. The environmentally friendly fire-resistant lightweight decorative board according to claim 4, characterized in that: The mass ratio of the total mass of the ceramsite and the hollow glass microspheres, the silane-silicone resin solution and the composite coating liquid is 1:(1.5-2.5):(0.25-0.35).

6. The environmentally friendly fire-resistant lightweight decorative board according to claim 5, characterized in that: The ceramsite is subjected to the following simple pretreatment steps before use: The aqueous epoxy resin emulsion, curing agent, propylene glycol methyl ether and water are uniformly mixed to obtain an emulsion; the ceramsite is then immersed in the emulsion for 20 to 30 minutes, solid-liquid separation is performed, and solidification is performed to obtain the product.

7. The environmentally friendly fire-resistant lightweight decorative board according to claim 6, characterized in that: The mass ratio of the waterborne epoxy resin emulsion, the curing agent, propylene glycol methyl ether and water is (15-20): (8-10): (5-7): (60-70).

8. The environmentally friendly fire-resistant lightweight decorative board according to claim 5, characterized in that: The ceramsite undergoes the following deep pretreatment steps before use: The method comprises the following steps: uniformly mixing water glass, nano-silica dispersion, methyltrimethoxysilane hydrolyzate and borax, adjusting the pH value to 7.5-8, and obtaining a homogeneous sol; then immersing the ceramsite in the homogeneous sol, evacuating the mixture to -0.08--0.1 MPa, immersing the mixture for 20-30 minutes, separating the solid and the liquid, drying the mixture at 70-90° C. for 1.5-2.5 hours, continuously heating the mixture to 110-130° C., and drying the mixture to a constant weight.

9. A method according to claim 8, characterized in that: The mass ratio of the sodium silicate in the water glass, the nano-silica in the nano-silica dispersion, the methyltrimethoxysilane in the methyltrimethoxysilane hydrolyzate, and the borax is (28-40): (2-6): (2.5-3.5): (1-2).

10. A method for preparing the environmentally friendly fire-resistant lightweight decorative board according to any one of claims 1 to 9, characterized in that: The steps include: S1: Slurry preparation: Mix silica fume, rice husk ash and calcium hydroxide powder evenly, add silicone acrylic emulsion, water and polycarboxylate water reducer and mix evenly, add composite fiber and lightweight aggregate and mix evenly, then add hydroxypropyl methylcellulose and zinc stearate and mix evenly to obtain slurry; S2: Forming and curing: After vibration forming, pre-curing, autoclaving and drying are carried out in sequence to obtain the base material; S3: Decorative protection: After pre-treatment of the substrate surface, apply the composite coating with a roller.

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