Fireproof and antibacterial diatom ooze decorative plate and preparation method thereof

Abstract

The invention relates to the technical field of diatom ooze decorative plates, in particular to a fireproof and antibacterial diatom ooze decorative plate and a preparation method thereof.The fireproof and antibacterial diatom ooze decorative plate comprises a base material layer, a decorative layer and a fireproof and antibacterial coating which are sequentially arranged from bottom to top; the fireproof and antibacterial coating comprises the following raw materials in parts by weight: 3-6 parts of nano silicon dioxide, 6-10 parts of methacryloyloxyethyl hexadecyl dimethyl ammonium chloride, 20-30 parts of 2-hydroxyethyl methacrylate phosphate, 5-10 parts of [(6-oxo-6H-dibenzo [C, E] [1, 2, 3] triazolo [3, 4-b] pyrimidine-2-yl)-1, 2, 3-triazolo [ The invention relates to a UV (ultraviolet) photoinitiator, which is prepared from the following components in parts by weight: 10 to 20 parts of 2, 2] oxophosphahexane-6-yl) methyl] succinic acid bis (2-hydroxyethyl) ester, 80 to 100 parts of polyurethane acrylate resin, 3 to 5 parts of photoinitiator and 20 to 40 parts of organic solvent. According to the fireproof and antibacterial diatom ooze decorative plate and the preparation method thereof, on the premise of ensuring the mechanical strength, the fireproof and antibacterial diatom ooze decorative plate not only has an excellent decorative effect, but also has fireproof performance and antibacterial performance at the same time.

Description

Technical Field

[0001] This invention relates to the field of diatomaceous earth decorative panel technology, and in particular to a fireproof and antibacterial diatomaceous earth decorative panel and its preparation method. Background Technology

[0002] Diatomaceous earth decorative panels are environmentally friendly interior decorative panels made primarily of diatomaceous earth through inorganic-organic composite processes and hot-press molding. They have gained widespread attention in the wall decoration field due to the air-purifying and moisture-regulating properties resulting from the natural microporous structure of diatomaceous earth.

[0003] As the application scenarios extend from residential spaces to public buildings such as schools, hospitals, and office buildings that have higher requirements for environmental hygiene and safety, the market has put forward higher requirements for this type of board. It is not only required that it has mechanical strength to withstand a certain amount of pressure and impact and is not easily damaged or deformed, but it is also expected that it can have fire resistance and antibacterial properties at the same time.

[0004] To impart fire resistance and antibacterial properties to diatomaceous earth panels, existing technologies mainly follow a design path of "adding functions externally," specifically manifested as: (1) coating the surface of the panel with a functional topcoat. For example, by adding flame retardants and antibacterial agents to the surface coating, fire resistance and antibacterial properties are achieved; (2) introducing an independent intermediate functional layer specifically to carry the flame retardant and antibacterial components. The above technical means all aim to integrate functions into the product in a modular way through physical superposition. However, such functional layer superposition technology is limited by the selection of raw material formulations, resulting in limited fire resistance and antibacterial properties of the prepared diatomaceous earth decorative panels.

[0005] Meanwhile, the large amount of fillers and opaque components added by existing technologies to achieve functions such as fire resistance and antibacterial properties result in excessive surface coverage and loss of transparency, making it impossible to clearly present the texture and color of the built-in decorative layer. Ultimately, it is difficult for the decorative panel to achieve excellent decorative effects while ensuring excellent fire resistance and antibacterial properties.

[0006] In summary, diatomaceous earth decorative panels prepared by existing technologies generally suffer from insufficient fire resistance and antibacterial properties, and it is difficult to achieve excellent decorative effects. Summary of the Invention

[0007] The purpose of this invention is to propose a fireproof and antibacterial diatomaceous earth decorative board and its preparation method, which is beneficial to not only have excellent decorative effect while ensuring mechanical strength, but also have fireproof and antibacterial properties at the same time, so as to overcome the shortcomings of the prior art.

[0008] To achieve this objective, the present invention adopts the following technical solution: A fireproof and antibacterial diatomaceous earth decorative panel includes a substrate layer, a decorative layer, and a fireproof and antibacterial coating layer arranged sequentially from bottom to top. According to the mass percentage, the raw materials of the substrate layer include 45-50 parts of diatomaceous earth, 30-43 parts of composite flame retardant, 8-10 parts of polyvinyl alcohol, 3-5 parts of vinyl acetate-ethylene copolymer emulsion, 0.8-1.2 parts of crosslinking agent, 1.5-2.5 parts of silane coupling agent, 0.5-1 parts of chopped glass fiber, and 18-28 parts of water; The composite flame retardant includes aluminum hydroxide, ammonium polyphosphate, and pentaerythritol; According to the mass fraction, the raw materials of the fireproof and antibacterial coating include 3-6 parts of nano-silica, 6-10 parts of methacryloyloxyethyl hexadecyl dimethyl ammonium chloride, 20-30 parts of 2-hydroxyethyl methacrylate phosphate, 10-20 parts of [(6-oxo-6H-dibenzo[C,E][1,2]oxophosphoroxane-6-yl)methyl]bis(2-hydroxyethyl) succinate, 80-100 parts of polyurethane acrylate resin, 3-5 parts of photoinitiator, and 20-40 parts of organic solvent.

[0009] Furthermore, according to the mass ratio, the mixing ratio of the aluminum hydroxide, the ammonium polyphosphate and the pentaerythritol in the composite flame retardant is (10-15):(15-20):(5-8).

[0010] Furthermore, the crosslinking agent is glutaraldehyde.

[0011] Furthermore, the polyurethane acrylate resin is a hexafunctional polyurethane acrylate resin.

[0012] Furthermore, the silane coupling agent includes any one of dodecyltrimethylsilane, vinyltrimethoxysilane, and γ-methacryloyloxypropyltrimethoxysilane.

[0013] Furthermore, the photoinitiator comprises 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and 1-hydroxycyclohexylphenyl ketone.

[0014] Furthermore, it also includes an adhesion-enhancing coating located between the decorative layer and the fire-retardant and antibacterial coating; The raw materials for the adhesion-enhancing coating, calculated by weight, include 90-110 parts of bisphenol F type epoxy resin, 2-4 parts of γ-(2,3-epoxypropoxy)propyltrimethoxysilane, 30-45 parts of phenolic amine curing agent, and 10-30 parts of propylene glycol methyl ether acetate.

[0015] A method for preparing a fire-resistant and antibacterial diatomaceous earth decorative panel, comprising the following steps: S1. Mix the diatomaceous earth and composite flame retardant according to the formula until uniform to obtain a mixed powder; Add the prescribed amount of silane coupling agent to the mixed powder and stir at 5000-8000 rpm for 30-60 min to obtain the pretreated powder; After mixing the pretreated powder with the prescribed amount of water, add the prescribed amount of polyvinyl aldehyde and vinyl acetate-ethylene copolymer emulsion and mix evenly to obtain the intermediate slurry. Add the prescribed amount of chopped glass fiber to the intermediate slurry and mix evenly. Then add the prescribed amount of crosslinking agent and mix evenly to obtain the molding slurry. S2. After uniformly mixing the formulated amounts of bisphenol F type epoxy resin, γ-(2,3-epoxypropoxy)propyltrimethoxysilane, phenolic amine curing agent and propylene glycol methyl ether acetate, an adhesion-enhancing coating is obtained. S3. After uniformly mixing the formulated amounts of nano-silica, methacryloyloxyethyl hexadecyl dimethyl ammonium chloride, 2-hydroxyethyl methacrylate phosphate, [(6-oxo-6H-dibenzo[C,E][1,2]oxophosphoroxane-6-yl)methyl]succinate bis(2-hydroxyethyl) ester, polyurethane acrylate resin, photoinitiator and organic solvent, a fire-retardant and antibacterial coating is obtained. S4. The molding slurry is injected into the mold, and after hot pressing and demolding, an intermediate plate is obtained; the intermediate plate is cured to obtain the substrate layer; Wood grain decorative paper is hot-pressed onto the surface of the substrate layer using a hot press to form a decorative layer; After sanding the upper surface of the decorative layer, apply an adhesion-enhancing coating and leave it at room temperature until the adhesion-enhancing coating is surface dry to form an adhesion-enhancing coating. Fire-retardant and antibacterial coating is applied to the surface of the adhesion-enhancing coating, and then dried and UV-cured in sequence to form a fire-retardant and antibacterial coating and obtain a fire-retardant and antibacterial diatomaceous earth decorative board.

[0016] Furthermore, in step S4, the curing temperature is 60-70℃ and the curing time is 24-48h.

[0017] The technical solution provided by this invention may include the following beneficial effects: 1. The raw materials for the fire-retardant and antibacterial coating include nano-silica, methacryloyloxyethyl hexadecyl dimethyl ammonium chloride, 2-hydroxyethyl methacrylate phosphate, [(6-oxo-6H-dibenzo[C,E][1,2]oxophosphoric acid hexane-6-yl)methyl]succinate bis(2-hydroxyethyl) ester, polyurethane acrylate resin, photoinitiator, and organic solvent. Among these, [(6-oxo-6H-dibenzo[C,E][1,2]oxophosphoric acid hexane-6-yl)methyl]succinate bis(2-hydroxyethyl) ester, as a highly efficient intumescent flame retardant, decomposes upon heating to generate polyphosphoric acid, catalyzing the formation of char and releasing non-flammable gases that cause the char layer to expand. 2-hydroxyethyl methacrylate phosphate, as an acid source supplement, strengthens the adhesion between the char layer and the substrate layer, preventing peeling. Simultaneously, methacryloyloxyethyl hexadecyl dimethyl ammonium chloride, utilizing its quaternary ammonium salt structure, undergoes Hoffmann degradation at high temperatures, decomposing to produce non-flammable gases such as nitrogen and ammonia. The aforementioned non-flammable gases can dilute the concentration of oxygen and combustible gases in the flame zone, thereby inhibiting the combustion chain reaction and ultimately forming a heat-insulating and oxygen-barrier expanded char layer, achieving a flame-retardant effect.

[0018] 2. The raw material for the fire-retardant and antibacterial coating in this technical solution includes methacryloyloxyethylhexadecyl dimethylammonium chloride. Methacryloxyethylhexadecyl dimethylammonium chloride adsorbs onto the negatively charged cell wall surface through its positively charged quaternary ammonium salt structure, diffuses and penetrates the cell wall, binding to the cell membrane and disrupting its components, thus allowing intracellular substances such as potassium to be released. + The leakage of DNA and RNA leads to bacterial death, achieving rapid bacterial elimination. In addition to its strong bactericidal power, this quaternary ammonium salt structure can also effectively kill bacteria, fungi, spores, and viruses, exhibiting good antibacterial effects and broad-spectrum antibacterial activity.

[0019] 3. In this technical solution, the particle size of nano-silica in the fire-retardant and antibacterial coating is controlled to be much smaller than the wavelength of visible light, effectively suppressing light scattering physically. Simultaneously, all liquid functional monomers can form an optically homogeneous and stable solution with polyurethane acrylate resin in an organic solvent, and each component is colorless or light yellow, ensuring a pure base color. After photocuring, a uniform amorphous cross-linked network is formed, avoiding optical inhomogeneity caused by phase separation, thus achieving overall transparency in the resulting fire-retardant and antibacterial coating. This transparency allows the patterns and colors of the decorative layer at the bottom to be fully and clearly displayed, thereby improving the decorative effect. Detailed Implementation

[0020] This technical solution provides a fireproof and antibacterial diatomaceous earth decorative panel, which includes a substrate layer, a decorative layer and a fireproof and antibacterial coating arranged sequentially from bottom to top. According to the mass percentage, the raw materials of the substrate layer include 45-50 parts of diatomaceous earth, 30-43 parts of composite flame retardant, 8-10 parts of polyvinyl alcohol, 3-5 parts of vinyl acetate-ethylene copolymer emulsion, 0.8-1.2 parts of crosslinking agent, 1.5-2.5 parts of silane coupling agent, 0.5-1 parts of chopped glass fiber, and 18-28 parts of water; The composite flame retardant includes aluminum hydroxide, ammonium polyphosphate, and pentaerythritol; According to the mass fraction, the raw materials of the fireproof and antibacterial coating include 3-6 parts of nano-silica, 6-10 parts of methacryloyloxyethyl hexadecyl dimethyl ammonium chloride, 20-30 parts of 2-hydroxyethyl methacrylate phosphate, 10-20 parts of [(6-oxo-6H-dibenzo[C,E][1,2]oxophosphoroxane-6-yl)methyl]bis(2-hydroxyethyl) succinate, 80-100 parts of polyurethane acrylate resin, 3-5 parts of photoinitiator, and 20-40 parts of organic solvent.

[0021] To address the common technical problems of insufficient fire resistance and antibacterial properties in diatomaceous earth decorative panels, and the difficulty in achieving excellent decorative effects, this technical solution proposes a fire-resistant and antibacterial diatomaceous earth decorative panel. By selecting appropriate raw materials for the formula, it is possible to achieve not only excellent decorative effects but also fire resistance and antibacterial properties while ensuring mechanical strength, thus meeting practical application needs.

[0022] Specifically, the composite flame retardant in the substrate layer of this technical solution includes aluminum hydroxide, ammonium polyphosphate, and pentaerythritol. When exposed to fire, ammonium polyphosphate acts as both an acid and gas source, rapidly decomposing and catalyzing the dehydration and carbonization of the material, releasing non-combustible gases. Simultaneously, pentaerythritol, as a carbon source, undergoes esterification, dehydration, and cross-linking reactions under the influence of polyphosphate, generating a porous carbonaceous skeleton. Aluminum hydroxide, acting as a gas source and efficient filler, decomposes first at a relatively low temperature (approximately 200°C), absorbing heat and releasing water vapor. This not only slows down the heating of the substrate layer but also allows the released gas to participate in expansion, causing the forming carbon layer to foam and expand, ultimately forming a thicker, denser, and stronger carbonaceous foam layer than the original substrate layer, thus effectively preventing the spread of flames and the transfer of heat.

[0023] Furthermore, the raw materials for the fire-retardant and antibacterial coating include nano-silica, methacryloyloxyethyl hexadecyl dimethyl ammonium chloride, 2-hydroxyethyl methacrylate phosphate, [(6-oxo-6H-dibenzo[C,E][1,2]oxophosphoroxane-6-yl)methyl]succinate bis(2-hydroxyethyl) ester, polyurethane acrylate resin, photoinitiator, and organic solvent. Among these, [(6-oxo-6H-dibenzo[C,E][1,2]oxophosphoroxane-6-yl)methyl]succinate bis(2-hydroxyethyl) ester, as a highly efficient intumescent flame retardant, decomposes upon heating to generate polyphosphoric acid, catalyzing the formation of char and releasing non-flammable gases that cause the char layer to expand. 2-hydroxyethyl methacrylate phosphate, as an acid source supplement, strengthens the adhesion between the char layer and the substrate layer, preventing peeling. Simultaneously, methacryloyloxyethyl hexadecyl dimethyl ammonium chloride, utilizing its quaternary ammonium salt structure, undergoes Hoffmann degradation at high temperatures, decomposing to produce non-flammable gases such as nitrogen and ammonia. The aforementioned non-flammable gases can dilute the concentration of oxygen and combustible gases in the flame zone, thereby inhibiting the combustion chain reaction and ultimately forming a heat-insulating and oxygen-barrier expanded char layer, achieving a flame-retardant effect.

[0024] In summary, this technical solution utilizes a fire-retardant and antibacterial coating as the first line of fire protection, allowing the substrate layer to directly face internal heat sources or the spread of fire, effectively delaying the inward transfer of heat, thereby constructing a fire-resistant system that is layered and protected from the outside in, giving the fire-retardant and antibacterial diatomaceous earth decorative board high fire resistance.

[0025] Secondly, the raw materials for the substrate layer in this technical solution also include diatomaceous earth, polyvinyl alcohol, vinyl acetate-ethylene copolymer emulsion, crosslinking agent, silane coupling agent, chopped glass fiber, and water. Diatomaceous earth, as a rigid porous framework, provides basic hardness and support; chopped glass fiber, as fiber reinforcement, disperses stress, prevents cracking, and further improves hardness and impact resistance; polyvinyl alcohol and vinyl acetate-ethylene copolymer emulsion react with the crosslinking agent to form a three-dimensional network structure, which encapsulates the chopped glass fiber and composite flame retardant; the silane coupling agent, through molecular bridging, greatly improves the interfacial bonding force between inorganic diatomaceous earth, chopped glass fiber, and organic resins such as polyvinyl alcohol, ensuring effective stress transfer and preventing interfacial delamination. Ultimately, the above raw materials work together to form a whole that is both supported by an inorganic rigid framework and firmly bonded by a flexible crosslinked network, thus achieving a balance of rigidity and flexibility, which is beneficial for improving mechanical strength.

[0026] The fire-retardant and antibacterial coating of this technical solution also includes nano-silica, methacryloyloxyethyl hexadecyl dimethyl ammonium chloride, 2-hydroxyethyl methacrylate phosphate, [(6-oxo-6H-dibenzo[C,E][1,2]oxophosphazenehexane-6-yl)methyl]succinate bis(2-hydroxyethyl) ester, polyurethane acrylate resin, photoinitiator, and organic solvent. The photoinitiator absorbs ultraviolet light to generate active free radicals, initiating copolymerization and crosslinking reactions between the polyurethane acrylate resin and its contained urethane segments (soft segments), methacryloyloxyethyl hexadecyl dimethyl ammonium chloride, and 2-hydroxyethyl methacrylate phosphate, forming a highly crosslinked three-dimensional network structure. In this network structure, the soft segments of the polyurethane acrylate resin and the long-chain alkyl groups of methacryloyloxyethyl hexadecyl dimethyl ammonium chloride together provide flexibility and internal plasticizing effect; while the uniformly dispersed nano-silica, as rigid particles, significantly improves the hardness, wear resistance, and density of the coating through physical reinforcement and the interaction between surface hydroxyl groups and the polymer network. Ultimately, the system achieves a dense organic-inorganic hybrid coating through the synergistic effect of microphase separation of the soft and hard segments of polyurethane, nanoparticle reinforcement, and chemical bonding of functional monomers. This results in both good hardness and flexibility, achieving a balance between rigidity and flexibility, which is beneficial for improving mechanical strength.

[0027] In summary, this technical solution achieves a balance of rigidity and flexibility in the diatomaceous earth decorative board by combining hardness and flexibility in both the substrate layer and the surface layer. This improves mechanical strength, enables the board to withstand certain pressure and impact, and makes it less prone to breakage or deformation.

[0028] Furthermore, the raw material for the fire-retardant and antibacterial coating in this technical solution includes methacryloyloxyethylhexadecyl dimethylammonium chloride. Methacryloxyethylhexadecyl dimethylammonium chloride adsorbs onto the negatively charged cell wall surface through its positively charged quaternary ammonium salt structure, diffuses and penetrates the cell wall, binding to the cell membrane and disrupting its components, thus allowing intracellular substances such as potassium to be released. + The leakage of DNA and RNA leads to bacterial death, achieving rapid bacterial elimination. In addition to its strong bactericidal power, this quaternary ammonium salt structure can also effectively kill bacteria, fungi, spores, and viruses, exhibiting good antibacterial effects and broad-spectrum antibacterial activity.

[0029] In addition, as described above, during the photocuring process of polyurethane acrylate resin and other resins initiated by the photoinitiator, nano-silica will be dispersed in the three-dimensional network structure. During this dispersion process, some nano-silica will be exposed or protrude from the surface of the three-dimensional network structure (i.e., the fireproof and antibacterial coating), thereby forming a micro-nano rough structure with the polyurethane acrylate resin and other resins. The micro-nano rough structure is beneficial to improving antibacterial properties. The specific principle is as follows: (1) The micro-nano rough structure and micro-nano porous structure greatly increase their specific surface area, allowing antibacterial components (such as silver ions and zinc ions) to be more fully exposed on the surface, thereby providing more abundant reactive sites. The increase of the above-mentioned reactive sites allows the antibacterial components to come into contact with bacteria more efficiently and initiate a reaction, thereby accelerating the killing or growth inhibition process of bacteria. (2) The sharp edges of the micro-nano rough structure can directly pierce the cell wall or biofilm of the bacteria when in contact with bacteria, causing physical damage to the bacteria, thereby providing additional protection for antibacterial performance.

[0030] Finally, in this technical solution, the particle size of nano-silica in the fire-retardant and antibacterial coating is controlled to be much smaller than the wavelength of visible light, effectively suppressing light scattering physically. Simultaneously, all liquid functional monomers can form an optically homogeneous and stable solution with polyurethane acrylate resin in an organic solvent, and each component is colorless or light yellow, ensuring a pure base color. After photocuring, a uniform amorphous cross-linked network is formed, avoiding optical inhomogeneity caused by phase separation, thus achieving overall transparency in the resulting fire-retardant and antibacterial coating. This transparency allows the patterns and colors of the decorative layer at the bottom to be fully and clearly displayed, thereby enhancing the decorative effect.

[0031] It should be noted that the vinyl acetate-ethylene copolymer emulsion and polyvinyl alcohol in the substrate layer effectively fill the porous structure of the diatomaceous earth itself and form a three-dimensional network under the action of the crosslinking agent. This not only blocks the penetration of water molecules but also reduces the capillary channels and microcracks inside the substrate layer, making it difficult for water vapor to diffuse through. At the same time, the silanol groups produced after the hydrolysis of the silane coupling agent can react with the hydroxyl groups on the surface of inorganic materials such as diatomaceous earth and chopped glass fibers, firmly grafting their own long organic chains (usually hydrophobic alkyl chains) onto the surface of diatomaceous earth and chopped glass fibers, changing them from hydrophilic to hydrophobic. This reduces the adsorption of moisture by the substrate layer, thus giving the substrate layer a certain degree of moisture resistance.

[0032] Preferably, the organic solvent can be propylene glycol methyl ether acetate, dipropylene glycol methyl ether, and ethanol, etc., and the specific type is not limited here.

[0033] To further explain, based on the mass ratio, the mixing ratio of the aluminum hydroxide, the ammonium polyphosphate and the pentaerythritol in the composite flame retardant is (10-15):(15-20):(5-8).

[0034] This technical solution limits the mixing ratio of aluminum hydroxide, ammonium polyphosphate, and pentaerythritol. By using this mixing ratio, a sufficiently thick, dense, and robust carbonaceous foam insulation layer can be constructed with optimal economic dosage, thereby achieving excellent fire resistance at a lower cost.

[0035] To further clarify, the crosslinking agent is glutaraldehyde.

[0036] Glutaraldehyde can react with polyvinyl acetal and vinyl acetate-ethylene copolymer emulsion to form a three-dimensional network structure. This three-dimensional network structure effectively locks the polymer chains, preventing them from swelling and dissolving in water or solvents, thereby improving the water resistance and moisture resistance of the substrate layer. Simultaneously, the three-dimensional network structure increases the cohesive strength and abrasion resistance of the substrate layer, making it harder and denser, while maintaining good flexibility (due to the certain length of the aliphatic chains in glutaraldehyde), making the substrate layer less prone to cracking and extending the service life of diatomaceous earth decorative panels.

[0037] To further clarify, the polyurethane acrylate resin is a hexafunctional polyurethane acrylate resin.

[0038] This technical solution, by limiting the polyurethane acrylate resin to a hexafunctional polyurethane acrylate resin, facilitates the construction of a three-dimensional network with high cross-linking density. This results in a fire-retardant and antibacterial coating that exhibits high hardness and excellent wear resistance after photocuring (i.e., UV curing). At the same time, the soft segments in the hexafunctional polyurethane acrylate resin molecule provide necessary toughness buffer for this rigid network, ultimately achieving a balance between high hardness and toughness in the coating. This meets the requirements of high-performance fire-retardant and antibacterial coatings for surface strength and durability.

[0039] The hexafunctional polyurethane acrylate resin can be either Sartoma CN9006 or Boxin B-615; the specific type is not limited here.

[0040] To further clarify, the silane coupling agent includes any one of dodecyltrimethylsilane, vinyltrimethoxysilane, and γ-methacryloyloxypropyltrimethoxysilane.

[0041] Dodecyltrimethylsilane, vinyltrimethoxysilane, and γ-methacryloyloxypropyltrimethoxysilane can all significantly improve the interfacial bonding between inorganic diatomaceous earth, chopped glass fibers, and organic resins such as polyvinyl aldehyde through molecular bridging, ensuring effective stress transfer and preventing interfacial delamination. Therefore, this technical solution will be limited to any one of these three, which is beneficial to ensuring the performance of diatomaceous earth decorative panels.

[0042] To further explain, the photoinitiator includes 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and 1-hydroxycyclohexylphenyl ketone.

[0043] 2,4,6-Trimethylbenzoyl-diphenylphosphine oxide primarily absorbs long-wave ultraviolet light (UVA, approximately 380-420 nm), exhibiting strong penetrating power and responsible for deep curing of the coating, preventing the substrate layer from becoming sticky. Meanwhile, 1-hydroxycyclohexylphenyl ketone primarily absorbs short-wave ultraviolet light (UVA, approximately 250-350 nm), possessing high energy and responsible for rapid surface curing of the coating, forming a hard surface. This combination of long- and short-wave initiators not only ensures uniform and thorough curing of coatings of varying thicknesses from the surface to the bottom, but also improves curing efficiency and the overall performance of the coating.

[0044] Further explanation: It also includes an adhesion-enhancing coating, which is located between the decorative layer and the fire-retardant and antibacterial coating; The raw materials for the adhesion-enhancing coating, calculated by weight, include 90-110 parts of bisphenol F type epoxy resin, 2-4 parts of γ-(2,3-epoxypropoxy)propyltrimethoxysilane, 30-45 parts of phenolic amine curing agent, and 10-30 parts of propylene glycol methyl ether acetate.

[0045] This technical solution, by setting an adhesion-enhancing coating, helps to strengthen the bond between the decorative layer and the fire-retardant and antibacterial coating, preventing the fire-retardant and antibacterial coating from peeling off during use and extending the service life of the fire-retardant and antibacterial diatomaceous earth decorative panel.

[0046] Furthermore, the raw materials for the adhesion-enhancing coating include γ-(2,3-epoxypropoxy)propyltrimethoxysilane. During the storage and application of the adhesion-enhancing coating, moisture in the air can cause the second silane coupling agent to hydrolyze and generate silanol. The silanol can form covalent bonds with the hydroxyl groups on the surface of the polished decorative layer. Meanwhile, the epoxy groups in γ-(2,3-epoxypropoxy)propyltrimethoxysilane can react with the hydroxyl groups in raw materials such as [(6-oxo-6H-dibenzo[C,E][1,2]oxophosphoroxane-6-yl)methyl]bis(2-hydroxyethyl) succinate in the fire-retardant and antibacterial coating to form covalent bonds, thereby improving the bonding strength between the decorative layer and the fire-retardant and antibacterial coating. Meanwhile, the epoxy groups in γ-(2,3-epoxypropoxy)propyltrimethoxysilane can react with the hydroxyl groups in [(6-oxo-6H-dibenzo[C,E][1,2]oxophosphoroxane-6-yl)methyl]bis(2-hydroxyethyl) succinate in the fire-retardant and antibacterial coating, thus fixing them and avoiding the problem that [(6-oxo-6H-dibenzo[C,E][1,2]oxophosphoroxane-6-yl)methyl]bis(2-hydroxyethyl) succinate is prone to migration during use because it has not cross-linked and cured with the other raw materials in the fire-retardant and antibacterial coating, thus ensuring the long-term effectiveness of its effect.

[0047] The manufacturer of the bisphenol F type epoxy resin is Zhilun New Material Technology (Xi'an) Co., Ltd., and the model number is ZLF-160B; the phenolic amine curing agent is T-31 curing agent.

[0048] A method for preparing a fire-resistant and antibacterial diatomaceous earth decorative panel, comprising the following steps: S1. Mix the diatomaceous earth and composite flame retardant according to the formula until uniform to obtain a mixed powder; Add the prescribed amount of silane coupling agent to the mixed powder and stir at 5000-8000 rpm for 30-60 min to obtain the pretreated powder; After mixing the pretreated powder with the prescribed amount of water, add the prescribed amount of polyvinyl aldehyde and vinyl acetate-ethylene copolymer emulsion and mix evenly to obtain the intermediate slurry. Add the prescribed amount of chopped glass fiber to the intermediate slurry and mix evenly. Then add the prescribed amount of crosslinking agent and mix evenly to obtain the molding slurry. S2. After uniformly mixing the formulated amounts of bisphenol F type epoxy resin, γ-(2,3-epoxypropoxy)propyltrimethoxysilane, phenolic amine curing agent and propylene glycol methyl ether acetate, an adhesion-enhancing coating is obtained. S3. After uniformly mixing the formulated amounts of nano-silica, methacryloyloxyethyl hexadecyl dimethyl ammonium chloride, 2-hydroxyethyl methacrylate phosphate, [(6-oxo-6H-dibenzo[C,E][1,2]oxophosphoroxane-6-yl)methyl]succinate bis(2-hydroxyethyl) ester, polyurethane acrylate resin, photoinitiator and organic solvent, a fire-retardant and antibacterial coating is obtained. S4. The molding slurry is injected into the mold, and after hot pressing and demolding, an intermediate plate is obtained; the intermediate plate is cured to obtain the substrate layer; Wood grain decorative paper is hot-pressed onto the surface of the substrate layer using a hot press to form a decorative layer; After sanding the upper surface of the decorative layer, apply an adhesion-enhancing coating and leave it at room temperature until the adhesion-enhancing coating is surface dry to form an adhesion-enhancing coating. Fire-retardant and antibacterial coating is applied to the surface of the adhesion-enhancing coating, and then dried and UV-cured in sequence to form a fire-retardant and antibacterial coating and obtain a fire-retardant and antibacterial diatomaceous earth decorative board.

[0049] This technical solution also proposes a method for preparing fireproof and antibacterial diatomaceous earth decorative panels. The preparation method is simple and easy to operate. While ensuring the decorative effect, it can also have both fireproof and antibacterial properties.

[0050] It should be noted that commercially available wood grain decorative paper is typically made by impregnating decorative base paper with thermosetting resins such as melamine-formaldehyde resin. The base paper substrate is primarily made of wood pulp, and the core component of wood pulp, natural cellulose, contains abundant hydroxyl functional groups in its molecular structure. In this technical solution, by sanding the upper surface of the decorative layer (i.e., the wood grain decorative paper), the dense thermosetting resin coating is effectively removed, exposing the inherent active hydroxyl groups in the base paper fibers. The silanol generated from the hydrolysis of the silane coupling agent (such as γ-(2,3-epoxypropoxy)propyltrimethoxysilane) in the adhesion-enhancing coating can undergo a condensation reaction with the exposed cellulose hydroxyl groups, forming strong Si-OC covalent bonds, thus enhancing the interfacial bonding strength between the decorative layer and the adhesion-enhancing coating.

[0051] It should be further noted that when the adhesion-enhancing coating is left to dry to the surface at room temperature, the resulting coating has a certain degree of dryness but is not completely dry, and its interfacial chemical activity is at its highest. Applying a fire-retardant and antibacterial coating to the surface of this surface-dry adhesion-enhancing coating is beneficial for the interlayer bonding between the two coatings.

[0052] To further explain, in step S4, the curing temperature is 60-70℃ and the curing time is 24-48h.

[0053] This technical solution limits the curing temperature and time, allowing the organic binders (such as polyvinyl alcohol and vinyl acetate-ethylene copolymer emulsion) and crosslinking agents (such as glutaraldehyde) inside the board to fully and slowly complete the reaction, and allowing residual moisture to escape evenly, so as to achieve stable final strength and dimensions.

[0054] The technical solution of the present invention will be further illustrated below through specific embodiments.

[0055] Performance testing Surface effect: Observe the decorative effect of the fireproof and antibacterial diatomaceous earth decorative board with the naked eye.

[0056] Mechanical strength: Bending strength and impact strength were tested according to the test methods in GB / T 17657-2022 Test Methods for Physical and Chemical Properties of Wood-based Panels and Decorative Wood-based Panels.

[0057] Fire resistance performance: Fire resistance performance was tested according to GB 8624-2012 (Classification of Combustion Performance of Building Materials).

[0058] Antibacterial rate: Sterilize 5cm×5cm fireproof and antibacterial diatomaceous earth decorative panels for later use; 5×10 4 CFU test bacterial suspension was inoculated onto the surface of a sterilized fireproof and antibacterial diatomaceous earth decorative panel, covered with sterilized plastic wrap, and placed in a constant temperature incubator at 37°C for 2 hours. After incubation, the sample and the bacterial suspension in the plastic wrap were washed onto a petri dish with sterile phosphate-buffered saline, diluted 10 times, and then inoculated onto a sterile petri dish. The dish was then placed in a constant temperature incubator at 37°C for 24 hours, and the antibacterial rate was calculated.

[0059] Example 1 S1. Mix 48 parts of diatomaceous earth and 35 parts of composite flame retardant by mass to obtain a mixed powder; wherein, by mass ratio, the mixing ratio of aluminum hydroxide, ammonium polyphosphate and pentaerythritol in the composite flame retardant is 2:3:1. Add 2 parts of the formula amount of dodecyltrimethylsilane to the mixed powder and stir at 8000 rpm for 45 min to obtain the pretreated powder; After mixing the pretreated powder with 23 parts of water evenly, add the formulated amount of polyvinyl aldehyde 8 and 4 parts of vinyl acetate-ethylene copolymer emulsion and mix evenly to obtain intermediate slurry. Add 0.8 parts of the formulated amount of chopped glass fiber to the intermediate slurry and mix evenly. Then add 1 part of the formulated amount of glutaraldehyde and mix evenly to obtain the molding slurry. S2. Mix 100 parts by weight of bisphenol F epoxy resin, 4 parts by weight of γ-(2,3-epoxypropoxy)propyltrimethoxysilane, 40 parts by weight of phenolic amine curing agent, and 20 parts by weight of propylene glycol methyl ether acetate to obtain an adhesion-enhancing coating; the manufacturer of bisphenol F epoxy resin is Zhilun New Material Technology (Xi'an) Co., Ltd., and the model is ZLF-160B; the phenolic amine curing agent is T-31 curing agent; S3. Mix 4 parts of nano-silica, 8 parts of methacryloyloxyethyl hexadecyl dimethyl ammonium chloride, 25 parts of 2-hydroxyethyl methacrylate phosphate, 15 parts of [(6-oxo-6H-dibenzo[C,E][1,2]oxophosphorylhexane-6-yl)methyl]succinate bis(2-hydroxyethyl) ester, 90 parts of hexafunctional polyurethane acrylate resin, 4 parts of photoinitiator (a mixture of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and 1-hydroxycyclohexylphenyl ketone in a 1:1 mass ratio), and 30 parts of propylene glycol methyl ether acetate evenly to obtain a fire-retardant and antibacterial coating; the hexafunctional polyurethane acrylate resin is Sartoma CN9006. S4. The molding slurry is injected into the mold, and after hot pressing and demolding, an intermediate board is obtained; the intermediate board is cured at 60°C for 48 hours to obtain the substrate layer; Wood grain decorative paper is hot-pressed onto the surface of the substrate layer using a hot press to form a decorative layer; After sanding the upper surface of the decorative layer, apply an adhesion-enhancing coating and leave it at room temperature until the adhesion-enhancing coating is surface dry to form an adhesion-enhancing coating. Fire-retardant and antibacterial coating is applied to the surface of the adhesion-enhancing coating, and then dried and UV-cured in sequence to form a fire-retardant and antibacterial coating and obtain a fire-retardant and antibacterial diatomaceous earth decorative board.

[0060] Example 2 S1. Mix 45 parts of diatomaceous earth and 32 parts of composite flame retardant by mass to obtain a mixed powder; wherein, by mass ratio, the mixing ratio of aluminum hydroxide, ammonium polyphosphate and pentaerythritol in the composite flame retardant is 2:4:1. Add 1.5 parts of the formulated amount of vinyltrimethoxysilane to the mixed powder and stir at 5000 rpm for 60 min to obtain the pretreated powder; After mixing the pretreated powder with 20 parts of water, add 8 parts of polyvinyl aldehyde and 3 parts of vinyl acetate-ethylene copolymer emulsion according to the formula and mix evenly to obtain intermediate slurry. Add 0.5 parts of the formulated amount of chopped glass fiber to the intermediate slurry and mix evenly. Then add 0.8 parts of the formulated amount of glutaraldehyde and mix evenly to obtain the molding slurry. S2. After uniformly mixing 90 parts of bisphenol F type epoxy resin, 3 parts of γ-(2,3-epoxypropoxy)propyltrimethoxysilane, 35 parts of phenolic amine curing agent, and 20 parts of propylene glycol methyl ether acetate according to the weight parts, an adhesion-enhancing coating is obtained; the manufacturer of bisphenol F type epoxy resin is Zhilun New Material Technology (Xi'an) Co., Ltd., and the model is ZLF-160B; the phenolic amine curing agent is T-31 curing agent; S3. Mix 3 parts of nano-silica, 7 parts of methacryloyloxyethyl hexadecyl dimethyl ammonium chloride, 25 parts of 2-hydroxyethyl methacrylate phosphate, 10 parts of [(6-oxo-6H-dibenzo[C,E][1,2]oxophosphorylhexane-6-yl)methyl]succinate bis(2-hydroxyethyl) ester, 100 parts of hexafunctional polyurethane acrylate resin, 3 parts of photoinitiator (mixed with 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and 1-hydroxycyclohexylphenyl ketone in a 1:1 mass ratio), and 25 parts of ethanol evenly to obtain a fire-retardant and antibacterial coating; the hexafunctional polyurethane acrylate resin is Boxin B-615. S4. The molding slurry is injected into the mold, and after hot pressing and demolding, an intermediate board is obtained; the intermediate board is cured at 70°C for 40 hours to obtain the substrate layer; Wood grain decorative paper is hot-pressed onto the surface of the substrate layer using a hot press to form a decorative layer; After sanding the upper surface of the decorative layer, apply an adhesion-enhancing coating and leave it at room temperature until the adhesion-enhancing coating is surface dry to form an adhesion-enhancing coating. Fire-retardant and antibacterial coating is applied to the surface of the adhesion-enhancing coating, and then dried and UV-cured in sequence to form a fire-retardant and antibacterial coating and obtain a fire-retardant and antibacterial diatomaceous earth decorative board.

[0061] Example 3 S1. Mix 50 parts of diatomaceous earth and 40 parts of composite flame retardant by mass to obtain a mixed powder; wherein, by mass ratio, the mixing ratio of aluminum hydroxide, ammonium polyphosphate and pentaerythritol in the composite flame retardant is 15:20:8. Add 2.5 parts of the formulated amount of γ-methacryloxypropyltrimethoxysilane to the mixed powder and stir at 6000 rpm for 30 min to obtain the pretreated powder. After mixing the pretreated powder with 25 parts of water, add 10 parts of polyvinyl aldehyde and 5 parts of vinyl acetate-ethylene copolymer emulsion according to the formula and mix evenly to obtain intermediate slurry. Add 1 part of the formulated amount of chopped glass fiber to the intermediate slurry and mix well. Then add 1.2 parts of the formulated amount of glutaraldehyde and mix well to obtain the molding slurry. S2. Mix 110 parts by weight of bisphenol F epoxy resin, 2 parts by weight of γ-(2,3-epoxypropoxy)propyltrimethoxysilane, 42 parts by weight of phenolic amine curing agent, and 30 parts by weight of propylene glycol methyl ether acetate to obtain an adhesion-enhancing coating; the manufacturer of bisphenol F epoxy resin is Zhilun New Material Technology (Xi'an) Co., Ltd., and the model is ZLF-160B; the phenolic amine curing agent is T-31 curing agent; S3. Mix 6 parts of nano-silica, 10 parts of methacryloyloxyethyl hexadecyl dimethyl ammonium chloride, 28 parts of 2-hydroxyethyl methacrylate phosphate, 20 parts of [(6-oxo-6H-dibenzo[C,E][1,2]oxophosphazenehexyl-6-yl)methyl]succinate bis(2-hydroxyethyl) ester, 80 parts of hexafunctional polyurethane acrylate resin, 5 parts of photoinitiator (a mixture of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and 1-hydroxycyclohexylphenyl ketone in a 1:1 mass ratio), and 40 parts of dipropylene glycol methyl ether evenly to obtain a fire-retardant and antibacterial coating; the hexafunctional polyurethane acrylate resin is Sartoma CN9006. S4. The molding slurry is injected into the mold, and after hot pressing and demolding, an intermediate board is obtained; the intermediate board is cured at 60°C for 45 hours to obtain the substrate layer; Wood grain decorative paper is hot-pressed onto the surface of the substrate layer using a hot press to form a decorative layer; After sanding the upper surface of the decorative layer, apply an adhesion-enhancing coating and leave it at room temperature until the adhesion-enhancing coating is surface dry to form an adhesion-enhancing coating. Fire-retardant and antibacterial coating is applied to the surface of the adhesion-enhancing coating, and then dried and UV-cured in sequence to form a fire-retardant and antibacterial coating and obtain a fire-retardant and antibacterial diatomaceous earth decorative board.

[0062] Comparative Example 1 The preparation method and raw materials of this comparative example are the same as those of Example 1. The difference is that the fireproof and antibacterial coating of this comparative example does not contain methacryloyloxyethylhexadecyldimethylammonium chloride.

[0063] Comparative Example 2 The preparation method and raw materials of this comparative example are the same as those of Example 1. The difference is that 2-hydroxyethyl methacrylate phosphate was not added to the fireproof and antibacterial coating of this comparative example.

[0064] Comparative Example 3 The preparation method and raw materials of this comparative example are the same as those of Example 1. The difference is that the fireproof and antibacterial coating of this comparative example does not contain [(6-oxo-6H-dibenzo[C,E][1,2]oxophosphoroxane-6-yl)methyl]bis(2-hydroxyethyl) succinate.

[0065] The performance of the fireproof and antibacterial diatomaceous earth decorative panels prepared in the examples and comparative examples were tested respectively, and the results are shown in Table 1 below: Table 1. Performance test results of different fire-resistant and antibacterial diatomaceous earth decorative panels in the examples and comparative examples.

[0066] As shown in Table 1, the decorative layer of the fireproof and antibacterial diatomaceous earth decorative board obtained by this technical solution is clearly visible, with good decorative effect, bending strength ≥20.5Mpa, impact strength >2.5kJ / m2, fire resistance at least A2 level, antibacterial rate against Escherichia coli >90%, and antibacterial rate against Staphylococcus aureus >90%. This is beneficial to ensure mechanical strength while not only having excellent decorative effect, but also having fireproof and antibacterial properties to meet actual use needs.

[0067] The technical principles of the present invention have been described above with reference to specific embodiments. These descriptions are merely for explaining the principles of the invention and should not be construed as limiting the scope of protection of the invention in any way. Based on this explanation, those skilled in the art can readily conceive of other specific embodiments of the invention without inventive effort, and these embodiments will all fall within the scope of protection of the present invention.

Claims

1. A fire-resistant and antibacterial diatomaceous earth decorative panel, characterized in that, It includes, from bottom to top, a substrate layer, a decorative layer, and a fire-retardant and antibacterial coating; According to the mass percentage, the raw materials of the substrate layer include 45-50 parts of diatomaceous earth, 30-43 parts of composite flame retardant, 8-10 parts of polyvinyl alcohol, 3-5 parts of vinyl acetate-ethylene copolymer emulsion, 0.8-1.2 parts of crosslinking agent, 1.5-2.5 parts of silane coupling agent, 0.5-1 parts of chopped glass fiber, and 18-28 parts of water; The composite flame retardant includes aluminum hydroxide, ammonium polyphosphate, and pentaerythritol; According to the mass fraction, the raw materials of the fireproof and antibacterial coating include 3-6 parts of nano-silica, 6-10 parts of methacryloyloxyethyl hexadecyl dimethyl ammonium chloride, 20-30 parts of 2-hydroxyethyl methacrylate phosphate, 10-20 parts of [(6-oxo-6H-dibenzo[C,E][1,2]oxophosphoroxane-6-yl)methyl]bis(2-hydroxyethyl) succinate, 80-100 parts of polyurethane acrylate resin, 3-5 parts of photoinitiator, and 20-40 parts of organic solvent.

2. The fireproof and antibacterial diatomaceous earth decorative board according to claim 1, characterized in that, According to the mass ratio, the mixing ratio of aluminum hydroxide, ammonium polyphosphate and pentaerythritol in the composite flame retardant is (10-15):(15-20):(5-8).

3. The fireproof and antibacterial diatomaceous earth decorative board according to claim 1, characterized in that, The crosslinking agent is glutaraldehyde.

4. The fireproof and antibacterial diatomaceous earth decorative board according to claim 1, characterized in that, The polyurethane acrylate resin is a hexafunctional polyurethane acrylate resin.

5. The fireproof and antibacterial diatomaceous earth decorative board according to claim 1, characterized in that, The silane coupling agent includes any one of dodecyltrimethylsilane, vinyltrimethoxysilane, and γ-methacryloxypropyltrimethoxysilane.

6. The fireproof and antibacterial diatomaceous earth decorative board according to claim 5, characterized in that, The photoinitiator comprises 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and 1-hydroxycyclohexylphenyl ketone.

7. The fireproof and antibacterial diatomaceous earth decorative board according to claim 1, characterized in that, It also includes an adhesion-enhancing coating, which is located between the decorative layer and the fire-retardant and antibacterial coating; The raw materials for the adhesion-enhancing coating, calculated by weight, include 90-110 parts of bisphenol F type epoxy resin, 2-4 parts of γ-(2,3-epoxypropoxy)propyltrimethoxysilane, 30-45 parts of phenolic amine curing agent, and 10-30 parts of propylene glycol methyl ether acetate.

8. A method for preparing a fire-resistant and antibacterial diatomaceous earth decorative panel, used to prepare the fire-resistant and antibacterial diatomaceous earth decorative panel as described in claim 7, comprising the following steps: S1. Mix the diatomaceous earth and composite flame retardant according to the formula until uniform to obtain a mixed powder; Add the prescribed amount of silane coupling agent to the mixed powder and stir at 5000-8000 rpm for 30-60 min to obtain the pretreated powder; After mixing the pretreated powder with the prescribed amount of water, add the prescribed amount of polyvinyl aldehyde and vinyl acetate-ethylene copolymer emulsion and mix evenly to obtain the intermediate slurry. Add the prescribed amount of chopped glass fiber to the intermediate slurry and mix evenly. Then add the prescribed amount of crosslinking agent and mix evenly to obtain the molding slurry. S2. After uniformly mixing the formulated amounts of bisphenol F type epoxy resin, γ-(2,3-epoxypropoxy)propyltrimethoxysilane, phenolic amine curing agent and propylene glycol methyl ether acetate, an adhesion-enhancing coating is obtained. S3. After uniformly mixing the formulated amounts of nano-silica, methacryloyloxyethyl hexadecyl dimethyl ammonium chloride, 2-hydroxyethyl methacrylate phosphate, [(6-oxo-6H-dibenzo[C,E][1,2]oxophosphoroxane-6-yl)methyl]succinate bis(2-hydroxyethyl) ester, polyurethane acrylate resin, photoinitiator and organic solvent, a fire-retardant and antibacterial coating is obtained. S4. The molding slurry is injected into the mold, and after hot pressing and demolding, an intermediate plate is obtained; the intermediate plate is cured to obtain the substrate layer; Wood grain decorative paper is hot-pressed onto the surface of the substrate layer using a hot press to form a decorative layer; After sanding the upper surface of the decorative layer, apply an adhesion-enhancing coating and leave it at room temperature until the adhesion-enhancing coating is surface dry to form an adhesion-enhancing coating. Fire-retardant and antibacterial coating is applied to the surface of the adhesion-enhancing coating, and then dried and UV-cured in sequence to form a fire-retardant and antibacterial coating and obtain a fire-retardant and antibacterial diatomaceous earth decorative board.

9. The method for preparing a fireproof and antibacterial diatomaceous earth decorative panel according to claim 8, characterized in that, In step S4, the curing temperature is 60-70℃ and the curing time is 24-48h.

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