Environment-friendly ultralow-gloss pre-coated plate and preparation method thereof

Abstract

The invention relates to the technical field of precoated plate preparation, and provides an environment-friendly ultralow-gloss precoated plate and a preparation method thereof.The environment-friendly ultralow-gloss precoated plate comprises a precoated plate body, the precoated plate body is prepared from a base material, a primer layer, a composite matt layer, an antibacterial formaldehyde removal functional layer and a protective layer from bottom to top in sequence, and the 60-degree-angle glossiness of the precoated plate body is smaller than or equal to 8 GU; the formaldehyde emission is less than or equal to 0.03 mg / m < 3 >, the VOC emission is less than or equal to 50g / L, the composite matt layer comprises a composite matting agent, the composite matting agent is a compound system of nano hollow silicon dioxide and organic silicon modified polyurea microspheres, and the mass ratio of the nano hollow silicon dioxide to the organic silicon modified polyurea microspheres is 3: 1-5: 1. Through a compound extinction system of nano hollow silicon dioxide and organic silicon modified polyurea microspheres, by means of particle size complementation and structure synergistic effect, a pre-coated plate can form ultralow and stable glossiness and extremely small glossiness fluctuation amplitude only by using the addition amount of a reasonable proportion, and meanwhile, the surface of a coating forms proper roughness.

Description

Technical Field

[0001] This invention relates to the field of pre-coated panel preparation technology, specifically to an environmentally friendly ultra-low gloss pre-coated panel and its preparation method. Background Technology

[0002] Pre-coated panels, with their advantages of convenient construction and outstanding decorative properties, have been widely used in various fields such as interior and exterior wall decoration, high-end medical facilities, star-rated hotels, infant and toddler activity spaces, and furniture manufacturing. With the deepening of green building concepts and the upgrading of consumer demand, the market has placed more comprehensive demands on the performance of pre-coated panels: on the one hand, ultra-low gloss (≤10GU) surfaces can reduce indoor light pollution and provide a soft and comfortable visual experience, making them an important choice for scenarios such as medical operating rooms and office areas; on the other hand, environmental indicators (low VOC, low formaldehyde) are directly related to the health of the usage environment, and long-lasting antibacterial and formaldehyde removal functions can further adapt to the usage needs of special places. Meanwhile, the adhesion between the coating and the substrate, and product durability are also key to ensuring long-term use.

[0003] In the existing technology, the research and development of ultra-low gloss pre-coated panels has made some progress, with some products achieving breakthroughs in matting effect, environmental performance, or single function. For example, some solutions achieve low-gloss surfaces by adding matting agents, some water-based pre-coated panels reduce VOC emissions, and a few products integrate antibacterial or formaldehyde removal functions. However, from the perspective of practical application needs, the existing technology still has the problem of insufficient performance synergy: the long-term stability of the matting effect of some products needs to be improved, some environmentally friendly products cannot simultaneously achieve low gloss and functional characteristics, and the coating adhesion of some products is not consistent in complex environments. Moreover, most manufacturing processes still have room for optimization in balancing efficiency and energy consumption, failing to fully meet the comprehensive requirements of high-end scenarios for pre-coated panels to be "low-gloss stable, environmentally friendly and healthy, fully functional, durable and reliable, and highly efficient in manufacturing."

[0004] As various sectors increasingly demand higher comprehensive performance from pre-coated panels, developing an environmentally friendly pre-coated panel that simultaneously achieves stable ultra-low gloss output, excellent environmental performance, long-lasting antibacterial and formaldehyde removal functions, strong coating adhesion, and a highly efficient and low-consumption manufacturing process has become an important direction for industry development. Currently, no mature solution has been developed that comprehensively covers these requirements; therefore, the research and development and breakthroughs in related technologies are of significant practical importance for promoting the upgrading and development of the pre-coated panel industry. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides an environmentally friendly ultra-low gloss pre-coated plate and its preparation method, which solves the problems that color-coated plates cannot simultaneously achieve stable ultra-low gloss output, excellent environmental performance, long-lasting antibacterial and formaldehyde removal functions, strong coating adhesion, and efficient and low-consumption preparation process.

[0006] To achieve the above objectives, the present invention provides the following technical solution: an environmentally friendly ultra-low gloss pre-coated panel and its preparation method, comprising a pre-coated panel body, wherein the pre-coated panel body is composed of, from bottom to top, a substrate, a primer layer, a composite matte layer, an antibacterial and formaldehyde-removing functional layer, and a protective layer, wherein the pre-coated panel body has a 60° angle gloss ≤ 8 GU and a formaldehyde emission ≤ 0.03 mg / m². 3 The VOC emission is ≤50g / L. The composite matte layer contains a composite matting agent, which is a compound system of nano-hollow silica and organosilicon-modified polyurea microspheres, and the mass ratio of nano-hollow silica to organosilicon-modified polyurea microspheres is 3:1 to 5:1.

[0007] Preferably, the substrate is prepared from asbestos-free calcium silicate board, and the density of the asbestos-free calcium silicate board is 1.2-1.5 g / cm³. 3 Water absorption rate ≤3%.

[0008] Preferably, the nano-hollow silica has a particle size of 2–5 μm, a porosity of 60%–80%, and a specific surface area of ​​300–500 m². 2 / g, wherein the organosilicon-modified polyurea microspheres have a particle size of 1-3 μm, a Shore hardness of A50-A70, and a surface hydroxyl content of 0.8-1.2 mmol / g.

[0009] Preferably, in the antibacterial and formaldehyde-removing functional layer, the mass ratio of silver ion modified zeolite to amino-based graphene is 2:1 to 3:1, and the total amount of both added is 5% to 8% of the total mass of the antibacterial and formaldehyde-removing functional layer. The silver ion loading of the silver ion modified zeolite is 0.5 to 1.0 wt%, and the amino grafting rate of the amino-based graphene is 15% to 25%.

[0010] Preferably, the protective layer has a pencil hardness ≥3H, a water contact angle ≥110°, a scratch resistance ≥4N, a 24h water immersion water absorption rate ≤1%, an antibacterial rate of ≥99.9% against Escherichia coli and Staphylococcus aureus, a formaldehyde removal rate ≥92%, and an antibacterial and formaldehyde removal effect decay rate of ≤5% over 5 years.

[0011] A method for preparing an environmentally friendly ultra-low gloss pre-coated panel includes the following steps: Step 1: After the substrate is polished and dust-removed, it is treated with low-temperature plasma. Step 2: Roller-coating water-based epoxy-polyurethane composite primer and drying to form a primer layer; Step 3: Prepare a composite matte coating and spray it onto the surface of the primer layer; Step 4: Pre-curing with an excimer lamp followed by low-temperature infrared curing to form a composite matte layer; Step 5: Roller-coating antibacterial and formaldehyde-removing functional coating and curing with a UV mercury lamp to form an antibacterial and formaldehyde-removing functional layer; Step 6: Spray fluorocarbon varnish, dry at room temperature, and then cut to obtain the finished pre-coated panel body.

[0012] Preferably, in step one, the substrate pretreatment includes: first grinding the substrate to a surface roughness Ra=1.2~1.8μm and then removing dust, and then using low-temperature plasma treatment with a treatment power of 300~500W, a time of 30~60s, a distance of 5~8mm, and the working gas being an argon-oxygen mixture with a volume ratio of 4:1~6:1.

[0013] Preferably, in step two, the primer layer is a waterborne epoxy-polyurethane composite primer, which is prepared by mixing waterborne epoxy resin, waterborne polyurethane resin, γ-aminopropyltriethoxysilane, and deionized water in a mass ratio of 30:20:3:47, and is applied by roller coating with a coating amount of 40-60 g / m². 2 Dry at 50–70°C for 5–10 minutes to form a primer layer with a thickness of 20–30 μm.

[0014] Preferably, in step three, the coating for the composite matte layer is prepared by mixing a composite matting agent, aliphatic polyurethane acrylate, trimethylolpropane triacrylate, polycarboxylate dispersant, and hindered phenolic antioxidant in a mass ratio of (8-12):(40-50):(30-40):(1-3):(0.5-1.5), dispersed at 2500-3500 rpm for 40-60 min, with a coating viscosity of 25-35 mPa·s, a settling velocity ≤0.02 mm / h, and applied by spraying with a coating amount of 18-25 g / m². 2 .

[0015] Preferably, in step four, the composite curing includes: pre-curing with a 172nm excimer lamp at an energy of 300–500 mJ / cm². 2 Under nitrogen protection, the oxygen concentration is ≤80ppm, and the distance between the excimer lamp and the substrate is 10-15cm; then, low-temperature infrared curing with a wavelength of 2-5μm is used at a temperature of 40-60℃ for 8-15 minutes, with an infrared radiation intensity of 15-20kW / m². 2 A composite matte layer with a thickness of 15–20 μm is formed. In step five, the antibacterial and formaldehyde-removing functional layer is coated by roller coating with a coating amount of 10–15 g / m². 2 Curing is performed using a 365nm UV mercury lamp with an energy of 400–600 mJ / cm². 2 In step six, an antibacterial and formaldehyde-removing functional layer with a thickness of 8–12 μm is formed. This protective layer is a fluorocarbon varnish applied by spraying with a coating amount of 8–12 g / m². 2 After drying at room temperature for 24–48 hours, the product is cut to obtain the finished product.

[0016] This invention provides an environmentally friendly ultra-low gloss pre-coated panel and its preparation method. It has the following beneficial effects: 1. This invention utilizes a composite matting system of "nano-hollow silica + organosilicon-modified polyurea microspheres". By leveraging the complementary particle size and synergistic structural effects, only a reasonable proportion of the added material is needed to create an ultra-low and stable gloss level on the pre-coated panel with minimal gloss fluctuation. At the same time, the coating surface achieves a suitable roughness, presenting a soft, ultra-matte feel, which fully meets the core requirements of visual comfort in high-end scenarios.

[0017] 2. This invention adopts an environmentally friendly system of "solvent-free UV matte paint + water-based composite primer", combined with silane coupling agent to replace traditional formaldehyde-containing additives, making the product's environmental performance far superior to relevant industry standards, with extremely low VOC emissions and formaldehyde release; the functional layer achieves efficient and long-lasting antibacterial and formaldehyde removal performance through a compound design of "silver ion modified zeolite + amino-based graphene", with only slight functional decay under long-term use; combined with the combination scheme of "low-temperature plasma pretreatment + silane coupling agent modified primer", the adhesion between the coating and the substrate is greatly improved, giving the product extremely strong environmental adaptability and structural stability, with no peeling even after repeated hot and cold cycles, while also having good scratch resistance and water resistance, achieving a synergistic upgrade of environmental protection and function, taking into account both healthy use and long-term durability.

[0018] 3. This invention employs a combined process of "excimer lamp pre-curing + low-temperature infrared composite curing," which significantly shortens the total curing time and substantially reduces energy consumption compared to existing technologies. Simultaneously, it effectively avoids problems such as coating yellowing and substrate deformation that may occur in high-temperature environments. The entire process is simple and controllable, with clear and easy-to-understand operating parameters for key steps. While ensuring product quality, it further improves production efficiency and reduces production costs. Attached Figure Description

[0019] Figure 1 This is a perspective view of the present invention; Figure 2 This is a schematic diagram of the substrate structure of the present invention; Figure 3 This is a flowchart of the present invention.

[0020] Among them, 1. Pre-coated board body; 101. Substrate; 102. Primer layer; 103. Composite matte layer; 104. Antibacterial and formaldehyde-removing functional layer; 105. Protective layer. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Example: Please see the appendix Figure 1 - Appendix Figure 3 This invention provides an environmentally friendly ultra-low gloss pre-coated panel and its preparation method, comprising a pre-coated panel body 1, which is composed of a substrate 101, a primer layer 102, a composite matte layer 103, an antibacterial and formaldehyde-removing functional layer 104, and a protective layer 105 from bottom to top. The pre-coated panel body 1 has a 60° angle gloss ≤ 8 GU and a formaldehyde emission ≤ 0.03 mg / m². 3 VOC emissions ≤50g / L, the composite matte layer 103 contains a composite matting agent, which is a compound system of nano hollow silica and organosilicon modified polyurea microspheres, and the mass ratio of nano hollow silica to organosilicon modified polyurea microspheres is 3:1 to 5:1; Specifically, the substrate 101 is made of asbestos-free calcium silicate board because it combines lightweight, high strength, and low water absorption (1.2–1.5 g / cm³). 3 The density meets the lightweight requirements of building decoration panels. A water absorption rate of ≤3% prevents the coating from blistering and peeling after the substrate 101 absorbs water, making it suitable for use in humid environments. In the composite matting agent, the porous structure of nano-hollow silica enhances light scattering, while the micro-convex structure of the organosilicon-modified polyurea microspheres further disrupts the light reflection path. When the two are compounded in a 3:1 to 5:1 ratio, they can form a synergistic matting effect through complementary particle sizes. Compared to a single matting agent, it can achieve a more stable ultra-low gloss effect with a lower addition amount. Simultaneously, the Shore hardness of the organosilicon-modified polyurea microspheres (A50-A70) improves the coating toughness, preventing increased brittleness caused by excessive matting agent. In the antibacterial and formaldehyde-removing functional layer 104, silver... Ion-modified zeolite and amino-based graphene are compounded in a ratio of 2:1 to 3:1. The slow-release properties of silver ions enable rapid antibacterial action, while the high specific surface area and amino-based active sites of amino-based graphene enable formaldehyde adsorption and decomposition. The total addition of both is controlled at 5% to 8%, ensuring both functional effectiveness and without affecting the film-forming properties and adhesion of the coating. The silver ion loading of 0.5 to 1.0 wt% balances antibacterial efficiency and cost, while the amino-based grafting rate of 15% to 25% ensures the activity of formaldehyde adsorption and decomposition. The protective layer 105 uses a high-fluorine-content fluorocarbon varnish with a pencil hardness ≥3H and a water contact angle ≥110°, which gives the pre-coated board good scratch resistance and water resistance, preventing surface damage during daily use and extending its service life.

[0023] The substrate 101 is prepared from asbestos-free calcium silicate board, which has a density of 1.2–1.5 g / cm³. 3 Water absorption rate ≤3%, nano-hollow silica particle size 2-5μm, porosity 60%-80%, specific surface area 300-500m² 2 / g, the particle size of the organosilicon modified polyurea microspheres is 1-3μm, the Shore hardness is A50-A70, and the surface hydroxyl content is 0.8-1.2mmol / g. In the antibacterial and formaldehyde-removing functional layer 104, the mass ratio of silver ion modified zeolite to amino-based graphene is 2:1-3:1, and the total addition amount of the two is 5%-8% of the total mass of the antibacterial and formaldehyde-removing functional layer 104. The silver ion loading of the silver ion modified zeolite is 0.5-1.0wt%, and the amino grafting rate of the amino-based graphene is 15%-25%. The pencil hardness of the protective layer 105 is ≥3H, the water contact angle is ≥110°, the scratch resistance of the finished pre-coated board body 1 is ≥4N, the water absorption rate after 24h water immersion is ≤1%, the antibacterial rate against Escherichia coli and Staphylococcus aureus is ≥99.9%, the formaldehyde removal rate is ≥92%, and the 5-year decay rate of antibacterial and formaldehyde removal effects is ≤5%. Specifically, the selection of parameters during the preparation process is based on synergistic performance optimization: The substrate 101 is polished to a surface roughness Ra = 1.2–1.8 μm to increase the contact area between the substrate 101 and the primer layer 102, improving physical adhesion. The combination of low-temperature plasma treatment parameters and argon-oxygen mixed gas can introduce active groups onto the surface of the substrate 101, significantly increasing the surface energy to ≥45 mN / m, laying the foundation for chemical bonding. The primer layer 102 uses a waterborne epoxy-polyurethane composite system, mixed at a mass ratio of 30:20:3:47. The waterborne epoxy resin provides excellent adhesion and corrosion resistance, while the waterborne polyurethane resin enhances the coating toughness. γ-aminopropyltriethoxysilane acts as a coupling agent to achieve chemical bonding between the substrate 101 and the primer layer 102, with a concentration of 40–60 g / m³. 2 The coating amount and thickness of 20-30μm balance the protective effect and construction efficiency. Drying at 50-70℃ for 5-10 minutes ensures that the primer layer 102 fully forms a film, avoiding residual moisture from affecting the bonding of subsequent coatings. The formulation and dispersion parameters of the composite matte coating ensure uniform dispersion of each component. A viscosity of 25-35mPa・s and a settling velocity of ≤0.02mm / h ensure the stability of the coating during spraying, preventing the agglomeration of matting agents that leads to uneven gloss. 18-25g / m 2With a coating amount of 15–20 μm and a thickness of 15–20 μm, ideal matting effect and coating smoothness can be achieved. In the composite curing process, 172 nm excimer lamp pre-curing can quickly initiate coating cross-linking, nitrogen protection can avoid coating oxidation and yellowing during curing, and low-temperature infrared curing with a wavelength of 2–5 μm can complete deep curing. The low-temperature environment can also avoid substrate deformation and coating performance degradation. 15–20 kW / m 2 The infrared radiation intensity can balance curing efficiency and energy consumption; the antibacterial and formaldehyde-removing functional layer 104 (10-15 g / m²) 2 The coating amount and thickness of 8-12 μm ensure the effective content of functional components. Curing with a 365nm UV mercury lamp enables rapid film formation, preventing loss of functional components. The protective layer has a thickness of 105 (8-12 g / m²). 2 The amount of coating can form a uniform protective film, and drying at room temperature for 24-48 hours can ensure that the varnish is fully cured, guaranteeing scratch resistance, water resistance and other properties.

[0024] A method for preparing an environmentally friendly ultra-low gloss pre-coated panel includes the following steps: Step 1: After the substrate 101 is polished and dust-removed, it is treated with low-temperature plasma. Step 2: Roller-coating water-based epoxy-polyurethane composite primer and drying to form primer layer 102; Step 3: Prepare a composite matte coating and spray it onto the surface of primer layer 102; Step 4: Pre-curing with an excimer lamp followed by low-temperature infrared curing to form a composite matte layer 103; Step 5: Roller-coating antibacterial and formaldehyde-removing functional coating and curing with a UV mercury lamp to form antibacterial and formaldehyde-removing functional layer 104; Step 6: Spray fluorocarbon varnish, dry at room temperature, and then cut to obtain the finished pre-coated panel body 1.

[0025] In step one, the pretreatment of substrate 101 includes: first grinding substrate 101 to a surface roughness Ra=1.2~1.8μm and then removing dust, and then using low-temperature plasma treatment with a treatment power of 300~500W, a time of 30~60s, a distance of 5~8mm, and the working gas being an argon-oxygen mixture with a volume ratio of 4:1~6:1; In step two, the primer layer 102 is a waterborne epoxy-polyurethane composite primer, which is made by mixing waterborne epoxy resin, waterborne polyurethane resin, γ-aminopropyltriethoxysilane, and deionized water in a mass ratio of 30:20:3:47. The coating method is roller coating, and the coating amount is 40-60 g / m². 2 Dry at 50–70°C for 5–10 min to form a primer layer 102 with a thickness of 20–30 μm; In step three, the coating of the composite matte layer 103 is prepared by mixing composite matting agent, aliphatic polyurethane acrylate, trimethylolpropane triacrylate, polycarboxylate dispersant, and hindered phenolic antioxidant in a mass ratio of (8-12):(40-50):(30-40):(1-3):(0.5-1.5), and dispersed at 2500-3500 rpm for 40-60 min. The coating viscosity is 25-35 mPa·s, the settling velocity is ≤0.02 mm / h, the coating method is spraying, and the coating amount is 18-25 g / m². 2 ; Step four, the composite curing process includes: first, pre-curing with a 172nm excimer lamp at an energy of 300–500 mJ / cm². 2 Under nitrogen protection, the oxygen concentration is ≤80ppm, and the distance between the excimer lamp and the substrate 101 is 10-15cm; then, low-temperature infrared curing with a wavelength of 2-5μm is used, at a temperature of 40-60℃ for 8-15 minutes, with an infrared radiation intensity of 15-20kW / m². 2 A composite matte layer 103 with a thickness of 15–20 μm is formed; In step five, the antibacterial and formaldehyde-removing functional layer 104 is coated by roller coating, with a coating amount of 10-15 g / m². 2 Curing is performed using a 365nm UV mercury lamp with an energy of 400–600 mJ / cm². 2 This forms an antibacterial and formaldehyde-removing functional layer 104 with a thickness of 8–12 μm; In step six, the protective layer 105 is a fluorocarbon varnish, applied by spraying, with a coating amount of 8–12 g / m². 2 After drying at room temperature for 24–48 hours, the product is cut to obtain the finished product.

[0026] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An environmentally friendly, ultra-low gloss pre-coated panel, characterized in that, The pre-coated panel body (1) is composed of a substrate (101), a primer layer (102), a composite matte layer (103), an antibacterial and formaldehyde-removing functional layer (104), and a protective layer (105) from bottom to top. The pre-coated panel body (1) has a 60° angle gloss ≤ 8 GU and a formaldehyde release ≤ 0.03 mg / m³. 3 VOC emissions ≤50g / L, the composite matte layer (103) contains a composite matting agent, which is a compound system of nano-hollow silica and organosilicon-modified polyurea microspheres, and the mass ratio of nano-hollow silica to organosilicon-modified polyurea microspheres is 3:1 to 5:

1.

2. The environmentally friendly ultra-low gloss pre-coated panel according to claim 1, characterized in that, The substrate (101) is prepared from asbestos-free calcium silicate board, the density of which is 1.2–1.5 g / cm³. 3 Water absorption rate ≤3%.

3. The environmentally friendly ultra-low gloss pre-coated panel according to claim 1, characterized in that, The nano-hollow silica has a particle size of 2–5 μm, a porosity of 60%–80%, and a specific surface area of ​​300–500 m². 2 / g, wherein the organosilicon-modified polyurea microspheres have a particle size of 1-3 μm, a Shore hardness of A50-A70, and a surface hydroxyl content of 0.8-1.2 mmol / g.

4. The environmentally friendly ultra-low gloss pre-coated panel according to claim 1, characterized in that, In the antibacterial and formaldehyde-removing functional layer (104), the mass ratio of silver ion modified zeolite to amino-based graphene is 2:1 to 3:1, and the total amount of both added is 5% to 8% of the total mass of the antibacterial and formaldehyde-removing functional layer (104). The silver ion loading of the silver ion modified zeolite is 0.5 to 1.0 wt%, and the amino grafting rate of the amino-based graphene is 15% to 25%.

5. The environmentally friendly ultra-low gloss pre-coated panel according to claim 1, characterized in that, The protective layer (105) has a pencil hardness ≥3H and a water contact angle ≥110°. The pre-coated board body (1) has a scratch resistance ≥4N, a water absorption rate ≤1% after 24 hours of water immersion, an antibacterial rate ≥99.9% against Escherichia coli and Staphylococcus aureus, a formaldehyde removal rate ≥92%, and an antibacterial and formaldehyde removal effect decay rate ≤5% over 5 years.

6. A method for preparing an environmentally friendly ultra-low gloss pre-coated panel, using an environmentally friendly ultra-low gloss pre-coated panel as described in any one of claims 1-5, characterized in that, Includes the following steps: Step 1: After the substrate (101) is polished and dust-removed, it is treated with low-temperature plasma. Step 2: Roller-coating water-based epoxy-polyurethane composite primer and drying to form primer layer (102). Step 3: Prepare a composite matte coating and spray it onto the surface of the primer layer (102); Step 4: Pre-curing with an excimer lamp followed by low-temperature infrared curing to form a composite matte layer (103). Step 5: Roller-coating antibacterial and formaldehyde-removing functional coating and curing with UV mercury lamp to form an antibacterial and formaldehyde-removing functional layer (104). Step 6: Spray fluorocarbon varnish, dry at room temperature, and then cut to obtain the finished pre-coated panel body (1).

7. The method for preparing an environmentally friendly ultra-low gloss pre-coated panel according to claim 6, characterized in that, In step one, the pretreatment of the substrate (101) includes: first grinding the substrate (101) to a surface roughness Ra=1.2~1.8μm and then removing dust, and then using low-temperature plasma treatment with a treatment power of 300~500W, a time of 30~60s, a distance of 5~8mm, and the working gas being an argon-oxygen mixture with a volume ratio of 4:1~6:

1.

8. The method for preparing an environmentally friendly ultra-low gloss pre-coated panel according to claim 6, characterized in that, In step two, the primer layer (102) is a water-based epoxy-polyurethane composite primer, which is made by mixing water-based epoxy resin, water-based polyurethane resin, γ-aminopropyltriethoxysilane, and deionized water in a mass ratio of 30:20:3:

47. The coating method is roller coating, and the coating amount is 40-60 g / m². 2 Dry at 50–70°C for 5–10 min to form a primer layer (102) with a thickness of 20–30 μm.

9. The method for preparing an environmentally friendly ultra-low gloss pre-coated panel according to claim 6, characterized in that, In step three, the coating of the composite matte layer (103) is prepared by mixing composite matting agent, aliphatic polyurethane acrylate, trimethylolpropane triacrylate, polycarboxylate dispersant, and hindered phenolic antioxidant in a mass ratio of (8-12):(40-50):(30-40):(1-3):(0.5-1.5), and dispersed at 2500-3500 rpm for 40-60 min. The coating viscosity is 25-35 mPa·s, the settling velocity is ≤0.02 mm / h, the coating method is spraying, and the coating amount is 18-25 g / m. 2 .

10. The method for preparing an environmentally friendly ultra-low gloss pre-coated panel according to claim 6, characterized in that, Step four, the composite curing process includes: first, pre-curing with a 172nm excimer lamp at an energy of 300–500 mJ / cm². 2 Nitrogen protection with an oxygen concentration ≤80ppm, and the distance between the excimer lamp and the substrate (101) is 10-15cm; then low-temperature infrared curing with a wavelength of 2-5μm is used, at a temperature of 40-60℃ for 8-15min, with an infrared radiation intensity of 15-20kW / m. 2 A composite matte layer (103) with a thickness of 15-20 μm is formed. In step five, the antibacterial and formaldehyde-removing functional layer (104) is coated by roller coating with a coating amount of 10-15 g / m. 2 Curing is performed using a 365nm UV mercury lamp with an energy of 400–600 mJ / cm². 2 A protective layer (104) with a thickness of 8-12 μm is formed. In step six, the protective layer (105) is a fluorocarbon varnish, applied by spraying, with a coating amount of 8-12 g / m². 2 After drying at room temperature for 24–48 hours, the product is cut to obtain the finished product.

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