An explosion-proof weather-resistant anti-fingerprint marble-imitating powder coating and a preparation method thereof

Abstract

The application discloses an explosion-proof weather-resistant anti-fingerprint marble-imitating powder coating and a preparation method thereof. The coating is prepared by dry mixing a main base color powder A and a texture functional powder B according to a mass ratio of (70-90):(10-30). The A component comprises polyester resin and perfluoropolyether modified polysiloxane anti-fingerprint additives; the B component adopts high-viscosity polyester resin and contains a composite filler composed of nano magnesium hydroxide, nano silicon nitride and multi-walled carbon nanotubes. The functional filler is directionally enriched in the texture area by regulating the viscosity gradient between the components. The application can improve the flame-retardant explosion-proof, static dissipation and surface protection performance of the coating while keeping high simulation texture.

Description

Technical Field

[0001] This invention belongs to the field of powder coatings, specifically relating to an explosion-proof, weather-resistant, fingerprint-resistant, marble-like powder coating and its preparation method. Background Technology

[0002] Marble-like powder coatings, as a highly efficient, environmentally friendly, and stable coating technology, have gradually become a popular surface treatment solution for industries such as explosion-proof doors and chemical plant components due to their ability to simulate the natural texture of natural stone while possessing good chemical corrosion resistance and mechanical strength. These coatings typically utilize a blend of powders of different colors and melt indices. During the curing process, the differences in rheology and surface tension gradients between the components spontaneously evolve to create layered flow marks and interwoven color effects.

[0003] However, traditional marble-look powder coatings have focused primarily on the realism of decorative textures and conventional weather resistance, with insufficient attention paid to their functional response in flammable and explosive environments. In oil and gas processing and dust-intensive production environments, the accumulation and uncontrolled release of static electricity are major hidden dangers that could lead to catastrophic accidents.

[0004] Existing marble-like coatings typically exhibit high insulation properties, with surface resistivity usually on the order of the order of magnitude, making it impossible to form electrostatic dissipation paths. Therefore, they are highly susceptible to generating electrostatic sparks when exposed to fluctuations in ambient humidity or intense friction. Furthermore, conventional resin matrices often exhibit high combustion rates and toxic smoke releases when exposed to high temperatures or open flames, lacking the necessary flame-retardant barriers and failing to meet explosion-proof rating standards.

[0005] Introducing inorganic flame retardants (such as metal hydroxides) or conductive fillers (such as carbon black, graphite, and metal oxides) can create an anchoring effect, significantly increasing the viscosity of the resin during curing. This severely hinders the diffusion and shearing between texture components, resulting in a stiff, blurry marble-like texture that loses the unique rheological layering of natural stone. Simultaneously, the fillers and matrix resin can induce micro-phase separation on the coating surface, leading to a surge in surface roughness, disordered gloss, and decreased fingerprint resistance. Summary of the Invention

[0006] To address the technical challenges of traditional marble-look powder coatings in the prior art, particularly regarding the lack of synergy between explosion-proof safety, antistatic properties, weather resistance, fingerprint resistance, and the integration of functional fillers with decorative textures, this invention provides an explosion-proof, weather-resistant, and fingerprint-resistant marble-look powder coating and its preparation method. This invention achieves this by meticulously constructing a nanoscale flame-retardant-conductive filler system and combining it with differentiated control of the melt rheological properties among multi-component powders. This results in a microstructure with functional gradient distribution within and on the surface of the coating, thereby enhancing its flame-retardant, explosion-proof, static dissipation, and surface protection properties without compromising the aesthetic appeal of the marble-look texture.

[0007] To achieve the above-mentioned objectives, the present invention provides an explosion-proof, weather-resistant, fingerprint-resistant, marble-like powder coating, which is formed by physical dry mixing of main base color powder A and texture function powder B in a mass ratio of (70-90):(10-30).

[0008] The main base color powder A is composed of the following components in parts by weight: 45-60 parts of saturated carboxylated polyester resin with an acid value of 30-35 mgKOH / g, a glass transition temperature of 58-65℃, and a melt viscosity of 3000-4500 mPa·s at 200℃; 3-5 parts of curing agent, wherein the curing agent is tris(triglycidyl) isocyanurate; 0.8-1.2 parts of leveling agent, wherein the leveling agent is an acrylate copolymer; 0.4-0.6 parts of degassing agent, wherein the degassing agent is benzoin; 15-25 parts of weather-resistant titanium dioxide, wherein the surface of the titanium dioxide is treated with aluminum and silicon inorganic coating; 1-3 parts of anti-fingerprint additive, wherein the anti-fingerprint additive is hydroxyl-terminated perfluoropolyether modified polysiloxane with a number average molecular weight of 2000-3500; and 10-20 parts of inorganic filler.

[0009] The textured functional powder B is composed of the following components in parts by weight: 35-50 parts of high-viscosity saturated carboxylated polyester resin with an acid value of 20-25 mgKOH / g, a glass transition temperature of 62-70℃, and a melt viscosity of 6000-8500 mPa·s at 200℃; 2.5-4 parts of curing agent; 15-25 parts of nano-flame retardant-conductive composite filler; 1-5 parts of pigment, used to form a texture color that is different from the main base color powder A; and 0.5-1.5 parts of charge regulator, wherein the charge regulator is a quaternary ammonium salt with long-chain alkyl groups.

[0010] In a preferred embodiment of the present invention, the nano-flame-retardant-conductive composite filler is composed of nano-magnesium hydroxide, nano-silicon nitride, and multi-walled carbon nanotubes after surface modification. The nano-magnesium hydroxide has an average particle size of 50-100 nm and its surface is coated with a 2-5 nm thick silane coupling agent layer, wherein the silane coupling agent is 3-aminopropyltriethoxysilane. The nano-silicon nitride has an average particle size of 20-40 nm. The multi-walled carbon nanotubes have a diameter of 10-20 nm, a length of 5-15 μm, and an aspect ratio greater than 500. In the nano-flame-retardant-conductive composite filler, the mass ratio of nano-magnesium hydroxide, nano-silicon nitride, and multi-walled carbon nanotubes is (10-15):(3-5):(1-2). This specific filler combination utilizes materials of different dimensions to construct a three-dimensional network within a resin matrix. One-dimensional multi-walled carbon nanotubes establish continuous electron transport channels in the textured region through a high aspect ratio, enabling rapid dissipation of static electricity; zero-dimensional nano-magnesium hydroxide and nano-silicon nitride fill the gaps in the carbon nanotube network, and exert a synergistic flame-retardant effect by releasing water of crystallization and forming a dense silicon nitride solid barrier when heated.

[0011] The anti-fingerprint additive used in the main base color powder A migrates to the coating surface through the perfluoropolyether segments at the ends of its molecular chains. During the coating curing process, due to the extremely low surface energy of the perfluoropolyether segments, they spontaneously accumulate at the interface between the coating and air, forming a hydrophobic and oleophobic layer with a thickness of 10-30 nm. This layer structure makes it difficult for fingerprint grease to wet and spread in the microscopic rough structure when it comes into contact with the coating surface, maintaining a contact angle of over 110°, thus achieving excellent anti-fingerprint and easy-to-clean effects.

[0012] In this invention, a gradient distribution of functional fillers is achieved by controlling the melt viscosity gradient between the base color powder A and the texture functional powder B. The melt viscosity of the texture functional powder B is higher than that of the base color powder A in the initial stage of curing. This results in the texture functional powder B not completely mixing with the base color powder A during the thermal leveling process, but rather being distributed in strips or patches within the base color components. Due to the melt rheological pressure difference, it forms tiny raised textures on the coating surface. Because the nano-flame-retardant-conductive composite filler is pre-dispersed in the texture functional powder B, these functional components are enriched in the raised parts of the texture and its deeper regions, forming flame-retardant preferential channels and conductive preferential channels that run through the coating thickness direction. This non-uniform distribution ensures that even with a low total filler addition, the local areas of the coating can still reach the conductivity and flame-retardant concentration thresholds, thereby maintaining the clarity of the marble-like texture while reducing the surface resistivity to 10. 6 -10 9 Ω prevents the accumulation of static charge.

[0013] The preparation method of the explosion-proof, weather-resistant, fingerprint-resistant, marble-like powder coating includes the following steps: The first step is the preparation of the main base color powder A. First, weigh out the saturated carboxylated polyester resin, curing agent, leveling agent, degassing agent, weather-resistant titanium dioxide, anti-fingerprint additive, and inorganic filler according to the formula ratio. Add these components to a high-pressure mixer and premix for 15-20 minutes at 1500-2000 rpm. During premixing, the high-speed shearing action ensures the anti-fingerprint additive is uniformly adsorbed onto the surface of the resin particles. Next, feed the premixed material into a twin-screw extruder for melt extrusion. Set the temperature in zone one of the extruder to 90-95℃, the temperature in zone two to 105-110℃, and the screw speed to 400-500 rpm. During extrusion, the strong shearing force generated by the screw ensures that the components achieve molecular-level dispersion in the molten state. Finally, cool the extruded sheet to below 30℃ using cooling rollers, and then grind it using an ACM mill. During the grinding process, the speed of the classifying wheel is adjusted to collect powder with an average particle size D50 of 30-35μm, thus obtaining the main base color powder A.

[0014] The second step is the preparation of textured functional powder B. First, surface activation treatment of the nano-flame-retardant-conductive composite filler is performed. Nano-magnesium hydroxide, nano-silicon nitride, and multi-walled carbon nanotubes are added to an anhydrous ethanol solution containing 1% by mass of 3-aminopropyltriethoxysilane and ultrasonically dispersed at 60-70℃ for 2 hours. Afterwards, the mixture is vacuum filtered, dried, and pulverized to obtain the surface-modified composite filler. Next, high-viscosity saturated carboxylated polyester resin, curing agent, pigment, charge regulator, and the modified composite filler are added to a premixer and forcibly mixed at a high speed of 2500 rpm for 25 minutes to ensure that the high aspect ratio carbon nanotubes and nanoparticles are initially deagglomerated in a dry powder state. Then, a twin-screw extruder is used for secondary dispersion extrusion. To protect the length of the carbon nanotubes from excessive shearing damage, the extruder speed is controlled at 300-350 rpm, and the extrusion section temperature is set at 115-120℃. Finally, the material flakes are cooled and ground. Powder with an average particle size D50 of 45-55 μm is collected by grading and sieving to obtain texture functional powder B. The particle size of the texture powder is designed to be larger than that of the base color powder, further enhancing its ability to construct textures on the coating surface and the enrichment density of fillers.

[0015] The third step is dry mixing and final product preparation. The prepared base color powder A and texture functional powder B are added to a dry mixer in a specific ratio and mixed at low speed (300-500 rpm) for 10-15 minutes. During the mixing process, 0.2-0.3 parts by weight of nano-silica are added as a flow aid to improve the powder's charge-carrying properties and atomization effect during spraying, ultimately yielding the finished coating.

[0016] In application, the coating described in this invention is deposited onto the substrate surface using electrostatic spraying and then baked and cured at 200°C for 15 minutes. During the curing reaction, the base color powder A and the texture functional powder B undergo a cross-linking reaction to form an integrated network structure. Due to the difference in acid value and melt viscosity of the polyester resin in the two types of powders, the texture functional powder B exhibits lower wettability during film formation, thereby maintaining clear boundaries in the base coating and simulating the natural linear or blocky patterns of marble.

[0017] The high-viscosity saturated carboxylated polyester resin selected in the textured functional powder B has a molecular weight distribution width controlled between 3.5 and 5.0. The relatively wide molecular weight distribution ensures that the component has a certain primary fluidity in the early stage of melting to ensure the initial fusion between particles, while in the later stage of curing it quickly exhibits cohesive viscosity, thereby locking the filler distribution position and preventing the texture from becoming blurred at the edges due to excessive leveling.

[0018] The dispersion of the nano-flame-retardant-conductive composite filler in textured functional powder B is precisely controlled through a two-stage extrusion process. In the first stage of extrusion, moderate shear force is used to break up the filler agglomerates; in the second stage, by optimizing the screw assembly, more distributive mixing elements are introduced instead of strong shear elements, ensuring that the carbon nanotubes form a uniform network distribution in the matrix rather than breaking or over-orienting. This deterministic processing ensures the continuity of the conductive network in three-dimensional space.

[0019] The inorganic filler in the main base color powder A is selected from one or more of ultrafine barium sulfate, talc powder, or mica powder. The ultrafine barium sulfate has a particle size distribution of 1-5 μm and mainly functions as a steric hindrance in the coating, assisting in the dispersion of titanium dioxide and adjusting the overall hardness and rheological pressure of the coating. The lamellar structure of talc powder helps improve the coating's impermeability and further enhances its weather resistance.

[0020] In the physical dry-mixing step of the finished coating, the charge properties of the base color powder A and the texture functional powder B are differentiated using a charge regulator. The texture functional powder B has a stronger positive or negative charge than the base color powder A, allowing the texture particles to be uniformly embedded into the base color powder layer at a specific frequency under the drive of the electric field during electrostatic spraying. This matching of electrical properties ensures the repeatability and engineering controllability of the distribution density and morphology of the marble-like texture during large-area spraying.

[0021] The anti-fingerprint properties described in this invention not only stem from the low surface energy of the perfluoropolyether segments but also benefit from the micro-nano-scale uneven structure formed on the surface of nano-silicon nitride. This structure macroscopically exhibits a delicate matte texture and microscopically forms support points similar to the lotus leaf effect, further reducing the actual contact area between skin oils and the coating. Thus, through the dual effects of physical structure and chemical properties, an anti-fingerprint standard is established.

[0022] Regarding temperature control in the preparation process, all heating stages are set with a precise temperature control deviation range of ±2℃ to ensure that the resin does not gel during extrusion, thereby guaranteeing a stable leveling window for the powder coating during application. The inlet air temperature of the ACM mill is controlled below 15℃ to prevent grinding heat from causing powder agglomeration, ensuring that the final powder particles have good free flowability.

[0023] The pigments in the textured functional powder B are selected from high-temperature resistant inorganic ceramic pigments, such as copper chromium black, cobalt blue, or titanium nickel yellow. These pigments have chemical stability and hiding power, do not undergo hue shift at a curing temperature of 200°C, and have good compatibility with the functional filler system, without interfering with the construction of the conductive network.

[0024] Regarding the mechanical properties of the coating, thanks to the reinforcing effect of high molecular weight polyester and nanofillers, the cured coating exhibits excellent toughness and adhesion. This ensures that the coating maintains its structural integrity even under mechanical impacts during the opening and closing of explosion-proof doors and under stress caused by temperature changes in chemical equipment, thus ensuring long-lasting protection and conductivity.

[0025] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention, through viscosity gradient control, directs the flame-retardant and conductive components to the textured area, protecting the gloss and color purity of the base color area, ensuring the vividness of the marble-like texture, and forming a crisscrossing charge discharge network and thermal barrier layer. This strategy of localized high concentration and overall low load solves the problems of coating embrittlement, surface roughness, and blurred texture caused by the addition of large amounts of fillers; 2. This invention constructs a triple barrier mechanism, which generates water vapor through the endothermic decomposition of nano-magnesium hydroxide when the coating is heated, forms a dense ceramic layer through nano-silicon nitride, and induces a carbonization layer at the microscopic level through carbon nanotubes. 3. By utilizing the percolation network formed by modified carbon nanotubes in the textured framework, static electricity accumulation caused by friction, induction, or environmental electric field is quickly eliminated, thus eliminating the risk of electrostatic sparks triggering an explosion. 4. The aluminum-silicon coated titanium dioxide enhances the coating's ability to reflect and shield against ultraviolet rays, and combined with a highly weather-resistant polyester matrix, it enhances the gloss retention rate. The gradient enrichment of perfluoropolyether-modified polysiloxane on the surface enhances the anti-fingerprint effect, making fingerprint residue on the surface easily wiped away with a dry cloth, reducing the surface friction coefficient, and enhancing the coating's scratch resistance. 5. By pretreating the nanofiller with a silane coupling agent, active amino groups that can participate in the crosslinking reaction of polyester-isocyanurate are introduced onto the surface of the inorganic filler, which enhances the interfacial shear strength between the filler and the resin matrix, so that the coating does not experience microcrack propagation or functional component detachment when subjected to severe mechanical impact or bending deformation. Detailed Implementation

[0026] This invention provides an explosion-proof, weather-resistant, fingerprint-resistant, marble-like powder coating and its preparation method. The core of this invention lies in constructing a functionally graded response system within the coating through precise material proportioning and complex process control. This achieves a high-fidelity decorative effect, long-lasting static dissipation, excellent flame retardancy and explosion protection, and surface fingerprint resistance within a single coating film, integrating multiple functions. The technical solution of this invention will be described in detail below with specific embodiments and comparative examples to ensure that those skilled in the art can fully understand and implement this invention.

[0027] Example 1: Main base color powder A: 52 parts of saturated carboxylated polyester resin, acid value 32 mg KOH / g, glass transition temperature 62℃, melt viscosity at 200℃ 3800 mPa·s; 4 parts of curing agent; 1.0 part of leveling agent; 0.5 parts of degassing agent; 20 parts of weather-resistant titanium dioxide; 2 parts of anti-fingerprint additive; 15 parts of inorganic filler; Texture Functional Powder B: 42 parts of high-viscosity saturated carboxylated polyester resin, acid value 23 mg KOH / g, glass transition temperature 66℃, melt viscosity at 200℃ 7200 mPa·s; 3 parts of curing agent; 20 parts of nano flame retardant-conductive composite filler, nano magnesium hydroxide: nano silicon nitride: multi-walled carbon nanotubes = 12:4:1; 3 parts of pigment; 1.0 part of charge regulator; The mass ratio of A to B is 80:20, and the viscosity gradient is 3400 mPa·s.

[0028] Preparation steps: S1: Preparation of main base color powder A: Weigh each component according to the formula, premix at 1800 rpm for 18 minutes; extrude at 450 rpm using a twin-screw extruder, at 92℃ in zone 1 and 108℃ in zone 2; cool the material sheet and grind it into powder using ACM (inlet air temperature 12℃), and collect the D50 32μm powder by classification. S2: Preparation of textured functional powder B: Nanocomposite filler was added to a 1% 3-aminopropyltriethoxysilane anhydrous ethanol solution, ultrasonically dispersed at 65℃ for 2 hours, filtered, dried and pulverized; mixed with other components at 2500rpm for 25 minutes according to the formula; extruded at 320rpm using a twin-screw extruder at 118℃; cooled sheet was ground into powder using ACM (inlet air temperature 13℃), and the D50 50μm powder was collected by classification. S3: Dry-mixed finished product. A and B are put into the dry mixer at a ratio of 80:20 and mixed at 400 rpm for 12 minutes. Then, 0.25 parts of nano-silica flow aid are added to obtain the finished coating.

[0029] Example 2: The mass ratio of base color powder A to texture function powder B is 70:30, and the remaining components and proportions are the same as in Example 1; Preparation steps: Same as in Example 1.

[0030] Example 3: The mass ratio of base color powder A to texture function powder B is 90:10, and the remaining components and proportions are the same as in Example 1; Preparation steps: Same as in Example 1.

[0031] Example 4: 15 parts of nano flame-retardant-conductive composite filler in textured functional powder B, with the remaining components and proportions the same as in Example 1; Preparation steps: Same as in Example 1.

[0032] Example 5: 25 parts of nano flame-retardant-conductive composite filler in textured functional powder B, with the remaining components and proportions the same as in Example 1; Preparation steps: Same as in Example 1.

[0033] Example 6: One part of anti-fingerprint additive in the base color powder A, and the remaining components and proportions are the same as in Example 1; Preparation steps: Same as in Example 1.

[0034] Example 7: 3 parts of anti-fingerprint additive in the base color powder A, and the remaining components and proportions are the same as in Example 1; Preparation steps: Same as in Example 1.

[0035] Example 8: The ratio of nano-magnesium hydroxide: nano-silicon nitride: multi-walled carbon nanotubes in the nanocomposite filler is 15:5:2, and the remaining components and proportions are the same as in Example 1; Preparation steps: Same as in Example 1.

[0036] Comparative Example 1: The main base color powder A and the texture function powder B use polyester resin with the same melt viscosity (melt viscosity of 3800 mPa·s at 200℃), and the other components are the same as in Example 1; Preparation steps: Same as in Example 1.

[0037] Comparative Example 2: In textured functional powder B, an equal amount of ultrafine barium sulfate was used to replace the nano flame-retardant-conductive composite filler, and the remaining components were the same as in Example 1; Preparation steps: Same as in Example 1.

[0038] Test method: Explosion-proof and anti-static testing: Measure the surface resistivity and charge decay time of the coating; perform electrostatic ignition testing according to standards; Flame retardant performance testing: The limiting oxygen index was determined using an oxygen index meter, and the flammability rating was determined using the vertical burning method. Anti-fingerprint test: The static contact angle of water is measured, and the difficulty of cleaning is assessed after fingerprints are manually applied, and the fingerprint residue rate is calculated.

[0039] Marble-like effect test: The realism of the texture and the clarity of the boundary are evaluated using visual scoring and a texture sharpness meter; Weather resistance test: Artificial accelerated aging for 2000 hours, measuring gloss retention rate and color difference changes; Corrosion resistance test: 1500 hours of neutral salt spray test to determine the width of unilateral corrosion spread.

[0040] Mechanical performance testing: Determine the reverse impact strength and flexibility.

[0041] The test data comparisons are shown in Table 1 and Table 2.

[0042] Table 1. Comparison of Surface Resistivity, Limiting Oxygen Index, Water Contact Angle, and Texture Realism Scores

[0043] Table 2 Comparison of 2000h gloss retention rate, reverse impact strength, and 1500h salt spray corrosion diffusion.

[0044] Examples 1 to 8 utilize the core technology principle of viscosity gradient-functional filler directional enrichment synergy. The viscosity difference between components A and B causes the functional filler to accumulate in the textured region, forming preferential channels for conductivity and flame retardancy; the anti-fingerprint additive migrates to the surface to form a hydrophobic and oleophobic layer. Comparative Example 1, lacking a viscosity gradient, suffers from uneven dispersion of the functional filler, resulting in blurred texture and loss of antistatic and explosion-proof performance; Comparative Example 2, lacking nanocomposite fillers, cannot construct a conductive and flame-retardant network, leading to a significant reduction in safety performance.

[0045] When the mass ratio of A to B is 80:20 to 70:30, the filler content is 20 to 25 parts, and the additive content is 2 to 3 parts, the safety performance and decorative effect are better. Among them, the mass ratio determines the texture coverage and functional channel density, the filler content affects the conductivity and flame retardancy efficiency, and the additive content balances the anti-fingerprint effect and coating compatibility. The three work together to ensure the overall performance of the coating.

[0046] Compared to Comparative Example 1, which has no viscosity gradient, the surface resistivity of the product in the Example 1 is reduced by more than 99%, the limiting oxygen index is increased by more than 29%, and the texture fidelity score is increased by more than 42%. Compared to Comparative Example 2, which has no composite filler, the surface resistivity is reduced by more than 99.9%, and the limiting oxygen index is increased by more than 38%, meeting the requirements for use in hazardous environments such as petrochemical plants, and exhibiting excellent fingerprint resistance and weather resistance.

[0047] In summary, this invention achieves simultaneous improvement in both decorative properties and safety through viscosity gradient regulation coupled with directional enrichment of nanocomposite fillers, with different parameter combinations. It exhibits excellent fingerprint resistance and weather resistance, solving the core pain points of traditional marble-like powder coatings. It is suitable for special industries and high-end building fields and has good potential for industrialization.

[0048] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An explosion-proof, weather-resistant, fingerprint-resistant, marble-like powder coating, characterized in that, The powder coating is physically dry-mixed from the main base color powder A and the texture function powder B at a mass ratio of (70-90):(10-30); The main base color powder A is composed of the following components in parts by mass: 45-60 parts of saturated carboxyl polyester resin; 3-5 parts of curing agent, wherein the curing agent is tris(triglycidyl)isocyanurate; 0.8-1.2 parts of leveling agent, wherein the leveling agent is an acrylate copolymer; 0.4-0.6 parts of degassing agent, wherein the degassing agent is benzoin; 15-25 parts of weather-resistant titanium dioxide, wherein the surface of the weather-resistant titanium dioxide is treated with an inorganic coating of aluminum and silicon; 1-3 parts of anti-fingerprint additive, wherein the anti-fingerprint additive is a hydroxyl-terminated perfluoropolyether modified polysiloxane; 10-20 parts of inorganic filler; The textured powder B is composed of the following components in parts by mass: 35-50 parts of high-viscosity saturated carboxylated polyester resin; 2.5-4 parts of curing agent; 15-25 parts of nano-flame retardant-conductive composite filler; 1-5 parts pigment; 0.5-1.5 parts of charge regulator, wherein the charge regulator is a quaternary ammonium salt with a long-chain alkyl group.

2. The explosion-proof, weather-resistant, fingerprint-resistant, marble-like powder coating according to claim 1, characterized in that, The saturated carboxyl polyester resin in the main base color powder A is used to construct a low-viscosity melt flow leveling bed. There is a viscosity gradient pressure difference of 2500-4500 mPa·s between its melt viscosity at 200°C and the melt viscosity of the high-viscosity saturated carboxyl polyester resin in the texture functional powder B at 200°C, so as to ensure that the texture functional powder B maintains a clear strip or patchy distribution during the curing and film formation process.

3. The explosion-proof, weather-resistant, fingerprint-resistant, marble-like powder coating according to claim 1, characterized in that, The anti-fingerprint additive migrates and accumulates on the coating surface through the perfluoropolyether segments at the ends of its molecular chain. After the powder coating is cured, a hydrophobic and oleophobic layer with a thickness of 10-30 nm is formed at the interface between the coating and the air, so that the static contact angle between the coating surface and water is maintained above 110°.

4. The explosion-proof, weather-resistant, fingerprint-resistant, marble-like powder coating according to claim 1, characterized in that, The inorganic filler in the main base color powder A is selected from one or more of ultrafine barium sulfate, talc powder, or mica powder; wherein, the ultrafine barium sulfate is used to generate a steric hindrance effect in the coating to assist in the dispersion of the weather-resistant titanium dioxide; the talc powder has a plate-like microstructure and is used to construct a physical shielding layer to improve the weather resistance and impermeability of the coating.

5. The explosion-proof, weather-resistant, fingerprint-resistant, marble-like powder coating according to claim 1, characterized in that, The high-viscosity saturated carboxylated polyester resin in the textured functional powder B has a molecular weight distribution width controlled between 3.5 and 5.

0. This wide molecular weight distribution ensures the component has primary fluidity to guarantee particle fusion in the early stage of melting, and locks the distribution position of the nano flame-retardant-conductive composite filler in the later stage of curing through high cohesive viscosity.

6. The explosion-proof, weather-resistant, fingerprint-resistant, marble-like powder coating according to claim 1, characterized in that, The nano-flame-retardant-conductive composite filler is composed of nano-magnesium hydroxide, nano-silicon nitride, and multi-walled carbon nanotubes after surface modification; wherein, the surface of the nano-magnesium hydroxide is coated with a silane coupling agent layer, and the silane coupling agent is 3-aminopropyltriethoxysilane.

7. The explosion-proof, weather-resistant, fingerprint-resistant, marble-like powder coating according to claim 6, characterized in that, In the nano-flame-retardant-conductive composite filler, the mass ratio of nano-magnesium hydroxide, nano-silicon nitride, and multi-walled carbon nanotubes is (10-15):(3-5):(1-2). The multi-walled carbon nanotubes establish a continuous electron transport percolation network in the textured region through a high aspect ratio. The nano-magnesium hydroxide and nano-silicon nitride fill the gaps in the electron transport percolation network and exert flame-retardant and explosion-proof effects by releasing crystal water upon heating and forming a solid-phase ceramic shielding layer.

8. The explosion-proof, weather-resistant, fingerprint-resistant, marble-like powder coating according to claim 1, characterized in that, The pigment in the textured functional powder B is a high-temperature resistant inorganic ceramic pigment, which is selected from one or more of copper chromium black, cobalt blue, or titanium nickel yellow, and is used to maintain hue stability and not interfere with the construction of the conductive network under the curing condition of 200°C.

9. The explosion-proof, weather-resistant, fingerprint-resistant, marble-like powder coating according to claim 1, characterized in that, After curing, the powder coating forms a single-layer coating system with a functional gradient distribution. The nano-flame-retardant-conductive composite filler is enriched in the textured protrusions formed by the textured functional powder B and in the deep region penetrating the coating thickness direction, constituting flame-retardant preferential channels and conductive preferential channels, thus stabilizing the coating surface resistivity at 10. 6 -10 9 Between Ω.

10. A method for preparing an explosion-proof, weather-resistant, fingerprint-resistant, marble-like powder coating as described in any one of claims 1-9, characterized in that, Includes the following steps: Weigh out saturated carboxylated polyester resin, curing agent, leveling agent, degassing agent, weather-resistant titanium dioxide, anti-fingerprint additive and inorganic filler according to the formula ratio, and premix evenly; feed the premix into a twin-screw extruder for melt extrusion; after cooling, grind the sheet and collect the main base color powder A through a classifying wheel; Nano-magnesium hydroxide, nano-silicon nitride, and multi-walled carbon nanotubes were added to an anhydrous ethanol solution of 1% (w / w) 3-aminopropyltriethoxysilane, ultrasonically dispersed, vacuum filtered, dried, and pulverized to obtain a surface-modified composite filler. High-viscosity saturated carboxylated polyester resin, curing agent, pigment, and charge regulator were mixed with the modified composite filler. A twin-screw extruder was used for secondary dispersion extrusion. The sheet was cooled, ground, and sieved to collect textured functional powder B. The base color powder A and texture function powder B are added into a dry mixer in a certain proportion and mixed evenly. During the mixing process, 0.2-0.3 parts by weight of nano silica are added as a flow aid to obtain the finished coating.

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