Aluminum profile powder coating and preparation method thereof

Abstract

The application discloses an aluminum profile spraying powder coating and a preparation method thereof, and belongs to the technical field of paint. The application introduces modified resin, so that the coating has excellent weather resistance, and adds specific proportion of proto-catechuic acid, 2-(4-thiazolyl) benzimidazole and 8-hydroxyquinoline as an antibacterial agent, and chemically bonds the antibacterial agent to the resin base material, so that efficient, long-lasting and broad-spectrum antibacterial effect is realized, and more significant antibacterial purpose is realized, and the problems of easy migration and easy failure of the surface spraying antibacterial agent are effectively solved. The application optimizes the overall formula, and the components interact with each other, so that the coating has excellent surface flatness and apparent quality, and the defects of pinholes and orange peel commonly existing in traditional coatings are avoided; the overall antibacterial and long-lasting antibacterial properties are significant, and the application is particularly suitable for buildings, medical treatment and household aluminum profiles with high sanitary requirements.

Description

Technical Field

[0001] This invention relates to the field of powder coating technology, and more specifically, to a powder coating for aluminum profiles and its preparation method. Background Technology

[0002] Aluminum profiles are widely used in building doors and windows, curtain walls, transportation, electronics, and home decoration due to their lightweight, high strength, ease of processing and forming, and excellent corrosion resistance. To improve the decorative properties, weather resistance, corrosion resistance, and mechanical properties of aluminum profiles, surface coating is usually required. Powder coating, as an advanced surface treatment technology, has significant advantages such as solvent-free evaporation, high utilization rate, excellent coating performance, and environmental friendliness, and has become one of the mainstream processes for aluminum profile surface treatment.

[0003] Currently, the most commonly used powder coatings for aluminum profiles on the market are epoxy resin, polyester resin, and epoxy-polyester hybrid types. However, these traditional powder coatings still have the following problems during application: In environments with large temperature variations or high humidity, the coating on the aluminum substrate surface suffers from insufficient adhesion, affecting the long-term service life of the product. For outdoor aluminum profiles (such as building exterior walls), powder coatings are required to have excellent weather resistance, but conventional polyester powder coatings may experience loss of gloss, yellowing, and color fading after prolonged exposure to sunlight, making it difficult to fully meet the requirements of high-end buildings for lasting aesthetics. With the diversification of market demands, more additional functional requirements are being placed on powder coatings, but traditional powder coatings have relatively poor overall and long-lasting antibacterial properties and still need improvement. Summary of the Invention

[0004] In view of this, in order to solve one of the above-mentioned technical problems, the present invention provides an aluminum profile powder coating and its preparation method, the specific technical solution of which is as follows:

[0005] A powder coating for aluminum profiles, comprising the following raw materials in parts by weight: 80-100 parts modified resin base, 10-20 parts modified filler, 0.5-3 parts antioxidant, 1-2 parts film-forming aid, 3-7 parts curing agent, 0.1-0.7 parts curing accelerator, 1-3 parts leveling agent, 0.1-1 part brightener, 0.3-0.5 parts degassing agent, and 0.1-1 part pigment;

[0006] The modified resin base material is prepared by adding bisphenol A epoxy resin, fluorocarbon resin, glycidyl methacrylate, antibacterial agent and catalyst into a reaction vessel, heating to 85℃~100℃ in an inert gas atmosphere, and stirring at 50r / min~100r / min for 1h~3h, then adding sebacic acid, heating to 120℃~130℃, and continuing to stir for 1h~3h to obtain the modified resin base material.

[0007] Furthermore, the antibacterial agent is obtained by mixing protocatechuic acid, 2-(4-thiazolyl)benzimidazole and 8-hydroxyquinoline in a mass ratio of (1~5):(1~3):(2~5).

[0008] Further, by weight, the ratio of the bisphenol A type epoxy resin, fluorocarbon resin, glycidyl methacrylate, antibacterial agent, catalyst and sebacic acid is (8~10):(1~3):(1~2):(0.5~5):(0.1~0.5):(1~5).

[0009] Furthermore, the catalyst is at least one of monobutyltin oxide and p-toluenesulfonic acid.

[0010] Further, the modified filler is prepared by dispersing silica powder in anhydrous ethanol, stirring at 55℃~65℃ for 20min~30min, centrifuging, washing, vacuum drying, adding to a silane coupling agent alcohol solution, ultrasonically dispersing, stirring at 60℃~70℃ for 30min~60min, and then centrifuging, washing, vacuum drying and grinding.

[0011] Further, the antioxidant is at least one of antioxidant 1076, antioxidant 1010, antioxidant 1098, antioxidant 168, antioxidant 626 and antioxidant TP80.

[0012] Furthermore, the film-forming aid is at least one of propylene glycol, propylene glycol butyl ether, dodecyl alcohol ester, and benzyl alcohol.

[0013] Furthermore, the curing agent is at least one of triglycidyl isocyanurate, β-hydroxyalkylamide, and isophorone diamine.

[0014] Furthermore, the curing accelerator is at least one of methylimidazole and triethylphenylphosphine bromide.

[0015] In addition, the present invention also provides a method for preparing powder coating for aluminum profiles, the preparation method comprising the following steps:

[0016] S1. Add the modified resin base, modified filler, antioxidant, film-forming aid, curing agent, curing accelerator, leveling agent, gloss agent, degassing agent and pigment to the mixing tank, mix evenly to obtain a mixture;

[0017] S2. The mixture is added to a twin-screw extruder and fully melted and mixed to form a molten material;

[0018] S3. The molten material is cooled by a cooling press to solidify it, then crushed and sieved to obtain aluminum profile powder coating.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. This invention introduces a modified resin, specifically a compound of bisphenol A epoxy resin and fluorocarbon resin. The fluorocarbon resin itself possesses excellent UV resistance, which, combined with the strong adhesion and mechanical strength of the bisphenol A epoxy resin, results in a coating with superior weather resistance and adhesion, thus extending the service life of aluminum profiles in harsh outdoor environments. Furthermore, the addition of a specific ratio of protocatechuic acid, 2-(4-thiazolyl)benzimidazole, and 8-hydroxyquinoline as an antibacterial agent, chemically bonded to the resin matrix, achieves a highly efficient, long-lasting, and broad-spectrum antibacterial effect, effectively solving the problems of easy migration and rapid failure of surface-sprayed antibacterial agents. The combination of these three different components as an antibacterial agent provides broad-spectrum bactericidal activity, while 2-(4-thiazolyl)benzimidazole is effective against molds. Combined with the synergistic effect of 8-hydroxyquinoline, it blocks the respiratory chain and metabolic pathways, achieving a more significant antibacterial effect from different angles.

[0021] 2. This invention mixes modified fillers with a resin matrix, which can form stronger chemical bonds and interfacial bonding forces, effectively reduce stress concentration, achieve effective molecular bonding and dispersion, improve the hardness of the coating and its adhesion to the aluminum substrate, and avoid the problems of poor compatibility and uneven performance caused by direct blending.

[0022] 3. By optimizing the overall formula, the interaction between the components in this invention can achieve excellent leveling properties, resulting in coatings with excellent surface smoothness and appearance quality. This avoids the defects of pinholes and orange peel that are common in traditional coatings, and the significant and long-lasting antibacterial properties make it suitable for aluminum profiles in buildings, medical facilities, and homes where hygiene requirements are high.

[0023] 4. The powder coating of the present invention is solvent-free and has extremely low volatile organic compound emissions, making it an environmentally friendly coating material. Furthermore, the overall process is simple, highly operable, and has excellent application value. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to its embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the scope of protection of the invention.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0026] An embodiment of the present invention provides an aluminum profile powder coating, wherein the aluminum profile powder coating comprises the following raw materials in parts by weight: 80-100 parts of modified resin base, 10-20 parts of modified filler, 0.5-3 parts of antioxidant, 1-2 parts of film-forming aid, 3-7 parts of curing agent, 0.1-0.7 parts of curing accelerator, 1-3 parts of leveling agent, 0.1-1 parts of brightener, 0.3-0.5 parts of degassing agent, and 0.1-1 parts of pigment;

[0027] The modified resin base material is prepared by adding bisphenol A epoxy resin, fluorocarbon resin, glycidyl methacrylate, antibacterial agent and catalyst into a reaction vessel, heating to 85℃~100℃ in an inert gas atmosphere, and stirring at 50r / min~100r / min for 1h~3h, then adding sebacic acid, heating to 120℃~130℃, and continuing to stir for 1h~3h to obtain the modified resin base material.

[0028] In one embodiment, the antibacterial agent is obtained by mixing protocatechuic acid, 2-(4-thiazolyl)benzimidazole and 8-hydroxyquinoline in a mass ratio of (1~5):(1~3):(2~5).

[0029] In one embodiment, the ratio of the bisphenol A type epoxy resin, fluorocarbon resin, glycidyl methacrylate, antibacterial agent, catalyst and sebacic acid by weight is (8~10):(1~3):(1~2):(0.5~5):(0.1~0.5):(1~5).

[0030] In one embodiment, the catalyst is at least one of monobutyltin oxide and p-toluenesulfonic acid.

[0031] In one embodiment, the modified filler is prepared by dispersing silica micropowder in anhydrous ethanol, stirring at 55°C to 65°C for 20 to 30 minutes, centrifuging, washing, vacuum drying, adding to a silane coupling agent alcohol solution, ultrasonically dispersing, stirring at 60°C to 70°C for 30 to 60 minutes, and then centrifuging, washing, vacuum drying, and grinding.

[0032] In one embodiment, the silane coupling agent alcohol solution is obtained by mixing a silane coupling agent, ethanol and water in a volume ratio of (1~5):(3~5):(3~5).

[0033] In one embodiment, the silane coupling agent is at least one of methyltrimethoxysilane, dimethyldimethoxysilane, vinyltrimethoxysilane, and vinyltriethoxysilane.

[0034] In one embodiment, the antioxidant is at least one of antioxidant 1076, antioxidant 1010, antioxidant 1098, antioxidant 168, antioxidant 626, and antioxidant TP80.

[0035] In one embodiment, the film-forming aid is at least one of propylene glycol, propylene glycol butyl ether, dodecyl alcohol ester, and benzyl alcohol.

[0036] In one embodiment, the curing agent is at least one of triglycidyl isocyanurate, β-hydroxyalkylamide, and isophorone diamine.

[0037] In one embodiment, the curing accelerator is at least one of methylimidazole and triethylphenylphosphine bromide.

[0038] In one embodiment, the leveling agent is at least one of polyacrylate leveling agent, silicone acrylate leveling agent, and polysiloxane leveling agent.

[0039] In one embodiment, the brightener is a copolymer of butyl acrylate, butyl acrylate and methyl methacrylate.

[0040] In one embodiment, the degassing agent is at least one of benzoin and micronized wax.

[0041] In addition, the present invention also provides a method for preparing powder coating for aluminum profiles, the preparation method comprising the following steps:

[0042] S1. Add the modified resin base, modified filler, antioxidant, film-forming aid, curing agent, curing accelerator, leveling agent, gloss agent, degassing agent and pigment to the mixing tank, mix evenly to obtain a mixture;

[0043] S2. The mixture is added to a twin-screw extruder and fully melted and mixed to form a molten material;

[0044] S3. The molten material is cooled by a cooling press to solidify it, then crushed and sieved to obtain aluminum profile powder coating.

[0045] In one embodiment, in step S1, the mixture is processed at a rotation speed of 1000 r / min to 5000 r / min for 10 min to 30 min.

[0046] In one embodiment, in step S2, the temperature of the twin-screw extruder is 80℃~95℃ in zone one, 100℃~110℃ in zone two, 110℃~120℃ in zone three, 120℃~130℃ in zone four, and 130℃~150℃ in zone five.

[0047] In one embodiment, the sieving is performed through a 100-120 mesh sieve.

[0048] The implementation schemes of the present invention will now be described in detail with reference to specific embodiments.

[0049] Example 1:

[0050] A method for preparing powder coating for aluminum profiles includes the following steps:

[0051] S1. By weight, add 100 parts of modified resin base, 15 parts of modified filler, 2 parts of antioxidant 1076, 1 part of propylene glycol, 3 parts of triglycidyl isocyanurate, 0.3 parts of methylimidazole, 2 parts of polyacrylate leveling agent, 0.2 parts of butyl acrylate, 0.3 parts of benzoin and 1 part of pigment to a mixing tank, and mix at 1000 r / min for 20 min to obtain a mixture;

[0052] The modified resin base material is prepared by adding 8 parts by weight of bisphenol A epoxy resin, 2 parts of fluorocarbon resin, 1 part of glycidyl methacrylate, 0.5 parts of antibacterial agent and 0.3 parts of monobutyltin oxide into a reaction vessel, heating to 85°C in an inert gas atmosphere, and stirring at 100 r / min for 1 h, then adding 2 parts of sebacic acid, heating to 120°C, and continuing to stir for 1 h to obtain the modified resin base material.

[0053] The antibacterial agent is obtained by mixing protocatechuic acid, 2-(4-thiazolyl)benzimidazole and 8-hydroxyquinoline in a mass ratio of 3:2:5;

[0054] The modified filler is prepared by dispersing 7 parts by weight of silica powder in 15 parts by weight of anhydrous ethanol, stirring at 65°C for 20 min, centrifuging, washing, vacuum drying, adding silane coupling agent alcohol solution (obtained by mixing dimethyldimethoxysilane, ethanol and water in a volume ratio of 3:4:3), ultrasonically dispersing, stirring at 70°C for 35 min, centrifuging, washing, vacuum drying and grinding.

[0055] S2. Add the mixture to a twin-screw extruder, and set the temperature of the twin-screw extruder to 90°C in zone 1, 105°C in zone 2, 110°C in zone 3, 120°C in zone 4, and 135°C in zone 5 to fully melt and mix to form a molten material.

[0056] S3. The molten material is cooled by a cooling press to solidify it, then crushed and passed through a 120-mesh sieve to obtain aluminum profile powder coating.

[0057] Example 2:

[0058] A method for preparing powder coating for aluminum profiles includes the following steps:

[0059] S1. By weight, add 100 parts of modified resin base, 16 parts of modified filler, 2 parts of antioxidant 1076, 1 part of propylene glycol, 4 parts of triglycidyl isocyanurate, 0.4 parts of methylimidazole, 2 parts of polyacrylate leveling agent, 0.3 parts of butyl acrylate, 0.4 parts of benzoin and 1 part of pigment to a mixing tank, and mix at 1000 r / min for 20 min to obtain a mixture;

[0060] The modified resin base material is prepared by adding 9 parts by weight of bisphenol A epoxy resin, 1 part of fluorocarbon resin, 1 part of glycidyl methacrylate, 0.5 parts of antibacterial agent and 0.4 parts of monobutyltin oxide into a reaction vessel, heating to 85°C in an inert gas atmosphere, and stirring at 100 r / min for 1 h, then adding 2 parts of sebacic acid, heating to 120°C, and continuing to stir for 1 h to obtain the modified resin base material.

[0061] The antibacterial agent is obtained by mixing protocatechuic acid, 2-(4-thiazolyl)benzimidazole and 8-hydroxyquinoline in a mass ratio of 3:3:4.

[0062] The modified filler is prepared by dispersing 7 parts by weight of silica powder in 15 parts by weight of anhydrous ethanol, stirring at 65°C for 20 min, centrifuging, washing, vacuum drying, adding silane coupling agent alcohol solution (obtained by mixing dimethyldimethoxysilane, ethanol and water in a volume ratio of 3:4:3), ultrasonically dispersing, stirring at 70°C for 35 min, centrifuging, washing, vacuum drying and grinding.

[0063] S2. Add the mixture to a twin-screw extruder, and set the temperature of the twin-screw extruder to 90°C in zone 1, 105°C in zone 2, 110°C in zone 3, 120°C in zone 4, and 135°C in zone 5 to fully melt and mix to form a molten material.

[0064] S3. The molten material is cooled by a cooling press to solidify it, then crushed and passed through a 120-mesh sieve to obtain aluminum profile powder coating.

[0065] Example 3:

[0066] A method for preparing powder coating for aluminum profiles includes the following steps:

[0067] S1. By weight, 100 parts of modified resin base, 17 parts of modified filler, 3 parts of antioxidant 1076, 2 parts of propylene glycol, 4 parts of triglycidyl isocyanurate, 0.5 parts of methylimidazole, 3 parts of polyacrylate leveling agent, 0.5 parts of butyl acrylate, 0.5 parts of benzoin and 1 part of pigment are added to a mixing tank and mixed at 1000 r / min for 20 min to obtain a mixture.

[0068] The modified resin base material is prepared by adding 8 parts by weight of bisphenol A epoxy resin, 2 parts of fluorocarbon resin, 1 part of glycidyl methacrylate, 0.5 parts of antibacterial agent and 0.3 parts of monobutyltin oxide into a reaction vessel, heating to 85°C in an inert gas atmosphere, and stirring at 100 r / min for 1 h, then adding 2 parts of sebacic acid, heating to 120°C, and continuing to stir for 1 h to obtain the modified resin base material.

[0069] The antibacterial agent is obtained by mixing protocatechuic acid, 2-(4-thiazolyl)benzimidazole and 8-hydroxyquinoline in a mass ratio of 4:3:3.

[0070] The modified filler is prepared by dispersing 7 parts by weight of silica powder in 15 parts by weight of anhydrous ethanol, stirring at 65°C for 20 min, centrifuging, washing, vacuum drying, adding silane coupling agent alcohol solution (obtained by mixing dimethyldimethoxysilane, ethanol and water in a volume ratio of 3:4:3), ultrasonically dispersing, stirring at 70°C for 35 min, centrifuging, washing, vacuum drying and grinding.

[0071] S2. Add the mixture to a twin-screw extruder, and set the temperature of the twin-screw extruder to 90°C in zone 1, 105°C in zone 2, 110°C in zone 3, 120°C in zone 4, and 135°C in zone 5 to fully melt and mix to form a molten material.

[0072] S3. The molten material is cooled by a cooling press to solidify it, then crushed and passed through a 120-mesh sieve to obtain aluminum profile powder coating.

[0073] Comparative Example 1:

[0074] The difference between Comparative Example 1 and Example 3 is that no fluorocarbon resin was added in the preparation method of the modified resin base material of Comparative Example 1, while the rest is the same as Example 3.

[0075] Comparative Example 2:

[0076] The difference between Comparative Example 2 and Example 3 is that the antibacterial agent in the preparation method of the modified resin base material in Comparative Example 2 is a single protocatechuic acid, while the rest is the same as in Example 3.

[0077] Comparative Example 3:

[0078] The difference between Comparative Example 3 and Example 3 is that the antibacterial agent in the preparation method of the modified resin base material in Comparative Example 3 is a single 2-(4-thiazolyl)benzimidazole, while the rest is the same as in Example 3.

[0079] Comparative Example 4:

[0080] The difference between Comparative Example 4 and Example 3 is that the antibacterial agent in the preparation method of the modified resin base material in Comparative Example 4 is a single 8-hydroxyquinoline, while the rest is the same as in Example 3.

[0081] Comparative Example 5:

[0082] The difference between Comparative Example 5 and Example 3 is that the antibacterial agent was directly added in Comparative Example 5, while the rest was the same as in Example 3.

[0083] That is, step S1 in Comparative Example 5 is as follows: S1. By weight, 100 parts of modified resin base, 17 parts of modified filler, 3 parts of antioxidant 1076, 0.5 parts of antibacterial agent, 2 parts of propylene glycol, 4 parts of triglycidyl isocyanurate, 0.5 parts of methylimidazole, 3 parts of polyacrylate leveling agent, 0.5 parts of butyl acrylate, 0.5 parts of benzoin and 1 part of pigment are added to a mixing tank and mixed at a speed of 1000 r / min for 20 min to obtain a mixture.

[0084] Comparative Example 6:

[0085] The difference between Comparative Example 6 and Example 3 is that the silicon powder added in Comparative Example 6 was not modified, but otherwise it was the same as Example 3.

[0086] The powder coating samples prepared in Examples 1-3 and Comparative Examples 1-6 were respectively coated onto 0.8 mm thick rust-removed and oil-removed aluminum profiles by electrostatic spraying, forming a coating thickness of 80 μm. Performance tests were then conducted. The appearance of the coatings was observed and recorded by a person skilled in the art, with the use of magnifying glasses or other auxiliary tools when necessary. Adhesion test: GB / T9286-2021; Weather resistance test: GB / T 1865-2009; Antibacterial performance: GB / T21866-2008. The coating performance is shown in Table 1.

[0087] Table 1: Coating Performance

[0088]

[0089] Analysis of the data in Table 1 shows that, after component optimization, the powder coating obtained in this invention exhibits excellent adhesion between the coating and the aluminum profile. Furthermore, the compounding of bisphenol A epoxy resin and two parts of fluorocarbon resin not only ensures coating adhesion but also helps improve the coating's weather resistance. The addition of the compounded antibacterial agent gives the coating significant antibacterial properties. Chemically bonding the antibacterial agent with the modified resin base before application helps improve the durability of the antibacterial effect. Compared with Example 3, Comparative Example 1 did not add fluorocarbon resin, and its adhesion and gloss retention were not as good as those of Example 3. This indicates that adding an appropriate amount of fluorocarbon resin can enhance the compatibility and bonding force between the resin system and the substrate, and effectively improve the weather resistance of the coating. Comparative Examples 2 to 4 all used a single antibacterial agent, resulting in antibacterial performance that was not as good as that of Example 3. No single antibacterial agent can achieve the broad-spectrum, high-efficiency, and long-lasting balanced effect of the compound system. This indicates that using protocatechuic acid, 2-(4-thiazolyl)benzimidazole and 8-hydroxyquinoline as a compound antibacterial agent can achieve multi-target, full-coverage attack on bacteria and fungi, achieve synergistic effect, and significantly increase the antibacterial performance of the coating system. In Comparative Example 5, the antibacterial agent was added directly. The antibacterial agent was dispersed in the coating in the form of small molecules and could quickly migrate to the surface to exert its effect in the early stage. However, with the passage of time and use, unbonded small molecules will migrate, leading to a decline in antibacterial performance and a decrease in antibacterial durability compared to Example 3. This indicates that chemical bonding and cross-linking of the antibacterial agent can achieve significant and durable antibacterial properties. In Comparative Example 6, the silica powder was not modified. Silica powder without silane coupling agent modification has poor compatibility with the resin matrix and exhibits a significant inorganic-organic interface. Under stress or environmental changes, it is prone to becoming stress concentration points and weak links, leading to a decrease in the adhesion between the coating and the substrate, and may even cause early cracking. This indicates that surface modification of silica powder plays a positive role in improving coating adhesion, and modified silica powder results in better overall compatibility in the powder coating. The excellent coating performance also has a positive impact on antibacterial performance.

[0090] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0091] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A powder coating for aluminum profiles, characterized in that, The aluminum profile powder coating comprises the following raw materials in parts by weight: 80-100 parts modified resin base, 10-20 parts modified filler, 0.5-3 parts antioxidant, 1-2 parts film-forming aid, 3-7 parts curing agent, 0.1-0.7 parts curing accelerator, 1-3 parts leveling agent, 0.1-1 parts brightener, 0.3-0.5 parts degassing agent, and 0.1-1 parts pigment; The modified resin base material is prepared by adding bisphenol A type epoxy resin, fluorocarbon resin, glycidyl methacrylate, antibacterial agent and catalyst into a reaction vessel, heating to 85℃~100℃ in an inert gas atmosphere, and stirring at 50r / min~100r / min for 1h~3h, then adding sebacic acid, heating to 120℃~130℃, and continuing to stir for 1h~3h to obtain the modified resin base material. By weight, the ratio of the bisphenol A type epoxy resin, fluorocarbon resin, glycidyl methacrylate, antibacterial agent, catalyst and sebacic acid is (8~10):(1~3):(1~2):(0.5~5):(0.1~0.5):(1~5). The antibacterial agent is obtained by mixing protocatechuic acid, 2-(4-thiazolyl)benzimidazole and 8-hydroxyquinoline in a mass ratio of (1~5):(1~3):(2~5); The catalyst is at least one of monobutyltin oxide and p-toluenesulfonic acid; The modified filler is prepared by dispersing silica powder in anhydrous ethanol, stirring at 55℃~65℃ for 20min~30min, centrifuging, washing, vacuum drying, adding silane coupling agent alcohol solution, ultrasonically dispersing, stirring at 60℃~70℃ for 30min~60min, and then centrifuging, washing, vacuum drying and grinding.

2. The aluminum profile powder coating according to claim 1, characterized in that, The antioxidant is at least one of antioxidant 1076, antioxidant 1010, antioxidant 1098, antioxidant 168, antioxidant 626, and antioxidant TP80.

3. The aluminum profile powder coating according to claim 1, characterized in that, The film-forming aid is at least one of propylene glycol, propylene glycol butyl ether, dodecyl alcohol ester, and benzyl alcohol.

4. The aluminum profile powder coating according to claim 1, characterized in that, The curing agent is at least one of triglycidyl isocyanurate, β-hydroxyalkylamide, and isophorone diamine.

5. The aluminum profile powder coating according to claim 1, characterized in that, The curing accelerator is at least one of methylimidazole and triethylphenylphosphine bromide.

6. A method for preparing powder coating for aluminum profiles, characterized in that, The preparation method is used to prepare the aluminum profile spray powder coating as described in claim 5, and the preparation method includes the following steps: S1. Add the modified resin base, modified filler, antioxidant, film-forming aid, curing agent, curing accelerator, leveling agent, gloss agent, degassing agent and pigment to the mixing tank, mix evenly to obtain a mixture; S2. The mixture is added to a twin-screw extruder and fully melted and mixed to form a molten material; S3. The molten material is cooled by a cooling press to solidify it, then crushed and sieved to obtain aluminum profile powder coating.

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