Functional powder coating applied to building aluminum template

Abstract

According to the functional powder coating applied to the building aluminum template, provided by the invention, the alkali resistance and corrosion resistance of a coating are remarkably improved through fluorosilane modification, so that the coating can adapt to a coastal high-salt and high-alkali severe environment; due to the introduction of the UV curing process, the ultraviolet aging resistance of the coating is enhanced, and pulverization and discoloration are effectively avoided; meanwhile, the optimized resin cross-linked structure greatly improves the adhesion resistance and the wear resistance on the basis of keeping flexible adhesion, so that the aluminum template achieves the residue-free and polishing-free effects in the repeated demolding process, and a demolding agent is not brushed, so that the construction efficiency is remarkably improved, the maintenance cost is reduced, the service life of the template is prolonged, and the service life of the template is prolonged. The obvious technical and economic comprehensive advantages are shown.

Description

Technical Field

[0001] This invention belongs to the technical field of aluminum formwork powder coatings, specifically relating to a functional powder coating applied to building aluminum formwork. Background Technology

[0002] In the field of aluminum formwork surface protection and release coating technology, traditional epoxy resin-based powder coatings have gradually revealed several key technical bottlenecks when dealing with modern construction, especially in coastal areas and high-strength cement pouring scenarios. Existing technologies typically use conventional bisphenol A epoxy resin combined with phenolic curing agents to construct the coating system, which has limited cross-linking density and chemical stability of the cured network. When faced with the continuous exothermic environment (up to 60°C) and alkaline conditions generated during cement hydration, the polymer chain mobility of the coating increases, and the surface microstructure is easily damaged, leading to a significant decrease in its anti-adhesion performance and stubborn adhesion of cement slurry to the formwork surface. This not only causes difficulties in demolding and requires significant manual labor for subsequent grinding and cleaning, but also damages the formwork substrate, drastically shortening its cycle life.

[0003] Particularly noteworthy is that in coastal areas or construction environments using high-grade cement, concrete slurry typically exhibits stronger alkalinity, placing more stringent demands on the chemical corrosion resistance of the coating. Under prolonged exposure to such highly alkaline media, ordinary epoxy coatings are prone to ester bond hydrolysis or molecular chain breakage, resulting in chalking, loss of gloss, and even peeling, thus losing their protective function. Furthermore, while traditional thermosetting processes can achieve basic coating formation, they often struggle to balance curing speed and coating performance. Relying solely on thermosetting requires a long curing time to ensure full cross-linking, impacting production efficiency; and the resulting coating network has weak resistance to ultraviolet radiation, making it prone to yellowing and aging under outdoor storage or prolonged sunlight exposure, affecting both aesthetics and performance.

[0004] Addressing and resolving these issues has significant engineering and economic value. As reusable building formwork, the lifespan and demolding efficiency of aluminum formwork directly impact construction costs, project progress, and building quality. A coating that achieves "residue-free demolding" and possesses long-lasting alkali resistance and weather resistance can significantly reduce formwork maintenance costs, prevent concrete surface contamination, improve construction efficiency, and promote the development of green construction technologies. Therefore, developing an innovative resin system and matching molding process capable of forming higher cross-linking density, stronger chemical resistance, and incorporating light-aging resistant structures has become an urgent need for technological upgrades in this field. This is not only an inherent requirement for improving the performance of aluminum formwork products but also a crucial link in adapting to complex and diverse construction environments and promoting the development of industrialized construction. Summary of the Invention

[0005] This invention discloses a functional powder coating for use on building aluminum formwork, to solve any of the above-mentioned and potential problems in the prior art. To solve the above-mentioned technical problems, the specific process of this invention is as follows: The powder coating component formula is as follows, by weight: 400-500 parts modified epoxy resin, 150-220 parts bisphenol A type high-purity solid epoxy resin, 110-120 parts phenolic curing agent, 4-7 parts photoinitiator, 120-140 parts rutile titanium dioxide, 200-220 parts silica powder, 50-80 parts barium sulfate, 2-5 parts carbon black powder, 10-16 parts leveling agent, 10-14 parts gloss enhancer, 3-6 parts benzoin, 8-15 parts polytetrafluoroethylene wax, and 3-6 parts dimethylimidazole.

[0006] The preparation of the modified epoxy resin includes: in a first reactor, 100-120 parts of n-decyltrimethoxysilane and 50-60 parts of perfluorodecyltriethoxysilane are mixed and stirred at 45°C for 40 minutes to obtain a fluorosilane mixture; in a second reactor equipped with nitrogen protection, 850-1000 parts of bisphenol A type solid epoxy resin are added and heated to 110°C to melt it; then, the fluorosilane mixture and 1 part of titanate catalyst are slowly added dropwise to the second reactor; under a nitrogen atmosphere, the temperature of the reaction system is raised to 125°C and maintained at 125°C for 4-5 hours; after the reaction, small molecule byproducts are removed at 110°C and a vacuum of -0.098MPa for 1.5 hours, and finally the temperature is lowered to below 80°C for discharge and cooling to obtain the modified epoxy resin.

[0007] Powder coatings also include the following preparation processes: a. Premixing: Weigh 400-500 parts of modified epoxy resin, 150-220 parts of bisphenol A type high-purity solid epoxy resin, 110-120 parts of phenolic curing agent, 4-7 parts of photoinitiator, 120-140 parts of rutile titanium dioxide, 200-220 parts of silica powder, 50-80 parts of barium sulfate, 2-5 parts of carbon black powder, 10-16 parts of leveling agent, 10-14 parts of brightening agent, 3-6 parts of benzoin, 8-15 parts of polytetrafluoroethylene wax, and 3-6 parts of dimethylimidazole; put all raw materials into a high-speed mixer, first mix at a low speed of 200 rpm for 10 minutes, then switch to a high speed of 500-900 rpm for 25 minutes to ensure that all components are evenly dispersed. b. Melt extrusion: The premixed material is fed into a twin-screw extruder. The temperature of the first zone of the extruder is controlled at 85-95℃, the temperature of the second zone is 105-115℃, the temperature of the third zone is 110-120℃, and the temperature of the die head is 100-110℃ for melt extrusion. c. Tableting, cooling and coarse crushing: The extruded molten material is pressed into thin sheets of 1-2 mm thickness through cooling rollers and cooled to below 35°C, and then coarsely crushed into fragments of 5-10 mm size; d. Fine grinding and classification: The fragments are fed into an air classifier mill system for grinding, and the median particle size distribution (D50) of the finished powder is controlled to be 32-40 micrometers. Excessively fine powder is captured and reused by a recycling system. e. Sieving and Packaging: The ground powder is sieved using a 180-mesh vibrating screen to remove impurities and coarse particles. Qualified products are then packaged in moisture-proof packaging.

[0008] The titanate catalyst is tetrabutyl titanate.

[0009] Among them, the phenolic curing agent is TS-201 modified high-temperature phenolic curing agent.

[0010] The photoinitiator consists of 3-5 parts of bis(4-tert-butylphenyl)iodonium hexafluorophosphate and 1-2 parts of 2-hydroxy-2-methyl-1-phenyl-1-propanone.

[0011] The leveling agent is a solid leveling agent of the GLP503 series.

[0012] Among them, the brightening agents are BLC701 and BLC701B wetting accelerators.

[0013] The advantages and beneficial effects of this invention are as follows: The functional powder coating for aluminum formwork provided by this invention significantly improves the overall performance of the coating through resin modification technology and optimized powder formulation, making it particularly suitable for high-alkalinity, high-salinity coastal construction environments and high-strength cement pouring scenarios. Its core advantage lies in the fact that through molecular structure design and functional component compounding, the coating maintains low surface activity and high cross-linking density even in high-temperature alkaline environments, thus achieving residue-free, sanding-free, and release agent-free demolding, while significantly extending the service life of the aluminum formwork.

[0014] First, the coating exhibits excellent superhydrophobic / oleophobic properties and chemical stability, primarily due to the co-hydrolysis and chemical grafting of n-decyltrimethoxysilane (long-chain alkyl) and perfluorodecyltriethoxysilane (fluorocarbon chain) during the resin modification process. This process successfully constructs an organic-inorganic hybrid structure: the n-decyl long chain imparts good flexibility and substrate adhesion to the coating, while the perfluorodecyl chain introduces low surface energy functional groups into the epoxy resin backbone through chemical bonding, significantly reducing the surface energy of the coating and giving it a durable "lotus effect" and antifouling ability, making it difficult for concrete to adhere. Meanwhile, the introduction of fluorosilanes greatly enhances the coating's tolerance to alkaline environments in concrete and its resistance to ultraviolet aging. Compared with unmodified epoxy resin, this system has stronger inertness to alkaline media and can effectively resist high-temperature alkaline erosion generated during cement hydration. It fundamentally solves the technical problem of conventional coatings being easily adhered to and degraded in cement paste at around 60°C, thus achieving long-term resistance to alkali corrosion and impermeability. It not only meets the requirements for use in inland neutral environments but is also suitable for concrete projects in coastal areas with higher pH values.

[0015] Secondly, the coating employs a dual photo-thermal curing mechanism, ensuring rapid shaping and deep cross-linking. In the thermal curing stage, the phenolic curing agent undergoes a traditional thermal cross-linking reaction with the epoxy resin, forming a robust coating skeleton and guaranteeing its mechanical strength. In the photocuring stage, the composite photoinitiator system (including bis(4-tert-butylphenyl)iodonium hexafluorophosphate as a cationic photoinitiator and 2-hydroxy-2-methyl-1-phenyl-1-propanone as a free radical photoinitiator) can efficiently absorb 365 nm ultraviolet light under medium-pressure mercury lamps or ambient light (such as sunlight or ultraviolet light at the construction site), triggering ring-opening polymerization and cross-linking reactions of epoxy groups through cationic and free radical mechanisms, respectively. This not only achieves rapid surface shaping of the coating but also accelerates the curing process, potentially initiating reactions in the fragmentation stage after extrusion or in the early stages after application, thereby increasing the coating's hardness and cross-linking density, achieving "early high strength," which is highly suitable for the needs of rapid turnover construction. Furthermore, through optimized powder forming processes (including precisely controlled melt extrusion and particle size classification), the product exhibits excellent storage stability, application adaptability, and curing efficiency.

[0016] Third, the precise formulation of functional additives and fillers further enhances the coating's performance. Polytetrafluoroethylene wax, acting as an internal lubricant and wear-resistant agent, works synergistically with fluorosilicone-modified resin to significantly reduce the surface friction coefficient, further improving demolding effect and wear resistance. Dimethylimidazole, as a latent curing accelerator, can precisely control the curing reaction rate, ensuring storage stability and rapid curing during application. The synergistic use of different types of epoxy resins optimizes the coating's weather resistance and mechanical strength, with superior anti-yellowing properties compared to pure epoxy systems, compensating for the shortcoming of easy chalking during long-term outdoor use. Furthermore, functional fillers such as rutile titanium dioxide and silica fume enhance the coating's impact resistance and UV aging resistance, while the addition of leveling agents and gloss enhancers collectively endows the coating with excellent surface smoothness, gloss, and durable anti-stick properties.

[0017] In summary, this invention, through fluoro / silicone synergistic modification, a photo-thermal dual curing mechanism, and the compounding of functional components, enables the powder coating to exhibit advantages such as broad environmental adaptability, long lifespan, and low maintenance costs. This powder coating not only possesses long-lasting corrosion resistance, impermeability, and superhydrophobic properties, but also maintains high performance under harsh construction conditions, significantly reducing the maintenance frequency and overall operating costs of aluminum formwork. Therefore, this invention provides not only a high-performance powder product, but also a material solution for improving the quality and efficiency of building construction. Detailed Implementation

[0018] The present invention will be further described in detail below with reference to the embodiments. The high-purity bisphenol A type solid epoxy resin is TS-904H bisphenol A type solid epoxy resin, purchased from Anhui Tiansheng New Materials Co., Ltd., with an epoxy equivalent of 840-900 g / eq, a specific gravity of 1.18 g / cm at 25℃, a melt viscosity of 6000-9000 CPS at 150℃, a softening point of 100-112℃, and a color of 0.0-1.2 Gardner. The bisphenol A type solid epoxy resin is TS-907, with an epoxy equivalent of 1500-1800 g / eq, a melt viscosity Y-Z2 at 25℃, a softening point of 120-130℃, and a color of 1.0-1.8 Gardner. The phenolic curing agent is TS-201 modified high-temperature phenolic curing agent, purchased from Anhui Tiansheng New Materials Co., Ltd., with a phenolic hydroxyl equivalent of 220-260 (g / eq), a melt viscosity of 2000-10000 (@150℃), a softening point of 100-110 (℃), and a color of 1.0 (G).

[0019] The leveling agent is a GLP503 series solid leveling agent, purchased from Ningbo Nanhai Chemical Co., Ltd., and its specific technical parameters are shown in the table below.

[0020]

[0021] The brightening agent is BLC701 or BLC701B wetting accelerator, wherein BLC701 has a solid content ≥99% and a ring and ball softening point of 95-125℃; and BLC701B has a solid content ≥99% and a ring and ball softening point of 95-125℃.

[0022] The polytetrafluoroethylene wax was PTN806, purchased from Suzhou Partner Environmental New Materials Co., Ltd., with a melting range of 320 (°C), a particle size of 3-5 μm, and a density of 2.2 (25°C).

[0023] Example 1 Resin modification treatment: In the first reactor, 110g of n-decyltrimethoxysilane and 55g of perfluorodecyltriethoxysilane were mixed and stirred at 45°C for 40 minutes to obtain a fluorosilane mixture; In the second reactor equipped with nitrogen protection, 900g of bisphenol A type solid epoxy resin was added and heated to 110°C to melt it; Subsequently, the fluorosilane mixture and 1g of tetrabutyl titanate were slowly added dropwise to the second reactor; Under a nitrogen atmosphere, the temperature of the reaction system was raised to 125°C and maintained at 125°C for 4.5 hours; After the reaction was completed, small molecule byproducts were removed at 110°C and a vacuum of -0.098MPa for 1.5 hours, and finally the temperature was lowered to 75°C for discharge and cooling to obtain the modified epoxy resin.

[0024] Powder Preparation: Accurately weigh the following according to the specified proportions: 450g of the modified epoxy resin, 195g of bisphenol A type high-purity solid epoxy resin, 115g of TS-201 modified high-temperature phenolic curing agent, 4g of bis(4-tert-butylphenyl)iodonium hexafluorophosphate, 1.5g of 2-hydroxy-2-methyl-1-phenyl-1-propanone, 130g of rutile titanium dioxide, 210g of silica powder, 65g of barium sulfate, 3g of carbon black powder, 13g of GLP503 series solid leveling agent, BLC701, and BLC701B. 12g of wetting accelerator, 4g of benzoin, 12g of polytetrafluoroethylene wax, and 4g of dimethylimidazole were added to a high-speed mixer. The mixture was first mixed at a low speed of 200 rpm for 10 minutes, then at a high speed of 700 rpm for 25 minutes to ensure uniform dispersion of all components. The premixed material was then fed into a twin-screw extruder, with the extruder zone 1 temperature controlled at 90℃, zone 2 at 110℃, zone 3 at 115℃, and the die head temperature at 105℃ for melt extrusion. The extruded molten material was pressed into 1.5 mm thick sheets using cooling rollers and cooled to below 32℃, then coarsely crushed into 8 mm fragments. These fragments were then fed into an air classifier mill system for grinding, controlling the D50 median diameter of the finished powder to be within 36 micrometers. Excessively fine powder was captured and reused by a recycling system. The ground powder was then sieved using a 180-mesh vibrating screen to remove individual coarse particles and mechanical impurities, yielding the final product powder.

[0025] Example 2 Resin modification treatment: In the first reactor, 100g of n-decyltrimethoxysilane and 60g of perfluorodecyltriethoxysilane were mixed and stirred at 45°C for 40 minutes to obtain a fluorosilane mixture; In the second reactor equipped with nitrogen protection, 850g of bisphenol A type solid epoxy resin was added and heated to 110°C to melt it; Subsequently, the fluorosilane mixture and 1g of tetrabutyl titanate were slowly added dropwise to the second reactor; Under a nitrogen atmosphere, the temperature of the reaction system was raised to 125°C and maintained at 125°C for 5 hours; After the reaction was completed, small molecule byproducts were removed at 110°C and a vacuum of -0.098MPa for 1.5 hours, and finally the temperature was lowered to 78°C for discharge and cooling to obtain the modified epoxy resin.

[0026] Powder preparation: Accurately weigh the following according to the formula: 400g of the modified epoxy resin, 200g of bisphenol A type high-purity solid epoxy resin, 120g of TS-201 modified high-temperature phenolic curing agent, 3g of bis(4-tert-butylphenyl)iodonium hexafluorophosphate, 2g of 2-hydroxy-2-methyl-1-phenyl-1-propanone, 120g of rutile titanium dioxide, 220g of silica powder, 50g of barium sulfate, 5g of carbon black powder, 10g of GLP503 series solid leveling agent, BLC701, and BLC701B. 14g of wetting accelerator, 3g of benzoin, 15g of polytetrafluoroethylene wax, and 3g of dimethylimidazole were added to a high-speed mixer. The mixture was first low-speed mixed at 200 rpm for 10 minutes, then high-speed mixed at 500 rpm for 25 minutes to ensure uniform dispersion of all components. The premixed material was then fed into a twin-screw extruder, with the extruder zone 1 temperature controlled at 85℃, zone 2 at 115℃, zone 3 at 110℃, and the die head temperature at 110℃ for melt extrusion. The extruded molten material was pressed into 1mm thick sheets using cooling rollers and cooled to below 30℃, then coarsely crushed into 5mm fragments. These fragments were then fed into an air classifier mill system for grinding, controlling the D50 median diameter of the finished powder to be within 32 micrometers. Excessively fine powder was captured and reused by a recycling system. The ground powder was then sieved using a 180-mesh vibrating screen to remove individual coarse particles and mechanical impurities, yielding a qualified product.

[0027] Example 3 Resin modification treatment: In the first reactor, 120g of n-decyltrimethoxysilane and 50g of perfluorodecyltriethoxysilane were mixed and stirred at 45°C for 40 minutes to obtain a fluorosilane mixture; In the second reactor equipped with nitrogen protection, 1000g of bisphenol A type solid epoxy resin was added and heated to 110°C to melt it; Subsequently, the fluorosilane mixture and 1g of tetrabutyl titanate were slowly added dropwise to the second reactor; Under a nitrogen atmosphere, the temperature of the reaction system was raised to 125°C and maintained at 125°C for 4 hours; After the reaction was completed, small molecule byproducts were removed at 110°C and a vacuum of -0.098MPa for 1.5 hours, and finally the temperature was lowered to 72°C for discharge and cooling to obtain the modified epoxy resin.

[0028] Powder preparation: Accurately weigh the following according to the formula: 500g of the modified epoxy resin, 180g of bisphenol A type high-purity solid epoxy resin, 110g of TS-201 modified high-temperature phenolic curing agent, 5g of bis(4-tert-butylphenyl)iodonium hexafluorophosphate, 1g of 2-hydroxy-2-methyl-1-phenyl-1-propanone, 140g of rutile titanium dioxide, 200g of silica powder, 80g of barium sulfate, 2g of carbon black powder, 16g of GLP503 series solid leveling agent, BLC701, and BLC701B. 10g of wetting accelerator, 6g of benzoin, 8g of polytetrafluoroethylene wax, and 6g of dimethylimidazole were added to a high-speed mixer. The mixture was first mixed at a low speed of 200 rpm for 10 minutes, then at a high speed of 900 rpm for 25 minutes to ensure uniform dispersion of all components. The premixed material was then fed into a twin-screw extruder, with the extruder zone 1 temperature controlled at 95℃, zone 2 at 105℃, zone 3 at 120℃, and the die head temperature at 100℃ for melt extrusion. The extruded molten material was pressed into 2mm thick sheets using cooling rollers and cooled to below 34℃, then coarsely crushed into 10mm fragments. These fragments were then fed into an air classifier mill system for grinding, controlling the D50 median diameter of the finished powder to be within 40 micrometers. Excessively fine powder was captured and reused by a recycling system. The ground powder was then sieved using a 180-mesh vibrating screen to remove individual coarse particles and mechanical impurities, yielding a qualified product.

[0029] Comparative Example 1 This comparative example uses a traditional epoxy formulation: 600g of bisphenol A type solid epoxy resin and 150g of TS-201 modified high-temperature phenolic curing agent as the base, combined with 130g of rutile titanium dioxide, 100g of silica powder, 200g of barium sulfate, 10g of GLP503 series solid leveling agent, 8g of BLC701 and BLC701B wetting accelerators, 5g of benzoin and 5g of polytetrafluoroethylene wax, and 4g of dimethylimidazole.

[0030] All raw materials are fed into a high-speed mixer and mixed at a low speed of 200 rpm for 10 minutes, then at a high speed of 700 rpm for 25 minutes to ensure uniform dispersion of all components. The premixed material is then fed into a twin-screw extruder, with the extruder temperature controlled at 90°C in zone 1, 110°C in zone 2, 115°C in zone 3, and 105°C at the die head for melt extrusion. The extruded molten material is pressed into 1.5 mm thick sheets through cooling rollers and cooled to below 32°C, then coarsely crushed into 8 mm fragments. These fragments are then fed into an air classifier mill system for grinding, controlling the median particle size distribution (D50) of the finished powder to be within 36 micrometers. Excessively fine powder is captured and reused by a recycling system. The ground powder is then sieved using a 180-mesh vibrating screen to remove individual coarse particles and mechanical impurities, yielding the final product powder.

[0031] Comparative Example 2 Resin modification treatment: In the first reactor, 165g of n-decyltrimethoxysilane was mixed and stirred at 45°C for 40 minutes to obtain a fluorosilane mixture; in the second reactor equipped with nitrogen protection, 900g of bisphenol A type solid epoxy resin was added and heated to 110°C to melt it; then, the fluorosilane mixture and 1g of tetrabutyl titanate were slowly added dropwise to the second reactor; under a nitrogen atmosphere, the reaction system temperature was raised to 125°C and maintained at 125°C for 4.5 hours; after the reaction, small molecule byproducts were removed at 110°C and a vacuum of -0.098MPa for 1.5 hours, and finally the temperature was lowered to 75°C for discharge and cooling to obtain the modified epoxy resin. The remaining powder preparation process is the same as in Example 1.

[0032] Comparative Example 3 The resin modification treatment in this comparative example is the same as in Example 1; the powder preparation process is as follows: accurately weigh 450g of the above modified epoxy resin, 195g of bisphenol A type high-purity solid epoxy resin, 115g of TS-201 modified high-temperature phenolic curing agent, 130g of rutile titanium dioxide, 210g of silica powder, 65g of barium sulfate, 3g of carbon black powder, 13g of GLP503 series solid leveling agent, BLC701, and BLC701B according to the specified ratio. 12g of wetting accelerator, 4g of benzoin, 12g of polytetrafluoroethylene wax, and 4g of dimethylimidazole were added to a high-speed mixer. The mixture was first mixed at a low speed of 200 rpm for 10 minutes, then at a high speed of 700 rpm for 25 minutes to ensure uniform dispersion of all components. The premixed material was then fed into a twin-screw extruder, with the extruder zone 1 temperature controlled at 90℃, zone 2 at 110℃, zone 3 at 115℃, and the die head temperature at 105℃ for melt extrusion. The extruded molten material was pressed into 1.5 mm thick sheets using cooling rollers and cooled to below 32℃, then coarsely crushed into 8 mm fragments. These fragments were then fed into an air classifier mill system for grinding, controlling the D50 median diameter of the finished powder to be within 36 micrometers. Excessively fine powder was captured and reused by a recycling system. The ground powder was then sieved using a 180-mesh vibrating screen to remove individual coarse particles and mechanical impurities, yielding the final product powder.

[0033] Comparative Example 4 The difference between this comparative example and Example 1 is that in this comparative example, bis(4-tert-butylphenyl)iodonium hexafluorophosphate is replaced with benzophenone, and 2-hydroxy-2-methyl-1-phenyl-1-propanone is replaced with 4,4'-dimethylbenzophenone; the rest is the same as in Example 1.

[0034] Comparative Example 5 The resin modification treatment in this comparative example is the same as in Example 1; the powder preparation is as follows: accurately weigh 450g of the above modified epoxy resin, 195g of bisphenol A type high-purity solid epoxy resin, 115g of TS-201 modified high-temperature phenolic curing agent, 5.5g of 2-hydroxy-2-methyl-1-phenyl-1-propanone, 130g of rutile titanium dioxide, 210g of silica powder, 65g of barium sulfate, 3g of carbon black powder, 13g of GLP503 series solid leveling agent, BLC701, and BLC701B according to the specified ratio. 12g of wetting accelerator, 4g of benzoin, 12g of polytetrafluoroethylene wax, and 4g of dimethylimidazole were added to a high-speed mixer. The mixture was first mixed at a low speed of 200 rpm for 10 minutes, then at a high speed of 700 rpm for 25 minutes to ensure uniform dispersion of all components. The premixed material was then fed into a twin-screw extruder, with the extruder zone 1 temperature controlled at 90℃, zone 2 at 110℃, zone 3 at 115℃, and the die head temperature at 105℃ for melt extrusion. The extruded molten material was pressed into 1.5 mm thick sheets using cooling rollers and cooled to below 32℃, then coarsely crushed into 8 mm fragments. These fragments were then fed into an air classifier mill system for grinding, controlling the D50 median diameter of the finished powder to be within 36 micrometers. Excessively fine powder was captured and reused by a recycling system. The ground powder was then sieved using a 180-mesh vibrating screen to remove individual coarse particles and mechanical impurities, yielding the final product powder.

[0035] Comparative Example 6 The resin modification treatment in this comparative example is the same as in Example 1; the powder preparation is as follows: accurately weigh 450g of the above modified epoxy resin, 195g of bisphenol A type high-purity solid epoxy resin, 115g of TS-201 modified high-temperature phenolic curing agent, 5.5g of bis(4-tert-butylphenyl)iodonium hexafluorophosphate, 130g of rutile titanium dioxide, 210g of silica powder, 65g of barium sulfate, 3g of carbon black powder, 13g of GLP503 series solid leveling agent, BLC701, and BLC701B according to the specified ratio. 12g of wetting accelerator, 4g of benzoin, 12g of polytetrafluoroethylene wax, and 4g of dimethylimidazole were added to a high-speed mixer. The mixture was first mixed at a low speed of 200 rpm for 10 minutes, then at a high speed of 700 rpm for 25 minutes to ensure uniform dispersion of all components. The premixed material was then fed into a twin-screw extruder, with the extruder zone 1 temperature controlled at 90℃, zone 2 at 110℃, zone 3 at 115℃, and the die head temperature at 105℃ for melt extrusion. The extruded molten material was pressed into 1.5 mm thick sheets using cooling rollers and cooled to below 32℃, then coarsely crushed into 8 mm fragments. These fragments were then fed into an air classifier mill system for grinding, controlling the D50 median diameter of the finished powder to be within 36 micrometers. Excessively fine powder was captured and reused by a recycling system. The ground powder was then sieved using a 180-mesh vibrating screen to remove individual coarse particles and mechanical impurities, yielding the final product powder.

[0036] Comparative Example 7 The resin modification treatment in this comparative example is the same as in Example 1; the powder preparation is as follows: accurately weigh 450g of the above modified epoxy resin, 195g of bisphenol A type high-purity solid epoxy resin, 115g of TS-201 modified high-temperature phenolic curing agent, 1.5g of bis(4-tert-butylphenyl)iodonium hexafluorophosphate, 4g of 2-hydroxy-2-methyl-1-phenyl-1-propanone, 130g of rutile titanium dioxide, 210g of silica powder, 65g of barium sulfate, 3g of carbon black powder, 13g of GLP503 series solid leveling agent, BLC701, and BLC701B according to the specified ratio. 12g of wetting accelerator, 4g of benzoin, 12g of polytetrafluoroethylene wax, and 4g of dimethylimidazole were added to a high-speed mixer. The mixture was first mixed at a low speed of 200 rpm for 10 minutes, then at a high speed of 700 rpm for 25 minutes to ensure uniform dispersion of all components. The premixed material was then fed into a twin-screw extruder, with the extruder zone 1 temperature controlled at 90℃, zone 2 at 110℃, zone 3 at 115℃, and the die head temperature at 105℃ for melt extrusion. The extruded molten material was pressed into 1.5 mm thick sheets using cooling rollers and cooled to below 32℃, then coarsely crushed into 8 mm fragments. These fragments were then fed into an air classifier mill system for grinding, controlling the D50 median diameter of the finished powder to be within 36 micrometers. Excessively fine powder was captured and reused by a recycling system. The ground powder was then sieved using a 180-mesh vibrating screen to remove individual coarse particles and mechanical impurities, yielding the final product powder.

[0037] Experiment 1: Performance Testing During construction, high-voltage electrostatic spraying equipment is used to evenly adhere powder to the surface of 6061 aluminum templates, forming a 90-micron thick coating. This coating is then cured using a UV curing machine at a wavelength of 365nm and a temperature of 1800mJ / cm². 2 Pre-curing is performed under energy for 5 minutes, followed by heat curing in a circulating air oven at 120°C for 18 minutes, ultimately forming a composite coating on the surface of the aluminum template.

[0038] The above coating was subjected to salt spray corrosion testing according to GB / T10125-2012. The blistering time of salt spray corrosion was measured in a 5% NaCl solution at 35°C. Pull-out force was tested according to GB / T5210-2006. Surface hardness was tested according to GB / T6739-2006. The number of demolding cycles was calculated: when there is obvious film adhesion and blistering on the surface after n cycles, and the surface of the concrete component is uneven with an area greater than 5%, it is recorded as n cycles.

[0039] The results are shown in Table 1 below: Table 1

[0040] As can be seen from the data in Table 1, Examples 1-3 are significantly superior to all comparative examples in terms of salt spray resistance time (≥1150 hours), pull-out force (≥5.2 MPa), surface hardness (7-8 H), and number of cycles (55-58 times). This is attributed to the fact that the present invention constructs a dense cross-linked network through the synergistic effect of fluorosilanes in resin modification (n-decyl chains enhance adhesion and flexibility, while perfluorodecyl chains reduce surface energy), which improves alkali corrosion resistance and impermeability. At the same time, the photo-thermal dual curing mechanism (composite photoinitiator ensures rapid and uniform curing) and the optimized formulation (such as hydrogenated bisphenol A epoxy resin to enhance weather resistance) work synergistically to achieve long-term durability and easy demolding of the coating in a highly alkaline environment. In contrast, Comparative Example 1 suffers from poor corrosion resistance of unmodified epoxy resin, Comparative Example 2 lacks perfluorinated components resulting in insufficient reduction of surface energy, and Comparative Examples 3-7 suffer from insufficient curing due to the absence of photoinitiator or improper formulation, all of which lead to performance degradation. This highlights the comprehensive advantages of the present invention in component design and process control.

Claims

1. A functional powder coating applied to aluminum formwork in construction, characterized in that, The powder coating composition is as follows, by weight: 400-500 parts modified epoxy resin, 150-220 parts bisphenol A type high-purity solid epoxy resin, 110-120 parts phenolic curing agent, 4-7 parts photoinitiator, 120-140 parts rutile titanium dioxide, 200-220 parts silica powder, 50-80 parts barium sulfate, 2-5 parts carbon black powder, 10-16 parts leveling agent, 10-14 parts gloss enhancer, 3-6 parts benzoin, 8-15 parts polytetrafluoroethylene wax, and 3-6 parts dimethylimidazole. The preparation of the modified epoxy resin includes: in a first reactor, mixing 100-120 parts of n-decyltrimethoxysilane and 50-60 parts of perfluorodecyltriethoxysilane, and stirring at 45°C for 40 minutes to obtain a fluorosilane mixture; in a second reactor equipped with nitrogen protection, adding 850-1000 parts of bisphenol A type solid epoxy resin, and heating to 110°C to melt it; then slowly adding the fluorosilane mixture and 1 part of titanate catalyst dropwise to the second reactor; under a nitrogen atmosphere, raising the temperature of the reaction system to 125°C, and maintaining the reaction at 125°C for 4-5 hours; after the reaction is completed, removing small molecule byproducts at 110°C and a vacuum of -0.098 MPa for 1.5 hours, and finally cooling to below 80°C to discharge and cool, obtaining the modified epoxy resin.

2. The functional powder coating applied to building aluminum formwork according to claim 1, characterized in that, The powder coating also includes the following preparation process: a. Premixing: Weigh 400-500 parts of modified epoxy resin, 150-220 parts of bisphenol A type high-purity solid epoxy resin, 110-120 parts of phenolic curing agent, 4-7 parts of photoinitiator, 120-140 parts of rutile titanium dioxide, 200-220 parts of silica powder, 50-80 parts of barium sulfate, 2-5 parts of carbon black powder, 10-16 parts of leveling agent, 10-14 parts of brightening agent, 3-6 parts of benzoin, 8-15 parts of polytetrafluoroethylene wax, and 3-6 parts of dimethylimidazole; put all raw materials into a high-speed mixer, first mix at a low speed of 200 rpm for 10 minutes, then switch to a high speed of 500-900 rpm for 25 minutes to ensure that all components are evenly dispersed. b. Melt extrusion: The premixed material is fed into a twin-screw extruder. The temperature of the first zone of the extruder is controlled at 85-95℃, the temperature of the second zone is 105-115℃, the temperature of the third zone is 110-120℃, and the temperature of the die head is 100-110℃ for melt extrusion. c. Tableting, cooling and coarse crushing: The extruded molten material is pressed into thin sheets of 1-2 mm thickness through cooling rollers and cooled to below 35°C, and then coarsely crushed into fragments of 5-10 mm size; d. Fine grinding and classification: The fragments are fed into an air classifier mill system for grinding, and the median particle size distribution (D50) of the finished powder is controlled to be 32-40 micrometers. Excessively fine powder is captured and reused by a recycling system. e. Sieving and Packaging: The ground powder is sieved using a 180-mesh vibrating screen to remove impurities and coarse particles. Qualified products are then packaged in moisture-proof packaging.

3. The functional powder coating applied to building aluminum formwork according to claim 1, characterized in that, The titanate catalyst is tetrabutyl titanate.

4. A functional powder coating applied to building aluminum formwork according to claim 1 or 2, characterized in that, The phenolic curing agent is TS-201 modified high-temperature phenolic curing agent.

5. The preparation method according to claim 1 or 2, characterized in that, The photoinitiator is composed of 3-5 parts of bis(4-tert-butylphenyl)iodonium hexafluorophosphate and 1-2 parts of 2-hydroxy-2-methyl-1-phenyl-1-propanone.

6. A functional powder coating applied to building aluminum formwork according to claim 1 or 2, characterized in that, The leveling agent is a GLP503 series solid leveling agent.

7. The preparation method according to claim 1 or 2, characterized in that, The brightening agent is BLC701 or BLC701B wetting accelerator.

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