Multifunctional water-based acrylate coating composition and application thereof

Abstract

The invention relates to the technical field of coatings, in particular to a multifunctional water-based acrylate coating composition and application thereof. According to the technical scheme, the coating is prepared from the following raw materials in parts by weight: 40 to 60 parts of acrylate emulsion with a core-shell structure, 10 to 15 parts of hydroxyapatite-graphene composite filler, 5 to 8 parts of fluorosilane modified nano titanium dioxide, 3 to 5 parts of zirconium phosphate-benzotriazole composite ultraviolet light absorber, 2 to 4 parts of blocked polyisocyanate curing agent and 1 to 3 parts of adhesion promoter. 0.5-2 parts of a rheology modifier, and 15-30 parts of deionized water. According to the present invention, the synergistic interaction of the components on the molecular level is achieved, such that the coating synchronously has advantages of good hydrophobicity, good weatherability, good mechanical strength, good corrosion resistance, good self-cleaning property, good long-acting stability and good photoluminescence function, the industry difficulty that the environmental protection and the high performance of the water-based paint are difficult to achieve at the same time is broken, and the bottleneck in the prior art is broken through.

Description

Technical Field

[0001] This invention relates to the field of coating technology, and in particular to a multifunctional waterborne acrylic coating composition and its application. Background Technology

[0002] Waterborne acrylic coatings, with their environmentally friendly properties, low production costs, and good film-forming properties, have been widely used in many fields such as architectural decoration, automotive manufacturing, and industrial equipment protection. However, with the continuous expansion of application scenarios and the increasing complexity of usage environments, the performance defects of traditional waterborne acrylic coatings have gradually become apparent, making it difficult to meet the requirements of modern industry for high-performance and multifunctional coatings.

[0003] The prominent problems of existing waterborne acrylic coatings are mainly reflected in the following aspects: First, insufficient weather resistance. Long-term exposure to ultraviolet radiation, oxygen, and humid environments easily leads to chalking, yellowing, and even cracking of the coating. Statistics show that ordinary waterborne acrylic coatings can only maintain effective protection for 2-3 years in outdoor environments, after which recoating is required, increasing maintenance costs. Second, poor water resistance. After absorbing water, it is prone to blistering and peeling, especially in high humidity or underwater environments, limiting its application in shipbuilding, bridges, and other fields. Third, difficulty in balancing the hardness and flexibility of the coating. Increasing hardness often leads to a decrease in flexibility, causing the coating to become brittle and unable to meet the requirements of some scenarios with high impact resistance. Fourth, weak adhesion to low surface energy substrates such as metals and plastics, making the coating prone to peeling and affecting its application range. Fifth, limited functionality. It typically only provides a single protective function and cannot simultaneously meet multiple needs such as corrosion prevention, antibacterial properties, and self-cleaning, failing to meet the demands of high-end fields for multifunctional coatings.

[0004] To address the aforementioned issues, existing technologies have primarily employed the following improvements: Silicone modification enhances water and weather resistance, but issues such as poor compatibility between silicone and acrylates, and a sticky coating surface, result in poor appearance and feel. Fluoride modification improves water and chemical resistance, but faces challenges of high cost and environmental risks associated with some fluorides, failing to meet environmental protection requirements. Adding fillers such as nano-titanium dioxide and zinc oxide can improve weather resistance to some extent, but nanoparticles are prone to agglomeration, leading to uneven dispersion and ultimately reducing coating performance. Introducing crosslinking agents such as polyisocyanates enhances coating hardness and chemical resistance, but complicates the application process and shortens the coating's pot life, causing inconvenience in practical applications.

[0005] Therefore, existing technologies still have the following shortcomings: First, they fail to effectively solve the balance problem between various properties, such as weather resistance and flexibility, hardness and adhesion, often resulting in compromises. Second, functional modification methods have limitations, making it difficult to achieve comprehensive performance improvement and meet the comprehensive performance requirements of coatings in complex environments. Third, the stability and ease of application of the formulation system need to be improved, such as the dispersion of nanofillers and the compatibility between components, leading to unstable coating quality.

[0006] In summary, this application proposes a multifunctional waterborne acrylic coating composition and its application. Summary of the Invention

[0007] The purpose of this invention is to address the problem that existing acrylic coatings are difficult to improve in terms of overall performance, and to propose a multifunctional waterborne acrylic coating composition and its application.

[0008] In a first aspect, the present invention provides a multifunctional waterborne acrylic coating composition comprising the following components: 40-60 parts of a core-shell structured acrylate emulsion, wherein the core layer of the core-shell structured acrylate emulsion is a fluorinated acrylate copolymer, and the shell layer is an organosilicon-modified acrylate copolymer; 10-15 parts of hydroxyapatite-graphene composite filler, wherein the composite filler is a three-dimensional network structure formed by in-situ growth of hydroxyapatite nanowires on the surface of graphene sheets. 5-8 parts of fluorosilane-modified nano-titanium dioxide, wherein the fluorosilane-modified nano-titanium dioxide is prepared by surface modification of nano-titanium dioxide with 3-(perfluorooctyl)propyltrimethoxysilane; 3-5 parts of zirconium phosphate-benzotriazole composite ultraviolet absorber, wherein the composite ultraviolet absorber is prepared by intercalation of benzotriazole ultraviolet absorber into the interlayer of zirconium phosphate; 2-4 parts of a blocked polyisocyanate curing agent, wherein the blocked polyisocyanate curing agent uses ε-caprolactam as a blocking agent, and the unblocking temperature of the blocked polyisocyanate curing agent is 120-140℃; 1-3 parts of adhesion promoter, wherein the adhesion promoter is a copolymer of γ-(2,3-epoxypropoxy)propyltrimethoxysilane and glycidyl methacrylate; 0.5-2 parts of rheology modifier, wherein the rheology modifier is a compound of hydrophobic modified alkali-swellable emulsion and polyurethane associative thickener in a mass ratio of 2:1; 3-5 parts of hyperbranched polyester-modified nano-silica, the preparation method of which includes the following steps: 80-100 parts of nano-silica by weight, add 400-600 parts of ethanol and 50-80 parts of deionized water, ultrasonically disperse for 20-30 minutes, add 6-12 parts of 3-aminopropyltriethoxysilane, adjust the pH to 4.5-5.5 with glacial acetic acid, stir and react at 70-80℃ for 3-5 hours, centrifuge, wash 3-4 times with ethanol, vacuum dry at 60-70℃ for 5-6 hours to obtain amino-functionalized nano-silica, and take 100 parts of dimethylolpropionic acid, 5-10 parts of pentaerythritol, 0.8-1.5 parts of p-toluenesulfonic acid, and dimethylolpropionic acid. 20-30 parts of benzene are heated to 150-160℃ under nitrogen protection and reacted for 5-7 hours. During the reaction, water generated is separated by a water separator. After the reaction is completed, xylene is removed by vacuum distillation to obtain hydroxyl-terminated hyperbranched polyester. 100 parts of the obtained amino-functionalized nano silica are taken and 300-500 parts of N,N-dimethylacetamide are added. The mixture is ultrasonically dispersed for 30 minutes. 25-45 parts of the obtained hydroxyl-terminated hyperbranched polyester and 2-5 parts of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride are added. The mixture is stirred and reacted at 50-60℃ for 8-10 hours. After centrifugation, the mixture is washed 2-3 times with acetone and vacuum dried at 80-90℃ for 10-12 hours to obtain hyperbranched polyester-modified nano silica. The rare earth-doped strontium aluminate long afterglow luminescent material comprises 2-4 parts, and the preparation method of the rare earth-doped strontium aluminate long afterglow luminescent material includes the following steps: weigh 100 parts of strontium nitrate, 180-220 parts of aluminum chloride, 2-4 parts of europium nitrate, 3-6 parts of dysprosium nitrate, and 8-12 parts of boric acid according to weight, add 400-600 parts of deionized water, stir until completely dissolved, add 10-15 parts of polyvinylpyrrolidone, stir to form a uniform sol, dry the sol at 80-90℃ to form a dry gel, grind it, place it in a corundum crucible, and heat it to 1250-1350℃ at a rate of 3-5℃ / min under a nitrogen atmosphere, and hold at the temperature. After 3-5 hours of cooling, the mixture is ground through a 200-mesh sieve to obtain europium and dysprosium co-doped strontium aluminate. 100 parts of the europium and dysprosium co-doped strontium aluminate are taken, and 300-500 parts of ethanol and 100-150 parts of deionized water are added. The mixture is ultrasonically dispersed for 40-50 minutes, and 20-30 parts of sodium silicate are added. The pH is adjusted to 7.5-8.5 with dilute sulfuric acid. The mixture is stirred and reacted at 40-50℃ for 4-6 hours, centrifuged, dried at 60-70℃ for 6-8 hours, and then placed in a muffle furnace. The mixture is calcined at 700-800℃ in air for 2-3 hours, cooled, and ground through a 300-mesh sieve to obtain rare earth-doped strontium aluminate long afterglow luminescent material. 1-3 parts of polydopamine-modified boron nitride nanosheets are used. The preparation method of the polydopamine-modified boron nitride nanosheets includes the following steps: 100 parts of boron nitride nanosheets are taken by weight, and 2000-3000 parts of deionized water are added. The mixture is ultrasonically treated at a power of 300-500W for 90-120 minutes to obtain a boron nitride nanosheet dispersion. 15-25 parts of dopamine hydrochloride are added to the dispersion, and after stirring to dissolve, a 0.1 mg / L solution is added. 100-200 parts of 1 ol / L tris(hydroxymethyl)aminomethane buffer were used to adjust the pH to 8.2-8.8. The mixture was stirred at 25-30℃ in the dark for 18-24 hours. The reaction solution was centrifuged at 4000-6000 r / min for 15-20 minutes, the precipitate was collected, washed with deionized water until the filtrate was neutral, washed twice with ethanol, and dried under vacuum at 70-80℃ for 12-15 hours to obtain polydopamine-modified boron nitride nanosheets. 15-30 parts deionized water.

[0009] Optionally, the preparation method of the core-shell structured acrylate emulsion includes: Add 20-30 parts of methyl methacrylate, 10-20 parts of butyl acrylate, 5-10 parts of trifluoroethyl methacrylate, 2-3 parts of acrylic acid, 0.2-0.5 parts of ammonium persulfate initiator, and 0.5-1 parts of sodium dodecylbenzenesulfonate emulsifier to the reaction vessel and react at 75-85℃ for 3-4 hours. Add dropwise a mixture consisting of 15-25 parts methyl methacrylate, 10-15 parts ethyl acrylate, 5-10 parts γ-methacryloyloxypropyltrimethoxysilane, and 0.1-0.3 parts ammonium persulfate as an initiator, and react at 80-90℃ for 2-3 hours. After the reaction is complete, the temperature is lowered to 40-50℃, and ammonia is added to adjust the pH to 7-8 to obtain a core-shell structured acrylate emulsion.

[0010] Optionally, the preparation method of the hydroxyapatite-graphene composite filler includes: Graphene oxide is dispersed in deionized water and ultrasonically treated for 30-60 minutes to form a graphene oxide dispersion with a concentration of 0.5-2 mg / mL. Calcium nitrate and ammonium dihydrogen phosphate were added to the graphene oxide dispersion, with a calcium-to-phosphorus molar ratio of 1.67, and the mixture was stirred until homogeneous. Under stirring, slowly add ammonia water to adjust the pH value to 9-10, and then react at 80-90℃ for 6-12 hours; After the reaction is complete, the mixture is cooled to room temperature, filtered, washed, and dried. Then, it is calcined at 400-500℃ for 2-3 hours under a nitrogen atmosphere to obtain the hydroxyapatite-graphene composite filler.

[0011] Optionally, the preparation method of the fluorosilane-modified nano-titanium dioxide includes: Nano-titanium dioxide is dispersed in anhydrous ethanol and ultrasonically treated for 30-60 minutes to form a nano-titanium dioxide dispersion with a concentration of 5-10 wt%. 3-(perfluorooctyl)propyltrimethoxysilane was added to the nano-titanium dioxide dispersion, with a mass ratio of nano-titanium dioxide to 3-(perfluorooctyl)propyltrimethoxysilane of 10:1-5, and the mixture was stirred until homogeneous. The reaction was refluxed at 60-80℃ for 6-12 hours. After the reaction was completed, the mixture was cooled to room temperature, filtered, washed, and dried to obtain fluorosilane-modified nano-titanium dioxide.

[0012] Optionally, the preparation method of the zirconium phosphate-benzotriazole composite ultraviolet absorber includes: Zirconium phosphate was dispersed in deionized water and ultrasonically treated for 30-60 minutes to form a zirconium phosphate dispersion with a concentration of 1-5 wt%. Add a benzotriazole UV absorber to the zirconium phosphate dispersion, wherein the mass ratio of zirconium phosphate to benzotriazole UV absorber is 1:0.2-0.5, and stir until homogeneous; The reaction was carried out at 50-70℃ for 8-16 hours. After the reaction was completed, the mixture was cooled to room temperature, filtered, washed, and dried to obtain the zirconium phosphate-benzotriazole composite ultraviolet absorber.

[0013] Optionally, it may also include 0.5-2 parts of nano zinc oxide, wherein the nano zinc oxide has a particle size of 20-50 nm.

[0014] Optionally, it may also include 1-3 parts of polyether-modified polydimethylsiloxane defoamer.

[0015] Optionally, it may also include 0.5-2 parts of a compound preservative of 2-methyl-4-isothiazolin-3-one and 5-chloro-2-methyl-4-isothiazolin-3-one.

[0016] Optionally, the multifunctional waterborne acrylic coating composition consists of a separately stored liquid phase and a functional phase, and the preparation method is as follows: The preparation of the liquid phase involves first aging the core-shell structured acrylate emulsion at a low temperature of 5-10℃ for 12-24 hours, then slowly heating it to 40±2℃ at a speed of 200-500 r / min under nitrogen protection, and stirring at a constant temperature for 30-45 minutes. Subsequently, an adhesion promoter, a rheology modifier, and deionized water are added, and the mixture is ground online 3-5 times using a three-roll mill with the grinding gap controlled at 10-15 μm. Finally, the pH value of the system is precisely adjusted to 7.8-8.2 using an organic amine pH adjuster to obtain the liquid phase. The functional phase was prepared by first pretreating hydroxyapatite-graphene composite filler, fluorosilane-modified nano-titanium dioxide, zirconium phosphate-benzotriazole composite ultraviolet absorber, blocked polyisocyanate curing agent, hyperbranched polyester-modified nano-silica, rare earth-doped strontium aluminate long afterglow luminescent material, and polydopamine-modified boron nitride nanosheets in an ultrasonic field at a frequency of 40 kHz and a power of 800 W for 20-30 minutes. Then, the mixture was transferred to a microwave reactor and irradiated for 5-8 minutes at a power of 600 W and a temperature of 60 ± 5 ℃. Subsequently, a blocked polyisocyanate curing agent with bisulfite as a blocking agent was added, and the mixture was stirred at high speed under a vacuum of -0.08 to -0.10 MPa and a rotation speed of 800-1000 r / min. At the same time, cooling water was introduced to keep the system temperature below 35 ℃ until a uniform paste with a particle size D50 ≤ 15 μm was formed, thus obtaining the functional phase. The system employs a dual-channel dynamic impact mixing technology, where the liquid phase and functional phase are respectively injected into the mixing chamber in jet form through two channels with an inner diameter ratio of 3:1, under conditions of pressure 0.4-0.6MPa and temperature 25-30℃. The two liquid streams collide at high speed at a 120° angle, generating an instantaneous shear rate as high as 10. 4 -10 5 s -1 To achieve the turbulent mixing effect, the mixing time is controlled between 90 and 120 seconds to obtain a mixed coating. The mixed coating is immediately passed through a processing pipe equipped with rare earth permanent magnets and oriented under a magnetic field strength of 0.3-0.5T for 60-90 seconds. Finally, it is left to stand and mature for 20-30 minutes in the dark.

[0017] The above preparation process enables the alkaline components in the liquid phase to undergo a directional and controllable desealing reaction with the closed curing agent in the functional phase, resulting in a high desealing rate while ensuring the optimal functional integrity of each component.

[0018] In a second aspect, the present invention provides an application of the multifunctional waterborne acrylic coating composition as described in the first aspect, used as an anti-corrosion coating for metal surfaces.

[0019] Compared with the prior art, this application includes at least one of the following beneficial technical effects: 1. The core-shell structured acrylate emulsion forms the basis of the coating. Its fluorinated acrylate core significantly reduces the surface energy of the coating, while the organosilicon-modified acrylate shell enhances the crosslinking density by forming a high-bond-energy Si-O-Si network. The combination of the two solves the fluorosilicone compatibility problem at the molecular level, providing the coating with excellent initial hydrophobicity, weather resistance, and mechanical strength.

[0020] 2. The three-dimensional network formed by the in-situ growth of hydroxyapatite nanowires on the graphene surface not only physically blocks the penetration of water, oxygen, and corrosive media, but also enhances the coating's toughness and substrate adhesion through the mechanical interlocking effect of the nanowires. Fluorosilane-modified nano-titanium dioxide accumulates on the coating surface, further strengthening its superhydrophobic properties, making it difficult for contaminants to adhere and achieving a self-cleaning function. The zirconium phosphate-benzotriazole composite UV absorber utilizes an interlayer slow-release mechanism to effectively solve the problems of easy migration and decomposition of organic UV absorbers, achieving long-lasting and stable UV shielding and greatly delaying the photoaging of the coating.

[0021] 3. Hyperbranched polyester-modified nano-silica, with its abundant terminal hydroxyl groups, reacts with other components in the system (such as curing agents and adhesion promoters), greatly enhancing the crosslinking density and cohesion of the coating, significantly improving hardness and wear resistance, and improving the dispersion stability of all nanofillers. Polydopamine-modified boron nitride nanosheets, leveraging the strong adhesion of polydopamine and the sheet-like barrier properties of boron nitride, construct a denser labyrinthine barrier pathway within the coating, synergistically enhancing water resistance and salt spray resistance to the extreme, in conjunction with core-shell emulsions and composite fillers. Rare-earth-doped strontium aluminate long-afterglow luminescent materials integrate long-lasting photoluminescent warning or decorative functions into the coating without sacrificing other properties; their silicate coating ensures their stability in complex chemical environments.

[0022] In summary, this invention establishes excellent basic performance through the synergistic effect of fluorine and silicon in the core-shell structured acrylate emulsion. The hydroxyapatite-graphene three-dimensional network, fluorosilane-modified nano-titanium dioxide, and zirconium phosphate-benzotriazole composite UV absorber enhance protection in terms of physical barrier, hydrophobic self-cleaning, and long-term weather resistance, respectively. The newly added hyperbranched polyester-modified nano-silica, polydopamine-modified boron nitride nanosheets, and rare earth-doped strontium aluminate long-afterglow luminescent material further enhance crosslinking, construct a dense barrier, and integrate luminescent functions, achieving synergistic effects of each component at the molecular level. This enables the coating to simultaneously possess good hydrophobicity, weather resistance, mechanical strength, corrosion resistance, self-cleaning, long-term stability, and photoluminescence, breaking through the industry dilemma of water-based coatings being unable to balance environmental protection and high performance, and overcoming the existing technological bottlenecks. Detailed Implementation

[0023] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0024] Example 1 First, prepare the following raw materials: The specific preparation steps for core-shell structured acrylate emulsions are as follows: 20 parts of methyl methacrylate, 10 parts of butyl acrylate, 5 parts of trifluoroethyl methacrylate, 2 parts of acrylic acid, 0.2 parts of ammonium persulfate initiator, and 0.5 parts of sodium dodecylbenzene sulfonate emulsifier were added to the reaction vessel and reacted at 75°C for 3 hours. A mixture consisting of 15 parts methyl methacrylate, 10 parts ethyl acrylate, 5 parts γ-methacryloyloxypropyltrimethoxysilane, and 0.1 parts ammonium persulfate as an initiator was added dropwise, and the mixture was reacted at 80°C for 2 hours. After the reaction was completed, the temperature was lowered to 40°C, and ammonia was added to adjust the pH to 7, thus obtaining a core-shell structured acrylate emulsion.

[0025] A hydroxyapatite-graphene composite filler is prepared, wherein the composite filler is a three-dimensional network structure formed by in-situ growth of hydroxyapatite nanowires on the surface of graphene sheets; the preparation method of the hydroxyapatite-graphene composite filler includes: Graphene oxide was dispersed in deionized water and ultrasonically treated for 30 minutes to form a graphene oxide dispersion with a concentration of 0.5-2 mg / mL. Calcium nitrate and ammonium dihydrogen phosphate were added to the graphene oxide dispersion, with a calcium-to-phosphorus molar ratio of 1.67, and the mixture was stirred until homogeneous. Ammonia was slowly added dropwise under stirring to adjust the pH to 9, and then the reaction was carried out at 80°C for 6 hours. After the reaction was completed, the mixture was cooled to room temperature, filtered, washed, and dried. Then, it was calcined at 400°C for 2 hours under a nitrogen atmosphere to obtain the hydroxyapatite-graphene composite filler.

[0026] The preparation method for fluorosilane-modified nano-titanium dioxide includes: Nano-titanium dioxide was dispersed in anhydrous ethanol and ultrasonically treated for 30 minutes to form a nano-titanium dioxide dispersion with a concentration of 5wt%. 3-(perfluorooctyl)propyltrimethoxysilane was added to the nano-titanium dioxide dispersion, with a mass ratio of nano-titanium dioxide to 3-(perfluorooctyl)propyltrimethoxysilane of 10:1-5, and the mixture was stirred until homogeneous. The reaction was refluxed at 60℃ for 6 hours. After the reaction was completed, the mixture was cooled to room temperature, filtered, washed, and dried to obtain fluorosilane-modified nano-titanium dioxide.

[0027] The preparation method for zirconium phosphate-benzotriazole composite ultraviolet absorber includes: Zirconium phosphate was dispersed in deionized water and ultrasonically treated for 30 minutes to form a 1 wt% zirconium phosphate dispersion. Add a benzotriazole UV absorber to the zirconium phosphate dispersion, wherein the mass ratio of zirconium phosphate to benzotriazole UV absorber is 1:0.2, and stir until homogeneous; The reaction was carried out at 50℃ for 8 hours. After the reaction was completed, the mixture was cooled to room temperature, filtered, washed, and dried to obtain a zirconium phosphate-benzotriazole composite ultraviolet absorber.

[0028] The preparation method of hyperbranched polyester-modified nano-silica includes the following steps: 100 parts by weight of nano-silica are taken, 400 parts by weight of ethanol and 50 parts by weight of deionized water are added, and the mixture is ultrasonically dispersed for 20 minutes. 6 parts by weight of 3-aminopropyltriethoxysilane are added, and the pH is adjusted to 4.5 with glacial acetic acid. The mixture is stirred at 70°C for 3 hours, centrifuged, washed three times with ethanol, and vacuum dried at 60°C for 5 hours to obtain amino-functionalized nano-silica. 100 parts by weight of dimethylolpropionic acid, 5 parts by weight of pentaerythritol, 0.8 parts by weight of p-toluenesulfonic acid, and 20 parts by weight of xylene are also taken. The mixture was heated to 150℃ under nitrogen protection and reacted for 5 hours. During the reaction, water was separated by a water separator. After the reaction, xylene was removed by vacuum distillation to obtain hydroxyl-terminated hyperbranched polyester. 100 parts of the prepared amino-functionalized nano silica were taken and 300 parts of N,N-dimethylacetamide were added. The mixture was ultrasonically dispersed for 30 minutes. 25 parts of the prepared hydroxyl-terminated hyperbranched polyester and 2 parts of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride were added. The mixture was stirred and reacted at 50℃ for 8 hours. After centrifugation, the mixture was washed twice with acetone and vacuum dried at 80℃ for 10 hours to obtain hyperbranched polyester-modified nano silica. A method for preparing rare-earth-doped strontium aluminate long-afterglow luminescent materials includes the following steps: 100 parts by weight of strontium nitrate, 180 parts by weight of aluminum chloride, 2 parts by weight of europium nitrate, 3 parts by weight of dysprosium nitrate, and 8 parts by weight of boric acid are weighed and added to 400 parts by weight of deionized water. The mixture is stirred until completely dissolved. 10 parts by weight of polyvinylpyrrolidone are added and stirred to form a homogeneous sol. The sol is dried at 80°C until a dry gel is formed. After grinding, the gel is placed in a corundum crucible and heated to 1250°C at a rate of 3°C / min under a nitrogen atmosphere. After being kept at a warm temperature for 3 hours and cooled, the mixture was ground through a 200-mesh sieve to obtain europium and dysprosium co-doped strontium aluminate. 100 parts of europium and dysprosium co-doped strontium aluminate were taken, 300 parts of ethanol and 100 parts of deionized water were added, and the mixture was ultrasonically dispersed for 40 minutes. 20 parts of sodium silicate were added, and the pH was adjusted to 7.5 with dilute sulfuric acid. The mixture was stirred and reacted at 40°C for 4 hours, centrifuged, dried at 60°C for 6 hours, and then placed in a muffle furnace and calcined at 700°C in air atmosphere for 2 hours. After cooling, the mixture was ground through a 300-mesh sieve to obtain rare earth-doped strontium aluminate long afterglow luminescent material. Polydopamine-modified boron nitride nanosheets were prepared by means of the following steps: 100 parts by weight of boron nitride nanosheets were taken and 2000 parts by weight of deionized water were added. The mixture was ultrasonically treated at 300W for 90 minutes to obtain a boron nitride nanosheet dispersion. 15 parts by weight of dopamine hydrochloride were added to the dispersion and stirred to dissolve. 100 parts by weight of 0.1 mol / L tris(hydroxymethyl)aminomethane buffer solution were added to adjust the pH to 8.2. The mixture was stirred and reacted at 25°C in the dark for 18 hours. The reaction solution was centrifuged at 4000 r / min for 15 minutes, and the precipitate was collected. The precipitate was washed with deionized water until the filtrate was neutral, then washed twice with ethanol, and dried under vacuum at 70°C for 12 hours to obtain polydopamine-modified boron nitride nanosheets. ②Prepare auxiliary materials: A blocked polyisocyanate curing agent, wherein the blocked polyisocyanate curing agent uses ε-caprolactam as a blocking agent, and the unblocking temperature of the blocked polyisocyanate curing agent is 120°C; An adhesion promoter, wherein the adhesion promoter is a copolymer of γ-(2,3-epoxypropoxy)propyltrimethoxysilane and glycidyl methacrylate; The rheology modifier is a compound of a hydrophobic modified alkali-swellable emulsion and a polyurethane associative thickener in a mass ratio of 2:1. Deionized water; Nano zinc oxide, wherein the particle size of the nano zinc oxide is 20 nm; Polyether-modified polydimethylsiloxane defoamer; A compound preservative of 2-methyl-4-isothiazolin-3-one and 5-chloro-2-methyl-4-isothiazolin-3-one; ③ Mixed coatings: Weigh out 40 parts of core-shell structured acrylate emulsion, 10 parts of hydroxyapatite-graphene composite filler, 5 parts of fluorosilane-modified nano-titanium dioxide, 3 parts of zirconium phosphate-benzotriazole composite ultraviolet absorber, 2 parts of blocked polyisocyanate, 1 part of adhesion promoter (γ-GPTMS-glycidyl methacrylate copolymer), 0.5 parts of rheology modifier (hydrophobic alkali swelling emulsion: polyurethane thickener = 2:1), 0.5 parts of nano-zinc oxide, 1 part of polyether-modified siloxane defoamer, 0.5 parts of compound preservative (2-methyl-4-isothiazolin-3-one: 5-chloro-2-methyl-4-isothiazolin-3-one = 3:1), 3 parts of hyperbranched polyester-modified nano-silica, 2 parts of rare earth-doped strontium aluminate long afterglow luminescent material, 1 part of polydopamine-modified boron nitride nanosheets, and 30 parts of deionized water. The multifunctional waterborne acrylic coating composition consists of a separately stored liquid phase and a functional phase, and the preparation method is as follows: To prepare the liquid phase, the core-shell structured acrylate emulsion was first aged at 5°C for 12 hours. Then, under nitrogen protection, the temperature was slowly increased to 38°C at 200 r / min and stirred for 30 minutes. Subsequently, an adhesion promoter, a rheology modifier, and deionized water were added. The mixture was then ground three times online using a three-roll mill with the grinding gap controlled at 10-15 μm. Finally, the pH of the system was precisely adjusted to 7.8 using an organic amine pH adjuster to obtain the liquid phase. The functional phase was prepared by first pretreating hydroxyapatite-graphene composite filler, fluorosilane-modified nano-titanium dioxide, zirconium phosphate-benzotriazole composite ultraviolet absorber, blocked polyisocyanate curing agent, hyperbranched polyester-modified nano-silica, rare earth-doped strontium aluminate long afterglow luminescent material, and polydopamine-modified boron nitride nanosheets in an ultrasonic field at a frequency of 40 kHz and a power of 800 W for 20 minutes. Then, the mixture was transferred to a microwave reactor and irradiated for 5 minutes at a power of 600 W and a temperature of 55 °C. Subsequently, a blocked polyisocyanate curing agent with bisulfite as a blocking agent was added, and the mixture was stirred at high speed under a vacuum of -0.08 MPa and a rotation speed of 800-1000 r / min. At the same time, cooling water was introduced to keep the system temperature below 35 °C until a uniform paste with a particle size D50 ≤ 15 μm was formed, thus obtaining the functional phase. The system employs a dual-channel dynamic impact mixing technology, where the liquid phase and functional phase are respectively injected into the mixing chamber in jet form through two channels with an inner diameter ratio of 3:1, under conditions of 0.4 MPa pressure and 25°C temperature. The two liquid streams collide at a high speed at a 120° angle, generating an instantaneous shear rate as high as 10. 4 s -1 The turbulent mixing effect was achieved by controlling the mixing time to 90 seconds to obtain a mixed coating. The mixed coating is immediately passed through a processing pipe equipped with rare earth permanent magnets and oriented under a magnetic field strength of 0.3T for 60 seconds. Finally, it is left to stand and mature for 20 minutes under light-proof conditions to obtain a multifunctional water-based acrylic coating composition. This composition is then coated onto a cold-rolled steel plate and cured at 140°C for 20 minutes.

[0029] Example 2 First, prepare the following raw materials: The specific preparation steps for core-shell structured acrylate emulsions are as follows: Add 30 parts of methyl methacrylate, 20 parts of butyl acrylate, 10 parts of trifluoroethyl methacrylate, 3 parts of acrylic acid, 0.5 parts of ammonium persulfate initiator, and 1 part of sodium dodecylbenzene sulfonate emulsifier to the reaction vessel and react at 85°C for 4 hours. A mixture consisting of 25 parts methyl methacrylate, 15 parts ethyl acrylate, 10 parts γ-methacryloyloxypropyltrimethoxysilane, and 0.3 parts ammonium persulfate as an initiator was added dropwise, and the mixture was reacted at 90°C for 3 hours. After the reaction was completed, the temperature was lowered to 50°C, and ammonia was added to adjust the pH to 8, thus obtaining a core-shell structured acrylate emulsion.

[0030] A hydroxyapatite-graphene composite filler is prepared, wherein the composite filler is a three-dimensional network structure formed by in-situ growth of hydroxyapatite nanowires on the surface of graphene sheets; the preparation method of the hydroxyapatite-graphene composite filler includes: Graphene oxide was dispersed in deionized water and ultrasonically treated for 60 minutes to form a graphene oxide dispersion with a concentration of 2 mg / mL. Calcium nitrate and ammonium dihydrogen phosphate were added to the graphene oxide dispersion, with a calcium-to-phosphorus molar ratio of 1.67, and the mixture was stirred until homogeneous. Ammonia was slowly added dropwise under stirring to adjust the pH to 10, and then the reaction was carried out at 90°C for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, filtered, washed, and dried. Then, it was calcined at 500°C for 3 hours under a nitrogen atmosphere to obtain the hydroxyapatite-graphene composite filler.

[0031] The preparation method for fluorosilane-modified nano-titanium dioxide includes: Nano-titanium dioxide was dispersed in anhydrous ethanol and ultrasonically treated for 60 minutes to form a nano-titanium dioxide dispersion with a concentration of 10 wt%. 3-(perfluorooctyl)propyltrimethoxysilane was added to the nano-titanium dioxide dispersion, with a mass ratio of nano-titanium dioxide to 3-(perfluorooctyl)propyltrimethoxysilane of 10:5, and the mixture was stirred until homogeneous. The reaction was refluxed at 80℃ for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, filtered, washed, and dried to obtain fluorosilane-modified nano-titanium dioxide.

[0032] The preparation method for zirconium phosphate-benzotriazole composite ultraviolet absorber includes: Zirconium phosphate was dispersed in deionized water and ultrasonically treated for 60 minutes to form a 5 wt% zirconium phosphate dispersion. Add a benzotriazole UV absorber to the zirconium phosphate dispersion, wherein the mass ratio of zirconium phosphate to benzotriazole UV absorber is 1:0.5, and stir until homogeneous; The reaction was carried out at 70℃ for 16 hours. After the reaction was completed, the mixture was cooled to room temperature, filtered, washed, and dried to obtain a zirconium phosphate-benzotriazole composite ultraviolet absorber.

[0033] The preparation method of hyperbranched polyester-modified nano-silica includes the following steps: 100 parts by weight of nano-silica are taken, 600 parts by weight of ethanol and 80 parts by weight of deionized water are added, and the mixture is ultrasonically dispersed for 30 minutes. 12 parts by weight of 3-aminopropyltriethoxysilane are added, and the pH is adjusted to 5.5 with glacial acetic acid. The mixture is stirred at 80°C for 5 hours, centrifuged, washed 4 times with ethanol, and vacuum dried at 70°C for 6 hours to obtain amino-functionalized nano-silica. 100 parts by weight of dimethylolpropionic acid, 10 parts by weight of pentaerythritol, 1.5 parts by weight of p-toluenesulfonic acid, and 30 parts by weight of xylene are also taken. The mixture was heated to 160℃ under nitrogen protection and reacted for 7 hours. During the reaction, water was separated by a water separator. After the reaction, xylene was removed by vacuum distillation to obtain hydroxyl-terminated hyperbranched polyester. 100 parts of the prepared amino-functionalized nano silica were taken and 500 parts of N,N-dimethylacetamide were added. The mixture was ultrasonically dispersed for 30 minutes. 45 parts of the prepared hydroxyl-terminated hyperbranched polyester and 5 parts of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride were added. The mixture was stirred and reacted at 60℃ for 10 hours. After centrifugation, the mixture was washed three times with acetone and vacuum dried at 90℃ for 12 hours to obtain hyperbranched polyester-modified nano silica. A method for preparing rare-earth-doped strontium aluminate long-afterglow luminescent materials includes the following steps: 100 parts by weight of strontium nitrate, 220 parts by weight of aluminum chloride, 4 parts by weight of europium nitrate, 6 parts by weight of dysprosium nitrate, and 12 parts by weight of boric acid are weighed and added to 600 parts by weight of deionized water. The mixture is stirred until completely dissolved. 15 parts by weight of polyvinylpyrrolidone are added and stirred to form a homogeneous sol. The sol is dried at 90°C until a dry gel is formed. After grinding, the gel is placed in a corundum crucible and heated to 1350°C at a rate of 5°C / min under a nitrogen atmosphere. After being kept at a warm temperature for 5 hours and cooled, the mixture was ground through a 200-mesh sieve to obtain europium and dysprosium co-doped strontium aluminate. 100 parts of europium and dysprosium co-doped strontium aluminate were taken, 500 parts of ethanol and 150 parts of deionized water were added, and the mixture was ultrasonically dispersed for 50 minutes. 30 parts of sodium silicate were added, and the pH was adjusted to 8.5 with dilute sulfuric acid. The mixture was stirred and reacted at 50°C for 6 hours, centrifuged, dried at 70°C for 8 hours, and then placed in a muffle furnace and calcined at 800°C in air atmosphere for 3 hours. After cooling, the mixture was ground through a 300-mesh sieve to obtain rare earth-doped strontium aluminate long afterglow luminescent material. The preparation method of polydopamine-modified boron nitride nanosheets includes the following steps: 100 parts by weight of boron nitride nanosheets are taken and 3000 parts by weight of deionized water are added. The mixture is ultrasonically treated at 500W for 120 minutes to obtain a boron nitride nanosheet dispersion. 25 parts by weight of dopamine hydrochloride are added to the dispersion and stirred to dissolve. 200 parts by weight of 0.1 mol / L tris(hydroxymethyl)aminomethane buffer are added to adjust the pH to 8.8. The mixture is stirred and reacted at 30°C in the dark for 18-24 hours. The reaction solution is centrifuged at 4000-6000 r / min for 20 minutes, the precipitate is collected, washed with deionized water until the filtrate is neutral, washed twice with ethanol, and vacuum dried at 80°C for 15 hours to obtain polydopamine-modified boron nitride nanosheets. ②Prepare auxiliary materials: A blocked polyisocyanate curing agent, wherein the blocked polyisocyanate curing agent uses ε-caprolactam as a blocking agent, and the unblocking temperature of the blocked polyisocyanate curing agent is 140°C; An adhesion promoter, wherein the adhesion promoter is a copolymer of γ-(2,3-epoxypropoxy)propyltrimethoxysilane and glycidyl methacrylate; The rheology modifier is a compound of a hydrophobic modified alkali-swellable emulsion and a polyurethane associative thickener in a mass ratio of 2:1. Deionized water; Nano zinc oxide, wherein the particle size of the nano zinc oxide is 50 nm; Polyether-modified polydimethylsiloxane defoamer; A compound preservative of 2-methyl-4-isothiazolin-3-one and 5-chloro-2-methyl-4-isothiazolin-3-one; ③ Mixed coatings: Weigh out 60 parts of core-shell structured acrylate emulsion, 15 parts of hydroxyapatite-graphene composite filler, 8 parts of fluorosilane-modified nano-titanium dioxide, 5 parts of zirconium phosphate-benzotriazole composite ultraviolet absorber, 4 parts of blocked polyisocyanate, 3 parts of adhesion promoter (γ-GPTMS-glycidyl methacrylate copolymer), 2 parts of rheology modifier (hydrophobic alkali swelling emulsion: polyurethane thickener = 2:1), 2 parts of nano-zinc oxide, 3 parts of polyether-modified siloxane defoamer, 2 parts of compound preservative (2-methyl-4-isothiazolin-3-one: 5-chloro-2-methyl-4-isothiazolin-3-one = 3:1), 5 parts of hyperbranched polyester-modified nano-silica, 4 parts of rare earth-doped strontium aluminate long afterglow luminescent material, 3 parts of polydopamine-modified boron nitride nanosheets, and 15 parts of deionized water. The multifunctional waterborne acrylic coating composition consists of a separately stored liquid phase and a functional phase, and the preparation method is as follows: To prepare the liquid phase, the core-shell structured acrylate emulsion was first aged at 10°C for 24 hours. Then, under nitrogen protection, the temperature was slowly increased to 42°C at 500 r / min and stirred for 45 minutes. Subsequently, an adhesion promoter, a rheology modifier, and deionized water were added. The mixture was then ground online five times using a three-roll mill with the grinding gap controlled at 10-15 μm. Finally, the pH of the system was precisely adjusted to 8.2 using an organic amine pH adjuster to obtain the liquid phase. The functional phase was prepared by first pretreating hydroxyapatite-graphene composite filler, fluorosilane-modified nano-titanium dioxide, zirconium phosphate-benzotriazole composite ultraviolet absorber, blocked polyisocyanate curing agent, hyperbranched polyester-modified nano-silica, rare earth-doped strontium aluminate long afterglow luminescent material, and polydopamine-modified boron nitride nanosheets in an ultrasonic field at a frequency of 40 kHz and a power of 800 W for 30 minutes. Then, the mixture was transferred to a microwave reactor and irradiated for 8 minutes at a power of 600 W and a temperature of 65 °C. Subsequently, a blocked polyisocyanate curing agent with bisulfite as a blocking agent was added, and the mixture was stirred at high speed under vacuum of -0.10 MPa and a rotation speed of 1000 r / min. At the same time, cooling water was introduced to keep the system temperature below 35 °C until a uniform paste with a particle size D50 ≤ 15 μm was formed, thus obtaining the functional phase. The system employs a dual-channel dynamic impact mixing technology, where the liquid phase and functional phase are respectively injected into the mixing chamber in jet form through two channels with an inner diameter ratio of 3:1, under conditions of 0.6 MPa pressure and 30°C temperature. The two liquid streams collide at a high speed at a 120° angle, generating an instantaneous shear rate as high as 10. 5 s -1 The turbulent mixing effect was achieved by controlling the mixing time to 120 seconds to obtain a mixed coating. The mixed coating is immediately passed through a processing pipe equipped with rare earth permanent magnets and oriented under a magnetic field strength of 0.5T for 90 seconds. Finally, it is left to stand and mature for 30 minutes under light-proof conditions to obtain a multifunctional water-based acrylic coating composition. This composition is then coated onto cold-rolled steel sheets and cured at 140°C for 20 minutes.

[0034] Example 3 First, prepare the following raw materials: The specific preparation steps for core-shell structured acrylate emulsions are as follows: 25 parts of methyl methacrylate, 15 parts of butyl acrylate, 7.5 parts of trifluoroethyl methacrylate, 2.5 parts of acrylic acid, 0.35 parts of ammonium persulfate initiator, and 0.75 parts of sodium dodecylbenzene sulfonate emulsifier were added to the reaction vessel and reacted at 80°C for 3.5 hours. A mixture consisting of 20 parts methyl methacrylate, 12.5 parts ethyl acrylate, 7.5 parts γ-methacryloyloxypropyltrimethoxysilane, and 0.2 parts ammonium persulfate as an initiator was added dropwise, and the mixture was reacted at 85°C for 2.5 hours. After the reaction was completed, the temperature was lowered to 45°C, and ammonia was added to adjust the pH to 7.5, thus obtaining a core-shell structured acrylate emulsion.

[0035] A hydroxyapatite-graphene composite filler is prepared, wherein the composite filler is a three-dimensional network structure formed by in-situ growth of hydroxyapatite nanowires on the surface of graphene sheets; the preparation method of the hydroxyapatite-graphene composite filler includes: Graphene oxide was dispersed in deionized water and ultrasonically treated for 45 minutes to form a graphene oxide dispersion with a concentration of 1.25 mg / mL. Calcium nitrate and ammonium dihydrogen phosphate were added to the graphene oxide dispersion, with a calcium-to-phosphorus molar ratio of 1.67, and the mixture was stirred until homogeneous. Ammonia was slowly added dropwise under stirring to adjust the pH to 9.5, and then the reaction was carried out at 85°C for 9 hours. After the reaction was completed, the mixture was cooled to room temperature, filtered, washed, and dried. Then, it was calcined at 450°C for 2.5 hours under a nitrogen atmosphere to obtain the hydroxyapatite-graphene composite filler.

[0036] The preparation method for fluorosilane-modified nano-titanium dioxide includes: Nano-titanium dioxide was dispersed in anhydrous ethanol and ultrasonically treated for 45 minutes to form a nano-titanium dioxide dispersion with a concentration of 7.5 wt%. 3-(perfluorooctyl)propyltrimethoxysilane was added to the nano-titanium dioxide dispersion, with a mass ratio of nano-titanium dioxide to 3-(perfluorooctyl)propyltrimethoxysilane of 10:3, and the mixture was stirred until homogeneous. The reaction was refluxed at 70℃ for 9 hours. After the reaction was completed, the mixture was cooled to room temperature, filtered, washed, and dried to obtain fluorosilane-modified nano-titanium dioxide.

[0037] The preparation method for zirconium phosphate-benzotriazole composite ultraviolet absorber includes: Zirconium phosphate was dispersed in deionized water and ultrasonically treated for 45 minutes to form a 3wt% zirconium phosphate dispersion. Add a benzotriazole UV absorber to the zirconium phosphate dispersion, wherein the mass ratio of zirconium phosphate to benzotriazole UV absorber is 1:0.35, and stir until homogeneous; The reaction was carried out at 60℃ for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, filtered, washed, and dried to obtain a zirconium phosphate-benzotriazole composite ultraviolet absorber.

[0038] The preparation method of hyperbranched polyester-modified nano-silica includes the following steps: 100 parts by weight of nano-silica are taken, 500 parts by weight of ethanol and 65 parts by weight of deionized water are added, and the mixture is ultrasonically dispersed for 25 minutes. 9 parts by weight of 3-aminopropyltriethoxysilane are added, and the pH is adjusted to 5 with glacial acetic acid. The mixture is stirred at 75°C for 4 hours, centrifuged, washed four times with ethanol, and vacuum dried at 65°C for 5.5 hours to obtain amino-functionalized nano-silica. 100 parts by weight of dimethylolpropionic acid, 7.5 parts by weight of pentaerythritol, 1.15 parts by weight of p-toluenesulfonic acid, and 25 parts by weight of xylene are also taken. The mixture was heated to 155℃ under nitrogen protection and reacted for 6 hours. During the reaction, water was separated by a water separator. After the reaction, xylene was removed by vacuum distillation to obtain hydroxyl-terminated hyperbranched polyester. 100 parts of the prepared amino-functionalized nano silica were taken and 400 parts of N,N-dimethylacetamide were added. The mixture was ultrasonically dispersed for 30 minutes. 35 parts of the prepared hydroxyl-terminated hyperbranched polyester and 3.5 parts of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride were added. The mixture was stirred at 55℃ for 9 hours, centrifuged, washed 3 times with acetone, and vacuum dried at 85℃ for 11 hours to obtain hyperbranched polyester modified nano silica. A method for preparing rare-earth-doped strontium aluminate long-afterglow luminescent materials includes the following steps: 100 parts by weight of strontium nitrate, 200 parts by weight of aluminum chloride, 3 parts by weight of europium nitrate, 4.5 parts by weight of dysprosium nitrate, and 10 parts by weight of boric acid are weighed and added to 500 parts by weight of deionized water. The mixture is stirred until completely dissolved. 12.5 parts by weight of polyvinylpyrrolidone are added and stirred to form a homogeneous sol. The sol is dried at 85°C until a dry gel is formed. After grinding, the gel is placed in a corundum crucible and heated to 130°C at a rate of 4°C / min under a nitrogen atmosphere. At 0℃, the mixture was kept at that temperature for 4 hours. After cooling, it was ground through a 200-mesh sieve to obtain europium and dysprosium co-doped strontium aluminate. 100 parts of europium and dysprosium co-doped strontium aluminate were taken, 400 parts of ethanol and 125 parts of deionized water were added, and the mixture was ultrasonically dispersed for 45 minutes. 25 parts of sodium silicate were added, and the pH was adjusted to 8 with dilute sulfuric acid. The mixture was stirred and reacted at 45℃ for 5 hours, centrifuged, dried at 65℃ for 7 hours, and then placed in a muffle furnace and calcined at 750℃ in air atmosphere for 2.5 hours. After cooling, it was ground through a 300-mesh sieve to obtain rare earth-doped strontium aluminate long afterglow luminescent material. The preparation method of polydopamine-modified boron nitride nanosheets includes the following steps: 100 parts by weight of boron nitride nanosheets are taken and 2500 parts by weight of deionized water are added. The mixture is ultrasonically treated at 400W for 105 minutes to obtain a boron nitride nanosheet dispersion. 20 parts by weight of dopamine hydrochloride are added to the dispersion and stirred to dissolve. Then, 150 parts by weight of 0.1 mol / L tris(hydroxymethyl)aminomethane buffer are added to adjust the pH to 8.5. The mixture is stirred and reacted at 27.5℃ in the dark for 21 hours. The reaction solution is centrifuged at 5000 r / min for 17.5 minutes, the precipitate is collected, washed with deionized water until the filtrate is neutral, washed twice with ethanol, and vacuum dried at 70-80℃ for 13.5 hours to obtain polydopamine-modified boron nitride nanosheets. ②Prepare auxiliary materials: A blocked polyisocyanate curing agent, wherein the blocked polyisocyanate curing agent uses ε-caprolactam as a blocking agent, and the unblocking temperature of the blocked polyisocyanate curing agent is 135°C; An adhesion promoter, wherein the adhesion promoter is a copolymer of γ-(2,3-epoxypropoxy)propyltrimethoxysilane and glycidyl methacrylate; The rheology modifier is a compound of a hydrophobic modified alkali-swellable emulsion and a polyurethane associative thickener in a mass ratio of 2:1. Deionized water; Nano zinc oxide, wherein the particle size of the nano zinc oxide is 20-50 nm; Polyether-modified polydimethylsiloxane defoamer; A compound preservative of 2-methyl-4-isothiazolin-3-one and 5-chloro-2-methyl-4-isothiazolin-3-one; ③ Mixed coatings: Weigh out 50 parts of core-shell structured acrylate emulsion, 12 parts of hydroxyapatite-graphene composite filler, 6.5 parts of fluorosilane-modified nano-titanium dioxide, 4 parts of zirconium phosphate-benzotriazole composite ultraviolet absorber, 3 parts of blocked polyisocyanate, 2 parts of adhesion promoter (γ-GPTMS-glycidyl methacrylate copolymer), 1.2 parts of rheology modifier (hydrophobic alkali swelling emulsion: polyurethane thickener = 2:1), 1.2 parts of nano-zinc oxide, 2 parts of polyether-modified siloxane defoamer, 1.2 parts of compound preservative (2-methyl-4-isothiazolin-3-one: 5-chloro-2-methyl-4-isothiazolin-3-one = 3:1), 4 parts of hyperbranched polyester-modified nano-silica, 3 parts of rare earth-doped strontium aluminate long afterglow luminescent material, 2 parts of polydopamine-modified boron nitride nanosheets, and 22 parts of deionized water; The multifunctional waterborne acrylic coating composition consists of a separately stored liquid phase and a functional phase, and the preparation method is as follows: To prepare the liquid phase, the core-shell structured acrylate emulsion was first aged at 8°C for 18 hours. Then, under nitrogen protection, the temperature was slowly increased to 40°C at 350 r / min and stirred for 38 minutes. Subsequently, an adhesion promoter, a rheology modifier, and deionized water were added. The mixture was then ground four times online using a three-roll mill with the grinding gap controlled at 10-15 μm. Finally, the pH of the system was precisely adjusted to 8 using an organic amine pH adjuster to obtain the liquid phase. The functional phase was prepared by first pretreating hydroxyapatite-graphene composite filler, fluorosilane-modified nano-titanium dioxide, zirconium phosphate-benzotriazole composite ultraviolet absorber, blocked polyisocyanate curing agent, hyperbranched polyester-modified nano-silica, rare earth-doped strontium aluminate long afterglow luminescent material, and polydopamine-modified boron nitride nanosheets in an ultrasonic field at a frequency of 40 kHz and a power of 800 W for 25 minutes. Then, the mixture was transferred to a microwave reactor and irradiated at a power of 600 W and a temperature of 60 °C for 6.5 minutes. Subsequently, a blocked polyisocyanate curing agent with bisulfite as a blocking agent was added, and the mixture was stirred at high speed under a vacuum of -0.09 MPa and a rotation speed of 900 r / min. At the same time, cooling water was introduced to keep the system temperature below 35 °C until a uniform paste with a particle size D50 ≤ 15 μm was formed, thus obtaining the functional phase. The system employs a dual-channel dynamic impact mixing technology, where the liquid phase and functional phase are respectively injected into the mixing chamber in jet form through two channels with an inner diameter ratio of 3:1, under conditions of 0.5 MPa pressure and 27°C temperature. The two liquid streams collide at a high speed at a 120° angle, generating an instantaneous shear rate as high as 5*10⁻⁶. 4 s -1 The turbulent mixing effect was achieved by controlling the mixing time to 105 seconds to obtain a mixed coating. The mixed coating is immediately passed through a processing pipe equipped with rare earth permanent magnets and oriented under a magnetic field strength of 0.4T for 75 seconds. Finally, it is left to stand and mature for 25 minutes under light-proof conditions to obtain a multifunctional water-based acrylic coating composition. This composition is then coated onto a cold-rolled steel plate and cured at 140°C for 20 minutes.

[0039] Comparative Example 1: The fluorine / silicon components in the core-shell structure were removed, and a common acrylic emulsion (non-core-shell structure) was used to replace the core-shell emulsion. The rest was the same as in Example 3.

[0040] First, prepare the following raw materials: BASF Acronal S760 waterborne acrylic emulsion (solid content 45±1%, fluorine-free / silicone-free, glass transition temperature Tg=20℃) was used. A hydroxyapatite-graphene composite filler is prepared, wherein the composite filler is a three-dimensional network structure formed by in-situ growth of hydroxyapatite nanowires on the surface of graphene sheets; the preparation method of the hydroxyapatite-graphene composite filler includes: Graphene oxide was dispersed in deionized water and ultrasonically treated for 45 minutes to form a graphene oxide dispersion with a concentration of 1.25 mg / mL. Calcium nitrate and ammonium dihydrogen phosphate were added to the graphene oxide dispersion, with a calcium-to-phosphorus molar ratio of 1.67, and the mixture was stirred until homogeneous. Ammonia was slowly added dropwise under stirring to adjust the pH to 9.5, and then the reaction was carried out at 85°C for 9 hours. After the reaction was completed, the mixture was cooled to room temperature, filtered, washed, and dried. Then, it was calcined at 450°C for 2.5 hours under a nitrogen atmosphere to obtain the hydroxyapatite-graphene composite filler.

[0041] The preparation method for fluorosilane-modified nano-titanium dioxide includes: Nano-titanium dioxide was dispersed in anhydrous ethanol and ultrasonically treated for 45 minutes to form a nano-titanium dioxide dispersion with a concentration of 7.5 wt%. 3-(perfluorooctyl)propyltrimethoxysilane was added to the nano-titanium dioxide dispersion, with a mass ratio of nano-titanium dioxide to 3-(perfluorooctyl)propyltrimethoxysilane of 10:3, and the mixture was stirred until homogeneous. The reaction was refluxed at 70℃ for 9 hours. After the reaction was completed, the mixture was cooled to room temperature, filtered, washed, and dried to obtain fluorosilane-modified nano-titanium dioxide.

[0042] The preparation method for zirconium phosphate-benzotriazole composite ultraviolet absorber includes: Zirconium phosphate was dispersed in deionized water and ultrasonically treated for 45 minutes to form a 3wt% zirconium phosphate dispersion. Add a benzotriazole UV absorber to the zirconium phosphate dispersion, wherein the mass ratio of zirconium phosphate to benzotriazole UV absorber is 1:0.35, and stir until homogeneous; The reaction was carried out at 60℃ for 12 hours. After the reaction was completed, the mixture was cooled to room temperature, filtered, washed, and dried to obtain a zirconium phosphate-benzotriazole composite ultraviolet absorber.

[0043] ②Prepare auxiliary materials: A blocked polyisocyanate curing agent, wherein the blocked polyisocyanate curing agent uses ε-caprolactam as a blocking agent, and the unblocking temperature of the blocked polyisocyanate curing agent is 135°C; An adhesion promoter, wherein the adhesion promoter is a copolymer of γ-(2,3-epoxypropoxy)propyltrimethoxysilane and glycidyl methacrylate; The rheology modifier is a compound of a hydrophobic modified alkali-swellable emulsion and a polyurethane associative thickener in a mass ratio of 2:1. Deionized water; Nano zinc oxide, wherein the particle size of the nano zinc oxide is 20-50 nm; Polyether-modified polydimethylsiloxane defoamer; A compound preservative of 2-methyl-4-isothiazolin-3-one and 5-chloro-2-methyl-4-isothiazolin-3-one; ③ Mixed coatings: Weigh out 50 parts of ordinary acrylic emulsion, 12 parts of hydroxyapatite-graphene composite filler, 6.5 parts of fluorosilane-modified nano titanium dioxide, 4 parts of zirconium phosphate-benzotriazole composite ultraviolet absorber, 3 parts of blocked polyisocyanate, 2 parts of adhesion promoter (γ-GPTMS-glycidyl methacrylate copolymer), 1.2 parts of rheology modifier (hydrophobic alkali swelling emulsion: polyurethane thickener = 2:1), 1.2 parts of nano zinc oxide, 2 parts of polyether-modified siloxane defoamer, 1.2 parts of compound preservative (2-methyl-4-isothiazolin-3-one: 5-chloro-2-methyl-4-isothiazolin-3-one = 3:1), and 22 parts of deionized water; After being evenly dispersed, it is coated onto cold-rolled steel sheet and cured at 140℃ for 20 minutes.

[0044] Comparative Example 2: The composite filler was replaced with a physically mixed hydroxyapatite + graphene (mass ratio 1:1) instead of the three-dimensional network composite filler.

[0045] Comparative Example 3: The zirconium phosphate intercalation structure was removed, and free benzotriazole (unintercalated) was used to replace the composite ultraviolet absorber.

[0046] Comparative Example 4: The modified component was removed, and unmodified nano-TiO2 was used to replace the fluorosilane-modified TiO2. The rest was the same as in Example 3.

[0047] Performance testing and data analysis Test methods Adhesion: GB / T9286-2021 (cross-cut test, grade 0 is optimal, cross-cut spacing 1mm, 3M tape peel).

[0048] Salt spray resistance: GB / T1771-2007 (scratch spread width after 500h, 5% NaCl, 35℃).

[0049] UV aging: GB / T23987-2019 (UVA-340 lamp, 0.76W / m², 1000h).

[0050] Contact angle: JC / T2000-2009 (static water contact angle, >90° is hydrophobic).

[0051] Wear resistance: GB / T1768-2006 (CS-10 grinding wheel, 1kg load, 1000 rpm).

[0052] The test results are as follows: Data annotation: Salt spray erosion width measurement: average value on both sides of the scratch (initial scratch length 50mm). ΔE value was measured using the HunterLab system (D65 light source); Comparative Example 3 showed a significant increase in color difference due to the migration of ultraviolet absorbers; Data Analysis: Example 3 achieved optimal performance in key indicators such as adhesion, corrosion resistance, weather resistance, and abrasion resistance. After 500 hours of salt spray testing, the scratch penetration width was only 0.5 mm, far below the 2 mm threshold for industrial anti-corrosion coatings. After 1000 hours of UV aging, the color difference ΔE remained stable within 0.9, exceeding the stringent standard of ΔE < 2.0 for automotive topcoats. It also possessed a superhydrophobic surface with a 108° angle and a low abrasion loss of 15 mg. These properties are not simply the sum of a single component, but rather stem from the synergistic effect of the following innovative design. The fluorine-silicon synergistic effect of the core-shell emulsion is the cornerstone of the coating performance. The fluorine-containing core layer (-CF3 groups) imparts hydrophobicity by reducing surface energy, while the organosilicon shell layer (Si-O-Si network) enhances the crosslinking density. The combination of these two elements increases the contact angle to 108° (compared to only 75° for the ordinary emulsion in Comparative Example 1), and significantly improves abrasion resistance (15 mg weight loss in Example 3 vs. 42 mg in Comparative Example 1). The organosilicon shell (Si-O-Si network) enhances the overall crosslinking density of the coating. The silicon-oxygen bonds (Si-O) in the organosilicon segments have high bond energies (452 ​​kJ / mol), far exceeding those of carbon-carbon bonds (CC, 347 kJ / mol). During film formation, they can form a three-dimensional network structure through the condensation reaction of silanol groups (-SiOH), resulting in tighter connections between molecular chains and thus increasing the crosslinking density of the coating. This high-density crosslinking structure effectively blocks water molecule penetration while improving the coating's temperature resistance and mechanical strength.

[0053] It should be noted that the fluorinated core layer and the organosilicon shell layer exhibit a complementary relationship and synergistic mechanism. The -CF3 groups in the fluorinated core layer have extremely low surface energy (approximately 16 mN / m), allowing them to migrate to and accumulate on the coating surface, thus imparting basic hydrophobicity to the coating. The Si-O-Si network of the organosilicon shell further reduces the contact area between water molecules and the coating surface through steric hindrance. Together, these two elements increase the contact angle from 75° in traditional coatings to over 108°, resulting in a significant enhancement of hydrophobic properties. The fluorinated groups have high UV reflectivity, reducing UV damage to the coating's interior. The Si-O bonds in the organosilicon exhibit strong UV aging resistance, protecting the molecular chains from breakage. This combination extends the QUV aging life of the coating by more than three times. The core-shell structure, through chemical bonding, such as the copolymerization of the core layer acrylate and the shell organosilicon, solves the compatibility problem of direct fluorine-silicon blending, avoiding phase separation and coating stickiness defects that occur in traditional fluorine-silicon modification. The topological strengthening mechanism of the three-dimensional composite filler is achieved through the chemical bonding between hydroxyapatite nanowires and graphene to form a three-dimensional barrier (comparative example 2, a physically mixed filler). This not only blocks water and oxygen penetration (reducing salt spray corrosion by 60%), but also inhibits coating cracking through the mechanical interlocking effect of the nanowires, thus improving wear resistance by 57%. The zirconium phosphate intercalation slow-release system solves the problem of easy migration of traditional ultraviolet absorbers (comparative example 3): benzotriazole molecules are locked between zirconium phosphate layers, and after 1000 hours of ultraviolet aging, the effective component residue rate is as high as 92.3% (compared to only 41.7% for the free form), which is the key reason for the low ΔE value of 0.9. The directional surface enrichment of fluorosilane-modified nano-TiO2 further strengthens the hydrophobic anti-corrosion network, increasing the contact angle by 36° compared to comparative example 4 (unmodified TiO2).

[0054] Of particular note is that the aforementioned components generated unexpected comprehensive benefits through multiple synergistic pathways. First, the interfacial coupling between the core-shell emulsion and the composite filler allows the coating to achieve a 3H pencil hardness at a low-temperature curing temperature of 140℃, while traditional anti-corrosion coatings require temperatures above 180℃, significantly expanding its application space on heat-sensitive metal substrates (such as aluminum alloys). Second, the combination of slow-release UV absorbers and hydrophobically modified TiO2 achieves both heavy-duty corrosion protection and high weather resistance while maintaining environmental protection standards of VOC ≤ 50g / L, with salt spray protection improved by 300% and ΔE reduced by 76%, breaking through the dilemma of water-based coatings being unable to coexist in terms of high environmental protection, good protective performance, and long service life. Third, the synergistic effect of the three-dimensional network filler and the organosilicon shell allows the coating to maintain an intact protective barrier after mechanical wear, increasing the expected service life by more than 2 times.

[0055] In summary, the core value of this invention lies in the deep coupling of core-shell / intercalation molecular structure design and fluorosilane modification / three-dimensional composite interface engineering, which comprehensively enhances the overall performance of the coating. At the technical level, it achieves three major breakthroughs: low-temperature curing to meet heavy-duty corrosion protection standards, an environmentally friendly system with ultra-long-lasting weather resistance, and a balance between mechanical stability and functional durability, providing a revolutionary solution for metal protection.

[0056] It is worth noting that the fluorine-silicon synergy of the core-shell emulsion forms a dense barrier, which improves the coating's salt spray resistance by 600% (only 0.5mm of corrosion diffusion after 500h) and UV aging stability by 300% (color difference ΔE≤0.9 after 1000h), far exceeding the heavy-duty anti-corrosion standard.

[0057] The composite filler imparts a 108° superhydrophobic surface and 3H high hardness to the coating, doubling its wear resistance life (15mg wear vs. 42mg for traditional coatings), and achieving the highest adhesion rating of 0. The 140℃ low-temperature curing process is suitable for heat-sensitive substrates, reducing energy consumption by 22%. The water-based system has VOCs ≤50g / L, achieving the protective performance of solvent-based coatings with green technology. Zirconium phosphate intercalation enables the slow release of UV absorbers, achieving a 92.3% residue rate after 1000 hours. Fluorosilane-modified TiO2 is directionally enriched to form a dynamic hydrophobic network, allowing the composite filler to self-repair micro-defects after wear.

[0058] Comparative Example 5: Based on Example 3, all three new functional components were removed, namely, hyperbranched polyester modified nano-silica, rare earth doped strontium aluminate long afterglow luminescent material, and polydopamine modified boron nitride nanosheets were not added. The remaining components and preparation process were exactly the same as in Example 3.

[0059] Comparative Example 6: Based on Example 3, only 4 parts of hyperbranched polyester modified nano-silica were added, and the rare earth-doped strontium aluminate long afterglow luminescent material and polydopamine-modified boron nitride nanosheets were removed. The remaining components and preparation process were exactly the same as in Example 3.

[0060] Comparative Example 7: Based on Example 3, only 3 parts of rare earth-doped strontium aluminate long afterglow luminescent material were added, and hyperbranched polyester-modified nano-silica and polydopamine-modified boron nitride nanosheets were removed. The remaining components and preparation process were exactly the same as in Example 3.

[0061] Comparative Example 8: Based on Example 3, only 2 parts of polydopamine-modified boron nitride nanosheets were added, and the hyperbranched polyester-modified nano-silica and rare earth-doped strontium aluminate long afterglow luminescent material were removed. The remaining components and preparation process were exactly the same as in Example 3.

[0062] Performance testing and data analysis Test methods Adhesion: GB / T9286-2021 (cross-cut test, grade 0 is optimal, cross-cut spacing 1mm, 3M tape peel).

[0063] Salt spray resistance: GB / T1771-2007 (scratch spread width after 500h, 5% NaCl, 35℃).

[0064] UV aging: GB / T23987-2019 (UVA-340 lamp, 0.76W / m 2 ,1000h).

[0065] Contact angle: JC / T2000-2009 (static water contact angle, >90° is hydrophobic).

[0066] Wear resistance: GB / T1768-2006 (CS-10 grinding wheel, 1kg load, 1000 rpm).

[0067] The test results are shown in the table below: Data annotation: Afterglow brightness is the surface brightness of the coating immediately after the light source is turned off following 1 minute of exposure to a standard ultraviolet lamp.

[0068] Afterglow time, brightness decays to 0.32 mcd / m 2 The time required for the human eye to discern the threshold in a dark environment.

[0069] Experimental conclusions Comparative Example 5 showed significantly worse performance than Example 3 in all aspects, demonstrating that the three newly added components played a decisive role in improving the overall performance of the coating. Comparative Example 6 showed improvements in adhesion, abrasion resistance (21 mg), and hydrophobicity (102°), but limited improvements in salt spray resistance (1.5 mm) and UV resistance (ΔE 1.8), and had no luminescent function. Comparative Example 7 provided luminescent function, but due to its generally poor compatibility with the substrate, its contribution to mechanical properties (adhesion grade 1, abrasion resistance 30 mg), barrier properties (salt spray 1.8 mm), and hydrophobicity (90°) was weak. Comparative Example 8 showed outstanding performance in salt spray resistance (0.8 mm), adhesion (Grade 0), and hydrophobicity (105°), but its improvement in UV resistance (ΔE 1.6) was not as good as Example 3, and it had no luminescent function. Its improvement in abrasion resistance (18 mg) was also not as good as the synergistic effect of the three components (15 mg): hyperbranched polyester modified nano-silica, rare earth doped strontium aluminate long afterglow luminescent material, and polydopamine modified boron nitride nanosheets.

[0070] Example 3's performance data is not a simple summation of the data from the three comparative examples 6, 7, and 8, but rather it achieves optimal performance across all key indicators. This indicates a synergistic effect among the three components. The hyperbranched polyester SiO2 and the polydopamine-modified boron nitride nanosheets work together to significantly improve the coating's density, hardness, and abrasion resistance by enhancing crosslinking density and interfacial bonding, and further reduce water and oxygen permeability (0.5 mm in salt spray).

[0071] The excellent barrier properties of polydopamine-modified boron nitride nanosheets, combined with the improved dispersibility and compatibility of hyperbranched polyester SiO2, provide a stable and durable host environment for the luminescent material, ensuring its luminescence performance and weather resistance remain unaffected. The presence of the luminescent material does not impair the mechanical and protective properties of the coating, demonstrating its excellent integration through silicate encapsulation and composite systems. The hyperbranched polyester-modified nano-silica, rare-earth-doped strontium aluminate long-afterglow luminescent material, and polydopamine-modified boron nitride nanosheets work synergistically to achieve a comprehensive effect unattainable by single or dual-component systems, including high adhesion, extreme corrosion resistance, superior weather resistance, superhydrophobicity, high abrasion resistance, and long-lasting luminescence.

[0072] This invention breaks through the industry dilemma of water-based coatings being difficult to reconcile with high environmental protection, good protective performance, and long lifespan. Its core benefit lies in achieving excellent corrosion resistance, strong weather resistance, low energy consumption, and wide applicability simultaneously with a single coating system, providing a coating solution with revolutionary performance and green features for high-end fields such as new energy vehicles and marine equipment.

[0073] The above specific embodiments are merely several optional embodiments of the present invention. Based on the technical solutions of the present invention and the relevant teachings of the above embodiments, those skilled in the art can make various alternative improvements and combinations to the above specific embodiments.

Claims

1. A multifunctional waterborne acrylic coating composition, characterized in that, Including the following parts by weight of raw materials: 40-60 parts of a core-shell structured acrylate emulsion, wherein the core layer of the core-shell structured acrylate emulsion is a fluorinated acrylate copolymer, and the shell layer is an organosilicon-modified acrylate copolymer; 10-15 parts of hydroxyapatite-graphene composite filler; 5-8 parts of fluorosilane-modified nano-titanium dioxide; 3-5 parts of zirconium phosphate-benzotriazole composite ultraviolet absorber; 2-4 parts of a blocked polyisocyanate curing agent, wherein the blocked polyisocyanate curing agent uses ε-caprolactam as a blocking agent, and the unblocking temperature of the blocked polyisocyanate curing agent is 120-140℃; 1-3 parts of adhesion promoter, wherein the adhesion promoter is a copolymer of γ-(2,3-epoxypropoxy)propyltrimethoxysilane and glycidyl methacrylate; 0.5-2 parts of rheology modifier, wherein the rheology modifier is a compound of hydrophobic modified alkali-swellable emulsion and polyurethane associative thickener in a mass ratio of 2:1; 3-5 parts of hyperbranched polyester-modified nano-silica were prepared by modifying nano-silica with 3-aminopropyltriethoxysilane to obtain amino-functionalized nano-silica, reacting dimethylolpropionic acid with pentaerythritol under p-toluenesulfonic acid catalysis and nitrogen protection to obtain hydroxyl-terminated hyperbranched polyester, and reacting the two with 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, followed by post-treatment; 2-4 parts of rare earth-doped strontium aluminate long-afterglow luminescent material were prepared by using strontium nitrate, aluminum chloride, europium nitrate, dysprosium nitrate, and boric acid via sol-gel method and high-temperature calcination to obtain europium and dysprosium co-doped strontium aluminate, which was then coated with sodium silicate and calcined; 1-3 parts of polydopamine-modified boron nitride nanosheets were also prepared. The preparation method involves ultrasonically dispersing boron nitride nanosheets, reacting them with dopamine hydrochloride in a tris(hydroxymethyl)aminomethane buffer solution, and then undergoing post-treatment. 15-30 parts deionized water.

2. The multifunctional waterborne acrylic coating composition according to claim 1, characterized in that, The preparation method of the core-shell structured acrylate emulsion includes: Add 20-30 parts of methyl methacrylate, 10-20 parts of butyl acrylate, 5-10 parts of trifluoroethyl methacrylate, 2-3 parts of acrylic acid, 0.2-0.5 parts of ammonium persulfate initiator, and 0.5-1 parts of sodium dodecylbenzenesulfonate emulsifier to the reaction vessel and react at 75-85℃ for 3-4 hours. Add dropwise a mixture consisting of 15-25 parts methyl methacrylate, 10-15 parts ethyl acrylate, 5-10 parts γ-methacryloyloxypropyltrimethoxysilane, and 0.1-0.3 parts ammonium persulfate as an initiator, and react at 80-90℃ for 2-3 hours. After the reaction is complete, the temperature is lowered to 40-50℃, and ammonia is added to adjust the pH to 7-8 to obtain a core-shell structured acrylate emulsion.

3. The multifunctional waterborne acrylic coating composition according to claim 1, characterized in that, The preparation method of the hydroxyapatite-graphene composite filler includes: Graphene oxide is dispersed in deionized water and ultrasonically treated for 30-60 minutes to form a graphene oxide dispersion with a concentration of 0.5-2 mg / mL. Calcium nitrate and ammonium dihydrogen phosphate were added to the graphene oxide dispersion, with a calcium-to-phosphorus molar ratio of 1.67, and the mixture was stirred until homogeneous. Under stirring, slowly add ammonia water to adjust the pH value to 9-10, and then react at 80-90℃ for 6-12 hours; After the reaction is complete, the mixture is cooled to room temperature, filtered, washed, and dried. Then, it is calcined at 400-500℃ for 2-3 hours under a nitrogen atmosphere to obtain the hydroxyapatite-graphene composite filler.

4. The multifunctional waterborne acrylic coating composition according to claim 1, characterized in that, The preparation method of the fluorosilane-modified nano-titanium dioxide includes: Nano-titanium dioxide is dispersed in anhydrous ethanol and ultrasonically treated for 30-60 minutes to form a nano-titanium dioxide dispersion with a concentration of 5-10 wt%. 3-(perfluorooctyl)propyltrimethoxysilane was added to the nano-titanium dioxide dispersion, with a mass ratio of nano-titanium dioxide to 3-(perfluorooctyl)propyltrimethoxysilane of 10:1-5, and the mixture was stirred until homogeneous. The reaction was refluxed at 60-80℃ for 6-12 hours. After the reaction was completed, the mixture was cooled to room temperature, filtered, washed, and dried to obtain fluorosilane-modified nano-titanium dioxide.

5. The multifunctional waterborne acrylic coating composition according to claim 1, characterized in that, The preparation method of the zirconium phosphate-benzotriazole composite ultraviolet absorber includes: Zirconium phosphate was dispersed in deionized water and ultrasonically treated for 30-60 minutes to form a zirconium phosphate dispersion with a concentration of 1-5 wt%. Add a benzotriazole UV absorber to the zirconium phosphate dispersion, wherein the mass ratio of zirconium phosphate to benzotriazole UV absorber is 1:0.2-0.5, and stir until homogeneous; The reaction was carried out at 50-70℃ for 8-16 hours. After the reaction was completed, the mixture was cooled to room temperature, filtered, washed, and dried to obtain the zirconium phosphate-benzotriazole composite ultraviolet absorber.

6. The multifunctional waterborne acrylic coating composition according to claim 1, characterized in that, It also includes 0.5-2 parts of nano zinc oxide, wherein the nano zinc oxide has a particle size of 20-50 nm.

7. The multifunctional waterborne acrylic coating composition according to claim 1, characterized in that, It also includes 1-3 parts of polyether-modified polydimethylsiloxane defoamer.

8. The multifunctional waterborne acrylic coating composition according to claim 1, characterized in that, It also includes 0.5-2 parts of a compound preservative of 2-methyl-4-isothiazolin-3-one and 5-chloro-2-methyl-4-isothiazolin-3-one.

9. The multifunctional waterborne acrylic coating composition according to claim 1, characterized in that, The multifunctional waterborne acrylic coating composition consists of a separately stored liquid phase and a functional phase, and the preparation method is as follows: The preparation of the liquid phase involves first aging the core-shell structured acrylate emulsion at a low temperature of 5-10℃ for 12-24 hours, then slowly heating it to 40±2℃ at a speed of 200-500 r / min under nitrogen protection, and stirring at a constant temperature for 30-45 minutes. Subsequently, an adhesion promoter, a rheology modifier, and deionized water are added, and the mixture is ground online 3-5 times using a three-roll mill with the grinding gap controlled at 10-15 μm. Finally, the pH value of the system is precisely adjusted to 7.8-8.2 using an organic amine pH adjuster to obtain the liquid phase. The functional phase was prepared by first pretreating hydroxyapatite-graphene composite filler, fluorosilane-modified nano-titanium dioxide, zirconium phosphate-benzotriazole composite ultraviolet absorber, blocked polyisocyanate curing agent, hyperbranched polyester-modified nano-silica, rare earth-doped strontium aluminate long afterglow luminescent material, and polydopamine-modified boron nitride nanosheets in an ultrasonic field at a frequency of 40 kHz and a power of 800 W for 20-30 minutes. Then, the mixture was transferred to a microwave reactor and irradiated for 5-8 minutes at a power of 600 W and a temperature of 60 ± 5 ℃. Subsequently, a blocked polyisocyanate curing agent with bisulfite as a blocking agent was added, and the mixture was stirred at high speed under a vacuum of -0.08 to -0.10 MPa and a rotation speed of 800-1000 r / min. At the same time, cooling water was introduced to keep the system temperature below 35 ℃ until a uniform paste with a particle size D50 ≤ 15 μm was formed, thus obtaining the functional phase. The system employs a dual-channel dynamic impact mixing technology, where the liquid phase and functional phase are respectively injected into the mixing chamber in jet form through two channels with an inner diameter ratio of 3:1, under conditions of pressure 0.4-0.6MPa and temperature 25-30℃. The two liquid streams collide at high speed at a 120° angle, generating an instantaneous shear rate as high as 10. 4 -10 5 s -1 To achieve the turbulent mixing effect, the mixing time is controlled between 90 and 120 seconds to obtain a mixed coating. The mixed coating is immediately passed through a processing pipe equipped with rare earth permanent magnets and oriented under a magnetic field strength of 0.3-0.5T for 60-90 seconds. Finally, it is left to stand and mature for 20-30 minutes in the dark.

10. The application of a multifunctional waterborne acrylic coating composition as described in any one of claims 1-9, characterized in that, Used as an anti-corrosion coating for metal surfaces.

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