Preparation method and application of a marine static antifouling coating

Abstract

This invention relates to the field of chemical coatings, specifically to a method for preparing and applying a marine static antifouling coating. It addresses the environmental pollution risks and static antifouling failure issues of traditional copper-containing antifouling coatings. The coating constructs a coating with a synergistic effect of a triple antifouling mechanism—low surface energy fouling release, contact antibacterial repellency, and intrinsic self-healing—by synergistically introducing a fluorinated antibacterial gel and a hindered urea bond crosslinking agent into an aqueous polyurethane system. The fluorinated antibacterial gel's fluorinated shell provides low surface energy fouling release, while the quaternary ammonium salt core provides contact antibacterial function. A nanogel with a fluorinated chain segment shell and a quaternary ammonium salt polymer core is prepared through polymerization-induced self-assembly. When cracks appear in the coating, the polymer chain segments at the crack interface exhibit a thermodynamic driving force for re-entanglement due to entropy elasticity. The hindered urea bonds undergo dynamic exchange reactions, prompting the molecular chains to re-bond across the crack interface, achieving healing and preventing seawater and fouling organisms from invading along the defects.

Description

Technical Field

[0001] This invention relates to the field of chemical coatings, specifically to a method for preparing and applying a marine static antifouling coating. Background Technology

[0002] Currently, commercial marine antifouling coatings mainly use cuprous oxide as the primary antifouling agent. Cuprous oxide kills attached organisms by releasing copper ions, and has the advantages of broad-spectrum and high efficiency.

[0003] However, traditional copper-containing antifouling coatings have two core drawbacks: environmental pollution risks and static antifouling failure. High doses of copper ion release have toxic effects on marine ecosystems, and copper ions accumulate in sediments in ports and bays, disrupting the ecological balance. In static environments such as ship berthing or marine ranches, the poor flow of seawater and the unstable leaching rate of cuprous oxide can easily lead to the rapid loss of antifouling agents and a decline in antifouling ability in the later stages.

[0004] Therefore, the preparation method and application of the marine static antifouling coating of the present invention are of great significance in the field of chemical coatings. Summary of the Invention

[0005] In order to overcome the above-mentioned technical problems, the purpose of this invention is to provide a method for preparing and applying a marine static antifouling coating, which solves the problems of environmental pollution risk and static antifouling failure of traditional copper-containing antifouling coatings.

[0006] The objective of this invention can be achieved through the following technical solutions: In a first aspect, this application provides a method for preparing a marine static antifouling coating, comprising the following steps: Step 1: Weigh out the following components by weight: 5-25 parts fluorinated antibacterial gel, 5-15 parts pigment, 30-50 parts polytetrahydrofuran glycol, 15-25 parts polyisocyanate, 2-8 parts hindered urea crosslinking agent, 0.5-1.5 parts dispersant, 0.2-0.5 parts defoamer, 0.5-2 parts anti-settling agent, 3-8 parts chain extender, 0.05-0.1 parts catalyst, 3-6 parts neutralizer, 1-3 parts post-chain extender aqueous solution, 8-12 parts curing agent, 10-20 parts acetone, and 80-120 parts deionized water. Step 2: Polytetrahydrofuran diol is added to a reactor equipped with a stirrer, thermometer, and nitrogen protection. It is dehydrated at 110℃ and -0.09MPa vacuum for 1 hour, then cooled to 70℃. Polyisocyanate and catalyst are added, and the mixture is stirred at 70℃ and 300 rpm for 2-3 hours. A chain extender is added, and the reaction continues for 1-2 hours. A hindered urea crosslinking agent is then added, and the reaction continues for 2 hours. Acetone is added, and the mixture is stirred for 30 minutes. The temperature is lowered to 40℃, and a neutralizing agent is added. The mixture is stirred for 30 minutes to obtain a prepolymer. The prepolymer is added to a disperser, and deionized water is added at 1500-2000 rpm for reverse emulsification. A chain extender aqueous solution is added dropwise, and the mixture is stirred for another 30 minutes. The mixture is then distilled under reduced pressure at 50℃ and -0.09MPa to obtain a self-healing waterborne polyurethane dispersion. Step 3: Mix the dispersant, defoamer, and antisettling agent at 500-800 rpm for 1-2 hours. Add the pigment and disperse at 1000 rpm for 20-30 minutes. Transfer the mixture to a sand mill and grind it to a fineness of ≤20 μm. Add the fluorinated antibacterial gel and stir at 400 rpm for 30 minutes. Add the self-healing waterborne polyurethane dispersion and stir at 600 rpm for 15-20 minutes. Add the curing agent and continue stirring for 5-10 minutes to obtain the marine static antifouling coating.

[0007] In a preferred embodiment of the present invention, the pigment is composed of iron oxide red and barium sulfate mixed in a mass ratio of 5-10:10-15; the polytetrahydrofuran diol is PTMG-2000; the dispersant is BYK-190; the defoamer is BYK-028; the anti-settling agent is AEROSIL 200; the chain extender is 2,2-dimethylolpropionic acid; the catalyst is dibutyltin dilaurate; the neutralizing agent is triethylamine; the mass fraction of the post-chain extender aqueous solution is 40%, and the solute is ethylenediamine; the curing agent is Bayhydur® quix ultra 306-70.

[0008] In a preferred embodiment of the present invention, the fluorinated antibacterial gel is prepared by the following steps: Step a1: Add the dithioester chain transfer agent, fluorinated acrylate monomer, initiator, and anhydrous 1,4-dioxane to a Schrank flask equipped with a stirrer, a spherical condenser, and a nitrogen delivery tube. Purge with nitrogen for 30 min to remove oxygen. Immerse the Schrank flask in a constant temperature oil bath at 70°C and react with magnetic stirring at 300 r / min for 24 h under nitrogen protection. After the reaction is complete, allow it to cool naturally to 25°C. Add it to cold n-hexane to precipitate, filter, wash the precipitate 2-3 times with distilled water, and dry it in a vacuum drying oven at 40°C for 5-6 h to obtain the reactive stabilizer. Step a2: Add the reactive stabilizer, quaternary ammonium salt monomer, crosslinking agent, and mixed solvent to a three-necked flask equipped with a stirrer and thermometer. Mix and stir for 10-15 min, then purge with nitrogen for 30 min to degas. Add the initiator, heat to 70℃ under nitrogen protection, and mix and stir at 200 r / min for 12 h to obtain a core-shell nanogel emulsion. Add the core-shell nanogel emulsion, photoinitiator, glycidyl methacrylate, and deionized water to a photochemical reactor. Purge with nitrogen at 25℃ for 15-20 min to remove oxygen. Perform the reaction at 365 nm and 5 mW / cm². 2 The mixture was stirred and reacted under ultraviolet light for 2 hours. An inhibitor and acrylic acid were added, and the mixture was heated to 90°C and reacted at a constant temperature for 5-6 hours under nitrogen protection. After the reaction was completed, the mixture was naturally cooled to 25°C and dialyzed for 72 hours using a dialysis bag with a molecular weight cutoff of 14000 Da to obtain a fluorinated antibacterial gel.

[0009] In a preferred embodiment of the present invention, the ratio of the dithioester chain transfer agent, the fluorinated acrylate monomer, the initiator, anhydrous 1,4-dioxane, and cold n-hexane in step a1 is 0.2-0.4g: 15-20mL: 0.03-0.04g: 30-50mL: 300mL; the dithioester chain transfer agent is 4-cyano-4-(thiobenzoyl)valerate; the fluorinated acrylate monomer is dodecafluoroheptyl methacrylate; and the initiator is azobisisobutyronitrile.

[0010] In a preferred embodiment of the present invention, the ratio of the reactive stabilizer, quaternary ammonium salt monomer, crosslinking agent, mixed solvent, initiator, photoinitiator, glycidyl methacrylate, deionized water, polymerization inhibitor, and acrylic acid in step a2 is 1-2g:10-15mL:1-1.5mL:100-150mL:0.08-0.1g:0.08-0.1g:2-3g:100mL:0.02g:3-4g; the quaternary ammonium salt monomer is methacryloyloxyethyltrimethylammonium chloride; the crosslinking agent is ethylene glycol dimethacrylate; the mixed solvent is a 20% (w / w) ethanol solution; the initiator is azobiscyanopentanoic acid; the photoinitiator is photoinitiator 819; and the polymerization inhibitor is hydroquinone.

[0011] In a preferred embodiment of the present invention, the hindered urea bond crosslinking agent is prepared by the following steps: Step b1: Add triphosgene and the first part of tetrahydrofuran to a three-necked flask equipped with a stirrer, thermometer, and constant pressure funnel, and mix and stir for 30 min; add tert-butylamine, acid-binding agent, and the second part of tetrahydrofuran to a beaker, mix and stir for 30 min, transfer to a constant pressure funnel, and add dropwise to the above three-necked flask at 0℃ at a rate of 1-2 mL / min, stir and react at 0℃ for 1 h, add 1,3-diamino-2-propanol and the third part of tetrahydrofuran, stir and react at 25℃ and nitrogen protection at a speed of 300 r / min for 12 h, filter, concentrate the filtrate by rotary evaporation at 40℃, add eluent, purify by silica gel column chromatography, and vacuum dry at 40℃ for 3-5 h to obtain the precursor; Step b2: Low molecular weight polyethylene glycol is added to a three-necked flask equipped with a stirrer and thermometer. The mixture is vacuum-stirred and dehydrated at 110°C and -0.09 MPa for 1-2 hours. Nitrogen gas is then introduced for protection, and the mixture is cooled to 70°C. Isophorone diisocyanate and a catalyst are added, and the mixture is stirred at 70°C and 300 r / min for 2-3 hours to obtain the NCO-terminated prepolymer. The precursor and the first portion of N,N-dimethylformamide are added to the reactor, and nitrogen gas is introduced for protection. The mixture is then stirred at 40°C. Stir at ℃ for 30 min; mix and stir the NCO-terminated prepolymer and the second part of N,N-dimethylformamide for 30 min, transfer to a constant pressure funnel, and add dropwise to the above reactor at 40℃ at a rate of 1-2 mL / min. Stir the reaction at 300 r / min for 4-5 h, cool naturally to 25℃, add to cold diethyl ether to precipitate for 1-2 h, filter, wash the precipitate 2-3 times with distilled water, and vacuum dry at 35℃ for 24 h to obtain the hindered urea bond crosslinking agent.

[0012] In a preferred embodiment of the present invention, the ratio of triphosgene, total tetrahydrofuran, tert-butylamine, acid-binding agent, 1,3-diamino-2-propanol, and eluent in step b1 is 8-10g: 180-240mL: 7-7.5g: 10-13g: 2-3g: 200-300mL; the first part of tetrahydrofuran accounts for 2 / 3 of the total tetrahydrofuran; the second part of tetrahydrofuran accounts for 2 / 9 of the total tetrahydrofuran; the third part of tetrahydrofuran accounts for 1 / 9 of the total tetrahydrofuran; the acid-binding agent is N,N-diisopropylethylamine; and the eluent is a mixture of dichloromethane and methanol at a volume ratio of 20:1.

[0013] In a preferred embodiment of the present invention, the total amount of low molecular weight polyethylene glycol, isophorone diisocyanate, catalyst, precursor, N,N-dimethylformamide, and cold diethyl ether in step b2 is 40-45g:48-55g:0.05g:5-6g:80-100mL:800mL; the type of low molecular weight polyethylene glycol is PEG-400; the catalyst is dibutyltin dilaurate; the first part of N,N-dimethylformamide accounts for 1 / 2 of the total amount of N,N-dimethylformamide; the second part of N,N-dimethylformamide accounts for 1 / 2 of the total amount of N,N-dimethylformamide.

[0014] Secondly, this application provides an application of a marine static antifouling coating on the surface of marine facilities.

[0015] The beneficial effects of this invention are: This invention discloses a method for preparing and applying a marine static antifouling coating. Polytetrahydrofuran glycol is vacuum dehydrated, then polyisocyanate and a catalyst are added and stirred. A chain extender is added and the reaction continues. A hindered urea crosslinking agent is then added and reacted. Acetone is added and mixed. A neutralizing agent is added and stirred to obtain a prepolymer. The prepolymer is added to a disperser, and deionized water is added for reverse emulsification. A chain extender aqueous solution is added dropwise and stirred. The mixture is then distilled under reduced pressure to obtain a self-healing waterborne polyurethane dispersion. A dispersant, defoamer, anti-settling agent, and deionized water are mixed and stirred. Pigment is added and dispersed, and the mixture is ground. Fluorinated antibacterial gel is added and stirred. The self-healing waterborne polyurethane dispersion is added and stirred. A curing agent is added and stirred to obtain the marine static antifouling coating. By synergistically introducing the fluorinated antibacterial gel and the hindered urea crosslinking agent into the waterborne polyurethane system, a low surface energy is achieved. The fluorinated antifouling gel employs a synergistic triple antifouling mechanism of fouling release, contact antibacterial repellency, and intrinsic self-healing. Fluorinated segments in the gel spontaneously accumulate on the surface during coating film formation, creating a low-surface-energy anti-adhesion interface that makes it difficult for fouling organisms to adhere, resulting in excellent static antifouling performance. Hindered urea crosslinking agents construct dynamic reversible crosslinking points within the polymer network. When cracks or scratches occur on the coating surface, the hindered urea bonds undergo dynamic exchange reactions, prompting molecular chains to re-bond across the crack interface, achieving self-healing. The fluorinated antifouling gel is covalently crosslinked within the three-dimensional coating network via surface-polymerizable double bonds, chemically anchoring the low-surface-energy fluorinated components and quaternary ammonium salt antibacterial components, resulting in stable antifouling performance. The coating formulation is free of cuprous oxide, organotin compounds, and other heavy metal biocides, aligning with the development direction of green marine coatings.

[0016] In the preparation of marine static antifouling coatings, a fluorinated antibacterial gel was first prepared. Under heating conditions, the initiator decomposed to generate free radicals, initiating the polymerization of fluorinated acrylate monomers. A dithioester chain transfer agent, through its C=S double bond, underwent a reversible addition-fracture reaction with the free radicals to obtain a fluorinated reactive stabilizer with retained active dithioester end groups. The fluorocarbon side chains of the fluorinated acrylate monomers have low surface free energy, allowing fluorinated segments to spontaneously migrate and accumulate towards the air interface during coating film formation, endowing the coating with excellent fouling release properties and making it difficult for fouling organisms to adhere. The retained dithioester end groups participate in the polymerization-induced self-assembly process in the next step, anchoring the fluorinated segments to the nanogel shell in a covalent bond form, preventing migration and loss during service. Under heating conditions, the initiator decomposed to generate free radicals, which, under the chain transfer regulation of the reactive stabilizer, initiated a quaternary... Ammonium salt monomers undergo reversible addition-fragmentation chain transfer copolymerization with crosslinking agents. Quaternary ammonium salt copolymer segments grow and crosslink, transforming the system from a homogeneous solution into a self-assembled dispersion of block copolymers, forming a core-shell gel with a fluorinated segment as a stable shell and a crosslinked quaternary ammonium salt as the core. Under ultraviolet light irradiation, the photoinitiator decomposes to generate free radicals, and the ultraviolet light simultaneously causes photolytic cleavage of residual end groups on the surface of the nanogel. The resulting surface free radicals initiate the graft polymerization of glycidyl methacrylate on the particle surface. The carboxyl groups of acrylic acid attack the epoxy groups on the glycidyl methacrylate segments to undergo ring-opening esterification, covalently introducing polymerizable carbon-carbon double bonds into the outermost surface of the nanogel. After dialysis purification, a fluorinated antibacterial gel is obtained. The fluorinated shell of the gel provides low surface energy fouling release function, while the quaternary ammonium salt core provides contact antibacterial function.

[0017] In the preparation of marine static antifouling coatings, a hindered urea bond crosslinking agent was first prepared. Under low-temperature conditions, triphosgene lost one molecule of hydrogen chloride in the presence of an acid-binding agent, generating a phosgene intermediate. Phosgene reacted with tert-butylamine, where the amino group of tert-butylamine attacked the carbonyl carbon of phosgene. After passing through a tetrahedral intermediate, one molecule of hydrogen chloride was eliminated, generating tert-butyl isocyanate. The generated tert-butyl isocyanate underwent a nucleophilic addition reaction with the two amino groups of 1,3-diamino-2-propanol. The highly reactive carbon atom of the isocyanate group was attacked by the lone pair electrons of the nitrogen atom of the amino group, and after rearrangement, a urea bond was formed, bridging the two tert-butyl isocyanate molecules. The 1,3-diamino-2-propanol backbone retains the suspended hydroxyl groups on the backbone. After purification by silica gel column chromatography, the precursor is obtained. A tert-butyl group is introduced onto the nitrogen atom of the urea bond to weaken the formation of hydrogen bonds between urea bonds and lower the bond dissociation energy, allowing the hindered urea bond to undergo a dynamic exchange reaction at room temperature, providing the coating with self-healing capability. The retained suspended hydroxyl groups can undergo a coupling reaction with the NCO-terminated prepolymer in the next step, embedding the dynamic hindered urea bond core into the crosslinking agent molecule in the form of chemical bonds, ensuring the durability and stability of the self-healing function. Under the catalysis of a catalyst, the two terminal hydroxyl groups of low molecular weight polyethylene glycol react with isocyanate... The isocyanate group of phorone diisocyanate undergoes a nucleophilic addition reaction, with the oxygen atom of the hydroxyl group attacking the carbon atom of the isocyanate, resulting in a rearrangement to form a urethane bond, yielding an NCO-terminated prepolymer. The suspended hydroxyl group on the precursor molecule undergoes the same nucleophilic addition reaction with the NCO group at one end of the NCO-terminated prepolymer, forming a urethane bond. This covalently couples the NCO-terminated prepolymer to the hindered urea bond core of the precursor. Simultaneously, the secondary amine groups in the two hindered urea bonds on the precursor molecule can react with the NCO group of another prepolymer molecule, forming additional urea bond connection sites. After purification by ether precipitation, the desired product is obtained. The hindered urea bond crosslinking agent chemically embeds two dynamically hindered urea bonds into the core position of the crosslinking agent molecule. When this crosslinking agent is used to cure waterborne polyurethane coatings, the hindered urea bonds are uniformly distributed in the three-dimensional crosslinking network of the coating. When the coating is subjected to mechanical damage and microcracks are generated, the polymer chain segments at the crack interface have a thermodynamic driving force for re-entanglement due to entropy elasticity. The hindered urea bonds can undergo a dynamic exchange reaction at room temperature, which promotes the molecular chains to re-bond across the crack interface and achieve healing. The dynamic exchange of hindered urea bonds is a reversible chemical reaction, and the coating can be repaired multiple times at the same location, extending the service life of the coating. Detailed Implementation

[0018] To enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Example 1: This embodiment describes a method for preparing a marine static antifouling coating, comprising the following steps: Step S1: 0.2 g of 4-cyano-4-(thiobenzoyl)valerate, 15 mL of dodecafluoroheptyl methacrylate, 0.03 g of azobisisobutyronitrile, and 30 mL of anhydrous 1,4-dioxane were added to a Schrank flask equipped with a stirrer, a spherical condenser, and a nitrogen delivery tube. Nitrogen gas was bubbled through the flask for 30 min to remove oxygen. The Schrank flask was then immersed in a constant temperature oil bath at 70 °C and the mixture was magnetically stirred at 300 r / min for 24 h under nitrogen protection. After the reaction was completed, the mixture was allowed to cool naturally to 25 °C and added to 300 mL of cold n-hexane to precipitate the precipitate. The precipitate was filtered, washed twice with distilled water, and dried in a vacuum drying oven at 40 °C for 5 h to obtain the reactive stabilizer. Step S2: Add 1g of reactive stabilizer, 10mL of methacryloyloxyethyltrimethylammonium chloride, 1mL of ethylene glycol dimethacrylate, and 100mL of 20% ethanol solution to a three-necked flask equipped with a stirrer and thermometer. Mix and stir for 10min, then purge with nitrogen for 30min to degas. Add 0.08g of azodicyanovalerate, and heat to 70℃ under nitrogen protection. Mix and stir at 200r / min for 12h to obtain a core-shell nanogel emulsion. Add the core-shell nanogel emulsion, 0.08g of photoinitiator 819, 2g of glycidyl methacrylate, and 100mL of deionized water to a photochemical reactor. Purge with nitrogen at 25℃ for 15min to remove oxygen. Perform the reaction at 365nm and 5mW / cm². 2 The mixture was stirred under ultraviolet light for 2 hours, then 0.02 g hydroquinone and 3 g acrylic acid were added. Under nitrogen protection, the mixture was heated to 90°C and reacted at a constant temperature for 5 hours. After the reaction was completed, it was naturally cooled to 25°C and dialyzed for 72 hours using a dialysis bag with a molecular weight cutoff of 14000 Da to obtain a fluorinated antibacterial gel. Step S3: Add 8g of triphosgene and 120mL of precipitate to a three-necked flask equipped with a stirrer, thermometer, and constant pressure funnel, and mix and stir for 30min. Add 7g of tert-butylamine, 10g of N,N-diisopropylethylamine, and 40mL of tetrahydrofuran to a beaker, mix and stir for 30min, transfer to a constant pressure funnel, and add dropwise to the above three-necked flask at 0℃ at a rate of 1mL / min. Stir and react at 0℃ for 1h. Add 2g of 1,3-diamino-2-propanol and 20mL of tetrahydrofuran, and stir and react at 300r / min for 12h at 25℃ under nitrogen protection. Filter, concentrate the filtrate by rotary evaporation at 40℃, add 200mL of eluent, purify by silica gel column chromatography, and vacuum dry at 40℃ for 3h to obtain the precursor. The eluent is a mixture of dichloromethane and methanol in a volume ratio of 20:1. Step S4: Add 40g of low molecular weight polyethylene glycol PEG-400 to a three-necked flask equipped with a stirrer and thermometer. Vacuum stir and dehydrate at 110℃ and -0.09MPa for 1 hour. Purge with nitrogen for protection, cool to 70℃, add 48g of isophorone diisocyanate and 0.05g of dibutyltin dilaurate, and stir at 70℃ and 300r / min for 2 hours to obtain the NCO-terminated prepolymer. Add 5g of the precursor and 40mL of N,N-dimethylformamide to the reactor. Purge with nitrogen for protection and stir at 40℃ for 30 minutes. Add the NCO-terminated prepolymer and 40mL of... N,N-dimethylformamide was mixed and stirred for 30 min, then transferred to a constant pressure funnel and added dropwise to the reactor at 40 °C at a rate of 1 mL / min. The mixture was stirred at 300 r / min for 4 h, then naturally cooled to 25 °C. The mixture was added to 800 mL of cold diethyl ether to precipitate for 1 h, filtered, and the precipitate was washed twice with distilled water. The precipitate was then vacuum dried at 35 °C for 24 h to obtain the hindered urea crosslinking agent. Step S5: Weigh out the following components by weight: 5 parts fluorinated antibacterial gel, 5 parts pigment, 30 parts polytetrahydrofuran diol PTMG-2000, 15 parts polyisocyanate, 2 parts hindered urea crosslinking agent, 0.5 parts dispersant BYK-190, 0.2 parts defoamer BYK-028, 0.5 parts anti-settling agent AEROSIL 200, 3 parts 2,2-dimethylolpropionic acid, 0.05 parts dibutyltin dilaurate, 3 parts triethylamine, 1 part post-chain extender aqueous solution, 8 parts curing agent, 10 parts acetone, and 80 parts deionized water; the pigment is composed of iron oxide red and barium sulfate mixed in a mass ratio of 5:10; the post-chain extender aqueous solution has a mass fraction of 40%, and the solute is ethylenediamine; the curing agent is Bayhydur® quix ultra 306-70. Step S6: Add polytetrahydrofuran diol PTMG-2000 to a reactor equipped with a stirrer, thermometer, and nitrogen protection. Dehydrate under vacuum at 110℃ and -0.09MPa for 1 hour. Cool down to 70℃, add polyisocyanate and dibutyltin dilaurate, and stir for 2 hours at 70℃ and 300r / min. Add 2,2-dimethylolpropionic acid and continue the reaction for 1 hour. Add hindered urea crosslinking agent and react for 2 hours. Add acetone and mix and stir for 30 minutes. Cool down to 40℃, add triethylamine, and stir for 30 minutes to obtain a prepolymer. Add the prepolymer to a disperser and add deionized water at 1500r / min for reverse emulsification. Add the chain extender aqueous solution dropwise and continue stirring for 30 minutes. Distill under reduced pressure at 50℃ and -0.09MPa to obtain a self-healing waterborne polyurethane dispersion. Step S7: Mix dispersant BYK-190, defoamer BYK-028, and antisettling agent AEROSIL 200 at 500 r / min for 1 hour. Add pigment and disperse at 1000 r / min for 20 minutes. Transfer to a sand mill and grind to a fineness ≤20 μm. Add fluorinated antibacterial gel and stir at 400 r / min for 30 minutes. Add self-healing waterborne polyurethane dispersion and stir at 600 r / min for 15 minutes. Add curing agent and continue stirring for 5 minutes to obtain marine static antifouling coating.

[0020] Example 2: This embodiment describes a method for preparing a marine static antifouling coating, comprising the following steps: Step S1: 0.3g of 4-cyano-4-(thiobenzoyl)valerate, 18mL of dodecafluoroheptyl methacrylate, 0.035g of azobisisobutyronitrile and 40mL of anhydrous 1,4-dioxane were added to a Schrank flask equipped with a stirrer, a spherical condenser and a nitrogen delivery tube. Nitrogen gas was bubbled through the flask for 30min to remove oxygen. The Schrank flask was then immersed in a constant temperature oil bath at 70℃ and the reaction was carried out under nitrogen protection with magnetic stirring at 300r / min for 24h. After the reaction was completed, the mixture was allowed to cool naturally to 25℃ and added to 300mL of cold n-hexane to precipitate the precipitate. The precipitate was filtered, washed three times with distilled water and dried in a vacuum drying oven at 40℃ for 5.5h to obtain the reactive stabilizer. Step S2: 1.5g of reactive stabilizer, 13mL of methacryloyloxyethyltrimethylammonium chloride, 1.3mL of ethylene glycol dimethacrylate, and 125mL of 20% ethanol solution were added to a three-necked flask equipped with a stirrer and thermometer. The mixture was stirred for 13 minutes, and nitrogen gas was introduced for degassing for 30 minutes. 0.09g of azodicyanovalerate was added, and the mixture was heated to 70℃ under nitrogen protection and stirred at 200r / min for 12 hours to obtain a core-shell nanogel emulsion. The core-shell nanogel emulsion, 0.09g of photoinitiator 819, 2.5g of glycidyl methacrylate, and 100mL of deionized water were added to a photochemical reactor. Nitrogen gas was introduced at 25℃ and bubbled for 18 minutes to remove oxygen. The reaction was carried out at 365nm and 5mW / cm². 2 The mixture was stirred and reacted under ultraviolet light for 2 hours. Then, 0.02 g of hydroquinone and 3.5 g of acrylic acid were added. Under nitrogen protection, the mixture was heated to 90 °C and reacted at a constant temperature for 5.5 hours. After the reaction was completed, the mixture was naturally cooled to 25 °C and dialyzed for 72 hours using a dialysis bag with a molecular weight cutoff of 14000 Da to obtain a fluorinated antibacterial gel. Step S3: Add 9g of triphosgene and 140mL of precipitate to a three-necked flask equipped with a stirrer, thermometer, and constant pressure funnel, and mix and stir for 30min. Add 7.3g of tert-butylamine, 12g of N,N-diisopropylethylamine, and 50mL of tetrahydrofuran to a beaker, mix and stir for 30min, transfer to a constant pressure funnel, and add dropwise to the above three-necked flask at 0℃ at a rate of 1.5mL / min. Stir and react at 0℃ for 1h. Add 2.5g of 1,3-diamino-2-propanol and 20mL of tetrahydrofuran, and stir and react at 25℃ and nitrogen protection at a speed of 300r / min for 12h. Filter, concentrate the filtrate by rotary evaporation at 40℃, add 250mL of eluent, purify by silica gel column chromatography, and vacuum dry at 40℃ for 4h to obtain the precursor. The eluent is a mixture of dichloromethane and methanol at a volume ratio of 20:1. Step S4: Add 43g of low molecular weight polyethylene glycol PEG-400 to a three-necked flask equipped with a stirrer and thermometer. Vacuum stir and dehydrate at 110℃ and -0.09MPa for 1.5h. Purge with nitrogen for protection, cool to 70℃, add 52g of isophorone diisocyanate and 0.05g of dibutyltin dilaurate, and stir at 70℃ and 300r / min for 2.5h to obtain the NCO-terminated prepolymer. Add 5.5g of the precursor and 45mL of N,N-dimethylformamide to the reactor, purge with nitrogen for protection, and stir at 40℃ for 30min. Add the NCO-terminated prepolymer and 45mL... N,N-dimethylformamide was mixed and stirred for 30 min, then transferred to a constant pressure funnel and added dropwise to the reactor at 1.5 mL / min at 40 °C. The mixture was stirred at 300 r / min for 4.5 h, and then naturally cooled to 25 °C. The mixture was added to 800 mL of cold diethyl ether and precipitated for 1.5 h. The precipitate was filtered, washed three times with distilled water, and then dried under vacuum at 35 °C for 24 h to obtain the hindered urea crosslinking agent. Step S5: Weigh out the following components by weight: 15 parts fluorinated antibacterial gel, 10 parts pigment, 40 parts polytetrahydrofuran glycol PTMG-2000, 20 parts polyisocyanate, 5 parts hindered urea crosslinking agent, 1 part dispersant BYK-190, 0.3 parts defoamer BYK-028, 1 part antisettling agent AEROSIL 200, 5 parts 2,2-dimethylolpropionic acid, 0.08 parts dibutyltin dilaurate, 4 parts triethylamine, 2 parts post-chain extender aqueous solution, 10 parts curing agent, 15 parts acetone, and 100 parts deionized water; the pigment is composed of iron oxide red and barium sulfate mixed in a mass ratio of 8:12; the post-chain extender aqueous solution has a mass fraction of 40%, and the solute is ethylenediamine; the curing agent is Bayhydur® quix ultra 306-70. Step S6: Add polytetrahydrofuran diol PTMG-2000 to a reactor equipped with a stirrer, thermometer, and nitrogen protection. Dehydrate under vacuum at 110℃ and -0.09MPa for 1 hour. Cool down to 70℃, add polyisocyanate and dibutyltin dilaurate, and stir for 2.5 hours at 70℃ and 300 rpm. Add 2,2-dimethylolpropionic acid and continue the reaction for 1.5 hours. Add a hindered urea crosslinking agent and react for 2 hours. Add acetone and mix and stir for 30 minutes. Cool down to 40℃, add triethylamine, and stir for 30 minutes to obtain a prepolymer. Add the prepolymer to a disperser and add deionized water at 1800 rpm for reverse emulsification. Add the chain extender aqueous solution dropwise and continue stirring for 30 minutes. Distill under reduced pressure at 50℃ and -0.09MPa to obtain a self-healing waterborne polyurethane dispersion. Step S7: Mix dispersant BYK-190, defoamer BYK-028, and antisettling agent AEROSIL 200 at 650 r / min for 1.5 h. Add pigment and disperse at 1000 r / min for 25 min. Transfer to a sand mill and grind to a fineness ≤20 μm. Add fluorinated antibacterial gel and stir at 400 r / min for 30 min. Add self-healing waterborne polyurethane dispersion and stir at 600 r / min for 18 min. Add curing agent and continue stirring for 8 min to obtain marine static antifouling coating.

[0021] Example 3: This embodiment describes a method for preparing a marine static antifouling coating, comprising the following steps: Step S1: 0.4 g of 4-cyano-4-(thiobenzoyl)valerate, 20 mL of dodecafluoroheptyl methacrylate, 0.04 g of azobisisobutyronitrile, and 50 mL of anhydrous 1,4-dioxane were added to a Schrank flask equipped with a stirrer, a spherical condenser, and a nitrogen delivery tube. Nitrogen gas was bubbled through the flask for 30 min to remove oxygen. The Schrank flask was then immersed in a constant temperature oil bath at 70 °C and the mixture was magnetically stirred at 300 r / min for 24 h under nitrogen protection. After the reaction was completed, the mixture was allowed to cool naturally to 25 °C and added to 300 mL of cold n-hexane to precipitate the precipitate. The precipitate was filtered, washed three times with distilled water, and dried in a vacuum drying oven at 40 °C for 6 h to obtain the reactive stabilizer. Step S2: Add 2g of reactive stabilizer, 15mL of methacryloyloxyethyltrimethylammonium chloride, 1.5mL of ethylene glycol dimethacrylate, and 150mL of 20% ethanol solution to a three-necked flask equipped with a stirrer and thermometer. Mix and stir for 15min, then purge with nitrogen for 30min to degas. Add 0.1g of azodicyanovalerate, and heat to 70℃ under nitrogen protection. Mix and stir at 200r / min for 12h to obtain a core-shell nanogel emulsion. Add the core-shell nanogel emulsion, 0.1g of photoinitiator 819, 3g of glycidyl methacrylate, and 100mL of deionized water to a photochemical reactor. Purge with nitrogen at 25℃ for 20min to remove oxygen. Perform the reaction at 365nm and 5mW / cm². 2 The mixture was stirred and reacted under ultraviolet light for 2 hours. Then, 0.02 g of hydroquinone and 4 g of acrylic acid were added. Under nitrogen protection, the mixture was heated to 90°C and reacted at a constant temperature for 6 hours. After the reaction was completed, the mixture was naturally cooled to 25°C and dialyzed for 72 hours using a dialysis bag with a molecular weight cutoff of 14000 Da to obtain a fluorinated antibacterial gel. Step S3: Add 10g of triphosgene and 160mL of precipitate to a three-necked flask equipped with a stirrer, thermometer, and constant pressure funnel, and mix and stir for 30min. Add 7.5g of tert-butylamine, 13g of N,N-diisopropylethylamine, and 60mL of tetrahydrofuran to a beaker, mix and stir for 30min, transfer to a constant pressure funnel, and add dropwise to the above three-necked flask at 0℃ at a rate of 2mL / min. Stir and react at 0℃ for 1h. Add 3g of 1,3-diamino-2-propanol and 20mL of tetrahydrofuran, and stir and react at 25℃ and nitrogen protection at a speed of 300r / min for 12h. Filter, concentrate the filtrate by rotary evaporation at 40℃, add 300mL of eluent, purify by silica gel column chromatography, and vacuum dry at 40℃ for 5h to obtain the precursor. The eluent is a mixture of dichloromethane and methanol in a volume ratio of 20:1. Step S4: Add 45g of low molecular weight polyethylene glycol PEG-400 to a three-necked flask equipped with a stirrer and thermometer. Vacuum stir and dehydrate at 110℃ and -0.09MPa for 2 hours. Purge with nitrogen for protection, cool to 70℃, add 55g of isophorone diisocyanate and 0.05g of dibutyltin dilaurate, and stir at 70℃ and 300r / min for 3 hours to obtain the NCO-terminated prepolymer. Add 6g of the precursor and 50mL of N,N-dimethylformamide to the reactor. Purge with nitrogen for protection and stir at 40℃ for 30 minutes. Add the NCO-terminated prepolymer and 50mL of... N,N-dimethylformamide was mixed and stirred for 30 min, then transferred to a constant pressure funnel and added dropwise to the reactor at 40 °C at a rate of 2 mL / min. The mixture was stirred at 300 r / min for 5 h, then naturally cooled to 25 °C. The mixture was added to 800 mL of cold diethyl ether and precipitated for 2 h. The precipitate was filtered, washed three times with distilled water, and then dried under vacuum at 35 °C for 24 h to obtain the hindered urea crosslinking agent. Step S5: Weigh out the following components by weight: 25 parts fluorinated antibacterial gel, 15 parts pigment, 50 parts polytetrahydrofuran diol PTMG-2000, 25 parts polyisocyanate, 8 parts hindered urea crosslinking agent, 1.5 parts dispersant BYK-190, 0.5 parts defoamer BYK-028, 2 parts antisettling agent AEROSIL 200, 8 parts 2,2-dimethylolpropionic acid, 0.1 parts dibutyltin dilaurate, 6 parts triethylamine, 3 parts post-chain extender aqueous solution, 12 parts curing agent, 20 parts acetone, and 120 parts deionized water; the pigment is composed of iron oxide red and barium sulfate mixed in a mass ratio of 10:15; the post-chain extender aqueous solution has a mass fraction of 40%, and the solute is ethylenediamine; the curing agent is Bayhydur® quix ultra 306-70. Step S6: Add polytetrahydrofuran diol PTMG-2000 to a reactor equipped with a stirrer, thermometer, and nitrogen protection. Dehydrate under vacuum at 110℃ and -0.09MPa for 1 hour. Cool down to 70℃, add polyisocyanate and dibutyltin dilaurate, and stir for 3 hours at 70℃ and 300r / min. Add 2,2-dimethylolpropionic acid and continue the reaction for 2 hours. Add hindered urea crosslinking agent and react for 2 hours. Add acetone and mix and stir for 30 minutes. Cool down to 40℃, add triethylamine, and stir for 30 minutes to obtain a prepolymer. Add the prepolymer to a disperser and add deionized water at 2000r / min for reverse emulsification. Add the chain extender aqueous solution dropwise and continue stirring for 30 minutes. Distill under reduced pressure at 50℃ and -0.09MPa to obtain a self-healing waterborne polyurethane dispersion. Step S7: Mix dispersant BYK-190, defoamer BYK-028, and antisettling agent AEROSIL 200 at 800 r / min for 2 hours. Add pigment and disperse at 1000 r / min for 30 minutes. Transfer to a sand mill and grind to a fineness ≤20 μm. Add fluorinated antibacterial gel and stir at 400 r / min for 30 minutes. Add self-healing waterborne polyurethane dispersion and stir at 600 r / min for 20 minutes. Add curing agent and continue stirring for 10 minutes to obtain marine static antifouling coating.

[0022] Comparative Example 1: This comparative example illustrates a method for preparing a marine static antifouling coating, comprising the following steps: Step S1: Weigh out 10 parts by weight of pigment, 40 parts by weight of polytetrahydrofuran diol PTMG-2000, 20 parts by weight of polyisocyanate, 1 part by weight of dispersant BYK-190, 0.3 parts by weight of defoamer BYK-028, 1 part by weight of anti-settling agent AEROSIL 200, 5 parts by weight of 2,2-dimethylolpropionic acid, 0.08 parts by weight of dibutyltin dilaurate, 4 parts by weight of triethylamine, 2 parts by weight of post-chain extender aqueous solution, 10 parts by weight of curing agent, 15 parts by weight of acetone, and 100 parts by weight of deionized water; the pigment is composed of iron oxide red and barium sulfate mixed in a mass ratio of 8:12; the mass fraction of the post-chain extender aqueous solution is 40%, and the solute is ethylenediamine; the curing agent is Bayhydur® quix ultra306-70; Step S2: Polytetrahydrofuran diol (PTMG-2000) was added to a reactor equipped with a stirrer, thermometer, and nitrogen protection. It was dehydrated at 110°C and -0.09 MPa vacuum for 1 hour. The temperature was lowered to 70°C, and polyisocyanate and dibutyltin dilaurate were added. The mixture was stirred at 70°C and 300 rpm for 2.5 hours. 2,2-dimethylolpropionic acid was added, and the reaction continued for 1.5 hours. Acetone was added, and the mixture was stirred for 30 minutes. The temperature was lowered to 40°C, and triethylamine was added. The mixture was stirred for 30 minutes to obtain a prepolymer. The prepolymer was added to a disperser, and deionized water was added at 1800 rpm for phase conversion emulsification. A chain extender aqueous solution was added dropwise, and the mixture was stirred for another 30 minutes. The mixture was then distilled under reduced pressure at 50°C and -0.09 MPa to obtain a self-healing waterborne polyurethane dispersion. Step S3: Mix dispersant BYK-190, defoamer BYK-028, and antisettling agent AEROSIL 200 at 650 r / min for 1.5 h. Add pigment and disperse at 1000 r / min for 25 min. Transfer to a sand mill and grind to a fineness ≤20 μm. Stir at 400 r / min for 30 min. Add self-healing waterborne polyurethane dispersion and stir at 600 r / min for 18 min. Add curing agent and continue stirring for 8 min to obtain marine static antifouling coating.

[0023] Comparative Example 2: This comparative example illustrates a method for preparing a marine static antifouling coating, comprising the following steps: Step S1: 0.3g of 4-cyano-4-(thiobenzoyl)valerate, 18mL of dodecafluoroheptyl methacrylate, 0.035g of azobisisobutyronitrile and 40mL of anhydrous 1,4-dioxane were added to a Schrank flask equipped with a stirrer, a spherical condenser and a nitrogen delivery tube. Nitrogen gas was bubbled through the flask for 30min to remove oxygen. The Schrank flask was then immersed in a constant temperature oil bath at 70℃ and the reaction was carried out under nitrogen protection with magnetic stirring at 300r / min for 24h. After the reaction was completed, the mixture was allowed to cool naturally to 25℃ and added to 300mL of cold n-hexane to precipitate the precipitate. The precipitate was filtered, washed three times with distilled water and dried in a vacuum drying oven at 40℃ for 5.5h to obtain the reactive stabilizer. Step S2: 1.5g of reactive stabilizer, 13mL of methacryloyloxyethyltrimethylammonium chloride, 1.3mL of ethylene glycol dimethacrylate, and 125mL of 20% ethanol solution were added to a three-necked flask equipped with a stirrer and thermometer. The mixture was stirred for 13 minutes, and nitrogen gas was introduced for degassing for 30 minutes. 0.09g of azodicyanovalerate was added, and the mixture was heated to 70℃ under nitrogen protection and stirred at 200r / min for 12 hours to obtain a core-shell nanogel emulsion. The core-shell nanogel emulsion, 0.09g of photoinitiator 819, 2.5g of glycidyl methacrylate, and 100mL of deionized water were added to a photochemical reactor. Nitrogen gas was introduced at 25℃ and bubbled for 18 minutes to remove oxygen. The reaction was carried out at 365nm and 5mW / cm². 2 The mixture was stirred and reacted under ultraviolet light for 2 hours. Then, 0.02 g of hydroquinone and 3.5 g of acrylic acid were added. Under nitrogen protection, the mixture was heated to 90 °C and reacted at a constant temperature for 5.5 hours. After the reaction was completed, the mixture was naturally cooled to 25 °C and dialyzed for 72 hours using a dialysis bag with a molecular weight cutoff of 14000 Da to obtain a fluorinated antibacterial gel. Step S3: Weigh out the following components by weight: 15 parts fluorinated antibacterial gel, 10 parts pigment, 40 parts polytetrahydrofuran diol PTMG-2000, 20 parts polyisocyanate, 1 part dispersant BYK-190, 0.3 parts defoamer BYK-028, 1 part anti-settling agent AEROSIL200, 5 parts 2,2-dimethylolpropionic acid, 0.08 parts dibutyltin dilaurate, 4 parts triethylamine, 2 parts post-chain extender aqueous solution, 10 parts curing agent, 15 parts acetone, and 100 parts deionized water; the pigment is composed of iron oxide red and barium sulfate mixed in a mass ratio of 8:12; the post-chain extender aqueous solution has a mass fraction of 40%, and the solute is ethylenediamine; the curing agent is Bayhydur® quix ultra 306-70. Step S4: Polytetrahydrofuran diol (PTMG-2000) was added to a reactor equipped with a stirrer, thermometer, and nitrogen protection. It was dehydrated at 110°C and -0.09 MPa vacuum for 1 hour. The temperature was lowered to 70°C, and polyisocyanate and dibutyltin dilaurate were added. The mixture was stirred at 70°C and 300 rpm for 2.5 hours. 2,2-dimethylolpropionic acid was added, and the reaction continued for 1.5 hours. Acetone was added, and the mixture was stirred for 30 minutes. The temperature was lowered to 40°C, and triethylamine was added. The mixture was stirred for 30 minutes to obtain a prepolymer. The prepolymer was added to a disperser, and deionized water was added at 1800 rpm for phase conversion emulsification. A chain extender aqueous solution was added dropwise, and the mixture was stirred for another 30 minutes. The mixture was then distilled under reduced pressure at 50°C and -0.09 MPa to obtain a self-healing waterborne polyurethane dispersion. Step S5: Mix dispersant BYK-190, defoamer BYK-028, and antisettling agent AEROSIL 200 at 650 r / min for 1.5 h. Add pigment and disperse at 1000 r / min for 25 min. Transfer to a sand mill and grind to a fineness ≤20 μm. Add fluorinated antibacterial gel and stir at 400 r / min for 30 min. Add self-healing waterborne polyurethane dispersion and stir at 600 r / min for 18 min. Add curing agent and continue stirring for 8 min to obtain marine static antifouling coating.

[0024] Comparative Example 3: This comparative example illustrates a method for preparing a marine static antifouling coating, comprising the following steps: Step S1: Add 9g of triphosgene and 140mL of precipitate to a three-necked flask equipped with a stirrer, thermometer, and constant pressure funnel, and mix and stir for 30min. Add 7.3g of tert-butylamine, 12g of N,N-diisopropylethylamine, and 50mL of tetrahydrofuran to a beaker, mix and stir for 30min, transfer to a constant pressure funnel, and add dropwise to the above three-necked flask at 0℃ at a rate of 1.5mL / min. Stir and react at 0℃ for 1h. Add 2.5g of 1,3-diamino-2-propanol and 20mL of tetrahydrofuran, and stir and react at 25℃ and nitrogen protection at a speed of 300r / min for 12h. Filter, concentrate the filtrate by rotary evaporation at 40℃, add 250mL of eluent, purify by silica gel column chromatography, and vacuum dry at 40℃ for 4h to obtain the precursor. The eluent is a mixture of dichloromethane and methanol in a volume ratio of 20:1. Step S2: Add 43g of low molecular weight polyethylene glycol PEG-400 to a three-necked flask equipped with a stirrer and thermometer. Vacuum stir and dehydrate at 110℃ and -0.09MPa for 1.5h. Purge with nitrogen for protection, cool to 70℃, add 52g of isophorone diisocyanate and 0.05g of dibutyltin dilaurate, and stir at 70℃ and 300r / min for 2.5h to obtain the NCO-terminated prepolymer. Add 5.5g of the precursor and 45mL of N,N-dimethylformamide to the reactor, purge with nitrogen for protection, and stir at 40℃ for 30min. Add the NCO-terminated prepolymer and 45mL... N,N-dimethylformamide was mixed and stirred for 30 min, then transferred to a constant pressure funnel and added dropwise to the reactor at 1.5 mL / min at 40 °C. The mixture was stirred at 300 r / min for 4.5 h, and then naturally cooled to 25 °C. The mixture was added to 800 mL of cold diethyl ether and precipitated for 1.5 h. The precipitate was filtered, washed three times with distilled water, and then dried under vacuum at 35 °C for 24 h to obtain the hindered urea crosslinking agent. Step S3: Weigh out 10 parts by weight of pigment, 40 parts by weight of polytetrahydrofuran diol PTMG-2000, 20 parts by weight of polyisocyanate, 5 parts by weight of hindered urea crosslinking agent, 1 part by weight of dispersant BYK-190, 0.3 parts by weight of defoamer BYK-028, 1 part by weight of anti-settling agent AEROSIL200, 5 parts by weight of 2,2-dimethylolpropionic acid, 0.08 parts by weight of dibutyltin dilaurate, 4 parts by weight of triethylamine, 2 parts by weight of post-chain extender aqueous solution, 10 parts by weight of curing agent, 15 parts by weight of acetone, and 100 parts by weight of deionized water; the pigment is composed of iron oxide red and barium sulfate mixed in a mass ratio of 8:12; the mass fraction of the post-chain extender aqueous solution is 40%, and the solute is ethylenediamine; the curing agent is Bayhydur® quix ultra 306-70; Step S4: Polytetrahydrofuran diol (PTMG-2000) was added to a reactor equipped with a stirrer, thermometer, and nitrogen protection. It was dehydrated at 110°C and -0.09 MPa vacuum for 1 hour. The temperature was then lowered to 70°C, and polyisocyanate and dibutyltin dilaurate were added. The mixture was stirred at 70°C and 300 rpm for 2.5 hours. 2,2-dimethylolpropionic acid was added, and the reaction continued for 1.5 hours. A hindered urea crosslinking agent was added, and the reaction continued for 2 hours. Acetone was added, and the mixture was stirred for 30 minutes. The temperature was lowered to 40°C, and triethylamine was added. The mixture was stirred for 30 minutes to obtain a prepolymer. The prepolymer was added to a disperser, and deionized water was added at 1800 rpm for phase re-emulsification. A chain extender aqueous solution was added dropwise, and the mixture was stirred for another 30 minutes. The mixture was then distilled under reduced pressure at 50°C and -0.09 MPa to obtain a self-healing waterborne polyurethane dispersion. Step S5: Mix dispersant BYK-190, defoamer BYK-028 and antisettling agent AEROSIL 200 at 650 r / min for 1.5 h, add pigment, disperse at 1000 r / min for 25 min, transfer to a sand mill and grind to fineness ≤20 μm, stir at 400 r / min for 30 min, add self-healing waterborne polyurethane dispersion, stir at 600 r / min for 18 min, add curing agent, and continue stirring for 8 min to obtain marine static antifouling coating.

[0025] The marine static antifouling coatings prepared in Examples 1-3 and Comparative Examples 1-3 were applied and cured to obtain a marine antifouling coating with a thickness of 150 μm. The contact angles of the coating surface with deionized water and diiodomethane were measured using an XG-CAMC3 fully automatic contact angle measuring instrument manufactured by Shanghai Xuanzhun Instruments Co., Ltd. The surface energy of the coating was then calculated using the Owens two-liquid method. Antifouling scores for Examples 1-3 and Comparative Examples 1-3 were tested according to the national standard GB / T 5370-2007, "Antifouling Paint Sample Shallow Sea Immersion Test Method." Static shallow sea immersion tests were conducted in the Nantong sea area to evaluate the antifouling performance of the coatings. The tests were carried out at the Nantong Qidong Port floating dock. The prepared immersion plates were vertically submerged in seawater 1 to 2 meters below sea level. After 6 months, the immersion plates were observed and inspected, and the degree of attachment of marine fouling organisms was measured. The test results are shown in the table below.

[0026] Comparing Examples 1-3 with Comparative Examples 1-3: In Example 1, the amounts of fluorinated antibacterial gel and hindered urea crosslinking agent were relatively low. The insufficient amount of fluorinated antibacterial gel resulted in insufficient enrichment concentration of fluorinated segments on the coating surface, leading to a higher surface energy and limited anti-adhesion and repellency ability against barnacle larvae and algal spores. Fouling organisms could still complete initial attachment with a low probability. Furthermore, the low amount of hindered urea crosslinking agent resulted in insufficient dynamic hindered urea bond density in the coating crosslinking network. The resulting microcracks could not self-repair, and the cracks became sites of seawater infiltration and fouling. The coating has weak points for bioinvasion, resulting in a low antifouling score. Example 2, with moderate amounts of fluorinated antibacterial gel and hindered urea crosslinking agent, reduced the coating surface energy, significantly enhanced the low-surface-energy fouling release mechanism, and effectively suppressed fouling bioattachment. Simultaneously, the increased density of hindered urea bonds enabled the coating to self-repair through more dynamic exchange sites when micro-damage occurs, blocking the invasion path of seawater and fouling organisms along defects. Example 3, with higher amounts of fluorinated antibacterial gel and hindered urea crosslinking agent, further reduced surface energy and improved antifouling performance. The performance is superior. Comparing Example 2 with Comparative Example 1, it can be seen that: Comparative Example 1 is a pure water-based polyurethane coating without the addition of fluorinated antibacterial gel and hindered urea crosslinking agent, lacking a low surface energy antifouling interface. Fouling organisms can adhere to the coating surface. Due to the lack of hindered urea crosslinking agent, the coating swells and cracks after immersion, exposing the high surface energy substrate material, which further accelerates the adhesion of fouling organisms. Comparing Example 2 with Comparative Example 2, it can be seen that: Comparative Example 2 only added fluorinated antibacterial gel without the addition of hindered urea crosslinking agent, resulting in lower surface energy and water contact angle. Similar to Example 2, it can effectively inhibit the adhesion of fouling organisms. When microcracks are generated in the coating, due to the lack of a dynamic covalent bond network provided by the hindered urea crosslinking agent, the cracks cannot heal themselves, and fouling organisms attach and multiply at these defect sites, reducing the antifouling ability. Comparing Example 2 with Comparative Example 3, it can be seen that: Comparative Example 3 added a hindered urea crosslinking agent but did not add fluorinated antibacterial gel. The surface lacks fluorinated segments and quaternary ammonium salt groups, and the coating surface does not have low surface energy fouling release function and contact antibacterial repellency function, resulting in poor antifouling performance.

[0027] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0028] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in this application, they should all fall within the protection scope of the present invention.

Claims

1. A method for preparing a marine static antifouling coating, characterized by, Includes the following steps: Step 1: Weigh out the following components by weight: 5-25 parts fluorinated antibacterial gel, 5-15 parts pigment, 30-50 parts polytetrahydrofuran glycol, 15-25 parts polyisocyanate, 2-8 parts hindered urea crosslinking agent, 0.5-1.5 parts dispersant, 0.2-0.5 parts defoamer, 0.5-2 parts anti-settling agent, 3-8 parts chain extender, 0.05-0.1 parts catalyst, 3-6 parts neutralizer, 1-3 parts post-chain extender aqueous solution, 8-12 parts curing agent, 10-20 parts acetone, and 80-120 parts deionized water. Step 2: Dehydrate polytetrahydrofuran glycol under vacuum, add polyisocyanate and catalyst and stir to react, add chain extender and react, then add hindered urea crosslinking agent and acetone and mix, add neutralizer and stir to obtain prepolymer; add prepolymer to disperser, add deionized water for reverse emulsification, add chain extender aqueous solution dropwise and stir, distill under reduced pressure to obtain self-healing waterborne polyurethane dispersion; Step 3: Mix the dispersant, defoamer, and antisettling agent, add the pigment for dispersion, transfer to a sand mill for grinding, add fluorinated antibacterial gel and stir, add self-healing waterborne polyurethane dispersion and stir, add curing agent and continue stirring to obtain marine static antifouling coating.

2. The method for preparing a marine static antifouling coating according to claim 1, characterized in that, The pigment is composed of iron oxide red and barium sulfate mixed in a mass ratio of 5-10:10-15; the polytetrahydrofuran diol is PTMG-2000; the dispersant is BYK-190; the defoamer is BYK-028; the anti-settling agent is AEROSIL 200; the chain extender is 2,2-dimethylolpropionic acid; the catalyst is dibutyltin dilaurate; the neutralizing agent is triethylamine; the post-chain extender aqueous solution has a mass fraction of 40%, and the solute is ethylenediamine; the curing agent is Bayhydur® quix ultra 306-70.

3. The method for preparing a marine static antifouling coating according to claim 1, characterized in that, The fluorinated antibacterial gel is prepared by the following steps: Step a1: Add disulfide ester chain transfer agent, fluorinated acrylate monomer, initiator and anhydrous 1,4-dioxane to a Schrank flask, purge with nitrogen to remove oxygen, immerse in a constant temperature oil bath and stir to react, cool naturally, add to cold n-hexane to precipitate, filter, wash the precipitate, and vacuum dry to obtain a reactive stabilizer. Step a2: Mix and stir the reactive stabilizer, quaternary ammonium salt monomer, crosslinking agent and mixed solvent, degas with nitrogen, add initiator, heat and stir to react, and obtain core-shell nanogel emulsion; add core-shell nanogel emulsion, photoinitiator, glycidyl methacrylate and deionized water to photochemical reactor, bubble with nitrogen to remove oxygen, stir to react under ultraviolet irradiation, add polymerization inhibitor and acrylic acid, heat to react, cool, dialyze to obtain fluorinated antibacterial gel.

4. The method for preparing a marine static antifouling coating according to claim 3, characterized in that, In step a1, the ratio of the dithioester chain transfer agent, the fluorinated acrylate monomer, the initiator, anhydrous 1,4-dioxane, and cold n-hexane is 0.2-0.4 g: 15-20 mL: 0.03-0.04 g: 30-50 mL: 300 mL; the dithioester chain transfer agent is 4-cyano-4-(thiobenzoyl)valerate; the fluorinated acrylate monomer is dodecafluoroheptyl methacrylate; and the initiator is azobisisobutyronitrile.

5. The method for preparing a marine static antifouling coating according to claim 3, characterized in that, In step a2, the ratio of the reactive stabilizer, quaternary ammonium salt monomer, crosslinking agent, mixed solvent, initiator, photoinitiator, glycidyl methacrylate, deionized water, polymerization inhibitor, and acrylic acid is 1-2g:10-15mL:1-1.5mL:100-150mL:0.08-0.1g:0.08-0.1g:2-3g:100mL:0.02g:3-4g; the quaternary ammonium salt monomer is methacryloyloxyethyltrimethylammonium chloride; the crosslinking agent is ethylene glycol dimethacrylate; the mixed solvent is a 20% (w / w) ethanol solution; the initiator is azobiscyanopentanoic acid; the photoinitiator is photoinitiator 819; and the polymerization inhibitor is hydroquinone.

6. The method for preparing a marine static antifouling coating according to claim 1, characterized in that, The hindered urea bond crosslinking agent is prepared by the following steps: Step b1: Add triphosgene and the first part of tetrahydrofuran to a three-necked flask and mix and stir; mix tert-butylamine, acid-binding agent and the second part of tetrahydrofuran and stir, transfer to a constant pressure funnel, add dropwise to the above three-necked flask and stir to react, add 1,3-diamino-2-propanol and the third part of tetrahydrofuran and stir to react, filter, concentrate the filtrate by rotary evaporation, add eluent, purify by silica gel column chromatography, dry, and obtain the precursor; Step b2: Low molecular weight polyethylene glycol is dehydrated by vacuum stirring, and isophorone diisocyanate and catalyst are added and stirred to obtain NCO-terminated prepolymer; the precursor and the first part of N,N-dimethylformamide are added to the reactor and stirred; the NCO-terminated prepolymer and the second part of N,N-dimethylformamide are mixed, transferred to a constant pressure funnel, and added dropwise to the above reactor and stirred to react. After cooling, the mixture is added to cold diethyl ether to precipitate, filtered, washed, and dried to obtain the hindered urea bond crosslinking agent.

7. The method for preparing a marine static antifouling coating according to claim 6, characterized in that, In step b1, the ratio of triphosgene, total tetrahydrofuran, tert-butylamine, acid-binding agent, 1,3-diamino-2-propanol, and eluent is 8-10g: 180-240mL: 7-7.5g: 10-13g: 2-3g: 200-300mL; the first part of tetrahydrofuran accounts for 2 / 3 of the total tetrahydrofuran; the second part of tetrahydrofuran accounts for 2 / 9 of the total tetrahydrofuran; the third part of tetrahydrofuran accounts for 1 / 9 of the total tetrahydrofuran; the acid-binding agent is N,N-diisopropylethylamine; and the eluent is a mixture of dichloromethane and methanol at a volume ratio of 20:

1.

8. The method for preparing a marine static antifouling coating according to claim 6, characterized in that, The total amount of low molecular weight polyethylene glycol, isophorone diisocyanate, catalyst, precursor, N,N-dimethylformamide, and cold diethyl ether in step b2 is 40-45g:48-55g:0.05g:5-6g:80-100mL:800mL; the type of low molecular weight polyethylene glycol is PEG-400; the catalyst is dibutyltin dilaurate; the first part of N,N-dimethylformamide accounts for 1 / 2 of the total amount of N,N-dimethylformamide; the second part of N,N-dimethylformamide accounts for 1 / 2 of the total amount of N,N-dimethylformamide.

9. The application of a marine static antifouling coating prepared by the method of any one of claims 1-8 on the surface of marine facilities.

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