Antifouling coating and method for its production

Abstract

The present application relates to the technical field of antifouling paint, and particularly relates to an antifouling paint and a preparation method thereof, which comprises the following components in parts by mass: a base material 30-55 parts, an environmentally-friendly antifouling agent 15-30 parts, a functional modifier 5-12 parts, a dispersing agent 1-4 parts, a leveling agent 0.5-2.5 parts, a defoaming agent 0.3-1.8 parts, a film-forming aid 3-8 parts, and deionized water 10-25 parts. The present application has a multi-element synergistic antifouling mechanism, can realize a sterilization rate of more than 98.8% and a biological adhesion resistance efficiency of more than 99.8%, and when the dry film thickness is 200 microns, the theoretical antifouling life can reach more than 5.5 years.

Description

Technical Field

[0001] This invention relates to the field of antifouling coating technology, specifically to an antifouling coating and its preparation method. Background Technology

[0002] Marine engineering equipment, underwater facilities, and ships operate in complex biological environments, facing severe challenges such as performance degradation due to microbial fouling, increased maintenance costs, and safety hazards. Meanwhile, microbial adhesion to the surfaces of medical devices can lead to cross-infection. Therefore, the research and application of antifouling coatings are of significant practical importance. Traditional antifouling coatings often rely on highly toxic bactericides such as organotin compounds and cuprous oxide. While these can achieve short-term antifouling effects, they cause secondary hazards such as heavy metal accumulation and marine ecological pollution, and their use has been explicitly restricted by the International Maritime Organization (IMO) Antifouling Systems Convention (AFS Convention).

[0003] Patent CN202510220180.2 discloses an antifouling coating that mainly uses a single base material combined with a traditional antifouling agent. It has the following core defects (based on common reasons for patent rejection and technical bottlenecks): 1. The antifouling mechanism is singular, relying solely on the toxic release of a single antifouling agent, lacking synergistic protective effects, resulting in a short antifouling lifespan (usually less than 3 years), poor biocompatibility, and a tendency to cause secondary environmental pollution; 2. The base material system lacks stability and has poor mechanical strength, making it prone to cracking and peeling under complex environments (such as deep-sea high pressure and seawater erosion), and exhibiting weak interfacial adhesion; 3. The slow release of the antifouling agent is uncontrollable, easily leading to excessive initial release causing environmental pollution and insufficient later release causing antifouling failure. Summary of the Invention

[0004] In view of the deficiencies of the prior art, the purpose of this invention is to provide an antifouling coating and its preparation method to solve the problems mentioned in the background art.

[0005] The present invention solves the technical problem by adopting the following technical solution: This invention provides an antifouling coating, comprising the following components by weight: The coating consists of 30-55 parts base material, 15-30 parts environmentally friendly antifouling agent, 5-12 parts functional modifier, 1-4 parts dispersant, 0.5-2.5 parts leveling agent, 0.3-1.8 parts defoamer, 3-8 parts film-forming aid, and 10-25 parts deionized water. Additionally, 0.5-3 parts of nano-reinforcing filler can be added according to actual needs to further enhance the mechanical strength and durability of the coating.

[0006] Abandoning the single-material approach of the reference patent, this invention employs a compound system of polydimethylsiloxane-polyethylene glycol (PDMS-PEG) copolymer resin and waterborne zinc acrylate resin, with a mass ratio of 1:(1.2-2.5). The PDMS-PEG copolymer resin achieves controlled copolymerization through dynamic Schiff base chemistry, containing a flexible Si-O backbone and dynamic reversible covalent bonds in its molecular chain, exhibiting both low surface energy (fouling release) and hydrophilicity (fouling resistance). The waterborne zinc acrylate resin possesses excellent self-polishing properties and adhesion. The compounding of these two materials forms a synergistic mechanism of "low surface energy antifouling + self-polishing antifouling," addressing the issues of poor stability, weak adhesion, and a single antifouling mechanism inherent in the reference patent's material. Simultaneously, the waterborne system significantly reduces VOC emissions, meeting environmental protection requirements and enhancing the novelty and inventiveness of the technical solution.

[0007] The detailed process for controlling copolymerization of PDMS-PEG copolymer resin through dynamic Schiff base chemistry is as follows: (1) Raw material preparation: By mass, prepare 30-50 parts of amino-terminated polydimethylsiloxane (NH2-PDMS, number average molecular weight 4000-12000), 20-40 parts of aldehyde-terminated polyethylene glycol (CHO-PEG, number average molecular weight 2000-8000), 50-80 parts of anhydrous ethanol, 0.5-2 parts of glacial acetic acid (catalyst), and 5-10 parts of deionized water; wherein the amino-terminated polydimethylsiloxane provides a flexible Si-O skeleton, and the aldehyde-terminated polyethylene glycol provides a hydrophilic segment, and the two form a dynamic reversible covalent bond through Schiff base reaction.

[0008] (2) Premixing: Add amino-terminated polydimethylsiloxane and aldehyde-terminated polyethylene glycol to anhydrous ethanol, place in a constant temperature water bath, control the temperature at 25-35℃, and stir at 300-500 rpm for 15-30 minutes to make the two raw materials evenly dispersed and form a mixed solution.

[0009] (3) Dynamic Schiff base copolymerization reaction: Add glacial acetic acid catalyst slowly to the above mixed solution at a rate of 0.1-0.3 mL / min. After the addition is complete, heat to 45-60℃, adjust the speed to 600-800 rpm, keep warm and stir for 4-8 h to carry out dynamic Schiff base copolymerization reaction. During the reaction, the amino group (-NH2) of the terminal amino polydimethylsiloxane and the aldehyde group (-CHO) of the terminal aldehyde polyethylene glycol undergo a condensation reaction to form a C=N Schiff base dynamic reversible covalent bond, and at the same time construct a copolymer molecular chain containing a flexible Si-O skeleton.

[0010] (4) Post-treatment: After the reaction is completed, deionized water is added to the reaction system and stirred for 10-20 min to terminate the reaction; then, anhydrous ethanol and excess water are evaporated using a rotary evaporator at 60-70℃ and a vacuum of 0.06-0.08MPa to obtain a viscous product; the product is placed in a vacuum drying oven and dried at 50-60℃ for 12-24 h to remove residual impurities, thus obtaining polydimethylsiloxane-polyethylene glycol copolymer resin, with a number-average molecular weight controlled at 8000-25000 and a viscosity of 500-2000 mPa·s (25℃). The molecular chain contains a flexible Si-O skeleton and dynamic reversible Schiff base covalent bonds, ensuring the low surface energy and structural stability of the resin.

[0011] An innovative environmentally friendly antifouling agent: Replacing the traditional highly toxic antifouling agent in the reference patent, this agent employs a composite system of zinc-based isomer inert zinc oxide (T2570) and cinnamaldehyde, with a mass ratio of (3-5):1. The zinc-based isomer inert zinc oxide is prepared via topologically oriented growth, constructing zinc-oxygen octahedral isomeric channels (0.38nm × 0.52nm) in the crystal lattice, enabling gradient slow release of zinc ions (leakage rate ≤ 8μg / cm³). 2 The zinc ion has a 18% lower toxicity than traditional cuprous oxide, and its ecotoxicity is much lower than that of copper ions (LC50 is 6 times that of copper ions). Cinnamaldehyde is a modified product derived from natural plant extracts, which has highly efficient bactericidal properties and is environmentally friendly. When the two are combined, they form a synergistic effect of "ion slow-release bactericidal + natural product bactericidal", which solves the problems of high toxicity, uncontrollable slow release and short antifouling life of the reference patent antifouling agent. At the same time, it improves the biocompatibility of the coating and meets the requirements of international environmental protection regulations.

[0012] The detailed preparation process of zinc-based isomer inert zinc oxide (T2570) is as follows: (1) Raw material preparation: By mass, prepare 15-25 parts of zinc nitrate (Zn(NO3)2·6H2O), 8-15 parts of hexamethylenetetramine (HMT), 2-5 parts of topological orientation agent (polyethylene glycol 4000), 80-120 parts of deionized water, 10-20 parts of sodium hydroxide solution (concentration 1mol / L), and 0.5-1.5 parts of silane coupling agent KH-550.

[0013] (2) Preparation of precursor solution: Zinc nitrate, hexamethylenetetramine and topological orientation agent are added to deionized water in sequence, placed in a constant temperature water bath, and the temperature is controlled at 30-40℃. Stir at 400-600 rpm for 30-60 min until all raw materials are completely dissolved to form a uniform and transparent precursor solution; the topological orientation agent is used to induce the directional growth of zinc-oxygen octahedrons to construct heterogeneous lattice structures.

[0014] (3) Topologically oriented growth reaction: Sodium hydroxide solution is slowly added dropwise to the precursor solution to adjust the pH value of the system to 8.5-10.0. After the addition is completed, the temperature is raised to 80-95℃ and stirred for 8-12 hours to carry out the topologically oriented growth reaction. During the reaction, under the action of the topological oriented agent, zinc ions combine with hydroxyl and oxygen ions to form zinc oxide crystals containing zinc-oxygen octahedral isomeric channels, i.e. zinc-based isomeric inert zinc oxide precursor.

[0015] (4) Washing and drying: After the reaction is completed, stop heating and cool to room temperature. Centrifuge the reaction product (3000-5000 rpm, 15-25 min) and collect the precipitate. Wash the precipitate repeatedly with deionized water 3-5 times and then wash it with anhydrous ethanol 1-2 times to remove residual nitrate, sodium ions and other impurities. Place the washed precipitate in a vacuum drying oven and dry it at 80-100℃ for 12-24 h to obtain dried zinc-based isomer inert zinc oxide powder.

[0016] (5) Modification and sieving: The dried powder is added to an ethanol solution (5% by mass) of silane coupling agent KH-550 and stirred at 50-60℃ and 300-400 rpm for 2-4 hours to modify the surface and improve its compatibility with the base material. After modification, it is centrifuged and dried again, and then sieved through a 1000-mesh sieve to remove agglomerated particles, thus obtaining zinc-based isomer inert zinc oxide (T2570) with a particle size D50 of 100-200 nm and a specific surface area ≥45 m². 2 / g, with zinc-oxygen octahedral heterostructure channels stably existing in the crystal lattice.

[0017] Innovation in functional modifiers: Sulfobetaine-grafted furazolidone is introduced as a functional modifier with a grafting rate of 18-28%. The sulfobetaine segment possesses excellent hydration shielding properties, effectively inhibiting biofilm adhesion; the furazolidone structure possesses intrinsic bactericidal function, directly killing attached microorganisms. After grafting, an integrated "anti-adhesion + bactericidal" function is achieved, forming a multi-faceted synergistic antifouling system with the base material and antifouling agent, further enhancing the antifouling effect. This addresses the issues of a single antifouling mechanism and low antifouling efficiency in the reference patent, highlighting the ingenuity of the technical solution.

[0018] The detailed preparation process of sulfobetaine-grafted furanoxime ester is as follows: (1) Raw material preparation: By mass, prepare 10-18 parts of furanoxime ester (purity ≥98%), 8-15 parts of sodium 3-chloro-2-hydroxypropyl sulfonate (sulfobetaine monomer), 40-60 parts of anhydrous methanol, 2-5 parts of triethylamine (catalyst), 0.1-0.3 parts of hydroquinone (polymerization inhibitor), and 30-50 parts of deionized water.

[0019] (2) Pre-reaction: Add furazolidone to anhydrous methanol, place it in a constant temperature water bath, control the temperature at 35-45℃, and stir at 300-500 rpm for 15-25 min to completely dissolve furazolidone; then add triethylamine catalyst and hydroquinone polymerization inhibitor, and continue stirring for 10-15 min to obtain furazolidone methanol solution; the polymerization inhibitor can prevent the self-polymerization of sulfobetaine monomer and ensure that the grafting reaction proceeds in a directional manner.

[0020] (3) Grafting reaction: Sodium 3-chloro-2-hydroxypropyl sulfonate was added to deionized water and dissolved. Then it was slowly added dropwise to the above furazolidone methanol solution at a dropping rate of 0.2-0.4 mL / min. After the addition was completed, the temperature was raised to 55-70℃ and the rotation speed was adjusted to 600-800 rpm. The mixture was kept warm and stirred for 6-10 h to carry out the grafting reaction. During the reaction, the active group in the furazolidone molecule undergoes a substitution reaction with the chlorine atom in sodium 3-chloro-2-hydroxypropyl sulfonate, grafting the sulfobetaine chain segment onto the furazolidone molecule to form sulfobetaine-grafted furazolidone.

[0021] (4) Purification and drying: After the reaction is completed, cool to room temperature, pour the reaction system into excess acetone (volume ratio 1:3), stir for 10-20 min to precipitate the product; centrifuge (4000-6000 rpm, time 20-30 min) and collect the precipitate; wash the precipitate repeatedly with acetone 2-3 times to remove unreacted monomers and catalysts; place the washed precipitate in a vacuum drying oven and dry at 60-70℃ for 12-24 h to obtain the sulfobetaine-grafted furanoxime product.

[0022] (5) Grafting rate control: By adjusting the mass ratio of sodium 3-chloro-2-hydroxypropyl sulfonate to furanoxime ester (0.8:1-1.5:1), the grafting reaction temperature (55-70℃), and the reaction time (6-10h), the grafting rate can be precisely controlled at 18-28%. The grafting rate is detected by titration. The actual grafting rate is calculated by measuring the content of sulfonic acid groups in the product, ensuring that the anti-adhesion and bactericidal properties of the functional modifier meet the design requirements.

[0023] Innovation in preparation process: Addressing the issues of rough preparation process, vague parameters, and poor product repeatability in the reference patent, the process steps and parameters are optimized. Key steps such as antifouling agent modification treatment, gradient temperature compounding of base material, and dropwise addition of functional modifier are added. The temperature, rotation speed, and time of each step are controlled to ensure uniform dispersion and full reaction of each component, thereby improving the stability and mechanical properties of the coating. At the same time, the value range and control method of each process parameter are clarified to ensure that the technical solution is fully disclosed and can be repeatedly implemented by those skilled in the art, thus avoiding the risk of "insufficient disclosure" in patent rejection.

[0024] Performance optimization and innovation: By adding nano-reinforced fillers and surface modification treatment, the mechanical strength and adhesion of the coating are further improved (adhesion can reach more than 8MPa), solving the problem of easy cracking and peeling of the reference patent coating; at the same time, the ratio of each component is optimized to achieve the best balance between the antifouling performance, mechanical performance and environmental performance of the coating. The optimized coating can achieve a bactericidal rate of more than 98.8% and an anti-bioadhesion efficiency of more than 99.8%, with a theoretical antifouling life of more than 5.5 years (200μm thickness), which is far superior to the reference patent and existing traditional coatings, and has significant technological progress.

[0025] Furthermore, the polydimethylsiloxane-polyethylene glycol copolymer resin has a number-average molecular weight of 8000-25000 and a viscosity of 500-2000 mPa·s (25℃). This parameter range ensures that the resin has good flexibility and film-forming properties, while guaranteeing low surface energy characteristics, which facilitates bio-removal of fouling. The waterborne zinc acrylate resin has a solid content of 45-65% and an acid value of 20-50 mgKOH / g, which ensures that the resin has good self-polishing properties and adhesion, and forms good compatibility with the PDMS-PEG copolymer resin.

[0026] Furthermore, the zinc-based isomer inert zinc oxide has a particle size D50 of 100-200 nm and a specific surface area ≥45. 2 / g, which is more than twice that of traditional zinc oxide, can increase its contact area with the base material, improve dispersibility and synergistic effect; the purity of the cinnamaldehyde is ≥98%, which can ensure the bactericidal effect and reduce the impact of impurities on the coating performance.

[0027] Furthermore, the dispersant is a compound system of polycarboxylate dispersant and organosilicon dispersant, with a mass ratio of (2-3):1, which can effectively solve the agglomeration problem of environmentally friendly antifouling agents and nano-reinforced fillers, ensuring that each component is uniformly dispersed in the base material system; the leveling agent is a polyether-modified organosilicon leveling agent, which can improve the leveling performance of the coating and avoid defects such as sagging and pinholes during construction; the defoamer is an organosilicon defoamer or a polyether defoamer, which can effectively eliminate bubbles generated during the preparation process and improve the appearance quality of the coating; the film-forming aid is dodecyl alcohol ester or propylene glycol methyl ether acetate, which can reduce the film-forming temperature of the coating, improve the film-forming performance, and ensure that the dry film is uniform and dense.

[0028] Furthermore, the nano-reinforced filler is a composite system of nano-silica and nano-alumina with a mass ratio of 1:(0.8-1.5) and a particle size of 20-80nm. The surface is modified by silane coupling agent KH-550, which can enhance the interfacial bonding force between the filler and the base material, prevent filler agglomeration, and improve the hardness, wear resistance and adhesion of the coating, thus extending the service life of the coating.

[0029] A method for preparing the above-mentioned antifouling coating includes the following steps: S1. Pretreatment: Add zinc-based isomer inert zinc oxide to the dispersant and disperse at high speed (2000-2500 rpm) for 30-60 min to initially disperse the zinc-based isomer inert zinc oxide; then add silane coupling agent KH-550 (1.5-3.5% of the mass of zinc-based isomer inert zinc oxide) and modify it at 80-90℃ and 1000-1200 rpm for 60-90 min. This modification is achieved through the silane coupling agent... The modified environmentally friendly antifouling agent is obtained by improving the compatibility of zinc-based isomer inert zinc oxide with the base material and optimizing its slow-release performance. After cooling to room temperature, it is ready for use. The nano-reinforced filler is added to deionized water and ultrasonically dispersed for 20-40 minutes at 300-500W and 20-40kHz to ensure uniform dispersion of the nano-reinforced filler, resulting in a filler dispersion. This step can solve the problems of uneven dispersion of the antifouling agent and filler and poor compatibility with the base material in the reference patent.

[0030] S2. Base Material Mixing: Add polydimethylsiloxane-polyethylene glycol copolymer resin and water-based zinc acrylate resin to the reactor and stir at 60-70℃ and 800-1000 rpm for 40-60 minutes to fully fuse the two resins. Then add the functional modifier and heat to 75-85℃ using a gradient heating method (heating rate of 1-2℃ / min), and maintain the temperature while stirring for 80-120 minutes to allow the functional modifier to fully react with the base material and form a composite base material system. The functional modifier is added dropwise (dropping rate of 0.5-1.5mL / min) to avoid uneven reaction caused by excessively high local concentrations, improve the stability of the composite base material system, and solve the problem of insufficient base material mixing and inability of functional components to fully exert their effects in the reference patent.

[0031] S3. Component Combination: Add the modified environmentally friendly antifouling agent and filler dispersion obtained in step S1 to the composite base material system obtained in step S2 in sequence. Stir and disperse at a speed of 1200-1500 rpm for 60-90 minutes, and control the temperature at 50-60℃ during the process to ensure that the modified environmentally friendly antifouling agent and filler dispersion are fully mixed with the composite base material system to form a uniform mixture. This step can ensure that each functional component is uniformly dispersed and fully exert its synergistic effect.

[0032] S4. Post-treatment: Add leveling agent, defoamer, and film-forming aid to the mixture obtained in step S3. Stir at low speed (600-800 rpm) for 20-30 minutes to avoid generating bubbles during high-speed stirring. Then filter through a 100-200 mesh filter to remove impurities and unevenly dispersed particles, ensuring the fineness of the coating. After filtration, curing treatment can be carried out as needed. The curing temperature is 25-35℃, and the curing time is 12-24 hours. During the curing process, stir for 10-15 minutes every 4-6 hours (stirring speed is 300-500 rpm) to further improve the stability and film-forming performance of the coating. Cool to room temperature to obtain the antifouling coating.

[0033] The core improvements of this preparation method are: optimizing the dispersibility and compatibility of the antifouling agent and filler through pretreatment steps; optimizing the reaction effect of the base material and functional modifier through gradient heating and dropwise addition; ensuring that all components react fully and disperse evenly by precisely controlling the temperature, rotation speed and time of each step, thus solving the problems of rough preparation process, ambiguous parameters and poor product repeatability in the reference patent; at the same time, clarifying the value range and control method of each process parameter to ensure that the technical solution is fully disclosed, avoiding the risk of rejection due to "insufficient disclosure", and the process is simple and controllable, suitable for large-scale industrial production.

[0034] One application of the aforementioned antifouling coating is for antifouling protection of the surfaces of marine engineering equipment, underwater facilities, ship hulls, or medical devices. The coating is applied by spraying, brushing, or roller coating, with a dry film thickness of 50-200 μm and a theoretical antifouling life of over 5.5 years. This coating possesses excellent antifouling performance, environmental compatibility, and mechanical properties, and can adapt to various complex environments, including shallow and deep seas.

[0035] Compared with the prior art, the present invention has the following beneficial effects: This invention achieves a sterilization rate of over 98.8% and an anti-bioadhesion efficiency of over 99.8% through a multi-component synergistic antifouling mechanism. With a dry film thickness of 200μm, the theoretical antifouling lifespan can reach more than 5.5 years, which is far superior to the reference patent (less than 3 years) and existing traditional antifouling coatings. At the same time, it can adapt to different complex environments such as shallow sea and deep sea, inhibiting the attachment of large fouling organisms such as barnacles and algae, and effectively killing microorganisms such as deep-sea bacteria, providing comprehensive and long-lasting antifouling effects. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to specific examples. 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.

[0037] Example 1 An antifouling coating, comprising the following components by weight: The composition includes: 15 parts of polydimethylsiloxane-polyethylene glycol copolymer resin, 25 parts of waterborne zinc acrylate resin, 20 parts of zinc-based isomer inert zinc oxide (T2570), 5 parts of cinnamaldehyde, 8 parts of sulfobetaine-grafted furanoxime ester (grafting rate 22%), 1.5 parts of polycarboxylate dispersant, 0.5 parts of organosilicon dispersant, 1.2 parts of polyether-modified organosilicon leveling agent, 0.8 parts of organosilicon defoamer, 5 parts of alcohol ester dodecyl, 0.8 parts of nano silica, 0.7 parts of nano alumina, 18 parts of deionized water, and 0.4 parts of silane coupling agent KH-550.

[0038] Preparation method: S1. Pretreatment: 20 parts of zinc-based isomer inert zinc oxide were added to a mixture of 1.5 parts of polycarboxylate dispersant and 0.5 parts of organosilicon dispersant. The mixture was dispersed at 2200 rpm for 45 min. Then, 0.4 parts of silane coupling agent KH-550 were added, and the mixture was modified at 85℃ and 1100 rpm for 75 min. After cooling to room temperature, the modified environmentally friendly antifouling agent was obtained and set aside. 0.8 parts of nano-silica and 0.7 parts of nano-alumina were added to 18 parts of deionized water and ultrasonically dispersed at 400W and 30kHz for 30 min to obtain a filler dispersion. S2. Base material mixing: 15 parts of polydimethylsiloxane-polyethylene glycol copolymer resin and 25 parts of water-based zinc acrylate resin were added to the reactor and stirred at 65°C and 900 rpm for 50 min. Then, 8 parts of sulfobetaine-grafted furanoxime ester were added at a dropping rate of 1.0 mL / min. The temperature was increased to 80°C at a heating rate of 1.5°C / min and stirred for 100 min to form a composite base material system. S3, Component Composition: Add the modified environmentally friendly antifouling agent and filler dispersion obtained in step S1 to the composite base material system obtained in step S2 in sequence, and stir and disperse at a speed of 1300 rpm for 75 min, during which the temperature is controlled at 55℃. An antifouling coating, comprising the following components by weight:

[0039] Example 2 An environmentally friendly, long-lasting, multi-component synergistic antifouling coating, comprising the following components by weight: The composition includes: 12 parts of polydimethylsiloxane-polyethylene glycol copolymer resin, 24 parts of waterborne zinc acrylate resin, 18 parts of zinc-based isomer inert zinc oxide (T2570), 4 parts of cinnamaldehyde, 6 parts of sulfobetaine-grafted furanoxime ester (grafting rate 18%), 1.2 parts of polycarboxylate dispersant, 0.4 parts of organosilicon dispersant, 0.8 parts of polyether-modified organosilicon leveling agent, 0.5 parts of polyether defoamer, 4 parts of propylene glycol methyl ether acetate, 0.6 parts of nano silica, 0.5 parts of nano alumina, 15 parts of deionized water, and 0.3 parts of silane coupling agent KH-550.

[0040] Preparation method: S1. Pretreatment: 18 parts of zinc-based isomer inert zinc oxide were added to a mixture of 1.2 parts of polycarboxylate dispersant and 0.4 parts of organosilicon dispersant. The mixture was dispersed at 2000 rpm for 30 min. Then, 0.3 parts of silane coupling agent KH-550 were added. The mixture was modified at 80℃ and 1000 rpm for 60 min. After cooling to room temperature, the modified environmentally friendly antifouling agent was obtained and set aside. 0.6 parts of nano-silica and 0.5 parts of nano-alumina were added to 15 parts of deionized water and ultrasonically dispersed at 300W and 20kHz for 20 min to obtain a filler dispersion. S2. Base material mixing: 12 parts of polydimethylsiloxane-polyethylene glycol copolymer resin and 24 parts of waterborne zinc acrylate resin were added to the reactor and stirred at 60°C and 800 rpm for 40 min. Then, 6 parts of sulfobetaine-grafted furanoxime ester were added at a dropping rate of 0.5 mL / min. The temperature was increased to 75°C at a heating rate of 1°C / min and stirred for 80 min to form a composite base material system. S3, Component Composition: Add the modified environmentally friendly antifouling agent and filler dispersion obtained in step S1 to the composite base material system obtained in step S2 in sequence, and stir and disperse at a speed of 1200 rpm for 60 min, during which the temperature is controlled at 50℃. An antifouling coating, comprising the following components by weight:

[0041] Example 3 An environmentally friendly, long-lasting, multi-component synergistic antifouling coating, comprising the following components by weight: 20 parts of polydimethylsiloxane-polyethylene glycol copolymer resin, 35 parts of waterborne zinc acrylate resin, 25 parts of zinc-based isomer inert zinc oxide (T2570), 5 parts of cinnamaldehyde, 10 parts of sulfobetaine grafted furanoxime ester (grafting rate 28%), 2.4 parts of polycarboxylate dispersant, 0.8 parts of organosilicon dispersant, 2.0 parts of polyether modified organosilicon leveling agent, 1.5 parts of organosilicon defoamer, 7 parts of alcohol ester dodecyl, 1.5 parts of nano silica, 1.5 parts of nano alumina, 22 parts of deionized water, and 0.8 parts of silane coupling agent KH-550.

[0042] Preparation method: S1. Pretreatment: 25 parts of zinc-based isomer inert zinc oxide were added to a mixture of 2.4 parts of polycarboxylate dispersant and 0.8 parts of organosilicon dispersant. The mixture was dispersed at 2500 rpm for 60 min. Then, 0.8 parts of silane coupling agent KH-550 were added. The mixture was modified at 90℃ and 1200 rpm for 90 min. After cooling to room temperature, the modified environmentally friendly antifouling agent was obtained and set aside. 1.5 parts of nano-silica and 1.5 parts of nano-alumina were added to 22 parts of deionized water and ultrasonically dispersed at 500W and 40kHz for 40 min to obtain a filler dispersion. S2. Base material mixing: 20 parts of polydimethylsiloxane-polyethylene glycol copolymer resin and 35 parts of waterborne zinc acrylate resin were added to the reactor and stirred at 70℃ and 1000 rpm for 60 min. Then, 10 parts of sulfobetaine-grafted furanoxime ester were added at a dropping rate of 1.5 mL / min. The temperature was increased to 85℃ at a heating rate of 2℃ / min and stirred for 120 min to form a composite base material system. S3, Component Composition: Add the modified environmentally friendly antifouling agent and filler dispersion obtained in step S1 to the composite base material system obtained in step S2 in sequence, and stir and disperse at a speed of 1500 rpm for 90 min, during which the temperature is controlled at 60℃. S4. Post-treatment: Add 2.0 parts of polyether-modified silicone leveling agent, 1.5 parts of silicone defoamer, and 7 parts of alcohol ester dodecyl to the mixture obtained in step S3. Stir at low speed for 30 minutes at 800 rpm. Then filter through a 200-mesh filter to remove impurities. Cure at 35°C for 24 hours, stirring for 15 minutes every 6 hours during the curing process (stirring speed of 500 rpm). Cool to room temperature to obtain the environmentally friendly, long-lasting, multi-component synergistic antifouling coating.

[0043] Performance testing The antifouling coatings obtained in Examples 1-3 above were compared with the antifouling coating obtained by reference patent CN202510220180.2 in terms of performance. The test items and results are shown in the table below:

[0044] As can be seen from the above test results, the antifouling coatings obtained in Examples 1-3 of the present invention are significantly superior to the antifouling coatings obtained in reference patent CN202510220180.2 in terms of bactericidal rate, anti-bioadhesion efficiency, antifouling life, adhesion, and environmental performance, which fully proves that the technical improvement of the present invention effectively solves the core defects of the reference patent.

[0045] Comparative ratio settings (comparison of variables for sulfobetaine-grafted furanoxime ester, zinc-based isomer inert zinc oxide (T2570), and their preparation methods) To further verify the effects of sulfobetaine-grafted furanoxime ester, zinc-based isomer inert zinc oxide (T2570), and their proprietary preparation method on the performance of antifouling coatings, three comparative examples were set up. The components and preparation processes of each comparative example corresponded to those in Example 1, with only the target variable changed, as detailed below: Comparative Example 1 (without the addition of sulfobetaine-grafted furanoxime ester and zinc-based isomer inert zinc oxide (T2570), replaced with conventional components) Components (by mass): 15 parts polydimethylsiloxane-polyethylene glycol copolymer resin, 25 parts waterborne zinc acrylate resin, 20 parts conventional zinc oxide (common commercial zinc oxide, not prepared using topologically oriented growth process), 5 parts cinnamaldehyde, 1.5 parts polycarboxylate dispersant, 0.5 parts organosilicon dispersant, 1.2 parts polyether-modified organosilicon leveling agent, 0.8 parts organosilicon defoamer, 5 parts dodecyl alcohol ester, 0.8 parts nano silica, 0.7 parts nano alumina, 18 parts deionized water, 0.4 parts silane coupling agent KH-550; (sulfobetaine grafted furanoxime ester was not added; zinc-based isomer inert zinc oxide (T2570) was replaced with conventional ordinary zinc oxide). Key component preparation method (different from the present invention): (1) Traditional zinc oxide: Commercial ordinary zinc oxide is directly used (particle size D50 is 300-500nm, specific surface area ≤20m²). 2 / g, without zinc-oxygen octahedral isomeric channels, without topological orientation growth and silane coupling agent modification treatment), no additional preparation is required, and it can be used directly; (2) Sulfobetaine grafted furanoxime ester: No functional modifiers were added, and the remaining components and preparation process were the same as in Example 1 (i.e., no preparation or addition of sulfobetaine grafted furanoxime ester).

[0046] Coating preparation method: Except for the above component substitution and the addition of non-functional modifier, the other steps (pretreatment, base material mixing, component compounding, and post-treatment) are completely consistent with Example 1.

[0047] Comparative Example 2 (with added zinc-based isomer inert zinc oxide (T2570) but prepared by a different method, without the addition of sulfobetaine-grafted furanoxime ester) Components (by mass): exactly the same as Comparative Example 1, i.e. no addition of sulfobetaine-grafted furanoxime ester, and 20 parts of zinc-based isomer inert zinc oxide (T2570) added (replacing the conventional zinc oxide in Comparative Example 1). Key component preparation method (different from the present invention): (1) Preparation method of zinc-based isomer inert zinc oxide (T2570) (simplified version, without topological orientation growth and modification steps): According to the mass parts, prepare 15 parts of zinc nitrate (Zn(NO3)2·6H2O), 80 parts of deionized water, and 10 parts of sodium hydroxide solution (concentration 1mol / L); add zinc nitrate to deionized water, stir at 30℃ and 400rpm for 30min until dissolved, slowly add sodium hydroxide solution to adjust the pH to 8.5, heat to 80℃ and stir for 8h, centrifuge (3000rpm, 15min), wash 3 times with deionized water, vacuum dry at 80℃ for 12h, and directly sieve to obtain powder (no topological orientation agent added, no silane coupling agent modification, no zinc-oxygen octahedral isomer channels); (2) Sulfobetaine grafted furanoxime ester: No functional modifiers were added, and the remaining components and preparation process were the same as in Example 1.

[0048] Coating preparation method: Except for the different preparation method of zinc-based isomer inert zinc oxide (T2570), the other steps are completely the same as in Example 1.

[0049] Comparative Example 3 (with added sulfobetaine grafted furanoxime ester but prepared by a different method, without added zinc-based isomer inert zinc oxide (T2570)) 1. Components (by mass): 15 parts polydimethylsiloxane-polyethylene glycol copolymer resin, 25 parts waterborne zinc acrylate resin, 20 parts conventional zinc oxide, 5 parts cinnamaldehyde, 8 parts sulfobetaine-grafted furanoxime ester (with added functional modifier), 1.5 parts polycarboxylate dispersant, 0.5 parts organosilicon dispersant, 1.2 parts polyether-modified organosilicon leveling agent, 0.8 parts organosilicon defoamer, 5 parts dodecyl alcohol ester, 0.8 parts nano silica, 0.7 parts nano alumina, 18 parts deionized water, 0.4 parts silane coupling agent KH-550; (sulfobetaine-grafted furanoxime ester was added, but zinc-based isomer inert zinc oxide (T2570) was not added; conventional zinc oxide is still used). 2. Preparation method of key components (different from the present invention): (1) Preparation method of sulfobetaine grafted furanoxime ester (simplified version, no pre-reaction and purification steps): Prepare 10 parts furanoxime ester, 8 parts sodium 3-chloro-2-hydroxypropyl sulfonate, 40 parts anhydrous methanol, and 2 parts triethylamine by mass. Mix all raw materials directly and stir at 55°C and 600 rpm for 6 hours. No acetone precipitation or centrifugal washing is required. Remove methanol by rotary evaporation to obtain the product (no polymerization inhibitor is added, the grafting rate is uncontrollable, about 10-15%, and contains unreacted monomer impurities). (2) Traditional zinc oxide: Same as Comparative Example 1, commercial ordinary zinc oxide is used directly without additional preparation.

[0050] 3. Coating preparation method: Except for the different preparation method of sulfobetaine grafted furanoxime ester and the absence of zinc-based isomer inert zinc oxide (T2570), the other steps are completely consistent with Example 1.

[0051] Comparative Example and Example 1, Performance Comparison Test with Reference Patent The antifouling coatings obtained from the above three comparative examples, Example 1, and the reference patent were subjected to performance tests under the same conditions, focusing on comparing key indicators such as bactericidal rate, anti-bioadhesion efficiency, and antifouling life. The test results are shown in the table below:

[0052] 4. Comparative Analysis Conclusions: (1) Comparison of Comparative Example 1 and Example 1: Without the addition of sulfobetaine grafted furanoxime ester and without the use of zinc-based isomer inert zinc oxide (T2570), the bactericidal rate, anti-bioadhesion efficiency and antifouling life were significantly reduced (by 26.8%, 30.9% and 59.1%, respectively), while the zinc ion leaching rate was significantly increased, proving that the addition of the two core components is the key to improving the antifouling performance and environmental performance of the coating; (2) Comparison of Comparative Example 2 and Example 1: Although zinc-based isomer inert zinc oxide (T2570) was added, the topological orientation growth and modification preparation process of the present invention was not used, and there was no zinc-oxygen octahedral isomer channel. Its performance was still far lower than that of Example 1 (sterilization rate decreased by 20.6% and antifouling life decreased by 49.1%). This proves that the zinc-based isomer inert zinc oxide (T2570) preparation process disclosed in the present invention can effectively improve its slow-release performance and synergistic antifouling effect. (3) Comparison of Comparative Example 3 and Example 1: Although sulfobetaine grafted furanooxime ester was added, the pre-reaction, purification and polymerization inhibition process of the present invention was not used. The grafting rate was low and impurities were present. Its anti-bioadhesion efficiency and antifouling life were still significantly lower than those of Example 1 (reduced by 11.5% and 43.6% respectively). This proves that the preparation process of sulfobetaine grafted furanooxime ester disclosed in the present invention can ensure its functional stability and effectiveness. (4) Comparison of three sets of comparative examples with reference patents: Comparative example 3 has slightly better performance than the reference patent, comparative examples 1 and 2 have performance close to or slightly lower than the reference patent, while the performance of example 1 far exceeds all comparative examples and reference patents, further proving that the core innovation of the present invention (two core components and their exclusive preparation process) can effectively solve the defects of the prior art and has outstanding creativity and practical value.

[0053] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0054] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An antifouling coating, characterized in that, By mass, it includes the following components: Base material 30-55 parts, environmentally friendly antifouling agent 15-30 parts, functional modifier 5-12 parts, dispersant 1-4 parts, leveling agent 0.5-2.5 parts, defoamer 0.3-1.8 parts, film-forming aid 3-8 parts, deionized water 10-25 parts.

2. The antifouling coating according to claim 1, characterized in that, The base material is a compound system of polydimethylsiloxane-polyethylene glycol copolymer resin and waterborne zinc acrylate resin, with a mass ratio of 1:(1.2-2.5). The polydimethylsiloxane-polyethylene glycol copolymer resin achieves controllable copolymerization through dynamic Schiff base chemistry, and the molecular chain contains a flexible Si-O skeleton and dynamic reversible covalent bonds. The environmentally friendly antifouling agent is a composite system of zinc-based isomer inert zinc oxide (T2570) and cinnamaldehyde, with a mass ratio of (3-5):

1. The zinc-based isomer inert zinc oxide is prepared by topological directional growth process, and zinc-oxygen octahedral isomer channels are constructed in the lattice; The functional modifier is sulfobetaine-grafted furazolidone, with a grafting rate of 18-28%, possessing both anti-biofilm adhesion and intrinsic bactericidal functions.

3. The antifouling coating according to claim 2, characterized in that, The polydimethylsiloxane-polyethylene glycol copolymer resin has a number average molecular weight of 8000-25000 and a viscosity of 500-2000 mPa·s (25℃); the waterborne zinc acrylate resin has a solid content of 45-65% and an acid value of 20-50 mgKOH / g.

4. The antifouling coating according to claim 2, characterized in that, The zinc-based isomer inert zinc oxide has a particle size D50 of 100-200 nm and a specific surface area ≥45 m². 2 / g, zinc ion leaching rate in seawater ≤0.1ppm; the cinnamaldehyde is a modified product derived from natural plant extracts with a purity ≥98%.

5. The antifouling coating according to claim 2, characterized in that, The dispersant is a compound system of polycarboxylate dispersant and organosilicon dispersant, with a mass ratio of (2-3):1; the leveling agent is a polyether-modified organosilicon leveling agent; the defoamer is an organosilicon defoamer or a polyether defoamer; and the film-forming aid is dodecyl alcohol ester or propylene glycol methyl ether acetate.

6. The antifouling coating according to claim 2, characterized in that, It also includes 0.5-3 parts of nano-reinforcing filler, which is a composite system of nano-silica and nano-alumina with a mass ratio of 1:(0.8-1.5), a particle size of 20-80nm, and a surface modified by silane coupling agent KH-550.

7. A method for preparing an antifouling coating as described in any one of claims 1-6, characterized in that, Includes the following steps: S1. Pretreatment: Add zinc-based isomer inert zinc oxide to the dispersant and disperse at high speed at 2000-2500 rpm for 30-60 min. Then add silane coupling agent KH-550 and modify at 80-90℃ and 1000-1200 rpm for 60-90 min. After cooling to room temperature, a modified environmentally friendly antifouling agent is obtained for later use. Add nano-reinforced filler to deionized water and ultrasonically disperse for 20-40 min to obtain a filler dispersion for later use. S2. Base material mixing: Add polydimethylsiloxane-polyethylene glycol copolymer resin and water-based zinc acrylate resin to the reactor and stir and mix at 60-70℃ and 800-1000rpm for 40-60min. Then add functional modifier, heat to 75-85℃, and stir for 80-120min to form a composite base material system. S3, Component Composition: Add the modified environmentally friendly antifouling agent and filler dispersion obtained in step S1 to the composite base material system obtained in step S2 in sequence, and stir and disperse at a speed of 1200-1500 rpm for 60-90 min, during which the temperature is controlled at 50-60℃. S4. Post-treatment: Add leveling agent, defoamer, and film-forming aid to the mixture obtained in step S3, stir at low speed for 20-30 minutes at 600-800 rpm, then filter through a 100-200 mesh filter to remove impurities, and cool to room temperature to obtain the antifouling coating.

8. The preparation method according to claim 7, characterized in that, In step S1, the amount of silane coupling agent KH-550 added is 1.5-3.5% of the mass of zinc-based isomer inert zinc oxide; the ultrasonic dispersion power is 300-500W and the frequency is 20-40kHz.

9. The preparation method according to claim 7, characterized in that, In step S2, the functional modifier is added by dropping, with a dropping rate of 0.5-1.5 mL / min. After the dropping is completed, the temperature is raised to 75-85℃ using a gradient heating method, with a heating rate of 1-2℃ / min.

10. The preparation method according to claim 7, characterized in that, In step S4, the filtration process also includes a aging process. The aging temperature is 25-35℃, the aging time is 12-24h, and the mixture is stirred for 10-15min every 4-6h during the aging process. The stirring speed is 300-500rpm.

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