Waterborne eco-friendly anti-corrosion antifouling paint under marine environment as well as preparation method and application of waterborne eco-friendly anti-corrosion antifouling paint

Abstract

The invention belongs to the technical field of marine antifouling and anticorrosive coatings, and particularly discloses a waterborne eco-friendly corrosion-resistant and antifouling coating for a marine environment as well as a preparation method and application of the waterborne eco-friendly corrosion-resistant and antifouling coating. The coating comprises a component A and a component B, the component A comprises waterborne epoxy modified organic silicon resin, KH560 modified aluminum zinc polyphosphate, KH560 modified ZnS coated SiO2, a functional aid and deionized water, and the component B is a mixture of a waterborne modified amine curing agent and a silane coupling agent KH560; the functional auxiliary agent comprises a flash rust inhibitor, an organic silicon defoamer, a dispersing agent and a base material wetting agent. The coating has the advantages of low VOC emission, strong anti-fouling and anti-corrosion synergism, excellent mechanical properties, good long-term service stability, simple preparation process, controllable cost and the like, and overcomes the defects that the environmental protection property and high performance of the existing marine anti-fouling and anti-corrosion coating are difficult to consider, the preparation process is complicated, the long-acting stability is insufficient, the cost is high and the like.

Description

Technical Field

[0001] This invention relates to the field of marine antifouling and anticorrosion coatings, specifically to a water-based eco-friendly corrosion-resistant and antifouling coating for marine environments, its preparation method, and its application. Background Technology

[0002] Since the beginning of the 21st century, the marine engineering equipment and shipping industries have experienced rapid development, becoming a core support for global trade and marine resource development. According to industry statistics, as of 2023, the global marine engineering equipment market exceeded US$200 billion, and ships accounted for over 70% of global freight volume annually. The stable operation of marine facilities is crucial for the smooth functioning of the global economic chain. However, the high salinity, high humidity, and rich microbial communities of the marine environment make marine facilities highly susceptible to fouling organisms and metal corrosion. Large fouling organisms such as barnacles and oysters increase ship drag; it is estimated that for every 1mm increase in fouling thickness, ship fuel consumption will increase by 5%–10%, while sulfate-reducing bacteria and iron bacteria accelerate the corrosion of metal substrates, shortening the service life of facilities.

[0003] In traditional marine antifouling and corrosion prevention methods, antifouling coatings containing heavy metals once dominated. These coatings inhibit the growth of fouling organisms by slowly releasing heavy metal ions. Among them, coatings containing cuprous oxide are still widely used in small and medium-sized ships and simple marine facilities due to their low cost and long antifouling period. However, with the tightening of environmental regulations such as the International Convention for the Prevention of Pollution from Ships (MARPOL), the harm of heavy metal ions to marine ecosystems has gradually become apparent—excessive copper ions can lead to phytoplankton death and fish liver damage, and some sea areas have experienced local ecological imbalance due to the long-term use of copper-containing coatings. At the same time, marine engineering is expanding into special areas such as the deep sea and polar regions, and the antifouling stability of traditional coatings under low temperature and high pressure environments has decreased significantly, making it difficult to meet the requirements of long-term service. Developing new antifouling and corrosion prevention technologies that are "environmentally friendly and high-performance" has become an industry consensus.

[0004] Currently, industry research mainly focuses on two types of new coatings: one is "fouling release" coatings, which use silicone resins and fluoropolymers as the matrix and reduce the adhesion of fouling organisms through their low surface energy (usually below 25mN / m), thus achieving an "easy-to-clean" effect; the other is "environmentally friendly" water-based coatings, which use water as the dispersion medium to replace traditional organic solvents, reducing VOC (volatile organic compound) emissions by more than 60%, meeting environmental protection and construction safety requirements. However, both types of coatings still have significant shortcomings: Fluoropolymer coatings, although having extremely low surface energy, rely on fluorinated solvents for dissolution, which is not only costly, but also some fluorinated monomers have environmental durability, which does not conform to the long-term environmental protection trend; Organosilicon resin coatings have weak mechanical properties, and the coating is prone to cracking and peeling, making it difficult to adapt to the dynamic service environment of marine facilities; Existing water-based antifouling coatings mostly rely on a single physical antifouling or antibacterial mechanism, with poor synergy between antifouling and anticorrosion, and some products still have VOC content higher than 50g / L, or rely on toxic co-solvents to improve film-forming properties, making it difficult to balance eco-friendliness and long-term service requirements.

[0005] Patent CN110452596B discloses a silicone-modified zinc acrylic / zinc pyridine thione composite antifouling coating. Based on a water-based system, it achieves an environmental protection standard of VOC emissions below 100g / L. The silicone modification imparts a static water contact angle of 115° to the coating, significantly improving its resistance to marine biofouling. However, this coating uses a composite antifouling system of zinc acrylic and zinc pyridine thione, and the synergistic dispersion of the two zinc salts in the water-based emulsion is difficult to control. Uneven local concentrations can easily lead to fluctuations in the antifouling effect. Furthermore, while the introduction of silicone segments increases the low surface energy, it also affects the interfacial bonding between the coating and the metal substrate. Long-term immersion in the ocean poses a risk of decreased adhesion. Patent CN113698855B proposes an acrylic / organosilicon nanocomposite modified waterborne polyurethane marine antifouling coating. It constructs a dual antifouling mechanism of "low surface energy + micro-nano structure" through block polysiloxane polyurethane prepolymer, which extends the antifouling effect to more than 5 years. The room temperature curing process simplifies the construction process. However, the introduction of nanomaterials increases the technical difficulty of stable dispersion of the emulsion. Nanoparticle agglomeration is prone to occur in large-scale production. At the same time, there is still room for improvement in the corrosion resistance of waterborne polyurethane substrate in high salt spray marine environment. After long-term use, the problem of microcrack propagation in the coating may occur.

[0006] In summary, existing marine antifouling and anticorrosion coatings generally suffer from problems such as difficulty in simultaneously achieving environmental friendliness and synergistic antifouling and anticorrosion performance, poor compatibility and easy aggregation of inorganic fillers with water-based resins, and insufficient long-term effectiveness due to a single antibacterial mechanism. These issues fail to meet the demands of deep-sea engineering and green shipping for low VOC emissions, high corrosion resistance, and long antifouling cycles. Developing a marine coating that combines low VOC emissions, excellent antifouling and anticorrosion performance, simple preparation process, and low cost to meet the urgent needs of deep-sea engineering and green shipping has become a current research hotspot and core challenge in the field of marine materials. Summary of the Invention

[0007] This invention aims to overcome the shortcomings of existing marine antifouling and anticorrosion coatings, such as "difficulty in balancing environmental protection and high performance", "complex preparation process", "insufficient long-term stability" and "high cost". It provides a marine antifouling and anticorrosion coating with low VOC emissions, strong antifouling and anticorrosion synergy, excellent mechanical properties, simple preparation process and controllable cost, as well as the preparation method and application of the coating, to meet the long-term service requirements of deep-sea engineering equipment, ships, marine observation equipment and other scenarios, while achieving zero pollution to the marine ecological environment.

[0008] To achieve the above objectives, the specific technical solution adopted by the present invention is as follows:

[0009] In a first aspect, the present invention provides a water-based eco-friendly corrosion-resistant and antifouling coating for marine environments, comprising component A and component B. Component A comprises water-based epoxy-modified silicone resin, KH560-modified aluminum zinc polyphosphate, KH560-modified ZnS@SiO2 core-shell structure filler, functional additives, and deionized water. Component B is a mixture of water-based modified amine curing agent and silane coupling agent KH560. The functional additives include anti-flash rust agent, silicone defoamer, dispersant, and substrate wetting agent.

[0010] The preparation principle of the composite modified filler (KH560 modified aluminum zinc polyphosphate + KH560 modified ZnS@SiO2) used in this invention is as follows:

[0011] KH560 modified aluminum zinc polyphosphate (KH560-ZAP): Using anhydrous ethanol-deionized water as solvent, the pH is adjusted to 3-5 to promote the hydrolysis of KH560 to generate silanol groups, which then undergo a dehydration condensation reaction with the hydroxyl groups on the surface of aluminum zinc polyphosphate (ZAP), thereby achieving chemical grafting of KH560 on the ZAP surface and improving the compatibility between the filler and the resin matrix.

[0012] KH560 modified ZnS@SiO2 core-shell structure filler: Using anhydrous ethanol-deionized water as solvent and concentrated ammonia to adjust the pH to 8.5-10.0, tetraethyl orthosilicate is hydrolyzed and condensed on the ZnS surface via a sol-gel method to form a 15-25 nm thick SiO2 shell. Grafting modification is then achieved by the condensation of alkoxy groups of KH560 with the hydroxyl groups of the SiO2 shell, thus avoiding ZnS aggregation and regulating ZnS content. 2+ Sustained-release rate.

[0013] This invention uses water-based epoxy-modified silicone resin as the main raw material, which is green and environmentally friendly and can be purchased directly. It is combined with a water-based modified amine curing agent to achieve room temperature curing. This curing agent was selected by comparing the performance of various amine curing agents and can effectively eliminate the problems of slow curing speed or easy yellowing of coatings caused by conventional amine curing agents. It achieves surface drying in 1 day and complete drying in 3 days after coating, which greatly reduces the process difficulty and production cost. The silane coupling agent KH560 is used to improve the compatibility between the modified filler and the resin, while enhancing the adhesion between the coating and the substrate, further reducing the process difficulty and production cost.

[0014] This invention selects a ZnS@SiO2 core-shell structure and KH560 modified aluminum zinc polyphosphate as a composite functional filler: the ZnS core of the ZnS@SiO2 core-shell filler has a dual antibacterial mechanism, on the one hand by slow-release Zn 2+ On the one hand, it disrupts bacterial enzyme systems and metabolic balance, inhibiting bacterial reproduction; on the other hand, it can stimulate the production of reactive oxygen species (ROS), which damage bacterial cell membrane structures through oxidation, leading to bacterial DNA damage and inactivation; while the SiO2 shell can both prevent ZnS particle aggregation and ensure uniform dispersion of antibacterial components, and regulate Zn 2+ The release rate and ROS generation efficiency extend the antibacterial effect, and the surface hydroxyl groups can enhance the interaction with the matrix, improving the stability of the filler. Simultaneously, the KH560 modified aluminum-zinc polyphosphate filler chemically bonds its own hydroxyl groups through the epoxy groups of the coupling agent, while the alkoxy groups at the other end can tightly bind with the waterborne resin matrix. This not only further optimizes the dispersibility of the filler in the resin, solving the problem of poor compatibility between traditional inorganic fillers and organic matrices, but also enhances the coating's protective effect on the substrate by relying on the corrosion-inhibiting properties of aluminum-zinc polyphosphate, reducing seawater corrosion of the substrate, and forming a synergistic effect of "antibacterial + corrosion resistance" with ZnS@SiO2. Based on this, the modified composite filler is integrated with the waterborne resin system, enabling the coating to achieve dynamic antifouling by relying on the low surface energy of the resin itself, and also through the ZnS... 2+The slow-release and synergistic effects of ROS (reactive oxygen species) and zinc aluminum polyphosphate construct a multi-layered static antibacterial barrier. By integrating dynamic antifouling and multiple static antibacterial functions, this invention ultimately produces an eco-friendly composite antibacterial and antifouling coating. This coating exhibits excellent antifouling, antibacterial, and corrosion-resistant effects in various marine scenarios, including static immersion and dynamic water flow, effectively overcoming the shortcomings of traditional coatings such as a single antibacterial mechanism, short duration, and insufficient resistance to seawater corrosion.

[0015] Preferably, component A comprises, by mass percentage: 30-45% waterborne epoxy-modified silicone resin, 10-14% KH560-modified aluminum zinc polyphosphate, 1-3% KH560-modified ZnS@SiO2, 0.1-0.5% anti-flash rust agent, 0.1-0.5% silicone defoamer, 0.2-1% dispersant, 0.1-0.5% substrate wetting agent, and the balance being deionized water; in component B, the mass ratio of waterborne modified amine curing agent to silane coupling agent KH560 is (10-15):1.

[0016] Furthermore, in component A, the content of KH560 modified aluminum zinc polyphosphate is 12wt%, and the content of KH560 modified ZnS@SiO2 is 2wt%. At this point, the coating has an antifouling efficiency of over 95%, a neutral salt spray corrosion resistance of over 1000h, and the best corrosion resistance and antibacterial properties.

[0017] Preferably, the mass ratio of component A to component B is (1.8 to 2.2):1.

[0018] Preferably, the flash rust inhibitor is type A01; the silicone defoamer is type 1050; the dispersant is type SN-5040 water-based dispersant; and the substrate wetting agent is type OT-75.

[0019] Preferably, the waterborne epoxy-modified silicone resin has an epoxy value of 0.06 to 0.16, a solid content of 50 ± 2%, and a viscosity of 100 to 300 mPa•s at 25°C; the waterborne modified amine curing agent has an active hydrogen equivalent of 330 and a solid content of 50 ± 1%.

[0020] Secondly, the present invention provides a method for preparing the above-mentioned water-based eco-friendly corrosion-resistant and antifouling coating for marine environments, comprising the following steps:

[0021] S1. KH560-ZAP and KH560 modified ZnS@SiO2 are mixed and added to deionized water, and ultrasonically vibrated at 30-60 kHz for 30-60 min to form a modified filler dispersion.

[0022] S2. Add waterborne epoxy-modified silicone resin to a mixing tank, then add anti-flash rust agent, silicone defoamer, dispersant, and substrate wetting agent in sequence. Shear and stir at a low speed of 400-600 r / min for 15-25 min. Then add the modified filler dispersion of S1, add zirconium beads as grinding media, and grind and stir at a high speed of 2000-3000 r / min for 30-50 min. Control the particle size D90 of the system after grinding to be ≤5 μm. After filtration, obtain component A.

[0023] S3. Mix the water-based modified amine curing agent and the silane coupling agent KH560 in a certain proportion, and stir at 500-800 r / min for 8-12 min to obtain component B;

[0024] S4. Mix component A and component B in proportion, and shear at a low speed of 200-400 r / min for 5-10 min until the mixture is uniform. Then let it stand and mature for 15-25 min before coating.

[0025] Thirdly, this invention provides the application of the aforementioned water-based eco-friendly corrosion-resistant and antifouling coating in marine environments in the field of shipbuilding and marine engineering. Specifically, the application involves coating the coating on key components such as ship hulls, offshore platform load-bearing structures, port facilities, and the inner walls of seawater pipelines. This effectively enhances the antifouling performance and resistance to marine organism adhesion on the surfaces of these facilities, reducing or even avoiding problems such as surface corrosion and increased water flow resistance caused by marine organism adhesion. Consequently, it reduces the frequency of regular shutdowns for maintenance and cleaning or underwater professional cleaning, effectively improving ship navigation efficiency and the service life of marine engineering facilities, and significantly reducing operation and maintenance costs.

[0026] Preferably, the coating application method is brushing, rolling, or spraying; wherein the spraying pressure is 0.3-0.5 MPa and the spraying distance is 20-30 cm; the coating thickness after curing is 50-200 μm, which can achieve antifouling and anticorrosion effect for 2-3 years. When the thickness is less than 50 μm, the antifouling period is shortened to less than 6 months, and when it is greater than 200 μm, the coating is prone to cracking.

[0027] Preferably, the coating operation is carried out at room temperature, and the coating achieves surface dryness in 1 day and complete dryness in 3 days.

[0028] The present invention has the following beneficial effects:

[0029] This invention solves the problem of inorganic filler dispersion through KH560 double modification and core-shell structure design, and fills the gap in the existing technology of "anti-fouling-anti-corrosion" synergy through "corrosion-resistant filler + antibacterial filler".

[0030] This invention successfully prepares a high-performance waterborne antifouling and corrosion-resistant composite coating through a synergistic effect of gentle ultrasonic dispersion, efficient mechanical stirring, and fine grinding. This coating not only possesses excellent hydrophobic properties, significantly reducing direct contact between seawater and the substrate surface, but also exhibits superior corrosion resistance in complex marine environments. Even after prolonged seawater immersion, the coating structure remains stable, and its performance parameters do not show a significant decline, effectively inhibiting the attachment and growth of algae, shellfish, and various microorganisms.

[0031] This invention successfully provides a pollution-free antifouling and anticorrosive coating with excellent mechanical properties: the coating prepared according to the formula and method of this invention can meet the antifouling requirements in marine environments, with an antifouling efficiency of over 95% (targeting marine fouling organisms such as sulfate-reducing bacteria); it possesses excellent mechanical and corrosion resistance properties due to the addition of KH560 modified aluminum zinc polyphosphate and KH560 modified ZnS@SiO2 filler; the coating has a pencil hardness ≥2H (GB / T 6739-2006), adhesion grade 0 (GB / T 9286-1998), impact resistance ≥50cm (GB / T 1732-1993), flexibility ≤1 mm (GB / T 1731-1993), and neutral salt spray corrosion resistance of over 1000h (ASTM B117 standard); moreover, the VOC content of the coating is ≤50g / L, meeting environmental protection standards (below 100g / L).

[0032] Furthermore, this invention enriches the material selection range and technical direction of water-based corrosion-resistant and antifouling coatings. Its preparation process does not use toxic or harmful solvents, making the entire process green and pollution-free. The operation steps are simple and easy to control, which is conducive to large-scale industrial production. Simultaneously, this coating exhibits good adhesion and compatibility with various substrates such as steel, aluminum, and composite materials, making it suitable for a wide range of scenarios. It has significant application value and broad market prospects in shipbuilding, offshore platform construction, and seawater desalination projects. Moreover, the application method is flexible, and the coating thickness is stable and controllable after curing, ensuring excellent antifouling and anti-corrosion effects and long-term service stability during operation. Attached Figure Description

[0033] Figure 1 Scanning electron microscope image of KH560 modified aluminum zinc polyphosphate used in the waterborne corrosion-resistant and antifouling coating prepared in Example 1.

[0034] Figure 2 Scanning electron microscope (SEM) image of ZnS@SiO2 modified with KH560 used in the waterborne corrosion-resistant and antifouling coating prepared in Example 1.

[0035] Figure 3 XRD patterns of aluminum zinc polyphosphate modified with KH560 filler used in the water-based corrosion-resistant and antifouling coating prepared in Example 1 before and after modification.

[0036] Figure 4 XRD patterns of ZnS@SiO2 modified with filler KH560 before and after modification used in the water-based corrosion-resistant and antifouling coating prepared in Example 1.

[0037] Figure 5 Scanning electron microscope image of the water-based corrosion-resistant and antifouling coating film prepared in Example 1.

[0038] Figure 6 The image shows a laser confocal image of the water-based corrosion-resistant and antifouling coating film prepared in Example 1.

[0039] Figure 7 Electrochemical polarization curves of the water-based corrosion-resistant and antifouling coating film prepared in Example 1, the ZnS@SiO2 coating without KH560 modification, the aluminum zinc polyphosphate coating without KH560 modification and the ZnS@SiO2 coating with KH560 modification, and the uncoated metal substrate are denoted as K-ZAP / ZnS@K-SiO2 / WEMSR, K-ZAP / WEMSR, WEMSR, and tinplate, respectively.

[0040] Figure 8 The water contact angle is shown in Example 1 compared to the waterborne antifouling coating prepared using other silane coupling agents.

[0041] Figure 9 Fluorescence images of the aqueous antifouling coating prepared in Example 1, the coating prepared using unmodified dual fillers, and the uncoated metal substrate immersed in sulfate-reducing bacteria for 7 days. Detailed Implementation

[0042] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0043] The characterization performance testing methods involved in the following embodiments and comparative examples are as follows:

[0044] 1. Corrosion performance test: Potentiodynamic polarization test was performed on an electrochemical workstation. The sample size was 10×10×1mm.

[0045] 2. Film morphology observation: The film morphology of the coating was observed under scanning electron microscopy and confocal microscopy.

[0046] 3. Observation of antifouling morphology of sulfate-reducing bacteria: The distribution of sulfate-reducing bacteria on the coating surface after 7 days of immersion was photographed using a fluorescence microscope. The sample size was 10×10×1mm.

[0047] 4. Hydrophobicity test: The hydrophobicity of the coating was tested using a water contact angle tester.

[0048] 5. Phase analysis of packing material: X-ray diffraction was used to analyze the phases of the packing material before and after modification.

[0049] 6. Mechanical property tests: coating pencil hardness (GB / T 6739-2006), adhesion (GB / T 9286-1998), impact resistance (GB / T 1732-1993), flexibility (GB / T 1731-1993).

[0050] Example 1

[0051] I. Preparation of Modified Fillers

[0052] Preparation of KH560 modified aluminum zinc polyphosphate (KH560-ZAP): 80 mL of anhydrous ethanol and 20 mL of deionized water were accurately measured and placed in a three-necked flask and magnetically stirred until homogeneous. Acetic acid solution was added dropwise through a dropping funnel to adjust the pH of the system to 3-5. 3 mL of KH560 silane coupling agent was added, and the mixture was stirred at 50 °C for 3 h to hydrolyze. Subsequently, 3 g of ZAP powder was added, and the mixture was stirred continuously at 40 °C for 2 h. The filter cake was collected by vacuum filtration, dried under vacuum at 110 °C for 5 h, and KH560-ZAP was obtained after cooling.

[0053] Preparation of KH560 modified ZnS@SiO2 core-shell structure filler (sol-gel method): Prepare 100 mL of anhydrous ethanol-deionized water mixed solvent at a volume ratio of 9:1, transfer to a three-necked flask and preheat; adjust the pH to 8.5-10.0 by adding concentrated ammonia dropwise, and stir for 10-15 min; add 10 g of ultrasonically dispersed nano ZnS powder, continue ultrasonication for 30 min + magnetic stirring for 1 h; add 5 mL of tetraethyl orthosilicate dropwise through a constant pressure dropping funnel at a rate of 1-2 drops / s, and stir at 30-40℃ for 4-6 h; add 3 g of KH560, maintain the temperature and continue the reaction for 2-3 h; centrifuge at 8000-10000 r / min for 10-15 min, collect the precipitate, wash with anhydrous ethanol and deionized water alternately 3-4 times, vacuum dry at 60-80℃ for 12-24 h, and grind to obtain KH560 modified ZnS@SiO2.

[0054] II. Preparation of Corrosion-Resistant and Antifouling Coatings

[0055] A water-based, eco-friendly, corrosion-resistant, and antifouling coating for marine environments comprises component A and component B, wherein the mass ratio of component A to component B is 2:1. Component A comprises: 35 wt% water-based epoxy-modified silicone resin (SH-960 type), 12 wt% KH560-modified aluminum zinc polyphosphate, 2 wt% KH560-modified ZnS@SiO2, 0.3 wt% flash rust inhibitor (A01 type), 0.3 wt% silicone defoamer (1050 type), 0.5 wt% dispersant (SN-5040 type), 0.3 wt% substrate wetting agent (OT-75 type), and the balance being deionized water. Component B is a mixture of water-based modified amine curing agent (DY-175 type) and silane coupling agent KH560 in a mass ratio of 12:1.

[0056] Weigh the raw materials according to the above formula, and prepare a water-based eco-friendly corrosion-resistant and antifouling coating for marine environments according to the following steps:

[0057] S1. KH560 modified aluminum zinc polyphosphate and KH560 modified ZnS@SiO2 were mixed and added to deionized water, and ultrasonically vibrated at 40kHz for 45min to form a modified filler dispersion.

[0058] S2. Add waterborne epoxy-modified silicone resin to a mixing tank, then add anti-flash rust agent, silicone defoamer, dispersant, and substrate wetting agent in sequence. Shear and stir at 500 r / min for 20 min. Then add the modified filler dispersion from S1, add zirconium beads as grinding media, and grind and stir at 2500 r / min for 40 min. Control the particle size D90 of the system after grinding to be ≤5 μm. After filtration, obtain component A.

[0059] S3. Mix the water-based modified amine curing agent and the silane coupling agent KH560 in a certain proportion, stir at 600 r / min for 10 min to obtain component B;

[0060] S4. Mix component A and component B in the specified ratio, shear at a low speed of 300 r / min for 8 minutes until uniformly mixed, then let stand and mature for 20 minutes before coating. In this specific embodiment, spraying is used for coating. After spraying, the coating achieves surface dryness in 1 day and complete dryness in 3 days at room temperature.

[0061] III. Characterization properties of modified fillers and corrosion-resistant and antifouling coatings

[0062] Figure 1 Scanning electron microscope (SEM) images of KH560-modified aluminum zinc polyphosphate are shown. The surface morphology of the modified filler was observed by SEM, showing that the filler particles were uniformly dispersed without obvious agglomeration. This indicates that KH560 modification effectively improves the dispersibility of the filler, providing a uniform antibacterial and corrosion-resistant foundation for subsequent coatings.

[0063] Figure 2 This is a scanning electron microscope (SEM) image of the KH560-modified ZnS@SiO2 core-shell structure, revealing the microstructure of the core-shell filler. The ZnS core is completely encapsulated by a SiO2 shell, with the shell thickness controlled within the range of 15–25 nm, which helps to slow the release of Zn. 2+ And enhance stability.

[0064] Figure 3 X-ray diffraction analysis was performed on the phase changes of KH560 modified aluminum zinc polyphosphate before and after modification. The XRD pattern showed that the crystal structure of the filler remained intact after modification and the coupling agent was successfully grafted, which confirmed the effectiveness of chemical modification and provided phase evidence for the corrosion resistance of the coating.

[0065] Figure 4 The XRD patterns of ZnS@SiO2 modified with KH560 before and after modification are shown. By comparing the phase spectra, it can be seen that the SiO2 shell deposition did not change the crystal structure of the ZnS core. At the same time, the appearance of silane characteristic peaks after modification verifies the successful grafting of KH560.

[0066] Figure 5 The image shows a scanning electron microscope (SEM) image of a water-based corrosion-resistant and antifouling coating film. The film morphology of the coating is observed, showing that the coating surface is dense and smooth, without cracks or pores, and the filler is evenly distributed, which improves the mechanical integrity of the coating.

[0067] Figure 6 The laser confocal microscope image of the coating was used to further analyze the three-dimensional surface structure of the coating, which showed that the micro-nano structure contributes to the hydrophobic and antifouling properties, consistent with the dynamic antifouling mechanism.

[0068] To further verify the actual service adaptability of the coating, its mechanical properties were systematically tested, and the results are shown in Table 1:

[0069] Table 1

[0070]

[0071] Table 1 shows that the coating of the present invention performs excellently in terms of hardness, adhesion, impact resistance and flexibility: the pencil hardness of 2H can resist minor friction and scratches in the marine environment, the adhesion of grade 0 ensures that the coating is bonded to the substrate for a long time without falling off, the impact resistance of 50cm and the flexibility of 1mm can adapt to the mechanical stress under dynamic service scenarios such as ship navigation and marine platform vibration, and avoid coating cracking and failure.

[0072] Comparative Example 1

[0073] This comparative example uses no filler, only one type of filler, and two types of filler in combination. Figure 7The electrochemical polarization curves compare the corrosion performance of different coatings, including an uncoated metal substrate (tinplate), a coating without filler (WEMSR), a coating with only modified aluminum zinc polyphosphate (K-ZAP / WEMSR), and a coating with modified aluminum zinc polyphosphate and modified ZnS@SiO2 (K-ZAP / ZnS@K-SiO2 / WEMSR). The curves show that the coating with dual-modified filler synergistic modification exhibits the highest corrosion potential and the lowest corrosion current, demonstrating the best corrosion performance.

[0074] Comparative Example 2

[0075] In this comparative example, different types of silane coupling agents were added to component B to prepare coatings, and the hydrophobic properties of the coatings were tested. Figure 8 As shown, the highest water contact angle of 105.54° was achieved when silane coupling agent KH560 was added, demonstrating good hydrophobicity. When the silane coupling agents were KH570 and KH550, the water contact angle did not reach 90°, failing to meet the hydrophobicity requirement, and the antifouling effect was not as good as when KH560 was added.

[0076] Comparative Example 3

[0077] This comparative example included three groups of comparisons: a coating without filler, a coating with unmodified aluminum zinc polyphosphate + unmodified ZnS, and a coating with KH560-modified aluminum zinc polyphosphate + KH560-modified ZnS@SiO2. The antifouling morphology of the coatings was observed using sulfate-reducing bacteria. Figure 9 As shown in the fluorescence image: bacteria were densely attached in the control group, the amount of bacteria attached in the unmodified group was slightly reduced, and the amount of bacteria attached in the present invention group was extremely low. This confirms that the synergistic antibacterial effect of the dual-modified filler is significantly better than that of the unmodified filler and the unfilled system. Combined with the results of Comparative Example 1, this confirms the synergistic effect of the dual-modified filler of the present invention in terms of "antibacterial + corrosion resistance".

[0078] This specific embodiment is merely an explanation of the present invention and is not intended to limit the present invention. Any changes made by those skilled in the art after reading the specification of the present invention, as long as they are within the scope of the claims of the present invention, will be protected by patent law.

Claims

1. A water-based, eco-friendly, corrosion-resistant, and antifouling coating for marine environments, characterized in that: The product comprises component A and component B. Component A includes waterborne epoxy-modified silicone resin, KH560-modified aluminum zinc polyphosphate, KH560-modified ZnS@SiO2, functional additives, and deionized water. Component B is a mixture of waterborne modified amine curing agent and silane coupling agent KH560. The functional additives include anti-flash rust agent, silicone defoamer, dispersant, and substrate wetting agent.

2. The water-based eco-friendly corrosion-resistant and antifouling coating for marine environments according to claim 1, characterized in that: Component A, by mass percentage, comprises: 30-45% waterborne epoxy-modified silicone resin, 10-14% KH560-modified aluminum zinc polyphosphate, 1-3% KH560-modified ZnS@SiO2, 0.1-0.5% flash rust inhibitor, 0.1-0.5% silicone defoamer, 0.2-1% dispersant, 0.1-0.5% substrate wetting agent, and the balance being deionized water; in component B, the mass ratio of waterborne modified amine curing agent to silane coupling agent KH560 is (10-15):

1.

3. The water-based eco-friendly corrosion-resistant and antifouling coating for marine environments according to claim 2, characterized in that: In component A, the content of KH560 modified aluminum zinc polyphosphate is 12wt%, and the content of KH560 modified ZnS@SiO2 is 2wt%.

4. The water-based eco-friendly corrosion-resistant and antifouling coating for marine environments according to claim 1, characterized in that: The mass ratio of component A to component B is (1.8 to 2.2):

1.

5. The water-based eco-friendly corrosion-resistant and antifouling coating for marine environments according to claim 1, characterized in that: The flash rust inhibitor is type A01; the silicone defoamer is type 1050; the dispersant is type SN-5040 water-based dispersant; and the substrate wetting agent is type OT-75.

6. The water-based eco-friendly corrosion-resistant and antifouling coating for marine environments according to claim 1, characterized in that: The waterborne epoxy-modified silicone resin has an epoxy value of 0.06 to 0.16, a solid content of 50 ± 2%, and a viscosity of 100 to 300 mPa•s at 25°C; the waterborne modified amine curing agent has an active hydrogen equivalent of 330 and a solid content of 50 ± 1%.

7. The method for preparing the water-based eco-friendly corrosion-resistant and antifouling coating for marine environments according to any one of claims 1-6, characterized in that: Includes the following steps: S1. KH560 modified aluminum zinc polyphosphate and KH560 modified ZnS@SiO2 are mixed and added to deionized water, and ultrasonically vibrated at 30-60 kHz for 30-60 min to form a modified filler dispersion. S2. Add waterborne epoxy-modified silicone resin to a mixing tank, then add anti-flash rust agent, silicone defoamer, dispersant, and substrate wetting agent in sequence. Shear and stir at a low speed of 400-600 r / min for 15-25 min. Then add the modified filler dispersion of S1, add zirconium beads as grinding media, and grind and stir at a high speed of 2000-3000 r / min for 30-50 min. Control the particle size D90 of the system after grinding to be ≤5 μm. After filtration, obtain component A. S3. Mix the water-based modified amine curing agent and the silane coupling agent KH560 in a certain proportion, and stir at 500-800 r / min for 8-12 min to obtain component B; S4. Mix component A and component B in proportion, and shear at a low speed of 200-400 r / min for 5-10 min until the mixture is uniform. Then let it stand and mature for 15-25 min before coating.

8. The application of the waterborne eco-friendly corrosion-resistant and antifouling coating for marine environments as described in any one of claims 1-6 in the field of shipbuilding and marine engineering, characterized in that: The application method involves coating the surface of ship hulls, offshore platforms, port facilities, or seawater pipelines for antifouling and anti-corrosion purposes.

9. The application according to claim 8, characterized in that: The coating can be applied by brushing, rolling, or spraying; when spraying, the pressure is 0.3–0.5 MPa and the spraying distance is 20–30 cm; the coating thickness after curing is 50–200 μm.

10. The application according to claim 8, characterized in that: The coating process is carried out at room temperature. After completion, the coating is surface dry in 1 day and fully dry in 3 days.

Images