Preparation method and application of marine anticorrosive coating

Abstract

The application provides a preparation method and application of a marine anticorrosive coating and belongs to the technical field of marine coatings; the preparation process comprises the following steps: surface pretreatment of scale glass; adding the surface pretreated scale glass to prepare composite filler A; adding concentrated sulfuric acid to react and prepare composite filler B; adding succinic anhydride to react to prepare a polymer solution; and adding dimethyl silicone oil and stirring to mix components; the scale glass is surface treated by using a silane coupling agent first, then the surface pretreated scale glass is added into a zinc nitrate solution, uniformly dispersed, and then stirred and mixed with a 2-methyl imidazole solution to prepare the composite filler A; after the composite filler A is mixed with an epoxy resin, the anticorrosive performance of the prepared anticorrosive coating can be effectively improved, microorganisms attached to the surface of the anticorrosive coating can be killed, the adsorption of marine microorganisms can be prevented, and the non-target marine organisms have low toxicity and cannot pollute the marine environment.

Description

Technical Field

[0001] This invention relates to the field of marine coatings technology, specifically to a method for preparing and applying a marine anti-corrosion coating. Background Technology

[0002] Anti-corrosion coatings are coatings used to protect the surfaces of various materials from environmental corrosion. They can form a protective film on the surfaces of metals, wood, concrete, etc., preventing moisture, oxygen, chemicals and other corrosive media from coming into direct contact with them, thereby extending the service life of the materials. Epoxy resin is widely used as a base resin for coatings because of its good corrosion resistance and high flexibility.

[0003] However, when ordinary anti-corrosion coatings are used to protect marine service materials, such as ships, they are usually unable to prevent marine organisms from adhering to the surface of the anti-corrosion coating. As ships sail at sea for long periods of time, a large number of marine organisms will attach to the hull surface, leading to an increase in hull mass, a decrease in power performance and machine efficiency, a reduction in speed and maneuverability, and an increase in fuel consumption. These problems will eventually lead to damage to the hull coating and corrosion of the hull.

[0004] Currently, antifouling coatings are used to protect materials and prevent the adsorption of marine organisms. Traditional antifouling coatings achieve their antifouling effect by adding antibacterial agents to the coating. When the coating is immersed in seawater, it reacts and the antibacterial agent diffuses in the seawater to prevent marine organisms from attaching. However, commonly used antibacterial agents, such as cuprous oxide and organotin compounds, are highly toxic to non-target marine organisms, pollute the marine environment, exacerbate environmental degradation, increase the mortality rate of other marine organisms, and cause serious damage to the ecological environment.

[0005] Therefore, there is a need to develop a method for preparing marine anti-corrosion coatings that can prevent adsorption by marine organisms and are environmentally friendly, so as to extend the service life of marine materials. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a method for preparing marine anti-corrosion coatings and their application.

[0007] A method for preparing a marine anti-corrosion coating includes the following steps:

[0008] S1: Surface-pretreated flake glass

[0009] Add the silane coupling agent to anhydrous ethanol, stir to dissolve and mix, and prepare a mixed solution with a concentration of 2-3%. Then add HCl to the mixed solution to adjust the pH to 4-5. Then add flake glass at a solid-liquid ratio of 1g:(10-20)mL, stir for 2-3 hours, and then filter and dry to obtain surface-pretreated flake glass.

[0010] S2: Composite filler A prepared by adding surface-pretreated flake glass.

[0011] Zinc nitrate hexahydrate was dissolved in methanol, then added to the pre-treated flake glass and dispersed evenly. A methanol solution of 2-methylimidazole was then added, stirred and mixed, allowed to settle, and then centrifuged, filtered, washed and dried to obtain composite filler A.

[0012] S3: Add concentrated sulfuric acid to react and prepare composite filler B.

[0013] 2,3,5-Trimethylphenol and N-hydroxymethylacrylamide were added to anhydrous ethanol, stirred and mixed, and then concentrated sulfuric acid was added to react to obtain an intermediate for later use. Halloysite nanotubes were then pretreated in hydrochloric acid and then placed in an ethanol solution of the intermediate for loading to obtain composite filler B.

[0014] S4: Add succinic anhydride to prepare a polymer solution.

[0015] Propylene polyether was dissolved in acetone, and succinic anhydride was added to react with it. Then acrylic acid and ammonium persulfate were added to react with it to obtain a polymer solution.

[0016] S5: Add dimethyl silicone oil and stir to mix all components.

[0017] The composite filler A was ground and dispersed in a diluent, then epoxy resin and dimethyl silicone oil were added and stirred. Then, the composite filler B, the polymer solution and γ-aminopropyltriethoxysilane were added and stirred to obtain a marine anti-corrosion coating.

[0018] Furthermore, S2 specifically includes the following steps:

[0019] S2.1: Dissolve zinc nitrate hexahydrate in methanol at a solid-liquid ratio of 1g:(150~180)mL, stir and mix evenly to obtain a zinc nitrate solution;

[0020] S2.2: Add the surface-pretreated flake glass prepared in step S1 to the above zinc nitrate solution at a solid-liquid ratio of 1g:(600-700)mL, stir for 1-2 hours, and ultrasonically disperse for 10-20 minutes to obtain a dispersion;

[0021] S2.3: Dissolve 2-methylimidazole in methanol at a solid-liquid ratio of 1g:(280~320)mL, stir and mix evenly to obtain a 2-methylimidazole solution;

[0022] S2.4: Add equal volumes of the above dispersion and 2-methylimidazole solution to a mixer, stir at a rate of 200-300 r / min for 1-2 h, and then let stand for 6-8 h to obtain a sediment.

[0023] S2.5: Centrifuge the above sediment at a rate of 5000-6000 r / min for 3-5 min, filter, wash with methanol 2-4 times, and dry in an oven at 70-80℃ to constant weight to obtain composite packing A.

[0024] Furthermore, S3 specifically includes the following steps:

[0025] S3.1: Add 2,3,5-trimethylphenol and N-hydroxymethylacrylamide to anhydrous ethanol at a solid-liquid ratio of (13-15)g:(24-25)g:(90-100)mL, stir for 1-2 hours, mix evenly, and obtain a mixed solution;

[0026] S3.2: Add concentrated sulfuric acid at a constant rate of 10% of the volume of the above mixed solution, stir for 20-30 min, heat at 35-40℃ for 2-3 h, filter and wash until neutral, and then recrystallize with anhydrous ethanol to obtain the intermediate.

[0027] S3.3: Add halloysite nanotubes to hydrochloric acid at a solid-liquid ratio of 1g:(16-18)mL, heat to 70-80℃ and stir for 4-5h, then centrifuge, filter, wash, dry and grind to obtain pretreated nanotubes;

[0028] 3.4: Dissolve the above intermediate in anhydrous ethanol to prepare an intermediate solution with a mass fraction of 20-30%. Then mix the above pretreated nanotubes and intermediate solution at a solid-liquid ratio of 1g:(40-50)mL and sonicate for 20-30min to obtain a suspension.

[0029] S3.5: Place the above suspension in a vacuum dryer, use a vacuum pump to evacuate to -0.2 to -0.1 MPa, maintain for 30 to 40 minutes, then restore to normal pressure. Repeat 2 to 3 times to obtain the loaded suspension.

[0030] S3.6: Centrifuge the above-mentioned loaded suspension at a rate of 4000-5000 r / min for 5-6 min, remove the filtrate, wash with ethanol 2-3 times, vacuum dry to constant weight, and grind into powder to obtain composite filler B.

[0031] Furthermore, S4 specifically includes the following steps:

[0032] S4.1: Dissolve propylene polyether in acetone, add succinic anhydride, heat to 60-70°C, stir and react for 1-2 hours, then remove acetone by vacuum distillation to obtain the precursor.

[0033] S4.2: Add the above precursor to deionized water at a solid-liquid ratio of 1g:(2-4)mL, and heat and stir at 60-70℃ under a nitrogen atmosphere to obtain a precursor solution.

[0034] S4.3: Add acrylic acid and ammonium persulfate to the above precursor solution, heat to 75-85°C, and stir for 2-3 hours to obtain a polymer solution.

[0035] Furthermore, S5 specifically includes the following steps:

[0036] S5.1: Grind the composite filler A obtained in step S2.5, add it to the diluent, and ultrasonically disperse it for 5-10 minutes to obtain solution A;

[0037] S5.2: Add epoxy resin and dimethyl silicone oil to the above solution A, and stir at a rate of 200-300 r / min for 1-2 h to obtain solution B;

[0038] S5.3: Add the composite filler B obtained in step S3.6, the polymer solution obtained in step S4.3, and γ-aminopropyltriethoxysilane to the above solution B, and adjust the stirring speed to 800-1000 r / min, and stir for 1-2 h to obtain a marine anti-corrosion coating.

[0039] Furthermore, the volume ratio of propylene polyether to acetone is 1:(10-20), and the molar ratio of propylene polyether to succinic anhydride is 1:(1.1-1.3).

[0040] Furthermore, the molar ratio of acrylic acid to the precursor is (8-10):1, and the solid-liquid ratio of ammonium persulfate to the precursor solution is 1g:(10-12)mL.

[0041] Further, by weight, the marine anti-corrosion coating comprises: 80-90 parts epoxy resin, 16-20 parts composite filler A, 10-12 parts composite filler B, 6-10 parts dimethyl silicone oil, 6-8 parts polymer solution, 3-5 parts diluent and 2-3 parts γ-aminopropyltriethoxysilane.

[0042] Furthermore, the diluent is prepared by mixing xylene and n-butanol in a mass ratio of (2-3):1.

[0043] Application of a marine anti-corrosion coating: The marine anti-corrosion coating prepared according to the above-mentioned preparation method is sprayed onto the surface of marine service metal materials. After drying and curing, the metal materials can be protected.

[0044] Compared with the prior art, the present invention has at least the following beneficial effects:

[0045] 1. This invention prepares composite filler A by first surface-treating flake glass with a silane coupling agent, then adding the pre-treated flake glass to a zinc nitrate solution, dispersing it evenly, and then mixing it with a 2-methylimidazole solution. On the one hand, flake glass has excellent corrosion resistance; on the other hand, the imidazole in composite filler A can interact with the epoxy resin matrix, increasing the crosslinking density of the epoxy resin. Therefore, mixing composite filler A with epoxy resin can effectively improve the corrosion resistance of the prepared anti-corrosion coating. In addition, the zinc ions in composite filler A can be released from the crystals and generate electrostatic interactions with the cell walls, thereby killing microorganisms attached to the surface of the anti-corrosion coating, preventing the adsorption of marine microorganisms, achieving an antifouling effect, and having low toxicity to non-target marine organisms, thus not polluting the marine environment.

[0046] 2. The intermediate prepared by dissolving 2,3,5-trimethylphenol and N-hydroxymethylacrylamide in anhydrous ethanol and then adding concentrated sulfuric acid to react has the characteristics of low toxicity and lipid solubility. It can penetrate the cell membrane of organisms and enter the cell interior, disrupting the lipid bilayer structure of the membrane, leading to increased membrane permeability, loss of intracellular ion concentration and nutrients, thereby inhibiting the growth of bacteria and algae. The intermediate is dissolved in anhydrous ethanol and then mixed with pretreated halloysite nanotubes to prepare composite filler B, thereby encapsulating the intermediate in halloysite nanotubes, which can better control the release rate and provide effective and long-lasting antibacterial and antialgae effects. Adding composite filler B to anticorrosive coatings can effectively improve the antibacterial and antialgae effects of the anticorrosive coatings, thereby improving their antifouling performance.

[0047] 3. This invention prepares a precursor by first reacting propylene polyether with succinic anhydride in acetone, then dispersing the precursor in deionized water and polymerizing it with acrylic acid to form a polymer solution. Adding this polymer solution to the anti-corrosion coating increases the bonding sites between the anti-corrosion coating and the substrate, thereby improving the adhesion of the anti-corrosion coating to the substrate. Furthermore, it can effectively isolate the substrate from the corrosive medium, playing a physical shielding role, thereby further improving the anti-corrosion performance of the coating. Attached Figure Description

[0048] The accompanying drawings, which are incorporated herein and form part of the specification, illustrate embodiments of the present disclosure and, together with the specification, further serve to explain the principles of the present disclosure and enable those skilled in the art to implement and use the present disclosure.

[0049] Figure 1 This is a flowchart illustrating the preparation method of the marine anti-corrosion coating used in the embodiments of the present invention. Detailed Implementation

[0050] The preparation method and application of a marine anti-corrosion coating provided by the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. It should also be noted that, to make the embodiments more detailed, the following embodiments are the best and preferred embodiments, and those skilled in the art can use other alternative methods to implement some well-known technologies; moreover, the accompanying drawings are only for more specific description of the embodiments and are not intended to specifically limit the present invention.

[0051] Example 1

[0052] A method for preparing a marine anti-corrosion coating, such as Figure 1 As shown, it includes the following steps:

[0053] S1: Surface-pretreated flake glass

[0054] The silane coupling agent was added to anhydrous ethanol, stirred and dissolved to prepare a 2% mixed solution. Then, HCl was added to the mixed solution to adjust the pH to 4. Then, flake glass was added at a solid-liquid ratio of 1g:10mL. After stirring for 2 hours, the flake glass was obtained by filtration and drying.

[0055] S2: Composite filler A prepared by adding surface-pretreated flake glass.

[0056] Zinc nitrate hexahydrate was dissolved in methanol at a solid-liquid ratio of 1g:150mL and stirred until homogeneous to obtain a zinc nitrate solution. Then, the surface-pretreated flake glass prepared in step S1 was added to the zinc nitrate solution at a solid-liquid ratio of 1g:600mL, stirred for 1 hour, and ultrasonically dispersed for 10 minutes to obtain a dispersion. 2-Methylimidazole was then dissolved in methanol at a solid-liquid ratio of 1g:280mL and stirred until homogeneous to obtain a 2-methylimidazole solution. Subsequently, equal volumes of the dispersion and the 2-methylimidazole solution were added to a mixer and stirred at a rate of 200r / min for 1 hour. After standing for 6 hours, a sediment was obtained. Finally, the sediment was centrifuged at a rate of 5000r / min for 3 minutes, filtered, washed twice with methanol, and dried in a 70℃ oven to constant weight to obtain composite filler A.

[0057] S3: Add concentrated sulfuric acid to react and prepare composite filler B.

[0058] 2,3,5-Trimethylphenol and N-hydroxymethylacrylamide were added to anhydrous ethanol at a solid-liquid ratio of 13g:24g:90mL and stirred for 1 hour to obtain a homogeneous solution. Concentrated sulfuric acid (10% by volume of the solution) was then added to the solution at a uniform rate, and the mixture was stirred for 20 minutes. The solution was then heated at 35°C for 2 hours. After filtration and washing until neutral, the solution was recrystallized from anhydrous ethanol to obtain an intermediate for later use. Halloysite nanotubes were then added to hydrochloric acid at a solid-liquid ratio of 1g:16mL, heated to 70°C, and stirred for 4 hours. After centrifugation, filtration, washing, drying, and grinding, pretreated nanotubes were obtained. The pretreated nanotubes were prepared for use. Subsequently, the intermediate was dissolved in anhydrous ethanol to prepare an intermediate solution with a mass fraction of 20%. The pretreated nanotubes and the intermediate solution were mixed at a solid-liquid ratio of 1g:40mL and ultrasonically treated for 20min to obtain a suspension. The suspension was then placed in a vacuum dryer and evacuated to -0.2MPa using a vacuum pump. After maintaining the vacuum for 30min, the pressure was restored to normal. This process was repeated twice to obtain a loaded suspension. Finally, the loaded suspension was centrifuged at 4000r / min for 5min. After removing the filtrate, the nanotubes were washed twice with ethanol, vacuum dried to constant weight, and ground into powder to obtain composite filler B.

[0059] S4: Add succinic anhydride to prepare a polymer solution.

[0060] Acrylic polyether was dissolved in acetone, and succinic anhydride was added. The mixture was heated to 60°C and stirred for 1 hour. The acetone was then removed by vacuum distillation to obtain the precursor. The volume ratio of acrylic polyether to acetone was 1:10, and the molar ratio of acrylic polyether to succinic anhydride was 1:1.1. The precursor was then added to deionized water at a solid-liquid ratio of 1 g:2 mL. The mixture was heated and stirred to 60°C under a nitrogen atmosphere to obtain the precursor solution. Acrylic acid and ammonium persulfate were then added to the precursor solution, and the mixture was heated to 75°C and stirred for 2 hours to obtain the polymer solution. The molar ratio of acrylic acid to the precursor was 8:1, and the solid-liquid ratio of ammonium persulfate to the precursor solution was 1 g:10 mL.

[0061] S5: Add dimethyl silicone oil and stir to mix all components.

[0062] By weight, 16 parts of the composite filler A obtained in step S2 were ground, and then 3 parts of a diluent prepared by mixing xylene and n-butanol in a mass ratio of 2:1 were added. The mixture was ultrasonically dispersed for 5 minutes to obtain liquid A. Then, 80 parts of epoxy resin and 6 parts of dimethyl silicone oil were added to liquid A, and the mixture was stirred at a rate of 200 r / min for 1 hour to obtain liquid B. Subsequently, 10 parts of the composite filler B obtained in step S3, 6 parts of the polymer solution obtained in step S4, and 2 parts of γ-aminopropyltriethoxysilane were added to liquid B, and the stirring rate was adjusted to 800 r / min. The mixture was stirred for 1 hour to obtain a marine anti-corrosion coating.

[0063] The performance test results are shown in Table 1 below:

[0064] The above-mentioned marine anti-corrosion coating is evenly sprayed onto the steel plate and then placed in a ventilated place to air dry naturally to obtain a sample.

[0065] First, the sample was subjected to a neutral salt spray test (NSS) according to ISO 7253-1996. The test chamber temperature was (35±2)℃, and the solution was 5% NaCl solution with a pH close to neutral (6.5~7.2).

[0066] Secondly, referring to GB / T5370—2007 "Test Method for Shallow Sea Immersion of Antifouling Paint Samples", the samples were immersed on floating rafts in Qingdao Bay, China, to a depth of 1m, with the sample surface parallel to the main current of the sea. The samples were observed regularly, and the antifouling performance of the coating was evaluated based on the species and quantity of organisms attached to the samples.

[0067] Finally, referring to GB / T5210—2006, the adhesion of the composite coating was measured using an adhesion tester, with the stretching rate set to 0.2 MPa / s.

[0068] Example 2

[0069] A method for preparing a marine anti-corrosion coating, such as Figure 1 As shown, it includes the following steps:

[0070] S1: Surface-pretreated flake glass

[0071] The silane coupling agent was added to anhydrous ethanol, stirred and dissolved to prepare a 2.5% mixed solution. HCl was then added to the mixed solution to adjust the pH to 4.5. The solution was then added to flake glass at a solid-liquid ratio of 1g:15mL. After stirring for 2.5h, the solution was filtered and dried to obtain surface-pretreated flake glass.

[0072] S2: Composite filler A prepared by adding surface-pretreated flake glass.

[0073] Zinc nitrate hexahydrate was dissolved in methanol at a solid-liquid ratio of 1g:165mL and stirred until homogeneous to obtain a zinc nitrate solution. Then, the surface-pretreated flake glass prepared in step S1 was added to the zinc nitrate solution at a solid-liquid ratio of 1g:650mL, stirred for 1.5h, and ultrasonically dispersed for 15min to obtain a dispersion for later use. Then, 2-methylimidazole was dissolved in methanol at a solid-liquid ratio of 1g:300mL and stirred until homogeneous to obtain a 2-methylimidazole solution. Subsequently, equal volumes of the dispersion and the 2-methylimidazole solution were added to a mixer and stirred at a rate of 250r / min for 1.5h, and then allowed to stand for 7h to obtain a sediment. Finally, the sediment was centrifuged at a rate of 5500r / min for 4min, filtered, washed three times with methanol, and dried in a 75℃ oven to constant weight to obtain composite filler A.

[0074] S3: Add concentrated sulfuric acid to react and prepare composite filler B.

[0075] 2,3,5-Trimethylphenol and N-hydroxymethylacrylamide were added to anhydrous ethanol at a solid-liquid ratio of 14g:24.5g:95mL and stirred for 1.5h to obtain a homogeneous solution. Then, concentrated sulfuric acid (10% by volume of the solution) was added to the solution at a uniform rate, and the mixture was stirred for 25min. The solution was then heated at 37.5℃ for 2.5h. After filtration and washing until neutral, the solution was recrystallized from anhydrous ethanol to obtain an intermediate for later use. Halloysite nanotubes were then added to hydrochloric acid at a solid-liquid ratio of 1g:17mL, heated to 75℃ and stirred for 4.5h. After centrifugation, filtration, washing, drying, and grinding, a pre-… Nanotubes were processed and set aside. Subsequently, the intermediate was dissolved in anhydrous ethanol to prepare an intermediate solution with a mass fraction of 25%. The pretreated nanotubes and the intermediate solution were mixed at a solid-liquid ratio of 1g:45mL and ultrasonically treated for 25min to obtain a suspension. The suspension was then placed in a vacuum dryer and evacuated to -0.15MPa using a vacuum pump. After maintaining the vacuum for 35min, the pressure was restored to normal. This process was repeated twice to obtain a loaded suspension. Finally, the loaded suspension was centrifuged at 4500r / min for 5.5min. After removing the filtrate, the suspension was washed twice with ethanol, vacuum dried to constant weight, and ground into powder to obtain composite filler B.

[0076] S4: Add succinic anhydride to prepare a polymer solution.

[0077] Acrylic polyether was dissolved in acetone, and succinic anhydride was added. The mixture was heated to 65°C and stirred for 1.5 h. The acetone was then removed by vacuum distillation to obtain the precursor. The volume ratio of acrylic polyether to acetone was 1:15, and the molar ratio of acrylic polyether to succinic anhydride was 1:1.2. The precursor was then added to deionized water at a solid-liquid ratio of 1 g:3 mL. The mixture was heated and stirred to 65°C under a nitrogen atmosphere to obtain the precursor solution. Acrylic acid and ammonium persulfate were then added to the precursor solution, and the mixture was heated to 80°C and stirred for 2.5 h to obtain the polymer solution. The molar ratio of acrylic acid to the precursor was 9:1, and the solid-liquid ratio of ammonium persulfate to the precursor solution was 1 g:11 mL.

[0078] S5: Add dimethyl silicone oil and stir to mix all components.

[0079] By weight, 18 parts of the composite filler A obtained in step S2 were ground, and then 4 parts of a diluent prepared by mixing xylene and n-butanol in a mass ratio of 2.5:1 were added. The mixture was ultrasonically dispersed for 7.5 min to obtain solution A. Then, 85 parts of epoxy resin and 8 parts of dimethyl silicone oil were added to solution A, and the mixture was stirred at a rate of 250 r / min for 1.5 h to obtain solution B. Subsequently, 11 parts of the composite filler B obtained in step S3, 7 parts of the polymer solution obtained in step S4, and 2.5 parts of γ-aminopropyltriethoxysilane were added to solution B, and the stirring rate was adjusted to 900 r / min. The mixture was stirred for 1.5 h to obtain the marine anti-corrosion coating.

[0080] Then, the performance test was performed according to the performance test method in Example 1, and the results are shown in Table 1 below.

[0081] Example 3

[0082] A method for preparing a marine anti-corrosion coating, such as Figure 1 As shown, it includes the following steps:

[0083] S1: Surface-pretreated flake glass

[0084] The silane coupling agent was added to anhydrous ethanol, stirred and dissolved to prepare a 3% mixed solution. HCl was then added to the mixed solution to adjust the pH to 5. Flake glass was then added at a solid-liquid ratio of 1g:20mL. After stirring for 3 hours, the solution was filtered and dried to obtain surface-pretreated flake glass.

[0085] S2: Composite filler A prepared by adding surface-pretreated flake glass.

[0086] Zinc nitrate hexahydrate was dissolved in methanol at a solid-liquid ratio of 1g:180mL and stirred until homogeneous to obtain a zinc nitrate solution. Then, the surface-pretreated flake glass prepared in step S1 was added to the zinc nitrate solution at a solid-liquid ratio of 1g:700mL. The mixture was stirred for 2 hours and ultrasonically dispersed for 20 minutes to obtain a dispersion. Next, 2-methylimidazole was dissolved in methanol at a solid-liquid ratio of 1g:320mL and stirred until homogeneous to obtain a 2-methylimidazole solution. Equal volumes of the dispersion and the 2-methylimidazole solution were then added to a mixer and stirred at 300 rpm for 2 hours. The mixture was then allowed to stand for 8 hours to obtain a sediment. Finally, the sediment was centrifuged at 6000 rpm for 5 minutes, filtered, washed four times with methanol, and dried in an 80℃ oven to constant weight to obtain composite filler A.

[0087] S3: Add concentrated sulfuric acid to react and prepare composite filler B.

[0088] 2,3,5-Trimethylphenol and N-hydroxymethylacrylamide were added to anhydrous ethanol at a solid-liquid ratio of 15g:25g:100mL and stirred for 2 hours to obtain a homogeneous solution. Concentrated sulfuric acid (10% by volume of the solution) was then added to the solution at a uniform rate, and the mixture was stirred for 30 minutes. The solution was then heated at 40℃ for 3 hours. After filtration and washing until neutral, the solution was recrystallized from anhydrous ethanol to obtain an intermediate for later use. Halloysite nanotubes were then added to hydrochloric acid at a solid-liquid ratio of 1g:18mL, heated to 80℃, and stirred for 5 hours. After centrifugation, filtration, washing, drying, and grinding, pretreated nanotubes were obtained. The pretreated nanotubes were prepared for use. Then, the intermediate was dissolved in anhydrous ethanol to prepare a 30% (w / w) intermediate solution. The pretreated nanotubes and the intermediate solution were mixed at a solid-liquid ratio of 1 g: 50 mL and ultrasonically treated for 30 min to obtain a suspension. The suspension was then placed in a vacuum dryer and evacuated to -0.1 MPa using a vacuum pump. After maintaining this pressure for 40 min, the pressure was restored to normal. This process was repeated three times to obtain a loaded suspension. Finally, the loaded suspension was centrifuged at 5000 r / min for 6 min. After removing the filtrate, the suspension was washed three times with ethanol, vacuum dried to constant weight, and ground into powder to obtain composite filler B.

[0089] S4: Add succinic anhydride to prepare a polymer solution.

[0090] Acrylic polyether was dissolved in acetone, then succinic anhydride was added, and the mixture was heated to 70°C and stirred for 2 hours. The acetone was then removed by vacuum distillation to obtain the precursor. The volume ratio of acrylic polyether to acetone was 1:20, and the molar ratio of acrylic polyether to succinic anhydride was 1:1.3. The precursor was then added to deionized water at a solid-liquid ratio of 1 g:4 mL. The mixture was heated and stirred to 70°C under a nitrogen atmosphere to obtain the precursor solution. Acrylic acid and ammonium persulfate were then added to the precursor solution, and the mixture was heated to 85°C and stirred for 3 hours to obtain the polymer solution. The molar ratio of acrylic acid to the precursor was 10:1, and the solid-liquid ratio of ammonium persulfate to the precursor solution was 1 g:12 mL.

[0091] S5: Add dimethyl silicone oil and stir to mix all components.

[0092] By weight, 20 parts of the composite filler A obtained in step S2 were ground, and then 5 parts of a diluent prepared by mixing xylene and n-butanol in a mass ratio of 3:1 were added. The mixture was ultrasonically dispersed for 10 minutes to obtain liquid A. Then, 90 parts of epoxy resin and 10 parts of dimethyl silicone oil were added to liquid A and stirred at a rate of 300 r / min for 2 hours to obtain liquid B. Subsequently, 12 parts of the composite filler B obtained in step S3, 8 parts of the polymer solution obtained in step S4, and 3 parts of γ-aminopropyltriethoxysilane were added to liquid B, and the stirring rate was adjusted to 1000 r / min and stirred for 2 hours to obtain a marine anti-corrosion coating.

[0093] Then, the performance test was performed according to the performance test method in Example 1, and the results are shown in Table 1 below.

[0094] Table 1: Summary of Performance Test Results for Examples 1-3

[0095] Test Project Salt spray corrosion 1200h Offshore hanging board 1 month 3 months of offshore hanging board Adhesion (MPa) Example 1 Uncorroded No adhesion A small amount of biological attachment 4.86 Example 2 Uncorroded No adhesion A small amount of biological attachment 4.92 Example 3 Uncorroded No adhesion A small amount of biological attachment 4.93

[0096] Comparative Example 1

[0097] The difference between this comparative example and Example 1 is that steps S1-2 are removed, and composite filler A in step S5 is removed. Then, the performance of the prepared anti-corrosion coating is tested according to the performance test method in Example 1, and the results are shown in Table 2 below.

[0098] Table 2: Summary of Performance Test Results for Comparative Example 1 and Example 1

[0099] Test Project Salt spray corrosion 1200h Offshore hanging board 1 month 3 months of offshore hanging board Example 1 Uncorroded No adhesion A small amount of biological attachment Comparative Example 1 Pitting occurred A small amount of biological attachment A small amount of biological attachment

[0100] As shown in Table 1 above, the anti-corrosion coating in Comparative Example 1 exhibited pitting corrosion after 1200 hours of salt spray corrosion, and a small amount of biofouling appeared after one month of sea-based application. This indicates that by first surface-treating the flake glass with a silane coupling agent, then adding the pre-treated flake glass to a zinc nitrate solution, dispersing it evenly, and then mixing it with a 2-methylimidazole solution to prepare composite filler A, the excellent corrosion resistance of the flake glass and the interaction between the imidazole in composite filler A and the epoxy resin matrix, which increases the crosslinking density of the epoxy resin, the mixture of composite filler A and epoxy resin can effectively improve the anti-corrosion performance of the prepared anti-corrosion coating. Furthermore, the zinc ions in composite filler A can be released from the crystals and generate electrostatic interactions with the cell walls, thereby killing microorganisms attached to the surface of the anti-corrosion coating and preventing the adsorption of marine microorganisms, thus achieving an antifouling effect. Moreover, it has low toxicity to non-target marine organisms and will not pollute the marine environment.

[0101] Comparative Example 2

[0102] The difference between this comparative example and Example 1 is that the composite filler B in step S5 is replaced with an equal amount of the intermediate obtained in step S3. Then, the performance of the prepared anti-corrosion coating is tested according to the performance test method in Example 1, and the results are shown in Table 3 below.

[0103] Comparative Example 3

[0104] The difference between this comparative example and Example 1 is that step S3 is removed, and the composite filler B in step S5 is removed. Then, the performance of the prepared anti-corrosion coating is tested according to the performance test method in Example 1, and the results are shown in Table 3 below.

[0105] Table 3: Summary of Performance Test Results for Comparative Examples 2-3 and Example 1

[0106] Test Project Offshore hanging board 1 month 3 months of offshore hanging board Example 1 No adhesion A small amount of biological attachment Comparative Example 2 No adhesion The surface is covered with marine organisms such as barnacles and seaweed. Comparative Example 3 Barnacles and seaweed attached to the surface The surface is covered with a large number of harmless organisms such as algae and animal larvae.

[0107] As shown in Table 3 above, although adding the intermediate directly to the anti-fouling coating in Comparative Example 2 can achieve a short-term antifouling effect within one month of the sea-mounted plating, barnacles and algae adhere to the sample surface after three months, indicating poor antifouling durability. Therefore, the intermediate prepared by dissolving 2,3,5-trimethylphenol and N-hydroxymethylacrylamide in anhydrous ethanol and then adding concentrated sulfuric acid has low toxicity and lipid solubility. It can penetrate the cell membrane of organisms, disrupting the lipid bilayer structure of the membrane, increasing membrane permeability, and causing the loss of intracellular ion concentration and nutrients, thereby inhibiting the growth of bacteria and algae. Dissolving this intermediate in anhydrous ethanol and mixing it with pretreated halloysite nanotubes to prepare composite filler B, encapsulating the intermediate within halloysite nanotubes, allows for better control of the release rate, providing an effective and long-lasting antibacterial and antialgal effect. Adding this composite filler B to the anti-fouling coating can effectively improve the antibacterial and antialgal effect of the coating, thereby improving its antifouling performance.

[0108] Comparative Example 4

[0109] The difference between this comparative example and Example 1 is that step S4 is removed and the polymer solution in step S5 is removed. Then, the performance of the prepared anti-corrosion coating is tested according to the performance test method in Example 1, and the results are shown in Table 4 below.

[0110] Table 4: Summary of Performance Test Results for Comparative Example 4 and Example 1

[0111] Test Project Salt spray corrosion 1200h Adhesion (MPa) Example 1 Uncorroded 4.86 Comparative Example 4 Pitting occurred 3.23

[0112] As can be seen from Table 4 above, the sample in Comparative Example 4 showed pitting corrosion on its surface after 1200 hours of salt spray corrosion, and the adhesion was 3.23 MPa, both of which were less than the test results in Example 1. This indicates that by first reacting propylene polyether with succinic anhydride in acetone to prepare a precursor, then dispersing the precursor in deionized water, and polymerizing it with acrylic acid to prepare a polymer solution, adding this polymer solution to the anti-corrosion coating can increase the bonding sites between the anti-corrosion coating and the substrate, thereby improving the adhesion of the anti-corrosion coating to the substrate. Furthermore, it can effectively isolate the substrate from the corrosive medium, playing a physical shielding role, thereby further improving the anti-corrosion performance of the coating.

[0113] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A method for preparing a marine anticorrosive coating, characterized by, The method comprises the following steps: S1: surface pretreatment of flaky glass The silane coupling agent is added into anhydrous ethanol, stirred and dissolved, mixed to prepare a mixed solution with a concentration of 2-3%, then HCl is added to adjust the pH to 4-5, then flaky glass is added at a solid-liquid ratio of 1g:(10-20)mL, stirred for 2-3h, then filtered and dried to obtain the surface pretreated flaky glass; S2: preparation of composite filler A by adding the surface pretreated flaky glass The zinc nitrate hexahydrate is dissolved in methanol, then the above surface pretreated flaky glass is added and uniformly dispersed, then the 2-methyl imidazole methanol solution is added, stirred and mixed, and then settled, centrifuged, filtered, washed and dried to obtain the composite filler A; S3: reaction by adding concentrated sulfuric acid and preparation of composite filler B The 2,3,5-trimethyl phenol and N-hydroxymethyl acrylamide are added into anhydrous ethanol, stirred and mixed, then concentrated sulfuric acid is added for reaction to obtain an intermediate, which is used for standby, then the halloysite nanotube is pretreated in hydrochloric acid, and then loaded in the ethanol solution of the intermediate to obtain the composite filler B; S4: preparation of polymer solution by adding succinic anhydride for reaction The propenyl polyether is dissolved in acetone, then succinic anhydride is added for reaction, then acrylic acid and ammonium persulfate are added for reaction to obtain the polymer solution; S5: stirring and mixing of components by adding dimethyl silicone oil The above composite filler A is ground and dispersed in a diluent, then the epoxy resin and dimethyl silicone oil are added, stirred and mixed, then the above composite filler B, the above polymer solution and γ-aminopropyl triethoxysilane are added, and the stirring and mixing are continued to obtain the marine anticorrosive coating.

2. The method of claim 1, wherein the marine anticorrosive coating is prepared by mixing the anticorrosive pigment, the binder, the solvent, and the additive. S2 comprises the following steps: S2.1: zinc nitrate solution is prepared by dissolving zinc nitrate hexahydrate in methanol at a solid-liquid ratio of 1g:(150-180)mL, and stirring and mixing uniformly; S2.2: the surface pretreated flaky glass prepared in step S1 is added into the above zinc nitrate solution at a solid-liquid ratio of 1g:(600-700)mL, stirred for 1-2h, and ultrasonically dispersed for 10-20min to obtain a dispersion liquid; S2.3: 2-methyl imidazole solution is prepared by dissolving 2-methyl imidazole in methanol at a solid-liquid ratio of 1g:(280-320)mL, and stirring and mixing uniformly; S2.4: equal volumes of the above dispersion liquid and 2-methyl imidazole solution are added into a stirrer, stirred at a speed of 200-300r / min for 1-2h, and then settled for 6-8h to obtain a settled liquid; S2.5: the above settled liquid is centrifuged at a speed of 5000-6000r / min for 3-5min, filtered, washed with methanol for 2-4 times, and dried in an oven at 70-80℃ to constant weight to obtain the composite filler A.

3. The method for preparing a marine anti-corrosion coating according to claim 2, characterized in that, S3 comprises the following steps: S3.1: the mixed solution is prepared by adding 2,3,5-trimethyl phenol and N-hydroxymethyl acrylamide into anhydrous ethanol at a solid-liquid ratio of (13-15)g:(24-25)g:(90-100)mL, stirring for 1-2h, and uniformly mixing; S3.2: The concentrated sulfuric acid is added into the mixed solution at a rate of 10% of the volume of the mixed solution, and stirred for 20-30 min, then heated at 35-40℃ for 2-3 h. After filtration, washing to neutral, and recrystallization with anhydrous ethanol, the intermediate is obtained; S3.3: The halloysite nanotubes are added into hydrochloric acid at a solid-liquid ratio of 1g:(16-18)mL, heated to 70-80℃ and stirred for 4-5 h. After centrifugal filtration, washing, drying and grinding, the pretreated nanotubes are obtained; 3.4: The intermediate is dissolved in anhydrous ethanol to prepare a 20-30% intermediate solution by mass fraction. The pretreated nanotubes and the intermediate solution are mixed at a solid-liquid ratio of 1g:(40-50)mL, and ultrasonic treatment is performed for 20-30 min to obtain a suspension; S3.5: The suspension is placed in a vacuum dryer, and vacuum is applied by a vacuum pump to-0.2 to-0.1 MPa, maintained for 30-40 min, then returned to normal pressure, and the process is repeated 2-3 times to obtain a loaded suspension; S3.6: The loaded suspension is centrifuged at a speed of 4000-5000 r / min for 5-6 min, the filtrate is removed, washed with ethanol for 2-3 times, vacuum dried to constant weight, and ground into powder to obtain the composite filler B.

4. The method of claim 3, wherein the marine anticorrosive coating is prepared by adding the above-mentioned components in the order of the above-mentioned order, and stirring the mixture at 60°C for 1 hour. S4 includes the following steps: S4.1: The propylene-based polyether is dissolved in acetone, then succinic anhydride is added, and heated to 60-70℃, stirred for 1-2 h, then acetone is removed by distillation under reduced pressure to obtain a precursor; S4.2: The precursor is added into deionized water at a solid-liquid ratio of 1g:(2-4)mL, heated and stirred to 60-70℃ under nitrogen atmosphere to obtain a precursor solution; S4.3: Acrylic acid and ammonium persulfate are added into the precursor solution, heated to 75-85℃, and stirred for 2-3 h to obtain a polymer solution.

5. The method for preparing a marine anti-corrosion coating according to claim 4, characterized in that, S5 includes the following steps: S5.1: The composite filler A prepared in step S2.5 is ground, then added into a diluent, and ultrasonic dispersed for 5-10 min to obtain A liquid; S5.2: Epoxy resin and dimethyl silicone oil are added into the A liquid, and stirred at a speed of 200-300 r / min for 1-2 h to obtain B liquid; S5.3: The composite filler B prepared in step S3.6, the polymer solution prepared in step S4.3, and γ-aminopropyl triethoxysilane are added into the B liquid, and the stirring speed is adjusted to 800-1000 r / min, and stirred for 1-2 h to obtain the marine anticorrosive coating.

6. The method for preparing a marine anti-corrosion coating according to claim 4, characterized in that, The volume ratio of propylene-based polyether to acetone is 1:(10-20), and the molar ratio of propylene-based polyether to succinic anhydride is 1:(1.1-1.3).

7. The method for preparing a marine anti-corrosion coating according to claim 4, characterized in that, The molar ratio of acrylic acid to precursor is (8-10):1, and the solid-liquid ratio of ammonium persulfate to precursor solution is 1g:(10-12)mL.

8. The method for preparing a marine anti-corrosion coating according to claim 5, characterized in that, The marine anticorrosive coating includes, by weight parts: 80-90 parts of epoxy resin, 16-20 parts of composite filler A, 10-12 parts of composite filler B, 6-10 parts of dimethyl silicone oil, 6-8 parts of polymer solution, 3-5 parts of diluent, and 2-3 parts of γ-aminopropyl triethoxysilane.

9. The method for preparing a marine anti-corrosion coating according to claim 5, characterized in that, The diluent is prepared by mixing xylene and n-butanol in a mass ratio of (2-3):

1.

10. Use of a marine anticorrosive coating, characterized in that The marine anticorrosive coating prepared by the preparation method of the marine anticorrosive coating according to any one of claims 1-9 is sprayed on the surface of a marine service metal material, and after drying and curing, the metal material can be protected.

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