Marine facility corrosion protection layer regulation method suitable for strong salt spray environment

Abstract

The embodiment of the present application relates to the technical field of heavy-duty coating, and discloses a marine facility corrosion protection layer regulation and control method suitable for strong salt spray environment, which comprises preparing a self-activated intermediate paint and applying it between a primer and a topcoat to form a composite protective layer; the core is that a double-triggered mineralization precursor is contained in the main agent of the self-activated intermediate paint, the precursor is composed of BF4 ‑ loaded hydrophobic modified zeolite and zinc phosphate coated water glass microparticles; when the coating is damaged, the corrosion microenvironment of the damaged area can synergistically trigger the zeolite to release BF4 ‑ to buffer the pH, at the same time trigger the dissolution of the coated water glass microparticles and release silicate ions; the released silicate ions react in situ with cations in the environment to generate mineralization products, plugging the damaged area. The present application can actively inhibit corrosion propagation and cathodic delamination after coating damage, significantly improving the long-term reliability and service life of the protective layer.

Description

Technical Field

[0001] This invention relates to the field of heavy-duty anti-corrosion coating technology, specifically to a method for regulating the anti-corrosion protective layer of marine facilities adapted to strong salt spray environments. Background Technology

[0002] Offshore wind power, as an important clean energy source, relies on key supporting structures such as jackets, which operate for extended periods in harsh marine environments characterized by high salinity, high humidity, strong ultraviolet radiation, and wave erosion. Their steel substrates face extremely serious corrosion threats. Currently, long-lasting heavy-duty anti-corrosion coating systems are the primary technical means to ensure the safety and durability of these critical infrastructures.

[0003] Current anti-corrosion coating technology mainly relies on the physical shielding effect of the coating itself, forming a dense, low-permeability isolation film to isolate the metal substrate from external corrosive media (such as water, oxygen, chloride ions, etc.). However, during the manufacturing, transportation, installation, and long-term service of equipment, the coating will inevitably suffer mechanical damage such as scratches and cracks due to factors such as collisions and abrasions.

[0004] Once a through-thickness defect develops in the coating, this passive physical protective barrier fails. Exposed metal substrates rapidly form corrosion microcells in a salt spray environment, leading not only to rapid electrochemical corrosion at the defect site but, more seriously, to corrosion spreading along the coating-substrate interface. Simultaneously, in the cathodic region at the defect edge, oxygen reduction reactions generate and enrich large amounts of hydroxide ions, creating a locally highly alkaline microenvironment. This high-pH environment disrupts the chemical bonds or physical adhesion between the coating resin and the substrate, triggering severe cathodic disbondment, resulting in large-area coating detachment and ultimately causing the entire protective system to fail. Therefore, traditional anti-corrosion coatings lack proactive response and self-repair capabilities when facing mechanical damage, failing to effectively inhibit the initiation and propagation of corrosion at the damage point, severely limiting their long-term protective reliability. Summary of the Invention

[0005] The present invention aims to at least solve one of the technical problems existing in the prior art, and provides a method for regulating the anti-corrosion protective layer of marine facilities that adapts to strong salt spray environment.

[0006] This invention provides a method for regulating the anti-corrosion protective layer of marine facilities adapted to strong salt spray environments, comprising the following steps:

[0007] (1) Preparation of self-activated intermediate paint: The self-activated intermediate paint is composed of a main agent and a curing agent;

[0008] The main agent, by mass percentage, consists of the following components:

[0009] Bisphenol A type epoxy resin 30%–40%;

[0010] Dual-triggered mineralization precursors: 5%–12%;

[0011] Pigments and fillers 30%–35%;

[0012] Organic solvents 10%–15%;

[0013] Additives 1%–3%;

[0014] The dual-triggered mineralization precursor is composed of BF4. - A composite additive consisting of supported hydrophobically modified zeolite and zinc phosphate-coated water glass microparticles;

[0015] (2) Apply anti-corrosion protective layer: On the surface-treated substrate, apply primer, self-activated intermediate paint obtained by mixing the main agent and curing agent in step (1), and topcoat in sequence, and then cure.

[0016] By employing the above technical solution, this invention constructs a characteristic environment (high pH, ​​high Cl) of corroded micro-regions that can withstand coating damage after the coating has been damaged. - The collaborative self-healing system activated by BF4. - A dual-trigger mineralization precursor, consisting of hydrophobically modified zeolite and zinc phosphate-coated water glass microparticles, enables active protection and repair of damaged areas when the coating suffers scratches or other damage. Its specific mechanism of action is as follows:

[0017] When the coating is damaged, the metal substrate is exposed to an oxygen-containing electrolyte (seawater or salt spray), which rapidly forms corrosion microcells. In the anodic region (where the substrate is exposed), a metal dissolution reaction occurs (Fe → Fe). 2+ +2e - In the cathode region (the coating / substrate interface at the edge of the scratch), an oxygen reduction reaction occurs (O2 + 2H2O + 4e). - →4OH - This results in two key environmental features appearing simultaneously in the scratched area: OH caused by the cathodic reaction. - Enrichment, creating a localized high pH environment; and high concentrations of Cl brought in by seawater. - .

[0018] This corrosive microenvironment precisely triggered a synergistic response from two functional components in the intermediate coating:

[0019] (1) pH buffering and cathode stripping inhibition: High pH environment first activates BF4 - Supported hydrophobically modified zeolite. Its surface hydrophobic layer can be disrupted by highly alkaline environments, allowing OH-... - Entering the zeolite channels. BF4 loaded within them. -The ions undergo hydrolysis, consuming OH-. - This allows for active buffering and downregulation of the interface pH.

[0020] BF4 - +H2O [BF3OH] - +HF;

[0021] This reaction and its subsequent products can effectively neutralize the OH generated by the cathode reaction. - This prevents excessive increase in pH at the coating / substrate interface, fundamentally inhibiting epoxy resin hydrolysis and substrate adhesion loss caused by high alkalinity, and significantly improving the coating's resistance to cathodic disbondment.

[0022] (2) Controlled release and in-situ mineralization plugging: Zinc phosphate-coated water glass particles, whose outer shells are exposed to high pH or high Cl- concentrations in a single environment. - It remains stable in the environment, but exhibits high pH and high Cl at the scratch site. - When both conditions coexist, the coating layer dissolves rapidly. A high pH environment disrupts the chemical stability of phosphates, while Cl... - With dissolved Zn 2+ Formation of a soluble complex ([ZnCl4)) 2- This synergistic effect accelerated the disintegration of the coating layer. After the coating layer failed, the core water glass particles were exposed to a high pH environment and dissolved rapidly, releasing large amounts of silicate ions (SiO3). 2- ).

[0023] (3) Damage repair: The released silicate ions will react with cations in the corrosive environment (Ca from seawater) 2+ Mg 2+ And Fe from the anodic reaction 2+ / Fe 3+ A chemical reaction occurs, forming a dense, water-insoluble silicate mineralization product layer (such as xCaO·yMgO·zFe2O3·nSiO2·mH2O) in situ on the surface of the scratched substrate.

[0024] Therefore, through the above synergistic effect, the in-situ generated mineralized layer can physically seal scratches and isolate the corrosive medium from contact with the metal substrate, thereby preventing further corrosion and realizing active and spontaneous repair of coating damage, significantly extending the service life of the entire protection system.

[0025] Furthermore, in the dual-triggered mineralization precursor, BF4 - The mass ratio of the supported hydrophobically modified zeolite to the zinc phosphate-coated water glass particles was (1.5–2):1.

[0026] By adopting the above technical solution, this mass ratio ensures a balance between pH buffering capacity and mineral supply capacity in the system, which can both respond quickly and suppress cathode stripping, and provide sufficient mineral precursors to form a dense sealing layer.

[0027] Furthermore, the BF4 - The zeolite in the loaded hydrophobically modified zeolite is a Y-type molecular sieve zeolite or a ZSM-5 type molecular sieve zeolite.

[0028] By adopting the above technical solutions, Y-type and ZSM-5 type zeolites possess high specific surface area and regular pore structure, which is beneficial for BF4. - The effective loading and subsequent ion exchange / reaction ensure the efficiency of the pH buffering function.

[0029] Furthermore, the BF4 - The supported hydrophobically modified zeolite was hydrophobically modified by γ-(2,3-epoxypropoxy)propyltrimethoxysilane.

[0030] By adopting the above technical solution, the silane coupling agent can form a stable hydrophobic organic film on the zeolite surface, which enhances its dispersion compatibility in coating resins and ensures its latent stability under normal storage and service conditions, and is only activated in a strongly alkaline corrosive microenvironment.

[0031] Furthermore, the water glass particles coated with zinc phosphate are obtained by spray drying of an aqueous sodium silicate solution with a modulus of 3.1 to 3.4, and the pH value of the zinc phosphate coating reaction system is controlled at 5.8 to 6.2 during the preparation step.

[0032] By adopting the above technical solution and limiting the water glass modulus and the pH value of the coating reaction, it is possible to prepare core-shell structured microparticles with uniform size, dense and complete coating layer, which is the structural basis for realizing their dual triggering and controllable release function.

[0033] Furthermore, the curing agent is a cashew phenol modified amine curing agent, and the mass ratio of the main agent to the cashew phenol modified amine curing agent is (4-5):1.

[0034] By adopting the above technical solution, the cashew phenol modified amine curing agent has excellent water resistance and flexibility. The paint film formed by curing with epoxy main agent in this ratio has excellent physical properties, providing a good matrix environment for the stable existence and function of functional fillers.

[0035] Furthermore, the primer is an epoxy zinc-rich primer, and the topcoat is a polyurethane topcoat. The dry film thickness formed after the self-activated intermediate paint cures is 140μm to 220μm.

[0036] By adopting the above technical solution, the epoxy zinc-rich primer provides cathodic protection, and the polyurethane topcoat provides excellent weather resistance, forming a complete and complementary heavy-duty anti-corrosion system. Limiting the thickness of the intermediate coat ensures that the system contains sufficient self-healing components while complying with industry standards for marine engineering coatings.

[0037] Compared with existing technologies, the method for regulating the anti-corrosion protective layer of marine facilities adapted to strong salt spray environments proposed in this invention has the following beneficial effects:

[0038] 1. This invention endows the protective layer with the ability to actively repair itself and inhibit corrosion propagation after damage. This ability stems from a dual-trigger mineralization precursor added to the intermediate varnish. At the site of coating damage, the zinc phosphate-coated water glass particles in this precursor can controllably release silicate ions in response to the high pH and high chloride ion environment of the corrosion micro-region. These ions then react in situ with metal cations in the environment to generate a dense mineralization product layer. This product layer physically seals the damaged area, effectively preventing the intrusion of corrosive media.

[0039] 2. This invention significantly improves the adhesion stability and cathodic disbondment resistance of the protective layer in the damaged area. This is achieved by introducing BF4... - The hydrophobically modified zeolite, when subjected to cathodic reactions at the damaged site leading to an increase in interfacial pH, can rapidly consume hydroxide ions, effectively buffering the local pH. This effect inhibits the chemical degradation of the epoxy resin matrix and the damage to the substrate / coating interface caused by the highly alkaline environment, thereby maintaining the adhesion of the coating in harsh corrosive environments.

[0040] 3. The self-healing functional component of this invention possesses high storage stability and precise controllability in environmental response, BF4 - The hydrophobic modification of the zeolite-loaded material and the zinc phosphate coating of the water glass microparticles ensure that these two functional substances remain inert during the production, storage, and normal service of the coating, preventing premature failure or adverse reactions with the coating system. Their function is precisely triggered only in the specific corrosive microenvironment formed after coating damage, enabling on-demand release of the repair agent and guaranteeing the long-lasting and efficient self-healing function. Detailed Implementation

[0041] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to specific embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the described 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.

[0042] Unless otherwise specifically stated, the technical or scientific terms used in the embodiments of this invention should be understood in their ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains. The terms "comprising" or "including," as used in the embodiments of this invention, do not limit the shapes, numbers, steps, actions, operations, components, elements, and / or groups thereof mentioned, nor do they exclude the appearance or addition of one or more other different shapes, numbers, steps, actions, operations, components, elements, and / or groups thereof, or the inclusion of these.

[0043] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention. It should also be understood that techniques, methods, and apparatus known to those skilled in the art may not be discussed in detail, but where appropriate, the illustrated techniques, methods, and apparatus should be considered part of the specification. In all the examples shown and discussed herein, any other specific example may have different values.

[0044] In the description of the embodiments of the present invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In the embodiments of the present invention, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in the embodiments of the present invention, as well as the features of different embodiments or examples.

[0045] The main raw materials and reagents used in the following examples and comparative examples have the following sources and specifications. Reagents not specifically mentioned are all commercially available analytical grade or higher grade products.

[0046] Bisphenol A type epoxy resin (CAS No.: 25068-38-6) has an epoxy equivalent of 450 g / eq to 500 g / eq and a number average molecular weight (Mn) of approximately 900 g / mol.

[0047] Cashew phenol modified amine curing agent is a phenolic amine modified fatty amine curing agent with an active hydrogen equivalent of 100 g / eq to 120 g / eq and an amine value of 280 mg KOH / g to 320 mg KOH / g.

[0048] Y-type molecular sieve zeolite is a sodium ion (NaY) powder with a silicon dioxide to aluminum oxide molar ratio (silicon-aluminum ratio) of 5.0 to 6.0 and an average particle size of 3 μm to 5 μm.

[0049] ZSM-5 type molecular sieve zeolite is a sodium ion type powder with a silicon dioxide to aluminum oxide molar ratio (silicon-aluminum ratio) of 25 to 30 and an average particle size of 3 μm to 5 μm.

[0050] Water glass solution, also known as sodium silicate aqueous solution (CAS No.: 1344-09-8), has a molar ratio (modulus) of silicon dioxide to sodium oxide of 3.1 to 3.4 and a Baume degree of 38 to 42.

[0051] Preparation Example A: BF4 - Preparation of supported hydrophobically modified zeolite (component A)

[0052] Preparation Example A1:

[0053] This preparation example provides a BF4 - A method for preparing supported hydrophobically modified Y-type zeolite includes the following steps:

[0054] (1) Take 100g of Y-type molecular sieve zeolite powder and dry it in an oven at 115℃ for 5h.

[0055] (2) Add the dried zeolite powder to 600 mL of a 20% tetrafluoroboric acid aqueous solution.

[0056] (3) The reaction was carried out in a water bath at 65°C with mechanical stirring at a rate of 250 rpm for 24 h.

[0057] (4) After the reaction is complete, the solid product is collected by vacuum filtration, and washed repeatedly with deionized water until the pH of the filtrate is 6.5-7.0. Then, it is dried under vacuum at 105℃ for 10 h to obtain BF4. - Loaded zeolite powder.

[0058] (5) Disperse the dried powder in 500 mL of a mixed solvent of ethanol and deionized water in a volume ratio of 95:5 to form a suspension.

[0059] (6) Take 2.0g of γ-(2,3-epoxypropoxy)propyltrimethoxysilane, dilute it with a small amount of mixed solvent, and slowly add it dropwise to the zeolite suspension.

[0060] (7) Stir the reaction at 300 rpm for 3.5 h at 60 °C.

[0061] (8) After the reaction is complete, the product is collected by vacuum filtration, washed twice with anhydrous ethanol, and finally dried under vacuum at 75°C for 7 hours to obtain the final product.

[0062] Preparation Example A2:

[0063] This preparation example provides a BF4 -The preparation method of the hydrophobically modified Y-type zeolite is basically the same as that of the preparation example A1, except that the reaction temperature in step (3) is 75℃.

[0064] Preparation Example A3:

[0065] This preparation example provides a BF4 - The preparation method of the hydrophobically modified ZSM-5 zeolite is basically the same as that in preparation example A1, except that:

[0066] (1) The raw material in step (1) is 100g of ZSM-5 type molecular sieve zeolite powder.

[0067] (2) The reaction temperature in step (3) is 70℃.

[0068] Preparation Example B: Preparation of Zinc Phosphate-Coated Water Glass Microparticles (Component B)

[0069] Preparation Example B1:

[0070] This preparation example provides a method for preparing zinc phosphate-coated water glass microparticles, including the following steps:

[0071] (1) A water glass solution with a modulus of 3.2 was prepared into spherical particles with an average particle size of 15 μm by spray drying. The inlet air temperature of the spray drying was 190℃ and the outlet air temperature was 110℃.

[0072] (2) Take 100g of the above water glass particles and disperse them in 400mL of isopropanol to form a suspension, and transfer it to the reaction vessel.

[0073] (3) Raise the temperature of the reactor to 50°C and stir at a rate of 350 rpm.

[0074] (4) Using a peristaltic pump, add 1.2 mol / L zinc chloride aqueous solution and 0.7 mol / L phosphoric acid aqueous solution dropwise to the suspension at a flow rate of 8 mL / min. During the dropwise addition, adjust the pH value of the system in real time with dilute ammonia water to stabilize it at 5.8.

[0075] (5) After the addition is complete, continue the reaction under these conditions for 2.5 hours.

[0076] (6) After the reaction is complete, the product is collected by vacuum filtration, washed with deionized water and anhydrous ethanol in sequence, and finally dried under vacuum at 65°C for 12 hours to obtain the final product.

[0077] Preparation Example B2:

[0078] This preparation example provides a method for preparing zinc phosphate coated water glass microparticles. The preparation steps are basically the same as those in preparation example B1, except that the pH value in step (4) is stable at 6.2 during the dropwise addition process, and the reaction time in step (5) is 1.5 h.

[0079] Preparation Example B3:

[0080] This preparation example provides a method for preparing zinc phosphate-coated water glass microparticles. The preparation steps are basically the same as those in Preparation Example B1, except that:

[0081] (1) The inlet air temperature of the spray drying in step (1) is 210℃ and the outlet air temperature is 120℃.

[0082] (2) The pH value during the dropwise addition process in step (4) is stable at 6.0.

[0083] (3) The reaction time in step (5) is 2.0 h.

[0084] Example 1:

[0085] This embodiment provides a method for regulating the anti-corrosion protective layer of marine facilities to adapt to strong salt spray environments, including the following steps:

[0086] (1) Preparation of self-activated intermediate varnish:

[0087] (1.1) Preparation of composite additive: BF4 obtained in preparation example A1 was used. - The hydrophobically modified Y-type zeolite (component A) and the zinc phosphate-coated water glass microparticles (component B) prepared in Preparation Example B1 were physically blended at a mass ratio of A:B=1.5:1 to obtain a dual-triggered mineralization precursor composite additive.

[0088] (1.2) Preparation of intermediate paint component A: The formulation of intermediate paint component A, by mass percentage, includes: 35.0% bisphenol A type epoxy resin, 12.0% titanium dioxide, 22.2% barium sulfate / talc, 8.0% dual-triggered mineralization precursor, 1.0% polymer wetting and dispersing agent, 0.8% hydrogenated castor oil rheology modifier, and 11.0% xylene / n-butanol (3:1) mixed solvent.

[0089] (1.3) Preparation process: The epoxy resin and solvent of the formula amount were added to the dispersion vessel and stirred to dissolve. Then, titanium dioxide, barium sulfate, talc powder and wetting and dispersing agent were added and dispersed at a high speed of 2000 rpm for 30 min. The mixture was pumped into a horizontal sand mill for grinding until the fineness of the paint slurry was ≤50 μm. The ground paint slurry was transferred back to the stirring vessel, and the double-triggered mineralization precursor and hydrogenated castor oil rheology modifier were added under low-speed stirring. Stirring was continued for 25 min until the system was homogeneous to obtain component A.

[0090] (2) Application and curing of the coating system:

[0091] (2.1) Substrate treatment: Q235 carbon steel plate is sandblasted to Sa2.5 grade, and the surface roughness is controlled between 40μm and 70μm.

[0092] (2.2) Coating Application: Apply primer, intermediate coat, and topcoat sequentially. The dry film thickness of the epoxy zinc-rich primer is controlled at 80±10μm. The intermediate coat component A prepared in step (1) is mixed with cashew phenol modified amine curing agent at a mass ratio of 4:1 and cured for 20 minutes before spraying. The dry film thickness is controlled at 180±20μm. The dry film thickness of the polyurethane topcoat is controlled at 70±10μm.

[0093] (2.3) Curing: The prepared coating sample was cured for 14 days at a temperature of 25±2℃ and a relative humidity of 60±5% for later use.

[0094] Example 2:

[0095] This embodiment provides a method for regulating the anti-corrosion protective layer of marine facilities to adapt to strong salt spray environments, including the following steps:

[0096] (1) Preparation of self-activated intermediate varnish:

[0097] (1.1) Preparation of composite additive: BF4 obtained in preparation example A3 was used. - A composite additive was obtained by physically blending hydrophobically modified ZSM-5 zeolite (component A) with zinc phosphate coated water glass microparticles (component B) prepared in preparation example B2 at a mass ratio of A:B=2:1.

[0098] (1.2) Preparation of intermediate paint component A: The formulation of intermediate paint component A, by mass percentage, includes: 30.0% bisphenol A type epoxy resin, 15.0% titanium dioxide, 19.5% barium sulfate / talc, 12.0% dual-triggered mineralization precursor, 1.5% polymer wetting and dispersing agent, 1.0% hydrogenated castor oil rheology modifier, and 11.0% xylene / n-butanol (3:1) mixed solvent.

[0099] (1.3) Preparation process: The epoxy resin and solvent of the formula amount were added to the dispersion vessel and stirred to dissolve. Then, titanium dioxide, barium sulfate, talc powder and wetting and dispersing agent were added and dispersed at a high speed of 2200 rpm for 35 min. The mixture was pumped into a horizontal sand mill for grinding until the fineness of the paint slurry was ≤50 μm. The ground paint slurry was transferred back to the stirring vessel, and the composite additive and hydrogenated castor oil rheology modifier were added under low speed stirring. The stirring was continued for 30 min until the system was homogeneous, and component A was obtained.

[0100] (2) Application and curing of the coating system:

[0101] (2.1) Substrate treatment: Same as in Example 1.

[0102] (2.2) Coating Application: Apply primer, intermediate coat, and topcoat sequentially. The dry film thickness of the epoxy zinc-rich primer is controlled at 80±10μm. The intermediate coat component A prepared in step (1) is mixed with cashew phenol modified amine curing agent at a mass ratio of 4:1 and cured for 20 minutes before spraying. The dry film thickness is controlled at 200±20μm. The dry film thickness of the polyurethane topcoat is controlled at 70±10μm.

[0103] (2.3) Curing: Same as in Example 1.

[0104] Example 3:

[0105] This embodiment provides a method for regulating the anti-corrosion protective layer of marine facilities to adapt to strong salt spray environments, including the following steps:

[0106] (1) Preparation of self-activated intermediate varnish:

[0107] (1.1) Preparation of composite additive: BF4 obtained in preparation example A2 was used. - The hydrophobically modified Y-type zeolite (component A) and the zinc phosphate-coated water glass microparticles (component B) prepared in Preparation Example B3 were physically blended at a mass ratio of A:B=2:1 to obtain a composite additive.

[0108] (1.2) Preparation of intermediate paint component A: The formulation of intermediate paint component A, by mass percentage, includes: 38.0% bisphenol A type epoxy resin, 10.0% titanium dioxide, 23.7% barium sulfate / talc, 5.0% dual-triggered mineralization precursor, 0.8% polymer wetting and dispersing agent, 0.5% hydrogenated castor oil rheology modifier, and 12.0% xylene / n-butanol (3:1) mixed solvent.

[0109] (1.3) Preparation process: The epoxy resin and solvent of the formula amount were added to the dispersion vessel and stirred to dissolve. Then, titanium dioxide, barium sulfate, talc powder and wetting and dispersing agent were added and dispersed at a high speed of 1800 rpm for 25 min. The mixture was pumped into a horizontal sand mill for grinding until the fineness of the paint slurry was ≤50 μm. The ground paint slurry was transferred back to the stirring vessel, and the composite additive and hydrogenated castor oil rheology modifier were added under low speed stirring. The stirring was continued for 20 min until the system was homogeneous, and component A was obtained.

[0110] (2) Application and curing of the coating system:

[0111] (2.1) Substrate treatment: Same as in Example 1.

[0112] (2.2) Coating Application: Apply primer, intermediate coat, and topcoat sequentially. The dry film thickness of the epoxy zinc-rich primer is controlled at 80±10μm. Mix the intermediate coat component A prepared in step (1) with the cashew phenol modified amine curing agent at a mass ratio of 5:1 and allow it to mature for 25 minutes before spraying. The dry film thickness is controlled at 160±20μm. The dry film thickness of the polyurethane topcoat is controlled at 70±10μm.

[0113] (2.3) Curing: Same as in Example 1.

[0114] Comparative Example 1:

[0115] Compared with Example 1, the difference is that in the preparation process of its self-activated intermediate paint, no dual-triggered mineralization precursor composite additive is added, but barium sulfate of equal mass is used instead, while the rest are the same.

[0116] Comparative Example 2:

[0117] Compared with Example 1, the difference is that in the preparation process of its self-activated intermediate paint, the composite additive consists only of the zinc phosphate coated water glass particles (component B) obtained in Preparation Example B1, without adding component A, and the amount of component B added is the same as that of component B in Example 1, and all other aspects are the same.

[0118] Comparative Example 3:

[0119] The difference compared to Example 1 is that, in the preparation process of its self-activated intermediate paint, the composite additive is only BF4 obtained in Preparation Example A1. - The mixture consists of hydrophobically modified Y-type zeolite (component A), without the addition of component B. The amount of component A added is the same as that of component A in Example 1, and all other components are the same.

[0120] Comparative Example 4:

[0121] The difference from Example 1 is that component B in its composite additive is replaced with uncoated zinc phosphate water glass microparticles. These water glass microparticles are obtained only by spray drying in step (1) of Preparation Example B1, and all other steps are the same.

[0122] Comparative Example 5:

[0123] Compared with Example 1, the difference is that in the preparation process of its self-activated intermediate paint, the dual-triggered mineralization precursor composite additive is not added, but is replaced by an equal mass of aluminum tripolyphosphate (commercial corrosion inhibitor), while the rest are the same.

[0124] Test Example 1:

[0125] The experimental steps are as follows:

[0126] 1. Solution preparation: A 0.01 mol / L sodium hydroxide (NaOH) standard solution was used, and its initial pH value was calibrated to 12.00 ± 0.02 using a high-precision pH meter (accuracy ± 0.01).

[0127] 2. Experimental Grouping: Take two 250mL beakers and add 100mL of the prepared NaOH solution to each. Label one beaker as the blank group. Add 1.0g of the BF4-supported hydrophobic modified Y-type zeolite powder prepared in Preparation Example A1 to the other beaker and label it as the experimental group.

[0128] 3. Experimental condition control: Both beakers were placed in a constant temperature water bath at 25℃ and a magnetic stir bar of the same size was placed inside. The beakers were stirred synchronously at a speed of 300 rpm to eliminate the influence of temperature and diffusion on the experimental results.

[0129] 4. Data Monitoring: Starting from the moment the powder was added to the experimental group (recorded as 0h), the pH value of the solution in both beakers was monitored simultaneously using a calibrated pH meter. pH readings were recorded at time points of 0h, 0.2h, 0.5h, 1h, 2h, 3h, 4h, 5h, and 6h.

[0130] The experimental results are shown in Table 1.

[0131] Table 1. pH value change of component A in solution at pH=12.0 over time:

[0132]

[0133] The test data in Table 1 show that in an alkaline solution with an initial pH of 12.0, the pH value of the blank group remained relatively stable over the 6-hour test period, fluctuating between 11.97 and 12.01, demonstrating the stability of the experimental system itself. In contrast, the experimental group containing the product of preparation example A1 (component A) showed a significant and continuous decrease in pH. Within 1 hour of the start of the test, the pH value rapidly decreased from 12.00 to 10.35, demonstrating the rapid response characteristics of this component in an alkaline environment. Over the following 5 hours, the pH value continued to decrease slowly, eventually stabilizing at around 9.51, indicating that the reaction tended to reach equilibrium.

[0134] The decrease in pH value is due to the tetrafluoroborate ions (BF4) loaded in component A. - Hydrolysis reaction occurred (BF4) - +H2O [BF3OH] - +HF, and subsequent reactions), this series of reactions consumes hydroxide ions (OH-) in the solution. - This leads to a decrease in the macroscopic pH value of the solution.

[0135] In the simulated highly alkaline environment created by micro-regions of coating damage and corrosion, component A can be effectively activated and actively consume OH groups. - This pH buffering effect is crucial for suppressing cathodic disbondment induced by a highly alkaline environment. Therefore, this test case confirms that component A possesses a pre-defined alkaline neutralization function triggered by a high pH environment.

[0136] Test Example 2:

[0137] The experimental steps are as follows:

[0138] 1. Solution preparation: Prepare the following four test solutions:

[0139] Solution 1: Deionized water.

[0140] Solution 2: Dissolve 3.5g of sodium chloride (NaCl) in 96.5g of deionized water to prepare a 3.5% NaCl solution.

[0141] Solution 3: Use a 0.01 mol / L sodium hydroxide (NaOH) standard solution, with the pH calibrated to 12.00 ± 0.02.

[0142] Solution 4: Dissolve 3.5g of NaCl in 96.5g of pH=12.00 NaOH solution.

[0143] 2. Experimental Grouping and Conditions: Take four 250mL Erlenmeyer flasks and add 100mL of the four solutions mentioned above to each flask. Add 1.0g of the zinc phosphate-coated water glass microparticle powder prepared in Preparation Example B1 to each Erlenmeyer flask. Place all Erlenmeyer flasks in a constant temperature shaker at 25℃ and shake at a rate of 150rpm for 24h.

[0144] 3. Sample preparation: After shaking, transfer the suspensions from each group to centrifuge tubes and centrifuge at 5000 rpm for 10 min. Carefully aspirate the supernatant and filter it through a 0.22 μm microporous membrane to remove any residual fine particles.

[0145] 4. Composition analysis: Inductively coupled plasma optical emission spectrometry (ICP-OES) was used to perform elemental analysis on the filtered supernatant to quantitatively determine the concentration of silicon (Si).

[0146] The experimental results are shown in Table 2.

[0147] Table 2. Si dissolution concentration of component B in different solutions:

[0148]

[0149] Table 2 shows the dissolution behavior of component B. In deionized water (solution 1) and a single NaCl solution (solution 2), the dissolution concentration of Si was extremely low, at 1.32 mg / L and 1.89 mg / L respectively, which are at background levels. In a single high-pH NaOH solution (solution 3), the Si concentration increased slightly to 2.54 mg / L, but remained at a very low level. This indicates that neither the high concentration of chloride ions in a neutral environment nor the highly alkaline environment without chloride ions could effectively disrupt the coating structure of component B, and its core water glass material did not undergo significant dissolution.

[0150] In solution 4, which simultaneously exhibits high pH and high chloride ion concentration, the leaching concentration of Si element increased dramatically to 157.81 mg / L, a value that is tens to hundreds of times higher than the leaching concentration under the other three conditions.

[0151] This result confirms the dual-trigger release mechanism designed for component B, whose surface zinc phosphate coating is effective against a single corrosion factor (high Cl). - or high OH - The coating maintains structural stability under the influence of [a specific chemical process], thus endowing this functional component with high stability in coating storage and normal service environments. Rapid dissolution of the coating only occurs when the coating is damaged, a corrosion micro-cell is established, and the damaged area simultaneously experiences a localized high pH environment caused by the cathodic reaction and a high concentration of chloride ions from an electrolyte (such as seawater). The high pH environment disrupts the chemical stability of the phosphate, while chloride ions form a soluble complex with zinc ions ([ZnCl4]). 2- This accelerates the disintegration of the coating layer. Once the coating layer fails, the internal water glass core is exposed and rapidly dissolves in the alkaline environment, releasing a large number of silicate ions, which provide a source of material for subsequent mineralization and sealing reactions.

[0152] Therefore, this test case verifies that component B has an environmentally responsive and controllable release function. Its activation conditions are highly matched with the characteristic environment of the real corrosion micro-zone, ensuring that the mineralization precursor can be released at the right time and place, avoiding premature failure and waste of functional components.

[0153] Test Example 3:

[0154] The experimental steps are as follows:

[0155] 1. Sample Preparation: Using a blade, a 20mm long, approximately 1mm wide, and deep scratch reaching the metal substrate was made in the center of the coated samples from Examples 1-3 and Comparative Examples 1-5. The edges and back of the samples were sealed with epoxy resin, leaving only a 10cm deep groove. 2 The scratched area serves as the test surface.

[0156] 2. Electrochemical testing system: A three-electrode system was used for testing. The scratch sample was used as the working electrode, a platinum sheet as the auxiliary electrode, and a saturated calomel electrode (SCE) as the reference electrode. The test medium was a 3.5% NaCl solution.

[0157] 3. Test Parameters: Electrochemical impedance spectroscopy (EIS) tests were performed on days 1, 7, 15, and 30 after the sample was immersed in the solution. Before each test, the open circuit potential (OCP) was monitored for stabilization for 30 minutes. The frequency range of the EIS tests was 10 Hz. 5 The applied AC disturbance signal amplitude is 10mV and ranges from Hz to 0.01Hz.

[0158] 4. Data Acquisition: Record EIS data at different immersion time points and extract the low-frequency impedance modulus (|Z|) at 0.01Hz. 0.01 (Hz), used to evaluate the overall protective performance of the coating.

[0159] The experimental results are shown in Table 3.

[0160] Table 3. Low-frequency impedance modulus (|Z|) of different coated samples during immersion in 3.5% NaCl solution 0.01 Hz):

[0161]

[0162] Low-frequency impedance magnitude |Z| 0.01 Hz directly reflects the resistance of the electrolyte to penetrate the coating and reach the substrate interface. Table 3 shows that after scratching and soaking for one day, the resistance values ​​of all coatings were lower than those of the intact coating (typically >10). 9 Ω·cm 2 The significant decrease is due to the fact that scratches directly expose the metal substrate, creating corrosion channels.

[0163] The coating systems in Examples 1, 2, and 3 exhibit unique impedance evolution behavior. Their |Z| 0.01 After an initial decrease, the Hz value showed a significant and sustained increase with prolonged soaking time. For example, the impedance value in Example 2 increased from an initial 6.03 × 10⁻⁶. 5 Ω·cm 2 Increased to 1.98 × 10⁻⁶ on day 30 7 Ω·cm 2 This represents an improvement of more than an order of magnitude. This spontaneous recovery of impedance is direct evidence of the effective self-repair of the coating at the scratch site. The mechanism lies in the fact that the activity of corrosion micro-cells at the scratch site generates locally high pH and high Cl... -The microenvironment triggered a synergistic response between components A and B in the intermediate coat. Silicate ions released by component B reacted with calcium and magnesium ions from seawater and iron ions dissolved from the substrate, depositing a dense mineralized product layer inside the scratch. This product layer physically blocked the corrosion channels, hindering the intrusion of corrosive media and thus restoring the coating's resistance.

[0164] In contrast, the coating impedance of all comparative examples showed a continuous decreasing trend. The impedance of Comparative Example 1 (blank sample) decreased rapidly, indicating that it lacked any active protection capability. The impedances of Comparative Example 2 (missing component A) and Comparative Example 3 (missing component B) also decreased continuously, demonstrating the necessity of the pH buffer component and the mineralization source component, as well as the importance of their synergistic effect. Without either component, an effective sealing layer could not be formed. The impedance of Comparative Example 4 (single triggering mechanism) decreased rapidly, indicating that the premature or ineffective release of uncoated water glass failed to form a stable and dense protective layer, highlighting the superiority of the dual-trigger controlled-release mechanism of this invention. Comparative Example 5 (conventional corrosion inhibitor) showed a certain corrosion inhibition effect in the early stages of immersion, with a lower impedance decrease rate than the blank sample. However, as the corrosion inhibitor was consumed, its protective capability gradually diminished, and the impedance value eventually dropped to a low level.

[0165] In summary, by introducing latent functional components into the intermediate coating, this invention achieves intelligent response and active repair to coating damage, and its long-term protective effect is significantly better than that of traditional passive protective coatings or single corrosion inhibitor protective coatings.

[0166] Test Example 4:

[0167] The experimental steps are as follows:

[0168] 1. Sample Preparation: Take the coated samples from Examples 1-3 and Comparative Examples 1, 2, 4, and 5, and use an electric drill to create a 6mm diameter through hole in the center of the sample as an artificial defect. Seal the edges and back of the sample.

[0169] 2. Testing Apparatus: The prepared sample was used as the working electrode (cathode), a saturated calomel electrode (SCE) as the reference electrode, and a platinum sheet as the auxiliary electrode, forming a three-electrode electrolytic cell. The test electrolyte was a 3.5% NaCl solution, and the test temperature was maintained at 25℃.

[0170] 3. Constant potential application: Connect the electrolytic cell to a potentiostat and apply a constant cathode polarization potential of -1.5V to the working electrode for 30 days.

[0171] 4. Peel Assessment: After the test cycle, remove the sample, gently rinse with deionized water, and dry it. Using a sharp knife, attempt to lift and peel the coating from the edge of the artificial defect. Measure the distance from the boundary of the peeled area to the edge of the original defect, taking measurements at least 8 points along the circumference, and calculate the average value as the average peel radius of the sample.

[0172] The experimental results are shown in Table 4.

[0173] Table 4. Test results of coating resistance to cathodic disbondment:

[0174]

[0175] The quantitative test results in Table 4 show that after 30 days of constant cathodic polarization, the average peel radius of the coatings in Examples 1, 2, and 3 was controlled within 4.0 mm, which was significantly smaller than that of all comparative sample samples.

[0176] Cathodic stripping is a major failure mode of coatings under cathodic protection conditions. Its fundamental driving force is the oxygen reduction reaction (O2 + 2H2O + 4e) that occurs in the cathodic region (such as artificial defects). - →4OH - This leads to OH groups at the interface between the coating and the metal substrate. - The accumulation of ions creates a locally highly alkaline environment. This high pH environment saponifies or hydrolyzes functional groups such as ester groups in the coating resin and disrupts the stability of the oxide layer on the substrate surface, ultimately leading to loss of coating adhesion and peeling.

[0177] The excellent resistance to cathodic disbondment exhibited by the coating in the embodiments of the present invention is due to component A (BF4) in the intermediate varnish. - The supported zeolite played a crucial pH buffering role. When the pH at the defect site increased due to the cathodic reaction, component A was activated and reacted with OH-. - The reaction effectively neutralized excess alkali at the interface, thereby inhibiting the deterioration of interfacial adhesion. Test Example 1 has confirmed that component A possesses this function.

[0178] Comparative Example 1 (blank control) and Comparative Example 4 (component B coating failure) lacked an effective pH adjustment mechanism and exhibited the largest peel radius, indicating rapid deterioration of the interfacial environment under strong cathodic polarization. Comparative Example 2, lacking the crucial pH buffer component A, had a peel radius as high as 15.9 mm, showing no significant difference from the blank sample. This directly proves that component A is the core component for achieving cathodic disbondment resistance. Comparative Example 5 used a traditional corrosion inhibitor, which, while having some inhibitory effect on anodic corrosion, did not effectively neutralize the OH generated by the cathodic reaction. - Due to its limited capabilities, its resistance to cathode stripping is far inferior to that of the embodiments of the present invention.

[0179] In summary, the results of the cathodic disbondment test verify the effectiveness of the present invention in actively regulating the microenvironment at the defect site by introducing a pH-responsive buffer. This strategy fundamentally suppresses the key destructive factors that lead to coating disbondment and significantly improves the long-term reliability and adhesion stability of the coating when used in conjunction with a cathodic protection system or in the presence of localized corrosion cells.

[0180] Test Example 5:

[0181] The experimental steps are as follows:

[0182] 1. Sample preparation: Take the coating samples of Examples 1-3 and Comparative Examples 1-5, and use a special scribing tool to scribing an "X" shaped mark on the surface of the sample that penetrates the coating to the metal substrate. The length of the scribing mark should not be less than 50 mm.

[0183] 2. Test Conditions: All samples were placed in a neutral salt spray (NSS) test chamber. According to ISO 9227, the test conditions were set as follows: sodium chloride solution concentration 50±5 g / L, pH value 6.5~7.2, and chamber temperature 35±2℃. Continuous spray testing was conducted for a total of 1000 hours.

[0184] 3. Performance Rating: After testing, remove the sample and gently rinse it with running water to remove any surface salt residue, then allow it to dry. Rating is conducted according to the ISO 4628 standard series.

[0185] 4. Bubble rating (ISO 4628-2): Assess the density and size of bubbles in the coating near the scratch, and record them in the format of "density (size)".

[0186] 5. Rust rating (ISO 4628-3): Assess the rust level of the scratched area.

[0187] 6. Corrosion propagation rating: Gently remove the loosely adhered coating on both sides of the scratch with a scraper, and measure the maximum vertical distance from the edge of the original scratch to the end point of corrosion propagation. This is the maximum corrosion propagation width on one side.

[0188] The experimental results are shown in Table 5.

[0189] Table 5. Coating performance ratings after 1000 hours of neutral salt spray testing:

[0190]

[0191] The results of the neutral salt spray test directly reflect the differences in the macroscopic protective performance of different coating systems under accelerated corrosion environments.

[0192] After undergoing 1000 hours of rigorous testing, the samples in Examples 1, 2, and 3 showed no blistering in the scratched areas, maintained a very low rust level (Ri 1), and effectively controlled the corrosion spread width on both sides of the scratches to within 1.5 mm. This result demonstrates that the coating of the present invention forms an effective protective mechanism at the scratches. The underlying mechanism is that the salt spray environment induces corrosion micro-cells at the scratches, resulting in localized high pH and high Cl levels. - The environment activated the dual-triggered mineralization precursor in the intermediate varnish. Component A neutralized the OH generated in the cathode region. - This suppressed the cathodic stripping tendency of the coating, so no blistering was observed. At the same time, the silicate ions released by component B underwent in-situ mineralization at the scratches, and the resulting dense deposits effectively sealed the corrosion interface, significantly delaying further corrosion of the substrate and corrosion spread under the coating.

[0193] All comparative examples exhibited varying degrees of severe failure. The severe corrosion propagation and blistering in Comparative Example 1 represent a typical failure mode without an active protective coating. Failure data from Comparative Example 2 (missing component A) and Comparative Example 3 (missing component B) demonstrate that the absence of either a pH buffer or a mineral source prevents the construction of an effective synergistic protective system, and corrosion at the scratches cannot be suppressed. The corrosion propagation in Comparative Example 4 (without effective water glass coating) remained severe, indicating that the controlled release capability of the functional material is crucial for effective repair; premature or uncontrolled release cannot form a stable protective layer. Comparative Example 5 (using a traditional corrosion inhibitor) outperformed the other comparative examples, but its 5.6 mm corrosion propagation width was significantly larger than the examples, indicating that the dissolution-adsorption mechanism of traditional corrosion inhibitors is less effective in long-term physical sealing than the in-situ mineralization layer formed by this invention.

[0194] Therefore, the results of the salt spray aging test confirm that the present invention can significantly improve the long-term protective reliability of the coating after damage by constructing a synergistic self-healing system in the coating that is triggered by the corrosion products themselves and integrates pH buffering and in-situ mineralization sealing, and effectively inhibits the corrosion spread and coating aging failure at the scratches.

[0195] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A method for regulating the anti-corrosion protective layer of marine facilities adapted to strong salt spray environments, characterized in that, Includes the following steps: (1) Preparation of self-activated intermediate paint: The self-activated intermediate paint is composed of a main agent and a curing agent; The main agent, by mass percentage, consists of the following components: Bisphenol A type epoxy resin 30%–40%; Dual-triggered mineralization precursors: 5%–12%; Pigments and fillers 30%–35%; Organic solvents 10%–15%; Additives 1%–3%; The dual-triggered mineralization precursor is composed of BF4. - A composite additive consisting of supported hydrophobically modified zeolite and zinc phosphate-coated water glass microparticles; (2) Apply anti-corrosion protective layer: On the surface-treated substrate, apply primer, self-activated intermediate paint obtained by mixing the main agent and curing agent in step (1), and topcoat in sequence, and then cure.

2. The method for regulating the anti-corrosion protective layer of marine facilities adapted to strong salt spray environments according to claim 1, characterized in that, In the dual-triggered mineralization precursor, BF4 - The mass ratio of the supported hydrophobically modified zeolite to the zinc phosphate-coated water glass particles was (1.5–2):

1.

3. The method for regulating the anti-corrosion protective layer of marine facilities adapted to strong salt spray environments according to claim 1, characterized in that, The BF4 - The zeolite in the loaded hydrophobic modified zeolite is a Y-type molecular sieve zeolite or a ZSM-5 type molecular sieve zeolite.

4. The method for regulating the anti-corrosion protective layer of marine facilities adapted to strong salt spray environments according to any one of claims 1 to 3, characterized in that, The BF4 - The supported hydrophobically modified zeolite was hydrophobically modified by γ-(2,3-epoxypropoxy)propyltrimethoxysilane.

5. The method for regulating the anti-corrosion protective layer of marine facilities adapted to strong salt spray environments according to any one of claims 1 to 3, characterized in that, The zinc phosphate-coated water glass particles are prepared by spray drying of an aqueous solution of sodium silicate with a modulus of 3.1 to 3.

4.

6. The method for regulating the anti-corrosion protective layer of marine facilities adapted to strong salt spray environments according to any one of claims 1 to 3, characterized in that, In the preparation steps of the zinc phosphate-coated water glass microparticles, the pH value of the zinc phosphate coating reaction system is controlled at 5.8 to 6.

2.

7. The method for regulating the anti-corrosion protective layer of marine facilities adapted to strong salt spray environments according to any one of claims 1 to 3, characterized in that, The curing agent is a cashew phenol-modified amine curing agent.

8. The method for regulating the anti-corrosion protective layer of marine facilities adapted to strong salt spray environments according to claim 7, characterized in that, The mass ratio of the main agent to the cashew phenol-modified amine curing agent is (4-5):

1.

9. The method for regulating the anti-corrosion protective layer of marine facilities adapted to strong salt spray environments according to any one of claims 1 to 3, characterized in that, The primer is an epoxy zinc-rich primer, and the topcoat is a polyurethane topcoat.

10. The method for regulating the anti-corrosion protective layer of marine facilities adapted to strong salt spray environments according to any one of claims 1 to 3, characterized in that, The thickness of the dry film formed after the self-activated intermediate paint is cured is 140μm to 220μm.

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