Preparation method of filling and coating quick-drying type resin anti-corrosion paint

Abstract

The invention belongs to the field of anti-corrosion materials, and discloses a preparation method of filling and coating quick-drying type resin anti-corrosion paint, according to the anti-corrosion paint, low-boiling-point oil phase microcapsules are introduced into a resin matrix, a micro-channel network is formed, volatilization of an internal solvent and permeation of a cross-linking agent are accelerated, and the surface drying time of a coating is remarkably shortened; an amphoteric oligomer containing a sulfonic acid group is synthesized and self-assembled on the surface of a metal substrate to form a monomolecular interface layer, and covalent grafting is carried out on the monomolecular interface layer and a resin component, so that the interface bonding force is enhanced, and hydrophobic corrosion resistance is achieved; the method is easy and convenient to construct and suitable for large-area filling and thick coating, the anti-corrosion paint coating has the characteristics of quick drying, high adhesion, weather resistance and environmental protection, the field construction efficiency is remarkably improved, and the anti-corrosion service life is remarkably prolonged.

Description

Technical Field

[0001] This invention belongs to the field of anti-corrosion materials, and specifically relates to a method for preparing a quick-drying resin anti-corrosion paint for potting. Background Technology

[0002] Anti-corrosion paint, as an important coating material to protect metal substrates from corrosive media, is widely used in critical engineering fields such as oil and gas pipelines, chemical storage tanks, bridges, and offshore platforms. Traditional epoxy anti-corrosion paint systems are mostly prepared from epoxy resin and amine curing agents, possessing excellent adhesion and chemical resistance. However, in large-volume, thick-coating applications, they suffer from drawbacks such as long surface drying time, low construction efficiency, and difficulty in controlling sagging. To accelerate curing, existing technologies often employ methods such as increasing curing agent activity, adding drying or leveling aids, increasing application temperature, or adding highly volatile solvents. However, these methods significantly increase volatile organic compound (VOC) emissions, hindering environmental compliance. Furthermore, because the curing network only forms on the coating surface or within a thin layer, the solvent evaporation and cross-linking reaction within the thick coating cannot proceed synchronously, resulting in the surface curing first while the inner layers lag behind, leading to cracking, loosening, or even delamination defects, and reducing the overall corrosion resistance life of the coating.

[0003] The quality of the interfacial bonding between the metal substrate and the coating is a key factor affecting weather resistance and delamination resistance. Existing interface modification technologies mainly involve simply coating sulfonates or amine compounds to form a physically adsorbed corrosion inhibitor layer, or using self-assembled monolayer technology to construct a molecular film. Although these methods can improve adhesion in the short term, they often fail in complex environments due to physical desorption or interfacial stress concentration, and cannot maintain high adhesion strength for a long time. Summary of the Invention

[0004] To address the shortcomings mentioned in the background art, the present invention aims to provide a method for preparing a quick-drying resin anti-corrosion paint. This method involves breaking down low-boiling-point aromatic hydrocarbon microcapsules to form a network of interconnected microchannels, accelerating solvent evaporation and crosslinking agent penetration. Simultaneously, a sulfonic acid-based amphoteric oligomer monolayer is self-assembled on the metal surface and covalently grafted onto the resin matrix, achieving rapid surface drying, high adhesion, and excellent corrosion resistance.

[0005] The objective of this invention can be achieved through the following technical solutions: A method for preparing a quick-drying resin anti-corrosion paint for application includes the following steps: S1. Disperse nano-silica in a solvent, add alkoxysilane coupling agent and mix, stir and react, then wash and dry to obtain surface-modified nano-silica; S2. Mix epoxy resin, sulfonic acid-based amphoteric oligomer, and modified nano-silica, add microcapsules and mix, then add leveling agent, defoamer and isopropanol, and stir until the system is clear and homogeneous to obtain component A. S3. Mix the polyisocyanate prepolymer with the drying agent and stir until homogeneous to obtain component B; S4. Pour component A obtained in step S2 into the mixing tank, slowly add component B obtained in step S3, and simultaneously degas until the paint fluid is uniform, which is the quick-drying resin anti-corrosion paint for potting.

[0006] More preferably, the quick-drying resin anti-corrosion paint includes the following raw materials in parts by weight: 80-120 parts epoxy resin, 3-10 parts sulfonic acid amphoteric oligomer, 1-5 parts modified nano silica, 5-15 parts microcapsules, 5-20 parts polyisocyanate prepolymer, 1-3 parts drying agent, 0.5-2 parts leveling agent, 0.1-1 parts defoamer, and 5-20 parts isopropanol.

[0007] More preferably, the mixing temperature in step S4 is 20–30 °C, and the stirring speed is 300–600 rpm.

[0008] More preferably, the preparation method of modified nano-silica specifically includes the following steps: S101. Disperse nano-silica powder in an organic solvent and then use ultrasound to make it uniformly dispersed; S102. Add alkoxysilane coupling agent solution to the dispersion and stir continuously to allow the coupling agent molecules to adsorb and react with the hydroxyl groups on the silicon surface; after the reaction is complete, separate the modified particles by centrifugation or filtration and wash them several times with anhydrous ethanol to remove unreacted coupling agent. S103. The modified nano-silica is dried to obtain surface-modified nano-silica in powder form.

[0009] More preferably, the preparation method of the sulfonic acid-based amphoteric oligomer specifically includes the following steps: S201. Dissolve toluenesulfonate monomer, ethylene oxide and propylene glycol monomer in anhydrous ethanol, add a free radical initiator and carry out free radical polymerization; S202. After the polymerization reaches the designed conversion rate, triethanolamine is added to the reaction system, and the solvent and unreacted substances are removed by distillation or membrane separation. S203. The neutralized crude product was subjected to multiple solvent washings and vacuum drying to obtain sulfonic acid-based amphoteric oligomers with an average molecular weight of 1000-1500 Da.

[0010] More preferably, the method for preparing microcapsules specifically includes the following steps: S301. Low-boiling-point aromatic core material and alkoxysilane precursor are dissolved in an organic phase and dispersed in an aqueous phase containing a stable emulsifier to form a water-in-oil emulsion; S302. A catalyst is added to the emulsion system to promote the condensation polymerization of silane precursors at the oil-water interface to generate a polysilane shell; S303. After the reaction is complete, the aqueous phase is removed by centrifugation or membrane separation, and the microcapsules are washed with water or anhydrous ethanol and dried to obtain polysilane shell low-boiling-point aromatic microcapsules with a shell diameter of 5-10 μm. More preferably, the surface drying time of the anti-corrosion paint is 10-15 minutes at 25 ℃ and 50% relative humidity.

[0011] More preferably, the salt spray resistance of the coating after the anti-corrosion paint has fully dried is not less than 1000 h.

[0012] More preferably, the drying agent is N,N-dimethylethanolamine, the leveling agent is a polyacrylate leveling agent, and the defoamer is an organosilicone defoamer.

[0013] The beneficial effects of this invention are: The microchannel network principle employed in this invention utilizes microcapsules to release low-boiling-point aromatics upon rupture after application, forming interconnected microchannels from the surface to the bottom layer. This effectively accelerates solvent evaporation and isocyanate crosslinking agent penetration within the coating, shortening surface drying time and enabling rapid curing of thick coatings at room temperature while preventing sagging. Sulfonic acid-based amphoteric oligomers self-assemble into monomolecular interface layers on the metal surface and covalently graft epoxy groups with isocyanate groups, constructing a flexible transition region with a gradient crosslinking density. This not only significantly enhances the adhesion between the coating and the substrate but also blocks the penetration of corrosive media through the sulfonic acid ion barrier function, ensuring long-term interface stability. Furthermore, modified nano-silica particles synergistically work with leveling agents, defoamers, and drying agents in the dispersion system to form a dense network with nanoscale filling and pore structure regulation, further enhancing the coating's mechanical strength, self-leveling effect, and wear resistance. Attached Figure Description

[0014] The invention will now be further described with reference to the accompanying drawings.

[0015] Figure 1 Comparison of surface drying and complete drying times of the anti-corrosion paints prepared in Examples 1–3 and Comparative Examples 1–2; Figure 2 Scatter plots showing the quality changes and grades of the anti-corrosion paints prepared in Examples 1–3 and Comparative Examples 1–2; Figure 3 The adhesion retention rate curves of the anti-corrosion paints prepared in Examples 1–3 and Comparative Examples 1–2 after aging are shown. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] Example 1 I. Preparation of Modified Nano-Silica 100 g of nano-silica powder was dispersed in 500 mL of anhydrous ethanol and sonicated for 10 min to break up agglomerates. Separately, 10 g of γ-aminopropyltriethoxysilane (KH-550) was dissolved in 50 mL of anhydrous ethanol to prepare a coupling agent solution. The coupling agent solution was slowly added to the SiO2 dispersion, heated to 60 ℃ and stirred at 500 rpm for 2 h to allow KH-550 molecules to be grafted onto the SiO2 surface through a silanization reaction. After the reaction was completed, the reaction solution was centrifuged at 5000 rpm for 10 min to separate the particles. The supernatant was discarded, and the precipitate was washed twice with anhydrous ethanol to remove the free coupling agent. The precipitate was dried in a vacuum drying oven at 80 ℃ for 4 h to obtain modified nano-silica with a particle size of about 20 nm and amino functional groups on the surface.

[0018] II. Preparation of Sulfonic Acid Amphoteric Oligomers Take 20 g of sodium toluenesulfonate and place it in a stirred reactor. Add 50 mL of anhydrous toluene, purge with nitrogen and stir at 300 rpm. Heat to 70 °C and maintain nitrogen protection. Add 15 g of ethylene oxide and 15 g of propylene glycol in batches, and add 0.5 g of azobisisobutyronitrile as an initiator. Keep warm and stir for 2 h to complete the free radical polymerization reaction of the main monomers.

[0019] After the polymerization reaction was completed, the mixture was allowed to cool naturally to room temperature. 10 mL of triethanolamine was slowly added to the system to neutralize the remaining sulfonate groups to pH 7. Vacuum distillation was performed under vacuum to remove toluene and unreacted monomers in batches until no monomers were detected in the distillate. The neutralized crude product was transferred to a washing container, and 100 mL of anhydrous ethanol was added. The mixture was shaken and washed three times to remove impurities. The washed wet product was then dried in a vacuum drying oven at 60 °C for 6 h to obtain a sulfonic acid-based amphoteric oligomer with an average molecular weight of approximately 1200 Da.

[0020] III. Preparation of Microcapsules 10 g of low-boiling-point aromatic xylene and 5 g of alkoxysilane precursor were weighed and dissolved in 30 mL of anhydrous ethanol and 20 mL of aqueous phase, respectively. 1.0 g of polyvinyl alcohol was added to 500 mL of aqueous phase as a dispersant. After ultrasonic dispersion, the organic phase was slowly added dropwise to form a water-in-oil emulsion. 0.5 mL of ammonia was added to adjust the pH, and the mixture was stirred for 4 h to complete shell gelation. After the reaction was completed, the mixture was centrifuged at 4000 rpm for 5 min to separate the contents. The supernatant was discarded, the precipitate was washed twice, and dried in an oven at 50 ℃ for 6 h to obtain polysilane-shelled low-boiling-point aromatic microcapsules with a shell diameter of 5–10 μm.

[0021] IV. Preparation of Quick-Drying Resin Anticorrosive Paint for Pouring The quick-drying resin anti-corrosion paint includes the following raw materials in parts by weight: 80 parts epoxy resin, 3 parts sulfonic acid-based amphoteric oligomer, 1 part modified nano silica, 5 parts microcapsules, 5 parts polyisocyanate prepolymer, 1 part drying agent, 0.5 parts leveling agent, 0.1 parts defoamer, and 5 parts isopropanol.

[0022] The preparation steps are as follows: 100 g of epoxy resin is placed in a 500 mL stainless steel mixing vessel, stirred at 400 rpm, and heated to 30 ℃. 6.5 g of sulfonic acid-based amphoteric oligomer is added in batches, and stirred for 10 min until uniformly dispersed. 3 g of modified nano-silica is added, and sheared and stirred at 600 rpm for 15 min. Then, 10 g of microcapsules is slowly added, and gently mixed at 200 rpm for 5 min. 1.25 g of leveling agent, 0.55 g of defoamer, and 12.5 g of isopropanol are added sequentially, and stirred at 400 rpm for 10 min until the system is clear and homogeneous, obtaining component A. In a separate 250 mL container, 12.5 g of polyisocyanate prepolymer and 2 g of drying agent are added, and stirred at 300 rpm for 5 min at room temperature, obtaining component B. Pour component A into a 1 L mixing tank and stir at 350 rpm. Slowly add component B and maintain stirring for 10 min. Then switch to vacuum degassing mode and maintain at 0.08 MPa for 5 min to remove air bubbles from the system, thus obtaining a quick-drying resin anti-corrosion paint for potting.

[0023] Example 2 The preparation of modified nano-silica, sulfonic acid-based amphoteric oligomers, and microcapsules is the same as in Example 1.

[0024] The preparation method of quick-drying resin anti-corrosion paint for potting is as follows: The quick-drying resin anti-corrosion paint for potting comprises the following raw materials in parts by weight: 120 parts epoxy resin, 10 parts sulfonic acid-based amphoteric oligomer, 5 parts modified nano silica, 15 parts microcapsules, 20 parts polyisocyanate prepolymer, 3 parts drying agent, 2 parts leveling agent, 1 part defoamer, and 20 parts isopropanol.

[0025] The preparation steps for the quick-drying resin anti-corrosion paint are the same as in Example 1.

[0026] Example 3 The preparation of modified nano-silica, sulfonic acid-based amphoteric oligomers, and microcapsules is the same as in Example 1.

[0027] The preparation method of quick-drying resin anti-corrosion paint for potting is as follows: The quick-drying resin anti-corrosion paint for potting comprises the following raw materials in parts by weight: 100 parts epoxy resin, 6.5 parts sulfonic acid-based amphoteric oligomer, 3 parts modified nano silica, 10 parts microcapsules, 12.5 parts polyisocyanate prepolymer, 2 parts drying agent, 1.25 parts leveling agent, 0.55 parts defoamer, and 12.5 parts isopropanol.

[0028] The preparation steps for the quick-drying resin anti-corrosion paint are the same as in Example 1.

[0029] Comparative Example 1 The preparation of modified nano-silica and sulfonic acid-based amphoteric oligomers is the same as in Example 1.

[0030] The preparation method of quick-drying resin anti-corrosion paint for potting is as follows: The quick-drying resin anti-corrosion paint for potting comprises the following raw materials in parts by weight: 100 parts epoxy resin, 6.5 parts sulfonic acid-based amphoteric oligomer, 3 parts modified nano silica, 12.5 parts polyisocyanate prepolymer, 2 parts drying agent, 1.25 parts leveling agent, 0.55 parts defoamer, and 12.5 parts isopropanol.

[0031] The preparation steps for the quick-drying resin anti-corrosion paint are the same as in Example 1.

[0032] Comparative Example 2 The preparation of the sulfonic acid-based amphoteric oligomers and microcapsules was the same as in Example 1.

[0033] The preparation method of quick-drying resin anti-corrosion paint for potting is as follows: The quick-drying resin anti-corrosion paint for potting comprises the following raw materials in parts by weight: 100 parts epoxy resin, 6.5 parts sulfonic acid-based amphoteric oligomer, 3 parts unmodified nano silica, 10 parts microcapsules, 12.5 parts polyisocyanate prepolymer, 2 parts drying agent, 1.25 parts leveling agent, 0.55 parts defoamer, and 12.5 parts isopropanol.

[0034] The preparation steps for the quick-drying resin anti-corrosion paint are the same as in Example 1.

[0035] Performance testing 1. Surface drying / actual drying time test The surface of the metal plate was sanded, cleaned, and coated with a 0.5 mm thick anti-corrosion paint layer. It was then placed in a laboratory environment at 23 ± 2 °C and 50 ± 5% relative humidity. A timer was started, and the surface drying time (when the surface was no longer sticky) was recorded every 5 minutes by lightly touching the coating surface with a finger. This time was continued until no visible deformation or chalking of the paint film was observed after lightly tapping the surface with a wooden stick; this was recorded as the actual drying time. Three parallel samples were prepared for each type of specimen, and the average value was taken. The results are shown in Table 1 below.

[0036] Table 1. Duration of Surface Work / Actual Work ; As shown in Table 1, the embodiments of the present invention exhibit significant advantages over the comparative samples in terms of surface drying and complete drying time: Example 3 requires only 8 minutes for surface drying and 16 hours for complete drying, while Comparative Examples 1 and 2 require 45 minutes / 72 hours and 30 minutes / 36 hours, respectively. This performance improvement is mainly due to the formation of interconnected channels within the thick coating of the anti-corrosion paint, which accelerates solvent evaporation and crosslinking agent penetration. Simultaneously, the covalent grafting of the highly polar self-assembled interface layer with the substrate not only enhances the interfacial reaction kinetics but also promotes the synchronous progress of the curing reaction, thereby achieving rapid curing and uniform film formation of thick anti-corrosion paint at room temperature, effectively avoiding sagging and internal curing lag problems.

[0037] 2. Adhesion test After grinding, degreasing, and cleaning the surface of the metal sample plate, a 0.5 mm thick anti-corrosion paint was applied and cured at room temperature for 24 hours. After curing, a 20 mm diameter aluminum drawing disc and epoxy adhesive were used to attach the drawing disc at 23 ± 2 °C and 50 ± 5% relative humidity, and the adhesive was cured for 24 hours. The sample was then clamped in a drawing apparatus, and the preload was increased from 1.0 MPa / min to 0.2 MPa. After holding this preload for 30 seconds, the sample was stretched at a constant rate of 0.1 MPa / s until the drawing disc separated from the coating. The maximum tensile force was recorded and converted into adhesion force. Three parallel samples were tested for each formulation, and the average value was taken. The results are shown in Table 2 below.

[0038] Table 2 Adhesion Test Results ; As shown in Table 2, the average tensile strength of the anti-corrosion paint in Example 3 of this invention reached 2145 N, corresponding to an adhesion strength of 6.81 MPa, which is significantly higher than the 2.96 MPa and 3.97 MPa of Comparative Examples 1 and 2, respectively. This difference is mainly attributed to the strong covalent bonds formed between the monolayer constructed by the sulfonic acid amphoteric oligomer on the metal surface and the epoxy and isocyanate groups, which significantly enhances the interfacial bonding force, making pull-out failure more likely to occur inside the coating rather than at the substrate interface. Modified nano-silica improves the mechanical interlocking effect of the resin system through surface coupling reaction, providing additional physical reinforcement to the anti-corrosion paint coating; the microchannels ensure uniform curing and consistent internal crosslinking density of the anti-corrosion paint coating, avoiding concentration stratification or the formation of weak interfacial regions, thereby improving the overall bonding strength of the anti-corrosion paint coating.

[0039] 3. Salt spray corrosion resistance test The coated and dried metal samples (coating thickness approximately 0.5 mm) were arranged in a neutral salt spray test chamber using a tripod. The test conditions were 35 ± 2 °C, 5% (NaCl) saturated salt spray, and pH 6.5–7.2. After turning on the salt spray generator, the corrosion condition of the sample surface was checked every 24 hours, and the location and area of ​​blistering, peeling, and rust spots were recorded. The test duration was set at 1000 hours, and the absence of blistering, peeling, and rust spots on the coating surface was considered the pass standard. Three parallel samples were tested for each formulation, and the worst result was taken as the final result. The results are shown in Table 3 below.

[0040] Table 3 Salt spray corrosion resistance test results ; As shown in Table 3, after 1000 hours of neutral salt spray testing, the anti-corrosion paint coating of this embodiment maintained its surface integrity throughout, without blistering, peeling, or rust spots, while the comparative sample showed obvious corrosion damage within a shorter time. Because the microcapsules encapsulate low-boiling-point aromatic hydrocarbons in a polysilane shell, the microcapsules rupture after application, creating through-channels that accelerate the evaporation of the internal solvent and the penetration of the isocyanate crosslinking agent. This allows the epoxy resin to fully cure and form a dense network, avoiding micropores and cracks caused by uneven curing. Furthermore, the sulfonic acid-based amphoteric oligomers self-assemble into a monolayer on the metal surface and, through covalent grafting of epoxy groups with the MDI polyisocyanate prepolymer, construct chemical anchors with the substrate. This enables the high-adhesion interface to effectively resist mechanical stripping and chemical erosion in salt spray. The modified nano-silica dispersed in the resin matrix provides nanoscale reinforcement and filling for the system. Its surface silane coupling agent not only improves the interfacial adhesion between the particles and the resin but also optimizes leveling and defoaming properties, making the coating's microstructure more compact. The synergistic effect between these raw materials endows the quick-drying resin anti-corrosion paint of this invention with long-lasting protective capabilities in salt spray environments.

[0041] 4. Chemical media tolerance test After grinding, cleaning, and curing for 24 hours, the coated samples (approximately 0.5 mm thick) were immersed in four different media: 5% HCl solution, 5% NaOH solution, diesel fuel, and xylene solvent, and placed in a 25°C constant temperature oven. Every 24 hours, the samples were removed, rinsed with water, and dried. They were weighed and inspected for blistering, cracking, or peeling. They were then re-immersed in the original media. After 240 hours of continuous immersion, the percentage change in mass and any visible coating damage were recorded. Three parallel samples were prepared for each formulation, and the average value was taken. The results are shown in Table 4 below.

[0042] Table 4 Results of Chemical Media Tolerance Test ; As shown in Table 4, during 240 hours of immersion in the four media, the coating mass change rates of Examples 1–3 were only 0.5%, 0.4%, and 0.3%, respectively, with no blistering or cracking. In contrast, the mass change rates of Comparative Examples 1 and 2 were as high as 3.2% and 1.8%, respectively, with obvious blistering and cracking. In this invention, the transport microchannels formed after the microcapsules rupture not only accelerate the in-depth reaction of the crosslinking agent and reduce the defects of the uncured inner layer, but also eliminate the penetration path of typical media through the uniform filling of modified nano-SiO2. In addition, the chemical anchor points constructed by the covalent grafting of sulfonic acid amphoteric oligomers and resin significantly improve the interfacial bonding force, enabling the anti-corrosion coating and the metal substrate to synergistically resist the mechanical tearing of chemical solvents.

[0043] 5. Mechanical performance testing The anti-corrosion paint coating sample (0.5 mm thick) cured for 24 hours was cut from the substrate and the edges were sanded smooth. Hardness was tested using a pencil hardness tester; a 6H–6B pencil was used to scribble at a 45° angle, and the sample's hardness grade was determined by the absence of a mark at the finest point of the scribing. Abrasion resistance was tested using a Taber abrasive mill, with a CS-10 grinding wheel and a 500 g load, undergoing 1000 revolutions of abrasion. Abrasion resistance was assessed by the sample's mass loss (mg). Impact testing involved increasing the impact force from 0.5 J until the coating cracked or delaminated, recording the maximum energy value (J). Bending testing involved bending the coating coaxially with the metal substrate to a radius of 3 mm and holding for 1 minute; no cracks or peeling were considered acceptable. The average value of three parallel samples was used for each test, and the results are shown in Table 5 below.

[0044] Table 5 Mechanical Performance Test Results ; As shown in Table 5, the mechanical properties of the anti-corrosion paint coating of the present invention are significantly superior to those of the comparative sample in terms of hardness, abrasion resistance, impact strength, and bending performance. Example 3 achieved a pencil hardness of 4H, while the comparative sample only reached 2H, indicating that the chemical coupling between the modified nano-silica and the resin improved the surface hardness of the coating. In the Taber abrasion test, Example 3 experienced a mass loss of only 8 mg, while the comparative sample lost 25 mg, demonstrating that the microchannel network and nanofiller synergistically formed a dense cross-linked structure, effectively dispersing and withstanding wear energy. In the impact test, Example 3 withstood a maximum energy of 14 J, nearly 75% higher than the 8 J of the comparative sample, further demonstrating the enhanced interfacial chemical anchoring effect of the interfacial covalent grafting. In the bending test, no cracks were generated in any of the examples, while cracks appeared in the comparative sample, indicating that the sulfonic acid-based amphoteric oligomer self-assembled interfacial layer formed a flexible and high-strength transition zone between the substrate and the anti-corrosion paint coating, maintaining integrity under small-radius bending.

[0045] 6. Performance stability and aging test The anti-corrosion paint coating samples cured for 24 hours were placed in a damp heat / freeze-thaw cycle test chamber for cyclic testing. Each cycle consisted of 8 hours of 85 °C / 85% RH damp heat conditions and 4 hours of 20 °C freeze-thaw conditions, for a total of 10 cycles. After the cycles, adhesion was measured, and surface integrity was assessed using a 3-level cross-cut test. Subsequently, another set of samples was placed in a QUV aging chamber (UV-A phosphorescent lamp, 8 hours of UV irradiation @60 °C + 4 hours of condensation @50 °C) for 1000 hours of exposure, and color difference ΔE, pencil hardness change, and pull-out adhesion degradation were recorded periodically. All tests used three parallel samples and the average value was taken. The results are shown in Table 6 below.

[0046] Table 6 Performance stability and aging test results ; As shown in Table 6, after 10 damp heat / freeze-thaw cycles and 1000 h of UV aging tests, Examples 1–3 still maintained an adhesion retention rate of 92%–95%, with no scratches or peeling on the surface, a color difference ΔE of only 0.7–0.9, and no change in pencil hardness. In contrast, Comparative Examples 1 and 2 retained only 68% and 75% of their adhesion, respectively, exhibiting peeling at levels 2 and 1, with color differences increasing to 3.6 and 2.2, and hardness decreasing from 3H / 4H to 2H. This demonstrates that the microchannel network ensures the coating maintains good cross-linking density under extreme damp heat and low temperature alternating conditions, preventing inner layer warping and delamination; the highly polar sulfonic acid-based amphoteric oligomer interfacial monolayer is covalently grafted with the resin matrix, forming a robust chemical anchor point, significantly improving interfacial durability and stability; the modified nano-silica dispersed in the resin not only enhances the mechanical toughness of the coating but also strengthens the physical barrier function under UV aging, effectively blocking photo-oxidative degradation.

[0047] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0048] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A method for preparing a quick-drying resin anti-corrosion paint for application, characterized in that, The following steps are involved: S1. Disperse nano-silica in a solvent, add alkoxysilane coupling agent and mix, stir and react, then wash and dry to obtain surface-modified nano-silica; S2. Mix epoxy resin, sulfonic acid amphoteric oligomer, and modified nano-SiO2, add microcapsules and mix, then add leveling agent, defoamer and isopropanol, and stir until the system is clear and homogeneous to obtain component A. S3. Mix the polyisocyanate prepolymer with the drying agent and stir until homogeneous to obtain component B; S4. Pour component A obtained in step S2 into a mixing tank, add component B obtained in step S3, and simultaneously degas until the paint fluid is uniform, which is the quick-drying resin anti-corrosion paint for potting.

2. The method for preparing the quick-drying resin anti-corrosion paint according to claim 1, characterized in that, The quick-drying resin anti-corrosion paint comprises the following raw materials in parts by weight: 80-120 parts epoxy resin, 3-10 parts sulfonic acid amphoteric oligomer, 1-5 parts modified nano silica, 5-15 parts microcapsules, 5-20 parts polyisocyanate prepolymer, 1-3 parts drying agent, 0.5-2 parts leveling agent, 0.1-1 parts defoamer, and 5-20 parts isopropanol.

3. The method for preparing the quick-drying resin anti-corrosion paint according to claim 1, characterized in that, In step S4, the mixing temperature is 20–30 °C, and the stirring speed is 300–600 rpm.

4. The method for preparing the quick-drying resin anti-corrosion paint according to claim 1, characterized in that, The preparation method of the modified nano-silica specifically includes the following steps: S101. Disperse nano-silica powder in anhydrous ethanol and then use ultrasound to make it uniformly dispersed. S102. Add alkoxysilane coupling agent solution to the dispersion and stir continuously to allow the coupling agent molecules to adsorb and react with the hydroxyl groups on the silicon surface; after the reaction is complete, separate the modified particles by centrifugation or filtration and wash them several times with anhydrous ethanol to remove unreacted coupling agent. S103. The modified nano-silica is dried to obtain surface-modified nano-silica in powder form.

5. The method for preparing the quick-drying resin anti-corrosion paint according to claim 1, characterized in that, The preparation method of the sulfonic acid-based amphoteric oligomer specifically includes the following steps: S201. Dissolve toluene sulfonate monomer, ethylene oxide and propylene glycol monomer in anhydrous toluene, add a free radical initiator and carry out free radical polymerization; S202. After the polymerization reaches the designed conversion rate, triethanolamine is added to the reaction system, and the solvent and unreacted substances are removed by distillation or membrane separation. S203. The neutralized crude product was subjected to multiple solvent washings and vacuum drying to obtain sulfonic acid-based amphoteric oligomers with an average molecular weight of 1000-1500 Da.

6. The method for preparing the quick-drying resin anti-corrosion paint according to claim 1, characterized in that, The preparation method of the microcapsules specifically includes the following steps: S301. Dissolve low-boiling-point aromatic core material and alkoxysilane precursor in an organic phase and disperse them in an aqueous phase containing a stable emulsifier to form a water-in-oil emulsion; S302. A catalyst is added to the emulsion system to promote the condensation polymerization of silane precursors at the oil-water interface to generate a polysilane shell; S303. After the reaction is complete, the aqueous phase is removed by centrifugation or membrane separation, and the microcapsules are washed with water or anhydrous ethanol and dried to obtain polysilane-shelled low-boiling-point aromatic microcapsules with a shell diameter of 5-10 μm.

7. The method for preparing the quick-drying resin anti-corrosion paint according to claim 1, characterized in that, The surface drying time of the anti-corrosion paint is 10-15 minutes at 25°C and 50% relative humidity.

8. The method for preparing the quick-drying resin anti-corrosion paint according to claim 1, characterized in that, The salt spray resistance of the coating after the anti-corrosion paint has dried is not less than 1000 h.

9. The method for preparing the quick-drying resin anti-corrosion paint according to claim 1, characterized in that, The drying agent is N,N-dimethylethanolamine, the leveling agent is a polyacrylate leveling agent, and the defoamer is an organosilicone defoamer.

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