Self-repairing type mugwort microcrystalline grade heavy anti-corrosion coating and preparation method thereof

Abstract

The invention relates to the technical field of functional coatings, in particular to a self-repairing type mugwort microcrystalline grade heavy anti-corrosion coating and a preparation method thereof. 40 to 60 parts of a waxy matrix; 3-8 parts of a microcapsule repairing agent; 15 to 25 parts of a nano composite reinforcing system, wherein the nano composite reinforcing system comprises 8 to 12 parts of micron-sized talcum powder and 8 to 12 parts of nano-sized silicon carbide; 15 to 20 parts of a functional filler; according to the coating, the self-repairing capacity of a coating is improved, microcracks generated in the using process of the coating can be effectively repaired, corrosion media are prevented from permeating, stripping and damage of the coating are delayed, the protection performance of the coating is improved, and the service life of the coating is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of functional coatings, and in particular to a self-repairing microcrystalline heavy-duty anti-corrosion coating and a preparation method thereof. Background Art

[0002] Anti-corrosion coatings, as an important material for protecting metal surfaces, are widely used in industrial production and daily life. However, existing anti-corrosion coatings have several drawbacks, such as poor self-healing capabilities, low wear resistance, and low impact resistance. During use, coatings are inevitably affected by various external factors, such as physical shock, temperature fluctuations, and aging. These factors can easily form microcracks within the coating, leading to the penetration of corrosive media, accelerated flaking and damage, and reduced coating protection and service life.

[0003] Furthermore, the wear and impact resistance of existing anti-corrosion coatings needs to be improved. In harsh environments, such as those found in offshore engineering facilities, where high temperatures, humidity, salt levels, and strong radiation are present, microcracks can easily form on the coating surface, compromising its corrosion resistance and durability. Furthermore, coatings are also susceptible to wear and impact during use, leading to a degradation of coating performance.

[0004] Therefore, developing an environmentally friendly anti-corrosion coating with self-healing properties, excellent wear resistance, and impact resistance is crucial for extending coating life, improving protective performance, and reducing maintenance costs. Imparting self-healing, wear resistance, and impact resistance to coatings through the design of microcapsule repair and nanocomposite systems while simultaneously meeting environmental requirements is a pressing technical challenge in the field of anti-corrosion coatings. Summary of the Invention

[0005] The purpose of the present invention is to provide a self-repairing microcrystalline heavy-duty anti-corrosion coating and a preparation method thereof in response to the deficiencies of the prior art.

[0006] In order to solve the above technical problems, the following technical solutions are adopted:

[0007] A self-repairing Amy microcrystalline heavy-duty anti-corrosion coating comprising the following components in parts by weight:

[0008] - Waxy matrix: composed of component A and component B in a mass ratio of 4: (1-1.1), wherein:

[0009] Component A contains: 3-5 parts of benzyl alcohol, 20-30 parts of bisphenol A epoxy resin, 1-2 parts of organic bentonite, 0.3-0.5 parts of dispersant, 0.1-0.2 parts of defoaming agent, 40-65 parts of barium sulfate, and 0.5-1.5 parts of modified polyamide wax;

[0010] Component B contains: 0.5-1 parts of isooctyl alcohol, 15-27 parts of m-xylylenediamine, 1-2 parts of organic bentonite, 0.3-0.5 parts of dispersant, 0.1-0.3 parts of defoamer, 10-15 parts of polytetrafluoroethylene wax powder, and 40-60 parts of barium sulfate;

[0011] - Microcapsule repair agent: 3-8 parts; the wall material of the microcapsule repair agent includes polyurethane-urea-formaldehyde resin, and the core material includes linseed oil, nano-cerium oxide-clay mixture and benzotriazole;

[0012] -Nanocomposite reinforcement system: 15-25 parts, wherein the nanocomposite reinforcement system comprises micron-sized talc powder and nano-sized silicon carbide;

[0013] - Functional filler: 15-20 parts.

[0014] A further improvement based on the above technical solution is that the preparation process of component A of the waxy matrix includes:

[0015] Step 101: Add benzyl alcohol and bisphenol A epoxy resin into a reaction kettle and mix and disperse for 10 minutes at a rotation speed of 400-500 rpm;

[0016] Step 102: adding organic bentonite, rotating at 600 rpm, and dispersing for 15 minutes;

[0017] Step 103: Add dispersant and defoamer to the kettle in sequence; stir for 5 minutes at a constant speed;

[0018] Step 104: Finally, add barium sulfate and modified polyamide wax in sequence, increase the rotation speed to 800 rpm, and stir and disperse for 30 minutes to obtain component A.

[0019] A further improvement based on the above technical solution is that the preparation process of component B of the waxy matrix includes:

[0020] Step 201: add isooctyl alcohol and m-xylenediamine to a reaction kettle and mix and disperse for 10 minutes at a rotation speed of 400-500 rpm;

[0021] Step 202: adding organic bentonite, rotating at 600 rpm, and dispersing for 15 minutes;

[0022] Step 203: add dispersant and defoamer to the kettle in sequence; stir for 5 minutes at a constant speed;

[0023] Step 204: Add polytetrafluoroethylene wax powder to the kettle, increase the speed to 700-800 rpm, and stir and disperse for 20 minutes;

[0024] Step 205: Finally, add barium sulfate and talc powder in sequence, increase the rotation speed to 800-1000 rpm, and stir and disperse for 20 minutes to obtain component B.

[0025] A further improvement based on the above technical solution is that the particle size distribution of the microcapsule repair agent is D90≤50μm, and the wall material thickness is 0.5-2μm.

[0026] A further improvement based on the technical solution is that the nanocomposite reinforcement system also includes dopamine-modified glass fibers, the interfacial shear strength of the dopamine-modified glass fibers is ≥45 MPa, and the dopamine-modified glass fibers form a three-dimensional reinforcement network in the wax matrix.

[0027] A further improvement based on the above technical solution is that the functional filler is graphene, silicon carbide or a composite of graphene and silicon carbide.

[0028] The present invention proposes another technical solution: a method for preparing a self-repairing microcrystalline heavy-duty anti-corrosion coating, comprising the following steps:

[0029] S1. Preparation of microcapsule repair agent:

[0030] First, linseed oil, nano-cerium oxide and clay are mixed in a mass ratio of 1: (1-2): 1, and a homogeneous liquid is formed by high-pressure homogenization or microfluidics technology;

[0031] Then, polyurethane-urea-formaldehyde resin wall material and benzotriazole are added, with the mass fraction of benzotriazole being 5-8%, and microcapsules are formed through interfacial polymerization;

[0032] Finally, the microcapsules are mixed with an organic fluorine-silicon modified resin and a platinum-based catalyst in a mass ratio of (8-10):(4-5):1, and nano-SiO2 is added. The nano-SiO2 has a particle size of 20-50 nm and a mass fraction of 3-4%. The prepared microcapsule repair agent is sealed and stored.

[0033] S2. Construction of nanocomposite system:

[0034] First, a gradient filling method is used to mix micron-sized talc powder and nano-sized silicon carbide in a mass ratio of 1:1;

[0035] Then, the glass fiber is impregnated with dopamine solution to enhance the shear strength of the resin matrix interface to ≥45MPa;

[0036] Finally, the modified glass fiber is cut into short fibers, mixed with the wax matrix at a mass ratio of 1:(8-10), and 3-8 parts of the microcapsule repair agent prepared in step 1 are added, and stirred at a low speed of 500-600 rpm for 15 minutes until the system is evenly dispersed to form a nanocomposite reinforcement slurry containing the repair agent;

[0037] S3. Coating and curing:

[0038] Mix the waxy base component A and component B at a ratio of 4: (1-1.1), and cross-link with the water-based polymer and ionic modified resin to form a base layer;

[0039] Mix modified polyamide wax and polytetrafluoroethylene wax powder in a ratio of 4: (1-1.1), add 20-30 parts of polyethylene wax powder and 5-8 parts of nanoclay to form an intermediate layer;

[0040] The nanocomposite reinforcement slurry prepared in step S2 is impregnated with glass fiber fabric and then laid to form a reinforcement layer;

[0041] The graphene / silicon carbide composite filler is mixed with a waxy matrix and then coated to form a surface layer;

[0042] Finally, the film was cured at 90°C for 30 minutes with a heating rate of ≤5°C / min.

[0043] A further improvement based on the above technical solution is that the interfacial polymerization reaction conditions of the microcapsule repair agent are: temperature 40-60° C., pH value 2-4, and reaction time 2-4 hours.

[0044] A further improvement based on the above technical solution is that the impregnation time of the dopamine-modified glass fiber in the nanocomposite system is 1-2 hours, and the length of the modified fiber is 0.5-2 mm.

[0045] A further improvement based on the above technical solution is that the polyethylene wax powder content of the middle layer in the layered coating is 20-30%, and the nano clay content is 5-8%.

[0046] The above technical solution has the following beneficial effects:

[0047] The self-repairing Amy microcrystalline heavy-duty anti-corrosion coating of the present invention adopts a solvent-free system, does not contain organic volatile solvents, has excellent environmental performance, and can effectively avoid the environmental pollution problems existing in traditional solvent-based coatings.

[0048] The waxy base adopts a two-component system of A and B, which can cure quickly, shorten the construction period and improve construction efficiency.

[0049] Microcapsule repair agent: uses polyurethane-urea-formaldehyde resin wall material to encapsulate linseed oil, nano-cerium oxide / clay and benzotriazole, and releases through dual triggering of mechanical rupture and environmental response (pH sensitivity).

[0050] Nanocomposite system: gradient filling of micron talc and nano silicon carbide, combined with dopamine-modified glass fiber reinforced interface;

[0051] The specific effects are as follows:

[0052] 1. It improves the self-repairing ability of the coating, can effectively repair the micro-cracks generated in the coating during use, prevent the penetration of corrosive media, delay the peeling and damage of the coating, and improve the protective performance and service life of the coating.

[0053] 2. The wear resistance and impact resistance of the coating are significantly enhanced. Even in harsh environments, microcracks are not easily generated, ensuring the anti-corrosion effect and durability of the coating. At the same time, the coating can also resist the influence of wear and impact during use, extending the service life of the coating.

[0054] 3. By optimizing the preparation process and wall material formula of the microcapsule repair agent, the storage stability and long-term repair effect of the microcapsules are significantly improved, ensuring that the repair agent can play an effective role in the long term.

[0055] 4. The gradient filling technology and multi-scale nano-composite system are used to balance the mechanical properties and construction leveling properties of the coating, giving the coating excellent comprehensive performance.

[0056] 5. Through functional layered design and curing process control, the rational construction of the coating structure is achieved, ensuring the synergistic performance of each layer of the coating.

[0057] 6. It meets environmental protection requirements, with the volatile organic compound (VOC) content lower than 50g / L, in line with the green environmental protection concept. DETAILED DESCRIPTION

[0058] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is described in detail below by way of examples as a further illustration of the present invention. However, it should be understood that the specific embodiments described herein are merely for the purpose of explaining the present invention and are not intended to limit the scope of the present invention. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessary confusion of the concept of the present invention.

[0059] A self-repairing Amy microcrystalline heavy-duty anti-corrosion coating comprising the following components in parts by weight:

[0060] - Waxy matrix: composed of component A and component B in a mass ratio of 4: (1-1.1), wherein:

[0061] Component A contains: 3-5 parts of benzyl alcohol, 20-30 parts of bisphenol A epoxy resin, 1-2 parts of organic bentonite, 0.3-0.5 parts of dispersant, 0.1-0.2 parts of defoaming agent, 40-65 parts of barium sulfate, and 0.5-1.5 parts of modified polyamide wax;

[0062] Component B comprises: 0.5-1 parts of isooctyl alcohol, 15-27 parts of m-xylenediamine, 1-2 parts of organic bentonite, 0.3-0.5 parts of dispersant, 0.1-0.3 parts of defoaming agent, 10-15 parts of polytetrafluoroethylene wax powder, and 40-60 parts of barium sulfate.

[0063] - Microcapsule repair agent: 3-8 parts; the wall material of the microcapsule repair agent includes polyurethane-urea-formaldehyde resin, and the core material includes linseed oil, nano-cerium oxide-clay mixture and benzotriazole.

[0064] -Nano-composite reinforcement system: 15-25 parts, wherein the nano-composite reinforcement system comprises micron-sized talc powder and nano-sized silicon carbide.

[0065] - Functional filler: 15-20 parts.

[0066] Specifically, the material composition and model of component A and component B are shown in Table 1:

[0067] Table 1

[0068]

[0069]

[0070] Specifically, the preparation process of component A and component B of the waxy matrix includes:

[0071] Step 1: Prepare component A, which includes:

[0072] Step 101: Add benzyl alcohol and bisphenol A epoxy resin into a reaction kettle and mix and disperse for 10 minutes at a rotation speed of 400-500 rpm;

[0073] Step 102: adding organic bentonite, rotating at 600 rpm, and dispersing for 15 minutes;

[0074] Step 103: Add dispersant and defoamer to the kettle in sequence; stir for 5 minutes at a constant speed;

[0075] Step 104: Finally, add barium sulfate and modified polyamide wax in sequence, increase the rotation speed to 800 rpm, and stir and disperse for 30 minutes to obtain component A.

[0076] Step 2: preparing component B, said step 2 comprising:

[0077] Step 201: add isooctyl alcohol and m-xylenediamine to a reaction kettle and mix and disperse for 10 minutes at a rotation speed of 400-500 rpm;

[0078] Step 202: adding organic bentonite, rotating at 600 rpm, and dispersing for 15 minutes;

[0079] Step 203: add dispersant and defoamer to the kettle in sequence; stir for 5 minutes at a constant speed;

[0080] Step 204: Add polytetrafluoroethylene wax powder to the kettle, increase the speed to 700-800 rpm, and stir and disperse for 20 minutes;

[0081] Step 205: Finally, add barium sulfate and talc powder in sequence, increase the rotation speed to 800-1000 rpm, and stir and disperse for 20 minutes to obtain component B.

[0082] Specifically, the particle size distribution of the microcapsule repair agent is D90≤50 μm, and the wall material thickness is 0.5-2 μm.

[0083] Specifically, the nanocomposite reinforcement system further includes dopamine-modified glass fibers, which have an interfacial shear strength of ≥45 MPa and form a three-dimensional reinforcement network within a wax matrix. The three-dimensional reinforcement network has a fiber spacing of 5-20 μm and a porosity of 30-45%.

[0084] Specifically, the functional filler is graphene, silicon carbide or a composite of graphene and silicon carbide. Preferably, the ratio of the graphene to silicon carbide composite is 1:1.

[0085] This embodiment proposes another technical solution: a method for preparing a self-repairing Amy microcrystalline heavy-duty anti-corrosion coating, comprising the following steps:

[0086] S1. Preparation of microcapsule repair agent:

[0087] First, linseed oil, nano-cerium oxide and clay are mixed in a mass ratio of 1: (1-2): 1, and a homogeneous liquid is formed by high-pressure homogenization or microfluidics technology;

[0088] Then, polyurethane-urea-formaldehyde resin wall material and benzotriazole are added, with the mass fraction of benzotriazole being 5-8%, and microcapsules are formed through interfacial polymerization; the interfacial polymerization reaction conditions of the microcapsule repair agent are: temperature 40-60°C, pH value 2-4, and reaction time 2-4 hours.

[0089] Finally, the microcapsules are mixed with an organic fluorine-silicon modified resin and a platinum-based catalyst in a mass ratio of (8-10):(4-5):1, and nano-SiO2 is added. The nano-SiO2 has a particle size of 20-50 nm and a mass fraction of 3-4%. The prepared microcapsule repair agent is sealed and stored.

[0090] S2. Construction of nanocomposite system:

[0091] First, a gradient filling method is used to mix micron-sized talc powder and nano-sized silicon carbide in a mass ratio of 1:1; the gradient filling method is: adding micron-sized talc powder to nano-sized silicon carbide at a speed of 200-300 rpm in 3 times, with an interval of 5 minutes each time.

[0092] Then, the glass fiber is impregnated with a dopamine solution to enhance the shear strength of the resin matrix interface to ≥45 MPa; the impregnation time of the dopamine-modified glass fiber in the nanocomposite system is 1-2 hours, and the fiber length after modification is 0.5-2 mm.

[0093] Finally, the modified glass fiber is cut into short fibers, mixed with the wax matrix at a mass ratio of 1:(8-10), and 3-8 parts of the microcapsule repair agent prepared in step 1 are added, and stirred at a low speed of 500-600 rpm for 15 minutes until the system is evenly dispersed to form a nanocomposite reinforcement slurry containing the repair agent;

[0094] S3. Coating and curing:

[0095] Mix the waxy base component A and component B at a ratio of 4: (1-1.1), and cross-link with the water-based polymer and ionic modified resin to form a base layer;

[0096] Modified polyamide wax and polytetrafluoroethylene wax powder are mixed in a ratio of 4: (1-1.1), and 20-30 parts of polyethylene wax powder and 5-8 parts of nanoclay are added to form an intermediate layer; in the layered coating, the polyethylene wax powder content of the intermediate layer is 20-30%, and the nanoclay content is 5-8%.

[0097] The nanocomposite reinforcement slurry prepared in step S2 is impregnated with glass fiber fabric and then laid to form a reinforcement layer;

[0098] The graphene / silicon carbide composite filler is mixed with a waxy matrix and then coated to form a surface layer;

[0099] Finally, the film was cured at 90°C for 30 minutes with a heating rate of ≤5°C / min.

[0100] Amy microcrystalline grade refers to the microcrystalline structure formed after the coating is cured, with a particle size distribution within the range of 10-100nm and a crystal defect density of ≤5×10 -4 cm -2 microstructural grade.

[0101] Example 1

[0102] 1. Component ratio (parts by mass)

[0103] Waxy base:

[0104] Component A: 3 parts of benzyl alcohol, 20 parts of bisphenol A epoxy resin (FF1338), 1 part of organic bentonite (BP-184), 0.3 parts of dispersant (410), 0.1 parts of defoamer (208), 40 parts of barium sulfate (2500 mesh), and 0.5 parts of modified polyamide wax;

[0105] Component B: 0.5 parts of isooctyl alcohol, 15 parts of m-phenylenediamine (EP32-1G), 1 part of organic bentonite (BP-184), 0.3 parts of dispersant (410), 0.1 parts of defoamer (208), 10 parts of polytetrafluoroethylene wax powder (HD3350), 40 parts of barium sulfate (2500 mesh);

[0106] The A / B components were mixed in a mass ratio of 4:1.

[0107] Microcapsule repair agent: 5 parts, wall material is polyurethane-urea-formaldehyde resin (wall thickness 1 μm), core material is linseed oil: nano-cerium oxide-clay mixture: benzotriazole (mass ratio 1:1:0.06), particle size D90 = 30 μm.

[0108] Nanocomposite reinforcement system: 15 parts, including 8 parts of micron-grade talc powder, 7 parts of nano-grade silicon carbide, and 2 parts of dopamine-modified glass fiber (interface shear strength 45 MPa, fiber length 0.5 mm).

[0109] Functional filler: a composite of 10 parts of graphene and 10 parts of silicon carbide.

[0110] 2. Preparation process

[0111] Microcapsule repair agent: linseed oil, nano-cerium oxide and clay are homogenized at 100 MPa high pressure for 30 minutes, interfacially polymerized at 40°C and pH = 2 for 2 hours, mixed with organic fluorine-silicon modified resin in a ratio of 8:4:1 and sealed for storage.

[0112] Nanocomposite system: micron talc powder and nano silicon carbide gradient filling, dopamine modified glass fiber (impregnated for 1 hour) and wax matrix were mixed at a ratio of 1:8 and stirred at 500 rpm for 15 minutes.

[0113] Coating and curing: Layered coating (bottom layer 50 μm, middle layer 80 μm, reinforcement layer 100 μm, surface layer 60 μm), heating to 90°C at 3°C / min and curing for 30 minutes.

[0114] 3. Performance Testing

[0115] Self-repair efficiency: The repair rate of 0.1mm microcracks is 92% in 24 hours and 98% in 48 hours (SEM observation).

[0116] Abrasion resistance: ASTM D4060 test (500g load) abrasion loss is 0.05g, which is 67% lower than that of traditional coatings.

[0117] VOC content: 45g / L.

[0118] Example 2

[0119] 1. Optimization of group allocation ratio

[0120] The microcapsule repair agent was increased to 8 parts, and the ratio of nano-cerium oxide-clay mixture in the core material was increased to 1:2;

[0121] Nanocomposite reinforcement system: 12 parts of micron talc powder, 12 parts of nano silicon carbide, 3 parts of dopamine modified fiber (interface shear strength 50 MPa, length 2 mm);

[0122] Functional filler: 20 parts of graphene / silicon carbide (1:1) composite.

[0123] 2. Key process adjustments

[0124] The microcapsule interfacial polymerization temperature was 60°C, pH = 4, and the reaction time was 4 hours;

[0125] The middle layer contains 30% polyethylene wax powder and 8% nanoclay;

[0126] The curing heating rate is 5°C / min.

[0127] 3. Performance improvement data

[0128] Self-repair efficiency: 95% repair rate in 12 hours, completely healed in 24 hours;

[0129] Wear resistance: Taber test (1000g load) abrasion loss 0.03g, impact strength 50kg·cm, no cracking.

[0130] VOC content: 38g / L, in line with GB18582-2020 Level 1 standard.

[0131] Example 3:

[0132] 1. Components and process characteristics

[0133] The amount of waxy matrix barium sulfate was reduced to 40 parts, and 1.5 parts of modified polyamide wax was added;

[0134] 3 parts of microcapsule repair agent (benzotriazole mass fraction 8%), prepared by microfluidic technology (flow rate 8 mL / min), particle size D90 = 20 μm;

[0135] The curing temperature is 80°C, the heating rate is 2°C / min, and the heat preservation time is 40 minutes.

[0136] 2. Balance between environmental protection and performance

[0137] VOC content 32g / L (GB18582-2020 Level 1 standard);

[0138] Self-repair efficiency: 88% repair rate within 24 hours;

[0139] Wear resistance: abrasion loss 0.06g, no powdering after QUV aging for 1000h.

[0140] Comparative Example: Effects of Dopamine-Deficient Modified Fibers

[0141] 1. Group distribution ratio

[0142] The dopamine-modified glass fiber in the nanocomposite reinforcement system was omitted, and the remaining parameters were the same as in Example 1.

[0143] 2. Performance degradation data

[0144] The interfacial shear strength dropped from 45 MPa to 28 MPa;

[0145] The self-repair efficiency was only 65% ​​in 24 hours, and the wear loss increased to 0.12g (an increase of 140%);

[0146] The salt spray test was conducted according to GB / T 1771-2019, using a 5% NaCl solution at 35°C ± 2°C for 1000 hours of continuous spraying.

[0147] Supplementary Notes on Implementation Methods

[0148] Parameter range verification: Examples 1-3 verified the effectiveness of the A / B component ratio (4:1-4:1.1), microcapsule dosage (3-8 parts) and nanocomposite system (15-25 parts). The high wear-resistant formula is suitable for marine engineering, and the low VOC formula is suitable for indoor scenes.

[0149] Standardization of test methods:

[0150] Self-repair efficiency: ImageJ analysis of the crack healing area of ​​SEM images, with an error of ±3%;

[0151] Abrasion resistance: ASTM D4060 standard, specimen curing for 7 days (23°C ± 2°C, 50% RH);

[0152] VOC content: GB / T23986-2009 test.

[0153] Mechanism of action:

[0154] Dopamine-modified fibers form a three-dimensional network, increasing the diffusion efficiency of the repair agent by 40%;

[0155] Nano-silicon carbide and microcapsules work synergistically to increase abrasive cutting resistance by 50%.

[0156] The above are only specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent substitutions, or modifications based on the present invention to solve substantially the same technical problems and achieve substantially the same technical effects are included within the scope of protection of the present invention.

Claims

1. A self-repairing Amy microcrystalline heavy-duty anti-corrosion coating, characterized by: Contains the following components by mass: - Waxy matrix: composed of component A and component B in a mass ratio of 4: (1-1.1), where: Component A contains: 3-5 parts of benzyl alcohol, 20-30 parts of bisphenol A epoxy resin, 1-2 parts of organic bentonite, 0.3-0.5 parts of dispersant, 0.1-0.2 parts of defoaming agent, 40-65 parts of barium sulfate, and 0.5-1.5 parts of modified polyamide wax; Component B contains: 0.5-1 parts of isooctyl alcohol, 15-27 parts of m-xylylenediamine, 1-2 parts of organic bentonite, 0.3-0.5 parts of dispersant, 0.1-0.3 parts of defoamer, 10-15 parts of polytetrafluoroethylene wax powder, and 40-60 parts of barium sulfate; - Microcapsule repair agent: 3-8 parts; the wall material of the microcapsule repair agent includes polyurethane-urea-formaldehyde resin, and the core material includes linseed oil, nano-cerium oxide-clay mixture and benzotriazole; -Nanocomposite reinforcement system: 15-25 parts, wherein the nanocomposite reinforcement system comprises micron-sized talc powder and nano-sized silicon carbide; - Functional filler: 15-20 parts.

2. The self-repairing microcrystalline heavy-duty anti-corrosion coating according to claim 1, characterized in that: The preparation process of component A of the waxy matrix includes: Step 101: Add benzyl alcohol and bisphenol A epoxy resin into a reaction kettle and mix and disperse for 10 minutes at a rotation speed of 400-500 rpm; Step 102: adding organic bentonite, rotating at 600 rpm, and dispersing for 15 minutes; Step 103: Add dispersant and defoamer to the kettle in sequence; stir for 5 minutes at a constant speed; Step 104: Finally, add barium sulfate and modified polyamide wax in sequence, increase the rotation speed to 800 rpm, and stir and disperse for 30 minutes to obtain component A.

3. The self-repairing microcrystalline heavy-duty anti-corrosion coating according to claim 1 is characterized by: The preparation process of component B of the waxy matrix includes: Step 201: add isooctyl alcohol and m-xylenediamine to a reaction kettle and mix and disperse for 10 minutes at a rotation speed of 400-500 rpm; Step 202: adding organic bentonite, rotating at 600 rpm, and dispersing for 15 minutes; Step 203: add dispersant and defoamer to the kettle in sequence; stir for 5 minutes at a constant speed; Step 204: Add polytetrafluoroethylene wax powder to the kettle, increase the speed to 700-800 rpm, and stir and disperse for 20 minutes; Step 205: Finally, add barium sulfate and talc powder in sequence, increase the rotation speed to 800-1000 rpm, and stir and disperse for 20 minutes to obtain component B.

4. The self-repairing microcrystalline heavy-duty anti-corrosion coating according to claim 1, characterized in that: The particle size distribution of the microcapsule repair agent is D90≤50 μm, and the wall material thickness is 0.5-2 μm.

5. The self-repairing microcrystalline heavy-duty anti-corrosion coating according to claim 1 is characterized by: The nanocomposite reinforcement system further comprises dopamine-modified glass fibers, the interfacial shear strength of the dopamine-modified glass fibers is greater than or equal to 45 MPa, and the dopamine-modified glass fibers form a three-dimensional reinforcement network in the wax matrix.

6. The self-repairing microcrystalline heavy-duty anti-corrosion coating according to claim 1, characterized in that: The functional filler is graphene, silicon carbide or a composite of the graphene and silicon carbide.

7. A method for preparing the self-repairing waxy heavy-duty anti-corrosion coating according to any one of claims 1 to 6, characterized by the following steps: S1. Preparation of microcapsule repair agent: First, linseed oil, nano-cerium oxide and clay are mixed in a mass ratio of 1: (1-2): 1, and a homogeneous liquid is formed by high-pressure homogenization or microfluidics technology; Then, polyurethane-urea-formaldehyde resin wall material and benzotriazole are added, with the mass fraction of benzotriazole being 5-8%, and microcapsules are formed through interfacial polymerization; Finally, the microcapsules are mixed with an organic fluorine-silicon modified resin and a platinum-based catalyst in a mass ratio of (8-10): (4-5): 1, and nano-SiO2 is added. The nano-SiO2 has a particle size of 20-50 nm and a mass fraction of 3-4%. The prepared microcapsule repair agent is sealed and stored. S2. Construction of nanocomposite system: First, a gradient filling method is used to mix micron-sized talc powder and nano-sized silicon carbide in a mass ratio of 1:1; Then, the glass fiber is impregnated with dopamine solution to enhance the shear strength of the resin matrix interface to ≥45MPa; Finally, the modified glass fiber is cut into short fibers, mixed with the wax matrix at a mass ratio of 1:(8-10), and 3-8 parts of the microcapsule repair agent prepared in step 1 are added. The mixture is stirred at a low speed of 500-600 rpm for 15 minutes until the system is evenly dispersed, thereby forming a nanocomposite reinforcement slurry containing the repair agent; S3. Coating and curing: Mix the waxy base component A and component B at a ratio of 4: (1-1.1), and cross-link with the water-based polymer and ionic modified resin to form a base layer; Mix modified polyamide wax and polytetrafluoroethylene wax powder in a ratio of 4: (1-1.1), add 20-30 parts of polyethylene wax powder and 5-8 parts of nanoclay to form an intermediate layer; The nanocomposite reinforcement slurry prepared in step S2 is impregnated with glass fiber fabric and then laid to form a reinforcement layer; The graphene / silicon carbide composite filler is mixed with a waxy matrix and then coated to form a surface layer; Finally, the film was cured at 90°C for 30 minutes with a heating rate of ≤5°C / min.

8. The method for preparing the self-repairing waxy heavy-duty anti-corrosion coating according to claim 7, characterized in that: The interfacial polymerization reaction conditions of the microcapsule repair agent are: temperature 40-60° C., pH value 2-4, and reaction time 2-4 hours.

9. The method for preparing the self-repairing waxy heavy-duty anti-corrosion coating according to claim 7, characterized in that: The impregnation time of the dopamine-modified glass fiber in the nanocomposite system is 1-2 hours, and the length of the modified fiber is 0.5-2 mm.

10. The method for preparing the self-repairing waxy heavy-duty anti-corrosion coating according to claim 7, characterized in that: The polyethylene wax powder content of the middle layer in the layered coating is 20-30%, and the nano clay content is 5-8%.

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