Wear-resistant and corrosion-resistant nano composite coating for metal surface and preparation method thereof

Abstract

The invention relates to the technical field of metal surface protection materials, in particular to a wear-resistant anticorrosive coating based on a nano-composite technology and a preparation method thereof, which are suitable for surface protection of metal pipelines and equipment in harsh environments such as chemical equipment, ocean engineering, electric power facilities and the like. The invention relates to a high-temperature-resistant flame-retardant coating which comprises the following raw material components in parts by weight: 20-30 parts of nano aluminum oxide; 10 to 15 parts of nano titanium oxide; 1 to 3 parts of graphene; 1-3 parts of a composite filler; 3-5 parts of a silane coupling agent; 40 to 50 parts of modified epoxy resin; 10-15 parts of a curing agent; 5-8 parts of a toughening agent; 2-4 parts of an anti-wear agent; and 0.5-1 part of a leveling agent. Under the combined action of all the components, the obtained wear-resistant and corrosion-resistant nano composite ceramic coating for the metal surface has excellent high temperature resistance, corrosion resistance, wear resistance, aging resistance and bonding strength.

Description

Technical Field

[0001] This invention relates to the field of metal surface protection materials, specifically a wear-resistant and corrosion-resistant coating based on nanocomposite technology and its preparation method, which is suitable for surface protection of metal pipes and equipment in harsh environments such as chemical equipment, marine engineering, and power facilities. Background Technology

[0002] Anti-corrosion and wear-resistant coatings for metal surfaces play a crucial role in modern industry, especially in harsh environments such as chemical, marine, and power industries. With rapid industrial development, the performance requirements for anti-corrosion and wear-resistant materials for metal surfaces are constantly increasing.

[0003] Traditional epoxy resin coatings suffer from insufficient hardness (typically <3H) and poor abrasion resistance (Taber abrasion value >50mg / 1000 rpm). Single filler systems (such as pure silicon carbide) lead to decreased coating toughness, making them prone to cracking under impact loads. Graphene exhibits poor dispersibility and is prone to agglomeration, weakening its anti-corrosion performance. Insufficient temperature resistance (long-term operating temperature <150℃) limits its application in high-temperature environments. Therefore, it is urgent to address how to synergistically improve the coating's hardness, abrasion resistance, corrosion resistance, and high-temperature stability, while simultaneously resolving the issues of nanomaterial dispersibility and interfacial adhesion. Summary of the Invention

[0004] To address the above problems, this invention proposes a wear-resistant and corrosion-resistant nanocomposite coating for metal surfaces and its preparation method.

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies. This invention primarily improves hardness and wear resistance by using nanomaterials, introducing graphene, CNTs, and modified resins into a composite, and adding compound fillers to the resin to enhance the heat resistance, corrosion resistance, tensile toughness, and reduce the coefficient of friction of the epoxy resin. Through the combined action of the components, this invention produces a wear-resistant and corrosion-resistant nanocomposite ceramic coating for metal surfaces, exhibiting excellent high-temperature resistance, corrosion resistance, wear resistance, aging resistance, and bonding strength.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A wear-resistant and corrosion-resistant nanocomposite coating for metal surfaces, comprising the following raw material components by weight: Nano-alumina: 20-30 parts; Nano-titanium oxide: 10-15 parts; Graphene: 1-3 parts; Composite filler: 1-3 parts; Silane coupling agent: 3-5 parts; Modified epoxy resin: 40-50 parts; Curing agent: 10-15 parts; Toughening agent: 5-8 parts; Anti-wear agent: 2-4 parts; Leveling agent: 0.5-1 part.

[0007] Preferably, the composite coating further includes a solvent, said solvent including active and inactive solvents; The reactive diluents include propylene oxide butyl ether, diglycidyl ether, and acrylate monomers; the inactive diluents are ketones, aromatic hydrocarbons, alcohols, esters, or ethylene glycol ethers. The non-reactive diluent is an inert solvent.

[0008] The solvents mentioned above are used to reduce resin viscosity and improve workability.

[0009] Preferably, the graphene contains single-arm carbon nanotubes (CNTs).

[0010] Preferably, the composite filler comprises: silicon carbide, boron carbide, and silicon nitride.

[0011] Preferably, the modified epoxy resin is a modified epoxy vinyl ester resin.

[0012] Preferably, the curing agent comprises: ethylenediamine, hexamethylenediamine, diethylenetriamine, m-phenylenediamine, and 4,4'-diaminodiphenylmethane.

[0013] Preferably, the toughening agent comprises: carboxyl-terminated nitrile butadiene rubber, polysulfide rubber, silicone rubber, polyamide resin, polyvinyl butyral, and acrylate core-shell particles.

[0014] Preferably, the anti-wear agent includes fillers and additives; The filler includes: silicon carbide, corundum, graphite powder, molybdenum disulfide, and polytetrafluoroethylene micro powder; The additives include: siloxane polymers, hyperbranched polymers, and polyacrylates.

[0015] Preferably, the leveling agent comprises: polydimethylsiloxane, modified silicone oil, polyacrylate, or fluorocarbon.

[0016] A method for preparing a wear-resistant and corrosion-resistant nanocomposite coating for metal surfaces, characterized by comprising the following steps: S1: Premixing and solvation of resin base material S101. Resin Dissolution / Dilution: Add the weighed epoxy resin to the container and turn on the low-speed stirring at 300-500 rpm; S102. Add solvent: Add solvent slowly; the purpose is to achieve a viscosity that facilitates subsequent dispersion operations. The initial viscosity should be controlled at 2000-5000 mPa·s. The process involves adding a non-reactive solvent first, followed by adding a reactive diluent. S103. Add coupling agent: Slowly add silane coupling agent while stirring continuously; stir for 15-20 minutes to allow it to react initially with the resin; S104. Add toughening agent: Add toughening agent slowly to ensure it is completely mixed into the resin system; Continue stirring for 20-30 minutes; at this point, a homogeneous resin-toughening agent-solvent mixture is formed, which is component A: the base material. Heat to 40-50°C to reduce viscosity; S2: Predispersion and treatment of nanomaterials and fillers S201. Nano-alumina / titanium oxide pre-dispersion slurry: Take an inactive solvent and add weighed nano-alumina and nano-titanium oxide. Use a high-shear disperser at 2000-3000 rpm for initial dispersion for 10-15 minutes. Transfer to an ultrasonic processor for ultrasonic dispersion for 15-30 minutes, or use a nano-grinding mill to grind and disperse to a fineness of <50 μm; forming a stable and uniform nano-oxide slurry. S202. Graphene predispersed slurry; Using graphene predispersants or slurries, or dry powder: add a small amount of solvent to the graphene, first stir and wet at low speed, then disperse at high shear speed (0-4000 rpm) for 10 minutes; then subject to strong ultrasonic treatment for 30-60 minutes, or use a graphene dispersion device; the aim is to obtain a stable graphene dispersion slurry without obvious agglomeration.

[0017] S203. Composite filler dispersion: After adding composite filler to the resin, first use a high-shear disperser at a speed of 2000-3000 rpm for initial dispersion for 10-15 minutes, then transfer to an ultrasonic processor for ultrasonic dispersion for 15-30 minutes, or use a nano-grinding mill to grind and disperse to a fineness of <50 μm; to form a stable and uniform nano-filler slurry. S204. Anti-wear agent premix: Mix the anti-wear agent with component A base material or solvent, and disperse it for 10-15 minutes using a high shear disperser at a speed of 1500-2000 rpm to ensure no agglomeration and to form an anti-wear agent slurry.

[0018] S3: Mixing and Dispersion of Main Paint Materials S301. Mixed pre-dispersed slurry: The nano-oxide slurry obtained in step S201, the graphene dispersion slurry obtained in step S202, the nano-filler slurry obtained in step S203, and the anti-wear agent slurry obtained in step S204 are slowly added to the A component base material prepared in step S104; S302. High shear mixing and dispersion: Turn on the high shear disperser at a speed of 2000-3000 rpm and mix vigorously for 30-45 minutes to ensure that all slurry is evenly mixed into the resin matrix; S303. Add leveling agent: Reduce the stirring speed to 500-800 rpm, add leveling agent; stir for 10-15 minutes to disperse it evenly; S304. Viscosity Adjustment and Refinement: Check the viscosity; if it is too high, slowly add the reserved solvent to adjust it to the target application viscosity; Grinding and refining: Grind the mixed paint material 2-3 times using a three-roll mill; S305. Defoaming Vacuum degassing: Transfer the paint to a planetary mixer or a dedicated degassing tank, turn on the vacuum, and stir at low speed for 20-30 minutes until there are no obvious bubbles. Alternatively, allow the mixture to stand to remove bubbles, but cover it to prevent solvent evaporation.

[0019] S306. Filtration: Use a filter screen of appropriate mesh size to filter the paint to remove possible impurities and large particles, and obtain the final paint with component A as the main component; S4: Preparation of curing agent components S401. Selection and mixing of curing agent: The curing agent or mixture of curing agents is selected according to the application requirements; the curing agent mixture is an SSUO-modified aliphatic amine or an alicyclic amine; S402. Solvent dilution: If the selected curing agent has too high a viscosity or needs to be matched with a non-reactive solvent, dilute it with a non-reactive solvent, stir it evenly, and ensure that the dilution does not affect the curing reaction activity to obtain the curing agent of component B.

[0020] S403. Packaging and Storage: Seal the curing agent of component B separately and store it in a cool, dry place.

[0021] S5: Coating Application and Curing S501. Mixing: Before construction, accurately weigh component A and component B according to the weight ratio of component A: component B = 100: (10-15).

[0022] S502. Stirring and mixing: Slowly pour component B into component A, and use a stirring rod or low-speed mechanical stirrer to stir and mix thoroughly for 3-5 minutes to ensure uniform mixing; S503. Maturation: After mixing, let stand for 10-20 minutes to allow air bubbles to escape and for the two components to fully pre-react and reach the appropriate application viscosity; S504. Application: Apply the mixed coating to a metal substrate that has undergone rigorous surface treatment and has been sandblasted to Sa 2.5 or higher. S505. Curing: Curing at room temperature: Curing occurs at 23±2°C and relative humidity <75%; surface drying takes 2-4 hours; subsequent curing can be either complete drying or heat curing. Dry curing: 24 hours; complete curing requires 7 days or more. Heat curing: After surface drying, heat curing is performed; conditions: cure at 80-120°C for 1-4 hours.

[0023] S506. Post-treatment: After curing, the coating can be allowed to cool naturally.

[0024] This invention is mainly achieved through a four-fold collaborative mechanism: 1. Nano-ceramic particles (Al2O3 / TiO2) → Improve hardness and density; 2. Composite filler (SiC / B4C / Si3N4) → Optimizes friction coefficient and impact resistance; 3. Graphene / CNT hybrid system → Constructing a "maze-like" corrosion protection barrier + cathodic protection; 4. Modified resin matrix → Enhances heat resistance (>200℃) and interfacial bonding strength (adhesion ≥15MPa).

[0025] Compared with the prior art, the beneficial effects of the present invention are: 1. Nanomaterials enhance hardness and wear resistance: Nano-alumina and nano-titanium oxide, as the main ceramic fillers, impart extremely high hardness and wear resistance to the coating. These nanoparticles can form a dense protective layer, effectively resisting external wear.

[0026] 2. Composite Fillers: Epoxy resin, as the main film-forming substance, provides excellent adhesion and flexibility, ensuring a tight bond between the coating and the metal substrate, preventing it from easily peeling off. Adding composite fillers such as silicon carbide, boron carbide, and silicon nitride to the resin improves the material's hardness, corrosion resistance, reduces the coefficient of friction, and allows for better coating color matching, thus addressing certain performance deficiencies of single-type materials.

[0027] 3. Graphene Enhances Corrosion Resistance: Introducing graphene as an innovative element, its unique two-dimensional nanostructure and excellent conductivity create a "maze effect" in the coating, effectively delaying the penetration of corrosive media. Simultaneously, graphene also possesses a synergistic cathodic protection effect, further enhancing the coating's corrosion resistance. Physical Shielding: The layered structure of graphene effectively blocks the penetration of corrosive media, forming a robust protective barrier. Conductivity: Graphene's high conductivity contributes to the cathodic protection effect in the coating, further inhibiting corrosion of the metal substrate through electrochemical reactions. Enhanced Wear Resistance: Graphene's high strength and hardness further enhance the coating's wear resistance, extending its service life.

[0028] 4. Graphene-Reinforced Composites: Graphene possesses ultra-high strength, excellent electrical and thermal conductivity, large specific surface area, and chemical stability, which can significantly improve the mechanical properties, electrical conductivity, and corrosion resistance of the matrix material. Phenolic resin is modified to enhance the heat resistance, mechanical properties, and chemical stability of epoxy vinyl ester resin, while bromination modification aims to improve the flame retardancy and self-extinguishing properties of the material. By combining graphene with epoxy vinyl ester resin modified through phenolic, bromination, and toughening processes, the heat resistance, corrosion resistance, and toughness of the epoxy resin are further enhanced.

[0029] 5. Toughening agents prevent cracking: The addition of toughening agents improves the impact resistance and crack resistance of the coating, ensuring that the coating remains intact under complex stress environments. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the tables in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the appendix is ​​not intended to limit the scope of the claimed invention, but merely to represent selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention. Example 1

[0031] This invention provides a wear-resistant and corrosion-resistant nanocomposite coating for metal surfaces, characterized in that it comprises the following raw material components in parts by weight: Nanocomposite ceramic coating formulation: (components and parts by weight) 1. Nano-alumina: 20-30 parts 2. Nano titanium dioxide: 10-15 parts 3. Graphene: 1-3 parts (containing single-arm carbon nanotubes (CNTs), typically CNTs account for 10%) 4. Composite filler: 1-3 parts (silicon carbide, boron carbide, silicon nitride, etc., to be mixed in proportion as needed) 4. Silane coupling agent: 3-5 parts 5. Modified epoxy resin: 40-50 parts (modified epoxy vinyl ester resin) 6. Curing agent: 10-15 parts, mainly including ethylenediamine, hexamethylenediamine, diethylenetriamine, m-phenylenediamine, and 4,4'-diaminodiphenylmethane (DDM). 7. Toughening agents: 5-8 parts; mainly including carboxyl-terminated nitrile butadiene rubber (CTBN), polysulfide rubber, silicone rubber, polyamide resin (such as PA-650), polyvinyl butyral (PVAc), and acrylate core-shell particles. 8. Anti-wear agent: 2-4 parts; mainly includes fillers such as silicon carbide (SiC), corundum, graphite powder, molybdenum disulfide (MoS2), and polytetrafluoroethylene (PTFE) micro powder; additives include siloxane polymers, hyperbranched polymers, and polyacrylates. 9. Leveling agents: 0.5-1 part, mainly including (polydimethylsiloxane (PDMS), modified silicone oil (such as those containing hydroxyl or amino groups), polyacrylates, fluorocarbons (fluorinated polymers, polyether modified leveling agents)). 10. Appropriate amount of solvent: Used to reduce resin viscosity and improve workability, it is divided into active and inactive solvents. Active diluents include propylene oxide butyl ether (660), diglycidyl ether (600), and acrylate monomers (such as styrene); inactive diluents (inert solvents) include ketones, aromatic hydrocarbons, alcohols, esters, and some special solvents such as ethylene glycol ethers (such as ethylene glycol ethyl ether). Example 2

[0032] Preparation and Implementation Method of Anti-corrosion and Wear-resistant Nanocomposite Ceramic Coating for Metal Surface Objective: To prepare nanocomposite coatings with excellent corrosion resistance (physical shielding and electrochemical protection), high wear resistance, good adhesion, and workability.

[0033] Ensure uniform and stable dispersion of nanoparticles (Al2O3, TiO2, graphene) and anti-wear agents in the resin matrix to avoid agglomeration; control the rate and extent of the curing reaction.

[0034] Equipment: Constant temperature water bath (adjustable temperature 0-80°C), high shear disperser (speed 1000-5000 rpm), planetary mixer (with vacuum function, preferred), ultrasonic cell disruptor (or high-efficiency nano-grind mill), precision electronic balance, three-roll mill (optional, for refining), viscometer, thermometer, containers (stainless steel or solvent-resistant plastic), inert gas (such as N2) protection system (optional, beneficial for graphene-containing systems). Raw material preparation: Accurately weigh each component according to the formula.

[0035] Preparation steps: Phase 1: Premixing and Solventizing of Resin Base Material (Component A Base Material) 1. Resin Dissolution / Dilution: Add the weighed epoxy resin (45 parts) to a container. Turn on low-speed stirring (300-500 rpm).

[0036] 2. Add solvent: Slowly add a portion of the solvent. The amount of solvent added is crucial; the goal is to achieve a viscosity suitable for subsequent dispersion operations (typically, the initial viscosity is controlled at 2000-5000 mPa·s).

[0037] Recommendation: First, add most of the non-reactive solvents (such as xylene, n-butanol, and PMA mixed in proportion). If adjustments to the curing speed or final properties are needed, a portion of reactive diluent, such as propylene oxide butyl ether (660) or diglycidyl ether (600), can be added at this point. Note: The total amount of solvent must be controlled to ensure the final application viscosity meets requirements. Reserve some solvent for subsequent adjustments.

[0038] 3. Add coupling agent: Slowly add 4 parts of silane coupling agent while continuously stirring. Stir for 15-20 minutes to allow it to react initially with the resin.

[0039] 4. Add toughening agent: Slowly add the toughening agent (6 parts) (if CTBN, preheating is required to reduce viscosity). Ensure it is completely incorporated into the resin system. Continue stirring for 20-30 minutes. At this point, a homogeneous resin-toughening agent-solvent mixture (component A base material) will be formed. Appropriate heating (40-50°C) can be applied to reduce viscosity, but avoid excessively high temperatures that could lead to solvent evaporation or side reactions.

[0040] Phase Two: Pre-dispersion and treatment of nanomaterials and fillers (key step) 5. Nano-alumina / titanium oxide pre-dispersion slurry: Take an appropriate amount of inactive solvent (reserved in the formulation or a small additional amount), add the weighed nano-alumina (25 parts) and nano-titanium oxide (12 parts), and initially disperse using a high-shear disperser (2000-3000 rpm) for 10-15 minutes. Transfer to an ultrasonic processor and perform ultrasonic dispersion (adjust the power according to the equipment, avoid overheating, an ice bath can be used) for 15-30 minutes, or use a nano-grinding mill to grind and disperse until the fineness meets the requirements (<50 μm or better). A stable and uniform nano-oxide slurry is formed.

[0041] 6. Graphene predispersed slurry (key innovation): When using graphene predispersants or slurries (such as graphene / CNT / NMP slurries), if using dry powder: take a small amount of solvent (such as N-methylpyrrolidone NMP or a specific dispersant + solvent), add graphene (2 parts, of which CNT accounts for 10%), first stir at low speed to wet, then disperse at high shear (3000-4000 rpm) for 10 minutes. Immediately subject to strong ultrasonic treatment (high power, ice bath) for 30-60 minutes, or use a dedicated graphene dispersion device. The goal is to obtain a stable graphene dispersion slurry without significant agglomeration.

[0042] Note: Dry graphene powder is extremely difficult to disperse and its properties are easily damaged; therefore, pre-dispersed products should be preferred.

[0043] 7. Composite filler dispersion: Add composite filler (a mixture of silicon carbide, boron carbide, silicon nitride, etc.) (3 parts) to the resin and perform pre-dispersion treatment according to step 5.

[0044] 8. Anti-wear agent premixing: Mix the anti-wear agent (3 parts) (such as SiC, MoS2, PTFE micro powder) with a small amount of resin base (component A) or solvent, and disperse it for 10-15 minutes using a high-shear disperser (1500-2000 rpm) to ensure no agglomeration. This forms an anti-wear agent slurry.

[0045] Phase 3: Mixing and Dispersion of Main Paint Materials (Final Preparation of Component A) 9. Mixing and pre-dispersing slurry: The nano-oxide slurry obtained in step 5, the graphene slurry obtained in step 6, the nano-filler slurry obtained in step 7, and the anti-wear agent slurry obtained in step 8 are slowly added to the A component base material prepared in step 4.

[0046] 10. High-shear mixing and dispersion: Turn on the high-shear disperser (2000-3000 rpm) and mix vigorously for 30-45 minutes. Ensure that all slurry is evenly incorporated into the resin matrix.

[0047] 11. Add leveling agent: Reduce the stirring speed (500-800 rpm) and add leveling agent (0.7 parts). Stir for 10-15 minutes to disperse it evenly.

[0048] 12. Viscosity Adjustment and Refining: Check the viscosity. If it is too high, slowly add the reserved solvent (reactive or inactive, as needed) to adjust to the target application viscosity. (Highly Recommended) Grinding and Refining: Grind the mixed paint using a three-roll mill 2-3 times. This step is crucial for breaking up any potential soft agglomerates, ensuring uniform dispersion of nanoparticles, and improving film density and gloss.

[0049] 13. Defoaming (Important): Vacuum degassing: Transfer the paint to a planetary mixer (with vacuum) or a dedicated degassing tank, turn on the vacuum (recommended >-0.095 MPa), and stir at low speed for 20-30 minutes until no obvious bubbles are visible.

[0050] Alternatively, allow the mixture to stand and degas: Stir at low speed for a long time or let it stand overnight (cover to prevent solvent evaporation).

[0051] 14. Filtration: Use a filter with an appropriate mesh size (e.g., 100-200 mesh) to filter the paint to remove possible impurities and large particles. This yields the final component A (main paint).

[0052] 15. Packaging and Storage: Seal component A in its packaging and store in a cool, dry place. Label the component, batch number, and date.

[0053] Phase Four: Preparation of Curing Agent Components (Component B) 16. Curing Agent Selection and Mixing: Select a suitable curing agent (10-15 parts) or a mixture of curing agents (such as modified aliphatic amines / cycloaliphatic amines for low-temperature curing, and DDM for high-temperature performance) based on application requirements (e.g., construction conditions, curing speed requirements, temperature resistance, and toughness requirements). Mixed curing agents are commonly used to adjust performance.

[0054] 17. Solvent Dilution (if necessary): If the selected curing agent has a high viscosity or needs to be matched with a non-reactive solvent, it can be diluted with a small amount of non-reactive solvent (such as alcohols or ketones) and stirred evenly. Ensure that dilution does not affect the curing reactivity. This yields component B (curing agent).

[0055] 18. Packaging and Storage: Seal component B separately and store in a cool, dry place. Label the components, batch number, and date. Special Note: Amine-based curing agents are hygroscopic and oxidizable; therefore, they must be strictly sealed.

[0056] Phase 5: Coating Application and Curing 19. Mixing: Before application, accurately weigh component A and component B according to the weight ratio of A:B = 100 : (10-15) (the specific ratio needs to be determined based on the selected curing agent and experiments).

[0057] 20. Mixing: Slowly pour component B into component A and mix thoroughly for 3-5 minutes with a stirring rod or low-speed mechanical mixer to ensure even mixing. Avoid introducing too many air bubbles with high-speed mixing.

[0058] 21. Maturation: After mixing, let stand for 10-20 minutes (maturation time should be adjusted according to the specific system) to allow air bubbles to escape and for the two components to fully pre-react and reach the appropriate application viscosity.

[0059] 22. Application: Apply the mixed coating to a metal substrate that has undergone rigorous surface treatment (sandblasting to Sa 2.5 or higher, clean and dry) using conventional methods (brush, roller, spray). Control the wet film thickness.

[0060] 23. Curing: Curing at room temperature: Cures at 23±2°C and relative humidity <75%. Surface dryness typically takes 2-4 hours, hard dryness 24 hours, and complete curing (to achieve optimal performance) takes 7 days or longer (depending on the hardener).

[0061] Heat curing: To shorten the construction period or improve performance (especially crosslinking density and temperature resistance), heat curing can be performed after surface drying. Common conditions: Curing at 80-120°C for 1-4 hours. It is essential to determine the optimal heating program and temperature based on the selected resin / curing agent system to avoid blistering and cracking.

[0062] 24. Post-treatment: After curing, the coating can be allowed to cool naturally. Perform necessary performance tests (adhesion, thickness, hardness, impact resistance, salt spray resistance, abrasion resistance, etc.).

[0063] 1. Nanoparticle dispersion is key: Steps 5, 6, and 7 are crucial in determining the final performance of the coating (corrosion resistance, abrasion resistance, and strength). It is essential to ensure that the nanoparticles (especially graphene) are highly dispersed and stable, avoiding agglomeration. Ultrasonication and grinding are necessary methods.

[0064] 2. Solvent Selection and Dosage: The solvent system directly affects dispersion, workability, VOCs, and final coating quality. A balance must be struck between solubility, evaporation rate, and reactive diluent reactivity. The total amount must be strictly controlled.

[0065] 3. Mixing order: Follow the principle of starting with the easy parts and then moving to the difficult parts (spreading out the difficulty), and premix before main mixing, which is conducive to obtaining a homogeneous system.

[0066] 4. Debubbling: Bubbles are the source of coating defects, which seriously affect corrosion resistance and appearance, and must be completely removed.

[0067] 5. Grinding and refining: Three-roll milling can significantly improve dispersion quality and coating density, and is highly recommended.

[0068] 6. A / B mixing ratio and curing: The mixing ratio must be strictly followed according to the experimentally determined ratio. Insufficient curing time may result in poor leveling and many air bubbles; excessive curing time will increase viscosity, making it difficult to apply or even causing gelation.

[0069] 7. Substrate preparation: Even the best coatings rely on excellent surface preparation (sandblasting to remove rust, cleaning and degreasing). Surface preparation quality is a prerequisite for the long-term effectiveness of the coating.

[0070] 8. Curing conditions: Curing temperature and time have a significant impact on the final properties (crosslinking density, Tg, chemical resistance, mechanical strength). They must be optimized based on the selected resin / curing agent system.

[0071] 9. Safety and Environmental Protection: Operations should be carried out in a well-ventilated area, and protective equipment (gloves, goggles, mask) should be worn. Solvents and amine curing agents are flammable and toxic; waste must be properly stored and disposed of. Take precautions against static electricity (including graphene systems).

[0072] 10. Batch Stability: Strict control of raw material quality and process parameters (temperature, time, rotation speed, dispersion / grinding energy) is fundamental to ensuring consistent coating performance across different batches. It is recommended to establish detailed production records and quality control points (such as viscosity, fineness, and solids content).

[0073] This preparation method is based on cutting-edge formulation design, combining nano-dispersion technology, composite material processing, and coating engineering practices. In actual production, the specific parameters of each step (such as rotation speed, time, temperature, and solvent ratio) need to be optimized and solidified through small-scale and pilot-scale tests to meet the performance requirements of specific application scenarios and the feasibility of large-scale production.

[0074] 1. Excellent overall performance: This formula combines the high hardness of nano-ceramic materials, the excellent corrosion resistance of graphene, and the good adhesion of epoxy resin, resulting in a significant improvement in overall performance.

[0075] 2. Environmentally friendly: The formula minimizes the amount of harmful ingredients and meets modern industrial environmental protection requirements.

[0076] 3. Wide range of applications: Applicable to various metal surfaces, especially effective in harsh environments such as chemical equipment, marine engineering, and power facilities.

[0077] Through the application of the above innovative formulas, the performance of anti-corrosion and wear-resistant coatings for metal surfaces has been significantly improved, providing a reliable guarantee for the long-term stable operation of industrial equipment. Table 1 is a data quantification table of the intended effects:

[0078] Table 1 The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A wear-resistant and corrosion-resistant nanocomposite coating for metal surfaces, characterized in that, By weight, it includes the following raw material components: Nano-alumina: 20-30 parts; Nano-titanium oxide: 10-15 parts; Graphene: 1-3 parts; Composite filler: 1-3 parts; Silane coupling agent: 3-5 parts; Modified epoxy resin: 40-50 parts; Hardener: 10-15 parts; Toughening agent: 5-8 parts; Anti-wear agent: 2-4 parts; Leveling agent: 0.5-1 part.

2. The wear-resistant and corrosion-resistant nanocomposite coating for metal surfaces and its preparation method according to claim 1, characterized in that: The composite coating also includes a solvent, which includes both reactive and non-reactive solvents; The reactive diluents include propylene oxide butyl ether, diglycidyl ether, and acrylate monomers; the inactive diluents are ketones, aromatic hydrocarbons, alcohols, esters, or ethylene glycol ethers. The inactive diluent is an inert solvent; The solvents mentioned above are used to reduce resin viscosity and improve workability.

3. The wear-resistant and corrosion-resistant nanocomposite coating for metal surfaces and its preparation method according to claim 1, characterized in that: The graphene contains single-arm carbon nanotubes (CNTs).

4. The wear-resistant and corrosion-resistant nanocomposite coating for metal surfaces and its preparation method according to claim 1, characterized in that: The composite filler comprises: silicon carbide, boron carbide, and silicon nitride.

5. The wear-resistant and corrosion-resistant nanocomposite coating for metal surfaces and its preparation method according to claim 1, characterized in that: The modified epoxy resin is a modified epoxy vinyl ester resin.

6. The wear-resistant and corrosion-resistant nanocomposite coating for metal surfaces and its preparation method according to claim 1, characterized in that: The curing agent comprises: ethylenediamine, hexamethylenediamine, diethylenetriamine, m-phenylenediamine, and 4,4'-diaminodiphenylmethane.

7. The wear-resistant and corrosion-resistant nanocomposite coating for metal surfaces and its preparation method according to claim 1, characterized in that: The toughening agent comprises: carboxyl-terminated nitrile butadiene rubber, polysulfide rubber, silicone rubber, polyamide resin, polyvinyl butyral, and acrylate core-shell particles.

8. The wear-resistant and corrosion-resistant nanocomposite coating for metal surfaces and its preparation method according to claim 1, characterized in that: The anti-wear agent includes fillers and additives; The filler includes: silicon carbide, corundum, graphite powder, molybdenum disulfide, and polytetrafluoroethylene micro powder; The additives include: siloxane polymers, hyperbranched polymers, and polyacrylates.

9. The wear-resistant and corrosion-resistant nanocomposite coating for metal surfaces and its preparation method according to claim 1, characterized in that: The leveling agent contains: polydimethylsiloxane, modified silicone oil, polyacrylate, and fluorocarbons.

10. A method for preparing a wear-resistant and corrosion-resistant nanocomposite coating for metal surfaces as described in claims 1-9, characterized in that, Includes the following steps: S1: Premixing and solvation of resin base material S101. Resin Dissolution / Dilution: Add the weighed epoxy resin to the container and turn on the low-speed stirring at 300-500 rpm; S102. Add solvent: Add solvent slowly; The goal is to achieve a viscosity that facilitates subsequent dispersion operations; the initial viscosity is controlled between 2000-5000 mPa·s. The process involves adding a non-reactive solvent first, followed by adding a reactive diluent. S103. Add coupling agent: Slowly add silane coupling agent while stirring continuously; stir for 15-20 minutes to allow it to react initially with the resin; S104. Add toughening agent: Add toughening agent slowly to ensure it is completely mixed into the resin system; Continue stirring for 20-30 minutes; at this point, a homogeneous resin-toughening agent-solvent mixture is formed, which is component A: the base material. Heat to 40-50°C to reduce viscosity; S2: Predispersion and treatment of nanomaterials and fillers S201. Nano-alumina / titanium oxide pre-dispersion slurry: Take an inactive solvent and add weighed nano-alumina and nano-titanium oxide. Use a high-shear disperser at 2000-3000 rpm for initial dispersion for 10-15 minutes. Transfer to an ultrasonic processor for ultrasonic dispersion for 15-30 minutes, or use a nano-grinding mill to grind and disperse until the fineness is < 50 μm; forming a stable and uniform nano-oxide slurry. S202. Graphene predispersed slurry; Using graphene predispersants or slurries, or dry powder: add a small amount of solvent to the graphene, first stir at low speed to wet it, then disperse at high shear speed (0-4000 rpm) for 10 minutes; then subject it to strong ultrasonic treatment for 30-60 minutes, or use a graphene dispersion device; the aim is to obtain a stable graphene dispersion slurry without obvious agglomeration. S203. Composite filler dispersion: After adding composite filler to the resin, first use a high-shear disperser at a speed of 2000-3000 rpm for initial dispersion for 10-15 minutes, then transfer to an ultrasonic processor for ultrasonic dispersion for 15-30 minutes, or use a nano-grinding mill to grind and disperse to a fineness of < 50 μm; to form a stable and uniform nano-filler slurry. S204. Anti-wear agent premix: Mix the anti-wear agent with component A base material or solvent, and disperse it for 10-15 minutes using a high shear disperser at a speed of 1500-2000 rpm to ensure no agglomeration and to form an anti-wear agent slurry; S3: Mixing and Dispersing of Main Paint Materials S301. Mixed pre-dispersed slurry: The nano-oxide slurry obtained in step S201, the graphene dispersion slurry obtained in step S202, the nano-filler slurry obtained in step S203, and the anti-wear agent slurry obtained in step S204 are slowly added to the A component base material prepared in step S104; S302. High shear mixing and dispersion: Turn on the high shear disperser at a speed of 2000-3000 rpm and mix vigorously for 30-45 minutes to ensure that all slurry is evenly mixed into the resin matrix; S303. Add leveling agent: Reduce the stirring speed to 500-800 rpm, add leveling agent; stir for 10-15 minutes to disperse it evenly; S304. Viscosity Adjustment and Refinement: Check the viscosity; if it is too high, slowly add the reserved solvent to adjust it to the target application viscosity; Grinding and refining: Grind the mixed paint material 2-3 times using a three-roll mill; S305. Defoaming Vacuum degassing: Transfer the paint to a planetary mixer or a dedicated degassing tank, turn on the vacuum, and stir at low speed for 20-30 minutes until there are no obvious bubbles. Alternatively, allow the mixture to stand to remove bubbles, but cover it to prevent solvent evaporation. S306. Filtration: Use a filter screen of appropriate mesh size to filter the paint to remove possible impurities and large particles, and obtain the final paint with component A as the main component; S4: Preparation of curing agent components S401. Selection and mixing of curing agent: The curing agent or mixture of curing agents is selected according to the application requirements; the curing agent mixture is an SSUO-modified aliphatic amine or an alicyclic amine; S402. Solvent dilution: If the selected curing agent has too high a viscosity or needs to be matched with a non-reactive solvent, dilute it with a non-reactive solvent, stir it evenly, and ensure that the dilution does not affect the curing reaction activity to obtain the curing agent of component B. S403. Packaging and Storage: Seal the curing agent of component B separately and store it in a cool, dry place; S5: Coating Application and Curing S501. Mixing: Before construction, accurately weigh component A and component B according to the weight ratio of component A: component B = 100: (10-15); S502. Stirring and mixing: Slowly pour component B into component A, and use a stirring rod or low-speed mechanical stirrer to stir and mix thoroughly for 3-5 minutes to ensure uniform mixing; S503. Maturation: After mixing, let stand for 10-20 minutes to allow air bubbles to escape and the two components to fully pre-react and reach the appropriate application viscosity; S504. Application: Apply the mixed coating to a metal substrate that has undergone rigorous surface treatment and has been sandblasted to Sa 2.5 or higher. S505. Curing: Curing at room temperature: Curing occurs at 23±2°C and relative humidity < 75%; surface drying takes 2-4 hours; subsequent curing can be either complete drying or heat curing. Dry curing: 24 hours; complete curing requires 7 days or more. Heat curing: After surface drying, heat cure; conditions: cure at 80-120°C for 1-4 hours; S506. Post-treatment: After curing, the coating can be allowed to cool naturally.

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