Ultrahigh-solid-content waterborne epoxy anticorrosive marine coating and preparation method thereof

Abstract

The invention discloses an ultrahigh-solid-content waterborne epoxy anticorrosive marine coating and a preparation method thereof, the coating is composed of a component A and a component B, and the parts of all the components are all in parts by weight. Wherein the component A is prepared from 40 to 70 parts of waterborne epoxy emulsion, 8 to 15 parts of modified graphene, 5 to 12 parts of modified mica powder, 6 to 15 parts of anti-rust pigment, 0.5 to 2 parts of dispersing agent, 0.5 to 0.8 part of defoaming agent, 2 to 4 parts of flatting agent and 20 to 25 parts of water; the component B comprises the following components in parts by weight: 35-50 parts of a waterborne epoxy curing agent, 0.8-1.6 parts of a flash rust inhibitor, 7-12 parts of an auxiliary agent and 10-25 parts of water; the mass ratio of the component A to the component B is (1-3): (1-2). The coating system provided by the invention has the characteristic of high solid content, can improve the corrosion resistance and durability of a ship structure in a marine environment, is beneficial to prolonging the service life of the ship structure, and reduces the environmental load.

Description

Technical Field

[0001] This invention pertains to anti-corrosion coatings and their preparation methods, specifically relating to an ultra-high solids water-based epoxy anti-corrosion marine coating and its preparation method. Background Technology

[0002] Ships are constantly exposed to high-salinity, humid seawater and the marine atmosphere rich in chloride ions. Since their hulls and components are largely composed of steel and copper alloys, they are highly susceptible to corrosion, severely threatening their safety and performance. In recent years, with the continuous increase in the use of various types of ships and marine facilities, the maintenance costs and safety risks caused by corrosion have become increasingly prominent. Therefore, strengthening corrosion protection for ships is of great engineering significance.

[0003] Currently, common methods for ship corrosion protection include cathodic protection, anti-corrosion coatings, corrosion inhibitors, material surface modification, anodizing, and electroplating of metal protective layers. Among these, anti-corrosion coatings are the most cost-effective and widely used method due to their unique advantages such as low cost, fast application, and strong corrosion resistance. Among the many organic anti-corrosion coatings, epoxy resin is widely used due to its excellent mechanical and chemical properties and designability. Epoxy resin can be applied in a liquid state and can reach its final application requirements after curing at room temperature or with heat.

[0004] In existing technologies, while epoxy anti-corrosion marine coatings improve corrosion resistance and thick coating performance, they still face environmental protection issues related to volatile organic compound (VOC) emissions. Therefore, the development of high-solids marine coatings is of great significance. Summary of the Invention

[0005] Objective of the Invention: To overcome the shortcomings of existing technologies, this invention provides an ultra-high solids content water-based epoxy anti-corrosion marine coating and its preparation method. The polyurethane / epoxy resin composite system used in this coating enables the coating to have higher corrosion resistance and service life in marine environments, while reducing environmental impact.

[0006] Technical solution: The first aspect of this invention provides an ultra-high solids water-based epoxy anti-corrosion marine coating, comprising component A and component B, wherein the proportions of each component are by weight, as detailed below: Component A includes: 40-70 parts of waterborne epoxy emulsion; 8-15 parts of modified graphene; 5-12 parts of modified mica powder; 6-15 parts of anti-rust pigment; 0.5-2 parts of dispersant; 0.5-0.8 parts of defoamer; 2-4 parts of leveling agent; and 20-25 parts of water. Component B includes: 35-50 parts of water-based epoxy curing agent; 0.8-1.6 parts of flash rust inhibitor; 7-12 parts of additives; and 10-25 parts of water. The mass ratio of component A to component B is 1~3:1~2.

[0007] The aqueous epoxy emulsion is prepared by the following method: firstly, a carboxyl-containing polyurethane prepolymer is prepared using toluene diisocyanate, polyethylene glycol and 2,2-dimethylolpropionic acid as raw materials; then, the carboxyl-containing polyurethane prepolymer is compounded with epoxy resin.

[0008] The mass ratio of toluene diisocyanate, polyethylene glycol, and 2,2-dimethylolpropionic acid is 1~3:2~5:1.

[0009] The mass ratio of the carboxyl-containing polyurethane prepolymer to the epoxy resin is 1.2~3:5~11.

[0010] The modified graphene is prepared by mixing graphene oxide and carbon fiber and then performing surface composite modification to obtain carbon fiber modified graphene, wherein the mass ratio of carbon fiber to graphene oxide is 1~2:3~5.

[0011] The modified mica powder is prepared by reacting sericite with γ-aminopropyltriethoxysilane and then mixing it with polyimide.

[0012] The mass ratio of γ-aminopropyltriethoxysilane, sericite, and polyimide is 1~2:5~11:1~3.

[0013] Preferably, the additive is selected from at least one of diluent, thixotropic agent and antisettling agent.

[0014] Preferably, the diluent can be selected from at least one of xylene, n-butanol, ethyl acetate, butyl acetate, and tetrahydrofuran; the thixotropic agent can be polyamide wax powder or fumed silica.

[0015] Secondly, the preparation method of the ultra-high solids water-based epoxy anti-corrosion marine coating includes the following steps: (1) According to the weight ratio of component A, add dispersant, modified graphene, modified mica powder and anti-rust pigment to water in sequence, stir evenly, add water-based epoxy emulsion, defoamer and leveling agent, mix evenly to obtain component A; (2) According to the weight ratio of component B, add the anti-flash rust agent and additives to water, stir evenly, add water-based epoxy curing agent, mix evenly, and obtain component B; (3) Mix components A and B according to their weight ratio and stir until homogeneous to obtain an ultra-high solids water-based epoxy anti-corrosion marine coating.

[0016] Compared with the prior art, the present invention has the following advantages: In this invention, a carboxyl-containing polyurethane prepolymer is prepared using toluene diisocyanate, polyethylene glycol, and 2,2-dimethylolpropionic acid as raw materials, and the carboxyl-containing polyurethane prepolymer is added to an epoxy resin to obtain an aqueous epoxy emulsion. Carboxyl-containing polyurethane segments act as soft, elastic segments in the crosslinking network, making the coating less prone to cracking at low temperatures or under impact and resisting substrate deformation. On one hand, carboxyl groups can undergo ring-opening reactions with epoxy groups in epoxy resin at certain temperatures to form ester bonds; on the other hand, they can undergo dehydration and salt formation or coordination reactions with metal hydroxyl groups on the surface of the metal substrate to form stable metal-carboxylic acid ester bonds, essentially building a chemical bridge between the resin molecules and the metal surface, thereby enhancing the interfacial bonding between the resin and the metal substrate. The hydrophilicity of carboxyl groups complements the hydrophobicity of polyurethane, forming a dense microstructure that helps inhibit the penetration of moisture and salt spray, improving corrosion resistance. Covalent crosslinking of carboxyl groups with epoxy can form a higher crosslinking density, increasing the glass transition temperature of the coating and maintaining stable performance over a wide temperature range of -30℃ to 120℃, while reducing the aging rate under long-term marine exposure conditions. Furthermore, the end-group structure of the prepolymer (terminated hydroxyl or isocyanate) gives the emulsion better dispersion and stability in the aqueous phase, reducing particle aggregation and forming a smooth, dense paint film. The addition of carboxyl-containing polyurethane prepolymers can improve the flexibility, adhesion, corrosion resistance, heat and weather resistance, and abrasion resistance of ultra-high solids water-based epoxy anti-corrosion marine coatings.

[0017] 2. In this invention, graphene oxide is rich in active functional groups such as hydroxyl, carboxyl, and epoxy groups, and typically exhibits a negative potential in aqueous dispersion systems; while carbon fiber surfaces possess active functional groups such as hydroxyl and amino groups, and their surface potential is typically weakly positive. Under an applied electric field, graphene oxide sheets migrate and deposit on the carbon fiber surface. The hydroxyl groups on the graphene oxide surface can form hydrogen bonds with the polar groups on the carbon fiber surface; simultaneously, the epoxy groups can undergo ring-opening reactions with the hydroxyl and amino groups on the carbon fiber surface, thereby forming strong covalent bonds at the interface. During the curing process, the epoxy groups of the epoxy resin can react with the active hydrogen groups on the hydroxyl and carboxyl functional groups on the graphene oxide surface, and can also form chemical bonds with the active hydrogen groups on the carbon fiber surface, further enhancing the interfacial adhesion between the fiber and the epoxy resin. Based on the above structure, the layered barrier effect provided by the graphene oxide sheets, combined with the dense network structure constructed by the carbon fiber, can jointly improve the corrosion resistance of the system. Among them, carbon fiber modified graphene oxide forms a tight three-dimensional network structure between the fiber and the epoxy matrix through multiple chemical bonds, thereby effectively inhibiting the penetration of moisture, oxygen and chloride ions.

[0018] 3. This invention modifies sericite with γ-aminopropyltriethoxysilane, improving its dispersibility and interfacial bonding in epoxy systems. The modified mica forms a dense, layered barrier structure in the coating; polyimide, on the other hand, imparts high-temperature stability and mechanical strength to the coating. The two work synergistically in ultra-high solids water-based epoxy anti-corrosion systems, enhancing the coating's resistance to salt spray, high temperatures, and impact, thus extending the service life of the hull. It also possesses high hardness, high adhesion, excellent water and chemical resistance, as well as good flexibility and ease of application. Detailed Implementation

[0019] The present invention will be further described in detail below with reference to the embodiments. It should be noted that: unless otherwise specified, the conditions in the following embodiments are carried out according to conventional conditions or the conditions recommended by the manufacturer. Unless otherwise specified, the raw materials used in the following embodiments can be obtained from commercially available sources.

[0020] Example 1 The ultra-high solids water-based epoxy anti-corrosion marine coating of this embodiment includes the following components A and B, with the proportions of each component being by weight: Component A includes: 40 parts of waterborne epoxy emulsion; 8 parts of modified graphene; 5 parts of modified mica powder; 6 parts of anti-rust pigment; 0.5 parts of dispersant; 0.5 parts of defoamer; 2 parts of leveling agent; and 20 parts of water. Component B comprises: 35 parts water-based epoxy curing agent; 0.8 parts flash rust inhibitor; 7 parts additives; and 10 parts water. The mass ratio of component A to component B is 1:2.

[0021] Aqueous epoxy emulsions are prepared as follows: Polyethylene glycol, after vacuum dehydration at 100–110°C, is cooled to 50–60°C. Toluene diisocyanate and dibutyltin dilaurate catalyst are added. Under nitrogen protection, the mixture is stirred and heated to 75–85°C for 1.5–2.5 hours. The temperature is then lowered to 60–70°C, and 2,2-dimethylolpropionic acid is added in batches. The mixture is then heated to 70–80°C and reacted for another 2–3 hours until the isocyanate content reaches a predetermined value, thus obtaining a carboxyl-containing emulsion with side chains. Isocyanate-terminated polyurethane prepolymer; the carboxyl-containing polyurethane prepolymer prepared above is cooled to 30-50℃, epoxy resin is added, and the mixture is thoroughly mixed under stirring. The mixture is then kept at 30-60℃ for 1-3 hours to complete the composite reaction of the polyurethane prepolymer and epoxy resin, thus obtaining an aqueous epoxy emulsion intermediate; the mass ratio of toluene diisocyanate, polyethylene glycol, and 2,2-dimethylolpropionic acid is 1:2:1; the mass ratio of carboxyl-containing polyurethane prepolymer to epoxy resin is 1.2:5.

[0022] Graphene oxide and carbon fiber were uniformly mixed at a mass ratio of 1:3, and carbon fiber modified graphene was obtained by surface composite modification.

[0023] Sericite was dispersed in a solvent, and γ-aminopropyltriethoxysilane was added. The mixture was stirred at 40–60 °C for 2–4 h to modify the silane surface of the sericite. After separation and drying, surface-modified sericite was obtained. The modified sericite was then mixed uniformly with polyimide at a mass ratio of 1:5:1 to obtain modified mica powder. The auxiliary agents were selected from diluents and thixotropic agents. The diluent was xylene, and the thixotropic agent was polyamide wax micropowder.

[0024] The preparation method of the ultra-high solids water-based epoxy anti-corrosion marine coating in this embodiment includes the following steps: (1) According to the weight ratio of component A, add dispersant, modified graphene, modified mica powder and anti-rust pigment to water in sequence, stir evenly, add water-based epoxy emulsion, defoamer and leveling agent, mix evenly to obtain component A; (2) According to the weight ratio of component B, add the anti-flash rust agent and additives to water, stir evenly, add water-based epoxy curing agent, mix evenly, and obtain component B; (3) Mix components A and B according to their weight ratio and stir until homogeneous to obtain an ultra-high solids water-based epoxy anti-corrosion marine coating.

[0025] Example 2 The ultra-high solids water-based epoxy anti-corrosion marine coating of this embodiment includes the following components A and B, with the proportions of each component being by weight: Component A includes: 50 parts of waterborne epoxy emulsion; 9 parts of modified graphene; 6 parts of modified mica powder; 8 parts of anti-rust pigment; 0.8 parts of dispersant; 0.6 parts of defoamer; 2 parts of leveling agent; and 20 parts of water. Component B comprises: 40 parts of water-based epoxy curing agent; 1 part of flash rust inhibitor; 7 parts of additives; and 10 parts of water. The mass ratio of component A to component B is 2:1.

[0026] Aqueous epoxy emulsions are prepared as follows: Polyethylene glycol, after vacuum dehydration at 100–110°C, is cooled to 50–60°C. Toluene diisocyanate and dibutyltin dilaurate catalyst are added. Under nitrogen protection, the mixture is stirred and heated to 75–85°C for 1.5–2.5 hours. The temperature is then lowered to 60–70°C, and 2,2-dimethylolpropionic acid is added in batches. The mixture is then heated to 70–80°C and reacted for another 2–3 hours until the isocyanate content reaches a predetermined value, thus obtaining a carboxyl-containing emulsion with side chains. Isocyanate-terminated polyurethane prepolymer; the carboxyl-containing polyurethane prepolymer prepared above is cooled to 30-50℃, epoxy resin is added, and the mixture is thoroughly mixed under stirring. The mixture is then kept at 30-60℃ for 1-3 hours to complete the composite reaction of the polyurethane prepolymer and epoxy resin, thus obtaining an aqueous epoxy emulsion intermediate; the mass ratio of toluene diisocyanate, polyethylene glycol, and 2,2-dimethylolpropionic acid is 1:3:1; the mass ratio of carboxyl-containing polyurethane prepolymer to epoxy resin is 1.5:7.

[0027] Graphene oxide and carbon fiber were uniformly mixed at a mass ratio of 1:4, and carbon fiber modified graphene was obtained by surface composite modification.

[0028] Sericite was dispersed in a solvent, and γ-aminopropyltriethoxysilane was added. The mixture was stirred at 40–60 °C for 2–4 h to modify the silane surface of the sericite. After separation and drying, surface-modified sericite was obtained. The modified sericite was then mixed uniformly with polyimide at a mass ratio of 1:5:2 to obtain modified mica powder. The additives were selected from diluents and thixotropic agents. The diluent was xylene, and the thixotropic agent was polyamide wax micropowder.

[0029] The preparation method of the ultra-high solids water-based epoxy anti-corrosion marine coating in this embodiment includes the following steps: (1) According to the weight ratio of component A, add dispersant, modified graphene, modified mica powder and anti-rust pigment to water in sequence, stir evenly, add water-based epoxy emulsion, defoamer and leveling agent, mix evenly to obtain component A; (2) According to the weight ratio of component B, add the anti-flash rust agent and additives to water, stir evenly, add water-based epoxy curing agent, mix evenly, and obtain component B; (3) Mix components A and B according to their weight ratio and stir until homogeneous to obtain an ultra-high solids water-based epoxy anti-corrosion marine coating.

[0030] Example 3 The ultra-high solids water-based epoxy anti-corrosion marine coating of this embodiment includes the following components A and B, with the proportions of each component being by weight: Component A includes: 55 parts of waterborne epoxy emulsion; 10 parts of modified graphene; 7 parts of modified mica powder; 8 parts of anti-rust pigment; 1.2 parts of dispersant; 0.6 parts of defoamer; 3 parts of leveling agent; and 21 parts of water. Component B comprises: 40 parts water-based epoxy curing agent; 1.2 parts flash rust inhibitor; 8 parts additives; and 20 parts water. The mass ratio of component A to component B is 3:1.

[0031] Aqueous epoxy emulsions are prepared as follows: Polyethylene glycol, after vacuum dehydration at 100–110°C, is cooled to 50–60°C. Toluene diisocyanate and dibutyltin dilaurate catalyst are added. Under nitrogen protection, the mixture is stirred and heated to 75–85°C for 1.5–2.5 hours. The temperature is then lowered to 60–70°C, and 2,2-dimethylolpropionic acid is added in batches. The mixture is then heated to 70–80°C and reacted for another 2–3 hours until the isocyanate content reaches a predetermined value, thus obtaining a carboxyl-containing emulsion with side chains. The isocyanate-terminated polyurethane prepolymer was prepared by cooling the carboxyl-containing polyurethane prepolymer to 30-50°C, adding epoxy resin, mixing thoroughly under stirring, and reacting at 30-60°C for 1-3 hours to complete the composite reaction of polyurethane prepolymer and epoxy resin, thus obtaining an aqueous epoxy emulsion intermediate. The mass ratio of toluene diisocyanate, polyethylene glycol, and 2,2-dimethylolpropionic acid was 2:5:1; the mass ratio of carboxyl-containing polyurethane prepolymer to epoxy resin was 3:5.

[0032] Graphene oxide and carbon fiber were uniformly mixed at a mass ratio of 1:5, and carbon fiber modified graphene was obtained by surface composite modification.

[0033] Sericite was dispersed in a solvent, and γ-aminopropyltriethoxysilane was added. The mixture was stirred at 40–60 °C for 2–4 h to modify the silane surface of the sericite. After separation and drying, surface-modified sericite was obtained. The modified sericite was then mixed uniformly with polyimide at a mass ratio of 1:8:1 to obtain modified mica powder. The additives were selected from diluents and thixotropic agents. The diluent was xylene, and the thixotropic agent was polyamide wax micropowder.

[0034] The preparation method of the ultra-high solids water-based epoxy anti-corrosion marine coating in this embodiment includes the following steps: (1) According to the weight ratio of component A, add dispersant, modified graphene, modified mica powder and anti-rust pigment to water in sequence, stir evenly, add water-based epoxy emulsion, defoamer and leveling agent, mix evenly to obtain component A; (2) According to the weight ratio of component B, add the anti-flash rust agent and additives to water, stir evenly, add water-based epoxy curing agent, mix evenly, and obtain component B; (3) Mix components A and B according to their weight ratio and stir until homogeneous to obtain an ultra-high solids water-based epoxy anti-corrosion marine coating.

[0035] Example 4 The ultra-high solids water-based epoxy anti-corrosion marine coating of this embodiment includes the following components A and B, with the proportions of each component being by weight: Component A includes: 60 parts of waterborne epoxy emulsion; 12 parts of modified graphene; 10 parts of modified mica powder; 12 parts of anti-rust pigment; 1.5 parts of dispersant; 0.6 parts of defoamer; 3 parts of leveling agent; and 23 parts of water. Component B comprises: 45 parts water-based epoxy curing agent; 1.4 parts flash rust inhibitor; 10 parts additives; and 20 parts water. The mass ratio of component A to component B is 3:1.

[0036] The aqueous epoxy emulsion of this embodiment is prepared by the following method: Polyethylene glycol, after vacuum dehydration treatment at 100–110°C, is cooled to 50–60°C, toluene diisocyanate and the catalyst dibutyltin dilaurate are added, and the mixture is stirred and heated to 75–85°C under nitrogen protection for 1.5–2.5 hours. Then, the temperature is lowered to 60–70°C, and 2,2-dimethylolpropionic acid is added in batches. The mixture is then heated to 70–80°C and the reaction continues for 2–3 hours until the isocyanate content of the system reaches a predetermined value, thus obtaining a side-chain containing… Carboxyl-terminated isocyanate-capped polyurethane prepolymer; the carboxyl-containing polyurethane prepolymer prepared above is cooled to 30-50℃, epoxy resin is added, and the mixture is thoroughly mixed under stirring. The mixture is then kept at 30-60℃ for 1-3 hours to complete the composite reaction of the polyurethane prepolymer and epoxy resin, thus obtaining an aqueous epoxy emulsion intermediate; the mass ratio of toluene diisocyanate, polyethylene glycol, and 2,2-dimethylolpropionic acid is 3:4:1; the mass ratio of carboxyl-containing polyurethane prepolymer to epoxy resin is 2.5:7.

[0037] Graphene oxide and carbon fiber were uniformly mixed at a mass ratio of 1:4, and carbon fiber modified graphene was obtained by surface composite modification.

[0038] Sericite was dispersed in a solvent, and γ-aminopropyltriethoxysilane was added. The mixture was stirred at 40–60 °C for 2–4 h to modify the silane surface of the sericite. After separation and drying, surface-modified sericite was obtained. The modified sericite was then mixed uniformly with polyimide at a mass ratio of 1:10:1 to obtain modified mica powder. The auxiliary agents were selected from diluents and thixotropic agents. The diluent was xylene, and the thixotropic agent was polyamide wax micropowder.

[0039] The preparation method of the ultra-high solids water-based epoxy anti-corrosion marine coating in this embodiment includes the following steps: (1) According to the weight ratio of component A, add dispersant, modified graphene, modified mica powder and anti-rust pigment to water in sequence, stir evenly, add water-based epoxy emulsion, defoamer and leveling agent, mix evenly to obtain component A; (2) According to the weight ratio of component B, add the anti-flash rust agent and additives to water, stir evenly, add water-based epoxy curing agent, mix evenly, and obtain component B; (3) Mix components A and B according to their weight ratio and stir until homogeneous to obtain an ultra-high solids water-based epoxy anti-corrosion marine coating.

[0040] Example 5 The ultra-high solids water-based epoxy anti-corrosion marine coating of this embodiment includes the following components A and B, each component being expressed in parts by weight: Component A includes: 70 parts of waterborne epoxy emulsion; 15 parts of modified graphene; 12 parts of modified mica powder; 15 parts of anti-rust pigment; 2 parts of dispersant; 0.8 parts of defoamer; 4 parts of leveling agent; and 25 parts of water. Component B comprises: 50 parts water-based epoxy curing agent; 1.6 parts flash rust inhibitor; 12 parts additives; and 25 parts water. The mass ratio of component A to component B is 3:2.

[0041] Aqueous epoxy emulsions are prepared as follows: Polyethylene glycol, after vacuum dehydration at 100–110°C, is cooled to 50–60°C. Toluene diisocyanate and dibutyltin dilaurate catalyst are added. Under nitrogen protection, the mixture is stirred and heated to 75–85°C for 1.5–2.5 hours. The temperature is then lowered to 60–70°C, and 2,2-dimethylolpropionic acid is added in batches. The mixture is then heated to 70–80°C and reacted for another 2–3 hours until the isocyanate content reaches a predetermined value, thus obtaining a carboxyl-containing emulsion with side chains. The isocyanate-terminated polyurethane prepolymer was prepared by cooling the carboxyl-containing polyurethane prepolymer to 30-50°C, adding epoxy resin, mixing thoroughly under stirring, and reacting at 30-60°C for 1-3 hours to complete the composite reaction of polyurethane prepolymer and epoxy resin, thus obtaining an aqueous epoxy emulsion intermediate. The mass ratio of toluene diisocyanate, polyethylene glycol, and 2,2-dimethylolpropionic acid was 3:5:1; the mass ratio of carboxyl-containing polyurethane prepolymer to epoxy resin was 3:11.

[0042] Graphene oxide and carbon fiber were uniformly mixed at a mass ratio of 2:5, and carbon fiber modified graphene was obtained by surface composite modification.

[0043] Sericite was dispersed in a solvent, and γ-aminopropyltriethoxysilane was added. The mixture was stirred at 40–60 °C for 2–4 h to modify the silane surface of the sericite. After separation and drying, surface-modified sericite was obtained. The modified sericite was then mixed uniformly with polyimide at a mass ratio of 2:11:3 to obtain modified mica powder. The auxiliary agents were selected from diluents and thixotropic agents. The diluent was xylene, and the thixotropic agent was polyamide wax micropowder.

[0044] The preparation method of the ultra-high solids water-based epoxy anti-corrosion marine coating in this embodiment includes the following steps: (1) According to the weight ratio of component A, add dispersant, modified graphene, modified mica powder and anti-rust pigment to water in sequence, stir evenly, add water-based epoxy emulsion, defoamer and leveling agent, mix evenly to obtain component A; (2) According to the weight ratio of component B, add the anti-flash rust agent and additives to water, stir evenly, add water-based epoxy curing agent, mix evenly, and obtain component B; (3) Mix components A and B according to their weight ratio and stir until homogeneous to obtain an ultra-high solids water-based epoxy anti-corrosion marine coating.

[0045] Comparative Example 1 Same as Example 1, except that no modified graphene was added.

[0046] Comparative Example 2 Same as Example 1, except that the modified graphene is replaced with ordinary graphene oxide.

[0047] Comparative Example 3 Same as Example 1, except that no modified mica powder was added.

[0048] Comparative Example 4 Same as Example 1, except that no carboxyl-containing polyurethane prepolymer was added to the waterborne epoxy emulsion.

[0049] Table 1 Performance Test Results

[0050] The analysis of the salt spray durability and solids content data tables above is as follows: The salt spray durability values ​​of Examples 1 to 5 are all between 1254 and 1362, with Example 1 exhibiting the best salt spray durability performance, reaching 1362. Simultaneously, the solids content of Examples 1 to 5 remains between 88% and 90%, indicating a relatively high level and good stability. In contrast, Comparative Examples 1 to 4 have salt spray durability values ​​below 1200, specifically 1185, 1174, 1132, and 1170 respectively, significantly lower than the Example group; the corresponding solids content is only 60% to 70%, far lower than the solids content of the Example group. In summary, there is a positive correlation between solids content and salt spray durability performance. Higher solids content helps improve the salt spray durability of the product. Compared to the Comparative Example group, the Example group shows a significant advantage in both salt spray durability and solids content.

[0051] The above description is merely an exemplary embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A water-based epoxy anti-corrosion marine coating with ultra-high solids content, characterized in that, Includes component A and component B, with each component's quantity expressed in parts by weight, as detailed below: Component A includes: 40-70 parts of waterborne epoxy emulsion; 8-15 parts of modified graphene; 5-12 parts of modified mica powder; 6-15 parts of anti-rust pigment; 0.5-2 parts of dispersant; 0.5-0.8 parts of defoamer; 2-4 parts of leveling agent; and 20-25 parts of water. Component B includes: 35-50 parts of water-based epoxy curing agent; 0.8-1.6 parts of flash rust inhibitor; 7-12 parts of additives; and 10-25 parts of water. The mass ratio of component A to component B is 1~3:1~2. The aqueous epoxy emulsion is prepared by the following method: firstly, a carboxyl-containing polyurethane prepolymer is prepared using toluene diisocyanate, polyethylene glycol and 2,2-dimethylolpropionic acid as raw materials; then, the carboxyl-containing polyurethane prepolymer is compounded with epoxy resin to obtain the emulsion. The modified graphene is prepared by mixing graphene oxide and carbon fiber and then performing surface composite modification to obtain carbon fiber modified graphene. The modified mica powder is prepared by reacting sericite with γ-aminopropyltriethoxysilane and then mixing it with polyimide.

2. The ultra-high solids water-based epoxy anti-corrosion marine coating according to claim 1, characterized in that, The mass ratio of toluene diisocyanate, polyethylene glycol, and 2,2-dimethylolpropionic acid is 1~3:2~5:

1.

3. The ultra-high solids water-based epoxy anti-corrosion marine coating according to claim 1, characterized in that, The mass ratio of the carboxyl-containing polyurethane prepolymer to the epoxy resin is 1.2~3:5~11.

4. The ultra-high solids water-based epoxy anti-corrosion marine coating according to claim 1, characterized in that, The mass ratio of γ-aminopropyltriethoxysilane, sericite, and polyimide is 1~2:5~11:1~3.

5. The ultra-high solids water-based epoxy anti-corrosion marine coating according to claim 1, characterized in that, The mass ratio of carbon fiber to graphene oxide is 1~2:3~5.

6. The ultra-high solids water-based epoxy anti-corrosion marine coating according to claim 1, characterized in that, The additive is selected from at least one of diluents, thixotropic agents, or antisettling agents.

7. The ultra-high solids water-based epoxy anti-corrosion marine coating according to claim 6, characterized in that, The diluent is selected from at least one of xylene, n-butanol, ethyl acetate, butyl acetate, or tetrahydrofuran; the thixotropic agent is polyamide wax powder or fumed silica.

8. The method for preparing the ultra-high solids water-based epoxy anti-corrosion marine coating according to any one of claims 1-7, characterized in that, Includes the following steps: (1) According to the weight ratio of component A, add dispersant, modified graphene, modified mica powder and anti-rust pigment to water in sequence, stir evenly, add water-based epoxy emulsion, defoamer and leveling agent, mix evenly to obtain component A; (2) According to the weight ratio of component B, add the anti-flash rust agent and additives to water, stir evenly, add water-based epoxy curing agent, mix evenly, and obtain component B; (3) Mix components A and B according to their weight ratio and stir until homogeneous to obtain an ultra-high solids water-based epoxy anti-corrosion marine coating.

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