Special nano-powder coating for anticorrosion of super-long ship, preparation method and application

Abstract

The application discloses a kind of ship super-long anticorrosion special nano powder coating, preparation method and application, belong to ship heavy anticorrosion material technical field.The preparation method of the ship super-long anticorrosion special nano powder coating is as follows: epoxy resin, graphene modified epoxy resin, core-shell structure ZnO@SiO2, modified 2,5-dimercapto-1,3,4-thiadiazole, borosilicate glass powder, flaky boron nitride, silane coupling agent modified silica, phenolic amine curing agent, 2-ethyl-4-methylimidazole, fumed silica, defoaming agent, ultraviolet absorber, high-temperature pigment are put into stirrer and stirred for 20-30min, then melt extrusion is carried out through double screw extruder, the extrusion temperature is 90-110 DEG C, grinds and sieves, and the ship super-long anticorrosion special nano powder coating is obtained.The coating prepared by the application has good anticorrosion performance and can be applied in the field of ship metal surface corrosion protection.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of marine heavy-duty anticorrosive materials, and more particularly relates to a special nano-powder coating for super-long anticorrosion of a ship, a preparation method and application. BACKGROUND

[0002] The ship is operated in the marine environment for a long time, which is an extreme corrosive environment with high salt and high pressure. The underwater hull, ballast tank, propeller and other structures of the ship are seriously damaged. However, the existing epoxy zinc-rich coating is prone to interfacial peeling under the synergistic corrosion of deep-sea high pressure and biological adhesion, and cannot meet the anticorrosion requirements of the ship. In addition, the conventional plasma spraying technology has a large temperature gradient, which can cause the thermal degradation rate of the epoxy resin to be greater than 30%, and seriously affects the performance and quality of the coating. Therefore, how to avoid this phenomenon is the key to solving the problem. For example, Chinese Patent CN115637085A discloses a water-based inorganic zinc-rich anticorrosive coating and a preparation method thereof, which comprises components and the weight fractions of each component are as follows: potassium silicate 5-15 parts; silica sol 10-30 parts; gamma-glycidoxypropyltrimethoxysilane 5-10 parts; silicone-acrylate emulsion 20-40 parts; modified zinc powder 20-40 parts; curing agent 1-5 parts; thickening agent 0.5-1.5 parts. The anticorrosive coating disclosed in the application uses modified zinc powder instead of ordinary zinc powder in the preparation of raw materials, so that the coating has better corrosion resistance and water resistance. However, the anticorrosive performance in the marine environment still needs to be improved. SUMMARY

[0003] Technical problems to be solved

[0004] In view of the deficiencies of the prior art, the present application provides a special nano-powder coating for super-long anticorrosion of a ship, a preparation method and application. The coating prepared by the present application has good anticorrosive performance and can be applied in the field of anticorrosion of ship metal surfaces.

[0005] Technical scheme

[0006] In order to solve the above problems, the technical scheme adopted by the present application is as follows: a special nano-powder coating for super-long anticorrosion of a ship, comprising the following weight components: 35-45 parts by weight of epoxy resin, 1-3 parts by weight of graphene modified epoxy resin, 8-12 parts by weight of core-shell structure ZnO@SiO2, 3-5 parts by weight of modified 2,5-dimercapto-1,3,4-thiadiazole, 4-6 parts by weight of borosilicate glass powder, 2-4 parts by weight of flaky boron nitride, 3-5 parts by weight of silane coupling agent modified silica, 2-4 parts by weight of phenolic amine curing agent, 2-3 parts by weight of 2-ethyl-4-methylimidazole, 1-2 parts by weight of fumed silica, 0.2-0.3 parts by weight of defoaming agent, 0.3-0.5 parts by weight of ultraviolet absorber, and 0.5-1 parts by weight of high-temperature pigment.

[0007] Further, the preparation method of the graphene modified epoxy resin is:

[0008] Step one: 0.96-1 g of graphene oxide is added to 230-250 mL of deionized water, ultrasonic treatment for 1-2 h, then 9.6-10 g of 2,5-diaminopyridine, 2-3 mL of 25% ammonia water is added, mixed uniformly, stirred at 80-90℃ for 3-5 h, after the reaction is completed, cooled to room temperature, washed and dried to obtain intermediate 1;

[0009] Step two: 0.75-0.8 g of intermediate 1 is added to 200-220 mL of deionized water, ultrasonic treatment for 1-2 h, then 7.5-8 g of ascorbic acid is added, stirred in water bath at 75-85℃, condensation reflux, reaction for 8-10 h, after the reaction is completed, suction filtration, washing, freeze-drying at-40℃ to-50℃ for 24-28 h to obtain intermediate 2;

[0010] Step three: 0.5-0.6 g of intermediate 2 is added to 50-60 mL of ethanol, ultrasonic treatment for 30-60 min, then 65-75 g of epoxy resin is added, stirred in water bath at 70-80℃ for 30-40 min, then 4.2-4.5 g of diethyl toluene diamine curing agent is added, continue to stir in water bath for 30-35 min, after the reaction is completed, remove the solvent by rotary evaporation, vacuum drying to obtain graphene modified epoxy resin.

[0011] Further, the preparation method of the core-shell structure ZnO@SiO2 is: 10-15 mL of deionized water and 30-35 mL of ethanol are added to the reactor, mixed uniformly, then 1.05-1.1 g of nano zinc oxide, 3.2-3.4 g of tetraethyl orthosilicate are added, ultrasonic treatment for 15-20 min, then 25% ammonia water is added to adjust the pH to 9-12, stirred at room temperature for 4-6 h, after the reaction is completed, centrifuged, washed and dried to obtain the core-shell structure ZnO@SiO2.

[0012] Further, the thickness of the SiO2 coating layer in the core-shell structure ZnO@SiO2 is 8-10 nm.

[0013] Further, the preparation method of the modified 2,5-dimercapto-1,3,4-thiadiazole is:

[0014] S1: 2.3-2.4 g of 2,5-dimercapto-1,3,4-thiadiazole, 3.5-3.6 g of anhydrous sodium carbonate were added to 50-70 mL of deionized water, stirred uniformly, then 2.9-3 g of chloroacetic acid was added dropwise, refluxed at 90-100°C for 4-8 h, after the reaction was completed, cooled to room temperature, slowly added to it concentrated hydrochloric acid to adjust the pH to 2-3, to obtain a precipitate, filtered, washed and dried, purified to obtain intermediate 3;

[0015] S2: Under the protection of nitrogen gas, 1.6-1.7 g of intermediate 3, 0.02-0.03 g of triethylamine were added to 40-50 mL of N,N-dimethylformamide solvent, mixed uniformly, then 2.4-2.5 g of 3-(perfluoro-n-octyl)-1,2-epoxypropane was added dropwise, stirred at 70-80°C for 18-24 h, after the reaction was completed, washed and dried to obtain modified 2,5-dimercapto-1,3,4-thiadiazole.

[0016] Further, the preparation method of the silane coupling agent modified silica is: 1.5-1.6 g of nano-silica is added to 30-35 mL of anhydrous ethanol solvent, stirred uniformly, then 0.2-0.3 g of γ-glycidyl ether propyl trimethoxysilane is slowly added dropwise, and the condensation reflux reaction is carried out at 60-70°C for 3-5 h, after the reaction is completed, washed, suction filtered, dried to obtain the silane coupling agent modified silica.

[0017] Further, the preparation method of the ship super-long corrosion-resistant special nano-powder coating is: epoxy resin, graphene modified epoxy resin, core-shell structure ZnO@SiO2, modified 2,5-dimercapto-1,3,4-thiadiazole, borosilicate glass powder, flaky boron nitride, silane coupling agent modified silica, phenolic amine curing agent, 2-ethyl-4-methyl imidazole, fumed silica, defoamer, ultraviolet absorber, high temperature pigment are put into a stirrer and stirred for 20-30 min, then melt extruded through a twin-screw extruder, the extrusion temperature is 90-110°C, ground and sieved to obtain the ship super-long corrosion-resistant special nano-powder coating.

[0018] Further, the ship super-long corrosion-resistant special nano-powder coating is applied in the field of ship metal surface corrosion prevention.

[0019] In the above steps, the special nano-powder coating for ultra-long-lasting anti-corrosion of ships is applied to the field of anti-corrosion of ship metal surfaces through plasma hot-melt spraying process. This process consists of three stages: preheating the substrate to 120-150℃ using a low-temperature plasma arc (power 20kW, Ar gas); melting the powder with high-temperature pulsed plasma (power 50kW, N2 / H2=7:3), with an instantaneous temperature of 1800-2000℃ but an action time <5ms (resin thermal weight loss <5%); and residual heat-triggered curing (maintaining 160℃ for 15min). The coating surface obtained by this process is a continuous inorganic glass phase layer (thickness 5-8µm), with an intermediate layer of graphene-epoxy / inorganic hybrid structure (porosity <0.8%), and the interface region forming Fe-O-Si chemical bonds with the substrate surface.

[0020] Beneficial technical effects

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] Grafting graphene oxide onto epoxy resin via an amine grafting reaction allows the graphene to be uniformly distributed in the coating as a monolayer, improving compatibility with the epoxy resin and reducing the coating's conductivity. Furthermore, the graphene-modified epoxy resin provides a strong and tough matrix, which, together with the parallel stacking of flake-like boron nitride and the highly hydrophobic modified 2,5-dimercapto-1,3,4-thiadiazole, forms a physical barrier. ZnO@SiO2 releases Zn at the damaged areas of the coating. 2+ The formation of a passivation film provides chemical passivation, while the glass phase cuts off electron channels to achieve electrochemical inhibition, forming a triple protection system that combines physical barriers, chemical passivation, and electrochemical inhibition, effectively improving the anti-corrosion performance of the coating. Furthermore, the plasma hot melt spraying process can achieve a metallurgical-chemical composite bond between the coating and the metal substrate, resolving the process contradiction between low-temperature curing of epoxy resin and high-temperature plasma processing. Attached Figure Description

[0023] Figure 1 It is a reactive synthetic formula for modified 2,5-dimercapto-1,3,4-thiadiazole. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] To better understand the above technical solutions, the following will provide a detailed description of the technical solutions in conjunction with the accompanying drawings and specific embodiments.

[0026] The reagents used in the following specific embodiments are analytical pure, and the like:

[0027] Graphene oxide: flake diameter is 3 um, thickness is ≤3 nm, and the manufacturer is Suzhou Carbon Abundant Graphene Technology Co., Ltd.;

[0028] Epoxy resin: grade E51, industrial grade, and the manufacturer is Nantong Xingchen Synthetic Material Co., Ltd.;

[0029] Phenolic amine curing agent: grade T-31, industrial grade, and the manufacturer is Guangzhou Carbonhua New Material Co., Ltd.;

[0030] Nano-zinc oxide: diameter is 50 nm, and the manufacturer is Shanghai Pantian Powder Material Co., Ltd.;

[0031] Borosilicate glass powder: softening point is 600°C, and the manufacturer is Anmi Micro-nano New Material (Guangzhou) Co., Ltd.;

[0032] Scaly boron nitride: single crystal thickness is 500 um, and the manufacturer is Shandong Jingyi New Material Co., Ltd.;

[0033] Fumed silica: the manufacturer is Cabot Corporation;

[0034] Defoaming agent: grade BYK-066N, and the manufacturer is Guangzhou Jintu Science and Technology Co., Ltd.;

[0035] Ultraviolet absorber: grade Tinuvin 384, and the manufacturer is Guangzhou Sichuangyuan Chemical Co., Ltd.

[0036] Example 1

[0037] The embodiment provides a special nano-powder coating for ship super-long corrosion prevention, and a preparation method thereof specifically comprises the following steps:

[0038] (1) 0.96 g of graphene oxide is added to 230 mL of deionized water, ultrasonic treatment is performed for 1 h, then 9.6 g of 2,5-diaminopyridine and 2 mL of 25% ammonia water are added thereto, uniform mixing is performed, stirring is performed at 80°C for 3 h, after the reaction is completed, cooling is performed to room temperature, washing and drying are performed, and an intermediate 1 is obtained;

[0039] (2) 0.75 g of the intermediate 1 is added to 200 mL of deionized water, ultrasonic treatment is performed for 1 h, then 7.5 g of ascorbic acid is added thereto, water bath stirring is performed at 75°C, condensation reflux is performed, reaction is performed for 8 h, after the reaction is completed, suction filtration is performed, washing is performed, freezing drying is performed at-40°C for 24 h, and an intermediate 2 is obtained;

[0040] (3) 0.5 g of intermediate 2 was added to 50 mL of ethanol, and ultrasonic treatment was performed for 30 min, then 65 g of epoxy resin was added, and stirring was performed in a water bath at 70°C for 30 min, then 4.2 g of diethyltoluene diamine curing agent was added, and stirring was continued in a water bath for 30 min, after the reaction was completed, the solvent was removed by rotary evaporation, and vacuum drying was performed, to obtain a graphene modified epoxy resin;

[0041] (4) 10 mL of deionized water and 30 mL of ethanol were added to the reactor, and mixed uniformly, then 1.05 g of nano zinc oxide and 3.2 g of tetraethyl orthosilicate were added, and ultrasonic treatment was performed for 15 min, then ammonia water with a concentration of 25% was added to adjust the pH to 9, and stirring was performed at room temperature for 4 h, after the reaction was completed, centrifugation, washing and drying were performed, to obtain a core-shell structure ZnO@SiO2;

[0042] (5) 2.3 g of 2,5-dimercapto-1,3,4-thiadiazole and 3.5 g of anhydrous sodium carbonate were added to 50 mL of deionized water, and stirred uniformly, then 2.9 g of chloroacetic acid was added dropwise, and reflux reaction was performed at 90°C for 4 h, after the reaction was completed, the temperature was cooled to room temperature, concentrated hydrochloric acid was slowly added to adjust the pH to 2, to obtain a precipitate, which was filtered, washed and dried, and purified, to obtain intermediate 3;

[0043] (6) Under the protection of nitrogen gas, 1.6 g of intermediate 3 and 0.02 g of triethylamine were added to 40 mL of N,N-dimethylformamide solvent, and mixed uniformly, then 2.4 g of 3-(perfluoro-n-octyl)-1,2-epoxypropane was added dropwise, and stirring reaction was performed at 70°C for 18 h, after the reaction was completed, washing and drying were performed, to obtain modified 2,5-dimercapto-1,3,4-thiadiazole, as shown in Figure 1 ;

[0044] (7) 1.5 g of nano silicon dioxide was added to 30 mL of anhydrous ethanol solvent, and stirred uniformly, then 0.2 g of γ-glycidyl ether propyltrimethoxysilane was slowly added dropwise, and condensation reflux reaction was performed at 60°C for 3 h, after the reaction was completed, washing, suction filtration and drying were performed, to obtain silane coupling agent modified silicon dioxide;

[0045] (8) 35 parts by weight of epoxy resin, 1 part by weight of graphene modified epoxy resin, 8 parts by weight of core-shell structure ZnO@SiO2, 3 parts by weight of modified 2,5-dimercapto-1,3,4-thiadiazole, 4 parts by weight of borosilicate glass powder, 2 parts by weight of flaky boron nitride, 3 parts by weight of silane coupling agent modified silicon dioxide, 2 parts by weight of phenolic amine curing agent, 2 parts by weight of 2-ethyl-4-methylimidazole, 1 part by weight of fumed silica, 0.2 parts by weight of defoaming agent, 0.3 parts by weight of ultraviolet absorber, 0.5 parts by weight of high temperature pigment are put into a blender and stirred for 20 min, then melt extruded through a twin-screw extruder, the extrusion temperature is 90℃, ground and sieved to obtain a special nano-powder coating for ship super-long corrosion protection.

[0046] Example 2

[0047] The present embodiment provides a special nano-powder coating for ship super-long corrosion protection, and the preparation method specifically comprises the following steps:

[0048] (1) 1 g of graphene oxide is added to 250 mL of deionized water, ultrasonic treatment for 2 h, then 10 g of 2,5-diaminopyridine and 3 mL of 25% ammonia water are added and mixed uniformly, stirred at 90℃ for 5 h, after the reaction is completed, cool to room temperature, wash and dry to obtain intermediate 1;

[0049] (2) 0.8 g of intermediate 1 is added to 220 mL of deionized water, ultrasonic treatment for 2 h, then 8 g of ascorbic acid is added, stirred in water bath at 85℃, condensation reflux, reaction for 10 h, after the reaction is completed, suction filtration, washing, freeze-drying at-50℃ for 28 h to obtain intermediate 2;

[0050] (3) 0.6 g of intermediate 2 is added to 60 mL of ethanol, ultrasonic treatment for 60 min, then 75 g of epoxy resin is added, stirred in water bath at 80℃ for 40 min, then 4.5 g of diethyltoluene diamine curing agent is added, continue to stir in water bath for 35 min, after the reaction is completed, remove the solvent by rotary evaporation, vacuum drying to obtain graphene modified epoxy resin;

[0051] (4) 15 mL of deionized water and 35 mL of ethanol are added to the reactor and mixed uniformly, then 1.1 g of nano-zinc oxide and 3.4 g of tetraethyl orthosilicate are added, ultrasonic treatment for 20 min, then the pH is adjusted to 12 by adding 25% ammonia water, stirred at room temperature for 6 h, after the reaction is completed, centrifuged, washed and dried to obtain core-shell structure ZnO@SiO2;

[0052] (5) 2.4 g of 2,5-dimercapto-1,3,4-thiadiazole, 3.6 g of anhydrous sodium carbonate were added into 70 mL of deionized water, stirred uniformly, then 3 g of chloroacetic acid was added dropwise, refluxed at 100°C for 8 h, after the reaction was completed, cooled to room temperature, slowly added concentrated hydrochloric acid to adjust the pH to 3, to obtain a precipitate, filtered, washed and dried, purified to obtain intermediate 3;

[0053] (6) Under the protection of nitrogen gas, 1.7 g of intermediate 3, 0.03 g of triethylamine were added into 50 mL of N,N-dimethylformamide solvent, mixed uniformly, then 2.5 g of 3-(perfluoro-n-octyl)-1,2-epoxypropane was added dropwise, stirred at 80°C for 24 h, after the reaction was completed, washed and dried to obtain modified 2,5-dimercapto-1,3,4-thiadiazole;

[0054] (7) 1.6 g of nano-silicon dioxide was added into 35 mL of anhydrous ethanol solvent, stirred uniformly, then 0.3 g of γ-glycidyl ether propyltrimethoxysilane was slowly added dropwise, condensed and refluxed at 70°C for 5 h, after the reaction was completed, washed, suction filtered, dried to obtain silane coupling agent modified silicon dioxide;

[0055] (8) 45 parts by weight of epoxy resin, 3 parts by weight of graphene modified epoxy resin, 12 parts by weight of core-shell structure ZnO@SiO2, 5 parts by weight of modified 2,5-dimercapto-1,3,4-thiadiazole, 6 parts by weight of borosilicate glass powder, 4 parts by weight of flaky boron nitride, 5 parts by weight of silane coupling agent modified silicon dioxide, 4 parts by weight of phenolic amine curing agent, 3 parts by weight of 2-ethyl-4-methylimidazole, 2 parts by weight of fumed silica, 0.3 parts by weight of defoaming agent, 0.5 parts by weight of ultraviolet absorber, 1 part by weight of high-temperature pigment were put into a stirrer and stirred for 30 min, then melt-extruded through a twin-screw extruder, the extrusion temperature was 110°C, ground and sieved to obtain a ship super-long anticorrosive special nano-powder coating.

[0056] Example 3

[0057] The present embodiment provides a ship super-long anticorrosive special nano-powder coating, and the preparation method specifically comprises the following steps:

[0058] (1) 0.98 g of graphene oxide was added into 240 mL of deionized water, ultrasonic treated for 1.5 h, then 9.8 g of 2,5-diaminopyridine, 2.5 mL of 25% ammonia water were added, mixed uniformly, stirred at 85°C for 4 h, after the reaction was completed, cooled to room temperature, washed and dried to obtain intermediate 1;

[0059] (2) 0.78 g of intermediate 1 was added to 210 mL of deionized water, ultrasonic treatment for 1.5 h, then 7.75 g of ascorbic acid was added, water bath stirring at 80°C, condensation reflux, reaction for 9 h, after the reaction, suction filtration, washing, freeze-drying at -45°C for 26 h to obtain intermediate 2;

[0060] (3) 0.55 g of intermediate 2 was added to 55 mL of ethanol, ultrasonic treatment for 45 min, then 70 g of epoxy resin was added, water bath stirring at 75°C for 35 min, then 4.35 g of diethyl toluene diamine curing agent was added, continue water bath stirring for 33 min, after the reaction, rotary evaporation to remove the solvent, vacuum drying to obtain graphene modified epoxy resin;

[0061] (4) 13 mL of deionized water and 32 mL of ethanol were added to the reactor, mixed uniformly, then 1.08 g of nano zinc oxide, 3.3 g of tetraethyl orthosilicate were added, ultrasonic treatment for 18 min, then 25% ammonia water was added to adjust the pH to 10, stirring at room temperature for 5 h, after the reaction, centrifugation, washing and drying to obtain core-shell structure ZnO@SiO2;

[0062] (5) 2.35 g of 2,5-dimercapto-1,3,4-thiadiazole, 3.55 g of anhydrous sodium carbonate were added to 60 mL of deionized water, stirred uniformly, then 2.95 g of chloroacetic acid was added dropwise, refluxed at 95°C for 6 h, after the reaction, cooled to room temperature, slowly added concentrated hydrochloric acid to adjust the pH to 2 to obtain precipitate, filtration, washing and drying, purification to obtain intermediate 3;

[0063] (6) Under the protection of nitrogen gas, 1.65 g of intermediate 3, 0.02 g of triethylamine were added to 45 mL of N,N-dimethylformamide solvent, mixed uniformly, then 2.45 g of 3-(perfluoro-n-octyl)-1,2-epoxypropane was added dropwise, stirred at 75°C for 21 h, after the reaction, washing and drying to obtain modified 2,5-dimercapto-1,3,4-thiadiazole;

[0064] (7) 1.55 g of nano silica was added to 32 mL of anhydrous ethanol solvent, stirred uniformly, then 0.25 g of γ-glycidoxypropyltrimethoxysilane was slowly added dropwise, condensation refluxed at 65°C for 4 h, after the reaction, washing, suction filtration, drying to obtain silane coupling agent modified silica;

[0065] (8) 40 parts by weight of epoxy resin, 2 parts by weight of graphene modified epoxy resin, 10 parts by weight of core-shell structure ZnO@SiO2, 4 parts by weight of modified 2,5-dimercapto-1,3,4-thiadiazole, 5 parts by weight of borosilicate glass powder, 3 parts by weight of flaky boron nitride, 4 parts by weight of silane coupling agent modified silicon dioxide, 3 parts by weight of phenolic amine curing agent, 2 parts by weight of 2-ethyl-4-methylimidazole, 1.5 parts by weight of fumed silica, 0.2 parts by weight of defoamer, 0.4 parts by weight of ultraviolet absorber, 0.8 parts by weight of high temperature pigment are put into a blender and stirred for 25 min, then melt extruded through a twin-screw extruder, the extrusion temperature is 100℃, ground and sieved to obtain a special nano-powder coating for ship super-long corrosion protection.

[0066] Example 4

[0067] The present embodiment provides a special nano-powder coating for ship super-long corrosion protection, and the preparation method specifically comprises the following steps:

[0068] (1) 0.97g of graphene oxide is added to 235mL of deionized water, ultrasonic treatment for 1h, then 9.7g of 2,5-diaminopyridine, 2.2mL of 25% ammonia water are added thereto, mixed uniformly, stirred at 82℃ for 3h, after the reaction is completed, cooled to room temperature, washed and dried to obtain intermediate 1;

[0069] (2) 0.76g of intermediate 1 is added to 205mL of deionized water, ultrasonic treatment for 1h, then 7.6g of ascorbic acid is added thereto, stirred in water bath at 78℃, condensation reflux, reaction for 8h, after the reaction is completed, suction filtration, washing, freeze-drying at-42℃ for 25h to obtain intermediate 2;

[0070] (3) 0.52g of intermediate 2 is added to 52mL of ethanol, ultrasonic treatment for 35min, then 68g of epoxy resin is added thereto, stirred in water bath at 72℃ for 32min, then 4.3g of diethyltoluene diamine curing agent is added thereto, continue to stir in water bath for 32min, after the reaction is completed, the solvent is removed by rotary evaporation, vacuum drying to obtain graphene modified epoxy resin;

[0071] (4) 11mL of deionized water and 32mL of ethanol are added to the reactor, mixed uniformly, then 1.06g of nano zinc oxide, 3.25g of tetraethyl orthosilicate are added thereto, ultrasonic treatment for 16min, then 25% ammonia water is added to adjust the pH to 10, stirred at room temperature for 4h, after the reaction is completed, centrifuged, washed and dried to obtain core-shell structure ZnO@SiO2;

[0072] (5) 2.32 g of 2,5-dimercapto-1,3,4-thiadiazole, 3.52 g of anhydrous sodium carbonate were added into 55 mL of deionized water, stirred uniformly, then 2.92 g of chloroacetic acid was added dropwise, refluxed at 92°C for 5 h, after the reaction was completed, cooled to room temperature, slowly added concentrated hydrochloric acid to adjust the pH to 2, to obtain a precipitate, filtered, washed and dried, purified to obtain intermediate 3;

[0073] (6) Under the protection of nitrogen gas, 1.62 g of intermediate 3, 0.02 g of triethylamine were added into 42 mL of N,N-dimethylformamide solvent, mixed uniformly, then 2.42 g of 3-(perfluoro-n-octyl)-1,2-epoxypropane was added dropwise, stirred at 72°C for 20 h, after the reaction was completed, washed and dried to obtain modified 2,5-dimercapto-1,3,4-thiadiazole;

[0074] (7) 1.52 g of nano-silicon dioxide was added into 32 mL of anhydrous ethanol solvent, stirred uniformly, then 0.22 g of γ-glycidyl ether propyltrimethoxysilane was slowly added dropwise, condensed and refluxed at 62°C for 3 h, after the reaction was completed, washed, suction filtered, and dried to obtain silane coupling agent modified silicon dioxide;

[0075] (8) 38 parts by weight of epoxy resin, 1 part by weight of graphene modified epoxy resin, 9 parts by weight of core-shell structured ZnO@SiO2, 3 parts by weight of modified 2,5-dimercapto-1,3,4-thiadiazole, 4 parts by weight of borosilicate glass powder, 3 parts by weight of flaky boron nitride, 4 parts by weight of silane coupling agent modified silicon dioxide, 3 parts by weight of phenolic amine curing agent, 2 parts by weight of 2-ethyl-4-methylimidazole, 1 part by weight of fumed silica, 0.2 parts by weight of defoaming agent, 0.4 parts by weight of ultraviolet absorber, 0.6 parts by weight of high-temperature pigment were put into a stirrer and stirred for 22 min, then melt-extruded through a twin-screw extruder, the extrusion temperature was 95°C, ground and sieved to obtain a ship super-long anticorrosive special nano-powder coating.

[0076] Example 5

[0077] The present embodiment provides a ship super-long anticorrosive special nano-powder coating, and the preparation method specifically comprises the following steps:

[0078] (1) 0.99 g of graphene oxide was added into 245 mL of deionized water, ultrasonic treated for 2 h, then 9.9 g of 2,5-diaminopyridine, 3 mL of 25% ammonia water were added, mixed uniformly, stirred at 88°C for 5 h, after the reaction was completed, cooled to room temperature, washed and dried to obtain intermediate 1;

[0079] (2) 0.79 g of intermediate 1 was added to 215 mL of deionized water, ultrasonic treatment for 2 h, then 7.9 g of ascorbic acid was added, water bath stirring at 82°C, condensation reflux, reaction for 10 h, after the reaction was completed, suction filtration, washing, freeze-drying at -48°C for 27 h to obtain intermediate 2;

[0080] (3) 0.58 g of intermediate 2 was added to 58 mL of ethanol, ultrasonic treatment for 50 min, then 72 g of epoxy resin was added, water bath stirring at 78°C for 38 min, then 4.4 g of diethyl toluene diamine curing agent was added, continue water bath stirring for 34 min, after the reaction was completed, rotary evaporation to remove the solvent, vacuum drying to obtain graphene modified epoxy resin;

[0081] (4) 14 mL of deionized water and 34 mL of ethanol were added to the reactor, mixed uniformly, then 1.09 g of nano zinc oxide, 3.35 g of tetraethyl orthosilicate were added, ultrasonic treatment for 19 min, then 25% ammonia water was added to adjust the pH to 11, stirring at room temperature for 6 h, after the reaction was completed, centrifugation, washing and drying to obtain core-shell structure ZnO@SiO2;

[0082] (5) 2.38 g of 2,5-dimercapto-1,3,4-thiadiazole, 3.58 g of anhydrous sodium carbonate were added to 65 mL of deionized water, stirred uniformly, then 2.98 g of chloroacetic acid was added dropwise, refluxed at 98°C for 7 h, after the reaction was completed, cooled to room temperature, slowly added to concentrated hydrochloric acid to adjust the pH to 3, to obtain the precipitate, filtration, washing and drying, purification to obtain intermediate 3;

[0083] (6) Under the protection of nitrogen gas, 1.68 g of intermediate 3, 0.03 g of triethylamine were added to 48 mL of N,N-dimethylformamide solvent, mixed uniformly, then 2.48 g of 3-(perfluoro-n-octyl)-1,2-epoxypropane was added dropwise, stirred at 78°C for 22 h, after the reaction was completed, washed and dried to obtain modified 2,5-dimercapto-1,3,4-thiadiazole;

[0084] (7) 1.58 g of nano silica was added to 34 mL of anhydrous ethanol solvent, stirred uniformly, then 0.28 g of γ-glycidyl ether propyltrimethoxysilane was slowly added dropwise, condensation refluxed at 68°C for 5 h, after the reaction was completed, washed, suction filtered, dried to obtain silane coupling agent modified silica;

[0085] (8) 42 parts by weight of epoxy resin, 2 parts by weight of graphene modified epoxy resin, 11 parts by weight of core-shell structured ZnO@SiO2, 4 parts by weight of modified 2,5-dimercapto-1,3,4-thiadiazole, 6 parts by weight of borosilicate glass powder, 3 parts by weight of flaky boron nitride, 5 parts by weight of silane coupling agent modified silica, 4 parts by weight of phenolic amine curing agent, 3 parts by weight of 2-ethyl-4-methylimidazole, 2 parts by weight of fumed silica, 0.3 parts by weight of defoaming agent, 0.4 parts by weight of ultraviolet absorber, and 0.9 parts by weight of high-temperature pigment were put into a stirrer and stirred for 28 min, then melt-extruded through a double-screw extruder, the extrusion temperature was 105°C, ground and sieved to obtain a special nano-powder coating for ship super-long corrosion protection.

[0086] Comparative Example 1

[0087] The special nano-powder coating for ship super-long corrosion protection of the present comparative example 1 and example 1 have basically the same proportion, the main difference is that the intermediate 3 is used instead of modified 2,5-dimercapto-1,3,4-thiadiazole.

[0088] Comparative Example 2

[0089] The special nano-powder coating for ship super-long corrosion protection of the present comparative example 2 and example 1 have basically the same proportion, the main difference is that no graphene modified epoxy resin is added, 3 parts by weight of graphene is used as raw material and mixed with other components, melt-extruded, ground and sieved to obtain a special nano-powder coating for ship super-long corrosion protection.

[0090] Performance test:

[0091] The special nano-powder coating for ship super-long corrosion protection prepared in examples 1-5 and comparative examples 1-2 was uniformly sprayed on the surface of cast iron parts by plasma hot melt spraying process to obtain standard test samples.

[0092] (1) Adhesion test: the adhesion of the standard test sample was tested according to the standard GB / T9286-2021. The test results are shown in Table 1.

[0093] Table 1: Adhesion test

[0094]

[0095] As can be seen from Table 1, the special nano-powder coating for ship super-long corrosion protection prepared in examples 1-5 has good adhesion.

[0096] (2) Anti-corrosion performance test: The anti-corrosion performance of the standard sample in artificial seawater was tested according to the standard GB / T9274-1988, the condition was 5% sodium chloride solution, the temperature was 40℃, and the time was 2000h; in addition, the standard sample was immersed in the simulated seawater solution for 14 days, and the EIS data was obtained by using an electrochemical workstation (P3000A) to evaluate the electrochemical corrosion resistance of the surface coating of the standard sample, the greater the charge transfer resistance, the better the anti-corrosion ability. The test results are shown in Table 2.

[0097] Table 2: Anti-corrosion performance test

[0098]

[0099] As can be seen from Table 2, the ship super-long anti-corrosion special nano-powder coating prepared in Examples 1-5 has good anti-corrosion performance.

[0100] It can be seen that, in Comparative Example 1, the intermediate 3 is used instead of the modified 2,5-dimercapto-1,3,4-thiadiazole, and the fluorocarbon chain with high hydrophobicity is missing, and the carboxylic acid on the intermediate 3 has strong polarity and is hydrophilic, so the compatibility in the non-polar epoxy resin system is poor, and aggregation is easy to occur at the interface between the coating and the substrate, which provides a channel for the corrosion medium, and will lead to the decrease of the adhesion and the anti-corrosion performance; in Comparative Example 2, graphene is directly added to be physically mixed with the epoxy resin system, the interface bonding is poor and the shielding structure is incomplete, which will lead to the increase of the conductivity of the coating and accelerate the electrochemical corrosion of the substrate, so the adhesion and the anti-corrosion performance of Comparative Example 2 decrease, and the electrochemical anti-corrosion performance is the worst.

[0101] It should be noted that in this document, the terms "comprising", "containing", or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a series of elements not only includes those elements, but also includes other elements not explicitly listed, or further includes elements inherent to such a process, method, article or device. Without more limitations, the element defined by the statement "comprising a" does not exclude the presence of additional identical elements in the process, method, article or device comprising the element.

[0102] The above examples are only used to illustrate the technical solutions of the present application, but not to limit it; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

[0103] Those skilled in the art should understand that the above description is only several specific embodiments of the present application, not all embodiments. It should be noted that many modifications and improvements can also be made by those of ordinary skill in the art, and all modifications and improvements that do not exceed the scope of the claims should be considered as the protection scope of the present application.

Claims

1. A special anticorrosive nanometer powder coating for super-long ships, characterized in that, Comprise the following weight components: 35-45 parts by weight of epoxy resin, 1-3 parts by weight of graphene modified epoxy resin, 8-12 parts by weight of core-shell structure ZnO@SiO2, 3-5 parts by weight of modified 2,5-dimercapto-1,3,4-thiadiazole, 4-6 parts by weight of borosilicate glass powder, 2-4 parts by weight of flaky boron nitride, 3-5 parts by weight of silane coupling agent modified silica, 2-4 parts by weight of phenolic amine curing agent, 2-3 parts by weight of 2-ethyl-4-methylimidazole, 1-2 parts by weight of fumed silica, 0.2-0.3 parts by weight of defoamer, 0.3-0.5 parts by weight of ultraviolet absorber, 0.5-1 parts by weight of high temperature pigment; The preparation method of the modified 2,5-dimercapto-1,3,4-thiadiazole is: S1: 2.3-2.4g of 2,5-dimercapto-1,3,4-thiadiazole, 3.5-3.6g of anhydrous sodium carbonate were added into 50-70mL of deionized water, stirred uniformly, then 2.9-3g of chloroacetic acid was added dropwise, refluxed at 90-100℃ for 4-8h, after the reaction was completed, cooled to room temperature, then concentrated hydrochloric acid was slowly added to adjust the pH to 2-3, to obtain a precipitate, filtered, washed and dried, purified to obtain intermediate 3; S2: 1.6-1.7g of intermediate 3, 0.02-0.03g of triethylamine were added into 40-50mL of N,N-dimethylformamide solvent, mixed uniformly, then 2.4-2.5g of 3-(perfluoro-n-octyl)-1,2-epoxypropane was added dropwise, stirred at 70-80℃ for 18-24h, after the reaction was completed, washed and dried to obtain modified 2,5-dimercapto-1,3,4-thiadiazole.

2. The special nano-powder coating for corrosion protection of overlength of ships according to claim 1, characterized in that, The preparation method of the graphene modified epoxy resin is: Step one: 0.96-1g of graphene oxide was added into 230-250mL of deionized water, ultrasonic treated for 1-2h, then 9.6-10g of 2,5-diaminopyridine, 2-3mL of 25% ammonia water were added, mixed uniformly, stirred at 80-90℃ for 3-5h, after the reaction was completed, cooled to room temperature, washed and dried to obtain intermediate 1; Step two: 0.75-0.8g of intermediate 1 was added into 200-220mL of deionized water, ultrasonic treated for 1-2h, then 7.5-8g of ascorbic acid was added, stirred in water bath at 75-85℃, condensed and refluxed, reacted for 8-10h, after the reaction was completed, suction filtered, washed, frozen and dried at-40℃ to-50℃ for 24-28h to obtain intermediate 2; Step three: 0.5-0.6g of intermediate 2 was added into 50-60mL of ethanol, and ultrasonic treatment was carried out for 30-60min, then 65-75g of epoxy resin was added, and water bath stirring was carried out at 70-80℃ for 30-40min, then 4.2-4.5g of diethyl toluene diamine curing agent was added, and water bath stirring was continued for 30-35min, after the reaction was completed, the solvent was removed by rotary evaporation, and vacuum drying was carried out, to obtain graphene modified epoxy resin.

3. The special nano-powder coating for corrosion protection of overlength of ships according to claim 1, characterized in that, The preparation method of the core-shell structure ZnO@SiO2 was as follows: 10-15mL of deionized water and 30-35mL of ethanol were added into a reactor, and mixed uniformly, then 1.05-1.1g of nano zinc oxide and 3.2-3.4g of tetraethyl orthosilicate were added, ultrasonic treatment was carried out for 15-20min, then ammonia water with a concentration of 25% was added to adjust the pH to 9-12, and stirring reaction was carried out at room temperature for 4-6h, after the reaction was completed, centrifugal washing and drying were carried out, to obtain the core-shell structure ZnO@SiO2.

4. The special nano-powder coating for corrosion protection of overlength of ships according to claim 3, characterized in that, The thickness of the SiO2 coating layer in the core-shell structure ZnO@SiO2 was 8-10nm.

5. The special nano-powder coating for corrosion protection of overlength of ships as claimed in claim 1 wherein, The preparation method of the silane coupling agent modified silica was as follows: 1.5-1.6g of nano silica was added into 30-35mL of anhydrous ethanol solvent, and stirred uniformly, then 0.2-0.3g of γ-glycidyl ether propyltrimethoxysilane was slowly added dropwise, and condensation reflux reaction was carried out at 60-70℃ for 3-5h, after the reaction was completed, washing, suction filtration and drying were carried out, to obtain the silane coupling agent modified silica.

6. A method of preparing a special anticorrosive nanometer powder coating for the super-long ship according to any one of claims 1-5, characterized in that, The preparation method of the special nano powder coating for ship super-long corrosion prevention was as follows: the epoxy resin, graphene modified epoxy resin, core-shell structure ZnO@SiO2, modified 2,5-dimercapto-1,3,4-thiadiazole, borosilicate glass powder, flaky boron nitride, silane coupling agent modified silica, phenolic amine curing agent, 2-ethyl-4-methyl imidazole, fumed silica, defoaming agent, ultraviolet absorber and high temperature pigment were put into a stirrer and stirred for 20-30min, then melt extrusion was carried out through a double screw extruder, the extrusion temperature was 90-110℃, and grinding and sieving were carried out, to obtain the special nano powder coating for ship super-long corrosion prevention.

7. Use of a special anticorrosive nanometric powder coating for the superlength of a marine vessel according to any one of claims 1-5, characterized in that, The special nano powder coating for ship super-long corrosion prevention was applied in the field of ship metal surface corrosion prevention.

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