High-corrosion-resistance coating and valve applying same
By using a composite coating of tetrafluoroethylene, nano-silica, indole corrosion resistant agent and carbon nanotube filler, the corrosion problem of valve materials under complex working conditions is solved, achieving high corrosion resistance and long-term stability, and improving the protective performance of valves.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- BIP PEROLO JIANGSU ENG LTD
- Filing Date
- 2026-03-24
- Publication Date
- 2026-05-15
AI Technical Summary
Existing valve materials are prone to localized passivation film damage in media containing chloride ions, hydrogen sulfide, etc., leading to pitting corrosion, crevice corrosion and stress corrosion cracking. Traditional coatings have weak adhesion and insufficient density, and cannot effectively resist corrosion under complex alternating working conditions.
Using tetrafluoroethylene as the film-forming matrix, nano-silica enhances adhesion, and indole corrosion resistant agent is prepared by combining Prussian blue with indole to form active defense. Carbon nanotube filler and graphene oxide form a stable three-dimensional reinforcing network, and high-temperature stabilizer is used to construct a multi-protection system.
It significantly improves the coating's adhesion, density, and resistance to pitting and stress corrosion cracking in harsh environments, enhances the coating's mechanical strength and long-term stability, and improves the valve's corrosion resistance.
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Figure SMS_1
Abstract
Description
Technical Field
[0001] This application relates to the field of coatings, and more particularly to a highly corrosion-resistant coating and a valve using the coating. Background Technology
[0002] Valves, as key control components in fluid transport systems, are widely used in chemical, petroleum, metallurgical, and marine engineering fields. They are often exposed to extreme corrosive media such as high concentrations of acids, alkalis, salts, or high temperatures and pressures for extended periods. These harsh operating conditions place extremely high demands on the corrosion resistance of valve materials.
[0003] Currently, the industry commonly uses stainless steel, nickel-based alloys, and other metallic materials to manufacture valve bodies, relying on their inherent passivation capabilities to resist corrosion. However, under the long-term action of specific media containing chloride ions, hydrogen sulfide, etc., the material surface is prone to localized passivation film damage, leading to pitting corrosion, crevice corrosion, and even stress corrosion cracking, resulting in valve sealing failure or structural damage, seriously affecting system safety and lifespan. To solve this problem, surface modification technologies such as electroplating and thermal spraying have been applied to valve protection. However, traditional plating or coatings often have limitations such as weak adhesion, insufficient density, or a mismatch between resistance to uniform corrosion and localized corrosion. Under complex alternating operating conditions, phenomena such as coating peeling and accelerated failure may still occur. Summary of the Invention
[0004] To improve the corrosion resistance of valves, this application provides a highly corrosion-resistant coating and a valve using the coating.
[0005] Firstly, this application provides a highly corrosion-resistant coating, which adopts the following technical solution: A highly corrosion-resistant coating comprises the following components in parts by weight: 70-90 parts of tetrafluoroethylene, 6-12 parts of nano-silica, 2-4 parts of high-temperature stabilizer, 4-8 parts of indole corrosion resistant agent, and 3-5 parts of carbon nanotube filler. The indole corrosion resistant agent includes Prussian blue and indole.
[0006] By adopting the above technical solution, tetrafluoroethylene, as the film-forming matrix, provides excellent chemical inertness and basic barrier. Nano-silica is uniformly dispersed in the system, enhancing the adhesion between the coating and the substrate, improving the coating's density and temperature resistance, and serving as a key reinforcing phase for the physical barrier. The indole corrosion inhibitor is prepared by combining Prussian blue and indole. As the core of active defense, Prussian blue can passivate the corrosion initiation point through ion exchange and electrochemical action, while indole molecules can adhere to the metal interface to form a monomolecular corrosion inhibitor film, playing a synergistic role in corrosion resistance and further improving the mechanical strength of the coating. The high-temperature stabilizer ensures the stability of the above composite system under high-temperature curing and application environments.
[0007] Preferably, the indole corrosion resistant agent is prepared by the following method: Potassium ferricyanide, hydrochloric acid, and water were mixed and added to N,N-dimethylformamide. After stirring, a potassium ferricyanide solution was obtained. The potassium ferricyanide solution was heated and aged, and the precipitate was collected by centrifugation, washed, and dried to obtain Prussian blue. Indole and Prussian blue were added to deionized water, and then ammonium persulfate solution was added. The mixture was stirred and reacted, then centrifuged, washed, and dried to obtain an indole corrosion resistant agent.
[0008] By adopting the above technical solution, Prussian blue particles are first obtained through aging. Then, under the initiation of ammonium persulfate, indole monomers react around the surface of Prussian blue, promoting the formation of chemical bonds between the two and obtaining structurally stable particles. This effectively reduces the premature loss of indole during practical use and synergistically improves corrosion resistance.
[0009] Preferably, the mass ratio of indole, Prussian blue and ammonium persulfate is 1:(0.85-0.95):1.7.
[0010] By adopting the above technical solution, the mass ratio of indole, Prussian blue and ammonium persulfate is preferably within the above range, so that the indole and Prussian blue achieve the best balance and synergistic density, and the prepared indole corrosion resistant agent has good stability.
[0011] Preferably, the carbon nanotube filler material includes superhydrophobic carbon nanotubes, graphene oxide, and fluorocarbon resin.
[0012] By adopting the above technical solution, carbon nanotube filler is used as a composite functional body. Superhydrophobic carbon nanotubes provide hydrophobicity and one-dimensional nano-reinforcement. With the addition of trace amounts of graphene oxide, the two-dimensional sheet structure can hinder the penetration of corrosive media over a larger area. Furthermore, it interweaves with carbon nanotubes to form a stable three-dimensional reinforcing network. Fluorocarbon resin encapsulates the hydrophobic carbon nanotubes and graphene oxide, reducing agglomeration in the coating. It also has good compatibility with tetrafluoroethylene, improving the interfacial bonding between the filler and the coating.
[0013] Preferably, the superhydrophobic carbon nanotubes are prepared by the following method: Water, acetic acid and anhydrous ethanol were mixed, and then perfluorodecyltriethoxysilane was added. After stirring, a silanol solution was obtained. Carbon nanotubes were mixed with ethanol, stirred and dispersed, and then added to the silanol solution. The mixture was heated and stirred to react. After the reaction, the mixture was filtered, washed and dried to obtain superhydrophobic carbon nanotubes.
[0014] By adopting the above technical solution, fluorosilane is grafted onto the surface of carbon nanotubes through a hydrolysis-condensation reaction. Acetic acid further catalyzes the hydrolysis of silane, which reacts with the groups on the surface of carbon nanotubes, endowing the carbon nanotubes with durable and stable superhydrophobic properties, and further improving the coating's impermeability and moisture resistance.
[0015] Preferably, the mass ratio of the carbon nanotubes to perfluorodecyltriethoxysilane is 1:(1.2-1.3).
[0016] By adopting the above technical solution, the mass ratio between carbon nanotubes and deperfluorodecyltriethoxysilane is preferably within the above range, so that the carbon nanotubes have sufficient fluorosilane monomers to fully and uniformly coat their surface, forming a complete monolayer with low surface energy, thereby obtaining the best hydrophobic effect.
[0017] Preferably, the carbon nanotube filler is prepared by the following method: Fluorocarbon resin, xylene, and butyl ester were mixed to obtain a fluorocarbon resin dispersion system. Superhydrophobic carbon nanotubes and graphene oxide were added to the fluorocarbon resin dispersion system, dispersed, and then milled to obtain carbon nanotube fillers.
[0018] By adopting the above technical solution, fluorocarbon resin is first made into a dispersion system, and then superhydrophobic carbon nanotubes and graphene oxide are added. After grinding, it can play an efficient dispersion role, so that the fluorocarbon resin can fully impregnate and coat the superhydrophobic carbon nanotubes and graphene oxide, reduce the re-agglomeration of superhydrophobic carbon nanotubes and graphene oxide, and improve the compatibility and binding force of nanomaterials in the system, further enhancing the stability of the prepared carbon nanotube filler.
[0019] Preferably, the mass ratio of the fluorocarbon resin, the superhydrophobic carbon nanotubes and the graphene oxide is 1:(0.25-0.35):0.05.
[0020] By adopting the above technical solution, and preferably within the above range the mass ratio of fluorocarbon resin, superhydrophobic carbon nanotubes and graphene oxide, a moderately thick and complete continuous coating layer can be formed on the surface of superhydrophobic carbon nanotubes and graphene oxide. Furthermore, superhydrophobic carbon nanotubes and graphene oxide have a good synergistic effect, which jointly improves the stability of the prepared carbon nanotube filler.
[0021] Secondly, this application provides a valve, which adopts the following technical solution: A valve comprising a valve body and a highly corrosion-resistant coating.
[0022] In summary, this application includes at least one of the following beneficial technical effects: Through the synergistic effect of tetrafluoroethylene film-forming substrate, nano-silica physical barrier, indole corrosion resistant agent and high temperature stabilizer, a multi-protection system with excellent physical barrier, active chemical corrosion inhibition and conductive reinforcement network is constructed, which significantly improves the coating's adhesion, density and comprehensive performance against pitting corrosion and stress corrosion cracking in harsh environments. Ammonium persulfate initiates the in-situ polymerization of indole on the Prussian blue surface, forming a stable chemically bonded composite structure between the two, which improves the problem of easy loss of organic corrosion inhibitors and enhances the long-term corrosion resistance of the coating. Carbon nanotubes were modified to be superhydrophobic and then pre-coated with graphene oxide in fluorocarbon resin and milled to obtain a composite filler with excellent dispersibility and strong interfacial bonding. It can construct a stable three-dimensional hydrophobic and reinforcing network in the coating, and simultaneously improve the coating's impermeability, mechanical strength and long-term stability. Detailed Implementation
[0023] The present application will be further described in detail below with reference to the embodiments: Raw material description: All raw materials in the examples are commercially available; among them, the high-temperature stabilizer is hindered phenol 1010. Example 1
[0024] Preparation of indole corrosion resistant agent: 5 mmol of potassium ferricyanide, 50 mL of 36% hydrochloric acid, 50 mL of deionized water, and 250 mL of N,N-dimethylformamide (CAS No.: 68-12-2) were mixed and magnetically stirred for 10 min to obtain a potassium ferricyanide solution. This solution was aged at 70°C for 48 h in a polytetrafluoroethylene-lined autoclave. The precipitate was then collected, washed alternately with deionized water and ethanol, dried in a vacuum oven at 80°C for 12 h, and ground. Prussian blue was then obtained. 5.63 g of indole (CAS No.: 120-72-9) and 4.79 g of Prussian blue were added to 200 g of deionized water, followed by 9.58 g of ammonium persulfate and 90 g of deionized water. The mixture was stirred at 5 °C for 6 h, and then centrifuged at 8000 rpm for 5 min. The precipitate was washed with deionized water and anhydrous ethanol until the supernatant was clear. Finally, it was vacuum dried in an oven at 60 °C for 24 h to obtain the indole corrosion resistant agent.
[0025] Preparation of superhydrophobic carbon nanotubes: 500g of deionized water was stirred, and then acetic acid was added to adjust the pH to 4. 8.18g of perfluorodecyltriethoxysilane (CAS No.: 101947-16-4) was mixed with 50g of anhydrous ethanol and added to the stirred solution. The mixture was stirred for 10 min to obtain a silanol solution. 6.82g of carbon nanotubes was mixed with 70g of anhydrous ethanol and sonicated for 10 min to obtain a carbon nanotube dispersion. The carbon nanotube dispersion was added to the silanol solution and stirred at 1000 rpm for 4 h at 70℃. After the reaction, the mixture was filtered and washed alternately with anhydrous ethanol and deionized water. Finally, it was dried in an oven at 80℃ for 6 h and ground to obtain superhydrophobic carbon nanotubes.
[0026] Preparation of carbon nanotube fillers: 23.08g of fluorocarbon resin, 20g of xylene (CAS No.: 1330-20-7) and 5g of butyl ester were mixed and stirred at 1000rpm for 20min to obtain a fluorocarbon resin dispersion system. 5.77g of superhydrophobic carbon nanotubes and 1.15g of graphene oxide were added to the fluorocarbon resin dispersion system and stirred at 1000rpm for 20min. Then the mixture was poured into a sand mill and milled at 2500rpm for 20min to obtain carbon nanotube filler.
[0027] Valve manufacturing: Mix 70g of tetrafluoroethylene and 6g of nano-silica, and stir at 1500rpm for 15min. Then add 2g of high-temperature stabilizer, 4g of indole corrosion resistant agent and 7g of carbon nanotube filler, and stir at 2000rpm for 20min to obtain a highly corrosion-resistant coating. Grind the surface of the valve body and degrease it at high temperature. Then fill the highly corrosion-resistant coating into the spray gun and electrostatically spray it onto the surface of the valve body. After high-temperature curing, a highly corrosion-resistant coating is formed. Example 2
[0028] Preparation of indole corrosion resistant agent: 5 mmol of potassium ferricyanide, 50 mL of 36% hydrochloric acid, 50 mL of deionized water, and 250 mL of N,N-dimethylformamide were mixed and magnetically stirred for 10 min to obtain a potassium ferricyanide solution. The potassium ferricyanide solution was aged in a polytetrafluoroethylene-lined autoclave at 70 °C for 48 h. The precipitate was then collected, washed alternately with deionized water and ethanol, and dried in a vacuum oven at 80 °C for 12 h. After grinding, Prussian blue was obtained. 5.48 g of indole and 5.21 g of Prussian blue were added to 200 g of deionized water, followed by 9.31 g of ammonium persulfate and 90 g of deionized water. The mixture was stirred at 5 °C for 6 h, and then centrifuged at 8000 rpm for 5 min. The precipitate was washed with deionized water and anhydrous ethanol until the supernatant was clear. Finally, it was vacuum dried in an oven at 60 °C for 24 h to obtain an indole corrosion resistant agent.
[0029] Preparation of superhydrophobic carbon nanotubes: 500g of deionized water was stirred, and then acetic acid was added to adjust the pH to 4. 8.48g of perfluorodecyltriethoxysilane was mixed with 50g of anhydrous ethanol and added to the stirred solution. The mixture was stirred for 10 min to obtain a silanol solution. 6.52g of carbon nanotubes was mixed with 70g of anhydrous ethanol and sonicated for 10 min to obtain a carbon nanotube dispersion. The carbon nanotube dispersion was added to the silanol solution and stirred at 1000 rpm for 4 h at 70°C. After the reaction, the mixture was filtered and washed alternately with anhydrous ethanol and deionized water. Finally, it was dried in an oven at 80°C for 6 h and ground to obtain superhydrophobic carbon nanotubes.
[0030] Preparation of carbon nanotube fillers: 21.43g of fluorocarbon resin, 20g of xylene, and 5g of butyl ester were mixed and stirred at 1000rpm for 20min to obtain a fluorocarbon resin dispersion system. 7.5g of superhydrophobic carbon nanotubes and 1.07g of graphene oxide were added to the fluorocarbon resin dispersion system, and the mixture was stirred and dispersed at 1000rpm for 20min. Then, the mixture was poured into a sand mill and milled at 2500rpm for 20min to obtain carbon nanotube filler.
[0031] Valve manufacturing: Mix 90g of tetrafluoroethylene and 12g of nano-silica, and stir at 1500rpm for 15min. Then add 4g of high-temperature stabilizer, 8g of indole corrosion resistant agent and 11g of carbon nanotube filler, and stir at 2000rpm for 20min to obtain a highly corrosion-resistant coating. Grind the surface of the valve body and degrease it at high temperature. Then fill the highly corrosion-resistant coating into the spray gun and electrostatically spray it onto the surface of the valve body. After high-temperature curing, a highly corrosion-resistant coating is formed. Example 3
[0032] Preparation of indole corrosion resistant agent: 5 mmol of potassium ferricyanide, 50 mL of 36% hydrochloric acid, 50 mL of deionized water, and 250 mL of N,N-dimethylformamide were mixed and magnetically stirred for 10 min to obtain a potassium ferricyanide solution. The potassium ferricyanide solution was aged in a polytetrafluoroethylene-lined autoclave at 70 °C for 48 h. The precipitate was then collected, washed alternately with deionized water and ethanol, and dried in a vacuum oven at 80 °C for 12 h. After grinding, Prussian blue was obtained. 5.56 g of indole and 5 g of Prussian blue were added to 200 g of deionized water, followed by 9.44 g of ammonium persulfate and 90 g of deionized water. The mixture was stirred at 5 °C for 6 h, and then centrifuged at 8000 rpm for 5 min. The precipitate was washed with deionized water and anhydrous ethanol until the supernatant was clear. Finally, it was vacuum dried in an oven at 60 °C for 24 h to obtain an indole corrosion inhibitor.
[0033] Preparation of superhydrophobic carbon nanotubes: 500g of deionized water was stirred, and then acetic acid was added to adjust the pH to 4. 8.33g of perfluorodecyltriethoxysilane was mixed with 50g of anhydrous ethanol and added to the stirred solution. The mixture was stirred for 10 min to obtain a silanol solution. 6.67g of carbon nanotubes was mixed with 70g of anhydrous ethanol and sonicated for 10 min to obtain a carbon nanotube dispersion. The carbon nanotube dispersion was added to the silanol solution and stirred at 1000 rpm for 4 h at 70°C. After the reaction, the mixture was filtered and washed alternately with anhydrous ethanol and deionized water. Finally, it was dried in an oven at 80°C for 6 h and ground to obtain superhydrophobic carbon nanotubes.
[0034] Preparation of carbon nanotube fillers: 22.22g of fluorocarbon resin, 20g of xylene, and 5g of butyl ester were mixed and stirred at 1000rpm for 20min to obtain a fluorocarbon resin dispersion system. 6.67g of superhydrophobic carbon nanotubes and 1.11g of graphene oxide were added to the fluorocarbon resin dispersion system and stirred at 1000rpm for 20min. The mixture was then poured into a sand mill and milled at 2500rpm for 20min to obtain carbon nanotube filler.
[0035] Valve manufacturing: Mix 80g of tetrafluoroethylene and 9g of nano-silica, and stir at 1500rpm for 15min. Then add 3g of high-temperature stabilizer, 6g of indole corrosion resistant agent and 9g of carbon nanotube filler, and stir at 2000rpm for 20min to obtain a highly corrosion-resistant coating. Grind the surface of the valve body and degrease it at high temperature. Then fill the highly corrosion-resistant coating into the spray gun and electrostatically spray it onto the surface of the valve body. After high-temperature curing, a highly corrosion-resistant coating is formed. Example 4
[0036] Example 4 is based on Example 3. In Example 4, when preparing the indole corrosion resistant agent, 5.88g of indole, 4.12g of Prussian blue, and 10g of ammonium persulfate were used. Example 5
[0037] Example 5 is based on Example 3. In Example 5, when preparing the indole corrosion resistant agent, 5.26g of indole, 5.79g of Prussian blue, and 8.95g of ammonium persulfate were used. Example 6
[0038] Example 6 is based on Example 3. In Example 6, when preparing superhydrophobic carbon nanotubes, 7.32 g of carbon nanotubes and 7.68 g of perfluorodecyltriethoxysilane were used. Example 7
[0039] Example 7 is based on Example 3. In Example 7, 6.12 g of carbon nanotubes and 8.88 g of perfluorodecyltriethoxysilane were used in the preparation of superhydrophobic carbon nanotubes. Example 8
[0040] Example 8 is based on Example 3. In Example 8, when preparing carbon nanotube fillers, 25g of fluorocarbon resin, 3.75g of superhydrophobic carbon nanotubes, and 1.25g of graphene oxide were used. Example 9
[0041] Example 9 is based on Example 3. In Example 9, when preparing carbon nanotube fillers, 20g of fluorocarbon resin, 9g of superhydrophobic carbon nanotubes, and 1g of graphene oxide were used. Example 10
[0042] Example 10 is based on Example 3. In Example 10, the superhydrophobic carbon nanotubes used in the preparation of carbon nanotube fillers were replaced with an equal amount of ordinary carbon nanotubes.
[0043] Example 11
[0044] Example 11 is based on Example 3, but no graphene oxide was added during the preparation of carbon nanotubes in Example 11. Example 12
[0045] Example 12 is based on Example 3. In Example 12, when preparing a highly corrosion-resistant coating, the carbon nanotube filler is replaced with an equal amount of superhydrophobic carbon nanotubes.
[0046] Comparative Example 1 Comparative Example 1 is based on Example 3, except that the indole corrosion resistant agent in Comparative Example 1 is replaced with an equal amount of indole.
[0047] Comparative Example 2 Comparative Example 2 is based on Example 3, but without the addition of indole corrosion resistant agent and with an equal amount of tetrafluoroethylene.
[0048] Comparative Example 3 Comparative Example 3 is based on Example 3, but without the addition of nano-silica.
[0049] Performance testing The following performance tests were performed on the samples of Examples 1-12 and Comparative Examples 1-3: (1) Corrosion resistance Using GB / T 10125-2021 as the testing reference, the corrosion resistance of the samples was tested. Each sample was tested 3 times, and the average value was taken. The test results were recorded in Table 1.
[0050] Using GB / T 1865-2009 as the test reference, the samples were continuously aged at 50℃ and 95% relative humidity, with 5% NaCl vapor introduced simultaneously. The time when corrosion and peeling occurred was recorded. Each sample was tested 3 times, and the average value was taken. The test results were recorded in Table 1.
[0051] (2) Impact resistance Using GB / T 1732-1993 as the testing reference, the impact strength of the samples was tested. Each sample was tested three times, and the test results were recorded in Table 1.
[0052] (3) Wear resistance Using GB / T 1768-2021 as the testing reference, the wear resistance of the samples was tested. Each sample was tested three times, and the test results were recorded in Table 1.
[0053] Table 1 Performance test results of Examples 1-12 and Comparative Examples 1-3
[0054] As shown in Table 1, the neutral salt spray corrosion time of Examples 1-3 is 1200h or more, the sodium chloride vapor aging time is 760h or more, the impact resistance is 6.8J or more, and the wear amount after 1000 cycles is less than 15mg. This indicates that the high corrosion resistance coating prepared in this application has good corrosion resistance, long-term corrosion resistance, impact strength and wear resistance.
[0055] In Examples 4 and 5, the mass ratio of indole, Prussian blue, and ammonium persulfate in the preparation of indole corrosion resistant agents was not within the range specified in this application. When Prussian blue was insufficient, its ion exchange and passivation capabilities were weakened. When Prussian blue was excessive, it would cover part of the active potential of indole. Both of these conditions would destroy the corrosion inhibition synergy between Prussian blue and indole, thereby affecting the stability of the coating.
[0056] In Examples 6 and 7, the mass ratio between carbon nanotubes and perfluorodecyltriethoxysilane during the preparation of superhydrophobic carbon nanotubes was not within the range specified in this application. When perfluorodecyltriethoxysilane was insufficient, the hydrophobicity of the carbon nanotubes was incomplete, and the coating had poor water penetration resistance. When too much perfluorodecyltriethoxysilane was added, an excessively thick insulating layer would form on the surface of the carbon layer, hindering the formation of the three-dimensional network and affecting the volatilization of the corrosion inhibitor. Therefore, the performance of Examples 6 and 7 both decreased.
[0057] In Examples 8 and 9, the mass ratio of fluorocarbon resin, superhydrophobic carbon nanotubes, and graphene oxide during the preparation of carbon nanotube fillers was not within the range specified in this application. When there was insufficient superhydrophobic carbon nanotubes, it was difficult to form a complete three-dimensional network with graphene oxide, resulting in a decrease in the improvement effect of corrosion medium penetration and insufficient fluorocarbon resin coating, leading to a decrease in the proportion of nano-reinforced phase. When there was an excess of superhydrophobic carbon nanotubes, it was difficult for the fluorocarbon resin to fully coat the nanomaterials, causing agglomeration, generating a large number of voids inside the coating, reducing corrosion resistance, and destroying the uniformity and stability of the coating.
[0058] In Example 10, superhydrophobic carbon nanotubes were replaced with an equal amount of ordinary carbon nanotubes. Ordinary carbon nanotubes do not have hydrophobic properties, making it difficult to further block the penetration of corrosive media and moisture. They also tend to agglomerate in the system, resulting in poor coating density. Furthermore, they have poor compatibility with fluorocarbon resins and tetrafluoroethylene materials, leading to decreased interfacial bonding and affecting the overall stability of the system.
[0059] In Example 11, no graphene oxide was added during the preparation of carbon nanotubes. As a result, the stability of the three-dimensional network constructed by the carbon nanotubes was difficult to improve further, the corrosive medium was easily penetrated, and the mechanical reinforcement effect of graphene oxide was missing, leading to a decrease in stability.
[0060] In Example 12, the carbon nanotube filler was replaced with an equal amount of superhydrophobic carbon nanotubes. Without the coating of fluorocarbon resin, the superhydrophobic carbon nanotubes agglomerated in the system, resulting in poor compatibility with the coating substrate, increased porosity inside the coating, reduced resistance to the penetration of corrosive media, and decreased system stability due to agglomeration.
[0061] In Comparative Example 1, replacing the indole corrosion inhibitor with an equal amount of indole resulted in the loss of the synergistic mechanism of inorganic-organic composite corrosion inhibition. Only a monomolecular film was formed to inhibit corrosion, and the film layer formed lacked long-term stability.
[0062] Comparative Example 2 did not add indole corrosion resistant agent, thus losing its active corrosion resistance. It only achieved corrosion resistance through nano-silica and carbon nanotube fillers. However, corrosive media could easily penetrate it, resulting in a decrease in corrosion resistance.
[0063] Comparative Example 3 did not contain nano-silica. This made it difficult to extend the medium penetration path, and the adhesion between the medium and the metal substrate was difficult to further improve, resulting in decreased mechanical properties and stability.
[0064] This specific embodiment is merely an explanation of this application and is not intended to limit it. Based on the above description, those skilled in the art can make various changes and modifications without departing from the technical concept of this application. The technical scope of this application is not limited to the contents of the specification but must be determined according to the scope of the claims.
Claims
1. A highly corrosion-resistant coating, characterized in that: The components include the following parts by mass: 70-90 parts of tetrafluoroethylene, 6-12 parts of nano-silica, 2-4 parts of high-temperature stabilizer, 4-8 parts of indole corrosion resistant agent, and 3-5 parts of carbon nanotube filler. The indole corrosion resistant agent includes Prussian blue and indole.
2. The highly corrosion-resistant coating according to claim 1, characterized in that: The indole corrosion resistant agent is prepared by the following method: Potassium ferricyanide, hydrochloric acid, and water were mixed and added to N,N-dimethylformamide. After stirring, a potassium ferricyanide solution was obtained. The potassium ferricyanide solution was heated and aged, and the precipitate was collected by centrifugation, washed, and dried to obtain Prussian blue. Indole and Prussian blue were added to deionized water, and then ammonium persulfate solution was added. The mixture was stirred and reacted, then centrifuged, washed, and dried to obtain an indole corrosion resistant agent.
3. The highly corrosion-resistant coating according to claim 2, characterized in that: The mass ratio of indole, Prussian blue and ammonium persulfate is 1:(0.85-0.95):1.
7.
4. The highly corrosion-resistant coating according to claim 1, characterized in that: The carbon nanotube filler materials include superhydrophobic carbon nanotubes, graphene oxide, and fluorocarbon resin.
5. The highly corrosion-resistant coating according to claim 4, characterized in that: The superhydrophobic carbon nanotubes were prepared using the following method: Water, acetic acid and anhydrous ethanol were mixed, and then perfluorodecyltriethoxysilane was added. After stirring, a silanol solution was obtained. Carbon nanotubes were mixed with ethanol, stirred and dispersed, and then added to the silanol solution. The mixture was heated and stirred to react. After the reaction, the mixture was filtered, washed and dried to obtain superhydrophobic carbon nanotubes.
6. The highly corrosion-resistant coating according to claim 5, characterized in that: The mass ratio of the carbon nanotubes to perfluorodecyltriethoxysilane is 1:(1.2-1.3).
7. The highly corrosion-resistant coating according to claim 4, characterized in that: The carbon nanotube filler was prepared by the following method: Fluorocarbon resin, xylene, and butyl ester were mixed to obtain a fluorocarbon resin dispersion system. Superhydrophobic carbon nanotubes and graphene oxide were added to the fluorocarbon resin dispersion system, dispersed, and then milled to obtain carbon nanotube fillers.
8. The highly corrosion-resistant coating according to claim 7, characterized in that: The mass ratio of the fluorocarbon resin, superhydrophobic carbon nanotubes and graphene oxide is 1:(0.25-0.35):0.
05.
9. A valve applied to the highly corrosion-resistant coating as described in claims 1-8, characterized in that: This includes the valve body and a highly corrosion-resistant coating.