Nanoceramic anticorrosive heat-dissipating coating

Abstract

The application discloses a kind of nano ceramic anticorrosive heat dissipation coating, belong to the field of coating technology. Including paint A component and curing agent B component, wherein paint A component includes the following weight parts of raw materials: 40-60 parts modified epoxy resin, 15-20 parts modified ceramic powder, 35-55 parts solvent, 0.6-1.2 parts dispersing agent, 0.3-0.6 parts defoaming agent, 0.2-0.4 parts leveling agent.The coating prepared by the application can significantly improve the heat dissipation and corrosion resistance of the coating by introducing four kinds of ceramic fillers; the dispersibility and interfacial adhesion of the filler in the resin matrix are improved by surface modification of the ceramic powder with silane coupling agent, and the overall performance is improved; the corrosion resistance and heat resistance of the coating are further improved by modifying the epoxy resin; in conclusion, the application successfully integrates the corrosion protection and heat dissipation functions, solving the problem of traditional coatings being difficult to balance corrosion protection and heat dissipation performance.

Description

Technical Field

[0001] This invention belongs to the field of coating technology, specifically relating to a nano-ceramic anti-corrosion and heat dissipation coating. Background Technology

[0002] In modern industry and technology, the durability and thermal management performance of materials are increasingly becoming key factors determining the reliability, efficiency, and service life of equipment. Particularly in industries such as aerospace, marine engineering, power electronics, chemical equipment, and high-end manufacturing, the surfaces of metal structural components have long faced a severe dual challenge: corrosion from environmental media and the accumulation of heat generated during operation. For example, radiators in power systems, towers and blades of offshore wind turbines, chips and casings in electronic devices, and chemical reaction vessels and pipelines are often simultaneously exposed to corrosive environments such as high temperature, high humidity, salt spray, and acidic or alkaline atmospheres, and are themselves important heat sources or require good heat dissipation to ensure operational efficiency.

[0003] Traditional strategies typically involve coating the metal substrate with an anti-corrosion coating to isolate it from corrosive media. Currently available anti-corrosion coatings primarily rely on the density of the film-forming material to block the penetration of corrosive agents such as water and oxygen, or provide cathodic protection by adding active rust-inhibiting pigments (such as zinc powder). However, these organic polymer film-forming materials, such as epoxy resins and acrylic resins, typically have extremely low intrinsic thermal conductivity, essentially making them poor conductors of heat and severely hindering lateral heat conduction and dissipation. When equipment is operating, heat is trapped within the metal substrate and coating, unable to be effectively dissipated, leading to a continuous rise in localized equipment temperature. High-temperature environments not only accelerate the aging, chalking, loss of gloss, and discoloration of organic coatings, reducing their protective lifespan, but also, in turn, exacerbate the electrochemical corrosion rate of the metal substrate, creating a vicious cycle of corrosion and overheating, posing a serious threat to the safe and stable operation of the equipment.

[0004] On the other hand, some materials focused on heat dissipation, such as pure ceramic coatings or thermally conductive coatings filled with conventional oxides (such as micron-sized alumina and zinc oxide), may possess relatively good thermal conductivity, but their inherent structure often fails to provide long-term effective barrier protection. Furthermore, they are prone to peeling under mechanical shock or thermal cycling, thus providing a channel for the intrusion of corrosive media and significantly reducing their anti-corrosion performance. Therefore, the industry urgently needs a coating that can organically integrate long-term anti-corrosion and efficient heat dissipation functions to meet the higher demands of the coating technology field. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a nano-ceramic anti-corrosion and heat dissipation coating.

[0006] The objective of this invention can be achieved through the following technical solutions: A nano-ceramic anti-corrosion and heat dissipation coating includes paint component A and curing agent component B.

[0007] Preferably, the mass ratio of paint component A to curing agent component B is 10:1-2.

[0008] Preferably, component B of the curing agent is a polyamide curing agent.

[0009] Preferably, the paint component A comprises the following raw materials in parts by weight: 40-60 parts modified epoxy resin, 15-20 parts modified ceramic powder, 35-55 parts solvent, 0.6-1.2 parts dispersant, 0.3-0.6 parts defoamer, and 0.2-0.4 parts leveling agent.

[0010] Preferably, the solvent is a mixture of propylene glycol methyl ether acetate and isopropanol in a weight ratio of 7:3.

[0011] Preferably, the modified epoxy resin is prepared by the following steps: Step 1: Dry the three-necked flask until it is free of moisture, assemble it with a reflux apparatus and thermometer, place it on a magnetic stirrer, add myristic acid, diethylenetriamine and anhydrous xylene to the flask, start stirring, and heat to 160-170℃. After refluxing for 3-4 hours, continue to heat to 200-210℃ and react for 2-3 hours. After the reaction is complete, perform post-processing to obtain the intermediate product. Step 2: Dry the three-necked flask until it is free of moisture, assemble the constant pressure dropping funnel and nitrogen gas delivery tube, place it on a magnetic stirrer, add terephthalic diisocyanate and anhydrous toluene to the flask, turn on the stirrer, purge the system with nitrogen three times to maintain nitrogen protection, dissolve the intermediate product in anhydrous toluene, then transfer it to the constant pressure dropping funnel and slowly add it dropwise to the flask over a period of 20-30 minutes. After the addition is complete, continue the reaction at room temperature for 2-3 hours. After the reaction is complete, perform post-processing to obtain the preservative. Step 3: Dry the three-necked flask until it is free of moisture, assemble the condenser and nitrogen gas delivery tube, place it on a magnetic stirrer, and add bisphenol A epoxy resin, preservative, 2-methylimidazole and ethylene glycol diglycidyl ether to the flask in sequence. Start stirring, purge with nitrogen for protection, heat to 120-130℃, and reflux at this temperature for 4-5 hours. After the reaction is complete, perform post-treatment to obtain the modified epoxy resin.

[0012] Preferably, the ratio of myristic acid, diethylenetriamine, and anhydrous xylene in step one is 22.8g:10.3g:100mL.

[0013] Preferably, in step two, the ratio of the amount of phenyl diisocyanate, intermediate product, and anhydrous toluene is 17.3-18.5g:29.5g:100mL.

[0014] Preferably, in step three, the ratio of bisphenol A epoxy resin, preservative, 2-methylimidazole, and ethylene glycol diglycidyl ether is 50g:3.5g:0.3g:100mL.

[0015] In the above process for preparing modified epoxy resin, the reaction formulas for steps one and two are as follows: In the preparation of modified epoxy resin, in step one, myristic acid first undergoes an amidation reaction with diethylenetriamine, followed by a cyclization reaction at elevated temperature to obtain an intermediate product containing an imidazoline structure. In step two, it is reacted with terephthalic diisocyanate, with the molar ratio controlled to be close to 1:1 and the latter slightly in excess, to obtain a preservative containing isocyanate groups. Finally, in step three, under the catalysis of 2-methylimidazole, the isocyanate groups in the preservative react with the epoxy groups in the epoxy resin to obtain the modified epoxy resin.

[0016] This invention introduces imidazoline and oxazolidinone structures into epoxy resin through a three-step reaction. The imidazoline, acting as a corrosion inhibitor, is physically and chemically adsorbed onto the metal surface. Due to its tridecyl structure at one end, it possesses strong hydrophobicity, thus forming a dense, monomolecular hydrophobic protective film on the metal surface, significantly improving the coating's anti-corrosion performance. The introduced oxazolidinone, with its rigid aromatic heterocyclic structure, enhances the coating's heat resistance. Finally, linking the corrosion inhibitor to the epoxy resin further improves the inhibitor's stability.

[0017] Preferably, the modified ceramic powder is prepared by the following steps: Flake-shaped nano-aluminum nitride, flake-shaped mica powder, nano-silica, and yttrium-stabilized zirconium oxide are premixed in a high-speed mixer for 5-10 minutes. Then, silane coupling agent KH-560 is mixed with an ethanol aqueous solution and slowly added to the mixed powder that is being stirred at a low speed. After the addition is complete, the temperature is raised to 80-90℃ and stirring is continued for 40-60 minutes. The mixture is then removed and vacuum dried to obtain modified ceramic powder.

[0018] Flaky nano-aluminum nitride has extremely high thermal conductivity, which can significantly improve the heat dissipation performance of coatings; flaky micron-sized mica powder, as an anti-corrosion filler, has a unique flaky structure that overlaps in parallel in the coating, forming a "maze effect," which can effectively extend the penetration path of corrosive media such as water, oxygen, and chloride ions, greatly improving the anti-corrosion performance of the coating; yttrium-stabilized zirconium oxide has excellent thermal stability and chemical inertness, which can improve the high-temperature resistance and corrosion resistance of the coating; finally, the above fillers are modified with silane coupling agents, which greatly improves the dispersibility and interfacial bonding of the fillers in the resin, avoids interfacial defects, and makes the fillers more effective in improving the performance of the coating.

[0019] Preferably, the mass ratio of the sheet-like nano-aluminum nitride, sheet-like mica powder, nano-silica, and yttrium-stabilized zirconium oxide is 8:12:5:5.

[0020] Preferably, the amount of the silane coupling agent KH-560 is 10-15% of the total mass of the ceramic powder.

[0021] Preferably, the premixing speed is 1000-1200 rpm.

[0022] Preferably, the low-speed stirring speed is 500-600 rpm.

[0023] Preferably, the vacuum drying temperature is 80-90℃ and the time is 2-3 hours.

[0024] The beneficial effects of this invention are: 1. The coating prepared by this invention, by introducing four kinds of ceramic fillers, can significantly improve the heat dissipation and corrosion resistance of the coating; 2. Surface modification of ceramic powder by silane coupling agent improves the dispersibility and interfacial bonding of fillers in resin matrix, reduces internal defects in coating, and enhances overall performance. 3. By modifying the epoxy resin, the anti-corrosion and heat resistance properties of the coating were further improved; In summary, this invention successfully integrates corrosion protection and heat dissipation functions, solving the problem that traditional coatings cannot simultaneously achieve both corrosion protection and heat dissipation performance. It is suitable for fields such as metal structural components that have high requirements for material corrosion protection and heat dissipation performance. Detailed Implementation

[0025] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and 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.

[0026] Example 1 Preparation of modified epoxy resin: Step 1: Dry the three-necked flask until it is free of moisture, assemble the reflux apparatus and thermometer, place it on a magnetic stirrer, add 22.8g myristic acid, 10.3g diethylenetriamine and 100mL anhydrous xylene to the flask, start stirring, and heat to 160℃. After refluxing for 3 hours, continue heating to 200℃ and react for 2 hours. After the reaction is complete, cool the reaction solution to room temperature under vacuum and then perform vacuum distillation to obtain the intermediate product. Step 2: Dry the three-necked flask until it is free of moisture. Assemble a constant-pressure dropping funnel and a nitrogen gas delivery tube. Place the flask on a magnetic stirrer. Add 17.3 g of terephthalic diisocyanate and 50 mL of anhydrous toluene to the flask. Start stirring and purge the system with nitrogen three times to maintain nitrogen protection. Dissolve 29.5 g of the intermediate product in 50 mL of anhydrous toluene and transfer it to the constant-pressure dropping funnel. Slowly add the solution dropwise to the flask over 20 min. After the addition is complete, continue the reaction at room temperature for 2 h while maintaining nitrogen protection. Connect the system to a vacuum distillation apparatus to remove the toluene solvent by distillation. Purify by column chromatography (using petroleum ether and ethyl acetate as eluents in a volume ratio of 5:1) to obtain the preservative. Step 3: Dry the three-necked flask until it is free of moisture, assemble the condenser and nitrogen gas delivery tube, place it on a magnetic stirrer, and add 50g of bisphenol A epoxy resin, 3.5g of preservative, 0.3g of 2-methylimidazole and 100mL of ethylene glycol diglycidyl ether to the flask in sequence. Start stirring, purge with nitrogen for protection, heat to 120℃, and reflux at this temperature for 4 hours. After the reaction is complete, cool the reaction system, connect it to a rotary evaporator, and rotary evaporate under vacuum to obtain the modified epoxy resin. Preparation of modified ceramic powder: Eight parts of flake-shaped nano-aluminum nitride, 12 parts of flake-shaped mica powder, 5 parts of nano-silica and 5 parts of yttrium-stabilized zirconium oxide were premixed in a high-speed mixer at 1000 rpm for 5 min. Then, 3 g of silane coupling agent KH-560 was mixed with an ethanol aqueous solution and slowly added to the mixed powder being stirred at a low speed of 500 rpm. After the addition was complete, the temperature was raised to 80℃ and stirred for another 40 min. The mixture was then removed and vacuum dried at 80℃ for 2 h to obtain modified ceramic powder. A nano-ceramic anti-corrosion and heat dissipation coating is prepared through the following steps: A1. In a dispersion vessel, add 40 parts of modified epoxy resin, 35 parts of solvent (propylene glycol methyl ether acetate and isopropanol mixed in a weight ratio of 7:3), 0.6 parts of dispersant (BYK-2150), 0.3 parts of defoamer (BYK-066N), and 0.2 parts of leveling agent (BYK-331) in sequence. Stir at 300 rpm for 15 minutes to ensure that the raw material components are mixed evenly. A2. Under continuous stirring (300 rpm), add 15 parts of modified ceramic powder to the dispersion vessel. After the feeding is completed, increase the stirring speed to 1300 rpm and disperse at high speed for 30 minutes to obtain a mixed slurry. A3. Transfer the mixed slurry to a basket mill and use zirconia beads (0.6-0.8mm in diameter) as the grinding medium for cyclic grinding for 3 hours until the fineness of the slurry reaches ≤25μm. Filter with a 200-mesh filter to obtain paint component A. A4. Before use, mix 50 parts of paint component A with 5 parts of curing agent component B (polyamide 650), let stand for 15 minutes to remove air bubbles introduced by stirring, and obtain nano-ceramic anti-corrosion and heat dissipation coating.

[0027] Example 2 Preparation of modified epoxy resin: Step 1: Dry the three-necked flask until it is free of moisture, assemble the reflux apparatus and thermometer, place it on a magnetic stirrer, add 22.8g myristic acid, 10.3g diethylenetriamine and 100mL anhydrous xylene to the flask, start stirring, and heat to 170℃. After refluxing for 4 hours, continue heating to 210℃ and react for 3 hours. After the reaction is complete, cool the reaction solution to room temperature under vacuum and then perform vacuum distillation to obtain the intermediate product. Step 2: Dry the three-necked flask until it is free of moisture. Assemble a constant-pressure dropping funnel and a nitrogen gas delivery tube. Place the flask on a magnetic stirrer. Add 18.5g of terephthalic diisocyanate and 50mL of anhydrous toluene to the flask. Start stirring and purge the system with nitrogen three times to maintain nitrogen protection. Dissolve 29.5g of the intermediate product in 50mL of anhydrous toluene and transfer it to the constant-pressure dropping funnel. Slowly add the solution dropwise to the flask over 30 minutes. After the addition is complete, continue the reaction at room temperature for 3 hours while maintaining nitrogen protection. Connect the system to a vacuum distillation apparatus to remove the toluene solvent by distillation. Purify the solution by column chromatography (using petroleum ether and ethyl acetate as eluents in a volume ratio of 5:1) to obtain the preservative. Step 3: Dry the three-necked flask until it is free of moisture, assemble the condenser and nitrogen gas delivery tube, place it on a magnetic stirrer, and add 50g of bisphenol A epoxy resin, 3.5g of preservative, 0.3g of 2-methylimidazole and 100mL of ethylene glycol diglycidyl ether to the flask in sequence. Start stirring, purge with nitrogen, heat to 130℃, and reflux at this temperature for 5 hours. After the reaction is complete, cool the reaction system, connect it to a rotary evaporator, and rotary evaporate under vacuum to obtain the modified epoxy resin. Preparation of modified ceramic powder: Eight parts of flake-shaped nano-aluminum nitride, 12 parts of flake-shaped mica powder, 5 parts of nano-silica and 5 parts of yttrium-stabilized zirconium oxide were premixed in a high-speed mixer at 1200 rpm for 10 min. Then, 4.5 g of silane coupling agent KH-560 was mixed with an ethanol aqueous solution and slowly added to the mixed powder being stirred at a low speed of 600 rpm. After the addition was complete, the temperature was raised to 90 °C and stirred for another 60 min. The mixture was then removed and vacuum dried at 90 °C for 3 h to obtain modified ceramic powder. A nano-ceramic anti-corrosion and heat dissipation coating is prepared through the following steps: A1. In a dispersion vessel, add 50 parts of modified epoxy resin, 45 parts of solvent (propylene glycol methyl ether acetate and isopropanol mixed in a weight ratio of 7:3), 0.9 parts of dispersant (BYK-2150), 0.45 parts of defoamer (BYK-066N), and 0.3 parts of leveling agent (BYK-331) in sequence. Stir at 400 rpm for 20 minutes to ensure that the raw material components are mixed evenly. A2. Under continuous stirring (400 rpm), add 17.5 parts of modified ceramic powder to the dispersion vessel. After the feeding is completed, increase the stirring speed to 1400 rpm and disperse at high speed for 30 minutes to obtain a mixed slurry. A3. Transfer the mixed slurry to a basket mill and use zirconia beads (0.6-0.8mm in diameter) as the grinding medium for cyclic grinding for 4 hours until the fineness of the slurry reaches ≤25μm. Filter with a 200-mesh filter to obtain paint component A. A4. Before use, mix 50 parts of paint component A with 7.5 parts of curing agent component B (polyamide 650), let stand for 20 minutes to remove air bubbles introduced by stirring, and obtain nano-ceramic anti-corrosion and heat dissipation coating.

[0028] Example 3 The only difference between this embodiment and Embodiment 2 is that, in this embodiment, a nano-ceramic anti-corrosion and heat dissipation coating is prepared through the following steps: A1. In a dispersion vessel, add 60 parts of modified epoxy resin, 55 parts of solvent (a mixture of propylene glycol methyl ether acetate and isopropanol in a weight ratio of 7:3), 1.2 parts of dispersant (BYK-2150), 0.6 parts of defoamer (BYK-066N), and 0.4 parts of leveling agent (BYK-331) in sequence. Stir at 400 rpm for 15-20 minutes to ensure that the raw material components are mixed evenly. A2. Under continuous stirring (400 rpm), add 20 parts of modified ceramic powder to the dispersion vessel. After the feeding is completed, increase the stirring speed to 1500 rpm and disperse at high speed for 30 minutes to obtain a mixed slurry. A3. Transfer the mixed slurry to a basket mill and use zirconia beads (0.6-0.8mm in diameter) as the grinding medium for cyclic grinding for 4 hours until the fineness of the slurry reaches ≤25μm. Filter with a 200-mesh filter to obtain paint component A. A4. Before use, mix 50 parts of paint component A with 10 parts of curing agent component B (polyamide 650), let stand for 20 minutes to remove air bubbles introduced by stirring, and obtain nano-ceramic anti-corrosion and heat dissipation coating.

[0029] Comparative Example 1 The only difference between this comparative example and Example 3 is that in this comparative example, an equal amount of bisphenol A epoxy resin was used to replace the modified epoxy resin to prepare the coating.

[0030] Comparative Example 2 Use commercially available epoxy resin anti-corrosion coating, model Hempadur15570.

[0031] The following performance tests were conducted on Examples 1, 2, and 3, and Comparative Examples 1 and 2: The national standard GB / T 9274 "Determination of resistance to liquid media for paints and varnishes" was adopted. The test samples were immersed in 5% H2SO4 solution and 10% NaOH solution for 100 h respectively, and then removed and the surface condition of the samples was observed. The sample was immersed in water for 100 hours according to the national standard GB / T 1733 "Determination of Water Resistance of Paint Film", and then the sample surface was observed. The samples were placed in an oven at 200℃ and aged for 100 hours according to the national standard GB / T 1735 "Determination of heat resistance of paints and varnishes". The samples were then removed and the surface condition of the samples was observed. The thermal conductivity was determined using the national standard GB / T 10297 "Determination of Thermal Conductivity of Non-metallic Solid Materials - Hot Wire Method". The performance test results are shown in Table 1: Table 1 Acid resistance No change No change No change Slight bubbling No change Alkali resistance No change No change No change Slight bubbling No change Water resistance No change No change No change Slight bubbling No change Heat resistance No change No change No change Slight bubbling Bubbling and peeling Thermal conductivity (W / m·K) 1.2 1.2 1.2 1.2 0.4 As can be seen from the performance test results in Table 1, the coating prepared by the embodiments of the present invention has excellent anti-corrosion, heat dissipation and heat resistance properties, and is suitable for fields such as metal structural parts that have high requirements for material anti-corrosion and heat dissipation performance.

[0032] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. A nano-ceramic anti-corrosion and heat dissipation coating, comprising paint component A and curing agent component B, characterized in that, The paint component A comprises the following raw materials in parts by weight: 40-60 parts modified epoxy resin, 15-20 parts modified ceramic powder, 35-55 parts solvent, 0.6-1.2 parts dispersant, 0.3-0.6 parts defoamer, and 0.2-0.4 parts leveling agent; The modified epoxy resin is prepared through the following steps: Step 1: Add myristic acid, diethylenetriamine and anhydrous xylene to the flask, start stirring and heat to 160-170℃, reflux for 3-4 hours, then continue heating to 200-210℃ and react for 2-3 hours. The reaction is then complete, and the intermediate product is obtained. Step 2: Add terephthalic diisocyanate and anhydrous toluene to the flask, start stirring, and under nitrogen protection, dissolve the intermediate product in anhydrous toluene and add it dropwise to the flask over 20-30 minutes. After the addition is complete, react at room temperature for 2-3 hours. Once the reaction is complete, the preservative is obtained. Step 3: Add bisphenol A epoxy resin, preservative, 2-methylimidazole and ethylene glycol diglycidyl ether to the flask in sequence, start stirring, purge with nitrogen, heat to 120-130℃, reflux for 4-5 hours, and the reaction is complete to obtain modified epoxy resin. In step one, the ratio of myristic acid, diethylenetriamine, and anhydrous xylene is 22.8g:10.3g:100mL; in step two, the ratio of terephthalic diisocyanate, intermediate product, and anhydrous toluene is 17.3-18.5g:29.5g:100mL; and in step three, the ratio of bisphenol A epoxy resin, preservative, 2-methylimidazole, and ethylene glycol diglycidyl ether is 50g:3.5g:0.3g:100mL.

2. The nano-ceramic anti-corrosion and heat dissipation coating according to claim 1, characterized in that, The solvent is a mixture of propylene glycol methyl ether acetate and isopropanol in a weight ratio of 7:

3.

3. The nano-ceramic anti-corrosion and heat-dissipation coating according to claim 1, characterized in that, The mass ratio of paint component A to curing agent component B is 10:1-2.

4. The nano-ceramic anti-corrosion and heat dissipating coating according to claim 1, characterized in that, The modified ceramic powder is prepared through the following steps: Flake-shaped nano-aluminum nitride, flake-shaped mica powder, nano-silica, and yttrium-stabilized zirconium oxide were premixed to obtain a mixed powder. Then, silane coupling agent KH-560 was mixed with an ethanol aqueous solution and added to the mixed powder. The mixture was heated to 80-90℃ and stirred for 40-60 minutes. After stirring, the mixture was removed and vacuum dried to obtain modified ceramic powder.

5. The nano-ceramic anti-corrosion and heat-dissipation coating according to claim 4, characterized in that, The mass ratio of the sheet-like nano-aluminum nitride, sheet-like mica powder, nano-silica, and yttrium-stabilized zirconium oxide is 8:12:5:

5.

6. The nano-ceramic anti-corrosive and heat dissipating coating according to claim 4, characterized in that, The amount of the silane coupling agent KH-560 is 10-15% of the total mass of the ceramic powder.

Images