An industrial anti-corrosion coating and its preparation method

Abstract

This invention relates to the field of coatings, specifically to an industrial anti-corrosion coating and its preparation method. The coating comprises a film-forming resin, a curing agent, a solvent, and an anti-corrosion composite nanofiller. The anti-corrosion composite nanofiller has a three-layer structure: a core layer of mesoporous silica loaded with an organic corrosion inhibitor; a middle shell layer of in-situ grown amino-functionalized metal-organic framework material; and an outer layer of low surface energy formed by modification with a hydrophobic modifier.

Description

Technical Field

[0001] This invention relates to the field of coatings, and more specifically to an industrial anti-corrosion coating and its preparation method. Background Technology

[0002] Industrial facilities, marine engineering projects, and transportation vehicles are exposed to harsh environments such as humidity and high salt spray for extended periods. Corrosion of the metal substrates seriously threatens structural safety and causes significant economic losses. Organic coating protection is currently one of the most effective and economical anti-corrosion methods. Among them, epoxy resin (EP) is widely used in heavy-duty industrial anti-corrosion applications due to its excellent adhesion, chemical resistance, and electrical insulation. However, traditional epoxy resin coatings inevitably develop micropores during the curing process due to solvent evaporation and cross-linking shrinkage; furthermore, the high cross-linking density of the cured resin results in high brittleness, making it prone to microcracks under alternating hot and cold temperatures or external impacts. Water molecules, oxygen, and chloride ions... Corrosive media can easily penetrate to the metal / coating interface through the diffusion channels formed by these pores and cracks, leading to coating blistering, peeling, and ultimately, underfilm corrosion. To overcome these defects, existing technologies often employ the addition of inorganic nanofillers (such as nano-silica, graphene oxide, etc.) to enhance the coating's impermeability. For example, a modified silica-coated graphene oxide (SiO2@GO) nanohybrid is disclosed in the prior art. Nano-SiO2 is loaded onto the graphene oxide surface using a silane coupling agent (such as APTES). This utilizes SiO2 particles to inhibit the stacking and agglomeration of GO sheets, and also utilizes the two-dimensional sheet structure of GO to form a "maze effect" in the coating, extending the diffusion path of corrosive media. Although this modified filler improves the hydrophobicity and physical barrier ability of the coating to some extent, it still has the following significant technical bottlenecks: lack of "active" repair function: existing composite fillers such as SiO2@GO mainly rely on physical shielding, which is a "passive defense". Once the coating surface is scratched due to mechanical friction or impact, or the physical barrier is penetrated due to prolonged immersion, corrosive media will quickly contact the metal substrate, triggering accelerated corrosion. Existing solid nanoparticles cannot load and release corrosion inhibitors and lack the ability to automatically repair the passivation film when the coating is damaged. They also cannot effectively remove penetrating chloride ions: Chloride ions in marine atmospheres or industrial environments have extremely strong penetrating power and are a core cause of pitting corrosion in metals. Existing physical barrier fillers can only delay corrosion. The arrival time is such that it cannot be chemically adsorbed or solidified. As service life extends, Accumulation under the coating leads to increased osmotic pressure, accelerating coating failure. Insufficient interfacial bonding and longevity: the interfacial compatibility between some inorganic nanofillers and the organic resin matrix still needs improvement, easily forming new defects at the interface. Furthermore, conventional hydrophobic modification is mostly physical adsorption or simple surface grafting; under long-term scouring and immersion environments, hydrophobic groups are prone to detachment or failure, making it difficult to maintain long-term superhydrophobic protective effects. Therefore, developing a novel industrial anti-corrosion coating with good interfacial bonding to the epoxy resin matrix and its preparation method is a key technical problem urgently needing to be solved in this field. Summary of the Invention

[0003] To address the problems existing in the prior art, this invention provides an industrial anti-corrosion coating and its preparation method.

[0004] This invention is achieved through the following technical solution:

[0005] An industrial anti-corrosion coating, the coating comprising a film-forming resin, a curing agent, a solvent, and a modified core-shell structured nanofiller with self-healing and ion-trapping functions; the modified core-shell structured nanofiller has a three-layer structure: the core is mesoporous silica loaded with an organic corrosion inhibitor; the middle shell is an in-situ grown amino-functionalized metal-organic framework material; and the outer layer is a low surface energy layer formed by modification with a hydrophobic modifier.

[0006] Furthermore, the amino-functionalized metal-organic framework material is an amino-zirconium-based metal-organic framework material UiO-66-NH2; the UiO-66-NH2 is formed by the coordination self-assembly of zirconium salt and 2-aminoterephthalic acid onto the surface of the core.

[0007] Furthermore, the mesoporous silica has an average particle size of 80-200 nm and a pore size of 2-10 nm; the organic corrosion inhibitor is selected from at least one of benzotriazole, 8-hydroxyquinoline, 2-mercaptobenzothiazole or imidazoline derivatives.

[0008] Furthermore, the hydrophobic modifier is a fluorinated silane or a long-chain alkyl silane; the fluorinated silane is selected from at least one of perfluorooctyltriethoxysilane, heptadecafluorodecyltrimethoxysilane, or perfluorododecyltriethoxysilane; the long-chain alkyl silane is selected from at least one of dodecyltrimethoxysilane or hexadecyltrimethoxysilane.

[0009] Furthermore, the amount of the modified core-shell structured nanofiller added to the coating is 0.5% to 3.0% of the mass of the film-forming resin.

[0010] Furthermore, the film-forming resin is a bisphenol A type epoxy resin; the curing agent is an amine curing agent.

[0011] Furthermore, the modified core-shell structured nanofiller undergoes a chemical cross-linking reaction with the film-forming resin through the amino groups on the surface of the intermediate shell layer.

[0012] The present invention also provides a method for preparing an industrial anti-corrosion coating, comprising the following steps: (1) dispersing mesoporous silica in an organic corrosion inhibitor solution, stirring under vacuum conditions, loading the organic corrosion inhibitor into the mesoporous channels using negative pressure, separating and drying to obtain mesoporous silica loaded with corrosion inhibitor; (2) dispersing the product obtained in step (1) in a precursor solution containing metal salt and organic ligand, performing an in-situ growth reaction under solvothermal conditions, and coating the surface with an amino-functionalized metal-organic framework material shell; (3) dispersing the product obtained in step (2) in a solvent, adding a hydrophobic modifier to perform a grafting reaction, and drying to obtain a modified core-shell structured nanofiller; (4) dispersing the modified core-shell structured nanofiller in a solvent, mixing it with a film-forming resin, adding a curing agent, and stirring evenly to obtain the industrial anti-corrosion coating.

[0013] Further, the metal salt in step (2) is zirconium tetrachloride, and the organic ligand is 2-aminoterephthalic acid; the reaction temperature under the solvothermal conditions is 100~140℃, and the reaction time is 12~36 hours. The mass ratio of the hydrophobic modifier in step (3) to the product obtained in step (2) is (0.5~1.5):1; the grafting reaction is carried out under the condition of pH 4~5, and the reaction temperature is 50~80℃.

[0014] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0015] This invention significantly improves the overall mechanical properties of the coating, solving the problems of brittleness and poor adhesion in traditional anti-corrosion coatings. The modified core-shell structured nanofiller (F-UiO-66-NH2@MSN-BTA) prepared in this invention is introduced into the epoxy resin matrix as a reinforcing phase, producing a significant strengthening and toughening effect. Test results show that, compared with the pure epoxy resin coating (Comparative Example 1), the coating with the filler of this invention (Example 1) exhibits an increased pencil hardness from 2H to 5H, increased adhesion from 2.54 MPa to 6.45 MPa, increased impact strength from 11.2 KJ / m² to 26.8 KJ / m², increased tensile strength from 56.2 MPa to 92.4 MPa, and significantly enhanced wear resistance (wear mass loss reduced by approximately 56%). This is attributed to the filler acting as a "physical pinning" and "crack deflector" in the resin matrix, effectively absorbing external impact energy and hindering the propagation of microcracks. The interfacial bonding strength is significantly improved, and the mechanical strengthening effect is superior to existing modified filler technologies. The UiO-66-NH2 shell selected in this invention is rich in active amino groups, which can directly participate in the ring-opening curing reaction of epoxy resin, forming a strong "molecular-level" covalent chemical bond between the inorganic filler and the organic matrix. This overcomes the shortcomings of conventional MOF materials in terms of interfacial compatibility. Compared with conventional zinc-based MOFs, the aminated zirconium-based MOF (UiO-66-NH2) used in this invention shows significant advantages in improving the mechanical properties of the coating. This invention encapsulates the corrosion inhibitor in a mesoporous silica core and then seals it with the MOF shell. This strategy not only achieves long-term storage and controlled release of the corrosion inhibitor but also avoids the plasticizing effect or mechanical property degradation that may be caused by directly adding small-molecule corrosion inhibitors to the resin. This ensures that the coating possesses excellent structural strength while maintaining self-healing capabilities. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the embodiments. The illustrative embodiments and descriptions of this invention are only for explaining this invention and are not intended to limit this invention.

[0017] In this invention, E51 epoxy resin (industrial grade, epoxy value 0.48~0.54); T31 curing agent (industrial grade, amine value 480~520); mesoporous silica nanospheres (MSN, average particle size 100nm, pore size 2.5nm); zirconium tetrachloride (ZrCl4), 2-aminoterephthalic acid (H2BDC-NH2), zinc nitrate hexahydrate Zn(NO3)2·6H2O, 2-methylimidazolium (2-MeIM); benzotriazole (BTA), 8-hydroxyquinoline (8-HQ); 1H,1H,2H,2H-perfluorooctyltriethoxysilane (PFDTES), dodecyltrimethoxysilane (DTMS); solvents and auxiliary reagents: N,N-dimethylformamide (DMF), anhydrous ethanol, methanol, glacial acetic acid, etc., are all of analytical grade.

[0018] Example 1

[0019] A method for preparing an industrial anti-corrosion coating is as follows: Weigh 0.1g of anti-corrosion composite nanofiller and add it to 10g of xylene / n-butanol (volume ratio 7:3) mixed solvent, and ultrasonically disperse for 30min. Add the dispersion to 10g of E51 epoxy resin, and shear and stir at 1500r / min for 20min. Then add 2.5g of T31 curing agent, stir at low speed until uniform, and degas under vacuum.

[0020] The preparation method of the corrosion-resistant composite nanofiller is as follows:

[0021] Step S1: Core Loading (MSN-BTA): Weigh 1.0 g of mesoporous silica (MSN) and disperse it in 40 mL of benzotriazole (BTA) ethanol solution with a concentration of 50 mg / mL. Place the mixture in a vacuum reactor and degas it ultrasonically for 30 min under a vacuum of -0.09 MPa, followed by magnetic stirring under vacuum for 12 h. Centrifuge the mixture, quickly wash the surface of the precipitate once with 5 mL of anhydrous ethanol (to remove physically adsorbed BTA), and dry it under vacuum at 45 °C for 12 h to obtain MSN-BTA.

[0022] Step S2: Intermediate Shell Growth (UiO-66-NH2@MSN-BTA): 233 mg ZrCl4 and 181 mg H2BDC-NH2 were dissolved in 30 mL DMF, and 2 mL glacial acetic acid was added as a regulator. The mixture was ultrasonically dissolved to obtain a precursor solution. 0.5 g MSN-BTA was added to this solution and ultrasonically dispersed for 30 min. The mixture was transferred to a polytetrafluoroethylene-lined hydrothermal reactor and reacted at 120 °C for 24 h. After the reaction, the product was centrifuged, washed three times each with DMF and methanol, and activated under vacuum at 80 °C for 12 h to obtain the core-shell structured UiO-66-NH2@MSN-BTA.

[0023] Step S3: Superhydrophobic modification of the outer layer (F-UiO-66-NH2@MSN-BTA): Disperse 0.5g of the above core-shell powder in 50mL of anhydrous ethanol, add 0.6g of PFDTES dropwise, add 2mL of water, and adjust the pH to 4.5 with acetic acid to promote hydrolysis. Recirculate and stir the mixture in a 60℃ water bath for 6h. After the reaction is complete, centrifuge, wash twice with ethanol, dry at 60℃, and grind to obtain the final composite filler.

[0024] Example 2

[0025] The difference between this embodiment and Embodiment 1 is that the content of the anti-corrosion composite nanofiller is reduced.

[0026] A method for preparing an industrial anti-corrosion coating is as follows: Weigh 0.05g of anti-corrosion composite nanofiller and add it to 10g of xylene / n-butanol (volume ratio 7:3) mixed solvent, and ultrasonically disperse for 30min. Add the dispersion to 10g of E51 epoxy resin, and shear and stir at 1500r / min for 20min. Then add 2.5g of T31 curing agent, stir at low speed until uniform, and degas under vacuum.

[0027] The preparation method of the corrosion-resistant composite nanofiller is as follows:

[0028] Step S1: Core Loading (MSN-BTA): Weigh 1.0 g of mesoporous silica (MSN) and disperse it in 40 mL of benzotriazole (BTA) ethanol solution with a concentration of 50 mg / mL. Place the mixture in a vacuum reactor and degas it ultrasonically for 30 min under a vacuum of -0.09 MPa, followed by magnetic stirring under vacuum for 12 h. Centrifuge the mixture, quickly wash the surface of the precipitate once with 5 mL of anhydrous ethanol (to remove physically adsorbed BTA), and dry it under vacuum at 45 °C for 12 h to obtain MSN-BTA.

[0029] Step S2: Intermediate Shell Growth (UiO-66-NH2@MSN-BTA): 233 mg ZrCl4 and 181 mg H2BDC-NH2 were dissolved in 30 mL DMF, and 2 mL glacial acetic acid was added as a regulator. The mixture was ultrasonically dissolved to obtain a precursor solution. 0.5 g MSN-BTA was added to this solution and ultrasonically dispersed for 30 min. The mixture was transferred to a polytetrafluoroethylene-lined hydrothermal reactor and reacted at 120 °C for 24 h. After the reaction, the product was centrifuged, washed three times each with DMF and methanol, and activated under vacuum at 80 °C for 12 h to obtain the core-shell structured UiO-66-NH2@MSN-BTA.

[0030] Step S3: Superhydrophobic modification of the outer layer (F-UiO-66-NH2@MSN-BTA): Disperse 0.5g of the above core-shell powder in 50mL of anhydrous ethanol, add 0.6g of PFDTES dropwise, add 2mL of water, and adjust the pH to 4.5 with acetic acid to promote hydrolysis. Recirculate and stir the mixture in a 60℃ water bath for 6h. After the reaction is complete, centrifuge, wash twice with ethanol, dry at 60℃, and grind to obtain the final composite filler.

[0031] Example 3

[0032] The difference between this embodiment and Embodiment 1 is that the content of anti-corrosion composite nanofiller is increased.

[0033] A method for preparing an industrial anti-corrosion coating is as follows: Weigh 0.3g of anti-corrosion composite nanofiller and add it to 10g of xylene / n-butanol (volume ratio 7:3) mixed solvent, and ultrasonically disperse for 30min. Add the dispersion to 10g of E51 epoxy resin, and shear and stir at 1500r / min for 20min. Then add 2.5g of T31 curing agent, stir at low speed until uniform, and degas under vacuum.

[0034] The preparation method of the corrosion-resistant composite nanofiller is as follows:

[0035] Step S1: Core Loading (MSN-BTA): Weigh 1.0 g of mesoporous silica (MSN) and disperse it in 40 mL of benzotriazole (BTA) ethanol solution with a concentration of 50 mg / mL. Place the mixture in a vacuum reactor and degas it ultrasonically for 30 min under a vacuum of -0.09 MPa, followed by magnetic stirring under vacuum for 12 h. Centrifuge the mixture, quickly wash the surface of the precipitate once with 5 mL of anhydrous ethanol (to remove physically adsorbed BTA), and dry it under vacuum at 45 °C for 12 h to obtain MSN-BTA.

[0036] Step S2: Intermediate Shell Growth (UiO-66-NH2@MSN-BTA): 233 mg ZrCl4 and 181 mg H2BDC-NH2 were dissolved in 30 mL DMF, and 2 mL glacial acetic acid was added as a regulator. The mixture was ultrasonically dissolved to obtain a precursor solution. 0.5 g MSN-BTA was added to this solution and ultrasonically dispersed for 30 min. The mixture was transferred to a polytetrafluoroethylene-lined hydrothermal reactor and reacted at 120 °C for 24 h. After the reaction, the product was centrifuged, washed three times each with DMF and methanol, and activated under vacuum at 80 °C for 12 h to obtain the core-shell structured UiO-66-NH2@MSN-BTA.

[0037] Step S3: Superhydrophobic modification of the outer layer (F-UiO-66-NH2@MSN-BTA): Disperse 0.5g of the above core-shell powder in 50mL of anhydrous ethanol, add 0.6g of PFDTES dropwise, add 2mL of water, and adjust the pH to 4.5 with acetic acid to promote hydrolysis. Recirculate and stir the mixture in a 60℃ water bath for 6h. After the reaction is complete, centrifuge, wash twice with ethanol, dry at 60℃, and grind to obtain the final composite filler.

[0038] Example 4

[0039] The difference between this embodiment and Embodiment 1 is that the type of organic corrosion inhibitor is different.

[0040] A method for preparing an industrial anti-corrosion coating is as follows: Weigh 0.1g of anti-corrosion composite nanofiller and add it to 10g of xylene / n-butanol (volume ratio 7:3) mixed solvent, and ultrasonically disperse for 30min. Add the dispersion to 10g of E51 epoxy resin, and shear and stir at 1500r / min for 20min. Then add 2.5g of T31 curing agent, stir at low speed until uniform, and degas under vacuum.

[0041] The preparation method of the corrosion-resistant composite nanofiller is as follows:

[0042] Step S1: Core Loading (MSN-BTA): Weigh 1.0 g of mesoporous silica (MSN) and disperse it in 40 mL of 50 mg / mL 8-hydroxyquinoline ethanol solution. Place the mixture in a vacuum reactor and degas it ultrasonically at -0.09 MPa for 30 min, followed by magnetic stirring under vacuum for 12 h. Centrifuge the mixture, quickly wash the surface of the precipitate once with 5 mL of anhydrous ethanol (to remove physically adsorbed BTA), and dry it under vacuum at 45 °C for 12 h to obtain MSN-BTA.

[0043] Step S2: Intermediate Shell Growth (UiO-66-NH2@MSN-BTA): 233 mg ZrCl4 and 181 mg H2BDC-NH2 were dissolved in 30 mL DMF, and 2 mL glacial acetic acid was added as a regulator. The mixture was ultrasonically dissolved to obtain a precursor solution. 0.5 g MSN-BTA was added to this solution and ultrasonically dispersed for 30 min. The mixture was transferred to a polytetrafluoroethylene-lined hydrothermal reactor and reacted at 120 °C for 24 h. After the reaction, the product was centrifuged, washed three times each with DMF and methanol, and activated under vacuum at 80 °C for 12 h to obtain the core-shell structured UiO-66-NH2@MSN-BTA.

[0044] Step S3: Superhydrophobic modification of the outer layer (F-UiO-66-NH2@MSN-BTA): Disperse 0.5g of the above core-shell powder in 50mL of anhydrous ethanol, add 0.6g of PFDTES dropwise, add 2mL of water, and adjust the pH to 4.5 with acetic acid to promote hydrolysis. Recirculate and stir the mixture in a 60℃ water bath for 6h. After the reaction is complete, centrifuge, wash twice with ethanol, dry at 60℃, and grind to obtain the final composite filler.

[0045] Example 5

[0046] The difference between this embodiment and Example 1 is that dodecyltrimethoxysilane is used instead of PFDTES.

[0047] A method for preparing an industrial anti-corrosion coating is as follows: Weigh 0.1g of anti-corrosion composite nanofiller and add it to 10g of xylene / n-butanol (volume ratio 7:3) mixed solvent, and ultrasonically disperse for 30min. Add the dispersion to 10g of E51 epoxy resin, and shear and stir at 1500r / min for 20min. Then add 2.5g of T31 curing agent, stir at low speed until uniform, and degas under vacuum.

[0048] The preparation method of the corrosion-resistant composite nanofiller is as follows:

[0049] Step S1: Core Loading (MSN-BTA): Weigh 1.0 g of mesoporous silica (MSN) and disperse it in 40 mL of benzotriazole (BTA) ethanol solution with a concentration of 50 mg / mL. Place the mixture in a vacuum reactor and degas it ultrasonically for 30 min under a vacuum of -0.09 MPa, followed by magnetic stirring under vacuum for 12 h. Centrifuge the mixture, quickly wash the surface of the precipitate once with 5 mL of anhydrous ethanol (to remove physically adsorbed BTA), and dry it under vacuum at 45 °C for 12 h to obtain MSN-BTA.

[0050] Step S2: Intermediate Shell Growth (UiO-66-NH2@MSN-BTA): 233 mg ZrCl4 and 181 mg H2BDC-NH2 were dissolved in 30 mL DMF, and 2 mL glacial acetic acid was added as a regulator. The mixture was ultrasonically dissolved to obtain a precursor solution. 0.5 g MSN-BTA was added to this solution and ultrasonically dispersed for 30 min. The mixture was transferred to a polytetrafluoroethylene-lined hydrothermal reactor and reacted at 120 °C for 24 h. After the reaction, the product was centrifuged, washed three times each with DMF and methanol, and activated under vacuum at 80 °C for 12 h to obtain the core-shell structured UiO-66-NH2@MSN-BTA.

[0051] Step S3: Superhydrophobic modification of the outer layer (F-UiO-66-NH2@MSN-BTA): Disperse 0.5g of the above core-shell powder in 50mL of anhydrous ethanol, add 0.6g of dodecyltrimethoxysilane dropwise, add 2mL of water, and adjust the pH to 4.5 with acetic acid to promote hydrolysis. Recirculate and stir the reaction mixture in a 60℃ water bath for 6h. After the reaction is complete, centrifuge, wash twice with ethanol, dry at 60℃, and grind to obtain the final composite filler.

[0052] Comparative Example 1

[0053] A method for preparing an industrial anti-corrosion coating is as follows: 10g of E51 epoxy resin is added to 10g of xylene / n-butanol (volume ratio 7:3) mixed solvent, and the mixture is sheared and stirred at 1500r / min for 20min. Then, 2.5g of T31 curing agent is added, and the mixture is stirred at low speed until homogeneous and then degassed under vacuum.

[0054] Comparative Example 2

[0055] Preparation of APTES-SiO2@GO: Nano-SiO2 was dispersed in ethanol, 10wt% APTES was added, the pH was adjusted to 4-5, and the reaction was carried out at 75℃ for 6 h, followed by centrifugation and drying. Graphene oxide (GO) was dispersed in DMF, modified SiO2 (mass ratio SiO2:GO = 1:6) was added, and the reaction was carried out at 105℃ for 6 h, followed by centrifugation and drying.

[0056] A method for preparing an industrial anti-corrosion coating is as follows: Weigh 0.1g of APTES-SiO2@GO and add it to 10g of a xylene / n-butanol (volume ratio 7:3) mixed solvent, and ultrasonically disperse for 30min. Add the dispersion to 10g of E51 epoxy resin, and shear and stir at 1500r / min for 20min. Then add 2.5g of T31 curing agent, stir at low speed until uniform, and degas under vacuum.

[0057] Comparative Example 3

[0058] A method for preparing an industrial anti-corrosion coating is as follows: Weigh 0.1g of anti-corrosion composite nanofiller and add it to 10g of xylene / n-butanol (volume ratio 7:3) mixed solvent, and ultrasonically disperse for 30min. Add the dispersion to 10g of E51 epoxy resin, and shear and stir at 1500r / min for 20min. Then add 2.5g of T31 curing agent, stir at low speed until uniform, and degas under vacuum.

[0059] The preparation method of the corrosion-resistant composite nanofiller is as follows:

[0060] Step S1: Core Loading (MSN-BTA): Weigh 1.0 g of mesoporous silica (MSN) and disperse it in 40 mL of benzotriazole (BTA) ethanol solution with a concentration of 50 mg / mL. Place the mixture in a vacuum reactor and degas it ultrasonically for 30 min under a vacuum of -0.09 MPa, followed by magnetic stirring under vacuum for 12 h. Centrifuge the mixture, quickly wash the surface of the precipitate once with 5 mL of anhydrous ethanol (to remove physically adsorbed BTA), and dry it under vacuum at 45 °C for 12 h to obtain MSN-BTA.

[0061] Step S2: Outer layer superhydrophobic modification (F-UiO-66-NH2@MSN-BTA): 0.5 g MSN-BTA was dispersed in 50 mL of anhydrous ethanol, 0.6 g PFDTES was added dropwise, followed by 2 mL of water. The pH was adjusted to 4.5 with acetic acid to promote hydrolysis. The reaction was refluxed and stirred at 60 °C for 6 h. After the reaction was completed, the mixture was centrifuged, washed twice with ethanol, dried at 60 °C, and ground to obtain the final composite filler.

[0062] Comparative Example 4

[0063] A method for preparing an industrial anti-corrosion coating is as follows: Weigh 0.1g of anti-corrosion composite nanofiller and add it to 10g of xylene / n-butanol (volume ratio 7:3) mixed solvent, and ultrasonically disperse for 30min. Add the dispersion to 10g of E51 epoxy resin, and shear and stir at 1500r / min for 20min. Then add 2.5g of T31 curing agent, stir at low speed until uniform, and degas under vacuum.

[0064] The preparation method of the corrosion-resistant composite nanofiller is as follows:

[0065] Step S1: Core Loading (MSN-BTA): Weigh 1.0 g of mesoporous silica (MSN) and disperse it in 40 mL of ethanol solution. Place the mixture in a vacuum reactor and degas it ultrasonically for 30 min under a vacuum of -0.09 MPa, followed by magnetic stirring under vacuum for 12 h. Centrifuge the mixture, quickly rinse the surface of the precipitate once with 5 mL of anhydrous ethanol, and dry it under vacuum at 45 °C for 12 h.

[0066] Step S2: Intermediate Shell Growth (UiO-66-NH2@MSN-BTA): 233 mg ZrCl4 and 181 mg H2BDC-NH2 were dissolved in 30 mL DMF, and 2 mL glacial acetic acid was added as a regulator. The mixture was sonicated to obtain a precursor solution. 0.5 g of the product from Step S1 was added to this solution and sonicated for 30 min. The mixture was transferred to a hydrothermal reactor lined with polytetrafluoroethylene and reacted at 120 °C for 24 h. After the reaction, the product was centrifuged, washed three times each with DMF and methanol, and activated under vacuum at 80 °C for 12 h to obtain the core-shell structured UiO-66-NH2@MSN.

[0067] Step S3: Superhydrophobic modification of the outer layer (F-UiO-66-NH2@MSN): Disperse 0.5g of the above core-shell powder in 50mL of anhydrous ethanol, add 0.6g of PFDTES dropwise, add 2mL of water, and adjust the pH to 4.5 with acetic acid to promote hydrolysis. Recirculate and stir the mixture in a 60℃ water bath for 6h. After the reaction is complete, centrifuge, wash twice with ethanol, dry at 60℃, and grind to obtain the final composite filler.

[0068] Comparative Example 5

[0069] A method for preparing an industrial anti-corrosion coating is as follows: Weigh 0.1g of anti-corrosion composite nanofiller and add it to 10g of xylene / n-butanol (volume ratio 7:3) mixed solvent, and ultrasonically disperse for 30min. Add the dispersion to 10g of E51 epoxy resin, and shear and stir at 1500r / min for 20min. Then add 2.5g of T31 curing agent, stir at low speed until uniform, and degas under vacuum.

[0070] The preparation method of the corrosion-resistant composite nanofiller is as follows:

[0071] Step S1: Core Loading (MSN-BTA): Weigh 1.0 g of mesoporous silica (MSN) and disperse it in 40 mL of benzotriazole (BTA) ethanol solution with a concentration of 50 mg / mL. Place the mixture in a vacuum reactor and degas it ultrasonically for 30 min under a vacuum of -0.09 MPa, followed by magnetic stirring under vacuum for 12 h. Centrifuge the mixture, quickly wash the surface of the precipitate once with 5 mL of anhydrous ethanol (to remove physically adsorbed BTA), and dry it under vacuum at 45 °C for 12 h to obtain MSN-BTA.

[0072] Step S2: Intermediate Shell Growth (ZIF-8@MSN-BTA): 0.5 g MSN-BTA was dispersed in 40 mL of methanol solution containing 1.17 g Zn(NO3)26H2O; 2.6 g 2-methylimidazole was dissolved in 40 mL of methanol, and the two solutions were mixed to obtain a precursor solution. 0.5 g MSN-BTA was added to this solution and ultrasonically dispersed for 30 min. The mixture was transferred to a hydrothermal reactor lined with polytetrafluoroethylene and reacted at 120 °C for 24 h. After the reaction, the product was centrifuged, washed three times each with DMF and methanol, and activated under vacuum at 80 °C for 12 h to obtain the core-shell structured ZIF-8@MSN-BTA.

[0073] Step S3: Superhydrophobic modification of the outer layer (F-ZIF-8@MSN-BTA): Disperse 0.5g of the above core-shell powder in 50mL of anhydrous ethanol, add 0.6g of PFDTES dropwise, add 2mL of water, and adjust the pH to 4.5 with acetic acid to promote hydrolysis. Recirculate and stir the mixture in a 60℃ water bath for 6h. After the reaction is complete, centrifuge, wash twice with ethanol, dry at 60℃, and grind to obtain the final composite filler.

[0074] Test case

[0075] Adhesion testing was conducted according to ASTM D4541, with a loading rate of 1 MPa / s. Impact performance testing was conducted according to ASTM D2794. Tensile performance testing was conducted according to ASTM D638, with a test speed of 10 mm / min and a test temperature of 23 ± 2°C. Abrasion resistance testing used the Taber test method. The weight change of the specimen before and after 200 friction cycles under a certain pressure condition was measured (initial weight m1 minus weight after wear m2) to obtain the wear mass loss. All mechanical property tests were performed using a set of three specimens, and the test results were averaged. The test results are shown in Table 1.

[0076] Table 1 Performance Tests.

[0077]

[0078] The pencil of Example 1 has a hardness of 5H and a wear amount of 385mg, which is better than that of Comparative Example 2 (4H and 620mg).

[0079] While SiO2@GO can enhance hardness, interlayer slippage may occur in the two-dimensional layers under high wear. In this invention, the UiO-66-NH2 shell forms a chemical cross-link with the epoxy resin matrix (amino groups participate in curing), and the mesoporous silica core provides rigid support, resulting in a significant "pinning effect" that greatly improves the coating's scratch resistance and wear resistance. Example 1 showed improved adhesion to 6.45 MPa and tensile strength as high as 92.4 MPa, significantly better than Comparative Example 2 (4.03 MPa and 78.6 MPa). Although the GO material was modified, it mainly relied on van der Waals forces and physical interlocking. In contrast, the UiO-66-NH2 surface used in this invention is rich in active amino groups (-NH2), which can directly react with the epoxy groups in the epoxy resin to form strong covalent bonds. This "molecular-level" interfacial bonding eliminates micro-defects at the organic / inorganic interface, thereby significantly improving adhesion and tensile strength. The mechanical properties of the ZIF-8 coating (adhesion 5.20 MPa, tensile strength 79.4 MPa) are better than pure epoxy, but not as good as those of Example 1. The ZIF-8 surface lacks highly active amino functional groups like UiO-66-NH2, and its bonding with the resin matrix mainly relies on physical interactions, resulting in weak interfacial strength and limited improvement in mechanical properties. Comparative Example 4 (without BTA): The mechanical properties are almost identical to those of Example 1 (e.g., tensile strength 92.8 MPa vs 92.4 MPa), indicating that the core-loaded BTA has minimal impact on the mechanical strength of the coating and does not affect the structural integrity of the coating. Comparative Example 3 (without shell): Due to the lack of MOF shell encapsulation, the interfacial bonding between the nanofiller and the resin decreases (no amino crosslinking), resulting in significantly lower adhesion and tensile strength (4.80 MPa, 72.5 MPa) compared to Example 1.

Claims

1. An industrial anti-corrosion coating, characterized in that, The coating comprises a film-forming resin, a curing agent, an organic solvent, and an anti-corrosion composite nanofiller. The anti-corrosion composite nanofiller has a three-layer structure: the core is mesoporous silica loaded with an organic corrosion inhibitor; the middle shell is an in-situ grown amino-functionalized metal-organic framework material; and the outer layer is a low surface energy layer formed by modification with a hydrophobic modifier. The amino-functionalized metal-organic framework material is an amino-functionalized zirconium-based metal-organic framework material UiO-66-NH2; UiO-66-NH2 is formed by the self-assembly of zirconium salt and 2-aminoterephthalic acid on the surface of the core. The hydrophobic modifier is a fluorinated silane or a long-chain alkyl silane; The film-forming resin is bisphenol A type epoxy resin; the curing agent is an amine-based curing agent; The corrosion-resistant composite nanofiller undergoes a chemical cross-linking reaction with the film-forming resin through the amino groups on the surface of the intermediate shell.

2. The industrial anti-corrosion coating according to claim 1, characterized in that, The mesoporous silica has an average particle size of 80-200 nm and a pore size of 2-10 nm; the organic corrosion inhibitor is selected from at least one of benzotriazole, 8-hydroxyquinoline, 2-mercaptobenzothiazole or imidazoline derivatives.

3. The industrial anti-corrosion coating according to claim 1, characterized in that, The fluorinated silane is selected from at least one of perfluorooctyltriethoxysilane, heptadecafluorodecyltrimethoxysilane, or perfluorododecyltriethoxysilane; the long-chain alkyl silane is selected from at least one of dodecyltrimethoxysilane or hexadecyltrimethoxysilane.

4. The industrial anti-corrosion coating according to any one of claims 1 to 3, characterized in that, The corrosion-resistant composite nanofiller The amount added to the coating is 0.5% to 3.0% of the mass of the film-forming resin.

5. A method for preparing an industrial anti-corrosion coating as described in claim 1, characterized in that, Includes the following steps: (1) Disperse mesoporous silica in an organic corrosion inhibitor solution, stir under vacuum, load the organic corrosion inhibitor into the mesoporous channels using negative pressure, separate and dry to obtain mesoporous silica loaded with corrosion inhibitor; (2) Disperse the product obtained in step (1) in a precursor solution containing metal salt and organic ligand, carry out an in-situ growth reaction under solvothermal conditions, and coat the surface with an amino-functionalized metal-organic framework material shell; (3) Disperse the product obtained in step (2) in a solvent, add a hydrophobic modifier to carry out a grafting reaction, and dry to obtain an anti-corrosion composite nanofiller; (4) Disperse the anti-corrosion composite nanofiller in a solvent, mix it with a film-forming resin, add a curing agent, stir evenly to obtain the industrial anti-corrosion coating.

6. The preparation method according to claim 5, characterized in that, The metal salt in step (2) is zirconium tetrachloride, and the organic ligand is 2-aminoterephthalic acid; the reaction temperature under the solvothermal conditions is 100~140℃, and the reaction time is 12~36 hours.

7. The preparation method according to claim 6, characterized in that, The mass ratio of the hydrophobic modifier in step (3) to the product obtained in step (2) is (0.5~1.5):1; the grafting reaction is carried out under the condition of pH 4~5 and the reaction temperature is 50~80℃.

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