Efficient anticorrosive paint and preparation method thereof

Abstract

The invention discloses an efficient anticorrosive coating and a preparation method thereof, and relates to the technical field of coatings. The high-efficiency anticorrosive paint is prepared from a crosslinked membrane modified phytic acid loaded aluminum MCM-41 mesoporous silica composite synergistic filler, a polyurethane / epoxy resin composite emulsion system, titanium dioxide, a BYK-190 dispersing agent, a BYK-021 defoaming agent, a BYK-358N flatting agent, a BYK-425 thickening agent, hydroxyethyl cellulose and deionized water. A cross-linked membrane modified phytic acid loaded aluminum MCM-41 mesoporous silica composite synergistic filler is uniformly dispersed and deeply embedded into a polyurethane / epoxy resin composite emulsion system, countless chemical anchor points are established between the filler and a base material, and the interface bonding property with a resin system is also enhanced, so that the adhesive force of the coating is greatly improved, and meanwhile, the coating has the advantages that the service life of the coating is prolonged, and the service life of the coating is prolonged. And an active and passive three-dimensional protection system formed by the two is used for remarkably improving the corrosion resistance of the coating in the action modes of intelligent response, active repair and physical barrier.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of coatings, and particularly relates to a high-efficiency anticorrosive coating and a preparation method thereof. BACKGROUND

[0002] Metals are widely used in industrial production and human life, and are easily corroded in air and water and the like, and the corrosion mechanism is very complex, and the material change and structure damage caused by corrosion are irreversible, which causes serious harm to the environment and economy; at present, the main means of corrosion prevention include corrosion inhibitors, electrochemical corrosion prevention, and coating corrosion prevention, etc., among which, coating corrosion prevention can isolate corrosive media and inhibit the occurrence of corrosion, and is widely applied due to the advantages of easy construction and good protection performance.

[0003] The prior art mainly has the following problems:

[0004] The adhesion of the coating cured by the traditional coating is poor, which further limits the play of the anticorrosive effect, and excellent anticorrosive performance cannot be achieved. SUMMARY

[0005] In view of the above problems, the application provides a high-efficiency anticorrosive coating, which comprises the following components in parts by weight: 10-20 parts of cross-linked membrane modified phytic acid@aluminum-loaded MCM-41 mesoporous silica composite synergistic filler, 40-60 parts of polyurethane / epoxy resin composite emulsion system, 15-20 parts of titanium white, 0.3-0.5 parts of BYK-190 dispersant, 0.2-0.4 parts of BYK-021 defoaming agent, 0.2-0.4 parts of BYK-358N leveling agent, 0.2-0.4 parts of BYK-425 thickening agent, 0.3-0.5 parts of hydroxyethyl cellulose, and 15-20 parts of deionized water.

[0006] The cross-linked membrane modified phytic acid@aluminum-loaded MCM-41 mesoporous silica composite synergistic filler comprises the following components in parts by weight: 10-20 parts of phytic acid@aluminum-loaded MCM-41 mesoporous silica powder, 1-3 parts of polyethyleneimine, 1-3 parts of sodium poly (p-styrenesulfonate), and 0.12-0.40 parts of glutaraldehyde.

[0007] The preparation method of the cross-linked membrane modified phytic acid@aluminum-loaded MCM-41 mesoporous silica composite synergistic filler comprises the following steps:

[0008] (1) 1.0-2.0 g MCM-41 mesoporous silica is added to 50 mL of n-hexane solvent treated by 3A molecular sieve, stirred for 10-20 min to form mixture I for standby, then 150 mL of n-hexane solvent treated by 3A molecular sieve is added to aluminum isopropyl alcohol, stirred for 10-20 min to form mixture II for standby, mixture I is added to mixture II under the stirring speed of 500-600 rpm, after the addition is completed, continue to stir for 10-20 min, seal and stand at room temperature for 24 h, vacuum filtration, the solid is washed 2-3 times with 100 mL of n-hexane solvent which has been dried, first dried at room temperature for 12 h, then put into a muffle furnace and calcined at 500-550°C for 2-4 h, to obtain aluminum-loaded MCM-41 mesoporous silica, the aluminum center reaction site introduced by the aluminum-loaded modification treatment of MCM-41 mesoporous silica enhances the interface bonding force of the filler and the resin and the base material, reduces the phase separation and micro defects caused by poor compatibility, not only improves the adhesion and adhesion stability, but also improves the corrosion resistance, and also lays a foundation for subsequent high loading and stable anchoring of phytic acid;

[0009] (2) 0.1-0.3 g of the aluminum-loaded MCM-41 mesoporous silica described in step (1) is dispersed in 20 mL of anhydrous ethanol to form a dispersion liquid for standby, then a phytic acid solution with a mass fraction of 50% is adjusted to pH 4.0-5.0 with ammonia water, and then added to the dispersion liquid, stirred at 20°C for 2-3 h, washed with anhydrous ethanol and deionized water alternately for 3 times, the collected precipitate is vacuum dried at 60°C for 12 h to obtain phytic acid@aluminum-loaded MCM-41 mesoporous silica powder, the phytic acid is anchored inside and on the surface of the aluminum-loaded MCM-41 mesoporous silica by a firm Al-O-P coordination bond, when the local microenvironment pH changes due to coating solidification, coating damage, corrosion initiation, etc., the coordination bond is broken, and the released phytic acid quickly migrates to the exposed metal surface, its multiple phosphoric acid groups strongly complex with metal ions, forming a dense and stable insoluble phytic acid-metal protective film on the metal surface, not only locking the coating on the metal surface and enhancing the adhesion after the coating is solidified, but also effectively blocking the corrosion medium and actively inhibiting the continuation of the corrosion reaction, thereby improving the corrosion resistance through the targeted self-repairing corrosion prevention mode;

[0010] (3) The phytic acid loaded aluminum MCM-41 mesoporous silica powder of step (2) is weighed 1.0-2.0 g and added to 80-100 mL of anhydrous ethanol, then polyethyleneimine is added, stirred for 30-40 min, then sodium polystyrene sulfonate is added, stirred for 20-30 min, to form a suspension for use, 10 mL of a 25% by mass glutaraldehyde aqueous solution is removed of water by rotary evaporation, then diluted with anhydrous ethanol to a 3-5% by mass glutaraldehyde alcohol solution for use, then ammonia water is added dropwise to adjust the pH of the suspension to 8.0-9.0, under stirring at a speed of 3000-4000 rpm, 0.5-1.0 mL of the glutaraldehyde alcohol solution is added to the suspension, warmed to 40-50°C, stirred for 4-6 h, centrifuged, the precipitate is collected and washed with anhydrous ethanol 3-5 times, vacuum dried at 60°C for 8 h, to obtain a cross-linked membrane modified phytic acid loaded aluminum MCM-41 mesoporous silica composite synergistic filler, glutaraldehyde as a bifunctional cross-linking agent, the loose polyethyleneimine and sodium polystyrene sulfonate polyelectrolyte bilayer shell is stitched into a solid, dense, three-dimensional cross-linked membrane, with high mechanical strength and toughness, thereby improving the cohesive strength and modulus of the coating, effectively reducing the peeling of the coating from the metal substrate after curing, and the polar groups such as amine groups and sulfonic acid groups on the shell form strong hydrogen bonds and dipole-dipole interactions with the resin, improving the interfacial compatibility and bonding between the two, also conducive to enhancing the adhesion, the cross-linked membrane formed by glutaraldehyde further bends and blocks the penetration path of corrosion media such as water, oxygen and chloride ions, eliminating the interfacial defects between the filler and the resin, making it more difficult for the corrosion medium to penetrate through the interfacial channel, enhancing the overall shielding performance and corrosion resistance of the coating;

[0011] Preferably, in step (1), the amount of aluminum isopropoxide added is 0.2-0.3 g, the aluminum center as a Lewis acid site can form a coordination bond or a weak chemical bond with the oxide layer or hydroxyl group on the surface of the metal substrate, thereby enhancing the bridging effect of the filler with the substrate, also producing stronger dipole-dipole interactions with the polar groups in the resin, improving the compatibility and bonding force of the filler in the resin matrix, reducing the micropore defects at the interface, thereby enhancing the overall corrosion barrier effect;

[0012] Preferably, in step (2), the amount of phytic acid solution added is 0.3-0.4 g, the phosphate groups of the phytic acid molecules can not only undergo strong coordination reactions with metal ions, but also form strong hydrogen bond networks with the polar groups of epoxy resin and polyurethane resin, improving the interfacial compatibility and bonding force between the filler and the resin matrix, enhancing the cohesive strength of the coating, thereby better resisting the stress of peeling from the substrate;

[0013] Preferably, in step (3), the amount of polyethyleneimine added is 0.1-0.3g, and the amount of sodium poly (p-styrenesulfonate) added is 0.1-0.3g. The polyethyleneimine and sodium poly (p-styrenesulfonate) can form a polyelectrolyte bilayer shell through electrostatic adsorption, which not only provides a strong defense line for the penetration of corrosive media, but also enables the filler to be more uniformly dispersed in the resin, and prevents the premature leakage of phytic acid. Under corrosive or acidic conditions, the polyethyleneimine and sodium poly (p-styrenesulfonate) are protonated, the polyelectrolyte bilayer shell is opened, and then the phytic acid is released to act on the corrosion point, making the corrosion prevention more durable and efficient.

[0014] The application also provides a preparation method of the high-efficiency anticorrosive coating.

[0015] S1, after water removal, polyethylene glycol PEG-1000, toluene diisocyanate and 100-200mL of acetone are added into a reaction kettle, nitrogen is introduced for protection, the temperature is raised to 70-75℃, and reaction is carried out for 3-4h to ensure that the conversion rate of -NCO in the reaction process is above 98%. 10.5-12.5g of 2,2-bishydroxymethylpropionic acid is first dissolved in 50mL of acetone, and then added into the reaction kettle, and reaction is continued for 1.5-2.5h to ensure that the conversion rate of -NCO in the reaction process is above 98%. Then 40-50g of bisphenol A type epoxy resin and 100-120mL of acetone are added, the temperature is raised to 80-85℃, and reaction is carried out for 5-6h. After the reaction is completed, the temperature is lowered to 45℃, 13-17mL of triethylamine is added for neutralization, and finally 500-700mL of deionized water is added for high-speed dispersion at a speed of 2000-3000rpm for 10-20min. After pressure reduction distillation, a polyurethane / epoxy resin composite emulsion system is obtained. In this process, polyethylene glycol PEG-1000 serves as a soft segment to provide flexibility and elasticity, and toluene diisocyanate serves as a hard segment to provide extremely high cohesive strength and hardness. The rigid-flexible microphase separation structure formed by the two avoids the defects of brittle cracking of pure epoxy resin and insufficient strength of pure flexible glue, thereby realizing durable and strong adhesion. The polyurethane main chain skeleton constructed by the two and the epoxy resin together form a dense, cross-linked and strong coating film structure, which not only effectively prolongs the penetration path of corrosive media such as water, oxygen and chloride ions, but also better resists scratches, impacts, abrasion and low temperature damage, and through a complete and stable barrier effect, the starting point of corrosion is eliminated from the source;

[0016] S2, hydroxyethyl cellulose, deionized water is added to a high-speed blender, stirring at 300-500 rpm speed until completely dissolved, then at 500-800 rpm speed, adding BYK-190 dispersant, titanium dioxide, cross-linked membrane modified phytic acid@aluminum-loaded MCM-41 mesoporous silica composite synergistic filler in turn for pre-dispersion treatment, adjusting the stirring speed to 2000-2500 rpm, stirring time 10-20 min, forming a uniform slurry, then reducing the speed to 800-1000 rpm, adding the polyurethane / epoxy resin composite emulsion system described in step S1, stirring for 20-30 min, then adding BYK-021 defoamer, BYK-358N leveling agent and BYK-425 thickener, continue to disperse for 20-30 min, finally transfer the material to a horizontal sand mill for circulation grinding, ensure that the fineness of the particles is not more than 25μm, after grinding, filter with 100-200 mesh screen, get high-efficiency anticorrosive coating, the polyurethane / epoxy resin composite emulsion system as the continuous phase and the bonding framework of the coating, the cross-linked membrane modified phytic acid@aluminum-loaded MCM-41 mesoporous silica composite synergistic filler, functional pigment and adjuvant are bonded into a whole, forming a multi-phase composite coating structure, not only realizing the persistent and high-strength adhesion, but also significantly improving the corrosion resistance through the multi-layer defense mechanism of intelligent response, active repair and physical barrier constructed.

[0017] Preferably, in step S1, the adding amount of polyethylene glycol PEG-1000 and toluene diisocyanate is 100-150g and 50-60g respectively, the hydrophilicity and flexibility of polyethylene glycol PEG-1000 segment help the coating to better wet the metal surface and penetrate into the micro-pores of the substrate, enhancing the mechanical anchoring effect, and the residual isocyanate groups of toluene diisocyanate form chemical bonding with the metal surface during the curing process of the coating, enhancing the adhesion stability of the coating.

[0018] The beneficial effects obtained by the present application are as follows:

[0019] The application greatly improves the adhesion of the coating by uniformly dispersing and deeply embedding the cross-linked membrane modified phytic acid loaded aluminum MCM-41 mesoporous silica composite synergistic filler in the polyurethane / epoxy resin composite emulsion system, not only establishing numerous chemical anchors between the filler and the substrate, but also enhancing the interface bonding with the resin system; meanwhile, the active and passive three-dimensional protection system formed by the two components significantly improves the corrosion resistance of the coating by means of intelligent response, active repair and physical barrier; in the cross-linked membrane modified phytic acid loaded aluminum MCM-41 mesoporous silica composite synergistic filler, the aluminum loaded MCM-41 mesoporous silica is used as the core framework, the phytic acid is fixed in the mesoporous channel and on the surface, and then a double-molecule cross-linked membrane is constructed on the surface of the phytic acid loaded aluminum MCM-41 mesoporous silica powder by layer-by-layer self-assembly, which plays the role of intelligent controlled release membrane and reinforced physical barrier, not only ensuring the stability of the phytic acid, the intelligent release property and the overall structure, realizing the synergistic effect of the physical barrier and the phytic acid active repair, being beneficial to providing long-term and efficient and precise corrosion protection, but also improving the cohesive strength and modulus of the coating, effectively reducing the peeling of the coating from the metal substrate after curing, wherein the phytic acid metal protection film formed by the multiple phosphoric acid groups of the phytic acid on the metal surface acts as a bridge, chemically bonding to the metal surface on one side and interacting with the filler and the resin matrix on the other side, thereby enhancing the adhesion of the coating; in the polyurethane / epoxy resin composite emulsion system, the long-chain flexible polyethylene glycol PEG-1000 reacts with the rigid toluene diisocyanate to generate a linear prepolymer characterized by urethane bond and having high active isocyanate groups at both ends, and finally a composite emulsion with a polyurethane-epoxy resin graft interpenetrating network structure is formed, wherein the epoxy resin provides a hard skeleton and high polarity, generates strong van der Waals force and hydrogen bond with the metal substrate, lays the foundation for the initial adhesion, and the polyurethane as a flexible segment endows the coating with elasticity and toughness, effectively absorbs and releases stress, prevents brittle cracking and peeling of the coating caused by temperature difference change or substrate deformation, ensures the durability of the adhesion, and further blocks the invasion and penetration of the corrosion medium by constructing a high-crosslinked, dense and tough polymer network structure, thereby enhancing the corrosion protection barrier effect; the cross-linked membrane modified phytic acid loaded aluminum MCM-41 mesoporous silica composite synergistic filler, the polyurethane / epoxy resin composite emulsion system, titanium white, BYK-190 dispersant, BYK-021 defoamer, BYK-358N leveling agent, BYK-425 thickening agent, hydroxyethyl cellulose and deionized water are used to prepare a high-efficiency corrosion-resistant coating, which effectively improves the adhesion of the coating and significantly improves the corrosion resistance of the coating. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 The scanning electron microscope image of the high-efficiency corrosion-resistant coating prepared in Example 1 of the application;

[0021] Figure 2 The adhesion results chart of the present application examples 1-4 and comparative examples 1-3;

[0022] Figure 3 The corrosion maximum length results chart of the present application examples 1-4 and comparative examples 1-3. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present application will be clearly and completely described in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application; based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative labor fall within the protection scope of the present application.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by one of ordinary skill in the art. In addition, any method and material similar or equivalent to those described herein can be used in the present application. The preferred implementation methods and materials described herein are only used for demonstration, but cannot limit the content of the present application.

[0025] The experimental methods in the following embodiments are all conventional methods unless otherwise specified; the experimental materials used in the following embodiments are all purchased from commercial channels unless otherwise specified.

[0026] Example 1

[0027] The present embodiment proposes a high-efficiency anticorrosive coating, which comprises the following components in parts by weight: cross-linked membrane modified phytic acid@aluminum-loaded MCM-41 mesoporous silica composite synergistic filler 20 parts, polyurethane / epoxy resin composite emulsion system 60 parts, titanium white 20 parts, BYK-190 dispersant 0.5 parts, BYK-021 defoaming agent 0.4 parts, BYK-358N leveling agent 0.4 parts, BYK-425 thickening agent 0.4 parts, hydroxyethyl cellulose 0.5 parts, and deionized water 20 parts.

[0028] The cross-linked membrane modified phytic acid@aluminum-loaded MCM-41 mesoporous silica composite synergistic filler comprises the following components in parts by weight: phytic acid@aluminum-loaded MCM-41 mesoporous silica powder 20 parts, polyethyleneimine 3 parts, poly (p-phenylene sulfonic acid) sodium 3 parts, and glutaraldehyde 0.40 part.

[0029] The preparation method of the cross-linked membrane modified phytic acid@aluminum-loaded MCM-41 mesoporous silica composite synergistic filler specifically comprises the following steps:

[0030] (1) 2.0 g of MCM-41 mesoporous silica is added to 50 mL of n-hexane solvent treated by 3A molecular sieve, stirred for 20 min to form mixture I for standby, then 0.3 g of aluminum isopropoxide is added to 150 mL of n-hexane solvent treated by 3A molecular sieve, stirred for 20 min, the amount of aluminum isopropoxide added is 0.3 g, the aluminum center as a Lewis acid site can form a coordination bond or a weak chemical bond with the oxide layer or hydroxyl group on the surface of the metal substrate, thereby enhancing the bridging effect of the filler and the substrate, and also producing stronger dipole-dipole interaction with the polar groups in the resin, improving the compatibility and binding force of the filler in the resin matrix, reducing the micropore defects at the interface, thereby enhancing the overall corrosion protection barrier effect, mixture II is formed for standby, mixture I is added to mixture II under the stirring speed of 600 rpm, after the addition is completed, continue to stir for 20 min, seal and stand at room temperature for 24 h, vacuum filtration, the solid is washed 3 times with 100 mL of n-hexane solvent which has been dried, first dried at room temperature for 12 h, then placed in a muffle furnace and calcined at 550°C for 4 h to obtain aluminum-loaded MCM-41 mesoporous silica, the aluminum-loaded modification treatment of MCM-41 mesoporous silica introduces aluminum center reaction sites, enhances the interface bonding force of the filler and the resin and the substrate, reduces the phase separation and micro defects caused by poor compatibility, not only improves the adhesion and adhesion stability, but also improves the corrosion resistance, at the same time, it also lays a foundation for subsequent high loading and stable anchoring of phytic acid;

[0031] (2) 0.3 g of the aluminum-loaded MCM-41 mesoporous silica described in step (1) is weighed and dispersed in 20 mL of anhydrous ethanol to form a dispersion liquid for use. A phytic acid solution with a mass fraction of 50% is adjusted to a pH of 5.0 with ammonia water, and the amount of the phytic acid solution added is 0.4 g. The phosphoric acid groups of the phytic acid molecules can not only have a strong coordination reaction with metal ions, but also form a strong hydrogen bond network with the polar groups of epoxy resin and polyurethane resin, thereby improving the interfacial compatibility and binding force between the filler and the resin matrix and enhancing the cohesive strength of the coating, so as to better resist the stress of peeling off from the substrate. Then, the dispersion liquid is added, and stirring is performed at 20°C for 3 h. The collected precipitate is washed with anhydrous ethanol and deionized water alternately for 3 times, and then vacuum dried at 60°C for 12 h to obtain a phytic acid@aluminum-loaded MCM-41 mesoporous silica powder. The phytic acid is anchored inside and on the surface of the aluminum-loaded MCM-41 mesoporous silica through a strong Al-O-P coordination bond. When the coating is cured, the coating layer is damaged, corrosion begins, and the local microenvironment pH changes, the coordination bond is broken, and the released phytic acid quickly migrates to the exposed metal surface. The multiple phosphoric acid groups of the phytic acid strongly complex with metal ions to form a dense, stable and insoluble phytic acid-metal protective film on the metal surface, which not only locks the coating on the metal surface and enhances the adhesion of the cured coating, but also effectively blocks the corrosion medium and actively inhibits the continuation of the corrosion reaction, thereby improving the corrosion resistance through the targeted self-repairing corrosion protection mode;

[0032] (3) 2.0 g of the phytic acid-aluminum-loaded MCM-41 mesoporous silica powder described in step (2) is weighed into 100 mL of anhydrous ethanol, followed by the addition of polyethyleneimine, stirring for 40 min, and then the addition of sodium polystyrene sulfonate, stirring for 30 min. The amount of polyethyleneimine added is 0.3 g, and the amount of sodium polystyrene sulfonate added is 0.3 g. The polyethyleneimine and the sodium polystyrene sulfonate can form a polyelectrolyte bilayer shell through electrostatic adsorption, which not only provides a strong defense line against the penetration of corrosive media, but also enables the filler to be more uniformly dispersed in the resin, and also prevents the premature leakage of phytic acid. Under corrosive or acidic conditions, the polyethyleneimine and the sodium polystyrene sulfonate undergo protonation, the polyelectrolyte bilayer shell opens, and then the phytic acid is released to act on the corrosion sites, making the corrosion prevention more durable and efficient. A 10 mL aqueous solution of glutaraldehyde with a mass fraction of 25% is removed of water by rotary evaporation, and then diluted with anhydrous ethanol to form a 5% glutaraldehyde alcohol solution. Then, ammonia water is added dropwise to adjust the pH of the suspension to 9.0. Under stirring at a speed of 4000 rpm, 1.0 mL of the glutaraldehyde alcohol solution is added to the suspension, which is heated to 50°C and stirred for 6 h. The precipitate is collected by centrifugation and washed with anhydrous ethanol 5 times, and then dried at 60°C under vacuum for 8 h to obtain a cross-linked membrane-modified phytic acid-aluminum-loaded MCM-41 mesoporous silica composite synergistic filler. Glutaraldehyde, as a bifunctional cross-linking agent, stitches the polyelectrolyte bilayer shell of loose polyethyleneimine and sodium polystyrene sulfonate into a strong, dense, three-dimensional cross-linked membrane, which has high mechanical strength and toughness, thereby improving the cohesive strength and modulus of the coating, effectively reducing the peeling of the coating from the metal substrate after curing, and the polar groups such as amine groups and sulfonic acid groups on the shell form strong hydrogen bonds and dipole-dipole interactions with the resin, improving the interfacial compatibility and bonding between the two, which also helps to enhance the adhesion. The cross-linked membrane formed by glutaraldehyde further twists and blocks the penetration path of corrosive media such as water, oxygen, and chloride ions, eliminating the interfacial defects between the filler and the resin, making it more difficult for corrosive media to penetrate through the interfacial channel, and enhancing the overall shielding performance and corrosion resistance of the coating.

[0033] The embodiment provides a preparation method of a high-efficiency anticorrosive coating, specifically including the following steps.

[0034] S1, polyethylene glycol PEG-1000, toluene diisocyanate and 200 mL of acetone after water removal were added to the reaction kettle, the adding amount of polyethylene glycol PEG-1000 and toluene diisocyanate was 150 g, 60 g respectively, the hydrophilicity and flexibility of polyethylene glycol PEG-1000 segment helped the paint to wet the metal surface better, and penetrated into the micro pores of the substrate, enhanced the mechanical anchoring effect, toluene diisocyanate formed chemical bond with metal surface in the process of paint curing, enhanced the adhesion stability of paint, nitrogen was blown in for protection, the temperature was raised to 75℃, and the reaction was carried out for 4h, to ensure that the conversion rate of-NCO in the reaction process was more than 98%, 12.5g 2,2-bishydroxymethyl propionic acid was dissolved in 50mL acetone first, then added to the reaction kettle, and the reaction was continued for 2.5h, to ensure that the conversion rate of-NCO in the reaction process was more than 98%, then 50g bisphenol A type epoxy resin and 120mL acetone were added, the temperature was raised to 85℃, and the reaction was carried out for 6h, after the reaction was completed, the temperature was reduced to 45℃, 17mL triethylamine was added for neutralization, finally 700mL deionized water was added, and high speed dispersion was carried out at 3000rpm for 20min, vacuum distillation was carried out, polyurethane / epoxy resin composite emulsion system was obtained, in this process, polyethylene glycol PEG-1000 as soft segment provided flexibility and elasticity, toluene diisocyanate as hard segment provided high cohesive strength and hardness, the rigid-flexible micro phase separation structure formed by the two avoided the defects of brittle cracking of pure epoxy resin and insufficient strength of pure flexible glue, so as to realize the persistent and strong adhesion, the polyurethane main chain skeleton constructed by the two and epoxy resin together formed a dense, crosslinked, strong and tough coating film structure, not only effectively prolonged the penetration path of corrosion medium such as water, oxygen and chloride ion, but also better resisted scratching, impact, wear and low temperature damage, through the complete and stable barrier effect, the starting point of corrosion was eliminated from the source;

[0035] S2, hydroxyethyl cellulose, deionized water into a high-speed mixer, stirring to complete dissolution at 500 rpm speed, then at 800 rpm speed, adding BYK-190 dispersant, titanium dioxide, cross-linked membrane modified phytic acid@aluminum-loaded MCM-41 mesoporous silica composite synergistic filler in turn for pre-dispersion treatment, adjusting the stirring speed to 2500 rpm, stirring for 20 min, forming a uniform slurry, then reducing the speed to 1000 rpm, adding the polyurethane / epoxy resin composite emulsion system described in step S1, stirring for 30 min, then adding BYK-021 defoamer, BYK-358N leveling agent and BYK-425 thickener, continuing to disperse for 30 min, finally transferring the material to a horizontal sand mill for circulation grinding, ensuring that the fineness of the particles is not more than 25 μm, after grinding, filtering with a 200 mesh screen, obtaining a high-efficiency anticorrosive coating, the polyurethane / epoxy resin composite emulsion system as the continuous phase and the binding framework of the coating, the cross-linked membrane modified phytic acid@aluminum-loaded MCM-41 mesoporous silica composite synergistic filler, functional pigments and auxiliaries are bound into a whole, forming a multi-phase composite coating structure, not only realizing long-lasting and high-strength adhesion, but also significantly improving the corrosion resistance through the constructed multi-layer defense mechanism of intelligent response, active repair and physical barrier.

[0036] In this embodiment, the prepared high-efficiency anticorrosive coating is observed by scanning electron microscopy to observe its micro-morphology, Figure 1 The SEM image of the high-efficiency anticorrosive coating prepared in Example 1 is magnified 2000 times, as shown in Figure 1 The interface bonding of the high-efficiency anticorrosive coating prepared in this embodiment is good.

[0037] Example 2

[0038] This embodiment proposes a high-efficiency anticorrosive coating, which comprises the following components by weight: cross-linked membrane modified phytic acid@aluminum-loaded MCM-41 mesoporous silica composite synergistic filler 10 parts, polyurethane / epoxy resin composite emulsion system 40 parts, titanium dioxide 15 parts, BYK-190 dispersant 0.3 parts, BYK-021 defoamer 0.2 parts, BYK-358N leveling agent 0.2 parts, BYK-425 thickener 0.2 parts, hydroxyethyl cellulose 0.3 parts, deionized water 15 parts.

[0039] The cross-linked membrane modified phytic acid@aluminum-loaded MCM-41 mesoporous silica composite synergistic filler comprises the following components by weight: phytic acid@aluminum-loaded MCM-41 mesoporous silica powder 10 parts, polyethyleneimine 1 part, poly (p-phenylene sulfonic acid) sodium 1 part, glutaraldehyde 0.12 part.

[0040] The preparation method of the cross-linked membrane modified phytic acid@aluminum-loaded MCM-41 mesoporous silica composite synergistic filler comprises the following steps:

[0041] (1) 1.0 g of MCM-41 mesoporous silica is added to 50 mL of n-hexane solvent treated by 3A molecular sieve, stirred for 10 min to form mixture I for standby, then 0.2 g of aluminum isopropoxide is added to 150 mL of n-hexane solvent treated by 3A molecular sieve, stirred for 10 min, the amount of aluminum isopropoxide added is 0.2 g, the aluminum center as a Lewis acid site can form a coordination bond or a weak chemical bond with the oxide layer or hydroxyl group on the surface of the metal substrate, thereby enhancing the bridging effect of the filler and the substrate, and also producing stronger dipole-dipole interaction with the polar groups in the resin, improving the compatibility and binding force of the filler in the resin matrix, reducing the micropore defects at the interface, thereby enhancing the overall corrosion protection barrier effect, mixture II is formed for standby, mixture I is added to mixture II under a stirring speed of 500 rpm, after the addition is completed, continue to stir for 10 min, seal and stand at room temperature for 24 h, vacuum filtration, the solid is washed twice with 100 mL of n-hexane solvent which has been dried, first dried at room temperature for 12 h, then placed in a muffle furnace and calcined at 500°C for 2 h to obtain aluminum-loaded MCM-41 mesoporous silica, the aluminum-loaded modification treatment of MCM-41 mesoporous silica introduces aluminum center reaction sites, enhances the interfacial bonding force of the filler and the resin and the substrate, reduces the phase separation and micro defects caused by poor compatibility, not only improves the adhesion and adhesion stability, but also improves the corrosion resistance, at the same time, also lays a foundation for subsequent high loading and stable anchoring of phytic acid;

[0042] (2) 0.1 g of the aluminum-loaded MCM-41 mesoporous silica prepared in step (1) was dispersed in 20 mL of anhydrous ethanol to form a dispersion liquid for use, and a phytic acid solution with a mass fraction of 50% was adjusted to a pH of 4.0 with ammonia water. The amount of the phytic acid solution added was 0.3 g. The phosphoric acid groups of the phytic acid molecules can not only form strong coordination reactions with metal ions, but also form strong hydrogen bond networks with the polar groups of epoxy resin and polyurethane resin, thereby improving the interfacial compatibility and binding force between the filler and the resin matrix and enhancing the cohesive strength of the coating, so as to better resist the stress of peeling off from the substrate. Then, the dispersion liquid was added, and the reaction was stirred at 20°C for 2 h. The collected precipitate was washed with anhydrous ethanol and deionized water alternately for 3 times, and then vacuum dried at 60°C for 12 h to obtain a phytic acid@aluminum-loaded MCM-41 mesoporous silica powder. The phytic acid is anchored inside and on the surface of the aluminum-loaded MCM-41 mesoporous silica through strong Al-O-P coordination bonds. When the coating is cured, the coating layer is damaged, corrosion begins, and the local microenvironment pH changes, the coordination bonds are broken, and the released phytic acid quickly migrates to the exposed metal surface. The multiple phosphoric acid groups of the phytic acid strongly complex with metal ions to form a dense, stable and insoluble phytic acid-metal protective film on the metal surface, which not only locks the coating on the metal surface and enhances the adhesion of the cured coating, but also effectively blocks the corrosion medium and actively inhibits the continuation of the corrosion reaction, thereby improving the corrosion resistance through the targeted self-repairing corrosion protection mode;

[0043] (3) 1.0 g of the phytic acid-aluminum-loaded MCM-41 mesoporous silica powder obtained in step (2) was added to 80 mL of anhydrous ethanol, followed by the addition of polyethyleneimine, stirring for 30 min, and then the addition of sodium polystyrene sulfonate, stirring for 20 min. The amount of polyethyleneimine added was 0.1 g, and the amount of sodium polystyrene sulfonate added was 0.1 g. The polyethyleneimine and the sodium polystyrene sulfonate can form a polyelectrolyte bilayer shell through electrostatic adsorption, which not only provides a strong defense line against the penetration of corrosive media, but also enables the filler to be more uniformly dispersed in the resin, and also prevents the premature leakage of phytic acid. Under corrosive or acidic conditions, the polyethyleneimine and the sodium polystyrene sulfonate undergo protonation, the polyelectrolyte bilayer shell opens, and then the phytic acid is released to act on the corrosion sites, making the corrosion prevention more durable and efficient. A 10 mL aqueous solution of glutaraldehyde with a mass fraction of 25% was prepared by rotary evaporation to remove water, and then diluted with anhydrous ethanol to prepare a 3% glutaraldehyde alcohol solution. Then, ammonia water was added dropwise to adjust the pH of the suspension to 8.0. Under stirring at a speed of 3000 rpm, 0.5 mL of the glutaraldehyde alcohol solution was added to the suspension, which was then heated to 40°C and stirred for 4 h. The precipitate was collected by centrifugation and washed with anhydrous ethanol three times, and then dried at 60°C under vacuum for 8 h to obtain a cross-linked membrane-modified phytic acid-aluminum-loaded MCM-41 mesoporous silica composite synergistic filler. Glutaraldehyde, as a bifunctional cross-linking agent, stitches the polyelectrolyte bilayer shell of loose polyethyleneimine and sodium polystyrene sulfonate into a strong, dense, three-dimensional cross-linked membrane, which has high mechanical strength and toughness, thereby improving the cohesive strength and modulus of the coating, effectively reducing the peeling of the coating from the metal substrate after curing, and the polar groups such as amine groups and sulfonic acid groups on the shell form strong hydrogen bonds and dipole-dipole interactions with the resin, improving the interfacial compatibility and adhesion between the two, which is also beneficial to enhancing the adhesion. The cross-linked membrane formed by glutaraldehyde further twists and blocks the penetration path of corrosive media such as water, oxygen, and chloride ions, eliminating the interfacial defects between the filler and the resin, making it more difficult for corrosive media to penetrate through the interfacial channel, and enhancing the overall shielding performance and corrosion resistance of the coating.

[0044] The present embodiment provides a preparation method of a high-efficiency anticorrosive coating, which specifically comprises the following steps:

[0045] S1, after the water is removed polyethylene glycol PEG-1000, toluene diisocyanate and 100 mL of acetone together into the reaction kettle, polyethylene glycol PEG-1000 and toluene diisocyanate is added respectively 100 g, 50 g, polyethylene glycol PEG-1000 segment of hydrophilic and flexible help paint better wetting metal surface, and penetrate into the micro pores of the substrate, enhance the mechanical anchoring effect, toluene diisocyanate in the coating curing process, its residual isocyanate group and metal surface form chemical bonding, enhance the adhesion stability of coating, nitrogen protection, heating to 70 DEG C, reaction 3 h, ensure that the-NCO conversion rate in the reaction process reaches more than 98%, 10.5 g of 2, 2-bis hydroxymethyl propionic acid is first dissolved in 50 mL of acetone, then added to the reaction kettle, continue to react 1.5 h, ensure that the-NCO conversion rate in the reaction process reaches more than 98%, then followed by the addition of 40 g of bisphenol A type epoxy resin and 100 mL of acetone, heating to 80 DEG C reaction 5 h, after the reaction is completed, cooling to 45 DEG C, the addition of 13 mL of triethylamine for neutralization, finally add 500 mL of deionized water to 2000 rpm speed high speed dispersion 10 min, reduced pressure distillation, polyurethane / epoxy resin composite emulsion system is obtained, in this process, polyethylene glycol PEG-1000 as soft segment, provides the flexibility and elasticity, toluene diisocyanate as hard segment, provides the extremely high cohesive strength and hardness, the rigid and flexible micro phase separation structure formed by the two, avoid the pure epoxy resin of brittle cracking and pure flexible glue of strength insufficient defect, thus realizes the lasting and strong adhesion, the polyurethane backbone framework constructed by the two and epoxy resin together form the dense, crosslinked, strong and tough coating structure, not only effectively prolong the penetration path of water, oxygen, chloride ion and other corrosion medium, but also can better resist scratch, impact, wear and low temperature damage, through the complete and stable barrier effect, from the source to eliminate the starting point of corrosion;

[0046] S2, hydroxyethyl cellulose, deionized water into a high-speed mixer, stirring to complete dissolution at 300 rpm speed, then at 500 rpm speed, adding BYK-190 dispersant, titanium dioxide, cross-linked membrane modified phytic acid@aluminum-loaded MCM-41 mesoporous silica composite synergistic filler in turn for pre-dispersion treatment, adjusting the stirring speed to 2000 rpm, stirring for 10 min, forming a uniform slurry, then reducing the speed to 800 rpm, adding the polyurethane / epoxy composite emulsion system described in step S1, stirring for 20 min, then adding BYK-021 defoamer, BYK-358N leveling agent and BYK-425 thickener, continuing to disperse for 20 min, finally transferring the material to a horizontal sand mill for circulation grinding, ensuring that the particle size is not more than 25 μm, after grinding, filtering with a 100 mesh screen, obtaining a high-efficiency anticorrosive coating, the polyurethane / epoxy composite emulsion system as the continuous phase and the binding framework of the coating, the cross-linked membrane modified phytic acid@aluminum-loaded MCM-41 mesoporous silica composite synergistic filler, functional pigments and auxiliaries are bonded into a whole, forming a multi-phase composite coating structure, not only realizing long-lasting and high-strength adhesion, but also significantly improving the corrosion resistance through the constructed multi-layer defense mechanism of intelligent response, active repair and physical barrier.

[0047] Example 3

[0048] The present embodiment proposes a high-efficiency anticorrosive coating, comprising the following components in parts by weight: cross-linked membrane modified phytic acid@aluminum-loaded MCM-41 mesoporous silica composite synergistic filler 15 parts, polyurethane / epoxy composite emulsion system 50 parts, titanium dioxide 17.5 parts, BYK-190 dispersant 0.4 parts, BYK-021 defoamer 0.3 parts, BYK-358N leveling agent 0.3 parts, BYK-425 thickener 0.3 parts, hydroxyethyl cellulose 0.4 parts, deionized water 17.5 parts.

[0049] The cross-linked membrane modified phytic acid@aluminum-loaded MCM-41 mesoporous silica composite synergistic filler comprises the following components in parts by weight: phytic acid@aluminum-loaded MCM-41 mesoporous silica powder 15 parts, polyethyleneimine 2 parts, poly (p-phenylene sulfonic acid) sodium 2 parts, glutaraldehyde 0.24 parts.

[0050] The preparation method of the cross-linked membrane modified phytic acid@aluminum-loaded MCM-41 mesoporous silica composite synergistic filler comprises the following steps:

[0051] (1) 1.5 g of MCM-41 mesoporous silica is added to 50 mL of n-hexane solvent treated by 3A molecular sieve, stirred for 15 min to form mixture I for standby, then 0.25 g of aluminum isopropoxide is added to 150 mL of n-hexane solvent treated by 3A molecular sieve, stirred for 15 min, the amount of aluminum isopropoxide added is 0.25 g, the aluminum center as Lewis acid site can form coordination bond or weak chemical bond with the oxide layer or hydroxyl group on the surface of the metal substrate, thereby enhancing the bridging effect of the filler and the substrate, and also producing stronger dipole-dipole interaction with the polar groups in the resin, improving the compatibility and binding force of the filler in the resin matrix, reducing the micropore defects at the interface, thereby enhancing the overall corrosion protection barrier effect, mixture II is formed for standby, mixture I is added to mixture II under the stirring speed of 550 rpm, after the addition is completed, continue to stir for 15 min, seal and stand at room temperature for 24 h, vacuum filtration, the solid is washed twice with 100 mL of n-hexane solvent which has been dried, first dried at room temperature for 12 h, then put into a muffle furnace and calcined at 525°C for 3 h, to obtain aluminum-loaded MCM-41 mesoporous silica, the aluminum-loaded modification treatment of MCM-41 mesoporous silica introduces aluminum center reaction sites, enhances the interface bonding force of the filler and the resin and the substrate, reduces the phase separation and micro defects caused by poor compatibility, not only improves the adhesion and adhesion stability, but also improves the corrosion resistance, at the same time, also lays a foundation for subsequent high loading and stable anchoring of phytic acid;

[0052] (2) 0.2 g of the aluminum-loaded MCM-41 mesoporous silica described in step (1) is weighed and dispersed in 20 mL of anhydrous ethanol to form a dispersion liquid for use. A phytic acid solution with a mass fraction of 50% is adjusted to a pH of 4.5 with ammonia water, and the amount of the phytic acid solution added is 0.35 g. The phosphoric acid groups of the phytic acid molecules can not only have a strong coordination reaction with metal ions, but also form a strong hydrogen bond network with the polar groups of epoxy resin and polyurethane resin, thereby improving the interfacial compatibility and binding force between the filler and the resin matrix and enhancing the cohesive strength of the coating, so as to better resist the stress of peeling off from the substrate. Then, the dispersion liquid is added, and stirring is performed at 20°C for 2.5 h. The collected precipitate is washed with anhydrous ethanol and deionized water alternately for 3 times, and then vacuum dried at 60°C for 12 h to obtain a phytic acid@aluminum-loaded MCM-41 mesoporous silica powder. The phytic acid is anchored inside and on the surface of the aluminum-loaded MCM-41 mesoporous silica through a strong Al-O-P coordination bond. When the coating is cured, the coating layer is damaged, corrosion begins, and the local microenvironment pH changes, the coordination bond is broken, and the released phytic acid quickly migrates to the exposed metal surface. The multiple phosphoric acid groups of the phytic acid strongly complex with metal ions to form a dense, stable, and insoluble phytic acid-metal protective film on the metal surface, which not only locks the coating on the metal surface and enhances the adhesion of the cured coating, but also effectively blocks the corrosion medium and actively inhibits the continuation of the corrosion reaction, thereby improving the corrosion resistance through the targeted self-repairing corrosion protection mode;

[0053] (3) 1.5 g of the phytic acid-aluminum-loaded MCM-41 mesoporous silica powder obtained in step (2) was added to 90 mL of anhydrous ethanol, followed by the addition of polyethyleneimine and stirring for 35 min, and then the addition of sodium polystyrene sulfonate and stirring for 25 min. The amount of polyethyleneimine added was 0.2 g, and the amount of sodium polystyrene sulfonate added was 0.2 g. The polyethyleneimine and the sodium polystyrene sulfonate can form a polyelectrolyte bilayer shell through electrostatic adsorption, which not only provides a strong defense line against the penetration of corrosive media, but also enables the filler to be more uniformly dispersed in the resin, and also prevents the premature leakage of phytic acid. Under corrosive or acidic conditions, the polyethyleneimine and the sodium polystyrene sulfonate undergo protonation, the polyelectrolyte bilayer shell opens, and then the phytic acid is released to act on the corrosion sites, making the corrosion prevention more durable and efficient. A 10 mL aqueous solution of glutaraldehyde with a mass fraction of 25% was removed of water by rotary evaporation, and then diluted with anhydrous ethanol to obtain a 4% glutaraldehyde alcohol solution. Then, ammonia water was added dropwise to adjust the pH of the suspension to 8.5. Under stirring at a speed of 3500 rpm, 0.75 mL of the glutaraldehyde alcohol solution was added to the suspension, which was then heated to 45°C and stirred for 5 h. The precipitate was collected by centrifugation and washed with anhydrous ethanol four times, and then dried at 60°C under vacuum for 8 h to obtain a cross-linked membrane-modified phytic acid-aluminum-loaded MCM-41 mesoporous silica composite synergistic filler. Glutaraldehyde, as a bifunctional cross-linking agent, stitches the polyelectrolyte bilayer shell of loose polyethyleneimine and sodium polystyrene sulfonate into a strong, dense, three-dimensional cross-linked membrane, which has high mechanical strength and toughness, thereby improving the cohesive strength and modulus of the coating, effectively reducing the peeling of the coating from the metal substrate after curing, and the polar groups such as amine groups and sulfonic acid groups on the shell form strong hydrogen bonds and dipole-dipole interactions with the resin, improving the interfacial compatibility and bonding between the two, which also helps to enhance the adhesion. The cross-linked membrane formed by glutaraldehyde further twists and blocks the penetration path of corrosive media such as water, oxygen, and chloride ions, eliminating the interfacial defects between the filler and the resin, making it more difficult for corrosive media to penetrate through the interfacial channel, and enhancing the overall shielding performance and corrosion resistance of the coating.

[0054] The present embodiment provides a preparation method of a high-efficiency anticorrosive coating, which specifically comprises the following steps:

[0055] S1, after the water polyethylene glycol PEG-1000, toluene diisocyanate and 100-200 mL of acetone together into the reaction kettle, polyethylene glycol PEG-1000 and toluene diisocyanate, the amount of 125 g, 55 g, polyethylene glycol PEG-1000 segment of the hydrophilic and flexible to help paint better wetting metal surface, and penetrate into the micro pores of the substrate, enhance the mechanical anchoring effect, toluene diisocyanate in the coating curing process, its residual isocyanate group and metal surface form chemical bonding, enhance the adhesion stability of the coating, nitrogen protection, heating to 72.5 DEG C, reaction 3.5 h, ensure that the-NCO conversion rate in the reaction process more than 98%, first dissolved in 50 mL of acetone, 11.5 g of 2, 2-bis hydroxymethyl propionic acid, then add to the reaction kettle, continue to react 2 h, ensure that the-NCO conversion rate in the reaction process more than 98%, then followed by the addition of 45 g of bisphenol A type epoxy resin and 100-120 mL of acetone, heating to 82.5 DEG C reaction 5.5 h, after the reaction is completed, cooling to 45 DEG C, add 15 mL of triethylamine for neutralization, finally add 600 mL of deionized water to 2500 rpm speed high speed dispersion 15 min, reduced pressure distillation, polyurethane / epoxy resin composite emulsion system, in this process, polyethylene glycol PEG-1000 as soft segment, provides flexibility and elasticity, toluene diisocyanate as hard segment, provides high cohesive strength and hardness, the two formed rigid and flexible micro phase separation structure, avoid the pure epoxy resin of brittle cracking and pure flexible glue of strength insufficient defect, so as to realize the lasting and strong adhesion, the polyurethane backbone and epoxy resin constructed together form a dense, crosslinked, strong and tough coating structure, not only effectively prolong the penetration path of water, oxygen, chloride ion and other corrosion medium, but also can better resist scratch, impact, wear and low temperature damage, through the complete and stable barrier effect, from the source to eliminate the starting point of corrosion;

[0056] S2, hydroxyethyl cellulose, deionized water into a high-speed blender, stirring to complete dissolution at 400 rpm speed, then at 650 rpm speed, adding BYK-190 dispersant, titanium dioxide, cross-linked membrane modified phytic acid@aluminum-loaded MCM-41 mesoporous silica composite synergistic filler in turn for pre-dispersion treatment, adjusting the stirring speed to 2250 rpm, stirring for 15 min, then reducing the speed to 900 rpm, adding the polyurethane / epoxy composite emulsion system described in step S1, stirring for 25 min, then adding BYK-021 defoamer, BYK-358N leveling agent and BYK-425 thickener, continuing to disperse for 25 min, finally transferring the material to a horizontal sand mill for circulation grinding, ensuring that the particle size is not more than 25 μm, after grinding, filtering with a 150 mesh screen to obtain a high-efficiency anticorrosive coating, the polyurethane / epoxy composite emulsion system as the continuous phase and the binding framework of the coating, the cross-linked membrane modified phytic acid@aluminum-loaded MCM-41 mesoporous silica composite synergistic filler, functional pigments and auxiliaries are bonded into a whole, forming a multi-phase composite coating structure, not only realizing long-lasting and high-strength adhesion, but also significantly improving the corrosion resistance through the constructed multi-layer defense mechanism of intelligent response, active repair and physical barrier.

[0057] Example 4

[0058] The present embodiment proposes a high-efficiency anticorrosive coating, which comprises the following components in parts by weight: cross-linked membrane modified phytic acid@aluminum-loaded MCM-41 mesoporous silica composite synergistic filler 20 parts, polyurethane / epoxy composite emulsion system 40 parts, titanium dioxide 20 parts, BYK-190 dispersant 0.5 parts, BYK-021 defoamer 0.4 parts, BYK-358N leveling agent 0.4 parts, BYK-425 thickener 0.4 parts, hydroxyethyl cellulose 0.5 parts, deionized water 20 parts.

[0059] The cross-linked membrane modified phytic acid@aluminum-loaded MCM-41 mesoporous silica composite synergistic filler comprises the following components in parts by weight: phytic acid@aluminum-loaded MCM-41 mesoporous silica powder 20 parts, polyethyleneimine 1 part, poly (p-phenylene sulfonic acid) sodium 1 part, glutaraldehyde 0.40 part.

[0060] The preparation method of the cross-linked membrane modified phytic acid@aluminum-loaded MCM-41 mesoporous silica composite synergistic filler comprises the following steps:

[0061] (1) 2.0 g of MCM-41 mesoporous silica is added to 50 mL of n-hexane solvent treated by 3A molecular sieve, stirred for 10 min to form mixture I for standby, then 0.2 g of aluminum isopropoxide is added to 150 mL of n-hexane solvent treated by 3A molecular sieve, stirred for 10 min, the amount of aluminum isopropoxide added is 0.2 g, the aluminum center as a Lewis acid site can form a coordination bond or a weak chemical bond with the oxide layer or hydroxyl group on the surface of the metal substrate, thereby enhancing the bridging effect of the filler and the substrate, and also producing stronger dipole-dipole interaction with the polar groups in the resin, improving the compatibility and binding force of the filler in the resin matrix, reducing the micropore defects at the interface, thereby enhancing the overall corrosion protection barrier effect, mixture II is formed for standby, mixture I is added to mixture II under a stirring speed of 600 rpm, after the addition is completed, continue to stir for 10 min, seal and stand at room temperature for 24 h, vacuum filtration, the solid is washed 3 times with 100 mL of n-hexane solvent which has been dried, first dried at room temperature for 12 h, then placed in a muffle furnace and calcined at 550°C for 2 h to obtain aluminum-loaded MCM-41 mesoporous silica, the aluminum-loaded modification treatment of MCM-41 mesoporous silica introduces aluminum center reaction sites, enhances the interface bonding force of the filler and the resin and the substrate, reduces the phase separation and micro defects caused by poor compatibility, not only improves the adhesion and adhesion stability, but also improves the corrosion resistance, at the same time, also lays a foundation for subsequent high loading and stable anchoring of phytic acid;

[0062] (2) 0.3 g of the aluminum-loaded MCM-41 mesoporous silica described in step (1) is weighed and dispersed in 20 mL of anhydrous ethanol to form a dispersion liquid for use. A phytic acid solution with a mass fraction of 50% is adjusted to a pH of 5.0 with ammonia water, and the amount of the phytic acid solution added is 0.3 g. The phosphoric acid groups of the phytic acid molecules can not only have a strong coordination reaction with metal ions, but also form a strong hydrogen bond network with the polar groups of epoxy resin and polyurethane resin, thereby improving the interfacial compatibility and binding force between the filler and the resin matrix and enhancing the cohesive strength of the coating, so as to better resist the stress of peeling off from the substrate. Then, the dispersion liquid is added, and stirring is performed at 20°C for 2 h. The collected precipitate is washed with anhydrous ethanol and deionized water alternately for 3 times, and then vacuum dried at 60°C for 12 h to obtain a phytic acid@aluminum-loaded MCM-41 mesoporous silica powder. The phytic acid is anchored inside and on the surface of the aluminum-loaded MCM-41 mesoporous silica through a strong Al-O-P coordination bond. When the coating is cured, the coating layer is damaged, corrosion begins, and the local microenvironment pH changes, the coordination bond is broken, and the released phytic acid quickly migrates to the exposed metal surface. The multiple phosphoric acid groups of the phytic acid strongly complex with metal ions to form a dense, stable and insoluble phytic acid-metal protective film on the metal surface, which not only locks the coating on the metal surface and enhances the adhesion of the cured coating, but also effectively blocks the corrosion medium and actively inhibits the continuation of the corrosion reaction, thereby improving the corrosion resistance through the targeted self-repairing corrosion protection mode;

[0063] (3) 2.0 g of the phytic acid-aluminum loaded MCM-41 mesoporous silica powder of step (2) is weighed into 100 mL of anhydrous ethanol, then polyethyleneimine is added, stirred for 30 min, and then sodium polystyrene sulfonate is added, stirred for 20 min. The amount of polyethyleneimine added is 0.1 g, and the amount of sodium polystyrene sulfonate added is 0.1 g. The polyethyleneimine and the sodium polystyrene sulfonate can form a polyelectrolyte bilayer shell through electrostatic adsorption, which not only provides a strong defense line against the penetration of corrosive media, but also enables the filler to be more uniformly dispersed in the resin, and also prevents premature leakage of phytic acid. Under corrosive or acidic conditions, the polyethyleneimine and the sodium polystyrene sulfonate undergo protonation, the polyelectrolyte bilayer shell opens, and then the phytic acid is released to act on the corrosion site, making the corrosion prevention more durable and efficient. A 10 mL aqueous solution of glutaraldehyde with a mass fraction of 25% is removed of water by rotary evaporation, and then diluted with anhydrous ethanol to form a 5% glutaraldehyde alcohol solution. Then, ammonia water is added dropwise to adjust the pH of the suspension to 9.0. Under stirring at a speed of 4000 rpm, 1.0 mL of the glutaraldehyde alcohol solution is added to the suspension, which is heated to 50°C and stirred for 4 h. The precipitate is collected by centrifugation and washed with anhydrous ethanol 5 times, and then dried at 60°C under vacuum for 8 h to obtain a cross-linked membrane modified phytic acid-aluminum loaded MCM-41 mesoporous silica composite synergistic filler. Glutaraldehyde, as a bifunctional cross-linking agent, stitches the polyelectrolyte bilayer shell of loose polyethyleneimine and sodium polystyrene sulfonate into a strong, dense, three-dimensional cross-linked membrane with high mechanical strength and toughness, thereby improving the cohesive strength and modulus of the coating, effectively reducing the peeling of the coating from the metal substrate after curing. The polar groups such as amine groups and sulfonic acid groups on the shell form strong hydrogen bonds and dipole-dipole interactions with the resin, improving the interfacial compatibility and adhesion between the two, which also helps to enhance the adhesion. The cross-linked membrane formed by glutaraldehyde further twists and blocks the penetration path of corrosive media such as water, oxygen, and chloride ions, eliminating the interfacial defects between the filler and the resin, making it more difficult for corrosive media to penetrate through the interfacial channel, and enhancing the overall shielding performance and corrosion resistance of the coating.

[0064] The embodiment provides a preparation method of a high-efficiency anticorrosive coating, which specifically comprises the following steps.

[0065] S1, after the water is removed polyethylene glycol PEG-1000, toluene diisocyanate and 100-200 mL of acetone into the reaction kettle, polyethylene glycol PEG-1000 and toluene diisocyanate is added respectively 150 g, 50 g, polyethylene glycol PEG-1000 segment of hydrophilic and flexible help paint better wetting metal surface, and penetrate into the micro pores of the substrate, enhance the mechanical anchoring effect, toluene diisocyanate in the coating curing process, its residual isocyanate group and metal surface form chemical bonding, enhance the adhesion stability of coating, nitrogen protection, heating to 75 DEG C, reaction 3 h, ensure that the-NCO conversion rate in the reaction process reaches more than 98%, 12.5 g of 2, 2-bis hydroxymethyl propionic acid is first dissolved in 50 mL of acetone, then added to the reaction kettle, continue to react 1.5 h, ensure that the-NCO conversion rate in the reaction process reaches more than 98%, then followed by the addition of 50 g of bisphenol A type epoxy resin and 120 mL of acetone, heating to 85 DEG C reaction 5 h, after the reaction is completed, cooling to 45 DEG C, the addition of 17 mL of triethylamine for neutralization, finally add 700 mL of deionized water to 3000 rpm speed high speed dispersion 10 min, reduced pressure distillation, polyurethane / epoxy resin composite emulsion system is obtained, in this process, polyethylene glycol PEG-1000 as soft segment, provides the flexibility and elasticity, toluene diisocyanate as hard segment, provides the extremely high cohesive strength and hardness, the rigid and flexible micro phase separation structure formed by the two, avoid the pure epoxy resin of brittle cracking and pure flexible glue of strength insufficient defect, thus realizes the lasting and strong adhesion, the polyurethane backbone framework constructed by the two and epoxy resin together form the dense, crosslinked, strong and tough coating structure, not only effectively prolong the penetration path of water, oxygen, chloride ion and other corrosion medium, but also can better resist scratch, impact, wear and low temperature damage, through the complete and stable barrier effect, from the source to eliminate the starting point of corrosion;

[0066] S2, hydroxyethyl cellulose, deionized water were added into a high-speed mixer, stirred at 500 rpm until completely dissolved, then pre-dispersed with BYK-190 dispersant, titanium dioxide, cross-linked membrane modified phytic acid@aluminum-loaded MCM-41 mesoporous silica composite synergistic filler at 800 rpm, adjust the stirring speed to 2500 rpm, stirring time 10 min, form a uniform slurry, then reduce the speed to 1000 rpm, add the polyurethane / epoxy composite emulsion system described in step S1, stir for 20 min, then add BYK-021 defoamer, BYK-358N leveling agent and BYK-425 thickener, continue to disperse for 20 min, finally transfer the material to a horizontal sand mill for circulation grinding, ensure that the particle size is not more than 25 μm, after grinding, filter with a 200 mesh screen to obtain a high-efficiency anticorrosive coating, the polyurethane / epoxy composite emulsion system as the continuous phase and the binding framework of the coating, the cross-linked membrane modified phytic acid@aluminum-loaded MCM-41 mesoporous silica composite synergistic filler, functional pigments and additives are bound into a whole, forming a multi-phase composite coating structure, not only realizing long-lasting and high-strength adhesion, but also significantly improving the corrosion resistance through the constructed multi-layer defense mechanism of intelligent response, active repair and physical barrier.

[0067] Comparative Example 1

[0068] The present comparative example provides a high-efficiency anticorrosive coating, which is different from Example 1 in that the cross-linked membrane modified phytic acid@aluminum-loaded MCM-41 mesoporous silica composite synergistic filler does not contain aluminum isopropyl alcohol; the preparation method of the cross-linked membrane modified phytic acid@aluminum-loaded MCM-41 mesoporous silica composite synergistic filler does not include step (1), and in step (2), MCM-41 mesoporous silica is directly dispersed in 20 mL of anhydrous ethanol to form a dispersion liquid for use; the preparation method of the high-efficiency anticorrosive coating is the same as that of Example 1.

[0069] Comparative Example 2

[0070] The present comparative example provides a high-efficiency anticorrosive coating, which is different from Example 1 in that the cross-linked membrane modified phytic acid@aluminum-loaded MCM-41 mesoporous silica composite synergistic filler does not contain polyethyleneimine and sodium poly (p-styrenesulfonate); in step (3) of the preparation method of the cross-linked membrane modified phytic acid@aluminum-loaded MCM-41 mesoporous silica composite synergistic filler, polyethyleneimine and sodium poly (p-styrenesulfonate) are not added; the preparation method of the high-efficiency anticorrosive coating is the same as that of Example 1.

[0071] Comparative Example 3

[0072] The comparative example provides a high-efficiency anticorrosive coating, which is different from example 1 in that the cross-linked membrane modified phytic acid loaded aluminum MCM-41 mesoporous silica composite synergistic filler does not contain glutaraldehyde; no glutaraldehyde alcohol solution is added in step (3) of the preparation method of the cross-linked membrane modified phytic acid loaded aluminum MCM-41 mesoporous silica composite synergistic filler; and the preparation method of the high-efficiency anticorrosive coating is the same as that of example 1.

[0073] Experimental example 1

[0074] Adhesion experiment

[0075] Test sample: the high-efficiency anticorrosive coating prepared in examples 1-4 and comparative examples 1-3.

[0076] Test method: the test sample and the curing agent are mixed uniformly at a ratio of 5:1, sprayed on a 440C martensitic stainless steel substrate, and after curing (the coating thickness is 80±10 μm), the adhesion is measured by a pull-off adhesion tester according to the standard of ASTM D4541, the pressure system is calibrated by NIST, the accuracy is ±1% (full scale), and the value is accurate to 0.01.

[0077] Figure 2 The adhesion results of examples 1-4 and comparative examples 1-3 are shown in the figure. As shown in the figure, the adhesion of examples 1-4 is 17.0-18.6 MPa, indicating good adhesion; the adhesion of comparative examples 1-3 is 9.8-14.9 MPa, indicating general or poor adhesion; the cross-linked membrane modified phytic acid loaded aluminum MCM-41 mesoporous silica composite synergistic filler of comparative example 1 does not contain aluminum isopropyl alcohol, and phytic acid cannot form stable loading by coordination with aluminum sites, thereby being not conducive to the bridging role of phytic acid in connecting the filler and the substrate, resulting in poor adhesion; the cross-linked membrane modified phytic acid loaded aluminum MCM-41 mesoporous silica composite synergistic filler of comparative example 2 does not contain polyethyleneimine and sodium poly (p-styrenesulfonate), and cannot form a double-layer shell on the surface of the phytic acid loaded aluminum MCM-41 mesoporous silica powder by self-assembly, which is not conducive to improving the compatibility and dispersion of the filler in the resin system, thereby being not conducive to improving the uniformity and cohesive strength of the coating as a whole, resulting in general adhesion; the cross-linked membrane modified phytic acid loaded aluminum MCM-41 mesoporous silica composite synergistic filler of comparative example 3 does not contain glutaraldehyde, and cannot stitch the double-layer shell into a strong and dense cross-linked membrane by cross-linking, which is not conducive to improving the cohesive strength and modulus of the coating, resulting in general adhesion.

[0078] Experimental example 2

[0079] Corrosion resistance experiment

[0080] Test sample: the high-efficiency anticorrosive coating prepared in examples 1-4 and comparative examples 1-3.

[0081] Test method: according to GB / T1771-2007, the test sample and curing agent were mixed uniformly at a ratio of 5:1, sprayed on the 440C martensitic stainless steel substrate and drawn X to the substrate, and after curing, the coating thickness was 80±10 μm, placed in a salt spray chamber, the temperature was 35±2℃, the salt spray solution deposition amount was 1.0-2.0 mL / h, and a 5% NaCl solution (pH value was 6.5-7.2) was used, and the salt spray test was carried out for 500h, after the test, the corrosion was peeled off along the X scratch, and the length was measured at the maximum corrosion of the substrate, which was recorded as the maximum corrosion length (mm).

[0082] Figure 3 The corrosion maximum length results of examples 1-4 and comparative examples 1-3 are shown in the figure; as shown in the figure, the corrosion maximum length of examples 1-4 is 0.2-0.7mm, indicating that the corrosion resistance is strong; the corrosion maximum length of comparative examples 1-3 is 1.8-5.0mm, indicating that the corrosion resistance is general or poor; the cross-linked membrane modified phytic acid@aluminum-loaded MCM-41 mesoporous silica composite synergistic filler in comparative example 1 does not contain aluminum isopropyl alcohol, which cannot be stabilized by chemical coordination to load phytic acid, resulting in the loss of phytic acid, and thus cannot play a precise and effective corrosion protection role through intelligent response and active repair, resulting in poor corrosion resistance; the cross-linked membrane modified phytic acid@aluminum-loaded MCM-41 mesoporous silica composite synergistic filler in comparative example 2 does not contain polyethyleneimine and sodium poly (p-styrenesulfonate), which cannot build an intelligent response shell for phytic acid, which is not conducive to the intelligent corrosion protection and self-repairing effect of phytic acid, resulting in poor corrosion resistance; the cross-linked membrane modified phytic acid@aluminum-loaded MCM-41 mesoporous silica composite synergistic filler in comparative example 3 does not contain glutaraldehyde, which cannot enhance the tightness and insulation of the shell through cross-linking, which is not conducive to further tortuous and blocking the penetration path of the corrosion medium, resulting in general corrosion resistance.

[0083] The above experimental results show that the adhesion and corrosion resistance of examples 1-4 of the present application are significantly better than those of comparative examples 1-3, wherein the adhesion and corrosion resistance of example 1 using the cross-linked membrane modified phytic acid@aluminum-loaded MCM-41 mesoporous silica composite synergistic filler and polyurethane / epoxy resin composite emulsion system are better and stronger, respectively, the cross-linked membrane modified phytic acid@aluminum-loaded MCM-41 mesoporous silica composite synergistic filler is uniformly dispersed and deeply embedded in the polyurethane / epoxy resin composite emulsion system, which not only establishes numerous chemical anchor points between the substrate and the resin system, but also enhances the interfacial bonding between the two, thereby greatly improving the adhesion of the coating, at the same time, the active and passive three-dimensional protection system formed by the two has the functions of intelligent response, active repair and physical barrier, which significantly improves the corrosion resistance of the coating.

[0084] While embodiments of the application have been shown and described, it is to be understood that the embodiments described are merely exemplary and that changes can be made in the embodiments without departing from the spirit and scope of the application.

[0085] The above description of the application and its embodiments is not restrictive, and the embodiments shown in the drawings are only one of the embodiments of the application, and the actual application is not limited thereto. In general, if a person skilled in the art is inspired by it, without departing from the purpose of the application, without creative design, similar ways and embodiments of the technical solution should belong to the protection scope of the application.

Claims

1. A high performance anticorrosive coating, characterized by: The high-efficiency anticorrosive coating comprises the following components in parts by weight: 10-20 parts of cross-linked membrane modified phytic acid@aluminum-loaded MCM-41 mesoporous silica composite synergistic filler, 40-60 parts of polyurethane / epoxy resin composite emulsion system, 15-20 parts of titanium white, 0.3-0.5 parts of BYK-190 dispersant, 0.2-0.4 parts of BYK-021 defoaming agent, 0.2-0.4 parts of BYK-358N leveling agent, 0.2-0.4 parts of BYK-425 thickening agent, 0.3-0.5 parts of hydroxyethyl cellulose, and 15-20 parts of deionized water; the cross-linked membrane modified phytic acid@aluminum-loaded MCM-41 mesoporous silica composite synergistic filler comprises the following components in parts by weight: 10-20 parts of phytic acid@aluminum-loaded MCM-41 mesoporous silica powder, 1-3 parts of polyethyleneimine, 1-3 parts of sodium poly(p-styrenesulfonate), and 0.12-0.40 parts of glutaraldehyde.

2. A process for the preparation of the high performance anticorrosive coating as claimed in claim 1, characterized in that: Specifically comprising the following steps: S1, polyethylene glycol PEG-1000, toluene diisocyanate and 100-200 mL of acetone after water removal are added into a reaction kettle, nitrogen protection is performed, temperature is raised to 70-75℃, reaction is carried out for 3-4 h, 10.5-12.5 g of 2,2-bishydroxymethylpropionic acid is first dissolved in 50 mL of acetone, then added into the reaction kettle, reaction is continuously carried out for 1.5-2.5 h, then 40-50 g of bisphenol A type epoxy resin and 100-120 mL of acetone are added, temperature is raised to 80-85℃, reaction is carried out for 5-6 h, after reaction is completed, temperature is lowered to 45℃, 13-17 mL of triethylamine is added for neutralization, finally 500-700 mL of deionized water is added, high-speed dispersion is carried out at a speed of 2000-3000 rpm for 10-20 min, vacuum distillation is carried out, and a polyurethane / epoxy resin composite emulsion system is obtained; S2, hydroxyethyl cellulose and deionized water are added into a high-speed stirrer, stirring is carried out at a speed of 300-500 rpm until complete dissolution, then BYK-190 dispersant, titanium white, cross-linked membrane modified phytic acid@aluminum-loaded MCM-41 mesoporous silica composite synergistic filler are added in sequence under a stirring speed of 500-800 rpm for pre-dispersion treatment, stirring speed is adjusted to 2000-2500 rpm, stirring time is 10-20 min, a uniform slurry is formed, then stirring speed is lowered to 800-1000 rpm, the polyurethane / epoxy resin composite emulsion system prepared in step S1 is added, stirring is carried out for 20-30 min, then BYK-021 defoaming agent, BYK-358N leveling agent and BYK-425 thickening agent are added, dispersion treatment is continuously carried out for 20-30 min, finally the material is transferred into a horizontal sand mill for circulation grinding, to ensure that the fineness of particles is not more than 25 μm, after grinding is completed, the material is filtered through a 100-200 mesh filter screen, and a high-efficiency anticorrosive coating is obtained.

3. The method of preparing a high performance anticorrosive coating according to claim 2, characterized in that: In step S1, the adding amount of polyethylene glycol PEG-1000 and toluene diisocyanate is 100-150 g and 50-60 g respectively.

4. The method of preparing a high performance anticorrosive coating according to claim 3, characterized in that: The preparation method of the cross-linked membrane modified phytic acid loaded aluminum MCM-41 mesoporous silica composite synergistic filler specifically comprises the following steps: (1) 1.0-2.0 g of MCM-41 mesoporous silica is added to 50 mL of n-hexane solvent treated by 3A molecular sieve drying, stirred for 10-20 min, to form a mixture I for standby, then aluminum isopropoxide is added to 150 mL of n-hexane solvent treated by 3A molecular sieve drying, stirred for 10-20 min, to form a mixture II for standby, the mixture I is added to the mixture II under the stirring speed of 500-600 rpm, after the addition is completed, the stirring is continued for 10-20 min, sealed and placed at room temperature for 24 h, vacuum filtered, the solid is washed with 100 mL of n-hexane solvent which has been dried for 2-3 times, first dried at room temperature for 12 h, then placed in a muffle furnace and calcined at 500-550 DEG C for 2-4 h, to obtain aluminum loaded MCM-41 mesoporous silica; (2) 0.1-0.3 g of the aluminum loaded MCM-41 mesoporous silica in step (1) is dispersed in 20 mL of anhydrous ethanol to form a dispersion liquid for standby, a phytic acid solution with a mass fraction of 50% is adjusted to pH 4.0-5.0 with ammonia water, then added to the dispersion liquid, stirred at 20 DEG C for 2-3 h, washed with anhydrous ethanol and deionized water alternately for 3 times, the collected precipitate is vacuum dried at 60 DEG C for 12 h, to obtain phytic acid loaded aluminum MCM-41 mesoporous silica powder; (3) 1.0-2.0 g of the phytic acid loaded aluminum MCM-41 mesoporous silica powder in step (2) is added to 80-100 mL of anhydrous ethanol, then polyethyleneimine is added, stirred for 30-40 min, then sodium polystyrene sulfonate is added, stirred for 20-30 min, to form a suspension liquid for standby, 10 mL of a 25% glutaraldehyde aqueous solution is removed of water by rotary evaporation, then diluted with anhydrous ethanol to a 3-5% glutaraldehyde alcohol solution for standby, then ammonia water is added dropwise to adjust the pH of the suspension liquid to 8.0-9.0, 0.5-1.0 mL of the glutaraldehyde alcohol solution is added to the suspension liquid under the stirring speed of 3000-4000 rpm, heated to 40-50 DEG C, stirred for 4-6 h, centrifuged, the precipitate is collected and washed with anhydrous ethanol for 3-5 times, vacuum dried at 60 DEG C for 8 h, to obtain a cross-linked membrane modified phytic acid loaded aluminum MCM-41 mesoporous silica composite synergistic filler.

5. The method of preparing a high performance anticorrosive coating according to claim 4, characterized in that: In step (1), the addition amount of aluminum isopropoxide is 0.2-0.3 g.

6. The method of preparing a high performance anticorrosive coating according to claim 5, characterized in that: In step (2), the addition amount of the phytic acid solution is 0.3-0.4 g.

7. The method of preparing a high performance anticorrosive coating according to claim 6, characterized in that: In step (3), the addition amount of polyethyleneimine is 0.1-0.3 g, and the addition amount of sodium polystyrene sulfonate is 0.1-0.3 g.

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