Metal anticorrosion agent and metal anticorrosion treatment method thereof

Abstract

The invention discloses a metal preservative and a metal anticorrosion treatment method thereof, and specifically relates to the technical field of metal preservatives, comprising 50 parts of modified epoxy resin, 8-12 parts of curing agent, 3-5 parts of auxiliary agent, 4-8 parts of self-repairing microcapsules, 10-12 parts of filler, and 23-26 parts of ionized water. The invention adopts a combination of organic polymer materials and inorganic salts, and cooperates with self-repairing microcapsules to improve the smoke resistance and self-repairing ability of the coating. The prepared self-repairing microcapsule core wall is well combined with the modified epoxy resin. When cracks appear in the coating, due to the fragility of the capsule wall, the microcapsule quickly ruptures, releases the core material, and bonds the cracks together. The self-repairing coating obtained after the self-repairing microcapsules are added can self-repair without external influence. When cracks appear in the coating, the wall material of the self-repairing microcapsule ruptures and the core material flows out.

Description

Technical Field

[0001] The present invention relates to the technical field of metal corrosion inhibitors, and more specifically, to a metal corrosion inhibitor and a metal corrosion treatment method thereof. Background Art

[0002] Metal corrosion is a phenomenon in which metals are destroyed by chemical or electrochemical effects of the environment. Metal corrosion affects all areas of marginal industrial production, causing huge economic losses, leading to an increase in the use of metal materials, and is not conducive to energy conservation, emission reduction and environmental protection.

[0003] Metal corrosion mainly includes two forms: electrochemical corrosion and seawater corrosion. Electrochemical corrosion is the damage caused by electrochemical reaction between the metal surface and the ion-conductive medium. Its main feature is that its reaction process can be divided into two relatively independent and simultaneous processes-cathode reaction and anode reaction. Its main feature is that there is a charged interface layer between the metal and the electrolyte. Seawater corrosion refers to the corrosion of equipment and facilities used in the marine environment. Seawater has the highest salt content and complex composition, and is a corrosive electrolyte. The high concentration of chloride ions and other halogen ions in seawater can prevent and destroy the passivation of metals, making the anode process easier to carry out. Under the pH value of seawater, seawater corrosion is an oxygen depolarization process, and the cathode process controls the speed of the corrosion reaction.

[0004] For a long time, people have been using a variety of technologies to protect metals. One of the most effective and economical methods is to apply an anti-corrosion coating on the metal surface to isolate the corrosive medium from the metal substrate. However, during the use of the coating, microcracks will occur due to changes in factors such as the environment or mechanical properties, and due to exposure to the atmosphere, the microcracks will gradually spread and expand, thereby accelerating the peeling and stratification of the coating at the interface between the metal and the coating, reducing the service life and anti-corrosion ability of the coating, and also affecting the use of the metal. Therefore, a metal preservative is needed to prevent the corrosion of metal materials and solve the problems of metal anti-corrosion coatings in the prior art that are prone to cracking, peeling, and poor anti-corrosion effects. Summary of the invention

[0005] In order to overcome the above-mentioned defects of the prior art, an embodiment of the present invention provides a metal corrosion inhibitor and a metal corrosion treatment method thereof, by providing a metal corrosion inhibitor to isolate the metal material from the medium in the environment, and at the same time providing a coating with self-healing ability to solve the problems raised in the above-mentioned background technology.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical scheme: a metal preservative, comprising 50 parts of modified epoxy resin, 8 to 12 parts of curing agent, 3 to 5 parts of auxiliary agent, 4 to 8 parts of self-repairing microcapsules, 10 to 12 parts of filler, and 23 to 26 parts of ionized water, wherein the filler is a mixture of barium sulfate and zinc sulfate in a ratio of 1:0.5 to 0.5:1, the curing agent is epoxy amine, the self-repairing microcapsules include a core material and a wall material, and the wall material: core material in the self-repairing microcapsules = 1.5:1, the wall material is epoxy amine, and the core material is a mixture of tung oil, benzotriazole and dimerized linoleic acid.

[0007] Preferably, the auxiliary agent is composed of a wetting agent, a defoaming agent, a dispersant and a diluent in a weight ratio of 1:0 to 1.2:0 to 0.8:0 to 0.5, the wetting agent is polyether-modified silicone oil; the defoaming agent is a polyether-type defoaming agent; the dispersant is an aqueous dispersant polyacrylate aqueous solution or polyethylene glycol; and the diluent is propylene oxide butyl ether.

[0008] Preferably, the preparation of the modified epoxy resin comprises the following steps:

[0009] Step S01, preparing modified prepolymer A: adding an appropriate amount of acetone to a four-necked bottle and heating it, and introducing condensed water and nitrogen, mixing toluene diisocyanate and polyethylene glycol as chain extenders in a certain proportion, and heating in a water bath at 40° C. to prepare modified prepolymer A;

[0010] Step S02, preparing a fluorosilicone polyurethane emulsion: adding dimethylolpropionic acid and into a four-necked flask, after completely dissolving, adding isophorone diisocyanate and 2 drops of dibutyltin dilaurate into the flask, reacting at 90°C for 3h, cooling to 70°C, mixing polyethylene glycol with acetone and adding into the flask, reacting for 2h, heating to 85°C, adding terminal hydroxyl fluorinated polysiloxane, adding an appropriate amount of acetone to control the viscosity, reacting for 2h, adding triethylamine into the flask, continuing the reaction for 3h, and removing the residual acetone by rotary evaporation to obtain a fluorosilicone polyurethane emulsion with a solid content of about 40%;

[0011] Step S03, modification of epoxy resin: emulsify the modified prepolymer A, fluorosilicone polyurethane emulsion, epoxy resin and polyethylene glycol with water, increase the rotation speed to 800 rpm, and emulsify to obtain a water-based modified epoxy resin;

[0012] Step S04, distillation under reduced pressure: heating the temperature to 70° C., distilling off acetone and water under reduced pressure, and controlling the solid content of the modified resin to be between 40% and 50%.

[0013] Preferably, the modified prepolymer A: fluorosilicone polyurethane emulsion: epoxy resin = 1-3:1-2:5, according to the solid content of 40%, the molecular weight of the modified epoxy resin obtained is 5.7×10 5 ~6.1×10 5.

[0014] Preferably, the epoxy value of the epoxy resin is 44, the molecular weight of the polyethylene glycol is 2000, and the molecular weight of the fluorosilicone polyurethane emulsion when the solid content is 40% is 5.9×10 5 ~6.2×10 5 .

[0015] Preferably, the preparation of the self-repairing microcapsules comprises the following steps:

[0016] Step S11, adding polyetheramine and isopropanol solvent into a four-necked flask, slowly heating to 60° C., adding 4,4'-diaminodiphenylmethane epoxy resin while stirring, mixing 4,4'-diaminodiphenylmethane epoxy resin and polyetheramine in a certain proportion, standing to remove bubbles, obtaining epoxyamine wall material, and maintaining the temperature at 65-85° C.;

[0017] Step S12, adding ammonium chloride and deionized water, adjusting the pH to 3.5 with hydrochloric acid in a water bath, reacting for 1.5 hours, and obtaining an epoxyamine wall material solution;

[0018] Step S13, mixing benzotriazole, dimer linoleic acid and tung oil in a certain proportion to obtain a core material, and maintaining the temperature at 10-15° C.;

[0019] Step S14, using a physical method to embed the core material in the wall material, adding the core material dropwise to the epoxy amine wall material solution, adding 10% OP-10 emulsifier based on the mass of the epoxy amine wall material, the reaction end point PH = 3.5, adding and continuing the reaction for 1.5h;

[0020] Step S15, after reacting for 30 minutes, the system temperature was raised to 60°C, and the reaction was continued for 1 hour before termination. The above reaction process was accompanied by mechanical stirring, and the rotation speed was controlled at 500 rpm. The slurry was naturally cooled, filtered, and dried, and the microcapsule powder was finally collected with a particle size of 50 to 120 μm.

[0021] Preferably, the model of the polyetheramine is D230, and the molar ratio of epoxy resin to polyetheramine is 1:2.0.

[0022] Preferably, the ratio of the core material is benzotriazole: dimer linoleic acid: tung oil = 1-2:2:5-7.

[0023] To achieve the purpose of the present invention, a metal anti-corrosion treatment method is provided, which specifically includes the following steps: first, the metal substrate is cleaned and polished, then a layer of primer is coated on the metal substrate, and then a layer of self-repairing microcapsules is added. After maintaining for 10 minutes, a coating mixture of self-repairing microcapsules with a concentration of 6%-8% is finally sprayed to obtain a surface coating of the metal substrate to complete the metal anti-corrosion treatment.

[0024] Preferably, the primer is a modified epoxy resin.

[0025] Principle of the invention: The self-repairing capsule provided by the present invention adopts epoxyamine material as the wall material, which is obtained by mixing 4,4′-diaminodiphenylmethane epoxy resin and polyetheramine in a certain proportion and standing to remove bubbles. The wall material has the performance of rapid solidification and can quickly form a stable capsule after contacting with the core material. At the same time, it is fragile and will be quickly broken by external force. The core material includes benzotriazole, dimer linoleic acid and tung oil. Benzotriazole and dimer linoleic acid can prevent the metal substrate from rusting. Tung oil can quickly take away the surface moisture because of its drying. Benzotriazole, dimer linoleic acid and tung oil have good synergistic effect and can The invention accelerates the rust prevention ability of the metal substrate surface. The epoxy resin material provided by the invention has good compatibility with the self-repairing microcapsules. The modified epoxy resin has toughness. The glass transition temperature of the modified epoxy resin is 131°C, the long-term use temperature is -10 to 40°C, the fracture toughness (KIC) is 1.75MPa·m1 / 2, and the strain energy release rate GIC is 0.683kJ / m2. The modified epoxy resin and the filler are physically blended to form an organic-inorganic synergistic toughening effect, while reducing the reaction active sites and improving the corrosion resistance of the metal in water. The metal preservative has excellent corrosion resistance.

[0026] Technical effects and advantages of the present invention:

[0027] The present invention adopts a combination of organic polymer materials and inorganic salts, and cooperates with self-repairing microcapsules to improve the smoke resistance and self-repairing ability of the coating. The prepared self-repairing microcapsule core wall is well combined with the modified epoxy resin. When cracks appear in the coating, due to the fragility of the capsule wall, the microcapsule quickly breaks, releases the core material, and bonds the cracks together. The self-repairing coating obtained after adding the self-repairing microcapsules can self-repair without external effects. When cracks appear in the coating, the wall material of the self-repairing microcapsule breaks and the core material flows out. The benzotriazole, dimerized linoleic acid, and tung oil therein can quickly repair cracks in the coating because of their anti-rust ability, drying film-forming properties, and adhesion.

[0028] Reference numerals

[0029] Figure 1 This is a microscopic image of the self-repairing microcapsule of the present invention.

[0030] Figure 2 This is the thermal performance curve of the self-repairing microcapsule of the present invention.

[0031] Figure 3 A graph showing the corrosion resistance of the self-repairing microcapsules of the present invention. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] Preparation Examples 1 to 3 are used to prepare self-repairing microcapsules, wherein the polyetheramine is polyetheramine D230, purchased from Jiangsu Qingquan Chemical Co., Ltd., 4,4′-diaminodiphenylmethane epoxy resin has an epoxy content of 122 and a functionality of about 3-3.5, purchased from Hunan Tuosuo Technology Co., Ltd., benzotriazole and dimerized linoleic acid are purchased from Nanjing Shunhengxin Chemical Co., Ltd., tung oil is purchased from Shanghai Gaote Chemical Co., Ltd., and OP-10 emulsifier is purchased from Tianjin Tongxin Chemical Co., Ltd. Preparation Example 4 is used to prepare modified epoxy resin, Example 1 is used to provide a formula of a metal preservative and a metal anticorrosion treatment method, and Experimental Examples 1 to 3 are used to characterize the performance and repair performance of the self-repairing microcapsules and verify the effect of the metal anticorrosion treatment method.

[0034] Preparation Example 1

[0035] A method for preparing a self-repairing microcapsule is provided, comprising the following steps:

[0036] Step S11, adding polyetheramine and isopropanol solvent into a four-necked flask, slowly heating to 60° C., adding 4,4'-diaminodiphenylmethane epoxy resin while stirring, and uniformly mixing 4,4'-diaminodiphenylmethane epoxy resin and polyetheramine in a weight ratio of 1:1.5, standing to remove bubbles, to obtain epoxyamine wall material, and maintaining the temperature at 65-85° C.;

[0037] Step S12, adding ammonium chloride and deionized water, adjusting the pH to 3.5 with hydrochloric acid in a water bath, reacting for 1.5 hours, and obtaining an epoxyamine wall material solution;

[0038] Step S13, mixing benzotriazole, dimer linoleic acid and tung oil in a ratio of 2:2:7 to obtain a core material, and maintaining the temperature at 10-15° C.;

[0039] Step S14, using a physical method to embed the core material in the wall material, adding the core material dropwise into the stable emulsion, maintaining the pH at 3.5, and continuing the reaction for 1.5 hours;

[0040] Step S15, after reacting for 30 minutes, the system temperature was raised to 60°C, and the reaction was continued for 1 hour before termination. The above reaction process was accompanied by mechanical stirring, and the rotation speed was controlled at 500 rpm. The slurry was naturally cooled, filtered, and dried, and the microcapsule powder was finally collected with a particle size of 50 to 120 μm.

[0041] Preparation Example 2

[0042] A method for preparing a self-repairing microcapsule is provided, comprising the following steps:

[0043] Step S11, add polyetheramine and isopropanol solvent into a four-necked flask, slowly heat up to 60°C, add 4,4'-diaminodiphenylmethane epoxy resin while stirring, mix 4,4'-diaminodiphenylmethane epoxy resin and polyetheramine in a weight ratio of 1.1.2, let stand to remove bubbles, obtain epoxyamine wall material, and maintain the temperature at 65-85°C;

[0044] Step S12, adding ammonium chloride and deionized water, adjusting the pH to 3.5 with hydrochloric acid in a water bath, reacting for 1.5 hours, and obtaining an epoxyamine wall material solution;

[0045] Step S13, mixing benzotriazole, dimer linoleic acid and tung oil in a ratio of benzotriazole: dimer linoleic acid: tung oil = 1:2:7 to obtain a core material, and maintaining the temperature at 10-15° C.;

[0046] Step S14, using a physical method to embed the core material in the wall material, adding the core material dropwise into the stable emulsion, maintaining the pH at 3.5, and continuing the reaction for 1.5 hours;

[0047] Step S15, after reacting for 30 minutes, the system temperature was raised to 60°C, and the reaction was continued for 1 hour before termination. The above reaction process was accompanied by mechanical stirring, and the rotation speed was controlled at 500 rpm. The slurry was naturally cooled, filtered, and dried, and the microcapsule powder was finally collected with a particle size of 50 to 120 μm.

[0048] Preparation Example 3

[0049] A method for preparing a self-repairing microcapsule is provided, comprising the following steps:

[0050] Step S11, adding polyetheramine and isopropanol solvent into a four-necked flask, slowly heating to 60° C., adding 4,4'-diaminodiphenylmethane epoxy resin while stirring, and uniformly mixing 4,4'-diaminodiphenylmethane epoxy resin and polyetheramine in a certain weight ratio of 1:1.5, standing to remove bubbles, to obtain epoxyamine wall material, and maintaining the temperature at 65-85° C.;

[0051] Step S12, adding ammonium chloride and deionized water, adjusting the pH to 3.5 with hydrochloric acid in a water bath, reacting for 1.5 hours, and obtaining an epoxyamine wall material solution;

[0052] Step S13, mixing benzotriazole, dimer linoleic acid and tung oil in a ratio of 2:2:5 to obtain a core material, and maintaining the temperature at 10-15° C.;

[0053] Step S14, using a physical method to embed the core material in the wall material, adding the core material dropwise into the stable emulsion, maintaining the pH at 3.5, and continuing the reaction for 1.5 hours;

[0054] Step S15, after reacting for 30 minutes, the system temperature was raised to 60°C, and the reaction was continued for 1 hour before termination. The above reaction process was accompanied by mechanical stirring, and the rotation speed was controlled at 500 rpm. The slurry was naturally cooled, filtered, and dried, and the microcapsule powder was finally collected with a particle size of 50 to 120 μm.

[0055] Preparation Example 4

[0056] A method for preparing a modified epoxy resin is provided, comprising the following steps:

[0057] Step S01, preparing modified prepolymer A: adding an appropriate amount of acetone to a four-necked bottle and heating it, and introducing condensed water and nitrogen, mixing toluene diisocyanate and polyethylene glycol as chain extenders in a certain proportion, and heating in a water bath at 40° C. to prepare modified prepolymer A;

[0058] Step S02, preparing a fluorosilicone polyurethane emulsion: adding dimethylolpropionic acid and into a four-necked flask, after completely dissolving, adding isophorone diisocyanate and 2 drops of dibutyltin dilaurate into the flask, reacting at 90°C for 3h, cooling to 70°C, mixing polyethylene glycol with acetone and adding into the flask, reacting for 2h, heating to 85°C, adding terminal hydroxyl fluorinated polysiloxane, adding an appropriate amount of acetone to control the viscosity, reacting for 2h, adding triethylamine into the flask, continuing the reaction for 3h, and removing the residual acetone by rotary evaporation to obtain a fluorosilicone polyurethane emulsion with a solid content of about 40%;

[0059] Step S03, modification of epoxy resin: emulsify the modified prepolymer A, fluorosilicone polyurethane emulsion, epoxy resin and polyethylene glycol with water, increase the rotation speed to 800 rpm, and emulsify to obtain a water-based modified epoxy resin;

[0060] Step S04, distillation under reduced pressure: heating the temperature to 70° C., distilling off acetone and water under reduced pressure, and controlling the solid content of the modified resin to be between 40% and 50%.

[0061] Example 1

[0062] The present embodiment provides a metal preservative, comprising 50 parts of modified epoxy resin, 8 parts of curing agent, 3 parts of auxiliary agent, 4 parts of self-repairing microcapsules, 12 parts of filler, and 26 parts of ionized water, wherein the filler is a mixture of barium sulfate and zinc sulfate in a ratio of 1:0.5, the auxiliary agent is a mixture of a wetting agent, a defoaming agent, a dispersant, and a diluent, the wetting agent is polyether-modified silicone oil; the defoaming agent is a polyether-type defoaming agent; the dispersant is an aqueous dispersant polyacrylate aqueous solution or polyethylene glycol; the diluent is propylene oxide butyl ether, the weight ratio of the wetting agent, the defoaming agent, the dispersant, and the diluent is 1:0.5:0.6:0.8, the curing agent is epoxyamine, the self-repairing microcapsules include a core material and a wall material, and the wall material: core material in the self-repairing microcapsules is 1.5:1, and the self-repairing microcapsules are prepared by the methods in the above-mentioned preparation examples 1-3 to obtain three metal preservatives A, B, and C.

[0063] The obtained A, B, and C metal preservatives are respectively coated on the metal substrate according to the following metal anticorrosion treatment method: first, the metal substrate is cleaned and polished, then a layer of modified epoxy resin primer is coated on the metal substrate, and then a layer of self-repairing microcapsules is added. After keeping it for 10 minutes, finally a coating mixture of self-repairing microcapsules with a concentration of 6%-8% is sprayed to obtain a metal substrate surface coating to complete the metal anticorrosion treatment.

[0064] Experimental Example 1

[0065] The images of the self-healing microcapsules were obtained by optical microscopy, e.g. Figure 1 As shown, the morphology of the self-repairing microcapsules is relatively uniform, the particle size is 50 to 120 μm, and the surface of the self-repairing microcapsules is relatively smooth.

[0066] The temperature range was from room temperature to 600°C with a heating rate of 10°C / min and the atmosphere was nitrogen. The self-repairing microcapsules obtained in Preparation Example 1 were marked as a, the self-repairing microcapsules obtained in Preparation Example 2 were marked as b, and the self-repairing microcapsules obtained in Preparation Example 3 were marked as c. The thermal properties were measured and the thermal performance curves were obtained as shown below: Figure 2 As shown, the obtained self-healing microcapsules have good thermal stability, and the thermal stability temperature is about 220°C.

[0067] Experimental Example 2

[0068] Verify the self-repairing performance of metal preservatives: According to GB923-88 "Surface rust grade and rust removal grade of steel materials before painting", grind the 125mmx0mmxmm tinplate with No. 0 sandpaper to BSt grade, and remove the dust and debris on the surface of the tinplate.

[0069] The metal preservatives A, B, and C obtained in Example 1 were brush-coated on the pretreated tinplate (the coating dry film thickness was about 150 μm). After curing for 3 days, two cross scratches were quickly made on the coating surface with a blade, and the scratch depth reached the interface between the coating and the metal substrate. The coated sample was placed at room temperature for 24 hours, and then immersed in a saturated Ca(OH)2 salt solution for 48 hours to obtain Figure 3 That is, the corrosion resistance performance diagram of self-repairing microcapsules. The control sample is a blank sample, that is, the preservative does not include self-repairing microcapsules. The results are shown on the first left, the test results of using type A metal preservative as the preservative are shown on the second left, the test results of using type B metal preservative as the preservative are shown on the third left, and the test results of using type C metal preservative as the preservative are shown on the fourth left. It can be seen from the figure that the metal preservative with the addition of self-repairing microcapsules has a repair function and can slow down metal corrosion.

[0070] Furthermore, the preservatives in the blank group are: 50 parts of modified epoxy resin, 8-12 parts of curing agent, 3-5 parts of auxiliary agent, 10-12 parts of filler, and 23-26 parts of ionized water. The filler is a mixture of barium sulfate and zinc sulfate in a ratio of 1:0.5 to 0.5:1. The auxiliary agent is one or more of a wetting agent, a defoaming agent, a dispersant and a diluent. The wetting agent is a polyether-modified silicone oil; the defoaming agent is a polyether-type defoaming agent; the dispersant is an aqueous dispersant polyacrylate aqueous solution or polyethylene glycol; the diluent is propylene oxide butyl ether, and the weight ratio of the wetting agent, defoaming agent, dispersant and diluent is 1:0-1.2:0-0.8:0-0.5, and the curing agent is epoxy amine.

[0071] Experimental Example 3

[0072] To verify the anti-corrosion performance of metal preservatives A, B, and C, steel directly coated with epoxy resin was used as control group 1, steel directly coated with a mixture of 50 parts of modified epoxy resin, 8 parts of curing agent, 5 parts of auxiliary agent, 10 parts of filler, and 23 parts of ionized water was used as control group 2, wherein the filler was a mixture of barium sulfate and zinc sulfate in a ratio of 1:0.5 to 0.5:1, steel directly coated with the above-mentioned metal preservative A was used as comparative example 1, and steel coated with the above-mentioned metal preservatives A, B, and C using the above-mentioned metal anticorrosion treatment method was used as comparative examples 2-4. The following table shows:

[0073]

[0074] Furthermore, the coating thickness of the blank group and the comparative example is the same, which is 500 μm. It can be seen from the table that the metal preservative provided by the present invention is best combined with the metal anticorrosion treatment method, and can achieve the purpose of anticorrosion of metals in an acid, alkali and salt environment.

[0075] The embodiments of the present invention merely provide one implementation mode, rather than specifically limiting the protection scope of the present invention.

[0076] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A metal preservative, characterized in that: It includes 50 parts of modified epoxy resin, 8-12 parts of curing agent, 3-5 parts of auxiliary agent, 4-8 parts of self-repairing microcapsules, 10-12 parts of filler, and 23-26 parts of ionized water. The filler is a mixture of barium sulfate and zinc sulfate in a ratio of 1:0.5 to 0.5:

1. The auxiliary agent is composed of a wetting agent, a defoaming agent, a dispersant and a diluent in a weight ratio of 1:0-1.2:0-0.8:0-0.

5. The wetting agent is polyether modified silicone oil; the defoaming agent is a polyether type defoaming agent. The dispersant is an aqueous dispersant polyacrylate aqueous solution or polyethylene glycol; the diluent is propylene oxide butyl ether, the curing agent is epoxyamine, the self-repairing microcapsule comprises a core material and a wall material, the wall material: core material in the self-repairing microcapsule is 1.5:1, the wall material is epoxyamine, and the core material is a mixture of tung oil, benzotriazole and dimerized linoleic acid; The preparation of the modified epoxy resin comprises the following steps: Step S01, preparing modified prepolymer A: adding an appropriate amount of acetone to a four-necked bottle and heating it, and introducing condensed water and nitrogen, mixing toluene diisocyanate and polyethylene glycol as chain extenders in a certain proportion, and heating in a water bath at 40° C. to prepare modified prepolymer A; Step S02, preparing a fluorosilicone polyurethane emulsion: adding dimethylolpropionic acid and into a four-necked flask, after completely dissolving, adding isophorone diisocyanate and 2 drops of dibutyltin dilaurate into the flask, reacting at 90°C for 3h, cooling to 70°C, mixing polyethylene glycol with acetone and adding into the flask, reacting for 2h, heating to 85°C, adding terminal hydroxyl fluorinated polysiloxane, adding an appropriate amount of acetone to control the viscosity, reacting for 2h, adding triethylamine into the flask, continuing the reaction for 3h, and removing the residual acetone by rotary evaporation to obtain a fluorosilicone polyurethane emulsion with a solid content of about 40%; Step S03, modification of epoxy resin: emulsify the modified prepolymer A, fluorosilicone polyurethane emulsion, epoxy resin and polyethylene glycol with water, increase the rotation speed to 800 rpm, and emulsify to obtain a water-based modified epoxy resin; Step S04, distillation under reduced pressure: heating the temperature to 70° C., distilling out acetone and water under reduced pressure, and controlling the solid content of the modified resin to be between 40% and 50%; The preparation of the self-repairing microcapsules comprises the following steps: Step S11, adding polyetheramine and isopropanol solvent into a four-necked flask, slowly heating to 60° C., adding 4,4'-diaminodiphenylmethane epoxy resin while stirring, mixing 4,4-diaminodiphenylmethane epoxy resin and polyetheramine in a certain proportion, standing to remove bubbles, obtaining epoxyamine wall material, and maintaining the temperature at 65-85° C.; Step S12, adding ammonium chloride and deionized water, adjusting the pH to 3.5 with hydrochloric acid in a water bath, reacting for 1.5 hours, and obtaining an epoxyamine wall material solution; Step S13, mixing benzotriazole, dimer linoleic acid and tung oil in a certain proportion to obtain a core material, and maintaining the temperature at 10-15° C.; Step S14, using a physical method to embed the core material in the wall material, adding the core material dropwise to the epoxy amine wall material solution, adding 10% OP-10 emulsifier based on the mass of the epoxy amine wall material, the reaction end point PH = 3.5, adding and continuing the reaction for 1.5h; Step S15, after reacting for 30 minutes, the system temperature was raised to 60°C, and the reaction was continued for 1 hour before termination. The above reaction process was accompanied by mechanical stirring, and the rotation speed was controlled at 500 rpm. The slurry was naturally cooled, filtered, and dried, and the microcapsule powder was finally collected with a particle size of 50 to 120 μm.

2. A metal anticorrosion agent according to claim 1, characterized in that: The modified prepolymer A: fluorosilicone polyurethane emulsion: epoxy resin = 1-3:1-2:5, according to the solid content of 40%, the molecular weight of the modified epoxy resin is 5.7×10 5 ~6.1×10 5 .

3. A metal anticorrosion agent according to claim 1, characterized in that: The epoxy value of the epoxy resin is 44, the molecular weight of the polyethylene glycol is 2000, and the molecular weight of the fluorosilicone polyurethane emulsion when the solid content is 40% is 5.9×10 5 ~6.2×10 5 .

4. A metal anticorrosion agent according to claim 1, characterized in that: The model of the polyetheramine is D230, and the molar ratio of the epoxy resin to the polyetheramine is 1:2.0.

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