CN106810993B - Self-healing type epoxy coating and its preparation and application based on the mesoporous container of micron order - Google Patents

Abstract

The invention relates to the field of self-healing coatings, in particular to a self-healing epoxy coating based on micron-sized mesoporous containers, a preparation method and application thereof. In terms of mass percentage, component 1 is prepared from the following components and mass ratio: 60%-80% epoxy resin; 1%-10% mesoporous container; 10%-30% organic solvent; 0.5% additive ~5%; in terms of mass percentage, component two is prepared from the following components and mass ratio: organic solvent 25% ~ 75%; curing agent 25% ~ 75%; in mass ratio, component one: group Divide into two = 2 ~ 4: 1 mix to obtain a self-healing epoxy coating containing mesoporous containers. The self-healing epoxy coating is sprayed, brushed or dipped on the surface of the substrate, cured at room temperature or heated to form a self-healing epoxy coating. When the coating prepared by adopting the coating of the invention is damaged (fracture, mechanical scraping), the metal base material can be corroded and repaired, so as to prolong the service life of the coating.

Description

Self-healing epoxy coatings based on micron-sized mesoporous containers and their preparation and application

technical field

The invention relates to the field of self-healing coatings, in particular to a self-healing epoxy coating based on micron-sized mesoporous containers and its preparation method and application. The coating prepared by using the coating can be damaged (fracture, mechanical scratch ), corrosion repair of metal substrates (such as: aluminum alloy, magnesium alloy, steel or galvanized steel, etc.).

Background technique

The self-healing technology of organic coatings includes two aspects: 1. The self-healing of the coating itself, that is, the use of resins or oligomers to heal coating defects caused by external damage; Self-healing of substrate corrosion. The significance of the latter is to increase the service life of the coating by slowing or preventing the occurrence of metal corrosion under the coating. Shchukin et al. first used nanoporous materials to load organic corrosion inhibitors, and used Layer-by-Layer technology to prepare polyelectrolyte films on the surface of porous materials that could be "opened" or "closed" in response to changes in the external pH value. Nanocontainers". The corrosion inhibitors released by porous materials can form a protective film on the metal surface through chemical reaction, physical adsorption or chemisorption to prevent the further occurrence of metal corrosion reaction. The carrier used as a corrosion inhibitor needs to have a strong adsorption capacity and a large specific surface area, so that more corrosion inhibitors can be absorbed.

So far, healing coatings containing corrosion inhibitors have been developed, mostly based on relatively thin sol-gel coatings (<5 μm). Sol-gel coatings are generally only available as surface treatments because of the thin coatings, which also limit the size of the corrosion inhibitor carrier. The smaller size of the container (nanoscale), in turn, limits the loading of corrosion inhibitors. Therefore, the ability of the container to provide effective corrosion protection is low. In this case, the amount and cost of nanoscale containers required to provide equivalent corrosion protection capabilities is high.

Contents of the invention

The object of the present invention is to provide a self-healing epoxy coating based on micron-sized mesoporous containers and its preparation method and application. The coating prepared by using the coating can repair the corrosion of the metal substrate when the coating is damaged.

In order to achieve the above object, technical scheme of the present invention is:

A self-healing epoxy coating based on micron-sized mesoporous containers. The coating is uniformly mixed with component 1 and component 2, wherein:

In terms of mass percentage, component one is prepared from the following components and mass ratio:

In terms of mass percentage, component 2 is prepared from the following components and mass ratio:

Organic solvent 25%～75%;

Curing agent 25% to 75%;

According to the mass ratio, the first component: the second component = 2-4:1 mixed to obtain the self-healing epoxy coating containing the mesoporous container.

For the self-healing epoxy coating based on micron-sized mesoporous containers, preferably, in terms of mass percentage, component one is prepared from the following components and mass ratio: the range of epoxy resin is 65% to 75%, the range of mesoporous container is 1% to 5%, the range of organic solvent is 20% to 30%, and the range of additives is 1% to 3%.

The self-healing epoxy coating based on the micron-scale mesoporous container, the mesoporous material used in the mesoporous container is micron-scale mesoporous silica, mesoporous titanium dioxide, mesoporous silicon carbide, mesoporous cerium oxide or mesoporous carbon.

In the self-healing epoxy coating based on micron-sized mesoporous containers, the epoxy resin is bisphenol A epoxy resin or bisphenol F epoxy resin, and the curing agent is an amine curing agent.

The self-healing epoxy coating based on the micron-scale mesoporous container, the preparation process of the mesoporous container is as follows:

(1) Disperse the organic corrosion inhibitor in water, an aqueous solution of ethanol or ethanol, and then add and uniformly disperse the mesoporous material in the above solution to form a mixed solution; in the mixed solution, by mass percentage, the mesoporous Materials account for 1-10%, organic corrosion inhibitors account for 0.1-10%, and the rest are water, ethanol aqueous solution or ethanol;

(2) At room temperature, vacuumize the mixed solution obtained in step (1), so that the organic corrosion inhibitor enters the mesoporous material; filter out the mesoporous material loaded with the organic corrosion inhibitor, and repeat the dispersion and vacuuming 3 to 4 times to maximize the amount of organic corrosion inhibitor entering the mesoporous material, and the mass ratio of mesoporous material to organic corrosion inhibitor is 1:1 to 10:1;

(3) filtering the mixed solution obtained in step (2) to obtain a mesoporous material loaded with an organic corrosion inhibitor;

(4) Based on the charged characteristics of the mesoporous material, disperse the mesoporous material loaded with an organic corrosion inhibitor obtained in step (3) into a polyelectrolyte solution with an opposite charge of 1 to 5 g/L, and mix with a shaker 15-30min to get the mixed solution;

(5) The mixed solution obtained in step (4) is filtered with a microfiltration membrane, washed, and excess charged polyelectrolytes are removed to obtain a mesoporous material coated with a single-layer polyelectrolyte;

(6) Disperse the charged mesoporous material coated with polyelectrolyte obtained in step (5) into 1-5 g/L polyelectrolyte solution with opposite charge, repeat and coat the polyelectrolyte for the first time The same steps are used to obtain a mesoporous container coated with a double-layer polyelectrolyte membrane.

The self-healing epoxy coating based on the micron-scale mesoporous container, in the preparation process of the mesoporous container, the organic corrosion inhibitor is 8-hydroxyquinoline, benzotriazole, mercaptobenzothiazole, methyl One of benzotriazole and imidazoline; the polyelectrolyte is polyacrylic acid, polyethyleneimine, sodium polystyrenesulfonate, polyallylamine hydrochloride, polydiallyldimethyl chloride A combination of two oppositely charged ammonium; the solvent used for the polyelectrolyte is water.

The preparation method of the self-healing epoxy coating based on the micron-scale mesoporous container, the specific steps are as follows:

1) Add epoxy resin, organic solvent, and additives to the container, disperse for 10-20 minutes with a high-speed disperser at 400-500 rpm, then add a mesoporous container, and continue to disperse with a high-speed centrifugal disperser at 800-1500 rpm for 10-30 minutes;

2) Grinding the material obtained in step 1) with a ball mill for 4 to 8 hours until the test fineness reaches below 20 μm, discharging and filtering to obtain component 1;

3) Dilute the curing agent into an organic solvent, disperse for 5-20 minutes with a high-speed disperser at 4000-5000 rpm, and discharge to obtain component 2;

4) Add component two to component one, stir well to form self-healing epoxy coating.

For the application of the self-healing epoxy coating based on the micron-scale mesoporous container, the self-healing epoxy coating is sprayed, brushed or dip-coated on the metal substrate: aluminum alloy, magnesium alloy, steel or plated On the surface of zinc steel, it can be cured at room temperature or heated to form a self-healing epoxy coating.

Design idea of the present invention is:

In order to reduce the preparation cost of the self-healing coating, the efficiency of the production process of the container should be improved while minimizing the amount of container used for the self-healing process. Usually, the epoxy coating applied to common anti-corrosion requirements has a coating film thickness of about tens to one hundred microns. For coatings of such thickness, micron-scale mesoporous materials are more efficient than nanoscale mesoporous materials. The invention includes the loading of corrosion inhibitors, the preparation of micron-scale mesoporous containers, and the preparation of self-healing coatings. The loading of corrosion inhibitors uses organic corrosion inhibitors as the object and micron-scale mesoporous materials as the main body. Filtration method, the adsorption and loading of organic corrosion inhibitors are completed in ethanol aqueous solution or aqueous solution; the mesoporous material loaded with corrosion inhibitors is coated with polyelectrolyte by layer-by-layer method to form a controllable Mesoporous "vessels" that release corrosion inhibitors; mesoporous vessels are doped into epoxy coatings to produce epoxy coatings that heal corrosion of metal substrates. Therefore, using micron-sized mesoporous materials as carriers can increase the loading capacity of corrosion inhibitors, reduce the cost of self-healing coatings, and improve the efficiency of corrosion healing of metal substrates. The mesoporous container with the function of controlling the release of corrosion inhibitors is used to prepare self-healing organic coatings, which improves the corrosion resistance of the coatings and prolongs the service life of the coatings.

Advantage of the present invention and beneficial effect are as follows:

1. Use micron-sized mesoporous materials to increase the loading capacity of mesoporous materials for corrosion inhibitors.

2. The method of the present invention based on the use of mesoporous containers to prepare self-healing coatings is simple, has good protection performance, low cost, and is easy to popularize.

Description of drawings:

Fig. 1(a)-Fig. 1(b) are pristine mesoporous SiO ₂ , the mesoporous container loaded with corrosion inhibitor and coated polyelectrolyte membrane. Among them, Fig. 1(a) is the end surface morphology of mesoporous _SiO2 ; Fig. 1(b) is the morphology of mesoporous _SiO2 container.

Figure 2(a)-Figure 2(b) is the surface morphology of the scratched epoxy coating after the salt spray test. Among them, Fig. 2(a) the surface morphology of epoxy coating after 1 day, 4 days and 10 days of salt spray test; Fig. 2(b) self-healing epoxy coating containing mesoporous _SiO2 container after salt spray test Surface morphology after 1 day, 4 days and 10 days of fog experiment.

Figure 3(a)-Figure 3(b) are the Bode plots of the electrochemical impedance spectroscopy of ordinary epoxy coatings and epoxy coatings containing mesoporous _SiO2 containers. Among them, Fig. 3(a) epoxy coating; Fig. 3(b) self-healing epoxy coating containing mesoporous _SiO2 containers. In the figure, the abscissa represents the frequency, the left ordinate represents the impedance modulus, and the right ordinate represents the phase angle.

Detailed ways

In the specific implementation process, the self-healing epoxy coating based on the micron-sized mesoporous container of the present invention is formed by uniformly mixing components 1 and 2:

In terms of mass percentage, component one is prepared from the following components and mass ratio:

In terms of mass percentage, component 2 is prepared from the following components and mass ratio:

Organic solvent 25%～75%;

Curing agent 25% to 75%;

According to the mass ratio, the first component: the second component = 2-4:1 mixed to obtain the self-healing epoxy coating containing the mesoporous container.

Wherein, the mesoporous material used in the mesoporous container may be micron-scale mesoporous silica, mesoporous titania, mesoporous silicon carbide, mesoporous cerium oxide, or mesoporous carbon. The epoxy resin is bisphenol A epoxy resin or bisphenol F epoxy resin, and the curing agent is an amine curing agent. The bisphenol A type epoxy resin can be E-12, E20, E44 or E54, and the bisphenol F type epoxy resin can be 6458, 6445, 6420 or 6412. Amine curing agents are aliphatic amines, aromatic amines, alicyclic amines or amide curing agents, aliphatic amines, such as: diethylenetriamine, triethylenetetramine or tetraethylenepentamine; aromatic amines, such as: m-phenylene Diamine or m-xylylenediamine; alicyclic amines, such as: isophorone diamine; amide curing agents, such as: Shanghai Kailin Paint Factory 200, 300, 650 or 651 polyamide, Tianjin Yan Polyamides of TY-200, TY203, TY-300, TY-3051, TY-600, TY-650 or TY651 from Sea Chemical Co., Ltd. Organic solvents are commonly used solvents for coatings, such as toluene, xylene, acetone, methyl ethyl ketone, cyclohexanone or n-butanol. Auxiliaries are commonly used additives for coatings, including wetting and dispersing agents, leveling agents or anti-settling agents, etc. BYK series additives from German BYK Chemical Company can be used; dispersants, such as: BYK101 dispersant, BYK104 dispersant, BYK110 dispersant, BYK130 dispersant, BYK141 dispersant or BYK161 dispersant, etc.; leveling agent, such as: BYK 358N leveling agent, BYK300 leveling agent, BYK306 leveling agent, BYK307 leveling agent, BYK310 leveling agent or BYK320 Leveling agent, etc.; anti-settling agent, such as: BYK 410 anti-settling agent, BYK 420 anti-settling agent, BYK 431 anti-settling agent or BYK 411 anti-settling agent, etc.

Unless otherwise specified in the present invention, the ratios involved are all percentages by mass.

Sample preparation method: After the surface of several 150mm×75mm× _2mm 2024-T3 aluminum alloy plates is degreased, spray one layer (dry film thickness is 40±2μm). Epoxy coatings on porous _SiO2 containers were dried at room temperature for 7 days, and the coating properties were tested.

The neutral salt spray sample of the coating sample adopts the YWQ salt spray box produced by Jiangsu Huaian Zhongya Test Equipment Co., Ltd. The concentration of NaCl solution is 5wt%, and the test temperature is 35±2°C.

The AC impedance test of the coating adopts EG&G 273A potentiostat and 5210 lock-in amplifier. Soaking solution: 3.5 wt% NaCl. Frequency range: 10mHz ~ 100KHz, disturbance potential: 20mV.

Hereinafter, the present invention will be further described in detail through examples and comparative examples.

Example 1

Step 1: Preparation of mesoporous micron-scale mesoporous _SiO2 container A

Dissolve the corrosion inhibitor 8-hydroxyquinoline in ethanol, then add mesoporous SiO ₂ (size ~ 1 μm), and mix thoroughly to form a mixed solution; in the mixed solution, the mesoporous material accounts for 1 wt%, organic corrosion Inhibitor accounts for 0.2wt%, and the rest is ethanol. At room temperature, 8-hydroxyquinoline was adsorbed in mesoporous SiO ₂ by vacuuming in a vacuum box. After standing still for 30 minutes, redisperse the mixed solution, and vacuum again. Repeat the above process four times until the ₈ -hydroxyquinoline is fully adsorbed in the mesoporous SiO. The obtained solution was taken out and filtered, and washed three times after filtration, and the obtained filtrate was used for layer-by-layer coating (Layer-by-Layer) polyelectrolyte.

Disperse the filtrate into 20 mL of aqueous solution, take 20 mL of 2 g/L polyethyleneimine (solvent is water) and mix with the filtrate to form a mixed solution, and incubate on a shaker for 15-30 min. The resulting suspension was filtered three times and washed three times to obtain polyethyleneimine-coated mesoporous SiO ₂ . Then take 20mL of 2g/L sodium polystyrene sulfonate (solvent is water) and mix with the filtrate obtained from the final filtration to form a mixed solution, and place it on a shaking table to incubate for 15-30min. The resulting suspension was filtered three times and washed three times to obtain mesoporous SiO ₂ coated with sodium polystyrene sulfonate. After filtration, the mesoporous _SiO2 container A coated with double-layer polyelectrolyte membrane was obtained, dried and set aside.

As shown in Figure 1(a)-Figure 1(b), it can be seen from the morphology of the end surface of mesoporous SiO ₂ and the morphology of the container of mesoporous SiO ₂ that the pristine mesoporous SiO ₂ loaded with corrosion inhibitor and coated polyelectrolyte film Afterwards, mesoporous containers are formed.

Step 2: Preparation of self-healing epoxy coating

The preparation method of component one: add bisphenol A epoxy resin E20 in dispersion tank and account for 72wt%, solvent xylene accounts for 25wt%, wetting and dispersing agent (Germany BYK chemical company DISPERBYK-163) accounts for 0.6wt%, flow The leveling agent (DISPERBYK-306 of BYK Chemical Company of Germany) accounts for 0.2wt%, and the anti-sedimentation agent (DISPERBYK-420 of BYK Chemical Company of Germany) accounts for 0.2wt%. Utilize a high-speed disperser at 450rpm to disperse for 15 minutes, then add mesoporous SiO ₂ Container A accounts for 2 wt%, and continue to disperse for 20 minutes with a high-speed centrifugal disperser at 1000 rpm. Grind the obtained material with a ball mill for 8 hours, and test the fineness to be below 20 μm, discharge and filter to obtain component 1;

Add curing agent TY-650 to the organic solvent toluene to dilute (dilute to 50wt% curing agent) as required, disperse at 4000-500rpm for 5-20 minutes with a high-speed disperser, and discharge to obtain component 2.

The two components are mixed according to the ratio of component one: component two = 3:1 (weight ratio), after stirring evenly, spray on the surface of 2024-T3 aluminum alloy substrate of 150mm×75mm×2mm, cure at room temperature for 7 days, dry film The thickness is 40±2μm.

Example 2

Step 1: Preparation of mesoporous micron-scale mesoporous _SiO2 container B

Dissolve the corrosion inhibitor benzotriazole in distilled water placed in a container, then put in mesoporous SiO ₂ (size ~ 1 μm), and mix thoroughly to form a mixed solution; in the mixed solution, the mesoporous material accounts for 1wt% , the organic corrosion inhibitor accounts for 0.2wt%, and the rest is water. At room temperature, the benzotriazole was adsorbed in the mesoporous SiO ₂ by vacuuming in the vacuum box. After standing still for 30 minutes, redisperse the mixed solution, and vacuum again. Repeat the above process _four times until the benzotriazole is fully adsorbed in the mesoporous SiO. The obtained solution was taken out and filtered, and washed three times after filtration, and the obtained filtrate was used for layer-by-layer coating (Layer-by-Layer) polyelectrolyte.

Disperse the filtrate into 20 mL of aqueous solution, take 20 mL of 2 g/L polyethyleneimine (solvent is water) and mix with the filtrate to form a mixed solution, and incubate on a shaker for 15-30 min. The resulting suspension was filtered three times and washed three times to obtain polyethyleneimine-coated mesoporous SiO ₂ . Then take 20mL of 2g/L sodium polystyrene sulfonate (solvent is water) and mix with the filtrate obtained from the final filtration to form a mixed solution, and place it on a shaking table to incubate for 15-30min. The resulting suspension was filtered three times and washed three times to obtain mesoporous SiO ₂ coated with sodium polystyrene sulfonate. After filtration, the mesoporous SiO container B coated with _double -layer polyelectrolyte membrane was obtained, dried and set aside.

As shown in Figure 1(a)-Figure 1(b), it can be seen from the morphology of the end surface of mesoporous SiO ₂ and the morphology of the container of mesoporous SiO ₂ that the pristine mesoporous SiO ₂ loaded with corrosion inhibitor and coated polyelectrolyte film Afterwards, mesoporous containers are formed.

Step 2: Preparation of self-healing epoxy coating

The preparation method of component one: add bisphenol A epoxy resin E20 in dispersion tank and account for 72wt%, solvent xylene accounts for 25wt%, wetting and dispersing agent (Germany BYK chemical company DISPERBYK-163) accounts for 0.6wt%, flow The leveling agent (DISPERBYK-306 of BYK Chemical Company of Germany) accounts for 0.2wt%, and the anti-sedimentation agent (DISPERBYK-420 of BYK Chemical Company of Germany) accounts for 0.2wt%. Utilize a high-speed disperser at 480rpm to disperse for 10 minutes, then add mesoporous SiO ₂ Container B accounted for 2wt%, and continued to disperse for 15 minutes with a high-speed centrifugal disperser at 1200 rpm. Grind the obtained material with a ball mill for 6 hours, test the fineness to be below 20 μm, discharge and filter to obtain component 1;

Add curing agent TY-650 to the organic solvent toluene to dilute (dilute to 50wt% curing agent) as required, disperse at 4000-500rpm for 5-20 minutes with a high-speed disperser, and discharge to obtain component 2.

The two components are mixed according to the ratio of component one: component two = 3:1 (weight ratio), after stirring evenly, spray on the surface of 2024-T3 aluminum alloy substrate of 150mm×75mm×2mm, cure at room temperature for 7 days, dry film The thickness is 40±2μm.

Comparative example 1

The preparation method of component one: add bisphenol A epoxy resin E20 in dispersion tank and account for 73wt%, solvent xylene accounts for 26wt%, wetting and dispersing agent (Germany BYK chemical company DISPERBYK-163) accounts for 0.6wt%, flow The leveling agent (DISPERBYK-306, BYK Chemical Company, Germany) accounted for 0.2wt%, and the anti-sedimentation agent (DISPERBYK-420, BYK Chemical Company, Germany) accounted for 0.2wt%, and was dispersed by a high-speed disperser at 450rpm for 15 minutes. Grind the obtained material with a ball mill for 8 hours, and test the fineness to be below 20 μm, discharge and filter to obtain component 1;

Add curing agent TY-650 to the organic solvent toluene to dilute (dilute to 50wt% curing agent) as required, disperse at 4000-500rpm for 5-20 minutes with a high-speed disperser, and discharge to obtain component 2.

The two components are mixed according to the ratio of component one: component two = 3:1 (weight ratio), after stirring evenly, spray on the surface of 2024-T3 aluminum alloy substrate of 150mm×75mm×2mm, cure at room temperature for 7 days, dry film The thickness is 40±2μm.

The results of the 10-day neutral salt spray test and the 7-day electrochemical AC impedance are shown in Table 1 and Figure 2(a)-Figure 2(b). From Table 1 and Fig. 2(a)-Fig. 2(b), it can be seen that the salt spray resistance of the epoxy coating sample added to the mesoporous container in Examples 1 and 2 is obviously better than that of the ordinary epoxy coating in Comparative Example 1. Layer samples. Moreover, the low-frequency impedance modulus of the epoxy coatings added with mesoporous containers (Examples 1 and 2) is also significantly higher than that of ordinary epoxy coatings (Comparative Example 1). It can be seen from Figure 3(a)-Figure 3(b) that the impedance modulus of the epoxy coating containing mesoporous containers increases gradually with the increase of immersion time in 3.5wt% NaCl solution, indicating that the release of corrosion inhibitors has a negative effect on the coating. Self-healing of underlying substrate corrosion.

The test result of embodiment 1,2 and comparative example 1 is as follows:

Table 1 Corrosion resistance evaluation of epoxy coating

Salt spray resistance (grade) Low frequency impedance modulus (ohm cm²) Example 1 0 &gt;10⁸ Example 2 0 &gt;10⁸ Comparative example 1 1 &lt;10⁶

The results of Examples and Comparative Examples show that the present invention proposes a self-healing epoxy coating based on micron-scale mesoporous materials, and the corrosion resistance of the epoxy coating is significantly improved by adding micron-scale mesoporous containers.

Claims (6)

1. A self-healing epoxy coating based on micron-scale mesoporous containers, characterized in that the coating is uniformly mixed from component one and component two, wherein: In terms of mass percentage, component one is prepared from the following components and mass ratio: Epoxy resin 60%~80%; Mesoporous container 1%~10%; Organic solvent 10%~30%; Auxiliary 0.5% ~ 5%; In terms of mass percentage, component 2 is prepared from the following components and mass ratio: Organic solvent 25%～75%; Curing agent 25% ~ 75%; According to the mass ratio, component 1: component 2 = 2 ~ 4: 1 mixed to obtain a self-healing epoxy coating containing mesoporous containers; The preparation process of the mesoporous container is as follows: (1) Disperse the organic corrosion inhibitor in water, ethanol aqueous solution or ethanol, then add the mesoporous material and evenly disperse in the above solution to form a mixed solution; in the mixed solution, the mesoporous Materials account for 1-10%, organic corrosion inhibitors account for 0.1-10%, and the rest are water, ethanol aqueous solution or ethanol; (2) At room temperature, vacuumize the mixture obtained in step (1) to allow the organic corrosion inhibitor to enter the mesoporous material; filter out the mesoporous material loaded with the organic corrosion inhibitor, and repeat the dispersion and vacuuming 3 to 4 times to maximize the amount of organic corrosion inhibitor entering the mesoporous material, and the mass ratio of mesoporous material to organic corrosion inhibitor is 1:1 to 10:1; (3) filtering the mixed solution obtained in step (2) to obtain a mesoporous material loaded with an organic corrosion inhibitor; (4) Based on the charged characteristics of mesoporous materials, disperse the mesoporous materials loaded with organic corrosion inhibitors obtained in step (3) into 1-5 g/L polyelectrolyte solution with opposite charges, and mix with a shaker 15-30min to get the mixed solution; (5) Filtrating the mixed solution obtained in step (4) with a microfiltration membrane, washing, removing excess charged polyelectrolyte, and obtaining a mesoporous material coated with a single layer of polyelectrolyte; (6) Disperse the charged mesoporous material coated with polyelectrolyte obtained in step (5) into 1-5 g/L polyelectrolyte solution with opposite charge, repeat and coat the polyelectrolyte for the first time The same steps, that is, to obtain a mesoporous container coated with a double-layer polyelectrolyte membrane; In the preparation process of the mesoporous container, the organic corrosion inhibitor is one of 8-hydroxyquinoline, mercaptobenzothiazole, and imidazoline; the polyelectrolyte is polyacrylic acid, polyethyleneimine, sodium polystyrenesulfonate, poly Allylamine hydrochloride, a combination of two oppositely charged polydiallyldimethylammonium chloride; the solvent used in the polyelectrolyte is water. 2. The self-healing epoxy coating based on micron-scale mesoporous containers according to claim 1, characterized in that, by mass percentage, component one is formulated from the following components and mass ratio: epoxy The range of resin is 65%-75%, the range of mesoporous container is 1%-5%, the range of organic solvent is 20%-30%, and the range of additive is 1%-3%. 3. the self-healing epoxy coating based on micron-scale mesoporous container according to claim 1, is characterized in that, the mesoporous material that mesoporous container uses is micron-scale mesoporous silicon dioxide, mesoporous titanium dioxide, Mesoporous silicon carbide, mesoporous cerium oxide or mesoporous carbon. 4. the self-healing epoxy coating based on micron-scale mesoporous container according to claim 1, is characterized in that, epoxy resin is bisphenol A type epoxy resin or bisphenol F type epoxy resin, curing agent It is an amine curing agent. 5. a kind of preparation method of the self-healing type epoxy coating based on micron mesoporous container claimed in claim 1, is characterized in that, concrete steps are as follows: 1) Add epoxy resin, organic solvent, and additives to the container, disperse for 10-20 minutes with a high-speed disperser at 400-500 rpm, then add a mesoporous container, and continue to disperse with a high-speed centrifugal disperser at 800-1500 rpm for 10-30 minutes minute; 2) Grind the material obtained in step 1) with a ball mill for 4 to 8 hours until the test fineness reaches below 20 μm, discharge and filter to obtain component 1; 3) Add the curing agent to the organic solvent for dilution, use a high-speed disperser at 4000-5000 rpm to disperse for 5-20 minutes, and discharge to obtain component 2; 4) Add component two to component one, stir well to form self-healing epoxy coating. 6. a kind of application of the self-healing type epoxy coating based on micron mesoporous container as claimed in claim 1, is characterized in that, self-healing type epoxy coating is sprayed, brushed or dip-coated on the aluminum alloy , magnesium alloy or galvanized steel surface, cured at room temperature or heated to form a self-healing epoxy coating.