Modified phytic acid doped nano Al2O3 metal anticorrosive paint and preparation method thereof

Abstract

The invention discloses a modified phytic acid doped nano Al2O3 metal anticorrosive paint and a preparation method thereof, and belongs to the technical field of metal preservatives. The metal anticorrosive paint is prepared from the following components in parts by weight: 75 to 85 parts of epoxy resin, 8 to 12 parts of a curing agent, 3 to 6 parts of modified phytic acid, 0.8 to 9 parts of nano Al2O3, 0.5 to 2 parts of a flatting agent and 5 to 30 parts of a solvent. The modified phytic acid in the obtained anticorrosive paint has high negative charges on the surface, so that the modified phytic acid can be chelated with metal ions to form a layer of compact monomolecular protective film, the corrosion of metal can be effectively delayed, and meanwhile, the nano Al2O3 particles have a nano particle effect and can also provide an excellent physical shielding effect; and the coating has good mechanical properties, self-repairing performance and anti-corrosion performance.

Description

Technical Field

[0001] The invention belongs to the technical field of metal anticorrosive agents, and in particular relates to a metal anticorrosive coating doped with modified phytic acid and nano-Al2O3 and a preparation method thereof. Background Art

[0002] Metal corrosion is widely present in all areas of people's production and life, seriously affecting the development of all walks of life. It occurs between metal materials and the external environment. Metal corrosion protection has become a global problem.

[0003] Among the many anti-corrosion methods, anti-corrosion coatings have always occupied an important position due to their wide adaptability, simple construction, low cost, significant effect, and convenient maintenance, and have become the most widely used metal protection method. Epoxy resin is one of the most important ingredients in anti-corrosion coatings, and they play a role in bonding and gelling in the coating. Composite anti-corrosion coatings with epoxy resin as the main component, in addition to epoxy resin, also have curing agents, fillers, solvents, additives, etc.

[0004] Phytic acid is a natural polymer that is used in the preparation of anti-corrosion coatings. When phytic acid is complexed with metals, the resulting complex ring can form a dense monomolecular protective film on the metal surface, which can effectively inhibit the penetration of corrosive ions and delay the corrosion of metals. However, phytic acid has poor compatibility. When phytic acid is directly introduced into epoxy resin coatings, phytic acid is easily precipitated in the epoxy resin matrix. In addition, the monomolecular protective film formed by phytic acid and metal has low mechanical strength. Once it is damaged, its protective performance will be greatly weakened due to its lack of self-repairing properties. Summary of the invention

[0005] [Technical issues]

[0006] The technical problem to be solved by the present invention is that the compatibility of phytic acid is poor, the mechanical strength of the anti-corrosion coating formed is low, and the coating does not have self-repairing ability.

[0007] [Technical solution]

[0008] In order to solve the above problems, the present invention provides a metal anticorrosion coating doped with modified phytic acid nano-Al2O3 and a preparation method thereof. The modified phytic acid in the obtained anticorrosion coating can chelate with a variety of metal ions to form a dense monomolecular protective film due to its high negative charge on the surface, which can effectively delay the corrosion of metals. At the same time, the nanoparticle effect of nano-Al2O3 particles can also provide excellent physical shielding effect. The addition of nano-Al2O3 particles not only fills part of the pores, but also promotes the density of the coating through its high surface energy and active sites, thereby improving the overall performance of the coating and helping to promote the repair of the resin matrix when the coating is damaged. The anticorrosion coating obtained by the present invention has good mechanical properties, self-repairing properties and anticorrosion properties.

[0009] The present invention provides a metal anticorrosion coating doped with modified phytic acid nano-Al2O3, which comprises the following components in parts by weight:

[0010] Epoxy resin 75-85 parts, curing agent 8-12 parts, modified phytic acid 3-6 parts, nano-Al2O3 0.8-9 parts, leveling agent 0.5-2 parts, solvent 5-30 parts.

[0011] As an embodiment of the present invention, the modified phytic acid doped nano-Al2O3 metal anti-corrosion coating comprises the following components in parts by weight: 75-85 parts of epoxy resin, 8-12 parts of curing agent, 3-5 parts of modified phytic acid, 0.8-7.2 parts of nano-Al2O3, 0.5-2 parts of leveling agent, and 5-20 parts of solvent.

[0012] As an embodiment of the present invention, the epoxy resin is a bisphenol A epoxy resin, and the epoxy value is one or more of 0.42eq / 100g, 0.44eq / 100g, and 0.51eq / 100g.

[0013] As an embodiment of the present invention, the curing agent is diethylenetriamine.

[0014] As an embodiment of the present invention, the leveling agent is one or more of polydimethylsiloxane, polyether-modified polydimethylsiloxane, polymethylphenylsiloxane, and alkyl-modified organic siloxane.

[0015] As an embodiment of the present invention, the solvent is acetone.

[0016] As an embodiment of the present invention, the preparation method of the modified phytic acid comprises the following steps:

[0017] S1. Mix 0.3-0.7 g of phytic acid and 4-7.5 g of propylene glycol methyl ether, and stir at a speed of 450-700 r / min for 30 min to ensure that the phytic acid is completely and evenly dispersed in the propylene glycol methyl ether to obtain a phytic acid mixed solution;

[0018] S2, 9-11.5 g of ethylene glycol diglycidol and the phytic acid in S1 are uniformly mixed, and stirring is continued at a speed of 300-450 r / min for 15-25 min;

[0019] S3. Finally, 0.1 to 0.35 g of tetrabutylammonium bromide is added as a catalyst, and the reaction is carried out at 85 to 95° C. for 1 to 1.5 hours to finally obtain modified phytic acid.

[0020] The invention provides a method for preparing a metal anticorrosion coating doped with modified phytic acid and nano-Al2O3. The method specifically comprises the following steps: mixing 75-85 parts of epoxy resin and 5-30 parts of solvent evenly by weight, adding 3-6 parts of modified phytic acid, and then adding 8-12 parts of curing agent, 0.5-2 parts of leveling agent and 0.8-9 parts of nano-Al2O3, and performing ultrasound to uniformly disperse the nano-Al2O3 in the coating system, so as to finally obtain the metal anticorrosion coating doped with modified phytic acid and nano-Al2O3.

[0021] The present invention provides an application of the modified phytic acid-doped nano-Al2O3 metal anticorrosion coating in the field of metal anticorrosion.

[0022] The present invention also provides a metal anticorrosion treatment method, which uses an automatic coating machine to evenly coat the modified phytic acid-doped nano-Al2O3 metal anticorrosion coating on a pretreated metal substrate, performs 2 to 8 scraping operations to ensure the uniformity and consistency of the coating, and cures the coated metal substrate at a temperature of 60 to 85°C.

[0023] As an embodiment of the present invention, a method for treating a pretreated metal substrate includes: first cleaning and drying the metal substrate, polishing the cleaned metal substrate with sandpaper, and after polishing, cleaning and drying it again to remove tiny particles that may be generated during the polishing process to ensure a clean surface.

[0024] [Beneficial Effects]

[0025] (1) The modified phytic acid in the anti-corrosion coating obtained by the present invention can chelate with various metal ions to form a dense monomolecular protective film due to its high negative charge on the surface, which can effectively delay the corrosion of metals. At the same time, the nano-particle effect of the nano-Al2O3 particles can also provide excellent physical shielding effect, so that the substrate and the environment are isolated and protected from environmental corrosion;

[0026] (2) The present invention solves the problem that the compatibility of phytic acid is poor and phytic acid is easily precipitated in the epoxy resin matrix when phytic acid is directly introduced into the epoxy resin coating by modifying the phytic acid;

[0027] (3) Adding modified phytic acid and nano-Al2O3 particles to the coating can not only improve the mechanical properties of the coating, but also the addition of nanofillers fills some of the pores and may promote the density of the coating through its high surface energy and active sites, thereby improving the overall performance of the coating and helping to promote the repair of the resin matrix when the coating is damaged. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the surface microscopic morphology of the metal anticorrosion coating doped with nano-Al2O3 modified by phytic acid in Example 3;

[0029] Figure 2 This is a polarization curve diagram of the anti-corrosion performance of the metal anti-corrosion coating doped with nano-Al2O3 modified by phytic acid in Example 3;

[0030] Figure 3 This is a self-repairing performance effect diagram of the metal anti-corrosion coating doped with modified phytic acid nano-Al2O3 in Example 3, (a) is the surface micromorphology before repair, and (b) is the surface micromorphology after repair. DETAILED DESCRIPTION

[0031] The nano-Al2O3 used in the embodiment of the present invention was purchased from Shanghai Myrel Biochemical Technology Co., Ltd., α phase, with a particle size of 30 nm.

[0032] The technical solution of the present invention is further described in detail below in conjunction with specific implementation methods.

[0033] In the following examples, 1 part by weight means 0.1 g.

[0034] The anti-corrosion coating obtained in the example was subjected to surface microscopic morphology analysis, glossiness test, impact resistance test, adhesion test, hardness test and anti-corrosion performance test according to the following methods.

[0035] Microstructure: Scanning electron microscopy (SEM) was used to observe the microstructure of the anti-corrosion coating.

[0036] Glossiness: The glossiness of the anti-corrosion coating was measured using a YG60L gloss meter. To ensure the accuracy and reliability of the data, each sample was tested 5 times independently. After all the tests were completed, the average value of the 5 test results was calculated and taken as the final glossiness index.

[0037] Impact resistance: Test the impact resistance of the coating with reference to GB / T 1732-93 film impact resistance determination method. Place the painted test plate flat on the anvil with the paint film facing upwards. The impacted part of the test plate should be at least 15mm away from the edge, and the distance between the edges of each impact point should not be less than 15mm. The weight is fixed at 100cm of the slide by the control device. The weight is 1kg. Press the control button and the weight will fall freely on the punch. Lift the weight and take out the test plate. Record the height of the weight falling on the test plate. Carry out the impact test 3 times on the same test plate.

[0038] Scratch self-repair: Use a scratch knife to scratch the coating, so that the scratch penetrates the entire coating, and observe the scratch under an optical microscope. Then place the damaged coating in an 80℃ oven to heal for 4 hours, take it out and observe the healing of the coating scratch under an optical microscope.

[0039] Adhesion: The adhesion of the anti-corrosion coating is measured by using a BGD502 series paint film cross-cutting device; specifically, a special scratching tool is used to perform a cross-cutting test at a 45° angle to the sample surface to form a cross-grid pattern. After the cross-cutting is completed, the tape is evenly applied to the coating surface, and then the tape is torn off at a uniform speed. After the tape is torn off, the grid area on the coating surface is carefully observed with a magnifying glass to check whether there is any paint film peeling or shedding. The adhesion of the coating is evaluated based on the observed paint film peeling. Level 0: The cutting edge is completely smooth, without any peeling; Level 1: A little coating peels off at the intersection of the cuts, but the affected cross-cut area cannot be significantly greater than 5%; Level 2: The coating peels off at the intersection of the cuts and / or along the edges of the cuts, and the affected cross-cut area is significantly greater than 5%, but not significantly greater than 15%; Level 3: The coating partially or completely peels off in large pieces along the cutting edge, and / or partially or completely peels off at different parts of the grid, and the affected cross-cut area is significantly greater than 15%, but not significantly greater than 35%; Level 4: The coating peels off in large pieces along the cutting edge, and / or some squares partially or completely peel off. The affected cross-cut area is significantly greater than 35%, but not significantly greater than 65%; Level 5: The degree of peeling exceeds Level 4.

[0040] Hardness: The hardness of the anti-corrosion coating is evaluated by the manual pencil hardness test method. Pencils of different hardness levels are sharpened and inserted into the experimental instrument. They are fixed with a clamp to ensure that the tip of the pencil contacts the coating surface. The tip of the pencil should lightly touch the surface of the paint film, and the test plate should be pushed on the coating at a speed of 0.5 to 1.0 mm / s, for a distance of at least 7 mm. The depth and width of the pencil scratches are checked, and the hardness level of the coating is evaluated according to the hardness level of the pencil and the degree of damage to the coating.

[0041] Anti-corrosion performance: The anti-corrosion performance of the anti-corrosion coating was tested using a CS310H electrochemical workstation; specifically, the sample was cleaned and cut into a size of 1 cm × 1 cm to remove possible impurities or contaminants on the surface, and the electrolyte used was a sodium chloride (NaCl) solution with a mass fraction of 3.5% to ensure the accuracy of the test.

[0042] Example 1

[0043] The present embodiment provides a metal anticorrosion coating doped with modified phytic acid and nano-Al2O3, which comprises the following components in parts by weight: 80 parts of bisphenol A epoxy resin with an epoxy value of 0.42eq / 100g, 10 parts of diethylenetriamine, 4 parts of modified phytic acid, 0.8 parts of nano-Al2O3, 1 part of polydimethylsiloxane, and 10 parts of acetone.

[0044] The specific method for preparing the metal anticorrosion coating of modified phytic acid doped nano-Al2O3 is as follows:

[0045] (1) Preparation of modified phytic acid:

[0046] S1, 0.5g phytic acid and 5.5g propylene glycol methyl ether were mixed, and stirred at a speed of 600r / min for 30min to ensure that the phytic acid was completely and evenly dispersed in the propylene glycol methyl ether to obtain a phytic acid mixed solution;

[0047] S2, 10.25g of ethylene glycol diglycidol was mixed evenly with the phytic acid in S1, and stirring was continued at a speed of 400r / min for 20min;

[0048] S3, finally adding 0.2 g of tetrabutylammonium bromide as a catalyst, reacting at 90° C. for 1 h, and finally obtaining modified phytic acid;

[0049] (2) Preparation of metal anticorrosion coatings doped with modified phytic acid and nano-Al2O3:

[0050] S1, weighing 80 parts of bisphenol A epoxy resin with an epoxy value of 0.42 eq / 100 g and 10 parts of acetone, and mixing them until uniform; then adding 4 parts of modified phytic acid, and continuing to stir;

[0051] S2. Finally, add the required curing agent diethylenetriamine 10 parts, leveling agent polydimethylsiloxane 1 part and 0.8 parts of nano-Al2O3 in sequence, and ensure that all ingredients are fully mixed with the assistance of ultrasound to make the nano-Al2O3 evenly dispersed in the coating system, and finally obtain the metal anti-corrosion coating doped with modified phytic acid nano-Al2O3.

[0052] Example 2

[0053] The present embodiment provides a metal anticorrosion coating doped with modified phytic acid and nano-Al2O3, which includes the following components by weight: 80 parts of bisphenol A epoxy resin with an epoxy value of 0.42eq / 100g, 10 parts of diethylenetriamine, 4 parts of modified phytic acid, 2.4 parts of nano-Al2O3, 1 part of polydimethylsiloxane, and 10 parts of acetone.

[0054] The specific method for preparing the metal anticorrosion coating of modified phytic acid doped nano-Al2O3 is as follows:

[0055] (1) Preparation of modified phytic acid:

[0056] S1, 0.5g phytic acid and 5.5g propylene glycol methyl ether were mixed, and stirred at a speed of 600r / min for 30min to ensure that the phytic acid was completely and evenly dispersed in the propylene glycol methyl ether to obtain a phytic acid mixed solution;

[0057] S2, 10.25 g of ethylene glycol diglycidol was mixed evenly with the phytic acid in S1, and stirring was continued at a speed of 400 r / min for 20 minutes;

[0058] S3, finally adding 0.2 g of tetrabutylammonium bromide as a catalyst, reacting at 90° C. for 1 h, and finally obtaining modified phytic acid;

[0059] (2) Preparation of metal anticorrosion coatings doped with modified phytic acid and nano-Al2O3:

[0060] S1, weighing 80 parts of bisphenol A epoxy resin with an epoxy value of 0.42 eq / 100 g and 10 parts of acetone, and mixing them until uniform; then adding 4 parts of modified phytic acid, and continuing to stir;

[0061] S2. Finally, add the required curing agent diethylenetriamine 10 parts, leveling agent polydimethylsiloxane 1 part and 2.4 parts of nano-Al2O3 in sequence, and ensure that all ingredients are fully mixed with the assistance of ultrasound to make the nano-Al2O3 evenly dispersed in the coating system, and finally obtain the metal anti-corrosion coating doped with modified phytic acid nano-Al2O3.

[0062] Example 3

[0063] The present embodiment provides a metal anticorrosion coating doped with modified phytic acid and nano-Al2O3, which includes the following components by weight: 80 parts of bisphenol A epoxy resin with an epoxy value of 0.42eq / 100g, 10 parts of diethylenetriamine, 4 parts of modified phytic acid, 4 parts of nano-Al2O3, 1 part of polydimethylsiloxane, and 10 parts of acetone.

[0064] The specific method for preparing the metal anticorrosion coating of modified phytic acid doped nano-Al2O3 is as follows:

[0065] (1) Preparation of modified phytic acid:

[0066] S1, 0.5g phytic acid and 5.5g propylene glycol methyl ether were mixed, and stirred at a speed of 600r / min for 30min to ensure that the phytic acid was completely and evenly dispersed in the propylene glycol methyl ether to obtain a phytic acid mixed solution;

[0067] S2, 10.25g of ethylene glycol diglycidol was mixed evenly with the phytic acid in S1, and stirring was continued at a speed of 400r / min for 20min;

[0068] S3, finally adding 0.2 g of tetrabutylammonium bromide as a catalyst, reacting at 90° C. for 1 h, and finally obtaining modified phytic acid;

[0069] (2) Preparation of metal anticorrosion coatings doped with modified phytic acid and nano-Al2O3:

[0070] S1, weighing 80 parts of bisphenol A epoxy resin with an epoxy value of 0.42 eq / 100 g and 10 parts of acetone, and mixing them until uniform; then adding 4 parts of modified phytic acid, and continuing to stir;

[0071] S2. Finally, add the required curing agent diethylenetriamine 10 parts, leveling agent polydimethylsiloxane 1 part and 4 parts of nano-Al2O3 in sequence, and ensure that all ingredients are fully mixed with the assistance of ultrasound to make the nano-Al2O3 evenly dispersed in the coating system, and finally obtain the metal anti-corrosion coating doped with modified phytic acid nano-Al2O3.

[0072] Example 4

[0073] The present embodiment provides a metal anticorrosion coating doped with modified phytic acid and nano-Al2O3, which comprises the following components in parts by weight: 80 parts of bisphenol A epoxy resin with an epoxy value of 0.42eq / 100g, 10 parts of diethylenetriamine, 4 parts of modified phytic acid, 5.6 parts of nano-Al2O3, 1 part of polydimethylsiloxane, and 10 parts of acetone.

[0074] The specific method for preparing the metal anticorrosion coating of modified phytic acid doped nano-Al2O3 is as follows:

[0075] (1) Preparation of modified phytic acid:

[0076] S1, 0.5g phytic acid and 5.5g propylene glycol methyl ether were mixed, and stirred at a speed of 600r / min for 30min to ensure that the phytic acid was completely and evenly dispersed in the propylene glycol methyl ether to obtain a phytic acid mixed solution;

[0077] S2, 10.25g of ethylene glycol diglycidol was mixed evenly with the phytic acid in S1, and stirring was continued at a speed of 400r / min for 20min;

[0078] S3, finally adding 0.2 g of tetrabutylammonium bromide as a catalyst, reacting at 90° C. for 1 hour, and finally obtaining modified phytic acid;

[0079] (2) Preparation of metal anticorrosion coatings doped with modified phytic acid and nano-Al2O3:

[0080] S1, weighing 80 parts of bisphenol A epoxy resin with an epoxy value of 0.42 eq / 100 g and 10 parts of acetone, and mixing them until uniform; then adding 4 parts of modified phytic acid, and continuing to stir;

[0081] S2. Finally, add the required curing agent diethylenetriamine 10 parts, leveling agent polydimethylsiloxane 1 part and 5.6 parts of nano-Al2O3 in sequence, and ensure that all ingredients are fully mixed with the assistance of ultrasound to make the nano-Al2O3 evenly dispersed in the coating system, and finally obtain the metal anti-corrosion coating doped with modified phytic acid nano-Al2O3.

[0082] Example 5

[0083] The present embodiment provides a metal anticorrosion coating doped with modified phytic acid and nano-Al2O3, which comprises the following components in parts by weight: 80 parts of bisphenol A epoxy resin with an epoxy value of 0.42eq / 100g, 10 parts of diethylenetriamine, 4 parts of modified phytic acid, 7.2 parts of nano-Al2O3, 1 part of polydimethylsiloxane, and 10 parts of acetone.

[0084] The specific method for preparing the metal anticorrosion coating of modified phytic acid doped nano-Al2O3 is as follows:

[0085] (1) Preparation of modified phytic acid:

[0086] S1, 0.5g phytic acid and 5.5g propylene glycol methyl ether were mixed, and stirred at a speed of 600r / min for 30min to ensure that the phytic acid was completely and evenly dispersed in the propylene glycol methyl ether to obtain a phytic acid mixed solution;

[0087] S2, 10.25g of ethylene glycol diglycidol was mixed evenly with the phytic acid in S1, and stirring was continued at a speed of 400r / min for 20min;

[0088] S3, finally adding 0.2 g of tetrabutylammonium bromide as a catalyst, reacting at 90° C. for 1 h, and finally obtaining modified phytic acid;

[0089] (2) Preparation of metal anticorrosion coatings doped with modified phytic acid and nano-Al2O3:

[0090] S1, weighing 80 parts of bisphenol A epoxy resin with an epoxy value of 0.42 eq / 100 g and 10 parts of acetone, and mixing them until uniform; then adding 4 parts of modified phytic acid, and continuing to stir;

[0091] S2. Finally, add the required curing agent diethylenetriamine 10 parts, leveling agent polydimethylsiloxane 1 part and 7.2 parts of nano-Al2O3 in sequence, and ensure that all ingredients are fully mixed with the assistance of ultrasound to make the nano-Al2O3 evenly dispersed in the coating system, and finally obtain the metal anti-corrosion coating doped with modified phytic acid nano-Al2O3.

[0092] Comparative Example 1

[0093] The anti-corrosion coating was prepared by referring to the formula and method of Example 3, except that the addition of modified phytic acid and nano-Al2O3 was omitted.

[0094] Comparative Example 2

[0095] The anticorrosive coating was prepared by referring to the formula and method of Example 3, except that the phytic acid was not modified.

[0096] Comparative Example 3

[0097] The anti-corrosion coating was prepared by referring to the formula and method of Example 3, the only difference being that nano-Al2O3 was replaced by nano-silicon dioxide.

[0098] Comparative Example 4

[0099] This comparative example provides a metal anticorrosion coating doped with modified phytic acid and nano-Al2O3, which includes the following components by weight: 80 parts of bisphenol A epoxy resin with an epoxy value of 0.42eq / 100g, 3 parts of diethylenetriamine, 4 parts of modified phytic acid, 4 parts of nano-Al2O3, 0.8 parts of polydimethylsiloxane, and 25 parts of acetone. The preparation method is consistent with Example 3.

[0100] The metal substrate is cleaned and dried, and the cleaned metal substrate is polished with sandpaper. After polishing, it is cleaned and dried again to remove the tiny particles that may be generated during the polishing process to ensure the surface cleanliness, thereby obtaining a pretreated metal substrate; the coatings of the embodiment and the comparative example are uniformly coated on the pretreated metal substrate using an automatic coating machine, and two scraping operations are performed to ensure the uniformity and consistency of the coating, and the coated metal substrate is placed in an oven and cured at a temperature of 80°C. The mechanical properties of the metal anticorrosion coating are shown in Table 1. The anticorrosion properties of the metal anticorrosion coating are shown in Table 2.

[0101] Table 1 Mechanical properties of embodiments and comparative examples

[0102]

[0103] Table 2 Anticorrosion performance of metal anticorrosion coatings in Examples and Comparative Examples

[0104]

[0105] It can be seen from Tables 1 and 2 that compared with pure epoxy resin coating (Comparative Example 1), the modified phytic acid in the modified phytic acid doped nano-Al2O3 coating has a higher negative charge on its surface and can chelate with a variety of metal ions to form a dense monomolecular protective film, which can effectively delay the corrosion of metals. At the same time, the nano-particle effect of nano-Al2O3 particles can also provide excellent physical shielding effect. The corrosion current density I (A / cm 2 ) is reduced to 7.85×10 -8 A / cm 2 The corrosion potential E / V is -0.805V, showing the best anti-corrosion performance among all the examples and comparative examples. Adding modified phytic acid and nano-Al2O3 particles to the coating can not only improve the adhesion of the coating, but also fill some pores with the addition of nano-fillers. Figure 1 It can be seen that the coating surface is flat and the nano-alumina is evenly dispersed in the epoxy resin matrix. This uniformity indicates that the doping of nano-fillers helps to improve the microscopic defects of the matrix material. The addition of nano-fillers not only fills some pores, but also promotes the density of the coating through its high surface energy and active sites, thereby improving the overall performance of the coating and helping to promote the repair of the resin matrix when the coating is damaged. Figure 3 (a) It can be clearly seen that the coating scratches are deep and the coating is damaged. The coating is placed at 80°C for self-repair for 4 hours, and the repaired coating is observed under an optical microscope. Figure 3 (b) It can be seen that the scratches on the coating have become significantly lighter, and the scratches in some areas have disappeared, indicating that the coating has a certain self-healing ability. In summary, the obtained anti-corrosion coating has good mechanical properties, self-healing properties and anti-corrosion properties.

[0106] The embodiments provided above are not intended to limit the scope of the present invention, and the steps described are not intended to limit the execution order thereof. Those skilled in the art may make obvious improvements to the present invention in combination with existing common knowledge, which also fall within the scope of protection defined by the claims of the present invention.

Claims

1. A metal anticorrosion coating doped with modified phytic acid and nano-Al2O3, characterized in that: The composition comprises the following components by weight: 75-85 parts of epoxy resin, 8-12 parts of curing agent, 3-6 parts of modified phytic acid, 0.8-9 parts of nano-Al2O3, 0.5-2 parts of leveling agent and 5-30 parts of solvent.

2. The metal anticorrosion coating of modified phytic acid doped with nano-Al2O3 according to claim 1, characterized in that: The composition comprises the following components by weight: 75-85 parts of epoxy resin, 8-12 parts of curing agent, 3-5 parts of modified phytic acid, 0.8-7.2 parts of nano-Al2O3, 0.5-2 parts of leveling agent and 5-20 parts of solvent.

3. The metal anticorrosion coating of modified phytic acid doped with nano-Al2O3 according to claim 1, characterized in that: The epoxy resin is bisphenol A type epoxy resin.

4. The metal anticorrosion coating of modified phytic acid doped with nano-Al2O3 according to claim 1, characterized in that: The epoxy value of the epoxy resin is one or more of 0.42 eq / 100 g, 0.44 eq / 100 g, and 0.51 eq / 100 g.

5. The metal anticorrosion coating of modified phytic acid doped with nano-Al2O3 according to claim 1, characterized in that: The curing agent is diethylenetriamine.

6. The metal anticorrosion coating of modified phytic acid doped with nano-Al2O3 according to claim 1, characterized in that: The leveling agent is one or more of polydimethylsiloxane, polyether-modified polydimethylsiloxane, polymethylphenylsiloxane, and alkyl-modified organic siloxane.

7. The metal anticorrosion coating of modified phytic acid doped with nano-Al2O3 according to claim 1, characterized in that: The solvent is acetone.

8. The metal anticorrosion coating of modified phytic acid doped with nano-Al2O3 according to claim 1, characterized in that: The preparation method of the modified phytic acid comprises the following steps: S1, mixing 0.3-0.7 g of phytic acid and 4-7.5 g of propylene glycol methyl ether to obtain a phytic acid mixed solution; S2, 9-11.5 g of ethylene glycol diglycidol and the phytic acid mixture of S1 are mixed and stirred evenly, and finally 0.1-0.35 g of tetrabutylammonium bromide is added as a catalyst, and the mixture is reacted at 85-95° C. for 1-1.5 h to finally obtain modified phytic acid.

9. The method for preparing the metal anticorrosion coating doped with modified phytic acid nano-Al2O3 according to claim 1, characterized in that: The method specifically comprises the following steps: by weight, 75 to 85 parts of epoxy resin and 5 to 30 parts of solvent are uniformly mixed, and then 3 to 6 parts of modified phytic acid are added, and then 8 to 12 parts of curing agent, 0.5 to 2 parts of leveling agent, and 0.8 to 9 parts of nano-Al2O3 are added, and ultrasonic treatment is performed to finally obtain a metal anti-corrosion coating doped with modified phytic acid and nano-Al2O3.

10. Use of the metal anticorrosion coating of modified phytic acid doped with nano-Al2O3 according to any one of claims 1 to 8 in the field of metal anticorrosion.

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