Preparation process of corrosion-resistant water-based passivated zinc-rich coating

Abstract

The invention belongs to the field of preparation processes of zinc-rich coatings, and relates to a preparation process of a corrosion-resistant water-based passivated zinc-rich coating, which comprises the following steps: obtaining spherical zinc powder; carrying out ball milling treatment; performing kneading treatment; and high polymer coating. The process provided by the invention can meet the requirements of the market on high-performance, environment-friendly and low-cost anticorrosive paint.

Description

Technical Field

[0001] The invention belongs to the field of zinc-rich coating preparation technology, and relates to a preparation technology of corrosion-resistant water-based passivated zinc-rich coating. Background Art

[0002] With the rapid development of science and technology and modern industry, the application areas of flake zinc powder are constantly expanding, and its importance in many fields such as anti-corrosion coatings is becoming increasingly prominent. In order to meet the urgent market demand for high-performance anti-corrosion coatings, the quality requirements for flake zinc powder are also constantly improving.

[0003] Flake zinc powder offers significant performance advantages over traditional spherical zinc powder. Its surface area is significantly larger than that of spherical zinc powder. Using the same spraying method, flake zinc powder requires significantly less paint than spherical zinc powder of the same type, significantly reducing coating costs. However, compatibility issues with organic coatings have been a key factor hindering further performance improvements. With the pursuit of high-performance coatings and increasingly stringent environmental requirements, the development of flake zinc powder with specialized properties has become increasingly urgent.

[0004] The development of zinc dust corrosion inhibitors and zinc dust passivation processes not only meets the demand for high-performance anti-corrosion coatings in numerous industrial sectors, such as municipal infrastructure construction, power generation, bridges, and offshore oil engineering, but also effectively reduces the significant damage caused by corrosion during the service life of steel structures, offering extremely broad application prospects. Therefore, independent research on zinc dust corrosion inhibitors and zinc dust passivation processes is extremely important for promoting the development of my country's anti-corrosion metal coatings industry and improving the market competitiveness of products.

[0005] Waterborne passivated epoxy zinc powder is a flaky zinc powder that has undergone a surface passivation treatment. It retains the excellent corrosion resistance of the original epoxy zinc-rich coating while leveraging the protective properties of the metal passivation layer during electrolysis, exhibiting numerous superior properties. Its characteristics include excellent corrosion resistance, high adhesion, high precision in blending, outstanding weather resistance, and self-healing capabilities. The unique structure of flaky zinc powder gives it a denser structure than spherical zinc powder, and surface zinc corrosion products provide an effective shielding effect for the coating. Furthermore, the stacked layers of flaky zinc powder provide superior hiding power compared to spherical zinc powder. The stacked arrangement of flaky powders prevents external corrosive agents from corroding the sample by penetrating layer by layer. Numerous microdomains are formed within the coating, reducing the coating's thermal expansion coefficient and curing shrinkage. This ensures adhesion between the metal powders and between the coating and the substrate, enhances coating density, and ultimately improves the coating's corrosion resistance. Furthermore, during the coating corrosion process, various corrosion products, such as zinc hydroxide, zinc oxide, and basic zinc carbonate, are formed on the zinc powder surface. The formation of these corrosion products can fill the pores within the coating, further preventing the intrusion of corrosive media such as oxygen and water, thereby increasing the coating resistance, reducing the electrochemical corrosion rate, and improving the corrosion resistance of the coating. The passivated zinc powder itself has a dense protective film. Due to the characteristics of the protective film, the corrosion resistance of the zinc powder is significantly improved. However, the surface potential and surface morphology of the passivated zinc powder are different from those of the unpassivated zinc powder, which reduces the coating ability of the outer cyclosiloxane.

[0006] Water-based passivated epoxy zinc powder can be widely used in many industrial fields such as municipal infrastructure construction, electricity, bridges, and offshore oil engineering, opening up a broad path for the application and expansion of epoxy zinc-rich coatings. However, there are still some urgent problems to be solved: although water-based zinc-rich coatings with good corrosion resistance have been developed abroad, their high price in my country limits their widespread application in the domestic market; while passivated zinc-rich coatings have better corrosion resistance than unpassivated coatings, the production process introduces heavy metal elements and generates wastewater and waste residue, which does not meet environmental protection requirements. Summary of the Invention

[0007] In response to the above problems, the present application provides a preparation process of corrosion-resistant water-based passivated zinc powder to meet the market demand for high-performance, environmentally friendly, and low-cost anti-corrosion coatings.

[0008] To achieve the above technical objectives, the technical solution adopted in this application is a preparation process of corrosion-resistant water-based passivated zinc powder, comprising the following steps:

[0009] 1) obtaining spherical zinc powder;

[0010] 2) Ball milling:

[0011] Adding 1.5-2.5 times the mass of spherical zinc powder, 1.5-2.5 times the mass of spherical zinc powder, 3-5% of the mass of OP-10, 0.5-1.5% of the mass of spherical zinc powder, and 1.5-3% of the mass of phosphomolybdic acid to spherical zinc powder, and stirring and mixing to form zinc powder slurry;

[0012] Put the zinc powder slurry into the ball mill; introduce nitrogen to exhaust the original air in the ball mill, start the ball mill to grind the spherical zinc powder into flake zinc powder;

[0013] 3) Kneading treatment: Add the flaky zinc powder into a kneader, set the speed to 1000r / min-1500r / min, knead with 10%-18% of the weight of the flaky zinc powder as a phosphate passivator and 8%-12% of the weight of the flaky zinc powder as BYK-192, maintain the stirring temperature at 40-50°C, and knead for 1-1.5 hours; after kneading, keep the temperature for 1 hour, and then wait for the kneader to cool to room temperature to obtain the passivated zinc powder;

[0014] 4) Polymer coating: Passivated zinc powder is added with 10%-15% of OP-10 by weight of the passivated zinc powder, 40%-50% of polyethylene glycol-200 by weight of the passivated zinc powder, and 250%-300% of 2% and 4% silane hydrolyzates by weight of the passivated zinc powder, and the mixture is mixed and stirred to allow the siloxane to combine with the surface carboxyl groups to form an organic coating group to obtain a zinc-rich stock slurry; the obtained zinc-rich stock slurry is placed in an oven, and the coating is dried to obtain a water-based passivated zinc powder raw material; wherein the amount ratio of the 2% silane hydrolyzate to the 4% silane hydrolyzate in the 2% and 4% silane hydrolyzates is (2-4):(4-5).

[0015] As an improved technical solution of the present application, when a ball mill is used to process zinc powder slurry, stainless steel balls and tungsten carbide balls are used for grinding.

[0016] As an improved technical solution of the present application, during the ball milling process, the ratio of stainless steel balls to tungsten carbide steel balls is 5:1; the ratio of the total mass of tungsten carbide steel balls and stainless steel balls to zinc powder is (30-40):1.

[0017] As an improved technical solution of the present application, the reaction conditions during the ball milling process are as follows: after nitrogen is filled into the ball mill to expel the air, the ball mill is started after setting to 40r / min to start ball milling. After the zinc powder is ground to 2-3 times the target particle size, the speed is reduced to 15r / min, and the machine is stopped after reaching the target particle size. The machine is kept warm at 40-60°C for 1-2h, and after the zinc powder in the machine reacts completely and cools to room temperature, the material is taken out and filtered to obtain flaky zinc powder.

[0018] As an improved technical solution of the present application, the kneading process also includes: keeping warm for 1 hour after the kneading is completed, adding 3%-7% of the mass of the phosphate passivator of the flaky zinc powder and continuing to knead for 1-1.5 hours until the mixture is evenly mixed; keeping warm for 2 hours and waiting for the temperature in the kneader to drop to room temperature to obtain the passivated zinc powder.

[0019] As an improved technical solution of the present application, during the polymer coating process, the oven temperature is set between 60-120°C and the time is within 5-15 minutes.

[0020] Beneficial effects

[0021] The technical solution of the present application uses a ball milling passivation process to produce a water-based passivated zinc-rich coating with high performance, corrosion resistance, and easy detection of coating damage; the ball milling process is used to obtain flaky zinc powder, and then an appropriate amount of grinding aid and passivator are added to obtain the passivated zinc powder; it has an excellent lamellar structure and is easy to form a dense passivation film. On the basis of the protection of the passivation film, a large number of surface anions are introduced on the surface of the zinc powder to increase the surface potential of the flaky zinc powder, and then cyclosiloxane is introduced to coat the surface of the zinc powder, so that the corroded material can once again form a dense coating with other metal ions in the environment to protect the uncorroded material; this product has the corrosion resistance and coating ability of highly enriched zinc powder, and also has the protective ability of the metal passivation layer on the metal.

[0022] The most environmentally friendly feature of this process is that the solvent is water-based starting from the ball milling stage, and no oil-based solvent is used; water-based solvents have little harm to the environment and are more environmentally friendly than traditional zinc powder coatings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Process flow chart of this application.

[0024] Figure 2 Scanning electron micrograph of water-based passivated zinc powder coating.

[0025] Figure 3 Lamellar structure of water-based passivated zinc powder. DETAILED DESCRIPTION

[0026] like Figure 1 、 Figure 3 As shown, a preparation process of corrosion-resistant water-based passivated zinc powder includes: ball milling treatment, kneading treatment and polymer coating treatment.

[0027] 1. Ball milling treatment:

[0028] Adding 1.5-2.5 times the mass of diethylene glycol butyl ether to the spherical zinc powder, adding 3-5% of OP-10 by mass of the spherical zinc powder, 0.5-1.5% of oleic acid by mass of the spherical zinc powder, and 1.5-3% of sodium phosphomolybdate by mass of the spherical zinc powder, and stirring and mixing to form a zinc powder slurry;

[0029] Put the zinc powder slurry into a clean and well-sealed ball mill;

[0030] After nitrogen is introduced into the ball mill to expel the air, the mill is set to 40 rpm and then started to mill. When the zinc powder has been ground to 2-3 times the target particle size, the speed is reduced to 15 rpm. Once the zinc powder in the ball mill reaches the target particle size, the mill is stopped. The mill is kept at 40-60°C for 1-2 hours. Once the zinc powder has reacted completely, the mill cools to room temperature and then filters the material to obtain zinc flakes. Failure to reduce the speed will result in uneven surfaces, where the passivation agent will have a greater effect. This uneven surface will result, creating an uneven passivation film and hindering effective coating. This step ensures the zinc powder is in a uniform state during ball milling, preventing it from breaking and maintaining a high specific surface area, which helps improve the quality of the zinc flakes. This step is crucial for converting spherical zinc powder into flakes. The introduction of protective gas prevents oxidation of the zinc powder within the ball mill. During the ball milling process, stainless steel balls and tungsten carbide balls are used for grinding; the mass ratio of stainless steel balls to tungsten carbide balls is 5:1; the ratio of the total mass of steel balls (the total mass of stainless steel balls and tungsten carbide balls) to zinc powder is 30-40:1.

[0031] The ball milling process is the core step of zinc powder deformation. This process uses the method of introducing inert gas to reduce the possibility of zinc powder oxidation, and then adds phosphomolybdate to make the solution acidic. The molybdenum in phosphomolybdic acid is in a high valence state. The high valence molybdenum ion has a strong oxidizing property, which reduces the surface activity of zinc powder; (Zn+H3PMo12O40→Zn 2+ +Mo 5+ +H + +H2O) slightly dissolves the surface of zinc powder to form a slightly rough surface structure, and the molybdate and phosphate generated when molybdenum phosphate decomposes reacts with zinc ions to produce a dense surface film attached to the surface of zinc powder (Zn 2+ +PO4 3- +MoO4 2- →Zn3(PQ4)2·ZnMoO4). This metallic passivation film adsorbed on the zinc powder surface increases the zinc's surface electron density, hindering anodic dissolution. Molybdate ions adsorbed on the surface are incorporated into the intergranular spaces of the surface layer, reducing its surface activity. Combined with the mechanical force of the ball mill, the originally spherical zinc powder is transformed into flakes. During spraying, the zinc powder is stacked layer by layer. Once a certain thickness is accumulated, uneven contact with the outside world creates varying degrees of corrosion, forming a phase boundary film. This further collapses to form a stable film, effectively preventing the zinc powder from isolating from the medium and thus extending its service life.

[0032] 2. Kneading treatment

[0033] ① Add flaky zinc powder to a kneader with good sealing performance, set the speed to 1000r / min-1500r / min, add 10%-18% of Lubrizol 2062H (phosphate passivator) by weight of the flaky zinc powder and 8%-12% of BYK-192 by weight of the flaky zinc powder, and knead to modify the zinc powder. Maintain the stirring temperature at 40-50°C and knead for 1-1.5 hours.

[0034] ② After kneading, heat for 1 hour. Slowly dropwise spray an effective amount of flaky zinc powder (3%-7% Lubrizol 2062H and AD015 in a ratio of 10:1) into the kneader and continue kneading for 1-1.5 hours until the mixture is uniform. Phosphate passivator: Lubrizol 2062H and AD015.

[0035] ③ Keep the zinc powder slurry after corrosion inhibition warm for 2 hours until the zinc powder is fully passivated.

[0036] ④ After waiting for the temperature inside the kneading machine to drop to room temperature, open the kneading machine to discharge the material to obtain passivated zinc powder.

[0037] During the kneading process, a phosphate passivating agent is added and a protective gas is introduced to passivate the initially obtained flaky zinc powder, forming a passivation film on the surface of the flaky zinc powder to reduce the contact between the zinc powder and the medium.

[0038] 3. Polymer coating

[0039] ① Take passivated zinc powder, add OP-10 at 10%-15% by weight of the passivated zinc powder, add polyethylene glycol-200 at 40%-50% by weight of the passivated zinc powder, and add 250%-300% by weight of 2% and 4% silane content hydrolyzates. The ratio of the 2% silane content hydrolyzate to the 4% silane content hydrolyzate is (2-4):(4-5), preferably 3:5.

[0040] ② Preparation of siloxane hydrolyzate: Silane hydrolyzate with a KH-560 content of 2% and 4% was prepared respectively. The 2% silane hydrolyzate refers to adding 2g of KH-560 to a mixture of 98g of ethanol and distilled water in a ratio of 1:1; the 4% silane hydrolyzate refers to adding 4g of KH-560 to a mixture of 96g of ethanol and distilled water in a ratio of 1:1.

[0041] ③ The 2% and 4% silane hydrolyzates obtained in step ② are slowly added dropwise to the passivated zinc powder, stirred in a water bath, and mixed to allow the siloxane to combine with the surface carboxyl groups to form organic coating groups to obtain zinc-rich slurry.

[0042] ④ Place the obtained zinc-rich slurry into an oven, set the temperature between 60-120° C., and dry the coating within 5-15 minutes to obtain a water-based passivated zinc powder raw material.

[0043] The coating process uses the sol-gel method to hydrolyze and bond zinc powder and KH-560 in ethanol at pH = 4 to form alkoxy groups. The sol particles collide through geometric Brownian motion (GBM) and undergo Ostwald ripening to form a colloid with a uniform surface or stacking structure. The colloid undergoes heteronuclear condensation to form Si-O-Zn (Si-O+Zn 2+ →Si-O-Zn) simultaneously undergoes cross-linking to form a three-dimensional network structure that wraps the zinc powder in the middle. The three-dimensional network structure forms a ring-shaped organic layer on the outer layer of the zinc powder particles, which can effectively reduce the corrosion caused by direct contact between the zinc powder and the outside world.

[0044] During the sol stage, hydroxyl (-COOH) or amino (-NH2) groups are introduced to the surface through dynamic hydrogen bonds or the coordination of zinc ions to form a reversible cross-linked network, thereby forming a repairable organic coating layer.

[0045] KH-560: It is mainly used to add fine colloidal particles into the solution system during gelation. It has both organic and inorganic reaction activity and can react with sodium ions (Na) under the conditions of layered spraying of flaky zinc powder. 2+ ) and dielectric metal ions (R n+ ) combined with (Si-OH+R n+ →Si-OR) forms a similar polygonal structure. After adding polyethylene glycol-200, the silanol chemically crosslinks to form a network structure film, which is stacked on the outer layer of the next zinc powder layer to isolate the medium.

[0046] OP-10 Dispersant: Because flaky zinc powder is prone to segregation and self-aggregation in solution, it is difficult to fully disperse it with mechanical stirring alone. Therefore, to prevent this polymerization reaction, a dispersant is used to form a shell layer on the outer layer of the zinc powder, thereby increasing the distance between the two flaky zinc powder particles and maintaining the stability of the coating. At the same time, during the dispersion process of the coating, the dispersant can adhere to the surface of the flaky zinc powder, affecting the van der Waals and electrostatic forces between the particles, changing the spatial phase of the particles to prevent segregation, and preventing the agglomeration or aggregation of pigment particles when shear force is eliminated.

[0047] Example 1

[0048] 1. Ball milling

[0049] 17 kg of diethylene glycol butyl ether was added to 7 kg of spherical zinc powder, stirred, and then 210 g of OP-10, 35 g of sodium oleate phosphomolybdate, and 105 g of sodium molybdate were added and stirred thoroughly to form a zinc powder slurry. The slurry was then placed in a clean, well-sealed ball mill. The spherical zinc powder was ball-milled and mechanically ground into flaky zinc powder during the milling process. After nitrogen was introduced into the ball mill to expel the air, the mill was set to 40 rpm and started to mill. After the zinc powder was ground to 2.5 times the target particle size, the mill was switched to 15 rpm. After reaching the target particle size, the mill was stopped and maintained at 50°C for 1.5 hours. After the zinc powder reacted completely and cooled to room temperature, the material was removed and filtered to obtain flaky zinc powder.

[0050] The ratio of stainless steel balls to tungsten carbide steel balls is 5:1; the ratio of the total mass of stainless steel balls and tungsten carbide steel balls to zinc powder is 40:1.

[0051] 2. Kneading treatment

[0052] Take 400g of effective flaky zinc powder and add it to a well-sealed kneader, set the speed to 1500r / min, add 60g of phosphate passivator Lubrizol-2062H and 40g BYK-192, and knead to modify the zinc powder. Maintain the stirring temperature at 40-50°C and knead for 1-1.5h.

[0053] After kneading, keep warm for 1 hour, add 28g of phosphate and continue kneading for 1-1.5 hours. During the kneading process, slowly add dropwise into the kneader until the mixture is evenly mixed.

[0054] Keep the inhibited zinc powder slurry warm for 2 hours until the zinc powder is fully passivated;

[0055] After the temperature in the kneader drops to room temperature, the kneader is opened to discharge the material to obtain passivated zinc powder.

[0056] 3. Polymer coating

[0057] Take 4g of passivated zinc powder, 0.45g of OP-10, 1.75g of polyethylene glycol-200, and 10.25g of 2% and 4% silane content hydrolyzates, mix and stir to allow silanols to combine with surface carboxyl groups to form organic coating groups;

[0058] The zinc powder slurry obtained after kneading is placed in an oven, the temperature is set between 60-120° C., and the time is within 5-15 minutes, and the coating is dried to obtain a water-based passivated zinc powder raw material.

[0059] Test sample preparation process:

[0060] Add 4g of a 1:1 mixture of ethyl acetate and butyl acetate to 2g of zinc powder, mix with the baking paint resin, and perform relevant tests on the performance of the water-based passivated zinc powder as needed.

[0061] Test sample preparation

[0062] Preparation of water-based passivated zinc powder coating:

[0063] Component A: A metal slurry composed of a 1:1 mixture of micron-sized flaky zinc powder and a high-boiling-point organic solvent, butyl ester; Component B: HY-560, a hydrolyzed silane coupling agent; and Component C: an acrylic resin (Guangdong Hongke), a base material for the passivation solution. Defoamers, thickeners, and other additives are also added during the coating preparation process.

[0064] Components A, B, and C were mixed in a mass ratio of 1:2:15 to preliminarily obtain a water-based passivated zinc-rich coating, and then the coating viscosity was adjusted to 40 Pa.s using hydroxyethyl cellulose.

[0065] The tinplate that has been polished and alkaline washed to have no pollution and oxide layer on the surface is used as the spraying substrate, sprayed with the prepared water-based passivation zinc-rich coating, and dried for subsequent testing.

[0066] Control group:

[0067] The zinc-based galvanized surface coating spray paint purchased from the market was sprayed on the prepared tinplate in the same preparation method as the control group.

[0068] Compared with the traditional silane coupling agent treatment method, this process has two advantages: 1) the dual ligands work synergistically to form a denser monolayer (coverage >84% vs. 78% for the traditional method); and 2) the use of hydroxyethyl cellulose to adjust the coating viscosity to ensure stress adaptive regulation during the curing process.

[0069] Detection method:

[0070] 1. Corrosion resistance test: The quality of corrosion resistance is an important indicator to detect whether the sample is superior to previous coatings. Two test methods are prepared to simulate the common environment of zinc powder to detect the corrosion resistance of water-based passivated zinc powder.

[0071] 1.1. Electrochemical test:

[0072] This test uses an electrochemical workstation to test the polarization curve: the three-electrode auxiliary electrode is graphite, the reference electrode is a saturated calomel electrode, the coating is the working electrode, and the experimental solution is a weak acid solution. The two substrates sprayed with zinc powder are placed in the original cell to compare and observe the corrosion resistance of water-based passivated zinc powder and ordinary zinc powder.

[0073] 1.2. Neutral salt spray test experiment:

[0074] The salt spray test was conducted according to the method of GB / T 10125-2012 "Artificial atmosphere corrosion test salt spray test". Two substrates sprayed with different zinc powder coatings were placed in the test chamber for testing. After the experiment, the corrosion degree and quality changes of the two boards were compared.

[0075] 2. Surface morphology and structure analysis: To test whether the zinc powder is passivated and coated with polymer, the surface morphology of the prepared coating needs to be observed using a SU1000 scanning electron microscope, and then the coating element content of the coating and the crystal surface morphology are analyzed using an MSP-2S ion diffractometer.

[0076] Figure 2 The scanning electron microscope image of the water-based passivated zinc powder coating shows a large number of spheres on the surface, indicating a high degree of coating and good coating ability.

[0077] 3. Adhesion: To test the adhesion of the sample, first prepare the sprayed substrate, cross-scribe the substrate into a grid with a knife, then cut a piece of tape about 75mm long with a specific tape and flatten it on top of the grid. Then quickly tear off the tape at a 60° angle. Observe the cut area of the coating with a magnifying glass, and judge the adhesion based on the peeling of the coating within the cut area grid.

[0078] 4. Thermal Analysis: 3g of the prepared waterborne passivated zinc-rich coating was subjected to a thermogravimetric analysis. Nitrogen was introduced to ensure safety during the experiment. Thermogravimetric analysis was used to measure the mass change of the waterborne passivated epoxy zinc powder over temperature and time. The oxidation, volatilization, crystal water removal, phase change, and reaction heat of the waterborne passivated epoxy zinc powder were then measured in combination with differential thermal analysis. The same test was also performed on the same type of epoxy zinc powder for comparison.

[0079] 5. Impact resistance test: Fix the metal plate to be tested on the test bench and slowly raise the test hammer to a height of 45cm. Let the hammer fall freely and observe the paint peeling of the hit part.

[0080] 6. Stability test: Seal the prepared paint and place it naturally to observe the appearance of the paint and the change of viscosity over time. Observe whether there is bubbling or agglomeration. If there is no such phenomenon, the stability is good.

[0081] Test results:

[0082]

[0083]

Claims

1. A process for preparing corrosion-resistant water-based passivated zinc powder, characterized in that: Includes the following steps 1) obtaining spherical zinc powder; 2) Ball milling: Adding 1.5-2.5 times the mass of spherical zinc powder, 1.5-2.5 times the mass of spherical zinc powder, 3-5% of the mass of OP-10, 0.5-1.5% of the mass of spherical zinc powder, and 1.5-3% of the mass of phosphomolybdic acid to spherical zinc powder, and stirring and mixing to form zinc powder slurry; Put the zinc powder slurry into the ball mill; introduce nitrogen to exhaust the original air in the ball mill, start the ball mill to grind the spherical zinc powder into flake zinc powder; 3) Kneading treatment: Add the flaky zinc powder into a kneader, set the speed to 1000r / min-1500r / min, knead with 10%-18% of the mass of the flaky zinc powder as a phosphate passivator and 8%-12% of the mass of the flaky zinc powder as BYK-192, maintain the stirring temperature at 40-50°C, and knead for 1-1.5 hours; after kneading, keep the temperature for 1 hour, and then wait for the kneader to reach room temperature to obtain the passivated zinc powder; 4) Polymer coating: Passivated zinc powder is taken, OP-10 in an amount of 1% to 1.5% by mass of the passivated zinc powder is added, polyethylene glycol-200 in an amount of 30% to 50% by mass of the passivated zinc powder is added, and hydrolyzates with 2% and 4% silane contents in an amount of 250% to 300% by mass of the passivated zinc powder are added, and the mixture is mixed and stirred to allow siloxane to combine with surface carboxyl groups to form organic coating groups to obtain a zinc-rich stock slurry; the obtained zinc-rich stock slurry is placed in an oven, and the coating is dried to obtain a water-based passivated zinc powder raw material; wherein the amount ratio of the hydrolyzate with 2% silane content to the hydrolyzate with 4% silane content in the hydrolyzate with 2% silane content is (2-4):(4-5).

2. A process for preparing corrosion-resistant water-based passivated zinc powder according to claim 1, characterized in that, When using a ball mill to process zinc powder slurry, stainless steel balls and tungsten carbide balls are used for grinding.

3. A preparation process for corrosion-resistant water-based passivated zinc powder according to claim 2, characterized in that, During the ball milling process, the ratio of stainless steel balls to tungsten carbide steel balls was 5:1; the ratio of the total mass of tungsten carbide steel balls and stainless steel balls to zinc powder was (30-40):

1.

4. A process for preparing corrosion-resistant water-based passivated zinc powder according to claim 1, characterized in that: The reaction conditions during the ball milling process are as follows: after nitrogen is filled into the ball mill to expel the air, the ball mill is started at 40 r / min and ball milling is started. After the zinc powder is ground to 2-3 times the target particle size, the speed is reduced to 15 r / min. After reaching the target particle size, the machine is stopped and kept at 40-60°C for 1-2 hours. After the zinc powder in the machine reacts completely and cools to room temperature, the material is taken out and filtered to obtain flaky zinc powder.

5. A process for preparing corrosion-resistant water-based passivated zinc powder according to claim 1, characterized in that: The kneading process also includes: keeping warm for 1 hour after kneading, adding 3%-7% of the phosphate passivator of the flaky zinc powder by weight and continuing kneading for 1-1.5 hours until the mixture is evenly mixed; keeping warm for 2 hours and waiting for the temperature in the kneader to drop to room temperature to obtain the passivated zinc powder.

6. A process for preparing corrosion-resistant water-based passivated zinc powder according to claim 1, characterized in that: During the polymer coating process, the oven temperature is set between 60-120°C and the time is within 5-15 minutes.

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