Inorganic water-based anticorrosive paint and preparation method thereof

Abstract

The invention discloses an inorganic water-based anticorrosive coating and a preparation method thereof, and particularly relates to the technical field of metal protection. The inorganic water-based anticorrosive paint is prepared from a composite base material, a magnesium aluminum phosphate mixture, modified metakaolin, zinc powder, a strontium molybdate antirust pigment, an inorganic dispersant, a silicon dioxide thixotropic agent and a silicon dioxide defoaming agent. A multiple synergistic protection system based on silica sol, phosphate and active filler is constructed, a compact silicon-aluminum-phosphorus-oxygen three-dimensional interpenetrating network is formed through room-temperature acid-base trigger reaction, and due to the fact that the chemical property of the network is extremely stable, a stable conductive matrix can be provided for zinc powder and cooperates with molybdate to strengthen the passivation effect, and the passivation performance of the zinc powder is improved. And the overall corrosion resistance is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metal protection, more particularly, the present application relates to an inorganic water-based anticorrosive coating and a preparation method. BACKGROUND

[0002] With the deepening of the concept of global sustainable development, the paint industry is accelerating the transformation towards low volatile organic compounds, non-toxic and harmless water-based direction; in the field of metal corrosion protection, inorganic water-based paint is considered as a potential environmental protection alternative scheme due to its outstanding advantages of non-combustible, non-toxic, high temperature resistance, high hardness and super weather resistance; therefore, it is of great significance to develop a new type of inorganic water-based anticorrosive coating.

[0003] The anticorrosive coating in the related art includes high modulus potassium silicate solution, zinc powder, filler, additive and water; wherein the high modulus potassium silicate solution as the main film-forming material, the silica sol formed after hydrolysis can react with iron ions on the surface of the metal substrate to form iron silicate complex, and finally condense into a stable three-dimensional network structure, providing basic physical isolation and chemical passivation corrosion protection; zinc powder as a functional pigment, mainly through the electrochemical cathodic protection effect to prevent rust; the conventional filler is generally quartz powder and talc powder, mainly playing the role of filling volume, increasing the thickness of the coating and reducing the cost, but the shape and functional design are insufficient, and the contribution to improving the coating density and permeability is limited; the additive and water include dispersant and defoamer, which are used to ensure the basic process performance in the production and construction process.

[0004] However, when actually used, it still has some disadvantages, such as poor corrosion resistance, traditional formula relies on the passivation of silicate and the corrosion inhibition of single pigment, in harsh corrosion environment, once the protection network has defects, local corrosion will spread rapidly; poor adhesion, due to the characteristics of film-forming material and the non-optimized filler system, the coating formed by traditional coating often has large internal stress, resulting in poor adhesion, insufficient flexibility of paint film and easy cracking; poor water resistance, traditional method does not form a dense network during curing process, the coating is easy to whiten and bubble when encountering water in early stage, which not only affects the appearance, but also seriously damages its barrier protection function. SUMMARY

[0005] In order to improve the above problems and reduce the problems of poor corrosion resistance, poor adhesion and poor water resistance of the anticorrosive coating in the related art, the present application provides an inorganic water-based anticorrosive coating and a preparation method to solve the problems in the above background art.

[0006] To achieve the above purpose, the present application provides the following technical scheme: An inorganic water-based anticorrosive coating and a preparation method, comprising the following steps: S1, the composite binder is put into a high-speed dispersion kettle, the stirring speed is kept at 350-450 r / min, aluminum magnesium phosphate mixture, modified metakaolin, zinc powder, strontium molybdate anti-rust pigment and inorganic dispersant are added, then the stirring speed is increased to 1100-1300 r / min, and high-speed dispersion is carried out for 40-50 min, to obtain a preliminary dispersion slurry; S2, the preliminary dispersion slurry obtained in S1 is transferred to a sand mill, zirconia beads with a diameter of 0.6 mm are used as grinding media, and the slurry is ground to a fineness of not more than 20 um under the condition of circulating water cooling; then silica thixotropic agent and silica defoaming agent are added to the slurry, and stirring is carried out at a speed of 550-650 r / min for 18-22 min, followed by vacuum degassing at -0.09 MPa for 20 min, and filtering with a 300 mesh filter screen, to obtain an inorganic water-based anticorrosive coating.

[0007] Preferably, the preparation raw materials of the inorganic water-based anticorrosive coating each component and weight fraction are as follows: composite binder 100 parts, aluminum magnesium phosphate mixture 4-7.5 parts, modified metakaolin 12-20 parts, zinc powder 8-15 parts, strontium molybdate anti-rust pigment 2-4 parts, inorganic dispersant 0.3-0.7 parts, silica thixotropic agent 0.1-0.4 parts, and silica defoaming agent 0.1-0.3 parts.

[0008] Preferably, the preparation method of the aluminum magnesium phosphate mixture comprises the following steps: C1, the aluminum dihydrogen phosphate solution is put into a reaction kettle, magnesium oxide powder is added to the reaction kettle under the condition of a temperature lower than 40℃ and a stirring speed of 200 r / min; then the temperature is increased to 75-85℃, and constant temperature stirring is carried out under the same condition for 2.5-3.5 h, to obtain a viscous slurry; wherein the solid content of the aluminum dihydrogen phosphate solution is 50%; C2, the viscous slurry obtained in C1 is transferred to a spray drying tower, and spray drying is carried out under the condition of an inlet air temperature of 180℃, an outlet air temperature of 90℃, and an atomization pressure of 0.3 MPa, to obtain an aluminum magnesium phosphate mixture.

[0009] Preferably, the preparation raw materials of the aluminum magnesium phosphate mixture each component and weight fraction are as follows: aluminum dihydrogen phosphate 5.5-10 parts, magnesium oxide 1 part.

[0010] Preferably, the preparation method of the modified metakaolin comprises the following steps: B1, the metakaolin and sodium polyphosphate are mixed and placed in a muffle furnace, the temperature is increased to 320-380℃ at a heating rate of 3-8℃ / min, and after constant temperature calcination at this temperature for 2.5-4 h, natural cooling is carried out, to obtain a calcined product; B2. The calcined product obtained in B1 is put into a planetary ball mill and dry-ground at a speed of 350 r / min for 2 hours. After grinding, it is passed through a 150-mesh standard sieve to obtain modified metakaolin.

[0011] Preferably, the raw materials for preparing the modified metakaolin are as follows: 100 parts metakaolin and 8.33-12.5 parts sodium polyphosphate.

[0012] Preferably, the method for preparing the composite matrix includes the following steps: A1. Under nitrogen protection, potassium silicate, lithium silicate, and acidic silica sol are added sequentially to a high-speed dispersion reactor to obtain phase A; The modulus of potassium silicate is 3.3; The lithium-ion glass has a modulus of 2.0. The acidic silica sol has a pH of 2.5 and a solid content of 30%. A2. The A phase obtained in A1 is added dropwise to the reinforcing slurry through a constant pressure dropping funnel while stirring at a speed of 400-600 r / min, and the dropwise addition is continued for 20-40 min. After the dropwise addition is completed, the mixture is stirred under the same conditions for 50-70 min to obtain the composite matrix. The reinforcing slurry is composed of active silica sol and silica fume in a weight ratio of 1:1.

[0013] Preferably, the components and weight parts of the raw materials for preparing the composite matrix are as follows: 35-45 parts of potassium silicate, 15-25 parts of lithium silicate, 20-30 parts of acidic silica sol, and 10-20 parts of reinforcing slurry.

[0014] Preferably, the inorganic dispersant is composed of sodium hexametaphosphate and sodium tripolyphosphate in a weight ratio of 1:1; The silica thixotropic agent is a hydrophobically modified fumed silica thixotropic agent; The silica defoamer is a hydrophobically modified silica defoaming powder.

[0015] 1. This invention constructs a multi-synergistic protection system based on silica sol, phosphate and active filler. It utilizes room temperature acid-base triggered reaction to form a dense three-dimensional interpenetrating network of silicon, aluminum, phosphorus and oxygen. Due to its extremely stable chemical properties, it can provide a stable conductive matrix for zinc powder and synergistically enhance the passivation effect of molybdate, thereby improving its overall corrosion resistance. 2. This invention introduces modified metakaolin with a surface deeply activated by phosphate and reinforcing slurry as coupling agents to form high-density chemical covalent bond connections between fillers and base materials, and between coatings and substrates, thereby constructing an inorganic composite coating with extremely high cohesive strength during room temperature curing and improving its adhesion. 3. By designing the acid-base balance and curing reaction path of the composite matrix, this invention ensures that the formed inorganic polymer network is highly cross-linked and structurally uniform, reducing microscopic defects and hydrophilic channels that can be penetrated and destroyed by water molecules. At the same time, the hydrophobic components in the system migrate to the coating surface and internal pores during the curing process, further enhancing the overall hydrophobicity. Detailed Implementation

[0016] The present invention will be further described in detail below with reference to the embodiments of the present invention. Unless otherwise specified below, the raw materials used in the various examples and embodiments of the present invention are all commercially available common materials. Preparation Examples 1-5 A mixture of aluminum magnesium phosphate, the components and their corresponding proportions of which are shown in the table below, is prepared by the following method: C1. Add aluminum dihydrogen phosphate solution to the reactor. Add magnesium oxide powder to the reactor at a temperature below 40°C and a stirring speed of 200 r / min. Then raise the temperature to 80°C and stir at the same temperature for 3 hours to obtain a viscous slurry. The solid content of the aluminum dihydrogen phosphate solution is 50%. C2. The viscous slurry obtained in C1 is transferred to a spray drying tower and spray dried under the conditions of inlet air temperature of 180℃, outlet air temperature of 90℃, and atomization pressure of 0.3MPa to obtain a mixture of aluminum magnesium phosphate.

[0017] Table: Components and their mass ratios (g) of the raw materials used in Preparation Examples 1-5 Preparation Example 6 A magnesium aluminum phosphate mixture, differing from Preparation Example 1 in that its preparation method is as follows: C1. Add aluminum dihydrogen phosphate solution to the reactor. Add magnesium oxide powder to the reactor at a temperature below 40°C and a stirring speed of 200 r / min. Then raise the temperature to 75°C and stir at the same temperature for 2.5 h to obtain a viscous slurry. C2. The viscous slurry obtained in C1 is transferred to a spray drying tower and spray dried under the conditions of inlet air temperature of 180℃, outlet air temperature of 90℃, and atomization pressure of 0.3MPa to obtain a mixture of aluminum magnesium phosphate.

[0018] Preparation Example 7 A magnesium aluminum phosphate mixture, differing from Preparation Example 1 in that its preparation method is as follows: C1. Add aluminum dihydrogen phosphate solution to the reactor. Add magnesium oxide powder to the reactor at a temperature below 40°C and a stirring speed of 200 r / min. Then raise the temperature to 85°C and stir at the same temperature for 3.5 h to obtain a viscous slurry. C2. The viscous slurry obtained in C1 is transferred to a spray drying tower and spray dried under the conditions of inlet air temperature of 180℃, outlet air temperature of 90℃, and atomization pressure of 0.3MPa to obtain a mixture of aluminum magnesium phosphate.

[0019] Preparation Examples 8-12 A modified metakaolin, the components and their corresponding proportions of which are shown in the table below, is prepared using the following method: B1. Mix metakaolin with sodium polyphosphate and place it in a muffle furnace. Heat the mixture to 350°C at a heating rate of 5°C / min, and calcine it at this temperature for 3 hours. Then, allow it to cool naturally to obtain the calcined product. B2. The calcined product obtained in B1 is put into a planetary ball mill and dry-ground at a speed of 350 r / min for 2 hours. After grinding, it is passed through a 150-mesh standard sieve to obtain modified metakaolin.

[0020] Table: Components and their mass ratios (g) of the raw materials used in Preparation Examples 8-12 Preparation Example 13 A modified metakaolinite, differing from preparation example 8, is prepared using the following method: B1. Mix metakaolin with sodium polyphosphate and place it in a muffle furnace. Heat the mixture to 320°C at a heating rate of 3°C / min and calcine it at this temperature for 2.5 hours. Then, allow it to cool naturally to obtain the calcined product. B2. The calcined product obtained in B1 is put into a planetary ball mill and dry-ground at a speed of 350 r / min for 2 hours. After grinding, it is passed through a 150-mesh standard sieve to obtain modified metakaolin.

[0021] Preparation Example 14 A modified metakaolinite, differing from preparation example 8, is prepared using the following method: B1. Mix metakaolin with sodium polyphosphate and place it in a muffle furnace. Heat the mixture to 380°C at a heating rate of 8°C / min, and calcine it at this temperature for 4 hours. Then, allow it to cool naturally to obtain the calcined product. B2. The calcined product obtained in B1 is put into a planetary ball mill and dry-ground at a speed of 350 r / min for 2 hours. After grinding, it is passed through a 150-mesh standard sieve to obtain modified metakaolin.

[0022] Preparation Examples 15-19 A composite matrix, the components of which and their corresponding proportions are shown in the table below, is prepared using the following method: A1. Under nitrogen protection, potassium silicate, lithium silicate, and acidic silica sol are added sequentially to a high-speed dispersion reactor to obtain phase A; The modulus of potassium silicate is 3.3; The lithium-ion glass has a modulus of 2.0. The acidic silica sol has a pH of 2.5 and a solid content of 30%. A2. The A phase obtained in A1 is added dropwise to the reinforcing slurry through a constant pressure dropping funnel while stirring at a speed of 500 r / min. The addition is continued for 30 min. After the addition is completed, the mixture is stirred under the same conditions for 60 min to obtain the composite matrix.

[0023] The reinforcing slurry is composed of active silica sol and silica fume in a weight ratio of 1:1. Table: Components and their mass ratios (g) of the raw materials used in Preparation Examples 15-19 Preparation Example 20 A composite matrix material, differing from preparation example 15, is prepared using the following method: A1. Under nitrogen protection, potassium silicate, lithium silicate, and acidic silica sol are added sequentially to a high-speed dispersion reactor to obtain phase A; A2. The A phase obtained in A1 is added dropwise through a constant pressure dropping funnel under stirring at a speed of 400 r / min to strengthen the slurry for 20 min. After the addition is completed, the mixture is stirred under the same conditions for 50 min to obtain the composite matrix.

[0024] Preparation Example 21 A composite matrix material, differing from preparation example 15, is prepared using the following method: A1. Under nitrogen protection, potassium silicate, lithium silicate, and acidic silica sol are added sequentially to a high-speed dispersion reactor to obtain phase A; A2. The A phase obtained in A1 is added dropwise to the reinforcing slurry through a constant pressure dropping funnel under stirring at a speed of 600 r / min for 40 min. After the addition is completed, the mixture is stirred under the same conditions for 70 min to obtain the composite matrix.

[0025] Preparation Examples 22-26 An inorganic water-based anticorrosive coating, the components and their corresponding proportions of which are shown in the table below, is prepared using the following method: S1. Add the composite base material into a high-speed dispersion kettle, and while maintaining a stirring speed of 400 r / min, add aluminum magnesium phosphate mixture, modified metakaolin, zinc powder, strontium molybdate anti-rust pigment and inorganic dispersant. Then increase the stirring speed to 1200 r / min and continue high-speed dispersion for 45 min to obtain a preliminary dispersion slurry. The inorganic dispersant is composed of sodium hexametaphosphate and sodium tripolyphosphate in a weight ratio of 1:1. The aluminum magnesium phosphate mixture was prepared in Preparation Example 1; The modified metakaolin was prepared by Preparation Example 8; The composite matrix was prepared in Preparation Example 15; S2. The preliminary dispersed slurry obtained in S1 is transferred to a sand mill. Zirconia beads with a diameter of 0.6 mm are used as the grinding medium. The slurry is ground under circulating water cooling conditions until the fineness of the slurry is no more than 20 μm. Then, silica thixotropic agent and silica defoamer are added to the slurry. The mixture is stirred at a speed of 600 r / min for 20 min. Then, it is degassed under vacuum at -0.09 MPa for 20 min and filtered through a 300-mesh filter to obtain an inorganic water-based anti-corrosion coating.

[0026] The silica thixotropic agent is a hydrophobically modified fumed silica thixotropic agent. The silica defoamer is a hydrophobically modified silica defoaming powder. Table: Components and their mass ratios (g) of the raw materials used in Preparation Examples 22-26 Preparation Example 27 An inorganic water-based anticorrosive coating differs from preparation example 22 in that its preparation method is as follows: S1. Add the composite base material into a high-speed dispersion kettle, and while maintaining a stirring speed of 350 r / min, add aluminum magnesium phosphate mixture, modified metakaolin, zinc powder, strontium molybdate anti-rust pigment and inorganic dispersant. Then increase the stirring speed to 1100 r / min and continue high-speed dispersion for 40 min to obtain a preliminary dispersion slurry. S2. The preliminary dispersed slurry obtained in S1 is transferred to a sand mill and ground with 0.6 mm diameter zirconia beads as the grinding medium under circulating water cooling conditions until the slurry fineness is no greater than 20 μm. Then, silica thixotropic agent and silica defoamer are added to the slurry and stirred at 550 r / min for 18 min. Then, it is vacuum degassed at -0.09 MPa for 20 min and filtered with a 300 mesh filter to obtain an inorganic water-based anti-corrosion coating.

[0027] Preparation Example 28 An inorganic water-based anticorrosive coating differs from preparation example 22 in that its preparation method is as follows: S1. Add the composite base material into a high-speed dispersion kettle, and while maintaining a stirring speed of 450 r / min, add aluminum magnesium phosphate mixture, modified metakaolin, zinc powder, strontium molybdate anti-rust pigment and inorganic dispersant. Then increase the stirring speed to 1300 r / min and continue high-speed dispersion for 50 min to obtain a preliminary dispersion slurry. S2. The preliminary dispersed slurry obtained in S1 is transferred to a sand mill. Zirconia beads with a diameter of 0.6 mm are used as the grinding medium. The slurry is ground under circulating water cooling conditions until the fineness of the slurry is no more than 20 μm. Then, silica thixotropic agent and silica defoamer are added to the slurry. The mixture is stirred at a speed of 650 r / min for 22 min. Then, it is vacuum degassed at -0.09 MPa for 20 min and filtered through a 300-mesh filter to obtain an inorganic water-based anti-corrosion coating.

[0028] Preparation Examples 29-34 An inorganic water-based anti-corrosion coating differs from Preparation Example 22 in that the use of the aluminum magnesium phosphate mixture in its components is different, and the specific correspondence is shown in the table below.

[0029] Table: Comparison of the usage of aluminum magnesium phosphate mixtures in Preparation Examples 29-34 Preparation Examples 35-40 An inorganic water-based anti-corrosion coating differs from Preparation Example 22 in that the modified metakaolin used in its components is different, and the specific correspondence is shown in the table below.

[0030] Table: Comparison of the use of modified metakaolin in preparation examples 35-40 Preparation Examples 41-46 An inorganic water-based anti-corrosion coating differs from Preparation Example 22 in that the composite base material used in its components is different, and the specific correspondence is shown in the table below.

[0031] Table: Comparison of Composite Material Usage in Preparation Examples 41-46 Performance testing The inorganic water-based anticorrosive coatings prepared in each embodiment were selected for testing. The test subjects were 250 samples of the inorganic water-based anticorrosive coatings, with 10 samples in each group. Their corrosion resistance, adhesion, and water resistance were tested. The specific testing steps are as follows: Adhesion: First, samples were taken from the inorganic water-based anti-corrosion coating prepared in the examples. The coating was uniformly applied to the treated steel plate surface using an air spraying method. The adhesion was tested using a pull-off test. A 20mm diameter aluminum ingot was adhered to the coating using a special fixture, and then pulled off vertically at 1MPa / s. The pull-off adhesion was measured to characterize the adhesion of the inorganic water-based anti-corrosion coating. The test results and evaluation criteria are as follows: Pull-off adhesion > 6MPa (considered high adhesion); Pull-off adhesion <6MPa (considered low adhesion).

[0032] Corrosion resistance: First, samples of the inorganic water-based anti-corrosion coating prepared in the examples were taken and uniformly coated onto the surface of a treated steel plate using an air spraying method. A cutting tool was used to make a cut through the coating to the metal substrate in the middle of the test plate, with a length ≥50mm and a width of 0.5mm. The scratched test plate was then placed at an angle in a salt spray test chamber and continuously sprayed with a 5% sodium chloride solution at 35℃ for 1500 hours. The width of the unilateral corrosion was calculated to characterize the corrosion resistance of the inorganic water-based anti-corrosion coating. The test results and evaluation criteria are as follows: Single-sided erosion width <3mm (considered as strong corrosion resistance); A single-sided erosion width > 3mm is considered as having weak corrosion resistance.

[0033] Water resistance: First, samples of the inorganic water-based anti-corrosion coating prepared in the examples were taken and uniformly coated onto the surface of the treated steel plate using an air spraying method. The test plates were then completely immersed in deionized water for 240 hours, and the surface condition of the coating was observed to characterize the stability and water resistance of the inorganic water-based anti-corrosion coating. The test results and evaluation criteria are as follows: Pass: The coating is free from blistering, whitening, rust, and peeling (considered as having strong water resistance); Unacceptable: The coating has blistering, whitening, rusting or peeling (considered as poor water resistance).

[0034] It should be specifically noted that the inorganic water-based anti-corrosion coating obtained above is an inorganic water-based anti-corrosion coating produced under normal production conditions. Any inorganic water-based anti-corrosion coatings with defects produced should be discarded.

[0035] Examples 1-7 The corresponding relationship of the preparation methods used in an inorganic water-based anti-corrosion coating is shown in the table below.

[0036] Table: Comparison of the application of inorganic water-based anticorrosive coatings in Examples 1-7 Extract the inorganic water-based anti-corrosion coatings from Examples 1-7 above, and test their pull-out adhesion, single-sided erosion width, and coating surface condition according to the above measurement steps and standards. The average value of the test results is recorded in the table below.

[0037] Table: Performance test results of adhesion pull-out strength, single-sided erosion width, and coating surface condition in Examples 1-7 As can be seen from the table above, the inorganic waterborne anticorrosive coatings prepared in Examples 1-7 all effectively improve the production efficiency of the inorganic waterborne anticorrosive coatings. The aluminum magnesium phosphate complex salt generated by the reaction of aluminum dihydrogen phosphate and magnesium oxide acts as a latent curing agent and is the core driving force for room temperature self-curing. After mixing with the composite base material, it gradually releases active phosphate ions with the evaporation of water and the penetration of carbon dioxide, triggering cross-linking. Metakaolin, after high-temperature activation with sodium polyphosphate, forms Al-OP active sites on its surface, becoming modified metakaolin. It not only significantly improves the density and hardness of the coating as a reinforcing skeleton, but also greatly enhances adhesion and impermeability through chemical bonding with silicon and phosphorus networks. Potassium silicate, lithium silicate, and acidic silica sol, under the coupling effect of the reinforcing slurry, form... The composite base material provides a stable silicon-oxygen network precursor and a suitable alkaline storage environment for the system. Flake zinc powder actively protects the substrate through cathodic protection, while nano-strontium molybdate anti-rust pigments synergistically inhibit corrosion by forming a dense passivation film in the metal anodic region through molybdate ions. Both ensure long-term corrosion resistance through a dual pathway of electrochemical and chemical passivation. The inorganic dispersant efficiently encapsulates and stably disperses all powder particles through its structure, preventing agglomeration and ensuring storage stability and coating uniformity. The silica thixotropic agent, by establishing a three-dimensional network, imparts excellent anti-sagging properties and application performance to the coating. The silica defoamer quickly eliminates air bubbles introduced during production and application, preventing pinhole defects in the coating. This achieves the goal of improving the production effect of inorganic water-based anti-corrosion coatings. Its pull-out adhesion is 7.5-9.0MPa, which is considered to be strong adhesion; the single-sided erosion width is 1.0-2.0mm, which is considered to be strong corrosion resistance; the surface condition of the coating is qualified, and the coating has no blistering, whitening, rust, or peeling, which is considered to be strong water resistance. It is evident that, given a fixed amount of raw materials, the production effect of inorganic water-based anti-corrosion coatings can be increased by adjusting the proportions of these materials. Based on the data in the table above, it is clear that the inorganic water-based anti-corrosion coating prepared using 100 parts of composite base material, 5 parts of aluminum magnesium phosphate mixture, 18 parts of modified metakaolin, 15 parts of zinc powder, 4 parts of strontium molybdate anti-rust pigment, 0.6 parts of inorganic dispersant, 0.3 parts of silica thixotropic agent, and 0.2 parts of silica defoamer exhibits the strongest adhesion. This is because the higher proportion of phosphate-activated modified metakaolin serves as the core active filler, and its abundant Al-OP active sites extensively and firmly interact with the silanol groups in the composite base material and the phosphate ions released during curing. The solid chemical bonds form an extremely high-density Si-O-Al-P three-dimensional interpenetrating cross-linked network, which greatly enhances the cohesive strength of the coating. At the same time, sufficient dispersant ensures that all solid particles, including a large amount of flake zinc powder and nano-strontium molybdate, are fully wetted and spatially stabilized, avoiding stress defects caused by particle agglomeration, resulting in a highly uniform and dense internal structure of the coating. The flake zinc powder can play a cathodic protection role under this optimized dispersion state, and its flake structure can also play a good physical reinforcement and shielding effect in the coating, further consolidating the overall integrity of the coating. The appropriate amount of curing agent ensures that the cross-linking reaction is sufficient and not too violent, avoiding the decrease in cohesive strength caused by stress concentration, as obtained from Examples 1-5.

[0038] It is evident that, given a fixed amount of raw materials, the production effect of inorganic water-based anti-corrosion coatings can be increased by adjusting the proportions of these materials. Based on the data in the table above, it is clear that the inorganic water-based anti-corrosion coating prepared using 100 parts of composite base material, 5 parts of aluminum magnesium phosphate mixture, 18 parts of modified metakaolin, 15 parts of zinc powder, 4 parts of strontium molybdate anti-rust pigment, 0.6 parts of inorganic dispersant, 0.3 parts of silica thixotropic agent, and 0.2 parts of silica defoamer exhibits the strongest corrosion resistance. This is because the high content of flake zinc powder forms a highly efficient and continuous sacrificial anode network. It provides a strong and long-lasting cathodic protection current to the substrate; at the same time, the extremely high proportion of phosphoric acid-activated modified metakaolinite, through its lamellar arrangement and surface active sites, constructs an exceptionally dense physical barrier, which greatly slows down the penetration process of corrosive media; sufficient amount of nano-strontium molybdate anti-rust pigment can effectively migrate to the metal surface, and efficiently seal the anodic area by forming a stable composite passivation film, thereby forming a synchronous inhibition of electrochemical corrosion anode and cathode reactions with the cathodic protection of zinc powder; the functional components are uniformly and stably distributed in the coating, avoiding local defects caused by agglomeration or sedimentation, as obtained from Examples 1-5.

[0039] It is evident that when the raw materials are fixed, the production effect of inorganic water-based anti-corrosion coatings can be increased by adjusting the preparation conditions. Based on the data in the table above, it is clear that when preparing the main slurry and post-treatment of the inorganic water-based anti-corrosion coating, increasing the mixing speed and duration, as well as the stirring speed and duration, initially strengthens and then weakens the adhesion and corrosion resistance of the prepared inorganic water-based anti-corrosion coating, but the change is not significant. The inorganic water-based anti-corrosion coating with the greatest adhesion and strongest corrosion resistance was obtained by adding materials while maintaining a stirring speed of 400 r / min, then increasing the stirring speed to 1200 r / min, continuously dispersing at high speed for 45 min, and then stirring for 20 min at a stirring speed of 600 r / min during post-treatment, as shown in Examples 1 and 6-7.

[0040] Examples 8-13 The corresponding relationship of the preparation methods used in an inorganic water-based anti-corrosion coating is shown in the table below.

[0041] Table: Comparison of the application of inorganic water-based anticorrosion coatings in Examples 8-13 Extract the inorganic water-based anti-corrosion coatings from Examples 8-13 above, and test their pull-out adhesion, single-sided erosion width, and coating surface condition according to the above measurement steps and standards. The average value of the test results is recorded in the table below.

[0042] Table: Performance test results of adhesion pull-off strength, single-sided erosion width, and coating surface condition in Examples 1 and 8-13 As can be seen from the table above, the inorganic waterborne anticorrosive coatings prepared in Examples 1 and 8-13 all effectively improve the production efficiency of the inorganic waterborne anticorrosive coatings. The aluminum magnesium phosphate complex salt generated by the reaction of aluminum dihydrogen phosphate and magnesium oxide acts as a latent curing agent and is the core driving force for room temperature self-curing. After mixing with the composite base material, it gradually releases active phosphate ions with the evaporation of water and the penetration of carbon dioxide, triggering cross-linking. After high-temperature activation by sodium polyphosphate, metakaolin forms Al-OP active sites on its surface, becoming modified metakaolin. It not only significantly improves the density and hardness of the coating as a reinforcing skeleton, but also greatly enhances adhesion and impermeability through chemical bonding with silicon and phosphorus networks. Potassium silicate, lithium silicate, and acidic silica sol, under the coupling effect of reinforcing slurry... A composite base material is formed, providing a stable silicon-oxygen network precursor and a suitable alkaline storage environment for the system. Flake zinc powder actively protects the substrate through cathodic protection, while nano-strontium molybdate anti-rust pigments synergistically inhibit corrosion by forming a dense passivation film in the metal anodic region through molybdate ions. Both ensure long-term corrosion resistance through a dual pathway of electrochemical and chemical passivation. The inorganic dispersant efficiently encapsulates and stably disperses all powder particles through its structure, preventing agglomeration and ensuring storage stability and coating uniformity. The silica thixotropic agent, by establishing a three-dimensional network, imparts excellent anti-sagging properties and application performance to the coating. The silica defoamer quickly eliminates air bubbles introduced during production and application, preventing pinhole defects in the coating. This achieves the goal of improving the production effect of inorganic water-based anti-corrosion coatings. Its pull-out adhesion is 7.8-8.9MPa, which is considered to be strong adhesion; the single-sided erosion width is 1.0-2.2mm, which is considered to be strong corrosion resistance; the surface condition of the coating is qualified, and the coating has no blistering, whitening, rust, or peeling, which is considered to be strong water resistance. It is evident that, given a fixed amount of raw materials, the production effect of inorganic waterborne anticorrosive coatings can be increased by adjusting the proportions of the raw materials. Based on the data in the table above, it is clear that when preparing aluminum magnesium phosphate mixtures, the inorganic waterborne anticorrosive coating prepared using 7.8 parts aluminum dihydrogen phosphate and 1 part magnesium oxide exhibits the strongest adhesion and corrosion resistance. This is because this proportion ensures complete reaction between phosphate and magnesium ions, generating aluminum magnesium phosphate complex salts with the most uniform chemical composition and structure. This highly uniform product, acting as a curing agent, has a consistent distribution of active sites, avoiding pre-reactions caused by free strong acids or alkalis during storage, thus ensuring the storage stability of the coating. After application, it responds to environmental changes at a controllable and synchronous rate, releasing active ions to uniformly and fully cross-link with silanol groups in the base material, avoiding micro-stress and structural defects caused by excessively fast or slow local reactions, as obtained in Examples 1 and 8-11.

[0043] It is evident that, given a fixed amount of raw materials, the production effect of inorganic water-based anti-corrosion coatings can be increased by adjusting the preparation conditions. Based on the data in the table above, it is clear that when preparing the aluminum-magnesium phosphate mixture, increasing the stirring temperature and duration initially strengthens and then weakens the adhesion and corrosion resistance of the resulting inorganic water-based anti-corrosion coating. The coating exhibits the highest adhesion and strongest corrosion resistance when stirred at a constant temperature of 75℃ for 2.5 hours. This is because the moderate temperature effectively promotes the ionic reaction and condensation process between aluminum dihydrogen phosphate and magnesium oxide, ensuring a complete reaction to achieve a high conversion rate and the target chemical structure, while avoiding the partial decomposition, excessive crystallization, or hard agglomeration of phosphates that may occur with excessively high temperatures. The 2.5-hour stirring time further contributes to this effect. The extended holding time provides sufficient thermodynamic relaxation time for the reaction system, allowing the precursor to be orderly transformed into uniform nano- to micron-sized complex salt particles with a more concentrated particle size distribution. This ensures excellent flowability and dispersibility of the curing agent powder and maintains high stability during coating storage. However, when the temperature is further increased or the reaction time is extended, excessive thermal processes can lead to passivation of active sites on the particle surface due to sintering, excessive particle size increase, or undesirable phase transformation. This reduces the reactivity and dispersion uniformity of the curing agent during coating curing, ultimately introducing uneven crosslinking density, micro-stress, or defects into the coating, resulting in decreased adhesion and corrosion resistance, as shown in Examples 1 and 12-13.

[0044] Examples 14-19 The corresponding relationship of the preparation methods used in an inorganic water-based anti-corrosion coating is shown in the table below.

[0045] Table: Comparison of Inorganic Waterborne Anticorrosive Coating Usage in Examples 14-19 Extract the inorganic water-based anti-corrosion coatings from Examples 14-19 above, and test their pull-out adhesion, single-sided erosion width, and coating surface condition according to the above measurement steps and standards. The average value of the test results is recorded in the table below.

[0046] Table: Performance test results of adhesion pull-out strength, single-sided erosion width, and coating surface condition in Examples 1, 14-19 As can be seen from the table above, the inorganic waterborne anticorrosive coatings prepared in Examples 1 and 14-19 all effectively improve the production efficiency of the inorganic waterborne anticorrosive coatings. The aluminum magnesium phosphate complex salt generated by the reaction of aluminum dihydrogen phosphate and magnesium oxide acts as a latent curing agent and is the core driving force for room temperature self-curing. After mixing with the composite base material, it gradually releases active phosphate ions with the evaporation of water and the penetration of carbon dioxide, triggering cross-linking. After high-temperature activation by sodium polyphosphate, metakaolin forms Al-OP active sites on its surface, becoming modified metakaolin. It not only significantly improves the density and hardness of the coating as a reinforcing skeleton, but also greatly enhances adhesion and impermeability through chemical bonding with silicon and phosphorus networks. Potassium silicate, lithium silicate, and acidic silica sol, under the coupling effect of reinforcing slurry... A composite base material is formed, providing a stable silicon-oxygen network precursor and a suitable alkaline storage environment for the system. Flake zinc powder actively protects the substrate through cathodic protection, while nano-strontium molybdate anti-rust pigments synergistically inhibit corrosion by forming a dense passivation film in the metal anodic region through molybdate ions. Both ensure long-term corrosion resistance through a dual pathway of electrochemical and chemical passivation. The inorganic dispersant efficiently encapsulates and stably disperses all powder particles through its structure, preventing agglomeration and ensuring storage stability and coating uniformity. The silica thixotropic agent, by establishing a three-dimensional network, imparts excellent anti-sagging properties and application performance to the coating. The silica defoamer quickly eliminates air bubbles introduced during production and application, preventing pinhole defects in the coating. This achieves the goal of improving the production effect of inorganic water-based anti-corrosion coatings. Its pull-out adhesion is 8.2-9.2MPa, which is considered to be strong adhesion; the single-sided erosion width is 1.3-2.3mm, which is considered to be strong corrosion resistance; the surface condition of the coating is qualified, and the coating has no blistering, whitening, rust, or peeling, which is considered to be strong water resistance. It is evident that, given a fixed amount of raw materials, the production effect of inorganic waterborne anticorrosive coatings can be increased by adjusting the proportions of the raw materials. Based on the data in the table above, it is clear that when preparing modified metakaolin, the inorganic waterborne anticorrosive coating prepared using 100 parts metakaolin and 10 parts sodium polyphosphate exhibits the strongest adhesion. This is because the appropriate proportion of sodium polyphosphate reacts fully and uniformly with the aluminum hydroxyl groups on the surface of the metakaolin during heat treatment, forming a large number of evenly distributed and strongly bonded aluminum-oxygen-phosphorus covalent active sites. These sites become high-strength chemical anchoring points connecting the inorganic matrix network during the subsequent coating curing stage, thereby greatly enhancing the overall cohesive strength of the coating. This allows all the chemically active surfaces to participate in the construction of a highly crosslinked and uniformly structured inorganic polymer network during film formation. This avoids the scarcity of chemical bonding points due to insufficient activator and also prevents the formation of a weak interface layer or decreased compatibility due to excessive activator, as obtained from Examples 1 and 14-17.

[0047] It is evident that, given a fixed amount of raw materials, the production effect of inorganic waterborne anti-corrosion coatings can be increased by adjusting the proportion of raw materials used in preparation. Based on the data in the table above, it is clear that when preparing modified metakaolin, the inorganic waterborne anti-corrosion coating prepared using 100 parts metakaolin and 11.11 parts sodium polyphosphate exhibits the strongest corrosion resistance. The reason for this is that the slightly increased amount of sodium polyphosphate ensures more thorough and in-depth phosphate chemical modification of the metakaolin surface and interlayer structure, generating a richer and stronger aluminum-oxygen-phosphorus active structure. This enhances the chemical bonding strength between the filler and the inorganic matrix network. The active sites uniformly distributed on the surface of the layers can effectively bridge the surrounding inorganic polymers during the curing process, significantly reducing microscopic defects and penetration channels within the coating, and greatly slowing down the penetration process of water, oxygen, and corrosive ions, as obtained from Examples 1 and 14-17.

[0048] It is evident that, given a fixed amount of raw materials, the production effect of inorganic water-based anti-corrosion coatings can be enhanced by adjusting the preparation conditions. Based on the data in the table above, it is clear that when preparing modified metakaolin, increasing the heating rate, calcination temperature, and calcination time during the heat treatment process initially strengthens the adhesion and corrosion resistance of the prepared inorganic water-based anti-corrosion coating, then weakens it. The coating exhibits the greatest adhesion and strongest corrosion resistance when heated to 350℃ at a rate of 5℃ / min and then calcined at this temperature for 3 hours followed by natural cooling. This is because the moderate heating rate ensures uniform heat transfer in the mixture, preventing premature decomposition of the activator or uneven phase transformation of metakaolin due to localized overheating. This calcination temperature is precisely at the point where sodium polyphosphate can effectively drive the condensation reaction between sodium polyphosphate and the aluminum hydroxyl groups on the surface and edges of metakaolin to form stable aluminum-oxygen-phosphorus bonds, while simultaneously preventing excessive dehydroxylation and loss of activity of the metakaolin itself or thermal decomposition of the phosphate components. The constant temperature time provides sufficient thermodynamic and kinetic time for the solid-phase reaction to fully penetrate and bond to the surface and interlayer of metakaolin, forming a uniform, dense, and chemically strong aluminum phosphate activated layer. This increases the chemically active sites on the filler surface, enabling it to form high-density chemical crosslinks with the inorganic matrix during coating curing, thereby significantly improving the coating's cohesive strength and adhesion. Simultaneously, its uniform coverage effectively improves the interfacial compatibility between the filler and the matrix, reducing internal defects. Furthermore, this mild and sufficient heat treatment condition avoids particle sintering hardening, decrease in specific surface area, or destruction of the active phase that may occur due to excessively high temperatures or prolonged times. This allows subsequent grinding processes to obtain powders with concentrated particle size distribution and high surface activity. Such powders are easily dispersed in the coating and form dense packing, thus constructing a physical shielding layer with extremely tortuous penetration paths, synergistically improving the long-term corrosion resistance of the coating, as obtained in Examples 1 and 18-19.

[0049] Examples 20-25 The corresponding relationship of the preparation methods used in an inorganic water-based anti-corrosion coating is shown in the table below.

[0050] Table: Comparison of Inorganic Waterborne Anticorrosion Coating Usage in Examples 20-25 Extract the inorganic water-based anti-corrosion coatings from Examples 20-25 above, and test their pull-out adhesion, single-sided erosion width, and coating surface condition according to the above measurement steps and standards. The average value of the test results is recorded in the table below.

[0051] Table: Performance test results of adhesion, single-sided erosion width, and coating surface condition in Example 1, 20-25 As can be seen from the table above, the inorganic waterborne anticorrosive coatings prepared in Examples 1 and 20-25 all effectively improve the production efficiency of the inorganic waterborne anticorrosive coatings. The aluminum magnesium phosphate complex salt generated by the reaction of aluminum dihydrogen phosphate and magnesium oxide acts as a latent curing agent and is the core driving force for room temperature self-curing. After mixing with the composite base material, it gradually releases active phosphate ions with water evaporation and carbon dioxide penetration, triggering cross-linking. Metakaolin, after high-temperature activation with sodium polyphosphate, forms Al-OP active sites on its surface, becoming modified metakaolin. It not only significantly improves the density and hardness of the coating as a reinforcing skeleton but also greatly enhances adhesion and impermeability through chemical bonding with silicon and phosphorus networks. Potassium silicate, lithium silicate, and acidic silica sol, under the coupling effect of reinforcing slurry... A composite base material is formed, providing a stable silicon-oxygen network precursor and a suitable alkaline storage environment for the system. Flake zinc powder actively protects the substrate through cathodic protection, while nano-strontium molybdate anti-rust pigments synergistically inhibit corrosion by forming a dense passivation film in the metal anodic region through molybdate ions. Both ensure long-term corrosion resistance through a dual pathway of electrochemical and chemical passivation. The inorganic dispersant efficiently encapsulates and stably disperses all powder particles through its structure, preventing agglomeration and ensuring storage stability and coating uniformity. The silica thixotropic agent, by establishing a three-dimensional network, imparts excellent anti-sagging properties and application performance to the coating. The silica defoamer quickly eliminates air bubbles introduced during production and application, preventing pinhole defects in the coating. This achieves the goal of improving the production effect of inorganic water-based anti-corrosion coatings. Its pull-out adhesion is 7.8-9.1MPa, which is considered to be strong adhesion; the single-sided erosion width is 1.2-2.2mm, which is considered to be strong corrosion resistance; the surface condition of the coating is qualified, and the coating has no blistering, whitening, rust, or peeling, which is considered to be strong water resistance. It is evident that, given a fixed amount of raw materials, the production effect of inorganic water-based anti-corrosion coatings can be increased by adjusting the proportions of these materials. Based on the data in the table above, it is clear that when preparing the composite base material, the inorganic water-based anti-corrosion coating prepared using 40 parts potassium silicate, 20 parts lithium silicate, 25 parts acidic silica sol, and 15 parts reinforcing slurry exhibits the strongest adhesion and corrosion resistance. This is because the stable alkaline environment provided by the potassium silicate and lithium silicate ensures excellent storage stability and good film-forming leveling properties of the base material. Meanwhile, the acidic silica sol acts as a uniformly dispersed active silicon source and acidic reaction point. The acidic environment it introduces forms a moderate buffer with the alkaline silicates, preventing premature gelation of the system and creating ideal conditions for the subsequent acid-base triggered reaction with the latent curing agent. This mass ratio of reinforcing slurry plays a key coupling and bridging role under this formulation. It can efficiently condense with the silicon-oxygen network in acidic silica sol and silicates, improving the flexibility and permeability of the system, thereby forming a strong chemical bond and mechanical interlock between the coating and the metal substrate. Under the blending of the reinforcing slurry, the alkaline silicates and acidic silica sol form a uniform inorganic network with high cross-linking density, continuous three-dimensional structure and very few defects during curing, giving the coating extremely high cohesive strength. Its highly dense microstructure also builds an excellent physical barrier against water, oxygen and corrosive ion penetration, providing a stable and conductive support matrix for functional fillers such as flake zinc powder and strontium molybdate pigment, ensuring the long-term synergistic effect of electrochemical cathodic protection and chemical passivation, as obtained from Examples 1 and 20-23.

[0052] It is evident that when the raw materials are fixed, the production effect of inorganic waterborne anticorrosive coatings can be increased by adjusting the preparation conditions. Based on the data in the table above, it is not difficult to see that when preparing the composite base material, increasing the stirring speed, the duration of continuous dripping, and the stirring time first strengthens and then weakens the adhesion and corrosion resistance of the prepared inorganic waterborne anticorrosive coating, but the change is not significant. When the inorganic waterborne anticorrosive coating is prepared by continuous dripping at a stirring speed of 500 r / min for 30 min and then stirring for 60 min under the same conditions, the adhesion and corrosion resistance are the greatest, as obtained from Examples 1 and 24-25.

[0053] This specific embodiment is merely an explanation of the present invention and not a limitation thereof. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but as long as they are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. An inorganic water-based anticorrosive coating characterized by, The inorganic water-based anticorrosive coating preparation raw materials include, in parts by weight: The composite base 100 parts, the aluminum magnesium phosphate mixture 4-7.5 parts, the modified metakaolin 12-20 parts, the zinc powder 8-15 parts, the strontium molybdate anti-rust pigment 2-4 parts, the inorganic dispersant 0.3-0.7 parts, the silica thixotropic agent 0.1-0.4 parts and the silica defoaming agent 0.1-0.3 parts.

2. The inorganic water-borne anticorrosive coating according to claim 1, characterized in that: The preparation method of the aluminum magnesium phosphate mixture comprises the following steps: C1, the aluminum dihydrogen phosphate solution is poured into the reaction kettle, and the magnesium oxide powder is added into the reaction kettle under the condition that the temperature is lower than 40℃ and the stirring speed is 200r / min; then the temperature is increased to 75-85℃, and constant temperature stirring is carried out under the same condition for 2.5-3.5h, to obtain a viscous slurry; The solid content of the aluminum dihydrogen phosphate solution is 50%; C2, the viscous slurry obtained in C1 is transferred to a spray drying tower, and spray drying is carried out under the condition that the inlet air temperature is 180℃, the outlet air temperature is 90℃ and the atomization pressure is 0.3MPa, to obtain the aluminum magnesium phosphate mixture.

3. The inorganic water-borne anticorrosive coating according to claim 1, characterized in that: The preparation raw materials of the aluminum magnesium phosphate mixture and the parts by weight of each component are as follows: The aluminum dihydrogen phosphate 5.5-10 parts, the magnesium oxide 1 part.

4. The inorganic water-borne anticorrosive coating according to claim 1, characterized in that: The preparation method of the modified metakaolin comprises the following steps: B1, the metakaolin and the sodium polyphosphate are mixed and placed in a muffle furnace, and the temperature is increased to 320-380℃ at a temperature increasing rate of 3-8℃ / min, and then the calcination product is obtained after the calcination at this temperature for 2.5-4h and natural cooling; B2, the calcination product obtained in B1 is poured into a planetary ball mill, and dry grinding is carried out under the condition that the rotating speed is 350r / min for 2h; after grinding, the modified metakaolin is obtained by passing through a 150 mesh standard sieve.

5. The inorganic water-borne anticorrosive coating according to claim 1, characterized in that: The preparation raw materials of the modified metakaolin and the parts by weight of each component are as follows: The metakaolin 100 parts, the sodium polyphosphate 8.33-12.5 parts.

6. The inorganic water-borne anticorrosive coating according to claim 1, characterized in that: The preparation method of the composite base comprises the following steps: A1, under the protection of nitrogen, the potassium water glass, the lithium water glass and the acid silica sol are sequentially added into a high-speed dispersion kettle to obtain A phase; The modulus of the potassium water glass is 3.3; The modulus of the lithium water glass is 2.0; The pH of the acid silica sol is 2.5, and the solid content is 30%; A2, the A phase obtained in A1 is added with the reinforcing slurry through a constant pressure dropping funnel under the stirring condition that the rotating speed is 400-600r / min, and the dropping is continuously added for 20-40min; after the dropping is completed, the stirring is maintained under the same condition for 50-70min to obtain the composite base; The reinforcing slurry is composed of the active silica sol and the silica ash with a weight ratio of 1:

1.

7. The inorganic water-borne anticorrosive coating according to claim 1, characterized in that: The preparation raw materials of the composite base and the parts by weight of each component are as follows: The potassium water glass 35-45 parts, the lithium water glass 15-25 parts, the acid silica sol 20-30 parts and the reinforcing slurry 10-20 parts.

8. The inorganic water-borne anticorrosive paint according to claim 1, characterized by: The inorganic dispersant is composed of the sodium hexametaphosphate and the sodium tripolyphosphate with a weight ratio of 1:1; The silica thixotropic agent is a hydrophobic modified fumed silica thixotropic agent; The silica defoaming agent is a hydrophobic modified silica defoaming powder.

9. Process for the preparation of an inorganic aqueous anticorrosive paint according to any one of claims 1-8, characterized in that, The preparation method of the inorganic water-based anticorrosive coating comprises the following steps: S1, the composite base is put into a high-speed dispersion kettle, under the condition that the stirring speed is kept at 350-450 r / min, aluminum magnesium phosphate mixture, modified metakaolin, zinc powder, strontium molybdate anti-rust pigment and inorganic dispersant are added, then the stirring speed is increased to 1100-1300 r / min, and high-speed dispersion is continued for 40-50 min to obtain a preliminary dispersion slurry; S2, the preliminary dispersion slurry obtained in S1 is transferred to a sand mill, zirconia beads with a diameter of 0.6 mm are used as grinding media, and the slurry is ground to a fineness of not more than 20 um under the condition of circulating water cooling; then silica thixotropic agent and silica defoaming agent are added to the slurry, and stirring is carried out at a speed of 550-650 r / min for 18-22 min, followed by vacuum degassing at-0.09 MPa for 20 min, and filtering with a 300 mesh filter to obtain an inorganic water-based anticorrosive coating.

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