Inorganic composite water-based metal anticorrosive paint and preparation method thereof

Abstract

The invention discloses an inorganic composite water-based metal anticorrosive paint and a preparation method thereof, and the paint is prepared from the following raw materials by weight: 50-70% of a water-based acrylate dispersion liquid, 4-6% of a tinting pigment, 15-22% of a filler, 0.5-1.5% of an antifoaming agent, 0.4-0.6% of a wetting dispersant, 0.4-0.6% of a leveling agent, 2-4% of a coalescing agent, a proper amount of a pH regulator, and the balance of a solvent. And the pH value of the inorganic composite water-based metal anticorrosive paint is 10.5-11.5. The coating disclosed by the invention has excellent adhesive force, flame retardance, chemical resistance and weather resistance, is suitable for various industrial anti-corrosion occasions, and has a good application prospect.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of paint technology, in particular to an inorganic composite water-based metal anticorrosive paint and a preparation method thereof. BACKGROUND

[0002] Environmental protection and sustainable development are increasingly valued, and under such a background, the demand for low-carbon and environmentally friendly building materials and coating products has also increased dramatically. However, although the traditional water-based industrial anticorrosive paint has improved in environmental performance, it still has deficiencies in adhesion, salt spray resistance, weather resistance and other aspects. In addition, its high VOC content is also contrary to the current international trend of green and low carbon. SUMMARY

[0003] The present application discloses an inorganic composite water-based metal anticorrosive paint and a preparation method thereof, to solve the technical problems of poor adhesion, salt spray resistance, weather resistance, VOC content and other aspects of the metal anticorrosive paint of the prior art.

[0004] In a first aspect, an inorganic composite water-based metal anticorrosive paint is provided, which is prepared from raw materials in the following weight percentages: water-based acrylic ester dispersion 50-70%, coloring pigment 4-6%, filler 15-22%, defoaming agent 0.5-1.5%, wetting dispersant 0.4-0.6%, leveling agent 0.4-0.6%, film-forming aid 2-4%, appropriate amount of pH adjuster, and the rest is solvent. The pH of the inorganic composite water-based metal anticorrosive paint is 10.5-11.5.

[0005] In a second aspect, a preparation method of an inorganic composite water-based metal anticorrosive paint is provided, comprising: The raw materials of the inorganic composite water-based metal anticorrosive paint according to the first aspect are weighed; The raw materials of the inorganic composite water-based metal anticorrosive paint are added to a reaction kettle, stirred at a speed of 800 rpm under normal temperature and pressure, and mixed for 80 minutes to obtain the inorganic composite water-based metal anticorrosive paint with a pH value of 10.8-11.3.

[0006] The embodiments of the present application have the following beneficial effects: 1. The combustion rating of the inorganic composite water-based metal anticorrosive paint of the embodiments of the present application has reached A2 level, perfectly meeting the requirements of GB50222-2017 "Fireproof Specification for Interior Decoration Design of Buildings", and ensuring that the interior decoration of buildings has higher safety performance when facing fire risks, providing strong protection for the safety of users' lives and property.

[0007] 2. The inorganic composite water-based metal anti-corrosion coating of this invention possesses excellent chemical corrosion resistance, effectively resisting strong corrosive media such as 20% hydrochloric acid, sulfuric acid, and 20% sodium hydroxide. This characteristic makes the coating of this invention widely applicable in fields such as chemical and pharmaceutical industries where extremely high corrosion resistance is required.

[0008] 3. The inorganic composite water-based metal anti-corrosion coating of this invention adopts low-carbon carbon fixation technology. During the curing process, potassium silicate and lithium silicate interact with carbon dioxide, transforming into silica gel and potassium carbonate and lithium carbonate, or forming stable silicon-oxygen bonds through dehydration. This process not only helps reduce carbon emissions but also improves the mechanical properties and environmental adaptability of the material.

[0009] 4. The inorganic composite water-based metal anti-corrosion coating of this invention exhibits a pull-out strength exceeding 5 MPa with the cold-rolled sandblasted steel sheet, and undergoes various chemical reactions with the metal surface, thereby ensuring a strong adhesion between the coating and the metal substrate. This highly efficient combination of adhesion strength makes the coating less prone to peeling off during long-term use, improving the product's service life and stability.

[0010] 5. The inorganic composite water-based metal anti-corrosion coating of this invention exhibits a neutral salt spray resistance of over 720 hours, demonstrating excellent weather resistance. In harsh natural environments, such as coastal areas, it maintains good appearance and performance, extending the service life of buildings.

[0011] 6. The VOC content in the film-forming material of the inorganic composite water-based metal anti-corrosion coating of this invention is strictly controlled below 50g / L, significantly reducing environmental pollution and meeting green environmental protection standards. This low VOC content design minimizes the negative environmental impact of this invention during production and application, embodying the concept of green and sustainable development. Attached Figure Description

[0012] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a schematic flowchart illustrating the preparation method of the inorganic composite water-based metal anti-corrosion coating according to an embodiment of the present invention. Detailed Implementation

[0014] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0015] This invention discloses an inorganic composite water-based metal anti-corrosion coating. Specifically, the anti-corrosion coating is prepared using the following raw materials in weight percentages: 50-70% water-based acrylic dispersion, 4-6% coloring pigment, 15-22% filler, 0.5-1.5% defoamer, 0.4-0.6% wetting and dispersing agent, 0.4-0.6% leveling agent, 2-4% film-forming aid, appropriate amount of pH adjuster, and the remainder being solvent.

[0016] Preferably, the anti-corrosion coating is prepared using the following raw materials in weight percentages: 55-65% aqueous acrylic dispersion, 5% coloring pigment, 15-25% filler, 1% defoamer, 0.5% wetting and dispersing agent, 0.5% leveling agent, 3% film-forming aid, 1% pH adjuster, and the remainder being solvent.

[0017] The pH of the inorganic composite water-based metal anti-corrosion coating is 10.5~11.5. Preferably, the pH of the inorganic composite water-based metal anti-corrosion coating is 10.8~11.3.

[0018] Specifically, there are no special requirements for the coloring pigments used in the embodiments of the present invention. To ensure that the prepared coating has a good film effect, inorganic pigments with good weather resistance are preferred as coloring pigments, and the specific materials used can be determined according to customer needs.

[0019] Specifically, the defoamer is BASF 2410.

[0020] Specifically, the wetting and dispersing agent is BASF 4140AS.

[0021] Specifically, the leveling agent is BYK 333.

[0022] Specifically, the film-forming aid is alcohol ester-12.

[0023] Specifically, the pH adjuster is AMP95, whose main component is 2-amino-2-methyl-1-propanol, which is environmentally friendly and has low volatility.

[0024] Specifically, the solvent is water, preferably deionized water. Inorganic composite water-based metal anti-corrosion coatings obtained using water as a solvent are more in line with environmental protection requirements.

[0025] Specifically, the filler includes at least one of the following: calcium carbonate, barium sulfate, and calcined kaolin. The particle size of the filler is 800~1500 nm.

[0026] More specifically, the calcium carbonate is preferably 1250 mesh industrial grade, with a calcium content of 98% or higher. The calcined kaolin is 1500 mesh water-washed kaolin specifically for water-based coatings. The barium sulfate, at 1000 mesh, has a content ≥98%.

[0027] Specifically, the aqueous acrylate dispersion is prepared using the following raw materials in weight percentages: 60% aqueous acrylate, 38% inorganic nano-silicate dispersion, 1% pH adjuster and 1% epoxy silane coupling agent.

[0028] Specifically, the preparation method of the aqueous acrylate dispersion is as follows: Step 1: At room temperature, add a pH adjuster to the aqueous acrylate to adjust the pH value to 10.5~11.5, then disperse at 600 rpm for 30 minutes to obtain the first mixture.

[0029] Specifically, the water-based acrylate is preferably BASF 7080, and the pH adjuster is preferably AMP95.

[0030] Step 2: Add epoxy silane coupling agent dropwise to the first mixture and disperse at 600 rpm at room temperature for 30 minutes to obtain the second mixture.

[0031] Specifically, the epoxy silane coupling agent is preferably KH560.

[0032] Step 3: Add inorganic nano-silicate dispersion to the second mixture, disperse at 600 rpm at room temperature for 10 minutes, then heat to 80℃ and disperse at 600 rpm for 130 minutes to obtain aqueous acrylate dispersion.

[0033] The inorganic nano-silicate dispersion was prepared using the following raw materials in weight percentages: 39% first nano-silica solution with a silica particle size of 8-10 nm, 38% second nano-silica solution with a silica particle size of 10-15 nm, 15% potassium silicate, 7% lithium silicate, and 1% epoxy silane coupling agent. The modulus of potassium silicate was 3.5-4.0, and the modulus of lithium silicate was 3.0-3.5. The mass percentage of silica in the first and second nano-silica solutions was 35-41%.

[0034] Using nano-silica of the two particle sizes mentioned above can optimize the filling effect and improve the material's density. From a physical structure perspective, particles of different sizes can form a more compact packing structure. Larger nano-silica particles act as a framework, providing basic support, while smaller particles fill the gaps between larger particles, reducing the material's internal porosity. This "graded filling" structure can significantly improve the material's density and mechanical strength. Using nano-silica of these two particle sizes can also enhance surface uniformity and reduce defects. In coatings or thin film materials, nano-silica of a single particle size may cause surface defects due to uneven particle packing. By combining particles of different sizes, a more uniform surface distribution can be achieved, reducing agglomeration and voids, thereby improving the coating's smoothness and optical properties. Using nano-silica of these two particle sizes can also improve thermal expansion matching. Nano-silica of different particle sizes may have different coefficients of thermal expansion. Through proper combination, the thermal expansion behavior of the composite material can be adjusted to more closely resemble the thermal expansion characteristics of the substrate, thereby reducing cracking or peeling caused by thermal stress. Using nano-silica of the two particle sizes mentioned above can also enhance interfacial bonding. In composite materials, nano-silica of different particle sizes can form interfacial bonds with the substrate at different scales. Large particles provide macroscopic support, while small particles enhance the microscopic bonding force of the interface, thereby improving the overall bonding strength and durability of the material. Using nano-silica of the two particle sizes mentioned above can also enhance rheological properties. In liquid or colloidal systems, nano-silica of different particle sizes can construct multi-layered physical network structures. Small-diameter particles provide high specific surface area and strong interactions, while large-diameter particles help form a skeletal structure, thereby improving the rheological properties of the material and giving it better thixotropy and anti-sagging properties during construction.

[0035] Specifically, the preparation method of the inorganic nano-silicate dispersion is as follows: Step 1: Mix the first nano-silica solution and the second nano-silica solution at room temperature and disperse them at 400 rpm to obtain a third mixture.

[0036] Step 2: At room temperature, add a pH adjuster to the third mixture to adjust the pH value to 11.2 to 12.8 (preferably 11.5 to 12.5), then add potassium silicate and lithium silicate, and disperse for 30 minutes to obtain the fourth mixture.

[0037] The pH adjuster is AMP95. Potassium silicate and lithium silicate can be added slowly to ensure complete reaction.

[0038] Step 3: After adding epoxy silane coupling agent dropwise to the fourth mixture, disperse it at 550 to 680 rpm for 8 to 14 minutes, then heat it to 60 to 72°C, disperse it at 550 to 680 rpm for 115 to 145 minutes, and let it stand for 24 hours to obtain the inorganic nano silicate dispersion.

[0039] Step three is preferably to add an epoxy silane coupling agent dropwise to the fourth mixture, disperse it at 600 rpm for 10 minutes, heat it to 65°C, disperse it at 600 rpm for 130 minutes, and let it stand for 24 hours to obtain the inorganic nano silicate dispersion.

[0040] The rate of adding the epoxy silane coupling agent can be 30 drops / min.

[0041] Because silica is highly reactive and unstable, especially small-particle silica, it readily reacts directly with polymer resins to dehydrate, leading to demulsification and preventing film formation. In this invention, silica, potassium silicate, and lithium silicate are hydrolyzed and grafted using an epoxy silane coupling agent. After standing for 24 hours, they are grafted with waterborne acrylate at 80°C to obtain a waterborne acrylate dispersion. This dispersion exhibits good storage stability, showing no demulsification or stratification even after long-term exposure to environments ranging from -5°C to 50°C; it also does not delaminate or crack. The waterborne acrylate dispersion itself provides excellent corrosion resistance, flame retardancy, and flash rust prevention for coatings, and also enhances adhesion.

[0042] It should be noted that pH value has a decisive influence on the hydrolysis and condensation reaction rate and dispersion stability of silicates when preparing inorganic nano-silicate dispersions. By establishing the silicate hydrolysis and condensation mechanism equation and combining orthogonal experimental design and game model calculations, the pH adjustment range was optimized to 11.2 to 12.8.

[0043] Mechanism equation establishment: The silicate condensation degree evolution equation is used to describe the relationship between the silicon-oxygen bond formation rate and the dispersion stability under different pH conditions. The inputs include hydrogen ion concentration. (mol / L), silicate ion concentration (mol / L), reaction temperature (K) and reaction time (min), the output is the degree of condensation. (Dimensionless): ; in, For frequency factor (min) ·mol ·L ·mol ·L ), The activation energy is (J / mol). Let J be the gas constant (J / (mol·K)). The dimensionless quantity on the left side of the equation is min. The dimensionless product of the exponent (dimensionless) and the concentration term on the right is unified to min. This equation indicates that the pH value increases (i.e., Lowering the pH will accelerate the polycondensation reaction, but too high a pH will lead to rapid gelation.

[0044] Experimental Design and Data Analysis: A five-level orthogonal experiment was designed with pH values ​​of 11.0, 11.5, 12.0, 12.5, and 13.0. Inorganic nano-silicate dispersions were prepared at room temperature (25℃), and the viscosity change rate and Zeta potential were measured over 30 days. Experimental data showed that at pH=11.0, the Zeta potential was -28 mV, indicating poor dispersion stability, with a 42% viscosity increase over 30 days. From pH=11.5 to 12.5, the Zeta potential remained in the range of -35 to -42 mV, and the viscosity increase rate was controlled between 15% and 22%. At pH=13.0, although the Zeta potential reached -45 mV, the condensation reaction was too rapid, and gel particles appeared within 3 days. Through nonlinear fitting of the experimental data, the optimal pH window was determined to be 11.2 to 12.8, which ensures sufficient electrostatic repulsion (absolute Zeta potential > 32 mV) while avoiding excessively rapid condensation leading to system instability.

[0045] Game Theory Model Construction: A two-layer game theory model was established to optimize the pH control strategy. The upper-layer model aims to maximize the long-term stability of the silicate dispersion, with the objective function as follows:

[0046] The stability evaluation function This method is used to comprehensively evaluate the charge repulsion and viscosity stability of dispersions. Inputs include the absolute value of the Zeta potential. (mV), viscosity change rate (mPa·s / day) and degree of condensation (Dimensionless), the output is a stability score (dimensionless). mV , day / (mPa·s), Weighting coefficients, coupling terms This demonstrates the negative impact of the degree of condensation on stability.

[0047] The lower-level model aims to moderate the reactivity, and the objective function is:

[0048] The reaction regulation function To balance the reaction rate with the risk of excessive polycondensation, the input includes the effective reaction rate constant. (min ), target condensation degree (Take 0.65, dimensionless), actual degree of condensation (dimensionless), absolute value of Zeta potential (mV) and hydrogen ion concentration (mol / L), the output is a reaction regulation score (dimensionless). min、 mV ·mol ·L Coupling terms Characterize the synergistic effect of pH on potential and reaction rate.

[0049] The constraints include: , mV, , mPa·s / day. Solving the two-level game model using a genetic algorithm, the optimal pH range corresponding to the Nash equilibrium solution is found to be 11.2 to 12.8. Within this range, the stability score of the upper-level model is... The lower-level model response regulation score ranged from 0.82 to 0.91. The optimal balance is achieved when the ratio reaches 0.76 to 0.88.

[0050] In a specific embodiment of the present invention, after multiple experimental verifications, the preferred pH range was found to be 11.5 to 12.5.

[0051] It should be noted that, through fluid dynamics mechanism equations and multi-factor experiments, the dispersion rotation speed was optimized to 550 to 680 rpm, the initial dispersion time to 8 to 14 minutes, the heating temperature to 60 to 72℃, and the high-temperature dispersion time to 115 to 145 minutes. These results were obtained through the calculation process described below in detail: Fluid shear mechanism equation: The nanoparticle dispersion efficiency equation is used to quantify the effect of stirring shear force on the breakup of agglomerates. Inputs include rotational speed. (rpm), impeller diameter (m), liquid viscosity (Pa·s) and dispersion time (min), the output is the dispersion uniformity. (dimensionless, 0 to 1): ; in, (Dimensionless coefficients after unit conversion) Let be the liquid volume (L). Both sides of the equation are dimensionless. This equation shows that the dispersion uniformity increases with the 1.5th power of the rotational speed, but excessively high rotational speeds can introduce bubbles and increase energy consumption.

[0052] Temperature-mass transfer equation: The epoxy group reaction conversion equation is used to describe the promoting effect of temperature on the condensation reaction of silane coupling agents and silicates. The inputs include the reaction temperature. (K), reaction time (min) and coupling agent concentration (wt%), the output is the conversion rate. (Dimensionless):

[0053] in To achieve the maximum conversion rate, min ·wt% , J / mol represents the activation energy of the reaction. Dimensional analysis: The exponential term is dimensionless, and the overall equation is unified to dimensionless.

[0054] Multifactor orthogonal experiment: Design of a four-factor, five-level orthogonal experiment L (5 Factors considered included initial dispersion speed (500, 550, 600, 650, 700 rpm), initial dispersion time (6, 8, 10, 12, 14 min), reaction temperature (55, 60, 65, 70, 75℃), and high-temperature dispersion time (100, 115, 130, 145, 160 min). Evaluation indices were the average particle size of the dispersion, particle size distribution width, and coupling agent grafting rate. Experimental results showed that at initial speeds of 550 to 680 rpm, the average particle size stabilized at 22 to 28 nm, with a particle size distribution index (PDI) < 0.25. Significant agglomeration (particle size > 35 nm) was observed below 550 rpm, while microbubbles were detected above 680 rpm, leading to decreased stability. An initial dispersion time of 8 to 14 minutes was sufficient to break up primary agglomerates; less than 8 minutes resulted in an agglomeration residue rate > 8%, while more than 14 minutes showed little improvement but increased energy consumption. At a reaction temperature of 60 to 72°C, the grafting rate of the coupling agent reaches 78% to 86%. If the temperature is too low (<60°C), the reaction is incomplete (grafting rate <70%), and if the temperature is too high (>72°C), some acrylate components will degrade. A high-temperature dispersion time of 115 to 145 minutes enables a reaction conversion rate of 85% to 91%. Insufficient time results in incomplete grafting, while excessive time increases energy consumption without significantly improving the effect.

[0055] Two-layer game model optimization: The upper-layer model aims to achieve optimal nanoparticle dispersion quality. ; The dispersion quality evaluation function This is used to comprehensively consider dispersion uniformity, particle size distribution, and energy consumption. Inputs include dispersion uniformity. (dimensionless), particle size distribution index (dimensionless), rotational speed (rpm) and initial dispersion time (min), the output is the dispersion quality score (dimensionless). , , rpm ·min Coupling terms Impact of normalized energy consumption.

[0056] The lower-level model aims to maximize the effect of chemical modification: ; The modified efficiency function This method is used to optimize the promoting effect of temperature and time on the grafting reaction and control side reactions. Inputs include conversion rate. (dimensionless), reaction temperature (K) and high-temperature dispersion time (min), the output is the modification efficiency score (K) ·min ).in K ·min, (dimensionless) K ·min Coupling terms This demonstrates the synergistic effect between conversion rate and temperature.

[0057] Constraints: rpm min、 ℃ min、 , The Particle Swarm Optimization (PSO) algorithm was used to obtain the Pareto optimal solution set. After comprehensive consideration, the parameter range was determined as follows: rotation speed 550 to 680 rpm, initial dispersion 8 to 14 min, temperature 60 to 72℃, and high-temperature dispersion 115 to 145 min. Inorganic nano-silicate dispersions prepared within this parameter range exhibited an average nanoparticle size of 24±3 nm, PDI = 0.18±0.04, and a coupling agent grafting rate of 82±4%. They demonstrated excellent 30-day storage stability, and when applied to metal anti-corrosion coatings, the salt spray corrosion resistance time increased from the original 480 hours to over 720 hours, significantly improving the technical performance. This parameter optimization scheme achieved a multi-objective balance between dispersion quality, chemical modification, and energy consumption, providing a scientific basis for industrial production.

[0058] Specifically, the rust prevention technology principle of the inorganic composite water-based metal anti-corrosion coating of this invention is as follows: 1. The hydrolysis reaction of the mixture of potassium silicate and nano-silica with the epoxy-based silane coupling agent is as follows: The reaction of potassium silicate (K2SiO3) with epoxysilane coupling agents (e.g., KH560): K₂SiO₃ + 2KH₅₆O → 2K + + 2SiO3 2- + 2R-O-Si(OH)3 In this context, RO-Si(OH)3 represents the organic group of the epoxy silane coupling agent.

[0059] 2. The reaction between the hydrolysis of nano-silica and the epoxy-based silane coupling agent is as follows: Hydrolysis of nano-silica (mainly composed of SiO2·nH2O) and its reaction with epoxy-based silane coupling agents: SiO2·nH2O + KH560 → Si(OH)4+ K + + RO-Si(OH)3 3. The grafting reaction between monomers and silicate ions in acrylate emulsions is as follows: Si(OH)4+ M(AA)n → [Si-OM(AA)] n + 4H2O In this context, M(AA)n represents the polymer chain of the acrylate monomer, and AA represents the acrylate group.

[0060] 4. Reaction of aqueous acrylic dispersion applied to a metal substrate: (1) Silicates react with carbon dioxide in the air to form carbonates: SiO3 2- + CO2 + H2O → H2SiO3 + CO3 2- (2) The complexation reaction between free silicate ions and free iron ions forms iron silicate:

[0061] (3) Lithium ion Li + and potassium ions K + Mechanism of cooperation: Metal + Li + → Lithium metal salt + metal ions; Metal oxide + K + → Stable potassium metal salt + water Silicate ions (SiO3) 2- ) and free iron ions (Fe 2+ Fe 3+ A complexation reaction occurs, reducing the concentration of metal ions and lowering the corrosion rate of the metal substrate. Silicates undergo dehydration to form stable silicon-oxygen bonds, creating a tightly bonded coating on the metal surface. Lithium-ion coatings, due to their small ionic radius and high reactivity, typically form a denser and more uniform protective layer, thus exhibiting superior corrosion resistance compared to potassium-ion coatings. Although lithium-ion coatings may not be as stable as potassium-ion coatings at high temperatures, combining the two can enhance the coating's temperature resistance under high-temperature conditions, expanding its application range in anti-corrosion coatings. The differences in properties between lithium and potassium ions complement each other in anti-corrosion coating technology; lithium-ion coatings are suitable for long-term corrosion protection, while potassium-ion coatings are suitable for rapid initial protection. By combining lithium and potassium ions, anti-corrosion coatings can possess multiple functions such as corrosion resistance, self-healing, and antibacterial properties.

[0062] The above reaction process demonstrates the chemical reaction process from the modification of potassium silicate and nano-silica to the formation of an aqueous acrylate dispersion, and then to the application of the coating on the metal substrate.

[0063] This invention also discloses a method for preparing an inorganic composite water-based metal anti-corrosion coating, such as... Figure 1 As shown, the method includes the following steps: Step S101: Weigh the raw materials for the inorganic composite water-based metal anti-corrosion coating.

[0064] The raw material ratio has been described above and will not be repeated here.

[0065] Step S102: Add the raw materials of the inorganic composite water-based metal anti-corrosion coating into the reaction vessel, stir at 800 rpm at room temperature and pressure, and mix for 80 minutes to obtain an inorganic composite water-based metal anti-corrosion coating with a pH value of 10.8~11.3.

[0066] The technical solution of the present invention will be further described below with specific embodiments to demonstrate the effects of the combination of nano-silica, the amount of silane coupling agent, potassium silicate, and lithium silicate, as well as the dispersion time, temperature, and standing time on the performance of the final aqueous acrylate dispersion.

[0067] Examples 1-3 are examples of preparing inorganic nano-silicate dispersions. The specific preparation process is as follows: An 8-10 nm silica solution and a 10-15 nm silica solution were mixed at room temperature and dispersed at 400 rpm to obtain a third mixture. A pH adjuster was added dropwise to the third mixture at room temperature to adjust the pH to 11.5-12.5. Potassium silicate and lithium silicate were then added and dispersed for 30 minutes to obtain a fourth mixture. An epoxy silane coupling agent was added dropwise to the fourth mixture, and it was dispersed at 600 rpm for 10 minutes. The mixture was then heated to 65°C and dispersed at 600 rpm for 130 minutes. After standing for 24 hours, an inorganic nano-silicate dispersion was obtained.

[0068] Example 1 The raw material composition of Example 1 is shown in Table 1.

[0069] Table 1 Raw material ratios for Example 1

[0070] Example 2 The raw material composition of Example 2 is shown in Table 2.

[0071] Table 2 Raw material ratios for Example 2

[0072] Example 3 The raw material composition of Example 3 is shown in Table 3.

[0073] Table 3 Raw material ratios for Example 3

[0074] Comparative Example 1 The difference between Comparative Example 1 and Example 3 is that the 8-10 nm silica solution was replaced with a 10-15 nm silica solution; otherwise, they are the same as in Example 3. The raw material composition of Comparative Example 1 is shown in Table 4.

[0075] Table 4 Raw material ratio of Comparative Example 1

[0076] Comparative Example 2 The difference between Comparative Example 2 and Example 3 is that lithium silicate (3.0-3.5 modulus) was replaced with potassium silicate (3.5-4.0 modulus), otherwise the same as Example 3. The raw material composition of Comparative Example 2 is shown in Table 5.

[0077] Table 5 Raw material ratios for Comparative Example 2

[0078] Comparative Example 3 The difference between Comparative Example 3 and Example 3 is that the epoxy silane coupling agent is replaced with an amino silane coupling agent; otherwise, they are the same as in Example 3. The raw material composition of Comparative Example 3 is shown in Table 6.

[0079] Table 6 Raw material ratios for Comparative Example 3

[0080] Comparative Example 4 The difference between Comparative Example 4 and Example 3 is that the dispersion time after heating to 65°C for 130 minutes was replaced with the dispersion time after heating to 65°C for 60 minutes; otherwise, they are the same as in Example 3. The raw material composition of Comparative Example 4 is shown in Table 7.

[0081] Table 7 Raw material ratios for Comparative Example 4

[0082] Comparative Example 5 The difference between Comparative Example 5 and Example 3 is that the temperature increase of 65°C was replaced with room temperature, while the rest is the same as Example 3. The raw material composition of Comparative Example 5 is shown in Table 8.

[0083] Table 8 Raw material ratios for Comparative Example 5

[0084] Comparative Example 6 The difference between Comparative Example 6 and Example 3 is that potassium silicate (3.5-4.0 modulus) was replaced with potassium silicate (3.0-3.5 modulus), otherwise it was the same as Example 3. The raw material composition of Comparative Example 6 is shown in Table 9.

[0085] Table 9 Raw material ratios for Comparative Example 6

[0086] Comparative Example 7 The difference between Comparative Example 7 and Example 3 is that 8-10 nm silica was replaced with 5-8 nm silica; otherwise, they are the same as in Example 3. The raw material composition of Comparative Example 7 is shown in Table 10.

[0087] Table 10 Raw material ratios for Comparative Example 7

[0088] Comparative Example 8 The difference between Comparative Example 8 and Example 3 is that 8-10 nm silica was replaced with 15-30 nm silica; otherwise, they are the same as in Example 3. The raw material composition of Comparative Example 8 is shown in Table 11.

[0089] Table 11 Raw material ratio of Comparative Example 8

[0090] The performance of Examples 1-3 and Comparative Examples 1-8 was tested, and the results are shown in Table 12. Table 12 Performance of Examples 1-3 and Comparative Examples 1-8

[0091] Table 12 shows that Examples 1-3 achieved significant performance improvements through careful material selection and optimized production processes, and all values ​​within the test range exhibited excellent results.

[0092] A comparison between Example 1 and Example 3 shows that the amount of 10-15 nanometer silica added in Example 1 is nearly twice the amount of 8-10 nanometer silica added. This results in a crystal structure with larger pores. Therefore, under the same conditions as Example 3, the neutral salt spray resistance of Example 1 is worse than that of Example 3.

[0093] A comparison of Examples 2 and 3 shows that increasing the amount of potassium silicate improves resistance to neutral salt spray. This is because salt spray corrosion is mainly related to chloride ions (Cl). - This is related to the permeability. In corrosive environments, the oxide film or passivation layer on the metal surface will be affected by Cl. - Damage, leading to localized corrosion. K + With Li + In comparison, K + It has a relatively large size (0.152 nm), similar to Cl. - The interaction between them is relatively weak, therefore they do not easily form soluble salts in the electrolyte, thus reducing the amount of Cl. - The erosion effect on metal surfaces can form a more stable interface layer on the material surface, hindering the formation of Cl. - Infiltration. Li + It has a small ionic radius (0.076) and readily reacts with Cl. - A soluble salt, LiCl, is formed. The concentration of potassium ions is set to be twice that of lithium ions, utilizing K... + With Cl - Its bonding ability is relatively weak, and it can bind with Cl on the material surface. - Competing for adsorption sites, thereby reducing Cl- This increases the adsorption capacity, reduces the risk of corrosion, and improves resistance to neutral salt spray.

[0094] Comparative Example 1 shows that using 8-10 nm and 10-15 nm silica in combination significantly enhances the adaptability of the nano silica solution in highly alkaline environments, while also effectively improving its water resistance and acid resistance.

[0095] Comparative Example 2 shows that the addition of lithium silicate (modulus between 3.0 and 3.5) can significantly improve the water resistance of the coating.

[0096] Comparative Example 3 shows that epoxy silane coupling agents have stronger adhesive power than amino silane coupling agents, and the hydroxyl ions contained therein are very beneficial to improving adhesion.

[0097] Comparative Example 4 shows that a dispersion time of 130 minutes can fully utilize the excellent properties of the inorganic material itself.

[0098] Comparative Example 5 demonstrates the significant impact of temperature on the properties of inorganic nano-silicate composite liquids.

[0099] Comparative Example 6 shows that using high-modulus potassium silicate (modulus between 3.5 and 4.0) can impart superior water resistance and chemical resistance to the composite liquid.

[0100] Comparative Example 7 shows that using silica solution smaller than 8 nanometers has a negative impact on the storage stability of inorganic nano-silicate composite liquid.

[0101] Comparative Example 8 shows that using a silica solution with a diameter greater than 15 nanometers is detrimental to the salt spray resistance and corrosion resistance of the inorganic nano-silicate composite solution.

[0102] Therefore, in Examples 4-6, the inorganic nano-silicate composite liquid prepared in Example 3 was allowed to stand for 24 hours before being used to prepare an aqueous acrylate dispersion. The specific preparation methods for Examples 4-6 are as follows: A pH adjuster was added dropwise to the aqueous acrylate at room temperature to adjust the pH to 10.5-11.5, and then the mixture was dispersed at 600 rpm for 30 minutes to obtain a first mixture; an epoxy silane coupling agent was slowly added dropwise to the first mixture, and the mixture was dispersed at 600 rpm at room temperature for 30 minutes to obtain a second mixture; the inorganic nano-silicate dispersion was slowly added to the second mixture, and the mixture was dispersed at 600 rpm at room temperature for 10 minutes, then the temperature was raised to 80°C, and the mixture was dispersed at 600 rpm for 130 minutes to obtain the aqueous acrylate dispersion.

[0103] Example 4 The raw material composition of Example 4 is shown in Table 13.

[0104] Table 13 Raw material ratios for Example 4

[0105] Example 5 The raw material composition of Example 5 is shown in Table 14.

[0106] Table 14 Raw material ratios for Example 5

[0107] Example 6 The raw material composition of Example 6 is shown in Table 15.

[0108] Table 15 Raw material ratios for Example 6

[0109] The performance of the aqueous acrylate dispersions prepared in Examples 4-6 was tested. The results showed that the aqueous acrylate dispersions exhibited good storage stability within the above calibration range, and did not show demulsification or stratification even after long-term exposure to environments ranging from -5°C to 50°C; nor did they exhibit delamination or cracking. The aqueous acrylate dispersions themselves can provide coatings with good corrosion resistance, flame retardancy, and flash rust prevention, and also help to enhance adhesion.

[0110] Examples 7-9 are examples of preparing inorganic composite water-based metal anti-corrosion coatings. The specific preparation methods of Examples 7-9 are as follows: The raw materials of the inorganic composite water-based metal anti-corrosion coating are added to the reaction vessel in sequence. Under normal temperature and pressure, the stirring speed is slowly increased to 800 rpm, and the stirring is continued for 80 minutes until uniform, to obtain an inorganic nano-composite water-based metal anti-corrosion coating with a pH value of 10.8-11.3.

[0111] Example 7 The raw material composition of Example 7 is shown in Table 16.

[0112] Table 16 Raw material ratios for Example 7

[0113] Example 8 The raw material composition of Example 8 is shown in Table 17.

[0114] Table 17 Raw material ratios for Example 8

[0115] Example 9 The raw material composition of Example 9 is shown in Table 18.

[0116] Table 18 Raw material ratios for Example 9

[0117] Comparative Example 9 The difference between Comparative Example 9 and Example 9 is that the aqueous acrylate dispersion was replaced with an acrylic emulsion for metals (BASF 8977), otherwise it is the same as Example 9.

[0118] Comparative Example 10 The difference from Example 9 is that in Comparative Example 10, the aqueous acrylate dispersion was replaced with a mixture of 60% acrylic emulsion for metals (BASF 8977) and 40% potassium silicate, while the rest was the same as in Example 9.

[0119] Comparative Example 11 The difference from Example 9 is that in Comparative Example 11, the aqueous acrylate dispersion was replaced with a mixture of 60% acrylic emulsion for metals (BASF 8977) and 40% silica sol, while the rest was the same as in Example 9.

[0120] Comparative Example 12 The difference from Example 9 is that Comparative Example 12 replaces the aqueous acrylate dispersion with a mixture of 60% acrylic emulsion for metals (BASF 8977), 10% potassium silicate, and 30% silica sol; otherwise, it is the same as Example 9.

[0121] The performance of Examples 7-9 and Comparative Examples 9-12 was tested, and the results are shown in Table 19. Table 19 Performance of Examples 7-9 and Comparative Examples 9-12

[0122] It should be understood that, after the above performance tests, including water resistance, acid resistance, alkali resistance, oil resistance, continuous condensation, and salt spray resistance, the product should not rust, blister, crack, or peel.

[0123] Examples 7-9 exhibit significant advantages over Comparative Examples 9-12 in terms of adhesion, flame retardancy, chemical resistance, and weather resistance. This invention utilizes silica, potassium silicate, and lithium silicate, hydrolyzed and grafted using an epoxy silane coupling agent. After standing for 24 hours, it is grafted with water-based acrylate at 80°C to obtain a water-based acrylate dispersion. This results in an inorganic nanocomposite water-based metal anti-corrosion coating with excellent adhesion, flame retardancy, chemical resistance, and weather resistance, suitable for various industrial anti-corrosion applications and showing promising application prospects. This inorganic nanocomposite water-based metal anti-corrosion coating, with its unique performance advantages, has become a leader in the field of industrial anti-corrosion. This coating not only adapts to various complex and harsh industrial environments but also improves anti-corrosion effects while being environmentally friendly and energy-saving, providing a novel solution for various industrial anti-corrosion applications. In many industries such as chemical, petroleum, power, and transportation, metal equipment is exposed to corrosive environments for extended periods, and traditional anti-corrosion methods often fail to meet the requirements for long-term stable operation. The coating of this invention, through the application of nanotechnology, effectively improves the density and adhesion of the coating, enabling a tough protective film to be formed on the metal surface, thereby significantly extending the service life of the equipment.

[0124] The above embodiments of the present invention are merely examples for clearly illustrating the technical solutions of the present invention, and are not intended to limit the specific implementation of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the claims of the present invention should be included within the protection scope of the claims of the present invention.

Claims

1. An inorganic composite water-based metal anti-corrosion coating, characterized in that, The inorganic composite water-based metal anti-corrosion coating is prepared using the following raw materials in weight percentages: 50-70% water-based acrylic dispersion, 4-6% coloring pigment, 15-22% filler, 0.5-1.5% defoamer, 0.4-0.6% wetting and dispersing agent, 0.4-0.6% leveling agent, 2-4% film-forming aid, appropriate amount of pH adjuster, and the remainder is solvent. The pH of the inorganic composite water-based metal anti-corrosion coating is 10.5-11.

5.

2. The inorganic composite water-based metal anti-corrosion coating according to claim 1, characterized in that, The aqueous acrylate dispersion is prepared from the following raw materials in weight percentages: 60% aqueous acrylate, 38% inorganic nano-silicate dispersion, 1% pH adjuster and 1% epoxy silane coupling agent.

3. The inorganic composite water-based metal anti-corrosion coating according to claim 2, characterized in that, The method for preparing the aqueous acrylate dispersion includes: After adjusting the pH value to 10.5~11.5 by adding a pH adjuster to the aqueous acrylate at room temperature, the mixture is dispersed at 600 rpm for 30 minutes to obtain the first mixture. An epoxy silane coupling agent was added dropwise to the first mixture and dispersed at 600 rpm at room temperature for 30 minutes to obtain the second mixture. Inorganic nano-silicate dispersion was added to the second mixture and dispersed at 600 rpm at room temperature for 10 minutes. Then, the temperature was raised to 80°C and dispersed at 600 rpm for 130 minutes to obtain the aqueous acrylate dispersion.

4. The inorganic composite water-based metal anti-corrosion coating according to claim 2, characterized in that, The inorganic nano-silicate dispersion is prepared from the following raw materials in weight percentages: 39% first nano-silica solution with a silica particle size of 8-10 nanometers, 38% second nano-silica solution with a silica particle size of 10-15 nanometers, 15% potassium silicate, 7% lithium silicate, and 1% epoxy silane coupling agent.

5. The inorganic composite water-based metal anti-corrosion coating according to claim 4, characterized in that: The modulus of the potassium silicate is 3.5 to 4.0, and the modulus of the lithium silicate is 3.0 to 3.

5.

6. The inorganic composite water-based metal anti-corrosion coating according to claim 4, characterized in that, The preparation method of the inorganic nano-silicate dispersion includes: The first nano-silica solution and the second nano-silica solution were mixed at room temperature and dispersed at 400 rpm to obtain a third mixture. At room temperature, pH adjuster was added dropwise to the third mixture to adjust the pH value to 11.2 to 12.

8. Potassium silicate and lithium silicate were then added and dispersed for 30 minutes to obtain the fourth mixture. After adding epoxy silane coupling agent dropwise to the fourth mixture, disperse it at 550 to 680 rpm for 8 to 14 minutes, then heat it to 60 to 72°C, disperse it at 550 to 680 rpm for 115 to 145 minutes, and let it stand for 24 hours to obtain the inorganic nano silicate dispersion.

7. The inorganic composite water-based metal anti-corrosion coating according to claim 1, characterized in that, The filler includes at least one of the following: calcium carbonate, barium sulfate, and calcined kaolin.

8. The inorganic composite water-based metal anti-corrosion coating according to claim 1, characterized in that: The particle size of the filler is 800~1500nm.

9. The inorganic composite water-based metal anti-corrosion coating according to claim 1, characterized in that, The defoamer is BASF 2410, the wetting and dispersing agent is BASF 4140AS, the leveling agent is BYK 333, the film-forming aid is alcohol ester-12, the pH adjuster is AMP95, and the solvent is water.

10. A method for preparing an inorganic composite water-based metal anti-corrosion coating, characterized in that, include: Weigh the raw materials of the inorganic composite water-based metal anti-corrosion coating as described in claim 1; The raw materials for the inorganic composite water-based metal anti-corrosion coating are added to a reaction vessel and stirred at 800 rpm for 80 minutes at room temperature and pressure to obtain the inorganic composite water-based metal anti-corrosion coating with a pH value of 10.8~11.3.

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