A pure inorganic water-based zinc-aluminum coating, a preparation method and applications thereof

Abstract

The application relates to the paint technology field, in particular to a pure inorganic water-based zinc-aluminum paint, a preparation method and application. The pure inorganic water-based zinc-aluminum paint comprises modified ultra-fine flaky zinc-aluminum powder and modified inorganic salt compound complexing agents, wherein the modified ultra-fine flaky zinc-aluminum powder comprises flaky zinc-aluminum powder, titanium dioxide, fumed silica and boron nitride; the modified inorganic salt compound complexing agents comprise silicate, a stabilizer, a water-repellent agent and distilled water; the modified ultra-fine flaky zinc-aluminum powder and the modified inorganic salt compound complexing agents are uniformly mixed according to a weight ratio of 1:2.4, so that the paint is obtained. The application solves the problems that the corrosion prevention technology is not environment-friendly, the adhesion is weak, the construction process is complex, and the service life of the paint is short.

Description

Technical Field

[0001] This invention relates to the field of coating technology, specifically to a pure inorganic water-based zinc-aluminum coating, its preparation method, and its application. Background Technology

[0002] The most common anti-corrosion technologies currently include cold galvanizing, hot-dip galvanizing, epoxy zinc enrichment, and Dacromet coating.

[0003] Cold galvanizing involves a zinc coating of only 1-3 μm, and the manufacturing process is not environmentally friendly. The product is not repairable, and damage to the anti-corrosion layer after welding cannot be repaired.

[0004] Hot-dip galvanizing: The thickness of the coating on the metal surface is difficult to control, and the metal is prone to hydrogen embrittlement. The metal immersion coating process is not environmentally friendly, and the product is not repairable.

[0005] Epoxy zinc-rich coatings: Applying them on-site is not environmentally friendly. They can withstand salt spray tests for 80-120 hours, are prone to corrosion and peeling in coastal environments, and may cause secondary environmental pollution during the application process. They are also not resistant to high temperatures.

[0006] Dacromet coating: The Dacromet coating process is relatively complex. The theoretical sintering temperature is 320℃, but the actual temperature is 370℃. The baking time is 40 to 60 minutes. Due to process limitations, it is currently mainly used in automobile manufacturing and small part processing in other fields, and its application scope is relatively narrow.

[0007] In summary, there are currently no mature, purely inorganic water-based anti-corrosion coatings available for engineering construction. Organic coatings emit volatile organic compounds that cause secondary environmental pollution and pose certain health risks to those exposed to them. Furthermore, currently available water-based coatings also contain organic components, generating volatile organic compounds during application, causing secondary pollution. More importantly, due to limitations in their mechanism of action, these water-based coatings have insufficient adhesion to metal surfaces, poor thickness resistance, and are prone to film peeling, resulting in a short service life. Summary of the Invention

[0008] In order to solve the problems in related technologies, this invention provides a pure inorganic water-based zinc-aluminum coating, its preparation method, and its application, which solves the problems of insufficient environmental protection of anti-corrosion technology, weak adhesion, complex construction process, and short service life of coating.

[0009] To solve the above problems, the following technical solutions are provided:

[0010] This invention provides a pure inorganic water-based zinc-aluminum coating, characterized in that it comprises modified ultrafine flake zinc-aluminum powder and modified inorganic salt complexing agent.

[0011] The modified ultrafine flake zinc-aluminum powder includes the following raw materials in parts by weight:

[0012] The weight percentages of the flaky zinc-aluminum powder are 25–35 parts, the weight percentages of titanium dioxide are 0.5–2 parts, the weight percentages of fumed silica are 0.1–0.5 parts, and the weight percentages of boron nitride are 0.1–0.5 parts.

[0013] The modified inorganic salt complexing agent comprises the following raw materials in parts by weight:

[0014] The silicate is 40-50 parts by weight, the stabilizer is 20-30 parts by weight, the hydrophobic agent is 0.1-1 parts by weight, and the distilled water is 0.1-1 parts by weight.

[0015] Through the above scheme, this invention rationally combines raw material components with different functions to achieve the best synergistic effect among different raw material components. Adding flake-shaped zinc-aluminum powder improves the coating's corrosion resistance and also enhances its wear resistance, chemical corrosion resistance, and high-temperature resistance. Adding titanium dioxide increases the coating's hardness and the dispersibility of the flake-shaped zinc-aluminum powder. Adding fumed silica significantly improves the coating's hardness, wear resistance, and stability, extending its service life, while also ensuring good fluidity during application, guaranteeing the coating's thickness and uniformity. Adding boron nitride, with its high thermal conductivity, low coefficient of friction, and good chemical stability, improves the coating's thermal conductivity, enhances lubricity and hardness, and extends its service life. Adding silicates improves the coating's water resistance and stability. Adding stabilizers increases the coating's stability and prevents gelation of the complexing agent after a certain period. Adding hydrophobic agents increases the coating's hydrophobicity and maintains its adhesion.

[0016] The silicate is any two or more combinations of potassium silicate, sodium silicate and aluminum silicate.

[0017] The stabilizer is a silicate stabilizer.

[0018] The hydrophobic agent is sodium methylsilicate.

[0019] A method for preparing a pure inorganic water-based zinc-aluminum coating includes the following steps:

[0020] S1: Preparation of modified ultrafine flake zinc-aluminum powder: Weigh flake zinc-aluminum powder, titanium dioxide, fumed silica and boron nitride and add them to a ball mill. Under nitrogen protection, grind and mix to ensure uniform dispersion, and you will get modified ultrafine flake zinc-aluminum powder.

[0021] S2: Preparation of modified inorganic salt complexing agent: Weigh silicate and hydrophobic agent and put them into an atmospheric pressure reaction synthesis device for compounding. Add distilled water for dilution, then add stabilizer and stir. After stirring evenly, cool to obtain modified inorganic salt complexing agent.

[0022] S3: Take 1 part by weight of the ultrafine flake zinc-aluminum powder prepared by S1 and 2.4 parts by weight of the modified inorganic salt complexing agent prepared by S2. Add 1 part of the ultrafine flake zinc-aluminum powder and 0.8 parts of the modified inorganic salt complexing agent to the mixing container for the first stirring. Then add 1.6 parts of the modified inorganic salt complexing agent to the mixing container in two batches for the second stirring to obtain the coating.

[0023] The above-described method for preparing coatings involves simple operation steps. By rationally arranging the order of addition of different raw materials, temperature, and stirring conditions, the final coating exhibits excellent high-temperature resistance and wear resistance, as well as strong adhesion to metal workpieces. Furthermore, the coating emits no volatile organic compounds during use, making it safe and environmentally friendly, thus avoiding pollution.

[0024] The mixing time for grinding and mixing in S1 is 90–120 min, and the mixing temperature is 50–60 °C.

[0025] The mixing temperature in S2 is 70–80℃, and the stirring time is 40–90 min; the dilution temperature in S2 is 80℃, and the stirring time is 20–30 min; the stirring temperature in S2 is 80℃, and the stirring time is 30–40 min.

[0026] The first stirring time in S3 is 20-30 minutes, and the stirring speed is 30-50 r / min; the second stirring time is 60-90 minutes, and the stirring speed is 60-80 r / min.

[0027] First, remove rust from the surface of the metal workpiece. Then, add the paint to the spray bottle, start compressed air, and spray the paint onto the surface of the metal workpiece. After an interval of 30 minutes, perform a second spray. Place the sprayed metal workpiece in an oven to bake, and the coating will be obtained.

[0028] The above solution provides a simple application process for the coating and can be used in conjunction with conventional oil-based and water-based coatings. It enables the application of zinc-rich coatings to the metal surfaces of equipment and structural components used in large-scale engineering projects, thereby solving the problem of low corrosion resistance of workpieces or equipment.

[0029] The baking temperature is 125-135℃, and the baking time is 30 minutes.

[0030] The above solution has the following advantages:

[0031] The preparation method of this invention involves simple operation steps and reasonable arrangement of the order of addition, temperature, and stirring conditions of different raw materials, resulting in a coating with good high-temperature resistance and wear resistance, as well as strong adhesion to metal workpieces. This coating emits no volatile organic compounds during use, making it safe and environmentally friendly. The addition of flake zinc-aluminum powder improves the anti-corrosion performance of the coating, enhancing the safety of anti-corrosion construction for enterprises. Furthermore, the application process of this coating is simple and it can be used in conjunction with conventional oil-based and water-based coatings. Detailed Implementation

[0032] The technical solutions of the present invention will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. 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.

[0033] This application describes a pure inorganic water-based zinc-aluminum coating, its preparation method, and its application.

[0034] The silicate stabilizer used in Examples 1-3 and Comparative Examples 1-2 was GSYWDJ-5.

[0035] Step 1: Preparation of raw materials of different weights

[0036] Example 1: A pure inorganic water-based zinc-aluminum coating, composed of the following raw materials in parts by weight:

[0037] The modified ultrafine flake zinc-aluminum powder includes the following raw materials in parts by weight:

[0038] The weight percentages of the flaky zinc-aluminum powder are 25 parts, the weight percentages of titanium dioxide are 0.5 parts, the weight percentages of fumed silica are 0.1 parts, and the weight percentages of boron nitride are 0.1 parts.

[0039] The modified inorganic salt complexing agent comprises the following raw materials in parts by weight:

[0040] The weight percentages of potassium silicate and sodium silicate are 40 parts, the weight percentages of silicate stabilizer are 20 parts, the weight percentages of sodium methylsilicate are 0.1 parts, and the weight percentages of distilled water are 0.1 parts.

[0041] Example 2: A pure inorganic water-based zinc-aluminum coating, composed of the following raw materials in parts by weight:

[0042] The modified ultrafine flake zinc-aluminum powder includes the following raw materials in parts by weight:

[0043] The weight percentages of the flaky zinc-aluminum powder are 30 parts, the weight percentages of titanium dioxide are 1 part, the weight percentages of fumed silica are 0.3 parts, and the weight percentages of boron nitride are 0.3 parts.

[0044] The modified inorganic salt complexing agent comprises the following raw materials in parts by weight:

[0045] The weight percentages of sodium silicate and aluminum silicate are 45 parts, the weight percentages of silicate stabilizer are 25 parts, the weight percentages of sodium methylsilicate are 0.5 parts, and the weight percentages of distilled water are 0.5 parts.

[0046] Example 3: A pure inorganic water-based zinc-aluminum coating, composed of the following raw materials in parts by weight:

[0047] The modified ultrafine flake zinc-aluminum powder includes the following raw materials in parts by weight:

[0048] The weight percentages of the flaky zinc-aluminum powder are 35 parts, the weight percentages of titanium dioxide are 2 parts, the weight percentages of fumed silica are 0.5 parts, and the weight percentages of boron nitride are 0.5 parts.

[0049] The modified inorganic salt complexing agent comprises the following raw materials in parts by weight:

[0050] The weight percentages of potassium silicate and aluminum silicate are 50 parts, the weight percentages of silicate stabilizer are 30 parts, the weight percentage of sodium methylsilicate is 1 part, and the weight percentage of distilled water is 1 part.

[0051] Comparative Example 1: A pure inorganic water-based zinc-aluminum coating, composed of the following raw materials in parts by weight:

[0052] The modified ultrafine flake zinc-aluminum powder includes the following raw materials in parts by weight:

[0053] The weight percentages of the flaky zinc-aluminum powder are 20 parts, the weight percentages of titanium dioxide are 0.2 parts, the weight percentages of fumed silica are 0.05 parts, and the weight percentages of boron nitride are 0.05 parts.

[0054] The modified inorganic salt complexing agent comprises the following raw materials in parts by weight:

[0055] The weight percentages of sodium silicate and aluminum silicate are 20 parts, the weight percentages of silicate stabilizer are 10 parts, the weight percentages of sodium methylsilicate are 0.05 parts, and the weight percentages of distilled water are 0.05 parts.

[0056] Comparative Example 2: A pure inorganic water-based zinc-aluminum coating, composed of the following raw materials in parts by weight:

[0057] The modified ultrafine flake zinc-aluminum powder includes the following raw materials in parts by weight:

[0058] The weight percentages of the flaky zinc-aluminum powder are 40 parts, the weight percentages of titanium dioxide are 3 parts, the weight percentages of fumed silica are 1 part, and the weight percentages of boron nitride are 1 part.

[0059] The modified inorganic salt complexing agent comprises the following raw materials in parts by weight:

[0060] The weight percentages of sodium silicate and aluminum silicate are 60 parts, the weight percentages of silicate stabilizer are 40 parts, the weight percentages of sodium methylsilicate are 2 parts, and the weight percentages of distilled water are 2 parts.

[0061] Step 2: A method for preparing a pure inorganic water-based zinc-aluminum coating, comprising the following steps:

[0062] S1. Preparation: Weigh each raw material according to the above formula ratio and set aside;

[0063] S2. First, add the flake-shaped zinc-aluminum powder, titanium dioxide, fumed silica and boron nitride into a ball mill, and grind and mix them under nitrogen protection for 90 to 120 minutes at a mixing temperature of 50 to 60°C to ensure uniform dispersion, and you will get the modified ultrafine flake-shaped zinc-aluminum powder.

[0064] S3. Place silicate and hydrophobic agent into an atmospheric pressure reaction synthesis device, heat to 70-80℃, stir for 40-90 minutes, compound, add distilled water for dilution, maintain the temperature at 80℃, stir for 20-30 minutes, then add stabilizer and stir, maintain the temperature at 80℃, stir for 30-40 minutes, after stirring evenly, cool to obtain modified inorganic salt compound complexing agent;

[0065] S4. Take 1 part by weight of the ultrafine flake zinc-aluminum powder prepared by S1 and 2.4 parts by weight of the modified inorganic salt complexing agent prepared by S2. First, add 1 part of the ultrafine flake zinc-aluminum powder and 0.8 parts of the modified inorganic salt complexing agent to the mixing container and stir at low speed for 20-30 minutes at a stirring speed of 30-50 r / min. Then, add 1.6 parts of the modified inorganic salt complexing agent to the mixing container in two batches and stir for 60-90 minutes at a stirring speed of 60-80 r / min to obtain the coating.

[0066] Step 3: Application of a pure inorganic water-based zinc-aluminum coating

[0067] First, remove rust from the surface of the metal workpiece. Then, add the paint to the spray bottle, start compressed air, and spray the paint onto the surface of the metal workpiece. After a 30-minute interval, spray a second time. Place the sprayed metal workpiece in an oven and bake at 125-135℃ for 30 minutes to obtain a coating. The thickness of this coating is 15-25μm, and it can withstand neutral salt spray for more than 1000 hours and high temperature for up to 400℃.

[0068] Step 4: Experimental Data

[0069]

[0070] Experimental conclusion:

[0071] The results show that the raw materials used to prepare the coatings in Examples 1-3 and Comparative Examples 1-2 are all inorganic materials, and the production process, coating process, and coating will not cause environmental pollution. The VOC of the products is lower than 2PPM, and they can be widely used in metal corrosion protection in various fields. However, compared with Examples 1-3, Comparative Examples 1-2 have significant differences in coating thickness and neutral salt spray performance. Examples 1-3 have higher coating thickness, neutral salt spray performance, and high temperature resistance, and are cost-effective. From the experimental data, Example 2 has the best data, with superior coating thickness, neutral salt spray performance, and high temperature resistance.

[0072] Compared with the electroplated zinc coating, the coating of Example 2 is much thinner. The volatile organic compound emissions of the electroplated zinc coating, hot-dip zinc coating, and Dacromet coating are all higher than those of Example 2. The water-based environmental protection of the electroplated zinc coating, hot-dip zinc coating, Dacromet coating, and Dacromet coating is poor, and the cost performance is generally average.

[0073] The coating formed by the coating is an inorganic coating, which can withstand high temperatures of over 400℃ for long-term use, and its high temperature resistance is far greater than that of conventional organic coatings. After the coating is kept at 400℃ in a high-temperature furnace for 1 hour, the color of the paint film does not change at all, the surface is intact, and there are no bubbles or cracks.

[0074] The coating thickness is 15-25μm, the coating area per unit weight is large, the cost performance is high, the salt spray resistance time in the neutral salt spray test is greater than 1000 hours, and the corrosion resistance is far greater than that of epoxy zinc-rich coatings.

[0075] The raw materials required for the production of this coating are all conventional and readily available on the market. Compared with coatings for the same purpose, the coating produced by this invention is more environmentally friendly, has good high temperature resistance and wear resistance, and can be widely used in metal corrosion protection in various fields. It has superior cost and performance advantages.

Claims

1. A process for the preparation of a pure inorganic aqueous zinc aluminum coating, characterized in that, The method comprises the following steps: S1: preparation of modified ultra-fine flaky zinc-aluminum powder: flaky zinc-aluminum powder, titanium dioxide, fumed silica and boron nitride are weighed and added into a ball mill, grinding and mixing are carried out under nitrogen protection to ensure uniform dispersion, and the modified ultra-fine flaky zinc-aluminum powder is obtained; S2: preparation of modified inorganic salt complexing agent: silicate and water-repellent agent are weighed and put into an atmospheric pressure reaction synthesis device, compounding is carried out, distilled water is added for dilution, a stabilizer is added and stirred, and after uniform stirring, the modified inorganic salt complexing agent is obtained after cooling; S3: 1 part of the ultra-fine flaky zinc-aluminum powder prepared in S1 and 2.4 parts of the modified inorganic salt complexing agent prepared in S2 are taken, 1 part of the ultra-fine flaky zinc-aluminum powder and 0.8 part of the modified inorganic salt complexing agent are added into a stirring container for first stirring, and 1.6 parts of the modified inorganic salt complexing agent is added into the stirring container in two times for second stirring, and the paint is obtained; The paint comprises the modified ultra-fine flaky zinc-aluminum powder and the modified inorganic salt complexing agent, The modified ultra-fine flaky zinc-aluminum powder comprises the following raw materials in parts by weight: The flaky zinc-aluminum powder is 25-35 parts by weight, the titanium dioxide is 0.5-2 parts by weight, the fumed silica is 0.1-0.5 parts by weight, and the boron nitride is 0.1-0.5 parts by weight; The modified inorganic salt complexing agent comprises the following raw materials in parts by weight: The silicate is 40-50 parts by weight, the stabilizer is 20-30 parts by weight, the water-repellent agent is 0.1-1 parts by weight, and the distilled water is 0.1-1 parts by weight; The silicate is potassium silicate, sodium silicate and aluminum silicate, or any two or more combinations thereof.

2. A process for the preparation of a pure inorganic aqueous zinc aluminum coating as claimed in claim 1, characterized in that, The stabilizer is a silicate stabilizer.

3. A process for the preparation of a pure inorganic aqueous zinc aluminum coating as claimed in claim 1, wherein, The water-repellent agent is sodium methyl silicate.

4. A process for the preparation of a pure inorganic aqueous zinc aluminum coating as claimed in claim 1, wherein, The mixing time of grinding and mixing in S1 is 90-120 min, and the mixing temperature is 50-60 DEG C.

5. A process for the preparation of a pure inorganic aqueous zinc aluminum coating as claimed in claim 1, wherein, The compounding temperature in S2 is 70-80 DEG C, and the stirring time is 40-90 min; the dilution temperature in S2 is 80 DEG C, and the stirring time is 20-30 min; the stirring temperature in S2 is 80 DEG C, and the stirring time is 30-40 min.

6. A process for the preparation of a pure inorganic aqueous zinc aluminum coating as claimed in claim 1, wherein, The first stirring time in S3 is 20-30 min, and the stirring speed is 30-50 r / min; the second stirring time is 60-90 min, and the stirring speed is 60-80 r / min.

7. Use of a purely inorganic aqueous zinc aluminum coating, characterized in that First, the surface of the metal workpiece is derusted, then the paint is added into a spray bottle, compressed air is started, and the metal workpiece surface is sprayed with the paint, after 30 min, secondary spraying is carried out, and the sprayed metal workpiece is placed in an oven for baking, and the coating is obtained.

8. Use of a purely inorganic aqueous zinc-aluminum coating according to claim 7, characterized in that The baking temperature is 125-135 DEG C, and the baking time is 30 min.

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