Cathode protection, self-repairing and self-cleaning anticorrosive paint for water-based over-rust coating of steel structure

Abstract

The invention discloses a steel structure aqueous on-rust coating cathodic protection, self-repairing and self-cleaning anticorrosive paint, which comprises a component A and a component B. The component A comprises deionized water, aqueous fluorocarbon acrylic resin, tannic acid, nanometer aluminum triphosphate and a nanometer conductive polymer. The component B is prepared from ZnAl-based alloy powder, nano rutile type titanium dioxide and nano tricalcium aluminate. The coating disclosed by the invention adopts water as a solvent, does not contain volatile organic compounds, and is beneficial to environmental protection and health protection; the rust transforming agent in the paint can stabilize rust, prevent rust and coat with rust; the nano conductive polymer material enables the coating anticorrosive coating to have a self-repairing function; the ZnAl-based alloy powder not only can effectively play a long-term cathode protection role, but also can improve the shielding protection role of the coating; the nano rutile type titanium dioxide has the functions of self-cleaning and prolonging the anti-corrosion service life of the coating. The coating disclosed by the invention can provide safe, long-acting and convenient-to-construct anti-corrosion protection for a steel structure.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of steel structure corrosion protection, and particularly relates to a steel structure water-based rusted coating cathodic protection and self-repairing self-cleaning corrosion protection paint. BACKGROUND

[0002] Steel structure has the advantages of good toughness, convenient manufacturing and short construction period, and is more and more widely used in the fields of construction and engineering. However, the easy corrosion of the steel structure brings huge losses to the national economy. In June 2015, the Chinese Academy of Sciences launched the major consulting project of "China's corrosion status and control strategy research", and the data shows that the accidents caused by various types of corrosion are shocking and seriously affect the development of social economy. The problem of corrosion protection of major equipment and materials should be included in the overall development strategy of the country. If effective corrosion protection measures are taken, 25% to 40% of the corrosion loss can be avoided.

[0003] The steel structure coating corrosion protection paint is one of the relatively economic and reasonable corrosion protection measures. However, many complex steel structures such as buildings, bridges and towers can only use manual or light electric tools for rust removal and other surface treatment during construction or maintenance due to structural limitations, resulting in the residual of corrosion products such as iron rust on the surface of the steel structure, which is difficult to meet the standard of Sa2.5 level or above. At the same time, based on environmental protection and health reasons, the rusted coating paint is developing towards water-based, high performance, convenient construction and environmental protection.

[0004] The Chinese invention patent with the publication number CN105017926A (a rusted coating nano composite zinc-containing corrosion protection paint for steel structure) discloses a rusted coating nano composite zinc-containing corrosion protection paint for steel structure. The raw materials of the paint mainly adopt two components, the A component includes epoxy resin, nano composite anti-rust component, reduced zinc powder, butyl ether, dimethylbenzene, butanol, organic bentonite, mica powder and toughening agent, and the B component includes polyamide, dimethylbenzene and butanol. The corrosion protection mechanism of the paint includes shielding effect and Zn cathodic protection effect. The paint uses a large amount of organic solvents, which does not meet the current green environmental protection requirements.

[0005] The Chinese invention patent with the publication number CN101104764A (a heavy corrosion protection paint for steel and its preparation method) discloses a heavy corrosion protection paint for steel and its preparation method. The raw materials of the paint mainly adopt silane coupling agent coated zinc powder, fluorocarbon modified acrylic resin and / or epoxy resin, anti-settling slurry, nano phosphate, additives and organic solvents. The paint mainly prevents steel corrosion through Zn cathodic protection effect. However, the corrosion products of Zn are slightly soluble in water, resulting in a high corrosion rate of the Zn coating and a fast consumption of the coating. The paint uses organic solvents, which does not meet the current green environmental protection requirements.

[0006] A Chinese invention patent with publication number CN105925030A (a rust-bearing anticorrosive coating for steel and its preparation method) discloses a rust-bearing anticorrosive coating for steel and its preparation method, the coating raw materials of which mainly adopt pure water, polyvinyl chloride resin, silicone rubber, acetone, vermiculite powder, kaolin, white oil, glycerol, benzotriazole, barium petroleum sulfonate, vinyl acetate, butyl acrylate, acrylic acid and potassium persulfate. A Chinese invention patent with publication number CN102391732A (an aqueous emulsion environment-friendly rust-bearing anticorrosive coating for steel) discloses an aqueous emulsion environment-friendly rust-bearing anticorrosive coating for steel, the coating raw materials of which mainly adopt a styrene-acrylic emulsion and use tannic acid as an iron rust conversion agent. A Chinese invention patent with publication number CN102993846B (a water-based rust surface anticorrosive coating for steel structure and its preparation method) discloses a water-based rust surface anticorrosive coating for steel structure and its preparation method, the coating raw materials of which mainly adopt an iron rust conversion agent, an epoxy emulsion, a cationic styrene-acrylic emulsion, a penetrant, ethylene glycol ether, a dispersion stabilizer and deionized water. A Chinese invention patent with publication number CN100554348C (a water-based rust-bearing anticorrosive coating for steel structure and its preparation method) discloses a water-based rust-bearing anticorrosive coating for steel structure and its preparation method, the coating raw materials of which mainly adopt a styrene-acrylic emulsion, iron oxide, talc powder, phosphoric acid, tannic acid, aluminum hydroxide, zinc oxide, zinc dihydrogen phosphate, potassium dichromate, a film-forming aid, sodium hexametaphosphate, dibutyl phthalate, a defoaming agent and water. A Chinese invention patent with publication number CN101921516B (a water-based anticorrosive transparent coating suitable for steel surface and its preparation method) discloses a water-based anticorrosive transparent coating suitable for steel surface and its preparation method, the coating raw materials of which mainly adopt a water-based film-forming resin, a water-based film-forming aid, a nano-sized filler, a nano-sized anticorrosive pigment, a dispersant, a water-based defoaming agent, a water-based wetting agent, a water-based leveling agent, an iron rust conversion liquid, a surfactant and a balance of deionized water. The anticorrosive mechanism of this kind of water-based rust-bearing coating for steel structure is shielding, which plays an anticorrosive role by shielding the corrosive medium in the environment. Once the coating is damaged, the steel structure substrate at the damaged part will be corroded and expanded, and the coating will lose the anticorrosive effect. SUMMARY

[0007] The technical problem to be solved by the present application is to provide a water-based rust-bearing coating for steel structure with cathodic protection and self-repairing and self-cleaning functions, aiming at the deficiencies of the prior art. The water-based rust-bearing coating for steel structure with cathodic protection and self-repairing and self-cleaning functions has the advantages of safety, environmental protection, rust-bearing coating and the like, has good cathodic protection and shielding protection functions as well as coating self-repairing and self-cleaning functions, and can provide safe, long-acting and convenient anticorrosive protection for steel structure.

[0008] To solve the above technical problems, the technical scheme adopted by the present application is: a kind of steel structure water-based rust coating cathodic protection and self-repairing self-cleaning anticorrosive coating, characterized in that the anticorrosive coating includes component A and component B;Component A includes the following components by weight: 20-30 parts by weight of deionized water, 40-55 parts by weight of water-based fluorocarbon acrylic resin, 2-5 parts by weight of tannic acid, 2-5 parts by weight of nano aluminum tripolyphosphate, and 15-26 parts by weight of nano conductive polymer;Component B includes the following components by weight: 60-90 parts by weight of ZnAl-based alloy powder, 5-25 parts by weight of nano rutile titanium dioxide, and 5-15 parts by weight of nano aluminates.

[0009] The above-mentioned steel structure water-based rust coating cathodic protection and self-repairing self-cleaning anticorrosive coating is characterized in that the water-based fluorocarbon acrylic resin is a blended polymer of tetrafluoroethylene monomer or trifluorochloroethylene monomer and acrylic acid monomer.

[0010] The above-mentioned steel structure water-based rust coating cathodic protection and self-repairing self-cleaning anticorrosive coating is characterized in that the nano conductive polymer is a nano-sized polyaniline, polypyrrole or polythiophene material.

[0011] The above-mentioned steel structure water-based rust coating cathodic protection and self-repairing self-cleaning anticorrosive coating is characterized in that the ZnAl-based alloy powder has a particle size of ≤20 μm.

[0012] The above-mentioned steel structure water-based rust coating cathodic protection and self-repairing self-cleaning anticorrosive coating is characterized in that the ZnAl-based alloy powder has a mass percentage composition of: Zn 43%-82%, Al 12%-55%, and trace amounts of alloying elements such as Mg, Si and B 2%-6%.

[0013] The above-mentioned steel structure water-based rust coating cathodic protection and self-repairing self-cleaning anticorrosive coating is characterized in that the nano aluminates are nano tricalcium aluminate.

[0014] The above-mentioned steel structure water-based rust coating cathodic protection and self-repairing self-cleaning anticorrosive coating is characterized in that the mass ratio of component A to component B is 1:(1-3).

[0015] The weight parts can be grams, kilograms, jin, kilograms, etc.

[0016] Compared with the prior art, the present application has the following advantages:

[0017] 1. The coating of the present application uses water as a solvent and does not contain volatile organic compounds (VOC), which is beneficial to environmental protection and health protection.

[0018] 2、The coating of the present application contains rust conversion agent, which can react with the residual rust on the surface of steel structure to form stable chelate passivation layer and complex, and the conversion product is strongly attached to the surface of steel structure in the form of physical and chemical bonds, thus forming a good insoluble protective film, stabilizing rust and preventing rust, and inhibiting the corrosion process.

[0019] 3、The coating of the present application contains nano-conductive polymer material, which can passivate the surface of steel structure to form a dense oxide film, delay corrosion, and when the oxide film on the surface of steel structure is damaged, the nano-conductive polymer material can also induce the oxide film to gradually repair, so that the coating anticorrosion layer has self-repairing function, and continuously provides corrosion protection for steel structure.

[0020] 4、The coating of the present application contains ZnAl-based alloy powder, and the elements such as Al, Mg, Si and B can not only promote the cathodic protection effect of Zn, but also have the effect of passivating and protecting Zn in the atmosphere and corrosion medium, improve the cathodic protection life, and the corrosion product is dense and insoluble in water, and can fill the micro-pores. The ZnAl-based alloy powder can not only effectively play a long-term cathodic protection effect, but also improve the shielding protection effect of the coating.

[0021] 5、The coating of the present application contains nano-rutile titanium dioxide, which has photocatalytic function, can decompose and adsorb harmful organic and inorganic substances on the coating, and has self-cleaning and prolonging the anticorrosion life of the coating.

[0022] 6、The steel structure water-based rust coating cathodic protection and self-repairing anticorrosion coating of the present application has the advantages of safety, environmental protection, rust coating, etc., has good cathodic protection and shielding protection function, and coating self-repairing and self-cleaning function. It can provide safe, long-acting and convenient construction anticorrosion protection for steel structure.

[0023] The technical solutions of the present application will be further described in detail in combination with the drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is the appearance diagram of rusted SPCC steel plate and rusted SPCC steel plate in Example 1.

[0025] Figure 2 It is the photo before and after the adhesion test of the anticorrosion coating of the rusted SPCC steel plate in Example 1.

[0026] Figure 3 It is the appearance diagram of the plate surface of the anticorrosion coating of Example 1 after 3000h of neutral salt spray test.

[0027] Figure 4 It is the appearance diagram of rusted SPCC steel plate and rusted SPCC steel plate in Example 2.

[0028] Figure 5 Photos of the rusted SPCC steel plate before and after the corrosion coating adhesion test in Example 2.

[0029] Figure 6 Appearance photos of the plate surface of the corrosion coating of Example 2 after 2000h of neutral salt spray test.

[0030] Figure 7 Appearance photos of the rusted SPCC steel plate and the rusted SPCC steel plate in Example 3.

[0031] Figure 8 Photos of the rusted SPCC steel plate before and after the corrosion coating adhesion test in Example 3.

[0032] Figure 9 Appearance photos of the plate surface of the corrosion coating of Example 3 after 2000h of neutral salt spray test. DETAILED DESCRIPTION

[0033] Example 1

[0034] The steel structure waterborne rusted coating cathodic protection and self-repairing self-cleaning corrosion coating of the present example is prepared by stirring and mixing the A component and the B component uniformly at a mass ratio of 1:1; the A component comprises: deionized water 20 parts by weight, a blended polymer waterborne fluorocarbon acrylic resin of tetrafluoroethylene monomer and acrylic monomer 55 parts by weight, tannic acid 5 parts by weight, nano aluminum tripolyphosphate 5 parts by weight, and nano polyaniline 15 parts by weight, and the A component is mixed in a stainless steel container at 600 rpm for 1h until uniform; the B component comprises: ZnAl-based alloy powder 60 parts by weight, nano rutile titanium dioxide 25 parts by weight, and nano tricalcium aluminate 15 parts by weight, wherein the ZnAl-based alloy powder has a particle size of 20μm, and the element content is respectively Zn 82%, Al 12%, and Mg, Si, B, and other trace alloying elements 6%; the B component is mixed in a stainless steel container at 600 rpm for 1h until uniform. Then the A component and the B component are mixed in a stainless steel container at 600 rpm for 1h until uniform at a mass ratio of 1:1, and the corrosion coating is prepared by filtering through a 200 mesh nylon screen under vacuum.

[0035] The corrosion coating is obtained by coating the corrosion coating on the rusted SPCC steel plate using a 300μm coating wire bar, drying in an oven at 60℃ for 2h after coating is completed, and then placing at room temperature 25℃ for 168h. The dry film thickness is about 140μm measured by a thickness gauge. The preparation process of the rusted SPCC steel plate is as follows:

[0036] Step one, first sandblast the SPCC steel plate, and then put it into a salt spray chamber for 2 days to let the substrate surface be covered with rust, as shown in the left side of the figure. Figure 1 ​

[0037] Step two, take out the rusty steel plate, brush and rinse at the same time, then bake at (105±2) ℃ for 1h;

[0038] Step three, manually polish the surface of the steel plate with a steel wire brush to remove loose rust, leaving firmly attached rust, and blow off the surface dust with high-pressure air to obtain a rusty SPCC steel plate, as shown in the right side of the figure. Figure 1

[0039] The adhesion of the corrosion-resistant coating was tested according to the national standard “GB / T9286-2021”, and the before and after photos are shown in Figure 2 , and the coating adhesion is 0 level.

[0040] According to the standard “GB / T1731-2020”, the flexibility of the corrosion-resistant coating is 1mm;

[0041] According to the standard “GB / T1732-2020”, the impact resistance of the corrosion-resistant coating is 50cm;

[0042] The neutral salt spray resistance of the corrosion-resistant coating was tested according to the national standard “GB / T1771-2007”, and the results are shown in Figure 3 , and the coating has individual blistering on the surface at 3000h, and the after-test photo is shown in the figure below. The neutral salt spray resistance of the coating is 3000h.

[0043] Example 2

[0044] The steel structure water-based rusty coating cathodic protection and self-repairing self-cleaning anticorrosive coating of this embodiment is prepared by stirring and mixing the A component and the B component in a mass ratio of 1:2; the A component comprises: deionized water 25 parts by weight, a blended polymer water-based fluorocarbon acrylic resin of tetrafluoroethylene monomer and acrylic monomer 50 parts by weight, tannic acid 4 parts by weight, nano aluminum tripolyphosphate 3 parts by weight, and nano polypyrrole 18 parts by weight. The A component is mixed in a stainless steel container at 600 rpm for 1h until uniform; the B component comprises: ZnAl-based alloy powder 80 parts by weight, nano rutile titanium dioxide 10 parts by weight, and nano tricalcium aluminate 10 parts by weight, wherein the ZnAl-based alloy powder has a particle size of 15μm, and the element contents are Zn 60%, Al 36%, and Mg, Si, B, and other trace alloying elements 4%. The B component is mixed in a stainless steel container at 600 rpm for 1h until uniform. Then the A component and the B component are mixed in a stainless steel container at 600 rpm for 1h until uniform in a mass ratio of 1:2, and filtered through a vacuum 200 mesh nylon screen to obtain the anticorrosive coating.

[0045] ​The anti-corrosion coating was prepared by coating the anti-corrosion coating on the rusted SPCC steel plate with a 300 μm coating rod, drying the coating in an oven at 60 °C for 2 h, and then placing the coating at room temperature (25 °C) for 168 h. The dry film thickness was about 145 μm, which was measured by a thickness gauge. The preparation process of the rusted SPCC steel plate was as follows:

[0046] Step one: first, the SPCC steel plate was sandblasted, and then placed in a salt spray chamber for 2 days to allow the surface of the substrate to be covered with rust, as shown in the left side of the figure. Figure 4

[0047] Step two: the rusted steel plate was taken out, washed with a brush, and then baked at (105±2) °C for 1 h.

[0048] Step three: the rust on the surface of the steel plate was removed by manual polishing with a steel wire brush, and the firmly adhered rust was left. The surface dust was blown away with high-pressure air to obtain the rusted SPCC steel plate, as shown in the right side of the figure. Figure 4

[0049] The adhesion of the anti-corrosion coating was tested according to the national standard GB / T9286-2021, and the before and after photos are shown in the figure. The coating adhesion was 0 level. Figure 5

[0050] According to the standard GB / T1731-2020, the flexibility of the anti-corrosion coating was 1 mm.

[0051] According to the standard GB / T1732-2020, the impact resistance of the anti-corrosion coating was 50 cm.

[0052] The neutral salt spray resistance of the anti-corrosion coating was tested according to the national standard GB / T1771-2007, as shown in the figure. At 2000 h, the plate surface was individually blistered. The after-test photo is shown in the figure. The coating had a neutral salt spray resistance of 2000 h. Figure 6

[0053] Example 3

[0054] ​​​​The water-based rust-coated cathodic protection and self-repairing self-cleaning anti-corrosion coating for steel structures in this embodiment is prepared by stirring and evenly mixing component A and component B in a mass ratio of 1:3; the component A comprises: 30 parts by weight of deionized water, 40 parts by weight of a water-based fluorocarbon acrylic resin of a blended polymer of trifluorochloroethylene monomer and acrylic acid monomer, 2 parts by weight of tannic acid, 2 parts by weight of nano aluminum tripolyphosphate, and 26 parts by weight of nano polythiophene. Component A is mixed in a stainless steel container at 600 rpm for 1 hour until uniform; the component B comprises: 90 parts by weight of ZnAl-based alloy powder, 5 parts by weight of nano rutile titanium dioxide, and 5 parts by weight of nano tricalcium aluminate, wherein the ZnAl-based alloy powder has a powder size of 10 μm and an element content of 43% Zn, 55% Al, and 2% trace alloying elements such as Mg, Si, and B. Component B is mixed in a stainless steel container at 600 rpm for 1 hour until uniform. Component A and component B were then mixed in a stainless steel container at a mass ratio of 1:3 at 600 rpm for 1 hour until uniform, and the mixture was filtered through a 200-mesh nylon mesh under vacuum to obtain the anti-corrosion coating.

[0055] The anti-corrosion coating was applied to rusted SPCC steel plates using a 300μm wire coating rod. The coating was then dried in an oven at 60°C for 2 hours and then left at room temperature at 25°C for 168 hours to obtain an anti-corrosion coating. The dry film thickness was measured using a thickness gauge and was approximately 155μm. The preparation process for rusted SPCC steel plates is as follows:

[0056] Step 1: First, use SPCC steel plate to sandblast, then put it into the salt spray box for 2 days to allow the surface of the substrate to be covered with rust. Figure 7 As shown in the left figure;

[0057] Step 2: Take out the rusty steel plate, brush and rinse it with a brush, and then bake it at (105±2)℃ for 1h;

[0058] Step 3: Use a wire brush to manually polish and remove the rust on the surface of the steel plate, retain the firmly attached rust, and use high-pressure air to blow away the dust on the surface to obtain the rusted SPCC steel plate. Figure 7 As shown in the figure on the right.

[0059] The adhesion test of the anti-corrosion coating was carried out according to the national standard "GB / T9286-2021". The photos before and after the test are as follows Figure 8 As shown, the coating adhesion is level 0.

[0060] According to the standard "GB / T1731-2020", the flexibility of the anti-corrosion coating is 1 mm;

[0061] According to the standard "GB / T1732-2020", the impact resistance of the anti-corrosion coating is 50cm;

[0062] The anticorrosive coating is tested for neutral salt spray resistance according to the national standard "GB / T1771-2007", and as shown in the following figure, the coating has a neutral salt spray resistance of 2000h. Figure 9 As shown in the following figure, the coating has a neutral salt spray resistance of 2000h.

[0063] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art can easily think of various equivalent modifications or replacements within the technical range disclosed by the present application, and these modifications or replacements should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A water-based cathodic protection and self-repairing and self-cleaning anti-corrosion coating for steel structures with rust, characterized in that: The anti-corrosion coating includes component A and component B; the component A includes the following ingredients in parts by weight: 20 to 30 parts by weight of deionized water, 40 to 55 parts by weight of water-based fluorocarbon acrylic resin, 2 to 5 parts by weight of tannic acid, 2 to 5 parts by weight of nano aluminum tripolyphosphate, and 15 to 26 parts by weight of nano conductive polymer; the component B includes the following ingredients in parts by weight: 60 to 90 parts by weight of ZnAl-based alloy powder, 5 to 25 parts by weight of nano rutile titanium dioxide, and 5 to 15 parts by weight of nano aluminate.

2. The water-based cathodic protection and self-repairing and self-cleaning anti-corrosion coating for steel structures according to claim 1 is characterized in that: The water-based fluorocarbon acrylic resin is a blended polymer of tetrafluoroethylene monomer or chlorotrifluoroethylene monomer and acrylic acid monomer.

3. The water-based cathodic protection and self-repairing and self-cleaning anti-corrosion coating for steel structures according to claim 1, characterized in that: The nano conductive polymer is a nano-sized polyaniline, polypyrrole or polythiophene material.

4. The water-based cathodic protection and self-repairing and self-cleaning anti-corrosion coating for steel structures according to claim 1, characterized in that: The ZnAl-based alloy powder has a particle size of ≤20 μm.

5. A water-based cathodic protection and self-repairing and self-cleaning anti-corrosion coating for steel structures according to claim 1 or 4, characterized in that: The mass percentage components of the ZnAl-based alloy powder are: Zn 43% to 82%, Al 12% to 55%, and trace alloy elements such as Mg, Si and B 2% to 6%.

6. The water-based cathodic protection and self-repairing and self-cleaning anti-corrosion coating for steel structures according to claim 1, characterized in that: The nano-aluminate is nano-tricalcium aluminate.

7. A water-based cathodic protection and self-repairing and self-cleaning anti-corrosion coating for steel structures according to any one of claims 1 to 6, characterized in that: The mass ratio of component A to component B is 1:(1-3).

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