Environment-friendly high-performance anticorrosive paint for steel structural member of contact network

Abstract

The invention belongs to the technical field of anticorrosive coatings, and particularly discloses an environment-friendly high-performance anticorrosive coating for a steel structural member of a contact network, which comprises the following components in percentage by mass: 15-35% of acrylate-based emulsion, 30-50% of arginine modified conductive metal particles, 10-20% of superfine zinc powder, 0.5-1% of hydroxyethyl cellulose, 0.5-1% of an antioxidant, 0.5-1% of a defoaming agent, 0.5-1% of a defoaming agent and the balance of water. The cleaning agent comprises the following components in percentage by weight: 0.5 to 1 percent of dispersing agent, 0.5 to 1 percent of defoaming agent, 0.5 to 1 percent of n-caprylic alcohol The anticorrosive paint disclosed by the invention has the advantages of long anticorrosive time, long fireproof time, long service life, good weather resistance, good decoration, water-based environment friendliness and the like; in addition, the paint is simple in construction and preparation, excellent in fireproof effect, environmentally friendly, biodegradable, capable of providing safe and environment-friendly antirust protection in VCI application, suitable for occasions with high requirements for environmental protection and suitable for application and popularization.

Description

Technical Field

[0001] The invention belongs to the technical field of anti-corrosion coatings, and in particular relates to a high-performance anti-corrosion coating for environmentally friendly contact network steel structural parts. Background Art

[0002] Vapor Corrosion Inhibitor (VCI) is a chemical substance that can inhibit metal corrosion in the gas phase. They can produce volatile substances that are slowly released into the air to form trace gas phase compounds. These compounds are deposited on the metal surface to form a molecular-level protective film. This protective film can effectively prevent oxygen, water vapor and other corrosive substances from contacting the metal surface, thereby playing an anti-rust role. Thus, the metal surface is prevented from contacting with corrosive substances (such as water vapor and oxygen).

[0003] Common VCI chemical components include amine compounds, amino acids and their derivatives, aldehyde compounds and organic acid salts. Amine compounds such as sodium naphthenate and sodium benzoate have good volatility and anti-rust effects, and are suitable for paper and film; amino acids such as glycine and proline are environmentally friendly and have good biodegradability, and are suitable for occasions with high environmental protection requirements; aldehyde compounds such as formaldehyde and acetaldehyde have significant anti-rust effects, but attention should be paid to their safety and toxicity; organic acid salts such as sodium benzoate and sodium naphthenate have good anti-rust effects and relatively low toxicity.

[0004] Common metal anti-corrosion VCI chemical components are mainly amine compounds and organic acid salts. These components provide good anti-rust effects while being relatively easy to handle and safe. However, since organic acid salts often require organic solvents during the synthesis and preparation process, or are phenyl-containing compounds themselves, they often have certain toxicity, making these anti-corrosion coatings not environmentally friendly.

[0005] In addition, the addition of these VCIs cannot enhance the flame retardant effect, making the anti-corrosion coatings based on such VCIs have no flame retardant or fireproof effects. When used in railway contact networks, high-voltage power transmission, cables and other fields, it is often necessary to apply another layer of fire-retardant coating to meet fire protection requirements.

[0006] Therefore, further exploring VCI fillers with flame retardant or fireproof effects and optimizing their preparation process have important practical application value and research significance. Summary of the invention

[0007] The main purpose of the present invention is to provide an environmentally friendly high-performance anti-corrosion coating for steel structural parts of a contact network in view of the deficiencies in the prior art. The synthesis of the arginine-modified conductive metal particles contained in the coating formula is simple, with water as the solvent, and the arginine and phytic acid in the raw materials can be obtained from biological sources. As a new type of vapor phase corrosion inhibitor, it can simultaneously enhance the anti-corrosion and flame retardant effects of the coating. The anti-corrosion and fire-retardant coating has the advantages of long anti-corrosion time, long fire-resistant time, excellent adhesion, short drying time, and environmental friendliness, and is suitable for promotion and application.

[0008] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: an environmentally friendly high-performance anti-corrosion coating for contact network steel structural parts, the components and their mass percentages include: 15-35% acrylate-based emulsion, 30-50% arginine-modified conductive metal particles, 10-20% ultrafine zinc powder, 0.5-1% hydroxyethyl cellulose, 0.5-1% dispersant, 0.5-1% defoaming agent, 0.5-1% n-octanol, and the rest is water.

[0009] Preferably, the high-performance anti-corrosion coating for the environmentally friendly contact network steel structural parts comprises the following components and their mass percentages: 15-35% acrylate-based emulsion, 30-50% arginine-modified conductive metal particles, 20% ultrafine zinc powder, 0.5% hydroxyethyl cellulose, 0.5% dispersant, 0.5% defoaming agent, 0.5% n-octanol, and the rest water.

[0010] In the above scheme, the acrylate-based emulsion can be selected from acrylate emulsion, methacrylate emulsion, styrene-acrylic emulsion or styrene-acrylic core-shell emulsion, etc.; its solid content is 30-55%, and the condensation rate is 0.1-2%.

[0011] In the above solution, the particle size of the ultrafine zinc powder is 10-100 microns.

[0012] In the above solution, the dispersant is the wetting dispersant 5040; and the defoaming agent is the silicone defoaming agent 470.

[0013] In the above scheme, the arginine-modified conductive metal particles are prepared from nickel metal particles, arginine and phytic acid, and the preparation method comprises the following steps: adding arginine, phytic acid and nickel metal particles in a mass ratio of (1-2): (1-2): (0.1-1) to a mixed solution of ethanol and water, stirring at a rate of 100-1000 rpm, concentrating at 50-100 degrees Celsius, and then vacuum drying, washing the obtained yellow liquid with a mixed solution of ethyl acetate and petroleum ether in a mass ratio of 1:1-1:2. Then drying at 50-70 degrees Celsius.

[0014] In the above scheme, the size of nickel metal particles is 500nm-500μm.

[0015] The method for preparing the above-mentioned high-performance anti-corrosion coating for the environmentally friendly contact network steel structure comprises the following steps:

[0016] 1) Weigh the raw materials according to the ratio;

[0017] 2) The weighed arginine-modified conductive metal particles, hydroxyethyl cellulose, and ultrafine zinc powder are uniformly mixed and ground into a powder without particles, and then water is added and stirred and ground until uniform without obvious particles; then a defoamer and a dispersant are added, and stirring and grinding is continued to be uniform;

[0018] 3) Finally, add the acrylic ester-based emulsion and n-octanol, grind and mix evenly to obtain the anti-corrosion coating.

[0019] The principle of the present invention is:

[0020] The present invention prepares a water-based high-performance environmentally friendly anticorrosion and fireproof coating based on arginine-modified conductive metal particles. The introduction of arginine-modified conductive metal particles improves the anticorrosion effect of the coating on structural parts (especially the surface of steel structure buildings). Arginine-modified conductive metal particles are prepared from arginine, phytic acid and nickel metal particles. The nickel particles are easily oxidized, agglomerated and other problems affect the conductivity. Arginine contains amino / carboxylic acid bifunctional groups, and phytic acid is rich in phosphorus hydroxyl groups. A dense coating layer can be formed by coordination to slowly release amine gases, forming a protective gas phase in a closed space, covering the metal surface, preventing oxygen and moisture from directly contacting the metal, thereby inhibiting rust. After phytate contacts the metal surface, a thin passivation film can be formed by adsorption, and this film can effectively prevent the redox reaction from proceeding, thereby reducing the occurrence of corrosion. When arginine and phytate are used in combination, the antirust effect can be improved by a synergistic effect, and the performance of the gas phase inhibitor can be enhanced. This composite can be better stabilized in the gas phase and evenly distributed on the metal surface. Arginine-modified conductive metal particles can react with the coating matrix when burned, releasing phosphoric acid substances through the acid source - phytic acid to react with the matrix, and the nitrogen source - arginine to release non-flammable gas, thereby producing an expanded porous carbon layer. In addition, arginine and phytic acid are both natural products, environmentally friendly and biodegradable, which makes them safe and environmentally friendly in VCI applications. Anti-rust protection is suitable for occasions with high environmental requirements.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1) The anticorrosive coating obtained by the present invention has the advantages of long anticorrosion time, long fireproof time, long service life, good weather resistance, good decorativeness, water-based and environmental protection, etc.; and the construction preparation involved is simple, the fireproof effect is excellent, and it is suitable for promotion and application;

[0023] 2) The arginine-modified conductive metal particles of the present invention can enhance the flame retardant effect of traditional anticorrosion coatings, so that the anticorrosion coatings based on such VCI have flame retardant or fireproof effects, and can be applied to fields that may face fire risks, such as high-voltage power transmission and cables;

[0024] 3) Compared with traditional VCI vapor phase corrosion inhibitors, arginine-modified conductive metal particles have advantages such as environmental friendliness and biodegradability, which can provide a new idea for the preparation of environmentally friendly anti-corrosion and fire-retardant coatings;

[0025] 4) Arginine and phytic acid are biomass materials that are easy to obtain, inexpensive, and environmentally friendly; meanwhile, the coating uses water as a solvent, which is environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a comparison diagram of the morphology of the anti-corrosion coatings obtained in Example 1 and Comparative Example 1 after being subjected to a simulated cross-bay environmental salt spray test (5% sodium chloride aqueous solution, adding hydrochloric acid to adjust the pH to 6.0-6.3, 7 days);

[0027] Figure 2 The large plate combustion method back temperature curve diagram of the anti-corrosion coating obtained in Example 1 and Comparative Example 1;

[0028] Figure 3 The Nyquist spectra of the anticorrosive coatings obtained in Example 1 and Comparative Example 1;

[0029] Figure 4 The Bode spectra of the anticorrosive coatings obtained in Example 1 and Comparative Example 1 are shown;

[0030] Figure 5 Bode spectra of the anti-corrosion coatings obtained in Example 1 and Comparative Example 1. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0032] In the following examples, the dispersant used is wetting dispersant 5040; the defoaming agent is silicone defoaming agent 470.

[0033] In the following examples, the acrylate-based emulsion used is an acrylate emulsion, and its preparation method comprises the following steps:

[0034] 1) Dissolve 1.0g of alkylphenol polyoxyethylene ether and 2.0g of sodium lauryl sulfate in 90ml of deionized water to prepare an emulsifier aqueous solution, and divide it into three parts: 35ml, 30ml and 25ml; add 50g of n-butyl acrylate and 10g of methyl methacrylate to 30ml of the emulsifier aqueous solution, stir and mix at room temperature, pre-emulsify for 1h, and prepare a core pre-emulsion; add 10g of n-butyl acrylate, 30g of methyl methacrylate and 2.4g of methacrylic acid to 30ml of the emulsifier aqueous solution, stir and mix at room temperature, pre-emulsify for 2h, and prepare a shell pre-emulsion; dissolve 0.3g of sodium bicarbonate in 25ml of the emulsifier aqueous solution and stir to dissolve to prepare a buffer aqueous solution; add 0.5g of potassium persulfate to 30ml of deionized water and stir to dissolve to prepare an initiator aqueous solution;

[0035] 2) Preparation of seed emulsion: In a reaction vessel, add a buffer solution, 1 / 3 volume of an initiator solution and 1 / 2 volume of a nuclear pre-emulsion solution in sequence while stirring, raise the temperature to 70°C, and when a large amount of blue light appears in the emulsion, keep the temperature for 0.5h to obtain a seed emulsion;

[0036] 3) Core layer polymerization: When the seed emulsion is kept warm, slowly drip the remaining core pre-emulsion and 1 / 3 of the initiator aqueous solution into the seed emulsion, and complete the dripping within 1 hour. Control the temperature to 80°C and keep warm for 0.5 hours to obtain the core layer emulsion;

[0037] 4) Shell polymerization: When the core emulsion is kept warm, the remaining initiator aqueous solution and shell pre-emulsion are added dropwise within 1.5 hours, and then the temperature is raised to 85°C and kept warm for 0.5 hours, and then naturally cooled to 40°C, the pH value is adjusted to 8, and the mixture is passed through a 200-mesh sieve to obtain an acrylic core-shell emulsion with a solid content of 41% and a coagulation rate of 0.34%.

[0038] In the following examples, the method for preparing arginine-modified conductive metal particles comprises the following steps:

[0039] Arginine, phytic acid and nickel metal particles with a mass ratio of 1.5:1:0.3 were added to a mixed solution of ethanol and water (volume ratio: 1:1), wherein the nickel metal particle size was 500nm, the stirring rate was 300rpm, concentrated at 80 degrees Celsius, and then vacuum dried, and the obtained yellow liquid was washed with a mixed solution of ethyl acetate and petroleum ether with a mass ratio of 1:1.33. Then dried at 60 degrees Celsius.

[0040] Example 1

[0041] An anticorrosive coating, wherein the components and their mass percentages are: 35% acrylate-based emulsion, 30% arginine-modified conductive metal particles, 20% ultrafine zinc powder, 0.5% hydroxyethyl cellulose, 0.5% dispersant, 0.5% defoamer, 0.5% n-octanol, and 13% water; the preparation method thereof comprises the following steps:

[0042] 1) Weigh the raw materials according to the above ratio requirements;

[0043] 2) Grind the weighed arginine-modified conductive metal particles, hydroxyethyl cellulose, and ultrafine zinc powder until there are no particles, then add water to fully grind and mix them evenly; then add defoaming agent and dispersant, and continue to fully grind;

[0044] 3) Finally, add the acrylate-based emulsion and n-octanol, grind and mix thoroughly to obtain the anti-corrosion coating.

[0045] Example 2

[0046] An anti-corrosion coating, the preparation method of which is roughly the same as that of Example 1, except that the components and their mass percentages are: 25% acrylate-based emulsion, 40% arginine-modified conductive metal particles, 20% ultrafine zinc powder, 0.5% hydroxyethyl cellulose, 0.5% dispersant, 0.5% defoamer, 0.5% n-octanol, and 13% water.

[0047] Example 3

[0048] An anti-corrosion coating, the preparation method of which is roughly the same as that of Example 1, except that the components and their mass percentages are: 15% acrylate-based emulsion, 50% arginine-modified conductive metal particles, 20% ultrafine zinc powder, 0.5% hydroxyethyl cellulose, 0.5% dispersant, 0.5% defoamer, 0.5% n-octanol, and 13% water.

[0049] Comparative Example 1

[0050] A coating, the preparation method of which is substantially the same as that of Example 1, except that the components and their mass percentages are: 65% acrylate-based emulsion, 20% ultrafine zinc powder, 0.5% hydroxyethyl cellulose, 0.5% dispersant, 0.5% defoamer, 0.5% n-octanol, and 13% water.

[0051] Comparative Example 2

[0052] A coating, the preparation method of which is substantially the same as that of Example 1, except that the components and their mass percentages are: 85% acrylate-based emulsion, 0.5% hydroxyethyl cellulose, 0.5% dispersant, 0.5% defoamer, 0.5% n-octanol, and 13% water.

[0053] The anticorrosive coatings obtained in Examples 1 to 3 and Comparative Examples 1 to 2 were subjected to a simulated cross-bay area environment salt spray test and a fire resistance test, and the results are shown in Table 1. All steel structure substrates tested were Q325 steel.

[0054] Table 1 Performance test results of the intumescent fire retardant coatings obtained in Examples 1 to 3 and Comparative Examples 1 to 2

[0055]

[0056] Surface morphology after salt spray corrosion resistance: Check the rust condition of the coating surface according to the requirements of GB / T 1766-2008 "Rating method for aging of paint and varnish coatings".

[0057] The evaluation criteria are as follows:

[0058] Ri0: 0% rust area, no rust.

[0059] Ri1: 0.05% rusted area, very slightly rusted.

[0060] Ri2: 0.5% rusted area, slightly rusted.

[0061] Ri3: 1% rusted area, obvious rust.

[0062] Ri4: 8% rust area, large rust.

[0063] Ri5: 40%-50% rusted area, severe rust.

[0064] Figure 1 This is a comparison of the morphologies of the anti-corrosion coatings obtained in Example 1 and Comparative Example 1 before and after the simulated cross-bay environmental salt spray test. From the figure, it can be seen that there are no obvious signs of corrosion on the surface of Example 1 before the test, while there are obviously a large number of white corrosion products on the surface of Comparative Example 1 after the test.

[0065] Figure 2 The back temperature curve of the large plate combustion method of the anticorrosive coating obtained in Example 1 and Comparative Example 1 is shown in the figure; it can be seen that the back plate temperature of Example 1 is significantly lower than that of Comparative Example 1. And it can be maintained within 250 degrees within 60 minutes.

[0066] The barrier properties of Example 1 and Comparative Example 1 were tested. Example 1 and Comparative Example 1 were immersed in a 3.5% NaCl aqueous solution for 7 days, and then electrochemical impedance spectroscopy was performed. The test results are shown in the attached specification. Figure 3 , 4 , as shown in Figure 5.

[0067] In the Nyquist diagram, the larger the radius of the capacitive reactance arc in the high-frequency region, the better the barrier performance of the coating, corresponding to better corrosion resistance. Figure 3 As shown, the order of the size of the capacitive reactance arc radius in the high-frequency region is that Example 1 is greater than Comparative Example 1. It can be seen that the shielding performance of the coating obtained in Example 1 is better than that of Comparative Example 1.

[0068] In the Bode spectrum, the low-frequency impedance modulus (|Z|0.01Hz) in the electrochemical impedance test is a semi-quantitative indicator of the corresponding coating's ability to shield the penetration of corrosive media (water, oxygen, chloride ions, etc.). The larger the impedance modulus, the stronger the corresponding ability to shield the penetration of corrosive substances. Figure 4 As shown in Figure 5, the low-frequency impedance modulus of the coating obtained in Example 1 is obviously greater than that in Comparative Example 1, so its shielding effect on corrosive media is better.

[0069] The above results show that the high-performance anti-corrosion coating for environmentally friendly contact network steel structural parts obtained by the present invention has good anti-corrosion performance and flame retardant effect, is environmentally friendly and pollution-free, has good durability, is compatible with the substrate, has good adsorption, and can effectively take into account other properties of the substrate. The preparation method involved in the present invention is simple and effective, and has a wide range of applications.

[0070] Obviously, the above embodiments are merely examples for clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from this are still within the protection scope of the invention.

Claims

1. An environmentally friendly high-performance anti-corrosion coating for steel structural parts of contact network, characterized in that: The components and their mass percentages include: 15-35% of acrylate-based emulsion, 30-50% of arginine-modified conductive metal particles, 10-20% of ultrafine zinc powder, 0.5-1% of hydroxyethyl cellulose, 0.5-1% of dispersant, 0.5-1% of defoamer, 0.5-1% of n-octanol, and the rest is water.

2. The high-performance anti-corrosion coating for environmentally friendly contact network steel structural parts according to claim 1 is characterized in that: The components and their mass percentages include: 15-35% of acrylate-based emulsion, 30-50% of arginine-modified conductive metal particles, 20% of ultrafine zinc powder, 0.5% of hydroxyethyl cellulose, 0.5% of dispersant, 0.5% of defoamer, 0.5% of n-octanol, and the rest of water.

3. The high-performance anti-corrosion coating for environmentally friendly contact network steel structural parts according to claim 1 is characterized in that: The acrylate-based emulsion includes one or more of acrylate emulsion, methacrylate emulsion, styrene-acrylic emulsion or styrene-acrylic core-shell emulsion; the acrylate-based emulsion has a solid content of 30-55% and a condensation rate of 0.1-2%.

4. The high-performance anti-corrosion coating for environmentally friendly contact network steel structural parts according to claim 1 is characterized in that: The dispersant is the wetting dispersant 5040; the defoaming agent is the silicone defoaming agent 470.

5. The high-performance anti-corrosion coating for environmentally friendly contact network steel structural parts according to claim 1 or 2, characterized in that: The arginine-modified conductive metal particles are characterized in that the arginine-modified conductive metal particles are made from arginine, phytic acid and nickel metal particles; the size of the nickel metal particles is 500nm-500μm.

6. The high-performance anti-corrosion coating for environmentally friendly contact network steel structural parts according to claim 5 is characterized in that: The method for synthesizing the arginine-modified conductive metal particles comprises: adding arginine, phytic acid and nickel metal particles in a mass ratio of (1-2):(1-2):(0.1-1) to a mixed solution of ethanol and water, stirring at a rate of 100-1000 rpm, concentrating at 50-100 degrees Celsius, and then vacuum drying; washing the obtained yellow liquid with a mixed solution of ethyl acetate and petroleum ether in a mass ratio of 1:1-1:2, and drying.

7. The high-performance anti-corrosion coating for environmentally friendly contact network steel structural parts according to claim 1 is characterized in that: The particle size of the ultrafine zinc powder is 10-100 microns.

8. The method for preparing the high-performance anti-corrosion coating for the environmentally friendly contact network steel structure according to any one of claims 1 to 7, characterized in that: The steps include: 1) Weigh the raw materials according to the ratio; 2) Evenly mix the arginine-modified conductive metal particles, hydroxyethyl cellulose and ultrafine zinc powder, grind until there is no particle powder, then add water, stir and grind until it is uniform and no obvious particles exist; then add defoamer and dispersant, continue to stir and grind evenly; 3) Finally, add the acrylic ester-based emulsion and n-octanol, grind and mix evenly to obtain the anti-corrosion coating.

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