Water-based anticorrosive coating for steel structure and preparation method thereof

Abstract

The present invention provides a water-based steel structure anticorrosion coating and a preparation method thereof, which belongs to the technical field of coatings, and comprises the following steps: step S1, preparing a di-tert-butyl salicylic acid modified water-based alkyd resin, mixing a di-tert-butyl salicylic acid solution with the water-based alkyd resin uniformly, and homogenizing to obtain a di-tert-butyl salicylic acid modified water-based alkyd resin; step S2, preparing a fluorinated acrylate modified cholestanoic acid, dissolving the cholestanoic acid in ethanol, adding fluorinated acrylate, heating and stirring to react, cooling, filtering, washing, and drying to obtain a fluorinated acrylate modified cholestanoic acid; step S3, mixing and stirring water, the di-tert-butyl salicylic acid modified water-based alkyd resin, the fluorinated acrylate modified cholestanoic acid, titanium dioxide and an additive to obtain a water-based steel structure anticorrosion coating. The technical solution provided by the present invention achieves the purpose of good coating anticorrosion.

Description

Technical Field

[0001] The invention relates to the technical field of coatings, and in particular to a water-based anti-corrosion coating for steel structures and a preparation method thereof. Background Art

[0002] With the development of economy and the progress of science and technology, metals and their alloys are still important application materials, but the problem of metal corrosion is inevitable. Metal corrosion is an irreversible process that will destroy the shape of components, weaken the mechanical properties of materials, reduce the life of equipment, and even cause accidents. Therefore, it is particularly important to study metal protection methods to reduce or prevent metal corrosion.

[0003] The main methods of metal corrosion protection include improving the metal environment, electrochemical protection and coating protection. Among them, the coating protection method is to cover the surface of the substrate with a coating to separate the substrate from the corrosive medium and reduce or prevent metal corrosion. The coating protection method can effectively alleviate metal corrosion, is not limited by the size of the equipment, has a simple construction method, and has multiple characteristics such as economy, convenience, and beauty. In recent years, water-based paints have attracted people's attention due to their advantages such as green and low carbon, high performance, and strong applicability, and have gradually become an important development direction of today's coatings.

[0004] Alkyd resin is a linear resin made by polycondensation of vegetable oil, polyacid and polyol. It is one of the earliest developed synthetic resins for coatings. Most of the raw materials used in the production of alkyd resin come from renewable resources, and it has the advantages of good flexibility and good wettability for pigments and fillers. However, it has the disadvantages of poor corrosion resistance and insufficient oxidation resistance, which makes it difficult to meet the requirements of industrial development for high-performance resins.

[0005] Therefore, it is necessary to provide a water-based steel structure anti-corrosion coating and a preparation method thereof to solve the problems existing in the above-mentioned prior art. Summary of the invention

[0006] In view of this, the present invention provides a water-based anti-corrosion coating for steel structures and a preparation method thereof, wherein the adhesion and corrosion resistance of the coating are improved by modifying the water-based alkyd resin with di-tert-butyl salicylic acid, and the oxidation resistance and corrosion resistance of the coating are improved by modifying cholesteric acid with fluorinated acrylate.

[0007] The specific scheme of the present invention is as follows: a method for preparing a water-based anti-corrosion coating for steel structures.

[0008] Step S1, preparing a di-tert-butyl salicylic acid modified waterborne alkyd resin, mixing a di-tert-butyl salicylic acid solution and a waterborne alkyd resin uniformly, and performing a homogenization treatment to obtain a di-tert-butyl salicylic acid modified waterborne alkyd resin;

[0009] Step S2, preparing fluorinated acrylate-modified cholestanoic acid, dissolving cholestanoic acid in ethanol, adding fluorinated acrylate, heating and stirring to react, cooling, filtering, washing, and drying to obtain fluorinated acrylate-modified cholestanoic acid;

[0010] Step S3, mixing water, the di-tert-butyl salicylic acid modified waterborne alkyd resin, the fluorinated acrylate modified cholestane acid, titanium dioxide and an additive to obtain a waterborne anticorrosive coating for steel structures.

[0011] Di-tert-butyl salicylic acid contains hydroxyl and carboxyl groups. These polar functional groups can form hydrogen bonds with hydrophilic groups (such as hydroxyl, ether bonds, etc.) in water-based alkyd resins. Through hydrogen bonding, the wettability is significantly improved, so that the coating can be evenly and stably coated on the surface of the steel structure, avoiding unevenness or gaps, and improving the adhesion of the coating. At the same time, the alkyl chain (such as tert-butyl) of di-tert-butyl salicylic acid is hydrophobic, which can produce hydrophobic interactions with the hydrophobic groups of the resin, reduce the intrusion of external water, improve the hydrophobicity of the surface of the coating, and enhance the stability and durability of the coating. The benzene ring structure contained in di-tert-butyl salicylic acid has a certain absorption capacity for ultraviolet rays, can effectively absorb ultraviolet light, reduce the generation of free radicals caused by light, thereby reducing the degradation rate of the coating and improving the stability of the coating. At the same time, di-tert-butyl salicylic acid can protect the functional groups in the alkyd resin that are susceptible to ultraviolet degradation by absorbing ultraviolet light, further reducing the decomposition and discoloration of the coating caused by light.

[0012] The hydroxyl and aromatic groups in the molecular structure of di-tert-butyl salicylic acid enhance the hydrogen bonds and π-π interactions between molecules, making the overall structure of the resin more stable and dense. The phenolic hydroxyl groups in di-tert-butyl salicylic acid can participate in the esterification reaction, promote the cross-linking reaction of alkyd resin, form a dense network structure, and effectively prevent the penetration of external chemicals. At the same time, the molecular chain spacing of the cross-linked resin is smaller, which reduces the diffusion capacity of the chemical substances, enhances the tolerance of the coating to chemical substances such as acids, alkalis, and solvents, and improves the corrosion resistance of the coating.

[0013] Cholesteric acid contains a long-chain fatty acid part, which can form hydrogen bonds and hydrophobic interactions in water to form a network structure. This structure increases the viscosity of the coating, making the coating more fluid during application, avoiding sedimentation, and increasing the adhesion of the coating. However, in water-based coatings, the solubility of cholesteric acid is low, so fluorinated acrylates are used to modify cholesteric acid to improve its dispersion compatibility in water-based alkyd resins. Fluorinated acrylates have extremely low surface tension and highly stable CF bonds, which can further reduce the surface energy of the coating, form a highly hydrophobic surface, effectively reduce the penetration of water and corrosive media into the coating, reduce the corrosion rate of steel, and improve the corrosion resistance of the coating. Fluorinated acrylates can also produce cross-linking reactions with the base alkyd resin, increase the cross-linking degree and hardness of the coating, thereby improving the mechanical strength and wear resistance of the coating, making it more durable in complex environments.

[0014] Cholesteric acid can remove free radicals and reduce the occurrence of oxidation reactions. Its carboxyl group can provide hydrogen atoms to react with free radicals. After the free radicals accept hydrogen atoms, they will form stable molecules, thereby reducing the activity of free radicals and protecting the components in the coating from oxidation. Cholesteric acid can chelate with metal ions, which helps to reduce the generation of metal-catalyzed free radicals, further reduce oxidation reactions, and improve antioxidant properties.

[0015] Optionally, in step S1, di-tert-butyl salicylic acid is dissolved in deionized water to obtain a di-tert-butyl salicylic acid solution; then the water-based alkyd resin is heated, the di-tert-butyl salicylic acid solution is added, stirred and cooled, and homogenized to obtain a di-tert-butyl salicylic acid-modified water-based alkyd resin.

[0016] Optionally, the heating temperature is 55-65°C; the stirring speed is 200-300 rpm, and the time is 2-3h; and the cooling is to 50-55°C.

[0017] Optionally, in step S2, cholestanoic acid is dissolved in ethanol, heated to accelerate dissolution, and then fluorinated acrylate is added, heated and stirred, and filtered, washed, and dried after cooling to obtain fluorinated acrylate-modified cholestanoic acid.

[0018] Optionally, the heating temperature is 30-40°C; the heating stirring speed is 300-400rpm, the temperature is 60-70°C, and the time is 2-3h.

[0019] Optionally, in step S3, the auxiliary agents include a bactericide, a defoamer and a drying agent; the bactericide is one of bactericide MBS, bactericide GXL and bactericide 2076; the defoamer is one of BYK190, BYK024 and BYK349; the drying agent is one of drying agent 101, drying agent 102 and drying agent 103; and the titanium dioxide is rutile type.

[0020] Titanium dioxide, especially rutile type, has a very high refractive index and strong light scattering ability, which can reduce the damage of ultraviolet rays to coatings and substrates and improve the aging resistance of coatings. At the same time, the high hardness and chemical stability of titanium dioxide make it have good wear resistance and long-term stability.

[0021] Optionally, in step S3, the di-tert-butyl salicylic acid modified water-based alkyd resin and water are added to a reactor, stirred for the first time, titanium dioxide is added, stirred for the second time, and then the fluorinated acrylate modified cholesteric acid is added, stirred for the third time, and finally an auxiliary agent is added and stirred for the fourth time to obtain a water-based steel structure anti-corrosion coating.

[0022] Optionally, the first stirring speed is 400-500rpm, and the time is 20-30min; the second stirring speed is 600-700rpm, and the time is 10-20min; the third stirring speed is 300-400rpm, and the time is 10-20min; the fourth stirring speed is 200-300rpm, and the time is 20-30min.

[0023] To achieve the above-mentioned purpose, the present invention also provides a water-based anti-corrosion coating for steel structures prepared by the above-mentioned method for preparing a water-based anti-corrosion coating for steel structures.

[0024] Optionally, the following components are included in parts by weight:

[0025] 65-75 parts of di-tert-butyl salicylic acid modified water-based alkyd resin, 8-10 parts of water, 20-25 parts of titanium dioxide, 8-10 parts of fluorinated acrylate modified cholestane acid, 0.5-1 part of bactericide, 1-1.5 parts of defoamer and 0.5-1 part of drying agent.

[0026] The raw materials of the di-tert-butyl salicylic acid modified waterborne alkyd resin include 1-2 parts of di-tert-butyl salicylic acid and 100-110 parts of waterborne alkyd resin; the raw materials of the fluorinated acrylate modified cholestane acid include 10-12 parts of fluorinated acrylate and 1-2 parts of cholestane acid.

[0027] The above technical solution of the present invention includes at least the following beneficial effects:

[0028] 1. The present invention introduces di-tert-butyl salicylic acid to modify the water-based alkyd resin, and utilizes the amphiphilic property of di-tert-butyl salicylic acid to improve the adhesion and stability of the coating; the hydroxyl group of di-tert-butyl salicylic acid can promote the cross-linking of the alkyd resin to form a denser network structure, thereby improving the corrosion resistance of the coating.

[0029] 2. The carboxyl group of cholestanoic acid can provide hydrogen atoms to react with free radicals, so that the free radicals form stable molecules, reduce the activity of free radicals, and protect the components in the coating from oxidation. In addition, cholestanoic acid can chelate with metal ions, which helps to reduce the generation of metal-catalyzed free radicals, further reduce the occurrence of oxidation reactions, and improve the oxidation resistance of the coating.

[0030] 3. Fluorinated acrylate has extremely low surface tension and highly stable CF bond. By copolymerizing and modifying cholesteric acid, it can effectively reduce the surface energy of the coating, form a highly hydrophobic surface, reduce the penetration of water and corrosive media into the coating, reduce the corrosion rate of steel, and improve the corrosion resistance of the coating. Fluorinated acrylate can also produce a cross-linking reaction with the base alkyd resin, increase the cross-linking degree and hardness of the coating, thereby improving the mechanical strength and wear resistance of the coating, making it more durable in complex environments. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described in combination with the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0032] Example 1

[0033] Take 2 parts of di-tert-butyl salicylic acid and dissolve it in 5 parts of deionized water, mix them evenly to obtain a di-tert-butyl salicylic acid solution; take 100 parts of water-based alkyd resin, heat it to 60°C, add the di-tert-butyl salicylic acid solution, stir it at 300 rpm for 2 hours, cool it to 50°C, add deionized water for homogenization, and obtain a di-tert-butyl salicylic acid modified water-based alkyd resin.

[0034] Dissolve 2 parts of cholestanoic acid in 100 parts of ethanol, heat to 40°C to accelerate dissolution, slowly add 12 parts of fluorinated acrylate and 0.02 parts of toluenesulfonic acid, heat to 65°C, stir at 350 rpm for 3 hours, cool to room temperature, filter, wash, and dry to obtain fluorinated acrylate-modified cholestanoic acid.

[0035] 70 parts of di-tert-butyl salicylic acid modified water-based alkyd resin and 10 parts of water are added to the reactor, stirred for the first time at a speed of 400 rpm for 30 minutes, 25 parts of titanium dioxide are added, stirred for the second time at a speed of 700 rpm for 10 minutes, 10 parts of fluorinated acrylate modified cholesteric acid are added, stirred for the third time at a speed of 300 rpm for 20 minutes, and finally 1 part of bactericide MBS, 1 part of defoamer 190 and 1 part of drying agent 101 are added, stirred for the fourth time at a speed of 200 rpm for 30 minutes to obtain a water-based steel structure anti-corrosion coating.

[0036] Example 2

[0037] Take 1 part of di-tert-butyl salicylic acid and dissolve it in 5 parts of deionized water, mix them evenly to obtain a di-tert-butyl salicylic acid solution; take 110 parts of water-based alkyd resin, heat it to 55°C, add the di-tert-butyl salicylic acid solution, stir it at 200 rpm for 2.5 hours, cool it to 55°C, add deionized water for homogenization, and obtain a di-tert-butyl salicylic acid modified water-based alkyd resin.

[0038] Dissolve 2 parts of cholestanoic acid in 100 parts of ethanol, heat to 40°C to accelerate dissolution, slowly add 11 parts of fluorinated acrylate and 0.02 parts of toluenesulfonic acid, heat to 60°C, stir at 300 rpm for 2.5 hours, cool to room temperature, filter, wash, and dry to obtain fluorinated acrylate-modified cholestanoic acid.

[0039] Add 65 parts of di-tert-butyl salicylic acid modified water-based alkyd resin and 10 parts of water into the reactor, stir for the first time at a speed of 500 rpm for 25 minutes, add 22 parts of titanium dioxide, stir for the second time at a speed of 700 rpm for 20 minutes, then add 9 parts of fluorinated acrylate modified cholesteric acid, stir for the third time at a speed of 350 rpm for 15 minutes, finally add 1 part of bactericide GXL, 1.5 parts of defoamer 024 and 0.5 parts of drying agent 102, stir for the fourth time at a speed of 300 rpm for 25 minutes to obtain a water-based anti-corrosion coating for steel structures.

[0040] Example 3

[0041] Take 1 part of di-tert-butyl salicylic acid and dissolve it in 5 parts of deionized water, mix them evenly to obtain a di-tert-butyl salicylic acid solution; take 110 parts of water-based alkyd resin, heat it to 65°C, add the di-tert-butyl salicylic acid solution, stir it at 300 rpm for 2 hours, cool it to 55°C, add deionized water for homogenization, and obtain a di-tert-butyl salicylic acid modified water-based alkyd resin.

[0042] Dissolve 2 parts of cholestanoic acid in 100 parts of ethanol, heat to 40°C to accelerate dissolution, slowly add 10 parts of fluorinated acrylate and 0.02 parts of toluenesulfonic acid, heat to 70°C, stir at 400 rpm for 2 hours, cool to room temperature, filter, wash, and dry to obtain fluorinated acrylate-modified cholestanoic acid.

[0043] 75 parts of di-tert-butyl salicylic acid modified water-based alkyd resin and 8 parts of water were added to the reactor, stirred for the first time at a speed of 450 rpm for 20 min, 20 parts of titanium dioxide were added, stirred for the second time at a speed of 600 rpm for 20 min, 8 parts of fluorinated acrylate modified cholesteric acid were added, stirred for the third time at a speed of 400 rpm for 10 min, and finally 0.5 parts of bactericide 2076, 1 part of defoamer 349 and 1 part of drying agent 103 were added, stirred for the fourth time at a speed of 250 rpm for 20 min to obtain a water-based anti-corrosion coating for steel structures.

[0044] Example 4

[0045] Take 2 parts of di-tert-butyl salicylic acid and dissolve it in 5 parts of deionized water, mix them evenly to obtain a di-tert-butyl salicylic acid solution; take 105 parts of water-based alkyd resin, heat it to 65°C, add the di-tert-butyl salicylic acid solution, stir it at 250rpm for 3h, cool it to 50°C, add deionized water for homogenization, and obtain a di-tert-butyl salicylic acid modified water-based alkyd resin.

[0046] Dissolve 1 part of cholestanoic acid in 100 parts of ethanol, heat to 40°C to accelerate dissolution, slowly add 11 parts of fluorinated acrylate and 0.02 parts of toluenesulfonic acid, heat to 60°C, stir at 400 rpm for 2 hours, cool to room temperature, filter, wash, and dry to obtain fluorinated acrylate-modified cholestanoic acid.

[0047] 65 parts of di-tert-butyl salicylic acid modified water-based alkyd resin and 8 parts of water were added to the reactor, stirred for the first time at a speed of 450 rpm for 25 minutes, 20 parts of titanium dioxide were added, stirred for the second time at a speed of 650 rpm for 10 minutes, 9 parts of fluorinated acrylate modified cholesteric acid were added, stirred for the third time at a speed of 300 rpm for 15 minutes, and finally 0.5 parts of bactericide GXL, 1.5 parts of defoamer 024 and 0.5 parts of drying agent 101 were added, stirred for the fourth time at a speed of 200 rpm for 30 minutes to obtain a water-based anti-corrosion coating for steel structures.

[0048] Example 5

[0049] Take 2 parts of di-tert-butyl salicylic acid and dissolve it in 5 parts of deionized water, mix them evenly to obtain a di-tert-butyl salicylic acid solution; take 100 parts of water-based alkyd resin, heat it to 55°C, add the di-tert-butyl salicylic acid solution, stir it at 200 rpm for 3 hours, cool it to 50°C, add deionized water for homogenization, and obtain a di-tert-butyl salicylic acid modified water-based alkyd resin.

[0050] Dissolve 1 part of cholestanoic acid in 100 parts of ethanol, heat to 40°C to accelerate dissolution, slowly add 12 parts of fluorinated acrylate and 0.02 parts of toluenesulfonic acid, heat to 70°C, stir at 350 rpm for 2 hours, cool to room temperature, filter, wash, and dry to obtain fluorinated acrylate-modified cholestanoic acid.

[0051] 75 parts of di-tert-butyl salicylic acid modified waterborne alkyd resin and 10 parts of water were added to the reactor, stirred for the first time at a speed of 400 rpm for 20 minutes, 25 parts of titanium dioxide were added, stirred for the second time at a speed of 650 rpm for 20 minutes, 10 parts of fluorinated acrylate modified cholesteric acid were added, stirred for the third time at a speed of 350 rpm for 20 minutes, and finally 1 part of bactericide MBS, 1 part of defoamer 190 and 1 part of drying agent 103 were added, stirred for the fourth time at a speed of 300 rpm for 25 minutes to obtain a waterborne anti-corrosion coating for steel structures.

[0052] Example 6

[0053] Take 1 part of di-tert-butyl salicylic acid and dissolve it in 5 parts of deionized water, mix them evenly to obtain a di-tert-butyl salicylic acid solution; take 105 parts of water-based alkyd resin, heat it to 50°C, add the di-tert-butyl salicylic acid solution, stir it at 250rpm for 2h, cool it to 55°C, add deionized water for homogenization, and obtain a di-tert-butyl salicylic acid modified water-based alkyd resin.

[0054] Dissolve 2 parts of cholestanoic acid in 100 parts of ethanol, heat to 40°C to accelerate dissolution, slowly add 10 parts of fluorinated acrylate and 0.02 parts of toluenesulfonic acid, heat to 65°C, stir at 300 rpm for 3 hours, cool to room temperature, filter, wash, and dry to obtain fluorinated acrylate-modified cholestanoic acid.

[0055] 70 parts of di-tert-butyl salicylic acid modified water-based alkyd resin and 9 parts of water were added to the reactor, stirred for the first time at a speed of 500 rpm for 30 minutes, 20 parts of titanium dioxide were added, stirred for the second time at a speed of 600 rpm for 15 minutes, 8 parts of fluorinated acrylate modified cholesteric acid were added, stirred for the third time at a speed of 400 rpm for 15 minutes, and finally 0.5 parts of bactericide 2076, 1.5 parts of defoamer 349 and 0.5 parts of drying agent 102 were added, stirred for the fourth time at a speed of 250 rpm for 30 minutes to obtain a water-based anti-corrosion coating for steel structures.

[0056] Example 7

[0057] Take 1 part of di-tert-butyl salicylic acid and dissolve it in 5 parts of deionized water, mix them evenly to obtain a di-tert-butyl salicylic acid solution; take 110 parts of water-based alkyd resin, heat it to 55°C, add the di-tert-butyl salicylic acid solution, stir it at 200 rpm for 2.5 hours, cool it to 55°C, add deionized water for homogenization, and obtain a di-tert-butyl salicylic acid modified water-based alkyd resin.

[0058] Dissolve 1 part of cholestanoic acid in 100 parts of ethanol, heat to 40°C to accelerate dissolution, slowly add 11 parts of fluorinated acrylate and 0.02 parts of toluenesulfonic acid, heat to 60°C, stir at 400 rpm for 2 hours, cool to room temperature, filter, wash, and dry to obtain fluorinated acrylate-modified cholestanoic acid.

[0059] 65 parts of di-tert-butyl salicylic acid modified waterborne alkyd resin and 10 parts of water were added to the reactor, stirred for the first time at a speed of 500 rpm for 25 minutes, 22 parts of titanium dioxide were added, stirred for the second time at a speed of 700 rpm for 20 minutes, 9 parts of fluorinated acrylate modified cholesteric acid were added, stirred for the third time at a speed of 350 rpm for 15 minutes, and finally 1 part of bactericide MBS, 1.5 parts of defoamer 190 and 0.5 parts of drying agent 103 were added, stirred for the fourth time at a speed of 300 rpm for 25 minutes to obtain a waterborne anti-corrosion coating for steel structures.

[0060] Example 8

[0061] Take 2 parts of di-tert-butyl salicylic acid and dissolve it in 5 parts of deionized water, mix them evenly to obtain a di-tert-butyl salicylic acid solution; take 100 parts of water-based alkyd resin, heat it to 50°C, add the di-tert-butyl salicylic acid solution, stir it at 250rpm for 2h, cool it to 55°C, add deionized water for homogenization, and obtain a di-tert-butyl salicylic acid modified water-based alkyd resin.

[0062] Dissolve 1 part of cholestanoic acid in 100 parts of ethanol, heat to 40°C to accelerate dissolution, slowly add 11 parts of fluorinated acrylate and 0.02 parts of toluenesulfonic acid, heat to 60°C, stir at 400 rpm for 2 hours, cool to room temperature, filter, wash, and dry to obtain fluorinated acrylate-modified cholestanoic acid.

[0063] 75 parts of di-tert-butyl salicylic acid modified water-based alkyd resin and 10 parts of water are added to the reactor, stirred for the first time at a speed of 400 rpm for 20 minutes, 25 parts of titanium dioxide are added, stirred for the second time at a speed of 650 rpm for 20 minutes, 10 parts of fluorinated acrylate modified cholesteric acid are added, stirred for the third time at a speed of 350 rpm for 20 minutes, and finally 1 part of bactericide GXL, 1 part of defoamer 024 and 1 part of drying agent 102 are added, stirred for the fourth time at a speed of 300 rpm for 25 minutes to obtain a water-based anti-corrosion coating for steel structures.

[0064] In the above embodiments, the fluorinated acrylates are all in monomer form, such as tridecafluorooctyl methacrylate, hexafluoroisopropyl methacrylate, and the like.

[0065] The present invention also carries out comparative examples and related tests.

[0066] Comparative Example 1

[0067] The difference between Comparative Example 1 and Example 1 is that di-tert-butyl salicylic acid is not used to modify the water-based alkyd resin, but a water-based alkyd resin is used. The other compositions and preparation methods are the same as those in Example 1, and a water-based steel structure anti-corrosion coating is prepared.

[0068] Comparative Example 2

[0069] The difference between Comparative Example 2 and Example 1 is that cholesteric acid is directly used instead of being modified by fluorinated acrylate, and the other compositions and preparation methods are the same as those of Example 1, and a water-based anti-corrosion coating for steel structures is prepared.

[0070] Comparative Example 3

[0071] The difference between Comparative Example 3 and Example 1 is that fluorinated acrylate is not used to modify cholesteric acid, but fluorinated acrylate is directly used. The other compositions and preparation methods are the same as those of Example 1, and a water-based anti-corrosion coating for steel structures is prepared.

[0072] Performance testing

[0073] The adhesion, corrosion resistance, toughness and wear resistance of the water-based anti-corrosion coatings for steel structures prepared in Examples 1-8 and Comparative Examples 1-3 were tested according to the following standards.

[0074] The reference standard for adhesion test is GB / T 5210-2006, and the evaluation index of test results is the destructive strength. The greater the destructive strength, the better the adhesion. The reference standard for corrosion resistance test is GB / T 9274-1998, and the evaluation standard for test results is whether there is blistering or shedding. The reference standard for toughness test is GB / T 6742-2007, and the evaluation standard for test results is whether cracks appear. The reference standard for wear resistance test is GB / T 1768-2006, and the evaluation standard for test results is (750g / 1000r) / mg. The smaller the wear mass, the better the wear resistance. The final test results are summarized in Table 1 below.

[0075] Table 1

[0076]

[0077] From the result data in Table 1, it can be seen that the anti-corrosion coatings obtained in Examples 1-8 of the present invention have good performance.

[0078] According to the comparison between Comparative Example 1 and Examples 1-8, it can be seen that the water-based alkyd resin was not modified with di-tert-butyl salicylic acid, resulting in a significant decrease in the adhesion and corrosion resistance of the coating, which shows that di-tert-butyl salicylic acid can effectively improve the adhesion and corrosion resistance of the coating. According to Comparative Example 2 and Examples 1-8, it can be seen that the fluorinated acrylate was not used to modify the cholesteric acid, resulting in a decrease in the corrosion resistance and toughness of the coating, which shows that the fluorinated acrylate modified cholesteric acid has an effect on the performance of the coating. According to Comparative Example 3 and Examples 1-8, it can be seen that only the use of fluorinated acrylates results in a decrease in the corrosion resistance, adhesion and antioxidant capacity of the coating.

[0079] The reference standard for the antioxidant test is GB / T 1766-2008, and the evaluation standard for the test results is whether chalking occurs; the reference standard for the UV resistance test is GB / T 1865-2009, and the evaluation standard for the test results is whether discoloration occurs. The final test results are summarized in Table 2 below.

[0080] Table 2

[0081]

[0082] From the result data in Table 2, it can be seen that the anti-corrosion coatings obtained in Examples 1-8 of the present invention have good performance.

[0083] According to Comparative Example 1, it can be seen that the water-based alkyd resin is not modified by di-tert-butyl salicylic acid, resulting in a decrease in the oxidation resistance and drying speed of the coating. It can be seen that di-tert-butyl salicylic acid modified water-based alkyd resin can effectively improve the oxidation resistance and drying speed of the coating. According to Comparative Example 2, it can be seen that the fluorinated acrylate is not used to modify cholestanoic acid, resulting in a decrease in the oxidation resistance of the coating. It can be seen that the fluorinated acrylate is used to modify cholestanoic acid, which can make cholestanoic acid play a better effect in the coating and improve the oxidation resistance of the coating. According to Comparative Example 3, it can be seen that only fluorinated acrylate is used without cholestanoic acid, resulting in a significant decrease in the oxidation resistance of the coating. It can be seen that cholestanoic acid can effectively improve the oxidation resistance of the coating.

[0084] The above are preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for preparing a water-based anti-corrosion coating for steel structures, characterized in that: The following steps are involved: Step S1, preparing a di-tert-butyl salicylic acid modified waterborne alkyd resin, mixing a di-tert-butyl salicylic acid solution and a waterborne alkyd resin uniformly, and performing a homogenization treatment to obtain a di-tert-butyl salicylic acid modified waterborne alkyd resin; Step S2, preparing fluorinated acrylate-modified cholestanoic acid, dissolving cholestanoic acid in ethanol, adding fluorinated acrylate, heating and stirring to react, cooling, filtering, washing, and drying to obtain fluorinated acrylate-modified cholestanoic acid; Step S3, mixing water, the di-tert-butyl salicylic acid modified waterborne alkyd resin, the fluorinated acrylate modified cholestane acid, titanium dioxide and an additive to obtain a waterborne anticorrosive coating for steel structures.

2. The method for preparing a water-based anticorrosive coating for steel structures according to claim 1, characterized in that: In the step S1, di-tert-butyl salicylic acid is dissolved in deionized water to obtain a di-tert-butyl salicylic acid solution; then the water-based alkyd resin is heated, the di-tert-butyl salicylic acid solution is added, stirred and cooled, and the di-tert-butyl salicylic acid modified water-based alkyd resin is obtained after homogenization.

3. The method for preparing a water-based anticorrosive coating for steel structures according to claim 2, characterized in that: The heating temperature is 55-65°C; the stirring speed is 200-300 rpm, and the time is 2-3 hours; and the cooling temperature is 50-55°C.

4. The method for preparing a water-based anticorrosive coating for steel structures according to claim 1, characterized in that: In the step S2, cholestanoic acid is dissolved in ethanol, heated to accelerate dissolution, and then fluorinated acrylate is added, heated and stirred, and after cooling, filtered, washed, and dried to obtain fluorinated acrylate-modified cholestanoic acid.

5. The method for preparing a water-based anticorrosive coating for steel structures according to claim 4, characterized in that: The heating temperature is 30-40°C; the heating and stirring speed is 300-400rpm, the temperature is 60-70°C, and the time is 2-3h.

6. The method for preparing a water-based anticorrosive coating for steel structures according to claim 1, characterized in that: In step S3, the auxiliary agents include a bactericide, a defoamer and a drying agent; the bactericide is one of bactericide MBS and bactericide GXL; the defoamer is BYK024; and the titanium dioxide is rutile.

7. The method for preparing a water-based anticorrosive coating for steel structures according to claim 1, characterized in that: In the step S3, the di-tert-butyl salicylic acid modified water-based alkyd resin and water are added to a reactor, stirred for the first time, titanium dioxide is added, stirred for the second time, and then the fluorinated acrylate modified cholesteric acid is added, stirred for the third time, and finally an auxiliary agent is added, stirred for the fourth time to obtain a water-based steel structure anti-corrosion coating.

8. The method for preparing a water-based anticorrosive coating for steel structures according to claim 7, characterized in that: The first stirring speed is 400-500rpm, and the time is 20-30min; the second stirring speed is 600-700rpm, and the time is 10-20min; the third stirring speed is 300-400rpm, and the time is 10-20min; the fourth stirring speed is 200-300rpm, and the time is 20-30min.

9. A water-based anti-corrosion coating for steel structures, characterized in that: The water-based anti-corrosion coating for steel structures is prepared by the preparation method of any one of claims 1 to 8.

10. The water-based anti-corrosion coating for steel structures according to claim 9, characterized in that: The composition comprises the following components in parts by weight: 65-75 parts of di-tert-butyl salicylic acid modified waterborne alkyd resin, 8-10 parts of water, 20-25 parts of titanium dioxide, 8-10 parts of fluorinated acrylate modified cholestane acid, 0.5-1 part of bactericide, 1-1.5 parts of defoamer and 0.5-1 part of drying agent; The raw materials of the di-tert-butyl salicylic acid modified waterborne alkyd resin include 1-2 parts of di-tert-butyl salicylic acid and 100-110 parts of waterborne alkyd resin; the raw materials of the fluorinated acrylate modified cholestane acid include 10-12 parts of fluorinated acrylate and 1-2 parts of cholestane acid.

Images