Two-component water-based high-temperature-resistant anticorrosive paint, preparation method and application thereof

Abstract

The application discloses a two-component water-based high-temperature-resistant anticorrosive paint as well as a preparation method and application thereof, and belongs to the technical field of paints. The paint A component provided by the application simultaneously adds methylphenyl silicone resin and water glass with a modulus of 5.0-8.0, and zinc phosphate, kaolin, iron oxide red, aluminum oxide and a thickening agent are added, and meanwhile, the mass percentage range of silane coupling agent in the A component to zinc phosphate, kaolin, iron oxide red and aluminum oxide in the A component is limited, so that excellent dispersibility and suitable viscosity between the components can be realized, the adhesion and the anticorrosion performance of the coating are ensured, further introduction of glass powder can improve the high-temperature resistance of the paint. In addition, the preparation method of the paint is simple in operation and is beneficial to actual production.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of coatings, and particularly relates to a two-component water-based high-temperature-resistant anticorrosive coating as well as a preparation method and application thereof. BACKGROUND

[0002] High-temperature-resistant coating refers to a coating that can be used in an environment of 200 DEG C for a long time and maintain certain protective performance. The mainstream high-temperature-resistant coating types are organic silicon high-temperature-resistant coating and inorganic high-temperature-resistant coating. Currently, the metal outer walls of high-temperature-resistant equipment in industrial equipment, such as high-temperature boilers, exhaust pipes, chimneys, and petroleum cracking towers, usually use organic silicon high-temperature-resistant coating, and the inner walls use organic silicon high-temperature-resistant coating or inorganic high-temperature-resistant coating according to the temperature range. However, these coatings mainly consider the temperature resistance, and the domestic research on the corrosion resistance of the coatings for a long time is insufficient, which leads to the fact that the metal equipment or high-temperature devices are easily corroded under the action of humid air, marine atmosphere, and corrosive gas, greatly affecting the service life and safety of the equipment.

[0003] The organic silicon high-temperature-resistant coating usually uses organic silicon resin as a film-forming binder. In an environment with a temperature lower than 300 DEG C, the coating film is mainly composed of organic matter. When the temperature is higher than 300 DEG C, the organic components are gradually decomposed to form a highly cross-linked Si-O-Si structure. Although the structure is more stable, the decomposition of part of the components will make the coating film more susceptible to gas or water vapor corrosion, thereby causing metal corrosion. In addition, the organic silicon high-temperature-resistant coating has the disadvantages of slow drying speed and poor adhesion. Moreover, the organic silicon high-temperature-resistant coating in the prior art is mainly solvent-based. With the increasingly stringent environmental requirements in China, the application of solvent-based coatings is also increasingly limited. For example, the high-temperature-resistant coatings disclosed in the prior art CN107400460A, CN107936828A, and CN115368800A are mainly solvent-based. In addition, the corrosion resistance of the coating layer is not studied.

[0004] The inorganic high-temperature-resistant coating is usually prepared from water glass, silica sol, ethyl silicate, and other materials. Its high-temperature resistance can reach more than 600 DEG C. However, due to the poor adhesion of the inorganic high-temperature-resistant coating, the requirements for the substrate treatment are high, and it is necessary to strictly meet the requirement of sandblasting level of Sa2.5 to ensure the adhesion of the coating. It is difficult to adhere to the smooth substrate. In addition, the water glass has strong hydrophilicity, and the corrosion resistance of the coating is also poor. For example, patent CN111471334A discloses a preparation method of a water-based inorganic high-temperature-resistant coating, which mainly considers the high-temperature resistance of the coating. However, the water resistance of the coating is poor, and the corrosion resistance of the coating is not considered. SUMMARY

[0005] The present application aims to overcome the deficiencies of the prior art and provide a two-component water-based high-temperature-resistant anticorrosive coating with excellent adhesion, excellent high-temperature resistance and excellent corrosion resistance, as well as a preparation method and application thereof.

[0006] To achieve the above-mentioned purpose, in the first aspect of the present application, the present application provides a two-component water-based high-temperature-resistant anticorrosive coating, which comprises component A and component B.

[0007] The component A comprises the following components by mass fraction: methylphenyl silicone resin 10-25 parts, water glass 25-35 parts, zinc phosphate 8-12 parts, kaolin 4-10 parts, glass powder 5-15 parts, red iron oxide 5-12 parts, alumina 3-12 parts, wetting agent 0.1-0.2 parts, dispersant 0.6-1 parts, stabilizer 0.1-0.3 parts, defoamer 0.1-0.2 parts, thickening agent 0.5-1.5 parts, deionized water 5-10 parts;

[0008] The component B comprises a silane coupling agent.

[0009] The modulus of the water glass is 5.0-8.0.

[0010] The initial melting temperature of the glass powder is 350-450℃.

[0011] The mass percentage of the silane coupling agent in the component B is 5-15% based on the total fraction of zinc phosphate, kaolin, red iron oxide and alumina in the component A.

[0012] The coating provided by the present application has excellent high-temperature resistance, corrosion resistance and adhesion by selecting appropriate mass fractions of components and having excellent mutual synergy and cooperation between components. The prepared coating can be used at 300℃ for a long time on unblasted steel and can be used at 800℃ for a long time on steel with a blasting level of Sa2.5.

[0013] Specifically, the present application provides a coating A component, which simultaneously adds methylphenyl silicone resin and water glass with a modulus of 5.0-8.0 as a film-forming material. In the subsequent use process, when mixed with the B component, the silane coupling agent can couple the methylphenyl silicone resin and the water glass together through a chemical bond, improve the dispersibility of the organic resin and the inorganic resin in the coating film, enable the methylphenyl silicone resin to be uniformly dispersed in the network structure of the water glass, improve the water resistance and flexibility of the inorganic coating, improve the overall sealing property of the coating, further improve the overall corrosion resistance of the coating, and effectively enhance the adhesion to the substrate. Further, the present application selects zinc phosphate and iron oxide red as the anti-rust pigment, glass powder, aluminum oxide and kaolin as the high-temperature resistant filler, and adjusts the viscosity of the coating by using a thickening agent. In the subsequent application, when the A component and the B component are mixed, the silane coupling agent accounts for 5-15% of the total amount of zinc phosphate, kaolin, iron oxide red and aluminum oxide. After hydrolysis, the silane coupling agent can react with zinc phosphate, iron oxide red and the like to improve the dispersibility thereof in the coating film, thereby improving the sealing property of the coating, improving the corrosion resistance of the coating, and ensuring good adhesion of the coating. In addition, in an application environment with a temperature lower than 300℃, the methylphenyl silicone resin can stably exist, and under the action of the silane coupling agent, the coating has good adhesion on a steel plate without sandblasting; when the temperature is 300-500℃, the silicone coating begins to decompose, and the glass powder with an initial melting temperature of 350-450℃ begins to melt, thereby providing reinforcement to the coating film and continuously maintaining excellent corrosion resistance of the coating; further application in an environment with a temperature higher than 300℃ also has good adhesion to a sandblasted steel material at high temperature.

[0014] The initial melting temperature of the glass powder is the temperature at which the glass powder begins to melt. After the organic coating decomposes, the molten glass powder and other components cooperate to provide good reinforcement and sealing to the coating, thereby ensuring the corrosion resistance of the coating. The initial melting temperature of the glass powder selected by the present application can be any point value or any two-point range value between 350-450℃, such as 350℃, 360℃, 370℃, 380℃, 390℃, 400℃, 410℃, 420℃, 430℃, 440℃, 450℃, etc. Within the initial melting temperature range given by the present application, the effects of the present application can be achieved. If the initial melting temperature of the glass powder is too high, after the organic coating begins to decompose, the glass powder has not yet melted, and the density of the coating will decrease, resulting in a decrease in the corrosion resistance of the coating. The corrosion resistance will continue to improve only when the temperature reaches the initial melting temperature of the glass powder.

[0015] Illustratively, the glass powder can be D240 of Guangdong Qicheng New Material Technology Co., Ltd.

[0016] As a preferred embodiment of the coating according to the present application, the methylphenyl silicone resin comprises at least one of an acrylic-modified methylphenyl silicone resin, an epoxy-modified methylphenyl silicone resin.

[0017] The present application researches and finds that the methylphenyl silicone resin according to the present application can still remain stable at 300 DEG C, has good high-temperature resistance after being combined with other components, and will not be decomposed at 300 DEG C, so that the compactness of the coating can be ensured. After partial chemical bonds are broken and decomposed at high temperature, a large number of inorganic Si-O bonds are still retained to form a compact paint film, so that the compactness of the coating is significantly improved, thereby ensuring the corrosion resistance of the coating.

[0018] Exemplarily, the methylphenyl silicone resin can be BXY-2203 high-temperature pure silicone resin emulsion of Foshan Guangsi New Material Co., Ltd., SW series water-based silicone emulsion of Changzhou Jianuo Silicone Co., Ltd., SH-9606 acrylic-modified silicone resin emulsion and SH-9608 epoxy-modified silicone resin of Hubei Longsheng Sihai, etc.

[0019] As a preferred embodiment of the coating according to the present application, the water glass comprises at least one of potassium silicate water glass and lithium silicate water glass.

[0020] The modulus of the water glass can be any point value or any two-point range value between 5.0 and 8.0, such as 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, etc. Within the range given in the present application, the effects of the present application can be achieved; when the modulus of the water glass is too low, the water resistance of the obtained coating is poor, and the hydrophilicity is strong, which leads to the decrease of the corrosion resistance of the coating.

[0021] Preferably, the water glass is at least one of potassium silicate water glass with a modulus of 5.0-6.5 and lithium silicate water glass with a modulus of 6.0-8.0.

[0022] Exemplarily, the water glass can be potassium silicate water glass with a modulus of 5.5, potassium silicate water glass with a modulus of 6.5, and lithium silicate water glass with a modulus of 8.0 produced by Zhejiang Yuda Chemical Industry Co., Ltd., and potassium silicate water glass with a modulus of 3.9 produced by Heye Chemical Co., Ltd.

[0023] As a preferred embodiment of the coating according to the present application, the zinc phosphate is spherical zinc phosphate with an average particle size of ≤10 μm.

[0024] The present application researches and finds that the spherical zinc phosphate with a smaller particle size has a larger specific surface area, can provide more bonding under the action of hydrolysis, and form a firm chemical bond with the substrate, so that the adhesion of the coating is improved, and the anti-rust effect is further improved, thereby improving the corrosion resistance.

[0025] Exemplarily, the zinc phosphate can be ZP-10 of Heubach Company in Germany or J-0806 of Mineral Company in the United States.

[0026] As a preferred embodiment of the coating of the present application, the average particle size of the iron oxide red is 800-1200 mesh.

[0027] Exemplarily, the iron oxide red can be S130H of Guangzhou Yuan Sheng Commerce and Trade Co., Ltd., etc.

[0028] The present application researches and finds that the iron oxide red selected by the present application not only has excellent rust prevention ability, but also has excellent high temperature resistance, and further cooperates with the zinc phosphate to provide good corrosion resistance for the coating film. Specifically, the zinc phosphate and the iron oxide red selected by the present application can still exist stably at 900℃, and the coating will not discolor after long-term use at high temperature. At the same time, since the system of the present application contains a large amount of water glass, the iron oxide red and the zinc phosphate will not hydrolyze due to the high pH value of the system, that is, the stability of the system can be ensured.

[0029] As a preferred embodiment of the coating of the present application, the aluminum oxide is flaky aluminum oxide with an average particle size of ≤10 μm.

[0030] Exemplarily, the aluminum oxide can be aluminum oxide of Henan Sicheng Grinding Technology Co., Ltd.

[0031] The aluminum oxide added in the present application is a high-temperature-resistant filler, which can be used to cooperate with other components to realize the role of reinforcing the strength of the coating; at the same time, the aluminum oxide has good heat conduction performance, can make the high-temperature coating fully and uniformly radiate heat, thereby improving the coating film falling caused by stress change in the cooling process; further preferably, the flaky aluminum oxide can effectively increase the specific surface area, thereby further enhancing the heat conduction performance and sealing performance of the coating, and effectively improving the heat conduction performance and corrosion resistance.

[0032] As a preferred embodiment of the coating of the present application, at least one of (a)-(e):

[0033] (a) the wetting agent comprises at least one of an anionic surfactant, a nonionic surfactant;

[0034] (b) the dispersing agent comprises an anionic dispersing agent;

[0035] (c) the defoaming agent comprises an organic silicon defoaming agent;

[0036] (d) the stabilizer comprises a silicate stabilizer;

[0037] (e) the thickening agent comprises at least one of aqueous bentonite, fumed silica, hydroxyethyl cellulose ether, methyl hydroxyethyl cellulose, xanthan gum.

[0038] Exemplarily, the wetting agent can be CROSFECT DA202 of fatty alcohol polyoxyethylene ether of Ounhua Chemical, SURFYNOL 104E of alkynediol nonionic surfactant of Yinqing Gas Chemical, DISPERBYK-193 of BYK Chemical, or the like.

[0039] Exemplarily, the dispersing agent can be TEGO Dispers 752W, Tamol NN 8906 of BASF anionic surfactant, or the like.

[0040] Exemplarily, the defoaming agent can be TEGO 901W of Dige Chemical, byk-080A of BYK Chemical, PARATROL 810 of Guardian Chemicals, or the like.

[0041] Exemplarily, the stabilizer can be CROSFECT CS1 of Xinxin Chemical, LOPON ST silicate coating stabilizer of ICL, or the like.

[0042] Exemplarily, the thickening agent can be HT-W603, HT-W805 of Haidis, or the like.

[0043] The present application researches and finds that when the thickening agent of the present application is selected, it has good thickening characteristics for water glass, and can thicken in the system of the present application and keep the system viscosity stable.

[0044] Exemplarily, the silane coupling agent can be KH560, WD61, KH580, or the like.

[0045] In the second aspect of the present application, the present application provides a preparation method of the coating, and the preparation method comprises the following steps:

[0046] (1) Preparation of component A: add wetting agent, dispersing agent, stabilizer and water glass into deionized water in sequence, mix uniformly, then add thickening agent and part of defoaming agent, mix uniformly, then add zinc phosphate, kaolin, iron oxide red, glass powder, alumina in sequence, mix uniformly, then add methylphenyl silicone resin and the remaining part of defoaming agent in sequence, mix uniformly, finally filter, collect the filtrate, and obtain component A;

[0047] (2) Preparation of component B: disperse the silane coupling agent, and obtain component B.

[0048] As a preferred embodiment of the preparation method of the present application, the part of defoaming agent accounts for 40-60% of the total mass of the defoaming agent.

[0049] In the third aspect of the present application, the present application provides a use method of the coating, which is: mixing the A component and the B component, then curing at 30-50℃ for 50-70min, and then using.

[0050] The present application researches and finds that, in the use process, mixing the A component and the B component, then curing at 30-50℃ for 50-70min, and then using can make the performance of the coating film more excellent.

[0051] In the fourth aspect of the present application, the present application provides an application of the coating in preparing high-temperature corrosion-resistant equipment.

[0052] The coating provided by the present application can be applied to un-sandblasted steel and also to sandblasted steel; specifically, the coating provided by the present application can be applied to un-sandblasted steel below 300℃, and is suitable for environments with low temperature resistance requirements and unsuitable for sandblasting, such as high-temperature pipeline equipment coating repair; meanwhile, the coating can also be applied to steel with sandblasting reaching Sa2.5 level, and can be stably used at 800℃.

[0053] Compared with the prior art, the present application has the following beneficial effects:

[0054] The coating A component provided by the present application simultaneously adds methylphenyl silicone resin and water glass with a modulus of 5.0-8.0, and adds zinc phosphate, kaolin, red iron oxide, aluminum oxide and a thickening agent, and meanwhile limits the mass percentage range of the silane coupling agent in the B component relative to the zinc phosphate, kaolin, red iron oxide and aluminum oxide in the A component, so as to realize excellent dispersibility and suitable viscosity between the components, ensure the adhesion and corrosion resistance of the coating, further introduce glass powder, and improve the high-temperature resistance of the coating. Specifically, the coating provided by the present application has a 1-level crosshatch adhesion after 300℃ on un-sandblasted steel plate, a 1-level crosshatch adhesion after 800℃ on sandblasted steel plate, and a salt spray resistance of the coating reaching more than 400h. In addition, the preparation method of the coating provided by the present application is simple to operate, and is beneficial to actual production. DETAILED DESCRIPTION

[0055] For the purpose of better illustrating the present application, technical solutions and advantages, the present application will be further described in combination with specific examples.

[0056] The reagents, methods and equipment used in the present application are all conventional reagents, methods and equipment in the field, unless otherwise specified.

[0057] Methylphenyl silicone resin 1: acrylic modified silicone resin emulsion, SH-9606, Hubei Longshisihai;

[0058] Methylphenyl silicone resin 2: pure silicone resin emulsion, BXY-2203, Foshan Guangsi New Material Co., Ltd.

[0059] Water glass 1: potassium silicate water glass, modulus 5.5, Zhejiang Yuda Chemical Industry Co., Ltd.;

[0060] Water glass 2: lithium silicate water glass, modulus 8.0, Zhejiang Yuda Chemical Industry Co., Ltd.;

[0061] Water glass 3: potassium silicate water glass, modulus 3.9, Heye Chemical Industry Co., Ltd.;

[0062] Water glass 4: potassium silicate water glass, modulus 8.8, Zhejiang Yuda Chemical Industry Co., Ltd.;

[0063] Zinc phosphate: spherical zinc phosphate with an average particle size of 3 μm, ZP-10, Heubach Co., Ltd., Germany;

[0064] Glass powder 1: initial melting temperature 400℃, D240, Guangdong Qichen New Material Technology Co., Ltd.;

[0065] Glass powder 2: initial melting temperature 650℃, 650℃ glass powder, Lingzhou Junkai New Material Co., Ltd.;

[0066] Iron oxide red: S130H, average particle size 800 mesh, Guangzhou Yuan Sheng Trade Co., Ltd.;

[0067] Alumina: flaky alumina with an average particle size of 8 μm, Henan Sicheng Grinding Technology Co., Ltd.;

[0068] Wetting agent: DISPERBYK-193, BYK Chemical;

[0069] Dispersant: Tamol NN 8906, BASF;

[0070] Stabilizer: CROSFECT CS1, Xinxun Chemical Industry Co., Ltd.;

[0071] Defoaming agent: byk-080A, BYK Chemical;

[0072] Thickening agent 1: water-based bentonite, HT-W805, Haidis;

[0073] Thickening agent 2: hydroxyethyl cellulose, Ashland, USA;

[0074] Silane coupling agent: KH560, Wuda.

[0075] Examples 1-6 and Comparative Examples 1-13

[0076] The examples and comparative examples of the present application provide a two-component high-temperature-resistant anticorrosive coating, the components (mass parts) of which are shown in Tables 1-2;

[0077] Table 1

[0078]

[0079]

[0080] Table 2

[0081]

[0082]

[0083] The preparation method of the two-component water-based high-temperature resistant anticorrosive paint provided in Example 1 comprises the following steps:

[0084] (1) sequentially add deionized water, wetting agent, dispersant, stabilizer, and water glass into a dispersion kettle, and stir uniformly at a stirring speed of 500 rpm;

[0085] (2) sequentially add thickening agent and 50% defoaming agent, and stir at a stirring speed of 2000 r / min for 25 min until uniform and no particles;

[0086] (3) continue to add zinc phosphate, kaolin, glass powder, red iron oxide, and aluminum oxide, and stir at a stirring speed of 2000 rpm for 30 min;

[0087] (4) reduce the stirring speed to 500 r / min, add methylphenyl silicone resin and the remaining defoaming agent, disperse for 10 min, and filter and package after uniform stirring; obtain component A;

[0088] (5) weigh the silane coupling agent, filter and package; obtain component B.

[0089] The preparation methods of the two-component water-based high-temperature resistant anticorrosive paints provided in Examples 2-6 and Comparative Examples 1-13 are consistent with those of Example 1.

[0090] Effect example

[0091] The performance of the two-component water-based high-temperature resistant anticorrosive paints provided in the verification examples and comparative examples of the present application is verified;

[0092] The component A and component B of the two-component water-based high-temperature resistant anticorrosive paints provided in the examples and comparative examples are mixed, aged at 40°C for 60 min, and then used, including two aspects of testing, the first aspect: the paint is sprayed on a carbon steel plate without sandblasting, the sample plate is placed in a muffle furnace and heated to 300°C for 72 h, and after cooling, the coating adhesion and salt spray resistance are tested; the second aspect: the paint is sprayed on a carbon steel plate with a sandblasting level of Sa2.5, the sample plate is heated to 800°C in a muffle furnace for 72 h, and after the coating is cooled, the coating adhesion and salt spray resistance are tested;

[0093] 1. Paint state: place component A at 50°C for 30 d, and observe the state of component A;

[0094] 2. Coating adhesion was tested according to the method of GB / T 9286-2021 Cross-hatch test for paint films of pigmented and clear coatings;

[0095] 3. Corrosion resistance was tested according to the method of GB / T 1771-2007 Determination of resistance to neutral salt spray of pigmented and clear coatings;

[0096] 4. Heat resistance: the film state of the coating after being placed at 300℃ or 800℃ for 72h was observed;

[0097] The test results are shown in Table 3;

[0098] Table 3

[0099]

[0100]

[0101] As can be seen from Table 3, the two-component water-based high-temperature resistant anticorrosive coating prepared by using the technical scheme of the present application has excellent comprehensive performance, the coating obtained has a cross-hatch adhesion of 1 level after 300℃ on the un-blasted steel plate, and no powdering and no falling off after being placed for 72h, has a cross-hatch adhesion of 1 level after 800℃ on the blasted steel plate, and no powdering and no falling off after being placed for 72h; and the salt spray resistance of the coating is more than 400h on the un-blasted steel plate and more than 480h on the blasted steel plate at 800℃;

[0102] As can be seen from Example 1, Example 4 and Comparative Examples 1-2, the modulus of the water glass used also affects the comprehensive performance of the product, when the modulus of the water glass used in Comparative Example 1 is not within the range given by the present application, specifically too low, the salt spray resistance of the coating obtained is significantly reduced, rust appears after 168h at 300℃ and 800℃; when the modulus of the water glass used in Comparative Example 2 is not within the range given by the present application, specifically too high, the stability of the product obtained is poor, and the product is prone to demulsification gel;

[0103] As can be seen from Example 1 and Comparative Example 3, when the initial melting temperature of the glass powder used is not within the range given by the present application, specifically too high, the organic resin part of the coating obtained is partially decomposed at 300℃, while the glass powder has not yet started to melt at this temperature, the pores left in the system affect the corrosion resistance of the coating, so rust appears after 240h in the un-blasted state, when the temperature continues to increase to 800℃, the glass powder starts to melt, the pores are partially filled, and the salt spray resistance is improved again, but it cannot reach the level of Example 1, which is reflected in the performance data as a significant decrease in the salt spray resistance time;

[0104] As can be seen from Example 1, Example 6 and Comparative Examples 4-5, the amount of silane coupling agent added also affects the comprehensive performance of the product. When the amount of silane coupling agent added in Comparative Example 4 is too small, the grid method adhesion at 300°C and 800°C for 72 hours is grade 2, which is lower than that of the examples, indicating that the amount of coupling agent is insufficient, the modification of the powder and the substrate is not sufficient, and the adhesion and corrosion resistance do not achieve the best effect. When the amount of silane coupling agent added in Comparative Example 5 is too large, the grid method adhesion at 300°C is grade 3, which is significantly lower than that of Example 1. This indicates that when the amount of coupling agent is excessive, the adhesion begins to decrease, which may be due to the fact that the excessive coupling agent is difficult to fully hydrolyze during the construction period, thereby affecting the dispersion performance of the system and leading to a decrease in adhesion performance.

[0105] As can be seen from Example 1 and Comparative Example 6, when no silane coupling agent is added, the adhesion of the paint is poor when used on a steel plate without sandblasting, the grid method adhesion is grade 5, the paint film partially falls off, and the salt spray performance is also poor, making it unsuitable for long-term use. At the same time, the grid method adhesion at 800°C is grade 3, indicating that the adhesion of the product decreases significantly at both high and relatively low temperatures.

[0106] As can be seen from Example 1 and Comparative Example 7, when an acrylic emulsion is used as the organic modified resin, the salt spray performance of the system decreases significantly, which may be due to the fact that the organic resin decomposes in large quantities, leading to an increase in the voids of the coating and affecting the density of the coating, thereby affecting the corrosion resistance of the coating and significantly decreasing the adhesion of the product.

[0107] As can be seen from Example 1 and Comparative Example 8, when aluminum tripolyphosphate is used instead of zinc phosphate, the aluminum tripolyphosphate is not stable under strong alkaline conditions, leading to demulsification and gelation of the system.

[0108] As can be seen from Example 1 and Comparative Example 9, when iron oxide yellow is added instead of iron oxide red, the grid method adhesion of the coating at 300°C is grade 2, indicating that the adhesion decreases. In actual use, the coating gradually turns red at high temperatures, and the discoloration of the coating is severe. This is because the iron yellow powder is not stable at high temperatures and gradually changes to Fe2O3, which is red, leading to a significant decrease in the corrosion resistance of the system, which is reflected in a decrease in the time without abnormalities.

[0109] As can be seen from Example 1 and Comparative Example 10, when no zinc phosphate is added, the adhesion of the coating on the un-sandblasted steel plate decreases after 300°C, because the silane-modified zinc phosphate forms chelate bonds with phosphate and the metal substrate, enhancing the adhesion of the coating, and the zinc phosphate as a rust-proof pigment significantly improves the corrosion resistance of the coating; as can be seen from Example 1 and Comparative Example 11, when no red iron oxide is added, the corrosion resistance of the coating decreases; as can be seen from Example 1 and Comparative Example 12, when no kaolin is added, the product obtained is prone to peeling on the un-sandblasted steel plate after 300°C, and the corrosion resistance at 300°C and 800°C both show a decreasing trend; as can be seen from Example 1 and Comparative Example 13, when no alumina is added, the product obtained shows a decreasing trend in the salt spray performance on the un-sandblasted steel plate and the adhesion.

[0110] Finally, it should be noted that the above examples are intended to illustrate the technical solutions of the present application rather than limit the protection scope of the present application, and although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced equivalently without departing from the essence and scope of the technical solutions of the present application.

Claims

1. A two-component water-based high-temperature resistant anti-corrosion coating, characterized in that, The coating comprises component A and component B; Component A comprises the following components in parts by weight: 20-25 parts methylphenyl silicone resin, 25-30 parts water glass, 8-10 parts zinc phosphate, 5-7 parts kaolin, 8-12 parts glass powder, 5-8 parts iron oxide red, 4-8 parts alumina, 0.1-0.2 parts wetting agent, 0.6-1 part dispersant, 0.1-0.3 parts stabilizer, 0.1-0.2 parts defoamer, 0.5-1.5 parts thickener, and 5-10 parts deionized water; Component B includes a silane coupling agent; The modulus of the water glass is 5.0-8.0; The initial melting temperature of the glass powder is 350-450℃; Based on the total proportions of zinc phosphate, kaolin, iron oxide red, and aluminum oxide in component A, the mass percentage of silane coupling agent in component B is 5-15%. The zinc phosphate is spherical zinc phosphate with an average particle size ≤10μm; The average particle size of the iron oxide red is 800-1200 mesh; The alumina is flake-shaped alumina with an average particle size ≤10μm.

2. The coating according to claim 1, characterized in that, The methylphenyl silicone resin includes at least one of acrylic acid-modified methylphenyl silicone resin and epoxy-modified methylphenyl silicone resin.

3. The coating according to claim 1, characterized in that, The water glass includes at least one of potassium silicate water glass and lithium silicate water glass.

4. The coating according to claim 1, characterized in that, At least one of (a)-(e): (a) The wetting agent includes at least one of anionic surfactants and nonionic surfactants; (b) The dispersant includes anionic dispersants; (c) The defoamer includes silicone defoamers; (d) The stabilizer includes a silicate stabilizer; (e) The thickener includes at least one of aqueous bentonite, fumed silica, hydroxyethyl cellulose ether, methyl hydroxyethyl cellulose, and xanthan gum.

5. The method for preparing the coating according to any one of claims 1-4, characterized in that, The preparation method includes the following steps: (1) Preparation of component A: Wetting agent, dispersant, stabilizer and water glass were added to deionized water in sequence and mixed evenly. Then thickener and part of defoamer were added and mixed evenly. Zinc phosphate, kaolin, iron oxide red, glass powder and alumina were added in sequence and mixed evenly. Then methylphenyl silicone resin and the remaining part of defoamer were added in sequence and mixed evenly. Finally, the mixture was filtered and the filtrate was collected to obtain component A. (2) Preparation of component B: Disperse the silane coupling agent to obtain component B.

6. The method of using the coating as described in any one of claims 1-4, characterized in that, The method of use is as follows: Mix components A and B and let it mature at 30-50℃ for 50-70 minutes before use.

7. The application of the coating as described in any one of claims 1-4 in the preparation of high-temperature corrosion-resistant equipment.

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