Water-based high-temperature-resistant dew point corrosion-resistant coating as well as preparation method and construction process thereof

Abstract

The invention discloses a water-based high-temperature-resistant dew point corrosion-resistant coating as well as a preparation method and a construction process thereof, and belongs to the technical field of anticorrosive coatings. The coating is composed of emulsified asphalt, a high-temperature-resistant resin emulsion, a styrene-butadiene emulsion, a functional filler, an auxiliary agent, water and other raw materials, and through reasonable proportioning and a specific preparation process, the coating has excellent high temperature resistance and dew point corrosion resistance. Wherein the functional filler synergistically plays a shielding and blocking role, and a film forming system ensures strong adhesive force and chemical stability of the coating and a base material. The coating is low in VOC content, environmentally friendly, safe, capable of being used for a long time in the environment of 230-250 DEG C, free of phenomena of bubbling, cracking and falling of a paint film, capable of effectively resisting erosion of condensate water and corrosive media, suitable for protection of metal equipment in the industries of petrochemical engineering, electric power, metallurgy and the like, convenient to construct and long in service life, and has remarkable practical value and popularization prospects.

Description

Technical Field

[0001] This invention relates to the field of anti-corrosion coatings, specifically to a water-based high-temperature resistant anti-dew-point corrosion coating and its preparation method and application process. Background Technology

[0002] In industries such as petrochemicals, power, metallurgy, and marine engineering, metal equipment (such as chimneys, flues, oil and gas pipelines, and industrial furnaces) is constantly exposed to high-temperature environments with large temperature fluctuations. The fuels used include coal, liquefied petroleum gas (LPG), natural gas, fuel oil, and other mixed fuels. These fuels contain sulfur and chlorine, which, upon combustion, form SO2 / SO3 and chloride ions. At low temperatures, these condense into acid, corroding steel, iron, and other metal structures. Therefore, on the one hand, the equipment must withstand temperatures exceeding 200°C; on the other hand, due to the temperature difference between the ambient environment and the equipment surface, when the metal surface temperature is lower than the ambient air dew point temperature, condensation easily forms on the surface. This condensate film absorbs corrosive media such as oxygen, sulfur dioxide, hydrogen sulfide, and chloride ions from the air, triggering severe electrochemical corrosion (i.e., dew point corrosion).

[0003] In existing technologies, traditional high-temperature resistant coatings often lack effective dew point corrosion protection. Materials such as asphalt, water glass, and structural fibers fail to meet requirements in terms of operating temperature, elongation, and corrosion resistance, thus failing to provide dew point protection. In condensation environments, these materials are prone to coating penetration, blistering, and peeling, leading to under-film corrosion. Furthermore, conventional dew point corrosion resistant coatings have limited high-temperature resistance, failing to meet the demands of high-temperature operating conditions. Simultaneously, traditional solvent-based coatings have high VOC content, easily causing environmental pollution during application and posing safety hazards, thus failing to comply with increasingly stringent environmental protection policies. Therefore, developing a coating that combines excellent high-temperature resistance, dew point corrosion protection, and environmental safety is crucial to solving these technical challenges. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a water-based high-temperature resistant anti-dew-point corrosion coating and its preparation method, aiming to solve the corrosion problem of metal equipment under high-temperature and condensation conditions. This coating is environmentally friendly with low VOCs, easy to apply, and has a long service life, while also possessing excellent high-temperature resistance and anti-dew-point corrosion performance. Furthermore, this coating product adopts a cold-applied application method, which is convenient to use and can significantly reduce project costs and energy consumption.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] The water-based high-temperature resistant and dew-point corrosion-resistant coating of the present invention comprises, by weight, the following raw materials: 200-220 parts emulsified asphalt, 210-230 parts high-temperature resistant resin emulsion, 100-120 parts styrene-butadiene emulsion, 60-80 parts silica powder, 95-115 parts mica powder, 60-80 parts barium sulfate, 6-8 parts fumed silica, 3-3.4 parts thickener, 5-7 parts dispersant, 2-2.2 parts defoamer, 13-15 parts film-forming agent, 6-8 parts ammonia water, 7-9 parts flash rust inhibitor, and 0-5% diluent.

[0007] Preferably, the emulsified asphalt is a water-based emulsified asphalt with a solid content of 60%, providing basic film-forming support; the high-temperature resistant resin emulsion is a water-based organosilicon resin emulsion, giving the coating excellent high-temperature resistance and chemical stability; the styrene-butadiene emulsion is used to improve the toughness of the coating and prevent the coating from cracking under high temperature or external force.

[0008] Preferably, the functional filler system composed of silicon micro powder, mica powder, barium sulfate, and fumed silica is as follows: mica powder and barium sulfate are sheet-like fillers that are arranged in parallel overlapping patterns in the coating to form a "maze effect" and extend the penetration path of corrosive media; silicon micro powder enhances the adhesion between the coating and the substrate; fumed silica inhibits the thermal shrinkage of the coating at high temperatures, while improving the coating's weather resistance, scratch resistance, and bonding strength between the coating and the substrate.

[0009] Preferably, the film-forming agent is an alcohol ester film-forming aid, used to regulate the evaporation rate of the coating, promote uniform drying of the paint film, reduce pinholes, craters and cracking, and enhance the continuity and density of the paint film; ammonia is used to adjust the pH value of the coating and improve the storage stability of the product; the anti-flash rust agent can effectively prevent flash rust from occurring on the metal substrate during construction and use.

[0010] Preferably, the thickener is a reverse thickener, which modifies the polymer chain structure of polyacrylamide through reactive polysiloxane compounds, improving its compatibility with the main resin and thickening efficiency, ensuring no sagging during coating application, and is especially suitable for vertical surface application; the dispersant is an anionic dispersant, ensuring uniform dispersion of fillers without agglomeration; the defoamer is an organosilicon or polyether defoamer, eliminating bubbles generated during coating preparation and application, and ensuring the smoothness of the paint film.

[0011] Preferably, the diluent is deionized water to prevent metal ions such as calcium, magnesium, and iron, as well as impurity ions such as chloride and sulfate, from affecting the dispersion stability of the coating and to improve the storage stability of the product.

[0012] The present invention also provides a method for preparing the above-mentioned water-based high-temperature resistant and dew-point corrosion-resistant coating, comprising the following steps:

[0013] (1) Pre-dispersion: Emulsified asphalt, silicone resin emulsion and styrene-butadiene emulsion are added to the mixing tank at the same ratio and stirred at 500-800 r / min for 15-20 min to ensure that the three film-forming substrates are fully and evenly mixed;

[0014] (2) Addition and dispersion of fillers: Add silica powder, mica powder, barium sulfate and fumed silica in sequence, increase the rotation speed to 1200-1500 r / min, disperse at high speed for 30-40 min, control the material temperature at 25-35℃ during dispersion to avoid the temperature from affecting the performance of raw materials, and at the same time ensure that the fillers are uniformly dispersed without agglomeration.

[0015] (3) Additives: Adjust the speed to 800-1000r / min, add dispersant, defoamer, solubilizer and anti-flash rust agent in sequence, stir for 10-15 minutes, add ammonia water, continue stirring for 20-25 minutes, add thickener, and stir for 10-15 minutes.

[0016] (4) Dilution and filtration: Add 0-5% dilution water according to construction requirements, stir for 10-15 minutes, and then filter through a 200-300 mesh filter to remove impurities and incompletely dispersed particles to obtain the finished coating.

[0017] This invention also provides a method for applying the above-mentioned coating, comprising the following steps:

[0018] (a) Substrate preparation: Remove loose paint, dirt, grease, mold and other contaminants from the surface of the metal substrate. Sandblast the metal surface to Sa2.0 grade or manually treat it to St2 grade. The roughness is controlled at 5-70 micrometers to ensure the adhesion between the coating and the substrate.

[0019] (b) Construction environment control: The construction temperature should be 5-45℃;

[0020] (c) Coating method: spraying, brushing, roller coating or airless spraying. For air spraying, use nozzles with a diameter of 3 mm or more and an air pressure of 4-7 kg; for airless spraying, use nozzles with a diameter of 0.64-0.89 mm, a spray width of 30-60 cm and a spraying pressure of 16-20 MPa.

[0021] (d) Number of coating coats and intervals: Apply 3-6 coats in total, with an interval of 4-6 hours between each coat. Ensure that the previous coat is completely dry and free of drips before applying the next coat. The wet film thickness of a single spray is ≥1000 micrometers, and the total dry film thickness is ≥2000 μm.

[0022] (e) Curing: Curing at room temperature for 4-6 hours per coat, with the last coat requiring 8 hours of curing at room temperature. During the curing period, avoid contact with rainwater, chemical media, and mechanical damage to the paint film.

[0023] Due to the application of the above technical solution, the present invention has the following advantages:

[0024] This invention is the first to compound emulsified asphalt, high-temperature resistant resin emulsion, and styrene-butadiene emulsion in a specific ratio to form a complementary film-forming system of "rigidity-flexibility-viscosity," resolving the contradiction of traditional single film-forming substrates being "brittle and prone to cracking at high temperatures" and "not heat-resistant when corrosion-resistant." Emulsified asphalt provides excellent adhesion and sealing properties; its cross-linked polymer chain structure forms a basic barrier layer, preventing the initial penetration of corrosive media. The Si-O bond energy of the water-based silicone resin emulsion is much higher than that of the C-C bonds in ordinary resins, maintaining chemical stability at high temperatures of 230-260℃ and preventing thermal decomposition of the paint film. Simultaneously, its hydrophobic groups (-Si-CH3) reduce the adhesion of condensate to the paint film surface. The butadiene segments of the styrene-butadiene emulsion have good elasticity, alleviating the thermal shrinkage stress of the film-forming system at high temperatures and preventing paint film cracking. Its styrene segments enhance compatibility with other film-forming substrates, forming a uniform and continuous film structure. Furthermore, the active groups (such as silanol groups -Si-OH) in the molecular chains of waterborne silicone resin emulsions undergo dehydration condensation reactions with the hydroxyl (-OH) and carboxyl (-COOH) groups of asphaltenes in emulsified asphalt, forming Si-OC covalent bonds. Simultaneously, the polar groups of the silicone resin form hydrogen bonds with the polar segments of the asphalt molecular chains, causing the molecular chains of the two film-forming substrates to intertwine and cross-link, forming a continuous and stable composite film-forming network. This synergistic effect of the three components gives the coating film both high-temperature stability and crack resistance and sealing properties.

[0025] This invention selects four fillers—silica powder, mica powder, barium sulfate, and fumed silica—and blends them in specific proportions to construct a multifunctional filler system that provides "sheet-like barrier, enhanced activity, and anti-shrinkage," overcoming the limitations of traditional single fillers that can only achieve a single function. The abundant silanol groups on the surface of the silica powder undergo dehydration condensation reactions with the active groups (-OH, -COOH, Si-OH) in the molecular chains of the film-forming substrate (organosilicon resin, emulsified asphalt) to form Si-OC or Si-O-Si covalent bonds. The silanol groups that do not participate in condensation form hydrogen bonds with the substrate molecular chains, further strengthening the interfacial bonding between the filler and the film-forming system. The dual effect of covalent and hydrogen bonds firmly anchors the silica powder in the film-forming network, preventing filler detachment under high temperature or corrosive environments, while significantly improving the adhesion between the coating and the metal substrate. The tight interfacial bonding eliminates voids between the filler and the substrate, reducing the penetration path of corrosive media. Combined with the "maze effect" of the sheet-like filler, this further enhances the anti-dew point corrosion performance.

[0026] Fumed silica, being nano-sized porous particles with a high density of silanol groups on its surface, can undergo multi-point cross-linking reactions with the active groups in the molecular chains of organosilicon resins and styrene-butadiene emulsions, forming a three-dimensional network structure that "locks" the molecular chains of the film-forming substrate within the network. This three-dimensional network structure restricts the thermal movement of the film-forming molecular chains, inhibiting thermal shrinkage of the paint film at high temperatures and preventing cracking. Its filling effect improves the density of the paint film, reducing defects such as pinholes and craters, enhancing its barrier properties against condensate and corrosive media, improving its weather resistance and scratch resistance, and extending the coating's service life. The flake-like surfaces of mica powder and barium sulfate have a certain polarity, allowing them to be tightly adsorbed onto the molecular chains of the film-forming substrate (emulsified asphalt, organosilicon resin) through van der Waals forces, causing the flake-like fillers to overlap and arrange in parallel within the film-forming system. The adhesive effect of the film-forming substrate firmly encapsulates the flake-like fillers, forming a "flake-like filler-resin" composite barrier layer.

[0027] At the same time, the anionic dispersant is adsorbed on the surface of the filler particles to form a double electric layer, which generates electrostatic repulsion between the particles. Meanwhile, its steric hindrance effect can prevent particle agglomeration, ensuring that the filler is uniformly dispersed in the coating and improving the density of the paint film.

[0028] Compared with the prior art, the present invention has the following advantages:

[0029] 1. Excellent synergy between high temperature resistance and dew point corrosion prevention: After baking at 230-260℃ for 12 hours, the paint film surface is smooth, without blistering, cracking, or peeling, and the weight loss upon heating is ≤4%. Through the "labyrinth effect" of the lamellar filler, the chemical inertness of the film-forming system, and strong adhesion, it effectively resists the erosion of condensate and corrosive media, avoids under-film corrosion, and solves the problem of equipment corrosion under high temperature and condensation conditions.

[0030] 2. Environmental protection and safety: It uses water as the dispersion medium and optional diluent, has low VOC content, is non-toxic, non-flammable and non-explosive, and is safe for construction and storage. It meets the requirements of green environmental protection policies and avoids the environmental pollution problems of traditional solvent-based coatings.

[0031] 3. Excellent workability: It can be applied by spraying, brushing, roller coating and other methods to meet the needs of different working conditions; the optimized selection of thickener ensures no sagging during construction, and it is especially suitable for vertical surfaces and side walls; the paint film has a short surface drying time, reasonable curing cycle and high construction efficiency.

[0032] 4. Strong adhesion and stable performance: The adhesion level to sandblasted steel is ≤1, with outstanding wet adhesion. It can maintain strong adhesion even in humid environments or long-term immersion in water. It has excellent resistance to acid, alkali, salt spray and condensation, and has a long service life, which can significantly extend the equipment maintenance cycle and reduce the total life cycle cost.

[0033] Wide range of applications: Suitable for industries such as petrochemical, power, metallurgy, marine, and construction engineering. It can protect metal equipment such as power plant chimneys, flue gas heat exchangers, oil and gas pipelines, storage tanks, and sintering machine flues. It is especially suitable for harsh environments that are prone to condensation, have high temperatures, and contain corrosive media.

[0034] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Detailed Implementation

[0035] To make the present invention more apparent and understandable, preferred embodiments are described in detail below.

[0036] The embodiments involve the addition of various substances, and unless otherwise specified, the term "parts" refers to "parts by weight".

[0037] It should be understood that these embodiments are used to illustrate the basic principles, main features and advantages of the present invention, and the present invention is not limited to the scope of the following embodiments; the implementation conditions used in the embodiments can be further adjusted according to specific requirements, and the implementation conditions not specified are usually the conditions in conventional experiments.

[0038] All the raw materials used in this invention are commercially available and commonly used reagent raw materials.

[0039] Emulsified asphalt, manufactured by Ningbo Sanse Environmental Protection Technology Co., Ltd., model with 60% solid content;

[0040] Water-based silicone resin emulsion, manufactured by Jinhua TuTu New Materials Co., Ltd., product number BL-996;

[0041] Styrene-butadiene emulsion, manufactured by Datong Yujie Chemical Co., Ltd., product code SNL-5042;

[0042] Silicon micro powder, manufactured by Lianyungang Miaojing Silicon Materials Co., Ltd.; product model SG-1010;

[0043] Mica powder, manufactured by Suzhou Guojian Huitou Mineral New Materials Co., Ltd.

[0044] Barium sulfate, manufactured by SABOMAN, product number MWBAR,14A;

[0045] Fumed silica, manufactured by Shandong Aochuang Chemical Co., Ltd., product number 2507F00160

[0046] Thickener, manufactured by Shanghai Boran New Material Technology Co., Ltd.; product number 1203;

[0047] The dispersant is manufactured by Shanghai Boran New Material Technology Co., Ltd.

[0048] The cosolvent is manufactured by Suzhou Kaibei Chemical Co., Ltd., and its product number is dodecyl alcohol ester.

[0049] Anti-flash rust agent, manufactured by Guangzhou Hongxin Chemical Additives Co., Ltd., product number HX-1126;

[0050] The defoamer is manufactured by Shanghai Boran New Material Technology Co., Ltd., and its product number is 1234.

[0051] Example 1

[0052] A water-based high-temperature resistant and dew-point corrosion-resistant coating, by weight, comprises the following raw materials: 210 parts emulsified asphalt, 220 parts organosilicon resin emulsion, 110 parts styrene-butadiene emulsion, 70 parts silica powder, 105 parts mica powder, 70 parts barium sulfate, 7 parts fumed silica, 3.2 parts thickener, 6 parts dispersant, 2.1 parts defoamer, 14 parts cosolvent, 7 parts ammonia, 8 parts flash rust inhibitor, and 2 parts diluent. The preparation method of this coating includes the following steps:

[0053] (1) Pre-dispersion: Add 210 parts of emulsified asphalt, 220 parts of organosilicon resin emulsion and 110 parts of styrene-butadiene emulsion to a mixing tank and stir at 600 r / min for 18 min to ensure that the three film-forming substrates are mixed evenly.

[0054] (2) Addition and dispersion of fillers: Add 70 parts of silica powder, 105 parts of mica powder, 70 parts of barium sulfate and 7 parts of fumed silica to the mixing tank in sequence, increase the speed to 1300 r / min, disperse at high speed for 35 min, and control the material temperature at 30℃ during the dispersion process to avoid filler agglomeration;

[0055] (3) Additives: Adjust the speed to 900 r / min, add 6 parts of dispersant, 2.1 parts of defoamer, 14 parts of cosolvent, and 8 parts of anti-flash rust agent in sequence, stir for 12 min, add 7 parts of ammonia water, continue stirring for 22 min, add thickener, and stir for 15 min;

[0056] (4) Dilution and filtration: Add 5% of the total mass of the coating with dilution water, stir for 12 minutes, and then filter through a 250-mesh filter to remove impurities and incompletely dispersed particles to obtain the finished coating.

[0057] Example 2

[0058] A water-based high-temperature resistant and dew-point corrosion-resistant coating, by weight, comprises the following raw materials: 200 parts emulsified asphalt, 210 parts organosilicon resin emulsion, 100 parts styrene-butadiene emulsion, 60 parts silica powder, 95 parts mica powder, 60 parts barium sulfate, 6 parts fumed silica, 3 parts thickener, 5 parts dispersant, 2 parts defoamer, 13 parts cosolvent, 6 parts ammonia, 7 parts flash rust inhibitor, and 3% diluent.

[0059] Its preparation and construction methods are basically the same as those in Example 1, only the raw material ratio and some process parameters are adjusted: Step (1) The stirring speed is 500 r / min and the stirring time is 20 minutes; Step (2) The stirring speed is 1200 r / min, the dispersion time is 40 minutes, and the material temperature is 25℃; Step (3) The stirring speed is 800 r / min and the stirring time is 15 minutes.

[0060] Example 3

[0061] A water-based high-temperature resistant and dew-point corrosion-resistant coating, by weight, comprises the following raw materials: 220 parts emulsified asphalt, 230 parts organosilicon resin emulsion, 120 parts styrene-butadiene emulsion, 80 parts silica powder, 115 parts mica powder, 80 parts barium sulfate, 8 parts fumed silica, 3.4 parts thickener, 7 parts dispersant, 2.2 parts defoamer, 15 parts cosolvent, 8 parts ammonia, and 9 parts flash rust inhibitor.

[0062] The preparation method is the same as in Example 1: Step (1) The stirring speed is 800 r / min and the stirring time is 15 minutes; Step (2) The stirring speed is 1500 r / min, the dispersion time is 30 minutes, and the material temperature is 35℃; Step (3) The stirring speed is 1000 r / min and the stirring time is 10 minutes.

[0063] The specific method for preparing the paint film is as follows:

[0064] (1) Remove oil and rust from the substrate to achieve St2 grade;

[0065] (2) The ambient temperature during construction shall be controlled at 25℃;

[0066] (3) Air spraying is used, with nozzles of 3 mm or more and air pressure of 0.4 MPa;

[0067] (4) When spraying, keep the spray gun at a 90° angle to the surface to be coated, and keep the distance between the spray gun and the surface to be coated constant and at a uniform speed. To ensure that the paint film is completely dry, spray in multiple coats. After each coat, cure at room temperature for 6 hours. After the required thickness is reached, cure at room temperature for 8 hours for the last coat. The high temperature resistant and dew point corrosion resistant paint film coating is obtained.

[0068] The performance of the water-based high-temperature resistant and dew-point corrosion-resistant coatings prepared in Examples 1-3 was tested. The testing standards were based on GB / T 16777-2008 "Test Methods for Waterproof Coatings for Buildings" and relevant industry standards. The results are shown in the table below:

[0069] Table 1 Physical property test of water-based high-temperature resistant and dew-point corrosion-resistant coatings

[0070] Serial Number Testing items Technical Requirements Example 1 Example 2 Example 3 1 State in the container A viscous fluid, free of lumps, and easy to stir evenly. conform to conform to conform to 2 Fineness (μm) ≤70 70 68 65 3 Specific gravity (g / ml) 1.1±0.1 1.096 1.08 1.10 4 Non-volatile matter (%) ≥55 61 60 62 5 Drying time (h) ≤2 0.5 0.6 0.4 6 Anti-sagging properties (wet film, μm) ≥475 525 530 540 7 Adhesion (Grade) ≤1 0 0 0 8 Acid resistance (30% sulfuric acid, 12h) No bubbling, no peeling, no rusting conform to conform to conform to 9 Heat resistance (250℃, 12h) It does not bubble, peel, or crack; its weight loss upon heating is ≤4%. Yes, weight loss is 0.5%. Yes, weight loss is 0.6%. Yes, weight loss is 0.4%.

[0071] The test results show that the water-based high-temperature resistant and dew-point corrosion-resistant coatings prepared in Examples 1-3 of this invention meet all technical requirements, and some indicators are even better than the standards. They have excellent high-temperature resistance, dew-point corrosion resistance, adhesion and construction performance, and are environmentally friendly and safe. They can be widely used for the protection of various metal equipment.

[0072] In addition, after testing, the water-based high-temperature resistant and dew point corrosion-resistant coatings prepared in Examples 1-3 have a viscosity between 2000-2500 mPa·S (at 25°C). The coatings have good fluidity and will not cause nozzle clogging. They can be sprayed at room temperature.

[0073] When spraying, the air pressure should ideally be controlled between 0.3-0.4 MPa. The spray gun can be moved up and down and left and right, preferably at a uniform speed of 10-12 meters per minute. The nozzle should be held perpendicular to the surface, minimizing angled spraying. When spraying the ends of the surface, quickly release the trigger to reduce the mist. Each coat should overlap the previous coat by 1 / 3 or 1 / 4 to avoid missed areas.

[0074] The above description is merely an example of the embodiments of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A water-based high-temperature resistant and dew-point corrosion-resistant coating, characterized in that, By weight, the raw material composition includes: 200-220 parts emulsified asphalt, 210-230 parts high-temperature resistant resin emulsion, 100-120 parts styrene-butadiene emulsion, 60-80 parts silica powder, 95-115 parts mica powder, 60-80 parts barium sulfate, 6-8 parts fumed silica, 3-3.4 parts thickener, 5-7 parts dispersant, 2-2.2 parts defoamer, 13-15 parts film-forming agent, 6-8 parts ammonia water, 7-9 parts flash rust inhibitor, and 0-5 parts diluent.

2. The water-based high-temperature resistant and dew-point corrosion-resistant coating according to claim 1, characterized in that, The high-temperature resistant resin emulsion is at least one of water-based silicone resin emulsion and water-based epoxy resin.

3. The water-based high-temperature resistant and dew-point corrosion-resistant coating according to claim 1, characterized in that, The film-forming agent is at least one of dodecyl alcohol ester, hexadecyl alcohol ester, and ethylene glycol butyl ether acetate.

4. The water-based high-temperature resistant and dew-point corrosion-resistant coating according to claim 1, characterized in that, The defoamer is at least one of silicone or polyether defoamers.

5. The water-based high-temperature resistant and dew-point corrosion-resistant coating according to claim 1, characterized in that, The diluent is at least one of water or deionized water.

6. A method for preparing a water-based high-temperature resistant and dew-point corrosion-resistant coating as described in any one of claims 1-4, characterized in that, Includes the following steps: (1) Pre-dispersion: Emulsified asphalt, organosilicon resin emulsion and styrene-butadiene emulsion are added to the mixing tank at the same ratio and stirred at 500-800 r / min for 15-20 min until they are evenly mixed; (2) Addition and dispersion of fillers: Add silica powder, mica powder, barium sulfate and fumed silica in sequence, increase the rotation speed to 1200-1500 r / min, disperse at high speed for 30-40 min, and control the material temperature at 25-35℃ during the dispersion process; (3) Additives: Adjust the speed to 800-1000 r / min, add dispersant, defoamer, solubilizer and anti-flash rust agent in sequence, stir for 10-15 min, add ammonia water, continue stirring for 20-25 min, add thickener, and stir for 10-15 min; (4) Dilution and filtration: Add 0-5% dilution water according to construction requirements, stir for 10-15 minutes, and then filter through a 200-300 mesh filter to remove impurities and incompletely dispersed particles to obtain the finished coating.

7. A method for applying a water-based high-temperature resistant anti-dew-point corrosion coating as described in any one of claims 1-6, characterized in that, Includes the following steps: (a) Substrate treatment: Remove loose paint, dirt, grease, mold and other contaminants from the surface of the metal substrate. Sandblast the metal surface to Sa2.0 grade or manually treat it to St2 grade, with the roughness controlled at 5-70 micrometers. (b) Construction environment control: The construction temperature should be 5-45℃; (c) Coating method: spraying, brushing, roller coating or airless spraying. For air spraying, use nozzles with a diameter of 3 mm or more and an air pressure of 4-7 kg; for airless spraying, use nozzles with a diameter of 0.64-0.89 mm, a spray width of 30-60 cm and a spraying pressure of 16-20 MPa. (d) Number of coating coats and intervals: Apply 3-6 coats in total, with an interval of 4-6 hours between each coat. Ensure that the previous coat is completely dry and free of drips before applying the next coat. The wet film thickness of a single spray is ≥1000 micrometers, and the total dry film thickness is ≥2000 μm. (e) Curing and hardening: Curing at room temperature for 4-6 hours per pass, with the last pass being cured at room temperature for 8 hours.