A super-soft anti-corrosion solvent-free polyester coating and its preparation method

Abstract

The present invention relates to the technical field of coatings, and discloses a super-soft anti-corrosion solvent-free polyester coating and a preparation method thereof. The solvent-free polyester coating of the present invention comprises component A and component B; wherein, component A comprises a modified polyester polyol, a polycarbonate diol, a modified silicone, a catalyst, an auxiliary agent and an inorganic filler; component B is polymethylene polyphenyl polyisocyanate; the solvent-free polyester coating prepared by the present invention has an ultra-high solid content, the coating thickness can be accurately controlled, the reaction film-forming speed is fast, the top and bottom are integrated, and at the same time has super-strong flexibility, and has good adhesion and corrosion resistance to the substrate.

Description

Technical Field

[0001] The present invention relates to the technical field of coatings, and particularly relates to a super-flexible anti-corrosion solvent-free polyester coating and a preparation method thereof. Background Art

[0002] The protection of metal corrosion has important protective significance and economic value in aspects such as national defense, aerospace, petroleum, chemical industry, and civil construction. The corrosion of metal materials in the atmospheric environment is the most common existence in nature, especially in some environments with high temperature, high humidity, high salinity / alkalinity. Usually, the protection measure is to coat the paint on the surface of the object to be protected or decorated, and a continuous film that can firmly adhere to the coated object can be formed. At present, China has put forward higher requirements for the anti-corrosion systems and materials of traditional thermal insulation and oil pipelines, requiring ultra-high solid content, construction not affected by environmental temperature, good acid, alkali, and salt resistance, excellent flexibility, significant high-temperature resistance, good flexibility, impact resistance, and chemical corrosion resistance, so that the solvent-free anti-corrosion materials develop in the direction of high efficiency, easy application, and green preparation process.

[0003] However, the existing two-component solvent-free ultra-high solid content has a very limited anti-corrosion effect on the outer wall of external metal pipelines in high-temperature and high-salinity areas. The main reason is its poor flexibility, easy cracking, and poor adhesion on smooth galvanized surfaces, residual paint surfaces, etc. Therefore, HK Company has developed an anti-corrosion coating with a high solid content, good flexibility, excellent corrosion resistance, and excellent adhesion. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a super-flexible anti-corrosion solvent-free polyester coating and a preparation method thereof.

[0005] The object of the present invention can be achieved by the following technical solutions:

[0006] A super-flexible anti-corrosion solvent-free polyester coating, comprising component A and component B, and the mass ratio of component A to component B is 100:35 - 45;

[0007] Component A comprises raw materials in the following mass percentages: 30.0wt% - 40.0wt% modified polyester polyol, 8.0wt% - 15.0wt% polycarbonate diol, 5.0wt% - 10.0wt% modified silicone, 0.5wt% - 1.5wt% catalyst, 5.0wt% - 10.0wt% auxiliary agent, 35.0wt% - 50.0wt% inorganic filler;

[0008] Component B is polymethylene polyphenyl isocyanate;

[0009] Further, the isocyanate group content in the polymethylene polyphenyl isocyanate is 32% - 36%;

[0010] Further, the additives include 1.0wt% - 2.5wt% dispersant, 0.7wt% - 2.0wt% defoamer, 1.5wt% - 3.0wt% water remover, 0.3wt% - 0.5wt% light stabilizer, and 1.5wt% - 2.0wt% didecyl phthalate;

[0011] Further, the inorganic filler includes 15wt% - 20wt% aluminosilicate, 7wt% - 12wt% potassium feldspar, 5wt% - 10wt% quartz powder, 2wt% - 6wt% barium sulfate, and 2 - 5wt% modified zinc phosphate;

[0012] The modified silicone is prepared by the following steps:

[0013] Step A1: Stir dopamine hydrochloride and dibutyltin dilaurate evenly in ethanol, slowly drop allyl isothiocyanate under stirring conditions, and react at 45 - 55 °C for 3 - 5 h. Then, carry out vacuum filtration, washing, and drying to obtain the dopamine derivative;

[0014] Further, in step A1, the molar ratio of dopamine hydrochloride, dibutyltin dilaurate, and allyl isothiocyanate is 0.05 - 0.15:0.0003 - 0.001:0.05 - 0.15;

[0015] Step A2: Mix 1 - hydroxyethyl - 2 - methylimidazole evenly in tetrahydrofuran, add triethylamine, and stir for 10 min under nitrogen conditions. Then, slowly add allylphosphine dichloride in an ice - water bath, and react at room temperature for 2 h and at 40 °C for 6 h in sequence. Carry out suction filtration, rotary evaporation, washing, and drying to obtain the phosphate - imidazole product;

[0016] Further, in step A2, the molar ratio of 1 - hydroxyethyl - 2 - methylimidazole, allylphosphine dichloride, and triethylamine is 0.01 - 0.03:0.006 - 0.018:0.015 - 0.045;

[0017] Step A3: Mix the phosphate - imidazole product, γ - mercaptopropyltrimethoxysilane, and benzoin dimethyl ether evenly and stir. Irradiate under ultraviolet light for 25 - 45 min, add n - hexane for precipitation, and filter and dry to obtain the functionalized siloxane;

[0018] Further, in step A3, the dosage ratio of the phosphate - imidazole product, γ - mercaptopropyltrimethoxysilane, benzoin dimethyl ether, and n - hexane is 0.18 - 0.54 mol:0.185 - 0.555 mol:0.007 - 0.021 g:300 mL;

[0019] Step A4: Mix dimethyldimethoxysilane, functionalized siloxane, tetramethyldihydrodisiloxane and trifluoromethanesulfonic acid, and then stir and react at 25°C under nitrogen for 24 h. Add anhydrous sodium bicarbonate and stir for 1 h, then add anhydrous sodium sulfate and stir for 1 h. Filter, rotary evaporate, and vacuum dry to collect the terminal hydrogen-functionalized organosilicon. Then add 0.2 - 0.4 mg / mL of chloroplatinic acid isopropanol solution thereto, stir and heat to 80°C, and then add the dopamine derivative and react for 3 - 5 h. Stop introducing nitrogen and perform vacuum distillation to obtain the modified organosilicon;

[0020] Further, in step A4, the molar ratio of dimethyldimethoxysilane, functionalized siloxane and tetramethyldihydrodisiloxane is 0.02 - 0.04:0.003 - 0.006:0.01 - 0.015;

[0021] Further, the trifluoromethanesulfonic acid in step A4 accounts for 0.3 wt% - 0.5 wt% of the total amount of reactants;

[0022] Further, the anhydrous sodium bicarbonate in step A4 accounts for 20 wt% - 40 wt% of the total amount of reactants;

[0023] Further, the anhydrous sodium sulfate in step A4 accounts for 30 wt% - 50 wt% of the total amount of reactants;

[0024] Further, in step A4, the molar ratio of the dopamine derivative to tetramethyldihydrodisiloxane is 2:1;

[0025] Further, the chloroplatinic acid isopropanol solution in step A4 accounts for 2 wt% - 3 wt% of the total amount of the terminal hydrogen-functionalized organosilicon and the dopamine derivative.

[0026] A preparation method of a super-soft anti-corrosion solvent-free polyester coating comprises the following steps:

[0027] Step S1: Weigh the raw materials by mass percentage. Stir the modified polyester polyol and polycarbonate diol evenly at 40 - 60°C, add the modified organosilicon, catalyst, dispersant, defoamer, water remover, light stabilizer and dioctyl phthalate and stir for 15 - 25 min, then add aluminosilicate, potassium feldspar, quartz powder, barium sulfate and modified zinc phosphate and mix and stir evenly to obtain component A;

[0028] Step S2: Weigh component A and polymethylene polyphenyl isocyanate of component B according to the mass ratio of 100:35 - 45, and mix component A and component B to obtain the super-soft anti-corrosion solvent-free polyester coating.

[0029] Advantages of the present invention:

[0030] The solvent-free polyester coating prepared by the present invention has an ultra-high solid content, the coating thickness can be accurately controlled, the film-forming reaction speed is fast, the top and bottom are integrated, and it has super flexibility and good adhesion to the substrate.

[0031] After the solvent-free polyester coating prepared by the present invention forms a film, the coating has excellent chemical stability and can effectively prevent the penetration of corrosion media such as water vapor, acids, and alkalis.

[0032] Modified silicone containing phosphate groups, thiourea groups, catechol structures, and imidazole structures is also introduced into the solvent-free polyester coating prepared by the present invention. They act synergistically to improve the flexibility, adhesion, and corrosion resistance of the coating after film formation. Among them, the phosphate groups and thiourea groups can form stable compounds through chemical bonding with the surface of the metal pipeline, improving the adhesion and corrosion resistance of the coating to the metal surface; the catechol structure forms strong coordination bonds or hydrogen bonds with the metal surface through the ortho-phenolic hydroxyl group, and at the same time its polyphenol structure can produce multiple adsorption effects, further enhancing the interfacial adhesion; the nitrogen atom in the imidazole ring can catalyze the reaction of isocyanate and hydroxyl groups in the coating, promoting complete curing and forming a denser coating. At the same time, imidazole itself has a corrosion inhibition effect and can be adsorbed on the metal surface to inhibit corrosion. In addition, the main chain -Si-O-Si- segment of the modified silicone has high flexibility, which can reduce the glass transition temperature (Tg) of the coating, endow the coating with better elasticity, and adapt to the deformation of the metal pipeline caused by temperature or stress. Detailed implementation manners

[0033] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0034] The sources of some raw materials used in the following examples are as follows:

[0035] Modified polyester polyol resin: Waxfu (Shanghai) New Materials Co., Ltd., the hydroxyl value of the resin is 260 - 290mgKOH / g, the functionality is 3.6, and the water content < 0.1%.

[0036] Polycarbonate diol: Shanghai Shuyu Chemical Co., Ltd., product brand SYH1000, hydroxyl value is 102 - 118mgKOH / g, water content < 0.1%.

[0037] Dispersant: Polyester-based dispersant produced by BYK Chemie GmbH, product named DISPERBYK-163.

[0038] Defoamer: A non-silicon defoamer produced by BYK Chemie GmbH, with the product name BYK-A501.

[0039] Water remover: A molecular sieve water remover produced by Chengsong International Trade (Shanghai) Co., Ltd., with the product name SYLOSIVE A3.

[0040] Light stabilizer: Light stabilizer HS-508 is selected.

[0041] Example 1: The modified silicone is prepared by the following steps:

[0042] Step A1: 0.05 mol of dopamine hydrochloride and 0.0003 mol of dibutyltin dilaurate are stirred evenly in ethanol. Under stirring conditions, 0.05 mol of allyl isothiocyanate is slowly added dropwise, and the reaction is carried out at 45 °C for 3 h. Then, it is filtered under reduced pressure, washed, and dried to obtain the dopamine derivative.

[0043] Step A2: 0.01 mol of 1-hydroxyethyl-2-methylimidazole is mixed evenly in tetrahydrofuran. 0.015 mol of triethylamine is added and stirred for 10 min under nitrogen conditions. Then, 0.006 mol of allylphosphine dichloride is slowly added under an ice-water bath, and the reaction is carried out at room temperature for 2 h and at 40 °C for 6 h in sequence. It is filtered by suction, rotary evaporated, washed, and dried to obtain the phosphate-imidazole product.

[0044] Step A3: 0.18 mol of the phosphate-imidazole product, 0.185 mol of γ-mercaptopropyltrimethoxysilane, and 0.007 g of benzoin dimethyl ether are mixed and stirred evenly. It is irradiated under ultraviolet light for 25 min, 300 mL of n-hexane is added for precipitation, and then it is filtered and dried to obtain the functionalized siloxane.

[0045] Step A4: 0.02 mol of dimethyldimethoxysilane, 0.003 mol of the functionalized siloxane, 0.01 mol of tetramethyldihydrodisiloxane, and trifluoromethanesulfonic acid (accounting for 0.3 wt% of the total amount of reactants) are mixed, and then stirred and reacted at 25 °C under nitrogen for 24 h. Anhydrous sodium bicarbonate (accounting for 20 wt% of the total amount of reactants) is added and stirred for 1 h, and anhydrous sodium sulfate (30 wt%) is added and stirred for 1 h. It is filtered, rotary evaporated, and vacuum dried to collect the terminal hydrogen-functionalized silicone. Then, 0.2 mg / mL of chloroplatinic acid isopropyl alcohol solution (accounting for 3 wt% of the total amount of the terminal hydrogen-functionalized silicone and the dopamine derivative) is added, and it is stirred and heated to 80 °C. Then, the dopamine derivative (the molar ratio of the dopamine derivative to tetramethyldihydrodisiloxane is 2:1) is added and reacted for 3 h. The nitrogen supply is stopped, and it is distilled under reduced pressure to obtain the modified silicone.

[0046] Example 2: The modified silicone is prepared by the following steps:

[0047] Step A1: Stir 0.1 mol of dopamine hydrochloride and 0.0006 mol of dibutyltin dilaurate evenly in ethanol. Slowly dropwise add 0.1 mol of allyl isothiocyanate under stirring conditions, and react at 50 °C for 4 h. Then perform suction filtration, washing, and drying to obtain the dopamine derivative;

[0048] Step A2: Mix 0.02 mol of 1 - hydroxyethyl - 2 - methylimidazole evenly in tetrahydrofuran. Add 0.03 mol of triethylamine and stir for 10 min under nitrogen conditions. Then slowly add 0.0012 mol of allylphosphine dichloride in an ice - water bath, and react at room temperature for 2 h and at 40 °C for 6 h in sequence. Then perform suction filtration, rotary evaporation, washing, and drying to obtain the phosphate - imidazole product;

[0049] Step A3: Stir 0.36 mol of the phosphate - imidazole product, 0.37 mol of γ - mercaptopropyltrimethoxysilane, and 0.014 g of benzoin dimethyl ether evenly. Irradiate under ultraviolet light for 35 min, add 300 mL of n - hexane for precipitation, then filter and dry to obtain the functionalized siloxane;

[0050] Step A4: Mix 0.03 mol of dimethyldimethoxysilane, 0.0045 mol of the functionalized siloxane, 0.012 mol of tetramethyldihydrodisiloxane, and trifluoromethanesulfonic acid (accounting for 0.4 wt% of the total amount of reactants). Then stir and react at 25 °C under nitrogen for 24 h. Add anhydrous sodium bicarbonate (accounting for 30 wt% of the total amount of reactants) and stir for 1 h, then add anhydrous sodium sulfate (40 wt%) and stir for 1 h. Filter, perform rotary evaporation, and vacuum dry to collect the terminal - hydrogen - functionalized organosilicon. Then add a 0.3 mg / mL solution of chloroplatinic acid isopropanol (accounting for 2.5 wt% of the total amount of the terminal - hydrogen - functionalized organosilicon and the dopamine derivative) thereto, and stir and heat to 80 °C. Then add the dopamine derivative (the molar ratio of the dopamine derivative to tetramethyldihydrodisiloxane is 2:1) and react for 4 h. Stop passing nitrogen and perform vacuum distillation to obtain the modified organosilicon.

[0051] Example 3: The modified organosilicon is prepared by the following steps:

[0052] Step A1: Stir 0.15 mol of dopamine hydrochloride and 0.001 mol of dibutyltin dilaurate evenly in ethanol. Slowly dropwise add 0.15 mol of allyl isothiocyanate under stirring conditions, and react at 55 °C for 5 h. Then perform suction filtration, washing, and drying to obtain the dopamine derivative;

[0053] Step A2: Mix 0.03 mol of 1-hydroxyethyl-2-methylimidazole evenly in tetrahydrofuran, add 0.045 mol of triethylamine and stir for 10 min under nitrogen condition, then slowly add 0.018 mol of allylphosphine dichloride in an ice-water bath, and react successively at room temperature for 2 h and at 40 °C for 6 h. Then, perform suction filtration, rotary evaporation, washing, and drying to obtain the phosphate-imidazole product;

[0054] Step A3: Mix 0.54 mol of the phosphate-imidazole product, 0.555 mol of γ-mercaptopropyltrimethoxysilane, and 0.021 g of benzoin dimethyl ether evenly, irradiate under ultraviolet light for 45 min, add 300 mL of n-hexane for precipitation, filter, and dry to obtain the functionalized siloxane;

[0055] Step A4: Mix 0.04 mol of dimethyldimethoxysilane, 0.006 mol of the functionalized siloxane, 0.015 mol of tetramethyldihydrodisiloxane, and trifluoromethanesulfonic acid (0.5 wt% of the total amount of reactants), then stir and react at 25 °C under nitrogen for 24 h. Add anhydrous sodium bicarbonate (40 wt% of the total amount of reactants) and stir for 1 h, then add anhydrous sodium sulfate (50 wt%) and stir for 1 h. Filter, perform rotary evaporation, and vacuum dry to collect the terminal hydrogen-functionalized organosilicon. Then, add 0.4 mg / mL of chloroplatinic acid isopropanol solution (2 wt% of the total amount of the terminal hydrogen-functionalized organosilicon and the dopamine derivative), stir and heat to 80 °C, and then add the dopamine derivative (the molar ratio of the dopamine derivative to tetramethyldihydrodisiloxane is 2:1) and react for 5 h. Stop passing nitrogen and perform vacuum distillation to obtain the modified organosilicon.

[0056] Example 4: A preparation method of a super-soft anti-corrosion solvent-free polyester coating comprises the following steps:

[0057] Component A: 30.0 wt% of modified polyester polyol, 10.0 wt% of polycarbonate diol, 5.0 wt% of the modified organosilicon prepared in Example 1, 0.5 wt% of catalyst, 9.0 wt% of additives, 45.5 wt% of inorganic fillers; wherein, additives: 2.0 wt% of dispersant, 2.0 wt% of defoamer, 2.5 wt% of water remover, 0.5 wt% of light stabilizer, and 2.0 wt% of didecyl phthalate; inorganic fillers: 19.0 wt% of aluminosilicate, 10.0 wt% of potassium feldspar, 9.0 wt% of quartz powder, 4.5 wt% of barium sulfate, and 3.0 wt% of modified zinc phosphate;

[0058] Step S1: Weigh the raw materials by mass percentage. Stir the modified polyester polyol and polycarbonate diol evenly at 40°C, add the modified silicone prepared in Example 1, catalyst, dispersant, defoamer, water remover, light stabilizer and dioctyl phthalate, and stir for 15 minutes. Then add aluminosilicate, potassium feldspar, quartz powder, barium sulfate and modified zinc phosphate and mix and stir evenly to obtain Component A.

[0059] Step S2: Weigh Component A and polymethylene polyphenyl isocyanate of Component B according to a mass ratio of 100:35. Mix Component A and Component B to obtain the super-soft anti-corrosion solvent-free polyester coating.

[0060] Example 5: A preparation method of a super-soft anti-corrosion solvent-free polyester coating includes the following steps:

[0061] Component A: 32.5 wt% modified polyester polyol, 12.0 wt% polycarbonate diol, 7.5 wt% modified silicone prepared in Example 2, 1.0 wt% catalyst, 7.0 wt% additives, 40.0 wt% inorganic fillers; among them, additives: 1.5 wt% dispersant, 1.1 wt% defoamer, 2.5 wt% water remover, 0.4 wt% light stabilizer and 1.5 wt% dioctyl phthalate; inorganic fillers: 17.0 wt% aluminosilicate, 12.0 wt% potassium feldspar, 6.5 wt% quartz powder, 2.0 wt% barium sulfate and 2.5 wt% modified zinc phosphate;

[0062] Step S1: Weigh the raw materials by mass percentage. Stir the modified polyester polyol and polycarbonate diol evenly at 50°C, add the modified silicone prepared in Example 2, catalyst, dispersant, defoamer, water remover, light stabilizer and dioctyl phthalate, and stir for 20 minutes. Then add aluminosilicate, potassium feldspar, quartz powder, barium sulfate and modified zinc phosphate and mix and stir evenly to obtain Component A.

[0063] Step S2: Weigh Component A and polymethylene polyphenyl isocyanate of Component B according to a mass ratio of 100:40. Mix Component A and Component B to obtain the super-soft anti-corrosion solvent-free polyester coating.

[0064] Example 6: A preparation method of a super-soft anti-corrosion solvent-free polyester coating includes the following steps:

[0065] 40.0 wt% modified polyester polyol, 8.0 wt% polycarbonate diol, 9.0 wt% modified silicone prepared in Example 3, 1.5 wt% catalyst, 5.0 wt% additives, 36.5 wt% inorganic filler; among them, additives: 1.0 wt% dispersant, 0.7 wt% defoamer, 1.5 wt% water scavenger, 0.3 wt% light stabilizer and 1.5 wt% didecyl phthalate; inorganic filler: a mixture of 15.5 wt% aluminosilicate, 7.0 wt% potassium feldspar, 5.0 wt% quartz powder, 6.0 wt% barium sulfate and 3.0 wt% modified zinc phosphate;

[0066] Step S1: Weigh the raw materials according to the mass percentages. Stir the modified polyester polyol and polycarbonate diol evenly at 60 °C, add the modified silicone prepared in Example 3, catalyst, dispersant, defoamer, water scavenger, light stabilizer and didecyl phthalate and stir for 25 min, then add aluminosilicate, potassium feldspar, quartz powder, barium sulfate and modified zinc phosphate and mix and stir evenly to obtain Component A;

[0067] Step S2: Weigh Component A and polymethylene polyphenyl isocyanate of Component B according to the mass ratio of 100:45. Mix Component A and Component B to obtain the super-soft anti-corrosion solvent-free polyester coating.

[0068] Comparative Example 1: This comparative example is a solvent-free polyester coating. The difference from Example 6 is that a commercially available silicone is used instead of the modified silicone prepared in Example 3, and the rest are the same.

[0069] Comparative Example 2: This comparative example is a solvent-free polyester coating. The difference from Example 6 is that polycarbonate diol is used instead of the modified silicone prepared in Example 3, and the rest are the same.

[0070] Perform performance tests on the solvent-free polyester coatings prepared in Examples 4 - 6 and Comparative Examples 1 - 2:

[0071] Adhesion test: Refer to the SY / T 6854-2012 standard. After coating the solvent-free polyester coating on the surface of the cleaned steel pipe to form a film, conduct the adhesion test at 20 °C ± 2 °C, and the standard is ≥15 MPa;

[0072] Corrosion resistance test: Refer to the GB / T 1763 standard. Conduct the corrosion resistance test on the steel pipe coated with the coating in 10 wt% sulfuric acid solution, 10 wt% sodium hydroxide solution and 3 wt% sodium chloride solution, and observe whether there are bubbles or peeling on the surface of the coating;

[0073] Flexibility test: Refer to the SY / T 6854-2012 standard. Bend the steel pipe coated with the coating at -20 °C ± 3 °C by 1.5°, and observe whether there are cracks or leakage points on the surface of the coating on the steel pipe;

[0074] The test results are shown in Table 1 as follows:

[0075] Table 1: Performance Test Results

[0076]

[0077] As can be seen from Table 1, the solvent-free polyester coating prepared by the present invention, when applied to the surface of metal pipes, has excellent adhesion, flexibility and corrosion resistance.

[0078] The above content is only an example and illustration of the concept of the present invention. Those skilled in the art of this technology can make various modifications or supplements to the specific embodiments described, or use similar methods for substitution, as long as they do not deviate from the scope defined by the concept of the invention, they should fall within the protection scope of the present invention.

Claims

1. A super-soft anti-corrosion solvent-free polyester coating, characterized in that, It includes component A and component B, and the mass ratio of component A to component B is 100:35 - 45; Component A includes raw materials with the following mass percentages: 30.0wt% - 40.0wt% modified polyester polyol, 8.0wt% - 15.0wt% polycarbonate diol, 5.0wt% - 10.0wt% modified silicone, 0.5wt% - 1.5wt% catalyst, 5.0wt% - 10.0wt% auxiliary agent, 35.0wt% - 50.0wt% inorganic filler; Component B is polymethylene polyphenyl isocyanate; The modified silicone is prepared by reacting a hydrogen-terminated functionalized silicone with a dopamine derivative. The hydrogen-terminated functionalized silicone is prepared by reacting dimethyldimethoxysilane, a functionalized siloxane, and tetramethyldihydrodisiloxane. The functionalized siloxane is prepared by reacting a phosphate-imidazole product with γ-mercaptopropyltrimethoxysilane. The phosphate-imidazole product is prepared by reacting 1-hydroxyethyl-2-methylimidazole with allyl dichlorophosphate. The dopamine derivative is prepared by reacting dopamine hydrochloride with allyl isothiocyanate.

2. The super-soft anti-corrosion solvent-free polyester coating according to claim 1, characterized in that The modified silicone is prepared by the following steps: Step A1: Stir dopamine hydrochloride and dibutyltin dilaurate evenly in ethanol. Slowly dropwise add allyl isothiocyanate under stirring conditions, and react at 45 - 55°C for 3 - 5 h. Filter under reduced pressure, wash, and dry to obtain the dopamine derivative; Step A2: Mix 1-hydroxyethyl-2-methylimidazole evenly in tetrahydrofuran. Add triethylamine and stir for 10 min under nitrogen conditions. Then slowly add allyl dichlorophosphate in an ice-water bath, and react at room temperature for 2 h and at 40°C for 6 h in sequence. Filter, rotary evaporate, wash, and dry to obtain the phosphate-imidazole product; Step A3: Mix the phosphate-imidazole product, γ-mercaptopropyltrimethoxysilane, and benzoin dimethyl ether evenly and stir. Irradiate under ultraviolet light for 25 - 45 min. Add n-hexane for precipitation, filter, and dry to obtain the functionalized siloxane; Step A4: After mixing dimethyldimethoxysilane, the functionalized siloxane, tetramethyldihydrodisiloxane, and trifluoromethanesulfonic acid, stir and react at 25°C under nitrogen for 24 h. Add anhydrous sodium bicarbonate and stir for 1 h, then add anhydrous sodium sulfate and stir for 1 h. Filter, rotary evaporate, and vacuum dry to collect the hydrogen-terminated functionalized silicone. Then add a 0.2 - 0.4 mg / mL solution of chloroplatinic acid in isopropanol thereto, stir and heat to 80°C, and then add the dopamine derivative and react for 3 - 5 h. Stop introducing nitrogen and distill under reduced pressure to obtain the modified silicone.

3. The super-soft anti-corrosion solvent-free polyester coating according to claim 2, characterized in that, In step A1, the molar ratio of dopamine hydrochloride, dibutyltin dilaurate, and allyl isothiocyanate is 0.05 - 0.15:0.0003 - 0.001:0.05 - 0.

15.

4. The super-soft anti-corrosion solvent-free polyester coating according to claim 2, characterized in that, In step A2, the molar ratio of 1-hydroxyethyl-2-methylimidazole, allyl dichlorophosphate, and triethylamine is 0.01 - 0.03:0.006 - 0.018:0.015 - 0.

045.

5. The super-soft anti-corrosion solvent-free polyester coating according to claim 2, characterized in that, In step A3, the dosage ratio of the phosphate-imidazole product, γ-mercaptopropyltrimethoxysilane, benzoin dimethyl ether and n-hexane is 0.18 - 0.54 mol: 0.185 - 0.555 mol: 0.007 - 0.021 g: 300 mL.

6. The super-flexible anti-corrosion solvent-free polyester coating according to claim 2, wherein, In step A4, the molar ratio of dimethyldimethoxysilane, functionalized siloxane and tetramethyldihydrodisiloxane is 0.02 - 0.04: 0.003 - 0.006: 0.01 - 0.

015. The trifluoromethanesulfonic acid, anhydrous sodium bicarbonate and anhydrous sodium sulfate respectively account for 0.3 wt% - 0.5 wt%, 20 wt% - 40 wt% and 30 wt% - 50 wt% of the total amount of the reactants. The molar ratio of the dopamine derivative and tetramethyldihydrodisiloxane is 2:

1. The chloroplatinic acid isopropanol solution accounts for 2 wt% - 3 wt% of the total amount of the terminal hydrogen-functionalized organosilicon and the dopamine derivative.

7. The super-soft anti-corrosion solvent-free polyester coating according to claim 1, characterized in that The isocyanate group content in the polymethylene polyphenyl isocyanate is 32% - 36%.

8. The super-soft anti-corrosion solvent-free polyester coating according to claim 1, characterized in that, The auxiliary agents include 1.0 wt% - 2.5 wt% dispersant, 0.7 wt% - 2.0 wt% defoamer, 1.5 wt% - 3.0 wt% water remover, 0.3 wt% - 0.5 wt% light stabilizer and 1.5 wt% - 2.0 wt% didecyl phthalate.

9. The super-soft anti-corrosion solvent-free polyester coating according to claim 1, characterized in that, The inorganic fillers include 15 wt% - 20 wt% aluminosilicate, 7 wt% - 12 wt% potassium feldspar, 5 wt% - 10 wt% quartz powder, 2 wt% - 6 wt% barium sulfate and 2 - 5 wt% modified zinc phosphate.

10. A method for preparing the super-soft anti-corrosion solvent-free polyester coating according to any one of claims 1-9, characterized in that, It includes the following steps: Step S1: Weigh the raw materials by mass percentage. Stir the modified polyester polyol and polycarbonate diol evenly at 40 - 60 °C, add the modified organosilicon, catalyst, dispersant, defoamer, water remover, light stabilizer and didecyl phthalate and stir for 15 - 25 min, then add aluminosilicate, potassium feldspar, quartz powder, barium sulfate and modified zinc phosphate and mix and stir evenly to obtain component A. Step S2: Weigh component A and polymethylene polyphenyl isocyanate of component B according to the mass ratio of 100: 35 - 45. Mix component A and component B to obtain the super-soft anti-corrosion solvent-free polyester coating.

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