High-temperature-resistant polyurethane coating and preparation method thereof

Abstract

The invention relates to the technical field of high-temperature-resistant coatings, in particular to a high-temperature-resistant polyurethane coating and a preparation method thereof. The coating comprises polyurethane, a functional additive and an inorganic filler. The polyurethane is obtained by copolymerizing a polyisocyanate monomer, branched polyol and ethylene glycol, and is self-repairing polyurethane with a three-dimensional network structure; the sulfonate type waterborne polyurethane diamine is adopted for chain extension, and a polyamine group and a sulfonic acid group are introduced, so that the polyurethane is endowed with flexibility and flowability, and the freeze-thaw stability, the storage stability, the antistatic property and the like of the polyurethane are improved; the functional additive is fullerene, so that the glass transition temperature is increased, and the high temperature resistance is improved; the inorganic filler is aluminum silicate, so that the impact resistance and wear resistance of the coating can be improved. The coating has excellent high temperature resistance, water resistance and wear resistance, and is suitable for surface coating of products such as buildings, automobiles, ships, wood and leather.

Description

Technical Field

[0001] The present invention relates to the technical field of high-temperature resistant coatings, and particularly relates to a high-temperature resistant polyamine-based polyurethane coating and a preparation method thereof. Background Art

[0002] Polyurethane coatings are prepared from polyurethane and various additives, and have excellent properties such as stability and chemical corrosion resistance, and are widely used in fields such as construction, automobiles, furniture, electronics, ships, and aviation.

[0003] Through research, it has been found that introducing segments or groups with amide or imide into polyurethane can effectively improve the water resistance, flexibility, impact resistance, tensile strength, and wear resistance of polyurethane. Amines or imides can crosslink with isocyanates and be inserted into the polyurethane segments to form a crosslinked macromolecular polyamine-polyurethane block copolymer, thereby improving the flexibility, impact resistance, and tensile strength of polyurethane, enhancing its fluidity, and making it easier to operate during the construction process. By controlling the type and dosage of polyamine, the hardness, flexibility, and elasticity of polyurethane coatings can be adjusted to meet different application requirements. Using multi-branched polyols and isocyanate monomers to copolymerize, the obtained polyurethane has an alternating soft segment and hard segment structure, which can increase the glass transition temperature of polyurethane. When the temperature exceeds this value, the fluidity of the soft segments in polyurethane increases, promoting the diffusion of water molecules, reducing the continuous high temperature, and improving safety.

[0004] Although the introduction of polyamine can improve the water resistance of polyurethane coatings to a certain extent, when they are in a humid environment for a long time, problems such as increased water absorption, coating blistering, and peeling may still occur; moreover, in a high-temperature environment, the coatings will also show aging phenomena such as powdering, discoloration, and loss of gloss, affecting their decorative and protective properties. Therefore, it is particularly important to provide a high-temperature resistant polyamine-based polyurethane coating and a preparation method thereof. Summary of the Invention

[0005] The present invention aims to provide a high-temperature resistant polyamine-based polyurethane coating and a preparation method thereof. The coating includes polyamine-based polyurethane, functional additives, and inorganic fillers. Using polyisocyanate monomers, branched polyols, and ethylene glycol to copolymerize to obtain a polyurethane with a three-dimensional network structure, and using sulfonate-based aqueous polyurethane diamine for chain extension to introduce polyamine groups and sulfonic acid groups, endowing the polyurethane with good flexibility and fluidity, and improving its freeze-thaw stability, storage stability, antistatic properties, etc.; adding fullerene to increase the glass transition temperature of polyurethane and improve its high-temperature resistance; filling with aluminum silicate to improve the impact resistance and wear resistance of the coating. The coating has excellent high-temperature resistance, waterproofness, and wear resistance, and is suitable for surface coating of products such as construction, automobiles, ships, wood, and leather.

[0006] To achieve the above object, the present invention provides a high-temperature resistant polyamino polyurethane coating, which comprises a polyamino polyurethane / fullerene composite, an inorganic filler, a leveling agent, an antifoaming agent, a dispersant, a light stabilizer and an antioxidant. The polyamino polyurethane / fullerene composite is obtained by polymerizing polyamino polyurethane and fullerene. The structure of the polyamino polyurethane is as follows:

[0007]

[0008] Wherein, n is an integer between 1 and 10.

[0009] Preferably, the mass ratio of the polyamino polyurethane / fullerene composite, the inorganic filler, the leveling agent, the antifoaming agent, the dispersant, the light stabilizer and the antioxidant is 1:(0.2 - 0.6):(0.05 - 0.1):(0.02 - 0.06):(0.01 - 0.5):(0.02 - 0.5):(0.03 - 0.08).

[0010] The present invention also provides a preparation method of the high-temperature resistant polyamino polyurethane coating, comprising:

[0011] Step S1: Polymeric methylene polyphenyl polyisocyanate, neopentyl glycol polyoxypropylene and ethylene glycol are mixed and polymerized under the protection of an inert gas to obtain a prepolymer;

[0012] Step S2: The prepolymer is mixed with a sulfonate-based aqueous polyurethane diamine and copolymerized to obtain polyamino polyurethane;

[0013] Step S3: Polyamino polyurethane and fullerene are added to a solvent for dissolution and polymerized to obtain a polyamino polyurethane / fullerene composite;

[0014] Step S4: The polyamino polyurethane / fullerene composite is mixed with the inorganic filler and stirred for the first time to obtain a mixture; a leveling agent, an antifoaming agent, a dispersant, a light stabilizer and an antioxidant are added to the mixture and stirred for the second time to obtain the high-temperature resistant coating.

[0015] Preferably, in step S1, the mass ratio of the polymeric methylene polyphenyl polyisocyanate, the neopentyl glycol polyoxypropylene and the ethylene glycol is 1:(1.5 - 2.5):(0.8 - 1.2).

[0016] Preferably, in step S1, the polymerization temperature is 80 - 100 °C and the polymerization time is 1 - 2 h.

[0017] Preferably, in step S2, the mass ratio of the prepolymer to the sulfonate-based aqueous polyurethane diamine is 1:(1 - 2).

[0018] Preferably, in the step S2, the copolymerization temperature is 90-120 °C, and the copolymerization time is 1-2 h.

[0019] Preferably, in the step S3, the solvent is any one or more of water, benzene, toluene, xylene, cyclohexanone, and dimethylformamide.

[0020] Preferably, in the step S3, the mass ratio of the polyamino polyurethane, fullerene, and solvent is 1:(0.0006-0.002):(2-3).

[0021] Preferably, in the step S3, the polymerization temperature is 100-120 °C, and the polymerization time is 8-10 h.

[0022] Preferably, in the step S4, the leveling agent is a cationic leveling agent, and the cationic leveling agent is any one or more of sodium polyoxyethylene benzenesulfonate, diphenyl polysiloxane, and dimethyl polysiloxane.

[0023] Preferably, in the step S4, the defoaming agent is any one or more of alkylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, and fatty acid ester polyoxyethylene ether; the light stabilizer is any one or more of hindered amine light stabilizer, 2,2'-methylphenyl-4-hydroxyphenylpropane, and 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)benzotriazole.

[0024] Preferably, in the step S4, the dispersant is any one or more of lignin sulfonate, alkyl aryl sulfonate, sodium oleate, and naphthalene sulfonate.

[0025] Preferably, in the step S4, the antioxidant is any one or more of hindered phenol antioxidants and dinonylcresol.

[0026] Preferably, in the step S4, the inorganic filler is any one or more of aluminum silicate, talc powder, and diatomaceous earth.

[0027] Preferably, in the step S4, the mass ratio of the polyamino polyurethane / fullerene composite to the inorganic filler is 1:(0.2-0.6).

[0028] Preferably, in the step S4, the first stirring temperature is 25-45 °C, and the stirring time is 5-6 h.

[0029] Preferably, in the step S4, the second stirring temperature is 50-60 °C, and the stirring time is 10-12 h.

[0030] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0031] (1) The polyurethane coating prepared by the present invention has good flexibility, fluidity and water dispersibility. In the present invention, a sulfonate-based aqueous polyurethane diamine containing a polyamine segment is copolymerized with polyurethane, and at the same time, a polyamine segment and a sulfonic acid group are introduced. The two amino groups in the sulfonate-based aqueous polyurethane diamine segment play a chain extension role and are embedded in the polyurethane segment to form a macromolecule with a cross-linked structure, improving the flexibility and fluidity of the polyurethane. The sulfonic acid group is a strongly polar functional group with strong polarity, which can enhance the stability of the polyurethane in aqueous solution, prevent the aggregation of polyurethane particles, and thus improve the water dispersibility. The sulfonic acid group has a high electronegativity, which can resist the invasion of hydrophilic molecules and at the same time improve its freeze-thaw stability, storage stability, antistatic property and other properties.

[0032] (2) The polyurethane coating prepared by the present invention has good high-temperature resistance. Polyisocyanate polymethylene polyphenyl polyisocyanate is copolymerized with neopentyl glycol polyoxypropylene, and ethylene glycol is used as a chain extender to prepare a polyurethane copolymerized with fullerene. The copolymerization of isocyanate and neopentyl glycol polyoxypropylene can obtain a three-dimensional structure with alternating soft segments and hard segments. Ethylene glycol as a chain extender can improve the cross-linking rate and increase the cross-linking density, improving the hardness, transparency and self-healing properties of the cured polyurethane. Adding fullerene can increase the glass transition temperature of the polyurethane and endow the coating with good heat resistance. In a high-temperature environment, the fluidity of the soft segment of the aqueous polyurethane with a three-dimensional structure increases, promoting the diffusion of water molecules, which can effectively reduce the temperature and prolong the time for the temperature to reach the glass transition temperature. When at a continuous high temperature and the temperature reaches the glass transition temperature, due to the presence of fullerene, it will reduce the fluidity of the soft segment of the polyurethane and increase the glass transition temperature of the polyurethane, enhancing the rigidity. Description of the Drawings

[0033] Figure 1 It is an electron microscope picture of the high-temperature resistant polyamine-based polyurethane coating prepared in Example 3.

[0034] Figure 2 It is a schematic diagram of the synthesis route of polyamine-based polyurethane.

[0035] Figure 3 It is a flow chart for the preparation of a high-temperature resistant polyamine-based polyurethane coating.

[0036] Figure 4 It is a comparison chart of the wear loss of the high-temperature resistant polyurethane coatings prepared in Examples 1-3 and Comparative Examples 1-4.

[0037] Figure 5 It is a comparison chart of the impact resistance of the high-temperature resistant polyurethane coatings prepared in Examples 1-3 and Comparative Examples 1-4.

[0038] Figure 6Graph showing the water absorption rates of the high-temperature resistant polyurethane coatings prepared in Examples 1-3 and Comparative Examples 1-4. Detailed implementation

[0039] The following examples are only used to more clearly illustrate the technical solutions of the present invention and cannot be used to limit the protection scope of the present invention.

[0040] The main compounds used in the examples and comparative examples are commercially available products without any further purification treatment.

[0041] Example 1

[0042] As Figure 2 and Figure 3 shown, a preparation method of a high-temperature resistant polyamine-based polyurethane coating includes the following steps:

[0043] Step S1: Accurately weigh 10 g of polymethylene polyphenyl polyisocyanate, 15 g of neopentyl glycol polyoxypropylene and 10 g of ethylene glycol, mix them, and polymerize at 80 °C for 2 h under nitrogen protection to obtain a prepolymer;

[0044] Step S2: Copolymerize 10 g of the prepolymer with 10 g of sulfonate-based waterborne polyurethane diamine at 90 °C for 2 h to obtain polyamine-based polyurethane;

[0045] Step S3: Mix 10 g of polyamine-based polyurethane and 0.006 g of fullerene, disperse them in 30 g of deionized water, and polymerize at 100 °C for 10 h to obtain a waterborne polyurethane / fullerene composite;

[0046] Step S4: Mix 10 g of the polyamine-based polyurethane / fullerene composite with 2 g of aluminum silicate, stir at 25 °C for 6 h to obtain a mixture, add 0.5 g of polyoxyethylene benzene sulfonate, 0.2 g of alkylphenol polyoxyethylene ether, 0.1 g of lignosulfonate, 0.2 g of hindered amine light stabilizer and 0.3 g of dinonyl cresol, and stir at 50 °C for 12 h to obtain a high-temperature resistant coating.

[0047] Example 2

[0048] As Figure 2 and Figure 3 shown, a preparation method of a high-temperature resistant polyamine-based polyurethane coating includes the following steps:

[0049] Step S1: Accurately weigh 10 g of polymethylene polyphenyl polyisocyanate, 20 g of neopentyl glycol polyoxypropylene and 8 g of ethylene glycol, mix them, and polymerize at 90 °C for 2 h under nitrogen atmosphere to obtain a prepolymer;

[0050] Step S2: Copolymerize 10 g of the prepolymer with 15 g of sulfonate-based waterborne polyurethane diamine at 100 °C for 1 h to obtain polyamine-based polyurethane;

[0051] Step S3: Mix 10 g of polyamino polyurethane and 0.01 g of fullerene, disperse them in 30 g of deionized water, and polymerize at 110 °C for 9 h to obtain a waterborne polyurethane / fullerene composite;

[0052] Step S4: Mix 10 g of the polyamino polyurethane / fullerene composite with 4 g of aluminum silicate, stir at 35 °C for 6 h to obtain a mixture, add 0.75 g of sodium polyoxyethylene benzene sulfonate, 0.4 g of alkylphenol polyoxyethylene ether, 0.3 g of lignosulfonate, 0.35 g of hindered amine light stabilizer and 0.55 g of dinonyl cresol, and stir at 55 °C for 11 h to obtain a high-temperature resistant coating.

[0053] Example 3

[0054] As Figure 2 and Figure 3 shown, a preparation method of a high-temperature resistant polyamino polyurethane coating includes the following steps:

[0055] Step S1: Accurately weigh 10 g of polymethylene polyphenyl polyisocyanate, 25 g of neopentyl glycol polyoxypropylene and 12 g of ethylene glycol, mix them, and polymerize at 100 °C for 1 h under a nitrogen atmosphere to obtain a prepolymer;

[0056] Step S2: Copolymerize 10 g of the prepolymer with 20 g of sulfonate-type waterborne polyurethane diamine at 120 °C for 1 h to obtain polyamino polyurethane;

[0057] Step S3: Mix 10 g of polyamino polyurethane and 0.02 g of fullerene, disperse them in 30 g of deionized water, and polymerize at 120 °C for 8 h to obtain a polyamino polyurethane / fullerene composite;

[0058] Step S4: Mix 10 g of the polyamino polyurethane / fullerene composite with 6 g of aluminum silicate, stir at 45 °C for 5 h to obtain a mixture, add 1 g of sodium polyoxyethylene benzene sulfonate, 0.6 g of alkylphenol polyoxyethylene ether, 0.5 g of lignosulfonate, 0.5 g of hindered amine light stabilizer and 0.8 g of dinonyl cresol, and stir at 60 °C for 10 h to obtain a high-temperature resistant coating, and the electron microscope picture is as Figure 1 shown.

[0059] Comparative Example 1

[0060] A preparation method of a high-temperature resistant polyamino polyurethane coating, which is different from Example 2 in that ethylene glycol is not added in step (1).

[0061] Comparative Example 2

[0062] A preparation method of a high-temperature resistant polyamino polyurethane coating, which is different from Example 3 in that sulfonate-type waterborne polyurethane diamine is not added in step (2).

[0063] Comparative Example 3

[0064] A preparation method of a high-temperature resistant polyamine-based polyurethane coating, which is different from Example 3 in that fullerene is not added in step (3).

[0065] Comparative Example 4

[0066] A preparation method of a high-temperature resistant polyamine-based polyurethane coating, which is different from Example 3 in that aluminum silicate is not added in step (4).

[0067] Performance test:

[0068] (1) Abrasion resistance: The coatings prepared in Examples 1 to 3 and Comparative Examples 1 to 4 were evenly applied on a glass plate, and the abrasion resistance was tested after drying at a constant temperature of 80°C for 6 h (GB / T 1768-2006).

[0069] (2) Mechanical properties: The coatings prepared in Examples 1 to 3 and Comparative Examples 1 to 4 were evenly applied on release paper, and after drying at a constant temperature of 60°C for 2 h, their impact resistance was tested (GB / T 1732-1993).

[0070] (3) Waterproof performance: The coatings prepared in Examples 1 to 3 and Comparative Examples 1 to 4 were coated on a glass substrate (coating amount: 0.5 mg / cm 2 ), dried at a constant temperature of 60°C for 1 to 3 h, and waited for curing to obtain samples. Then the samples were immersed in distilled water at 60°C for 48 h, and the water absorption rate of the samples was tested.

[0071] Water absorption rate (%) = (mass of the sample after soaking for 48 h - initial mass of the sample) / initial mass of the sample × 100%. The lower the water absorption rate, the better the waterproof performance.

[0072] (4) High-temperature resistance performance: The coatings prepared in Examples 1 to 3 and Comparative Examples 1 to 4 were evenly applied on release paper, and after drying at a constant temperature of 70°C for 8 h, their 5% thermal weight loss temperature, glass transition temperature, high-temperature resistance test (GB / T 19250-2021), and thermal conductivity (ISO 24449:2021) were tested.

[0073] According to Figure 4As shown, the abrasion loss of the coatings prepared in Examples 1 to 3 and Comparative Examples 2 to 3 is significantly lower than that in Comparative Example 1 and Comparative Example 4, showing good abrasion resistance. In step (1) of preparing the coating in Comparative Example 1, ethylene glycol was not added, and in step (4) of preparing the coating in Comparative Example 4, aluminum silicate was not added, resulting in a significant reduction in the anti-friction strength of the obtained coatings. Experiments have proved that ethylene glycol, as a chain extender, can promote the cross-linking of polymethylene polyphenyl polyisocyanate and neopentyl glycol polyoxypropylene to form a stable three-dimensional polyurethane structure. Aluminum silicate has good damping performance and can absorb the vibration energy of the coating when subjected to external forces, reducing the wear of the coating caused by vibration. At the same time, it can reduce the porosity of the coating, contributing to improving the rigidity, hardness and abrasion resistance of the coating.

[0074] According to Figure 5 As shown, the coatings prepared in Examples 1 to 3 and Comparative Examples 2 to 3 show good impact resistance. In Comparative Example 4, aluminum silicate was not added, resulting in a significant reduction in the impact resistance of the prepared coating. In Comparative Example 1, ethylene glycol was added, and the prepared coating had a low cross-linking density and poor impact resistance. Experiments have proved that adding ethylene glycol helps the polyurethane to form a stable three-dimensional structure and improve the mechanical properties of the coating, and filling aluminum silicate helps to disperse stress and improve the impact resistance.

[0075] According to Figure 6 As shown, the water absorption rates of the coatings prepared in Comparative Examples 1 to 3 are all below 0.5%, showing good waterproof performance. The coatings prepared in Comparative Examples 1 to 2 and Comparative Example 4 have varying degrees of water absorption, among which the water absorption rate of Comparative Example 2 is the highest. Since sulfonate-type waterborne polyurethane diamine was not added in step (2) of preparing the coating in Comparative Example 2, no sulfonic acid group was introduced into its polyurethane structure. The sulfonic acid group has a high electronegativity and can resist the invasion of hydrophilic molecules. In step (4) of preparing the coating in Comparative Example 4, aluminum silicate was not added. Aluminum silicate itself is a hydrophobic filler, and its tiny particles can form tiny pores and channels in the coating. These pores and channels are filled on the surface of the coating after drying, reducing water penetration.

[0076] Table 1 Test data of the thermal conductivity of the coatings (unit: W / (m·K))

[0077]

[0078] According to Table 1, the thermal conductivities of the coatings prepared in Examples 1 to 3 were tested at 25 to 400 °C. Compared with Comparative Examples 1 to 4, the thermal conductivities of the coatings prepared in Examples 1 to 3 are lower, indicating poor thermal conductivity of the coatings. Therefore, they have good heat preservation and heat insulation effects, are light in weight, convenient for construction and transportation, and at the same time have high strength and durability.

[0079] Table 2 High-temperature resistance parameters of the coatings

[0080] Sample number <![CDATA[Td 5％ (℃)]]> Glass transition temperature (°C) High temperature resistance test Example 1 568 398 No cracking after 5 h at 450 °C Example 2 576 406 No cracking after 5 h at 450 °C Example 3 572 401 No cracking after 5 h at 450 °C Comparative example 1 435 346 No cracking after 5 h at 450 °C Comparative example 2 389 318 Cracking after 5 h at 450 °C Comparative example 3 391 326 Cracking after 5 h at 450 °C Comparative example 4 520 381 No cracking after 5 h at 450 °C

[0081] As shown in Table 2, the 5% thermal weight loss temperature of the coatings prepared in Examples 1 to 3 is above 550 °C, and the glass transition temperature is also higher than that of the coatings prepared in Comparative Examples 1 to 4. After 5 hours at 450 °C, no cracking occurred in the coatings, indicating good heat resistance. The coating prepared in Comparative Example 1 has poor thermal stability due to the low polymer crosslinking density and is easily decomposed at high temperatures; in the coating prepared in Comparative Example 2, due to the lack of polyamine segments, the flexibility and fluidity are poor, the glass transition temperature is low, the shrinkage is large at high temperatures, and it is prone to cracking; in Comparative Example 3, fullerenes are lacking. Once the temperature exceeds the glass transition temperature, the coating cures, and continued temperature increase will lead to overheating deformation and cracking.

[0082] In summary, preparing three-dimensional macromolecular polyurethane by copolymerizing polymethylene polyphenyl polyisocyanate and neopentyl glycol polyoxypropylene can obtain a polymer with alternating hard and soft segments, improving the flexibility and fluidity of polyurethane; using ethylene glycol as a chain extender can promote the polymerization reaction, increase the crosslinking density of polyurethane, promote the formation of a stable three-dimensional structure, and improve the mechanical properties of polyurethane. Adding sulfonate-based waterborne polyurethane diamine to introduce polyamine groups and sulfonic acid groups into the polyurethane structure can improve the flexibility and fluidity of polyurethane; the addition of fullerenes effectively improves the high-temperature resistance of the coating. In a high-temperature environment, the fluidity of the three-dimensional polyurethane soft segment increases, promoting the diffusion of water molecules, which can effectively reduce the temperature and extend the time for the temperature to reach the glass transition temperature. When at a continuous high temperature and the temperature reaches the glass transition temperature, due to the presence of fullerenes, it will reduce the fluidity of the polyurethane soft segments, increase the glass transition temperature of polyurethane, and enhance rigidity.

[0083] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and deformations can be made, and these improvements and deformations should also be regarded as the protection scope of the present invention.

Claims

1. A high-temperature resistant polyamine-based polyurethane coating, characterized in that, It includes a polyamino polyurethane / fullerene composite, an inorganic filler, a leveling agent, an antifoaming agent, a dispersant, a light stabilizer, and an antioxidant. The polyamino polyurethane / fullerene composite is obtained by polymerizing polyamino polyurethane and fullerene. The structure of the polyamino polyurethane is as follows: In the said structure, n is an integer between 1 and 10.

2. The high-temperature resistant polyamino polyurethane coating according to claim 1, wherein The mass ratio of the polyamino polyurethane / fullerene composite, inorganic filler, leveling agent, antifoaming agent, dispersant, light stabilizer, and antioxidant is 1:(0.2 - 0.6):(0.05 - 0.1):(0.02 - 0.06):(0.01 - 0.5):(0.02 - 0.5):(0.03 - 0.08).

3. The preparation method of a high-temperature resistant polyamine-based polyurethane coating according to claim 1 or 2, characterized in that, It includes: Step S1: Mix polymethylene polyphenyl polyisocyanate, neopentyl glycol polyoxypropylene, and ethylene glycol, and polymerize under the protection of an inert gas to obtain a prepolymer; Step S2: Mix the prepolymer with a sulfonate-type aqueous polyurethane diamine and copolymerize to obtain polyamino polyurethane; Step S3: Dissolve polyamino polyurethane and fullerene in a solvent and polymerize to obtain a polyamino polyurethane / fullerene composite; Step S4: Mix the polyamino polyurethane / fullerene composite with an inorganic filler and stir for the first time to obtain a mixture; add a leveling agent, an antifoaming agent, a dispersant, a light stabilizer, and an antioxidant to the mixture and stir for the second time to obtain a high-temperature resistant coating.

4. The preparation method of a high-temperature resistant polyamine-based polyurethane coating according to claim 3, characterized in that, In step S1, the mass ratio of the polymethylene polyphenyl polyisocyanate, neopentyl glycol polyoxypropylene, and ethylene glycol is 1:(1.5 - 2.5):(0.8 - 1.2); the polymerization temperature is 80 - 100°C, and the polymerization time is 1 - 2 h.

5. The preparation method of a high-temperature resistant polyamine-based polyurethane coating according to claim 3, characterized in that, In step S2, the mass ratio of the prepolymer to the sulfonate-type aqueous polyurethane diamine is 1:(1 - 2); the copolymerization temperature is 90 - 120°C, and the copolymerization time is 1 - 2 h.

6. The preparation method of a high-temperature resistant polyamine-based polyurethane coating according to claim 3, characterized in that, In step S3, the solvent is any one or more of water, benzene, toluene, xylene, cyclohexanone, and dimethylformamide; the mass ratio of the polyamino polyurethane, fullerene, and solvent is 1:(0.0006 - 0.002):(2 - 3); the polymerization temperature is 100 - 120°C, and the polymerization time is 8 - 10 h.

7. The preparation method of a high-temperature resistant polyamino polyurethane coating according to claim 3, characterized in that, In step S4, the leveling agent is a cationic leveling agent, and the cationic leveling agent is any one or more of sodium polyoxyethylene benzenesulfonate, diphenyl polysiloxane, and dimethyl polysiloxane; the antifoaming agent is any one or more of alkylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, and fatty acid ester polyoxyethylene ether; the light stabilizer is any one or more of a hindered amine light stabilizer, 2,2'-methylphenyl-4-hydroxyphenyl propane, and 2-(2'-hydroxy-3',5'-di-tert-butylphenyl) benzotriazole.

8. The preparation method of a high-temperature resistant polyamine-based polyurethane coating according to claim 3, characterized in that, In step S4, the dispersant is any one or more of lignin sulfonate, alkyl aryl sulfonate, sodium oleate, and naphthalene sulfonate.

9. The preparation method of a high-temperature resistant polyamine-based polyurethane coating according to claim 3, wherein In step S4, the antioxidant is any one or more of a hindered phenol antioxidant and dinonyl cresol; the inorganic filler is any one or more of aluminum silicate, talcum powder, and diatomaceous earth.

10. The preparation method of a high-temperature resistant polyamine-based polyurethane coating according to claim 3, characterized in that, In the step S4, the temperature of the first stirring is 25 to 45 °C, and the stirring time is 5 to 6 h; the temperature of the second stirring is 50 to 60 °C, and the stirring time is 10 to 12 h.

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