Aspartic ester-terminated hyperbranched polysiloxane and heavy anti-corrosion coating thereof as well as preparation method and application of aspartic ester-terminated hyperbranched polysiloxane and heavy anti-corrosion coating

Abstract

The invention belongs to the field of coatings, and particularly relates to an aspartic ester-terminated hyperbranched polysiloxane and a heavy anti-corrosion coating thereof, and a preparation method and application of the aspartic ester-terminated hyperbranched polysiloxane and the heavy anti-corrosion coating, the aspartic ester-terminated hyperbranched polysiloxane is hyperbranched resin which is composed of a polysiloxane Si-O-Si framework and has a three-dimensional space, and the aspartic ester-terminated hyperbranched polysiloxane contains secondary amino groups capable of being subjected to curing reaction with isocyanate. The preparation method comprises the following two steps: 1, carrying out Michael addition reaction on gamma-amino propyl triethoxy silane and diethyl maleate to obtain N-propyl triethoxy silane terminated by aspartate ester; and 2, carrying out hydrolytic condensation to obtain the aspartic ester terminated hyperbranched polysiloxane. Therefore, the aspartic acid ester coating of a high-solid-content solvent type and solvent-free system can be prepared, and the aspartic acid ester coating is used as a'primer-topcoat 'heavy anti-corrosion coating.

Description

Technical Field

[0001] The invention belongs to the field of coatings, and particularly relates to an aspartic acid ester-terminated hyperbranched polysiloxane and a heavy-duty anticorrosive coating thereof, and a preparation method and application thereof. Background Art

[0002] In the past decade, two-component polyaspartic acid ester polyurea coatings have received more and more attention and applications in various fields of the national economy. This is mainly due to the special molecular structure of aspartic acid ester and the moderate reactivity of secondary amino groups, which make aspartic acid polyurea coatings have high solid content, fast curing at room temperature, aging resistance, moderate corrosion resistance, impact resistance, wear resistance and other excellent characteristics. Therefore, it is a new type of high-performance environmentally friendly coatings. So far, the product forms of two-component polyaspartic acid ester polyurea coatings have covered high solid content (construction solid content greater than 75%) system, solvent-free (construction solid content greater than 98%) system and water-based system, and are used in building waterproofing, floor paving, furniture and wood, steel structure protection, automobile and shipbuilding, engineering machinery, mining machinery and automobile maintenance and other fields.

[0003] However, common aspartic acid ester polyurea coatings still have many obvious deficiencies, which is mainly due to the small molecular weight of aspartic acid ester and the relatively high ester bond content, so the hydrophobicity and anti-permeability of the coating are not good. At the same time, the traditional polyaspartic acid ester polyurea is basically based on a straight chain structure, so the shrinkage rate of the coating after curing is relatively large, which can reach up to 1-1.5%, which significantly affects the adhesion of the aspartic acid polyurea coating, especially to the rigid metal substrate. In view of the above reasons, common aspartic acid polyurea coatings generally cannot be directly used in industrial areas with very high corrosion environments (C5 and above), but can only be used in occasions with medium or lower corrosion environments (below C3), and they also need to be used in combination with primers, so the scope of application is limited.

[0004] As we all know, as a new type of energy-saving and environmentally friendly coating, asparagine polyurea coating can not only be used as a thick paste coating (one-time coating thickness is greater than 150μm), but also its coating film has aging resistance, physical and mechanical properties, friction resistance and construction performance that are incomparable to traditional thick paste coatings. Therefore, by modifying the traditional aspartic acid ester resin or improving the formula of the traditional asparagine polyurea coating, the shortcomings of asparagine polyurea itself can be overcome, so that asparagine polyurea coating can be used in the field of heavy industrial corrosion protection in the form of "bottom-to-bottom integration". This can not only expand the application scope of asparagine polyurea coating, but also promote the concept of energy saving, environmental protection and high efficiency in the coating industry, and implement the national strategy of "green and sustainable development". In fact, the focus of asparagine polyurea coating research and development in recent years has always been on "bottom-to-bottom integration" and heavy anti-corrosion applications, and the number of patent reports during this period has also increased.

[0005] Chinese patent CN112210279 reports a bottom-to-top integrated asparagine polyurea coating. It is characterized by using a slightly branched polyester polyol compounded with a polyaspartic acid ester resin, supplemented with an active diluent and a high-boiling point solvent to adjust the viscosity and operable time of the coating system. The patent mainly focuses on process performance and coating appearance, such as moderate viscosity, high-pressure airless spraying, a one-time film thickness of 150-350μm, and a smooth surface. However, compared with secondary amino groups, the reactivity of hydroxyl groups with isocyanate curing agents is much lower. Therefore, adding hydroxyl-containing (polyester polyol) substances to the asparagine resin system of secondary amino groups will produce inconsistencies in curing, composition, and performance, resulting in a decrease in the overall performance of the coating.

[0006] US Patent US20060058492 reports a mercaptan-modified polyurethane-polyurea coating. It is characterized in that a thiol-terminated aliphatic polysulfide compound (ALIPS) or other thiol-terminated polymers are used as the main resin, and a small molecule amine is used as a chain extender, and a sulfur-containing polyurethane-polyurea coating is obtained after curing with isocyanate. It is said that using it as a heavy-duty anticorrosive coating can significantly improve the corrosion resistance and anti-penetration performance of the coating after long-term contact with organic solvents. However, this mercaptan-terminated polymer is expensive, and both the raw material and the coating itself have a significant sulfur odor.

[0007] US Patent No. 7247351 discloses a polyurea coating modified with organosilicon. It is characterized in that a polysiloxane terminated with a tertiary epoxy group is reacted with a polyamine to obtain a polysiloxane terminated with an amino group. The patent claims that by introducing silicon into the molecular structure of the polyurea coating as a chain extender, the adhesion, corrosion resistance and aging resistance of the polyurea coating can be improved. At the same time, the silicon-containing chain extender with a branched structure further reduces the shrinkage rate of the coating film. However, the source of the tertiary epoxy group-terminated polysiloxane used in the patent is extremely scarce and cannot be used in practice.

[0008] Chinese patent CN113637398 reports a bottom-to-surface integrated asparagine polyurea heavy anticorrosive coating. It is characterized in that the silicon triol obtained by hydrolysis of trichlorosilane is reacted with diisocyanate to obtain silicon-containing triisocyanate, then reacted with diprimary amine to obtain silicon-containing ternary primary amine, and finally reacted with diethyl maleate by Michael addition reaction to obtain silicon-containing ternary aspartic acid ester, which is called hyperbranched modified aspartic acid resin in the patent. The patent claims that, on the one hand, due to the presence of hyperbranched structure, this asparagine polyurea coating adds more mild reaction active points, making the curing reaction more uniform and generating less stress, thereby reducing the shrinkage rate of the coating after curing and improving the adhesion to the metal substrate; on the other hand, due to the presence of silicon element, the temperature resistance, wear resistance, corrosion resistance and aging resistance of the coating are greatly improved. In terms of the idea of ​​solving the pain point problem of traditional polyurea, it is undeniable that the starting point of the patent is desirable, that is, on the one hand, the branching degree of the resin is increased, and on the other hand, it is modified with silicon element. However, the synthesis route of the so-called hyperbranched aspartic acid resin selected in the patent is too long and complicated, and the HCl produced by the hydrolysis of chloroform also brings pollution and corrosion problems. Therefore, it is difficult to apply in practice.

[0009] As is known to all, hyperbranched polymer is a polymer with a highly branched structure, and its degree of branching is greater than that of general branched polymers, but less than that of dendritic polymers. Compared with linear polymers, hyperbranched polymers contain no or very little linear structure, and no intrachain entanglement, so they have very low viscosity, good fluidity, solubility and film-forming properties. The high degree of branching of hyperbranched polymers breaks the regularity and symmetry of traditional linear polymers, and the cured coating has an "isotropic" effect, thereby reducing the shrinkage rate of the coating after curing. In addition, the terminal functional groups of hyperbranched polymers are highly reactive and can be used for further reaction to prepare various high-performance polymer materials. The unique molecular structure, superior thermal and mechanical properties, and potential application prospects have made hyperbranched polymers begin to be used in the fields of viscosity modifiers, solvent-free coatings, curing agents and adhesives for thermosetting materials.

[0010] To this end, the present invention combines the excellent mechanical properties, corrosion resistance, temperature resistance and good biocompatibility of polysiloxane with the special structural morphology of hyperbranched polymers, and invents an aspartic acid ester-terminated hyperbranched polysiloxane resin, and thereby prepares a hyperbranched polysiloxane-modified aspartic acid polyurea heavy-duty anticorrosion coating, including high-solid solvent-based coatings and solvent-free coatings. The test results show that the two-component aspartic acid polyurea coating based on aspartic acid ester-terminated hyperbranched polysiloxane involved in the present invention not only significantly improves the adhesion of aspartic acid polyurea coating as a thick paste type "bottom-to-bottom" coating to the metal substrate, but also amazingly improves the coating scratch resistance to salt spray, so that it can meet the requirements of the bottom-to-bottom aspartic acid polyurea coating in heavy-duty anticorrosion fields such as oil pipeline valves, chemical storage tank inner walls, offshore wind power towers, container coatings, and mine support protection. Summary of the invention

[0011] Purpose of the Invention

[0012] In view of the reality that ordinary aspartic acid polyurea coatings cannot be used in the field of industrial heavy-duty corrosion protection, the purpose of the present invention is to provide a two-component aspartic acid polyurea coating based on aspartic acid ester-terminated hyperbranched polysiloxane, including high-solid solvent-based coatings and solvent-free coatings, so that it can meet the requirements of industrial heavy-duty corrosion protection for anti-corrosion coatings, and can save the primer coating in the traditional coating process to achieve bottom-and-top integrated coating, which saves materials and improves efficiency.

[0013] Technical Solution

[0014] The present invention firstly relates to an aspartic acid ester-terminated hyperbranched polysiloxane; the present invention further relates to a method for preparing the aspartic acid ester-terminated hyperbranched polysiloxane; the present invention further relates to a two-component aspartic acid polyurea coating based on the aspartic acid ester-terminated hyperbranched polysiloxane, including a high-solid solvent-based coating and a solvent-free coating; the present invention further relates to a method for preparing the two-component aspartic acid polyurea coating based on the aspartic acid ester-terminated hyperbranched polysiloxane, including a high-solid solvent-based coating and a solvent-free coating; the present invention finally relates to an application of the two-component aspartic acid polyurea coating based on the aspartic acid ester-terminated hyperbranched polysiloxane, including a high-solid solvent-based coating and a solvent-free coating.

[0015] The present invention firstly relates to an aspartic acid ester-terminated hyperbranched polysiloxane (hereinafter referred to as HBPSi-AP), which is characterized in that it is a highly branched and three-dimensional hyperbranched resin composed of a polysiloxane Si-O-Si skeleton, and contains a secondary amino group that can further react with isocyanate for curing, and its structural formula is as follows (Formula 1):

[0016]

[0017] in:

[0018]

[0019] The present invention also relates to a method for preparing HBPSi-AP, which is characterized by having the following two steps: 1. Michael addition reaction of γ-aminopropyltriethoxysilane (coupling agent KH550) and diethyl maleate to obtain n-propyltriethoxysilane terminated with aspartic acid ester. The reaction formula is as follows (Formula 2):

[0020]

[0021] 2 The above-mentioned aspartic acid ester-terminated n-propyl triethoxysilane is subjected to hydrolysis and condensation reaction to obtain HBPSi-AP resin. The reaction process is as follows (Formula 3):

[0022]

[0023] in:

[0024]

[0025] The formula and process for the Michael addition reaction of the above-mentioned γ-aminopropyltriethoxysilane (coupling agent KH550) and diethyl maleate can be performed according to the existing synthesis technology of aspartic acid ester, that is, the appropriate molar ratio of KH550 to diethyl maleate is 1:1.0-1:1.005, preferably 1:1.0-1:1.002. Diethyl maleate is first added dropwise to KH550 under nitrogen protection and low temperature (45-50°C), and the dropwise reaction temperature is controlled not to exceed 65°C, preferably not to exceed 60°C. After the dropwise addition is completed, the reaction is maintained at a constant temperature of 60±2°C for 8-20 hours, preferably 10-15 hours. After the reaction is completed, it is cooled to below 40°C to obtain n-propyltriethoxysilane terminated by aspartic acid ester.

[0026] The HBPSi-AP resin is prepared by hydrolysis and condensation of the aspartic acid ester-terminated n-propyl triethoxysilane, in the presence of deionized water and ethanol solvent, triethoxysilane Si(OEt) 3 First hydrolyze to generate silicon triol Si(OH) 3Then, it is polycondensed under the action of the solvent to form HBPSi-AP. The specific method is: first, aspartic acid ester-terminated n-propyl triethoxysilane is dissolved in an ethanol solvent at a weight ratio of 1:1, then nitrogen is introduced to exclude oxygen, and deionized water is added under stirring. The amount of deionized water added is calculated according to the molar ratio of 1:1-1.3:1 to aspartic acid ester-terminated n-propyl triethoxysilane, preferably 1:1-1.2:1. Then, reflux reaction is carried out at 55-60°C for 4 hours. After the reaction is completed, ethanol, water and other small molecules are removed by vacuum to obtain a colorless, low-viscosity oily product, which is HBPSi-AP.

[0027] The present invention also relates to a two-component aspartame polyurea coating based on HBPSi-AP, including a high-solid solvent-based coating and a solvent-free coating.

[0028] The high-solid solvent-based two-component aspartame polyurea coating based on HBPSi-AP is characterized by:

[0029] Its A component, i.e. the resin component, is composed of:

[0030] 1 at least 25% by weight of HBPSi-AP;

[0031] 2 up to 10% by weight of aspartic acid ester resin;

[0032] 3. Up to 55% by weight of pigments, fillers and coating additives;

[0033] 4 Up to 10% by weight of environmentally friendly solvents,

[0034] The above weight percentages are calculated based on the total weight of component A.

[0035] Its B component, the curing agent component, is composed of:

[0036] 1 at least 90% by weight of an isocyanate curing agent;

[0037] 2 up to 10% by weight of an environmentally friendly solvent. The above weight percentage is calculated based on the total weight of component B.

[0038] The weight mixing ratio of the above-mentioned components A and B is 2:1-2.5:1, and the construction solid content is 80-85%.

[0039] The present invention relates to a solvent-free two-component aspartame polyurea coating based on HBPSi-AP, which is characterized by:

[0040] Its A component, i.e. the resin component, is composed of:

[0041] 1 at least 25% by weight of HBPSi-AP;

[0042] 2 up to 15% by weight of aspartic acid ester resin;

[0043] 3. Up to 55% by weight of pigments, fillers and coating additives;

[0044] 4 Up to 5% by weight of reactive diluent.

[0045] The above weight percentages are calculated based on the total weight of component A.

[0046] Its B component, the curing agent component, is composed of:

[0047] It is composed of solvent-free isocyanate curing agent.

[0048] The weight mixing ratio of the above components A and B is 2.5:1-2.7:1, which is converted into a volume mixing ratio of 2:1. The construction solid content is 98-100%.

[0049] The present invention further relates to a method for preparing a two-component aspartame polyurea coating based on HBPSi-AP, including a high-solid solvent-based coating and a solvent-free coating.

[0050] In the above-mentioned component A, suitable aspartic acid ester resins include but are not limited to Covestrode's Desmophen NH1420, NH1520, NH1220 and NH2850, etc., which can be used alone or mixed with each other in any proportion.

[0051] In the above-mentioned component A, suitable pigments and fillers include functional fillers and modified pigments and fillers, wherein the functional fillers include but are not limited to zinc phosphate, zinc phosphomolybdate, zinc aluminum phosphate and mica powder, etc., which can be used alone or mixed with each other in any proportion. The total amount used is 15-30% of the total weight of component A, preferably 20-25%. Suitable modified pigments and fillers include but are not limited to titanium dioxide, calcium carbonate, barium sulfate and talcum powder, carbon black, iron red, etc., which can be used alone or mixed with each other in any proportion. The total amount used is 15-30% of the total weight of component A, preferably 20-25%.

[0052] In the above-mentioned component A, suitable coating additives include but are not limited to dispersants, leveling agents, defoamers, thixotropic agents, water removers, antioxidants and anti-ultraviolet agents, etc. Their quality and dosage can be selected according to the current conventional technical requirements for high-solid coating systems, but their total amount used is 3-10% of the total weight of component A, preferably 5-8%.

[0053] In the above-mentioned component A, suitable environmentally friendly solvents include, but are not limited to, propylene glycol methyl ether acetate (PMA), a mixture of dimethyl succinate, dimethyl glutarate and dimethyl adipate (DBE), ethyl 3-ethoxypropionate (EEP), butyl acetate (BAC), etc. They can be used alone or mixed in any proportion.

[0054] In the above-mentioned component B, suitable isocyanate curing agents are isocyanate curing agents commonly used in polyurethane coatings or polyurea coatings in the coating field, which can be aliphatic isocyanate curing agents or aromatic isocyanate curing agents. Including but not limited to hexamethylene diisocyanate (HDI) and its trimer, HDI biuret, isophorone diisocyanate (IPDI) and its trimer, dicyclohexylmethane diisocyanate (HMDI), diphenylmethane diisocyanate (MDI), liquefied MDI, toluene diisocyanate (TDI), TDI dimer, TDI trimer and TDI modified prepolymer, etc. They can be used alone or mixed with each other in any proportion.

[0055] In the above-mentioned component B, suitable environmentally friendly solvents include, but are not limited to, propylene glycol methyl ether acetate (PMA), a mixture of dimethyl succinate, dimethyl glutarate and dimethyl adipate (DBE), ethyl 3-ethoxypropionate (EEP), butyl acetate (BAC), etc. They can be used alone or mixed in any proportion.

[0056] The actual mixing ratio of the above-mentioned components A and B is calculated according to the amino equivalent and isocyanate equivalent in components A and B, respectively, and makes [NH] / [NCO]=1:1.05-1:1.1.

[0057] The preparation method of component A of the above-mentioned high-solid solvent-based coating can be carried out by referring to the preparation technology of the corresponding resin component in the current coating field, namely:

[0058] 1. Weigh HBPSi-AP and appropriate aspartic acid ester resin into a suitable container and stir to mix evenly;

[0059] 2. Add appropriate amount of solvent, dispersant and defoamer, and stir to mix evenly;

[0060] 3. While stirring, add pigment, filler and other coating additives except leveling agent, antioxidant and anti-ultraviolet agent in turn, and then disperse at high speed (2000rpm) for 30min;

[0061] 4. Grind the mixed slurry into a sand mill until the fineness is ≤35μm;

[0062] 5. Add leveling agent, antioxidant, anti-ultraviolet agent and remaining solvent to the above-ground slurry under stirring, adjust the color with appropriate color paste, and then disperse at high speed (2000rpm) for 30min;

[0063] 6. Packing to obtain the finished product.

[0064] The preparation method of the component B of the high-solid solvent-based coating can directly mix a suitable curing agent and an environmentally friendly solvent evenly, and then package to obtain a finished product.

[0065] The present invention relates to a solvent-free two-component aspartame polyurea coating based on HBPSi-AP, which is characterized by:

[0066] Its A component, i.e. the resin component, is composed of:

[0067] 1 at least 25% by weight of HBPSi-AP;

[0068] 2 up to 15% by weight of aspartic acid ester resin;

[0069] 3. Up to 55% by weight of pigments, fillers and coating additives;

[0070] 4 Up to 5% by weight of reactive diluent.

[0071] The above weight percentages are calculated based on the total weight of component A.

[0072] Its B component, the curing agent component, is composed of:

[0073] It is composed of solvent-free isocyanate curing agent.

[0074] The weight mixing ratio of the above-mentioned components A and B is 2.5:1-3:1, which is converted into a volume mixing ratio of 2:1. The construction solid content is 98-100%.

[0075] In the above-mentioned component A, suitable aspartic acid ester resins include but are not limited to Covestrode's Desmophen NH1420, NH1520, NH1220 and NH2850, etc., which can be used alone or mixed with each other in any proportion.

[0076] In the above-mentioned component A, suitable pigments and fillers include functional fillers and modified pigments and fillers, wherein the functional fillers include but are not limited to zinc phosphate, zinc phosphomolybdate, zinc aluminum phosphate and mica powder, etc., which can be used alone or mixed with each other in any proportion. The total amount used is 15-30% of the total weight of component A, preferably 20-25%. Suitable modified pigments and fillers include but are not limited to titanium dioxide, calcium carbonate, barium sulfate and talcum powder, carbon black, iron red, etc., which can be used alone or mixed with each other in any proportion. The total amount used is 15-30% of the total weight of component A, preferably 20-25%.

[0077] In the above-mentioned component A, suitable coating additives include but are not limited to dispersants, leveling agents, defoamers, thixotropic agents, water removers, antioxidants and anti-ultraviolet agents, etc. Their quality and dosage can be selected according to the current conventional technical requirements for solvent-free coating systems, but their total amount used is 3-10% of the total weight of component A, preferably 5-8%.

[0078] In the above-mentioned component A, suitable active diluents include but are not limited to propylene carbonate (PC), γ-butyrolactone, acetyl tributyl citrate (ATBC), etc. They can be used alone or mixed with each other in any proportion.

[0079] In the above-mentioned component B, suitable isocyanate curing agents are isocyanate curing agents commonly used in polyurethane coatings or polyurea coatings in the coating field, which can be aliphatic isocyanate curing agents or aromatic isocyanate curing agents. Including but not limited to hexamethylene diisocyanate (HDI) and its trimer, HDI biuret, isophorone diisocyanate (IPDI) and its trimer, dicyclohexylmethane diisocyanate (HMDI), diphenylmethane diisocyanate (MDI), liquefied MDI, toluene diisocyanate (TDI), TDI dimer, TDI trimer and TDI modified prepolymer, etc. They can be used alone or mixed with each other in any proportion.

[0080] The actual mixing ratio of the above-mentioned components A and B is calculated according to the amino equivalent and isocyanate equivalent in components A and B, respectively, and makes [NH] / [NCO]=1:1.05-1:1.1.

[0081] The preparation method of the above-mentioned component A of the solvent-free coating can be carried out by referring to the preparation technology of the corresponding resin component in the current coating field, namely:

[0082] 1. Weigh HBPSi-AP and appropriate aspartic acid ester resin into a suitable container and stir to mix evenly;

[0083] 2. Add appropriate amount of active diluent, dispersant and defoamer, and stir to mix evenly;

[0084] 3. While stirring, add pigment, filler and other coating additives except leveling agent, antioxidant and anti-ultraviolet agent in turn, and then disperse at high speed (1500rpm) for 30min;

[0085] 4. Grind the mixed slurry into a sand mill until the fineness is ≤35μm;

[0086] 5. Add leveling agent, antioxidant, anti-ultraviolet agent and remaining active diluent to the above-ground slurry under stirring, adjust the color with appropriate color paste, and then disperse at high speed (1500rpm) for 30min;

[0087] 6. Packing to obtain the finished product.

[0088] The preparation method of the component B of the solvent-free coating can directly select a suitable curing agent and then package it to obtain the finished product.

[0089] The present invention finally relates to the application of a two-component aspartame polyurea coating based on HBPSi-AP as a heavy-duty anticorrosive coating, including a high-solid solvent-based coating and a solvent-free coating.

[0090] The present invention relates to the application of a high-solid solvent-based two-component aspartame polyurea coating based on HBPSi-AP, which is characterized in that the coating can be directly sprayed on a metal base surface that has been subjected to surface grinding, sandblasting or shot blasting without the aid of a primer coating. For example:

[0091] 1 Take a carbon steel plate with a specification of 200×150×3mm, grind, sandblast or shot blast the front side until the surface is bare metal color, and then blow away the dust on the surface. 2 Weigh the A and B components of the high solid solvent-based two-component asparagine polyurea coating based on HBPSi-AP involved in the patent of the present invention respectively according to the proportion, and then mix and stir well. Finally, adjust the viscosity of the mixture with a small amount of environmentally friendly solvent according to the usage habits.

[0092] 3. Put the mixed paint with adjusted viscosity into the material tank of the air spray gun for spraying. The air pressure and nozzle diameter required by the spray gun are adjusted according to the common experience and habits in the field of coating technology.

[0093] 4 During spraying, control the wet film thickness on the front side of the steel plate to 150-180μm to ensure the dry film thickness is 120-150μm.

[0094] 5 After the wet film is flash-dried for 10 minutes, it can be cured at room temperature for 2-4 hours, or it can be cured in an oven at 80℃ for 30 minutes.

[0095] The present invention relates to the application of a solvent-free two-component aspartame polyurea coating based on HBPSi-AP, which is characterized in that the coating can be directly sprayed on a metal base surface that has been subjected to surface grinding, sandblasting or shot blasting without the aid of a primer coating. For example:

[0096] 1 Take a carbon steel plate with a specification of 200×150×3mm, grind, sandblast or shot blast the front side until the original metal color is exposed, and then blow away the dust on the surface.

[0097] 2 Use a variable ratio two-component high-pressure polyurea sprayer (such as Wagner's TAITAN sprayer) or a low-pressure polyurea sprayer (such as Beijing Huaqing Machinery Equipment Co., Ltd.'s two-component low-pressure polyurea sprayer), and set the mixing ratio of A and B components of the solvent-free two-component asparagus polyurea coating based on HBPSi-AP and the heating temperature of the sprayer according to the actual requirements of the coating. The precautions and key points of machine spraying are implemented according to the conventional two-component spray polyurea construction technology.

[0098] 3 During spraying, control the wet film thickness on the front side of the steel plate to 150-180μm to ensure the dry film thickness is 120-150μm.

[0099] 5 The wet film can be cured into a film by leaving it at room temperature for 1-2 hours, or by baking it in an oven at 80℃ for 30 minutes.

[0100] Beneficial Effects

[0101] 1 The present invention patent invents a HBPSi-AP, which is characterized by constructing the Si-O-Si skeleton of polysiloxane into a highly branched and three-dimensional hyperbranched structure, and introducing it into the polymer structure of traditional aspartic acid polyurea through aspartic acid ester end groups. This significantly improves the adhesion of aspartic acid ester polyurea coating to the metal substrate as a thick paste "bottom-to-bottom" coating, and also surprisingly improves the scratch and salt spray resistance of the coating. Its main mechanism is: a. The hyperbranched spatial structure has many reactive sites, which makes the curing reaction balanced and uniform, and has an "isotropic" effect, thus avoiding the disadvantage of linear structure coating film with large internal stress and easy shrinkage, thereby overcoming the disadvantage of aspartic acid polyurea, especially solvent-free polyurea coating film, which affects the adhesion on the metal substrate due to excessive shrinkage.

[0102] b. The hyperbranched spatial structure avoids the phenomenon of intramolecular entanglement that is easy to occur in linear structures, making the resin have low viscosity and good fluidity, which is beneficial to improving the wettability of aspartame polyurea coatings, especially solvent-free aspartame polyurea coatings, to the base surface, thereby improving adhesion.

[0103] The Si-O-Si skeleton structure in polysiloxane has excellent anti-penetration, chemical corrosion resistance, temperature change resistance and aging resistance, and can also effectively improve the shrinkage resistance of polymer coatings. In addition, the Si-OH and Si-O-Et bonds contained in the macromolecule can increase the chemical bonding force of the coating to the surface of the substrate.

[0104] On the one hand, the d-terminated aspartic acid ester active group introduces the hyperbranched polysiloxane into the polyurea polymer structure. On the other hand, while improving the compatibility of the system, it also maintains the excellent physical and chemical properties and rapid curing process performance of the polyurea coating.

[0105] 2 The HBPSi-AP invented in the present invention is firstly secondary amination of γ-aminopropyltriethoxysilane (coupling agent KH550), and then hydrolyzed and condensed. The whole preparation process is short, simple to operate, green and environmentally friendly, and KH550 is widely available and belongs to low-cost siloxane. Therefore, the preparation technology is economical, reliable, practical, and can be used for industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0106] Figure 1 Infrared spectrum of diethyl maleate

[0107] Figure 2 KH550 infrared spectrum

[0108] Figure 3 IR spectrum of aspartic acid ester-capped n-propyltriethoxysilane;

[0109] Figure 4 IR spectrum of aspartic acid ester-capped hyperbranched polysiloxane (HBPSi-AP). DETAILED DESCRIPTION

[0110] Table 1 Main raw materials used in the examples

[0111]

[0112] Main test equipment and analytical test instruments used in the examples

[0113] 1 Fourier transform infrared spectrometer WAF-530 (Beijing North Branch Rayleigh Analytical Instrument Co., Ltd.)

[0114] 2Automatic Potentiometric Titrator AT-1 (Shanghai Hegong Scientific Instrument Co., Ltd.)

[0115] 3. Variable ratio two-component low-pressure polyurea sprayer (Beijing Huaqing Machinery Equipment Co., Ltd.)

[0116] 4Coating Thickness Gauge MC-3000S-FN (Jining Kedian Instrument Co., Ltd.)

[0117] 5. Digital hydraulic pull-off adhesion tester PosiTestAT-A (DeFesko, USA)

[0118] 6 Neutral Salt Spray Test Chamber LRHS-412-RY (Shanghai Linpin Instrument Co., Ltd.)

[0119] Example 1 Preparation of HBPSi-AP

[0120] The first step is the preparation of aspartic acid ester-terminated n-propyltriethoxysilane

[0121] In a 500mL four-necked glass reaction bottle equipped with an electric stirrer, a thermometer, a reflux condenser, a constant pressure dropping funnel and a nitrogen conduit, add 221g of γ-aminopropyltriethoxysilane (KH550), and then introduce nitrogen to remove oxygen in the reaction bottle. Turn on the stirring and gradually raise the temperature to 45-50°C, and begin to drop 173g of diethyl maleate through the constant pressure dropping funnel. During the 30-40min dropwise addition time, control the heat release so that the temperature does not exceed 60°C. Thereafter, continue the reaction at 60±2°C for 12 hours under nitrogen protection. Finally, raise the temperature to 80°C and evacuate for 30min to remove unreacted small molecules. After cooling, aspartic acid ester-terminated n-propyltriethoxysilane (see Figure 3 infrared spectrum of ).

[0122] contrast Figure 1 The infrared spectrum of diethyl maleate is Figure 3 Visible, infrared absorption spectrum at 1644cm -1 The absorption peak at has disappeared. Figure 2 The infrared spectrum of KH550 is Figure 3 See, at 3400-3500cm -1 The primary amino doublet at 3338 cm -1 The secondary amino singlet at 1079 cm indicates that the double bond of diethyl maleate has successfully reacted with the primary amino group of KH550 by Michael addition reaction. -1 The absorption peak at is the bending vibration of Si-OC.

[0123] Step 2 Preparation of HBPSi-AP

[0124] In a 500mL three-necked glass reaction bottle equipped with an electric stirrer, a thermometer, a reflux condenser and a nitrogen conduit, 197g of the above-mentioned aspartic acid ester-terminated n-propyltriethoxysilane and 197g of ethanol were weighed respectively, and stirring was started to dissolve them in each other. Nitrogen was introduced to remove oxygen from the reaction bottle, and then 11.7g of deionized water was added, the temperature was raised to 60°C, and refluxed for 4h under nitrogen protection. After the reaction was completed, small molecules such as ethanol and water were removed by a rotary evaporator, and the obtained colorless viscous oil was HBPSi-AP (see Figure 2 The average amino equivalent of the product was 185 as determined by potentiometric titration.

[0125] Depend on Figure 4 It can be seen that compared with Figure 3 , infrared absorption spectrum at 1072-1172cm -1 There is an obvious shift of the absorption peak at 3453 cm -1 A relatively obvious absorption peak appeared near the OH stretching vibration. The above two changes indicate that Si-OC has undergone hydrolysis and condensation, and hyperbranched polysiloxane has been successfully synthesized.

[0126] Example 2 Preparation of components A and B in a high-solid solvent-based two-component coating based on HBPSi-AP

[0127] The preparation of the high solid solvent-based two-component coating based on HBPSi-AP and its control example are carried out according to the proportions listed in the formula of the resin component (component A) in Table 2 and the proportions listed in the formula of the curing agent component (component B) in Table 3. All components in the table are measured by weight.

[0128] Table 2 High solid solvent-based resin component (component A) formula

[0129] Serial number Ingredients G1 G2 G3 G4 G5 G6 1 HBPSi-AP 25 25 25 30 -- -- 2 NH1520 10 8 8 5 10 10 3 NH 1420 -- 2 -- 25 20 4 NH2850 -- 2 -- -- -- 5 5 Environmentally friendly solvents 6 6 6 6 6 6 6 Dispersants 3 3 3 3 3 3 7 Titanium dioxide 9 9 9 9 9 9 8 Functional fillers 25 25 25 25 25 25 9 Dewatering agent 4 4 4 4 4 4 10 talcum powder 3 3 3 3 3 3 11 Barium sulfate 9 9 9 9 9 9 12 Environmentally friendly solvents 2 2 2 2 2 2 13 Leveling agent 0.8 0.8 0.8 0.8 0.8 0.8 14 Antioxidants 1.5 1.5 1.5 1.5 1.5 1.5 15 UV protection agent 1 1 1 1 1 1 16 Black pulp 0.7 0.7 0.7 0.7 0.7 0.7 17 Total weight 100 100 100 100 100 100 18 Average equivalent 592 592 591 559 797 816

[0130] Table 3 Formula of high solid solvent-based curing agent component (component B)

[0131]

[0132]

[0133] in:

[0134] Preparation of G1-G4 and Comparative Example G5-G6 in Component A

[0135] Preparation method

[0136] 1 According to the G1 formula in Table 2, first put the raw materials No. 1-6 into the container in sequence and stir them thoroughly.

[0137] 2 While stirring, add the raw materials No. 7-11 in sequence, then increase the speed to 2000rpm and disperse at high speed for 30 minutes.

[0138] 3. Put the high-speed dispersed slurry into the sand mill for grinding until the fineness reaches ≤35μm and then discharge.

[0139] 4 While stirring, add the raw materials No. 12-15 in sequence, then add the color paste raw material No. 16 for precise color adjustment, and then disperse at high speed (2000rpm) for 30 minutes to obtain the G1 component in component A.

[0140] Components G2-G4 and G5-G6 in component A of the comparative example were prepared according to the above steps respectively.

[0141] Preparation of GH1-GH3 components in component B:

[0142] Preparation method

[0143] According to the formula of GH1 in Table 2, the raw materials of each serial number are mixed evenly in a suitable container to obtain component B GH1.

[0144] The components GH2-GH3 of component B were prepared by referring to the above steps.

[0145] Example 3 Preparation and testing of paint films of high-solid solvent-based two-component coatings GF1-GF4 and comparative examples GF5-GF6 based on HBPSi-AP

[0146] Preparation method

[0147] 1 According to the GF1 formula in Table 4, weigh appropriate amounts of components A and B, then mix and stir thoroughly. Finally, adjust the viscosity of the mixture with a small amount of environmentally friendly solvent according to usage habits.

[0148] 2. Put the mixed paint with adjusted viscosity into the material tank of air spray gun for spraying. The air pressure and nozzle diameter required by the spray gun shall be adjusted according to the common experience and custom in the field of coating technology.

[0149] 3 During spraying, control the wet film thickness on the front side of the steel plate to 150-180μm to ensure the dry film thickness is 120-150μm.

[0150] 4 After the wet film is flash-dried for 10 minutes, it can be cured into a film at room temperature for 2-4 hours, or it can be placed in an oven at 80℃ for 30 minutes to cure into a film, and the GF1 paint film test plate is obtained.

[0151] 5 Place it at room temperature for 7 days, then do adhesion test and scratch salt spray test.

[0152] The paint films of GF2-GF4 and comparative examples GF5-GF6 were obtained according to the above steps and subjected to adhesion test and scratch salt spray test.

[0153] The preparation and testing of the paint film of the high-solid solvent-based two-component coating based on HBPSi-AP and its control example were carried out according to the proportions listed in the paint making formula in Table 4. All components in the table are measured by weight.

[0154] Table 4 Paint formulations of solvent-based two-component coatings based on HBPSi-AP and their control examples

[0155]

[0156]

[0157] Each paint film in Table 4 was sprayed directly on the steel plate base surface in the form of "base-to-surface integration", and the average film thickness of each coating, the adhesion to the metal base surface, and the scratch and salt spray resistance performance were tested.

[0158] Prepare the base material by taking a sufficient number of carbon steel plates with a specification of 200×150×3mm, grinding, sandblasting or shot blasting on the front side until the surface reveals the original metal color, then blow away the surface dust and set aside.

[0159] The pull-off adhesion test shall be carried out in accordance with GB / T 5210-2006.

[0160] For the scratch neutral salt spray test, first scratch the metal plate coating according to GB / T 30786-2014, and then perform the scratch salt spray test according to GB / T10125-2012.

[0161] Example 4 Preparation and testing of components A and B of a solvent-free two-component coating based on HBPSi-AP and its control example

[0162] The preparation and testing of the solvent-free two-component coating based on HBPSi-AP and its control example were carried out according to the proportions listed in the formula of the resin component (component A) in Table 4 and the proportions listed in the formula of the curing agent component (component B) in Table 6. All components in the table are measured by weight.

[0163] Table 5 Solvent-free resin component (component A) formula

[0164] Serial number Ingredients W1 W2 W3 W4 W5 W6 1 HBPSi-AP 25 25 25 30 -- -- 2 NH1520 10 8 8 5 10 10 3 NH 1420 -- 2 -- 25 20 4 NH2850 -- 2 -- -- -- 5 5 Active diluent 5 5 5 5 5 6 Dispersants 4 4 4 4 4 4 7 Titanium dioxide 9 9 9 9 9 9 8 Functional fillers 25 25 25 25 25 25 9 Dewatering agent 4 4 4 4 4 4 10 talcum powder 3 3 3 3 3 3 11 Barium sulfate 11 11 11 11 11 11 12 Organic spray soil 1 1 1 1 1 1 13 Leveling agent 0.8 0.8 0.8 0.8 0.8 0.8 14 Antioxidants 1.5 1.5 1.5 1.5 1.5 1.5 15 UV protection agent 1 1 1 1 1 1 16 Black pulp 0.7 0.7 0.7 0.7 0.7 0.7 17 Total weight 100 100 100 100 100 100 18 Average equivalent 592 592 591 559 797 816

[0165] Table 6 Formula of solvent-free curing agent component (component B)

[0166]

[0167]

[0168] in:

[0169] The preparation method of W1 in component A is as follows:

[0170] 1 According to the W1 formula in Table 5, first put the raw materials of sequence numbers 1-6 into the container in sequence and stir them thoroughly.

[0171] 2 While stirring, add the raw materials No. 7-12 in sequence, then increase the speed to 2000rpm and disperse at high speed for 30 minutes.

[0172] 3. Put the high-speed dispersed slurry into the sand mill for grinding until the fineness reaches ≤35μm and then discharge.

[0173] 4 While stirring, add the raw materials of sequence numbers 13-15 in sequence, then add the color paste raw material of sequence number 16 for precise color adjustment, and then disperse at high speed (2000rpm) for 30 minutes to obtain component B W1.

[0174] W2-W4 and comparative examples W5-W6 were prepared according to the above steps respectively.

[0175] Preparation method of component B WH1:

[0176] According to the formula of WH1 in Table 6, the raw materials of each serial number are mixed evenly in a suitable container to obtain component A WH1.

[0177] WH2-WH3 were prepared as above.

[0178] Example 5 Preparation and testing of paint films of WF1-WF4 and control examples WF5-WF6 based on solvent-free two-component coatings of HBPSi-AP

[0179] Preparation method

[0180] 1 Using a variable ratio two-component low-pressure polyurea sprayer, the mixing ratio of components A (resin component) and B (curing agent component) is adjusted according to the volume mixing ratio in formula WF1 in Table 7, and the heating temperature of the sprayer is set to 55°C for component A and 45°C for component B. The remaining operating instructions and precautions of the sprayer are implemented according to the requirements of the sprayer and the conventional two-component spray polyurea construction technology.

[0181] 2 During spraying, control the wet film thickness on the front side of the steel plate to 150-180μm to ensure the dry film thickness is 120-150μm.

[0182] 3 The wet film can be cured into a film by being placed at room temperature for 1-2 hours, or placed in an oven at 80°C for 30 minutes to cure into a film, and the WF1 paint film test plate is obtained.

[0183] 4 Leave at room temperature for 7 days and then test.

[0184] WF2-WF6 were prepared and tested according to the same steps.

[0185] The preparation and testing of the paint film of the solvent-free two-component coating based on HBPSi-AP and its control example were carried out according to the proportions listed in the paint making formula in Table 7. All components in the table are measured by weight.

[0186] Table 7: Paint formulations of solvent-free two-component coatings based on HBPSi-AP and their control examples

[0187]

[0188]

[0189] Each paint film in Table 7 was sprayed directly on the steel plate base surface in the form of "base-to-surface integration", and the average film thickness of each coating, the adhesion to the metal base surface, and the scratch and salt spray resistance performance were tested.

[0190] Prepare the base material by taking a sufficient number of carbon steel plates with a specification of 200×150×3mm, grinding, sandblasting or shot blasting on the front side until the surface reveals the original metal color, then blow away the surface dust and set aside.

[0191] The pull-off adhesion test shall be carried out in accordance with GB / T 5210-2006.

[0192] For the scratch neutral salt spray test, first scratch the metal plate coating according to GB / T 30786-2014, and then perform the scratch salt spray test according to GB / T10125-2012.

[0193] Summary:

[0194] Table 8 records the test results of each coating test plate in the relevant embodiments and control examples of the above-mentioned high-solid solvent-based coatings and solvent-free coatings, including the average coating thickness, adhesion (pull-out) and scratch neutral salt spray test.

[0195] Table 8 Example test results list

[0196]

[0197] As shown in Table 8, the two-component polyurea coatings based on HBPSi-AP involved in the present invention can achieve a coating thickness of more than 120μm at one time, whether it is a high-solid solvent-based coating or a solvent-free coating. At the same time, as a thick paste-type "bottom-to-bottom" coating, their adhesion to the metal substrate exceeds 12mPa., which is significantly improved compared with the control example. And their coatings have been tested for scratch resistance to neutral salt spray, and the high-solid solvent-based coating and the solvent-free coating have exceeded 700 hours and 800 hours respectively, which is an amazing improvement compared with the control example.

Claims

1. An aspartic acid ester-terminated hyperbranched polysiloxane HBPSi-AP, characterized in that: It is a highly branched and three-dimensional hyperbranched resin composed of a polysiloxane Si-O-Si skeleton, and contains secondary amino groups that can further react with isocyanate for curing. Its structural formula is shown in Formula 1: in:

2. The method for preparing an aspartic acid ester-terminated hyperbranched polysiloxane HBPSi-AP according to claim 1, characterized in that: It has the following steps: A. γ-aminopropyltriethoxysilane and diethyl maleate are subjected to Michael addition reaction to obtain n-propyltriethoxysilane terminated with aspartic acid ester, and the reaction formula is shown in Formula 2: B. The aspartic acid ester-terminated n-propyltriethoxysilane is subjected to hydrolysis and condensation reaction to obtain HBPSi-AP resin, and the reaction process is shown in Formula 3: in:

3. The method for preparing an aspartic acid ester-terminated hyperbranched polysiloxane HBPSi-AP according to claim 2, characterized in that: A. Take γ-aminopropyltriethoxysilane and diethyl maleate in a molar ratio of 1:1.0-1:1.005, and under nitrogen protection at 45-50°C, first drop diethyl maleate into γ-aminopropyltriethoxysilane to carry out Michael addition reaction, and control the drop reaction temperature not to exceed 65°C; after the drop addition is completed, keep a constant temperature of 60±2°C for reaction for 8-20 hours; after the reaction is completed, cool to below 40°C to obtain n-propyltriethoxysilane capped with aspartic acid ester; B. Firstly, aspartic acid ester-terminated n-propyl triethoxysilane is dissolved in an ethanol solvent at a weight ratio of 1:1, and then nitrogen is introduced to exclude oxygen, and deionized water is added under stirring; the amount of deionized water added is in a molar ratio of 1:1-1.3:1 to aspartic acid ester-terminated n-propyl triethoxysilane; then, reflux reaction is carried out at 55-60°C for 4 hours; after the reaction is completed, ethanol, water and other small molecules are removed by vacuum to obtain a colorless, low-viscosity oily product, namely HBPSi-AP.

4. A two-component aspartame polyurea coating based on HBPSi-AP, characterized in that: It includes high solid solvent-based coatings and solvent-free coatings.

5. The two-component aspartame polyurea coating based on HBPSi-AP according to claim 4, characterized in that: The high-solid solvent-based two-component aspartame polyurea coating contains component A and component B; The component A, i.e. the resin component, is composed of the following components in weight percentage based on the total weight of the component A: (1) at least 25% by weight of HBPSi-AP; (2) up to 10% by weight of aspartic acid ester resin; (3) up to 55% by weight of pigments, fillers and coating additives; (4) up to 10% by weight of an environmentally friendly solvent; The component B, i.e. the curing agent component, is composed of the following components in the above weight percentages based on the total weight of the component B: (1) at least 90% by weight of an isocyanate curing agent; (2) up to 10% by weight of an environmentally friendly solvent; The weight mixing ratio of the A and B components is 2:1-2.5:1, and the construction solid content is 80-85%.

6. The two-component aspartame polyurea coating based on HBPSi-AP according to claim 4, characterized in that: The solvent-free two-component aspartame polyurea coating contains component A and component B; The component A, i.e. the resin component, is composed of the following components by weight percentage based on the total weight of the component A: 1 at least 25% by weight of HBPSi-AP; 2 up to 15% by weight of aspartic acid ester resin; 3. Up to 55% by weight of pigments, fillers and coating additives; 4. Up to 5% by weight of a reactive diluent; Its component B, i.e., the curing agent component, is composed of a solvent-free isocyanate curing agent in terms of weight percentage based on the total weight of component B; The weight mixing ratio of the A and B components is 2.5:1-2.7:1; the construction solid content is 98-100%.

7. The two-component aspartame polyurea coating based on HBPSi-AP according to claim 5, characterized in that: In the component A of the high solid solvent-containing two-component aspartame polyurea coating: Aspartic acid ester resins include Covestrode's Desmophen NH1420, NH1520, NH1220 and NH2850, which can be used alone or mixed with each other in any proportion; The pigments and fillers include functional fillers and modified pigments and fillers, wherein the functional fillers include zinc phosphate, zinc phosphomolybdate, zinc aluminum phosphate and mica powder, which can be used alone or mixed with each other in any proportion, and the total amount used is 15-30% of the total weight of component A; the modified pigments and fillers include titanium dioxide, calcium carbonate, barium sulfate, talcum powder, carbon black and iron red, which can be used alone or mixed with each other in any proportion, and the total amount used is 15-30% of the total weight of component A; The coating additives include dispersants, leveling agents, defoamers, thixotropic agents, water removers, antioxidants and anti-ultraviolet agents, and the total amount used is 3-10% of the total weight of component A; The environmentally friendly solvents include propylene glycol methyl ether acetate, a mixture of dimethyl succinate, dimethyl glutarate and dimethyl adipate, ethyl 3-ethoxypropionate and butyl acetate, which can be used alone or mixed in any proportion; in component B: the isocyanate curing agent is an aliphatic isocyanate curing agent or an aromatic isocyanate curing agent, including hexamethylene diisocyanate HDI and its trimer, HDI biuret, isophorone diisocyanate IPDI and its trimer, dicyclohexylmethane diisocyanate HMDI, diphenylmethane diisocyanate MDI, liquefied MDI, toluene diisocyanate TDI, TDI dimer, TDI trimer and TDI modified prepolymer; they can be used alone or mixed in any proportion; Environmentally friendly solvents include propylene glycol methyl ether acetate PMA, a mixture of dimethyl succinate, dimethyl glutarate and dimethyl adipate DBE, ethyl 3-ethoxypropionate EEP, and butyl acetate BAC; they can be used alone or mixed in any proportion. The A and B components are calculated according to the amino equivalent and isocyanate equivalent in the A and B components, and the ratio [NH] / [NCO] ＝1:1.05-1:1.1； The component A is prepared according to the following steps: (1) Weigh HBPSi-AP and appropriate aspartic acid ester resin into a suitable container and stir to mix evenly; (2) Add appropriate amount of solvent, dispersant and defoamer, and stir to mix evenly; (3) While stirring, add pigment, filler and other coating additives except leveling agent, antioxidant and anti-ultraviolet agent in sequence, and then disperse at a high speed of 2000 rpm for 30 minutes; (4) Grinding the mixed slurry in a sand mill until the fineness is ≤35 μm; (5) Add a leveling agent, an antioxidant, an anti-ultraviolet agent and the remaining solvent to the above-ground slurry under stirring, adjust the color with a suitable color paste, and then disperse at a high speed of 2000 rpm for 30 minutes; (6) Packaging to obtain the finished product; The component B is prepared by the following steps: the curing agent and the environmentally friendly solvent are directly mixed evenly, and then packaged to obtain the finished product.

8. The two-component aspartame polyurea coating based on HBPSi-AP according to claim 6, characterized in that: In the solvent-free two-component aspartame polyurea coating, component A comprises: Aspartic acid ester resins include Covestrode's Desmophen NH1420, NH1520, NH1220 and NH2850, which can be used alone or mixed with each other in any proportion; The pigments and fillers include functional fillers and modified pigments and fillers, wherein the functional fillers include zinc phosphate, zinc phosphomolybdate, zinc aluminum phosphate and mica powder, which can be used alone or mixed with each other in any proportion; the total amount used is 15-30% of the total weight of component A; the modified pigments and fillers include titanium dioxide, calcium carbonate, barium sulfate and talcum powder, carbon black, and iron red, which can be used alone or mixed with each other in any proportion; the total amount used is 15-30% of the total weight of component A; The coating additives include dispersants, leveling agents, defoamers, thixotropic agents, water removers, antioxidants and anti-ultraviolet agents; their total amount is 3-10% of the total weight of component A; The active diluents include propylene carbonate PC, γ-butyrolactone, and acetyl tributyl citrate ATBC, which can be used alone or mixed in any proportion. In component B: the isocyanate curing agent is an isocyanate curing agent, an aliphatic isocyanate curing agent or an aromatic isocyanate curing agent, including hexamethylene diisocyanate HDI and its trimer, HDI biuret, isophorone diisocyanate IPDI and its trimer, dicyclohexylmethane diisocyanate HMDI, diphenylmethane diisocyanate MDI, liquefied MDI, toluene diisocyanate TDI, TDI dimer, TDI trimer and TDI modified prepolymer; they can be used alone or mixed with each other in any proportion; The A and B components are calculated according to the amino equivalent and isocyanate equivalent in the A and B components, and the ratio [NH] / [NCO] ＝1:1.05-1:1.1； Component A is prepared by the following steps: (1) Weigh HBPSi-AP and appropriate aspartic acid ester resin into a suitable container and stir to mix evenly; (2) Add appropriate amount of active diluent, dispersant and defoamer, and stir to mix evenly; (3) While stirring, add pigment, filler and other coating additives except leveling agent, antioxidant and anti-ultraviolet agent in sequence, and then disperse at a high speed of 1500 rpm for 30 minutes; (4) Grinding the mixed slurry in a sand mill until the fineness is ≤35 μm; (5) Add leveling agent, antioxidant, anti-ultraviolet agent and remaining active diluent to the above-ground slurry under stirring, adjust the color with appropriate color paste, and then disperse at a high speed of 1500 rpm for 30 minutes; (6) Packaging to obtain the finished product; Component B is directly mixed with a suitable curing agent and then packaged to obtain the finished product.

9. Use of the two-component aspartame polyurea coating based on HBPSi-AP according to any one of claims 4 to 8 as a heavy-duty anti-corrosion coating.

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