An aspartate-terminated hyperbranched polysiloxane and heavy-duty anticorrosive coating material thereof, and a preparation method and application thereof

Abstract

The application belongs to the field of coating, and particularly relates to aspartate-terminated hyperbranched polysiloxane and heavy-duty anticorrosive coating thereof, and a preparation method and application thereof. The aspartate-terminated hyperbranched polysiloxane is a hyperbranched resin composed of a polysiloxane Si-O-Si skeleton and having three-dimensional space, and contains a secondary amino group capable of curing reaction with isocyanate. The preparation method comprises two steps: 1. Michael addition reaction of gamma-aminopropyl triethoxysilane and diethyl maleate to obtain n-propyl triethoxysilane terminated by aspartate; and 2. Hydrolysis and condensation to obtain aspartate-terminated hyperbranched polysiloxane. Thus, aspartate coating of a high solid content solvent type and a solvent-free system can be prepared, and the aspartate coating is used as heavy-duty anticorrosive coating of a "bottom and surface in one".

Description

TECHNICAL FIELD

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

[0002] In the past decade, two-component polyaspartic ester polyurea coatings have been increasingly concerned and applied in various fields of the national economy, which is mainly due to the special molecular structure of aspartic ester and the moderate reactivity of secondary amino groups, so that aspartic polyurea coatings have excellent characteristics such as high solid content, rapid curing at room temperature, aging resistance, moderate corrosion resistance, impact resistance, wear resistance and the like, and thus are a new type of high-performance environmentally friendly coatings. So far, the product forms of two-component polyaspartic ester polyurea coatings have covered high solid content (construction solid content greater than 75%) systems, solvent-free (construction solid content greater than 98%) systems and waterborne systems, and have been applied in fields such as building waterproofing, floor paving, furniture and wooden wares, steel structure protection, automobile and ship manufacturing, engineering machinery, mine machinery and automobile maintenance.

[0003] However, ordinary aspartic ester polyurea coatings still have many obvious deficiencies, which are mainly due to the small molecular weight of aspartic ester and the relatively high content of ester bonds, so that the hydrophobicity and permeation resistance of the coating film are not good. At the same time, the traditional polyaspartic ester polyurea is mainly in a linear structure, so the shrinkage rate of the coating film after curing is large, which can be as high as 1-1.5%, which significantly affects the adhesion of aspartic polyurea coatings, especially to rigid metal substrates. Due to the above reasons, ordinary aspartic polyurea coatings cannot be directly used in industrial areas with very high corrosion environment (C5 and above), but can only be used in environments with corrosion below C3, and still need to be used in combination with a primer, so the application range is limited.

[0004] As is known to all, as a new type of energy-saving and environmentally friendly coating, aspartic polyurea coatings can not only be used as thick paste type coatings (one-time coating thickness greater than 150 μm), but also have aging resistance, physical and mechanical properties, friction resistance and construction performance that are incomparable to traditional thick paste type coatings. Therefore, by modifying the traditional aspartic ester resin or improving the traditional aspartic polyurea coating formula, the deficiencies of aspartic polyurea can be overcome, so that aspartic polyurea coatings can be applied in heavy-duty industrial corrosion fields in the form of "primer and surface in one", which not only expands the application range of aspartic polyurea coatings, but also is an actual action to implement the energy-saving, environmentally friendly and high-efficiency concept in the coating industry and to practice the "green and sustainable development" national strategy. In fact, in recent years, the focus of aspartic polyurea coating research and development has been around "primer and surface in one" and heavy-duty anticorrosion applications, and the number of patent reports during this period has also increased.

[0005] Chinese patent CN112210279 reports a one-coat aspartic polyurea coating. Its feature is to use a lightly branched polyester polyol compounded with a polyaspartic ester resin, supplemented by active diluents and high-boiling solvents to adjust the viscosity and operable time of the coating system. This patent mainly focuses on process performance and film appearance, such as moderate viscosity, high-pressure airless spraying, one-time film thickness of 150-350 μm, and smooth and flat surface, etc. However, the reactivity of hydroxyl groups with isocyanate curing agents is much lower than that of secondary amino groups, so the addition of hydroxyl-containing (polyester polyol) substances to the secondary amino aspartic resin system will cause inconsistencies in curing, composition, and performance, resulting in a decline in the overall performance of the coating film.

[0006] US patent US20060058492 reports a thiol-modified polyurea-polyurea coating. Its feature is to use a thiol-terminated aliphatic polysulfide compound (ALIPS) or other thiol-terminated polymers as the main resin, and to use small molecule amines as chain extenders, and to react with isocyanate to obtain a sulfur-containing polyurea-polyurea coating film. It is claimed that as a heavy-duty coating, it can significantly improve the corrosion resistance and permeation resistance of the coating film after long-term contact with organic solvents. However, this thiol-terminated polymer is expensive, and both the raw materials and the coating film itself have a distinct sulfur odor.

[0007] US patent USP7247351 discloses a silicone-modified polyurea coating. Its feature is to obtain an amino-terminated polysiloxane by reacting a three-epoxy-terminated polysiloxane with a polyamine. This patent claims that by introducing silicon elements into the molecular structure of the chain extender, the adhesion, corrosion resistance, and aging resistance of the polyurea coating can be improved. At the same time, the branched chain structure of the silicon-containing chain extender further reduces the shrinkage of the coating film. However, the three-epoxy-terminated polysiloxane used in this patent is extremely rare and cannot be practically applied.

[0008] Chinese patent CN113637398 reports a bottom-surface integrated aspartic polyurea heavy-duty anticorrosive coating. Its feature is that the trisilanol is first obtained by hydrolysis of trichlorosilane, then reacted with diisocyanate to obtain a silicon-containing triisocyanate, then reacted with a binary primary amine to obtain a silicon-containing ternary primary amine, and finally reacted with maleic acid diethyl ester by Michael addition to obtain a silicon-containing ternary aspartic acid ester. This patent claims that, on the one hand, due to the existence of hyperbranched structure, the aspartic polyurea coating increases more mild reactive sites, makes the curing reaction more uniform, produces less stress, thus reduces the shrinkage rate of the cured coating film and improves 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 film are greatly improved. In terms of the idea of solving the problems of traditional polyurea, it is undeniable that the starting point of this patent is commendable, that is, on the one hand, to increase the branching degree of the resin, and on the other hand, to modify with silicon element. But the synthesis route of the so-called hyperbranched aspartic acid resin selected by this 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 be practically applied.

[0009] As is known to all, hyperbranched polymer is a polymer with a highly branched structure, whose branching degree is higher than that of general branched polymer and lower than that of dendrimer. Compared with linear polymer, hyperbranched polymer contains no or little linear structure and has no chain entanglement, so it has very low viscosity, good flowability, solubility and film-forming property. Hyperbranched polymer has high branching degree, which breaks the regularity and symmetry of traditional linear polymer, and the cured coating film has an "isotropic" effect, thus reducing the shrinkage rate of the cured coating film. In addition, the terminal functional groups of hyperbranched polymer have high reactivity, which can be used for further reaction to prepare various high-performance polymer materials. The unique molecular structure, excellent thermal and mechanical properties, and potential application prospects make hyperbranched polymer have been used in viscosity modifier, solvent-free coating, curing agent and adhesive of thermosetting material fields, etc.

[0010] To this end, the application combines the excellent mechanical properties, corrosion resistance, temperature resistance and good biocompatibility of polysiloxane with the special structure of hyperbranched polymer, and invents an aspartic acid ester-terminated hyperbranched polysiloxane resin, and thus prepares an aspartic acid ester-terminated hyperbranched polysiloxane modified aspartic polyurea heavy-duty anticorrosive coating, including high solid content solvent-based coating and solvent-free coating. Test results show that the two-component aspartic polyurea coating based on aspartic acid ester-terminated hyperbranched polysiloxane can not only significantly improve the adhesion of aspartic acid ester polyurea coating as a thick paste type "bottom and surface in one" coating to the metal surface, but also surprisingly improve the scratch salt spray resistance of the coating, so that it can meet the requirements of the bottom and surface in one aspartic polyurea coating in the heavy-duty anticorrosive field such as oil pipeline valves, chemical storage tank inner walls, ocean wind power towers, container coating and mine support protection. SUMMARY

[0011] OBJECTIVE

[0012] In view of the fact that ordinary aspartic polyurea coating cannot be used in the industrial heavy-duty anticorrosive field, the application aims to provide a two-component aspartic polyurea coating based on aspartic acid ester-terminated hyperbranched polysiloxane, including high solid content solvent-based coating and solvent-free coating, so that it can meet the requirements of the industrial heavy-duty anticorrosive field for anticorrosive coatings, and can save the primer coating in the traditional coating process, realize the bottom and surface in one coating, save materials and improve efficiency.

[0013] TECHNICAL SCHEME

[0014] The application first relates to an aspartic acid ester-terminated hyperbranched polysiloxane; the application also relates to a preparation method of the aspartic acid ester-terminated hyperbranched polysiloxane; the application further relates to a two-component aspartic polyurea coating based on aspartic acid ester-terminated hyperbranched polysiloxane, including high solid content solvent-based coating and solvent-free coating; the application still further relates to a preparation method of the two-component aspartic polyurea coating based on aspartic acid ester-terminated hyperbranched polysiloxane, including high solid content solvent-based coating and solvent-free coating; and the application finally relates to an application of the two-component aspartic polyurea coating based on aspartic acid ester-terminated hyperbranched polysiloxane, including high solid content solvent-based coating and solvent-free coating.

[0015] The application first 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 be further cured with isocyanate, and its structural formula is as follows (Formula 1):

[0016]

[0017] In the formula,

[0018]

[0019] The present application also relates to a preparation method of HBPSi-AP, characterized in that it has the following two steps: 1. Michael addition reaction of γ-aminopropyl triethoxysilane (coupling agent KH550) and diethyl maleate to obtain n-propyl triethoxysilane capped with aspartate. The reaction formula is as follows (Formula 2):

[0020]

[0021] 2. Hydrolysis and condensation reaction of the above-mentioned n-propyl triethoxysilane capped with aspartate to obtain HBPSi-AP resin. The reaction process is as follows (Formula 3):

[0022]

[0023] Among them:

[0024]

[0025] The formula and process of Michael addition reaction of the above-mentioned γ-aminopropyl triethoxysilane (coupling agent KH550) and diethyl maleate can be performed according to the synthesis technology of aspartate, that is, the suitable molar ratio of KH550 to diethyl maleate is 1:1.0-1:1.005, preferably 1:1.0-1:1.002. Under nitrogen protection and low temperature (45-50°C), diethyl maleate is first added to KH550, and the dropwise reaction temperature is controlled to be not more than 65°C, preferably not more than 60°C. After the dropwise addition is completed, the temperature is kept at 60±2°C for 8-20 hours, preferably 10-15 hours. After the reaction is completed, the temperature is cooled to below 40°C, and n-propyl triethoxysilane capped with aspartate is obtained.

[0026] The preparation of HBPSi-AP resin from the above-mentioned n-propyl triethoxysilane capped with aspartate by hydrolysis and condensation method is carried out in the presence of deionized water and ethanol solvent. Triethoxysilane Si(OEt)3 is first hydrolyzed to form silanetriol Si(OH)3, and then polycondensed to form HBPSi-AP under the action of the solvent. The specific method is as follows: first, the n-propyl triethoxysilane capped with aspartate is dissolved in ethanol solvent at a weight ratio of 1:1, then nitrogen is introduced to remove 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, preferably 1:1-1.2:1, of n-propyl triethoxysilane capped with aspartate. Then, reflux at 55-60°C for 4 hours. After the reaction is completed, ethanol, water and other small molecular substances are removed by vacuum to obtain colorless and low viscosity oil product, which is HBPSi-AP.

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

[0028] The application relates to a high-solid solvent-based two-component aspartic polyurea coating based on HBPSi-AP.

[0029] The A component, namely the resin component, is composed of:

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

[0031] 2 at most 10% by weight of aspartic acid ester resin;

[0032] 3 at most 55% by weight of pigments, fillers and coating additives;

[0033] 4 at most 10% by weight of environment-friendly solvents,

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

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

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

[0037] 2 at most 10% by weight of environment-friendly solvents, and the above weight percentages are calculated based on the total weight of the B component.

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

[0039] The application relates to a solvent-free two-component aspartic polyurea coating based on HBPSi-AP.

[0040] The A component, namely the resin component, is composed of:

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

[0042] 2 at most 15% by weight of aspartic acid ester resin;

[0043] 3 at most 55% by weight of pigments, fillers and coating additives;

[0044] 4 at most 5% by weight of active diluents.

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

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

[0047] The isocyanate curing agent is solvent-free.

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

[0049] The application further relates to a preparation method of the HBPSi-AP-based two-component aspartic polyurea coating.

[0050] In the A component, suitable aspartic acid ester resins include, but are not limited to, Desmophen NH1420, NH1520, NH1220 and NH2850 of Covestrode, and the like, which can be used alone or in any proportion.

[0051] In the A component, suitable pigments and fillers include functional pigments and fillers and modified pigments and fillers, wherein the functional pigments and fillers include, but are not limited to, zinc phosphate, zinc phosphomolybdate, zinc aluminum phosphate and mica powder, and the like, which can be used alone or in any proportion; the total amount is 15-30% of the total weight of the A component, preferably 20-25%.

[0052] In the A component, suitable coating additives include, but are not limited to, dispersants, leveling agents, defoamers, thixotropic agents, water removal agents, antioxidants and ultraviolet light resistant agents, and the like, which can be selected according to the conventional technical requirements for high solid content coating systems; the total amount is 3-10% of the total weight of the A component, preferably 5-8%.

[0053] In the A component, 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), 3-ethoxyethyl propionate (EEP), butyl acetate (BAC), and the like, which can be used alone or in any proportion.

[0054] The suitable isocyanate curing agent in the above-mentioned B component is the isocyanate curing agent commonly used in polyurethane coatings or polyurea coatings in the field of coatings. They can be aliphatic isocyanate curing agents or aromatic isocyanate curing agents. They include, but are not limited to, hexamethylene diisocyanate (HDI) and its trimer, HDI biuret, isophorone diisocyanate (IPDI) and its trimer, dicyclohexyl methane diisocyanate (HMDI), diphenyl methane 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] The suitable environmentally friendly solvent in the above-mentioned B component includes, but is not limited to, propylene glycol methyl ether acetate (PMA), a mixture of dimethyl succinate, dimethyl glutarate and dimethyl adipate (DBE), 3-ethoxyethyl propionate (EEP), butyl acetate (BAC), etc. They can be used alone or mixed with each other in any proportion.

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

[0057] The preparation method of the A component of the above-mentioned high solid content solvent-based coating can be carried out according to the preparation technology of the corresponding resin component in the field of coatings today, i.e.:

[0058] 1. Measure the HBPSi-AP and the suitable aspartate resin into a suitable container and mix them uniformly under stirring;

[0059] 2. Add an appropriate amount of solvent and dispersant, defoaming agent, and mix them uniformly under stirring;

[0060] 3. Under stirring, add pigments, fillers, and other coating additives except leveling agent, antioxidant and ultraviolet light resistant agent, and then disperse them at high speed (2000 rpm) for 30 min;

[0061] 4. Grind the above-mentioned mixture slurry in a sand mill until the fineness is ≤35 μm;

[0062] 5. Under stirring, add leveling agent, antioxidant, ultraviolet light resistant agent and the remaining solvent to the above-mentioned ground slurry, and then disperse them at high speed (2000 rpm) for 30 min;

[0063] 6. Package, and the finished product is obtained.

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

[0065] The present application relates to a solvent-free two-component aspartic polyurea coating based on HBPSi-AP, characterized in that:

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

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

[0068] 2. at most 15% by weight of aspartic acid ester resin;

[0069] 3. at most 55% by weight of pigments and fillers and coating additives;

[0070] 4. at most 5% by weight of reactive diluents.

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

[0072] The B component, i.e. the curing agent component, is composed of:

[0073] a solvent-free isocyanate curing agent.

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

[0075] In the above A component, 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 A component, 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 the A component, preferably 20-25%. Suitable modified pigments and fillers include but are not limited to titanium dioxide, calcium carbonate, barium sulfate and talc, 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 the A component, preferably 20-25%.

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

[0078] Suitable active diluents in the A component 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] Suitable isocyanate curing agents in the B component are isocyanate curing agents commonly used in polyurethane coatings or polyurea coatings in the field of coatings. They can be aliphatic isocyanate curing agents or aromatic isocyanate curing agents. They include, but are 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 A and B components is calculated based on the amino equivalent and isocyanate equivalent in the A and B components, respectively, and makes 〔NH〕 / 〔NCO〕=1:1.05-1:1.1.

[0081] The preparation method of the A component of the solvent-free coating can refer to the preparation technology of the corresponding resin component in the field of coatings today, that is:

[0082] 1. Measure the HBPSi-AP and the appropriate aspartate resin into a suitable container and mix well under stirring;

[0083] 2. Add an appropriate amount of active diluent and dispersant, defoaming agent, and mix well under stirring;

[0084] 3. Under stirring, add pigments, fillers, and other coating additives except leveling agents, antioxidants, and ultraviolet light resistant agents in sequence, and then disperse at high speed (1500 rpm) for 30 min;

[0085] 4. Grind the above mixture slurry in a sand mill until the fineness is ≤35 μm;

[0086] 5. Under stirring, add leveling agents, antioxidants, ultraviolet light resistant agents, and the remaining active diluent to the above ground slurry, adjust the color with a suitable color paste, and then disperse at high speed (1500 rpm) for 30 min;

[0087] 6. Package, and the finished product is obtained.

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

[0089] The application finally relates to application of the HBPSi-AP-based two-component aspartic polyurea coating as heavy-duty coating, including high solid content solvent-based coating and solvent-free coating.

[0090] The application relates to application of the HBPSi-AP-based high solid content solvent-based two-component aspartic polyurea coating, and is characterized in that the coating can be directly sprayed on a metal surface treated by grinding, sand blasting or shot blasting without a primer coating.

[0091] 1A carbon steel plate with a size of 200x150x3mm is taken, and the front surface is treated by grinding, sand blasting or shot blasting until the surface is bare metal in original color, and then the surface dust is removed by air blowing.

[0092] 3The mixed paint with the adjusted viscosity is filled into a paint tank of an air spray gun, and the air pressure and the nozzle size of the spray gun are set and adjusted according to the experience and habit in the coating technical field.

[0093] 4During spraying, the wet film thickness of the wet film on the front surface of the steel plate is controlled to be 150-180μm, so that the dry film thickness is 120-150μm.

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

[0095] The application relates to application of the HBPSi-AP-based solvent-free two-component aspartic polyurea coating, and is characterized in that the coating can be directly sprayed on a metal surface treated by grinding, sand blasting or shot blasting without a primer coating.

[0096] 1A carbon steel plate with a size of 200x150x3mm is taken, and the front surface is treated by grinding, sand blasting or shot blasting until the surface is bare metal in original color, and then the surface dust is removed by air blowing.

[0097] 2A variable-ratio two-component high-pressure polyurea spraying machine (such as a TAITAN spraying machine of Wagner) or a low-pressure polyurea spraying machine (such as a two-component low-pressure polyurea spraying machine of Beijing Huading Machinery Equipment Co., Ltd.) is used, the mixing ratio of the HBPSi-AP-based solvent-free two-component aspartic polyurea coating A and B components and the heating temperature of the spraying machine are set according to the actual requirement of the coating, and the matters needing attention and spraying points of the machine spraying are executed according to the conventional two-component spraying polyurea construction technology.

[0098] 3. The wet film thickness of the wet film on the front surface of the steel plate is controlled to be 150-180 μm during spraying to ensure that the dry film thickness is 120-150 μm.

[0099] 5. The wet film is cured into a film at room temperature after being left to stand for 1-2 hours or is cured into a film by being baked in an 80°C oven for 30 minutes.

[0100] Advantages

[0101] 1. The present application discloses an HBPSi-AP, which is characterized in that a Si-O-Si skeleton of polysiloxane is constructed into a hyperbranched structure with a three-dimensional space, and an aspartic acid ester end-capping group is introduced into a traditional aspartic polyurea polymer structure. Thus, the adhesion of the aspartic acid ester polyurea coating to a metal surface as a thick paste type "floor combined" coating is significantly improved, and the salt spray resistance of the coating scratch is surprisingly improved. The main mechanism is as follows: a. The hyperbranched space structure has a large number of reactive sites, which makes the curing reaction balance uniform and has an "isotropic" effect, thereby avoiding the defect that linear structure coating film is prone to shrinkage due to large internal stress, thus overcoming the defect that the aspartic polyurea coating, especially the solvent-free aspartic polyurea coating, affects the adhesion to the metal surface due to excessive shrinkage.

[0102] b. The hyperbranched space structure avoids the phenomenon of intramolecular entanglement of linear structure, so that the resin has low viscosity and good flowability, which is beneficial to improve the wettability of the aspartic polyurea coating, especially the solvent-free aspartic polyurea coating, to the surface, thereby improving the adhesion.

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

[0104] d. The aspartic acid ester active group end-capping introduces the hyperbranched structure of polysiloxane into the polyurea polymer structure, improves the compatibility of the system, and also maintains the excellent physical and chemical properties of the polyurea coating and the fast curing process performance.

[0105] 2. The present application discloses an HBPSi-AP, which is characterized in that γ-aminopropyl triethoxysilane (coupling agent KH550) is first aminated, 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 and practical, and can be used for industrial production. BRIEF DESCRIPTION OF DRAWINGS

[0106] Figure 1Diethyl maleate infrared spectrum

[0107] Figure 2 KH550 infrared spectrum

[0108] Figure 3 Aspartate-terminated n-propyl triethoxysilane infrared spectrum

[0109] Figure 4 Aspartate-terminated hyperbranched polysiloxane (HBPSi-AP) infrared spectrum. DETAILED DESCRIPTION

[0110] Table 1 Main raw materials used in examples

[0111]

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

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

[0114] 2 Automatic potentiometric titrator AT-1 (Shanghai Hugong Scientific Instruments Co., Ltd.)

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

[0116] 4 Coating thickness meter MC-3000S-FN (Jining KeDian Instrument Co., Ltd.)

[0117] 5 Digital display hydraulic drawing type adhesion tester PosiTest AT-A (DeFesko, USA)

[0118] 6 Neutral salt spray test chamber LRHS-412-RY (Shanghai Linpian Instrument Co., Ltd.)

[0119] Example 1 Preparation of HBPSi-AP

[0120] First step: Preparation of aspartate-terminated n-propyl triethoxysilane

[0121] In a 500 mL four-necked glass flask equipped with an electric stirrer, thermometer, reflux condenser, constant-pressure dropping funnel, and nitrogen delivery tube, 221 g of γ-aminopropyltriethoxysilane (KH550) was added, followed by purging with nitrogen to remove oxygen from the flask. The stirrer was started and the temperature was gradually increased to 45-50 °C. 173 g of diethyl maleate was then added dropwise through the constant-pressure dropping funnel, controlling the heat release over 30-40 minutes to ensure the temperature did not exceed 60 °C. The reaction was then continued for 12 hours under nitrogen protection at 60 ± 2 °C. Finally, the temperature was raised to 80 °C and a vacuum was applied for 30 minutes to remove unreacted small molecules. After cooling, aspartic acid ester-terminated n-propyltriethoxysilane was obtained (see...). Figure 3 (Infrared spectrum).

[0122] contrast Figure 1 The infrared spectrum of diethyl maleate, by Figure 3 As can be seen, the infrared absorption spectrum is at 1644 cm⁻¹ -1 The absorption peak at that location has disappeared, compared to Figure 2 The infrared spectrum of KH550, by Figure 3 See, at 3400-3500cm -1 The primary amine bimodal peak at 3338 cm⁻¹ changes to a peak at 3338 cm⁻¹. -1 The singlet at 1079 cm⁻¹ indicates that the double bond of diethyl maleate has successfully undergone a Michael addition reaction with the primary amine of KH550. -1 The absorption peak at that point is due to the bending vibration of Si-OC.

[0123] Step 2: Preparation of HBPSi-AP

[0124] In a 500 mL three-necked glass flask equipped with an electric stirrer, thermometer, reflux condenser, and nitrogen delivery tube, 197 g of the above-mentioned aspartic acid ester-terminated n-propyltriethoxysilane and 197 g of ethanol were weighed out and stirred until they dissolved. Nitrogen gas was introduced to purge oxygen from the reaction flask, and then 11.7 g of deionized water was added. The temperature was raised to 60 °C, and the reaction was refluxed under nitrogen protection for 4 h. After the reaction was completed, small molecules such as ethanol and water were removed by rotary evaporation, and the resulting colorless viscous oily substance was HBPSi-AP (see [link to product description]). Figure 2 The infrared spectrum of the product was analyzed, and the average amino equivalent of the product was determined to be 185 by potentiometric titration.

[0125] Depend on Figure 4 It can be seen that, compared to Figure 3 The infrared absorption spectrum is in the range of 1072-1172 cm⁻¹ -1 There is a significant shift in the absorption peak at 3453 cm⁻¹, which is likely due to the formation of Si-O-Si groups. On the other hand, at 3453 cm⁻¹... -1There are obvious absorption peaks in the vicinity, which is the stretching vibration of O-H. The above two changes show that Si-O-C hydrolysis and condensation occur, and hyperbranched polysiloxane is successfully synthesized.

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

[0127] Preparation of high solid solvent-based two-component coating based on HBPSi-AP and its control example, according to the proportions listed in Table 2 resin component (A component) formula and Table 3 curing agent component (B component) formula. Each component in the table is by weight.

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

[0129] Serial No. Ingredient 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 Environment-friendly solvent 6 6 6 6 6 6 6 Dispersant 3 3 3 3 3 3 7 Titanium dioxide 9 9 9 9 9 9 8 Functional filler 25 25 25 25 25 25 9 Water removal agent 4 4 4 4 4 4 10 Talc 3 3 3 3 3 3 11 Barium sulfate 9 9 9 9 9 9 12 Environment-friendly solvent 2 2 2 2 2 2 13 Leveling agent 0.8 0.8 0.8 0.8 0.8 0.8 14 Antioxidant 1.5 1.5 1.5 1.5 1.5 1.5 15 Anti-ultraviolet agent 1 1 1 1 1 1 16 Black paste 0.7 0.7 0.7 0.7 0.7 0.7 17 Total weight 100 100 100 100 100 100 18 Average equivalent weight 592 592 591 559 797 816

[0130] Table 3 High solid solvent-based curing agent component (B component) formula

[0131]

[0132]

[0133] Wherein:

[0134] Preparation of G1-G4 and comparative examples G5-G6 components in A component

[0135] Preparation method

[0136] 1 According to the G1 formula in Table 2, first put the raw materials with serial numbers 1-6 into the container in turn, and mix thoroughly.

[0137] 2 Under stirring, then put the raw materials with serial numbers 7-11 into the container in turn, and then increase the speed to 2000 rpm for high-speed dispersion for 30 min.

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

[0139] 4 Under stirring, put the raw materials with serial numbers 12-15 into the container in turn, then put the color paste raw material with serial number 16 into the container for accurate color matching, and then high-speed (2000 rpm) dispersion for 30 min, to obtain the G1 component in A component.

[0140] G2-G4 and comparative examples G5-G6 components in A component are prepared according to the above steps respectively.

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

[0142] Preparation method

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

[0144] B components GH2-GH3 were prepared according to the above steps, respectively.

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

[0146] Preparation method

[0147] 1. The appropriate amount of A and B components were weighed according to the formulation of GF1 in Table 4, then mixed and stirred uniformly. Finally, a small amount of environmentally friendly solvent was used to adjust the viscosity of the mixture according to the usage habit.

[0148] 2. The mixed paint with adjusted viscosity was loaded into the air gun tank for spraying. The air pressure and nozzle size required for the air gun were set and adjusted according to the experience and habit commonly used in the field of coating technology.

[0149] 3. The wet film thickness on the front surface of the steel plate was controlled to reach 150-180 μm during spraying to ensure the dry film thickness of 120-150 μm.

[0150] 4. After flash drying for 10 minutes, the wet film was placed at room temperature for 2-4 hours to cure into a film, or placed in an 80°C oven for 30 minutes to cure into a film, i.e. GF1 paint film test plate.

[0151] 5. After 7 days of room temperature storage, the adhesion test and scratch salt spray test were performed.

[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] Preparation and testing of paint films of high solid solvent-based two-component coating based on HBPSi-AP and its control examples were performed according to the proportions listed in the paint preparation formulation of Table 4. Each component in the table is by weight.

[0154] Table 4 Paint preparation formulation of solvent-based two-component coating based on HBPSi-AP and its control examples

[0155]

[0156]

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

[0158] Substrate preparation, take enough number of carbon steel plate with specification 200x150x3mm, polish or sandblast or shot blasting on its front surface until the surface is bare metal color, then blow off the surface dust, and wait for use.

[0159] Tensile adhesion test, according to GB / T 5210-2006.

[0160] Scratch neutral salt spray test, first according to GB / T 30786-2014 to scratch the mark on the metal plate coating, then according to GB / T 10125-2012 to perform scratch salt spray test.

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

[0162] Preparation and test of solvent-free two-component coating based on HBPSi-AP and its control example, according to the proportion listed in Table 4 resin component (A component) formula and the proportion listed in Table 6 curing agent component (B component) formula. Each component in the table is by weight.

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

[0164] Serial No. Ingredient 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 Dispersant 4 4 4 4 4 4 7 Titanium dioxide 9 9 9 9 9 9 8 Functional filler 25 25 25 25 25 25 9 Water removal agent 4 4 4 4 4 4 10 Talc 3 3 3 3 3 3 11 Barium sulfate 11 11 11 11 11 11 12 Organic clay 1 1 1 1 1 1 13 Leveling agent 0.8 0.8 0.8 0.8 0.8 0.8 14 Antioxidant 1.5 1.5 1.5 1.5 1.5 1.5 15 Anti-ultraviolet agent 1 1 1 1 1 1 16 Black paste 0.7 0.7 0.7 0.7 0.7 0.7 17 Total weight 100 100 100 100 100 100 18 Average equivalent weight 592 592 591 559 797 816

[0165] Table 6 Solvent-free curing agent component (B component) formula

[0166]

[0167]

[0168] Wherein:

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

[0170] 1 According to the W1 formula in Table 5, first put the raw materials with serial numbers 1-6 into the container in turn, and fully stir evenly.

[0171] 2 Under stirring, then put the raw materials with serial numbers 7-12 into the container in turn, and then increase the speed to 2000rpm for high-speed dispersion for 30min.

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

[0173] 4 Under stirring, put the raw materials with serial numbers 13-15 into the container in turn, then put the color paste raw material with serial number 16 into the container for accurate color matching, and then high-speed (2000rpm) dispersion for 30min, to obtain B component W1.

[0174] W2-W4 and Comparative Examples W5-W6 were prepared according to the procedure described above.

[0175] Preparation of B component WH1

[0176] According to the formulation of WH1 in Table 6, the raw materials of each serial number were mixed uniformly in a suitable container, and the A component WH1 was obtained.

[0177] WH2-WH3 were prepared according to the above method.

[0178] Preparation and testing of WF1-WF4 and Comparative Examples WF5-WF6 paint films of solvent-free two-component coatings based on HBPSi-AP

[0179] Preparation method

[0180] 1. Using a variable ratio two-component low-pressure polyurea spraying machine, the mixing ratio of A (resin component) and B (curing agent component) was adjusted according to the volume mixing ratio in the formulation WF1 in Table 7, and the heating temperature of the spraying machine was set to 55°C for A component and 45°C for B component. The rest of the spraying machine operation essentials and precautions were performed according to the requirements of the spraying machine and the conventional two-component spraying polyurea construction technology.

[0181] 2. The wet film thickness on the front surface of the steel plate was controlled to be 150-180 μm during spraying to ensure that the dry film thickness was 120-150 μm.

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

[0183] 4. After being placed at room temperature for 7 days, testing was performed.

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

[0185] Preparation and testing of paint films of solvent-free two-component coatings based on HBPSi-AP and their comparative examples were performed according to the proportions listed in the paint preparation formulation in Table 7. Each component in the table is by weight.

[0186] Table 7 Paint preparation formulation of solvent-free two-component coatings based on HBPSi-AP and their comparative examples

[0187]

[0188]

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

[0190] Substrate preparation, take enough number of carbon steel plate with specification 200x150x3mm, polish or sandblast or shot blasting treatment on its front surface until the surface bare metal original color, then blow off the surface dust, ready for use.

[0191] Pull-off adhesion test, according to GB / T 5210-2006.

[0192] Scratch neutral salt spray test, first according to GB / T 30786-2014 to mark on the metal plate coating, then according to GB / T 10125-2012 to perform scratch salt spray test.

[0193] Summary:

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

[0195] Table 8 Example Test Results

[0196]

[0197] From Table 8, it can be seen that the two-component polyurea coating based on HBPSi-AP involved in the present patent, whether it is high solid solvent-based paint or solvent-free paint, the thickness of the first coating can reach more than 120μm. At the same time, as a thick paste type "one coat" coating, the adhesion to the metal surface is more than 12mPa, which is significantly improved compared with the control example. And their coating has passed the scratch neutral salt spray test, the high solid solvent-based coating and the solvent-free coating have exceeded 700 hours and 800 hours respectively, which is surprisingly improved compared with the control example.

Claims

1. A two-component asparto-polyurea coating based on HBPSi-AP, characterized in that, It comprises high solid content solvent type two-component aspartic polyurea coating, which contains component A and component B; The A component, i.e. the resin component, consists of the following weight percentage components based on the total weight of the A component: (1) at least 25% by weight of HBPSi-AP; (2) at most 10% by weight of aspartic ester resin; (3) at most 55% by weight of pigments and fillers and coating additives; (4) at most 10% by weight of environmentally friendly solvent; The B component, i.e. the curing agent component, consists of the following weight percentage components based on the total weight of the B component: (1) at least 90% by weight of isocyanate curing agent; (2) at most 10% by weight of environmentally friendly solvent; The structure of HBPSi-AP is shown in formula 1: wherein: Formula 1; The HBPSi-AP is prepared by the following steps: A. Michael addition reaction of γ-aminopropyl triethoxysilane with diethyl maleate to obtain n-propyl triethoxysilane capped with aspartic ester, and the reaction formula is shown in formula 2: Formula 2; B. The n-propyl triethoxysilane capped with aspartic ester is further subjected to hydrolysis and condensation reaction to obtain HBPSi-AP resin, and the reaction process is shown in formula 3: wherein: Formula 3; The weight mixing ratio of the A and B components is 2:1-2.5:1, the construction solid content is 80-85%, and the mixing and sufficient stirring are uniform to obtain the two-component aspartic polyurea coating based on HBPSi-AP.

2. The two-component aspartic polyurea coating based on HBPSi-AP according to claim 1, wherein In the A component: the aspartic ester resin includes Covestrode's Desmophen NH1420, NH1520, NH1220 and NH2850, which are 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 are used alone or mixed with each other in any proportion, and the total amount is 15-30% of the total weight of the A component; the modified pigments and fillers include titanium dioxide, calcium carbonate, barium sulfate, talc, carbon black and iron red, which are used alone or mixed with each other in any proportion, and the total amount is 15-30% of the total weight of the A component; The coating additives include dispersants, leveling agents, defoamers, thixotropic agents, water repellents, antioxidants and ultraviolet light resistant agents, and the total amount is 3-10% of the total weight of the A component; The environmentally friendly solvent includes propylene glycol methyl ether acetate, a mixture of succinic acid dimethyl ester, glutaric acid dimethyl ester and adipic acid dimethyl ester, 3-ethoxypropyl acetate and butyl acetate, which are used alone or mixed with each other in any proportion; The A component is prepared by the following steps: (1) weigh the HBPSi-AP and the appropriate aspartic ester resin into a suitable container and stir to mix uniformly; (2) add an appropriate amount of environmentally friendly solvent, dispersant and defoamer, and stir to mix uniformly; (3) under stirring, add the pigments and fillers and other coating additives except leveling agents, antioxidants and ultraviolet light resistant agents in sequence, and then disperse at high speed of 2000 rpm for 30 min; (4) The above mixture slurry is put into a sand mill for grinding until the fineness is ≤35 μm; (5) Under stirring, the leveling agent, antioxidant, ultraviolet resistant agent and the remaining environmentally friendly solvent are added into the above ground slurry, and the color is adjusted with a suitable color paste, and then dispersed at a high speed of 2000 rpm for 30 min; (6) Packaging, the finished product is obtained; In the B component: 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, which are used alone or mixed with each other in any proportion; The environmentally friendly solvent in the B component includes propylene glycol methyl ether acetate PMA, dimethyl succinate, dimethyl glutarate and a mixture of dimethyl adipate DBE, 3-ethoxypropyl acetate EEP and butyl acetate BAC, which are used alone or mixed with each other in any proportion; The B component is prepared by uniformly mixing the isocyanate curing agent with the environmentally friendly solvent, and then packaging to obtain the finished product.

3. A two-component asparto-polyurea coating based on HBPSi-AP, characterized in that, It includes a solvent-free two-component aspartic polyurea coating, which contains an A component and a B component; The A component, i.e. the resin component, is composed of the following weight percentage components based on the total weight of the A component: (1) at least 25% by weight of HBPSi-AP; (2) at most 15% by weight of aspartic ester resin; (3) at most 55% by weight of pigments and fillers and coating additives; (4) at most 5% by weight of active diluent; The B component, i.e. the curing agent component, is composed of a solvent-free isocyanate curing agent; The structure of HBPSi-AP is shown in Formula 1: wherein: Formula 1; The HBPSi-AP is prepared by the following steps: A. Michael addition reaction of γ-aminopropyl triethoxysilane with diethyl maleate to obtain n-propyl triethoxysilane capped with aspartic ester, and the reaction formula is shown in Formula 2: Formula 2; B. The n-propyl triethoxysilane capped with aspartic ester is further subjected to hydrolysis and condensation reaction to obtain HBPSi-AP resin, and the reaction process is shown in Formula 3: wherein: Formula 3; The weight mixing ratio of the A and B components is 2.5:1-2.7:1, and the construction solid content is 98-100%, and the mixing and sufficient stirring are uniform to obtain the two-component aspartic polyurea coating based on HBPSi-AP.

4. The two-component aspartic polyurea coating based on HBPSi-AP according to claim 3, wherein: In the A component: the aspartic ester resin includes Desmophen NH1420, NH1520, NH1220 and NH2850 of Covestrode, which are used alone or mixed with each other in any proportion; In the A component: the aspartic ester resin includes Desmophen NH1420, NH1520, NH1220 and NH2850 of Covestrode, which are used alone or mixed with each other in any proportion; The color filler includes functional filler and modified color filler, wherein the functional filler includes zinc phosphate, zinc phosphomolybdate, zinc phosphate aluminum and mica powder, which are used alone or mixed with each other in any proportion, and the total amount is 15-30% of the total weight of the A component; the modified color filler includes titanium white, calcium carbonate, barium sulfate, talc, carbon black and iron red, which are used alone or mixed with each other in any proportion, and the total amount is 15-30% of the total weight of the A component; The coating aid includes dispersant, leveling agent, defoaming agent, thixotropic agent, water removing agent, antioxidant and ultraviolet resistant agent, and the total amount is 3-10% of the total weight of the A component; The active diluent includes propylene carbonate PC, γ-butyrolactone, acetyl tributyl citrate ATBC, which can be used alone or mixed with each other in any proportion; The A component is prepared by the following steps: (1) Measure the HBPSi-AP and the appropriate aspartate resin into a suitable container and stir to mix uniformly; (2) Add an appropriate amount of active diluent and dispersant, defoaming agent, and stir to mix uniformly; (3) Under stirring, add the color filler and other coating aids except leveling agent, antioxidant and ultraviolet resistant agent, and then disperse at high speed 1500 rpm for 30 min; (4) Put the above mixture into a sand mill for grinding until the fineness is ≤35 μm; (5) Under stirring, add the leveling agent, antioxidant, ultraviolet resistant agent and the remaining active diluent to the above ground slurry, and then disperse at high speed 1500 rpm for 30 min; (6) Package, and the finished product is obtained; In the B component: the isocyanate curing agent is aliphatic isocyanate curing agent or aromatic isocyanate curing agent, including hexamethylene diisocyanate HDI and its trimer, HDI biuret, isophorone diisocyanate IPDI and its trimer, dicyclohexyl methane diisocyanate HMDI, diphenyl methane diisocyanate MDI, liquefied MDI, toluene diisocyanate TDI, TDI dimer, TDI trimer and TDI modified prepolymer, which are used alone or mixed with each other in any proportion; The B component directly selects a suitable curing agent, and then the finished product is obtained by packaging.

5. The HBPSi-AP based two-component aspartic polyurea coating according to any one of claims 1 to 4, characterized in that The amino equivalent and isocyanate equivalent in the A and B components are calculated to make 〔NH〕 / 〔NCO〕=1:1.05-1:1.1, the A and B components are weighed, then mixed and stirred uniformly to obtain the HBPSi-AP based two-component asparto polyurea coating.

6. The HBPSi-AP based two-component aspartic polyurea coating according to any one of claims 1 to 4, characterized in that The HBPSi-AP is prepared by the following steps, A. γ-aminopropyl triethoxysilane and diethyl maleate with a molar ratio of 1:1.0-1:1.005 are first subjected to Michael addition reaction by dropping diethyl maleate into γ-aminopropyl triethoxysilane under nitrogen protection and at 45-50℃, and the dropping reaction temperature is controlled not to exceed 65℃; after the dropping is completed, the reaction is kept at constant temperature 60±2℃ for 8-20 hours; after the reaction is completed, it is cooled to below 40℃, and the normal propyl triethoxysilane capped with aspartate is obtained; B, first dissolve the aspartate-terminated n-propyl triethoxysilane in ethanol solvent with a weight ratio of 1:1, then introduce nitrogen to remove oxygen, and add deionized water under stirring; the amount of deionized water added is in a molar ratio of 1:1-1.3:1 with the aspartate-terminated n-propyl triethoxysilane; then reflux at 60°C for 4 hours; after the reaction is completed, remove ethanol, water and other small molecules by vacuum to obtain a colorless low-viscosity oil product, which is HBPSi-AP.

7. Use of the two-component aspartic polyurea coating based on HBPSi-AP according to any one of claims 1-6 as a heavy-duty anticorrosive coating.

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