A high-performance solvent-free blade wear-resistant self-healing topcoat and its preparation method

Abstract

This invention discloses a high-performance solvent-free self-healing wear-resistant topcoat for wind turbine blades and its preparation method, belonging to the field of wind power generation technology. The high-performance solvent-free self-healing wear-resistant topcoat comprises component A and component B. Component A contains IPDI trimer, POSS-isocyanate nano-hybrid, urea-based supramolecular thickener, and latent organic bismuth catalyst. Component B contains modified polyaspartic acid ester, 3-aminopropyltrimethoxysilane, and fluorinated segment polyaspartic acid ester. The high-performance solvent-free self-healing wear-resistant topcoat of this invention constructs a rigid and tough cross-linked network by introducing POSS-isocyanate nano-hybrid and modified polyaspartic acid ester, solving the interfacial incompatibility problem of traditional physically blended coatings. Simultaneously, it endows the coating with excellent wear resistance, strong adhesion, and micro-scratch self-healing ability. This topcoat is a solvent-free system, environmentally friendly, and has good application performance, effectively extending blade life.

Description

Technical Field

[0001] This invention relates to the field of wind power generation technology, specifically to a high-performance solvent-free blade wear-resistant self-healing topcoat and its preparation method. Background Technology

[0002] Against the backdrop of a global energy structure transition towards cleaner and lower-carbon energy sources, wind power, as one of the renewable energy sources with the greatest potential for large-scale development, is increasingly prominent. The trend towards larger, lighter, and more efficient wind turbines is currently a core trend in technological development. Among these, the wind turbine blade, as a key component for capturing wind energy, directly determines the overall power generation efficiency and operational economy of the wind turbine. During operation, the leading edge of the blade collides at high speeds (80-100 m / s) with hard particles in the atmosphere, such as raindrops, hail, dust, and insects. This causes severe erosion, wear, and peeling of the surface coating and composite material matrix—a phenomenon known as "leading edge erosion." Leading edge erosion not only damages the aerodynamic shape of the blade and significantly reduces wind energy capture efficiency, but also accelerates fatigue damage to the matrix material and can even lead to structural safety risks, resulting in high operation and maintenance costs.

[0003] However, existing blade leading edge protection technologies still have many shortcomings and cannot fully meet the requirements of large wind turbines for long-term stable operation in harsh environments. Firstly, while traditional solvent-based polyurethane or epoxy coatings are technically mature, their inherent defects are becoming increasingly prominent: they contain large amounts of volatile organic compounds (VOCs), causing environmental pollution and harming the health of construction workers during application and curing; the evaporation of solvents prolongs the application cycle and easily forms defects such as micropores in the coating, affecting its density and protective performance. Secondly, existing solvent-free or high-solids coatings developed to avoid solvent problems also face their own technical challenges. For example, many solvent-free systems, such as traditional polyurea, have extremely high reactivity and a very short pot life. They must rely on expensive and complex two-component high-temperature and high-pressure spraying equipment, which has stringent requirements for the construction environment and operating techniques, increasing the difficulty and cost of on-site maintenance. More importantly, in pursuit of high hardness and wear resistance, existing protective coatings often sacrifice the toughness and impact resistance of the coating, making it brittle and cracked under blade deformation or high-speed water droplet impact. Conversely, overemphasizing flexibility can lead to insufficient erosion and scratch resistance of the coating.

[0004] Existing technology CN117050626B discloses a polyurea-ceramic composite coating, which improves the coating's resistance to rain erosion by physically incorporating high-hardness ceramic particles into polyaspartic acid ester polyurea resin. This invention utilizes hydrophilic polyetheramine monomers to form a water film on the system surface to buffer raindrop impact. While this approach has some innovation, its inherent limitations are also quite obvious. First, this technology is essentially a physical blending process. There is a natural interfacial incompatibility between the inorganic ceramic filler and the organic polyurea matrix. The ceramic particles become stress concentration points in the coating, easily detaching from the matrix under external impact, which can accelerate the initiation and propagation of microcracks, potentially leading to a decrease in the coating's toughness and fatigue resistance instead of an increase. Secondly, the practical effectiveness of the proposed "water film buffering" theory under high-speed impact scenarios is questionable. The collision velocity between the blade leading edge and raindrops is extremely high, and the impact pressure is enormous. Whether a micron-sized, dynamically formed, instantaneous water film can provide effective energy absorption and buffering lacks sufficient theoretical and experimental support, and its effect may be far less than the material's inherent damping and toughness. Thirdly, the addition of a large amount of high-density solid ceramic particles will significantly increase the viscosity and density of the coating. This not only poses a greater challenge to the spraying application of solvent-free systems but may also increase the overall weight and rotational inertia of the blades, potentially negatively impacting the aerodynamic performance and structural load of the wind turbine. Therefore, this solution still has significant limitations in addressing the balance between rigidity and toughness, interfacial compatibility, and construction applicability. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the present invention discloses a high-performance solvent-free blade wear-resistant self-healing topcoat and its preparation method. By adding POSS-isocyanate nano-hybrid and modified polyaspartic acid ester to the topcoat, a high-performance wind turbine blade topcoat with high wear resistance, high toughness, strong adhesion, self-healing ability and low surface friction is prepared.

[0006] This invention protects a high-performance solvent-free blade wear-resistant self-healing topcoat, comprising component A and component B;

[0007] Component A contains IPDI trimer, POSS-isocyanate nano-hybrid, urea-based supramolecular thickener, and latent organic bismuth catalyst.

[0008] Component B contains modified polyaspartic acid ester, 3-aminopropyltrimethoxysilane, and fluorinated segment polyaspartic acid ester.

[0009] Preferably, the mass ratio of component A to component B is 110~120:100.

[0010] More preferably, the mass ratio of component A to component B is 114~117:100.

[0011] Preferably, the POSS-isocyanate nanohybrid is prepared by the following method: octa(3-hydroxypropyl)silsesquioxane is dissolved in anhydrous toluene, dibutyltin dilaurate catalyst is added, the mixture is heated to 70°C, PDI monomer is added dropwise while controlling the temperature not to exceed 80°C, and after the addition is complete, the mixture is reacted at 80°C for 4 hours, and toluene is removed by vacuum distillation to obtain the POSS-isocyanate nanohybrid.

[0012] Preferably, the modified polyaspartic acid ester is prepared by the following method: adding diethyl maleate to a reaction vessel equipped with a mechanical stirrer, adding 2-methyl-1,5-pentanediamine and cystamine, heating to 50°C under nitrogen protection, controlling the dropping rate to keep the reaction temperature below 60°C, and maintaining the reaction at 60°C for 24 hours after the dropping is completed to obtain the modified polyaspartic acid ester.

[0013] Preferably, the mass ratio of the IPDI trimer, POSS-isocyanate nanohybrid, urea-based supramolecular thickener, and latent organic bismuth catalyst is 100:15~20:0.3~0.5:0.2~0.3.

[0014] Preferably, the weight ratio of the modified polyaspartic ester, 3-aminopropyltrimethoxysilane and fluorinated segment polyaspartic ester is 95~100:3~5:0.5.

[0015] Preferably, the molar ratio of the octa(3-hydroxypropyl)silsesquioxane to the PDI monomer is 1:8~10, and the weight of the dibutyltin dilaurate catalyst is 0.05% of the total weight of the octa(3-hydroxypropyl)silsesquioxane and the PDI monomer.

[0016] Preferably, the molar ratio of diethyl maleate, 2-methyl-1,5-pentanediamine and cystamine is 2:0.9~1:0.05~0.07.

[0017] This invention also claims protection for a method for preparing the above-mentioned high-performance solvent-free blade wear-resistant self-healing topcoat, comprising the following steps:

[0018] Step 1, Preparation of Component A: Add IPDI trimer to a dry mixing vessel, add POSS-isocyanate nano-hybrid and stir for 30 minutes, add urea-based supramolecular thickener and stir until a uniform gel is formed, add latent organic bismuth catalyst and stir at 100-150 rpm for 10 minutes, then seal and package to obtain Component A.

[0019] Step 2, Preparation of Component B: Add the modified polyaspartic acid ester to a dry mixing tank, add 3-aminopropyltrimethoxysilane and stir until homogeneous, add the fluorinated polyaspartic acid ester and continue stirring until homogeneous, then seal and package to obtain Component B.

[0020] Step 3, Spraying and Curing: Grind the leading edge of the blade substrate to a roughness of Ra 3~5μm and clean and dry it with anhydrous ethanol. Mix components A and B using a two-component high-pressure airless spraying device, heat to 60℃, and spray onto the substrate surface at a spraying pressure of 20~25MPa. The single wet film thickness is 500~800μm. Allow it to cure naturally for 24 hours at an ambient temperature of 10~35℃ and a relative humidity of 50%~80% until it is surface dry. The performance is complete after 7 days, resulting in a high-performance solvent-free blade wear-resistant self-healing topcoat.

[0021] The present invention has the following beneficial effects:

[0022] (1) This invention discloses a high-performance solvent-free blade wear-resistant self-healing topcoat. By introducing POSS-isocyanate nano-hybrid and modified polyaspartic acid ester, a cross-linked network with both rigidity and toughness is constructed, which solves the interfacial incompatibility problem of traditional physical blend coatings. At the same time, it endows the coating with excellent wear resistance, strong adhesion and micro-scratch self-healing ability. The topcoat is a solvent-free system, which is environmentally friendly and has good construction performance, and can effectively extend the service life of the blade.

[0023] (2) This invention discloses a high-performance solvent-free blade wear-resistant self-healing topcoat. The curing stage after spraying the blade can be divided into three stages. In the first stage, due to the shear thinning effect of the thickener in the topcoat, the topcoat will flow and level on the substrate surface. Under the action of 3-aminopropyltrimethoxysilane, the topcoat and the substrate are covalently bonded, providing strong adhesion. In the second stage, the secondary amine groups on the surface of the modified polyaspartic acid ester, acting as basic substances, gradually unwind their complex structure upon contact with the latent organobismuth catalyst, releasing highly active organobismuth catalytic centers. Once activated, the catalyst rapidly accelerates the polyurea addition reaction between the isocyanate reactants in component A and the amine reactants in component B. At this point, with the formation of the polyurea network, the polarity of the system increases rapidly. The fluorinated segments of the polyaspartic acid ester have extremely low surface energy and are thermodynamically incompatible with the polar polyurea network. To minimize the free energy of the entire system, these fluorinated molecules spontaneously migrate from the interior of the system to the interface between the paint film and the air, forming a fluorine-rich surface layer. The accelerated polyurea reaction allows the paint film to dry quickly, preventing dust contamination. The fluorine-rich surface layer provides the first line of defense for the paint film, reducing the tangential impact force of raindrops and sand particles by lowering the coefficient of friction, directly reducing the burden on the underlying paint film, and improving the aerodynamic cleanliness of the blades. In the third stage, during the continuous growth and cross-linking of the polyurea network, two parts with vastly different chemical and physical properties begin to undergo microscopic phase separation: the POSS-isocyanate nanohybrid, as a rigid inorganic center, forms a hard phase with extremely high polyurea density around it, giving the paint film high wear resistance; the IPDI trimer and modified polyaspartic acid ester form a relatively flexible polyurea network, constituting a soft phase, giving the paint film impact resistance. The two are connected by covalent bonds, forming an interpenetrating network structure. When the paint film is impacted, the energy is absorbed and dissipated by the flexible soft phase. When the energy is sufficient to generate microcracks, the stress at the crack tip will preferentially break the disulfide bonds with lower energy. Under light, the sulfur free radicals generated by the breakage can undergo disulfide bond exchange reactions, recombine with neighboring disulfide bonds or another sulfur free radical, thereby healing the crack and giving the paint film self-healing ability, greatly extending the service life of the blade. Attached Figure Description

[0024] Figure 1 This is a schematic flowchart of the preparation method of the high-performance solvent-free blade wear-resistant self-healing topcoat of the present invention. Detailed Implementation

[0025] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0026] The urea-based supramolecular thickener used in this application embodiment is a urea-formaldehyde resin thickener, sourced from Guangdong Zhongke Hongtai Materials Co., Ltd., model number C-140; the latent organobismuth catalyst used is organobismuth catalyst MB20, sourced from Shanghai Xindian Chemical Materials Co., Ltd.; the IPDI trimer is sourced from Jining Hongming Chemical Reagent Co., Ltd., model number 02.

[0027] The chemical structural formula of IPDI trimer is as follows:

[0028]

[0029] The chemical structural formula of the latent organobismuth catalyst is as follows:

[0030]

[0031] This application discloses a high-performance solvent-free blade wear-resistant self-healing topcoat, comprising component A and component B;

[0032] Component A contains IPDI trimer, POSS-isocyanate nano-hybrid, urea-based supramolecular thickener, and latent organic bismuth catalyst.

[0033] It is understood that in component A of this application embodiment, IPDI trimer serves as the main resin, providing flexibility and weather resistance; POSS-isocyanate nano-hybrid serves as the reinforcing phase, improving the degree of crosslinking polymerization of the topcoat; urea-based supramolecular thickener serves as a rheology control agent, used to prevent the topcoat from sagging; and latent organic bismuth catalyst is used to catalyze and control the curing process after subsequent combination with component B.

[0034] Component B contains modified polyaspartic acid ester, 3-aminopropyltrimethoxysilane, and fluorinated segment polyaspartic acid ester.

[0035] It is understood that in component B of the embodiments of this application, modified polyaspartic acid ester serves as the main curing agent, providing the topcoat with self-healing function and toughness; 3-aminopropyltrimethoxysilane serves as an interfacial coupling agent, covalently bonding with the substrate; and fluorinated segment polyaspartic acid ester serves as a surface modifier, driven by the low surface energy of the fluorinated segments, spontaneously forming a low-friction enrichment layer during the topcoat spraying and curing process, thereby enhancing the topcoat's impact resistance and stain resistance.

[0036] In some embodiments, the mass ratio of component A to component B is 110~120:100.

[0037] In some embodiments, the mass ratio of component A to component B is 114~117:100.

[0038] In some embodiments, the POSS-isocyanate nanohybrid is prepared by the following method: octa(3-hydroxypropyl)silsesquioxane is dissolved in anhydrous toluene, dibutyltin dilaurate catalyst is added, the mixture is heated to 70°C, PDI monomer is added dropwise while controlling the temperature not to exceed 80°C, and after the addition is complete, the mixture is reacted at 80°C for 4 hours. Toluene is removed by vacuum distillation to obtain the POSS-isocyanate nanohybrid.

[0039] In this process, octa(3-hydroxypropyl)silsesquioxane and PDI monomer act as reactants, while dibutyltin dilaurate acts as a catalyst. Dibutyltin dilaurate forms an unstable intermediate complex with the hydroxyl group of the hydroxypropyl group on the surface of octa(3-hydroxypropyl)silsesquioxane or the isocyanate group of the PDI monomer, thereby increasing the reactivity. The reaction type is a nucleophilic addition reaction. The oxygen atom on the hydroxyl group of octa(3-hydroxypropyl)silsesquioxane, which has a lone pair of electrons, acts as a nucleophile. The PDI molecule... In the isocyanate group on PDI, the carbon atom is electron-deficient due to the connection of highly electronegative nitrogen and oxygen, resulting in an empty orbital. As an electrophile, the oxygen atom on the hydroxyl group of octa(3-hydroxypropyl)silsesquioxane attacks the electron-deficient carbon atom of the -NCO group on PDI. After the attack, the electron cloud rearranges, and the hydrogen atom on the hydroxyl group transfers to the nitrogen atom of the -NCO group, ultimately forming a stable carbamate bond -OC(=O)-NH-. The reaction can be simplified as follows:

[0040] POSS-(CH2)3-OH]8+8[OCN-PDI-NCO]→POSS-{(CH2)3-OC(=O)-NH-[IPDI]-NCO}8

[0041] It is understood that in the embodiments of this application, the POSS-isocyanate nanohybrid has a rigid inorganic core and eight flexible isocyanate arms with reactive ends, which can form a highly uniform and high-density cross-linked network during curing. During the reaction, the hydroxyl groups of octa(3-hydroxypropyl)silsesquioxane undergo nucleophilic addition to the isocyanate groups of the PDI monomer to form urethane bonds, connecting the PDI segments to each vertex of the octa(3-hydroxypropyl)silsesquioxane. Because the PDI monomer added in the embodiments of this application is in excess, the reaction is ensured to be complete while the -NCO groups are retained at the end of the product, which can react with the substrate or moisture in the air to enhance the cross-linking density and adhesion of the final topcoat.

[0042] In some embodiments, the modified polyaspartic acid ester is prepared by the following method: adding diethyl maleate to a reaction vessel equipped with a mechanical stirrer, adding 2-methyl-1,5-pentanediamine and cystamine, heating to 50°C under nitrogen protection, controlling the dropping rate to keep the reaction temperature from exceeding 60°C, and maintaining the reaction at 60°C for 24 hours after the dropping is completed to obtain the modified polyaspartic acid ester.

[0043] In this process, the reaction is a Michael addition reaction, with diethyl maleate, 2-methyl-1,5-pentanediamine and cystamine as reactants. Diethyl maleate is a molecule containing a carbon-carbon double bond (C=C), with an electron-withdrawing ester group attached to each end of the double bond. In the reaction, it acts as a Michael acceptor. Due to the strong electron-withdrawing effect of the two ester groups, the electron cloud density on the carbon-carbon double bond decreases, creating empty orbitals that are easily attacked by nucleophiles. 2-Methyl-1,5-pentanediamine has a primary amine group at each end and a side methyl group. During the reaction, the two primary amine groups can react with two diethyl maleate molecules respectively, linking them together to form a long polymer chain. Simultaneously, the methyl group on the side chain creates steric hindrance, reducing the reactivity of newly formed secondary amine groups in the product, thus extending the pot life of the final topcoat. Cystamine has a primary amine group at each end, with the same reaction mechanism. It is mainly used to introduce disulfide bonds. Disulfide bonds are dynamic covalent bonds that can break when stimulated and reform after the stimulus disappears, thereby improving the self-healing ability of the topcoat. In the reaction, the nitrogen atom of the primary amine group on the 2-methyl-1,5-pentanediamine or cystamine molecule has a lone pair of electrons, making it electron-rich and acting as a nucleophile. The electron-deficient carbon-carbon double bond on the diethyl maleate molecule acts as an electrophile. The nitrogen atom on the amine group attacks one of the carbon atoms in the diethyl maleate double bond. After the nitrogen atom attacks the double bond, the π electrons of the double bond transfer to the other carbon atom, forming a negatively charged carbanion intermediate. This positively charged nitrogen atom releases a proton, and simultaneously, the negatively charged carbanion... The carbon atom in the electric field captures a proton from the environment or directly from the amine group. Eventually, the proton is transferred, and the original primary amine group is transformed into a secondary amine group, which forms a stable CN single bond with the original double-bonded carbon atom, forming a stable aspartic ester. The reaction can be simplified as: R-NH2+EtOOC-CH=CH-COOEt→EtOOC-CH(NH-R)-CH2-COOEt. Since the amines used are all diamines, the reaction will continue and eventually generate a copolymer.

[0044] Understandably, in the embodiments of this application, through copolymerization, disulfide bonds with dynamic reversibility are incorporated as part of the covalent bonds into the molecular backbone of polyaspartic acid ester, giving the entire polymer network potential repair capabilities. The introduction of 2-methyl-1,5-pentanediamine, with its side-chain methyl group creating steric hindrance, reduces the reactivity of the secondary amine group in the product, extending the pot life of the topcoat. The lone pair electrons on the amine group are nucleophilic, and the double bond of diethyl maleate is activated by two electron-withdrawing ester groups, resulting in a decrease in the electron cloud density on the double bond, making it more susceptible to nucleophilic attack. During the reaction, the nitrogen atoms in the primary amine groups of 2-methyl-1,5-pentanediamine and cystamine act as nucleophiles, performing nucleophilic addition to the electron-deficient carbon-carbon double bond in diethyl maleate, forming a stable secondary amine group and aspartic acid ester structure. The introduction of cystamine allows some polymer segments to be connected by disulfide bonds.

[0045] In some embodiments, the mass ratio of IPDI trimer, POSS-isocyanate nanohybrid, urea-based supramolecular thickener, and latent organic bismuth catalyst is 100:15~20:0.3~0.5:0.2~0.3.

[0046] In some embodiments, the weight ratio of modified polyaspartic ester, 3-aminopropyltrimethoxysilane and fluorinated segment polyaspartic ester is 95~100:3~5:0.5.

[0047] In some embodiments, the molar ratio of octa(3-hydroxypropyl)silsesquioxane to PDI monomer is 1:8~10, and the weight of dibutyltin dilaurate catalyst is 0.05% of the total weight of octa(3-hydroxypropyl)silsesquioxane and PDI monomer.

[0048] In some embodiments, the molar ratio of diethyl maleate, 2-methyl-1,5-pentanediamine and cystamine is 2:0.9~1:0.05~0.07.

[0049] like Figure 1 As shown, one embodiment of this application discloses a method for preparing a high-performance solvent-free blade wear-resistant self-healing topcoat, comprising the following steps:

[0050] Step 1, Preparation of Component A: Add IPDI trimer to a dry mixing vessel, add POSS-isocyanate nano-hybrid and stir for 30 minutes, add urea-based supramolecular thickener and stir until a uniform gel is formed, add latent organic bismuth catalyst and stir at 100-150 rpm for 10 minutes, then seal and package to obtain Component A.

[0051] It is understood that all isocyanate reactants were premixed in component A of this application embodiment, and the urea-based supramolecular thickener imparts excellent anti-sagging properties, facilitating thick coating application; the latent organobismuth catalyst ensures that the system does not react prematurely before being mixed with component B.

[0052] Step 2, Preparation of Component B: Add the modified polyaspartic acid ester to a dry mixing tank, add 3-aminopropyltrimethoxysilane and stir until homogeneous, add the fluorinated polyaspartic acid ester and continue stirring until homogeneous, then seal and package to obtain Component B.

[0053] It is understood that in component B of this application embodiment, all amine reactants and additives are premixed. During the subsequent topcoat spraying process, 3-aminopropyltrimethoxysilane preferentially reacts with the blade substrate in the early stage of topcoat spraying to form strong covalent bonds. Fluorinated polyaspartic acid ester migrates to the surface of the topcoat during the curing process due to the low surface energy of its fluorinated segments. The secondary amine groups on the modified polyaspartic acid ester have strong electron-donating ability, which enhances the electron-donating ability of nitrogen atoms and can activate the latent organobismuth catalyst in component A.

[0054] Step 3, Spraying and Curing: Grind the leading edge of the blade substrate to a roughness of Ra 3~5μm and clean and dry it with anhydrous ethanol. Mix components A and B using a two-component high-pressure airless spraying device, heat to 60℃, and spray onto the substrate surface at a spraying pressure of 20~25MPa. The single wet film thickness is 500~800μm. Allow it to cure naturally for 24 hours at an ambient temperature of 10~35℃ and a relative humidity of 50%~80% until it is surface dry. The performance is complete after 7 days, resulting in a high-performance solvent-free blade wear-resistant self-healing topcoat.

[0055] When components A and B are mixed, two reactions occur, the main one being the polyurea formation reaction. The isocyanate components IPDI trimer and POSS-isocyanate nanohybrids in component A provide the required isocyanate groups, while the resin components modified polyaspartic acid ester and 3-aminopropyltrimethoxysilane in component B provide amines that react with -NCO. When components A and B are mixed, the nitrogen atom on the amine group in component B will rapidly attack the electron-deficient carbon atom on the isocyanate group in component A. The reaction can be simplified as follows: R1-NH2+O=C=N-R2→R1-NH-C(=O)-NH-R2, R1-NH-R2+O=C=N-R3→R1-N(R2)-C(=O)-NH-R3. Simultaneously, a silane coupling reaction occurs on the surface of the blade substrate. In the initial stage of spraying, when the moisture content is high, the silane end of 3-aminopropyltrimethoxysilane undergoes hydrolysis, and the methoxy group is converted into a hydroxyl group: R-Si(OCH3)3+3H2O→R-Si(OH)3+3CH3OH. The generated silanol group will dehydrate and condense with the hydroxyl group on the surface of the polished blade substrate to form a stable covalent bond. At the same time, the silanol groups will also dehydrate and condense with each other to form a stable siloxane covalent bond.

[0056] It is understood that the curing process of the topcoat after spraying in the embodiments of this application can be divided into three stages. In the first stage, due to the shear-thinning effect of the thickener in the topcoat, the topcoat will flow and level on the substrate surface. Under the action of 3-aminopropyltrimethoxysilane, the topcoat and the substrate are covalently bonded, providing strong adhesion. In the second stage, the secondary amine groups on the surface of the modified polyaspartic acid ester, acting as basic substances, gradually unwind their complex structure upon contact with the latent organobismuth catalyst, releasing highly active organobismuth catalytic centers. Once activated, the catalyst rapidly accelerates the polyurea addition reaction between the isocyanate reactants in component A and the amine reactants in component B. At this point, with the formation of the polyurea network, the polarity of the system increases rapidly. The fluorinated segments of the polyaspartic acid ester have extremely low surface energy and are thermodynamically incompatible with the polar polyurea network. To minimize the free energy of the entire system, these fluorinated molecules spontaneously migrate from the interior of the system to the interface between the paint film and the air, forming a fluorine-rich surface layer. The accelerated polyurea reaction allows the paint film to dry quickly, preventing dust contamination. The fluorine-rich surface layer provides the first line of defense for the paint film, reducing the tangential impact force of raindrops and sand particles by lowering the coefficient of friction, directly reducing the burden on the underlying paint film, and improving the aerodynamic cleanliness of the blades. In the third stage, during the continuous growth and cross-linking of the polyurea network, two parts with vastly different chemical and physical properties begin to undergo microscopic phase separation: the POSS-isocyanate nanohybrid, as a rigid inorganic center, forms a hard phase with extremely high polyurea density around it, giving the paint film high wear resistance; the IPDI trimer and modified polyaspartic acid ester form a relatively flexible polyurea network, constituting a soft phase, giving the paint film impact resistance. The two are connected by covalent bonds, forming an interpenetrating network structure. When the paint film is impacted, the energy is absorbed and dissipated by the flexible soft phase. When the energy is sufficient to generate microcracks, the stress at the crack tip will preferentially break the disulfide bonds with lower energy. Under light, the sulfur free radicals generated by the breakage can undergo disulfide bond exchange reactions, recombine with neighboring disulfide bonds or another sulfur free radical, thereby healing the crack and giving the paint film self-healing ability, greatly extending the service life of the blade.

[0057] Example 1

[0058] This embodiment discloses a high-performance solvent-free blade wear-resistant self-healing topcoat, comprising component A and component B;

[0059] Component A contains IPDI trimer, POSS-isocyanate nano-hybrid, urea-based supramolecular thickener, and latent organic bismuth catalyst.

[0060] Component B contains modified polyaspartic acid ester, 3-aminopropyltrimethoxysilane, and fluorinated segment polyaspartic acid ester.

[0061] In this embodiment, the mass ratio of component A to component B is 115:100.

[0062] In this embodiment, the POSS-isocyanate nanohybrid was prepared by the following method: octa(3-hydroxypropyl)silsesquioxane was dissolved in anhydrous toluene, dibutyltin dilaurate catalyst was added, the mixture was heated to 70°C, PDI monomer was added dropwise while controlling the temperature not to exceed 80°C, and after the addition was complete, the mixture was reacted at 80°C for 4 hours. Toluene was removed by vacuum distillation to obtain the POSS-isocyanate nanohybrid.

[0063] In this embodiment, the modified polyaspartic acid ester was prepared by the following method: diethyl maleate was added to a reaction vessel equipped with a mechanical stirrer, 2-methyl-1,5-pentanediamine and cystamine were added, and the mixture was heated to 50°C under nitrogen protection. The dropping rate was controlled so that the reaction temperature did not exceed 60°C. After the dropping was completed, the mixture was kept at 60°C for 24 hours to obtain the modified polyaspartic acid ester.

[0064] In this embodiment, the mass ratio of IPDI trimer, POSS-isocyanate nanohybrid, urea-based supramolecular thickener, and latent organic bismuth catalyst is 100:17:0.3:0.2.

[0065] In this embodiment, the weight ratio of modified polyaspartic acid ester, 3-aminopropyltrimethoxysilane and fluorinated segment polyaspartic acid ester is 97:3:0.5.

[0066] In this embodiment, the molar ratio of octa(3-hydroxypropyl)silsesquioxane to PDI monomer is 1:10, and the weight of dibutyltin dilaurate catalyst is 0.05% of the total weight of octa(3-hydroxypropyl)silsesquioxane and PDI monomer.

[0067] In this embodiment, the molar ratio of diethyl maleate, 2-methyl-1,5-pentanediamine and cystamine is 2:0.9:0.05.

[0068] This embodiment discloses a method for preparing a high-performance solvent-free blade wear-resistant self-healing topcoat, including the following steps:

[0069] Step 1, Preparation of Component A: Add IPDI trimer to a dry mixing vessel, add POSS-isocyanate nano-hybrid and stir for 30 minutes, add urea-based supramolecular thickener and stir until a uniform gel is formed, add latent organic bismuth catalyst and stir at 150 rpm for 10 minutes, then seal and package to obtain Component A.

[0070] Step 2, Preparation of Component B: Add the modified polyaspartic acid ester to a dry mixing tank, add 3-aminopropyltrimethoxysilane and stir until homogeneous, add the fluorinated polyaspartic acid ester and continue stirring until homogeneous, then seal and package to obtain Component B.

[0071] Step 3, Spraying and Curing: Grind the leading edge of the blade substrate to a roughness of Ra 4μm and clean and dry it with anhydrous ethanol. Mix components A and B using a two-component high-pressure airless spraying device, heat to 60℃, and spray onto the substrate surface at a spraying pressure of 25MPa to a single wet film thickness of 500μm. Allow it to cure naturally for 24 hours at an ambient temperature of 25℃ and a relative humidity of 70% until surface dry. After 7 days, the properties are fully developed, resulting in a high-performance solvent-free blade wear-resistant self-healing topcoat.

[0072] Example 2

[0073] This embodiment discloses a high-performance solvent-free blade wear-resistant self-healing topcoat, comprising component A and component B;

[0074] Component A contains IPDI trimer, POSS-isocyanate nano-hybrid, urea-based supramolecular thickener, and latent organic bismuth catalyst.

[0075] Component B contains modified polyaspartic acid ester, 3-aminopropyltrimethoxysilane, and fluorinated segment polyaspartic acid ester.

[0076] In this embodiment, the mass ratio of component A to component B is 114:100.

[0077] In this embodiment, the POSS-isocyanate nanohybrid was prepared by the following method: octa(3-hydroxypropyl)silsesquioxane was dissolved in anhydrous toluene, dibutyltin dilaurate catalyst was added, the mixture was heated to 70°C, PDI monomer was added dropwise while controlling the temperature not to exceed 80°C, and after the addition was complete, the mixture was reacted at 80°C for 4 hours. Toluene was removed by vacuum distillation to obtain the POSS-isocyanate nanohybrid.

[0078] In this embodiment, the modified polyaspartic acid ester was prepared by the following method: diethyl maleate was added to a reaction vessel equipped with a mechanical stirrer, 2-methyl-1,5-pentanediamine and cystamine were added, and the mixture was heated to 50°C under nitrogen protection. The dropping rate was controlled so that the reaction temperature did not exceed 60°C. After the dropping was completed, the mixture was kept at 60°C for 24 hours to obtain the modified polyaspartic acid ester.

[0079] In this embodiment, the mass ratio of IPDI trimer, POSS-isocyanate nanohybrid, urea-based supramolecular thickener and latent organic bismuth catalyst is 100:20:0.5:0.3.

[0080] In this embodiment, the weight ratio of modified polyaspartic acid ester, 3-aminopropyltrimethoxysilane and fluorinated segment polyaspartic acid ester is 100:5:0.5.

[0081] In this embodiment, the molar ratio of octa(3-hydroxypropyl)silsesquioxane to PDI monomer is 1:8, and the weight of dibutyltin dilaurate catalyst is 0.05% of the total weight of octa(3-hydroxypropyl)silsesquioxane and PDI monomer.

[0082] In this embodiment, the molar ratio of diethyl maleate, 2-methyl-1,5-pentanediamine and cystamine is 2:0.9:0.07.

[0083] This embodiment discloses a method for preparing a high-performance solvent-free blade wear-resistant self-healing topcoat, including the following steps:

[0084] Step 1, Preparation of Component A: Add IPDI trimer to a dry mixing tank, add POSS-isocyanate nano-hybrid and stir for 30 minutes, add urea-based supramolecular thickener and stir until a uniform gel is formed, add latent organic bismuth catalyst and stir at 100 rpm for 10 minutes, then seal and package to obtain Component A.

[0085] Step 2, Preparation of Component B: Add the modified polyaspartic acid ester to a dry mixing tank, add 3-aminopropyltrimethoxysilane and stir until homogeneous, add the fluorinated polyaspartic acid ester and continue stirring until homogeneous, then seal and package to obtain Component B.

[0086] Step 3, Spraying and Curing: Grind the leading edge of the blade substrate to a roughness of Ra 3μm and clean and dry it with anhydrous ethanol. Mix components A and B using a two-component high-pressure airless spraying device, heat to 60℃, and spray onto the substrate surface at a spraying pressure of 25MPa to a single wet film thickness of 500μm. Allow it to cure naturally for 24 hours at an ambient temperature of 10℃ and a relative humidity of 50% until surface dry. After 7 days, the properties are fully developed, resulting in a high-performance solvent-free blade wear-resistant self-healing topcoat.

[0087] Example 3

[0088] This embodiment discloses a high-performance solvent-free blade wear-resistant self-healing topcoat, comprising component A and component B;

[0089] Component A contains IPDI trimer, POSS-isocyanate nano-hybrid, urea-based supramolecular thickener, and latent organic bismuth catalyst.

[0090] Component B contains modified polyaspartic acid ester, 3-aminopropyltrimethoxysilane, and fluorinated segment polyaspartic acid ester.

[0091] In this embodiment, the mass ratio of component A to component B is 117:100.

[0092] In this embodiment, the POSS-isocyanate nanohybrid was prepared by the following method: octa(3-hydroxypropyl)silsesquioxane was dissolved in anhydrous toluene, dibutyltin dilaurate catalyst was added, the mixture was heated to 70°C, PDI monomer was added dropwise while controlling the temperature not to exceed 80°C, and after the addition was complete, the mixture was reacted at 80°C for 4 hours. Toluene was removed by vacuum distillation to obtain the POSS-isocyanate nanohybrid.

[0093] In this embodiment, the modified polyaspartic acid ester was prepared by the following method: diethyl maleate was added to a reaction vessel equipped with a mechanical stirrer, 2-methyl-1,5-pentanediamine and cystamine were added, and the mixture was heated to 50°C under nitrogen protection. The dropping rate was controlled so that the reaction temperature did not exceed 60°C. After the dropping was completed, the mixture was kept at 60°C for 24 hours to obtain the modified polyaspartic acid ester.

[0094] In this embodiment, the mass ratio of IPDI trimer, POSS-isocyanate nanohybrid, urea-based supramolecular thickener and latent organic bismuth catalyst is 100:20:0.4:0.3.

[0095] In this embodiment, the weight ratio of modified polyaspartic acid ester, 3-aminopropyltrimethoxysilane and fluorinated segment polyaspartic acid ester is 100:3:0.5.

[0096] In this embodiment, the molar ratio of octa(3-hydroxypropyl)silsesquioxane to PDI monomer is 1:9, and the weight of dibutyltin dilaurate catalyst is 0.05% of the total weight of octa(3-hydroxypropyl)silsesquioxane and PDI monomer.

[0097] In this embodiment, the molar ratio of diethyl maleate, 2-methyl-1,5-pentanediamine and cystamine is 2:1:0.05.

[0098] This embodiment discloses a method for preparing a high-performance solvent-free blade wear-resistant self-healing topcoat, including the following steps:

[0099] Step 1, Preparation of Component A: Add IPDI trimer to a dry mixing vessel, add POSS-isocyanate nano-hybrid and stir for 30 minutes, add urea-based supramolecular thickener and stir until a uniform gel is formed, add latent organic bismuth catalyst and stir at 150 rpm for 10 minutes, then seal and package to obtain Component A.

[0100] Step 2, Preparation of Component B: Add the modified polyaspartic acid ester to a dry mixing tank, add 3-aminopropyltrimethoxysilane and stir until homogeneous, add the fluorinated polyaspartic acid ester and continue stirring until homogeneous, then seal and package to obtain Component B.

[0101] Step 3, Spraying and Curing: Grind the leading edge of the blade substrate to a roughness of Ra 4μm and clean and dry it with anhydrous ethanol. Mix components A and B using a two-component high-pressure airless spraying device, heat to 60℃, and spray onto the substrate surface at a spraying pressure of 20MPa to a single wet film thickness of 500μm. Allow it to cure naturally for 24 hours at an ambient temperature of 35℃ and a relative humidity of 80% until surface dry. After 7 days, the properties are fully developed, resulting in a high-performance solvent-free blade wear-resistant self-healing topcoat.

[0102] Example 4

[0103] In this embodiment, the mass ratio of component A to component B is 110:100, and the rest is the same as in Example 1.

[0104] Example 5

[0105] In this embodiment, the mass ratio of component A to component B is 120:100, and the rest is the same as in Example 1.

[0106] Comparative Example 1

[0107] In this comparative example, the high-performance solvent-free blade wear-resistant self-healing topcoat A component did not contain POSS-isocyanate nano-hybrids, and its weight was allocated to IPDI trimer, urea-based supramolecular thickener and latent organic bismuth catalyst according to the corresponding weight ratio of the substances. The remaining parts were the same as in Example 1.

[0108] Comparative Example 2

[0109] In this comparative example, the B component of the high-performance solvent-free blade wear-resistant self-healing topcoat did not contain modified polyaspartic ester. Its weight was distributed to 3-aminopropyltrimethoxysilane and fluorinated segment polyaspartic ester according to the corresponding weight ratio of the substances. The remaining parts were the same as in Example 1.

[0110] The performance of the high-performance solvent-free blade wear-resistant self-healing topcoat prepared in Examples 1-3 and Comparative Examples 1-2 was tested. All tests were conducted after the paint film had fully cured.

[0111] 1. Mechanical performance testing

[0112] Pencil Hardness Test: Based on the national standard GB / T 6739-2022 "Determination of Hardness of Paints and Varnishes by Pencil Method";

[0113] Adhesion test: based on national standard GB / T 9286-2021 "Cross-cut test for paints and varnishes";

[0114] Impact Resistance Test: Based on the national standard GB / T 1732-2020 "Determination of Impact Resistance of Coating Films";

[0115] Abrasion Resistance Test: According to the national standard GB / T 1768-2006 "Determination of Abrasion Resistance of Paints and Varnishes - Rotary Rubber Grinding Wheel Method".

[0116] The test results are shown in Table 1 below:

[0117] Table 1. Results of Mechanical Performance Tests

[0118]

[0119] As shown in Table 1, the pencil hardness of Examples 1 and 2 reached 4H, and Example 3 even reached 5H, while Comparative Example 1 was only 2H and Comparative Example 2 was 3H. This indicates that the introduction of POSS-isocyanate nano-hybrids enhanced the hardness of the paint film. Its inorganic nano-cores played a reinforcing role similar to nanofillers in the polymer matrix, significantly improving the surface scratch resistance of the paint film. Example 3 had the highest POSS content, and therefore the highest hardness. The adhesion of Examples 1, 2, 3 and Comparative Example 2 all reached the optimal level 0, with perfect bonding between the paint film and the substrate. However, the adhesion of Comparative Example 1 was level 1, with slight edge peeling, indicating that the adhesion of POSS-isocyanate nano-hybrids was not optimal. The isocyanate groups in the ester nanohybrid not only participate in the main network curing reaction but also synergistically interact with trace amounts of hydroxyl groups on the substrate surface to form strong chemical bonds, thereby enhancing interfacial adhesion. Comparative Example 1 lacks this component and relies solely on the silane coupling agent, resulting in a slight decrease in adhesion. Examples 1, 2, and 3 exhibited impact resistances of 120, 130, and 140 kg·cm, respectively, demonstrating excellent performance. In contrast, Comparative Example 1 showed an impact resistance of only 60 kg·cm, and Comparative Example 2 showed 85 kg·cm. This indicates that the synergistic effect of the POSS-isocyanate nanohybrid and the disulfide-containing modified polyaspartic acid ester imparts excellent impact toughness to the coating. Examples 1, 2, and 3 showed abrasion resistances as high as 8500, 9200, and 10500 revolutions, respectively, while Comparative Example 1 only reached 3500 revolutions, and Comparative Example 2 reached 7500 revolutions. The significant improvement in wear resistance mainly comes from the high hardness brought by POSS nano-hybrids and the self-healing ability brought by modified polyaspartic acid ester. The high hardness directly resists the cutting of abrasive particles, while micro-scratches can be repaired through the dynamic recombination of disulfide bonds, thus delaying the accumulation and expansion of damage.

[0120] 2. Weather resistance and surface performance testing

[0121] Salt spray resistance test: based on national standard GB / T 1771-2021 "Determination of resistance to neutral salt spray in paints and varnishes";

[0122] Hydrophobicity (water contact angle) test: Each group of cured samples was placed horizontally on the sample stage of the measuring instrument. Using a micro-syringe, a drop of 5 μL of deionized water was dropped on the surface of the paint film. After the water droplet stabilized, the water droplet outline was captured by the camera of the contact angle measuring instrument, and the water contact angle was calculated. Five different positions were measured for each sample, and the average value was taken.

[0123] The test results are shown in Table 2 below:

[0124] Table 2. Results of salt spray resistance and water contact angle tests

[0125]

[0126] As shown in Table 2, after 2000 hours of rigorous testing, Examples 1, 2, and 3 exhibited minimal scratch corrosion expansion and intact paint surfaces, demonstrating excellent corrosion resistance. This is because the POSS nanoparticles filled the micropores of the polymer network, forming a dense physical barrier that effectively hindered the penetration of corrosive media such as water and chloride ions. The dense cross-linked network also improved the chemical stability of the coating. Comparative Example 1, without the addition of POSS-isocyanate nano-hybrids, formed a loose polymer network with poor barrier effect, resulting in the weakest salt spray resistance. All groups showed water contact angles greater than 105°, exhibiting good hydrophobicity.

[0127] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the patent coverage of the present invention.

Claims

1. A high-performance solvent-free blade wear-resistant self-healing topcoat, characterized in that, Includes component A and component B; Component A contains IPDI trimer, POSS-isocyanate nano-hybrid, urea-based supramolecular thickener, and latent organic bismuth catalyst. Component B contains modified polyaspartic acid ester, 3-aminopropyltrimethoxysilane, and fluorinated segment polyaspartic acid ester; The POSS-isocyanate nanohybrid is prepared by the following method: octa(3-hydroxypropyl)silsesquioxane is dissolved in anhydrous toluene, dibutyltin dilaurate catalyst is added, the mixture is heated to 70°C, PDI monomer is added dropwise while controlling the temperature not to exceed 80°C, and after the addition is complete, the mixture is reacted at 80°C for 4 hours. Toluene is removed by vacuum distillation to obtain the POSS-isocyanate nanohybrid. The modified polyaspartic acid ester was prepared by the following method: diethyl maleate was added to a reaction vessel equipped with a mechanical stirrer, 2-methyl-1,5-pentanediamine and cystamine were added, and the mixture was heated to 50°C under nitrogen protection. The dropping rate was controlled so that the reaction temperature did not exceed 60°C. After the dropping was completed, the mixture was kept at 60°C for 24 hours to obtain the modified polyaspartic acid ester.

2. The high-performance solvent-free blade wear-resistant self-healing topcoat according to claim 1, characterized in that, The mass ratio of component A to component B is 110~120:

100.

3. The high-performance solvent-free blade wear-resistant self-healing topcoat according to claim 1, characterized in that, The mass ratio of component A to component B is 114~117:

100.

4. The high-performance solvent-free blade wear-resistant self-healing topcoat according to claim 1, characterized in that, The mass ratio of the IPDI trimer, POSS-isocyanate nanohybrid, urea-based supramolecular thickener, and latent organic bismuth catalyst is 100:15~20:0.3~0.5:0.2~0.

3.

5. The high-performance solvent-free blade wear-resistant self-healing topcoat according to claim 1, characterized in that, The weight ratio of the modified polyaspartic acid ester, 3-aminopropyltrimethoxysilane and fluorinated segment polyaspartic acid ester is 95~100:3~5:0.

5.

6. The high-performance solvent-free blade wear-resistant self-healing topcoat according to claim 1, characterized in that, The molar ratio of the octa(3-hydroxypropyl)silsesquioxane to the PDI monomer is 1:8~10, and the weight of the dibutyltin dilaurate catalyst is 0.05% of the total weight of the octa(3-hydroxypropyl)silsesquioxane and the PDI monomer.

7. The high-performance solvent-free blade wear-resistant self-healing topcoat according to claim 1, characterized in that, The molar ratio of diethyl maleate, 2-methyl-1,5-pentanediamine and cystamine is 2:0.9~1:0.05~0.

07.

8. A method for preparing a high-performance solvent-free blade wear-resistant self-healing topcoat as described in any one of claims 1 to 7, characterized in that, Includes the following steps: Step 1, Preparation of Component A: Add IPDI trimer to a dry mixing vessel, add POSS-isocyanate nano-hybrid and stir for 30 minutes, add urea-based supramolecular thickener and stir until a uniform gel is formed, add latent organic bismuth catalyst and stir at 100-150 rpm for 10 minutes, then seal and package to obtain Component A. Step 2, Preparation of Component B: Add the modified polyaspartic acid ester to a dry mixing tank, add 3-aminopropyltrimethoxysilane and stir until homogeneous, add the fluorinated polyaspartic acid ester and continue stirring until homogeneous, then seal and package to obtain Component B. Step 3, Spraying and Curing: Grind the leading edge of the blade substrate to a roughness of Ra 3~5μm and clean and dry it with anhydrous ethanol. Mix components A and B using a two-component high-pressure airless spraying device, heat to 60℃, and spray onto the substrate surface at a spraying pressure of 20~25MPa. The single wet film thickness is 500~800μm. Allow it to cure naturally for 24 hours at an ambient temperature of 10~35℃ and a relative humidity of 50%~80% until it is surface dry. The performance is complete after 7 days, resulting in a high-performance solvent-free blade wear-resistant self-healing topcoat.

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