Coating suitable for propeller of unmanned aerial vehicle as well as preparation method and application of coating

Abstract

The embodiment of the invention provides a coating suitable for a propeller of an unmanned aerial vehicle as well as a preparation method and application of the coating. The coating suitable for the propeller of the unmanned aerial vehicle comprises the following raw materials in parts by weight: 43-65 parts of film-forming resin; 3-5 parts of toughening resin; 10-25 parts of a wear-resistant filler; 10 to 15 parts of a nano filler; 2-5 parts of a weather-resistant auxiliary agent; 2-8 parts of an adhesion promoter; 0.5-2 parts of a low surface additive; 1-5 parts of an auxiliary agent; 15 to 30 parts of a solvent; and 10-20 parts of a curing agent. According to the coating suitable for the unmanned aerial vehicle propeller as well as the preparation method and the application of the coating provided by the embodiment of the invention, through a multi-dimensional design of a high-performance resin matrix, multifunctional filler cooperation, precise interface regulation and control and an elastic cross-linked network, the limit requirement of the unmanned aerial vehicle propeller on a coating in a severe service environment is systematically broken through; the comprehensive performance goals of self-cleaning, long service life and high reliability are achieved.

Description

Technical Field

[0001] This application belongs to the field of coating technology, and in particular relates to a coating suitable for drone propellers, its preparation method and application. Background Technology

[0002] As drone technology penetrates deeper into fields such as aerial surveying, smart logistics, and agricultural plant protection, the service environment of its core component, the propeller, is becoming increasingly harsh. Modern drone propellers, operating at high speeds of ≥3000 rpm, must continuously withstand thermal stress from aerodynamic friction, impact wear from dust particles, and dynamic loads from complex airflow fields. Simultaneously, long-term exposure to outdoor environments requires the material surface to cope with multiple environmental stresses, including moisture erosion at ≥85% relative humidity, ultraviolet radiation at wavelengths of 280nm~400nm, and extreme temperature changes.

[0003] Existing protective coating systems face significant technical bottlenecks in addressing the aforementioned complex stresses: First, conventional polyurethane / acrylic coatings lack sufficient abrasion resistance, exhibiting a wear rate exceeding 0.08g after 2000 sandpaper rubbing tests, leading to rapid deterioration of the propeller's aerodynamic shape. Second, traditional coatings fail to meet weather resistance requirements, exhibiting powdering at level 2 or higher after 1000 hours of accelerated aging, resulting in cracking and peeling of the surface protective layer. More critically, existing coatings generally exhibit adhesion below level 1 for interfacial bonding with carbon fiber composite materials and engineering plastic substrates, easily leading to interfacial debonding under ±3g vibration loads. These defects directly result in decreased propeller aerodynamic efficiency, increased vibration noise, and shortened service life, severely restricting the operational efficiency and economic viability of unmanned aerial vehicle (UAV) systems.

[0004] Therefore, developing a new protective coating system that combines high wear resistance, excellent weather resistance, and good substrate compatibility has become a key technological requirement for breaking through the performance bottleneck of UAV propellers. Summary of the Invention

[0005] In view of this, embodiments of this application provide a coating suitable for UAV propellers, a method for preparing the coating, and its application, to solve the technical problem that the overall performance of existing coatings is insufficient to meet the operating requirements of UAV propellers.

[0006] In a first aspect, embodiments of this application provide a coating suitable for drone propellers, comprising a first component and a second component, wherein the first component comprises the following raw materials in parts by weight: 43-65 parts of film-forming resin; 3-5 parts toughening resin; 10-25 parts of wear-resistant filler; 10-15 parts of nanofiller; 2-5 parts of weather-resistant additives; Adhesion promoter 2-8 parts; 0.5 to 2 parts of low surface finish additive; 1-5 parts of auxiliary agent; Solvent 15-30 parts; The second component comprises the following raw materials in parts by weight: 10-20 parts of curing agent.

[0007] In some embodiments, the weight ratio of the first component to the second component is (5.2~11.05):1.

[0008] In some embodiments, the film-forming resin includes polyaspartic acid ester resin, fluoroethylene-vinyl ether resin, and polyester polyol resin.

[0009] In some embodiments, the toughening resin comprises carboxyl-terminated butadiene-acrylonitrile rubber.

[0010] In some embodiments, the wear-resistant filler includes at least one of silicon carbide and alumina.

[0011] In some embodiments, the nanofiller includes at least one of nano-silica and nano-barium sulfate.

[0012] In some embodiments, the adhesion promoter includes a silane coupling agent.

[0013] In some embodiments, the low surface finish additive includes hydroxyl-containing polydimethylsiloxane.

[0014] In some embodiments, the solvent includes at least one of toluene, xylene, and n-butyl acetate.

[0015] In some embodiments, the curing agent comprises an elastic hexamethylene diisocyanate trimer.

[0016] In some embodiments, the weathering agent includes an ultraviolet absorber and a light stabilizer, and the weight ratio of the ultraviolet absorber to the light stabilizer is (1~1.2):1.

[0017] In some embodiments, the additives include a dispersant, a defoamer, and a leveling agent, and the weight ratio of the dispersant, the defoamer, and the leveling agent is (2~3):1:1.

[0018] Secondly, embodiments of this application provide a method for preparing a coating suitable for UAV propellers, comprising the following steps: The film-forming resin and the solvent are stirred under a first preset condition to obtain a uniform resin solution; The additive, the wear-resistant filler, and the nanofiller are added sequentially to the resin solution, and the mixture is stirred under a second preset condition to obtain a mixture. After grinding the mixture, the toughening resin, the adhesion promoter, the low surface area additive, and the weathering additive are added, and the mixture is stirred under the third preset conditions to obtain the first component.

[0019] In some embodiments, the first preset condition includes: The rotation speed is 500~800 rpm, and the time is 20~40 min.

[0020] In some embodiments, the second preset condition includes: The rotation speed is 1500~1800 rpm, and the time is 30~60 min.

[0021] In some embodiments, the third preset condition includes: The rotation speed is 500~800 rpm, and the time is 15~20 min.

[0022] Thirdly, embodiments of this application provide an application of a coating suitable for drone propellers, wherein the first component and the second component of the coating described in the first aspect are mixed evenly at a weight ratio of (5.2~11.05):1, and coated on the surface of the drone propeller within 8 hours.

[0023] In some embodiments, the coating applied to the surface of the drone propeller within 8 hours includes: The coating can be applied by spraying or brushing, with the following parameters for spraying: spray gun nozzle diameter 1.5~2.0mm, spraying pressure 0.3~0.5MPa; The coating thickness formed on the surface of the UAV propeller is 50±5μm; The conditions for drying and curing the coating include drying at 25°C for 48 hours or drying at 80°C for 2 hours.

[0024] The coatings, preparation methods, and applications for UAV propellers provided in this application have systematically overcome the extreme requirements of UAV propeller coatings under harsh service environments through a multi-dimensional design of high-performance resin matrix, multi-functional filler synergy, precise interface control, and elastic cross-linking network. This not only solves the pain points of existing technologies but also achieves the comprehensive performance goals of self-cleaning, long life, and high reliability. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic flowchart of a method for preparing a coating suitable for UAV propellers provided in an embodiment of this application. Detailed Implementation

[0027] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that the embodiments of this application can also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods are omitted so as not to obscure the description of the embodiments of this application with unnecessary detail.

[0028] It should also be understood that the term "and / or" as used in the specification of embodiments of this application and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0029] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0030] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0031] Furthermore, in the description of the embodiments and the appended claims of this application, the terms "first," "second," "third," etc., are used only for distinguishing descriptions and should not be construed as indicating or implying relative importance.

[0032] In the description of embodiments in this application, references to "some embodiments" or "some embodiments" mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in some embodiments," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiments, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized. "A plurality" refers to two or more.

[0033] In a first aspect, embodiments of this application provide a coating suitable for drone propellers, comprising a first component and a second component, wherein the first component comprises the following raw materials in parts by weight: 43-65 parts of film-forming resin; 3-5 parts toughening resin; 10-25 parts of wear-resistant filler; 10-15 parts of nanofiller; 2-5 parts of weather-resistant additives; Adhesion promoter 2-8 parts; 0.5 to 2 parts of low surface finish additive; 1-5 parts of auxiliary agent; Solvent 15-30 parts; The second component comprises the following raw materials in parts by weight: 10-20 parts of curing agent.

[0034] The two-component coating provided in this application, through a reasonable ratio of film-forming resin, toughening resin, wear-resistant filler and nanofiller, and in conjunction with weather-resistant additives, adhesion promoters and low surface area additives, forms a dense coating with high hardness, high toughness, excellent wear resistance and ultra-weather resistance under the action of a curing agent. This coating significantly improves the comprehensive protection capability of UAV propellers under harsh working conditions such as high-speed rotation, sand and dust impact and long-term outdoor exposure, and effectively solves the technical problems of poor wear resistance, easy powdering and aging and insufficient adhesion to composite material substrates of existing coatings.

[0035] In some embodiments, the weight ratio of the first component to the second component is (5.2~11.05):1. This ratio range ensures sufficient reaction between active functional groups (such as hydroxyl or amino groups) and isocyanate groups (-NCO) in the system, forming a highly cross-linked, dense, and stable three-dimensional network structure, while avoiding coating embrittlement due to excessive curing agent or incomplete cross-linking due to insufficient curing agent. At this ratio, the coating achieves excellent mechanical strength, flexibility, and durability; simultaneously, the higher proportion of the main agent facilitates the uniform dispersion of fillers and functional additives, ensuring the effective performance of multiple functions such as wear resistance, weather resistance, adhesion, and low surface energy. It also facilitates adjustment of application viscosity and pot life, improving the feasibility of on-site coating. Specifically, the weight ratio of the first component and the second component can be any value within the range of (5.2~11.05):1, such as 5.2:1, 5.5:1, 6.2:1, 6.5:1, 6.6:1, 6.8:1, 7:1, 7.2:1, 8:1, 8.2:1, 8.5:1, 8.8:1, 9:1, 9.5:1, 10:1, 11:1, 11.05:1.

[0036] In some embodiments, the film-forming resin includes polyaspartic acid ester resin, fluorinated vinyl ether resin, and polyester polyol resin. Polyaspartic acid ester resin provides high hardness, high abrasion resistance (abrasion loss ≤20mg) and rapid curing properties, effectively resisting sand and dust abrasion under high-speed rotation; fluorinated vinyl ether resin (FEVE) imparts excellent weather resistance (no powdering after ≥5000h of artificial aging) and room temperature curing ability, significantly improving long-term outdoor stability; polyester polyol resin enhances the coating's flexibility and impact resistance, mitigating microcracks caused by vibration.

[0037] Specifically, the polyaspartic acid ester resin is F-420, with a weight of 30-40 parts. Fluoroethylene-vinyl ether resin (FEVE) has a weight of 10-20 parts. Polyester polyol resin has a weight of 3-5 parts. In this embodiment, F-420 (polyaspartic acid ester resin, 30-40 parts) serves as the main film-forming resin, providing high hardness and excellent wear resistance (wear loss ≤20mg), effectively resisting sand and dust impacts and air friction under high-speed propeller rotation (≥3000rpm), significantly reducing wear. FEVE resin (fluoroethylene-vinyl ether resin, 10-20 parts) synergistically imparts superior weather resistance (no powdering after ≥5000h of artificial aging) and strong adhesion, solving the problems of coating aging and substrate debonding caused by ultraviolet radiation, high temperature, and humid environments. A small amount of polyester polyol resin (3-5 parts) is added to precisely improve the coating's flexibility and impact resistance, avoiding protective failure due to brittle cracking under high-speed vibration. Through synergistic optimization of the weight ratio, F-420 dominates abrasion resistance, FEVE ensures weather resistance and adhesion, and polyester polyol balances hardness and elasticity, forming a comprehensive performance system of high abrasion resistance, ultra-weather resistance, high adhesion and vibration resistance. This system systematically overcomes the core defects of existing coatings, such as poor abrasion resistance (>0.08g), weak weather resistance (1000h chalking ≥2 level) and insufficient adhesion (≥1 level).

[0038] In applications, film-forming resins include polyaspartic acid ester resin, fluoroethylene-vinyl ether resin, and polyester polyol resin in a ratio of (1.5~4):1:(0.075~0.17) to balance hardness and toughness. Among them, polyaspartic acid ester resin F-420 provides high hardness (pencil hardness ≥2H) and weather resistance; FEVE resin has low surface tension and excellent weather resistance; it also helps to improve the hydrophobicity of the coating and synergistically enhances the self-cleaning ability with low surface additives; polyester polyol resin has high crosslinking density and high toughness, and synergistically improves the elongation at break of the coating with toughening resin.

[0039] In some embodiments, the toughening resin comprises carboxyl-terminated nitrile butadiene rubber (CTBN). In UAV propeller coatings, the use of CTBN as a toughening resin significantly improves the overall performance of the coating. CTBN utilizes its unique island-structure toughening mechanism to significantly enhance toughness while maintaining high hardness: its active carboxyl groups can chemically react with film-forming resins (such as FEVE and polyaspartic acid ester) to form a uniformly dispersed rubber phase, effectively absorbing the vibration and airflow disturbance energy generated under high-speed rotation, thus preventing the generation and propagation of microcracks.

[0040] Furthermore, the toughening effect of CTBN improves the elongation at break and impact strength of the coating, while essentially maintaining its hardness, heat resistance, and chemical resistance, perfectly resolving the contradiction of high hardness and low toughness in existing coatings. Particularly under dynamic load conditions, CTBN significantly enhances the coating's fatigue resistance, preventing peeling caused by repeated stress. In addition, the carboxyl groups of CTBN can form chemical bonds with carbon fiber composites, engineering plastics, and other substrates, effectively improving interfacial adhesion and solving the problem of weak adhesion between existing coatings and low surface energy substrates. This toughening mechanism enables the coating to maintain high wear resistance (wear loss ≤ 0.02g) while possessing excellent flexibility and impact resistance, ensuring the long-term stable operation of the UAV propeller in harsh flight environments and significantly extending the propeller's service life.

[0041] In some embodiments, the wear-resistant filler includes at least one of silicon carbide and alumina. Silicon carbide has a Mohs hardness of 9.5 (second only to diamond) and excellent wear resistance (wear rate is only 1 / 100 of that of metal materials), effectively resisting sand and dust impacts and air friction under high-speed rotation conditions, significantly extending the propeller's service life. Alumina filler enhances the mechanical strength and wear resistance of the coating. Its fine-grained filler provides higher mechanical strength in epoxy resin systems, synergistically forming a dense structure with silicon carbide, improving overall wear resistance. The combination of the two not only solves the problem of poor wear resistance in existing coatings, but also, through the high hardness of silicon carbide and the reinforcing effect of alumina, enables the coating to maintain high wear resistance while possessing excellent high-temperature resistance and chemical stability, allowing the UAV propeller to operate stably for a long time in harsh outdoor environments, significantly reducing maintenance frequency and costs.

[0042] In some embodiments, the nanofiller includes at least one of nano-silica and nano-barium sulfate. Using at least one of nano-silica and nano-barium sulfate as the nanofiller significantly improves the overall protective performance of the coating. Nano-silica, with its high specific surface area and surface hydroxyl content, can form a dense network structure, greatly improving the coating's strength, smoothness, and self-cleaning ability. Simultaneously, it exhibits an absorption rate of over 70% for ultraviolet light with wavelengths below 400nm, effectively resisting UV aging and extending the coating's service life. Nano-barium sulfate provides high whiteness and strong chemical inertness, significantly improving the coating's weather resistance, chemical corrosion resistance, and gloss. Its high specific surface area makes the coating more uniform and dense. In some embodiments, the two work synergistically, solving the weather resistance defect of existing coatings that exhibit grade 2 or higher chalking after 1000 hours of artificial aging, and overcoming the insufficient wear resistance problem of abrasion loss >0.08g. This allows the coating to effectively resist multiple environmental stresses such as sand and dust impact, ultraviolet radiation, high temperature, and humidity under high-speed rotation (≥3000rpm) conditions, ensuring the long-term stable operation of the UAV propeller.

[0043] In some embodiments, the adhesion promoter includes a silane coupling agent. Specifically, the silane coupling agent is KH-550. Using KH-550 (γ-aminopropyltriethoxysilane) as a silane coupling agent-type adhesion promoter allows its amino groups to chemically bond with the hydroxyl / carboxyl groups on the surface of carbon fiber composites and engineering plastic substrates. Simultaneously, its alkoxy groups crosslink with film-forming resins (such as FEVE or polyaspartic acid ester) to form a stable interfacial transition layer, significantly improving the bonding strength between the coating and the substrate. This effectively solves the coating debonding problem caused by low surface energy substrates, ensuring the coating maintains its integrity over a long period under high-speed rotational vibration, high temperature, and high humidity environments, and avoiding propeller aerodynamic performance degradation caused by interfacial failure.

[0044] In some embodiments, the low-surface-weight additive includes hydroxyl-containing polydimethylsiloxane. As a low-surface-weight additive, hydroxyl-containing polydimethylsiloxane significantly reduces the surface energy of the coating, imparting excellent hydrophobic and oleophobic properties to the coating, making it difficult for dust, rainwater, and oily stains to adhere, thus achieving a self-cleaning effect. Its hydroxyl functional groups can undergo cross-linking reactions with film-forming resins (such as FEVE and polyaspartic acid ester) to form a uniform and dense surface film, effectively resisting sand and dust impacts and air friction, while maintaining coating transparency and not affecting propeller aerodynamic performance. Hydroxyl-containing polydimethylsiloxane possesses wide temperature stability from -50°C to 200°C, low surface tension, and excellent chemical inertness, significantly improving the weather resistance of the coating in harsh environments such as high temperature, high humidity, and ultraviolet radiation. It solves the problems of easy contamination and difficulty in cleaning existing coatings, keeping the propeller surface clean for a long time, maintaining flight efficiency, reducing maintenance frequency, and extending service life.

[0045] In some embodiments, the solvent includes at least one of toluene, xylene, and n-butyl acetate. Preferably, n-butyl acetate is used as the solvent. The preferred use of n-butyl acetate as a solvent not only solves the problems of high toxicity, high VOCs, and poor application compatibility of traditional solvents, but also significantly improves the leveling properties, adhesion, environmental friendliness, and weather resistance of the coating through its synergistic effect with film-forming resins, fillers, and curing agents. This enables drone propellers to achieve long-term stable operation in high-speed rotation and harsh outdoor environments, while meeting the requirements of green production and health and safety.

[0046] In applications, n-butyl acetate exhibits excellent solubility, demonstrating high solubility for polar film-forming resins such as polyaspartic acid ester resin and FEVE resin. This ensures uniform dispersion of the resin system and avoids film defects caused by compatibility issues. Its evaporation rate falls between toluene and xylene, providing coatings with longer leveling time, effectively eliminating brush or spray marks, forming a smooth and dense film, and improving coating gloss and uniformity. It enhances the wetting properties of coatings on complex substrates (such as carbon fiber composites and engineering plastics), assists adhesion promoters (such as KH-550), and further strengthens the bond between the coating and the substrate. Compared to toluene and xylene (high VOC content and high toxicity), n-butyl acetate has a lower VOC content (<300g / L) and a fruity, non-irritating odor, complying with environmental regulations such as GB 18581-2009 and reducing health risks during construction. Furthermore, butyl acetate exhibits excellent solubility for FEVE resin and polyaspartic acid ester resin, avoiding resin precipitation problems caused by polarity differences in traditional solvents and ensuring the stability of the coating system. Its moderate polarity facilitates the uniform dispersion of fillers such as nano-silica and nano-barium sulfate, preventing agglomeration and improving coating density and abrasion resistance. The volatility of butyl acetate can regulate the reaction rate of the elastic HDI trimer curing agent, preventing coating cracking caused by excessively rapid curing, while ensuring sufficient cross-linking to form a high-hardness, high-elasticity network structure.

[0047] In some embodiments, the curing agent includes an elastic hexamethylene diisocyanate trimer. The elastic HDI trimer, acting as a curing agent, undergoes a highly efficient cross-linking reaction with film-forming resins (such as FEVE resin and polyaspartic acid ester resin) through the characteristics of aliphatic polyisocyanates, forming a highly cross-linked, highly elastic, and flexible three-dimensional network structure. Its technical effects are manifested in: significantly improving the vibration resistance of the coating; enhancing weather resistance and yellowing resistance; and optimizing mechanical properties. The synergistic effect of this curing agent and the first component precisely solves the three major technical bottlenecks of existing coatings caused by defects in the curing agent system: poor wear resistance, easy chalking, and weak adhesion, providing crucial support for the long-term stable operation of UAV propellers in harsh outdoor environments.

[0048] In some embodiments, the weather-resistant additive includes an ultraviolet absorber and a light stabilizer, and the weight ratio of the ultraviolet absorber to the light stabilizer is (1~1.2):1. Specifically, the ultraviolet absorber is UV-400, and the light stabilizer is HALS-944. The ultraviolet absorber UV-400 (benzotriazole) and the light stabilizer HALS-944 work synergistically in an optimized weight ratio of (1~1.2):1. UV-400 efficiently absorbs ultraviolet light in the 290-400nm band, blocking the direct attack of UV light on the coating molecules; HALS-944 interrupts the degradation chain reaction by capturing free radicals generated by photo-oxidation. The two form a dual protection mechanism of "absorption-blocking". This ratio ensures a dynamic balance between UV absorption and free radical scavenging, avoiding performance imbalances caused by excessive amounts of a single additive (such as excessive UV absorbers causing photosensitization, and excessive HALS affecting coating transparency). This allows the coating to achieve ≥5000 hours of chalk-free operation in artificial xenon lamp aging tests, far exceeding the existing coatings' ≥2 chalking level defect after 1000 hours. At the same time, it maintains high transparency and aerodynamic surface cleanliness, completely solving the coating aging and chalking problems caused by ultraviolet rays, high temperatures, and humid environments, and ensuring the propeller's long-term stable operation in harsh outdoor environments.

[0049] In some embodiments, the additives include a dispersant, a defoamer, and a leveling agent, and the weight ratio of the dispersant, defoamer, and leveling agent is (2~3):1:1. The dispersant is BYK-163, the defoamer is BYK-052, and the leveling agent is BYK-333.

[0050] BYK-163, a polyacrylate polymeric dispersant, adsorbs onto the surfaces of nanofillers (such as silica and barium sulfate) and wear-resistant fillers (such as silicon carbide and alumina) through anchoring groups, forming charge repulsion or steric hindrance effects to prevent filler agglomeration. It controls the filler particle size distribution to ≤1μm (D50), ensuring coating density and wear resistance (wear loss ≤0.02g); avoids batch-to-batch performance fluctuations caused by filler sedimentation, extending coating shelf life; reduces light scattering caused by filler agglomeration, maintaining coating transparency (transmittance >90%), making it suitable for applications requiring the maintenance of propeller aerodynamic shape.

[0051] The silicone-based defoamer BYK-052 reduces local surface tension, disrupting the elasticity of the bubble film and causing the bubbles to burst rapidly. During spraying or brushing, it achieves a defoaming efficiency of 99%, completely eliminating defects such as pinholes and fisheyes. Its non-silicone structure avoids silicone residue and has no negative impact on leveling properties. It maintains defoaming stability even under high-speed rotating spraying conditions, ensuring a smooth coating surface.

[0052] The polyether-modified silicone leveling agent BYK-333 promotes film flow and leveling by reducing the surface tension of coatings, while simultaneously regulating the interfacial tension gradient. By controlling the leveling time to 30-60 seconds, it eliminates surface defects such as brush marks and orange peel, achieving a coating gloss ≥90 GU. It also assists adhesion promoters (such as KH-550) in wetting low surface energy substrates (such as carbon fiber composites), enhancing interfacial adhesion. In synergy with n-butyl acetate solvent, it optimizes the solvent evaporation curve, preventing sagging or whitening.

[0053] BYK-163 stabilizes filler dispersion, reducing microbubble formation caused by filler flocculation; BYK-052 specifically eliminates residual bubbles. Together, they achieve a dual-effect control of prevention and elimination, ensuring a defect-free paint film. BYK-163 ensures uniform filler distribution, providing a uniform film-forming base for leveling agent BYK-333; BYK-333 further optimizes surface tension, enabling uniform filler arrangement and improving coating density. The low surface tension of BYK-333 assists defoamer BYK-052 in rapidly migrating to the bubble interface, accelerating bubble collapse, while avoiding pinholes caused by excessive defoamer migration.

[0054] Secondly, such as Figure 1 As shown in the figure, this application provides a method for preparing a coating suitable for UAV propellers, including the following steps: S10. The film-forming resin and solvent are stirred under the first preset conditions to obtain a uniform resin solution. S20. Add additives, wear-resistant fillers and nanofillers to the resin solution in sequence, and stir under the second preset condition to obtain a mixture; S30. After grinding the mixture, add toughening resin, adhesion promoter, low surface area additive and weathering additive, and continue stirring under the third preset condition to obtain the first component.

[0055] The coating preparation method of this application systematically solves the technical bottlenecks of existing coatings in terms of filler dispersion, functional additive distribution, and coating uniformity through a scientific stepwise mixing and grinding process. Specifically: First, the film-forming resin and solvent are mixed to form a uniform resin solution, providing an ideal substrate for subsequent filler dispersion; then, additives, wear-resistant fillers, and nanofillers are added sequentially. The additives (such as dispersants) pre-encapsulate the fillers to prevent filler agglomeration, and the particle size distribution of wear-resistant fillers (silicon carbide, alumina) and nanofillers (silicon dioxide, barium sulfate) is controlled to ≤1μm (D50), significantly improving the coating density and wear resistance.

[0056] The mixture is ground to further refine the filler particles to the nanoscale, eliminating micro-agglomerates and ensuring that the nanofillers (such as nano-silica) can form a dense network structure, significantly improving the coating's weather resistance and self-cleaning ability. After grinding, toughening resin, adhesion promoter (such as KH-550), low surface area additives (such as hydroxyl-containing polydimethylsiloxane), and weather-resistant additives are added to prevent these key functional components from being adsorbed and ineffective by the filler. This ensures that the adhesion promoter forms a chemical bond with the carbon fiber / engineering plastic substrate, the low surface area additives are evenly distributed to give the coating hydrophobic and oleophobic properties, and the weather-resistant additives (such as UV-400 and HALS-944) work synergistically to achieve a dual protection mechanism of absorption and blocking. This preparation method enables the coating to maintain high hardness while possessing high wear resistance, excellent weather resistance, and strong adhesion. It effectively addresses the protection needs of drone propellers in harsh environments such as high-speed rotation, sand and dust impact, high temperature, high humidity, and ultraviolet radiation, significantly extending the propeller's service life, reducing maintenance frequency, and providing reliable protection for the stable operation of drones in fields such as aerial photography, logistics, and agricultural plant protection.

[0057] In some embodiments, the first preset conditions include: a rotation speed of 500-800 rpm and a time of 20-40 min. Specifically, the rotation speed can be 500 rpm, 550 rpm, 600 rpm, 650 rpm, 700 rpm, 750 rpm, 800 rpm, etc. The time can be 20 min, 25 min, 30 min, 40 min, etc. This stage, through appropriate rotation speed and time, ensures that the film-forming resin and solvent are fully mixed to form a uniform resin solution, ensuring that the resin molecular chains are fully extended and completely dissolved in the solvent, avoiding resin precipitation or gelation due to excessively high local concentrations. This condition satisfies the initial dispersion requirements of the resin-solvent system while avoiding excessive shearing that damages the resin molecular structure, laying a stable foundation for the subsequent addition of fillers and additives, while reducing energy consumption and improving production efficiency.

[0058] In some embodiments, the second preset conditions include: a rotation speed of 1500~1800 rpm and a time of 30~60 min. Specifically, the rotation speed can be 1500 rpm, 1550 rpm, 1600 rpm, 1650 rpm, 1700 rpm, 1750 rpm, 1800 rpm, etc. The time can be 30 min, 35 min, 40 min, 45 min, 50 min, 55 min, 60 min, etc. This stage achieves efficient dispersion of additives, wear-resistant fillers, and nanofillers through high-speed stirring (1500~1800 rpm) and extended stirring time (30~60 min). High-speed shear force can effectively break up filler agglomerates, and combined with the anchoring effect of additives (such as dispersant BYK-163), the fillers (such as silicon carbide, alumina, and nano silica) are uniformly dispersed to a micron-level particle size (D50≤1μm), significantly improving the interfacial bonding strength between the filler and the resin matrix. Meanwhile, the defoamer (BYK-052) fully migrates to the bubble interface during the stirring process, eliminating dynamic bubbles caused by the addition of fillers, avoiding paint film defects (such as pinholes and orange peel), and providing a stable slurry system for subsequent grinding processes.

[0059] In some embodiments, the third preset conditions include: a rotation speed of 500-800 rpm and a time of 15-20 min. Specifically, the rotation speed can be 500 rpm, 550 rpm, 600 rpm, 650 rpm, 700 rpm, 750 rpm, 800 rpm, etc. The time can be 15 min, 16 min, 18 min, 20 min, etc. In this stage, low-speed stirring (500-800 rpm) and short time (15-20 min) are used to gently add the toughening resin, adhesion promoter, low surface area additive, and weather-resistant additive to the dispersed system. Low-speed stirring avoids secondary agglomeration of the dispersed fillers and nanoparticles, while ensuring that the functional additives (such as KH-550, hydroxyl-containing polydimethylsiloxane) are uniformly distributed and fully react or adsorbed with the resin matrix. This condition not only protects the stable dispersion system formed in the early stage, but also maximizes the synergistic effect of adhesion promoters and substrates, low surface additives and resin surfaces through precise mixing, ultimately achieving a comprehensive improvement in coating performance in terms of adhesion (cross-cut test grade 0), self-cleaning properties (contact angle > 100°) and weather resistance (artificial aging ≥ 5000h).

[0060] Thirdly, embodiments of this application provide an application of a coating suitable for drone propellers, wherein the first component and the second component of the coating described in the first aspect are mixed evenly at a weight ratio of (5.2~11.05):1, and coated on the surface of the drone propeller within 8 hours.

[0061] The drone propeller coating application solution provided in this application embodiment ensures precise stoichiometric matching of the film-forming resin and the elastic HDI trimer curing agent in the coating system by mixing the first component and the second component at a precise weight ratio of (5.2~11.05):1 and completing the coating within an 8-hour application period. This time window ensures sufficient construction time (avoiding uneven coating due to excessively rapid curing) and ensures that the coating can fully cross-link and form a dense three-dimensional network structure after coating is completed within 8 hours, thereby achieving the following technical effects: significantly improving the overall performance of the coating, making the abrasion resistance far superior to existing standards, no powdering after ≥5000 hours of artificial aging, and achieving a cross-cut adhesion level of 0. At the same time, it imparts hydrophobic and oleophobic properties to the propeller surface, effectively resisting the impact of sand and dust under high-speed rotation, air friction, and multiple stresses from the outdoor environment. It systematically solves the technical bottlenecks of existing coatings in terms of abrasion resistance, weather resistance, and adhesion, providing a reliable guarantee for the long-term stable operation of drone propellers.

[0062] In some embodiments, coating the surface of the drone propeller within 8 hours includes: The coating can be applied by spraying or brushing, with the following parameters for spraying: spray gun nozzle diameter 1.5~2.0mm, spraying pressure 0.3~0.5MPa; The coating thickness formed on the surface of the drone propeller is 50±5μm; The conditions for drying and curing the coating include drying at 25°C for 48 hours or drying at 80°C for 2 hours.

[0063] This embodiment achieves a multi-dimensional balance between construction efficiency, coating quality, and performance stability through a systematic design of spraying parameters (1.5~2.0mm nozzle diameter, 0.3~0.5MPa pressure), coating thickness (50±5μm), and drying conditions (25℃ / 48h or 80℃ / 2h). This solution not only solves problems such as sagging, bubbles, and poor adhesion caused by improper construction parameters in traditional coatings, but also achieves industry-leading levels in abrasion resistance, weather resistance, and substrate compatibility through precise control of the curing process. This provides a reliable guarantee for the long-term stable operation of UAV propellers under high-speed rotation (≥3000rpm) and harsh outdoor environments.

[0064] In the application of coatings for drone propellers, the mixed coating is applied to the surface by spraying or brushing. By combining specific parameters and drying conditions, the construction efficiency and final performance of the coating can be significantly improved. The specific technical effects are as follows: Optimized design of spraying parameters: spray gun nozzle diameter (1.5~2.0mm) and spraying pressure (0.3~0.5MPa). This coating contains a high proportion of wear-resistant fillers (10~25 parts) and nano-fillers (10~15 parts), resulting in a high system viscosity. A spray gun nozzle diameter of 1.5~2.0mm avoids clogging caused by an excessively small nozzle, while a pressure range of 0.3~0.5MPa atomizes the coating effectively without causing excessive dispersion or substrate damage due to high pressure. By adjusting the pressure and spray gun movement speed, the size and deposition density of atomized particles can be controlled, ensuring uniform coating thickness (50±5μm) and avoiding performance differences caused by localized excessive thickness or thinness. With these parameters, the target thickness can be achieved in a single spray, reducing the time cost of multiple coats, making it particularly suitable for mass production drone propeller coating scenarios.

[0065] With a coating thickness within the range of 50±5μm, combined with the high density of wear-resistant fillers (silicon carbide, alumina) and nanofillers (silicon dioxide, barium sulfate) in the coating, this thickness provides sufficient impact resistance and abrasion resistance while avoiding excessive weight gain that could affect propeller aerodynamic efficiency. Through spraying parameter control, the 50±5μm tolerance range meets the ISO 2808 standard requirements for coating thickness uniformity while avoiding the risk of sagging or cracking due to excessive thickness.

[0066] In application, the combination of a 1.5~2.0mm spray gun nozzle diameter and a 0.3~0.5MPa pressure allows for precise control of the dry film thickness in a single spray coat, avoiding interfacial delamination or uneven drying caused by multiple coats. The different reaction kinetics of the elastic HDI trimer at low and high temperatures, combined with the temperature resistance of FEVE resin and polyaspartic acid ester resin, ensures stable coating performance across a wide temperature range. Matching the 8-hour pot life (applied within 8 hours of mixing) with drying conditions prevents incomplete crosslinking due to decreased curing agent activity, ensuring the coating reaches optimal performance within the specified time.

[0067] Example Example 1 This application provides a coating suitable for UAV propellers, its preparation method, and its application. The preparation method includes the following steps: S10. Stir the film-forming resin and solvent at 500 rpm for 20 min to obtain a uniform resin solution. S20. Add the additives, wear-resistant fillers and nanofillers to the resin solution in sequence, and stir for 40 minutes at a speed of 1500 rpm to obtain a mixture. S30. After grinding the mixture, add toughening resin, adhesion promoter, low surface area additive and weathering additive, and continue stirring at 600 rpm for 15 min to obtain the first component.

[0068] The dosage of each component is shown in Table 1.

[0069] Example 2 It is basically the same as Example 1, except for the amount and weight of each component used, as shown in Table 1.

[0070] Example 3 It is basically the same as Example 1, except for the amount and weight of each component used, as shown in Table 1.

[0071] Table 1. Components and dosages in Examples 1-3

[0072] Performance testing The coatings from Examples 1-3 were mixed in a preset ratio of the first component and the second component (curing agent), and sprayed onto the surface of a carbon fiber propeller sample (300mm×50mm×3mm). The coating thickness was 50±5μm. After curing at 80℃ for 2h, the sample was placed in a standard environment (23±2℃, 50±5%RH) for 24h before testing. Test standards: Cross-cut adhesion (GB / T 9286-1998, 1mm grid spacing), abrasion resistance (GB / T 1768-2021, 500g load, 1000 revolutions), weather resistance (GB / T 1865-2009, QUV-B lamp, irradiance 0.71W / m²@340nm), impact resistance (GB / T 1732-1993), elongation at break (GB / T 1040.3-2006), and water contact angle (JC / T2128-2012, contact angle measuring instrument). Test results are shown in Table 2.

[0073] Table 2 Performance test results for each embodiment

[0074] The coatings provided in this application all exhibit a cross-cut adhesion rating of 0, significantly superior to commercially available coatings, and can meet the coating stability requirements under high-speed propeller rotation. Regarding abrasion resistance, Example 1 shows the lowest abrasion loss (0.018g), thanks to the high hardness of the single silicon carbide filler; Example 3, through filler compounding, controls the abrasion loss at 0.023g, balancing performance and cost. In terms of weather resistance, Examples 1-3 all achieve "no significant chalking after 2000h artificial aging," with Example 2 showing a higher discoloration / gloss loss rating due to its higher content of weather-resistant additives, making it suitable for high UV environments. Regarding hydrophobicity, Examples 2-3 show a water contact angle ≥98°, superior to Example 1, attributed to the synergistic effect of FEVE resin and low surface additives, which improves anti-fouling and anti-icing capabilities.

[0075] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0076] The above-described embodiments are only used to illustrate the technical solutions of the embodiments of this application, and are not intended to limit them. Although the embodiments of this application have been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of the embodiments of this application.

Claims

1. A coating suitable for drone propellers, characterized in that, It includes a first component and a second component, wherein the first component comprises the following raw materials in parts by weight: 43-65 parts of film-forming resin; 3-5 parts toughening resin; 10-25 parts of wear-resistant filler; 10-15 parts of nanofiller; 2-5 parts of weather-resistant additives; Adhesion promoter 2-8 parts; 0.5 to 2 parts of low surface finish additive; 1-5 parts of auxiliary agent; Solvent 15-30 parts; The second component comprises the following raw materials in parts by weight: 10-20 parts of curing agent.

2. The coating for UAV propellers as described in claim 1, characterized in that, The weight ratio of the first component to the second component is (5.2~11.05):

1.

3. The coating for UAV propellers as described in claim 1, characterized in that, The film-forming resin includes polyaspartic acid ester resin, fluoroethylene-vinyl ether resin, and polyester polyol resin.

4. The coating for UAV propellers as described in claim 1, characterized in that, The toughening resin comprises carboxyl-terminated butadiene-acrylonitrile rubber; and / or, The wear-resistant filler includes at least one of silicon carbide and alumina; and / or, The nanofiller includes at least one of nano-silica and nano-barium sulfate; and / or, The adhesion promoter includes a silane coupling agent; and / or, The low surface finish additive includes hydroxyl-containing polydimethylsiloxane; and / or, The solvent includes at least one selected from toluene, xylene, and n-butyl acetate; and / or, The curing agent includes an elastic hexamethylene diisocyanate trimer.

5. The coating for UAV propellers as described in claim 1, characterized in that, The weather-resistant additives include ultraviolet absorbers and light stabilizers, and the weight ratio of the ultraviolet absorbers to the light stabilizers is (1~1.2):

1.

6. The coating for UAV propellers as described in claim 1, characterized in that, The additives include dispersants, defoamers, and leveling agents, and the weight ratio of the dispersant, the defoamer, and the leveling agent is (2~3):1:

1.

7. A method for preparing a coating suitable for UAV propellers as described in any one of claims 1 to 6, characterized in that, Includes the following steps: The film-forming resin and the solvent are stirred under a first preset condition to obtain a uniform resin solution; The additive, the wear-resistant filler, and the nanofiller are added sequentially to the resin solution, and the mixture is stirred under a second preset condition to obtain a mixture. After grinding the mixture, the toughening resin, the adhesion promoter, the low surface area additive, and the weathering additive are added, and the mixture is stirred under the third preset conditions to obtain the first component.

8. The preparation method according to claim 7, characterized in that, The first preset conditions include: Rotation speed of 500~800 rpm, time of 20~40 min; and / or, The second preset condition includes: The rotation speed is 1500~1800 rpm, and the time is 30~60 min; and / or, The third preset condition includes: The rotation speed is 500~800 rpm, and the time is 15~20 min.

9. An application of a coating suitable for drone propellers, characterized in that, The first and second components of the coating according to any one of claims 1 to 6 are mixed evenly at a weight ratio of (5.2 to 11.05):1, and coated on the surface of the drone propeller within 8 hours.

10. The application as described in claim 9, characterized in that, The coating applied to the surface of the drone propeller within 8 hours includes: The coating can be applied by spraying or brushing, with the following parameters for spraying: spray gun nozzle diameter 1.5~2.0mm, spraying pressure 0.3~0.5MPa; The coating thickness formed on the surface of the UAV propeller is 50±5μm; The conditions for drying and curing the coating include drying at 25°C for 48 hours or drying at 80°C for 2 hours.

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