High-weather-resistance light-cured coating with radar infrared stealth and intelligent anti-counterfeiting functions and preparation

Abstract

The invention discloses a high-weather-resistance photocuring coating with radar infrared stealth and intelligent anti-counterfeiting functions and preparation, and relates to the technical field of special functional materials. According to the coating, stealth, anti-counterfeiting and extreme environment tolerance are realized through multi-component collaborative design: matrix resin is prepared by compounding organic fluorine modified epoxy acrylate and polyurethane acrylate, and trifluoro propyl trimethoxy silane and polyoxyethylene ether block copolymer are introduced, so that weather resistance is improved; the photo-initiation system contains a free radical / cation composite initiator and a low-temperature initiator, and supports wide-temperature-range curing. The functional filler comprises a core-shell complex and carbon nanotube / graphene composite powder, and uniform dispersion of the filler is realized through a gradient grinding process. The method is suitable for military equipment camouflage, aerospace protection and criminal investigation anti-counterfeiting, 800-1400 [mu] m thermal radiation matching, radar wave absorption and mobile phone camera readable encryption information are achieved, and an innovative solution is provided for high-end equipment protection and information safety.

Description

Technical Field

[0001] This invention belongs to the field of special functional materials technology, and in particular relates to a high weather-resistant photocurable coating and its preparation for radar infrared stealth and intelligent anti-counterfeiting functions. Background Technology

[0002] Stealth coatings, as core functional materials for the protection of modern defense industries and high-end equipment, have always focused their technological development on core requirements such as multi-spectral electromagnetic wave absorption, extreme environment tolerance, and intelligent anti-counterfeiting. Traditional stealth coating technologies mainly focus on achieving a single function. For example, radar wave absorbing coatings often use magnetic materials such as ferrites and carbonyl iron to reduce the target's radar cross section (RCS) through magnetic loss mechanisms. However, these materials have drawbacks such as high areal density (>1.5 kg / m²) and narrow temperature range (-20℃~80℃), making it difficult to meet the lightweight and wide temperature range requirements of aerospace equipment. Infrared camouflage coatings, on the other hand, rely on doping with specific elements (such as Cr). 3+ Er 3+ Metal oxides can achieve thermal signature camouflage by adjusting infrared emissivity, but they have poor chemical stability (easily react with water and oxygen, causing infrared signature drift) and are incompatible with radar absorption functions, creating a blind spot in protection.

[0003] In recent years, UV curing technology has been introduced into the coatings field due to its advantages such as rapid film formation (<30 seconds) and low VOC emissions (<50g / L). However, its weather resistance defects are significant: traditional acrylic resins are prone to photo-oxidation under ultraviolet irradiation, resulting in yellowing of the coating (ΔYI>5), decrease in hardness (pencil hardness <2H) and adhesion failure (ASTM D3359 grade <3B).

[0004] Although researchers have been able to partially improve weather resistance by adding benzotriazole UV absorbers (such as UV-P) and hindered amine light stabilizers (such as HALS), the multi-component synergistic mechanism remains unclear, and problems such as coating chalking and cracking still exist after long-term outdoor exposure (>5000 hours). Regarding functional compatibility, existing technologies often employ a layered coating strategy, such as first coating a radar-absorbing layer (e.g., carbon nanotube / ferrite composite coating) and then covering it with an infrared camouflage layer (e.g., SiO2-coated CdTe quantum dots). However, weak interfacial bonding (adhesion <2MPa) easily leads to interlayer delamination, and there are frequency band gaps in multi-band absorption performance (e.g., 8-14μm thermal radiation matching rate <85%). Furthermore, traditional anti-counterfeiting technologies rely on optical color-changing materials (such as spiropyran derivatives), whose color development mechanism is singular (only visible light band response), making them easily cracked through physical replication or chemical analysis, lacking dynamic response and multi-dimensional encryption capabilities.

[0005] To address the aforementioned bottlenecks, this invention proposes a high-weather-resistant photocurable stealth anti-counterfeiting coating based on multi-component synergistic design. It overcomes existing technological limitations through three major technological innovations: a broadband absorption and thermal radiation synergistic mechanism; and the use of a CdS:Er... 3+ A gradient distribution design of CdTe core-shell composite (10-15%) and carbon nanotube / graphene composite powder (5-8%) achieves thermal radiation matching (reflectivity <-10dB) and radar wave absorption (attenuation >20dB in the 2-18GHz band), breaking through the performance ceiling of traditional single-band absorbing materials. Enhanced extreme environment tolerance: The introduction of trifluoropropyltrimethoxysilane (3-5%) and polyoxyethylene ether block copolymers (1-3%) forms a weather-resistant network structure through chemical grafting, resulting in an adhesion retention rate >90% after 100 cycles at -55℃ to 150℃ and a salt spray corrosion (ASTM B117) tolerance time >5000 hours. Intelligent anti-counterfeiting and dynamic response: Development... Microcapsules (2-4%) serve as dual-response colorimetric units. Combined with visible light-near-infrared spectral analysis technology from mobile phone cameras, they enable colorimetric activation triggered by both humidity and temperature parameters (ΔE>15), improving the anti-counterfeiting information encryption dimension by 300% compared to traditional solutions.

[0006] This technology solves the core problems of traditional coatings, such as limited functionality, insufficient weather resistance, and easy counterfeiting of anti-counterfeiting technologies, through three-dimensional synergistic innovation of materials, processes, and functions. It provides a revolutionary solution for stealth protection of military equipment, protection in extreme aerospace environments, and anti-counterfeiting of high-end products. Summary of the Invention

[0007] This invention provides a highly weather-resistant photocurable coating and its preparation method that features radar infrared stealth and intelligent anti-counterfeiting functions, thus solving the above problems.

[0008] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution:

[0009] The present invention relates to a high-weather-resistant photocurable coating with radar infrared stealth and intelligent anti-counterfeiting functions, and its preparation method, comprising the following components: matrix resin: 30-40% organic fluorine-modified epoxy acrylate, 15-20% polyurethane acrylate, and 2-8% polyethersulfone (PES); photoinitiation system: 4-6% free radical / cationic composite photoinitiator (184 and TPO compound), and 1-2% low-temperature photoinitiator (Irgacure 369); infrared camouflage filler: CdS:Er 3+ / CdTe core-shell composite 10-15%, nano-alumina (Al2O3) 3-5%; radar absorbing filler: carbon nanotube / graphene composite powder 5-8%, high-temperature resistant silica microspheres (particle size 1-3μm) 3-5%; anti-counterfeiting functional component: CsCdCl3:Br microcapsules 3-5%, Microcapsules 2-4%; Weather-resistant additives: compound light stabilizers (salicylic acid: BDA 1-1.5%, hindered amines: UV-317 2-3%, benzotriazoles: UV-P 4-5%), antioxidants (phosphites 1-2%); Reactive diluents: 1,6-hexanediol diacrylate (HDDA 10-15%), tripropylene glycol diacrylate (TPGDA 5-10%), isobornyl acrylate (IBOA) 3-5%, low-temperature modifier 0-3%.

[0010] As a further description of this technical solution: the glass transition temperature (Tg) of the polyethersulfone (PES) is ≥220℃ and the molecular weight distribution (PDI) is ≤1.5. Carboxyl end groups (-COOH) are introduced through solution polymerization to form a hydrogen bond network with the matrix resin.

[0011] As a further description of this technical solution: the nano-alumina (Al2O3) is surface modified with silane coupling agent (KH-550), with a particle size of 50-100nm, a specific surface area of ​​≥200 m² / g, and an addition amount of 3-5%.

[0012] As a further description of this technical solution: In the gradient grinding process, the infrared camouflage filler and radar absorbing filler are coarsely ground (1200r / min, D90<200μm), and finely ground (1500r / min, D90<15nm) in an environment of -20℃~50℃. A vacuum environment (≤10Pa) is used to prevent the filler from agglomerating.

[0013] As a further description of this technical solution: the two-component curing system has a UV curing wavelength of 365-395nm, an irradiation intensity of 80-120mW / cm², a curing time of 30-60s, and can be cured in a wide temperature range of -10℃ to 50℃ (low-temperature curing requires extending the irradiation time to 90-120s).

[0014] As a further description of this technical solution: the carbon nanotube / graphene composite powder is prepared by chemical vapor deposition, with carbon nanotubes having a diameter of 5-10 nm, graphene layers ≤ 5 layers, a mass ratio of 1:2, and 0.5-1% of a high-temperature resistant binder (silane coupling agent KH-550) is added.

[0015] As a further description of this technical solution: the fluorine content of the organofluorine modified epoxy acrylate is 15-20 wt%, trifluoropropyltrimethoxysilane is introduced through solution polymerization, and 1-3% of a low-temperature resistant modifier (polyoxyethylene ether block copolymer) is added.

[0016] As a further description of this technical solution: the wall material of the anti-counterfeiting functional microcapsule is a polymethyl methacrylate-silica composite film with a wall thickness of 50-100nm and a particle size of 2-5μm, and the capsule is filled with a phase change material (paraffin microcapsule) to achieve temperature-responsive color development.

[0017] As a further description of this technical solution: adding 2-3% toughening monomer (hydroxyethyl acrylate HEA) to the reactive diluent reduces the curing shrinkage rate to below 3% (ASTM D2794).

[0018] As a further description of this technical solution: the coating has an impact resistance of ≥50J (ASTM D2794) at a low temperature of -40℃, a heat distortion temperature of ≥180℃ (ASTM D648) at a high temperature of 150℃, and an adhesion grade of 5B (ASTM D3359).

[0019] As a further description of this technical solution: the pencil hardness of the coating is ≥2H (ASTM D3363), and the flexibility is ≤2mm (GB / T 1731).

[0020] As a further description of this technical solution, it includes the following steps:

[0021] Step S1: Weigh the matrix resin, photoinitiator, and reactive diluent according to the proportions, mix them, and then pre-disperse them;

[0022] Step S2: Gradient grinding of infrared camouflage filler until D90 < 15nm, then adding radar absorbing filler and continuing grinding until D90 < 15nm;

[0023] Step S3: Combine the base resin, photoinitiator, infrared anti-counterfeiting filler, radar-absorbing filler, anti-counterfeiting functional agent, diluent, and additives.

[0024] Step S4: After UV curing, allow the material to cool naturally to room temperature to obtain a coating with a thickness of 10-15 μm.

[0025] As a further description of this technical solution: the coating is used in the following scenarios: military equipment camouflage: covering fighter jet radomes, ship decks, and individual combat uniforms, with 800-1400μm thermal radiation matching (reflectivity <-10dB) and radar wave absorption (2-18GHz band attenuation >20dB); aerospace vehicle protection: coating aircraft engine blades and satellite solar panels, withstanding extreme temperatures of -55℃ to 150℃ and cosmic ray radiation; new energy vehicle components: applied to battery pack shells and charging piles, resistant to electrolyte corrosion (ASTM B117 salt spray >5000h) and high temperature and high humidity environments (no blistering at 85℃ / 85%RH for 5 days); criminal investigation and anti-counterfeiting: producing anti-counterfeiting labels for documents, with encrypted information readable by mobile phone cameras through humidity / temperature dual-response color development (ΔE>15).

[0026] The present invention has the following advantages over the prior art:

[0027] (1) Integrated Functional Design: For the first time, three major functions—radar stealth (2-18GHz attenuation >20dB), infrared stealth (thermal radiation reflectivity <-10dB), and intelligent anti-counterfeiting (temperature / humidity dual response)—are perfectly integrated in a single thin coating (10-15μm), breaking the technical barrier of traditional multi-layer coating.

[0028] (2) Extreme environmental tolerance: Through the synergy of organic fluorine resin and PES, the coating has an ultra-wide temperature range (-55℃~150℃), ultra-long salt spray resistance (>5000h) and high mechanical properties (impact resistance ≥50J, hardness ≥2H), which solves the industry problem of poor weather resistance of UV-cured coatings.

[0029] (3) Wide temperature range curing process: The innovative composite photoinitiation system enables the coating to cure rapidly (30-120s) in a wide temperature range of -10℃ to 50℃, breaking through the dependence of traditional UV curing on room temperature environment and greatly expanding the application scenarios.

[0030] (4) Intelligent anti-counterfeiting upgrade: The fluorescent material is encapsulated using microencapsulation technology to achieve dynamic dual-response color development (ΔE>15) and readability by mobile phone camera, upgrading anti-counterfeiting from static identification to dynamic digital recognition, significantly improving the anti-counterfeiting security dimension.

[0031] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Detailed Implementation

[0032] The technical solutions in the embodiments of the present invention will be clearly and completely described below. 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 skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] Preparation of a high-weather-resistant photocurable coating with radar infrared stealth and intelligent anti-counterfeiting functions:

[0034] Step 1: Gradient dispersion of filler (1) Coarse grinding pretreatment: The infrared camouflage filler (CdS:Er³) is subjected to gradient dispersion (1) coarse grinding pretreatment. + / CdTe core-shell composite + nano Al2O3) and radar absorbing filler (carbon nanotube / graphene composite powder + high temperature resistant SiO2 microspheres) are mixed in proportion. Coarse grinding stage: 0.6-1.0 mm zirconia beads are selected as the grinding media, the rotation speed is 1200 r / min, the grinding time is 2 hours, and the temperature is controlled ≤25℃ (circulating water cooling) so that the filler D90 <200 μm. (2) Fine grinding stage: the grinding media is changed to 0.3-0.5 mm zirconia beads, the rotation speed is increased to 1500 r / min, and the grinding is carried out in a vacuum environment (≤10 Pa) for 2 hours. The temperature is controlled ≤25℃ (circulating water cooling) so that the filler D90 <15 nm and the specific surface area ≥200 m² / g (BET method determination).

[0035] Step 2: Premixing the matrix resin: (1) Add organofluorine modified epoxy acrylate (30-40%), polyurethane acrylate (15-20%), and polyethersulfone (PES, 5-8%) to a stainless steel reactor in proportion. Stir under nitrogen protection (300 r / min) for 30 minutes, and heat to 60℃ to accelerate dissolution. (2) Addition of photoinitiation system: Add free radical / cationic composite initiator (184:TPO=3:1, total 4-6%) and low-temperature initiator Irgacure 369 (1-2%) in stages. (3) Mixing of reactive diluent and additives: Add HDDA (10-15%), TPGDA (5-10%), IBOA (3-5%) and compound light stabilizer (BDA+UV-317+UV-P). (4) Vacuum degassing treatment (-0.095MPa, 30 minutes) to eliminate bubbles.

[0036] Step 3: Preparation of components A and B: (1) Component A (main agent): Add 60% premixed resin, 50% filler (infrared + radar absorbing agent), and reactive diluent to a mixer, and vacuum stir (-0.08MPa, 20 minutes) at a speed of 500r / min to obtain a homogeneous slurry. (2) Component B (curing agent and functional agent): Add 40% resin, the remaining 50% filler, and anti-counterfeiting functional agent ( ), antioxidant mixture. Ultrasonic-assisted dispersion (frequency 28kHz, power 500W, time 15 minutes) to ensure uniform distribution of microcapsules. Mix component A and component B; do not stir at high speed, simply mix at a low speed until homogeneous.

[0037] Step 4: Coating and Curing: (1) Coating process: High-pressure airless spraying (nozzle diameter 0.015mm, pressure 25MPa, atomizing air pressure 0.3MPa). Coating amount: 10-15μm dry film thickness (monitored in real time by film thickness gauge). (2) UV curing parameters: Wavelength 365-395nm (mercury lamp + LED hybrid light source). Irradiance 0-120mW / cm² (calibrated by radiometer).

[0038] Example 1: Standard Military Equipment Camouflage Coating (Baseline Formulation)

[0039] (1) Formula ratio (wt%):

[0040] Matrix resin: 20% organofluorine modified epoxy acrylate; 15% polyurethane acrylate; 3% polyethersulfone (PES)

[0041] Photoinitiation system: 184 and TPO compound (3:1): 5%; Irgacure 369: 2%

[0042] Infrared camouflage filler: CdS:Er 3+ / CdTe core-shell composite: 15%; Nano-alumina (Al2O3, KH-550 modified): 3%

[0043] Radar absorbing filler: Carbon nanotube / graphene composite powder: 8%; High-temperature resistant silica microspheres (particle size 1-3μm): 5%

[0044] Anti-counterfeiting features:

[0045] Weather-resistant additives: Compound light stabilizers: Salicylic acid (BDA): 1.5%, hindered amines (UV-317): 3%; Benzotriazoles (UV-P): 5%; Antioxidants (phosphites): 2%

[0046] Reactive diluents: 1,6-Hexanediol diacrylate (HDDA): 15%; Tripropylene glycol diacrylate (TPGDA): 5%; Isobornyl acrylate (IBOA): 3%; Hydroxyethyl acrylate (HEA, toughening monomer): 0.5%

[0047] (2) Preparation process:

[0048] Gradient grinding of filler: coarse grinding (1200 r / min, 2 h, D90 < 200 μm) → fine grinding (1500 r / min, 2 h, vacuum ≤ 10 Pa, D90 = 12 nm)

[0049] Resin premixing: Stirring at 60℃ under nitrogen protection for 30 min, then adding photoinitiator, reactive diluent, and additives. Vacuum degassing: -0.095 MPa, 30 min.

[0050] Component A and component B are prepared in a certain proportion and mixed.

[0051] Spray coating: Dry film thickness 12μm

[0052] UV curing: 365nm, 100mW / cm², 40s (room temperature 25℃)

[0053] (3) Performance test data:

[0054]

[0055] Example 2: Protective Coating for Aerospace Engine Blades

[0056] (1) Formula ratio (wt%):

[0057] Matrix resin: Organofluorine modified epoxy acrylate: 18%; Polyurethane acrylate: 15%; Polyethersulfone (PES): 5%

[0058] Photoinitiation system: 184 and TPO compound (3:1): 5%; Irgacure 369: 2%

[0059] Infrared camouflage filler: Core-shell complex: 15%; Nano-alumina (Al2O3, KH-550 modified): 5%

[0060] Radar absorbing filler: Carbon nanotube / graphene composite powder: 8%; High-temperature resistant silica microspheres (particle size 1-3μm): 5%

[0061] Anti-counterfeiting functional component: CsCdCl3:Br microcapsules: 3%; Microcapsules: 2%

[0062] Weather-resistant additives: Compound light stabilizers: Salicylic acid (BDA): 1.5%, hindered amines (UV-317): 3%, benzotriazoles (UV-P): 6%; Antioxidants (phosphites): 2%

[0063] Reactive diluents: 1,6-Hexanediol diacrylate (HDDA): 13%; Tripropylene glycol diacrylate (TPGDA): 6%; Isobornyl acrylate (IBOA): 3%; Hydroxyethyl acrylate (HEA): 0.5%

[0064] Low-temperature modifier: Polyoxyethylene ether block copolymer: 2%

[0065] (2) Performance test data:

[0066]

[0067] Example 3: Coating for the outer shell of a new energy vehicle battery pack

[0068] (1) Formula ratio (wt%):

[0069] Matrix resin: 20% organofluorine modified epoxy acrylate; 15% polyurethane acrylate; 3% polyethersulfone (PES)

[0070] Photoinitiation system: 184 and TPO compound (3:1): 5%; Irgacure 369: 2%

[0071] Infrared camouflage filler: CdS:Er 3+ / CdTe core-shell composite: 15%; Nano-alumina (Al2O3, KH-550 modified): 3%

[0072] Radar absorbing filler: Carbon nanotube / graphene composite powder: 8%; High-temperature resistant silica microspheres (particle size 1-3μm): 8%

[0073] Anti-counterfeiting features: :0%; 3%

[0074] Weather-resistant additives: Compound light stabilizers: Salicylic acid (BDA): 1.5%, hindered amines (UV-317): 3%, benzotriazoles (UV-P): 5%; Antioxidants (phosphites): 2%

[0075] Reactive diluents: 1,6-Hexanediol diacrylate (HDDA): 15%; Tripropylene glycol diacrylate (TPGDA): 7%; Isobornyl acrylate (IBOA): 3%; Hydroxyethyl acrylate (HEA): 0.5%

[0076] (2) Performance test data:

[0077]

[0078] Example 4: Anti-counterfeiting label coating (thin coating) for criminal investigation

[0079] (1) Formula ratio (wt%):

[0080] Matrix resin: Organofluorine modified epoxy acrylate: 18%; Polyurethane acrylate: 14%; Polyethersulfone (PES): 3%

[0081] Photoinitiation system: 184 and TPO compound (3:1): 5%; Irgacure 369: 2%

[0082] Infrared camouflage filler: CdS:Er 3+ / CdTe core-shell composite: 12%; Nano-alumina (Al2O3, KH-550 modified): 3%

[0083] Radar absorbing filler: Carbon nanotube / graphene composite powder: 5%; High-temperature resistant silica microspheres (particle size 1-3μm): 5%

[0084] Anti-counterfeiting features: 4%; 3%

[0085] Weather-resistant additives: Compound light stabilizers: Salicylic acid (BDA): 1.5%, hindered amines (UV-317): 3%, benzotriazoles (UV-P): 5%; Antioxidants (phosphites): 2%

[0086] Reactive diluents: 1,6-hexanediol diacrylate (HDDA): 10%; Tripropylene glycol diacrylate (TPGDA): 8%; Isobornyl acrylate (IBOA): 5%; Hydroxyethyl acrylate (HEA): 7.5%

[0087] (2) Performance test data:

[0088]

[0089]

[0090]

[0091] Example 5: High-hardness ship deck coating

[0092] (1) Formula ratio (wt%):

[0093] Matrix resin: 20% organofluorine modified epoxy acrylate; 15% polyurethane acrylate; 3% polyethersulfone (PES)

[0094] Photoinitiation system: 184 and TPO compound (3:1): 5%; Irgacure 369: 2%

[0095] Infrared camouflage filler: CdS:Er 3+ / CdTe core-shell composite: 15%; Nano-alumina (Al2O3, KH-550 modified): 5%

[0096] Radar absorbing filler: Carbon nanotube / graphene composite powder: 10%; High-temperature resistant silica microspheres (particle size 1-3μm): 6%

[0097] Anti-counterfeiting functional component: CsCdCl3:Br microcapsules: 3%; Microcapsules: 2%

[0098] Weather-resistant additives: Compound light stabilizers: Salicylic acid (BDA): 1.5%, hindered amines (UV-317): 3%

[0099] Benzotriazoles (UV-P): 5%; Antioxidants (phosphites): 2%

[0100] Reactive diluents: 1,6-Hexanediol diacrylate (HDDA): 12%; Tripropylene glycol diacrylate (TPGDA): 7%; Isobornyl acrylate (IBOA): 3%; Hydroxyethyl acrylate (HEA): 0.5%

[0101] (2) Performance test data:

[0102]

[0103] Example 6: Low-temperature curing (-10℃) emergency repair coating

[0104] (1) Formula ratio (wt%):

[0105] Matrix resin: 20% organofluorine modified epoxy acrylate; 15% polyurethane acrylate; 3% polyethersulfone (PES)

[0106] Photoinitiation system: 184 and TPO compound (3:1): 5%; Irgacure 369: 3%

[0107] Infrared camouflage filler: Core-shell complex: 15%; Nano-alumina (Al2O3, KH-550 modified): 3%

[0108] Radar absorbing filler: Carbon nanotube / graphene composite powder: 8%; High-temperature resistant silica microspheres (particle size 1-3μm): 5%

[0109] Anti-counterfeiting features: Microcapsules: 3%; Microcapsules: 2%

[0110] Weather-resistant additives: Compound light stabilizers: Salicylic acid (BDA): 1.5%, hindered amines (UV-317): 3%

[0111] Benzotriazoles (UV-P): 5%; Antioxidants (phosphites): 2%

[0112] Reactive diluents: 1,6-Hexanediol diacrylate (HDDA): 12%, Tripropylene glycol diacrylate (TPGDA): 7%, IBOA (isobornyl acrylate): 3%, HEA (hydroxyethyl acrylate): 0.5%

[0113] Low-temperature modifier: Polyoxyethylene ether block copolymer: 3%

[0114] (2) Performance test data:

[0115]

[0116] Based on the systematic experimental verification of the above six embodiments, this high weather-resistant photocurable stealth anti-counterfeiting coating has successfully achieved a synergistic breakthrough in multi-dimensional performance. Its comprehensive performance far exceeds that of traditional single-function coatings, providing solid data support and feasibility proof for its application in the fields of high-end equipment protection and information security.

[0117] Through precise component design and process control, this coating system exhibits outstanding and balanced comprehensive performance: In terms of stealth capabilities, it achieves effective camouflage across a wide frequency band, from microwave (2-18GHz radar wave attenuation >15dB) to infrared (800-1400μm thermal radiation reflectivity <-10dB), meeting the urgent need for multi-spectral compatibility in modern battlefields; in terms of environmental resistance, the coating has withstood extreme temperature cycling from -55℃ to 150℃, 5000 hours of salt spray corrosion, and high-intensity irradiation tests, with a key mechanical and functional performance retention rate exceeding 90%, proving its unprecedented durability; in terms of mechanical properties, it simultaneously possesses superior hardness (up to 4H), excellent adhesion (5B), and outstanding impact resistance (≥50J), solving the industry challenge of balancing high hardness and high toughness.

[0118] Most importantly, this technology demonstrates strong application adaptability. Through flexible formula fine-tuning, specialized products can be derived for different extreme scenarios (such as aerospace, deep-sea ships, and new energy vehicles). It also integrates intelligent anti-counterfeiting and stealth protection functions for the first time. Through humidity / temperature dual-response color development (ΔE>15) and encrypted information readable by mobile phone cameras, it achieves a revolutionary improvement in anti-counterfeiting.

[0119] In summary, this coating not only comprehensively solves the long-standing technical bottlenecks of traditional products in terms of single function, insufficient weather resistance, and poor environmental adaptability, but also successfully constructs a high-performance material platform integrating "stealth-protection-anti-counterfeiting". It provides a reliable and efficient innovative solution for improving the cross-domain survivability and information security level of my country's high-end military equipment, aerospace vehicles and critical infrastructure.

[0120] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A high-weather-resistant photocurable coating with radar infrared stealth and intelligent anti-counterfeiting functions, characterized in that, By weight percentage, it includes the following components: Matrix resin: 30-40% organofluorine modified epoxy acrylate, 15-20% polyurethane acrylate, 2-8% polyethersulfone; Photoinitiation system: 4-6% free radical / cationic composite photoinitiator, 1-2% low temperature photoinitiator; Infrared camouflage filler: CdS:Er 3+ / CdTe core-shell composite 10-15%, nano-alumina 3-5%; Radar absorbing filler: 5-8% carbon nanotube / graphene composite powder, 3-5% high-temperature resistant silica microspheres with a particle size of 1-3μm; Anti-counterfeiting functional components: CsCdCl3:Br microcapsules 3-5%, WO3:Eu 3+ Microcapsules 2-4%; Weather-resistant additives: compound light stabilizers and antioxidants. The compound light stabilizers specifically include: 1-1.5% salicylic acid derivatives: BDA, 2-3% hindered amine derivatives: UV-317, and 4-5% benzotriazole derivatives: UV-P; the antioxidants are 1-2% phosphites. Reactive diluents include 0-15% 1,6-hexanediol diacrylate, 5-10% tripropylene glycol diacrylate, 3-5% isobornyl acrylate, and 0-3% low-temperature modifier.

2. The high weather-resistant photocurable coating with radar infrared stealth and intelligent anti-counterfeiting functions according to claim 1, characterized in that, The polyethersulfone has a glass transition temperature (Tg) ≥220℃ and a molecular weight distribution (PDI) ≤1.

5. Carboxyl end groups (-COOH) are introduced through solution polymerization to form a hydrogen bond network with the matrix resin.

3. The high weather-resistant photocurable coating with radar infrared stealth and intelligent anti-counterfeiting functions according to claim 1, characterized in that, The nano-alumina is surface-modified with KH-550 silane coupling agent, with a particle size of 50-100nm, a specific surface area of ​​≥200m² / g, and an addition amount of 3-5%.

4. The high weather-resistant photocurable coating with radar infrared stealth and intelligent anti-counterfeiting functions according to claim 1, characterized in that, In the gradient grinding process, the infrared camouflage filler and radar absorption filler are coarsely ground at 1200 r / min and D90 < 200 μm; and finely ground at 1500 r / min and D90 < 15 nm in an environment of -20℃ to 50℃, using a vacuum environment of ≤10 Pa to prevent filler agglomeration.

5. The high weather-resistant photocurable coating with radar infrared stealth and intelligent anti-counterfeiting functions according to claim 1, characterized in that, The two-component curing system has a UV curing wavelength of 365-395nm, an irradiation intensity of 80-120mW / cm², and a curing time of 30-60s. It can be cured in a wide temperature range of -10℃ to 50℃. For low-temperature curing, the irradiation time needs to be extended to 90-120s.

6. The high weather-resistant photocurable coating with radar infrared stealth and intelligent anti-counterfeiting functions according to claim 1, characterized in that, The carbon nanotube / graphene composite powder is prepared by chemical vapor deposition. The carbon nanotubes have a diameter of 5-10 nm, the number of graphene layers is ≤5, the mass ratio is 1:2, and a high-temperature resistant binder of 0.5-1% is added. The high-temperature resistant binder is silane coupling agent KH-550.

7. The high weather-resistant photocurable coating with radar infrared stealth and intelligent anti-counterfeiting functions according to claim 1, characterized in that, The fluorine-modified epoxy acrylate has a fluorine content of 15-20 wt%, trifluoropropyltrimethoxysilane is introduced through solution polymerization, and 1-3% of a low-temperature modifier is added. The low-temperature modifier is a polyoxyethylene ether block copolymer.

8. The high weather-resistant photocurable coating with radar infrared stealth and intelligent anti-counterfeiting functions according to claim 1, characterized in that, The anti-counterfeiting functional microcapsules are made of polymethyl methacrylate-silica composite film with a wall thickness of 50-100 nm and a particle size of 2-5 μm. The capsules are filled with phase change material to achieve temperature-responsive color development. The phase change material is paraffin microcapsules.

9. The high weather-resistant photocurable coating with radar infrared stealth and intelligent anti-counterfeiting functions according to claim 1, characterized in that, The active diluent contains 2-3% toughening monomer to reduce the curing shrinkage rate to below 3%. The toughening monomer is hydroxyethyl acrylate (HEA).

10. The high weather-resistant photocurable coating with radar infrared stealth and intelligent anti-counterfeiting functions according to claim 1, characterized in that, The coating has an impact resistance of ≥50J at -40℃, a heat distortion temperature of ≥180℃ at 150℃, and an adhesion rating of 5B.

11. The high weather-resistant photocurable coating with radar infrared stealth and intelligent anti-counterfeiting functions according to claim 1, characterized in that, The coating has a pencil hardness ≥2H and a flexibility ≤2mm.

12. A method for preparing a high weather-resistant photocurable coating with radar infrared stealth and intelligent anti-counterfeiting functions, used to prepare the high weather-resistant photocurable coating with radar infrared stealth and intelligent anti-counterfeiting functions as described in any one of claims 1-11, characterized in that, Includes the following steps: Step S1: Weigh the matrix resin, photoinitiator, and reactive diluent according to the proportions, mix them, and then pre-disperse them; Step S2: Gradient grinding of infrared camouflage filler until D90 < 15nm, then adding radar absorbing filler and continuing grinding until D90 < 15nm; Step S3: Mix the matrix resin, photoinitiator, infrared anti-counterfeiting filler, radar absorbing filler, anti-counterfeiting functional agent, diluent, and additives. Step S4: After UV curing, allow the material to cool naturally to room temperature to obtain a coating with a thickness of 10-15 μm.

13. The application of a high weather-resistant photocurable coating with radar infrared stealth and intelligent anti-counterfeiting functions as described in any one of claims 1-11, characterized in that, The coating is used in the following scenarios: Military equipment camouflage: Covers fighter jet radar domes, ship decks, and individual combat uniforms; 800-1400μm thermal radiation matching and radar wave absorption; thermal radiation matching reflectivity <-10dB; radar wave absorption attenuation >20dB in the 2-18GHz frequency band. Aerospace vehicle protection: Coating aircraft engine blades and satellite solar panels to withstand extreme temperatures of -55℃ to 150℃ and cosmic ray radiation; New energy vehicle components: used in battery pack casings and charging piles, resistant to electrolyte corrosion and high temperature and humidity environments; Criminal investigation and anti-counterfeiting: used to produce anti-counterfeiting labels for documents, with encrypted information that can be read by mobile phone cameras through dual humidity / temperature response color development.

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