A nanoimprinted UV-curable coating composition, its preparation method and application

Abstract

This invention provides a nanoimprinted UV-curable coating composition, its preparation method, and its application. The nanoimprinted UV-curable coating composition, by weight, comprises 10-20 parts of a bifunctional epoxy-terminated perfluoropolyether oligomer, 70-85 parts of an alicyclic epoxy reactive diluent, 3-5 parts of a cationic photoinitiator, 0.1-0.5 parts of a leveling agent, 0.1-0.3 parts of an antifoaming agent, and 1-5 parts of modified silica, wherein the modified silica is cyclohexyl alicyclic epoxy silane coupling agent modified silica. The nanostructure replica fidelity prepared by the nanoimprinted UV-curable coating composition provided by this invention reaches over 99.5%, with no defects, deformation, or sticking; a water contact angle ≥140°; a coating hardness ≥60HD; no scratches after 1500 cycles of steel wool abrasion testing; adhesion grade 0; and resistance to acid and alkali corrosion and UV aging.

Description

Technical Field

[0001] This invention relates to the field of nanoimprint functional coating materials technology, specifically to a nanoimprint UV-curable coating composition, its preparation method, and its application. Background Technology

[0002] Nanoimprint lithography, as a key process in the fabrication of micro- and nanostructures, has been widely applied in the preparation of optical thin films, display panels, precision optical molds, and semiconductor micro- and nanostructures, including substrates with functional textures such as anti-fouling and anti-reflection properties. Currently, the UV-curable coating materials widely used in nanoimprint lithography are mainly based on common acrylate or general-purpose epoxy resin systems. However, with the increasing demands on the precision, durability, and mass production stability of micro- and nanostructures in various applications, existing materials are gradually revealing many shortcomings.

[0003] First, conventional resin coatings have high surface energy, resulting in poor anti-fouling and spunbond properties. During the imprinting and demolding process, they are prone to defects such as mold sticking, structural defects, and texture distortion, significantly shortening mold life and severely impacting process consistency and production efficiency. Second, fluorinated modified components introduced to improve demolding performance are often simple, readable structures or added through physical blending. These components have poor compatibility with the base resin, easily leading to phase separation. This results in decreased surface smoothness of the cured micro / nanostructure and insufficient wear resistance and weather resistance, making it difficult to meet long-term reliability requirements. Third, traditional free-radical UV-curable resin systems are significantly affected by oxygen inhibition, leading to incomplete curing in shaded areas or thick films, and low crosslinking density, resulting in deterioration of the dimensional stability and replication fidelity of micro / nanostructures. Although epoxy-modified perfluoropolyether materials have been applied in the field of protective coatings, nitrogen is mainly used for general surface protection requirements and has not yet been systematically adapted for nanoimprinting processes to achieve low viscosity, high leveling properties, high demolding performance, and high structural fidelity. In addition, existing nano-silica modified embossing coatings still have the following problems: conventional modified silica is mostly prepared using short-chain coupling agents, resulting in insufficient flexibility of the system and concentration of internal stress. The microstructures obtained by embossing are prone to edge chipping or cracking. At the same time, in order to ensure the uniformity of particle dispersion, small molecule dispersants are usually introduced. These components do not participate in curing and cross-linking and remain inside the coating. This not only reduces the accuracy of microstructure replication, but also has an adverse effect on the coating's temperature resistance, wear resistance and demolding stability, making it difficult to meet the requirements of high hardness and high durability in nano-embossing.

[0004] Therefore, existing nanoimprinted UV-curable coating materials still have significant limitations in terms of release performance, structural fidelity, curing uniformity, and long-term reliability, and new material systems are urgently needed to solve these problems. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a nanoimprinted UV-curable coating composition, its preparation method, and its application, thus solving the problems mentioned in the background section.

[0006] To achieve the above objectives, the present invention provides the following technical solution: According to a first aspect of the present invention, a nanoimprint UV-curable coating composition is provided, comprising, by weight, 10-20 parts of a bifunctional epoxy-terminated perfluoropolyether oligomer, 70-85 parts of an alicyclic epoxy reactive diluent, 3-5 parts of a cationic photoinitiator, 0.1-0.5 parts of a leveling agent, 0.1-0.3 parts of an antifoaming agent, and 1-5 parts of modified silica, wherein the modified silica is cyclohexyl alicyclic epoxy silane coupling agent modified silica.

[0007] This invention uses a bifunctional epoxy-terminated perfluoropolyether oligomer as the matrix resin, combining the advantages of cationic UV curing with oxygen-free polymerization inhibition and low curing shrinkage, and adjusting the amount of epoxy reactive diluent in the replacement group to form a low-viscosity formulation system. This achieves a nano-imprinted micro / nano structure coating with low-temperature rapid curing, high structural fidelity, easy demolding, high wear resistance, and ultra-low surface energy. In addition, this application uses a cyclohexyl alicyclic epoxy silane coupling agent to modify silica. Compared with the traditional short-chain KH560 modification system, the long-chain flexible alkyl segment can effectively buffer the curing internal stress, and the terminal epoxy group can chemically bond with the epoxy group in the system. This not only completely solves the nanoparticle aggregation defect, but also constructs a composite structure of "rigid nanocore + flexible long-chain bridge", which greatly improves the deformation resistance, surface hardness, wear resistance and smoothness of imprinting and demolding of the micro / nano structure.

[0008] Preferably, the bifunctional epoxy-terminated perfluoropolyether oligomer has an epoxy end-capping rate of ≥90%, a fluorine content of ≥60%, a color of <50 Hazen, and a viscosity at room temperature of 800~1200 mPa·s.

[0009] Preferably, the cyclohexyl alicyclic epoxy silane coupling agent is selected from 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane.

[0010] Preferably, the particle size of the modified silica is 20~80nm.

[0011] Preferably, the alicyclic epoxy reactive diluent is selected from 4,5-epoxyhexane-1,2-dicarboxylic acid diglycidyl ester; The cationic photoinitiator is selected from at least one of diphenyl-(4-phenylthio)phenylsulfonium hexafluorophosphate and diphenyl-(4-phenylthio)phenylsulfonium hexafluoroantimonate; The leveling agent is selected from at least one of BYK355 and BYK349; The defoaming agent is selected from at least one of BYK1799 and BYK024.

[0012] According to a second aspect of the present invention, a method for preparing a nanoimprint UV-curable coating composition is provided, comprising the following steps: uniformly mixing a bifunctional epoxy-terminated perfluoropolyether oligomer, an alicyclic epoxy reactive diluent, a cationic photoinitiator, a leveling agent, an antifoaming agent, and modified silica, and degassing to obtain the UV-curable coating composition.

[0013] Preferably, the bifunctional epoxy-terminated perfluoropolyether oligomer is prepared by the following method: S1. Under a nitrogen atmosphere, epichlorohydrin, fluorinated liquid and tetrabutylammonium bromide are stirred evenly, and then double-hydroxyl-terminated perfluoropolyether is added to obtain a reaction system, wherein the number average molecular weight of the double-hydroxyl-terminated perfluoropolyether is 1000~2000 and the hydroxyl value is 40~80mgKOH / g. S2. Add sodium hydroxide aqueous solution dropwise to the reaction system at 45~55℃. After the addition is complete, first carry out the ring-opening reaction, and then raise the temperature to carry out the ring-closing reaction to obtain the reaction solution. S3. Cool the reaction solution to room temperature, allow it to stand and separate into layers, remove the lower organic phase, wash it, and remove the fluorinated liquid under vacuum to obtain the bifunctional epoxy-terminated perfluoropolyether oligomer.

[0014] In the preparation of bifunctional epoxy-terminated perfluoropolyether oligomers, the amount of epichlorohydrin needs to be excessive to ensure that the two hydroxyl groups of the bifunctional perfluoropolyether are fully closed to form epoxy groups. However, if the amount is too high, the residual epichlorohydrin will be difficult to remove, affecting the stability of the coating curing. Therefore, the molar ratio of the bifunctional perfluoropolyether to the epichlorohydrin is preferably 1:2.4~3.0. Tetrabutylammonium bromide is used as a phase transfer catalyst. If the amount is too low, the reaction conversion efficiency will be too low due to the poor mass transfer between the fluorine phase and the aqueous phase. If the amount is too high, the residual quaternary ammonium salt will neutralize the cationic photo-acidification, reducing the coating curing efficiency. Therefore, the mass of the tetrabutylammonium bromide is preferably a fraction of that of the bifunctional perfluoropolyether. 1.5~3.5wt%; The fluorinated liquid, as a solvent, mainly serves to reduce the viscosity of the system and improve the uniformity of the two-phase reaction. If the amount of fluorinated liquid is too small, the material will become viscous, resulting in incomplete reaction. If the amount of fluorinated liquid is too large, the desolvation process will be significantly prolonged. Therefore, the mass of the fluorinated liquid is preferably 180~300wt% of the double-hydroxyl-terminated perfluoropolyether. The addition of sodium hydroxide aqueous solution mainly provides alkaline conditions to achieve hydroxyl deprotonation and epoxy ring closure. If the amount of alkali added is insufficient, the ring closure conversion rate will be low. If the amount of alkali added is excessive, it will easily cause epoxy side ring opening, and the epoxy equivalent of the product will decrease. Therefore, the amount of sodium hydroxide aqueous solution added is preferably 12~25wt% of the double-hydroxyl-terminated perfluoropolyether.

[0015] Preferably, the ring-opening reaction is carried out at a temperature of 45-55°C for 3-4 hours. The closed-loop reaction is carried out at a temperature of 70-75°C for 4-5 hours.

[0016] Specifically, the preparation method of the bifunctional epoxy-terminated perfluoropolyether oligomer is as follows: Step 1: Place the hydroxyl-terminated perfluoropolyether in a vacuum drying oven and dry it at 80°C and -0.0095MPa for 2 hours to remove moisture and small molecule impurities. Control the moisture content of the system to <500ppm to avoid epoxy hydrolysis and deactivation. The number average molecular weight of the hydroxyl-terminated perfluoropolyether is 1000~2000 and the hydroxyl value is 40~80mgKOH / g. Step 2: Under a nitrogen atmosphere, epichlorohydrin, fluorinated liquid, and tetrabutylammonium bromide are added to a four-necked reaction flask and stirred until homogeneous. Then, a double-hydroxyl-terminated perfluoropolyether is added to obtain a homogeneous reaction system. Step 3: Heat the reaction system to 45~55℃, slowly add 50% sodium hydroxide aqueous solution, and after 1.5h of addition, perform a ring-closing reaction for 3~4h, then heat to 70~75℃ to perform a ring-opening reaction for 4~5h to obtain the reaction solution; Step 4: After the reaction is complete, let the reaction solution stand and separate into layers. Take the lower organic phase and wash it 3-4 times with deionized water, then wash it once with saturated saline solution until neutral. Finally, remove the fluorinated liquid, residual epichlorohydrin and small molecule impurities under vacuum at 80°C to obtain a colorless and transparent bifunctional epoxy-terminated polyether oligomer.

[0017] According to a third aspect of the present invention, an application is provided of a nanoimprinted UV-curable coating composition or a nanoimprinted UV-curable coating composition obtained according to the above preparation method in nanostructure coatings.

[0018] Specifically, the preparation method of the nano-microstructure coating is as follows: The substrate is ultrasonically cleaned sequentially with ethanol and deionized water, and then dried to remove surface oil and dust. The substrate is selected from optical glass, PET film, silicon wafer or mold steel substrate. The nanoimprinted UV-curable coating composition is uniformly coated onto the substrate surface by spin coating, slot coating or spraying, with a wet film thickness of 5~20μm, and self-leveling is achieved by standing at room temperature for 30s. Nanoimprint bonding is performed by applying a pressure of 0.2~0.5MPa to the coating surface, followed by single-sided UV irradiation with a curing energy of 800~1200mJ / cm². 2 It can be cured rapidly at room temperature, without oxygen inhibition, and the micro-nano structure can be completely cured deep inside. After curing, the material is demolded at a uniform speed and then baked at a low temperature of 60℃ for 20 minutes for secondary curing to obtain a nano-microstructure coating.

[0019] This invention provides a nanoimprinted UV-curable coating composition, its preparation method, and its application. It possesses the following beneficial effects: This solution provides a nanoimprint UV-curable coating composition, which introduces a bifunctional epoxy-terminated perfluoropolyether oligomer and a cyclohexyl alicyclic epoxy silane coupling agent-modified silica. During the crosslinking process of the bifunctional epoxy-terminated perfluoropolyether oligomer, the cyclohexyl alicyclic rings of the cyclohexyl alicyclic epoxy silane coupling agent-modified silica are cured and embedded at the crosslinking points with high-density alicyclic rings, thereby improving the network packing density and extrusion resistance at the molecular level. At the same time, during the curing process, the cyclohexyl alicyclic epoxy silane coupling agent, the bifunctional epoxy-terminated perfluoropolyether oligomer, and the alicyclic epoxy reactive diluent undergo a simultaneous epoxy ring-opening copolymerization reaction, enabling the inorganic nanoparticles and resin to be integrated and crosslinked through organic covalent bonds. This significantly improves the coating's hardness, wear resistance, and the stability of the micro / nano structure size, avoiding edge chipping and internal stress concentration problems.

[0020] This solution provides a nanoimprint UV-curable coating composition that uses a cyclohexyl alicyclic epoxy silane coupling agent to modify silica. High-density long alkyl chains are grafted onto the silica surface, forming sufficient steric hindrance around the silica. This allows the silica particles to be uniformly and stably dispersed without the need for external small molecule dispersants. This avoids the decrease in crosslinking density and microstructure defects caused by traditional dispersant residues, while ensuring the high cleanliness and high crosslinking integrity of the coating.

[0021] This solution provides a nanoimprint UV-curable coating composition in which bifunctional epoxy-terminated perfluoropolyether oligomers, alicyclic epoxy reactive diluents, and cyclohexyl alicyclic epoxy silane coupling agents modify silica to undergo simultaneous ring-opening polymerization during cationic curing, forming an integrated network with fully covalent bonds. This eliminates inorganic-organic interface defects, enabling the coating to achieve a coating strength of 0, and also possessing resistance to acids and alkalis and UV aging.

[0022] This solution provides a nano-microstructure coating with a nanostructure replication fidelity of over 99.5%, free from defects, deformation, and sticking. It has a water contact angle ≥140°, a coating hardness ≥60HD, and exhibits no scratches after 1500 cycles of steel wool abrasion testing. It also has an adhesion rating of 0 and is resistant to acid and alkali corrosion and UV aging. Attached Figure Description

[0023] Figure 1 The images shown are test images of the micro-nano structure coating prepared in Example 1 of the present invention. Among them, Figure A is a SEM image of the micro-nano structure coating at 1 μm, Figure B is a SEM image of the micro-nano structure coating at 200 nm, Figure C is a water contact angle test image, and Figure D is a cross-cut adhesion test image after 1000 rubs. Figure 2The images shown are test images of the micro-nano structure coating prepared in Example 2 of the present invention. Among them, Figure A is a SEM image of the micro-nano structure coating at 200 nm, Figure B is a SEM image of the micro-nano structure coating at 200 nm, Figure C is a water contact angle test image, and Figure D is a cross-cut adhesion test image after 800 rubs. Figure 3 The images shown are test images of the micro-nano structure coating prepared in Comparative Example 1 of the present invention. In the images, A is a SEM image of the micro-nano structure coating at 1 μm, B is a SEM image of the micro-nano structure coating at 1 μm, C is a water contact angle test image, and D is a cross-cut adhesion test image after 500 rubs. Figure 4 The images shown are test images of the micro-nano structure coating prepared in Comparative Example 2 of the present invention. In the images, A is a SEM image of the micro-nano structure coating at 1 μm, B is a SEM image of the micro-nano structure coating at 1 μm, C is a water contact angle test image, and D is a cross-cut adhesion test image after 300 rubs. Figure 5 The chart shows a comparison of the Young's modulus of the micro / nano structure coatings prepared in Examples 1-2 and Comparative Examples 1-2. Detailed Implementation

[0024] To better illustrate the content of this invention, the following description is provided in conjunction with specific embodiments.

[0025] The bifunctional epoxy-terminated perfluoropolyether oligomers used in the following embodiments and comparative examples of this invention were prepared by the following methods: Step 1: Dry the double-hydroxyl-terminated perfluoropolyether (Fluorolink D, number average molecular weight 1000~2000, hydroxyl value 40~80mgKOH / g) under vacuum at 80℃ and -0.0095MPa for 2h to obtain dry double-hydroxyl-terminated perfluoropolyether with moisture content <500ppm. Step 2: Under a nitrogen atmosphere, add 28.0g of epichlorohydrin, 220.0g of fluorinated liquid solution and 2.4g of tetrabutylammonium bromide to a four-necked reaction flask and stir until homogeneous. Then add 100.0g of dry double-hydroxyl-terminated perfluoropolyether to obtain a homogeneous reaction system. Step 3: Heat the homogeneous reaction system to 50°C, add 18.0g of 50% sodium hydroxide aqueous solution dropwise to the reaction system, add dropwise for 1.5h, after the addition is complete, react at 50°C for 3h to open the ring, and then heat to 75°C to close the ring for 4h to obtain the reaction solution. Step 4: Cool the reaction solution to room temperature, allow it to stand and separate into layers, remove the lower organic phase, wash it four times with deionized water and once with saturated saline solution until neutral, and finally remove the fluorinated liquid, residual epichlorohydrin and small molecule impurities under vacuum at 80°C. Filter to obtain a colorless and transparent bifunctional epoxy-terminated perfluoropolyether oligomer. The epoxy terminology is 94.2%, the fluorine content is 62.5%, the color is 36 Hazen, and the viscosity at room temperature is 820 mPa·s.

[0026] The method for preparing the modified silica in this invention is as follows: Silica particles with a particle size of 20~80nm were first dried in an oven at 120℃ for 2h to remove adsorbed water and impurities. Then, 100g of dried silica particles were reacted with 4g of cyclohexyl alicyclic epoxy silane coupling agent (commercial model SiSiB PC3500) at room temperature for 1.5h. Finally, the mixture was centrifuged at low speed and washed with fluorinated liquid to obtain modified silica.

[0027] The following detailed description, in conjunction with specific embodiments and comparative examples, illustrates a nanoimprinted UV-curable coating composition, its preparation method, and its application provided by the present invention. Example

[0028] The specific preparation method of a nano-microstructure coating provided in this embodiment is as follows: Step 1: By weight, mix 15 parts of bifunctional epoxy-terminated perfluoropolyether oligomer, 78.5 parts of alicyclic epoxy diluent (specifically, 4,5-epoxyhexane-1,2-dicarboxylic acid diglycidyl ester, model TDE85), 5 parts of modified nano silica, 3.5 parts of thionium salt initiator (specifically, diphenyl-(4-phenylthio)phenylsulfonium hexafluorophosphate, model UVI-6976), 0.3 parts of leveling aid (model BYK349), and 0.2 parts of defoaming aid (specifically, silicone defoamer, model BYK1799) evenly, degas, and obtain a UV-curable coating composition; Step 2: The optical glass is ultrasonically cleaned sequentially with ethanol and deionized water, and dried to remove surface oil and dust. A UV-curable coating composition is then applied to the optical glass surface using spin coating, achieving a wet film thickness of 10 μm. Nano-pressing is performed at a pressure of 0.3 MPa, followed by pressing with 1000 mJ / cm². 2 After being cured by UV light irradiation on one side, the material is demolded and then baked at 60℃ for 20 minutes to obtain a micro-nano structure coating.

[0029] according to Figure 1It can be seen that the micro-nano structure coating prepared in this embodiment has a structural fidelity of 99.6%, a water contact angle of 148.7°, a hardness of 75HD, is resistant to wear without scratches after 1000 cycles, has strong structural rigidity, and is dimensionally stable. Example

[0030] The preparation method of this embodiment is the same as that of Example 1, except that the UV-curable coating composition, by weight, includes 15 parts of a bifunctional epoxy-terminated perfluoropolyether oligomer, 82.5 parts of an alicyclic epoxy diluent (specifically, 4,5-epoxyhexane-1,2-dicarboxylic acid diglycidyl ester, model TDE85), 1 part of modified nano-silica, 3.5 parts of a thioonium salt initiator (specifically, diphenyl-(4-phenylthio)phenylsulfonium hexafluoroantimonate, model UVI-6976), 0.3 parts of a leveling aid (model BYK349), and 0.2 parts of an antifoaming aid (specifically, an organosilicon antifoaming agent, model BYK1799).

[0031] according to Figure 2 As shown, the micro-nano structure coating prepared in this embodiment has a structural fidelity of 99.5%, a water contact angle of 145.5°, a hardness of 63HD, is scratch-resistant after 800 wear cycles, and demolds smoothly.

[0032] Comparative Example 1 The preparation method of this comparative example is the same as that of Example 1, except that the UV-curable coating composition, by weight, includes 15 parts of a bifunctional epoxy-terminated perfluoropolyether oligomer, 78.5 parts of an alicyclic epoxy diluent (specifically, the alicyclic epoxy reactive diluent is selected from 4,5-epoxyhexane-1,2-dicarboxylic acid diglycidyl ester), 5 parts of KH-560 modified silica, 3.5 parts of a thionium salt initiator (specifically, diphenyl-(4-phenylthio)phenylsulfonium hexafluorophosphate, model UVI-6976), 0.3 parts of a leveling aid (model BYK349), and 0.2 parts of an antifoaming aid (specifically, an organosilicon antifoaming agent, model BYK1799).

[0033] according to Figure 3 As shown, the structural fidelity of the micro-nano structure coating prepared in this embodiment is only 96.4, the structure has irregular protrusions, the water contact angle is 115.3°, and scratches appear on the surface after 500 rubs. This indicates that replacing the modified silica in Example 1 with KH-560 modified nano silica will result in slight particle agglomeration in the system, local edge chipping of the imprinted micro-nano structure, high curing internal stress, and reduced overall performance.

[0034] Comparative Example 2 The preparation method of this comparative example is the same as that of Example 2, except that the UV-curable coating composition, by weight, includes 15 parts of a bifunctional epoxy-terminated perfluoropolyether oligomer, 82.5 parts of an alicyclic epoxy diluent (specifically, 4,5-epoxyhexane-1,2-dicarboxylic acid diglycidyl ester, model TDE85), 1 part of KH-560 modified nano silica, 3.5 parts of a thioonium salt initiator (specifically, diphenyl-(4-phenylthio)phenylsulfonium hexafluoroantimonate, model UVI-6976), 0.3 parts of a leveling aid (model BYK349), and 0.2 parts of a defoaming aid (specifically, an organosilicon defoamer, model BYK1799).

[0035] according to Figure 4 It can be seen that the micro-nano structure has local edge chipping, the water contact angle is only 92.1°, scratches appear after 300 rubs, and the structural fidelity is only 93.2%.

[0036] according to Figure 5 It can be seen that the Young's modulus of the micro-nano structure coatings prepared in Examples 1 and 2 is better than that of the micro-nano structure coatings in Comparative Examples 1 and 2, indicating that modifying silica with cyclohexyl alicyclic epoxy silane coupling agent can also improve the deformation resistance of the micro-nano structure coating and make the structure of the prepared micro-nano structure coating more stable.

[0037] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A nanoimprinted UV-curable coating composition, characterized in that: By weight, it comprises 10-20 parts of a bifunctional epoxy-terminated perfluoropolyether oligomer, 70-85 parts of an alicyclic epoxy reactive diluent, 3-5 parts of a cationic photoinitiator, 0.1-0.5 parts of a leveling agent, 0.1-0.3 parts of a defoaming agent, and 1-5 parts of modified silica, wherein the modified silica is cyclohexyl alicyclic epoxy silane coupling agent modified silica.

2. The nanoimprint UV-curable coating composition according to claim 1, characterized in that: The bifunctional epoxy-terminated perfluoropolyether oligomer has an epoxy end-capping rate of ≥90%, a fluorine content of ≥60%, a color of <50 Hazen, and a viscosity of 800~1200 mPa·s at room temperature.

3. The nanoimprint UV-curable coating composition according to claim 1, characterized in that: The cyclohexyl alicyclic epoxy silane coupling agent is 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane.

4. The nanoimprint UV-curable coating composition according to claim 1, characterized in that: The modified silica has a particle size of 20~80nm.

5. The nanoimprint UV-curable coating composition according to claim 1, characterized in that: The alicyclic epoxy reactive diluent is selected from 4,5-epoxyhexane-1,2-dicarboxylic acid diglycidyl ester; The cationic photoinitiator is selected from at least one of diphenyl-(4-phenylthio)phenylsulfonium hexafluorophosphate and diphenyl-(4-phenylthio)phenylsulfonium hexafluoroantimonate; The leveling agent is selected from at least one of BYK355 and BYK349; The defoaming agent is selected from at least one of BYK1799 and BYK024.

6. A method for preparing the nanoimprinted UV-curable coating composition according to any one of claims 1 to 5, characterized in that: The bifunctional epoxy-terminated perfluoropolyether oligomer, alicyclic epoxy reactive diluent, cationic photoinitiator, leveling agent, defoaming agent and modified silica are mixed evenly and defoamed to obtain the UV-curable coating composition.

7. The method for preparing a nanoimprinted UV-curable coating composition according to claim 6, characterized in that: The bifunctional epoxy-terminated perfluoropolyether oligomer was prepared by the following method: S1. Under a nitrogen atmosphere, epichlorohydrin, fluorinated liquid and tetrabutylammonium bromide are stirred evenly, and then double-hydroxyl-terminated perfluoropolyether is added to obtain a reaction system, wherein the number average molecular weight of the double-hydroxyl-terminated perfluoropolyether is 1000~2000 and the hydroxyl value is 40~80mgKOH / g. S2. Add sodium hydroxide aqueous solution dropwise to the reaction system at 45~55℃. After the addition is complete, first carry out the ring-opening reaction, and then raise the temperature to carry out the ring-closing reaction to obtain the reaction solution. S3. Cool the reaction solution to room temperature, allow it to stand and separate into layers, remove the lower organic phase, wash it, and remove the fluorinated liquid under vacuum to obtain the bifunctional epoxy-terminated perfluoropolyether oligomer.

8. The method for preparing a nanoimprinted UV-curable coating composition according to claim 7, characterized in that: The molar ratio of the hydroxyl-terminated perfluoropolyether to the epichlorohydrin is 1:2.4~3.0; The mass of the tetrabutylammonium bromide is 1.5~3.5 wt% of the double-hydroxyl-terminated perfluoropolyether; The mass of the fluorinated liquid is 180~300wt% of the double-hydroxyl-terminated perfluoropolyether; The amount of sodium hydroxide aqueous solution added is 12-25 wt% of the double-hydroxyl-terminated perfluoropolyether.

9. The method for preparing a nanoimprinted UV-curable coating composition according to claim 7, characterized in that: The ring-opening reaction is carried out at a temperature of 45-55°C for 3-4 hours. The closed-loop reaction is carried out at a temperature of 70-75°C for 4-5 hours.

10. The application of a nanoimprinted UV-curable coating composition prepared according to claims 1 to 5 or a nanoimprinted UV-curable coating composition obtained by the preparation method according to any one of claims 6 to 9 in nanostructure coatings.

Images