Super-hydrophobic anti-fingerprint coating for mobile phone screen

Abstract

The invention relates to the technical field of coating materials, and discloses a super-hydrophobic anti-fingerprint coating for a mobile phone screen, which is prepared from the following raw materials in parts by mass: 45 to 55 parts of hydrophobic fluorosilicone resin, 2 to 3 parts of ultraviolet absorbent, 0.5 to 1.5 parts of light stabilizer, 3 to 3.5 parts of modified carbon nanofiber, 0.4 to 0.8 part of silane coupling agent, 1.5 to 2 parts of photoinitiator and 40 to 45 parts of mixed solvent. According to the prepared super-hydrophobic anti-fingerprint coating for the mobile phone screen, the coating is endowed with excellent super-hydrophobic and anti-fingerprint performance by virtue of the synergistic effect of all the raw material components and precise modification and preparation process design, adhesion of stains such as fingerprints and the like on the surface of the screen can be effectively reduced, and the stains are easy to wipe and clean; and the cleanliness of the screen can still be kept after long-term use.

Description

Technical Field

[0001] This invention relates to the field of coating materials technology, and specifically to a superhydrophobic anti-fingerprint coating for mobile phone screens. Background Technology

[0002] In the field of coating materials technology, hydrophobic anti-fingerprint coatings for mobile phone screens are key materials for improving the user experience and screen protection capabilities of mobile phones. However, the preparation and application of existing coatings still face many unresolved issues. Traditional hydrophobic anti-fingerprint coatings for mobile phone screens often employ physical doping to introduce UV absorbers and light stabilizers. These additives do not form a strong bond with the resin substrate and are prone to migration and precipitation during long-term use, leading to a rapid decline in the coating's UV protection and light stability, poor weather resistance and anti-aging performance, and problems such as yellowing and performance degradation, thus limiting its lifespan. The reinforcing fillers used in existing coatings are mostly unmodified or simply modified nanomaterials with poor dispersion in the resin, making it difficult to form a stable reinforcing structure. This not only fails to effectively improve the mechanical properties and scratch resistance of the coating but may also affect the film-forming properties and surface smoothness. Furthermore, the hydrophobic modification effect of the fillers is poor, making it difficult to form a synergistic effect with the hydrophobic resin. Therefore, the improvement in the superhydrophobicity and anti-fingerprint properties of the coating is limited, and fingerprint stains still easily adhere and are difficult to clean. Meanwhile, traditional coatings have poor compatibility between their components and insufficient adhesion to the glass substrate, making them prone to peeling and flaking during daily use. Furthermore, some coatings have demanding manufacturing processes with poor parameter controllability, resulting in inconsistent overall performance and difficulty in ensuring performance stability. This makes it impossible to meet the comprehensive requirements of mobile phone screens for coatings in terms of hydrophobicity, fingerprint resistance, mechanical properties, weather resistance, and adhesion.

[0003] Based on this, this application provides a superhydrophobic anti-fingerprint coating for mobile phone screens. Summary of the Invention

[0004] Technical problems to be solved To address the shortcomings of existing technologies, this invention provides a superhydrophobic anti-fingerprint coating for mobile phone screens.

[0005] Technical solution To achieve the above objectives, the present invention provides the following technical solution: A superhydrophobic anti-fingerprint coating for mobile phone screens comprises the following raw materials in parts by weight: 45-55 parts hydrophobic fluorosilicone resin, 2-3 parts ultraviolet absorber, 0.5-1.5 parts light stabilizer, 3-3.5 parts modified carbon nanofiber, 0.4-0.8 parts silane coupling agent, 1.5-2 parts photoinitiator, and 40-45 parts mixed solvent.

[0006] Furthermore, the mixed solvent is a solution obtained by mixing butyl acetate and propylene glycol methyl ether acetate in a volume ratio of 3:2.

[0007] Furthermore, the ultraviolet absorber is specifically prepared by the following steps: The UV absorber and triethylamine were added to anhydrous dichloromethane, stirred to dissolve, and placed in an ice-water bath at a constant temperature. Acryloyl chloride was added dropwise to the system, and then the temperature was raised to room temperature and the reaction was continued with stirring for 100-120 min. After the reaction was completed, the triethylamine hydrochloride precipitate was removed by filtration, the filtrate was washed until neutral, dried with anhydrous sodium sulfate, and the solvent was removed by vacuum distillation to obtain the UV absorber.

[0008] Furthermore, the ultraviolet absorber is specifically prepared by the following steps: The UV absorber and triethylamine were added to anhydrous dichloromethane, stirred to dissolve, and placed in an ice-water bath at 0-5℃ for constant temperature. Acryloyl chloride was added dropwise to the system, and the addition was completed within 1.0-1.5 hours. After the addition was completed, the temperature was raised to room temperature and the reaction was stirred for 120 minutes. After the reaction was completed, the triethylamine hydrochloride precipitate was removed by vacuum filtration. The filtrate was washed once with 5wt% sodium bicarbonate solution and then washed with saturated sodium chloride aqueous solution until neutral. After drying with anhydrous sodium sulfate for 4 hours, the solvent was removed by vacuum distillation at 45℃ to obtain the UV absorber.

[0009] Furthermore, the ultraviolet absorbing raw material is 2-hydroxy-4-methoxybenzophenone (hereinafter referred to as UV531).

[0010] Furthermore, the molar ratio of the ultraviolet absorbing material, triethylamine, and acryloyl chloride is (0.05-0.15):(0.1-0.2):(0.1-0.15).

[0011] Furthermore, the light stabilizer is specifically prepared by the following steps: The light stabilizer and triethylamine were dissolved in anhydrous dichloromethane and cooled to 0-5°C. Acryloyl chloride was then added dropwise to the system, and the reaction was continued to be stirred at room temperature. The salt precipitate was removed by filtration, and the organic phase was washed, dried, and desolvated under reduced pressure to obtain the light stabilizer.

[0012] Furthermore, the light stabilizer is specifically prepared by the following steps: The light stabilizer and triethylamine were dissolved in anhydrous dichloromethane and cooled to a constant temperature of 0-5°C in an ice-water bath. Acryloyl chloride was then added dropwise to the system, with the addition completed within 45 minutes. The reaction was continued with stirring at room temperature. The salt precipitate was removed by filtration, and the organic phase was subjected to the same washing, drying, and desolvation steps as described above to obtain the light stabilizer.

[0013] Furthermore, the light-stabilizing raw material is 4-hydroxy-2,2,6,6-tetramethylpiperidine.

[0014] Further, the molar ratio of the light-stabilizing raw material, triethylamine and acryloyl chloride is (0.05-0.15):(0.1-0.15):(0.05-0.15).

[0015] In the above technical solution, triethylamine and acryloyl chloride are used to modify the light-stabilizing raw material and the ultraviolet-absorbing raw material, respectively. This allows components that could only be physically doped to covalently copolymerize with fluorosilicone acrylic resin, ensuring that the components do not migrate or precipitate in the coating and are covalently anchored to the resin backbone. Acryloyl chloride provides polymerizable acrylate double bonds and simultaneously grafts double bonds through nucleophilic substitution reactions between the acryl chloride groups and the hydroxyl groups on the two raw materials. The nitrogen atom of triethylamine has a lone pair of electrons, which can form weak hydrogen bonds with the hydrogen atoms of the hydroxyl groups in the molecule, increasing the electron cloud density of the oxygen atoms of the hydroxyl groups and enhancing their nucleophilicity. This accelerates the reaction rate with the acryloyl chloride acryl chloride groups, achieving efficient modification at room temperature and avoiding damage to the core structure of the light-stabilizing components at high temperatures. At the same time, triethylamine acts as an acid-binding agent, capturing the hydrogen chloride generated in the reaction to form triethylamine hydrochloride precipitate, further promoting the reaction.

[0016] Furthermore, the modified carbon nanofibers are specifically prepared by the following steps: A1. Disperse carbon nanofibers in nitric acid solution, sonicate the dispersion, heat the resulting suspension in an oil bath under reflux, and stir magnetically throughout the process; after reflux, cool to room temperature, centrifuge and wash with deionized water until the pH of the supernatant is neutral, and vacuum dry to obtain carboxylated carbon nanofibers. A2. Disperse carboxylated carbon nanofibers in anhydrous methanol and sonicate until completely suspended. Add perfluorooctyltrimethoxysilane and stir magnetically at room temperature for 16-24 h. Then heat to 120-130℃ and stir in an oil bath for 1-2 h. After the reaction is complete, cool to room temperature, wash with anhydrous ethanol by centrifugation, and vacuum dry to obtain modified carbon nanofibers.

[0017] Furthermore, in step A1, the concentration of the nitric acid solution used is 4-6 mol / L, and the mass-to-volume ratio of carbon nanofibers to nitric acid solution is (50-150) mg:150 mL.

[0018] Further, in step A2, the mass ratio of the carboxylated carbon nanofibers to perfluorooctyltrimethoxysilane is (0.1-0.3):(5-7).

[0019] Furthermore, the preparation method of the superhydrophobic anti-fingerprint coating for the mobile phone screen specifically includes the following steps: Step 1: Add the modified carbon nanofibers and silane coupling agent according to the formula to the mixed solvent, disperse the system ultrasonically, then place it in a water bath at 40-60℃ and stir. Cool to room temperature to obtain a modified carbon nanofiber dispersion for later use. Add the hydrophobic fluorosilicone resin and the mixed solvent to the reaction vessel and stir until transparent and free of particles. Add the ultraviolet absorber and light stabilizer in sequence, and continue stirring for 10-20 minutes after each addition to obtain a resin mixture. Step 2: Add the modified carbon nanofiber dispersion dropwise to the resin mixture and disperse at a low speed of 1000-1500 rpm for 20-30 minutes. Then, disperse by ultrasonication to obtain a uniform composite dispersion system. Under light-protected conditions, add a photoinitiator to the composite dispersion system, stir and filter, and store in a sealed, light-protected container to obtain a superhydrophobic anti-fingerprint coating for mobile phone screens.

[0020] Furthermore, the preparation method of the superhydrophobic anti-fingerprint coating for the mobile phone screen specifically includes the following steps: Add the modified carbon nanofibers and silane coupling agent according to the formula to the mixed solvent, and ultrasonically disperse the system at 300-400W and 20-40KHz for 30-40 minutes. Then place it in a 50℃ water bath and stir at low speed for 1 hour. Cool to room temperature to obtain the modified carbon nanofiber dispersion for later use. Hydrophobic fluorosilicone resin and mixed solvent were added to a reaction vessel and stirred at low speed until transparent and free of particles. UV absorber and light stabilizer were added in sequence, and stirring at low speed was continued for 15 minutes after each addition to obtain resin mixture. The modified carbon nanofiber dispersion was added dropwise to the resin mixture at a rate of 5 mL / min. After the addition was completed, it was dispersed at a low speed of 1200 rpm for 30 min, and then ultrasonically dispersed at 300 W and 40 kHz for 20 min to obtain a uniform composite dispersion system. Under light-protected conditions, a photoinitiator is added to the composite dispersion system and stirred at low speed for 30 minutes. Subsequently, a small amount of undispersed particles are removed by filtration, and the system is sealed and stored in the dark at a temperature below 25°C to obtain a superhydrophobic anti-fingerprint coating for mobile phone screens.

[0021] Furthermore, the filtration specifically involves sequential coarse filtration through a 0.8μm PTFE membrane and fine vacuum filtration through a 0.45μm PTFE membrane.

[0022] Furthermore, the photoinitiator is specifically photoinitiator 1173.

[0023] Beneficial technical effects In this invention, the covalent grafting modification of ultraviolet-absorbing and light-stabilizing raw materials anchors the two types of additives onto the resin backbone, avoiding the migration and precipitation problems associated with traditional physical doping methods. This allows the coating to possess long-lasting ultraviolet absorption and light stabilization capabilities, significantly improving its weather resistance and anti-aging performance, and extending its service life. The superhydrophobic and anti-fingerprint coating for mobile phone screens prepared by this invention, relying on the synergistic effect of each raw material component and precise modification and preparation process design, endows the coating with excellent superhydrophobic and anti-fingerprint properties. It can effectively reduce the adhesion of fingerprints and other stains to the screen surface, and the stains are easy to wipe clean, maintaining screen cleanliness even after long-term use.

[0024] In the technical solution of this invention, carbon nanofibers modified in two steps form a stable reinforcing skeleton in the coating, which not only further enhances the hydrophobic properties of the coating, but also effectively improves the mechanical properties and scratch resistance of the coating, making it suitable for the contact and friction scenarios in daily use of mobile phone screens.

[0025] In this invention, the introduction of a silane coupling agent optimizes the compatibility and bonding strength between the components, enabling the coating to form a strong bond with the mobile phone screen glass substrate. This results in excellent adhesion and reduces the likelihood of peeling or flaking. Furthermore, the entire coating preparation process is characterized by mild conditions, highly controllable parameters at each step, and excellent raw material dispersion. The resulting coating exhibits good film-forming properties, a smooth and uniform surface, superior overall performance, and strong stability, perfectly meeting the requirements of mobile phone screens and demonstrating significant practical application value. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only some embodiments of the present invention, 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.

[0027] The hydrophobic fluorosilicone resin used in this invention is manufactured by Weihai Xinyuan Chemical Co., Ltd., and its trade name is FAS-Si; UV531: industrial grade, purity ≥99%. 4-Hydroxy-2,2,6,6-Tetramethylpiperidine: industrial grade, purity ≥98%. Carbon nanofibers: diameter 10-20 nm, length 50-200 μm. Perfluorooctyltrimethoxysilane: industrial grade, purity ≥97%. Photoinitiator, specifically photoinitiator 1173, purity ≥99%.

[0028] In a specific implementation, the vacuum degree of the vacuum filtration is -0.06 MPa, and the relative humidity of the sealed storage environment is ≤60%. The vacuum degree of the vacuum distillation is -0.09 MPa.

[0029] Modified carbon nanofibers are provided in Examples 1-3 below.

[0030] Example 1 Modified carbon nanofibers are prepared by the following steps: A1. Disperse 80 mg of carbon nanofibers in 150 mL of 4 mol / L nitric acid solution and sonicate for 10 min. Heat the resulting suspension in an oil bath at 120 °C and reflux for 24 h with magnetic stirring at 300 rpm throughout. After reflux, cool to room temperature, wash with deionized water until the pH of the supernatant is 7, set the speed to 8000 rpm, 10 min each time, and vacuum dry at 90 °C for 12 h to obtain carboxylated carbon nanofibers. A2. Disperse 0.15g of the above carboxylated carbon nanofibers in 40mL of anhydrous methanol and sonicate for 20min until completely suspended; add 5.0g of perfluorooctyltrimethoxysilane and stir magnetically at room temperature for 18h; heat to 130℃ and stir in an oil bath for 1.5h; after the reaction is complete, cool to room temperature, wash three times with anhydrous ethanol by centrifugation at 8000rpm for 10min each time to remove unreacted fluorosilane monomers, and vacuum dry at 80℃ for 10h to obtain modified carbon nanofibers.

[0031] Example 2 Modified carbon nanofibers are prepared by the following steps: A1. 100 mg of carbon nanofibers were dispersed in 150 mL of 6 mol / L nitric acid solution and ultrasonically dispersed for 10 min. The resulting suspension was heated and refluxed in an oil bath at 120 °C for 24 h with magnetic stirring at 300 rpm throughout. After reflux, the suspension was cooled to room temperature and washed with deionized water until the pH of the supernatant was 7. The centrifugation speed was set to 8000 rpm for 10 min each time. The suspension was then vacuum dried at 90 °C for 12 h to obtain carboxylated carbon nanofibers. A2. Disperse 0.2g of the above carboxylated carbon nanofibers in 40mL of anhydrous methanol and sonicate for 20min until completely suspended; add 6.0g of perfluorooctyltrimethoxysilane (FOTS) and stir magnetically at room temperature for 18h; heat to 130℃ and stir in an oil bath for 1.5h; after the reaction is complete, cool to room temperature, wash three times with anhydrous ethanol by centrifugation at 8000rpm for 10min each time to remove unreacted fluorosilane monomers, and vacuum dry at 80℃ for 10h to obtain modified carbon nanofibers.

[0032] Example 3 Modified carbon nanofibers are prepared by the following steps: A1. 120 mg of carbon nanofibers were dispersed in 150 mL of 6 mol / L nitric acid solution and ultrasonically dispersed for 10 min. The resulting suspension was heated and refluxed in an oil bath at 120 °C for 24 h with magnetic stirring at 300 rpm throughout. After reflux, the suspension was cooled to room temperature and washed with deionized water until the pH of the supernatant was 7. The centrifugation speed was set to 8000 rpm for 10 min each time. The suspension was then vacuum dried at 90 °C for 12 h to obtain carboxylated carbon nanofibers. A2. Disperse 0.25g of the above carboxylated carbon nanofibers in 40mL of anhydrous methanol and sonicate for 20min until completely suspended; add 6.0g of perfluorooctyltrimethoxysilane and stir magnetically at room temperature for 18h; heat to 130℃ and stir in an oil bath for 1.5h; after the reaction is complete, cool to room temperature, wash three times with anhydrous ethanol by centrifugation at 8000rpm for 10min each time to remove unreacted fluorosilane monomers, and dry under vacuum at 80℃ for 10h to obtain modified carbon nanofibers.

[0033] The following Examples 4-6 provide a superhydrophobic anti-fingerprint coating for mobile phone screens.

[0034] Example 4 A superhydrophobic anti-fingerprint coating for mobile phone screens comprises the following raw materials in parts by weight: 45 parts hydrophobic fluorosilicone resin, 2 parts ultraviolet absorber, 0.5 parts light stabilizer, 3 parts modified carbon nanofibers prepared in Example 1, 0.4 parts silane coupling agent, 1.5 parts photoinitiator, and 40 parts mixed solvent; The hydrophobic fluorosilicone resin used is FAS-Si; the silane coupling agent is KH-570; and the mixed solvent is a solution obtained by mixing butyl acetate and propylene glycol methyl ether acetate in a volume ratio of 3:2. The ultraviolet absorber is prepared by the following steps: 0.05 mol of UV absorber and 0.1 mol of triethylamine were added to 200 mL of anhydrous dichloromethane, stirred to dissolve, and placed in an ice-water bath at 0-5°C for constant temperature. 0.1 mol of acryloyl chloride was added dropwise to the system, and the addition was completed within 1.0 h. After the addition was completed, the temperature was raised to room temperature and the reaction was continued with stirring for 120 min. After the reaction was completed, the triethylamine hydrochloride precipitate was removed by filtration. The filtrate was washed once with 5 wt% sodium bicarbonate solution and then washed with saturated sodium chloride aqueous solution until neutral. After drying with anhydrous sodium sulfate for 4 h, the solvent was removed by vacuum distillation at 45°C to obtain the UV absorber. The UV absorber was UV531.

[0035] The light stabilizer is prepared by the following steps: 0.05 mol of the light-stabilizing raw material and 0.1 mol of triethylamine were dissolved in 180 mL of anhydrous dichloromethane and cooled to a constant temperature of 0-5°C in an ice-water bath. Then, 0.05 mol of acryloyl chloride was added dropwise to the system, completing the addition within 45 min, and the reaction was continued with stirring at room temperature. The salt precipitate was removed by filtration, and the organic phase was subjected to the same washing, drying, and desolvation steps as described above to obtain the light stabilizer. The light-stabilizing raw material was 4-hydroxy-2,2,6,6-tetramethylpiperidine.

[0036] Its preparation method specifically includes the following steps: Step 1: Add the modified carbon nanofibers and silane coupling agent according to the formula to the mixed solvent. Disperse the system ultrasonically at 300W and 20KHz for 30 minutes, then place it in a 50℃ water bath and stir at a low speed of 300rpm for 1 hour. Cool to room temperature to obtain the modified carbon nanofiber dispersion for later use. Add the hydrophobic fluorosilicone resin and the mixed solvent to the reaction vessel and stir at a low speed of 400rpm until it is transparent and free of particles. Add the UV absorber and light stabilizer in sequence, and continue stirring at a low speed for 15 minutes after addition to obtain the resin mixture. Step 2: Add the modified carbon nanofiber dispersion dropwise to the resin mixture at a rate of 5 mL / min. After addition, disperse at 1200 rpm for 30 min, and then ultrasonically disperse at 300 W and 40 kHz for 20 min to obtain a uniform composite dispersion system. Under light-protected conditions, add a photoinitiator to the composite dispersion system and stir at low speed for 30 min until completely dissolved. Subsequently, filter to remove a small amount of undispersed particles, seal and store in a light-protected environment below 25°C to obtain a superhydrophobic anti-fingerprint coating for mobile phone screens. Specifically, the filtration involves sequential coarse filtration through a 0.8 μm PTFE membrane and fine vacuum filtration through a 0.45 μm PTFE membrane.

[0037] Example 5 The difference between this embodiment and embodiment 4 is that the superhydrophobic anti-fingerprint coating for the mobile phone screen in this embodiment includes the following raw materials in parts by weight: 50 parts hydrophobic fluorosilicone resin, 2.5 parts ultraviolet absorber, 1.0 part light stabilizer, 3.2 parts modified carbon nanofibers prepared in Example 2, 0.6 parts silane coupling agent, 1.8 parts photoinitiator, and 43 parts mixed solvent; The hydrophobic fluorosilicone resin used is FAS-Si; the silane coupling agent is KH-570; and the mixed solvent is a solution obtained by mixing butyl acetate and propylene glycol methyl ether acetate in a volume ratio of 3:2. The ultraviolet absorber is prepared by the following steps: 0.1 mol of UV absorber and 0.14 mol of triethylamine were added to 200 mL of anhydrous dichloromethane, stirred to dissolve, and placed in an ice-water bath at 0-5°C for constant temperature. 0.12 mol of acryloyl chloride was added dropwise to the system over 1.0-1.5 h. After the addition was complete, the temperature was raised to room temperature and the reaction was stirred for 120 min. After the reaction was completed, the triethylamine hydrochloride precipitate was removed by filtration. The filtrate was washed once with 5 wt% sodium bicarbonate solution and then washed with saturated sodium chloride aqueous solution until neutral. After drying with anhydrous sodium sulfate for 4 h, the solvent was removed by vacuum distillation at 45°C to obtain the UV absorber. The UV absorber was UV531.

[0038] The light stabilizer is prepared by the following steps: 0.1 mol of the light-stabilizing raw material and 0.12 mol of triethylamine were dissolved in 180 mL of anhydrous dichloromethane and cooled to a constant temperature of 0-5°C in an ice-water bath. Then, 0.11 mol of acryloyl chloride was added dropwise to the system, completing the addition within 45 min, and the reaction was continued with stirring at room temperature. The salt precipitate was removed by filtration, and the organic phase was subjected to the same washing, drying, and desolvation steps as described above to obtain the light stabilizer. The light-stabilizing raw material was 4-hydroxy-2,2,6,6-tetramethylpiperidine.

[0039] Example 6 The difference between this embodiment and embodiment 4 is that the superhydrophobic anti-fingerprint coating for the mobile phone screen in this embodiment includes the following raw materials in parts by weight: 55 parts hydrophobic fluorosilicone resin, 3 parts ultraviolet absorber, 1.5 parts light stabilizer, 3.5 parts modified carbon nanofibers prepared in Example 3, 0.8 parts silane coupling agent, 2 parts photoinitiator, and 45 parts mixed solvent; The hydrophobic fluorosilicone resin used is FAS-Si; the silane coupling agent is KH-570; and the mixed solvent is a solution obtained by mixing butyl acetate and propylene glycol methyl ether acetate in a volume ratio of 3:2. The ultraviolet absorber is prepared by the following steps: 0.15 mol of UV absorber and 0.2 mol of triethylamine were added to 200 mL of anhydrous dichloromethane, stirred to dissolve, and placed in an ice-water bath at 0-5°C for constant temperature. 0.15 mol of acryloyl chloride was added dropwise to the system over 1.0-1.5 h. After the addition was complete, the temperature was raised to room temperature and the reaction was stirred for 120 min. After the reaction was completed, the triethylamine hydrochloride precipitate was removed by filtration. The filtrate was washed once with 5 wt% sodium bicarbonate solution and then washed with saturated sodium chloride aqueous solution until neutral. After drying with anhydrous sodium sulfate for 4 h, the solvent was removed by vacuum distillation at 45°C to obtain the UV absorber. The UV absorber was UV531.

[0040] The light stabilizer is prepared by the following steps: 0.15 mol of the light-stabilizing raw material and 0.15 mol of triethylamine were dissolved in 180 mL of anhydrous dichloromethane and cooled to a constant temperature of 0-5°C in an ice-water bath. Then, 0.15 mol of acryloyl chloride was added dropwise to the system, completing the addition within 45 min, and the reaction was continued with stirring at room temperature. The salt precipitate was removed by filtration, and the organic phase was subjected to the same washing, drying, and desolvation steps as described above to obtain the light stabilizer; the light-stabilizing raw material was 4-hydroxy-2,2,6,6-tetramethylpiperidine.

[0041] Comparative Example 1 The difference between this comparative example and Example 5 is that an ultraviolet absorbing material is used instead of an ultraviolet absorber, that is, an equal mass of UV351 is used instead of an ultraviolet absorber.

[0042] Comparative Example 2 The difference between this comparative example and Example 5 is that a light-stabilizing raw material is used instead of a light stabilizer, that is, UV5301 is used instead of a light stabilizer.

[0043] Comparative Example 3 The difference between this comparative example and Example 5 is that the modified carbon nanofibers obtained in Example 2 are replaced with an equal mass of original carbon nanofibers and directly added to the mixed solvent. The remaining steps are the same as in Example 5.

[0044] The coating materials prepared in the examples and comparative examples are now subjected to performance tests. The specific test methods are as follows: The prepared coating materials from different groups were spin-coated onto clean soda-lime glass substrates to simulate mobile phone screen glass. The spin-coating parameters were 5000 rpm × 30 s, followed by 5 min at room temperature for leveling. The leveled coatings were then dried in a 60℃ forced-air drying oven for 10 min to remove the mixed solvents. Subsequently, they were cured in a mercury lamp UV curing machine with the following curing parameters: wavelength 365 nm, light intensity 800 mW / cm². 2 The curing time is 30 seconds, and the entire process is protected by a nitrogen atmosphere to prevent yellowing and oxidation of the coating surface. After curing, the coating is placed in an environment with a room temperature of 25°C and a humidity of 50% for 24 hours to cure. Then, the following performance tests are performed.

[0045] Water contact angle test: The seated drop method was used, and the test was conducted at room temperature (25°C) using a contact angle meter. The volume of the deionized water droplet was 5 μL. Five different test points were selected for each sample, and the average value was taken. The required product contact angle is ≥150°.

[0046] Fingerprint residue test: Press an artificial finger with 5N pressure for 3 seconds, capture the image with an image acquisition device, and calculate the percentage of the residue area using image analysis software. Take the average value of 3 tests.

[0047] Coating mechanical hardness test: Refer to the method described in GB / T6739-2006 "Determination of hardness of paint film by pencil method for paints and varnishes", set the test parameters as 1000g load, 45° included angle, 5 tests, and take the highest grade of no scratch.

[0048] Abrasion resistance test: Using a Taber abrasion tester and a CS-10 grinding wheel, the abrasion was performed for 500 revolutions under a 500g load. The water contact angle retention rate after abrasion was calculated as (contact angle after abrasion / original contact angle × 100%).

[0049] The specific test results are shown in Table 1 below: Table 1

[0050] As shown in Table 1, the samples in Examples 4-6 exhibited better performance. Example 5 had the highest water contact angle, the best superhydrophobic properties, the best fingerprint resistance, and the highest contact angle retention rate after wear resistance among all examples. Example 6 was the upper limit ratio, and its performance was slightly lower than that of Example 5, indicating that excessively increasing the proportion of raw materials could not further improve performance, but instead increased the viscosity of the coating liquid, affecting the coating film formation.

[0051] Comparative Examples 1 and 2, due to the physical doping of light-stabilizing / UV-absorbing additives, could form a film after curing, but the additives did not participate in the covalent cross-linking of the resin and were only dispersed in the film, resulting in a decrease in coating performance. The unmodified carbon nanofibers in the comparative example showed a water contact angle of only 135° after coating curing, and also decreased fingerprint residue, pencil hardness, and abrasion resistance retention. This is because the original carbon nanofibers lack hydrophobic groups and have poor dispersion in the cross-linked film, failing to form a hydrophobic framework and only slightly improving mechanical properties.

[0052] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0053] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has 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 the present invention.

[0054] Those skilled in the art should understand that the above descriptions are merely several specific embodiments of the present invention, and not all embodiments.

Claims

1. A superhydrophobic anti-fingerprint coating for mobile phone screens, characterized in that, Includes the following quantities of raw materials: 45-55 parts hydrophobic fluorosilicone resin, 2-3 parts ultraviolet absorber, 0.5-1.5 parts light stabilizer, 3-3.5 parts modified carbon nanofiber, 0.4-0.8 parts silane coupling agent, 1.5-2 parts photoinitiator, and 40-45 parts mixed solvent.

2. The superhydrophobic anti-fingerprint coating for mobile phone screens according to claim 1, characterized in that, The ultraviolet absorber is specifically prepared by the following steps: The UV absorber and triethylamine were added to anhydrous dichloromethane, stirred to dissolve, and placed in an ice-water bath at a constant temperature. Acryloyl chloride was added dropwise to the system, and then the temperature was raised to room temperature and the reaction was continued with stirring for 100-120 min. After the reaction was completed, the triethylamine hydrochloride precipitate was removed by filtration, the filtrate was washed until neutral, dried with anhydrous sodium sulfate, and the solvent was removed by vacuum distillation to obtain the UV absorber.

3. The superhydrophobic anti-fingerprint coating for mobile phone screens according to claim 2, characterized in that, The molar ratio of the UV-absorbing raw material, triethylamine, and acryloyl chloride is (0.05-0.15):(0.1-0.2):(0.1-0.15).

4. The superhydrophobic anti-fingerprint coating for mobile phone screens according to claim 1, characterized in that, The light stabilizer is prepared by the following steps: The light stabilizer and triethylamine were dissolved in anhydrous dichloromethane and cooled to 0-5°C. Acryloyl chloride was then added dropwise to the system, and the reaction was continued to be stirred at room temperature. The salt precipitate was removed by filtration, and the organic phase was washed, dried, and desolvated under reduced pressure to obtain the light stabilizer.

5. The superhydrophobic anti-fingerprint coating for mobile phone screens according to claim 4, characterized in that, The molar ratio of the light-stabilizing raw material, triethylamine, and acryloyl chloride is (0.05-0.15):(0.1-0.15):(0.05-0.15).

6. The superhydrophobic anti-fingerprint coating for mobile phone screens according to claim 1, characterized in that, The modified carbon nanofibers are specifically prepared by the following steps: A1. Disperse carbon nanofibers in nitric acid solution, sonicate the dispersion, heat the resulting suspension in an oil bath under reflux, and stir magnetically throughout the process; after reflux, cool to room temperature, centrifuge and wash with deionized water until the pH of the supernatant is neutral, and vacuum dry to obtain carboxylated carbon nanofibers. A2. Disperse carboxylated carbon nanofibers in anhydrous methanol and sonicate until completely suspended. Add perfluorooctyltrimethoxysilane and stir magnetically at room temperature for 16-24 h. Then heat to 120-130℃ and stir in an oil bath for 1-2 h. After the reaction is complete, cool to room temperature, wash with anhydrous ethanol by centrifugation, and vacuum dry to obtain modified carbon nanofibers.

7. The superhydrophobic anti-fingerprint coating for mobile phone screens according to claim 6, characterized in that, In step A1, the concentration of the nitric acid solution used is 4-6 mol / L, and the mass-to-volume ratio of carbon nanofibers to nitric acid solution is (50-150) mg:150 mL.

8. The superhydrophobic anti-fingerprint coating for mobile phone screens according to claim 6, characterized in that, In step A2, the mass ratio of the carboxylated carbon nanofibers to perfluorooctyltrimethoxysilane is (0.1-0.3):(5-7).

9. The superhydrophobic anti-fingerprint coating for mobile phone screens according to claim 1, characterized in that, Its preparation method specifically includes the following steps: Step 1: Add the modified carbon nanofibers and silane coupling agent according to the formula to the mixed solvent, disperse the system ultrasonically, then place it in a water bath at 40-60℃ and stir. Cool to room temperature to obtain a modified carbon nanofiber dispersion for later use. Add the hydrophobic fluorosilicone resin and the mixed solvent to the reaction vessel and stir until transparent and free of particles. Add the ultraviolet absorber and light stabilizer in sequence, and continue stirring for 10-20 minutes after each addition to obtain a resin mixture. Step 2: Add the modified carbon nanofiber dispersion dropwise to the resin mixture and disperse at a low speed of 1000-1500 rpm for 20-30 minutes. Then, disperse by ultrasonication to obtain a uniform composite dispersion system. Under light-protected conditions, add a photoinitiator to the composite dispersion system, stir and filter, and store in a sealed, light-protected container to obtain a superhydrophobic anti-fingerprint coating for mobile phone screens.

10. A superhydrophobic anti-fingerprint coating for mobile phone screens according to claim 9, characterized in that, The filtration process specifically involves sequential coarse filtration through a 0.8μm PTFE membrane and fine vacuum filtration through a 0.45μm PTFE membrane.

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