Anti-fingerprint electronic product shell and preparation method thereof

Abstract

The invention discloses an anti-fingerprint electronic product shell and a preparation method thereof, and relates to the technical field of anti-fingerprint coatings, and the process comprises the following steps: mixing light-cured resin, a reactive diluent, nanoparticles, a photoinitiator and an auxiliary agent to obtain an anti-fingerprint coating; spraying and photocuring are performed to form an anti-fingerprint coating, and the electronic product shell is obtained. The light-cured resin comprises epoxy modified acrylate resin; the epoxy modified acrylate resin is prepared by reacting an acrylate monomer, epoxidized organic silicon and glycidyl methacrylate. Organic silicon and fluorine chain segments are introduced into a polymer cross-linked network in a chemical bonding mode, and a lasting and stable low-surface-energy basis is provided for a coating. Surface-modified nano SiO2 particles and chitin-based hybrid resin are utilized and are tightly combined with a resin matrix through chemical bonds, a stable micro-nano coarse structure is constructed in the coating, excellent hydrophobic and oleophobic properties are achieved, and the prepared coating can show more excellent fingerprint resistance.

Description

Technical Field

[0001] This invention relates to the field of anti-fingerprint coating technology, specifically to an anti-fingerprint electronic product casing and its preparation method. Background Technology

[0002] The back cover of electronic products such as mobile phones and tablets is the surface that users perceive most directly and frequently. When users hold the device, the back cover becomes sticky and slippery with fingerprints, affecting the user experience and the product's appearance. Sweat and sebum contain moisture, inorganic salts, and fatty acids, which can corrode the device surface over time. Fingerprints also detract from the product's texture. For user experience, device protection, and commercial value, the industry generally adopts a solution of coating the casing with an anti-fingerprint coating. Currently, mainstream anti-fingerprint coating technologies mainly rely on two types of substances: fluorinated compounds and organosilicon compounds. These substances effectively reduce the surface energy of the coating, giving it a certain degree of hydrophobic and oleophobic properties, thus achieving anti-fingerprint and easy-to-clean effects.

[0003] However, existing anti-fingerprint coating technologies still have many unresolved issues: anti-fingerprint coatings rely on physically blended small-molecule fluorinated or silicone additives. These additives have weak adhesion to the resin matrix and are easily migrated and washed away during use due to friction, wiping, or sweat, leading to rapid degradation of anti-fingerprint performance and a short lifespan. To achieve good anti-fingerprint effects, a large amount of low surface energy components needs to be introduced, but this often sacrifices the adhesion between the coating and the substrate, as well as the hardness of the coating itself. Coatings with poor adhesion are prone to peeling and flaking; while coatings with low hardness are not scratch-resistant and cannot meet the stringent requirements of daily use of electronic products. Therefore, we propose an anti-fingerprint electronic product casing and its preparation method. Summary of the Invention

[0004] The purpose of this invention is to provide an anti-fingerprint electronic product casing and its preparation method, so as to solve the problems mentioned in the background art.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: an anti-fingerprint electronic product casing, comprising a substrate and an anti-fingerprint coating disposed on the surface of the substrate.

[0006] Furthermore, the anti-fingerprint coating is formed by spraying anti-fingerprint paint onto the substrate surface, followed by drying and curing.

[0007] Furthermore, after the anti-fingerprint coating is sprayed and cured, it is subjected to CNC (computer numerical control) precision cutting and forming to obtain an electronic product casing with high dimensional accuracy and smooth edges.

[0008] A method for preparing an anti-fingerprint electronic product casing includes the following processes: A mixture of photocurable resin, reactive diluent, nanoparticles, photoinitiator, and additives is prepared and dispersed to obtain an anti-fingerprint coating. The coating is sprayed onto the substrate surface and then photocured to form an anti-fingerprint coating, resulting in the casing of electronic products.

[0009] Furthermore, the anti-fingerprint coating comprises the following components by weight: 65-100 parts of photocurable resin, 15-25 parts of reactive diluent, 2-5 parts of nanoparticles, 3-6 parts of photoinitiator, and 0.7-2.5 parts of additives.

[0010] Furthermore, the photocurable resin comprises the following components by weight: 30-40 parts epoxy-modified acrylate resin, 20-30 parts epoxy acrylate, 10-20 parts polyurethane acrylate, and 5-10 parts hybrid resin.

[0011] Epoxy acrylates cure quickly, providing basic adhesion and hardness as a framework, and exhibiting good affinity with the substrate. The urethane bonds in the polyurethane acrylate molecular chain can form strong intermolecular hydrogen bonds, effectively absorbing and dispersing stress, endowing the coating with excellent wear resistance, high elasticity, and impact toughness, balancing the system's brittleness. The hybrid resin is an organic-inorganic hybrid resin; the nanoscale inorganic phase enhances the nano-reinforcement effect, thereby improving the coating's hardness and barrier properties; polar functional groups act as molecular anchors, enhancing interfacial adhesion; simultaneously, they construct microscopic roughness, synergistically improving anti-fingerprint performance.

[0012] Furthermore, the reactive diluent includes hydroxyethyl acrylate, tripropylene glycol diacrylate, and isobornyl acrylate in a mass ratio of 2:5:1.5.

[0013] Hydroxyethyl acrylate contains hydroxyl groups, which can improve adhesion to polar substrates and participate in hydrogen bonding networks. Tripropylene glycol diacrylate is a low-viscosity, high-dilution-efficiency bifunctional monomer that provides crosslinking density and balances hardness and flexibility. Isoborneol acrylate contains a large alicyclic structure, which can effectively reduce curing shrinkage, improve coating adhesion to the substrate, and enhance hydrophobicity.

[0014] Furthermore, the photocuring process is as follows: leveling at 50–60°C for 2–5 minutes; UV irradiation for 2–5 seconds under nitrogen protection, with a dominant wavelength of 365 nm and a light energy of 800–1200 mJ / cm². 2 .

[0015] Furthermore, the photoinitiator is a compound of photoinitiator 1173, photoinitiator TPO, and EDAB, with a mass ratio of 1.5:1.0:0.8.

[0016] Furthermore, the additives are 0.5 to 1.2 parts wetting and dispersing agent, 0.1 to 0.3 parts leveling agent, and 0.1 to 0.2 parts defoamer.

[0017] Furthermore, the thickness of the anti-fingerprint coating is between 8 and 20 μm.

[0018] Furthermore, the epoxy-modified acrylate resin is prepared by the following process: The acrylate monomer and the initiator were mixed in propylene glycol methyl ether acetate and polymerized at 70-80°C for 4-6 hours to obtain a copolymer solution. Add epoxidized organosilicon and triethylamine, heat to 90-100℃, and react for 3-5 hours; cool to 65-70℃, add glycidyl methacrylate and polymerization inhibitor, and react for 2-3 hours. After the reaction was completed, the temperature was lowered to <35℃ and distilled under reduced pressure to obtain epoxy-modified acrylate resin.

[0019] Furthermore, the epoxy-modified acrylate resin comprises the following components by weight: 80-100 parts acrylate monomer, 25-35 parts epoxidized organosilicon, 0.6-0.8 parts initiator azobisisobutyronitrile, 0.5-1.0 parts triethylamine, 5-8 parts glycidyl methacrylate, 0.04-0.08 parts polymerization inhibitor hydroquinone, and 50 parts propylene glycol methyl ether acetate.

[0020] The acrylate monomers include the following components by weight: 35-40 parts butyl acrylate, 20-25 parts methyl methacrylate, 5-8 parts acrylic acid, 8-10 parts hydroxyethyl acrylate, 2-3 parts N-hydroxymethylacrylamide, and 1-5 parts octadecyl acrylate.

[0021] In the above technical solution, the molecular structure design of the epoxy-modified acrylate resin achieves the molecular-level introduction of organosilicon and the suspension of UV-curable functional groups. Acrylate monomers and initiators are dissolved in a solvent, and free radical copolymerization forms a main chain with various reactive functional groups and flexible / rigid segments, resulting in a copolymer solution containing carboxyl, hydroxyl, amide, and long-chain alkyl groups, providing sites for subsequent modification. Epoxidized organosilicon and triethylamine are added to the copolymer solution, and the reaction is heated. The carboxyl groups on the copolymer side chains undergo ring-opening esterification with the epoxy groups of the epoxidized organosilicon, forming stable Si-OC bonds, thereby chemically grafting flexible, hydrophobic organosilicon segments onto the polymer main chain in the form of side chains. Cooling is then performed, and glycidyl methacrylate is added to react. The remaining hydroxyl groups on the copolymer undergo ring-opening etherification with the epoxy groups of GMA, grafting highly reactive methacryloyloxy groups onto the molecular chain ends or side chains, endowing the resin with excellent UV curing ability.

[0022] Furthermore, epoxidized organosilicon is prepared by the following process: Polyether-modified silicone oil, maleic anhydride, 4-dimethylaminopyridine and hydroquinone were mixed and heated to 70-80°C under nitrogen protection, and stirred for 4-5 hours to obtain an organosilicon intermediate. Add epoxy resin and triphenylphosphine, heat to 100-110℃, and continue the reaction for 3-4 hours to obtain epoxidized organosilicon.

[0023] Furthermore, the epoxidized organosilicon comprises the following components by weight: 100 parts polyether-modified silicone oil, 8-12 parts maleic anhydride, 0.1-0.2 parts 4-dimethylaminopyridine, 0.02-0.05 parts hydroquinone, 30-45 parts epoxy resin, and 0.3-0.6 parts triphenylphosphine.

[0024] In the above technical solution, the anhydride group of maleic anhydride undergoes an esterification reaction with the hydroxyl group at the end of the polyether modified silicone oil to generate a carboxyl-containing organosilicon intermediate; the carboxyl group generated in the previous step undergoes a ring-opening esterification reaction with the epoxy group of the epoxy resin, thereby attaching the epoxy resin segment to the organosilicon molecule to obtain epoxidized organosilicon.

[0025] Furthermore, the polyether-modified silicone oil is prepared by the following process: A solution of n-butyllithium in n-hexane was added to trifluoropropylmethylcyclotrisiloxane and tetrahydrofuran under a nitrogen atmosphere at 0–5 °C, and the mixture was stirred for 4–6 h. Finally, dimethylchlorosilane was added, and the reaction was continued for 1–2 h. The mixture was then centrifuged and rotary evaporated to obtain a fluorosilicone compound. In a nitrogen atmosphere, a fluorosilicone compound and a cassiterite catalyst are mixed in anhydrous toluene, heated to 40–50 °C, and then allyl polyoxyethylene polyoxypropylene ether is added. The temperature is then raised to 75–80 °C, and the reaction is carried out for 10–12 h. After the reaction, the mixture is distilled under reduced pressure to obtain polyether-modified silicone oil.

[0026] Furthermore, the molar ratio of trifluoropropylmethylcyclotrisiloxane, dimethylchlorosilane, and n-butyllithium is 10:(1-5):(0.1-0.2). The amount of tetrahydrofuran is 1.5 to 3.0 times the volume of trifluoropropylmethylcyclotrisiloxane; The concentration of the n-butyllithium n-hexane solution is 1.6–2.0 mol / L; Furthermore, the molar ratio of the silane-hydrogen bond in the fluorosilicone compound, the carbon-carbon double bond in the allyl polyoxyethylene polyoxypropylene ether, and the catalyst (calculated as Pt) is 100:(105-115):(0.001-0.010). The mass ratio of fluorosilicone compound to anhydrous toluene is 1: (0.8 to 1.5).

[0027] In the above technical solution, trifluoropropylmethylcyclotrisiloxane undergoes ring-opening polymerization, and dimethylchlorosilane is used for end-capping to form a fluorosiloxane oligomer. The Si-H bonds provide reaction sites for subsequent hydrosilylation, and this is denoted as a fluorosilicone compound. Under the action of a platinum catalyst, the Si-H bonds in the fluorosilicone compound undergo hydrosilylation with the double bonds of the allyl polyether, grafting hydrophilic polyether segments onto the oleophobic fluorosilicone framework. The final product simultaneously possesses the flexibility and low surface energy of organosilicon, the oleophobicity of fluorocarbons, and the hydrophilicity and compatibility of polyethers, making it a key precursor for constructing high-performance coatings.

[0028] Furthermore, the hybrid resin is prepared by the following process: Chitosan was dispersed in an ethanol / water mixture, and glacial acetic acid was added to adjust the pH to 4–5; KH-570 was added, and the mixture was stirred at 60–65°C for 4–6 h; tetraethyl orthosilicate was added to adjust the pH to 8–9, and the mixture was stirred at room temperature for 12–24 h. After the reaction was completed, the mixture was centrifuged, washed, redispersed, dried, and ground until the particle size D50 < 5 μm to obtain the hybrid resin.

[0029] Furthermore, the hybrid resin comprises the following components by weight: 10 parts chitosan, 3 to 5 parts KH-570 (γ-(meth)acryloyloxypropyltrimethoxysilane), and 2.5 to 3.5 parts tetraethyl orthosilicate.

[0030] In the above technical solution, KH-570 hydrolyzes to generate silanol, which undergoes a condensation reaction with the surface-active groups of chitin, grafting methacryloyloxy groups onto the chitin surface. TEOS hydrolyzes and condenses to generate nano-SiO2 particles. These particles further condense with the KH-570 silanol grafted onto the chitin through Si-O-Si bonds, forming organic-inorganic hybrid particles with chitin as the core, surface-grafted polymer, and encapsulated SiO2. The polar groups abundant in chitin can form strong hydrogen bonds and van der Waals forces with the substrate surface, effectively improving the adhesion of the coating to the substrate; at the same time, it imparts rigidity and toughness to the coating, balancing brittleness and flexibility. The in-situ generated nano-SiO2 is uniformly distributed in the hybrid resin, effectively improving the overall hardness, wear resistance, and density of the coating. The hybrid particles form nanoscale physical protrusions in the coating, working synergistically with the nanoparticles to construct the micro-nano structure required for fingerprint resistance. Chitosan's hybrid framework helps to fix and disperse the aforementioned particles and nanoparticles, preventing excessive aggregation or sedimentation, thus achieving a more uniform, stable, and durable retention on the coating surface. The methacryloyloxy groups on its surface participate in the UV curing reaction, forming strong chemical bonds between the particles and the resin matrix, preventing detachment and performance degradation. Furthermore, through the rigid framework of the hybrid resin, the strong organic-inorganic interfacial bonding, the elastic buffering of the flexible chains, and the pre-structured network structure, it helps to disperse concentrated stress, prevent interfacial debonding, absorb and dissipate strain energy, maintain the UV-cured volume of the coating, reduce shrinkage during the final curing stage, promote dimensional stability, improve coating leveling and appearance, and enhance toughness, impact resistance, and hardness retention.

[0031] Furthermore, the nanoparticles are one or more of nano-SiO2, nano-Al2O3, and nano-ZrO2.

[0032] The nanoparticles are modified by coupling with fluorinated siloxanes; the fluorinated segments provide low surface energy for the coating, and the nanoparticles have a rough texture, thus achieving hydrophobic and oleophobic effects. During the coating curing process, some of these low surface energy modified nanoparticles migrate to the surface and, together with hybrid resins in the resin matrix, construct a micro-nano composite rough structure. This structure greatly reduces the actual contact area between oil stains and fingerprint secretions and the coating surface, making them easier to roll off or wipe away.

[0033] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention introduces organosilicon and fluorine segments into a polymer crosslinking network through chemical bonding, providing a durable and stable low surface energy basis for the coating. Utilizing surface-modified nano-SiO2 particles and chitin-based hybrid resin, and tightly bonded to the resin matrix through chemical bonds, a stable micro-nano rough structure is constructed in the coating, achieving excellent hydrophobic and oleophobic properties. The resulting coating exhibits superior anti-fingerprint capabilities.

[0034] 2. This invention ensures strong adhesion of the coating to various substrates through the anchoring effect of multifunctional resins and hybrid resins, and the coordination of reactive diluents. Functional components (such as organosilicon, fluorocarbon chains, and nanoparticles) are connected to the cross-linking network through chemical bonds, avoiding performance degradation caused by the migration and precipitation of small molecule additives, resulting in a long service life. The combination of rigidity and flexibility in the resin system, along with the nano-reinforcing phase, enables the coating to simultaneously possess high hardness, high adhesion, good toughness, and wear resistance, meeting the stringent requirements of daily use of electronic product casings. Detailed Implementation

[0035] 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.

[0036] Unless otherwise specified, all "parts" mentioned below refer to parts by weight. The manufacturers of all raw materials involved in this invention are not subject to any special restrictions. Exemplary examples include: allyl polyoxyethylene polyoxypropylene ether: average molar mass 1100 g / mol; epoxy resin: E-44; commercially available epoxy-terminated silicone oil: Shin-Etsu KF-101; commercially available polyether-modified silicone oil: hydroxyl-terminated polyether-modified silicone oil, Mn=2000; wetting and dispersing agent BYK-110, leveling agent BYK-361N, defoamer BYK-051; caster catalyst: platinum metal content 3000 ppm, soluble in xylene; epoxy acrylate: Zhanxin EBECRYL605; polyurethane acrylate: Changxing Chemical ETERCURE6148J-75; concentration of n-butyllithium n-hexane solution is 1.6 mol / L; chitin: α-type, derived from Aladdin; in the ethanol / water mixture, the volume ratio of ethanol to water is 3:1; the ratio of chitin to ethanol / water mixture is 10 g / 500 mL; The reactive diluents include hydroxyethyl acrylate, tripropylene glycol diacrylate, and isobornyl acrylate in a mass ratio of 2:5:1.5; the photoinitiator is a compound of photoinitiator 1173, TPO, and EDAB in a mass ratio of 1.5:1.0:0.8. The modified nanoparticles are perfluorooctyltriethoxysilane-coupled modified nanoparticles. The specific process is as follows (which can be scaled up): 10g of nanoparticles are dispersed in 500mL of anhydrous toluene, 3g of perfluorooctyltriethoxysilane and 1g of water (pH=5) are added, and the mixture is reacted at reflux temperature of 110℃ for 6h; after the reaction, the nanoparticles are centrifuged, washed, dried, and ground. The preparation process of KH-570-coupled modified nanoparticles is the same as above. The nanoparticles are nano-SiO2, nano-Al2O3, and nano-ZrO2 in a mass ratio of 5:2:1, with D50=50nm, and are coupled in steps during modification. The substrate was prepared according to Example 1 of patent CN118849592; the thickness of the anti-fingerprint coating was 15 μm.

[0037] Example 1: A method for preparing an anti-fingerprint electronic product casing, comprising the following processes: Step 1: A solution of n-butyllithium in n-hexane was added to trifluoropropylmethylcyclotrisiloxane and 1.5 times its volume (compared to the volume of trifluoropropylmethylcyclotrisiloxane, the same below) of tetrahydrofuran under a nitrogen atmosphere and at 0°C. The mixture was stirred for 4 hours. Finally, dimethylchlorosilane was added, and the reaction was continued for 1 hour. The mixture was centrifuged and rotary evaporated to obtain a fluorosilicone compound. Under a nitrogen atmosphere, the fluorosilicone compound and a caster catalyst were reacted in a mixture of 0.8 times its mass (compared to the mass of the fluorosilicone compound, the same below) of... The mixture was stirred in anhydrous toluene and heated to 40°C. Allyl polyoxyethylene polyoxypropylene ether was added, and the temperature was raised to 75°C. The reaction was carried out for 10 hours. After the reaction, the mixture was distilled under reduced pressure to obtain polyether-modified silicone oil. The molar ratio of trifluoropropylmethylcyclotrisiloxane, dimethylchlorosilane, and n-butyllithium was 10:1:0.1. The molar ratio of silane-hydrogen bonds in the fluorosilicone compound, carbon-carbon double bonds in the allyl polyoxyethylene polyoxypropylene ether, and catalyst (calculated as Pt) was 100:105:0.001. 100 parts of polyether-modified silicone oil, 8 parts of maleic anhydride, 0.1 parts of 4-dimethylaminopyridine and 0.02 parts of hydroquinone were mixed and heated to 70°C under nitrogen protection, and stirred for 5 hours to obtain an organosilicon intermediate; 30 parts of epoxy resin and 0.3 parts of triphenylphosphine were added and mixed, and the mixture was heated to 100°C and reacted for another 4 hours to obtain epoxidized organosilicon. 81 parts of acrylate monomers (40 parts butyl acrylate, 25 parts methyl methacrylate, 5 parts acrylic acid, 8 parts hydroxyethyl acrylate, 2 parts N-hydroxymethylacrylamide, 1 part octadecyl acrylate) and 0.6 parts of initiator azobisisobutyronitrile were mixed with 50 parts of propylene glycol methyl ether acetate and polymerized at 70°C for 4 hours to obtain a copolymer solution. 25 parts of epoxidized organosilicon and 0.5 parts of triethylamine were added, and the mixture was heated to 90°C and reacted for 3 hours. The temperature was lowered to 65°C, and 5 parts of glycidyl methacrylate and 0.04 parts of polymerization inhibitor hydroquinone were added, and the mixture was reacted for 2 hours. After the reaction was completed, the temperature was lowered to 25°C, and the mixture was distilled under reduced pressure to obtain an epoxy-modified acrylate resin. Step 2: Disperse 10 parts of chitin in an ethanol / water mixture, add glacial acetic acid to adjust the pH to 4; add 3 parts of KH-570, stir and react at 60℃ for 4 h; add 2.5 parts of tetraethyl orthosilicate, adjust the pH to 8, stir and react at room temperature for 12 h; after the reaction is completed, centrifuge, wash, redisperse, dry, and grind to a particle size D50 < 5 μm to obtain the hybrid resin; Step 3: Take 85 parts of UV-curable resin (30 parts of epoxy-modified acrylate resin, 30 parts of epoxy acrylate, 20 parts of polyurethane acrylate, and 5 parts of hybrid resin), 15 parts of reactive diluent, 2 parts of modified nanoparticles, 3 parts of photoinitiator, and 0.7 parts of additives (0.5 parts of wetting and dispersing agent, 0.1 parts of leveling agent, and 0.1 parts of defoamer), mix and disperse to obtain an anti-fingerprint coating; The coating is sprayed onto the substrate surface and then photocured to form an anti-fingerprint coating, resulting in the electronic product casing. The photocuring process includes: leveling at 55℃ for 3 minutes; and UV irradiation for 3 seconds under nitrogen protection, with a dominant wavelength of 365nm and a light energy of 1000mJ / cm². 2 .

[0038] Example 2: A method for preparing an anti-fingerprint electronic product casing, comprising the following processes: Step 1: Under a nitrogen atmosphere and at 0°C, a solution of n-butyllithium in n-hexane was mixed with trifluoropropylmethylcyclotrisiloxane and 2.5 times its volume of tetrahydrofuran, and the mixture was stirred for 5 hours. Finally, dimethylchlorosilane was added, and the reaction was continued for 1.5 hours. The mixture was centrifuged and rotary evaporated to obtain a fluorosilicone compound. Under a nitrogen atmosphere, the fluorosilicone compound and a cassiterite catalyst were mixed in 1.2 times their mass of anhydrous toluene, heated to 45°C, and allyl polyoxyethylene polyoxypropylene ether was added. The mixture was heated to 78°C and reacted for 11 hours. After the reaction, the mixture was distilled under reduced pressure to obtain polyether-modified silicone oil. The molar ratio of trifluoropropylmethylcyclotrisiloxane, dimethylchlorosilane, and n-butyllithium was 10:3:0.15. The molar ratio of the silicon-hydrogen bonds in the fluorosilicone compound, the carbon-carbon double bonds in the allyl polyoxyethylene polyoxypropylene ether, and the catalyst (calculated as Pt) was 100:110:0.005. 100 parts of polyether-modified silicone oil, 10 parts of maleic anhydride, 0.15 parts of 4-dimethylaminopyridine and 0.03 parts of hydroquinone were mixed and heated to 75°C under nitrogen protection, and stirred for 4.5 h to obtain an organosilicon intermediate; 38 parts of epoxy resin and 0.4 parts of triphenylphosphine were added and mixed, and the mixture was heated to 105°C and reacted for another 3.5 h to obtain epoxidized organosilicon. 81 parts of acrylate monomers (38 parts butyl acrylate, 22 parts methyl methacrylate, 6.5 parts acrylic acid, 9 parts hydroxyethyl acrylate, 2.5 parts N-hydroxymethylacrylamide, 3 parts octadecyl acrylate) and 0.7 parts of initiator azobisisobutyronitrile were mixed with 50 parts of propylene glycol methyl ether acetate and polymerized at 75°C for 5 h to obtain a copolymer solution. 30 parts of epoxidized organosilicon and 0.8 parts of triethylamine were added, and the temperature was raised to 95°C and reacted for 4 h. The temperature was lowered to 68°C, and 6.5 parts of glycidyl methacrylate and 0.06 parts of polymerization inhibitor hydroquinone were added, and the reaction was carried out for 2.5 h. After the reaction was completed, the temperature was lowered to 25°C and distilled under reduced pressure to obtain epoxy-modified acrylate resin. Step 2: Disperse 10 parts of chitin in an ethanol / water mixture, add glacial acetic acid to adjust the pH to 4.5; add 4 parts of KH-570, stir and react at 62℃ for 5 h; add 3 parts of tetraethyl orthosilicate, adjust the pH to 8.5, stir and react at room temperature for 18 h; after the reaction is completed, centrifuge, wash, redisperse, dry, and grind to a particle size D50 < 5 μm to obtain the hybrid resin; Step 3: Take 83 parts of UV-curable resin (35 parts epoxy-modified acrylate resin, 25 parts epoxy acrylate, 15 parts polyurethane acrylate, 8 parts hybrid resin), 20 parts reactive diluent, 3.5 parts modified nanoparticles, 4.5 parts photoinitiator, and 1.2 parts additives (0.8 parts wetting and dispersing agent, 0.2 parts leveling agent, and 0.2 parts defoamer), mix and disperse to obtain an anti-fingerprint coating; spray it onto the substrate surface, UV-cur it to form an anti-fingerprint coating, and obtain the electronic product casing; the UV curing process is the same as in Example 1.

[0039] Example 3: A method for preparing an anti-fingerprint electronic product casing, comprising the following processes: Step 1: Under a nitrogen atmosphere and at 0°C, a solution of n-butyllithium in n-hexane was mixed with trifluoropropylmethylcyclotrisiloxane and 3.0 times its volume of tetrahydrofuran, and stirred for 6 hours. Finally, dimethylchlorosilane was added, and the reaction was continued for 2 hours. The mixture was centrifuged and rotary evaporated to obtain a fluorosilicone compound. Under a nitrogen atmosphere, the fluorosilicone compound and the cassiterite catalyst were mixed in 1.5 times their mass of anhydrous toluene, heated to 50°C, and allyl polyoxyethylene polyoxypropylene ether was added. The mixture was heated to 80°C and reacted for 12 hours. After the reaction, the mixture was distilled under reduced pressure to obtain polyether-modified silicone oil. The molar ratio of trifluoropropylmethylcyclotrisiloxane, dimethylchlorosilane, and n-butyllithium was 10:5:0.2. The molar ratio of the silane-hydrogen bonds in the fluorosilicone compound, the carbon-carbon double bonds in the allyl polyoxyethylene polyoxypropylene ether, and the catalyst (calculated as Pt) was 100:115:0.010. Polyether-modified silicone oil, maleic anhydride, 4-dimethylaminopyridine, and hydroquinone were mixed and heated to 80°C under nitrogen protection, and stirred for 4 hours to obtain an organosilicon intermediate. Epoxy resin and triphenylphosphine were then added and mixed, and the mixture was heated to 110°C and reacted for another 3 hours to obtain epoxidized organosilicon. The epoxidized organosilicon comprised the following components by weight: 100 parts polyether-modified silicone oil, 12 parts maleic anhydride, 0.2 parts 4-dimethylaminopyridine, 0.05 parts hydroquinone, 45 parts epoxy resin, and 0.6 parts triphenylphosphine. 81 parts of acrylate monomers (35 parts butyl acrylate, 20 parts methyl methacrylate, 8 parts acrylic acid, 10 parts hydroxyethyl acrylate, 3 parts N-hydroxymethylacrylamide, 5 parts octadecyl acrylate) and 0.8 parts of initiator azobisisobutyronitrile were mixed in 50 parts of propylene glycol methyl ether acetate and polymerized at 80°C for 6 hours to obtain a copolymer solution. 35 parts of epoxidized organosilicon and 1.0 part of triethylamine were added, and the temperature was raised to 100°C and reacted for 5 hours. The temperature was lowered to 70°C, and 8 parts of glycidyl methacrylate and 0.08 parts of polymerization inhibitor hydroquinone were added, and the reaction was carried out for 3 hours. After the reaction was completed, the temperature was lowered to 25°C and distilled under reduced pressure to obtain epoxy-modified acrylate resin. Step 2: Disperse 10 parts of chitin in an ethanol / water mixture, add glacial acetic acid to adjust the pH to 5; add 5 parts of KH-570, stir and react at 65℃ for 6 hours; add 3.5 parts of tetraethyl orthosilicate, adjust the pH to 9, stir and react at room temperature for 24 hours; after the reaction is completed, centrifuge, wash, redisperse, dry, and grind to a particle size D50 < 5 μm to obtain the hybrid resin; Step 3: Take 80 parts of UV-curable resin (40 parts epoxy-modified acrylate resin, 20 parts epoxy acrylate, 10 parts polyurethane acrylate, 10 parts hybrid resin), 25 parts reactive diluent, 5 parts modified nanoparticles, 6 parts photoinitiator and 1.7 parts additives (1.2 parts wetting and dispersing agent, 0.3 parts leveling agent, 0.2 parts defoamer), mix and disperse to obtain an anti-fingerprint coating; spray it on the substrate surface, UV-cur it to form an anti-fingerprint coating, and obtain the electronic product shell; the UV curing process is the same as in Example 1.

[0040] Comparative Example 1: A method for preparing an anti-fingerprint electronic product casing, comprising the following processes: Steps 1 and 3 are the same as in Example 1; Step 2: Disperse 3 parts of KH-570 in 150 parts of ethanol / water mixture, add glacial acetic acid to adjust pH to 4, and stir at 60℃ for 4 h; add 2.5 parts of tetraethyl orthosilicate, adjust pH to 8, and stir at room temperature for 12 h; after the reaction is completed, centrifuge, wash, redisperse, dry, and grind to a particle size D50 < 5 μm to obtain the hybrid resin.

[0041] Comparative Example 2: A method for preparing an anti-fingerprint electronic product casing: Step 1 is the same as in Example 1; Step 2: Take 85 parts of light-curing resin (32 parts of epoxy-modified acrylate resin, 32 parts of epoxy acrylate, 21 parts of polyurethane acrylate), 15 parts of reactive diluent, 2 parts of KH-570 coupling modified nanoparticles, 3 parts of photoinitiator and 0.7 parts of additives, mix and disperse to obtain an anti-fingerprint coating; spray it on the substrate surface, light-cur it to form an anti-fingerprint coating, and obtain the electronic product shell.

[0042] Comparative Example 3: A method for preparing an anti-fingerprint electronic product casing: The prepared polyether-modified silicone oil was replaced with an equal mass of commercially available polyether-modified silicone oil; other process steps and parameters were the same as in Comparative Example 2.

[0043] Comparative Example 4: A method for preparing an anti-fingerprint electronic product casing: The prepared epoxidized organosilicon was replaced with an equal mass of commercially available end-epoxy silicone oil; other process steps and parameters were the same as in Comparative Example 2.

[0044] Comparative Example 5: A method for preparing an anti-fingerprint electronic product casing, comprising the following processes: 85 parts of UV-curable resin (51 parts epoxy acrylate, 34 parts polyurethane acrylate), 15 parts reactive diluent, 2 parts KH-570 coupling-modified nanoparticles, 3 parts photoinitiator, and 0.7 parts additives (0.5 parts wetting and dispersing agent, 0.1 parts leveling agent, and 0.1 parts defoamer) were mixed and dispersed to obtain an anti-fingerprint coating. This coating was then sprayed onto the substrate surface and UV-cured to form an anti-fingerprint coating, resulting in the casing of the electronic product. The UV curing process was as follows: leveling at 55℃ for 3 minutes; UV irradiation for 3 seconds under nitrogen protection, with a dominant wavelength of 365nm and a light energy of 1000mJ / cm². 2 .

[0045] Experiment: Electronic product casings with anti-fingerprint coatings obtained in Examples 1-3 and Comparative Examples 1-5 were used to prepare samples. Their performance was tested and the test results were recorded. Anti-fingerprint performance test: Using artificial sebum simulation liquid, apply it to the sample surface, let it stand for 15 minutes, and then wipe it back and forth 5 times with a soft lint-free cloth at a pressure of 5 kPa. The grade is evaluated (1-5: 5-no visible residue; 4-slight residue, visible under light; 3-significant residue; 2-severe residue; 1-cannot be wiped off). The contact angle of the sample surface is measured using the static drop method with standard test solution (n-hexadecane, surface tension 27.5 mN / m). The sample is then soaked in sweat-resistant liquid (artificial sweat, according to GB / T3922) for 24 hours, then taken out, cleaned and dried, and the grade evaluation test is performed again (1-5: 5-no visible residue; 4-slight residue, visible under light; 3-significant residue; 2-severe residue; 1-cannot be cleaned off).

[0046] Adhesion test: Referring to GB / T9286-2021, a 10×10 grid is drawn on the coating surface using the cross-cut method with a cutter spacing of 1mm. 3M tape is then applied and quickly peeled off at a 60° angle within 0.5-1.0s. The coating peeling off in the grid area is observed. The coating is graded (grades 0-5: grade 0 (completely smooth edges, no peeling) is the best, and grade 5 (peeling area > 65%) is the worst).

[0047] Abrasion resistance test: Refer to GB / T1768-2006, use an abrasion testing machine, load 500g, and subject the sample to 1000 cycles of abrasion. Detect the mass difference (weight loss) of the sample before and after abrasion.

[0048] Surface hardness test: Using a pencil hardness tester, advance it approximately 6.5mm at a 45° angle and with a force of 750g; start testing with the softest pencil and continue until you find the hardest pencil that cannot scratch the coating.

[0049] Impact resistance test: Refer to GB / T1732-2020, impact tester, drop a 1kg hammer from a certain height to impact the coating on the front of the sample; check whether the coating in the impacted area cracks or peels off, and the maximum impact height without cracking is used as the measure. Photocuring volume stability test: The anti-fingerprint coating was degassed and its liquid density was measured; it was poured into a mold and its cured density was measured after photocuring. The volume shrinkage rate of the prepared anti-fingerprint coating was measured by density method.

[0050] Based on the data in the table above, the following conclusions can be clearly drawn: The anti-fingerprint coatings obtained in Examples 1-3 are compared with those obtained in Comparative Examples 1-5. The test results show that... Compared with the comparative examples, the anti-fingerprint coatings obtained in Examples 1-3 have superior experimental performance, which fully demonstrates that the present invention has achieved a comprehensive improvement in the anti-fingerprint, durability, wear resistance, impact resistance and photocuring volume stability of electronic product shell coatings.

[0051] Compared to Example 1, the hybrid resin in Comparative Example 1 was replaced with KH-570 modified resin; in Comparative Example 2, no hybrid resin was used, and the nanoparticles were KH-570 modified. Compared to Comparative Example 2, in Comparative Example 3, commercially available polyether-modified silicone oil was used to replace the prepared epoxidized organosilicon; in Comparative Example 4, the epoxidized organosilicon was replaced with commercially available end-epoxy silicone oil to prepare an epoxy-modified acrylate resin; and in Comparative Example 5, no epoxy-modified acrylate resin was used in the coating component. The performance test data for each component showed deterioration. It can be seen that the design of the anti-fingerprint coating component and its process in this invention promotes a comprehensive improvement in the coating's anti-fingerprint properties, durability, abrasion resistance, impact resistance, and photocuring volume stability.

[0052] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. A method for preparing a fingerprint-resistant electronic product casing, characterized in that: Including the following processes: A mixture of photocurable resin, reactive diluent, nanoparticles, photoinitiator, and additives is prepared and dispersed to obtain an anti-fingerprint coating. The coating is sprayed onto the substrate surface and then photocured to form an anti-fingerprint coating, thus obtaining the casing of the electronic product. The photocurable resin includes epoxy-modified acrylate resin, epoxy acrylate, polyurethane acrylate, and hybrid resin; The epoxy-modified acrylate resin is prepared by reacting acrylate monomers, epoxidized organosilicon, and glycidyl methacrylate.

2. The method for preparing an anti-fingerprint electronic product casing according to claim 1, characterized in that: The epoxy-modified acrylate resin is prepared by the following process: The acrylate monomer and the initiator were mixed in propylene glycol methyl ether acetate and polymerized at 70-80°C for 4-6 hours to obtain a copolymer solution. Add epoxidized organosilicon and triethylamine, heat to 90-100℃, and react for 3-5 hours; cool to 65-70℃, add glycidyl methacrylate and polymerization inhibitor, and react for 2-3 hours to obtain epoxy-modified acrylate resin.

3. The method for preparing an anti-fingerprint electronic product casing according to claim 2, characterized in that: The epoxidized organosilicon is prepared by the following process: Polyether-modified silicone oil, maleic anhydride, 4-dimethylaminopyridine and hydroquinone were mixed and heated to 70-80°C under nitrogen protection, and stirred for 4-5 hours to obtain an organosilicon intermediate. Add epoxy resin and triphenylphosphine, heat to 100-110℃, and continue the reaction for 3-4 hours to obtain epoxidized organosilicon.

4. The method for preparing an anti-fingerprint electronic product casing according to claim 3, characterized in that: The polyether-modified silicone oil is prepared by the following process: A solution of n-butyllithium in n-hexane was added to trifluoropropylmethylcyclotrisiloxane and tetrahydrofuran under a nitrogen atmosphere and at a temperature of 0–5 °C, and the mixture was stirred for 4–6 h. Finally, dimethylchlorosilane was added, and the reaction was continued for 1–2 h to obtain a fluorosilane compound. In a nitrogen atmosphere, a fluorosilicone compound and a catalyst are mixed in anhydrous toluene, heated to 40–50°C, and then allyl polyoxyethylene polyoxypropylene ether is added. The mixture is then heated to 75–80°C and reacted for 10–12 hours to obtain polyether-modified silicone oil.

5. The method for preparing an anti-fingerprint electronic product casing according to claim 1, characterized in that: The hybrid resin is prepared by the following process: Chitosan was dispersed in an ethanol / water mixture, and the pH was adjusted to 4–5. KH-570 was added, and the mixture was stirred at 60–65°C for 4–6 hours. Tetraethyl orthosilicate was added, and the pH was adjusted to 8–9. The mixture was stirred at room temperature for 12–24 hours to obtain the hybrid resin.

6. The method for preparing an anti-fingerprint electronic product casing according to claim 1, characterized in that: The anti-fingerprint coating comprises the following components by weight: 65-100 parts of photocurable resin, 15-25 parts of reactive diluent, 2-5 parts of nanoparticles, 3-6 parts of photoinitiator, and 0.7-2.5 parts of additives; The photocurable resin comprises the following components by weight: 30-40 parts epoxy-modified acrylate resin, 20-30 parts epoxy acrylate, 10-20 parts polyurethane acrylate, and 5-10 parts hybrid resin. The reactive diluent includes hydroxyethyl acrylate, tripropylene glycol diacrylate, and isobornyl acrylate in a mass ratio of 2:5:1.

5.

7. The method for preparing an anti-fingerprint electronic product casing according to claim 2, characterized in that: The epoxy-modified acrylate resin comprises the following components by weight: 80-100 parts acrylate monomer, 25-35 parts epoxidized silicone, 0.6-0.8 parts initiator, 0.5-1.0 parts triethylamine, 5-8 parts glycidyl methacrylate, 0.04-0.08 parts polymerization inhibitor and 50 parts propylene glycol methyl ether acetate; The acrylate monomer comprises the following components by weight: 35-40 parts butyl acrylate, 20-25 parts methyl methacrylate, 5-8 parts acrylic acid, 8-10 parts hydroxyethyl acrylate, 2-3 parts N-hydroxymethylacrylamide, and 1-5 parts octadecyl acrylate.

8. The method for preparing an anti-fingerprint electronic product casing according to claim 3, characterized in that: The epoxidized organosilicon comprises the following components by weight: 100 parts polyether-modified silicone oil, 8-12 parts maleic anhydride, 0.1-0.2 parts 4-dimethylaminopyridine, 0.02-0.05 parts hydroquinone, 30-45 parts epoxy resin, and 0.3-0.6 parts triphenylphosphine.

9. The method for preparing an anti-fingerprint electronic product casing according to claim 5, characterized in that: The hybrid resin comprises the following components by weight: 10 parts chitosan, 3-5 parts KH-570, and 2.5-3.5 parts tetraethyl orthosilicate.

10. A fingerprint-resistant electronic product casing prepared by the method according to any one of claims 1-9.

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