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CN-121975435-A - Fluorine-free fingerprint-proof layer and preparation method and application thereof

CN121975435ACN 121975435 ACN121975435 ACN 121975435ACN-121975435-A

Abstract

The invention relates to a fluorine-free anti-fingerprint layer, a preparation method and application thereof, wherein the fluorine-free anti-fingerprint layer comprises a micro-nano composite structure on a base material and a polysilazane coating arranged on the micro-nano composite structure; the micro-nano composite structure comprises a micro-array distributed on the surface of a substrate and hydrophobic hybrid silica nanospheres distributed on the micro-array. The fluorine-free fingerprint-proof layer provided by the invention has the characteristics of good antifouling fingerprint-proof effect, good wear resistance and good durability.

Inventors

  • SUN AINI
  • Han Wangsheng
  • SONG HUAYUE

Assignees

  • 立铠精密科技(盐城)有限公司

Dates

Publication Date
20260505
Application Date
20260116

Claims (10)

  1. 1. The fluorine-free fingerprint-preventing layer is characterized by comprising a micro-nano composite structure on a base material and a polysilazane coating arranged on the micro-nano composite structure; The micro-nano composite structure comprises a micro-array distributed on the surface of a substrate and hydrophobic hybrid silica nanospheres distributed on the micro-array.
  2. 2. The fluorine-free anti-fingerprint layer of claim 1, wherein the microarray is a micropillar array; Preferably, the average height of the micro-column units in the micro-column array is 3-4 μm; Preferably, the shape of the micro-column unit in the micro-column array is any one or a combination of at least two of hexagonal prism, pentagonal prism, quadrangular prism and triangular prism; preferably, the diameter of the circumcircle of the upper bottom surface of the microcolumn unit is 5-10 μm; preferably, the center distance between two adjacent microcolumn units in the microcolumn array is 7-12 μm; preferably, the average particle size of the hydrophobic hybrid silica nanospheres is 30-70 nm.
  3. 3. The method for preparing the fluorine-free fingerprint-preventing layer according to claim 1 or 2, which is characterized by comprising the steps of forming a micro-array on the surface of a substrate by etching, forming a micro-nano composite structure by in-situ growing hydrophobic hybrid silica nanospheres on the micro-array, and then adding a polysilazane coating on the micro-nano composite structure to obtain the fluorine-free fingerprint-preventing layer.
  4. 4. The method according to claim 3, wherein the etching is preceded by the steps of alkaline cleaning, acidic cleaning, water cleaning and oxygen plasma treatment of the substrate; Preferably, the substrate comprises an anodized aluminum alloy and/or glass; Preferably, the alkaline cleaning agent comprises a sodium hydroxide solution, wherein the mass percentage concentration of the sodium hydroxide solution is 3% -8%; Preferably, the alkaline cleaning agent cleaning comprises ultrasonic cleaning by adopting an alkaline cleaning agent, wherein the ultrasonic cleaning temperature is 50-70 ℃ and the ultrasonic cleaning time is 3-8 min; preferably, the acidic cleaning agent comprises a nitric acid solution, wherein the mass percentage concentration of the nitric acid solution is 5% -15%; preferably, the cleaning temperature of the acidic cleaning agent is 15-35 ℃ and the cleaning time is 1-3 min; preferably, the power of the oxygen plasma treatment is 200-400W, and the time is 30-90 s.
  5. 5. The method according to claim 3 or 4, wherein the step of forming the micro-array on the surface of the substrate by etching comprises the steps of spin-coating negative photoresist on the surface of the substrate, first baking, exposing with a mask of a preset pattern, developing to form a photoresist micro-column array, second baking, plasma etching, removing residual negative photoresist, and forming the micro-array on the surface of the substrate; Preferably, the spin coating comprises spin coating at a rotation speed of 300-600 rpm for 8-12 s, and then spin coating at a rotation speed of 2500-3500 rpm for 25-35 s; Preferably, the thickness of the adhesive film formed by spin coating is 4-6 μm; Preferably, the temperature of the first drying is 90-100 ℃ and the time is 2-4 min; preferably, the exposure is performed using a stepper; Preferably, the wavelength of the exposed ultraviolet light is 300-370 nm, and the energy is 120-180 mJ/cm 2 ; preferably, the temperature of the second drying is 140-160 ℃ and the time is 4-6 min.
  6. 6. The method according to claim 5, wherein the etching gas used for the plasma etching is carbon tetrafluoride and oxygen, the flow rate of the carbon tetrafluoride is 40-60 sccm, and the flow rate of the oxygen is 5-15 sccm; preferably, the source power of the plasma etching is 1400-160W; preferably, the bias power of the plasma etching is 80-120W; preferably, the cavity pressure of the plasma etching is 1.5-2.5 Pa; preferably, the plasma etching time is 80-100 s; preferably, the etching depth of the plasma etching is 3-4 mu m; preferably, the removing the residual negative photoresist comprises removing the residual negative photoresist with a piranha solution.
  7. 7. The method for preparing the micro-nano composite structure according to any one of claims 3 to 5, wherein the in-situ growing of the hydrophobic hybrid silica nanospheres on the micro-array comprises in-situ growing of the hydrophobic hybrid silica nanospheres on the micro-array by using ethyl orthosilicate and hydrophobic siloxane as mixed silicon sources to form the micro-nano composite structure; Preferably, the in-situ growth of the hydrophobic hybrid silica nanospheres on the microarray to form the micro-nano composite structure comprises the following steps: (1) Mixing tetraethoxysilane, hydrophobic siloxane, ammonia water and a solvent to obtain a mixed silicon source solution; (2) The mixed silicon source solution prepared in the step (1) is adopted to impregnate a substrate with a micro-array on the surface for reaction, and then the substrate is taken out and is subjected to heat treatment, so that the hydrophobic hybridized silicon dioxide nanospheres grow on the micro-array in situ to form a micro-nano composite structure; preferably, the mass percentage concentration of the tetraethoxysilane in the mixed silicon source solution is 3% -7%; preferably, the mass percentage concentration of the hydrophobic siloxane in the mixed silicon source solution is 2% -4%; preferably, the hydrophobic siloxane comprises methyltriethoxysilane; Preferably, the concentration of the ammonia water is 0.05-0.15 mol/L; Preferably, the mass percentage concentration of the ammonia water in the mixed silicon source solution is 0.5% -1.5%; preferably, the solvent comprises ethanol and water with the volume ratio of (8-19): 1; preferably, the temperature of the reaction in the step (2) is 45-55 ℃ and the time is 3-5 hours; Preferably, the heat treatment in the step (2) further comprises the step of ultrasonic cleaning by adopting ethanol; preferably, the temperature of the heat treatment in the step (2) is 110-130 ℃ and the time is 20-40 min.
  8. 8. The method according to any one of claims 3 to 7, wherein the adding a polysilazane coating comprises adding a polysilazane coating by vapor deposition or spraying; preferably, the additional polysilazane coating comprises the steps of spraying hyperbranched polysilazane solution, curing and completing the additional polysilazane coating; Preferably, the spraying comprises ultrasonic spraying; Preferably, the diameter of the nozzle for ultrasonic spraying is 0.25-0.35 mm; Preferably, the atomization pressure of the ultrasonic spraying is 0.15-0.25 MPa; Preferably, the temperature of the ultrasonic-sprayed substrate is 70-90 ℃; Preferably, the moving speed of the ultrasonic spraying is 40-60 mm/s; Preferably, the thickness of the wet film formed by ultrasonic spraying is 80-120 nm.
  9. 9. The method of claim 8, wherein the curing is performed under nitrogen; Preferably, the curing includes photo-curing and thermal-curing; preferably, the photo-curing comprises ultraviolet light curing; Preferably, the wavelength of ultraviolet light in ultraviolet light curing is 200-280 nm, and the energy is 800-1200 mJ/cm 2 ; Preferably, the heat curing temperature is 110-130 ℃ and the time is 0.5-1.5 h.
  10. 10. The application of the fluorine-free fingerprint-preventing layer as claimed in claim 1 or 2 or the fluorine-free fingerprint-preventing layer prepared by the preparation method as claimed in any one of claims 3 to 9 in 3C products.

Description

Fluorine-free fingerprint-proof layer and preparation method and application thereof Technical Field The invention relates to the technical field of anti-fingerprint materials, in particular to a fluorine-free anti-fingerprint layer, and a preparation method and application thereof. Background At present, along with the development of 3C products (such as smart phones, notebook computers and wearable devices) to high-end and personalized, the antifouling and fingerprint-proof performances of the shell (mostly made of aluminum alloy anodic oxidation materials) and the screen (made of glass materials) become the key for improving the user experience. At present, the mainstream technology for realizing the antifouling and anti-fingerprint performance is to coat a fluorine-containing silane reagent (such as perfluorooctyl triethoxysilane) on the surface, and realize the antifouling and anti-fingerprint effect by utilizing the low surface energy of a fluorocarbon chain. The technical scheme for realizing the antifouling and anti-fingerprint effects by coating the fluorine-containing silane reagent has the following defects that firstly, perfluorinated compounds (PFCs) are difficult to degrade in nature, have bioaccumulation, are strictly limited by global environmental protection regulations (such as European Union REACH and POPs regulations), have no environmental protection, secondly, the antifouling and anti-fingerprint effects of a coating formed by coating the fluorine-containing silane reagent are limited, particularly, the oil-repellent effect is insufficient (the oil drop angle is usually lower than 70 degrees), the formed coating is softer, the wear resistance is poor, the performance is sharply reduced after friction such as steel wool is used, thirdly, the binding force between the coating formed by coating the fluorine-containing silane reagent and a substrate is limited, the chemical properties such as sweat resistance, cosmetics resistance, solvent resistance and the like are insufficient, and the coating is easy to lose efficacy after long-term use and the durability is poor. Therefore, there is a need to develop an anti-fingerprint film which does not contain fluorine, is anti-fouling and anti-fingerprint, and has good abrasion resistance and durability. Disclosure of Invention In order to solve the technical problems, the invention provides a fluorine-free fingerprint-proof layer, and a preparation method and application thereof. The fluorine-free anti-fingerprint layer has the characteristics of good anti-fouling and anti-fingerprint effect, good wear resistance and good durability. To achieve the purpose, the invention adopts the following technical scheme: In a first aspect, the invention provides a fluorine-free fingerprint-preventing layer, which comprises a micro-nano composite structure on a substrate and a polysilazane coating arranged on the micro-nano composite structure, wherein the micro-nano composite structure comprises a micro array distributed on the surface of the substrate and hydrophobic hybridized silica nanospheres distributed on the micro array. According to the invention, the micro array forms a primary micro structure and provides macroscopic hydrophobicity and mechanical support, the hydrophobic hybridized silica nanospheres distributed on the micro array form a secondary nano structure, the liquid repellency can be enhanced and the surface area can be increased by capturing air, the polysilazane coating provides lasting and extremely low surface energy, and the effect of 1+1+1>3 is realized by triple cooperation of physical structure, chemical modification and top layer reinforcement, so that the prepared fluorine-free fingerprint-proof layer surface has the characteristics of good antifouling fingerprint-proof effect, good wear resistance and good durability. Preferably, the microarray is a micropillar array. Preferably, the average height of the micro-column units in the micro-column array is 3-4 μm, for example 3.1 μm, 3.2 μm, 3.3 μm, 3.4 μm, 3.5 μm, 3.6 μm, 3.7 μm, 3.8 μm or 3.9 μm, etc. Preferably, the shape of the micro-column unit in the micro-column array is any one or a combination of at least two of hexagonal prism, pentagonal prism, quadrangular prism and triangular prism. Preferably, the diameter of the circumscribing circle of the upper bottom surface of the microcolumn unit is 5 to 10 μm, for example, 5.5 μm, 6 μm, 6.5 μm, 7 μm, 7.5 μm, 8 μm, 8.5 μm, 9 μm, 9.5 μm, or the like. Preferably, the center-to-center distance between two adjacent micro-column units in the micro-column array is 7-12 μm, for example 7.5 μm, 8 μm, 8.5 μm, 9 μm, 9.5 μm, 10 μm, 10.5 μm, 11 μm or 11.5 μm, etc. Preferably, the average particle size of the hydrophobic hybrid silica nanospheres is 30-70 nm, such as 35 nm, 40 nm, 45 nm, 50nm, 55 nm, 60 nm or 65 nm, etc. In a second aspect, the invention provides a preparation method of the fluorine-free fingerprint-preventing layer, which c