Composite functional film as well as preparation method and application thereof

Abstract

The invention relates to the technical field of functional film materials, and discloses a composite functional film and a preparation method and application thereof, and the composite functional film comprises a base material layer, a bonding layer, an optical functional layer, a superhard layer and an anti-fingerprint layer. The composite functional film can selectively filter ultraviolet light and blue light with the wavelength of 380-460 nm, the filtering efficiency reaches up to 99%, and the composite functional film has an efficient eye protection function; in addition, the coating also has the functions of scratch resistance, wear resistance and fingerprint resistance, and the nanoindentation hardness is greater than or equal to 14 GPa; the initial water drop angle is larger than 110 degrees, rubber friction resistance is achieved, the water drop angle is larger than or equal to 100 degrees through 10000 times of rubber cycle tests, the anti-reflection function is achieved, and the transmittance of 470-700 nm is larger than or equal to 92%. The film is directly integrated on a screen by adopting a vacuum coating process, and the film layer is high in reliability, not easy to fall off, wear-resistant and long in service life.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of functional film materials, in particular to a composite functional film and a preparation method and application thereof. BACKGROUND

[0002] With the popularization of display electronic products (such as televisions, mobile phones, computers, tablets, etc.), the harm of high-energy short-wave blue light (400-460nm) emitted by the screen to human eye health has been increasingly concerned. This band of blue light can penetrate the lens and reach the retina, causing macular degeneration, deepening of myopia, visual fatigue and other problems. The current anti-blue light technology on the market is mostly applied to glasses or protective films, which has defects such as low filtering rate (usually less than 40%), poor film layer wear resistance, easy peeling and easy wear.

[0003] Directly integrating multifunctional film layers on the screen substrate through vacuum coating technology is an effective way to solve the above problems. However, how to design a film layer structure that can simultaneously achieve high-efficiency blue light filtering, high hardness, high wear resistance, excellent anti-fingerprint performance and high transmittance, and firm bonding between the film layers, is a technical problem to be solved in the field.

[0004] In addition, the organic materials such as polarizing plates, adhesives, and back light films in the display module will undergo photo-oxidation under long-term ultraviolet irradiation, resulting in yellowing, embrittlement, and delamination, thereby reducing the optical performance. The decline of optical performance mainly manifests in the following aspects: Polarizing plate failure, ultraviolet light can accelerate the aging of the polarizing plate, reduce its polarization efficiency, cause the screen to appear white, uneven brightness or poor viewing angle. Back light attenuation, the fluorescent powder or light guide plate in the LED backlight may degrade under ultraviolet irradiation, affecting the display brightness and color temperature stability. Color drift and fading, ultraviolet light can decompose the color filter (such as the RGB filter layer of LCD) or the light-emitting material of OLED, resulting in a decrease in color saturation and color deviation (such as blue or yellow). Adhesive failure, delamination risk, ultraviolet light can harden or lose the adhesion of optical adhesive (OCA), sealant and other adhesives in the module, causing the screen to delaminate, get dirty or have bubbles. Circuit and component damage, encapsulation material aging, ultraviolet light can cause the flexible circuit (FPC) or encapsulation material protective layer to crack, causing circuit oxidation, short circuit or open circuit. In LCD, ultraviolet light can affect the stability of the threshold voltage of TFT (thin film transistor), causing display ghosting or driving abnormalities. Ultraviolet light and high temperature superposition, ultraviolet light often accompanied by high temperature, can accelerate material aging, deformation or solder cracking.

[0005] Therefore, it is of great practical significance to provide a composite functional film and a preparation method and application thereof. SUMMARY

[0006] In view of this, the present application provides a composite functional film and a preparation method and application thereof, aiming to solve at least one technical problem in the background art.

[0007] The present application provides a composite functional film, comprising: a substrate layer, a bonding layer, an optical functional layer, a superhard layer and an anti-fingerprint layer; The substrate layer is one or more of soda-lime glass, silica-alumina glass, microcrystalline glass or flexible material; The bonding layer is one of SiO2, Al2O3 or metal Cr; The optical functional layer is an interference filter functional layer formed by alternately stacking high refractive index materials and low refractive index materials; The superhard layer is one of diamond-like, TiCrCN, (AlCrTiVZr)N, carbon nitride or titanium nitride; The anti-fingerprint layer uses anti-fingerprint liquid medicine.

[0008] Preferably, the flexible material is ultra-thin glass, colorless polyimide or polyethylene terephthalate; the thickness of the bonding layer is 1-100 nm.

[0009] Preferably, the high refractive index material is one or more of titanium dioxide, zirconium oxide, silicon nitride or niobium oxide; the low refractive index material is one or more of magnesium fluoride, silicon dioxide or aluminum oxide.

[0010] Preferably, the number of layers of the optical functional layer is 8-30 layers.

[0011] The present application also provides a preparation method of the composite functional film described in the above technical solution, comprising the following steps: (1) Pretreatment: pretreating the surface of the substrate to obtain a pretreated substrate; (2) Plating a bonding layer: depositing a bonding layer on the surface of the pretreated substrate by magnetron sputtering to obtain a substrate with a bonding layer; (3) Plating an optical functional layer: alternately sputtering high refractive index materials and low refractive index materials on the surface of the substrate with a bonding layer by magnetron sputtering to obtain a substrate with an optical functional layer; (4) Plating a superhard layer: depositing a superhard layer on the surface of the substrate with an optical functional layer by magnetron sputtering; (5) Plating an anti-fingerprint layer: evaporating anti-fingerprint liquid medicine to the surface of the superhard layer to form an anti-fingerprint layer by resistance heating evaporation to obtain the composite functional film.

[0012] Preferably, in step (2), when the bonding layer material is SiO2, the process parameters of the magnetron sputtering method are: target power 8-20 KW, voltage 200-1000 V, argon flow rate 100-1000 sccm, and oxygen flow rate 100-1500 sccm; When the bonding layer material is Al2O3, the process parameters of the magnetron sputtering method are: target power 8-20 KW, voltage 200-1000 V, argon flow rate 100-1000 sccm, and oxygen flow rate 100-1500 sccm; When the bonding layer material is metal Cr, the process parameters of the magnetron sputtering method are: target power 8-20 KW, voltage 200-1000 V, and argon flow rate 100-1000 sccm.

[0013] Preferably, in step (3), when the optical functional layer material is magnesium fluoride, silicon dioxide or aluminum oxide, the process parameters of the magnetron sputtering method are: target power 8-20 KW, voltage 200-1000 V, argon flow rate 100-1000 sccm, and oxygen flow rate 100-1500 sccm; When the optical functional layer material is silicon nitride, the process parameters of the magnetron sputtering method are: target power 8-20 KW, voltage 200-1000 V, argon flow rate 100-1000 sccm, and nitrogen flow rate 100-1500 sccm; When the optical functional layer material is niobium oxide, the process parameters of the magnetron sputtering method are: target power 8-20 KW, voltage 200-1000 V, argon flow rate 100-1000 sccm, and oxygen flow rate 100-1500 sccm; When the optical functional layer material is titanium dioxide, the process parameters of the magnetron sputtering method are: target power 8-20 KW, voltage 200-1000 V, argon flow rate 100-1000 sccm, and oxygen flow rate 100-1500 sccm; When the optical functional layer material is zirconium oxide, the process parameters of the magnetron sputtering method are: target power 8-20 KW, voltage 200-1000 V, argon flow rate 100-1000 sccm, and oxygen flow rate 100-1500 sccm.

[0014] Preferably, in step (4), when the superhard layer material is carbon nitride, a direct current sputtering method is used, graphite is used as the target material, and the sputtering is carried out in a nitrogen and argon atmosphere, with argon flow rate being 50-600 sccm, nitrogen flow rate being 60-600 sccm, and target current being 8-30 A; When the superhard layer material is diamond-like, high-purity graphite target (purity ≥ 99.99%) is used as the target material, high-power pulsed magnetron sputtering (HiPIMS) is used, and the process is carried out in an argon and hydrogen-containing gas (C2H2) atmosphere, with an argon flow rate of 50-200 sccm, an acetylene gas flow rate of 10-200 sccm, a duty cycle of 3-10%, and a peak power of 100-2000 W / cm2. 2 ; When the superhard layer material is TiCrCN, metal titanium and metal chromium (or titanium-chromium alloy) are used as the target material, high-power pulsed magnetron sputtering (HiPIMS) is used, and the process is carried out in an argon, nitrogen, and acetylene gas atmosphere, with an argon flow rate of 50-200 sccm, a nitrogen flow rate of 250-1000 sccm, an Ar:N2 flow rate ratio of 1:1-5:1, an acetylene gas flow rate of 10-200 sccm, a pulse frequency of 50-1000 Hz, a duty cycle of 3-10%, and a peak power of 100-2000 W / cm2. When the superhard layer material is (AlCrTiVZr)N, an AlCrTiVZr alloy target is used as the target material, high-power pulsed magnetron sputtering (HiPIMS) is used, and the process is carried out in an argon and nitrogen atmosphere, with an argon flow rate of 50-200 sccm, a nitrogen flow rate of 250-1000 sccm, an Ar:N2 flow rate ratio of 1:1-5:1, a pulse frequency of 50-1000 Hz, a duty cycle of 3-10%, and a peak power of 100-2000 W / cm2. 2 ; When the superhard layer material is titanium nitride, a metal titanium target is used, and the process is carried out using a medium-frequency magnetron sputtering method in a nitrogen and argon atmosphere, with an argon flow rate of 300-1200 sccm, a nitrogen flow rate of 300-1200 sccm, and a target power of 8-20 kw.

[0015] The application also provides a use of the composite functional film in the preparation of a display device screen.

[0016] Preferably, the display device includes a mobile phone, a computer, a tablet, a smart watch, a television, or a vehicle-mounted display screen. The composite functional film is arranged on the outer surface, the inner surface, or as a sandwich layer of the screen.

[0017] Compared with the prior art, the application has the following advantages: The composite functional film has a filtering efficiency of UVA (315-400 nm) ultraviolet light and UVB (280-315 nm) ultraviolet light of 10-99%, and the highest filtering efficiency can reach 99%, has a high eye protection function, in addition, has a reflection reduction and transmission enhancement effect on visible light of 400-700 nm, and the light transmittance is >92%; in addition, has scratch resistance, wear resistance and fingerprint resistance, the nano indentation hardness is >=14GPa; the initial water drop angle is >110 DEG, and the rubber friction resistance is that after 10,000 times of rubber eraser cycle test, the water drop angle is >=100 DEG.

[0018] The vacuum plating process is directly integrated on the screen, the film layer has strong reliability, is not easy to fall off, is wear-resistant, and has a long service life. DETAILED DESCRIPTION

[0019] The detailed description of the various exemplary embodiments of the present application is not to be considered as limiting the application, but rather merely as an illustration of certain aspects, features and embodiments of the application. It should be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0020] In addition, for the numerical ranges in the present application, it should be understood that each intermediate value between the upper limit and the lower limit of the range is also specifically disclosed. Each smaller range within any stated range or within any stated intermediate value is also included in the present application. The upper and lower limits of these smaller ranges can be independently included or excluded from the range.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present application, the preferred methods and materials are described. All documents mentioned herein are incorporated by reference to disclose and describe the methods and / or materials in connection with which the documents are cited. In case of conflict, the content of the present specification will control.

[0022] Various modifications and changes can be made to the specific embodiments of the present application described herein without departing from the scope or spirit of the application. Other embodiments of the application will be apparent to those of ordinary skill in the art from the description and examples presented herein. The description and examples are illustrative of the application and are not intended to limit the scope of the application.

[0023] As used herein, the terms "comprise", "comprising", "include", "including", "have", "having" and the like are open-ended and do not exclude additional elements or steps.

[0024] The application provides a composite functional film, comprising: a substrate layer, a bonding layer, an optical functional layer, a superhard layer and an anti-fingerprint layer. The substrate layer is one or more of soda-lime glass, silica-alumina glass, microcrystalline glass or flexible material. The bonding layer is one of SiO2, Al2O3 or metal Cr. The optical functional layer is an interference filter functional layer formed by alternately stacking high-refractive-index material and low-refractive-index material. The superhard layer is one of diamond-like carbon, TiCrCN, (AlCrTiVZr)N, carbon nitride or titanium nitride. The anti-fingerprint layer adopts anti-fingerprint liquid medicine.

[0025] In the application, the flexible material is preferably ultra-thin glass, colorless polyimide or polyethylene terephthalate; and the thickness of the bonding layer is preferably 1-100 nm.

[0026] The substrate layer is one or more of soda-lime glass, silica-alumina glass, microcrystalline glass or flexible material. Specifically, the substrate layer of the composite functional film is the bottom layer of the bonding layer, the optical functional layer, the superhard layer, the anti-fingerprint layer and the display device screen functional film layer, and the substrate layer of the application can be made of rigid material or flexible material, wherein the rigid substrate is soda-lime glass, silica-alumina glass and microcrystalline glass, the soda-lime glass and the silica-alumina glass are low in cost (30%-50% lower than the microcrystalline glass), mature in mass production and suitable for large-size low-cost display devices such as televisions and computers; the microcrystalline glass is high in hardness (Mohs hardness ≥ 6.5) and low in thermal expansion coefficient (≤ 5×10 -6 / ℃), suitable for vehicle display screens (long-term exposure to high temperature and temperature difference environment) and high-end mobile phone screens, and can reduce the risk of film layer cracking caused by temperature change. The flexible material has the following advantages: ultra-thin glass (UTG) has flexibility and high hardness (Mohs hardness ≥ 6), solving the problem of low hardness of traditional PET film and easy scratching; colorless polyimide (CPI) is resistant to high and low temperature (-60℃-200℃) and chemical corrosion, and is suitable for flexible display devices in harsh environments (such as outdoor smartwatches); PET film is extremely low in cost and light in weight, and is suitable for low-cost flexible protective film and display device accessories for temporary use.

[0027] The bonding layer is one of SiO2, Al2O3 or metal Cr. In the present application, the bonding layer mainly eliminates the interface compatibility problem between the substrate and the functional layer, and ensures the stable combination of the two. Specifically, for glass substrates (such as soda-lime glass, silicon-aluminum glass), the metal oxide in the bonding layer can form a chemical bond (such as a covalent bond, a coordination bond) with the hydroxyl group (-OH) on the surface of the glass, thereby enhancing the interfacial adhesion; for flexible materials (such as PET, CPI), the metal in the bonding layer can form a dense thin film through vacuum sputtering, filling the small bumps and pits on the surface of the flexible material (microscopic defects easily generated by the forming process of the flexible material), reducing the interfacial voids, and avoiding the subsequent functional layer from falling off due to "interface voids".

[0028] In addition, the present application also limits the thickness of the bonding layer to be 1-100 nm. The thickness design of the bonding layer can correct the microscopic unevenness of the substrate surface, and provide a uniform substrate for the precise deposition of the functional layer (thickness 300-3000 nm, number of layers 8-30).

[0029] The optical functional layer is an interference filter functional layer formed by alternately stacking high refractive index materials and low refractive index materials. In the present application, the high refractive index material is preferably one or more of titanium dioxide, zirconium oxide, silicon nitride or niobium oxide; and the low refractive index material is preferably one or more of magnesium fluoride, silicon dioxide or aluminum oxide.

[0030] More preferably, the refractive index n of the low refractive index material in the present application is in the range of 1.38-1.7, and the refractive index n of the high refractive index material is in the range of 1.8-2.7.

[0031] In the present application, the number of layers of the optical functional layer is preferably 8-30 layers.

[0032] In the present application, when the high refractive index material and the low refractive index material are alternately stacked, the incident light will be reflected and refracted at the interface of each layer. When the phase difference of the reflected light of 400-460 nm high-energy short-wave blue light (harmful waveband to the human eye) meets the "destructive interference" condition (the phase difference of the reflected light is an odd multiple of π), the blue light in this waveband will be filtered due to energy cancellation; at the same time, by designing the thickness of each layer of material (usually 1 / 4 or 1 / 2 of the target filtered waveband wavelength), the waveband range of destructive interference can be precisely controlled, ensuring that only harmful blue light is filtered, without affecting the transmission of other wavebands.

[0033] The optical functional layer of the present application selectively filters light in a specific wavelength range through the interference effect of light, filters harmful blue light and ultraviolet light while ensuring high transmittance of visible light, and the difference in refractive index between the two types of materials can reduce the reflection loss of visible light at the interface of the film layer (the reflectivity is positively correlated with the difference in refractive index, and the smaller the difference, the lower the reflection loss); by adjusting the number of stacked layers (8-30 layers) and the thickness of each layer, the visible light in the film layer is mainly in "constructive interference" (the phase difference of the transmitted light is an even multiple of π), which further improves the transmittance and avoids the problem of yellowing of the picture and attenuation of brightness caused by "excessive filtering" of traditional blue light prevention film.

[0034] Traditional blue light prevention film usually uses the "dye absorption" principle, and the blue light filtering rate is usually less than 40%, and the filtering effect is easily attenuated due to dye aging; while in the present application, the interference filter structure formed by high and low refractive index materials can stably reach 60%-99% of blue light filtering efficiency, and the filtering efficiency of UVA (315-400nm) ultraviolet light and UVB (280-315nm) ultraviolet light can be up to 99%, and the filtering effect is determined by physical interference and is not affected by the use time, environmental temperature and humidity (-40℃-85℃), and the filtering rate fluctuation is ≤5% after long-term use, which can effectively reduce the damage of harmful blue light to the retina and reduce the risk of visual fatigue and myopia deepening.

[0035] In addition, the high and low refractive index materials used in the present application are inorganic non-metals or oxides / nitrides, which have excellent chemical stability and weather resistance. Specifically, the materials have high hardness (such as TiO2 Mohs hardness about 5.5, SiO2 Mohs hardness about 6.5), which can withstand daily slight friction (such as finger wiping, soft cloth cleaning), and avoid the decline of filtering effect caused by "dye layer abrasion" of traditional dye type film. Environmental interference resistance: in high temperature (85℃) and high humidity (90%RH) environment, the materials have no oxidation and hydrolysis phenomenon, and the film layer structure is stable, which is suitable for complex scenes such as vehicle display screen (long-term exposure to high temperature and dust) and outdoor intelligent equipment, and the service life can reach 3-5 years, which is much longer than the traditional film (3-6 months replacement cycle).

[0036] The superhard layer is one of diamond-like carbon (DLC), TiCrCN, (AlCrTiVZr)N, carbon nitride or titanium nitride; First, the ultra-hard layer acts as an "external protective barrier" for the composite functional film, resisting physical damage during daily use and preventing the underlying optical functional layer and bonding layer from failing due to wear. During use, display screens are easily exposed to hard objects such as keys, grit, and pen tips, or repeatedly rubbed by fingers or wiping cloths. The ultra-hard layer, through its high hardness, directly blocks such physical actions from damaging the underlying film layer. For example, when the screen surface is scratched by grit, the ultra-hard layer can withstand the localized pressure generated by the scratch, preventing the scratch from penetrating to the optical functional layer (8-30 layers of alternately stacked high / low refractive index materials, such as TiO2 and SiO2. Although these materials have excellent optical properties, their low hardness makes them prone to breakage due to scratches). This ensures the integrity of the interference filter structure of the optical functional layer, maintaining the core performance of 400-460nm blue light filtering and high visible light transmittance.

[0037] Furthermore, the super-hard layer enhances the composite functional film's resistance to minor impacts, adapting to diverse usage scenarios of display devices (such as mobile phone drops and vibrations in automotive displays). When a display device experiences a minor impact (such as a mobile phone slipping off a table), the super-hard layer can disperse the impact energy through its high-strength characteristics, preventing the film from cracking or delaminating due to the impact. For example, automotive displays are constantly exposed to vibration, and the super-hard layer can reduce the impact of vibration on the stacked structure of the optical functional layers, preventing a decrease in filtering accuracy due to interlayer displacement (such as blue light filtering rate fluctuations exceeding 10%). At the same time, for handheld devices such as mobile phones and tablets, the super-hard layer can reduce the probability of screen surface damage during drops, extending the lifespan of the composite functional film.

[0038] The reason why the superhard layer described in this invention has the above-mentioned excellent effects is that this invention has made special provisions for the material of the superhard layer, specifically: Diamond-like carbon (DLC): Its hardness can reach 15~25GPa (nanoindentation test) and its coefficient of friction is extremely low (≤0.1). It can not only resist scratches from hard objects (can withstand scratches with a hardness of 6H or higher), but also reduce frictional resistance during wiping and avoid wear of the film layer due to friction. TiCrCN and (AlCrTiVZr)N: These multi-component nitrides can achieve a hardness of 12~20GPa and also have high toughness. Compared with single nitrides, they can better withstand impact and bending (suitable for flexible materials, such as ultra-thin glass and colorless polyimide), avoiding interlayer cracking caused by impact. Carbon nitride (Carbon Nitride) and Titanium Nitride (TiN): with hardness of 10~18GPa and 15~20GPa respectively, and excellent chemical stability. They are not easily oxidized or corroded in humid environments (humidity above 90%) or when in contact with sweat (containing salt and oil), ensuring stable long-term protective performance.

[0039] Furthermore, diamond-like carbon (DLC), TiCrCN, (AlCrTiVZr)N, carbon nitride, and TiN all possess extremely strong resistance to oxidation and hydrolysis. They exhibit no oxidation discoloration or interlayer delamination even under high and low temperature cycling from -40℃ to 85℃ and in humid and hot environments with humidity exceeding 90%. They are suitable for scenarios such as automotive displays (exposed to high temperatures in summer and low temperatures in winter) and outdoor smartwatches (contact with rain and sweat). In daily use, the screen may come into contact with alcohol (cleaning agents) and sweat (containing salt and organic acids). These materials can resist the erosion of these chemicals, preventing the film layer from dissolving or its performance from degrading (such as traditional resin coatings, which are prone to a decrease in hardness due to alcohol wiping), ensuring the long-term stability of the ultra-hard layer's protective performance.

[0040] This invention also provides a method for preparing the composite functional membrane described in the above technical solution, comprising the following steps: (1) Pretreatment: The surface of the substrate is pretreated to obtain the pretreated substrate; (2) Depositing bonding layer: A bonding layer is deposited on the surface of the pretreated substrate by magnetron sputtering to obtain a substrate with a bonding layer; (3) Depositing an optical functional layer: Using magnetron sputtering, high refractive index material and low refractive index material are alternately sputtered on the surface of the substrate with the bonding layer to obtain a substrate with an optical functional layer; (4) Depositing an ultrahard layer: An ultrahard layer is deposited on the surface of the substrate with the optical functional layer by magnetron sputtering. (5) Applying an anti-fingerprint layer: The anti-fingerprint solution is evaporated onto the surface of the superhard layer using a resistance heating evaporation method to form an anti-fingerprint layer, thereby obtaining the composite functional film.

[0041] (1) Pretreatment: The surface of the substrate is pretreated to obtain the pretreated substrate; Before coating the substrate, the surface of the substrate is first pretreated by cleaning it to facilitate subsequent coating.

[0042] (2) Depositing bonding layer: A bonding layer is deposited on the surface of the pretreated substrate by magnetron sputtering to obtain a substrate with a bonding layer; In this invention, in step (2), when the bonding layer material used is SiO2, the process parameters of the magnetron sputtering method are: target power 8-20KW, voltage 200-1000V, argon flow rate 100-1000sccm, oxygen flow rate 100-1500sccm. When the bonding layer material used is Al2O3, the process parameters of the magnetron sputtering method are: target power 8-20KW, voltage 200-1000V, argon flow rate 100-1000sccm, and oxygen flow rate 100-1500sccm. When the bonding layer material used is metallic Cr, the process parameters of the magnetron sputtering method are: target power 8-20KW, voltage 200-1000V, and argon flow rate 100-1000sccm.

[0043] (3) Depositing an optical functional layer: Using magnetron sputtering, high refractive index material and low refractive index material are alternately sputtered on the surface of the substrate with the bonding layer to obtain a substrate with an optical functional layer; In this invention, in step (3), when the optical functional layer material used is magnesium fluoride, silicon dioxide or aluminum oxide, the process parameters of the magnetron sputtering method are preferably: target power 8-20KW, voltage 200-1000V, argon flow rate 100-1000sccm, oxygen flow rate 100-1500sccm. When the optical functional layer material used is silicon nitride, the process parameters of the magnetron sputtering method are: target power 8-20KW, voltage 200-1000V, argon flow rate 100-1000sccm, and nitrogen flow rate 100-1500sccm. When the optical functional layer material used is niobium oxide, the process parameters of the magnetron sputtering method are: target power 8-20KW, voltage 200-1000V, argon flow rate 100-1000sccm, and oxygen flow rate 100-1500sccm. When the optical functional layer material used is titanium dioxide, the process parameters of the magnetron sputtering method are: target power 8-20KW, voltage 200-1000V, argon flow rate 100-1000sccm, and oxygen flow rate 100-1500sccm. When the optical functional layer material used is zirconium oxide, the process parameters of the magnetron sputtering method are: target power 8-20 kW, voltage 200-1000 V, argon flow rate 100-1000 sccm, and oxygen flow rate 100-1500 sccm. (4) Depositing an ultrahard layer: An ultrahard layer is deposited on the surface of the substrate with the optical functional layer by magnetron sputtering. In this invention, in step (4), when the superhard layer material used is carbon nitride, DC sputtering is used with graphite as the target material, and the process is carried out in a nitrogen and argon atmosphere. The argon flow rate is 50-600 sccm, the nitrogen flow rate is 60-600 sccm, and the target current is 8-30 A.

[0044] (5) Applying an anti-fingerprint layer: The anti-fingerprint solution is evaporated onto the surface of the superhard layer using a resistance heating evaporation method to form an anti-fingerprint layer, thereby obtaining the composite functional film.

[0045] The preferred parameters for the resistance heating evaporation method described in this invention are: a current of 5.0~15.0A, and a heating mode that can be constant current heating for 60~600s; or a stepped increase, for example, starting with a current of 5.0A and ending at 15.0A. To ensure the performance of the anti-fingerprint layer, the vacuum chamber needs to reach a certain vacuum level (3×10⁻⁶). -3 ~1×10 -4 Pa).

[0046] The present invention also provides the application of the composite functional film described above in the preparation of display device screens.

[0047] In this invention, the display device includes a mobile phone, computer, tablet, smartwatch, television, or vehicle display screen; The composite functional film is disposed on the outer surface or inner surface of the screen, or is disposed as an interlayer. Example 1 (1) Pretreatment: The aluminosilicate glass substrate was subjected to ultrasonic cleaning, alkaline cleaning, acid cleaning and pure water rinsing in sequence. First, it was ultrasonically cleaned for 20 minutes in a 5% neutral detergent solution at 50℃ to remove surface oil stains; then it was soaked in a 10% NaOH solution for 15 minutes to remove the surface oxide layer; then it was soaked in an 8% HNO3 solution for 10 minutes to neutralize the residual alkali and further clean; finally, it was ultrasonically cleaned with deionized water for 15 minutes, and then placed in a 120℃ oven to dry for 30 minutes to obtain the pretreated substrate.

[0048] (2) Deposition of bonding layer: A SiO2 bonding layer was deposited on the pretreated substrate surface using magnetron sputtering. The process parameters were set as follows: target power 12KW, voltage 500V, argon flow rate 500sccm, oxygen flow rate 800sccm, sputtering time 30 minutes, and vacuum degree maintained at 5×10 during the deposition process. -3 Pa, to obtain a substrate with a bonding layer.

[0049] (3) Deposition of optical functional layers: Titanium dioxide and silicon dioxide were alternately sputtered on the surface of a substrate with a bonding layer using magnetron sputtering to form 15 optical functional layers. For titanium dioxide sputtering, the process parameters were: target power 15KW, voltage 600V, argon flow rate 600sccm, oxygen flow rate 700sccm, and sputtering time for each layer controlled to 8 minutes according to thickness requirements. For silicon dioxide sputtering, the process parameters were: target power 10KW, voltage 400V, argon flow rate 400sccm, oxygen flow rate 600sccm, and sputtering time for each layer 6 minutes. The vacuum level was maintained at 3×10⁻⁶ throughout the process. -3 Pa, to obtain a substrate with an optical functional layer.

[0050] (4) Deposition of the superhard layer: A diamond-like carbon (DLC) superhard layer was deposited on the surface of a substrate with an optical functional layer using high-power pulsed magnetron sputtering (HiPIMS). High-purity graphite with a purity ≥ 99.99% was used as the target material, and sputtering was performed in a mixed atmosphere of argon and acetylene (C2H2). The process parameters were set as follows: argon flow rate 120 sccm, acetylene flow rate 80 sccm, duty cycle 6%, and peak power 800 W / cm. 2 Pulse frequency 500Hz, sputtering time 60 minutes, vacuum level controlled at 2×10 -3 Pa, to obtain a substrate with an ultra-hard layer.

[0051] (5) Applying an anti-fingerprint layer: A resistance heating evaporation method is used to evaporate a fluorinated anti-fingerprint solution onto the surface of the superhard layer to form an anti-fingerprint layer. The process parameters are: the vacuum chamber vacuum degree reaches 5×10⁻⁶. -4 Pa, the current is increased in a stepwise manner, starting from 5.0A and gradually increasing to 12.0A, with a total heating time of 300s, and finally a composite functional membrane is obtained.

[0052] Example 2 (1) Pretreatment: The colorless polyimide substrate is subjected to surface cleaning treatment. First, the surface of the substrate is wiped with a lint-free cloth dipped in isopropyl alcohol to remove surface dust; then, in a vacuum plasma cleaner, argon is used as the working gas, the power is 100W, and the treatment time is 5 minutes to further remove surface organic impurities and activate the surface, thereby improving the adhesion of subsequent film layers and obtaining the pretreated substrate.

[0053] (2) Bonding layer: A metallic Cr bonding layer was deposited on the pretreated substrate surface using magnetron sputtering. The process parameters were: target power 8KW, voltage 300V, argon flow rate 300sccm, sputtering time 15 minutes, and vacuum level maintained at 4×10⁻⁶. -3 Pa, to obtain a substrate with a bonding layer.

[0054] (3) Deposition of optical functional layers: Niobium oxide and magnesium fluoride were alternately sputtered on the surface of a substrate with a bonding layer using magnetron sputtering to form 25 optical functional layers. For sputtering niobium oxide, the process parameters were set as follows: target power 18KW, voltage 800V, argon flow rate 800sccm, oxygen flow rate 900sccm, and sputtering time per layer 10 minutes. For sputtering magnesium fluoride, the process parameters were set as follows: target power 12KW, voltage 500V, argon flow rate 500sccm, oxygen flow rate 700sccm, and sputtering time per layer 8 minutes. The vacuum level was controlled at 3×10⁻⁶ throughout the process. -3 Pa, to obtain a substrate with an optical functional layer.

[0055] (4) Deposition of the superhard layer: A TiCrCN superhard layer was deposited on the surface of a substrate with an optical functional layer using high-power pulsed magnetron sputtering (HiPIMS). Titanium-chromium alloy (Ti:Cr=1:1) was used as the target material, and sputtering was performed in a mixed atmosphere of argon, nitrogen, and acetylene. The process parameters were: argon flow rate 80 sccm, nitrogen flow rate 500 sccm (Ar:N2 flow ratio 1:6.25), acetylene flow rate 50 sccm, pulse frequency 300 Hz, duty cycle 8%, and peak power 1200 W / cm². 2 Sputtering time 45 minutes, vacuum degree 2×10 -3 Pa, to obtain a substrate with an ultra-hard layer.

[0056] (5) Applying an anti-fingerprint layer: The anti-fingerprint layer is applied using a resistance heating evaporation method. A fluorinated siloxane-based anti-fingerprint solution is placed in an evaporation boat, and the vacuum chamber reaches a vacuum level of 8 × 10⁻⁶. -4 Pa was used in a constant current heating mode with a current of 10A and a heating time of 240s to evaporate the medicine and form an anti-fingerprint layer on the surface of the superhard layer, thus obtaining a composite functional film.

[0057] Performance testing The composite functional membrane obtained in Example 1 was subjected to the following tests. 1. Hardness test Using a Glass-Bolithic pyramid indenter, the loading was controlled at the maximum depth of 150 nm, with a loading and unloading rate of 5 mN / min and a holding time of 10 s. Five points were tested for each sample (the maximum and minimum values ​​were discarded, and the average of the three points was calculated). A nanoindentation tester (such as Anton Paar NHT2, Agilent Nano Indenter G200, or Bruker Hysitron TI980) was used. The results obtained were: nanoindentation hardness ≥14 GPa. 2. Abrasion resistance test Rubber abrasion resistance: After 10,000 eraser cycles, the water droplet angle is ≥100°; Resistance to steel wool abrasion: After 2000 steel wool abrasion cycles, the water droplet angle is ≥100°.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A composite functional membrane, characterized in that, include: Substrate layer, bonding layer, optical functional layer, superhard layer, and anti-fingerprint layer; The substrate layer is one or more of soda-lime glass, aluminosilicate glass, microcrystalline glass, or flexible materials. The bonding layer is one of SiO2, Al2O3 or metallic Cr; The optical functional layer is an interference filter functional layer formed by alternating stacking of high refractive index materials and low refractive index materials; The superhard layer is one of diamond-like carbon, TiCrCN, (AlCrTiVZr)N, carbon nitride, or titanium nitride. The anti-fingerprint layer uses an anti-fingerprint solution.

2. The composite functional membrane according to claim 1, characterized in that, The flexible material is ultrathin glass, colorless polyimide, or polyethylene terephthalate; the thickness of the bonding layer is 1~100nm.

3. The composite functional membrane according to claim 1, characterized in that, The high refractive index material is one or more of titanium dioxide, zirconium oxide, silicon nitride, or niobium oxide; the low refractive index material is one or more of magnesium fluoride, silicon dioxide, or aluminum oxide.

4. The composite functional membrane according to claim 1, characterized in that, The optical functional layer has 8 to 30 layers.

5. A method for preparing the composite functional membrane according to any one of claims 1-4, characterized in that, Includes the following steps: (1) Pretreatment: The surface of the substrate is pretreated to obtain the pretreated substrate; (2) Depositing bonding layer: A bonding layer is deposited on the surface of the pretreated substrate by magnetron sputtering to obtain a substrate with a bonding layer; (3) Depositing an optical functional layer: Using magnetron sputtering, high refractive index material and low refractive index material are alternately sputtered on the surface of the substrate with the bonding layer to obtain a substrate with an optical functional layer; (4) Depositing an ultrahard layer: An ultrahard layer is deposited on the surface of the substrate with the optical functional layer by magnetron sputtering. (5) Applying an anti-fingerprint layer: The anti-fingerprint solution is evaporated onto the surface of the superhard layer using a resistance heating evaporation method to form an anti-fingerprint layer, thereby obtaining the composite functional film.

6. The preparation method according to claim 5, characterized in that, In step (2), when the bonding layer material is SiO2, the process parameters of the magnetron sputtering method are: target power 8-20KW, voltage 200-1000V, argon flow rate 100-1000sccm, and oxygen flow rate 100-1500sccm. When the bonding layer material used is Al2O3, the process parameters of the magnetron sputtering method are: target power 8-20KW, voltage 200-1000V, argon flow rate 100-1000sccm, and oxygen flow rate 100-1500sccm. When the bonding layer material used is metallic Cr, the process parameters of the magnetron sputtering method are: target power 8-20KW, voltage 200-1000V, and argon flow rate 100-1000sccm.

7. The preparation method according to claim 5, characterized in that, In step (3), when the optical functional layer material used is magnesium fluoride, silicon dioxide or aluminum oxide, the process parameters of the magnetron sputtering method are: target power 8-20KW, voltage 200-1000V, argon flow rate 100-1000sccm, oxygen flow rate 100-1500sccm. When the optical functional layer material used is silicon nitride, the process parameters of the magnetron sputtering method are: target power 8-20KW, voltage 200-1000V, argon flow rate 100-1000sccm, and nitrogen flow rate 100-1500sccm. When the optical functional layer material used is niobium oxide, the process parameters of the magnetron sputtering method are: target power 8-20KW, voltage 200-1000V, argon flow rate 100-1000sccm, and oxygen flow rate 100-1500sccm. When the optical functional layer material used is titanium dioxide, the process parameters of the magnetron sputtering method are: target power 8-20KW, voltage 200-1000V, argon flow rate 100-1000sccm, and oxygen flow rate 100-1500sccm. When the optical functional layer material used is zirconium oxide, the process parameters of the magnetron sputtering method are: target power 8-20KW, voltage 200-1000V, argon flow rate 100-1000sccm, and oxygen flow rate 100-1500sccm.

8. The preparation method according to claim 5, characterized in that, In step (4), when the superhard layer material used is carbon nitride, DC sputtering is used with graphite as the target material, and the process is carried out in a nitrogen and argon atmosphere. The argon flow rate is 50-600 sccm, the nitrogen flow rate is 60-600 sccm, and the target current is 8-30 A. When diamond-like carbon is used as the superhard layer material, a high-purity graphite target (purity ≥99.99%) is used as the target material, and high-power pulsed magnetron sputtering (HiPIMS) is employed in an atmosphere of argon and hydrogen-containing gas (C2H2). The argon flow rate is 50–200 sccm, the acetylene flow rate is 10–200 sccm, the duty cycle is 3–10%, and the peak power is 100–2000 W / cm. 2 ; When TiCrCN is used as the superhard layer material, titanium and chromium (or titanium-chromium alloy) are used as targets, and high-power pulsed magnetron sputtering (HiPIMS) is employed in an atmosphere of argon, nitrogen, and acetylene. The argon flow rate is 50–200 sccm, the nitrogen flow rate is 250–1000 sccm, the Ar:N2 flow ratio is 1:1–5:1, the acetylene flow rate is 10–200 sccm, the pulse frequency is 50–1000 Hz, the duty cycle is 3–10%, and the peak power is 100–2000 W / cm². 2 ; When the superhard layer material used is (AlCrTiVZr)N, an AlCrTiVZr alloy target is used as the target material, and high-power pulsed magnetron sputtering (HiPIMS) is employed under an argon and nitrogen atmosphere. The argon flow rate is 50–200 sccm, and the nitrogen flow rate is 250–1000 sccm; the Ar:N2 flow ratio is 1:1 to 5:1, the pulse frequency is 50–1000 Hz, the duty cycle is 3–10%, and the peak power is 100–2000 W / cm². 2 ; When titanium nitride is used as the superhard layer material, titanium metal is used as the target material, and medium-frequency magnetron sputtering is carried out in a nitrogen and argon atmosphere. The argon flow rate is 300-1200 sccm, the nitrogen flow rate is 300-1200 sccm, and the target power is 8-20 kW.

9. The use of the composite functional film according to any one of claims 1-4 in the preparation of a display device screen.

10. The application according to claim 9, characterized in that, The display devices include mobile phones, computers, tablets, smartwatches, televisions, or vehicle displays; The composite functional film is disposed on the outer surface, inner surface, or as a sandwich layer of the screen.