Antistatic anti-fingerprint nano-composite optical coating as well as preparation method and application thereof

Abstract

The invention relates to an antistatic fingerprint-proof nano-composite optical coating and a preparation method and application thereof.The nano-composite optical coating is arranged on a substrate and comprises a transition layer and a functional layer from bottom to top, and the transition layer is made of SiO2 nano-particles; the functional layer comprises a conductive layer and an AF layer, and the conductive layer is a compound of fluorine-doped zinc oxide (ZnO: F) and a carbon nanotube (CNT). The nano-composite optical coating disclosed by the invention has antistatic and anti-fingerprint properties, is suitable for high-end smart phones, folding screens and vehicle-mounted touch panels, and is low in preparation cost.

Description

Technical Field

[0001] The present invention relates to a nano-composite optical coating for electronic product display screens and a preparation method thereof, and in particular to an anti-static and anti-fingerprint nano-composite optical coating for electronic product display screens and a preparation method and application thereof. Background Art

[0002] Nowadays, most electronic product displays such as mobile phones, tablets, and car panels have touch functions. During touch use, the charge carried by the human body will be transferred to the cover glass of the electronic product. When the charge accumulates too much and cannot be conducted away and dispersed in time, it may penetrate the cover glass of the display and enter the interior of the mobile phone, tablet and other electronic components, causing problems such as touch failure, jamming, and freezing of the electronic product, which greatly affects the user experience, especially in some use cases that require high operational sensitivity. Therefore, how to conduct the charge transferred from the human body to the cover glass of the electronic product in a timely manner to avoid the electrostatic hazards caused by charge accumulation is one of the current hot topics in the research of electronic display touch screen technology. If a protective film with conductive properties and anti-static function can be developed and covered on the cover glass, it will be able to solve the above problems well.

[0003] However, common cover glass protective films are typically anti-fingerprint films, also known as AF (Anti-Fingerprint) films. These films, primarily made of fluorine and silicon, only offer anti-fingerprint, anti-fouling, and easy-to-clean properties, but lack conductive or anti-static properties. While conductive films like indium tin oxide (ITO) offer anti-static properties, they have low hardness, are easily oxidized, and exhibit poor adhesion to AF coatings. Multi-layer composite processes are complex, and high-temperature annealing can affect the performance of the glass substrate. Summary of the Invention

[0004] The first technical problem to be solved by the present invention is to provide an anti-static and anti-fingerprint nano-composite optical coating, which adopts the design of composite functional layers and can be both anti-static and anti-fingerprint, and has strong adhesion between coatings.

[0005] The second technical problem to be solved by the present invention is to provide a method for preparing an anti-static and anti-fingerprint nano-composite optical coating, which adopts a low-temperature film-forming process in combination with the functional layer material to prevent damage to the substrate performance.

[0006] The technical solution adopted by the present invention to solve the first technical problem is an anti-static and anti-fingerprint nano-composite optical coating, which is arranged on a substrate. The nano-composite optical coating includes a transition layer and a functional layer from bottom to top, and the transition layer is SiO2 nanoparticles; the functional layer includes a conductive layer and an AF layer, and the conductive layer is a composite of fluorine-doped zinc oxide (ZnO:F) and carbon nanotubes (CNTs).

[0007] Preferably, the mass ratio of the fluorine-doped zinc oxide to the carbon nanotubes is 7.2:2.8-8.5:1.5.

[0008] Preferably, the thickness of the transition layer is 10-20 nm, and the particle size of the SiO2 nanoparticles is 8-12 nm.

[0009] Preferably, the AF layer is a copolymer of perfluoropolyether and cage-type silsesquioxane (PFPE-POSS).

[0010] Preferably, the thickness of the conductive layer is 50-100 nm, and the surface resistivity is ≤ 1×10 9 Ω / sq.

[0011] Preferably, the thickness of the AF layer is 10-30 nm.

[0012] Preferably, the substrate is soda-lime glass or high alumina-silica glass.

[0013] Preferably, the thickness of the transition layer is 5-20 nm.

[0014] The technical solution adopted by the present invention to solve the second technical problem is a method for preparing the anti-static and anti-fingerprint nanocomposite optical coating, comprising the following steps:

[0015] S1, the substrate is plasma pretreated and coated with a SiO2 nanoparticle transition layer;

[0016] S2, depositing a ZnO:F / CNT conductive layer using magnetron sputtering;

[0017] S3. Coat the PFPE-POSS solution using a sol-gel method and cure at 70-80° C. for 25-30 min to form an AF layer.

[0018] In the present invention, there is no limitation on the method of coating the SiO2 nanoparticle transition layer, for example, plasma spraying can be used.

[0019] Furthermore, in step S2, the parameters of the magnetron sputtering method are: sputtering power 60W-80W, argon atmosphere, substrate temperature ≤100°C.

[0020] The antistatic and anti-fingerprint nanocomposite optical coating of the present invention is mainly used for surface treatment of flexible substrates.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows: in the antistatic and anti-fingerprint nanocomposite optical coating of the present invention, ZnO:F and CNT synergistically improve the conductivity and transmittance (≥92%@550nm), avoiding the problem of excessive haze of metal nanowires; super-hydrophobicity and wear resistance are achieved through PFPE-POSS copolymer (the contact angle remains >105° after 500 steel wool tests); the transition layer design solves the interfacial stress problem of the multilayer film, and the 100-grid test reaches 5B level.

[0022] The preparation method of the present invention uses a low-temperature film-forming process (less than 100°C) and is compatible with flexible glass substrates. It is suitable for high-end smartphones, foldable screens, and automotive touch panels, with low production costs and potential for large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of the structure of the nanocomposite optical coating of the present invention. DETAILED DESCRIPTION

[0024] The following description sets forth numerous specific details to facilitate a thorough understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art may make similar modifications without departing from the scope of the present invention. Therefore, the present invention is not limited to the specific implementations disclosed below.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. It should be noted that the reagents used in the present embodiment are all common commercially available products.

[0026] Example 1

[0027] A transition layer, a conductive layer and an AF layer are sequentially coated on a glass substrate (soda-lime glass).

[0028] Transition layer: SiO2 nanoparticle layer, thickness 15nm (particle size 10nm, plasma spraying).

[0029] Conductive layer: ZnO:F to CNT mass ratio 8:2, thickness 80nm.

[0030] Magnetron sputtering process parameters:

[0031] Base temperature: 80°C (measured value 80±2°C)

[0032] Working vacuum degree: ≤5.0*10 - 3PA

[0033] Working gas: AR (purity 99.999%) flow rate 50sccm

[0034] Sputtering power: 60-80W

[0035] Target distance: 80MM

[0036] Sputtering time: 12MIN

[0037] Substrate rotation speed: 10RPM

[0038] AF layer: PFPE-POSS copolymer, thickness 20 nm (sol-gel method, curing temperature 80°C).

[0039] Sol-gel process:

[0040] Coating method: slit extrusion coating

[0041] Coating speed: 0.5M / MIN

[0042] Leveling conditions: 25°C, humidity 40% RH, leveling time 60S

[0043] Curing procedure: step-by-step heating: 50°C*5min-80°C*25min.

[0044] Example 2

[0045] Substrate: UTG ultra-thin flexible glass (thickness 50μm).

[0046] Process temperature: ≤80℃ throughout the process (to avoid thermal deformation of flexible glass).

[0047] The rest is the same as in Example 1.

[0048] Comparative Example 1

[0049] On the basis of Example 1, a conductive layer and an AF layer are sequentially coated only on the base soda-lime glass.

[0050] Comparative Example 2

[0051] Referring to KR1020150078700A, fluorosilane was coated on a soda-lime glass substrate to form an AF layer.

[0052] Comparative Example 3

[0053] On the basis of Example 1, a conductive layer is formed only on the soda-lime glass substrate by magnetron sputtering.

[0054] Comparative Example 4

[0055] Referring to US Pat. No. 10,312,133, an ITO (indium tin oxide) conductive layer and an AF layer of perfluoroalkylsilane (PFAS) are sequentially formed on a soda-lime glass substrate.

[0056] Comparative Example 5

[0057] Referring to the process of JP2019518322A, an ITO conductive layer and an AF layer are formed on a base soda-lime glass. The process steps are as follows:

[0058] 1.ITO sputtering

[0059] Target material: ITO ceramic target (density ≥ 99%, SnO2 content 10wt%)

[0060] Temperature: 80-100℃

[0061] Gas: Ar / O2=95 / 5vol% Pressure 0.5MPA

[0062] Power: DC 1.5kw Sputtering rate 0.5nm / s

[0063] 2.AF layer coating

[0064] PFPE-POSS copolymer, thickness (20 nm)

[0065] Performance Testing

[0066] The performance tests were conducted on the films prepared in Examples 1-2 and Comparative Examples 1-5.

[0067] Surface resistivity (Ω / sp) was tested according to ASTM D257;

[0068] Static contact angle (°) was tested according to ASTM D7334;

[0069] Light transmittance (@550nm) is tested according to JIS K7361;

[0070] Abrasion resistance (haze change) Taber CS-10F tested, 500g / 500 times;

[0071] Adhesion is tested on a 100-grid basis in accordance with ISO2409-2020.

[0072] The results are shown in Table 1.

[0073] Table 1

[0074]

[0075]

[0076] The films prepared in Example 1, Comparative Example 1, and Comparative Example 4 were tested for interface strengthening and environmental stability. The interfacial peel strength was tested using a peel strength tester, and the environmental stability was verified by a 500-hour test at 85°C / 85% RH. The results are shown in Table 2.

[0077] Table 2

[0078] Performance indicators Example 1 Comparative Example 1 (without transition layer) Comparative Example 4 (double-layer coating) <![CDATA[Interface peeling force (N / mm 2 )]]> 28.5 18.2 9.8 High temperature and high humidity test No stratification Edge microcracks Large area shedding

[0079] As shown in Table 2, the interfacial peeling force of Example 1 of the present invention is improved by 191% compared to Comparative Example 4 and by 57% compared to Comparative Example 1 without a transition layer. The high temperature and high humidity test results show that the multilayer structure of Example 1 of the present invention has good durability.

[0080] The film layers prepared in Example 2 and Comparative Example 5 were subjected to a bending test according to the IEC62715-6-1 standard. The results are shown in Table 3.

[0081] Table 3 Bending test results

[0082] Performance indicators Example 2 Comparative Example 5 (High Temperature Process ITO+AF) Bending test (100,000 times) Resistivity change <5% Resistivity increase> 50% Substrate warpage (μm) ≤3 ≥15

[0083] As shown in Table 3, the nanocomposite optical coating provided by the present invention is compatible with flexible substrates, preventing warping and performance degradation caused by high temperatures. Furthermore, its resistance stability after bending is significantly superior to that of traditional ITO solutions, making it suitable for surface protection of foldable screens.

[0084] The conductive properties of different CNT doping ratios (0, 10 wt%, 20 wt%, 30 wt%) in the conductive layer are shown in Table 4.

[0085] Table 4 Effect of different CNT doping ratios on conductive properties

[0086]

[0087]

[0088] As shown in Table 4, when the CNT doping ratio is between 15% and 25%, the conductive performance is improved compared with pure ZnO:F. When the CNT doping ratio is 20%, the conductive performance is improved the most.

[0089] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An anti-static and anti-fingerprint nanocomposite optical coating, which is arranged on a substrate, characterized in that: The nanocomposite optical coating comprises a transition layer and a functional layer from bottom to top, wherein the transition layer is SiO2 nanoparticles; the functional layer comprises a conductive layer and an AF layer, wherein the conductive layer is a composite of fluorine-doped zinc oxide and carbon nanotubes.

2. The antistatic and anti-fingerprint nanocomposite optical coating according to claim 1, characterized in that: The mass ratio of the fluorine-doped zinc oxide to the carbon nanotubes is 7.2:2.8-8.5:1.5d.

3. The antistatic and anti-fingerprint nanocomposite optical coating according to claim 1, characterized in that: The AF layer is a copolymer of perfluoropolyether and cage-type silsesquioxane.

4. The anti-static and anti-fingerprint nanocomposite optical coating according to claim 1, characterized in that: The thickness of the conductive layer is 50-100 nm, and the surface resistivity is ≤1×10 9 Ω / sq.

5. The anti-static and anti-fingerprint nanocomposite optical coating according to claim 3, characterized in that: The thickness of the AF layer is 10-30 nm.

6. The antistatic and anti-fingerprint nanocomposite optical coating according to any one of claims 1 to 5, characterized in that: The substrate is soda-lime glass or high-alumina-silica glass.

7. The antistatic and anti-fingerprint nanocomposite optical coating according to claim 1 or 2, characterized in that: The thickness of the transition layer is 5-20 nm.

8. The method for preparing the antistatic and anti-fingerprint nanocomposite optical coating according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1, the substrate is plasma pretreated and coated with a SiO2 nanoparticle transition layer; S2, depositing a ZnO:F / CNT conductive layer using magnetron sputtering; S3. Coat the PFPE-POSS solution using a sol-gel method and cure at 70-80° C. for 25-30 min to form an AF layer.

9. The method for preparing the antistatic and anti-fingerprint nanocomposite optical coating according to claim 8, characterized in that: In step S2, the parameters of the magnetron sputtering method are: sputtering power 60W-80W, argon atmosphere, substrate temperature ≤100°C.

10. Use of the antistatic and anti-fingerprint nanocomposite optical coating according to any one of claims 1 to 7 in the surface treatment of a flexible substrate.

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