Waterproof wear-resistant nano coating and preparation method thereof

Abstract

The invention discloses a waterproof wear-resistant nano coating and a preparation method thereof, and belongs to the technical field of plasma chemical vapor deposition. Comprising the following steps that a plasma vacuum reaction bin is vacuumized, and after inert gas or nitrogen is introduced, a plasma power source is started for activation cleaning treatment; glow discharge is started to conduct bombardment pretreatment on the base material, and inert gas or nitrogen is introduced to control the vacuum degree; nanometer medicine steam of the soft coating is input through a mass flow controller, plasma chemical vapor deposition is carried out, and a soft coating nanometer film is prepared; and after the vacuum degree is adjusted, nanometer medicine steam of the hard coating is input, and the hard coating nanometer film is deposited. A special deposition method and a cross-linking polymerization reaction method are adopted, a multi-layer film structure of the soft coating and the hard coating is deposited on the surface of the base material, the hydrophobic property, the oleophobic property and the wear-resisting property of the base material are further improved, and therefore the corrosion resistance and the underwater electrifying resistance of an electronic product are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of plasma chemical vapor deposition, and in particular relates to a waterproof and wear-resistant nano coating and a preparation method thereof. Background Art

[0002] Polymer coatings are often used to protect the surface of materials due to their economical, easy coating, and wide range of applications. They can give materials good physical and chemical durability. In recent years, based on the barrier properties of polymer coatings, they have been widely used in preventing liquid penetration and corrosion. However, polymer coatings have poor crystallinity and are mostly amorphous, which cannot effectively prevent liquids from penetrating the coating. At present, the main methods for improving the anti-permeability of polymer coatings on electronic circuits include spray-on conformal coatings, parylene coatings, and polymer coatings.

[0003] Plasma chemical vapor deposition (PCVD) is a technology that uses plasma to activate reactive gases, promote chemical reactions on the substrate surface or near the surface space, and generate solid films. Plasma chemical vapor deposition coatings have the following advantages:

[0004] (1) It is a dry process, and the resulting film is uniform and pinhole-free.

[0005] (2) The chemical and physical properties of the plasma polymerized film, such as solvent resistance, chemical corrosion resistance, heat resistance, and wear resistance, are stable.

[0006] (3) The plasma polymerized film has good adhesion to the substrate.

[0007] (4) A uniform film can also be produced on a substrate surface with extremely irregular contours.

[0008] (5) Wide selectivity of substrates and monomers.

[0009] However, the performance of the thin films produced by plasma chemical vapor deposition is relatively simple. The thin films with high wear resistance cannot guarantee flexibility, and the thin films with high flexibility cannot guarantee both wear resistance and barrier properties. Based on this, the present invention proposes a waterproof and wear-resistant nano coating and a preparation method thereof. Summary of the invention

[0010] The purpose of the present invention is to provide a waterproof and wear-resistant nano coating and a preparation method thereof, which can further improve the corrosion resistance and underwater power supply resistance of electronic products on the basis of ensuring the hydrophobicity and hardness of the nano coating at the same time.

[0011] To achieve the above object, the present invention provides a method for preparing a waterproof and wear-resistant nano coating, comprising the following steps:

[0012] Place the substrate in a vacuum environment, introduce an inert gas or nitrogen, and then turn on the plasma radio frequency power supply for activation cleaning;

[0013] Introduce nano-drug vapor, and sequentially prepare a soft coating and a hard coating by plasma chemical vapor deposition;

[0014] Among them, the nano-drug vapor component of the soft coating is: at least one monofunctional unsaturated fluorocarbon resin;

[0015] The nano-drug vapor component of the hard coating is: a mixture of at least one monofunctional unsaturated fluorocarbon resin and at least one polyfunctional unsaturated hydrocarbon derivative, and the mass ratio of the polyfunctional unsaturated hydrocarbon derivative is 10% - 50%.

[0016] Furthermore, the vacuum degree of the activation cleaning is 10 mTorr - 200 mTorr, and the flow rate of the inert gas or nitrogen introduced is 20 sccm - 200 sccm.

[0017] Furthermore, the temperature of the vacuum environment is 40°C - 50°C.

[0018] Furthermore, the soft coating is prepared by the following method:

[0019] Bombard and pre-treat the substrate by glow discharge;

[0020] Introduce an inert gas and adjust the vacuum degree to 30 mTorr - 300 mTorr;

[0021] Turn on the plasma discharge for chemical vapor deposition.

[0022] Furthermore, the power of the glow discharge is 2 W - 500 W, the time is 180 s - 600 s, and the flow rate of the inert gas introduced is 20 sccm - 200 sccm.

[0023] Furthermore, the flow rate of the nano-drug vapor introduced into the soft coating is 10 sccm - 40 sccm, and the vacuum degree is maintained at 10 mTorr - 50 mTorr.

[0024] Furthermore, the flow rate of the nano-drug vapor introduced into the hard coating is 10 sccm - 30 sccm, and the vacuum degree is maintained at 10 mTorr - 50 mTorr.

[0025] Furthermore, the plasma discharge power for depositing the soft coating and the hard coating is 10 W - 300 W, and the continuous discharge time is 360 s - 2400 s.

[0026] Furthermore, the plasma discharge mode in the plasma chemical vapor deposition is radio frequency discharge or medium frequency discharge.

[0027] On the other hand, the present invention provides a waterproof and wear-resistant nano-coating, which is prepared by the above-mentioned preparation method of the waterproof and wear-resistant nano-coating.

[0028] In summary, the present invention has the following advantages:

[0029] The preparation method of the present application can deposit a softer soft coating (waterproof layer) and a harder hard coating (wear-resistant layer) on the base product, and improves the disadvantage of poor wear resistance of the nano-film by means of plasma-enhanced chemical vapor deposition, fully improving the performance of the waterproof and wear-resistant nano-coating. Among them, the waterproof layer has excellent flexibility and can effectively resist thermal shock; the wear-resistant layer has high hardness and better combined properties, but its flexibility is poor and it is prone to generate fine cracks when the product is deformed or under thermal and cold shock. Therefore, the method of using a double-layer (or multi-layer) coating can not only take into account the advantages of both, but also make up for their respective defects, thereby ensuring the hydrophobicity and hardness of the waterproof and wear-resistant nano-coating (nano-film), and improving the corrosion resistance and underwater power-on resistance of electronic products. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of a photo of the waterproof and wear-resistant nano-coating prepared in the embodiment of the present application under a 100,000-fold electron microscope.

[0031] Figure 2 It is a schematic diagram of the process for preparing the waterproof and wear-resistant nano-coating in the embodiment of the present application;

[0032] Figure 3 It is a schematic diagram of the comparison of the water intake of the Zeiss CZJ coated and uncoated samples;

[0033] Figure 4 It is a column chart of the contact angles of different liquids on the surface of ABS before and after being treated by the treatment method of the embodiment of the present application;

[0034] Figure 5 It is a schematic diagram of the contact angles of different liquids on the surface of ABS before and after being treated by the treatment method of the embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] The principles and features of the present application will be described below in conjunction with the embodiments. The examples given are only for explaining the present application and are not intended to limit the scope of the present application. Those not specified in the examples are carried out under conventional conditions or conditions recommended by the manufacturer. Those reagents or instruments not specified by the manufacturer can be obtained as conventional products through commercial purchase.

[0036] As Figure 2 shown, the present application provides a preparation method of a waterproof and wear-resistant nano-coating, which endows the base material with excellent water and wear resistance by depositing a special nano-film on the surface of the base material.

[0037] Specifically, the preparation method includes the following steps:

[0038] S1. Place the substrate in the reaction chamber (with a volume of 500 L) of the plasma, continuously evacuate the reaction chamber, evacuate the vacuum degree to 10 mTorr - 200 mTorr, introduce an inert gas or nitrogen, and keep the temperature of the reaction chamber always at 40 °C - 50 °C;

[0039] S2. Bombard and pre-treat the substrate through glow discharge. The power of the glow discharge is 2 W - 500 W, and at the same time, inject an inert gas into the chamber body with a flow rate of 20 sccm - 200 sccm, and the discharge time is 180 s - 600 s;

[0040] S3. Introduce the monomer vapor of the soft coating into the chamber. Pass the monomer vapor of the soft coating through a mass flow controller and introduce it into the reaction chamber body with a flow rate of 10 sccm - 40 sccm. Keep the vacuum degree at 30 mTorr - 300 mTorr, turn on the plasma discharge, and perform chemical vapor deposition to prepare the first layer of coating, that is, the soft coating.

[0041] S4. Stop introducing the monomer vapor of the soft coating. Wait until the vacuum degree drops below 10 mTorr, introduce the monomer vapor of the hard coating through a mass flow controller, introduce it into the reaction chamber body with a flow rate of 10 sccm - 40 sccm, keep the vacuum degree at 30 mTorr - 300 mTorr, turn on the plasma discharge again, and perform chemical vapor deposition to prepare the second layer of coating, that is, the hard coating.

[0042] S5. Stop the plasma radio frequency source, and at the same time stop introducing the monomer vapor. Continuously evacuate for 60 s - 120 s, discharge the gas in the vacuum chamber, and break the vacuum to restore the atmospheric pressure.

[0043] In the above solution, the present application first performs an activation cleaning treatment on the surface of the substrate, then a bombardment pretreatment, and finally prepares it by multiple chemical vapor depositions of different nano-films. Among them, by using a mass flow controller and a precise vacuum system, the present application can very precisely control the flow rate of the monomer and the pressure in the reaction chamber, thereby achieving precise control of the coating thickness and composition. Plasma-assisted chemical vapor deposition can form a uniform coating on the entire surface of the substrate, which is very important for electronic materials because uneven coatings may lead to inconsistent performance. Secondly, glow discharge pretreatment can clean the surface of the substrate, improve its activity, and thus enhance the adhesion between the coating and the substrate. By preparing the soft coating first and then the hard coating in sequence, a multi-layer nano-film with gradient properties can be obtained, and this structure can combine the elasticity of the soft coating and the wear resistance of the hard coating. At the same time, without limiting the number of coating layers and thickness, the application range can be increased. For example, the thickness of the nano-film in the present application is generally 100 nm to 400 nm. The soft coating has a low crosslinking degree and strong deformation ability. The hard coating has a large crosslinking degree, good compactness, and relatively high hardness. The combination of the soft coating and the hard coating can provide excellent physical properties such as wear resistance, scratch resistance, and good mechanical strength. At the same time, using plasma technology can carry out the reaction at a lower temperature, reducing energy consumption and possible harmful by-products. The method provided by the present application is applicable to a variety of substrates, including metals, semiconductors, plastics, etc., with high flexibility, and also has a high deposition rate, and can form a coating with the required thickness in a short time. The process parameters of the method provided by the present application are easy to repeat, suitable for large-scale production, and help to reduce costs.

[0044] In summary, adopting the preparation method of the present application for preparing nano-materials provides highly controllable process parameters, can prepare nano-films with excellent properties, is applicable to the surface modification of electronic materials, and helps to improve the reliability and durability of electronic products.

[0045] In some alternative embodiments of the present application, the nano-drug vapor component of the soft coating is: at least one monofunctional unsaturated fluorocarbon resin, that is, it can be one monofunctional unsaturated fluorocarbon resin or a mixture of multiple monofunctional unsaturated fluorocarbon resins.

[0046] The nano-drug vapor component of the hard coating is: a mixture of at least one monofunctional unsaturated fluorocarbon resin and at least one polyfunctional unsaturated hydrocarbon derivative, and the mass ratio of the polyfunctional unsaturated hydrocarbon derivative is 10% to 50%. That is, it can be a mixture of one monofunctional unsaturated fluorocarbon resin and one polyfunctional unsaturated hydrocarbon derivative, or a mixture of one monofunctional unsaturated fluorocarbon resin and multiple polyfunctional unsaturated hydrocarbon derivatives, or a mixture of multiple monofunctional unsaturated fluorocarbon resins and multiple polyfunctional unsaturated hydrocarbon derivatives.

[0047] In the above solution, the monofunctional unsaturated fluorocarbon resin includes but is not limited to 2-(perfluorohexyl)ethyl methacrylate, perfluorooctylethyl acrylate, ethyl perfluorooctyl acrylate, (perfluorocyclohexyl)methacrylate, 4-ethynyltrifluorotoluene, 2-perfluorooctylethyl acrylate, heptadecafluorodecyl methacrylate, 3,3,3-trifluoro-1-propyne, etc.

[0048] The polyfunctional unsaturated hydrocarbon derivatives include but are not limited to ethoxylated trimethylolpropane triacrylate (ETPTA), dipropylene glycol diacrylate (TPGDA), neopentyl glycol diacrylate, diethylene glycol divinyl ether, ethylene glycol diacrylate, polyethylene glycol diacrylate, divinylbenzene, 1,6-hexanediol diacrylate, etc.

[0049] In this application, additional crosslinking points are introduced to form a crosslinked structure by introducing other monomer components with a multi-functional crosslinked structure. The plasma breaks the highly energetic active groups in the monomer components to form active sites, and the introduced additional active sites crosslink and polymerize with each other in the plasma environment to form a dense network structure. Therefore, the hydrophobicity and hardness of the thin film are ensured, and the corrosion resistance and underwater power-on resistance of electronic products are improved.

[0050] In some alternative embodiments of this application, the vacuum degree of the activation cleaning treatment is 10 mTorr to 200 mTorr, and the flow rate of the inert gas or nitrogen introduced is 20 sccm to 200 sccm. The vacuum degree referred to here is 10 mTorr to 200 mTorr, that is, the vacuum degree can be any value between 10 mTorr, 20 mTorr, 50 mTorr, 100 mTorr, 110 mTorr, 120 mTorr, 150 mTorr, 160 mTorr, 180 mTorr, and 200 mTorr. The experimental effects of this application can be achieved within this range. If the vacuum degree is lower than 10 mTorr, it will cause too much residual air or impurities (such as water vapor, oxygen), which may trigger non-target reactions (such as oxidation) and contaminate the surface of the substrate. It will also result in insufficient dilution effect of the inert gas, energy dispersion during plasma bombardment (step S2), and a decrease in the pretreatment efficiency. If the vacuum degree is higher than 200 mTorr, it will cause too low gas molecule density, making it difficult to stably excite the plasma during subsequent glow discharge (step S2), and the pretreatment will be uneven. It will also cause the gas or contaminants adsorbed on the surface of the substrate to not be fully discharged, affecting the adhesion of the subsequent coating.

[0051] Similarly, the flow rate of the inert gas or nitrogen gas introduced is 20 sccm to 200 sccm, that is, the flow rate can be any value among 20 sccm, 30 sccm, 40 sccm, 50 sccm, 60 sccm, 70 sccm, 80 sccm, 90 sccm, 100 sccm, and 200 sccm. The inert gas in this application specifically refers to argon or helium, or a mixed gas of argon and helium mixed in any ratio.

[0052] In some alternative embodiments of the present application, the temperature of the vacuum environment is 40°C to 50°C. The entire production process is carried out at a relatively low temperature (40°C to 50°C), which helps to avoid potential damage to the substrate (especially electronic materials) caused by high temperatures. For example, a low vacuum environment temperature (below 40°C) will cause trace pollutants (such as grease and water films) adsorbed on the surface of the substrate to be difficult to volatilize, resulting in incomplete pretreatment. It will also cause the monomer vapor of the subsequent coating (step S3 / step S4) to possibly condense on the low-temperature surface, forming droplet contamination. A high vacuum environment temperature (above 50°C) will cause the substrate to thermally expand and deform, especially the structural stability of the multi-layer printed board will be damaged. A high vacuum environment temperature will also cause the vacuum sealing material (such as a rubber ring) to age rapidly, leading to a risk of air leakage.

[0053] In some alternative embodiments of the present application, the soft coating is prepared by the following method:

[0054] The substrate is bombarded and pretreated by glow discharge;

[0055] An inert gas is introduced, and the vacuum degree is adjusted to 30 mTorr to 300 mTorr;

[0056] Plasma discharge is started for chemical vapor deposition.

[0057] In some alternative embodiments of the present application, the specific parameters of the glow discharge treatment before the production of the soft coating include: the power of the glow discharge is 2W to 500W, the time is 180s to 600s, and the flow rate of the inert gas introduced is 20sccm to 200sccm. The bombardment pretreatment can remove impurities on the surface of the substrate, and at the same time activate the surface of the substrate, which is more conducive to the deposition of the coating and improves the bonding strength between the coating and the substrate. The parameters of the glow discharge will all affect the results of the present application. For example, if the power of the glow discharge is too high (>500W), the high-energy ions will bombard excessively, resulting in too deep etching of the substrate surface, damaging the copper foil circuit or solder mask layer, and affecting the electrical performance. And local high temperature may cause carbonization (epoxy resin) or oxidation (copper layer) of the substrate, reducing the reliability. If the power is too low (<2W), the plasma density is insufficient, and pollutants cannot be effectively removed or the surface cannot be activated, resulting in poor adhesion of the soft / hard coating. If the glow discharge time is too long (>600s), the long-term bombardment may cause excessive etching of the surface layer material (such as copper, resin) of the substrate, resulting in out-of-control micro-roughness. If the time is too short (<180s), the pollutants or oxide layer on the substrate surface are not completely removed, and the interfacial bonding strength between the coating and the substrate is insufficient, resulting in easy peeling of the coating. And too short glow discharge time will also lead to insufficient activation, and it is difficult for the subsequent monomer vapor (step S3 / step S4) to effectively bond chemically, reducing the uniformity of the nano-film. The flow rate of the inert gas also affects the deposition effect of the present application. For example, too high a flow rate (>200sccm) will cause increased gas turbulence, uneven plasma distribution, and regional differences in the pretreatment effect. It will also cause an increase in the load of the vacuum pump and make it difficult to maintain the set vacuum degree (dynamic balance is required, and the cost increases). If the flow rate is too low (<20sccm), the gas supply will be insufficient, and the plasma energy cannot be effectively transferred to the substrate surface, resulting in ineffective cleaning or activation. Too low a flow rate (<20sccm) may also cause unstable discharge (such as arc discharge) due to local gas depletion.

[0058] In some alternative embodiments of the present application, the flow rate of the nano-drug vapor introduced into the soft coating is 10sccm to 40sccm, and the vacuum degree is maintained at 10mTorr to 50mTorr.

[0059] In some alternative embodiments of the present application, the flow rate of the nano-drug vapor introduced into the hard coating is 10sccm to 30sccm, and the vacuum degree is maintained at 10mTorr to 50mTorr.

[0060] In some alternative embodiments of the present application, the plasma discharge power for depositing the soft coating and the hard coating is 10W to 300W, and the continuous discharge time is 360s to 2400s.

[0061] This application requires controlling the steam flow rate. If the flow rate is too high, monomer molecules will accumulate in the chamber, making it difficult to fully react, resulting in unpolymerized liquid residues or loose film layers. Excessive flow rate will also cause more severe fluctuations in the vacuum degree, and the pumping speed needs to be frequently adjusted to maintain the set pressure (30 mTorr to 300 mTorr), leading to a decline in process stability. While if the flow rate is too low (<10 sccm), the deposition rate will be too low and the film growth time will be too long, which may result in non-compliance with the thickness standard (especially for hard coatings, a certain thickness is required for wear resistance). And in high aspect ratio structures (such as vias), monomer diffusion is insufficient, prone to missing plating or uneven coverage. This application also requires controlling the vacuum degree (30 mTorr to 300 mTorr). If the vacuum degree is too high (>300 mTorr, the actual air pressure is lower), the mean free path of gas molecules is too long, and the monomer vapor distribution is uneven, resulting in film thickness differences (thicker at the edges and thinner in the center). A high vacuum degree will also cause a decrease in plasma density, insufficient reaction activity, and a reduction in film densification (such as insufficient hardness of hard coatings). If the vacuum degree is too low (<30 mTorr, the actual air pressure is higher), gas molecules collide frequently, the lifetime of active free radicals is shortened, and the reaction efficiency decreases. At the same time, residual impurities (such as unexhausted pretreatment gases) may participate in side reactions and contaminate the film layer.

[0062] In summary, during plasma-enhanced chemical vapor deposition, by adjusting the flow rate and vacuum degree of the soft coating and hard coating nano-drug vapor, different coating characteristics can be achieved. A lower flow rate may result in a softer soft coating with better elasticity and the ability to adapt to deformation. This is very useful for the surface of electronic materials that require a certain degree of flexibility, such as in flexible electronic devices. A higher flow rate may make the hard coating more dense and hard, providing better mechanical strength and wear resistance. By first depositing a softer coating and then depositing a harder coating, a multi-layer structure with gradient properties can be formed. This structure can combine the elasticity of the soft coating and the protective effect of the hard coating to provide more comprehensive surface protection. Using different flow rates provided by this application can control the deposition rate, which on the one hand helps for more uniform deposition, and on the other hand can accelerate the deposition process and improve production efficiency. The flow rate of the soft coating may help reduce defects in the coating, such as holes and cracks, while the flow rate of the hard coating helps to quickly form a protective layer and reduce damage to the soft coating during subsequent processing. At the same time, the flow rate and vacuum degree in this application can be adjusted within a range to adapt to process changes and product requirements.

[0063] In some alternative embodiments of the present application, the plasma discharge mode in plasma enhanced chemical vapor deposition is radio frequency (RF) discharge or medium frequency (MF) discharge. During the plasma RF discharge process, the energy output mode of the plasma RF is controlled to be continuous output. Since the plasma has a certain etching effect on the deposited film during the continuous plasma RF discharge deposition process, a pulse generator is added during the RF output. In this way, the relative continuous discharge gives a certain deposition time, which is beneficial to the densification of the coating.

[0064] The above technical solutions of the present application will be described in detail below in conjunction with specific embodiments.

[0065] Example 1

[0066] This example provides a method for preparing a waterproof and wear-resistant nano-coating, which includes the following steps:

[0067] (1) Place the substrate in a vacuum plasma chamber, keep the chamber temperature at 45 °C, close the chamber door and continuously evacuate the chamber. Evacuate the vacuum degree in the vacuum chamber to 15 mTorr, introduce argon at a flow rate of 120 sccm, wait for 30 s, keep the vacuum degree at 40 mTorr, turn on the RF power supply, and perform pre-treatment on the substrate before coating. The plasma RF power is 300 W, and the treatment time is 180 s.

[0068] (2) Perform bombardment pre-treatment on the substrate through glow discharge. The power of the glow discharge is 300 W, the time of the glow discharge is 300 s, and at the same time, inject argon into the chamber with a flow rate of 200 sccm.

[0069] (3) Evacuate the vacuum degree in the chamber to 15 mTorr, introduce the monomer vapor of perfluorooctylethyl acrylate, and keep the vacuum degree at 30 mTorr. After waiting for 30 s, turn on the RF power supply to perform plasma enhanced chemical vapor deposition to prepare a soft coating.

[0070] Among them, the monomer vapor is introduced into the evaporation tank from low pressure through a drip valve, and then transported into the vacuum chamber by a vapor flow control valve with a flow rate of 20 sccm. The plasma RF power is 85 W, and the treatment time is 1500 s.

[0071] (4) Stop introducing the monomer vapor of perfluorooctylethyl acrylate, evacuate the vacuum degree in the chamber to 15 mTorr again to discharge the residual tail gas, introduce the monomer vapor of the hard coating, and keep the vacuum degree at 30 mTorr. After waiting for 30 s, turn on the RF power supply to perform plasma enhanced chemical vapor deposition to prepare a hard coating.

[0072] Among them, the hard coating monomer drug vapor is a mixture of ethyl perfluorooctyl acrylate and dipropylene glycol diacrylate, and the mass percentage of dipropylene glycol diacrylate in the mixture is 30%. The hard coating monomer drug vapor is introduced into the evaporation tank at low pressure through a dropping valve, and then transported into the vacuum chamber by a vapor flow control valve, with a flow rate of 15 sccm. The plasma radio frequency power is 105 W, and the treatment time is 1200 s.

[0073] (5) Stop the plasma radio frequency source and also stop introducing the vapor. Continuously evacuate for 120 s to exhaust the gas in the vacuum chamber, and then restore the atmospheric pressure.

[0074] Example 2

[0075] This example provides a method for preparing a waterproof and wear-resistant nano-coating, including the following steps:

[0076] (1) Place the substrate in the vacuum plasma chamber, keep the chamber temperature at 45 °C, close the chamber door and continuously evacuate the chamber. Pump the vacuum degree in the vacuum chamber to 15 mTorr, introduce argon at 120 sccm, wait for 30 s, keep the vacuum degree at 40 mTorr, turn on the radio frequency power supply, and perform pre-treatment on the substrate before coating. The plasma radio frequency power is 300 W, and the treatment time is 180 s.

[0077] (2) Perform bombardment pre-treatment on the substrate through glow discharge. The power of glow discharge is 500 W, the time of glow discharge is 180 s, and at the same time, inject argon into the chamber, with a flow rate of 120 sccm.

[0078] (3) Pump the vacuum degree in the chamber to 15 mTorr, introduce the monomer drug vapor of (perfluorocyclohexyl) methyl acrylate, and keep the vacuum degree at 50 mTorr. After waiting for 30 s, turn on the radio frequency power supply to perform plasma chemical vapor deposition to prepare the soft coating.

[0079] Among them, the monomer drug vapor is introduced into the evaporation tank at low pressure through a dropping valve, and then transported into the vacuum chamber by a vapor flow control valve, with a flow rate of 25 sccm. The plasma radio frequency power is 50 W, and the treatment time is 1200 s.

[0080] (4) Stop introducing the monomer drug vapor of (perfluorocyclohexyl) methyl acrylate, pump the vacuum degree in the chamber to 15 mTorr again, introduce the hard coating monomer drug vapor, and keep the vacuum degree at 50 mTorr. After waiting for 30 s, turn on the radio frequency power supply to perform plasma chemical vapor deposition to prepare the hard coating.

[0081] Among them, the hard coating monomer medicine vapor is a mixture of perfluorooctylethyl acrylate, diethylene glycol divinyl ether, and ethylene glycol diacrylate. The mass percentages of diethylene glycol divinyl ether and ethylene glycol diacrylate in the mixture are each 25%. The hard coating monomer medicine vapor is introduced into the evaporation tank at low pressure through a dropping valve and then transported into the vacuum chamber body by a vapor flow control valve, with a flow rate of 15 sccm. The plasma radio frequency power is 135 W, and the treatment time is 1200 s.

[0082] (5) Stop the plasma radio frequency source and also stop introducing the vapor. Continuously evacuate for 120 s to exhaust the gas in the vacuum chamber, and then restore the atmospheric pressure.

[0083] Example 3

[0084] This example provides a method for preparing a waterproof and wear-resistant nano-coating, including the following steps:

[0085] (1) Place the substrate in the vacuum plasma chamber body, keep the chamber body temperature at 45 °C, close the chamber door and continuously evacuate the chamber body to a vacuum degree of 15 mTorr. Introduce argon at 120 sccm, wait for 30 s, keep the vacuum degree at 40 mTorr, turn on the radio frequency power supply, and perform pre-treatment on the substrate before coating. The plasma radio frequency power is 300 W, and the treatment time is 180 s.

[0086] (2) Perform bombardment pre-treatment on the substrate through glow discharge. The power of the glow discharge is 300 W, the time of the glow discharge is 180 s, and at the same time, inject argon into the chamber, with a flow rate of 200 sccm.

[0087] (3) Pump the vacuum degree in the chamber body to 15 mTorr, introduce 4-ethynyltrifluorotoluene monomer medicine vapor, and keep the vacuum degree at 30 mTorr. After waiting for 30 s, turn on the radio frequency power supply to perform plasma chemical vapor deposition to prepare the soft coating.

[0088] Among them, the monomer medicine vapor is introduced into the evaporation tank at low pressure through a dropping valve and then transported into the vacuum chamber body by a vapor flow control valve, with a flow rate of 10 sccm. The plasma radio frequency power is 35 W, and the treatment time is 1200 s.

[0089] (4) Stop introducing the 4-ethynyltrifluorotoluene monomer medicine vapor, pump the vacuum degree in the chamber body to 15 mTorr again, introduce the hard coating monomer medicine vapor, and keep the vacuum degree at 15 mTorr. After waiting for 30 s, turn on the radio frequency power supply to perform plasma chemical vapor deposition to prepare the hard coating.

[0090] Among them, the hard coating monomer vapor is a mixture of perfluorooctylethyl acrylate, polyethylene glycol diacrylate, and 6-hexanediol diacrylate. The mass percentages of polyethylene glycol diacrylate and 6-hexanediol diacrylate in the mixture are 15% respectively. The hard coating monomer vapor is introduced into the evaporation tank at low pressure through a dropping valve and then transported into the vacuum chamber by a vapor flow control valve, with a flow rate of 15 sccm. The plasma radio frequency power is 35 W, and the treatment time is 900 s.

[0091] (5) Stop the plasma radio frequency source and also stop introducing the vapor. Continuously evacuate for 120 s to exhaust the gas in the vacuum chamber, and then restore the atmospheric pressure.

[0092] Example 4

[0093] This example provides a method for preparing a waterproof and wear-resistant nano-coating, which includes the following steps:

[0094] (1) Place the substrate in the vacuum plasma chamber, keep the chamber temperature at 45 °C, close the chamber door and continuously evacuate the chamber to a vacuum of 50 mTorr. Introduce nitrogen at 200 sccm, wait for 30 s, keep the vacuum at 40 mTorr, turn on the radio frequency power supply, and perform pre-treatment on the substrate before coating. The plasma radio frequency power is 300 W, and the treatment time is 180 s.

[0095] (2) Perform bombardment pre-treatment on the substrate through glow discharge. The power of the glow discharge is 500 W, the time of the glow discharge is 180 s, and at the same time, inject nitrogen into the chamber with a flow rate of 200 sccm.

[0096] (3) Pump the vacuum in the chamber to 15 mTorr, introduce the monomer vapor of the mixture of 4-ethynyltrifluorotoluene and 2-perfluorooctyl ethyl acrylate (mass ratio 1:1), and keep the vacuum at 35 mTorr. After waiting for 30 s, turn on the radio frequency power supply to perform plasma chemical vapor deposition to prepare the soft coating.

[0097] Among them, the monomer vapor is introduced into the evaporation tank at low pressure through a dropping valve and then transported into the vacuum chamber by a vapor flow control valve, with a flow rate of 20 sccm. The plasma radio frequency power is 70 W, and the treatment time is 360 s.

[0098] (4) Stop introducing the perfluorooctylethyl acrylate monomer vapor, pump the vacuum in the chamber to 15 mTorr again, introduce the hard coating monomer vapor, and keep the vacuum at 15 mTorr. After waiting for 30 s, turn on the radio frequency power supply to perform plasma chemical vapor deposition to prepare the hard coating.

[0099] Among them, the hard coating monomer drug vapor is a mixture of 3,3,3-trifluoro-1-propyne, divinylbenzene and polyethylene glycol diacrylate, and the mass percentages of divinylbenzene and polyethylene glycol diacrylate in the mixture are 20% respectively. The hard coating monomer drug vapor is introduced into the evaporation tank at low pressure through a dropping valve, and then transported into the vacuum chamber by a vapor flow control valve, with a flow rate of 20 sccm. The plasma radio frequency power is 150 W, and the treatment time is 360 s.

[0100] (5) Repeat steps (2) - (3) three times to form a multi-layered nanostructure film on the substrate surface.

[0101] (6) Stop the plasma radio frequency source and also stop introducing the vapor. Continuously evacuate for 120 s, discharge the gas in the vacuum chamber, and restore the atmospheric pressure.

[0102] Experimental Example 1:

[0103] The waterproof and wear-resistant nano-coatings (i.e., nano-films) prepared from Examples 1 - 4 have excellent hydrophobic and oleophobic properties, as well as excellent low surface tension and wear-resistant properties. Tested by the standard operation method of a reciprocating abrasion tester, the film thickness, water droplet contact angle, and oil droplet contact angle before and after the test are shown in Table 1. At the same time, the film thickness was observed through a 100,000-fold electron microscope, and the results are as Figure 1 shown.

[0104] Table 1

[0105]

[0106] As can be seen from Table 1, the waterproof and wear-resistant nano-coatings (i.e., nano-films) prepared by this application can maintain the water droplet contact angle between 100° and 130° before and after the experiment, indicating that the substrate surface is given a coating with excellent hydrophobic properties, thus having anti-fouling, anti-corrosion, self-cleaning, and anti-biofouling effects, further improving durability, reducing the penetration of moisture into the material surface, and preventing problems such as swelling and softening caused by water absorption. And water droplets on the hydrophobic surface are easy to roll off, reducing the scattering and refraction of water droplets on light, and can maintain the clarity of the material surface. Therefore, the preparation method provided by this application is also suitable for a variety of product applications, playing an important role in waterproofing of building materials to moisture-proofing of electronic products. At the same time, the nano-film obtained by the preparation method of this application also has certain oleophobic properties. Since oil stains are not easily attached, the wear and aging speed of the material surface slows down, thus improving the durability and service life of the product.

[0107] From Figure 1As can be seen from Table 1, the thickness of the waterproof and wear-resistant nano-coating (i.e., nano-film) prepared in this application is generally 100 nm to 400 nm, which can change the surface characteristics of electronic products, such as improving hydrophobicity, reducing fingerprint retention, making the product more stain-resistant and easy to clean. The nano-film can increase the wear resistance of the product, protect the underlying material from scratches and abrasion, and extend the service life of the product. It can isolate the material from direct contact with the external environment, thereby improving the corrosion resistance of the product, especially in a humid or chemically corrosive environment.

[0108] Experimental Example 2 (Relationship between gap size and water inflow volume)

[0109] Test purpose: To find the relationship between the gap size and the water inflow volume of the coated and uncoated samples.

[0110] Test design: Make boxes with gap sizes around the perimeter ranging from 0.05 to 0.4 mm. There are 2 boxes for each gap size, 1 CZJ-coated box and 1 uncoated box.

[0111] Test method: IPX2 test. Conduct the IPX2 test on the boxes and weigh the water inflow volume before and after the test.

[0112] Test results: As Figure 3 shown, the water inflow volume of the coated samples in this application is reduced by 80% - 90% compared with the uncoated samples. Among the test samples, for gaps of 0.05 mm - 0.4 mm, the water inflow volume of the CZJ-coated samples remains below 1.15 g; the water inflow volume of the uncoated samples increases linearly until it reaches as high as 8.62 g.

[0113] Experimental Example 3: Contact angle test

[0114] The contact angles of different liquids on the ABS with the nano-coating (coated) and without the nano-coating (uncoated) prepared in this application were tested, and the results are shown in Table 2 and Figure 4 - Figure 5 as shown.

[0115] Table 2

[0116] Liquid type Uncoated Coated Improvement rate Coke 79.3 118.6 49.6％ Pulpy Orange 73.6 114.9 56.1％ Lipton Black Tea 79.5 117.1 47.3％ Red ink 79.5 116.6 46.7％ Edible oil 34.2 96.9 183.3％ Beer 73.3 101.6 38.6％ Milk 67.3 98.6 46.5％ Strong coffee 74.5 100.6 35.0％ Weak coffee 64.6 112 73.4％

[0117] Figure 3 and Figure 4 the left bar chart in shows the uncoated situation, and the right shows the coated situation.

[0118] Although the specific implementation manners of this application have been described in detail, it should not be construed as a limitation on the protection scope of this patent. Within the scope described in the claims, various modifications and deformations that can be made by those skilled in the art without creative labor still fall within the protection scope of this patent.

Claims

1. A method for preparing a waterproof and wear-resistant nano coating, characterized in that: The following steps are involved: The substrate is placed in a vacuum environment, an inert gas or nitrogen is introduced, and then a plasma radio frequency power source is turned on for activation and cleaning treatment; The nano drug vapor is introduced, and the soft coating and the hard coating are sequentially prepared by plasma chemical vapor deposition; The nano drug vapor composition of the soft coating is: at least one monofunctional unsaturated fluorocarbon resin; The nano drug vapor composition of the hard coating is a mixture of at least one monofunctional unsaturated fluorocarbon resin and at least one multifunctional unsaturated hydrocarbon derivative, and the mass proportion of the multifunctional unsaturated hydrocarbon derivative is 10% to 50%.

2. The method for preparing the waterproof and wear-resistant nano coating according to claim 1, characterized in that: The vacuum degree of the activation cleaning process is 10 mTorr to 200 mTorr, and the flow rate of the inert gas or nitrogen is 20 sccm to 200 sccm.

3. The method for preparing the waterproof and wear-resistant nano coating according to claim 1, characterized in that: The vacuum environment temperature is 40°C to 50°C.

4. The method for preparing the waterproof and wear-resistant nano coating according to claim 1, characterized in that: The soft coating is prepared by the following method: The substrate is pretreated by bombardment through glow discharge; Introduce inert gas and adjust the vacuum degree to 30mTorr~300mTorr; The plasma discharge is turned on for chemical vapor deposition.

5. The method for preparing the waterproof and wear-resistant nano coating according to claim 4, characterized in that: The power of the glow discharge is 2W-500W, the time is 180s-600s, and the flow rate of the inert gas is 20sccm-200sccm.

6. The method for preparing the waterproof and wear-resistant nano coating according to claim 1, characterized in that: The flow rate of nano drug vapor introduced into the soft coating is 10 sccm to 40 sccm, and the vacuum degree is maintained at 10 mTorr to 50 mTorr.

7. The method for preparing the waterproof and wear-resistant nano coating according to claim 1, characterized in that: The flow rate of nano drug vapor introduced into the hard coating is 10 sccm to 30 sccm, and the vacuum degree is maintained at 10 mTorr to 50 mTorr.

8. The method for preparing the waterproof and wear-resistant nano coating according to claim 1, characterized in that: The plasma discharge power for depositing the soft coating and the hard coating is 10W to 300W, and the continuous discharge time is 360s to 2400s.

9. The method for preparing the waterproof and wear-resistant nano coating according to claim 1, characterized in that: The plasma discharge mode in the plasma chemical vapor deposition is radio frequency discharge or medium frequency discharge.

10. A waterproof and wear-resistant nano coating, characterized in that: The waterproof and wear-resistant nano coating is prepared by the preparation method of any one of claims 1 to 9.

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